WO2015079755A1

WO2015079755A1 - Polylactic acid resin composition

Info

Publication number: WO2015079755A1
Application number: PCT/JP2014/072141
Authority: WO
Inventors: 貴宏大島
Original assignee: 花王株式会社
Priority date: 2013-11-29
Filing date: 2014-08-25
Publication date: 2015-06-04
Also published as: JP2015127388A

Abstract

Provided is a polylactic acid resin composition comprising a polylactic acid resin, a triaryl phosphate, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, wherein the triaryl phosphate includes one or more of an alkyl aryl group having an alkyl group having 1 to 3 carbon atoms, the total mass of the triaryl phosphate and the plasticizer is 16 to 30 parts by mass with respect to 100 parts by mass of the polylactic acid resin, the content of the surface-treated metal hydroxide with respect to 100 parts by mass of the polylactic acid resin is 10 to 100 parts by mass, and the content of the melamine compound with respect to 100 parts by mass of the polylactic acid resin is 10 to 100 parts by mass. This polylactic acid resin composition can be suitably used as household appliance parts such as cabinets of information appliances.

Description

Polylactic acid resin composition

The present invention relates to a polylactic acid resin composition. More specifically, the present invention relates to a polylactic acid resin composition that can be suitably used as a home appliance part such as a casing of an information home appliance, and a molded body obtained by injection molding the composition.

Polylactic acid resin is inexpensive because L-lactic acid as a raw material is produced by fermentation using sugars extracted from corn, straw, etc., and the carbon dioxide emission is extremely low because the raw material is derived from plants. In addition, due to the characteristics of the resin such as high rigidity and high transparency, its use is currently expected.

Patent Document 1 discloses a polylactic acid resin, a metal hydroxide, a phosphorus compound, and a volatilization other than the phosphorus compound in order to provide a polylactic acid resin composition having an excellent balance between flame retardancy and bleeding properties. A polylactic acid resin composition is disclosed in which the content of the phosphorus compound is 10 parts by mass or less with respect to a total value of 100 parts by mass of the polylactic acid resin.

Patent Document 2 discloses that in order to provide a flame-retardant and impact-resistant polylactic acid resin composition having excellent heat resistance, the main component is a polylactic acid resin and 3 to 30% by mass of triphenyl phosphates. A polylactic acid resin composition characterized by melting and kneading a mixture containing 0.01 to 5% by mass of a (meth) acrylic acid ester compound and 0.001% by mass or more of a peroxide is disclosed. .

Patent Document 3 discloses a polylactic acid resin and a metal hydrate surface-treated with an isocyanate-based silane coupling agent in order to obtain a polylactic acid resin composition excellent in heat resistance, impact resistance, and flexibility. And a polylactic acid resin composition in which the content of the alkali metal substance in the metal hydrate is 0.2% by mass or less is disclosed.

International Publication No. 2011/155119 JP 2008-101084 A JP 2009-270087 A

Summary of invention

The present invention relates to the following [1] to [2].
[1] A polylactic acid resin composition comprising a polylactic acid resin, a triaryl phosphate, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, wherein the triaryl phosphate has 1 to 3 carbon atoms. The surface-treated metal comprising at least one alkylaryl group having the above alkyl group, wherein the total mass of the triaryl phosphate and the plasticizer is 16 to 30 parts by mass with respect to 100 parts by mass of the polylactic acid resin. The hydroxide content is 10 to 100 parts by mass with respect to 100 parts by mass of the polylactic acid resin, and the melamine compound content is 10 to 100 parts by mass with respect to 100 parts by mass of the polylactic acid resin. Polylactic acid resin composition.
[2] A molded article obtained by melt-kneading the composition according to [1] and then injection molding.

Detailed Description of the Invention

Although Patent Document 1 describes that the bleeding of a phosphorus compound can be suppressed, there is a problem that the compounding amount of the phosphorus compound is limited and the impact resistance is not sufficient. Moreover, in the polylactic acid resin composition of patent document 2, there exists a subject that phosphoric acid triphenyl bleeds from the molded object obtained. In patent document 3, there exists a subject that a flame retardance is not enough.

The present invention relates to a polylactic acid resin composition excellent in fluidity, flame retardancy, impact resistance, durability and bleed suppression, and a molded article obtained from the composition.

The polylactic acid resin composition of the present invention can provide a molded article excellent in fluidity, excellent in flame retardancy, impact resistance (impact strength), durability and bleed suppression.

The polylactic acid resin composition of the present invention contains a polylactic acid resin, a triaryl phosphate, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, and the triaryl phosphate has 1 to 1 carbon atoms. 3 containing at least one alkylaryl group having 3 alkyl groups, and the triaryl phosphate and the plasticizer are blended in a specific amount, and the surface-treated metal hydroxide and the melamine compound are respectively specified in a specific amount. By containing, there exists an effect of being excellent in fluidity | liquidity, a flame retardance, impact resistance, durability, and bleed suppression. Hereinafter, the surface-treated metal hydroxide may be simply referred to as surface-treated metal hydroxide.

The reason why such an excellent effect is exhibited is that, for example, a triaryl phosphate containing one or more alkylaryl groups having an alkyl group having 1 to 3 carbon atoms is liquid at room temperature, Increases fluidity. Moreover, since fluidity | liquidity improves, when it mixes with a polylactic acid resin although it does not reach a general plasticizer, it has a function which improves the crystallinity of this resin, and it is estimated that impact resistance improves. In addition, in the case of solid triaryl phosphate, impact resistance is lowered, and in the case of condensed aryl phosphate, in addition to impact resistance, bleed resistance is also lowered. Therefore, triaryl phosphate having the above structure and a plasticizer are combined in total. By using the specific amount in combination, the polylactic acid resin composition has high crystallinity, impact resistance and durability, and bleed resistance of both components can be improved. Furthermore, since the blending amount of the surface-treated metal hydroxide or melamine compound can be reduced due to the flame retardancy of the triaryl phosphate itself, the triaryl phosphate, plasticizer, metal hydroxide and melamine compound having the above structure are used in combination. Thus, it is possible to improve impact resistance, durability, and bleed resistance while enhancing flame retardancy.

[Polylactic acid resin composition]
Hereinafter, each component will be described.

[Polylactic acid resin]
Examples of the polylactic acid resin include commercially available polylactic acid resins (for example, manufactured by Nature Works, trade names: Nature Works PLA / NW3001D, NW4032D, etc.), and polylactic acid resins synthesized from lactic acid and lactide according to a known method. Can be mentioned. From the viewpoint of improvement in strength and heat resistance, a polylactic acid resin having an optical purity of preferably 90% or more, more preferably 95% or more is preferable. For example, a polylactic acid resin having a relatively high molecular weight and a high optical purity is manufactured by Nature Works. Lactic acid resin (NW4032D etc.) is preferable. The optical purity is a ratio of mol% occupied by L-form or D-form in polylactic acid resin.

In addition, in the present invention, in addition to the polylactic acid resin, other biodegradable resins may be appropriately blended within a range that does not impair the effects of the present invention. Examples of other biodegradable resins include polyester resins such as polybutylene succinate, polyhydroxyalkanoic acid, and the like. Further, a part or all of the polylactic acid resin may be blended as a polymer alloy by blending the other biodegradable resin or non-biodegradable resin such as polypropylene and polylactic acid resin. In the present specification, “biodegradable” means a property that can be decomposed into low molecular weight compounds by microorganisms in nature, and specifically, JIS K6953 (ISO 14855) “controlled aerobic composting conditions. This means biodegradability based on the “Aerobic and Ultimate Biodegradation and Disintegration Test”.

The content of the polylactic acid resin in the polylactic acid resin composition is preferably 30% by mass or more, more preferably 40% by mass, from the viewpoint of improving fluidity, flame retardancy, impact resistance, bleed resistance and durability. More preferably, the content is 43% by mass or more, and from the viewpoint of increasing durability, flame retardancy, and impact resistance by adding a plasticizer or a flame retardant, it is preferably 80% by mass or less, more preferably 70% by mass or less. More preferably, it is 60 mass% or less, More preferably, it is 55 mass% or less.

[Triaryl phosphate]
The triaryl phosphate used in the present invention may be any triaryl phosphate containing one or more alkylaryl groups having an alkyl group having 1 to 3 carbon atoms (hereinafter, also simply referred to as triaryl phosphate). The following general formula:
(R ⁷ R ⁸ ArO) _a (ArO) _3-a PO
(In the formula, Ar represents a benzene ring, and R ⁷ and R ⁸ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, except that both are hydrogen atoms; Represents an integer of ~ 3)
The compound represented by these is preferable.

As R ⁷ and R ⁸ in the above formula, from the viewpoint of impact resistance, fluidity, flame retardancy, bleed resistance, and durability, when all are methyl groups, R ⁷ is a methyl group, and R ⁸ is When it is a hydrogen atom, R ⁷ is an ethyl group, and when R ⁸ is a hydrogen atom, it is preferable that R ⁷ is an isopropyl group and R ⁸ is a hydrogen atom, R ⁷ is a methyl group, and R ⁸ is a hydrogen atom. In some cases, it is more preferable that R ⁷ is an isopropyl group and R ⁸ is a hydrogen atom.

In the above formula, a represents an integer of 1 to 3, but from the viewpoint of impact resistance, fluidity, flame retardancy, bleed resistance and durability, an integer of 1 to 2 is preferable, and 1 is more preferable. That is, the compound represented by the above formula is a compound containing one or more, preferably 1 to 2, more preferably 1 alkylaryl group having an alkyl group having 1 to 3 carbon atoms.

Specific examples of the triaryl phosphate represented by the above formula include trixylenyl phosphate, tricresyl phosphate, dixylenyl phenyl phosphate, dicresyl phenyl phosphate, xylenyl diphenyl phosphate, isopropyl phenyl diphenyl phosphate, and cresyl. The 1 type (s) or 2 or more types chosen from the group which consists of diphenyl phosphate can be mentioned. These can be used alone or in combination of two or more. Among them, it is preferable to use isopropylphenyl diphenyl phosphate and cresyl diphenyl phosphate alone or in combination.

The content of triaryl phosphate in the polylactic acid resin composition is preferably 5 parts by mass or more from the viewpoint of fluidity, flame retardancy, bleed resistance, and impact resistance with respect to 100 parts by mass of the polylactic acid resin. Preferably it is 6 parts by mass or more, more preferably 8 parts by mass or more, more preferably more than 10 parts by mass. From the viewpoint of bleed resistance, it is preferably 21 parts by mass or less, more preferably 18 parts by mass or less, Preferably it is 16 mass parts or less, More preferably, it is 14 mass parts or less.

[Plasticizer]
The polylactic acid resin composition of the present invention contains a plasticizer from the viewpoint of improving impact resistance and fluidity.

The plasticizer is preferably a polyester plasticizer, a polyhydric alcohol ester plasticizer, a polycarboxylic acid ester plasticizer, and a phosphate ester plasticizer from the viewpoint of fluidity, impact resistance and bleed resistance. The 1 type (s) or 2 or more types chosen from the group which consists of an agent can be mentioned. The phosphate ester plasticizer in this specification excludes triaryl phosphates containing one or more alkylaryl groups having an alkyl group having 1 to 3 carbon atoms.

Specific examples of the polyester plasticizer are preferably dicarboxylic acids having 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and preferably dialcohols having 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms. Or the polyester by the (poly) oxyalkylene adduct can be mentioned. Examples of the dicarboxylic acid include succinic acid, adipic acid, sebacic acid, terephthalic acid, and isophthalic acid. Examples of the dialcohol include propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6- Examples include hexanediol, ethylene glycol, diethylene glycol, and triethylene glycol. Moreover, the hydroxyl group and carboxy group of the polyester terminal may be esterified with monocarboxylic acid or monoalcohol and blocked.

Specific examples of the polyhydric alcohol ester plasticizer include a polyhydric alcohol or an (poly) oxyalkylene adduct thereof, preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 carbon atom. And mono-, di- or triesters with 1 to 4 monocarboxylic acids. The polyhydric alcohol is preferably a polyhydric alcohol having 3 to 200 carbon atoms, and examples thereof include polyethylene glycol, polypropylene glycol, glycerin, and the above dialcohol. Examples of the monocarboxylic acid include acetic acid and propionic acid.

As the polyvalent carboxylic acid ester plasticizer, polyvalent carboxylic acid and preferably 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 6 carbon atoms, still more preferably 1 carbon atom. And mono-, di- or triesters with 1 to 4 monoalcohols or their (poly) oxyalkylene adducts. The polyvalent carboxylic acid is preferably a polyvalent carboxylic acid having 3 to 10 carbon atoms, and examples thereof include trimellitic acid and the above dicarboxylic acid. Examples of the monoalcohol include methanol, ethanol, 1-propanol, and 1-butanol. Specifically, phthalic acid esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diheptyl phthalate, dibenzyl phthalate, and butyl benzyl phthalate; tributyl trimellitic acid, trioctyl trimellitic acid, tri Trimellitic acid esters such as trihexyl meritate; Adipic acid esters such as diisodecyl adipate and octyldecyl adipate; Citric acid esters such as triethyl acetyl citrate and tributyl acetyl citrate; Azelaic acid such as di-2-ethylhexyl azelate Esters; sebacic acid esters such as dibutyl sebacate and di-2-ethylhexyl sebacate; polyethylene glycol monomethyl ether having an average addition mole number of succinic acid and ethylene oxide of 2 to 3 Such esters of (one per ethylene oxide hydroxyl 2-3 moles added) can be exemplified.

