JP5483833B2 - Heat resistance improver, thermoplastic resin composition and molded product - Google Patents

Description

  The present invention relates to a heat resistance improver, a thermoplastic resin composition, and a molded article.

Resin materials have been widely used in various applications such as parts for automobiles, home appliances, office automation equipment, etc., but in recent years, the resin used as a raw material has been changed from conventional petroleum resins to non-petroleum systems due to increasing social interest in environmental issues. Social demand to change to resin is increasing.
However, since non-petroleum resins are inferior in performance as compared to petroleum-based resins, improvements have been attempted by blending with other non-petroleum resins.
For example, a cellulose derivative is a non-petroleum resin produced from a plant-derived raw material such as wood and has excellent mechanical properties. Therefore, it has been conventionally applied to a shaping method using an organic solvent, etc. in the field of fibers, films, etc. It is used in. However, for example, cellulose acetate has a high melting temperature and excellent heat resistance, but since the difference between the melting temperature and the thermal decomposition temperature is small, it cannot be melt-molded alone and has a problem of poor moldability. .
Polylactic acid can be produced from plant-derived raw materials such as corn and sweet potato, and has excellent mechanical properties and moldability, but has problems such as poor heat resistance.

Thus, attempts have been made to obtain a non-petroleum thermoplastic resin composition having excellent heat resistance and moldability by blending polylactic acid and a cellulose derivative. However, when polylactic acid and a cellulose derivative such as cellulose acetate are melt blended, the meltability of the cellulose derivative in the resulting thermoplastic resin composition is not sufficient, and the cellulose derivative is contained in the raw material form. Therefore, the appearance of the obtained molded product is not sufficient.
Patent Document 1 proposes a polylactic acid resin composition comprising polylactic acid and a cellulose ester such as cellulose acetate propionate. However, the heat resistance of the obtained molded product is not sufficient.
International Publication No. 2004/087812 Pamphlet

  The object of the present invention is to use a heat resistance improver capable of improving the heat resistance of a thermoplastic resin such as polylactic acid, and a thermoplastic resin composition in which this heat resistance improver is blended with a thermoplastic resin. Another object of the present invention is to provide a thermoplastic resin composition that is excellent in heat resistance and moldability so that the cellulose derivative does not remain in the raw material shape when formed into a molded product.

The present invention is obtained by polymerizing vinyl monomer (a2) 60 to 1% by mass (total of (a1) and (a2) is 100% by mass) in the presence of 40 to 99% by mass of cellulose derivative (a1). The present invention relates to a thermoplastic resin composition containing 10 to 70% by mass of a polymer (A) and 90 to 30% by mass of a thermoplastic resin (B) containing polylactic acid.

  According to the present invention, a non-petroleum thermoplastic resin composition having excellent heat resistance and moldability can be provided, and an alternative to a conventional petroleum thermoplastic resin as a thermoplastic resin material used for parts of automobiles, home appliances, office automation equipment, etc. Can be promoted.

Hereinafter, the present invention will be described in detail.
As a cellulose derivative (a1) used by this invention, what substituted the functional group of the cellulose by chemical reaction can be used.
The cellulose derivative (a1) is preferably a cellulose ester obtained by esterifying all or part of the hydroxyl groups of cellulose in consideration of the heat resistance and moldability of the resulting thermoplastic resin composition.

Examples of the cellulose ester include cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. These may be used alone or in combination of two or more.
Among the above compounds, cellulose acetate is preferred in view of the heat resistance of the resulting thermoplastic resin composition. In addition, the degree of acetylation of cellulose acetate is preferably 40 to 62%, more preferably 50 to 61%.

  Examples of the vinyl monomer (a2) used in the present invention include methyl (meth) acrylate, ethyl (meth) acrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, n-propyl acrylate, n-butyl acrylate, and cyanoethyl. (Meth) acrylate monomers such as acrylate and cyanobutyl acrylate; fluorinated (meth) acrylate monomers such as 2,2,2-trifluoroethyl methacrylate; aromatic vinyl monomers such as styrene and α-methylstyrene Body; vinyl cyanide monomers such as acrylonitrile; and (meth) acrylic acid. These may be used alone or in combination of two or more.

