JP4651952B2 - Flame-retardant polyester resin composition and molded product obtained by molding the same - Google Patents

Description

The present invention relates to a flame retardant resin composition comprising a biodegradable polyester resin derived from a natural product and a thermoplastic polyester resin copolymerized with a phosphorus compound, and a molded article formed by molding the flame retardant resin composition. The present invention relates to a resin composition having a low dependence on petroleum-based products having excellent mechanical strength, heat resistance and flame retardancy, and a molded article molded using the resin composition.

Generally, resins such as polypropylene (PP), ABS, polyamide (PA6, PA66, etc.), polyester (PET, PBT, etc.), polycarbonate (PC), etc. are used as raw materials for molding. However, moldings made from such resins are excellent in moldability and mechanical strength. However, when they are discarded, they increase the amount of dust and are hardly decomposed in the natural environment. However, it remains in the ground semipermanently. These resins are petroleum-based resins using petroleum as a starting material, and have a large environmental load during production.

On the other hand, in recent years, biodegradable polyester resins such as polylactic acid have attracted attention from the viewpoint of environmental conservation (for example, Patent Document 1). Among the biodegradable resins, polylactic acid is one of the resins with the highest heat resistance, and can be mass-produced, so the cost is low and the utility is high. Furthermore, polylactic acid can be produced using plants such as corn and sweet potato as raw materials, and can contribute to saving depleted resources such as oil.

In order to use such a biodegradable polyester resin for a housing or the like of home appliances, it is necessary to impart flame retardancy. However, if sufficient flame retardancy is to be ensured by adding a conventionally known flame retardant, there is a problem that mechanical strength and heat resistance are lowered. In particular, simply kneading a phosphorus compound for the purpose of imparting flame retardancy increases the amount of phosphorus compound required for imparting flame retardancy, affecting the physical properties, especially thermal properties. There was a problem such as lowering. It is also possible to directly copolymerize phosphorus compounds with polylactic acid. However, the introduction of phosphorus compounds during polylactic acid polymerization, which is a plant-derived green plastic, is a polylactic acid that is attracting attention from the environmental aspect. There was a problem of going backwards from the image.

Japanese Patent Laid-Open No. 06-023828

The present invention is intended to solve the above-described problems, and provides a resin composition and a molded article that are excellent in mechanical strength, heat resistance, and flame retardancy, and at the same time have low dependence on petroleum-based products. It is in.

As a result of intensive studies to solve the above problems, the present inventors have copolymerized a biodegradable polyester resin derived from a natural product and 2-methyl-2,5-dioxo-1-oxa-2-phosphorane. It was found that a resin composition in which polyethylene glycol dimethacrylate was blended with a resin composition mixed with a thermoplastic polyester resin in a specific range has flame resistance without impairing mechanical strength and heat resistance. The invention has been reached.

That is, the gist of the present invention is as follows.
(1) Thermoplastic polyester resin (B) obtained by copolymerizing 50 to 80% by mass of a biodegradable polyester resin (A) derived from a natural product and 2-methyl-2,5-dioxo-1-oxa-2-phosphorane ) A flame-retardant polyester resin composition obtained by blending 0.01 to 20 parts by mass of polyethylene glycol dimethacrylate (C) with 100 parts by mass of a flame-retardant polyester resin composition comprising 50 to 20% by mass.
(2) The flame retardant polyester resin composition according to (1), wherein the biodegradable polyester resin (A) derived from a natural product is polylactic acid.
(3) The thermoplastic polyester resin (B) copolymerized with 2-methyl-2,5-dioxo-1-oxa-2-phosphorane is a biodegradable polyester resin (B1) (1) or (2 ) The flame retardant polyester resin composition described in 1.).
(4) The flame-retardant polyester resin composition according to (3), wherein the biodegradable polyester resin (B1) is a polyester mainly composed of polybutylene succinate.
(5) A flame retardant obtained by further blending 0.1 to 20 parts by mass of a layered silicate (D) per 100 parts by mass of the flame retardant polyester resin composition according to any one of (1) to (4). Polyester resin composition.

(6) The flame-retardant polyester resin composition according to any one of (1) to (5), wherein the phosphorus content is 750 ppm or more.
(7) A molded article obtained by molding the flame-retardant polyester resin composition according to any one of (1) to (6).

ADVANTAGE OF THE INVENTION According to this invention, the resin composition with the low dependence on the petroleum-type product which has the outstanding mechanical characteristic, heat resistance, and a flame retardance is provided. This resin composition can be formed into a molded body by various molding methods including injection molding. In addition, since a biodegradable resin derived from a natural product is used, it can contribute to saving of depleted resources such as oil.

Hereinafter, the present invention will be described in detail.

