JP6750219B2 - Modified polyamide resin and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a modified polyamide resin, a method for producing the same, and a molded article obtained by molding the same.

Polyamide resins have excellent mechanical properties, heat resistance, and chemical resistance, and thus are preferably used for automobiles and electric/electronic component applications. Among various applications, polyamide resins are used in parts such as engine covers that are exposed to extremely high temperatures because of their excellent heat aging resistance. 2. Description of the Related Art In recent years, the environmental temperature in the engine room has been increasing with the increasing density of components in the engine room of automobiles and the increase in engine output. Therefore, heat aging resistance under higher temperature conditions is required. Conventionally, as a technique for improving heat resistance and aging resistance of a polyamide resin, for example, a polyamide resin composition in which a copper compound and a halogen compound are mixed with a polyamide resin (for example, see Patent Document 1) is known. However, the polyamide resin composition of Patent Document 1 cannot obtain sufficient heat aging resistance due to the recent increase in use environment temperature. In response to this, various technical improvements have been attempted as techniques for further improving the heat aging resistance at high temperatures. For example, a polyamide resin composition containing a polyamide resin, a polyhydric alcohol having a number average molecular weight of less than 2000, a co-stabilizer such as a copper stabilizer or a hindered phenol, and a polymer reinforcing material (see, for example, Patent Document 2). ), a thermoplastic resin composition containing a polyamide resin and a polyhydric alcohol having a particle size of 70 microns or less (see Patent Document 3). Further, a polyamide resin composition containing a polyamide resin, a polyhydric alcohol, and an impact resistance improver (for example, see Patent Document 4) has been proposed.

JP, 2006-273945, A Special table 2011-599991 gazette Japanese Patent Publication No. 2014-525506 Japanese Patent Publication No. 2013-538927

However, although the molded articles obtained from the polyamide resin compositions of Patent Documents 2 to 4 have excellent heat aging resistance in the temperature range of 160°C to 240°C, they have high heat aging resistance in the temperature range of less than 160°C. There was a problem of being inferior. The environmental temperature of automobile engine compartment parts is increasing year by year, but it is not always high. Therefore, a material having heat aging resistance at low temperature is required for parts in the engine room of an automobile. In addition, the polyamide resin compositions of Patent Documents 2 to 4 have (i) bleed-out of a polyhydric alcohol or the like to the surface layer of a molded article, a problem in surface appearance such as coloring due to release of copper ions, and (ii) retention. There was a problem of poor stability. Furthermore, automobile parts such as engine room parts that require heat aging resistance are desired to have high dimensional accuracy, chemical resistance, and creep resistance at the same time as high heat aging resistance. The molded products obtained from the prepared polyamide resin composition did not have sufficient properties.

In view of these problems of the prior art, the present invention provides a modified polyamide resin which is excellent in retention stability, heat aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance. This is an issue.

In order to solve the above problems, the present invention mainly has the following configurations.
[1] 1 to 9 parts by weight of (A) the polyamide resin and (B) 1 to 9 parts by weight of an aliphatic compound which does not contain an epoxy group and has 4 or more and 6 or less hydroxyl groups and (C) two epoxies. A method for producing a modified polyamide resin comprising reacting a compound having a group and a molecular weight of 1650 to 5500 in an amount of 0.2 to 4.5 parts by weight, wherein (A) a polyamide resin and (B) an epoxy group are not included, and 4 The (B) epoxy group which can be obtained by 1H-NMR measurement of the above-mentioned aliphatic compound having 6 or less hydroxyl groups and (C) a dry blend of a compound having two epoxy groups and having a molecular weight of 1650 to 5500 A peak area (hereinafter, referred to as a peak area A) of a proton of a hydrocarbon bonded to the hydroxyl groups of an aliphatic compound that does not contain and has 4 to 6 hydroxyl groups, and (B) does not contain an epoxy group, and 4 4 or more and 6 or less hydroxyl groups which do not contain (B) epoxy groups which are peak-shifted by the reaction of the hydroxyl group of the aliphatic compound having one or more and 6 or less hydroxyl groups with the carboxyl terminal group of the (A) polyamide resin. From the peak area of the hydrocarbon bonded to the hydroxyl group of the aliphatic compound having a (hereinafter referred to as peak area b), the reaction rate (%) represented by the formula {b/(A+b)}×100 is 0. 1 to 30% of (A) polyamide resin, (B) epoxy group-free aliphatic compound having 4 or more and 6 or less hydroxyl groups, and (C) molecular weight having 2 epoxy groups. A method for producing a modified polyamide resin obtained by reacting 1650 to 5500 compounds .
[2] A method for producing a modified polyamide resin by melt-kneading using a twin-screw extruder having a plurality of kneading zones and a plurality of full flight zones, wherein the maximum of the resin pressures in the kneading zones is Of the resin pressure Pkmax (MPa), and the minimum resin pressure Pfmin (MPa) among the resin pressures in the full-flight zone at a plurality of positions are Pfmin+1.7≧Pkmax≧Pfmin+0.3. A method for producing a modified polyamide resin.

(In the general formula (1) and the general formula (2), R ^{1 to} R ³ each independently represent an aliphatic, aromatic or alicyclic hydrocarbon group which may have a branched structure, and And m each independently represent a range of l>0 and m>0, A represents OH, Y or OZ, and B represents H, HY or Z. However, at least one of A and B is represented. Is Y, OZ, HY or Z. Y represents a residue obtained by removing at least one H of OH from the compound having the structure represented by the general formula (3) and/or its condensate. Represents a residue obtained by ring-opening at least one epoxy group of OM in the compound having the structure represented by the general formula (3) and/or its condensate, wherein H and Y of HY are hydrogen bonds. In the general formula (3), X ^{1 to} X ⁶ may be the same or different and represent OH, CH ₃ or OM, provided that at least one of X ^{1 to} X ⁶ is OM. Further, M represents an organic group having an epoxy group, and n represents a range of 0 to 20.)
[6] A modified polyamide resin composition obtained by further mixing the modified polyamide resin according to any one of [1] to [5] with a polyamide resin.
[7] A method for producing a modified polyamide resin, which comprises reacting (A) a polyamide resin, (B) an aliphatic compound having three or more hydroxyl groups, and (C) a compound having two or more epoxy groups. ) Reacting an amino terminal group and/or a carboxyl terminal group of a polyamide resin, (B) a hydroxyl group of an aliphatic compound having three or more hydroxyl groups, and (C) an epoxy group of a compound having two or more epoxy groups. A method for producing a modified polyamide resin, wherein the reaction rate of a carboxyl end group and a hydroxyl group is 0.1 to 30%.
[8] A plurality of kneading zones and a plurality of full flight zones each containing at least the (A) polyamide resin, (B) an aliphatic compound having three or more hydroxyl groups, and (C) a compound having two or more epoxy groups. Is a method for producing a modified polyamide resin by melt-kneading using a twin-screw extruder having a plurality of kneading zones, the maximum resin pressure Pkmax (MPa) of the kneading zones and the full flight of the plurality of points. The method for producing a modified polyamide resin according to any one of [1] to [5], wherein Pfmin (MPa) is the minimum resin pressure among the resin pressures in the zones, and Pkmax≧Pfmin+0.3.
[9] A molded product obtained by molding the modified polyamide resin according to any one of [1] to [5] or the modified polyamide resin composition according to [6].

The modified polyamide resin of the present invention can provide a molded article having excellent retention stability, heat aging resistance, surface appearance, dimensional accuracy, chemical resistance, and creep resistance.

¹ H-NMR spectrum of the modified polyamide resin obtained in Example 2. ¹ H-NMR spectrum of a chloroform-unextracted component when the dimethylsulfoxide-extracted component of the modified polyamide resin obtained in Example 2 was further extracted with chloroform.

Hereinafter, embodiments of the present invention will be described in detail. The modified polyamide resin of the embodiment of the present invention includes (A) a polyamide resin, (B) an aliphatic compound having three or more hydroxyl groups (hereinafter sometimes referred to as “hydroxyl group-containing aliphatic compound”) and (C ) Amino terminal group and/or carboxyl terminal group of (A) polyamide resin obtained by reacting a compound having two or more epoxy groups (hereinafter sometimes referred to as “(C) epoxy compound”) , (B) the hydroxyl group of the hydroxyl group-containing aliphatic compound and the epoxy group of the (C) epoxy compound react with each other, and the reaction rate between the carboxyl terminal group and the hydroxyl group is 0.1 to 30%. The modified polyamide resin of the embodiment of the present invention is obtained by reacting (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound, and has a reaction rate of a carboxyl terminal group and a hydroxyl group. In the range of 0.1 to 30%, in addition to the reaction products obtained by reacting all of (A) to (C), unreacted (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound, (C) epoxy A compound and/or a reactant obtained by reacting only two of these three components are included. Unless otherwise specified, the modified polyamide resins of the present embodiments represent mixtures of these. Hereinafter, each component constituting the modified polyamide resin will be described.

The carboxyl group at the carboxyl terminal of the (A) polyamide resin used in the modified polyamide resin of the embodiment of the present invention undergoes a dehydration condensation reaction with the hydroxyl group in the (B) hydroxyl group-containing aliphatic compound described below, and also described below (C ) It is considered that an epoxy ring-opening reaction occurs with the epoxy group of the epoxy compound. Further, it is considered that the amino group at the amino terminal of the (A) polyamide resin is hydrogen-bonded to the hydroxyl group in the (B) hydroxyl group-containing aliphatic compound and also causes an epoxy ring-opening reaction with the epoxy group of the (C) epoxy compound. To be

The (A) polyamide resin used in the embodiment of the present invention is a polyamide containing (i) an amino acid, (ii) a lactam or (iii) a diamine and a dicarboxylic acid as main raw materials. As typical examples of the raw material of the (A) polyamide resin, amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and paraaminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, Tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-/2,4,4-trimethyl Hexamethylenediamine, 5-methylnonamethylenediamine, 2-methyloctamethylenediamine, and other aliphatic diamines, metaxylylenediamine, paraxylylenediamine, and other aromatic diamines, 1,3-bis(aminomethyl)cyclohexane, 1 , 4-bis(aminomethyl)cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, Aliphatic diamines such as 2,2-bis(4-aminocyclohexyl)propane, bis(aminopropyl)piperazine, and aminoethylpiperazine, aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid. Acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodiumsulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid Alicyclic dicarboxylic acids such as aromatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid. .. In the embodiment of the present invention, as a raw material of the (A) polyamide resin, two or more kinds of polyamide homopolymers or polyamide copolymers derived from these raw materials may be blended.

Specific examples of the polyamide resin include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), polytetramethylene sebacamide (nylon 410). , Polypentamethylene adipamide (nylon 56), polypentamethylene sebacamide (nylon 510), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polydecamethylene adipamide (Nylon 106), polydecamethylene sebacamide (nylon 1010), polydecamethylene dodecamide (nylon 1012), polyundecane amide (nylon 11), polydodecane amide (nylon 12), polycaproamide/polyhexamethylene azide Pamide copolymer (nylon 6/66), polycaproamide/polyhexamethylene terephthalamide copolymer (nylon 6/6T), polyhexamethylene adipamide/polyhexamethylene terephthalamide copolymer (nylon 66/6T), polyhexamethylene Adipamide/polyhexamethylene isophthalamide copolymer (nylon 66/6I), polyhexamethylene terephthalamide/polyhexamethylene isophthalamide copolymer (nylon 6T/6I), polyhexamethylene terephthalamide/polyundecane amide copolymer (nylon 6T/ 11), polyhexamethylene terephthalamide/polydodecane amide copolymer (nylon 6T/12), polyhexamethylene adipamide/polyhexamethylene terephthalamide/polyhexamethylene isophthalamide copolymer (nylon 66/6T/6I), polyxylyl Lenadipamide (nylon XD6), polyxylylene sebacamide (nylon XD10), polyhexamethylene terephthalamide/polypentamethylene terephthalamide copolymer (nylon 6T/5T), polyhexamethylene terephthalamide/poly-2-methyl Pentamethylene terephthalamide copolymer (nylon 6T/M5T), polypentamethylene terephthalamide/polydecamethylene terephthalamide copolymer (nylon 5T/10T), polynonamethylene terephthalamide (nylon 9T), polydecamethylene terephthalamide (nylon 10T) , Polydodecamethylene terephthalamide (nylon 12T) and the like. In addition, specific examples of the polyamide resin also include a mixture thereof and a copolymer. Here, “/” indicates a copolymer. The same applies hereinafter.

A particularly preferred polyamide resin is a polyamide resin having a melting point of 240°C to 330°C. A polyamide resin having a melting point of 240°C to 330°C has excellent heat resistance and strength. A polyamide resin having a melting point of 240° C. or higher can be melt-kneaded under a high resin pressure under high temperature conditions. Therefore, the reactivity of the amino terminal group and/or the carboxyl terminal group of the (A) polyamide resin with the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound and the epoxy group of the (C) epoxy compound is further enhanced, and retention stability is improved. , Heat aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance can be further improved. The melting point of the polyamide resin is more preferably 250° C. or higher. On the other hand, by using a polyamide resin having a melting point of 330° C. or lower, the melt-kneading temperature can be appropriately suppressed and the decomposition of the polyamide resin can be suppressed. Therefore, retention stability, heat aging resistance, dimensional accuracy, and creep resistance can be further improved. Here, the melting point of the polyamide resin in the embodiment of the present invention is measured by using a differential scanning calorimeter after cooling the polyamide resin from the molten state to 30° C. at a temperature decreasing rate of 20° C./min. , The temperature of the endothermic peak that appears when the temperature is raised to the melting point +40° C. at a heating rate of 20° C./min. However, when two or more endothermic peaks are detected, the temperature of the endothermic peak having the highest peak intensity is taken as the melting point.

Examples of the polyamide resin having a melting point of 240° C. to 330° C. include nylon 66, nylon 46, nylon 410, nylon 56, nylon 6T/66, nylon 6T/6I, nylon 6T/12, nylon 6T/5T, nylon 6T. /M5T, nylon 6T/6 and other copolymers having a hexamethyl terephthalamide unit, nylon 5T/10T, nylon 9T, nylon 10T, nylon 12T and the like.

