JPS5815516A - Production of thermoplastic resin - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin excellent in heat resistance, impact resistance and heat stability, by emulsion-polymerizing a rubbery polymer and an alkenyl aromatic monomer in the presence of an alkenyl aromatic compound/unsaturated dicarboxylic acid anhydride copolymer. CONSTITUTION:A rubbery polymer and an alkenyl aromatic monomer or a mixture thereof with a copolymerizable vinyl monomer is emulsion-polymerized in the presence of an alkenyl aromatic compound/unsaturated dicarboxylic acid anhydride copolymer with the content of unsaturated dicarboxylic acid anhydride of 5-35wt%. If this content is below 5wt%, it is impossible to improve heat resistance, whereas if it exceeds 35wt%, the heat stability is lowered. As the unsaturated dicarboxylic acid anhydride, maleic anhydride is particularly prelerred. As the alkenyl aromatic compound, styrene is particularly preferred. It is also possible to use a vinyl cyanide monomer, in combination, for the purpose of improving the impact resistance of the alkenyl aromatic compound/unsaturated dicarboxylic acid anhydride copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a thermoplastic resin having high heat resistance, good impact resistance and thermal stability.

A copolymer obtained by graft polymerizing styrene and acrylonitrile in the presence of a butadiene-based rubbery polymer is generally called an ABS resin and is widely used in fields requiring impact resistance, high gloss, etc.

However, the current situation is that it does not have sufficient heat resistance and is subject to major restrictions in fields where heat resistance is required.

On the one hand, styrene-maleic anhydride copolymer is used for the purpose of improving the heat resistance of ABS resin, which is generally well known as a resin with high heat resistance, and on the other hand, for the purpose of imparting impact resistance to styrene-maleic anhydride copolymer. , a composition of ABS resin and a styrene-maleic anhydride copolymer has been proposed.

However, although such compositions have improved heat resistance, their impact resistance is low, and their thermal stability, especially if the resin remains in the molding machine during high-temperature molding, can significantly reduce the gloss, and in some cases, the gloss may be almost completely absent. be.

As described above, the heat resistance of fiABs resin can be improved by blending styrene-maleic anhydride copolymer with ABS resin, but this composition has poor impact resistance and thermal stability, and is rarely used. is the current situation.

The inventors of the present invention have conducted intensive studies on thermoplastic resins that have good heat resistance, impact resistance, and thermal stability. It has been discovered that these drawbacks can be improved by polymerizing , and the present invention has been achieved based on this knowledge.

That is, the present invention provides a rubbery polymer and an alkenyl aromatic monomer in the presence of an alkenyl aromatic compound-unsaturated dicarboxylic anhydride copolymer having an unsaturated dicarboxylic anhydride content of 5 to 35% by weight. The present invention provides a method for producing a thermoplastic resin, which is characterized by emulsion polymerization of a thermoplastic resin or a mixture thereof with a vinyl monomer copolymerizable with the thermoplastic resin.

The content of unsaturated dicarboxylic anhydride in the alkenyl aromatic compound-unsaturated dicarboxylic anhydride copolymer used in the present invention is 5 to 35% by weight, preferably 10 to 35% by weight.
It is 17% by weight.

If it is less than 5% by weight, the heat resistance will not be improved, while if it is less than 35% by weight.
If the temperature exceeds 100%, the thermal stability decreases.

Examples of unsaturated dicarboxylic anhydrides include maleic anhydride, chloromaleic anhydride, dichloromaleic anhydride, citraconic anhydride, itaconic anhydride, phenylmaleic anhydride, aconitic anhydride, etc. Maleic acid is preferred.

Examples of alkenyl aromatic compounds include styrene, α-methylstyrene, P-methylstyrene, 0-methylstyrene,
Examples include nuclear-substituted halogenated styrene and indene, with styrene being particularly preferred.

A vinyl cyan monomer can be used in combination for the purpose of improving the impact resistance of the alkenyl aromatic compound-unsaturated dicarboxylic anhydride copolymer. As the vinyl cyan monomer, acrylonitrile, methacrylate trile, etc. are used, and the amount used is 0 to 30% by weight, and if it exceeds 30% by weight, coloring becomes severe.

The intrinsic viscosity of the alkenyl aromatic compound-unsaturated dicarboxylic anhydride copolymer (at 30° C., in a methyl ether ketone solvent) is not particularly limited, but is usually preferably 0.35 to 0.60.

Examples of rubbery polymers include butadiene-based rubbery polymers containing butadiene as a main component (for example, butadiene homopolymer rubber,
Styrene-butadiene copolymer rubber, butadiene-(meth)acrylic acid copolymer rubber, acrylonitrile-butadiene copolymer rubber), chloroprene rubbery polymer, imprene rubbery polymer, natural rubber, chlorinated polyethylene,
Examples include ethylene-propylene rubbery polymers, ethylene-diene rubbery polymers, and cycloolefin rubbery polymers.

In particular, butadiene-based rubbery polymers are preferred.

The alkenyl aromatic monomer used in the emulsion polymerization is the same as the alkenyl aromatic compound described above.

