JP2024040599A - Resin composition, polyamide resin composition, and polyamide resin molded body - Google Patents

Abstract

To provide a resin composition, from which a polyamide resin composition having excellent strange noise preventing property, a strange noise preventing property under a high load, and impact resistance.SOLUTION: Provided is a resin composition (Y) comprising an ethylene-alkyl (meth)acrylate copolymer (L), a graft copolymer (M), and a maleic acid-modified styrenic block copolymer (N), wherein the (M) is a graft copolymer comprising an ethylene-alkyl (meth)acrylate copolymer (A) and a copolymer (B) comprising a structural units derived from one or more vinyl monomers (b) selected from the group consisting of alkyl methacrylate monomers (b-1), aromatic vinyl monomers (b-2), (meth)acrylonitrile monomers (b-3), and hydroxyalkyl (meth)acrylate monomers (b-4), and a mass ratio of the (A) and the (B), ((A)/(B)), is 50/50 to 98/2.SELECTED DRAWING: None

Description

The present invention relates to a resin composition, a polyamide resin composition, and a polyamide resin molded article obtained from the polyamide resin composition.

Polyamide resin is used as a material for automobile parts, electrical/electronic parts, and daily necessities due to its mechanical properties, heat resistance, and chemical resistance. In recent years, metal parts have been increasingly replaced by resins to improve productivity and prevent rust, and door hinges in particular are being replaced with polyamide resin parts from the viewpoint of rigidity. However, polyamide resin (molded product) tends to produce squeaks when polyamide resin members rub against each other, and has low impact resistance, so there is room for improvement when used in large door hinges that are subject to high loads. was there.

As a method for improving noise prevention properties of a polyamide resin composition, for example, Patent Document 1 discloses that a polyamide resin, an ethylene-(meth)acrylic acid alkyl ester copolymer, and an ethylene-(meth)acrylic acid alkyl ester copolymer are used. A graft copolymer consisting of a polymer and a copolymer containing constitutional units derived from a vinyl monomer, and a polyamide resin composition containing a styrenic block copolymer are disclosed.

JP2022-17648A

However, the polyamide resin composition specifically disclosed in Patent Document 1 had insufficient noise prevention properties and impact resistance under high loads.

In view of the above circumstances, an object of the present invention is to provide a resin composition from which a polyamide resin composition having excellent noise prevention properties, noise prevention properties under high loads, and impact resistance can be obtained.

Another object of the present invention is to provide the above-mentioned polyamide resin composition and polyamide resin molded article.

That is, the present invention provides a resin composition containing an ethylene-(meth)acrylic acid alkyl ester copolymer (L), a graft copolymer (M), and a maleic acid-modified styrenic block copolymer (N). Y) and
The graft copolymer (M) comprises an ethylene-(meth)acrylic acid alkyl ester copolymer (A), a (meth)acrylic acid alkyl ester monomer (b-1), and an aromatic vinyl monomer ( b-2), (meth)acrylonitrile monomer (b-3), and (meth)acrylic acid hydroxyalkyl ester monomer (b-4). b) A graft copolymer consisting of a copolymer (B) containing structural units derived from
A resin composition in which the mass ratio ((A)/(B)) of the ethylene-(meth)acrylic acid alkyl ester copolymer (A) and the copolymer (B) is 50/50 to 98/2. Regarding.

The present invention also relates to a polyamide resin composition containing the resin composition (Y) and a polyamide resin (X).

Furthermore, the present invention relates to a polyamide resin molded article obtained from the polyamide resin composition.

Although the mechanism of action of the resin composition of the present invention is partially unknown, it is estimated as follows. However, the present invention is not construed as being limited to this mechanism of action.

When members rub against each other, frictional vibrations generated by the stick-slip phenomenon, in which the contact surfaces repeatedly stick due to static friction and slip due to dynamic friction, are recognized as abnormal noises. The resin composition (Y) of the present invention comprises an ethylene-(meth)acrylic acid alkyl ester copolymer (L), a graft copolymer (M), and a maleic acid-modified styrenic block copolymer (N). include. The graft copolymer (M) improves the compatibility of the ethylene-(meth)acrylic acid alkyl ester copolymer (L) and the maleic acid-modified styrenic block copolymer (N), and the resin composition (Y ) is finely dispersed in the polyamide resin (X) to absorb vibrations and prevent abnormal noise. Furthermore, by including the maleic acid-modified styrenic block copolymer (N), the interfacial strength between the polyamide resin (X) and the resin composition (Y) is improved, and excellent impact resistance is exhibited.

<Resin composition (Y)>
The resin composition (Y) according to the present embodiment includes an ethylene-(meth)acrylic acid alkyl ester copolymer (L), a graft copolymer (M), and a maleic acid-modified styrene block copolymer described below. It is obtained by melt-kneading the polymer (N).

