JP3388528B2 - Method for producing vinyl polymer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl polymer such as a vinyl chloride polymer, vinylidene chloride polymer and vinyl acetate polymer, which can be obtained in good quality by shortening the polymerization time. The present invention relates to a method for producing a polymer.

[0002]

2. Description of the Related Art In recent years,
When producing vinyl polymers such as vinyl chloride polymers, vinylidene chloride polymers and vinyl acetate polymers, the polymerization process is performed in order to produce these polymers with high productivity while maintaining quality. There is an increasing demand for manufacturing in a short reaction time.

For example, a polymerization initiator having a higher polymerization reaction rate is used for the purpose of reaction in a short time when polymerizing a vinyl chloride monomer.

As such a polymerization initiator, tert
-Butyl peroxypivalate, tert-butyl peroxy neoheptanoate, tert-butyl peroxy neodecanoate, tert-hexyl peroxy neodecanoate, di-2-ethylhexyl peroxydicarbonate, di-sec-butyl peroxydicarbonate 2,2'-azobis-2,4-dimethylvaleronitrile, 3,5,5-trimethylhexanoyl peroxide, cumyl peroxyneodecanoate, isobutyryl peroxide, and the like.

However, the above-mentioned tert-butyl peroxypivalate, tert-butyl peroxy neoheptanoate, tert-butyl peroxy neodecanoate, tert-hexyl peroxy neodecanoate, 2,2'-azobis-2,4. -Dimethylvaleronitrile, 3,5,5-trimethylhexanoyl peroxide, etc. maintain their activity until the middle stage of polymerization and the polymerization reaction rate is kept high, but after the polymerization reactor internal pressure starts to decrease at the latter stage of polymerization, The reaction rate significantly decreases, the polymerization time becomes long, and the sufficient effect of shortening the polymerization time cannot be obtained. Further, di-2-ethylhexyl peroxydicarbonate, di-sec-butyl peroxydicarbonate and the like, the polymerization reaction rate is maintained relatively high throughout the polymerization, but the coloring property of the polymer molded article is poor, The activity of peroxyneodecanoate is maintained until the middle stage of the polymerization, and the polymerization reaction rate is kept high, but after the internal pressure of the polymerization reactor starts to decrease in the latter stage of the polymerization, the reaction rate decreases remarkably and the polymerization time becomes long. It is not possible to obtain a sufficient effect of shortening the polymerization time, and because it has a phenyl group as a molecular structure, the product is not suitable for the medical field and there is a problem that odor is generated during molding of the polymer. It was

Therefore, when a vinyl polymer is produced,
There has been a demand for a method for producing a vinyl-based polymer, which is excellent in quality, particularly in colorability of polymer molded articles, hygiene such as odor, maintains a high polymerization reaction rate throughout polymerization, and enables a short-time reaction.

The present invention has been made in view of the above circumstances, and includes a vinyl chloride polymer, a vinylidene chloride polymer,
An object of the present invention is to provide a method for producing a vinyl-based polymer, which is excellent in quality when producing a vinyl-based polymer such as a vinyl acetate-based polymer, and can produce these polymers in a short reaction time. .

[0008]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of earnest studies to achieve the above object, the present inventor has found that vinyl chloride monomer, vinylidene chloride monomer, vinyl acetate monomer In the case of polymerizing a vinyl-based monomer such as 1, 2, 1, 2, or 3 represented by the following general formula (1) as a polymerization initiator
By using a 2-tetramethylpropyl peroxy ester compound, it is possible to maintain a high polymerization reaction rate throughout the polymerization, and particularly, the polymerization reaction rate after the internal pressure of the polymerization vessel starts to drop in the latter half of the polymerization. It can be maintained at a very high level and a short reaction time is possible.
The inventors have found that a high-quality vinyl polymer molded product excellent in colorability and hygiene can be obtained, and can effectively solve the above-mentioned conventional problems, and have accomplished the present invention.

[0009]

[Chemical 2] (In the formula, R ¹ , R ² and R ³ represent the same or different linear alkyl groups having 1 to 9 carbon atoms.)

The present invention will be described in more detail below. In the present invention, 1,1,2,2-tetramethylpropylperoxy ester represented by the following general formula (1) is used when polymerizing a vinyl monomer. A compound is added and polymerized.

[0011]

[Chemical 3] (In the formula, R ¹ , R ² and R ³ represent the same or different linear alkyl groups having 1 to 9 carbon atoms.)

