WO2022138269A1 - Additive for polyamide resins, and polyamide resin composition - Google Patents

Abstract

An additive for polyamide resins that includes a first polymer. The first polymer includes, as constituent monomers, (i) a carboxyl group–containing vinyl monomer and (ii) a (meth)acrylic acid ester monomer and/or an aromatic vinyl monomer, and the weight average molecular weight of the first polymer is 2,000–25,000. The additive for polyamide resins may also include a second polymer that has a weight average molecular weight of at least 100,000.

Description

Polyamide resin additives and polyamide resin compositions

The present invention relates to an additive for a polyamide resin and a polyamide resin composition containing the additive.

Polyamide resins such as nylon-6, nylon-6,6, and nylon-12 have excellent physical properties such as heat resistance and abrasion resistance, and are also excellent against hydrocarbon solvents such as gasoline and oil. Because of its resistance, it is applied to various molding applications such as mechanical parts, automobile parts, and electrical / electronic parts.

However, the polyamide resin has the property that the melt viscosity and melt tension significantly decrease in the temperature range above the melting point. Therefore, there may be a problem that molding becomes difficult when applied to a melt processing method carried out in a temperature region above the melting point, such as blow molding, extrusion molding, and foam molding. Specifically, there may be a problem that the wall thickness of the molded product becomes non-uniform due to drawdown during blow molding or extrusion molding, and there may be a problem that cells become non-uniform during foam molding.

In Patent Document 1, in order to increase the melt viscosity of the polyamide resin, 100 weights of polymer particles (B-1) having a glass transition temperature of 60 ° C. or higher and a volume average particle diameter in the range of 50 to 500 μm and having reactivity are reactive. It is described that a thickener (B) coated with 0.5 to 30 parts by weight of polymer particles (B-2) having a volume average particle diameter of 0.01 to 0.5 μm is added to the polyamide resin. Has been done. In the examples, a monomer having an epoxy group (glycidyl metaclelite) is used in the production of the polymer particles (B-1), so that the polymer particles (B-1) have an epoxy group. Further, the weight average molecular weight thereof is disclosed as 52,000 to 67,000.

Although Patent Document 2 does not describe the melt viscosity, 80 to 99 parts by weight of the core-shell polymer and 1 to 20 copolymers of alkyl (meth) acrylate and unsaturated carboxylic acid are used as impact resistance improving agents for polyamide resins. It is described that the weight part is used together. There is no disclosure regarding the molecular weight of the copolymer.

Japanese Unexamined Patent Publication No. 2007-31607 Japanese Unexamined Patent Publication No. 63-61013

As described above, the polyamide resin is required to improve the moldability at the time of melt processing. At the same time, it is also required to improve the tensile properties of the obtained molded product.
However, the technique described in Patent Document 1 or 2 is insufficient to improve the moldability at the time of melt processing and further to improve the tensile properties of the molded product.

In view of the above situation, the present invention is an additive for a polyamide resin and an additive thereof, which can improve the moldability of a polyamide resin during melt processing and can improve the tensile properties of a molded product containing the polyamide resin. It is an object of the present invention to provide a polyamide resin composition containing the above.

By blending a copolymer containing a specific constituent monomer and having an average molecular weight within a specific range into the polyamide resin, the present inventors can improve the moldability of the polyamide resin during melt processing, and further obtain it. We have found that the tensile properties of the molded product are improved, and have reached the present invention.

That is, the present invention is an additive for a polyamide resin containing a first polymer, wherein the first polymer is (i) a carboxyl group-containing vinyl monomer as a constituent monomer, and
(Ii) (meth) acrylic acid ester monomer and / or aromatic vinyl monomer,
The first polymer is an additive for a polyamide resin having a weight average molecular weight of 2,000 to 25,000.
Preferably, the carboxyl group-containing vinyl monomer accounts for 15% by weight or more and 50% by weight or less of the 100% by weight of the first polymer.
Preferably, the first polymer is a copolymer containing (i) a carboxyl group-containing vinyl monomer and (ii) (meth) acrylic acid ester monomer as constituent monomers.
Preferably, it further comprises a second polymer having a weight average molecular weight of 100,000 or more.
Preferably, the first polymer constitutes the particles and at least a portion of the second copolymer is located outside the particles.
Preferably, the second polymer is a polymer containing a methacrylic acid ester monomer and / or an aromatic vinyl monomer as a constituent monomer.
Preferably, the total of the methacrylic acid ester monomer and the aromatic vinyl monomer accounts for 80% by weight or more and 100% by weight or less of the 100% by weight of the second polymer.
Preferably, the first polymer and / or the second polymer is a non-rubber-like polymer.
Preferably, the first polymer and the second polymer are non-rubbery polymers, respectively, the first polymer constitutes particles, and at least a part of the second polymer is outside the particles. Is located in.
The present invention also relates to a modifier for a polyamide resin, which comprises the additive and an impact resistance improving agent. Preferably, the impact resistance improving agent is a core-shell type impact resistance improving agent. Preferably, the impact resistance improving agent is a polyolefin-based elastomer.
Further, the present invention contains the polyamide resin and the additive for the polyamide resin, and the ratio of the additive to 100% by weight of the total of the polyamide resin and the additive is 0.1 to 10% by weight. It also contains a polyamide resin and a modifier for the polyamide resin, and the modifier is based on 100% by weight of the total of the polyamide resin and the modifier. It also relates to a polyamide resin composition having a proportion of 1 to 40% by weight.
Preferably, the polyamide resin composition further contains a reinforcing material, and the ratio of the reinforcing material to 100% by weight of the total of the polyamide resin and the reinforcing material is 10 to 60% by weight.
Furthermore, the present invention also relates to a pellet or a molded product made of the polyamide resin composition.

According to the present invention, an additive for a polyamide resin capable of improving the moldability of the polyamide resin during melt processing and improving the tensile properties of a molded product containing the polyamide resin, and a polyamide containing the additive. A resin composition can be provided. According to the additive for a polyamide resin according to a preferred embodiment of the present invention, the fluidity of the polyamide resin at the time of melting can be lowered, and further, the melt viscosity or the melt tension of the polyamide resin can be increased. .. Further, the additive for a polyamide resin can be blended with a polyamide resin together with an impact resistance improving agent, whereby, in addition to the above-mentioned effects, the impact resistance improving effect of the impact resistance improving agent can be further enhanced. Can be done.

Hereinafter, embodiments of the present invention will be described in detail.

(Additive for polyamide resin)
The additive for the polyamide resin of the present embodiment contains at least the first polymer. Since the additive for a polyamide resin according to a preferred embodiment is excellent in granulation property at the time of producing the additive, it is preferable to contain a second polymer in addition to the first polymer. The additive for a polyamide resin is used by blending with a polyamide resin, and may be a molecular chain extender of the polyamide resin or an agent for improving the moldability of the polyamide resin during melt processing. Further, it may be an agent for improving the tensile properties of the polyamide resin-containing molded body.

(First polymer)
The first polymer is a copolymer containing a carboxyl group-containing vinyl monomer, a (meth) acrylic acid ester monomer and / or an aromatic vinyl monomer as a constituent monomer.

The first polymer has a carboxyl group derived from the carboxyl group-containing vinyl monomer. When the polyamide resin and the first polymer are mixed by melt kneading or the like, the carboxyl group of the first polymer may react with the terminal amino group of the polyamide resin. By this reaction, the molecular chain of the polyamide resin is extended, and in addition, a branched structure can be introduced into the polyamide resin. It is presumed that the above mechanism improves the moldability of the polyamide resin during melt processing and further improves the tensile properties of the obtained molded product. On the other hand, as shown in a later comparative example, when a polymer having an epoxy group instead of a carboxyl group was blended in the polyamide resin, the effect of improving the moldability of the polyamide resin during melt processing was not sufficient.

The carboxyl group-containing vinyl monomer is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. One of these may be used, or two or more thereof may be used in combination. Of these, acrylic acid and / or methacrylic acid is preferable, and methacrylic acid is more preferable.

The content of the carboxyl group-containing vinyl monomer can be appropriately set from the viewpoints of the effect of improving moldability during melt processing, the effect of improving the tensile properties of the molded body, productivity, and the like. The content may be, for example, 10% by weight or more, more preferably 15% by weight or more, and more preferably 20% by weight or more, based on 100% by weight of the first polymer. In this range, the effect of improving moldability during melt processing is particularly excellent. However, if the content of the carboxyl group-containing vinyl monomer is too large, the water content of the first polymer becomes high and post-treatment during production becomes complicated. Therefore, the content is 50% by weight or less. It is preferably 45% by weight or less, and more preferably 45% by weight or less.

