JP3248425B2 - Surface-reinforced decorative paper and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-reinforced decorative paper for decorative boards used for furniture, household equipment and the like, and a method for producing the same. In particular, the present invention has a high surface hardness and excellent durability. The present invention relates to a surface-enhanced decorative paper for a high-grade decorative board, which can reduce production costs and avoid environmental health problems, and a method for producing the same.

[0002]

2. Description of the Related Art As decorative paper for decorative boards laminated on a flat surface of a decorative substrate such as phenol core paper or particle board and used for furniture, housing equipment, etc., conventionally, base paper having good permeability such as titanium paper. After printing on the decorative paper base material,
A resin-impregnated paper made by impregnating a thermosetting resin such as a melamine resin or a diallyl phthalate resin into the decorative paper base material is known, and the resin-impregnated paper is coated on a flat surface of a decorative substrate such as the phenol core paper or particle board. Put on top, and
The decorative plate is manufactured by heating and compressing through a mirror surface plate. And the decorative board obtained by such a method has necessary surface hardness and abrasion resistance, but on the other hand, it has to be expensive because of poor production efficiency.

[0003] In order to improve the production cost, various methods have recently been studied in which an electron beam-curable resin formulated as a solvent-free resin is used instead of a thermosetting resin such as a melamine resin. However, in reality, satisfactory results have not been obtained for the following reasons.

[0004] First, oil-based inks have conventionally been used as inks for applying printed patterns to the decorative paper base material. However, in recent years, problems such as the use of solvents and influence on the global environment have been emphasized in recent years. Therefore, water-based inks free of such problems are becoming mainstream.

When an aqueous ink is used in place of the oil-based ink, a solventless electron beam-curable resin is applied from the surface of the decorative paper base on which the printed pattern is applied, and the electron beam is irradiated in the same process. If you try to do it in a short time, the polarity of the water-based ink is high, so that penetration of the electron beam-curable resin is easily hindered,
There is a disadvantage that the electron beam curable resin is cured before the electron beam curable resin sufficiently penetrates into the interior of the decorative paper base material.

For this reason, the adhesion between the electron beam-curable resin layer and the aqueous ink layer is small, and the curing of the electron beam-curable resin layer also acts to cure, so that the electron beam-curable resin is easily separated from the surface of the ink layer. There was a problem.

[0007] Further, the active energy ray-curable solventless paints and inks utilizing the energy of electron beams and ultraviolet rays for curing the resin as described above are generally compared with the above-mentioned thermosetting type. The advantages such as energy saving, high productivity and low temperature curing are emphasized. However, the active energy ray-curable solventless resin composition used here,
Generally, a 100% liquid type or organic solvent solution type resin composition comprising an oligomer (or a prepolymer) and a monomer as main components and further adding a photopolymerization initiator and a sensitizer in photocuring is applied. However, the use of low-molecular-weight vinyl monomers for viscosity control and solvents added to facilitate coating workability deteriorates the work environment due to the odor, and the danger of fire due to ignition of monomers and solvents, toxicity, etc. There were many safety and health problems. Further, in the case of a 100% liquid type, there is a drawback that the addition of the monomer impairs the physical properties of the originally intended oligomer. For this reason, there is a demand for development of a surface-reinforced decorative paper to which a water-based ultraviolet or electron beam-curable resin composition which does not require a monomer or a solvent and has no problem is applied.

Further, the surface protective coating agent applied to the surface of the decorative paper base material is required to have a good balance between surface design and physical properties. An extender pigment such as inorganic filler particles is generally added to make the surface gloss matte, but this extender pigment also contributes to the improvement of physical properties such as abrasion resistance in addition to the above matte effect. are doing. However, depending on the product, a product having a high surface gloss (that is, a low matte feeling) and excellent physical properties such as abrasion resistance may be required. In such a case, since it is difficult to add a large amount of extender pigment to the surface protective coating agent, it is necessary to satisfy physical properties only by the resin component which is a main component of the surface protective coating agent.

However, even when the degree of cross-linking of the organic resin is increased, when compared at the same film thickness, it generally does not reach the physical properties of the coating film to which the inorganic substance is added. It was difficult to satisfy both physical properties such as abrasion resistance.

That is, there has been a problem that it is difficult to simultaneously satisfy the surface design property and the high coating film physical properties with only one surface protective coating layer.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and has as its object to provide a hardness and abrasion resistance which can be used for furniture, housing equipment and the like. Another object of the present invention is to provide a surface-enhanced decorative paper for a high-grade decorative board, which can reduce production costs and avoid environmental health problems, and a method for producing the same.

