JPH07116358B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a thermoplastic resin composition having excellent heat resistance, impact resistance and appearance of a molded article.

b. Conventional Technology Polyamide resin composed of tetramethylenediamine, adipic acid and their functional derivatives is known as nylon 4,6 resin. This nylon 4,6 resin is excellent in mechanical strength such as tensile strength and bending strength, heat resistance,
Because of its excellent sliding properties, it is of great value as a useful engineering plastic.

c. Problems to be Solved by the Invention However, nylon 4 and 6 resins have a drawback of poor impact resistance. The present inventors have added various elastomer components and various rubbery polymers to nylon 4,6 resin,
Attempts were made to improve the impact resistance, but there were many variations in the impact resistance, and there were problems such as a peeling phenomenon, which made it unusable for practical use.

Therefore, the present inventors have conducted intensive studies on a thermoplastic resin composition having excellent heat resistance and impact resistance, and found that nylon 4,
It has been found that the above object can be achieved by a thermoplastic resin composition comprising 6 resins and an elastomer component modified with a specific functional group, and the present invention has been accomplished based on such findings.

When an elastomer component modified with a specific functional group is blended with a nylon other than nylon 4,6 resin, such as nylon 6, nylon 6,6, nylon 12, etc., the impact resistance is improved, but a molded product is obtained. The result was that the sink marks were large and the appearance of the molded product was inferior.

d. Means for Solving the Problems That is, the present invention includes (a) nylon 4,6 resin 1 to 99% by weight (b) at least an epoxy group, an acid anhydride group, a carboxyl group, and an amino group. A rubbery polymer modified with one type of functional group (however, excluding an ethylene copolymer graft-polymerized with an unsaturated dicarboxylic acid or a derivative thereof, and an ionomer resin), the functional group The present invention relates to a thermoplastic resin composition comprising 99-1% by weight of a rubbery polymer having an amount of 5 × 10 ² to 1 × 10 ⁶ g / eq iv.

The component (a) nylon 4,6 resin used in the present invention is a polyamide obtained by a condensation reaction using adipic acid or its functional derivative as the acid component and tetramethylenediamine or its functional derivative as the amine component. Although the main component is used, a part of the adipic acid component or the tetramethylenediamine component may be replaced with another copolymerization component.

Preferred methods for producing the nylon 4,6 resin include the methods described in JP-A-56-149430 and JP-A-56-149431.

The molecular weight of the preferred nylon 4,6 resin used in the present invention is 1.5 or more in relative viscosity (η _reL : measurement temperature 30 ° C., 97% sulfuric acid is used and measured at a concentration of 1 g / 100 ml), and more preferably _{2.5 to 5.0.} It is in the range of.

The amount of the nylon 4,6 resin which is the component (a) of the present invention is 1 to 99% by weight, preferably 10 to 98% by weight, more preferably 50 to 95% by weight, particularly preferably 60 to 95% by weight. is there. If the amount used is less than 1% by weight, the effect of improving heat resistance is poor, and if it is 99% by weight or more, the impact resistance is poor.

The rubbery polymer as the component (b) used in the present invention is a rubber-like polymer, a thermoplastic elastomer, and a rubber-like polymer or a thermoplastic elastomer with a monomer containing a styrene-based monomer as a main component. The polymerized graft copolymer is modified with an epoxy group, an acid anhydride group, a carboxyl group or an amino group.

The above-mentioned graft copolymer is a latex rubber-like polymer, a polymer obtained by emulsion-grafting a styrene-based monomer on a thermoplastic elastomer, or a rubber-like polymer, or a styrene-based monomer of a thermoplastic elastomer. A polymer obtained by dissolving a body in a solvent containing the main component and polymerizing the solution by a method such as bulk polymerization, solution polymerization, or suspension polymerization.

As the rubber-like polymer used here, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, diene rubber such as polyisoprene, ethylene-propylene copolymer, ethylene-propylene-polyene copolymer. Examples include olefin rubber such as, acrylic rubber such as polyacrylic acid ester, and the like.

Examples of thermoplastic elastomers include styrene-butadiene block copolymers, hydrogenated styrene-butadiene block copolymers, ethylene-propylene elastomers, styrene-grafted ethylene-propylene elastomers, and thermoplastic polyester elastomers.

