JP2002177705A - Antifoaming agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel antifoaming agent effective for suppressing foaming and defoaming the generated foam in various industrial fields. SOLUTION: The antifoaming agent consists of a polyoxyethylene fatty ester expressed by general formula (1). In the formula, the content of >=18C acryl group having >=1 unsaturated bond is 75-85 wt.% per total acryl group and the content of 18C acyl group having 1 piece of unsaturated bond is 45-75 wt.% per the >=18C acryl group having >=1 unsaturated bond in the acyl group R1CO, R2 represents hydrogen or CO-R1, EO represents oxyethylene group, PO represents oxypropylene group, (p) and (q) have respectively individual value, (p) represents an integer of 0-5, (q) represents an integer of 1-5 and (p+q) represents an integer of <5, EO group and PO group can be arrayed in an optional order and formed by random polymerization or block polymerization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel antifoaming agent, and more particularly, to a method for suppressing foaming in various industrial fields or reducing foaming effects which are effective in defoaming generated foams. To provide an antifoaming agent.

[0002]

2. Description of the Related Art In many industrial fields, there have been examples in which the generation of bubbles causes a great obstacle, thereby reducing productivity and, in some cases, making it difficult to continue production.

[0003] For example, the production of synthetic rubber latex, the production of aqueous emulsion paints and adhesives, the fermentation industry, the production of phosphoric acid, the pulp production and papermaking process in the papermaking industry, the refining and dyeing processes in the textile industry, the treatment of industrial wastewater, In the treatment of domestic wastewater and the like, suppression of bubbles generated in the process and defoaming of generated bubbles are industrially important issues. Conventionally, in these various industries, for example, mineral oils such as spindle oils and machine oils, higher alcohols, fatty acids, fatty acid amides, metal soaps (such as calcium soaps), and silicone-based compounds are added, and the surfactant is vapor-liquid. Treatments have been taken, such as removal from the interface or changing the gas-liquid interface film to a hard and brittle nature. These defoaming treatments are not only ineffective, but also, for example, in the paper industry, mineral oils are insoluble in water, contaminating machinery and generating oil spots on the papermaking surface. It causes the deterioration of paper quality. In addition, since silicone-based ones generate insoluble scum when added to the foaming liquid, the scum has the drawback of causing mechanical contamination, soiling the surface of papermaking paper, and deteriorating the quality of paper.

[0004] Under such circumstances, a fatty acid ester type or higher alcohol ether type antifoaming agent to which a polyoxyethylene group or a polyoxypropylene group is added and a composition thereof are expected in view of a foam suppressing effect and a defoaming effect. Many techniques that act as defoamers have also been disclosed. As a polyoxyalkylene-added higher alcohol type antifoaming agent,
Japanese Patent Publication No. 9-38923 discloses a papermaking defoamer obtained by adding propylene oxide and ethylene oxide to a higher alcohol.
An antifoam as an emulsion of a higher alcohol ethoxylate and an alkylpolysiloxane or silica is disclosed.

Japanese Patent Publication No. 45-7973 discloses a polyoxyalkylene-added higher fatty acid type antifoaming agent, which contains 5 to 20% by weight of a saturated or unsaturated fatty acid having 8 to 22 carbon atoms, 5 to 40% by weight of ethylene oxide, Propylene 40-9
A polyoxyalkylene-added higher fatty acid type defoamer synthesized at a ratio of 0% by weight is disclosed in Japanese Patent Publication No. 50-5 / 1985.
No. 157 discloses an antifoaming agent containing a higher alcohol ester of an ethylene oxide adduct of a higher fatty acid or a higher alcohol ester of a propylene oxide adduct of a higher fatty acid.