The compound of formula (1) is a novel substance, and R ¹ , R ² and R ³ are, as described above, the same or different linear alkyl groups having 1 to 9 carbon atoms, Specific examples include a methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, and n-nonyl group. , R ¹ , R ² and R ³ have a total carbon number of 3 to 11, the viscosity of the resulting compound can be kept low. It is preferable in terms of handleability such as easy press-fitting into. Furthermore, it is more preferable that the total number of carbon atoms of R ¹ , R ² and R ³ is 3 to 8.

The 1,1,2,2-tetramethylpropyl peroxy ester compound has a 10-hour half-life temperature (polymerization initiator becomes 1/2 in 10 hours) in a benzene solution of 0.1 mol / l. The temperature is preferably 30 to 50 ° C.

The 1,1,2,2-tetramethylpropyl peroxy ester compound is 1,1,2,2.
-Tetramethylpropyl peroxypivalate, 1,
1,2,2-Tetramethylpropylperoxy neoheptanoate, 1,1,2,2-tetramethylpropyl peroxy neodecanoate and the like are preferably used.

The above 1,1,2,2-tetramethylpropyl peroxy ester compound is produced by the following method. That is, first, a known method (for example, Jour
nal of the American Chemi
cal Society / 89: 7 / March 2
1,1,2,2-tetramethylpropyl alcohol synthesized in 9,1967) is treated with an aqueous hydrogen peroxide solution and concentrated sulfuric acid to obtain an alkylhydroperoxide represented by the following structural formula (2). This reaction is an exothermic reaction and is preferably carried out at room temperature.

[0016]

[Chemical 4]

Next, the alkyl hydroperoxide of the above formula (2) is converted into an acid chloride represented by the following general formula (3) (for example, pivalic acid chloride, neohexanoic acid chloride, neoheptanoic acid chloride, neodecanoic acid chloride,
(Neotridecanoic acid chloride, etc.) in the presence of a base catalyst such as an aqueous solution of potassium hydroxide, while maintaining the reaction temperature at 20 ° C. or lower in an organic solvent such as benzene, toluene, xylene, n-hexane, and then neutralization. By washing with water and dehydrating the organic layer with anhydrous sodium sulfate, the 1,1,2,2-tetramethylpropylperoxyester compound represented by the above general formula (1) can be obtained.

[0018]

[Chemical 5] (In the formula, R ¹ , R ² and R ³ have the same meanings as described above.)

The peroxyester compound of the formula (1) is used as a polymerization initiator in the production of a vinyl polymer, and the addition amount of the compound of the formula (1) is 100 wt. The amount is 0.001 to 5 parts by weight, and particularly 0.01 to 0.3 parts by weight.

In the present invention, the vinyl-based monomer used to obtain the vinyl-based polymer is vinyl chloride,
Examples thereof include vinylidene chloride, vinyl acetate, styrene, acrylonitrile, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, butadiene, and chloroprene. These may be used alone or in combination of two or more. it can. Among these, vinyl chloride-based polymers, vinylidene chloride-based polymers, and vinyl acetate-based vinyl chloride-based polymers, vinylidene chloride-based monomers, vinyl acetate-based monomers, and vinyl acetate-based polymers are used. It is effective when producing a polymer.

The vinyl chloride-based polymer may be a vinyl chloride-based homopolymer or a copolymer of vinyl chloride and another vinyl-based monomer (usually, vinyl chloride is 50% by weight).
Or more, preferably 70% by weight or more). Examples of the comonomer copolymerized with vinyl chloride include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-
Α-olefins such as decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene; maleic acid; vinyl esters such as vinyl acetate; vinyl ethers such as lauryl vinyl ether and isobutyl vinyl ether; maleic anhydride; vinylidene chloride and the like. It is illustrated.

As the vinylidene chloride-based polymer, in addition to vinylidene chloride homopolymer, a copolymer of vinylidene chloride and another vinyl-based monomer (usually, vinylidene chloride is 50
% Or more, preferably 70% or more). Examples of the comonomer to be copolymerized with vinylidene chloride include the above-mentioned comonomers excluding vinylidene chloride itself.

As the vinyl acetate-based polymer, in addition to vinyl acetate homopolymer, a copolymer of vinyl acetate and other vinyl-based monomer (usually, vinyl acetate is 50% by weight or more, preferably 70% by weight). Above) is included. Examples of the comonomer to be copolymerized with vinyl acetate include the above-mentioned comonomers excluding vinyl acetate itself.

