JP3165454B2 - Method for producing organic peroxide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing di (2,2-dimethylpropyl) peroxydicarbonate, which is a radical polymerization initiator, and more particularly, to a method for producing a homogeneous powder having a chlorine content. The present invention relates to a method for producing a small amount of di (2,2-dimethylpropyl) peroxydicarbonate.

[0002]

2. Description of the Related Art Generally, when synthesizing a dicarbonate-based organic peroxide as a radical polymerization initiator, when the product is a liquid, the chlorine content due to the raw material chloroformate is low and there is almost no problem in quality. When the product is a powder, chloroformate as a raw material is incorporated into the product during the reaction, and the chlorine content increases, which often causes quality problems.

[0003]

When di (2,2-dimethylpropyl) peroxydicarbonate reacts with 2,2-dimethylpropyl chloroformate and an aqueous solution of alkali peroxide, it precipitates as crystals in the course of the reaction. Come. The crystal product contains 2,2-dimethylpropylchloroformate, which is a reaction raw material during crystal precipitation, and the resulting product crystal is a non-uniform powder crystal partially including a large particle diameter, and contains chlorine. There is a disadvantage that the amount is large. Furthermore, the polymer obtained by using such a polymerization initiator having a high chlorine content has a problem. For example, an alkylene glyco useful as a plastic lens monomer
When a polymer containing rubis (allyl carbonate) as a main component or a copolymer with a vinyl monomer is used, di (2,2-dimethylpropyl) peroxydicarbonate having a large chlorine content is used. There are problems such as a pale yellow coloration.

[0004] The reason why the chlorine content is increased as described above is that unreacted chloroformate is taken into the crystal during the reaction, and the unreacted chloroformate contained in the crystal becomes excessive because the crystal becomes a protective film. This is probably because they do not react with the aqueous alkali oxide solution. Therefore, after the reaction, even if the product is separated by filtration and washed repeatedly with water and alkali, the obtained product crystals contain many particles having a large particle size and only those having a high chlorine content can be obtained. In order to obtain a product having a low chlorine content from such a product, recrystallization treatment using a solvent or pulverization in a mortar or the like and alkali washing may be performed.

[0005] However, these operations increase man-hours and are not industrially advantageous solutions. Further, high-speed stirring and the like have been devised in order to reduce the particle size of the crystals precipitated in the reaction step. However, when the reaction scale becomes large, not only special equipment such as a homogenizer is required but also a hydrogen peroxide solution,
There is a problem that the alkali peroxide solution is decomposed and the product yield does not increase.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve these problems, and as a result, the presence of a surfactant in the reaction system without using any special reaction equipment makes it possible to increase the size of the reaction system. The present inventors have found that a uniform product crystal containing no particles and containing no unreacted chloroformate and having a low chlorine content can be obtained, thereby completing the present invention. .

The surfactant used in the present invention is usually an anionic or nonionic surfactant. For example, in the case of anionic compounds, alkyl sulfates such as sodium dodecylbenzene sulfate, sodium lauryl sulfate, potassium lauryl sulfate and sodium stearyl sulfate; polyoxyethylene alkyl ether sulfates such as sodium polyoxyethylene lauryl ether sulfate; Alkyl sulfocarboxylates such as sodium ethylhexyl sulfosuccinate and sodium lauryl sulfoacetate; alkyl phosphates such as sodium lauryl phosphate and sodium oleyl phosphate; sodium polyoxyethylene lauryl ether phosphate; sodium polyoxyethylene oleyl phosphate; And polyoxyethylene alkyl ether phosphates and polyoxyethylene alkyl acetates. In the case of a nonionic system, HLB 11 or more, preferably HLB 14 or more, is used. For example, polyoxyethylene (20) sorbitan monolaurate, polyoxyethylene (20) sorbitan monopalmitate,
Polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene (20) sorbitan monostearate; polyoxyethylene (21) lauryl ether; polyoxyethylene (30) cetyl ether; polyoxyethylene (15) oleyl ether; Oxyethylene alkyl ethers, polyoxyethylene (10)
Nonyl phenyl ether, polyoxyethylene (30)
Polyoxyethylene alkyl phenyl ethers such as octyl phenyl ether, polyoxyethylene (60)
And polyoxyethylene castor oils such as castor oil, and polyoxyethylene hardened castor oils. Further, it is preferable that the surfactant can be removed when the product crystals are washed with water after filtering the product crystals. The amount of the surfactant to be added is usually 0.005 to 1% by weight, preferably 0.01 to 1% by weight in the reaction system.
~ 0.5% by weight. If the amount of the surfactant added is too large, the number of times of washing the product crystals with water increases, and if the amount is too small, dispersion becomes insufficient at the time of crystal precipitation. The surfactant is added to at least one of 2,2-dimethylpropylchloroformate and an aqueous alkali peroxide solution.

