JPH0157138B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is directed to a vinyl chloride copolymer that provides molded products with excellent matteness and uniform surface irregularities.
In particular, the present invention relates to a vinyl chloride resin composition containing a vinyl chloride copolymer with significantly improved thermal stability.
More specifically, vinyl chloride, or a mixture of one or more monomers capable of copolymerizing vinyl chloride, and bisphenol A-modified diacrylate or bisphenol A-modified dimethacrylate represented by general formula (1) below are copolymerized. This invention relates to a resin composition containing a vinyl chloride-based copolymer that can be obtained by using a polyvinyl chloride copolymer.The molded product obtained from the resin composition can be easily matted, the surface irregularities of the molded product can be very uniform, and the thermal stability is extremely good. be. Vinyl chloride resin is inexpensive, and its molded products have excellent mechanical properties, weather resistance, oil resistance, etc., and are therefore widely used in various fields. (Conventional technology and problems) However, under normal processing conditions, vinyl chloride resin cannot make the surface of the molded product matte.
In addition, lowering the processing temperature or using a large amount of filler to make the product matte has the disadvantage of decreasing mechanical properties, and furthermore, if the process is made matte by embossing or acrylic painting, the molded product will deteriorate. There were inconveniences such as increased costs. However, in recent years, in molded products in various fields,
Matte surfaces with a luxurious feel have come to be preferred, and from the viewpoint of mechanical strength and good tactility, even surface irregularities and fine-grained surfaces have come to be preferred. In order to meet these demands, proposals have already been made to generate gel components during polymerization using crosslinking agents such as diallyl phthalate, diallyl maleate, polyethylene glycol diacrylate, and polyethylene glycol dimethacrylate to obtain a matte surface. However, the vinyl chloride polymers obtained by these techniques have significantly higher thermal stability than ordinary vinyl chloride resins. In the processing of ordinary vinyl chloride resin, it is necessary to use a large amount of heat stabilizer, which increases costs, and changes in processing conditions, such as lowering the processing temperature, can cause Attempts to compensate for the poor stability resulted in problems such as insufficient kneading, resulting in deterioration of the physical properties of the molded product. (Means for solving the problem) In order to improve these drawbacks, as a result of intensive research, we found that bisphenol A represented by the general formula (1) below.
The present inventors have discovered that thermal stability is significantly improved by using modified diacrylates or bisphenol A-modified dimethacrylates, and have completed the present invention. That is, the present invention combines vinyl chloride, or a mixture of one or more monomers copolymerizable with vinyl chloride, and bisphenol A-modified diacrylate or bisphenol A-modified dimethacrylate represented by the following general formula (1). A vinyl chloride copolymer obtained by polymerization,
The contents include a normal vinyl chloride resin or a vinyl chloride resin composition comprising a vinyl chloride resin. (X is a group selected from a hydrogen atom, a methyl group, and a hydroxyl group, and n is an integer of 1 to 80) The main object of the present invention is to use vinyl chloride or a mixture of one or more monomers copolymerizable with vinyl chloride. By using a vinyl chloride copolymer obtained by copolymerizing bisphenol A-modified diacrylate or bisphenol A-modified dimethacrylate represented by the general formula (1) above, the surface unevenness is uniform and the texture is uniform. To provide a vinyl chloride-based resin composition containing a vinyl chloride-based copolymer, from which a molded article with fine texture and good texture and matte finish can be easily obtained. That is, by blending stabilizers, lubricants, antioxidants, rubbers, ultraviolet absorbers, processing aids, pigments, etc. into the resin composition containing the copolymer and processing it, various types of materials in the hard field can be used. By adding a plasticizer to soften the molded products, various molded products in the soft field can be made with uniform surface irregularities.
It is fine-grained, has a good texture, and can be made matte. The reason why the thermal stability of the copolymer obtained by using the bisphenol A-modified diacrylate or the bisphenol A-modified dimethacrylate represented by the general formula (1) is significantly improved is not yet clear. However, since various derivatives of bisphenol A have been added to polyvinyl chloride and the like as heat stabilizers, it is presumed that bisphenol residues have the effect of improving thermal stability. In addition, a gel component is generated by crosslinking by the functional groups at both ends, and the gel component remains in the molded product, resulting in a uniform, fine-grained surface, good texture, and matte finish. The bisphenol A-modified diacrylate or bisphenol A-modified dimethacrylate used in the present invention includes Viscoat #540, Viscoat #700 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), and XD8008.01.
(manufactured by Dow Chemical Company) etc. are commercially available. The vinyl chloride copolymer of the present invention can be produced by suspension polymerization, emulsion polymerization, bulk polymerization, solution polymerization, etc.
Although any conventionally known polymerization method may be used, a suspension polymerization method is preferred from the viewpoint of ease of production and production cost. The amount of the compound used in the present invention is 0.001 parts by weight to 15 parts by weight based on 100 parts by weight of vinyl chloride monomer.
The amount is preferably 0.01 to 5 parts by weight, particularly preferably 0.01 to 5 parts by weight. Further, when adding the compound, the operation of adding it afterward during the polymerization does not impair the object of the present invention. The polymerization temperature in suspension polymerization is not particularly limited, but is preferably from 20°C to 80°C. Further, changing the polymerization temperature during the polymerization does not impair the purpose of the present invention. The initiator used in suspension polymerization may be any initiator that is normally used in the polymerization of vinyl chloride resins, such as lauryl peroxide, di-2-ethylhexyl peroxydicarbonate, isopropyl peroxy Organic peroxides such as dicarbonate, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxypivalate, azo radicals such as azobisisobutyronitrile, azobisvaleronitrile, etc. One or more of the initiators can be used. moreover,
