JPH0621222B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a resin composition comprising polyalkylene terephthalate, an aliphatic polyamide and a modified polyolefin having a specific functional group, which has excellent moldability, physical properties and heat resistance. Is.

<Prior Art> Polyethylene terephthalate has excellent mechanical properties, chemical properties and electrical properties, and is widely used as fibers and films. However, as is well known, polyethylene terephthalate is not always particularly suitable as an injection molding material due to its poor moldability and brittleness due to its slow crystallization rate at temperatures below 100 ° C. ing. A number of proposals have been made in the past for improving these drawbacks and widely using polyethylene terephthalate in the molding field.

That is, accelerating crystallization is a method of adding a crystal nucleating agent to polyethylene terephthalate, and representative examples thereof include inorganic fine particles such as talc (Japanese Patent Publication No. 4754-5742), alkali metal salt compounds of organic carboxylic acids (Japanese Patent Publication No.
48-4097), a combination of sodium organic carboxylate and a low molecular weight plasticizer compound (JP-A-54-158452), and the like are known. Further, as a method for improving the brittleness and imparting toughness of polyethylene terephthalate, there has been proposed a method of blending a polyamide and an epoxy group-containing olefin copolymer (JP-A-55-92759).

<Problems to be Solved by the Invention> The present inventors also intend to increase the crystallization rate of polyethylene terephthalate, improve injection moldability, and at the same time improve toughness, polyethylene terephthalate, polyamide and modified polyolefin When the combination was examined, when the epoxy group-containing modified polyolefin shown in the preceding example was used, a remarkable improvement in toughness was certainly observed, but the reactivity of the epoxy group with polyamide and polyester was too large to increase. One of the problems is that the viscosity is remarkably deteriorated at the time of molding and the fluidity at the time of molding is deteriorated. Further, the second problem is that the composition comprising polyethylene terephthalate, polyamide and epoxy group-containing modified polyolefin has an unsatisfactory heat distortion temperature. It turned out to be a problem. That is, the polyethylene terephthalate-based material, which has a truly high practical value, not only has improved toughness, but must also have excellent fluidity during molding and heat resistance represented by heat distortion temperature.

<Means and Actions for Solving Problems> Then, the inventors of the present invention have studied a method for improving moldability, toughness, fluidity and heat resistance of polyethylene terephthalate. It has been found that many objects can be achieved extremely effectively all at once by incorporating a modified polyolefin having a specific functional group in a form in which an amine is added to the group. Furthermore, the method of blending a specific amount of this aliphatic polyamide and a specific modified polyolefin is extremely effective in improving not only polyethylene terephthalate but also polyalkylene terephthalate general fluidity, toughness, etc. From the viewpoint, the inventors have found that the blending of the thermoplastic polyester and the modified polyolefin can suppress the dimensional change due to moisture absorption, and the resin composition with improved fluidity at the time of molding and having an extremely good balance of physical properties can be obtained, and arrived at the present invention.

That is, the present invention relates to thermoplastic polyesters 35 to 9 containing (A) alkylene terephthalate units as main constituent units.
8% by weight, (B) 1 to 60% by weight of aliphatic polyamide, and
(C) a functional group represented by the following formula (I) or (II) from 0.001 to
The present invention provides a resin composition comprising 1 to 30% by weight of a modified ethylene copolymer containing 10 mol%.

Here, R _{1 to} R ₄ represent a hydrogen atom, an aliphatic group having 1 to 30 carbon atoms, an alicyclic group or an aromatic group.