[0008] The production method of the present invention in which a surfactant is added includes 1) a method in which chloroformate is dropped into an aqueous solution of alkali peroxide, 2) a method in which an aqueous solution of alkali peroxide is dropped into chloroformate, and 3) a method in which chloroformate is added. Any method of mixing hydrogen peroxide into a mate and then dropping an aqueous alkali solution can be adopted, and the reaction temperature is usually -5 ° C to
Performed at + 20 ° C.

Examples of the alkali peroxide used in the present invention include sodium peroxide, potassium peroxide, and the like. The aqueous alkali peroxide solution is used in the reaction system by simultaneously adding aqueous hydrogen peroxide and an aqueous alkali solution during the production of peroxide. The case where it is generated is also included.

[0010]

The alkylene glycol bis (allyl carbonate) useful as a plastic lens monomer using di (2,2-dimethylpropyl) peroxydicarbonate having a low chlorine content obtained by the present invention. And a copolymer with a vinyl monomer was colorless and transparent, and no pale yellow coloring was observed.

[0011]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the embodiments.

[0012]

Example 1 A 500 m far four-necked flask equipped with a stirrer and a thermometer was charged with 80 g of 2,2-dimethylpropylchloroformate and cooled to 0 ° C. 76 g of a 30% aqueous sodium hydroxide solution, 176 g of ion-exchanged water, 28 g of a 35% hydrogen peroxide solution, 0.07 sodium dodecylbenzenesulfonate
2 g (anionic surfactant, concentration 0.02 in the reaction system)
%) Is added dropwise while maintaining the inside of the flask at 0 to 10 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 1 hour to complete the reaction. Then, the reaction slurry is separated by filtration, and the cake is washed with water. After washing with water, the powder was dried at 30 ° C. or lower to obtain 64.8 g of powdery crystals having uniform particles. This powder crystal had an active oxygen content of 6.09% by iodometry, a product purity of 99.8% and a chlorine content of 0.01% or less by coulometric titration analysis with a silver electrode.

[0013]

Example 2 Sodium dodecylbenzenesulfonate 0.0
The reaction was carried out in the same manner as in Example 1 except that 72 g was changed to 1.44 g of polyoxyethylene (20) sorbitan monolaurate (HLB16.9) (nonionic surfactant, concentration in the reaction system: 0.40%). The resultant was washed with water and dried to obtain 64.1 g of uniform crystals. As a result of the analysis,
Active oxygen content: 6.09%, purity: 99.8%, chlorine content: 0.01% or less.

[0014]

Reference Example 1 5 g of di (2,2-dimethylpropyl) peroxydicarbonate obtained in Example 1 was dissolved in 95 g of diethylene glycol bis (allyl carbonate). The solution was poured into two glass plates sandwiching a 5 mm thick spacer, and the temperature was raised from 40 ° C. to 90 ° C. over 22 hours, and then kept at 120 ° C. for 2 hours. The Barcoal (type 934-1) hardness of the obtained polymerized test piece was 50, and it was colorless and transparent, and no coloring was observed.

[0015]

Reference Example 2 Except that 5 g of (2,2-dimethylpropyl) peroxydicarbonate obtained in Example 1 was changed to 5 g of (2,2-dimethylpropyl) peroxydicarbonate obtained in Example 2. Performed the same processing as in Reference Example 1. The Barco hardness of the obtained polymerized test piece was 49, and it was colorless and transparent, and no coloring was observed.

[0016]

Comparative Example 1 80 g of 2,2-dimethylpropylchloroformate was charged into a 500-m four-neck flask equipped with a stirrer and a thermometer, and cooled to 0 ° C. A mixture of 76 g of a 30% aqueous solution of caustic soda, 172 g of ion-exchanged water and 28 g of 35% aqueous hydrogen peroxide is added dropwise while maintaining the inside of the flask at 0 to 10 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 1 hour to complete the reaction. Then, the reaction slurry is separated by filtration, and the cake is washed with water. After washing with water, dry at 30 ° C. or less, powdery crystal 64.2
g was obtained. As a result of analysis, this powder crystal was found to have an active oxygen content of:
6.03%, purity: 98.9%, chlorine content: 0.3
8%. Diethylene glycol bis (allyl carbonate) was polymerized in the same manner as in Reference Example 1 except that (2,2-dimethylpropyl) peroxydicarbonate obtained by this method was used. The obtained polymerization test piece had a Bacoal hardness of 48 and a pale yellow coloration was observed.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C07C 409/00 C07C 407/00 C08F 4/00 C08F 18/00 CA (STN)

Claims (1)

(57) [Claims] 1. A process for preparing a crystalline powder di (2,2-dimethyl-propyl Le) Pas over dicarbonate by reacting a 2,2-dimethylpropyl chloroformate and alkaline peroxide solution, 2, A method for producing powdery crystalline di (2,2-dimethylpropyl) peroxydicarbonate, comprising adding a surfactant to at least one of 2-dimethylpropyl chloroformate and an aqueous alkali peroxide solution.