JPH11199291A - Defoaming agent, building material board and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyether defoaming agent having an excellent defoaming effect even when a small amt. of the agent is used by adding ethylene oxide to a higher alcohol, further adding an alkylene oxide other than ethylene oxide and imparting a specified clouding point thereto. SOLUTION: An alcohol and an alkali metallic hydroxide as a catalyst are charged into an agitation type autoclave, melted by heating and dehydrated under reduced pressure. Ethylene oxide is charged and brought into addition reaction under elevated temp. and pressure. Propylene oxide and/or butylene oxide is then charged and brought into addition reaction under elevated temp. and pressure. The catalyst is removed from the reaction product and a compd. of the formula [where R is an 8-28C alkyl or alkenyl; A is a 3-4C alkylene; (m) is 3-10; (n) is 5-40; and 8<=m+n<=50] having 25-95 deg.C clouding point measured by the butyl diglycol method is obtd. This compd. is used as an essential component to obtain the objective defoaming agent. In a process for making a building material board, 25-500 ppm of the defoaming agent based on the solid content is used. Productivity is increased and the quality of the product can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an antifoaming agent.
More specifically, it relates to defoaming agents useful in the processing steps of the pulp and paper industry, the food industry, the petroleum industry, the chemical industry, the textile industry, the paint industry, the waste treatment, etc., and the wastewater treatment process, in addition to the papermaking process for building material boards. It is.

[0002]

2. Description of the Related Art Polyether-based defoamers have various excellent properties as compared with other types of defoamers. Therefore, besides the process of building board, paper pulp industry, food industry, petroleum industry,
It is widely used in the chemical industry, textile industry, paint industry, processing processes such as waste treatment, and wastewater treatment processes that involve foaming.

As a polyether-based antifoaming agent, those obtained by adding propylene oxide to a higher alcohol and then adding ethylene oxide (JP-B-53-13478).
No. 5) is known. However, this type of polyether-based defoamer is not sufficiently satisfactory in defoaming effect.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyether-based antifoaming agent having an excellent defoaming effect even when used in a small amount. The present inventors have conducted intensive studies, and as a result, completed the present invention by adding a specific alkylene oxide other than ethylene oxide after adding ethylene oxide to a higher alcohol and giving a specific cloud point. Was.

[0005]

Means for Solving the Problems That is, the present invention is the cloud point by butyl diglycol method is 25 to 95 ° C. the following general formula _{R-O (C 2 H 4} O) m (AO) n -H ------------------ (1) (wherein, R is a linear or branched alkyl or alkenyl group having 8 to 28 carbon atoms, and A is 3 carbon atoms) -4 alkylene groups, m is a real number of 3-10, n is a real number of 5-40, m + n
Indicates a real number of 8 to 50. The present invention also provides a defoaming agent characterized by containing the compound represented by the formula (1) as an essential component, a building material board using the compound in a papermaking process, and a method for producing the board.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION R is a linear or branched alkyl or alkenyl group having 8 to 28 carbon atoms, and represents a reaction residue of an alcohol. Examples of the alcohol having 8 to 28 carbon atoms include natural alcohols and / or synthetic alcohols.
Species or two or more can be used. Natural alcohols include saturated alcohols such as octanol, decanol,
Dodecanol, tetradecanol, hexadecanol,
Octadecanol, eicosanol, docosanol, tetracosanol, hexacosanol, octacosanol and the like can be mentioned. Examples of the unsaturated alcohol include oleyl alcohol. Examples of the synthetic alcohol include 2-ethylhexanol. Aerial oxidation of straight-chain, unbranched saturated alcohols synthesized by the Ziegler method, straight-chain primary alcohols or branched primary alcohols synthesized by the oxo method, or mixtures of these alcohols having different carbon numbers or paraffins Straight-chain secondary alcohols to be produced;

R has a carbon number of 8 to 28, preferably a linear or branched alkyl or alkenyl group, preferably 12 to 28 carbon atoms.
24 linear or branched alkyl groups or alkenyl groups, more preferably 14 to 22 linear alkyl groups. When the carbon number of R is less than 8, there is a disadvantage that the defoaming property is inferior. On the other hand, if it exceeds 26, solids precipitate out during storage of the manufactured product, making it difficult to handle.

