JP4958386B2 - Resin composition, molded article, and method for producing resin composition - Google Patents

Description

  The present invention relates to a biodegradable resin composition, molded article, electrical product, and method for producing a resin composition.

  Conventionally, various synthetic resin materials have been developed and provided, and the amount of use in various industrial fields increases year by year, and the production amount reaches nearly 10 million tons per year. As a result, the amount of synthetic resin discarded has increased, and its treatment has become a major social problem. If the discarded resin is incinerated as it is, harmful gas may be generated or the incinerator may be damaged by a large amount of combustion heat, which places a heavy load on the environment.

  As a disposal method of the waste resin known so far, for example, there is a method of incinerating or landfilling a resin whose molecular weight is reduced by thermal decomposition or chemical decomposition. However, since the incineration process involves the discharge of carbon dioxide, there is a risk of causing global warming. In addition, when sulfur, nitrogen, halogen, or the like is contained in the incineration resin, incineration treatment contributes to air pollution due to harmful exhaust gas. On the other hand, when the resin is landfilled, most of the currently used resins remain as they are without being decomposed for a long time, which causes soil contamination.

  Therefore, in order to deal with such problems, bio-degradable natural materials such as biocellulose and starch-based plastics, low-substituted cellulose esters, natural polyesters by microorganisms, aliphatic polyester resins by chemical synthesis, etc. As a plastic, its manufacture and use are being studied. Since biodegradable resins are biochemically decomposed into carbon dioxide and water by microorganisms, etc., even when discarded into the natural environment, they are easily decomposed to lower molecular weight and become harmless to the environment. Change. Therefore, by using a biodegradable resin, it is possible to reduce adverse effects on the global environment due to disposal. For these reasons, practical use has been promoted for disposable products mainly made up of daily miscellaneous goods, sanitary goods, play goods and the like.

As described above, conventional biodegradable resins are superior in terms of safety against the natural environment, but when biodegradable resins are applied to practical products such as housings of electrical products and electronic devices, for example. In addition to moderate biodegradability, various performances such as heat resistance, mechanical strength, and storage characteristics (durability under constant temperature and humidity conditions) are required. For example, for materials used in small audio products, the heat resistance specification is 3-7 under the conditions that the storage elastic modulus at 100 ° C. is 1 × 10 ⁸ Pa or more and the storage characteristics are 30 ° C. and the relative humidity is 80%. It is necessary to maintain physical properties such as strength over the years.

In view of this, various studies have been conducted to give biodegradable resins physical properties suitable for practical molded products. For example, a method for improving biodegradability and moldability by blending an appropriate amount of a biodegradable resin exhibiting rubber-like properties having a low glass transition point with an aliphatic polyester resin that is a typical example of a biodegradable polymer (for example, , See Patent Document 1), a method of improving mechanical strength by adding calcium carbonate and / or magnesium carbonate to an aliphatic polyester resin (see, for example, Patent Document 2), melting poly-3-hydroxybutyric acid Thereafter, a method for improving the biodegradability by rapidly solidifying and forming a molded body having a crystallinity of less than 50% (for example, see Patent Document 3) has been proposed.
JP-A-3-290461 JP-A-4-146852 JP-A-4-325526

  However, it is assumed that the molded article made of the biodegradable resin of Patent Documents 1 to 3 described above is mainly used for films, packaging materials, and the like, and there is a problem that mechanical strength and the like are not sufficient. .

Further, with the expansion of the application range of biodegradable resins, further improvement in heat resistance is required. In particular, in recent years, replacement of synthetic resins used for casings and structural materials of extremely large amounts of electrical products with biodegradable resins has been studied. Compared to disposable items, etc., where heat-resistant resin is used, extremely strict heat resistance specifications must be satisfied. For example, the specification of heat resistance in a small audio product has a storage elastic modulus at 100 ° C. of 1 × 10 ⁸ Pa or more, and it is difficult to satisfy such heat resistance with the above-described biodegradable resin. .

Therefore, the present invention has been proposed in view of such a conventional situation, and provides a resin composition capable of realizing excellent mechanical strength and heat resistance, a manufacturing method thereof, and a molded article of the resin composition. The purpose is to do.

The present inventors have, as a result of various studies for improving the physical properties of the biodegradable resin, typical relative aliphatic polyester resin is a biodegradable plastic, derivatives of cellulose der Rue ester aroma powder In addition to obtaining the knowledge that the heat resistance of the molded product of the biodegradable resin composition can be improved by blending, the compound resin machine is further blended with a hydrolysis inhibitor. As a result, the inventors have obtained the knowledge that the mechanical strength can be increased as compared with the prior art, and have completed the present invention.

That is, the resin composition according to the present invention comprises at least one aliphatic polyester resin exhibiting biodegradability, esterified starch, and hydrolysis of the above-described aliphatic polyester resin and / or esterified starch exhibiting biodegradability. The aliphatic polyester resin is polylactic acid and contains 25 to 60 parts by weight of the esterified starch with respect to 100 parts by weight of the polylactic acid .

Further, the molded article according to the present invention comprises at least one kind of aliphatic polyester resin exhibiting biodegradability, esterified starch, and hydrolysis of the above-described aliphatic polyester resin and / or esterified starch exhibiting biodegradability. The aliphatic polyester resin is polylactic acid, and a resin composition containing 25 to 60 parts by weight of the esterified starch with respect to 100 parts by weight of the polylactic acid is molded. It becomes.