From the viewpoint of productivity, the first polymer is one of a (meth) acrylic acid ester monomer and an aromatic vinyl monomer, in addition to a carboxyl group-containing vinyl monomer, as a constituent monomer. Or both are included. The first polymer contains a (meth) acrylic acid ester monomer because it is excellent in the effect of improving the moldability of the polyamide resin during melt processing and the effect of improving the tensile properties of the molded product. Is preferable.

The (meth) acrylic acid ester monomer is not particularly limited, and for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like. (Meta) Acrylic Acid Alkyl Ester; Examples thereof include (meth) acrylic acid hydroxyalkyl ester such as (meth) acrylate 2-hydroxyethyl. Of these, a (meth) acrylic acid alkyl ester monomer is preferable, a (meth) acrylic acid alkyl ester monomer having an alkyl group having 1 to 4 carbon atoms is more preferable, and methyl methacrylate is particularly preferable.

The aromatic vinyl monomer is not particularly limited, and examples thereof include styrene, α-methylstyrene, and p-methylstyrene. Of these, styrene is preferable.

The larger the molecular weight of the first polymer is, the more preferable it is from the viewpoint of the effect of improving the formability at the time of melt processing and the effect of improving the tensile properties of the molded body. Specifically, the weight average molecular weight of the first polymer is The polystyrene-equivalent molecular weight measured by gel permeation chromatography (GPC) is preferably in the range of 2,000 to 25,000. If the weight average molecular weight is less than 2,000, the thermal stability of the polymer may be insufficient. If the weight average molecular weight exceeds 25,000, the stability of the latex may decrease during the production of the polymer, and it may be difficult to efficiently produce the latex. A polymer having a weight average molecular weight of 25,000 or less can be suitably produced by using a chain transfer agent at the time of polymerization.

The first polymer is preferably a non-rubbery polymer. The non-rubber-like polymer means a polymer having no crosslinked structure between the molecular chains of the polymer. Since the first polymer is a non-rubber-like polymer, the reaction between the carboxyl group of the first polymer and the terminal amino group of the polyamide resin proceeds more efficiently, and the effect of improving moldability during melt processing and the effect of improving moldability, and The effect of improving the tensile properties of the molded product is likely to be achieved.

(Second polymer)
The second polymer is an arbitrary component capable of improving the granulation property at the time of production. Since the first polymer has a small molecular weight, if it is powdered by itself, it becomes a fine powder, which may be difficult to handle. Therefore, in order to obtain the first polymer as a powder having an appropriate particle size that is easy to handle, the first polymer is produced together with the second polymer having a large molecular weight, and the first polymer is made into the second double. It is desirable to isolate with coalescence. Furthermore, the presence of the second polymer improves the dispersibility of the first polymer in the polyamide resin, efficiently promotes the reaction between the polyamide resin and the first polymer, and makes the polyamide resin. It becomes possible to further improve the moldability at the time of melt processing.

From the viewpoint of improving the granulation property, the weight average molecular weight of the second polymer is 100,000 or more in terms of polystyrene-equivalent molecular weight measured by GPC. It is preferably 150,000 or more, and more preferably 180,000 or more. The upper limit is not particularly limited, but is preferably 1,000,000 or less, more preferably 700,000 or less, still more preferably 500,000 or less.

The monomer constituting the second polymer is not particularly limited, but preferably contains a methacrylic acid ester monomer and / or an aromatic vinyl monomer. From the viewpoint of the effect of improving moldability during melt processing and the effect of improving the tensile properties of the molded product, it is more preferable to contain an aromatic vinyl monomer. Further, from the viewpoint of polymerization conversion and granulation property, it is more preferable to contain a methacrylic acid ester monomer.

The methacrylic acid ester monomer is not particularly limited, and is, for example, an alkyl methacrylate ester such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, or 2-ethylhexyl methacrylate; and methacrylic acid such as 2-hydroxyethyl methacrylate. Examples thereof include hydroxyalkyl esters. Of these, the methacrylic acid alkyl ester monomer is preferable, the methacrylic acid alkyl ester monomer having 1 to 4 carbon atoms in the alkyl group is more preferable, and methyl methacrylate is particularly preferable.

The aromatic vinyl monomer is not particularly limited, and examples thereof include styrene, α-methylstyrene, and p-methylstyrene. Of these, styrene is preferable.

The total content of the methacrylic acid ester monomer and the aromatic vinyl monomer is preferably 80% by weight or more and 100% by weight or less, and 82% by weight or more and 99% by weight, out of 100% by weight of the second polymer. By weight% or less is more preferable, and 84% by weight or more and 98% by weight or less is further preferable.

From the viewpoint of improving granulation property, the second polymer preferably contains an acrylic acid ester monomer in addition to the methacrylic acid ester monomer and / or the aromatic vinyl monomer.

The acrylic acid ester monomer is not particularly limited, and for example, acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; acrylic acids such as 2-hydroxyethyl acrylate. Hydroxyalkyl esters and the like can be mentioned. Of these, an acrylic acid alkyl ester monomer is preferable, an acrylic acid alkyl ester monomer having an alkyl group having 1 to 4 carbon atoms is more preferable, and butyl acrylate is particularly preferable.

From the viewpoint of improving granulation property, the content of the acrylic acid ester monomer is preferably 0% by weight or more and 20% by weight or less, and 1% by weight or more and 18% by weight or less, out of 100% by weight of the second polymer. More preferably, it is 2% by weight or less, and further preferably 2% by weight or more and 16% by weight or less.

The second polymer is preferably a non-rubbery polymer. Since the second polymer is a non-rubber-like polymer, the reaction between the carboxyl group of the first polymer and the terminal amino group of the polyamide resin proceeds more efficiently, and the effect of improving moldability during melt processing and the effect of improving moldability, and It becomes easy to achieve the effect of improving the tensile properties of the molded product.

The additive for a polyamide resin according to a preferred embodiment may be any one containing the first polymer and the second polymer, and the relationship between the two polymers is not particularly limited, but from the viewpoint of improving the granulation property, the relationship between the two polymers is not particularly limited. It is preferable that the first polymer constitutes the particles and at least a part of the second polymer is located outside the particles. At least a part of the second polymer may cover the outer surface of the particles. Further, a part of the second polymer may be located outside the particles, and the rest may be impregnated inside the particles.
Further, it is preferable that the first polymer and the second polymer are not bonded by a chemical bond. In this case, it is considered that the first polymer and the second polymer are separated from each other in the polyamide resin which is a matrix by kneading the additive with the polyamide resin.

The additive for a polyamide resin according to the present embodiment is used by blending with a polyamide resin, and has an effect of improving the moldability at the time of melt processing of the polyamide resin and an effect of improving the tensile property of the polyamide resin-containing molded body. Can play. The blending amount of the additive with respect to the polyamide resin can be appropriately set, but the ratio of the additive to the total of the polyamide resin and the additive is preferably 0.1% by weight or more and 10% by weight or less. When the ratio of the additive is within the above range, the effect of improving the moldability at the time of melt processing and the effect of improving the tensile properties of the molded product can be suitably exhibited while maintaining the physical characteristics peculiar to the polyamide resin. The ratio is more preferably 0.2 to 8% by weight, still more preferably 0.3 to 5% by weight. Further, it is particularly preferable that the ratio is 1.5% by weight or more because the effect of improving the tensile properties of the molded product is great.

(Manufacturing method of additives for polyamide resin)
The method for producing the additive for a polyamide resin can be a conventional polymerization method and is not particularly limited. For example, bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and the like can be adopted, but emulsion polymerization is preferable. When producing the first polymer, it is preferable to carry out the polymerization in the presence of a chain transfer agent in order to control the molecular weight. When the first polymer and the second polymer are continuously produced, first, a latex of the first polymer is produced by emulsion polymerization, and the latex is used with a monomer component for the second polymer and polymerization. The monomer component may be polymerized by adding an initiator or the like.

The chain transfer agent that can be used in the production of the first polymer is not particularly limited, but is 1 such as n-butyl mercaptan, n-octyl mercaptan, n-hexadecyl mercaptan, n-dodecyl mercaptan, n-tetradecyl mercaptan, and the like. Secondary mercaptan-based chain transfer agents such as grade mercaptan-based chain transfer agents, sec-butyl mercaptan, sec-dodecyl mercaptan, tertiary mercaptan-based chain transfer agents such as t-dodecyl mercaptan, and mercaptan compounds, 2-ethylhexylthioglycol. Rate, ethylene glycol dithioglycolate, trimethylolpropanetris (thioglycolate), thioglycolic acid esters such as pentaerythritol tetrakis (thioglycolate), thiophenols, tetraethylthium disulfide, pentanphenylethane, achlorine, metachlorine, allyl. Examples thereof include alcohol, carbon tetrachloride, ethylene bromide, styrene oligomers such as α-methylstyrene dimer, and terpinolene. These may be used alone or in combination of two or more. The amount of the chain transfer agent used may be appropriately set according to the desired weight average molecular weight of the first polymer.

