JPH02279703A - Triphenylmethyl peroxypivalate and its use - Google Patents

Abstract

PURPOSE:To increase the production capacity by shortening the polymerization cycle by increasing the polymerization rate, to perform the low-temperature polymerization of vinyl chloride and to obtain a polyvinyl chloride of excellent properties and a high degree of polymerization by using triphenylmethyl peroxypivalate as a polymerization initiator. CONSTITUTION:Triphenylmethyl peroxypivalate is used as a polymerization initiator especially for the production of a vinyl chloride resin. When this initiator is used in the polymerization of a vinyl chloride monomer optionally together with another monomer copolymerizable therewith, triphenylmethyl peroxypivalate (A) and optionally at least one polymerization initiator (B) comprising at least one member selected from among a peroxyester, a diacylperoxyester and a peroxydicarbonate each of which has a 10hr-half life temperature in the range of 35 to 65 deg.C in a 0.1mol/l concentration in benzene (in an A/B ratio of 1:0.25 to 1:4) are added to the reaction system.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to triphenylmethylperoxypivalate, which is a novel peracid ester that is excellent as a radical polymerization initiator.

BACKGROUND OF THE INVENTION From an economic standpoint, it is desirable in the polymer industry to increase polymer productivity without resorting to the construction of additional expensive production equipment. For this reason, polymerization initiators with higher activity have been desired. In other words, by using a highly active polymerization initiator, it is possible to increase the polymerization rate and shorten the polymerization cycle time.

Productivity potters using such techniques are particularly useful in the polymerization of vinyl chloride. This is because, in the polymerization of vinyl chloride, the molecular weight of the polymer is determined by the polymerization temperature and is not dependent on the polymerization rate. Therefore, even if the polymerization rate is increased using a highly active polymerization initiator, the molecular weight will not change.

In addition to the purpose of improving productivity as described above, a more active radical polymerization initiator is desired.

That is, it concerns the production of highly polymerized polyvinyl chloride.

Polyvinyl chloride with a degree of polymerization of 1500 or more is
It is generally called a highly polymerized product and is known to have particularly excellent physical properties such as mechanical strength, thermal stability, dimensional stability, and cold resistance.

Furthermore, in soft vinyl chloride manufactured by adding a plasticizer to polyvinyl chloride, the rubber elasticity can be improved as the degree of polymerization increases.

As shown in Table 1, the degree of polymerization of polyvinyl chloride is determined by its polymerization temperature, so in order to obtain polyvinyl chloride with such a high degree of polymerization, vinyl chloride must be heated at a relatively low temperature of 50°C or less. must be polymerized.

For this reason, a polymerization initiator that is sufficiently active even at low temperatures is desired.

Table 1 Various perpivalate esters have been known as polymerization initiators that are active even at such relatively low temperatures. That is, t-butylperoxypivalate, t-octylperoxyvivalate, cumylperoxyvivalate, and the like.

(Problems to be Solved by the Invention) The temperature at which the decomposition half-life of these conventionally known perpivalic acid esters at a concentration of 0.1 mon/1 in benzene is 10 hours (hereinafter referred to as 10-hour half-life temperature). ) were all 45 to 55°C, and although their activity was higher than that of other conventional peracid esters, it was not sufficient, and the effect of shortening the polymerization time was small. Therefore,
For purposes of shortening polymerization times and increasing production capacity, and for polymerization at low temperatures, there continues to be a need for more low temperature active polymerization initiators.

(Means for Solving the Problems) As a result of long-term research on the problems of the above-mentioned prior art, the present inventors discovered that triphenylmethylperoxypivalate, a new compound unknown in the literature, The present invention was completed by confirming that this initiator has a shorter decomposition half-life than pivalic acid ester and is more active in the polymerization of vinyl chloride.

That is, the present invention relates to triphenylmethyl peroxypivalate, and the present invention further relates to polymerization initiation when vinyl chloride monomer or vinyl chloride monomer and a monomer copolymerizable therewith are respectively polymerized. using triphenylmethylperoxypivalate alone as an agent;
Alternatively, a polymerization initiator comprising at least one of peroxyethesur, diacyl peroxide, and peroxydicarbonate whose half-life in benzene at a temperature of 10 hours is in the range of 35 to 65°C. This is a method for polymerizing vinyl chloride, which is characterized in that it is used in combination.

The peracid ester of the present invention can be obtained according to a conventional method, for example, as follows.

That is, pivalic acid chloride and triphenylmethyl hydroperoxide are prepared using sodium hydroxide, potassium hydroxide, or an amine such as pyridine as a catalyst under the same reaction conditions as for ordinary peroxy esters.

That is, as a solvent, aromatic hydrocarbons (e.g. toluene, ethylbenzene) or aliphatic hydrocarbons (e.g. pentane, hexane, octane, petroleum naphtha, mineral spirits) or isoparaffin-based aliphatic hydrocarbons (e.g. ”; manufactured by Shell Chemical Co.)
It can be synthesized using the following methods, or it can be diluted and used after synthesis. Note that the reaction temperature is about -10°C to 30°C.

