JP2007145955A - Method of preparing resin composition and resin molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of preparing a resin composition capable of yielding a resin molded product excellent in water resistance while retaining its mold processability, and to provide a resin molded product with a reduced environmental load and an improved water resistance. <P>SOLUTION: A resin composition is prepared by alloying an aliphatic polyester resin with a thermoplastic resin and a graft copolymer of an ethylene/glycidyl methacrylate copolymer and an acrylonitrile/styrene copolymer and subsequently adding an epoxy resin to this. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a resin composition and a resin molded product.

  During the quarter century, polymer chemistry and technology have advanced greatly, and many high-performance and high-performance polymer materials have been created. Among polymer materials, plastics are currently consumed over 100 million tons per year all over the world, and are used for electrical equipment, automobile parts and various structures. Since plastic mainly uses petroleum as a raw material, there is a concern about the depletion of resources, and since it is not decomposed in the natural environment, there is a possibility that waste increases and adversely affects the environment. Petroleum-derived plastics are cited as one of the causes of global warming that has been screamed in recent years. Therefore, biodegradable resin compositions using natural resources as raw materials instead of petroleum-derived plastics are attracting attention.

  Examples of the biodegradable resin composition include aliphatic polyester resins typified by polylactic acid, but most of the aliphatic polyester resins are hydrolyzed in a natural environment or in vivo, and finally It is completely decomposed into water and carbon dioxide. For this reason, although it has the advantage that the load with respect to an environment or a living body becomes small, since an aliphatic polyester resin is easy to be hydrolyzed, there is a problem in water resistance, and even if it is used as it is, it is difficult to put it into practical use.

For example, there is an example in which the hydrolysis resistance of the polyester resin is improved by adding a thermosetting epoxy resin to the polyester resin. Further, a glass fiber, a glass, and a glass fiber are used for a mixture of a thermoplastic polyester resin mainly composed of polybutylene terephthalate, an ABS resin, a graft copolymer of an ethylene-glycidyl methacrylate copolymer and an acrylonitrile-styrene copolymer. A thermoplastic resin composition having improved mechanical properties and low warpage properties by containing flakes and antimony trioxide is also disclosed (Patent Document 1).
JP-A-9-194699

  However, none of the resin compositions described above are intended for biodegradable resin compositions.

  As described above, the biodegradable resin composition is an aliphatic polyester resin typified by polylactic acid, although it is considered promising as having a low environmental burden and high practicality. It was easy. Therefore, in order to impart hydrolysis resistance, it is necessary to increase the amount of epoxy resin added to the aliphatic polyester resin, but when the amount of epoxy resin added is increased, molding processability such as injection molding Had the risk of lowering.

  The present invention has been made in order to solve the above problems, that is, the method for producing the resin composition of the present invention includes an aliphatic polyester resin, a thermoplastic resin, an ethylene-glycidyl methacrylate copolymer, and acrylonitrile. The gist is to add an epoxy resin after alloying the graft copolymer with the styrene copolymer.

  In addition, the resin molded product of the present invention can be used among the extrusion molding, pressure molding, vacuum molding, injection molding, blow molding and foam molding, using the resin composition obtained from the method for producing a resin composition described above. The gist is that it was molded using any method selected.

  According to the method for producing a resin composition of the present invention, water resistance can be improved while maintaining the processability of the resin composition during injection molding.

  According to the resin molded product of the present invention, it is possible to reduce the environmental load and at the same time increase the water resistance.

  Hereinafter, a method for producing a resin composition and a resin molded product according to the present invention will be described.

  The resin molded product according to the present invention is manufactured by the process shown in FIG. As shown in FIG. 1, first, a thermoplastic resin, a graft copolymer of an ethylene-glycidyl methacrylate copolymer and an acrylonitrile-styrene copolymer are kneaded at a temperature of 230 ° C. to 260 ° C., and softened. The primary kneaded product was made easy (primary kneading (step 1a)), and then the obtained primary kneaded product and the aliphatic polyester resin were kneaded to give a secondary kneaded product (secondary kneading (step 1b)). A polyester resin, a thermoplastic resin, and a graft copolymer of an ethylene-glycidyl methacrylate copolymer and an acrylonitrile-styrene copolymer are chemically bonded (step 1).