The emulsifier (dispersant) that can be used in emulsion polymerization is not particularly limited, and anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants and the like can be used. Further, a dispersant such as polyvinyl alcohol, alkyl-substituted cellulose, polyvinylpyrrolidone, and a polyacrylic acid derivative may be used.
Among the above emulsifiers, the anionic surfactant is not particularly limited, and examples thereof include the following compounds: potassium laurate, potassium coconut fatty acid, potassium myristate, potassium oleate, potassium oleate diethanolamine salt, sodium oleate. , Potassium palmitate, potassium stearate, sodium stearate, mixed fatty acid soda soap, semi-cured beef fatty acid soda soap, castor oil potash soap and other fatty acid soaps; sodium dodecyl sulfate, higher alcohol sodium sulfate, triethanolamine dodecyl sulfate, dodecyl Alkyl sulfates such as ammonium sulfate, polyoxyethylene alkyl ether sodium sulfate, polyoxyethylene alkyl ether sulfate triethanolamine, polyoxyethylene alkylphenyl ether sodium sulfate, 2-ethylhexyl sodium sulfate; alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate Sodium acid; sodium dialkyl sulfosuccinate such as di-2-ethylhexyl sulfosuccinate; sodium alkylnaphthalene sulfonate; sodium alkyldiphenyl ether disulfonate; potassium alkyl phosphate; phosphate ester salt such as polyoxyethylene lauryl ether sodium phosphate Sodium salt of naphthalene sulfonic acid formarin condensate; polycarboxylic acid type polymer anion; acyl (beef fat) sodium methyl taurate; acyl (palm) sodium methyl taurate; sodium cocoyl isethionate; α-sulfo fatty acid ester sodium salt ; Sodium amide ether sulfonate; Oleyl sarcosin; Sodium lauroyl sarcosin; Sodium loginate, etc.

The nonionic surfactant among the above emulsifiers is not particularly limited, and examples thereof include the following compounds: polyoxy such as polyoxyethylene nonylphenyl ether, polyoxyethylene oleyl ether, and polyoxyethylene lauryl ether. Polyoxyethylene sorbitan esters such as ethylenealkylallyl ethers or polyoxyethylene alkyl ethers, polyoxyethylene sorbitan monolaurates, polyoxyethylene sorbitan monostearates, polyethylene glucol monolaurates, polyethylene glucol monostearates, Polyoxyethylene fatty acid esters such as polyethylene glucol monooleate, oxyethylene / oxypropylene block copolymers, etc.

The cationic surfactant among the above emulsifiers is not particularly limited, and examples thereof include the following compounds: alkylamine salts such as coconatamine acetate, stearylamine acetate, octadecylamine acetate, and tetradecylamine acetate; Tertiary ammonium salts such as lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, cetyltrimethylammonium chloride, distearyldimethylammonium chloride, alkylbenzyldimethylammonium chloride, hexadecyltrimethylammonium chloride, and behenyltrimethylammonium chloride.

The amphoteric surfactant among the above emulsifiers is not particularly limited, and examples thereof include the following compounds: alkyl betaines such as lauryl betaine, stearyl betaine, and dimethyl lauryl betaine; sodium lauryl diaminoethyl glycine; amide betaine; imidazoline. Laurylcarboxymethyl hydroxyethyl imidazolinium betaine, etc.

These emulsifiers (dispersants) may be used alone or in combination of two or more.

When the emulsion polymerization method is adopted, a known polymerization initiator, that is, 2,2'-azobisisobutyronitrile, hydrogen peroxide, potassium persulfate, ammonium persulfate, etc., may be used as the pyrolysis initiator. can.

In addition, organic peroxides such as t-butylperoxyisopropyl carbonate, paramentanhydroperoxide, cumenehydroperoxide, dicumyl peroxide, t-butylhydroperoxide, di-t-butyl peroxide, and t-hexyl peroxide. Oxides; peroxides such as inorganic peroxides such as hydrogen peroxide, potassium persulfate, ammonium persulfate, and optionally sodium formaldehyde sulfoxylate, reducing agents such as glucose, and optionally iron sulfate (II). ) And the like, and if necessary, a chelating agent such as disodium ethylenediamine tetraacetate, and if necessary, a phosphorus-containing compound such as sodium pyrophosphate can be used in combination with a redox-type initiator.

When a redox-type initiator is used, polymerization can be carried out even at a low temperature at which the peroxide does not substantially undergo thermal decomposition, and the polymerization temperature can be set in a wide range, which is preferable. Of these, it is preferable to use organic peroxides such as cumene hydroperoxide, dicumyl peroxide, and t-butyl hydroperoxide as the redox-type initiator. The amount of the initiator used, and when the redox-type initiator is used, the amount of the reducing agent, transition metal salt, chelating agent, etc. used can be used within a known range. Further, when polymerizing a monomer having two or more radically polymerizable double bonds, a known chain transfer agent can be used in a known range. Additional surfactants can be used, but this is also in the known range.

As the solvent used in the emulsion polymerization, any solvent may be used as long as it stably promotes the emulsion polymerization, and for example, water or the like can be preferably used.

The temperature at the time of emulsion polymerization is not particularly limited as long as the emulsifier is uniformly dissolved in the solvent, but is, for example, 40 to 75 ° C, preferably 45 to 73 ° C, and more preferably 49 to 71 ° C.

When the additive for polyamide resin is produced by emulsification polymerization, for example, the latex of the additive and an acid such as hydrochloric acid, or divalent or higher such as calcium chloride, magnesium chloride, magnesium sulfate, aluminum chloride, calcium acetate, etc. After the additive is coagulated by mixing the metal salt of the above, the additive can be separated from the aqueous medium by heat-treating, dehydrating, washing and drying the additive according to a known method. The resulting additive is preferably washed with water and / or an organic solvent.

Further, an alcohol such as methanol, ethanol and propanol, and a water-soluble organic solvent such as acetone were added to the latex of the additive to precipitate the additive, and the additive was separated from the solvent by centrifugation, filtration or the like. Later, it can be dried and isolated. As another method, an organic solvent having a slight water solubility such as methyl ethyl ketone is added to the latex of the additive, the additive in the latex is extracted into the organic solvent layer, the organic solvent layer is separated, and then water or the like is used. And the method of precipitating the additive by mixing with the above can also be mentioned.

Further, the latex of the additive can be directly powdered by a spray drying method. The obtained powder is preferably washed with water and / or an organic solvent. Alternatively, calcium chloride, magnesium chloride, magnesium sulfate, aluminum chloride, etc. are added to the obtained powder as a solution such as an aqueous solution, and if necessary, re-dried to obtain the same effect as the above cleaning. Obtainable.

(Modifier for polyamide resin)
The modifier for a polyamide resin of the present embodiment includes the above-mentioned additive for a polyamide resin and an impact resistance improving agent. The impact resistance improving agent is not particularly limited and may be a conventionally known one. As a specific example, one or more selected from the group consisting of a core-shell type impact resistance improving agent, a polyolefin-based elastomer, a polyester elastomer, and a polyamide elastomer is desirable. Of these, a core-shell type impact strength improving agent or a polyolefin-based elastomer is preferable.

The core-shell type impact strength improving agent is composed of polymer particles which are graft copolymers. The polymer particles are composed of a shell layer and one or more core layers. The shell layer refers to a polymer layer located on the surface side of the polymer particles, and is also referred to as a graft layer. The core layer refers to a polymer layer located inside the polymer particles rather than the shell layer, and is composed of a rubber-like polymer. The core layer may be only one layer, or may be composed of two or more layers having different monomer compositions from each other. The shell layer covers the surface of the core layer, but is not limited to covering the entire surface of the core layer, and may cover at least a part of the surface of the core layer.

(Core layer)
The core layer is composed of a rubber-like polymer. The rubber-like polymer preferably contains at least one selected from the group consisting of natural rubber, diene-based rubber, acrylate-based rubber and polyorganosiloxane-based rubber, and preferably contains diene-based rubber, acrylate-based rubber and polyorganosiloxane. It is more preferable to contain one or more selected from the group consisting of rubbers.

(Diene rubber)
The diene-based rubber is an elastic body containing a constituent unit derived from a diene-based monomer as a constituent unit. Since the glass transition temperature of the obtained elastic body can be lowered, the effect of improving the impact resistance of the obtained polyamide resin composition on the molded body is high, and the raw material cost is low, the core layer is made of a diene rubber. Is more preferable, and a diene-based rubber is particularly preferable.