In addition, the method for producing a resin composition according to the present invention includes at least one kind of aliphatic polyester resin exhibiting biodegradability, esterified starch, and the above aliphatic polyester resin and / or esterified starch exhibiting biodegradability. The aliphatic polyester resin is a polylactic acid containing 25 to 60 parts by weight of the esterified starch with respect to 100 parts by weight of the polylactic acid .

Aliphatic polyester resins have the property of softening rapidly in the vicinity of the glass transition point, but by adding esterified starch to this aliphatic polyester resin, this property can be compensated and heat resistance can be improved. it can. Further, the resin containing the aliphatic polyester resin and esterified starch, by adding suppressing hydrolysis inhibitor hydrolysis of the aliphatic polyester resin and / or esterified starches indicating the biodegradable, The hydrolysis rate of the resin exhibiting biodegradability is delayed, and as a result, high mechanical strength can be maintained over a long period of time compared to the case where no hydrolysis inhibitor is added. As described above, since the resin composition of the present invention contains a hydrolysis inhibitor with respect to the biodegradable resin of the specific combination of the aliphatic polyester resin and the esterified starch , both the heat resistance and the mechanical strength are satisfied. can do.

According to the present invention, an aliphatic polyester resin and esterified starch are used in combination as a biodegradable resin, and by adding a hydrolysis inhibitor in these biodegradable resins, high heat resistance and It is possible to provide a resin composition that exhibits mechanical strength and has little adverse effect on the natural environment at the time of disposal.

Further, according to the present invention, by molding a resin composition containing an aliphatic polyester resin and esterified starch as a biodegradable resin and a hydrolysis inhibitor of these biodegradable resins, for example, a housing of an electrical product. It is possible to provide a molded article that exhibits high heat resistance and mechanical strength that can be used for body materials, and that has little adverse effect on the natural environment when discarded.

  In addition, according to the present invention, there is provided a method for producing a resin composition that exhibits high heat resistance and mechanical strength that can be used, for example, as a casing material for electrical products, and that has little adverse effect on the natural environment when discarded. can do.

Hereinafter, the method of resin composition and its preparation The present invention will be described in detail with the molded article.

  The resin composition of the present invention has a biodegradable aliphatic polyester resin as a biodegradable polymer compound and a biodegradable polysaccharide, and a hydrolysis rate of the biodegradable polymer compound. And a hydrolysis inhibitor to be adjusted. Here, a polymer compound exhibiting biodegradability (hereinafter sometimes referred to as “biodegradable polymer compound”) refers to a low molecular compound, that is, finally water after microorganisms are involved in nature after use. And a compound that decomposes into carbon dioxide (Biodegradable Plastics Research Society, ISO / TC-207 / SC3).

  In the resin composition of the present invention, an aliphatic polyester resin exhibiting biodegradability excellent in mixing property and mass productivity is used. As the aliphatic polyester resin, polylactic acid such as poly-L-lactic acid (PLLA), a random copolymer of L-lactic acid and D-lactic acid, or a derivative thereof is more preferable. Of course, other aliphatic polyesters, for example, polycaprolactone, polyhydroxybutyric acid, polyhydroxyvaleric acid, polyethylene succinate, polybutylene succinate, polybutylene adipate, polymalic acid, polyglycolic acid, polysuccinic acid ester, oxalic acid Esters, polybutylene diglycolates, polydioxanones, microbial synthetic polyesters, copolymers containing at least one of these, and the like can also be used. Here, examples of the microbial synthetic polyester include 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), or a copolymer thereof. As the aliphatic polyester resin, the above-mentioned compounds or the like may be used alone or in combination of two or more.

  The aliphatic polyester resin exhibiting biodegradability used in the present invention can be produced according to a known method. For example, the biodegradable polyester can be produced by a method such as lactide method, polycondensation of polyhydric alcohol and polybasic acid, or intermolecular polycondensation of hydroxycarboxylic acid having a hydroxyl group and a carboxyl group in the molecule. Yes, but not limited to.

  Examples of the polysaccharide contained in the resin composition include cellulose, starch, chitin, chitosan, dextran, or a derivative thereof, or a copolymer containing at least one of them. As the polysaccharide, the above-mentioned compounds or the like may be used alone or in combination of two or more. In addition, various plasticizers can be added to the polysaccharide to impart thermoplasticity.

  Examples of the cellulose derivatives include esterified cellulose. Specific esterified celluloses include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate, cellulose nitrate, cellulose sulfate, and cellulose phosphate. A copolymer containing at least one of inorganic acid ester, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, cellulose nitrate acetate, and the like, and cellulose ester derivatives such as polycaprolactone-grafted cellulose acetate Etc. can be illustrated. These esterified celluloses can be used alone or in admixture of two or more.

  The esterified cellulose used in the present invention can be produced according to a known method. Esterified cellulose can be produced by completely acetylating cellulose and then partially saponifying it. Furthermore, a plasticizer is added to the produced esterified cellulose in order to improve moldability. The plasticizer is not particularly limited as long as it has good biodegradability and an excellent plasticizing effect, but is preferably a low molecular weight ester plasticizer, and more preferably a phosphate ester or a carboxylate ester.

  Specific examples of the phosphate ester include triphenyl phosphate (TPP) and tricresyl phosphate (TCP), cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, and the like.

