JPH0134089B2 - - 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 oil compositions such as oil compositions or combinations with finely powdered silica etc. Publication No. 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) Alkyl phosphate ester or alkyl phosphite (see Japanese Patent Publication No. 12177-1983)
Examples include. 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 caused by water/hydrocarbon surfactants, they cannot eliminate foam caused by 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 Rf: Lipophobic group (or hydrophobic group) R: Lipophilic group (or hydrophilic group) In particular, dry-clean water and oil repellents made of organic solvent solutions of polyfluorocarbon group-containing copolymers
When organic solvents are used for cleaning, etc., they foam violently when recovered from them, and it is practically impossible to suppress foaming in such systems using commonly used antifoaming agents. It was. 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. The present invention therefore relates to an antifoaming agent, which has the general formula RfCH ₂ CR′XCOO−(RO−) _o COCR′YCH ₂ Rf [] RfCH ₂ CR′XCOO−(RO−) _o COCR '=CHRf [] or RfCH=CR'COO-(RO-) _o COCR'=CHRf [] [Here, R is an alkylene group, R' is a hydrogen atom or a methyl group, and X and Y are hydrogen an atom or an Rf group, where Rf is (CF ₂ O−) _p − (C ₂ F ₄ O−) _q − (C ₃ F ₆ O) _r with one end fluorinated, and n, p , q and r are the number of bonds, r is O
The perfluoropolyether compound represented by the following formula is used as an active ingredient. Such perfluoropolyether compounds are, for example, peroxy group-containing polyethers ( _{CF2- ) s-} ( _C2F4O- ) _t- ( _C3F6O- ) as described in Japanese Patent Publication No. _49-45719 . ) _u − (O) _v [
] and a diacrylate or dimethacrylate of a polyalkylene glycol such as polyethylene glycol or polypropylene glycol in an organic solvent in the presence of a catalyst such as azobisisobutyronitrile as shown in the following formula. . [] + R・(catalyst radical) → (CF ₂ O) _p1 (C ₂ F ₄ O) _q1 (C ₃ F ₆ O) r ₁ +F [(CF ₂ O) _p2 (C ₂ F ₄ O) _q2 (C ₃ F ₆ O) _r2 (C _o F _2o
O〓)〕 (・Abbreviated as Rt, n=1, 2or3) ・Rf＋CH ₂ =CR′COO(RO)nCOCR′=CH ₂ →RfCH ₂ O〓R′COO〜 RfCH ₂ C〓R′COO〜＋・Rf→RfCH ₂ CRfR′COO〜
[A] RfCH ₂ C〓COO〜＋H・→RfCH ₂ CHR′COO〜
[B] RfCH ₂ C〓COO~+H・→RfCH=CRCOO~
[C] [A] - [A], [A] - [B], [B] - [B]: [
] [A]-[C], [B]-[C]: [] [C]-[C]: [] In the Rf group of the obtained perfluoropolyether, the total number of bonds p, q, r is If it is 100,
Generally, p can take a ratio value of 1 to 99, q can take a value of 1 to 70, and r can take a ratio value of 0 to 98, and when r is 0, p and q can each be 1 to 99. When such a perfluoropolyether compound is used as an antifoaming agent, this compound can be added as is to the object to be antifoamed, but generally 1,1,2-trifluoro-1,2,2 -trichloroethane, hexafluoroxylene, 1,
It is used by dissolving it in a halogen-containing organic solvent such as 1,1-trichloroethane, perchlorethylene, trichlorethylene, chloroform, hexafluoropropylene oligomer (its fluorinated product) to a concentration of about 5 to 50%. . 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, lyluene, 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.
Organic solvent solutions containing water and oil repellents include, for example, dry cleaning liquids containing water and oil repellents, and the foaming that occurs when perchlorethylene, etc. is recovered from these liquids is the main problem. This is effectively prevented by adding the antifoaming agent according to the invention. Beyond this, it is effective in 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 1,2,2-trichloroethane solvent was placed in the solvent, and a 150W ultraviolet lamp housed in a quartz sheath was immersed in the longitudinal center of the solvent. Under the future ultraviolet irradiation, perfluoroethylene was applied at a flow rate of 60% per hour.