It is also practically preferable to blend two or more of these polyamide resins in accordance with the required properties such as retention stability, heat aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance. It is preferable to mix nylon 6, nylon 11 and/or nylon 12 with a polyamide resin having a melting point of 240° C. to 330° C., which can further improve the heat aging resistance of the molded product. In this case, the total compounding amount of nylon 6, nylon 11 and nylon 12 is preferably 5 to 55 parts by weight with respect to 100 parts by weight of the polyamide resin having a melting point of 240°C to 330°C.

The degree of polymerization of these polyamide resins is not particularly limited, but the relative viscosity (ηr) measured at 25° C. in a 98% concentrated sulfuric acid solution having a resin concentration of 0.01 g/ml is in the range of 1.5 to 5.0. Preferably. When the relative viscosity is 1.5 or more, the heat aging resistance and chemical resistance of the obtained molded product can be further improved. The relative viscosity is more preferably 2.0 or more. On the other hand, when the relative viscosity is 5.0 or less, the moldability is excellent because the fluidity is excellent.

The (B) hydroxyl group-containing aliphatic compound used in the embodiment of the present invention means an aliphatic compound having three or more hydroxyl groups in one molecule. It is considered that the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound undergoes a dehydration condensation reaction with the carboxyl terminal carboxyl group of the (A) polyamide resin, and also forms a hydrogen bond with the amino terminal amino group of the (A) polyamide resin. Furthermore, it is considered that an epoxy ring-opening reaction with the epoxy group of the (C) epoxy compound described below occurs. The aliphatic compound having less than 3 hydroxyl groups in one molecule is reactive with the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound and the carboxyl terminal group of the (A) polyamide resin or the epoxy group of the (C) epoxy compound. Therefore, the heat aging resistance, surface appearance, dimensional accuracy, chemical resistance, and creep resistance of the obtained molded product deteriorate. The number of hydroxyl groups in one molecule is preferably 4 or more, and more preferably 6 or more. Since an aromatic compound or alicyclic compound having three or more hydroxyl groups in one molecule has high steric hindrance, (B) a hydroxyl group of a hydroxyl group-containing aliphatic compound and (A) a carboxyl terminal group of a polyamide resin or (C) The reactivity of the epoxy compound with the epoxy group cannot be increased. Therefore, the heat aging resistance, surface appearance, dimensional accuracy, chemical resistance, and creep resistance of the obtained molded product are deteriorated.

In the case of a low molecular weight compound, the number of hydroxyl groups in one molecule can be calculated by specifying the structural formula of the compound by a usual analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.). .. Further, in the case of a polymer, the number average molecular weight and the hydroxyl value of the (B) hydroxyl group-containing aliphatic compound can be calculated and determined by the following formula (4).
Number of OH=(number average molecular weight×hydroxyl value)/56110 (4).

The (B) hydroxyl group-containing aliphatic compound may be a low molecular weight compound or a polymer. Specific examples of the hydroxyl group-containing aliphatic compound include 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,3,6-hexanetetrol, Glycerin, diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, ditrimethylolpropane, tritrimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, triethanolamine , Trimethylolethane, trimethylolpropane, 2-methylpropanetriol, trishydroxymethylaminomethane, 2-methyl-1,2,4-butanetriol, and the like. Further, the hydroxyl group-containing aliphatic compound may also include a hydroxyl group-containing aliphatic compound having a repeating structural unit, for example, an ester bond, an amide bond, an ether bond, a methylene bond, a vinyl bond, an imine bond, a siloxane bond, a urethane bond. , A hydroxyl group-containing aliphatic compound having a repeating structural unit having a thioether bond, a silicon-silicon bond, a carbonate bond, a sulfonyl bond, and an imide bond. The hydroxyl group-containing aliphatic compound may contain a repeating structural unit containing two or more of these bonds. As the hydroxyl group-containing aliphatic compound, a hydroxyl group-containing aliphatic compound having a repeating structural unit having an ester bond, an ether bond and/or an amide bond is more preferable.

The hydroxyl group-containing aliphatic compound having a repeating structural unit having an ester bond is, for example, an aliphatic compound having one or more hydroxyl groups, in which a carbon atom adjacent to a carboxyl group is a saturated carbon atom, and a hydrogen atom on the carbon atom is present. It can be obtained by reacting a monocarboxylic acid in which all the atoms are substituted and which has two or more hydroxyl groups. The hydroxyl group-containing aliphatic compound having a repeating structural unit having an ether bond can be obtained, for example, by ring-opening polymerization of an aliphatic compound having one or more hydroxyl groups and a cyclic ether compound having one or more hydroxyl groups. The hydroxyl group-containing aliphatic compound having a repeating structural unit having an ester bond and an amide bond can be obtained, for example, by a polycondensation reaction of an aliphatic aminodiol and a cyclic acid anhydride. The hydroxyl group-containing aliphatic compound having a repeating structural unit having an amino group-containing ether bond can be obtained, for example, by intermolecular condensation of trialkanolamine. The hydroxyl group-containing aliphatic compound composed of a repeating structural unit having a carbonate bond can be obtained, for example, by a polycondensation reaction of an aryl carbonate derivative of an aliphatic polyhydric alcohol.

Among the hydroxyl group-containing aliphatic compounds, pentaerythritol, dipentaerythritol, and tripentaerythritol are preferable.

The molecular weight of the hydroxyl group-containing aliphatic compound used in the embodiment of the present invention is not particularly limited, but is preferably in the range of 50 to 10,000. When the molecular weight of the hydroxyl group-containing aliphatic compound is 50 or more, it is difficult to volatilize during melt-kneading, so that the processability is excellent. The molecular weight of the hydroxyl group-containing aliphatic compound is preferably 150 or more, more preferably 200 or more. On the other hand, when the molecular weight of the hydroxyl group-containing aliphatic compound is 10,000 or less, the reactivity between the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound and the carboxyl terminal group of the (A) polyamide resin becomes higher, and thus The effect is more prominent. The molecular weight of the hydroxyl group-containing aliphatic compound is preferably 6000 or less, more preferably 4000 or less, still more preferably 800 or less.

The molecular weight of the hydroxyl group-containing aliphatic compound can be calculated by specifying the structural formula of the compound by a usual analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.). When the hydroxyl group-containing aliphatic compound is a condensate, the weight average molecular weight determined by gel permeation chromatography (GPC) is used as the molecular weight. When the weight average molecular weight is measured by GPC, a solvent in which the compound is dissolved, for example, hexafluoroisopropanol is used as a mobile phase, polymethylmethacrylate (PMMA) is used as a standard substance, and the column is matched with the solvent, for example, hexafluoroisopropanol is used. For the measurement, "Shodex GPC HFIP-806M" and/or "Shodex GPC HFIP-LG" manufactured by Shimadzu GC Co., Ltd. can be used, and a differential refractometer can be used as a detector.

The hydroxyl value of the hydroxyl group-containing aliphatic compound used in the embodiment of the present invention is 100 to 2000 mgKOH/g from the viewpoint of reactivity with the carboxyl terminal group of the (A) polyamide resin and the epoxy group of the (C) epoxy compound. preferable. By setting the hydroxyl value of the hydroxyl group-containing aliphatic compound to 100 mgKOH/g or more, it becomes easy to secure a sufficient amount of reaction with the carboxyl terminal group of the (A) polyamide resin and the epoxy group of the (C) epoxy compound. Therefore, the heat aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance of the obtained molded product can be further improved. The hydroxyl value of the hydroxyl group-containing aliphatic compound is more preferably 300 mgKOH/g or more. On the other hand, when the hydroxyl value of the hydroxyl group-containing aliphatic compound is 2000 mgKOH/g or less, the reactivity with the carboxyl terminal group of the (A) polyamide resin and the epoxy group of the (C) epoxy compound is moderately increased, and the obtained molding is obtained. The heat aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance of the product can be further improved. Further, gelation due to excessive reaction can be suppressed. The hydroxyl value of the hydroxyl group-containing aliphatic compound is more preferably 1800 mgKOH/g or less.

The hydroxyl value can be determined by acetylating a hydroxyl group-containing aliphatic compound with a mixed solution of acetic anhydride and anhydrous pyridine, and titrating it with an ethanolic potassium hydroxide solution.

The degree of branching of the hydroxyl group-containing aliphatic compound used in the embodiment of the present invention is not particularly limited, but is preferably 0.05 to 0.35. The degree of branching is a numerical value indicating the degree of branching in the compound. A linear compound has a degree of branching of 0, and a fully branched dendrimer has a degree of branching of 1. The larger this value, the more the crosslinked structure can be introduced into the modified polyamide resin, and the more the mechanical properties of the molded product can be improved. When the branching degree is 0.05 or more, the crosslinked structure in the modified polyamide resin is sufficiently formed, and the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product are further improved. The branching degree is preferably 0.10 or more. On the other hand, by setting the degree of branching to 0.35 or less, the crosslinked structure in the modified polyamide resin can be appropriately suppressed, and the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product can be further improved. .. The branching degree is preferably 0.31 or less.

The branching degree is defined by the following equation (5).
Branching degree=(D+T)/(D+T+L) (5)
In the above formula (5), D represents the number of dendritic units, L represents the number of linear units, and T represents the number of terminal units. The above D, T, and L can be calculated from the integrated value of the peak shift measured by ¹³ C-NMR. D is derived from a tertiary or quaternary carbon atom, T is derived from a primary carbon atom which is a methyl group, and L is a primary or secondary carbon atom, Derived from those excluding T.

The (B) hydroxyl group-containing aliphatic compound used in the embodiment of the present invention may have other functional groups in addition to the hydroxyl groups. Examples of other functional groups include amino groups, aldehyde groups, sulfo groups, glycidyl groups, isocyanate groups, carbodiimide groups, oxazoline groups, oxazine groups, ester groups, amide groups, silanol groups, silyl ether groups, and the like.

In the modified polyamide resin of the embodiment of the present invention, the reaction rate between the carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound is 0.1 to 30%. If the reaction rate is less than 0.1%, the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product deteriorate. Further, bleed-out of the (B) hydroxyl group-containing aliphatic compound to the surface layer of the molded product occurs, and the surface appearance deteriorates. 1% or more is preferable. On the other hand, when the reaction rate is higher than 30%, gelation occurs due to excessive reaction, and the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product deteriorate. 20% or less is preferable. The (C) epoxy compound, which will be described later, serves as a binder for the (A) polyamide resin and the (B) hydroxyl group-containing aliphatic compound, and is therefore effective in increasing the reaction rate.

In the modified polyamide resin of the embodiment of the present invention, the reaction rate between the carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound can be calculated by ¹ H-NMR analysis. This reaction is represented by the peak shift of the proton of the hydrocarbon bonded to the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound due to the reaction with the carboxyl terminal group of the (A) polyamide resin. Specifically, first, the (A) polyamide resin, the (B) hydroxyl group-containing aliphatic compound, and the (C) epoxy compound used in the reaction are specified from the structure of the modified polyamide resin. A dry blend of (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound is dissolved in a solvent (for example, deuterated sulfuric acid), and ¹ H-NMR measurement is performed, (B) The peak of the proton of the hydrocarbon bonded to the hydroxyl group of the hydroxyl group-containing aliphatic compound is identified. Next, the modified polyamide resin is dissolved in a solvent (for example, deuterated sulfuric acid) and ¹ H-NMR measurement is performed, and the peak of the proton of the hydrocarbon bonded to the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound is ( A) It can be determined by the following formula (6) by determining the peak-shifted peak area by the reaction with the carboxyl terminal group of the polyamide resin.
Reaction rate (%)={b/(a+b)}×100 (6)
In the above formula (6), a represents the peak area of the proton of the hydrocarbon bonded to the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound that has not reacted with the carboxyl terminal group of the (A) polyamide resin, and b represents the reaction. The peak area of the proton of the hydrocarbon bonded to the hydroxyl group derived from the (B) hydroxyl group-containing aliphatic compound that has been peak-shifted is shown.

As an example, the ¹ H-NMR spectrum of the modified polyamide resin obtained in Example 2 described later is shown in FIG. Bisulfuric acid was used as a solvent, the sample amount was 0.05 g, and the solvent amount was 1.00 ml.

From the ¹ H-NMR spectrum shown in FIG. 1, the peak area (b) of the proton of the hydrocarbon bonded to the hydroxyl group derived from the (B) hydroxyl group-containing aliphatic compound, which appears in the vicinity of 4.60 ppm, is shown in FIG. The peak area (a) of the protons of the hydrocarbons bonded to the hydroxyl groups of the unreacted (B) hydroxyl group-containing aliphatic compound, which appears near 10 ppm, is obtained, and the reaction rate is calculated from the reaction rate calculation formula (6). To do. In FIG. 1, reference numeral 1 indicates that the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound and the carboxyl terminal group of the (A) polyamide resin undergo an ester reaction.

The (C) epoxy compound used in the modified polyamide resin of the embodiment of the present invention refers to a compound having two or more epoxy groups in one molecule. It is considered that the epoxy group of the epoxy compound (C) causes an epoxy ring-opening reaction with the amino terminal group and/or the carboxyl terminal group of the polyamide resin (A). Further, it is considered that an epoxy ring-opening reaction occurs with the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound. (A) Reactivity of amino terminal group and/or carboxyl terminal group of polyamide resin with epoxy group of (C) epoxy compound and reaction of (B) hydroxyl group of aliphatic compound containing hydroxyl group with epoxy group of (C) epoxy compound The reactivity is higher than the reactivity between the amino terminal group and/or the carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound. Therefore, the epoxy compound (C) plays a role of a binder for the polyamide resin (A) and the aliphatic compound (B) having a hydroxyl group, and the epoxy compound (A) has an amino terminal group and/or a carboxyl terminal group (B). ) It is considered to have the effect of increasing the reactivity of the hydroxyl group-containing aliphatic compound with the hydroxyl group. When the number of epoxy groups in one molecule is less than 2, the (C) epoxy compound does not serve as a binder between the (A) polyamide resin and the (B) hydroxyl group-containing aliphatic compound. Therefore, the reactivity between the amino terminal group and/or the carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound cannot be increased, and the (B) hydroxyl group-containing aliphatic compound is molded. Bleed-out to the surface layer of the product is likely to occur, resulting in a poor surface appearance. Further, the heat-aging resistance, dimensional accuracy, chemical resistance and creep resistance of the obtained molded product are deteriorated.