<Ethylene-(meth)acrylic acid alkyl ester copolymer (L)>
The ethylene-(meth)acrylic acid alkyl ester copolymer (L) of the present invention is a copolymer synthesized from ethylene and (meth)acrylic acid alkyl ester monomers. The ethylene-(meth)acrylic acid alkyl ester copolymer (L) may be used alone or in combination of two or more.

In the ethylene-(meth)acrylic acid alkyl ester copolymer (L), the (meth)acrylic acid alkyl ester monomer is limited to the type as long as it is a (meth)acrylate having an alkyl group at the molecular terminal. It can be used without.

Examples of the (meth)acrylic acid alkyl ester monomer include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. The (meth)acrylic acid alkyl ester monomers may be used alone or in combination of two or more types.

The ethylene-(meth)acrylic acid alkyl ester copolymer (L) may contain other monomers, if necessary. Examples of the other monomers include saturated carboxylic acid vinyl esters such as vinyl acetate, vinyl propionate, and vinyl butyrate. The other monomers may be used alone or in combination of two or more.

The ratio (content) of the structural unit derived from the (meth)acrylic acid alkyl ester monomer in the ethylene-(meth)acrylic acid alkyl ester copolymer (L) is determined from the viewpoint of improving noise reduction properties. , preferably 2% by mass or more, more preferably 5% by mass or more, and from the viewpoint of improving noise reduction properties and fluidity, preferably 40% by mass or less, and 35% by mass or less It is more preferable that The content of the (meth)acrylic acid alkyl ester monomer can be determined by determining the concentration of the (meth)acrylic acid alkyl ester monomer, for example, based on the absorbance at 1039 cm ⁻¹ determined by an infrared absorption spectrum, and the concentration of the (meth)acrylic acid alkyl ester monomer determined in advance by a nuclear magnetic resonance spectrum. It is determined from a calibration curve obtained by measuring the above absorbance using a predetermined standard sample.

The ethylene-(meth)acrylic acid alkyl ester copolymer (L) has a melt mass flow rate (hereinafter also referred to as MFR) of 0.2 from the viewpoint of improving fluidity and workability in the manufacturing process of the resin composition. -40 (g/10min) is preferable, and 0.4 - 30 (g/10min) is more preferable. Note that the MFR can be measured in accordance with JIS K6924-1 (1997 edition).

Regarding the ethylene-(meth)acrylic acid alkyl ester copolymer (L), commercially available products include, for example, "Lexpar A6200", "Lexpar A4250", and "Lexpar A3100" manufactured by Japan Polyethylene Co., Ltd. can be mentioned.

<Graft copolymer (M)>
The graft copolymer (M) comprises an ethylene-(meth)acrylic acid alkyl ester copolymer (A), a (meth)acrylic acid alkyl ester monomer (b-1), and an aromatic vinyl monomer ( b-2), (meth)acrylonitrile monomer (b-3), and (meth)acrylic acid hydroxyalkyl ester monomer (b-4). It is a graft copolymer consisting of a copolymer (B) containing structural units derived from b).

The ethylene-(meth)acrylic acid alkyl ester copolymer (A) is a copolymer synthesized from ethylene and a (meth)acrylic acid alkyl ester monomer. The ethylene-(meth)acrylic acid alkyl ester copolymer (L) can be used as the ethylene-(meth)acrylic acid alkyl ester copolymer (A). The ethylene-(meth)acrylic acid alkyl ester copolymer (A) may be used alone or in combination of two or more kinds.

The vinyl monomer (b) includes (meth)acrylic acid alkyl ester monomer (b-1), aromatic vinyl monomer (b-2), and (meth)acrylonitrile monomer (b-3). ), (meth)acrylic acid hydroxyalkyl ester monomer (b-4).

Examples of the (meth)acrylic acid alkyl ester monomer (b-1) include alkyl (meth)acrylates having a linear or branched alkyl group having 1 to 18 carbon atoms. The number of carbon atoms is preferably 1 to 6, more preferably 1 to 3. Examples of the (meth)acrylic acid alkyl ester monomer include methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, Examples include butyl methacrylate, propyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, and lauryl methacrylate. Among these, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate are preferred from the viewpoint of improving noise reduction characteristics. The (meth)acrylic acid alkyl ester monomer (b-1) may be used alone or in combination of two or more types.

Examples of the aromatic vinyl monomer (b-2) include styrene, α-methylstyrene, о-methylstyrene, m-methylstyrene, p-methylstyrene, and pt-butylstyrene. Among these, styrene and α-methylstyrene are preferred from the viewpoint of improving noise reduction characteristics. The aromatic vinyl monomer (b-2) may be used alone or in combination of two or more types.

