JP5218685B2 - Resin composition and molded article comprising the same - Google Patents

Description

  The present invention relates to a resin composition and a molded product comprising the same, and more particularly to a resin composition containing a polylactic acid resin having excellent transparency, heat resistance and fluidity, and a molded product comprising the same.

  In recent years, biodegradable polymers that are decomposed in the natural environment by the action of microorganisms existing in soil or water have attracted attention from the viewpoint of global environmental conservation, and various biodegradable polymers have been developed. Of these, as a biodegradable polymer that can be melt-molded, for example, a fat comprising an aliphatic dicarboxylic acid component such as polyhydroxybutyrate, polycaprolactone, succinic acid or adipic acid, and a glycol component such as ethylene glycol or butanediol. Family polyesters and polylactic acid resins are well known. Among these, polylactic acid resin can be produced at low cost by fermentation using microorganisms, using lactic acid as a raw material for lactic acid as a raw material, and has transparency and a melting point of about 170. It is expected to be a biopolymer that can be melt molded at a high temperature.

  However, polylactic acid resin has a glass transition temperature of around 60 ° C., and its thermal deformation and rigidity decrease near this temperature are large. Therefore, when it is used as various molded products, it is easily deformed under normal usage conditions. Therefore, a polylactic acid material having excellent heat resistance has been desired.

  Furthermore, in the case of an injection molded product, it is important to have excellent fluidity in terms of molding processability in the injection molding process, and the polylactic acid material is excellent in all of transparency, heat resistance and fluidity. Was desired.

  Patent Document 1 describes that a resin composition having excellent heat resistance can be obtained with respect to a resin composition composed of polylactic acid and an acrylate polymer. However, it is completely disclosed that the transparency of polylactic acid is maintained. Even in the examples, although heat resistance is improved, there is no example of transparency and fluidity, and there is no suggestion of a solution for obtaining a resin composition excellent in all of transparency, heat resistance and fluidity. It has not been.

  Patent Document 2 describes that a resin composition excellent in hydrolyzability can be obtained with respect to a resin composition comprising an α-hydroxycarboxylic acid polymer containing polylactic acid and poly (meth) acrylate. 3 describes that a resin composition excellent in molding processability can be obtained with respect to a resin composition composed of polylactic acid and an acrylic compound, but none of them discloses heat resistance and fluidity. No solution is suggested for obtaining a resin composition having excellent transparency, heat resistance and fluidity.

  Patent Document 4 describes that a resin composition excellent in both transparency and heat resistance is obtained with respect to a resin composition comprising a polylactic acid polymer and an acrylic polymer. Describes that a biaxially stretched film made of a resin composition excellent in both transparency and heat resistance is obtained with respect to a resin composition made of polylactic acid and poly (meth) acrylate. Describes a resin composition composed of polylactic acid and polymethylmethacrylate, and it is described that a resin composition excellent in both transparency and heat resistance can be obtained. Although it is described that the glass transition temperature is improved by mixing polymethylmethacrylate, there is no disclosure about fluidity in any case. Re heat resistance improving effect is insufficient, and further improvement is required not at all suggest solving means for obtaining a transparency, heat resistance and any resin composition excellent in the fluidity.

US Pat. No. 5,300,536 (page 1-2) JP-A-8-59949 (page 1-2) JP 2002-155207 A (page 1-2) JP 2004-269720 A (page 1-2) International Patent Publication No. 2004/87812 (page 1-3) Japanese Patent Laying-Open No. 2005-171204 (page 1-2)

Polymer Preprints Japan, 42 (3), 1180 (1993) Polymer, 39 (26), 6891 (1998)

  This invention makes it a subject to provide the resin composition containing the polylactic acid-type resin excellent in transparency, heat resistance, and fluidity | liquidity, and a molded article consisting thereof.

  The present invention employs the following means in order to solve such problems.

That is, the present invention
(1) Resin formed by blending (A) polylactic acid resin and (B) methacrylic resin in a weight ratio ((A) polylactic acid resin / (B) methacrylic resin) of 90/10 to 10/90 (A) The polylactic acid-based resin (A) contains 95% or more of L-form or 95% or more of D-form, and has a weight average molecular weight of 10,000 or more and 500,000 or less, (B) At least one methacrylic resin has a weight average molecular weight of 50,000 to 450,000, syndiotacticity of 45 to 56%, a glass transition temperature of 110 ° C. or higher, a temperature of 230 ° C., and a load of 37.2 N. The resin composition is a methacrylic resin having a melt flow rate of 1 to 30 g / 10 min, and the ratio of syndiotacticity and isotacticity of the methacrylic resin in the resin composition (syndiotacticity) (Chi / isotacticity) is 3.0 to 8.5,
(2) The resin composition according to (1), wherein the glass transition temperature of the resin composition is 70 ° C. or higher,
(3) The resin composition according to any one of (1) to (2), wherein the blending ratio of (A) polylactic acid resin and (B) methacrylic resin is 59/41 to 10/90,
(4) The melt flow rate measured at 190 ° C. and 21.2 N load of the resin composition is 30 g / 10 min or less and 0.1 g / 10 min or more, in any one of (1) to (3) The resin composition according to the description,
(5) A molded article comprising the resin composition according to any one of (1) to (4),
(6) The molded product according to (5), wherein the molded product is any one of an injection molded product, an extrusion molded product, a blow molded product, and a film.
It is.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition containing the polylactic acid-type resin excellent in transparency, heat resistance, and fluidity | liquidity, and a molded article consisting thereof can be provided.