A is an alkylene group having 3 to 4 carbon atoms, and represents a propylene group and / or a butylene group.

M is 3 to 10, preferably 4 to 9, and more preferably 5 to 8. If m is less than 3, the dispersibility in water is reduced and it is difficult to handle, which is not preferred. On the other hand, when it exceeds 10, it is not preferable because it is easily dissolved in water and the defoaming property is lowered.

N is 5 to 40, preferably 7 to 30, and more preferably 10 to 25. When n is less than 5, the manufactured product is easily dissolved in water, and the defoaming property is undesirably reduced. On the other hand, if it exceeds 40, the defoaming property is undesirably reduced.

M + n is from 8 to 50, preferably from 11 to
9, more preferably 15 to 33.

The cloud point by the butyldiglycol method is 25 to
95 ° C, preferably 30 to 80 ° C, more preferably 3 ° C
5 to 70 ° C. If the cloud point is less than 25, it is difficult to disperse in water, and the defoaming property is undesirably reduced. On the other hand, if it exceeds 95, it is not preferable because it is easily dissolved in water and the defoaming property is reduced. The cloud point by the butyldiglycol method is measured by preparing a 1% solution of an antifoaming agent using a 25% by weight aqueous butyldiglycol solution as a solvent.

The antifoaming agent of the present invention can be used for foaming in the papermaking process of building material boards, processing processes such as paper pulp industry, food industry, petroleum industry, chemical industry, textile industry, paint industry, waste treatment, and wastewater treatment. It can be used in related industries.

In particular, an excellent defoaming effect can be exhibited when used in a small amount for the purpose of removing bubbles which hinder production without reducing productivity and water resistance when used in the papermaking process of building material board production. The papermaking process of building material board includes the exterior building material board, asbestos / cement board, asbestos / cement board, calcium silicate board, inorganic building board such as tile, and organic building board such as tatami board, etc. No.
As a method for producing an inorganic building material board produced using the defoamer of the present invention, cement, calcium silicate, silica, inorganic powder such as calcium carbonate and fiber reinforcing material such as bleached pulp, unbleached pulp, waste paper, etc. A slurry obtained by mixing and stirring pulp, synthetic fiber, asbestos, and water is formed by a papermaking drum, filtered, dewatered to a cake, dried and cured to produce a board. As a method for producing an organic building material board produced using the defoamer of the present invention, the above-mentioned pulp or synthetic fiber and an organic binder such as phenol resin, methyl cellulose, PVA, ethylene / vinyl acetate copolymer, polyethylene A slurry obtained by mixing and stirring an inorganic powder such as oxide, calcium silicate, silica, calcium carbonate, and water with a papermaking drum is formed, filtered, dehydrated into a cake, dried and cured to produce a board. As a papermaking method used in the production, a round mesh papermaking method,
Fourdrind papermaking method and the like are mentioned. Examples of the curing method include a natural curing method, a steam curing method, and an autoclave curing method. Since the drainage rate is improved by adding the present antifoaming agent, productivity can be increased. Further, the building material board manufactured by using the defoaming agent of the present invention has a feature that the reduction in water resistance is small, and the quality of the product can be improved.

The tatami board papermaking step is a step of manufacturing a tatami board by papermaking, and is used during slurrying and for suppressing filtrate foaming.

In the pulp and paper industry, cooking, washing and wastewater treatment processes in kraft pulp production, bleaching and wastewater treatment processes in DIP production, papermaking and wastewater treatment processes in papermaking, coating in coated paper production Examples include a color creation process, a coating process, a wastewater treatment process, and a manufacturing process of paperboard, information paper, packaging paper, and the like. Also,
Used for starch size liquids used in paper manufacturing.

