JPH0234963B2 - ENKABINIRUGURAFUTOKYOJUGOBUTSUNOSEIZOHO - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing vinyl chloride graft copolymers. More specifically, it relates to a method for producing a vinyl chloride graft copolymer that has excellent heat resistance (tensile strength at high temperatures, shape retention, heat deformation rate, rubber elasticity, and matte property) and has low fiber eye (FE). Vinyl chloride BACKGROUND ART Resins are widely used in various molding fields because they have excellent processability and the hardness can be easily and freely changed by changing the amount of plasticizer added. However, soft vinyl chloride resin made by adding a plasticizer to ordinary vinyl chloride resin has drawbacks such as poor heat resistance, poor surface matteness, and poor rubber elasticity. In order to solve the drawbacks of soft vinyl chloride resin, we have conducted extensive research to improve the ethylene content of 20 to 60% by weight, which is produced as a by-product during the production of crystalline ethylene-propylene block copolymers using Ziegler-Natsuta catalysts, and melt ind. Tsukusu (temperature 230
Discharge amount of molten resin for 10 minutes when a load of 2.16 kg is applied at It was discovered that a vinyl graft copolymer can improve the drawbacks of the above-mentioned soft vinyl chloride resin, and this was disclosed in JP-A-57-185342. However, the vinyl chloride graft copolymer produced by the production method of the example disclosed in JP-A-57-185342 has a wide particle size distribution, and in particular contains about 20% by weight of true spherical coarse particles with a particle size of 340μ or more. If the obtained graft copolymer is used as a raw material for soft vinyl chloride resin products without removing the coarse particles, a large number of FE will be generated due to the coarse particles. It is necessary to classify the coarse particles using a mesh-sized wire mesh before use, and there is a problem that about 20% by weight of the obtained graft copolymer is lost. The present inventors have conducted extensive research to solve the above-mentioned problems. As a result, by using partially saponified polyvinyl acetate and methylcellulose together as a dispersant during suspension graft copolymerization, the formation of coarse particles can be prevented and a vinyl chloride graft copolymer without the generation of FE can be produced. The present invention was completed based on the discovery that the following can be obtained. As is clear from the above description, the purpose of the present invention is to prevent the formation of coarse particles of 340 μm or more, to produce a vinyl chloride graft material that produces less FE, and has excellent heat resistance, matte surface properties, and rubber elasticity. An object of the present invention is to provide a method for producing a polymer. The present invention has the following configuration. Vinyl chloride is added to the attic polypropylene with an ethylene content of 20 to 60% by weight and a melt index of 1 to 100 g/10 min, which is produced when a crystalline ethylene-propylene block copolymer is produced using a Ziegler-Natsuta type catalyst. 1. A method for producing a vinyl chloride graft copolymer, which comprises using partially saponified polyvinyl acetate and methylcellulose as a dispersing agent in suspension graft copolymerization of monomers. The dispersant used in the present invention consists of partially saponified polyvinyl acetate and methylcellulose. The partially saponified polyvinyl acetate has a degree of saponification of 65 to 85 mol%,
The methyl cellulose has a viscosity of 4 to 60 cps as measured by a B-type viscometer at a temperature of 20°C and a 4 wt. The group content is 3 to 15 mol%, and the viscosity of a 2% by weight aqueous solution is 20 to 60 cps at a temperature of 20°C using a B-type viscometer.
belongs to. The amount of each of the partially saponified polyvinyl acetate and the methylcellulose to be used is preferably 10 to 30,000 ppm, based on the total amount of the vinyl chloride monomer and the specific atactic PP. If the amount of each used is less than 10 ppm, it is not preferable because it becomes difficult to prevent the formation of coarse particles with a particle size of 340 μ or more in the vinyl chloride graft copolymer obtained.
It is also possible to use each in an amount exceeding 30,000 ppm, but this is not preferable because the properties such as heat resistance, rubber elasticity, and surface matteness of the resulting vinyl chloride graft copolymer will deteriorate. Furthermore, the total amount of partially saponified polyvinyl acetate and methylcellulose used is 300% of the total amount of vinyl chloride monomer and specific atactic PP.
~60000ppm. If the total usage amount is less than 300ppm, it will be difficult to prevent the generation of coarse particles with a particle size of 340μ or more, and if the total usage amount is
Although it may be used in an amount exceeding 60,000 ppm, it is not preferable because the heat resistance, rubber elasticity, and surface mattness of the resulting vinyl chloride graft copolymer will deteriorate. The ratio of the amounts of the partially saponified polyvinyl acetate () and the methylcellulose () to be used is not particularly limited, but it is usually preferable that ()/() be in the range of 30/1 to 1/30. The specific atactic PP used in the present invention is
