RU2325211C2 - Compound for foam-forming decreasing - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: compound for foam-forming decreasing includes polyatomic alcohol, emulsifier and water; component ratio is as follows: polyatomic alcohol 0.03-1.0 Wt%; emulsifier 0.03-1.0 Wt%; water - the rest.

EFFECT: increasing of defoaming capability; maintenance of rubbers quality.

2 cl, 3 tbl, 4 ex

Description

The invention relates to the production of compositions to reduce foaming, in particular during aqueous degassing of solutions of synthetic rubbers (polymerizates) in the presence of anti-agglomerators containing a suspension of calcium stearate and antifoam, and can be used in the manufacture of synthetic latexes and rubbers.

Known antifoam compositions, which are aqueous emulsions based on polymethylsiloxane (PMS) (Chistyakov B.E., Melnik N.A., Chernin V.N. Chemical defoamers. - M .: TSNIITEneftekhim. - 1989. - 36 p.). The disadvantages of these compositions include the low efficiency of antifoam agents and the high cost of polymethylsiloxane.

Closest to the proposed technical essence is a composition for reducing foaming during latex degassing, containing polymethylsiloxane, polyethylene glycol esters of synthetic primary fatty alcohols as an emulsifier and water (AS USSR No. 545653, class C08L 83/04, publ. 25.02. 1977, bull. No. 5). A disadvantage of the known composition is that polymethylsiloxanes worsen the physico-mechanical properties of rubbers and rubbers based on them (Lazurin EA, Kosmodemyansky LV, Furina TP. Obtaining rubbers in the form of non-stick particles. - M .: TSNIITEneftekhim. - 1984. - 38 p.).

The aim of the invention is to obtain a cheaper and more effective composition to reduce foaming, which when applied in the process of degassing does not impair the physical and mechanical properties of rubbers and rubbers based on them.

This is achieved by the fact that the composition contains a polyhydric alcohol as a defoaming agent, for example glycerin, which also contains a fraction of low molecular weight polyethylene with a molecular weight of 300 to 1000 and a surfactant, for example, water-soluble soaps of higher fatty acids.

According to the invention, the composition contains (in wt.%):

Polyhydric alcohol - 0.03-1.0;

Emulsifier OP-10 - 0.03-1.0;

Water is the rest.

Emulsifier OP-10 is a product of processing a mixture of mono- and dialkylphenols with ethylene oxide (GOST 8433).

The effectiveness of antifoam is evaluated by the antifoam ability E, calculated by the formula

E = W / τ,

where W is the volume of foam formed in the liquid with the addition of antifoam, cm ³ ;

τ is the settling time of the foam formed in the liquid with the addition of antifoam.

An emulsion of the claimed composition containing a polyhydric alcohol, an emulsifier OP-10 and water is prepared according to the prescription of an antifoam based on PMS at a temperature of 60-70 ° C and with stirring.

Example 1. In an installation consisting of a glass vessel with a sealed perforated septum, 50 ml of potassium stearate (or latex) are poured and air is supplied at a rate of 4.5 dm ³ / h, which sparges through potassium stearate (or latex) and creates a foam. An antifoam emulsion containing 0.05 wt.% Polyhydric alcohol, which has the following ratio of components: polyhydric alcohol: low molecular weight polyethylene: surfactant = 100: 0: 0 (wt.%), As well as 0.05 wt.% Of the emulsifier OP-10 and water - the rest is served from above and the height of the foam column is used to judge the effect of defoaming. The antifoam consumption is calculated based on the amount of emulsion applied per 1 ton of rubber.

Example 2. Under the same conditions, an antifoam emulsion is supplied containing 0.05 wt.% Polyhydric alcohol, which has the following ratio of components: polyhydric alcohol: low molecular weight polyethylene: surfactant = 94: 5: 1 (wt.%), As well as 0, 05 wt.% Emulsifier OP-10 and water - the rest.

Example 3. (prototype). Under the same conditions, an antifoam emulsion containing 0.05 wt.% PMS, 0.05 wt.% Of the emulsifier OP-10 is fed, water - the rest.

Example 4. Under the same conditions, an antifoam emulsion is supplied containing 0.1 wt.% Polyhydric alcohol, which has the following ratio of components: polyhydric alcohol: low molecular weight polyethylene: surfactant = 94: 5: 1 (wt.%), 0.1% emulsifier OP-10, water - the rest.

Example 5. (prototype). Under the same conditions, an antifoam emulsion containing 0.1 wt.% PMS, 0.1 wt.% Of the emulsifier OP-10 is fed, water - the rest.

Data on the quality of defoaming are given in table 1.

Table 1 Antifoam Efficiency Antifoam agent Dosage of antifoam,% τ, s E, cm ³ / s According to example 1 0.05 64.0 0.78 According to example 2 0.05 62.5 0.80 For example 3 0.05 65.7 0.76 For example 4 0.10 39.0 1.28 For example 5 0.10 71,4 0.70

From the data presented in table 1, it follows that the inventive antifoam at a dosage of 0.05 wt.% Is not inferior in effectiveness to the defoamer of the prototype, and at a concentration of 0.1 wt.% It exceeds 1.8 times.

Table 2 presents the physicomechanical properties of rubber SKI-3, during degassing of which the inventive defoamer and antifoam were used according to the prototype.

table 2 Plasto-elastic properties of SKI-3 rubber and physical and mechanical properties of unfilled vulcanizates based on it Name of indicator Antifoam agent According to the prototype (PMS) According to the claimed composition Plasto-elastic properties of rubber Mooney viscosity, units Mooney 73.5 70.3 Mooney viscosity coefficient of heat resistance (120 ° C × 30 min) 0.85 0.89 Physico-mechanical properties of unfilled vulcanizates Conditional strength at elongation of 500%, MPa 1.9 1.9 Conditional tensile strength, MPa 32,3 33.6 Relative extension, % 870 880

From the data presented in table 2, it follows that the use of antifoam according to the claimed composition allows to obtain rubber and unfilled vulcanizates based on it with an improved complex of plasto-elastic and physico-mechanical properties.

The inventive antifoam composition was also used to reduce foaming during degassing of styrene-butadiene latex. Table 3 presents the costs of antifoam, providing the same reduction in the volume of foam, which confirms the reduction in consumption when using the inventive antifoam.

Table 3 Antifoam Efficiency Latex obtained on emulsifiers Defoamer consumption, kg / t ICP Polyhydric alcohol Ditalp-A 0.14 0.018 Ditalp-B 0.41 0,060

Thus, it is shown that the use of the proposed composition for degassing rubbers allows to increase the antifoam ability by 1.8 times, while the quality of the rubber remains at a high level, when degassing latexes it allows to reduce the dosage of antifoam by 7 times.

Claims (2)

1. A composition for reducing foaming, containing a defoaming agent, an emulsifier and water, characterized in that it contains a polyhydric alcohol as a defoaming agent in the following ratio of components, wt.%: Polyhydric alcohol - 0.03-1.0, emulsifier OP- 10 - 0.03-1.0, water - the rest. 2. The composition according to claim 1, characterized in that the polyhydric alcohol further comprises a fraction of low molecular weight polyethylene with a molecular weight of 300-1000 and a surfactant.