Examples of the phosphoric ester plasticizer include mono-, di- or triesters of phosphoric acid and the above monoalcohol or its (poly) oxyalkylene adduct. Specific examples include tributyl phosphate, tri-2-ethylhexyl phosphate, trioctyl phosphate, tris (ethoxyethoxyethyl) phosphate, and the like.

From the viewpoint of impact resistance, fluidity and bleed resistance, ester compounds having a (poly) oxyalkylene group or an alkylene group having 2 to 6 (preferably 2 to 4) carbon atoms are preferred. A polyester plasticizer, a polyhydric alcohol ester plasticizer, a polycarboxylic acid ester plasticizer, and a phosphate ester plasticizer having a group or an alkylene group having 2 to 6 carbon atoms (preferably 2 to 4 carbon atoms) One type or two or more types selected from the group consisting of The (poly) oxyalkylene group means an oxyalkylene group or a polyoxyalkylene group. As the oxyalkylene group, an oxyethylene group, an oxypropylene group or an oxybutylene group is preferable, and an oxyethylene group or an oxypropylene group is more preferable.

Further, the plasticizer is preferably one or more selected from the group consisting of the following compound groups (A) to (C), and when used in combination of two or more, different compounds even in the same compound group It may be a group.
Compound group (A) An ester compound having two or more ester groups in the molecule, wherein at least one of the alcohol components constituting the ester compound is an average of 2 to 3 alkylene oxides per hydroxyl group. Ester compound group (B) which is an alcohol added with 5 to 5 moles Formula (I):
R ¹ O—CO—R ² —CO — [(OR ³ ) _m O—CO—R ² —CO—] _n OR ¹ (I)
(Wherein R ¹ is an alkyl group having 1 to 4 carbon atoms, R ² is an alkylene group having 2 to 4 carbon atoms, R ³ is an alkylene group having 2 to 6 carbon atoms, and m is 1 to 6) And n represents a number from 1 to 12, provided that all R ² may be the same or different, and all R ³ may be the same or different.
Compound group (C) represented by formula (II):

(Wherein R ⁴ , R ⁵ and R ⁶ each independently represents an alkyl group having 1 to 4 carbon atoms, and A ¹ , A ² and A ³ each independently represents an alkylene group having 2 or 3 carbon atoms) X, y and z are each independently a positive number indicating the average number of moles added of the oxyalkylene group, and x + y + z is a number exceeding 3 and satisfying 12 or less)
Compound represented by

Compound group (A)
As an ester compound contained in the compound group (A), from the viewpoint of impact resistance and bleed resistance, a polyhydric alcohol ester or a polycarboxylic acid ether ester having two or more ester groups in the molecule, An ester compound in which at least one alcohol component constituting the ester compound is an alcohol obtained by adding an average of 0.5 to 5 moles of alkylene oxide having 2 to 3 carbon atoms per hydroxyl group is preferable.

Specific compounds include esters of acetic acid and glycerin with an average of 3 to 6 moles of ethylene oxide adduct (addition of 1 to 2 moles of ethylene oxide per hydroxyl group), and the average number of moles of acetic acid and ethylene oxide added is 4 to 4 6 Esters with polyethylene glycol, Esters with polyethylene glycol monomethyl ether having an average addition mole number of succinic acid and ethylene oxide of 2 to 3 (addition of 2 to 3 mol of ethylene oxide per hydroxyl group), Adipic acid and diethylene glycol monomethyl Esters with ethers and esters with 1,3,6-hexanetricarboxylic acid and diethylene glycol monomethyl ether are preferred.

Compound group (B)
R ¹ in the formula (I) included in the compound group (B) represents an alkyl group having 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms, and two R ¹ exist in one molecule and are present at both ends of the molecule. Exists. R ¹ may be linear or branched as long as it has 1 to 4 carbon atoms. Specific examples include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, and iso-butyl group. Among them, the compatibility with polylactic acid resin is improved. From the viewpoint of improving fluidity, impact resistance and bleed resistance, a methyl group and an ethyl group are preferable, and a methyl group is more preferable.

R ² in the formula (I) represents an alkylene group having 2 to 4 carbon atoms, and a linear alkylene group is a preferred example. Specific examples include an ethylene group, a 1,3-propylene group, and a 1,4-butylene group. Among them, the compatibility with the polylactic acid resin is improved, and the fluidity, impact resistance and bleed resistance are improved. From the viewpoint of improving, ethylene group and 1,3-propylene group are preferable, ethylene group is more preferable, and from the viewpoint of bleed resistance and economy, ethylene group and 1,4-butylene group are preferable, and ethylene group is more preferable. . However, all R ² may be the same or different.

R ³ in formula (I) represents an alkylene group having 2 to 6 carbon atoms, and OR ³ is present in the repeating unit as an oxyalkylene group. R ³ may be linear or branched as long as it has 2 to 6 carbon atoms. The number of carbon atoms of the alkylene group is preferably 2 to 6 and more preferably 2 to 3 from the viewpoint of improving compatibility with the polylactic acid resin and improving fluidity, impact resistance and bleed resistance. Specifically, ethylene group, 1,2-propylene group, 1,3-propylene group, 1,2-butylene group, 1,3-butylene group, 1,4-butylene group, 2-methyl-1,3 -Propylene group, 1,2-pentylene group, 1,4-pentylene group, 1,5-pentylene group, 2,2-dimethyl-1,3-propylene group, 1,2-hexylene group, 1,5-hexylene Group, 1,6-hexylene group, 2,5-hexylene group, 3-methyl-1,5-pentylene group, among which ethylene group, 1,2-propylene group, 1,3-propylene group are preferable. However, all R ³ may be the same or different.

M represents the average number of repeating oxyalkylene groups and is a number of 1 to 6. When m increases, the ether group value of the ester compound represented by the formula (I) increases, which tends to be oxidized and the stability tends to decrease. From the viewpoint of improving the compatibility with the polylactic acid resin and improving fluidity, impact resistance and bleed resistance, the number is preferably 1 to 4, and more preferably 1 to 3.

N represents the average degree of polymerization and is a number from 1 to 12. From the viewpoint of improving compatibility with the polylactic acid resin and improving fluidity, impact resistance and bleed resistance, the number is preferably 1 to 6, more preferably 1 to 5, and more preferably 1 to 4. Further preferred.

Specific examples of the compound represented by formula (I) include: R ¹ is all methyl group, R ² is ethylene group or 1,4-butylene group, R ³ is ethylene group or 1,3-propylene group , M is a number from 1 to 4, and n is a number from 1 to 6, R ¹ is all methyl group, R ² is ethylene group or 1,4-butylene group, R ³ is ethylene group or 1, More preferred is a compound which is a 3-propylene group, wherein m is a number of 1 to 3, and n is a number of 1 to 5.

Among such structures, from the viewpoint of improving bleeding resistance, at least one dibasic acid selected from succinic acid, glutaric acid, and adipic acid, diethylene glycol, triethylene glycol, 1,2-propanediol, and 1 An oligoester of at least one dihydric alcohol selected from 1,3-propandiol [in formula (I), n = 1.2 to 3] is preferred.

The compound represented by the formula (I) may be a commercially available product or a compound synthesized according to a known production method. For example, the compound represented by the formula (I) is produced according to a method as disclosed in JP2012-62467A. be able to.

Further, the compound represented by the formula (I) is not particularly limited as long as it has the above-mentioned structure. However, compounds obtained by reacting the following raw materials (1) to (3) are preferable. In addition, (1) and (2) or (2) and (3) may form an ester compound. (2) may be an acid anhydride or an acid halide.
(1) Monohydric alcohol having an alkyl group having 1 to 4 carbon atoms (2) Dicarboxylic acid having an alkylene group having 2 to 4 carbon atoms (3) Divalent alcohol having an alkylene group having 2 to 6 carbon atoms

(1) Monohydric alcohol having an alkyl group having 1 to 4 carbon atoms The monohydric alcohol having an alkyl group having 1 to 4 carbon atoms is an alcohol containing R ¹ , specifically, methanol, Examples include ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, and tert-butanol. Among these, from the viewpoint of improving fluidity, impact resistance and bleed resistance, methanol, ethanol, 1-propanol and 1-butanol are preferable, methanol and ethanol are more preferable, and methanol is still more preferable.

(2) Dicarboxylic acid having an alkylene group having 2 to 4 carbon atoms The dicarboxylic acid having an alkylene group having 2 to 4 carbon atoms is a dicarboxylic acid containing R ² , specifically, succinic acid, Examples include glutaric acid, adipic acid, and derivatives thereof such as succinic anhydride, glutaric anhydride, dimethyl succinate, dibutyl succinate, dimethyl glutarate, dimethyl adipate, and the like. Of these, succinic acid, adipic acid and derivatives thereof such as succinic anhydride, dimethyl succinate, dibutyl succinate, and dimethyl adipate are preferable from the viewpoint of improving fluidity, impact resistance, and bleed resistance. More preferred are succinic acid and its derivatives, such as succinic anhydride, dimethyl succinate, and dibutyl succinate.

(3) Dihydric alcohol having an alkylene group having 2 to 6 carbon atoms The dihydric alcohol having an alkylene group having 2 to 6 carbon atoms is a dihydric alcohol containing R ³ , specifically, Ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,5-hexanediol, Examples include 1,6-hexanediol and 3-methyl-1,5-pentanediol. Of these, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, tetraethylene glycol, and 1,4-butanediol are used from the viewpoint of improving fluidity, impact resistance, and bleed resistance. Diethylene glycol, triethylene glycol, 1,2-propanediol and 1,3-propanediol are more preferable, and diethylene glycol, triethylene glycol and 1,3-propanediol are more preferable.

Therefore, as the above (1) to (3),
(1) the monohydric alcohol is one or more selected from the group consisting of methanol, ethanol, 1-propanol, and 1-butanol; (2) the dicarboxylic acid is succinic acid, adipic acid, glutaric acid, and One or more selected from the group consisting of these derivatives, (3) dihydric alcohol is diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, tetraethylene glycol, and It is preferably one or more selected from the group consisting of 1,4-butanediol,
(1) The monohydric alcohol is one or more selected from the group consisting of methanol and ethanol, and (2) the dicarboxylic acid is selected from the group consisting of succinic acid, adipic acid, and derivatives thereof, or And (3) the dihydric alcohol is one or more selected from the group consisting of diethylene glycol, triethylene glycol, 1,2-propanediol, and 1,3-propanediol. Preferably
(1) The monohydric alcohol is methanol, (2) the dicarboxylic acid is one or more selected from the group consisting of succinic acid and derivatives thereof, and (3) the dihydric alcohol is diethylene glycol, triethylene glycol, And one or more selected from the group consisting of 1,3-propanediol.

The method for obtaining the ester compound represented by the formula (I) using the above (1) to (3) is not particularly limited, and examples thereof include the following methods 1 and 2.
Aspect 1: (2) Step of synthesizing dicarboxylic acid ester by performing esterification reaction of (2) dicarboxylic acid with (1) monohydric alcohol, and (3) Step of esterifying reaction of obtained dicarboxylic acid ester with dihydric alcohol A method comprising the steps of: (1) monohydric alcohol, (2) dicarboxylic acid, and (3) dihydric alcohol reacting together

Among these, the method of aspect 1 is preferable from the viewpoint of adjusting the average degree of polymerization. In addition, reaction of each above-mentioned process can be performed in accordance with a well-known method.

The compound represented by formula (I) preferably has an acid value of 1.50 mgKOH / g or less, more preferably 1.00 mgKOH / g or less, from the viewpoint of improving fluidity, impact resistance and bleed resistance. From the viewpoint of productivity and economy, it is preferably 0.01 mgKOH / g or more, more preferably 0.05 mgKOH / g or more, and still more preferably 0.10 mgKOH / g or more. From the viewpoint of improving fluidity, impact resistance and bleed resistance, the hydroxyl value is preferably 10.0 mgKOH / g or less, more preferably 5.0 mgKOH / g or less, and still more preferably 3.0 mgKOH / g or less. From the viewpoint of productivity and economy, it is preferably 0.1 mgKOH / g or more, more preferably 0.3 mgKOH / g or more, and still more preferably 0.5 mgKOH / g or more. In addition, in this specification, the acid value and hydroxyl value of a plasticizer can be measured according to the method as described in the below-mentioned Example.

The number average molecular weight of the compound represented by the formula (I) is preferably 300 to 1500, more preferably 300 to 1000, from the viewpoint of improving fluidity, impact resistance and bleed resistance. In the present specification, the number average molecular weight of the plasticizer can be calculated according to the method described in Examples described later.

The saponification value of the compound represented by the formula (I) is preferably 500 to 800 mgKOH / g, more preferably 550 to 750 mgKOH / g from the viewpoint of improving fluidity, impact resistance and bleed resistance. In addition, in this specification, the saponification value of a plasticizer can be measured according to the method as described in the below-mentioned Example.

From the viewpoint of improving fluidity, impact resistance and bleed resistance, the compound represented by the formula (I) preferably has an alkyl esterification rate (terminal alkyl esterification rate) with respect to two molecular ends of 95%. Above, more preferably 98% or more. In the present specification, the terminal alkyl esterification rate of the plasticizer can be calculated according to the method described in Examples described later.

