JP3424140B2 - Pre-coated paper with scratch resistance - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to precoated paper used as a surface material for furniture and building materials, and more particularly to precoated paper having scratch resistance.

[0002]

2. Description of the Related Art As a decorative paper used for interior decoration of buildings, finishing of furniture, and surface decoration of other articles, conventionally,
After printing on the base paper for decorative paper made of thin paper or inter-paper reinforced paper, a so-called precoated paper having a topcoat layer for surface protection formed on the printed surface is used, and as the topcoat layer, A transparent ink using a melamine resin or a polyurethane resin as a vehicle is used. Such pre-coated paper is used as a so-called decorative board by being attached to a predetermined wood base material such as particle board with an adhesive and then subjected to hot press molding.

However, in the above-mentioned conventional pre-coated paper, when a melamine resin is used as the top coat layer, it is excellent in performance such as scratch resistance and oil resistance, but it is attached to a wood base material. The heat press time for wearing is long (about 6
(0 second / time), and the pre-coated paper after applying the melamine-based resin has a pot life, which makes it difficult to make a long-term stock, resulting in poor productivity and high cost.

Therefore, the applicant of the present invention has previously proposed Japanese Patent Application Laid-Open No. 4-23 as a decorative sheet for solving the above-mentioned drawbacks.
A precoated paper using a polyurethane-based resin as described in Japanese Patent No. 8027 has been proposed. According to this method, the heat pressing time for sticking to the wood base material is about 12 seconds /
The number of times was shortened, the productivity was excellent without the pot life of pre-coated paper, and the performance such as oil resistance was solved, but as a new problem, silica pigment as a matting agent to make the top coat layer low gloss When used, there was a problem that scratch resistance was not good.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a precoated paper having good productivity, low gloss and scratch resistance. To provide.

[0006]

The precoated paper having scratch resistance of the present invention for achieving the above object is a solid printing layer having a two-component curable urethane resin as a vehicle on the surface of a base paper for decorative paper. In a pre-coated paper in which a top coat layer and a top coat layer are sequentially laminated, the top coat layer is composed of a transparent ink layer of a two-component curable urethane resin containing a silica pigment, and is formed on the solid printing layer. A second top coat layer formed on the first top coat layer, which comprises a coat layer and a transparent ink layer of a two-component curable urethane resin containing elastic spherical resin beads as a matting agent and a melamine resin. It is characterized by being composed of layers.

It is preferable that the elastic spherical resin beads are made of acrylic resin and have an average particle diameter of 2 to 20 μm.

Omission

[0009]

In the present invention, the topcoat layer contains a transparent ink layer containing a silica pigment (hereinafter referred to as the first topcoat layer) and a transparent ink layer containing elastic spherical resin beads as a matting agent (hereinafter referred to as the second topcoat layer). Since it is provided as two layers (referred to as a coat layer), the first top coat layer prevents uneven penetration of the second top coat layer and plays a role of lowering the gloss of the surface. Furthermore, the second top coat layer is formed of a two-component curing type urethane resin and melamine resin, and the elastic spherical resin beads are made of acrylic resin of 2 to 20 μm, so that the surface of the precoated paper is smooth in a hemispherical shape. Since the fine protrusions are formed, the coefficient of friction of the surface is reduced and the amount of wear is also reduced, resulting in extremely excellent scratch resistance.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of the pre-coated paper having scratch resistance of the present invention, and FIG. 2 is a cross-sectional view showing another example of the pre-coated paper having scratch resistance of the present invention. Precoated paper having scratch resistance, 2 is a base paper for decorative paper, 3 is a solid printing layer, 4 is a pattern printing layer, 5 is a first topcoat layer, and 6 is a second topcoat layer.

Precoated paper 1 having scratch resistance according to the present invention
As shown in FIG. 1, the constitution is that a base printing paper 2 is provided with a solid printing layer 3 as a printing ink layer, and the solid printing layer 3 has a first top coat layer containing a silica-based matting agent by gravure printing. 5 and a second top coat layer 6 containing elastic spherical resin beads as a matting agent are laminated in this order.

Precoated paper 1 having scratch resistance according to the present invention
As the base paper 2 for decorative paper used in the above, base paper used for ordinary decorative paper, for example, thin paper, fine paper, Japanese paper, non-woven fabric, kraft paper having a weight of about ²⁰ to 100 g / m ² is used.

The printing layer applied to the base paper for decorative paper 2 may be only the printing layer for solid printing on the whole surface, or the solid printing layer 3 may be provided with a pattern printing layer 4 such as a wood grain pattern or an abstract pattern. It may be one that can be used properly depending on the target product. For forming these print layers, for example, a normal printing method such as a gravure printing method, an offset printing method, a screen printing method is used.

