JPH03296504A - Polymerization initiator and preparation of vinyl compound using same - Google Patents

Abstract

PURPOSE:To effectively prepare a polymer reduced in coloration and odor by polymerizing a vinyl compd. using an org. peroxide having a specific structure as a polymn. initiator. CONSTITUTION:An alkyl perester of formula 1 (wherein R is a 2-5C linear or branched aliph. hydrocarbon group or an alicyclic hydrocarbon group; and R1, R1, and R3 are each a 1C or higher linear or branched aliph. hydrocarbon group provided that the sum of the numbers of carbon atoms of R1, R2, and R3 is 7 or 11) is used as a polymn. initiator to polymerize a vinyl compd. The polymn. may be conducted in a usual way provided that the polymn. initiator is used. Another initiator may be used together to make the polymn. rate uniform.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a polymerization initiator and a vinyl compound such as styrene, ethylene, vinyl chloride, (meth)acrylic acid ester, particularly vinyl chloride alone or mainly composed of vinyl chloride. The present invention relates to a method for polymerizing a vinyl compound using a polymerization initiator having a specific structure in producing a polymer from a vinyl monomer mixture.

[Conventional technology]

Conventionally, when polymerizing vinyl chloride monomers, dilauroyl peroxide (LPO), azobisisobutyronitrile (AIBN), and the like have been used. However, these polymerization initiators had economical problems in that they had to be used at relatively high temperatures (the polymerization efficiency was poor, and the polymerization would not be completed unless they were used in a fairly large amount. Oxydicarbonate) (IPP), G2-
Ethylhexyl peroxydicarbonate (EHP) and acetylcyclohexylsulfonyl peroxide (A
Low temperature active peroxides such as C3P) have come into use.

However, these low-temperature active peroxides either give a relatively high polymerization rate or are very unstable with respect to temperature, posing problems in handling hazards.

Another drawback is that the resulting polymer is colored.

In particular, recently there has been a preference for non-colored polymers, and the problem of coloring of polymers has become a big problem. Furthermore, with the increase in demand, shortening the polymerization time has become an urgent issue, and increasing the amount of these polymerization initiators added has been considered. Ta.

To improve these, it has been proposed to use alkyl peroxy esters such as t-butylperoxyneodecanoate (TBPND) and α-cumylperoxyneodecanoate (CPND) alone or in combination. ing.

[Invention or problem to be solved]

When polymerizing vinyl chloride monomers, if alkyl peroxy esters such as TBPND or CPND are used alone or in combination with other polymerization initiators as polymerization initiators, even if the amount added is increased, In the case of TBPND, a polymer with less coloring can be obtained, but it is economically disadvantageous because its activity is slightly inferior to that of conventional low-temperature active peroxides, so it must be used in a larger amount. In addition, in the case of CPND, the decomposition products give a very strong and unique odor to the polymer, so there are disadvantages such as limited use. No polymerization initiator has been found to date.

[Means to solve the problem]

The present inventors have conducted extensive research to find a polymerization initiator that is active at low temperatures, is safer in handling, provides a good polymer color, and has no odor, and has found a polymerization initiator represented by general formula (I). The inventors have discovered that an organic peroxide having a specific structure can fully satisfy these requirements, and have arrived at the present invention.

General Formula (I) In the formula, R: a straight chain or branched aliphatic hydrocarbon having 2 to 5 carbon atoms.

R11R2, R3: A linear or branched aliphatic hydrocarbon having 1 or more carbon atoms, and the total number of carbon atoms of R, R2, R, is 7 or 11°. In other words, the polymerization initiator in the present invention is as follows. It has many excellent features.

1) As a polymerization initiator, it is active at low temperatures and has excellent catalyst sustainability.

2) Low temperature activity shortens polymerization time and increases polymer productivity.

3) It has lower sensitivity to temperature than AC3P and IPP,
Highly safe to handle.

4) Compared to ACSP and IPP, the obtained polymer has very good thermal stability and good hue.

Examples of the organic peroxide having a specific structure represented by general formula (I) in the present invention include t-amylperoxyneononanoate, t-hexylyloxyneononanoate,
t-heptylperoxyneonanoate, t-octylperoxyneononanoate, t-amylperoxyneotridecanoe-1, t-hexylperoxyneotridecanoate, t-heptylperoxyneotridecanoate Examples include tridecanoate and t-octylperoxyneotridecanoate.

These organic peroxides include neononatsunic acid chloride obtained from neononatsunic acid (for example, Equacid 9 manufactured by Idemitsu Petrochemical Co., Ltd.), or neotridecatuic acid chloride obtained from neotridecatuic acid (for example, Equacid 13 manufactured by Idemitsu Petrochemical Co., Ltd.), Twin acid chloride and tertiary hydroperoxide such as t-amyl hydroperoxide, t-hexyl hydroperoxide, t
It can be obtained in good yield by reacting -hebutyl hydroperoxide with -octyl hydroperoxide in the presence of an alkali.

Polymerization initiators made of these organic peroxides are safe,
From the viewpoint of usage or handling, it is used in the form of industrially pure products, diluted with solvents such as isoparaffin or toluene or plasticizers, suspended in water, or in the form of hydrated frozen flakes. .

In the present invention, an organic peroxide represented by the general formula (1) is used as a polymerization initiator, or it may be used in combination with other initiators in order to equalize the polymerization reaction rate.

