JP4781714B2 - Impact-resistant biodegradable composition and molded article thereof - Google Patents

Description

  The present invention relates to a composition comprising a plant-derived biodegradable polymer obtained by positively fixing carbon dioxide on the earth and expected to prevent global warming. More specifically, the present invention relates to a composition excellent in impact resistance, heat resistance, etc., comprising a biodegradable aliphatic polyester resin, particularly a (3-hydroxyalkanoate) copolymer and a diene rubber graft copolymer.

  Conventionally, plastic has processability and easy-to-use characteristics, but on the other hand, it has been disposable due to difficulty in reuse and hygiene problems. However, as plastics are used and disposed of in large quantities, the problems associated with landfilling and incineration are becoming more important. Ecosystems due to the shortage of landfills and non-degradable plastics remaining in the environment Impact on the environment, generation of harmful gases during combustion, global warming due to large amounts of combustion heat, etc. In recent years, biodegradable plastics have been actively developed as a solution to the problem of plastic waste.

  These biodegradable plastics are derived from plants and absorb and fix carbon dioxide in the air. Carbon dioxide produced when these plant-derived biodegradable plastics are burned was originally in the air, and carbon dioxide in the atmosphere does not increase. This is called carbon neutral and tends to be regarded as important. Carbon dioxide fixation is expected to be effective in preventing global warming. In particular, the Kyoto Protocol, which imposes carbon dioxide reduction targets, was approved for parliamentary deliberation in Russia in August 2003. The effectiveness of the Protocol has come to a certainty, and carbon dioxide-fixed substances are very attractive and are expected to be used actively.

  On the other hand, aromatic polyester is produced and consumed in large quantities as a general-purpose polymer, but in terms of fixing carbon dioxide and preventing global warming, it is produced from fossil fuels and fixed in the ground. Carbon dioxide that has been converted into carbon is released into the atmosphere, which is not a preferable material in terms of carbon neutrality. For example, Patent Document 1 discloses a polyester resin composition in which an aromatic polyester is blended with a rubber component mainly composed of a conjugated diolefin and a graft copolymer containing acrylonitrile and aromatic vinyl. However, this polyester resin composition is not a preferable material from the viewpoint of carbon neutral.

  Patent Document 2 discloses at least one vinyl monomer selected from aromatic polyester, conjugated diene rubber having a bimodal distribution of rubber particle diameter, or acrylic rubber component selected from styrene, acrylonitrile, and methyl methacrylate. The polyester resin composition which mix | blended the graft copolymer containing is described. Patent Document 3 describes that a small amount of aliphatic polyester is added to the ABS resin to improve the chemical resistance of the ABS resin, but this is insufficient from the viewpoint of biodegradability of the resin.

  Patent Document 4 discloses a thermoplastic resin comprising a polylactic acid polymer and a graft copolymer using a polyorganosiloxane / acrylic composite rubber containing polyorganosiloxane and an alkyl (meth) acrylate rubber. There is a description of the composition.

However, none of the resin composition or thermoplastic resin composition comprising the graft composite rubber and the polyester resin is satisfactory in terms of biodegradability and physical properties of the resin composition.
Japanese Patent Publication No.51-025261 Japanese Patent Publication No. 6-051333 Japanese Examined Patent Publication No. 7-039333 JP 2004-285258 A

  The present invention is to provide a composition and a molded article excellent in impact resistance using a plant-derived biodegradable polymer obtained by positively fixing carbon dioxide on the earth.

  As a result of intensive studies to solve the above problems, the present inventors have obtained a plant-derived biodegradable polymer obtained by positively fixing carbon dioxide on the earth, diene rubber and vinyl monomer. It has been found that a composition excellent in impact resistance can be obtained by blending a graft copolymer obtained by graft polymerization of the body, and the present invention has been completed.

