JP2002030111A - Method for producing chlorinated vinyl chloride resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a chlorinated vinyl chloride resin within a shortened chlorination time in excellent productivity without sacrificing the hue and heat stability of the obtained resin during processing by chlorinating a special vinyl chloride resin in an aqueous suspension. SOLUTION: A chlorinated vinyl chloride resin is produced by the chlorination of a vinyl chloride resin in an aqueous suspension, wherein the vinyl chloride resin used is substantially free from an antioxidant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a chlorinated vinyl chloride resin, and more particularly, to a method for chlorinating a vinyl chloride resin in an aqueous suspension, in which the color tone and heat stability during processing are reduced. The present invention relates to a method for producing a chlorinated vinyl chloride-based resin having a short chlorination reaction time and excellent productivity without sacrificing.

[0002]

2. Description of the Related Art Chlorinated vinyl chloride resins have the property of increasing the softening temperature of vinyl chloride resins, and are produced by chlorinating vinyl chloride resins in aqueous suspension.

[0003] The vinyl chloride resin as a raw material resin of the chlorinated vinyl chloride resin is a homopolymer of vinyl chloride or a monomer copolymerizable with vinyl chloride (eg, ethylene, propylene, vinyl acetate). , Allyl chloride, allyl glycidyl ether, acrylate, vinyl ether, etc.). The resin is obtained by partially saponifying these monomers with polyvinyl alcohol, methylcellulose, hydroxypropylmethylcellulose, a dispersant such as polyethylene oxide and lauroyl peroxide, di-2-ethylhexylperoxy neodecanoate, t-butylperoxy. Neodecanoate, α, α '
-Polymerized using an oil-soluble polymerization initiator such as azobis-2,4-dimethylvaleronitrile, and further added with an antioxidant to improve the initial coloration and thermal stability of the obtained vinyl chloride resin, It is generally polymerized by a suspension polymerization method.

In general, chlorinated vinyl chloride resins are generally chlorinated by supplying chlorine gas to the above-mentioned vinyl chloride resin in an aqueous suspension and irradiating with a mercury lamp or adding a catalyst.

[0005] Attempts have been made to improve the productivity of chlorinated vinyl chloride resins by shortening the reaction time of the chlorination reaction. For example, increasing the chlorination reaction temperature shortens the chlorination reaction time. Further, the chlorination reaction time can be shortened by increasing the amount of the irradiated mercury lamp. Further, there is an attempt to improve productivity by optimizing the resin concentration at the start of the chlorination reaction to 20 to 35% by weight from the viewpoint of increasing the charged amount, thereby balancing the charged amount and the reaction rate. However, any of these methods is not preferable because it deteriorates initial coloring and thermal stability during processing of the chlorinated vinyl chloride resin.

[0006]

The object of the present invention is to chlorinate a vinyl chloride resin in an aqueous suspension to produce a chlorinated vinyl chloride resin without sacrificing initial colorability and thermal stability during processing. Instead, it is intended to provide a method for producing a chlorinated vinyl chloride-based resin which shortens the chlorination reaction time and improves productivity.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies focusing on vinyl chloride resin which is a raw material resin of chlorinated vinyl chloride resin, and as a result, have found that vinyl chloride containing substantially no antioxidant. Unexpectedly, when the system resin was used, it was found that the initial coloring property and thermal stability during processing could be maintained, and the chlorination reaction time could be shortened, and the present invention was completed.