Examples of the (meth)acrylonitrile monomer (b-3) include acrylonitrile and methacrylonitrile. Among these, acrylonitrile is preferred from the viewpoint of improving noise reduction characteristics. The (meth)acrylonitrile monomer (b-3) may be used alone or in combination of two or more types.

Examples of the (meth)acrylic acid hydroxyalkyl ester monomer (b-4) include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2,3-dihydroxypropyl methacrylate, and 2-hydroxy acrylate. Examples include ethyl, 4-hydroxybutyl acrylate, and hydroxybenzyl methacrylate. Among these, 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate are preferred from the viewpoint of improving noise reduction properties. The (meth)acrylic acid hydroxyalkyl ester monomer (b-4) may be used alone or in combination of two or more types.

As the vinyl monomer (b), other monomers than the above monomers can be used. Examples of the other monomers include amide group-containing monomers such as (meth)acrylamide and N,N-dimethyl(meth)acrylamide; carboxyl group-containing monomers such as (meth)acrylic acid; glycidyl ( Examples include epoxy group-containing monomers such as meth)acrylate; glycol monomers such as polyethylene glycol (meth)acrylate and polypropylene glycol (meth)acrylate. The other monomers may be used alone or in combination of two or more.

In the copolymer (B), the (meth)acrylic acid alkyl ester monomer (b-1), the aromatic vinyl monomer (b-2), and the (meth)acrylonitrile monomer (b- 3), and the total proportion of structural units derived from one or more monomers selected from the group consisting of (meth)acrylic acid hydroxyalkyl ester monomer (b-4) is 70% by mass or more. The content is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more.

In the copolymer (B), the combination of the monomers may be butyl acrylate and methyl methacrylate, styrene and (meth)acrylonitrile, or butyl acrylate, styrene, and 2-hydroxypropyl methacrylate. More preferred. In this case, the mass ratio of butyl acrylate and methyl methacrylate (butyl acrylate/methyl methacrylate) or the mass ratio of styrene and (meth)acrylonitrile (styrene/(meth)acrylonitrile) has a high noise prevention property. From the viewpoint of improvement, the ratio is preferably 50/50 to 90/10, and more preferably 60/40 to 80/20. In addition, in the above combination of butyl acrylate, styrene, and 2-hydroxypropyl methacrylate, butyl acrylate may account for 10 to 40% by mass of the total of butyl acrylate, styrene, and 2-hydroxypropyl methacrylate. Preferably, the amount of styrene is 10 to 40% by weight, and the amount of 2-hydroxypropyl methacrylate is preferably 10 to 40% by weight.

The mass ratio ((A)/(B)) of the ethylene-(meth)acrylic acid alkyl ester copolymer (A) and the copolymer (B) is 50/50 to 98/2. The mass ratio ((A)/(B)) is preferably from 60/40 to 95/5, more preferably from 70/30 to 90/10, from the viewpoint of improving noise prevention properties.

<Method for producing graft copolymer (M)>
The method for producing the graft copolymer (M) is not particularly limited, and known polymerization methods such as suspension polymerization, emulsion polymerization, solution polymerization, and bulk polymerization can be used. Among these, suspension polymerization is preferred. Further, there is no particular restriction on the grafting method, and known grafting methods such as radical polymerization, cationic polymerization, anionic living polymerization, and cationic living polymerization can be employed. Among these, the radical polymerization method is preferable, and in particular, from the viewpoint of industrially producing large quantities of graft copolymers efficiently, it is preferable to use a vinyl monomer having a peroxide bond (radically polymerizable organic peroxide). More preferred is the radical polymerization method.

The vinyl monomer having a peroxide bond (radically polymerizable organic peroxide) is not particularly limited in type as long as it is a monomer having a peroxy group and an ethylenically unsaturated group in the molecule. They can be used alone or in combination of two or more. Examples of the vinyl monomer having a peroxide bond include t-butylperoxy(meth)acryloyloxyethyl carbonate, t-amylperoxy(meth)acryloyloxyethyl carbonate, t-hexylperoxy(meth)acryloyloxyethyl carbonate, t-butylperoxy(meth)acryloyloxyethoxyethyl carbonate, t-hexylperoxy(meth)acryloyloxyethoxyethyl carbonate, t-butylperoxy(meth)allyl carbonate, t-amylperoxy(meth)allyl carbonate, t- Examples include hexylperoxy(meth)allyl carbonate, and among these, t-butylperoxymethacryloyloxyethyl carbonate is preferred.