  The (A) polylactic acid-based resin used in the present invention is a polymer containing L-lactic acid and / or D-lactic acid as a main constituent component, but may contain other copolymerization components other than lactic acid. Examples of such other copolymer component units include polyvalent carboxylic acids, polyhydric alcohols, hydroxycarboxylic acids, lactones, and the like. Specifically, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid , Azelaic acid, sebacic acid, dodecanedioic acid, fumaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, anthracene dicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-tetrabutyl Polycarboxylic acids such as phosphonium sulfoisophthalic acid, ethylene glycol, propylene glycol, butanediol, heptanediol, hexanediol, octanediol, nonanediol, decanediol, 1,4-cyclohexanedimethanol, neopentylglyco Glycerin, pentaerythritol, bisphenol A, aromatic polyhydric alcohol obtained by addition reaction of bisphenol with ethylene oxide, polyhydric alcohols such as diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, glycolic acid, Hydroxycarboxylic acids such as 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, hydroxybenzoic acid, and glycolide, ε-caprolactone glycolide, ε-caprolactone, β-propiolactone, δ Lactones such as -butyrolactone, β- or γ-butyrolactone, pivalolactone, and δ-valerolactone can be used.

In the present invention, it is preferable to use polylactic acid having a high optical purity of the lactic acid component from the viewpoint of heat resistance. That is, (A) Of the total lactic acid component of the polylactic acid-based resin, 95% or more of the L isomer or 95% or more of the D isomer , and 98% or more of the L isomer or the D isomer There it is good preferable to contain 98% or more. Moreover, the upper limit of the content of L-form or D-form is usually 100% or less.

The molecular weight and molecular weight distribution of (A) polylactic acid resin, substantially molding is possible, but are not particularly limited, a weight average molecular weight, in terms of heat resistance, more than 10,000 by weight, more preferably more than 40,000, more preferably 80,000 or more, particularly preferably 100,000 or more, and most preferably from the at 130,000 or more. The upper limit is not particularly limited, in terms of fluidity, she is a 5 0 10,000 or less, more preferably 300,000 or less, more preferably 250,000 or less, further preferably 200,000 or less. The weight average molecular weight here is a weight average molecular weight in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent.

  (A) Although it does not specifically limit about melting | fusing point of polylactic acid-type resin, It is preferable that it is 120 degreeC or more, and it is more preferable that it is 150 degreeC or more. The melting point here is the temperature at the peak top of the endothermic peak measured by a differential scanning calorimeter (DSC).

  (A) As a manufacturing method of polylactic acid-type resin, a well-known polymerization method can be used, the direct polymerization method from lactic acid, the ring-opening polymerization method via a lactide, etc. can be used.

  In the present invention, the (B) methacrylic resin may contain a methyl methacrylate component unit as a main component, preferably 70% or more, and preferably contains other vinyl monomer component units of 30% or less, More preferably, it may be a copolymer copolymerized by 20% or less. Other vinyl monomers include aromatic vinyl monomers such as α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, and pt-butylstyrene. , Vinyl cyanide monomers such as acrylonitrile, methacrylonitrile, ethacrylonitrile, glycidyl itaconate, allyl glycidyl ether, styrene-p-glycidyl ether, p-glycidyl styrene, maleic anhydride, monoethyl maleate N-substituted maleimides such as itaconic acid, itaconic anhydride, glutaric anhydride, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, acrylamide, methacrylamide, N-methylacrylamide, Butoxymethyl Kurylamide, N-propylmethacrylamide, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, aminoethyl acrylate, propylaminoethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxy acrylate Propyl, glycidyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, butanediol diacrylate, nonanediol diacrylate, polyethylene glycol diacrylate, methyl 2- (hydroxymethyl) acrylate, 2- (hydroxy Methyl) ethyl acrylate, methacrylic acid, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, dimethylaminoethyl methacrylate, ethylamino methacrylate Nopropyl, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentanyl methacrylate, pentamethacrylate Methylpiperidyl, tetramethylpiperidyl methacrylate, benzyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, polyethylene glycol dimethacrylate, N-vinyldiethylamine, N-acetylvinylamine, allylamine, methallylamine, N-methyl Allylamine, p-aminostyrene, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxy Gelsolin and 2-styryl - and oxazoline. These vinyl monomers may be used alone or in combination. From the viewpoints of heat resistance, low hygroscopicity, and surface hardness, a copolymer containing a ring structural unit such as a lactone ring, maleic anhydride, glutaric anhydride, etc. in the main chain is preferred. Furthermore, when a copolymer containing a ring structure in the main chain is used, it is more preferable to use a methacrylic resin not containing a ring structure.

As the (B) methacrylic resin used in the present invention, at least one of the (B) methacrylic resin is a methacrylic resin having a weight average molecular weight of 50,000 to 450,000 and a syndiotacticity of 45 % or more. By using a methacrylic resin that satisfies such conditions, the intermolecular interaction with the polylactic acid resin is increased and the affinity is improved, so that a resin composition excellent in transparency and heat resistance can be obtained.