In the case of a low molecular weight compound, the number of epoxy groups in one molecule can be calculated by specifying the structural formula of the compound by a usual analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.). it can. In the case of a polymer, when the ratio of the epoxy group-containing monomer contained in the polymer is a% by weight, the number average molecular weight of the polymer is b, and the molecular weight of the epoxy group-containing monomer is c, the epoxy The average number of groups=(a/100)×b/c.

The (C) epoxy compound may be a low molecular weight compound or a polymer. Specific examples of the epoxy compound (C) include epichlorohydrin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, glycidyl group-containing vinyl type. Examples thereof include polymers. You may use 2 or more types of these.

Examples of the glycidyl ether type epoxy resin include those produced from epichlorohydrin and bisphenol A, those produced from epichlorohydrin and bisphenol F, and phenol novolac type epoxy resins obtained by reacting novolac resin with epichlorohydrin. , Orthocresol novolac type epoxy resin, so-called brominated epoxy resin derived from epichlorohydrin and tetrabromobisphenol A, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol polyglycidyl ether and the like.

As the glycidyl ester type epoxy resin, an epoxy resin produced from epichlorohydrin and phthalic acid, tetrahydrophthalic acid, p-oxybenzoic acid or dimer acid, trimesic acid triglycidyl ester, trimellitic acid triglycidyl ester, pyro An example is meritic acid tetraglycidyl ester.

Examples of the glycidylamine type epoxy resin include an epoxy resin produced from epichlorohydrin and aniline, diaminodiphenylmethane, p-aminophenol, metaxylylenediamine or 1,3-bis(aminomethyl)cyclohexane, tetraglycidylaminodiphenylmethane. , Triglycidyl-paraaminophenol, triglycidyl-metaaminophenol, tetraglycidyl metaxylenediamine, tetraglycidyl bisaminomethylcyclohexane, triglycidyl cyanurate, triglycidyl isocyanurate and the like.

Examples of the alicyclic epoxy resin include compounds having a cyclohexene oxide group, a tricyclodecene oxide group, and a cyclopentene oxide group. Examples of the heterocyclic epoxy resin include an epoxy resin produced from epichlorohydrin and hydantoin or isocyanuric acid.

Examples of the glycidyl group-containing vinyl polymer include those obtained by radical polymerization of raw material monomers forming the glycidyl group-containing vinyl unit. Specific examples of the raw material monomer forming the glycidyl group-containing vinyl unit include glycidyl (meth)acrylate, glycidyl ester of unsaturated monocarboxylic acid such as glycidyl p-styrylcarboxylate, unsaturated acid such as maleic acid and itaconic acid. Examples thereof include monoglycidyl esters or polyglycidyl esters of polycarboxylic acids, unsaturated glycidyl ethers such as allyl glycidyl ether, 2-methylallyl glycidyl ether, and styrene-4-glycidyl ether.

(C) Commercially available epoxy compounds include polyglycidyl ether compounds that are low-molecular polyfunctional epoxy compounds (for example, "SR-TMP" manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., "Denacol" manufactured by Nagase Chemtex Co., Ltd.). "(Registered trademark) EX-521"), a polyfunctional epoxy compound containing polyethylene as a main component (for example, "Bond Fast" (registered trademark) E" manufactured by Sumitomo Chemical Co., Ltd.), and an acryl main component. Polyfunctional epoxy compound (for example, “Reseda” (registered trademark) GP-301 manufactured by Toagosei Co., Ltd., “ARUFON” (registered trademark) UG-4000 manufactured by Toagosei Co., Ltd., Mitsubishi Rayon Co., Ltd.) "Metablene (registered trademark) KP-7653" and the like, a polyfunctional epoxy compound containing an acrylic/styrene copolymer as a main component (for example, ""Joncryl" (registered trademark)-ADR-4368" manufactured by BASF). , "ARUFON" (registered trademark) UG-4040 manufactured by Toagosei Co., Ltd.), and a polyfunctional epoxy compound containing a silicone-acrylic copolymer as a main component (for example, ""Metablen" (registered trademark) S-). 2200"), a polyfunctional epoxy compound containing polyethylene glycol as a main component (for example, "Epiol" (registered trademark) "E-1000" manufactured by NOF CORPORATION), a bisphenol A type epoxy resin (for example, Mitsubishi Chemical) Examples include "jER" (registered trademark) "1004" manufactured by Co., Ltd.) and novolac phenol type modified epoxy resin (for example, "EPPN" (registered trademark) "201" manufactured by Nippon Kayaku Co., Ltd.).

In the embodiment of the present invention, the molecular weight of the (C) epoxy compound is preferably in the range of 800 to 10,000. When the molecular weight of the epoxy compound (C) is 800 or more, it is less likely to volatilize during melt-kneading, resulting in excellent processability. Further, since the viscosity at the time of melt-kneading can be increased, the reactivity between the carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound becomes higher, and the dimensional accuracy of the obtained molded product is improved. , Further improves chemical resistance and creep resistance. Further, when a 3.2 mm thick ASTM No. 1 dumbbell obtained by injection molding the modified polyamide resin of the embodiment of the present invention described later was heat-treated at 130° C. for 180 hours in the atmosphere, the surface of the molded product was 0. Since the increase in the concentration of the carboxyl end group in the modified polyamide resin having a depth of up to 2 mm after heat treatment can be suppressed to less than 4.0×10 ⁻⁵ mol/g, the heat aging resistance of the molded product is further improved. .. The molecular weight of the epoxy compound (C) is more preferably 1,000 or more, still more preferably 2,000 or more. By setting the molecular weight of the (C) epoxy compound to 2000 or more, it is possible to further suppress the bleed-out of the (B) hydroxyl group-containing aliphatic compound to the surface layer of the molded product and further improve the surface appearance even at the time of wet heat treatment. it can. On the other hand, when the molecular weight of the (C) epoxy compound is 10,000 or less, the viscosity at the time of melt-kneading can be appropriately suppressed, so that the processability is excellent. Further, the reactivity with the amino terminal group and/or the carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound can be kept high. The molecular weight of the (C) epoxy compound is more preferably 8,000 or less.

The molecular weight of the epoxy compound (C) can be calculated by identifying the structural formula of the compound by a usual analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.). When the hydroxyl group-containing aliphatic compound is a condensate, the weight average molecular weight determined by gel permeation chromatography (GPC) is used as the molecular weight. When the weight average molecular weight is measured by GPC, a solvent in which a compound is dissolved, for example, hexafluoroisopropanol is used as a mobile phase, polymethylmethacrylate (PMMA) is used as a standard substance, and a column is matched with the solvent, for example, hexafluoroisopropanol is used. For the measurement, "Shodex GPC HFIP-806M" and/or "Shodex GPC HFIP-LG" manufactured by Shimadzu GC Co., Ltd. can be used, and a differential refractometer can be used as a detector.

The (C) epoxy compound used in the embodiment of the present invention is preferably a solid at 25° C. or a liquid having a viscosity of 200 mPa·s or more at 25° C. In that case, it becomes easy to obtain a desired viscosity during melt-kneading, and the reactivity between the amino terminal group and/or carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound becomes higher. .. Therefore, the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the obtained molded product are further improved.

The value obtained by dividing the molecular weight by the number of epoxy groups in one molecule, which is an index showing the epoxy group concentration of the (C) epoxy compound of the embodiment of the present invention, is preferably 50 to 3000. The smaller this value is, the higher the epoxy group concentration is. However, by setting it to 50 or more, gelation due to an excessive reaction can be suppressed, and (A) the polyamide resin may have an amino terminal group and/or a carboxyl terminal group. (B) Since the reaction of the hydroxyl group-containing aliphatic compound with the hydroxyl group is moderately enhanced, the retention stability is improved, and the heat-aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance of the resulting molded article are improved. Can be improved. The value obtained by dividing the molecular weight of the epoxy compound (C) by the number of epoxy groups in one molecule is more preferably 100 or more, still more preferably 1100 or more. By making the value obtained by dividing the molecular weight of the (C) epoxy compound by the number of epoxy groups in one molecule to be 1100 or more, the bleed-out of the (B) hydroxyl group-containing aliphatic compound to the surface layer of the molded product even during the wet heat treatment. Can be further suppressed and the surface appearance can be further improved. Further, by setting the value obtained by dividing the molecular weight of the (C) epoxy compound by the number of epoxy groups in one molecule to 3000 or less, (A) an amino terminal group and/or a carboxyl terminal group of the polyamide resin, and (B) The reaction of the hydroxyl group-containing aliphatic compound with the hydroxyl group can be sufficiently ensured, the retention stability is improved, and the heat-aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance of the resulting molded article are improved. Can be improved. From this viewpoint, the value obtained by dividing the molecular weight of the (C) epoxy compound by the number of epoxy groups in one molecule is preferably 2000 or less, more preferably 1000 or less.

The (B) hydroxyl group-containing aliphatic compound is effective in molding processability such as fluidity and improvement in heat aging resistance at 160 to 240° C., but 160° C. probably because it has low compatibility with the (A) polyamide resin. If it is less than 1, there is a problem that the heat aging resistance decreases. Further, the (B) hydroxyl group-containing aliphatic compound has a problem of bleeding out to the surface layer of the molded article, and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound accelerates the hydrolysis of the amide bond of the (A) polyamide resin and stays there. There are also issues that are less stable. Further, there is a problem that the (B) hydroxyl group-containing aliphatic compound plasticizes the (A) polyamide resin, and the dimensional accuracy, chemical resistance and creep resistance of the resulting molded article are reduced. However, in the modified polyamide resin of the embodiment of the present invention, by reacting the (C) epoxy compound with the (A) polyamide resin and the (B) hydroxyl group-containing aliphatic compound, the (C) epoxy compound becomes (A) polyamide. The resin plays a role of a binder between the (B) hydroxyl group-containing aliphatic compound and the reactivity of the (A) polyamide resin amino terminal group and/or carboxyl terminal group with the (B) hydroxyl group-containing aliphatic compound hydroxyl group. It is thought that it can be raised. Therefore, it is considered that bleeding out to the surface layer of the molded product can be suppressed, the surface appearance can be improved, and the heat aging resistance at 160° C. or lower can be improved. The (C) epoxy compound plays a role of a binder, whereby the hydrolysis of the amide bond of the (A) polyamide resin by the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound can be suppressed, and the residence stability can be improved. Since it is possible to suppress the plasticization of the (A) polyamide resin, it is considered that the dimensional accuracy, chemical resistance and creep resistance of the obtained molded product could be improved.

When a 3.2 mm thick ASTM No. 1 dumbbell obtained by injection molding the modified polyamide resin of the embodiment of the present invention was heat-treated at 130° C. for 180 hours in the atmosphere, a depth of 0.2 mm from the surface of the molded product was obtained. The increase in the concentration of carboxyl terminal groups in the modified polyamide resin after heat treatment is preferably 4×10 ⁻⁵ mol/g or less. When the increase in the carboxyl terminal group concentration is 4×10 ⁻⁵ mol/g or less, the heat aging resistance of the obtained molded product is further improved. The cause of this is not clear, but the decrease in heat aging resistance is due to the fact that when a molded product made of a polyamide resin is heated in the atmosphere, the polyamide resin on the surface of the molded product in contact with oxygen is oxidatively deteriorated to have a low molecular weight and become brittle. It is thought that this is due to However, when the modified polyamide resin is reduced in molecular weight, an increase in the carboxyl terminal group and the unreacted hydroxyl group and/or epoxy group in the modified polyamide resin react with each other to suppress the reduction in molecular weight of the modified polyamide resin, It is considered that it can maintain the heat aging resistance. That is, it is considered that if the increase in the carboxyl terminal group concentration in the modified polyamide resin after the heat treatment is suppressed, the reduction in the molecular weight of the polyamide resin can be suppressed.

The carboxyl terminal group concentration of the modified polyamide resin is 180° C. for 180 hours in the atmosphere, and the modified polyamide resin having a depth of 0.2 mm from the surface is cut using a milling machine. It can be determined by analysis by a known method such as a neutralization titration method.

Examples of the method for controlling the increase of the carboxyl terminal group concentration of the modified polyamide resin in the above range include, for example, a method using an epoxy compound (C) having a molecular weight of 800 or more, and a (B) hydroxyl group-containing aliphatic compound in producing a modified polyamide resin. Examples thereof include a method of blending the compound and the (C) epoxy compound in a preferable ratio described below. Although the factor that can suppress the increase in the concentration of the carboxyl end group by the former method is not clear, it is possible to increase the viscosity at the time of melt-kneading, and (A) contain the carboxyl end group of the polyamide resin and (B) contain the hydroxyl group. This is probably because the reactivity of the aliphatic compound with the hydroxyl group was further improved. Further, although the factor that can suppress the increase in the concentration of the carboxyl end group by the latter method is not clear, the unreacted epoxy group in the modified polyamide resin at the initial stage of the heat treatment is the amino end group and/or the carboxyl end group. Even if it reacts with the hydroxyl group, it is considered that the concentration of the hydroxyl group is sufficient to react with the carboxyl terminal group until the latter stage of the heat treatment.

