JPH11114924A - Fiber board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fiber board, which has the same order of density as that of a non-rigid fiber board and the bending strength equal to that of a rigid fiber board by a method wherein a foaming resin composition consisting of the aqueous solution of glucides, a reaction catalyst and a polyisocyanate compound is fed to fibers and mixed with them so as to be foamed and hardened in the gaps of the fibers in the state being formed in a mat. SOLUTION: As glucides, monosaccharides such as a glucose and a fructose and disaccharides such as a maltose, a lactose or the like are example. The glucides are used in an aqueous solution and its preferable water content is 25-40 wt.%. As a polyisocyanate compound, such as a diphenylmethane diisocyanate, a polymethylenephenyl polyisocyanate or the like is exampled. As a reaction catalyst, a metal compound-based catalyst such as an organic tin compound, which accelerates the reaction between an active hydrogen- containing group and an isocyanate group, or the like and a tertiary amine catalyst such as a triethylenediamine or the like. Further, in order to obtain a favorable foam, a foam stabilizer, a flame-retardant, a filler or the like are used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The fiberboard obtained according to the present invention is:
Used for building interior and exterior materials, furniture, automotive interior materials, cabinets for electrical products, etc.

[0002]

2. Description of the Related Art Generally, there are two methods for producing fiberboard: a wet method and a dry method. In the case of the wet method, water is dispersed in defibrated wood fibers, pulp, etc., and a sizing agent (rosin, asphalt,
After uniformly adhering to the fiber using paraffin, phenolic resin, amino resin, starch, etc.), forming into a uniform thickness, passing through a dehydration step, and drying or hot pressing to produce a plate-like fiberboard.

In the case of the dry method, a phenol resin, an amino resin, or the like is well mixed as a binder with defibrated wood fibers or the like, and after uniform forming, a plate-like fiber board is manufactured by hot pressing.

[0004] The physical properties of the fiberboards produced by the respective methods are standardized in Japanese Industrial Standards (hereinafter JIS) as shown in Tables 1, 2 and 3. (JIS A5905,
5906, 5907)

[Table 1] JIS A 5905 soft fiberboard

[Table 2] JIS A 5906 medium fiberboard

[Table 3] JIS A 5907 hard fiberboard

[0005] Flexural strength 200 kgf / cm ² or more fiberboard belongs to Hardboard requires density 0.8 g / cm ³ or more, wood containing fiberboard density 0.4 to 0.8 g / cm ³ Has a lower limit of flexural strength of 50 kgf / cm ² , and commercially available medium fiberboard is almost close to this lower limit.
Further, a density of 0.4 g / cm ³ or less belongs to a soft fiber board, and the lower limit of the bending strength is 30 kgf / cm ² even for the strongest insulation board, and most of the soft fiber boards only meet this lower limit. It is a level to clear.

[0006]

SUMMARY OF THE INVENTION In the case of automobile interior materials,
In light of energy saving measures, there is a strong tendency to reduce the weight. In particular, the ceiling portion is required to have heat insulation properties so as not to deteriorate indoor living conditions and high rigidity as a mechanical property.

Building materials are also required to be lightweight for the purpose of improving workability and simplifying jigs.

However, in the conventional fiberboard, as described above, when the density is reduced, the bending strength is significantly reduced, and to increase the bending strength, the density must be significantly increased.
Bending strength can be improved to some extent by increasing the amount of binder, but the density tends to increase, making it difficult to mix a large amount of binder uniformly and increasing the cost. . Therefore, if a fiberboard having the same density as the soft fiberboard and the same bending strength as the hard fiberboard can be obtained, it is possible to save energy and reduce the total cost.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a foaming resin composition containing an aqueous solution of a saccharide, a reaction catalyst, and a polyisocyanate compound to fibers. It is intended to provide a lightweight and high-flexibility fiberboard by mixing, matting and foam-hardening the voids in the fibers.

