JP2016060863A - Thermoplastic resin composition for supercritical foam molding and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition for supercritical foam molding solving a problem of corrosion to a mold cavity face during supercritical foam molding.SOLUTION: There is provided a thermoplastic resin composition for supercritical foam molding containing total 100 pts.mass of a polycarbonate resin (A) of 90 to 20 pts.mass and a styrenic resin (B) of 10 to 80 pts.mass and 0.01 to 2 pts.mass of an ester compound of saturated aliphatic carboxylic acid having 10 to 22 carbon atoms and monovalent aliphatic alcohol (C).SELECTED DRAWING: None

Description

  The present invention relates to a thermoplastic resin composition for supercritical foam molding and a molded article, and more specifically, an alloy thermoplastic resin of polycarbonate resin and styrene resin with reduced corrosiveness to a mold cavity surface during supercritical molding. The present invention relates to a composition and a molded article obtained by supercritical foam molding using the composition.

  Polycarbonate resin is a resin excellent in heat resistance, mechanical properties, and electrical characteristics, and is widely used in, for example, automotive materials, electrical / electronic equipment materials, housing materials, and other parts manufacturing materials in industrial fields. . In particular, flame retardant polycarbonate / styrene resin alloys are suitable for use as electrical / electronic equipment such as computers, notebook computers, various portable terminals, printers, copiers, OA / information equipment, etc. Has been.

  In recent years, these devices have been rapidly reduced in size and weight, and a foam molding method is being adopted in order to reduce the amount of resin used and reduce the weight. As foam molding, there is a method of manufacturing using a chemical foaming agent or a physical foaming agent, but the chemical foaming method is expensive because of the use of the foaming agent, and also due to the decomposition residue of the foaming agent remaining in the foam. There are problems such as discoloration of foam, generation of odor, and contamination of molding machine by chemical foaming agent.

  On the other hand, the gas foaming method using a physical foaming agent is a method of foam molding by melting a resin with a molding machine, supplying a low-boiling organic compound such as butane and kneading, and then releasing it into a low-pressure region. Since the low-boiling organic compound obtained has an affinity for the resin, it has excellent solubility and a high-magnification foam can be obtained. However, these foaming agents are expensive, and low-boiling organic compounds have dangers such as flammability.

  In order to solve such problems, a method has been proposed in which an inert gas such as nitrogen gas or carbon dioxide gas that is clean and inexpensive is used as a blowing agent. However, these inert gases have low solubility because they have a low affinity with the resin, and the resulting foam has a large and uneven cell diameter and low cell density. There's a problem.

Patent Document 1 describes a technique for obtaining a foam having a very fine cell diameter and a large cell density by using a supercritical fluid as a foaming agent and impregnating the supercritical fluid with a resin. In this supercritical foam molding, the supercritical liquid has excellent solubility close to liquid and excellent diffusibility close to gas, so the solubility in the resin is high, and the diffusion rate in the resin is also large. It becomes possible to impregnate the foaming agent in the resin in a short time.
However, in such a method in which a supercritical fluid is added to a molten resin and foamed, a problem of mold corrosion tends to occur. This problem occurs even with a polycarbonate resin composition that is used for normal injection molding and has no problem of mold corrosion, particularly rusting on the mold cavity surface. A serious problem arises.

  In the invention described in Patent Document 2, it has been proposed to mix a mold release agent having a thermal decomposition temperature of 280 ° C. or higher due to the problem of mold corrosion, but the purpose is to reduce corrosive gas, The effect of reducing the corrosion is manifested in the mold gas vent, and there was no effect on reducing the corrosion in an environment where the corrosion on the mold cavity surface occurred.

US Pat. No. 5,158,986 JP 2013-53271 A

  The present invention was devised in view of the above-mentioned problems of the prior art, and solves the problem of corrosion on the mold cavity surface during supercritical foam molding for an alloy resin of polycarbonate resin and styrene resin. An object of the present invention is to provide a thermoplastic resin composition for supercritical foam molding.

As a result of intensive studies in order to achieve the above-mentioned problems, the present inventors have found that a saturated aliphatic carboxylic acid having 10 to 22 carbon atoms and a monovalent aliphatic in an alloy resin of a polycarbonate resin and a styrene resin. The present inventors have found that a thermoplastic resin composition containing a specific amount of an ester compound with alcohol solves the problem of corrosion on the mold cavity surface during supercritical foam molding, and has completed the present invention.
The present invention provides the following supercritical foam molding thermoplastic resin composition and molded article.

[1] Saturated aliphatic carboxylic acid having 10 to 22 carbon atoms and monovalent fat with respect to 100 parts by mass in total of 90 to 20 parts by mass of polycarbonate resin (A) and 10 to 80 parts by mass of styrene resin (B) A thermoplastic resin composition for supercritical foam molding, comprising 0.01 to 2 parts by mass of an ester compound (C) with an aliphatic alcohol.
[2] The thermoplastic resin composition for supercritical foam molding as described in [1] above, wherein the styrene resin (B) is an ABS resin and / or an AS resin.
[3] The supercritical foam molding thermoplastic resin composition according to the above [1] or [2], wherein the ester compound (C) is stearyl stearate and / or behenyl behenate.
[4] Further, the phosphorous flame retardant (D) is contained in an amount of 3 to 30 parts by mass with respect to a total of 100 parts by mass of the polycarbonate resin (A) and the styrene resin (B). The thermoplastic resin composition for supercritical foam molding according to any one of the above.
[5] The thermoplastic resin composition for supercritical foam molding as described in [4] above, wherein the phosphorus flame retardant (D) is a condensed phosphate ester and / or a phosphazene compound.
[6] Further, at least one selected from the aromatic vinyl monomer (e2), the vinyl cyanide monomer (e3) and the methacrylic acid ester monomer (e4) is added to the rubbery polymer (e1). The graft copolymer (E) obtained by graft polymerization is contained in an amount of 0.5 to 20 parts by mass with respect to a total of 100 parts by mass of the polycarbonate resin (A) and the styrene resin (B). [5] The thermoplastic resin composition for supercritical foam molding according to any one of [5].
[7] The supercritical foam molding thermoplastic resin composition as described in any one of [1] to [6] above, wherein the gas used for supercritical foaming is nitrogen.
[8] A molded article obtained by supercritical foam molding using the thermoplastic resin composition for supercritical foam molding according to any one of [1] to [7].

  The thermoplastic resin composition for supercritical foam molding of the present invention can solve the problem of corrosion on the mold cavity surface during supercritical foam molding.

It is a figure which shows the structure of the metal mold | die used for evaluation of metal mold | die corrosivity in an Example.

Hereinafter, although an embodiment, an example thing, etc. are shown and explained in detail about the present invention, the present invention is limited to an embodiment, an example, etc. shown below and is not interpreted.
In the present specification, unless otherwise specified, “to” is used in a sense that includes numerical values described before and after it as a lower limit value and an upper limit value.

