JPH11269449A - Binder composition for glass wool or rock wool heat insulation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder which can perfectly cure in a low-temperature region and requires a small quantity of heat when it is cured by incorporating a cure accelerator being sodium carbonate in a water-soluble phenolic resin containing and urea. SOLUTION: There is provided a binder composition prepared by adding 0.5-5 pts.wt. sodium carbonate as a cure accelerator to 100 pts.wt. solid matter of a urea-modified phenolic resin premix solution prepared by mixing a water-soluble phenolic resin with urea in a solid matter ratio of 50/50 to 100/1, and subjecting the mixture to a premix reaction at 25-40 deg.C for a specified time. A specified amount of this composition is sprayed onto a glass wool or rock wool heat insulation material, and the assemblage is cured by heating at 200-220 deg.C with e.g. hot press. The water-soluble phenolic resin is produced by mixing 1 mol of phenol with 1-5 mol of formaldehyde, adjusting the reaction system to a pH of 7.5-12.0 by the addition of a basic catalyst, and reacting the reaction system at 50-100 deg.C for a specified time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binder for a heat insulating material, and more particularly to a binder composition for a glass wool or a rock wool heat insulating material which is excellent in workability and gives high strength.

[0002]

2. Description of the Related Art Heat insulating materials and sound absorbing materials made of glass wool or rock wool are widely used in houses, facilities and the like due to their excellent characteristics. Water-soluble phenolic resins are mainly used as binders to improve their mechanical strength and to maintain their shapes.

For several years, it has been customary to modify water-soluble phenolic resins with urea in order to reduce binder costs. In addition, urea has the property of binding free formaldehyde like ammonia. The modification of water-soluble phenolic resins with urea has already been carried out in the field during the production of phenolic resins or shortly before the processing of insulation.

Suitable raw materials for glass or rock wool include glass, basalt, and various clinker materials. These raw materials are melted and processed into fibers, where the aqueous phenolic resin solution is sprayed and subsequently sucked on the conveyor belt at the bottom of the cotton collecting chamber. The resulting felt is compressed and conveyed with a conveyor belt through a curing chamber. There, the phenolic resin is cured by hot air flowing from below through the mat.

Further, an ammonium salt such as ammonium sulfate is used as a curing accelerator to promote a high condensation reaction. The curing accelerator is added in an amount of 1 to 5 parts based on 100 parts of the total solid content of the water-soluble phenol resin and urea at the time of producing the phenol resin or immediately before processing the heat insulating material.

However, although a curing accelerator is added to accelerate the curing reaction, the amount of heat required for curing is high,
Hot air of about 80 ° C. is used. Further, the strength of the glass wool or rock wool heat insulating material manufactured in a low temperature range of about 200 ° C. is lower than that of a material cured in a high temperature range of about 280 ° C.

[0007]

By replacing an ammonium salt such as ammonium sulfate, which has been conventionally used as a curing accelerator, with sodium carbonate, it is possible to obtain a curing agent having a viscosity of 200 to 22%.
The present invention enables complete curing in a low temperature range of 0 ° C., and as a result, the amount of heat required for curing can be kept low, thereby making it possible to obtain a low-cost binder for glass wool or rock wool insulation.

[0008]

SUMMARY OF THE INVENTION The present invention is a binder composition for a glass wool or rock wool heat insulating material comprising a resin obtained by adding sodium carbonate as a curing accelerator to an aqueous phenol resin solution.

As the water-soluble phenol resin used in the present invention, a water-soluble phenol resin generally used as a binder for a glass wool or a rock wool heat insulating material can be used.

That is, 1 to 5 moles of formaldehyde are added to 1 mole of phenol, and a basic catalyst is added to adjust the pH to 7.
It is obtained by adjusting the reaction system to 5 to 12.0 and reacting at 50 to 100 ° C. for a predetermined time. These are manufactured by adding processes such as neutralization, concentration, dilution, and filtration as needed.

Urea is added so that the solid content ratio of the water-soluble phenolic resin and urea is in the range of 50:50 to 100: 0, and a premix reaction is performed at 25 to 40 ° C. for a predetermined time, and denaturation with urea is performed. It is carried out.

