JPH0251941B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to aliphatic polyamides, certain modified polyolefins and poly(4-methylpentene-1)
The present invention relates to a polyamide resin composition which has excellent rigidity, heat resistance, and chemical resistance and is particularly suitable for use in underhood parts for automobiles. Recently, there has been a noticeable trend in the automobile industry to replace conventional metal parts with resin for purposes such as weight reduction, rust prevention, and sound insulation to improve fuel efficiency. Among these, polyamide resin has excellent heat resistance, oil resistance, moldability, and toughness, so it is used in automobile underhood parts such as cooling fans, radiator tank tops and bases,
Applications to various functional parts such as cylinder head covers, oil pans, gears, valves, brake piping tubes, fuel piping tubes, other exhaust gas system parts, and electrical system parts such as connectors are attracting attention. The basic characteristics required for materials for automotive underhood parts are high strength, rigidity, and excellent heat resistance, as well as good chemical resistance to hydrocarbon solvents, alcohol, and calcium chloride as a road antifreeze agent. Examples include being . The present inventors have mainly studied in detail the combination of polyamide and polyolefin, and have conducted intensive research on resin compositions suitable for use in automobile underhood parts. The present invention was achieved based on the discovery that the objective can be achieved. That is, the present invention provides (A) aliphatic polyamide 40-95
Provided is a polyamide resin composition comprising (B) 2 to 30% by weight of a modified ethylene polymer and/or modified propylene polymer and (C) 5 to 60% by weight of poly(4-methylpentene-1). It is something to do. The present invention is characterized in that the high melting point and crystallinity of each component are effectively reflected in the heat resistance and chemical resistance, and a resin composition for automobile underhood parts with extremely high practical value can be obtained. (A) Aliphatic polyamide used in the present invention is polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecaneamide (nylon 11), polydodecanamide (nylon 12), copolyamides containing these as main components, and mixed polyamides. Among them, nylon 6 and nylon 66 are useful. The relative viscosity of the aliphatic polyamide used here is preferably within the range of 2.0 to 4.5. The modified ethylene polymer and/or modified propylene polymer (B) used in the present invention has ethylene and/or propylene as a main component, and has carboxylic acid groups and carboxylic acid groups represented by the following formulas () to (). A monomer component having at least one functional group selected from a metal base, a carboxylic acid ester group, an acid anhydride group, an epoxy group, an acid amide group, and an imide group (hereinafter referred to as a functional group-containing component) was introduced. means a polymer. Here, R ₁ to _{R 4} represent a hydrogen atom or an organic group, and M represents a metal ion having a valence of 1 to 3. Examples of functional group-containing components include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methylfumaric acid, mesaconic acid, citraconic acid, glutaconic acid, methyl hydrogen maleate, and itaconic acid. Methyl oxyhydrogen, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate,
Hydroxyethyl acrylate, methyl methacrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate, sodium methacrylate, potassium methacrylate, methacrylic acid Magnesium, zinc methacrylate, sodium acrylate, magnesium acrylate, zinc acrylate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo-[2,2,1]-5-heptene-
2,3-dicarboxylic acid, endobicyclo-[2,
α,β-unsaturated carboxylic acid derivatives such as 2,1]-5-heptene-2,3-dicarboxylic anhydride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, vinyl glycidyl ether, vinyl acetate, acrylamide; The α,β-unsaturated carboxylic acids or their anhydrides described herein include ammonia, methylamine, ethylamine, butylamine, hexylamine, dodecylamine, oleylamine, stearylamine, cyclohexylamine, benzylamine, aniline, naphthylamine, dimethylamine, Diethylamine, methylethylamine, dibutylamine, distearylamine, dicyclohexylamine, ethylcyclohexylamine, methylaniline, phenylnaphthylamine, melamine, ethanolamine, 3-amino-1-propanol, diethanolamine, morpholine, α-amino-1
-Addition of pyrrolidone, α-amino-ε-caprolactam, α-monomethylamino-ε-caprolactam, α-monoethylamino-ε-caprolactam, α-monobenzylamino-ε-caprolactam, nylon 6 oligomer with terminal amino group, etc. The resulting N-substituted amide compound, N
