JP3518990B2 - Heat-sensitive stencil paper roll - Google Patents

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 which can prevent deterioration of the surface smoothness of the stencil sheet wound in a roll with time.

[0002]

2. Description of the Related Art A stencil sheet is formed by laminating an ink-permeable porous support such as Japanese paper and a thermoplastic resin film having a thickness of about 2 μm directly or with an adhesive to prevent sticking on the film surface. Manufactured by applying a release agent for. A thermal printing head (TPH) is used for plate making of the stencil sheet, but if unevenness is present on the surface of the stencil sheet, the contact state between the TPH and the film varies during the plate making, so that easily perforated and difficult to perforate. However, a perforation cannot be performed as in the original, and a good printed image cannot be obtained. For this reason, conventionally, a method has been adopted in which the surface smoothness of the stencil sheet is secured by using a porous support having excellent surface smoothness. Further, JP-A-8-67081 discloses a thermoplastic resin film in a state in which a porous support and a thermoplastic resin film are laminated in order to sufficiently contact with a 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 around a core of a paper tube or the like in a roll shape is often used to improve operability, so that a sheet-shaped stencil sheet is used. Even if the stencil sheet has excellent surface smoothness, when the stencil sheet is wound into a roll, the surface smoothness of the stencil sheet decreases with time due to rolling pressure, and the same surface smoothness as in the sheet state. There is a problem that can not be maintained. Such a decrease in the surface smoothness of the stencil sheet rolled into a roll is caused by the lapse of time when the portion of the film not supported by the porous support fibers is subjected to the winding pressure of the stencil sheet laminated in a roll shape. It is caused by the depression.

As a method for solving the above problem, there has been proposed a method of controlling the winding density of a roll to prevent the deterioration of the surface smoothness of the stencil sheet (JP-A-6-239048). However, only by adjusting the winding density of the roll, it is not possible to prevent deterioration of the smoothness of the stencil sheet when it is partially wound with a high pressure, particularly in the vicinity of the core of the roll. Further, if the winding pressure of the roll is loosened to avoid this, there arises a problem that the handleability as a product is deteriorated. Further, in JP-A-8-337069 or JP-A-8-337070, in order to prevent deterioration of image quality due to deterioration of surface smoothness, a stencil base paper having a specific compression elastic modulus is used, or a stencil base paper is used. It has been proposed to apply a calendar treatment to. However, such a method has a problem that a material used for the stencil sheet is restricted in order to obtain a specific compression elastic modulus, or the number of manufacturing steps is increased.

[0005]

The present invention solves the above-mentioned problems of the prior art and prevents deterioration of image quality due to deterioration of surface smoothness over time even when the heat-sensitive stencil sheet is wound into a roll. An object of the present invention is to provide a roll-shaped heat-sensitive stencil sheet that can be formed and can obtain a good printed image.

[0006]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of the above problems, and as a result, can solve the above problems by interposing a specific sheet between the base paper wound in a roll shape. The present invention has been achieved by finding the above. That is, the invention claimed in the present application is as follows. (1) In a roll-shaped heat-sensitive stencil sheet in which a thermoplastic resin film is laminated on a porous support, the roll-shaped heat-sensitive stencil sheet has a surface roughness of 8.0 μm. A roll-shaped heat-sensitive stencil sheet characterized in that the following sheets are interposed. (2) The roll-shaped heat-sensitive stencil sheet according to (1), wherein the sheet has a thickness of 2.0 to 200 μm.

The roll-shaped heat-sensitive stencil sheet according to the present invention is
A sheet is interposed between the raw papers wound into a roll. The sheet is wound together with the base paper when the base paper is wound into a roll. By interposing the sheet between the wound base papers, the load due to the winding pressure applied to the film surface is relieved, and the deterioration of the surface smoothness of the film surface is suppressed.

The sheet to be used in the present invention is not particularly limited, and, for example, waste paper, medium-quality paper, high-quality paper, coated paper, plastic sheet and the like can be used, and the surface roughness of the sheet is 8.0 μm. It is preferably not more than 5.0 μm, more preferably not more than 5.0 μm, still more preferably not more than 0.6 μm. When the surface roughness of the sheet on the side of the base paper which is in contact with the film surface exceeds 8.0 μm, the surface smoothness of the film surface overlapping with the sheet is likely to decrease with time. Here, the surface roughness means an average roughness Ra measured according to JIS B-0601. The thickness of the sheet is 2.0
˜200 μm, more preferably 2.0 to 150.0 μm. Sheet thickness is 2.0
If it is less than μm, it may be difficult to interpose a sheet between the base papers when it is wound into a roll, and the thickness is 200 or less.
If it exceeds μm, the diameter of the roll-shaped base paper becomes too large and the handleability may deteriorate.

The heat-sensitive stencil sheet used in the present invention is 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 thin, but is disadvantageous in terms of cost. Therefore, the film properties (thickness, melting point, heat shrinkage rate) that can be perforated by the thermal energy of the thermal head used. , Shrinkage stress, etc.) is preferably taken into consideration. A stretched polyester film is particularly preferable from the viewpoint of perforation sensitivity.

As the polyester, 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 0.1 to 10 μm, preferably 0.1 to 5.0 μm, more preferably 0.1 to 10 μm from the viewpoint of film forming stability and perforation property.
It is set to 3.0 μm. In addition, the thermoplastic resin film,
If necessary, a flame retardant, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a pigment, a dye, a fatty acid ester, an organic lubricant such as wax, or a defoaming agent such as polysiloxane may be added. Good.

