JPH0419938B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a precoated decorative sheet for repainting.

As a painting method for finishing the surface of furniture, etc., there is a method of applying paint directly to the base material of furniture, etc., and a method of laminating the surface of the plywood base material of furniture, etc. with a decorative sheet with a wood grain pattern etc. After that, there is a method of recoating the decorative sheet with resin. This decorative sheet is called a decorative sheet for repainting.

By the way, various types of decorative sheets for repainting have been used in the past.

For example, there is a pre-coated paper type in which the decorative sheet for repainting that is laminated to a base material such as plywood for furniture etc. is coated with urethane or amino alkyd resin (Japanese Patent Publication No. 49-46041, etc.). However, this decorative sheet for repainting has a drawback that when repainted, the repainting resin and the top resin of the precoated paper made of the above-mentioned resin do not adhere well and peel off at the interface.

On the other hand, there is an after-coated paper type of decorative sheet for repainting that is not coated with a top resin and does not have a surface protective layer. However, this decorative sheet for repainting has the disadvantage of high cost due to ink peeling during the lamination process, transportation, and storage, uneven resin impregnation during repainting, and increased amount of resin used. Another method is to laminate this aftercoat paper type decorative sheet for repainting, then roll coat it with aminoalkyd resin from which slip agents such as silicone have been removed, and then repaint it. It is expensive and has the drawbacks of limited recoating resin selection and lack of versatility.

The present invention has been developed in view of the above, and it is possible to prevent penetration of repainting resin when applying it, and to obtain a high-quality paint finish and texture with a small amount of application.
To provide a pre-coated decorative sheet for repainting which is highly selective in the type of resin for repainting.

That is, the present invention is based on a printing base sheet having a cellulosic component as at least one of its constituents, on which a pattern is applied using a printing ink having a cellulose resin as at least one of its vehicle constituents. The gist is a pre-coated decorative sheet for repainting that is coated with a top coat containing a polyol component, an isocyanate component, and a cellulose component.

Embodiments of the present invention will be described below with reference to the drawings.
Precoated decorative sheet for repainting according to the present invention 1
The printing base material sheet 2 constituting the printing base material may be any material as long as it has a cellulose component as part or all of the constituent components and can be used as a printing base material. however,
Preferably, the sheet has a paper layer structure, and more preferably a sheet having a weight of about 23 g/m ² to 120 g/m ² .
If it is ^less than 23g/m2, print ink bleed through and lack of hiding power are likely to occur. If it exceeds 120 g/m ² , the top coat will be sucked in, making it difficult to keep it on the surface layer and increasing costs. In addition to pure cellulose, cellulose-based components include hemicellulose, nitrified cotton that is chemically modified cellulose,
cellulose acetate, hydroxymethyl cellulose,
Carboxymethyl cellulose and the like can be used alone or in combination as a constituent component of the sheet. As components other than cellulose components, for example, titanium dioxide or various pigments, thermoplastic resins, thermosetting resins, latex, starch, or other additives are used. By having the printing base material sheet with the above structure, the printing effect of the printing ink described below is excellent, and the coating effect of the top coating paint described later is good, and the product can effectively prevent the penetration of the repainting resin. Manufacturing becomes possible.

A desired pattern is printed on the printing base sheet 2 as described above to form a printing ink layer for the pattern, but if necessary, a solid printing ink may be added below the printing ink layer 4 for the pattern. By forming the layer 3 in advance, the printing effect of the pattern can be improved. The pattern printing ink constituting the present invention is an ink having a cellulose resin as part or all of the vehicle component.

As the cellulose resin, nitrified cotton alkyd resin, cellulose acetate, hydroxymethyl cellulose, carboxymethyl cellulose, etc. can be used, but there is no particular limitation. By using these cellulosic resins as part or all of the constituent components of the vehicle, the printing effect on the printing base sheet having the above-mentioned cellulose-based components as part or all of the constituent components becomes excellent, and It is sufficiently hidden by painting with the top coat described below, and the top coat will not peel off from the printed area. Examples of resins other than cellulose resins include vinyl chloride resin, acrylic resin, polyester resin, polyvinyl butyral resin, and polyurethane resin.
Alternatively, these copolymers may be used alone or in combination.

A top coat is applied on the printing ink layer for the above-mentioned pattern to form a top coat layer 5. The top coat of the present invention has three components: a polyol component, an isocyanate component, and a cellulose component. It is a transparent resin.

As the polyol, vinyl chloride polyol, acrylic polyol, polyester polyol, polyether polyol, etc. are used.

As the isocyanate, tolylene diisocyanate, methylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, etc. are used.

As the cellulose component, nitrified cotton, cellulose acetate, hydroxymethyl cellulose, carboxymethyl cellulose, etc. are used. As a component of the top coat, the cellulose component provides abundant hydroxyl groups or functional groups, and in addition to increasing its affinity with the recoating resin through chemical bonds, it also has an affinity with the underlying printing base sheet and printing ink, making it strong and strong. Develops interlaminar strength.

