JPS61289197A - Reinforced paper for cosmetic paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a resin-reinforced paper with a relatively low basis weight, particularly for use as decorative base paper for building materials. The present invention provides a reinforced paper that is suitable for lamination.

(Prior art) Conventionally, methods of reinforcing resin as a method to improve the weakness of paper spacing, which is a drawback of paper, can be roughly divided into two methods: internal addition of resin during paper making, and resin impregnation after paper making. This is done in two ways.

(The method of internally adding resin to the paper that the invention seeks to solve has the advantage that it can be strengthened almost uniformly regardless of the basis weight of the paper, and does not require a separate process for strengthening. Due to the poor yield of resin, it has been difficult to fully achieve the purpose of reinforcing the paper gap.On the other hand, the method of resin impregnation after papermaking generally involves dipping it in an impregnating solution, and it is difficult to fully achieve the purpose of reinforcing the paper spacing. Two types of base paper are used: a base paper that does not contain pigments or a base paper that contains pigments such as titanium paper.

In the former case, the purpose of reinforcing the paper can be achieved by sufficiently impregnating it with an appropriate resin, but since the obtained reinforced paper is transparent, the opacity of the obtained reinforced paper is This results in a product with no hiding power at all as a decorative base paper for building materials.

In the latter case, a satisfactory hiding power can be obtained, but the permeability of the resin is greatly reduced, the range of resin selection is very narrow, and although the purpose of reinforcing the paper gap can be achieved, - In particular, there are problems with surface smoothness, ink adhesion, adhesive selectivity, etc. in post-processing the front and back surfaces, such as adhesion to printing plates.

In addition, the productivity of the impregnating and drying process in the Tobu-zuke method was significantly lower than that of general paper making, and in reality, the process was extremely limited in terms of price.

The present invention solves the problems of conventional products as described above, and has a surface that has smoothness and ink adhesion suitable for post-processing such as printing and top coating, and a back surface that is compatible with commonly used adhesives. In contrast, it provides resin-reinforced paper with a wide selection range.

(Means for Solving the Problems) In other words, the gist of the present invention is to apply a thermoplastic resin to a relatively low basis weight, pigment-free base paper with good permeability from the surface of the base paper and penetrate halfway into the paper layer. After that, a 111 finger containing a large amount of titanium oxide pigment is impregnated from the back side to the portions of the paper layer impregnated with the resin to increase the hiding power of the paper.

The contents will be explained in detail below.

The base paper used in the present invention is non-size paper or low-size paper with a basis weight of 501/m1 or less, does not contain pigment, and has a Klemm's water absorbency (JIS, 98141) of 15 IoIZ or more from the viewpoint of permeability. preferable.

The resin to be impregnated from the surface of the base paper is one whose main component is a thermoplastic resin such as acrylic emulsion, vinyl acetate emulsion, or rubber latex, or a thermoplastic resin and water-based thermosetting resin such as melamine, urea, epoxy, or polyamide.
Any material can be used as long as it is a mixture with arsenic resin and can be coated by a commonly used coating method such as roll coating, kiss coating, knife coating, or air knife coating IF. The content of the thermosetting resin must be 50% by weight or less in order to maintain the thermoplasticity of the surface. The resin to be impregnated from the back side of the base paper may be the same or different from the resin impregnated from the front side of the base paper, and must contain a large amount of titanium oxide, and must be coated with a conventional coating such as roll coat, kiss goat, knife coat, air knife coat, etc. Any material can be used as long as it can be coated by the coating method used.

As a result of various experiments, the amount of titanium oxide to be added is 100 to 500 PHR (Pigment per H
If it is less than that, the hiding power will be insufficient, and if it is more than that, the penetration of the resin will be adversely affected. It was concluded that the appropriate coating amount was 7 to 15 t/ridry.

The paper coated with thermoplastic resin is smoothed using a calender to create reinforced paper with good printability.

These two impregnation steps may be performed consecutively with a drying step in between, or may be performed in separate steps.

(Function) Since the present invention has the above-described configuration, the resin can penetrate into the base paper very easily (and paper-to-paper reinforcement can be achieved by a normal coating method).

In addition, the resin impregnated from the surface of the base paper is mainly thermoplastic resin, and the surface smoothness is improved by calender press.
Also, does the resin impregnated from the back side of the base paper contain a large amount of titanium oxide and have the hiding power as reinforced paper? In addition to raising
The surface becomes porous.

It also improves adhesive receptivity and prevents set-off due to printing ink blocking.

(Effects of the invention) ■ The entire paper layer is uniformly impregnated with a large amount of resin, and the sheet-to-paper strength is excellent.

■ A thermoplastic +H resin layer is formed on the surface, providing excellent printability and printing ink receptivity.

■ A resin layer containing a large amount of titanium oxide is formed on the back surface, providing excellent hiding and blocking resistance.

■ Front and back sides are different! Since it is possible to apply one type of resin, the front and back sides are the same (difficult to apply since the two sides are sealed) using the usual impregnation method.It is now possible to apply different post-processing materials, such as printing ink and adhesive.

(Example) Sizeless paper with basis weight 381/- (Klemm water absorbency 2 (lrm
A resin composition containing polyacrylic emulsion, polyvinyl acetate emulsion, and melamine formaldehyde resin in a solid ratio of 50:45:5 was adjusted to a concentration of 30% and solidified using an air knife coater. 157/771' was coated on the mold, and after drying at 150C for 30 seconds, a multilayer composition containing a polyacrylic emulsion, titanium oxide, and extender pigment in a solids ratio of 50:100 near 0 was applied on the back side. Using an air knife coater, apply 1 sy/, j of the solid content, dry for another 20 seconds at 160C, then smooth the surface with a calendar press, then apply a wood grain pattern using a cellulose ink and a gravure printing machine. , and then printed with acrylic urethane top coat m resin using the same gravure printing machine.
A decorative sheet was prepared by drying at C for 60 seconds.

This decorative sheet was press-attached to a particle board using a vinyl acetate-based adhesive to produce a decorative board.

In terms of physical properties, this decorative board had a top coat layer of 5 ink layers and a paper layer in a peeling test with cellophane tape.

No peeling at each of the adhesive layers and their interfaces.

The resulting decorative board has excellent peeling resistance with cellophane tape, and in terms of design, the decorative board has a deep, luxurious feel that cannot be expressed with conventional city fat-impregnated paper. For comparison, Table 1 shows a comparison of the surface smoothness, hiding power, cellophane tape resistance, and adhesive suitability of the bright resin-reinforced paper of each company and the resin-reinforced paper of the present invention.

Claims (1)

[Claims] A base paper that does not contain pigments and has a basis weight of 50 g/m^2 or less and a Clem water absorption of 15 mm/min or more, is impregnated with a resin mainly composed of thermoplastic resin from the surface to the middle of the paper layer, and is made from the back surface of the paper layer. A reinforced paper for decorative paper, which is impregnated with a resin composition containing 100 to 300 parts by weight of titanium oxide based on 100 parts by weight of the resin up to the portion impregnated with the resin at a solid content of 7 g/m^2 or more.