JP3013319B2 - Polymerization method of vinyl chloride monomer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention uses a specific peroxyester and a peroxide having a 10-hour half-life temperature (hereinafter, abbreviated as a half-life temperature) of 40 to 65 ° C. as a polymerization initiator, and polymerizing vinyl chloride or copolymerizing the same. The present invention relates to a method for polymerizing a vinyl chloride polymer, which can shorten the polymerization time when producing a copolymer with the obtained monomer, reduce odor during processing, and improve the color of processed products.

[Prior art]

In order to improve the productivity of general-purpose resins, vinyl chloride manufacturers are demanding organic peroxides capable of shortening the polymerization time. For example, dialkyl peroxy dicarbonates (half-life temperature of 40 to 45 ° C.) such as diisopropyl peroxy dicarbonate and di-2-ethylhexyl peroxy dicarbonate are used as a polymerization initiator of vinyl chloride, but the color of processed products is inferior. . Also, tertiary butyl peroxypivalate, which has been conventionally used,
Peroxyesters such as tertiary butyl peroxyneodecanoate have too high a half-life temperature and cannot achieve a high conversion in a short time. On the other hand, cumyl peroxy neodecanoate has a half-life temperature of 38 ° C and is decomposable at low temperature, so it is used to shorten the polymerization time. There is a drawback that the decomposition product has a strong odor. Various devices have been devised for these improvements. For example, Japanese Patent Publication No. 58-120613 proposes that a polymer using tertiary octyl peroxy neodecanoate can obtain a vinyl chloride polymer having no odor during processing. However, this polymerization initiator has a slightly high half-life temperature (42 ° C.) and the effect of shortening the polymerization time is still insufficient. In order to improve the productivity, a method has been proposed in which an initiator having a short half-life and an initiator having a long half-life are combined to make the polymerization rate uniform and improve the productivity in order to keep the polymerization rate constant. For example, Japanese Patent Publication No. 46-14670 discloses a combination of acetylcyclohexylsulfonyl peroxide and a half-life dialkyl peroxydicarbonate as an initiator having a short half-life. However, when a large amount of acetylcyclohexylsulfonyl peroxide is used, the heat stability of vinyl chloride deteriorates. JP-A-56-149407 uses a combination of cumyl peroxy neodecanoate and a dialkyl peroxy dicarbonate as an improvement in thermal stability. However, in the case of this combination, when a large amount of cumyl peroxy neodecanoate is used, a peculiar odor of the decomposition product of cumyl peroxy neodecanoate is produced when a plasticizer is added and kneaded to produce a processed product. is there.

[Problems to be solved by the invention]

The object of the present invention is to shorten the polymerization time, improve the productivity, and furthermore, add a plasticizer or the like to the resin obtained by polymerization and knead it to produce a processed product. An object of the present invention is to propose a polymerization method using a polymerization initiator which has a low odor and improves the hue of a processed product.

[Means for solving the problems]

The present inventors have conducted intensive studies on a method for polymerizing a vinyl chloride monomer using various organic peroxides to solve the above-mentioned problems. As a result, (A) tertiary octyl peroxy neotridecanoate and ( B) Half-life temperature 40-65
A dialkyl peroxydicarbonate in the range of ° C.
The present inventors have found a method for polymerizing a vinyl chloride monomer using a polymerization initiator in which at least one selected from a peroxyester and a diacyl peroxide is mixed, and have completed the present invention. The present invention improves the coloration and odor of the polymer by the chemical structure of the component (A), reduces the half-life temperature of the component (A) (38.5 ° C.), and increases the polymerization rate by using it together with the component (B). I think that the polymerization time was shortened while being stabilized. As the component (B) used in the present invention, diisopropyl peroxydicarbonate, disecondary butyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-1-methylbutyl peroxydicarbonate, dimyristyl peroxydicarbonate, Dicyclohexyl peroxydicarbonate,
Dialkyl peroxy dicarbonates such as di-4-tert-butyl cyclohexyl peroxy dicarbonate, dineopentyl peroxy dicarbonate, dioctyl peroxy dicarbonate, dilauryl peroxy dicarbonate, tertiary butyl peroxy pivalate, tertiary butyl peroxy neodeca Noate, tertiary butyl peroxy neoheptanate,
Peroxyesters such as tertiary butyl peroxy neononanoate and lauroyl peroxide,
Examples thereof include diacyl peroxides such as didecanoyl peroxide and dioctanoyl peroxide. When the half-life temperature is higher than 65 ° C., it is difficult to reduce the polymerization time with a small amount of initiator. On the other hand, when the half-life temperature is lower than 40 ° C., the polymerization rate is difficult to be uniform. In the present invention, the amount of the general polymerization initiator used in the polymerization of the vinyl chloride monomer is 0.005 per 100 parts by weight of vinyl chloride.
0.5 parts by weight. If the amount is less than 0.005 parts by weight, the polymerization rate becomes extremely slow. In the present invention, the mixing ratio of the component (A) and the component (B)
1: Used in the range of 0.1 to 10.0. Outside this range, it is difficult to achieve the object of the present invention. The polymerization of the vinyl chloride monomer in the present invention includes copolymerization with other copolymerizable vinyl monomers such as ethylene, vinyl acetate, vinylidene chloride, styrene, and acrylates. The component (A) used in the present invention is produced by a general method for producing peroxyesters. As an example, tertiary octyl hydroperoxide and neotridecanoic acid chloride (Ec Acid-13 manufactured by Idemitsu Petrochemical Co., Ltd. in the presence of 5 to 40% by weight of an alkali metal hydroxide are converted to acid chlorides by an ordinary method). −10
Manufactured by reacting at 3030 ° C.