As the cellulose component, nitrified cotton is more preferably used. Nitrified cotton provides an excellent effect in terms of interlayer reinforcement through reaction with isocyanate, and is also advantageous in terms of cost. The ratio of the polyol component to the isocyanate component may be the theoretical blending ratio of urethane bonds, but preferably the isocyanate component is used in an amount greater than the theoretical blending amount by 5 to 20% by weight. This is because the isocyanate component causes intermolecular bonding with the cellulose component of the printing base sheet/printing ink or the recoating resin component, causing interlayer bonding between the printing base sheet layer, printing layer, or recoating resin layer and the top coat layer. This is because it is thought to have the effect of strengthening.
Further, the appropriate amount of the cellulose component is 20 to 40% by weight based on 100 parts by weight of the total of the polyol component and the isocyanate component.

If it is less than 20% by weight, the cellulose component also reacts with the isocyanate component in the top coat and is consumed, resulting in poor affinity with the resin component for repainting and making the resin layer for repainting easy to peel off.

On the other hand, if it exceeds 40% by weight, the bond density of the urethane bonds in the top coating layer becomes low, and the interlayer strength as a whole decreases. As the solvent for the top coating, aromatic, ketone, ester, etc. are used alone or as a mixed solvent.

As the aromatic system, for example, toluene, xylene, etc. are used. Examples of ketones used include methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of esters used include methyl acetate, ethyl acetate, butyl acetate, and the like.

As a coating method for the top coat, a gravure coating method, a roll coating method, etc. can be used.

Although the coating amount is not particularly limited, a coating amount of 5 g dry/m ² or less gives preferable results in terms of coating effect during recoating.

The pre-coated decorative sheet for repainting of the present invention having the above-described structure has an adhesive layer 7 on a base material 8 such as furniture.
laminated through.

Then, a repainting resin is applied from above the top coating layer 5 of the laminated precoated decorative sheet for repainting to form a repainting resin layer 6.

Next, specific examples of the present invention will be shown.

Example Using thin paper with a basis weight of 30 g/m ² (pre-coated base paper manufactured by Nagoya Pulp Co., Ltd.) as a printing base sheet, printing ink (MA manufactured by Moroboshi Ink Co., Ltd.) containing nitrocotton alkyd resin as a vehicle was used as a printing base sheet. With a gravure rotary press,
A concealing solid coat and pattern printing were applied.

Next, a top coat containing 15 parts by weight of polyester polyol, 30 parts by weight of xylene diisocyanate, 15 parts of nitrified cotton, 20 parts of methyl ethyl ketone, 10 parts of toluene, and 10 parts of butyl acetate was applied to 2 g dry/m ² using a rotogravure rotary press. When coated, a pre-coated decorative sheet for repainting was obtained that had repainting performance even after two years had passed.

The above pre-coated decorative paper for repainting is attached to a 2.7 mm thick plywood base material (manufactured by Noda Plywood Co., Ltd.) using a vinyl acetate adhesive (AC315, manufactured by Chuo Rika Co., Ltd.), and then When spray painting was performed using an acrylic lacquer spray (Lloyd Chemical Co., Ltd. Touchup Spray) at 10 g dry/m ² , a deep coated plywood was obtained.

As is clear from the above examples, a pattern is printed on a printing base sheet having a paper layer structure using a printing ink containing a nitrified alkyd resin as a vehicle, and then polyester polyol, xylene diisocyanate, and nitrified cotton are added as components. By applying a top coat of paint, a precoated decorative sheet for repainting with high durability over time and excellent repainting effect was obtained.

As explained above, according to the present invention, a pattern is created by using a printing ink having a cellulose resin as at least one of the vehicle components on a printing base sheet having a cellulose component as at least one of the components. By applying a top coat containing a polyol component, an isocyanate component, and a cellulose component as constituent components after printing, it has unprecedented durability over time and excellent ability to prevent the penetration of repainting resin. It has now become possible to provide a precoated decorative sheet for repainting that has a good finish, high adhesion to the repaint resin, and is highly selective for the repaint resin.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a pre-coated decorative sheet for repainting according to the present invention, and FIG. 2 is a schematic cross-sectional view of an example of use of the pre-coated decorative sheet for re-painting according to the present invention. 1... Pre-coated decorative sheet for repainting, 2...
Printing base sheet, 4...Printing ink layer for design, 5
...Top paint layer.

Claims (1)

[Claims] 1 At least one of the constituent components is a cellulose component.
A pattern is applied on a printing base sheet having a seed as a seed using a printing ink having a cellulose resin as at least one of the vehicle components, and then a polyol component, an isocyanate component, and a cellulose component are added as components. A pre-coated decorative sheet for repainting, characterized in that it is coated with a top coat of paint.