Examples of the diene-based monomer include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2-chloro-1,3-butadiene and the like. Only one kind of these diene-based monomers may be used, or two or more kinds thereof may be used in combination.

The diene-based rubber may further contain, as the structural unit, a structural unit derived from a vinyl-based monomer other than the diene-based monomer copolymerizable with the diene-based monomer.

Examples of the vinyl-based monomer (hereinafter, also referred to as vinyl-based monomer A) other than the diene-based monomer copolymerizable with the diene-based monomer include (a) styrene and α-methylstyrene. , Monochlorostyrene, Dichlorostyrene and other aromatic vinyl monomers; (b) Acrylic acid, Vinyl carboxylic acids such as methacrylic acid; (c) Ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate , (Meta) alkyl (meth) acrylates such as ethyl methacrylate and butyl methacrylate; (d) hydroxyl group-containing vinyl monomers such as 2-hydroxyethyl methacrylate and 4-hydroxybutyl acrylate; (e) glycidyl methacrylate. , 4-Hydroxybutyl acrylate glycidyl group-containing vinyl monomer such as glycidyl ether; (f) unsaturated nitrile-based monomer such as acrylonitrile and methacrylonitrile; (g) halogen such as vinyl chloride, vinyl bromide and chloroprene. Examples thereof include vinyl chlorides; (h) vinyl acetate; (i) alkenes such as ethylene, propylene, butylene and isobutylene. As the vinyl-based monomer A described above, only one type may be used, or two or more types may be used in combination.

The content of the structural unit derived from the vinyl-based monomer A in the diene-based rubber is not particularly limited. The diene-based rubber contains 50 to 100% by weight of the constituent unit derived from the diene-based monomer and 0 to 50% by weight of the constituent unit derived from the vinyl-based monomer A in 100% by weight of the constituent unit. Is preferable.

The diene-based rubber is a polyfunctional monomer such as diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, and 1,3-butylenedimethacrylate as a constituent unit. It may further contain a structural unit derived from. That is, these polyfunctional monomers may be used in the polymerization of the diene rubber.

As the diene rubber, butadiene rubber (polybutadiene rubber), styrene / butadiene copolymer rubber (poly (styrene / butadiene) rubber), poly (acrylonitrile / butadiene) rubber, butadiene / acrylic acid ester copolymer and the like are preferable. Can be mentioned. Butadiene rubber is an elastic body containing 50 to 100% by weight of a structural unit derived from 1,3-butadiene in 100% by weight of the structural unit.

The diene rubber is preferably a butadiene rubber containing 50 to 100% by weight of a structural unit derived from 1,3-butadiene and 0 to 50% by weight of a structural unit derived from vinyl-based monomer A. , 1,3-butadiene homopolymer containing 100% by weight of a structural unit derived from 1,3-butadiene is more preferable.

Since the glass transition temperature of the obtained elastic body can be lowered, the effect of improving the impact resistance of the obtained polyamide resin composition on the molded body is high, and the raw material cost is low, the core layer is made of butadiene rubber. It is more preferably contained, and it is particularly preferable that it is a butadiene rubber.

(Acrylate rubber)
The acrylate-based rubber is an elastic body containing a structural unit derived from a (meth) acrylate-based monomer as a structural unit.

Examples of the (meth) acrylate-based monomer include (a) methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylate 2. -Alkyl (meth) acrylate having an alkyl group having 1 to 22 carbon atoms, such as ethylhexyl, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate. Esters; (b) Phenoxyethyl (meth) acrylate, benzyl (meth) acrylate and other aromatic ring-containing (meth) acrylic acid esters; (c) 2-hydroxyethyl (meth) acrylate, (meth) acrylic (Meta) acrylic acid hydroxyalkyl esters such as 4-hydroxybutyl acid; (d) glycidyl group-containing (meth) acrylic acid esters such as (meth) acrylic acid glycidyl alkyl ester and (meth) acrylic acid glycidyl alkyl ester; (e) ) (Meta) Acrylic acid alkoxyalkyl esters and the like. Only one kind of these (meth) acrylate-based monomers may be used, or two or more kinds thereof may be used in combination.

The acrylate-based rubber may further contain, as the structural unit, a structural unit derived from a vinyl-based monomer other than the (meth) acrylate-based monomer copolymerizable with the (meth) acrylate-based monomer. .. Examples of the vinyl-based monomer other than the (meth) acrylate-based monomer copolymerizable with the (meth) acrylate-based monomer include (a) the diene-based monomer described above and (b) a vinyl-based single amount. Examples of the body A include monomers other than the (meth) acrylate-based monomer.

The acrylic rubber has a crosslinked structure. To introduce a cross-linked structure, for example, a cross-linking agent and / or a graft cross-linking agent can be used when polymerizing a monomer component to synthesize a polymer of a core layer. Examples of the cross-linking agent and the graft crossing agent include (a) allylalkyl (meth) acrylates such as allyl (meth) acrylate and allylalkyl (meth) acrylate; (b) monoethylene glycol di (meth) acrylate and triethylene glycol di. Polyfunctional (meth) acrylates such as (meth) acrylates and tetraethylene glycol di (meth) acrylates; (c) Polyfunctional monomers such as diallyl phthalate, triallyl cyanurate, triallyl isocyanurate and divinylbenzene. And so on. Only one kind of these cross-linking agents and graft cross-linking agents may be used, or two or more kinds thereof may be used in combination.

Preferable examples of the acrylate-based rubber include acrylate-based rubbers such as butyl polyacrylate rubber and butyl acrylate / 2-ethylhexyl acrylate copolymer rubber. Butyl rubber polyacrylate is an elastic body containing 50 to 100% by weight of a structural unit derived from butyl acrylate in 100% by weight of the structural unit.

Suitable examples of the polyorganosiloxane-based rubber include silicone rubber and silicone / acrylate-based rubber.

Examples of the silicone rubber include polymethyl silicone rubber and polymethyl phenyl silicone rubber. Examples of the silicone / acrylate rubber include polyorganosiloxane / butyl acrylate copolymer and the like.

In one embodiment, the core layer preferably contains one or more selected from the group consisting of butadiene rubber, styrene / butadiene copolymer rubber, acrylate-based rubber and silicone rubber.

(Shell layer)
The shell layer is preferably formed from a polymer containing a structural unit derived from a vinyl-based monomer. Examples of the vinyl-based monomer include aromatic vinyl compounds, cyanide vinyl compounds, unsaturated carboxylic acid esters, acrylamide-based monomers, and maleimide-based monomers.

Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, α-methylvinyltoluene, dimethylstyrene, chlorstyrene, and dichlorostyrene. , Bromstyrene, dibromstyrene and the like are preferable.

Preferable examples of the vinyl cyanide compound include acrylonitrile, methacrylonitrile, and etacrylonitrile.

Examples of the unsaturated carboxylic acid ester include (a) methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, dodecyl acrylate, stearyl acrylate, behenyl acrylate and the like. Acrylic acid alkyl esters having an alkyl group having 1 to 22 carbon atoms; (b) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, methacrylic acid. Alkyl methacrylates having an alkyl group having 1 to 22 carbon atoms such as dodecyl, stearyl methacrylate, behenyl methacrylate; (c) methoxymethyl acrylate, methoxyethyl (meth) acrylate, (meth). ) Acrylic acid alkoxyalkyl esters having an alkyl group having 1 to 22 carbon atoms and having an alkoxyl group, such as ethoxymethyl acrylate and ethoxyethyl (meth) acrylic acid, and the like are preferable.

Preferable examples of the acrylamide-based monomer include acrylamide, methacrylamide, and N-methylacrylamide.

Examples of the maleimide-based monomer include N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N-octylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, and N. -Phenylmaleimide, etc. are preferably mentioned.

The polymer constituting the shell layer preferably contains one or more selected from acrylic acid alkyl esters and methacrylic acid alkyl esters as constituent monomers. These may be used alone or in combination of two or more.

Further, the polymer constituting the shell layer is at least selected from the group consisting of a carboxyl group-containing vinyl monomer, a hydroxyl group-containing vinyl monomer, and a glycidyl group-containing vinyl monomer as the constituent monomer. It is preferable to further contain one kind of reactive vinyl monomer. When the shell layer contains the reactive vinyl monomer as a constituent monomer, the core-shell type impact strength improving agent can be imparted with reactivity with the polyamide resin, and as a result, the core shell in the polyamide resin can be imparted. The dispersibility of the mold impact resistance improving agent is improved, and the effect of improving the impact strength can be enhanced. At the same time, the dispersibility of the additive in the polyamide resin can be improved. Among the reactive vinyl monomers, the carboxyl group-containing vinyl monomer is preferable because the reactivity with the polyamide resin is particularly good. Only one kind of the reactive vinyl monomer may be used, or two or more kinds thereof may be used in combination.

