JP3241883B2 - Polymerization method of vinyl chloride monomer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention uses a mixture of a specific peroxyester and a specific peroxide having a half-life temperature of 10 hours (hereinafter abbreviated as "half-life temperature") of 43 DEG C. to 65 DEG C. as a polymerization initiator. And a method for polymerizing a vinyl chloride-based monomer to obtain a polymer by polymerizing a vinyl chloride-based monomer alone or a mixture mainly composed of a vinyl chloride-based monomer and a monomer capable of copolymerizing the same. About.

[0002]

2. Description of the Related Art In recent years, peroxyester-based organic peroxides have been used because a vinyl chloride monomer is polymerized and the color of a processed product of the polymer is better than other organic peroxides. I have. Further, the properties of a polymer obtained by polymerizing a vinyl chloride monomer are greatly affected by the degree of polymerization, and the degree of polymerization is largely controlled by the polymerization conditions, especially the polymerization temperature. Generally, the polymerization degree is 1100 or less, and the polymerization temperature is 57 to 70.
A vinyl chloride polymer obtained by suspension polymerization at a temperature of ° C. has the most suitable properties as a film, a sheet and the like, and is widely used in industry.

Various manufacturers have used various polymerization initiators for the production of these general-purpose resins at the manufacturers of vinyl chloride. However, since the color of processed products is improved, peroxyester-based organic peroxides are used. Things are used.

When tert-butyl peroxypivalate, a typical peroxyester-based organic peroxide, is used, it has been conventionally used because of its excellent initial coloring property of the polymer. However, the adhesion of the scale is a problem. At the time of suspension polymerization of the vinyl chloride monomer, the adhesion of the scale to the polymerization vessel wall or the like lowers the cooling efficiency of the jacket provided for removing the generated polymerization heat, and hinders the temperature control. Decreases the stirring effect. Furthermore, the scale is mixed into the product, causing so-called fish eyes, which lowers the quality of the product.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to propose a polymerization method using a polymerization initiator which has a good hue of a processed product and can reduce the adhesion of scale during polymerization. .

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies on a method of polymerizing vinyl chloride monomers using various organic peroxides.
(1) In obtaining a polymer from a vinyl chloride monomer alone or a mixture of a vinyl chloride monomer as a main component and a monomer copolymerizable therewith, (A) Tertiary butyl peroxy neoheptanoe
And (B) 1,1-dimethylbutylperoxyneodeca
Group consisting of noate and diisononanoyl peroxide
Use a polymerization initiator mixed with at least one selected from
A method for polymerizing a vinyl chloride monomer, wherein a polymer having a polymerization degree of 1100 or less is obtained by suspension polymerization at 57 ° C. to 70 ° C.

Embedded image (2) vinyl chloride monomer alone or mainly of vinyl chloride monomer, with respect to the charged amount of the mixture of monomers copolymerizable with this, the combined polymerization initiator 0.03 ~
The present inventors have found a method for polymerizing a vinyl chloride-based monomer as described in 1 above, characterized by using 0.15% by weight, and have completed the present invention.

The component (B) used in the present invention includes:
1,1-dimethylbutyl peroxy neodecanoate and
Selected from the group consisting of diisononanoyl peroxide
At least one kind is exemplified.

In the present invention, the amount of a general polymerization initiator used in the polymerization of a vinyl chloride monomer is mainly a mixture of a vinyl chloride monomer and a copolymerizable monomer. Is 0.03 to 0.15% by weight with respect to the charged amount.
If it is less than 0.03% by weight, the polymerization rate becomes extremely slow,
On the other hand, if the content exceeds 0.15% by weight, the polymerization reaction occurs rapidly and it becomes difficult to control the temperature.

In the present invention, the mixture molar ratio of the component (A) and the component (B) is used in the range of 1.0: 0.1 to 1.0: 10.0. Outside this range, it is difficult to achieve the object of the present invention.

[0010] Examples of the vinyl chloride monomer in the present invention include vinyl chloride and vinylidene chloride.

The other vinyl monomers copolymerizable with the vinyl chloride monomer in the present invention include copolymers with ethylene, vinyl acetate, styrene and acrylates.

The component (A) used in the present invention is produced by a general method for producing peroxyesters.
As an example, it is produced by reacting tert-butyl hydroperoxide with neoheptanoic acid chloride at -10 to 30 ° C in the presence of 5 to 40% by weight of an alkali metal hydroxide.

[0013]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the embodiments.

In the examples and comparative examples, all initiators used had a concentration of 70% by weight (diluent: isoparaffin).

Reference Example In a 5 l stainless steel autoclave having a stirrer, 1 g of partially saponified polyvinyl alcohol and 3000 g of ion-exchanged water were charged and stirred well to dissolve. The system was sufficiently purged with nitrogen, and a polymerization initiator mixture of 0.17 g of tert-butyl neoheptanoate (TB-NHP) and 0.30 g of di-2-ethylhexylperoxydica-bonate (OPD) was added. 1500 g of the dissolved vinyl chloride monomer were injected. The polymerization was carried out at an internal temperature of 57 ° C. while stirring. After 8 hours, the internal pressure was lower than the equilibrium pressure by 4.5 kg / cm3. The vinyl chloride produced at this point was filtered, washed and vacuum dried at 40-50 ° C. The conversion was 95.0%.