  Specific examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP) dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate, (DPP) and diethyl hexyl phthalate (DEHP). Examples of the citrate ester include triethyl O-acetylcitrate (OACTE), tributyl O-acetylcitrate (OACTB), acetyltriethyl citrate, acetyltributyl citrate and the like.

  Other examples of the carboxylic acid ester include various trimellitic esters such as butyl oleate, methylacetyl ricinoleate, and dibutyl sebacate.

  Glycolic acid esters can also be used. Specific examples include triacetin, tributyrin, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, and butyl phthalyl butyl glycolate. Of these, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diethyl hexyl phthalate, triacetin, ethyl phthalyl ethyl glycolate and the like are preferable. These plasticizers may be used alone or in combination of two or more.

  The starch-substituted derivative which is a modified starch can be produced according to a known method. The basic method for producing a starch-substituted derivative, which is a modified starch, is esterification, and the starch ester produced by these reactions has been known as an aqueous reaction esterified starch (starch ester) having a low substitution degree. It has been. ("Starch Science Handbook" (July 20, 1997) Asakura Shoten Co., Ltd. p550) In addition, regarding starch esters with a high degree of substitution, acid anhydrides are reacted in pyridine using dimethylaminopyridine or an alkali metal as a catalyst. Method ("Starch Chemistry & Technology" by Whistler, published by Academic Press, p332-336), a method in which an alkali metal hydroxide aqueous solution is used as a catalyst in an acid anhydride at a high temperature of 100 ° C or higher (special table) No. 5-508185, Die Starke 1972, March p73, etc.) and “Method of reacting in vinyl organic ester in non-aqueous organic solvent” (see JP-A-8-188601), etc. It has been known. Further, a natural fatty acid or the like may be added to starch as a raw material, followed by etherification or graft polymerization reaction to obtain a starch substituted derivative as a modified starch. Furthermore, in order to give these starch substituted derivatives (starch esters) moldability (for example, injection molding, extrusion molding, stretch molding, etc.) like ordinary thermoplastics (thermoplastic resins), a plasticizer is added. It may be added.

  Further, it may be a starch-substituted derivative (see, for example, JP 2000-159802 A) that can be thermoplasticized without adding a plasticizer or by using a small amount of plasticizer. The above contents are obtained by replacing the hydrogen of the reactive hydroxyl group on the same starch molecule with a long-chain hydrocarbon-containing group having 6 to 24 carbon atoms and a short-chain hydrocarbon-containing group (long-chain / short-chain hydrocarbon-containing group). ), And the substitution degree of the long-chain hydrocarbon-containing group and the short-chain hydrocarbon-containing group is adjusted, and the starch-substituted derivative having self-thermoplasticity while maintaining biodegradability. Is.

  As a plasticizer added to starch such as starch ester, a plasticizer highly compatible with starch ester is preferable, and the following various plasticizers (mainly ester type) can be used. For example, phthalate esters such as phthalates such as dimethyl, diethyl, and dibutyl, and ethyl phthaloyl ethyl glycolate and butyl phthaloyl butyl glycolate, and aliphatic esters such as oleic acid, adipic acid, and stearic acid. In the case of polyhydric alcohol esters such as methyl, ethyl, butyl and isopropyl, sultrol acetate, diethyl glycol benzoate, triacetin (triacetylglycerin), tripropionine (tripropionylglycerin), acetyldiglycerin, etc. Methyl acid, acetyl triethyl citrate, etc., phosphate ester, tributyl phosphate, triphenyl phosphate, etc., epoxy plasticizer, epoxidized soybean oil, epoxidized castor oil, alkyl epoxy Among polymer plasticizers such as tearates, various liquid rubbers, terpenes, linear polyesters, etc. Among these, ester type plasticizers such as triethyl acetyl citrate, ethyl phthaloyl ethyl glycolate, triacetin, tripropionine, etc. Preferably used.

The hydrolysis inhibitor used in the present invention is not particularly limited as long as it is an additive that suppresses hydrolysis of the biodegradable polymer compound. Examples of the hydrolysis inhibitor include compounds having reactivity with active hydrogen in a biodegradable polymer compound. By adding the above compound, the amount of active hydrogen in the biodegradable polymer compound can be reduced, and active hydrogen can be prevented from catalytically hydrolyzing the biodegradable polymer chain. Here, active hydrogen is hydrogen in a bond (N—H bond or O—H bond) of oxygen, nitrogen or the like and hydrogen, and such hydrogen is in a bond of carbon and hydrogen (C—H bond). Reactivity is higher than hydrogen. More specifically, for example, hydrogen in a carboxyl group: —COOH, a hydroxyl group: —OH, an amino group: —NH ₂ , an amide bond: —NHCO— or the like in the biodegradable polymer compound may be mentioned.

  As the compound having reactivity with active hydrogen in the biodegradable polymer compound, a carbodiimide compound, an isocyanate compound, an oxazoline compound, and the like are applicable. In particular, a carbodiimide compound is preferable because it can be melt-kneaded with a biodegradable polymer compound, and hydrolysis can be further suppressed with a small amount of addition.

