JP5703838B2 - Flame retardant composite polylactic acid-based thermoplastic resin composition and molded article thereof - Google Patents

Description

  The present invention improves the flame retardancy of a polylactic acid-based thermoplastic resin composition, improves the physical properties such as heat resistance, impact strength, and elastic modulus in a well-balanced manner, and expands the product application range of molded products. The present invention relates to a polylactic acid-based thermoplastic resin composition. Moreover, this invention relates to the molded article formed by shape | molding this flame-retardant composite polylactic acid-type thermoplastic resin composition.

  Recently, an increase in the concentration of carbon dioxide in the atmosphere has been pointed out as a cause of global warming, and the need for regulation of carbon dioxide emissions on a global scale has been advocated. Carbon dioxide emission sources include respiration of organisms, rot and fermentation by bacteria, etc., but it is largely due to combustion, and the current phenomenon of rising carbon dioxide concentration in the atmosphere wasted oil resources after the industrial revolution by humans It is no exaggeration to say that it was brought about by economic activities.

  By the way, in recent years, effective utilization of plant resources that absorb and fix carbon dioxide has attracted attention as carbon neutral. In other words, vegetation is intended to absorb carbon dioxide while replacing petroleum resources that are expected to be depleted in the future.

  In the field of plastics, biomass-based plastics were developed from those based on conventional petroleum as a basic raw material. At first, they attracted attention as biodegradable resins, but recently their significance has been reviewed as plant-based plastics. ing.

Among these biodegradable resins, polylactic acid resin (PLA) has been expected to be put into practical use because of its physical properties and possibility of mass production. However, polylactic acid resin is mechanical compared to existing petroleum plastics. There is a drawback that it is inferior in strength, particularly impact strength, and its improvement has been desired from an early stage.
In addition, since the polylactic acid resin burns very well as compared with other resins such as a polyester-based resin, there is a problem that it is very difficult to make it flame retardant.

  In general, in order to improve the impact strength strength of plastics, a method of blending a rubbery polymer has been performed, and similar efforts have been made for polylactic acid resins.

  For example, in Patent Document 1 “JP 9-316310 A” and Patent Document 2 “JP 2001-123055”, a method of adding a modified olefin compound is disclosed in Patent Document 3 “JP 11 140292 A1”. ”Shows a method of blending a cross-linked polycarbonate, but none of them can be said to have a sufficient effect of improving physical properties as compared with existing general-purpose plastics.

  Patent Document 4 “Japanese Patent Laid-Open No. 2002-37987” shows the blending of a graft polymer (AES resin) to ethylene-propylene-diene rubber (EPDM), but the impact strength indicated by Izod impact strength. The improvement effect is not sufficient.

  Patent Document 5 “Japanese Patent Application Laid-Open No. 2003-286396” shows a blending effect of a graft polymer as a multilayer structure polymer. Here, the outermost layer of the multilayer polymer is defined as a polymer containing an unsaturated carboxylic acid alkyl ester-based unit. Specifically, a polymer grafted to a rubbery polymer such as methyl methacrylate is suggested. ing. In this technique, the reforming effect is certainly highly evaluated, but since these modifiers are all expensive, they are not suitable for industrial production.

  On the other hand, in Patent Document 6 “Japanese Patent Laid-Open No. 2006-137908” and Patent Document 7 “Japanese Patent Laid-Open No. 2006-161024”, a rubber-containing graft copolymer and a hard copolymer are added to a polylactic acid resin. Polylactic acid-based thermoplastic resin compositions with improved impact resistance, heat resistance, etc. have been proposed, but further improvement in the physical property balance is expected from the market.

  Regarding the improvement of flame retardancy, Patent Document 8 “Japanese Unexamined Patent Application Publication No. 2007-146087” describes a specific amount of a polyester resin typified by a polycarbonate resin and a flame retardant to impart flame retardancy to a polylactic acid resin. A flame retardant polylactic acid-based thermoplastic resin composition blended with the above has been proposed. However, market needs require thin walls and high rigidity, and further functional improvements are required.

  Patent Document 9 “Japanese Unexamined Patent Application Publication No. 2009-91453” proposes a resin composition in which organic fibers such as polyester fibers are blended with polylactic acid for the purpose of improving impact resistance and heat resistance. There is no mention of flammability and physical property balance.

JP 9-316310 A JP 2001-123055 A JP-A-11-140292 JP 2002-37987 A JP 2003-286396 A JP 2006-137908 A JP 2006-161024 A JP 2007-146087 A JP 2009-91453 A

  The present invention solves the above-described problems in the prior art and greatly improves the flame retardancy of a polylactic acid-based thermoplastic resin composition that has inherently high flammability, as well as heat resistance, impact strength, elastic modulus, and the like. A flame retardant composite polylactic acid-based thermoplastic resin composition that improves the physical properties of the product in a well-balanced manner and expands the product application range of molded products, and a molded product formed by molding this flame-retardant composite polylactic acid-based thermoplastic resin composition The purpose is to do.

As a result of diligent efforts to verify and improve the conventional technology, the inventors have added a specific amount of an aromatic polycarbonate resin, a flame retardant, and polyethylene naphthalate fiber to a polylactic acid thermoplastic resin composition having a specific composition. Can greatly improve the flame retardancy and improve the physical properties such as heat resistance, impact strength, elastic modulus, etc. in a well-balanced manner. It has also been found that a good molded product appearance that can withstand practical use is exhibited in molding.
The present invention has been achieved on the basis of such findings, and the gist of the present invention is from 10 to 95% by weight of the polylactic acid resin (A) and 90 to 5% by weight of the rubber-containing styrenic resin (B). An aromatic polycarbonate resin (C) 50 to 200 parts by weight, a flame retardant 1 to 50 parts by weight (D), and a polyethylene naphthalate fiber (E) 1 to 50 parts by weight with respect to 100 parts by weight of the resulting polylactic acid-based thermoplastic resin component Is a flame retardant composite polylactic acid-based thermoplastic resin composition, wherein the polyethylene naphthalate fiber (E) does not carry a phosphorus element or is 3.0% by weight with respect to the fiber weight. % or less of phosphorus element and is supported, and the polyethylene naphthalate fiber (E), the flame retardant composite poly, characterized in der Rukoto those surface-treated with a surface treatment agent containing polyurethane resin A lactic acid thermoplastic resin composition.

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

The flame retardant composite polylactic acid-based thermoplastic resin composition of the present invention has a high degree of flame retardancy and excellent physical property balance such as heat resistance, impact resistance strength, elastic modulus, etc. Can be spread. In particular, the flame-retardant composite polylactic acid-based thermoplastic resin composition of the present invention is highly advanced in thin-walled and high-rigidity materials for the purpose of reducing the weight of products in recent various fields due to its excellent flame retardancy and physical property balance. It is a material suitable for various casings and structural members of electrical, electronic, and OA equipment that require flame retardancy.
Although the details of the reason why the flame-retardant composite polylactic acid-based thermoplastic resin composition of the present invention can exhibit a high level of flame retardancy are not clear, in the composition region of the specific formulation in the present invention, a uniform char at the time of combustion. (Carbonized layer) can be formed, and it is presumed that flammable gas from polylactic acid can be contained while blocking oxygen.

  According to the present invention, by providing such a practical flame retardant composite polylactic acid-based thermoplastic resin composition, the use of polylactic acid resin, which is a plant-based resin, is further expanded, and the idea of carbon neutral is put into practice. Further promotion can contribute to the reduction of the global environmental load.

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

  In the present specification, “(co) polymerization” is a general term for “polymerization” and “copolymerization”. “(Meth) acrylic acid” means “acrylic acid and / or methacrylic acid”.

