JPH0572419B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel acrylic resin composition suitable for use as a film that has excellent impact resistance, weather resistance, and water absorption resistance and has a good matte surface, and a film made of the resin composition. Conventional methods for matting plastic materials include kneading inorganic fillers, kneading crosslinkable polymer particles, applying surface treatment agents, physical or chemical surface treatment, and imparting a matte surface through molding conditions. However, most of the matting methods for acrylic films (usually less than 200 μm in thickness) are those described above. However, when fine particles such as calcium carbonate, calcium silicate, silica gel, etc. are mixed as an inorganic filler, physical properties such as impact resistance and tensile strength are significantly reduced, and furthermore, water absorption and whitening properties are poor. On the other hand, when kneading crosslinkable polymer particles, it is difficult to adjust the degree of dispersion by changing processing conditions.
Not only is it difficult to obtain an elegant matte surface, but since it is a crosslinked polymer with a high glass transition temperature (Tg), it has the disadvantage of poor impact resistance at low temperatures. In view of these circumstances, the present inventors have completed the present invention as a result of intensive research to overcome the above-mentioned drawbacks. That is, the first aspect of the present invention is based on 100 parts by weight of an acrylic resin, 50 to 100 parts by weight of an acrylic acid alkyl ester having an alkyl group having 1 to 13 carbon atoms, and a methacrylic acid alkyl ester having an alkyl group having 1 to 13 carbon atoms. 100 parts by weight of a non-crosslinking monomer consisting of 0 to 50 parts by weight and 0.25 to 17 parts by weight of a crosslinking monomer having two or more double bonds in the molecule, having a glass transition point of 30°C or less and having an average particle size. The second aspect of the present invention is to provide a matting acrylic resin composition characterized in that 5 to 50 parts by weight of a matting crosslinked acrylic copolymer having a diameter of 0.3 to 10μ is uniformly mixed and dispersed. Based on 100 parts by weight of the system resin, 50 to 100 parts by weight of an acrylic acid alkyl ester having an alkyl group having 1 to 13 carbon atoms, and 0 to 100 parts by weight of a methacrylic acid alkyl ester having an alkyl group having 1 to 13 carbon atoms.
A glass transition point consisting of 100 parts by weight of a non-crosslinking monomer consisting of 50 parts by weight and 0.25 to 17 parts by weight of a crosslinking monomer having two or more double bonds in the molecule.
A resin composition with a thickness of 10 to 10% obtained by extrusion molding a resin composition in which 5 to 50 parts by weight of a matting acrylic copolymer with an average particle size of 0.3 to 10μ is uniformly mixed and dispersed at 30°C or less
Each contains a 200μ matte acrylic film. Examples of the acrylic acid alkyl ester having 1 to 13 carbon atoms in the alkyl group of the acrylic copolymer used in the present invention include ethyl acrylate, acrylic acid n
-butyl, 2-ethylhexyl acrylate, etc., and are used in an amount of 50 to 100 parts by weight. If it is less than 50 parts by weight, the glass transition point will be higher than room temperature, making it difficult to obtain the advantage of impact resistance at low temperatures. The methacrylic acid alkyl ester having an alkyl group having 1 to 13 carbon atoms includes lower methacrylic esters such as methyl methacrylate, ethyl methacrylate, and n-butyl methacrylate, and is used in an amount of 0 to 50 parts by weight. If it exceeds 50 parts by weight, the glass transition point will be higher than room temperature, making it difficult to obtain the advantage of impact resistance at low temperatures. Examples of crosslinkable monomers having two or more double bonds in the molecule include unsaturated carboxylic acid esters of alkylene glycol such as ethylene glycol dimethacrylate, unsaturated alcohol ethers of alkylene glycol such as propylene glycol diallyl ether, divinylbenzene, etc. Allyl group-containing crosslinkable monomers such as polyvalent vinylbenzene, allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, etc. are mentioned, and 0.25 to 17 parts by weight per 100 parts by weight of the non-crosslinkable monomer,