When producing a crystalline ethylene-propylene block copolymer using a Ziegler-Natsuta type catalyst, the ethylene content as a by-product is 20 to 60% by weight, with a melt index of 1 to 100 g/10 min at attack PP and a constant level. It has composition and physical properties. That is, the composition is amorphous with ethylene parts and propylene parts randomly linked together, but it shows slight crystallinity. In addition, the ethylene content is 20~
60% by weight, the remainder being propylene. Such specific atactic PP is a by-product of 10 to 20% by weight when producing a crystalline ethylene-propylene block copolymer mainly composed of propylene, and since it is dissolved in the polymerization solution, it is powdered when recovering the solvent. It can be obtained as a solid or granular material, and itself has low value as a plastic molding material. The atactic PP has an ethylene content of 20 to 60% by weight, as described above, and is particularly preferably 25 to 55% by weight. Also, the melt index is 1 to 100g/10 minutes, especially 2
~50g/10 minutes is preferred. The amount of the atactic PP used is 1 to 50% by weight,
Preferably it is 5 to 30% by weight. If the amount used is less than 1% by weight, the heat resistance, rubber elasticity, and surface matteness of the molded product when molded using the obtained vinyl chloride graft copolymer will not be sufficient;
Exceeding this is not preferable because the compatibility with ordinary vinyl chloride resins deteriorates. Examples of monomer-soluble initiators used in the suspension graft copolymerization of the present invention include radical initiators commonly used in suspension polymerization of vinyl chloride, such as lauroyl peroxide, t-butyl peroxypivalate, and diisopropyl peroxydicarbonate. , Ji(3,
5,5-trimethylhexanoyl) peroxide, bis(4-t-butylcyclohexyl) peroxydicarbonate, di3-methoxybutylperoxycarbonate, di3-methoxy-3-methylbutylperoxydicarbonate, sec- Organic peroxides such as butyl peroxydicarbonate, acetylcyclohexylsulfonyl peroxide, α,α′-azobis-2,4-dimethylvaleronitrile, α,α′-azobis-4-methoxy-2,4-dimethylvalero Radical initiators include azo compounds such as nitrile, α,α'-azobisisobutyronitrile, and mixtures of two or more thereof. Further, the timing of adding the radical initiator is not particularly limited, and it may be added immediately after charging water and a dispersant into the polymerization vessel, or after the temperature inside the polymerization vessel has been raised to a predetermined polymerization temperature. May be added. As a method for producing the vinyl chloride graft copolymer of the present invention, for example, a predetermined amount of water, a dispersant, a specific attic PP, and a vinyl chloride monomer are charged into a polymerization vessel, and the temperature inside the polymerization vessel is maintained at 50 to 60°C. Warm up 5
After dissolving a specific atactic PP in vinyl chloride monomer while stirring for ~7 hours, a predetermined amount of a radical initiator is added to carry out graft copolymerization. Alternatively, a predetermined amount of water and a specific Atactic PP and vinyl chloride monomer are charged, the inside of the polymerization vessel is heated to 50-60℃, stirred for 5-7 hours, specific atactic PP is dissolved in vinyl chloride monomer, and then a predetermined amount is dispersed. Examples include a method of graft copolymerization by adding a radical initiator and a radical initiator. In addition, the polymerization temperature during graft copolymerization is
Temperatures within the range of 20-80°C are preferred. When the temperature at which atactic PP is dissolved in the vinyl chloride monomer is higher than the polymerization temperature for the above-mentioned graft copolymerization, the interior of the polymerization vessel is cooled after dissolution, and then the temperature is raised to a predetermined polymerization temperature to form radicals. It is necessary to add an initiator to initiate the graft copolymerization. In the production method of the present invention, a PH regulator, a chain transfer agent, etc. can be used as necessary, and a polymerization inhibitor can also be added to the slurry in the polymerization vessel after the graft copolymerization is completed. Furthermore, trace amounts of inorganic substances may be added to the polymerization vessel within a range that does not impede the effects of the present invention. The vinyl chloride graft copolymer obtained by the production method of the present invention does not contain coarse particles of 340μ or more, and therefore, a soft vinyl chloride resin composition in which a plasticizer is blended with the graft copolymer. When molded using
Molded products with excellent heat resistance, rubber elasticity, and surface matte properties can be obtained, and can be suitably used in various fields. The present invention will be specifically described below based on Examples and Comparative Examples. The various measuring methods used in Examples and Comparative Examples were as follows. (1) Particle size distribution Using a Tyler standard sieve, the sample was sieved for 10 minutes using a rotor-type vibrating sieve machine, the particle size distribution was measured, and the pass rate was expressed in weight %. (2) Measurement of FE Add 50 parts by weight of DOP, 5 parts by weight of tribasic lead sulfate, and 1 part by weight of lead stearate to 100 parts by weight of the test resin. After mixing, the mixture was heated at a temperature of 170°C.
