JP5746891B2 - Reinforced thermoplastic resin composition - Google Patents

Description

  The present invention relates to a reinforced thermoplastic resin composition containing a polyamide resin.

  Polyamide resin has excellent mechanical strength, chemical resistance, wear resistance, etc., so it is used in many applications such as automobiles, industrial products such as electrical / electronic / mechanical parts, sports / leisure products, etc. . However, the polyamide resin has the disadvantages that the paintability and impact resistance are inferior, and also has a problem that it easily absorbs water and has a large dimensional change due to its chemical structure. Therefore, much research has been done in the past to improve these drawbacks.

For example, a rubber-modified nylon composition in which an carboxylic acid group-containing copolymer obtained by copolymerizing an unsaturated carboxylic acid and styrene or acrylonitrile is used as a compatibilizing agent and an ABS resin is blended with a polyamide resin has been proposed ( Patent Document 1).
Polyamide resins are also known to dramatically improve the heat resistance, dimensional stability, and rigidity of molded products by adding inorganic fillers such as glass fibers and carbon fibers. A thermoplastic resin composition in which glass fiber, carbon fiber, or the like is blended with a resin-containing composition has been proposed (see Patent Document 2). This thermoplastic resin composition becomes a molded article material having excellent impact resistance, dimensional stability, rigidity, and heat resistance, and a good performance balance.

Japanese Patent Publication No. 7-84549 JP 2002-212383 A

  However, the rubber-modified nylon composition described in Patent Document 1 has a problem that the heat resistance and rigidity of the molded product are insufficient. For example, a load is applied at a high temperature such as a heating device, a cooking appliance, or a thermal analysis device. It was unsuitable for such a use. In addition, there is a problem that it is difficult to use in applications where design properties are required.

On the other hand, although the molded product obtained from the thermoplastic resin composition described in Patent Document 2 is excellent in heat resistance at low load, the heat resistance at high load is insufficient.
In order to improve heat resistance under high loads, the amount of polyamide resin should be increased. However, increasing the amount of polyamide resin tends to lower the rigidity during moisture absorption, and inorganic fillers such as glass fiber and carbon fiber. The effect of adding is not fully exhibited.
In addition, materials with inorganic fillers such as glass fiber and carbon fiber are prone to emerge on the surface of the molded product, especially when the molded product is painted. There was a tendency to damage.

By the way, the polyamide resin and the ABS resin are incompatible, and in order to obtain a molded product having sufficient physical properties and design properties, as described in Patent Document 1, an unsaturated carboxylic acid and styrene or acrylonitrile are used. It is necessary to add a compatibilizing agent such as a carboxylic acid group-containing copolymer obtained by copolymerization or to introduce a reactive functional group into the graft chain of the ABS resin. However, when a compatibilizing agent is added or a reactive functional group is introduced into the graft chain of the ABS resin, heat resistance and impact resistance under high load may be insufficient.
Accordingly, there has been a demand for a material that can obtain a molded product that has a small decrease in rigidity at the time of moisture absorption, is excellent in impact resistance, heat resistance at high load, and is excellent in design at the time of coating.

  The present invention provides a reinforced thermoplastic resin composition capable of obtaining a molded article that has a small decrease in rigidity at the time of moisture absorption, is excellent in impact resistance, heat resistance at high loads, and is excellent in design at the time of coating. The purpose is to provide.

The present invention includes the following aspects.
[1] In the presence of 40 to 75 parts by mass of a rubbery polymer (a) composed of an acid-modified low molecular weight α-olefin copolymer having an viscosity average molecular weight of 1000 to 9000 and an ethylene-propylene-nonconjugated diene copolymer 25 to 60 parts by mass of a monomer mixture containing 60 to 95% by mass of aromatic vinyl (b) and 5 to 40% by mass of vinyl cyanide (c) (however, the total of the rubber polymer (a)) The graft copolymer (A) is 20 to 40 parts by mass, the maleimide monomer (d) is 5 to 50% by mass, and the maleimide monomer (d). copolymerizable with the monomers 50 to 95 wt% and the copolymerized maleimide copolymer (B) 5 to 20 parts by mass of a polyamide resin relative viscosity of 1.8 to 2.7 ( C) and 50 to 65 parts by weight, the graft copolymer ( ), A maleimide copolymer (B) and a polyamide resin (C) in a total of 100 parts by mass, the reinforced thermoplastic resin composition is characterized by containing 1 to 50 parts by mass of an inorganic filler (D). .
[2] The reinforced thermoplastic resin composition according to [1], wherein the maleimide copolymer (B) has a mass average molecular weight of 90000 to 200000 .

  The reinforced thermoplastic resin composition of the present invention is capable of obtaining a molded article that is less likely to decrease in rigidity during moisture absorption, has excellent impact resistance, heat resistance at high loads, and is excellent in design during coating. .

Hereinafter, the present invention will be described in detail.
<Reinforced thermoplastic resin composition>
The reinforced thermoplastic resin composition of the present invention contains a graft copolymer (A), a maleimide copolymer (B), a polyamide resin (C), and an inorganic filler (D).

