JP6075000B2 - Flame retardant polylactic acid-based thermoplastic resin composition and molded article thereof - Google Patents

Description

  In the present invention, even when a polylactic acid resin is contained in a resin composition in an amount of 25% by weight or more, mechanical strength such as impact strength sufficient for practical use in thin-walled molded articles, heat resistance, flame retardancy, molding The present invention relates to a flame retardant polylactic acid-based thermoplastic resin composition capable of providing a molded product having the properties and appearance, and a molded product formed by molding this flame-retardant polylactic acid-based thermoplastic resin composition.

  In recent years, the problems faced by modern society and modern industry, such as the depletion of petroleum resources and global warming, have been highlighted, and it has been emphasized how to build an environmentally friendly system. Attention has been focused on the use of plant-derived resin as a measure to minimize the use of petroleum resources and to prevent carbon dioxide from being discharged into the atmosphere as much as possible. Since plants absorb carbon dioxide and release oxygen, it is thought that there is no increase or decrease in carbon dioxide in the atmosphere, and plant-derived resins produced using this plant as a raw material can stop global warming. It is also important to use only a small amount of petroleum resources.

  Plant-derived resins have been initially studied for use as biodegradable resins and have been commercialized in relation to films, sheets, fibers, etc., but are not sufficiently widespread in many fields. The major factors include drawbacks such as low impact resistance and heat resistance compared to conventional petroleum-derived resins.

  A typical example of such plant-derived resins is polylactic acid resin (PLA). In recent years, many studies have been conducted on polylactic acid resins, and the physical properties that are inferior to conventional petroleum-derived resins are not biodegradable, but are based on the fact that they are derived from plants. It is proceeding in the direction of solution.

  However, even if such alloying is attempted, it has not yet been possible to cover all fields of petroleum-derived resins. One of the major factors is the flame retardant field. Although high flame retardancy is required in the electric / electronic field, it is considered difficult to improve the flame retardancy because the polylactic acid resin itself is easy to burn. Therefore, it has been desired to develop a polylactic acid resin that can be used in the electric and electronic fields and has excellent properties such as flame retardancy, mechanical properties, heat resistance, and the appearance of a molded product.

  In general, various studies have been made to improve the flame retardancy of resins, and similar efforts have been made when polylactic acid resins are used.

  For example, Japanese Patent Laid-Open No. 2003-192925 discloses a method of adding a phosphorus-based flame retardant, and Japanese Patent Laid-Open No. 2004-256809 discloses a method of adding a flame-retardant PET. However, the flame retardancy is not sufficient for use in the electric / electronic field.

  Patent Document 3 “Japanese Unexamined Patent Application Publication No. 2007-146087” discloses a flame-retardant polylactic acid-based thermoplastic resin composition containing a polycarbonate resin, a phosphorus-based flame retardant, or the like as a further improvement of the above-described Patent Documents 1 and 2. Although it is shown, all the conventional polylactic acid-based resin compositions including Patent Document 3 can achieve some degree of flame retardancy, but flame retardancy, impact resistance, and heat resistance in thin-walled molded products are shown. In terms of the above, it cannot be said that it is functionally sufficient as compared with the petroleum-derived resin composition that has been used in the electronic / electric field.

  In addition, considering the prevention of global warming and the importance of reducing the consumption of fossil resources, considering the adaptation to the biomass plastic identification and labeling system operated by the Japan Bioplastics Association and environmental considerations aimed at obtaining the biomass plastic mark. The polylactic acid resin content in the composition needs to be 25% by weight or more. However, when a flammable polylactic acid resin is blended in the composition in an amount of 25% by weight or more, it is difficult to improve the flame retardancy. Conventionally, various studies have been made on this point, but sufficient results for use in the electric / electronic field have not been obtained.

  The polyester flame retardant (E) used in the present invention is described as a flame retardant polyester in Patent Document 4 “International Publication WO 2006/057228 Pamphlet”. Although there is a description that polyester can be used as a masterbatch by blending with other resins, there is no description about specific blending examples or resins to be blended.

JP 2003-192925 A JP 2004-256809 A JP 2007-146087 A International Publication WO2006 / 057228 Pamphlet

  The present invention solves the above-described problems in the prior art, and even when the polylactic acid resin is contained in an amount of 25% by weight or more, mechanical strength such as impact strength that is practically sufficient for a thin-walled molded article, heat resistance, To provide a flame-retardant polylactic acid-based thermoplastic resin composition capable of providing a molded product having flame retardancy, moldability and appearance, and a molded product formed by molding this flame-retardant polylactic acid-based thermoplastic resin composition With the goal.

  As a result of diligent efforts to verify and improve the conventional technology, the present inventors have added 25 parts of polylactic acid resin by blending a specific flame retardant component with polylactic acid resin, rubber reinforced resin, and aromatic polycarbonate resin. It was discovered that, when contained by weight% or more, not only mechanical properties and heat resistance, but also a thin molded product can have the characteristics of having high flame retardancy at the same time, leading to the present invention.

That is, the gist of the present invention is a total of 25 to 67 parts by weight of the polylactic acid resin (A), 3 to 45 parts by weight of the rubber-reinforced resin (B), and 30 to 72 parts by weight of the aromatic polycarbonate resin (C). In addition, the phosphorus-based flame retardant (D) is included with respect to a total of 100 parts by weight of the polylactic acid resin (A), the rubber-reinforced resin (B), and the aromatic polycarbonate resin (C). 3 to 30 parts by weight, and a copolymer component of a dicarboxylic acid component comprising molecules cyclic phosphorus compound represented by the following formula (1), the phosphorus atom content 4% by weight or more of polyester-based flame retardant (E) 1 to 15 Parts by weight, 0.1 to 8 parts by weight of anti-dripping agent (F), 0.1 to 20 parts by weight of flame retardant auxiliary material (G) which is inorganic particles having an average particle size of 0.5 to 15 μm, and hydrolysis Flame retardant polylactic acid comprising 1 to 5 parts by weight of an inhibitor (H) The thermoplastic resin composition consists in.

  According to the present invention, the polylactic acid resin is contained in an amount of 25% by weight or more, and the properties such as flame retardancy, mechanical properties, heat resistance, etc., which are problems in the electric / electronic field, are solved, and are excellent. Molded articles can be provided with molding cycles equivalent to existing resins.

The rubber-reinforced resin (B) used in the present invention preferably contains a rubber-containing graft copolymer obtained by graft-polymerizing a hard (co) polymer to a rubbery polymer.
Further, as the anti-dripping agent (D), methacrylic acid ester polymer or a mixture of methacrylic acid ester and acrylic acid ester copolymer and fluorine (co) polymer, or fluorine (co) polymerization. A copolymer obtained by emulsion polymerization while adding methacrylic acid ester or methacrylic acid ester and acrylic acid ester in the presence of the product is preferable.

  Another gist of the present invention resides in a molded article formed by molding such a flame-retardant polylactic acid-based thermoplastic resin composition of the present invention.

In the present invention, “(co) polymer” is a general term for “polymer (homopolymer)” and “copolymer (copolymer)”. The same applies to “(co) polymer”, and “(co) polymerization” is a general term for “polymerization” and “copolymerization”.
In the present invention, the polylactic acid resin (A), aromatic polycarbonate resin (C) and the weight-average molecular weight (Mw) such as acetone-soluble components of the rubber-containing graft copolymer are all gel permeation. What was measured by dissolving in tetrahydrofuran (THF) with an association chromatography (GPC) is shown in terms of polystyrene (PS).

The flame-retardant polylactic acid-based thermoplastic resin composition of the present invention has a flame-retardant property of a thin molded product obtained by molding even if the composition contains 25% by weight or more of a polylactic acid resin. It has a good balance of mechanical properties such as impact strength and heat resistance, and has a good appearance. Therefore, it is a material suitable not only for the electronic / electric field but also for other fields.
According to the present invention, by providing a practical flame retardant polylactic acid-based thermoplastic resin composition as described above, the use of polylactic acid resin, which is a plant-based resin, is expanded, and the practice of the philosophy of carbon neutral is promoted. Therefore, it can contribute to the reduction of environmental load.