The purpose of the present invention is not changed by operations such as adding these initiators midway through the process. Dispersants used in suspension polymerization include partially saponified polyvinyl acetate, methylcellulose, hydroxypropoxymethylcellulose, ethylcellulose, hydroxyethylcellulose, polyvinylpyrrolidone,
Known dispersants such as a copolymer of maleic anhydride and methyl vinyl ether, organic polymer dispersants such as gelatin, casein, and starch, and inorganic dispersants such as talc, calcium sulfate, and calcium phosphate can be used alone or in combination. . Furthermore, the object of the present invention is not impaired even if such operations as post-addition of these dispersants during polymerization are performed. In the present invention, the monomer forming the main chain is vinyl chloride alone or a mixture of at least 50% by weight of vinyl chloride and a vinyl monomer copolymerizable therewith. Monomers copolymerizable with vinyl chloride include vinyl esters such as vinyl acetate,
Examples include vinyl ethers such as methyl vinyl ether, acrylic acid or methacrylic acid and its esters, maleic acid or fumaric acid and its esters or anhydrides, aromatic vinyl compounds, vinylidene halides, and vinyl monomers such as monoolefins. Ru. In addition, in the present invention, there is no problem in performing operations such as adding these monomers midway, and depending on the reactivity ratio of these monomers, the final molecule This can be done depending on the design. Furthermore, in the present invention, addition of various additives, such as antioxidants, ultraviolet absorbers, heat stabilizers, lubricants, rubbers, etc., which are usually used to modify vinyl chloride resin, or polymerization and Addition of a buffer, etc. to ensure stability does not change the gist of the present invention in any way and can be employed as appropriate depending on the purpose. The copolymer in the composition of the present invention can be used in both hard and soft fields. That is, by blending rubbers, stabilizers, lubricants, antioxidants, ultraviolet absorbers, processing aids, pigments, etc. with the copolymer and processing it, molded articles for hard applications are obtained. Further, by using the copolymer in combination with an ordinary vinyl chloride resin or vinyl chloride resin to obtain a resin composition containing the copolymer, the properties of the copolymer can be fully exhibited. Rubbers that can be used in the present invention include:
Examples include NBR, EPDM, SBR, silicone rubber, natural rubber, polybutadiene, neoprene rubber, isoprene rubber, MBS, EVA, etc. As the stabilizer, one type or a combination of two or more of tin type stabilizers, lead type stabilizers, metal soaps, Ca-Zn type stabilizers, Ba type stabilizers, etc. are used. As the lubricant, one or more of polyethylene wax-based lubricants, stearic acid-based lubricants, alcohol-based lubricants, etc. are used in combination. The elastic vinyl chloride resin used in the present invention is a copolymer containing at least 50% by weight of vinyl chloride, such as a copolymer with vinyl esters such as vinyl acetate, methyl vinyl ether, etc. Copolymers with vinyl ethers of , copolymers with vinyl monomers such as vinylidene halide or monoolefin, and the like. Furthermore, by adding a plasticizer to the copolymer, it is also possible to obtain soft molded products. The amount of plasticizer that can be used is not particularly limited, and may be adjusted as necessary. Furthermore, the plasticizer used is not particularly limited, and one or two of commonly used phthalic acid plasticizers, epoxy plasticizers, phosphate ester plasticizers, polyester plasticizers, etc. More than one species can be used together. (Effects of the Invention) When the vinyl chloride resin composition containing the vinyl chloride copolymer of the present invention is made into a molded article, it is easily matted, and the surface irregularities of the molded article are very uniform.
Further, as shown in the Examples, the resin composition of the present invention is industrially excellent since it exhibits an effect of excellent thermal stability. (Example) Next, embodiments of the present invention will be further clarified by Examples, but these are not intended to limit the scope of the present invention. Reference Examples 1 to 8 In a stainless steel polymerization vessel with an internal volume of 300, 200 parts of ion-exchanged water, 0.2 parts of partially saponified polyvinyl acetate, 0.06 parts of diisopropyl peroxide, 0.06 parts of di-2-ethylhexyl peroxydicarbonate, and 100 parts of vinyl chloride monomer. Viscoat #540 or Viscoat #700 was added in the amounts shown in Table 1 and polymerized at a polymerization temperature of 35° C. for 15 hours. The obtained slurry was dehydrated, dried in a hot air dryer at 5° C. for 18 hours, and used for each measurement. Comparative Examples 1 to 6 In the same manner as in Reference Examples, predetermined amounts of ion-exchanged water, partially saponified polyvinyl acetate, diisopropyl peroxide, di-2-ethylhexyl peroxydicarbonate, vinyl chloride monomer, and the crosslinking agent shown in Table 1 were added. Polymerization was carried out at a charging polymerization temperature of 35°C for 15 hours. It was dried in the same manner as in the reference example and used for each measurement. In addition, each physical property value was measured as follows. (1) Preparation of test piece: Blend Sample copolymer 100 parts by weight Dioctyl phthalate 100 Tribasic lead sulfate 3 Lead stearate 1 Calcium carbonate 30 Blend the mixture at a roll temperature of 185℃. Knead for 10 minutes to produce a masticated sheet with a thickness of approximately 0.7 m/m, and press at a pressing temperature of 190°C.
A sample sheet for measurement was prepared by press molding at a pressure of 200 kg/cm ² . (2) Compression set: In accordance with JIS-K6301, the compression conditions were a compression ratio of 25% and a temperature of 70°C for 22 hours. (3) Tensile strength: A test piece was punched out from a press-formed sheet in accordance with JIS-K6723, and measured using a tensile tester at a measurement temperature of 25°C and a tensile speed of 200 mm/min. (4) HC1 removal rate: Automatic titrator AT-
107 (manufactured by Kyoto Denshi Kogyo Co., Ltd.) at an oil bath temperature of 235°C, a N ₂ flow rate of 20 ml/min, and a titration rate of 0.02 ml/min.
After placing 10g of the sample (masticated sheet cut into approximately ^3mm2 pieces) in an oil bath,
The time required for the amount of NaOH solution used to reach 5.0 ml was determined.

