JPH11321148A - Roll-form heat-sensitive stencil original paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll-form heat-sensitive stencil original paper which can prevent the image property from reducing due to the reduction of the surface smoothness with time even when the heat-sensitive stencil original paper is wound into a roll-form, and by which a favorable printed image can be obtained. SOLUTION: For this roll-form heat-sensitive stencil original paper, a heat- sensitive stencil original paper wherein a thermoplastic resin film is laminated on a porous supporting body is wound into a roll-form. In this case, a sheet of which the surface roughness is 8.0 μm or less is inserted between the original paper of the roll-form heat-sensitive stencil original paper. The thickness of the sheet is 2.0-200 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll-shaped heat-sensitive stencil sheet, and more particularly to a roll-shaped heat-sensitive stencil sheet capable of preventing the surface smoothness of a stencil sheet wound in a roll form from decreasing over time.

[0002]

2. Description of the Related Art A stencil sheet is obtained by laminating an ink-permeable porous support such as Japanese paper on a thermoplastic resin film having a thickness of about 2 μm, directly or via an adhesive, and further preventing sticking on the film surface. It is manufactured by applying a release agent for A thermal printing head (TPH) is used to make a stencil sheet. However, if there is unevenness on the surface of the stencil sheet, the state of close contact between the TPH and the film during stencil production will vary, so that the stencil sheet is easily pierced and hard to be pierced. However, perforations as in the original document cannot be performed, and a good printed image cannot be obtained. For this reason, conventionally, a method of securing the surface smoothness of the stencil paper using a porous support having excellent surface smoothness has been adopted. Japanese Patent Application Laid-Open No. 8-67081 discloses that a thermoplastic resin film in a state in which a porous support and a thermoplastic resin film are laminated in order to sufficiently contact the thermal head and obtain good perforation sensitivity. A heat-sensitive stencil sheet having a specified surface roughness and smoothness has been proposed.

However, in recent stencil printing, a roll-shaped stencil sheet wound in a roll shape around a winding core of a paper tube or the like is often used to improve operability. Even when the stencil sheet is excellent in surface smoothness, when the stencil sheet is wound into a roll, the surface smoothness of the stencil sheet decreases with time due to the winding pressure, and the same surface smoothness as in the sheet state Is not maintained. Such a decrease in the surface smoothness of the stencil paper wound in a roll shape is caused by the fact that the portions of the film not supported by the porous support fibers are subjected to the wrapping pressure of the stencil paper rolled up in a roll form over time. This is caused by indentation.

As a method for solving the above problem, a method has been proposed in which the winding density of a roll is adjusted to prevent the surface smoothness of the stencil sheet from lowering (Japanese Patent Laid-Open No. 6-239048). However, simply adjusting the winding density of the roll does not prevent a decrease in the smoothness of the stencil sheet when the roll is partially wound with a high pressure, especially near the core of the roll. Further, if the winding pressure of the roll is reduced to avoid this, there arises a problem that the handleability as a product is reduced. Further, JP-A-8-33769 or JP-A-8-337070 discloses that a stencil sheet having a specific compression modulus is used or a stencil sheet is used in order to prevent a decrease in image quality due to a decrease in surface smoothness. It has been proposed that a calendar process be performed. However, such a method has a problem that the material used for the stencil paper is restricted in order to obtain a specific compression elastic modulus, or the number of manufacturing steps is increased.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and prevents the deterioration of image quality due to the deterioration of surface smoothness over time even when the heat-sensitive stencil paper is wound into a roll. An object of the present invention is to provide a roll-shaped heat-sensitive stencil sheet capable of obtaining a good printed image.

[0006]

Means for Solving the Problems In view of the above problems, the present inventors have made intensive studies and found that the above problem can be solved by interposing a specific sheet between a base paper wound in a roll shape and the base paper. And have reached the present invention. That is, the invention claimed in the present application is as follows. (1) A heat-sensitive stencil sheet obtained by winding a heat-sensitive stencil sheet obtained by laminating a thermoplastic resin film on a porous support in the form of a roll has a surface roughness of 8.0 μm between the base sheets of the heat-sensitive stencil sheet. A roll-shaped thermosensitive stencil having the following sheet interposed: (2) The roll-shaped thermosensitive stencil sheet according to (1), wherein the thickness of the sheet is 2.0 to 200 μm.

[0007] The roll-shaped heat-sensitive stencil paper of the present invention comprises:
A sheet is interposed between the base paper wound in a roll shape. The sheet is wound together with the base paper when the base paper is wound into a roll. Since the sheet is interposed between the wound base paper and the base paper, the load due to the winding pressure applied to the film surface is reduced, and a decrease in the surface smoothness of the film surface is suppressed.