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

[Polylactic acid resin (A)]
The polylactic acid resin (A) applied to the resin composition of the present invention can be obtained by known means such as a method of directly dehydrating condensation polymerization of lactic acid or a method of ring-opening polymerization of lactide.

  There are three types of optical isomers, L-form, D-form, and DL-form, in the polylactic acid resin, and commercially available polylactic acid resins have L-form purity close to 100%. The polylactic acid resin (A) used in (1) does not particularly define its purity, and may be a copolymer containing other copolymerization components as long as the effects of the present invention are not impaired.

  Other copolymerization components contained in the polylactic acid resin (A) include ethylene glycol, propylene glycol, butanediol, heptanediol, hexanediol, octanediol, nonanediol, decanediol, 1,4-cyclohexanedimethano- , Neopentyl glycol, glycerin, pentaerythritol, bisphenol A, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and other glycol compounds; oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, Malonic acid, glutaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, anthracene dicarboxylic acid, 4, Dicarboxylic acids such as' -diphenyl ether dicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium isophthalic acid; hydroxycarboxylic acids such as glycolic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxybenzoic acid Examples include acids; lactones such as caprolactone, valerolactone, propiolactone, undecalactone, and 1,5-oxepan-2-one. The content of such a copolymer component is usually preferably 30 mol% or less and more preferably 10 mol% or less in all monomer components in the polylactic acid resin (A).

  The molecular weight and molecular weight distribution of the polylactic acid resin (A) are not particularly limited as long as it can be substantially molded, but the weight average molecular weight (Mw) is usually 10,000 or more, preferably 5 It is desirable that it is 10,000 or more, and 100,000 or more. Although there is no restriction | limiting in particular about the upper limit of the weight average molecular weight of a polylactic acid resin (A), Usually, it is 400,000 or less.

  The molecular weight can be measured by GPC (solvent THF: tetrahydrofuran), but when the polylactic acid resin is in a pellet form, it may be difficult to dissolve in THF. In that case, after dissolving in chloroform, The polymer component is precipitated using methanol, and the dried polymer component is dissolved in THF, and the molecular weight of the soluble component can be measured. Further, it can be dissolved by heating as necessary.

  In the present invention, the blending amount of the polylactic acid resin (A) in the flame retardant polylactic acid-based thermoplastic resin composition is that of the polylactic acid resin (A), the rubber-reinforced resin (B), and the aromatic polycarbonate-based resin (C). The range is 25 to 67 parts by weight with respect to 100 parts by weight in total, preferably 25 to 50 parts by weight, more preferably 35 to 45 parts by weight, and particularly the flame-retardant polylactic acid-based thermoplastic resin composition of the present invention. The content of 25 wt% or more, particularly 28 to 40 wt% in the product is preferable from the viewpoint of carbon neutral and improvement of impact resistance. If the blending amount of the polylactic acid resin (A) is less than this range, the object of the present invention for effectively using the polylactic acid resin cannot be achieved. If the blending amount is large, the flame retardant polylactic acid excellent in impact resistance and flame retardancy is not achieved. A thermoplastic resin molded product cannot be obtained.

  In addition, a polylactic acid resin (A) may be used individually by 1 type, and 2 or more types may be mixed and used for it.

  Specific examples of such a polylactic acid resin include, for example, “Lacia” manufactured by Mitsui Chemicals, Inc., “Nature Works” manufactured by Cargill-Dow, “Ecology” manufactured by Mitsubishi Plastics, Inc., and the like. Any of which can be used.

[Rubber reinforced resin (B)]
The rubber-reinforced resin (B) used in the present invention preferably contains a rubber-containing graft copolymer obtained by graft-polymerizing a hard (co) polymer to a rubbery polymer.

<Rubber-containing graft copolymer>
The rubber-containing graft copolymer used in the present invention has a structure in which a hard (co) polymer is graft-polymerized with a rubbery polymer, which is generally expressed by ABS, ASA, AES, MBS or the like.

  Examples of the rubbery polymer forming the rubber-containing graft copolymer include butadiene rubbers such as polybutadiene, styrene / butadiene copolymer, acrylate ester / butadiene copolymer, and styrene / isoprene copolymer. Conjugated diene rubbers; acrylic rubbers such as polybutyl acrylate; olefin rubbers such as ethylene / propylene copolymers; silicon rubbers such as polyorganosiloxanes, etc., these may be used alone or in combination A mixture of seeds or more can be used. These rubbery polymers can be used from monomers, and the structure of the rubbery polymer may take a composite rubber structure or a core / shell structure. Among these, a copolymer rubber polymer of polybutadiene and an acrylate ester, an enlarged rubber polymer thereof, and a rubber polymer having a polybutadiene as a core and an acrylate ester as a shell are preferable.

  The gel content of the rubbery polymer is preferably 50 to 99% by weight, more preferably 60 to 95% by weight, and particularly preferably 70 to 85% by weight. When the gel content is within this range, the properties of the obtained flame-retardant polylactic acid-based thermoplastic resin composition, particularly the impact strength, can be improved.

  In order to measure the gel content of the rubber polymer, specifically, the weighed rubber polymer was dissolved in an appropriate solvent at room temperature (23 ° C.) over 20 hours, and then 100 mesh. After separating with a wire mesh, the insoluble matter remaining on the wire mesh is dried at 60 ° C. for 24 hours and then weighed. The ratio (% by weight) of the insoluble matter with respect to the rubber polymer before fractionation is determined and used as the gel content of the rubber polymer. As the solvent used for dissolving the rubbery polymer, for example, toluene is used for polybutadiene and acetone is used for polybutyl acrylate.

  The particle size of the rubbery polymer is not particularly limited, but is preferably 0.1 to 1 μm, and more preferably 0.2 to 0.5 μm. The average particle size of the rubbery polymer can be measured by an optical method before graft polymerization. Further, after graft polymerization, the average particle diameter can be calculated using a transmission electron microscope (TEM) after dyeing the rubber polymer with a dyeing agent.

  The rubber-containing graft copolymer can be obtained by graft polymerization of 60 to 20% by weight of the monomer component capable of graft polymerization, preferably in the presence of 40 to 80% by weight of the above-mentioned rubbery polymer (however, provided that 100% by weight in total of rubbery polymer and monomer mixture). Here, if the rubber polymer is less than 40% by weight, the resulting flame-retardant polylactic acid-based thermoplastic resin molded article may not have impact resistance, and if it exceeds 80% by weight, impact resistance and There is a risk that fluidity may be reduced.

  Examples of monomer components capable of graft polymerization include vinyl cyanide monomers, aromatic vinyl monomers, methacrylic acid ester monomers, acrylic acid ester monomers, and maleimide compounds. Each monomer can be used alone or in combination of two or more.

Examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile, and acrylonitrile is particularly preferable.
Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, bromostyrene, and the like, and styrene and α-methylstyrene are particularly preferable.
Examples of the methacrylic acid ester monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and derivatives thereof. Among these, methyl methacrylate is particularly preferable.
Examples of the acrylate monomer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and derivatives thereof. Among these, methyl acrylate is particularly preferable.
Examples of the maleimide compound include N-phenylmaleimide, N-cyclohexylmaleimide and the like.

  Moreover, the monomer modified | denatured by the functional group by the case may be included, for example, acrylic acid, methacrylic acid, itaconic acid, fumaric acid etc. are mentioned as unsaturated carboxylic acid. These can be used individually by 1 type or in mixture of 2 or more types. The proportion of use is preferably 30% by weight or less, particularly preferably 10% by weight or less, based on 100% by weight in the monomer mixture.

  The monomer component to be grafted by the rubber-containing graft copolymer may be a combination of a vinyl cyanide monomer and an aromatic vinyl monomer among the above exemplified monomers. Examples of the vinyl halide monomer include acrylonitrile, and examples of the aromatic vinyl monomer include styrene. In the combination of vinyl cyanide monomer and aromatic vinyl monomer, the weight ratio of each monomer of vinyl cyanide monomer / aromatic vinyl monomer is 20/80 to 35 / The range of 65 is preferable, and more preferably 25/75 to 30/70. Outside this range, dispersibility and thermal stability may be reduced.

