JP2008297461A - Thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition composed of a biodegradable resin and a rubber-reinforced styrene-based resin, excellent in the balance of impact resistance, heat resistance and durability under a high-temperature and high-humidity environment. <P>SOLUTION: The thermoplastic resin composition comprises (A) 1-99 wt.% biodegradable resin and (B) 99-1 wt.% rubber-reinforced styrene-based resin, and the rubber-reinforced styrene-based resin (B) is composed of (b-1) a rubber-reinforced styrene-based resin produced by emulsion polymerization and a rubber-reinforced styrene-based resin (b-2) produced by block polymerization and/or solution polymerization. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin composition. Specifically, the present invention relates to a thermoplastic resin composition having an excellent balance of impact resistance, heat resistance, and durability under a high temperature and high humidity environment.

In recent years, as an environmental problem on a global scale, the future of petroleum resources due to increased use of petrochemical products has been threatened. For example, polylactic acid resin is a resin made of lactic acid obtained from plant corn and moss as a raw material, and is known as an environmentally friendly resin that is biodegradable but does not use petroleum as a raw material. However, the polylactic acid resin is concerned with durability that can withstand long-term use, particularly in a high humidity environment, due to its biodegradability, and has the disadvantages of being inferior in notched impact strength and heat resistance.
On the other hand, ABS resins have excellent physical property balance and molding processability, and are used in a wide range of fields.
For this reason, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2000-327847) includes a polymer having an aliphatic polyester structure and a polyolefin containing an ABS resin to improve a polymer that collapses in a natural environment. Has been proposed. However, these compositions have an insufficient balance of physical properties such as impact resistance, and there is a risk of resin collapse or deterioration during molding and use of molded products in a high humidity environment. When the blending ratio of the functional resin is large, it is not necessarily a satisfactory material.
In JP-A-2006-45485 (Patent Document 2) and JP-A-2006-45486 (Patent Document 3), a resin composition excellent in impact resistance, moist heat resistance, and the like comprising polylactic acid and a specific ABS resin. Things have been proposed, but further improvements are desired.
JP 2000-327847 A JP 2006-45485 A JP 2006-45486 A JP 2005-60637 A

  An object of the present invention is to provide a resin composition having an excellent balance between impact resistance and heat resistance of a composition comprising a biodegradable resin and a rubber-reinforced styrene resin and durability under a high temperature and high humidity environment. It is what.

  That is, the present invention provides a thermoplastic resin composition comprising 1 to 99% by weight of the biodegradable resin (A) and 99 to 1% by weight of the rubber-reinforced styrene resin (B), B) is composed of a rubber-reinforced styrene resin (b-1) produced by emulsion polymerization and a rubber-reinforced styrene resin (b-2) produced by bulk polymerization and / or solution polymerization. A thermoplastic resin composition is provided.

  The resin composition of the present invention has an effect of excellent balance between impact resistance, heat resistance, and durability under a high temperature and high humidity environment.

Hereinafter, the thermoplastic resin composition of the present invention will be described in detail.
The biodegradable resin (A) in the present invention is a polyester resin, such as polylactic acid, polybutylene succinate, polybutylene succinate adipate, polybutylene succinate terephthalate, polyethylene succinate, and polybutylene succinate. Examples thereof include polyalkylene succinates such as nate carbonate, polyglycolic acid, polycaprolactone, polyhydroxybutyric acid, polyhydroxyvaleric acid, hydroxybutyric acid, and hydroxyvaleric acid copolymer. Of these, polylactic acid, polybutylene succinate, polybutylene succinate adipate, polybutylene succinate terephthalate, and polyethylene succinate are preferable. Examples of these biodegradable resins available on the market include, for example, products manufactured by Mitsui Chemicals, Inc., trade names: Reiacia, manufactured by Unitika Ltd., trade names: Terramac, manufactured by Showa Polymer Co., Ltd., trade names: Bionore, manufactured by BASF Name: Ecoflex, DuPont brand name Biomax, Nippon Shokubai Co., Ltd. Brand name: Lunare, Mitsubishi Gas Chemical Co., Ltd. Trade name: Upek etc.

  The rubber reinforced styrene resin (B) in the present invention is a rubber reinforced styrene resin (b-1) produced by emulsion polymerization and a rubber reinforced styrene resin produced by bulk polymerization and / or solution polymerization ( b-2).