  As the (B) methacrylic resin used in the present invention, it is preferable that at least one of the (B) methacrylic resin has a weight average molecular weight of 70,000 to 200,000 in terms of heat resistance and fluidity. 10,000 to 150,000 are more preferable. The weight average molecular weight here is a weight average molecular weight in terms of polymethyl methacrylate (PMMA) measured by GPC using hexafluoroisopropanol as a solvent.

As the (B) methacrylic resin used in the present invention, at least one of the (B) methacrylic resin is syndiotactic 45% or more , more preferably 50% or more, from the viewpoint of heat resistance. % Or more is more preferable, 70% or more is particularly preferable, and in terms of fluidity, 90% or less is preferable, and 80% or less is more preferable. Further, the heterotacticity of the (B) methacrylic resin is preferably 45% or less, more preferably 40% or less in terms of heat resistance, and 20% or more in terms of fluidity. It is preferable that it is 30% or more. The isotacticity of the (B) methacrylic resin is preferably 20% or less, more preferably 15% or less in terms of heat resistance, and 5% or more in terms of fluidity. It is preferably 8% or more, more preferably 10% or more. As used herein, syndiotacticity, heterotacticity, and isotacticity are those directly observed at 0.9 ppm, 1.0 ppm, and 1.2 ppm in 1H-NMR measurement using deuterated chloroform as a solvent. The total integrated intensity of the peaks of chain-branched methyl groups is 100%, and the ratio of the integrated intensity of each peak is expressed as a percentage.

The (B) methacrylic resins used in the present invention, in view of heat resistance, (B) at least one methacrylic resin has a glass transition temperature of 110 ° C. or higher, particularly preferably at least 115 ° C., 120 Most preferred is ℃ or higher. Although an upper limit is not specifically limited, 150 degreeC or less is preferable at the point of fluidity | liquidity. The glass transition temperature here is a value measured according to the method described in JIS K7121, and is the midpoint glass transition temperature when the temperature is raised at 20 ° C./min by DSC measurement. In the present invention, (B) the methacrylic resin preferably contains at least one methacrylic resin having a glass transition temperature of 110 ° C. or higher.

As the (B) methacrylic resin used in the present invention, in terms of fluidity, at least one of the (B) methacrylic resin is a melt flow rate (MFR) at a temperature of 230 ° C. and a load of 37.2 N. Is 1 to 30 g / 10 min , and more preferably 2 to 20 g / 10 min. If the MFR is less than 1 g / 10 minutes, the fluidity tends to decrease and the moldability tends to be inferior. If it exceeds 30 g / 10 minutes, the heat resistance improving effect tends to decrease, such being undesirable.

In the present invention, (A) blending ratio of polylactic acid resin and (B) methacrylic resins, in terms of heat resistance and flowability, the weight ratio ((A) polylactic acid resin / (B) methacrylic resins) it There 9 0 / 10-10 / 90, more preferably 80 / 20-20 / 80, particularly preferably from 70 / 30-30 / 70, a 59 / 41-35 / 65 Is most preferred.

  By using a methacrylic resin that satisfies these conditions, the intermolecular interaction with the polylactic acid resin is increased and the affinity is improved, so the effect of improving heat resistance is increased, and transparency, heat resistance and fluidity are increased. An excellent resin composition can be obtained.

  In the present invention, in terms of heat resistance and fluidity, the difference in glass transition temperature is preferably 15 ° C. or higher, and more preferably 20 ° C. or higher. If the difference in glass transition temperature is less than 10 ° C., the effect of improving heat resistance is insufficient. Moreover, although the upper limit of the difference of glass transition temperature is not specifically limited, It is preferable that it is 60 degrees C or less at the point of transparency. The glass transition temperature here is a value measured according to the method described in JIS K7121, and is the midpoint glass transition temperature when the temperature is raised at 20 ° C./min by DSC measurement.

  In the present invention, when two or more kinds of methacrylic resins are used, the glass transition temperature region, that is, the specific heat capacity change region tends to be wider than when used alone, and preferably the glass transition temperature ± 10. ° C, more preferably glass transition temperature ± 20 ° C, still more preferably glass transition temperature ± 30 ° C, particularly preferably glass transition temperature ± 40 ° C.

  In the present invention, in terms of heat resistance and fluidity, the difference in syndiotacticity is preferably 5% or more, more preferably 7% or more, and further preferably 10% or more. If the difference in syndiotacticity is less than 3%, the heat resistance improving effect is insufficient. Moreover, the upper limit of the difference of syndiotacticity is not particularly limited, but is preferably 50% or less from the viewpoint of transparency. Syndiotacticity as used herein refers to 0.9 ppm and 1.0 ppm observed as syndiotacticity, heterotacticity and isotacticity, respectively, in 1H-NMR measurement using deuterated chloroform as a solvent. The total integral intensity of 1.2 ppm linear branched methyl group peaks is taken as 100%, and the ratio of the integral intensity of each peak can be calculated as a percentage.

  As the methacrylic resin (B) used in the present invention, the composition of two or more methacrylic resins is not particularly limited, but the glass transition temperature or syndiotacticity is the highest in terms of heat resistance and fluidity. The weight ratio of methacrylic resin 1 to methacrylic resin 2 is defined as methacrylic resin 1 having the lowest glass transition temperature or syndiotacticity as methacrylic resin 2. The methacrylic resin 1 / methacrylic resin 2) is preferably 10/90 to 90/10, more preferably 60/40 to 40/60.