(Graft copolymer (A))
The graft copolymer (A) is obtained by graft polymerization of a monomer mixture containing an aromatic vinyl (b) and a vinyl cyanide (c) in the presence of the rubbery polymer (a).

The rubber polymer (a) comprises an acid-modified low molecular weight α-olefin copolymer and an ethylene-propylene-nonconjugated diene copolymer.
Examples of the acid-modified low molecular weight α-olefin copolymer include an acid-modified low molecular weight α-olefin copolymer obtained by graft-polymerizing an unsaturated carboxylic acid to a polyolefin such as polyethylene.
Here, examples of the α-olefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and copolymers thereof. As the unsaturated carboxylic acid, Acrylic acid, maleic acid, itaconic acid, maleic anhydride, itaconic anhydride, maleic acid monoamide and the like can be mentioned.
As the acid-modified low molecular weight α-olefin copolymer, acid-modified polyethylene is preferable.

  The content of α-olefin units in 100% by mass of the acid-modified low molecular weight α-olefin copolymer is 80 to 99.8% by mass, and the content of unsaturated carboxylic acid units is 0.2 to 20% by mass. It is preferable. If the content of the α-olefin unit is 80% by mass or more and the content of the unsaturated carboxylic acid unit is 20% by mass or less, the rigidity and heat resistance of the molded product obtained by molding the reinforced thermoplastic resin composition of the present invention are improved. It tends to improve. On the other hand, when the content of the α-olefin unit is 99.8% by mass or less and the content of the unsaturated carboxylic acid unit is 0.2% by mass or more, the polymerization stability in obtaining the graft copolymer (A). Will improve.

The viscosity average molecular weight of the acid-modified low molecular weight α-olefin copolymer is preferably 1000 to 9000, and more preferably 1500 to 4000. When the viscosity average molecular weight of the acid-modified low molecular weight α-olefin copolymer is within the above range, the dispersibility and compatibility with the ethylene-propylene-nonconjugated diene copolymer are excellent.
Here, the viscosity average molecular weight is a value measured in accordance with JIS K 7367-3, the solvent being decahydronaphthalene, and the temperature being 135 ° C.

  The content of the acid-modified low molecular weight α-olefin copolymer is preferably 1 to 40% by mass and more preferably 5 to 20% by mass in 100% by mass of the rubbery polymer (a). If the content of the acid-modified low molecular weight α-olefin copolymer is 1% by mass or more, the graft copolymer (A) and the polyamide resin (C) are easily compatible with each other. The impact resistance of the molded product obtained by molding the resin composition is further improved. Furthermore, since it is not necessary to add a compatibilizing agent separately, the heat resistance under a high load is further improved. On the other hand, when the content of the acid-modified low molecular weight α-olefin copolymer is 40% by mass or less, the impact resistance of the molded product is further improved. However, even if the content of the acid-modified low molecular weight α-olefin copolymer exceeds 40% by mass, the compatibility of the graft copolymer (A) and the polyamide resin (C) is not improved. On the other hand, the impact resistance of the molded product may be lowered and the appearance may be poor.

On the other hand, the ethylene-propylene-nonconjugated diene copolymer preferably contains 1,4-hexadiene, 5-ethylidene-2-norbornene, 5-vinylnorbornene, dicyclopentadiene or the like as the nonconjugated diene component.
The ethylene-propylene-nonconjugated diene copolymer is preferably crosslinked. If the ethylene-propylene-nonconjugated diene copolymer is crosslinked, the impact resistance and chemical resistance of the molded product obtained by molding the reinforced thermoplastic resin composition of the present invention are further improved.

Examples of the aromatic vinyl (b) include styrene, α-methyl styrene, o-, m- or p-methyl styrene, vinyl xylene, pt-butyl styrene, and ethyl styrene. Among these, styrene and α-methylstyrene are preferable.
These aromatic vinyls (b) may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  Content of aromatic vinyl (b) in 100 mass% of monomer mixtures is 60-95 mass%, and it is preferable that it is 65-80 mass%. If the content of the aromatic vinyl (b) in the monomer mixture is within the above range, the impact resistance and the heat resistance under a high load of the molded product obtained by molding the reinforced thermoplastic resin composition of the present invention are improved. To do. Moreover, the moldability of the reinforced thermoplastic resin composition is improved.

Examples of vinyl cyanide (c) include acrylonitrile and methacrylonitrile.
These vinyl cyanides (c) may be used alone or in combination of two or more.

  Content of vinyl cyanide (c) in 100 mass% of monomer mixtures is 5-40 mass%, and it is preferable that it is 20-35 mass%. If the content of vinyl cyanide (c) in the monomer mixture is within the above range, the impact resistance and the heat resistance under high load of the molded article formed from the reinforced thermoplastic resin composition of the present invention are improved. To do. Moreover, the moldability of the reinforced thermoplastic resin composition is improved.

In the monomer mixture, in addition to the above aromatic vinyl (b) and vinyl cyanide (c), other monomers (e) copolymerizable therewith are included within a range not impairing the effects of the present invention. Can be used in
Other monomers (e) include α, β-unsaturated carboxylic acids such as acrylic acid and methacrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) Α, β-unsaturated carboxylic acid esters such as acrylate, 2-ethyl (meth) acrylate and 2-ethylhexyl methacrylate; α, β-unsaturated dicarboxylic acid anhydrides such as maleic anhydride and itaconic anhydride It is done.
These other monomers (e) may be used individually by 1 type, and 2 or more types may be mixed and used for them.
In the present invention, “(meth) acrylate” means acrylate and methacrylate.