  The thermoplastic resin composition for supercritical foam molding of the present invention has 10 to 10 carbon atoms with respect to 100 parts by mass in total of 90 to 20 parts by mass of the polycarbonate resin (A) and 10 to 80 parts by mass of the styrene resin (B). It contains 0.01 to 2 parts by mass of an ester compound (C) of 22 saturated aliphatic carboxylic acids and a monovalent aliphatic alcohol.

[Polycarbonate resin (A)]
Examples of the polycarbonate resin (A) include an aromatic polycarbonate resin, an aliphatic polycarbonate resin, and an aromatic-aliphatic polycarbonate resin, preferably an aromatic polycarbonate resin, specifically, an aromatic dihydroxy compound. A thermoplastic aromatic polycarbonate polymer or copolymer obtained by reacting with phosgene or a diester of carbonic acid is used.

  Aromatic dihydroxy compounds include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), tetramethylbisphenol A, α, α'-bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol 4,4′-dihydroxydiphenyl and the like. Further, in order to improve flame retardancy, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the aromatic dihydroxy compound described above, a polymer having both ends phenolic OH groups having a siloxane structure, or an oligomer thereof is used. Also good.

  As a preferable example of the polycarbonate resin (A), 2,2-bis (4-hydroxyphenyl) propane or 2,2-bis (4-hydroxyphenyl) propane and another aromatic dihydroxy compound are used in combination as a dihydroxy compound. A polycarbonate resin is mentioned.

  The polycarbonate resin may be a homopolymer composed of one type of repeating unit or a copolymer having two or more types of repeating units. At this time, the copolymer can be selected from various copolymerization forms such as a random copolymer and a block copolymer.

  The molecular weight of the polycarbonate resin (A) is not limited, but it is a viscosity average molecular weight (Mv) converted from the solution viscosity measured at a temperature of 20 ° C. using methylene chloride as a solvent, preferably 10,000 to 40,000. More preferably, it is 14,000-32,000. When the viscosity average molecular weight is within this range, the resulting resin composition has good moldability in supercritical foam molding, and a molded product having high mechanical strength is easily obtained. The most preferable molecular weight range of the polycarbonate resin (A) is 16,000 to 30,000.

In the present invention, the viscosity average molecular weight (Mv) of the polycarbonate resin (A) is determined by measuring the viscosity of the methylene chloride solution of the polycarbonate resin at 20 ° C. using an Ubbelohde viscometer. Is a value calculated from the following Schnell viscosity equation.
[Η] = 1.23 × 10 ⁻⁴ Mv ^0.83

  The production method of the polycarbonate resin (A) is not particularly limited, and a polycarbonate resin produced by any of the phosgene method (interfacial polymerization method) and the melting method (transesterification method) can be used. Moreover, the polycarbonate resin which performed the post-process which adjusts the amount of terminal OH groups to the polycarbonate resin manufactured by the melting method is also preferable.

  Moreover, the polycarbonate resin (A) may contain a polycarbonate oligomer. The viscosity average molecular weight [Mv] of this polycarbonate oligomer is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9,000 or less. Furthermore, the polycarbonate ligomer contained is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

  The polycarbonate resin (A) is not limited to the virgin raw material, but may be an aromatic polycarbonate resin regenerated from a used product, that is, a so-called material recycled aromatic polycarbonate resin. Used products include optical recording media such as optical disks, light guide plates, automobile window glass and automobile headlamp lenses, vehicle transparent members such as windshields, containers such as water bottles, glasses lenses, soundproof walls and glass windows, waves A building member such as a plate is preferred. In addition, as the recycled polycarbonate resin, non-conforming product, pulverized product obtained from sprue or runner, or pellets obtained by melting them can be used.

[Styrene resin (B)]
The thermoplastic resin composition of the present invention contains a styrene resin (B). By containing the styrene resin (B), fluidity (moldability) and foamability in supercritical foam molding of the thermoplastic resin composition can be improved.
Here, the styrenic resin (B) is an aromatic vinyl monomer (b1) alone or another vinyl monomer (b2, copolymerizable with the aromatic vinyl monomer (b1) as necessary. It is a resin obtained by polymerizing one or more selected from b4) and a rubbery polymer (b3).

Examples of the aromatic vinyl monomer (b1) used in the styrene resin (B) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert. -Styrene derivatives such as butyl styrene, vinyl naphthalene, methoxy styrene, monobromo styrene, dibromo styrene, fluoro styrene, tribromo styrene and the like are mentioned, and styrene is particularly preferable.
These may be used alone or in combination of two or more.

  The other vinyl monomer copolymerizable with these aromatic vinyl monomers (b1) is preferably a vinyl cyanide monomer (b2), and examples thereof include acrylonitrile and methacrylonitrile.

Other monomers (b4) other than vinyl cyanide monomer (b2) that can be copolymerized include aryl esters of acrylic acid such as phenyl acrylate and benzyl acrylate; methyl acrylate, ethyl acrylate, propyl acrylate Alkyl esters of acrylic acid such as butyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate, dodecyl acrylate; aryl methacrylates such as phenyl methacrylate, benzyl methacrylate; methyl methacrylate, ethyl methacrylate, propyl Methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate Methacrylic acid alkyl esters such as octyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate; epoxy group-containing methacrylic acid esters such as glycidyl methacrylate; maleimide monomers such as maleimide, N-methylmaleimide, N-phenylmaleimide; acrylic acid, Examples include α, β-unsaturated carboxylic acids such as methacrylic acid, maleic acid, maleic anhydride, phthalic acid, and itaconic acid, and anhydrides thereof. Preferred are alkyl acrylates and alkyl methacrylates.
One of these other monomers (b4) may be used alone, or two or more thereof may be mixed and used.

The rubbery polymer (b3) copolymerizable with the aromatic vinyl monomer (b1) is preferably a rubber having a glass transition temperature of 10 ° C. or lower. Specific examples of such rubbery polymers include diene rubber, acrylic rubber, ethylene / propylene rubber, silicone rubber, polyorganosiloxane rubber component and polyalkyl (meth) acrylate rubber component so that they cannot be separated from each other. Composite rubber (IPN type rubber) having a structure entangled with each other is preferable, and diene rubber, acrylic rubber and the like are preferable.
In this specification, “(meth) acrylate” refers to one or both of “acrylate” and “methacrylate”, and the same applies to “(meth) acryl” and “(meth) acrylo”.