The ether group value of the compound represented by the formula (I) is preferably 0 to 8 mmol / g, more preferably 0 to 6 mmol / g, from the viewpoint of improving fluidity, impact resistance and bleed resistance. In the present specification, the ether group value of the plasticizer can be calculated according to the method described in Examples described later.

Compound group (C)
The compound represented by the formula (II) included in the compound group (C) is a polyether type phosphoric acid triester, which may be a symmetric structure or an asymmetric structure. Phosphoric triesters are preferred.

R ⁴ , R ⁵ , and R ⁶ each independently represents an alkyl group having 1 to 4 carbon atoms, and may be linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and an isobutyl group, and an ethyl group, a propyl group, and a butyl group are preferable. Further, from the viewpoint of improving the compatibility with the polylactic acid resin and improving the fluidity, impact resistance and bleed resistance, an alkyl group having 2 to 3 carbon atoms, that is, an ethyl group or a propyl group is more preferable.

A ¹ , A ² , and A ³ each independently represent an alkylene group having 2 or 3 carbon atoms, and may be linear or branched. Specific examples include an ethylene group, an n-propylene group, and an isopropylene group. Among them, from the viewpoint of improving compatibility with a polylactic acid resin and improving fluidity, impact resistance, and bleed resistance, An ethylene group is preferred. A ¹ , A ² , and A ³ form an oxyalkylene group (alkylene oxide) with an adjacent oxygen atom to form a repeating structure in the compound represented by the formula (II).

X, y, and z are each independently a positive number indicating the average added mole number of the oxyalkylene group, and x + y + z is a number exceeding 3 and satisfying 12 or less. Among these, from the viewpoint of improving compatibility with polylactic acid resin and improving fluidity, impact resistance and bleed resistance, x, y and z are positive numbers and x + y + z is 3. A number satisfying more than less than 12 is preferable, a number exceeding 4 and less than 12 is more preferable, and a number satisfying 6 or more and 9 or less is more preferable.

Therefore, as the compound represented by the formula (II),
(1) R ⁴ , R ⁵ and R ⁶ each independently represents an alkyl group having 1 to 4 carbon atoms, and A ¹ , A ² and A ³ each independently represents an alkylene group having 2 or 3 carbon atoms. , X, y, and z are each independently a positive number indicating the average number of added moles of the oxyalkylene group, and x + y + z is a number exceeding 3 and satisfying 12 or less,
(2) R ⁴ , R ⁵ , and R ⁶ each independently represent an alkyl group having 2 to 3 carbon atoms, A ¹ , A ² , and A ³ are all ethylene groups, and x, y, and z are positive And more preferably a compound in which x + y + z is more than 4 and less than 12;
(3) R ⁴ , R ⁵ and R ⁶ each independently represents an alkyl group having 2 to 3 carbon atoms, A ¹ , A ² and A ³ are all ethylene groups, and x, y and z are positive And a compound satisfying x + y + z of 6 or more and 9 or less is more preferable.

Specific examples of the compound represented by the formula (II) include tris (ethoxyethoxyethyl) phosphate [in the formula (II), R ⁴ , R ⁵ and R ⁶ are all ethyl groups, A ¹ , A ² , A ³ is an ethylene group, x, y and z are all 2; in addition to x + y + z = 6], tris (methoxyethoxyethyl) phosphate (x + y + z = 6), tris (propoxyethoxyethyl) phosphate (x + y + z = 6) ), Tris (butoxyethoxyethyl) phosphate (x + y + z = 6), tris (methoxyethoxyethoxyethyl) phosphate (x + y + z = 9), tris (ethoxyethoxyethoxyethyl) phosphate (x + y + z = 9), tris (propoxyethoxyethoxyethyl) Symmetric polyether type such as phosphate (x + y + z = 9) Phosphoric acid triester, bis (ethoxyethoxyethyl) methoxyethoxyethoxyethyl phosphate (x + y + z = 7), bis (methoxyethoxyethoxyethyl) ethoxyethoxyethyl phosphate (x + y + z = 8), bis (ethoxyethoxyethyl) butoxyethoxyethyl phosphate ( x + y + z = 6), etc., or a mixture of polyoxyethylene adducts or polyoxypropylene adducts of alcohols having 1 to 4 carbon atoms to satisfy the formula (II) Asymmetric polyether-type phosphate ester, tris (ethoxyethoxyethyl) phosphate, tris from the viewpoint of improving compatibility with polylactic acid resin and improving fluidity, impact resistance and bleed resistance Propoxy ethoxyethyl) phosphate, tris (ethoxyethoxy ethoxyethyl) phosphate, tris (propoxyethoxy ethoxyethyl) phosphate is preferred, tris (ethoxyethoxyethyl) phosphate is more preferable.

Among plasticizers, preferably one or two or more selected from the group consisting of polyester plasticizers, polyhydric alcohol ester plasticizers, polycarboxylic acid ester plasticizers, and phosphate ester plasticizers Or the content of an ester compound having a (poly) oxyalkylene group or an alkylene group having 2 to 6 (preferably 2 to 4) carbon atoms, more preferably a (poly) oxyalkylene group or 2 to 6 ( One or more selected from the group consisting of a polyester plasticizer, a polyhydric alcohol ester plasticizer, a polycarboxylic acid ester plasticizer, and a phosphate ester plasticizer, preferably having an alkylene group of 2-4) The content of two or more compounds, more preferably the content of one or more compounds selected from the group consisting of the compound groups (A) to (C), From the viewpoint of improving the compatibility with the resin and improving fluidity, impact resistance and bleed resistance, it is preferably 50% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and further preferably. Is substantially 100% by mass. In the present specification, the content of the plasticizer means the total content when a plurality of compounds are contained.

The content of the plasticizer is preferably 4 parts by mass or more, more preferably 5 parts by mass or more, and still more preferably 6 parts by mass with respect to 100 parts by mass of the polylactic acid resin, from the viewpoint of fluidity, durability and impact resistance. Part or more, more preferably 7 parts by weight or more, and from the viewpoint of flame retardancy, bleed resistance, durability and impact resistance, preferably 21 parts by weight or less, more preferably 18 parts by weight or less, still more preferably. It is 16 parts by mass or less, more preferably 14 parts by mass or less, and still more preferably 12 parts by mass or less.

In addition, the total mass of the triaryl phosphate and the plasticizer is 16 parts by mass or more, preferably 17 parts by mass with respect to 100 parts by mass of the polylactic acid resin from the viewpoint of fluidity, impact resistance, durability, and flame retardancy. Part or more, more preferably 18 parts by weight or more, still more preferably 19 parts by weight or more, and from the viewpoint of bleed resistance and durability, 30 parts by weight or less, preferably 28 parts by weight or less, more preferably 26 parts by weight or less. More preferably, it is 24 parts by mass or less, and still more preferably 22 parts by mass or less.
The total mass of the triaryl phosphate and the plasticizer is preferably 18 parts by mass or more and 30 parts by mass or less, more preferably 23 parts by mass or more and 28 parts by mass with respect to 100 parts by mass of the polylactic acid resin. From the viewpoint of impact resistance and durability, preferably from 18 parts by weight to 30 parts by weight, more preferably from 18 parts by weight to 24 parts by weight, and from the viewpoint of bleed resistance, preferably 16 parts by weight. The weight is from 24 parts by weight to 24 parts by weight, more preferably from 16 parts by weight to 22 parts by weight. From the viewpoint of fluidity, impact resistance, flame retardancy and bleed resistance, preferably from 18 parts by weight to 24 parts by weight. More preferably, it is 19 parts by mass or more and 22 parts by mass or less.

The mass ratio of the plasticizer to the triaryl phosphate (plasticizer / triaryl phosphate) is preferably 0.30 or more, more preferably 0.35 or more, and further preferably from the viewpoint of impact resistance and bleed resistance. 0.38 or more, more preferably 0.40 or more, still more preferably 0.50 or more, still more preferably 0.55 or more, and still more preferably 0.60 or more, and flame retardancy and impact resistance From the viewpoint of bleed resistance, it is preferably 3.5 or less, more preferably 3.0 or less, further preferably 2.5 or less, further preferably 2.0 or less, still more preferably 1.5 or less, and still more preferably. 1.0 or less, more preferably 0.80 or less, and still more preferably 0.75 or less.
Further, the mass ratio of the plasticizer to the triaryl phosphate (plasticizer / triaryl phosphate) is preferably 0.30 or more and 0.80 or less, more preferably 0.30 or more and 0.60 or less, from the viewpoint of fluidity. More preferably, it is 0.30 or more and 0.50 or less, and from the viewpoint of flame retardancy, it is preferably 0.30 or more and 3.0 or less, more preferably 0.30 or more and 2.0 or less, and further preferably 0.30. From the viewpoint of bleed resistance, preferably from 0.35 to 3.0, more preferably from 0.35 to 2.0, and still more preferably from 0.38 to 1.5. Yes, from the viewpoint of fluidity, impact resistance, flame retardancy, bleed resistance and durability, preferably 0.35 or more and 3.0 or less, more preferably 0.40 or more and 0.80 or less, and still more preferably 0. .50 or more .75 or less, still more preferably 0.55 to 0.75.

[Surface-treated metal hydroxide]
Examples of the metal hydroxide in the surface-treated metal hydroxide include aluminum hydroxide, magnesium hydroxide, calcium hydroxide and the like. Of these, aluminum hydroxide and magnesium hydroxide are preferred, and aluminum hydroxide is more preferred from the viewpoint of impact resistance, flame retardancy and durability of the polylactic acid resin composition.

Examples of the surface treatment applied to the metal hydroxide include surface treatment using a silane coupling agent, a higher fatty acid, a titanate coupling agent, a sol-gel coating agent, a silicone polymer coating agent, a resin coating agent, and nitrate. Can be mentioned. Among these, from the viewpoint of improving the fluidity, impact resistance and durability of the polylactic acid resin composition, surface treatment with a silane coupling agent is preferable.

Therefore, as the surface-treated metal hydroxide in the present invention, aluminum hydroxide and magnesium hydroxide treated with a silane coupling agent are preferable from the viewpoints of fluidity, impact resistance, flame retardancy and durability. More preferred is aluminum hydroxide treated with a silane coupling agent.

Examples of the silane coupling agent in the present invention include coupling agents such as isocyanate silane, amino silane, mercapto silane, epoxy silane, vinyl silane, methacryl silane, and epoxy silane. Among these, from the viewpoint of enhancing the fluidity, bleed resistance, impact resistance, flame retardancy and durability of the polylactic acid resin composition, a coupling agent of isocyanate silane, amino silane, mercapto silane, and epoxy silane is preferable. Silane and aminosilane are more preferable, and isocyanate silane is still more preferable.

Examples of the isocyanate silane include 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, tris- (3-trimethoxysilylpropyl) isocyanurate, and the like.

Examples of aminosilanes include γ-aminopropyltriethoxysilane, n-β (aminoethyl) γ-aminopropyltriethoxysilane, and the like.

Examples of mercaptosilane include 3-mercaptopropyltrimethoxysilane.

Examples of the epoxy silane include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane.

The metal hydroxide subjected to the surface treatment with the silane coupling agent is, for example, sprayed or coated on the surface of the metal hydroxide with a solution obtained by dissolving the silane coupling agent in a solvent such as acetone, ethyl acetate, or toluene. After the processing, it can be obtained by a method such as drying to remove the solvent.

A metal hydroxide subjected to a surface treatment with a silane coupling agent is used to improve the fluidity, flame retardancy, bleed resistance, durability and impact resistance of the polylactic acid resin composition. What processed the mass ratio (silane coupling agent / metal hydroxide) with a hydroxide in the ratio of 0.1 / 99.9-5 / 95 is preferable, and 0.3 / 99.7-3 / 97 More preferably, it is processed as a ratio of 0.5 / 99.5 to 2/98.

The surface-treated metal hydroxide has an average particle diameter of preferably 0.5 μm or more, more preferably 1 μm or more, and further preferably 2 μm or more from the viewpoint of flame retardancy and fluidity, and impact resistance. And from a viewpoint of durability, Preferably it is 10 micrometers or less, More preferably, it is 5 micrometers or less, More preferably, it is 4 micrometers or less. This average particle size means a volume median particle size (D ₅₀ ), and is measured by using a laser diffraction / scattering type particle size distribution analyzer “Mastersizer 2000” (manufactured by Malvern). (ExxonMobil Co., Ltd.) was added, and at a concentration such that the scattering intensity was 5 to 15%, the volume median was obtained under the conditions of a particle refractive index of 1.58 (imaginary part 0.1) and a dispersion medium refractive index of 1.42. The particle size (D ₅₀ ) is measured.

In the present invention, the surface-treated metal hydroxide can be used alone or in combination of two or more, and from the viewpoint of balance between fluidity and impact resistance, metal hydroxides having different average particle diameters are used in combination. can do. The difference in average particle diameter is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 3 μm or less, more preferably 2 μm or less.