In the modified polyamide resin of the embodiment of the present invention, the presence or absence of the reaction between the amino terminal group and/or the carboxyl terminal group of the (A) polyamide resin and the epoxy group of the (C) epoxy compound is determined by the following method. You can First, (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound used in the reaction are specified from the structure of the modified polyamide resin. A reaction product in which the (C) epoxy compound and the (B) hydroxyl group-containing aliphatic compound are soluble and (A) to (C) of the (A) polyamide resin and the modified polyamide resin all react (hereinafter, referred to as “( A) to (C) reaction product" may be referred to as "). The modified polyamide resin is extracted using an insoluble solvent, and the unextracted component is analyzed by ¹ H-NMR to obtain an epoxy compound-derived compound. The presence or absence of the reaction between the amino terminal group and/or the carboxyl terminal group and the epoxy group can be determined from the presence or absence of the peak. That is, since the unreacted (C) epoxy compound is extracted in the solvent and the reaction products of (A) to (C) are not extracted in the solvent, the peak derived from the epoxy compound is determined by ¹ H-NMR analysis of the unextracted components. Is detected, it means that the amino end group and/or the carboxyl end group and the epoxy group have reacted.

The reaction rate of the epoxy group with the amino terminal group and/or the carboxyl terminal group in the modified polyamide resin is preferably 0.1 to 95%. When the reaction rate is 0.1% or more, the reactivity of the (A) polyamide resin and the (B) hydroxyl group-containing aliphatic compound can be increased, and the heat-aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product can be increased. Sex is improved. 5% or more is preferable. When the reaction rate is 95% or less, gelation due to excessive reaction can be suppressed, and the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product are further improved. 80% or less is preferable.

The reaction rate of the epoxy group with the amino terminal group and/or the carboxyl terminal group can be calculated by the following method. First, (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound used in the reaction are specified from the structure of the modified polyamide resin. (C) Epoxy compound and (B) Hydroxyl group-containing aliphatic compound are soluble, and (A) Polyamide resin and the reaction products of (A) to (C) are insoluble using a solvent (for example, dimethyl sulfoxide). Extract the modified polyamide resin. By this operation, the unreacted (C) epoxy compound, the unreacted (B) hydroxyl group-containing aliphatic compound and the reaction product of the (B) hydroxyl group-containing aliphatic compound and the (C) epoxy compound are extracted into a solvent, ) The polyamide resin and the reaction products of (A) to (C) are not extracted. The components not extracted are dried to dryness, and the peak area derived from the (C) epoxy compound contained in the reaction products of (A) to (C) is determined by ¹ H-NMR measurement. Similarly, the modified polyamide resin is subjected to ¹ H-NMR measurement, and the peak area derived from the epoxy compound (C) is determined. At this time, the modified polyamide resin also contains unreacted (C) epoxy compound and a reaction product of (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound. The peak area is normalized by the proton peak of the methylene group derived from the polyamide resin, which does not affect the reaction or extraction. The reaction rate can be calculated by the following formula (7).
Reaction rate (%)=(b/a)×100 (7)
In the above formula (7), a represents the peak area derived from the (C) epoxy compound in the modified polyamide resin, b represents the modified polyamide resin, and the peak area derived from the (C) epoxy compound in the unextracted component. Represent

As an example, the ¹ H-NMR spectrum of the modified polyamide resin obtained in Example 2 described later is shown in FIG. Bisulfuric acid was used as a solvent, the sample amount was 0.05 g, and the solvent amount was 1.00 ml.

From the ¹ H-NMR spectrum shown in FIG. 1, the peak area of the benzene ring derived from the (C) epoxy compound appearing at around 8.0 ppm is determined. Next, 50 g of this modified polyamide resin was freeze-pulverized, extracted with 100 ml of dimethyl sulfoxide at 60° C. for 6 hours, and ¹ H-NMR measurement of the dry solid of the unextracted component was carried out. The peak area derived from the epoxy compound appearing in is calculated. Here, the peak area is normalized by the peak of the methylene group adjacent to the carbonyl group of the adipic acid site that appears near 2.25 ppm. The reaction rate is calculated from the above-mentioned reaction rate calculation formula (7).

In the modified polyamide resin of the embodiment of the present invention, the presence or absence of the reaction between the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound and the epoxy group of the (C) epoxy compound can be determined by the following method. First, (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound used in the reaction are specified from the structure of the modified polyamide resin. (C) Epoxy compound, (B) Hydroxyl group-containing aliphatic compound and the reaction product of (B) Hydroxyl group-containing aliphatic compound and (C) Epoxy compound are soluble, and (A) Polyamide resin and (A) to ( The modified C resin is extracted with a solvent (for example, dimethylsulfoxide) in which the reaction product of C) becomes insoluble, and the extract is dried to dryness, and the (C) epoxy compound is soluble and (A) polyamide. The resin, the reaction product of (A) to (C), the (B) hydroxyl group-containing aliphatic compound, and the reaction product of the (B) hydroxyl group-containing aliphatic compound and the (C) epoxy compound are insoluble solvents (for example, chloroform). The presence or absence of the reaction between the hydroxyl group and the epoxy group can be determined from the presence or absence of the peak derived from the epoxy compound (C) by performing extraction of the dried solid matter using ¹ ) and performing ¹ H-NMR analysis on the component that is not extracted. it can. That is, by the first extraction operation, the unreacted (B) hydroxyl group-containing aliphatic compound, unreacted (C) epoxy compound, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound are contained in the extract. Is present. Further, by performing a second extraction on this extract, the unreacted (C) epoxy compound is extracted into the solvent, and the unreacted (B) hydroxyl group-containing aliphatic compound and (B) hydroxyl group-containing aliphatic compound. Since the reaction product of (C) epoxy compound and (C) epoxy compound is not extracted in the solvent, if a peak derived from the epoxy compound can be detected by ¹ H-NMR analysis of the unextracted product, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound Means that they are reacting.

In the modified polyamide resin, when the reaction between the hydroxyl group and the epoxy group occurs, the reactivity of the (A) polyamide resin and the (B) hydroxyl group-containing aliphatic compound can be increased, and the heat aging resistance, dimensional accuracy, and resistance of the molded product can be improved. Improves chemical resistance and creep resistance.

As an example, 50 g of the modified polyamide resin of Example 2 to be described later is freeze-pulverized and extracted with 100 ml of dimethyl sulfoxide at 60° C. for 6 hours. Extraction was performed at 6° C. for 6 hours, and the ¹ H-NMR spectrum of a dry solid of the unextracted component is shown in FIG. Deuterated dimethyl sulfoxide was used as the solvent, the sample amount was 0.035 g, and the solvent amount was 0.70 ml. Reference numeral 2 indicates a solvent peak.

From the ¹ H-NMR spectrum shown in FIG. 2, a proton peak of the benzene ring derived from the epoxy compound (C), which appears near 6.8 ppm, is detected.

In the embodiment of the present invention, the modified polyamide resin preferably has a structure represented by the following general formula (1) or the following general formula (2).

In the general formula (1) and the general formula (2), R ^{1 to} R ³ each independently represent an aliphatic, aromatic or alicyclic hydrocarbon group which may have a branched structure, and l and m independently represents a range of l>0 and m>0. A represents OH, Y or OZ, and B represents H, HY or Z. However, at least one of A and B is Y, OZ, HY or Z. Y represents a residue obtained by removing H of at least one OH from the compound having the structure represented by the above general formula (3) and/or its condensate. Z represents a ring-opening residue of at least one epoxy group of OM in the compound having the structure represented by the general formula (3) and/or its condensate. 1 Here, H and Y ² of HY ² are bonded by a hydrogen bond. In the general formula (3), X ^{1 to} X ⁶ may be the same or different and each represents OH, CH ₃ or OM. However, at least one of X ^{1 to} X ⁶ is OM. Moreover, M represents the organic group which has an epoxy group, and n represents the range of 0-20.

In the general formula (1) and the general formula (2), R ^{1 to} R ³ each independently represent an aliphatic, aromatic or alicyclic hydrocarbon group which may have a branched structure. The hydrocarbon group preferably has 4 to 20 carbon atoms.

In the general formula (1) and the general formula (2), l and m each independently represent a range of l>0 and m>0. Although there is no upper limit to l and m, the relative viscosity (ηr) of the modified polyamide resin measured at 25° C. in a 98% concentrated sulfuric acid solution with a resin concentration of 0.01 g/ml is in the range of 1.5 to 5.0. Is preferred. When the relative viscosity is 1.5 or more, the mechanical properties of the obtained molded product can be further improved. The relative viscosity is more preferably 2.0 or more. On the other hand, when the relative viscosity is 5.0 or less, the moldability is excellent because the fluidity is excellent.

In general formula (1) and general formula (2), A represents OH, Y or OZ, and B represents H, HY or Z. However, at least one of A and B is Y, OZ, HY or Z. That at least one of A and B is Y, OZ, HY or Z means that (A) the amino terminal group and/or the carboxyl terminal group of the polyamide resin is (B) the hydroxyl group of the hydroxyl group-containing aliphatic compound and/or (C) Means that the epoxy group reacts with the epoxy group of the epoxy compound, and the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product can be further improved.

In general formulas (1) and (2), Y represents a residue obtained by removing at least one H of OH from the compound having the structure represented by general formula (3) and/or its condensate. Having such a residue means that the carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound have reacted, and the heat aging resistance of the molded article, dimensional accuracy, chemical resistance Resistance and creep resistance can be further improved. Further, H and Y of HY are bonded by a hydrogen bond.

In general formula (1) and general formula (2), Z is a compound having a structure represented by general formula (3) and/or a condensate thereof, which is a residue obtained by ring-opening at least one epoxy group of OM. Represent Having such a residue means that the amino terminal group and/or the carboxyl terminal group of the (A) polyamide resin and the epoxy group of the (C) epoxy compound are reacting with each other. The accuracy, chemical resistance and creep resistance can be further improved.

In the general formula (3), X ^{1 to} X ⁶ may be the same or different and represent OH, CH ₃ or OM, and at least one is OM. Having one or more OM means that the hydroxyl groups of the (B) hydroxyl group-containing aliphatic compound and the epoxy groups of the (C) epoxy compound are reacting, and the heat aging resistance, dimensional accuracy, and chemical resistance of the molded product are high. Resistance and creep resistance can be further improved. Further, M represents an organic group having an epoxy group. Examples of the organic group having an epoxy group include an epoxy group, a glycidyl group, a glycidyl ether type epoxy group, a glycidyl ester type epoxy group, a glycidyl amine type epoxy group, an epoxy group or a hydrocarbon group substituted with a glycidyl group, an epoxy group. Alternatively, a heterocyclic group substituted with a glycidyl group and the like can be mentioned.

In general formula (3), n represents the range of 0-20. When n is 20 or less, plasticization of the (A) polyamide resin is suppressed, and heat aging resistance, chemical resistance and creep resistance can be further improved. n is more preferably 4 or less, and can further improve the heat aging resistance, chemical resistance and creep resistance. On the other hand, n is more preferably 1 or more, and the reactivity between the carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound can be further improved.

Since the modified polyamide resin has an appropriate branched structure by having the structure represented by the general formula (1) or the general formula (2), the heat-aging resistance of the molded product, dimensional accuracy, chemical resistance and Creep resistance is further improved. Further, the reactivity between the carboxyl terminal group of the (A) polyamide resin and the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound can be increased. Although this factor is not clear, the structure represented by the general formula (3) represents a part of the reaction product of the (B) hydroxyl group-containing aliphatic compound and the (C) epoxy compound, but the structure is branched. It is considered that the self-cohesive force is reduced by having the structure, and the reactivity with the (A) polyamide resin is improved.

Next, a method for producing the modified polyamide resin of the embodiment of the present invention will be described. The modified polyamide resin of the embodiment of the present invention can be obtained by reacting the above-mentioned (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound. If necessary, other components may be further reacted.

The amount of the (B) hydroxyl group-containing aliphatic compound used for producing the modified polyamide resin of the embodiment of the present invention is preferably 0.1 to 150 parts by weight with respect to 100 parts by weight of the (A) polyamide resin. By using 0.1 part by weight or more of the (B) hydroxyl group-containing aliphatic compound, the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product can be further improved. 0.5 parts by weight or more is more preferable, and 2 parts by weight or more is further preferable. On the other hand, by using 150 parts by weight or less of the (B) hydroxyl group-containing aliphatic compound, it is possible to further suppress the bleed-out of the (B) hydroxyl group-containing aliphatic compound to the surface layer of the molded article and further improve the surface appearance. In addition, it is possible to further suppress plasticization and decomposition of the polyamide resin, and further improve retention stability, heat aging resistance of the molded product, dimensional accuracy, chemical resistance and creep resistance. It is more preferably 7.5 parts by weight or less, still more preferably 6 parts by weight or less.

The (C) epoxy compound used in the production of the modified polyamide resin of the embodiment of the present invention is preferably 0.001 to 50 parts by weight with respect to 100 parts by weight of the (A) polyamide resin. By using 0.001 part by weight or more of the (C) epoxy compound, the heat aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance of the molded product can be further improved. The amount is preferably 0.01 part by weight or more, and more preferably 0.1 part by weight or more. On the other hand, by using the epoxy compound (C) in an amount of 50 parts by weight or less, gelation can be suppressed, and retention stability, heat aging resistance of the molded product, dimensional accuracy, chemical resistance and creep resistance can be further improved. .. The amount is preferably 7 parts by weight or less, more preferably 5 parts by weight or less, still more preferably 3 parts by weight or less.

The ratio of the (B) hydroxyl group-containing aliphatic compound to the (C) epoxy compound used for producing the modified polyamide resin of the embodiment of the present invention is preferably 0.3 or more and less than 10,000. The reactivity of the (A) polyamide resin with the (C) epoxy compound and the reactivity of the (B) hydroxyl group-containing aliphatic compound with the (C) epoxy compound are the same as those of the (A) polyamide resin and the (B) hydroxyl group-containing aliphatic compound. Higher than sex. Therefore, by setting the ratio of the (B) hydroxyl group-containing aliphatic compound to the content of the (C) epoxy compound to 0.3 or more, generation of gel due to excessive reaction is suppressed, and the dimensional accuracy and resistance of the molded product are improved. The chemical resistance and creep resistance can be further improved. In addition, the increase in the carboxyl terminal group concentration after heat treatment can be suppressed to less than 4.0×10 ⁻⁵ mol/g, and the heat aging resistance of the molded product can be further improved. The ratio of the (B) hydroxyl group-containing aliphatic compound to the (C) epoxy compound is preferably more than 1. On the other hand, by setting the ratio of the (B) hydroxyl group-containing aliphatic compound to the (C) epoxy compound to less than 10,000, it is possible to suppress the deterioration of the retention stability due to the excessive presence of the (B) hydroxyl group-containing aliphatic compound. Further, the heat aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance of the molded product can be further improved. The ratio of the (B) hydroxyl group-containing aliphatic compound to the (C) epoxy compound is more preferably 10 or less.

