JPS643123B2 - - 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, a water and oil repellent made of an organic solvent solution of a polyfluorocarbon group-containing copolymer was used for dry cleaning. In some cases, when the organic solvent is recovered from the system, foaming is intense, and it is almost impossible to suppress foaming in such a system using a commonly used antifoaming agent. 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, especially organic solvent solutions containing water and oil repellents, and have found that a specific perfluoropolyether compound is extremely effective. I found that. Therefore, _the present invention relates to an antifoaming agent, which has the following general formula RO( _-CF2O ) _-p ( _-C2F4O ) _-q ( _{-C3F 6} O) - _r R′ (where R and R′ are perfluoroalkyl groups that are the same or different from each other, p, q and r are the number of bonds, and p and r can be 0)
The active ingredient is a perfluoropolyether compound represented by The perfluoropolyether compound represented by the above general formula can be obtained by fluorinating a peroxy group-containing polyether (Japanese Patent Publication No. 49-45719) or by using the general formula XCF ₂ CF ₂ O (-CFXCF ₂ O) - _o CFXCOF (here (X is a fluorine atom or a trifluoromethyl group, and n is 0 or a positive integer) can also be obtained by treating an acid fluoride compound represented by fluorine gas at high temperature ( (See Japanese Patent Application No. 57-46565). In addition, such perfluoroether compounds are commercially available under trademarks such as Garden D-3 (a product of Mondeuson), Fomblin (a product of Montecatini Edison), and PFAZ- or - (a product of Kuriuba). You can also use When using a perfluoropolyether compound as an antifoaming agent, this compound can be added as is to the object to be antifoamed, but generally 1,
Dissolved in a halogen-containing organic solvent such as 1,2-trifluoro-1,2,2-trichloroethane, hexafluoroxylene, hexafluoropropylene oligomer (fluorinated product thereof) to a concentration of approximately 5 to 50%. It is used with This compound can also be used in conjunction with other antifoam materials such as organosilicones, fluorosilicone, ethylene glycol, nonionic surfactants, and the like. The antifoaming agent according to the present invention is particularly excellent in its effect of suppressing foaming caused by organic solvents, particularly organic solvent solutions containing water and oil repellents. Water and oil repellents usually contain about 10 to 75% by weight of vinyl monomers having perfluoroalkyl groups and about 90 to 75% by weight of other vinyl monomers.
25% by weight of the copolymer 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,
It is prepared by dissolving it in 1,2-trichloroethane, fluorocarbons, etc. to a concentration of about 5 to 35% by weight.
An example of such an organic solvent solution containing a water and oil repellent is a dry cleaning solution containing a water and oil repellent, and the foaming that is observed when recovering perchlorethylene etc. from this solution is Effectiveness is prevented by the addition of the antifoaming agent according to the invention. In addition, it is effective for defoaming polyacrylate-based or polyurethane-based paints, silicone-based varnishes, and the like. The antifoaming agent to be added is used in a proportion of about 0.001 to 30% by weight, preferably about 0.01 to 20% by weight, more preferably about 0.1 to 15% by weight, based on the solution of water and oil repellents, paints, varnishes, etc. It will be done. 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 effects of the present invention will be explained with reference to Examples. Note that each reference example describes a method for producing a perfluoropolyether compound used as an active ingredient of an antifoaming agent. Reference example 1 300 ml of 1,1,2-trifluoro-
A 150W ultraviolet lamp housed in a quartz sheath was placed in the longitudinal center of the 1,2,2-trichloroethane solvent, and perfluoroethylene was applied at a flow rate of 60% per hour under the future ultraviolet irradiation.
Oxygen gas is also flowed at a flow rate of 20 per hour. LCD-10
After continuing the reaction at ℃ for 5 hours, the low boiling point fraction was distilled off from the reaction solution, resulting in a ^peroxy group-containing polyether (average molecular weight approximately 2000, 1 40 g of peroxide bond (average of one peroxide bond per molecule) was obtained. (CF ₂ O) − _2.2 (−C ₂ F ₄ O) − _7.3 (−O) _0.5 40 g of the peroxy group-containing polyether thus obtained was placed in the glass reaction vessel, and
A mixed gas of fluorine gas and nitrogen gas (1:2) was flowed therein at a flow rate of 5 per hour for 15 hours at a temperature of 250°C. The product obtained, 29.5 g, has a viscosity of approximately 25 centistokes (40°C), contains no peroxide bonds, and has -
Absorption of CCF was also not observed. Therefore, this product polyether is considered to have the following structure. RO (-CF ₂ O) - _1.0 (-C ₂ F ₄ O) - _2.65 R' [R, R': CF ₃ , C ₂ F ₅ ] Reference Example 2 In Reference Example 1, perfluoroethylene was replaced with perfluoroethylene. Fluoropropylene was used at the same flow rate. A peroxy group-containing polyether (average molecular weight approximately 3200) that is thought to have the following structure is
62g was obtained. (CF ₂ C) − _3.5 (−C ₂ F ₄ O) − _7.2 (−C ₃ F ₆ O) − _10.9 (−
O) _1.0 This peroxy group-containing polyether was treated with a fluorine gas-nitrogen gas (1:2) mixed gas,
When the procedure was carried out in the same manner as in Reference Example 1, 31.5 g of a product having a viscosity of about 30 centistokes (40° C.) was obtained, and this polyether product is thought to have the following structure. RO (−CF ₂ O) − _1.2 (−C ₂ F ₄ O) − _3.08 (−C ₃ F ₆ O) − _4.5
R′ [R, R′: CF ₃ , C ₂ F ₅ , C ₃ F ₇ ] Example 1 1,1,1-trichlor of perfluorooctylethyl acrylate-cyclohexyl acrylate (weight ratio 50:50) copolymer A water and oil repellent made of ethane solution is diluted with perchlorethylene to a concentration of 0.5%, and the antifoaming agent obtained in Reference Example 1 is added in an amount equivalent to 5% of the copolymer in this diluted solution. do. 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 water and oil repellent 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 for each of the above examples are shown in Table 1 below. It will be done. Data for the case where no antifoaming agent is added is also listed there.

[Table] In addition, when using the water and oil repellents of Examples 3 to 5, the solid content of Reference Example 1
Water and oil repellency with and without 0.5% antifoaming agent (measured according to JIS K-1006 3M method, 0 to 100 for water repellency and 0 to 150 for oil repellency) ) was investigated on a 65% cotton/35% polyester twill fabric. As shown in the results in Table 2 below, it can be seen that the water and oil repellency is not affected at all by the use of an antifoaming agent.

[Table] 〃 4 〃 〃 〃 〃
〃 5 〃 〃 〃 〃
Example 6 In Examples 1 to 5, the antifoaming agent obtained in Reference Example 2 was used. The results of the foaming test, expressed in foam height (ml), are shown in Table 3 below.

【table】

Claims (1)

[Claims] 1. The following general formula RO (−CF ₂ O) − _p (−C ₂ F ₄ O) − _q (−C ₃ F ₆ O) − _r R′ (where, R and R' are perfluoroalkyl groups that are the same or different from each other, p, q and r are the number of bonds, and p and r can be 0)
An antifoaming agent containing a perfluoropolyether compound represented by the following as an active ingredient. 2. The antifoaming agent according to claim 1, which is added to an organic solvent-based object to be defoamed. 3. The antifoaming agent according to claim 2, which is added to an organic solvent-based object to be defoamed containing a water and oil repellent.