JP3035123B2 - Method for producing light-colored phenol resin emulsion for binding inorganic fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inorganic fiber product obtained by spraying and impregnating a mineral fiber such as rock wool or ceramic fiber or a glass fiber with a phenolic resin, followed by heating and curing, wherein the color is light, The present invention relates to a method for producing a light-colored phenol resin emulsion for binding inorganic fibers, which has excellent characteristics such as moisture resistance, water resistance, abrasion resistance, and mechanical strength.

[0002]

2. Description of the Related Art Conventionally, phenol resins have been used as a binder for binding inorganic fibers. However, phenol is used as a raw material of the phenol resin for binding inorganic fibers, and phenols and aldehydes are used. Catalysts for the addition condensation reaction of compounds include lithium hydroxide, sodium hydroxide, calcium hydroxide, barium hydroxide,
One, two or more selected from basic compounds such as ammonia, triethylamine and triethanolamine, and further, a neutralizing agent after completion of the reaction includes hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, acetic acid, lactic acid, maleic acid, One or more compounds selected from acidic compounds such as paratoluenesulfonic acid are used.

A phenol resin obtained by using phenol as a raw material and various catalysts and neutralizing agents as described above has a hue of yellowish brown to reddish brown, and is sprayed, impregnated and cured by heating. It was unavoidable that the product further turned dark yellowish brown to dark reddish brown. It is considered that the cause of the deep coloration is that the phenol as a raw material is hydrophilic, and the catalyst neutralized salt obtained by neutralizing the catalyst with a neutralizing agent is water-soluble, so that it becomes susceptible to oxidation. .

In addition, since a phenol resin is inevitably colored in a dark color, an amino resin such as a melamine resin is used in place of a light color, especially when a light color is required. However, in this case, since the curing accelerator is added to and mixed with the amino resin, the pot life is short, and it is difficult to reuse the residual resin after use, which not only increases the resin cost but also increases the cost.
The curability is slow, and it has disadvantages such as insufficient properties such as mechanical strength and water resistance in quality. In order to improve these drawbacks, there has been a long-felt need to develop a phenolic resin in which the color of an inorganic fiber product obtained by spraying a resin, impregnating and heating and curing the resin is pale.

[0005]

SUMMARY OF THE INVENTION The method for producing a light-colored phenolic resin emulsion for binding inorganic fibers of the present invention requires improvement while maintaining the properties of conventional phenolic resin emulsions such as curability and mechanical strength. As a result of diligent research aimed at obtaining a phenolic resin with a pale hue of inorganic fiber products after spraying and impregnation heat curing, bisphenol A was used as the raw material phenol, and phenols and aldehydes were added. It was found that a phenolic resin emulsion obtained by a production method comprising using barium hydroxide as a catalyst for the condensation reaction and sulfuric acid as a neutralizing agent for the catalyst was effective, and based on this finding, It has been completed through various studies. Barium sulfate as a catalyst neutralizing salt generated here is suspended and dispersed in the resin, but is insoluble in water or a solvent and has a particle diameter of about 0.5 to 2.0 microns. Turned out not to be. An object of the present invention is to provide a method for producing a phenol resin emulsion in which the hue of an inorganic fiber product after spraying and impregnating and heat-curing is light-colored, which cannot be avoided by a conventional phenol resin emulsion being colored in a dark color. It is in.

[0006]

According to the present invention, bisphenol A comprises phenols (P) and aldehydes (A) comprising 80 to 100 mole percent of all phenols, and the molar ratio A / P is 1.5 to 100%. The barium hydroxide is reacted in the presence of a catalyst consisting of 90 to 100 mole percent of the total catalyst amount, and after the reaction is completed, sulfuric acid is added to 80 to 100 mole percent of the total neutralizer amount. After neutralization with a neutralizing agent consisting of, polyvinyl alcohol is added and mixed as an essential component as an emulsifier, and the pH at 25 ° C.
Is 2.5 to 6.5. Hereinafter, each component used in the present invention will be described.

