JPH02255761A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain a polyamide resin composition having excellent heat resistance, rigidity, impact resistance and dimensional stability by mixing a nylon 46 resin with mica and a specific modified rubber polymer under melting. CONSTITUTION:The objective polyamide resin composition can be produced by melting and mixing (A) 50-80wt.% of a nylon 46 resin having a relative viscosity of preferably 2-4.5 (especially 2.5-3.5) with (B) 15-45wt.% of mica, preferably a flaky alumina silicate having specific gravity of 2.74-2.95, particle diameter of 20-600mum and Mohs hardness of 2.4-3 and optionally treated with a silane coupling agent, etc., and (C) 5-20wt.% of a modified rubber polymer produced by modifying a rubber polymer (e.g. EP rubber) with 0.01-30wt.% of a compound having one or more functional groups selected from epoxy group, acid anhydride group, carboxyl group and amino group (e.g. maleic anhydride or glycidyl methacrylate).

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a polyamide resin composition that has excellent heat resistance, dimensional stability, and improved impact resistance.

b. Prior Art A polyamide resin composed of tetramethylene diamine and adipic acid and their functional derivatives is known as nylon 46 resin.

This nylon 46 resin has excellent mechanical strength such as tensile strength and bending strength, as well as excellent heat resistance and sliding properties, so it has great practical value as a useful engineering plastic.

However, nylon 46 resin has the disadvantage of poor dimensional stability. In order to improve this drawback, there is a method of adding mineral reinforcing agents, etc., but this method does not sufficiently improve impact resistance.

Problems to be Solved by the C0 Invention The present inventors tried to improve the dimensional stability by adding various inorganic fillers to nylon 46 resin, but no improvement in the impact resistance of the resulting resin was observed. However, it could not be put to practical use.

Therefore, the present inventors conducted intensive studies on thermoplastic resin compositions with excellent heat resistance, dimensional stability, and impact resistance, and found that by melt-mixing mica and a specific modified rubbery polymer with nylon 46 resin, It was discovered that a thermoplastic resin composition having unprecedented performance could be obtained, and the present invention was achieved.

Means for solving the d0 problem The present invention provides polytetramethylene adipamide (a) 50~
80% by weight, mica (b) 15 to 45% by weight, and a modified rubbery polymer modified with a compound having one type of functional group selected from epoxy groups, acid anhydride groups, carboxyl groups, and amino groups. The present invention provides a polyamide resin composition characterized in that it is formed by melt-mixing 5 to 20% by weight of a coalesce (C).

The present invention will be explained in more detail below.

The nylon 46 resin used as component (a) of the present invention has the following general formula (%) and has a relative viscosity (η:
(measured at a measurement temperature of 30° C., using 97% sulfuric acid, and an el concentration I K /100ml) is preferably in the range of 2 to 4.5, more preferably 2.5 to 3.5,
Particularly preferably, it is in the range of 3 to 3.5.

The amount of nylon 46 used as component (a) is 50 to 80% by weight, preferably 60 to 75% by weight. If the amount used is less than 50% by weight, impact resistance, moldability, etc. will be significantly reduced, and if it exceeds 80% by weight, no improvement in dimensional stability will be observed.

The mica component (b) used in the present invention is, for example, KA1
2 (AISi301o)(OH)2 is an alumina silicate, which is a flaky mineral with specific gravity of 2.74 to 2.95, particle size of 20 to 600μ, and Mohs hardness of 2°4·-3. Fillers are preferred. Furthermore, mica that has been pretreated with a silane coupling agent or the like can be used if necessary.

The amount of mica used as component (b) is 15 to 45% by weight, preferably 25 to 35% by weight. Usage amount is 1
If it is less than 5% by weight, the effect of improving dimensional stability will be poor, and if it exceeds 45% by weight, impact resistance and molded appearance will deteriorate, which is not preferable.