The polyester containing (A) alkylene terephthalate unit as a main constituent unit used in the present invention has 2 to 6 carbon atoms.
A diol component having an alkylene moiety such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, and terephthalic acid or its ester-forming derivative. Polyester homopolymers composed of units obtained by the condensation reaction of, and copolymers and mixtures containing 80 mol% or more of the units. Examples of the diol component as the copolymerization component include 2-ethylhexane-1,3-diol, cyclohexanediol, cyclohexanedimethanol, 2,2-bis (4-hydroxyphenyl) propane, and a molecular weight of 400 to 6,0.
00 long-chain glycol, that is, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and mixtures thereof, and examples of the dicarboxylic acid component as a copolymerization component include isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, Bisbenzoic acid, bis (p-carboxyphenyl) methane,
4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, adipic acid, sebacic acid, azelaic acid, dodecanoic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid or these Examples thereof include ester-forming derivatives and the like, either alone or as a mixture. It is also possible to use an oxy acid such as p-oxybenzoic acid or p-hydroxymethylbenzoic acid as a copolymerization component, and further a small amount of a polyfunctional component may be copolymerized. Particularly useful polyesters in the present invention are polyethylene terephthalate and polybutylene terephthalate. Regarding the degree of polymerization of the polyester used here, a phenol / tetrachloroethane mixed solvent (6 /
It is preferable that the intrinsic viscosity measured at 30 ° C. according to (4 weight ratio) is 0.4 or more.

The (B) aliphatic polyamide used in the present invention is a polyamide containing an aliphatic amino acid, a lactam or a diamine, and a dicarboxylic acid as main components. Typical examples of its main constituents include 6-aminocaproic acid, 11
-Aminoundecanoic acid, amino acids such as 12-aminododecanoic acid, ε-caprolactam, lactams such as ω-laurolactam, tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / Diamines such as 2,4,4-trimethylhexamethylenediamine and 5-methylnonamethylenediamine, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, dicarboxylic acids such as diglycolic acid, and the like. In addition to the aliphatic components, a small amount of aromatic components and alicyclic components such as para-aminomethylbenzoic acid, metaxylylenediamine, para-xylylenediamine, 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, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid,
2-methylterephthalic acid, 5-methylisophthalic acid, 5
It is also possible to use a copolyamide or a mixed polyamide in which sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, etc. are introduced. Particularly useful polyamides in the present invention are polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 6).
6), polyhexamethylene sebacamide (nylon 61
0), polyhexamethylene dodecamide (nylon 612),
Examples include polyundecamethylene adipamide (nylon 116), polyundecane amide (nylon 11), and polydodecanamide (nylon 12). There is no limitation on the degree of polymerization of the polyamide used here, and a 1% concentrated sulfuric acid solution is added to
A polyamide having a relative viscosity measured at 5 ° C within the range of 2.0 to 5.0 can be arbitrarily selected.

The (C) modified ethylene copolymer used in the present invention is propylene as necessary with ethylene as a main constituent component,
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, butadiene, isoprene, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, dimethyl maleate, vinyl acetate, acrylamide, etc. A polyolefin having a functional group represented by the following formula (I) or (II) in the side chain or main chain as a polymerization component.

Here, R _{1 to} R ₄ represent a hydrogen atom, an aliphatic group having 1 to 30 carbon atoms, an alicyclic group, or an aromatic group.