The graft copolymer (A) can be obtained by graft polymerization of a monomer mixture in the presence of the rubber polymer (a) described above.
The ratio of the rubbery polymer (a) at the time of graft polymerization is 40 to 75 parts by mass, and the ratio of the monomer mixture is 25 to 60 parts by mass (provided that the rubbery polymer (a) and the monomer are mixed). The total of the mixture is 100 parts by mass). If the ratio of the rubbery polymer (a) is 40 parts by mass or more and the ratio of the monomer mixture is 60 parts by mass or less, the impact resistance and high resistance of the molded article obtained by molding the reinforced thermoplastic resin composition of the present invention are high. Heat resistance during loading is improved. On the other hand, if the ratio of the rubbery polymer (a) is 75 parts by mass or less and the ratio of the monomer mixture is 25 parts by mass or more, the phase of the graft copolymer (A) and the maleimide polymer (B) The solubility is improved and the impact resistance of the molded product is improved.
The proportion of the rubbery polymer (a) at the time of graft polymerization is preferably 50 to 70 parts by mass, and the proportion of the monomer mixture is preferably 30 to 50 parts by mass.

The graft copolymer (A) is produced by a known method such as a bulk polymerization method, a solution polymerization method, a bulk suspension polymerization method, a suspension polymerization method, or an emulsion polymerization method, and emulsion polymerization can be easily performed. preferable.
Below, an example of the method of manufacturing a graft copolymer (A) by emulsion polymerization is shown.

(I) First, a predetermined amount of an ethylene-propylene-nonconjugated diene copolymer and an acid-modified low molecular weight α-olefin copolymer is dissolved in a solvent, and an emulsifier is added thereto to emulsify, thereby producing a rubber polymer. Prepare the liquid.
As the solvent, aliphatic or alicyclic hydrocarbon solvents such as n-hexane and cyclohexane can be used.
As the emulsifier, for example, an anionic surfactant such as potassium oleate and disproportionated potassium rosinate can be used. The addition amount of the emulsifier is preferably 1 to 10 parts by mass with respect to 100 parts by mass of the ethylene-propylene-nonconjugated diene copolymer.
As the emulsifier, for example, oleic acid is mixed with an ethylene-propylene-nonconjugated diene copolymer and an acid-modified low molecular weight α-olefin copolymer solution, and then an aqueous potassium hydroxide solution is added to the mixture. It can also be added by forming potassium oleate in solution.

(Ii) After adding water to the rubbery polymer-containing liquid, this is sufficiently stirred and the solvent is distilled off to obtain a latex having an average particle size of 0.2 to 1.0 μm.

(Iii) Next, with respect to 100 parts by mass of the ethylene-propylene-nonconjugated diene copolymer in the latex, 5.0 parts by mass or less of a polyfunctional compound such as divinylbenzene, di-t-butyl-oxytrimethyl An organic peroxide such as cyclohexane is added in an amount of 0.1 to 5.0 parts by mass and reacted at 60 to 140 ° C. for about 0.5 to 5.0 hours. In this way, a latex of an ethylene-propylene-nonconjugated diene copolymer crosslinked product (hereinafter simply referred to as “copolymer crosslinked product”) is prepared.

This copolymer crosslinked product has a better physical property balance of the reinforced thermoplastic resin composition, so that the gel content is 30 to 90% by mass and the average particle size is 0.2 to 1.0 μm. preferable. When the gel content of the copolymer crosslinked product is 30% by mass or more, the impact resistance of the molded product obtained by molding the reinforced thermoplastic resin composition of the present invention is further improved and the surface appearance is improved. However, when the gel content of the copolymer cross-linked product exceeds 90% by mass, the impact resistance of the molded product tends to decrease.
Moreover, if the average particle diameter of a copolymer crosslinked material is 0.2 micrometer or more, the impact resistance of a molded article will improve more, and if it is 1 micrometer or less, the surface external appearance of a molded article will become favorable.

Here, the gel content of the latex of the crosslinked copolymer is measured by the following method.
First, the latex of the crosslinked copolymer is washed with dilute sulfuric acid and dried, and 1 g of this is collected and immersed in 200 mL of toluene at 115 ° C. for 5 hours. Next, after filtration through a 200 mesh stainless steel wire mesh, the obtained residue is dried. After drying, the residue is weighed and the gel content is determined by the following formula.
Gel content (%) = (mass of residue after drying / mass of sample before immersion in toluene) × 100

(Iv) Next, a monomer mixture containing a predetermined amount of aromatic vinyl (b) and vinyl cyanide (c) is added to the latex of the crosslinked copolymer, and the mixture is appropriately heated and graft polymerized.

(V) After completion of the graft polymerization, an antioxidant is added if necessary, and then a coagulant is added to the obtained graft copolymer latex to solidify the resin solids.
Examples of the coagulant include aqueous solutions of sulfuric acid, acetic acid, calcium chloride, calcium acetate, magnesium sulfate, and the like. One type of coagulant may be used alone, or two or more types may be mixed and used.