That is, the first of the present invention is a resin composition comprising a biodegradable (3-hydroxyalkanoate) copolymer (A) and a diene rubber graft copolymer (B), the diene rubber The graft copolymer (B) has 50 to 100% by weight of a diene monomer, 50 to 0% by weight of another vinyl monomer copolymerizable therewith, and two or more non-conjugated double bonds in one molecule. A copolymer obtained by graft polymerization of 85 to 10 parts by weight of a vinyl monomer in the presence of 15 to 90 parts by weight of a diene rubber component obtained by copolymerization of 0 to 5% by weight of a polyfunctional monomer. A polymer (a total of 100 parts by weight of a diene rubber component and a vinyl monomer), and the resin composition comprises a (3-hydroxyalkanoate) copolymer (A) and the diene rubber graft copolymer Combined (B) total amount 100 layers % Relative, containing 50 to 99 wt% of (3-hydroxyalkanoate) copolymer (A) and 50 to 1% by weight of the diene rubber graft copolymer (B), wherein (3- (Hydroxyalkanoate) copolymer (A) is composed of (3-hydroxybutyrate) repeating units and (3-hydroxyhexanoate) repeating units [(3-hydroxybutyrate)-(3-hydroxyhexanoate) ]] It is related with the resin composition characterized by being a copolymer .

  The molecular weight of the (3-hydroxyalkanoate) copolymer (A) is preferably 300,000 to 3,000,000.

  In addition, the constitutional ratio of the repeating unit of the [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer is (3-hydroxybutyrate) unit / (3-hydroxyhexanoate) unit. It is preferably a resin composition represented by 99/1 to 80/20 (mol / mol).

  The vinyl monomer in the diene rubber graft copolymer (B) is at least selected from the group consisting of a vinyl cyanide monomer, an aromatic vinyl monomer, an acrylate ester and a methacrylate ester. One vinyl monomer is preferably 70 to 100% by weight and another vinyl monomer copolymerizable with these is 30 to 0% by weight.

  Further, 0.1 to 10 parts by weight of at least one selected from a higher fatty acid amide, a urea derivative, and a sorbitol-based compound is further added as a nucleating agent to 100 parts by weight of the resin composition. Preferably it is a composition.

  Moreover, it is preferable that it is a resin composition characterized by mix | blending 0.1-100 weight part of inorganic fillers with respect to 100 weight part of resin compositions.

  According to the present invention, it is possible to provide a resin composition that can contribute to prevention of global warming and is excellent in physical properties such as impact resistance.

As the biodegradable polymer in the present invention, [−CHR—CH ₂ —CO—O—] (where R is a property capable of decomposing under anaerobic conditions, excellent moisture resistance, and high molecular weight is possible. A biodegradable poly (3-hydroxyalkanoate) copolymer (A) comprising a repeating unit represented by C _n H _{2n + 1} , wherein n is an integer of 1 to 15. Used.

  Representative examples of the biodegradable (3-hydroxyalkanoate) copolymer in the present invention include, for example, [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer, [(3- Hydroxybutyrate)-(3-hydroxyoctanoate)] copolymer, [(3-hydroxybutyrate)-(3-hydroxydecanoate)] copolymer, and the like. Among these, [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymers are preferable, and copolymers produced by microorganisms are more preferable. If necessary, in addition to polyglycolic acid, polylactic acid, poly-3-hydroxybutyric acid, poly-4-hydroxybutyric acid, poly-4-hydroxyvaleric acid, poly-3-hydroxyhexanoic acid or polycaprolactone, aliphatic polyvalent At least one aliphatic polyester such as polyethylene adipate, polyethylene succinate, polybutylene adipate, polybutylene succinate or a copolymer thereof as a polymer mainly composed of carboxylic acid and aliphatic polyhydric alcohol is added. can do.

  Here, the biodegradable [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer is a copolymer mainly composed of 3-hydroxybutyrate and 3-hydroxyhexanoate. It is used as a general term. As long as the copolymer is mainly composed of 3-hydroxybutyrate and 3-hydroxyhexanoate, it may contain other monomer components as described above. Moreover, the polymerization method for obtaining the said copolymer is not specifically limited, Any copolymerization methods, such as random copolymerization, alternating copolymerization, and block copolymerization, may be applied.

  The constitutional ratio of the repeating unit of the biodegradable [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer in the present invention is (3-hydroxybutyrate) unit / (3-hydroxyhexa Noate) units = 99/1 to 80/20 (mol / mol), more preferably 97/3 to 82/18 (mol / mol), and 95/5 to 85/15 ( mol / mol) is more preferable. The constituent ratio of the repeating unit of the [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer may be abbreviated as HH rate.

  The weight average molecular weight of the biodegradable (3-hydroxyalkanoate) copolymer (A) of the present invention is preferably 300,000 to 3,000,000, preferably 400,000 to 2,500,000 in terms of impact resistance and tensile properties. More preferably, 500,000 to 2,000,000 are more preferable. If the weight average molecular weight of the (3-hydroxyalkanoate) copolymer (A) is less than 300,000, the mechanical properties may be inferior, and if it exceeds 3 million, processing may be difficult.