  Thereafter, an epoxy resin is further added to obtain a resin composition (Step 2), and the obtained resin composition is subjected to any method of extrusion molding, vacuum molding, pressure molding, injection molding, blow molding or foam molding. To form a resin molded product (step 3).

  In step 1, as described above, it is preferable to knead in two stages. This is because if the aliphatic polyester resin is heated to 230 ° C. or higher, thermal decomposition is likely to occur, and if all of the resin to be alloyed is kneaded at once, the aliphatic polyester resin may be thermally decomposed. By kneading in two stages as described above, thermal deterioration of the resin composition is suppressed. In addition, it is good to use a twin screw extruder at the time of resin kneading | mixing.

  In step 2, an epoxy resin that imparts hydrolysis resistance was added. However, when the epoxy resin was added during the production of the polymer alloy in step 1 to increase the thermal history, the epoxy resin caused a three-dimensional crosslinking reaction, and at the time of molding. This is because workability is lowered. Therefore, in order to shorten the thermal history of the epoxy resin as much as possible, it is effective to add the epoxy resin immediately before molding in the step 3. Moreover, it is preferable that the addition amount of an epoxy resin shall be 0.5%-15%. This is because when the amount of the epoxy resin added is less than 0.5%, sufficient hydrolysis resistance cannot be obtained, and conversely, when it exceeds 15%, the mechanical properties deteriorate significantly.

  Then, after preparing a polymer alloy by the process 2, by adding an epoxy resin, it becomes possible to provide hydrolysis resistance without deteriorating mechanical properties. The addition amount of the epoxy resin is preferably 0.5% to 15%. This is because when the addition amount of the epoxy resin is less than 0.5%, the hydrolysis resistance is lowered, and conversely, when the addition amount exceeds 15%, the mechanical properties are remarkably lowered.

  In step 3, it is preferable to mold at a molding temperature of 150 ° C to 220 ° C. If the molding temperature becomes too low, a short circuit occurs, the molding becomes unstable, the inside of the injection molding machine tends to be overloaded, and if the molding temperature becomes high, thermal decomposition occurs and the strength of the resulting molded product decreases. In addition, problems such as further coloring occur. The mold temperature is preferably 20 ° C to 120 ° C. When the mold temperature is in the range of 20 ° C to 90 ° C, the mold releasability is improved. When the mold temperature is in the range of 90 ° C to 120 ° C, crystallization proceeds in a short time, and the heat distortion temperature Also gets higher.

  The method for producing a resin composition according to the present invention includes the step 1 and the step 2 described above.

  Next, the resin to be alloyed in step 1 will be described. An aliphatic polyester resin, a thermoplastic resin, and a graft copolymer of ethylene-glycidyl methacrylate copolymer and acrylonitrile-styrene copolymer, which are compatibilizers, are essential components of the resin composition. Specific examples will be given.

  The aliphatic polyester resin is not particularly limited, but polylactic acid, polybutylene succinate, lactic acid component and aliphatic polyester resin, polyglycolic acid, polycaprolactone, polyhydroxyalkanoate, and the like can be used. It can be used alone or in combination of two or more. Among the exemplified aliphatic polyesters, when polylactic acid is included, crystallinity is increased, and moldability and productivity are improved. For this reason, from the viewpoint of mechanical properties and moldability, it is preferable to use polylactic acid alone or a mixture of polylactic acid and one or more other aliphatic polyester resins.