In the phenols used in the present invention, bisphenol A is 80 to 100 mole percent of the total phenol, but bisphenol having a good color strength after spraying and impregnation and heat curing has good properties such as mechanical strength. The compounding ratio of A is preferably 90 to 100 mole percent, and more preferably 100 mole percent. Here, when bisphenol A is less than 80 mole percent, when the phenol used in combination is phenol, polyhydric phenol, or an alkyl group-substituted phenol having 1 to 3 carbon atoms, the color after spraying and impregnation heat curing is a deep color. In the case of an alkyl group-substituted phenol having 4 or more carbon atoms, the coloration is small, but the curability is deteriorated, and the physical properties such as mechanical strength are reduced. Next, phenols that can be used other than bisphenol A include phenol, catechol,
One or more selected from resorcin, hydroquinone, orthocresol, metacresol, paracresol, ethylphenol, xylenol, propylphenol, butylphenol, octylphenol, nonylphenol, phenylphenol, cumylphenol and the like.

The aldehyde (A) used in the present invention has a molar ratio A / P to the phenol (P) of from 1.5 to 6.0.
However, it is preferably 2.0 to 5.5, and more preferably 3.5 to 4.5. Here, when the molar ratio A / P is less than 1.5, the amount of free phenols contained in the formed phenolic resin increases, and coloring becomes easy after curing. When the molar ratio A / P exceeds 6.0, the amount of free aldehydes contained in the produced phenol resin increases, which is not practically preferable from the viewpoint of working environment and the like. Next, the kind of the aldehyde is one or more selected from formaldehyde, paraformaldehyde, trioxane, acetaldehyde, benzaldehyde and the like.

In the catalyst used in the present invention, barium hydroxide is 90 to 100 mole percent of the total amount of the catalyst. However, from the viewpoint of lightening of the hue after spraying and impregnation and heat curing, the compounding ratio of barium hydroxide is considered. Is preferably 100 mole percent. If the compounding ratio of barium hydroxide is less than 90 mole percent, the color after spraying and impregnation and heat curing becomes dark. Next, as a catalyst that can be used in combination with barium hydroxide, lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, ammonia, triethylamine, one selected from basic compounds such as triethanolamine or Two or more.

The neutralizing agent used in the present invention has a sulfuric acid content of 80 to 100 mol% of the total neutralizing agent amount, but the mixing ratio of sulfuric acid from the viewpoint of lightening of the hue after spraying and impregnation and heat curing. Is preferably 100 mole percent.
If the blending ratio of sulfuric acid is less than 80 mol%, the coloring after spraying and impregnation heat curing tends to be dark. Next, as a neutralizing agent that can be used in combination with sulfuric acid, hydrochloric acid, phosphoric acid, formic acid,
One or more selected from acidic compounds such as acetic acid, lactic acid, maleic acid, and paratoluenesulfonic acid.

The degree of polymerization of polyvinyl alcohol used as an essential component in the present invention is from 300 to 3,000, preferably from 500 to 2,500, more preferably from 1,000 to 2,000. The degree of saponification is from 80 to 98 mol%, preferably from 85 to 95 mol%. If the degree of saponification is less than 80 mol%, a stable emulsion resin having a low emulsifying ability cannot be obtained. When the degree of saponification exceeds 98 mol%, it becomes difficult to emulsify the reaction solution. Further, the polyvinyl alcohol having a single degree of polymerization and a single degree of saponification can be used alone, or a mixture of different degrees of polymerization and different degrees of saponification can be used.