(Vi) The obtained resin solid is separated and washed with water, dehydrated and dried to obtain the graft copolymer (A).

  The content of the graft copolymer (A) is 20 to 40 parts by mass when the total of the graft copolymer (A), the maleimide copolymer (B) and the polyamide resin (C) is 100 parts by mass. It is preferable that it is 23-35 mass parts. If content of a graft copolymer (A) is 20 mass parts or more, the impact resistance of the molded article which shape | molded the reinforced thermoplastic resin composition of this invention will improve. On the other hand, when the content of the graft copolymer (A) is 40 parts by mass or less, the heat resistance and mechanical properties of the molded product are improved.

(Maleimide copolymer (B))
The maleimide copolymer (B) is a copolymer of a maleimide monomer (d) and another monomer (f) copolymerizable with the maleimide monomer (d). .

Examples of the maleimide monomer (d) include maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-toluylmaleimide, Examples include N-xylylmaleimide, N-naphthylmaleimide, Nt-butylmaleimide, N-orthochlorophenylmaleimide, N-orthomethoxyphenylmaleimide and the like. Among these, N-cyclohexylmaleimide, N-phenylmaleimide, N-toluylmaleimide, N-orthochlorophenylmaleimide, N-orthomethoxyphenylmaleimide are preferable, and N-cyclohexylmaleimide and N-phenylmaleimide are more preferable.
These maleimide monomers (d) may be used alone or in a combination of two or more.

  The content of the maleimide monomer (d) is 5 to 50% by mass when the total of the maleimide monomer (d) and the other monomer (f) is 100% by mass, and 20 It is preferable that it is -50 mass%. If the content of the maleimide monomer (d) is 5% by mass or more, the heat resistance of the maleimide copolymer (B) is increased. Therefore, a molded product obtained by molding the reinforced thermoplastic resin composition of the present invention. The heat resistance at high loads is improved. On the other hand, when the content of the maleimide monomer (d) is 50% by mass or less, the impact resistance of the molded product is improved. Moreover, the moldability of the reinforced thermoplastic resin composition is improved.

Examples of the other monomer (f) copolymerizable with the maleimide monomer (d) include the aromatic vinyl (b) and vinyl cyanide (c) exemplified above in the description of the graft copolymer (A). ), Aromatic vinyl (b) and other monomers (e) copolymerizable with vinyl cyanide (c).
These other monomers (f) may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  Content of another monomer (f) is 50-95 mass% when the sum total of a maleimide-type monomer (d) and another monomer (f) is 100 mass%, 50 It is preferable that it is -80 mass%. If content of another monomer (f) is 50 mass% or more, the impact resistance of the molded article which shape | molded the reinforced thermoplastic resin composition of this invention will improve. Moreover, the moldability of the reinforced thermoplastic resin composition is improved. On the other hand, if the content of the other monomer (f) is 95% by mass or less, the heat resistance of the maleimide-based copolymer (B) is increased, so that the heat resistance of the molded product at a high load is improved. .

As a method for producing the maleimide copolymer (B), bulk polymerization is preferred.
The bulk polymerization referred to here includes polymerization in which a small amount of an organic solvent is present. The organic solvent is preferably one that does not polymerize itself, does not hinder the polymerization of the monomer, and can dissolve the maleimide copolymer (B). Specific examples of such an organic solvent include methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, acetophenone, benzene, toluene, ethylbenzene, xylene, tetrahydrofuran, N, N-dimethylformamide and the like.

The mass average molecular weight of the maleimide copolymer (B) is preferably 90000-200000. If the weight average molecular weight of the maleimide copolymer (B) is 90000 or more, the impact resistance of the molded product obtained by molding the reinforced thermoplastic resin composition of the present invention tends to be further improved. On the other hand, if the weight average molecular weight of the maleimide copolymer (B) is 200,000 or less, the moldability of the reinforced thermoplastic resin composition will be good, and the filler will be less prone to fluffing and will have excellent design. Tends to be easily obtained.
The mass average molecular weight of the maleimide copolymer (B) is a polystyrene-reduced mass average molecular weight measured by gel permeation chromatography (GPC).

  The content of the maleimide copolymer (B) is 5 to 20 masses when the total of the graft copolymer (A), the maleimide copolymer (B) and the polyamide resin (C) is 100 parts by mass. Part. When the content of the maleimide copolymer (B) is 5 parts by mass or more, the heat resistance at the time of high load, the coating adhesion, and the rigidity at the time of moisture absorption of the molded product obtained by molding the reinforced thermoplastic resin composition of the present invention. Will improve. On the other hand, when the content of the maleimide copolymer (B) is 20 parts by mass or less, the impact resistance of the molded product is improved.

(Polyamide resin (C))
Examples of the polyamide resin (C) include polyamides obtained from diamines and dicarboxylic acids.
Here, as the diamine, for example, ethylenediamine, diaminobutane, hexamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4- or 2,4,4-trimethylhexamethylenediamine, 1,3- or 1 , 4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexyl) methane, metaxylylenediamine, paraxylylenediamine, and the like, aliphatic, alicyclic, and aromatic diamines.
On the other hand, examples of the dicarboxylic acid include aliphatic, alicyclic, and aromatic dicarboxylic acids such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid.