-Substituted imide compounds, etc. That is, R ₁ to _{R 4} in the formulas (), (), and () represent a hydrogen atom or an aliphatic, alicyclic, or aromatic residue having 1 to 30 carbon atoms, and M in the formula () represents sodium, Potassium, magnesium, zinc and aluminum are preferred. These functional group-containing components can be introduced by copolymerizing them with ethylene, propylene, etc., or by grafting them into polyolefins. The amount of the functional group-containing component introduced is suitably within the range of 0.001 to 10 mol%, preferably 0.01 to 5 mol%, based on the total components. If the content of the functional group-containing component is less than 0.001 mol%, the effect of improving the compatibilization of polyamide and poly(4-methylpentene-1) will be insufficient, and a composition exhibiting an intimately mixed state will not be obtained, which is not preferable. If the amount of the functional group-containing component exceeds 10 mol%, the stability of the polyolefin decreases and side reactions such as gelation tend to occur, which is not preferable. Specific examples of modified polyolefins useful in the present invention include ethylene/acrylic acid copolymers, ethylene/methacrylic acid/sodium methacrylate copolymers, ethylene/methacrylic acid/zinc methacrylate copolymers, and ethylene/acrylic acid copolymers. Methyl methacrylate/methacrylic acid/magnesium methacrylate copolymer, ethylene/isobutyl acrylate/methacrylic acid/zinc methacrylate copolymer, ethylene/methyl acrylate copolymer, ethylene/methyl acrylate/ acrylic acid copolymer,
Ethylene/ethyl acrylate copolymer, ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer, polyethylene-g-maleic anhydride copolymer (“g” represents grafting) , hereinafter the same), polypropylene-g-maleic anhydride copolymer, poly(ethylene/propylene)-g-maleic anhydride copolymer, poly(ethylene/propylene/1,
4-hexadiene)-g-maleic anhydride copolymer, poly(ethylene/propylene/dicyclopentadiene)-g-maleic anhydride copolymer, poly(ethylene/propylene/5-ethylidenenorbornene)-g-maleic anhydride Acid copolymer, poly(ethylene/propylene)-g-endobicyclo-
[2,2,1]-5-heptene-2,3-dicarboxylic anhydride copolymer, poly(ethylene/methacrylic acid/zinc methacrylate)-g-average degree of polymerization 10
Nylon 6 oligomer copolymer of These include copolymers to which caprolactam is added, and particularly preferred are modified polymers in which maleic anhydride or its amide or imide derivatives are grafted onto polyethylene or polypropylene. The degree of polymerization of these modified polymers is not particularly limited and can be arbitrarily selected from those having a melt index generally within the range of 0.05 to 50 g/10 minutes, preferably 0.1 to 30 g/10 minutes. (C) Poly(4-methylpentene-1) used in the present invention is a polymer whose main constituent is 4-methylpentene-1 obtained by dimerization of propylene. Particularly useful polymers in the present invention are homopolymers of 4-methylpentene-1 and 4-methylpentene-1 as a main component with small amounts of ethylene, propylene, butene-1, hexene-1, isobutylene,
Polymers obtained by copolymerizing or graft copolymerizing styrene, butadiene, or the above functional group-containing components can also be included. This poly(4-methylpentene-
There is no limit to the degree of polymerization in 1), and the melt index is usually 0.05 to 100 g/10 minutes, preferably 0.1.
You can choose anything within the range of ~50g/10 minutes. The polyamide resin composition of the present invention comprises (A) 40 to 95% by weight, preferably 45 to 90% by weight of aliphatic polyamide;
(B) Modified ethylene polymer and/or modified propylene polymer 2 to 30% by weight, preferably 5 to 25% by weight
Weight% and (C) poly(4-methylpentene-1)
It is constituted by blending 5 to 60% by weight, preferably 10 to 55% by weight. Polyamide and poly(4)
-Methylpentene-1) If the blending ratio is outside the above range, the advantages of each will become noticeable and will not be expressed, which is not preferable. Modified ethylene polymers and/or modified propylene polymers are originally added to improve the compatibility between polyamide and poly(4-methylpentene-1), and if the amount is less than 2% by weight, This is undesirable because the compatibilizing effect is reduced and a composition in an intimately mixed state cannot be obtained.On the other hand, if the amount exceeds 30% by weight, the characteristics of modified ethylene polymer or modified propylene polymer will strongly appear. It deviates from the intended purpose. The resin composition of the present invention may contain other ingredients, such as pigments, as long as they do not impair its moldability and physical properties.
Introducing dyes, reinforcing materials, fillers, heat resistant agents, antioxidants, weathering agents, lubricants, crystal nucleating agents, anti-blocking agents, mold release agents, plasticizers, flame retardants, antistatic agents, and other polymers. can do. It is especially important to add reinforcing materials and fillers, such as fibrous or powdered materials such as glass fiber, asbestos fiber, carbon fiber, graphite fiber, wollastenite, talc, calcium carbonate, mica, clay, potassium titanate whiskers, and glass beads. A reinforcing material may be added. The method for producing the resin composition of the present invention is not particularly limited.