The method for producing the graft copolymer includes a solution (ethylene-(meth)acrylic acid alkyl ester) in which the ethylene-(meth)acrylic acid alkyl ester copolymer (A) is suspended in a medium mainly composed of water. Copolymer (A) concentration: 10 to 30 parts by mass), a monomer serving as a constituent unit of the copolymer (B), the vinyl monomer having a peroxide bond, and a polymerization initiator are added. , in the ethylene-(meth)acrylic acid alkyl ester copolymer (A) (particles of the ethylene-(meth)acrylic acid alkyl ester copolymer (A)), the constituent units of the copolymer (B) and a step of impregnating and polymerizing a monomer, a vinyl monomer having a peroxide bond, and the polymerization initiator to obtain a precursor, and melt-kneading the precursor to produce a graft copolymer (M). This method includes the step of: In the step of obtaining the precursor, if necessary, a suspending agent (for example, polyvinyl alcohol) may be added in an amount of 0.1 to 100 parts by mass to 100 parts by mass of the ethylene-(meth)acrylic acid alkyl ester copolymer (A). About 1 part by mass may be used. In addition, during the above impregnation, a monomer serving as a constituent unit of the copolymer (B) and a vinyl monomer having the peroxide bond are added to the ethylene-(meth)acrylic acid alkyl ester copolymer (A). In order to sufficiently impregnate the polymer, polymerization initiator, etc., stirring may be performed while heating (for example, about 60 to 80° C.).

The polymerization initiator is not particularly limited as long as it generates radicals when heated, and examples thereof include organic peroxides, azo polymerization initiators, and the like. The polymerization initiators may be used alone or in combination of two or more types.

The polymerization initiator has a 10-hour half-life temperature (hereinafter also referred to as T10) of 40°C or higher, from the viewpoint of suppressing rapid decomposition of the polymerization initiator and suppressing the remaining of the polymerization initiator and the monomer components. The temperature is preferably 50°C or higher, more preferably 130°C or lower, more preferably 100°C or lower, and even more preferably 80°C or lower. The 10-hour half-life temperature (T10) is determined by thermally decomposing a solution in which the polymerization initiator is dissolved in benzene at a concentration of, for example, 0.05 to 0.1 mol/liter. It means the temperature at which the polymerization initiator reaches its half-life in 10 hours.

Examples of the polymerization initiator include t-butylperoxyneoheptanoate (T10=51°C), t-hexylperoxypivalate (T10=53°C), and t-butylperoxypivalate (T10=55°C). °C), di(3,5,5-trimethylhexanoyl) peroxide (T10 = 59 °C), dilauroyl peroxide (T10 = 62 °C), 1,1,3,3-tetramethylbutylperoxy-2 -Ethylhexanoate (T10=65°C), 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane (T10=66°C), t-hexylperoxy-2-ethylhexylhexane Noate (T10=70°C), di(4-methylbenzoyl) peroxide (T10=71°C), t-butylperoxy-2-ethylhexanoate (T10=72°C), benzoyl peroxide (T10= 74°C), t-hexylperoxyisopropyl monocarbonate (T10=95°C), t-butylperoxy-3,5,5-trimethylhexanoate (T10=97°C), t-butylperoxylaurate ( T10=98°C), t-butylperoxyisopropyl monocarbonate (T10=99°C), t-butylperoxy-2-ethylhexyl monocarbonate (T10=99°C), t-hexylperoxybenzoate (T10=99°C) ), 2,5-dimethyl-2,5-di(benzoylperoxy)hexane (T10=100°C), t-butylperoxyacetate (T10=102°C), 2,2-di(t-butylperoxy) ) butane (T10=103°C), t-butylperoxybenzoate (T10=104°C), n-butyl-4,4-di(t-butylperoxy)valerate (T10=105°C), di(2- t-Butylperoxyisopropyl)benzene (T10=119°C), dicumyl peroxide (T10=116°C), di-t-hexyl peroxide (T10=116°C), 2,5-dimethyl-2,5- Organic peroxides such as di(t-butylperoxy)hexane (T10=118°C), t-butylcumyl peroxide (T10=120°C), di-t-butyl peroxide (T10=124°C); 2 , 2-azobis(2,4-dimethylvaleronitrile) (T10=51°C), 2,2-azobis(isobutyronitrile) (T10=65°C), 2,2-azobis(2-methylbutyronitrile) ) (T10=67°C) and the like.

In the step of producing the precursor, the polymerization temperature cannot be determined unconditionally because it varies depending on the raw materials (in particular, the 10-hour half-life temperature of the polymerization initiator), but it is usually preferably 65° C. or higher, The temperature is more preferably 70°C or higher, more preferably 90°C or lower, and even more preferably 85°C or lower. In addition, the polymerization time cannot be determined unconditionally as it varies depending on the raw materials, reaction temperature, etc., but usually, from the viewpoint of increasing the yield of the target product, it is preferably 1.5 hours or more, and 2 hours or more. is more preferable, and it is preferably 6 hours or less, and more preferably 5 hours or less.

In the step of producing the precursor, the amount of the vinyl monomer having a peroxide bond is 0.5 parts by mass or more based on 100 parts by mass of the monomer having the copolymer (B) as a constituent unit. The amount is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and 6 parts by mass or less. It is more preferably less than parts by mass.