When the vinyl monomer is polymerized as described above, the compound of the formula (1) is used as a polymerization initiator as described above. In this case, the compound of the formula (1) is used alone. Although it is effective for a short time polymerization reaction even when used in the above, by using at least one other polymerization initiator different in activity, the polymerization reaction rate in the whole polymerization process is made uniform and the polymerization time is further increased. It can be shortened. That is, as a component (a), a polymerization initiator having a 10-hour half-life temperature in a benzene solution of 0.1 mol / l of 30 ° C. or higher and lower than 40 ° C., and (b) a benzene solution of 0.1
10 hour half-life temperature in mol / l is preferably 4
0 ° C to 70 ° C, more preferably 40 ° C to 60 ° C
By using the following polymerization initiators in combination, it is possible to obtain excellent effects that cannot be obtained by the conventional combination of polymerization initiators.

Here, as the component (a) (10-hour half-life temperature is 30 ° C. or higher and lower than 40 ° C.), specifically, isobutyryl peroxide (10-hour half-life temperature 32.5 ° C.,
The same shall apply hereinafter), etc., peroxydicarbonate-based organic peroxides such as cumyl peroxyneodecanoate (36.6 ° C.) and peroxydicarbonate-based organic peroxides such as diallyl peroxydicarbonate. Is mentioned.

Component (b) (10-hour half-life temperature is 40 ° C.
Specifically, diacyl organic peroxides such as 3,5,5-trimethylhexanoyl peroxide (59.5 ° C.) and lauroyl peroxide (62.0 ° C.), tert-butyl Peroxypivalate (55.0 ° C.), tert-butyl peroxy neoheptanoate (49.7 ° C.), tert-butyl peroxy neodecanoate (46.5 ° C.), tert-hexyl peroxy neodecanoate (44) Peroxydicarbonate-based organic peroxides such as di-sec-butylperoxydicarbonate (45.0 ° C) and di-2-ethylhexylperoxydicarbonate (43.5 ° C). Organic peroxide, 2,
2'-azobisisobutyronitrile (65.0 ° C),
Examples thereof include azo compounds such as 2,2′-azobis-2,4-dimethylvaleronitrile (51.0 ° C.), and among these, 3,5,5-trimethylhexanoyl peroxide and tert-butylperoxyneo Heptanoate,
tert-butyl peroxy neodecanoate, di-2
-Ethylhexyl peroxydicarbonate is preferably used.

Here, the 1,1,2,2-tetramethylpropylperoxyester compound is used as at least one of the component (a) and the component (b), and the component (a) and the component (b) are used. Those having a 10-hour half-life temperature difference from the components of preferably 2 ° C. or more, more preferably 5 ° C. or more are suitably used. If this 10-hour half-life temperature difference is less than 2 ° C., the polymerization reaction rate in the entire polymerization process may be made uniform and the polymerization time may not be shortened.

In this case, the amount of the component (a) is 0.001 to 0.5 part by weight, preferably 0.01 to 0.3 part by weight, based on 100 parts by weight of the total charged monomers. Is 0.001 to 0.5 parts by weight, preferably 0.01 to 0.3 parts by weight, based on 100 parts by weight of all charged monomers, and the total addition of the components (a) and (b). The amount is 0.5 parts by weight, preferably 0.1 parts by weight, based on 100 parts by weight of all charged monomers.
It is preferably used within a range not exceeding 3 parts by weight. As a method of addition, a method of charging the monomer and then diluting it with a solvent, or injecting it as an aqueous emulsion into the reaction system with a pump can be employed.

In the present invention, the polymerization method is preferably used for radical polymerization such as suspension polymerization, emulsion polymerization, solution polymerization and bulk polymerization, but the suspension polymerization method is particularly preferable.

A known method can be adopted as the suspension polymerization method, and the polymerization temperature is preferably 30 to 70 ° C, more preferably 40 to 65 ° C. The suspending agents used may be those conventionally used in general, for example, cellulose derivatives such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, water-soluble or oil-soluble partially saponified polyvinyl alcohol, and acrylic acid copolymer. Water-soluble polymers such as coalesce and gelatin are mentioned. These may be used alone or in combination of two or more, and together with the above suspension, a nonionic emulsifier such as sorbitan monolaurate, sorbitan trilaurate, glycerin tristearate, ethylene oxide propylene oxide block copolymer, Anionic emulsifiers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene glycerin oleate, and sodium lauryl sulfate can be used alone or in combination of two or more. The amount of suspension agent is vinyl chloride monomer 1
It is appropriately added within the range of 0.02 to 0.2 parts by weight with respect to 00 parts by weight.

If necessary, a polymerization regulator, a chain transfer agent, which is appropriately selected in the polymerization of the vinyl chloride-based monomer,
It is also optional to add a pH adjusting agent, a gelling adjusting agent, an antistatic agent, a crosslinking agent, a filler, a polymer scale adhesion preventing agent and the like.

