JPH02113062A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide the subject composition composed of a polyamide, a rubber- reinforced styrene resin and a modified graft copolymer, having excellent impact strength and chemical resistance and giving a molded article having excellent appearance. CONSTITUTION:The objective composition is composed of (A) a polyamide, (B) a rubber-reinforced styrene resin and (C) a modified graft copolymer produced by copolymerizing (C1) 50-99.9wt.% of an aromatic vinyl monomer, (C2) 0.1-30wt.% of a monomer having reactivity or affinity to polyamide and (C3) 0-49.9wt.% of other copolymerizable vinyl monomer in the presence of (C4) a polyolefin. The amounts of the components A, B and C are 90-10 pts.wt., 5-85 pts.wt. and 5-85 pts.wt. based on 100 pts.wt. of A+B+C, respectively. The rubber content in the composition is 5-40wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thermoplastic resin composition having excellent impact resistance, chemical resistance, and molded product appearance.

<Conventional technology> Polyamide resin has excellent moldability, heat resistance, mechanical strength, chemical resistance, abrasion resistance, etc., so it is used for mechanical parts, electrical and
Although it is widely used in electronic parts and automobile parts, it has problems such as a decrease in impact resistance in a dry state and dimensional changes due to moisture absorption. On the other hand, typical rubber-reinforced styrene resins include acrylonitrile-butadiene-styrene copolymer (ABS resin) and AES resins in which the rubber component of ABS resin is replaced with ethylene-propylene rubber or acrylic rubber.
Resins and AAS resins are also widely used in automobile parts, electrical equipment parts, office equipment parts, etc., and although they have excellent impact resistance and dimensional stability, they have the problem of relatively poor chemical resistance.

Polyamide and ABS to improve these problems
It has been proposed to melt and mix resins (Tokuko Sho 8B
-23476) is known to have poor compatibility between polyamide and ABS resin, resulting in molded products exhibiting delamination and resulting in only materials with low impact strength.

In order to improve the compatibility between polyamide and ABS resin, a carboxylic acid having reactivity or affinity with polyamide,
It has been proposed to introduce and modify functional groups such as amide groups into ABS resins (JP-A-54-11159, JP-A-58-82656, JP-A-58-93745, etc.); There are problems in that the appearance of the molded product deteriorates and the impact strength is not sufficiently improved.

<Problems to be Solved by the Invention> As a result of intensive studies by the present inventors on improving the above-mentioned quality problems of compositions made of polyamide resin and rubber-reinforced styrene resin, the present inventors found that The inventors have discovered that a material with excellent impact resistance, chemical resistance, and molded product appearance can be obtained by mixing a resin and a specific modified graft copolymer in a specific ratio, and have thus arrived at the present invention.

Means for Solving the Problems〉 That is, the present invention comprises: (A) polyamide; (B) rubber-reinforced styrenic resin; and (C) polyolefin;
A monomer mixture consisting of 0.1 to 30% by weight of a monomer having reactivity or affinity for polyamide and 0 to 49.9% by weight of another vinyl monomer that can be copolymerized is used. Consisting of a modified graft copolymer obtained by polymerization, (A),
The total amount of (B) and (C) is 100 parts by weight, (
A) 90 to 10 parts by weight, (B) 5 to 85 parts by weight, and (
C) A thermoplastic resin composition with excellent impact resistance, chemical resistance, and molded product appearance, characterized in that the rubber content is 5 to 85 parts by weight and the rubber content in the composition is 5 to 40% by weight. It provides:

Hereinafter, the present invention will be explained in detail.

The polyamide (A) used in the present invention includes ethylene diamine, diaminobutane, hexamethylene diamine, decamethylene diamine, dodecamethylene diamine, 2
．． 2.4- and 2.4.4-trimethylhexamethylene diamine, 1,3 and 1,4-bis(aminomethyl)cyclohexane, bis(P-aminocyclohexyl)
Aliphatic, ring, and aromatic diamines such as methane, metaxylylene diamine, and paraxylylene diamine; Polyamide number ξ derived from aromatic dicarboxylic acid
- Polyamides obtained by ring-opening polymerization of lactams such as caprolactam and ω-dodecalactam, polyamides derived from 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, etc., and copolymerized polyamides and mixed polyamides thereof. Examples include.

