JPS60246252A - Manufacture of mineral fiber board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing mineral fiberboard used as a building material for houses and the like.

Structure of conventional example and its problems When manufacturing mineral fiberboard by mixing mineral fibers with water and a binder to form a slurry, wet-forming the slurry, and dewatering and drying the resulting wet mat, the conventional method Starch has been used as a binder for mineral fiberboard since it can provide a binding effect when added in small amounts, but the resulting mineral fiberboard has poor water resistance and has the disadvantage that the fiberboard bends due to moisture absorption.

For this reason, polyvinyl alcohol (hereinafter referred to as
However, although this poval itself has a binding effect similar to starch, and its water resistance is considerably improved compared to starch, the strength retention rate when water is absorbed is still lower than the normal strength. Since it is around 30%, it is still insufficient for use in relatively humid environments.

In addition, phenolic resin is also known as a water-resistant binder, but in the wet papermaking method, it is less effective as a binder because it does not gelatinize and swell like starch or zavar. In order for the quality fiberboard to maintain its normal strength, it is necessary to add a large amount of it, resulting in problems such as a decrease in corrosion resistance and an increase in price.

Purpose of the Invention The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to improve the bonding of mineral fibers during papermaking and to significantly improve water resistance by adding a small amount of a water-resistant agent. The present invention provides a method for manufacturing a mineral fiberboard.

Structure of the Invention In order to achieve the above object, the method for manufacturing a mineral fiberboard of the present invention involves forming a wet mat by wet paper-making mineral fibers using poval as a binder, and then forming a wet mat by using poval as a binder.
) is coated with a water-resistant agent solution that reacts with the OH group of Poval.
A mineral fiberboard having excellent water resistance is obtained by impregnating it and then heating and drying it.

In the method of the present invention, the addition 11 of poval mixed into the slurry during papermaking of mineral fibers is not particularly limited;
The content is preferably 3 to 70% by weight so as not to impair fire protection.

In addition, as the water resistance agent that reacts with the OH group of this poval, acid-curable aminoaldehyde resins such as urea resin and melamine resin, such as urea formaldehyde resin, melamine,
Formaldehyde resin, polyamide Formaldehyde resin; Bryoxal (highly reactive dialdehyde): Alkali-curing ketone aldehyde resin, epoxy polyamide resin; Representative examples include chromium, anti-hydrogen, metal salts such as zirconium, such as zirconium carbonate and zirconium nitrate. There are heavy metal salts and the like, and one or more of these water-resistant agent solutions are applied to the wet mat or sheet to impregnate the inside.

The amount of impregnation of this waterproofing agent is 3% in terms of solid content based on Poval.
In this case, in order to further improve the water resistance of the obtained mineral fiberboard, a thermosetting synthetic resin such as a phenol resin may be added internally or after the wet mat is formed, it may be impregnated with a waterproofing agent. However, it is preferable that the total organic content is within an acceptable range as a noncombustible material or a semi-noncombustible material.

Impregnation methods include applying a water-resistant agent solution to the surface of the wet mat and then suctioning it from the back side of the wet mat using an appropriate air suction device to impregnate it under reduced pressure, or applying air pressure to the front side of the wet mat. There are methods to impregnate the wet mat under pressure, and there are also methods to pressurize the surface of the wet mat with a flat plate or roll to impregnate the inside.
One or more of these methods may be used in combination.

The water resistant agent is impregnated into the wet mat after papermaking, as it is necessary to impart water resistance after the POVAL has swelled and sufficiently acted as a binder. This makes it even more water resistant.

Note that POVAL may be one that dissolves in water or hot water and becomes gelatinized, and may be one that has been modified in advance to give it water resistance, but it may be one that has been modified so that it does not dissolve in water. is inappropriate.

The mineral fiberboard thus obtained has low water absorption, hardly bends when water is absorbed, and exhibits excellent water resistance.

Description of examples Next, examples of the present invention will be shown.

Example L After forming a wet mat by wet paper-making a slurry of rock wool:poval mixed in a ratio of qs:s<weight ratio, an aqueous solution of melamine resin tpoval was applied to the surface of the wet mat. The resin solid content was applied so that the impregnation rate was 3%, and the wet mat was impregnated into the inside of the wet mat by applying reduced pressure or pressurization.

Next, the poval and melamine resin solutions were dried by heating at 110° C. for an hour using a dryer, and the strength of the mineral fiberboard thus obtained is shown below.

Example 2 In Example 1 above, an aqueous solution of zirconium nitrate was used in place of the melamine resin at a resin solid content of 0.3% based on Poval.
Apply and impregnate the surface of the wet mask so that
After that, it was heated with a hair dryer for 17 hours.
At the same time as heating and drying, Poval and zirconium nitrate were reacted.

The strength of the mineral fiberboard thus obtained is shown below.

Comparative Example Starch, poval, and powdered phenolic resin were used as binders for mineral fibers, and a slurry having a mixing ratio of 5% by weight with respect to rock wool was wet-formed to form a wet mat, which was then dried.

The strengths of the mineral fiberboards obtained in this way were measured in Comparative Examples 1 to 1, respectively.
It is displayed below as 3.

In addition, in the table, the water absorption bending strength indicates the strength after impregnating the mineral fiberboard with water for 2 hours.

As is clear from the above table, the mineral fiberboard obtained in Example 1 is 50% or more superior in strength retention upon water absorption than the mineral fiberboard obtained in Comparative Example.

Effects of the Invention As described above, according to the method for manufacturing mineral fiberboard of the present invention, the wet mat is impregnated after papermaking without adding a waterproofing agent during papermaking, so that poval becomes water resistant during papermaking. Like starch, it swells and gelatinizes in water to sufficiently bind the mineral fiberboard, and it can effectively adhere to the intersections of fibers to obtain a mineral fiberboard with high normal strength. Furthermore, since the wet mat is impregnated with a water-resistant agent after papermaking, it does not dissolve into the sea urchin/cytomat and can be reliably fixed with the minimum amount necessary.
Mineral fiberboard with excellent water resistance that is 5 to 6 times the proportion of starch binder can be produced efficiently and at low cost.

Patent applicant: Daiken Kogyo Co., Ltd. Bi in 4- - + I-J, ゛-'

Claims (1)

[Claims] ■ y +) After forming a wet mat by wet paper-making mineral fibers using vinyl alcohol as a binder, the wet mat is coated and impregnated with a water-resistant agent solution that reacts with the OH groups of polyvinyl alcohol. 1. A method for producing mineral fiberboard, which comprises drying the mineral fiberboard by heating and drying. ■ After applying the water resistant agent, apply pressure and/or
A method for manufacturing a mineral fiberboard according to claim 1, characterized in that the wet mat is impregnated with a water-resistant agent by reducing the pressure. (2) The water-resistant agent is an aminoaldehyde resin, glyoxal, ketone aldehyde resin, Epoxy polyamide resin,
The method for producing a mineral fiberboard according to claim 1 or 2, which comprises one or more heavy metal salts. (2) A method for manufacturing a mineral fiberboard according to claim 1, 2 or 3, characterized in that the wet mat is coated and impregnated with a thermosetting synthetic resin liquid together with a waterproofing agent.