The flame-retardant resin composition of the present invention comprises a natural product-derived biodegradable polyester resin (A) 50 to 80% by mass and a thermoplastic polyester resin (B) 50% by mass to which an organic phosphorus compound is copolymerized. Therefore, the preferable mixing range is polyester (A) / polyester (B) = 60 to 80% by mass / 40 to 20% by mass. If the blending amount of the thermoplastic polyester resin (B) copolymerized with an organophosphorus compound exceeds 50% by mass, the proportion of petroleum-based raw materials is higher than that of natural-derived raw materials, contributing to the saving of depleted resources such as petroleum. I can't say that I can do it. In addition, when the blending amount of the natural product-derived biodegradable polyester resin (A) exceeds 80% by mass and the blending amount of the thermoplastic polyester resin copolymerized with the organic phosphorus compound is less than 20% by mass, it is sufficient. Incombustibility cannot be obtained.

The phosphorus content in the flame-retardant polyester resin composition of the present invention is preferably 750 ppm or more, more preferably 1000 ppm or more, and more preferably 1300 ppm as phosphorus atoms. If it is less than 750 ppm, sufficient flame retardancy may not be obtained. Further, there is no particular upper limit on the phosphorus atom content, but it is 10000 ppm or less, preferably 5000 ppm or less. In the present invention, ppm means mass ppm.

Examples of the natural product-derived biodegradable polyester resin (A) in the present invention include polylactic acid. Of these, poly (L-lactic acid), poly (D-lactic acid), and mixtures or copolymers thereof can be used from the viewpoints of heat resistance and moldability. From the viewpoint of biodegradability, poly (L-lactic acid) can be used. -Lactic acid) is preferred.

Further, the melting point of polylactic acid mainly composed of poly (L-lactic acid) varies depending on the optical purity. However, in the present invention, the melting point is 160 ° C. or higher in consideration of the mechanical properties and heat resistance of the molded product. It is preferable that In order to obtain a melting point of 160 ° C. or higher in polylactic acid mainly composed of poly (L-lactic acid), the ratio of the D-lactic acid component may be less than about 3 mol%.

In addition, polybutylene succinate is currently synthesized from petroleum raw materials and is not a resin derived from natural products, but is expected to be produced from raw materials derived from natural products in the future. The biodegradable polyester resin (A) derived from a natural product can be used for the purpose of the present invention.

The melt flow rate of the biodegradable polyester resin (A) at 190 ° C. and a load of 21.2 N is 0.1 to 50 g / 10 min, preferably 0.2 to 20 g / 10 min, more preferably 0.5 to 10 g / min. 10 minutes. When the melt flow rate exceeds 50 g / 10 min, the melt viscosity is too low, and the mechanical properties and heat resistance of the molded product are inferior. When the melt flow rate is less than 0.1 g / 10 min, the load during the molding process becomes too high and the operability may be lowered.

The biodegradable polyester resin (A) is usually produced by a well-known melt polymerization method or by further using a solid phase polymerization method. As a method for adjusting the melt flow rate of the biodegradable polyester resin to a predetermined range, if the melt flow rate is too large, a small amount of chain extender, for example, diisocyanate compound, bisoxazoline compound, epoxy compound, acid anhydride And a method of increasing the molecular weight of the resin by using an object. On the contrary, when the melt flow rate is too small, a method of mixing with a biodegradable polyester resin or a low molecular weight compound having a large melt flow rate can be mentioned.

The thermoplastic polyester (B) in which the organic phosphorus compound in the present invention is copolymerized is obtained by further copolymerizing an organic phosphorus compound with a thermoplastic polyester comprising a dicarboxylic acid component and a diol component or a hydroxycarboxylic acid component. It may be a crystalline polyester or an amorphous polyester. In addition, the polyester (B) may be a biodegradable polyester. In such a case, since the components (A) and (B) are both biodegradable, the whole becomes biodegradable, Preferably, if the component (B) is an aliphatic polyester, the compatibility with the component (A) can be increased, and the impact resistance can be improved.

Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, orthophthalic acid, chlorophthalic acid, nitrophthalic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and 1,5-naphthalene. Dicarboxylic acid, methyl terephthalic acid, 4,4'-biphenyl dicarboxylic acid, 2,2'-biphenyl dicarboxylic acid, 4,4'-biphenyl ether dicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenyl Sulfone dicarboxylic acid, aromatic dicarboxylic acid such as 4,4′-diphenylisopropylidenedicarboxylic acid, 1,2-bis (4-carboxyphenoxy) ethane, 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, Suberic acid, azelaic acid, sebacic acid Dodecanedioic acid, octadecane dicarboxylic acid, dimer acid, maleic acid, aliphatic dicarboxylic acids such as fumaric acid, alicyclic dicarboxylic acids such as 1,4-cyclohexane dicarboxylic acid.

Examples of the diol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, diethylene glycol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1, Aliphatic diols such as 8-octanediol and 1,10-decanediol, alicyclic diols such as 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol and 1,2-cyclohexanedimethanol, bisphenol A, Bisphenols such as bisphenol S or their ethylene oxide adducts, aromatic diols such as hydroquinone, resorcinol and the like can be mentioned.

Furthermore, examples of the hydroxycarboxylic acid component include p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid, 6-hydroxycaproic acid and other hydroxycarboxylic acids, δ-valerolactone, γ-butyrolactone, ε- Examples include lactone compounds such as caprolactone.