Polycaproamide (nylon 6), polydodecaamide (nylon 12), polytetramethylene adipamide (nylon 46), and polyhexamethylene adipamide (nylon 46) are industrially produced at low cost and in large quantities. 6
6) Polyhexamethylene adipamide (nylon 610
), and copolymers thereof, such as nylon 6/
66 ('/'' sign means copolymer) Nylon 6/610, Nylon 6/12, Nylon 66/
12, nylon 6/66/610/12, and mixtures thereof. Also useful are bis(p-7minocyclohexyl)methane/terephthalic acid/isophthalic acid based polyamides.

Note that there is no limit to the degree of polymerization of the polyamide used;
Concentrated sulfuric acid relative viscosity (Polymer 17 was dissolved in 98% concentrated sulfuric acid 100m
/ and measured at 25°C, the same applies hereinafter) is 1.8 to 6.
Any polyamide within the range of 0 can be selected.

There are no restrictions on the molecular structure of polyamide, and either linear polyamide, branched polyamide, etc. may be used. Linear polyamide is produced by conventional methods,
Branched polyamide is polymerized by adding a small amount of a branching agent having eight or more functional groups capable of forming a polyamide, such as bis(ω-aminohexyl)amine, diethylenetriamine, trimesic acid, and bislactam, to the raw material.

Furthermore, in nylon-6, there is no particular restriction on the ratio of terminal amino groups to terminal carboxyl groups, and any ratio can be used.

Polymerization methods include melt polymerization, interfacial polymerization, solution polymerization, bulk polymerization,
Surface phase polymerization and combinations of these methods are used, numerically melt polymerization being the most suitable. Further, particularly when the polyamide raw material is a lactam, the polymer may be obtained by anionic polymerization.

In the present invention, the rubber-reinforced styrenic resin (B) refers to a compound containing 50 to 100 aromatic vinyl monomers in the presence of a rubbery polymer.
A graft copolymer obtained by polymerizing a monomer mixture consisting of 5% by weight and 0 to 50% by weight of another copolymerizable vinyl monomer, or such a graft copolymer and an aromatic vinyl monomer 5
0-100! It is a mixture with a styrene-based polymer consisting of 0 to 50% by weight of other copolymerizable vinyl monomers.

Rubbery polymers used in graft copolymers include:
Diene rubber polymers such as polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, ethylene-propylene copolymer, ethylene-propylene-nonconjugated diene copolymer, acrylic rubber polymer, chlorine Examples include non-diene rubbery polymers such as polyethylene, which can be used alone or in combination.These rubbery polymers can be used in emulsion polymerization, solution polymerization, suspension polymerization, and bulk polymerization. Manufactured by etc.

There are no particular restrictions on the particle size and gel content of the rubbery polymer when produced by emulsion polymerization, but the average particle size is 0.1 to IPm and the gel content is θ to 9.
Preferably it is 5%.

Examples of aromatic vinyl monomers include styrene, α-methylstyrene, 0-methylstyrene, m-methylstyrene, and p-methylstyrene.
Examples include -methylstyrene, t-butylstyrene, α-methylvinyltoluene, dimethylstyrene, chlorostyrene, dichlorostyrene, bromustyrene, dibromostyrene, and the like, which can be used alone or in a mixture of two or more.

Other vinyl monomers copolymerizable with the aromatic vinyl monomer include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, unsaturated carboxylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate,
Maleimide compounds such as maleimide, N-phenylmaleimide, N-methylmaleimide, and N-cyclohexylmaleimide are exemplified and can be used alone or in combination of two or more.

There is no particular restriction on the ratio of the rubbery polymer to the monomer mixture in the graft copolymer, but the rubbery polymer 20 to 8
Preference is given to 0% by weight and 80 to 20% by weight of the monomer mixture.

Further, there is no particular restriction on the grafting rate of the graft copolymer, but it is preferably 20 to 100%.

As the graft polymerization method, known methods such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or a combination thereof are used.

The aromatic vinyl monomer and other copolymerizable vinyl monomers constituting the styrenic polymer used in combination with the graft copolymer are the same as the monomer used in the graft copolymer. Any one kind or two or more kinds can be selected and used from the same group. There is no particular restriction on the molecular weight of the styrene polymer, but the weight average molecular weight is 1
It is preferably 0,000 to 1,000,000. As a polymerization method for the styrenic polymer, known methods such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or a combination thereof are used.

The modified graft copolymer (C) used in the present invention is:
Aromatic vinyl monomer 50-9 in the presence of polyolefin
Monomers consisting of 9.9% by weight, 0.1 to 30% by weight of monomers having reactivity or affinity for polyamide, and 0 to 49.9% by weight of other copolymerizable vinyl monomers. It is a polymer formed by copolymerizing a mixture.