  The thermoplastic resin is not particularly limited, but polybutylene terephthalate resin, acrylonitrile / butadiene rubber / styrene resin, polycarbonate resin, resin obtained by alloying polycarbonate with acrylonitrile / butadiene rubber / styrene resin, polyether sulfone resin, It is preferable to use polyphenylene ether resin, methacryl styrene resin, acrylonitrile / styrene resin, polyethylene resin, methacryl resin, or thermoplastic elastomer resin. One kind selected from these or two or more kinds can be used in combination. Further, depending on the application, those reinforced with inorganic materials such as glass fibers, plant fibers, etc., or those flame-retarded with non-bromine, non-chlorine, and non-antimony materials can be used. The thermoplastic resin is not particularly limited, but is preferably added at a rate of 10 to 40% by mass of the aliphatic polyester resin. By adding an amorphous thermoplastic resin, mechanical strength such as impact resistance can be improved. If the amount of the aliphatic polyester resin added is less than 10% by mass, sufficient mechanical strength such as impact resistance cannot be obtained. Conversely, if it exceeds 40% by mass, the heat history during heat processing increases. This is because the thermal decomposition of the aliphatic polyester resin occurs.

  The graft copolymer of ethylene-glycidyl methacrylate copolymer and acrylonitrile-styrene copolymer is a compatibilizing agent that enhances the compatibility between the aliphatic polyester resin and the thermoplastic resin. In particular, this compatibilizing agent is used. It has been found to be effective. The compatibilizer is preferably added at a ratio of 1 to 30% by mass. If the compatibilizer is less than 1% by mass, the mechanical strength decreases as the compatibility decreases. Conversely, if the amount of the compatibilizer exceeds 30% by mass, the mechanical strength of the compatibilizer itself decreases. This is because the heat resistance is adversely affected.

  Furthermore, the resin composition to be alloyed as described above has a nucleating agent that promotes crystallization, an antioxidant that suppresses decomposition due to oxidation, a photodegradation inhibitor that suppresses photodegradation, and flame retardancy, as necessary. You may add the flame retardant to give, a flame retardant adjuvant, the substance which improves impact resistance, or the external lubricant which improves mold mold release property.

  The nucleating agent is not particularly limited, but talc, organically modified layered silicate causing delamination, silica, sodium 2,2-methylenebis (4,6-di-tert-butylphenyl) phosphate, phosphorus Sodium bis (4-t-Bu-phenyl) acid, rosin crystal nucleating agent, graphite, carbon black, zinc oxide, magnesium oxide, magnesium sulfate, barium sulfate, calcium benzoate, calcium oxalate, magnesium stearate, zinc salicylate , Aluminum dibenzoate, potassium benzoate, lithium benzoate, sodium β-naphthalate sodium cyclohexanecarboxylate, poly-3-methylbutene-1, polyvinylcycloalkane, polyvinyltrialkylsilane, EPR, Kevlar fiber, kaolin, montmorilloid, oxidation Aluminum, acid Neodymium iodide, high melting point nylon, hydroxy-di (t-Bubenzoic acid) aluminum, and the like can be used, and these may be used alone or in combination of two or more. Here, the reason why the organically modified layered silicate causing delamination is added is that a crystallization promoting effect can be obtained and a reinforcing effect can be obtained by adding a small amount.

  Although it does not specifically limit as antioxidant, A general phenolic antioxidant or phosphorus antioxidant can be used.

  Although it does not specifically limit as a photodegradation inhibitor, Various ultraviolet absorbers or hindered amine antioxidant can be used.

  Although it does not specifically limit as a flame retardant, You may use the flame retardant compound containing phosphorus from a non-bromine, non-chlorine, and a non-antimony viewpoint. Examples of flame retardant compounds containing phosphorus include resorcinol bis (2,6-dimethylphenyl phosphate), phosphazene compounds, melamine polyphosphate compounds, guanidine phosphate compounds, trimethyl phosphate, triethyl phosphate, tributyl phosphate, tris (2 -Ethylhexyl) phosphate, tris (butoxyethyl) phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, cresyl di-2,6-xylenyl phosphate, various aromatics Condensed phosphate compound, 10-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (2,5-dihydroxyphenyl) -10-hydro 9-oxa-10-phospha-phenanthrene-10-oxide, ammonium polyphosphate may be mentioned red phosphorus. Further, as flame retardants, inorganic substances including hydrates such as aluminum hydroxide, magnesium hydroxide, basic magnesium sulfate hydrate, etc., and other inorganic substances such as layered graphite may be added. Two or more types may be used in combination.

