JPS5927868A - Succinic acid peroxide composition - Google Patents

Abstract

PURPOSE:To provide the titled composition capable of keeping high safety, stability and fluidity in low-temperature storage, having excellent handleability, and useful especially as a catalyst for the emulsion polymerization of tetrafluoroethylene, etc., by compounding a specific amount of water with succinic acid peroxide. CONSTITUTION:The succinic acid peroxide can be prepared by conventional process, i.e. by the reaction of succinic anhydride with hydrogen peroxide in the presence of an alkali. The obtained crude succinic acid peroxide containing a large amount of water is dried by a conventional method to obtain the titled composition containing 10-25wt% of water. When the water-content is <10wt%, the composition is sensitive to impact, and cannot be handled safely, and when the water content exceeds 25wt%, the fluidity of the composition becomes poor. The water-content of 12-20wt% is especially preferable in view of balanced fluidity and safety. EFFECT:There is not the least adverse effect in the polymerization reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention consists of water of a specified strength and succinic acid peroxide, which can be safely stored at low temperatures, is easy to handle, and is particularly suitable for use in tetrafluoroethylene ( Later TFE
This invention relates to a succinic acid peroxide composition useful as a catalyst for emulsion polymerization such as

Succinic acid peroxide is a white solid organic peroxide that has free carboxylic acid in its molecule and is highly water-soluble. In its pure state, this peroxide is extremely sensitive to impact and flammable, so it has been difficult to handle it industrially.

Generally, in order to safely handle dangerous organic permides, there are three methods: (a) diluting them with a solvent, (b) making a paste with a plasticizer, and (c) moistening them with water. Methods such as these are being implemented.

However, since the main use of amber peroxide is as a polymerization catalyst for TFE as mentioned above, the products treated by methods (a) and (b) may inhibit polymerization or inhibit the dispersion system. , it is not possible to efficiently produce the desired polymer. In addition, in method (c), as described in the American Chemical Journal Vol. To avoid this, it must be stored at temperatures below 15C, preferably below 110C. This is a feature that is not observed at all in organic peroxides other than conohecic acid peroxide.

However, when succinic acid peroxide is stored at such low temperatures, it gradually loses its fluidity as the coexisting moisture increases.
It is difficult to handle it as a powder, and it is also difficult to measure it, creating a big problem in its handling.

Therefore, even if uccinic acid peroxide is treated by the method (3) above, it has been thought that it is extremely difficult to handle it practically.

However, the present inventors have found various results regarding the relationship between Kono-ret label oxide and coexisting moisture in the case of low-temperature storage (0 [as a result of research, it is possible to maintain the properties of safety, stability, and fluidity). The present invention was completed by confirming that there is a critical range.

More specifically, the present invention relates to an easy-to-handle phosphoric peroxide composition that can be safely stored at low temperatures and contains 10 to 25 percent by weight water and succinic peroxide. Although the composition contains only water and succinic acid peroxide, it may contain small amounts of impurities that do not interfere with the use of the composition, such as polymerization. Therefore, Kono・
The weight ratio in the composition of 4' acid peroxide is 70.
~90.

If the moisture content does not reach 10% by weight,
The composition is sensitive to impact and therefore cannot be handled safely. IN5j at 10 weight percent
rr against M! ! ! degree decreases rapidly.

As the moisture content increases, the composition of No. 1 tends to solidify when stored at low temperatures below -5C, but below 25% by weight, fluidity is substantially maintained and there is no problem in practical use. However, if 25% of the overprint is applied, the proportion of solidified portions increases, the fluidity decreases, and the powder properties are lost, making it difficult to handle εf magnets and the like. Furthermore, when the water content is 12 to 20 percent by weight, the fluidity and safety are particularly excellent overall.

The composition of the present invention does not contain any solvent or plasticizer.

Therefore, even when used for polymerization, it suppresses polymerization.
In addition, it does not have any negative impact on the slag reaction, such as inhibiting the dispersion system.

The succinic acid peroxide in the present invention is, for example,
As described in Japanese Patent No. 4-1'5685, it is easily produced by a known method, that is, by reacting succinic anhydride with hydrogen peroxide in the presence of an alkali. The composition of the present invention can be easily obtained by drying the crude succinic acid peroxide containing a large amount of water produced during the production of the succinic acid peroxide by known means to a desired water content. It can also be produced by adding the necessary amount of water to dry succinic acid peroxide that does not contain water and mixing uniformly to adjust the desired water content.
As an eagle, you need to be careful when doing this for safety reasons.

Next, an example of a method for producing the composition of the present invention will be shown based on experimental examples.