[0032]

EFFECT OF THE INVENTION According to the present invention, 1,1,2,2 of the formula (1) is used as a polymerization initiator for polymerizing a vinyl monomer.
-By using the tetramethylpropyl peroxy ester compound, the polymerization reaction rate in the entire polymerization process can be made uniform, the polymerization time can be shortened, and a polymer molded article excellent in coloring and hygiene can be obtained. it can.

[0033]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1] Using a stainless steel polymerization vessel with an internal volume of 2 liters and an internal temperature control coil, 1250 g of deionized water, 0.36 g of water-soluble partially saponified polyvinyl alcohol and 0 water-soluble cellulose ether were placed in the polymerization vessel. .24 g
Was charged with 50 g of deionized water in which
0 mmHgabs. After degassing until 405g, vinyl chloride monomer (VCM) 405g was charged and heated water was passed through the coil while stirring to raise the internal temperature until it reached 57 ° C. At this point, 1.62 g (0. 0%) of 1,2,2-tetramethylpropylperoxypivalate (TMPV) having a concentration of 25% was previously obtained from the isoparaffin solution.
(100 wt% vs. VCM) was injected with a syringe to start the polymerization, and at the same time, cooling water was passed through the coil to continue the polymerization while maintaining the internal temperature at 57 ° C. (polymerization temperature).

When the internal pressure of the polymerization vessel dropped to 4.5 kgf / cm ² , 0.225 g of a 20% methanol solution of bisphenol A was injected with a syringe to stop the polymerization and recover the exhaust gas (unreacted monomer). Then, the vinyl chloride polymer slurry is taken out, dehydrated and dried to obtain 366 g (yield 9
0.4%) of vinyl chloride polymer was obtained.

[Embodiment 2] 1, 1, in Embodiment 1
2,2-tetramethylpropyl peroxypivalate (TMPV) 0.100% by weight, instead of VCM, T
MPV 0.080 wt% vs. VCM and 1,1,2,2-tetramethylpropyl peroxyneodecanoate (TM
ND) 0.026 wt% vs. VCM (the sum of both initiators is
A vinyl chloride polymer was obtained by following the procedure according to Example 1 except that the same amount as TMPV in Example 1) was added.

[Embodiment 3] 1, 1 in Embodiment 1
2,2-tetramethylpropyl peroxypivalate (TMPV) 0.100% by weight, instead of VCM, T
MPV 0.038% by weight to VCM and cumyl peroxyneodecanoate (CND) 0.030% by weight to VCM were added, and the polymerization was stopped when the internal pressure of the polymerization vessel dropped to 5.5 kgf / cm ^2. A vinyl chloride polymer was obtained by following the procedure according to Example 1.

[Embodiment 4] 1, 1 in Embodiment 1
2,2-Tetramethylpropylperoxypivalate (TMPV) 0.100% by weight instead of VCM,
1,1,2,2-Tetramethylpropylperoxyneodecanoate (TMND) 0.070 wt% to VCM was added, the polymerization temperature was 54 ° C, and the internal pressure of the polymerization vessel was 4.2k.
Except that the polymerization was stopped at the time when it dropped to gf / cm ² ,
According to the procedure according to Example 1, a vinyl chloride polymer was obtained.

[Embodiment 5] 1, 1 in Embodiment 1
2,2-Tetramethylpropylperoxypivalate (TMPV) 0.100% by weight instead of VCM,
0.020% by weight of 1,1,2,2-tetramethylpropyl peroxy neodecanoate (TMND) vs. VCM and tert-butyl peroxy neodecanoate (BN
D) A vinyl chloride polymer was prepared according to the procedure of Example 1 except that 0.050% by weight of VCM was added and the polymerization was stopped when the internal pressure of the polymerization vessel dropped to 6.4 kgf / cm ^2. Obtained.

[Embodiment 6] 1, 1 in Embodiment 1
2,2-Tetramethylpropylperoxypivalate (TMPV) 0.100% by weight instead of VCM,
0.020% by weight of 1,1,2,2-tetramethylpropyl peroxy neodecanoate (TMND) vs. VCM and tert-butyl peroxy neodecanoate (BN
D) 0.090% by weight of VCM was added, and the polymerization temperature was adjusted to 5
A vinyl chloride polymer was obtained by following the procedure according to Example 1 except that the polymerization was stopped at 1 ° C. and the internal pressure of the polymerization vessel dropped to 6.4 kgf / cm ² .