Examples of the main skeleton of the thermoplastic polyester resin (B) obtained from the above components include polyethylene terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene naphthalate, polybutylene as an aromatic component. Naphthalate, polyethylene isophthalate / terephthalate, polybutylene isophthalate / terephthalate, polyethylene terephthalate / cyclohexylene dimethylene terephthalate, cyclohexylene dimethylene isophthalate / terephthalate, poly (p-hydroxybenzoic acid / ethylene terephthalate), etc. Biodegradable polyesters include polyethylene succinate, polybutylene succinate, polybutylene terephthalate / adipate. , Include aliphatic polyesters such as polybutylene succinate / polylactic acid copolymer, said polyethylene terephthalate Among, polybutylene terephthalate, polybutylene succinate, polybutylene succinate / polylactic acid copolymer is particularly preferred.

The intrinsic viscosity of the thermoplastic polyester resin (B) is preferably 0.50 dl / g or more, and more preferably 0.70 to 1.20 dl / g. When the intrinsic viscosity is less than 0.50 dl / g, the mechanical strength when formed into a molded product is lowered. On the other hand, when the relative viscosity exceeds 1.20 dl / g, the moldability is lowered, which is not preferable.

Furthermore, an organic phosphorus compound is copolymerized with the thermoplastic polyester resin (B) in order to impart flame retardancy. The copolymerization amount of the phosphorus compound is preferably 500 ppm or more as the phosphorus atom content in the thermoplastic polyester resin (B). If the amount of phosphorus is less than 500 ppm, the resin composition as a whole may have insufficient flame retardancy. Moreover, since there exists a tendency for resin to color yellow or mechanical strength to be impaired when the amount of copolymerization becomes high, it is preferable that it is 20000 ppm or less. The copolymerization amount of the organic phosphorus compound is preferably 0.3 mol% to 14 mol%, more preferably 2.0 mol% to 12 mol, with respect to the acid component constituting the polyester (B). %.

Preferable examples of the organic phosphorus compound include ethylene glycol ester of 2-methyl-2,5-dioxo-1-oxa-2-phosphorane (compound represented by (a) below) and the like.

Said phosphorus compound is added and copolymerized when manufacturing a polyester resin by a conventional method. At this time, it may be added in the form of a monomer, oligomer or polymer reacted with an acid component such as terephthalic acid, isophthalic acid or succinic acid.

The flame retardant resin composition of the present invention needs to contain a (meth) acrylic acid ester compound (C). By this component, the polyester resin component is cross-linked, and mechanical strength, heat resistance, and dimensional stability are improved. The (meth) acrylic acid ester compound has high reactivity with the biodegradable resin, it is difficult for the monomer to remain, and the resin is less colored, so it has two or more (meth) acryl groups in the molecule, or Compounds having one or more (meth) acryl groups and one or more glycidyl groups or vinyl groups are preferred. Specific examples of the compound include polyethylene glycol dimethacrylate.

When the (meth) acrylic acid ester compound (C) is blended, the amount thereof is 0.01 to 20 parts by weight, preferably 100 parts by weight of the total of the polyester resin (A) and the polyester resin (B). 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass is appropriate. If the operability is not particularly hindered, it can be used in excess of 20 parts by mass.

When the (meth) acrylic acid ester compound (C) is blended, it is preferable to use a peroxide in combination because the crosslinking reaction is promoted. Specific examples of peroxides include benzoyl peroxide, bis (butylperoxy) trimethylcyclohexane, bis (butylperoxy) cyclododecane, butylbis (butylperoxy) valerate, dicumyl peroxide, butylperoxybenzoate, dibutyl Examples thereof include peroxide, bis (butylperoxy) diisopropylbenzene, dimethyldi (butylperoxy) hexane, dimethyldi (butylperoxy) hexyne, and butylperoxycumene. 0.1-20 mass parts is preferable with respect to 100 mass parts of sum total of (A) and (B) component, and, as for the compounding quantity of a peroxide, More preferably, it is 0.1-10 mass parts. Although it can be used even if it exceeds 20 parts by mass, it is disadvantageous in terms of cost. In addition, since such a peroxide decomposes | disassembles at the time of mixing with resin, even if it is used at the time of manufacture, it may not be contained in the obtained resin composition.

As a means for blending the (meth) acrylic acid ester compound (C) into the biodegradable polyester resin (A) and the thermoplastic polyester resin (B), or a mixture thereof, melt kneading is performed using a general extruder. A method can be mentioned. In order to improve the kneading state, it is preferable to use a twin screw extruder. The kneading temperature is preferably in the range of (melting point of polyester resin (A) + 5 ° C.) to (melting point of polyester resin (A) + 100 ° C.), and the kneading time is preferably from 20 seconds to 30 minutes. If the temperature is lower or shorter than this range, kneading or reaction is insufficient, and if the temperature is higher or longer, the resin may be decomposed or colored.