  The method for measuring the weight average molecular weight of the biodegradable (3-hydroxyalkanoate) copolymer (A) is not particularly limited. As an example, chloroform is used as a mobile phase and the system is manufactured by Waters. By using Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK for the column using the GPC system, the molecular weight in terms of polystyrene of the resin composition of the present invention can be obtained.

  The diene rubber graft copolymer (B) in the present invention is a copolymer (85) obtained by graft polymerization of 85 to 10 parts by weight of a vinyl monomer in the presence of 15 to 90 parts by weight of a diene rubber component. The total of the diene rubber component and the vinyl monomer is 100 parts by weight).

  In the present invention, by blending the diene rubber graft copolymer (B), impact strength can be improved while suppressing a decrease in heat resistance of the resin composition.

  The diene rubber component used in the diene rubber graft copolymer (B) of the present invention comprises 50 to 100% by weight of a diene monomer, 50 to 0% by weight of another vinyl monomer copolymerizable therewith, and 1 A rubber obtained by copolymerizing 0 to 5% by weight of a polyfunctional monomer having two or more non-conjugated double bonds in the molecule. Examples of the diene monomer include butadiene and isoprene. Examples of other copolymerizable vinyl monomers include vinyl cyanide monomer, aromatic vinyl monomer, acrylic ester, and methacrylic acid. Examples include esters. As a polyfunctional monomer having two or more non-conjugated double bonds in one molecule, for example, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, allyl methacrylate, allyl acrylate, ethylene glycol dimethacrylate, Examples include diethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, and divinylbenzene. These may be used alone or in combination of two or more. Specific examples of the rubber include butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic ester-butadiene rubber, methacrylic ester-butadiene rubber, and isoprene rubber.

  As a polymerization method of the diene rubber, a solution polymerization method and a bulk polymerization method are also possible, but the ease of graft polymerization, control of the rubber particle size, the graft copolymer and the (3-hydroxyalkanoate) copolymer From the viewpoint of easy blending, emulsion polymerization is preferred.

The emulsion polymerization method can be carried out by a known method, for example, a diene monomer, an aqueous medium, a thermal decomposition type initiator such as potassium peroxide or benzoyl peroxide, FeSO ₄ -reducing agent-organic peroxide, etc. The polymerization can be carried out using a known initiator such as a redox-based initiator and, if necessary, a chain transfer agent such as a mercaptan compound, an emulsifier and the like.

  Examples of the emulsifier used in the polymerization of the diene rubber include, for example, higher fatty acid sodium, higher fatty acid potassium, alkylbenzene sulfonic acid, sodium alkylbenzene sulfonate, alkyl sulfonic acid, sodium alkyl sulfonate, sodium (di) alkyl sulfosuccinate, polyoxy Examples include sodium ethylene nonylphenyl ether sulfonate and sodium alkyl sulfate. These may be used alone or in combination of two or more.

  The polymerization temperature for producing the rubber latex is preferably 10 to 90 ° C, more preferably 30 to 70 ° C, from the viewpoint that the polymerization rate is moderate.

The average particle diameter of the diene rubber in the diene rubber graft copolymer (B) of the present invention is preferably in the range of 0.05 to 1 μm, more preferably 0.1 to 0.6 μm. If the average particle size of the diene rubber is less than 0.05 μm, the impact resistance tends to be insufficient, and if it exceeds 1 μm, the diene rubber latex tends to become unstable.
In addition, the average particle diameter of the diene rubber in the present invention is an average value obtained by measuring the diameter of 50 particles in a transmission electron microscope.

The gel content of the diene rubber component in the diene rubber graft copolymer (B) of the present invention is preferably 50% or more, more preferably 70% or more, from the viewpoint of developing impact resistance.
The gel content in the present invention refers to a part of the rubber latex that is salted out, coagulated, separated, washed, and dried at 40 ° C. for 15 hours to obtain rubber crumbs. The crumb was immersed in toluene at room temperature for 8 hours with stirring, and then centrifuged at 12000 rpm for 60 minutes to measure the dry weight fraction of toluene-insoluble matter.

