JPS6255546B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an impact-resistant resin composition with excellent gloss and thermoforming stability. ABS resin, which is generally represented as an impact-resistant resin, is a graft copolymer made by grafting styrene, acrylonitrile, etc. to polybutadiene or styrene-butadiene rubber (SBR), and styrene, acrylonitrile, etc.
Various grades containing the required substances are prepared by blending with copolymers such as acrylonitrile, but emulsion polymerization is one of the industrial manufacturing methods for obtaining the above-mentioned graft copolymers. Can be mentioned. However, although the emulsion polymerization method has excellent polymerization reaction control and production stability, it consumes a large amount of water and electricity in the coagulation process, washing process, drying process, etc. Since it is extremely difficult to remove impurities such as agents, there are major problems such as poor gloss and poor thermoforming stability. The present inventors utilized the advantages of emulsion polymerization as a method for producing a graft copolymer, and as a result of their studies to solve these problems, they completed the present invention. In the present invention, an acidic substance or an electrolyte substance is added to a graft polymer latex obtained by emulsion polymerization of an ethylenic monomer or an ethylenic monomer mixture to a rubber-like polymer to cause partial coagulation, and then the ethylenic monomers are partially coagulated. It is obtained by sequentially or simultaneously adding a monomer or a mixture of ethylenic monomers and a suspension polymerization stabilizer, followed by suspension polymerization. This is an impact-resistant resin composition obtained by blending a graft polymer (A) with a rubber content of 70% by weight or less and a thermoplastic resin (B). In the present invention, the rubber content in the graft polymer (A) is preferably 35 to 70% by weight. If the rubber content is less than 35%, it is difficult to simultaneously satisfy the three requirements of impact resistance, gloss, and thermoforming stability of the composition obtained by blending with the thermoplastic resin (B).
If it exceeds 70%, the rubber particles become unstable and tend to aggregate, resulting in a marked decrease in the smoothness of the extruded sheet or film surface. Rubbery polymers used in producing the graft polymer (A) include diene rubbers such as butadiene rubber, styrene-butadiene rubber, acrylonitrile butadiene rubber, isoprene rubber, and chloroprene rubber, methyl acrylate, and ethyl acrylate. , acrylic rubber containing butyl acrylate as a main component, ethylene-vinyl acetate copolymer, etc., and in some cases, a small amount of copolymerizable monomer may be copolymerized. Monomers that can be copolymerized with such rubber include aromatic monomers such as styrene, α-methylstyrene, and P-substituted styrene, as well as acrylonitrile,
Acrylic ester, methacrylic ester, methacrylonitrile, lower alkyl acrylate,
Examples include lower alkoxy acrylate, cyanoethyl acrylate, acrylamide, acrylic acid, and methacrylic acid. The rubber elastomer may be crosslinked or uncrosslinked, but in the case of uncrosslinked rubber, it is preferable to use an appropriate amount of crosslinking agent due to problems such as moldability. When using a diene rubber as the rubber elastomer, the ethylenic monomer to be graft copolymerized is an aromatic monomer such as styrene, α-methylstyrene, or a P-substituted styrene derivative, and an ethylenic monomer that can be copolymerized. Acrylic acid derivatives such as methyl methacrylate, ethyl methacrylate, and lower acrylic esters are preferably used as monomers for graft copolymerization when using acrylic rubber. suitable. As the emulsifier used in the emulsifying part polymerization, known anionic emulsifiers such as sodium alkylbenzene sulfonate can be used, and as the polymerization initiator,
Peroxides such as cumene hydroperoxide and persulfates such as ammonium persulfate, as well as redox systems consisting of t-butyl hydroperoxide-reducing agent systems, may also be used. In emulsion polymerization, no chain transfer agent is used at all, and although it is possible to use only a combination of an ethylenic monomer or a mixture thereof and a polymerization initiator, it is preferable to add a chain transfer agent. Chain transfer agents that can be used include alkyl mercaptans, alkyl halides, alkyl sulfides, alkyl disulfides, thioglycolic acid esters,
Alkyl mercaptans are particularly preferred, although α-methylstyrene dimers are also used. Partial flocculants used after emulsion polymerization include:
Any acid or water-soluble inorganic salt can be used, and the dissociation constant of mineral acids such as sulfuric acid and hydrochloric acid, acetic acid etc.