[0012]

That is, the invention according to claim 1 is based on a decorative paper base on which a printed pattern is formed with a water-based ink, based on a surface-reinforced decorative paper for a decorative board laminated on a decorative substrate. And an active energy ray-curable aqueous resin composition mainly composed of an aqueous emulsion resin provided on the printing surface of the decorative paper substrate and having no tackiness after thermal drying. A first protective layer and a second protective layer provided on the first protective layer and formed of an active energy ray-curable aqueous resin composition not containing the aqueous emulsion resin , wherein the active energy
One component of the radiation-curable aqueous resin composition is ultraviolet ray or electron beam hardening.
Made of modified polymers, oligomers or monomers
Fat, and at least one of the following components
Bifunctional or higher functional urethane acryle represented by general formula (I)
Contain methacrylate or urethane methacrylate.
It is characterized by the following.

[0013]

Embedded image R: hydrogen atom or methyl group X: isocyanate residue Y: dihydric alcohol residue

[0014] Then, according to the surface enhancement decorative paper according to the invention of claim 1, wherein said first protective layer and the active energy ray curable aqueous resin composition of the second protective layer has excellent affinity for aqueous ink , The adhesion between each protective layer and the aqueous ink layer is improved, and the active energy ray-curable aqueous resin composition is applied to the interior of the decorative paper base by a heat drying process before the active energy ray curing. Since the object penetrates, it becomes possible to provide hardness and wear resistance that can be used for furniture, household equipment, and the like.

Further, since the first protective layer is composed of an active energy ray-curable aqueous resin composition mainly composed of an aqueous emulsion resin prepared so as not to have tackiness after heat drying, the first protective layer is formed after heat drying. Has low re-solubility in water. Therefore, when the active energy ray-curable aqueous resin composition containing no aqueous emulsion resin is applied in the subsequent step to provide the second protective layer, recoatability can be ensured.

Furthermore, extender pigments such as the first protective layer made of an active energy ray curable aqueous resin composition composed mainly of the aqueous emulsion resin filler in the wear resistance by adding a high concentration By providing physical properties, the second protective layer composed of the active energy ray-curable aqueous resin composition not containing an aqueous emulsion resin is provided with its design without adding a filler, thereby protecting the surface. It is also possible to simultaneously satisfy the surface design and the advanced coating film properties, which were difficult to achieve with only one coating layer.

When a bifunctional or more functional urethane acrylate or urethane methacrylate is blended in the active energy ray-curable aqueous resin composition, the urethane acrylate or urethane methacrylate reacts with other polymerizable resin composition components and has an excellent resistance. Solvent resistance, water resistance, acid resistance,
It is possible to form a protective layer having an excellent balance of physical properties such as alkali resistance and film strength. The invention according to claim 1 has been made for such a technical reason.

That is, the invention according to claim 1 has already been described.
As a solid , one component of the active energy ray-curable aqueous resin composition is composed of a resin composed of ultraviolet or electron beam-curable polymer, oligomer or monomer, and
As a feature together also to contain two or more functional groups of urethane acrylates or urethane methacrylates represented by the above general formula (I) in at least one component
I have .

According to the surface-enhanced decorative paper according to the first aspect of the present invention, the active energy ray-curable aqueous resin composition has the acryloyl group or methacryloyl group at both ends in the general formula (I). Since a bifunctional or more urethane acrylate or urethane methacrylate as shown is contained, after the coating film of the active energy ray-curable aqueous resin composition for the first and second protective layers is formed, ultraviolet rays, electron beams, etc. By irradiating the active energy ray of the above, bifunctional or higher functional urethane acrylate or urethane methacrylate reacts with other polymerizable resin composition components to act as one component of a crosslinking agent, and has solvent resistance, water resistance, acid resistance, It is possible to form each protective layer excellent in physical properties such as alkalinity and film strength, and in the final protective layer coating film Reaction components nor remain.

The dihydric alcohol residue of the bifunctional or higher-functional urethane acrylate or urethane methacrylate represented by the above general formula (I) is converted to ethylene oxide (E
O) and a compound selected from ether-based polyols having a structure of propylene oxide (PO) as a raw material, and further, a composition per each repeating unit structure of ethylene oxide and propylene oxide constituting the dihydric alcohol residue By setting the ratio (molar ratio) in an appropriate range, the hydrophilicity / hydrophobicity of urethane acrylate or urethane methacrylate can be balanced, so that emulsifying ability with respect to other resin composition components is provided, and the oil-soluble compound is originally used. Can be effectively dispersed in water with other active energy ray-curable oligomers, monomers and the like, which are overwhelmingly different. Thereby, since the urethane acrylate or urethane methacrylate itself acting as an emulsifier also acts as a crosslinking agent, it is possible to form a protective layer having an excellent balance of physical properties such as solvent resistance, water resistance, acid resistance, alkali resistance, and film strength. Becomes The inventions according to claims 2 and 3 have been made for such technical reasons.

