JPH051390Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is used as decorative paper for building materials with a relatively low basis weight, and relates to a resin-reinforced paper that is suitable for printing on the front surface and suitable for applying adhesive to the back surface. It is.

(Prior art) Conventionally, reinforced papers for decorative paper that have improved interpaper strength and concealment properties can be roughly divided into base papers containing titanium or colored pigments impregnated with resin, and paper containing titanium or colored pigments. There is one in which a resin is impregnated or internally added to a base paper that does not contain pigment, and then the surface is coated with a resin containing a large amount of pigment.

In addition, many reinforced papers for decorative paper impregnated with different resins from the front and back to change the properties of the front and back have been devised, and the applicant has also disclosed them in Japanese Patent Application Laid-Open No. 119296/1983.

(Problems to be solved by the invention) In the case of the former reinforced paper for decorative paper having concealment properties, there is a manufacturing problem in which the pigment content in the base paper and the impregnating property of the impregnating resin conflict with each other. For this reason, the resulting reinforced paper is unsatisfactory in either its opacity (hiding ability) or interpaper strength, and the surface of the base paper itself is rough, making it extremely unsuitable for printing. It was hot. In addition, although the latter has sufficient paper-to-paper strength, it has problems with the adhesion and heat resistance of the surface resin, and peels easily when exposed to high temperatures, and does not have sufficient physical properties as a final product. The problem is that it cannot be obtained.

In addition, reinforced paper for decorative paper is impregnated with different resins from the front and back sides, and at least one side must be made of a thermally crosslinkable resin in order to have sufficient strength between the sheets, which inevitably limits the adhesives that can be used and reduces the suitability for printing. It's not enough or it's not enough. It is also possible to apply a thermoplastic resin on top of the thermally crosslinkable resin, but this has the problem of poor adhesion and easy peeling.

Therefore, the present invention solves the above problems, and at the same time, the paper-to-paper strength is sufficiently strengthened, and at the same time, the surface has appropriate smoothness and ink adhesion for post-processing such as printing and top coating, and the back surface has The present invention provides a physically superior reinforced paper for decorative paper that has a wide range of options for commonly used adhesives and has sufficient hiding properties.

(Means for solving the problems) The configuration of the present invention will be explained with reference to the drawings. Figure 1 shows a cross-sectional view of the reinforced paper for decorative paper according to the present invention, in which the upper paper layer of base paper 1 is made of polyamide.
It contains a resin composition 2 whose main component is an epichlorohydrin resin, a resin composition 3 whose main component is a thermoplastic resin in the lower part of the paper layer, and 100 parts by weight of a resin on the surface of the base paper 1. Thermoplastic resin composition layer 4 containing 100 to 600 parts by weight of titanium oxide
is provided.

FIGS. 2 and 3 are cross-sectional views of the structure of the reinforced paper for decorative paper according to the present invention in the order of manufacturing steps. A resin composition 3 containing a thermoplastic resin as a main component is coated and impregnated on the back side of the base paper 1, and then a resin composition 2 containing a polyamide/epichlorohydrin resin as a main component is coated and impregnated on the front side of the base paper 1. , 100 to 100 parts by weight of titanium oxide per 100 parts by weight of resin.
By applying the resin composition 4 containing 600 parts by weight, the desired reinforced paper for decorative paper can be obtained.

Next, the configuration of the present invention will be described in detail. Base paper 1
From the viewpoint of permeability, sizeless paper with a basis weight of 60 g/m ² or less is desirable. The resin composition 2 containing a polyamide/epichlorohydrin resin as a main component may be a polyamide/epichlorohydrin resin alone or an aqueous resin such as melamine, acrylic, or epoxy, which is generally mixed into pulp during paper manufacturing and frequently used as a wet paper strength enhancer. using a mixture with resin,
As the resin composition 3 containing a thermoplastic resin as a main component, an aqueous thermoplastic resin such as acrylic, vinyl acetate, latex, etc. alone or a mixture with an aqueous thermosetting resin such as melamine, urea, epoxy, polyamide, etc. can be used. The content of thermosetting resin must be 50% by weight or less in order to maintain flexibility.

Resin composition 4 containing 100 to 600 parts by weight of titanium oxide based on 100 parts by weight of resin is applied to the surface by adding 100 parts by weight of resin to the same resin as resin composition 3 whose main component is a thermoplastic resin. Titanium oxide or a mixture of titanium oxide and colored pigment
It is appropriate to add 100 to 600 parts by weight. If titanium oxide is less than 100 parts by weight, the opacity will be insufficient, and if it is more than 600 parts by weight, the interpaper strength will be weak. Further, if necessary, the surface may be smoothed by calender press.

In order to produce the reinforced paper for decorative paper of the present invention, coating and impregnation may be carried out by a commonly used coating method such as roll coating, kiss coating, knife coating, air knife coating, etc. based on the above-mentioned formulation.

Here, the polyamide/epichlorohydrin resin referred to in the present invention refers to an epoxidized polyamide resin typified by polyamide amine/epichlorohydrin resin, which has the following characteristics. In other words, because it is cationic, it has excellent adhesion to paper, does not require a fixing agent, can be used in a wide range of environments from weakly acidic to alkaline, does not contain formalin, and has thermal crosslinking properties because it has an epoxy ring in its side chain. Things, etc. can be mentioned.