In the step of producing the precursor, the amount of the polymerization initiator is preferably 0.3 parts by mass or more, and 0.5 parts by mass based on 100 parts by mass of the monomer having the copolymer (B) as a constituent unit. It is more preferably at least 3 parts by mass, more preferably at most 3 parts by mass, and even more preferably at most 2 parts by mass.

Examples of the melt-kneading include a method of melting and kneading the precursor using a kneader such as a Banbury mixer, a kneader, a kneading extruder, a twin-screw extruder, or a roll. The number of times of kneading may be one or more times. The kneading time varies depending on the size of the kneader used, but is usually about 3 to 10 minutes. Further, the discharge temperature of the kneader is preferably 130 to 350°C, more preferably 150 to 250°C.

<Maleic acid-modified styrenic block copolymer (N)>
The maleic acid-modified styrenic block copolymer (N) of the present invention is a styrenic block copolymer containing a polymer block D mainly composed of polystyrene and a polymer block E mainly composed of a conjugated diene compound, It has been modified by Examples of the styrenic block copolymers include block copolymers having structures such as DE, DE-D, ED-ED, and DE-D-ED-D. It will be done. The styrenic block copolymer preferably has two or more polymer blocks D in the molecule from the viewpoint of mechanical strength and moldability. Furthermore, in the polymer block E, the bonding mode between the conjugated diene compounds is not particularly limited and is arbitrary. When there are two or more polymer blocks E in a molecule, these may have the same structure or different structures. The maleic acid-modified styrenic block copolymer (N) may be used alone or in combination of two or more types.

The maleic acid-modified styrenic block copolymer (N) has a structural unit derived from polystyrene with a proportion of 5 to 5 from the viewpoint of improving noise prevention properties, noise prevention properties under high loads, and impact resistance. It is preferably 65% by mass, more preferably 10 to 40% by mass.

The maleic acid-modified styrenic block copolymer (N) may be hydrogenated, and the hydrogenation rate (carbon and carbon divalent in the block copolymer of polystyrene and the conjugated diene compound before hydrogenation) may be hydrogenated. The ratio of the number of bonds that become carbon-carbon single bonds due to hydrogenation to the number of double bonds is not particularly limited, but is usually 50 mol% or more, preferably 70 mol% or more, It is preferably 90 mol% or more.

As the maleic acid-modified styrenic block copolymer (N), for example, a maleic anhydride-modified styrene-ethylene-butylene-styrene block copolymer (SEBS) is preferred from the viewpoint of improving noise prevention properties and impact resistance.

In the resin composition (Y), the content of the ethylene-(meth)acrylic acid alkyl ester copolymer (L) is preferably 20 to 80% by mass from the viewpoint of improving noise prevention properties. , more preferably 40% by mass or more, and more preferably 75% by mass or less.

In the resin composition (Y), the content of the graft copolymer (M) is preferably 0.5 to 20% by mass, and 1% by mass or more, from the viewpoint of improving noise prevention properties. It is more preferable that the amount is 15% by mass or less, and more preferably 15% by mass or less.

In the resin composition (Y), the content ratio of the maleic acid-modified styrenic block copolymer (N) is determined from the viewpoint of improving noise prevention properties, noise prevention properties under high loads, and impact resistance. It is preferably 15 to 70% by mass, more preferably 20% by mass or more, and even more preferably 55% by mass or less.

<Polyamide resin composition>
The polyamide resin composition according to this embodiment contains a polyamide resin (X) and a resin composition (Y).

The polyamide resin is a polymer having an amide bond (-NHCO-) in its main chain. The polyamide resin (X) is not limited to a specific type, but includes, for example, polycaprolactam (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), and polyhexamethylene. Sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecamethylene adipamide (nylon 116), polyundecalactam (nylon 11), polydodecalactam (nylon 12), polytrimethylhexane Methylene terephthalamide (nylon TMHT), polyhexamethylene isophthalamide (nylon 6I), polynonane methylene terephthalamide (9T), polyhexamethylene terephthalamide (6T), polybis(4-aminocyclohexyl)methanddecamide (nylon PACM12) , polybis(3-methyl-aminocyclohexyl)methandodecamide (nylon dimethyl PACM12), polymethaxylylene adipamide (nylon MXD6), polyundecamethylenehexahydroterephthalamide (nylon 11T(H)), and the like. The polyamide resin (X) may be used alone or in combination of two or more types. Among these, polycaprolactam (nylon 6) and polyhexamethylene adipamide (nylon 66) are preferably used.

Among the polyamide resins, commercially available products include, for example, "Zytel 103HSL" manufactured by DuPont, "Amilan CM1017" and "Amilan CM3001-N" manufactured by Toray Industries, Inc., and "Maranyl A125" manufactured by Unitika Co., Ltd. ” etc.