In the food industry, a fermentation step, an enzyme extraction step,
Examples include a tofu production process and an antibiotic production.

In the petroleum industry, a process for producing a lubricating oil, a fuel oil, an aqueous hydraulic fluid, a cutting oil, and the like can be mentioned. For example, it is used to prevent foaming in the desulfurization step of crude oil and to suppress foaming by blending it with an aqueous hydraulic fluid.

In the chemical industry, synthetic rubber and latex industry, polymer industry, ink industry, ceramic industry, cement and gypsum industry, adhesives and adhesives industry, wet phosphoric acid production, storage battery industry, photographic film industry, detergent and cleaner industries, etc. Is mentioned. In the synthetic rubber and latex industries, it is used at the time of emulsion polymerization during the production of SBR, NBR, PVC, etc., at the time of recovering unreacted monomers, and at the time of preparing products. In the polymer industry, it is used when producing natural and synthetic water-soluble polymers, ie, PVA, starch, gelatin, acrylic resins, etc., and emulsion synthetic resins and when preparing aqueous solutions. In the ink industry, it is used in ink production and in printing processes such as screen printing. In the ceramics industry, it is used when slurrying using a binder such as PVA, CMC, or acrylic resin and an inorganic substance. In the cement and gypsum industries, they are used in the form of slurry or blended with inorganic powder like self-leveling flooring. Used in the adhesive and adhesive industries to suppress foaming when emulsifying synthetic and natural resins such as acrylic, acrylic styrene, rosin, and hydrogenated rosin, and when applying to labels and films. . In wet phosphoric acid production, it is used at the time of acid decomposition of neighboring ores.

The textile industry includes a dyeing step, a refining step, a sizing step, a finishing step, and the like, and is used particularly in a production step by jet dyeing, high-speed spinning, and high-temperature dyeing.

In the paint industry, there are water-based paints, non-aqueous paints and the like. Water-based paints are used for vinyl emulsion paints such as acrylic emulsion paints and vinyl acetate resin paints, water-dispersed epoxy paints, aminoalkyd resin paints, aminoacrylic resin paints, melamine resin paints, and water-soluble resin paints. Further, as a use, it can be used as a building paint, a building material paint, an elastic paint, a gloss paint, a lysine paint, and the like. Non-aqueous paints include dry acrylic paints,
Acrylic / urethane paint, epoxy paint, alkyd
Used in melamine paints, polyester urethane resin paints, polyester melamine resin paints. Applications include cationic electrodeposition coatings, powder coatings, can coatings, coil coatings, and the like.

The waste treatment process includes sewage treatment, human waste treatment, livestock manure treatment, sewage purification, waste liquid treatment in the treatment process of incineration residue of combustible waste, and the like, and is used to increase treatment efficiency. .

In the wastewater treatment step, food industry wastewater such as meat processing wastewater, chemical factory wastewater such as catalyst and emulsifier removal washing step after production of synthetic rubber, petroleum industry wastewater, textile industry wastewater, paint industry wastewater, and wastewater treatment wastewater Can be used for drainage.

The antifoaming agent of the present invention is generally used in an amount of 0.1 to 50,
000 ppm, preferably in the range of 1 to 5,000 ppm. In the papermaking process for building material boards, an antifoaming agent is added in a range of 25 to 500 ppm based on the solid content. The solid content indicates the content of all components other than water in the slurry prepared in the papermaking process.

In the addition reaction of ethylene oxide (hereinafter abbreviated as EO) and propylene oxide (hereinafter abbreviated as PO) or / and butylene oxide (hereinafter abbreviated as BO) of the antifoaming agent of the present invention, EO was added to alcohol. rear,
It is produced by adding PO and / or BO. In the case of adding PO or / and BO to alcohol and then adding EO, a sufficient defoaming effect cannot be obtained in the building material board papermaking process.