Of the above compounds, methyl (meth) acrylate, acrylonitrile and acrylic acid are preferred in view of the heat resistance of the resulting thermoplastic resin composition.
In the present invention, (meth) acrylate represents acrylate or methacrylate, and (meth) acrylic acid represents acrylic acid or methacrylic acid.

In the present invention, the polymer (A) is obtained by polymerizing the vinyl monomer (a2) in the presence of the cellulose derivative (a1).
As a use ratio of the cellulose derivative (a1) and the vinyl monomer (a2), when the total of the cellulose derivative (a1) and the vinyl monomer (a2) is 100% by mass, the cellulose derivative (a1) is 40%. It is preferable that -99 mass% and a vinyl monomer (a2) shall be 60-1 mass%, a cellulose derivative (a1) is 70-95 mass%, and a vinyl monomer (a2) is 30-5 mass%. More preferably.

Examples of the polymerization method for obtaining the polymer (A) include known methods. In a batch, semi-batch or continuous reaction system, in a solvent-free or in solution, or in a suspension or emulsion system, a radical is used. Various polymerization methods such as a polymerization method, an anionic polymerization method, a cationic polymerization method, and a transition metal catalyst polymerization method can be employed.
As an example of the method for producing the polymer (A), there is a method in which the vinyl monomer (a2) and the radical polymerization initiator are added to the cellulose derivative (a1) suspended in water, followed by radical polymerization by heating. It is done.

The polymerization temperature for obtaining the polymer (A) is 0 to 150 ° C, preferably 65 to 90 ° C. Moreover, as superposition | polymerization time for obtaining a polymer (A), it is 1 to 10 hours, for example. The polymer (A) can be produced under a nitrogen atmosphere as necessary.
In the polymerization for obtaining the polymer (A), known additives such as a chain transfer agent, a dispersant, a dispersion aid, and an emulsifier can be used as necessary.

Examples of the radical polymerization initiator include t-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, benzoyl peroxide, di-t-butyl peroxide, di-t-amyl peroxide, di-t-hexyl peroxide, organic peroxides such as t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxybenzoate, diisopropylperoxycarbonate; potassium persulfate, ammonium persulfate And azo compounds such as azobisisobutyronitrile and azobis-2,4-dimethylvaleronitrile. These may be used alone or in combination of two or more.
Among the above compounds, t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, t-butyl peroxy-2-ethylhexanoate, potassium persulfate, ammonium persulfate, azobisisobutyronitrile and azobis 2,4-dimethylvaleronitrile is preferred. Moreover, said organic peroxide and persulfate can also be used as a redox system in combination with a reducing agent.

Examples of the chain transfer agent include octyl mercaptan and dodecyl mercaptan.
Examples of the dispersant include polyvinyl alcohol, sodium polyacrylate, and polyethylene oxide. Examples of the dispersion aid include sodium sulfate, sodium carbonate, hydrogen peroxide solution, and boric acid.
As the emulsifier, known anionic emulsifiers, cationic emulsifiers and nonionic emulsifiers can be used.

In the present invention, the compound containing the polymer (A) can be added to the thermoplastic resin (B) described later and used as a heat resistance improver for improving the heat resistance.
In the present invention, the compound containing the polymer (A) is produced by injection molding of the thermoplastic resin (B) by utilizing the change in melting characteristics caused by adding the polymer (A) to the thermoplastic resin (B). It can be used as a moldability modifier in extrusion molding, blow molding and the like.

  In the present invention, for example, when a thermoplastic resin (B) having a large difference in melt viscosity such as polylactic acid and polycarbonate is used in combination, these compounds can be added by adding a compound containing the polymer (A). The difference in the melt viscosity of the resin can be reduced and the miscibility can be improved.