Knead for 7 minutes using 6-inch rolls with a roll spacing of 0.3 mm, and then pull out a sheet with a thickness of 0.1 mm. Count the number of FEs per ^1000cm2 of this sheet and calculate the FE
It was made into a number. (3) Measurement of tensile strength, 100% modulus, and elongation Measured in accordance with JIS K-6723. (4) Measurement of heating deformation rate Measured in accordance with JIS K-6723. (5) Measurement of hardness, compression set, and impact resilience Measured in accordance with JIS K-6301. (6) Measurement of surface gloss A belt-shaped extruded product having a length of 20 mm, a width of 20 mm, and a thickness of 2 mm was used as a test piece, and the surface of the test piece was visually observed and evaluated according to the following criteria. ◎: Surface lacks luster. ○: Slight gloss on the surface. △: Poor surface gloss. ×: Glossy surface. (7) Measurement of surface unevenness A belt-shaped extruded product having a length of 20 mm, a width of 20 mm, and a thickness of 2 mm was used as a test piece, and the surface of the test piece was visually observed and evaluated according to the following criteria. ◎: No surface unevenness. ○: Slight surface unevenness. △: Slight surface unevenness. ×: Surface unevenness. (8) Shape retention A belt-shaped extruded product with a length of 20 mm, a width of 20 mm, and a thickness of 2 mm was used as a test piece, and three of the test pieces were placed in a gear open at temperatures of 190°C, 200°C, and 210°C, respectively. They were placed one by one, left for 10 minutes, and evaluated based on the shape according to the following criteria. ◎: The test piece is the same as the original piece. 〇: The test piece slightly melted and the length increased by 50% or less from the original length. △: The test piece is melted, and the length is 51 to 150 compared to the original piece.
% length increased. ×: The test piece melts and increases by 151% or more from the length of the original piece. Examples 1 to 8, Comparative Examples 1 to 4 As Examples 1 to 8, an ethylene content of 30% by weight and a melt index of 10 were placed in a polymerization vessel with an internal volume of 200.
g/10 min specific attack PP 6.2Kg, water
Add 100Kg and 62Kg of vinyl chloride monomer and heat to 60℃.
The mixture was stirred for 5 hours to dissolve the above-mentioned atactic PP in the vinyl chloride monomer. Temperature inside polymerization vessel is 30℃
After cooling, stirring was stopped, and an aqueous solution containing predetermined amounts of partially saponified polyvinyl acetate and methyl cellulose listed in Table 1 below as a dispersant was added into the polymerization vessel, and then a radical initiator diisopropyl peroxydi 6.5 g of carbonate was added and suspension graft copolymerization was carried out at a polymerization temperature of 40° C. for 11 hours. The obtained product was filtered and dried to obtain a white granular graft copolymer. In addition, as Comparative Examples 1 to 4, suspension graft copolymerization was carried out in accordance with Examples 1 to 8, except that an aqueous solution containing a predetermined amount of polyvinyl acetate listed in Table 1 below was used. The resulting product was filtered and dried to obtain a white granular graft copolymer. Particle size distribution and FE were measured using the graft copolymers obtained in each of the Examples and Comparative Examples. These results are summarized in Table 1. (Note) Partially saponified polyvinyl acetate A: Nippon Gosei Kagaku Kogyo Co., Ltd. KH-20 Partially saponified polyvinyl acetate B: Nippon Gosei Kagaku Kogyo Co., Ltd. KH-17 Partially saponified polyvinyl acetate C: Nippon Gosei Kagaku Kogyo Co., Ltd. Co., Ltd. KP-08 Partially saponified polyvinyl acetate D: Kuraray Co., Ltd. L-9 Cellulose A: Matsumoto Yushi Pharmaceutical Co., Ltd. 65MP-50 Cellulose B: Matsumoto Yushi Pharmaceutical Co., Ltd. 60MP-50 Comparative example 5 to 8 The graft copolymers obtained in Comparative Examples 1 to 4 were sieved using a Tyler standard sieve with a 42-mesh sieve, and only the 42-mesh pass product was fractionated, and the obtained graft copolymers were used to conduct FE. The results are summarized in Table 1 as Comparative Examples 5 to 8, respectively. Comparative Examples 9 to 20 As Comparative Examples 9 to 20, Comparative Examples 9 to 16 use only an aqueous solution containing a predetermined amount of partially saponified polyvinyl acetate listed in Table 2 below as a dispersant, and Comparative Examples 17 to 20
carried out suspension graft copolymerization according to Examples 1 to 8, except that only an aqueous solution containing a predetermined amount of methylcellulose listed in Table 2 below was used as a dispersant, and the resulting product was , and dried to obtain a white granular graft copolymer. Particle size distribution and FE measurements were performed using the graft copolymers obtained in each comparative example. The results are summarized and shown in Table 2.