Examples of the carboxyl group-containing vinyl monomer include acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, isocrotonic acid, vinyloxyacetic acid, allyloxyacetic acid, 2- (meth) acryloylpropanoic acid, and 3-( Meta) Acryloylbutanoic acid, 4-vinylbenzoic acid, 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethylphthalic acid, 2-methacryloyloxyethylhexahydrophthalic acid and the like are preferably mentioned. Be done. Of these, acrylic acid and / or methacrylic acid is preferable, and methacrylic acid is more preferable.

Examples of the hydroxyl group-containing vinyl monomer include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and (meth). ) Hydroxyalkyl esters of (meth) acrylate having an alkyl group having 1 to 22 carbon atoms and having a hydroxyl group, such as 4-hydroxybutyl acrylate, are preferable.

Preferable examples of the glycidyl group-containing vinyl monomer include glycidyl (meth) acrylate.

The amount of the reactive vinyl monomer used can be appropriately set according to the desired effect, and is not particularly limited. However, when the reactive vinyl monomer is a carboxyl group-containing vinyl monomer, it is a core-shell type. The ratio of the carboxyl group-containing vinyl monomer to the entire polymer particles, which is an impact resistance improving agent, is preferably 0.05 to 1.4% by weight. When the ratio is within the above range, the effect of improving the impact strength of the polyamide resin by blending the core-shell type impact resistance improving agent can be enhanced. The lower limit of the ratio is preferably 0.1% by weight, more preferably 0.2% by weight. The upper limit of the ratio is preferably 1.2% by weight, more preferably 1.0% by weight, further preferably 0.9% by weight, still more preferably 0.7% by weight, and 0.6% by weight. Is particularly preferable, and 0.5% by weight is most preferable.

The weight ratio of the shell layer to the entire polymer particles, which is the core-shell type impact strength improving agent, is 1 to 1 from the viewpoint of compatibility between the core-shell type impact strength improving agent and the polyamide resin and the effect of improving the impact strength. 50% by weight is preferable, 5 to 40% by weight is more preferable, and 10 to 30% by weight is further preferable.

(Particle diameter of core-shell type impact resistance improving agent)
The particle size of the polymer particles, which is a core-shell type impact resistance improving agent, can be appropriately set, but the volume average particle size of the polymer particles is usually 100 nm or more. As the particle size increases, the impact strength tends to improve particularly at low temperatures. Therefore, the volume average particle size is preferably 130 nm or more, preferably 150 nm or more, further preferably 160 nm or more, still more preferably 170 nm or more. .. On the other hand, when the particle size of the polymer particles is large, the polymerization reaction takes a long time and the productivity tends to decrease. Therefore, the volume average particle size is preferably 400 nm or less, more preferably 350 nm or less, and more preferably 300 nm or less. More preferably, 250 nm or less is even more preferable. The volume average particle size of the polymer particles is a value measured by using a particle size measuring device in the state of latex of the polymer particles, as shown in the section of Examples. The volume average particle size of the polymer particles can also be calculated in a transmission electron microscope (TEM) image of the polyamide resin composition. The particle size of the polymer particles can be controlled by the type and amount of the polymerization initiator, chain transfer agent, oxidation reducing agent, emulsifier and the like, the polymerization temperature, the polymerization time and the like.

(Method for manufacturing polymer particles, which is a core-shell type impact resistance improving agent)
The method for producing the polymer particles, which is a core-shell type impact resistance improving agent, can be a conventional method and is not particularly limited. For example, any one of bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization can be adopted, but emulsion polymerization, that is, emulsion graft polymerization is preferable. In the emulsion graft polymerization, specifically, first, a latex of particles corresponding to the core layer is produced by emulsion polymerization, and the monomer component is polymerized by adding a monomer component for the shell layer, a polymerization initiator, etc. to the latex. do it.

(Polyolefin-based elastomer)
Examples of the polyolefin-based elastomer include polyolefin-based elastomers and hydrogenated styrene-based thermoplastic elastomers. Specific examples include an ethylene / propylene copolymer, an ethylene / butene-1 copolymer, an ethylene / hexene-1 copolymer, an ethylene / propylene / dicyclopentadiene copolymer, and an ethylene / propylene / 5-ethylidene-2. -Norbornene copolymer, unhydrogenated or hydrogenated styrene / isoprene / styrene triblock copolymer, unhydrogenated or hydrogenated styrene / butadiene / styrene triblock copolymer, ethylene / methacrylic acid copolymer, or these. Part or all of the carboxylic acid moiety in the copolymer is a salt of sodium, lithium, potassium, zinc and calcium; ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / Methyl methacrylate copolymer, ethylene / ethyl methacrylate copolymer, ethylene / ethyl acrylate-g-maleic anhydride copolymer, (“g” stands for graft, the same applies hereinafter), ethylene / methyl methacrylate- g-maleic anhydride copolymer, ethylene / ethyl acrylate-g-maleimide copolymer, ethylene / ethyl acrylate-g-N-phenylmaleimide copolymer, or partially saponified products of these copolymers; ethylene / Glycyzyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer, ethylene / methyl methacrylate / glycidyl methacrylate copolymer, ethylene / glycidyl acrylate copolymer, ethylene / vinyl acetate / glycidyl acrylate copolymer, ethylene / Glycidyl ether copolymer, ethylene / propylene-g-maleic anhydride copolymer, ethylene / butene-1-g-maleic anhydride copolymer, ethylene / propylene / 1,4-hexadien-g-maleic anhydride Polymer, ethylene / propylene / dicyclopentadiene-g-maleic anhydride copolymer, ethylene / propylene / 2,5-norbornadiene-g-maleic anhydride copolymer, ethylene / propylene-g-N-phenylmaleimide Polymer, ethylene / butene-1-g-N-phenylmaleimide copolymer, hydrogenated styrene / butadiene / styrene-g-maleic anhydride copolymer, hydrogenated styrene / isoprene / styrene-g-maleic anhydride Polymer, ethylene / propylene-g-glycidyl methacrylate copolymer, ethylene / butene-1-g-glycidyl methacrylate copolymer, ethylene / propylene / 1,4-hexadien Examples thereof include -g-glycidyl methacrylate copolymer, ethylene / propylene / dicyclopentadiene-g-glycidyl methacrylate copolymer, hydrogenated styrene / butadiene / styrene-g-glycidyl methacrylate copolymer and the like. Examples of commercially available elastomers include Tuffmer MH7020, MH7010, MA8510 manufactured by Mitsui Chemicals, Himiran 1706 manufactured by Mitsui DuPont, SEBS Tough Tech M1943 manufactured by Asahi Kasei Co., Ltd., PA-bond959 and PA-bond969 manufactured by Polymer Asia. PA-bond 979 and the like can be mentioned.

The modifier for a polyamide resin of the present embodiment contains the additive of the present embodiment and the impact resistance improving agent, and a person skilled in the art appropriately determines the ratio of the additive contained in the modifier. can do. However, from the viewpoint of the balance between the effect achieved by the additive and the effect achieved by the impact resistance improving agent, the ratio of the amount of the additive to the total amount of the additive and the impact resistance improving agent is 0.1. It is preferably 5% by weight or more and 25% by weight or less, more preferably 0.5% by weight or more and 15% by weight or less, and further preferably 1% by weight or more and 10% by weight or less.

The modifier for polyamide resin of this embodiment can be produced by mixing the additive of this embodiment with the impact resistance improving agent. In the production of the modifier, the additive and the impact resistance improving agent may be mixed in the powder state, respectively, but the additive and the impact strength improving agent are mixed in the latex state and then dried. It is preferable to obtain it as a powder. In particular, when the impact strength improving agent is a core-shell type impact strength improving agent, the method of mixing with latex can dramatically improve the melt tension of the polyamide resin composition in addition to the impact strength improving effect. It can be made and is effective for improving parison retention during blow molding. This allows the additive to be better compatible with the shell portion of the core-shell type impact strength improver during latex blending, resulting in core-shell type resistance when the modifier is kneaded with the polyamide resin. It is considered that the additive can be uniformly dispersed in the polyamide resin as the impact strength improving agent is dispersed.