  Examples of the thermoplastic resin (B) used in the present invention include acrylic resins such as polymethyl methacrylate and methyl methacrylate-acrylate copolymer; polystyrene, high impact polystyrene, acrylonitrile-styrene resin, acrylonitrile-butadiene- Styrene resins such as styrene resin, styrene-butadiene copolymer, hydrogenated styrene-butadiene copolymer; polypropylene, low density polyethylene, linear low density polyethylene, high density polyethylene, ethylene-propylene copolymer, cyclic olefin Olefin resins such as containing polymers; aromatic polyesters such as polyethylene terephthalate, polytrimethylene glycol terephthalate, polybutylene terephthalate; polycarbonates; and polylactic acid, polycaprolac Emissions, aliphatic polyesters such as polybutylene succinate. These may be used alone or in combination of two or more.

  Considering the moldability and heat resistance of the obtained thermoplastic resin composition among the above copolymers or resins, high impact polystyrene, acrylonitrile-butadiene-styrene resin, polypropylene, low density polyethylene, linear low Density polyethylene, high density polyethylene, ethylene-propylene copolymer, polycarbonate, polylactic acid, polycaprolactone and polybutylene succinate are preferred, and acrylonitrile-butadiene-styrene resin, ethylene-propylene copolymer, polycarbonate and polylactic acid are more preferred. Preferably, polylactic acid is more preferable.

As polylactic acid, a polymer containing D-form lactic acid and / or L-form lactic acid as a main raw material can be used. In addition, if the formation of polylactic acid crystals is confirmed by observation with a polarizing microscope or the like under appropriate conditions such as temperature and time, crystalline polylactic acid can be used, and those that are not confirmed can be used as amorphous polylactic acid. .
Examples of crystalline polylactic acid include a polymer of L-lactic acid and a polymer of D-lactic acid, and these may be used alone or in combination of two or more.
Examples of the amorphous polylactic acid include a copolymer of D-form lactic acid and L-form lactic acid.

In the case of crystalline polylactic acid, components other than lactic acid can be copolymerized as long as the crystallinity is maintained, and in the case of amorphous polylactic acid, the amorphous property is maintained. Examples of components other than lactic acid include aliphatic hydroxycarboxylic acids, aliphatic diols, and aliphatic dicarboxylic acids. Examples of the form of copolymerization include random copolymerization, block copolymerization, and graft copolymerization.
As a commercial item of crystalline polylactic acid, a brand name "Lacia H-100" (made by Mitsui Chemicals, Inc.) is mentioned, for example.
As a commercial item of amorphous polylactic acid, a brand name "Lacia H-280" (made by Mitsui Chemicals, Inc.) is mentioned, for example.

The thermoplastic resin composition of the present invention contains a polymer (A) and a thermoplastic resin (B).
As a ratio of the polymer (A) and the thermoplastic resin (B) in the thermoplastic resin composition of the present invention, when the total of the polymer (A) and the thermoplastic resin (B) is 100% by mass, It is preferable that a polymer (A) is 10-70 mass% and a thermoplastic resin (B) is 90-30 mass%, a polymer (A) is 25-65 mass%, and a thermoplastic resin (B) is 75. More preferably, it is -35 mass%.

In the thermoplastic resin composition of the present invention, known additives such as a plasticizer (C), an antioxidant, a light stabilizer, a flame retardant, glass fiber, carbon fiber, talc, calcium carbonate, kenaf are included as necessary. In addition, fillers such as bacterial cellulose, pigments, and the like can be blended.
Examples of the plasticizer (C) include polyhydric alcohol plasticizers, polybasic acid ester plasticizers, polyester plasticizers, phosphate ester plasticizers, epoxy plasticizers, fatty acid plasticizers, and sulfonic acid plasticizers. Agents. Among these, polyhydric alcohol plasticizers and polybasic acid ester plasticizers are preferable, and polyhydric alcohol plasticizers are more preferable.

  Examples of the polyhydric alcohol plasticizer include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, poly (ethylene glycol / propylene glycol) block and / or random copolymer, 1,3- Butanediol, 1,4-butanediol, polytetramethylene glycol, pentanediol, hexanediol, decanediol, neopentyl glycol, bisphenol, glycerin, diglycerin, polyglycerin, erythritol, pentaerythritol, dipentaerythritol, xylitol, mannitol Sorbitol, ethylene oxide addition polymer, and propylene oxide addition polymer.