As a method for producing the defoaming agent of the present invention, an alcohol and a hydroxide of an alkali metal as a catalyst, for example, potassium hydroxide are charged into a stirring autoclave, and the system is purged with nitrogen at 100 to 180 ° C. To dissolve,
Dehydration is performed under reduced pressure of 0 to 100 mmHg to remove water in alcohol. Next, EO is charged and 1 to 10 kg / cm
^After reacting at a reaction temperature of 100 to 180 ° C. for 1 to 24 hours under a pressure of ² G to add EO, PO or / and BO
And reacted at a reaction temperature of 70 to 150 ° C. for 1 to 24 hours under a pressure of 1 to 10 kg / cm ² G. Powders such as magnesium silicate, aluminum silicate, hydrotalcites, etc. are added to the product, and the catalyst is removed by an adsorption reaction treatment.

The method of using the antifoaming composition of the present invention may be any of continuous addition, intermittent addition, or a method in which a foam measuring device and an antifoaming agent adding device are linked, and may be added at one place or at multiple points. Either may be used. Upon addition, the mixture may be diluted with a suitable solvent or water, or may be used in combination with another antifoaming agent.

[0028]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

Examples 1 to 10: The polyether defoamers of Examples 1 to 10 are shown in Table 1.

Comparative Examples 1 to 11: The polyether antifoaming agents of Comparative Examples 1 to 11 are shown in Table 1.

Test Example 1: Using the defoaming agents of Examples 1 to 10 and Comparative Examples 1 to 11, a defoaming test was performed in an asbestos / cement board making process. (Test method) Defoaming property for slurry: Asbestos / cement board paper making process 93 parts of white water, 6 parts of Portland cement, 0.7 parts of used paper,
A slurry is prepared by mixing 0.3 parts of asbestos. Slurry 1
00 g was placed in a glass measuring cylinder having an inner diameter of 50 mm and a height of 350 mm, and 10 ppm of an antifoaming agent was added.
After adjusting the temperature, a diffuser stone is placed at the bottom of the liquid, and air is ventilated at 4000 ml / min. Measure the foam volume after 3 minutes. Defoaming property against white water: Asbestos / cement board paper making process White water 1
00 g was placed in a glass measuring cylinder having an inner diameter of 50 mm and a height of 350 mm, 5 ppm of an antifoaming agent was added, and after adjusting the temperature to 25 ° C, a diffuser stone was placed at the bottom of the liquid.
Vent at 000 ml / min. Measure the foam volume after 10 minutes. (Test results) The test results are shown in [Table 2]. Examples 1 to 1
The defoaming agent of No. 0 showed superior defoaming performance as compared with the defoaming agents of Comparative Examples 1 to 11.

Test Example 2: Using the defoaming agents of Examples 1 to 10 and the defoaming agents of Comparative Examples 1 to 11, a defoaming test was performed in an asbestos-free and cement board forming process. (Test method) Defoaming property to slurry: Asbestos / cement board paper making process 93 parts of white water, 6 parts of Portland cement and 1 part of waste paper are mixed to prepare a slurry. 100 g of slurry with an inner diameter of 50
mm × 350 mm height glass graduated cylinder, 10 ppm of antifoaming agent was added, and after adjusting the temperature to 25 ° C., diffuser stone was added to the liquid bottom and air was 4000 ml /
Vent in minutes. Measure the foam volume after 3 minutes. Defoaming property against white water: Asbestos-free and cement board making process 100 g of white water is put into a glass measuring cylinder having an inner diameter of 50 mm and a height of 350 mm, and 5 ppm of an antifoaming agent is added thereto.
After adjusting the temperature, a diffuser stone is placed at the bottom of the liquid, and air is ventilated at 4000 ml / min. Measure the foam volume after 10 minutes. (Test results) The test results are shown in [Table 3]. Examples 1 to 1
The defoaming agent of No. 0 showed superior defoaming performance as compared with the defoaming agents of Comparative Examples 1 to 11.