The rubbery polymer of the modified rubbery polymer as component (e) of the present invention is a rubbery polymer, a thermoplastic elastomer, or a rubbery polymer obtained by graft polymerizing a monomer mainly containing a styrene monomer to these. It refers to the resulting graft copolymer, and the rubber-like polymer, thermoplastic elastomer, and graft copolymer referred to herein can also be used as a mixture of two or more types.

To explain in more detail, the rubbery polymer is
Polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, diene rubber such as polyisoprene, olefin rubber such as ethylene-propylene copolymer and ethylene-propylene-polyene copolymer, polyacrylic acid ester, etc. Examples include acrylic rubber.

Examples of the thermoplastic elastomer include styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, ethylene-propylene elastomer, styrene-grafted ethylene-propylene elastomer, thermoplastic polyester elastomer, ethylene ionomer resin, etc. There is.

Note that the styrene-butadiene block copolymer contains A
Includes B type, ABA type, ABA taper type, radial teleblock type, etc. Furthermore, hydrides thereof are also included.

Furthermore, the above-mentioned graft copolymer refers to a latex-like rubber-like polymer, a polymer obtained by emulsion graft polymerization of a styrene monomer to a thermoplastic elastomer, or a polymer obtained by emulsion graft polymerization of a styrene monomer to a rubber-like polymer or a thermoplastic elastomer. The monomer is dissolved in a solvent containing the main component, and the solution is subjected to bulk polymerization.
Refers to polymers obtained by polymerization by methods such as solution polymerization and suspension polymerization.

In the present invention, when producing the modified rubbery polymer (c) from the above-mentioned rubbery polymer, at least one group selected from epoxy groups, acid anhydride groups, carboxyl groups, and amino groups is used.
Compounds with various functional groups are used.

As a method for producing a modified rubbery polymer, (1) during the production of the rubbery polymer, thermoplastic elastomer, and graft copolymer, a vinyl compound having the above-mentioned functional group, a chain transfer agent, a polymerization initiator, etc., such as an epoxy group; Containing unsaturated compounds, unsaturated compounds containing acid anhydride groups, unsaturated compounds containing carboxyl groups, unsaturated compounds containing amino groups, chain transfer agents containing carboxyl groups, chain transfer agents containing amino groups, polymerization initiation containing carboxyl groups ■ A method of polymerizing in the presence of an amino group-containing polymerization initiator, ■ The above rubbery polymer, thermoplastic elastomer and graft copolymer ■
There are methods of adding a vinyl compound having a bipedal functional group, a chain transfer agent, a polymerization initiator, etc.

As the production method (2), known polymerization methods are applied, such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization. The manufacturing method (2) includes a method of kneading in an extruder, a Banbury mixer, or a 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-diisopropylbenzenedicumyl peroxide,
Di-tert-butyl peroxide, tert-butyl peroxybenzoate, 1,1-bis(tert-butyl peroxide)
(t-butylperoxy)-3,3,5-1-limethylcyclohexane, 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, azobisisobutyronitrile, etc., and preferred is 2,5-dimethyl-2,5-di(t
ert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane-3.

The amount of peroxide used is 0.05 parts by weight or more, preferably 0.1 to 1 part by weight, per 100 parts by weight of the rubbery polymer, thermoplastic elastomer or graft copolymer.

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

is a hydrocarbon group. ) +0- or ÷.

R' R-C-CH2 \1 (m) (R is a C2-18 hydrocarbon group having an ethylenically unsaturated bond. R' is hydrogen or a methyl group.) Specifically, glycidyl acrylate , glycidyl metafurerate, itaconic acid glycidyl esters, butene carboxylic acid esters, allyl glycidyl ether, 2
-Methyl allyl glycidyl ether, styrene-p-glycidyl ether, 3,4-epoxybutene, 3,4-
Epoxy-3-methyl-1-butene, 3,4-epoxy-1-pentene, 3,4-epoxy-3-methylpentene, 5,6-epoxy-1-hexene, vinylcyclohexene monoxide, p-glycidylstyrene, etc. can be mentioned. These can be used alone or in combination of two or more.