As a preferable method when the (meth) acrylate compound and the peroxide are used in combination, a method in which the (meth) acrylate compound and / or the peroxide is dissolved or dispersed in a medium and injected into a kneader. As a result, the operability can be remarkably improved. That is, during melting and kneading of the polyester resin component and peroxide, a solution or dispersion of the (meth) acrylic acid ester compound is injected, or during melting and kneading of the polyester resin, the (meth) acrylic acid ester compound And a solution or dispersion of peroxide can be injected and melt kneaded.

As a medium for dissolving or dispersing the (meth) acrylic ester compound and / or peroxide, a general one is used, and is not particularly limited, but has excellent compatibility with the flame retardant resin composition of the present invention. A plasticizer is preferred. For example, one or more selected from aliphatic polycarboxylic acid ester derivatives, aliphatic polyhydric alcohol ester derivatives, aliphatic oxyester derivatives, aliphatic polyether derivatives, aliphatic polyether polycarboxylic acid ester derivatives, etc. A plasticizer etc. are mentioned. Specific examples of the compound include dimethyl adipate, dibutyl adipate, triethylene glycol diacetate, methyl acetyl ricinoleate, acetyl tributyl citric acid, polyethylene glycol, and dibutyl diglycol succinate. As a usage-amount of a plasticizer, 30 mass parts or less are preferable with respect to 100 mass parts of sum total of (A) (B), and 0.1-20 mass parts is further more preferable. When the reactivity of the crosslinking agent is low, it is not necessary to use the plasticizer, but when the reactivity is high, it is preferable to use 0.1 parts by mass or more. In addition, since this medium may volatilize at the time of mixing with resin, even if it uses it at the time of manufacture, this medium may not be contained in the obtained resin composition.

The flame retardant resin composition of the present invention may contain a layered silicate (D) for the purpose of improving mechanical strength and heat resistance. The blending amount is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the sum of the components (A) and (B). Specific examples of the layered silicate include smectite, vermiculite, and swellable fluorine mica. Examples of smectites include montmorillonite, beidellite, hectorite, and saponite. Examples of swellable fluorine mica include Na-type fluorine tetrasilicon mica, Na-type teniolite, Li-type teniolite, etc. In addition to the above, aluminum and magnesium such as kanemite, macatite, magadiite, and kenyaite are not included. Layered silicates can also be used. These layered silicates may be natural products or synthetic products. The synthetic product may be produced by any method such as a melting method, an intercalation method, or a hydrothermal method. These layered silicates may be used alone, but may be used in combination of two or more kinds having different mineral types, production areas, production methods, particle sizes and the like.

The layered silicate (D) is preferably pretreated with an organic cation. Examples of the organic cation include ammonium ions generated by protonation of primary to tertiary amines, onium ions such as quaternary ammonium ions and phosphonium ions. Examples of the primary amine include octylamine, dodecylamine, octadecylamine and the like. Examples of secondary amines include dioctylamine, methyloctadecylamine, and dioctadecylamine. Examples of the tertiary amine include trioctylamine, dimethyldodecylamine, didodecylmonomethylamine and the like. Examples of quaternary ammonium ions include tetraethylammonium, octadecyltrimethylammonium, dimethyldioctadecylammonium, dihydroxyethylmethyloctadecylammonium, methyldodecylbis (polyethylene glycol) ammonium, methyldiethyl (polypropyleneglycol) ammonium and the like. Furthermore, examples of the phosphonium ion include tetraethylphosphonium, tetrabutylphosphonium, hexadecyltributylphosphonium, tetrakis (hydroxymethyl) phosphonium, 2-hydroxyethyltriphenylphosphonium, and the like. Of these, treatment with ammonium ions having one or more hydroxyl groups in the molecule, such as dihydroxyethylmethyloctadecylammonium, methyldodecylbis (polyethylene glycol) ammonium, methyldiethyl (polypropyleneglycol) ammonium, 2-hydroxyethyltriphenylphosphonium, etc. The layered silicate is particularly preferable because it has a high affinity with a polyester resin, particularly a biodegradable polyester resin, and the dispersibility of the layered silicate is improved. These compounds may be used alone or in combination of two or more.

Further, as a method of treating the layered silicate (D) with the above organic cation, first, the layered silicate is dispersed in water or alcohol, and the above organic cation is added in the form of a salt and mixed by stirring. And a method in which the inorganic ions of the layered silicate are ion exchanged with organic onium ions, followed by filtration, washing and drying.

