JP2000313728A - Water-soluble phenol resin for binder of glass fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-soluble phenol resin having excellent curability, hardly causing the hydrolysis of its cured material, mainly useful as a binder resin for glass fibers. SOLUTION: This water-soluble phenol resin is a phenol resin obtained by condensing 1 mol of a phenol component with 2-4 mols of formaldehyde. The phenol component preferably comprises a monohydric phenol and resorcinol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improved water-soluble phenol resin useful mainly as a binder resin for glass fibers.

[0002]

2. Description of the Related Art Glass fibers are hardened with a binder resin in a state of being entangled and formed into a mat shape or the like, and are used in a wide variety of fields as heat insulating materials for buildings and various devices.
Conventionally, the binder resin is a water-soluble phenol resin which is a condensate of monohydric phenol and formaldehyde, from the viewpoint of excellent curability, bonding strength, and water resistance, moisture resistance, flame retardancy, and the like. , Is used a lot. And such a phenolic resin is costly if it is used alone, and since it shows a dark brown color after curing, urea is usually added at the time of its use to achieve bright yellowing and cost reduction. That has been done.

However, in general, when urea is added to a water-soluble phenol resin in a post-addition manner, the curability is inferior to the case where the water-soluble phenol resin is used alone. For this purpose, it is necessary to lengthen the residence time in the heating furnace (reduce the moving speed or lengthen the heating furnace) or raise the heating temperature. In this case, it is inevitable that the productivity of the mat-shaped glass fiber decreases and the production equipment cost becomes expensive.

Further, when the heating temperature is increased, the binder component is decomposed at a high temperature, so that more binder resin is required to obtain glass fiber having strength, and the amount of the decomposed product is required. The need for gas treatment also arises.

When urea is added later, the cured product is liable to undergo hydrolysis. For example, if the cured product is immersed in an aqueous solution of caustic soda, more than 20% of the urea will be decomposed. In such a case, there was also a problem that the bonding force was reduced with time.

[0006]

SUMMARY OF THE INVENTION The present invention is to provide an improved water-soluble phenolic resin which solves the above-mentioned drawbacks of the above-mentioned resin for a glass fiber binder. Another object of the present invention is to provide a water-soluble phenol resin which is sufficiently curable even when urea is added later, and hardly hydrolyzes a cured product, and is mainly useful as a binder resin for glass fibers.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, in particular, a phenol resin was prepared by using resorcinol in addition to monohydric phenols as a phenol component. When it was obtained, it was found that the curing was sufficiently fast even if urea was added later, and that the hydrolysis of the cured product was extremely unlikely, and the present invention was completed.

That is, the present invention relates to a phenol resin obtained by condensing 2 to 4 mol of formaldehyde per mol of a phenol component with an alkali catalyst, wherein the phenol component contains a monohydric phenol and resorcinol. Characteristic, is a water-soluble phenolic resin for glass fiber binder,
The water-soluble phenol resin for a glass fiber binder as described above, wherein the phenol component has a constitutional ratio of 0.1 to 1 mol of resorcinol to 1 mol of the monohydric phenol.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The monohydric phenols referred to in the present invention are compounds having one hydroxyl group on a benzene ring, and specific examples include phenol, cresol, xylenol, and naphthol. But or 2
Even if more than one species are mixed, they can be used. this house,
More preferred are phenol and cresol.

In the present invention, resorcinol is used as a phenol component together with a monohydric phenol. It is appropriate that the amount ratio is in the range of 0.1 to 1 mol of resorcinol to 1 mol of the monohydric phenol. Within this range, the curing speed is in an appropriate range, the hydrolysis of the cured product is small, and the cost is advantageous.

In obtaining the resin of the present invention, the formaldehyde component is contained in a total of 1 mole of the phenol component.
It is desirable that the content be in the range of 2 to 4 moles. In this range, the obtained phenol resin has sufficient strength as a binder even when urea is added later, and the cured product has low hydrolyzability. .

The water-soluble phenolic resin of the present invention is obtained by blending a monohydric phenol, resorcinol and formaldehyde so as to have the composition described above, and condensing the mixture with an alkali catalyst.

Further, it can also be obtained by adding a predetermined amount of resorcinol and formaldehyde to a conventional water-soluble phenol resin produced from monohydric phenol and formaldehyde and reacting with an alkali catalyst.

The formaldehyde used in the present invention includes an aqueous formaldehyde solution (formalin), paraformaldehyde and the like. These can be used alone or in combination. When paraformaldehyde is used alone, water may be appropriately added.

Examples of the alkaline catalyst include hydroxides, oxides or carbonates of alkali metals such as lithium, sodium and potassium, hydroxides or oxides of alkaline earth metals such as magnesium, calcium and barium, ammonia, and the like. Examples thereof include amine compounds such as triethanolamine and triethylamine. These alone,
Alternatively, a mixture of two or more kinds can be used. The amount of the alkali catalyst used is usually adjusted so that the pH of the reaction solution is 8.5 or more, and more preferably, the pH of the reaction solution is 8.5 to 8.5.
It is used in an amount in the range of 10.0.