The content of the surface-treated metal hydroxide with respect to 100 parts by mass of the polylactic acid resin is 10 parts by mass from the viewpoint of improving the flame retardancy and impact resistance of the polylactic acid resin composition and the bleed resistance of the plasticizer or triaryl phosphate. Or more, preferably 25 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 35 parts by mass or more, and still more preferably 38 parts by mass or more, from the viewpoint of fluidity, durability and impact resistance. It is not more than part by mass, preferably not more than 80 parts by mass, more preferably not more than 60 parts by mass, still more preferably not more than 50 parts by mass.
The content of the surface-treated metal hydroxide with respect to 100 parts by mass of the polylactic acid resin is preferably 10 parts by mass or more and 80 parts by mass from the viewpoint of fluidity, flame retardancy, impact resistance, bleed resistance and durability. Hereinafter, more preferably 25 parts by mass or more and 60 parts by mass or less, further preferably 30 parts by mass or more and 50 parts by mass or less, and still more preferably 38 parts by mass or more and 50 parts by mass or less.
In the present specification, the content of the surface-treated metal hydroxide means the total content when a plurality of surface-treated metal hydroxides are contained.

[Melamine compound]
The melamine compound used in the present invention is a compound having a melamine skeleton in the structure, and forms a salt. Examples of melamine compounds include melamine phosphate, dimelamine phosphate, melamine polyphosphate, melamine pyrophosphate, melamine phthalate, melamine phthalimide, melamine borate, melamine ammonium phosphate, melamine ammonium polyphosphate, melamine cyanurate, melamine isocyanate Examples include nurate. Of these, melamine polyphosphate, melamine cyanurate, and melamine isocyanurate are preferred, considering the impact resistance, flame retardancy, durability, and bleed resistance of the polylactic acid resin composition containing the melamine compound. And / or melamine isocyanurate is more preferred.

The content of the melamine compound in the polylactic acid resin composition is 10 parts by mass or more, preferably 20 parts by mass with respect to 100 parts by mass of the polylactic acid resin, from the viewpoints of fluidity, bleed resistance, flame retardancy and durability. Above, more preferably 35 parts by mass or more, from the viewpoint of fluidity and impact resistance, 100 parts by mass or less, preferably 90 parts by mass or less, more preferably 80 parts by mass or less, still more preferably 60 parts by mass or less, More preferably, it is 55 mass parts or less, More preferably, it is 45 mass parts or less.
The content of the melamine compound is preferably 20 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the polylactic acid resin from the viewpoints of fluidity, flame retardancy, impact resistance, bleed resistance and durability. More preferably, they are 30 to 90 mass parts, More preferably, they are 30 to 60 mass parts, More preferably, they are 30 to 45 mass parts.

The total content of the melamine compound and the surface-treated metal hydroxide in the polylactic acid resin composition is preferably from 100 parts by mass of the polylactic acid resin from the viewpoint of bleed resistance, flame retardancy, and durability. Is 40 parts by mass or more, more preferably 50 parts by mass or more, more preferably 60 parts by mass or more, still more preferably 70 parts by mass or more, and still more preferably 75 parts by mass or more, and has fluidity, impact resistance and durability. From the viewpoint, preferably 140 parts by mass or less, more preferably 130 parts by mass or less, still more preferably 120 parts by mass or less, still more preferably 110 parts by mass or less, still more preferably 105 parts by mass or less, and still more preferably 90 parts by mass. Or less.

The mass ratio of the surface-treated metal hydroxide to the melamine compound (surface-treated metal hydroxide / melamine compound) is preferably 0.12 or more from the viewpoint of fluidity, impact resistance and durability. Preferably it is 0.15 or more, More preferably, it is 0.50 or more, More preferably, it is 0.80 or more, From the same viewpoint, Preferably it is 8.0 or less, More preferably, it is 6.0 or less, More preferably, it is 3 0.0 or less, more preferably 2.0 or less, and even more preferably 1.5 or less.

[Organic crystal nucleating agent]
In addition, the polylactic acid resin composition of the present invention contains an organic crystal nucleating agent from the viewpoint of improving the crystallization speed of the polylactic acid resin, improving the crystallinity of the polylactic acid resin, and improving the impact resistance. Can do.

As the organic crystal nucleating agent in the present invention, it is preferable to use one or more organic crystal nucleating agents selected from the group consisting of the following (a) to (d).
(A) From the group consisting of a compound having an isoindolinone skeleton, a compound having a diketopyrrolopyrrole skeleton, a compound having a benzimidazolone skeleton, a compound having an indigo skeleton, a compound having a phthalocyanine skeleton, and a compound having a porphyrin skeleton One or more organic compounds selected [referred to as organic crystal nucleating agent (a)]
(B) One or more organic compounds selected from the group consisting of carbohydrazides, uracils, and N-substituted ureas (referred to as organic crystal nucleating agent (b))
(C) 1 selected from the group consisting of metal salts of sulfoaromatic carboxylic acid esters, metal salts of phosphoric acid esters, metal salts of phenylphosphonic acid, metal salts of rosin acids, aromatic carboxylic acid amides, and rosin acid amides Species or two or more organic compounds [referred to as organic crystal nucleating agent (c)]
(D) One or more organic compounds selected from the group consisting of a compound having a hydroxyl group and an amide group in the molecule and a hydroxy fatty acid ester [referred to as organic crystal nucleating agent (d)]

Among these, from the viewpoint of improving impact resistance, the organic crystal nucleating agent (c) and the organic crystal nucleating agent (d) are preferable.

From the above viewpoint, the organic crystal nucleating agent (c) is preferably a phenylphosphonic acid metal salt having an optionally substituted phenyl group and a phosphonic group (—PO (OH) ₂ ). Examples of the substituent include an alkyl group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms in an alkoxy group, and the like. Specific examples of phenylphosphonic acid include unsubstituted phenylphosphonic acid, methylphenylphosphonic acid, ethylphenylphosphonic acid, propylphenylphosphonic acid, butylphenylphosphonic acid, dimethoxycarbonylphenylphosphonic acid, and diethoxycarbonylphenylphosphonic acid. And unsubstituted phenylphosphonic acid is preferred.

Examples of the metal salt of phenylphosphonic acid include salts of lithium, sodium, magnesium, aluminum, potassium, calcium, barium, copper, zinc, iron, cobalt, nickel, and the like. From the above viewpoint, a zinc salt is preferable.

From the above viewpoint, the compound having a hydroxyl group and an amide group in the molecule of the organic crystal nucleating agent (d) is preferably an aliphatic amide having a hydroxyl group, having two or more hydroxyl groups in the molecule, and having two amide groups. An aliphatic amide having two or more is more preferable. Specific examples include hydroxy fatty acid monoamides such as 12-hydroxy stearic acid monoethanolamide, methylene bis 12-hydroxy stearic acid amide, ethylene bis 12-hydroxy stearic acid amide, hexamethylene bis 12-hydroxy stearic acid amide and the like. Etc.

Further, the hydroxy fatty acid ester of the organic crystal nucleating agent (d) is preferably a hydroxy fatty acid ester having 12 to 22 carbon atoms of the fatty acid, having a hydroxy group having two or more hydroxyl groups and two or more ester groups in the molecule. Fatty acid esters are more preferred. Specific examples include 12-hydroxystearic acid triglyceride, 12-hydroxystearic acid diglyceride, 12-hydroxystearic acid monoglyceride, pentaerythritol mono-12-hydroxystearate, pentaerythritol di-12-hydroxystearate, pentaerythritol. -Hydroxy fatty acid esters such as tri-12-hydroxystearate.

These may be used alone or in combination of two or more thereof, and among these, from the viewpoint of improving impact resistance, it is more preferable to use (c) and (d) in combination, and a hydroxyl group in the molecule. More preferably, a compound having an amide group and a metal salt of phenylphosphonic acid are used in combination, more preferably a hydroxy fatty acid bisamide and a metal salt of unsubstituted phenylphosphonic acid are used in combination, and ethylene bis 12-hydroxystearic acid amide. It is even more preferable to use an unsubstituted zinc salt of phenylphosphonic acid in combination.

In addition, the mass ratio of the hydroxy fatty acid bisamide and the metal salt of phenylphosphonic acid (hydroxy fatty acid bisamide / phenylphosphonic acid metal salt) increases the crystallization speed of the polylactic acid resin, from the viewpoint of improving impact resistance, Preferably it is 0.2 or more, More preferably, it is 0.3 or more, More preferably, it is 0.5 or more, Preferably it is 6 or less, More preferably, it is 4 or less, More preferably, it is 2 or less.

From the viewpoint of improving impact resistance by increasing the crystallization rate of the polylactic acid resin, the content of the organic crystal nucleating agent is preferably 0.1 parts by mass or more with respect to 100 parts by mass of the polylactic acid resin. .3 parts by mass or more is more preferable, 0.5 parts by mass or more is further preferable, 5 parts by mass or less is preferable, 3 parts by mass or less is more preferable, and 2.5 parts by mass or less is still more preferable. In the present specification, the content of the organic crystal nucleating agent means the total content of all the organic crystal nucleating agents contained in the polylactic acid resin composition.

[Hydrolysis inhibitor]
In addition, from the viewpoint of improving flame retardancy and impact resistance, the polylactic acid resin composition of the present invention may further contain a hydrolysis inhibitor as appropriate in addition to the above components.

Examples of the hydrolysis inhibitor include carbodiimide compounds such as polycarbodiimide compounds and monocarbodiimide compounds.

Examples of the polycarbodiimide compound include poly (4,4′-diphenylmethanecarbodiimide), poly (4,4′-dicyclohexylmethanecarbodiimide), poly (1,3,5-triisopropylbenzene) polycarbodiimide, poly (1,3,3). 5-triisopropylbenzene and 1,3-diisopropylbenzene) polycarbodiimide and the like, and examples of the monocarbodiimide compound include N, N′-di-2,6-diisopropylphenylcarbodiimide and the like.

The carbodiimide compounds may be used alone or in combination of two or more. Poly (4,4′-dicyclohexylmethane carbodiimide) is obtained by converting carbodilite LA-1 (manufactured by Nisshinbo Chemical Co., Ltd.), (Isopropylbenzene and 1,3-diisopropylbenzene) polycarbodiimide is stavaxol P and stabaxol P-100 (manufactured by Rhein Chemie), N, N'-di-2,6-diisopropylphenylcarbodiimide is stavaxol I (Rhein Chemie) Can be purchased and used.

The content of the hydrolysis inhibitor is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, with respect to 100 parts by mass of the polylactic acid resin, from the viewpoint of improving flame retardancy and impact resistance. More preferably, it is 1 part by mass or more, preferably 7 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 3 parts by mass or less.

The polylactic acid resin composition of the present invention includes organic fillers, flame retardants, antioxidants, hydrocarbon waxes and lubricants that are anionic surfactants, ultraviolet absorbers, antistatic agents, in addition to the above components. An agent, an antifogging agent, a light stabilizer, a pigment, an antifungal agent, an antibacterial agent, a foaming agent, and the like can be contained as long as the effects of the present invention are not impaired. Moreover, it is also possible to contain other polymer materials and other resin compositions as long as the effects of the present invention are not impaired. In addition, these content is not specifically limited, According to a well-known technique, it can set suitably. For example, from the viewpoint of enhancing flame retardancy, the content of the organic filler is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less with respect to 100 parts by mass of the polylactic acid resin. More preferably, it is preferably 1 part by mass or less, and still more preferably substantially not blended. Examples of organic fillers include plant-derived compounds such as cellulose and bagasse.

[Production of polylactic acid resin composition]
The polylactic acid resin composition of the present invention contains a polylactic acid resin, a triaryl phosphate having a specific structure, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, and is based on 100 parts by mass of the polylactic acid resin. The total content of the triaryl phosphate and the plasticizer is 16 to 30 parts by mass, the content of the surface-treated metal hydroxide is 10 to 100 parts by mass, and the content of the melamine compound is 10 to 100 parts by mass. Prepared by melting and kneading the raw materials containing various components, if necessary, using a known kneader such as a closed kneader, a single or twin screw extruder, and an open roll kneader. can do. After the melt-kneading, the melt-kneaded product may be dried or cooled according to a known method. In addition, the raw materials can be subjected to melt kneading after being uniformly mixed in advance using a Henschel mixer, a super mixer, or the like. In order to promote the plasticity of the polylactic acid resin during melt kneading, it may be melt-mixed in the presence of a supercritical gas.

The melt kneading temperature is preferably 160 ° C. or higher, more preferably 165 ° C. or higher, further preferably 170 ° C. or higher, from the viewpoint of improving the moldability and deterioration prevention of the polylactic acid resin composition. From the viewpoint of suppressing decomposition, it is preferably 230 ° C. or lower, more preferably 220 ° C. or lower, and further preferably 215 ° C. or lower. The melt-kneading time cannot be generally determined depending on the melt-kneading temperature and the type of the kneader, but is preferably 15 to 900 seconds.

[Manufacture of molded products]
The polylactic acid resin composition of the present invention has excellent fluidity and good processability, and can be formed into various molded articles according to known methods. As a molding method, a known method can be used. For example, by molding the polylactic acid resin composition of the present invention by injection molding, a molded article excellent in impact resistance, bleed resistance and flame retardancy is provided. be able to. Therefore, this invention also provides the molded object obtained by injection-molding the polylactic acid resin composition of this invention.

The injection-molded body can be molded, for example, by filling the polylactic acid resin composition of the present invention into a mold having a desired shape using an injection molding machine.