Such other initiators include peroxydicarbonates such as IPP, di-S-butylperoxydicarbonate (5BP), and EHP, peroxyesters such as TBPND, t-butylperoxypivalate (TBPP), and CPND. , diisobutyryl peroxide (IBP), dilauroyl peroxide (LPO)
, diacyl peroxides such as dinonanoyl peroxide (INF), AC3P, and azo compounds.

The polymerization method in the present invention may be any conventional method except for using the polymerization initiator of the present invention.

The amount of the polymerization initiator used varies depending on the polymerization temperature, the heat removal capacity of the polymerization machine, and, in the case of copolymerization, the type of comonomer used.
0.001 to 2.0 parts by weight, more preferably 0.005 to 1.0 parts by weight. If the amount of the polymerization initiator used is less than 0.001 part by weight, the polymerization rate and polymerization rate may decrease and the polymerization may be incomplete.
If it exceeds 0 parts by weight, it may become difficult to control the polymerization rate. The polymerization temperature is preferably 20 to 75°C, more preferably 30 to 70°C. If the temperature is below 20°C, the reaction time will be long, and if the temperature is above 75°C, the polymerization initiator will be consumed in the initial stage of polymerization, making it difficult to reach a good polymerization rate.

In addition to vinyl chloride, monomers that can be used in the present invention include other monomers copolymerizable with vinyl chloride, such as ethylene,
Olefins such as propylene, l-butene, and -hexene, acrylic acid or its esters, methacrylic acid or its esters, fumaric acid or its esters, maleic acid or its esters, vinyl acetate, vinyl propionate, alkyl Vinyl compounds such as vinyl ethers and mixtures thereof can be used together.

〔Example〕

The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto. Note that the amount of the initiator added is expressed in terms of pure product.

Example 1 Polymerization was carried out using a stainless steel autoclave according to the following recipe.

Distilled water 125 parts by weight Polyvinyl alcohol 0.125 parts by weight Vinyl chloride monomer
100 parts by weight Type of initiator Table 1 Amount of initiator added Table 1 Polymerization temperature 42°C Table 1 TOPNTD: t-octyl oxyneodolipcaate TOPNN: t-octyl extended oxyneononanoate CPND: α-cumyl Oxyneodecanoate EHP Nidi-2-ethylhexyl oxydicarbonate Example 2 Polymerization was carried out at EO°C near IQ to Jika Naka J (Table 2) Example 3 Obtained according to Example 1.2 The polymer slurry is washed, dehydrated,
It was dried to obtain a vinyl chloride polymer. 100 parts by weight of this polymer, 30 parts by weight of dioctyl phthalate, and 2.5 parts by weight of dibutyltin maleate were kneaded for 5 minutes at 160°C to form a 0.5 mm sheet, and a sensory test during kneading was conducted. The yellowness was determined by odor comparison and white plate reflection method using a color difference meter, and the results are shown in Table 3. Furthermore, yellowness Y
The correlation between 1 and the hue of the polymer is as follows.

0PNTD APNTD APNN C3P BPND t-hexyloxyneotridecanoate t-amylperoxyneotridecanoate t-amylperoxyneonanoate acetyl sulfonyl peroxide t-butyloxyneotridecanoate table 3 NO: Example 1 2 Experiments N.

Example 4 100 parts by weight of distilled water, 0.1 part by weight of polyvinyl alcohol, and 1 part by weight of t-octylperoxyneotridecate were placed in a stainless steel autoclave, and after removing the air inside with a vacuum pump, 90 parts by weight of vinyl chloride was added. Parts by weight, 1
- 10 parts by weight of hexane were injected. Polymerization temperature 45°C
The reaction was continued until the internal pressure reached 3 kg/cnfG pressure.

After the reaction is completed, the polymer slurry is taken out, washed, dehydrated,
It was dried to obtain a vinyl chloride copolymer.

Knead for 10 minutes at 150°C according to Example 3,
A 0.5 mm sheet was produced. There was a slight odor that could be felt during kneading. Moreover, the yellowness was 3.9.

A similar test was conducted using α-cumyl peroxy neodecanoate instead of t-octyl peroxy neotridecanoate. The yellowness was 3.7, and there was a strong odor of acetophenone, which is a decomposition product of α-cumyl peroxyneodecanoate.

As is clear from the results of Example 1.2, the organic peroxides of the present invention are low temperature active organic peroxides such as EHP,
It can be seen that the activity is the same or higher than AC3P or CPND, and the polymerization time can be shortened. In addition, from the results of Example 3.4, the polymer made from the organic peroxide with this specific structure is superior to the polymer obtained using the conventional low-temperature active organic peroxide in terms of odor and hue. I can see why it's so much better.

Next, Table 4 shows the half-lives of the specific structure peroxide used in the present invention and the known peroxides. Measurement is in benzene, 0
．． A 2 molar concentration was used. As seen in Table 4, it can be seen that the polymerization initiators used in the present invention are low-temperature active.

〔Effect of the invention〕

As shown in the examples, according to the present invention, it is possible to efficiently obtain a polymer with little coloration and low odor, which was previously impossible, and the industrial value is extremely large.

Claims (2)

[Claims] (1) A polymerization initiator characterized by containing an alkyl perester represented by the following general formula (I). General Formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ In the formula, R: Straight chain or branched aliphatic hydrocarbon with 2 to 5 carbon atoms, or alicyclic hydrocarbon. R_1, R_2, R_3: A straight chain or branched aliphatic hydrocarbon with one carbon number on one side, and the total number of carbon atoms of R_1, R_2, and R_3 is 7 or 11. (2) A method for polymerizing a vinyl compound, which comprises using an alkyl perester represented by the general formula (I) according to claim 1.