JPS6245899B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic resin composition, and particularly to a resin composition that has excellent mechanical strength and moldability, and provides molded articles with low surface gloss. Acrylonitrile-butadiene-styrene copolymer resin (hereinafter referred to as ABS resin) has traditionally been used for various purposes because it has excellent properties such as mechanical strength, moldability, and chemical resistance, and its molded products have a rich surface gloss. However, for example, for cameras, suitcases, etc., there is a demand for a so-called matte surface with less gloss. Generally, methods for matting thermoplastic resins include mixing inorganic fillers, such as oxides of titanium, magnesium, and calcium, or their carbonates, with thermoplastic resins, or adding diene-based rubber-like materials to thermoplastic polymer latex. A method of mixing polymer latex has been proposed, but the former does not produce the desired matte state and the molded product has poor impact strength, while the latter has lower impact strength than the base thermoplastic resin. The disadvantage was that there was a large decrease in rigidity, although it was small. The present invention aims to solve these drawbacks, and is a thermoplastic resin obtained by mixing ABS resin latex and a specific unsaturated carboxylic acid ester latex in a latex state, and then precipitating the mixture as a homogeneous mixture. The object of the present invention is to provide a thermoplastic resin composition in which the surface gloss of the ABS resin is reduced without deteriorating the various properties of the ABS resin. The present invention comprises an emulsion graft copolymer latex obtained by polymerizing an aromatic vinyl monomer and an acrylic monomer in the presence of component (A), namely a diene-based rubbery polymer latex, and component (B), namely A product obtained by precipitating the resin solid content after mixing a specific proportion with an unsaturated carboxylic acid ester polymer latex having a specific gel content, glass transition temperature, and latex particle size, and has various characteristics of conventional ABS resin. It is also a thermoplastic resin composition with reduced surface gloss of the molded product, and is used for applications that require the formation of a matte surface, such as cameras, suitcase housings, automobile interior parts, household appliance parts, and other miscellaneous goods. It is useful for Component (A) used in the present invention is a graft copolymer obtained by emulsion polymerization of one or more aromatic vinyl monomers and one or more acrylic monomers in the presence of a diene rubber-like polymer latex. Diene-based rubber-like polymer latex refers to polymerized diene monomers such as butadiene, isoprene, dimethylbutadiene, chloroprene, etc., or monomers copolymerizable with the diene monomers. For example, it is a latex obtained by emulsion copolymerization of one or more monomers selected from styrene, α-methylstyrene, acrylonitrile, acrylic ester, methacrylic ester, etc. The aromatic vinyl monomers to be emulsion graft polymerized in the presence of the diene rubbery polymer latex include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butyl Styrene, monochlorostyrene, dichlorostyrene, etc. Similarly, the acrylic monomers to be subjected to emulsion graft polymerization include acrylonitrile, methacrylonitrile, acrylic esters, methacrylic esters, and the like. These monomers may be used alone or as a mixture thereof. Various known methods can be used to emulsion graft copolymerize these monomers, and there are no particular restrictions. Next, component (B) will be explained. Component (B) consists of a latex obtained by emulsion polymerization of a mixture of one or more monomers selected from unsaturated carboxylic acid ester monomers or vinyl monomers copolymerizable with these monomers. Carboxylic acid ester monomers include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, cyclohexyl acrylate,
2-ethylhexyl acrylate, 2-ethylhexyl acrylate
Hydroxyethyl, 2-hydroxypropyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2-dimethylaminoethyl acrylate, 2-diethylaminoethyl acrylate, glycidyl acrylate, etc. and monomers having a cyano group, methyl group, halogen, etc. substituted at the alpha position of these monomers, and one or more selected from these monomers. In addition, vinyl monomers that can be copolymerized with these unsaturated carboxylic acid ester monomers include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, monochloro styrene,
Aromatic vinyl monomers such as dichlorostyrene, vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, olefin monomers such as ethylene, propylene, 1-butene, isobutylene, and 2-butene, vinyl acetate, propionic acid These include aliphatic vinyl ester monomers such as vinyl, halogenated olefin monomers such as vinyl chloride and vinylidene chloride, and vinyl ether monomers such as methyl vinyl ether, ethyl vinyl ether, and phenyl vinyl ether. It is one or more of the following. To give an example of a particularly preferable combination (meta)
Acrylic ester-vinyl acetate-ethylene,
Examples include (meth)acrylic ester-vinyl acetate-vinyl ether, (meth)acrylic ester-vinyl acetate, and (meth)acrylic ester-styrene. If necessary, polyfunctional vinyl monomers can be used in combination with the above combinations. Addition of a polyfunctional vinyl monomer promotes gelation of the polymer, and an increase in gel-like substances in component (B) reduces the surface gloss of the molded product of the present invention. Examples of polyfunctional vinyl monomers include ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, propylene glycol dimethacrylate, triallyl cyanurate, triallyl isocyanurate, trimethylolpropane trimethacrylate, Examples include divinylbenzene. The monomers described above are polymerized by a known emulsion polymerization method to obtain a latex. What is particularly important in the present invention is that component (B) has a glass transition temperature of -60 to 5°C, preferably -40 to The temperature range is 0°C. The reason for this is that resins with a glass transition temperature of -60°C or lower that are precipitated by mixing them with component (A) latex have a significant decrease in rigidity.