More preferably, it is blended in an amount of 0.5 to 10 parts by weight. If the amount is less than 0.25 parts by weight, a sufficient crosslinked polymer will not be obtained, and the matting effect will not be sufficiently developed. on the other hand,
Even if more than 17 parts by weight is used, no improvement in physical properties can be expected. The average particle diameter of the acrylic copolymer is 0.3 to 10μ. If it is less than 0.3μ, the matting effect is not sufficient;
If it exceeds 10μ, the surface becomes rough and matte, which is unfavorable in terms of appearance. In addition, Tg (calculated value) is below 30℃, 30
If the temperature exceeds .degree. C., the crosslinked acrylic polymer for matting will exist as a hard component even at room temperature, resulting in insufficient tensile strength and impact resistance at low temperatures when made into a film. The acrylic copolymer of the present invention can be obtained by a fine suspension polymerization method in which monomers and a polymerization initiator are dispersed in water in the presence of a surfactant. As the polymerization initiator, those used in normal suspension polymerization are used, and typical examples include organic peroxides such as benzoyl peroxide and lauroyl peroxide, and azo compounds such as azobisisobutyronitrile. be able to. As surfactants, higher fatty acid salts such as sodium oleate and sodium stearate, potassium rosinate,
Rosinate salts such as sodium rosinate, higher alcohol sulfates such as sodium octyl sulfate and sodium lauryl sulfate, higher alkylaryl sulfonates such as sodium dodecylbenzenesulfonate, and dialkyl sulfosuccinates such as sodium di-2-ethylhexyl sulfosuccinate. Examples include anionic surfactants such as acid salts, nonionic surfactants such as polyethylene glycol fatty acid esters, and higher alcohols having an alkyl group of 12 to 18 carbon atoms, either alone or in combination. The particle size is adjusted to 0.3 to 10μ as described above, but the particle size is adjusted by combining the type and amount of surfactant, polymerization initiator, water/monomer ratio, stirring conditions, etc. in balance with the monomer composition. . The particle size is measured using "Coal Counter" manufactured by Coulter Electronics Inc., and the point at which it reaches 50% on the cumulative curve is defined as the average particle size. Further, the Tg of the copolymer is controlled to be 30°C or less, but this control is mainly determined by the monomer composition. For example, in the case of methyl methacrylate and butyl acrylate, the former should be 60 parts or less, and the latter should be 40 parts or more. In the case of tertiary butyl methacrylate and 2-ethylhexyl acrylate, 50 parts or less of the former and 50 parts or less of the latter.
Must be 50 copies or more. Therefore, the proportions of each component of the present invention are selected within the above ranges. The crosslinked acrylic polymer for matting obtained as described above is uniformly mixed with an acrylic resin. The acrylic resin used in the present invention includes:
Elastic material with an average particle size of 0.2μ or less, a core of 20 to 50% by weight of an elastic component with a crosslinked structure containing 50 parts by weight or more of an acrylic acid alkyl ester, and a non-crosslinked structure containing 50 parts by weight or more of a methacrylic acid alkyl ester. Acrylic resin consisting of 80 to 50% by weight of the shell resin layer is suitable. In this case, in a preferred embodiment, the crosslinked acrylic copolymer for matting is stored in a solution state,
It is uniformly mixed with a polymerization solution of an acrylic resin that will become the base resin of the film, and is taken out as a powder through known coagulation and drying. The polymerization solution of acrylic resin used in the present invention refers to an emulsified dispersion of acrylic resin used as a raw material for acrylic film.
For example, 20 to 50% by weight of an elastomer component with an average particle size of 0.2 μ or less and a crosslinked structure containing 50 parts by weight or more of an acrylic acid alkyl ester is used as the core, and a non-crosslinked structure (external) containing 50 parts by weight or more of a methacrylic acid alkyl ester. Shell resin layer) Polymer particles consisting of 80 to 50% by weight are emulsified and dispersed in an aqueous system. The solid content ratio of the acrylic resin polymerization solution (solid content B) and the crosslinked acrylic copolymer solution for matting (solid content A), that is, (solid content B)/(solid content A) is 2 to 20. mixed in the same way. If the solid content ratio is less than 2, the softening point of the composition will be too low, and if it exceeds 20, a good matting effect will not be achieved. The composition of the acrylic resin and the crosslinked acrylic copolymer for matte use may contain additives such as stabilizers, lubricants, processing aids, impact resistance aids, fillers, colorants, ultraviolet absorbers, It can contain an infrared absorber and the like. The above composition can be made into a matte film by known methods such as T-die processing, inflation processing, and calendar processing. The matte film has a thickness
