JPH06179862A - Modification of chemical blowing agent - Google Patents

Abstract

PURPOSE:To provide a chemical blowing agent improved in flow and solidification preventive properties without substantially affecting its purity and without detriment to the quality of the produced foam. CONSTITUTION:A chemical blowing agent is treated with a silane coupling agent.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for modifying a chemical foaming agent.

[0002]

2. Description of the Related Art Chemical blowing agents are usually fine powdery compounds, and like ordinary inorganic and organic powders, they deteriorate the quality of products due to solidification over time and cause poor dispersion in resins. Have problems such as.

In order to solve such problems, presently (1) a method of adding an inorganic anti-caking agent, (2) a method of increasing the particle size of the chemical foaming agent, (3) drying of the chemical foaming agent. A method of reducing the adhering moisture by using a batch method is adopted.

However, when these methods are adopted, various drawbacks occur. That is, in the method (1),
Although there is no particular problem with foaming of polyvinyl chloride, there are many problems with foaming of a polyolefin resin such as polyethylene because of the quality of the foam, cross-linking, and the effect on the foam manufacturing equipment. The method (2) has a problem that the particle size of the foaming agent greatly affects the quality of the foaming agent, the foaming conditions, the quality of the foam, and the like. Further, the method (3) has a problem that it takes a long time to dry because it is a batch method and the production capacity is considerably lowered.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to solve all of these problems, and has improved flow characteristics and anti-caking properties without affecting the purity of the chemical blowing agent. It is intended to provide a chemical foaming agent which imparts the above properties and does not impair the foaming quality characteristics.

That is, the present invention relates to a method for modifying a chemical foaming agent, which comprises treating the chemical foaming agent with a silane coupling agent.

The chemical foaming agent treated in the present invention includes:
As long as it is in powder form, conventionally known compounds can be widely used, and examples thereof include azodicarbonamide, p, p′-oxybisbenzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, benzenesulfonyl hydrazide, and dinitrosopentamethylenetetramine. it can.

The silane coupling agent used in the present invention is not particularly limited and widely known ones can be widely used. For example, γ-aminopropyltrimethoxysilane,
γ- (2-aminoethyl) aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane,
Trimethoxysilylpropyldiethylenetriamine, γ
Examples thereof include-(2-aminoethyl) aminopropyltrimethoxysilane. The amount of such a silane-based coupling agent used is not particularly limited and may be appropriately selected from a wide range, but is usually 0.0 with respect to the chemical blowing agent.
It is preferable to set it to about 1 to 50% by weight. If the amount of the silane coupling agent used is too small, the intended effect of the present invention tends to be difficult to be exhibited. On the other hand, if the amount of the silane coupling agent used is too large, the desired effect of the present invention will be further exhibited, but the cells during foaming will tend to be affected. In the present invention, it is preferable to use the silane coupling agent in an amount of about 0.1 to 1% by weight with respect to the chemical foaming agent in consideration of economy.

When the chemical blowing agent is treated with the silane coupling agent, it is preferable to put both in a mixer which is usually used for mixing, for example, a Henschel mixer. At this time, the silane coupling agent may be added directly (dry method) or may be dissolved in an appropriate organic solvent and added (wet method).

[0010]

The chemical foaming agent treated by the method of the present invention has extremely good fluidity as compared with that before the treatment and has sufficiently improved solidification property over time, resulting in good dispersibility in the resin. It was an excellent product with no deterioration in quality. The treatment of the present invention has little adverse effect on the purity of the chemical blowing agent. Therefore, according to the present invention, from the production of the chemical blowing agent to the shipment, and the stock from the shipment to the use by the user,
It was possible to eliminate the anxiety that the product solidified over time at the distribution stage.

[0011]

EXAMPLES The present invention will be further clarified with reference to the following examples. In addition, simply saying "%" means "% by weight"
"Parts" means "parts by weight", respectively.

Example 1 Azodicarbonamide (ADCA), p, p'-oxybisbenzenesulfonyl hydrazide (OBSH) or dinitrosopentamethylenetetramine (DPT) was added to γ-aminopropyltrimethoxysilane [S-330, Chisso ( Co., Ltd.] or γ- (2-aminoethyl) aminopropyltrimethoxysilane [SH-6020, manufactured by Toray Silicone Co., Ltd.] at an addition amount shown in Table 1 below and added with a super mixer at 600 rpm for 5 minutes. A sample was prepared by mixing.