Examples of the diene rubber include polybutadiene, styrene-butadiene random copolymer and block copolymer, acrylonitrile-butadiene copolymer, polyisoprene, butadiene-isoprene copolymer, and ethylene-propylene-hexadiene copolymer. Examples thereof include a copolymer of ethylene, propylene and a non-conjugated diene, a lower alkyl ester copolymer of butadiene- (meth) acrylic acid, a lower alkyl ester copolymer of butadiene-styrene- (meth) acrylic acid, and the like.
Examples of the lower alkyl ester of (meth) acrylic acid include methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate.
The proportion of the lower alkyl ester of (meth) acrylic acid in the lower alkyl ester copolymer of butadiene- (meth) acrylic acid or the lower alkyl ester copolymer of butadiene-styrene- (meth) acrylic acid is that of the rubber polymer. It is preferable that it is 30 mass% or less of quantity.

  Examples of the acrylic rubber include acrylic acid alkyl ester rubber, and the carbon number of the alkyl group is preferably 1-8. Specific examples of the alkyl acrylate include ethyl acrylate, butyl acrylate, hexyl acrylate and the like. An ethylenically unsaturated monomer may optionally be used in the acrylic acid alkyl ester rubber. Specific examples of such compounds include di (meth) acrylate, divinylbenzene, trivinylbenzene, triallyl cyanurate, allyl (meth) acrylate, butadiene, isoprene and the like. Examples of the acrylic rubber include a core-shell type polymer having a crosslinked diene rubber as a core.

  As for these rubbery polymers (b3), one kind may be used alone, or two or more kinds may be mixed and used.

  The styrene resin (B) is composed of 50 to 100% by mass of the aromatic vinyl monomer component (b1), 0 to 30% by mass of the vinyl cyanide monomer component (b2), and the rubbery polymer component (b3). It is preferably composed of 0 to 30% by mass, other monomer component (b4) 0 to 30% by mass, aromatic vinyl monomer component (b1) 45 to 80% by mass, vinyl cyanide monomer component ( b2) 10-30% by mass, rubbery polymer component (b3) 10-25% by mass, other monomer component (b4) 0-40% by mass, more preferably aromatic vinyl monomer component (B1) 55 to 70% by mass, vinyl cyanide monomer component (b2) 15 to 25% by mass, rubbery polymer component (b3) 15 to 20% by mass, other monomer components (b4) 0 to More preferably, it consists of 5% by mass.

Specific examples of the styrenic resin (B) used in the present invention include, for example, a homopolymer of styrene, a copolymer of styrene and (meth) acrylonitrile, and a copolymer of styrene and an alkyl (meth) acrylate. Copolymers, copolymers of styrene and (meth) acrylonitrile and other copolymerizable monomers, graft copolymers obtained by polymerizing styrene in the presence of rubber, styrene and (meth) in the presence of rubber Preferable examples include graft copolymers obtained by graft polymerization with acrylonitrile.
More specifically, polystyrene, high impact polystyrene (HIPS), acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), acrylonitrile-butadiene-styrene copolymer. Polymer (ABS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), styrene-butadiene-styrene copolymer (SBS resin), hydrogenated styrene-butadiene-styrene copolymer (hydrogenated) SBS), hydrogenated styrene-isoprene-styrene copolymer (SEPS), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-ethylenepropylene rubber-styrene copolymer (AES resin) and Resin such as styrene-IPN type rubber copolymer or this Mixtures of al and the like. Further, it may have stereoregularity such as syndiotactic polystyrene. In addition, aromatic vinyl monomers can be widely used in place of the above styrene.

  Among these, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), acrylonitrile-ethylenepropylene system A rubber-styrene copolymer (AES resin) is preferred.

  Examples of the method for producing these styrene resins (B) include known methods such as an emulsion polymerization method, a solution polymerization method, a suspension polymerization method, and a bulk polymerization method. As the styrene resin (B), a bulk polymerization method is used. Is preferable because it is excellent in wet heat stability and thermal stability.

  These styrenic resins (B) may be used alone or in a combination of two or more.

  The content of the styrene resin (B) is 10 to 80 parts by mass, preferably 60 parts by mass or less, more preferably 50, based on a total of 100 parts by mass of the polycarbonate resin (A) and the styrene resin (B). Parts by mass or less, more preferably 45 parts by mass, particularly preferably 40 parts by mass or less, and most preferably 35 parts by mass or less, preferably 15 parts by mass or more, more preferably 20 parts by mass or more, still more preferably 23 parts by mass or more, In particular, 25 parts by mass or more is preferable. If the content of the styrenic resin body (B) exceeds 80 parts by mass, the strength tends to be unsatisfactory, and if it is less than 10 parts by mass, the fluidity improving effect and foaming properties are insufficient.

[Ester compound (C) of saturated aliphatic carboxylic acid having 10 to 22 carbon atoms and monovalent aliphatic alcohol]
The supercritical foam molding thermoplastic resin composition of the present invention contains an ester compound (C) of a saturated aliphatic carboxylic acid having 10 to 22 carbon atoms and a monovalent aliphatic alcohol.

  Examples of the saturated aliphatic carboxylic acid having 10 to 22 carbon atoms constituting the ester compound (C) include saturated monovalent, divalent or trivalent aliphatic carboxylic acids. Here, the aliphatic carboxylic acid includes alicyclic carboxylic acid.

Examples of saturated aliphatic carboxylic acids having 10 to 22 carbon atoms include decanoic acid (capric acid), undecanoic acid, dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), pentadecanoic acid, hexadecanoic acid (palmitic acid), and heptadecane. Branched chains such as saturated linear aliphatic monocarboxylic acids such as acid (margaric acid), octadecanoic acid (stearic acid), nonadecanoic acid, eicosanoic acid (arachinic acid), docosanoic acid (behenic acid), isopalmitic acid, isostearic acid Saturated aliphatic monocarboxylic acids having an aliphatic carboxylic acid, and aliphatic dicarboxylic acids such as sebacic acid and dodecanedioic acid.
Among these, an aliphatic monocarboxylic acid having 10 to 25 carbon atoms is preferable, and specific examples thereof include palmitic acid, stearic acid, behenic acid and the like.

As the alcohol constituting the saturated aliphatic carboxylic acid and ester, a monovalent aliphatic alcohol is used. Examples of the monovalent aliphatic alcohol include saturated or unsaturated monohydric alcohols, and these alcohols may have a substituent such as a fluorine atom or an aryl group. Among these alcohols, monovalent saturated alcohols having 25 or less carbon atoms are preferable, and aliphatic saturated monohydric alcohols having 10 to 22 carbon atoms are particularly preferable. Here, aliphatic includes alicyclic compounds.
Specific examples of these alcohols include decyl alcohol (capryl alcohol), undecyl alcohol, dodecyl alcohol (lauryl alcohol), tetradecyl alcohol (myristyl alcohol), pentadecyl alcohol, hexadecyl alcohol (palmityl alcohol), heptacil. Preferable examples include alcohol, octadecyl alcohol (stearyl alcohol), nonadecyl alcohol, aralkyl alcohol, docosanol (behenyl alcohol) and the like.

