JPH07103265B2 - Thermoplastic polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a thermoplastic polymer composition having improved impact resistance or flexibility and compression set characteristics, and excellent heat resistance and mechanical strength balance. Regarding

[Prior Art] A large number of thermoplastic compositions comprising polyamide and / or polyamide elastomer and rubber have been proposed. JP-B-55-44108 and JP-A-57-147519 concerning compositions of polyamide and olefin copolymer, or polyamide and at least 80% gel content 1,3
JP-A-52-105952 discloses a composition comprising a homopolymer of -butadiene and a copolymer obtained by copolymerizing 1,3-butadiene with styrene, vinylpyridine, acrylonitrile or methacrylonitrile.

However, since such a thermoplastic polymer composition is a material that has rubber-like elasticity and thermoplastic properties, it is injection-molded or extrusion-molded in terms of processability as compared with conventional vulcanized rubber. And blow molding is possible. However, from the viewpoint of material properties, it has a drawback that the shape after deformation cannot be completely restored, that is, it is inferior in terms of compression set.

The former of the above patents proposes improvement of mechanical strength by interaction of functional groups of polyamide and polyolefin, but this thermoplastic polymer composition also has a poor compression set. Further, in the latter patent, it is proposed to improve tensile strength by melt-mixing a copolymer of polyamide and 1,3-butadiene and adding a vulcanizing agent for rubber to vulcanize the rubber. . However, in this method, a copolymer of polyamide and 1,3-butadiene is cross-linked with a vulcanizing agent, which takes a long time for vulcanization. It was revealed by the study of the present inventors that the rubber has a large particle size and is not uniform, and is inferior in bending resistance and fluidity.

On the other hand, there are many proposals for blending polyamide resin with rubber for the purpose of improving impact resistance. For example, JP-A-53-12
956, JP-A-53-21252 and the like. It has been shown that acrylonitrile and a butadiene copolymer (hereinafter NBR) are effective for improving the impact resistance of polyamide. However, the system to which NBR is added has a good impact resistance as a normal value, but has a problem that the impact resistance after heat aging significantly decreases.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems of the prior art, and is a thermoplastic polymer excellent in impact resistance, compression set characteristics, heat resistance and molding processability. It is intended to provide a composition.

[Means for Solving Problems] The present invention provides: X) polyamide and / or polyamide elastomer 20 to
99% by weight, and Y) a thermoplastic polymer composition comprising 80 to 1% by weight of a copolymer rubber having a composition represented by the following [I] and having a gel content of 20% by weight or more.

[I] (A) a- (B) b- (C) c- (D) d-
(E) e However, although A to E and a to e are defined by the following, the bonding modes of the monomers A to E may be any.

A: unsaturated nitrile B: conjugated diene C: α, β unsaturated carboxylic acid ester D: crosslinkable monomer E: having at least one selected from a carboxyl group, amino group, epoxy group and hydroxyl group as a functional group Monomer a: 10 to 50% by weight b: 5 to 50% by weight c: 10 to 85% by weight d: 0.1 to 10% by weight e: 0.1 to 20% by weight, and a + b + c + d + e = 100% by weight.

Examples of the X) polyamide component of the present invention include polylactams such as nylon 6, nylon 11 and nylon 12; dicarboxylic acids such as nylon 4,6, nylon 6-6, nylon 6-10, nylon 6-12 and diamines. Polyamides obtained from and such as nylon 6 / 6-6, nylon 6 / 6-10, nylon 6/12, nylon 6 / 6-12, nylon 6/66 / 6-10, nylon 6/66/12, etc. Copolyamides; nylon 6 / 6T
(T: terephthalic acid component), semi-aromatic polyamides obtained from an aromatic dicarboxylic acid such as isophthalic acid and 1,4 diamino-2,6-dimethylbenzene or an alicyclic diamine. Of these, nylon 11 and nylon 1 are most preferable.

Further, as the polyamide elastomer as one of the X) polyamide components, those synthesized by a condensation reaction of a polyether having a hydroxyl group at the chain end and a polyamide can be mentioned.

Examples of the polyether having a hydroxyl group at the chain end include a chain or branched polyoxyalkylene glycol, such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol or a mixture thereof, or a copolyol derived from the above compound. It is ether. The average molecular weight of the polyether is generally 200 to 6,000, preferably 400 to 3,000.