  The flame-retardant composite polylactic acid-based thermoplastic resin composition of the present invention comprises a polylactic acid-based thermoplastic resin comprising 10 to 95% by weight of a polylactic acid resin (A) and 90 to 5% by weight of a rubber-containing styrene-based resin (B). To 100 parts by weight of the component, 50 to 200 parts by weight of the aromatic polycarbonate resin (C), 1 to 50 parts by weight of the flame retardant (D) and 1 to 50 parts by weight of the polyethylene naphthalate fiber (E) are added. Features.

[Polylactic acid thermoplastic resin component]
In the present invention, the polylactic acid thermoplastic resin component is composed of 10 to 95% by weight of the polylactic acid resin (A) and 90 to 5% by weight of the rubber-containing styrene resin (B).

<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 -Glycol compounds such as diol, neopentyl glycol, glycerin, pentaerythritol, bisphenol A, polyethylene glycol, polypropylene glycol, polytetramethylene glycol; 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) is not particularly limited as long as it can be practically processed, but the weight average molecular weight is usually 10,000 or more, preferably 50,000 or more, Furthermore, it is desirable that it is 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 polylactic acid is in the form of pellets, 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 polylactic acid-based thermoplastic resin component is in the range of 10 to 95% by weight, preferably 30 to 95% by weight, more preferably 50 to 90% by weight. % Is preferable from the viewpoint of carbon neutral and improvement of physical property balance. When the blending amount of the polylactic acid resin (A) is not less than the above lower limit value, the object of the present invention for effectively using the polylactic acid resin can be achieved, and the physical property balance is excellent by being not more than the above upper limit value. A molded product is 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 (A) include, for example, “Ingeo” manufactured by Nature Works, a commercially available product, “REVODE” manufactured by China Marine Biomaterials Co., Ltd. can do.

<Rubber-containing styrene resin (B)>
The rubber-containing styrenic resin (B) used in the present invention is a rubber-containing graft copolymer obtained by graft-polymerizing a hard (co) polymer to a rubbery polymer generally expressed by ABS, ASA, AES, HIPS, MBS or the like. It is a polymer.

  Here, the rubber-containing graft copolymer is obtained by graft polymerization of a monomer to a rubber polymer, and during this graft polymerization, some of the rubber-containing graft copolymer is graft polymerized to the rubber polymer. In some cases, a monomeric (co) polymer may be produced, but the graft copolymer referred to in the present invention is a graft copolymer including these. The rubber-containing styrene resin (B) used in the present invention may include a rubber-containing graft copolymer (b-1) and a hard (co) polymer (b-2).

(Rubber-containing graft copolymer (b-1))
Examples of the rubbery polymer forming the rubber-containing graft copolymer (b-1) include butadiene rubbers such as polybutadiene, styrene / butadiene copolymer, acrylate ester / butadiene copolymer, and styrene / isoprene. Conjugated diene rubbers such as copolymers; Acrylic rubbers such as polybutyl acrylate; Olefin rubbers such as ethylene / propylene copolymers; Silicon rubbers such as polyorganosiloxane, etc. Polybutadiene rubber, acrylic rubber, and olefin rubber are preferred because the cost is reasonable and the modification effect to polylactic acid is good. These rubbery polymers can be used singly or in combination of two or more.

  These rubbery polymers can be used from monomers, and the structure of the rubbery polymer may take a core / shell structure. For example, a rubbery polymer having polybutadiene as the core and acrylic acid ester as the shell can be used.

  The gel content of the rubbery polymer is usually 50 to 90% by weight, preferably 60 to 85% by weight, and more preferably 70 to 85% by weight. If the gel content is within this range, the properties of the obtained flame-retardant composite polylactic acid-based thermoplastic resin composition, particularly the impact strength, can be improved. Details of the reason why the impact resistance strength can be sufficiently improved when the gel content of the rubbery polymer is 50 to 90% by weight are not clear, but the gel content is not less than the above lower limit value. Thus, the impact energy of the rubber polymer is efficiently absorbed, and when the amount is not more than the above upper limit, a part of the vinyl monomer to be graft-polymerized is impregnated inside the rubber polymer. Thus, it is presumed that the absorption and dispersion of impact energy can be obtained. Therefore, when the gel content is in the range of 50 to 90% by weight, it is considered that the impact energy is effectively absorbed or dispersed, and the effect of improving the impact resistance is exhibited.

  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 200 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.

  For the hard (co) polymer to be graft polymerized to such a rubbery polymer, it is preferable to use a monomer mainly composed of an aromatic vinyl monomer. Specific examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, bromostyrene and the like, and styrene and α-methylstyrene are particularly preferable.

  The hard (co) polymer to be graft polymerized with the rubber polymer can be used in combination with other copolymerizable monomers having an aromatic vinyl monomer as a main component. Examples of other copolymerizable monomers include vinyl cyanide monomers, (meth) acrylic acid esters, and maleimide compounds. Examples of vinyl cyanide monomers include acrylonitrile and methacrylonitrile. It is done. Examples of (meth) acrylic acid esters include methacrylic acid esters or acrylic acid esters such as methyl methacrylate and methyl acrylate. Examples of the maleimide compound include N-phenylmaleimide, N-cyclohexylmaleimide and the like. In particular, acrylonitrile is preferably used as another copolymerizable monomer from the viewpoint of balance between heat resistance and impact resistance. In some cases, it may contain a monomer modified with a functional group. Examples of such a monomer include unsaturated carboxylic acid such as acrylic acid, methacrylic acid, itaconic acid, and fumaric acid. Can be mentioned. These can be used individually by 1 type or in mixture of 2 or more types.

  In addition, as a use ratio (weight ratio) of a monomer, it is preferable to use in the range of 100 / 0-60 / 40 as an aromatic vinyl-type monomer / other copolymerizable monomers.

  Graft polymerization can be performed 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 (b-1), two or more kinds of rubber-containing graft copolymers having different polymerization methods and component compositions may be mixed and used.

(Hard (co) polymer (b-2))
The rubber-containing styrenic resin (B) used in the present invention has a hard (co) polymer (b) added to the rubber-containing graft copolymer (b-1) for improving properties such as heat resistance and fluidity. -2) may be blended.

  As a monomer component used for the hard (co) polymer (b-2) used in this case, the aromatic vinyl monomer introduced in the rubber-containing graft copolymer (b-1) is used. A monomer as a main component and other monomers can be used, and the preferred composition thereof is also the same.

  The weight average molecular weight of the hard copolymer (b-2) is preferably in the range of 50,000 to 300,000, more preferably in the range of 100,000 to 250,000. When the weight average molecular weight of the hard copolymer (b-2) is not less than the above lower limit value, the resulting molded article has good impact resistance, and by being not more than the above upper limit value, the moldability is improved. It becomes good.

  As for the hard (co) polymer (b-2), one kind may be used alone, or two or more kinds having different compositions and molecular weights may be mixed and used.

(Rubber content, acetone-soluble weight average molecular weight, graft ratio)
Even when the rubber-containing styrene-based resin (B) of the present invention is composed of the rubber-containing graft copolymer (b-1), the rubber-containing graft copolymer (b-1) and the hard (co) Even when the polymer (b-2) is contained, it is preferable that the following preferable rubber content, acetone-soluble weight average molecular weight and graft ratio are satisfied.

  The rubber content in the rubber-containing styrenic resin (B) is preferably adjusted to be in the range of 5 to 80% by weight, more preferably 5 to 50% by weight, and still more preferably 7 to 30% by weight. If the rubber content is lower than this range, sufficient impact resistance cannot be obtained, and if it exceeds this range, no improvement in impact strength can be expected, resulting in poor dispersibility and mechanical properties such as rigidity. There is a risk of deterioration of characteristics.

  The rubber content of the rubber-containing styrene resin (B) can be measured by using an infrared spectrometer.