【table】

[Table] From Table 1, when the copolymer is softened, the balance between compression set and tensile strength becomes better, and
It can be seen that the HC1 speed has become extremely long, indicating that the thermal stability has been significantly improved. Examples 1 to 8, Comparative Examples 7 to 14 The copolymers obtained in Reference Examples 3 and 7, the copolymers obtained in Comparative Examples 2 and 5, and vinyl chloride homopolymer (700) or Vinyl chloride vinyl acetate copolymer (VAc content 8%, 700) was blended with 2 parts of tin stabilizer, 0.5 part of stearic acid, and 0.5 part of pigment to the total resin at the blend ratio shown in Table 2, and then rolled. Knead for 7 minutes at a temperature of 180℃, 0.6mm
A thick sheet was obtained. The surface condition of the roll sheet was visually evaluated and the results are shown in Table 2.

[Table] From the results in Table 2, the matte state is almost the same as the comparative example, but the surface unevenness is improved.
It can also be seen that the GO blackening time has been greatly improved. The GO blackening time was measured under the following conditions. The sheets obtained in Examples 1 to 8 and Comparative Examples 7 to 14 were cut into 3 cm x 6 cm pieces, placed in a gear type aging tester preheated to an atmosphere of 200°C, and the sheets were cut every 15 minutes. The sheet piece was taken out, and the degree of coloring of the sheet piece was observed with the naked eye, and the time required for the sheet piece to become black was determined.

Claims (1)

[Scope of Claims] 1. Vinyl chloride, or a mixture of one or more monomers copolymerizable with vinyl chloride, and bisphenol A-modified diacrylate or bisphenol A-modified dimethacrylate represented by the following general formula (1). (0.001 to 15 parts by weight based on 100 parts by weight of vinyl chloride monomer), and a vinyl chloride copolymer formed by copolymerizing a vinyl chloride-based copolymer with a normal vinyl chloride resin or a vinyl chloride-based resin. based resin composition. (X represents a group selected from a hydrogen atom, a methyl group, and a hydroxyl group, and n represents an integer from 1 to 80.)