JP2002265558A - Curable resin composition and decorative member therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable resin composition that solves such problems that thermosetting resins such as melamine resins require a great amount of energy in impregnation, drying and molding of the resins in the working of laminates, emit solvents, gases, etc., to the atmosphere in the course of the working steps, for example, and accordingly, face demands for improvement from the environmental viewpoint, that the cured resins are brittle, and that improvement of chemical resistance or other performance is hard to be realized with the conventional resins. SOLUTION: Problems regarding the conventional thermosetting resins can be solved by a curable resin composition containing a triazine ring-containing methacrylate prepolymer synthesized from an aminotriazine compound, formaldehyde and a hydroxyl group-containing methacrylate, and a compound having an isocyanate group in a molecule, or containing at least a resin composition obtained by reacting these compounds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a curable resin composition and a decorative material processed using the same.

[0002]

2. Description of the Related Art Conventionally, a curable resin, for example, a melamine resin has excellent heat resistance, high hardness, stain resistance, etc., and is not colored but white, so that an initial condensate is impregnated into a substrate such as cellulose paper. A molded product was obtained by lamination molding after drying. However, it is bad for the environment because it releases solvent, formaldehyde gas, etc. to the outside air in the drying and molding processes.
Further, there remains a problem that a large amount of energy is consumed in the processing step. In addition, the resin itself is very brittle, so that it is limited to a specific use.

In order to solve these problems, a triazine ring-containing (meth) acrylate prepolymer synthesized from an aminotriazine compound, formaldehyde and a hydroxy group-containing (meth) acrylate has been studied. However, it still has a high degree of chemical and weather resistance,
It was not suitable for applications requiring heat resistance, water resistance and the like.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, that is, it does not release solvents, gases, etc. to the outside air in the processing step, does not consume much energy, and reduces the conventional brittleness. It is an object of the present invention to provide a curable resin composition which can be expected to have improved properties such as water resistance, chemical resistance, weather resistance and the like, and a cosmetic material using the same.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a curing method comprising a triazine ring-containing (meth) acrylate prepolymer (hereinafter simply referred to as a prepolymer) synthesized from an aminotriazine compound, formaldehyde and a hydroxyl group-containing (meth) acrylate. A curable resin composition comprising at least a curable resin composition containing / reacted with a compound having an isocyanate group in the molecule. Finishing through coating, curing or laminating, curing, etc. processes on the base material, it is possible to obtain a cosmetic material with better heat resistance, water resistance, chemical resistance, weather resistance etc. than before. Became.

Hereinafter, the present invention will be described in detail. First
The aminotriazine compound as a component is a compound having a structure in which an amino group is bonded to at least one of three carbon atoms of a triazine ring composed of C3N3, and the aminotriazine compound means aminotriazine itself or an aminotriazine derivative. Aminotriazine itself includes melamine, and aminotriazine derivatives include benzoguanamine, acetoguanamine, cyclohexanecarboguanamine and the like.

[0007] Paraformaldehyde is preferably used as the formaldehyde source of the second component.
In the present invention, it can be used by dissolving in 2-hydroxyethyl (meth) acrylate together with the aminotriazine compound. Therefore, the steps of dehydration and desolvation as in the case of using a formalin aqueous solution are unnecessary.

The third component contains a hydroxyl group (meth).
Examples of the acrylate include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate, and if necessary, a compound having an ethylenically unsaturated bond having at least one hydroxysil group, for example, 2-hydroxypropyl (meth) acrylate, -Hydroxybutyl acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, trimethylpropane mono (meth)
Acrylate, trimethylolpropane di (meth) acrylate, allyl alcohol, ethylene glycol allyl ether, glycerin (mono, di) allyl ether,
N-methylol (meth) acrylamide or the like or a mixture thereof can be added.

The prepolymer is synthesized by the following method. The synthesis reaction is the formation of a methylol group by the addition reaction of formaldehyde to the aminotriazine compound and the condensation reaction of the methylol group with the hydroxyl group of the hydroxyl group-containing (meth) acrylate, or the aminotriazine compound and the hydroxyl group-containing (meth) acrylate, formaldehyde It is understood that the reaction proceeds with a condensation reaction due to the reaction with hemiacetal. The degree of progress of the condensation reaction can be determined by the amount of water released by the condensation reaction. If the amount of water is grasped over time and the distillation of water is stopped at a predetermined stage, the condensation reaction can be controlled.

The synthesis reaction of the prepolymer can proceed in the absence of a catalyst. However, in order to promote the reaction, an alkaline substance such as caustic soda, sodium carbonate, ammonia and triethylamine is used at the time of charging, or an etherification catalyst is used at the time of charging or during the reaction. Acids such as paratoluenesulfonic acid and hydrochloric acid can also be used.

In this reaction system, it is necessary to avoid polymerization of the polymerizable monomer in order to make the reaction proceed in the presence of the polymerizable monomer. For this purpose, a quinone-based or amine-based polymerization inhibitor may be added, or oxygen or air having a polymerization inhibiting action may be blown into the reaction system to cause the reaction to proceed. By the blowing, water generated in the course of the condensation reaction can be distilled out to promote the reaction.