  The carbodiimide compound is a compound having one or more carbodiimide groups in the molecule, and also includes a polycarbodiimide compound. As a method for producing the carbodiimide compound, for example, as a catalyst, for example, O, O-dimethyl-O- (3-methyl-4-nitrophenyl) phosphorothioate, O, O-dimethyl-O- (3-methyl-4) -(Methylthio) phenyl) phosphorothioate, organic phosphorus compounds such as O, O-diethyl-O-2-isopropyl-6-methylpyrimidin-4-ylphosphorothioate, or, for example, rhodium complex, titanium complex, tungsten complex, palladium complex A method for producing various polymer isocyanates by decarboxylation polycondensation in a solvent-free or inert solvent (for example, hexane, benzene, dioxane, chloroform, etc.) at a temperature of about 70 ° C. or higher using an organometallic compound such as be able to.

  Examples of the monocarbodiimide compound contained in this carbodiimide compound include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, diphenylcarbodiimide, naphthylcarbodiimide, and among them, particularly industrially available. Easy dicyclohexylcarbodiimide and diisopropylcarbodiimide are preferred.

  Examples of the isocyanate compound that is reactive with active hydrogen in the biodegradable polymer compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, and p-phenylene diisocyanate. 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4 '-Biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6-hexame Diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, Examples include 4,4′-dicyclohexylmethane diisocyanate or 3,3′-dimethyl-4,4′-dicyclohexylmethane diisocyanate.

  The said isocyanate compound can be easily manufactured by a well-known method, and a commercial item can be used suitably. As commercially available polyisocyanate compounds, aromatic isocyanate adducts such as coronate (manufactured by Nippon Polyurethane; hydrogenated diphenylmethane diisocyanate) or myrionate (manufactured by Nippon Polyurethane) can be used. In particular, when the composition according to the present invention is produced by melt-kneading, the use of a polyisocyanate compound in which a solid substance, for example, an isocyanate group is blocked with a masking agent (polyhydric aliphatic alcohol, aromatic polyol, etc.) from a liquid is used. preferable.

  Examples of the oxazoline-based compound that is reactive with active hydrogen in the biodegradable polymer compound include 2,2′-o-phenylenebis (2-oxazoline) and 2,2′-m-phenylene. Bis (2-oxazoline), 2,2'-p-phenylenebis (2-oxazoline), 2,2'-p-phenylenebis (4-methyl-2-oxazoline), 2,2'-m-phenylenebis (4-methyl-2-oxazoline), 2,2′-p-phenylenebis (4,4′-dimethyl-2-oxazoline), 2,2′-m-phenylenebis (4,4′-dimethyl-2) -Oxazoline), 2,2'-ethylenebis (2-oxazoline), 2,2'-tetramethylenebis (2-oxazoline), 2,2'-hexamethylenebis (2-oxazoline), 2,2'- Octamethylene Bis (2-oxazoline), 2,2′-ethylenebis (4-methyl-2-oxazoline), 2,2′-diphenylenebis (2-oxazoline), or the like can be given. Moreover, the said hydrolysis inhibitor may use the said compound individually or in mixture of 2 or more types.

  The type and blending amount of the hydrolysis inhibitor are not particularly limited, but the biodegradation rate of the molded article and thus the mechanical strength can be adjusted by appropriately adjusting the type and blending amount of the hydrolysis inhibitor. Therefore, it may be determined according to the target product. The specific blending amount of the hydrolysis inhibitor is preferably 15 parts by weight or less, more preferably 10 parts by weight or less with respect to 100 parts by weight of the aliphatic polyester resin.

  The manufacturing method of the resin composition of this invention is not specifically limited, You may use a well-known method. For example, a method of producing an aliphatic polyester resin by melt-kneading polysaccharides such as esterified cellulose and starch-substituted derivatives such as esterified starch and a hydrolysis inhibitor is preferable.

  The production method by melt kneading is performed by adding and mixing a polysaccharide resin and a hydrolysis inhibitor before or when the aliphatic polyester resin exhibiting biodegradability is melted. At this time, the polysaccharide resin and the hydrolysis inhibitor may be added simultaneously or individually. Moreover, when adding individually, any may be added first. In addition, after melting an aliphatic polyester resin exhibiting biodegradability, either a polysaccharide resin or a hydrolysis inhibitor is added and mixed, and then the resulting composition is melted again to obtain a hydrolysis inhibitor or A method of adding and mixing any remaining components of the saccharide resin is also included.

  In the resin composition according to the present invention, other additives for improving performance can be appropriately used as long as the object of the present invention is not impaired. Examples of other additives include, but are not limited to, reinforcing materials, antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, waxes, colorants, crystallization accelerators, and the like. These additives may be used alone or in combination of two or more.

  Examples of the reinforcing material include fillers such as inorganic fillers and organic fillers. Examples of the inorganic filler include carbon, silicon dioxide, metal oxide fine particles such as alumina, silica, magnesia, and ferrite, silicates such as talc, mica, kaolin, and zeolite, barium sulfate, calcium carbonate, and fullerene. Examples thereof include fine particles. Examples of inorganic fillers include glass microbeads, carbon fibers, chalk, quartz such as novoculite, asbestos, feldspar, mica, and the like. Examples of the organic filler include an epoxy resin, a melamine resin, a urea resin, an acrylic resin, a phenol resin, a polyimide resin, a polyamide resin, a polyester resin, and a Teflon (registered trademark) resin. Of these, carbon and silicon dioxide are preferable. However, the reinforcing material is not limited to the above, and any generally used fillers such as inorganic fillers and organic fillers can be used. Further, the reinforcing material may be used alone or in combination of two or more.

