JPH0717791B2 - Resin composition - Google Patents

Description

The present invention relates to a resin composition comprising a polyamide resin and a modified polyolefin having a specific functional group, and having good ejection stability from an extruder.

<Prior Art> In recent years, active studies have been made to improve the impact resistance of polyamide resins and expand their applications. A method usually adopted for this purpose is a method of melt-blending a polyamide resin with various modified polyolefins, and an impact-resistant nylon resin having practical value is actually manufactured and sold. A technically important point in the development of impact-resistant nylon resin is how to modify polyolefin,
The selection of the modifier having the functional group greatly influences the physical properties of the impact-resistant polyamide resin. As the modified polyolefin known so far, as described in JP-B-42-12546 and JP-B-55-44108, a compound having a carboxylic acid group or an acid anhydride group is copolymerized or grafted. Introduced into polyolefin by method, British Patent 1,21
Examples of the copolymers of ethylene and α, β-unsaturated amides disclosed in the specification of 4,781 can be mentioned, and by using a polyolefin modified with a compound having an imide group or an amide group An impact-resistant polyamide resin composition having improved fluidity is disclosed in JP-A-60-35042.

<Problems to be Solved by the Invention> However, when a modified polyolefin having a carboxylic acid group or an acid anhydride group described in JP-B-55-44108 is blended with a polyamide, fluidity during injection molding and molding There is a problem that the surface appearance deteriorates.

When a polyolefin modified with a compound having an amide group or an imide group described in British Patent No. 1,214,781 and JP-A No. 60-35042 is used, injection molding fluidity is surely improved, and a polyamide resin having high impact strength. It was found that a composition could be obtained, but when the amount of imide group or amide group modification decreased, when a melt-kneaded product of polyamide and the modified polyolefin was discharged from the extruder, the spinnability of the discharge gut was poor and unstable. It turned out to be. This phenomenon causes discharge gut wear and leads to deterioration of production operability, and is an important point to be solved in order to produce a product with good quality stability at low cost.

That is, a resin composition comprising a polyamide and a modified polyolefin having high impact resistance, moldability, and excellent manufacturing stability has not yet been obtained, and development of a technique for obtaining a resin composition having these characteristics is desired. It is the current situation.

<Means for Solving Problems> The present inventors have studied a combination of a polyamide and a modified polyolefin which has particularly good stability of a discharge gut from an extruder, high impact strength, and excellent molding fluidity. As a result, a special modified polyolefin in which both a specific amide group and a specific acid anhydride group as the functional group of the modified polyolefin, and a carboxylic acid group were introduced in a very limited amount acted extremely effectively, and the above-mentioned objects were summarized. The inventors have reached the present invention by finding out what can be achieved.

That is, the present invention is (A) polyamide resin 20 to 95 wt%
And (B) a functional group represented by the following formula (I) is 0.005
~ 5 mol% and the following formula (II) and / or (III)
The present invention provides a resin composition comprising 80 to 5% by weight of a modified polyolefin containing 0.005 to 5 mol% of a functional group represented by

(Here, R ₁ and R ₂ are a hydrogen atom or an aliphatic, alicyclic or aromatic residue having 1 to 30 carbon atoms, M is a hydrogen atom or a valence of 1
.About.3 metal ions. The features of the present invention are summarized as follows.

(1) In order to satisfy various requirements such as impact resistance, fluidity during molding, and stability of melt-kneaded product discharge from an extruder all at once, it can be achieved by blending a polyamide with a specific modified polyolefin.

(2) The point of the present technology is to specify the type and amount of the modified functional group of the modified polyolefin.

(3) It is important that the amide group represented by the formula (I) and the acid anhydride group or carboxylic acid group represented by the formula (II) and / or (III) are specified as the modified functional group. Yes, and both of these functional groups are required. The purpose cannot be achieved with either of the functional groups.