[Injection molding machine]
As the injection molding, a known injection molding machine can be used. For example, one having a cylinder and a screw inserted through the cylinder as main components [J110AD-180H, J75E-D (both manufactured by Nippon Steel Works), etc.] can be mentioned. In addition, although the raw material of the polylactic acid resin composition of the present invention may be supplied to a cylinder and melt-kneaded as it is, it is preferable to fill an injection molding machine with a melt-kneaded material in advance. That is, after the polylactic acid resin composition of the present invention is melt-kneaded, it is preferably filled into a mold having a desired shape using an injection molding machine and molded.

The set temperature of the cylinder is preferably 180 ° C. or higher from the viewpoint of injection moldability, and preferably 220 ° C. or lower, more preferably 210 ° C. from the viewpoint of suppressing deterioration of the polylactic acid resin and decomposition of triaryl phosphate. ° C or lower, more preferably 200 ° C or lower. When an injection molding machine equipped with a melt kneader is used, it means the set temperature of the cylinder of the kneader during melt kneading. The cylinder is equipped with a heater, and the temperature is adjusted accordingly. Although the number of heaters varies depending on the model and is not determined unconditionally, the heater adjusted to the set temperature is preferably at least on the melt-kneaded product discharge port side (nozzle tip side).

The mold temperature is preferably 110 ° C. or lower, more preferably 100 ° C. or lower, still more preferably 90 ° C. or lower, and still more preferably 80 ° C. or lower, from the viewpoint of improving workability and reducing production costs. Moreover, from a viewpoint of the improvement of impact resistance by the improvement of crystallization speed, 30 degreeC or more is preferable, 40 degreeC or more is more preferable, and 60 degreeC or more is still more preferable. Since the polylactic acid resin composition of the present invention has an excellent crystallization rate and can be molded at a low temperature, a molded product having sufficient heat resistance can be obtained even at the mold temperature.

The holding time in the mold is not particularly limited, but is preferably 3 seconds or more, more preferably from the viewpoint of improving the impact resistance by crystallization, from the viewpoint of productivity of a molded article made of the polylactic acid resin composition. Is 10 seconds or longer, more preferably 20 seconds or longer, and preferably 90 seconds or shorter, more preferably 80 seconds or shorter, still more preferably 70 seconds or shorter, from the viewpoint of improving workability and reducing production costs.

The method for producing the molded body is not particularly limited as long as it includes a step of injection-molding the polylactic acid resin composition of the present invention. Depending on the type of the molded product to be obtained, a step may be added as appropriate. it can.

Specifically, the aspect containing the following processes is mentioned.
Step (1): A polylactic acid resin composition comprising a polylactic acid resin and a triaryl phosphate, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, wherein the triaryl phosphate is carbon. A surface treatment wherein the total content of the triaryl phosphate and the plasticizer is 16 to 30 parts by mass with respect to 100 parts by mass of the polylactic acid resin. The polylactic acid resin composition having an amount of 10 to 100 parts by mass of the metal hydroxide and 10 to 100 parts by mass of the melamine compound is melt-kneaded to obtain a polylactic acid resin composition. Step (2) for preparing a melt-kneaded product: a step of injection-molding the melt-kneaded product of the polylactic acid resin composition obtained in step (1) into a mold

Step (1) is a step of preparing a melt-kneaded product of the polylactic acid resin composition. Specifically, it contains a polylactic acid resin, a triaryl phosphate, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, wherein the triaryl phosphate has an alkyl group having 1 to 3 carbon atoms. The total content of the triaryl phosphate and the plasticizer is 16 to 30 parts by mass, and the content of the surface-treated metal hydroxide is 10 with respect to 100 parts by mass of the polylactic acid resin. It can be prepared by melt-kneading a raw material having an amount of ˜100 parts by mass and a melamine compound content of 10 to 100 parts by mass at the aforementioned preferred melt-kneading temperature.

Step (2) is a step of injection molding a melt-kneaded product of the polylactic acid resin composition. Specifically, the melt-kneaded product obtained in the step (1) is preferably filled into an injection molding machine equipped with a cylinder heated to the above-mentioned preferable cylinder set temperature, and the inside of the mold at the above-mentioned preferable mold temperature is filled. Can be injected and molded.

The molded article of the polylactic acid resin composition of the present invention thus obtained is excellent in impact resistance, bleed resistance, flame retardancy, and durability, and can be suitably used as home appliance parts such as a casing of information home appliances. .

The flame retardancy of the molded article of the present invention is preferably V-1 or more, more preferably V-0, when measured by the method described in the Examples. Similarly, as for the fluidity | liquidity of the molded object of this invention, L / D is preferably 145 or more, and more preferably 160 or more. Similarly, the impact resistance of the molded article of the present invention is preferably 60 cm or more, more preferably 75 cm or more, and still more preferably 90 cm or more. Similarly, the bleed resistance of the molded article of the present invention is preferably B or more, and more preferably A. Similarly, the durability of the molded article of the present invention is preferably 70% or more, more preferably 75% or more, and still more preferably 80% or more.

This invention discloses the following polylactic acid resin compositions further regarding embodiment mentioned above.
<1> A polylactic acid resin composition comprising a polylactic acid resin, a triaryl phosphate, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, wherein the triaryl phosphate has 1 to 3 carbon atoms. The surface-treated metal comprising at least one alkylaryl group having the above alkyl group, wherein the total mass of the triaryl phosphate and the plasticizer is 16 to 30 parts by mass with respect to 100 parts by mass of the polylactic acid resin. The hydroxide content is 10 to 100 parts by mass with respect to 100 parts by mass of the polylactic acid resin, and the melamine compound content is 10 to 100 parts by mass with respect to 100 parts by mass of the polylactic acid resin. Polylactic acid resin composition.

<2> Triaryl phosphates have the general formula:
(R ⁷ R ⁸ ArO) _a (ArO) _3-a PO
(In the formula, Ar represents a benzene ring, and R ⁷ and R ⁸ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, except that both are hydrogen atoms; Represents an integer of ~ 3)
The polylactic acid resin composition as described in said <1> whose compound represented by these is preferable.
<3> As R ⁷ and R ⁸ in the above formula, when both are methyl groups, when R ⁷ is a methyl group and R ⁸ is a hydrogen atom, R ⁷ is an ethyl group and R ⁸ is a hydrogen atom. In some cases, R ⁷ is preferably an isopropyl group and R ⁸ is a hydrogen atom. When R ⁷ is a methyl group and R ⁸ is a hydrogen atom, R ⁷ is an isopropyl group and R ⁸ is a hydrogen atom. The polylactic acid resin composition according to <2>, which is more preferable.
<4> The triaryl phosphate represented by the above formula is a compound containing an alkylaryl group having an alkyl group having 1 to 3 carbon atoms, preferably 1 to 2, more preferably 1, 3> The polylactic acid resin composition described in 3>.
<5> The triaryl phosphate represented by the above formula includes trixylenyl phosphate, tricresyl phosphate, dixylenyl phenyl phosphate, dicresyl phenyl phosphate, xylenyl diphenyl phosphate, isopropylphenyl diphenyl phosphate, and cresyl The polylactic acid resin composition according to any one of <2> to <4>, wherein one or more selected from the group consisting of diphenyl phosphate is preferable, and isopropylphenyl diphenyl phosphate and / or cresyl diphenyl phosphate are more preferable. .
<6> The content of triaryl phosphate in the polylactic acid resin composition is preferably 5 parts by mass or more, more preferably 6 parts by mass or more, still more preferably 8 parts by mass or more, relative to 100 parts by mass of the polylactic acid resin. More preferably, it exceeds 10 parts by mass, preferably 21 parts by mass or less, more preferably 18 parts by mass or less, still more preferably 16 parts by mass or less, and still more preferably 14 parts by mass or less, <1><5> The polylactic acid resin composition according to any one of the above.
<7> The plasticizer is preferably one or two selected from the group consisting of polyester plasticizers, polyhydric alcohol ester plasticizers, polycarboxylic acid ester plasticizers, and phosphate ester plasticizers. Any of the above <1> to <6>, except that the phosphate ester plasticizer excludes a triaryl phosphate containing one or more alkylaryl groups having an alkyl group having 1 to 3 carbon atoms. A polylactic acid resin composition according to claim 1.
<8> The plasticizer is preferably an ester compound having a (poly) oxyalkylene group or an alkylene group having 2 to 6 carbon atoms (preferably 2 to 4 carbon atoms), and a (poly) oxyalkylene group or 2 to 6 carbon atoms ( One or more selected from the group consisting of a polyester plasticizer, a polyhydric alcohol ester plasticizer, a polycarboxylic acid ester plasticizer, and a phosphate ester plasticizer, preferably having an alkylene group of 2-4) The polylactic acid resin composition according to any one of <1> to <7>, wherein two or more are more preferable.
<9> The plasticizer is preferably one or more selected from the group consisting of the following compound groups (A) to (C), and when used in combination of two or more, the same compound group is also different. The polylactic acid resin composition according to any one of <1> to <8>, which may be a group of compounds.
Compound group (A) An ester compound having two or more ester groups in the molecule, wherein at least one of the alcohol components constituting the ester compound is an average of 2 to 3 alkylene oxides per hydroxyl group. Ester compound group (B) which is an alcohol added with 5 to 5 moles Formula (I):
R ¹ O—CO—R ² —CO — [(OR ³ ) _m O—CO—R ² —CO—] _n OR ¹ (I)
(Wherein R ¹ is an alkyl group having 1 to 4 carbon atoms, R ² is an alkylene group having 2 to 4 carbon atoms, R ³ is an alkylene group having 2 to 6 carbon atoms, and m is 1 to 6) And n represents a number from 1 to 12, provided that all R ² may be the same or different, and all R ³ may be the same or different.
Compound group (C) represented by formula (II):