[Embodiment 7] 1, 1 in Embodiment 1
2,2-Tetramethylpropylperoxypivalate (TMPV) 0.100% by weight instead of VCM,
1,1,2,2-Tetramethylpropylperoxyneoheptanoate (TMHP) 0.090 wt% vs. VCM
And vinyl acetate monomer total weight 405g (weight ratio 9 /
1) to vinyl chloride-acetic acid according to the procedure of Example 1 except that the polymerization temperature was 57 ° C. and the polymerization was stopped when the internal pressure of the polymerization vessel dropped to 4.2 kgf / cm ^2. A vinyl copolymer was obtained.

[Comparative Example 1] 1, 1 in Example 1
Instead of 2,2-tetramethylpropyl peroxypivalate (TMPV), tert-butyl peroxy neodecanoate (BND) 0.113 wt% vs. VCM
A vinyl chloride polymer was obtained by following the procedure according to Example 1 except that (the same mole as TMPV in Example 1) was added.

Comparative Example 2 1, 1 in Example 1
Instead of 2,2-tetramethylpropyl peroxypivalate (TMPV), tert-butyl peroxy neoheptanoate (BNH) 0.094 wt% vs. VC
A vinyl chloride polymer was obtained according to the procedure of Example 1 except that M (equal moles of TMPV in Example 1) was added.

[Comparative Example 3] 1, 1 in Example 1
Instead of 2,2-tetramethylpropyl peroxypivalate (TMPV), 0.160% by weight of di-2-ethylhexyl peroxydicarbonate (EHP) vs. V
A vinyl chloride polymer was obtained by following the procedure according to Example 1 except that CM (the same mole as TMPV in Example 1) was added.

[Comparative Example 4] 1, 1, in Example 3
Instead of 2,2-tetramethylpropyl peroxypivalate (TMPV), tert-butyl peroxy neodecanoate (BND) 0.043 wt% vs. VCM
A vinyl chloride polymer was obtained by following the procedure according to Example 3 except that (the same mole as TMPV in Example 3) was added.

[Comparative Example 5] 1, 1, in Example 3
Instead of 2,2-tetramethylpropyl peroxypivalate (TMPV), di-2-ethylhexyl peroxydicarbonate (EHP) 0.061 wt% vs. V
A vinyl chloride polymer was obtained by following the procedure according to Example 3 except that CM (the same mole as TMPV in Example 3) was added.

[Comparative Example 6] 1, 1, in Example 3
Instead of 2,2-tetramethylpropyl peroxypivalate (TMPV), 0.041 wt% of di-sec-butylperoxydicarbonate (SBP) vs. VCM
A vinyl chloride polymer was obtained by following the procedure according to Example 3 except that (the same mole as TMPV in Example 3) was added.

[Comparative Example 7] 1, 1 in Example 4
Instead of 2,2-tetramethylpropylperoxyneodecanoate (TMND), 0.075 wt% cumylperoxyneodecanoate (CND) to VCM (equimolar to TMND in Example 4) was added, A vinyl chloride polymer was obtained by following the procedure according to Example 4 except that the polymerization was stopped when the internal pressure of the polymerization vessel dropped to 6.6 kgf / cm ² .

[Comparative Example 8] 1, 1, in Example 5
2,2-Tetramethylpropyl peroxynedecanoate (TMND) 0.020 wt% vs. VCM and tert-
Butyl peroxy neodecanoate (BND) 0.05
Instead of 0 wt% VCM, tert-butyl peroxyneodecanoate (BND) 0.067 wt% V
A vinyl chloride polymer was obtained by following the procedure according to Example 5 except that CM (equal mol of the total amount of TMND and BND in Example 5) was added.

[Comparative Example 9] 1, 1 in Example 5
2,2-Tetramethylpropylperoxyneodecanoate (TMND) was replaced with 0.020% by weight cumylperoxyneodecanoate (CND) to VCM (equal moles as TMND in Example 5). A vinyl chloride polymer was obtained by following the procedure according to Example 5.

[Comparative Example 10] 1, 1 in Example 6
Instead of 2,2-tetramethylpropylperoxy neodecanoate (TMND), 0.020 wt% of cumyl peroxy neodecanoate (CND) to VCM (equal moles as TMND in Example 6) was added. A vinyl chloride polymer was obtained by following the procedure according to Example 6.

[Comparative Example 11] 1, 1 in Example 7
Instead of 2,2-tetramethylpropylperoxy neoheptanoate (TMHP), 0.090 wt% tert-butylperoxy neodecanoate (BND) vs. total weight of VCM and vinyl acetate monomer (in Example 7). A vinyl chloride-vinyl acetate copolymer was obtained according to the procedure of Example 7, except that TMHP was added in an equimolar amount.

