JP2985101B2 - Polymerization method of vinyl chloride - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

In the present invention, the polymerization time can be shortened by using a specific peroxyester in combination with an organic peroxide (hereinafter abbreviated as "peroxide") having a half-life of 10 hours (hereinafter abbreviated as "half-life temperature") of 40 to 60C. In addition, the present invention relates to a method for polymerizing vinyl chloride in which the obtained polymer has improved thermal stability.

[Prior art]

In order for vinyl chloride resin manufacturers to improve the productivity of general-purpose resins, peroxides capable of shortening the polymerization time are required. In particular, lowering the polymerization temperature in order to obtain a product having a high degree of polymerization poses a serious problem, and the need for further shortening the polymerization time has arisen. Generally, as a method of shortening the polymerization time, (1) the amount of peroxide is increased. (2) A method in which two types of peroxides are used in combination, particularly a method in which a peroxide having a high half-life temperature and a peroxide having a low half-life are used in combination. However, when the method (1) is adopted, a peak of heat generation may occur at the end of the polymerization, and the heat may not be removed. In addition, the handling amount of the peroxide increases, and a safety problem occurs. Further, the thermal stability of the obtained resin is also deteriorated. An example employing the method (2) is disclosed in
As shown in No. 9407, α-cumylperoxy neodecanoate is used as a peroxide having a low half-life temperature, and dialkyl peroxydicarbonates are used as a catalyst having a high half-life temperature. Even in this system, it cannot be said that the polymerization time has been shortened yet. This is particularly noticeable when the polymerization temperature is lowered to increase the degree of polymerization. Another example of the method (2) is disclosed in JP-B-46-14670. In this case, acetylcyclohexylsulfonyl peroxide is used as the peroxide having a low half-life temperature, and the same dialkyl peroxydicarbonates are used as the peroxide having a high half-life temperature. At this time, the half-life temperature of acetylcyclohexylsulfonyl peroxide is lower than that of α-cumylperoxy neodecanoate (38
C.), the polymerization time is considerably shortened, but the thermal stability of the obtained polymer is poor.

[Problems to be solved by the invention]

The problem to be solved by the present invention is to find a new peroxide combination system which shortens the polymerization time in the homopolymerization or copolymerization of vinyl chloride and does not impair the thermal stability of the polymer.

[Means for solving the problems]

The present inventors have conducted intensive studies on various peroxides in order to solve the above problems, and as a result, have completed the present invention. That is, (A) at least one selected from cumyl peroxy neotridecanoate, paramenthyl peroxy neotridecanoate, and 1,3-bis (neotridecanyl peroxyisopropyl) benzene, and (B) 40 to 60 ° C. Of 10
The present invention relates to a method for polymerizing vinyl chloride or a mixture of vinyl chloride and a monomer copolymerizable therewith, characterized by mixing and using at least one selected from organic peroxides having a time half-life temperature. Achieved. This is because the component (A) is excellent in combination with alkylperoxyesters and dialkylperoxydicarbonates having a half-life temperature of 40 to 60 ° C., which is used for vinyl chloride polymerization, and the half-life temperature is preferably a preferable temperature. It seems that the object of the present invention has been achieved because of the area. The half-life temperature of (A) cumyl peroxy neotridecanoate (A) used in the present invention is 34 ° C., that of paramenthyl peroxy neo tridecanoate is 32 ° C., 1,3-bis (neotridedecanoyl peroxyisopropyl) That of benzene is 34 ° C. As the peroxide having a half-life temperature of 40 to 60 ° C. as the component (B), diisopropyl peroxydicarbonate, disecondary-butylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, di-1-methylheptylperoxydicarbonate,
Dicyclohexyl peroxydicarbonate, bis (4
-Tert-butylcyclohexyl) peroxydicarbonate, dioctyl peroxydicarbonate, dilauryl peroxydicarbonate, dialkyl peroxydicarbonates such as dimyristyl peroxydicarbonate, tertiary butyl peroxypivalate, tertiary butyl peroxy neohexanoate, Tertiary butyl peroxy neoheptanoate, tertiary butyl peroxy neononanoate,
Tertiary butyl peroxy neodecanoate, tertiary butyl peroxy neotridecanoate, tertiary amyl peroxy pivalate, tertiary amyl peroxy neo hexanoate, tertiary amyl perxinone nonano nanoate, tertiary amyl perneo neocanoate Ethate, tertiary amyl peroxy neotridecanoate, tertiary hexyl peroxy neoxanoate, tertiary hexyl peroxy neohexanoate, tertiary hexyl peroxy neo nonanoate, tertiary hexyl peroxy neodecanoate, tertiary octyl peroxy pivalate , Tertiary octyl peroxy neo hexanoate, alkyl peroxy esters such as tertiary octyl neononanoate It is exemplified. When the half-life temperature is 40 ° C. or lower, there is no difference from the half-life temperature of the peroxide of the component (A), and the heat generation does not become uniform. On the other hand, when the temperature is higher than 60 ° C., the difference from the peroxide of the component (A) is so large that not only the heat generation does not become uniform but also the polymerization time cannot be shortened. Monomers copolymerizable with vinyl chloride used in the present invention include ethylene, propylene, vinyl acetate, acrylic acid or its esters, methacrylic acid or its esters, maleic acid or its esters,
Examples thereof include alkyl vinyl ether. The amount of peroxide used in the present invention is usually 10
0.005 to 0.5 parts by weight per 0 parts by weight. If the amount is less than 0.005 parts by weight, the polymerization will be remarkably delayed, and if it exceeds 0.5 parts by weight, the polymerization reaction will occur rapidly and it will be difficult to control the temperature. Also, the mixing ratio of the peroxide (A) component and (B) component is 1:
It is used in the range of 0.1 to 10, but outside the range, it is difficult to achieve the object of the present invention. The component (A) used in the present invention is produced by a general method for producing peroxyesters. That is, the hydroperoxide and neotridecanoic acid chloride (Ecid-13 manufactured by Idemitsu Petrochemical Industry Co., Ltd., converted to an acid chloride by an ordinary method) in the presence of 5 to 40% by weight of an alkali metal hydroxide were added to the -10- It is produced by reacting at 30 ° C. Further, the peroxide used in the present invention may be used after being diluted with an inert solvent such as an aliphatic hydrocarbon, an aromatic hydrocarbon and an ester, if necessary.