The amount of the resin composition (Y) is preferably 1 to 15 parts by weight based on 100 parts by weight of the polyamide resin (X). The resin composition (Y) is more preferably 2 parts by mass or more, more preferably 5 parts by mass, based on 100 parts by mass of the polyamide resin (X), from the viewpoint of improving noise prevention properties of the resin molded product. The amount is more preferably at least 13 parts by mass, more preferably at most 10 parts by mass, and even more preferably at most 10 parts by mass.

In addition, various compounding agents can be used in the polyamide resin composition of the present invention. Examples of compounding agents include ceramic fiber (CF), glass fiber, aramid fiber, potassium titanate fiber, crushed mineral fiber, silica fiber, alumina fiber, gypsum fiber, magnesium hydroxide fiber, silicon carbide fiber, zirconia fiber, etc. Fiber reinforcement materials; spherical silica, mica, wollastonite, calcium carbonate, kaolin, clay, bentonite, sericite, glass beads, glass flakes, alumina, calcium silicate, magnesium carbonate, talc, zinc oxide, titanium oxide, oxide Organic or inorganic fillers in various forms such as iron, graphite, carbon black, molybdenum disulfide, ultra-high density polyethylene; mineral oils, hydrocarbons, fatty acids, fatty acid esters, fatty acid amides, alcohols, metallic soaps, natural waxes, silicones, etc. lubricants; processing aids such as PTFE and acrylic; inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide; organic flame retardants such as halogen and phosphorus; engineering plastics such as polyacetal, polycarbonate, and polyphenylene ether. Antioxidants, ultraviolet inhibitors, light stabilizers, colorants, antistatic agents, crosslinking agents, dispersants, coupling agents, foaming agents, colorants, etc.

The polyamide resin composition of the present invention can be obtained by melt-kneading the polyamide resin (X), the resin composition (Y), and any of the various additives. Examples of the melt-kneading include a method of melting and kneading the precursor using a kneader such as a Banbury mixer, a kneader, a kneading extruder, a twin-screw extruder, or a roll. The number of times of kneading may be one or more times. The kneading time varies depending on the size of the kneader used, but is usually about 3 to 10 minutes. Further, the discharge temperature of the kneader is preferably 150 to 350°C, more preferably 200 to 300°C.

The polyamide resin molded article of the present invention is obtained by molding the polyamide resin composition into a predetermined shape. Molding methods include, but are not limited to, injection molding, extrusion molding, etc., and the heating temperature, pressure, time, etc. for molding can be set as appropriate. The polyamide resin molded article has excellent noise prevention properties, noise prevention properties under high loads, and impact resistance, so it can be used for electrical parts, electronic parts, mechanical parts, automobile parts, daily necessities, and the like.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.

<Example>
<Production of graft copolymer (M1)>
2,500 g of pure water was placed in a stainless steel autoclave with an internal volume of 5 L, and 2.5 g of polyvinyl alcohol was further dissolved therein as a suspending agent. In this, 800 g of ethylene-ethyl acrylate copolymer (A1) (trade name "Rexpar A4200", manufactured by Japan Polyethylene Co., Ltd.) was added as the ethylene-(meth)acrylic acid alkyl ester copolymer (A). and stir to disperse.

Furthermore, as a polymerization initiator, 5.1 g of di(3,5,5-trimethylhexanoyl) peroxide (manufactured by NOF Corporation, trade name "Perloyl 355", 10 hour half-life temperature = 59 ° C.), A vinyl monomer mixture consisting of 17.2 g of t-butylperoxymethacryloyloxyethyl carbonate (hereinafter also referred to as MEC), 240 g of butyl acrylate (hereinafter also referred to as BA) and 103 g of methyl methacrylate (hereinafter also referred to as MMA) A solution was prepared by dissolving the above, and this solution was poured into the above autoclave and stirred.

Next, the above autoclave was heated to 60 to 65°C and stirred for 3 hours to convert the radical polymerization initiator, t-butylperoxymethacryloyloxyethyl carbonate, butyl acrylate, and methyl methacrylate into ethylene-(meth)acrylic acid. It was impregnated into the acid alkyl ester copolymer (A). Subsequently, the temperature of the above autoclave was raised to 80 to 85°C, and the temperature was maintained for 7 hours to polymerize the ethylene-(meth) impregnated with the copolymer (poly(BA/MMA/MEC)) as a precursor. An ethyl acrylate copolymer composition) was obtained. The obtained precursor was melt-kneaded at 230° C. using a Laboplast Mill single-screw extruder (manufactured by Toyo Seiki Seisakusho Co., Ltd.) to cause a grafting reaction. Next, after obtaining a strand-like resin composition, it was cut into pellets to produce M1.