  In the diene rubber graft copolymer (B) of the present invention, the vinyl monomer used for graft polymerization to the diene rubber is not particularly limited, but preferred specific examples include, for example, acrylonitrile and methacrylonitrile. Vinyl cyanide monomers such as, aromatic vinyl monomers such as styrene, α-methylstyrene, paramethylstyrene, acrylic acid such as methyl acrylate, butyl acrylate, glycidyl acrylate, and hydroxyethyl acrylate Examples include esters, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, glycidyl methacrylate, and hydroxyethyl methacrylate. These may be used alone or in combination of two or more.

  In the present invention, the vinyl monomer is at least one vinyl monomer selected from the group consisting of vinyl cyanide monomers, aromatic vinyl monomers, acrylic esters and methacrylic esters. Those consisting of 70 to 100% by weight and 30 to 0% by weight of other vinyl monomers copolymerizable therewith are preferred from the viewpoint of compatibility with (3-hydroxyalkanoate) copolymerization (A). . As other vinyl monomers copolymerizable with at least one vinyl monomer selected from the group consisting of vinyl cyanide monomers, aromatic vinyl monomers, acrylic esters and methacrylic esters Examples thereof include maleic anhydride, phenylmaleimide, methacrylic acid, and acrylic acid. These may be used alone or in combination of two or more.

  The weight ratio of the diene rubber component to the vinyl monomer in the diene rubber graft copolymer (B) of the present invention is 15/85 to 90/10 as diene rubber particles / vinyl monomer. Preferably, 40 / 60-80 / 20 is more preferable. When the amount of the vinyl monomer used is more than 85/15, the rubber component content is low, and sufficient impact resistance tends not to be exhibited. When the amount is less than 10/90, grafting is performed. When the amount of the monomer is small and it is blended with a thermoplastic resin, the compatibility with the thermoplastic resin which is a matrix resin is deteriorated, and the impact resistance also tends to be lowered.

  The graft polymerization can be performed by using a usual emulsion polymerization method. Usual radical polymerization initiators and chain transfer agents used for the polymerization can be used.

  Furthermore, a so-called free polymer obtained by polymerizing a vinyl monomer with another polymerization machine may be added to the graft polymer, or [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] It can also be added when blending the polymer and the diene rubber graft copolymer. The graft composition and the free polymer composition may be the same or different, but if they are different, a composition compatible with each other is preferred from the viewpoint of physical properties.

  The graft copolymer particles after polymerization may be used by separating the polymer from the emulsion when blended with the [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer. It may be used as it is. As a method for separating the polymer, a usual method, for example, adding a metal salt such as calcium chloride, magnesium chloride, magnesium sulfate or an acid such as hydrochloric acid or sulfuric acid to the emulsion, coagulating, separating, washing, dehydrating and drying the emulsion. And the like. A spray drying method can also be used.

  When the total amount of the (3-hydroxyalkanoate) copolymer (A) and the diene rubber graft copolymer (B) is 100% by weight, the composition of the present invention has 50 to 99% by weight of (3 -Hydroxyalkanoate) copolymer and 50 to 1% by weight of diene rubber graft copolymer, preferably 70 to 85% by weight of (3-hydroxyalkanoate) copolymer and 30 to 15% by weight. % Of diene rubber graft copolymer is more preferable. When the amount of the (3-hydroxyalkanoate) copolymer is less than 50% by weight, the biodegradability tends to deteriorate, and when the amount of the diene rubber graft copolymer is less than 1% by weight. The impact resistance may be inferior.

  In the composition of the present invention, the moldability can be improved by adding a nucleating agent.

  The amount of the nucleating agent used in the present invention is 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin composition comprising the (3-hydroxyalkanoate) copolymer and the diene rubber graft copolymer. Preferably, 0.2-8 weight part is more preferable, and 0.5-5 weight part is further more preferable. If the amount of the nucleating agent used is less than 0.1 parts by weight, the effect of improving the moldability may be insufficient, and if it exceeds 10 parts by weight, the effect may be saturated. It is not preferable.

  Examples of the nucleating agent include higher fatty acid amides, urea derivatives, sorbitol compounds, boron nitride, higher fatty acid salts, aromatic fatty acid salts and the like, and these can be used alone or in combination of two or more. Of these, higher fatty acid amides, urea derivatives, and sorbitol compounds are preferred because of their high effects as nucleating agents.

  Examples of the higher fatty acid amide include behenic acid amide, oleic acid amide, erucic acid amide, stearic acid amide, palmitic acid amide, N-stearyl behenic acid amide, N-stearyl erucic acid amide, ethylenebisstearic acid amide, ethylene Examples include bisoleic acid amide, ethylene biserucic acid amide, ethylene bislauric acid amide, ethylene biscapric acid amide, p-phenylene bis stearic acid amide, polycondensates of ethylenediamine, stearic acid, and sebacic acid, especially behenic acid. Amides are preferred.