  Although it does not specifically limit as a flame retardant adjuvant, For example, a silicon | silicone, a silicone type acrylic reinforcement agent, a zinc borate, a polytetrafluoroethylene etc. are mentioned, 1 type selected from these, or 2 or more types combined May be used together.

  Examples of the substance for improving impact resistance include polymethyl methacrylate-polybutyl acrylate-polydimethylsiloxane copolymer, polyalkyl methacrylate-polybutadiene-polystyrene copolymer, and various thermoplastic elastomers. However, it is not particularly limited.

  External lubricants include alkyl methacrylate, alkyl acrylate copolymer, ester of aliphatic alcohol and dicarboxylic acid, ester of glycerin and other short chain long aliphatic alcohol and fatty acid, fatty acid, fatty acid amide, metal soap, oligomeric fatty acid Esters, esters of aliphatic alcohols and fatty acids, montanic acid and esters and soaps, polar polyethylene waxes, nonpolar polyethylene waxes, fluoropolymers, natural or synthetic paraffins, and the like can be used.

  Examples of the epoxy resin include glycidyl ether type, glycidyl amine type, and glycidyl ester type. Among them, glycidyl ether type is generally used. The glycidyl ether type epoxy resin can be roughly classified into a bifunctional repeating structure type, a polyfunctional repeating structure type, and a polyfunctional monomer type according to its basic structure. It is preferable to use a polyfunctional repeating structure type. Here, the reason why the polyfunctional epoxy resin is suitable is that the addition amount of the epoxy resin can be reduced by having many functional groups in one molecule. Specifically, 1,1,2,2-tetra (p-hydroxyphenyl) ethane tetraglycidyl ether (product name: EPON1031, manufacturer name: Japan Epoxy Resin), 2- [4- (2,3-epoxy) Propoxy) phenyl] -2- [4- [1,1-bis [4-([2,3-epoxypropoxy] phenyl) ethyl] phenyl] propane and 1,3-bis [4- [1- [4- (2,3-epoxypropoxy) phenyl] -1- [4-[-1 [4- (2,3-epoxypropoxyphenyl) -1-methylethyl] phenyl] ethyl] phenoxy] -2-propanol (product name Techmore VG3101, manufacturer name; Mitsui Chemicals). Furthermore, an epoxy resin containing three glycidyl groups in one molecule is preferable. For example, a cresol novolac type epoxy resin (ECN, EPICRON N-600 series, manufactured by Dainippon Ink Co., Ltd.) can be used. .

  Furthermore, although it demonstrates using an Example concretely, of course, it is not limited to the illustrated Example.

Example 1
First, 30 parts by weight of polybutylene terephthalate (Toraycon 1200S, manufactured by Toray Industries, Inc.) and poly (ethylene-stat-glycidyl methacrylate) -graft-poly (acrylonitrile-stat-styrene) (Modiper A4400, NOF Corporation )) And 26 parts by weight of an alkyl methacrylate-butadiene-styrene copolymer resin (Methbrene C-223A, manufactured by Mitsubishi Rayon Co., Ltd.) at 13.8 parts by weight, (Primary kneading).

  Next, 100 parts by weight of polylactic acid (Lacia H-100J, manufactured by Mitsui Chemicals Co., Ltd.), 20 parts by weight of talc (TT talc, manufactured by Takehara Chemical Co., Ltd.), Adeka Stub AO330 (as an antioxidant) Asahi Denka Co., Ltd.) 0.4 parts by weight, Adeka Stub 2112 (Asahi Denka Co., Ltd.) 0.4 parts by weight, and nucleating agent (trade name Adeka Stub NA-11, Asahi Denka Co., Ltd.) 1 weight 0.4 parts by weight of an external lubricant (trade name: Metabrene L-1000, manufactured by Mitsubishi Rayon Co., Ltd.) and a primary kneaded product obtained by primary kneading are added and kneaded at 210 ° C. The kneaded material is kneaded using a kneader (S-1 kneader, manufactured by Kurimoto Steel Co., Ltd.) under conditions of a kneading temperature of 200 ° C, a rotation speed of 100 rpm, and a discharge rate of 3-4 kg / hr. Product (secondary kneading).

