JPH1036533A - Production of resin-based material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a resin-based material containing a formaldehyde- vaporizing resin such as a phenol resin having reduced vaporization of formaldehyde. SOLUTION: An amount of vaporized formaldehyde is reduced by irradiating an ionizing radiation to a resin-based material containing a formaldehyde- vaporizing resin as a component under an inert gas atmosphere. As the resin- based material, any form described below is suitable, a formaldehyde-vaporizing resin, a plywood in which a formaldehyde-vaporizing resin is used as an interlaminar adhesive, a particle board or a wood fiber board using the formaldehyde vaporizing resin as a binder, a composite product prepared by kneading or impregnating the formaldehyde-vaporizing resin with a fibrous material or a decorative laminated sheet prepared by laminating a decorative sheet on a base material through an adhesive layer containing the formaldehyde- vaporizing resin as a component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to resin-based materials, wood plywood, particle board, MD
The present invention relates to a method for producing a wood-based material such as F, and a resin-based material such as FRP, in which the amount of formaldehyde contained therein is reduced.

[0002]

Taking wood plywood as an example, phenolic resin and urea-formaldehyde resin, which are inexpensive and have high adhesive strength, have been widely used as interlayer adhesives. However, since these adhesive resins emit formaldehyde (formalin) over time, they give off formalin odor and cause pain in the eyes (especially at high concentrations).
Due to such drawbacks, the following attempts have been made to improve this. Urea / formalin-based, melamine-based, phenol-based adhesives are changed to those that do not emit formaldehyde, such as vinyl acetate emulsions, resorcinol resins, and epoxy resins. A formaldehyde scavenger is mixed into the adhesive (for example, see Japanese Patent Publication No. Hei 7-110484). A formaldehyde scavenger or a resin mixed with a scavenger is applied to the surface of a wooden material (see, for example,
No. 42164). A paper impregnated with a formaldehyde scavenger, a nonwoven fabric, or the like is attached to the back surface of the decorative plate (for example, see JP-A-56-121)
713).

However, in the above-mentioned methods, the cost of the adhesive used is higher than that of urea / formalin-based adhesives and the like, and the temporary adhesiveness is poor, and the number of non-defective products at the time of production is reduced. There are disadvantages, and it is necessary to change the processing conditions for each adhesive. In addition, the methods (1) to (4) not only increase the cost, but also the methods (1) and (2) require that the amount of formaldehyde adsorbed and released during the manufacturing process cannot be captured, and that the amount of the adhesive must be changed depending on the grade. There are drawbacks that the number of types increases and that the end face treatment is difficult.In the method, it is necessary to consider the adhesion with the decorative sheet to be attached to the surface, and there is a disadvantage that the end face treatment is difficult. However, when printing on an impregnated substrate, there is a drawback that printability is poor.

[0004] In the case of a so-called decorative melamine resin board or a wood board coated with an amino alkyd resin, which is a laminate of a melamine resin impregnated paper and a phenol resin impregnated paper, formaldehyde is also emitted from the resin component. Therefore, in this case, as a countermeasure, it has been proposed to add a formaldehyde scavenger to the resin itself or an adhesive for laminating the decorative board to another base material. However, if formaldehyde is mixed into the adhesive, problems such as a decrease in adhesive strength, a change in the composition of the adhesive, a change in the bonding conditions, and an increase in cost will occur, and furthermore, if formaldehyde adsorbed on the surface of the decorative plate cannot be prevented from being emitted, it cannot be prevented. There's the problem I said. In addition, when formaldehyde is mixed into the paint, problems such as a decrease in surface properties (hardness, etc.), a change in curing conditions, and a rise in cost occur.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a resin-based material containing a formaldehyde-emitting resin such as a phenol resin, and to reduce the emission of formaldehyde. It is an object of the present invention to provide a method of manufacturing a resin-based material with reduced amount.

[0006]

Means for Solving the Problems In order to achieve the above object, a method for producing a resin material according to the present invention comprises the steps of:
The method is characterized in that the amount of emitted formaldehyde is reduced by irradiating with ionizing radiation in an inert gas atmosphere.