These antifoaming agents are controlled by controlling the order of addition and the number of moles of alkylene oxide.
It is useful because it can exhibit various defoaming effects. But,
In recent industries, for example, increasing the stirring speed when mixing liquids and increasing the flow velocity in pipe transport are frequently performed to improve productivity and streamline, so that bubbles are more likely to be generated. Has become. Furthermore, as seen in the paper industry, white water has been closed from the environmental aspect,
The concentration and temperature of white water increase, and conventional types of antifoaming agents cannot cope. In addition, recycling paper increases collection of resources,
Along with that, a deinking agent and the like are mixed in, creating an environment where foaming is more likely. For this reason, the above-mentioned antifoaming agents which have been used up to now have insufficient antifoaming effect, and the amount of the antifoaming agent must be increased, and the antifoaming effect, that is, the rapid effect and sustainability are remarkably improved. And cheaper ones for economic reasons.

On the other hand, conventional oxyalkylene-introduced higher fatty acid ester-type or higher alcohol-type defoamers are used in an amount of 5 mol / mol of fatty acid or higher alcohol in order to sufficiently exhibit the defoaming effect. -10 mol or more,
In some cases, a material to which 20 mol or more of oxyalkylene has been added is used in order to achieve both water dispersibility and defoaming effect. However, the conventional antifoaming agent that introduces a long-chain polyoxyalkylene chain that acts rate-limiting during biodegradation has insufficient biodegradability. From the viewpoint of environmental protection, naturally-occurring biodegradable materials are also required.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel defoaming agent which is effective for suppressing foaming in various industrial fields and for defoaming generated foams.

[0009]

As a result of intensive studies to solve the above problems, the alkylene oxide has a low molar ratio which is considered to have a lower foam-suppressing effect than the conventional lipophilic group in a specific range. It has been found that a specific polyoxyalkylene fatty acid ester to which is added an excellent defoaming effect and an antifoaming effect.

That is, the present invention provides a compound represented by the following general formula (1):

[0011]

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Wherein the acyl group R ₁ CO has a content of 75 to 85% by weight of an acyl group having at least one unsaturated bond having 18 or more carbon atoms per acyl group,
And the content of the acyl group having one unsaturated bond having 18 carbon atoms is 45% to 75% of the acyl group having one or more unsaturated bonds having 18 or more carbon atoms, and R ₂ is hydrogen or CO-R ₁ , EO represents an oxyethylene group, PO represents an oxypropylene group, p and q are
P is an integer of 0 to 5; q is an integer of 1 to 5; and p + q is an integer of less than 5;
The O groups may be arranged in any order and each may be randomly or block polymerized. And a defoaming agent comprising a polyoxyalkylene fatty acid ester represented by the formula:

More preferably, the present invention relates to an antifoaming agent wherein the raw fatty acid constituting the acyl group of the polyoxyalkylene fatty acid ester represented by the general formula (1) is rice bran fatty acid.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the antifoaming agent of the present invention will be described in detail.

The antifoaming agent of the present invention is a compound represented by the general formula (1), and has a lipophilic group (acyl group:
R ₁ CO) and a specific range of oxyalkylene groups.

The condition of the lipophilic moiety can be controlled by controlling the fatty acid composition of the raw material for synthesis. One of the lipophilic group conditions of the present invention is that the number of carbon atoms per acyl group is 18
The content ratio of the acyl group having one or more unsaturated bonds is 75 to 85% by weight. Furthermore, carbon number 18
And the content of the acyl group having one unsaturated bond is 1 carbon atom.
The ratio is 45% to 75% with respect to an acyl group having one or more unsaturated bonds of 8 or more.

The antifoaming agent of the present invention can be obtained by mixing oleic acid, linoleic acid and other fatty acids isolated and purified within the scope of the present invention. It is more cost effective to use a fatty acid as a raw material fatty acid.

Examples of natural fatty acids satisfying the lipophilic condition of the present invention include peanut (Spanish) seed oil, peanut oil, rice bran oil, peanut (Virginia) seed oil, pumpkin seed oil, and the like. From the viewpoint of raw material cost, fatty acids derived from rice bran oil are particularly preferred.

