JPS643122B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to antifoaming agents. More specifically, the present invention relates to an antifoaming agent that is excellent in suppressing foaming caused by organic solvents, particularly organic solvent solutions containing water and oil repellents. A large number of various antifoaming agents have been proposed in the past, such as (1) those containing polydimethylsiloxane, polyphenylmethylsiloxane, polypropylmethylsiloxane, etc. as main components, or those containing these as main components, such as hydrocarbon oils, polyether oils, etc. Silicone antifoaming agents such as those made into oil compositions such as those or those compounded with finely powdered silica etc.
49-109276, 48-36084), (2)
Polyalkylene glycols such as polyethylene glycol and copoly (ethylene glycol/propylene glycol) (see Japanese Patent Publication No. 1475-1975), (3) Polyvalent metal soaps (see Japanese Patent Publication No. 11328-1977), (4) Alkylins Examples include acid esters and alkyl phosphite esters (see Japanese Patent Publication No. 12177/1983). All of these are mainly aimed at defoaming aqueous solutions and emulsions, and some are also aimed at organic solvent solutions.
The effect is small. That is, although these antifoaming agents can eliminate foam using water/hydrocarbon surfactants, they cannot eliminate foam based on organic solvents, which have a lower surface tension. In addition, ordinary fluorine-based surfactants with the structure shown below have the effect of eliminating organic solvent-based foam.
It cannot be said that it is particularly excellent. Rf-R Rr: Lipophobic group (or hydrophobic group) R: Lipophilic group (or hydrophilic group) In particular, organic solvents are recovered from water and oil repellents made from organic solvent solutions of polyfluorocarbon group-containing copolymers. In some cases, foaming occurs violently, and it is practically impossible to suppress foaming in such systems using commonly used antifoaming agents. The present inventors have conducted various studies in search of an antifoaming agent that has an excellent effect of suppressing foaming caused by organic solvents, particularly organic solvent solutions containing water and oil repellents, and have found that trifluorochloro polymers are extremely effective. I discovered that. Accordingly, the present invention relates to an antifoaming agent, which antifoaming agent comprises as an active ingredient a trifluorochloroethylene polymer, preferably a trifluorochloroethylene polymer having a viscosity of about 0.1 to 1000 centistokes (25 DEG C.). As trifluorochloroethylene polymer,
Not only trifluorochloroethylene homopolymer, but also trifluorochloroethylene and trifluoromethyl vinyl ether, perfluoroalkyl perfluorovinyl ether, perfluoroethylene, perfluoropropylene, alkyl acrylate, alkyl methacrylate, diene monomer, styrene Copolymers with monomers such as acrylamide, methacrylamide, vinyl halides, vinylidene halides, etc. are used. When a copolymer is used, the objects of the present invention cannot be achieved unless trifluorochloroethylene is copolymerized in an amount of at least about 60% by weight in the copolymer. Antifoaming agents are prepared using these trifluorochloroethylene polymers by dissolving or dispersing the polymers in an organic solvent. In order to achieve such dissolution or dispersion of the polymer, it is preferable that the polymer be in a liquid or oily state. used. The antifoaming agent may be the liquid or oily polymer itself, but it is generally used after being diluted to about 1%, preferably about 10%. For dilution, organic solvents such as methanol, ethyl acetate, butyl acetate, methyl isobutyl ketone,
Benzene, toluene, xylene, kerosene, carbon tetrachloride, trichloroethylene, 1,1,2-trifluoro-1,2,2-trichloroethane, fluorocarbons, and the like are used. The antifoaming agent according to the present invention has an excellent effect of suppressing foaming caused by an organic solvent, particularly an organic solvent solution containing a water and oil repellent. Water and oil repellents are
Usually, a copolymer of about 10 to 75% by weight of a vinyl monomer having a perfluoroalkyl group and about 90 to 25% by weight of another vinyl monomer is mixed with 1,1,1-trichloroethane, 1,1, 2,2-tetrachloroethylene,
Trichlorethylene, toluene, xylene, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, 1,2,2-trifluoro-1,1,2
-About 5 to 35 for trichloroethane, fluorocarbons, etc.
It is prepared by dissolving it in a concentration of % by weight. Organic solvent solutions containing such water and oil repellents include:
For example, there are dry cleaning solutions containing water and oil repellents, and the foaming that occurs when perchloroethylene is recovered from these solutions can be effectively prevented by adding the antifoaming agent of the present invention. .
In addition, it is effective in defoaming polyacrylate-based or polyurethane-based paints, silicone-based varnishes, and the like. The antifoaming agent added is about 0.1 to 100% by weight, generally about 0.5% by weight, based on the solid content or nonvolatile content of water and oil repellents, paints, varnishes, etc.
It is used in a proportion of ~10% by weight. The antifoaming agent according to the present invention has an excellent effect of suppressing foaming caused by an organic solvent, especially an organic solvent solution containing a water and oil repellent, and moreover, it has almost the original effect of a water and oil repellent. It won't cause any damage. Next, the present invention will be explained with reference to examples. Note that the reference examples describe a method for producing a polymer as an antifoaming agent used in the examples. Reference example 1 100 ml of 1,1,2-trifluoro-1,2,2-trichloroethane, 10.0 g of trifluorochloroethylene, 0.5 g of azobisisobutyronitrile and 0.5 g of n-dodecylmercaptan, in a volume of 200
The mixture was placed in a stainless steel autoclave of 1.0 ml, and after the atmosphere was sufficiently purged with nitrogen, a polymerization reaction was carried out at 70 to 80° C. for 48 hours. After the reaction was completed, the solvent was removed, yielding 9.3 g of poly(trifluorochloroethylene) having a viscosity of 22 centistokes (25° C.). Reference example 2 1,1,2-trifluoro-1,2,2-trichloroethane 100ml, perfluoropropyl vinyl ether 2.0g, azobisisobutyronitrile
0.5 g and n-dodecyl mercaptan 0.5 g,
The mixture was placed in a stainless steel autoclave with a capacity of 200 ml, and the temperature was adjusted to 70°C after the atmosphere was sufficiently purged with nitrogen. 8.0 g of trifluorochloroethylene is injected therein over a period of 2 hours. After polymerization reaction at 70-80°C for 4 hours, the solvent was removed to obtain 9.5g of trifluorochloroethylene-perfluoropropyl vinyl ether copolymer having a viscosity of 17 centistokes (25°C). Example 1 A water and oil repellent made of a 1,1,1-trichloroethane solution of perfluorooctylethyl acrylate-cyclohexyl acrylate (weight ratio 50:50) copolymer was diluted with perchlorethylene to a concentration of 0.5%, 5% to the polymer in this diluted solution.
A considerable amount of the antifoaming agent obtained in Reference Example 1 is added.
10 ml of this solution was placed in a stoppered test tube with an inner diameter of 15 mm and a capacity of 25 ml, and was vigorously shaken up and down 10 times, and the height of the bubbles was measured in 0.5 ml units immediately and 60 seconds later. Example 2 In Example 1, a perfluorooctylethyl acrylate-benzyl methacrylate (weight ratio 50:50) copolymer was used as the copolymer. Examples 3 to 5 In Example 1, a commercially available water and oil repellent was used instead of the water and oil repellent made of a copolymer solution. (Example 3) Asahi Glass Product AG-650 (Example 4) Kao Soap Product Wonder Guard (Example 5) Genbu Product Social Finish The results of the foaming test are shown in Table 1 below. Data for the case without adding an antifoaming agent are also listed there.