The above-mentioned functional group can be created by adding ammonia or a primary or secondary aliphatic amine, alicyclic amine or aromatic amine to the epoxy group. The method of introducing the above-mentioned functional group into the side chain or main chain of polyolefin is to add ammonia or amines to an epoxy group-containing α, β-unsaturated compound to prepare an N-substituted hydroxyethyl compound, which is then added to ethylene or the like. It is possible to copolymerize with the above-mentioned monomer or to graft-introduce it to the polyolefin by using a radical initiator. The modified ethylene-based copolymer of the present invention can also be obtained by preparing a polyolefin having an epoxy group in advance and adding ammonia or amines thereto. Examples of the epoxy group-containing α, β-unsaturated compound include glycidyl acrylate, glycidyl methacrylate, vinyl glycidyl ether,
Examples of amine compounds such as allyl glycidyl ether which form a functional group represented by the formula (I) or (II) by addition to these epoxy groups are ammonia, methylamine, ethylamine, butylamine and hexyl. Amine, dodecylamine, oleylamine, stearylamine, aniline, naphthylamine, dimethylamine, diethylamine, methylethylamine, dibutylamine, distearylamine, cyclohexylamine, dicyclohexylamine, benzylamine, ethylcyclohexylamine, methylaniline, phenylnaphthylamine, melamine, Ethanolamine, 3-amino-1-
Propanol, diethanolamine, morpholine, α-
Amino-1-pyrrolidone, α-amino-ε-caprolactam, α-monomethylamino-ε-caprolactam, α
-Monobenzyl-ε-caprolactam and the like. The introduced amount of the functional group represented by the formula (I) or (II) is 0.001 to 10 with respect to the total constituents of the modified ethylene copolymer.
It should be in the range of mol%, preferably 0.01 to 8 mol%. When the amount of the functional group is less than 0.001 mol%, the compatibility with polyester and polyamide is insufficient and the effect of improving impact resistance is small, which is not preferable. On the other hand, when the amount of the functional group exceeds 10 mol%, the stability of the ethylene-based copolymer is high. Is lowered, and side reactions such as gelation are likely to occur, which is not suitable. The molecular weight of the modified ethylene copolymer of the present invention is not particularly limited, and usually the melt index is
0.01 to 100 g / 10 minutes, preferably 0.02 to 80 g / 1
Those within the range of 0 minutes can be arbitrarily selected. In the present invention, it is also possible to mix a small amount of a normal polyolefin that does not contain a functional group. In the present invention, it is preferable to use an ethylene-based copolymer for the purpose of improving impact resistance of a thermoplastic polyester such as polyethylene terephthalate, and modified polypropylene and the like are naturally excluded.

Specific examples of the modified ethylene copolymer particularly useful in the present invention include a copolymer obtained by adding amines to poly (ethylene / propylene) -g-glycidyl methacrylate (“g” represents a graft, The same shall apply hereinafter), a copolymer obtained by adding amines to poly (ethylene / butene-1) -g-glycidyl methacrylate, poly (ethylene / propylene / dicyclopentadiene) -g-glycidyl methacrylate with amines. , A copolymer obtained by adding amines to poly (ethylene / vinyl acetate) -g-glycidyl methacrylate, a copolymer obtained by adding amines to poly (ethylene / glycidyl methacrylate), Examples thereof include polymers and copolymers obtained by adding amines to poly (ethylene / glycidyl acrylate).

The resin composition of the present invention is (A) thermoplastic polyester 35-
98% by weight, more preferably 40-95% by weight, (B) aliphatic polyamide 1-60% by weight, more preferably 3-5
5% by weight and (C) modified ethylene-based copolymer 1 to 30% by weight, more preferably 2 to 28% by weight. If the compounding ratio of each component is out of the above range, desired effects cannot be obtained in many points such as moldability and physical properties.

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, release agents, plasticizers, flame retardants, antistatic agents, and other polymers can be added and introduced. In particular, it is important to add reinforcing materials and fillers, and fibrous or powdery reinforcement such as glass fiber, asbestos fiber, carbon fiber, graphite fiber, wollastonite, talc, calcium carbonate, mica, clay, potash whiskers and glass beads. A material can be added and compounded, and it is preferable to use a fibrous reinforcing material such as glass fiber or carbon fiber.

The method for producing the resin composition of the present invention is not particularly limited, and polyalkylene terephthalate, an aliphatic group polyamide and a modified ethylene-based copolymer may be uniaxially or simultaneously preliminarily mixed with three components or two components respectively. The most common method is to feed the mixture into a multi-screw extruder and melt-knead. The resin composition of the present invention can be used for molding used for ordinary thermoplastic resins such as injection molding, extrusion molding, blow molding, and compression molding to obtain a molded article having excellent physical properties.
These molded products are useful as various automobile parts, machine parts, electric / electronic parts, general sundries and the like.

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

(1) Intrinsic viscosity of polyester: The polymer was dissolved in a phenol / tetrachloroethane mixed solvent (6/4 weight ratio) and measured at 30 ° C.