The rubber-reinforced styrene resin (b-1) produced by emulsion polymerization in the present invention is an aromatic vinyl compound and a copolymerizable copolymer in a rubber-like polymer latex using a known emulsion polymerization method. It can obtain by adding the vinyl compound of this and superposing | polymerizing.
However, in the present invention, the rubber-reinforced styrene resin (b-1) is preferably coagulated with an organic acid or an organic acid and an alkaline earth metal salt from the viewpoint of durability. Examples of organic acids include hydrochloric acid, sulfuric acid, nitric acid, acetic acid, and alkaline earth metal salts include magnesium sulfate, calcium sulfate, magnesium nitrate, calcium nitrate, magnesium acetate, calcium acetate, magnesium chloride, and chloride. Examples include calcium.
The rubbery polymer used in the present invention includes polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block polymer, acrylic rubber mainly composed of butyl acrylate or ethyl acrylate, ethylene -At least one selected from propylene (diene) polymer, silicon rubber, chlorinated polyethylene, nitrile rubber, urethane rubber, isoprene rubber and the like. In particular, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block polymer, acrylic rubber mainly composed of butyl acrylate or ethyl acrylate, and ethylene-propylene (diene) polymer are preferable. Most preferred is a styrene-butadiene copolymer. Further, these rubbery polymers can be appropriately used after agglomeration and enlargement treatment by a known method.

Examples of the aromatic vinyl compound used in the present invention include styrene, α-methylstyrene and the like, and these can be used alone or in combination.
Other copolymerizable vinyl compounds include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, (meth) acrylic acid ester compounds such as methyl methacrylate and methyl acrylate, maleimide, and N-phenylmaleimide. Such as maleimide compounds, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid and maleic acid, unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride, and unsaturated such as glycidyl methacrylate and allyl glycidyl ether Examples thereof include hydroxyl group-containing unsaturated compounds such as epoxy compounds, hydroxyethyl acrylate, and hydroxyethyl methacrylate, which can be used alone or in combination of two or more.

  Although there is no restriction | limiting in particular in the composition ratio of each component which comprises rubber reinforcement | strengthening styrene-type resin (b-1), Rubber-like polymer 10-80 weight% and aromatic vinyl type compound 20-100 weight% and copolymerization are possible. It is preferable that the total amount of the compound consisting of 0 to 80% by weight of the other compounds is 90 to 20% by weight, particularly 10 to 80% by weight of the rubber-like polymer and 20 to 90% by weight of the aromatic vinyl compound. As other polymerizable compounds, 90 to 20% by weight of a compound (total) consisting of 10 to 80% by weight of a vinyl cyanide compound and / or a (meth) acrylic acid ester compound is preferable.

The rubber-reinforced styrene-based resin (b-2) produced by bulk polymerization and / or solution polymerization in the present invention is an aromatic vinyl-based compound obtained by converting a rubber-like polymer by a known bulk polymerization method and / or solution polymerization method. In addition, other vinyl compounds that can be copolymerized as required, and further, those obtained by dissolving in various solvents are polymerized.
The rubbery polymer, aromatic vinyl compound and other copolymerizable vinyl compound constituting the rubber reinforced styrene resin (b-2) are the same as those exemplified in the section (b-1). Things can be used.
Although there is no restriction | limiting in particular in the composition ratio of each component which comprises a rubber reinforced styrene-type resin (b-2), 5-30 weight% of rubber-like polymers, 20-100 weight% of aromatic vinyl-type compounds, and copolymerization are possible. The compound (total) consisting of 0 to 80% by weight of other compounds is preferably 95 to 70% by weight, particularly 5 to 30% by weight of a rubbery polymer, 20 to 90% by weight of an aromatic vinyl compound and The other compound that can be polymerized is preferably 95 to 70% by weight of a compound (total) composed of 10 to 80% by weight of a vinyl cyanide compound and / or a (meth) acrylic acid ester compound.

  Although there is no restriction | limiting in particular about the composition ratio (weight ratio) of a rubber reinforced styrene resin (b-1) and a rubber reinforced styrene resin (b-2), 1-50 / 99-50 from the surface of a physical-property balance. It is preferable that

The thermoplastic resin composition in the present invention comprises 1 to 99% by weight of the biodegradable resin (A) and 99 to 1% by weight of the rubber-reinforced styrene resin (B).
In the present invention, a part of the rubber-reinforced styrene-based resin (B) may be substituted with the (meth) acrylic acid ester (co) polymer (C) shown below and further polycarbodiimide (D). Is possible. Among these, in particular, by using the (meth) acrylic acid ester (co) polymer (C), the compatibility between the biodegradable resin (A) and the rubber-reinforced styrene resin (B) is improved. The durability is improved by using polycarbodiimide (D).
In addition, when using these components, said biodegradable resin (A) 1 to 99 weight%, rubber-reinforced styrene resin (B) 98.49 to 0.49 weight%, (meth) acrylic acid It is preferably composed of 0.5 to 30% by weight of the ester (co) polymer (C) and 0.01 to 10% by weight of the polycarbodiimide (D).