As the method for producing the modified polyamide resin of the embodiment of the present invention, the above-mentioned (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound are reacted in a molten state or in a solution state. And the like. From the viewpoint of improving reactivity, a method of reacting in a molten state can be preferably used. As a method of reacting in a molten state, melt kneading by an extruder, melt kneading by a kneader, or the like can be used, but from the viewpoint of productivity, melt kneading by an extruder that can be continuously manufactured is preferable. For melt-kneading with an extruder, one or more extruders such as a single-screw extruder, a twin-screw extruder, a four-screw extruder or a multi-screw extruder, or a twin-screw single-screw extruder can be used. From the viewpoint of improving reactivity and productivity, a multi-screw extruder such as a twin-screw extruder or a four-screw extruder is preferable, and a method of melt-kneading using a twin-screw extruder is most preferable.

When melt-kneading using a twin-screw extruder, the raw material supply method to the twin-screw extruder is as follows: (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound from the upstream side of the extruder. The method of supplying is preferred. Here, the side of the twin-screw extruder to which the raw material is supplied is defined as upstream, and the side where the molten resin is discharged is defined as downstream.

The ratio (L/D) of the total screw length L and the screw diameter D of the twin-screw extruder is preferably 25 or more, and more preferably more than 30. When L/D is 25 or more, it becomes easy to sufficiently knead the (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound, and the heat aging resistance and size of the molded product. The accuracy, chemical resistance and creep resistance can be further improved.

In the embodiment of the present invention, at least (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound are supplied to the twin-screw extruder from the upstream side of 1/2 of the screw length. Melt-kneading is preferable, and it is more preferable to supply from the upstream end of the screw segment. The screw length here is the length from the upstream end of the screw segment at the position (feed port) where the raw material of the screw root is supplied to the screw tip. The upstream end of the screw segment refers to the position of the screw piece located at the most upstream end of the screw segment connected to the extruder.

When producing the modified polyamide resin of the embodiment of the present invention using a twin-screw extruder, a twin-screw extruder having a plurality of full flight zones and a plurality of kneading zones from the viewpoint of improving kneading properties and reactivity. Is preferably used. The full flight zone is composed of one or more full flights, and the kneading zone is composed of one or more kneading discs.

Further, among the resin pressures in a plurality of kneading zones, the maximum resin pressure is Pkmax (MPa), and among the resin pressures in a plurality of full flight zones, the minimum resin pressure is Pfmin (MPa). ,
Pkmax≧Pfmin+0.3
It is preferable to melt-knead under the following conditions,
Pkmax≧Pfmin+1.0
More preferably melt-kneading under the following conditions,
Pkmax≧Pfmin+1.5
It is more preferable to melt-knead under the following conditions. The resin pressure in the kneading zone and the full flight zone refers to the resin pressure indicated by the resin pressure gauge installed in each zone.

The kneading zone is excellent in kneading property and reactivity of the molten resin as compared with the full flight zone. By filling the kneading zone with the molten resin, the kneadability and reactivity are dramatically improved. The value of the resin pressure is one index indicating the filled state of the molten resin, and the higher the resin pressure, the more the index shows that the molten resin is filled. That is, in the case of using a twin-screw extruder, the reaction can be effectively promoted by increasing the resin pressure in the kneading zone within a predetermined range from the resin pressure in the full flight zone. It is considered that the reactivity of the amino terminal group and/or the carboxyl terminal group of the resin, the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound and the epoxy group of the (C) epoxy compound is increased, and the heat aging resistance of the molded article, dimensional accuracy, The chemical resistance and creep resistance can be further improved.

The method for increasing the resin pressure in the kneading zone is not particularly limited, for example, between the kneading zone or on the downstream side of the kneading zone, a reverse screw zone having an effect of pushing back the molten resin to the upstream side, or a molten resin. A method of introducing a seal ring zone or the like having an effect of accumulating can be preferably used. The reverse screw zone and the seal ring zone are formed of one or more reverse screws and one or more seal rings, and it is possible to combine them.

When the total length of the kneading zone is Ln, Ln/L is preferably 0.02 or more, more preferably 0.03 or more. On the other hand, Ln/L is preferably 0.40 or less, and more preferably 0.20 or less. By setting Ln/L to 0.02 or more, the reaction of the amino terminal group and/or the carboxyl terminal group of the (A) polyamide resin, the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound and the epoxy group of the (C) epoxy compound The heat resistance of the resin can be appropriately suppressed and the thermal deterioration of the resin can be suppressed. The melting temperature is not particularly limited, but is preferably 340° C. or lower in order to suppress the molecular weight reduction due to the thermal deterioration of the modified polyamide resin.

Next, the polyamide resin composition of the embodiment of the present invention will be described.

The modified polyamide resin of the above-described embodiment of the present invention can further contain a polyamide resin, and the heat aging resistance, chemical resistance and creep resistance of the molded product can be further improved. The reason for this is not clear, but the amide bond of the modified polyamide resin, which is cleaved by deterioration due to heat, chemicals, strain, etc., causes an amide exchange reaction with the amide bond of the polyamide resin that it contains, resulting in modification I think that it may suppress the lowering of the molecular weight of the polyamide resin.

The polyamide resin composition of the embodiment of the present invention may further contain a copper compound in the modified polyamide resin of the embodiment of the present invention. In addition to coordinating with the amide group of the polyamide resin, the copper compound is considered to also coordinate-bond with the hydroxyl group and hydroxide ion of the (B) hydroxyl group-containing aliphatic compound. Therefore, the copper compound enhances the reactivity of the amino terminal groups and/or carboxyl terminal groups of the unreacted (A) polyamide resin contained in the modified polyamide resin with the hydroxyl groups of the unreacted (B) hydroxyl group-containing aliphatic compound. It is considered effective.

The polyamide resin composition according to the embodiment of the present invention may further contain a potassium compound. The potassium compound suppresses liberation and precipitation of copper. Therefore, it is considered that the potassium compound has an effect of increasing the reactivity of the unreacted (A) polyamide resin and the unreacted (B) hydroxyl group-containing aliphatic compound contained in the modified polyamide resin with the copper compound.

Examples of the copper compound include copper chloride, copper bromide, copper iodide, copper acetate, copper acetylacetonate, copper carbonate, copper borofluoride, copper citrate, copper hydroxide, copper nitrate, copper sulfate, and copper oxalate. And so on. You may contain 2 or more types of these as a copper compound. Among these copper compounds, those commercially available are preferable, and copper halide is preferable. Examples of the copper halide include copper iodide, cuprous bromide, cupric bromide, cuprous chloride and the like. Copper iodide is more preferable as the copper halide.

Examples of the potassium compound include potassium iodide, potassium bromide, potassium chloride, potassium fluoride, potassium acetate, potassium hydroxide, potassium carbonate, potassium nitrate and the like. Two or more of these may be contained as the potassium compound. Among these potassium compounds, potassium iodide is preferable. By including the potassium compound, the surface appearance, weather resistance and mold corrosion resistance of the molded product can be improved.

The content (weight basis) of the copper element in the polyamide resin composition of the embodiment of the present invention is preferably 25 to 200 ppm. By setting the content of the copper element to 25 ppm or more, the reactivity of the unreacted (A) polyamide resin and the unreacted (B) hydroxyl group-containing aliphatic compound contained in the modified polyamide resin is increased, and heat aging of the molded product is performed. And the dimensional accuracy, chemical resistance and creep resistance can be further improved. The content (weight basis) of the copper element in the polyamide resin composition is preferably 80 ppm or more. On the other hand, by setting the content of the copper element to be 200 ppm or less, it is possible to suppress the coloring due to the precipitation and liberation of the copper compound, and further improve the surface appearance of the molded product. Further, by setting the content of the copper element to 200 ppm or less, it is possible to suppress the decrease in the hydrogen bonding force of the amide group due to the excessive coordination bond between the polyamide resin and copper, and the heat aging resistance of the molded product, the dimensional accuracy, The chemical resistance and creep resistance can be further improved. The content (weight basis) of the copper element in the polyamide resin composition is preferably 190 ppm or less. The content of the copper element in the polyamide resin composition can be set within the above-mentioned desired range by appropriately adjusting the blending amount of the copper compound.

The content of copper element in the polyamide resin composition can be determined by the following method. First, pellets of the polyamide resin composition are dried under reduced pressure. The pellets are ashed in an electric furnace at 550° C. for 24 hours, concentrated sulfuric acid is added to the ashed material, and the mixture is heated and wet-decomposed to dilute the decomposition liquid. The copper content can be determined by performing atomic absorption analysis (calibration curve method) on the diluted solution.

The ratio Cu/K of the content of the copper element to the content of the potassium element in the polyamide resin composition is preferably 0.21 to 0.43. Cu/K is an index showing the degree of copper deposition and release suppression, and the smaller this value is, the more copper deposition and release is suppressed and the unreacted (A) contained in the copper compound and the modified polyamide resin. ) The reactivity of the polyamide resin and the unreacted (B) hydroxyl group-containing aliphatic compound can be increased. By setting the Cu/K to 0.43 or less, the precipitation and liberation of copper can be suppressed and the surface appearance of the molded product can be further improved. Further, by setting Cu/K to 0.43 or less, the reactivity of the unreacted (A) polyamide resin and the unreacted (B) hydroxyl group-containing aliphatic compound contained in the modified polyamide resin is also improved. Therefore, the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product can be further improved. On the other hand, by setting Cu/K to 0.21 or more, the dispersibility of a compound containing potassium is improved, and even deliquescent potassium iodide is unlikely to form lumps, which has the effect of suppressing the precipitation and release of copper. As a result, the reactivity of the unreacted (A) polyamide resin and the unreacted (B) hydroxyl group-containing aliphatic compound contained in the modified polyamide resin with the copper compound is increased, and the heat aging resistance of the molded article, dimensional accuracy, and Further improves chemical resistance and creep resistance. The potassium element content in the polyamide resin composition can be determined by the same method as the above copper content.

The polyamide resin composition of the embodiment of the present invention may further contain a filler. As the filler, either an organic filler or an inorganic filler may be used, and either a fibrous filler or a non-fibrous filler may be used. A fibrous filler is preferable as the filler.

Examples of the fibrous filler include glass fiber, PAN (polyacrylonitrile)-based or pitch-based carbon fiber, stainless fiber, metal fiber such as aluminum fiber and brass fiber, organic fiber such as aromatic polyamide fiber, gypsum fiber, Ceramic fiber, asbestos fiber, zirconia fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, potassium titanate whiskers, zinc oxide whiskers, calcium carbonate whiskers, wollastonite whiskers, borate aluminum whiskers, silicon nitride whiskers Fibrous or whisker-like fillers such as. As the fibrous filler, glass fiber and carbon fiber are particularly preferable.

The type of glass fiber is not particularly limited as long as it is generally used for reinforcing a resin, and for example, long fiber type or short fiber type chopped strands, milled fiber and the like can be selected and used. Further, the glass fiber may be coated or bundled with a thermoplastic resin such as ethylene/vinyl acetate copolymer or the like, or a thermosetting resin such as an epoxy resin or the like. Furthermore, the cross section of the glass fiber is not limited to a circular shape, a flat gourd shape, an eyebrow shape, an oval shape, an elliptical shape, a rectangular shape, or the like. From the viewpoint of reducing the warp peculiar to the molded product which is likely to occur in the glass fiber-containing polyamide resin composition, a flat fiber having a major axis/minor axis ratio of 1.5 or more is preferable, and 2.0 or more is more preferable. Those of 10 or less are preferable, and those of 6.0 or less are more preferable. If the ratio of major axis/minor axis is less than 1.5, the effect of flattening the cross section is small, and if it exceeds 10, it is difficult to manufacture the glass fiber itself.

As the non-fibrous filler, for example, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, asbestos, alumina silicate, non-swelling silicate such as calcium silicate, Li-type fluorine Swelling layered silicates represented by swelling mica of teniolite, Na-type fluoro-teniolite, Na-type tetrasilicon-fluorine mica, Li-type tetra-silicon-fluorine mica, silicon oxide, magnesium oxide, alumina, silica, diatomaceous earth, zirconium oxide, oxidation Metal oxides such as titanium, iron oxide, zinc oxide, calcium oxide, tin oxide and antimony oxide, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dolomite, hydrotalcite and other metal carbonates, calcium sulfate, barium sulfate Such as metal sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, metal hydroxide such as basic magnesium carbonate, smectite clay mineral such as montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, etc. Examples thereof include various clay minerals such as vermiculite, halloysite, kanemite, kenyaite, zirconium phosphate and titanium phosphate, glass beads, glass flakes, ceramic beads, boron nitride, aluminum nitride, silicon carbide, calcium phosphate, carbon black and graphite. In the swelling layered silicate, the exchangeable cations existing between the layers may be exchanged with an organic onium ion, and examples of the organic onium ion include ammonium ion, phosphonium ion, and sulfonium ion. Moreover, you may contain 2 or more types of these fillers.

The surface of the filler is a known coupling agent (eg, silane coupling agent, titanate coupling agent, etc.) or known sizing agent (eg, carboxylic acid type, epoxy type, urethane type, etc.). And the like, and can further improve the mechanical strength and surface appearance of the molded product. The sizing agent is preferably an epoxy sizing agent. As the method of treating the filler, for example, in the case of treatment with a coupling agent, a method of preliminarily surface treating the filler with a coupling agent according to a conventional method and then melt-kneading with a modified polyamide resin is preferably used. An integrable blending method in which a coupling agent is added may be used when the filler and the modified polyamide resin are melt-kneaded without surface treatment of the material. The treating amount of the coupling agent is preferably 0.05 parts by weight or more, and more preferably 0.5 parts by weight or more with respect to 100 parts by weight of the filler. On the other hand, the treatment amount of the coupling agent is preferably 10 parts by weight or less, and more preferably 3 parts by weight or less with respect to 100 parts by weight of the filler.