(4) The amount of the functional group is effective only within a specific range that is extremely limited. In particular, a modified polyolefin in which the amide group of the above formula (I) is introduced in a larger amount than the acid anhydride group or the carboxylic acid group of the above formulas (II) and (III) can be preferably used.

The (A) polyamide used in the present invention is not particularly limited,
It means all melt-moldable polymers composed of amino acids, lactams or diamines and dicarboxylic acids.
Examples of constituent parts include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and para-aminomethylbenzoic acid, ε-caprolactam,
Lactams such as ω-laurolactam, tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, Meta-xylylenediamine, para-xylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-
Amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane,
Diamines such as bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine and adipic acid, suberic acid,
Azelaic acid, sebacic acid, dodecadioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodiumsulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, It can be selected from dicarboxylic acids such as diglycolic acid. Polyamides particularly useful in the present invention include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66),
Examples include polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecane amide (nylon 11), polydodecane amide (nylon 12), copolyamides thereof, and mixed polyamides. There is no limitation on the degree of polymerization of the polyamide used here, and a polyamide having a relative viscosity within the range of 1.5 to 5.0 can be arbitrarily selected. The method for producing the polyamide is also not particularly limited, and it can be prepared by a conventionally known method such as melt polymerization or solid phase polymerization.

The modified polyolefin (B) used in the present invention is an α-olefin having 2 to 20 carbon atoms or a diene such as ethylene,
Propylene, butene-1, pentene-1, 4-methylpentene-1, isobutylene, 1,4-hexadiene, dicyclopentadiene, 2,5-norbornadiene, 5-ethyl-2,5-norbornadiene, 5-ethylidenenorbornene, 5- (1'-propenyl) -2-norbornene,
A monomer component having an amide group represented by the following formula (I) and an acid anhydride group or a carboxylic acid group represented by the following formulas (II) and (III), containing butadiene, isoprene, and chloroprene as main constituent components And a polymer in which a monomer component having at least one functional group selected from carboxylic acid metal bases is introduced.

Here, R ₁ and R ₂ are hydrogen atoms or aliphatic having 1 to 30 carbon atoms,
Alicyclic and aromatic residues, M is a hydrogen atom or a valence of 1 to 3.
Represents the metal ion of.

Examples of the monomer component having an amide group, an acid anhydride group, a carboxylic acid group, and a carboxylic acid group include acrylamide and N.
-Methyl acrylamide, N-ethyl acrylamide,
N-propyl acrylamide, N-butyl acrylamide, N-octyl acrylamide, N-stearyl acrylamide, N-hydroxymethyl acrylamide, N
-Cyanoethyl acrylamide, N-phenyl acrylamide, N-tolyl acrylamide, N, N-dimethyl acrylamide, N, N-diethyl acrylamide, diacetone acrylamide, N-methyl-N-ethyl acrylamide, methacrylamide, N-methyl methacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, N-butylmethacrylamide,
N-stearylmethacrylamide, N-methylolmethacrylamide, N-hydroxymethylmethacrylamide, N-cyanoethylmethacrylamide, N-phenylmethacrylamide, N-benzylmethacrylamide, N, N-dimethylmethacrylamide, N, N-diethyl Methacrylamide, maleic anhydride, itaconic anhydride, citraconic anhydride, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid,
Methyl maleic acid, methyl fumaric acid, mesaconic acid, citraconic acid, glutaconic acid, methyl hydrogen maleate, methyl hydrogen itaconate, sodium methacrylate, potassium methacrylate, magnesium methacrylate, zinc methacrylate, sodium acrylate, Magnesium acrylate, zinc acrylate, sodium maleate,
Α, β such as magnesium maleate and zinc maleate
-Unsaturated compounds. As a method of introducing the monomer component having these specific functional groups, copolymerize the monomer component with an olefin or a diene, or in the presence of the polyolefin and the monomer component, use a peroxide. It is possible to use a method in which the monomer component is graft-introduced into the polyolefin.