Examples of the antioxidant include phenol-based, amine-based, phosphorus-based, sulfur-based, hydroquinone-based, and quinoline-based antioxidants. Phenol antioxidants include hindered phenols such as 2,6-di-t-butyl-p-cresol, 1,3,5-trimethyl-2,4,6-tris (3,5-di- -T-butyl-4-hydroxybenzyl) benzene, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-methylenebis (2,6-di-t-butylphenol), 4, C ₂₋ such as 4′-butylidenebis (3-methyl-6-tert-butylphenol), 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] ₁₀ alkylenediol - bis [3- (3,5-di - branched C _3-6 alkyl-4-hydroxyphenyl) propionate], for example, triethylene glycol - bis [3- (3-t-butyl - - methyl-4-hydroxyphenyl) propionate] and the like di- or Toriokishi C _2-4 alkylene diol - bis [3- (3,5-di - branched C _3-6 alkyl-4-hydroxyphenyl) propionate], such as glycerin C _3-8 alkanetriol-bis [3- (3,5-di-branched C _3-6 alkyl-4] such as tris [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] -Hydroxyphenyl) propionate], for example C _4-8 alkanetetraol tetrakis [3- (3,5-, 5-pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]). Di-branched C _3-6 alkyl-4-hydroxyphenyl) propionate], for example n-octadecyl-3- (4 ′, 5′-di-t-butyl) Ruphenol) propionate, n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-t-butylphenol) propionate, stearyl-2- (3,5-di-t-butyl-4-hydroxyphenol) ) Propionate, distearyl-3,5-di-t-butyl-4-hydroxybenzylphosphonate, 2-t-butyl-6- (3-t-butyl-5-methyl-2-hydroxybenzyl) -4-methyl Phenyl acrylate, N, N′-hexamethylene bis (3,5-di-tert-butyl-4-hydroxy-hydrocymamide), 3,9-bis {2- [3- (3-tert-butyl- 4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 4, Examples thereof include 4′-thiobis (3-methyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenol) butane, and the like.

  Examples of amine-based antioxidants include phenyl-1-naphthylamine, phenyl-2-naphthylamine, N, N′-diphenyl-1,4-phenylenediamine, or N-phenyl-N′-cyclohexyl-1,4- Examples include phenylenediamine.

  Examples of phosphorus antioxidants include triisodecyl phosphite, triphenyl phosphite, trisnonylphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, 2,2-methylenebis (4,6-di-). t-butylphenyl) octyl phosphite, 4,4′-butylidenebis (3-methyl-6-tert-butylphenyl) ditridecyl phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris ( 2-t-butyl-4-methylphenyl) phosphite, tris (2,4-di-t-amylphenyl) phosphite, tris (2-t-butylphenyl) phosphite, bis (2-t-butylphenyl) ) Phenyl phosphite, tris [2- (1,1-dimethylpropyl) -phenyl ] Phosphite, tris [2,4- (1,1-dimethylpropyl) -phenyl] phosphite, tris (2-cyclohexylphenyl) phosphite, tris (2-t-butyl-4-phenylphenyl) phosphite, etc. Phosphite compounds; triethylphosphine, tripropylphosphine, tributylphosphine, tricyclohexylphosphine, diphenylvinylphosphine, allyldiphenylphosphine, triphenylphosphine, methylphenyl-p-anisylphosphine, p-anisyldiphenylphosphine, p-tolyl Diphenylphosphine, di-p-anisylphenylphosphine, di-p-tolylphenylphosphine, tri-m-aminophenylphosphine, tri-2,4-dimethylphenylphosphine, tri-2,4,6 Trimethylphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tri-o-anisylphosphine, tri-p-anisylphosphine, or 1,4-bis (diphenylphosphine) And phosphine compounds such as fino) butane.

Examples of the hydroquinone antioxidant include 2,5-di-t-butylhydroquinone, and examples of the quinoline antioxidant include 6-ethoxy-2,2,4-trimethyl-1,2. -Dihydroquinoline etc. are mentioned, As a sulfur type antioxidant, dilauryl thiodipropionate, distearyl thiodipropionate etc. are mentioned, for example. Among them, preferable antioxidants include phenolic antioxidants (particularly hindered phenols), for example, polyol-poly [(branched C _3-6 alkyl group and hydroxy group-substituted phenyl) propionate] and the like. The antioxidants may be used alone or in combination of two or more.

  Examples of the heat stabilizer include nitrogen-containing compounds such as basic nitrogen-containing compounds such as polyamide, poly-β-alanine copolymer, polyacrylamide, polyurethane, melamine, cyanoguanidine, and melamine-formaldehyde condensate; organic carboxylic acid Metal salts (calcium stearate, calcium 12-hydroxystearate, etc.), metal oxides (magnesium oxide, calcium oxide, aluminum oxide, etc.), metal hydroxides (magnesium hydroxide, calcium hydroxide, aluminum hydroxide, etc.), metal carbonates Examples thereof include alkali or alkaline earth metal-containing compounds such as salts; zeolite; or hydrotalcite. In particular, alkali or alkaline earth metal-containing compounds (especially alkaline earth metal-containing compounds such as magnesium compounds and calcium compounds), zeolite, hydrotalcite and the like are preferable. The heat stabilizer may be used alone or in combination of two or more.

