JPS6332485B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an antifoaming agent that has excellent foam-breaking and defoaming effects against foaming problems that occur in various manufacturing industries. Currently, foaming failures often occur in various processes such as the resin emulsion industry, paint industry, textile industry, paper and pulp industry, phosphoric acid manufacturing industry, acrylonitrile manufacturing industry, etc., making it difficult to rationalize processes and solve drainage problems. There is. In such cases, antifoaming agents such as silicone, paraffin, and polyoxyalkylene glycol are used, but it is known that the use of these agents often causes troubles such as adhesion and aggregation during the process. In order to solve these problems, various studies have been carried out in the past, but satisfactory results have not yet been obtained. For example, methods include adding polyoxyalkylene glycol to silicon;
Dispersant for antifoaming agent components such as silicone and paraffin,
Methods such as adding an emulsifier or emulsifying various antifoaming agent components are common, and inventions such as those shown in Japanese Patent Publication No. 45-7973 and Japanese Patent Application Laid-open No. 134785-1987 are also known. . However, none of these has achieved satisfactory results in terms of the balance between antifoaming properties, emulsifying properties, and process inhibition, and there is a long-awaited antifoaming agent with good antifoaming properties that does not inhibit the process. was. The present invention was completed as a result of various studies conducted by the inventors in order to satisfy these demands. The antifoaming agent of the present invention uses the following two types of raw material polyols: A ₁ [-O(C ₃ H ₆ O) _a (C ₂ H ₄ O) _b H] _l (1) A ₂ [-O(C ₃ H ₆ O) _c H] _n (2) (In the formula, A ₁ and A ₂ are residues of l-valent and m-valent alcohols, respectively, l and m are numbers 2 or 3, and may be the same or different. a+b is a number of 5 or more, and a and b are (C ₂ H ₄ O) _b part is (C ₃ H ₆ O) in formula (1).
The present invention is characterized in that at least a partial fatty acid ester of _a + (C ₂ H ₄ O) is in a relationship of 5 to 40% by weight of the chain of _b , and c is a number of 5 or more, is used in combination. As the fatty acid used for esterification, a saturated or unsaturated fatty acid having 10 to 24 carbon atoms can be used.
At least 1 mole of fatty acid is used per mole. There is no particular limit to the length of the oxyalkylene chain in the polyol, but a is 50 or less, b is 20 or less,
It is practical for c to be 50 or less. The mixing ratio of the two types of esters is also not particularly limited, but the effect becomes clear when the ratio of ester from formula (1) to ester from formula (2) is about 1/9 to 9/1. The above-mentioned limitations regarding the antifoaming agent of the present invention are important, and outside these conditions, for example, when the raw material polyalkylene polyol has a low molecular weight, good self-emulsifying properties and antifoaming properties cannot be obtained, and the general formula ( If the weight fraction of ethylene oxide in the polyol (1) is greater than the above specified value, phenomena such as deterioration of antifoaming properties may occur, which is not appropriate. The antifoaming agent according to the present invention is characterized in that a fatty acid ester of a polyol of general formula (1) and a polyol of general formula (2) is used in combination. It is generally known that both components can be used as antifoaming agents, but (1), (2)
None of the esters from the polyols of the formula alone can provide sufficient self-emulsifying properties. The ester from the polyol of formula (2) does not diffuse or emulsify into water at all, but instead floats or settles as an oily substance. Also
The ester from the polyol of formula (1) becomes solubilized in water by increasing the ethylene oxide weight fraction, but in this case it has almost no antifoaming properties.
In addition, when the ethylene oxide weight fraction is appropriate, the emulsion state is exhibited to some extent, but the emulsion stability
Both antifoaming properties are insufficient, and self-diffusion in water is hardly observed. The significance of the present invention is that each single component has poor diffusion into water, does not have sufficient self-emulsifying properties and antifoaming properties, and may also cause process problems. However, by using these two components together, the drawbacks of each can be eliminated and revolutionary antifoaming properties can be achieved.
The goal is to obtain an antifoaming agent that has self-emulsifying properties and self-diffusing properties in water. In the present invention, there is no need to use a commonly used emulsifier component at all, and since it contains only an antifoaming component, there is no adverse effect on antifoaming properties and a good agglomeration effect is achieved. The only thing that can be done is Furthermore, even when this antifoaming agent is blended with mineral oil and used, these properties are not lost, and it is also characterized by being an excellent self-diffusing and emulsifying agent for mineral oil and the like. In this case as well, there is no adverse effect on defoaming performance. In addition, as a method for producing the antifoaming agent of the present invention, even if fatty acid esters of polyoxyalkylene polyols of formulas (1) and (2) are synthesized separately and then mixed, It is also possible to mix the polyoxyalkylene polyol in advance and simultaneously esterify it with a fatty acid. The present invention will be explained in more detail with reference to examples below. Synthesis Example 1 Polyoxypropylene polyoxyethylene block copolymer of propylene glycol (molecular weight
2200, oxyethylene group content 10% by weight) and polyoxypropylene glycol (molecular weight 2000) mixed in a weight ratio of 2:1 and oleic acid as a catalyst at a molar ratio of polyol:oleic acid of 1:2. After reacting with para-toluenesulfonic acid at 110 to 160° C. for 3 hours in a nitrogen atmosphere, the catalyst was precipitated with an alkali and separated to obtain an antifoaming agent. Synthesis Example 2 The polyoxypropylene polyoxyethylene block copolymer and polyoxypropylene polyol shown in Tables 1 and 2 (Example 1 is excluded because it is based on Synthesis Example 1) were each used in Synthesis Example 1.
Esterification was carried out under the same conditions. Examples 1 to 7 and Comparative Examples 1 to 6 Antifoaming agents having the compositions shown in Table 1 below (Example 1
~Example 7 and Comparative Examples 1 to 6) were prepared;
The foam capacity when each antifoaming agent was added was measured. The foam volume was measured as follows. Take 200 ml of a 100 ppm aqueous solution of 10 moles of nonylphenol ethylene oxide adduct in a graduated cylinder, add 0.02 g of the following antifoaming agent, and aerate at a rate of 500 ml/min with a ball filter to foam and measure the foam volume. did.

[Table] Examples 8 to 11 Comparative Examples 7 to 12 Antifoaming test Dodecylbenzene/sodium sulfonate/
Pour 20ml of a 100ppm aqueous solution into a 100ml graduated cylinder with a stopper, add 150ppm of the following antifoaming agent, shake up and down 200 times, and observe the foaming. Emulsion Stability Test Put 2g of the antifoaming agent sample into a 100ml measuring cylinder with a stopper, dilute it to 100ml with water, stir it upside down to make it homogeneous, let it stand, and check the emulsion stability (〇…
…stable, △…slightly unstable, ×…unstable)

【table】

Claims (1)

[Claims] 1 Compounds represented by the general formula A ₁ [-O(C ₃ H ₆ O) _a (C ₂ H ₄ O) _b X ₁ ] _l and the general formula A ₂ [-O(C ₃ H _{6 O ) c _ _}
and m is a number of 2 or 3 and may be the same or different, and X ₁ and X ₂ are hydrogen atoms or the number of carbon atoms
The 10 to 24 fatty acid residues may be the same or different, and different X ₁ and X ₂ may exist in one molecule, but at least of each X ₁ and X ₂ in each compound One is a fatty acid residue, a + b is a number of 5 or more, b is a number such that the ratio of oxyethylene group to the total of oxyethylene group and oxypropylene group is 5 to 40% by weight, and c is 5 or more An antifoaming agent containing a compound represented by