Pivalic acid chloride used in the present invention refers to pivalic acid containing a chlorinating agent such as pczi, POCj2:+, soc
The acid chloride product can be prepared by isolating the acid chloride product from the reaction mixture after reacting p□, etc.

The triphenylmethyl hydroperoxide used in the present invention can be used in the presence of a strong acid catalyst such as sulfuric acid, phosphoric acid, perchloric acid, an acid form of an ion exchange resin, or p-)luenesulfonic acid to remove an excess of triphenylcarbinol. It can be made by processing with hydrogen oxide.

Examples of other vinyl monomers copolymerizable with the vinyl chloride monomer used in the present invention include ethylene, vinyl acetate, vinylidene chloride, styrene, and acrylic esters.

The polymerization initiator used in the present invention is triphenylmethylperoxypivalate, and the amount added is generally 0.001 to 1 part by weight in pure terms per 100 parts by weight of vinyl chloride monomer. Part by weight, preferably 0.01
~0.5 parts by weight. If the amount is less than 0.001 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 also deteriorate (this is not preferable since it is on the opposite side of the river).

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 35 to 65°C.

A specific peroxyester is BND (46,5
“C), tertiary-butylperoxyneohexanony)
(52,1℃), tertiary-butylperoxypivalate (55℃), tertiary-octylberoxyneodecanoate (41℃), cumylperoxyneodecanoate (
36.6℃), NP as a diacyl peroxide
O (59,5 °C), lauroyl peroxide (62 °C
), octanoyl peroxide (62"C), etc., and peroxydicarbonates include OPP (43°5"C), di(2-ethoxyethyl) peroxydicarbonate (43,4'C), di-n propyl Peroxydicarbonate (40.5°C), diisoprobyl 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 triphenylmethylperoxypivalate added.

The polymerization method used in the present invention is usually suspension polymerization, but there is no problem with normal formulations except for the use of the polymerization initiator of the present invention.

The polymerization temperature is generally 10-75°C, preferably 3°C.
The temperature range is 0 to 60°C. If the polymerization temperature is less than 10°C, the polymerization time tends to be long, whereas if it exceeds 75°C, the life of the polymerization initiator will be shortened and it will be difficult to reach a high polymerization conversion rate, which is not preferable.

(Effect of the invention) The triphenylmethyl peroxypivalate of the present invention is
It is a new compound and is characterized by a shorter half-life for decomposition than peroxides known in the prior art. Therefore, the polymerization rate can be increased by using the peracid ester of the present invention alone as a polymerization initiator in conventional polymerization, or by using it in combination with a specific polymerization initiator. Therefore, polymerization cycle time can be shortened and production capacity can be increased.

Furthermore, by using the peracid ester of the present invention, -
Since vinyl chloride can be polymerized at a low temperature, highly polymerized polyvinyl chloride with excellent -1 physical properties can be obtained.

(Examples) Hereinafter, the present invention will be specifically explained using reference examples and examples.

Reference example (synthesis of triphenylmethyl hydroperoxide) In a 500 ml 24-hole flask equipped with a stirrer, 5
A mixture of 63.9 g of 0% hydrogen peroxide solution and 58.8 g of 83.8% sulfuric acid aqueous solution was added at an internal temperature of 10°C.
While stirring, 63.4 g of triphenyl carbinol and 300 g of toluene were added dropwise over 10 minutes. After the addition, the reaction mixture was stirred for an additional 6 hours at a temperature of 25°C. The solution was separated, the oil phase was washed three times with water, and after drying over anhydrous magnesium sulfate, the toluene was removed under vacuum,
A pale yellow solid crude product was obtained. This was then washed with n-pentane and dried to obtain 126.5 g of white crystals as a product. When the melting point was measured, it was 89-92°C. Further, the amount of active oxygen was 5.49%, and the purity was calculated to be 94.9% and the yield was 86.9 mol%.

The identity of this substance was confirmed by IR and NMR spectra.

IR spectrum (CCf4): Benzene ring stretching vibration 1600.1495.1455c
m-'00-H stretching vibration 3500cm-'NMR
Spectrum ((CD3) gco) :H: δ 1
0.46. s, IH.

Example 1 (Synthesis of triphenylmethylperoxypivalate) 200+m424 flasks equipped with a stirrer.
% potassium sea urchin hydroxide aqueous solution was added thereto, and while stirring and maintaining the liquid temperature at 15° C., a mixture of 29.1 g of 94.9% triphenylmethyl hydroperoxide synthesized in Reference Example and 50 g of benzene was added. While stirring, the temperature of the liquid was increased to 1.
While keeping at 5℃, add 14.5 g of pivalic acid chloride to 1
It was dropped in 0 minutes. After raising the liquid temperature to 20° C. and continuing stirring for 1.5 hours, 70 g of cold water was added and stirring was further continued for 5 minutes.