  Further, the weight average molecular weight of the acetone-soluble component of the rubber-containing styrene resin (B) is preferably in the range of 50,000 to 600,000, more preferably 70,000 to 400,000, and still more preferably 100,000. It is in the range of ~ 250,000. When the weight-average molecular weight of acetone-soluble component is lower than this range, the resulting polylactic acid-based thermoplastic resin molded article has insufficient impact resistance, and when it exceeds this range, polylactic acid-based thermoplasticity The moldability of the resin composition is reduced.

  The graft ratio ((acetone insoluble matter weight / rubber polymer weight-1) × 100) of the rubber-containing styrenic resin (B) is preferably 15 to 150% by weight. When the graft ratio of the rubber-containing styrenic resin (B) is lower than 15% by weight, the dispersibility of the rubbery polymer is lowered and the impact strength is lowered. On the other hand, when the graft ratio is higher than 150% by weight, impact strength and formability tend to be lowered. The (co) polymer graft-polymerized to the rubber polymer may have a structure occluded not only inside but also inside the rubber polymer.

  The ratio of the rubber-containing graft copolymer (b-1) and the hard (co) polymer (b-2) in the rubber-containing styrenic resin (B) is the above-mentioned preferable rubber content, acetone-soluble Rubber-containing styrene, which is arbitrary within the range satisfying the weight average molecular weight and the graft ratio, but is usually the sum of the rubber-containing graft copolymer (b-1) and the hard (co) polymer (b-2) The rubber-containing graft copolymer (b-1) is preferably 10 to 100% by weight, particularly 15 to 50% by weight in the resin (B).

  These rubber-containing styrenic resins (B) may be blended with resin recovered from the market or the like, or resin waste generated in the production or molding process.

  In the present invention, the blending amount of the rubber-containing styrene resin (B) in the polylactic acid thermoplastic resin component is in the range of 5 to 90% by weight, preferably 5 to 70% by weight, more preferably 10 to 10%. 50% by weight is preferable from the viewpoint of carbon neutral and improvement of physical property balance. When the blending amount of the rubber-containing styrenic resin (B) is not more than the above upper limit, the object of the present invention for effectively using the polylactic acid resin can be achieved without reducing the blending amount of the polylactic acid resin (A). When the amount is at least the above lower limit, a molded product having excellent physical property balance can be obtained.

<Aromatic polycarbonate resin (C)>
The aromatic polycarbonate resin (C) used in the present invention preferably has a viscosity average molecular weight of 12,000 to 30,000 as determined by the solution viscosity method, and one or more bisphenols and phosgene or It can be produced by reaction with a carbonic acid diester. Moreover, when a chlorine atom and a bromine atom are contained in the molecular structure, the flame retardancy of the aromatic polycarbonate resin itself is improved. However, since compatibility with other resins deteriorates, it is preferable not to contain them. It can be confirmed by an analyzer such as a fluorescent X-ray analyzer that the aromatic polycarbonate resin (C) does not contain a chlorine atom or a bromine atom.

  Specific examples of bisphenols used in the production of the aromatic polycarbonate resin (C) include hydroquinone, 4,4-dihydroxyphenyl, bis- (4-hydroxyphenyl) -alkane, and bis- (4-hydroxyphenyl) -cycloalkane. Bis- (4-hydroxyphenyl) -sulfide, bis- (4-hydroxyphenyl) -ether, bis- (4-hydroxyphenyl) -ketone, bis- (4-hydroxyphenyl) -sulfone, or alkyl substitution thereof , Aryl-substituted, halogen-substituted, etc., and these can be used alone or in combination of two or more.

  As the aromatic polycarbonate resin (C), a so-called bisphenol A-based polycarbonate resin using 2,2-bis- (4-hydroxyphenyl) propane as a bisphenol is preferable because it can be easily obtained on the market. As a commercial item of such aromatic polycarbonate resin (C), for example, manufactured by Teijin Chemicals Ltd .: “Panlite L-1225L” (viscosity average molecular weight = 15,000), manufactured by Mitsubishi Engineering Plastics Co., Ltd. : “Iupilon E-2000” (viscosity average molecular weight = 25,000) and the like.

  The aromatic polycarbonate resin (C) used in the present invention is a recovered aromatic recovered by removing a metal reflective film or a coating film from an optical disk such as a commercially available music CD, game CD, MD, MO, DVD, etc. Polycarbonate resin may be used, and by using such recovered aromatic polycarbonate resin, it is only possible to recycle used optical discs and defective optical discs to further reduce the environmental burden. In addition, by using a polycarbonate resin having a molecular weight used for such an optical disk, the melt mixing property between the polylactic acid resin (A) and the rubber-containing styrene resin (B) is improved, and the polylactic acid thermoplastic resin is obtained. The composition can be imparted with an excellent balance of physical properties and a molded product surface appearance.

  The optical disk to be processed here is a so-called defective, returned, recovered, or used optical disk that is generated from any route from the production of the optical disk whose substrate is made of aromatic polycarbonate resin to after sales. This is an optical disc.

  Specifically, the optical disk includes a ROM disk such as a compact disk, a mini disk, and a laser disk for a reproduction-only type, and a DRAM disk such as a CD-R and a write-once disk for a recording and reproduction type. In the rewritable type, there are E-DRAW optical disks such as a magneto-optical disk and a phase change optical disk. These optical discs include a single-sided storage type and a two-sheet bonding type for DVD.

  To recover the aromatic polycarbonate resin from such an optical disc, the metal reflective film or coating film is removed from the optical disc by a chemical treatment method such as acid or alkali treatment, or a mechanical treatment method such as sandblasting. Then, the resin may be recovered according to a conventional method.

  The molecular weight of the recovered aromatic polycarbonate resin thus obtained is preferably 12,000 to 18,000 in terms of viscosity average molecular weight.

In the present invention, the viscosity average molecular weight is a value obtained by inserting a specific viscosity [ηsp] obtained from a solution obtained by dissolving 0.7 g of an aromatic polycarbonate resin in 100 ml of methylene chloride at 20 ° C. into the following equation. (Where [η] is the intrinsic viscosity and M is the viscosity average molecular weight).
[Ηsp] / c = [η] + 0.45 × [η] 2c
[Η] = 1.23 × 10 ⁴ × M ^0.83
c = 0.7 (concentration)
One of these aromatic polycarbonate resins (C) may be used alone, or two or more of them having different reaction raw materials or molecular weights may be used in combination. Also, a new resin and a recovered resin may be mixed and used.

  In this invention, the compounding quantity of aromatic polycarbonate resin (C) is 50-200 weight part with respect to 100 weight part of polylactic acid-type thermoplastic resin components, Preferably it is 80-150 weight part, More preferably, it is 90-120. Parts by weight. When the blending amount of the aromatic polycarbonate resin (C) is not less than the above lower limit value, the effect of improving the balance of physical properties such as flame retardancy, impact resistance and heat resistance can be sufficiently obtained. If the above upper limit is exceeded, the balance of physical properties such as combustibility, impact resistance, and heat resistance will be significantly deteriorated.

<Flame retardant (D)>
The flame retardant (D) used in the present invention is not particularly limited as long as it is a substance added for the purpose of imparting flame retardancy to the resin. Specifically, brominated flame retardants, phosphorus-based flame retardants are used. Examples include flame retardants, nitrogen compound flame retardants, silicone flame retardants, and other inorganic flame retardants. One or more of these can be selected and used.