In the present invention, emulsifiers used in combination with polyvinyl alcohol include anionic surfactants, cationic surfactants, nonionic surfactants and amphoteric surfactants, except for the combined use of anionic surfactants and cationic surfactants. One or two or more selected from these may be used. Examples of the anionic activator include alkyl benzene sulfonic acid ester soda, dodecyl benzene sulfonic acid sodium,
Or dialkyl sulfosuccinate soda salt,
Other substances generally known as anionic activators can be used. Examples of the cationic activator include monoalkylamine hydrochloride, dialkylamine hydrochloride, amines having an ester bond, alkyloxazoline, and other substances generally known as cationic activators. As nonionic activators, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene alkyl ester, polyethylene imine, polyhydric alcohol ester,
Other materials commonly known as nonionic activators can be used. Examples of the amphoteric activators include alkali salts of aminosulfuric acid esters, alkylaminoacetates,
Dimethylalkylamides, alkylpolyaminoglycines, and other materials commonly known as amphoteric activators can be used.

The pH of the light-colored phenol resin emulsion for binding inorganic fibers according to the present invention is from 2.5 to 6.5,
Preferably it is 3.5-5.5, More preferably, it is 4.0-5.0. When the pH is higher than 6.5, a large amount of unneutralized basic compounds mainly containing barium hydroxide remains in the phenol resin, and when the pH is lower than 2.5, excess acidic compounds mainly containing sulfuric acid are present. Is present in the resin, the lightening of the hue after spraying and impregnation and heat curing is impaired in any case, and the stability of the emulsion resin is adversely affected. The pH value is a value measured by a glass electrode type pH meter.

The production mode of the light-colored phenolic resin for binding inorganic fibers of the present invention will be described in detail. A phenol (P) and an aldehyde (A) were mixed in a reactor equipped with a stirrer, thermometer and heat exchanger at a molar ratio A / P of 1.5 to 6.0.
Then, a basic compound mainly composed of barium hydroxide is added as a reaction catalyst and reacted at a predetermined temperature for a predetermined time. Thereafter, the mixture is neutralized using an acidic compound mainly containing sulfuric acid as a catalyst neutralizing agent, and polyvinyl alcohol as an emulsifier is added and mixed as an essential component, and the pH at 25 ° C. according to the present invention is 2.5 to 6.5. To obtain a light-colored phenol resin emulsion for binding inorganic fibers.
Barium sulfate as a catalyst neutralized salt obtained here is insoluble in water or a solvent and is a fine particle having a particle diameter of about 0.5 to 2.0 μm, and thus is stabilized by being suspended and dispersed in a resin. In addition, it is also possible to separate and remove phenols, aldehydes, low molecular weight components, and the like by using cold water or hot water as the reaction solution.

[0015]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to the examples.
Note that “parts” and “%” described in the examples and comparative examples all indicate “parts by weight” and “% by weight”.

Example 1 Bisphenol A (P) 2,280 was placed in a reactor equipped with a stirrer, thermometer and heat exchanger.
Parts, 37% formalin (A) 2,030 parts (molar ratio A /
P: 2.5), 50 parts of barium hydroxide and 1.5 parts of sodium dodecylbenzenesulfonate were charged. After gradually heating and raising the temperature until the liquid temperature reaches 80 ° C, react for 2 hours at 80 ± 1 ° C. Then, raise the temperature again and react after reacting at 100 ± 1 ° C for 30 minutes at 100 ± 1 ° C. I let it. Then 20
Neutralized with 71 parts of sulfuric acid, further partially saponified polyvinyl alcohol having a polymerization degree of 1,700 and a saponification degree of 88% (hereinafter, referred to as
670 parts of a 15% aqueous solution of
Was added and mixed to obtain a light-colored phenol resin emulsion for inorganic fiber binding having a pH of 4.8 at 25 ° C.

Example 2 In a reactor of the same type as in Example 1, 1,938 parts (85 mol%) of bisphenol A
And paracresol 162 parts (15 mole percent) and 37% formalin (A) 4,300 parts (molar ratio A / P:
5.3), and 90 parts of 20% sulfuric acid as a neutralizing agent, 550 parts of a 15% aqueous solution of partially saponified PVA having a degree of polymerization of 2,000 and a degree of saponification of 88%, and 1,20 parts of water.
By treating under the same conditions as in Example 1 except that 0 part was used, a light-colored phenol resin emulsion for binding inorganic fibers having a pH of 2.8 at 25 ° C. was obtained.