Said (meth) acrylic acid ester (co) polymer (C) is a (co) polymer formed by (co) polymerizing a (meth) acrylic acid ester monomer.
Examples of (meth) acrylic acid ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, and (meth) acrylic acid n. -Butyl, i-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate , (Meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid 2-hydroxyethyl, and the like.

  The polycarbodiimide (D) is a (co) polymer using one or more polyisocyanate compounds. Specific examples of the polyisocyanate include hexamethylene diisocyanate, xylene diisocyanate, cyclohexane diisocyanate, Examples include pyridine diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 1,5-naphthylene diisocyanate, and mixtures thereof. .

  In the present invention, if necessary, a part of the rubber-reinforced styrene-based resin (B) may be replaced with a styrene-acrylonitrile copolymer (AS) or an α-methylstyrene-acrylonitrile copolymer (αMS-ACN). , Methyl methacrylate-styrene copolymer (MS), methyl methacrylate-acrylonitrile-styrene copolymer (MAS), styrene-N-phenylmaleimide copolymer (S-NPMI), styrene-N-phenylmaleimide-acrylonitrile copolymer It may be substituted with other thermoplastic resins such as polymer (SAANPMI), polymethyl methacrylate, polycarbonate, polyamide (6-nylon, 11-nylon, etc.), polybutylene terephthalate, polyethylene terephthalate, etc. Antioxidants, UV absorbers, light stabilizers, Known additives such as antistatic agents, lubricants, dyes, pigments, plasticizers, flame retardants, release agents, reinforcing materials, fillers, and the like can be added.

  Examples of the method for mixing the biodegradable resin (A) and the rubber-reinforced styrene resin (B) in the present invention include a method using a known kneader such as a Banbury mixer or an extruder.

[Example]
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited by these.

Biodegradable resin (A)
A-1: Polylactic acid (LACEA H-400 manufactured by Mitsui Chemicals, Inc.)

Rubber reinforced styrene resin (B)
Rubber-reinforced styrene resin (b-1): Nitrogen-substituted polymerization reaction vessel, 50 parts by weight of polybutadiene latex (weight average particle size 0.3 μm, gel content 85%), 150 parts by weight of water, ethylenediaminetetraacetic acid disodium salt 0.1 part by weight, ferric sulfate 0.001 part by weight, sodium formaldehyde sulfoxylate 0.3 part by weight, heated to 60 ° C., 14 parts by weight acrylonitrile, 41 parts by weight styrene and cumene hydroperoxide 0 A mixture consisting of 2 parts by weight was continuously added over 3 hours and further polymerized at 60 ° C. for 2 hours to obtain a graft copolymer latex. Then, after salting out using 100 parts by weight of sulfuric acid as a salting-out agent with respect to 100 parts by weight (solid content) of the latex, 1.5 times the volume of water of rubber-reinforced styrene resin particles was added and stirred Then, after dehydrating and washing, it was dried to obtain a rubber-reinforced styrene resin (b-1).

  Rubber-reinforced styrene resin (b-2): Nitrogen-substituted polymerization reaction vessel, 50 parts by weight of polybutadiene latex (weight average particle size 0.3 μm, gel content 85%), 150 parts by weight of water, disodium salt of ethylenediaminetetraacetic acid 0.1 part by weight, ferric sulfate 0.001 part by weight, sodium formaldehyde sulfoxylate 0.3 part by weight, heated to 60 ° C., 14 parts by weight acrylonitrile, 41 parts by weight styrene and cumene hydroperoxide 0 A mixture of 2 parts by weight was continuously added over 3 hours, and further polymerized at 60 ° C. for 2 hours to obtain a graft copolymer latex. Then, after salting out using 3.0 parts by weight of magnesium sulfate as a salting-out agent with respect to 100 parts by weight (solid content) of the latex, adding 1.5 times the volume of water of rubber-reinforced styrene resin particles, After stirring and dehydrating and washing, drying was performed to obtain a rubber-reinforced styrene-based resin (b-2).