  As a manufacturing method of (B) methacrylic resin used by this invention, well-known polymerization methods, such as block polymerization, solution polymerization, suspension polymerization, and emulsion polymerization, can be used. The temperature condition during the polymerization is not particularly limited, but is preferably 100 ° C. or lower, more preferably 70 ° C. or lower, further preferably 30 ° C. or lower, and particularly preferably −10 ° C. or lower in terms of heat resistance of the methacrylic resin.

  In the resin composition of the present invention, fillers (glass fiber, carbon fiber, metal fiber, natural fiber, organic fiber, glass flake, glass bead, ceramic fiber, ceramic bead, asbestos are used as long as the object of the present invention is not impaired. , Wollastonite, talc, clay, mica, sericite, zeolite, bentonite, dolomite, kaolin, finely divided silicic acid, feldspar powder, potassium titanate, shirasu balloon, calcium carbonate, magnesium carbonate, barium sulfate, calcium oxide, aluminum oxide, Titanium oxide, aluminum silicate, silicon oxide, gypsum, novaculite, dawsonite, clay, etc.), stabilizers (antioxidants, UV absorbers, etc.), lubricants, mold release agents, flame retardants, colorants including dyes and pigments, crystals Add nucleating agent, plasticizer, antistatic agent, etc. Door can be. Especially, it is preferable to mix | blend a mold release agent at the point that the resin composition excellent in mechanical characteristics, a moldability, heat resistance, transparency, etc. is obtained. As the mold release agent, those usually used for mold release agents for thermoplastic resins can be used. Specifically, fatty acids, fatty acid metal salts, oxy fatty acids, fatty acid esters, partially aliphatic saponified esters, paraffin, low molecular weight polyolefins, fatty acid amides, alkylene bis fatty acid amides, aliphatic ketones, fatty acid lower alcohol esters, fatty acid polyhydric alcohols Examples thereof include esters, fatty acid polyglycol esters, and modified silicones. The compounding amount of the release agent is preferably 0.01 to 3 parts by weight, more preferably 0.03 to 2 parts by weight with respect to 100 parts by weight as a total of (A) polylactic acid resin and (B) methacrylic resin. preferable.

  Further, with respect to the resin composition used in the present invention, other thermoplastic resins (for example, polyethylene resin, polypropylene resin, polymethylpentene resin, cyclic olefin resin, acrylonitrile. Butanediene / styrene (ABS) resin, acrylonitrile / styrene (AS) resin, cellulose resin such as cellulose acetate, polyamide resin, polyacetal resin, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyphenylene oxide resin, Polyarylate resins, polysulfone resins, polyphenylene sulfide resins, polyether ether ketone resins, polyimide resins, polyether imide resins, etc.) and thermosetting resins (eg If phenolic resins, melamine resins, polyester resins, silicone resins, and epoxy resins) may be further added at least one or more kinds of such.

  Although the manufacturing method of the resin composition of this invention is not specifically limited, For example, after previously blending (A) polylactic acid-type resin, (B) methacrylic-type resin, and other additives as needed A method of uniformly melting and kneading with a single or twin screw extruder above the melting point, a method of removing the solvent after mixing in a solution, etc. are used, but in terms of productivity, uniformly with a single screw or twin screw extruder A method of melt kneading is preferred, and a method of uniformly melt kneading with a twin screw extruder is more preferred in that a resin composition excellent in transparency, heat resistance and fluidity can be obtained.

The resin composition of the present invention, the ratio of the methacrylic resin in the resin composition syndiotacticity and isotacticity (syndiotacticity / isotacticity) are from 3.0 to 8.5. Further, from the viewpoint of heat resistance and fluidity, it is more preferably 3.0 to 8.0, further preferably 3.0 to 5.5, and 3.0 to 5.0. Particularly preferred. In the present invention, particularly when the ratio of syndiotacticity to isotacticity is less than 3.0 or more than 8.0, the effect of improving heat resistance and fluidity is small, and syndiotacticity and isotacticity. Surprisingly, it has been found that the effect of improving the heat resistance and fluidity is remarkably enhanced by the ratio of Schichi being 3.0 to 8.0. As a method for obtaining a resin composition capable of achieving a tacticity ratio, the requirements described in the present invention such as weight average molecular weight, stereoregularity (syndiotacticity, heterotacticity, isotacticity) and glass transition temperature are satisfied. Use of a methacrylic resin, preferably two or more kinds of metaxites having a glass transition temperature difference and a syndiotacticity difference within a specific range. It is considered important to use a Le-based resin. Syndiotacticity, heterotacticity, and isotacticity mentioned here are observed as syndiotacticity, heterotacticity, and isotacticity, respectively, in 1H-NMR measurement using deuterated chloroform as a solvent. This is a value that can be calculated by expressing the percentage of the integrated intensity of each peak as a percentage, with the total integrated intensity of the peaks of the straight chain branched methyl groups of 0.9 ppm, 1.0 ppm, and 1.2 ppm being 100%. .