[0010]

The saccharides used in the present invention include monosaccharides such as glucose, fructose, xylose and mannose; disaccharides such as maltose, lactose, trehalose and sucrose; and oligosaccharides including dextrin; Sugar alcohols such as sorbitol, maltitol, xylitol and mannitol, and glucosides such as methylglucoside and ethylglucoside are preferred, and one or more of these may be used in combination.

The saccharide is used as an aqueous solution, and the water content at this time is preferably 25 to 40% by weight.

As the polyisocyanate compound used in the present invention, for example, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, tolylene diisocyanate and partially modified isocyanate thereof are preferable. You may mix and use.

As the reaction catalyst, a metal compound catalyst such as an organotin compound which promotes the reaction between an active hydrogen-containing group and an isocyanate group, and a tertiary amine catalyst such as triethylenediamine are used.

A foam stabilizer, a flame retardant, a filler and the like for obtaining a good foam can be optionally used.

Fibers include wood fibers used for hard fiber boards, medium fiber boards, soft fiber boards, etc., inorganic fibers such as glass fibers or rock wool used for heat insulating materials and sound absorbing materials, felts, cloths, and the like. It refers to natural fibers such as cotton, wool, and hemp, and various synthetic fibers such as nylon, polyester, and acrylic used for yarns and the like.

[0016] The foaming resin composition used in the present invention is 5 to
It foams 50 times and hardens. Due to this foaming force, the resin composition for foaming penetrates into the interior of the matted fibers and hardens after sufficiently filling the voids, so that the bonding force between the fibers is increased. The foaming resin composition filling the voids has a density of 0.02 to
It is as light as 0.2 g / cm ³ and high strength can be obtained without increasing the density of the fiberboard. Therefore, the fiberboard obtained by the present invention is lightweight and has high bending strength.

[0017]

The present invention will now be described in detail with reference to Examples.
The present invention is not limited to these examples. The composition of the foaming resin composition used in the examples is as follows. [Foaming resin composition A] 70 parts by weight of glucose, 30 parts of water
Make an aqueous solution containing a mixture of 2 parts by weight of SH-193 manufactured by Dow Corning Toray Silicone Co., Ltd.
(Trichloroethyl phosphate) (15 parts by weight) was blended to prepare a resin solution. 5 parts by weight of triethylenediamine as a catalyst and 100 parts by weight of Cosmonate M-200 (polymethylene polyphenyl polyisocyanate, manufactured by Mitsui Toatsu Chemicals, Inc.) as polyisocyanates were added and mixed. [Foaming resin composition B] An aqueous solution was prepared by mixing 40 parts by weight of trehalose, 30 parts by weight of maltose, and 30 parts by weight of water, and 2 parts by weight of SH-193 manufactured by Dow Corning Toray Silicone Co., Ltd. as a foam stabilizer. As a flame retardant, 15 parts by weight of CLP (trichloroethyl phosphate) manufactured by Daihachi Chemical Industry Co., Ltd. was blended to prepare a resin liquid. 5 parts by weight of triethylenediamine as a catalyst and Cosmonate M-2 manufactured by Mitsui Toatsu Chemicals, Inc. as polyisocyanates.
00 (polymethylene polyphenyl polyisocyanate)
100 parts by weight were added and mixed.

Example 1 60 g of resin composition A for foaming was supplied to 240 g of wood fiber, and the mixture was uniformly mixed with a Henschel mixer. Next, spread it evenly on a 300 × 300 × 10 mm metal frame, and press it at 100 ° C. under a molding pressure of 20 kg.
The mold was clamped at f / cm ² for 5 minutes to obtain a fiberboard. The density of the obtained fiberboard is 0.33 g / cm ³ and the bending strength is 170 k.
gf / cm ² .

Example 2 90 g of the resin composition A for foaming was supplied to 270 g of glass fiber and uniformly mixed with a Henschel mixer. Next, a fiberboard was obtained in the same manner as in Example 1. The density of the obtained fiberboard was 0.38 g / cm ³ and the bending strength was 200 kgf / cm ² .