  Rubber-reinforced styrene resin (b-3): Polybutadiene latex (weight average particle size 0.3 μm, gel content 85%) 50 parts by weight, water 150 parts by weight, ethylenediaminetetraacetic acid disodium salt in a nitrogen-substituted polymerization reaction vessel 0.1 part by weight, ferric sulfate 0.001 part by weight, sodium formaldehyde sulfoxylate 0.3 part by weight, heated to 60 ° C., 14 parts by weight acrylonitrile, 41 parts by weight styrene and cumene hydroperoxide 0 A mixture of 2 parts by weight was continuously added over 3 hours, and further polymerized at 60 ° C. for 2 hours to obtain a graft copolymer latex. Thereafter, 100 parts by weight (solid content) of the latex was salted out using 0.5 parts by weight of sulfuric acid and 1.5 parts by weight of magnesium sulfate as a salting-out agent, and then 1.5% of rubber-reinforced styrene resin particles. Double volume of water was added, stirred, dehydrated and washed, and then dried to obtain a rubber-reinforced styrene resin (b-3).

Rubber Reinforced Styrene Resin (b-4): Plug flow tower reactor with a volume of 15 liters ("New Polymer Manufacturing Process" (Industry Research Committee, Koji Saeki / Shinzo Omi), page 185, Fig. 7.5 (B) Continuous polymerization in which one 10 liter complete mixing tank is connected in series to the same type of Mitsui Toatsu type reactor described in Cb / C0 = 0.955 divided into 10 stages. A co-rubber reinforced styrene resin (b-4) was produced using an apparatus.
50.8 parts by weight of styrene, 16.9 parts by weight of acrylonitrile, 22.4 parts by weight of ethylbenzene, 9.9 parts by weight of Nipol NS310S manufactured by Zeon, 0.38 parts by weight of t-dodecyl mercaptan, 1,1-bis (t -Butylperoxy) A raw material comprising 0.045 parts by weight of 3,3,5-trimethylcyclohexane was continuously supplied to the continuous polymerization apparatus to polymerize the monomer. The first plug flow tower reaction vessel was set to 95 ° C., and the second complete mixing vessel was set to 120 ° C. After supplying the polymerization solution from the second reaction tank to a devolatilizing apparatus comprising a preheater (180 to 270 ° C.) and a decompression chamber (5 kPaabs), a rubber-reinforced styrene resin (b-4) is obtained via an extruder. It was.

(Meth) acrylic acid ester (co) polymer (C)
C-1: Polymethyl methacrylate (Sumitex MG-SS manufactured by Sumitomo Chemical Co., Ltd.)
Polycarbodiimide (D)
D-1: Polycarbodiimide (Carbodilite LA-1 manufactured by Nisshinbo Industries, Inc.)
STY-NPMI : Styrene / N-phenylmaleimide copolymer (Denka IP MS-NC, manufactured by Electrochemical Co., Ltd.)
PC : Polycarbonate (manufactured by Sumitomo Dow Co., Ltd. Caliber 200-30)

[Examples 1-11, Comparative Examples 1-6]
The biodegradable resin (A), rubber-reinforced styrene resin (B), and other polymer are mixed in the blending ratio shown in Table 1, and melt-mixed at 220 ° C. using a 30 mm biaxial extruder, pellets Table 1 shows the results of preparing various test pieces with an injection molding machine and evaluating the physical properties. In addition, each evaluation method is shown below.

○ Workability: Melt index (220 ° C., 10 kg) was measured based on ISO 1133. Unit: g / 10 minutes.
○ Impact resistance: Based on ISO 179, a Charpy impact value with a notch was measured.
○ Heat resistance: Based on ISO 75, the deflection temperature under load of 1.8 MPa was measured.
○ Durability: A wet heat test was performed at 65 ° C. and 95% RH, and the time during which the tensile strength retention was 90% or less was defined as the durability performance.

  As described above, by combining a biodegradable resin and two types of rubber-reinforced styrene resins, a resin composition having an excellent balance of impact resistance, heat resistance, and durability in a high temperature and high humidity environment can be obtained. Therefore, it can be widely used in the vehicle field, home appliance field, building material field, sanitary field and the like.

Claims (4)

A thermoplastic resin composition comprising 1 to 99% by weight of a biodegradable resin (A) and 99 to 1% by weight of a rubber-reinforced styrene resin (B), wherein the rubber-reinforced styrene resin (B) is emulsion polymerized. A thermoplastic resin composition comprising a rubber-reinforced styrene resin (b-1) produced by the above-described method and a rubber-reinforced styrene resin (b-2) produced by bulk polymerization and / or solution polymerization. object. The thermoplastic resin composition according to claim 1, wherein the biodegradable resin (A) is polylactic acid. The heat according to claim 1 or 2, wherein the rubber-reinforced styrene resin (b-1) produced by emulsion polymerization is coagulated with an organic acid or an organic acid and an alkaline earth metal salt. Plastic resin composition. The composition ratio (weight ratio) of the rubber-reinforced styrene resin (b-1) and the rubber-reinforced styrene resin (b-2) is 1 to 50/99 to 50. Thermoplastic resin composition.