  About the resin composition of this invention, it is preferable that a glass transition temperature is 70 degreeC or more at a heat resistant point, It is more preferable that it is 75 degreeC or more, It is further more preferable that it is 80 degreeC or more, 90 degreeC The above is particularly preferable. Although an upper limit is not specifically limited, From a fluidity | liquidity point, it is preferable that it is 150 degrees C or less, and it is more preferable that it is 120 degrees C or less. The glass transition temperature here is a value measured by DSC according to the method described in JIS K7121, and may be either the midpoint glass transition temperature or the extrapolation transition end temperature. In DSC measurement, the DSC curve is bent due to the change in specific heat capacity, and the glass transition temperature region can be detected by the shape in which the base line moves in parallel. The midpoint glass transition temperature refers to the tangent lines of the respective base lines below the bending point and above the bending point so as to be parallel to each other, and at each position where the specific heat capacity change is halved. This is the intersection of a DSC curve that draws a straight line parallel to the baseline and bends. The extrapolation transition end temperature refers to the intersection of the tangent line of the base line of the temperature above the bending point and the tangent line of the point having the maximum inclination at the bent part.

  The resin composition of the present invention is preferably transparent. Here, the term “transparent” means that there is a portion where the character can be read when the molded product is superimposed on a printed matter such as a newspaper. Specifically, the haze when formed into a molded product having a thickness of 20 μm or more, preferably 1 mm is preferably 30% or less, more preferably 10% or less in terms of excellent transparency. More preferably, the haze is 5% or less. In the present invention, haze is a value measured according to JIS K7105. Further, the transparency can be determined by the total light transmittance measured according to JIS K6714, and the total light transmittance is preferably 80% or more, more preferably 85% or more. Preferably, it is 90% or more.

  With respect to the resin composition of the present invention, the melt flow rate (MFR) is not particularly limited, but in terms of heat resistance, the MFR measured at 190 ° C. and 21.2 N load is 30 g / 10 min in accordance with JIS K7210. Or less, more preferably 20 g / 10 min or less, and even more preferably 15 g / 10 min or less. When MFR exceeds 30 g / 10 min, the heat resistance tends to decrease. In terms of fluidity, it is preferably 0.1 g / 10 minutes or more, more preferably 1 g / 10 minutes or more, and further preferably 3 g / 10 minutes or more. When the MFR is less than 0.1 g / 10 min, the fluidity is lowered and the processability at the time of injection molding tends to be lowered.

  The surface hardness of the resin composition of the present invention is not particularly limited, but the pencil hardness measured according to JIS K-5600 is preferably HB or more, more preferably F or more, and H or more. More preferably. When the pencil hardness is lower than HB, the surface is easily scratched, which is not preferable. When the resin composition of the present invention is used as an optical recording medium, it is preferably HB or more, and is preferably HB or more, in that it is less likely to be scratched when processed into a substrate and reading errors are less likely to occur. Further, it is preferably 3H or less, more preferably 2H or less, from the viewpoint that the optical recording medium is less likely to be destroyed by an impact such as dropping.

  With respect to the resin composition of the present invention, the saturated water absorption is not particularly limited, but the saturated water absorption measured according to ASTM D570 is preferably 0.4% by weight or less, and 0.3% by weight or less. Is more preferably 0.2% by weight or less, and particularly preferably 0.1% by weight or less. The lower limit is not particularly limited. If the saturated water absorption exceeds 0.4% by weight, deformation due to moisture absorption is likely to occur and the possibility of being unusable increases.

  Although the retardation (birefringence amount) of the resin composition of the present invention is not particularly limited, it was measured by irradiating a laser beam of 23 ° C. and 405 nm at an angle of 30 ° C. with respect to the substrate surface using a commercially available ellipsometer. The retardation is preferably 50 nm or less, more preferably 30 nm or less, further preferably 20 nm or less, particularly preferably 10 nm or less, and most preferably 5 nm or less. When the resin composition of the present invention is used as an optical recording medium, if the retardation exceeds 50 nm, reading errors and the like are liable to occur, such being undesirable.

  The resin composition of the present invention can be processed into various molded products and used by a method such as injection molding or extrusion molding.

  Examples of the molded product made of the resin composition of the present invention include injection molded products, extrusion molded products, blow molded products, films and sheets. In the present invention, a molded product having a portion having a thickness of 20 μm or more is preferable and a molded product having a portion having a thickness of 1 mm or more is more preferable in terms of excellent heat resistance. Furthermore, in terms of excellent heat resistance and impact resistance, the molded product preferably has a portion having a thickness of 50 mm or less, more preferably a molded product having a portion of 10 mm or less, and a portion of 5 mm or less. More preferably, it is a molded product.

  The molded product made of the resin composition of the present invention preferably has a portion having a thickness of 20 μm or more, preferably 1 mm and a haze of 30% or less, in terms of excellent transparency. It is more preferable to have a portion that is 10% or less, and even more preferable to have a portion that is 5% or less. In the present invention, haze is a value measured using a haze meter in accordance with JIS K7105.

  The molded article made of the resin composition of the present invention can be used for various applications such as electric / electronic parts, building members, automobile parts, various containers, daily necessities, household goods and sanitary goods.