<Manufacture of M2 to M4, M'1 to M'2>
M2 to M4 and M'1 to M'2 were produced in the same manner as M1, except that the types of raw materials and their blending amounts were changed as shown in Table 1.

In Table 1, A1 is an ethylene-ethyl acrylate copolymer (manufactured by Japan Polyethylene Co., Ltd., trade name "Lexpar A4200", the proportion of structural units derived from ethyl acrylate is 20% by mass, and the MFR is 5 ( g/10min));
A2 is an ethylene-ethyl acrylate copolymer (manufactured by Japan Polyethylene Co., Ltd., trade name "Lexpar A3100", the proportion of structural units derived from ethyl acrylate is 10% by mass, and the MFR is 3 (g/10min) ;
BA is butyl acrylate;
MMA is methyl methacrylate;
St is styrene;
AN is acrylonitrile;
HPMA stands for 2-hydroxypropyl methacrylate;

<Manufacture of resin composition (Y1)>
As the ethylene-(meth)acrylic acid alkyl ester copolymer (L), 45 g of ethylene-ethyl acrylate copolymer (L1) (trade name "Lexpar A4200", manufactured by Japan Polyethylene Co., Ltd.) and 10 g of the above M1 were used. and, as the maleic acid-modified styrenic block copolymer (N), 45 g of maleic anhydride-modified styrene-ethylene-butylene-styrene (SEBS) block copolymer (trade name "Kraton FG1924", manufactured by Kraton Polymer Co., Ltd.) was dry blended. Thereafter, the mixture was melt-kneaded (extrusion temperature: 160 to 180°C) using a twin-screw extruder (PCM-30, manufactured by Ikegai). Next, after obtaining a strand-like resin composition, this was cut into pellets to obtain a resin composition (Y1).

<Manufacture of Y2 to Y6, Y'1 to Y'7>
It was produced in the same manner as resin composition (Y1) except that the types of raw materials and their blending amounts were changed as shown in Table 2.

In Table 2, L1 is an ethylene-ethyl acrylate copolymer (manufactured by Japan Polyethylene Co., Ltd., trade name "Lexpar A4200", the proportion of structural units derived from ethyl acrylate is 20% by mass, and the MFR is 5 ( g/10min));
L2 is an ethylene-ethyl acrylate copolymer (manufactured by Japan Polyethylene Co., Ltd., trade name "Lexpar A3100", the proportion of structural units derived from ethyl acrylate is 10% by mass, and the MFR is 3 (g/10min) );
N1 is a maleic anhydride-modified styrene-ethylene-butylene-styrene (SEBS) block copolymer (manufactured by Kraton Polymer Co., Ltd., trade name "Kraton FG1924");
N2 is a maleic anhydride-modified styrene-ethylene-butylene-styrene (SEBS) block copolymer (manufactured by Kraton Polymer Co., Ltd., trade name "Kraton FG1901");
N'1 is ); Styrene-ethylene-butylene-styrene (SEBS) block copolymer (manufactured by Kraton Polymer Co., Ltd., trade name "Kraton G1651");
N′2 represents an acid-modified polyethylene wax (manufactured by Clariant Chemicals Co., Ltd., trade name “LICOCENE PEMA4221”), which is a modified polyolefin wax.

<Example 1>
<Manufacture of polyamide resin composition>
As the polyamide resin (X), 100 g of nylon 66 (X1) (trade name "Amilan CM3001-N", manufactured by Toray Industries, Inc.), 10 g of the above resin composition (Y1), and a twin screw extruder (PCM-30) were used. (manufactured by Ikegai) and melt-kneaded (extrusion temperature: 250 to 280°C). Next, after obtaining a strand-shaped polyamide resin composition, this was cut to obtain a pellet-shaped polyamide resin composition.

<Evaluation of abnormal noise prevention>
The pellets obtained above were injection molded (barrel temperature: 280 to 290°C, mold temperature: 95°C) to produce evaluation test pieces (length: 60 mm x width: 100 mm x thickness: 2 mm). Next, the test piece (evaluation material) was cut out into a noise prevention test plate (55 mm x 80 mm x 2 mm), deburred, and left for 12 hours at a temperature of 25 ° C. and a humidity of 50% RH. . In addition, a plate (length: 50 mm x width: 25 mm x thickness: 2 mm) for a mating material was prepared.

The noise prevention property was measured by fixing the above-mentioned noise prevention test plate and the same material plate for the mating material to Ziegler's stick-slip measuring device SSP-04, load = 40N, speed = 1mm/s. The abnormal noise generation risk index was measured and evaluated when rubbed together under the following conditions. Note that the smaller the value of the abnormal noise generation risk index, the lower the risk of abnormal noise generation. The criteria for determining the abnormal noise occurrence risk index are as shown below.
Abnormal noise generation risk index 1 to 3: Low risk of abnormal noise generation Abnormal noise generation risk index 4 to 5: Slightly high risk of abnormal noise generation Risk index 6 to 10: High risk of abnormal noise generation

The polyamide resin molded article of the present invention was evaluated as good if it had an abnormal noise generation risk index of 3 or less in the above-mentioned noise prevention evaluation.