【The invention's effect】

When the polymerization method of the present invention is used, the heat generated by the polymerization is uniform, the polymerization time is shortened, the productivity is improved, and the thermal stability of the resin obtained by the polymerization is also greatly improved.

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. Example 1 1 g of partially saponified polyvinyl alcohol and ion-exchanged water were placed in a 5 stainless steel autoclave having a stirrer.
Mix 3000 g and stir well to dissolve. 1500 g of a vinyl chloride monomer in which 0.95 g of cumyl peroxy neotridecanoate and 0.10 g of tert-butyl neodecanoate were dissolved were injected. While stirring, the internal temperature was raised to 50 ° C. to carry out polymerization. After 4 hours, the internal pressure dropped 4.5 kg / cm ² from the equilibrium pressure. At this time, the polymerization slurry was taken out, and the obtained polymer was filtered and dried. The conversion was 90%. Since the thermal stability of the vinyl chloride resin is remarkable in the initial coloring of the resin, an initial coloring test was performed. The results of the initial coloring test are shown in Table 1 together with the following Examples and Comparative Examples. [Initial Coloring Test] 100 g of the vinyl chloride resin was mixed with 50 g of dioctyl phthalate and 2.5 g of dibutyltin maleate, kneaded at 160 ° C. for 7 minutes, and the coloring of the sheet was visually observed. Example 2 The vinyl chloride monomer of Example 1 was replaced with a vinyl acetate monomer (300 g).
To a mixture of 1,200 g of vinyl chloride monomer with peroxide
Bis (neotridedecanoyl peroxyisopropyl) benzene 0.74g, tert-butyl peroxypivalate
Polymerization was carried out in the same manner as in Example 1 except that the amount was changed to 0.41 g. After 4 hours, the internal pressure dropped 4.5 kg / cm ² from the equilibrium pressure. 90% polymerization rate
Met. Example 3 Polymerization was carried out in the same manner as in Example 1 except that the peroxide of Example 1 was changed to 1.13 g of paramenthylperoxyneotridedecanoate and 0.35 g of di-2-ethylhexylperoxydicarbonate. After 4 hours, the internal pressure dropped 4.5 kg / cm ² from the equilibrium pressure. The conversion was 92%. Example 4 Polymerization was carried out in the same manner as in Example 3 except that the polymerization temperature in Example 3 was changed to 43 ° C. At 4.5 hours, the internal pressure dropped 4.5 kg / cm ² from the equilibrium pressure. The conversion was 90%. Comparative Example 1 Polymerization was carried out by changing the peroxide of Example 4 to 0.94 g of α-cumylperoxy neodecanoate and 0.35 g of di-2-ethylhexyl peroxydicarbonate. After 7 hours, the internal pressure dropped 4.5 kg / cm ² from the equilibrium pressure. The conversion was 91%. Comparative Example 2 Polymerization was carried out by changing the peroxide of Example 4 to 0.68 g of acetylcyclohexylsulfonyl peroxide and 0.35 g of di-2-ethylhexylperoxydicarbonate. 4
Over time, the internal pressure dropped 4.5 kg / cm ² below the equilibrium pressure. The conversion is 9
It was 0%. Separate table

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Claims (1)

(57) [Claims] (A) Cumyl peroxy neotridecanoate, paramenthyl peroxy neotridecanoate,
And at least one selected from 1,3-bis (neotridedecanoylperoxyisopropyl) benzene and (B)
A mixture of vinyl chloride or a monomer copolymerizable therewith with at least one selected from organic peroxides having a 10-hour half-life temperature of 40 to 60 ° C. Polymerization method.