The amount of the functional group-containing component introduced is 0.005 to 5 mol%, preferably 0.01 to 4.5 mol%, more preferably 0.0 to 5 mol% of the unsaturated amide compound based on all the constituent components of the polyolefin.
It is in the range of 2 to 4 mol%. Further, the unsaturated acid anhydride compound and the unsaturated carboxylic acid compound are required to be 0.005 mol to 5 mol% with respect to all the constituent components of the polyolefin, preferably 0.008 to 4 mol%, more preferably 0.01 to 3 mol%. It is a range. If the introduction amount of these functional group-containing components deviates from the above-mentioned limit value, it is not preferable because the ejection stability of the composition from the extruder is deteriorated, and the moldability and mechanical properties are lowered. . In particular, the functional group represented by the formula (I) is effective for improving the compatibility of the polyolefin with the polyamide, and when the introduced amount is less than 0.005 mol%, the gut string of the composition discharged from the extruder is pulled. It is unsuitable because the sex becomes extremely worse. On the other hand, if the amount introduced exceeds 5 mol%, the stability of the polyolefin is lowered and the coloring becomes remarkable, which is not preferable. Further, the functional groups represented by the formulas (II) and (III) are involved in the reaction between the polyolefin and the polyamide, and when the introduced amount is less than 0.005 mol%, the fixation of the polyolefin in the polyamide matrix is sufficient. As a result, the discharge gut from the extruder is easily cut and the production operability deteriorates. On the contrary, if the introduced amount of this functional group exceeds 5 mol%, the reaction with the polyamide becomes too vigorous and side reactions such as gelation are likely to occur, which is not preferable.

Specific examples of the modified polyolefin particularly useful in the present invention include polyethylene-g-acrylamide and a maleic anhydride copolymer (“g” represents a graft, the same applies hereinafter),
Polypropylene-g-acrylamide and maleic anhydride copolymer, poly (4-methylpentene-1) -g-
Acrylamide and maleic anhydride copolymer, poly (ethylene / propylene) -g-acrylamide and maleic anhydride copolymer, poly (ethylene / propylene) -g-methacrylamide and fumaric acid copolymer, poly (ethylene / propylene ) -G-N.butylacrylamide and acrylic acid copolymer, poly (ethylene / butene-1) -g-N.hydroxymethylmethacrylamide and itaconic anhydride copolymer, poly (ethylene / butene-1) -g -N-cyclohexylacrylamide and methacrylic acid copolymer, poly (ethylene / propylene / dicyclopentadiene) -g-acrylamide and maleic anhydride copolymer, poly (ethylene / propylene / 5-ethylidene norbornene) -g-N・
Phenylacrylamide copolymer, poly (ethylene / propylene / norbornadiene) -gN phenylmethacrylamide and zinc methacrylate copolymer, poly (ethylene / acrylamide / maleic anhydride) copolymer, poly (ethylene / acrylic Ethyl acid / N-methylmethacrylamide / maleic anhydride) copolymer, poly (ethylene / propylene / butyl acrylate / maleic anhydride) -g-acrylamide copolymer, poly (ethylene / acrylic acid) -g-N -Butyl acrylamide copolymer, poly (ethylene / methacrylic acid / zinc methacrylate) -g-N, N-diethyl acrylamide copolymer and the like can be mentioned. There is no particular limitation on the degree of polymerization of the modified polyolefin, and the melt index is usually
Anything within the range of 0.05 to 50 g / 10 minutes can be arbitrarily selected. The method for producing the modified polyolefin is also not limited, and a known method can be adopted. Examples of modified polyolefin production methods include a method of radically copolymerizing ethylene, an acrylamide compound, and an unsaturated compound such as maleic anhydride under high pressure, and an ethylene / propylene rubber containing an unsaturated amide compound and an unsaturated carboxylic acid derivative as a peroxide. A method of melt-kneading and graft introduction using The modified polyolefin of the present invention may be mixed with a small amount of a normal polyolefin containing no functional group-containing component.