The styrene-butadiene block copolymer includes AB type, AB type
Includes A type, ABA taper type, radial teleblock type, etc.

As the method of modifying the component (b) with an epoxy group, an acid anhydride group, a carboxyl group, and an amino group, a vinyl compound having the functional group at the time of producing the rubber-like polymer, the thermoplastic elastomer and the graft copolymer. , Chain transfer agents, polymerization initiators, etc., such as epoxy group-containing unsaturated compounds, acid anhydride group-containing unsaturated compounds, carboxyl group-containing unsaturated compounds, amino group-containing unsaturated compounds, carboxyl group-containing chain transfer agents, amino A group-containing chain transfer agent, a method of polymerizing in the presence of a carboxyl group-containing polymerization initiator, the rubber-like polymer, the thermoplastic elastomer and the graft copolymer, a vinyl compound having the same functional group as above, There is a method of adding a chain transfer agent and a polymerization initiator.

A known polymerization method is used as a method for producing the above-mentioned, for example, an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, a bulk polymerization method and the like.

The production method can be obtained by kneading with an extruder, Banbury mixer, or kneader in the presence of peroxide, if necessary.

As the peroxide used here, all known organic peroxides can be used.

For example, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (tert
-Butylperoxy) hexane, 2,2'-bis (tert-
Butylperoxy) -p-diisopropylbenzene dicumyl peroxide, di-tert-butylperoxide, tert-butylperoxybenzoate, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane , 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, azobisisobutyronitrile, etc., and preferably 2,5-dimethyl-2,5-di (tert: butylperoxide). Oxy) hexane, 2,5-dimethyl-2,5-di (tert
-Butylperoxy) hexyne-3.

The amount of organic peroxide used is 100 parts by weight of rubber-like polymer, thermoplastic elastomer and graft copolymer.
It is 0.05 parts by weight or more, preferably 0.1 to 1 part by weight.

Examples of the epoxy group-containing unsaturated compound include unsaturated glycidyl esters represented by the following general formulas (I), (II) and (III), unsaturated glycidyl ethers, epoxy alkenes and p-glycidyl styrenes. And unsaturated epoxy compounds.

Specifically, glycidyl acrylate, glycidyl methacrylate, itaconic acid glycidyl esters, butenecarboxylic acid esters, allyl glycidyl ether, 2
-Methylallyl glycidyl ether, styrene-p-glycidyl ether, 3,4-epoxybutene, 3,4-epoxy-3-methyl-1-butene, 3,4-epoxy-1-pentene, 3,4-epoxy- Examples thereof include 3-methylpentene, 5,6-epoxy-1-hexene, vinylcyclohexene monoxide, p-glycidylstyrene and the like. These may be used alone or in combination of two or more.

Examples of the acid anhydride group-containing unsaturated compound include maleic anhydride, itaconic anhydride, chloromaleic anhydride, citraconic anhydride, butenyl succinic anhydride, tetrahydrophthalic anhydride, and the like.
It is maleic anhydride. These compounds are 1 type or 2 types.
Can be used with more than one species.

Examples of the unsaturated compound containing a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, maleic acid and the like, and acrylic acid and methacrylic acid are preferable. These unsaturated compounds containing a carboxyl group are used alone or in combination of two or more.

The amino group-containing unsaturated compound has the general formula Is a vinyl-based monomer having at least one of an amino group or a substituted amino group represented by, and specific examples include aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, aminopropyl methacrylate, and methacrylic acid. Acrylic acid or methacrylic acid alkyl ester derivatives such as phenylaminoethyl acid and cyclohexylaminoethyl methacrylate, vinylamine derivatives such as N-vinyldiethylamine and N-acetylvinylamine, allylamine, methacrylamine and N-methylallylamine Allylamine derivatives such as acrylamide and N
-Acrylamido derivatives such as methyl acrylamide and aminostyrenes such as p-aminostyrene are used. Among them, allylamine, aminoethyl methacrylate, aminopropyl methacrylate, aminostyrene and the like are particularly preferably used since they are economically available on an industrial scale. These unsaturated compounds containing an amino group or a substituted amino group are used alone or in combination of two or more.

Preferred examples of the carboxyl group-containing chain transfer agent include thioglycolic acid, thiomalic acid, and mercaptopropionic acid.