A fisheye measurement test was conducted using the obtained vinyl chloride polymer. The results are shown in Table 1.

[Adhesion Test] The total amount of scale adhesion to the reactor wall after 10 polymerization tests was examined.

[Fish eye measurement test] Vinyl chloride polymer 100 parts by weight DOP (dioctyl phthalate) 50 parts by weight Tribasic lead sulfate 0.5 parts by weight Lead stearate 1.5 parts by weight Titanium oxide 0.1 part by weight Parts carbon black 0.05 parts by weight 25 g of the mixture prepared according to the above mixing recipe was kneaded at 140 ° C. for 5 minutes by a 6 ″ × 15 ″ roll for kneading, and was 10 cm wide and 0.1 cm thick.
A 2 mm sheet is molded. The number of transparent particles per 100 cm 2 of the obtained sheet was counted and used as an index of fish eye.

Example 1 The monomer of Reference Example was prepared by adding 1200 g of vinyl chloride and
00g, and the polymerization initiator was changed to TB-NHP0.3
4g of 1,1-dimethyl-butyl peroxide neodecanoate Noe - except for changing the mixture of bets (TNH-ND) 0.47g ginseng
It was performed according to the example.

Example 2 0.17 g of TB-NHP and TNH were used as the polymerization initiators of the reference example.
Polymerization was carried out according to the Reference Example except that the mixture was changed to 0.24 g of -ND and the polymerization temperature was changed to 63 ° C.

[0021] Example 3 changing the polymerization initiator of Example in a mixture of TB-NHP0.34g and diisononanoyl peroxide (NPO) 0.47g, except that the polymerization temperature to 63 ° C. according to Reference Example Polymerization Was performed.

COMPARATIVE EXAMPLE 1 0.30 g of OPD was used as the polymerization initiator of Reference Example and tertiary.
Polymerization was carried out according to the Reference Example except that 0.16 g of butyl peroxypivalate (TBPP) was used instead of the polymerization initiator mixture.

COMPARATIVE EXAMPLE 2 0.47 g of TNH-ND and TBP were used as the polymerization initiator of the reference example.
Polymerization was carried out according to Reference Example except that the mixture was changed to 0.32 g of P and the polymerization temperature was changed to 63 ° C.

[0024] NPO0.47g the polymerization initiator of Comparative Example 3 Reference Example and TBPP0.
Except that the polymerization temperature was changed to 63 ° C instead of 32g of the mixture.
Polymerization was performed according to the reference example .

Table 1 shows the above results. From the table, it is known that the combination of the initiators known in the art has a problem that the quality of the product is deteriorated due to the adhesion of the scale and the formation of fish eyes resulting from the combination. However, tertiary butyl peroxy neoheptanoate and a specific excess It can be seen that this problem is remarkably improved when used in a mixed system with an oxide.

[0026]

The use of the specific peroxyester of the present invention in combination with a specific peroxide having a half-life temperature of 43 ° C. to 65 ° C. improves the adhesion of scale to the reactor wall during polymerization. Therefore, it is possible to improve the quality deterioration of the product due to the generation of fish eyes caused by the fish eye.

[0027]

[Table 1]

──────────────────────────────────────────────────続 き Continuation of the front page (72) Eiji Fujikawa, inventor, Sanken Kako Co., Ltd., 2-10-6 Miyanishi, Harima-cho, Kako-gun, Hyogo Prefecture (56) References JP-A-3-28205 (JP, A) JP-A-4-9365 (JP, A) JP-A-59-56409 (JP, A) JP-B-51-38752 (JP, B1) JP-B-47-18852 (JP, B1) (58) (Int.Cl. ⁷ , DB name) C08F 14/00-14/28 C08F 4/32-4/38

Claims (2)

(57) [Claims] (A) General formula (1) (R1, R2, and R3 are each an alkyl group having 1 or more carbon atoms, and the total number of carbon atoms is 5.) Tertiary-butylperoxyneoheptanoate represented by the formula (B) 1,1 -Dimethylbutyl peroxy
Polymerization mixed with at least one selected from the group consisting of sineodecanoate and diisononanoyl peroxide
By using an initiator and performing suspension polymerization at 57 ° C to 70 ° C, a polymer having a degree of polymerization of 1100 or less is obtained. And a method of polymerizing a mixture with a monomer copolymerizable therewith. 2. A vinyl chloride monomer alone or mainly of vinyl chloride monomer, with respect to the charged amount of the mixture of monomers copolymerizable with this, the combined polymerization initiator 0 .
The method for polymerizing a vinyl chloride-based monomer according to claim 1, wherein the amount is from 03 to 0.15% by weight.