JPH02241794A - Thermal screen printing base paper - Google Patents

Abstract

PURPOSE:To prevent the generation of coating irregularity by constituting the silicone oil of a coating layer containing a thermoplastic polymer and silicone oil of a mixture of two or more kinds of specific silicone oils and setting the content of said silicone oil to specific % by wt. of the coating layer. CONSTITUTION:In thermal screen printing base paper for thermal head writing wherein a coating layer containing a thermoplastic polymer and silicone oil is provided to one surface of a porous tissue material as a thermal screen printing layer, the silicone oil is composed of a mixture of two or more kinds of silicone oils represented by formulae I, II and contained in an amount of 0.1 - 10% by wt. of the whole of the coating layer. By this method, the thermal screen printing layer generating no coating irregularity can be formed and the excessive thermal welding of a thermal head and the thermal screen printing base paper at the time of digital plate making can be prevented without bringing about an increase of heat energy or manufacturing cost and high density printed matter excellent in resolving power can be obtained at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat-sensitive stencil paper for writing with a thermal head, which comprises a porous thin sheet material and a heat-sensitive stencil layer provided on one side thereof.

[Conventional technology]

Conventionally, the heat-sensitive stencil layer 4 has been manufactured by laminating a previously formed thermoplastic resin film and a porous thin material using an adhesive.

The heat-sensitive stencil paper produced by this method is 5. "The plate is made by heating and perforating a heat-sensitive stencil layer made of two resin films. During printing, this base paper is wrapped around an ink drum and ink is supplied from the porous thin material side. .

The thickness of such a heat-sensitive stencil layer °ζ is desirably as thin as possible; making it thinner increases plate-making accuracy, makes printing easier, and allows the use of high-viscosity ink for smearing. It is possible to print with high density and clarity, that is, high quality printing with good image quality.

However, the conventional heat-sensitive stencil paper mentioned above is made of thermoplastic resin film! ! There is a limit to how thin the heat-sensitive stencil layer can be made due to the use of film technology, so it can be expected to improve the quality of printing2.
It has been difficult to achieve a thickness of less than μm, for example about lpm.

In order to solve this problem, it has been proposed that the heat-sensitive stencil layer to be provided on the porous thin sheet material be made of a coating layer of a thermoplastic polymer, thereby making the film thinner. For example, in JP-A-61-67196 and JP-A-62-173296, a thermoplastic (Millimer solution) is applied onto a releasable temporary support, 1.: This is applied via an adhesive layer, Alternatively, it is disclosed that the image is transferred onto one surface of a porous thin sheet material without any intervention.

By constructing the heat-sensitive stencil layer with a coating layer of such a thermoplastic polymer, unlike the above-mentioned conventional method of using a pre-formed film, limitations such as film-forming technology can be avoided. Therefore, the thickness of the coating layer can be made considerably thinner, thereby making it possible to realize high-quality printing.

However, in digital plate making using thermal multihead writing, which has become popular recently, the above-mentioned thinning method 1. There was a problem in that the heat-sensitive stencil layer and the full head were excessively fused together, that is, stuck, resulting in deterioration of resolution.

For this reason, Japanese Unexamined Patent Publication No. 178788 and 60-9
As disclosed in Japanese Patent No. 7891, etc., a heat-resistant stick prevention layer that is solid at room temperature is provided on the stencil layer surface of the heat-sensitive stencil paper to prevent excessive heat fusion with the above-mentioned 49. Press the button to control 7. Measures are being taken to prevent resolution deterioration.

However, forming such a heat-resistant anti-stick layer that is solid at room temperature poses the problem of increased manufacturing costs due to the increased number of steps, and also requires low energy, or low energy, required during hot drilling. In heat capacity plate making, the formation of the above-mentioned preventive layer tends to result in insufficient perforation and a drop in print density, and to avoid this, it is necessary to increase the thermal energy during double plate making. There was a problem.

Also, Japanese Patent Application Laid-open No. 58-92595 and No. 61-102
As disclosed in Publication No. 294, it is also known to provide a stick prevention layer that is liquid at room temperature on the stencil layer surface of heat-sensitive stencil paper. Although there is no particular problem with thermal energy, the problem of increased manufacturing costs due to an increase in the number of manufacturing steps for forming the anti-stick layer is exactly the same as described above.