  As the monomer component to be grafted of the rubber-containing graft copolymer, only a methacrylic ester monomer or a combination of a methacrylic ester monomer and an acrylate ester monomer is preferable. From the point of further improving the impact resistance of the resulting flame-retardant polylactic acid-based thermoplastic resin molded product, methyl methacrylate as the methacrylic ester monomer, and methyl acrylate as the acrylate monomer. preferable. Methacrylic acid ester monomer alone or in combination of methacrylic acid ester monomer and acrylic acid ester monomer, each monomer of methacrylic acid ester monomer / acrylic acid ester monomer The weight ratio is preferably 100/0 to 50/50, more preferably 99/1 to 80/20. When the amount of the acrylic ester monomer exceeds this range, the thermal stability and heat resistance of the obtained flame-retardant polylactic acid-based thermoplastic resin composition tend to be impaired.

  The weight average molecular weight of the acetone-soluble component of the rubber-containing graft copolymer is preferably in the range of 30,000 to 250,000, more preferably 40,000 to 150,000, and still more preferably 45,000 to 100. , 000. If the weight-average molecular weight of the acetone-soluble part of the rubber-containing graft copolymer is lower than this range, the resulting flame-retardant polylactic acid-based thermoplastic resin molded product has insufficient impact resistance, and exceeds this range. In such a case, the moldability of the flame retardant polylactic acid-based thermoplastic resin composition may be reduced. The acetone-soluble component corresponds to a polymer product of a monomer that is not graft-polymerized to the rubbery polymer that is generated when the monomer is graft-polymerized to the rubbery polymer.

  Further, the graft ratio of the rubber-containing graft copolymer ((acetone insoluble matter weight / rubber polymer weight-1) × 100) is preferably 15 to 120% by weight, and more preferably 20 to 85% by weight. When the graft ratio is lower than 15% by weight, the dispersibility of the rubbery polymer is lowered and the impact strength is reduced. When the graft ratio is higher than 120% by weight, the impact resistance and molding are reduced. Tend to decrease. The grafted copolymer may have a structure occluded not only inside but also inside the rubbery polymer.

  Graft polymerization can be carried out by known emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization, and may be a method combining these polymerization methods. As the rubber-containing graft copolymer, two or more kinds of rubber-containing graft copolymers having different polymerization methods and component compositions may be mixed and used.

<Blending amount>
In this invention, the compounding quantity of the rubber reinforced resin (B) in a flame-retardant polylactic acid-type thermoplastic resin composition is polylactic acid resin (A), rubber reinforced resin (B), and aromatic polycarbonate-type resin (C). Although it is in the range of 3 to 45 parts by weight with respect to 100 parts by weight in total, it is preferably 5 to 30 parts by weight, more preferably 10 to 15 parts by weight, from the viewpoint of carbon neutral and improvement in impact resistance. This is preferable. If the blending amount of the rubber reinforced resin (B) is less than this range, the impact resistance is lowered and the appearance is inferior, which is not preferred, and if it is more, the flame retardancy and heat resistance are lowered.

[Aromatic polycarbonate resin (C)]
The aromatic polycarbonate resin (C) used in the present invention can be produced by reaction of one or more bisphenols with phosgene or carbonic acid diester, and the weight average molecular weight (Mw) is 10,000 to 50,000. In particular, the range of 13,000 to 40,000 is preferable. If the weight average molecular weight (Mw) of the aromatic polycarbonate resin (C) is lower than this range, the impact resistance and flame retardancy tend to decrease. Due to the inferiority, the appearance of the product tends to be inferior.

  Specific examples of bisphenols that are raw materials for the aromatic polycarbonate resin (C) include hydroquinone, 4,4-dihydroxyphenyl, bis- (4-hydroxyphenyl) -alkane, and bis- (4-hydroxyphenyl) -cyclo. Alkanes, bis- (4-hydroxyphenyl) -sulfides, bis- (4-hydroxyphenyl) -ethers, bis- (4-hydroxyphenyl) -ketones, bis- (4-hydroxyphenyl) -sulfones, or alkyls thereof A substituted body, an aryl substituted body, a halogen substituted body, etc. are mentioned, These can be used individually by 1 type or in combination of 2 or more types.

  Said aromatic polycarbonate-type resin may be used individually by 1 type, or may mix and use 2 or more types.

  In the present invention, the blending amount of the aromatic polycarbonate resin (C) in the flame retardant polylactic acid thermoplastic resin composition is as follows: polylactic acid resin (A), rubber reinforced resin (B), and aromatic polycarbonate resin (C). ) In the range of 30 to 72 parts by weight, preferably 45 to 65 parts by weight, more preferably 45 to 55 parts by weight, from the viewpoint of carbon neutral and impact resistance. It is preferable in terms of improving flame retardancy and heat resistance. If the amount of the aromatic polycarbonate resin (C) is larger than this range, the object of the present invention for effectively using the polylactic acid resin cannot be achieved, and if it is less, the impact resistance, flame retardancy and heat resistance are excellent. A flame-retardant polylactic acid-based thermoplastic resin molded article cannot be obtained.

[Phosphorus flame retardant (D)]
Examples of the phosphorus-based flame retardant (D) used in the present invention include red phosphorus and phosphorus compounds. Examples of the phosphorus compound include phosphine, phosphine oxide, bisphosphine, phosphonium salt, phosphinate, phosphate, Examples thereof include phosphoric acid esters. Of these, phosphate ester-based flame retardants are preferred in that there is no problem of mold contamination or generation of corrosive gas during molding. Examples of the phosphate ester flame retardant include a phosphoric acid ester compound represented by the following general formula (I) and a condensed phosphoric acid ester compound represented by the following general formula (II), which are molecular cyclic phosphoric acids. It does not take an ester structure.

(In the formula (I), R ¹ , R ² and R ³ are each independently an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be alkyl-substituted) And n is 0 or 1.)

(In the formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent an aryl group or an alkaryl group, X represents an arylene group, j, k, l, And m are each independently 0 or 1. N is an integer of 1 to 5, but in the case of a mixture of phosphate ester compounds, N represents an average value (1 ≦ N ≦ 5). .)

  Specific examples of the phosphoric acid ester compound represented by the general formula (I) include bis- (phenyl) -methyl phosphate, bis- (ethyl) -phenyl phosphate, bis- (ethyl) -2,6-dimethylphenyl. Phosphate, bis- (phenyl) -ethyl phosphate, bis- (phenyl) -butyl phosphate, bis- (neopentyl) -phenyl phosphate, bis- (4-methylphenyl) -2-ethylhexyl phosphate, bis- (2-ethylhexyl) -Phenyl phosphate, bis- (phenyl) -2-ethylhexyl phosphate, bis- (phenyl) -octyl phosphate, bis- (octyl) phenyl phosphate, bis- (3,5,5-trimethylhexyl) phenyl phosphate, bis- ( 2,5,5-trimethyl Xyl) -4-methylphenyl phosphate, bis- (phenyl) -isodecyl phosphate, bis- (dodecyl) -4-methylphenyl phosphate, bis- (dodecyl) phenyl phosphate, tris- (phenyl) phosphate, tris- (2 -Methylphenyl) phosphate, tris- (4-methylphenyl) phosphate, bis- (2-methylphenyl) phenyl phosphate, bis- (4-methylphenylphenyl) phenyl phosphate, bis- (phenyl) -2-methylphenyl phosphate Bis- (phenyl) -4-methylphenyl phosphate, tris- (isopropylphenyl) phosphate, bis- (isopropylphenyl) phenyl phosphate, bis- (phenyl) -isopropylphenyl phosphate, Lis- (nonylphenyl) phosphate, tris- (2,6-dimethylphenyl) phosphate, bis- (2,6-dimethylphenyl) phenyl phosphate, bis- (2,6-dimethylphenyl) -2,6-dimethylphenyl Phosphate, bis- (2,6-dimethylphenyl) -4-t-butylphenyl phosphate, bis- (2,6-dimethylphenyl) -4-methylphenyl phosphate, bis- (2,6-dimethylphenyl) -3 -Methylphenyl phosphate, bis- (2,6-dimethylphenyl) -4-isopropylphenyl phosphate, bis- (2,6-dimethylphenyl) -2-isopropylphenyl phosphate, and these are used alone. Or two or more of them may be used in combination.