Example Sodium acetate 6,0 y-((1,
6oo y of an aqueous solution containing 0.07 mol) and 50% hydrogen peroxide solution 6'1l-21i' (0.90 mol), then 150.01i' (1,
50 mol) was added with stirring, and the reaction was continued at 15C for 60 minutes.

After the obtained reaction product was filtered, it was washed twice with Oc water,
A white succinic acid peroxide hydrate 2537 was obtained.

The active oxygen content of this product according to iodometry is 3.
97% (purity 58.1%), the composition in the water content is succinic acid peroxide 58.1 x amount percentage, water 40.4 weight percentage, and the yield of succinic acid peroxide based on succinic anhydride is 77%. 'Met.

Next, the above-mentioned succinic acid peroxide hydrate was heated to a rotation radius of 0.
One sample 200 y using a 15Tn centrifuge
The spindle was dehydrated for 30 minutes at different rotational speeds. The drawing shows the relationship between the water content of the succinic acid peroxide obtained after dehydration and the rotation speed of the centrifuge.

In the figure, the horizontal axis represents the rotation speed of the centrifuge, and the vertical axis represents the water content in the composition.

When controlling the water content of the composition of the present invention using a centrifugal separator, it can be seen that the amount of water can be adjusted by adjusting the rotational speed. Note that the moisture content can be easily adjusted by other known methods.

Next, the composition of the present invention will be explained based on Examples and Comparative Examples.

EXAMPLES Compositions of the present invention having different water content were prepared by the method shown in the experimental examples, and the compositions of the present invention having different water latencies were prepared and
) and No. 7, page 171 (1968), the hazards were evaluated, and each of the similar compositions was stored in a freezer at -10C for one month, and then removed. l) at to calculate the respective weight percentages of the powder part and solidified block part of each sample, and determine the fluid/solid properties. The results are listed in the table below.

Comparative Examples 1 to 3 Compositions with water content outside the range of the compositions of the present invention were prepared in the same manner as in the examples, and the risks were evaluated in the same manner as in the examples. The weight ratio of the powder part and the block part after frozen storage was calculated in the same manner as above. The results are listed in the table below.

The measurement method for the safety measurement test is shown below.

Drop hammer sensitivity test method: Place sample 0.11 into a 10+imφ tin foil cup.
Place a piece of tin foil on top of the ``Kanashiki'', place a steel column of 12.7++t+++φX12.7mm on top of the sample, and drop a 5 kg hammer onto the steel column from a predetermined height. shock the sample. Then, it was determined whether the sample decomposed or not, and 10 samples at the same drop height were tested.
The highest drop 1q that was not allowed to be disassembled was dropped! 3 degrees. The higher the number, the safer it is.

Pressure Vessel Test A certain sample is placed in a stainless steel pressure vessel equipped with a rupture disc and an orifice hole that can change the pore diameter, and heated from the outside. Record the time from the start of heating until the rupture disc ruptures or sudden gas erupts. If it does not burst, reduce the orifice diameter and perform the test. Perform two tests using orifices with the same diameter to determine the minimum diameter of the orifice that will not cause the rupture disc to rupture. Therefore, the smaller the number, the safer it is.

Ballistic mortar test This is a test method for explosives, and the test rA device is JIS-4.
810. The lower the number, the higher the safety.

The table shows Examples and Comparative Examples, and the composition of the present invention is highly safe and substantially maintains the properties of a powder.

On the other hand, the composition shown in the comparative example maintains the properties as a powder when the water content is low, but there are safety problems.
B. When the moisture content is high, the safety is excellent, but the properties as a powder are lost.10 Next, according to the reference example, the composition of the present invention is used as a catalyst for polymerization of TFE. Show that you are excellent.

Reference Example: In a stainless steel autoclave equipped with a stirring device, 1000P of deionized water and solid paraffin (melting point 52
T? ~54C)601i', fluorine-based dispersant (C
. Press in with d. 85tll'
After raising the temperature to 28 ky/crA, TFE was further injected under pressure to start polymerization.

The reaction was continued while maintaining a pressure of 27 ky/crd to 28 kg/cyf, and after 6 hours, an aqueous polytetrafluoroethylene dispersion containing 33.6% by weight of polymer was obtained.

The produced polymer particles iJ were 0.05 to 0.5 microns.

[Brief explanation of the drawing]

The drawing shows the relationship between the rotational speed of the centrifugal separation machine and the water content of the succinic acid peroxide composition after dehydration.

Claims (1)

[Claims] A safe and easy-to-handle phosphoric acid peroxide composition comprising 10 to 25 weight percentages of water and succinic acid peroxide.