JPH04198306A - Polymerization of vinyl chloride monomer - Google Patents

Abstract

PURPOSE:To polymerize a vinyl chloride monomer in short polymerization time and to obtain a polymer emitting low odor in processing and giving a processed good having improved hue by using a polymerization initiator consisting of a mixture of t-octyl peroxyneotridecanoate and a specific compound. CONSTITUTION:A vinyl chloride monomer is polymerized by using a polymerization initiator produced by mixing (A) tert. octyl peroxyneotridecanoate and (B) at least one kind of compound having a 10-hr half-life temperature of 40-65 deg.C and selected from dialkyl peroxydicarbonate (e.g. diisopropyl peroxy- dicarbonate), peroxy ester (e.g. tert. butyl peroxypivalate) and diacyl peroxide (e.g. lauroyl peroxide). The amount of the initiator is 0.005-0.5 pts.wt. per 100 pts.wt. of vinyl chloride and the ratio of A/B is preferably 1/(0.1-10.0).

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention uses a specified peroxy ester and a peroxide having a 10-hour half-life temperature (hereinafter referred to as "half-life temperature") of 40 to 65°C as a polymerization M initiator. Step 1 for producing a polymer or a copolymer with a monomer copolymerizable with the polymer
This invention relates to a method for polymerizing vinyl chloride polymers, which can shorten polymerization time, reduce odor during processing, and improve the hue of processed products. [Prior Art 1] Vinyl chloride manufacturers are looking for organic peroxides that can shorten the polymerization time in order to improve the productivity of general-purpose resins. For example, dialkyl peroxydicarbonates WI (such as diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate)
Half-life temperature: 40-45°C) is used as a polymerization initiator for vinyl chloride, but the hue of processed products is inferior. Further, conventionally used peroxyesters such as tert-butyl peroxy bivalate and tert-butyl peroxy neodecanoate have a half-life temperature so high that a high polymerization rate cannot be obtained in a short period of time. On the other hand, Cumyl Oxyneodecanoate Hagyu Mx! l
Because it is decomposable at a low temperature of 38°C, it is used to shorten the double polymerization time, but if it is used in many ways, it has the disadvantage of producing a strong odor from decomposed products similar to acetophenone and phenol during polymer processing. Various efforts have been made to improve these. For example, Japanese Patent Publication No. 58-120613 proposes that a polymer using tertiary octyl peroxyneodecanoate can be used to obtain an odorless vinyl chloride polymer during processing, but this is still insufficient. In order to improve productivity, a method has been proposed in which an initiator with a short half-life and an initiator with a long half-life are combined in order to make the polymerization rate constant, thereby making the polymerization rate uniform and improving productivity. For example, in Japanese Patent Publication No. 46-14670, a combination of acetylcyclohexylsulfonyl peroxide and dialkyl peroxydicarbonate, which has a long half-life, is used as an initiator with a short half-life. However, if a large amount of acetylcyclohexylsulfonyl peroxide is used, the thermal stability of vinyl chloride will deteriorate. Furthermore, in order to improve thermal stability, JP-A-56-149407 uses a combination of cumyl peroxyneodecanoate and dialkyl peroxydicarbonate. However, in the case of this combination, if a large amount of cumyl peroxyneodecanoate is used, the unique odor of the decomposed products of cumyl peroxyneodecanoate will be emitted when adding plasticizers, kneading, and sacrificing the processed product. be. - [Problems to be solved by the invention] The purpose of the present invention is to shorten polymerization time, improve productivity,
In addition, when #tlIIi obtained by polymerization is kneaded with a plasticizer etc. to produce processed products, it is a polymerization initiator that eliminates odor caused by decomposition products of organic peroxides and improves the hue of processed products. The purpose is to propose a polymerization method using [Means for Solving the Problems] In order to solve the above problems, the present inventors used various organic peroxides and conducted intensive studies on methods for polymerizing vinyl chloride monomers. A) Tertiary octyl peroxy neotridecanoate and (B) half-life temperature 40~
A method for polymerizing vinyl chloride monomers using a polymerization initiator mixed with at least one selected from the kings of dialkyl peroxydicarbonates, peroxy esters, and diacyl peroxides in the range of 65 ° C. We have now completed the present invention.The present invention is characterized by the fact that the chemical structure of component (A) improves the coloring and odor of the polymer, and that the half-life temperature of component (A) is low (38.5°C). (B) Ingredients soprobyl peroxydicarbonate, di-secondary butyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-1-methylhexyl peroxydicarbonate, cimilistyl peroxydicarbonate, dicyclohexyl peroxydicarbonate , di-4-tert-butyl cyclohexyl peroxy dicarbonate, dioctyl peroxy dicarbonate, dioctyl peroxy dicarbonate, dilauryl peroxy dicarbonate, etc., tert-butyl peroxy pivalate, tert-butyl peroxy neodecano Eight, tertiary
Examples include peroxy esters such as butyl peroxy neoheptanate and tertiary butyl peroxy neononanoate, and diacyl peroxides such as lauroyl peroxide, didecanoyl peroxide, and dioctanoyl peroxide. Half-life temperature is 65
If the temperature is higher than 40°C, it is difficult to shorten the polymerization time by reducing the amount of initiator by 2. In addition, if the half-life temperature is lower than 40°C, it is difficult to make the polymerization rate uniform. In the present invention, the amount of a general polymerization initiator used during the polymerization of vinyl chloride monomers is 0.00% per 100 weight tS of vinyl chloride.
005-0.5 weight ts. If it is less than 0.005 parts by weight, the polymerization rate becomes extremely slow;
Moreover, if the amount exceeds 0.5 parts by weight, a polymerization reaction will occur rapidly.
Temperature control becomes difficult. In the present invention, the mixing ratio of component (A) and (B) li is used in the range of 1:0.1 to 10.0.6 If the mixing ratio is outside this range, it is difficult to achieve the purpose of the present invention. It becomes better. In the polymerization of the vinyl chloride monomer in the present invention, other copolymerizable vinyl monomers 1 such as ethylene, vinyl acetate,
Copolymers with vinylidene chloride, styrene, acrylic esters, etc. are also included. Punishment 1 1g of (A) I & Min used in the present invention is produced by a general method for producing peroxyesters, -
For example, it is produced by reacting tertiary octylhydro in the presence of 5 to 40% by weight of alkali metal hydroxide at a temperature of 30 DEG C. to 30 DEG C.