In other words, the invention according to claim 2 is
Assuming the surface-reinforced decorative paper according to the invention as described in 1, the dihydric alcohol residue of bifunctional or more urethane acrylate or urethane methacrylate represented by the general formula (I) has a structure of ethylene oxide and propylene oxide. The invention according to claim 3 is characterized by comprising a compound selected from ether-based polyols as a raw material. The surface-reinforced decorative paper according to claim 2 is premised on the general formula (I) The composition ratio (molar ratio) per each repeating unit structure of ethylene oxide and propylene oxide constituting the dihydric alcohol residue of bifunctional or higher functional urethane acrylate or urethane methacrylate represented by
It is characterized in that it is set in the range of 9: 1 to 4: 6.

Next, the invention according to Claims 4 to 6 is Claim 1
The present invention relates to an invention that specifies a method for producing a surface-reinforced decorative paper according to the described invention.

In other words, the invention according to claim 4 is based on the method for producing a surface-reinforced decorative paper according to claim 1, and includes the steps of:
An active energy ray-curable aqueous resin composition containing an aqueous emulsion resin as a main component prepared so as not to have tackiness after thermal drying is applied to form a first protective layer, and on this first protective layer The active energy ray-curable aqueous resin composition not containing the aqueous emulsion resin is applied to form a second protective layer, and after each protective layer is thermally dried, is irradiated with ultraviolet rays or electron beams. A method for producing a surface-reinforced decorative paper in which the first protective layer and the second protective layer are simultaneously cured.
To form an active energy ray-curable aqueous resin composition
UV or electron beam curable polymer or oligomer
Or a resin composed of a monomer
At least one component is a bifunctional compound represented by the following general formula (I)
Urethane acrylate or urethane methacrylate
It is characterized by containing a rate,

[0024]

Embedded image R: hydrogen atom or methyl group X: isocyanate residue Y: dihydric alcohol residue

The invention according to claim 5 is based on the method for producing a surface-reinforced decorative paper according to claim 4 , and is based on the general formula (I).
Characterized in that the dihydric alcohol residue of bifunctional or higher urethane acrylate or urethane methacrylate represented by is composed of a compound selected from ether polyols having a structure of ethylene oxide and propylene oxide as a raw material, The invention according to claim 6 is based on the method for producing a surface-reinforced decorative paper according to claim 5 , and is based on the dihydric alcohol residue of bifunctional or higher-functional urethane acrylate or urethane methacrylate represented by the general formula (I). The composition ratio (molar ratio) of ethylene oxide and propylene oxide constituting each group per repeating unit structure is 9: 1.
~ 4: 6.

[0026]

Embodiments of the present invention will be described below in detail.

It should be noted, firstly describes constituent materials of the surface enhancement decorative paper, then, the production method of the active energy ray curable aqueous resin composition applied as a surface protective layer of the decorative paper is described in detail.

Firstly, as a decorative paper base material constituting the part of the surface reinforcing decorative paper according to the present invention, basis weight 30 to 120 g /
m ² decorative paper base paper is preferred. Base paper for decorative paper which has been subjected to a sealer treatment or the like with a urethane resin or a vinyl resin in advance may be applied. This is printed with an aqueous ink or the entire surface is colored. The printing method may be a known method such as a gravure printing method. The method of applying the first and second protective layers is optional, but in the production stage, a roll coater, a reverse roll coater, a gravure coater, a knife coater or the like is generally used.

Next, a method for manufacturing the above-described active energy ray curable aqueous resin composition is a component of the first protective layer and the second protective layer.

[0030] First, as the diisocyanate compound for introducing a polyurethane diol components in bi- or more-functional urethane acrylates or urethane methacrylates represented by the general formula (I), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI ), Diphenylmethane diisocyanate (MD
I), aromatic diisocyanates represented by naphthylene diisocyanate (NDI), lysine diisocyanate methyl ester (LDIM), trimethylhexamethylene diisocyanate (TMDI), dimer acid diisocyanate (DDI), hexamethylene diisocyanate, methylcyclohexylene Aliphatic diisocyanates such as -2,4 (2,6) -diisocyanate, 1,3 (4)-(diisocyanatomethyl) cyclohexane, 4,4-bis (isocyanatocyclohexyl) methane and isophorone diisocyanate can be used. .