(Wherein R ⁴ , R ⁵ and R ⁶ each independently represents an alkyl group having 1 to 4 carbon atoms, and A ¹ , A ² and A ³ each independently represents an alkylene group having 2 or 3 carbon atoms) X, y and z are each independently a positive number indicating the average number of moles added of the oxyalkylene group, and x + y + z is a number exceeding 3 and satisfying 12 or less)
Compound <10> represented by the formula: As the compound group (A), an ester of acetic acid and glycerin with an average of 3 to 6 moles of ethylene oxide adduct (1 to 2 moles of ethylene oxide added per hydroxyl group), acetic acid and ethylene Esters of polyethylene glycol with an average addition mole number of oxide of 4 to 6, polyethylene glycol monomethyl ether with an average addition mole number of succinic acid and ethylene oxide of 2 to 3 (addition of 2 to 3 moles of ethylene oxide per hydroxyl group) The polylactic acid resin composition according to the above item <9>, wherein an ester of adipic acid with diethylene glycol monomethyl ether, or an ester of 1,3,6-hexanetricarboxylic acid with diethylene glycol monomethyl ether is preferred.
<11> The compound group (B) includes at least one dibasic acid selected from succinic acid, glutaric acid, and adipic acid, diethylene glycol, triethylene glycol, 1,2-propanediol, and 1,3-propane The polylactic acid resin composition according to <9>, wherein an oligoester of at least one dihydric alcohol selected from diol is preferable [in formula (I), n = 1.2 to 3].
<12> As the compound group (C), tris (ethoxyethoxyethyl) phosphate [in the formula (II), R ⁴ , R ⁵ and R ⁶ are all ethyl groups, and A ¹ , A ² and A ³ are all Ethylene group, x, y, z are all 2, and in addition to x + y + z = 6], tris (methoxyethoxyethyl) phosphate (x + y + z = 6), tris (propoxyethoxyethyl) phosphate (x + y + z = 6), tris ( Butoxyethoxyethyl) phosphate (x + y + z = 6), tris (methoxyethoxyethoxyethyl) phosphate (x + y + z = 9), tris (ethoxyethoxyethoxyethyl) phosphate (x + y + z = 9), tris (propoxyethoxyethoxyethyl) phosphate (x + y + z = 9) Symmetric polyether-type triphosphates such as Steal or bis (ethoxyethoxyethyl) methoxyethoxyethoxyethyl phosphate (x + y + z = 7), bis (methoxyethoxyethoxyethyl) ethoxyethoxyethyl phosphate (x + y + z = 8), bis (ethoxyethoxyethyl) butoxyethoxyethyl phosphate (x + y + z = 6) ), Etc., or a mixture of a polyoxyethylene adduct or a polyoxypropylene adduct of an alcohol having 1 to 4 carbon atoms with a phosphoric acid triester so as to satisfy the formula (II) Polyether phosphates are preferred, such as tris (ethoxyethoxyethyl) phosphate, tris (propoxyethoxyethyl) phosphate, tris (ethoxyethoxyethoxyethyl) phosphate, tris ( The polylactic acid resin composition according to <9>, wherein propoxyethoxyethoxyethyl) phosphate is more preferable, and tris (ethoxyethoxyethyl) phosphate is further preferable.
<13> Among plasticizers, preferably one or two selected from the group consisting of polyester plasticizers, polyhydric alcohol ester plasticizers, polycarboxylic acid ester plasticizers, and phosphate ester plasticizers. The above content, or the content of an ester compound having a (poly) oxyalkylene group or an alkylene group having 2 to 6 (preferably 2 to 4) carbon atoms, more preferably a (poly) oxyalkylene group or 2 carbon atoms. Selected from the group consisting of polyester plasticizers, polyhydric alcohol ester plasticizers, polycarboxylic acid ester plasticizers, and phosphate ester plasticizers having 6 to 6 (preferably 2 to 4) alkylene groups The content of one or more compounds, more preferably the content of one or more compounds selected from the group consisting of the compound groups (A) to (C), The polylactic acid according to any one of <8> to <12>, preferably 50% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, and further preferably substantially 100% by mass. Resin composition.
<14> The content of the plasticizer is preferably 4 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 6 parts by mass or more, and still more preferably 7 parts by mass with respect to 100 parts by mass of the polylactic acid resin. The above is preferably 21 parts by mass or less, more preferably 18 parts by mass or less, still more preferably 16 parts by mass or less, still more preferably 14 parts by mass or less, and still more preferably 12 parts by mass or less. >-<13> The polylactic acid resin composition according to any one of the above.
<15> The total mass of the triaryl phosphate and the plasticizer is preferably 17 parts by mass or more, more preferably 18 parts by mass or more, and still more preferably 19 parts by mass or more, with respect to 100 parts by mass of the polylactic acid resin. Is 28 parts by mass or less, more preferably 26 parts by mass or less, still more preferably 24 parts by mass or less, and still more preferably 22 parts by mass or less. The polylactic acid resin composition according to any one of <1> to <14> object.
<16> The total mass of the triaryl phosphate and the plasticizer is preferably 18 parts by mass or more and 30 parts by mass or less, more preferably 23 parts by mass or more and 28 parts by mass or less, relative to 100 parts by mass of the polylactic acid resin. The polylactic acid resin composition according to any one of <1> to <15>.
<17> The total mass of the triaryl phosphate and the plasticizer is preferably 18 parts by mass or more and 30 parts by mass or less, more preferably 18 parts by mass or more and 24 parts by mass or less, relative to 100 parts by mass of the polylactic acid resin. The polylactic acid resin composition according to any one of <1> to <15>.
<18> The total mass of the triaryl phosphate and the plasticizer is preferably 16 parts by mass or more and 24 parts by mass or less, more preferably 16 parts by mass or more and 22 parts by mass or less, relative to 100 parts by mass of the polylactic acid resin. The polylactic acid resin composition according to any one of <1> to <15>.
<19> The total mass of the triaryl phosphate and the plasticizer is preferably 18 parts by mass or more and 24 parts by mass or less, more preferably 19 parts by mass or more and 22 parts by mass or less, relative to 100 parts by mass of the polylactic acid resin. The polylactic acid resin composition according to any one of <1> to <15>.
<20> The mass ratio of the plasticizer to the triaryl phosphate (plasticizer / triaryl phosphate) is preferably 0.30 or more, more preferably 0.35 or more, still more preferably 0.38 or more, and even more preferably 0. .40 or more, more preferably 0.50 or more, still more preferably 0.55 or more, still more preferably 0.60 or more, preferably 3.5 or less, more preferably 3.0 or less, still more preferably Is 2.5 or less, more preferably 2.0 or less, more preferably 1.5 or less, still more preferably 1.0 or less, still more preferably 0.80 or less, and still more preferably 0.75 or less. The polylactic acid resin composition according to any one of <1> to <19>.
<21> The mass ratio of the plasticizer to the triaryl phosphate (plasticizer / triaryl phosphate) is preferably 0.30 or more and 0.80 or less, more preferably 0.30 or more and 0.60 or less, and still more preferably 0.8. The polylactic acid resin composition according to any one of <1> to <20>, which is 30 or more and 0.50 or less.
<22> The mass ratio of the plasticizer to the triaryl phosphate (plasticizer / triaryl phosphate) is preferably 0.30 or more and 3.0 or less, more preferably 0.30 or more and 2.0 or less, and still more preferably 0.8. The polylactic acid resin composition according to any one of <1> to <20>, which is 30 or more and 1.0 or less.
<23> The mass ratio of the plasticizer to the triaryl phosphate (plasticizer / triaryl phosphate) is preferably 0.35 or more and 3.0 or less, more preferably 0.35 or more and 2.0 or less, and still more preferably 0.8. The polylactic acid resin composition according to any one of <1> to <20>, which is 38 or more and 1.5 or less.
<24> The mass ratio of the plasticizer to the triaryl phosphate (plasticizer / triaryl phosphate) is preferably 0.35 or more and 3.0 or less, more preferably 0.40 or more and 0.80 or less, and still more preferably 0.8. The polylactic acid resin composition according to any one of <1> to <20>, which is 50 or more and 0.75 or less, and more preferably 0.55 or more and 0.75 or less.
<25> As the metal hydroxide to be subjected to the surface treatment, aluminum hydroxide, magnesium hydroxide and calcium hydroxide are preferable, aluminum hydroxide and magnesium hydroxide are more preferable, and aluminum hydroxide is more preferable. The polylactic acid resin composition according to any one of 1> to <24>.
<26> As the surface-treated metal hydroxide, aluminum hydroxide and magnesium hydroxide treated with a silane coupling agent are preferable, and aluminum hydroxide treated with a silane coupling agent is more preferable, <1 >-<25> The polylactic acid resin composition according to any one of the above.
<27> As the silane coupling agent, coupling agents such as isocyanate silane, amino silane, mercapto silane, epoxy silane, vinyl silane, methacryl silane, and epoxy silane are preferable, and coupling agents for isocyanate silane, amino silane, mercapto silane, and epoxy silane. Is more preferable, isocyanate silane and aminosilane are still more preferable, and isocyanate silane is still more preferable, The polylactic acid resin composition as described in said <26>.
<28> The metal hydroxide subjected to the surface treatment with the silane coupling agent has a mass ratio of the silane coupling agent to the metal hydroxide (silane coupling agent / metal hydroxide) of 0.1 / 99. The polylactic acid according to <26> or <27>, preferably 9 to 5/95, more preferably 0.3 / 99.7 to 3/97, and still more preferably 0.5 / 99.5 to 2/98. Resin composition.
<29> The surface-treated metal hydroxide is preferably 0.5 μm or more, more preferably 1 μm or more, further preferably 2 μm or more, preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 4 μm or less. The polylactic acid resin composition according to any one of <1> to <28>, wherein
<30> The difference in average particle diameter is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 3 μm or less, more preferably 2 μm or less, in combination with metal hydroxides having different average particle diameters. The polylactic acid resin composition according to any one of <1> to <29>.
<31> The content of the surface-treated metal hydroxide with respect to 100 parts by mass of the polylactic acid resin is preferably 25 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 35 parts by mass or more, and still more preferably. The polylactic acid resin composition according to any one of <1> to <30>, which is 38 parts by mass or more, preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and still more preferably 50 parts by mass or less. .
<32> The content of the surface-treated metal hydroxide with respect to 100 parts by mass of the polylactic acid resin is preferably 10 parts by mass to 80 parts by mass, more preferably 25 parts by mass to 60 parts by mass, and still more preferably 30 parts. The polylactic acid resin composition according to any one of <1> to <31>, wherein the composition is not less than 50 parts by mass and more preferably not less than 38 parts by mass and not more than 50 parts by mass.
<33> Melamine compounds include melamine phosphate, dimelamine phosphate, melamine polyphosphate, melamine pyrophosphate, melamine phthalate, melamine phthalimide, melamine borate, melamine ammonium phosphate, melamine ammonium polyphosphate, melamine cyanurate, melamine Isocyanurate is preferred, melamine polyphosphate, melamine cyanurate, and melamine isocyanurate are more preferred, melamine cyanurate and / or melamine isocyanurate are more preferred, polylactic acid resin according to any one of <1> to <32> Composition.
<34> The content of the melamine compound in the polylactic acid resin composition is preferably 20 parts by mass or more, more preferably 35 parts by mass or more, preferably 90 parts by mass or less, relative to 100 parts by mass of the polylactic acid resin. The polylactic acid resin composition according to any one of <1> to <33>, more preferably 80 parts by mass or less, still more preferably 60 parts by mass or less, and still more preferably 55 parts by mass or less.
<35> The content of the melamine compound in the polylactic acid resin composition is preferably 20 parts by mass or more and 100 parts by mass or less, more preferably 30 parts by mass or more and 90 parts by mass or less, with respect to 100 parts by mass of the polylactic acid resin. The polylactic acid resin composition according to any one of <1> to <34>, preferably 30 parts by mass or more and 60 parts by mass or less, and more preferably 30 parts by mass or more and 45 parts by mass or less.
<36> The total content of the melamine compound and the surface-treated metal hydroxide is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, and still more preferably 60 parts by mass with respect to 100 parts by mass of the polylactic acid resin. Part or more, more preferably 70 parts by weight or more, more preferably 75 parts by weight or more, preferably 140 parts by weight or less, more preferably 130 parts by weight or less, still more preferably 120 parts by weight or less, still more preferably 110 parts by weight. The polylactic acid resin composition according to any one of <1> to <35>, further preferably 105 parts by mass or less, and still more preferably 90 parts by mass or less.
<37> The mass ratio of the surface-treated metal hydroxide to the melamine compound (surface-treated metal hydroxide / melamine compound) is preferably 0.12 or more, more preferably 0.15 or more, and still more preferably. 0.50 or more, more preferably 0.80 or more, preferably 8.0 or less, more preferably 6.0 or less, still more preferably 3.0 or less, still more preferably 2.0 or less, and even more preferably. The polylactic acid resin composition according to any one of <1> to <36>, wherein is 1.5 or less.
<38> The polylactic acid resin composition according to any one of <1> to <37>, wherein the polylactic acid resin is a polylactic acid resin having an optical purity of preferably 90% or more, more preferably 95% or more.
<39> The content of the polylactic acid resin in the polylactic acid resin composition is preferably 30% by mass or more, more preferably 40% by mass or more, still more preferably 43% by mass or more, and preferably 80% by mass or less. The polylactic acid resin composition according to any one of <1> to <38>, more preferably 70% by mass or less, and still more preferably 60% by mass or less.
<40> The polylactic acid resin composition according to any one of <1> to <39>, further comprising an organic crystal nucleating agent.
<41> As the organic crystal nucleating agent, it is preferable to use one or more organic crystal nucleating agents selected from the group consisting of the following (c) to (d), Lactic acid resin composition.
(C) 1 selected from the group consisting of metal salts of sulfoaromatic carboxylic acid esters, metal salts of phosphoric acid esters, metal salts of phenylphosphonic acid, metal salts of rosin acids, aromatic carboxylic acid amides, and rosin acid amides Species or two or more organic compounds [referred to as organic crystal nucleating agent (c)]
(D) One or more organic compounds selected from the group consisting of a compound having a hydroxyl group and an amide group in the molecule and a hydroxy fatty acid ester [referred to as organic crystal nucleating agent (d)]
<42> The organic crystal nucleating agent (c) is preferably a phenylphosphonic acid metal salt having an optionally substituted phenyl group and a phosphonic group (—PO (OH) ₂ ), and unsubstituted phenylphosphonic acid. More preferred are metal salts of acid, methylphenylphosphonic acid, ethylphenylphosphonic acid, propylphenylphosphonic acid, butylphenylphosphonic acid, dimethoxycarbonylphenylphosphonic acid, diethoxycarbonylphenylphosphonic acid, and metal salts of unsubstituted phenylphosphonic acid Is more preferable, The polylactic acid resin composition as described in said <41>.
<43> The metal salt is preferably lithium, sodium, magnesium, aluminum, potassium, calcium, barium, copper, zinc, iron, cobalt, nickel, and more preferably a zinc salt, and the polylactic acid resin according to the above <42> Composition.
<44> The compound having a hydroxyl group and an amide group in the molecule of the organic crystal nucleating agent (d) is preferably an aliphatic amide having a hydroxyl group, having two or more hydroxyl groups in the molecule and having two or more amide groups. More preferably aliphatic amides such as hydroxy fatty acid monoamides such as 12-hydroxystearic monoethanolamide, methylene bis 12-hydroxystearic amide, ethylene bis 12-hydroxystearic amide, hexamethylene bis 12-hydroxystearic amide The polylactic acid resin composition according to <41>, wherein hydroxy fatty acid bisamide and the like are more preferable.
<45> The organic crystal nucleating agent (c) and (d) are preferably used in combination, more preferably a compound having a hydroxyl group and an amide group in the molecule and a metal salt of phenylphosphonic acid, and a hydroxy fatty acid. It is more preferable to use a metal salt of bisamide and unsubstituted phenylphosphonic acid in combination, and it is more preferable to use ethylenebis12-hydroxystearic acid amide and a zinc salt of unsubstituted phenylphosphonic acid in combination. <44> The polylactic acid resin composition according to any one of the above.
<46> The mass ratio of hydroxy fatty acid bisamide and metal salt of phenylphosphonic acid (hydroxy fatty acid bisamide / metal salt of phenylphosphonic acid) is preferably 0.2 or more, more preferably 0.3 or more, and still more preferably 0.00. The polylactic acid resin composition according to <45>, which is 5 or more, preferably 6 or less, more preferably 4 or less, and still more preferably 2 or less.
<47> The content of the organic crystal nucleating agent is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and still more preferably 0.5 parts by mass or more with respect to 100 parts by mass of the polylactic acid resin. The polylactic acid resin composition according to any one of <40> to <46>, preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and still more preferably 2.5 parts by mass or less.
<48> The polylactic acid resin composition according to any one of <1> to <47>, further comprising a hydrolysis inhibitor.
<49> The content of the hydrolysis inhibitor is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and further preferably 1 part by mass or more with respect to 100 parts by mass of the polylactic acid resin. The polylactic acid resin composition according to <48>, preferably 7 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 3 parts by mass or less.
<50> containing a polylactic acid resin, a triaryl phosphate containing at least one alkylaryl group having an alkyl group having 1 to 3 carbon atoms, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, The total mass of the triaryl phosphate and the plasticizer is 16 to 30 parts by mass with respect to 100 parts by mass of the lactic acid resin, the content of the surface-treated metal hydroxide is 10 to 100 parts by mass, and the content of the melamine compound The polylactic acid resin composition according to any one of the above <1> to <49>, wherein the polylactic acid resin composition is prepared by melting and kneading raw materials containing various components as necessary.
<51> The melt kneading temperature is preferably 160 ° C. or higher, more preferably 165 ° C. or higher, further preferably 170 ° C. or higher, and preferably 230 ° C. or lower, more preferably 220 ° C. or lower, still more preferably 215 ° C. or lower. The polylactic acid resin composition according to <50>, wherein
<52> Obtained by melt-kneading the polylactic acid resin composition according to any one of <1> to <51>, filling into a mold having a desired shape using an injection molding machine, and injection molding. Molded body.
<53> Injection molding is performed using an injection molding machine in which the set temperature of the cylinder is preferably 180 ° C. or higher, preferably 220 ° C. or lower, more preferably 210 ° C. or lower, and even more preferably 200 ° C. or lower. The molded product according to <52>.
<54> The mold temperature is preferably 110 ° C. or lower, more preferably 100 ° C. or lower, further preferably 90 ° C. or lower, further preferably 80 ° C. or lower, more preferably 30 ° C. or higher, and more preferably 40 ° C. or higher. The molded article according to the above <52> or <53>, which is more preferably 60 ° C. or higher.
<55> A method for producing an injection-molded product of the polylactic acid resin composition according to any one of <52> to <54>, comprising the following steps.
Step (1): A polylactic acid resin composition comprising a polylactic acid resin and a triaryl phosphate, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, wherein the triaryl phosphate is carbon. 1 or more alkylaryl groups having 1 to 3 alkyl groups are included, and the total amount of the triaryl phosphate and the plasticizer is 16 to 30 parts by mass with respect to 100 parts by mass of the polylactic acid resin. Melting and kneading the polylactic acid resin composition with a metal hydroxide content of 10 to 100 parts by mass and a melamine compound content of 10 to 100 parts by mass Step (2) for preparing a kneaded product: a step of injection-molding a melt-kneaded product of the polylactic acid resin composition obtained in step (1) into a mold.