  Examples of the polyamide resin (C) include polyamides obtained by ring-opening polymerization of lactams such as ε-caprolactam and ω-dodecalactam, 6-aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Polyamides obtained, polyamides thereof, mixed polyamides, polyamide elastomers having polyamide as a hard segment and polyether as a soft segment may be used.

  Among these, as the polyamide resin (C), polycaproamide (nylon 6), polydodecamide (nylon 12), polytetramethylene azide are industrially inexpensive and manufactured in large quantities and easily available. Pamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (nylon 610), and copolymers thereof, such as copolymers of nylon 6 and nylon 66 (in this case The copolymer is referred to as “nylon 6/66. The same applies hereinafter.), Nylon 6/610, nylon 6/12, nylon 66/12, nylon 6/66/610/12, and mixtures thereof. preferable. A polyamide obtained from bis (p-aminocyclohexyl) methane as a diamine and terephthalic acid or isophthalic acid as a dicarboxylic acid is also preferable as the polyamide resin (C).

  The polyamide resin (C) has a relative viscosity measured according to JIS K6810 of 1.8 to 3.0, preferably 1.8 to 2.7, and preferably 1.8 to 2.5. It is more preferable. When the relative viscosity of the polyamide resin (C) is 1.8 or more, the impact resistance of the molded product obtained by molding the reinforced thermoplastic resin composition of the present invention is improved. On the other hand, if the relative viscosity of the polyamide resin (C) is 3.0 or less, the interaction between the polyamide resin (C) and the inorganic filler (D) is well maintained, and the heat resistance of the molded product at the time of high load is maintained. Will improve. Moreover, when coating a molded article, it can suppress that an inorganic filler (D) fuzzs and a designability falls.

  The content of the polyamide resin (C) is 40 to 65 parts by mass when the total of the graft copolymer (A), the maleimide copolymer (B) and the polyamide resin (C) is 100 parts by mass. 50 to 65 parts by mass is preferable. When the content of the polyamide resin (C) is 40 parts by mass or more, the heat resistance and impact resistance at high load of the molded product obtained by molding the reinforced thermoplastic resin composition of the present invention are improved. In addition, it is possible to suppress fuzz when coating the molded product. On the other hand, if the content of the polyamide resin (C) is 65 parts by mass or less, the rigidity and paint adhesion of the molded product during moisture absorption are improved.

(Inorganic filler (D))
Examples of the inorganic filler (D) include inorganic fibers such as glass fibers and carbon fibers, those obtained by metal coating of the inorganic fibers, wollastonite, talc, mica, glass flakes, glass beads, potassium titanate, calcium carbonate. And inorganic materials such as magnesium carbonate, carbon black, and ketjen black, metals and alloys such as iron, copper, zinc, and aluminum, and fibers and powders of oxides thereof. Among these, fibrous inorganic fillers such as wollastonite, glass fiber, and carbon fiber are preferable because high rigidity can be obtained with a small amount of blend, and carbon fiber is particularly preferable from the balance of rigidity and impact resistance of the molded product. .
These inorganic fillers (D) may be used individually by 1 type, and 2 or more types may be mixed and used for them.

The surface of the inorganic filler (D) may be treated with a surface treatment agent such as a coupling agent (for example, a silane coupling agent or a titanate coupling agent).
When glass fibers or carbon fibers are used as the inorganic filler (D), these are coated with a thermoplastic resin such as an ethylene-vinyl acetate copolymer and a polyamide resin, and a thermosetting resin such as a polyurethane resin and an epoxy resin. Alternatively, it may be focused.

  Content of an inorganic filler (D) is 1-50 mass parts with respect to a total of 100 mass parts of a graft copolymer (A), a maleimide-type copolymer (B), and a polyamide resin (C), 5 It is preferably ~ 30 parts by mass. If content of an inorganic filler (D) is 1 mass part or more, the heat resistance and rigidity of the molded article which shape | molded the reinforced thermoplastic resin composition of this invention will improve. On the other hand, if the content of the inorganic filler (D) is 50 parts by mass or less, fuzz at the time of coating the molded product becomes inconspicuous, and the design property can be maintained well. Moreover, the moldability of the reinforced thermoplastic resin composition is improved.

(Other ingredients)
The reinforced thermoplastic resin composition of the present invention has other additives such as lubricants, pigments, dyes, oxidative degradation inhibitors, weathering agents, mold release agents, plasticizers and antistatic agents, as long as the physical properties are not impaired. It may contain.

(Production method)
The reinforced thermoplastic resin composition of the present invention includes, for example, a graft copolymer (A), a maleimide copolymer (B), a polyamide resin (C), and an inorganic filler (D), and others as necessary. However, it is not limited to this method.
Examples of the melt-kneading apparatus used for melt-kneading include a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roller, a kneader, and the like. Among these, a single-screw extruder and a twin-screw extruder are preferable from the viewpoint of versatility.