As the polyol substance for introducing the polyurethane diol component, ethylene glycol, propylene glycol, diethylene glycol,
Low molecular weight polyols such as dipropylene glycol, oligomer polyols such as polyoxyethylene glycol and polyoxypropylene glycol, and, if necessary, random or block polyethers of ethylene oxide and propylene oxide can also be used.

Next, combining two or more functional urethane acrylates or urethane methacrylates represented by the above general formula (I) by introducing an acrylate or methacrylate at both ends of the polyurethane diols obtained by a diisocyanate compound and polyol materials Examples of the materials for this purpose include bifunctional monomers having a methacryloyl group and an isocyanate group in one molecule, ie, m-isopropenyl-α, α-dimethylbenzyl isocyanate (m-TMI), and 2-methacryloyloxyethyl isocyanate (MOI). ) Etc. are available. In addition to the various diisocyanate compounds exemplified above, an isocyanate group and an acryloyl or methacryloyl group and an active hydrogen group such as a hydroxyl group, a carboxyl group, an amine and an amide in an isocyanate group and a molecule of an arbitrary difunctional or higher polyfunctional polyisocyanate compound, respectively. Compounds having at least one or more isocyanate groups and one or more acryloyl or methacryloyl groups in one molecule obtained by reacting an active hydrogen group of one or more compounds can be used. An acryloyl or methacryloyl group and a hydroxyl group in the molecule required for synthesizing this compound,
As the compound having at least one active hydrogen group such as a carboxyl group, an amine, or an amide, various types and various grades are commercially available. Typically, for example, acrylic acid-2 as an anionic monomer
-Hydroxyethyl, hydroxypropyl acrylate,
Examples include 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, methacrylic acid, itaconic acid, crotonic acid, and arbitrary oligomers having these compounds as copolymerization components. Examples of the cationic monomer include aminoalkyl acrylate and aminoalkyl methacrylate, acrylamide, N-methylolacrylamide,
Dimethylaminopropyl (meth) acrylamide, N-
Amide monomers such as isopropylacrylamide are exemplified.

As another component of the active energy ray-curable aqueous resin composition containing the bifunctional or higher functional urethane acrylate or urethane methacrylate represented by the general formula (I), a general polyester-based resin is used. And polymerizable prepolymers represented by acrylates such as polyepoxy, polyurethane, polyether, and polyacrylic. If necessary, monofunctional and polyfunctional acrylates or methacrylates having low odor and skin irritation may be added.

When the active energy rays in the active energy ray-curable aqueous resin composition are ultraviolet rays, it is necessary to add a photosensitizer (radical polymerization initiator) to the composition. Examples of such additives include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether,
Benzoin such as benzyl methyl ketal and its alkyl ethers; acetophenone, 2,2-dimethoxy-
Acetophenones such as 2-phenylacetophenone and 1-hydroxycyclohexylphenyl ketone; anthraquinones such as methylanthraquinone, 2-ethylanthraquinone and 2-amylanthraquinone; thioxanthone, 2,4-diethylthioxanthone and 2,4-diisopropylthioxanthone Thioxanthones; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone and 4,4-bismethylaminobenzophenone; and azo compounds. These can be used alone or 2
Tertiary amines such as triethanolamine and methyldiethanolamine; photoinitiating aids such as benzoic acid derivatives such as 2-dimethylaminoethylbenzoic acid and ethyl 4-dimethylaminobenzoate; It can also be used in combination with. The amount of the organic peroxide or photopolymerization initiator used is 0.5 to 20 parts by weight, preferably 1 to 15 parts by weight, based on 100 parts by weight of the polymerizable component of the active energy ray-curable aqueous resin composition. .

[0035] While the main constituent material of the surface enhancement decorative paper according to the present invention has been described, it will be specifically described below a method of manufacturing the active energy ray curable aqueous resin composition.

Firstly, the general formula for the synthesis of di- or higher functional urethane acrylates or urethane methacrylates represented by (I), any respectively difunctional polyisocyanates ethylene oxide (EO) and propylene oxide (PO) Choose a polyether diol with a structure,
According to a conventional method, these are formulated in a suitable solvent so that the ratio of isocyanate groups to hydroxyl groups becomes approximately equimolar, and they are reacted. In this case, it is preferable to formulate the composition so that the composition ratio (molar ratio) of EO and PO is in the range of 9: 1 to 4: 6.