In addition, if the temperature exceeds 5℃, the impact strength will decrease significantly.
This is because it is not desirable. In addition, the volume average particle diameter of the particles of component (B) is
A material having a diameter of 0.2μ or more, preferably 0.5μ or more is used. The reason is that (A) those below 0.2μ
This is because even if the resin is precipitated by mixing latex with the components, not only the surface gloss of the molded product is not sufficiently reduced, but also the impact strength is significantly reduced. In addition, component (B) must contain gel in an amount of 50% by weight or more, preferably 70% by weight or more, in the polymer solid, ie, the dry polymer recovered from the latex. However, the gel content referred to here is determined by the following method. That is, 1 g of polymer
Add to 100 g of methyl ethyl ketone and stir vigorously for 6 hours at room temperature. This one at 15000rpm
Centrifuge for 1 hour and determine the dry weight of the precipitate. The obtained dry weight is multiplied by 100 to obtain the gel content (% by weight). There are no particular limitations on the method by which the polymer solid can be provided with a gel content within the range specified in the present invention. Usually, the purpose is achieved by adding a small amount of polyfunctional vinyl monomer during polymerization. However, the addition of polyfunctional vinyl monomers is not always necessary, and it is necessary to select the type of polymerization initiator, the composition of the monomers constituting component (B), the type of surfactant, etc. It is also possible to achieve the gel content within the range specified in the present invention by controlling other polymerization factors and their combinations. If the gel content in component (B) is less than the range specified in the present invention, the surface gloss of the molded product may deteriorate even if the resin is precipitated by mixing components (B) and (A) in latex. The decline is not enough. Next, components (A) and (B) are mixed in a latex state to precipitate resin solids. As the precipitating agent, for example, hydrochloric acid, sulfuric acid, acetic acid, sodium chloride, potassium chloride, calcium chloride, magnesium chloride, aluminum chloride, sodium sulfate, potassium sulfate, magnesium sulfate, aluminum sulfate, etc. can be used alone or in combination as an aqueous solution. . The latex to which the precipitating agent has been added is heated and stirred to precipitate it, and is then subjected to dehydration, water washing, and drying steps to form a resin composition. The reason why components (A) and (B) are mixed in the latex in this way in the present invention is that when the latex is precipitated separately and then mixed using a known mechanical mixing means, it has a lower mechanical strength. As the surface gloss of the molded product decreases, the surface gloss of the molded product becomes non-uniform, and a practically preferable reproducibility cannot be obtained, making it impossible to obtain the desired molded product. In the present invention, a copolymer consisting of an acrylic monomer and an aromatic vinyl monomer can be further blended into the above polymer mixture. The acrylic monomers mentioned here include acrylonitrile, methacrylonitrile, acrylic esters, methacrylic esters, etc., and the aromatic vinyl monomers include styrene, α-methylstyrene, o-methylstyrene, m- Methylstyrene, p-methylstyrene, t-butylstyrene, monochlorostyrene,
Dichlorostyrene, etc. (A) ABS as component
When a resin is used, an acrylonitrile-styrene copolymer is preferably used as the above copolymer. When the above copolymer is blended into a polymer mixture consisting of components (A) and (B), the resin solid content in component (B) is 2 to 30% by weight, preferably 2% by weight of the total resin solids. ~20% by weight. If a copolymer consisting of an acrylic monomer and an aromatic vinyl monomer is not blended, (A)
When mixing the components and (B) in the latex state, the mixing ratio of component (B) is resin solids, that is, 2 to 30% by weight of the total resin solids in dry weight%, preferably 2 to 20% by weight of the total resin solids. % by weight.