Examples of unsaturated compounds containing an acid anhydride group include maleic anhydride, itaconic anhydride, chloromaleic anhydride, citraconic anhydride, butenylsuccinic anhydride, and tetrahydrophthalic anhydride, and particularly preferred compounds include maleic anhydride. It is.

These compounds can be used alone or in combination of two or more.

Examples of carboxyl group-containing unsaturated compounds include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid,
Examples include maleic acid, and acrylic acid and methacrylic acid are preferred. These carboxyl group-containing unsaturated compounds may be used alone or in combination of two or more.

As the amino group-containing unsaturated compound, the general formula (wherein R
1 represents hydrogen, methyl group, ethyl group, R2 represents hydrogen,
Alkyl group having 1 to 12 carbon atoms, alkanoyl group having 2 to 12 carbon atoms, phenyl group having 6 to 12 carbon atoms, 6 to 1 carbon atoms
2 cycloalkyl group or derivatives thereof. ), and specific examples include aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, and aminopropyl methacrylate. , alkyl ester derivatives of acrylic acid or methacrylic acid such as phenylaminoethyl methacrylate and cyclohexylaminoethyl methacrylate, vinylamine derivatives such as N-vinyldiethylamine and N-acetylvinylamine, allylamine, methacrylamine and Allylamine derivatives such as N-methylallylamine, acrylamide and acrylamide derivatives such as N-methylallylamine, and aminostyrenes such as p-aminostyrene are used.

Among them, allylamine, aminoethyl methacrylate, aminopropyl methacrylate, aminostyrene, and the like are particularly preferably used because they can be obtained economically on an industrial scale. These amino group- or substituted amino group-containing unsaturated compounds may be used alone or in combination of two or more.

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

Examples of amino group-containing chain transfer agents include 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-amino phenyl) disulfide, bis-(2-aminophenyl) disulfide, bis-(3-aminophenyl) disulfide,
p-mercaptoaniline, O-mercaptoaniline, m
-mercaptoaniline and their hydrochlorides, preferably β-mercaptoethylamine, γ-mercaptopropylamine, β-mercaptoethylamine hydrochloride, γ-mercaptopyropylamine hydrochloride and bis-(4-aminophenyl)di Such as sulfide.

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

Preferred carboxyl group-containing azo compounds include those represented by the general formula % (wherein R is hydrogen, methyl, or ethyl group, and n is 1 or 2). , azobiscyanovaleric acid, and azobiscyanopropionic acid.

Suitable examples of carboxyl group-containing peroxides include succinic acid and peroxide.

Examples of amino group-containing polymerization initiators include 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).

From the viewpoint of thermal stability, it is better to modify the various functional groups used as modifying groups in the present invention with epoxy groups or carboxyl groups to obtain a better thermoplastic resin composition. Among these, epoxy groups are preferred from the viewpoint of processability of the composition. Epoxy group, acid anhydride group used for modification,
An unsaturated compound containing a functional group such as a carboxyl group or an amino group, a chain transfer agent, and a polymerization initiator are contained in component (c) in an amount of 0.01 to 30% by weight, preferably 0.1 to 20% by weight, and further It is preferably contained in a range of 0.5 to 10% by weight. If it is less than 0.01% by weight, impact resistance will be poor and peeling may occur.

If it exceeds 30% by weight, impact resistance will be poor.

The amount of modified rubbery polymer (C) used in the present invention is 5 to 5.
The amount is 20% by weight, preferably 10 to 15% by weight. If the amount used is less than 5% by weight, the effect of improving impact resistance will be poor, and if it exceeds 20% by weight, mechanical strength, heat resistance, etc. will decrease, which is not preferable.

The method of blending the resin composition of the present invention is not particularly limited, but for example, a method of mixing in a tumbler, Henschel mixer, etc., and then melt-mixing in a batch kneader, Banbury mixer 1 single screw or twin screw extruder can be mentioned.