  Specific examples of the ester compound (C) of a saturated aliphatic carboxylic acid having 10 to 22 carbon atoms and a monovalent aliphatic alcohol include stearic acid stearate, behenate stearate, tridecyl stearate, behenate behenate, behen Preferable examples include acid stearate and myristyl myristate. Among these, stearic acid stearate and behenate behenate are particularly preferable.

  Content of ester compound (C) is 0.01-2 mass parts with respect to a total of 100 mass parts of polycarbonate resin (A) and styrene-type resin (B), Preferably it is 0.05 mass part or more, More preferably, it is 0.1 parts by mass or more, preferably 1.5 parts by mass or less, more preferably 1 part by mass or less, still more preferably 0.8 parts by mass or less, especially 0.6 parts by mass or less, especially 0.5 parts by mass or less, particularly preferably 0.4 parts by mass or less. When the content of the ester compound (C) is less than or equal to the lower limit of the above range, the effect of improving the corrosiveness to the mold cavity surface during supercritical molding becomes insufficient, and the content exceeds the upper limit of the above range. In this case, mold contamination (mold deposit) is likely to occur during supercritical molding, and the thermal stability of the resin composition is lowered.

[Phosphorus flame retardant (D)]
The thermoplastic resin composition for supercritical foam molding of the present invention preferably contains a phosphorus-based flame retardant (D). By containing a phosphorus flame retardant (D), the flame retardancy of a molded product obtained by supercritical foam molding can be improved.
The phosphorus-based flame retardant (D) is a compound containing phosphorus in the molecule, and may be a low molecule, an oligomer, or a polymer. The condensed phosphate compound represented by the formula (1) and the phosphazene compounds represented by the general formulas (2) and (3) are particularly preferable.

-Condensed phosphate ester compound The condensed phosphate ester compound represented by the above general formula (1) may be a mixture of compounds having different numbers of k, and in the case of a mixture of condensed phosphate esters having different k K is the average of their mixture. k is usually an integer of 0 to 5, and in the case of a mixture of compounds having different k numbers, the average k number is preferably 0.5 to 2, more preferably 0.6 to 1.5, and even more preferably. Is in the range of 0.8 to 1.2, particularly preferably 0.95 to 1.15.

X ¹ represents a divalent arylene group such as resorcinol, hydroquinone, bisphenol A, 2,2′-dihydroxybiphenyl, 2,3′-dihydroxybiphenyl, 2,4′-dihydroxybiphenyl, 3,3 ′. -Dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1, Divalent derivatives derived from dihydroxy compounds such as 6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene and 2,7-dihydroxynaphthalene It is a group. Of these, divalent groups derived from resorcinol, bisphenol A, and 3,3′-dihydroxybiphenyl are particularly preferable.

  Further, p, q, r and s in the general formula (1) each represent 0 or 1, and 1 is particularly preferable.

R ¹ , R ² , R ³ and R ⁴ each represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted with an alkyl group. Examples of such aryl groups include phenyl group, cresyl group, xylyl group, isopropylphenyl group, butylphenyl group, tert-butylphenyl group, di-tert-butylphenyl group, and p-cumylphenyl group. Group, cresyl group and xylyl group are more preferred.

As a specific example of the condensed phosphate ester compound represented by the general formula (1),
Triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), cresyl diphenyl phosphate (CDP), 2-ethylhexyl diphenyl phosphate (EHDP), tert-butylphenyl diphenyl phosphate, bis- ( aromatic phosphates such as tert-butylphenyl) phenyl phosphate, tris- (tert-butylphenyl) phosphate, isopropylphenyldiphenyl phosphate, bis- (isopropylphenyl) diphenyl phosphate, tris- (isopropylphenyl) phosphate;
Condensed phosphate esters such as resorcinol bis-diphenyl phosphate (RDP), resorcinol bis-dixylenyl phosphate (RDX), bisphenol A bis-diphenyl phosphate (BDP), biphenyl bis-diphenyl phosphate;
Etc.

  The acid value of the condensed phosphate ester compound represented by the general formula (1) is preferably 0.2 mgKOH / g or less, more preferably 0.15 mgKOH / g or less, still more preferably 0.1 mgKOH or less, Especially preferably, it is 0.05 mgKOH / g or less. The lower limit of the acid value can be substantially zero. On the other hand, the content of the half ester is more preferably 1.1 parts by mass or less, and still more preferably 0.9 parts by mass or less. When the acid value exceeds 0.2 mgKOH / g or the half ester content exceeds 1.5 mg, the thermal stability and hydrolysis resistance of the polycarbonate resin composition of the present invention are reduced.

  As the phosphoric ester compound, in addition to the above, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (2,3-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (2,4-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, containing phosphate ester moiety Naturally, polyester resins, polycarbonate resins or epoxy resins are also included.

Phosphazene compound Examples of the phosphazene compound represented by the general formulas (2) and (3) include phenoxyphosphazene and (poly) tolyloxyphosphazene (for example, o-tolyloxyphosphazene, m-tolyloxyphosphazene, p- Cyclic, such as tolyloxyphosphazene, o, m-tolyloxyphosphazene, o, p-tolyloxyphosphazene, m, p-tolyloxyphosphazene, o, m, p-tolyloxyphosphazene), (poly) xylyloxyphosphazene and / or or linear _{C 1-6} alkyl _{C 6-20} aryloxy phosphazene, (poly) phenoxy tolyloxy phosphazene (e.g., phenoxy o- tolyloxy phosphazene, a phenoxy m- tolyloxyethyl phosphazene, a phenoxy p- Toriruokishiho Phazen, phenoxy o, m-tolyloxyphosphazene, phenoxy o, p-tolyloxyphosphazene, phenoxy m, p-tolyloxyphosphazene, phenoxy o, m, p-tolyloxyphosphazene, etc.), (poly) phenoxyxyloxyphosphazene And cyclic and / or chain C _6-20 aryl C _1-10 alkyl C _6-20 aryloxy phosphazene such as (poly) phenoxytolyloxyxyloxyphosphazene.
Of these, cyclic and / or chain phenoxyphosphazene, cyclic and / or chain C _1-3 alkyl C _6-20 aryloxyphosphazene, C _6-20 aryloxy C _1-3 alkyl C _6-20 Aryloxyphosphazenes (eg, cyclic and / or chain tolyloxyphosphazenes, cyclic and / or chain phenoxytolylphenoxyphosphazenes, etc.).

In the cyclic phosphazene compound represented by the general formula (2), R ⁵ and R ⁶ may be the same or different and each represents an aryl group or an alkylaryl group. Examples of such an aryl group or alkylaryl group include a phenyl group, a naphthyl group, a methylphenyl group, and a benzyl group. Among them, cyclic phenoxyphosphazene in which R ⁵ and R ⁶ are phenyl groups is particularly preferable.
Examples of such a cyclic phenoxyphosphazene compound include hexachlorocyclotriphosphazene, octachlorocyclohexane, and a mixture of cyclic and linear chlorophosphazene obtained by reacting ammonium chloride and phosphorus pentachloride at a temperature of 120 to 130 ° C. Examples include compounds such as phenoxycyclotriphosphazene, octaphenoxycyclotetraphosphazene, and decaffenoxycyclopentaphosphazene obtained by removing a cyclic chlorophosphazene such as cyclotetraphosphazene and decachlorocyclopentaphosphazene and then substituting with a phenoxy group. .