  As described above, the reinforced thermoplastic resin composition of the present invention includes the above-described graft copolymer (A), maleimide copolymer (B), polyamide resin (C), and inorganic filler (D )) Is contained in a specific amount, it is possible to obtain a molded product that is less likely to be deteriorated in rigidity during moisture absorption, is excellent in impact resistance, heat resistance during high loads, and is excellent in design during coating.

  The graft copolymer (A) contained in the reinforced thermoplastic resin composition is a rubbery polymer (a) comprising an acid-modified low molecular weight α-olefin copolymer and an ethylene-propylene-nonconjugated diene copolymer. Since the monomer mixture is formed by graft polymerization in the presence of, the compatibility with the polyamide resin (C) is excellent. Therefore, even if the reinforced thermoplastic resin composition of the present invention does not contain a compatibilizer, the graft copolymer (A) and the polyamide resin (C) are compatible with each other. You may contain. However, the smaller the content of the compatibilizer, the higher the heat resistance and impact resistance of a molded article obtained by molding the reinforced thermoplastic resin composition of the present invention at high load. Therefore, it is preferable that the reinforced thermoplastic resin composition of the present invention does not contain a compatibilizer.

<Molded product>
Molded articles obtained from the reinforced thermoplastic resin composition of the present invention include, for example, an injection molding method, an injection compression molding machine method, an extrusion method, a blow molding method, a vacuum molding method, a pressure molding method, a calendar molding method, and an inflation molding method. The reinforced thermoplastic resin composition is molded by a molding process such as the above. As the molding method, an injection molding method or an injection compression molding method is preferable because it is excellent in mass productivity and a molded product with high dimensional accuracy can be obtained.
The molded product obtained by the present invention is excellent in rigidity (especially rigidity at the time of moisture absorption), impact resistance, heat resistance at high load, and has a good paint appearance, so that it is an electrical component, electronic component, mechanical component and vehicle component. Can be suitably used.

Hereinafter, an example is shown concretely. The present invention is not limited to these examples.
In the following examples, the following components were used.

[Production of Graft Copolymer (A1)]
Ethylene-propylene-nonconjugated diene rubbery polymer (Mitsui Chemicals, "TP3180", ethylene / propylene / nonconjugated diene ratio (mass%) = 70/28/2) 100 parts by mass of n-hexane 566 After dissolving in parts by mass, 12 parts by mass of acid-modified polyethylene (manufactured by Mitsui Chemicals, “High Wax 2203A”, viscosity average molecular weight: 2700, acid value: 30) is added, and 4.5 parts by mass of oleic acid The polymer solution was prepared by complete dissolution. Separately, an aqueous potassium hydroxide solution in which 0.9 parts by mass of potassium hydroxide was dissolved in 700 parts by mass of distilled water was prepared and heated to 60 ° C. The polymer solution was gradually added to the aqueous potassium hydroxide solution to emulsify, and then stirred with a homomixer to obtain a latex. Next, 1.5 parts by mass of divinylbenzene and 1.0 part by mass of di-t-butylperoxytrimethylcyclohexane are added to 100 parts by mass of the ethylene-propylene-nonconjugated diene rubber polymer to the latex, The reaction was carried out at 120 ° C. for 1 hour to obtain a latex of rubbery polymer (a) (gel content: 70%, average particle size: 0.48 μm).
70 parts by mass of latex of the obtained rubber polymer (a) (in terms of solid content), 155 parts by mass of distilled water (including water in ethylene-propylene-nonconjugated diene rubber polymer latex), pyrroline 0.15 parts by mass of sodium acid, 0.006 parts by mass of ferrous sulfate heptahydrate and 0.35 parts by mass of fructose were charged, and the internal temperature was kept at 80 ° C. To this, a monomer mixture consisting of 21 parts by mass of styrene and 9 parts by mass of acrylonitrile and 0.6 parts by mass of cumene hydroperoxide were simultaneously added dropwise from another supply port over 140 minutes for polymerization. . During this time, the internal temperature was controlled to be constant at 80 ° C. After completion of dropping, the mixture was further kept at 80 ° C. for 100 minutes and then cooled to complete the graft polymerization to obtain a reaction product latex.
The obtained latex of the reactive organism was coagulated with an aqueous sulfuric acid solution, washed with water, and dried to obtain a graft copolymer (A1).

[Production of Graft Copolymer (A2)]
In a 20 L polymerization reactor equipped with a stirrer, 170 parts by mass of distilled water, 65 parts by mass of polybutadiene latex (gel content: 95%, average particle size: 0.3 μm) (in terms of solid content), and 70 by styrene 35 parts by weight of a monomer mixture consisting of 30% by weight and 30% by weight of acrylonitrile, 1 part by weight of disproportionated potassium rosinate, 0.01 parts by weight of sodium hydroxide, 0.45 parts by weight of sodium pyrophosphate, sulfuric acid First, 0.01 parts by mass of ferrous iron, 0.57 parts by mass of dextrose, 0.07 parts by mass of t-dodecyl mercaptan, and 1.0 parts by mass of cumene hydroperoxide were charged, and the reaction was started at 60 ° C. The temperature was raised to 75 ° C. in the middle, and after 2 hours and a half, the emulsion graft polymerization was completed to obtain a reaction product latex.
The obtained reactive biological latex was coagulated with an aqueous sulfuric acid solution, washed with water, and dried to obtain a graft copolymer (A2).