The composition of the present invention may optionally contain fillers, other known polymers (e.g., polyolefins, modified polyolefins, polytetrafluoroethylene, polyvinylidene fluoride, etc.), pigments, flame retardants, anti-aging agents. , stabilizer,
Antistatic agents and the like can be added.

The resin composition of the present invention has excellent heat resistance, mechanical strength, dimensional stability, and impact resistance, so it can be used in air ducts,
We can provide molded products such as various exterior materials, door handles, brake levers, and other functional parts.

e. Examples Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples. The resin compositions obtained in Examples and Comparative Examples were evaluated by the following test method.

Test method> ■Tensile strength: ASTM D638 Tensile speed 50m5+/min ■Bending strength = ASTM D790 Bending speed 15mm/min ■ Bending modulus: ASTM D79° Bending speed 15+am/min ■ Izot impact strength: ASTM D25623℃
, with a notch ■ Load deflection temperature (HDT): ASTM D648, no annealing ■ Dimensional stability: A disk with a thickness of 2 mm and a diameter of 4 inches was molded, and after being left at 23°C and 50% relative humidity for 24 hours, the maximum warpage direction was determined. One end was fixed to the substrate, the distance from the other end to the substrate was read, and the distance was measured without contact using a microscope, and that distance was taken as the amount of warp deformation.

Examples 1 to 4 Table 1 shows nylon 46, mica, and modified rubbery polymer.
Mix in the proportions shown in , and then use an extruder to
The mixture was melt-mixed and molded at a cylinder temperature of 30° C. to obtain a pellet. This pellet was molded into a test piece using an injection molding machine. From the results shown in Table-1,
It was found that the molded article of the present invention has the physical properties targeted by the present invention.

Nylon 46: η. 13.0 Mica: specific gravity 2.85, flake diameter 200-600μ Modified rubbery polymer: 10% by weight epoxy-based columnar P rubber Comparative Examples 1-4 Nylon 46 used in Example 1, mica, modified A resin composition was prepared using a rubbery polymer and had the composition shown in Table 1, and its physical properties were evaluated in the same manner as in Example 1. The results are shown in Table-1.

Comparative Example 1 is a composition in which nylon 46 and mica are outside the scope of the present invention, and the impact resistance is not improved, which is not preferable.

In Comparative Example 2, the modified rubbery polymer of the present invention was not used, and the desired impact resistance was not obtained.

Comparative Example 3.4 is a composition in which the mica is outside the scope of the present invention, has low rigidity, heat resistance, and dimensional stability, and does not exhibit the desired physical properties, which is not preferable.

Comparative Example 5 was evaluated in the same manner as in Example 1 with the addition of an unmodified rubbery polymer, but the desired impact resistance was not improved, which is not preferable.

Comparative Example 6 is nylon 4 with the same content as Example 3.
When nylon 66 is used instead of nylon 6, the heat resistance and rigidity are inferior to the case where nylon 46 of the present invention is used, which is not preferable.

Comparative Example 7 is a case where kaolin is used instead of mica in Example 3, and the balance of rigidity, heat resistance, dimensional stability, etc. is not sufficient.

Comparative Example 8 is a case where a single piece of nylon 46 is used, and the rigidity,
The heat resistance and dimensional stability were insufficient, and the desired physical properties could not be obtained.

The following margin f0 Effect of the invention The polyamide resin composition of the present invention has rigidity, impact resistance, and heat resistance by blending a specific mica filler and a rubbery polymer with nylon 46 and molding it within a certain range. sex,
A resin composition having a well-balanced physical property of dimensional stability can be obtained.

Therefore, because the resin composition of the present invention has an excellent balance of physical properties, it
It provides molded products such as interior parts and various parts for the electrical and electronic fields, and has extremely high industrial value.

Patent applicant: Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] Contains 50 to 80% by weight of polytetramethylene adipamide (a), 15 to 45% by weight of mica (b), and at least one functional group selected from an epoxy group, an acid anhydride group, a carboxyl group, and an amino group. A polyamide resin composition characterized in that it is formed by melt-mixing 5 to 20% by weight of a rubbery polymer (c) modified with a compound.