The printing layer on the surface of the base paper for decorative paper 2 is formed by a printing ink containing a polyol compound and an isocyanate compound as a vehicle. The printability, the oil resistance of the obtained decorative paper and the adhesion suitability to the top coat layer are obtained. From the above points, a printing layer using a two-component curable urethane resin as a vehicle, which is a combination of acrylic polyol and hexamethylene diisocyanate, is most suitable.

The first topcoat layer 4 formed on the printed layer surface is formed by a coating agent containing a polyol compound and an isocyanate compound as a vehicle and a silica pigment as a matting agent. From the viewpoint of oil resistance, adhesiveness to the print layer, surface uniformity of the second top coat layer, etc., as in the case of the print layer described above, a two-component curable urethane type combination of acrylic polyol and hexamethylene diisocyanate is used. A topcoat layer containing a resin as a film-forming component is most suitable.

Silica-based pigments are useful components for lowering the glossiness, but if the blending amount is less than 1 part by weight, the glossiness-lowering effect is poor, and if it exceeds 10 parts by weight, the adhesion of the coating film is low. Since it deteriorates the workability and processability, it is preferable to add and blend in the range of 1 to 10 parts by weight, and particularly 1 to 5 parts by weight is suitable.

Pre-coated paper 1 having scratch resistance according to the present invention
The second top coat layer 5 formed on the outermost surface of the is composed of a resin made of a blend of a resin composed of a polyol compound and an isocyanate compound and a melamine-based resin as a vehicle, and is composed of elastic spherical resin beads as a matting agent. The resin composed of the isocyanate compound is the same as that of the first top coat layer, and the melamine-based resin is a methylated melamine resin obtained by further etherifying the condensation product with methanol. The blend ratio of the resin composed of the polyol compound and the isocyanate compound and the melamine resin is 5 to 1 with respect to 100 parts by weight of the resin composed of the polyol compound and the isocyanate compound.
It is preferable to blend in the range of 0 parts by weight, and if it is less than 5 parts by weight, the surface hardness is low, and if it exceeds 10 parts by weight, uneven gloss is caused when hot-pressed in the post-processing step, which is unsuitable.

The elastic spherical resin beads include resin particles composed of polyurethane, polyester, polyethylene, polyamide, acrylic resin and modified products of these resins. Among these resins, acrylic resin has good dispersibility. It is a preferable resin in the present invention in that it has solvent resistance and can give scratch resistance.

The elastic spherical resin beads described above are suitable to have an average particle size of 2 to 20 μm. If the average particle size is less than 2 μm, the scratch resistance of the surface of the top coat layer is insufficient.
If it exceeds 20 μm, a uniform top coat layer cannot be obtained, which is not suitable. The addition amount of the elastic spherical resin beads is 10 to 70% by weight based on the resin component, and particularly 50 to 60% by weight.
It is desirable to add weight percent. If the amount added is too small, a sufficient matting effect cannot be obtained, and if it exceeds 70% by weight, poor dispersion results and ink formation becomes impossible.

Precoated paper 1 of the present invention having scratch resistance
As described above, the first topcoat layer has a constitution in which a silica-based pigment as a matting agent is blended with a two-component curable urethane resin of a polyol compound and an isocyanate compound, so that the decorative paper of the second topcoat layer is formed. Prevents the occurrence of uneven surface gloss due to uneven penetration into the base paper, and the second top coat layer is a resin made of a blend of a resin composed of a polyol compound and an isocyanate compound and a melamine resin, and an elastic spherical resin as a matting agent. By blending the beads, the heat press time when pasting the pre-coated paper on the wood substrate is shortened to improve productivity, and the surface hardness is hard and the gloss of the first top coat layer is matte. The surface of the second top coat layer can be made to have a low gloss and excellent scratch resistance.

Example 1 A colored solid printing layer was formed by a gravure printing method on a surface of a thin paper for building materials having a basis weight of 30 g / m ^{2 using} a printing ink composed of a two-component curing type urethane resin. Then, a top coat ink (1) having the following composition was applied on the colored solid printing layer so as to have a coating amount of 3 to 5 g / m ² (dry), and then dried with hot air at 90 ° C. One topcoat layer is formed, and then the topcoat ink (2) having the following composition is applied and dried under the same conditions as the formation of the first topcoat layer to form the second topcoat layer. ) 7.3
A precoated paper having scratch resistance was obtained.