The ratio of the weight of polyoxyalkylene glycol to the weight of all components is usually 5 to 85%, preferably 10 to 50%.

As the polyamide, the number of carbon atoms in the hydrocarbon chain is 4 to
A lactam or an amino acid which is 14, for example caprolactam, enantolactam, dodecalactam, undecanolactam, dodecanolactam, 11-amino-undecanoic acid or 12-aminododecanoic acid as a starting material, or a condensation product of a dicarboxylic acid and a diamine. Products such as hexamethylenediamine and adipic acid, azelaic acid, sebacic acid, and 1,12-dodecanedioic acid, and nylon 6-6 and 6-9, which are condensation products of nonamethylenediamine and adipic acid. , 6-10, 6-12 and 9-6.

In the synthesis reaction of polyamide, the diacid used as a chain limiting agent makes it possible to obtain a polyamide having a carboxylic acid at the terminal as well, but a dicarboxylic acid, preferably an aliphatic dicarboxylic acid having 4 to 20 carbon atoms, Examples are succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid.

Alicyclic or aromatic diacids can also be used. These diacids are used in amounts which are in excess of those required to obtain a polyamide having the desired average molecular weight according to known calculation methods currently used in the field of polycondensation reactions.
The average molecular weight of dicarboxylic acid polyamide is usually 300 to 15,00
It is 0, preferably 800 to 5,000.

The polycondensation reaction for producing a polyamide elastomer is performed in the presence of a catalyst with stirring at 0.05-5 mmHg.
It is carried out at a temperature higher than the melting point of the components used under a moderately high vacuum. The temperature is selected so that the reaction components are maintained in a fluidized state. That is, generally at 100 ~ 400 ℃, preferably
200 to 300 ° C.

The reaction time can generally vary from 10 minutes to 10 hours,
It is preferably about 1 to 7 hours.

The reaction time depends on the properties of the polyoxyalkylene glycol. It must be sufficiently long so that it can obtain the final viscosity necessary to obtain a product with satisfactory properties as required for moldable and / or extrudable plastic materials. .

However, the carboxylic acid groups and the hydroxyl groups must be in an equimolar relationship so that the polycondensation reaction occurs under optimal conditions to obtain the desired product.

Examples of the unsaturated nitrile (A) used in the gel-containing copolymer rubber Y) according to the present invention include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, and the like, and acrylonitrile is particularly preferable.

The content of unsaturated nitrile is 10 to 50% by weight, and if it is less than 10% by weight, the compatibility with the polyamide component is lowered and the physical properties,
Moldability is poor. On the other hand, when it is 50% by weight or more, the rubber-like properties are poor, and the impact resistance improving effect and the flexibility imparting effect are poor.

Further, the conjugated diene (B) has the general formula (R, R'and R "are hydrogen or an alkyl group. Specific examples thereof include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, piperylene and 1,3-hexadiene. However, butadiene and isoprene are particularly preferable.

This content is 5 to 50% by weight, preferably 10 to 35% by weight. If it is less than 5% by weight, the impact resistance improving effect is poor, and if it exceeds 50% by weight, the heat resistance, which is a feature of the present invention, is poor.

The α, β unsaturated carboxylic acid ester (C) has the general formula: (R ₁ is hydrogen or a methyl group, R _{2 is} an alkyl group having 1 to 12 carbon atoms). Specific examples thereof include methyl acrylate, ethyl acrylate, -n-propyl acrylate,
Acrylic acid-n-butyl, acrylic acid-n-hexyl,
Acrylic acid-n-octyl, 2-ethyl acrylate-
Hexyl, dodecyl acrylate, 2-methoxyethyl acrylate, methyl methacrylate, methacrylic acid-n-
Butyl, methacrylic acid-n-octyl, methacrylic acid-
2-ethyl-hexyl, methacrylic acid-n-dodecyl and the like can be mentioned. Of these, preferred are methyl acrylate, ethyl acrylate, -n-butyl acrylate, 2-ethyl-hexyl acrylate, ethyl methacrylate, -n-butyl methacrylate, methacrylic acid-2.
-Ethyl-hexyl, particularly preferred are -n-butyl acrylate and ethyl acrylate.