Example 3 90 g of the resin composition B for foaming was supplied to 270 g of glass fiber and uniformly mixed with a Henschel mixer. Next, a fiberboard was obtained in the same manner as in Example 1. The density of the obtained fiberboard was 0.38 g / cm ³ and the flexural strength was 230 kgf / cm ² .

Example 4 To 300 g of raw cotton used for forming felt, 75 g of the foaming resin composition B was supplied and uniformly mixed with a Henschel mixer. Next, a fiberboard was obtained in the same manner as in Example 1. The density of the obtained fiberboard is 0.40
g / cm ³ and bending strength 200 kgf / cm ² .

Example 5 125 g of resin composition B for foaming was supplied to 315 g of glass fiber and uniformly mixed with a Henschel mixer. Next, a fiberboard was obtained in the same manner as in Example 1. The density of the obtained fiberboard was 0.48 g / cm ³ , and the flexural strength was 310 kgf / cm ² .

Example 6 A foaming resin composition B (50 g) was supplied to 170 g of polyester fiber and uniformly mixed with a Henschel mixer. Next, a fiberboard was obtained in the same manner as in Example 1. The density of the obtained fiberboard is 0.23 g / cm ³ ,
The flexural strength was 65 kgf / cm ² .

It was confirmed from the cut surface that the fiberboards of Examples 1 to 6 were all filled with the foam.

Comparative Example 1 30 parts by weight of a powdery novolak type phenol resin (PG-4725, manufactured by Gunei Chemical Industry Co., Ltd.) containing 10 parts by weight of hexamine was mixed and adhered to 100 parts by weight of raw cotton used for forming felt. , Matted. Next, the mat was molded by a molding press under the conditions of 200 ° C., a molding pressure of 25 kg / cm ² , and a molding time of 60 seconds to obtain a molded felt. The density of the obtained molded felt is 0.
It was 65 g / cm ³ and the flexural strength was 150 kgf / cm ² .

Comparative Example 2 30 parts by weight of a powdery novolak type phenol resin (PG-4725, manufactured by Gunei Chemical Industry Co., Ltd.) containing 10 parts by weight of hexamine was mixed and adhered to 100 parts by weight of wood fiber to form a mat. . Next, the mat was pressed at 210 ° C. with a molding pressure of 30 kg / cm ² ,
Molding was performed under the condition of a molding time of 60 seconds to obtain a wood fiber board. The density of the obtained wood fiber board was 0.80 g / cm ³ and the bending strength was 220 kgf / cm ² .

Table 4 shows the characteristic values of the fiber boards obtained in Examples and Comparative Examples, together with the thermal conductivity. As shown in Table 4, the fiberboard obtained by the method of the present invention is lightweight, has high bending strength, and is excellent in heat insulation.

[Table 4] Fiberboard characteristic values

[0028]

According to the fiberboard manufacturing method of the present invention,
Since the resin composition for foaming is foam-filled in the fiber, the bonding strength of the fiber is increased, and a lightweight fiberboard having high bending strength can be easily manufactured without increasing the density because of the lightweight filler. In particular, the fiberboard obtained by the method of the present invention using inorganic fibers has excellent properties such as light weight, excellent bending strength, and excellent heat insulation properties, and is suitable as an excellent automotive interior material, for example, a ceiling material. .

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshitaka Kakegawa 700 Shukudaidaicho, Takasaki City, Gunma Prefecture Inside Gunei Chemical Industry Co., Ltd. In company

Claims (3)

[Claims] 1. A foaming resin composition comprising an aqueous solution of a saccharide, a reaction catalyst, and a polyisocyanate compound is supplied to a fibrous material, mixed and then matted and foamed and cured in voids in the fiber. Fiberboard. 2. The fiberboard according to claim 1, wherein the water content of the saccharide is 25 to 40% by weight. 3. The fiberboard according to claim 1, wherein the fiberboard has a density of 0.2 to 0.5 g / cm ³ and a bending strength of 50 to 400 kgf / cm ² .