  Specific examples of the brominated flame retardant used in the present invention include decabromodiphenyl oxide, octabromodiphenyl oxide, tetrabromodiphenyl oxide, tetrabromophthalic anhydride, hexabromocyclododecane, bis (2,4,6-tribromo). Phenoxy) ethane, ethylenebistetrabromophthalimide, hexabromobenzene, 1,1-sulfonyl [3,5-dibromo-4- (2,3-dibromopropoxy)] benzene, polydibromophenylene oxide, tetrabromobisphenol-S, Tris (2,3-dibromopropyl-1) isocyanurate, tribromophenol, tribromophenyl allyl ether, tribromoneopentyl alcohol, brominated polystyrene, brominated polyethylene, tetrabromobis Enol-A, tetrabromobisphenol-A derivative, tetrabromobisphenol-A-epoxy oligomer or polymer, tetrabromobisphenol-A-carbonate oligomer or polymer, brominated epoxy resin such as brominated phenol novolac epoxy, tetrabromobisphenol-A -Bis (2-hydroxydiethyl ether), tetrabromobisphenol-A-bis (2,3-dibromopropyl ether), tetrabromobisphenol-A-bis (allyl ether), tetrabromocyclooctane, ethylenebispentabromodiphenyl, Tris (tribromoneopentyl) phosphate, poly (pentabromobenzylpolyacrylate), octabromotrimethylphenylindane, dibromoneope Chill glycol, pentabromobenzyl polyacrylate, dibromo cresyl glycidyl ether, N, N'ethylene - bis - such as tetrabromo phthalic imide. Of these, tetrabromobisphenol-A-epoxy oligomer, tetrabromobisphenol-A-carbonate oligomer, and brominated epoxy resin are preferable.

  The phosphorus-based flame retardant used in the present invention is not particularly limited, and a generally used phosphorus-based flame retardant can be used. Typically, an organic phosphorus compound such as a phosphate ester or a polyphosphate, Red phosphorus is mentioned.

  Specific examples of the phosphoric acid ester in the above organic phosphorus compounds include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl. Phosphate, tris (isopropylphenyl) phosphate, tris (phenylphenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, di (isopropylphenyl) phenyl phosphate, monoisodecyl Phosphate, 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acetate Phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, triphenylphosphine oxide, tricresylphosphine oxide, diphenyl methanephosphonate, phenylphosphonic acid Examples include condensed phosphate esters such as diethyl, resorcinol polyphenyl phosphate, resorcinol poly (di-2,6-xylyl) phosphate, bisphenol A polycresyl phosphate, hydroquinone poly (2,6-xylyl) phosphate, and condensates thereof. be able to. Examples of commercially available condensed phosphate ester flame retardants include PX-200, PX-201, PX-202, CR-733S, CR-741, and CR747 manufactured by Daihachi Chemical Co., Ltd.

  Examples of the organic phosphorus compounds include phosphates and polyphosphates composed of salts of phosphoric acid, polyphosphoric acid and metals of groups IA to IVB of the periodic table, ammonia, aliphatic amines, and aromatic amines. You can also. As typical salts of polyphosphates, lithium salts, sodium salts, calcium salts, barium salts, iron (II) salts, iron (III) salts, aluminum salts, etc. as metal salts, methylamine salts as aliphatic amine salts, Examples include ethylamine salt, diethylamine salt, triethylamine salt, ethylenediamine salt, piperazine salt and the like.

  In addition to the above, halogen-containing phosphate esters such as trischloroethyl phosphate, trisdichloropropyl phosphate, tris (β-chloropropyl) phosphate), and a structure in which a phosphorus atom and a nitrogen atom are connected by a double bond. Examples thereof include phosphazene compounds and phosphoric ester amides.

  Further, as red phosphorus, not only untreated red phosphorus but also red phosphorus treated with one or more compound films selected from the group consisting of thermosetting resin coatings, metal hydroxide coatings, and metal plating coatings. It can be preferably used. The thermosetting resin of the thermosetting resin film is not particularly limited as long as it is a resin capable of coating red phosphorus. For example, phenol-formalin resin, urea-formalin resin, melamine-formalin resin, alkyd resin Etc. The metal hydroxide coating is not particularly limited as long as it can coat red phosphorus, and examples thereof include aluminum hydroxide, magnesium hydroxide, zinc hydroxide, and titanium hydroxide. . The metal of the metal plating film is not particularly limited as long as it can coat red phosphorus, and examples thereof include Fe, Ni, Co, Cu, Zn, Mn, Ti, Zr, Al, and alloys thereof. Furthermore, these coatings may be laminated in combination of two or more or in combination of two or more.

  Examples of the nitrogen compound-based flame retardant used in the present invention include aliphatic amine compounds, aromatic amine compounds, nitrogen-containing heterocyclic compounds, cyanide compounds, aliphatic amides, aromatic amides, urea, thiourea and the like. . In addition, nitrogen-containing phosphorus flame retardants such as ammonium polyphosphate as exemplified in the above phosphorus flame retardant are not included in the nitrogen compound flame retardant referred to herein. Examples of the aliphatic amine compound include ethylamine, butylamine, diethylamine, ethylenediamine, butylenediamine, triethylenetetramine, 1,2-diaminocyclohexane, 1,2-diaminocyclooctane and the like. Examples of the aromatic amine compound include aniline and phenylenediamine. Examples of nitrogen-containing heterocyclic compounds include uric acid, adenine, guanine, 2,6-diaminopurine, 2,4,6-triaminopyridine, and triazine compounds. Examples of the cyan compound include dicyandiamide. Examples of the aliphatic amide include N, N-dimethylacetamide. Examples of aromatic amides include N, N-diphenylacetamide.

  The triazine compounds exemplified above are nitrogen-containing heterocyclic compounds having a triazine skeleton, and are triazine, melamine, benzoguanamine, methylguanamine, cyanuric acid, melamine cyanurate, melamine isocyanurate, trimethyltriazine, triphenyltriazine, amelin, and amelide. And thiocyanuric acid, diaminomercaptotriazine, diaminomethyltriazine, diaminophenyltriazine, diaminoisopropoxytriazine and the like.

  As melamine cyanurate or melamine isocyanurate, an addition product of cyanuric acid or isocyanuric acid and a triazine compound is preferable, usually an addition having a composition of 1 to 1 (molar ratio) and optionally 1 to 2 (molar ratio). You can list things. This is produced by a known method. For example, a mixture of melamine and cyanuric acid or isocyanuric acid is made into a water slurry and mixed well to form a salt of both, and then the slurry is filtered. After drying, it is generally obtained in powder form. The salt does not need to be completely pure, and some unreacted melamine, cyanuric acid or isocyanuric acid may remain. Moreover, the average particle diameter before blending with the resin is preferably 100 to 0.01 μm, more preferably 80 to 1 μm from the viewpoint of flame retardancy, mechanical strength, and surface property of the molded product.

  Of the nitrogen compound-based flame retardants, nitrogen-containing heterocyclic compounds are preferable, among which triazine compounds are preferable, and melamine cyanurate is more preferable. When the dispersibility of the nitrogen compound flame retardant is poor, a dispersant such as tris (β-hydroxyethyl) isocyanurate or a known surface treatment agent such as polyvinyl alcohol or metal oxide may be used in combination. Good.

Examples of the silicone flame retardant used in the present invention include silicone resins and silicone oils.
Examples of the silicone resin include a resin having a three-dimensional network structure formed by combining structural units of SiO ₂ , RSiO _3/2 , R ₂ SiO, and R ₃ SiO _1/2 . Here, R represents an alkyl group such as a methyl group, an ethyl group or a propyl group, an aromatic group such as a phenyl group or a benzyl group, or a substituent containing a vinyl group in the above substituent.

  In the silicone oil, polydimethylsiloxane, and at least one methyl group in the side chain or terminal of polydimethylsiloxane is a hydrogen atom, an alkyl group, a cyclohexyl group, a phenyl group, a benzyl group, an amino group, an epoxy group, or a polyether group. Modified polysiloxane modified with at least one group selected from carboxyl group, mercapto group, chloroalkyl group, alkyl higher alcohol ester group, alcohol group, aralkyl group, vinyl group, and trifluoromethyl group, or a mixture thereof Can be mentioned. Furthermore, a resin obtained by copolymerizing an aromatic polycarbonate resin with a silicone compound such as a silicone resin or polydimethylsiloxane may be used.