(Amount of modifier compounded)
The modifier for a polyamide resin of the present embodiment is used by blending with a polyamide resin, and has an effect of improving moldability during melt processing, an effect of improving the tensile properties of a molded product, and an impact strength of the polyamide resin. Can have the effect of improving. The blending amount of the modifier with respect to the polyamide resin can be appropriately set, but the ratio of the modifier to the total of the polyamide resin and the modifier is preferably 1% by weight or more and 40% by weight or less. When the ratio of the modifier is within the above range, the effect of improving the moldability at the time of melt processing, the effect of improving the tensile properties of the molded product, and the effect of improving the impact strength of the polyamide resin are maintained while maintaining the physical properties peculiar to the polyamide resin. Can be preferably played. The ratio is more preferably 3 to 30% by weight, still more preferably 5 to 25% by weight.

(Polyamide resin)
The polyamide resin in the present embodiment is not limited as long as it is a polymer having an acid amide bond (-CONH-), but is, for example, a polymer obtained by polycondensation of diamine and dibasic acid, or a diamine derivative such as diformyl. Polymer obtained by polycondensation with dibasic acid, polymer obtained by polycondensation of dibasic acid derivative such as dimethyl ester with diamine, polymer obtained by reaction of dinitrile or diamide with formaldehyde, diisosyanate Examples thereof include a polymer obtained by double addition of dibasic acid and a polymer obtained by self-condensation of an amino acid or a derivative thereof, and a polymer obtained by ring-opening polymerization of lactam. Further, the polyamide resin may contain a polyether block. One type of polyamide resin may be used alone, or two or more types may be mixed and used.

Specific examples of the polyamide resin include nylon 4, nylon 6, nylon 6, 6, nylon 7, nylon 9, nylon 11, nylon 12, nylon 46, nylon 56, nylon 410, nylon 412, and nylon 610, which are aliphatic polyamides. , Nylon 612, Nylon 6T which is a semi-aromatic polyamide, Nylon 6I, Nylon 9T, Nylon 10T, Nylon M5T, Nylon MXD6, Nylon 6/66 which is a copolymerized polyamide, Nylon 6/12, Nylon 6/66/12, Examples thereof include nylon 6 / 6T, nylon 66 / 6T, nylon 6 / 6I, nylon 6T / 6I, nylon 6T / 12, nylon 66 / 6T / 6I and the like. Of these, nylon 6, nylon 6, 6, nylon 11 and nylon 12 are preferable from the viewpoint of versatility.

(Other resins)
The polyamide resin composition of the present embodiment may or may not contain a thermoplastic resin other than the polyamide resin. When a thermoplastic resin other than the polyamide resin is contained, the thermoplastic resin is not particularly limited, but for example, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyurethane, polytetrafluoroethylene, ABS resin, AS. Examples thereof include resins, acrylic resins, polyacetals, polycarbonates, modified polyphenylene ethers, polyethylene terephthalates, polybutylene terephthalates, and cyclic polyolefins. The blending amount of the other thermoplastic resin is not particularly limited, but is, for example, 0 to 100 parts by weight, preferably 0 to 50 parts by weight, more preferably 0 to 30 parts by weight, still more preferably 0 to 30 parts by weight, based on 100 parts by weight of the polyamide resin. Is 0 to 10 parts by weight.

(Other additives)
The polyamide resin composition of the present embodiment can appropriately contain additives that can be blended in a general thermoplastic resin composition. Such additives are not particularly limited, but are, for example, flame retardants, flame retardants, dripping inhibitors, reinforcing materials, fillers, antioxidants, pigments, dyes, conductivity-imparting agents, hydrolysis inhibitors, and the like. Examples thereof include thickeners, plasticizers, lubricants, ultraviolet absorbers, antistatic agents, fluidity improvers, mold release agents, compatibilizers, heat stabilizers and the like.

From the viewpoint of improving the impact strength, it is preferable that the polyamide resin composition of the present embodiment further contains a reinforcing material. Reinforcing materials include glass fiber, carbon fiber, boron fiber, asbestos fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, total aromatic polyamide fiber, polybenzoxazole fiber, polytetrafluoroethylene fiber, kenaf fiber, bamboo fiber, etc. Examples thereof include hemp fiber, bagus fiber, high-strength polyethylene fiber, alumina fiber, silicon carbide fiber, potassium titanate fiber, brass fiber, stainless steel fiber, steel fiber, ceramics fiber, genbuiwa fiber and the like. Among them, glass fiber, carbon fiber, and metal fiber are preferable, and glass fiber is more preferable, because the effect of improving impact strength is high. The reinforcing material may be used alone or in combination of two or more.

The blending amount of the reinforcing material can be appropriately set, but the ratio of the reinforcing material to 100% by weight of the total of the polyamide resin and the reinforcing material is preferably 10 to 60% by weight, preferably 15 to 50% by weight. % Is more preferred, and 20-40% by weight is even more preferred.

(Method for manufacturing composition)
The method for producing the polyamide resin composition of the present embodiment is not particularly limited, and a general method for producing a thermoplastic resin composition can be applied. For example, after mixing each raw material using a Henschel mixer, a tumbler mixer, or the like, melt kneading can be carried out to obtain a polyamide resin composition. For the melt kneading, a kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a pressure kneader, or a mixing roll can be used. By such melt kneading, pellets made of a polyamide resin composition can be produced.

The polyamide resin composition of the present embodiment can be molded into a predetermined shape to form a molded body. The molding method is not particularly limited, and for example, an injection molding method, an extrusion molding method, a blow molding method, a foam molding method, a calendar molding method, an inflation molding method, a rotation molding method, a press molding method and the like can be used.

(Use)
The polyamide resin composition and its molded body of the present embodiment include a cylinder head cover, an engine cover, an intake manifold, a radiator tank, an oil pan, an accelerator pedal, a canister, a fuel tube, an air brake tube, an exhaust gas tube, a hydrogen injector, and a duct. , Industrial fasteners, automotive applications such as door mirror stays, electrical / electronic applications such as coil bobbins, connectors, gears, sockets, switches, electric blanket coated wires, optical fiber cable coverings, electric tools, wire binding materials, hydraulic / pneumatic connectors・ Mechanical applications such as tubes, bearings, cover housings, bearings, pressure-resistant hoses, binding bands, curtain rail parts, aluminum sash corners, door rollers, handrails, curtain rollers, door handles and other building materials, sports shoe soles, skis Sports / leisure applications such as snowboard supplies, reels, diving snorkels, shrink wrapping films, food wrapping films, alcoholic beverage bottles, pesticide bottles and other packaging materials / containers, toothbrushes, chair legs and elbows, combs, knives Examples include daily necessities such as forks, medical uses such as medical catheters / pipes, medical packs, and sutures, but the present invention is not particularly limited.

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

(Weight average molecular weight)
The weight average molecular weight was determined by dissolving the sample in tetrahydrofuran (THF), filtering the soluble component with a filter system of 0.2 μm, and then using a high-speed GPC device (Tosoh Corporation, HLC-8220). Sample solution: sample 20 mg / THF 10 mL, column: manufactured by Tosoh Corporation, TSKgroupcool SuperHZ-H 1 bottle, and TSKgel SuperHZM-H 2 bottles, column temperature: 40 ° C., detector: differential refractive index, flow velocity: 0.35 mL / min. , Injection volume: 10 μL, Filtration line: Standard polystyrene).

(Volume average particle size of polymer particles)
The volume average particle diameter of the polymer particles was measured in the state of the polymer particle latex. As a measuring device, Nanotrac Wave manufactured by Nikkiso Co., Ltd. was used.

(Polymerization conversion rate)
A part of the obtained latex was collected and finely weighed, dried in a hot air dryer at 120 ° C. for 1 hour, and the weight after drying was finely weighed as the solid content. Next, the ratio of the precision results before and after drying was determined as the ratio of solid components in the latex. Finally, using this solid component ratio, the polymerization conversion rate was calculated by the following formula.
Formula: Polymerization conversion rate = (total weight of charged raw material x solid component ratio-total weight of raw material other than monomer) / weight of charged monomer x 100 (%)

(Manufacturing example of additives)
As a typical method for producing an additive, the procedure for producing the additive used in Examples 1 and 2 is shown below. The additives used in Examples and Comparative Examples other than Examples 1 and 2 are Example 1 except that the type and amount of the monomer used and the amount of the chain transfer agent are changed according to the description in the table. And 2 were manufactured according to the following description.