10 to 200μ, and the degree of matteness is 50 or less on a 60 degree gloss level. The resulting matte film can be laminated to other transparent plastic materials, wallpaper or canvas,
By laminating the product to an iron plate or the like, it is possible to provide a product with a beautiful appearance, and at the same time, it is possible to provide a product that has the property of resisting oil breakage and the property of resisting deterioration in appearance due to water absorption. The present invention will be described below with reference to Examples and Comparative Examples, but the present invention is not limited by these in any way. Example 1, Comparative Examples 1 to 3 (1) Production of crosslinked acrylic copolymer for matte use A glass reaction vessel equipped with a stirrer (H type propeller), reflux condenser, and nitrogen gas inlet was placed in a water bath. and charged with the following reactants. Methyl methacrylate 10 parts by weight Butyl acrylate 90 Allyl methacrylate 2 2-2'-Azobis-(2,4-dimethylvaleronitrile) 0.1 Sodium lauryl sulfate 1 Higher alcohol 1 Water 400 After sufficiently replacing the inside of the reaction vessel with nitrogen gas,
The reaction material was stirred at room temperature for 1 hour at a stirring speed of 800 rpm. Then, the stirring speed was increased to 200 rpm and the temperature was increased to 60°C.
The mixture was heated to start polymerization. 80 more in 3 hours
The temperature was raised to .degree. C., and polymerization was completed for 1 hour.
The crosslinked acrylic copolymer had a Tg of -44°C and an average particle size of 1μ. (2) Production of acrylic resin A glass reaction vessel equipped with a stirrer (H-type propeller), a reflux condenser, and a nitrogen gas inlet was set in a water bath, and the following reactants were charged. Water 200 parts by weight Sodium dialkyl sulfosuccinate
0.8 Higher alcohol 0.3 Butyl acrylate 27 Methyl methacrylate 3 Triallyl isocyanurate 0.3 Qyumene hydroperoxide 0.1 After raising the temperature to 40℃ and stirring, add 0.1 part by weight of sodium formaldehyde sulfoxylate dissolved in a small amount of water. , started polymerization. It was confirmed that the conversion rate was over 95%. The particle size of the obtained latex was 1450 Å. The water bath temperature was then raised to 80° C. and the following mixture was added continuously over 4 hours. Methyl methacrylate 59 parts by weight Butyl acrylate 11 Kyumene hydroperoxide 0.4 It was confirmed that the polymerization heat generation had ended and the conversion rate was 95% or higher. The particle size of this latex is 1610Å
It was hot. A portion of this latex is salted with a CaCl ₂ aqueous solution, heated to 80°C or higher, dehydrated, and dried. The white powder obtained can be used as it is as a variety of molding materials, but it is also possible to mix it with various additives. It is. Comparative Example 1 shows the obtained white powder and an example in which silica and a commercially available organic matting agent were respectively blended.
~3. (3) Compounding of crosslinked acrylic copolymer for matting and acrylic resin and film molding For 100 parts of the polymer solution (solid content B) of acrylic resin obtained in (2) above, add 1 ) Crosslinked acrylic copolymer for matte use (solid content A) 10
The mixture was mixed uniformly so as to give a uniform volume of 50%, solidified by adding an aqueous calcium chloride solution, washed and dried to obtain a powder. The powder was extruded into pellets using an extruder with a 40 mm diameter screw. The obtained pellets were put in a dry state into an inflation extruder having a screw diameter of 40 mm to obtain a film with a thickness of 50 μm. (4) Physical properties of the film The water absorption and whitening properties of the above film and the PVC steel plate
The film was heated at 210° C. for 2 minutes and laminated with a rubber roll, and its gloss and impact resistance were observed. The results are shown in Table 1.