400 g of each sample is 23 cm × 13 cm
The plastic bag was filled in, and after degassing sufficiently, the opening was heat-sealed and stacked, and a load of 0.07 kg / cm ² was applied from above. After 2 weeks, the sample was taken out, sieved with a 14-me sieve to measure the amount of non-passing substances, and converted into% to obtain the solidification test value. Table 1 shows the obtained deposition solidification test value of each sample. For comparison, a sample without addition of a silane coupling agent was similarly obtained with a solidification test value, and the results are also shown in Table 1.

[0014]

[Table 1]

According to Table 1, the deposition solidification test value greatly decreases as the amount of the silane coupling agent added increases, and it is understood that the solidification prevention effect is high.

Example 2 In the same manner as in Example 1, azodicarbonamide [ADC
A, average particle diameter 10 μ, decomposition temperature 200 ° C.) was mixed with a silane coupling agent to prepare a sample.

The angle of repose and the degree of compression of each sample were examined by using a Bowder tester [Powder property comprehensive measuring device, PT-E type, manufactured by Hosokawa Micron Co., Ltd.]. The degree of compression is calculated from the loose apparent specific gravity (A) and the solid apparent specific gravity (P) according to the following equation.

C = 100 × (PA) / P (%) The results are shown in Table 2. For comparison, the same measurement was performed on a sample to which a silane coupling agent was not added, and the results are also shown in Table 2.

[0019]

[Table 2]

From Table 2, it can be seen that the silane coupling agent-treated product has greatly improved powder characteristics such as angle of repose and compressibility.

Example 3 Of the samples prepared in Example 2 above, a 0.2% S-220 mixed sample was subjected to an actual packaging solidification test. That is, 25 kg of the sample is packed and packed in a cardboard case which is a product distribution package, left for 1 month under the condition of temperature of 40 ° C. and humidity of 80%, and then sieved with a 14 me sieve to determine the amount of non-passages. The value obtained by measuring and converting to% was used as the actual packaging solidification test value. Table 3 shows the actual packaging solidification test values of the obtained samples. For comparison, the actual package solidification test value was similarly obtained for the sample to which the silane coupling agent was not added, and the results are also shown in Table 3.

[0022]

[Table 3]

From Table 3, it can be seen that the product treated with the silane coupling agent was hardly solidified even after the abuse test for one month, and the fluidity was very good.

Example 4 1% of S-330 was added to OBSH, and the mixture was processed by a super mixer at 600 rpm for 5 minutes to prepare a sample.

100 parts of polyvinyl chloride [PX-NL, manufactured by Sumitomo Chemical Co., Ltd.], 80 parts of dioctyl phthalate, and 3 parts of stabilizer [FL-44, manufactured by ADEKA ARGUS CHEMICAL CO., LTD.] Were added to a Shinagawa mixer (manufactured by Shinagawa Seisakusho). Put, high speed stirring (15
The mixture was mixed at 0 rpm for 5 minutes to prepare a uniform polyvinyl chloride sol. Next, 5 parts of the sample prepared above was added to this polyvinyl chloride sol, and the mixture was stirred at a low speed (70 rp).
m) was mixed for 2 minutes to produce a foamable sol.

This foaming sol was placed on a release paper and had a thickness of 0.25.
mm, and heated in a hot air oven at 130 ° C. for 60 seconds to obtain a gelled sheet.

On the surface of the gelled sheet thus obtained, the dispersed state of the sample was visually observed. For comparison, the dispersed state of the sample was also observed for the sample to which the silane coupling agent was not added.
The results are shown in Table 4.

[0028]

[Table 4]

It can be seen from Table 4 that the silane coupling agent-treated product has good dispersibility in polyvinyl chloride.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshifumi Tate 649-2 Satoura-cho, Satoura-cho, Naruto-shi, Tokushima Prefecture Otsuka Chemical Co., Ltd. Naruto factory (72) Inventor Yuichiro Adachi Satoura-cho, Satoura-cho, Naruto-shi, Tokushima Prefecture 649-2 Otsuka Chemical Co., Ltd. Naruto Factory

Claims (1)

[Claims] 1. A method for modifying a chemical foaming agent, which comprises treating the chemical foaming agent with a silane coupling agent.