JPH0347882B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an antifoaming agent that can be used for aqueous foaming, and in particular to an antifoaming agent that exhibits stable antifoaming performance even with temperature changes in aqueous systems with excellent foam suppression and foam breaking properties. be. In various industries, physical or chemical factors such as temperature, pH, and equipment are added to systems that contain substances that cause foaming, which induces foaming, which can lead to problems in manufacturing and product quality, and a decline in production efficiency. This often causes problems. Therefore, in order to solve this problem, it is common practice to add an antifoaming agent to systems that are prone to foaming, either before or after foaming. Conventionally, three types of antifoaming agents have been used: animal and vegetable mineral oil type, silicone type, and polyether polyol type. However, although animal and vegetable mineral oil type antifoaming agents are relatively inexpensive, they are selective in terms of effectiveness and use. In addition, silicone antifoaming agents have excellent antifoaming properties and good antifoaming effects, but they lack sustainability and are relatively expensive.
When used in water-based or emulsion paints, there are drawbacks such as repellency and cratering. On the other hand, polyether polyol type antifoaming agents are characterized by antifoaming properties, but depending on the application, they have poor dispersibility in water, and as a result, the antifoaming agents themselves may aggregate in foaming systems, or may be antifoaming depending on the temperature at which they are used. This may cause operational problems such as uneven performance. The object of the present invention is to provide an antifoaming agent that improves these drawbacks, eliminates troubles caused by foaming, and increases work efficiency.
obtained by polymerizing ethylene oxide and propylene oxide to an active hydrogen-containing compound having
The active ingredient is a reaction product of a polyether polyol compound with an average molecular weight of 2,000 to 15,000 and a glycidyl ether compound with a carbon number of 6 to 22,
Or it relates to an antifoaming agent containing the reaction product. The polyether polyol compound used for producing the active ingredient of the antifoaming agent of the present invention is obtained by adding ethylene oxide and propylene oxide to an active hydrogen-containing compound having 2 to 8 activated hydrogens in a random or block manner. The average molecular weight obtained is from 2,000 to 15,000. In addition, the active hydrogen-containing compound used in the production of this polyether polyol compound contains 2 to 8 active hydrogens, including hydroxyl groups, amino groups, amide groups,
imino group, urea group, mercapto group, thiourea group,
It has a functional group such as a thiocarboxylic acid group or a carboxylic acid group. Examples of active hydrogen-containing compounds having hydroxyl groups include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, nonanediol, decanediol, dipropylene glycol, thioglycol, and 3-hexyne. -2,5-diol, 1,4-butynediol,
Diols such as 1,4-butenediol, neopentyl glycol, 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropionate, dimethylolurea, glycerin, hexanetriol, trimethylol Triols such as ethane, trimethylolpropane, tris (2-hydroxyethyl) isocyanurate, erythritol, pentaerythritol,
Polyols such as pentite, sorbitol, arabite, xyrite, mannitrate, fructose, alkyl glycosides such as ethyl glycoside and propyl glycoside, ethylene glycol glycoside,
Examples include non-reducing sugars of glycol glycosides such as glycerin glycoside and hexanetriol glycoside or derivatives thereof, bisphenols or derivatives thereof, N,N-disubstituted amino alcohols, phosphoric acids such as phosphoric acid, phosphorous acid, and polyphosphoric acid. Examples of those having an amino group include monoalkanolamines such as monoethanolamine, monopropanolamine, and monobutanolamine, benzylamine, aniline, toluidine, naphthylamine, ethylenediamine, trimethyldiamine, tetramethylenediamine, and pentamethylene. Diamines such as diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, and phenylene diamine; triamines such as dimethylene triamine, diethylene triamine, and dipropylene triamine; and dialkanolamines such as diethanolamine, dipropanolamine, and dibutanolamine. Examples include: Although one or a mixture of two or more of these may be used, compounds having a hydroxyl group or an amino group are particularly preferred. Epoxy compounds used in the production of the active ingredient of the antifoaming agent of the present invention include epihalohydrin, styrene oxide, glycidyl compounds, olefin oxide, etc. As the glycidyl compounds, glycidyl ether compounds having 6 to 22 carbon atoms are used. It will be done. Examples of such glycidyl ether compounds include propyl glycidyl ether,
Examples include butyl glycidyl ether, pentyl glycidyl ether, hexyl glycidyl ether, heptyl glycidyl ether, octyl glycidyl ether, nonyl glycidyl ether, decyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, 3-glycidylcypropyltrimethoxysilane, and the like. And these compounds may be used alone or in combination.
More than one type of compound may be used in combination. Such a glycidyl ether compound has the effect of making the terminal hydrophobic by bonding to the terminal hydroxyl group of the polyether polyol compound. The number of moles of the glycidyl ether compound added to the polyether polyol compound is 1 to 100 moles, preferably 2 to 70 moles, per mole of the polyether polyol compound. In addition, the copolymerization ratio of ethylene oxide and propylene oxide and the epoxy compound are adjusted so that the weight percent of ethylene oxide in the compound obtained by reacting the polyether polyol compound with the epoxy compound is 5 to 70%, more preferably 10 to 60%. It is desirable to adjust the number of moles added. If the proportion of ethylene oxide in the total molecular weight is less than 5%, dispersion in aqueous systems will be poor, and if the proportion of ethylene oxide in the total molecular weight is more than 70%, sufficient defoaming performance will not be obtained. . The antifoaming agent of the present invention may be added to the foaming liquid as it is, or may be used as a solution in mineral oil, lower alcohol, etc., or diluted with water. . Furthermore, it may optionally be used in combination with other antifoaming agents. The antifoaming agent of the present invention is suitable for the system to be defoamed.
It is used at a concentration of about 0.001 to 0.1%, but the amount used can be increased or decreased as desired. The antifoaming agent of the present invention has a significantly lower surface tension than conventional antifoaming agents, and has excellent selective orientation toward the gas-liquid interface due to the introduction of appropriate hydrophobic groups.
It has excellent defoaming effects such as foam suppression and foam-breaking properties, and is also unaffected by the temperature and pH of the target system. Examples of the present invention will be shown below and will be explained in more detail. Production example: 76g of propylene glycol is placed in an autoclave that has been replaced with nitrogen gas, and 4g of caustic potassium is charged.
Add and dissolve. And to this, ethylene oxide (hereinafter referred to as "EO")
It is abbreviated as ) 195g (4.4 mol) and heated to 160℃ for 2.5
The reaction was carried out for 3 hours under a pressure of Kg/cm ² , then cooled to 120°C, 1680 g (29 mol) of propylene oxide (hereinafter abbreviated as "PO") was added, and the reaction was carried out for 2 hours to produce a polymer with an average molecular weight of 1950. An ether polyol compound is obtained. Next, 200g of this polyether polyol compound
was charged into a reaction vessel equipped with a stirrer and a cooler that had been replaced with nitrogen gas in advance, and then BF ₃ O was added as a catalyst.
After adding 0.2g of (C ₂ H ₅ ) ₂ and heating to 110°C, 36g of 2-ethylhexyl glycidyl ether was added dropwise.
After continuing the reaction at 110° C. for 4 hours, the mixture was cooled to obtain a compound (reference compound) having a total molecular weight of 2300 and a proportion of ethylene oxide in the molecule of 9%. In the same manner, an epoxy compound was reacted with a polyether polyol compound obtained by addition polymerizing EO and PO to a compound having two or more activated hydrogens, and the resulting compounds were shown in Tables-(A)-1 to 22. Shown below. Further, polyether polyol compounds used for comparison are shown in Tables-(B)-1 to 5.