Therefore, in view of the above circumstances, the inventors conducted extensive studies and decided to make the heat-sensitive stencil layer of the heat-sensitive stencil paper consist of a coating layer made of a thermoplastic polymer mixed with a specific amount of silicone oil. Sometimes, excessive thermal adhesion between the thermal head and the heat-sensitive stencil layer is prevented by gradually bleeding the above-mentioned silicone oil onto the surface of the heat-sensitive stencil layer. I learned that there was no need to provide an additional anti-stick layer that would increase production costs, and that the above-mentioned silicone oil was liquid at room temperature, so it was possible to perform plate making using thermal RAD with low energy. has already been proposed as a prior invention of this invention.7 (Problem to be solved by the invention) However, according to subsequent research by the inventors, the heat-sensitive stencil paper according to the above-mentioned prior invention has low Although it is certainly possible to reduce energy platemaking and manufacturing costs, it is not possible to construct a heat-sensitive plate layer.
l Plastic polyester 7 ”””'-' l (+) Due to the silicone oil used by the person [-, +, uneven coating occurs j2
6. Due to this application, the number of printed sheets increased. li7.11
It turned out that there was a J-sexuality problem.

Therefore, the present invention further improves the above-mentioned prior invention and eliminates excessive heat fusion between the thermal layer and the heat-sensitive stencil layer without increasing the thermal energy during plate making or increasing the manufacturing cost. The purpose of this invention is to provide a heat-sensitive stencil paper that does not have problems with stiffness and prevents problems.

[Failure to solve the problem]

In order to achieve the above-mentioned object, this inventor et al., as a result of intensive study, have developed a heat-sensitive stencil layer by using a specific silicone compound mixed into a thermoplastic polymer. By applying the same method as in the prior invention, it is possible to form a heat-sensitive stencil layer without uneven coating.
4J--A heat-sensitive stencil paper that can prevent excessive heat fusion between the round head and the heat-sensitive stencil layer without increasing heat energy during plate-making or increasing manufacturing costs, and also has improved printing durability. I learned that it was possible to obtain a thermoplastic polymer and a silicone oil as a heat-sensitive stencil layer on one side of a porous thin sheet material. In the heat-sensitive stencil paper for thermal head writing, which is provided with a coating layer containing: R is an aralkyl group or an alkyl group having 6 to 24 carbon atoms, m, n
is an integer that satisfies 10≦ffl + n≦1,000,
The atomic groups in [ ] are randomly present in (). ) and/or the following formula ■; (wherein R is an aralkyl group or an alkyl group having 6 to 24 carbon atoms, m is an integer satisfying 10≦m≦1,000, and each is The silicone oil is composed of one or more silicone oils expressed as
．． The present invention relates to a heat-sensitive stencil paper having a weight of 1 to 10 weight.

[Structure and operation of the invention]

In this invention, the porous) W-leaf material is made of natural fibers such as Manila hemp, cocoon, and mitsumata, synthetic fibers such as polyester, polyimide, and non-woven fabrics made by mixing these materials with a basis weight of 5 to 15 g. /d, polyester fiber, navy blue screen gauze, etc.

The thermoplastic polymer applied to one side of this porous thin sheet material may be non-adhesive at room temperature and solid at room temperature in order to form a heat-sensitive stencil layer using this polymer, such as acrylic resin, One of the wide range of conventionally known polymers such as olefin resins and butyral resins.
One species or two or more species can be arbitrarily selected and used.

These polymers may be a single polymer or a copolymer, and may be -C, and the copolymer is random.

It may be either a block or a graft copolymer.1 The molecular weight of the polymer varies depending on its type, but
Generally the weight average molecular weight is 20.000 to 200.000
It is desirable that it be within the range of .

In this invention, particularly recommended polymers and 1° are:
There are thermoplastic polymers that have strong hydroxyl and/or carboxyl groups in their molecules, and by using such polymers, good results can be obtained in terms of printing sensitivity characteristics, stiffness resistance, etc.

The above hydroxyl group and/or carboxyl group may be present at the end of the molecule or at any position within the molecule (including the side chain).

Specific examples of thermoplastic polymers such as 2 and 2 include polyester resins, polyvinyl acetate resins, polyvinyl chloride resins, vinyl chloride 5-vinyl acetate copolymers, polyether resins, and polybutadiene resins. resin, acrylic polyol, polyvinyl butyral, hydroxyl group-containing I
/tan-based or epoxy-based prepolymers, nitrocellulose, cellulose acetate propionate resin, cellulose acetate-1/butyrate resin, ethyl cellulose 1, cellulose acetate, and the like.

In this invention, a mixture of the above-mentioned thermoplastic polymer and silicone oil is provided as a coating layer on one surface of the porous thin sheet material. The silicone oil used here is represented by the following formula I or formula One or more po-9 compounds selected from silicone oils.