The content of (C) is 10-85% by weight, preferably 40-
It is 85% by weight. If it is less than 1% by weight, the heat resistance is poor, and if it is 85% by weight or more, the dispersibility in the polyamide component is poor, and a good effect of improving impact resistance cannot be obtained.

Examples of the crosslinkable monomer (D) include aromatic compounds such as divinylbenzene and 1,3,5-trivinylbenzene,
Ester compounds such as diallyl phthalate and diallyl fumarate, acrylic acid such as trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate Esters can be mentioned.

Its content is from 0.1 to 10% by weight, and if it is less than 0.1% by weight, a copolymer rubber having a gel content, which is a feature of the present invention, cannot be obtained. That is, the gel content of the copolymer rubber Y) is preferably 20% or more. When the gel content of the copolymer rubber Y) is 20% or more, it becomes easy to disperse it in the polyamide component and good moldability is obtained. Furthermore, a thermoplastic polymer composition having good mechanical strength and compression set can be obtained.

The gel content here is a value measured by the following method. Precisely weigh about 1 g of rubber and put it in an Erlenmeyer flask, 100 m
Add 1 liter of tetrahydrofuran and let stand at 25 ° C for 24 hours. Next, a filtration operation was carried out using a 200 mesh wire mesh, the wire mesh impervious portion was vacuum dried, and the amount thereof was determined. The gel content is determined by W / W ₀ × 100 (%), where W ₀ (g) is the amount of precisely weighed rubber and W (g) is the amount of wire mesh failure.

When the content of the crosslinkable monomer (D) is less than 0.1% by weight, it is difficult to increase the gel content to 20% by weight or more and 10% by weight.
In the above case, the copolymer rubber Y) becomes brittle, and the effect of improving impact resistance and the effect of imparting flexibility are poor.

Among the functional group-containing monomers (E) used in the copolymer rubber Y) of the present invention, examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, maleic acid and fumaric acid. Among these, as the dicarboxylic acid, an acid anhydride can also be used. Examples of the monomer having an amino group include dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth).
Examples thereof include tertiary amino group-containing monomers such as acrylate and dibutylaminoethyl (meth) acrylate.

Further, as the monomer (E) having a hydroxyl group,
1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate and the like can be mentioned.

Furthermore, as the monomer (E) having an epoxy group,
Examples thereof include glycidyl (meth) acrylate, allyl glycidyl ether, and vinyl glycidyl ether.
The monomers having these functional groups can be used alone or in combination of two or more.

The content of the monomer (E) is 0.1 to 20% by weight, preferably 0.1 to 10% by weight. If it is less than 0.1% by weight, a good effect of improving impact resistance cannot be obtained, and if it is 20% by weight or more, the glass transition temperature of the copolymer rubber Y) becomes high and the cold resistance becomes poor.

The mixing ratio of the above components is 20 to 99 of the polyamide component of X).
% By weight, Y) copolymer rubber 80 to 1% by weight. When the content of the polyamide component is 20% or less, the processability is remarkably reduced, the thermoplastic property is impaired, and a molded product which is practically preferable cannot be obtained. The preferred mixing ratio is X) component 40 to 90
%, Y) component 60 to 10% by weight.

In order to exert the effects of the invention in the thermoplastic polymer composition of the present invention, the temperature at the time of mixing is adjusted to the polyamide component X).
It is preferable to set the melting point to or above. When the temperature of the polyamide component at the time of mixing is lower than the melting point, not only the required torque at the time of mixing becomes high, but also the mixing becomes insufficient, and the physical properties of the resulting composition are not sufficiently exhibited, which is not preferable. On the other hand, if the temperature during mixing is too high, the soft component of the copolymer rubber Y) causes thermal decomposition deterioration and the like, and a composition having high physical properties cannot be obtained, which is not preferable.

Therefore, the mixing temperature is preferably 5 ° C. or higher, more preferably 10 ° C. or higher, more preferably 300 ° C. or lower than the melting point of the polyamide and / or polyamide elastomer.
More preferably, it is 280 ° C or lower.