As the amino group-containing chain transfer agent, mercaptomethylamine, β-mercaptoethylamine, γ-mercaptopropylamine, N- (β-mercaptoethyl) -N-
Methylamine, N- (β-mercaptoethyl) -N-ethylamine, N- (β-mercaptoethyl) -N-phenylamine, N- (β-mercaptoethyl) -N-cyclohexylamine, bis- (4-aminophenyl) ) Disulfide, bis- (2-aminophenyl) disulfide, bis- (3-aminophenyl) disulfide, p
-Mercaptoaniline, o-mercaptoaniline, m-
Examples thereof include mercaptoaniline and hydrochlorides thereof, preferably β-mercaptoethylamine, γ-mercaptopropylamine, β-mercaptoethylamine hydrochloride, γ-mercaptopyrupyramine hydrochloride and bis- (4-aminophenyl) disulfide. And so on.

As the carboxyl group-containing polymerization initiator, a carboxyl group-containing azo compound and a carboxyl group-containing peroxide compound can all be used.

Preferred carboxyl group-containing azo compounds have the general formula And azobiscyanovaleric acid and azobiscyanopropionic acid are preferred examples.

Preferable examples of the carboxyl group-containing peroxide include succinic acid and peroxide.

As the amino group-containing polymerization initiator, α, α′-azobis (γ-amino-α, γ-dimethylvaleronitrile),
α, α′-azobis (γ-methylamino-α, γ-dimethylvaleronitrile), α, α′-azobis (γ-ethylamino-α, γ-dimethylvaleronitrile), α,
α′-azobis (γ-propylamino-α, γ-dimethylvaleronitrile), α, α′-azobis (γ-dimethylamino-α, γ-dimethylvaleronitrile), α,
Examples include α′-azobis (γ-diethylamino-α, γ-dimethylvaleronitrile), α, α′-azobis (γ-dipropylamino-α, γ-dimethylvaleronitrile) and p-aminobenzoyl peroxide. . Preferably α, α′-azobis (γ-amino-α,
γ-dimethylvaleronitrile).

As the styrene-based monomer, styrene, α-methylstyrene, methylstyrene, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene,
Examples thereof include dibromostyrene, p-tert-butylstyrene, ethylstyrene and vinylnaphthalene, and preferably styrene. These are used alone or in combination of two or more. Other vinyl monomers copolymerizable with the styrenic monomer can also be used, and these include acrylic acid esters, methacrylic acid esters, acrylonitrile, methacrylonitrile and the like.

The various functional groups used as the modifying group of the component (b) in the present invention are preferably modified with an epoxy group or a carboxyl group from the viewpoint of their thermal stability to obtain a good thermoplastic resin composition. May be Of these, epoxy groups are preferable from the viewpoint of processability of the composition.

Epoxy group, acid anhydride group, carboxyl group, amino group-containing unsaturated compound, chain transfer agent and polymerization initiator,
The component (b) is contained in an amount of 0.01 to 30% by weight, preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight.

If it is less than 0.01% by weight, impact resistance may be poor and peeling may occur. If it exceeds 30% by weight, impact resistance is poor.

The epoxy group, acid anhydride group, carboxyl group, and amino group equivalents in the component (b) are 5 × 10 ² to 1 × 1 in terms of impact resistance.
The range of 0 ⁶ g / eqiv., Preferably 1 × 10 ^{3 to} 5 × 10 ⁵ g / eqiv., And more preferably 1 × 10 ^{3 to} 3 × 10 ⁵ g / eqiv. These can be measured by titration or infrared spectroscopy.

The amount of component (b) used in the present invention is 1 to 99% by weight,
If the amount used is less than 1% by weight, impact resistance is poor. If it exceeds 99% by weight, impact resistance is poor.

The thermoplastic resin composition of the present invention can be manufactured by kneading with a known kneader such as various extruders, Banbury mixers, kneaders, and rolls.

The melt-kneading temperature is preferably in the range of 250 ° C to 350 ° C.

When using the thermoplastic resin composition of the present invention, glass fiber, carbon fiber, metal fiber, glass beads, asbestos,
Fillers such as wollastonite, calcium carbonate, talc and barium sulfate can be used alone or in combination.

