JP2665566B2 - Design paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a design paper used for a book cover, a cover, an envelope, a handbag, a notepaper, and the like. The present invention relates to a design paper which has a transparency lower than that of a non-patterned portion and has an excellent contrast between a patterned portion and a non-patterned portion and which has a transparent feeling.

[Prior Art] Conventionally, various methods for producing transparent paper have been known. Typical methods are a method of treating paper with concentrated sulfuric acid, a method of highly beating chemical pulp to make paper, a wax and a synthetic base paper. There are a method of treating a transparentizing agent such as a resin, a method of heating and pressing synthetic fiber or synthetic pulp mixed paper to make it transparent.

On the other hand, various methods for producing a design paper in which the pattern portion is opaque and the non-pattern portion is transparent have been proposed.

For example, Japanese Patent Publication No. 50-25048 discloses a method of heat-pressing a polyolefin fiber-blended paper with an embossing roll having a smooth convex portion, which is disclosed in Japanese Patent Publication Nos. 50-3802 and 61-70092. Japanese Patent Laid-Open No. 63-256798 proposes a method of partially treating a base paper with a specific resin and a solvent.

[Problems to be Solved by the Invention] However, these conventional methods are not elegant because there is no difference between the unevenness of the pattern portion and the non-pattern portion, or the difference is small, and the method of Japanese Examined Patent Publication No. 250-25048. Has a problem in that a uniform transparency cannot be obtained in the non-patterned portion, and the resin adheres to and accumulates on the hot roll during manufacturing, which makes continuous operation difficult. Further, the method of Japanese Examined Patent Publication No. 50-3802 has a big problem that it becomes difficult to make transparent when the base paper becomes thick.

The present invention solves the problems of these conventional methods.

Composition of the Invention Designed papers in which the amount of fibers in the thickness direction of the paper is almost uniform and the pattern portion is a convex portion are known, and generally, the embossing treatment is performed on the paper, or the wet paper on the paper machine is embossed. It is processed by a felt press and manufactured.

It is easily predictable that a transparent convex design paper can be obtained by using this design paper as a base paper and impregnating it with a clarifying agent. In addition, since the non-patterned portion of this base paper has a higher density than the convex portion, the transparentizing agent is more impregnated in the low-density convex portion. However, even when actually manufactured by such a method, as will be described later, there is no large difference in transparency between the convex pattern portion and the non-pattern portion, and an excessive amount of the clarifying agent stays on the surface of the non-pattern portion. As it is dried, it causes a defect called "shining", in which the glossiness of that part is large,
It turns out that only design paper with low commercial value and poor taste can be obtained.

As a result of diligent studies, the inventors of the present invention have processed the pattern under a certain specific condition so that the convex pattern portion is much more opaque than the non-pattern portion, and the contrast between the convex pattern portion and the non-pattern portion is large. For the first time, we found that there is no "shining", and therefore a design paper with great practical value can be manufactured.
The present invention has been completed.

That is, the present invention imparts a convex pattern and a non-patterned portion to a base paper having a substantially uniform fiber amount in the thickness direction, and makes the clarifying agent dissolved in the container solvent to be less than or equal to the void volume occupied by the non-patterned portion. After the coating, it is dried to obtain a design paper in which the transparency of the difference between the convex pattern and the non-patterned part is increased, and further, the convex pattern is provided only on one side of the base paper, and the opposite side of the convex surface ( It relates to obtaining a design paper coated with a clarifying agent from a smooth surface).

[Means for Solving the Problem] The base paper used in the present invention needs to have a substantially uniform fiber amount in the thickness direction, and to have convex and non-patterned portions on its surface. . Therefore, a base paper having a non-uniform fiber amount in the thickness direction, for example, Japanese Patent Publication No.
50-32564, Japanese Patent Publication No. 51-44206, and other stencil papers that intentionally break the texture or stencil papers are not suitable for the present invention.

The base paper used in the present invention is a paper machine, or a method of pressing a wet paper having a water content of about 15% hydrated into a papermaking paper with an embossing roll such as rubber, metal, or synthetic resin, and water on the paper machine. A wet paper with a rate of about 50% is manufactured by a method such as press-molding with felt having a knitting pattern.