  Specifically, mobile terminals such as relay cases, coil bobbins, optical pickup chassis, motor cases, notebook computer housings and internal parts, CRT display housings and internal parts, printer housings and internal parts, mobile phones, mobile personal computers, handheld mobiles Housing and internal components, recording media (CD, DVD, PD, FDD, etc.) drive housing and internal components, copier housing and internal components, facsimile housing and internal components, parabolic antennas and other electrical / electronic components Can be mentioned. Furthermore, VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustic parts, video camera parts, video equipment parts such as projectors, laser discs (registered trademark), compact discs (CD), CD-ROMs , CD-R, CD-RW, DVD-ROM, DVD-R, DVD-RW, DVD-RAM, Blu-ray disc and other optical recording media substrates, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts , Etc., home and office electrical appliance parts. Also, housings and internal parts of electronic musical instruments, home game machines, portable game machines, various gears, various cases, sensors, LEP lamps, connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, Optical pickups, oscillators, various terminal boards, transformers, plugs, printed wiring boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, power modules, semiconductors, liquid crystals, FDD carriages, FDD chassis, motor brush holders , Electrical and electronic parts such as transformer members, coil bobbins, sash doors, blind curtain parts, piping joints, curtain liners, blind parts, gas meter parts, water meter parts, water heater parts, roof panels, Hot walls, adjusters, plastic bundles, ceiling fishing gear, staircases, doors, floors and other building materials, fishing lines, fishing nets, seaweed aquaculture nets, fishing bait bags and other marine products, vegetation nets, vegetation mats, weedproof bags, protection Grass net, curing sheet, slope protection sheet, fly ash holding sheet, drain sheet, water retention sheet, sludge / sludge dewatering bag, concrete formwork and other civil engineering related parts, air flow meter, air pump, thermostat housing, engine mount, ignition hobbin , Ignition case, clutch bobbin, sensor housing, idle speed control valve, vacuum switching valve, ECU housing, vacuum pump case, inhibitor switch, rotation sensor, acceleration sensor, distributor cap, coil base, AB Actuator case, radiator tank top and bottom, cooling fan, fan shroud, engine cover, cylinder head cover, oil cap, oil pan, oil filter, fuel cap, fuel strainer, distributor cap, vapor canister housing, air cleaner housing, Timing belt covers, brake booster parts, various cases, various tubes, various tanks, various hoses, various clips, various valves, various pipes and other automotive underhood parts, torque control levers, safety belt parts, register blades, washer levers, Window regulator handle, knob of window regulator handle, passing light lever, samba Automotive interior parts such as Iser brackets, various motor housings, roof rails, fenders, garnishes, bumpers, door mirror stays, spoilers, hood louvers, wheel covers, wheel caps, grill apron cover frames, lamp reflectors, lamp bezels, door handles, etc. Automotive exterior parts, wire harness connectors, SMJ connectors, PCB connectors, door grommet connectors and other automotive connectors, gears, screws, springs, bearings, levers, key stems, cams, ratchets, rollers, water supply parts, toy parts, fans, Tegs, pipes, cleaning jigs, motor parts, microscopes, binoculars, cameras, watches and other mechanical parts, multi-films, tunnel films, bird protection sheets, vegetation protection nonwoven fabrics, seedlings Pot, vegetation pile, seed string tape, germination sheet, house lining sheet, farm-bi fastener, slow-release fertilizer, root-proof sheet, garden net, insect net, young tree net, printed laminate, fertilizer bag, sample Agricultural materials such as bags, sandbags, beast harm prevention nets, inducement strings, windproof nets, disposable diapers, sanitary wrapping materials, cotton swabs, towels, toilet seat wipes, etc., medical non-woven fabrics (stitching reinforcements, adhesion prevention films, Prosthetic repair materials), wound dressing materials, wound tape bandages, sticky material base fabric, surgical sutures, fracture reinforcements, medical films and other medical supplies, calendars, stationery, clothing, food packaging films, trays , Blisters, knives, forks, spoons, tubes, plastic cans, pouches, containers, tanks, baskets and other containers, tableware, hot-fill containers, microwave cooking containers cosmetics , Wrap, foam buffer, paper lami, shampoo bottle, beverage bottle, cup, candy packaging, shrink label, lid material, envelope with window, fruit basket, hand tape, easy peel packaging, egg pack, HDD packaging, Compost bags, recording media packaging, shopping bags, containers and packaging such as wrapping films for electrical and electronic parts, natural fiber composites, polo shirts, T-shirts, inners, uniforms, sweaters, socks, ties, and other clothing, curtains, chairs Paste, carpet, table cloth, cloth mat, wallpaper, furoshiki interior goods, carrier tape, print lamination, heat sensitive stencil film, release film, porous film, container bag, credit card, cash card, ID card , IC card, paper, leather, non-woven fabric, etc. Hot melt binder, magnetic material, zinc sulfide, electrode material powder binder, optical element, conductive embossed tape, IC tray, golf tee, garbage bag, plastic bag, various nets, toothbrush, stationery, draining net, body towel , Hand towel, tea pack, drainage filter, clear file, coating agent, adhesive, bag, chair, table, cooler box, kumade, hose reel, planter, hose nozzle, dining table, desk surface, furniture panel, kitchen cabinet It is useful as a pen cap, gas lighter, etc.

  In particular, the resin composition of the present invention includes CD, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-R, DVD-RW, DVD-RAM, laser disc (registered trademark), Blu-ray disc, and the like. It is useful as a substrate for optical recording media.