The aqueous phase was separated, washed with 100 g of a 5% aqueous sodium hydroxide solution, and then washed three times with water. After drying this solution over anhydrous magnesium sulfate, benzene was removed under vacuum to obtain a crude product as pale yellow crystals. These crystals were recrystallized from ether to obtain 22.6 g of a product as white crystals. When the melting point was measured, it melted and decomposed at 76°C.

Further, the amount of active oxygen was 4.16%, the purity was calculated to be 93.8%, and the yield was 58.7 mol%.

The identity of this substance was confirmed by IRh and NMR spectra.

IR spectrum (CCIt 4): Benzene ring stretching vibration 1595.1490.1450 Rho 1C=O stretching vibration 1770C! 11-' half-life temperature (T,.) was determined. The above results are shown in Table-2.

This result shows that the triphenylmethyl peroxypivalate of the present invention has a shorter degradation half-life than the prior art perpivalate ester.

Table-2 HO:　δ　7.32. 1m, 158.

Example 2 A thermal decomposition test was conducted using benzene as a solvent (concentration: 0
．． 1 mol/1), the 10-hour half-life temperature of the peracid ester of the present invention synthesized in Example 1 was determined. For comparison, a known peracid ester of pivalic acid derivative was similarly used for 10 hours (vinyl chloride polymerization).
1 part by weight was added and dissolved. Next, 0.07 parts by weight of triphenylmethylperoxypivalate (hereinafter abbreviated as TPPV) was added in terms of pure product, and then cooled to -80°C or lower, and 100 parts by weight of vinyl chloride monomer was 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 40° C. for 8 hours to polymerize. For stirring, place the autoclave in a water tank for 32 hours.
r, p, +1. This was done by rotating it. After polymerization, it is cooled and unreacted vinyl chloride monomer is removed.
The resulting white powder was washed twice with 100 ml of water and then dried in vacuo. The yield of vinyl chloride polymer was 85% based on weight, and the average degree of polymerization was 2,530. 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.

The results are shown in Table 3.

[Colorability test and odor] 100 parts by weight of vinyl chloride polymer, dioctyl phthalate)
50 parts by weight and 2.5 parts by weight of dibutyltin malate were mixed and kneaded for 10 minutes on a roll at 160"C to form a 1 mm
The FJ sample sheet was taken out and the degree of coloring of the sheet was visually observed. At the same time, the odor of the sheet was examined when it was taken out.

Examples 4 and 5 Vinyl chloride monomers were polymerized in the same manner as in Example 3, except that the amount of TPPV used as a polymerization initiator and the polymerization temperature were changed. These results are shown in Table 3.

Example 6 As shown in Table 3, TPPVo,
Polymerization of vinyl chloride monomer was carried out in accordance with Example 3, except that CNDO, 3 parts by weight was used in addition to CNDO, 3 parts by weight.

Example 7.8 As shown in Table 3, Niopp and NPO were used as polymerization initiators instead of CND, respectively, in TPPV O,03
Polymerization of vinyl chloride monomer was carried out in accordance with Example 3, except that the polymerization temperature was 45°C.

Example 9 Same as Example 3 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-3. Polymerization was performed.

Comparative Example 1 As shown in Table 3, Example 3 except that t-butylberoxypivalet (BPV) was used as a perpivalic acid ester conventionally known as a polymerization initiator.
Polymerization of vinyl chloride monomer was carried out according to .

Comparative Example 2 As shown in Table 3, vinyl chloride monomer was polymerized according to Example 3, except that cumyl peroxyvivalate (hereinafter abbreviated as CPv) was used as a polymerization initiator. .

Comparative Example 3 As shown in Table 3, vinyl chloride monomers were polymerized in the same manner as in Example 3, except that CND was used in addition to CPv as a polymerization initiator.

As is clear from Table 3, the method using the polymerization initiator of the present invention provides a polymer with good physical properties in higher yield than the conventional method using perpivalic acid ester as a polymerization initiator.

Special permission Out wish Man Nihon Yushi Co., Ltd.

Claims (1)

[Scope of Claims] 1. Triphenylmethylperoxypivalate 2. A radical polymerization initiator containing triphenylmethylperoxypivalate as an active ingredient. 3. Vinyl chloride monomer or vinyl chloride monomer and a monomer copolymerizable therewith are each polymerized using triphenylmethyl peroxypivalate as a polymerization initiator. Polymerization method. 4. When polymerizing vinyl chloride monomer or vinyl chloride monomer and a monomer copolymerizable therewith, (A) triphenylmethylperoxypivalate and (B) 0.1 in benzene. Chlorination characterized by using in combination a polymerization initiator consisting of at least one of peroxyesters, diacyl peroxides, and peroxydicarbonates whose temperature at which the half-life in a molar concentration solution is 10 hours is in the range of 35 to 65°C. Vinyl polymerization method.