What is the polyolefin that makes up the modified graft copolymer?
Homopolymers such as polyethylene, polypropylene, polybutene, polyisobutylene, poly4-methylpentyne-1, chlorinated polyethylene, and ethylene-vinyl acetate, ethylene-vinyl alcohol, ethylene-vinyl chloride, ethylene-acrylic acid ester, ethylene-vinyl acetate - binary or ternary copolymers such as glycidyl methacrylate.

Further, as the aromatic vinyl monomer, any one or more types can be selected and used from the same group as the aromatic vinyl monomers used for the rubber-reinforced styrenic resin (B).

Examples of monomers that have reactivity or affinity for polyamide include vinyl monomers that have a functional group that reacts with or has an affinity for the terminal carboxylic acid group or amino group of the boria 2D. Examples include vinyl monomers having functional groups such as carboxylic acid groups, acid anhydride groups, amino groups, epoxy groups, and hydroxyl groups, and one type or two or more types can be used.

Examples of the vinyl monomer having a carboxylic acid group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, etc., and one or more types can be used.

Examples of the vinyl monomer having an acid anhydride group include maleic anhydride, citraconic anhydride, chloromaleic anhydride, etc., and one or more types thereof can be used.

Examples of the vinyl monomer having an amino group include acrylamide, methacrylamide, aminoethyl acrylate, dimethylaminoethyl methacrylate, diethylamino methacrylate, etc., and one or more of them can be used. Examples of the vinyl monomer having an epoxy group include glycidyl acrylate, glycidyl methacrylate, etc., and one or more types can be used.

Examples of the vinyl monomer having a hydroxyl group include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate, and one or more of them can be used.

As the other copolymerizable vinyl monomers, one or more of them may be selected from the same group as the other copolymerizable vinyl monomers used in the rubber-reinforced styrenic resin (B). Can be used.

The weight ratios of aromatic vinyl monomers, monomers having reactivity or affinity for polyamide, and other copolymerizable vinyl monomers are 50 to 99.9% by weight and 0.1% by weight, respectively.
-30% by weight and 0-49.9 MM%. Outside this range, the desired composition cannot be obtained.

Preferably, the content is 60 to 90% by weight of aromatic vinyl monomer and 0.0% by weight of monomer having reactivity or affinity for polyamide.
5-20% by weight and 0-35% by weight of copolymerizable monomers.

In addition, there is no particular restriction on the composition ratio of the polyolefin and monomer mixture constituting the modified graft copolymer, but from the physical properties of the final composition, the polyolefin should be 5 to 95 M% and the monomer mixture should be 95 to 5 M%. % by weight is preferred, especially 10-70% by weight of polyolefin, 90-30% by weight of monomer mixture
It is preferable that

As a method for producing the modified graft copolymer, known methods such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or a combination thereof can be employed.

The thermoplastic resin composition of the present invention is made of the above-mentioned polyamide (A
), rubber-reinforced styrenic resin (B) and modified graft copolymer (C), the composition ratio of which is (A), (B).
) and (C) as 100 parts by weight, (A)
90 to 1 parts by weight, (B) 5 to 85 parts by weight, and (
C) 5 to 85 parts by weight, and the rubber content in the composition (ratio of rubber derived from rubber-reinforced styrenic resin to the composition; 5 to 40%).

If the composition ratio of (A), (B) and (C) is outside the above range, the impact resistance, chemical resistance or appearance of the molded product will be poor.

Preferably (A) 80 to 20 parts by weight, (B) 10 to 7 parts by weight
Furthermore, if the rubber content in the composition is less than 5% by weight, the impact strength will be poor, and if it exceeds 40% by weight, the rigidity and hardness will decrease, which is not preferable.

There are no restrictions on the mixing order of the polyamide (A), rubber-reinforced styrene resin (B), and modified graft copolymer (C); the three components may be mixed at once, or the two components may be premixed and then one component may be mixed. can do.

Furthermore, there is no restriction on the mixing method, and known methods such as a Banbury mixer roll or an extruder can be employed.

In addition, when mixing, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, lubricants, dyes, pigments, plasticizers, flame retardants, mold release agents, glass fibers, metal fibers, carbon fibers,
Additives such as metal flakes, reinforcing materials, fillers, etc. can be added. Also, polyacetal, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyphenylene oxide, polymethyl methacrylate,
Thermoplastic resins such as polyvinyl chloride may also be appropriately blended.

Next, the present invention will be specifically explained using Examples and Comparative Examples. Note that all parts and percentages are expressed on a weight basis.