  Examples of the urea derivative include bis (stearylureido) hexane, 4,4′-bis (3-methylureido) diphenylmethane, 4,4′-bis (3-cyclohexylureido) diphenylmethane, 4,4′-bis (3- Cyclohexylureido) dicyclohexylmethane, 4,4′-bis (3-phenylureido) dicyclohexylmethane, bis (3-methylcyclohexylureido) hexane, 4,4′-bis (3-decylureido) diphenylmethane, N-octyl-N ′ -Phenylurea, N, N'-diphenylurea, N-tolyl-N'-cyclohexylurea, N, N'-dicyclohexylurea, N-phenyl-N'-tribromophenylurea, N-phenyl-N'-tolylurea N-cyclohexyl-N′-phenylurea Etc. are exemplified, especially bis (stearyl ureido) hexane are preferred.

  Examples of the sorbitol compound include 1,3,2,4-di (p-methylbenzylidene) sorbitol, 1,3,2,4-dibenzylidene sorbitol, 1,3-benzylidene-2,4-p-methylbenzylidene. Sorbitol, 1,3-benzylidene-2,4-p-ethylbenzylidene sorbitol, 1,3-p-methylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-methylbenzylidene-2,4-p-ethylbenzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3,2,4-di (p- Ethylbenzylidene) sorbitol, 1,3,2,4-di (pn-propylbenzylidene) sorbi 1,3,2,4-di (p-i-propylbenzylidene) sorbitol, 1,3,2,4-di (pn-butylbenzylidene) sorbitol, 1,3,2,4-di ( p-s-butylbenzylidene) sorbitol, 1,3,2,4-di (pt-butylbenzylidene) sorbitol, 1,3,2,4-di (p-methoxybenzylidene) sorbitol, 1,3,2 , 4-Di (p-ethoxybenzylidene) sorbitol, 1,3-benzylidene-2,4-p-chlorobenzylidene sorbitol, 1,3-p-chlorobenzylidene-2,4-benzylidenesorbitol, 1,3-p- Chlorbenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3-p-chlorobenzylidene-2,4-p-ethylbenzylidene sorbitol, 1 3-p-methylbenzylidene-2,4-p-chlorobenzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-chlorobenzylidene sorbitol, and 1,3,2,4-di (p-chloro) Benzylidene) sorbitol and the like. Among these, 1,3,2,4-di (p-methylbenzylidene) sorbitol and 1,3,2,4-dibenzylidenesorbitol are preferable.

    In the composition of the present invention, the flexural modulus, heat resistance and the like can be further improved by adding a filler.

  Examples of the filler include carbon black, calcium carbonate, silicon oxide and silicate, zinc white, high-site clay, kaolin, basic magnesium carbonate, mica, talc, quartz powder, diatomaceous earth, dolomite powder, and oxidation. Examples include inorganic fillers such as titanium, zinc oxide, antimony oxide, barium sulfate, calcium sulfate, alumina, and calcium silicate. Of these, mica or talc having a particle size of 0.1 to 30 μm is particularly preferable.

  Examples of the filler include inorganic fibers such as glass fibers and carbon fibers, and organic fibers such as human hair and wool. In addition, natural fibers such as bamboo fiber, pulp fiber, kenaf fiber, other similar plant substitute species, Aoiaceae annual plant, and linden annual plant can also be used. From the viewpoint of reducing carbon dioxide, plant-derived natural fibers are preferable, and kenaf fibers are particularly preferable.

  The amount of the filler used in the composition of the present invention is as follows: physical properties, moldability and price with respect to 100 parts by weight of the resin composition comprising the (3-hydroxyalkanoate) copolymer and the diene rubber graft copolymer. Therefore, 0.1 to 100 parts by weight is preferable, 0.1 to 80 parts by weight is more preferable, and 0.1 to 50 parts by weight is further preferable. When the filler is less than 0.1 parts by weight, the physical properties tend to be less improved, and when it exceeds 100 parts by weight, the impact strength tends to decrease.

  In the composition of the present invention, if necessary, colorants such as pigments and dyes, odor absorbers such as activated carbon and zeolite, fragrances such as vanillin and dextrin, stabilizers such as antioxidants and ultraviolet absorbers, lubricants , Mold release agents, water repellents, antibacterial agents and other secondary additives.