Among these fillers, glass fibers and carbon fibers preferably have a fiber diameter of 6 to 60 μm and a fiber length of 30 μm or more.

Further, these fillers are contained in the thermoplastic resin composition in an amount of 5 to 150.
It is preferable to contain by weight.

Furthermore, known additives such as flame retardants, antioxidants, plasticizers, colorant lubricants, and silicone oils can be added and used.

Further, depending on the required performance, other polymers such as polyethylene, polypropylene, polystyrene, styrene-acrylonitrile copolymer, styrene-methyl methacrylate copolymer, polysulfone, polyether sulfone, PPS, polyether ether ketone, A vinylidene fluoride polymer, a polyimide or the like can be appropriately blended.

The thermoplastic resin composition of the present invention can be used as various molded articles by injection molding, sheet extrusion, vacuum molding, profile molding, foam molding and the like.

e. Examples Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but these are merely examples and do not limit the content of the present invention. In the following examples, parts and% mean parts by weight and% by weight, respectively.

Production Example The component (b) of the present invention used in Examples and Comparative Examples was obtained by the following method.

1) Polymer B-1 (glycidyl methacrylate modified ethylene propylene rubber) Ethylene propylene rubber (JSR EP manufactured by Nippon Synthetic Rubber Co., Ltd.)
-02P) 100 parts of glycidyl methacrylate 5
Part, organic peroxide (Kayahexa AD manufactured by Kayaku Nouri Co., Ltd.) 0.3 part are premixed, and a 55 mmφ extruder (single screw full flight type screw) is used at 200 ° C.
Heat treatment was performed at a screw rotation speed of 30 rpm (residence time of about 4 minutes).

The obtained reaction product was extracted with acetone (boiling point × 2 hours), and then the epoxy equivalent was determined by a titration method. The epoxy equivalent was 5680 g / eqiv., And the addition amount was 2.5%.

2) Polymers B-2, 3, 6-9 Polymers B-2, 3, 6-9 were prepared by changing the rubber species, the monomer species and the amount of monomers under the production conditions of the polymer B-1. Got The results are shown in Table-1.

Examples and Comparative Examples Nylon 4,6 and the above various polymers were mixed at the composition ratios shown in Table 2, and melt-kneaded at a barrel temperature of 280 ° C to 330 ° C using a co-rotating twin-screw extruder. Then, a pellet-shaped thermoplastic resin composition was obtained. After sufficiently dried with a vacuum dryer, a test piece was prepared with an injection molding machine, and impact resistance and heat resistance were measured by the following methods.

The results are shown in Table-2.

Impact resistance: Measured according to ASTM D256 at 23 ° C, thickness 1/4 ", notched.

Heat resistance According to ASTM D648, the load was measured at 18.6 kg / cm ² .

Appearance of molded product A flat molded product was manufactured, and the state of sink marks was visually evaluated according to the following evaluation criteria.

Evaluation criteria ○: Almost no sink mark.

Δ: There is a slight sink mark.

X: The sink mark is large.

As seen in Comparative Example-1, the nylon 4 and 6 resins have high heat resistance but poor impact resistance.

As seen in Comparative Example-2, when the usual rubber-like polymer is added, the impact resistance is slightly improved, and the heat resistance is greatly reduced.

As seen in Comparative Example-3, when nylon 6,6 resin is used and the component (b) of the present invention is used, impact resistance is improved but heat resistance is poor.

As seen in Examples 1 to 9, the composition of the present invention provides a thermoplastic resin composition having excellent impact resistance and heat resistance.

e. Effect of the Invention The thermoplastic resin composition of the present invention improves the drawbacks of the conventional nylon 4,6 resin alone and has excellent heat resistance and impact resistance, and therefore has practical value as various molding materials. Is big.

Claims (1)

[Claims] 1. (a) Nylon 4,6 resin 1 to 99% by weight (b) Rubber modified with at least one functional group selected from an epoxy group, an acid anhydride group, a carboxyl group and an amino group. Polymers (excluding those obtained by graft-polymerizing an unsaturated dicarboxylic acid or its derivative on an ethylene copolymer and ionomer resins) having a functional group amount of 5 × 10 ² to 1 × 10 ^6. A thermoplastic resin composition comprising 99 to 1% by weight of a rubbery polymer having a g / eq iv.