Test Example 3: Using the defoaming agents of Examples 1 to 5 and Comparative Examples 1 to 5, a defoaming test was carried out in a calcium silicate plate forming process. (Test method) Defoaming property to slurry: Calcium silicate plate paper making process 94.7 parts of white water, 5 parts of calcium silicate, and 0.3 parts of waste paper are mixed to prepare a slurry. 100 g of slurry with an inner diameter of 50
mm × 350 mm height glass-made measuring cylinder, 15 ppm of an antifoaming agent was added, and after adjusting the temperature to 25 ° C., a diffuser stone was put in the liquid bottom and air was 4000 ml /
Vent in minutes. Measure the foam volume after 3 minutes. Antifoaming property against white water: Calcium silicate plate paper making process White water 1
00 g was placed in a glass measuring cylinder having an inner diameter of 50 mm and a height of 350 mm, 5 ppm of an antifoaming agent was added, and after adjusting the temperature to 25 ° C, a diffuser stone was placed at the bottom of the liquid.
Vent at 000 ml / min. Measure the foam volume after 10 minutes. (Test results) The test results are shown in [Table 4]. Examples 1 to 5
The defoamer of No. 1 showed excellent defoaming performance as compared with the defoamers of Comparative Examples 1 to 5.

Test Example 4: Using the defoaming agents of Examples 1 to 5 and Comparative Examples 1 to 5, a defoaming test was performed in the tile making process. (Test method) Defoaming property to slurry: roof paper making process 94.7 parts of white water,
A slurry is prepared by mixing 7 parts of Portland cement and 0.4 part of waste paper. 100 g of the slurry is placed in a glass measuring cylinder having an inner diameter of 50 mm and a height of 350 mm, and 7 ppm of an antifoaming agent is added. After adjusting the temperature to 25 ° C., a diffuser stone is placed at the bottom of the liquid, and air is ventilated at 4000 ml / min. Measure the foam volume after 3 minutes. Defoaming property against white water: tile making process 100 g of white water with an inner diameter of 5
It is placed in a 0 mm × 350 mm height glass measuring cylinder, 5 ppm of an antifoaming agent is added, and after adjusting the temperature to 25 ° C., a diffuser stone is placed at the bottom of the liquid, and air is ventilated at 4000 ml / min. Measure the foam volume after 10 minutes. (Test results) The test results are shown in [Table 5]. Examples 1 to 5
The defoamer of No. 1 showed excellent defoaming performance as compared with the defoamers of Comparative Examples 1 to 5.

Test Example 5 Using the defoaming agents of Examples 1 to 5 and Comparative Examples 1 to 5, a defoaming test in a tatami board papermaking process was performed. (Test method) Tatami mat paper making process 100 g of white water with an inner diameter of 50
mm × 350 mm height glass measuring cylinder, 20 ppm of antifoaming agent was added, and after adjusting the temperature to 25 ° C., diffuser stone was put in the liquid bottom and air was 2,000 ml /
Vent in minutes. Measure the foam volume after 10 minutes. (Test results) The test results are shown in [Table 6]. Examples 1 to 5
The defoamer of No. 1 showed excellent defoaming performance as compared with the defoamers of Comparative Examples 1 to 5.

Test Example 6: The defoaming test in the kraft pulp washing step was performed using the defoaming agents of Examples 1 to 5 and Comparative Examples 1 to 5. (Test method) Defoaming property for kraft pulp washing process water: 500 ml of kraft pulp washing process water was put into a glass foam tube, and 3
While maintaining the temperature at 5 ° C. and using a circulating pump to remove the foam from the bottom of the foam tube at a flow rate of 2000 ml / min, the foam is dropped from the upper portion of the foam tube to the process water surface to foam. Defoamer 3ppm when foam height reaches 100mm by process water circulation
Is added, and the minimum foam height after the addition of the defoaming agent, its arrival time, and the foam height after 5 minutes are measured. (Test results) The test results are shown in [Table 7]. Examples 1 to 5
The defoamer of No. 1 showed excellent defoaming performance as compared with the defoamers of Comparative Examples 1 to 5.