[Comparative Example 12] 1, 1 in Example 7
Instead of 2,2-tetramethylpropylperoxy neoheptanoate (TMHP), 0.139% by weight of di-2-ethylhexyl peroxydicarbonate (EHP) versus the total weight of VCM and vinyl acetate monomer (Example 7
A vinyl chloride-vinyl acetate copolymer was obtained by following the procedure according to Example 7 except that (TMHP in 1 mol) was added.

The initial coloring properties of the vinyl chloride polymers obtained in Examples 1 to 7 and Comparative Examples 1 to 11 were measured. The results are shown in Tables 1 and 2.

Initial Colorability (IC) Measuring Method 100 parts by weight of vinyl chloride polymer was mixed with 1 part by weight of tin laurate, 0.5 part by weight of cadmium stabilizer and 50 parts by weight of dioctyl phthalate, and a two roll mill was used. After kneading at 160 ° C. for 5 minutes, a sheet having a thickness of 0.8 mm was formed. Next, cut and stack this sheet, and
Put in a mold of × 4 × 1.5 cm, 160 ° C, 65-70
A measurement sample was prepared by heating and press molding at kgf / cm ² . For this measurement sample, using a photoelectric colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd.), JISZ8730 (1980)
The lightness index L in the color difference formula of the Hunter described in
The a value and the b value were measured.

However, with regard to Example 3, Comparative Example 5 and Comparative Example 6 which are vinyl chloride-vinyl acetate copolymers, 30 parts by weight of dioctyl phthalate, a roll mill kneading temperature of 120 ° C., and 4 × 4 × 0.5 cm were used. The initial colorability was measured under the same conditions except that the mold was used.

In Tables 1 and 2, "polymerization start" is the time when the polymerization initiator is added, "time until the pressure is reduced" is the time from the start of polymerization until the pressure inside the polymerization vessel starts to decrease, and "pressure reduction rate" is decreased. It is the pressure drop rate from the time when the polymerization is started to the time when the pressure inside the polymerization vessel is reached when the polymerization is stopped.

However, in Example 7, which is a copolymerization of vinyl chloride and vinyl acetate, Comparative Example 11 and Comparative Example 12, "time until pressure reduction" is zero, which is different from vinyl chloride homopolymerization. It means that the internal pressure of the polymerization vessel gradually decreased from the beginning of the polymerization initiation, and the “falling rate” is the pressure drop rate while the internal pressure of the polymerization vessel was reached from the beginning of the polymerization when the polymerization was stopped.

The relationship between the symbols of the polymerization initiators in Tables 1 and 2 and their names and the 10-hour half-life temperature is as follows.

Symbol Name 10 hours half-life temperature ^* TMPV: 1,1,2,2-tetramethylpropylper 45.7 ° C. Oxypivalate TMHP: 1,1,2,2-tetramethylpropylper 40.6 ° C. Oxy Neoheptanoate TMND: 1,1,2,2-tetramethylpropylper 39.0 ° C. Oxyneodecanoate BND: tert-butylperoxyneodecanoe 46.5 ° C. BNH: tert-butylperoxy neohepta Noe 52.1 ° C. ETP: di-2-ethylhexyl peroxy dicarbo 43.5 ° C. Nate SBP: di-sec-butyl peroxy dicarbone 45.0 ° C. CND: cumyl peroxy neodecanoate 36.6 C. * 10 hour half-life temperature is a value in a benzene solution of 0.1 mol / l.

[0061]

[Table 1]

[0062]

[Table 2]

From the results in Tables 1 and 2 (Examples 1, 4, and 7), 1,1,2,2-tetramethylpropylperoxyester compound (TMPV, which is the polymerization initiator of the present invention)
It has been found that when a vinyl-based monomer is polymerized by using (TMHP, TMND) alone, a reaction for a short time can be achieved and a polymer molded article having excellent coloring properties can be obtained.

Further, the above 1,1,2,2-tetramethylpropyl peroxy ester compound (TMPV, TMH
(P, TMND) and other polymerization initiators having different 10-hour half-life temperatures in combination (Examples 2, 3, 5, and 6), the obtained polymer was excellent as in the above. It was found that while maintaining the initial colorability, a polymerization reaction could be achieved for a short time that could not be achieved by combining conventional polymerization initiators.