If component (B) is less than 2% by weight of the total resin solids in the resin composition, the surface gloss of the molded product will not be reduced sufficiently, and if it exceeds 30% by weight, the rigidity of the molded product will decrease, which is undesirable. . In addition, plasticizers, stabilizers, lubricants, antistatic agents,
Known additives such as colorants can be blended. The present invention will be further explained with reference to Examples below, and all parts and percentages mentioned in the specification are expressed on a weight basis. Example 1 (A) Production of Components 133 parts of polybutadiene latex (solid content 30%, volume average particle diameter 0.3μ) was charged into an autoclave, followed by 120 parts of pure water, 1 part of sodium dodecylbenzenesulfonate, and ferrous sulfate. 0.002 part of tetrasodium styrenediaminetetraacetate, and 0.12 part of sodium aldehyde sulfoxylate were added, and the mixture was stirred under a nitrogen atmosphere. Keep the contents at 60℃, add 45 parts of styrene, 15 parts of acrylonitrile,
A monomer mixture consisting of 0.6 parts of t-dodecyl mercaptan and 0.2 parts of benzoyl peroxide was continuously added to the above latex over a period of 6 hours. After the addition of the monomer mixture was completed, the mixture was further stirred at 70°C for 2 hours to complete polymerization, thereby obtaining an ABS resin latex. (B) Production of ingredients In a pressure autoclave, add 2.7 parts of partially saponified polyvinyl alcohol, 0.1 part of sodium acetate, 0.003 parts of ferrous sulfate, 0.006 parts of tetrasodium ethylenediaminetetraacetate, and 0.18 parts of sodium aldehyde sulfoxylate to 80 parts of pure water. The dissolved aqueous solution was added, and then 25 parts of vinyl acetate was added while stirring to emulsify. After creating a nitrogen atmosphere inside the autoclave, 15 parts of ethylene was pressurized. After heating the contents to 50°C, which is the polymerization temperature, a mixed monomer prepared by dissolving 10 parts of ethylene glycol dimethacrylate in 60 parts of butyl acrylate, and ammonium persulfate were added.
20 parts of 0.1% aqueous solution were added separately and continuously over 8 hours each time. After the addition was completed, the mixture was further stirred at 70°C for 5 hours to complete the polymerization. The volume average particle diameter of the obtained latex particles was 0.8 μ, the glass transition temperature of the acrylic polymer recovered from the latex was -32° C., and the gel content was 91%. Manufacture of composite ABS resin After mixing and stirring the latexes of component (A) and component (B) in the ratio (weight) shown in Table 1 as a solid content in the latex state, 30 parts of a 10% calcium chloride aqueous solution was added, and the temperature was increased. The mixture was stirred at 100° C. for 5 minutes to obtain a polymer mixture in a slurry state, which was further dehydrated, washed with water, and dried to obtain a polymer mixture. Next, a commercially available acrylonitrile-styrene suspension polymer (acrylonitrile content 25%,
A 1% solution of methyl ethyl ketone (relative viscosity ηrel 1.52) at a temperature of 30°C, 0.3 parts of 2,6-di-t-butyl-4-methylphenol, and 0.2 parts of triphenyl phosphorite were mixed and melted using an extruder. It was made into pellets. A test piece was prepared from this pellet and its physical properties were measured. The results are shown in Table 1. Incidentally, the measured values of the Examples and Comparative Examples described below were all determined by the following method. (1) Tensile strength (yield point) ……ASTM D-638 (2) Izot impact strength ……ASTM D-256 (3) Melt flow index
...ASTM D-1238 (4) Gloss ...ASTM D-523 (5) Flexural modulus ...ASTM D-790 Molding was performed at a molding temperature of 230°C, a mold temperature of 40°C, and an incident angle of 60°. It was measured with Example 2 In a pressure autoclave, 1 part of partially saponified polyvinyl alcohol, 2.5 parts of sodium dodecylbenzenesulfonate, 0.003 parts of ferrous sulfate, 0.006 parts of tetrasodium ethylenediaminetetraacetate, and 0.18 parts of sodium aldehyde sulfoxylate were added to 80 parts of pure water. The dissolved aqueous solution was added and stirred under nitrogen atmosphere. After the contents were maintained at the polymerization temperature of 50°C, a monomer mixture consisting of 83 parts of butyl acrylate, 17 parts of styrene, 0.5 parts of triallyl cyanurate, and 0.2 parts of benzoyl peroxide was continuously added over 12 hours. After addition, add 0.1 part of benzoyl peroxide to 4 parts of styrene.