  Other inorganic flame retardants used in the present invention include magnesium hydroxide, aluminum hydroxide, antimony trioxide, antimony pentoxide, sodium antimonate, zinc hydroxystannate, zinc stannate, metastannic acid, tin oxide, sulfuric acid Zinc, zinc oxide, ferrous oxide, ferric oxide, stannous oxide, zinc borate, calcium borate, ammonium borate, ammonium octamolybdate, metal salt of tungstic acid, composite oxidation of tungsten and metalloid Products, ammonium sulfamate, graphite, swellable graphite, and the like. Of these, aluminum hydroxide, zinc borate, and swellable graphite are preferable.

Among the flame retardants (D), at least one or two or more selected from phosphorus-based flame retardants containing no halogen, nitrogen compound-based flame retardants, silicone-based flame retardants and other inorganic flame retardants. It is preferable to use in combination.
When two or more flame retardants are used in combination, it is preferable to use a phosphorus-based flame retardant together with another flame retardant. The nitrogen compound-based flame retardant used in combination with the phosphorus-based flame retardant is preferably a nitrogen-containing heterocyclic compound, more preferably a triazine compound, and further preferably melamine cyanurate. The silicone flame retardant used in combination with the phosphorus flame retardant is preferably an aromatic polycarbonate resin copolymerized with a silicone compound such as silicone resin or polydimethylsiloxane. Moreover, as other inorganic flame retardants used in combination with phosphorus flame retardants, aluminum hydroxide, zinc borate and swellable graphite are preferable. Moreover, when using together a phosphorus flame retardant and another flame retardant, the mixing ratio of a phosphorus flame retardant and another flame retardant is arbitrary, but especially a phosphorus flame retardant in 100% by weight of the flame retardant (D). The amount is preferably 5% by weight or more, more preferably 5 to 95% by weight.

  The compounding quantity of a flame retardant (D) is 1-50 weight part with respect to 100 weight part of polylactic acid-type thermoplastic resin components, Preferably it is 3-40 weight part. When the blending amount of the flame retardant (D) is not less than the above lower limit, the effect of imparting flame retardancy is sufficient, and when it is not more than the above upper limit, the physical property balance and the appearance of the molded product can be maintained.

<Polyethylene naphthalate fiber (E)>
In the present invention, the polyethylene naphthalate fiber (E) is blended for the purpose of improving the crystallization speed of the flame-retardant composite polylactic acid-based thermoplastic resin composition, improving physical properties such as rigidity, and improving flame retardancy. Here, it is important to use polyethylene naphthalate fiber instead of polyethylene terephthalate fiber, which is a general-purpose polyester fiber, in order to obtain the effects of the present invention, high strength and high modulus, and excellent heat resistance and dimensional stability. By blending the polyethylene naphthalate fiber with the polylactic acid-based thermoplastic resin component, a good blending effect can be obtained.

The polyethylene naphthalate fiber (E) used in the present invention has a fiber length of 0.5 to 10 mm, preferably 1.0 to 8 mm, and a fiber diameter of 10 to 50 μm, preferably 15 to 30 μm. In the invention, by using the polyethylene naphthalate fiber (E) having such a specific fiber length and fiber diameter, the molding cycle is shortened by improving the crystallization speed, and the fibers are uniformly dispersed in the resin composition. Thus, the effect of improving the balance of physical properties such as good heat resistance, impact strength and elastic modulus can be obtained.
If the fiber length of the polyethylene naphthalate fiber is less than the above lower limit, impact resistance and rigidity tend to decrease.If the fiber length exceeds the above upper limit, dispersion of fibers in the resin composition becomes non-uniform, and impact resistance and rigidity are low. It tends to decrease, and the appearance of the molded product also tends to be inferior. In addition, when the fiber diameter of the polyethylene naphthalate fiber is less than the above lower limit, the appearance of the molded product is good, but physical properties such as heat resistance, impact resistance, and rigidity tend to decrease overall, and when the upper limit is exceeded. The crystallization rate is slow, the molding cycle is lengthened, and the impact resistance and the appearance of the molded product are also deteriorated.

  In the present invention, the fiber length and fiber diameter of the polyethylene naphthalate fiber (E) are fibers measured by microscopic observation of 50 to 100 polyethylene naphthalate fibers before mixing with the polylactic acid-based thermoplastic resin component. Although it is the average value of length and fiber diameter, when using commercially available polyethylene naphthalate fiber, the catalog value can be adopted. The same conditions as above are applied to the polyethylene naphthalate fibers present in the molded article of the present invention.

  The polyethylene naphthalate fiber (E) may be synthesized from a fossil-derived resource such as a conventional naphtha, or may be a bio fiber synthesized from a plant raw material existing on the earth. If it is a bio-fiber system, it will lead to further reduction of the global environmental load through the use of recyclable resources as well as carbon dioxide reduction.

  Examples of commercially available polyethylene naphthalate fibers (E) that satisfy the above conditions include polyethylene naphthalate fibers provided by Teijin Fibers Ltd. under the trade name “Teonex”, but are limited to specific products. It is not a thing.

  The polyethylene naphthalate fiber (E) used in the present invention preferably supports a phosphorus element. Since the phosphorus element is supported on the polyethylene naphthalate fiber (E), the effect of improving the flame retardancy by blending the polyethylene naphthalate fiber (E) is further enhanced.

  If the amount of the phosphorus element supported on the polyethylene naphthalate fiber (E) is too small, the effect of improving flame retardancy due to the support of the phosphorus element cannot be obtained sufficiently, but if it is excessively large, the polyethylene naphthalate fiber (E ) And the resin component are hindered and the mechanical properties of the flame-retardant composite polylactic acid-based thermoplastic resin composition are reduced, so that the amount of phosphorus element supported is polyethylene naphthalate fiber (E ) Of 3.0% by weight or less, preferably 1.0 to 2.0% by weight.

  In particular, the phosphorus element is preferably obtained by treating the polyethylene naphthalate fiber with the above-described phosphorus-based flame retardant, in particular, a phosphate ester compound, thereby attaching the phosphate ester compound to the polyethylene naphthalate fiber, As this phosphoric acid ester compound, those represented by the following general formula (I) are preferably used.

(However, R ^{1 to} R ³ are each independently an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a phenyl group, a hydroxyphenyl group, a tolyl group, a phenoxyethyl group, an epoxy group, Represents a methylamino group, an amino group or an aralkyl group.)

  Examples of such phosphate ester compounds include trimethyl phosphate, triethyl phosphate, dibutyl methyl phosphate, ethyl diglycol phosphate, triphenyl phosphate, tricresyl phosphonate, bis [tris (2-hydroxypropoxy) propyl] penta Examples include erythritol diphosphate, dialkyldiethanolaminoalkyl phosphonate, and the like, but the present invention is not limited to these compounds. These phosphate ester compounds may be used individually by 1 type, and may use 2 or more types together.

  In order to treat the polyethylene naphthalate fiber (E) with the phosphoric acid ester compound to support the phosphorus element, the fiber bundle of the polyethylene naphthalate fiber (E) is immersed in a solution containing the phosphoric acid ester compound. A method of impregnating and attaching an acid ester compound and then drying by heating is mentioned. Here, the phosphorus element loading of the polyethylene naphthalate fiber (E) can be controlled by appropriately adjusting the concentration of the phosphate compound in the phosphate compound solution to be used. Here, the drying temperature is optimally 80 to 200 ° C. and the drying time is about 30 to 300 seconds from the standpoint of maintaining the strength of the fiber. Moreover, it is preferable that the dryer used is a non-contact type from the objective of maintaining the surface state of a fiber.

  In addition, when the below-mentioned surface treatment is applied to the polyethylene naphthalate fiber (E), the phosphoric acid ester compound is dissolved in the surface treatment solution at the above-described concentration to support the phosphorus element simultaneously with the surface treatment. It can be carried out.