[0008] The sheet used in the present invention is not particularly limited, and for example, it is possible to use waste paper, medium quality paper, high quality paper, coated paper, plastic sheet, etc., and the surface roughness of the sheet is 8.0 µm. It is preferably at most 5.0 μm, more preferably at most 0.6 μm. If the surface roughness of the sheet on the side in contact with the film surface of the base paper exceeds 8.0 μm, the surface smoothness of the film surface overlapping with the sheet tends to decrease with time. Here, the surface roughness refers to an average roughness Ra measured according to JIS B-0601. The thickness of the sheet is 2.0
It is preferably from 200 to 200 μm, more preferably from 2.0 to 150.0 μm. 2.0 sheet thickness
If it is less than μm, it may be difficult to interpose the sheet between the base papers when it is wound into a roll, and the thickness may be less than 200 μm.
If it exceeds μm, the diameter of the rolled base paper may be too large, and the handleability may be reduced.

The heat-sensitive stencil sheet used in the present invention can be obtained by laminating a thermoplastic resin film on a porous support. There is no particular limitation on the thermoplastic resin film,
For example, polyester, polyamide, polypropylene,
Polyethylene, polyvinyl chloride, polyvinylidene chloride,
Conventionally known polymers such as other polymers are used. A thermoplastic resin film is advantageous in terms of sensitivity when the thickness is small, but disadvantageous in terms of cost. Therefore, the film properties (thickness, melting point, heat shrinkage) that can be perforated by the thermal energy of the thermal head used are , Shrinkage stress, etc.). From the viewpoint of perforation sensitivity, a stretched polyester film is particularly preferred.

Examples of the polyester include polyethylene terephthalate, a copolymer of ethylene terephthalate and ethylene isophthalate, polyethylene-2,6-naphthalate, polyhexamethylene terephthalate, and a copolymer of hexamethylene terephthalate and 1,4-cyclohexane dimethylene terephthalate. A polymer or the like can be used. From the viewpoint of improving the perforation sensitivity, a copolymer of ethylene terephthalate and ethylene isophthalate and a copolymer of hexamethylene terephthalate and cyclohexane dimethylene terephthalate are particularly preferably used.

The thickness of the thermoplastic resin film is usually from 0.1 to 10 μm, preferably from 0.1 to 5.0 μm, more preferably from 0.1 to 5.0 μm, from the viewpoint of film forming stability and perforation.
3.0 μm. The thermoplastic resin film also has
If necessary, a flame retardant, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, an organic lubricant such as a pigment, a dye, a fatty acid ester, a wax, or an antifoaming agent such as a polysiloxane may be blended. Good.

The porous support is not particularly limited as long as it has substantially no perforation during heating and is porous so that the ink can pass through at the time of printing.
A woven fabric, screen gauze, or the like can be used. As these materials, natural fibers such as manila hemp, mulberry, mitsumata, and pulp, and synthetic fibers such as polyester, vinylon, nylon, and rayon are used.
A mixture of more than one species can be used. The porosity of the porous support is preferably 5 to 80%, more preferably 5 to 50%.
%, More preferably 5 to 30%. If the porosity is too small, the ink permeability is poor, and the printed image may be blurred and the sharpness may be reduced. On the other hand, if the aperture ratio is too large, the permeability of the ink is increased, and the printed image becomes blurred, and the set-off becomes easy. Here, the porosity refers to a value expressed as a percentage of the area occupied by the pores existing in a certain area of the porous support when the porous support is observed in a plan view.

As a method for laminating the thermoplastic resin film and the porous support, any method can be used as long as the two are not separated from each other in a normal state where they are laminated, and the perforation of the film and the permeability of the ink are not hindered. May be adopted. In general, an adhesive is used, but a porous support using a synthetic fiber and a thermoplastic resin film may be bonded by heat fusion. Examples of the adhesive include vinyl acetate, acrylic, vinyl chloride-vinyl acetate copolymer, polyester,
Urethane-based adhesives can be used. Further, a UV-curable adhesive, for example, a mixture of a polyester-based acrylate, a urethane-based acrylate, an epoxy-based acrylate, a polyol-based acrylate, and a photopolymerization initiator may be used. Is preferred. If necessary, other additives such as an antistatic agent and a lubricant may be added to the adhesive.