In the polyamide resin composition of the embodiment of the present invention, the content of the filler is preferably 1 to 150 parts by weight with respect to 100 parts by weight of the modified polyamide resin. When the content of the filler is 1 part by weight or more, the heat aging resistance, dimensional accuracy, chemical resistance and creep resistance of the molded product can be further improved. The content of the filler is more preferably 10 parts by weight or more, further preferably 20 parts by weight or more. On the other hand, when the content of the filler is 150 parts by weight or less, the float of the filler on the surface of the molded product is suppressed, and a molded product having a better surface appearance can be obtained. The content of the filler is more preferably 80 parts by weight or less, further preferably 70 parts by weight or less.

Furthermore, the polyamide resin composition of the embodiment of the present invention may contain a resin other than the modified polyamide resin and various additives depending on the purpose, as long as the effects of the present invention are not impaired.

Specific examples of the resin other than the modified polyamide resin, polyester resin, polyolefin resin, modified polyphenylene ether resin, polysulfone resin, polyketone resin, polyetherimide resin, polyarylate resin, polyether sulfone resin, polyetherketone resin, poly Examples thereof include thioetherketone resin, polyetheretherketone resin, polyimide resin, polyamideimide resin, and tetrafluoropolyethylene resin. When these resins are blended, the content thereof is preferably 30 parts by weight or less, and more preferably 20 parts by weight or less with respect to 100 parts by weight of the modified polyamide resin in order to fully utilize the characteristics of the modified polyamide resin.

Further, as specific examples of various additives, heat stabilizers other than copper compounds, isocyanate compounds, organic silane compounds, organic titanate compounds, coupling agents such as organic borane compounds, polyalkylene oxide oligomer compounds, Plasticizers such as thioether compounds, ester compounds and organic phosphorus compounds, organic phosphorus compounds, crystal nucleating agents such as polyetheretherketone, wax montanate, lithium stearate, metal soaps such as aluminum stearate, ethylenediamine Stearic acid/sebacic acid polycondensates, release agents such as silicone compounds, anti-coloring agents such as hypophosphite, lubricants, UV inhibitors, colorants, flame retardants, impact modifiers, foaming agents, etc. Can be mentioned. When these additives are contained, the content thereof is preferably 10 parts by weight or less, and more preferably 1 part by weight or less with respect to 100 parts by weight of the modified polyamide resin in order to fully utilize the characteristics of the modified polyamide resin.

Examples of heat stabilizers other than copper compounds include phenol compounds, phosphorus compounds, sulfur compounds and amine compounds. Two or more of these may be used as the heat stabilizer other than the copper compound.

As the phenol compound, hindered phenol compounds are preferably used, and N,N′-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamide), tetrakis[methylene-3-(3 ',5'-Di-t-butyl-4'-hydroxyphenyl)propionate]methane and the like are preferably used.

Examples of the phosphorus compound include bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol-di-phosphite and bis(2,4-di-t-butylphenyl)pentaerythritol-di-phosphite. Fight, bis(2,4-di-cumylphenyl)pentaerythritol-di-phosphite, tris(2,4-di-t-butylphenyl)phosphite, tetrakis(2,4-di-t-butylphenyl)- 4,4'-bisphenylene phosphite, di-stearyl pentaerythritol-di-phosphite, triphenyl phosphite, 3,5-di-butyl-4-hydroxybenzylphosphonate diethyl ester and the like can be mentioned. Among the phosphorus compounds, those having a high melting point are preferably used in order to reduce volatilization and decomposition during the production of the polyamide resin composition.

Examples of the sulfur-based compound include organic thioacid-based compounds, mercaptobenzimidazole-based compounds, dithiocarbamic acid-based compounds, and thiourea-based compounds. Among these sulfur compounds, mercaptobenzimidazole compounds and organic thioacid compounds are preferable. In particular, a thioether compound having a thioether structure receives oxygen from an oxidized substance and reduces it, and thus can be suitably used as a heat stabilizer. Specific examples of the thioether compound include 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate). ) And pentaerythritol tetrakis (3-lauryl thiopropionate) are preferable, and pentaerythritol tetrakis (3-dodecyl thiopropionate) and pentaerythritol tetrakis (3-lauryl thiopropionate) are more preferable. The molecular weight of the sulfur compound is usually 200 or more, preferably 500 or more, and the upper limit thereof is usually 3,000.

As the amine compound, a compound having a diphenylamine skeleton, a compound having a phenylnaphthylamine skeleton and a compound having a dinaphthylamine skeleton are preferable, and a compound having a diphenylamine skeleton and a compound having a phenylnaphthylamine skeleton are more preferable. Among these amine compounds, 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, N,N′-di-2-naphthyl-p-phenylenediamine and N,N′-diphenyl-p-phenylenediamine are available. More preferred are N,N′-di-2-naphthyl-p-phenylenediamine and 4,4′-bis(α,α-dimethylbenzyl)diphenylamine.

As the combination of the sulfur compound or the amine compound, a combination of pentaerythritol tetrakis(3-laurylthiopropionate) and 4,4′-bis(α,α-dimethylbenzyl)diphenylamine is more preferable.

The method for producing the polyamide resin composition of the embodiment of the present invention is not particularly limited, but production in a molten state, production in a solution state, or the like can be used, and from the viewpoint of improving reactivity, production in a molten state. Can be preferably used. As for the production in the molten state, a method of melt-kneading using a twin-screw extruder is preferable as in the method of producing the modified polyamide resin of the embodiment of the present invention. For example, a polyamide resin composition containing the modified polyamide resin of the embodiment of the present invention and a polyamide resin can be produced by melt-kneading the modified polyamide resin and the polyamide resin with a twin-screw extruder. When the copper compound is blended, it is preferable to supply the modified polyamide resin together with the modified polyamide resin to a twin-screw extruder to sufficiently react the modified polyamide resin and the copper compound.

The modified polyamide resin and the polyamide resin composition thus obtained can be molded by a known method, and various molded products such as sheets and films can be obtained. Examples of the molding method include injection molding, injection compression molding, extrusion molding, compression molding, blow molding, and press molding.

The modified polyamide resin, the polyamide resin composition and the molded article thereof according to the embodiment of the present invention make use of their excellent characteristics, and various types such as automobile parts, electric/electronic parts, building members, various containers, daily necessities, household goods and hygiene products. It can be used for various purposes. The modified polyamide resin, the polyamide resin composition and the molded article thereof according to the embodiment of the present invention are, in particular, automobile engine peripherals in which heat aging resistance, surface appearance, retention stability, dimensional accuracy, chemical resistance and creep resistance are required. It is particularly preferably used for parts, automobile underhood parts, car gear parts, car interior parts, car exterior parts, intake/exhaust system parts, engine cooling water system parts, car electrical parts, electric/electronic parts. Specifically, the modified polyamide resin, the polyamide resin composition and the molded article thereof according to the embodiments of the present invention are used for automobiles such as engine covers, air intake pipes, timing belt covers, intake manifolds, filler caps, throttle bodies, and cooling fans. Engine under parts such as engine peripheral parts, cooling fans, radiator tank tops and bases, cylinder head covers, oil pans, brake piping, fuel piping tubes, waste gas system parts, gears, actuators, bearing retainers, bearing cages, chains Automotive gear parts such as guides and chain tensioners, shift lever brackets, steering lock brackets, key cylinders, door inner handles, door handle cowls, interior mirror brackets, air conditioner switches, instrument panels, console boxes, glove boxes, steering wheels, trims Automotive interior parts such as front fenders, rear fenders, fuel lids, door panels, cylinder head covers, door mirror stays, tailgate panels, license garnishes, roof rails, engine mount brackets, rear garnishes, rear spoilers, trunk lids, rocker moldings, moldings, lamps Automotive exterior parts such as housings, front grilles, mudguards, side bumpers, air intake manifolds, intercooler inlets, turbochargers, exhaust pipe covers, inner bushes, bearing retainers, engine mounts, engine head covers, resonators, throttle bodies, etc. Engine cooling water system parts such as parts, chain covers, thermostat housings, outlet pipes, radiator tanks, oil generators, delivery pipes, connectors and wire harness connectors, motor parts, lamp sockets, sensor in-vehicle switches, combination switches and other automotive electrical parts, SMT compatible connectors, sockets, card connectors, jacks, power supply parts, switches, sensors, condenser seats, relays, resistors, fuse holders, coil bobbins, IC and LED compatible housings, reflectors, Si power modules, SiC power modules, etc. It is preferably used for electric/electronic parts.

Hereinafter, embodiments of the present invention will be described more specifically with reference to examples. The characteristic evaluation was performed according to the following methods.

[Melting point of polyamide resin]
About 5 mg of the polyamide resin was collected, and the melting point of the (A) polyamide resin was measured under the following conditions using a robot DSC (differential scanning calorimeter) RDC220 manufactured by Seiko Instruments Inc. under a nitrogen atmosphere. After the polyamide resin is heated to the melting point +40° C. to be in a molten state, the temperature is lowered to 30° C. at a temperature lowering rate of 20° C./min, the temperature is maintained at 30° C. for 3 minutes, and then the melting point is increased at a temperature raising rate of 20° C./min. The temperature (melting point) of the endothermic peak observed when the temperature was raised to +40°C was determined.

[Relative viscosity of polyamide resin]
The relative viscosity (ηr) was measured in a 98% concentrated sulfuric acid solution having a polyamide resin concentration of 0.01 g/ml at 25° C. using an Ostwald viscometer.

[Copper Content and Potassium Content in Polyamide Resin Composition]
The pellet obtained in Example 7 was dried under reduced pressure at 80° C. for 12 hours. The pellets were ashed in an electric furnace at 550° C. for 24 hours, concentrated sulphate was added to the ash, and the mixture was heated for wet decomposition to dilute the decomposition solution. The diluted solution was subjected to atomic absorption analysis (calibration curve method) to determine the copper content and the potassium content. As the atomic absorption spectrometer, AA-6300 manufactured by Shimadzu Corporation was used.

[Reaction Ratio of (A) Carboxyl Terminal Group of Polyamide Resin and (B) Hydroxyl Group of Hydroxyl Group-Containing Aliphatic Compound]
0.05 g of a dry blend of (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound, and 0.05 g of modified polyamide resin are each dissolved in 1.00 ml of bisulfate, and ¹ H- NMR measurement was performed. The analysis conditions are as follows.
Device: JEOL Ltd. nuclear magnetic resonance device (JNM-AL400)
Observation frequency: OBFRQ399.65MHz, OBSET124.00KHz, OBFIN10500.00Hz
Accumulated times: 256 times

From the ¹ H-NMR spectrum of the obtained dry blend, the peak of the proton of the hydrocarbon bonded to the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound was identified, and then from the ¹ H-NMR spectrum of the modified polyamide resin, The peak area of the proton and the peak area of the proton shifted by the reaction were determined. The peak area was calculated by using the analysis software attached to the NMR apparatus and integrating the area of the portion surrounded by the baseline and the peak. The reaction rate was calculated by the following formula (6).
Reaction rate (%)={b/(a+b)}×100 (6)
In the above formula (6), a is the peak area of the proton of the hydrocarbon bonded to the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound that has not reacted with the amino terminal group and/or carboxyl terminal group of the (A) polyamide resin. Represents the peak area of the proton of the hydrocarbon bonded to the hydroxyl group derived from the (B) hydroxyl group-containing aliphatic compound, which is peak-shifted by the reaction.

As an example, FIG. 1 shows the ¹ H-NMR spectrum of the modified polyamide resin obtained in Example 2 described later. From the ¹ H-NMR spectrum shown in FIG. 1, a hydrocarbon that appears in the vicinity of 4.60 ppm and is peak-shifted by the reaction with the carboxyl terminal group of the polyamide resin (A) and is bonded to the hydroxyl group derived from the hydroxyl group-containing aliphatic compound (B). The peak area (a) of the protons of the hydrocarbons bonded to the hydroxyl groups of the unreacted (B) hydroxyl group-containing aliphatic compound appearing at around 4.10 ppm is calculated to obtain the peak area (a) of The reaction rate was calculated from the calculation formula (6).

[Reaction rate of amino terminal group and/or carboxyl terminal group of (A) polyamide resin and epoxy group of (C) epoxy compound]
Fifty grams of freeze-milled modified polyamide resin was extracted with 100 ml of dimethyl sulfoxide at 60° C. for 6 hours, unextracted components were filtered, washed with acetone, and dried to give 0.05 g of modified polyamide resin 0. .05 g of each was dissolved in 1.00 ml of bisulfate and subjected to ¹ H-NMR measurement. The analysis conditions were the same as the ¹ H-NMR analysis conditions in [(A) Reaction rate of carboxyl terminal group of polyamide resin and (B) hydroxyl group of aliphatic compound containing hydroxyl group].

The peak area derived from the (C) epoxy compound was determined from the ¹ H-NMR spectrum of the obtained dry solid, and the peak area derived from the (C) epoxy compound was determined from the ¹ H-NMR spectrum of the modified polyamide resin. The peak area was calculated by using the analysis software attached to the NMR apparatus and integrating the area of the portion surrounded by the baseline and the peak. At this time, the peak area was standardized by the proton peak of the methylene group of the polyamide resin that does not affect the reaction or extraction. The reaction rate was calculated by the following formula (7).
Reaction rate (%)=(b/a)×100 (7)
In the above formula (7), a represents the peak area derived from the (C) epoxy compound in the modified polyamide resin, b represents the modified polyamide resin, and the peak area derived from the (C) epoxy compound in the unextracted component. Represent

As an example, FIG. 1 shows the ¹ H-NMR spectrum of the modified polyamide resin obtained in Example 2 described later. From the ¹ H-NMR spectrum shown in FIG. 1, the peak area of the benzene ring of the (C) epoxy compound appearing at around 8.0 ppm was determined. Next, from the ¹ H-NMR spectrum of the dried product, the peak area derived from the epoxy compound, which appears in the vicinity of 8.0 ppm in the same manner, was obtained, and the reaction rate was calculated from the reaction rate calculation formula (7). Here, the peak area was normalized by the peak of the methylene group adjacent to the carbonyl group of the adipic acid site that appears near 2.25 ppm.