[Reference Example 1] 1,1,2,2-tetrame
Production of tylpropyl peroxypivalate 300 ml equipped with stirrer, thermometer and dropping funnel
73.7 g of 50% hydrogen peroxide aqueous solution was charged into the 4-necked flask described above, stirring was started, and 51.7 g of 98% concentrated sulfuric acid was added dropwise while keeping the temperature below 20 ° C. by water cooling to prepare a mixed acid. . Next, the temperature is adjusted to 0 to 5 ° C. using an ice bath, and “Journal of the A” is set in advance.
merican Chemical Society /
89: 7 / March 29, 1967 ", a solution of 42.9 g of 1,1,2,2-tetramethylpropyl alcohol synthesized by the method described in" Dichloromethane (40 m) "
1) was slowly added dropwise with stirring. After completion of dropping, the stirring was continued for 2 hours, and then the organic layer was washed with pure water until the organic layer became neutral. After the organic layer was dehydrated with anhydrous sodium sulfate, the solvent was distilled off to obtain 47.4 g of 1,1,2,2-tetramethylpropyl hydroperoxide (the above structural formula (2)).

Then, the resulting mixture was obtained in a 100 ml four-necked flask equipped with a stirrer, a thermometer and a dropping funnel.
8 g of 1,1,2,2-tetramethylpropyl hydroperoxide was charged, and 47.7 g of a 30% aqueous potassium hydroxide solution was added and stirred and mixed. While maintaining the temperature at 0 to 5 ° C, 11.1 g of pivalic acid chloride was added dropwise with stirring, and the stirring was continued for 2 hours. The reaction solution was washed with water until it became neutral, and the organic layer was dehydrated with anhydrous sodium sulfate. As a result of analyzing the obtained compound by an iodometry method, the yield was 23.8 g and the yield was 91.7% (molar yield based on hydroperoxide).

As a result of analyzing the obtained compound,
It was found to be 1,1,2,2-tetramethylpropyl peroxypivalate. The analysis results are shown below.

Further, a solution of the obtained compound in benzene was added.
10-hour half-life temperature at 1 mol / l is 45.7 ° C,
The amount of active oxygen was 7.40%.

[0069]

[Chemical 6] ¹ H-NMR (acetone-d6) H δ (ppm) a 1.01 (s, 9H) d 1.26 (s, 6H) g 1.23 (s, 9H) ¹³ C-NMR (acetone-d6) C δ (ppm) a 26.07 b 38.30 c 86.64 d 20.80 e 175.10 f 39.32 g 27.45 IR (neat) ν / cm ^-1 1768 (C = O expansion / contraction) 1095 (C-O expansion and contraction) 850 (O-O expansion and contraction)

[Reference Example 2] 1,1,2,2-tetrame
Production of tylpropyl peroxy neoheptanoate According to the procedure according to Reference Example 1, except that neoheptanic acid chloride was used instead of pivalic acid chloride, the yield was 2
The compound was obtained with 1.3 g and a yield of 72.5%.

As a result of analyzing the obtained compound, 1,1,
It was found to be 2,2-tetramethylpropylperoxyneoheptanoate, and the benzene solution was 0.1 mol / l.
The 10-hour half-life temperature was 40.6 ° C, and the amount of active oxygen was 6.55%. The analysis results are shown below.

[0072]

[Chemical 7] ¹ H-NMR (acetone-d6) H δ (ppm) a 1.03 (s, 9H) d 1.20 (s, 6H) g 1.24 (s, 6H) h 1.32 to 1.35 ( m, 2H) i 1.50 to 1.57 (m, 2H) j 0.87 (t, 3H, J = 7 Hz) ¹³ C-NMR (acetone-d6) C δ (ppm) a 26.07 b 38 .31 c 86.66 d 20.81 e 174.80 f 43.10 g 25.50 h 43.82 i 18.90 j 14.76 IR (neat) ν / cm ⁻¹ 1765 (C = O expansion and contraction). 1093 (C-O expansion and contraction) 851 (O-O expansion and contraction)

Reference Example 3 1,1,2,2-tetrame
Production of tylpropyl peroxy neodecanoate According to the procedure according to Reference Example 1, except that neodecanoic acid chloride was used instead of pivalic acid chloride, the yield was 2
A compound was obtained with 3.2 g and a yield of 67.5%.

As a result of analyzing the obtained compound, 1,1,
It was found to be 2,2-tetramethylpropyl peroxyneodecanoate. The 10-hour half-life temperature in a benzene solution of 0.1 mol / l was 39.0 ° C., and the amount of active oxygen was 5.59%. The analysis results are shown below.

[0075]

[Chemical 8] ¹ H-NMR (acetone-d6) H δ (ppm) a 1.02 (s, 9H) d 1.17 (s, 6H) g to m 0.68 to 1.55 (m, 19H) ¹³ C- The NMR measurement could not be identified because neodecanoic acid was a mixture of several kinds.

IR (neat) ν / cm ⁻¹ 1770 (C = O expansion / contraction) 1095 (C—O expansion / contraction) 850 (O—O expansion / contraction)

The active oxygen concentration and 10-hour half-life temperature
The measurement of the degree was performed by the following method.Method for measuring active oxygen concentration of polymerization initiator (iodometry
Law) "Organic peroxide, its chemistry and industrial use", Organic peroxide
Method described in Research Group (Chemical Industry Co., Ltd., 1952)
It was carried out according to. The specific method is shown below.