<Formula ■> (In the formula, Y is -3t (CHih), R is an aralkyl group or an alkyl group having 6 to 24 carbon atoms, m, n is 1
Each represents an integer that satisfies 0≦rn + n≦1,000, and the atomic groups in [] are randomly present in (). ) (wherein, R is an acylkyl group or an alkyl group having 6 to 24 carbon atoms, and INN is 10≦m≦1,0
Each represents an integer that satisfies 00. ) The above formula■
The silicone oil represented by the formula (■) has a strongly lipophilic group (R) in its molecule, so it has good affinity with thermoplastic polymers and organic solvents, and this makes it heat-sensitive and allows for even coating. It is presumed that this helps in the formation of a stencil layer.

The number average molecular weight of these silicone oils is i, oo
o to ioo, ooo range, particularly preferably 3.000
A range of ˜50,000 is desirable. On the other hand, the content of this silicone oil is 0.1-10% by weight of the entire coated surface.
It should be particularly preferably 0.2 to 5% by weight. If it is less than 0.1% by weight, a sufficient stick prevention effect cannot be obtained, and if it exceeds 10% by weight, the perforation property may deteriorate. I can't get the desired result.

The above-mentioned silicone oil is liquid at room temperature, so it bleeds out to the surface of the coating layer and exhibits the above-mentioned stick prevention effect. Instead of this silicone oil, for example, silicone that is solid at room temperature may be used. If a resin or the like is used, sufficient bleed-out to the surface of the coating layer is not achieved, so a good stick prevention effect cannot be obtained, and furthermore, it is difficult to obtain good results in terms of perforation.

When forming a heat-sensitive stencil layer consisting of a coating layer containing such a thermoplastic polymer and silicone oil, first, the above thermoplastic polymer and silicone oil are mixed with hexane, benzene, toluene, xylene, ethyl acetate, methyl ethyl ketone, It is dissolved in one or more suitable organic solvents such as methyl isobutyl, and optionally contains various additives such as antioxidants, lubricants, plasticizers, and antistatic agents, if necessary. Prepare a polymer solution.

Next, this polymer solution is applied onto a temporary support and dried to form a coating layer. After 1°, this is adhered to one side of the porous thin sheet material via an adhesive layer, and then only the temporary support is peeled off. As a result, a heat-sensitive stencil layer consisting of a coating layer containing thermoplastic polyurethane (7) with an adhesive layer interposed therebetween and silicone oil is formed on one surface of the porous thin sheet material.

The adhesive used in the above adhesive layer can be appropriately selected according to the materials of the heat-sensitive stencil layer and the porous thin film material, and specific examples thereof include acid-resistant vinyl, polyvinyl,
Nylbutyral type, chlorobrene type, polyurethane type,
Examples include various adhesives such as polyacrylic adhesives.

The above adhesive layer contributes to improving the printing durability of the heat-sensitive stencil layer, but may be omitted depending on the case.
In the case of (1) where the adhesive layer is omitted, the method for forming the heat-sensitive stencil layer and 1. In addition to the above method, it is also possible to use a method in which the polymer solution is directly applied onto a porous thin sheet material filled with water and then dried.

The thickness of the coating layer as a heat-sensitive stencil layer obtained in this way is 2 gm or more, usually about 0.65 to 1.5 μm, and the thickness of the coating layer can be made as thin as this. In addition, plate making using a low energy layer, which is one of the objects of the present invention, becomes substantially possible.

〔Effect of the invention〕

As described above, in the heat-sensitive stencil paper Q of the present invention, the above-mentioned silicone oil is mixed into the thermal i'iff plastic bomber. 7) By using a thin material, it is possible to form a solid heat-sensitive stencil layer during coating I, and the process of digital stencil printing by thermal head writing on tY, as in the case of the prior invention, is possible. Excessive thermal adhesion between blue throat and heat-sensitive stencil paper can be prevented without increasing heat energy or manufacturing costs. 'J
It is possible to achieve the special effect of being able to achieve several pieces of rigidity in addition to being able to achieve the following:

〔Example〕

! ') l T describes the embodiments of this invention 1. 43. In addition, in the following 6, "parts" means parts by weight.
/ and) 9.8 parts of a thermoplastic polymer consisting of a copolymer (degree of polymerization 800) with a weight of 88812, R in formula I is -C:
H2CH(CI,)φ (φ is a phenyl group),
+1 is an integer such that m + n = , 30 ~ Temporary support made of poly 2R sterfil, which was released using finger liquid, had a coating weight of 1.5 after drying.
Apply it with a Mayer bar so that it is g/rd 7, and
By drying at 00'C for 1 minute, the film thickness becomes 1.2μ.
A coating layer of rri was formed.