The condensation temperature is 50 to 50 under normal pressure.
The temperature is in the range of 100 ° C, more preferably 60 to 80 ° C.
The condensation time is suitably in the range of 1 to 10 hours, more preferably 4 to 8 hours.

After the completion of the condensation reaction, p is added with acid for storage stability.
It is preferable to set H to 6 to 9. Examples of the acid used here include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and boric acid, and organic acids such as formic acid, acetic acid, oxalic acid, and maleic acid. These can be used alone or in a mixture.

The water-soluble phenol resin of the present invention can be used as a glass fiber binder as it is, but usually, urea is used in an amount of about 0.5 to 1.5 mol per mol of the phenol component used. Or other additives (aqueous ammonia, ammonium sulfate, a silane coupling agent, a coloring agent, etc.) are added as necessary, and the concentration is adjusted with water before use.

The mat-like glass fibers accumulate the glass fibers blown out from the glass fiber manufacturing apparatus in a flocculent shape on a movable endless belt, and simultaneously or simultaneously with the accumulation, and further prepare the binder resin adjusted as described above. Liquid (usually
(A resin solid content of 9% by weight) is sprayed, and heated and cured at 160 to 250 ° C. for 1 to 30 minutes in a heating furnace for molding.

[0020]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited by these examples. In the following, parts and percentages are by weight unless otherwise specified.

Example 1 In a reaction vessel equipped with a stirrer, a reflux condenser and a thermometer, 94 parts of phenol (hereinafter referred to as P), 22 parts of resorcinol (hereinafter referred to as R) and 40% formaldehyde (hereinafter referred to as F) 270 parts of an aqueous solution
After adjusting the pH to 9.0 with 0% sodium hydroxide, the mixture was stirred at 65 ° C. for 5 hours. Thereafter, the pH was adjusted to 7.5 with hydrochloric acid, and the mixture was cooled to obtain a water-soluble phenol resin. The R / P molar ratio (A) of this resin was 0.2, and the F / (P + R) molar ratio (B) was 3.0. The water-soluble phenol resin had a non-volatile content at 105 ° C. for 3 hours of 45.0%.

After adding 20 parts of urea to 100 parts of the obtained water-soluble phenol resin and mixing well, weigh 5 g of each in an aluminum foil dish and place in an oven set at 160 ° C.
Heat cured. After 10 minutes, the cured product was taken out every 5 minutes and allowed to cool to room temperature. This cured product is pulverized for 1 minute with a pulverizer (vibrating pulverizer manufactured by Yoshida Seisakusho), and sieved with a sieve.
A cured product powder of 48 to 100 mesh was obtained. 1.5 g (R0) of this cured product powder was placed in a 200 ml Erlenmeyer flask, and 70 ml of a 1N aqueous sodium hydroxide solution was added thereto.
For 20 hours with a shaker. Then, after centrifuging with a centrifuge (15000 rpm) and discarding the supernatant,
After adding water and neutralizing with acetic acid, the mixture was centrifuged again to remove the supernatant. The residue is washed successively with water and methanol,
After drying at room temperature for 3 hours and cooling to room temperature, it was weighed (R
1). Hydrolysis rate (%) from R0 and R1 according to the following formula 1.
I asked.

Formula 1: Hydrolysis rate (%) = [(R0−R1) / R0] × 100

Table 1 shows the composition of the resin and the hydrolysis rate calculated by the above equation.

Examples 2 to 4 and Comparative Examples 1 to 3 A water-soluble phenol resin was obtained in the same manner as in Example 1 except that the amounts of phenol, resorcinol and 40% formaldehyde were changed as shown in Table 1. Example 1
In the same manner as in the above, the performance of the obtained water-soluble phenol resin was examined. The results are shown in Table 1.

[0025]

[Table 1]

[0026]

As is clear from the above description, particularly from Table 1 in the Examples, the water-soluble phenol resin for a glass fiber binder of the present invention has a high curing rate even when urea is added, and has a high hydrolysis rate. Is also less likely to occur, and is extremely satisfactory for use in the production of mat-like glass fibers. That is, according to the present invention, there is provided a water-soluble phenol resin for a glass fiber binder, which has better curing speed and hydrolysis resistance than a conventional water-soluble phenol resin for a glass fiber binder comprising monohydric phenol and formaldehyde. Was done.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takayuki Ishikawa 1 Toonuma-cho, Sunagawa-shi, Hokkaido Mitsui Chemicals Co., Ltd. F-term (reference) 4J033 CA02 CA03 CA11 CA12 CA13 CA22 CA29 CB02 CC02 CC04 CC07 HA08 HB02

Claims (2)

[Claims] 1. A phenol resin obtained by condensing 2 to 4 mol of formaldehyde per 1 mol of a phenol component with an alkali catalyst, wherein the phenol component contains a monohydric phenol and resorcinol. Water-soluble phenol resin for glass fiber binder. 2. The water-soluble phenol resin for a glass fiber binder according to claim 1, wherein the phenol component has a composition ratio of 0.1 to 1 mol of resorcinol per 1 mol of the monohydric phenol.