  Examples of the ultraviolet absorber include conventionally known benzophenone, benzotriazole, cyanoacrylate, salicylate, and oxalic anilide. For example, [2-hydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer, [2-hydroxy-4- (methacryloyloxymethoxy) benzophenone] -methyl methacrylate copolymer, [2-hydroxy -4- (methacryloyloxyoctoxy) benzophenone] -methyl methacrylate copolymer, [2-hydroxy-4- (methacryloyloxidedecyloxy) benzophenone] -methyl methacrylate copolymer, [2-hydroxy-4- ( Methacryloyloxybenzyloxy) benzophenone] -methyl methacrylate copolymer, [2,2′-dihydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer, [2,2′-dihydroxy-4- (Methacryloy Oxy) benzophenone] - methyl methacrylate copolymer, or [2,2'-dihydroxy-4- (methacryloyloxy-octoxybenzophenone) - methyl methacrylate copolymer, and the like. The ultraviolet absorbers may be used alone or in combination of two or more.

  Examples of the lubricant include petroleum-based lubricating oils such as liquid paraffin; synthetic lubricating oils such as halogenated hydrocarbons, diester oils, silicone oils, and fluorosilicones; various modified silicone oils (epoxy-modified, amino-modified, alkyl-modified, Ether-modified, etc .; Silicon-based lubricants such as copolymers of silicon and organic compounds such as polyoxyalkylene glycols; Silicon copolymers; Various fluorosurfactants such as fluoroalkyl compounds; Fluorine-based lubricating substances such as polymers; waxes such as paraffin wax and polyethylene wax; higher aliphatic alcohols, higher aliphatic amides, higher fatty acid esters, higher fatty acid salts, or molybdenum disulfide. Among these, it is particularly preferable to use a silicon copolymer (a resin obtained by polymerizing silicon by block or graft). Silicone copolymers include acrylic resins, polystyrene resins, polynitrile resins, polyamide resins, polyolefin resins, epoxy resins, polybutyral resins, melamine resins, vinyl chloride resins, polyurethane resins, or polyvinyl resins. What is necessary is just to block or graft-polymerize silicon to ether resin etc., It is preferable to use a silicon graft copolymer. These lubricating substances may be used alone or in combination of two or more.

  Examples of the waxes include olefin wax such as polypropylene wax and polyethylene wax, paraffin wax, Fischer-Tropsch wax, microcrystalline wax, montan wax, fatty acid amide wax, higher aliphatic alcohol wax, and higher fatty acid wax. , Fatty acid ester wax, carnauba wax, rice wax and the like. These waxes may be used alone or in combination of two or more.

  Examples of the colorant include inorganic pigments, organic pigments, and dyes. Examples of inorganic pigments include chromium pigments, cadmium pigments, iron pigments, cobalt pigments, ultramarine blue, and bitumen. Specific examples of organic pigments and dyes include, for example, carbon black; phthalocyanine pigments such as phthalocyanine copper; quinacridone pigments such as quinacridone magenta and quinacridone red; for example, Hansa Yellow, Disazo Yellow, Permanent Yellow, and Permanent. Examples include azo pigments such as red and naphthol red; for example, spirit black SB, nigrosine base, nigrosine dyes such as oil black BW, oil blue, pigment yellow, pigment blue, pigment red, and alkali blue. The colorants may be used alone or in combination of two or more.

  Examples of the crystallization accelerator include organic acid salts such as sodium pt-butylbenzoate, sodium montanate, calcium montanate, sodium palmitate, and calcium stearate; for example, calcium carbonate, calcium silicate, magnesium silicate, sulfuric acid Inorganic salts such as calcium, barium sulfate and talc; for example, metal oxides such as zinc oxide, magnesium oxide and titanium oxide. These crystallization accelerators may be used alone or in combination of two or more.

  You may perform a well-known process with respect to the resin composition concerning this invention. For example, in order to suppress hydrolysis of the biodegradable polymer compound in the resin composition according to the present invention, the resin composition according to the present invention may be irradiated with active energy rays.

  Examples of the active energy ray source include electromagnetic waves, electron beams, particle beams, and combinations thereof. Examples of the electromagnetic wave include ultraviolet rays (UV) and X-rays, and examples of the particle beam include rays of elementary particles such as protons and neutrons. Among these, electron beam irradiation by using an electron accelerator is particularly preferable.

  The active energy ray can be irradiated using a known apparatus. For example, a UV irradiation apparatus, an electron accelerator, etc. are mentioned. The irradiation dose and irradiation intensity are not particularly limited as long as the hydrolysis of the biodegradable polymer compound is effectively delayed in the resin composition according to the present invention. For example, in the case of an electron beam, the acceleration voltage is preferably about 100 to 5000 kV, and the irradiation dose is preferably about 1 kGy or more.

  The molded product obtained by molding the resin composition according to the present invention can be applied to various uses. Examples of the molding method of the molded product include pressure molding, film molding, extrusion molding, and injection molding. In particular, injection molding is preferable. More specifically, the extrusion molding can be performed according to a conventional method using a known extrusion molding machine such as a single-screw extruder, a multi-screw extruder, a tandem extruder, or the like. The injection molding can be performed according to a conventional method using a known injection molding machine such as an inline screw type injection molding machine, a multilayer injection molding machine, or a two-head injection molding machine. Moreover, it does not specifically limit as a method of shape | molding the resin composition of this invention, and manufacturing a molded article, All the well-known shaping | molding methods can be utilized.