Polyethylene naphthalate fibers used in the present invention (E) is state, and are not subjected to surface treatment by a surface treating agent, if surface treated polyethylene naphthalate fiber (E), the polylactic acid-based thermoplastic resin component Compatibility (adhesion) is improved, and a good flame-retardant composite polylactic acid-based thermoplastic resin composition can be obtained.

Examples of the surface treatment agent for polyethylene naphthalate fiber (E) include polyolefin resin, polyurethane resin, polyester resin, acrylic resin, epoxy resin, starch, plant extract, and a mixture of one or more of these and an epoxy compound. Although the like, surface treatment agent, particularly compatibility (adhesion) between the polylactic acid-based thermoplastic resin component of the point depot polyurethane resin including.

  The polyurethane resin as the surface treating agent is composed of a compound having two hydroxyl groups in the molecule (hereinafter referred to as diol component) and a compound having two isocyanate groups in the molecule (hereinafter referred to as diisocyanate component). Can be obtained by addition polymerization in an organic solvent that does not contain water and does not have active hydrogen. The target polyurethane resin can also be obtained by reacting raw materials directly in the absence of a solvent. Examples of the diol component include polyester diol, polyether diol, polycarbonate diol, polyether ester diol, polythioether diol, polyacetal, polysiloxane, and other polyol compounds, as well as ethylene glycol, 1,4-butanediol, 1, Examples include low molecular weight glycols such as 6-hexanediol, 3-methyl-1,5-pentanediol, and diethylene glycol. The polyurethane resin used as the surface treatment agent preferably contains a large amount of a low molecular weight glycol component.

  The polyurethane resin as the surface treatment agent is preferably uniformly adhered to the surface of each single yarn of polyethylene naphthalate fiber, which is a multifilament, so that the single yarn is converged, but with the polylactic acid-based thermoplastic resin component In the kneading step, it is preferable that the single yarn is dissociated with a low share and dispersed in the polylactic acid-based thermoplastic resin component. For that purpose, the tensile strength of the dry film of the polyurethane resin needs to be low, and the tensile strength of the dry film of the polyurethane resin is preferably 5 to 60 MPa, more preferably 10 to 50 MPa. When the tensile strength of the dry film of the resin is not less than the above lower limit value, the resin film is not easily broken, and convergence can be imparted to the surface-treated fiber. When the tensile strength of the dry film of the resin is not more than the above upper limit, the single yarn is easily dissociated in the kneading step, and the occurrence of dispersion spots on the surface-treated fibers can be prevented.

  The modulus at 100% elongation of the dry film of the polyurethane resin as the surface treatment agent is preferably 0.1 to 30 MPa, more preferably 1 to 20 MPa. When the modulus at 100% elongation of the dry film of the resin is equal to or more than the above lower limit value, the resin film is difficult to break, and convergence can be imparted to the surface-treated fibers. When the modulus at 100% elongation of the dry film of the resin is not more than the above upper limit value, the single yarn is easily dissociated in the kneading step, and the occurrence of dispersion spots on the surface-treated fibers can be prevented.

  Moreover, the elongation of the dry film of the polyurethane resin as the surface treatment agent is preferably 100 to 700%, more preferably 130 to 500%. When the elongation of the dry film of the resin is not less than the above lower limit value, the resin film does not become too hard and brittle, and the polyurethane resin does not easily break when an impact is applied to the molded product. A sufficient effect of reinforcing the components can be obtained. Moreover, when the elongation of the dry film of the resin is not more than the above upper limit value, the single yarn is easily dissociated in the kneading step, and the occurrence of dispersion spots on the surface-treated fibers can be prevented.

Here, the manufacturing method of the dry film of the polyurethane resin used for the measurement of the tensile strength and the modulus when the elongation is 100% and the elongation is as follows.
The water, which is a volatile component, is removed from the aqueous solution of the polyurethane resin by a casting method using a glass petri dish or Teflon petri dish. The treatment temperature at this time is about room temperature to 120 ° C., and a dry film can be obtained by appropriately setting the treatment time according to the sample. The film thickness of the dry film is preferably 0.1 to 1.0 mm, more preferably 0.5 to 1.0 mm. This dry film is processed according to the measurement item. For example, when measuring the tensile strength and elongation, a test piece is punched into a dumbbell shape to obtain a test piece for a tensile test.

  As described above, the polyurethane resin as the surface treatment agent has a low tensile strength and a modulus at 100% elongation of the dry film, and the elongation is preferably 700% or less. In such a case, in the process until the surface-treated fiber is mixed with the resin component, the surface-treated fiber is given convergence, and in the step of impregnating the surface-treated fiber bundle with the resin component, due to the share in the process, A multifilament can be easily dissociated into single yarns, resulting in a higher performance resin composition. In addition, the polyurethane resin is preferably a flexible resin having a dry film elongation of 100% or more. In such a case, the effect of reinforcing the resin component with fibers is increased, and a high-performance resin composition is obtained. It becomes a thing.

  The surface treatment of the polyethylene naphthalate fiber (E) can be performed by impregnating the fiber bundle of the polyethylene naphthalate fiber (E) with a treatment liquid containing the above-described surface treatment agent and drying it with heat. Here, it is optimal that the drying temperature is 80 to 200 ° C. and the drying time is about 30 to 300 seconds from the viewpoint of maintaining the strength of the fibers and bonding the surface treatment agent. Moreover, it is preferable that the dryer used is a non-contact type from the objective of maintaining the surface state of a fiber.

  Thus, when surface-treating the polyethylene naphthalate fiber with the surface treatment agent, the solid content of the surface treatment agent on the polyethylene naphthalate fiber after the surface treatment is 3 to 20% by weight, particularly 5 to 17%. It is preferable that it is weight%. When the adhesion amount of the surface treatment agent is equal to or more than the above lower limit value, the convergence is improved, the entanglement between the fibers is reduced, and the fiber is sufficiently mixed with the resin. You can get enough. On the contrary, by being below the above upper limit value, there is little occurrence of scum in the surface treatment process of the fiber while obtaining sufficient convergence that the fiber is uniformly dispersed when mixed with the resin, and the productivity is low. It will be improved.

  Polyethylene naphthalate fiber (E) may be used alone, fiber length, fiber diameter, presence / absence of phosphorous element loading / unloading amount, and different phosphoric acid ester compounds for phosphorus element loading Two or more types such as the presence or absence of the above-mentioned surface treatment and those with different surface treatment agents may be used in combination.

  In the present invention, the polyethylene naphthalate fiber (E) is added in an amount of 1 to 50 parts by weight to 100 parts by weight of the polylactic acid thermoplastic resin component. When the addition amount of the polyethylene naphthalate fiber (E) is not less than the above lower limit value, it is possible to obtain a good crystallization speed improvement effect, shorten the molding cycle, and improve the rigidity and flame retardancy. It can be obtained effectively. Moreover, when the addition amount of the polyethylene naphthalate fiber (E) is not more than the above upper limit value, the appearance of the molded product is improved, and the impact strength is prevented from being lowered by blending the polyethylene naphthalate fiber (E). be able to.

  The addition amount of the polyethylene naphthalate fiber (E) does not include the phosphorus element supported on the polyethylene naphthalate fiber (E) (that is, the above-described phosphate ester compound, etc.), and the polyethylene naphthalate fiber When (E) is subjected to a surface treatment with a surface treatment agent described later, the value does not include the weight of the surface treatment agent attached to the polyethylene naphthalate fiber (E) by this surface treatment.

[Other ingredients]
The flame-retardant composite polylactic acid-based thermoplastic resin composition of the present invention includes the polylactic acid resin (A), rubber-containing styrene-based resin (B), aromatic polycarbonate resin (C), flame retardant (D), and polyethylene naphthalate. In addition to the phthalate fiber (E), 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 and glass fibers, One type or two or more types of fillers such as talc, wollastonite, calcium carbonate and silica, antibacterial agents, antifungal agents, silicone oils, coupling agents and the like can be mentioned.