  The said additive may be used independently and may use 2 or more types together.

  In the composition of the present invention, a plasticizer can be used in combination as long as the effects of the present invention are not impaired. By using a plasticizer, it is possible to reduce the melt viscosity during heat processing, especially during extrusion processing, and to suppress a decrease in molecular weight due to shearing heat generation, etc.In some cases, an improvement in crystallization speed can also be expected. Furthermore, when a film or sheet is obtained as a molded product, extensibility and the like can be imparted. Although there is no limitation in particular as a plasticizer, the following can be illustrated. As the plasticizer for the aliphatic polyester-based biodegradable polyester, ether-based plasticizers, ester-based plasticizers, phthalic acid-based plasticizers, phosphorus-based plasticizers and the like are preferable. Agents and ester plasticizers are more preferred. Examples of ether plasticizers include polyoxyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples of ester plasticizers include esters of aliphatic dicarboxylic acids and aliphatic alcohols. Examples of aliphatic dicarboxylic acids include oxalic acid, succinic acid, sebacic acid, and adipic acid. Examples of aliphatic alcohols include monohydric alcohols such as methanol, ethanol, n-propanol, isopropanol, n-hexanol, n-octanol, 2-ethylhexanol, n-dodecanol, stearyl alcohol, ethylene glycol, 1,2- Propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, dihydric alcohols such as diethylene glycol, neopentyl glycol, polyethylene glycol, and glycerin Trimethylolpropane, it may be mentioned polyhydric alcohols pentaerythritol and the like. In addition, two or more kinds of blends selected from copolymers, di-copolymers, tri-copolymers, tetra-copolymers, etc., or homopolymers, copolymers, etc. composed of combinations of two or more of the above polyethers and polyesters. Can be mentioned. Furthermore, esterified hydroxycarboxylic acid and the like are also conceivable. The said plasticizer can use 1 type (s) or 2 or more types.

  A known thermoplastic resin and thermosetting resin can be added to the composition of the present invention within a range that does not impair the effects of the present invention. Typical thermoplastic resins include general-purpose thermoplastic resins such as polyvinyl chloride resins, polystyrene resins, AAS resins, AES resins, polyethylene terephthalate resins, polybutylene terephthalate resins, polycarbonate resins. And general-purpose engineering plastics such as polyamide-based resins. Moreover, epoxy resin etc. are mention | raise | lifted as a typical thermosetting resin.

  In addition, each component used in the present invention can be prepared in advance by preparing a master batch with a combination of a part of the components, and then adding the remaining components to prepare a final composition. Thereby, the compatibility of each component improves and the physical property balance improves.

  The composition of the present invention can be prepared by a known method. For example, as a method of mixing by heating and melting, mixing by mechanical stirring such as a single-screw extruder, a twin-screw extruder, a kneader, a gear pump, a kneading roll, a tank having a stirrer, One example is the application of a static mixer that repeats merging. In the case of heat melting, it is necessary to mix while paying attention to the decrease in molecular weight due to thermal decomposition. There is also a method of obtaining the resin composition of the present invention by removing the solvent after dissolving in a soluble solvent.

  The composition of the present invention can be injection-molded, and may be processed into pellets, blocks, films, and sheets using an extruder molding machine as described above. It may be once pelletized so that the dispersibility of various components is good, and then processed into a film or a sheet by injection molding or an extrusion molding machine. Moreover, it can be formed into a film or a sheet by a calendar molding machine, a roll molding machine, or an inflation molding machine. Moreover, the film and sheet | seat obtained from the resin composition of this invention can be thermoformed by heating, vacuum forming, and press molding. Moreover, hollow molding by a blow molding machine is possible.

  The composition of the present invention becomes a molded product such as various fibers, yarns, ropes, woven fabrics, knitted fabrics, non-woven fabrics, paper, films, sheets, tubes, plates, bars, containers, bags, parts, etc., and is used alone or By combining various fibers, yarns, ropes, woven fabrics, knitted fabrics, non-woven fabrics, paper, films, sheets, tubes, plates, bars, containers, bags, parts, foams, etc. consisting of simple substances other than this composition Used with improved physical properties. The molded product thus obtained can be suitably used in agriculture, fishery, forestry, horticulture, medicine, hygiene, food industry, clothing, non-clothing, packaging, automobiles, building materials, and other fields.

  Next, the composition of the present invention and the molded product thereof will be described in more detail based on examples, but the present invention is not limited to such examples. “Parts” represents parts by weight.

