JPS6023765B2 - Manufacturing method of polyvinyl chloride - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes a vinyl monomer polymer mainly composed of vinyl chloride monomer or pinyl chloride, using tertiary-amyl peroxyneodecanoate alone or as a polymerization initiator. The present invention relates to a method for producing polyvinyl chloride, which is characterized by carrying out suspension polymerization in combination with tertiary-alkyl peroxyesters or dialkyl peroxydicarbonates.

When producing a polymer by suspension polymerizing a vinyl chloride monomer or a vinyl monomer polymer mainly composed of vinyl chloride, dilauroyl peroxide (SHIOP) is used as a polymerization initiator. and tertiary-butylperoxypiparate (TBPP) have been used.

However, when such a polymerization initiator is used, there is an economical problem in that the polymerization efficiency is poor unless the 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, low-temperature active polymerization initiators have been developed, and currently low-temperature initiators such as acetylcyclohexylsulfonyl peroxide (ACSP) and diisopropyl peroxydicarbonate (mP) have been developed. Activated peroxides are used. Recently, however, particular emphasis has been placed on the quality of polymers, and a polymerization initiator that not only has high activity but also improves the quality of polymers has become desirable.

Conventional peroxyesters provide good quality polymers, but are inefficient as polymerization initiators, and peroxydicarbonates have good efficiency as polymerization initiators, but are difficult to produce high quality polymers. As a result of intensive research to find a polymerization initiator that is efficient as a polymerization initiator and can provide high-quality polymers, the inventors found that tertiary-amyl peroxyneodecanate fully satisfies these requirements. This discovery led to the present invention.

That is, the polymerization initiator used in the present invention has many excellent characteristics as follows. [1} Although it is active as a polymerization initiator, it has excellent catalyst sustainability.

'2} The obtained polymer has very good thermal stability and is hardly colored when processed into a film.

'3} By using it in combination with other polymerization initiators, especially dialkyl peroxydicarbonates, the polymerization cycle can be shortened compared to when used alone, and a polymer with good thermal stability can be obtained.

[4] Compared to when other polymerization initiators are used, there is less scale adhesion and fewer fish eyes.

For suspension polymerization in the present invention, generally known methods are applied, except for the use of a novel polymerization initiator.

The amount of polymerization initiator used is generally 0.001 to 0.5 parts by weight, preferably 0.001 to 0.5 parts by weight, based on 10 parts by weight of monomers.
．． 0.005 to 0.2 parts by weight. If the amount of the polymerization initiator used is less than 0.001 parts by weight, the polymerization rate and polymerization rate will decrease and the polymerization will be incomplete; if it is more than 0.5 parts by weight, it will be difficult to control the reaction, and the resulting polymer will be Quality deteriorates. The present invention uses a vinyl chloride monomer or a vinyl monomer mixture mainly composed of vinyl chloride as a starting material. A mixture of vinyl and a pinyl monomer copolymerizable with vinyl is used.

Examples of vinyl monomers that can be copolymerized with vinyl chloride include styrene, vinyl acetate, acrylic esters,
Examples include alkyl vinyl ethers, methacrylic acid esters, vinylidene chloride, and monoolefins. The tertiary-amyl peroxyneodecanoate used in the present invention can be obtained in good yield by, for example, reacting tertiary-amyl peroxide and neodecanoyl chloride in the presence of an alkali. Can be done.

As is clear from the names, the tertiary-amylperoxyneodecanoate used in the present invention is, for example, a compound having the following structures (■ to ■), and commercially available products are these compounds (■ to ■). It is a mixture of compounds.

The polymerization initiator used in the present invention can be used alone or as a tertiary-alkyl peroxyester having a half-life of 1 hour in a 0.2 molar solution in trichloroethylene at a temperature between 20 and 6500°C. Good results can also be obtained when used in combination with at least one selected from dialkyl peroxydicarbonates and dialkyl peroxydicarbonates.

In the case of combined use, the blending ratio of each polymerization initiator may be appropriately selected. Examples of tertiary-alkyl peroxyesters include tertiary-butylperoxyneodecanoate and tertiary-butylperoxypiparate, and examples of dialkylperoxydicarbonates include di-butylperoxyneodecanoate and tertiary-butylperoxypiparate. Examples include secondary butyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, and diisopropyl peroxydicarbonate. The process of the invention is carried out by suspension polymerization, generally using methods known per se.

The polymerization temperature is generally 20-7500, preferably 30-7500
It is 6500. If the polymerization temperature is below 20 qo, the reaction time will be long, while if it is above 7,500 qo, the polymerization initiator will be consumed in the early stage of polymerization, and late stage polymerization will hardly occur. The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto. Examples 1-3, Comparative Examples 1-
2 Suspend deionized water, polymerization initiator, and polyvinyl alcohol as shown in Table 1 in a stainless steel autoclave, evacuate it with a vacuum pump, and then charge vinyl chloride monomer and incubate at 58 qo for 7.5 hours. Turbid polymerization was carried out.

Table 1 Note 1) The amount added is in parts by weight.

Note 2) The amount of initiator addition is based on pure product.

These results show that the method for producing a polymer using tertiary-amyl peroxyneodecanoate of the present invention results in less polymer adhesion to the reactor wall during polymerization than when diisopropyl peroxydicarbonate is used. In addition, the sustainability of the initiator and the yield of the polymer do not change much, and compared to the case of using tertiary-butyl peroxyneodecanoate, the sustainability of the initiator is excellent and the yield of the polymer is good. Recognize. In addition, by using it in combination with other polymerization initiators, especially dialkyl peroxydicarbonates, the polymerization time can be shortened and a polymer with good thermal stability can be obtained. As a thermal stability test of the obtained polymer, vinyl chloride polymer 100
After mixing, add 50 parts of dioctyl phthalate, 0.3 parts of barium stearate, and 0.5 parts of cadmium stearate, and then knead with a 15,000 roll for 20 minutes and visually observe the degree of coloration of the film to determine the thermal stability. A comparison was made.

The results were as shown in Table-2. Table 12 As is clear from this, the polymers obtained by suspension polymerization using the polymerization initiator of the present invention alone or in combination with other polymerization initiators have almost no coloration and do not adhere to the walls of the reactor. It is recognized that the amount is small and that it has excellent thermal stability.

Next, Table 3 shows a comparison of the half-lives of tertiary-amyl peroxyneodecanoate used in the present invention and known polymerization initiators. Table 3 Note: Half-life is measured at a concentration of 0.2M in trichloroethylene.

As seen in Table 3, the polymerization initiator used in the present invention is more active at lower temperatures than conventional polymerization initiators, and Table 1
As shown in Table 2, the obtained polymer has excellent durability and thermal stability as shown in Table 2.

Claims (1)

[Claims] 1. A method characterized in that a vinyl chloride monomer or a vinyl monomer mixture mainly composed of vinyl chloride is subjected to suspension polymerization using a polymerization initiator containing tertiary-amyl peroxyneodecanoate. A method for producing polyvinyl chloride.