[Table] Example 6 In the water and oil repellent solution used in Examples 1 to 5,
The antifoaming agent obtained in Reference Example 2 was added in an amount equivalent to 5% of the polymer in this solution, and a foaming test was conducted. The results obtained are shown in Table 2 below.

[Table] Examples 7 to 11 In Example 6, Daifloil (Daikin product), which is a commercially available poly(trifluorochloroethylene), was used as an antifoaming agent. The results of the foaming test are shown in Table 3 below.

[Table] Examples 12 to 14 In Example 6, commercially available poly(trifluorochloroethylene) halocarbon oil (Japan Machinery product) was used as an antifoaming agent. The results of the foaming test are shown in Table 4 below.

[Table] Example 15 To the solution with or without antifoaming agent in Table 1 above,
A twill cloth (65% cotton, 35% polyester) was soaked and tested for water and oil repellency. As shown in the results in Table 5 below, it can be seen that the water and oil repellency hardly deteriorates even with the addition of an antifoaming agent.

[Water repellency test]

Drop a drop of water onto the treated twill cloth and
The condition was observed after a minute had elapsed.

[Table] [Oil repellency test] One drop of the test solution (mixed solution in a specific proportion shown in the table below) is dropped onto the treated twill cloth, and the condition is observed after 5 minutes have elapsed. If the dropped test solution is retained on the cloth, test with a test solution with higher n-heptane content, and conversely, if it is not retained on the cloth, test with a test solution with higher n-heptane content. do. Then, using the test liquid that can be retained on the cloth at its limit, the oil repellency is evaluated based on the oil repellency evaluation shown in the table below. In the oil repellency evaluation, the case where 100% Nudyol is retained is 50, and the case where 100% Nudyol is not retained is 0.

[Table] Not held)

Claims (1)

[Scope of Claims] 1. An antifoaming agent containing a trifluorochloroethylene polymer as an active ingredient. 2 Viscosity approximately 0.1 to 1000 centistokes (25℃)
The antifoaming agent according to claim 1, wherein the trifluorochloroethylene polymer is used. 3. The antifoaming agent according to claim 1, which is added to an organic solvent-based object to be defoamed. 4. The antifoaming agent according to claim 3, which is added to an object to be defoamed in an organic solvent solution containing a water and oil repellent.