In addition, derivatives of these polyhydric alcohols can also be used. Examples of the polyhydric alcohol derivative include triethylene glycol di- (2-ethylbutyrate), triethylene glycol di- (2-ethylhexoate), triethylene glycol dibenzoate, polyethylene glycol di- (2-ethyl). (Hexoate), dibutylmethylene bis-thioglycolate, glycerol monoacetate, glycerol diacetate, glycerol triacetate, glycerol tributyrate, glycerol tripropionate, glycerol diacetomonocaprate, glycerol monoacetomonolaurate, glycerol diacetomono Olate, glycerin monoricinoleate triacetate, glycerin monoacetomonomontanate, polyoxyethylene glycerin triacetate, diglycerin tetraacetate, poly Glycerine monolaurate acetate.
As a commercial item of a polyhydric alcohol type plasticizer, brand name "Likemar PL-019", "same PL-710" (above, Riken Vitamin Co., Ltd. product) is mentioned, for example.

Examples of the polybasic acid ester plasticizer include di-n-butyl adipate, diisobutyl adipate, di- (2-ethylhexyl) adipate, diisooctyl adipate, diisodecyl adipate, octyldecyl adipate, dicapryl adipate, benzyl n-butyl Adipates such as adipate, polypropylene adipate, polybutylene adipate, dibutoxyethyl adipate, benzyloctyl adipate; dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, diamyl phthalate, dihexyl phthalate, butyl octyl phthalate, butyl isodecyl phthalate , Butyl lauryl phthalate, di- (2-ethylhexyl) phthalate, di-n-octyl phthalate, di-2- Cutyl phthalate, dilauryl phthalate, diheptyl phthalate, diisooctyl phthalate, octyl decyl phthalate, n-octyl, n-decyl phthalate, diisodecyl phthalate, ditridecyl phthalate, ethylhexyl decyl phthalate, dinonyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate Phthalic acid esters such as di-n-butyl maleate, dimethyl maleate, diethyl maleate, di- (2-ethylhexyl) maleate, dinonyl maleate, etc .; dibutyl fumarate, di- (2-ethylhexyl) fumarate, etc. Fumarate ester; tri- (2-ethylhexyl) trimellitate, triisodecyl trimellitate, triisooctyl trimellitate, diisooctyl monoi Trimellitic acid esters such as decyl trimellitate and the like.
As a commercial item of a polybasic acid ester plasticizer, for example, trade names “MXA”, “BXA”, “DAIFATTY-101” (manufactured by Daihachi Chemical Industry Co., Ltd.), trade names “PX-844”. (Manufactured by ADEKA Corporation).

Examples of polyester plasticizers include acid components such as adipic acid, sebacic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, propylene glycol, 1,3-butanediol, 1,4-butanediol. , Polyesters composed of diol components such as 1,6-hexanediol, ethylene glycol and diethylene glycol; polyesters composed of hydroxycarboxylic acid such as polycaprolactone.
Examples of the phosphate plasticizer include triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trioctyl phosphate, triphenyl phosphate, diphenyl-2-ethylhexyl phosphate, trixyl phosphate, and tricresyl phosphate.

Examples of the epoxy plasticizer include butyl epoxy stearate, epoxy monoester, octyl epoxy stearate, epoxidized butyl oleate, di- (2-ethylhexyl) 4,5-epoxycyclohexane-1,2-carboxylate, Epoxidized semi-drying oil, epoxidized triglyceride, epoxy butyl stearate, epoxy octyl stearate, epoxy decyl stearate, epoxidized soybean oil, epoxidized linseed oil, methyl epoxy hydrostearate, glyceryl tri- (epoxy acetoxy systemate) And isooctyl epoxy stearate.
Examples of the fatty acid plasticizer include methyl oleate, butyl oleate, methoxyethyl oleate, tetrahydrofurfuryl oleate, glyceryl monooleate, diethylene glycol monooleate, methyl acetyl ricinoleate, butyl acetyl ricinolate, glyceryl mono ricinoleate, diethylene glycol mono ricino. Examples thereof include rate, glyceryl tri- (acetylricinoleate), alkylacetylricinoleate, n-butyl stearate, glyceryl monostearate, diethylene glycol distearate, and diethylene glycol monolaurate.