In order to convert the hydroxyl groups at both ends of the obtained polyurethane diol into acryloyl groups or methacryloyl groups, (1) m-isopropenyl-α which is a bifunctional monomer having a methacryloyl group and an isocyanate group in one molecule. Or a compound such as α-dimethylbenzyl isocyanate (m-TMI), 2-methacryloyloxyethyl isocyanate (MOI), or (2)
An isocyanate group of an arbitrary difunctional or higher polyfunctional polyisocyanate compound is reacted with an active hydrogen group of a compound having an acryloyl or methacryloyl group and at least one active hydrogen group such as a hydroxyl group, a carboxyl group, an amine or an amide in a molecule. A compound having at least one or more isocyanate groups and one or more acryloyl or methacryloyl groups in one molecule obtained by reacting 2 moles of the compound with respect to 1 mole of the polyurethane diol, thereby obtaining a bifunctional or more functional urethane acrylate. Alternatively, urethane methacrylate is obtained.

[0038] Then, as essential components the resulting urethane acrylate or urethane methacrylate by the method described above, this and general polymerizable prepolymers, optionally, odor and low skin irritation monofunctional and multifunctional An active energy ray-curable aqueous resin composition is obtained by blending an acrylate or methacrylate monomer and forcibly emulsifying and dispersing the composition in water. In this case, the bifunctional or higher functional urethane acrylate or urethane methacrylate prepolymer represented by the general formula (I) acts as an emulsifier. When ultraviolet rays are used as the active energy rays, it is preferable that the oil-soluble photopolymerization initiator is added to the resin composition before or after emulsification, and that the water-soluble photopolymerization initiator is added after the emulsification.

The emulsification method conforms to a general forced emulsification method.
For example, (1) water is added after mixing all the resin components, and if necessary, a heating operation or a resin solvent is added,
Disperse strongly with a homomixer or the like. After the dispersion, cooling, removal of the solvent, and the like are performed. (2) First, after dissolving or dispersing urethane acrylate or urethane methacrylate represented by the above general formula (I) acting as an emulsifier in water, the remaining resin composition is gradually added while performing strong stirring. . (3) It can be produced by a general phase inversion emulsification method or the like.

In this manner, an active energy ray-curable aqueous resin composition for the second protective layer is obtained. When this active energy ray-curable aqueous resin composition is used as a constituent material of the first protective layer, Is a general-purpose aqueous resin such as an acrylic resin emulsion, a polystyrene resin emulsion, or a vinyl acetate resin emulsion in order to have no tackiness after heat drying (that is, to be tack-free). Aqueous dispersion of vinyl polymer emulsion such as vinylidene chloride resin emulsion, vinyl chloride resin emulsion, synthetic rubber resin emulsion such as SB resin emulsion, NB resin emulsion, urethane resin emulsion, acrylic urethane resin emulsion, etc. Mold resin must be added as an anti-blocking agent. It is. Also, polyvinyl alcohol, carboxymethylcellulose, methylcellulose,
Water-soluble resins such as hydroxyethylcellulose, polyacrylic acid, casein, gelatin, starch, polyvinylpyrrolidone, polyacrylamide and derivatives thereof can also be used within the necessary range as additives for adjusting coating liquid properties such as thickeners. it can. Further, a commercially available active energy ray-curable aqueous resin can also be mixed and used.

[0041] Further, in the above-mentioned active energy ray curable aqueous resin composition, for the various functions to be imparted to the protective layer,
If necessary, colorants, extenders, lubricants, plasticizers, stabilizers, flame retardants, defoamers, antioxidants, bactericides, conductive materials,
Additives such as magnetic materials can also be included.

[0042]

Embodiments of the present invention will be specifically described below.

Incidentally, parts and percentages are all by weight unless otherwise specified.

Example 1 "Synthesis of an active energy ray-curable aqueous resin composition" Step 1 250 parts of 2-butanone and 100 parts of toluene were placed in a glass reaction vessel equipped with a calcium chloride tube, and 254 parts of diphenylmethane diisocyanate was added. Was charged in the mixed solvent, and a mixed solution of 75 parts of diethylene glycol and 40 parts of dipropylene glycol was added dropwise over about 2 hours.
A time reaction was performed.

At the final stage of the reaction, 5 parts of dipropyl alcohol was added dropwise to terminate the reaction. Further, 0.2 part of hydroquinone was added, and the structures of ethylene oxide and propylene oxide were randomly incorporated at a ratio of about 7/3. A polyurethane diol was obtained.

[0046] Step 2 Next, 2 polyurethane diol solution obtained in step 1
-60 parts of methacryloyloxyethyl isocyanate was added and reacted at 60 ° C, and then the solvent was removed to obtain a bifunctional urethane methacrylate prepolymer. The disappearance of the absorption due to the isocyanate group was confirmed by IR spectrum measurement.

