JPS6234786B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vinyl chloride resin composition that can produce molded articles with matte surfaces. PVC molded products such as electric wires, hoses, tubes, and gaskets are required to have matte surfaces depending on their intended use. Conventionally, in order to obtain matte molded products from vinyl chloride resin, methods such as lowering the molding resin temperature during molding, adding inorganic fillers, and acrylic There are methods of adding resins such as resins, nitrile rubber, and ethylene-vinyl acetate copolymers, and methods of roughening the surface of the molding die or mold, but none of these methods are satisfactory. Nakatsuta. for example,
When the molding resin temperature was lowered, it was not possible to impart sufficient strength to the molded product, and when extrusion molding was performed at low temperatures, it was difficult to maintain a constant extrusion temperature, resulting in uneven matte state. . When adding fillers or other resins, if the amount added is small, the matting effect will not be sufficient, while if added in a large amount, the molding processability, electrical properties, and heat resistance of the molded product will likely be impaired, and the molded product The surface became rough easily, and the molded product also became easily broken. If the surface of the die is made rough, the flow of the resin tends to be uneven, which has a large effect on the thermal decomposition of the resin, and it is impossible to produce a satisfactorily matte molded product using either method. I couldn't do it. The inventors of the present invention have conducted intensive studies to produce matte molded products without significantly changing the molding temperature of ordinary vinyl chloride resin, and without deteriorating the physical properties of the molded product. We have discovered that matting can be achieved by using a special crosslinked vinyl chloride copolymer containing vinyl monomer as the main component, and have arrived at the present invention. That is, an object of the present invention is to provide a vinyl chloride resin composition from which a matte molded article can be obtained. The present invention is based on the previously proposed patent application No. 53-
72922 invention (a composition containing a copolymer of a vinyl chloride monomer and a comonomer having a plurality of active double bonds in the molecule as one component) and Japanese Patent Publication No. 1987-
This invention is an improvement on the invention of No. 45422 (a vinyl chloride resin composition comprising a crosslinked vinyl chloride resin with a particle size of 10 μm or less and a non-crosslinked vinyl chloride resin). These compositions had the disadvantages that, compared to the present invention, the former had inferior melt flowability, the appearance of the molded product after processing was slightly inferior, and the latter could not produce a matte molded product. However, it has surprisingly been found that the composition of the present invention can provide a molded article with an extremely large matte effect without reducing moldability, mechanical strength, etc. Therefore, the gist of the present invention is to provide a vinyl chloride monomer or a mixture of a vinyl chloride monomer and a comonomer copolymerizable with the vinyl chloride monomer, which has a plurality of active double bonds in the molecule, and which is copolymerizable with the monomer or comonomer. Gel fraction of 3% or more and less than 60% obtained by reaction with a compound that can
100, a vinyl chloride resin composition consisting of a vinyl chloride copolymer with an average particle size of 10 to 70μ and other components. To explain the present invention in detail, a compound having a plurality of active double bonds in its molecule refers to an active double bond that exhibits radical polymerization behavior between vinyl chloride or a comonomer that can be copolymerized with a vinyl chloride monomer. It is desirable to have 2 to 3 bonds, and also to be able to easily copolymerize with vinyl chloride monomer or comonomer. Examples of the compounds include diallyl compounds, triallyl compounds, divinyl compounds, diacrylic or triacrylic compounds, and specific examples include diallyl phthalate, diallyl adipate, diallyl maleate, diallyl succinate, diallyl carbinol. , triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, divinylbenzene, divinyl