Examples of vinyl monomers that can be copolymerized with alkenyl aromatic monomers include vinyl cyanide monomers and (meth)acrylic acid ester monomers. The same one is used. In addition, (meth)acrylic acid ester monomers include methyl methacrylate,
Examples include methyl acrylate and ethyl methacrylate.

The preferable proportions of each component in the thermoplastic resin obtained by the method of the present invention are 5 to 70% by weight of the alkenyl aromatic compound-unsaturated dicarboxylic acid anhydride copolymer and 5 to 70% by weight of the rubbery polymer. , and a mixture of an alkenyl aromatic monomer or a vinyl monomer copolymerizable with these is 2
It is 5 to 90% by weight.

After the alkenyl aromatic compound-unsaturated dicarboxylic acid anhydride copolymer is dissolved in the alkenyl aromatic monomer used in emulsion polymerization, an emulsifier, water, etc. are added, and the mixture is vigorously stirred using, for example, a homomixer. It is preferably added to the polymerization system after emulsification. At this time, it is desirable that the particle size of the micelles be 10 μm or less, preferably 4 μm or less.

When an alkenyl aromatic compound-unsaturated dicarboxylic acid anhydride copolymer is dissolved in an alkenyl aromatic monomer or the like, an organic solvent may be used in combination to aid dissolution. Examples of organic solvents include ebuluene, methyl ethyl ketone,
These include xylene, benzene, chloroform, and chlorobenzenate.

As the emulsifier, anionic emulsifiers, nonionic emulsifiers, or cationic emulsifiers are used, and particularly preferred are anionic emulsifiers such as sodium salts or potassium salts of disproportionated rosin acids, sodium salts or potassium salts of fatty acids. .

As the polymerization initiator, all those commonly used in emulsion polymerization can be used. For example, persulfates such as potassium persulfate and ammonium persulfate, organic peroxides such as cumene hatrobaroxide and diisopropylbenzene hydroperoxide, azo compounds such as azobisisobutyronitrile, and organic peroxides and cocatalysts. Sulfoxylate formulations used in combination with sugar-containing iron birophosphate formulations are also used.

Furthermore, molecular weight regulators such as t-dodecyl mercaptan and terpinolene can also be used, and substances necessary for the reaction can be used as appropriate.

The obtained polymer contains a known antioxidant, such as 2,6-di-t-butyl-4-methylphenol, 2-(1-methylcyclohexyl)-4,6-dimethylphenol,
2.2'-methylenebis-(4-ethyl-6-t-butylphenol), 4.4'-thiobis-(6-1-butyl-3-methylphenol), dilaurylthiodipropionate, tris(cynonyl) phenyl) phosphite,
Wax, n-octadecyl-3-(4°-hydroxy-3',5'-di-t-butylphenyl)propionate, known ultraviolet absorbers, such as evap-t-buterphenyl salicylate, 2. 2“-dihydroxy-4-
Methoxybenzophenone, 2-(2'-hydroxy-4
+ n-octoxyphenyl)benzotriazole,
Known lubricants such as paraffin wax, stearic acid, lead stearate, calcium stearate, magnesium stearate, barium stearate, aluminum stearate, hydrogenated oil, stearamide, edelene bis stearamide, methylene bis stearamide, n-
Butyl stearate, ketone wax, octyl alcohol, lauryl alcohol, hydroxystearic acid triglyceride, silicone oil, known flame retardants such as antimony oxide, aluminum hydroxide, zinc oxalate, tricresyl phosphate, tris(dichloropropyl) phosphate. -), chlorinated paraffin, tetrabromobutane, hexabromophthane, hexabromobenzene, tetrabromobisphenol A1 Known antistatic agent, e.g. stearamidopropyl dimethyl-β-hydroxyethylammonium nitrate, known coloring Agents such as titanium oxide, carbon black, other inorganic and organic pigments, and known fillers such as calcium carbonate, clay, silica, glass fibers, glass spheres, and carbon fibers are used as appropriate.

It is also possible to obtain a foamed molded product using a foaming agent.

Furthermore, the thermoplastic resins obtained by the present invention include butadiene-acrylonitrile copolymer, styrene-acrylonitrile copolymer, vinyl chloride polymer, styrene-maleic anhydride copolymer, AB8 resin, polyphenylene oxide, epoxy resin, polycarbonate. , chlorinated butyl rubber, polyester such as polybutylene terephthalate,
It may be used by appropriately blending it with polyacetal, polyamide, polyfluorinated bicarbonate, polysulfone, acrylic polymer, and the like.

Next, the present invention will be explained in more detail with reference to Examples.

Styrene-maleic anhydride copolymers used in Examples and Comparative Examples were obtained by the following method.

Styrene-maleic anhydride copolymer-1 1326 g of styrene 1 maleic anhydride 1 in a stainless steel reactor with a stirring device
0.7g was charged. After replacing the internal air with nitrogen,
Oil (110°C) was placed in the jacket and heated. When the internal temperature of the reactor reached 80℃, maleic anhydride 20 was added to the left roller.
9.8 gs) A solution consisting of 1412 g of toluene, 1 g of benzoyl peroxide and 172 g of toluene were added using a variable flow rate continuous addition device so as to match the polymerization conversion rate of styrene. When the polymerization conversion rate reached 80 degrees, the addition of maleic anhydride and benzoyl peroxide was stopped, and the polymer solution was added to isopropyl alcohol, followed by sufficient drying in a vacuum dryer to obtain a polymer.