  Moreover, in formula (2), t represents an integer of 3 to 25. Among them, a compound in which t is an integer of 3 to 8 is preferable, and a mixture of compounds having different t may be used. Among them, a mixture of compounds in which t = 3 is 50% by mass or more, t = 4 is 10 to 40% by mass, and t = 5 or more is 30% by mass or less is preferable.

In formula (3), R ⁷ and R ⁸ may be the same or different and each represents an aryl group or an alkylaryl group. Examples of such an aryl group or alkylaryl group include a phenyl group, a naphthyl group, a methylphenyl group, a benzyl group, and the like, and a chain phenoxyphosphazene in which R ⁷ and R ⁸ are phenyl groups is particularly preferable.
Such a chain phenoxyphosphazene compound is obtained by, for example, subjecting hexachlorocyclotriphosphazene obtained by the above-described method to reverse polymerization at a temperature of 220 to 250 ° C., and the obtained linear dichloromethane having a polymerization degree of 3 to 10,000. Examples thereof include compounds obtained by substituting phosphazene with a phenoxy group.

Also, R ⁹ is represented by -N = P (OR ⁷ ) ₃ groups, -N = P (OR ⁸ ) ₃ groups, -N = P (O) OR ⁷ groups, and -N = P (O) OR ⁸ groups. At least one selected is shown, and R ¹⁰ is -P (OR ⁷ ) ₄ group, -P (OR ⁸ ) ₄ group, -P (O) (OR ⁷ ) ₂ group, -P (O) (OR ⁸ ) At least one selected from _two groups.

  Moreover, in Formula (3), u shows the integer of 3-10,000, Preferably it is 3-1,000, More preferably, it is 3-100, More preferably, it is 3-25.

Further, the phosphazene compound may be a crosslinked phosphazene compound partially crosslinked. By having such a crosslinked structure, the heat resistance tends to be improved.
Examples of such crosslinked phosphazene compounds include compounds having a crosslinking structure represented by the following general formula (4), for example, 4,4′-sulfonyldiphenylene (bisphenol S residue), 2,2- (4 , 4′-diphenylene) isopropylidene group-crosslinked structure, 4,4′-oxydiphenylene group-crosslinked structure, 4,4′-thiodiphenylene group-crosslinked structure, etc. Examples thereof include compounds having a crosslinked structure of 4,4′-diphenylene group.

［式（４）中、Ｘ^２は−Ｃ（ＣＨ_３）_２−、−ＳＯ_２−、−Ｓ−、又は−Ｏ−であり、ｖは０又は１である。］

[In Formula (4), X ² is —C (CH ₃ ) ₂ —, —SO ₂ —, —S—, or —O—, and v is 0 or 1. ]

In addition, as the crosslinked phosphazene compound, a crosslinked phenoxyphosphazene compound obtained by crosslinking a cyclic phenoxyphosphazene compound in which R ⁵ and R ⁶ are phenyl groups in the general formula (2) with a crosslinking group represented by the general formula (4). Alternatively, a crosslinked phenoxyphosphazene compound obtained by crosslinking a chain phenoxyphosphazene compound in which R ⁷ and R ⁸ are phenyl groups in the general formula (3) with a crosslinking group represented by the general formula (4) is flame retardant. From the above point, a crosslinked phenoxyphosphazene compound obtained by crosslinking a cyclic phenoxyphosphazene compound with a crosslinking group represented by the general formula (4) is more preferable.

  The content of the phenylene group in the crosslinked phenoxyphosphazene compound is such that the cyclic phosphazene compound represented by the general formula (2) and / or the all phenyl groups in the chain phenoxyphosphazene compound represented by the general formula (3) and Based on the number of phenylene groups, it is usually 50 to 99.9%, preferably 70 to 90%. The crosslinked phenoxyphosphazene compound is particularly preferably a compound having no free hydroxyl group in the molecule.

  In the present invention, the phosphazene compound is a crosslinked phenoxy obtained by crosslinking the cyclic phenoxyphosphazene compound represented by the general formula (2) and the cyclic phenoxyphosphazene compound represented by the general formula (3) with a crosslinking group. In view of flame retardancy and mechanical properties, at least one selected from the group consisting of phosphazene compounds is preferable.

  The content of the phosphorus-based flame retardant (D) is preferably 3 to 30 parts by mass, more preferably 5 parts by mass or more, with respect to 100 parts by mass in total of the polycarbonate resin (A) and the styrene resin (B). More preferably, it is 8 mass parts or more, More preferably, it is 25 parts weight or less, More preferably, it is 20 mass parts or less. When the blending amount of the phosphorus-based flame retardant (D) is less than 3 parts by mass, the flame retardancy tends to be insufficient, and when it exceeds 30 parts by mass, a significant decrease in heat resistance and mechanical properties are likely to occur.

[Graft Copolymer (E)]
The thermoplastic resin composition for supercritical foam molding of the present invention preferably contains an elastomer of a graft copolymer system. Examples of the graft copolymer include an aromatic vinyl monomer and a rubbery polymer (e1). A graft copolymer (E) obtained by graft polymerization of at least one selected from (e2), a vinyl cyanide monomer (e3) and a methacrylic acid ester monomer (e4) is preferable. By containing such a graft copolymer (E), there is an effect in improving the impact resistance of a molded product particularly when supercritical foam molding is performed.

  Specific examples of the rubbery polymer (e1) constituting the graft copolymer (E) include polybutadiene rubber, polyisoprene rubber, butadiene-acrylic composite rubber, and styrene-butadiene rubber. These may be used alone or in admixture of two or more. Among these, diene rubbers, particularly polybutadiene rubber and styrene-butadiene rubber are preferable from the viewpoint of mechanical properties and surface appearance.

  The rubber polymer (e1) is graft-polymerized with at least one selected from an aromatic vinyl monomer (e2), a vinyl cyanide monomer (e3), and a methacrylic acid ester monomer (e4). .

The aromatic vinyl monomer (e2) to be graft-polymerized is not particularly limited as long as it is a compound having at least one vinyl bond and at least one aromatic ring, but has a substituent such as a functional group. None is preferred. Examples of the aromatic vinyl monomer (e2) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, β-methylstyrene, ethylstyrene, p-tert-butylstyrene, vinyltoluene, vinyl Examples include xylene and vinyl naphthalene. Of these, styrene and α-methylstyrene are preferred, and styrene is particularly preferred.
The aromatic vinyl monomer (e2) can be used alone or in combination of two or more, and a (meth) acrylic acid ester compound can also be used in combination.