When the layered silicate (D) is used, a compatibilizing agent may be used in order to improve the dispersibility in the polyester resin. The addition amount is preferably 0.01 to 10 parts by mass, more preferably 0.02 to 5 parts by mass, with respect to 100 parts by mass of the sum of components (A) and (B). If it exceeds 10 parts by mass, the heat resistance and mechanical strength of the biodegradable polyester resin composition may be lowered. As the compatibilizing agent, compounds such as polyalkylene oxide, aliphatic polyester, polyhydric alcohol ester, polyhydric carboxylic acid ester having affinity with both polyester resin, especially biodegradable polyester resin and layered silicate are used. It is done. Examples of polyalkylene oxides include polyethylene glycol, polypropylene glycol, polybutylene glycol, and copolymers thereof, one or two of the terminal hydroxyl groups may be alkoxy-capped, and may be monocarboxylic acid or dicarboxylic acid. It may be esterified with an acid. Examples of aliphatic polyesters include polylactic acid, polyglycolic acid, poly (3-hydroxybutyric acid), poly (3-hydroxyvaleric acid), poly (3-hydroxycaproic acid) and other polyhydroxycarboxylic acids, poly (ε -Caprolactone), poly (ω-hydroxyalkanoate) represented by poly (δ-valerolactone), poly (ethylene succinate), poly (butylene succinate), poly (butylene succinate-co-butylene adipate), etc. And aliphatic polyesters composed of a diol and a dicarboxylic acid represented by In these aliphatic polyesters, the terminal carboxyl group may be esterified with an alcohol or may be hydroxyl-substituted with a diol. Examples of the polyhydric alcohol ester include glycerin esters such as monoglyceride, diglyceride and triglyceride which are esters of glycerin and fatty acid, pentaerythritol ester and the like. Examples of polyvalent carboxylic acid esters include citric acid esters such as tributyl citrate and tributyl citrate.

The compatibilizing agent preferably has a boiling point of 250 ° C. or higher. When the boiling point is less than 250 ° C., gas generation during molding and bleeding out from the obtained molded product may occur. The number average molecular weight is preferably in the range of 200 to 50,000, more preferably 500 to 20,000. When the molecular weight is less than 200, gas generation during molding and bleeding out from the resulting molded product are likely to occur, and the mechanical strength and heat resistance of the molded product may be impaired. When the molecular weight exceeds 50,000, the effect of improving the dispersibility of the layered silicate tends to be small.

As a method for adding a compatibilizing agent, a method of impregnating the above compound directly into a layered silicate in advance, a method of mixing the above compound in the presence of water or an organic solvent, and then removing water or the organic solvent by filtration or the like, a polyester resin And a method of adding together with a layered silicate at the time of synthesizing a polyester resin, etc., but prior to mixing with the polyester, a method of mixing the layered silicate in advance Is preferably used.

When layered silicate is added to the flame retardant resin composition of the present invention, the preferable dispersion state is a complete delamination type in which each layer of layered silicate is peeled one by one, or resin molecules are inserted between the layers. There is an interlayer insertion type or a mixed type thereof. Quantitatively, it is preferable that the average thickness of the single layer or laminated layer of a layered silicate observed with a transmission electron microscope is 1 to 100 nm, more preferably 1 to 50 nm, and still more preferably 1 to 20 nm. Alternatively, the interlayer distance of the layered silicate observed by X-ray diffraction is preferably 2.5 nm or more, more preferably 3 nm or more, still more preferably 4 nm or more, and most preferably a peak derived from the interlayer distance. Is not observed. Examples of the method for controlling the dispersibility of the layered silicate include, in the kneading method, change of kneading conditions, use of the compatibilizer described above, introduction of polar groups into the resin, and the like. In general, when a layered silicate is added during polymerization of polyester, dispersibility can be further improved.

As long as the properties of the flame retardant resin composition of the present invention are not greatly impaired, pigments, heat stabilizers, antioxidants, weathering agents, flame retardants, plasticizers, lubricants, mold release agents, antistatic agents, filling A material, a crystal nucleus material, or the like can be added. Examples of heat stabilizers and antioxidants include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, and alkali metal halides. Inorganic fillers include talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, Examples thereof include zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate, boron nitride, graphite, glass fiber, and carbon fiber. Examples of the organic filler include naturally occurring polymers such as starch, cellulose fine particles, wood flour, okara, fir shell, bran, and modified products thereof. Examples of the inorganic crystal core material include talc and kaolin. Examples of the organic crystal core material include a sorbitol compound, benzoic acid and a metal salt of the compound, a phosphate metal salt, and a rosin compound. In addition, the method of mixing these with the flame retardant resin composition of this invention is not specifically limited.

The flame-retardant resin composition of the present invention can be formed into various molded bodies by injection molding, blow molding, extrusion molding, inflation molding, and molding methods such as vacuum molding, pressure molding, and vacuum / pressure molding after sheet processing. it can. In particular, it is preferable to adopt an injection molding method, and in addition to a general injection molding method, gas injection molding, injection press molding, or the like can be employed. If an example of the injection molding conditions suitable for the resin composition of this invention is given, cylinder temperature will be Tm (the highest value of a polyester resin (A) or (B)) or flow start temperature more than a flame-retardant resin composition, Preferably Is in the range of 190 to 280 ° C., more preferably 210 to 270 ° C., and the mold temperature is suitably (Tm−20 ° C.) or less of the flame retardant resin composition. If the molding temperature is too low, the operability becomes unstable or overloading occurs, such as a short circuit in the molded product. Conversely, if the molding temperature is too high, the flame-retardant resin composition decomposes and the resulting molding is obtained. Problems such as reduction in body strength and coloration tend to occur.