Example 3 Bisphenol A2, 16 was added to a reactor of the same type as in Example 1.
6 parts (95 mole percent), 47 parts (5 mole percent) phenol and 2,600 37% formalin (A)
Parts (molar ratio A / P: 3.2), and a polymerization degree of 1,70
0, a case of Example 1 except that 667 parts of a 15% aqueous solution of saponified PVA having a saponification degree of 88%, 65 parts of a 15% aqueous solution of a polyacrylamide having a polymerization degree of 1,700, and 1,910 parts of water were used. By processing under the same conditions, 2
A light-colored phenol resin emulsion for inorganic fiber binding having a pH of 5.2 at 5 ° C. was obtained.

Example 4 In a reactor of the same type as in Example 1, 2,280 parts of bisphenol A (P), 1,300 parts of 37% formalin (A) (molar ratio A / P: 1.6), water 47 parts (92 mole percent) of barium oxide and 2.5 parts (8 mole percent) of 20% sodium hydroxide were charged. Gradually heat and raise the temperature until the liquid temperature reaches 75 ° C.
After reacting at 1 ° C. for 3 hours, the temperature was raised again by heating, and after the liquid temperature reached 100 ° C., the reaction was carried out at 100 ± 1 ° C. for 20 minutes.
Then neutralize with 75 parts of 20% sulfuric acid, and further add
0, 500 parts of a 15% aqueous solution of saponified PVA having a saponification degree of 88%, 500 parts of a polymerization degree of 2,400, 200 parts of a 15% aqueous solution of saponified PVA having a saponification degree of 88% and 2,200 parts of water are added and mixed at 25 ° C. A light-colored phenol resin emulsion for binding inorganic fibers having a pH of 4.6 was obtained.

Example 5 In a reactor of the same type as in Example 1, 2,280 parts of bisphenol A (P), 3,400 parts of 37% formalin (A) (molar ratio A / P: 4.2) and water Barium oxide 71 parts (92 mole percent) and purity 7
2.0 parts (8 mole percent) of 5% calcium hydroxide
Was charged. After the temperature was gradually raised by heating and the liquid temperature reached 100 ° C., the reaction was carried out at 100 ± 1 ° C. for 45 minutes, followed by neutralization with 96 parts of 20% sulfuric acid, a polymerization degree of 1,700 and a saponification degree of 8
8 parts of a 15% aqueous solution of saponified PVA (700 parts), gum arabic (25 parts) and water (1,900 parts) were added and dissolved and mixed.
A light-colored phenol resin emulsion for inorganic fiber binding having a pH of 3.8 at 5 ° C. was obtained.

Example 6 In a reactor of the same type as in Example 1, 2,280 parts of bisphenol A (P), 4,500 parts of 37% formalin (A) (molar ratio A / P: 5.6) and water 80 parts of barium oxide is charged, and 2
85 parts (80 mole percent) of 0% sulfuric acid, 5.0 parts (20 mole percent) of maleic acid, and 1,700
A light-colored phenol resin emulsion for inorganic fiber binding having a pH of 6.3 at 25 ° C. was obtained by treating under the same conditions as in Example 1 except that part of the phenol resin was used.

Example 7 In a reactor of the same type as in Example 1, 3,650 parts of 37% formalin (A) (molar ratio A / P:
4.5) using 80 parts of barium hydrate as catalyst and 95 parts (89 mol%) of 20% sulfuric acid and 4.0 parts (11 mol%) of paratoluenesulfonic acid as neutralizing agent, water 1, 25 ° C. by treating under the same conditions as in Example 1 except that 870 parts are used.
A light-colored phenol resin emulsion for inorganic fiber binding having a pH of 5.4 was obtained. The reaction conditions of the light-colored phenolic resin emulsion for binding inorganic fibers obtained in Examples 1 to 7 are summarized in Table 1, and the general characteristics and cured product characteristics are as shown in the upper column of Table 3. .