Reference Example 1 Production of rubber-reinforced thermoplastic resin (B) B-1 In the presence of 50 parts (solid content) of polybutadiene latex with an average particle diameter of 0.45P and a gel content of 83%, acrylonitrile was added by an emulsion polymerization method. ABS graft copolymer latex was prepared by copolymerizing 15 parts of styrene and 35 parts of styrene.

B-2 In the presence of 50 parts (solid content) of cross-linked polybutyl acrylate latex with an average particle diameter of 0.3P, 15 parts of acrylonitrile and 35 parts of styrene were copolymerized by emulsion polymerization to obtain an AAS graft copolymer latex. Created.

B-1 iodine number 15.3, Mooney viscosity 67, propylene content 50%, and 75 parts of EPDM containing ethylidene norbornene as the diene component were dissolved in 1000 parts of n-hexane and 650 parts of ethylene dichloride, and 75 parts of styrene was dissolved.
1 part, 25 parts of acrylonitrile, and 3 parts of benzoyl peroxide were added, and the mixture was polymerized at 67° C. for 10 hours under a nitrogen atmosphere to prepare an AES graft copolymer solution.

Graft copolymers B-1 and B-2 were salted out using calcium chloride, separated and dried. Graft copolymer B
-3 was recovered by pouring the polymerization solution into a large excess of methanol, and separating and drying the precipitate.

When the amount of rubber contained in the graft copolymers B-1, B-2, and B-3 was measured by infrared spectroscopy, it was found to be about 50% in each case.

Reference Example 2 Production of Modified Graft Copolymer (C) Granular polypropylene is dispersed in water, styrene, acrylonitrile, and methacrylic acid or glycidyl methacrylate are added and polymerized under a radical polymerization catalyst to produce modified graft copolymer C.
-1 to 4 were created.

Table 1 shows the composition determined by infrared spectroscopy.

Table 1 The rubber-reinforced styrene resin (C) produced in the Reference Example and the modified graft copolymer (C) were mixed into the Example polyamide in the proportions shown in Table 2, and the mixture was heated in a 40-diameter twin-screw extruder. using 25
The mixture was melt-mixed and granulated at 0°C. Nylon 6 (concentrated sulfuric acid relative viscosity 2.6) was used as the polyamide, and intrinsic viscosity (2.6) was used as the acrylonitrile-styrene copolymer (AS).
Beads from the suspension polymerization method of 0.60 (measured in dimethylformamide solution at 30° C.) were used in each case.

The physical properties of the obtained resin composition were measured by the following method,
The results are shown in Table 2.

O impact strength (notched Izot) ASTM D-256 (23° C.) O molded product appearance = 150 votes x 150 blocks x 3.18 blocks were molded and the appearance (presence or absence of Flomark) was visually evaluated. In addition, the presence or absence of delamination was visually determined for the same molded product by a cross-cut test using an adhesive tape.

0 Chemical resistance: A molded product measuring 150 mm x 20 mm x 8 wn was fixed to a cantilever jig, subjected to a deflection of 30 TIrln, and then immersed in various chemicals for 24 hours to determine the presence or absence of cracks.

The above test pieces for quality evaluation were molded using a 3.5-ounce injection molding machine with the cylinder temperature set at 250°C.

<Example 1 and Comparative Example 1> Table 2 shows the effect of blending the modified graft copolymer into the polyamide/ABS composition.

<Examples 2 and 3> Examples using AAS or AES as the rubber-reinforced styrene resin will be shown.

Examples 4 to 5 and Comparative Examples 2 to 3 The effects of the blending ratio of polyamide 4, rubber-reinforced styrene resin 0, and modified graft copolymer (C) and the amount of rubber in the composition on quality will be shown.

<Examples 6 to 7 and Comparative Example 4> The influence of the composition of the modified graft copolymer (C) on the quality will be shown.

<Effects of the Invention> The thermoplastic resin composition of the present invention is a composition that has excellent impact resistance, chemical resistance, and molded product appearance compared to conventional polyamide resin compositions.

Claims (1)

[Scope of Claims] Aromatic vinyl monomer 5 in the presence of (A) polyamide, (B) rubber-reinforced styrenic resin, and (C) polyolefin.
0 to 99.9% by weight, 0.1 to 30% by weight of monomers having reactivity or affinity for polyamide, and 0 to 49.9% by weight of other copolymerizable vinyl monomers. (A) 90 to 10 parts by weight, (B) 5 parts by weight, where the total amount of (A), (B) and (C) is 100 parts by weight. 85 parts by weight and (C) 5 to 85 parts by weight, and the rubber content in the composition is 5 to 40% by weight.