Test Example 7 Using the defoaming agents of Examples 1 to 5 and Comparative Examples 1 to 5, a defoaming test was performed in white water for a papermaking process. (Test method) Defoaming property against white water for papermaking process: 500 ml of high quality papermaking white water was put into a glass foam tube, kept at 35 ° C, and withdrawn from the bottom of the foam tube at a flow rate of 2000 ml / min using a circulation pump. It is foamed by dropping it from the upper part of the foaming tube to the process water surface. Foam height is 100 by circulation of process water
mm is reached, 3 ppm of an antifoaming agent is added, and the minimum foam height after addition of the antifoaming agent, its arrival time, and the foam height after 5 minutes are measured. (Test results) The test results are shown in [Table 8]. Examples 1 to 5
The defoamer of No. 1 showed excellent defoaming performance as compared with the defoamers of Comparative Examples 1 to 5.

Test Example 8 Using the defoaming agents of Examples 1 to 5 and Comparative Examples 1 to 5, a defoaming test was performed in the human waste treatment step. (Test method) Defoaming property for human waste treatment process water: human waste treatment process water 100
g was placed in a glass measuring cylinder having an inner diameter of 50 mm and a height of 350 mm, and 50 ppm of an antifoaming agent was added.
Vent at 00 ml / min. The foam height after 10 minutes is measured. (Test results) The test results are shown in [Table 9]. Examples 1 to 5
The defoamer of No. 1 showed excellent defoaming performance as compared with the defoamers of Comparative Examples 1 to 5.

Test Example 9 Using the defoaming agents of Examples 1 to 5 and the defoaming agents of Comparative Examples 1 to 5, a defoaming test in a papermaking wastewater treatment step was performed. (Test method) Defoaming property for papermaking wastewater: 100% papermaking wastewater
g was placed in a glass measuring cylinder having an inner diameter of 50 mm and a height of 350 mm, and 2 ppm of an antifoaming agent was added.
Vent at 0 ml / min. Measure the foam volume after 5 minutes. (Test results) The test results are shown in [Table 10]. Example 1
The antifoaming agent of No. 5 showed superior defoaming performance as compared with the antifoaming agents of Comparative Examples 1 to 5.

Test Example 10 A drainage test was conducted using the defoaming agents of Examples 1 to 5 and Comparative Examples 1 to 5. (Test method) Freeness of asbestos / cement board: A slurry composed of 100 parts of Portland cement, 6 parts of NUKP pulp and 3 parts of asbestos is prepared. Water and the solid content are stirred and mixed with a mixer so that the solid content concentration becomes 7% by weight. After adding an antifoaming agent to 500 g of the prepared slurry and stirring the mixture for 10 seconds with a mixer, the slurry is put into a drainage tester and the filtration time (second) is measured. Filtration was performed by filtering through a 60-mesh wire with a vacuum pressure of 50 mmHg, a slurry temperature of 25 ° C. The end point of the filtration is the point at which there is no water layer on the surface of the filtered solids. The drainage is better as the filtration time is shorter. (Test results) The test results are shown in [Table 11]. Example 1
The antifoaming agent of No. 5 showed excellent drainage as compared with the antifoaming agents of Comparative Examples 1 to 5.

Test Example 11 Using the defoaming agents of Examples 1 to 5 and Comparative Examples 1 to 5, asbestos / cement boards were prepared and subjected to a water resistance test. (Test method) Water resistance to asbestos / cement board: The water-containing board prepared by filtration in Test Example 10 is placed in a constant-temperature bath at 90 ° C capable of generating saturated steam and left for 48 hours to form a hardened board. The weight (W1) is measured after leaving this board in a constant temperature and humidity room at 25 ° C. and a humidity of 40% for 8 hours. next,
After immersing in a 25 ° C constant temperature water bath for 8 hours,
After standing for a time, the weight (W2) is measured. The water content is calculated by the following equation. The board water resistance is better as the moisture content is lower. Water content (%) = [(W2−W1) / W1] × 100 (Test results) The test results are shown in [Table 12]. Example 1
The antifoaming agent of No. 5 showed superior board water resistance as compared with the antifoaming agents of Comparative Examples 1 to 5.