That is, the present invention provides (1) a method for producing a chlorinated vinyl chloride resin, which comprises chlorinating a vinyl chloride resin containing substantially no antioxidant in an aqueous suspension. Item 1), (2) The method for producing a chlorinated vinyl chloride resin according to claim 1 wherein the chlorination is performed using a mercury lamp (Claim 2), and 3. The method for producing a chlorinated vinyl chloride resin according to claim 1 or claim 2, wherein the vinyl chloride resin contains 0.01% by weight or less of an antioxidant. 3. The method for producing a chlorinated vinyl chloride resin according to claim 1 or 2, which contains an oxidizing agent (claim 4).
4. A vinyl chloride resin obtained by suspension polymerization using at least one dispersant selected from partially saponified polyvinyl alcohol, hydroxypropyl methylcellulose, and polyethylene oxide.
Or the method for producing a chlorinated vinyl chloride resin according to 4.
(5), and (6) under aqueous suspension of vinyl chloride resin, 20 to 20
The method for producing a chlorinated vinyl chloride-based resin according to claim 1, wherein the chlorination is performed at a resin concentration of 35% by weight.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The vinyl chloride resin in the present invention is a homopolymer of vinyl chloride or a monomer copolymerizable with vinyl chloride (eg, ethylene, propylene, vinyl acetate, allyl chloride, Allyl glycidyl ether, acrylic acid ester, vinyl ether, etc.). These monomers are partially saponified with polyvinyl alcohol, methylcellulose, hydroxypropylmethylcellulose, a dispersant such as polyethylene oxide and lauroyl peroxide, di-2-ethylhexylperoxy neodecanoate, t-butyl peroxy neodecanoate. , Α, α'-azobis-2,4-dimethylvaleronitrile and the like, and are polymerized by suspension polymerization using an oil-soluble polymerization initiator.

The present invention is characterized in that the vinyl chloride resin contains substantially no antioxidant. Here, a vinyl chloride resin containing substantially no antioxidant is used as an additive for suspension polymerization or in an after-treatment, where no antioxidant is added, or an antioxidant is added in these steps. In this case, the content of the antioxidant is 0.01% by weight or less, preferably 0.005% by weight, more preferably 0.003% by weight based on the dry weight of the obtained vinyl chloride resin.
The vinyl chloride resins produced below are shown. The antioxidant referred to in the present invention is generally used for improving the initial coloring and thermal stability of the vinyl chloride resin, and is usually 0.015 to 0.035% by weight based on the vinyl chloride resin. Antioxidants used to some extent, for example, butylhydroxyanisole (BHA), 3,5-ditert-butyl-4-hydroxytoluene (BHT), or Irganox 245, Irg manufactured by Ciba Geigy.
hindered phenolic antioxidants such as anox 1076, Irganox 1010, p-produced by Wako Pure Chemical Industries, Ltd.
Quinone antioxidants such as benzoquinone and TBHQ; aromatic amine antioxidants such as phenylenediamine manufactured by Wako Pure Chemical Industries; sulfur compound antioxidants such as mercaptan and dithiocarbamate manufactured by Wako Pure Chemical Co .; Clopen-based antioxidants such as Q-1300 manufactured by Yakuhin are known.

In the present invention, it is desirable to obtain a chlorinated vinyl chloride resin by chlorinating the thus obtained vinyl chloride resin at a resin concentration of 20 to 35% by weight under aqueous suspension. There is no particular limitation on the chlorination reaction, a chlorination method of irradiating with a mercury lamp, a method of chlorination using a catalyst,
Furthermore, the combination is possible. In particular, a chlorination method of irradiating with a mercury lamp is preferred from the viewpoint of improving thermal stability.

[0012]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, parts and percentages are by weight unless otherwise specified.

Incidentally, initial coloring in Examples and Comparative Examples,
The method for measuring or evaluating the thermal stability and the Vicat softening point is as follows. (A) Initial coloring 3 m obtained by pressing a sheet obtained by kneading at 195 ° C. for 3 minutes with an 8-inch roll for 10 minutes at 200 ° C.
A plate having a thickness of m was visually judged. (B) Thermal stability A sheet obtained by kneading at 195 ° C. for 3 minutes with an 8-inch roll was cut into a length of 3 cm and a width of 5 cm, and the time for blackening after heating in a 200 ° C. oven was measured. (C) Vicat softening point According to JIS K 6766. However, the load was 5 kg.