<Manufacturing of additive latex>
100 parts by weight of deionized water, 0.147 parts by weight of sodium hydroxide, and polyoxyethylene lauryl ether in a glass reactor equipped with a thermometer, agitator, a reflux condenser, a nitrogen inlet, and a device for adding a monomer and an emulsifier. 1.353 parts by weight of phosphoric acid was charged, and the temperature was raised to 70 ° C. while stirring in a nitrogen stream.
There, 0.0025 parts by weight of disodium ethylenediaminetetraacetate, 0.0015 parts by weight of ferrous sulfate heptahydrate, 0.3 parts by weight of sodium formaldehyde sulfoxylate, and 0.01 by weight of t-butyl hydroperoxide. The weight part was charged and stirred.
There, 11.05 parts by weight of methacrylic acid (hereinafter referred to as MAA), 38.95 parts by weight of styrene (hereinafter referred to as ST), 0.9 parts by weight of t-dodecyl mercaptan (chain transfer agent), n-dodecyl mercaptan (hereinafter referred to as ST). A mixture of 0.9 parts by weight (chain transfer agent) and 0.451 parts by weight of polyoxyethylene lauryl ether phosphate was added over 150 minutes. During the addition, an aqueous sodium hydroxide solution was added at any time to promote polymerization by adding t-butyl hydroperoxide at any time while keeping the pH at 6.5 to 7.0. After the addition of the mixture was completed, the mixture was stirred for 30 minutes while cooling the temperature from 70 ° C. to 50 ° C., and t-butyl hydroperoxide was added as needed during stirring to promote the polymerization. As a result, the first polymer was formed with a polymerization addition rate of 97%.
Then, a mixture of ST43.28 parts by weight, butyl acrylate (hereinafter referred to as BA) 6.72 parts by weight, polyoxyethylene lauryl ether phosphoric acid 0.451 parts by weight, and t-butyl hydroperoxide 0.08 parts by weight. Was added over 150 minutes. Aqueous sodium hydroxide solution was added at any time during the addition to keep the pH at 6.5-7.0. After completion of the addition, 0.01 part by weight of t-butyl hydroperoxide was added 3 times every 10 minutes, and then the mixture was stirred for 30 minutes to form a second polymer with a polymerization addition rate of 98%. From the above, the latex of the additive containing the first polymer and the second polymer was obtained.
<Acquisition of white resin powder as an additive>
The temperature was raised to 70 ° C. while stirring 650 parts by weight of deionized water and 3.5 parts by weight of a 25% by weight aqueous solution of calcium chloride, and the additive latex was added thereto to obtain a slurry containing coagulated latex particles. Then, the solidified latex particle slurry was heated to 95 ° C., dehydrated and dried to obtain a particulate additive containing the first polymer and the second polymer as a white resin powder.

(Examples 1 to 15 and Comparative Examples 1 to 3) Production of Polyamide Resin Composition According to the following description, pellets and test pieces composed of the composition containing the polyamide resin and the white resin powder of the additive were prepared. MFR, tensile properties, Izod impact strength, and HDT were measured. However, in Comparative Example 1, the evaluation was performed without using the white resin powder of the additive. MFR or melt tension was used as an index indicating the formability at the time of melt processing. The smaller the MFR value, the lower the fluidity at the time of melting, and the better the moldability at the time of melting. Further, the larger the value of the melt tension, the better the formability at the time of melt processing.

(Conditions for preparing pellets and test pieces)
(A) Polyamide 6 resin (Durethan B29 manufactured by Lanxess) 99.0 parts by weight or 98.0 parts by weight (b) 1 part by weight or 2 parts by weight of the white resin powder of the additive (c) Hindered phenolic antioxidant (BASF's Irganox 1076) 0.1 part by weight (d) Phosphorus-based processing stabilizer (BASF's Irgafos 168) 0.2 parts by weight

The mixture of (a) to (d) is kneaded and extruded by a twin-screw extruder (TEX44SS manufactured by Japan Steel Works, Ltd.) heated to a barrel temperature of 230 to 260 ° C. under the condition of a screw rotation speed of 100 rpm. , Pellets were obtained.
The pellets are dried at 80 ° C. for 12 hours in a dryer to sufficiently reduce the water content, and then molded in an injection molding machine (FAS100B manufactured by FANUC Corporation) at a molding temperature of 270 to 290 ° C. and a mold temperature of 80 ° C. Under the conditions, a test piece was prepared.

(MFR)
The pellets prepared under the above-mentioned conditions were dried at 120 ° C. for 12 hours in a hot air dryer, and then the MFR value was measured under the conditions of a measurement temperature of 280 ° C. and a load of 5 kg according to the JIS K7210 A method.

(Melting tension)
It was determined by melting the pellets produced under the above-mentioned conditions and measuring the stress when stretched at a constant acceleration, and measured under the following conditions. The melting tension was measured in Examples 7-8 and 16 and Comparative Examples 1 and 4-5.
[Measurement condition]
Model used: Capillary Leometer (Gottfert, RG25)
Capillary die: caliber 2 mm, length 20 cm
Winding speed: 17 mm / s
Acceleration: (Table 1) 6 mm / s ² , (Table 2) 12 mm / s ²
Measurement temperature: (Table 1) 228 ° C, (Table 2) 238 ° C

(Tensile characteristics)
A 3.2 mm thick ASTM D638-1 type test piece produced by the method described above is tensioned at 23 ° C. at a test speed of 50 mm / min by a method conforming to the ASTM D638 standard in an absolutely dry state. Properties (tensile modulus, tensile yield stress, tensile fracture stress, and tensile fracture strain) were measured.

(Izod impact strength)
A test piece having a length of 63.5 mm, a width of 12.7 mm, a thickness of 3.2 mm, and a v-notch prepared by the above-mentioned method was subjected to an absolute dry state at −30 ° C. by a method conforming to the ASTM D256 standard. And Izod impact strength at 23 ° C. was measured.

(HDT)
A test piece having a length of 127 mm, a width of 12.7 mm, and a thickness of 6.4 mm produced by the above-mentioned method was annealed at 100 ° C. for 1 hour, and then 18.6 kgf / cm ² by a method conforming to the ASTM D648 standard. HDT was measured under the load of.
The results of the above measurements are shown in Table 1.

From Table 1, Examples 1 to 15 have a significantly smaller MFR value as compared with Comparative Examples 1 to 3, that is, have good moldability during melt processing, and are molded as compared with Comparative Examples 1 and 2. It can be seen that the tensile properties of the body are also good. Among the examples, Examples 7 to 15 are particularly good. Further, in Examples 7 and 8, the value of the melt tension is larger than that in Comparative Example 1, and it can be seen that the formability at the time of melt processing is also good in this respect. In Comparative Example 1, no additive was blended, and the additives used in Comparative Examples 2 and 3 did not contain methacrylic acid, which is a carboxyl group-containing vinyl monomer, and instead contained an epoxy group-containing vinyl simple substance. It contains glycidyl methacrylate, which is a monomer.

(Manufacturing of core-shell type impact strength improving agent)
<Manufacturing of polybutadiene rubber latex (core layer)>
170 parts by weight of deionized water, 0.002 parts by weight of disodium ethylenediamine tetraacetate, 0.0012 parts by weight of ferrous sulfate heptahydrate, and 0.13 parts by weight of sodium dodecylbenzene sulfonate in a pressure-resistant polymerizer. Was sufficiently degassed while stirring to remove oxygen, and then 100 parts by weight of butadiene (hereinafter referred to as BD) was added to the system and the temperature was raised to 45 ° C. 0.05 part by weight of sodium formaldehyde sulfoxylate and 0.03 part by weight of paramentan hydroperoxide were added thereto to initiate polymerization. 0.014 parts by weight of paramentan hydroperoxide was added to each of the 6th, 10th, 14th, and 17th hours from the start of the polymerization. At the 20th hour of the polymerization, the residual monomer was volatilized and removed under reduced pressure to complete the polymerization, and a polybutadiene rubber latex having a volume average particle diameter of 180 nm containing the polybutadiene rubber as a main component was obtained.

<Manufacturing of polymer particle latex>
30 parts by weight of deionized water and 78 parts by weight of the above-mentioned polybutadiene rubber latex are added to a glass reactor having a thermometer, a stirrer, a reflux condenser, a nitrogen inlet, and a device for adding a monomer and an emulsifier. The temperature was raised to 60 ° C. while stirring in a nitrogen stream. Next, 0.00032 parts by weight of disodium ethylenediaminetetraacetate, 0.00008 parts by weight of ferrous sulfate, and 0.04 parts by weight of sodium formaldehyde sulfoxylate were charged. A mixture of 19.62 parts by weight of methyl methacrylate (hereinafter referred to as MMA), 2.18 parts by weight of BA, 0.2 parts by weight of MAA, and 0.024 parts by weight of t-butyl hydroperoxide was added thereto over 68 minutes. Added. After 5 minutes from the completion of the addition, 0.015 parts by weight of formaldehyde sulfoxylate sodium was added, after another 5 minutes, 0.01 part by weight of t-butyl hydroperoxide, and after another 5 minutes, t-butyl hydroperoxide 0.01. After repeating the step of adding the parts by weight twice, the mixture was stirred for 50 minutes to obtain a polymer particle latex having a polymerization conversion rate of 100%.

