JPH02194008A - Polymerization of vinyl chloride - Google Patents

Abstract

PURPOSE:To obtain a polymer having good heat stability and freed of fisheye and odor in high yields by using a specified polymerization initiator in the polymerization of a vinyl chloride monomer. CONSTITUTION:alpha-Neodecanoylperoxydiisopropylbenzene (A) is used as a polymerization initiator in the polymerization of a vinyl chloride monomer or a mixture thereof with monomers copolymerizable therewith. When it is used together with another polymerization initiator (B), the polymerization cycle of a vinyl chloride monomer can be shortened. Said component (B) is at least one member selected from among a peroxy ester, a diacyl peroxide and a peroxydicarbonate each having a 10hr half-life temperatures in a 0.1M concentration in benzene of 40-65 deg.C. Its amount is about 1/4-4 times as large as that of component A.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a vinyl chloride monomer, or a vinyl chloride monomer and a monomer copolymerizable therewith. This invention relates to a method for polymerizing vinyl chloride in which a polymer with good physical properties can be obtained in high yield by using a specific polymerization initiator.

(Prior art) Tertiary-butylperoxyneodecanoate (hereinafter abbreviated as BND), 3゜5,5-)limethyl has been conventionally used as a polymerization initiator when polymerizing vinyl chloride monomers. Hexanoyl peroxide (hereinafter abbreviated as NPO), di(2-ethylhexyl) peroxydicarbonate (hereinafter abbreviated as OPP), etc. in benzene.
A polymerization initiator is used whose temperature at which the half-life in a 1 molar concentration solution is 10 hours (hereinafter abbreviated as 10-hour half-life temperature) falls within the range of 40 to 65°C.

However, when such a polymerization initiator is used alone, there are economical problems in that the polymerization efficiency is poor unless the polymerization temperature is relatively high, and the polymerization is not completed unless a large amount is used. In order to improve this point and to shorten the polymerization cycle and increase productivity, lower temperature active polymerization initiators such as diisobutyryl peroxide (hereinafter abbreviated as IBPO) have been developed, which can be used alone or in conventional polymerization. It is used in combination with an initiator.

Specifically, such low-temperature active polymerization initiators include I
1 such as BPO, acetylcyclohexylsulfonyl bertoxide (hereinafter abbreviated as AC3P) and cumylperoxyneodecanoate (hereinafter abbreviated as CHD)
All have a 0-hour half-life temperature of 40°C or lower.

(Problems to be Solved by the Invention) However, the activity of conventional low-temperature active polymerization initiators was not sufficient, and the effect of shortening the polymerization time was small. From this point of view, a polymerization initiator that is more active at lower temperatures is desired.

Moreover, at the same time as such productivity improvement, emphasis has recently been placed on the quality of polymers, and a polymerization initiator that not only has high activity but also improves the quality of polymers is desired.

As described above, conventional low-temperature active polymerization initiators each have problems in terms of productivity improvement and polymer quality improvement.

That is, the polymer obtained by polymerization using I BPO has a fisheye (plate, F
(abbreviated as E) occurs in large numbers.

Furthermore, in AC3P, FE occurs frequently, and the polymer has poor thermal stability and is colored. Furthermore, CND has the disadvantage that, due to its decomposition products, it emits a rather strong characteristic off-odor when the polymer is processed.

FE impairs the appearance of vinyl chloride resin molded products, significantly lowering their commercial value. In addition, the odor of polymers causes environmental deterioration and even impairs the health of workers, which is a serious problem.

(Means for Solving the Problems) As a result of long-term research into the problems of the conventional low-temperature active polymerization initiators, the present inventors found that by using a specific polymerization initiator, higher yields can be achieved. The obtained polymer is free of FE and odor, and at the same time has excellent thermal stability, especially colorability, and furthermore, by using it in combination with other specific polymerization initiators. The present invention was completed by confirming that the polymerization cycle can be shortened compared to when using the method alone.

That is, in the present invention, when polymerizing a vinyl chloride monomer, or a vinyl chloride monomer and a monomer copolymerizable therewith,
As a polymerization initiator, α-neodecanoylperoxydiisopropylbenzene is used alone, or a peroxyester having a half-life of 10 hours in a 0.1 molar solution in benzene is in the range of 40 to 65°C. , diacyl peroxide, and peroxydicarbonate.