  Examples of the vinyl cyanide monomer (e3) to be graft polymerized include acrylonitrile and methacrylonitrile. The vinyl cyanide monomer (e3) can be used not only alone but also in combination of two or more.

Preferred examples of the methacrylic acid ester monomer (e4) to be graft-polymerized include methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, and phenyl methacrylate. Can do.
A methacrylic acid ester monomer (e4) may be used individually by 1 type, or may mix and use 2 or more types.

  Further, other graft copolymerizable monomers other than the aromatic vinyl monomer (e2), the vinyl cyanide monomer (e3) and the methacrylic acid ester monomer (e4) can be used in combination. Specific examples of such monomers include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, and phenyl acrylate. And acrylate esters such as benzyl acrylate, epoxy group-containing (meth) acrylate compounds such as glycidyl (meth) acrylate; males such as maleimide, N-methylmaleimide and N-phenylmaleimide De compounds; maleic acid, phthalic acid, alpha, such as itaconic acid, beta-unsaturated carboxylic acid compounds and their anhydrides (e.g., maleic acid, etc.). These monomers may be used individually by 1 type, or may use 2 or more types together.

The graft copolymer (E) is preferably of the core / shell type graft copolymer type from the viewpoint of impact resistance and surface appearance. In particular, a core / shell type graft copolymer comprising a shell layer formed by graft copolymerization of an aromatic vinyl monomer and a methacrylic acid ester monomer around a diene rubber as a core layer is provided. Particularly preferred.
In such a core / shell type graft copolymer, the rubber component is preferably contained in an amount of 40% by mass or more, more preferably 60% by mass or more. Moreover, what contains 10 mass% or more of an aromatic vinyl monomer component and a methacrylic acid ester monomer component is preferable.

  Preferable specific examples of these core / shell type graft copolymers include methyl methacrylate-butadiene-styrene copolymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), and methyl methacrylate-butadiene copolymer. Examples thereof include a combination (MB), a methyl methacrylate-acrylic / butadiene rubber copolymer, and a methyl methacrylate-acrylic / butadiene rubber-styrene copolymer. Such rubbery polymers may be used alone or in combination of two or more.

A rubber polymer (e1) is graft-polymerized with at least one selected from an aromatic vinyl monomer (e2), a vinyl cyanide monomer (e3) and a methacrylic acid ester monomer (e4). As a manufacturing method of a graft copolymer (E), any manufacturing methods, such as block polymerization, solution polymerization, suspension polymerization, and emulsion polymerization, may be sufficient.
The copolymerization method may be single-stage or multistage grafting, but multistage graft copolymerization is preferred.

  By containing an ester compound (C) and a phosphorus flame retardant (D) and a graft copolymer (E) in the polycarbonate resin (A) and the styrene resin (B), flame retardancy and impact resistance are achieved. In addition, a polycarbonate / styrene resin alloy for supercritical foam molding having excellent appearance and excellent fluidity and foamability at the time of supercritical foam molding is possible.

  The content of the graft copolymer (E) is preferably 0.5 to 20 parts by mass with respect to a total of 100 parts by mass of the polycarbonate resin (A) and the styrene resin (B). When the content is less than 0.5 parts by mass, the impact resistance improving effect tends to be insufficient, and when the content exceeds 20 parts by mass, the appearance defect, heat resistance, difficulty of the molded product obtained by supercritical foam molding of the resin composition are difficult. Flammability is likely to decrease. The content is more preferably 1.5 parts by mass or more, more preferably 2 parts by mass or more, more preferably 100 parts by mass in total of the polycarbonate resin (A) and the styrene resin (B). 15 parts by mass or less, more preferably 10 parts by mass or less.

[Fluoropolymer (F)]
The thermoplastic resin composition of the present invention preferably contains a fluoropolymer (F).
Examples of the fluoropolymer (F) include a fluoroolefin resin. The fluoroolefin resin is usually a polymer or copolymer containing a fluoroethylene structure. Specific examples include difluoroethylene resin, tetrafluoroethylene resin, tetrafluoroethylene / hexafluoropropylene copolymer resin, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin, and the like. Of these, tetrafluoroethylene resin and the like are preferable. Examples of the fluoroethylene resin include a fluoroethylene resin having a fibril forming ability.

  Examples of the fluoroethylene resin having a fibril forming ability include “Teflon (registered trademark) 6J”, “Teflon (registered trademark) 640J” manufactured by Mitsui DuPont Fluorochemical Co., Ltd., “Polyflon F201L”, “Polyflon F103 manufactured by Daikin Industries, Ltd. ”,“ Polyflon FA500B ”,“ Polyflon FA500H ”and the like. Further, examples of commercially available aqueous dispersions of fluoroethylene resin include “Teflon (registered trademark) 31-JR” manufactured by Mitsui DuPont Fluorochemical Co., Ltd. and “Fullon D-210C” manufactured by Daikin Industries, Ltd. Furthermore, a fluoroethylene polymer having a multilayer structure obtained by polymerizing vinyl monomers can also be used. Examples of such a fluoroethylene polymer include polystyrene-fluoroethylene composites, polystyrene-acrylonitrile-fluoroethylene. Examples include composites, polymethyl methacrylate-fluoroethylene composites, polybutyl methacrylate-fluoroethylene composites, etc. Specific examples include “Metablene A-3800” manufactured by Mitsubishi Rayon Co., Ltd., “Blendex” manufactured by GE Specialty Chemical Co., Ltd. 449 "and the like. In addition, 1 type may contain the dripping inhibitor and 2 or more types may contain it by arbitrary combinations and a ratio.

  The content of the fluoropolymer (F) is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, with respect to 100 parts by mass in total of the polycarbonate resin (A) and the styrene resin (B). More preferably 0.05 parts by mass or more, particularly preferably 0.1 parts by mass or more, and preferably 2 parts by mass or less, preferably 1 part by mass or less, more preferably 0.7 parts by mass or less. It is. When the content of the fluoropolymer (F) is less than 0.01 parts by mass, the flame retardancy effect due to the anti-dripping agent tends to be insufficient, and when the content exceeds 2 parts by mass, the thermoplastic resin composition Deterioration of the appearance and mechanical strength of the molded product obtained by molding is likely to occur.

[Silicate compound (G)]
It is also preferable to mix | blend a silicate compound (G) with the thermoplastic resin composition of this invention. The silicate compound (G) has a large effect of preventing dripping of the molten resin at the time of combustion, can further improve the flame retardancy of the resin composition, and can improve rigidity and dimensional stability.
Specific examples of the silicate compound (G) include talc, kaolin, clay, mica, montmorillonite, wollastonite, natural silica, synthetic silica, various glass fillers, zeolite and diatomaceous earth, or a mixture thereof. However, talc, mica and wollastonite are preferred, and talc is most preferred from the balance of flame retardancy and dimensional stability. Among the above, talc is particularly effective in preventing molten resin drip during combustion.