Comparative Example 1 A reactor of the same type as in Example 1 was charged with 940 parts of phenol, 2,050 parts of 37% formalin, and 50 parts of barium hydroxide. After the temperature was gradually raised by heating and the liquid temperature reached 80 ° C., the reaction was carried out at 80 ± 1 ° C. for 2 hours. Thereafter, the mixture was neutralized with 78 parts of 20% sulfuric acid, and the polymerization degree was 1,7.
800 parts of a 15% aqueous solution of polyacrylamide and 330 parts of water were added and mixed to obtain a resol type phenol resin emulsion having a pH of 5.6 at 25 ° C.

Comparative Example 2 In a reactor of the same type as in Example 1, 1,140 parts (50 mol%) of bisphenol A
And 540 parts (50 mole percent) of paracresol, 3
80 parts of 7% 2,050 and 20% sodium hydroxide were charged. Gradually heat and raise the temperature to 100
After reaching ℃, the reaction was carried out at 100 ± 1 ℃ for 50 minutes. Thereafter, the mixture was neutralized with 120 parts of acetic acid having a purity of 98% to give a polymerization degree of 1,70.
0, 730 parts of a 15% aqueous solution of saponified PVA having a saponification degree of 88% and 1,145 parts of water were added and mixed to obtain a resol type phenol resin emulsion having a pH of 5.8 at 25 ° C.

Comparative Example 3 In a reactor of the same type as in Example 1, 2,280 parts of bisphenol A (P), 1,300 parts of 37% formalin (A) (molar ratio A / P: 1.6) and 2
100 parts of 0% sodium hydroxide were charged. After gradually heating and raising the temperature to 70 ° C. and reacting at 70 ± 1 ° C. for 3 hours, the temperature is again raised and heating to 85 ° C. and reacting at 85 ± 1 ° C. for 1 hour. Was. Then 25% lactic acid 1
The mixture was neutralized with 43 parts, and 800 parts of a 15% aqueous solution of polyacrylamide having a polymerization degree of 1700 and 1,890 parts of water were added and mixed to obtain a resole type phenol resin emulsion having a pH of 6.5 at 25 ° C.

Comparative Example 4 A reaction apparatus of the same type as in Example 1 was charged with 2,030 parts of 37% formalin, 40 parts of calcium hydroxide having a purity of 75% as a catalyst, and 170 parts of 20% sulfuric acid as a neutralizing agent. By treating under the same conditions as in Comparative Example 3 except that 1,640 parts of water was used, a resol type phenol resin emulsion having a pH of 2.5 at 25 ° C. was obtained.

[Comparative Example 5] A comparative example was the same as Example 1 except that 80 parts of barium hydroxide was used as a catalyst, 30 parts of paratoluenesulfonic acid as a neutralizing agent, and 2,330 parts of water. By treating under the same conditions as in the case of No. 3, a resol-type phenol resin emulsion having a pH of 7.3 at 25 ° C. was obtained.

[Comparative Example 6] A comparison was made except that 4,060 parts of 37% formalin was charged into a reactor of the same type as in Example 1, 50 parts of glacial acetic acid was used as a neutralizing agent, and 2,060 parts of water were used. By treating under the same conditions as in Example 5, a resol-type phenol resin emulsion having a pH of 6.0 at 25 ° C. was obtained. Table 2 summarizes the reaction conditions of the resol-type phenolic resin emulsions obtained in Comparative Examples 1 to 6, and general properties and cured product properties are as shown in the lower column of Table 3.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[Method of Measuring General Properties] The method of measuring general properties of each resin obtained in Examples and Comparative Examples will be described. 1. Appearance: Visual. 2. Gel time: 2 ml of resin on a hot plate with a surface temperature of 150 ° C
The time until gelation was measured. 3. Non-volatile content: according to JIS K 6909.