The preferred reaction temperature for proceeding the reaction while inhibiting the polymerization is 50 to 150 ° C., more preferably 70 to 150 ° C.
~ 130 ° C is suitable. The preferred reaction time is 0.5 to 10 hours. Further, the reaction may be performed under reduced pressure in order to promote the distillation of water. The prepolymer synthesized in this way has (meth)
It is produced as a compound containing an acrylate group and an alkyl ether group and / or a methylol group and / or an amino group and / or a methylene group.

The average molecular weight of the prepolymer is preferably set in the range of 200 to 8000 by adjusting the reaction conditions and the amount of distilled water. If it is more than 8,000, the viscosity becomes too high and it is not suitable for use. If it is less than 200, the desired performance cannot be obtained. The prepolymer is considered to be a triazine ring-containing (meth) acrylate prepolymer alone or a mixture of unreacted hydroxyl group-containing (meth) acrylate, and is obtained as a colorless, transparent, viscous liquid. The prepolymer can be used as is,
Purified and used depending on the purpose of use. In addition, a polymerizable monomer such as styrene may be appropriately blended for the purpose of viscosity adjustment or the like, and the curable resin composition may be prepared to be suitable for use.

A compound having an isocyanate group in the molecule is added to the prepolymer synthesized as described above as the fourth component, or the compound is further reacted to obtain a curable composition according to the present invention. Such a compound having an isocyanate group can react with a hydroxyl group, a methylol group, an amino group, a hydroxyl group of an unreacted hydroxyl group-containing (meth) acrylate in the prepolymer, etc., and is useful for improving the performance of a cured resin. Examples of these compounds include isocyanate monomers, adducts, allophanates, burettes, isocyanurates, carbodiimides,
Examples include urethane polymers and blocked isocyanates. The reaction of these compounds proceeds even without a catalyst. However, in consideration of workability and the like, a catalyst such as an amine-based compound or an organometallic compound can be added to accelerate the reaction.

The curable resin composition may be used as it is. However, a polymerizable monomer such as styrene or (meth) acrylic acid ester is appropriately blended and prepared for adjusting viscosity and the like. It may be used as a curable resin composition. Since the curing of the curable resin composition contains an ethylenic unsaturated bond in the molecule, radical polymerization, ionic polymerization and the like are possible, and room temperature, heating, or ultraviolet rays, high energy rays such as electron beams, etc. It can be cured by irradiation. Curing by reaction with the compounded isocyanate group of the fourth component is also possible.

The present inventors have proposed that the curable composition can be made of a ceramic base material such as a calcium silicate plate, a pulp cement plate or a flexible board, a resin plate molded from various resins, a reinforced plastic plate, a melamine decorative plate, a phenol resin. A method of applying the composition to a resin base material such as a board, a surface of a wood board, etc., and irradiating a high energy ray such as an ultraviolet ray or an electron beam to cure the curable resin, or applying the curable resin composition to a resin film or the like. After coating on the sheet-like base material of the above, a high-energy ray such as an ultraviolet ray or an electron beam is irradiated, and a processed sheet obtained by pre-curing the curable resin composition is laminated on the above-described base material and subjected to a heat-pressure treatment. Then, it can be finished by a method of laminating and curing on the surface of the base material. It has been confirmed that high surface properties such as high water resistance, heat resistance, and chemical resistance can be obtained through such treatment, and the present invention according to claims 3 and 4 leads to the present invention. Will be described in the following examples.

Since the surface state of the ceramic base material is not necessarily ensured to be smooth, a sanding treatment may be appropriately performed. In addition, depending on the material, since the resin is porous and the resin excessively penetrates, a urethane resin-based primer for preventing the penetration and improving the adhesion with the coating layer,
A treatment such as an epoxy resin-based primer may be performed.

* Synthesis of triazine ring-containing (meth) acrylate prepolymer In a 2-liter separable flask equipped with a stirrer, a thermometer, a gas injection pipe, and a cooling pipe for purging off fractions, 781 g of 2-hydroxyethyl methacrylate (6 Mol),
126 g (1 mol) of melamine, 189 g of 95% paraformaldehyde (6 mol as formaldehyde), and 0.05 g of hydroquinone monomethyl ether were added and the temperature was raised. After the melamine and paraformaldehyde are dissolved in 2-hydroxyethyl methacrylate, 1.2 g of paratoluenesulfonic acid is added, and while the air is being blown into the reaction solution, the weight of the effluent is kept at 100 ° C. while keeping the temperature at 100 ° C.
The reaction was continued until the amount reached 08 g. The obtained triazine ring-containing methacrylate prepolymer is colorless and transparent and has a viscosity of 1.
It was 3 Pa · S / (20 ° C.).