Maleic anhydride in the polymer was 14.3% by weight.

Styrene-maleic anhydride copolymer - styrene-maleic anhydride except for the amounts of styrene and maleic anhydride prepared in batches 2, 3, and 4, and the maleic anhydride oxygen used in the increment as shown in Table 1. Acid copolymer-
A polymer was obtained in the same manner as in Example 1.

Table 1 Example-1 First, 1000 g of polybutadiene latex (as solid content) was charged into a stainless steel reactor equipped with a stirrer, and then 11500 g of styrene-maleic anhydride copolymer was dissolved in 1050 g of styrene and 450 g of acrylonitrile. Disproportionated potassium rosinate 45g 1 water 6000g,
10 g of t-dodecyl mercaptan and 2 potassium hydroxide were added, stirred in a homomixer until the size of micelles became 1 μm or less, and the mixture was added to the polybutadiene latex. After replacing the air inside with nitrogen, hot water was poured into the jacket and heated. When the internal temperature of the reactor reached 40 DEG C., a solution of 10 g of sodium pyrophosphate, 125 g of glucose and 0.2 g of ferrous sulfate dissolved in 500 g of water and 5 g of cumenohydroboroxide were added. Keep the hot water in the jacket at 70℃ while stirring the mixture.3
The reaction was allowed to proceed for 0 minutes. Subsequently, after dissolving 11,500 g of styrene-maleic anhydride copolymer in 1,050 g of styrene and 450 g of acrylonitrile N, 10 g of t-dodecyl mercaptan, 2 g of potassium hydroxide, 45 g of potassium disproportionated rosinate, and 3,500 g of water were added, and the size of micelles was mixed with a homomixer. After stirring until the size of the spoon becomes 1 μ or less, add 5 g of cumenno idroba oxide to the emulsified mixture.
The addition was continued over a period of 5 hours.

The polymerization conversion rate was 94%, the maleic anhydride content in the finally obtained polymer was 6.3%, and the rubber weight was 147% by weight.The obtained polymer latex was coagulated with sulfuric acid. After washing with water and dehydrating, the pellets were thoroughly dried, and 34 g of barium stearate was added and mixed, and pellets were formed using a 40111φ extruder. After drying, the pellets were used using an injection molding machine to obtain test pieces for measuring the following physical properties.

Impact resistance: Notched Izo impact strength was measured according to ASTM D256.

Heat resistance; Load 1 & 61 according to ASTM D648
The heat distortion temperature of 1/cII was measured.

Thermal Stability: The polymer was allowed to stay in a molding machine at 280°C for 15 minutes to obtain a 2X50x50M molded article and compared in gloss 5 with a molded article at 280°C without residence. A color meter manufactured by Suga Test Instruments was used to measure the gloss.

Example-2 In Example-1, polybutadiene latex was
Polymerization was carried out in the same manner as in Example 1, except that 3108 g% of styrene-maleic anhydride copolymer-2 was used in the batch polymerization and 3108 g in the increment polymerization.

The amount of rubber, maleic anhydride content, and evaluation results in the obtained polymer are shown in Table 2.

Comparative Examples-1 and 2 Same as Example-1 except that styrene-maleic anhydride copolymer-3 and 4 were used instead of styrene-maleic anhydride copolymer-1 used in Example-1. Polymerization was carried out.

The results are shown in Table 2.

Comparative Example-3 Polymerization was carried out in the same manner as in Example-1 except that monomaleic anhydride copolymer-1 was not used.

The results are shown in Table 2.

Comparative Example-4 Styrene-maleic anhydride copolymer-1 in Example
The same results as in Example 1 were obtained for a composition in which 13000 g of styrene-maleic anhydride copolymer was mixed with 3820 g of polymer obtained by polymerization in the same manner as in Example 1, except that 13,000 g of styrene-maleic anhydride copolymer was Shown in the table.

Comparative Example-5 213 g of polybutadiene was charged into a stainless steel reactor equipped with a stirring device, and then 1,326 g of styrene and 10.7 g of maleic anhydride were added to dissolve the polybutadiene.

After replacing the internal air with nitrogen, 209.8 g of maleic anhydride was continuously added in the same manner as in the method for obtaining styrene-maleic anhydride copolymer-1, and polymerization was carried out until the polymerization conversion rate reached 80%. did.

The amount of rubber, maleic anhydride content, and evaluation results in the obtained polymer are shown in Table 2.

Margin below

Claims (1)

[Claims] In the presence of an alkenyl aromatic compound-unsaturated dicarboxylic anhydride copolymer having an unsaturated dicarboxylic anhydride content of 5 to 35% by weight, a rubbery polymer and an alkenyl aromatic monomer or further copolymerized therewith are added. A method for producing a thermoplastic resin, comprising emulsion polymerization of a mixture with a polymerizable vinyl monomer.