JPH0278658A - Benzyl peroxide composition - Google Patents

Abstract

PURPOSE:To obtain a safe composition consisting of a specific amount of benzoyl peroxide and liquid paraffin having a specified initial boiling point, silicone oil, etc., alone or on combination to provide a specific amount thereof and the remainder of water and useful as a polymerization initiator, etc. CONSTITUTION:A composition obtained by blending benzoyl peroxide (hereinafter abbreviated to BPO) in 65-90wt.% concentration with liquid paraffin having >=200 deg.C/100mmHg initial boiling point or silicone oil, di-2-ethylhexyl adipate or di-2-ethylhexyl sebacate alone or in combination as an additive in an amount of 0.1-5wt.% and the remainder of water. Since a small amount of the additive is effective, shape of wet BPO powder can be retained even by blending thereof with the wet BPO powder without affecting conversion rate into polymers or properties thereof. Thereby, safety in heating under hermetic sealed conditions is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] Benzoyl peroxide (hereinafter abbreviated as BPO) is widely used as a polymerization initiator for vinyl monomers such as styrene, acrylic esters, and vinyl acetate, and as a curing agent for unsaturated polyester resins. This is a typical organic peroxide used.

[Conventional technology]

Pure BPO products are sensitive to impact and have the property of rapidly and violently decomposing when subjected to impact. Therefore, industrially, it is mainly used as a wet powder with water, or as a safe powder or paste with phthalate ester. B.P.
Compositions in which O is wet-pulverized with water are mainly used at a BPO concentration of 75%. Impact safety is greatly improved.

[Problem to be solved by the invention]

On the other hand, a pressure vessel test (abbreviated as PVT) is used to evaluate the danger of decomposing organic peroxides, but the 75% BPO composition wet-powdered with water far exceeds the safety standard of 8 mm or less. 13. Qmm, and although there is no problem with impact safety, there is no improvement in the danger of disassembly, which is represented by PVT.

[Means to solve the problem]

The purpose of the present invention is to provide excellent safety, have no adverse effects on the polymerization process or the physical properties of the obtained polymer when used in the polymerization of vinyl monomers such as polystyrene, and at the same time have good storage and shape stability as well as workability. and BP with excellent safety
An object of the present invention is to provide an O composition.

As a result of intensive studies on BPO formulations that meet these purposes, the present inventors found that liquid paraffin, silicone oil, or di-2-ethylhexylazibe) (DO
The inventors have discovered that the present invention can be obtained by using a wet powder of BPO containing BPO (abbreviated as "A") or di-2-ethylhexyl sebacate (DO3 (abbreviated as -t)) alone or in combination.

The liquid paraffin referred to in the present invention has an initial boiling point (IBP) of 200° C./I OmmHg or more. Also,
Silicone oils include dimethylpolysiloxane and methylphenylbolysiloxane.

Surprisingly, the amount of these additives used in the present invention ranges from 0.1% by weight to 5% by weight, which is effective in small amounts at °C. It is possible to maintain the shape of the body. In addition, it does not similarly affect the conversion rate to polymer or the properties of the obtained polymer.

The concentration of BPO in the present formulation is preferably between 65 and 90% by weight. If it is less than 65% by weight, it is difficult to maintain the blend as a wet powder, and if it is more than 90% by weight, the safety exceeds the standard value. Water should be mixed in a balanced amount. There are two methods for producing this formulation: After synthesizing a wet powder of BPO at a certain concentration, the necessary amount of additives are mixed to form a composition;
It is possible to add additives during the synthesis of the wet powder.

Specific examples are shown below.

Example I In a 51 beaker equipped with a stirrer, thermometer and addition funnel, 1600 g of water and 400 g of 25% sodium hydroxide (2,
5 mol) and 5 g of a 10% Neogen R (manufactured by Dai-Kogyo Seiyaku) aqueous solution were added, and the mixture was cooled to 10° C. under external cooling. 6 in this solution
68g (1.2 mol) of 0% hydrogen peroxide solution at 10-15℃
It was added dropwise while stirring while maintaining the temperature.

Subsequently, benzoyl chloride 2 was added to the resulting mixture.
80 g (2.0 mol) was charged at 10-15°C with vigorous stirring, and the reaction mixture was heated at 10-15°C.
The mixture was stirred for 60 minutes. After the reaction was completed, the reaction mixture was dehydrated using a centrifugal separator, and further washed with water until the filtrate no longer showed alkalinity.
The sample with a yield of 95%) was used as a sample of the formulation containing 75% or less of BPO in Example 2.