The material used for the base paper may be wood pulp, non-wood plant pulp, synthetic pulp such as polyolefin, or synthetic fiber such as rayon, vinylon, nylon, polyester, or a mixture thereof. Further, if necessary, various fillers, colorants, sizing agents, paper-strengthening agents and the like can be appropriately used in combination.

The area of the convex pattern is generally 70% of the total area of the base paper.
% Or less is preferable. When the area of the convex pattern part exceeds 70% when the base paper is made transparent, the area of the non-pattern part, that is, the part with large transparency decreases, and the contrast with the convex pattern part with small transparency (large opacity) This is because it is often difficult to recognize and the design effect is reduced.
However, it is not limited to this depending on the design.

In the present invention, the base paper produced in this manner is coated with a clarifying agent dissolved in an organic solvent to make the non-patterned portion transparent.
A water-based clearing agent, that is, a liquid in which a water-soluble resin is dissolved in water,
Alternatively, if an aqueous synthetic rubber latex or a synthetic resin emulsion is used, the intended effect cannot be obtained. Water-soluble polymers such as polyvinyl alcohol, starch, casein, carboxymethylcellulose, polyvinylpyrrolidone, polyacrylamide, polyethylene oxide are 10
It has a high viscosity even at about 10% concentration, so even if it is coated, it does not easily penetrate into the base paper, tends to stay on the surface, causing "shining", and the resin adhesion amount is small, so the transparency effect is also low. is there.

In addition, when coating synthetic rubber latex or synthetic resin emulsion, the rubber or resin forms fine particles, so the filter action works on the base paper, especially in the non-patterned areas where the density is high, and it penetrates into the base paper. Can not achieve the purpose.

On the other hand, a clarifying agent obtained by dissolving a synthetic resin or the like in an organic solvent can easily obtain a high-concentration, low-viscosity solution,
It can be suitably used in the present invention because it has a high permeability to the base paper and a large resin adhesion amount.

As the clarifying agent that can be used in the present invention, any known clarifying agent can be used as long as the above-mentioned conditions are satisfied. Examples thereof include waxes such as paraffin, higher fatty acid, fatty acid amide, and fatty acid alcohol ester, and phenol. fat,
Urea fat, epoxy resin, melamine resin, alkyd resin, etc., or thermosetting resins modified with these, polyacrylic acid ester, polymethacrylic acid ester, polyvinyl chloride, polyvinyl acetate, polystyrene, polybutene, polyester, polyurethane, polyamide And derivatives of cellulose or polysaccharides such as nitrocellulose, cellulose acetate, cellulose acetate butyrate, hydroxyethyl cellulose, sucrose acetate isobutyrate, rosin, rosin ester, dammar resin, shellac, etc., or modified resins or molecules thereof. UV curable resin (cured by UV lamp etc.) consisting of a prepolymer having a radical polymerizable unsaturated group, a liquid vinyl monomer such as styrene and methyl methacrylate, and a photosensitizer, and Radically polymerizable prepolymer and a styrene having an unsaturated group, liquid vinyl monomer and an unsaturated polyester such as methyl methacrylate in,
Diacrylic phthalate, modified acrylic, modified epoxy,
Resins (cured by an electron beam generator, etc.) that can be polymerized by radiation such as electron beams composed of modified urethane and polyfunctional monomers, etc., and these can be used alone or as a mixture of several types.

The present invention dissolves these clarifying agents in organic solvents,
Examples of solvents that can be used are benzene, toluene,
Aromatic hydrocarbon solvent such as xylene, petroleum solvent such as gasoline and petroleum ether, ester solvent such as ethyl acetate and butyl acetate, ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, methylene chloride , Chlorinated hydrocarbon solvents such as trichlorethylene, alcohol solvents such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol and methyl cellosolve, and these solvents may be used alone or as a mixed solvent. The concentration of the clarifying agent dissolved in the organic solvent is 15% or more, and its viscosity is 80 cp.
s (using a centipoise, B-type viscometer, measured with a # 1 rotor at 60 rpm, the same applies hereinafter) and below are preferable. 15%
In terms of the following concentrations, the resin adhesion amount required for transparency cannot be obtained, and if it is 80 cps or more, penetration into the base paper is insufficient, the transparency effect is also insufficient, and the surface "shine" becomes large. There is.