【table】

[Table] As is clear from Table 1, the product containing the crosslinked acrylic copolymer of the present invention has the same matting effect as Comparative Example 2, which contains an inorganic substance, and the physical properties of the laminate product are The result was approximately the same as Comparative Example 1 in which the film was not blended, and the matte film as a whole was extremely excellent. Examples 2 to 5, Comparative Examples 4 to 5 (1) Production of crosslinked acrylic copolymer for matte use The monomer components constituting the crosslinked acrylic copolymer were carried out in the proportions shown in Table 2. A crosslinked acrylic copolymer latex was obtained in the same manner as in Example 1 (1). Table 2 shows the Tg and average particle size of the crosslinked acrylic copolymer obtained.

[Table] (2) to (4) Production, blending, film formation, and physical properties of acrylic resin Acrylic resin was produced in the same manner as in Example 1 (2), blended in the same manner as in Example 1 (3), and Physical properties were observed in the same manner as (4). The results are shown in Table 3.

【table】

[Table] Comparative Example 6 A crosslinked acrylic copolymer was obtained in the same manner as in Example 1(1) except that the initiator used was changed to lauroyl peroxide. The crosslinked acrylic copolymer obtained had a Tg of -44°C and an average particle size of 60μ.
This was separated using a 400-mesh sieve, and the 60° gloss of the vinyl chloride laminate product was measured according to Examples 1 (2) to (4). The results are shown in Table 6. Comparative Example 7 A crosslinked acrylic copolymer with a Tg of -44°C and an average particle size of 0.2μ was obtained in the same manner as in Example 1(1), except that the surfactant used was changed as shown in Table 5. . The resulting crosslinked acrylic copolymer was laminated with vinyl chloride and its 60° gloss was measured according to Examples (2) to (4). The results are shown in Table 6.

【table】

【table】

Claims (1)

[Claims] 1. Emulsified dispersion of acrylic resin (solid content B)
and 50 to 100 parts by weight of an alkyl acrylate having an alkyl group of 1 to 13 carbon atoms, and 0 to 50 parts by weight of an alkyl methacrylate having an alkyl group of 1 to 13 carbon atoms.
obtained by fine suspension polymerization of 100 parts by weight of a non-crosslinkable monomer consisting of 100 parts by weight and 0.25 to 17 parts by weight of a crosslinkable monomer having two or more double bonds in the molecule,
Glass transition point is below 30℃ and average particle size is 0.3~
A matte acrylic product characterized in that a 10 μm crosslinked acrylic copolymer aqueous dispersion (solid content A) is uniformly mixed and dispersed in a range of (B)/(A) = 2 to 20. Aqueous resin dispersion. 2 The emulsified dispersion of acrylic resin has an average particle size of
The core is 20 to 50% by weight of an elastomer component with a crosslinked structure that is 0.2 μ or less and contains 50 parts by weight or more of an acrylic acid alkyl ester, and a methacrylic acid alkyl ester.
Outer shell resin layer with non-crosslinked structure containing 50 parts by weight or more
The resin aqueous dispersant according to claim 1, wherein 80 to 50% by weight of polymer particles are emulsified and dispersed in an aqueous system. 3 Emulsified dispersion of acrylic resin (solid content B)
and 50 to 100 parts by weight of an alkyl acrylate having an alkyl group of 1 to 18 carbon atoms, and 0 to 50 parts by weight of an alkyl methacrylate having an alkyl group of 1 to 13 carbon atoms.
obtained by fine suspension polymerization of 100 parts by weight of a non-crosslinkable monomer consisting of 100 parts by weight and 0.25 to 17 parts by weight of a crosslinkable monomer having two or more double bonds in the molecule,
Glass transition point is below 30℃ and average particle size is 0.3~
A resin separated from a resin aqueous dispersion in which a 10 μ matting acrylic copolymer aqueous dispersion (solid content A) is uniformly mixed and dispersed in the range of (B)/(A) = 2 to 20 is molded. The resulting matte acrylic film has a thickness of 10 to 200μ. 4 The emulsified dispersion of acrylic resin has an average particle size of
The core is 20 to 50% by weight of an elastomer component with a crosslinked structure that is 0.2 μ or less and contains 50 parts by weight or more of an acrylic acid alkyl ester, and a methacrylic acid alkyl ester.
Outer shell resin layer with non-crosslinked structure containing 50 parts by weight or more
4. The film according to claim 3, wherein 80 to 50% by weight of polymer particles are emulsified and dispersed in an aqueous system.