【Effect of the invention】

If the mixed polymerization initiator of the present invention is used, the polymerization time is shorter than when cumyl peroxyneodecanoate is used alone, and the resin obtained by polymerization can be mixed with a thermosetting agent etc. When manufacturing processed products, there is less odor caused by decomposition products of organic peroxides, and the color of processed products is also improved. [Example] The method of the present invention will be explained in more detail with reference to Examples below. Example 1 In a 51 stainless steel autoclave with stirring #-, 1 g of 1lII saponified polyvinyl alcohol and aooog of ion-exchanged water were charged, stirred well, and dissolved.
The inside of the system was sufficiently purged with nitrogen, and 1500 g of vinyl chloride monomer in which 0.577 g of tertiary octyl peroxyneotridecanoate and 0.333 g of di-2-ethylhexyl peroxydicarbonate were dissolved was pressed. While stirring, the internal temperature was raised to 57° C. for polymerization. In 4 hours and 30 minutes, the internal pressure decreased by 4.5 kg/crd from the equilibrium pressure. At this point, the vinyl chloride produced is filtered and washed.
It was vacuum dried at 0°C. The polymerization rate was 90.9%. An initial coloring test was conducted using the obtained vinyl chloride. At the same time, we investigated the odor. The results are shown in the attached table. [Initial coloring test] 50 g of dioctyl phthalate and 2.5 g of dibutyl tin malate were mixed with 100 g of vinyl chloride and kneaded at 160° C. for 7 minutes, and the degree of coloring of the sheet was visually observed. [Odor test: The odor of the sheet that scored 8 in the initial coloring test was investigated. Example 2 Polymerization was carried out in accordance with Example 11, except that the polymerization N# agent in Example 1 was changed to 577 g of tertiary octyl peroxy neotridecanoate Q and 0.234 g of tertiary butyl peroxy neotridecanoate. Example 3 The polymerization initiator in Example 1 was changed to 0.721 g of tertiary octyl peroxyneotridecanoate and 0.151 g of tertiary butyl peroxyneotridecanoate,
In addition, the single polymers were 1200g of vinyl chloride and 300g of vinegar-vinyl.
Polymerization was carried out according to Example 1 instead of using g. Comparative Example 1 - Polymerization was carried out according to Example 1 except that the polymerization initiator in Example 1 was changed to 0.882 g of cumyl peroxyneodecanoate. Comparative Example 2 Polymerization of vinyl chloride was carried out according to Example 11 except that the polymerization initiator of Example 1 was changed to 0.588 g of cumyl peroxyneodecanoate and 0.333 g of di-2-ethylhexylberoxydicarbonate. I did this. 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-nitylhexyl peroxydicarbonate. The above results are shown in the attached table.The table shows that the combinations of known initiators had poor productivity or problems in terms of heat stability and odor, but the mixed initiator of the present invention has both of these problems. It can be seen that it has been improved. Separate table

Claims (1)

[Claims] (A) tertiary octyl peroxy neotridecanoate; and (B) at least one member selected from the group consisting of dialkyl peroxy dicarbonates, peroxy esters, and diacyl peroxides having a 10-hour half-life temperature in the range of 40 to 65°C; A method for polymerizing vinyl chloride monomers, characterized by using a polymerization initiator mixed with.