Further, in the present invention, a curing agent, an optional colorant, a surfactant, a plasticizer and the like can be appropriately mixed and used in addition to the clarifying agent.

In the present invention, the clarifying agent-containing liquid thus prepared is applied to the base paper, but the object of the present invention can be achieved only by the coating method. That is, the difference in transparency between the convex pattern portion and the non-pattern portion is larger in the coating method than in the impregnation method, and this is the greatest feature of the present invention. Further, the coating amount needs to be equal to or less than the amount capable of filling the non-patterned portion.

The reason will be described based on the drawings. 1 and 2 are schematic views showing enlarged cross sections of a part of the base papers P and P'used in the present invention.

The base paper of FIG. 1 is, for example, a method of press-molding wet paper having a moisture content of about 50% on a paper machine with felt having a knitting pattern, or press-molding with two embossing rolls engraved with the pattern. It is manufactured by a treatment method or the like.

In addition, the base paper of FIG. 2 is a method in which a wet paper with a water content of about 15% that is hydrated on a paper machine or formed paper is pressed through an embossing roll and a counter roll with a flat surface by forming an uneven pattern. Etc. are manufactured.

The volumes of the convex pattern portions 1 and 1 ′ are V ₁ and V ₁ ′, the volume of the non-pattern portion 2 and 2 ′ of the same area as V ₂ and V ₂ ′, and V ₁ is a fiber of volume F ₁ . Void (equivalent to air) A ₁
Therefore, it is assumed that V ₁ ′ is formed by fibers of volume F ₁ ′ and void A ₁ ′. Further, it is assumed that V ₂ is formed by fibers of volume F ₂ and voids A 2, and V ₂ ′ is formed by fibers of volume F ₂ ′ and voids A 2 ′.

In the present invention, the amount of fibers in the thickness direction of the paper is substantially uniform, so that F ₁ ≈F ₂ and F ₁ ′ ≈F ₂ ′. Also, V ₁
> V ₂ , V ₁ ′> V ₂ ′.

A clarifier with a concentration of 30% (specific gravity 1) is added to this base paper.
In the convex portions 1 and 1 ', the clarifying agent fills the void volumes A ₁ and A ₁ '. Therefore, the adhering amounts of the clarifying agent after drying are 0.3A ₁ and 0.3A ₁ ', and similarly, the non-patterned portions 2 and 2'are 0.3A ₂ and 0.3A ₂ '. A ₁ ＞ A ₂ and
Since A ₁ ′> A ₂ ′, the amount of the transparentizing agent deposited on the convex pattern portion is larger than that on the non-pattern portion.

On the other hand, in the method of applying the clarifying agent, after drying,
When the amount of coating is 0.3A ₂ and 0.3A ₂ ′, the same amount (0.3A ₂ and 0.3A ₂
0.3A ₂ ′).

That is, according to the coating method, the resin adhesion amount of the convex pattern portion can be reduced by the impregnation method, and the contrast of transparency of the convex pattern portion and the non-pattern portion can be further emphasized. Therefore, in the present invention, the coating amount of the coating agent is preferably not more than the amount satisfying the void volumes A ₂ and A ₂ ′ of the non-patterned portion.

Actually, in the case of the impregnation method, since the base paper passes through the impregnating liquid in the impregnation tank, the clarifying agent is excessively supplied and tends to stay in the non-patterned portion. When it is dried, it becomes as if a resin film had been formed on the surface of the non-patterned portion, which causes a defect called "shining" in which a large amount of light is reflected at that portion. On the other hand, in the coating method, the necessary amount of the clarifying agent can be freely controlled in advance, so that this drawback can be reduced.

In particular, if a base paper with a convex pattern on only one side (schematically shown in FIG. 2) is used and coating is applied from the surface opposite to the convex surface (smooth surface), there will be no retention of the clarifying agent. "Shiritsu"
It is possible to manufacture design paper that has no

Further, in the impregnation method, the clarifying agent gradually accumulates on the guide rolls in the drying zone and dries, so that it is necessary to take measures against it, but in the coating method of the present invention, this problem hardly occurs. There are also great advantages.

Further, there is also an advantage that the transparency of the pattern portion and the non-pattern portion can be freely controlled by changing the coating amount.