The polymerization was completed by adding a solution dissolved in 50% of the solution and stirring the mixture at a temperature of 70° C. for 2 hours. The volume average particle diameter of the obtained latex particles is 0.1
μ, the glass transition temperature of the acrylic polymer recovered from the latex is -5℃, and the gel content is 95
It was %. This latex was enlarged using a pressurized enlargement device to obtain an enlarged latex with a volume average particle diameter of 0.5μ. The acrylic polymer latex obtained here and the component (A) described in Example 1.
After mixing ABS resin latex in the latex state at the ratio shown in Table 2 and stirring thoroughly,
Add 30 parts of 10% calcium chloride aqueous solution and heat at 100°C.
A polymer mixture in a slurry state was obtained by stirring for 5 minutes. This was treated in the same manner as in Example 1 and tested for physical properties, and the results are shown in Table 2. Example 3 Acrylic acid 2- in place of 60 parts of butyl acrylate
A latex of component (B) was obtained in the same manner as in Example 1 except that 60 parts of methoxyethyl was used. The volume average particle diameter of the obtained latex particles was 1 .mu., the glass transition temperature of the acrylic polymer recovered from this latex was -40 DEG C., and the gel content was 95%. This component (B) was treated in the same manner as in Example 1 to obtain a test piece, which was then subjected to physical property tests. The results are shown in Table 3. Example 4 67 parts of polybutadiene latex (solid content 30%, volume average particle diameter 0.45μ) was charged into an autoclave, followed by 186 parts of pure water, 3 parts of sodium dodecylbenzenesulfonate, 0.002 parts of ferrous sulfate, and ethylenediaminetetraacetic acid. 0.004 parts of tetrasodium, 0.12 parts of sodium aldehyde sulfoxylate, 4.8 parts of acrylonitrile, 11.2 parts of styrene, and 0.096 parts of benzoyl peroxide were added, and the mixture was stirred under a nitrogen atmosphere. After raising the temperature of the contents to 50°C and holding it for 2 hours, 19.2 parts of acrylonitrile and 44.8 parts of styrene were added.
A monomer mixture consisting of 1 part, 0.384 part of t-dodecyl mercaptan, and 0.12 part of benzoyl peroxide was continuously added over 7 hours. After the addition was completed, the mixture was further stirred at 70°C for 2 hours to complete the polymerization.
ABS resin latex was obtained. obtained here
ABS resin latex and (B) described in Example 1
The components latex and latex were mixed in the latex state in the proportions listed in Table 4, and after thorough stirring, 30 parts of a 10% calcium chloride aqueous solution was added, and the mixture was heated at 100°C for 50 minutes.
A polymer mixture in a slurry state was obtained by stirring for a minute, and this was further dehydrated, washed with water, and dried to obtain a polymer mixture. Then this polymer mixture 100
0.3 part of 2,6-di-t-butyl-4-methylphenol and 0.2 part of triphenyl phosphite were mixed into the mixture, and this was melted into pellets using an extruder. A test piece was prepared from this pellet in the same manner as in Example 1, and its physical properties were measured. The results are shown in Table 4.

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[Table] Comparative Example 1 In a pressure autoclave, 2.7 parts of partially saponified polyvinyl alcohol, 0.1 part of sodium acetate, 0.003 parts of ferrous sulfate, 0.006 parts of tetrasodium ethylenediaminetetraacetate, and 0.18 parts of sodium aldehyde sulfoxylate were added to 80 parts of pure water. Add the dissolved aqueous solution, then add 40 parts of vinyl acetate, 0.5 parts of triallyl cyanurate and 10 parts of ethyl acrylate while stirring.
1 part was added and emulsified. After creating a nitrogen atmosphere inside the autoclave, 10 parts of ethylene was introduced under pressure. After heating the contents to 50℃, which is the polymerization temperature, 40 parts of vinyl acetate and a 0.1% aqueous solution of ammonium persulfate were added.
20 parts were added sequentially over 10 hours each time. After the addition was completed, the mixture was further stirred at 70°C for 5 hours to complete the polymerization. The volume average particle diameter of the obtained latex particles was 1 μ, the glass transition temperature of the acrylic polymer recovered from the latex was 17° C., and the gel content was 88%. The resin solid content of the acrylic polymer latex obtained here is 20
part and 80 parts as the resin solid content of the ABS resin latex obtained as component (A) in Example 1 were mixed in a latex state, and after stirring thoroughly, Example 1
A precipitation treatment was performed in the same manner as in , and the resin was recovered. 100 parts of the obtained polymer mixture was treated with AS in the same manner as in Example 1.
