JPS6227451A - Production of vinyl chloride polymer - Google Patents

Abstract

PURPOSE:To improve the electrical insulating properties of a polymer inexpensively and efficiently, by adding a specified quantity of a single poly-saccharide to a polym. mixture and carrying out a polymn. reaction in polymerizing vinyl chloride monomer in an aq. medium. CONSTITUTION:A vinyl monomer, a dispersant, an emulsifier, a polynm, initiator (e.g. benzoyl peroxide), etc. are added to an eq. medium and polymerized by suspension polymn. or emulsion polymn. A single polysaccharide is added to the polymn. mixture before, during or after polymn, in such an amount that the resulting polymer contains 10-5,000ppm of the polysaccharide, tus obtaining the desired vinyl chloride polymer. Examples of the polysaccharides are ethylcellulose, starch, glycogen, beta-cyclodextrin, inulin, galactan and pectin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a vinyl chloride polymer with improved electrical insulation properties.

[Prior Art] Vinyl chloride polymers (hereinafter abbreviated as PVC) originally have electrical insulation properties, that is, volume resistivity (hereinafter abbreviated as VR).
It is a plastic with a large amount of ω and is used as an electrical insulating material, but it has a relatively high tendency to ionize, such as in the purification process of vinyl chloride monomer, which is the raw material for PVC, and in the manufacturing process and processing of PVC. It is said that when metal compounds are mixed in, the VR of l) V C is lowered by these metal ions.

However, it is extremely difficult to completely avoid the contamination of these metal ions, etc., which requires a great deal of cost and is virtually impossible.

In order to solve this problem, a substance that supplements the metal ions mentioned above and eliminates their conductivity has been used: PV
A method of incorporating it into C has been proposed.

For example, methods of adding clay or calcium carbonate are known, but these have the disadvantage of being less effective or deteriorating other properties of the product.

As methods for improving these, JP-A-56-81351 and JP-A-56-141336 disclose a method of adding carboxylic acids, a method of adding carboxylic acids, and a method of adding carboxylic acids, qSi model S6-1.
59242 or JP-A-57-119944 describes a method of adding vinyl ether or a copolymer of styrene and maleic anhydride, and JP-A-57-179.
No. 235 discloses a method of adding xanthan gum, and JP-A-59-152942 discloses a method of adding polyvinylpyrrolidone.
Japanese Patent No. 56646 discloses a method of adding carbohydrates such as monosaccharides or polysaccharides during processing and molding of PVC. However, when using these methods, for example, the polymerization rate decreases, the action of the suspension stabilizer is adversely affected, and the VR improvement effect varies, and PVC silk compositions with uniform properties are There are many disadvantages to improvement, such as not having it or adding it to the polysaccharide when adding it during processing and molding.

[Problems to be Solved by the Invention] As a result of intensive research in order to solve these drawbacks, the present inventors have found that a specific amount of a single polysaccharide is added in the PvC polymerization process.
The present invention was completed by discovering that the VR of the PVC composition obtained could be improved by doing so.

[Means for Solving the Problems] That is, the present invention provides, when a vinyl chloride monomer is polymerized in an aqueous medium, a monomer is polysaccharide y1°l, its content ω
The method for producing a vinyl chloride polymer includes the steps of: adding the polyvinyl chloride polymer so that the amount of polyvinyl chloride is 10 pI) rTT or more and less than 5000 ppm.

In the present invention, PVC refers to not only vinyl chloride homopolymers but also ethylene, propylene, vinyl acetate, vinyl propionate, acrylic acid, acrylic esters, vinyl ethers, and various other known copolymerizable monomers. The present invention includes copolymers of vinyl chloride and graft copolymers mainly composed of vinyl chloride, and in the present invention, any one of known polymerization methods such as suspension polymerization, emulsion polymerization, bulk polymerization, and gas phase polymerization can be used. Can be applied.

The single polysaccharide used in the present invention is a carbohydrate produced by dehydration and condensation of two or more molecules of monosaccharides through glycosidic bonds, rather than multiple components, and is a purified product synthesized naturally in living organisms. It is obtained by denaturing or denaturing.

Typical single polysaccharides include cellulose, starch,
Glycogen, caronine, dextran.

Dekis [~phosphorus or siphlovkis] herin, inulin, levan, mannan, galactan.

Pectin, chitin, hemicellulose, lichenin, etc. can be used, and artificially modified versions of these single polysaccharides can also be used.

Furthermore, these can be used alone or in combination of two or more.

The larger the amount of single polysaccharide added, the greater the VR improvement effect, but it has a 5.5% effect on PvC. Even if more than OOOppm is added, the VR improvement effect is not as high as expected and is not practical. Further, if the amount is less than ioppm, the VR improvement effect is small.

In addition, in normal production of PvC, the monomer addition rate in the polymerization process is about 85 to 90%, so the amount of single polysaccharide added during polymerization is 8% to the vinyl chloride monomer. .5 ppm or more and less than 4500 ppm is appropriate.