The above-mentioned resin-based materials include a formaldehyde-dispersing resin alone, a wood plywood (including a so-called laminated wood) using the formaldehyde-dispersing resin as an adhesive between layers,
Particle board or wood fiber board (MDF, etc.) using formaldehyde-emitting resin as binder, formaldehyde-emitting resin kneaded or impregnated with fibrous material and compounded (FRP in a broad sense), formaldehyde-emitting property to various substrates It may be in any form of a decorative board in which various decorative sheets are adhered via an adhesive layer containing a resin as a component.

According to the above-mentioned production method, a special additive is unnecessary regardless of the type of the resin material, the thickness direction is uniform, the end face treatment is simultaneously performed, and the amount of formaldehyde in the resin material is instantaneously reduced. be able to.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the formaldehyde-emitting resin include a phenol resin obtained by condensation polymerization of phenol (carbonic acid) and formaldehyde, a urea (or urea-formaldehyde) resin obtained by polymerization of urea and formalin, and an alkyd resin. Aminoalkyd resins, melamine resins, and the like obtained by adding melamine resins, urea resins, guanamine resins, and the like. It is believed that the presence of formaldehyde in the resinous material is mainly due to the following reasons. That is, when the resin remains as an unreacted material, when it is left as a resin during a curing reaction (heating and pressurizing), when it remains as a material captured by a material other than resin (wood, paper, and the like), and the like. . In this way, what was present in the resin-based material is gradually released and released.

As the simple formaldehyde-emitting resin, there are a molded article, a plate, a sheet, and various three-dimensional shapes made of the formaldehyde-emitting resin. As the wood used for the wood plywood, particle board or wood fiber board, those commonly used such as oak, cedar, pine, zelkova, oak, lauan, teak and the like are used.

Examples of the fibrous material to be kneaded or impregnated with a formaldehyde-emitting resin include high-quality paper, paper such as kraft paper, titanium paper and Japanese paper, inorganic fibers such as glass fiber, carbon fiber and asbestos, hemp, cotton and vinylon. And woven or non-woven fabrics made of organic fibers, and further, short fibers obtained by cutting the inorganic or organic fibers into about 1 to 10 mm. Those obtained by kneading or impregnating the resin with these fibrous materials and curing are so-called FRP, and a melamine resin decorative board is also included in this.

In a decorative board in which various base materials and various decorative sheets are adhered with an adhesive layer interposed therebetween, the various base materials may be a wooden board (single board, or the above-mentioned wood plywood, particle board, wood fiber, etc.). Plate, a metal plate, a cement plate, a calcium silicate plate, a ceramic plate and the like. As the various decorative sheets, sheets obtained by subjecting sheets such as paper, nonwoven fabric, and synthetic resin sheets to decorative treatments such as painting, picture printing, and embossing of uneven patterns are used.

Although the type of inert gas used in the present invention is not limited, nitrogen gas is preferred from the viewpoint of cost and availability.
In addition, a gas of an inert gas element (a rare gas element) such as a helium gas, a neon gas, and an argon gas may be used.
And when considering the economics when irradiating the resin-based material with ionizing radiation, after placing the resin-based material in a hermetically sealed container, the gas in the container is replaced with an inert gas such as nitrogen gas, It is preferable to irradiate the whole container with the stopper in a closed state.

Here, ionizing radiation means electron beam, X-ray,
Refers to high energy ionizing radiation such as gamma rays. That is, it is necessary to have energy capable of penetrating a substrate of several mm to several cm. In the case of an electron beam, a high energy type electron beam is used. That is, an accelerating voltage of 1 MeV or more is used. As the irradiation device,
An electron beam accelerator such as a Cockcroft-Walton type, a Van de Graaff type, a resonance transformer (such as a Tesla coil) type, or a linear accelerator type is used. Alternatively, beta rays emitted from radioactive nuclei may be used. Gamma rays basically have higher energy than electron beams, so there is basically no energy limitation. As a line type, for example, 1.
Gamma rays of 17 MeV and 1.33 MeV are used.