Next, polyvinyl acetate resin (average degree of polymerization: 1°500
) An adhesive solution consisting of 90 parts of iO and 90 parts of toluene was applied onto the coating layer shown in L using a Mayer bar so that the coating amount after drying was 1 g/M. A porous thin film material made of Manila hemp thin film paper is laminated';
After drying at 10 (,)'C for 1 minute, the temporary support described in -F was peeled off.A heat-sensitive stencil paper was obtained.

Example 2 Silicone oil and silicone oil 17 in which R in formula I is a dodecyl group, and m and n are integers such that m + n = , 4 Q ~ 200 (amount io in several thousand equal parts).

A heat-sensitive stencil paper was obtained in the same manner as in Example 1 except that 0.2 part of 0.00) was used.

Example 3 As a silicone oil, R in the inlet is -CH2CH(
Example 1 except that 0.2 parts of α-methylstyrene-modified silicone oil (number average molecular weight 4,000) with m of 20 to 80 was used. A heat-sensitive stencil paper was obtained in the same manner.

Comparative Example 1 Thermoplastic polymer 1 consisting of a copolymer of vinyl chloride and vinyl acetate with a weight ratio of 88:12 (degree of polymerization 800)
0 parts 1, methyl ethyl ketone fi C1 parts, toluene 3
Using a polymer solution consisting of 0 parts (Example 1)
A heat-sensitive stencil sheet was obtained by straining in the same manner as above.

Comparative Example 2 Comparative Example I Silicone resin (trade name KS77 manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface of the heat-sensitive stencil layer of C18 heat-sensitive stencil paper.
2 and curing catalyst PL3) 10 parts Q”'s Kizan 90
A stick prevention coating liquid consisting of 4 parts was applied in an amount of 0.01 part 5 g 10 f after drying to form 4 stick prevention layers, and a heat-sensitive stencil paper was prepared. .

Comparative Example 3 9.9 parts of thermoplastic polymer consisting of a copolymer of vinyl chloride and vinyl acetate (degree of polymerization 800) with a weight ratio of 88812, silicone resin (trade name K S manufactured by Shin-Etsu Kahira Co., Ltd.)
A heat-sensitive stencil paper was obtained in the same manner as in Example 1, except that a polymer solution consisting of 772, 0.1 part of curing catalyst I) I, 3), 60 parts of methyl ethyl ketone, and 30 parts of toluene was used.

Comparative Example 4 A thermoplastic polymer consisting of a copolymer (degree of polymerization: 800) of vinyl chloride and vinyl acetate in a weight ratio of 18:12.9.
8 parts, polyphosphorus (Rusiloxa 2) (number average molecular weight 40
．． 000) 0.2 parts, methyl ethyl ketone/(50 parts,
A heat-sensitive stencil paper was obtained in the same manner as in Example 1 at t2 except that a poly7-solution containing 30 parts of toluene was used.

The heat-sensitive stencil sheets of Examples 1 to 3 prepared as described above and the heat-sensitive stencil sheets of Comparative Examples 1 to 4 were subjected to plate making using a thermal head using a thermal transfer recording type word processor. I checked the performance and looked at C. The results are shown in Table 1 below.

Table 1 also shows plate making 1. I tried printing using a stencil printer 1A9800 manufactured by Riso Kagakusha using the sample.
] In the samples of Examples 1 to 3 and Comparative Example 4, good printed matter with high density and excellent resolution was obtained, but in the samples of Comparative Examples 1 to 3, the resolution deteriorated or the print density decreased. There was a small amount left. Further, in the samples of Examples 1 and -3, no fogging was observed even after printing more than 1,000 sheets, whereas in the sample of Comparative Example 4, fogging occurred after 500 sheets were printed.

From these results, it is clear that the heat-sensitive stencil paper according to the present invention is excellent in all of the properties of stickability, perforation of the stencil layer, and rigidity resistance.

Claims (1)

[Claims] (1) In a heat-sensitive stencil paper for thermal head writing, which has a coated layer containing a thermoplastic polymer and silicone oil as a heat-sensitive stencil layer on one side of a porous thin sheet material, the silicone oil described above has the following formula: I; <Formula I> ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, Y is -Si(CH_3)_3, R is an aralkyl group or an alkyl group with 6 to 24 carbon atoms, m, n
each means an integer satisfying 10≦m+n≦1,000, and the atomic groups within ( ) are randomly present within ( ). ) and/or the following formula II; <Formula II> ▲ Numerical formulas, chemical formulas, tables, etc. 1,000, respectively.
A heat-sensitive stencil paper characterized in that the content is 0% by weight.