The composition of the acyl group of the natural fatty acid satisfying the lipophilic condition is shown in Table 1 below.

[0020]

[Table 1]

Conventionally, it has been considered that a higher fatty acid polyoxyalkylene-added type defoaming agent has less emulsifiability and defoaming property due to a decrease in molecular occupied area when the number of moles of polyoxyalkylene added is small. When an alkylene oxide is actually added to a fatty acid composition that is not within the scope of the present invention, the defoaming effect is not effectively exhibited even if the alkylene oxide is added in a low molar number (1 to 5 mol).

However, it has been found that when an alkylene oxide is added to the fatty acid in the range of the present invention, an effective defoaming effect can be obtained even in a range where the number of moles of the alkylene oxide added is small.

Ethylene oxide is added to the natural fatty acid or mixed fatty acid satisfying the acyl group condition of the present invention in an amount of 0 to 5 mol, preferably 1 to 3 mol, and then propylene oxide is added in an amount of 1 to 5 mol, preferably 1 to 3 mol. The desired antifoaming agent can be obtained by the addition. The defoaming effect can be obtained even if the above addition conditions are satisfied, for example, a combination of 5 moles of ethylene oxide and 5 moles of propylene oxide. However, when the total number of moles of ethylene oxide and propylene oxide exceeds 5, the defoaming effect is obtained. No increase in the foaming effect is observed, and the longer the oxyalkylene chain is set, the worse the biodegradability of the antifoaming agent becomes, and only the influence on the external environment is undesirably increased.

When more than 5 mol of ethylene oxide is added, the balance between the hydrophilicity and lipophilicity (HLB) of the molecule is too high in the fatty acid composition of the antifoaming agent of the present invention, and the defoaming effect is undesirably reduced. . Further, even if propylene oxide is added in excess of 5 mol, no increase in the defoaming effect is observed, and the oxypropylene group itself has low biodegradability.

The order of the addition polymerization of the oxyalkylene is not particularly limited, but more effectively, the structure having the terminal terminated with an oxypropylene group tends to have stronger defoaming performance.

The antifoaming agent of the present invention can be produced by subjecting a fatty acid and an alkylene oxide to an addition reaction by a known method within the scope of the present invention. For the addition of ethylene oxide and propylene oxide, commonly used alkali catalysts such as potassium hydroxide, sodium hydroxide, sodium methoxide and potassium tert-butoxide can be used.

The amount of the catalyst is 0.1 to the amount of the substrate fatty acid.
It can be used in the range of 01 to 10 mol%.

The addition reaction of ethylene oxide and propylene oxide can be carried out at a temperature of 80 to 180 ° C. under a pressure of, for example, 0.02 to 1.0 MPa.

The antifoaming agent thus obtained can be used as it is, but can be used in combination with other antifoaming agents. Further, it can be used as an antifoaming agent which is made into an emulsion in water together with the above components.

[0030]

EXAMPLES The present invention will be described below with reference to examples.

Production Example 1 To 300 g of rice bran fatty acid having a molecular weight of 300, 1 g of potassium-t-butoxide was added as a catalyst, and 44 g of ethylene oxide was added at 140 ° C. under pressure. Continue 12
At 0 ° C., 58 g of propylene oxide was added to obtain a pale yellow transparent liquid. The resulting absorbed 1740 cm ^-1 was measured for IR ester compounds, CH ₂ -O-CH ₂ bond absorption of the 1,120 cm ^-1, absorption of OH group was observed at 3250cm ^-1, the compounds are intended It was confirmed that it was obtained.

Similarly, ethylene oxide and propylene oxide were added at the molar ratios shown in Table 2. Each of the obtained products was a pale yellow liquid, and an IR spectrum similar to that of Production Example 1 was obtained.