Example 1 A stainless steel autoclave equipped with stirring blades was charged with 120 parts of ion-exchanged water and 0.08 parts of water.
Parts of polyvinyl alcohol (degree of saponification: 79.5 mol%,
A 4% strength aqueous solution at 20 ° C .: 41.0 CPS) and 0.04 part of an oil-soluble polymerization initiator t-butyl peroxy neodecanoate were charged, and the inside of the autoclave was degassed under vacuum and then 100 parts. Of vinyl chloride. afterwards,
Polymerization was carried out at 58 ° C. for 5 hours under stirring, and after a post-treatment and a drying step, a vinyl chloride resin was obtained. The polymerization degree of this vinyl chloride resin was 1,000.

Into the reactor, 230 parts of pure water and 100 parts of a vinyl chloride resin are charged, vacuum degassing and nitrogen replacement are carried out with stirring, and after chlorine degassing, chlorine gas is blown into the reactor.
A chlorination reaction was performed at 85 ° C. by irradiation with a high-pressure mercury lamp of watts. When the chlorine content reached 67%, the irradiation of the mercury lamp was stopped to stop the chlorination reaction. The reaction time is 3.
It was eight hours. After expelling unreacted chlorine with nitrogen, the remaining hydrochloric acid was removed by washing with water and dried to obtain a chlorinated vinyl chloride resin.

The chlorinated vinyl chloride resin 1 obtained above
10 parts by weight of B31 (MBS resin manufactured by Kanegafuchi Chemical Industry Co., Ltd.), 2 parts by weight of a tin-based stabilizer,
1.7 parts of lubricant are blended, rolled and pressed,
Physical properties were evaluated. Table 1 shows the evaluation results.

Example 2 In a stainless steel autoclave equipped with a stirring blade, 120 parts of ion-exchanged water and 0.08
Parts of polyvinyl alcohol (degree of saponification: 79.5 mol%,
Viscosity of a 4% aqueous solution at 20 ° C .: 41.0 CPS) and 0.04 part of an oil-soluble polymerization initiator t-butylperoxyneodecanoate and 3,5-ditert-butyl-
After charging 0.001 part of 4-hydroxytoluene and degassing the inside of the autoclave under vacuum, 100 parts of vinyl chloride was press-fitted. Thereafter, polymerization was carried out at 58 ° C. for 5 hours with stirring, and after a post-treatment and a drying step, a vinyl chloride resin was obtained. The polymerization degree of this vinyl chloride resin was 1,000.

Into a reactor, 230 parts of pure water and 100 parts of a vinyl chloride resin are charged, vacuum degassing and nitrogen replacement are carried out under stirring, and after chlorine degassing, chlorine gas is blown into the reactor.
A chlorination reaction was performed at 85 ° C. by irradiation with a high-pressure mercury lamp of watts. When the chlorine content reached 67%, the irradiation of the mercury lamp was stopped to stop the chlorination reaction. The reaction time is 3.
It was eight hours. After expelling unreacted chlorine with nitrogen, the remaining hydrochloric acid was removed by washing with water and dried to obtain a chlorinated vinyl chloride resin.

The chlorinated vinyl chloride resin 1 obtained above
10 parts by weight of B31 (MBS resin manufactured by Kanegafuchi Chemical Industry Co., Ltd.), 2 parts by weight of a tin-based stabilizer,
1.7 parts of lubricant are blended, rolled and pressed,
Physical properties were evaluated. Table 1 shows the evaluation results.

Example 3 A vinyl chloride resin having a degree of polymerization of 1000 was obtained in the same manner as in Example 2, except that 0.003 parts of 3,5-ditert-butyl-4-hydroxytoluene was used. A chlorinated vinyl chloride resin was obtained in the same manner as in Example 2 except that the chlorination reaction time was changed to 3.9 hours.

With respect to 100 parts by weight of the obtained chlorinated vinyl chloride resin, B31 (manufactured by Kaneka Chemical Co., Ltd., MBS)
10 parts by weight of a resin), 2 parts by weight of a tin-based stabilizer, and 1.7 parts of a lubricant, and roll and press were performed to evaluate physical properties. Table 1 shows the evaluation results.