(Manufacturing of modifiers containing additives and polymer particles)
IRGANOX-1076 [n-octadecyl-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate], which is a hindered phenolic antioxidant, was added in an amount of 3.0 parts by weight. The polymer particle latex and the additive latex used in Examples 7 and 8 described above were blended so as to have a solid content of 98: 2 (weight basis) to obtain a blended latex. The temperature was raised to 60 ° C. while stirring 760 parts by weight of deionized water and 3.5 parts by weight of a 25% by weight aqueous solution of calcium chloride, and the blended latex was added thereto to obtain a slurry containing solidified latex particles. The solidified latex particle slurry was heated to 90 ° C., dehydrated and dried to obtain a modifier containing an additive and polymer particles (core-shell type impact resistance improving agent) as a white resin powder.
Further, only the polymer particles (core-shell type impact resistance improving agent) were obtained as white resin powder by the same procedure except that the additive latex was not used.

(Example 16 and Comparative Examples 4 to 5) Production of Polyamide Resin Composition According to the formulation shown in Table 2, pellets and test pieces composed of a composition containing a polyamide resin and a white resin powder of the modifier are described above. The MFR, melt tension, tensile properties, and Izod impact strength were measured according to the method described above. However, in Comparative Example 4, the evaluation was performed without using the white resin powder of the modifier, and in Comparative Example 5, the polymer particles (core-shell type impact resistant) were used instead of the white resin powder of the modifier. Evaluation was performed using a white resin powder containing only a strength improver). The results obtained are shown in Table 2.
As the polyamide resin, a polyamide 6 resin (UBE 1030B manufactured by Ube Kosan Co., Ltd.) was used.

From Table 2, in Example 16, the MFR value is smaller and the melt tension value is larger than in Comparative Examples 4 to 5, that is, the formability at the time of melt processing is good, and compared with Comparative Example 5. It can be seen that both the tensile properties and the Izod impact strength are good.

(Examples 17 to 21 and Comparative Examples 6 to 8) Production of Polyamide Resin Composition A composition containing a glass fiber reinforced polyamide resin, a white resin powder of the additive, and optionally a polyolefin-based elastomer according to the formulation shown in Table 3. Pellets and test pieces composed of the material were prepared according to the following description, and MFR, tensile properties, Izod impact strength, and HDT were measured according to the method described above. However, in each comparative example, the evaluation was performed without using the white resin powder of the additive. The results obtained are shown in Table 3.

(Conditions for preparing pellets and test pieces)
(A) Glass fiber reinforced polyamide 6 resin (CM1016G-30 manufactured by Toray Co., Ltd., containing 30% by weight of glass fiber) Part of weight shown in Table 3 (b) White resin powder of the additive used in Examples 7 and 8 described above. Parts by weight shown in Table 3 (c) Maleic anhydride-modified polyolefin elastomer (MH7020 manufactured by Mitsui Chemicals, Inc.) Parts by weight shown in Table 3 (d) Hindered phenolic antioxidant (Irganox 1076 manufactured by BASF) 0.21 weight Part (e) Phosphorus-based processing stabilizer (Irgafos 168 manufactured by BASF) 0.09 parts by weight

From the mixture of the above (a) to (e), pellets were obtained by the above-mentioned method, and then a test piece was prepared.

From Table 3, Examples 17 to 19 in which the additive was added to the glass fiber reinforced polyamide resin had a smaller MFR value as compared with Comparative Example 6 not containing the additive, that is, the moldability at the time of melt processing was good. Further, it can be seen that both the tensile properties and the Izod impact strength are better than those of the comparative example.
Regarding the system in which the polyolefin-based elastomer is blended with the glass fiber reinforced polyamide resin, the example 20 containing the additive has a smaller MFR value, the tensile property, and the Izod impact as compared with the comparative example 7 not containing the additive. It can be seen that both strengths are good. Further, it can be seen that the MFR value of Example 21 is smaller than that of Comparative Example 8, and both the tensile characteristics and the Izod impact strength are good.

(Examples 22 to 27 and Comparative Examples 9 to 10) Production of Polyamide Resin Composition According to the formulation shown in Table 4, pellets and test pieces composed of the composition containing the polyamide resin and the white resin powder of the additive are prepared. It was made according to the description below, and MFR, tensile properties, Izod impact strength, and HDT were measured according to the method described above. However, in each comparative example, the evaluation was performed without using the white resin powder of the additive. The results obtained are shown in Table 4.

(Conditions for preparing pellets and test pieces)
(A) Polyamide 66 resin (Asahi Kasei Leona 1300 or Asahi Kasei Leona 1700) Part by weight shown in Table 4 (b) White resin powder of the additive used in Examples 7 and 8 described above In Table 4. 0.21 parts by weight (c) Hindered phenolic antioxidant (Irganox 1076 manufactured by BASF) 0.21 parts by weight (d) Phosphorus-based processing stabilizer (Irgafos 168 manufactured by BASF) 0.09 parts by weight

From the mixture of the above (a) to (d), pellets were obtained by the above-mentioned method, and then a test piece was prepared.

From Table 4, Examples 22 to 24 in which the additive was added to nylons 6 and 6 had a smaller MFR value as compared with Comparative Example 9 not containing the additive, that is, the moldability at the time of melt processing was good. Further, it can be seen that the tensile properties are better than those of Comparative Example 9.
It can also be seen that in Examples 25 to 27, the MFR value is smaller and the tensile properties are better than in Comparative Example 10.

Claims (17)

1. An additive for a polyamide resin containing a first polymer.
   The first polymer has (i) a carboxyl group-containing vinyl monomer as a constituent monomer, and
   (Ii) (meth) acrylic acid ester monomer and / or aromatic vinyl monomer,
   Is a copolymer containing
   The first polymer is an additive for a polyamide resin having a weight average molecular weight of 2,000 to 25,000.
2. The additive for a polyamide resin according to claim 1, wherein the carboxyl group-containing vinyl monomer accounts for 15% by weight or more and 50% by weight or less of the 100% by weight of the first polymer.
3. The first polymer is a copolymer containing (i) a carboxyl group-containing vinyl monomer and (ii) a (meth) acrylic acid ester monomer as constituent monomers. Or the additive for a polyamide resin according to 2.
4. The additive for a polyamide resin according to any one of claims 1 to 3, further comprising a second polymer having a weight average molecular weight of 100,000 or more.
5. The additive for a polyamide resin according to claim 4, wherein the first polymer constitutes particles and at least a part of the second copolymer is located outside the particles.
6. The additive for a polyamide resin according to claim 4 or 5, wherein the second polymer is a polymer containing a methacrylic acid ester monomer and / or an aromatic vinyl monomer as a constituent monomer.
7. The polyamide resin according to claim 6, wherein the total of the methacrylic acid ester monomer and the aromatic vinyl monomer accounts for 80% by weight or more and 100% by weight or less of the 100% by weight of the second polymer. Additive.
8. The additive for a polyamide resin according to any one of claims 4 to 7, wherein the first polymer and / or the second polymer is a non-rubber-like polymer.
9. The first polymer and the second polymer are non-rubber-like polymers, respectively, the first polymer constitutes particles, and at least a part of the second polymer is located outside the particles. The additive for a polyamide resin according to any one of claims 4 to 7.
10. A modifier for a polyamide resin, which comprises the additive according to any one of claims 1 to 9 and the impact resistance improving agent.
11. The modifier for a polyamide resin according to claim 10, wherein the impact resistance improving agent is a core-shell type impact strength improving agent.
12. The modifier for a polyamide resin according to claim 10, wherein the impact resistance improving agent is a polyolefin-based elastomer.
13. The polyamide resin and the additive for the polyamide resin according to any one of claims 1 to 9 are contained.
    A polyamide resin composition in which the ratio of the additive to 100% by weight of the total of the polyamide resin and the additive is 0.1 to 10% by weight.
14. The polyamide resin and the modifier for a polyamide resin according to any one of claims 10 to 12 are contained.
    A polyamide resin composition in which the ratio of the modifier to 100% by weight of the total of the polyamide resin and the modifier is 1 to 40% by weight.
15. The polyamide resin composition according to claim 13 or 14, further containing a reinforcing material, wherein the ratio of the reinforcing material to 100% by weight of the total of the polyamide resin and the reinforcing material is 10 to 60% by weight.
16. A pellet made of the polyamide resin composition according to any one of claims 13 to 15.
17. A molded product made of the polyamide resin composition according to any one of claims 13 to 15.