(2) Relative viscosity of polyamide: JIS K6810 (3) Melt index: JIS K7210 (4) Tensile property: ASTM D638 (5) Bending property: ASTM D790 (6) Izod impact strength: ATSM D256 (7) Thermal deformation temperature: ASTM D648 (8) Dimensional stability: Tensile specimens after molding in oven
The dimensional change rate when heat-treated at 15 ° C. for 15 hours was obtained.

(9) Flowability: The flow length at the time of injection molding using a spiral mold, the so-called spiral flow length (thickness 3 mm) was measured.

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.58 was prepared from ethylene glycol and terephthalic acid by melt polymerization. ε-caprolactam was melt-polymerized to prepare nylon 6 having a relative viscosity of 2.90. Ethylene / vinyl acetate-g by graft-copolymerizing glycidyl methacrylate with an ethylene / vinyl acetate copolymer in the presence of a dicumyl peroxide catalyst
A glycidyl methacrylate copolymer (ethylene content 62%, epoxy equivalent about 3,000) was obtained. After adding and mixing α-amino-ε-caprolactam to the ethylene / vinyl acetate-g-glycidyl methacrylate copolymer,
A copolymer obtained by kneading at 180 ° C. using an extruder and adding α-amino-ε-caprolactam to ethylene / vinyl acetate-g-glycidyl methacrylate having the following functional groups of 3.0 mol% (melt index 5 g / 10 minutes) was prepared.

Polyethylene terephthalate: 60% by weight, nylon 6: 20% by weight, and a copolymer of ethylene / vinyl acetate-g-glycidyl methacrylic acid and α-amino-ε-caprolactam added thereto: 20% by weight, and Using an extruder having a diameter of 65 mm, the mixture was melt-kneaded at 270 ° C. and pelletized. After drying these pellets, injection molding machine was used to mold various physical property test specimens under the conditions of cylinder temperature of 270 ° C, mold temperature of 80 ° C and injection pressure of 700 kg / cm ² , and evaluate the moldability and obtain them here. When the characteristics of the obtained test piece were evaluated, as shown below, it was found to be a polyethylene terephthalate-based material that has good fluidity during molding and is sufficiently crystallized and has high practical value.

Fluidity (spiral flow length): 58 cm Tensile strength: 660 kg / cm ² Bending strength: 1,010 kg / cm ² Bending elastic modulus: 26,600 kg / cm ² Izod impact strength: 20 kg ・ cm / cm Notch heat deformation temperature (4.6 kg / cm ² : 205 ° C. Dimensional change during heat treatment: 0.40% Comparative Example 1 The polyethylene terephthalate used in Example 1 was injection-molded in exactly the same manner as in Example 1 to obtain a test piece. It was found that the dimensional stability of the test piece was poor and crystallization did not proceed sufficiently during molding.

Dimensional change during heat treatment: 1.40% Comparative Example 2 Carried out using the ethylene / vinyl acetate-g-glycidyl methacrylate copolymer obtained in the intermediate step in Example 1 (ethylene content 62%, epoxy equivalent 3,000). Example 1
Melt kneading and injection molding were carried out in the same manner as in Example 1, but the fluidity was poor, and the heat distortion temperature of the obtained test piece was unsatisfactory.

Flowability (spiral flow length): 30 cm Heat distortion temperature (4.6 kg / cm ² ): 162 ° C. Example 2 Polybutylene terephthalate having an intrinsic viscosity of 1.20 was prepared from 1,4-butanediol and terephthalic acid by melt polymerization. Nylon 66 having a relative viscosity of 3.00 was prepared by melt polymerization of hexamethylenediamine and a substantially equimolar salt of adipic acid. Cyclohexylamine was added to an ethylene / glycidyl methacrylate: 96/4 (mol%) copolymer by a melt-kneading method to prepare a copolymer having the following functional groups (melt index 8 g / 10 min).

Polybutylene terephthalate: 40% by weight, nylon 6
After premixing 6: 40% by weight and a copolymer of cyclohexylamine added to poly (ethylene / glycidyl methacrylate): 20% by weight, melt kneading and injection molding were carried out in the same manner as in Example 1. When the characteristics of the test piece obtained as described above were evaluated, it was found that the material had a high practical value as shown below.