<Evaluation of noise prevention under high load>
When the above-mentioned abnormal noise prevention test plate and the same material plate for the mating material were fixed to Ziegler's stick-slip measuring device SSP-04 and rubbed together under the conditions of load = 80N and speed = 1mm/s. The abnormal noise generation risk index was measured and evaluated. Note that the criteria for determining the abnormal noise generation risk index are the same as those described above.

<Evaluation of impact resistance>
For impact resistance, impact values were determined in accordance with Charpy impact test JIS K 7111-1. An impact value of 5.0 kJ/m ² or more was considered a passing value.

<Examples 2 to 8, Comparative Examples 1 to 9>
<Manufacture of polyamide resin composition>
A polyamide resin composition was produced in the same manner as in Example 1, except that the types of raw materials and their blending amounts (parts by mass) were changed as shown in Tables 3 and 4.

Tables 3 and 4 show the results of evaluation according to the evaluation method described above using each of the raw materials obtained above and the polyamide resin composition of the comparative example.

In Table 4, X1 is polyamide resin nylon 66 (trade name "Amilan CM3001-N", manufactured by Toray Industries, Inc.);
X2 represents nylon 6 (manufactured by Toray Industries, Inc., trade name "Amilan CM1017"), which is a polyamide resin.

For the polyamide resin compositions of Examples 1 to 8, evaluation results satisfying target values were obtained for noise prevention properties, noise prevention properties under high loads, and impact resistance.

In Comparative Example 1, the mass ratio ((A)/(B)) of the ethylene-(meth)acrylic acid alkyl ester copolymer (A) and the copolymer (B) of the graft copolymer (M) was Since the ratio was 40/60, the ability to prevent noise under high loads was poor.

In Comparative Example 2, the mass ratio ((A)/(B)) of the ethylene-(meth)acrylic acid alkyl ester copolymer (A) and the copolymer (B) of the graft copolymer (M) was Since the ratio was 100/0, the noise prevention properties and the noise prevention properties under high loads were poor.

In Comparative Example 3, an unmodified styrene copolymer was used instead of a maleic acid-modified styrenic block copolymer (N), so the noise prevention properties, noise prevention properties under high loads, and impact resistance were inferior. Ta.

Comparative Example 4 used a modified polyolefin wax instead of the maleic-modified styrenic block copolymer (N), and therefore had poor noise prevention properties, noise prevention properties under high loads, and impact resistance.

Comparative Example 5 did not contain the maleic acid-modified styrenic block copolymer (N), and therefore had poor noise prevention properties, noise prevention properties under high loads, and impact resistance.

Comparative Example 6 did not contain the graft copolymer (M), and therefore had poor noise prevention properties, noise prevention properties under high loads, and impact resistance.

Comparative Example 7 did not contain the ethylene-(meth)acrylic acid alkyl ester copolymer (L) or the graft copolymer (M), so it had poor noise prevention properties and noise prevention properties under high loads. .

Since Comparative Examples 8 and 9 did not contain the resin composition (Y), they were inferior in noise prevention properties, noise prevention properties under high loads, and impact resistance.

Claims (5)

A resin composition (Y) containing an ethylene-(meth)acrylic acid alkyl ester copolymer (L), a graft copolymer (M), and a maleic acid-modified styrenic block copolymer (N),
The graft copolymer (M) comprises an ethylene-(meth)acrylic acid alkyl ester copolymer (A), a (meth)acrylic acid alkyl ester monomer (b-1), and an aromatic vinyl monomer ( b-2), (meth)acrylonitrile monomer (b-3), and (meth)acrylic acid hydroxyalkyl ester monomer (b-4). b) A graft copolymer consisting of a copolymer (B) containing structural units derived from
The ethylene-(meth)acrylic acid alkyl ester copolymer (A) and the copolymer (B) have a mass ratio ((A)/(B)) of 50/50 to 98/2. A resin composition. The ethylene-(meth)acrylic acid alkyl ester copolymer (L) is 20 to 80% by mass, the graft copolymer (M) is 0.5 to 20% by mass, and the maleic acid-modified styrene-based The resin composition according to claim 1, characterized in that the block copolymer (N) is 15 to 70% by mass. A polyamide resin composition comprising the resin composition according to claim 1 or 2 and a polyamide resin (X). The polyamide resin composition according to claim 3, wherein the resin composition is present in an amount of 1 to 15 parts by mass based on 100 parts by mass of the polyamide resin (X). A polyamide resin molded article obtained from the polyamide resin composition according to claim 4.