Examples of other vinyl monomers that can be copolymerized with the vinyl chloride monomer used in the present invention include ethylene, vinyl acetate, vinylidene chloride, phtylene, and acrylic esters.

The polymerization initiator used in the present invention is α-neodecanoylperoxydiisopropylbenzene, and the amount added is generally 0.001 parts by weight in pure terms per 100 parts by weight of vinyl chloride monomer. ~1 part by weight, preferably 0.01 to 0.5 part by weight. The amount is 0.00
If it is less than 1 part by weight, the polymerization rate tends to be slow. Moreover, if it exceeds 1 part by weight, it becomes difficult to control the polymerization reaction and the physical properties of the obtained polymer tend to deteriorate, which is not preferable. This α-neodecanoylperoxydiisopropylbenzene may be a meta form, a bulk form or a mixture thereof, and is synthesized, for example, as follows.

That is, meta and rose diisopropylbenzene hydroperoxides, each alone or a mixture of the two, and neodecanoic acid chloride are mixed with a normal peroxyester using sodium hydroxide, potassium hydroxide, or an amine such as pyridine as a catalyst. Obtained under similar reaction conditions.

That is, it is synthesized using an aromatic hydrocarbon (e.g., toluene, ethylbenzene) or an aliphatic hydrocarbon (e.g., hexane, octane, petroleum naphtha, mineral spirit, trade name "Shell Sol"; manufactured by Shell Chemical Co., Ltd.) as a catalyst, or Alternatively, it can be used after being diluted after synthesis. Incidentally, the reaction temperature is approximately 0°C to 30°C.

The polymerization initiator used in combination in the present invention is at least one of peroxyesters, diacyl peroxides, and peroxydicarbonates having a 10-hour half-life temperature of 40 to 65°C.

A specific peroxyester is BND (46,5
°C), tertiary-butyl peroxineohexanoate (5
2.1°C), tertiary-butyl peroxypivalate (5
diacyl peroxides such as N P
O (59,5℃), lauroyl peroxide (62℃
), octanoyl peroxide (63℃), etc.
Peroxydicarbonate is OP P (43,5
), di(2-ethoxyethyl) peroxydicarbonate (43.4°C), di-n-propyl peroxydicarbonate (40.5°C), diisopropyl peroxydicarbonate (40.5°C), and the like.

The amount of these polymerization initiators to be added may be selected appropriately;
Usually, the amount is 174 to 4 times the amount of α-neodecanoylperoxydiisopropylbenzene added.

The polymerization method used in the present invention may be a normal suspension polymerization method or an emulsion polymerization method, and the polymerization temperature is generally 20 to 75%.
℃, preferably in the temperature range of 30 to 60℃.

If the polymerization temperature is less than 20°C, the activity of the polymerization initiator tends to be low and the polymerization time tends to be long, while if it exceeds 75°C, the life of the polymerization initiator will be shortened, which is disadvantageous.

(Effects of the Invention) The present invention, which uses a specific polymerization initiator, has the following characteristics.

That is, in the polymerization of vinyl chloride monomers, conventional initiators (eg, AC3P) are used as polymerization initiators.

Compared to the method using IBPOlCHD), a polymer can be obtained in a higher yield, and the obtained polymer has better physical properties.

In particular, it is excellent in that the molded product has little FE and is soft.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 In a stainless steel autoclave with a capacity of 400rn1, 200ml of ion-exchanged water and 0.1ml of polyvinyl alcohol were added.
Add parts by weight and dissolve. Next, α-neodecanoylberoxymethadiisobrobylbenzene (hereinafter m-
After adding 0.05 part by weight (abbreviated as NDPB) in terms of pure product, it was cooled to -80°C or lower, and vinyl chloride monomer 1
00 parts by weight were added.