The resin-based material of the present invention may be subjected to decoration processing such as pattern printing, vapor deposition of a metal thin film, sticking of a decorative sheet, embossing of an uneven pattern, etc., if necessary.

The resin-based material of the present invention is formed into sheets, plates (flat plates, curved plates, etc.), various three-dimensional shapes, and, if necessary, cut into various dimensions and shapes. After processing and laminating with various materials, ceiling, floor,
It is used for building interior materials such as walls, furniture such as chests and desks, cabinets for light electric equipment such as television receivers, containers such as boxes, interior materials for vehicles such as automobiles and trains, and interior materials for aircraft.

[0017]

【Example】

(Example 1) Raw material is used as the material type, and the total thickness is 5.5 m.
m was laminated by a hot press to produce a plywood. The number of layers was three, and a urea-formaldehyde resin was used as an interlayer adhesive. The plywood was irradiated with ionizing radiation under the following conditions. Ionizing radiation type: electron beam Irradiation device: Cockcroft-Walton electron accelerator Acceleration voltage: 2 MeV Irradiation dose: 15 kGy Number of irradiation: 1 Irradiation atmosphere: in nitrogen gas

Example 2 One sheet of titanium paper having a basis weight of 100 g / m ² impregnated with a melamine resin was superimposed on two sheets of phenol resin-impregnated paper, and room temperature was maintained at a pressure of 100 kg / cm ^2. The temperature is raised from the temperature to 130 ° C. and heated for 10 minutes.
I got This FRP was irradiated with ionizing radiation under the same conditions as in Example 1.

(Example 3) A 5 mm-thick plate made of a thermosetting phenol resin was prepared.
Irradiation was carried out under the same conditions as described above.

Example 4 A particle board having a thickness of 10 mm was prepared by bonding urea / formalin-based resin as a binder and wood powder. This particle board was irradiated with ionizing radiation under the same conditions as in Example 1.

(Example 5) A 10 mm thick cedar veneer was
Urea-formalin resin adhesive 30 g / m ² was applied,
A decorative paper having a printed pattern on its surface and having a basis weight of 50 g / m ² was overlaid so that the printed pattern became the outer surface, and was adhered with a hot press to obtain a decorative plate. This was irradiated with ionizing radiation under the same conditions as in Example 1.

<Evaluation of the amount of formaldehyde>
Resin-based materials which were not subjected to the irradiation step in Comparative Example 5 were referred to as Comparative Examples 1 to 5, respectively. Quantitative evaluation according to the `` emission test ''
The results shown in Table 1 were obtained. From this result, it can be seen that the amount of formaldehyde has been reduced after the irradiation step of ionizing radiation.

[0023]

[Table 1]

[0024]

As described above, according to the production method of the present invention, the formaldehyde present in the resin material can be instantaneously reduced, and the emission of formaldehyde over time can be sufficiently reduced. it can. Further, it is only necessary to irradiate with ionizing radiation, and no extra additives are required.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08J 5/04 CFA C08J 5/04 CFA

Claims (6)

[Claims] 1. A method for producing a resin-based material, comprising irradiating a resin-based material containing a formaldehyde-emitting resin as a component with ionizing radiation in an inert gas atmosphere to reduce the amount of emitted formaldehyde. 2. The method for producing a resin-based material according to claim 1, wherein the resin-based material is a simple formaldehyde-emitting resin. 3. The method for producing a resin-based material according to claim 1, wherein the resin-based material is a wood plywood using a formaldehyde-emitting resin as an adhesive between layers. 4. The method for producing a resin-based material according to claim 1, wherein the resin-based material is a particle board or a wood fiber board using a formaldehyde-emitting resin as a binder. 5. The method for producing a resin-based material according to claim 1, wherein the resin-based material is a compound obtained by kneading or impregnating a formaldehyde-emitting resin with a fibrous material. 6. The resin according to claim 1, wherein the resin-based material is a decorative plate obtained by attaching a decorative sheet to a base material via an adhesive layer containing a formaldehyde-emitting resin as a component. Manufacturing method of base material.