The method used for mixing the polyamide component X) and the copolymer rubber Y) is not particularly limited, and a known method such as an open mixing roll, a non-open Banbury mixer, an extruder, a kneader, or a continuous mixer may be used. You can

The thermoplastic polymer composition of the present invention, a filler in a range that does not impair the moldability and mechanical strength, such as calcium carbonate, calcium silicate, clay, kaolin, talc,
Silica, diatomaceous earth, mica powder, asbestos, alumina,
Barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite, carbon fiber, glass fiber, etc., or colorant,
For example, carbon black, ultramarine blue, titanium oxide, zinc white,
Red iron oxide, dark blue, azo pigment, nitroso pigment, lake pigment, phthalocyanine pigment and the like can be added.

Further, a process oil or a softener for mineral oil-based rubber called extender oil, dioctyl phthalate, dibutyl phthalate, diethyl phthalate, dimethyl phthalate, tricresyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trimellitic acid. Ester, dioctyl adipate, dioctyl azelate, dioctyl sebacate, plasticizers such as epoxy fatty acid ester and liquid NBR, liquid acrylic rubber, liquid rubber such as liquid polybutadiene rubber, butyl amide benzenesulfonate, POBO manufactured by Yoshitomi Pharmaceutical Co., Ltd., Fluidity can be improved by blending a plasticizer for nylon such as Sanso Sizer N400 manufactured by Shin Nippon Rika Co., Ltd. within a range not impairing the mechanical strength.

Furthermore, during mixing, phenylenediamine-based antioxidants (Ouchi Shinko Chemical Co., Ltd. Nocrac CD, Nocrac TD, Nocrac G1, Nocrac WHITE) and imidazole antioxidants (Ouchi Shinko Chemical Co., Ltd. Nocrac MB , Nocrac MMB) and hindered phenolic antioxidants (BH
T, Nocrac 300) can be added.

Of course, the polymer composition of the present invention can be used by mixing with other resin or elastomer.

The applications of the thermoplastic polymer composition of the present invention include body panels, bumper parts, molding side shields, steering wheels, joint boots, automobile parts such as strut suspension boot handles, shoe soles, footwear such as sandals, wire coating, Electrical parts such as connectors, cap plugs, gears, golf club grips, baseball bat grips, automobile and motorcycle grips,
Swimming fins, leisure products such as underwater glasses, gaskets, waterproof cloth, hydraulic hoses, fuel hoses, freon hoses, power steering hoses, coil tubes, packing, rolls, garden hoses, belts, damping materials for damping steel plates, etc. Can be used as.

[Examples] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

The physical properties were measured by the following methods.

Example 1 Using the emulsion polymerization formulation shown below, it was produced by carrying out emulsion polymerization in an autoclave with an internal volume of 20 under the following polymerization conditions.

Emulsion polymerization formulation Weight part Butadiene 15 Acrylonitrile 25 Ethyl acrylate 52 Methacrylic acid 7 Divinylbenzene 1 Water 200 Dodecylbenzene Sodium sulfonate 3.5 Tertiary dodecyl mercaptan 0.25 Calcium phosphate 0.3 Ferrous sulfate 0.005 Paramenthane hydroperoxide 0.02 Polymerization conversion rate is 90 After reaching 100%, 0.2 per 100 parts of monomer
A part of hydroxylamine sulfate was added to terminate the polymerization. The obtained polymerization product is heated, and the residual monomer is recovered by steam distillation under reduced pressure at about 70 ° C. Then, 1 part of alkylated phenol is added as an antioxidant, and unreacted monomer is removed by steam distillation. Was removed and calcium chloride was added to coagulate. Next, the solidified polymer was washed with water and dried using a vacuum dryer.

The polymerization conditions and properties of the copolymer rubber thus obtained are shown in Table 1 below.

Next, the obtained copolymer rubber (a) and nylon-6 (Toray Milan CM1021) were mixed in a ratio of 20/80 using a Haake Rheomex 254 type small extruder at 280 ° C for 5 minutes. After that, it was pelletized and dried, and a test piece for Izod impact test according to JIS K7110 and a test piece for bending strength test as shown in JIS K7203 were molded by a 0.5 ounce injection molding machine. The Izod impact test was performed after making a 1/4 ″ notch on the test piece, and the test piece was put in a thermostat set at 120 ° C. for 120 hours in the same manner.