[(B) Presence or absence of reaction between hydroxyl group of hydroxyl group-containing aliphatic compound and epoxy group of (C) epoxy compound]
50 g of the freeze-pulverized modified polyamide resin was extracted with 100 ml of dimethyl sulfoxide at 60° C. for 6 hours to dry the extract. 2.5 g of the dry solid was extracted with 10 ml of chloroform at 30° C. for 6 hours, 0.035 g of the dry solid of the unextracted component was dissolved in 0.70 ml of deuterated dimethyl sulfoxide, and ¹ H-NMR measurement was performed. I went. The analysis conditions were the same as the ¹ H-NMR analysis conditions in [(A) Reaction rate of carboxyl terminal group of polyamide resin and (B) hydroxyl group of aliphatic compound containing hydroxyl group].

The presence of a peak derived from the epoxy compound (C) was confirmed from the obtained ¹ H-NMR spectrum. By the extraction operation with dimethyl sulfoxide, the extract contains the unreacted (B) hydroxyl group-containing aliphatic compound, unreacted (C) epoxy compound, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound. Reactant is present. Further, the extract is subjected to extraction with chloroform to extract the unreacted (C) epoxy compound into a solvent, and the unreacted (B) hydroxyl group-containing aliphatic compound and (B) hydroxyl group-containing aliphatic compound. Since the reaction product of (C) epoxy compound and (C) epoxy compound is not extracted in the solvent, if a peak derived from the epoxy compound can be detected by ¹ H-NMR analysis of the unextracted product, (B) hydroxyl group-containing aliphatic compound and (C) epoxy compound Was determined to be reacting.

As an example, FIG. 2 shows the ¹ H-NMR spectrum of the modified polyamide resin obtained in Example 2 described later, which was measured by the above method. From the ¹ H-NMR spectrum shown in FIG. 2, the peak of the proton of the aromatic ring of the (C) epoxy compound appearing at around 6.8 ppm was detected.

[Increase in carboxyl end group concentration after heat treatment]
The pellets obtained in each Example and Comparative Example were dried under reduced pressure at 80° C. for 12 hours, and the temperature of the cylinder: (A) polyamide resin was measured using an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.). A 3.2 mm thick ASTM No. 1 dumbbell test piece was prepared by injection molding under the conditions of melting point +15° C. and mold temperature: 80° C. (140° C. in Example 13). This dumbbell was heat-treated at 130° C. for 180 hours in the atmosphere. Then, fix the heat-treated test piece to the stage of a milling machine (Type: H-0-1) manufactured by Toyokuni Koki, and use the scaled handle (1 scale: 0.02 mm) to operate the stage in the vertical direction. The modified polyamide resin having a depth of 0.2 mm from the surface of the test piece was cut up and down. About 0.50 g of the cut modified polyamide resin was precisely weighed in a 50 ml Erlenmeyer flask, 20 ml of benzyl alcohol was added, and the mixture was dissolved using an aluminum block heater whose temperature was adjusted to 195°C. A phenolphthalein indicator was added to this solution, and the solution was subjected to neutralization titration with a 0.02 mol/L ethanolic potassium hydroxide solution, and the carboxyl terminal group in the polyamide resin composition was calculated by the following formula (8).
Carboxyl end group concentration [mol/g]=((HI)×f×0.001×0.02)/W (8)
However, H: amount of 0.02 mol/L ethanolic potassium hydroxide solution used for titration [ml], I: amount of 0.02 mol/L ethanolic potassium hydroxide solution used for titration of blank [ml] ], f: factor of 0.02 mol/L ethanolic potassium hydroxide solution, W: mass of sample (excluding glass fiber) [g]

Similarly, the carboxyl end group concentration of the surface layer of the molded product before heat treatment was measured, and the increase amount of the carboxyl end group concentration after heat treatment was calculated by the following formula (9).
Amount of increased carboxyl end group concentration=concentration of end carboxyl group after heat treatment−concentration of end carboxyl group before heat treatment (9).

[Heat aging resistance]
The pellets obtained in each Example and Comparative Example were dried under reduced pressure at 80° C. for 12 hours, and the temperature of the cylinder: (A) polyamide resin was measured using an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.). A 3.2 mm thick ASTM No. 1 dumbbell test piece was prepared by injection molding under the conditions of melting point +15° C. and mold temperature: 80° C. (140° C. in Example 13). This test piece was subjected to a tensile test by a tensile tester Tensilon UTA2.5T (manufactured by Orientec Co., Ltd.) at a crosshead speed of 10 mm/min according to ASTM D638. The measurement was performed 3 times, and the average value was calculated as the tensile strength before the heat aging resistance test treatment. Then, ASTM No. 1 dumbbell test piece was heat-treated (heat aging resistance test treatment) at 135° C. in an atmospheric gear oven for 6000 hours, or 190° C. in an atmospheric gear oven for 3,000 hours, and after the treatment, The same tensile test was performed, and the average value of the three measured values was calculated as the tensile strength after the heat aging resistance test treatment. The ratio (percentage) of the tensile strength after the treatment to the tensile strength before the heat aging resistance treatment was calculated as the tensile strength retention rate. The higher the tensile strength retention rate, the better the heat aging resistance.

[Surface appearance]
The pellets obtained in each Example and Comparative Example were dried under reduced pressure at 80° C. for 12 hours, and the temperature of the cylinder: (A) polyamide resin was measured using an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.). Melting point +15° C., mold temperature: 80° C. (140° C. in Example 13), injection/cooling time=10/10 seconds, screw rotation speed: 150 rpm, injection pressure 100 MPa, injection speed: 100 mm/second, 80 A square plate (film gate) having a thickness of x80x3 mm was injection-molded. The obtained square plate was heat-treated in the atmosphere at 140° C. for 1 hour, the state of the square plate surface after the treatment was visually observed, and evaluated according to the following criteria.
A: The color tone of the molded product is white, and no bleeding is observed on the surface.
B: The color tone of the molded product is slightly bluish white or reddish brown, and no bleeding substance is observed on the surface.
C1: The color tone of the molded product is bluish white or reddish brown, and no bleeding is observed on the surface.
C2: The color tone of the molded product is white, and a bleeding product is recognized on the surface.
In addition, the bleeding material means a material which is raised on the surface of the molded product, and when the (B) hydroxyl group-containing aliphatic compound is solid at room temperature, it is like a dusting cloth, and the (B) hydroxyl group-containing aliphatic compound is When it is liquid at room temperature, it becomes like a viscous liquid.

[Stability]
The pellets obtained in each Example and Comparative Example were dried under reduced pressure at 80° C. for 12 hours, and the relative viscosity after being melt-retained for 30 minutes at the melting point of (A) polyamide resin+20° C. for 30 minutes under a nitrogen atmosphere was measured. A value (percentage) divided by the previous relative viscosity was calculated as a relative viscosity retention rate and used as an index of retention stability. The closer the relative viscosity retention rate is to 100%, the better the retention stability.

[Dimensional accuracy]
The pellets obtained in each Example and Comparative Example were dried under reduced pressure at 80° C. for 12 hours, and the temperature of the cylinder: (A) polyamide resin was measured using an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.). A 80 mm×80 mm×3 mm thick square plate (film gate) was injection molded under the conditions of melting point +15° C., mold temperature: 80° C. (140° C. in Example 13), injection/cooling time=10/10 seconds. After cutting the square plate in the MD direction to a thickness of 10 mm×5 mm×3 mm and annealing at 150° C. for 2 hours, from -40° C. to 150° C. using a thermomechanical analyzer TMA (manufactured by SEIKO) The temperature was raised at 5° C./min, the linear expansion coefficient was calculated according to ISO11359, and used as an index of dimensional accuracy. The smaller the linear expansion coefficient, the better the dimensional accuracy.

[chemical resistance]
The pellets obtained in each Example and Comparative Example were dried under reduced pressure at 80° C. for 12 hours, and the temperature of the cylinder: (A) polyamide resin was measured using an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.). A 3.2 mm thick ASTM No. 1 dumbbell test piece was prepared by injection molding under the conditions of melting point +15° C. and mold temperature: 80° C. (140° C. in Example 13). About this test piece, the tensile strength after heat treatment at 130° C. for 1000 hours in a 50% by volume aqueous solution of genuine super long life coolant (LLC) manufactured by Toyota Co., Ltd., which has an ethylene glycol content of 88% by weight, is the above heat aging resistance. It was measured in the same manner as the sex. The ratio (percentage) of the tensile strength after the treatment to the tensile strength before the treatment was calculated as the tensile strength retention rate and used as a guideline for chemical resistance. The higher the tensile strength retention rate, the better the chemical resistance.

[Creep resistance]
The pellets obtained in each Example and Comparative Example were dried under reduced pressure at 80° C. for 12 hours, and the temperature of the cylinder: (A) polyamide resin was measured using an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.). A 3.2 mm thick ASTM No. 1 dumbbell test piece was prepared by injection molding under the conditions of melting point +15° C. and mold temperature: 80° C. (140° C. in Example 13). According to ASTM D674, this test piece was set in a 6-bar creep tester CP6-L-10kN (manufactured by Orientec), and the amount of strain was measured after processing at 130° C. and a load of 50 MPa for 300 hours. The smaller the amount of strain, the better the creep resistance.

[Hot water resistance]
Pellets obtained in Examples 2 to 3 and 8 to 9 were dried under reduced pressure at 80° C. for 12 hours, and an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.) was used for cylinder temperature: (A). A ASTM No. 1 dumbbell test piece having a thickness of 3.2 mm was produced by injection molding under the conditions of the melting point of the polyamide resin +15° C. and the mold temperature: 80° C. A tensile test was performed on this test piece by a tensile tester Tensilon UTA2.5T (manufactured by Orientec Co.) according to ASTM-D638 at a crosshead speed of 10 mm/min. The measurement was performed three times, and the average value was calculated as the tensile strength before the hot water resistance test treatment. Next, the ASTM No. 1 dumbbell test piece was placed in a pressure-resistant autoclave, ion-exchanged water was added so that the test piece was sufficiently immersed, and the pressure-resistant autoclave was placed in a gear oven at 90° C. for 6 hours to undergo a hot water resistance test treatment. The piece was dried under reduced pressure at 80° C. for 12 hours. A similar tensile test was performed on the dried test piece, and the average value of three measurements was calculated as the tensile strength after the hot water resistance test treatment. The ratio (percentage) of the tensile strength after the hot water resistance test treatment to the tensile strength before the hot water resistance test treatment was calculated as the tensile strength retention rate. The higher the tensile strength retention rate, the better the hot water resistance.

[Moisture and heat resistance]
Pellets obtained in Examples 3 to 5, 9 to 10 and Comparative Examples 8 to 9 were dried under reduced pressure at 80° C. for 12 hours, and an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.) was used. Cylinder temperature: (A) Polyamide resin melting point +15°C, mold temperature: 80°C, injection/cooling time: 10/10 seconds, screw rotation speed: 150 rpm, injection pressure: 100 MPa, injection speed: 100 mm/second A 80 mm×80 mm×3 mm thick square plate (film gate) was injection molded. The obtained square plate was subjected to a wet heat treatment under the conditions of 80° C. and 95% RH for 1 hour, the state of the square plate surface after the treatment was visually observed, and evaluated according to the criteria described in the above [Surface appearance].

Reference example 1 ((A-2) nylon 410)
700 g of 410 salt which is an equimolar salt of tetramethylenediamine and sebacic acid, 21.2 g of 10% by weight tetramethylenediamine aqueous solution (1.00 mol% based on 410 salt), 0.3065 g of sodium hypophosphite (weight of polymer produced) (0.05% by weight) was charged in a polymerization vessel and sealed, and the atmosphere was replaced with nitrogen. After heating was started and the internal pressure of the can reached 0.5 MPa, the internal pressure of the can was kept at 0.5 MPa for 1.5 hours while releasing water out of the system. After that, the pressure in the can was returned to normal pressure over 10 minutes, and the reaction was continued for 1.5 hours under a nitrogen flow to complete the polymerization. Thereafter, the polymer was discharged in a gut form from the polymerization vessel and pelletized, and this was vacuum dried at 80° C. for 24 hours to obtain nylon 410 having ηr=2.84 and a melting point of 252° C.

Reference Example 2 ((A-3) Nylon 10T)
An excess of 10T salt, which is an equimolar salt of decamethylenediamine and terephthalic acid, and 0.5 mol% of decamethylenediamine with respect to the total amount of decamethylenediamine were added. Further, 30 parts by weight of water was added to and mixed with 70 parts by weight of these raw materials in total. This was placed in a pressure vessel, sealed, and purged with nitrogen. After heating was started and the internal pressure of the can reached 2.0 MPa, the internal pressure of the can was 2.0 MPa and the internal temperature of 240° C. was maintained for 2 hours while releasing water out of the system. Then, the content was discharged from the reaction container onto a cooling belt, and this was vacuum dried at 100° C. for 24 hours to obtain a polyamide resin oligomer. The obtained polyamide resin oligomer was pulverized, dried, and solid-phase polymerized at 50 Pa and 240° C. to obtain Nylon 10T having ηr=2.48 and a melting point of 318° C.

Reference Example 3 (nylon 66 masterbatch containing D-1: CuI/KI (weight ratio)=0.23)
2.0 parts by weight of copper iodide and 21.7 parts by weight of 40% potassium iodide aqueous solution were premixed with 100 parts by weight of nylon 66 (“Amilan” (registered trademark) CM3001-N manufactured by Toray Industries, Inc.). Then, using a TEX30 type twin-screw extruder (L/D: 45.5) manufactured by Japan Steel Works, Ltd., the mixture was melt-kneaded under the conditions of a cylinder temperature of 275° C. and a screw rotation speed of 150 rpm, and pelletized by a strand cutter. .. Then, it was vacuum dried at 80° C. for 8 hours to prepare masterbatch pellets having a copper content of 0.60% by weight.