(Function) Resin composition 4 containing 100 to 600 parts by weight of titanium oxide based on 100 parts by weight of resin has excellent opacity due to the titanium oxide, and since it is thermoplastic, the surface can be smoothed by calendar pressing. It is easy to print and has excellent printability.

Furthermore, the resin composition 2, which has polyamide/epichlorohydrin resin as its main component, does not have film-forming properties, and the surface obtained after permeating into paper is porous. Therefore, when applying resin thereon, the resin easily enters the inside, and phenomena such as repelling are not observed. It can also be expected to have an anchoring effect and exhibits excellent adhesion. In the case of general thermosetting resins such as melamine resins, a film is formed on the surface, so if it is applied over it, it is relatively easy to repel, and impregnation with the resin cannot be expected. Therefore, it is difficult to achieve sufficient adhesion.

Furthermore, the polyamide/epichlorohydrin resin has excellent permeability into paper and is thermosetting, so it can sufficiently strengthen the paper-to-paper strength.

Resin composition 3, which has thermoplastic resin as its main component, has not only interpaper strength but also the biggest drawback of polyamide/epichlorohydrin-based resins, and therefore cannot be used as an impregnated resin for reinforced paper for decorative paper.
When the printing ink dries, it loses moisture and becomes extremely brittle, making it difficult to pass through the printing machine.In addition, it absorbs moisture at high humidity and becomes soft, resulting in severe thinning when bonded to plywood or particle board with a water-based adhesive. It plays a role in supplementing this point. In other words, since it is thermoplastic, it becomes plastic when the printing ink dries, compensating for the brittleness of polyamide/epichlorohydrin resin, and also prevents polyamide/epichlorohydrin resin from coming into direct contact with moisture when laminating with a water-based adhesive, making it usable. There is a wide range of adhesives to choose from, including water-based, oil-based, and hot melt adhesives.

( ^Example ) Polyacrylic emulsion, polyvinyl acetate emulsion,
Melamine formaldehyde resin solid ratio 50:45:
A resin composition containing a proportion of 5% was adjusted to a concentration of 30%,
Apply 10g/ ^m2 solids using an air knife coater, dry at 150℃ for 30 seconds, and then coat the surface with polyamide.
Solid ratio of epichlorohydrin resin and epoxy resin
A resin composition containing a ratio of 70:30 was adjusted to a concentration of 40%, and the solid content was 7g/m ² using an air knife coater.
After coating and drying for an additional 30 seconds at 150°C, a resin composition containing polyacrylic emulsion, titanium oxide, and extender pigment in a solid ratio of 50:120:40 was hardened using the same air knife coater. By type
After applying 15 g/m ² and drying at 150℃ for 20 seconds, the surface was smoothed with a calendar press, a wood grain pattern was printed using a gravure printer using cellulose ink, and acrylic urethane top coat resin was applied in the same manner. Coated with a gravure printing machine and heated at 170℃
A decorative sheet was prepared by drying for 30 seconds.

Furthermore, this decorative sheet was press-affixed to a particle board using a vinyl acetate adhesive to produce a decorative board.

In terms of physical properties, this decorative board did not peel off at each of the top coat layer, ink layer, paper layer, adhesive layer, or at their interfaces in a peel test with adhesive tape, making it a decorative board with extremely good adhesive tape peelability. ,
The design also has a depth that cannot be achieved with conventional resin-impregnated paper.

For comparison, one was coated and impregnated with a polyamide/epichlorohydrin resin/epoxy resin composition (same formulation as in the example) alone, and the other was coated and impregnated with a polyacrylic/polyvinyl acetate/melamine formaldehyde resin composition (same formulation as in the example) alone. When products were manufactured using the same method as in the example, the former was difficult to print due to severe paper breakage during printing, and the latter was unable to be applied uniformly due to cracking occurring on the coated surface when applying the resin containing titanium oxide. Furthermore, the resin layer containing titanium oxide blistered due to the high temperature.

(Effects of the invention) Polyamide/epichlorohydrin resin is a thermosetting resin with excellent permeability, and also has good adhesion to thermoplastic resins, and different thermoplastic resin layers can be provided on both the front and back sides, making it possible to Not only does it have sufficient strength, but it also has excellent printing ink receptivity on the front surface and adhesive receptivity on the back surface.

Since the thermoplastic resin composition on the surface contains a large amount of titanium oxide, it has sufficient interpaper strength and at the same time has excellent hiding properties.

Polyamide/epichlorohydrin resin has good adhesion, so there is no need to peel between layers, and it has excellent heat resistance.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of the reinforced paper for decorative paper of the present invention, and FIGS. 2 and 3 show cross-sectional views of the reinforced paper for decorative paper of the present invention in the order of manufacturing steps. 1...Base paper, 2...Resin composition containing polyamide and epichlorohydrin resin as main components, 3...
Resin composition containing thermoplastic resin as main component, 4...
A thermoplastic resin composition layer containing 100 to 600 parts by weight of titanium oxide based on 100 parts by weight of resin.

Claims (1)

[Scope of utility model registration request] The upper paper layer of the base paper contains a resin composition containing a polyamide/epichlorohydrin resin as a component,
The lower part of the paper layer contains a resin composition mainly composed of a thermoplastic resin, and a thermoplastic resin composition layer containing 100 to 600 parts by weight of titanium oxide per 100 parts by weight of the resin is further provided on the surface. Reinforced paper for decorative paper.