Moreover, the condensed phosphate ester compound represented by the general formula (II) may be used alone or in combination of two or more. Therefore, in the said general formula (II), the value of N does not necessarily need to be an integer, and in the case of a mixture, it represents the average value in the mixture of a condensed phosphate ester compound. In the general formula (II), R ⁴ , R ⁵ , R ⁶ and R ⁷ are preferably cresyl group, phenyl group, xylenyl group, propylphenyl group, butylphenyl group, and the arylene group of X is, for example, resorcinol, It may be a group derived from hydroquinone, bisphenol A and dihydroxy compounds such as chlorinated compounds and brominated compounds thereof, or may be a phenylene group.

  As the phosphoric flame retardant, the above phosphoric acid ester compound and the condensed phosphoric acid ester may be used in combination.

  In the present invention, the compounding amount of the phosphorus-based flame retardant (D) in the flame-retardant polylactic acid-based thermoplastic resin composition is as follows: polylactic acid resin (A), rubber-reinforced resin (B), and aromatic polycarbonate-based resin (C). Although it is in the range of 3 to 30 parts by weight with respect to a total of 100 parts by weight, preferably 6 to 28 parts by weight, more preferably 18 to 22 parts by weight, flame retardancy, impact resistance, heat resistance This is preferable. If the blending amount of the phosphorus-based flame retardant (D) is less than this range, sufficient flame retardancy will not be exhibited, and if it is greater, problems such as heat resistance and impact resistance will occur.

[Polyester flame retardant (E)]
The polyester-based flame retardant (E) used in the present invention was produced using a dicarboxylic acid component containing a molecular cyclic phosphorus compound represented by the following formula (1) as a raw material copolymerization component, and a phosphorus atom content of 4% by weight. It is the above polyester.

  The phosphorus atom content of the polyester-based flame retardant (E) is 4% by weight or more from the viewpoint of enhancing flame retardancy. If the phosphorus atom content is lower than this, a sufficient flame retardancy improving effect by the polyester flame retardant (E) cannot be obtained. Also, from the viewpoint of industrial mass productivity, the phosphorus atom content is usually preferably 6% by weight or less.

  The polyester-based flame retardant (E) used in the present invention can be produced by the method described in Patent Document 4 (International Publication WO2006 / 057228 Pamphlet), but the molecular cyclic phosphorus compound represented by the above formula (1) Is a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (hereinafter sometimes abbreviated as “DOP”) represented by the following formula (2); The polyester-based flame retardant (E) used in the present invention can be produced by an addition reaction with itaconic acid represented by the formula (3), and this reaction can occur in the production process of the polyester. Is produced by using a polyester production raw material (copolymerization component) containing DOP, itaconic acid, other dicarboxylic acid components and a diol component in accordance with a conventional method. It can be produced by performing a response.

  In particular, the polyester-based flame retardant (E) according to the present invention includes terephthalic acid and / or an ester-forming derivative thereof such as dimethyl terephthalate and the like, a molecular cyclic phosphorus compound represented by the formula (1), and trifunctional. The carboxylic acid component containing the above polyvalent carboxylic acid component is preferably obtained by reacting a diol component. Here, terephthalic acid and / or an ester-forming derivative thereof is a carboxylic acid used in the reaction. It is preferable that it is 50 mol% or more with respect to the total amount of an acid component, especially 55-70 mol%. Further, the molecular cyclic phosphorus compound represented by the formula (1) is preferably 30 mol% or more, particularly 30 to 50 mol%, based on the total amount of the carboxylic acid component used in the reaction. The trifunctional or higher polyvalent carboxylic acid component is preferably 0.05 to 2.0 mol%, particularly preferably 0.30 to 0.70 mol%, based on the total amount of the carboxylic acid component used in the reaction.

If the amount of terephthalic acid and / or its ester-forming derivative is less than the above range, the material itself is fragile and the productivity deteriorates, so that industrial mass production is difficult. The amount of the molecular cyclic phosphorus compound and the polyfunctional carboxylic acid component having three or more functional groups is reduced, and the effects of these components cannot be obtained.
In addition, even if the molecular cyclic phosphorus compound represented by the formula (1) is less or more than the above range, the phosphorus atom content of the obtained polyester flame retardant (E) can be within the above preferable range. Disappear.

  The trifunctional or higher polyvalent carboxylic acid component is used to promote the polymerization reaction using the molecular cyclic phosphorus compound represented by the formula (1) due to its thickening action. If the amount is too small, the effect of thickening due to the use thereof cannot be sufficiently obtained. If the amount is too large, it is difficult to control the polymerization reaction.

  Trifunctional or higher polyvalent carboxylic acid components include trimellitic acid, ethanetricarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, pyromellitic acid, trimesic acid, 3,4,3 ′, 4′-biphenyltetra. Examples thereof include carboxylic acids and ester moldable derivatives thereof.

  On the other hand, ethylene glycol, ethylene oxide, or the like can be used as the diol component.

  In addition, as a manufacturing raw material of the polyester-type flame retardant (E) used by this invention, you may further use carboxylic acid components other than the above, a trifunctional or more polyhydric polyol component, etc.

  The intrinsic viscosity (molecular weight) of the polyester flame retardant (E) produced in this manner is 0.4 dl / g or more and 0.7 dl / g or less, and it has flame resistance, impact resistance, and heat resistance. It is preferable in terms. If the intrinsic viscosity is lower than this range, problems may be caused in appearance defects, impact resistance, and heat resistance, and if the intrinsic viscosity is higher than this range, problems may occur in flame retardancy.

  In this invention, the compounding quantity of the polyester-type flame retardant (E) in a flame-retardant polylactic acid-type thermoplastic resin composition is polylactic acid resin (A), rubber reinforced resin (B), and aromatic polycarbonate-type resin (C). 1 to 15 parts by weight with respect to a total of 100 parts by weight, preferably 5 to 15 parts by weight, more preferably 7 to 14 parts by weight, flame resistance, impact resistance, heat resistance This is preferable. If the blending amount of the polyester-based flame retardant (E) is less than this range, sufficient flame retardancy in a thin-walled molded product is not expressed, and if it is large, problems arise in heat resistance and impact resistance.

[Anti-drip agent (F)]
In the present invention, as the anti-dripping agent (F), a methacrylic acid ester polymer or a copolymer of a methacrylic acid ester and an acrylic acid ester and a fluorinated (co) polymer is copolymerized or mixed. Can be mentioned. Among these, in the case of copolymerization, for example, there is a method of emulsion polymerization while adding a methacrylic acid ester or a methacrylic acid ester and an acrylic acid ester to a fluorine-based (co) polymer. In the case of a mixture of a methacrylic acid ester polymer or a copolymer of a methacrylic acid ester and an acrylic acid ester and a fluorine-based (co) polymer, the mixing method includes latex and latex blend, latex and powder A blend, a blend of beads and latex, a blend of beads and powder, and the like can be mentioned, and a latex blend is more preferable.

  Specific examples of such an anti-dripping agent (F) include, for example, commercially available products “Metbrene A-3000” and “Metbrene A-3800” manufactured by Mitsubishi Rayon Co., Ltd.