The resin composition of the present invention comprises (A) a polyamide resin of 20 to 95% by weight, preferably 30 to 93% by weight, more preferably 40 to 90% by weight.
% And (B) modified polyolefin 80 to 5% by weight,
It is preferably composed of 70 to 7% by weight, more preferably 60 to 10% by weight. If the blended composition deviates from the above-mentioned limited range, the respective merits will not be conspicuously exhibited and it is not preferable.

Moldability of the resin composition of the present invention, other components unless impairing the physical properties, for example, pigments, dyes, reinforcing materials,
Fillers, heat-resistant agents, antioxidants, weathering agents, lubricants, crystal nucleating agents, anti-blocking agents, release agents, plasticizers, flame retardants, antistatic agents, other polymers and the like can be added. The method for producing the resin composition of the present invention is not particularly limited, and pellets of polyamide and modified polyolefin, powder, strips, etc. are premixed or not, and are supplied to a uniaxial or multiaxial extruder and melt-kneaded. Is the most common.
It is also possible to modify the polyolefin when melt-kneading the polyamide and the polyolefin.

The resin composition of the present invention includes injection molding, extrusion molding, blow molding,
Molded products with well-balanced mechanical properties can be obtained by subjecting them to molding used for ordinary thermoplastic resins such as compression molding. These molded products are used for various automobile parts, mechanical parts, electric / electronic parts. It is useful as general sundries.

<Examples> The present invention will be described in more detail with reference to Examples.
The properties of the polymers and molded articles described in Examples and Comparative Examples were evaluated by the following methods.

(1) Relative viscosity of polyamide: JIS K6810 (2) Melt index: JIS K7210 (3) Tensile property: ASTM D638 (4) Bending property: ASTM D790 (5) Izod impact strength: ASTM D256 (6) Injection molding fluidity : The spiral flow length was used to judge the flowability.

Example 1 Nylon 6 having a relative viscosity of 2.80 was prepared by melt-polymerizing ε-caprolactam. 80 mol% ethylene and propylene
20% by mol of ethylene / propylene copolymer was added with a small amount of acrylamide and maleic anhydride.
Add with butyl peroxide and use extruder to
By kneading at 0 ° C., a modified polyolefin having a melt index of 1 g / 10 min grafted with 0.8 mol% of acrylamide and 0.5 mol% of maleic anhydride was prepared.

70% by weight of nylon 6 and 30% by weight of poly (ethylene / propylene) -g-acrylamide and maleic anhydride copolymer were weighed and premixed, and then continuously melted at 250 ° C. using an extruder having a diameter of 60 mm. After kneading, the ejection stability was investigated. The spinnability of the discharge gut from the extruder was extremely good, and there was almost no gut break even after continuous operation for a long time.

Further, the composition obtained here was vacuum dried, injection-molded to prepare a test piece, and the physical properties were measured. As shown in Table 1, it was found that the material has high practical value.

Comparative Examples 1 to 4 Physical properties of extruder kneading and injection molding test pieces were carried out in the same manner as in Example 1 except that the amounts of grafted acrylamide and maleic anhydride in the modified polyolefin in Example 1 were changed as shown in Table 1. An evaluation was carried out. It has been found that when the modification of the polyolefin is out of the range specified in the present invention, the ejection stability from the extruder is poor, frequent gut breakage occurs, and the fluidity and mechanical properties during injection molding are poor.

Examples 2 to 19 The same operations as in Example 1 were carried out by changing the types and blending amounts of polyamide and modified polyolefin, and the stability of injection of the composition gut from the extruder, the injection moldability, and the physical properties of the molded test piece. Was evaluated and the results shown in Table 2 were obtained. It was found that in any of the cases shown in Table 2, a material having excellent extrusion runnability, injection molding fluidity and impact resistance was obtained.