[0033]

[Table 2]

Test Method A magnet lab pump “manufactured by Iwaki Glass Co., Ltd.” was attached to a glass cylinder with memory, 700 mL of a foaming liquid and an antifoaming agent were charged, circulated for 2 minutes, and then stopped. The foam volume (mL) was read immediately before the stop and 5 seconds after the stop, and the effect was measured.

Foaming liquid composition: polyoxyethylene (10)
Oleyl ether nonionic surfactant 10 ppm aqueous solution, foaming liquid amount: 700 mL Antifoaming agent addition amount: 15 ppm based on the foaming liquid

Table 3 shows the test results.

[0037]

[Table 3]

* Commercial product (A): Higher alcohol propylene oxide addition type defoaming agent Alkyl carbon number 14, propylene oxide addition mole number 4 ** Commercial product (B): Higher fatty acid ethylene oxide propylene oxide copolymer ester defoamer Agent fatty acid carbon number 16, ethylene oxide / propylene oxide = 10 /
30

Example 2 The same test as in Example 1 was carried out by changing the composition of the foaming liquid and the amount of the defoamer added as follows.

Foaming liquid composition: 10 ppm aqueous solution of sodium polyoxyethylene lauryl sulfate anionic surfactant Defoaming agent added amount: 15 ppm based on the foaming liquid

Table 4 shows the test results.

[0042]

[Table 4]

*, ** Commercial products (A) and commercial products (B) are the same as in Table 2.

Example 3 The same test as in Example 1 was carried out by changing the composition of the foaming liquid and the amount of the defoamer added as follows.

Blowing liquid composition: pseudo white water. The adjustment method is as follows. A liquid containing 900 ppm of a rosin sizing agent and 600 ppm of an anionic polyacrylamide resin was adjusted to pH = 4.5 with aluminum sulfate. Further, 600 ppm of a polyamide epoxy resin was added. The foaming liquid volume was 700 mL.

Addition amount of antifoaming agent: 15 ppm based on the foaming liquid

Table 5 shows the test results.

[0048]

[Table 5]

*, ** Commercial products (A) and commercial products (B) are the same as in Table 2.

From the results in Tables 2 to 4, it can be seen that the antifoaming agents (1) to (4) of the present invention are very stable and exhibit excellent antifoaming effects in all of Examples 1 to 3.

[0051]

The defoaming agent of the present invention can provide a defoaming agent which is advantageous in terms of performance, economy, and especially environment in a paper mill.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirotaka Sekido 1-3-34 Kitafu, Takefu-shi, Fukui Prefecture Inside Takefu Fine Chemical Co., Ltd. Inventor Hisao Takatsu 1 in Nakaseicho, Nishikyogoku, Ukyo-ku, Kyoto-shi, Kyoto, Japan Meijiri Chemical Industry Co., Ltd. (72) Masato Iimura 1 Nakazawa-cho, Nishikyogoku, Ukyo-ku, Kyoto, Kyoto Prefecture F-term in Meisei Chemical Co., Ltd. 4D011 CB04 4J005 BD02

Claims (2)

[Claims] 1. A compound of the general formula (1) [However, in the formula, the acyl group R ₁ CO has a content of an acyl group having at least one unsaturated bond having 18 or more carbon atoms in the entire acyl group of 75 to 85% by weight, and has 1 to 1 carbon atoms.
8, the content of the acyl group having one unsaturated bond is 45% to 75% of the acyl group having one or more unsaturated bonds having 18 or more carbon atoms, and R ₂ is hydrogen or CO 2
Indicates -R _1, EO represents an oxyethylene group, PO represents an oxypropylene group, p and q are, independently p is an integer of 0 to 5, q is an integer a and p + q 1-5 5 And the EO group and the PO group may be arranged in an arbitrary order, and each may be randomly polymerized or block polymerized. ] An antifoaming agent comprising a polyoxyalkylene fatty acid ester represented by the formula: 2. The antifoaming agent according to claim 1, wherein the acyl group constituting the polyoxyalkylene fatty acid ester represented by the general formula (1) is an acyl group of rice bran fatty acid.