Examples of the sulfonic acid plasticizer include benzenesulfone butyramide, o-toluenesulfonamide, p-toluenesulfonamide, N-ethyl-p-toluenesulfonamide, o-tolueneethylsulfonamide, p-tolueneethylsulfonamide. , N-cyclohexyl-p-toluenesulfonamide.
These plasticizers (C) may be used individually by 1 type, and may use 2 or more types together.

When using a plasticizer (C) in this invention, the usage-amount is 5-40 mass% with respect to a thermoplastic resin composition (100 mass%), and 10-30 mass% is more preferable.
If the amount of the plasticizer (C) used is 5% by mass or more with respect to the thermoplastic resin composition (100% by mass), the resulting molded article exhibits sufficient flexibility, and if it is 40% by mass or less. The plasticizer does not bleed out from the obtained molded product.

The thermoplastic resin composition of the present invention can be obtained by blending the polymer (A), the thermoplastic resin (B), and various additives as required by a known method.
Examples of the blending method of the polymer (A), the thermoplastic resin (B), and various additives include a batch kneader method and a blending method using a single-screw or multi-screw extruder.

The thermoplastic resin composition of the present invention can be used for production of various molded products by applying known molding methods such as extrusion molding, injection molding, press molding, inflation molding, calendar molding and the like.
The molded article using the thermoplastic resin composition of the present invention can be used for various applications such as parts for automobiles, home appliances, and OA equipment.

  Hereinafter, the present invention will be described specifically by way of examples. In the following, “part” and “%” represent “part by mass” and “% by mass”, respectively. Moreover, evaluation was implemented with the following method.

(1) Blended state The polymer (A) or the cellulose derivative and a thermoplastic resin were melt blended, and the presence or absence of the cellulose derivative in the raw material shape in the obtained thermoplastic resin composition was evaluated by visual observation.

(2) Heat resistance The heat resistance of the obtained thermoplastic resin composition was measured by the following two methods to evaluate the heat resistance.
(A) Vicat softening temperature Based on ASTM-D1525, it measured by load 10N or 50N.
(B) Deflection temperature under load Based on ASTM-D648, it was measured at a load of 0.48 MPa.

(3) Formability The obtained molded product was returned to the mold again and heat-treated using a hot press machine. The shape retention of the molded product immediately after the heat treatment was evaluated according to the following criteria.
Good: Even if the molded product was taken out from the mold immediately after the heat treatment, the molded product was not deformed.
Defect: When the molded product is taken out from the mold immediately after the heat treatment, the molded product is deformed.
(To take out the molded product without deformation, it was necessary to cool the mold.)

(4) Film-forming property 0.5 g of the obtained thermoplastic resin composition was heated using a heating press machine (hydraulic press machine manufactured by Oji Machinery Co., Ltd., maximum load 37 tons, maximum operating pressure 210 kg / cm ² ). In a metal frame, while heating at a plate temperature of 180 ° C., a gauge pressure of 30 kg / cm ² was added to form a thickness of 100 to 150 μm, cooled to near room temperature, and then taken out. The film forming property of the obtained molded film was evaluated according to the following criteria.
Good: The obtained film was smooth.
Defect: The obtained film was wavy.

(5) Film flexibility With respect to the flexibility of the obtained film, changes due to heat treatment were evaluated.
First, it was confirmed that the film before heat treatment was able to conform to the shape of the side surface from the bottom surface inside the cup having a diameter of 70 cm and a depth of 85 cm, and was able to be used as a packaging material. Next, after heat-treating the film at 60 ° C. for 2 hours, an attempt was made to conform to the shape inside the cup again, and the film was evaluated according to the following criteria.
Good: The film remained flexible even after heat treatment, and was able to conform to the shape of the side surface from the bottom surface inside the cup, maintaining a level that could be used as a packaging material.
Defect: The film lost flexibility with heat treatment and could not conform to the shape of the side surface from the bottom surface inside the cup, making it difficult to use as a packaging material.