[0047] Step 3 2 50 parts urethane methacrylate prepolymer functional obtained in step 2 was dispersed in distilled water 465 parts in passing through the ion exchange treatment, the temperature was maintained at 50 ° C.. A prepolymer composition comprising a light- or electron-beam-curable oligomer and a monomer having the following formulation was added to this aqueous dispersion little by little while sufficiently dispersing with a homomixer.

[0048] Incidentally, the prepolymer composition having the following formulation is 50
The mixture was heated to ° C. and charged with the viscosity lowered. After completion of the charging, stirring with a homomixer was continued at a rotation speed of 6000 rpm for 10 minutes to obtain a milky white uniform ultraviolet-curable aqueous resin composition.

[0049] 6-functional urethane acrylate oligomer (Actilane 110, AKCROS CHEMICALS Co., Ltd.) 160 parts of PO, ECH-modified bisphenol A diacrylate (Epoxy Ester 3002A, manufactured by Kyoeisha Chemical Co., Ltd.) 40 parts Darocure 1173 (Ciba-Geigy) 7.5 parts

[0050] Step 4 Step 3 obtained in UV curable aqueous resin composition (hereinafter,
Aqueous UV emulsion) was used as the first and second protective layers according to the following formulation.

[0051] (First ultraviolet curing protective layer and water-based coating agent) aqueous UV Emulsion 300 parts of acrylic urethane resin emulsion (NeoPac R-9000: Zeneca Corp.) 320 parts commercial ultraviolet-curable aqueous resin (NeoRad NR-440: 160 parts Silica powder (Mizukasil P-510: manufactured by Mizusawa Chemical Co., Ltd.) 20 parts Colloidal silica (Cataloid SI-30: manufactured by Catalyst Kasei Kogyo Co., Ltd.) 200 parts Silica was dispersed by the homomixer used in step 2. A coating consisting of a milky white stable suspension was obtained.

[0052] (Second protective layer for an ultraviolet curable aqueous coating agent) water UV Emulsion 420 parts polyether modified silicone (Kp-341: manufactured by Shin-Etsu Chemical Co., Ltd.) 3.5 parts water-soluble photopolymerization initiator (Irgacure 2959: 4 parts Coating composition consisting of a milky white stable suspension similar to the UV-curable aqueous coating composition for the first protective layer was obtained.

[Preparation of surface-enhanced decorative paper and decorative board ] An oak-like woodgrain pattern is printed on a decorative paper base material having a basis weight of 60 g / m ² using an aqueous ink (manufactured by Toyo Ink Mfg. Co., Ltd.). First, a UV-curable aqueous coating agent for the first protective layer is applied on the ink layer of the material with a wire bar so as to have a coating amount of about 8 g / m ² , and is then heated in an oven at 75 ° C for 2 minutes
Drying was performed.

Next, the second ultraviolet curing protective layer and water-based coating agent was applied so that the coating weight of about 7 g / m ² on the first protective layer surface after the heat drying, same as the first protective layer Thermal drying was performed under the conditions.

[0055] After that, when cured the first and second protective layer coating film by irradiation of ultraviolet light of the integrated light quantity 300 mJ / cm ² from the second protective layer surface by 80W / cm high-pressure mercury lamp, the surface gloss , A hard and tough film was obtained.

The decorative paper thus obtained was adhered to a particle board with a urea / vinyl acetate adhesive to form a decorative board, which was observed. The scratch resistance was also good.

[0057] <Evaluation of the decorative plate> the performance of the resulting decorative plate by the above method was evaluated by the following method.

1) Solvent resistance: Rubbing was performed under a load of 500 g / cm ² while 2-butanone was dropped on the surface of the decorative sheet sample, and damage to the coating film surface by the solvent was observed.

[0059] Then, to measure the number of rubbing up damage of the coating film surface is confirmed.

[0060] 2) Resistance to cellophane tape resistance: print plywood
Based on the standard of color plywood standard (Japan Print Plywood / Color Plywood Industry Association), peeling (40 ° C. ± 3 ° C., after 2 hours) with Nichiban CelloTape (trademark) was performed, and the surface condition was observed. .

[0061] 3) Abrasion resistance: according to the standard of JAS wear B testing, load wound sandpaper to rubber abrasion ring 5
Abrasion test was conducted under the condition of 00g, and the printed pattern was 5
The case where 0% or more disappeared was judged as reject, and the case where it was 50% or less was judged as passed.

[0062] 4) Stain resistance: according to the standard of JAS contamination A test, oil-based ink, to form a line of 10mm width on the surface of the coating film of the decorative plate with an aqueous ink and crayon, after 4 hours left standing, wiped with methanol And the state of contamination was observed.

[0063] 5) Water resistance: at room temperature the coating strips was immersed in water for three days, it was evaluated whitening degree of the film was visually observed.