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to the following examples. The parts in the examples are parts by mass unless otherwise specified. “Normal pressure” indicates 101.3 kPa, and “normal temperature” indicates 25 ° C.

[Average particle diameter of surface-treated metal hydroxide]
The average particle size of the surface-treated metal hydroxide means the volume median particle size (D ₅₀ ), and a laser diffraction / scattering type particle size distribution measuring device “Mastersizer 2000” (manufactured by Malvern) is used. In addition, Isopar G (manufactured by ExxonMobil) is added to the measurement cell, and the particle refractive index is 1.58 (imaginary part 0.1) and the dispersion medium refractive index is 1.42 at a concentration at which the scattering intensity is 5 to 15%. Under conditions, the volume-median particle size (D ₅₀ ) is measured.

[Acid value, hydroxyl value, and saponification value of plasticizer]
Acid value: Analysis is performed according to the test method of JIS K 0070, except that toluene / ethanol = 2/1 (volume ratio) is used as a titration solvent.
Hydroxyl value: Analysis is performed according to the test method of JIS K 0070, except that acetic anhydride / pyridine = 1/4 (volume ratio) is used as the acetylating reagent and the addition amount is 3 mL.
Saponification value: Analysis is performed according to the test method of JIS K 0070, except that the temperature of the water bath is 95 ° C. and the heating temperature is 1 hour.

[Molecular weight of plasticizer compound group (A)]
The molecular weight of the plasticizer compound group (A) means a weight average molecular weight and is calculated from the saponification value by the following formula.
Average molecular weight = 56108 × (number of ester groups in one molecule) / saponification value

[Molecular weight, terminal alkyl esterification rate, and ether group value of plasticizer compound group (B)]
Molecular weight: In this specification, the molecular weight of the plasticizer compound group (B) means the number average molecular weight, and is calculated from the acid value, hydroxyl value, and saponification value according to the following formula.
Average molecular weight M = (M ₁ + M ₂ −M ₃ × 2) × n + M ₁ − (M ₃ −17.01) × 2 + (M ₃ −17.01) × p + (M ₂ −17.01) × q + 1. 01 × (2-pq)
q = hydroxyl value × M ÷ 56110
2-pq = acid value × M ÷ 56110
Average degree of polymerization n = saponification number × M ÷ (2 × 56110) −1
Terminal alkyl esterification rate: The molecular terminal alkyl esterification rate (terminal alkyl esterification rate) can be calculated from the following formula. The larger the value of the molecular terminal alkyl esterification rate, the free carboxyl group or hydroxyl group There are few, and it shows that the molecular terminal is fully alkylesterified.
Terminal alkyl esterification rate (%) = (p ÷ 2) × 100
Where M ₁ : molecular weight of diester of dicarboxylic acid used as raw material and monohydric alcohol used as raw material M ₂ : molecular weight of dihydric alcohol used as raw material M ₃ : molecular weight of monohydric alcohol used as raw material p: in one molecule Number of terminal alkyl ester groups q: Number of terminal hydroxyl groups in one molecule Ether group number: The ether group number, which is the number of millimoles (mmol) of ether groups in 1 g of carboxylic acid ester, is calculated from the following formula.
Ether group value (mmol / g) = (m−1) × n × 1000 ÷ M
Where m: average number of repeating oxyalkylene groups (m-1 represents the number of ether groups in one molecule of dihydric alcohol)
In addition, when using multiple types of dicarboxylic acid, monohydric alcohol, and dihydric alcohol, molecular weight uses the molecular weight of a number average value.

<Production Example 1 of Plasticizer> (Diester of Succinic Acid and Triethylene Glycol Monomethyl Ether)
A 3 L flask equipped with a stirrer, thermometer and dehydration tube was charged with 500 g of succinic anhydride, 2463 g of triethylene glycol monomethyl ether, and 9.5 g of paratoluenesulfonic acid monohydrate, and nitrogen (500 mL / min) was added to the space. The reaction was carried out at 110 ° C. for 15 hours under reduced pressure (4 to 10.7 kPa) while blowing. The acid value of the reaction solution was 1.6 (mgKOH / g). After adding 27 g of adsorbent KYOWARD 500SH (manufactured by Kyowa Chemical Industry Co., Ltd.) to the reaction solution, stirring and filtering at 80 ° C. and 2.7 kPa for 45 minutes, and then triethylene at a liquid temperature of 115 to 200 ° C. and a pressure of 0.03 kPa. After distilling off the glycol monomethyl ether and cooling to 80 ° C., the residual liquid was filtered under reduced pressure to obtain a diester [(MeEO ₃ ) ₂ SA] of succinic acid and triethylene glycol monomethyl ether as a filtrate. The obtained diester had a weight average molecular weight of 410, a viscosity (23 ° C.) of 27 mPa · s, an acid value of 0.2 mgKOH / g, a saponification value of 274 mgKOH / g, a hydroxyl value of 1 mgKOH / g or less, and a hue APHA200.

<Plasticizer Production Example 2> (Diester of succinic acid, 1,3-propanediol and methanol, raw material (molar ratio): dimethyl succinate / 1,3-propanediol (1.5 / 1))
In a four-necked flask (with a stirrer, thermometer, dropping funnel, distillation tube, nitrogen blowing tube), 521 g (6.84 mol) of 1,3-propanediol and 5.9 g of a methanol solution containing 28% by weight sodium methoxide as a catalyst (Sodium methoxide 0.031 mol) was added, and methanol was distilled off with stirring at normal pressure and 120 ° C. for 0.5 hour. Thereafter, 1500 g (10.26 mol) of dimethyl succinate (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 1 hour, and methanol produced by the reaction was distilled off at normal pressure and 120 ° C. Next, the mixture was cooled to 60 ° C., 5.6 g of 28 mass% sodium methoxide-containing methanol solution (0.029 mol of sodium methoxide) was added, the temperature was raised to 120 ° C. over 2 hours, and then the pressure was applied over 1 hour. The methanol was gradually distilled off from normal pressure to 3.7 kPa. Then, after cooling to 80 ° C., 18 g of KYOWARD 600S (manufactured by Kyowa Chemical Industry Co., Ltd.) was added and stirred at a pressure of 4.0 kPa and 80 ° C. for 1 hour, followed by filtration under reduced pressure. The filtrate was raised at a pressure of 0.1 kPa and the temperature was raised from 85 ° C. to 194 ° C. over 2.5 hours to distill off the remaining dimethyl succinate to obtain a room temperature yellow liquid. In addition, the usage-amount of the catalyst was 0.58 mol with respect to 100 mol of dicarboxylic acid ester. (R ¹ in formula (I): methyl, R ² : ethylene, R ³ : 1,3-propylene, m = 1, n = 4.4; acid value 0.64 mgKOH / g; hydroxyl value 1.3 mgKOH / g Saponification number 719.5 mg KOH / g; number average molecular weight 850; terminal alkyl esterification rate 98.5%; ether group number 0 mmol / g.)

<Production Example 3 of Plasticizer> (Tris (ethoxyethoxyethyl) phosphate)
To a 1 liter four-necked flask, 600 g (4.47 mol) of diethylene glycol monoethyl ether was added and stirred under reduced pressure (20 kPa) while blowing dry nitrogen gas at a flow rate of 50 mL per minute. Next, 114 g (0.745 mol) of phosphorus oxychloride was slowly added dropwise while maintaining the reaction system at room temperature (15 ° C.), and then aged at 40-60 ° C. for 5 hours. Thereafter, 149 g of a 16% by mass aqueous sodium hydroxide solution was added for neutralization, and excess unreacted diethylene glycol monoethyl ether was distilled off under reduced pressure at a temperature of 70 to 120 ° C., and further contacted with steam to obtain crude phosphoric acid. 367 g of triester was obtained. Further, 300 g of a 16% by mass aqueous sodium chloride solution was added to the crude phosphoric acid triester for washing. Thereafter, the separated lower layer was drained, and the remaining upper layer was dehydrated under reduced pressure at 75 ° C., and the solid content was further removed by filtration to obtain 266 g of the desired tris (ethoxyethoxyethyl) phosphate (yield) 80%). This tris (ethoxyethoxyethyl) phosphate is a colorless and transparent uniform liquid. As a result of the chloro ion analysis, the chloro ion content was 10 mg / kg or less.

<Aluminum hydroxide (A): Production example 1 of surface-treated aluminum hydroxide>
5 g of an isocyanate-based silane coupling agent (3-isocyanatepropyltriethoxysilane, Shin-Etsu Chemical Co., KBE-9007) is dissolved in 200 g of an organic solvent (acetone), and aluminum hydroxide (Nippon Light Metal Co., Ltd., BE033, average) 500 g of particle size 2 μm, content of alkali metal substance 0.01% by mass), stirred with a mixer, then the organic solvent was removed and dried to obtain a mass ratio (silane coupling agent / aluminum hydroxide) An isocyanate-based silane coupling agent-treated aluminum hydroxide (aluminum hydroxide (A)) treated at a ratio of 1/99 was obtained.

<Aluminum hydroxide (B): Production Example 2 of surface-treated aluminum hydroxide>
In the same manner as in Production Example 1 for surface-treated aluminum hydroxide, an isocyanate-based silane coupling agent (KBE-9007), aluminum hydroxide (manufactured by Nippon Light Metal Co., Ltd., B703, average particle size 3.5 μm, alkali metal-based material) An isocyanate-based silane coupling agent-treated aluminum hydroxide (aluminum hydroxide (B)) in which a mass ratio (silane coupling agent / aluminum hydroxide) was treated at a ratio of 1/99 by mass ratio (0.3 mass%) was obtained. It was.

<Aluminum hydroxide (C): Production example 3 of surface-treated aluminum hydroxide>
In the same manner as in Production Example 1 for surface-treated aluminum hydroxide, an amino-based silane coupling agent (3-aminopropyltriethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., KBE-903) and aluminum hydroxide (B703) in a mass ratio ( An amino silane coupling agent-treated aluminum hydroxide (aluminum hydroxide (C)) treated with a silane coupling agent / aluminum hydroxide in a ratio of 1/99 was obtained.

Examples 1 to 18 and Comparative Examples 1 to 11
[Step (1)]
Polylactic acid resin compositions obtained by melt-kneading the composition materials shown in Tables 1 to 3 at 190 ° C. using a directional meshing twin-screw extruder (Toshiki Machine Co., Ltd., TEM-41SS) and cutting the strands. Pellets were obtained. In addition, the obtained pellet was dehumidified and dried at 110 ° C. for 2 hours, and the water content was adjusted to 500 ppm or less.