ether, divinyl sulfone, 2,6-diacrylphenol, glycerin triacrylate, glycerin trimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate Among these, diallyl phthalate and triallyl cyanurate are particularly preferred. These compounds act as crosslinking agents in the vinyl chloride copolymer produced. However, the compound (hereinafter referred to as "crosslinking agent") used in the copolymer is not limited to one type, and it goes without saying that two or more types may be used. The ratio of vinyl chloride monomer and crosslinking agent used depends on the copolymer manufacturing conditions, etc., but the latter is usually used in the range of 0.001 to 1% by weight based on the total amount of vinyl chloride monomer and crosslinking agent. The content is preferably within the range of 0.05 to 0.5% by weight. The amount of crosslinking agent is 0.001% by weight
When the amount is less than 1% by weight, the crosslinking effect due to copolymerization is hardly observed, whereas when the amount is more than 1% by weight, the melt fluidity is hindered by the network structure, and molding is often difficult. Further, when copolymerizing a mixture of a vinyl chloride monomer and a comonomer described below with a crosslinking agent, the amount of the crosslinking agent is preferably determined in consideration of the copolymerizability of the comonomer with the crosslinking agent. Examples of comonomers copolymerizable with vinyl chloride monomers that can be used in the production of vinyl chloride copolymers include olefins such as ethylene and propylene, vinyl esters such as vinyl acetate and vinyl stearate, ethyl vinyl ether, and cetyl vinyl ether. Examples include vinyl ethers such as butyl acrylate, acrylic esters such as methyl methacrylate, anhydrides or esters of maleic acid and fumaric acid, nitrile compounds such as acrylonitrile, and other styrene, acrylic acid, and methacrylic acid. There are no particular restrictions as long as it does not have a plurality of active double bonds in its molecule and can be copolymerized with vinyl chloride monomer. Further, the amount of the comonomer used is preferably 30% by weight or less based on the total amount of the comonomer and the vinyl chloride monomer. The vinyl chloride copolymer used in the composition of the present invention is prepared by combining a vinyl chloride monomer or a mixture of a vinyl chloride monomer and a comonomer copolymerizable therewith with a crosslinking agent, such as diisopropyl peroxydicarbonate, di-2 - Organic peroxides such as ethylhexyl peroxydicarbonate, acetylcyclohexylsulfonyl peroxide, t-butylperoxypivalate, and lauroyl peroxide; Various methods such as suspension polymerization, emulsion polymerization, solution polymerization, or bulk polymerization are carried out in the presence of oil-soluble polymerization initiators such as compounds, suspending agents such as partially saponified polyvinyl acetate, cellulose derivatives, emulsifiers thereof, and other auxiliaries. Adopted and manufactured. The vinyl chloride copolymer used in the composition of the present invention can be produced by appropriately selecting the manufacturing conditions.
Gel fraction 3% or more but less than 60%, swelling degree 5~5
100 and the average particle size is 10~70μ, preferably 30~60
It needs to be in the μ range. Manufacturing conditions can be determined empirically and without any difficulty. In addition, copolymers obtained by emulsion polymerization generally cannot be used as they are because they are fine particles with a particle size of 2 to 3 μm or less, but they can be further seeded and polymerized using these fine particles as seeds. It may be used by increasing the particle size. The vinyl chloride resin composition of the present invention has as one component the vinyl chloride copolymer thus obtained with a gel fraction of 3% to less than 60%, a degree of swelling of 5 to 100, and an average particle size of 10 to 70μ. For example, only the polymer is used as a resin component, and 20 to 300 parts by weight, preferably 20 to 300 parts by weight of a plasticizer used for ordinary vinyl chloride resins such as dioctyl phthalate or dioctyl adipate, per 100 parts by weight of the polymer. It is used as a soft to semi-hard composition containing 30 to 150 parts by weight of the polymer, or as a hard composition containing appropriate amounts of an ultraviolet absorber, an antioxidant, a heat stabilizer, a lubricant, a flame retardant, etc. added to the polymer. Of course, the soft composition contains ultraviolet absorbers,
Various auxiliary agents such as antioxidants and heat stabilizers may be added. The vinyl chloride resin composition of the present invention has a vinyl chloride homopolymer or a vinyl chloride monomer as a resin component in addition to the above-mentioned copolymer, or a vinyl chloride monomer containing only one active double bond, such as vinyl acetate,
ethylene, propylene, styrene, acrylic acid,
Preference is given to mixing copolymers with comonomers such as methacrylic acid. The copolymer may be produced by any method such as suspension polymerization, emulsion polymerization, solution polymerization, or bulk polymerization, and its form may be random copolymer, alternating copolymer, block copolymer, or graft copolymer. It may be either combination. (Vinyl chloride homopolymers and copolymers are hereinafter simply referred to as "other vinyl chloride resins"). Gel fraction 3% or more but less than 60%, swelling degree 5-100,
The mixing ratio of the vinyl chloride copolymer with a particle size of 10 to 70 (hereinafter simply referred to as "vinyl chloride copolymer") and other vinyl chloride resin depends on the degree of polymerization of the vinyl chloride copolymer and the other vinyl chloride resin. Although it varies slightly depending on the degree of polymerization and the molding temperature,
Preferably, the proportion of the vinyl chloride copolymer is in the range of 1 to 80% by weight, particularly 5 to 70% by weight based on the total amount of both, since this may reduce the physical properties of the molded product obtained from the vinyl chloride resin composition. It is preferable from the viewpoint of maintaining good moldability and good moldability. In addition, even if the composition of the present invention is a mixture of a vinyl chloride copolymer and other vinyl chloride resin as a resin component, an appropriate amount of a plasticizer, an ultraviolet inhibitor,
Various auxiliary agents such as heat stabilizers, lubricants, fillers, colorants, and flame retardants can be added. The amount of plasticizer is suitably in the range of 20 to 300 parts by weight, preferably 30 to 150 parts by weight, based on 100 parts by weight of the resin component. When the composition of the present invention satisfies the requirements of a vinyl chloride copolymer, that is, a gel fraction of 3% or more and less than 60%, a swelling degree of 5 to 100, and an average particle size of 10 to 70μ, the composition has excellent moldability and mechanical properties. A molded product with an extremely large matte effect can be obtained without reducing the mechanical strength. If the gel fraction is 60% or more, the molding processability is poor and the molded product tends to have an extremely poor appearance.If the swelling degree is less than 5, the mechanical strength decreases and the molded product easily breaks. It becomes easier. Furthermore, if the average particle size of the vinyl chloride copolymer is less than 10μ, the matting effect will be insufficient, while if it is more than 70μ, the surface of the molded product will be easily roughened. Therefore, the gel fraction, degree of swelling, and average particle size were measured as follows. (1) Gel fraction: represents the degree of crosslinking. Accurately weigh 2 grams (gr) of vinyl chloride copolymer,
This was poured into a 500 milliliter (ml) glass beaker together with 400 gr of tetrahydrofuran (THF), stirred and dissolved at room temperature for 1 hour, and filtered to remove the undissolved vinyl chloride copolymer. The weight W ₁ gr of the undissolved matter after drying is accurately weighed and calculated using the following formula. Gel fraction (%)=W ₁ /2×100 (2) Swelling degree: represents crosslink density. Accurately weigh W ₂ gr of the vinyl chloride copolymer that does not dissolve in THF taken during gel fraction measurement, stir it again with 400 gr of THF for 1 hour, and then filter it.
Quickly remove excess weight when the THF layer is gone
W ₃ gr was accurately weighed and calculated using the following formula. Swelling degree = W ₃ /W ₂ (3) Average particle size Measured using a microscope in a conventional manner. The vinyl chloride resin composition of the present invention can be applied to any molding method such as extrusion molding, injection molding, rotary molding,
Applicable to press molding, especially in extrusion molding.
A more matte effect appears. The vinyl chloride resin composition of the present invention is composed of a vinyl chloride copolymer obtained by copolymerizing a vinyl chloride monomer and a crosslinking agent having a plurality of active double bonds, and It has a gel fraction of 60% or less, a swelling degree of 5 or more, is not completely crosslinked, has excellent compatibility with other vinyl chloride resins, and has physical properties compared to a mixture of completely crosslinked vinyl chloride copolymers. is also excellent. In addition, since the composition of the present invention contains a crosslinked vinyl chloride copolymer, it exhibits elasticity similar to rubber and has excellent tensile and electrical properties, and the crosslinked polymer is exposed on the surface of the molded product. As a result, extremely fine irregularities are formed and an excellent matting effect is exhibited, which has high utility value in, for example, the frames of fittings such as wheat bran, electric wire coverings, extruded hoses, etc. Further, the crosslinked copolymer, which is one component of the composition of the present invention, exhibits an excellent matting effect simply by adding a small amount of it to other vinyl chloride resins. EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. Reference Example The method for producing the vinyl chloride copolymer used in the Examples and Comparative Examples is as follows. 600g of distilled water and the suspension agent, polymerization initiator, and crosslinking agent in the proportions shown in Table 1 were put into a stainless steel autoclave with an internal volume of 3. After sealing the autoclave and completely removing the air inside, the vinyl chloride 300g of monomer (VCM) was added, and the temperature was raised to a specified reaction temperature to carry out a polymerization reaction. When the internal pressure of the autoclave became 1 kg/cm ² lower than the reaction pressure, unreacted VCM was removed and recovered, and the resulting copolymer was dehydrated and dried. Table 1 shows the gel fraction, degree of swelling, and average particle size of the copolymer obtained.

【table】

[Table] Examples 1 to 4 and Comparative Example 1 Vinyl chloride copolymer [A] and vinyl chloride homopolymer with a viscosity average degree of polymerization (according to JIS K-6721) 1300 were mixed in the proportions shown in Table 2, and the polymer Total amount
A vinyl chloride resin composition was prepared by blending 80 parts by weight of trioctyl trimellitate, 5 parts by weight of tribasic lead sulfate, and 0.5 parts by weight of stearic acid with respect to 100 parts by weight. The composition was extruded into a plate shape with a wall thickness of 1 mm at a die temperature of 185°C, and the tensile strength of the obtained molded product was measured using a Schottper type tensile tester, and the matte state and appearance of the surface of the extruded product were measured. was observed with the naked eye. A product containing only vinyl chloride homopolymer was similarly tested and is also listed in Table 2. The results of macroscopic observation were judged as follows, taking into account microscopic smoothness. 〇: Good, △: Possible, ×: Not possible

[Table] It is clear from Example 1 that the composition of the present invention exhibits a matting effect even when a small amount of vinyl chloride copolymer is added. The erasing effect is good. In addition, Example 4
The results show that the vinyl chloride copolymer alone has excellent matting effect and tensile strength, but the surface of the molded product is a little rough, and considering this point, it is comparable to other vinyl chloride copolymers. It turns out that combined use is preferable. Examples 5 to 8 and Comparative Examples 2 to 6 Vinyl chloride copolymers [A] shown in Table 1
[G] and a vinyl chloride homopolymer with a viscosity average degree of polymerization of 1300 were mixed at a ratio of 75:25, and 50 parts by weight of dioctyl phthalate was added to 100 parts by weight of the total amount of this polymer to prepare a composition. Extrusion molding was carried out in the same manner as in 1, the tensile strength of the obtained molded product was measured, and the matte effect and appearance of the molded product were observed. The results are shown in Table 3. In Comparative Examples 5 and 6, compositions were prepared by adding 5 parts by weight of finely divided silica and 60 parts by weight of calcium carbonate to 100 parts by weight of vinyl chloride homopolymer.

[Table] All of the compositions of the present invention are excellent in matte effect, surface appearance of molded products, tensile strength, etc. However, as seen in Comparative Examples 2, 3, and 4, those with a gel fraction of 60% or more, those with a swelling degree of 5 or less, or those with an average particle size outside the range of 10 to 70μ are not sufficient for the matting effect. However, all of them are inferior in terms of appearance or tensile strength. It is also found that simply adding another filler to the vinyl chloride homopolymer does not sufficiently improve the matting effect or the surface appearance of the molded article. Comparative Examples 7 to 14 150 parts by weight of deionized water, 0.1 parts by weight of polyvinyl alcohol, and 0.04 parts by weight of diallyl phthalate and di-sec-butyl peroxydicarbonate in the amounts shown in Table 4 were charged into the autoclave of Comparative Examples 7 to 14. Then, 100 parts by weight of vinyl chloride monomer was charged, and the temperature was raised to 40.5℃ with stirring, and at this temperature
Polymerization reaction was carried out for 17 hours to produce vinyl chloride copolymer [H]
～[O] was produced. The gel fraction, degree of swelling, and average particle size of these vinyl chloride copolymers were measured, and they were extruded into a plate shape with a wall thickness of 1 mm according to the method of Example 2, and the extruded product was matted. The effects and appearance are also listed in Table 4. Furthermore, as a means of determining whether the appearance is good or bad, the number of fisheyes is listed in Table 4. The number of fisheyes was measured as follows. 50 parts by weight of vinyl chloride copolymer, viscosity average degree of polymerization
1300 vinyl chloride homopolymer, 50 parts by weight of dioctyl phthalate, 3 parts by weight of tribasic lead sulfate, and 2 parts by weight of lead stearate to prepare each of vinyl chloride copolymers [H] to [O]. There are 8 types of compositions, and the compositions are made into a wall thickness of 0.2mm using a single screw extruder.
An extruded sheet was produced, and the number of fish eyes in a 100 mm ² square of the obtained sheet was determined.

[Table] Although Comparative Examples 11 to 14 had a matte effect, there were many fizzy eyes and the appearance was poor, making them unsuitable for practical use. Comparative Examples 7 to 10 had no matting effect at all,
Although there are relatively few fisheyes, the lack of a matting effect makes the fisheyes more conspicuous, and the appearance is worse than in Comparative Examples 11 to 14. This is because the vinyl chloride copolymer is harder than the vinyl chloride resin and has a larger average particle size, so it is not completely compatible with the vinyl chloride resin. Comparative Examples 15 to 21 150 parts by weight of deionized water, 0.1 parts by weight of polyvinyl alcohol, the prescribed parts by weight of the crosslinking agent shown in Table 5, and 0.04 parts by weight of di-sec-butyl peroxydicarbonate were charged into the autoclave of Comparative Examples 15 to 21. After stirring, 100 parts by weight of vinyl chloride monomer was charged, and then the temperature was raised to 43° C. with stirring, and a polymerization reaction was carried out at this temperature for 15 hours to obtain vinyl chloride copolymers [P] to [V]. The gel fraction, degree of swelling, and average particle size of these vinyl chloride copolymers were measured and are listed in Table 5. In addition, extrusion molded products were manufactured from these vinyl chloride copolymers in the same manner as in Example 2, and the matte effect, appearance, and number of fissure eyes within a 100 mm ² square were counted and are also listed in Table 5. did. The number of fish eyes was measured using the method adopted in Comparative Examples 7 to 14.

[Table] As is clear from Table 5, particles larger than the average particle size specified in the present invention have a matting effect but have a very large amount of flash and have a poor appearance, and cannot be put to practical use. The average particle size is empirically determined depending on the type of dispersant and the amount used, but in the case of polyvinyl alcohol, the larger the amount used, the smaller the particle size tends to be, and conversely, even if the amount used is too large, The number of fine particles increases, and the particles aggregate to become larger particles, and furthermore, polyvinyl alcohol is included in the polymer, which adversely affects the quality of the polymer. That is, in order to produce a molded article with good matteness and appearance as in the present invention, a vinyl chloride copolymer having a specific gel fraction and degree of swelling and an average particle size within a specific range is required. It turns out that it is necessary to select.

Claims (1)

[Scope of Claims] 1. A vinyl chloride monomer or a mixture of a vinyl chloride monomer and a comonomer copolymerizable therewith, and a compound having a plurality of active double bonds in the molecule and copolymerizable with the monomer or comonomer. Gel fraction of 3% or more obtained by reaction with compounds
A vinyl chloride resin composition comprising a vinyl chloride copolymer having a swelling degree of less than 60%, a swelling degree of 5 to 100, and an average particle size of 10 to 70μ, and other components. 2. The vinyl chloride resin composition according to claim 1, which contains a vinyl chloride homopolymer or a copolymer mainly composed of vinyl chloride as the other component. 3. The chloride according to claim 2, wherein the blending ratio of the vinyl chloride copolymer and the vinyl chloride homopolymer or the copolymer mainly composed of vinyl chloride is in the range of 1:99 to 80:20 by weight. Vinyl resin composition.