【table】

【table】

【table】

[Table] Examples 9 to 19 As Examples 9 to 19, Example 1 except that aqueous solutions containing predetermined amounts of partially saponified polyvinyl acetate and methylcellulose listed in Table 3 below were used.
Suspension graft copolymerization was carried out in accordance with 8 to 8, and the resulting product was filtered and dried to obtain a white granular graft copolymer. The particle size distribution and FE of the graft copolymers obtained in each example were measured, and the results are summarized in Table 3. Examples 20 to 23 and Comparative Examples 21 to 22 A specific atactic PP containing 30% by weight of ethylene and a melt index of 10 g/10 minutes as shown in Table 4 below was added to a polymerization vessel having an internal volume of 200 ml. Add vinyl chloride monomer and 100 kg of water, and
℃, stirred for 5 hours, and then
After dissolving PP in vinyl chloride monomer, it was cooled to 30℃, stirring was stopped, and the degree of saponification was determined by dissolving PP in vinyl chloride monomer.
Partially saponified polyvinyl acetate 50 with 69 mol%, viscosity 6 cps
g and methylcellulose with a methoxy group content of 28 mol% and a hydroxypropoxy group content of 6 mol%
An aqueous solution containing 50 g of diisopropyl peroxydicarbonate was added into the polymerization vessel, and then 6.5 g of diisopropyl peroxydicarbonate was added as a radical initiator, and the polymerization temperature was increased to 40°C.
Suspension graft copolymerization was carried out for 11 hours, and the resulting product was filtered and dried to obtain a white granular graft copolymer. In addition, as Comparative Examples 21 to 22, specific atactic PP and vinyl chloride monomer in the amounts listed in Table 4 below, and 100 kg of water were charged into a polymerization vessel with an internal volume of 200℃, and the inside of the polymerization vessel was heated to 60°C. After heating and stirring for 5 hours to dissolve the above-mentioned specific atactic PP in the vinyl chloride monomer, the temperature inside the polymerization vessel was increased to 30°C.
After cooling, stirring was stopped and partially saponified polyvinyl acetate with a degree of saponification of 69 mol% and a viscosity of 6 cps was added as a dispersant.
An aqueous solution containing 50 g of diisopropyl peroxydicarbonate was added into the polymerization vessel, and then 6.5 g of diisopropyl peroxydicarbonate was added to carry out suspension graft copolymerization according to Examples 20 to 23. After drying, a white granular graft copolymer was obtained. 10 each of the graft copolymers obtained in each example and each comparative example
Kg, calcium-zinc stabilizer 0.2Kg, calcium carbonate 4Kg, pigment (carbon black) 0.2Kg
Add and heat at 80℃ using a Henschel mixer (trade name).
The mixture was stirred and mixed for 10 minutes, then 10 kg of di-2-ethylhexyl phthalate (DOP) was added, and the mixture was stirred and mixed at 130°C for 15 minutes. The mixture was heated to a width of 20 mm and a thickness of 2 using a single screw extruder with a diameter of 40 mm (L/D = 22, compression ratio 3.5).
A belt-shaped molded product of mm was extruded. Using the obtained belt-shaped molded product, test pieces for various measurements were prepared, and the surface state was observed and various physical properties were measured. The results are summarized in Table 4.