The bending strength test was performed at a test speed of 50 mm / min.

The results are shown in Table-2.

Examples 2 to 5, Comparative Examples 1 to 4 The copolymer rubbers shown in Table 1 were obtained in the same procedure as the method shown in Example 1. The evaluation results of the kneaded composition with Nylon-6 are summarized in Table-2.

Example 6 50 parts by weight of the copolymer rubber (a) and 50 parts by weight of PEBAX5533 manufactured by ATOCHEM, a polyamide elastomer of France, were kneaded at 190 ° C. with a closed type kneading machine Rheomix 3000 manufactured by Haake.

Next, the obtained kneaded product is molded into a 2 mm sheet and a sample for compression set measurement as specified in JIS K6301.
It was carried out in a ° C press. The tensile test was performed with a JIS No. 3 dumbbell at a tensile speed of 200 mm / min.

The results are shown in Table-3.

The heat resistance was evaluated by the rate of change from the normal value by placing the test piece in a gear oven adjusted to 130 ° C for 120 hours and then performing a tensile test.

The weather resistance was evaluated by putting a test piece in a sunshine weather meter adjusted to 83 ° C., taking out a sample after 300 hours, performing a tensile test, and evaluating the rate of change from a normal value.

Examples 1 to 5 are compositions according to the present application, whereas Comparative Example 1 is an example using a copolymer rubber containing no gel and having no functional group, which is more resistant to the composition of the present application. Poor impact resistance. In Comparative Examples 2 and 3, the content of the conjugated diene in the gel covalent copolymer rubber is out of the claimed range of the present application, but the impact resistance after heat aging is inferior to the composition of the present application. Comparative Example 4 is a polyamide alone, but is also inferior in impact resistance to the composition of the present application. Examples 6 to 10 are the compositions of the present invention using a polyamide elastomer. Comparative Example 5 is compared with the claims of the present application,
Although the composition contains a large amount of rubber, it has poor mechanical strength. Comparative Example 6 is an example using a copolymer rubber that does not contain a gel and does not have a functional group, but is inferior in mechanical strength and compression set characteristics. Further, in Comparative Example 7, the content of the conjugated diene in the gel-containing copolymer rubber is outside the scope of the claims of the present application, and the heat resistance and the weather resistance are poor. Comparative Example 8 is a gel-free copolymer rubber,
Small elongation and poor heat aging resistance. Comparative Example 9 is a commercially available acrylonitrile-butadiene rubber JSRN230S (Nippon Synthetic Rubber Co., Ltd.) instead of the gel-containing copolymer rubber shown in the present application.
Made, 35% bound acrylonitrile, Mooney viscosity ML _{1 + 4}
(100 ° C.) = 56), the mechanical strength, compression set characteristics, heat resistance, and weather resistance are all inferior to those of the examples of the present application.

From the above, it is clear that the composition of the present application is a composition having excellent mechanical strength, compression set characteristics, impact resistance, heat resistance, and weather resistance.

[Effects of the Invention] The composition obtained by mixing the polyamide and the polyamide elastomer of the present invention with a specific copolymer rubber having a pre-crosslinked functional group has impact resistance, heat resistance, weather resistance and mechanical properties. It has excellent mechanical strength and compression set characteristics, and has excellent characteristics as an industrial material.

Claims (1)

[Claims] 1. X) 20 to 99% by weight of polyamide and / or polyamide elastomer, and Y) 80 to 1% by weight of a copolymer rubber having a composition represented by the following [I] and having a gel content of 20% by weight. A thermoplastic polymer composition comprising: [I] (A) a- (B) b- (C) c- (D) d-
(E) e However, although A to E and a to e are defined by the following, the bonding modes of the monomers A to E may be any. A: unsaturated nitrile B: conjugated diene C: α, β unsaturated carboxylic acid ester D: crosslinkable monomer E: having at least one selected from a carboxyl group, amino group, epoxy group and hydroxyl group as a functional group Monomer a: 10 to 50% by weight b: 5 to 50% by weight c: 10 to 85% by weight d: 0.1 to 10% by weight e: 0.1 to 20% by weight, and a + b + c + d + e = 100% by weight.