Further, a release agent is applied to the surface of the thermoplastic resin film of the heat-sensitive stencil paper (that is, the surface opposite to the surface of the porous support) to provide a stick prevention layer for preventing stick with a thermal head or the like. Can be. In this case, as the release agent, a silicone release agent, a fluorine release agent, a surfactant or the like can be used. The composition may contain various additives such as an antistatic agent, a heat-resistant agent, an antioxidant, organic particles, inorganic particles, pigments, and the like, as long as the effects of the present invention are not impaired. Further, the coating liquid is preferably a coating liquid dissolved in water or an emulsified or suspended coating liquid in consideration of environmental pollution and influence on the human body. The thickness of the stick prevention layer is preferably from 0.005 to 0.4 μm, more preferably from 0.01 to 0.4 μm, from the viewpoint of the running property at the time of perforation and the contamination of the thermal head.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 A polyester film having a thickness of 2 μm and a basis weight of 10.5 g /
Manila hemp 60% m ^2, and a thin paper that混抄40% polyester fibers, after bonding via a polyvinyl acetate resin solids 0.8 g / m ² in the coating amount, a silicone-based release on the surface of the polyester film The mold was applied at 0.1 g / m ² to obtain a heat-sensitive stencil sheet. Next, a surface roughness of 5.0 between base papers
A medium-sized paper having a thickness of 92 μm and a thickness of 92 μm (basis weight: 58.0 g / m ² ) was sandwiched, and a roll-shaped heat-sensitive stencil sheet was prepared so that the winding pressure was 1.0 kg / cm ² . The winding pressure refers to the pressure applied to the base paper per unit area.

Example 2 The procedure of Example 1 was repeated, except that NPI-coated paper having a surface roughness of 0.6 μm and a thickness of 84 μm (basis weight of 104.7 g / m ² ) was sandwiched between the base papers. Thus, a roll-shaped heat-sensitive stencil sheet was prepared. Example 3 In the same manner as in Example 1, except that a chrome color paper having a surface roughness of 0.3 μm and a thickness of 153 μm (basis weight of 165.0 g / m ² ) was sandwiched between the base papers, the roll shape was the same. A heat-sensitive stencil sheet was prepared.

Comparative Example 1 A roll-shaped heat-sensitive stencil sheet was prepared in the same manner as in Example 1 except that no medium paper was sandwiched between the base papers. Comparative Example 2 A roll-shaped thermosensitive stencil sheet was prepared in the same manner as in Example 1 except that Japanese paper having a surface roughness of 10.0 μm and a thickness of 55 μm (basis weight 10 g / m ² ) was sandwiched between the base papers. Produced.

After preparing roll-shaped thermosensitive stencil sheets in Examples 1 to 3 and Comparative Examples 1 and 2, they were stored in a high-temperature bath at 30 ° C., and one day, one month and three months later, the respective stencil sheets were used. Plate making printing machine (Risograph GR375,
Plate-making printing was performed using Riso Kagaku Kogyo Co., Ltd.). The image quality of the obtained printed matter was evaluated by visual judgment, and the results were shown in Table 1.
It was shown to. The surface roughness is based on JIS B-0601 and is measured by Kosaka Laboratory Ltd. Surfcoder AY-4.
Measured at 1.

[0019]

[Table 1] ：: good printed image △: fine white spots (due to poor perforation) appear in the printed image, but no practical problem ×: many white spots (due to poor perforation) appear in the printed image, causing practical problems

From Table 1, it can be seen that the roll-shaped heat-sensitive stencil sheet of the present invention can provide a good printed image even after long-term storage, and the surface smoothness of the stencil sheet is less reduced. In particular, it is shown that the effect is improved by using a sheet having a low surface roughness. On the other hand, in Comparative Example 1 in which a sheet is not interposed and Comparative Example 2 in which a sheet having a large surface roughness is interposed, a good printed image cannot be obtained when stored for a long period of time, and the surface smoothness of the stencil sheet is reduced.

[0021]

According to the roll-shaped heat-sensitive stencil sheet of the present invention, since a sheet having a specific surface roughness is interposed between the roll-shaped stencil sheets, even if the stencil sheet is stored for a long period of time. A reduction in the surface smoothness of the base paper can be prevented, and a good printed image can be obtained.

Claims (2)

[Claims] A heat-sensitive stencil sheet obtained by winding a heat-sensitive stencil sheet obtained by laminating a thermoplastic resin film on a porous support in the form of a roll, wherein the surface roughness of the heat-sensitive stencil sheet between the base sheets is 8 Roll-shaped thermosensitive stencil paper characterized by interposing a sheet having a thickness of not more than 0.0 μm. 2. The sheet has a thickness of 2.0 to 200 μm.
The heat-sensitive stencil sheet in roll form according to claim 1, characterized in that: