JPH04202898A - Chromic patterned paper and its production - Google Patents

Abstract

PURPOSE:To obtain the subject product exhibiting a pattern reversibly changing its color with temperature variation or light and having excellent decorative performance by sealing a chromic material in microcapsules and fixing the microcapsules on a paper surface in the form of a prescribed pattern using a specific method. CONSTITUTION:A mold frame is placed on a stock paper produced by wet-paper process while the paper is still in wet state. A mixture of a water-soluble binder and micro-encapsulated chromic material is poured into the mold frame and excess water and water-soluble binder are drained to the back surface of the stock paper to fix the micro-encapsulated chromic material on the paper surface in the form of a prescribed pattern in a uniformly dispersed state. The pattern of the chromic material on the obtained product reversibly changes its color by the change of ambient temperature or irradiation with light of a specific wavelength range.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to chromic patterned paper with a pattern that changes color in response to heat, light, etc., and a method for producing the same, and particularly relates to fusuma paper, shoji paper, etc. , can be used for art booth paper, etc.

[Prior art and technical issues to be solved] In recent years, the demand for Japanese paper has been sluggish, and the paper-making industry has been looking for the development of new products.

However, in woven fabrics, patterns have been created using photochromic and thermochromic materials that change color when exposed to light or heat, and we have tried to apply this to paper, but several techniques have been developed. I found the above problem.

For example, if you try to attach a microcapsulated chromic material to paper after papermaking by screen printing, the pressure applied during printing may crush the capsules, or the paper may have an uneven surface (Japanese paper, wallpaper, etc.). Another problem is that even when screen printing is performed, it becomes uneven.

The present invention was made in view of the fact that it has not been possible to form a chromic pattern on paper, and it is an object of the present invention to provide paper on which a chromic pattern has been formed and a method of forming a chromic pattern suitable for paper, which is an alternative to the screen printing method. is a technical issue.

[Means adopted to solve the problem]

The means adopted by the present inventor to solve the above problem are as follows.

In other words, chromic patterned paper in which microencapsulated chromic material is uniformly dispersed and fixed in a predetermined pattern on the paper surface, and the pattern reversibly changes color when the ambient temperature changes or when exposed to light. In addition, the raw paper was wet-formed, a mold was placed on the paper while the raw paper was in a wet state, and a microencapsulated chromic material mixed with a water-soluble binder was poured into the mold. After that, a method for producing chromic patterned paper was provided by draining excess water and water-soluble binder to the back side of the raw paper.

〔Example〕

The present invention will be explained in detail below.

Beat the wood valve to a fineness of 400cc, mix it with a neutral sizing agent to prevent bleeding, and use a sheet machine to produce a basis weight of 70g.
/m, and this is used as raw material paper. Next, a mold (in the shape of a daffodil flower) is placed on top of this raw material paper, and a solvent is poured into the mold. This solvent is made of a slurry-like thermochromic material in which liquid crystal is microencapsulated using a phase separation method.The weight ratio of the solvent is 4% (trade name: Kinermatic Liquid Crystal, manufactured by Threechick-Davis), and the weight ratio of polyvinyl alcohol as a binder is 2%. After producing the patterned paper, it is poured into a mold so that the weight density of the chromic material per LCD is approximately 0.01 g/al on average. With this level of planar density of chromic material, the patterned paper loses little flexibility after manufacture.

After that, the water and binder inside the mold are forcibly sucked out from the back side of the raw paper. Then, since the particle size of the chromic material is large, it remains on or in the raw material paper, but most of the water is dehydrated, and furthermore, of the polyvinyl alcohol,
The rest that binds to the chromic material and paper fibers washes away with the water.

If this paper is dried, a chromic patterned paper is obtained.

Although the present embodiment is configured as described above, the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the claims. The binder may be discharged by natural flow, or a photochromic material may be used instead of a thermochromic material.

Further, the above method for producing chromic patterned paper can also be applied to forming a chromic pattern on a wet-laid nonwoven fabric.

[Effects of the present invention]

As described above, the color of the chromic patterned paper of the present invention changes depending on light and temperature. You can draw patterns beautifully,
Can be used for purposes such as decorative paper.

Furthermore, the method for producing chromic patterned paper of the present invention does not apply excessive force to the microcapsulated chromic material, and the chromic material can be attached to the paper without deteriorating its quality. Furthermore, unlike screen printing, the state of adhesion of the chromic material is not affected by the unevenness of the paper surface, so it can be easily applied to papers that are especially excellent as decorative papers such as Japanese paper and wallpaper, without requiring much skill. .

As described above, the chromic patterned paper of the present invention and the method for producing the same have high industrial utility value.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a chromic patterned paper according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a step of fixing a chromic material onto the paper in a method for manufacturing a chromic patterned paper according to an embodiment of the present invention.

Claims (2)

[Claims] (1) Microencapsulated chromic material is uniformly dispersed and fixed on the paper surface in a predetermined pattern, and by changing the environmental temperature or receiving light in a predetermined wavelength range, the chromic material becomes patterned. Chromic patterned paper is characterized by its reversible color change. (2) Raw paper is wet-formed, a mold is placed on the paper while the raw paper is still wet, and after pouring the water-soluble binder and microencapsulated chromic material into the mold, excess water is removed. A method for producing chromic washi paper, which comprises discharging and a water-soluble binder to the back side of raw paper.