  The particle size of talc is not particularly limited, but is preferably 1.0 to 20 μm, more preferably 1.5 to 18 μm, as a number average particle size measured by a sedimentation method (Asada method) using a light transmission type particle size distribution analyzer. It is. When the number average particle size is 1.0 μm or more, flame retardancy tends to be improved, and when it is 20 μm or less, the appearance of the molded product tends to be further improved.

The silicate compound (G) is prepared by using various coupling agents for the purpose of increasing the affinity or interfacial bond strength with the polycarbonate resin (A), the styrene resin (B), and the graft copolymer (E). It can also be used.
As the coupling agent, silane-based, chromium-based and titanium-based coupling agents are usually used. Among them, those containing silane coupling agents such as epoxy silane compounds such as γ-glycidoxypropyltrimethoxysilane, vinyltrichlorosilane compounds and γ-aminopropyltriethoxysilane compounds are preferable. At this time, in order to improve mechanical strength and kneadability, treatment with various surfactants such as nonionic, cationic, and anionic types and dispersants such as fatty acids, metal soaps, and various resins may be performed. preferable.

  The preferable content of the silicate compound (G) is 0 to 5 parts by mass, and 0.5 to 4 parts by mass with respect to 100 parts by mass in total of the polycarbonate resin (A) and the styrene resin (B). More preferred.

[Stabilizer (H)]
The thermoplastic resin composition of the present invention preferably contains a stabilizer, and the stabilizer is preferably a phosphorus stabilizer or a phenol stabilizer.

  Any known phosphorous stabilizer can be used. Specific examples include phosphorus oxo acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; acidic pyrophosphate metal salts such as acidic sodium pyrophosphate, acidic potassium pyrophosphate, and acidic calcium pyrophosphate; phosphoric acid Group 1 or Group 2B metal phosphates such as potassium, sodium phosphate, cesium phosphate and zinc phosphate; organic phosphate compounds, organic phosphite compounds, organic phosphonite compounds, etc. Particularly preferred.

Organic phosphite compounds include triphenyl phosphite, tris (monononylphenyl) phosphite, tris (monononyl / dinonyl phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, monooctyl Diphenyl phosphite, dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, 2,2-methylenebis (4,6-di- tert-butylphenyl) octyl phosphite and the like.
Specific examples of such organic phosphite compounds include, for example, “ADEKA STAB 1178”, “ADEKA STAB 2112”, “ADEKA STAB HP-10” manufactured by ADEKA, “JP-351” manufactured by Johoku Chemical Industry Co., Ltd., “ JP-360 ”,“ JP-3CP ”,“ Irgaphos 168 ”manufactured by BASF, and the like.
In addition, 1 type may contain phosphorus stabilizer and 2 or more types may contain it by arbitrary combinations and a ratio.

  The content of the phosphorus stabilizer is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, more preferably 100 parts by mass in total of the polycarbonate resin (A) and the styrene resin (B). It is 0.03 mass part or more, and is 1 mass part or less normally, Preferably it is 0.7 mass part or less, More preferably, it is 0.5 mass part or less. If the content of the phosphorus stabilizer is less than the lower limit of the range, the thermal stability effect may be insufficient, and if the content of the phosphorus stabilizer exceeds the upper limit of the range, the effect May stop and become economical.

  As a phenol type stabilizer, a hindered phenol type antioxidant is mentioned, for example. Specific examples thereof include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl). ) Propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexane-1,6-diylbis [3- (3,5-di-) tert-butyl-4-hydroxyphenyl) propionamide], 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] ] Methyl] phosphoate, 3,3 ', 3 ", 5,5', 5" -hexa-tert-butyl-a, a ', a -(Mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl- 4-hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-) tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6- Bis (octylthio) -1,3,5-triazin-2-ylamino) phenol, 2- [1- (2-hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6 Di -tert- pentylphenyl acrylate.

Among them, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate preferable. Specific examples of such a phenolic antioxidant include “Irganox 1010”, “Irganox 1076” manufactured by BASF, “Adekastab AO-50”, “Adekastab AO-60” manufactured by ADEKA, and the like. Is mentioned.
In addition, 1 type may contain the phenol type stabilizer, and 2 or more types may contain it by arbitrary combinations and a ratio.

  The content of the phenol stabilizer is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, with respect to 100 parts by mass in total of the polycarbonate resin (A) and the styrene resin (B). The amount is usually 1 part by mass or less, preferably 0.5 part by mass or less. When the content of the phenol-based stabilizer is less than the lower limit of the range, the effect as the phenol-based stabilizer may be insufficient, and the content of the phenol-based stabilizer exceeds the upper limit of the range. If this is the case, the effect may reach its peak and not economical.

[Other ingredients]
The thermoplastic resin composition for supercritical foam molding of the present invention may contain other components as necessary, in addition to those described above, as long as the desired physical properties are not significantly impaired. Examples of other components include resins other than those described above and various resin additives. In addition, 1 type may contain other components and 2 or more types may contain them by arbitrary combinations and ratios.

Other resins Examples of the other resins include thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate, polybutylene terephthalate resin; polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resins; polyimide resins; Examples include imide resins; polyurethane resins; polyphenylene ether resins; polyphenylene sulfide resins;
In addition, 1 type may contain other resin and 2 or more types may contain it by arbitrary combinations and ratios.

-Resin additive Examples of the resin additive include an ultraviolet absorber, a dye / pigment, an antistatic agent, an antifogging agent, an antiblocking agent, a fluidity improver, a plasticizer, a dispersant, and an antibacterial agent. In addition, 1 type may contain resin additive and 2 or more types may contain it by arbitrary combinations and a ratio.

[Method for producing thermoplastic resin composition]
There is no restriction | limiting in the manufacturing method which manufactures the thermoplastic resin composition of this invention, The manufacturing method of a well-known thermoplastic resin composition can be employ | adopted widely.
Specific examples include polycarbonate resin (A), styrenic resin (B), ester compound (C), and other components to be blended as necessary, such as various mixers such as tumblers and Henschel mixers. Examples thereof include a method of using a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, a kneader, and the like, followed by melt-kneading after mixing in advance.

In addition, for example, the thermoplastic resin composition of the present invention is manufactured without mixing each component in advance or by mixing only a part of the components in advance and supplying the mixture to an extruder using a feeder and melt-kneading. You can also
Also, for example, by mixing a part of the components in advance and supplying the resulting mixture to an extruder and melt-kneading it as a master batch, this master batch is again mixed with the remaining components and melt-kneaded. The thermoplastic resin composition of the present invention can also be produced.
In addition, for example, when mixing a component that is difficult to disperse, the component that is difficult to disperse is dissolved or dispersed in a solvent such as water or an organic solvent in advance, and kneaded with the solution or the dispersion. It can also improve sex.