  Examples of the acrylate ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, n-hexyl acrylate, n-heptyl acrylate, N-octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate, and the like, acrylate aliphatic hydrocarbon (e.g., alkyl having 1 to 18 carbon atoms) ester; cyclohexyl acrylate Acrylic acid alicyclic hydrocarbon esters such as isobornyl acrylate; Acrylic aromatic hydrocarbon esters such as phenyl acrylate and toluyl acrylate; Aralkyl acrylates such as benzyl acrylate; 2-methoxyethyl acrylate Esters of acrylic acid such as 3-methoxybutyl acrylate and functional group-containing alcohols having etheric oxygen; trifluoromethyl methyl acrylate, 2-trifluoromethyl ethyl acrylate, 2-perfluoroethyl ethyl acrylate, acrylic 2-perfluoroethyl-2-perfluorobutylethyl acid, 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethyl methyl acrylate, 2-perfluoromethyl-2-perfluoroethyl methyl acrylate And fluorinated alkyl acrylates such as 2-perfluorohexylethyl acrylate, 2-perfluorodecylethyl acrylate, 2-perfluorohexadecylethyl acrylate, and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Examples of the methacrylate ester include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, n-heptyl methacrylate, N-octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate, stearyl methacrylate, and the like, methacrylic acid aliphatic hydrocarbon (eg, alkyl having 1 to 18 carbon atoms) ester; cyclohexyl methacrylate , Methacrylic acid alicyclic hydrocarbon esters such as isobornyl methacrylate; methacrylic acid aralkyl esters such as benzyl methacrylate; methacrylic acid aroma such as phenyl methacrylate and toluyl methacrylate Hydrocarbon esters; esters of methacrylic acid such as 2-methoxyethyl methacrylate and 3-methoxybutyl methacrylate with functional group-containing alcohols having etheric oxygen; trifluoromethyl methyl methacrylate, 2-trifluoromethyl ethyl methacrylate 2-perfluoroethylethyl methacrylate, 2-perfluoroethyl-2-perfluorobutylethyl methacrylate, 2-perfluoroethyl methacrylate, perfluoromethyl methacrylate, diperfluoromethyl methyl methacrylate, methacrylic acid 2 -Methacrylates such as perfluoromethyl-2-perfluoroethylmethyl, 2-perfluorohexylethyl methacrylate, 2-perfluorodecylethyl methacrylate, 2-perfluorohexadecylethyl methacrylate An acid fluorinated alkyl esters. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Fluorine (co) polymers include ethylene difluoride polymers, ethylene trifluoride polymers, tetrafluoroethylene polymers, vinylidene fluoride polymers, tetrafluoroethylene / hexafluoropropylene copolymers, etc. Among these, a tetrafluoroethylene polymer is preferable, and the number average molecular weight (Mn) is 500,000 or more, for example, 600,000 to 10,000,000 is a balance between impact property and fluidity. Is preferred. The molecular weight can be calculated from the standard specific gravity.

  The ratio of methacrylic acid ester and acrylic acid ester of the methacrylic acid ester polymer or methacrylic acid ester / acrylic acid ester copolymer constituting the anti-dripping agent (F) is methacrylic acid ester: acrylic acid ester = 1: 0. 1 (weight ratio) is preferable. If the amount of acrylic acid ester is larger than this range and the amount of methacrylic acid ester is small, impact resistance is lowered and thermal stability is inferior.

  The ratio of methacrylic acid ester polymer or methacrylic acid ester / acrylic acid ester copolymer to fluorine (co) polymer is as follows: methacrylic acid ester polymer or methacrylic acid ester / acrylic acid ester copolymer: fluorine type It is preferable that (co) polymer = 1: 0.1 to 4 (weight ratio). If the amount of the methacrylic acid ester polymer or the methacrylic acid ester / acrylic acid ester copolymer is larger than this range and the fluorine-based (co) polymer is small, the combustibility is lowered. On the contrary, when there are many fluorine-type (co) polymers and there are few methacrylic acid ester polymers or methacrylic acid ester-acrylic acid ester copolymer, fluidity | liquidity will deteriorate or an external appearance may deteriorate.

  In this invention, the compounding quantity of the dripping inhibitor (F) in a flame-retardant polylactic acid-type thermoplastic resin composition is polylactic acid resin (A), rubber reinforcement resin (B), and aromatic polycarbonate-type resin (C). Although it is the range of 0.1-8 weight part with respect to a total of 100 weight part, Preferably it is 1-6 weight part, More preferably, it is preferable in terms of impact resistance that it is 2-5 weight part. If the blending amount of the anti-dripping agent (F) is less than this range, the impact resistance improving effect is not expressed, and if it is too large, problems occur in the moldability and the appearance of the molded product.

[Flame retardant auxiliary material (G)]
Examples of the flame retardant auxiliary material (G) that can be used in the present invention include inorganic particles such as talc and mica, and preferably inorganic particles such as talc and mica that have been surface-treated with a silane coupling agent.

  In the case of inorganic particles surface-treated with a silane coupling agent, the coating amount of the silane coupling agent is usually 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the base particles. is there. As the silane coupling agent, one having a functional group such as an epoxy group, an amino group, a vinyl group, or a hydroxyl group can be used. As this functional group, an epoxy group or an amino group is preferable.

  By using such a flame retardant auxiliary material (G), flame retardancy, particularly high flame retardancy, can be imparted without impairing mechanical properties and heat resistance. As the flame retardant auxiliary material (G), talc, particularly talc surface-treated with a silane coupling agent, is particularly preferable.

The flame retardant auxiliary material (G) used in the present invention exhibits an effect of assisting in flame retardancy, particularly high flame retardancy, by being uniformly dispersed in the flame retardant polylactic acid thermoplastic resin composition. To do. Therefore, the average particle diameter of the inorganic particles of the flame retardant auxiliary material (G) is 0.5 to 15 μm, preferably 1 to 15 μm, more preferably 1.3 to 13 μm. When the average particle size of the flame retardant auxiliary material (G) is less than 0.5 μm, it tends to agglomerate when kneaded into the resin, so that not only the appearance of the molded product is deteriorated but also the flame retardancy is stabilized. To lose. When the average particle diameter exceeds 15 μm, not only the physical properties such as impact resistance are lowered, but also the stabilization of flame retardancy is impaired.
The particle diameter of the flame retardant auxiliary material (G) can be measured by a sedimentation method, a laser diffraction method, or the like, but is particularly easy to perform the laser diffraction method.

  In the present invention, the blending amount of the flame retardant auxiliary material (G) in the flame retardant polylactic acid-based thermoplastic resin composition is as follows: polylactic acid resin (A), rubber-reinforced resin (B), and aromatic polycarbonate-based resin (C). Although it is in the range of 0.1 to 20 parts by weight with respect to a total of 100 parts by weight, more preferably 3 to 15 parts by weight, particularly preferably 7 to 10 parts by weight, flame retardancy and mechanical properties. This is preferable. If the blending amount of the flame retardant auxiliary material (G) is less than this range, a sufficient flame retardant auxiliary effect cannot be obtained, and if it is large, a problem occurs in impact resistance and the like.

[Hydrolysis inhibitor (H)]
The hydrolysis inhibitor (H) used in the present invention is preferably a carbodiimide compound having one or more carbodiimide groups in the molecule, more preferably an aliphatic polycarbodiimide.
In addition, the carbodiimide compound is preferably used in combination with an antioxidant, and as a method for adding the antioxidant, it may be added as a single antioxidant in the pelletizing step of the thermoplastic resin composition. A rubber-containing graft copolymer to which an antioxidant is added may be used.

  As the carbodiimide compound having one or more carbodiimide groups in the molecule used in the present invention, those synthesized by a generally well-known method can be used, for example, an organophosphorus compound as a catalyst. Alternatively, those synthesized by subjecting various polyisocyanates to a decarboxylation condensation reaction in a solvent-free or inert solvent at a temperature of about 70 ° C. or higher using an organometallic compound can be used.

  Examples of monocarbodiimide compounds that can be used in the present invention include N, N′-diphenylcarbodiimide, N, N′-di-2,6-diisopropylphenylcarbodiimide, and the like.

  In the present invention, a polycarbodiimide compound can also be suitably used. As the polycarbodiimide compound, those produced by various methods can be used, but basically, a conventional method for producing a polycarbodiimide compound (for example, Japanese Patent Publication No. 47-33279, J. 0 rg. Chem). 28, 2069-2075 (1963), Chemical Review 10981, Vol. 81 No. 4, p619-621) can be used.

  As the organic diisocyanate which is a synthesis raw material in the production of the polycarbodiimide compound used in the present invention, aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and mixtures thereof can be used.

Examples of the aromatic isocyanate include 1,5-naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2, 4-tolylene diisocyanate, 2,6-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, 2,6-diisopropylphenyl isocyanate, Examples thereof include 1,3,5-triisopropylbenzene-2,4-diisocyanate.
Examples of the aliphatic diisocyanate include hexamethylene diisocyanate.
Examples of the alicyclic diisocyanate include cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, and methylcyclohexane diisocyanate.