Polyamide, modified polyolefin and poly(4
-Methylpentene-1) The most common method is to feed the three components simultaneously or with or without premixing each of the two components into a single-screw or multi-screw extruder and melt-knead them. By subjecting the resin composition of the present invention to molding methods used for ordinary thermoplastic resins such as injection molding, extrusion molding, blow molding, and compression molding, molded products with well-balanced mechanical properties can be obtained. These molded products are useful as various automobile parts, mechanical parts, electrical/electronic parts, general miscellaneous goods, etc. The present invention will be explained in more detail with reference to Examples below. The characteristics of the polymers and molded articles described in Examples and Comparative Examples were evaluated by the following method. (1) Relative viscosity of polyamide: JIS K6810 (2) Melt index: JIS K7210 (3) Tensile properties: ASTM D638 (4) Bending properties: ASTM D790 (5) Izot impact strength: ASTM D256 (6) Heat distortion temperature :ASTM D648 (7) Metal halide resistance test: Injection molded test piece
After being immersed in boiling water at 100℃ for 24 hours, it was left in a gear oven at 110℃ and sprayed with 50% calcium chloride solution in the form of water droplets every hour.
The number of cycles until cracks appeared in the molded product was measured. (8) Chemical resistance: A test piece with a thickness of 3 mm was immersed in ethanol and toluene, and the weight increase rate was determined after 10 days at 23°C. Example 1 Melt polymerization of ε-caprolactam to determine relative viscosity
2.75 nylon 6 was prepared. A modified ethylene polymer (melt indylamide) into which 1.1 mol% of maleic anhydride was grafted was obtained by adding maleic anhydride and a small amount of di-t-butyl peroxide to polyethylene and kneading at 200°C using an extruder. 2.5 g/10 minutes) was prepared. Polymerization of 4-methylpentene-1 obtained by dimerization of propylene using a Ziegler catalyst results in a melt index of 20.
Poly(4-methylpentene-1) was prepared at g/10 min. After premixing 60% by weight of nylon 6 pellets, 10% by weight of polyethylene-g-maleic anhydride copolymer and 30% by weight of poly(4-methylpentene-1), the mixture was heated at 260°C using an extruder with a diameter of 65 mm. The mixture was melt-kneaded and pelletized. After vacuum drying the pellets, the cylinder temperature is 250℃ using an injection molding machine.
℃ and a mold temperature of 80℃ to form test pieces for measuring various physical properties, and the physical properties of the test pieces obtained were evaluated as shown in Table 1, indicating that it is a material with extremely high practical value. I understood. Comparative Example 1 When the calcium chloride resistance of the nylon 6 test piece used in Example 1 was evaluated, countless cracks were generated on the entire surface of the test piece after just the first cycle. Comparative Example 2 Poly(4-methylpentene-
1) The Izotsu impact strength of the molded test piece is 2Kg.
It had cm/cm notches and was an extremely brittle material. Comparative Example 3 20% by weight of nylon 6 pellets used in Example 1, polyethylene-g-maleic anhydride copolymer
60% by weight and poly(4-methylpentene-1)
After mixing 20% by weight, the heat distortion temperature of the test piece obtained by melt-kneading and injection molding in the same manner as in Example 1 was 95%.
℃, and lacked heat resistance. Examples 2 to 10 The same operations as in Example 1 were carried out by changing the type and blending amount of aliphatic polyamide, modified ethylene polymer and/or modified propylene polymer, and poly(4-methylpentene-1). The physical properties of the obtained test piece were measured, and the results shown in Table 1 were obtained. Example 11 Nylon 66 and polypropylene obtained in Example 2
Nippon Glass Fiber Co., Ltd. chopped strand glass fiber (single fiber diameter: 13μ, fiber length: 3mm) was added to 100 parts by weight of a composition consisting of g-maleic anhydride copolymer and poly(4-methylpentene-1). ) was melted and kneaded at 280°C, and then molded into a test piece for measuring physical properties using an injection molding machine at a cylinder temperature of 275°C and a mold temperature of 90°C. The physical properties of the test piece obtained here were as follows. Tensile strength: 1460Kg/ ^cm2 Bending strength: 2600Kg/ ^cm2 Flexural modulus: 86500Kg/cm2 Izo impact strength: 11Kg・cm/cm ^notch Heat distortion temperature (18.6Kg/ ^cm2 ): 210℃

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Claims (1)

[Claims] 1 (A) 40 to 95% by weight of aliphatic polyamide, (B) 2 to 30% by weight of modified ethylene polymer and/or modified propylene polymer, and (C) 5 to 60% of poly(4-methylpentene-1) A polyamide resin composition consisting of % by weight.