R in Table 1 represents the reactive residue of the alcohol used and the number of carbon atoms. The cloud point by the butyldiglycol method was measured by using a 25% by weight aqueous butyldiglycol solution as a solvent and preparing a 1% solution of an antifoaming agent.

The defoaming performance in Tables 2 to 10 was ranked according to the following criteria. Evaluation criteria A: ◎; less than 100, ；: 100 to 200,
Δ; 200 to 300, ×; 300 or more (1 to 10 minutes), XX; 300 or more (within 1 minute) Evaluation criteria B: ；; less than 5, ；: 5 to 20, △; 10 to 2
0, XX; 20-100, XX; 100 or more Evaluation C: ◎; less than 10, ；: 10-20, Δ; 20
30 to 60; Evaluation criteria D: 評 価; less than 30;
○; 30 to 50, Δ; 50 to 70, ×; 70 to 100,
Xx; 100 or more

The drainage in Table 11 was ranked according to the following criteria. Evaluation criteria E: ○; 15 to 30, Δ; 31 to 40, ×; 4
1 to 50, xx; 51 or more

The water resistance in Table 12 was ranked according to the following criteria. Evaluation criteria F: ○; 10 to 30, Δ; 31 to 40, ×;
1-60

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

[Table 3]

[0049]

[Table 4]

[0050]

[Table 5]

[0051]

[Table 6]

[0052]

[Table 7]

[0053]

[Table 8]

[0054]

[Table 9]

[0055]

[Table 10]

[0056]

[Table 11]

[0057]

[Table 12]

[0058]

The defoaming agent of the present invention exhibits an excellent defoaming effect even when used in a small amount, and thus has an advantage that foam control can be easily performed. Further, the building material board using the antifoaming agent of the present invention has little merit of reduction in water resistance, has good merit of drainage in the production process, and has an advantage of increasing the productivity and quality of the board, and is very useful in practice.

[Procedure amendment]

[Submission date] February 25, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

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[Table 5]

[Procedure amendment 2]

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[Table 6]

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[Table 7]

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[0053]

[Table 8]

[Procedure amendment 5]

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[Table 9]

[Procedure amendment 6]

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[0055]

[Table 10]

[Procedure amendment 7]

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[Table 11]

[Procedure amendment 8]

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[Table 12]

Claims (6)

[Claims] (1) a cloud point of 25 to 25 according to a butyldiglycol method;
The following general formula at 95 ° C .: RO (C ₂ H ₄ O) _m (AO) _n -H (1) R is a linear or branched alkyl or alkenyl group having 8 to 28 carbon atoms, A is an alkylene group having 3 to 4 carbon atoms, m is a real number of 3 to 10, n is a real number of 5 to 40, and m + n
Indicates a real number of 8 to 50. An antifoaming agent comprising a compound represented by the formula (1) as an essential component. 2. m is 5 to 8, n is 10 to 25, and m + n is 1.
5 to 33, cloud point 35 to 7 by butyl diglycol method
The antifoaming agent according to claim 1, which is at 0 ° C. 3. The antifoaming agent according to claim 1, wherein R has 14 to 22 carbon atoms. 4. An antifoaming agent for a building material board papermaking process, comprising the compound according to claim 1 as an essential component. 5. A building material board which is manufactured by papermaking using the compound according to claim 1 as an essential component of an antifoaming agent. 6. The antifoaming agent according to any one of claims 1 to 3, wherein the content of the defoamer is 25 to 500 pp with respect to the solid content in the papermaking process of the building material board.
m. A method for manufacturing a building material board, wherein the method is used in a range of m.