JPS6175900A - Production of reinforced 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] (Industrial Field of Application) The present invention relates to a method for producing reinforced paper that is used for furniture, interior decoration materials, etc. by being bonded to plywood, particle board substrates, etc.

(Prior art) Synthetic resin decorative boards using plywood, particle board, etc. as substrates are made of decorative paper impregnated with melamine resin, urea resin, phenol resin, etc. on the surface of the substrate, or similarly impregnated with unsaturated polyester resin. Alternatively, it has been conventionally used to apply coated decorative paper and heat and pressurize it to form a decorative board.

In recent years, in addition to these, a type of decorative paper called fininosudfoil has been manufactured, in which decorative paper is impregnated with resin in advance to strengthen the paper spacing, and if necessary, a top coat is applied.
This becomes a decorative board simply by laminating the substrate, which greatly simplifies the lamination process.

In general, these methods include printing on paper with good permeability, impregnating it with a mixed solution of acrylic resin and melamine resin, and drying it. In other words, by mixing a relatively flexible acrylic resin and a hard and permeable melamine resin in a certain ratio, we can create reinforced paper with a certain flexibility and interpaper strength. It is what it is. (Problems to be solved by the invention) The method of applying decorative paper impregnated with melamine resin or urea resin to the surface of the substrate and applying heat and pressure requires many steps, costs, and special equipment when producing the decorative board. It has its drawbacks.

In addition, since the mixed resin of acrylic resin and melamine resin is exposed on the surface of the paper, crosslinking of the melamine progresses over time, and if a certain period of time passes, the lamination to the substrate will fail. This has the fatal drawback of not being possible with ordinary vinyl acetate adhesives. Further, as the melamine hardens, the paper becomes brittle, resulting in problems such as paper breakage during lamination or post-processing. Also, in order to solve these problems,
It is also possible to lower the crosslinking property by lowering the mixing ratio of melamine resin to 1-ru resin, but in that case, the permeability of the resin into the paper and the strength of the resin itself will decrease, so it will not be possible to strengthen the resin. It becomes impossible to obtain sufficient interpaper strength as paper.

Furthermore, when the amount of acrylic resin is increased, the paper becomes too flexible, and when it is attached to a base material, unevenness on the surface of the base material is likely to occur on the surface of the decorative board, which is a so-called "fading".

The present invention solves the above-mentioned drawbacks of the prior art and provides a method for producing reinforced paper that improves the deterioration of adhesion suitability over time.

(Means for Solving the Problems) The structure of the present invention is a method for manufacturing reinforced paper by impregnating decorative base paper or decorative paper with good permeability with an acrylic resin emulsion and a melamine resin mixture. A composition in which 1a to 50 parts by weight of a polyvinyl acetate resin emulsion having an average particle size of 20 μm or more is added to a liquid based on the solid content of 100 parts by weight of the mixed liquid. This is a method for producing reinforced paper characterized by coating and impregnating from the back side of decorative base paper or decorative paper.

The present invention will be explained in more detail below.

As decorative paper or decorative base paper with good permeability, titanium paper with a size degree of 5 seconds or less, decorative paper with a printed pattern on non-sized paper, or decorative base paper before printing is used. Generally, the basis weight of paper is 3, which is used as base paper for building materials.
0 to 80 g/-rn may be used, but since the aqueous resin is applied and impregnated, it is desirable that the wet strength is 20 Qg/15 mm or more. The impregnating resin used in the present invention is a highly impregnating emulsion that has conventionally been used for Fininosudo foil, but specifically has a particle size of 1 μm.
The following acrylic emulsion has an acrylic resin solid content of 10
For a mixed solution in which 20 to 100 parts by weight of a water-soluble melamine resin as a crosslinking agent was added as a solid content per 0 parts by weight,
Average particle size 20 per 100 parts by weight of resin solid content of the mixed liquid
Polyvinyl acetate emulsion resin with a μ or more of 10 to 5
Add 0 parts by weight to 10 cm to 50 cm with water etc.
It is diluted to an arbitrary viscosity of about 0 centivoise.

The present invention comprises applying and impregnating the above-described impregnating resin from the back side of the decorative paper or decorative base paper with good permeability in an amount of 50 to 200 parts by weight of solid resin per 100 parts by weight of the paper. . As the coating method, known methods such as gravure coating, roll coating, and air knife coating can be selected.

Note that the reinforced paper obtained by the method of the present invention may optionally be subjected to post-processing such as printing and top coating by a known method in a post-process, if necessary.

(Function) By impregnating decorative paper or decorative base paper with resin from the back side as described above, the acrylic emulsion resin and melamine resin with small particle sizes penetrate into the inside of the paper, and the outer layer of the back side is coated with the paper. A resin layer mainly made of vinyl acetate resin having a large particle size is formed.

(Effects) Since the present invention has the above configuration and operation, it has the following effects.

- Since a layer mainly made of vinyl acetate resin is formed on the back side, it is possible to adhere to the base material with vinyl acetate resin even after a long period of time has passed after coating and impregnating the resin.

■As the back side has a layer mainly made of vinyl acetate resin, even if the melamine inside the paper layer crosslinks over time and the paper becomes hard, it will still break easily compared to paper impregnated with only melamine and acrylic emulsion. The paper quality is less likely to become brittle, making it very convenient to handle.

■Melamine resin and acrylic resin are used inside the paper space.
Because it is impregnated with Foil, it has sufficient interpaper strength and surface performance equivalent to that of regular Finiso Sudfoil.

(Example) A surface was printed on titanium paper (size: 2 seconds) of tsubo JgBOi/m''.
Using an air knife coater, the composition shown in 1 was applied and impregnated from the back side of the paper so that the resin solid content was 80 g/m°.

For comparison, the composition shown in Table 2 was coated on the same paper using an air knife coater, and the resin solid content was BO from the back side.
ji/m, coated and impregnated like Tonaro.

24 hours after coating and impregnation, 1 sg/mf (solid content) of urethane resin was applied to the surface of each of the two types of reinforced paper obtained as described above, and the results were as shown in Table 5. Various tests were conducted.

Qin 1. Adhesion: 100. li!
/m゛Apply vinyl acetate adhesive and press 100° with flat pressure press
After laminating under the conditions of C5K9 / CRT710 sec, mark the surface with an X mark with a knife and check the adhesion with Sellotape *2. Folding durability: Measured with a MiT bending tester at a load of 500g

Claims (1)

[Claims] In a method for manufacturing reinforced paper by impregnating decorative base paper or decorative paper with good permeability with an acrylic resin emulsion and melamine resin mixture, a polyvinyl acetate resin emulsion with an average particle size of 20 μ or more is added to the resin mixture. The solid content is 10 to 50 per 100 parts by weight of the solid content of the mixed liquid.
A method for producing reinforced paper, which comprises applying and impregnating a composition added in parts by weight from the back side of decorative base paper or decorative paper.