Example 4 A polymerization degree of 1000 was obtained in the same manner as in Example 2 except that 0.01 part of 3,5-ditert-butyl-4-hydroxytoluene was used and the polymerization time was 5.1 hours. Of vinyl chloride resin was obtained. B31 (MBS resin manufactured by Kanegafuchi Chemical Co., Ltd.) was used in an amount of 10 parts by weight, based on 100 parts by weight of the obtained chlorinated vinyl chloride resin, except that the chlorination reaction time was 4.0 hours. 2 parts by weight of a tin-based stabilizer and 1.7 parts of a lubricant were blended, rolled and pressed to evaluate physical properties. Table 1 shows the evaluation results.

Comparative Example 1 The procedure of Example 2 was repeated except that 0.015 part of 3,5-ditert-butyl-4-hydroxytoluene was used and the polymerization time was 5.3 hours.
A vinyl chloride resin having a polymerization degree of 1000 was obtained. Example 2 was repeated except that the chlorination reaction time was 4.7 hours.
A chlorinated vinyl chloride resin was obtained in the same manner as described above.

To 100 parts by weight of the obtained chlorinated vinyl chloride resin, B31 (manufactured by Kaneka Chemical Co., Ltd.)
10 parts by weight of S), 2 parts by weight of a tin-based stabilizer, and 1.
Seven parts were blended, rolled and pressed, and the physical properties were evaluated. Table 1 shows the evaluation results.

Comparative Example 2 A polymerization degree of 1000 was obtained in the same manner as in Example 2 except that 0.02 parts of 3,5-di-tert-butyl-4-hydroxytoluene was used and the polymerization time was 5.5 hours. Of vinyl chloride resin was obtained. A chlorinated vinyl chloride resin was obtained in the same manner as in Example 2 except that the chlorination reaction time was changed to 5.6 hours.

To 100 parts by weight of the obtained chlorinated vinyl chloride resin, B31 (MB, manufactured by Kaneka Chemical Co., Ltd.) was used.
10 parts by weight of S), 2 parts by weight of a tin-based stabilizer, and 1.
Seven parts were blended, rolled and pressed, and the physical properties were evaluated. Table 1 shows the evaluation results.

[0028]

[Table 1]

[0029]

As is clear from the examples and comparative examples, by chlorinating a vinyl chloride resin substantially free of an antioxidant, the initial coloring property during processing of the chlorinated vinyl chloride resin can be improved. The reaction time can be shortened and productivity can be improved without sacrificing thermal stability.

Continued on the front page F term (reference) 4J011 AA05 JA06 JA07 JA08 JB04 4J100 AC03P CA01 CA31 FA02 FA21 HA21 HB04

Claims (6)

[Claims] 1. A method for producing a chlorinated vinyl chloride resin, which comprises chlorinating a vinyl chloride resin containing substantially no antioxidant in an aqueous suspension. 2. The method for producing a chlorinated vinyl chloride resin according to claim 1, wherein the chlorination is performed using a mercury lamp. 3. The process for producing a chlorinated vinyl chloride resin according to claim 1, wherein the vinyl chloride resin contains 0.01% by weight or less of an antioxidant. 4. The method for producing a chlorinated vinyl chloride resin according to claim 1, wherein the vinyl chloride resin contains 0.005% by weight or less of an antioxidant. 5. A vinyl chloride resin comprising partially saponified polyvinyl alcohol, hydroxypropyl methylcellulose,
5. The chlorinated vinyl chloride-based resin production according to claim 1, 2, 3, or 4, which is a vinyl chloride-based resin obtained by suspension polymerization using at least one dispersant selected from polyethylene oxide. Method. 6. A vinyl chloride resin in an aqueous suspension in an amount of 20 to 3%.
6. The method for producing a chlorinated vinyl chloride resin according to claim 1, wherein the chlorination is carried out at a resin concentration of 5% by weight.