10 ^-6 mol/or more of organic acids (including benzoic acid, salicylic acid, formic acid, and tartaric acid). Salts include, but are not limited to, sulfates such as magnesium sulfate and sodium sulfate, chlorides, and acetates. As the suspension polymerization stabilizer, ordinary innumerable dispersants and organic dispersants can be used. Examples of the innumerable dispersant include magnesium carbonate and tribasic calcium phosphate. Among organic dispersants, natural and synthetic polymer dispersants include starch, gelatin, acrylamide, partially saponified polyvinyl alcohol, partially saponified polymethyl methacrylate, polyacrylic acid and its salts, cellulose, methylcellulose, Examples include hydroxymethylcellulose, hydroxyethylcellulose, polyvinylpyrrolidone, polyvinylimidasol, and sulfonated polystyrene. Also, common emulsifiers such as alkylbenzene sulfonates and fatty acid salts can also be used as low-molecular dispersants. . In the suspension polymerization, peroxides such as benzoyl peroxide and lauroyl peroxide, and azo compounds such as azobisisobutyronitrile are used as initiators. Even in suspension polymerization, a combination of only an ethylenic monomer or a mixture thereof and a polymerization initiator may be used, but it is preferable to add a chain transfer agent. As the chain transfer agent, the same ones used in emulsion polymerization can be used. The polymerization initiator and chain transfer agent can be added by dissolving them in the ethylenic monomer, or by partially coagulating the polymerization initiator and chain transfer agent separately before adding the ethylenic monomer. Any method may be used, such as adding it into the graft polymer latex or adding the polymerization initiator and chain transfer agent after adding the ethylenic monomer. It is also possible to add plasticizers, lubricants, stabilizers, ultraviolet absorbers, etc. that can be dissolved in the monomer mixture during suspension polymerization and do not hinder the progress of polymerization. The thermoplastic resin (B) used in the present invention is preferably a copolymer of acrylonitrile and styrene, but other examples include vinyl polymers such as polymethyl methacrylate, polyvinyl chloride, polystyrene, and polypropylene, polycarbonate, thermoplastic polyester, and polyamide. etc. can also be used. The resin composition of the present invention can be obtained by mechanically mixing the graft polymer (A) and the thermoplastic resin (B) using a commonly used Henschel mixer, Banbury mixer, extruder, roll mill, etc. . It is also possible to add stabilizers, plasticizers, lubricants, ultraviolet absorbers, pigments, dyes, etc. during the mixing. In the following examples, parts represent parts by weight. Example 1 Polybutadiene latex (solid content)*
90 parts (45 parts) Styrene 25.9 parts Acrylonitrile 9.1 parts Ferrous sulfate 0.004 parts Dextrose 0.7 parts Kyumene hydroperoxide 0.44 parts Tertiary dodecyl mercaptan 0.40 parts Sodium pyrophosphate 0.27 parts Disproportionated rosin acid soap 3.3 parts Caustic soda 0.13 Part Methylene bisnaphthalene sulfonate sodium
0.27 parts Deionized water 155 parts (*Sumitomo Nogatatsuku SN-800B Solid content
50%) A mixture with the above composition was charged into a reactor, and after purging the inside of the reactor with nitrogen, the mixture was heated at 70°C with a stirring speed of 200 rpm.
The reaction was completed by polymerizing for 3 hours to obtain a graft polymer latex. The polymerization conversion rate was 85%. Obtained graft polymer latex (PH11.0)
was brought to room temperature, and 11 parts of a 10% sulfuric acid aqueous solution was added under stirring at 350 rpm to dissolve the high viscosity partial aggregates (PH
3.0), then 14.8 parts of styrene, 5.2 parts of acrylonitrile, and 0.1 parts of benzoyl peroxide.
Upon addition of a mixture of 1 part and 1 part of tertiary dodecyl mercaptan, the dispersion went from a high viscosity state to a low viscosity state (10 centipoise). Add 10% of polyvinyl alcohol, a suspension stabilizer, to this dispersion.