[Production of Maleimide Copolymer (B)]
After a 20 L polymerization reactor equipped with a stirrer was purged with nitrogen, the polymerization reactor was mixed with 15 parts by mass of acrylonitrile, 54 parts by mass of styrene, and 31 parts by mass of N-phenylmaleimide, and 30 parts by mass of methyl ethyl ketone. , And a mixed liquid consisting of 0.103 parts by mass of 1,1′-azobis (cyclohexane-1-carbonitrile) as a polymerization initiator were continuously supplied dropwise to a polymerization reactor from separate pipes. The copolymerization reaction was carried out under conditions of a polymerization temperature of 100 ° C. and a residence time of 90 minutes.
Next, the polymerization reaction liquid obtained by this reaction was continuously withdrawn by a gear pump provided at the bottom of the polymerization reactor, and the polymerization reaction liquid was allowed to stay in a heat exchanger maintained at 150 ° C. for about 20 minutes. Then, it introduce | transduces into the 2 vent type 30mm twin-screw extruder controlled to the barrel temperature of 230 degreeC, and is volatilized by the 1st vent part of the atmospheric pressure in the twin-screw extruder, and the 2nd vent part of 0.0027 MPa. The components were devolatilized. And it pelletized with the devolatilized pelletizer, and the pellet of the maleimide-type copolymer (B) was obtained.
The mass average molecular weight of the obtained maleimide copolymer (B) was measured by a standard PC (polystyrene) conversion method using THF (tetrahydrofuran) as a solvent with a GPC measuring apparatus (manufactured by Tosoh Corporation). As a result, the weight average molecular weight of the maleimide copolymer (B) was 165000.

[Polyamide resin (C)]
The following polyamide resins (C1) to (C3) were used as the polyamide resin (C).
Polyamide resin (C1): Nylon 6 (manufactured by Ube Industries, “1011FB”, relative viscosity = 2.10).
Polyamide resin (C2): Nylon 6 (manufactured by Ube Industries, “1013B”, relative viscosity = 2.56).
Polyamide resin (C3): Nylon 6 (manufactured by Ube Industries, “1022B”, relative viscosity = 3.57).
The relative viscosities of the polyamide resins (C1) to (C3) are values measured in accordance with JIS K6810.

[Inorganic filler (D)]
As the inorganic filler (D), carbon fiber (manufactured by Mitsubishi Rayon Co., Ltd., “TR06NE”) was used.

[Production of styrene copolymer]
A monomer mixture 100 comprising 120 parts by mass of distilled water, 0.003 parts by mass of sodium alkylbenzenesulfonate, 68.0% by mass of styrene and 32.0% by mass of acrylonitrile was added to a 20 L polymerization reactor equipped with a stirrer. Add part by weight, 0.5 part by weight of t-dodecyl mercaptan, 0.15 part by weight of benzoyl peroxide and 0.5 part by weight of calcium phosphate, and after suspension polymerization at 110 ° C. for 10 hours, cool. Polymerization was completed. After washing with water, it was dried to obtain a styrene copolymer.
It was 158000 when the mass average molecular weight of the obtained styrene-type copolymer was measured like the maleimide-type copolymer (B).

[Production of acid-modified styrene copolymer]
A 20 L polymerization reactor equipped with a stirrer was charged with 200 parts by mass of distilled water, 0.3 part by mass of potassium persulfate, and 2 parts by mass of sodium dodecylbenzenesulfonate, and the temperature was adjusted to 65 ° C. A monomer mixture consisting of 71 parts by mass of styrene, 24 parts by mass of acrylonitrile, 5 parts by mass of methacrylic acid, and 0.4 parts by mass of t-dodecyl mercaptan was added dropwise thereto over 5 hours to carry out polymerization. After completion of the dropwise addition, the temperature was raised to 70 ° C., held for another 60 minutes, and then cooled to complete graft polymerization to obtain a reaction product latex.
The reactive latex obtained was coagulated with calcium acetate, washed with water, and then dried to obtain an acid-modified styrene copolymer.

[Examples 1-8, Comparative Examples 1-7]
Graft copolymer (A1, A2), maleimide copolymer (B), polyamide resin (C1, C2, C3), inorganic filler (D), styrene copolymer, acid-modified styrene copolymer Mixing with the composition (parts by mass) shown in Tables 1 and 2 and melt-kneading at 270 ° C. using a 30 mm twin-screw extruder (“KTX-30” manufactured by Kobe Steel, Ltd.), a pellet-shaped reinforced thermoplastic resin composition I got a thing.
The obtained reinforced thermoplastic resin composition is injection-molded to create various molded products (test pieces). The tensile properties, rigidity, heat resistance, impact resistance, rigidity after moisture absorption, paint adhesion, and design are Evaluation was made by the following method. The evaluation results are shown in Tables 1 and 2.

[Tensile properties]
Based on the ISO 527 test method, tensile strength (MPa) and tensile elongation (%) were measured under the conditions of a measurement temperature of 23 ° C. and a specimen thickness of 4 mm.