  After that, 21.3 parts by weight of novolac epoxy resin (EPICLON N695, manufactured by Dainippon Ink Co., Ltd.) was added to the obtained secondary kneaded product, and the cylinder temperature was set at a nozzle with an injection molding machine (160 tons manufactured by Nissei Plastic Industry Co., Ltd.). Molding was performed with the part 210 ° C., the front part 210 ° C., the middle part 210 ° C., and the rear part 200 ° C., and the mold temperature set to 25 ° C.

Example 2
In place of the polybutylene terephthalate resin used in Example 1, acrylonitrile / butadiene / styrene resin (Psycolac ABS resin, manufacturer name UMG ABS) was used. Got.

Example 3
Instead of the polybutylene terephthalate resin used in Example 1, a resin obtained by alloying polycarbonate resin and acrylonitrile butadiene styrene resin (Psycolac ABS resin, manufacturer name UMG ABS) (Techniace T-105, Nippon A & L) A sample was obtained using the same method as in Example 1 except that.

Example 4
Instead of the polybutylene terephthalate resin used in Example 1, a thermoplastic polyetherester elastomer (Hytrel 5557, manufactured by Toray DuPont Co., Ltd.) was used, and the sample was prepared using the same method as in Example 1 except that. Obtained.

Comparative Example 1
A sample was obtained using the same method as in Example 1 except that the novolac epoxy resin used in Example 1 was added during the secondary kneading.

Comparative Example 2
A sample was obtained using the same method as in Example 2, except that the novolak epoxy resin used in Example 2 was added during the secondary kneading.

Comparative Example 3
A sample was obtained using the same method as in Example 3 except that the novolac epoxy resin used in Example 3 was added during the secondary kneading.

Comparative Example 4
A sample was obtained using the same method as in Example 4 except that the novolac epoxy resin used in Example 4 was added during the secondary kneading.

  For Examples 1 to 4 and Comparative Examples 1 to 4 described above, the melt flow rate (unit: g / 10 min) was measured at a measurement temperature of 220 ° C. using the pellets immediately after kneading, and the injection moldability was evaluated.

Table 1 shows the evaluation results.

  As shown in Table 1, when the example and the comparative example in which only the timing of adding the novolak epoxy resin was changed without changing the components of the resin composition were compared, the value of the melt flow rate in the example was 5 g / Whereas it is 10 min or more, the melt flow rate value of the comparative example is less than 5 g / 10 min, indicating that the injection moldability of the example is better than that of the comparative example. Among the examples, in particular, when acrylonitrile / butadiene / styrene resin (Example 2) or thermoplastic polyetherester elastomer (Example 4) is used as the thermoplastic resin, the injection moldability is extremely good. There was found.

It is a figure which shows the manufacturing process of the resin molded product which concerns on this invention.

Explanation of symbols

1a: primary kneading,
1b ... secondary kneading,
2 ... Addition of epoxy resin,
3 ... Molding,

Claims (5)

  An aliphatic polyester resin, a thermoplastic resin, an ethylene-glycidyl methacrylate copolymer and a graft copolymer of acrylonitrile-styrene copolymer are alloyed, and then an epoxy resin is added to form a resin composition. The manufacturing method of the resin composition characterized by these.   The method for producing a resin composition according to claim 1, wherein the aliphatic polyester resin contains polylactic acid.   The method for producing a resin composition according to claim 1 or 2, wherein the epoxy resin contains three glycidyl groups in one molecule.   The thermoplastic resin is composed of polybutylene terephthalate resin, acrylonitrile / butadiene rubber / styrene resin, polycarbonate resin, resin obtained by alloying polycarbonate with acrylonitrile / butadiene rubber / styrene, and polycarbonate / thermoplastic polyether ester elastomer. The method for producing a resin composition according to any one of claims 1 to 3, comprising at least one selected from the resins made.   A resin composition obtained from the method for producing a resin composition according to any one of claims 1 to 4, wherein the resin composition is any one of extrusion molding, pressure molding, vacuum molding, injection molding, blow molding and foam molding. Resin molded product molded using

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