A molded product formed by molding the resin composition of the present invention exhibits extremely high heat resistance by using an aliphatic polyester resin and a polysaccharide together as the resin composition, for example, a small audio product which is a kind of electrical product, etc. It is also possible to satisfy the requirement that the storage elastic modulus at 100 ° C. is 1 × 10 ⁸ Pa or more, which is the heat resistance required for.

  Moreover, since the molded product formed by molding the resin composition of the present invention contains a hydrolysis inhibitor that suppresses hydrolysis of these in a resin containing an aliphatic polyester and a polysaccharide, it exhibits biodegradability. The hydrolysis rate of the resin is delayed, and as a result, high mechanical strength, impact strength, etc. can be maintained over a long period of time.

  In addition, a molded product formed by molding the resin composition of the present invention is mainly composed of a biodegradable resin that is a safe component for a living body, and is easily decomposed in a natural environment. The negative impact on the environment after disposal can be reduced. For this reason, sufficient environmental consideration can be implement | achieved compared with the case where the existing synthetic resin is used by applying such a molded article to the housing | casing and packing material of an electric product.

  The molded product formed by molding the resin composition of the present invention is suitable for application to some of the following electrical products, for which it has been difficult to apply biodegradable resins. Specific electrical products include, for example, DVD (digital versatile disc) players, CD (compact disc) players, MD (mini disc) players, stationary AV equipment such as amplifiers, speakers, in-vehicle AV / IT equipment, electronic PDAs including books, video decks, projectors, TV receivers, monitors, digital video cameras, digital still cameras, printers, radios, radio cassettes, system stereos, microphones, headphones, keyboards, headphone stereos, portable CD players, portables Portable music machines such as MD players, so-called silicon audio players, refrigerators, washing machines, air conditioners, personal computers and computer peripherals, stationary game machines, portable game machines, mobile phones, telephones, fax machines , Copiers, entertainment robots and the like, the molded article of the present invention can be utilized as a housing for these electrical products. In addition, the molded product of the present invention can be used not only for a housing of an electric product, but also for other components such as parts and structural materials constituting the electric product. By using a molded product obtained by molding the resin composition of the present invention as a component of an electrical product, the electrical product exhibits sufficient heat resistance, mechanical strength, and biodegradability. Compared with resin, adverse effects on the natural environment at the time of disposal and after disposal can be reduced.

  In addition, the use of the molded product comprising the resin composition of the present invention is not limited to this, and since it exhibits biodegradability, it is a packaging material as well as disposable products mainly used for daily goods, sanitary goods, play goods, etc. It can be applied to all uses such as automobile use and industrial product use.

Examples of the present invention will be described in detail below, but it goes without saying that the present invention is not limited thereto. Among Examples 1 to 5 shown below, Examples 1 and 5 correspond to reference examples.

(Sample adjustment)
As biodegradable resin (A) Lacia H100J (manufactured by Mitsui Chemicals) belonging to polylactic acid, and (B) cellulose propionate 360A-09 (produced by Daicel Fachem) as esterified cellulose resin as a polysaccharide derivative resin ), (C) Esterified starch CPR-M3 (made by Nippon Corn Starch Co., Ltd.) which is a starch substituted derivative, (D) Esterified starch CPR-M2 (made by Nippon Corn Starch Co., Ltd.) which is a starch substituted derivative, (E) Hydrolysis inhibition Carbodilite HMV-8CA (Nisshinbo Co., Ltd.), which is an agent, and talc PKP-80 (Fuji talc, Inc.), which is an inorganic filler, were used as they were and mixed by a melt-kneading method.

As kneading conditions, a minimax-mix ruder (manufactured by Toyo Seiki Co., Ltd.) is used as a kneading machine, the nozzle temperature is set to 170 to 175 ° C., the torque is set to 4 to 6 kg, the residence time is within 3 seconds, and the resin (A ) To (D) were added with (E) and (F). After pelletizing the obtained resin composite, it was pressed at 170 ° C. at 300 Kg / cm ² , formed into a 1 mm-thick plate material, cut into a 7 mm × 50 mm size as a measurement test piece, and measured for elastic modulus. went.

The method for measuring the flexural modulus is shown below.
Measuring apparatus: (made by Rheometric) viscoelasticity analyzer test piece: length 50 mm × width 7 mm × thickness 1 mm
Frequency: 6.28 (rad / s)
Measurement start temperature: 25 ° C
Final measurement temperature: 160 ° C
Temperature increase rate: 5 (° C / min)
Strain: 0.05%

<Example 1>
(A) 100 parts by weight of polylactic acid lacia H100J, (B) 100 parts by weight of cellulose propionate 360A-09, (E) 3 parts by weight of hydrolysis inhibitor carbodilite HMV-8CA .

<Example 2>
(A) 25 parts by weight of (C) esterified starch CPR-M3, (E) 3 parts by weight of hydrolysis inhibitor carbodilite HMV-8CA, and (F) inorganic filler with respect to 100 parts by weight of polylactic acid lacia H100J This is a system in which 16 parts by weight of talc is added.

<Example 3>
(A) 40 parts by weight of (C) esterified starch CPR-M3, (E) 3 parts by weight of hydrolysis inhibitor carbodilite HMV-8CA, and (F) inorganic filler with respect to 100 parts by weight of polylactic acid lacia H100J This is a system to which 26 parts by weight of talc is added.