In the present invention, a single polysaccharide is added to a PVC polymerization system, and the addition timing is within the polymerization process, such as before, during, or at the end of PVC polymerization, and during the drying process of the polymer. It may be done in any of the steps before starting the process. A greater VR improvement effect can be obtained with the same addition amount by adding it during the polymerization process of the present invention than by the conventional method of adding it during molding.

In addition, when adding this single polysaccharide during the polymerization process, there are particular limitations on the polymerization recipe (such as dispersants, emulsifiers, initiators, etc. that are commonly used in suspension polymerization and emulsion polymerization, etc.). can be used.

For example, as a dispersant and an emulsifier, poly 1ffi+M
Protective colloidal compounds such as partially saponified vinyl, acrylic acid copolymers, cellulose derivatives, gelatin, starch, etc., esters of higher fatty acids and polyhydric alcohols, anionic surfactants such as polyoxyethylene derivatives, high grade Anionic surfactants such as metal salts of fatty acids and metal salts of alkylbenzenesulfonic acids are used.

Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, lauroyl peroxide, dioctyl peroxydicarbonate, and t-butylbyronitrile sibibarate, azo compounds such as azobisisodimethylvaleronitrile, and potassium persulfate.

Persulfates such as ammonium persulfate are used.

Moreover, the polymerization humidity is carried out within the commonly used range of 30 to 80°C.

Furthermore, PVC obtained by adding a single polysaccharide to the chassis
When molding and processing, plasticizers, stabilizers, fillers, ultraviolet absorbers, colorants, pigments, lubricants, etc. are blended and mixed uniformly according to the usual method, and before extrusion molding, calender rolls, injection molding machines, etc. It can be molded by

Moreover, there is no problem even if a single polysaccharide is further added during the molding process.

[Effect of the invention 1] The present invention is a method of adding a single polysaccharide to the polymerization system during the production of a vinyl chloride polymer, and compared to conventional methods, high electrical insulation properties can be obtained with a small amount of addition. .

"Examples" The present invention will be specifically explained below with reference to Examples.
This is not intended to limit the scope of the invention.

Note that the parts in the examples are important parts.

[Comparative Example 1] In a polymerization vessel with an internal volume of 1N2, 250 parts of pure water, 0.25 parts of partially saponified poly 1M vinyl, 2,2--azobis-2,
After charging 0.5 part of 4-dimethylvaleronitrile, 100 parts of vinyl chloride single-hinged bodies were injected under reduced pressure.

Next, the mixture was heated to 57° C. with stirring, and when the pressure inside the polymerization vessel decreased by 2 kg/CIi from the pressure in the steady state of the polymerization reaction, recovery of unreacted monomers was started. The polymerization time at this time was 10 hours.

After collecting the unreacted monomers, the polymerization suspension was taken out from the polymerization vessel, dehydrated and dried, and the suspension of the Φ synthesis product was measured, and a polymerization conversion rate of about 85% was obtained.

50 parts of dioctyl phthalate (DOP) and 5 parts of tribasic lead sulfate were mixed with 100 parts of the product thus obtained, and after kneading for 10 minutes with a roll heated to 150°C, the mixture was kneaded at 170°C. Create a sheet with a thickness of about 1.0 mm by pressing for 5 minutes, and transfer the VR@ of this sheet 1 to JIS-
When measured using a method according to 6723, the values shown in Table 1 were obtained.

[Example 1] Into the same 182 polymerization vessel as in Comparative Example 1, 250 parts of pure water, 0.25 part of partially saponified polyvinyl acetate, 0.05 part of 2,2'-azobis-2,4dimethylvaleronitrile, and ethoxy Ethylcellulose 0.00 with a content of 47-49% and a degree of ethoxy substitution per anhydroglucose of 2.4-2.5
After charging 5 parts, Jg vinyl monolayer 10 was added under reduced pressure.
0 parts were injected. Next, a polymerization reaction and dehydration drying were performed in the same manner as in Comparative Example 1, and the polymerization time was 10 hours, and the polymerization conversion rate was about 85%. Furthermore, when VR was measured using this product in the same manner as in Comparative Example 1, the values shown in Table 1 were obtained, indicating an improvement in VR.

[Example 2] In the formulation of Example 1, the amount of ethyl cellulose added was increased to 0.03 parts, a polymerization reaction was carried out in the same manner as in Comparative Example 1, post-treatment was performed, and VR was measured.

As a result, the polymerization time was 10 hours, and the polymerization conversion rate was approximately 85%.
As a result, the VR value was as shown in Table 1/Z results, and a significant improvement in VR was recognized.

[Example 31 The polymerization reaction was started in the same manner as in Comparative Example 1, and 3
When the time elapsed, 0.03 part of ethyl cellulose used in Example 1 was added as a 5 tu [%] acetone solution.

Thereafter, the polymerization reaction was continued in the same manner as in Comparative Example 1, post-treatment was performed, and VR was measured.

As a result, the polymerization time was 10 hours, and the polymerization conversion rate was approximately 85%.
Therefore, the VR values were as shown in Table 1, and a significant improvement in VR was observed, but this was not the case for the culms of Example 2.