Oxygen gas is also flowed at a flow rate of 20 per hour. Liquid temperature -10
After continuing the reaction at ℃ for 5 hours, the low boiling point fraction was distilled off after the reaction, and F ¹⁹ NMR revealed that a peroxy group-containing polyether (average molecular weight about 2000, per molecule) was thought to have the following structure. On average, 40 g of 1 peroxide was obtained. (CF ₂ O−) _2.2 −(C ₂ F ₄ O−) _7.3 −(O) _0.5Total of the obtained peroxy group-containing polyethers
200 g and 50 g of polyethylene glycol diacrylate represented by the following formula CH ₂ =CHCOO (CH ₂ CH ₂ O) ₉ COCH = CH ₂ were added, and 1,1,2-trifluoro-
The reaction was carried out under reflux for 4 hours in the presence of 500 ml of 1,2,2-trichloroethane solvent and 0.5 g of azobisisobutyronitrile decomposer, and after the reaction was completed, the solvent was removed under reduced pressure. 219 g of the reaction product was obtained as a viscous yellow-brown liquid, which is believed to have the following structure. RfCH ₂ CHXCOO− (CH ₂ CH ₂ O−) ₉ COCHYCH ₂ Rf RfCH ₂ CHXCOO− (CH ₂ CH ₂ O−) ₉ COCH=CHRf or RfCH=CHCOO− (CH ₂ CH ₂ O−) ₉ COCH=CHRf [ X, Y: H, Rf Rf: One end is fluorinated (CF ₂ O-) ₄ -(C ₂ F ₄ O-) _9.2 ] Reference Example 2 In Reference Example 1, instead of perfluoroethylene Perfluoropropylene was used at a flow rate of 60 per hour. 62g of peroxy group-containing polyether having an average molecular weight of about 3200 was obtained, which is thought to have the following structure. (CF ₂ O−) _3.5 −(C ₂ F ₄ O−) _7.2 −(C ₃ F ₆ O−) _10.9 −(
O) _1.0This peroxy group-containing polyether together
320g, and a reaction with polyethylene glycol diacrylate was carried out in the same manner as in Reference Example 1. The reaction product is a viscous yellow-brown liquid.
265g was obtained, which is thought to have the following structure. RfCH ₂ CHXCOO− (CH ₂ CH ₂ O−) ₉ COCHYCH ₂ Rf RfCH ₂ CHXCOO− (CH ₂ CH ₂ O−) ₉ COCH=CHRf or RfCH=CHCOO− (CH ₂ CH ₂ O−) ₉ COCH=CHRf [ X, Y: H, Rf Rf: One end is fluorinated (CF ₂ O−) _2.2 −(C ₂ F ₄ O−) _4.4 −(C ₃ F ₆ O−) _6.8 ] Example 1 Bar A water and oil repellent consisting of a 1,1,1-trichloroethane solution of a fluorooctylethyl acrylate-cyclohexyl acrylate (weight ratio 50:50) copolymer is diluted with perchlorethylene to a concentration of 0.5%, and the 5% to coweight
A corresponding amount of the antifoaming agent obtained in each reference example 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 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 the table below. .

【table】

【table】

Claims (1)

[Claims] 1 General formula CH ₂ =CR'COO-(RO-) _o COCR'=CH ₂ (where R is an alkylene group, R' is a hydrogen atom or a methyl group, and n is number of bonds)
Di(meth)acrylate of polyalkylene glycol represented by and the general formula (CF ₂ O-) s-(C ₂ F ₄ O-) t-(C ₃ F ₆ O-) u-(O)
v (where s, t, u and v are the number of bonds)
A reaction product with a peroxy group-containing polyether represented by the general formula RfCH ₂ CR′XCOO−(RO−) _o COCR′YCH ₂ Rf RfCH ₂ CR′XCOO−(RO−) _o COCR′=CHRf or RfCH =CR'COO-(RO-) _o COCR'=CHRf (where R, R' and n are the same as defined above, X and Y are hydrogen atoms or Rf groups,
Rf has one end fluorinated (CF ₂ O−) p
-( _C2F4O- )q-( _C3F6O )r, p, q _and r are the corresponding numbers _of bonds below s, t and u, respectively, and r may be O. ) 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.