The flame-retardant resin composition of the present invention can enhance its heat resistance by promoting crystallization. As a method for this purpose, for example, there is a method of promoting crystallization by cooling in a mold at the time of injection molding. In that case, the mold temperature is not less than (Tg + 20 ° C.) of the flame-retardant resin composition. , (Tm-20 ° C.) or less, and after maintaining for a predetermined time, cooling to Tg or less is preferable. Further, as a method for promoting crystallization after molding, it is preferable to directly heat the sample at Tg or more and (Tm−20 ° C.) or less after cooling to Tg or less.

Specific examples of the molded body include various housings such as TVs, liquid crystal televisions, plasma televisions, personal computer displays, laptop computers, CDs, DVDs, MDs, video decks, cassette decks, amplifiers, radios, air conditioners, compressors, rice cookers, Examples include electrical appliance casings and resin parts such as irons, dryers, dishwashers, and washing machines, automotive resin parts such as bumpers, instrument panels, and door trims, and parts for various electric tools. Moreover, it can also be set as a film, a sheet | seat, a hollow molded product, etc.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples. The measuring method used for evaluation of the resin composition of an Example and a comparative example is as follows.
(1) Phosphorus atom content:
Measurement was performed with a fluorescent X-ray spectrometer 3270 type manufactured by Rigaku Corporation.
(2) Melt flow rate (MFR):
According to JIS standard K-7210 (test condition 4), it measured at 190 degreeC and the load 21.2N.
(3) Intrinsic viscosity (IV):
Measurement was performed at a temperature of 20 ° C. using a phenol / 1,1,2,2-tetrachloroethane mixed solvent (mass ratio 6/4).
(4) Thermal deformation temperature:
According to ASTM standard D-648, the heat distortion temperature was measured at a load of 0.45 MPa.
(5) Impact strength:
According to ASTM standard D-256, Izod impact strength was measured using a test piece with a notch (V-shaped cut).
(6) Flexural modulus:
In accordance with ASTM standard D-790, a load was applied at a deformation rate of 1 mm / min, and the flexural modulus was measured.
(7) Flame retardancy:
Evaluation was performed according to the vertical burn test method of Underwriters Laboratories Inc. UL-94 standard. That is, a test piece having a length of 127 mm, a width of 12.7 mm, and a thickness of 0.8 mm (1/32 inch) is kept vertical, and the flame is removed after indirect flame is burned for 10 seconds at the lower end. The time when the fire that ignited was extinguished was measured. Next, at the same time when the fire was extinguished, the second flame contact was started for 10 seconds, and the time when the ignited fire extinguished was measured in the same manner as the first time. Moreover, it was also evaluated at the same time whether or not the cotton under the test piece ignited by the falling fire type.
Whether it corresponds to the rank of V-0, V-1, or V-2 according to the above-mentioned UL-94 standard vertical combustion test method from the first and second burning time, the presence or absence of cotton ignition, etc. Evaluated. Moreover, as a result of lack of practical flame retardancy, none of the above levels V-0 to V-2 was reached, and the evaluation that the combustion progressed to the clamp part of the test piece was evaluated as x.

Various raw materials used in Examples and Comparative Examples are as follows.
(1) Polylactic acid (PLA): NatureWorks 4030D manufactured by Cargill Dow; MFR = 3.0, melting point 166 ° C.
(2) Polybutylene succinate (PBS): AZ71T manufactured by Mitsubishi Chemical Corporation. (MFR = 15, melting point = 110 ° C.)

(3) Flame retardant PET: 4.5 mol% of 2-methyl-2,5-dioxo-1-oxa-2-phosphorane ethylene glycol ester (product of Hoechst: product name phosphorane) is copolymerized as an organic phosphorus compound Polyethylene terephthalate (IV 0.6, phosphorus content 7000 ppm).
It was manufactured as follows.
A 50 mass% ethylene glycol solution was added so that phosphorane was 4.5 mol% with respect to the terephthalic acid component of the PET oligomer having an average degree of polymerization of 7, and 2 × 10 ⁻⁴ mol per 1 mol of the acid component was used as a catalyst. Antimony trioxide, 4 × 10 ⁻⁵ mol of cobalt acetate and 1 × 10 ⁻⁴ mol of triethyl phosphate were charged into a polycondensation reaction apparatus, and polycondensation was performed at 280 ° C. under reduced pressure of 1 hPa or less for 6 hours.

(4) Flame retardant PBS: 4.5 mol% of 2-methyl-2,5-dioxo-1-oxa-2-phosphorane ethylene glycol ester (manufactured by Hoechst: product name phosphorane) is copolymerized as an organic phosphorus compound Polybutylene succinate (IV 0.6, phosphorus content 6000 ppm).
It was manufactured as follows.
1.6-fold moles of butanediol with respect to succinic acid and succinic acid, 4.5 mole% of phosphorane with respect to succinic acid, and 1 × 10 ⁻⁴ mole of tetrabutyl titanate with respect to 1 mole of succinic acid as a catalyst Was added to the reaction kettle and subjected to esterification at 200 ° C. for 4 hours. Then, 2 × 10 ⁻⁴ mol of tetrabutyl titanate per 1 mol of succinic acid component was added as a catalyst, and 6 ° C. under a reduced pressure of 1 hPa or less at 240 ° C. Polycondensation was performed for a time.