Flowability (spiral flow length): 80 cm Tensile strength: 670 kg / cm ² Bending strength: 920 kg / cm ² Bending elastic modulus: 24,000 kg / cm ² Izod impact strength: 35 kg ・ cm / cm Notch heat distortion temperature (4.6 kg / cm ² ): 188 ° C. Dimensional change due to moisture absorption: 0.17% Dimensional change during heat treatment: 0.24% Comparative Example 3 Nylon 66 used in Example 2 had a large dimensional change due to moisture absorption and was poor in dimensional stability.

Dimensional change due to moisture absorption: 0.53% Example 3 Polyethylene terephthalate obtained in Example 1: 60% by weight, Nylon 6: 20% by weight and ethylene / vinyl acetate-g-glycidyl methacrylate α-amino-ε-
Copolymer to which caprolactam is added: 45 parts by weight of chopped strand glass fibers are added to 100 parts by weight of a mixture of 20% by weight and premixed, and then 65 mmφ
It was melt-kneaded and pelletized at 280 ° C. using an extruder having a diameter. After drying these pellets, cylinder temperature 275 ℃, mold temperature 90 ℃, injection pressure 900kg / cm ² by injection molding machine.
When the test pieces for measuring various physical properties were molded under the conditions described in 1 above, the moldability was evaluated, and the characteristics of the test pieces obtained here were evaluated. As a result, it was found that the test pieces exhibited excellent characteristics.

Fluidity (spiral flow length): 42 cm Tensile strength: 1,300 kg / cm ² Bending strength: 1,900 kg / cm ² Bending elastic modulus: 95,000 kg / cm ² Izod impact strength: 9 kg ・ cm / cm Notch heat deformation temperature (18.6 kg / cm < ² >): 225 [deg.] C. Dimensional change during heat treatment: 0.04% Examples 4 to 10 Examples 1 to 3 were performed by changing the types and blending amounts of thermoplastic polyester, aliphatic polyamide and modified polyolefin.
The physical properties of the test piece obtained by performing the same operation as above were measured, and the results shown in Table 1 were obtained.

<Effects of the Invention> The resin composition of the present invention can exhibit the following characteristics extremely effectively by combining at least three specific polymers.

(1) The aliphatic polyamide acts as a crystallization accelerator of polyethylene terephthalate, and a molded product with good dimensional stability that is sufficiently crystallized even in injection molding using a mold of less than 100 ° C. can be obtained.

(2) Conventionally known modified polyolefin having an epoxy group has large reactivity with polyester and polyamide and deteriorates fluidity at the time of molding, but the functional group of the modified polyolefin used in the present invention has an epoxy group with an amine. The composition which has been added is obtained, and by suppressing the reactivity with respect to polyester and polyamide, a composition having remarkably improved fluidity in injection molding can be obtained.

(3) The modified polyolefin is an ethylene-based copolymer having the above-mentioned specific functional group, and can effectively improve the impact strength of thermoplastic polyester such as polyethylene terephthalate. Surprisingly, the resin composition comprising the modified polyolefin, aliphatic polyamide and thermoplastic polyester specified in the present invention has a remarkably high heat distortion temperature and is effective in improving heat resistance.

(4) As described above, the resin composition of the present invention has strength, rigidity,
It was found that various physical properties such as impact resistance, heat resistance, and dimensional stability are well balanced.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area C08L 23:08)

Claims (1)

[Claims] 1. A thermoplastic polymer having (A) an alkylene terephthalate unit as a main constituent unit in an amount of 35 to 98% by weight, (B) an aliphatic polyamide in an amount of 1 to 60% by weight, and (C) the following formula (I) or (II). A resin composition comprising 1 to 30% by weight of an ethylene-based copolymer containing 0.001 to 10 mol% of a functional group represented by. Here, R _{1 to} R ₄ represent a hydrogen atom, an aliphatic group having 1 to 30 carbon atoms, an alicyclic group or an aromatic group.