[0064] 6) Acid resistance: was added dropwise to acetic acid (5% aqueous solution) on the coating film and covered with a watch glass and evaluated the surface condition after 6 hours was visually observed.

[0065] 7) Alkali resistance: was added dropwise to sodium carbonate (1% aqueous solution) on the coating film and covered with a watch glass and evaluated the surface condition after 6 hours was visually observed.

The results of each characteristic test are shown in Table 1 below.

[0067] [Example 2] Example first protective layer and the active energy ray curable for the second protective layer obtained in 1 aqueous coating agent photopolymerization initiator (Darocure 1173, Irgacure 2959) was added First, the first and second protective layer coatings were formed on the aqueous ink layer of the decorative paper base under the same method and conditions as in Example 1, and after heat drying, an acceleration voltage of 200 keV was applied from the coating side. The coating film was cured by irradiating an electron beam under the conditions of an absorption dose of 4 Mrad.

As in Example 1, a hard coating film having excellent surface gloss was obtained. Table 1 shows the evaluation results.

[0069] [Comparative Example 1] except for using an electron beam-curable coating composition of solventless the following composition was produced decorative paper in the same manner as in Example 1, a cured coating film of Example 2 A decorative plate was produced by performing the same electron beam. Table 1 shows the evaluation results.

[0070] 6-functional urethane acrylate oligomer (ART RESIN UN-3320HC, Negami Chemical Industrial Co., Ltd.) 50 parts EO-modified bisphenol A diacrylate (BP-4EA, Kyoeisha Chemical Co., Ltd.) 125 parts of tripropylene glycol diacrylate 120 parts polyether-modified 3.5 parts of silicone (Kp-341: manufactured by Shin-Etsu Chemical Co., Ltd.)

[0071]

[Table 1]

[ Evaluation Results ] As shown in Table 1, when the decorative paper according to each example was applied, cellophane tape resistance and abrasion resistance were higher than when the decorative paper according to the comparative example was applied. It is confirmed that has been improved.

[0073]

According to the surface-enhanced decorative paper according to the first aspect of the present invention, the first protective layer and the second protective layer are formed into an active energy ray-curable aqueous resin composition having excellent affinity for aqueous ink. The adhesive strength between each protective layer and the aqueous ink layer is improved, and the active energy ray-curable aqueous resin composition is applied to the interior of the decorative paper substrate by a heat drying process before the active energy ray curing. It has the effect of being able to provide hardness and abrasion resistance that can be used for furniture, household equipment, and the like due to penetration.

Since the first protective layer is composed of an active energy ray-curable aqueous resin composition mainly composed of an aqueous emulsion resin prepared so as not to have tackiness after heat drying, the first protective layer is formed after heat drying. Has low re-solubility in water.

[0075] Thus, the effect of making it possible to ensure the re-coating property in providing the second protective layer by coating an active energy ray curable aqueous resin composition which does not contain an aqueous emulsion resin in a later step Have.

[0076] Furthermore, extender pigments such as the first protective layer made of an active energy ray curable aqueous resin composition composed mainly of the aqueous emulsion resin filler in the wear resistance by adding a high concentration By providing physical properties, the second protective layer composed of the active energy ray-curable aqueous resin composition not containing an aqueous emulsion resin is provided with its design without adding a filler, thereby protecting the surface. This has the effect that it is possible to simultaneously satisfy the surface design properties and the advanced coating film properties, which were difficult to achieve with only one coating layer.

[0077] Furthermore, it contains 2 or more functional urethane acrylates or urethane methacrylates represented by the above general formula with an acryloyl group or a methacryloyl group at both ends to the active energy ray curable aqueous resin composition in (I) Therefore, after the coating film of the active energy ray-curable aqueous resin composition for the first and second protective layers is formed, ultraviolet rays, by irradiating active energy rays such as electron beams, to act as an emulsifier. Bifunctional or more urethane acrylate or urethane methacrylate having reacts with other polymerizable resin composition components to act as a component of the crosslinking agent, solvent resistance, water resistance, acid resistance, alkali resistance,
Each protective layer having an excellent balance of physical properties such as film strength can be formed, and an unreacted component hardly remains in the final protective layer coating film.