[0022]   Top coat ink (1)     Acrylic polyol 42 parts by weight     Hexamethylene diisocyanate 11 parts by weight     Silica based matting pigment 8 parts by weight     Defoamer 0.7 parts by weight     Solvent 89 parts by weight

[0023]   Top coat ink (2)     Acrylic polyol 42 parts by weight     Hexamethylene diisocyanate 20 parts by weight     Methylated melamine 3.5 parts by weight     Acrylic resin beads 18 parts by weight     Defoamer 0.7 parts by weight     67 parts by weight of solvent

Example 2 A colored solid printing layer was formed by a gravure printing method on a surface of a thin paper for building materials having a basis weight of 30 g / m ^{2 using} a printing ink composed of a two-component curing type urethane resin. Then, a top coat ink (1) having the following composition was applied on the colored solid printing layer so as to have a coating amount of 3 to 5 g / m ² (dry), and then dried with hot air at 90 ° C. One topcoat layer is formed, and then the topcoat ink (2) having the following composition is applied and dried under the same conditions as the formation of the first topcoat layer to form the second topcoat layer. ) 10.
A precoated paper having a scratch resistance of 5 was obtained.

[0025]   Top coat ink (1)     Acrylic polyol 44 parts by weight     Hexamethylene diisocyanate 11 parts by weight     Silica based matting pigment 6 parts by weight     Defoamer 0.7 parts by weight     Solvent 88 parts by weight

[0026]   Top coat ink (2)     Acrylic polyol 44 parts by weight     Hexamethylene diisocyanate 20 parts by weight     Methylated melamine 3.5 parts by weight     Acrylic resin beads 13 parts by weight     Defoamer 0.7 parts by weight     70 parts by weight of solvent

Example 3 A colored solid printing layer was formed by a gravure printing method on the surface of a thin paper for building materials having a basis weight of 30 g / m ^{2 using} a printing ink composed of a two-component curing type urethane resin. Then, a top coat ink (1) having the following composition was applied on the colored solid printing layer so as to have a coating amount of 3 to 5 g / m ² (dry), and then dried with hot air at 90 ° C. One topcoat layer is formed, and then the topcoat ink (2) having the following composition is applied and dried under the same conditions as the formation of the first topcoat layer to form the second topcoat layer. ) 19.
A precoated paper having a scratch resistance of 5 was obtained.

[0028]   Top coat ink (1)     Acrylic polyol 47 parts by weight     Hexamethylene diisocyanate 11 parts by weight     Silica based matting pigment 4 parts by weight     Defoamer 0.7 parts by weight     Solvent 88 parts by weight

[0029]   Top coat ink (2)     Acrylic polyol 46 parts by weight     Hexamethylene diisocyanate 20 parts by weight     Methylated melamine 3.5 parts by weight     Acrylic resin beads 8 parts by weight     Defoamer 0.7 parts by weight     73 parts by weight of solvent

[0030]

As described above, in the precoated paper having scratch resistance of the present invention, the base paper for decorative paper is provided with the print layer by the gravure printing method, and the top coat layer is divided into two layers. With this structure, the second top coat layer containing the elastic spherical resin beads can be evenly sucked, and a precoated paper having low gloss and excellent scratch resistance can be obtained.

Further, when the pre-coated paper having scratch resistance of the present invention is adhered to a wood base material such as particle board by an adhesive, the hot press time can be greatly shortened and a low-cost decorative board can be obtained. I was able to get it.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a precoated paper having scratch resistance according to the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the precoated paper having scratch resistance of the present invention.

[Explanation of symbols]

1 Scratch-resistant precoated paper 2 Base paper for decorative paper 3 solid printing layer 4 Design print layer 5 First top coat layer 6 Second top coat layer

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-116252 (JP, A) JP-A-5-148466 (JP, A) JP-A-4-140197 (JP, A) JP-A-4- 227776 (JP, A) JP-A-4-316846 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 D21H 27/00-27/42

Claims (2)

(57) [Claims] 1. A two-component curable ureta on the surface of a base paper for decorative paper.
In a pre-coated paper in which a solid printing layer using a resin as a vehicle and a top coat layer are sequentially laminated, a two-component curable urethane in which the top coat layer contains a silica pigment
A first topcoat layer formed of a transparent ink layer of a resin based on the solid printing layer, a two-component curable urethane resin containing elastic spherical resin beads as a matting agent, and a melamine.
A pre-coated paper having scratch resistance, which comprises two layers of a second top coat layer formed on the first top coat layer, which comprises a transparent ink layer of a min-based resin . 2. The precoated paper having scratch resistance according to claim 1, wherein the elastic spherical resin beads are made of acrylic resin and have an average particle diameter of 2 to 20 μm.