[Example 4] A polymerization reaction was carried out in the same manner as in Comparative Example 1, and immediately before recovering the unreacted monomer at the end of the reaction, 0.05 part of the ethyl cellulose used in Comparative Example 1 was added to 5% acetic acid. Add as a solution. After collecting unreacted monomers, the polymer suspension was taken out from the polymerization vessel, dehydrated and dried, and VR was measured in the same manner as in Comparative Example 1.

As a result, the polymerization time was 10 hours, and the polymerization conversion rate was approximately 85%.
Therefore, the VR value was as shown in Table 1, and an improvement in VR almost equivalent to that of Example 3 was observed.

Comparative Example 21 A polymerization reaction was carried out in the same manner as in Example 1 except that the amount of ethyl cellulose added was reduced to 0.0005 parts in the formulation of Example 1, post-treatment was performed, and VR was measured.

As a result, the polymerization time was 10 hours, and the polymerization conversion rate was approximately 85%.
Therefore, the VR values were as shown in Table 1, and almost no improvement in VR was observed.

[Comparative Example 3.4] For 100 parts of PVC obtained in Comparative Example 1, r)OR
14 parts, 5 parts of trivalent lead sulfate, and 0.05 parts and 0.5 parts of the ethyl cellulose used in Example 1 were added, mixed well, and heated with a roll heated to 150'C for 10 minutes. The kneaded material was pressed at 170°C for 5 minutes to create a sheet with a thickness of about 1.0M, and the VR of this sheet was
When the value was measured in accordance with JIS-6723, the values were as shown in Table 1, and it was confirmed that the VR improvement effect was confirmed when 0.5 part was added, but when added during polymerization To obtain the same effect, approximately 10 times more I heat was required. Furthermore, when the amount of m added was 0.05 part, there was almost no effect of improving VR.

[Example 5] In the formulation of Example 1, β was used instead of ethyl cellulose.
-0.005 part of cyclodextrin to phosphorus was added, a polymerization reaction was carried out in the same manner as in Comparative Example 1, post-treatment was carried out, and VR was measured. As a result, the polymerization time was 10 hours, the polymerization conversion rate was approximately 85%, and the VR values are shown in Table 2. The results were uniform, and an improvement in VR was observed.

[Example 6] In the formulation of Example 5, β-cyclodextrin was added to 0.
．． A polymerization reaction was performed in the same manner as in Comparative Example 1 by increasing the amount to 0.3 parts, post-treatment was performed, and VR was measured. As a result, the polymerization time was 10 hours, the polymerization conversion rate was about 85%, and the VR values were as shown in Table 2, and a significant improvement in VR was recognized.

[Example 7] Polymerization reaction was started in the same manner as in Example 3, and 3 hours after the start of polymerization, 0.03 part of β-cycloaxtrin used in Example 5 was added to 5% acetate. It was added as a solution. Then, the polymerization reaction was continued as in Comparative Example 1,
Post-processing was performed and VR was measured.

As a result, the polymerization time was 10RI7! I. The polymerization conversion rate was approximately 85%, and the VR value was as shown in Table 2.
Although an improvement in VR was observed, this was not the case in Example 6.

[Example 8] After the polymerization reaction in the same manner as in Example 4, immediately before collecting the unreacted monomer, β-cyclodex-1-phosphorus 0.0% used in Example 5 was added.
0.05 parts was added as a 5 wt % acetone solution.

And no response! After collecting the J1ω body, the polymer suspension was taken out from the polymerization vessel, dehydrated and dried, and VR was measured in the same manner as in Comparative Example 1.

As a result, the polymerization conversion rate was approximately 85 at a time of 10 hours.
%, and the VR value was as shown in Table 2, and an improvement in VR almost equivalent to that of Example 7 was observed.

[Comparative Example 5] In the treatment of Example 5, a polymerization reaction was performed in the same manner as in Example 5 except that the addition M of β-cyclodextrin was reduced to 0.0005 parts, post-treatment was performed, and VR was measured. .

As a result, the polymerization time was 10 hours, and the polymerization conversion rate was approximately 85%.
Therefore, the VR values were as shown in Table 2, and almost no improvement in VR was observed.

[Comparative Example 6.71 Comparative Example 3 In the same manner as in Onibi 4, 0.05 parts of β-cyclodex 1-herin used in Example 5 was added in place of ethyl cellulose during blending before roll kneading, and
Add 0.5 part of each, mix well, roll for 10 minutes with a roll heated to 150'C, press for 5 minutes at 170°C to create a sheet with a thickness of about 1.0#, and this sheet When the VRfiI'i of was measured in accordance with J Is-6723, the values were as shown in Table 2.
An improvement effect on VR was confirmed when 0.5 part was added, but
To obtain the same effect as when added during polymerization, approximately io@
I needed a prisoner above a.

Further, when the amount of addition (2) was 0.05 part, there was almost no effect of improving VR.

Table-1 Table-2

Claims (1)

[Claims] (1) When a vinyl chloride monomer is polymerized in an aqueous medium, a single polysaccharide is added to the vinyl chloride polymer obtained after polymerization during the polymerization process so that the content thereof is 10 ppm or more and 50 ppm or more.
A method for producing a vinyl chloride polymer, which comprises adding the vinyl chloride polymer in an amount of less than 0.00 ppm.