【table】

[Table] Examples and Comparative Examples The compounds listed in Table 1 and the formulations listed below were added to 200 g of a foaming liquid containing 0.1% dodecylbenzenesulfonic acid triethanolamine salt.
The test liquid containing 0.2% was taken into a cylinder with an inner diameter of 50 mm, passed through a No. 2 differential user stone from the bottom of the cylinder, and aerated at an aeration rate of 150 ml/min. The elapsed time and foaming amount were measured. The results are shown in the table. . In addition, a test solution prepared by adding 0.15% of the compounds of the above examples and comparative examples to 200 g of a foamed aqueous solution containing 4% of polyvinyl alcohol (PVA-217 manufactured by Kuraray Co., Ltd.) was placed in a cylinder with an inner diameter of 50 mm, and a No. Through Deaf User Stone,
Aerate with an airflow rate of 1500ml/min,
The results of measuring the foaming amount after minutes are shown in the table. Blend (C) No. 1 spindle oil (JISK-2210) 50 parts by weight Kerosene No. 1 44 Compound A-1 3 Compound A-5 3 Ethylene bisstearylamide 1 Blend (D) No. 1 spindle oil 50 Parts by weight Kerosene No. 1 44 〃 Compound A-5 3 〃 Compound A-11 3 〃 Ethylene bisstearylamide 1 〃

[Table] Data of the present invention.

[Table] As can be seen from the table and the results of the defoaming test shown in the table, the defoaming agent according to the present invention exhibits extremely superior performance than the conventional polyether polyol type defoaming agent, and is resistant to temperature changes in the foaming system. It shows stable defoaming performance even when

Claims (1)

[Claims] 1 An active hydrogen-containing compound having 2 to 8 active hydrogen groups, obtained by polymerizing ethylene oxide and propylene oxide, with an average molecular weight of 2000 to
1. An antifoaming agent characterized in that the active ingredient is or contains a reaction product of a polyether polyol compound having a carbon number of 15,000 and a glycidyl ether compound having 6 to 22 carbon atoms.