After the space in the autoclave was sufficiently replaced with nitrogen gas, it was sealed tightly. It was immersed in a constant temperature water bath kept at 50° C. for 8 hours to polymerize. For stirring, place the autoclave in a water bath for 3
This was done by rotating at 2 r, p, m. After polymerization, it is cooled and unreacted vinyl chloride monomer is removed.
Pour the obtained white powder twice into 100m7! After washing with water, it was dried under vacuum.

The yield of vinyl chloride polymer was 84% based on weight.

As a thermal stability test for the obtained vinyl chloride polymer, the coloring test shown below was conducted, and at the same time, the odor was also investigated.

Furthermore, FE was measured by the method shown below. The results are shown in Table 1.

[Colorability test and odor]

100 parts by weight of vinyl chloride polymer, 50 parts by weight of dioctyl phthalate, and 2.5 parts by weight of dibutyl tin maleate were mixed and kneaded for 10 minutes on a roll at 160°C. A sheet with a thickness of 1 mm was taken out and the degree of coloration of the sheet was determined. was visually observed. At the same time, the odor of the sheet was examined when it was taken out.

(F E) 100 parts by weight of vinyl chloride polymer, 50 parts by weight of dioctyl phthalate, and 2.5 parts by weight of dibutyl tin maleate were mixed, kneaded for 7 minutes on a roll at 160°C, and 0.1flI
Take out a sheet of ID thickness and cut the sheet) 10cmX
The number of FEOs present in an area of 10 cm was read.

Example 2 As shown in Table 1, m-NDPB was used as a polymerization initiator.
Polymerization of vinyl chloride monomers was carried out in accordance with Example 1, except that a mixture of meta and bulk forms of α-neodecanoylperoxydiisopropylbenzene (hereinafter abbreviated as NDPB) was used instead.

Example 3 As shown in Table 1, NDPBo was used as a polymerization initiator,
Polymerization of vinyl chloride monomer was carried out according to Example 1 except that BNDo and 02 parts by weight were used in addition to 03 parts by weight.

Examples 4 and 5 The same procedure as in Example 2 was followed except that OPP and NPO were used in place of BND as polymerization initiators in addition to 3 parts by weight of NDPBo and 03 parts by weight, respectively, as shown in Table 1. Polymerization was performed.

Example 6 The same procedure as in Example 1 was carried out except that 90 parts by weight of vinyl chloride monomer and 10 parts by weight of vinyl acetate monomer were used instead of 100 parts by weight of vinyl chloride monomer as shown in Table-1. Polymerization was performed.

Comparative Examples 1 to 3 Vinyl chloride was polymerized according to Example 1, except that conventionally used IBPoSAC8P and CND were used instead of NDPB as the polymerization initiator.

These results are shown in Table-1.

Comparative Example 4 As shown in Table 1, IBPOo,
Polymerization of vinyl chloride monomer was carried out according to Example 1 except that BNDo and 02 parts by weight were used in addition to 03 parts by weight.

Comparative Example 5 As shown in Table 1, CNDo, 0 was used as a polymerization initiator.
Polymerization of vinyl chloride monomer was carried out according to Example 1, except that ENDO and 02 parts by weight were used in addition to 3 parts by weight.

As mentioned above, as is clear from Table 1, in the method using conventional polymerization initiators (I BPO, AC3P, and CND) as polymerization initiators, even if they are used alone, or when the same slow-acting polymerization initiator is used, However, the polymer yield is low, FE and odor are generated in the obtained polymer, and the heat resistance (coloring property) is also poor, whereas the method of the present invention produces a polymer with good physical properties in a high yield. can get.

Claims (1)

[Claims] 1. When polymerizing vinyl chloride monomers or vinyl chloride monomers and monomers copolymerizable therewith, α-neodecanoylperoxydiisopropylbenzene is used as a polymerization initiator. A method for polymerizing vinyl chloride, characterized in that it is used. 2. When polymerizing a vinyl chloride monomer or a vinyl chloride monomer and a monomer copolymerizable therewith, (A) α-neodecanoylperoxydiisopropylbenzene and (B) 0. It is characterized by using a polymerization initiator made of at least one of peroxyester, diacyl peroxide, and peroxydicarbonate whose temperature at which the half-life in a 1 molar concentration solution is 10 hours is in the range of 40 to 65°C. Polymerization method of vinyl chloride.