Example 1 700 g of a triazine ring-containing methacrylate prepolymer prepared as described above, dibutyltin dilaurate 0.
3 g, trimer of hexamethylene diisocyanate having an isocyanurate structure (isocyanate content 21.
(3%) 300 g was charged into a flask provided with a stirrer, and while maintaining the temperature at 30 to 60 ° C., the infrared absorption spectrum of the reaction solution was measured, and the reaction was allowed to proceed until the isocyanate group absorption band at 2275 cm −1 disappeared. The resulting curable resin composition had a colorless and transparent viscosity of 3 Pa. It was a viscous body of s / 60 ° C. To 100 parts by weight of the obtained curable resin composition, 5 parts by weight of titanium oxide was added and mixed to obtain a resin composition for coating. The coating resin composition was coated to a thickness of 50 μm on a surface of a 4 mm-thick cement flexible plate surface-treated with a urethane resin-based primer, and under a nitrogen atmosphere, an acceleration voltage of 150 KV and a dose of 30 μm.
The decorative resin of Example 1 was obtained by irradiating an electron beam under the conditions of KGy to cure the coating resin.

Example 2 After adding and mixing 70 parts by weight of the curable resin composition used in Example 1, 30 parts by weight of a styrene monomer and 0.1 part by weight of an 8% cobalt octylate solution, 25% acetoacetic acid was added. One part by weight of a methyl peroxide solution was added and mixed to obtain a resin composition for impregnation coating. For paper impregnated coating, a titanium paper with a basis weight of 80 g / m2 on which a wood grain pattern is printed is adhered to a 6 mm thick calcium silicate plate treated with a urethane primer with a urethane resin adhesive. The resin composition is impregnated and coated, covered with vinylon film, deaerated with a roll, and the coating thickness is about 50 μm.
Then, the resin composition for impregnation coating was cured, and then the vinylon film was peeled off to obtain a decorative material of Example 2.

Comparative Example 1 A decorative material of Comparative Example 1 was obtained under the same conditions as in Example 1 except that the triazine ring-containing (meth) acrylate prepolymer used in Example 1 was used as it was.

Comparative Example 2 70 parts by weight of the triazine ring-containing methacrylate prepolymer used in Example 1, 30 parts by weight of styrene monomer, and 0.1 part by weight of an 8% cobalt octylate solution were added.
After mixing, 1 part by weight of a 25% methyl acetoacetate peroxide solution was added to obtain a resin composition for impregnated coating. Thereafter, in the same manner as in Example 2, a decorative material of Comparative Example 2 was obtained.

Comparative Example 3 Five core papers impregnated with a resole-based phenol formaldehyde resin in a kraft paper having a basis weight of 180 g / m 2 and 120 g / m 2 were coated on a cellulose paper having a basis weight of 120 g / m 2 with a melamine formaldehyde resin in an amount of 150 g / m 2. One sheet of m2 impregnated top paper is stacked at 150 ° C. and 7.8 MPa (8
A decorative melamine resin plate hot-pressed under the condition of 0 kg / cm2) was used as Comparative Example 3.

Table 1 shows the results of measuring the surface performance of the decorative materials of the examples and comparative examples.

[Table 1] * A slight change refers to "a state in which there is no significant color change or shape change visually."

Test Evaluation Method Pencil Hardness JIS K 5400 Paint General Test Method / 6.
Clause 14 Pencil scratch test. Boiling resistance 40 ° C after 2 hours boiling only on the coated surface
Evaluation is performed by repeating drying 2 hours twice. Cigarette resistance After eradicating tobacco, wipe it off with a cloth and visually observe the appearance. Chemical resistance Evaluated by a method according to JIS K6902. Weather resistance 1000 with sunshine weather meter
It is evaluated by the appearance after the time treatment.

[0026]

The curable resin composition of the present invention comprises a prepolymer in which an aminotriazine compound is bonded to form a hydroxyl group-containing (meth) acrylate via a condensation reaction with a compound having an isocyanate group. Irradiating with high energy rays such as ultraviolet rays, electron beams, heating, etc., compared with those in which a compound having an isocyanate group is not blended or in a non-reacted state, The crosslinking reaction proceeds more quickly, and a cured resin structure having better water resistance, chemical resistance, weather resistance, heat resistance and the like can be formed. For this reason, the curable resin composition is laminated on the base material by means of coating and laminating and cured, whereby a resin film having a high-density crosslinked structure is immediately formed. The cured film of the curable resin has excellent water resistance, chemical resistance, weather resistance, and heat resistance as described above. Can be used with confidence.

Claims (4)

[Claims] 1. A resin containing or reacting a compound having an isocyanate group in a molecule with a triazine ring-containing (meth) acrylate prepolymer synthesized from an aminotriazine compound, formaldehyde and a hydroxyl group-containing (meth) acrylate. A curable resin composition comprising at least a composition. 2. The curable resin composition according to claim 1, wherein the compound having an isocyanate group in the molecule is a compound having an isocyanurate structure. 3. A compound having an isocyanate group in a molecule and a triazine ring-containing (meth) acrylate prepolymer synthesized from an aminotriazine compound, formaldehyde, and a hydroxyl group-containing (meth) acrylate are blended or reacted. A decorative material in which a cured layer of a curable resin composition containing at least a resin composition is finished on a substrate. 4. The cosmetic material according to claim 3, wherein the compound having an isocyanate group is a compound having an isocyanurate structure.