Separately, 79% wet powder BPO with 95% BPO content,
The same Example! Air dried to 5% water and mixed in the same manner as the previous formulation. The sample was a formulation containing 80% or more of BPO.

The composition, safety data, and shape of these formulations are summarized in Table-1.

Safety data was measured by the following method.

・Pressure vessel test (PVT) 5g of sample is placed in a pressure vessel equipped with an orifice with an arbitrary hole diameter and a rupture plate made of aluminum foil of a certain strength.
Let the aluminum sample container containing the sample stand still and heat the bottom with a chicle burner to decompose the sample. By adjusting the diameter of the orifice, the diameter of the hole where the aluminum foil rupture plate ruptures even after 5 repetitions of the test is determined.

The sample is rapidly thermally decomposed in the test container in a sealed state, so the larger the orifice diameter, the more intense and rapid decomposition will occur, which can be dangerous. It shows.

・Drop-drop sensitivity test (DHT) Test using an explosive drop-drop tester. Place the sample on top of the wood, place a steel column on it, and raise it 55 degrees from the height above it.
Drop a kg weight and observe whether the sample ignites or explodes. Normally, the test is carried out 10 times to find the highest height without exploding even once.

(This is called the maximum non-explosion height.) This method expresses the sensitivity of the peroxide to the impact force caused by a weight, and at the same time it also means to some extent its sensitivity to frictional effects.

In addition, in this method, it is preferable for safety that ignition does not occur at a falling height of 5 Q cm or less, that is, that the impact sensitivity is 5 kgX O, 5 m = 2.5 kg-m or more.

Example ■ In a 52 beaker equipped with a stirrer, thermometer and dropping funnel, 1600 g of water and 400 g of 25% sodium hydroxide (2,
5 mol) and 5 g of a 10% Neogen R (manufactured by Dai-Kogyo Seiyaku) aqueous solution were added, and the required amounts of liquid paraffin, silicone oil, DOA, and DO8 were added, and the mixture was cooled to 10° C. under external cooling. To this solution, 68 g (1.2 mol) of 60% hydrogen peroxide solution was added dropwise while stirring while maintaining the temperature at 10 to 15°C. In the resulting mixture, benzoyl chloride 280
g (2.0 mol) was reacted at 10-15°C with vigorous stirring, and the reaction mixture was further heated at 10-15°C for 60 mols.
Stir for a minute. After the reaction was completed, the reaction mixture was dehydrated using a centrifugal separator, and further washed with water until the filtrate no longer showed alkalinity, to obtain a wet powder of 75% or more as BF2 minutes. A sample was prepared by adding and mixing the necessary amount of water to the wet powder using a mixer so that the BF2 content was 75%.

The composition, safety data, and shape of these formulations are summarized in Table 2.

Comparative Example 1 Isoparaffinic solvent, dioctyl phthalate, glycerin, decyl alcohol, low n
Point K BP using dynamic halafine, xylene, diethylene glycol, diethyl ether, butyl stearate
An O wet powder formulation was prepared and safety data was measured.

The results and shapes are summarized in Table 3.

Example ■ A brown ampoule with a content of 3 ml contains styrene monomer, benzoyl peroxide as a polymerization initiator, and t-
1.5 g of a monomer solution containing a predetermined amount of butyl peroxybenzoate was charged, and after purging with nitrogen gas, the container was sealed. Polymerization was carried out for a predetermined time in a water bath set at a predetermined temperature.

The polymerization conversion rate of the obtained polymer was determined by calculating the amount of residual monomer by gas chromatography. Moreover, the average molecular weight value was measured by GPC method by creating a calibration curve using standard polystyrene. The results are summarized in Table-4.

Comparative Example ■ Commercially available 75% BPO instead of the BPO composition of Example 1
Polymerization was carried out according to Example 2, except that the wet powder (Reference 1) and the BPO composition of Comparative Example 1 were used, and the properties of the obtained polymer were evaluated. The results are summarized in Table-4.

〔Effect of the invention〕

As shown in Examples, the benzoyl peroxide wet powder composition of the present invention has significantly improved safety when heated under closed conditions compared to conventional compositions containing only BPO and water. It has great industrial value because it does not adversely affect the polymerization characteristics and physical properties of the polymer even when used in actual polymerization.

Patent applicant: Kayaku Nouri Co., Ltd.

Claims (1)

[Claims] 65 to 90% by weight of benzoyl peroxide and additives such as liquid paraffin with an initial boiling point (IBP) of 200°C/10mmHg or higher, silicone oil, or di-
2-ethylhexyl adipate or di-2-ethylhexyl sebacate alone or in combination 0.1 to 5
A benzoyl peroxide composition comprising % by weight and the balance water.