[rigidity]
Based on ISO test method 178, bending strength (MPa) and bending elastic modulus (MPa) were measured under the conditions of a measurement temperature of 23 ° C. and a specimen thickness of 4 mm.

[Heat-resistant]
In accordance with ISO test method 75, the deflection temperature under load (° C.) was measured under the conditions of 1.83 MPa, 4 mm, and the flatwise method, and this was defined as heat resistance under high load.

[Shock resistance]
Based on ISO test method 179, Charpy impact strength (kJ / m ² ) with V notch was measured under the conditions of a measurement temperature of 23 ° C. and a specimen thickness of 4 mm.

[Rigidity when absorbing moisture]
In accordance with ISO test method 291, the test piece was conditioned until it reached equilibrium at 23 ° C. and 50% RH, and then measured in accordance with ISO test method 178 at a measurement temperature of 23 ° C. and a test piece thickness of 4 mm. The bending modulus of elasticity (MPa) was defined as the rigidity at the time of moisture absorption.

[Coating adhesion]
An acrylic paint is applied to a 100 mm × 100 mm test piece (thickness 2 mm) using an airbrush so that the film thickness is about 30 μm, dried at 60 ° C. for 30 minutes, and a coating film is formed on the test piece. Formed.
Next, a cut was made on the surface of the coating film to reach the test piece with a cutter, 100 grids were formed at intervals of 1 mm, and a cellophane tape was brought into close contact, and then peeled off in the 180 ° direction. The number of grids remaining on the surface of the coating film after the peel test was counted, and coating adhesion was evaluated according to the following evaluation criteria.
A: The number of grids is 100.
○: The number of grids is 95 or more and less than 100.
Δ: The number of grids is 85 or more and less than 95.
X: The number of grids is less than 85.

[Creativity]
In the same manner as the coating adhesion, an acrylic paint was applied to the test piece to form a coating film. At this time, the appearance of the test piece was visually observed, the number of fluffs due to the protrusion of the inorganic filler (D) was counted, and the design properties were evaluated according to the following evaluation criteria.
A: The number of fluff is 0.
○: The number of fluffs is 1 or more and less than 5.
Δ: The number of fluffs is 5 or more and less than 10.
X: The number of fluff is 10 or more.

  As is apparent from Table 1, the molded article (test piece) obtained from the reinforced thermoplastic resin composition of each example has a small decrease in rigidity at the time of moisture absorption, impact resistance, and heat resistance at high load. In addition, it was excellent in design at the time of painting.

On the other hand, as shown in Table 2, the molded product obtained from the reinforced thermoplastic resin composition of Comparative Example 1 having a content of the polyamide resin (C2) as small as 35 parts by mass is heat resistant under high load, It was inferior in impact resistance and design.
The molded product obtained from the reinforced thermoplastic resin composition of Comparative Example 2 having a high polyamide resin (C2) content of 70 parts by mass had low rigidity during moisture absorption and poor paint adhesion.
The molded product obtained from the reinforced thermoplastic resin composition of Comparative Example 3 having a large content of the maleimide copolymer (B) of 30 parts by mass was inferior in impact resistance.
A molded product obtained from the reinforced thermoplastic resin composition of Comparative Example 4 using a polyamide resin (C3) having a relative viscosity of 3.57 was inferior in heat resistance and design at high loads.
A molded product obtained from the reinforced thermoplastic resin composition of Comparative Example 5 using a styrene copolymer in place of the maleimide copolymer (B) has low rigidity at the time of moisture absorption and heat resistance at high loads. It was inferior.
The molded product obtained from the reinforced thermoplastic resin composition of Comparative Example 6 that did not contain the maleimide copolymer (B) had low rigidity during moisture absorption and was inferior in paint adhesion.
Comparative Example 7 using a graft copolymer (A2) produced using a diene rubbery polymer not containing an acid-modified low molecular weight α-olefin copolymer instead of the graft copolymer (A1) Molded articles obtained from the reinforced thermoplastic resin composition were inferior in heat resistance at high loads.

Claims (2)

In the presence of 40 to 75 parts by mass of a rubbery polymer (a) composed of an acid-modified low molecular weight α-olefin copolymer and an ethylene-propylene-nonconjugated diene copolymer having a viscosity average molecular weight of 1000 to 9000, 25 to 60 parts by mass of a monomer mixture containing 60 to 95% by mass of vinyl group (b) and 5 to 40% by mass of vinyl cyanide (c) (however, the total of the rubber polymer (a) is 100% by mass) 20-40 parts by mass of the graft copolymer (A) obtained by graft polymerization,
A maleimide copolymer (5) to 50% by mass of a maleimide monomer (d) and 50 to 95% by mass of another monomer copolymerizable with the maleimide monomer (d) ( B) 5 to 20 parts by mass;
50 to 65 parts by mass of a polyamide resin (C) having a relative viscosity of 1.8 to 2.7 ,
The inorganic filler (D) is contained in an amount of 1 to 50 parts by mass with respect to a total of 100 parts by mass of the graft copolymer (A), the maleimide copolymer (B) and the polyamide resin (C). Reinforced thermoplastic resin composition. The reinforced thermoplastic resin composition according to claim 1, wherein the maleimide copolymer (B) has a mass average molecular weight of 90000-200000 .