[Production Example 1] Production of polymer (A-1) In a reaction vessel equipped with a stirrer, a cooling tube, a heating device, a temperature sensor and a quantitative supply device, 500 parts of deionized water, flaky cellulose acetate (Daicel Chemical) 90 parts of L-40 (trade name) manufactured by Co., Ltd., acetylation degree 55% were charged. While stirring the charged contents at room temperature, 9.8 parts of methyl methacrylate, 0.2 part of methyl acrylate, 0.02 part of n-octyl mercaptan and t-butylperoxy-2-ethylhexanoate were added to the reaction vessel. 0.2 part of the mixture was added over 30 minutes.
After stirring for another 30 minutes, the reaction contents were heated to 80 ° C. and stirred for 4 hours. Thereafter, the final contents were cooled, the solid matter was taken out and dried to obtain a polymer (A-1).

[Production Examples 2 and 3] Production of Polymers (A-2) and (A-3) Polymers (A-2) and (A-3) were produced in the same manner as Production Example 1 except that the raw material composition of the polymer shown in Table 1 was used. (A-3) was obtained.

[Examples 1 to 4]
The polymers (A-1) to (A-3) and polylactic acid (Lacia H-100 (trade name) manufactured by Mitsui Chemicals, Inc.) obtained in Production Examples 1 to 3 are shown in Table 2, Using a kneader (Plastic coder (trade name) manufactured by Brabender Co., Ltd., internal volume 50 cm ³ ), melt blending was performed at a barrel temperature of 220 ° C. to obtain thermoplastic resin compositions (I) to (D). The blended state of cellulose acetate in the thermoplastic resin compositions (i) to (d) at this time was evaluated. The evaluation results are shown in Table 2.
Next, the obtained thermoplastic resin compositions (a) to (d) were melted at a cylinder temperature of 220 ° C. using a tabletop injection molding machine (CS-183 (trade name) manufactured by Custom Scientific Instruments), Injected into the mold. After cooling the mold to room temperature, a molded product (length 2 cm × width 1 cm × thickness 0.2 cm) was taken out from the mold.

Although heat resistance was evaluated using the obtained molded product, in Examples 1, 3, and 4, since the Vicat softening temperature was lower than 70 ° C., heat treatment was attempted as follows.
The obtained molded product was returned to the mold again and heat-treated at 105 ° C. for 5 minutes using a heating press machine (hydraulic press machine manufactured by Oji Machinery Co., Ltd., maximum load 37 tons, maximum working pressure 210 kg / cm ² ). . The heat treatment was carried out at a gauge pressure of 10 kg / cm ² on a hot press machine.
Immediately after the heat treatment, the molded product was taken out of the mold, and the moldability at this time was evaluated. Moreover, heat resistance was evaluated using the molded product after heat treatment. The evaluation results are shown in Table 2.

  In Example 2, since the Vicat softening temperature of the obtained molded product was higher than 70 ° C., the obtained molded product was directly used (without heat treatment) to evaluate the heat resistance. The evaluation results are shown in Table 2.

  The thermoplastic resin composition containing the polymer (A) was excellent in heat resistance and moldability. Moreover, when the content rate of the cellulose derivative (a1) in a polymer (A) is high, the heat resistance of the thermoplastic resin composition obtained was especially excellent. Moreover, when the content rate of the cellulose derivative (a1) in a thermoplastic resin composition is high, the obtained thermoplastic resin composition was excellent in heat resistance, without heat processing.

[Comparative Examples 1 and 2]
Only polylactic acid (Lacia H-100 (trade name) manufactured by Mitsui Chemicals, Inc.) was used as a raw material composition of the thermoplastic resin composition, and melt blending was performed in the same manner as in Example 1 except that. Next, the heat resistance and moldability of the molded product obtained in the same manner as in Example 1 were evaluated for the case without heat treatment and the case with heat treatment. The evaluation results are shown in Table 2.
In the resin composition of polylactic acid alone, the heat resistance of the obtained molded product was inferior. Further, the molded product immediately after the heat treatment was inferior in moldability and deformed when taken out from the mold. For this reason, the heat resistance of the molded product after heat treatment is not measured.