<Example 4>
(A) 100 parts by weight of polylactic acid lacia H100J, (C) 60 parts by weight of esterified starch CPR-M3, (E) 3 parts by weight of hydrolysis inhibitor Carbodilite HMV-8CA, (F) inorganic filler This is a system to which 40 parts by weight of talc is added.

<Example 5>
(A) 100 parts by weight of polylactic acid lacia H100J, (D) 95 parts by weight of esterified starch CPR-M3, (E) 3 parts by weight of hydrolysis inhibitor Carbodilite HMV-8CA, (F) inorganic filler This is a system in which 5 parts by weight of talc is added.

<Comparative Example 1>
(A) Polylactic acid lacia H100J simple substance system, which is a comparative example for Examples 1-5.

<Comparative example 2>
(B) Propion cellulose 360A-09 is a single system and is a comparative example with respect to Example 1.

<Comparative Example 3>
(C) It is a system of esterified starch CPR-M3 alone, and is a comparative example for Examples 2-4.

<Comparative example 4>
(D) Esterified starch CPR-M2 simple substance system, which is a comparative example with respect to Example 5.

Table 1 below shows a composition list (composition: parts by weight) of the samples prepared as described above. Moreover, as a result of comparing how much the temperature at which the storage elastic modulus is 1 × 10 ⁸ Pa or more is improved in Examples 1 to 5 compared to Comparative Examples 2 to 4 which is a resin simple substance system, It describes in (G) of Table 1.

  In addition, the measurement results of the storage elastic modulus of Example 1, Example 2 and Comparative Example 1 are shown in FIG. 1, and the results of the storage elastic modulus of Examples 2 to 3, Comparative Example 1 and Comparative Example 3 are shown in FIG. The results of the storage elastic modulus of Example 5, Comparative Example 1 and Comparative Example 4 are shown in FIG.

  From FIG. 1 and Table 1, the polylactic acid alone (Comparative Example 1) shows a sharp decrease in storage elastic modulus from around 60 ° C. On the other hand, in Example 1 in which esterified cellulose (Comparative Example 2) and hydrolysis inhibitor having high heat resistance were mixed with polylactic acid (Comparative Example 1), compared to Comparative Example 1 which is a simple substance of polylactic acid, It can be seen that the heat resistance is greatly improved.

  Moreover, from FIG. 2 and Table 1, with respect to the polylactic acid single-piece | unit (Comparative Example 1) whose storage elastic modulus falls rapidly around 60 degreeC, esterified starch (C) (Comparative Example 3) with high heat resistance and hydrolysis In Examples 2 to 4 in which the inhibitor is mixed, it can be seen that the heat resistance is significantly improved as compared with the polylactic acid alone (Comparative Example 1) and the esterified starch alone (C) (Comparative Example 3). However, since this esterified starch (C) has a low storage elastic modulus around room temperature as compared with esterified cellulose (B), talc (E), which is an inorganic filler, was added in Examples 2 to 4.

  Moreover, from FIG. 3 and Table 1, with respect to the polylactic acid single-piece | unit (Comparative Example 1) from which storage elastic modulus falls rapidly around 60 degreeC, esterified starch (D) (Comparative Example 4) with high heat resistance and hydrolysis In Example 5 in which the inhibitor was mixed, it can be seen that the heat resistance is greatly improved as compared with the polylactic acid alone (Comparative Example 1) and the esterified starch alone (D) (Comparative Example 4). However, since this esterified starch (D) has a lower storage elastic modulus near room temperature than the esterified cellulose (B), as in the esterified starch (C), in Example 5, talc (inorganic filler) E) was added.

It is a characteristic view which shows the storage elastic modulus of Example 1, the comparative example 1, and the comparative example 2. FIG. It is a characteristic view which shows the storage elastic modulus of Example 2-Example 4, the comparative example 1, and the comparative example 3. FIG. It is a characteristic view which shows the storage elastic modulus of Example 5, the comparative example 1, and the comparative example 4.

Claims (4)

Containing an aliphatic polyester resin exhibits at least one biodegradable, and esterified starch, and it suppresses hydrolysis inhibitor hydrolysis of the aliphatic polyester resin and / or esterified starches indicating the biodegradable ,
The aliphatic polyester resin is polylactic acid,
A resin composition containing 25 to 60 parts by weight of the esterified starch with respect to 100 parts by weight of the polylactic acid .   The resin composition according to claim 1, wherein the hydrolysis inhibitor is a carbodiimide compound, an isocyanate compound, or an oxazoline compound. Contains at least one biodegradable aliphatic polyester resin, esterified starch, and a hydrolysis inhibitor that suppresses hydrolysis of the biodegradable aliphatic polyester resin and / or esterified starch. Ri Na by molding the resin composition,
The aliphatic polyester resin is polylactic acid,
A molded article containing 25 to 60 parts by weight of the esterified starch with respect to 100 parts by weight of the polylactic acid . Aliphatic polyester resins having at least one biodegradable, and esterified starch, and suppresses hydrolysis inhibitor hydrolysis of the aliphatic polyester resin and / or esterified starches indicating the biodegradable composite ,
The aliphatic polyester resin is polylactic acid,
The manufacturing method of the resin composition which contains 25-60 weight part of said esterified starch with respect to 100 weight part of said polylactic acid .