  Other resins include polycarbonate resins synthesized from fossil-derived resources or plant-derived resources other than aromatic polycarbonate resins, nylon resins, methacrylic resins, polyvinyl chloride resins, polybutylene terephthalate resins, polyethylene terephthalate resins, polyphenylene ethers. Resin etc. are mentioned. Moreover, what blended these 2 or more types may be sufficient, and you may mix | blend the said resin modified | denatured with the compatibilizer, the functional group, etc. further.

  However, in the flame-retardant composite polylactic acid-based thermoplastic resin composition of the present invention, the amount of the other resin described above is 50 parts by weight or less with respect to 100 parts by weight of the flame-retardant polylactic acid-based thermoplastic resin component, In particular, 30 parts by weight or less is preferable in terms of effective use of the polylactic acid resin.

[Production and molding of flame retardant composite polylactic acid-based thermoplastic resin composition]
The method for pelletizing the flame-retardant composite 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 an extruder is preferable, and if necessary, resin, fiber, and other additives can be blended by side feed or the like.

  The flame-retardant composite 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, and vacuum molding. From the industrial viewpoint, injection molding is particularly preferred.

  There are no particular restrictions on the use of the obtained molded product, but in the home appliance and OA fields, white home appliance parts, solar cell related parts, secondary battery parts, personal computer housings and parts, copier housings and components, mobile phone housings, For charging bases and automobiles, it can be suitably used for various interior / exterior parts such as interior pillars, front panels, side panels, trunk boards, tire covers, floor boxes, and particularly interior parts.

  In addition, when preparing each component of the flame-retardant composite polylactic acid-based thermoplastic resin composition of the present invention, or when mixing, kneading, and molding these components, the resin waste, etc., is left as it is or In some cases, it can be crushed and subjected to a melt regeneration process. In this case, it is possible to collect during molding, but it is also possible to collect it separately from the market and use it 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”, “L” means “fiber length”, and “R” means “fiber diameter”.

The weight average molecular weight was measured by a standard PS (polystyrene) conversion method using Tosoh Co., Ltd. product: 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.

[Polylactic acid resin (A)]
Polylactic acid resin (a-1): “Ingeo 3001D” manufactured by Nature Works
(L-form = 98 wt%, weight average molecular weight = 82,000, melting point
(Tm) = 170 ° C.)

[Rubber-containing styrene resin (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 composition.

[Combination]
Styrene (ST) 25 parts Acrylonitrile (AN) 10 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 80% by weight, average particle size 0.3 μm), heated to 60 ° C., ferrous sulfate, sodium pyrophosphate Crystalline glucose was added and ST, AN, t-DM and cumene hydroperoxide were continuously added over 2 hours while maintaining the temperature at 60 ° C., and then the temperature was raised to 70 ° C. and maintained for 1 hour to complete the reaction. . 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 composition 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 acrylonitrile (AN) 12 as a monomer. Part, styrene (ST) 14 parts, and methyl methacrylate (MMA) 14 parts were reacted except that graft polymerization was performed in the same manner as in Synthesis Example 1 to obtain an ASA graft copolymer (b-2). .

The rubber content of the rubber-containing graft copolymer produced in Synthesis Examples 1 and 2, the weight composition ratio of the monomer, the graft ratio, and the weight average molecular weight of the acetone-soluble component were measured. .
Rubber-containing graft copolymer (b-1): rubber content = 66.2% by weight
AN / ST = 28/72
Graft rate = 40%
Weight average molecular weight (Mw) = 154,000
Rubber-containing graft copolymer (b-2): rubber content = 60% by weight
AN / ST / MMA = 30/35/35
Graft rate = 51% by weight
Weight average molecular weight (Mw) = 138,000

[Hard copolymer (C)]
<Synthesis Example 3: Production of Hard Copolymer (b-3)>
A hard copolymer was synthesized by a suspension polymerization method as follows.
120 parts water, 0.002 part sodium alkylbenzene sulfonate, 0.5 part polyvinyl alcohol, 0.3 part azoisobutylnitrile, 0.5 part t-DM, 30 parts acrylonitrile (AN) and styrene in a nitrogen-substituted reactor (ST) A monomer mixture consisting of 70 parts was used, and after heating for 5 hours from a starting temperature of 60 ° C. while sequentially adding a portion of styrene, it was allowed to reach 120 ° C. Furthermore, after reacting at 120 ° C. for 4 hours, the polymer was taken out to obtain a vinyl copolymer (b-3).

<Synthesis Example 4: Production of Rigid Copolymer (b-4)>
As the monomer mixture, a monomer mixture consisting of 25 parts of acrylonitrile (AN), 20 parts of styrene (ST), 35 parts of α-methylstyrene (AMST) and 20 parts of N-phenylmaleimide (NPMI) was used, and styrene, α-methyl Polymerization was carried out in the same manner as in Synthesis Example 3 except that a part of styrene and N-phenylmaleimide was sequentially added to obtain a vinyl copolymer (b-4).

When the weight composition ratio and weight average molecular weight (Mw) of the monomers of the hard copolymer produced in Synthesis Examples 3 and 4 were measured, they were as follows.
Hard copolymer (b-3): AN / ST = 29/71
Weight average molecular weight (Mw) = 123,000
Rigid copolymer (b-4): AN / (ST + AMST) / NPMI = 24/57/19
Weight average molecular weight (Mw) = 150,000

  The rubber-containing styrenic resin (B) is obtained by appropriately blending the rubber-containing graft copolymers (b-1) and (b-2) and the hard copolymers (b-3) and (b-4). The rubber content of the rubber-containing styrenic resin (B), the weight-average molecular weight of the acetone-soluble component, and the graft ratio in the formulations shown in Table 1 are as shown in Table 1.

[Aromatic polycarbonate resin (C)]
Teijin Chemicals Limited: “Panlite L-1225L” (viscosity average molecular weight = 15,000, containing no chlorine or bromine atoms)

[Flame Retardant (D)]
Daihachi Chemical Industry Co., Ltd .: “PX-200 (Aromatic condensed phosphate ester flame retardant)”

[Polyethylene naphthalate fiber (E)]
<Preparation Example 1: Surface-treated polyethylene naphthalate fiber (e-1)>
Surface-treated polyethylene naphthalate fibers were prepared as follows.
Polyethylene naphthalate long fibers (R = 25 μm) were subjected to dip treatment using a polyurethane resin treatment solution.
Regarding the physical properties of the dry film obtained by evaporating water, which is a volatile component, from this polyurethane resin treatment liquid, the tensile strength was 15 MPa, the elongation was 150%, and the modulus at an elongation of 100% was 15 MPa. In the dip treatment, the treatment liquid was made to have a polyurethane resin concentration of 10% by weight, applied to the polyethylene naphthalate long fiber, and then subjected to a heat treatment at 180 ° C. for 60 seconds with a non-contact heater to obtain a polyurethane resin surface-treated polyethylene naphthalate length. Fiber was obtained. The amount of solid polyurethane resin adhered to the polyethylene naphthalate long fibers was 7% by weight. This fiber was cut into a length of 3 mm to obtain surface-treated polyethylene naphthalate fiber (e-1).