Reference Example 4 (E-1)
7. 15.0 parts by weight of (B-1) dipentaerythritol and 100 parts by weight of nylon 6 ("Amilan" (registered trademark) CM1010 manufactured by Toray Industries, Inc.) and (C-1) bisphenol A type epoxy resin 7. After premixing 5 parts by weight, it is connected to the position of the upstream end of the screw segment using a TEX30 type twin screw extruder (L/D: 45.5) manufactured by Japan Steel Works, Ltd. It was supplied from the main feeder, melted and kneaded under the conditions of a cylinder temperature of 245° C., a screw rotation speed of 200 rpm, Ln/L of 0.28, and Pkmax-Pfmin=1.4, and pelletized by a strand cutter. Then, it was vacuum dried at 80° C. for 8 hours to prepare modified polyamide resin pellets.

Reference Example 5 (E-2)
7. 15.0 parts by weight of (B-1) dipentaerythritol and 100 parts by weight of nylon 6 ("Amilan" CM1010 manufactured by Toray Industries, Inc.), and (C-2) bisphenol A type epoxy resin 7. After premixing 5 parts by weight, it is connected to the position of the upstream end of the screw segment using a TEX30 type twin screw extruder (L/D: 45.5) manufactured by Japan Steel Works, Ltd. It was supplied from the main feeder, melted and kneaded under the conditions of a cylinder temperature of 245° C., a screw rotation speed of 200 rpm, Ln/L of 0.28, and Pkmax-Pfmin=1.4, and pelletized by a strand cutter. Then, it was vacuum dried at 80° C. for 8 hours to prepare modified polyamide resin pellets.

In addition, the polyamide resin, the hydroxyl group-containing compound, the epoxy compound, and the filler used in this example and the comparative example are as follows.
(A-1): Nylon 66 resin having a melting point of 260° C. (“Amilan” (registered trademark) CM3001-N manufactured by Toray Industries, Inc.), ηr=2.78.
(A-4): Nylon 6 resin having a melting point of 225° C. (“Amilan” (registered trademark) CM1010 manufactured by Toray Industries, Inc.), ηr=2.70.
(B-1): Dipentaerythritol (manufactured by Tokyo Chemical Industry Co., Ltd.)
It has 6 hydroxyl groups in one molecule and has a molecular weight of 254 and a hydroxyl value of 1325 mgKOH/g.
(B-2): Diglycerin ("Diglycerin S" manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.)
It has four hydroxyl groups in one molecule and has a molecular weight of 166 and a hydroxyl value of 1325 mgKOH/g.
(B-3): 2,2,4-trimethyl-1,3-pentanediol (manufactured by Tokyo Chemical Industry Co., Ltd.)
It has two hydroxyl groups in one molecule, the molecular weight is 146, and the hydroxyl value is 765 mgKOH/g.
(B-4): 1,3,5-benzenetriol (manufactured by Tokyo Chemical Industry Co., Ltd.)
It has three hydroxyl groups in one molecule. The molecular weight is 126 and the hydroxyl value is 1320 mgKOH/g.
(C-1): Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation)
"JER" (registered trademark) 1004 manufactured by Mitsubishi Chemical Corporation. It has two epoxy groups in one molecule and a molecular weight of 1650. Molecular weight/number of functional groups in one molecule=825.
(C-2): Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation)
"JER" (registered trademark) 1007 manufactured by Mitsubishi Chemical Corporation. It has two epoxy groups in one molecule and has a molecular weight of 2900. Molecular weight/1 number of functional groups in one molecule=1450.
(C-3): Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation)
"JER" (registered trademark) 1010 manufactured by Mitsubishi Chemical Corporation. It has two epoxy groups in one molecule and has a molecular weight of 5,500. Molecular weight/number of functional groups in one molecule=2750. (C-4): Bisphenol A diglycidyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.)
It has two epoxy groups in one molecule and has a molecular weight of 340. Molecular weight/number of functional groups in one molecule=170.
(C-5): Lauryl alcohol (EO)15 glycidyl ether (manufactured by Nagase Chemtex Co., Ltd.)
"Denacol" (registered trademark) EX-171 manufactured by Nagase Chemtex Co., Ltd. It has one epoxy group in one molecule, and has a molecular weight of 970, a molecular weight/the number of functional groups in one molecule=970.
(F-1): Glass fiber with circular cross section (T-275H manufactured by Nippon Electric Glass Co., Ltd.), cross section diameter of 10.5 μm, surface treatment agent: silane coupling agent, sizing agent: carboxylic acid, fiber length 3 mm ..
(F-2): Glass fiber having a circular cross section (T-717H manufactured by Nippon Electric Glass Co., Ltd.), cross section diameter of 10.5 μm, surface treatment agent: silane coupling agent, sizing agent: epoxy, fiber length 3 mm.

(Examples 1-14, Example 16, Comparative Examples 1-3, 5-8)
The polyamide resin, the hydroxyl group-containing compound, the epoxy compound, the copper compound, and the modified polyamide resin shown in the table were set at a cylinder setting temperature of the melting point of the polyamide resin +15°C and a screw rotation speed of 200 rpm. It was supplied to the twin-screw extruder from the main feeder of the twin-screw extruder (L/D=45) and melt-kneaded. This main feeder was connected to the position of 0 when viewed from the upstream side when the total length of the screw was 1.0, that is, the position of the upstream end of the screw segment. Subsequently, the fillers shown in the table were supplied from the side feeder to the twin-screw extruder and melt-kneaded. This side feeder was connected to a position of 0.65 when viewed from the upstream side when the total length of the screw was 1.0, that is, a position downstream of 1/2 of the screw length. The screw configuration of the twin-screw extruder was configured such that Ln/L was 0.28 when the total length of the kneading zone was Ln. Further, of the resin pressures indicated by the resin pressure gauges installed in a plurality of full flight zones, the minimum resin pressure Pfmin and the resin pressure indicated by the resin pressure gauges installed in a plurality of kneading zones The difference from the maximum resin pressure Pkmax (Pkmax-Pfmin) was as shown in the table. The gut discharged from the die was immediately cooled in a water bath and pelletized with a strand cutter. The evaluation results of each Example and Comparative Example are shown in the table. The tensile strength retention rates before and after the hot water resistance test treatment were as follows: Example 2:72%, Example 3:83%, Example 8:84%, Example 9:105%. , Example 3: C2, Example 4: A, Example 5: A, Example 9: C2, Example 10: A, and Comparative Example 8: C2.

(Example 15)
Pellets of the polyamide resin composition were obtained under the same conditions as in Example 2 except that the screw configuration of the twin-screw extruder was changed so that Ln/L was 0.21. The difference between Pfmin and Pkmax (Pkmax-Pfmin) was as shown in the table. The evaluation results are shown in the table.

(Comparative example 4)
Pellets of the polyamide resin composition were obtained under the same conditions as in Example 2 except that the screw configuration of the twin-screw extruder was changed so that Ln/L was 0.02. The difference between Pfmin and Pkmax (Pkmax-Pfmin) was as shown in the table. The evaluation results are shown in the table.

(Comparative Example 9)
Comparison except that the reaction product obtained by pre-mixing the hydroxyl group-containing compound and epoxy compound shown in the table and then charging the mixture in an eggplant-shaped flask and melting at 240° C. for 1.5 hours under a nitrogen atmosphere was used. Under the same conditions as in Example 8, pellets of the polyamide resin composition were obtained. The difference between Pfmin and Pkmax (Pkmax-Pfmin) was as shown in the table. The evaluation results are shown in the table. The evaluation result of the moist heat resistance was C2.

Compared with Comparative Examples 1 to 9, Examples 1 to 16 are modified polyamide resins having a reaction rate of a carboxyl terminal group and a hydroxyl group in a specific range, and thus have excellent retention stability, heat aging resistance, surface appearance, We were able to obtain a molded product with excellent dimensional accuracy, chemical resistance, and creep resistance.

Since Example 7 contains the (D) copper compound, the reactivity between the (A) polyamide resin and the (B) hydroxyl group-containing aliphatic compound is improved as compared with Example 2, and the heat aging resistance and size are improved. It was possible to obtain a molded product with excellent precision, chemical resistance and creep resistance.

Example 8 has the same composition as Example 2, but the modified polyamide resin prepared in Reference Example 4 and the polyamide resin were melt-kneaded, so that heat aging resistance, dimensional accuracy, chemical resistance and creep resistance were obtained. It was possible to obtain a molded product having a better property.

Compared with Comparative Examples 5 to 7, Example 2 used (B) an aliphatic compound having three or more hydroxyl groups and (C) a compound having two or more epoxy groups, and thus (A) a polyamide resin. The reactivity of the carboxyl terminal group of (B) with the hydroxyl group of the (B) hydroxyl group-containing aliphatic compound is improved, and the reactivity of the (B) hydroxyl group-containing aliphatic compound with the epoxy group of the (C) epoxy compound is improved. It was possible to obtain a molded product having excellent heat aging resistance, dimensional accuracy, chemical resistance, surface appearance and creep resistance.

Examples 1 to 9, 12, 13, 15, and 16 are modified polyamide resins having a structure represented by the general formula (1), and Example 14 is a modified polyamide resin having a structure represented by the general formula (2). Compared with Example 11 which is a polyamide resin and does not have the structure represented by the general formula (1) or (2), the resulting molded article has heat aging resistance, dimensional accuracy, chemical resistance and creep resistance. Better.

In Examples 2, 12 and 13, the melting point of the (A) polyamide resin was in a preferable range as compared with Example 14, and thus (A) polyamide resin, (B) hydroxyl group-containing aliphatic compound and (C) epoxy resin. The reactivity of the compound was improved, and a molded product excellent in heat aging resistance, dimensional accuracy, chemical resistance and creep resistance could be obtained.

Compared with Example 15, Example 2 has a reaction rate of a carboxyl terminal group and a hydroxyl group in a preferable range, and thus a molded product having excellent heat aging resistance, dimensional accuracy, chemical resistance and creep resistance can be obtained. did it.

In Example 2, as compared with Example 16, the ratio of the (B) hydroxyl group-containing aliphatic compound to the (C) epoxy compound was in a more preferable range, so that heat aging resistance, dimensional accuracy, chemical resistance and creep resistance were obtained. Thus, a superior molded product could be obtained.

Compared with Example 2, Example 3 contained glass fibers of the epoxy-based sizing agent in Example 9 compared to Example 8, so that a molded article having excellent hot water resistance could be obtained.

Examples 4 and 5 are in comparison with Example 3, and Example 10 is in comparison with Example 9. The molecular weight and the value obtained by dividing the molecular weight by the number of functional groups in one molecule are in preferable ranges. Since the epoxy compound (C) was used, it was possible to obtain a molded product having a better surface appearance during wet heat treatment.

The modified polyamide resin of the embodiment of the present invention can be molded by any method such as injection molding, injection compression molding, compression molding, extrusion molding, blow molding, and press molding, and can be processed into various molded products before use. You can In particular, the modified polyamide resin of the embodiment of the present invention is excellent in retention stability, heat aging resistance, surface appearance, dimensional accuracy, chemical resistance and creep resistance can be obtained by taking advantage of the fact that a molded article can be obtained. Automotive applications such as engine peripheral parts, car under hood parts, car gear parts, car interior parts, car exterior parts, intake/exhaust system parts, engine cooling water system parts, car electrical components, and electrical and electronic parts such as LED reflectors and SMT connectors. It is effective to process it for various purposes.

1 Ester reaction of (B) hydroxyl group-containing aliphatic compound and (A) carboxyl terminal group of polyamide resin 2 Solvent peak

Claims (2)

(A) 1 to 9 parts by weight of an aliphatic compound which does not contain an epoxy group and has 4 or more and 6 or less hydroxyl groups and (C) has 2 epoxy groups with respect to 100 parts by weight of a polyamide resin. A method for producing a modified polyamide resin, comprising reacting a compound having a molecular weight of 1650 to 5500 in an amount of 0.2 to 4.5 parts by weight, wherein (A) polyamide resin, (B) epoxy group- free and 4 or more and 6 or more An aliphatic compound having the following hydroxyl group, and (C) a dry blend of a compound having two epoxy groups and having a molecular weight of 1650 to 5500, which can be obtained by 1H-NMR measurement, (B) does not contain an epoxy group, And a peak area (hereinafter, referred to as peak area A) of a hydrocarbon proton bonded to a hydroxyl group of an aliphatic compound having 4 or more and 6 or less hydroxyl groups, and (B) no epoxy group, and 4 or more 6 Which has no peak-shifted (B) epoxy group due to the reaction of the hydroxyl group of the aliphatic compound having three or less hydroxyl groups with the carboxyl terminal group of the (A) polyamide resin, and which has four or more and six or less hydroxyl groups. The reaction rate (%) represented by the formula {b/(A+b)}×100 is 0.1 to 0.1 from the peak area of hydrocarbons bonded to the hydroxyl group of the group compound (hereinafter referred to as peak area b). 30%, (A) polyamide resin, (B) epoxy group-free aliphatic compound having 4 or more and 6 or less hydroxyl groups, and (C) two epoxy groups having a molecular weight of 1650 to 5500. A method for producing a modified polyamide resin obtained by reacting the compound according to claim 1 . A method for producing a modified polyamide resin which is melt-kneaded using a twin-screw extruder having a plurality of kneading zones and a plurality of full flight zones, wherein the resin having the maximum resin pressure among the kneading zones at a plurality of locations pressure Pkmax (MPa), of the resin pressure in full flight zones at a plurality of locations, the modified polyamide resin according to claim 1, the smallest resin pressure Pfmin a (MPa), and Pfmin + 1.7 ≧ Pkmax ≧ Pfmin + 0.3 Manufacturing method.

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