  Moreover, in the case of the said polycarbodiimide compound, a polymerization reaction can be stopped on the way by cooling etc., and it can control to a suitable polymerization degree. In this case, the terminal is an isocyanate group. Furthermore, in order to control the degree of polymerization to an appropriate degree, there is a method in which all or part of the remaining terminal isocyanate is sealed using a compound that reacts with the terminal isocyanate of the polycarbodiimide compound, such as monoisocyanate. By controlling the degree of polymerization, compatibility with the resin and storage stability can be improved, which is preferable in terms of quality improvement.

  Examples of the monoisocyanate for sealing the end of such a polycarbodiimide compound and controlling the degree of polymerization thereof include phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate and the like. .

Further, the end-capping agent that seals the end of the polycarbodiimide compound and controls the degree of polymerization thereof is not limited to the above-mentioned monoisocyanate, and an active hydrogen compound that can react with isocyanate, for example,
(I) an aliphatic, aromatic or alicyclic compound having an —OH group, methanol, ethanol, phenol, cyclohexanol, N-methylethanolamine, polyethylene glycol monomethyl ether, polypropylene glycol monomethyl ether (ii) = diethylamine with an NH group, butylamine with dicyclohexylamine (iii) -NH ₂ group, succinic acid with cyclohexylamine (iv) -COOH group, ethyl mercaptan with benzoic acid, cyclohexane acid (v) -SH, allyl mercaptan Thiophenol (vi) compounds having an epoxy group (vii) acetic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc. Have group What to do is desirable.

The decarboxylation condensation reaction of the organic diisocyanate is carried out in the presence of a suitable carbodiimidization catalyst. Examples of the carbodiimidization catalyst that can be used include organic phosphorus compounds, organometallic compounds (general formula M- (OR) ₄ (Where M is titanium (Ti), sodium (Na), potassium (K), vanadium (V), tungsten (W), hafnium (Hf), zirconium (Zr), lead (Pb), manganese (Mn ), Nickel (Ni), calcium (Ca), barium (Ba) and the like, wherein R represents an alkyl group having 1 to 20 carbon atoms or an aryl group)), and particularly active From the aspect, phospholene oxides are preferable for organic phosphorus compounds, and alkoxides of titanium, hafnium, and zirconium are preferable for organic metal compounds.

  Specific examples of the phosphorene oxides include 3-methyl-1-phenyl-2-phospholene-1-oxide, 3-methyl-1-ethyl-2-phospholene-1-oxide, 1,3- Dimethyl-2-phospholene-1-oxide, 1-phenyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 1-methyl-2-phospholene-1-oxide or a double of these Examples of the bond isomer can be exemplified, and 3-methyl-1-phenyl-2-phospholene-1-oxide which is easily available industrially is particularly preferable.

  In the present invention, the blending amount of the hydrolysis inhibitor (H) in the flame-retardant polylactic acid-based thermoplastic resin composition is as follows: polylactic acid resin (A), rubber-reinforced resin (B), and aromatic polycarbonate-based resin (C). Is 1 to 5 parts by weight, preferably 1 to 3.5 parts by weight, more preferably 1 to 3 parts by weight, from the viewpoint of durability. If the blending amount of the hydrolysis inhibitor (H) is less than this range, the effect of improving the durability is not expressed. If the blending amount is large, there are problems in flame retardancy, mechanical properties, and the like.

[Phosphorus atom content]
The flame-retardant polylactic acid-based thermoplastic resin composition of the present invention contains the phosphorus-based flame retardant (D) and the polyester-based flame retardant (E), so that the phosphorus atom content in the composition is 1.80. It is preferable that it is ˜2.50% by weight, particularly 1.95 to 2.35% by weight. If the phosphorus atom content in the composition is less than the above lower limit, sufficient flame retardancy cannot be obtained, and if it is greater, there will be problems in impact resistance and heat resistance.

[Other ingredients]
The flame-retardant polylactic acid-based thermoplastic resin composition of the present invention includes the polylactic acid resin (A), rubber-reinforced resin (B), aromatic polycarbonate-based resin (C), phosphorus-based flame retardant (D), and polyester-based resin. In addition to the flame retardant (E), the anti-dripping agent (F), the flame retardant auxiliary material (G), and the hydrolysis inhibitor (H), various additives and other resins can be further blended. In this case, various additives include known antioxidants, ultraviolet absorbers, lubricants, plasticizers, stabilizers, mold release agents, antistatic agents, colorants (pigments, dyes, etc.), carbon fibers, glass fibers, One type or two or more types of fillers such as wollastonite, calcium carbonate and silica, anti-drip agents, antibacterial agents, anti-fungal agents, silicone oils and coupling agents may be mentioned.

  Other resins include rubber-reinforced styrene resins such as HIPS resin, ABS resin, ASA resin, AES resin, AS resin, polystyrene resin, polyacetal resin, nylon resin, methacrylic resin, polyvinyl chloride resin, Examples include polyphenylene ether resin. Also, a blend of two or more of these may be used, and the above resin modified with a compatibilizer or a functional group may be blended.

[Production and molding of polylactic acid-based thermoplastic resin composition]
The method for pelletizing the flame-retardant polylactic acid-based thermoplastic resin composition of the present invention is not particularly limited, and for example, a twin-screw extruder, a Banbury mixer, a heating roll, etc. can be used. Melt kneading by a machine is preferable, and if necessary, resin and other additives can be blended by side feed or the like.

  The flame-retardant polylactic acid-based thermoplastic resin composition of the present invention can be molded into various molded products by ordinary molding methods such as injection molding, blow molding, sheet molding, vacuum molding, etc. In particular, injection molding is preferred.

  Although there is no restriction | limiting in particular as a use of the obtained molded article, The electric / electronic field, an automobile field, an optical field, a building material field etc. are mentioned, Especially suitable for the use as various housing | casings and structural members, such as an electronic / electric field. Can be used.

  In addition, the molded product formed by molding the flame-retardant polylactic acid-based thermoplastic resin composition of the present invention has good secondary decorating properties such as painting, plating and vapor deposition, and secondary workability such as welding and cutting. Yes, it can be expanded to wider fields and members.

  In addition, when preparing each component of the flame-retardant polylactic acid-based thermoplastic resin composition of the present invention, or when mixing, kneading, or molding these components, the resin waste, etc. is left as it is or when Can be crushed and subjected to a melt regeneration process. In this case, it can be recovered during molding, but it can also be recovered separately and used as a raw material in the above-described pellet manufacturing process.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to synthesis examples, examples, and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
In the following, “part” means “part by weight”.

In the following, the weight average molecular weight was measured by a standard PS (polystyrene) conversion method using Tosoh Co., Ltd .: GPC (gel permeation chromatography, solvent: THF).
The average particle diameter of the rubber polymer was determined by a dynamic light scattering method using Nikkiso Co., Ltd .: Microtrac Model: 9230UPA.
The weight composition ratio of the monomer was determined using FT-IR manufactured by Horiba Ltd.

[Raw materials]
<Polylactic acid resin (A)>
Polylactic acid resin (a-1): biodegradable polymer (L-form / D-form = 98/2 (weight ratio),
(Weight average molecular weight = 140,000, melting point = 171 ° C.)
<Aromatic polycarbonate resin (C)>
Aromatic polycarbonate resin (c-1): made by Mitsubishi Engineering Plastics Co., Ltd.
"Iupilon E2000F"
(Weight average molecular weight (Mw) 27,000)
<Phosphorus flame retardant (D)>
Phosphorus flame retardant (d-1): “PX-200” manufactured by Daihachi Chemical Industry Co., Ltd.
<Flame retardant auxiliary material (G)>
Flame retardant auxiliary material (g-1): “TP-A25” manufactured by Fuji Talc Kogyo Co., Ltd. (average particle diameter 5.1 μm by laser diffraction method) 100 parts by weight of epoxy silane (A-187) made of NUC silicone Surface treated with 1 part by weight <Hydrolysis inhibitor (H)>
Hydrolysis inhibitor (h-1): “Carbodilite HMV-8CA” manufactured by Nisshinbo Co., Ltd.