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Papermaking of base paper 30 parts by weight of NBKP and 70 parts by weight of LBKP were mixed and beaten to 430 ml of CFS. Next, a sizing agent (trade name: Size Pine E,
Arakawa Hayashi Chemical Co., Ltd.) was added to the pulp solid content of 1%, and starch (trade name Amicol 602, Nippon Starch Co., Ltd.) was added to the pulp solid content of 1%, and the pH was adjusted to 4.5 with aluminum sulfate.

This slurry is made into paper by a Fourdrinier paper machine, dehydrated and then pre-dried, and when the water content is 15%, an embossing roll (the pattern on the cloth is formed by engraving to correspond to 25% of the total area) And linear pressure between counter rolls with flat surface
It was pressed at 0 kg / cm and dried to obtain a base paper having a basis weight of 100 g / cm ² .

Clarification treatment Clarifying agent combination prescription Polyacrylic acid ester-based resin (Tesfine 40
4, manufactured by Hitachi Chemical Polymer Co., Ltd.) 62 parts by weight Polyethylene glycol 5 〃 Toluene 28 〃 Methyl ethyl ketone 5 〃 (coating concentration 25% by weight, viscosity 60 cps) This solution is dried by a gravure roll coating machine to a solid weight of 10
The back surface (smooth surface) of the base paper was coated so as to have a g / m ² .

Comparative Example 1 The same base paper as listed in Example 1 was used, and the same clarifying agent as in Example 1 was used to impregnate using a horizontal type impregnator.

The opacity was measured according to JIS P-8139.

Example 2 Papermaking of base paper 30 parts by weight of NBKP and 70 parts by weight of LBKP were mixed and beaten to 350 ml of CFS. Next, a sizing agent (trade name: Size Pine E,
Arakawa Hayashi Chemical Co., Ltd.) was added to the pulp solid content of 1%, and starch (trade name Amicol 602, Nippon Starch Co., Ltd.) was added to the pulp solid content of 1%, and the pH was adjusted to 4.5 with aluminum sulfate.

This slurry is made into paper by a Fourdrinier paper machine, and the second dehydration step
With a press roll, use a coarse blanket (weaving thread thickness is 0.8 mm,
The blanket pattern was transferred onto a wet paper with a linear pressure of 100 kg / cm and dried according to a conventional method to obtain a base paper of 80 g / m ² .

Clarifying agent prescription Polyacrylic ester resin (trade name: Tesfine
404, manufactured by Hitachi Chemical Polymer Co., Ltd.) 75 parts by weight Toluene 25 〃 (paint concentration 30% by weight, viscosity 65 cps) This prescription liquid was applied by a roll coater to 8 g / m ² and dried.

Comparative Example 2 The same base paper as in Example 2 was impregnated with a clarifying agent having the same formulation as in Example 2 using a horizontal type impregnating machine.

C. Effects of the Invention The present invention is configured as described above and has the following effects.

The transparency of the convex pattern part is lower than that of the non-pattern part, and the contrast between the pattern part and the non-pattern part is excellent.

It is possible to obtain a design paper that does not have "shine" in the non-patterned portion.

Excellent productivity with no resin deposition on the guide rolls in the drying zone of the coating machine.

[Brief description of the drawings]

1 and 2 are schematic views showing cross sections of base papers P and P'used in the present invention. 1 and 1 'are convex pattern portions 2 and 2 of same area' V ₁ and V ₁ to the non-pattern portion 'convex pattern portions 1 and 1' V ₂ and V ₂ the volume of the 'non-pattern section 2 and 2'volume is shown.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-62-15398 (JP, A) JP-B-50-25048 (JP, B1)

Claims (2)

(57) [Claims] 1. A convex pattern and a non-patterned portion are provided on a base paper having a substantially uniform amount of fibers in the thickness direction, and a clarifying agent melted in an organic solvent is applied to a volume of the non-patterned portion or less. A design paper characterized by having a large difference in transparency between the convex and non-patterned areas by drying after processing. 2. The design according to claim 1, wherein the cardboard is provided with a convex pattern only on one side, and the transparentizing agent is applied from the surface (smooth surface) opposite to the convex surface. paper.