The resins and additives used in the present invention were abbreviated as follows.
PHBH: (3-hydroxybutyrate)-(3-hydroxyhexanoate) copolymer talc: average particle size is about 7 μm (product name: K-1 manufactured by Nippon Talc),
Mica: average particle size is about 20 μm (manufactured by Yamaguchi Mica, trade name: A-41S)
Antioxidant: Hindered phenol antioxidant (Ciba Geigy, trade name: Irganox-1010)
MMA: methyl methacrylate BA: butyl acrylate ST: styrene AN: vinyl cyanide SFS: sodium formaldehyde sulfosulfate dihydrate (Longalite)
QHPO: cumene hydroperoxide

  The evaluation methods in the examples are as follows.

<Measurement of notched Izod impact value (impact resistance)>
Based on JIS K7110, an Izod impact value with a notch was measured using an Izod impact tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.).

<Method of measuring heat distortion temperature (HDT)>
Based on JIS K7207 (A method), the thermal deformation temperature at a load of 0.45 MPa was measured.

(Production example)
(1) Synthesis of [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer (PHBH) (A) PHBH has a PHA synthase gene derived from Aeromonas caviae as a microorganism in Alcaligenes eutrophus. PHBH produced using the introduced Alcaligenes eutrophus AC32 (J. Bacteriol., 179, 4821 (1997)) with appropriate adjustment of raw materials and culture conditions, with HH rates of 7 mol% and 12 mol%, and Mw ( The weight average molecular weight was about 600,000.

(2) Production of diene rubber graft copolymer (B) (R-1) Rubber synthesis 100 L polymerization machine, 90 parts pure water 0.3 parts potassium persulfate, 1.0 part potassium phosphate, hydroxylated 0.1 part of potassium and 0.2 part of t-dodecyl mercaptan were charged.
Next, after the air in the polymerization machine was removed with a vacuum pump, 2.0 parts of potassium rosinate and 100 parts of butadiene were charged.
The temperature of the system was raised to 50 ° C. to initiate polymerization. Further, as the polymerization progressed, the temperature of the system was increased at 2.5 ° C./hour, and then maintained at 75 ° C., and the conversion rate was 92% after 50 hours of reaction time.
After completion of the reaction, unreacted butadiene was removed by steam distillation to obtain a polybutadiene latex (R-1).
The gel content and average particle size of the latex (R-1) are 75% and 0.23 μm (according to transmission electron micrograph observation).

(R-2) Synthetic water of rubber 200 parts, sodium oleate 1.5 parts, ferrous sulfate (FeSO ₄ .7H ₂ O) 0.002 parts, ethylenediaminetetraacetic acid 2Na salt 0.005 parts, 0.2 parts of SFS, 0.2 parts of tripotassium phosphate, 75 parts of butadiene, 25 parts of styrene, 2.0 parts of divinylbenzene and 0.1 part of diisopropylbenzene hydroperoxide were charged into a 10 L polymerization vessel equipped with a stirrer. Polymerization was carried out at 0 ° C. for 15 hours to obtain a rubber latex (R-2) having a polymerization conversion rate of 98% and a weight average particle size of 0.07 μm.

[Production of Graft Copolymers G-1 to G-4]
Using the diene rubber latex R-1 or R-2 in the number of parts shown in Table 1, water is added to make 220 parts of latex, and the mixture is kept at 60 ° C. with stirring in a nitrogen stream, and the SFS is set to 0.00. After the addition of 2 parts, a mixture of vinyl monomers shown in Table 1 is continuously dropped over the time shown in Table 1, and then kept at 60 ° C. for 1.5 hours to carry out graft polymerization on the diene rubber. Completed.
To the obtained diene rubber graft copolymer latex, 0.3 part of an antioxidant and 1.5 parts of calcium chloride are added, coagulated, separated, washed, dried, and powdered diene rubber graft copolymer. A polymer was obtained.

[Production of Free Polymer F-5]
Without using a diene rubber latex, with 220 parts of water, with stirring in a nitrogen stream, kept at 60 ° C., 2 parts of sodium alkylbenzene sulfonate, ferrous sulfate (FeSO ₄ / 7H ₂ O). After adding 0015 parts, ethylenediaminetetraacetic acid · 2Na salt 0.00375 parts and 0.2 parts SFS, a mixture of vinyl monomers shown in Table 1 was continuously added dropwise over 8 hours, and then 60 ° C. For 1.5 hours to complete the polymerization of the free polymer.