Further , according to the surface-reinforced decorative paper according to the second aspect of the present invention, the dihydric alcohol residue of the bifunctional or higher-functional urethane acrylate or urethane methacrylate represented by the general formula (I) is ethylene oxide. And a compound selected from ether-based polyols having a structure of propylene oxide.
According to the surface-enhanced decorative paper according to the invention described in Item 3 , each of ethylene oxide and propylene oxide constituting a dihydric alcohol residue of bifunctional or higher-functional urethane acrylate or urethane methacrylate represented by the general formula (I) is repeated. The composition ratio (molar ratio) per unit structure is 9: 1 to 4:
6, the hydrophilicity / hydrophobicity of the urethane acrylate or urethane methacrylate can be balanced, so that emulsifying ability for other resin composition components is imparted, whereby solvent resistance, water resistance,
This has the effect of forming an excellent protective layer due to the balance of physical properties such as acid resistance, alkali resistance and film strength.

Next, according to the method for producing a surface-reinforced decorative paper according to the invention of the fourth to sixth aspects, the surface-reinforced decorative paper according to the first to third aspects can be reliably produced, and the first protective layer and the first protective layer can be formed. The active energy ray-curable aqueous resin composition for forming the second protective layer uses water instead of a volatile vinyl monomer or an organic solvent as a diluting component, and generates ammonia, amine, and the like upon drying. Because there is no, there is no environmental health problem, furthermore, since the active energy ray-curable aqueous resin composition is basically a one-part type,
After use, the surplus coating liquid can be reused, which is economical, and has the effect of significantly reducing capital investment and the like for preventing air pollution.

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 D21H 11/00-27/42

Claims (6)

(57) [Claims] 1. A surface-reinforced decorative paper for a decorative board laminated on a decorative substrate, comprising: a decorative paper substrate provided with a printed pattern with an aqueous ink; and a decorative paper substrate provided on the printing surface of the decorative paper substrate; A first protective layer composed of an active energy ray-curable aqueous resin composition containing an aqueous emulsion resin as a main component prepared so as not to have tackiness after heat drying, and provided on the first protective layer; and A second protective layer made of an active energy ray-curable aqueous resin composition containing no aqueous emulsion resin , wherein the active energy ray-curable aqueous resin set is provided.
One component of the product is an ultraviolet or electron beam curable polymer,
Composed of a resin consisting of sesame or monomer,
And at least one component represented by the following general formula (I)
Bifunctional or higher urethane acrylate or urethane
Surface-enhanced decorative paper containing methacrylate . Embedded image R: hydrogen atom or methyl group X: isocyanate residue Y: dihydric alcohol residue 2. A compound in which the dihydric alcohol residue of bifunctional or higher functional urethane acrylate or urethane methacrylate represented by the general formula (I) is selected from ether polyols having a structure of ethylene oxide and propylene oxide. surface enhancement decorative paper according to claim 1, characterized in that it is configured as a raw material. 3. A composition ratio (molar ratio) of ethylene oxide and propylene oxide constituting a dihydric alcohol residue of bifunctional or higher functional urethane acrylate or urethane methacrylate represented by the general formula (I) per each repeating unit structure. ) is 9: 1 to 4: 6 surface enhancement decorative paper according to claim 2, characterized in that it is set in the range of. 4. The method for producing a surface-reinforced decorative paper according to claim 1, wherein the decorative paper is prepared so that it does not have tackiness after heat drying on a printing surface of a decorative paper substrate on which a print pattern with an aqueous ink has been applied. An active energy ray-curable aqueous resin composition containing a water-based emulsion resin as a main component is applied to form a first protective layer, and the active energy ray-curable composition does not contain the aqueous emulsion resin on the first protective layer. Forming a second protective layer by coating the mold aqueous resin composition, and, after heat-drying each protective layer, irradiating an ultraviolet ray or an electron beam to the first protective layer and the second protective layer. A method of manufacturing surface-reinforced decorative paper that is cured at the same time
There is one component of the active energy ray-curable aqueous resin composition
UV or electron beam curable polymer, oligomer or
It is composed of a resin consisting of a monomer, and at least
Both of which have two or more functional groups represented by the following general formula (I)
Urethane acrylate or urethane methacrylate
A method for producing a surface-reinforced decorative paper, comprising: Embedded image R: hydrogen atom or methyl group X: isocyanate residue Y: dihydric alcohol residue 5. A compound in which the dihydric alcohol residue of bifunctional or higher-functional urethane acrylate or urethane methacrylate represented by the general formula (I) is selected from ether polyols having a structure of ethylene oxide and propylene oxide. The method for producing a surface-reinforced decorative paper according to claim 4, wherein the method is constituted as a raw material. 6. A composition ratio (molar ratio) of each of the repeating units of ethylene oxide and propylene oxide constituting the dihydric alcohol residue of bifunctional or higher functional urethane acrylate or urethane methacrylate represented by the above general formula (I). 6. The method for producing a surface-reinforced decorative paper according to claim 5 , wherein the value of) is set in the range of 9: 1 to 4: 6.