Reference Example 1 (Resin Composition A)
Using a twin screw extruder (Ikegai PCM-30, die diameter: 4 mm × 3 holes, extrusion head temperature: 260 ° C., die exit temperature: 240 ° C.), 65 parts by mass of PLA and 35 parts by mass of flame-retardant PET are supplied and melted. Kneading extrusion was performed, and the discharged resin was cut into pellets to obtain a resin composition A.

Reference examples 2 and 3 (resin compositions B and C)
Resin compositions B and C were obtained in the same manner as in Reference Example 1 except that the blending ratio of PLA and flame retardant PET was changed as shown in Table 1.

Example 1 (resin composition D)
65 parts by mass of PLA and 35 parts by mass of flame retardant PET are supplied and melt kneading extrusion is performed under the same apparatus and temperature conditions as in Reference Example 1. At that time, a polyethylene glycol dimethacrylate (manufactured by NOF Corporation) is used from the middle of the kneader using a pump A solution prepared by dissolving 1.0 part by mass of (PEGDM) and 1.0 part by mass of di-t-butyl peroxide (manufactured by NOF Corporation) in 2.5 parts by mass of acetyltributylcitric acid as a plasticizer was injected. Then, the discharged resin was cut into pellets to obtain a resin composition D.

Example 2 (resin composition E)
The composition of the solution poured from the middle of the kneader was changed to Example 1 except that PEGDM was 0.5 parts by mass, di-t-butyl peroxide 0.5 parts by mass, and acetyltributyl citrate 1.25 parts by mass. The same operation was performed to obtain a resin composition E.

Example 3 (resin composition F)
The composition of the solution injected from the middle of the kneader was the same as in Example 1 except that PEGDM was 4.0 parts by weight, di-t-butyl peroxide 4.0 parts by weight, and acetyltributyl citrate 10 parts by weight. Operation was performed to obtain a resin composition F.

Example 4 (Resin Composition G)
In the same manner as in Example 1 , melt-kneading extrusion was performed. At that time, as a raw material, in addition to PLA 65 parts by mass and flame retardant PET 35 parts by mass, as a layered silicate, a swellable synthetic fluorinated mica (Somasif MEE manufactured by Co-op Chemical Co., Ltd.) whose interlayer was substituted with dihydroxyethylmethyldodecylammonium ion 4 0.0 parts by mass and 0.5 parts by mass of polycaprolactone diol (PCL2000) (Dacel Chemical Industries Plaxel L220AL) were supplied. The discharged resin was cut into pellets to obtain a resin composition G.

Example 5 (resin composition H)
Except for using 50 parts by mass of PLA and 50 parts by mass of flame-retardant PET, melt-kneading extrusion was performed in the same manner as in Example 1 to obtain a resin composition H.

Example 6 (Resin Composition I)
Except that PLA was 80 parts by mass and flame retardant PET was 20 parts by mass, melt-kneading extrusion was performed in the same manner as in Example 1 to obtain a resin composition I.

Reference example 4 (resin composition J)
Supply 50 parts by mass of PLA and 50 parts by mass of flame-retardant PBS, and perform melt-kneading extrusion at the extrusion head temperature of 190 ° C. and the die outlet temperature of 180 ° C. with the same apparatus as in Reference Example 1, and the discharged resin is in pellet form To obtain a resin composition J.

Comparative Examples 1, 3, 5 (resin compositions K, M, O)
Resin compositions K, M, and O were obtained in the same manner as in Reference Example 1 except that the blending ratio of PLA and flame retardant PET was changed as shown in Table 1.

Comparative Example 2 (resin composition L)
Using a biaxial extruder (Ikegai PCM-30, die diameter: 4 mm × 3 holes, extrusion head temperature: 260 ° C., die outlet temperature: 240 ° C.), 90 parts by mass of PLA and 10 parts by mass of flame-retardant PET were supplied. After melt-kneading extrusion, it was processed into pellets to obtain a resin composition F. Then, a solution consisting of 1.0 part by mass of PEGDM, 1.0 part by mass of di-t-butyl peroxide and 2.5 parts by mass of acetyltributylcitric acid was injected from the middle of the kneader and melt-kneaded and extruded. . The discharged resin was cut into pellets to obtain a resin composition L.

Comparative Example 4 (resin composition N)
Except that 40 parts by mass of PLA and 60 parts by mass of flame retardant PET were used as raw materials, melt-kneading extrusion was performed in the same manner as in Comparative Example 1 to obtain a resin composition N.