(Examples 1-6)
A mixture of (3-hydroxybutyrate)-(3-hydroxyhexanoate) copolymer, graft copolymer, filler, nucleating agent and antioxidant at the blending ratio shown in Table 2 Using an extrusion molding machine (manufactured by Nippon Steel Works, TEX33, Φ33 mm), melt-kneading was performed at a cylinder setting temperature of 170 ° C. to obtain resin composition pellets.
The obtained resin composition pellets were about 10 mm × 120 mm × 6 using an injection molding machine (manufactured by Toshiba) with a clamping pressure of 75 tons under the conditions of a set resin temperature of 140 ° C. and a set mold temperature of 40 ° C. A molded article having a thickness of 4 mm was injection-molded, and the IZOD impact value and HDT were measured. The results are shown in Table 2.

(Comparative Examples 1-2)
A resin composition was obtained by the same operation as in Example 1 at the blending ratio shown in Table 2. Said evaluation was performed with respect to the obtained resin composition, and the result was shown in Table 2. In addition, the physical properties of the system to which no graft copolymer was added were also examined.

  From the results of Table 2, although the HDT value is slightly lower in Examples 1 to 6, which are molded articles of the resin composition of the present invention using a diene rubber graft copolymer, the IZOD impact value is clear. It can be seen that the balance between impact resistance and heat resistance is excellent.

  The composition of the present invention becomes a molded article such as paper, film, sheet, tube, plate, bar, container, bag, component, etc., and is used alone or various fibers made of a single substance other than this composition. It is used by improving the physical properties of single body by compounding with yarn, rope, woven fabric, knitted fabric, non-woven fabric, paper, film, sheet, tube, plate, bar, container, bag, component, foam and the like. The molded product thus obtained can be suitably used in agriculture, fishery, forestry, horticulture, medicine, hygiene, food industry, clothing, non-clothing, packaging, automobiles, building materials, and other fields.

Claims (6)

A resin composition comprising a biodegradable (3-hydroxyalkanoate) copolymer (A) and a diene rubber graft copolymer (B), wherein the diene rubber graft copolymer (B) is: Polyfunctional monomer 0 to 5 having 50 to 100% by weight of diene monomer, 50 to 0% by weight of other vinyl monomer copolymerizable therewith, and two or more non-conjugated double bonds in one molecule A copolymer (diene rubber component and vinyl) obtained by graft polymerization of 85 to 10 parts by weight of a vinyl monomer in the presence of 15 to 90 parts by weight of a diene rubber component obtained by copolymerization in weight percent. The total amount of the system monomers is 100 parts by weight), and the resin composition has a total amount of 100 weights of the (3-hydroxyalkanoate) copolymer (A) and the diene rubber graft copolymer (B). % To 50-9 Contains by weight percent (3-hydroxyalkanoate) copolymer (A) and 50 to 1% by weight of the diene rubber graft copolymer (B), wherein the (3-hydroxyalkanoate) copolymer ( A) is a [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer composed of (3-hydroxybutyrate) repeating units and (3-hydroxyhexanoate) repeating units. A resin composition characterized by the above. The (3-hydroxyalkanoate) copolymer molecular weight of (A) is a 300,000 to 3,000,000 weight-average molecular weight, according to claim 1 resin composition. The constitutional ratio of the repeating unit of the [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer is (3-hydroxybutyrate) unit / (3-hydroxyhexanoate) unit = 99 / It is represented by 1-80 / 20 (mol / mol), The resin composition of Claim 1 or 2 characterized by the above-mentioned. The vinyl monomer in the diene rubber graft copolymer (B) is at least one selected from the group consisting of vinyl cyanide monomer, aromatic vinyl monomer, acrylic ester and methacrylic ester. The vinyl monomer according to any one of claims 1 to 3 , comprising 70 to 100% by weight of a vinyl monomer and 30 to 0% by weight of another vinyl monomer copolymerizable therewith. Resin composition. The resin composition further comprises 0.1 to 10 parts by weight of at least one selected from a higher fatty acid amide, a urea derivative and a sorbitol compound as a nucleating agent with respect to 100 parts by weight of the resin composition. Item 5. The resin composition according to any one of Items 1 to 4 . The resin composition according to any one of claims 1 to 5 , further comprising 0.1 to 100 parts by weight of a filler with respect to 100 parts by weight of the resin composition.