[Synthesis of rubber-reinforced resin (rubber-containing graft copolymer) (B)]
<Synthesis Example 1: Production of rubber-containing graft copolymer (b-1)>
A rubber-containing graft copolymer was synthesized by the emulsion polymerization method with the following raw material composition.
(Raw material combination)
Styrene (ST) 24.5 parts Acrylonitrile (AN) 10.5 parts Polybutadiene latex 65 parts (as solids)
Disproportionated potassium rosinate 1 part Potassium hydroxide 0.03 part Tertiary decyl mercaptan (t-DM) 0.04 part Cumene hydroperoxide 0.3 part Ferrous sulfate 0.007 part Sodium pyrophosphate 0.1 Part Crystalline glucose 0.3 part Distilled water 190 part

  An autoclave is charged with distilled water, disproportionated potassium rosinate, potassium hydroxide and polybutadiene latex (gel content 95% by weight, average particle size 0.3 μm), heated to 60 ° C., added with crystalline glucose, 60 ° C. ST, AN, t-DM and cumene hydroperoxide were added while maintaining the temperature, and ferrous sulfate and sodium pyrophosphate were continuously added over 2 hours, then the temperature was raised to 70 ° C. and maintained for 1 hour. Completed. An antioxidant was added to the ABS latex obtained by this reaction, then coagulated with sulfuric acid, sufficiently washed with water, and dried to obtain an ABS graft copolymer (b-1).

<Synthesis Example 2: Production of rubber-containing graft copolymer (b-2)>
In the raw material blend of Synthesis Example 1, 60 parts (as solid content) of polybutyl acrylate (gel content 65% by weight, average particle size 0.34 μm) was used as a rubbery polymer, and methyl methacrylate (MMA) was used as a monomer. ) Graft polymerization was performed in the same manner as in Synthesis Example 1 except that 36 parts and 4 parts of methyl acrylate (MA) were reacted to obtain a rubber-containing graft copolymer (b-2).

<Synthesis Example 3: Production of rubber-containing graft copolymer (b-3)>
1) Production of rubber-like copolymer latex (r-1) [raw material blending]
Butyl acrylate 60 parts 1,3-Butadiene 40 parts Diisopropylbenzene hydroperoxide 0.2 parts Tallow fatty acid potassium 1 part N-lauroyl sarcosine sodium salt 0.5 parts Sodium pyrophosphate 0.005 parts Ferrous sulfate 0.005 Dextrose 0.3 parts Deionized water 200 parts

  Among the components of the above raw material blend, components other than 1,3-butadiene were substituted with nitrogen to make the polymerization reaction substantially uninhibited. Thereafter, all components were charged into an autoclave and polymerized at 50 ° C. The polymerization was almost completed in 9 hours, and a rubbery copolymer latex (r-1) having a conversion rate of 97% and a particle size of 0.07 μm was obtained.

2) Manufacture of acid group-containing copolymer latex (A-1) for enlargement The following mixture of the first raw material was polymerized at 70 ° C. for 1.5 hours in a 5 l glass round bottom flask. Thereafter, at 70 ° C., the mixture of the raw material composition in the second stage below was dropped over 1 hour, and then stirred for 1 hour, and the acid group-containing copolymer latex for enlargement (A-1) at a conversion rate of 98%. )

[First stage raw material formulation]
N-butyl acrylate 25 parts potassium oleate 2 parts sodium dioctylsulfosuccinate 1 part cumene hydroperoxide 0.1 part sodium formaldehyde sulfoxylate 0.3 part deionized water 200 parts [2nd stage raw material formulation]
n-Butyl acrylate 60 parts Methacrylic acid 15 parts Cumene hydroperoxide 0.3 parts

3) Production of enlarged rubbery polymer (R-1) While stirring the autoclave containing the rubbery copolymer latex (r-1) containing 100 parts of polymer solid content, the temperature is kept at 50 ° C. for 15 minutes. Then, 4 parts of the above-mentioned enlargement acid group-containing copolymer latex (A-1) was added and held for 30 minutes. Further, 10 parts of a 5% by weight aqueous sodium sulfate solution was added and held for 1 hour to obtain an enlarged rubbery polymer (R-1). The average particle size of the resulting enlarged rubbery polymer (R-1) was 0.21 μm.

4) Production of rubber-containing graft copolymer (b-3) An enlarged reaction vessel containing an enlarged latex containing 69 parts of polymer solid content of the enlarged rubber-like copolymer (R-1). 62.8 parts of deionized water, 0.138 part of sodium formaldehyde sulfoxylate, and 0.34 part of sodium N-lauroyl sarcosinate, the internal temperature is raised to 75 ° C. Polymerized with continuous addition over a minute.
(Raw material combination)
Methyl methacrylate 29.8 parts Methyl acrylate 1.2 parts Normal octyl mercaptan 0.0465 parts Cumene hydroperoxide 0.11 parts

  After completion of the addition, the polymerization was continued for another 60 minutes. The conversion rate of methyl methacrylate was almost 100%. To the obtained polymer latex, 58 parts of styrenated phenol, 0.3 part of dilauryl thiopropionate and 0.4 part of triphenyl phosphite were added, and 0.25% by weight sulfuric acid was added at a temperature of 50 ° C. The mixture was agglomerated with water at a ratio of latex / water = 1/2, and further maintained at 85 ° C. for 5 minutes. The obtained slurry polymer was washed and dehydrated and dried at 65 ° C. for 36 hours to obtain a white powder of a rubber-containing graft copolymer (b-3).

  Rubber content of rubber-containing graft copolymers (b-1), (b-2) and (b-3) produced in Synthesis Examples 1 to 3, weight composition ratio of monomers, graft ratio, and acetone When the weight average molecular weight of the solute was measured, it was as follows.

Rubber-containing graft copolymer (b-1): rubber content = 65% by weight
AN / ST = 30/70
Graft ratio = 40% by weight
Weight average molecular weight (Mw) = 151,000
Rubber-containing graft copolymer (b-2): rubber content = 62.3 wt%
MMA / MA = 90/10
Graft ratio = 35% by weight
Weight average molecular weight (Mw) = 70,000
Rubber-containing graft copolymer (b-3): rubber content = 69% by weight
MMA / MA = 96/4
Weight average molecular weight (Mw) = 52,000

[Synthesis of polyester flame retardant (E)]
<Synthesis Examples 4 to 7: Production of polyester-based flame retardants (e-1) to (e-4)>
The polyester flame retardant (E) can be prepared by a known method described in Patent Document 4 (International Publication WO2006 / 057228 Pamphlet), and was prepared as follows.

  A predetermined amount of the carboxylic acid component, diol component, phosphorus compound and additives shown in Table 1 are charged into an autoclave equipped with a stirrer, a distillation column, and a pressure regulator, and the temperature is raised to 240 ° C. under pressure to perform esterification. Reaction was performed. To this esterification reaction product, germanium dioxide was added to the obtained polyester flame retardant so as to be 200 ppm in terms of germanium atoms, and the temperature was gradually increased to 265 ° C. over 60 minutes while gradually reducing the pressure. 3 hPa or less. The polycondensation reaction is carried out until the polyester reaches the target intrinsic viscosity while stirring under these conditions, and the polyester flame retardants (e-1) to (e) having the intrinsic viscosity shown in Table 1 and the phosphorus atom content shown in Table 1. -4) was obtained.

The phosphorus atom content and the intrinsic viscosity of the polyester flame retardant (E) were measured by the following methods.
(1) Phosphorus atom content: 7 g of a sample was weighed with a small electronic balance. Aluminum rings were arranged on the use surface (mirror surface) of the ferro plate, and a weighed sample was put therein. The ferro plate on which the sample was placed was placed in a hot air dryer at 270 ° C. and heat-treated for 20 minutes. After cooling, the molten sample was peeled off from the ferro plate together with the aluminum ring to obtain a plate-like sample having a thickness of about 5 mm. The non-contact side of the ferro plate of the plate-like sample was subjected to fluorescent X-ray analysis using a fluorescent X-ray analyzer system 3270 manufactured by Rigaku Corporation to determine the phosphorus atom content.
(2) Intrinsic viscosity: measured at 30 ° C. in a phenol / 1,1,2,2-tetrachloroethane mixed solution (weight ratio (3/2)).