The porous support is not particularly limited as long as it is a porous support that does not substantially have perforation when heated and allows ink to pass through during printing, and includes thin paper, paper making, non-woven fabric,
Textiles, screen gauze and the like can be used. As these materials, natural fibers such as Manila hemp, Kozo, Mitsumata and pulp, and synthetic fibers such as polyester, vinylon, nylon and rayon are used alone or in combination with 2
A mixture of two or more species can be used. The porosity of the porous support is preferably 5 to 80%, more preferably 5 to 50.
%, And more preferably 5 to 30%. If the porosity is too small, the ink permeability may be poor, and the printed image may be faint and the sharpness may be reduced. On the other hand, if the porosity is too large, the ink permeability increases, the printed image becomes blurred, and set-off easily occurs. Here, the porosity refers to a value, which is expressed as a percentage, of an area occupied by open pores existing in a certain area of the support when the porous support is observed two-dimensionally.

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 peeled off in the usual state where they are bonded and the perforation property of the film and the ink permeability are not impaired. May be adopted. Generally, an adhesive is used, but a porous support using synthetic fibers and a thermoplastic resin film may be heat-sealed and bonded together. Examples of the adhesive include vinyl acetate type, acrylic type, vinyl chloride vinyl acetate copolymer type, polyester type,
Urethane adhesives can be used. Further, a mixture of an ultraviolet curable adhesive such as a polyester acrylate, a urethane acrylate, an epoxy acrylate, a polyol acrylate or the like and a photopolymerization initiator may be used, and particularly, one containing a urethane acrylate as a main component. Is preferred. If necessary, other additives such as antistatic agents and lubricants 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 sheet (that is, the surface opposite to the surface of the porous support) to provide a stick-preventing layer for preventing sticking with a thermal head or the like. You can In this case, as the release agent, a silicone-based release agent, a fluorine-based release agent, a surfactant or the like can be used. Further, various additives such as antistatic agents, heat-resistant agents, antioxidants, organic particles, inorganic particles, pigments and the like may be added to the above composition within a range that does not impair the effects of the present invention. 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 effects on the human body. The thickness of the stick preventing layer is preferably 0.005 to 0.4 μm, more preferably 0.01 to 0.4 μm, from the viewpoints of running properties during punching, contamination of the thermal head, and the like.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. 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 A template was applied at 0.1 g / m ² to obtain a raw material for a heat-sensitive stencil sheet. Next, the surface roughness between the base paper is 5.0
A roll-shaped heat-sensitive stencil sheet was prepared so that a medium-quality paper having a thickness of 92 μm and a thickness of 92 μm (basis weight: 58.0 g / m ² ) was sandwiched and the winding pressure was 1.0 kg / cm ² . The wrapping pressure means the pressure applied to the base paper per unit area.

Example 2 The same as Example 1 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. To prepare a roll-shaped heat-sensitive stencil sheet. Example 3 A roll shape was prepared 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 165.0 g / m ² ) was sandwiched between the base papers. 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 a medium-quality paper was not sandwiched between the raw paper sheets. Comparative Example 2 A rolled heat-sensitive stencil sheet was prepared in the same manner as in Example 1 except that Washi paper having a surface roughness of 10.0 μm and a thickness of 55 μm (basis weight of 10 g / m ² ) was sandwiched between the stencil sheets. It was made.

After producing the roll-shaped heat-sensitive stencil sheets in Examples 1 to 3 and Comparative Examples 1 and 2, the roll-shaped heat-sensitive stencil sheets were stored in a high temperature tank at 30 ° C., and one day, one month and three months later, the respective stencil sheets were used. Plate-making printing machine (lithograph GR375,
Plate-making printing was carried out under the product name of Ideal Science Co., Ltd.). The image quality of the obtained printed matter was evaluated by visual judgment, and the results are shown in Table 1.
It was shown to. The surface roughness is based on JIS B-0601, and is based on Kosaka Laboratory Ltd. Surfcoder AY-4.
It was measured at 1.

[0019]

[Table 1] ◯: Printed image is good. Δ: Fine white spots (due to defective punching) occur in the printed image, but there is no problem in practice. X: Many white spots (due to defective punching) occur in the printed image, which is a problem in practical use.

From Table 1, it can be seen that the roll-shaped heat-sensitive stencil sheet of the present invention can obtain a good printed image even after being stored for a long period of time, and the deterioration of the surface smoothness of the stencil sheet is small. It is shown that the effect is improved by using a sheet having particularly low surface roughness. On the other hand, in Comparative Example 1 in which no sheet is interposed and Comparative Example 2 in which a sheet having a large surface roughness is interposed, a good printed image cannot be obtained after long-term storage, and the surface smoothness of the stencil sheet is deteriorated.

[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 rolled stencil sheets, the stencil sheet can be stored for a long period of time. It is possible to prevent deterioration of the surface smoothness of the base paper and obtain a good printed image.

Claims (2)

(57) [Claims] 1. A roll-shaped heat-sensitive stencil sheet obtained by winding a heat-sensitive stencil sheet on which a thermoplastic resin film is laminated on a porous support in a roll form, and a surface roughness of 8 is obtained between the roll-shaped heat-sensitive stencil sheet. A roll-shaped heat-sensitive stencil sheet having a sheet of 0.0 μm or less interposed. 2. The sheet has a thickness of 2.0 to 200 μm.
The roll-shaped heat-sensitive stencil sheet according to claim 1, wherein