Comparative Example 6 (resin composition P)
A resin composition P was obtained in the same manner as in Reference Example 2, except that 35 parts by mass of polyethylene terephthalate (PET, IV0.6) was supplied instead of 35 parts by mass of flame retardant PET.

Comparative Example 7 (resin composition Q)
Resin composition Q was obtained in the same manner as in Example 5 except that 50 parts by mass of PBS was supplied instead of 50 parts by mass of flame retardant PBS.

Comparative Example 8 (resin composition R)
Example 60 parts by mass of PLA, 35 parts by mass of PET, 2 parts by mass of 2-methyl-2,5-dioxo-1-oxa-2-phosphorane manufactured by Hoechst as a phosphorus flame retardant (3000 ppm as phosphorus atom in the composition) 1 to obtain a resin composition R. The resin composition R was molded by using an injection molding machine (IS-80G type manufactured by Toshiba Machine) to obtain various test pieces. At this time, it was melted at a cylinder temperature of 250 ° C., filled into a 20 ° C. mold with an injection pressure of 100 MPa and an injection time of 20 seconds, and cooled for 60 seconds. The obtained molded article was evaluated for flame retardancy, but the flame retardant effect was not observed because the phosphorous compound that was not copolymerized was dispersed (evaluation: x).

The resin compositions A to Q obtained in Examples 1 to 6, Reference Examples 1 to 4 and Comparative Examples 1 to 7 were molded using an injection molding machine (Toshiba Machine IS-80G type), and various test pieces were obtained. Got. At this time, it was melted at a cylinder set temperature of 250 ° C., filled in a mold of 120 ° C. with an injection pressure of 100 MPa and an injection time of 20 seconds, and cooled for 60 seconds. However, since Reference Examples 1 to 3 (resin compositions A to C) could not be molded at a mold temperature of 120 ° C. even with a cooling time of 200 seconds, the mold temperature was set to 20 ° C.

Similarly, the resin compositions J and Q obtained in Reference Example 4 and Comparative Example 7 were similarly melted at a cylinder setting temperature of 180 ° C. and filled into a 40 ° C. mold with an injection pressure of 100 MPa and an injection time of 15 seconds. Various test pieces were obtained by cooling for 2 seconds. Table 1 summarizes the results of various physical property evaluations.

Moreover, about resin composition AJ obtained in Examples 1-6 and Reference Examples 1-4, the housing | casing for PCs was produced using said same molding conditions. The obtained casing was not a problem in practical use.

Resin compositions A to C and J obtained in Reference Examples 1 to 4 are compositions (resins) using polyester in which 2-methyl-2,5-dioxo-1-oxa-2-phosphorane is not copolymerized. Compared to compositions K, M, O, Q), the flame retardancy was significantly improved. In addition, the resin compositions D to I obtained in Examples 1 to 6 have particularly high heat distortion temperatures due to the addition of polyethylene glycol dimethacrylate , and the addition of layered silicate (implementation) The resin composition G) of Example 4 was even higher.

On the other hand, the resin compositions K and L obtained in Comparative Examples 1 and 2 contain a thermoplastic polyester resin copolymerized with 2-methyl-2,5-dioxo-1-oxa-2-phosphorane. Since the amount was low, it was inferior in flame retardancy.

The resin compositions M and N obtained in Comparative Examples 3 and 4 did not show any problems such as processability and physical properties, but the ratio of the biodegradable polyester resin derived from a natural product is low. It is hard to say that it is a resin composition having a low dependence on the above.

The resin compositions O to Q obtained in Comparative Examples 5 to 7 were those using a thermoplastic polyester resin in which 2-methyl-2,5-dioxo-1-oxa-2-phosphorane was not copolymerized. Therefore, it was inferior in flame retardancy.

Claims (7)

Biodegradable polyester resin (A) derived from a natural product (50) to 80% by mass, and thermoplastic polyester resin (B) 50- copolymerized with 2-methyl-2,5-dioxo-1-oxa-2-phosphorane A flame-retardant polyester resin composition obtained by blending 0.01 to 20 parts by mass of polyethylene glycol dimethacrylate (C) with 100 parts by mass of a flame-retardant polyester resin composition comprising 20% by mass. The flame retardant polyester resin composition according to claim 1, wherein the natural product-derived biodegradable polyester resin (A) is polylactic acid. The difficulty according to claim 1 or 2, wherein the thermoplastic polyester resin (B) copolymerized with 2-methyl-2,5-dioxo-1-oxa-2-phosphorane is a biodegradable polyester resin (B1). A flammable polyester resin composition. The flame-retardant polyester resin composition according to claim 3, wherein the biodegradable polyester resin (B1) is a polyester mainly composed of polybutylene succinate. The flame-retardant polyester resin composition obtained by further blending 0.1 to 20 parts by mass of layered silicate (D) per 100 parts by mass of the flame-retardant polyester resin composition according to any one of claims 1 to 4. . The flame-retardant polyester resin composition according to claim 1, wherein the phosphorus content is 750 ppm or more. The molded object formed by shape | molding the flame-retardant polyester resin composition in any one of Claims 1-6.