30 ml of benzene was placed in an Erlenmeyer flask with a stopper having an internal volume of about 300 ml, carbon dioxide (flow rate of about 2.5 liter / min) was introduced into the flask for about 30 seconds, and then a sample (1.5 to 1. 8 meq) is measured correctly. Next, 2 ml of saturated sodium iodide aqueous solution was added, and then ferric chloride aqueous solution of acetic acid (0.0002% FeCl ₃
・ 6H ₂ O) (70 ml) was added and the contents were mixed well, and then left in the dark for 15 minutes. Add about 80 ml of pure water,
Titrate with 0.1N sodium thiosulfate solution until colorless. Separately, perform a blank test under the same conditions.

Method for measuring 10-hour half-life temperature of polymerization initiator A solution having a peroxide concentration of 0.1 mol / l was prepared by using benzene as a solvent, and the solution was sealed in a glass tube subjected to nitrogen substitution and kept constant. Immersion in a constant temperature bath set to a predetermined temperature, the polymerization initiator is thermally decomposed, the active oxygen concentration is measured by the above-mentioned method, and the undecomposed polymerization initiator concentration over time is obtained, thereby decomposing at this temperature. Get the rate constant.

Polymerization initiator thermal decomposition formula [I] = [I] ₀ · exp (-K · t)-(a) [I]: Polymerization initiator concentration [I] ₀ : Initial polymerization initiator concentration K: predetermined Decomposition rate constant at temperature t: time K was obtained by the above operation for four types of temperature, and the vertical axis was 1
By taking n (K) and 1 / (RT) on the horizontal axis and performing Arrhenius plot, the activation energy (Ea) of this polymerization initiator is obtained from the slope, and the frequency factor (A) is obtained from the y intercept.

Decomposition rate constant K = A · exp (−Ea / (R · T)) − (b) By transformation, 1n (K) = 1n (A) −Ea / (R · T) A: polymerization Initiator frequency factor Ea: Activation energy of polymerization initiator R: Gas constant T: Temperature at which the concentration of the polymerization initiator becomes 1/2 in 10 hours, that is, 1
The 0 hour half-life temperature is [I] = 1/2 [I] in the equation (A).
_{Since 0} and t = 10 and A and Ea are known,
By substituting (b), T (10-hour half-life temperature) is obtained.

Front page continuation (72) Yoshitaka Okuno, Yoshitaka Okuno, Tohada, Kamisu-cho, Kashima-gun, Ibaraki Shin-Etsu Chemical Co., Ltd., PVC Research Laboratory (56) Reference JP-A-9-87246 (JP, A) JP-A-9-157308 (JP, A) JP-A-8-225521 (JP, A) JP-A-3-296504 (JP, A) JP-A-1-104605 (JP, A) JP-A-7-252307 (JP , A) JP-A-7-278207 (JP, A) JP-A-6-87909 (JP, A) JP-A-5-105709 (JP, A) JP-A-7-138309 (JP, A) JP-B 45-2181 (JP, B1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08F 14/06 C08F 2/00-2/60 C08F 4/34 C08F 14/08 C08F 18/08

Claims (5)

(57) [Claims] 1. When polymerizing a vinyl monomer, the following general formula (1): (Wherein R ¹ , R ² and R ³ represent the same or different straight-chain alkyl groups having 1 to 9 carbon atoms).
A method for producing a vinyl polymer, which comprises adding 1,2,2-tetramethylpropyl peroxy ester compound and polymerizing. 2. The production method according to claim ¹ , wherein in the general formula (1), the total number of carbon atoms of R ¹ , R ² and R ³ is 11 or less. 3. The production method according to claim 2, wherein in the general formula (1), the total number of carbon atoms of R ¹ , R ² and R ³ is 8 or less. 4. The method according to claim 1, wherein the vinyl monomer is a vinyl chloride monomer or a monomer mixture containing the vinyl chloride monomer as a main component, and the resulting polymer is a vinyl chloride polymer. Manufacturing method. 5. As the polymerization initiator, (a) a compound having a 10-hour half-life temperature of 30 ° C. or more and less than 40 ° C. and (b) a compound having a 10-hour half-life temperature of 40 to 70 ° C. are used in combination, and 1,1,2,2-represented by the general formula (1) as the polymerization initiator of at least one of the above (a) and (b)
The production method according to claim 1, wherein a tetramethylpropyl peroxy ester compound is used.