Note) a) Polyamide N-6: Polycaproamide, N-66: Polyhexamethylene adipamide, N-610: Polyhexamethylene sebacamide,
N-612: polyhexamethylene dodecamide, N-12: polydodecanamide, N-6 / 66 (85/15): poly (caproamide / hexamethylene adipamide) copolymer (% by weight), N-6 / 66 (10/90): Same as above, N-6 / 12 (80/20):
Poly (caproamide / dodecane amide) copolymer (% by weight), N-6I: polyhexamethylene isophthalamide,
N-MXD6: Polymeta-xylylene adipamide, N-PACM12:
Polybis (4-aminocyclohexyl) methane dodecamide, N-TMDT: polytrimethylhexamethylene terephthalamide, N-12T: polydodecamethylene terephthalamide, N-6I / PACMT (50/50): poly (hexamethylene isophthalamide / Bis (4-aminocyclohexyl) methane terephthalamide) copolymer (wt%).

b) Modified polyolefin [A]: 0.8 mol% of the acrylamide used in Example 1
And a poly (ethylene / propylene): 80/20 (mol%) copolymer grafted with 0.5 mol% of maleic anhydride.

[B]: Poly (ethylene / propylene): 80/20 (mol%) copolymer grafted with 0.5 mol% of N-methylacrylamide and 0.4 mol% of fumaric acid.

[C]: Poly (ethylene / butene-1): 85/15 (mol%) copolymer grafted with 0.6 mol% of methacrylamide and 0.3 mol% of itaconic anhydride.

[D]: Poly (ethylene / propylene / dicyclopentadiene) grafted with 1 mol% of acrylamide and 0.3 mol% of maleic anhydride: 70/20/10 (mol%)
Copolymer.

[E]: Poly (ethylene / propylene / 5-ethylidene norbornene): 70/25/5 (mol%) copolymer grafted with 1 mol% of methacrylamide and 0.4 mol% of maleic acid.

[F]: Polypropylene grafted with 0.8 mol% of acrylic amid and 0.4 mol% of maleic anhydride.

[G]: Polyethylene grafted with 0.8 mol% of acrylamide and 0.4 mol% of maleic anhydride.

[H]: Poly (4-methylpentene-1) grafted with 0.8 mol% of acrylamide and 0.4 mol% of maleic anhydride.

[I]: Poly (ethylene / acrylamide / maleic anhydride): 96/3/1 (mol%) copolymer.

[J]: Poly (ethylene / propylene / isobutyl acrylate / maleic anhydride) grafted with 1 mol% of methacrylamide: 80/10/9/1 (mol%) copolymer.

Example 20 Nylon 6 and polypropylene obtained in Example 15-g-
Mixture of acrylamide and maleic anhydride copolymer
After adding 45 parts by weight of chopped strand glass fiber to 100 parts by weight, the mixture was melted and kneaded by an extruder to be pelletized. The pellets obtained here were fed to an injection molding machine to mold a test piece, and then the physical properties were measured. The results shown in Table 3 were obtained.

<Effects of the Invention> The feature of the present invention is that the type and amount of functional groups of the modified polyolefin are limited, and the resin composition comprising the polyamide and the specific modified polyolefin obtained in the present invention is extruded at the time of melt kneading preparation. It has good ejection stability and excellent mechanical properties such as injection molding fluidity and impact resistance. Therefore, a resin composition having good production operability and quality stability can be obtained here.

Claims (1)

[Claims] 1. A polyamide resin of 20 to 95% by weight and (B) a functional group of the following formula (I) of 0.005 to 5 mol% and the following formula (II) and / or (III). A resin composition comprising 80 to 5% by weight of a modified polyolefin containing 0.005 to 5 mol% of a functional group. (Here, R ₁ and R ₂ are a hydrogen atom or an aliphatic, alicyclic or aromatic residue having 1 to 30 carbon atoms, M is a hydrogen atom or a valence of 1
.About.3 metal ions. )