[Method of Measuring Cured Product Characteristics] The method of measuring the cured product characteristics of each resin obtained in Examples and Comparative Examples will be described. 1. Hue: Filter paper (Toyo Roshi Kaisha No. 514A) is impregnated with resin so that the solid resin content is 25 ± 1%.
A resin cured test piece obtained by heating and curing at 0 ° C. for 10 minutes was visually measured. 2. Acetone extraction ratio: A resin is impregnated with a glass fiber so as to have a solid resin content of 30 ± 2% by dipping the glass fiber into the resin.
After drying at 0 ° C., four sheets were piled and cured by heating at 150 ° C. for 30 minutes at a pressing pressure of 50 kg / cm ² to prepare a test piece.
Then, using a Soxhlet extractor, the test piece was subjected to acetone extraction according to a conventional method for 6 hours, and the extraction ratio with respect to the test piece weight was measured (n = 3).

3. Normal bending strength: A resin having a solid resin content of 50 parts is added and kneaded to 1,000 parts of a glass bead base material (diameter: 100 μm), and a mold (dimensions: 10 × 10 ×
(60 mm) so as to have a bulk specific gravity of 1.57 to 1.58, and cured by heating at 230 ° C. for 30 minutes to prepare a test piece. The test piece is a universal tensile tester (span: 50m
m), the bending strength was measured (n = 10). 4. Wet bending strength: The same test piece as the normal bending strength was treated in autoclave boiling water at 110 ° C. for 30 minutes, and then the bending strength was measured (n = 10). 5. Wet bending strength retention: Calculated from (wet bending strength / normal bending strength) × 100.

The light-colored phenol resin emulsion for binding inorganic fibers obtained in Examples 1 to 7 has a much higher hue after spraying and impregnation and heat curing than the resol type phenol resin emulsion obtained in Comparative Examples 1 to 6. Light colored,
In addition, it was confirmed from the normal / wet bending strength that the normal strength and the moisture resistance were excellent, and that the curability was also good from the gelation time and the acetone extraction rate.

[0036]

According to the method for producing a light-colored phenol resin emulsion for binding inorganic fibers of the present invention, many excellent features such as curability of a conventional resol-type phenol resin emulsion are maintained without impairing them. It is possible to industrially produce a phenolic resin emulsion in which the hue of the inorganic fiber product after spraying, impregnating and heat-curing is extremely light. In addition, in conventional resol-type phenol resin emulsions, the hue after heat curing is dark,
Although it was not possible to color a clear hue using a colorant, the use of the phenolic resin emulsion according to the present invention makes it possible to color inorganic fiber products with considerable flexibility because the hue is pale. Becomes possible. For this reason, the light-colored phenol resin emulsion for binding inorganic fibers according to the present invention is used not only in the field where resole type phenol resin emulsions for inorganic fibers are conventionally used, but also in the field where amino resins such as melamine resins are used. Demand is expected to increase.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C08J 3/075 CFB // (C08L 61/12 29:04) (56) References JP-A-53-102359 (JP, A) JP-A-54-57593 (JP, A) JP-A-6-345838 (JP, A) JP-A-49-35491 (JP, A) JP-A-49-40392 (JP, A) JP-A-49-71117 (JP, A) JP-B-46-7171 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 61/04-61/16 C08G 8/00-8/38 C09J 161 / 04-161/16

Claims (1)

(57) [Claims] 1. Bisphenol A contains 8 of all phenols
Phenols (P) consisting of 0 to 100 mole percent
And the aldehyde (A) in a molar ratio A / P of 1.5 to
The barium hydroxide was reacted in the presence of a catalyst consisting of 90 to 100 mole percent of the total catalyst amount, and after the reaction was completed, sulfuric acid was added to 80 to 1 of the total neutralizer amount.
After neutralization with a neutralizing agent consisting of 00 mole percent, polyvinyl alcohol is added and mixed as an essential component as an emulsifier, and the pH at 25 ° C. is 2.5 to 6.5. Of producing a light-colored phenolic resin emulsion for use.