Add 20 parts of aqueous solution (degree of saponification 80%) and heat at 80℃ for 5 minutes.
Polymerization was carried out by heating for a period of time. After the polymer was filtered off, it was washed, dehydrated, and dried using a basket-type centrifugal dehydrator. The polymerization conversion rate was 98%, and the obtained polymers are shown in Table 1.
They were beautiful beads with a particle size distribution like this. 34 parts dry particles, acrylonitrile-styrene copolymer (acrylonitrile content 27%, η
66 parts of sp/C (25° C. DMF)=0.60) and 0.4 parts of calcium stearate were mixed in a 10 volume Henschel mixer at 3000 rpm, pelletized, and a test piece was molded using an injection molding machine. The molded product had no tropical color and had extremely excellent surface gloss. Example 2 A graft polymer latex (PH11.0) obtained in the same manner as in Example 1 was returned to room temperature, and 11 parts of a 10% sulfuric acid aqueous solution was added thereto under stirring at 350 rpm to form a highly viscous partial aggregate ( 10% aqueous solution of suspension stabilizer polyvinyl alcohol (degree of saponification 80%)
20 parts and 14.8 parts of styrene, 5.2 parts of acrylonitrile
When a mixture of 0.1 part benzoyl peroxide, 0.1 part benzoyl peroxide, and 1 part tertiary dodecyl mercaptan was simultaneously added, the dispersion changed from a high viscosity state to a low viscosity state (10 centipoise). This dispersion was heated to 80℃ for 5 minutes.
Polymerization was carried out by heating for a period of time. After the polymer was filtered off, it was washed, dehydrated, and dried using a basket-type centrifugal dehydrator. The polymerization conversion rate was 98%, and the obtained polymers are shown in Table 1.
They were beautiful beads with a particle size distribution like this. 34 parts dry particles, acrylonitrile-styrene copolymer (acrylonitrile content 27%, η
sp/c (25°C DMF) = 0.61) and 0.4 part of calcium stearate were mixed in a 10 volume Henschel mixer at 3000 rpm, pelletized, and a test piece was molded using an injection molding machine. The molded product had no tropical color and had extremely excellent surface gloss. Example 3 Polybutadiene latex (solid content)*
140 parts (70 parts) Styrene 7.4 parts Acrylonitrile 2.6 parts Ferrous sulfate 0.003 parts Dextrose 0.66 parts Kyumene hydroperoxide 0.43 parts Tertiary dodecyl mercaptan 0.40 parts Sodium pyrophosphate 0.26 parts Disproportionated rosin acid soap 3.34 parts Caustic soda 0.14 Part Methylene bisnaphthalene sulfonate sodium
0.26 parts deionized water 210 parts (*Sumitomo Nogatatsuku SN-800B Solid content
50%) A mixture with the above composition was charged into a reactor, and after purging the inside of the reactor with nitrogen, the mixture was heated at 70°C with a stirring speed of 200 rpm.
The reaction was completed by polymerizing for 3 hours to obtain a graft polymer latex. The polymerization conversion rate was 85%. Obtained graft polymer latex (PH11.0)
Return to room temperature, add 18 parts of 10% sulfuric acid aqueous solution under stirring at 350 rpm to obtain high viscosity partial aggregates (PH3.0)
When a mixture of 14.8 parts of styrene, 5.2 parts of acrylonitrile, 0.1 part of benzoyl peroxide, and 1 part of tertiarydodecyl mercaptan was added, the dispersion changed from a high viscosity state to a low viscosity state (10 centipoise). This dispersion was added with a suspension stabilizer, a polyvinyl alcohol aqueous solution (10
%, degree of saponification 80%) was added and polymerized at 80°C for 5 hours. After the polymer was filtered off, it was washed, dehydrated, and dried using a basket-type centrifugal dehydrator. The polymerization conversion rate was 97%, and the obtained polymer was a beautiful bead body with a particle size distribution as shown in Table 1. 21 parts dry particles, acrylonitrile-styrene copolymer (acrylonitrile content 27%, η
79 parts of sp/C (25° C. DMF) = 0.61) and 0.4 parts of calcium stearate were mixed in a 10 volume Henschel mixer at 3000 rpm, pelletized, and a test piece was molded using an injection molding machine. The molded product had no tropical color and had extremely excellent surface gloss. Comparative Example 1 Using a graft polymer latex obtained in the same manner as in Example 1, after adding a suspension stabilizer,
First, a styrene-acrylonitrile monomer mixture was subjected to suspension polymerization in the same manner as in Example 1, except that 8 parts of a 10% aqueous sulfuric acid solution was added thereto for suspension polymerization. The obtained polymer had a particle size distribution as shown in Table 1, and the same acrylonitrile as in Example 1 was used.