【The invention's effect】

When the mixed polymerization initiator of the present invention is used, the polymerization time is shorter than when cumyl peroxy neodecanoate is used alone, and the resin obtained by polymerization is processed by adding a plasticizer or the like and kneading. In the production of products, the odor due to the decomposition products of organic peroxides is small, and the color of processed products is also improved.

【Example】

Hereinafter, the method of the present invention will be described in more detail by way of examples. Example 1 In a 51 stainless steel autoclave having a stirrer, 1 g of partially saponified polyvinyl alcohol and 3,000 g of ion-exchanged water were charged and thoroughly stirred and dissolved. The system was sufficiently purged with nitrogen, and 1500 g of a vinyl chloride monomer in which 0.577 g of tertiary octyl peroxy neotridecanoate and 0.333 g of di-2-ethylhexyl peroxydicarbonate were dissolved were injected. While stirring, the internal temperature was adjusted to 57 ° C. to carry out polymerization. After 4 hours and 30 minutes, the internal pressure was lower than the equilibrium pressure by 4.5 kg / cm ² . The vinyl chloride produced at this point is filtered, washed and
Vacuum dried at ℃. The conversion was 90.9%. An initial coloring test was performed using the obtained vinyl chloride. At the same time, the odor was checked. The results are shown in the attached table. [Initial Coloring Test] 50 g of dioctyl phthalate and 2.5 g of dibutyltin malate were mixed with 100 g of vinyl chloride, kneaded at 160 ° C. for 7 minutes, and the coloring of the sheet was visually observed. [Odor test] The odor of the sheet formed in the initial coloring test was examined. Example 2 Polymerization was carried out in the same manner as in Example 1 except that the polymerization initiator in Example 1 was changed to 0.577 g of tertiary octyl peroxyneotriedocanoate and 0.234 g of tertiary butyl peroxyneodecanoate. Example 3 The polymerization initiator of Example 1 was changed to 0.721 g of tertiary octyl peroxy neotridecanoate and 0.151 g of diisononanoyl peroxide.
Polymerization was carried out in the same manner as in Example 1 except that the amount of the copolymer was changed to 00 g and 300 g of vinyl acetate. Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that the polymerization initiator in Example 1 was changed to 0.882 g of cumyl peroxy neodecanoate. Comparative Example 2 The polymerization of vinyl chloride was carried out in the same manner as in Example 1 except that the polymerization initiator of Example 1 was changed to 0.588 g of cumyl peroxy neodecanoate and 0.333 g of di-2-ethylhexyl peroxydicarbonate. Comparative Example 3 Vinyl chloride was polymerized in the same manner as in Example 1 except that the polymerization initiator in Example 1 was changed to 0.998 g of di-2-ethylhexyl peroxydicarbonate. The above results are shown in the attached table. From the table, it can be seen that known initiators and combinations have poor productivity or have problems in terms of heat stability and odor, but in the case of the mixed initiator of the present invention, both are improved.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-296504 (JP, A) JP-A-63-289007 (JP, A) JP-A-3-28205 (JP, A) 20309 (JP, A) JP-A-58-120613 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 4/38 C08F 14/06 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] 1. A tertiary octyl peroxy neotridecanoate (A) and a (B) 10-hour half-life temperature of 40 to 65 ° C.
A method for polymerizing a vinyl chloride-based monomer, comprising using a polymerization initiator obtained by mixing at least one selected from the group consisting of dialkyl peroxydicarbonate, peroxyester and diacyl peroxide in the above range.