A test piece was prepared by mixing 100 parts of resin beads, and a physical property test was conducted. The results are shown in Table 5. Comparative Example 2 As the resin solid content of component (B) obtained in Example 2
20 parts were obtained in Example 1 without being subjected to pressure enlargement treatment.
The latex was mixed with 80 parts of resin solid content of component (A) ABS resin latex, treated in the manner shown in Example 1, and tested for physical properties. The results are shown in Table 5. Comparative Example 3 Polymerization was carried out in the same manner as in Example 2 except that triallyl cyanurate was not added to obtain a latex of component (B). The volume average particle diameter of the obtained latex particles was 0.06μ, the glass transition temperature of the acrylic polymer recovered from the latex was -5°C, and the gel content was 0%. This latex was subjected to an enlargement treatment to obtain an enlarged latex having a volume average particle diameter of 0.5μ. This material was treated in the same manner as Comparative Example 1,
Physical property tests were conducted. The results are shown in Table 5. Comparative Example 4 30 parts of a 10% calcium chloride aqueous solution was added to 100 parts of component (A) obtained in Example 1 (as resin solid content), stirred at 100°C for 5 minutes, and the resulting slurry was dehydrated. The ABS resin was recovered by washing with water and drying.
Furthermore, the component (B) obtained in Example 2 was freeze-precipitated at -30°C, and then dehydrated, washed with water, and dried to recover an acrylic polymer. obtained in this way
Mix 80 parts of ABS resin and 20 parts of acrylic polymer with 100 parts of AS resin beads in the same manner as in Example 1,
After treatment, physical property tests were conducted. The results are shown in Table 5. The composite ABS resin obtained in this comparative example not only had poor impact strength, but also the surface condition of the molded product was non-uniform. Comparative Example 5 Polybutadiene latex (volume average particle diameter
0.3μ) (as resin solid content) and 80 parts (as resin solid content) of the (A) component latex obtained in Example 1 were mixed in a latex state, and Example 1
The material was treated in the same manner as above and physical property tests were conducted. The results are shown in Table 5. Comparative Example 6 100 parts of the ABS resin recovered from the latex in Comparative Example 4, 120 parts of AS resin beads, and 2,6-G-t
A mixture of 0.3 part of -butyl-4-methylphenol and 0.2 part of triphenyl phosphite was melt-kneaded in an extruder to obtain a pellet-shaped resin.
This was molded into a predetermined test piece, and a physical property test was conducted. The results are shown in Table 5.

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Claims (1)

[Scope of Claims] 1. (A) A graft copolymer latex obtained by copolymerizing a diene-based rubbery polymer latex with an aromatic vinyl monomer and an acrylic monomer; and (B) one or more types of Obtained by emulsion polymerization of an unsaturated carboxylic acid ester monomer or a mixture of one or more unsaturated carboxylic acid ester monomers and a vinyl monomer copolymerizable therewith, and has a glass transition temperature of 5 to - 60℃, average particle size 0.2μ or more,
A thermoplastic resin composition obtained by mixing in a latex state a latex having a gel content of 50% by weight or more in a polymer solid, and precipitating a resin solid content. 2. The thermoplastic according to claim 1, wherein the resin solid content in component (B) is 2 to 30% by weight of the sum of the resin solid content in component (A) and the resin solid content in component (B). Resin composition. 3 (A) A graft copolymer latex obtained by copolymerizing a diene-based rubbery polymer latex with an aromatic vinyl monomer and an acrylic monomer; and (B) one or more unsaturated carboxylic acid ester monomers. It is obtained by emulsion polymerization of a mixture consisting of a monomer or one or more unsaturated carboxylic acid ester monomers and a vinyl monomer copolymerizable therewith, and has a glass transition temperature of 5 to -60°C and an average particle size. 0.2μ or more,
A latex having a gel content of 50% by weight or more in the polymer solid; is mixed in a latex state, and the resin solid content is precipitated to form a thermoplastic resin composition, and an acrylic monomer and an aromatic vinyl monomer are added to the thermoplastic resin composition. A thermoplastic resin composition containing a copolymer consisting of a polymer. 4 The resin solid content in component (B) is 2 to 2 of the total resin solid content.
30% by weight of the thermoplastic resin composition of claim 3.