Styrene copolymer (AS) and the like were mixed, and the molded product obtained from the mixture was slightly colored. Comparative Example 2 A graft polymer latex obtained in the same manner as in Example 1 was used, and a monomer mixture, a flocculant, and a suspension stabilizer were added in this order. Although it formed into lumps during heating, it was crushed and mixed with the same material as used in Example 1.
A test piece was created by mixing it with AS. Comparative Example 3 A graft polymer latex obtained in the same manner as in Example 1 was used, and a monomer mixture, a suspension stabilizer, and a flocculant were added in this order. Since quite coarse particles were generated, they were crushed and a test piece was prepared in the same manner as in Comparative Example 2. Comparative example 4 Polybutadiene latex (solid content)*
160 parts (80 parts) Styrene 7.9 parts Acrylonitrile 2.8 parts Ferrous sulfate 0.005 parts Dextrose 0.92 parts Kyumene hydroperoxide 0.61 parts Tertiary dodecyl mercaptan 0.54 parts Sodium pyrophosphate 0.36 parts Disproportionated rosin acid soap 4.5 parts Caustic soda 0.18 Part Methylene bisnaphthalene sulfonate sodium
0.36 parts deionized water 200 parts (*Sumitomo Nogatatsuku SN-800B solid content
50%) A mixture with the above composition was charged into a reactor, and after purging the inside of the reactor with nitrogen, the mixture was heated at 70°C with a stirring speed of 200 rpm.
The reaction was completed by polymerizing for 3 hours to obtain a graft polymer latex. The polymerization conversion rate was 80%. Obtained graft polymer latex (PH11.0)
Return to room temperature, add 20.5 parts of 10% sulfuric acid aqueous solution under stirring at 350 rpm, then add 7.9 parts of styrene, 2.8 parts of acrylonitrile, and benzoyl peroxide.
Upon addition of a mixture of 0.05 parts and 0.50 parts of tertiary dodecyl mercaptan, the dispersion changed from a high viscosity state to a low viscosity state (15 centipoise). 20 parts of a polyvinyl alcohol aqueous solution (10%, degree of saponification 8.0%) as a suspension stabilizer was added to this dispersion,
Polymerization was carried out at 80°C for 5 hours. After filtering out the polymer,
It was washed, dehydrated and dried using a basket type centrifugal dehydrator. The polymerization conversion rate was 95%, and the obtained polymer was a beautiful bead body with a particle size distribution as shown in Table 1. 19 parts of dried particles, similar to those used in Example 2.
81 parts AS and 0.4 parts calcium stearate
After mixing in a 10 volume Henschel mixer at 3000 rpm, the mixture was pelletized and molded into test pieces using an injection molding machine. The surface of the extruded product was extremely lacking in smoothness and had low impact resistance. Comparative example 5 Polybutadiene latex (solid content)*
90 parts (45 parts) Styrene 40.7 parts Acrylonitrile 14.3 parts Ferrous sulfate 0.005 parts Dextrose 0.97 parts Kyumene hydroperoxide 0.63 parts Tertiary dodecyl mercaptan 0.58 parts Sodium pyrophosphate 0.38 parts Disproportionated rosin acid soap 4.86 parts Caustic soda 0.20 Part Methylene bisnaphthalene sulfonate sodium
0.38 parts Deionized water 305 parts (*Sumitomo Nogatatsuku Nipole 1202 solid content 50
%) The mixture of the above composition was charged into a reactor, and after purging the inside of the reactor with nitrogen, the mixture was heated to 70°C with a stirring speed of 200 rpm.