The curing accelerator which is a solution is added immediately after the production of the water-soluble phenol resin or immediately before processing the heat insulating material. When the addition amount of the curing accelerator exceeds 5 parts with respect to the total solid content of 100 parts of the premix liquid of the water-soluble phenol resin and urea, the curing acceleration effect becomes saturated, and conversely, the addition amount is 0.5%. If the amount is less than 10 parts, no hardening promoting effect appears.
Therefore, the addition amount of sodium carbonate as a curing accelerator is preferably 0.5 to 5 parts with respect to 100 parts of the total solid content of the premix liquid of the water-soluble phenol resin and urea.

[0013]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The parts and percentages in the examples are on a weight basis unless otherwise specified.

Synthesis Example 1 A three-necked flask equipped with a thermometer and a condenser was charged with 100 g of phenol, 191.3 g of a 50% aqueous formaldehyde solution, and 10 g of barium hydroxide, and heated to 60 ° C. with stirring, and then at 60 ° C. for 3 hours. The reaction was performed. Next, 19 g of a 30% sulfuric acid aqueous solution was added to neutralize the reaction system, the reaction was terminated, and the mixture was cooled to obtain a water-soluble phenol resin.

The characteristics of the obtained resin are as follows:
Water dilution ratio was 20 times or more, pH was 7.3, and free formaldehyde was 10%.

[Synthesis Example 2] 100 g of the water-soluble phenol resin obtained in Synthesis Example 1 was mixed with 75 g of a 40% aqueous urea solution, heated to 30 ° C. with stirring, and then heated at 30 ° C.
A time premix reaction was performed. After the reaction, 25% aqueous ammonia was added to adjust the pH to 9.0.

Further, 9.0 g of a 25% aqueous solution of ammonium sulfate was added as a curing accelerator to obtain a preparation.

[Synthesis Example 3] A premix reaction was performed in the same manner as in Synthesis Example 2. After the reaction, 25% aqueous ammonia was added,
It was adjusted to 9.0. Further, 9.0 g of a 25% aqueous sodium carbonate solution was added as a curing accelerator to obtain a preparation.

[Example 1] The mixture prepared in Synthesis Example 3 was diluted with water so that the total solid content of the water-soluble phenolic resin and urea was 10%, sprayed onto melt-spun glass wool, and hot-pressed. Each at 200-220 ° C using
The mixture was cured for 0 to 40 minutes to obtain a glass wool heat insulating material having a density of 32 kg / m ³ .

[Comparative Example 1] The solution prepared in Synthesis Example 2 was diluted with water so that the total solid content of the water-soluble phenolic resin and urea was 10%, sprayed on melt-spun glass wool, and hot-pressed. Each at 200-220 ° C using
The mixture was cured for 0 to 40 minutes to obtain a glass wool heat insulating material having a density of 32 kg / m ³ .

The load applied when the glass wool heat insulating material obtained in Example 1 and Comparative Example 1 was compressed by 20% of the height was determined, and the compressive strength was calculated.

Tables 1 to 3 show the compressive strengths of the glass wool insulating materials depending on the curing temperature.

[0023]

[Table 1] Compressive strength by curing at 200 ° C (kgf / m ² )

[0024]

Table 2 Compressive strength by curing at 210 ° C (kgf / m ² )

[0025]

Table 3 Compressive strength by curing at 220 ° C (kgf / m ² )

[0026]

By using sodium carbonate as a curing accelerator for a binder for glass wool or rock wool insulation, it is possible to completely cure the resin in a low temperature range of 200 to 220 ° C., resulting in excellent mechanical strength. A low cost binder for glass wool or rock wool insulation can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomoaki Motoya 700 Sukuodaizaimachi, Takasaki City, Gunma Prefecture Inside Gunei Chemical Industry Co., Ltd. Inside the corporation

Claims (3)

[Claims] 1. A binder composition for heat insulating glass wool or rock wool, comprising a water-soluble phenol resin using sodium carbonate as a curing accelerator for the binder and urea. 2. The glass wool or rock wool heat insulating binder composition according to claim 1, wherein the mixing ratio of the water-soluble phenol resin and urea is in the range of 50:50 to 100: 0 in terms of solid content ratio. 3. The binder composition for glass wool or rock wool insulation according to claim 2, wherein sodium carbonate is added in an amount of 0.5 to 5 parts based on 100 parts of the total solid content of the water-soluble phenol resin and urea.