<Preparation Example 2: Phosphorus element-supported surface-treated polyethylene naphthalate fiber (e-2)>
A phosphorus element-supported surface-treated polyethylene naphthalate fiber was prepared as follows.
Polyethylene naphthalate long fibers (R = 25 μm) were subjected to a dip treatment using the following treatment liquid.
The treatment liquid had a polyurethane resin concentration of 10% by weight and triphenyl phosphate at a concentration of 15% by weight. The polyurethane resin used here was the same as the polyurethane resin used for the preparation of the surface-treated polyethylene naphthalate fiber (e-1). In the dip treatment, after applying the treatment liquid to the polyethylene naphthalate long fibers, heat treatment is performed at 180 ° C. for 60 seconds with a non-contact heater, and the amount of polyurethane resin solids attached to the polyethylene naphthalate long fibers is 7% by weight. Then, phosphorus element-supported polyurethane resin surface-treated polyethylene naphthalate long fibers were obtained. This fiber was cut into a length of 3 mm to obtain a phosphorus element-supported surface-treated polyethylene naphthalate fiber (e-2).
The surface treatment agent was extracted from this fiber with an organic solvent, and the content of phosphorus element was calculated from a calibration curve prepared in advance by elemental analysis. The content of phosphorus element relative to the polyethylene naphthalate long fiber was 1.0% by weight. It was.

<Preparation Example 3: Phosphorus element-supported surface-treated polyethylene naphthalate fiber (e-3)>
A phosphorus element-supported surface-treated polyethylene naphthalate fiber was prepared as follows.
Polyethylene naphthalate long fibers (R = 25 μm) were subjected to a dip treatment using the following treatment liquid.
The treatment liquid had a polyurethane resin concentration of 10% by weight and triphenyl phosphate at a concentration of 30% by weight. The polyurethane resin used here was the same as the polyurethane resin used for the preparation of the surface-treated polyethylene naphthalate fiber (e-1). In the dip treatment, the treatment liquid was applied to polyethylene naphthalate long fibers, and then heat treated at 180 ° C. for 60 seconds with a non-contact heater to obtain phosphorus element-supported polyurethane resin surface-treated polyethylene naphthalate long fibers. This fiber was cut to a length of 3 mm to obtain a phosphorus element-supported surface-treated polyethylene naphthalate fiber (e-3) in which the amount of polyurethane resin solids attached to the polyethylene naphthalate long fiber was 7% by weight.
The surface treatment agent was extracted from this fiber with an organic solvent, and the phosphorus element content was calculated from a calibration curve prepared in advance by elemental analysis. As a result, the phosphorus element content relative to the polyethylene naphthalate long fiber was 2.0% by weight. It was.

<Preparation Example 4: Phosphorus element-supported surface-treated polyethylene naphthalate fiber (e-4)>
A phosphorus element-supported surface-treated polyethylene naphthalate fiber was prepared as follows.
Polyethylene naphthalate long fibers (R = 25 μm) were subjected to a dip treatment using the following treatment liquid.
The treatment liquid had a polyurethane resin concentration of 10% by weight and triphenyl phosphate at a concentration of 75% by weight. The polyurethane resin used here was the same as the polyurethane resin used for the preparation of the surface-treated polyethylene naphthalate fiber (e-1). In the dip treatment, after applying the treatment liquid to the polyethylene naphthalate long fibers, heat treatment is performed at 180 ° C. for 60 seconds with a non-contact heater, and the amount of polyurethane resin solids attached to the polyethylene naphthalate long fibers is 7% by weight. Then, phosphorus element-supported polyurethane resin surface-treated polyethylene naphthalate long fibers were obtained. This fiber was cut into a length of 3 mm to obtain a phosphorus element-supported surface-treated polyethylene naphthalate fiber (e-4).
The surface treatment agent was extracted from this fiber with an organic solvent, and the content of phosphorus element was calculated from a calibration curve prepared in advance by elemental analysis. The content of phosphorus element relative to the polyethylene naphthalate long fiber was 5.0% by weight. It was.

[Production and Evaluation of Flame Retardant Composite Polylactic Acid Thermoplastic Resin Composition Pellet]
Each of the above components were mixed at the blending ratios shown in Tables 1 and 2 and further mixed with 0.3 parts of “Carbodilite HMV-8CA” manufactured by Nisshinbo Co., Ltd. as a stabilizer. The pellets of the thermoplastic resin composition were prepared by melt-mixing with a shaft extruder (“TEX-30α” manufactured by Nippon Steel Works) and pelletizing.
These resin pellets are molded at 220 to 250 ° C. and mold temperature: 85 ° C. with a 2 ounce injection molding machine (manufactured by Toshiba Corporation), and have heat resistance (deflection temperature under load) and impact resistance (Charpy impact strength). ), Rigidity (flexural modulus), and flame retardancy were evaluated by the following methods.

Deflection temperature under load (° C.): Measured according to ISO 75 (measurement load 0.45 MPa) Charpy impact strength (KJ / m): Measured according to ISO 179 (normal temperature) Flexural modulus (MPa): ISO 178 Measured according to (normal temperature) Flammability: Measured according to UL94 V test method
(Test piece thickness: 1.5 mm, 1.0 mm, and 0.70 mm, respectively)

[Examples and Comparative Examples]
Tables 1 and 2 show the results of Examples 1 to 7 and Comparative Examples 1 to 4.

[Discussion]
As is clear from Tables 1 and 2, the flame retardant composite polylactic acid-based thermoplastic resin compositions of Examples 1 to 7 that satisfy the requirements of the claims of the present invention have a balance of physical properties of impact resistance, heat resistance, and rigidity. Excellent, in addition, good flame retardancy.

  On the other hand, the composition of Comparative Example 1 in which the amount of phosphorus element supported on the polyethylene naphthalate fiber is too large has a poor physical property balance, and the composition not containing the polyethylene naphthalate fiber of Comparative Example 2 has a physical property balance and difficulty. Inferior to flammability. In Comparative Example 3 having more polyethylene naphthalate fibers than the range of the present invention, impact strength and flame retardancy cannot be obtained. Moreover, in the case of the comparative example 4 which does not add the aromatic polycarbonate resin which is an essential component of this invention, the target physical property and combustibility cannot be obtained similarly.

In the flame-retardant composite polylactic acid-based thermoplastic resin composition of the present invention, a molded product obtained by injection molding exhibits excellent physical property balance and flame retardancy.
For this reason, molded products obtained by molding the flame-retardant composite polylactic acid-based thermoplastic resin composition of the present invention are, for example, copying machine parts, personal computer parts, TV parts, mobile phone parts, etc. Can be used mainly. Its industrial utility is very high, and it is also effective for reducing the environmental load.

Claims (6)

For 100 parts by weight of a polylactic acid thermoplastic resin component consisting of 10 to 95% by weight of a polylactic acid resin (A) and 90 to 5% by weight of a rubber-containing styrene resin (B),
Flame retardant composite polylactic acid-based thermoplastic resin comprising 50 to 200 parts by weight of aromatic polycarbonate resin (C), 1 to 50 parts by weight of flame retardant (D) and 1 to 50 parts by weight of polyethylene naphthalate fiber (E) A composition comprising:
The polyethylene naphthalate fiber (E) does not carry phosphorus element, or carries 3.0% by weight or less of phosphorus element with respect to the fiber weight , and the polyethylene naphthalate fiber (E ), the flame retardant composite polylactic acid thermoplastic resin composition characterized der Rukoto subjected to surface treatment by a surface treating agent containing a polyurethane resin.   2. The rubbery polymer in the rubber-containing styrene resin (B) is at least one selected from the group consisting of polybutadiene rubber, acrylic rubber, and olefin rubber. Flame retardant composite polylactic acid-based thermoplastic resin composition.   The flame-retardant composite polylactic acid-based thermoplastic resin composition according to claim 1 or 2, wherein the aromatic polycarbonate resin (C) does not contain a chlorine atom or a bromine atom in the molecular structure.   The flame retardant composite polylactic acid-based thermoplastic resin composition according to any one of claims 1 to 3, wherein the flame retardant (D) includes a phosphate ester-based flame retardant. The difficulty according to any one of claims 1 to 4 , wherein the polyethylene naphthalate fiber (E) is supported with the phosphorus element by being treated with a phosphate ester compound. A flame retardant polylactic acid-based thermoplastic resin composition. A molded product formed by molding the flame-retardant composite polylactic acid-based thermoplastic resin composition according to any one of claims 1 to 5 .