[Supercritical foam molding]
The thermoplastic resin composition of the present invention is made into a foam molded article by supercritical foam molding. As the molding machine, an injection molding machine, an extrusion molding machine, a blow molding machine or the like is used, and an injection molding machine is preferably used.
Various known methods can be applied to the supercritical foam molding. One specific example will be explained. First, the obtained pellets of the thermoplastic resin composition are put into a molding machine from a hopper of an injection molding machine and heated and melted in a conveying zone and a compression zone of a molding machine screw. And then sent to the metering zone and compression zone of the molding machine screw. Then, nitrogen or carbon dioxide gas as a supercritical fluid is injected from the injection port provided in the measuring zone, and the supercritical fluid and the molten resin are pressurized and single-phased, from the nozzle of the injection molding machine. It is injected, flows while maintaining a single phase in the sprue and runner, sent to the mold cavity, and after passing through the gate, bubble nuclei are generated, filling the mold progresses while the bubbles expand Thus, supercritical foam molding is performed. Here, the generation of bubble nuclei is performed by reducing the pressure in the mold to a pressure equal to or lower than the critical pressure of nitrogen or carbon dioxide, so that nitrogen or carbon dioxide is supersaturated, and the molten resin composition becomes supersaturated. This is done by generating a large number of cell nuclei.

[Molded body]
The thermoplastic resin composition of the present invention is molded into an arbitrary shape by supercritical foam molding and used as a molded product. There are no restrictions on the shape, pattern, color, size, etc. of the molded product, and it may be set arbitrarily according to the application of the molded product.

  Examples of the molded article include parts such as electric / electronic equipment, OA equipment, information terminal equipment, machine parts, home appliances, vehicle parts, building members, various containers, and lighting equipment. Among these, it is particularly suitable for various parts of electric / electronic devices and OA devices.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified and implemented without departing from the gist of the present invention. In the following description, “parts” means “parts by mass” based on mass standards unless otherwise specified.

  Each component used in the following Examples and Comparative Examples is as shown in Table 1 below.

(Examples 1-10, Comparative Examples 1-6)
[Manufacture of resin pellets]
Among the components described in Table 1 above, components other than the D1 component were blended in the proportions (mass ratio) described in Table 2 below, mixed for 20 minutes with a tumbler, and then manufactured by Nippon Steel Works, Ltd., equipped with 1 vent. Supply to the twin screw extruder (TEX30α) from the upstream feeder, and further knead in the form of a strand while supplying the D1 component from the middle of the barrel under the conditions of a rotational speed of 250 rpm, a discharge rate of 45 kg / hour, and a barrel temperature of 260 ° C. The extruded molten resin was quenched in a water bath and pelletized using a pelletizer to obtain resin composition pellets.

[Evaluation of mold corrosion]
The mold corrosivity was evaluated as follows.
For normal molding, the pellets of the obtained resin composition were preliminarily dried at 80 ° C. for 6 to 12 hours in advance, using a J85AD injection molding machine manufactured by Nippon Steel, Ltd., cylinder temperature 250 ° C., mold temperature 50 ° C. Normal injection molding was performed at a setting of 30 seconds per cycle.
On the other hand, with regard to supercritical foam molding, nitrogen made into a supercritical state using a MuCell SCF device (model: SII-TRJ-10-A) manufactured by TREXEL is transferred to a cylinder of a J85AD injection molding machine manufactured by Nippon Steel Works. The supercritical foam molding was carried out in a series of cycles in which a predetermined amount was injected, mixed with the molten resin composition, and injected into the mold. The preliminary drying and molding conditions of the resin composition pellets were the same as those for normal molding, and the supercritical nitrogen injection amount was set to 0.2% by mass of the normal molding quality.

The mold corrosivity was evaluated using a mold having the structure shown in FIG. 1A is a sectional plan view, and FIG. 1B is a sectional side view. 1 is a sprue, 2 is a runner, 3 is a cavity (20 mm × 60 mm × 3 mm to 1 mm thickness), 4 is a protruding pin, and 5 shown by a broken line is a slot portion.
After forming 200 shots, the insert of the mold was removed, and evaluation was performed by visually confirming the rust state of the insert after being left for 1 hour under conditions of a temperature of 65 ° C. and a humidity of 85%.
The criteria for visual evaluation of the cavity portion are as follows.
A: Rust corrosion cannot be visually confirmed B: Discoloration due to rust corrosion is less than 10% of the cavity surface area C: Discoloration due to rust corrosion is 10% to 30% of the cavity surface area D: Discoloration due to rust corrosion More than 30% to less than 60% of cavity surface area E: Discoloration due to rust corrosion is more than 60% of cavity surface area

The evaluation results are shown in Table 2 below.
In the following examples, other mechanical properties or the like were not particularly deteriorated.

  Since the thermoplastic resin composition for supercritical foam molding of the present invention has no problem of corrosion of the mold cavity surface during supercritical foam molding, it can produce good molded products with high productivity in various supercritical foam molding. , Its industrial applicability is high.

Claims (8)

  A saturated aliphatic carboxylic acid having 10 to 22 carbon atoms and a monovalent aliphatic alcohol with respect to a total of 100 parts by mass of 90 to 20 parts by mass of the polycarbonate resin (A) and 10 to 80 parts by mass of the styrene resin (B) A thermoplastic resin composition for supercritical foam molding, comprising 0.01 to 2 parts by mass of the ester compound (C).   The thermoplastic resin composition for supercritical foam molding according to claim 1, wherein the styrenic resin (B) is an ABS resin and / or an AS resin.   The thermoplastic resin composition for supercritical foam molding according to claim 1 or 2, wherein the ester compound (C) is stearyl stearate and / or behenyl behenate.   Furthermore, 3-30 mass parts of phosphorous flame retardant (D) is contained in any one of Claims 1-3 which contains 3-30 mass parts with respect to a total of 100 mass parts of polycarbonate resin (A) and a styrene resin (B). The thermoplastic resin composition for supercritical foam molding described.   The thermoplastic resin composition for supercritical foam molding according to claim 4, wherein the phosphorus flame retardant (D) is a condensed phosphate ester and / or a phosphazene compound.   Further, at least one selected from the aromatic vinyl monomer (e2), the vinyl cyanide monomer (e3) and the methacrylic acid ester monomer (e4) is graft-polymerized on the rubber polymer (e1). The graft copolymer (E) obtained is contained in an amount of 0.5 to 20 parts by mass with respect to a total of 100 parts by mass of the polycarbonate resin (A) and the styrene resin (B). The thermoplastic resin composition for supercritical foam molding described in the item.   The gas used for supercritical foaming is nitrogen, The thermoplastic resin composition for supercritical foam molding of any one of Claims 1-6 characterized by the above-mentioned.   A molded article formed by supercritical foam molding using the thermoplastic resin composition for supercritical foam molding according to any one of claims 1 to 7.

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