  In the present invention, the production method of the substrate of the optical recording medium is not particularly limited, and a known method can be used, and examples thereof include an injection molding method, an extrusion molding method, an injection press molding method, and the like. An injection molding method is preferable in that a product having a high stability can be produced in large quantities. Various layers such as a reflective layer, a recording layer, an adhesive layer, a dielectric layer, and a protective layer formed on the substrate can be formed using a known method. In addition, as an adhesive agent used for an adhesive layer, it is preferable to use high heat-resistant adhesive agents, such as a polyimide type, from a heat resistant point. In addition, by changing the type of layers formed on the substrate, the number of stacked layers, and the like, a reproduction-only type, a write-once type, a rewritable type, and the like can be manufactured.

  In the present invention, the strength of the optical recording medium refers to the breaking strength of the optical recording medium, that is, the resistance to cracking. In the present invention, with one end of the optical recording medium fixed with a vise, etc., it can be determined by the angle until it breaks when the other end is held by hand. I can say that. Preferably, the strength is further improved if it is 20 degrees or more, more preferably 30 degrees or more.

  The resin composition of the present invention and a molded product comprising the resin composition can be recycled. For example, the resin composition and a molded product comprising the resin composition are heat-treated at 80 ° C. or higher, preferably 100 ° C. or higher, pulverized, preferably powdered, and then used with a solvent such as acetone or tetrahydrofuran, and (B) methacryl The system resin is isolated, and then the (A) polylactic acid resin can be isolated from the residue using a solvent such as chloroform. The isolated resins can be used alone, and the resin composition obtained by further blending them can be used in the same manner as the resin composition of the present invention, and can also be formed into a molded product.

  Hereinafter, the configuration and effects of the present invention will be described in more detail by way of examples. Here, the compounding ratio in an Example shows a weight part. Moreover, the raw material used and the code | symbol in a table | surface are shown below.

(A) Polylactic acid resin (A-1) Poly L lactic acid resin (D-form 1.2%, weight average molecular weight 120,000)
(A-2) Poly L-lactic acid resin (D-form 1.2%, weight average molecular weight 150,000)
(A-3) Poly-L lactic acid resin (D-form 1.2%, weight average molecular weight 210,000)

(B) Methacrylic resin (B-1) Methacrylic resin (“SUMIPEX LG21” manufactured by Sumitomo Chemical Co., Ltd.) Weight average molecular weight 80,000, glass transition temperature 105 ° C., syndiotacticity 41%, MFR 21 g / 10 min (230 ° C., 37. 2N))
(B-2) Methacrylic resin (Kuraray “Parapet” HR-L, weight average molecular weight 90,000, glass transition temperature 117 ° C., syndiotacticity 56%, MFR 2 g / 10 min (230 ° C., 37.2 N))
(B-3) Methacrylic resin (“SUMIPEX” LG35 manufactured by Sumitomo Chemical Co., Ltd., weight average molecular weight 100,000, glass transition temperature 90 ° C., syndiotactic 39%, MFR 35 g / 10 min (230 ° C., 37.2 N))

  The measurement method and determination method used in the present invention are shown below.

(1) Weight average molecular weight (Mw)
It is a value of weight average molecular weight in terms of standard PMMA measured by gel permeation chromatography (GPC). Hexafluoroisopropanol was used as a solvent, the flow rate was 0.5 mL / min, and 0.1 mL of a solution having a sample concentration of 1 mg / mL was injected and measured.

(2) Syndiotacticity and isotacticity These are values measured by 1H-NMR measurement. 1H-NMR measurement was performed using JNM-AL400 manufactured by JEOL Ltd., using deuterated chloroform as a solvent, and a sample concentration of 20 mg / mL. Each peak is defined as the total integrated intensity of the straight-chain branched methyl groups of 0.9 ppm, 1.0 ppm, and 1.2 ppm observed as syndiotacticity, heterotacticity, and isotacticity, respectively. The values representing the percentage of the integrated intensity of each as a percentage were defined as syndiotacticity, heterotacticity, and isotacticity, respectively.

(3) Glass transition temperature (Tg)
According to JIS K7121, it measured with the differential scanning calorimeter (Seiko Denshi RDC220). The measurement conditions are a sample 10 mg, a nitrogen atmosphere, and a temperature increase rate of 20 ° C./min.

(4) Transparency Using a Nippon Denshoku Industries haze meter NDH-300A, the haze of a 5 cm × 5 cm × 1 mm plate-shaped molded article was measured according to JIS-K7105.

(5) Fluidity (MFR)
About the fluidity | liquidity of the resin composition, it measured in 190 degreeC and a 21.2N load according to JISK7210.

(6) Tensile strength A tensile test was carried out using ASTM No. 1 dumbbell molded product according to ASTM method D638.

(7) Pencil hardness According to JIS K5600-5-4, the pencil hardness of the plate-shaped molded product of 5 cm x 5 cm x 1 mm was measured.

[Examples 1-4, Comparative Examples 1-4]
As shown in Table 1, a polylactic acid-based resin and a methacrylic resin are blended, and using a 30 mm diameter twin screw extruder, melt-kneading is performed under the conditions of a cylinder temperature of 200 ° C. and a rotation speed of 200 rpm to obtain a pellet-shaped resin composition. Obtained.