[Comparative Example 3]
Instead of the polymer (A-1), 25 parts of cellulose acetate (L-40 (trade name) manufactured by Daicel Chemical Industries, Ltd., acetylation degree 55%) was blended, and the blending amount of polylactic acid was 75 parts. Otherwise in the same manner as in Example 1, a thermoplastic resin composition (e) was obtained. It was visually confirmed that cellulose acetate was contained in the thermoplastic resin composition (e) in the raw material form. The evaluation results are shown in Table 2.
In the case of melt blending with polylactic acid using cellulose acetate instead of the polymer (A), a thermoplastic resin composition having a good blend state could not be obtained.

[Comparative Example 4]
Instead of the polymer (A-1), 25 parts of cellulose acetate propionate (CAP-504-0.2 (trade name) manufactured by Eastman Chemical Co.) was blended, and the blending amount of polylactic acid was 75 parts. Otherwise in the same manner as in Example 1, a thermoplastic resin composition (f) was obtained. The blend state of cellulose acetate propionate in the thermoplastic resin composition (f) at this time was evaluated. The evaluation results are shown in Table 2.

Next, the obtained thermoplastic resin composition (f) was molded using a desktop injection molding machine in the same manner as in Example 1 to produce a molded product. The obtained molded product was heat-treated in the same manner as in Example 1 to evaluate the moldability. The evaluation results are shown in Table 2. In addition, about the molded article after heat processing, since it deform | transformed when taking out from a metal mold | die, heat resistance is not measured.
When melt blended with polylactic acid using cellulose acetate propionate instead of the polymer (A), the moldability was poor.

[Example 5]
The polymer (A-1) and polylactic acid (Laisia H-100 (trade name) manufactured by Mitsui Chemicals, Inc.) obtained in Production Example 1 were used in a twin-screw extruder (Co., Ltd.) with the composition shown in Table 3. Using a plastic engineering laboratory BT30 (trade name)), melt blending was performed at a barrel temperature of 220 ° C. to obtain a thermoplastic resin composition (g). The blended state of cellulose acetate in the thermoplastic resin composition (g) at this time was evaluated. The evaluation results are shown in Table 3.

Next, the obtained thermoplastic resin composition (g) was maintained at a cylinder temperature of 190 ° C., a mold surface temperature of 105 ° C., and an injection molding machine (IS-30 (trade name) manufactured by Toshiba Machine Co., Ltd.). A molded product having a length of 2 cm, a width of 1 cm and a thickness of 0.2 cm was produced under injection molding conditions for 5 minutes. The obtained molded product was used to evaluate heat resistance. The evaluation results are shown in Table 3.
When the thermoplastic resin composition containing the polymer (A) was used for injection molding, the resulting molded product was excellent in heat resistance and moldability.

[Comparative Example 5]
Only polylactic acid (Lacia H-100 (trade name) manufactured by Mitsui Chemicals, Inc.) was used as the raw material composition of the thermoplastic resin composition, and the other components were injection molded in the same manner as in Example 5. The evaluation results are shown in Table 3. The resulting molded product could not be removed from the mold due to poor shape retention.

[Comparative Example 6]
The injection molding conditions were changed to a mold surface temperature of 30 ° C. and a holding time of 2 minutes. Otherwise, injection molding was performed in the same manner as in Comparative Example 5. The evaluation results are shown in Table 3.
When polylactic acid was injection-molded alone without using the polymer (A), the resulting molded product was inferior in heat resistance.

[Example 6]
Polymer (A-1) obtained in Production Example 1, polylactic acid (Lacia H-100 (trade name) manufactured by Mitsui Chemicals, Inc.) and acrylonitrile-butadiene-styrene copolymer (UMG-ABS Co., Ltd.) Psycholac 3001 (trade name)) is melt-blended at a barrel temperature of 220 ° C. using a kneader (Plastic coder (trade name) manufactured by Brabender, product volume 50 cm ³ ) with the composition shown in Table 4, and is thermoplastic. A resin composition (H) was obtained. The blend state of the cellulose acetate in the thermoplastic resin composition (h) at this time was evaluated. The evaluation results are shown in Table 4.