[Step (2)]
The pellets obtained in step (1) were injection-molded using an injection molding machine (manufactured by Nippon Steel Works, J75E-D) with a cylinder temperature of 200 ° C., with a mold temperature of 80 ° C. and a molding time of 60 seconds. Test pieces [square columnar test pieces (125 mm × 12 mm × 6 mm), (125 mm × 12 mm × 1.6 mm) and flat plate test pieces (100 mm × 100 mm × 2 mm)] were obtained.

The raw materials in Tables 1 to 3 are as follows.
[Polylactic acid resin]
NW4032D: Nature Works 4032D (manufactured by Nature Works)
[Organic crystal nucleating agent]
SLIPAX H: Ethylene bis 12-hydroxystearic amide (Nippon Kasei Co., Ltd.)
PPA-Zn: unsubstituted phenylphosphonic acid zinc salt (manufactured by Nissan Chemical Industries)
LAK-301: dimethyl potassium 5-sulfoisophthalate (manufactured by Takemoto Yushi Co., Ltd.)
NJester TF-1: 1,3,5-benzenetricarboxylic acid tricyclohexylamide (manufactured by Shin Nippon Chemical Co., Ltd.)
[Plasticizer]
(MeEO ₃ ) ₂ SA: Diester compound of succinic acid and triethylene glycol monomethyl ether produced in Production Example 1 of plasticizer DAIFACTY-101: Adipic acid and diethylene glycol monomethyl ether / benzyl alcohol = 1/1 mixture Diester (made by Daihachi Chemical Industry Co., Ltd.)
MeSA-1,3PD: Diester of succinic acid, 1,3-propanediol and methanol produced in Production Example 2 of plasticizer TEP-2: Tris (ethoxyethoxyethyl) phosphate produced in Production Example 3 of plasticizer [Triaryl phosphate (triaryl phosphate) containing at least one alkylaryl group having an alkyl group having 1 to 3 carbon atoms]
Leophos 65: Triaryl phosphate isopropylate (Ajinomoto Fine Techno Co., Ltd.)
CDP: Cresyl diphenyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd.)
[Metal hydroxide]
Aluminum hydroxide (A): Aluminum hydroxide treated with isocyanate-based silane coupling agent produced in Production Example 1 of surface-treated aluminum hydroxide, average particle size 2 μm, granular aluminum hydroxide (B): surface-treated aluminum hydroxide The isocyanate-based silane coupling agent-treated aluminum hydroxide produced in Production Example 2 of the above, average particle size 3.5 μm, powdered aluminum hydroxide (C): amino-based produced in Production Example 3 of surface-treated aluminum hydroxide Silane coupling agent-treated aluminum hydroxide, average particle size 3.5 μm, granular BE033: Aluminum hydroxide (manufactured by Nippon Light Metal Co., Ltd.), average particle size 2 μm, granular [melamine compound]
MC-2010N: Melamine cyanurate (manufactured by Sakai Chemical Co., Ltd.)
[Other flame retardants]
TPP: Triphenyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd.)
PX-200: condensed phosphate ester (Daihachi Chemical Industry Co., Ltd.)
〔Antioxidant〕
IRGAFOS 168: Tris (2,4-di-t-butylphenyl) phosphite (BASF)

The properties of the obtained polylactic acid resin composition and the molded product thereof were evaluated according to the methods of Test Examples 1 to 5 below. The results are shown in Tables 1 to 3.

Test Example 1 <Evaluation of flame retardancy>
Using a test piece (prism test piece (125 mm × 12 mm × 1.6 mm)), a flame of a gas burner for 10 seconds at the lower end of a vertically held sample based on the safety standard UL94 vertical combustion test procedure of Underwriters Laboratories. A flame test was conducted on five samples in which a flame was contacted, and then combustion was stopped within 30 seconds, and then an indirect flame was further applied for 10 seconds. Based on the criteria of the UL94 vertical combustion test (UL94V), V-2, V-1, and V-0 were judged. The judgment criteria are shown below. V-1 or more is preferable, and V-0 is more preferable. In addition, about the thing which does not correspond to these criteria, a flame retardance was set to Not.

[Flame retardancy criteria]
・ V-0
After any flame contact, no sample continues to burn for more than 10 seconds.
The total combustion time for 10 flames on 5 samples does not exceed 50 seconds.
There is no sample that burns to the position of the clamping clamp.
There is no sample that ignites absorbent cotton placed under the sample and drops burning particles.
After the second flame contact, there is no sample that continues red heat for 30 seconds or more.
・ V-1
No sample continues to burn for more than 30 seconds after any flame contact.
The total burn time for 10 flames on 5 samples does not exceed 250 seconds.
There is no sample that burns to the position of the clamping clamp.
There is no sample that ignites absorbent cotton placed under the sample and drops burning particles.
After the second flame contact, there is no sample that continues red heat for 60 seconds or more.
・ V-2
No sample continues to burn for more than 30 seconds after any flame contact.
The total burn time for 10 flames on 5 samples does not exceed 250 seconds.
There is no sample that burns to the position of the clamping clamp.
Falling of burning particles that ignite absorbent cotton placed under the sample is allowed.
After the second flame contact, there is no sample that continues red heat for 60 seconds or more.

Test Example 2 <Evaluation of fluidity>
The obtained polylactic acid resin composition pellets were injection molded using an injection molding machine (Japan Steel Works, J75E-D) with a cylinder temperature of 200 ° C., and a mold temperature of 80 ° C. and an injection pressure of 942 kgf / A molded body for evaluation of a 3 mm-thick spiral flow was injection-molded by setting cm ² and an injection speed of 68 cm ³ / sec, respectively. L / D was determined by setting the length of the molded body to L (mm) and the thickness to D (mm), and used as an index of fluidity. A resin composition having a larger L / D has better fluidity, and L / D is preferably 145 or more, and more preferably 160 or more.

Test Example 3 <Evaluation of Impact Resistance>
Using a falling ball impact tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) and a flat plate test piece (100 mm x 100 mm x 2 mm), the height (cm) at which the 1 kg iron ball was dropped onto the flat plate test piece was dropped. It was measured as the strength height. The falling ball impact test was repeated 10 times, and the number average value of falling ball impact strength height (cm) was determined. The higher the falling ball impact strength height (cm), the better the impact resistance. 60 cm or more is preferable, 75 cm or more is more preferable, and 90 cm or more is more preferable.

Test Example 4 <Evaluation of bleed resistance>
Using a test piece (125 mm × 12 mm × 1.6 mm), after standing for 1 week in a temperature-controlled room at a temperature of 60 ° C./humidity of 85%, the presence or absence of additive bleed in the surface appearance is visually observed, Bleed resistance was evaluated according to the following criteria. The smaller the bleed, the better the bleed resistance, preferably B or more, and more preferably A.

[Criteria for bleed resistance]
A: It cannot be visually confirmed, and no liquid or powder adheres even if it is traced with a finger.
B: Although it cannot be confirmed visually, there is a slight liquid or powder adhesion to the finger when traced with the finger.
C: Liquid droplets or powder is visually confirmed on the surface of the molded body, and liquid or powder adheres to the finger when traced with the finger.

Test Example 5 <Durability Evaluation>
The test piece (125 mm × 12 mm × 6 mm)] was stored in a temperature-controlled room at a temperature of 60 ° C./humidity of 85% for 400 hours, and then allowed to stand overnight at room temperature. Then, based on ASTM D256, an Izod impact tester (Yasuda Seiki) (Manufactured by Seisakusho Co., Ltd.), an impact test was conducted at n = 10 to measure Izod impact strength (J / m), and a number average value thereof was calculated. About the obtained result, retention [%] was computed from the initial physical-property value (Izod impact strength) before implementation of a durability test. The calculation method is shown below. The durability (retention rate [%]) is preferably 70% or more, more preferably 75% or more, and still more preferably 80% or more.
Retention rate [%] = (impact test result after durability test) / (impact test result before durability test) × 100

From the results in Tables 1 to 3, the polylactic acid resin composition of the present invention in which a polylactic acid resin, a plasticizer, a specific triaryl phosphate, a melamine compound, and a surface-treated metal hydroxide were blended in a specific amount (implementation) Examples 1 to 18) show fluidity of 155 (L / D) or more, flame retardancy is V-1 or more, falling ball impact strength height is 60 cm or more, and durability is 60% or more. Excellent bleed resistance.

On the other hand, when the non-surface-treated metal hydroxide of Comparative Example 1 is used, the impact resistance is low, and in Comparative Example 2 where no specific triaryl phosphate is used, fluidity, flame retardancy, and In Comparative Example 3 where the impact resistance was low and no plasticizer was used, the fluidity was low.

Further, the triphenyl phosphate having no alkyl group of Comparative Example 4 has low impact resistance, and the condensed phosphate of Comparative Example 5 has low fluidity and impact resistance, and bleed resistance was not good. In Comparative Example 6 in which the amount of the melamine compound is too large, the fluidity is low, and in Comparative Example 7 in which the amount of the metal hydroxide is too large, the fluidity, impact resistance, and durability are decreased. In Comparative Example 8 in which the total amount of the plasticizer and triaryl phosphate was too small, the fluidity was low, and in Comparative Example 9 in which the total amount was too large, the bleeding property was lowered. In Comparative Example 10 in which no melamine compound is used, the durability is low, and in Comparative Example 11 in which no metal hydroxide is used, the flame retardancy is low.

The polylactic acid resin composition of the present invention can be suitably used as home appliance parts such as a casing of an information home appliance.

Claims

A polylactic acid resin composition comprising a polylactic acid resin, a triaryl phosphate, a plasticizer, a melamine compound, and a surface-treated metal hydroxide, wherein the triaryl phosphate is an alkyl group having 1 to 3 carbon atoms The surface-treated metal hydroxide includes one or more alkylaryl groups having a total mass of 16 to 30 parts by mass with respect to 100 parts by mass of the polylactic acid resin. The polylactic acid resin is 10 to 100 parts by mass with respect to 100 parts by mass of the polylactic acid resin, and the content of the melamine compound is 10 to 100 parts by mass with respect to 100 parts by mass of the polylactic acid resin. Composition.
The polylactic acid resin composition according to claim 1, wherein the mass ratio of the plasticizer to the triaryl phosphate (plasticizer / triaryl phosphate) is 0.30 to 3.5.
The polylactic acid resin composition according to claim 1 or 2, wherein the total content of the surface-treated metal hydroxide and the melamine compound is 40 to 140 parts by mass with respect to 100 parts by mass of the polylactic acid resin.
The content of the triaryl phosphate containing one or more alkylaryl groups having an alkyl group having 1 to 3 carbon atoms is 5 to 21 parts by mass with respect to 100 parts by mass of the polylactic acid resin. A polylactic acid resin composition according to claim 1.
The triaryl phosphate containing one or more alkylaryl groups having an alkyl group having 1 to 3 carbon atoms includes at least one selected from the group consisting of isopropylphenyl diphenyl phosphate and cresyl diphenyl phosphate. 5. The polylactic acid resin composition according to any one of 4 to 4.
The polylactic acid resin composition according to any one of claims 1 to 5, wherein the content of the plasticizer is 4 to 21 parts by mass with respect to 100 parts by mass of the polylactic acid resin.
The polylactic acid resin composition according to any one of claims 1 to 6, wherein the plasticizer comprises an ester compound having a (poly) oxyalkylene group or an alkylene group having 2 to 6 carbon atoms.
The polylactic acid resin composition according to any one of claims 1 to 7, wherein the metal hydroxide contains at least one selected from the group consisting of aluminum hydroxide and magnesium hydroxide.
The polylactic acid resin composition according to any one of claims 1 to 8, wherein the surface-treated metal hydroxide comprises a metal hydroxide treated with a silane coupling agent.
The polylactic acid resin composition according to claim 9, wherein the silane coupling agent comprises one or more selected from the group consisting of isocyanate silane and aminosilane.
11. The polylactic acid resin composition according to claim 1, wherein the average particle diameter of the surface-treated metal hydroxide is 0.5 μm or more and 10 μm or less.
The polylactic acid resin composition according to any one of claims 1 to 11, wherein metal hydroxides having different average particle diameters having a difference in average particle diameter of 0.5 to 3 µm are used in combination.
The polylactic acid resin composition according to any one of claims 1 to 12, wherein the melamine compound contains at least one selected from the group consisting of melamine cyanurate and melamine isocyanurate.
The polylactic acid resin composition according to any one of claims 1 to 13, further comprising an organic crystal nucleating agent.
A molded product obtained by melt-kneading the composition according to any one of claims 1 to 14 and then injection molding.
The method for producing an injection-molded body of the polylactic acid resin composition according to any one of claims 1 to 14, comprising the following steps.
Step (1): A polylactic acid resin composition comprising a polylactic acid resin and a triaryl phosphate, a plasticizer, and a surface-treated metal hydroxide, wherein the triaryl phosphate has a carbon number. One or more alkylaryl groups having 1 to 3 alkyl groups, and the total mass of the triaryl phosphate and the plasticizer is 16 to 30 parts by mass with respect to 100 parts by mass of the polylactic acid resin. The mass ratio of plasticizer to reel phosphate (plasticizer / triaryl phosphate) is 0.30 to 3.5, and the surface-treated metal hydroxide is 40 to 120 mass with respect to 100 mass parts of polylactic acid resin. A step of preparing a melt-kneaded product of the polylactic acid resin composition by melt-kneading the polylactic acid resin composition as a part
Step (2): A step of injection molding the melt-kneaded product of the polylactic acid resin composition obtained in Step (1) into a mold.