[Synthesis of anti-dripping agent (F)]
<Synthesis Example 8: Production of anti-dripping agent (f-1)>
150 parts of deionized water, 0.1 part of sodium carbonate, and 1.0 part of boric acid were placed in a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet, monomer addition port, and thermometer. Next, the temperature in the flask was raised to 80 ° C. while replacing with nitrogen. First, 1/25 of the following mixture (1) was added, and then 0.075 part of potassium persulfate (KPS) was added as a polymerization initiator. For 30 minutes, and then 0.5 parts of sodium hypophosphite was added. Thereafter, the remainder of the mixture (1) was added over 2 hours, and maintained for 1 hour while being kept at 80 ° C. to complete the polymerization, thereby obtaining an emulsified MMA / MA copolymer (solid content: 40% by weight).

[Combination of mixture (1)]
Methyl methacrylate 94.0 parts Methyl acrylate 6.0 parts Octyl mercaptan 0.3 parts Emulsifier A * 0.9 parts (* Polyoxyethylene alkyl ether phosphate ester (trade name: Phosphanol RS-610NA, Toho) Chemical Co., Ltd.)

  Next, this emulsified MMA / MA copolymer and emulsified polytetrafluoroethylene (“FLUON AD1” manufactured by Asahi Glass Co., Ltd., 60 wt% solid content, number average molecular weight of 3 million) are 50:50 in terms of solid content. And heated to 60 ° C. with sufficient stirring. Thereafter, a 1.6 wt% calcium acetate aqueous solution was gradually added and solidified while stirring, and the resulting solid was dehydrated and dried to obtain an anti-dripping agent (f-1).

[Production and evaluation of flame retardant polylactic acid-based thermoplastic resin composition pellets]
It is difficult to mix the above components at the blending ratios shown in Tables 2 to 4, melt and mix at 200 to 240 ° C. with a twin screw extruder (“TEX-30α” manufactured by Nippon Steel), and pelletize. A pellet of a flame-retardant polylactic acid-based thermoplastic resin composition was produced.

These resin pellets were molded at 220 to 250 ° C. with a 2 ounce injection molding machine (manufactured by Toshiba Corporation), and impact resistance (Charpy impact strength) and heat resistance (load deflection temperature) were measured by the following methods. .
Charpy impact strength (KJ / m): ISO 179 (normal temperature)
Deflection temperature under load (° C): ISO 75 (measurement load 0.45 MPa)
In addition, regarding combustibility, a 2 ounce injection molding machine (manufactured by Toshiba Corporation) was molded at 220 to 250 ° C. to prepare 1.0 mm and 1.5 mm thickness test pieces, and combustion according to UL94. A test was conducted to check the flammability.

In addition, the following durability and compound properties were evaluated.
Durability: For molded products that have been subjected to accelerated tests under the following conditions in a programmed constant temperature and humidity chamber
Then, the impact resistance is measured by the above method, and the Charpy impact before the accelerated test
The strength retention was determined and evaluated according to the following criteria.
<Promotion conditions>
Temperature = 80 ° C
Humidity = 80% RH
Time = 100 hours
<Evaluation criteria>
○: Charpy impact strength retention 80% or more
Δ: Charpy impact strength retention 60% or more and less than 80%
X: Charpy impact strength retention rate of less than 60% Compounding property: The state of the strands during the production of the resin pellets was confirmed visually, and the following
Evaluated by criteria.
<Evaluation criteria>
◎: Stable production without strand breakage
○: Strands may break but stable production is possible
Δ: Strand sometimes breaks, slightly unstable, but practical level
×: Strand is broken and stable production is not possible
It was determined.

[Examples and Comparative Examples]
In Tables 2-4, the result of Examples 1-21 and Comparative Examples 1-9 was shown.

[Discussion]
As is apparent from Tables 2 to 4, the flame retardant polylactic acid-based thermoplastic resin composition of Examples 1 to 21 that satisfies the requirements of the present invention contains a polylactic acid resin content of 25% by weight or more, and is practical. Excellent mechanical strength such as impact strength, heat resistance, flame retardancy, especially flame resistance, durability and compounding properties in thin wall, especially balance of impact resistance, heat resistance, flame retardancy Is excellent.
On the other hand, the polylactic acid resin alone of Comparative Example 1 has low impact resistance and other characteristics are poor. Even in the case of adding an aromatic polycarbonate-based resin, Comparative Example 2 which does not contain a rubber-reinforced resin or a polyester-based flame retardant has low heat resistance and insufficient flame retardancy. Although the comparative example 3 does not contain a polyester flame retardant, the flame retardancy is relatively good, but the polylactic acid resin content in the composition is 25% by weight or less, which is outside the scope of the present invention. In Comparative Examples 4 to 6 containing no polyester flame retardant, impact resistance and heat resistance are low, and flame retardancy is not sufficient. In Comparative Example 7 containing no phosphorus-based flame retardant, the impact resistance is low and the flame retardancy is not sufficient. In Comparative Example 8 in which the phosphorus concentration of the polyester flame retardant is low, the flame retardancy is not sufficient. In Comparative Example 9 containing a large amount of hydrolysis inhibitor, the impact resistance is low and the flame retardancy is not sufficient.
As mentioned above, the resin composition of Comparative Examples 1-9 is inferior to the physical property balance of a resin composition compared with Examples 1-21, and cannot satisfy | fill the electrical / electronic-related required characteristic also about a flame retardance.

The molded product formed by molding the flame retardant polylactic acid-based thermoplastic resin composition of the present invention has excellent mechanical strength such as impact resistance, flame retardancy, and heat resistance, and is particularly excellent in heat resistance. The molding cycle can be shortened, the moldability is excellent, and the secondary decoration and secondary workability such as painting and vapor deposition are also excellent. In addition, the flame-retardant properties of thin-walled molded products are good, and the appearance is also excellent. For example, in applications related to electricity and electronics, notebook computers, mobile phones, printers, televisions, audio, etc. It can be used for various applications such as OA equipment and exterior materials for home appliances in accordance with market needs, and its industrial usefulness is very high, and it is also effective for reducing environmental load.
In addition, the content of polylactic acid resin in the composition can be 25% by weight or more. Consideration for the environment aimed at adapting to the biomass plastic identification and labeling system operated by the Japan Bioplastics Association and obtaining the biomass plastic mark. Is effective in preventing global warming and reducing fossil resource consumption.

Claims (4)

25 to 67 parts by weight of polylactic acid resin (A),
3 to 45 parts by weight of rubber reinforced resin (B),
30 to 72 parts by weight of the aromatic polycarbonate resin (C) is included so that the total amount is 100 parts by weight,
Furthermore, with respect to a total of 100 parts by weight of the polylactic acid resin (A), the rubber-reinforced resin (B), and the aromatic polycarbonate resin (C),
3 to 30 parts by weight of a phosphorus-based flame retardant (D),
The copolymerizable component to dicarboxylic acid component comprising molecules cyclic phosphorus compound represented by the following formula (1), the phosphorus atom content 4% by weight or more of polyester-based flame retardant (E) and 1 to 15 parts by weight,
0.1-8 parts by weight of anti-dripping agent (F),
Flame retardant auxiliary material (G) 0.1-20 parts by weight, which are inorganic particles having an average particle size of 0.5-15 μm;
A flame retardant polylactic acid-based thermoplastic resin composition comprising 1 to 5 parts by weight of a hydrolysis inhibitor (H).

Rubber-reinforced resin (B), flame retardant polylactic acid thermoplastic resin composition according to claim 1, characterized in that it comprises a rubber-containing graft copolymer. Anti-dripping agent (F) is a mixture of methacrylic acid ester polymer or methacrylic acid ester co-polymer and a fluorine-based acrylic acid ester (co) polymer, or a fluorine-based (co) polymer and methacrylic acid flame retardant polylactic acid thermoplastic resin composition according to claim 1 or 2, characterized in that a copolymer of esters or methacrylic acid esters and acrylic acid esters.   A molded product obtained by molding the flame-retardant polylactic acid-based thermoplastic resin composition according to any one of claims 1 to 3.