Next, the obtained thermoplastic resin composition (H) was melted at a cylinder temperature of 220 ° C. using a tabletop injection molding machine (CS-183 (trade name) manufactured by Custom Scientific Instruments) and placed in a mold. Ejected. After cooling the mold to room temperature, a molded product (length 2 cm × width 1 cm × thickness 0.2 cm) was taken out from the mold.
The obtained molded product was used directly (without heat treatment) to evaluate the heat resistance. The evaluation results are shown in Table 4.
The thermoplastic resin composition containing the polymer (A) is excellent in heat resistance despite containing a non-petroleum resin, and when the conventional ABS resin of Reference Example 1 described later is used. It was the same level as.

[Reference Example 1]
Obtained in the same manner as in Example 6 except that only the acrylonitrile-butadiene-styrene copolymer (Psycolac 3001 (trade name) manufactured by UMG-ABS) is used as the raw material composition of the thermoplastic resin composition. The molded product was directly used (without heat treatment) to evaluate the heat resistance. The evaluation results are shown in Table 4.

[Comparative Example 7]
Polylactic acid (Lacia H-100 (trade name) manufactured by Mitsui Chemicals, Inc.) and acrylonitrile-butadiene-styrene copolymer (UMG-ABS Co., Ltd., Psycolac 3001 (trade name) are used as the raw material composition of the thermoplastic resin composition. )) Alone, and a thermoplastic resin composition (Li) was obtained in the same manner as in Example 6 except that.
The obtained molded product was used directly (without heat treatment) to evaluate the heat resistance. The evaluation results are shown in Table 4.
When the polymer (A) was not used, the thermoplastic resin composition composed of polylactic acid and acrylonitrile-butadiene-styrene resin was inferior in heat resistance.

[Examples 7 to 9]
Polymer (A-1) obtained in Production Example 1, polylactic acid (Laissia H-100 manufactured by Mitsui Chemicals, Inc., H-280 (trade name)), plasticizer (Rikemar PL manufactured by Riken Vitamin Co., Ltd.) 019, PL-710 (trade name)) with the composition shown in Table 5, using a kneader (Plastic coder (trade name) manufactured by Brabender, internal volume 50 cm ³ ), melt blended at a barrel temperature of 220 ° C., Thermoplastic resin compositions (nu) to (wo) were obtained.
Table 5 shows the evaluation results of the obtained thermoplastic resin composition.
The thermoplastic resin composition comprising the polymer (A), polylactic acid, and plasticizer was excellent in film formability and flexibility.

[Comparative Examples 8 and 9]
Polylactic acid (Laisia H-100 manufactured by Mitsui Chemicals Co., Ltd., H-280 (trade name)) and plasticizer (Rikumar PL-019 (trade name) manufactured by Riken Vitamin Co., Ltd.), with the composition shown in Table 5, Using a kneader (Plasticcoder (trade name) manufactured by Brabender Co., Ltd., internal volume 50 cm ³ ), melt blending was performed at a barrel temperature of 180 ° C. to obtain thermoplastic resin compositions (wa) and (f).
Table 5 shows the evaluation results of the obtained thermoplastic resin composition.
The thermoplastic resin composition composed of polylactic acid and a plasticizer without using the polymer (A) was inferior in film formability and flexibility.

  As apparent from the above results, the thermoplastic resin composition of the present invention uses the polymer (A) obtained by polymerizing the vinyl monomer (a2) in the presence of the cellulose derivative (a1). Therefore, it has excellent heat resistance and moldability despite containing non-petroleum resin.

Claims (1)

Cellulose derivative (a1) Polymer obtained by polymerizing vinyl monomer (a2) 60-1% by mass (total of (a1) and (a2) is 100% by mass) in the presence of 40-99% by mass ( A) 10 to 70% by mass;
A thermoplastic resin composition containing 90-30% by mass of a thermoplastic resin (B) containing polylactic acid .