【table】

【table】

【table】

[Table] As is clear from Tables 1 and 2, the graft copolymer obtained by the production method of the present invention using partially saponified polyvinyl acetate and methylcellulose as dispersants has a diameter of 340μ or more (42 mesh units). )
It can be seen that a good molded product with no generation of coarse particles and an extremely small number of FEs can be obtained. On the other hand, in the graft copolymers obtained in Comparative Examples 1 to 4 in which only partially saponified polyvinyl acetate was used as a dispersant, formation of 42 mesh products of around 20% by weight, that is, coarse particles of 340μ or more, was observed.
Moreover, only molded products with an extremely large number of FEs could be obtained. In Comparative Examples 5 to 4, the graft copolymers obtained in Comparative Examples 1 to 4 were sieved through a 42-mesh sieve, and FE was measured using only the 42-mesh pass product.
Looking at the results of 4, compared to Comparative Examples 1 to 4, the FE
It can be seen that although the number of FEs is decreased, the number of FEs is considerably larger than that of those obtained in Examples 1 to 8. In addition, as is clear from Table 3, the ratio of partially saponified polyvinyl acetate/methyl cellulose was reduced to 1/30.
The graft copolymers obtained in Examples 9 to 15, which were changed to ~30/1, had a particle size of 42 mesh products.
No generation of coarse particles larger than 340μ was observed.
It can also be seen that the FE is also extremely good. Also,
The ratio of the partially saponified polyvinyl acetate/methylcellulose used was fixed at 1, and the total amount of the partially saponified polyvinyl acetate and methylcellulose used was 600 ppm.
It can be seen that the graft copolymers obtained in Examples 16 to 19 in which the values were changed to 2,000 ppm, 10,000 ppm, and 30,000 ppm also had no generation of coarse particles of 42 mesh units and had extremely good FE. As is clear from Table 4, the molded products using the graft copolymer obtained by the production method of the present invention have excellent surface conditions such as surface gloss and surface unevenness, and have excellent heat deformation rate and shape. It can be seen that heat resistance such as retention is also excellent. As described above, the graft copolymer obtained by the production method of the present invention does not contain coarse particles, has extremely good FE even when used as is, and has excellent surface matte properties, heat resistance, rubber elasticity, etc. It was found that it gave an excellent molded product.

Claims (1)

[Claims] 1. Ethylene content as a by-product when producing a crystalline ethylene-propylene block copolymer using a Ziegler-Natsuta type catalyst: 20 to 60% by weight, melt index: 1 to 100 g/10 min. A method for producing a vinyl chloride graft copolymer, which comprises using partially saponified polyvinyl acetate and methylcellulose together as a dispersant in suspension graft copolymerization of a vinyl chloride monomer to atactic polypropylene. . 2 As partially saponified polyvinyl acetate, viscosity 4~
The method for producing a vinyl chloride graft copolymer according to claim 1, which uses partially saponified polyvinyl acetate having a saponification degree of 60 cps and a saponification degree of 65 to 85 mol%. 3 As methylcellulose, viscosity 20-60cps,
The method for producing a vinyl chloride graft copolymer according to claim 1, using methylcellulose having a methoxy group content of 25 to 33 mol% and a hydroxypropoxy group content of 3 to 15 mol%. 4 Atactic polypropylene with an ethylene content of 20 to 60% by weight and a melt index of 1 to 100 g/10 min, which is a by-product when producing a crystalline ethylene-propylene block copolymer using a Ziegler-Natsuta type catalyst, 1 to 50 Vinyl chloride monomer 99% by weight
2. The method for producing a vinyl chloride graft copolymer according to claim 1 or 2, wherein 50% by weight of the vinyl chloride graft copolymer is graft copolymerized.