  The obtained resin composition was injection molded at a cylinder temperature of 200 ° C. and a mold temperature of 40 ° C. using an injection molding machine SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd., and a molded product with a notch of 3 mm thickness, 12.7 mm × 127 mm × 3 mm The molded product was a 3 mm thick ASTM No. 1 dumbbell molded product and a 5 cm × 5 cm × 1 mm plate-shaped molded product.

  Table 1 shows the results of various evaluations using the obtained molded product.

  From the results in Table 1, the following is clear.

  From comparison between Examples 1-4 and Comparative Examples 1 and 2-4, a polylactic acid resin and a methacrylic resin having a weight average molecular weight of 50,000 to 450,000 and a syndiotacticity of 40% or more were blended. It can be seen that the resulting resin composition is excellent in heat resistance, transparency, fluidity, strength, and pencil hardness.

[Examples 5-8, Comparative Examples 5-7]
As shown in Table 2, a polylactic acid resin and a methacrylic resin are blended, and a 30 mm diameter twin screw extruder is used for melt kneading under the conditions of a cylinder temperature of 200 ° C. and a rotation speed of 200 rpm to obtain a pellet-shaped resin composition. Obtained.

  The obtained resin composition was injection molded at a cylinder temperature of 200 ° C. and a mold temperature of 40 ° C. using an injection molding machine SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd., and a molded product with a notch of 3 mm thickness, 12.7 mm × 127 mm × 3 mm The molded product was a 3 mm thick ASTM No. 1 dumbbell molded product and a 5 cm × 5 cm × 1 mm plate-shaped molded product.

  Table 2 shows the results of various evaluations using the obtained molded product.

  From the results in Table 2, the following is clear.

  From the comparison between Examples 5 to 8 and Comparative Examples 5 and 6 to 7, as a polylactic acid resin and a methacrylic resin, the difference in glass transition temperature is 10 ° C. or more, or the difference in syndiotacticity is 3%. It can be seen that a resin composition comprising two or more methacrylic resins satisfying at least one of the above is excellent in heat resistance, transparency, fluidity, strength, and pencil hardness.

[Examples 9 to 10]
About Examples 9-10, except mix | blending polylactic acid-type resin and methacrylic-type resin as shown in Table 3, all make a resin composition and a molded article like Example 1, glass transition temperature, Haze and MFR were determined.

  Subsequently, a disk substrate on which uneven pits were formed was formed by injection molding using the obtained resin composition. A reflective film of aluminum is sputter-deposited on the obtained disk substrate, and then a UV curable resin (SD-1700, manufactured by Dainippon Ink Industries, Ltd.) is spin-coated thereon to form a protective layer. A compact disc as a recording medium was created.

The strength of the produced optical recording medium was determined according to the following criteria by measuring the angle until the half circle part was fixed with a vise and then the top of the other half circle part was bent by hand and bent.
A: 30 degrees or more B: 20-30 degrees Δ: 15-20 degrees x: 15 degrees or less.

Regarding the reproduction characteristics of the produced optical recording medium, after processing at 70 ° C. for 200 hours using a hot air dryer, or at a temperature of 50 ° C. and a relative humidity of 95% (95% RH) using a constant temperature and humidity chamber. After processing for 200 hours, whether or not the player can reproduce sound was determined according to the following criteria. In addition, the reproduction characteristics were also confirmed for untreated products.
A: Can be played back without problems.
○: Although it is slightly deformed, it can be reproduced.
Δ: There are some reading errors and reproduction is insufficient.
×: Cannot be reproduced at all.

  The results are shown in Table 3.

  From the results in Table 3, the following is clear.

  From Examples 9 to 10, as a polylactic acid resin and a methacrylic resin, two or more methacrylic resins satisfying at least one of a glass transition temperature difference of 10 ° C. or more or a syndiotacticity difference of 3% or more It can be seen that a resin composition containing a resin is excellent in heat resistance, transparency, and fluidity, and an optical recording medium using the resin composition as a substrate can be used without any problem.

Claims (6)

A resin composition comprising (A) a polylactic acid resin and (B) a methacrylic resin in a weight ratio ((A) polylactic acid resin / (B) methacrylic resin) of 90/10 to 10/90. And (A) the polylactic acid-based resin contains 95% or more of L-form or 95% or more of D-form, and has a weight average molecular weight of 10,000 or more and 500,000 or less, (B) At least one methacrylic resin has a weight average molecular weight of 50,000 to 450,000, a syndiotacticity of 45 to 56%, a glass transition temperature of 110 ° C. or higher, a temperature of 230 ° C. and a load of 37.2 N. A resin composition having a flow rate of 1 to 30 g / 10 min of a methacrylic resin, the ratio of syndiotacticity and isotacticity of the methacrylic resin in the resin composition (syndiotacticity / A resin composition having an isotacticity of 3.0 to 8.5. The resin composition according to claim 1, wherein the glass transition temperature of the resin composition is 70 ° C. or higher. 3. The resin composition according to claim 1, wherein a blending ratio of (A) polylactic acid resin and (B) methacrylic resin is 59/41 to 10/90. The resin composition according to any one of claims 1 to 3, wherein the resin composition has a melt flow rate measured at 190 ° C and a load of 21.2 N of 30 g / 10 min or less and 0.1 g / 10 min or more. . The molded article which consists of a resin composition of any one of Claims 1-4. The molded article according to claim 5, wherein the molded article is one of an injection molded article, an extrusion molded article, a blow molded article, and a film.