The reaction was completed by polymerizing for 3 hours to obtain a graft polymer latex. The polymerization conversion rate was 96%. Obtained graft polymer latex (PH11.0)
was coagulated by adding 25 parts of concentrated sulfuric acid under stirring at 600 rpm, washed with deionized water, dehydrated using a basket-type centrifugal dehydrator, and dried. The obtained polymer was a powder having a particle size distribution as shown in Table 1. 34 parts dry powder, same as used in Example 1
66 parts AS and 0.4 parts calcium stearate
After mixing in a 10 volume Henschel mixer at 3000 rpm, the mixture was pelletized and molded into test pieces using an injection molding machine. The molded product was colored and its gloss was not good. The various resin properties of the above examples and comparative examples are summarized in Table 2.

【table】

[Table] Example 4 Butyl acrylate 66.5 parts 1,3-butylene dimethacrylate 3.5 parts Allyl methacrylate 0.88 parts Sodium formaldehyde sulfonate
0.18 parts Ferrous sulfate 0.0009 parts Ethylenediaminetetraacetic acid disodium salt
0.0026 parts Kyumene hydroperoxide 0.18 parts Nonsal TK-I (manufactured by NOF Corporation) 3.5 parts Deionized water 245 parts The mixture with the above composition was charged into a reactor, the inside of the reactor was replaced with nitrogen, and the stirring speed was 70 rpm at a stirring speed of 200 rpm. ℃2
Polymerization was carried out for a period of time to complete the reaction and an acrylic rubber latex was obtained. Add the following ingredients dropwise to this acrylic rubber latex for 30 minutes or more while stirring.
Graft emulsion polymerization was carried out for a period of time. Methyl methacrylate 10 parts Allyl methacrylate 0.2 parts Kyumene hydroperoxide 0.03 parts Tertiarydodecyl mercaptan 0.02 parts The polymerization conversion rate was 98%, and the final particle size was 0.10 μm (as measured by an electron microscope). The polymer latex was brought to room temperature, 250 parts of deionized water was added, and the mixture was stirred at 350 rpm for 10 min.
% sulfuric acid was added to cause partial coagulation. Next, a mixed solution of 20 parts of methyl methacrylate, 0.10 parts of lauroyl peroxide, and 1.3 parts of tertiarydodecyl mercaptan was added to form a stable dispersion. After this, 3.3 parts of a 3% sodium polyacrylic acid salt aqueous solution was added, and the mixture was heated at 80°C for 2 hours and then at 90°C for 2 hours.
Polymerization was carried out for a period of time to obtain a beautiful bead-like polymer. 57 parts dry particles, polymethyl methacrylate
43 parts and 0.5 parts of calcium stearate
After mixing in a 10 volume Henschel mixer at 3000 rpm, it was pelletized and molded into a test piece using an injection molding machine (cylinder temperature 240℃, injection pressure 65℃).
Kg/cm ² , mold temperature 60℃) In-situ impact strength 35Kg・cm/cm ² , transparency (92% total transparency, haze 1.0)
%) was obtained. Furthermore, the molded product was not colored by heating and maintained excellent transparency.

Claims (1)

[Claims] 1. Adding an acidic substance or an electrolyte substance to a graft polymer latex obtained by emulsion polymerizing an ethylenic monomer or an ethylenic monomer mixture to a rubber-like polymer to cause partial coagulation, Then, an ethylenic monomer or a mixture of ethylenic monomers and a suspension polymerization stabilizer are added sequentially or simultaneously, followed by suspension polymerization, resulting in a rubber content of 70.
Less than % by weight of graft polymer (A) and thermoplastic resin (B)
An impact-resistant resin composition with excellent gloss and thermoforming stability obtained by blending the above. 2. The impact-resistant resin composition according to claim 1, wherein the rubbery polymer is a diene rubber. 3. The impact-resistant resin composition according to claim 1, wherein the rubbery polymer is an acrylic rubber. 4. The impact-resistant resin composition according to claim 1, 2, or 3, wherein the thermoplastic resin (B) is a copolymer of styrene and acrylonitrile.