JPS62253492A - Film for heat sensitive mimeograph print stencil paper - Google Patents

Abstract

PURPOSE:To provide a film for heat sensitive mimeograph print stencil paper where character and solid printings can be performed clearly with uniform thickness of character while the solid printing can be performed with good correspondence of size and different shade by incorporating a specific polyester having a fusion energy in a specific range into a double axes developing film containing a specific wax in a specific amount. CONSTITUTION:A double axes developing film where 0.005-5wt% of at least one type of wax mainly composed of higher fatty monocarboxylic acid having the carbon atomic number of 10-33 or a compound of its ester is contained in 100wt% of polyester is employed. If the crystal fusion energy of said film is lower than 3cal/g, it will cause sticking to the atoms and a clear character print can not be obtained while when said energy exceeds over 11cal/g, it will cause low sensitivity and a deteriorated expression of shade in the solid printing thereby the crystal fusion energy must be 3-11cal/g. When such heat sensitive film is sticked onto a porous supporting material, a heat sensitive mimeograph print stencil paper can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a film for thermal stencil printing base paper that is perforated by receiving heat from a xenon flash lamp, a thermal head, or the like. The principle of this plate-making method is described in, for example, Japanese Patent Publication No. 41-7623, Japanese Patent Application Laid-Open No. 55-103957, and Japanese Patent Application Laid-open No. 59-1436.
This refers to a well-known method described in Publication No. 79 and the like.

[Prior art] As a base paper for heat-sensitive stencil printing, a film for heat-sensitive stencil printing and a porous support bonded together with an adhesive is usually used. , vinylidene chloride copolymer film, polypropylene film, and polyethylene terephthalate film have been used, and as the porous support, tissue paper, Tetron gauze, etc. have been used.

In addition, as shown in Japanese Patent Publication No. 60-1198, a structure in which two types of polymers with melting points or softening temperatures different by 2°C or more are arranged mutually in the width direction of the film has been proposed. Ta.

[The problem that the invention aims to solve] However, these had the following drawbacks.

1) When a vinyl chloride or vinylidene chloride copolymer film is used as a film for heat-sensitive stencil printing base paper, the printed characters do not appear clearly.

2) With polypropylene and polyethylene terephthalate films, clear characters can be obtained, but solid printing (・
Symbols or figures such as or ■ that have a large area of ink adhesion are hereinafter referred to as solid printing.

) cannot obtain a clear image.

3) Also, the thickness of characters becomes uneven in some parts, and the size correspondence in solid printing becomes poor.

4) Sensitivity is poor for text and solid printing.

5) It is not suitable for printing photographs, etc. because it does not express shading when printing solidly.

6) After perforation, the document and the thermal stencil printing base paper film fuse together, so it cannot be used unless coated with a release agent or the like.

The present invention solves the above-mentioned drawbacks, and has clear text and solid printing, no uneven thickness of characters, good size compatibility in solid printing, good sensitivity for both characters and solid printing, and It is an object of the present invention to provide a film for heat-sensitive stencil printing base paper that can express shading and can be released from a document without using a release agent or the like.

[Means for Solving the Problems] 100 parts by weight of polyester is mixed with at least one type of wax whose main constituent is a higher aliphatic monocarboxylic acid having 10 to 33 carbon atoms, or a compound consisting of an ester thereof. 005 to 5 parts by weight, the film for thermal stencil printing base paper is characterized in that the film has a crystalline melting energy of 3 to 1 lcal/g.

As mentioned above, the heat-sensitive stencil printing atom in the present invention is one that is perforated by receiving heat from a xenon flash lamp, a thermal head, etc., and is made by laminating a heat-sensitive stencil printing base paper film and a porous support. It is something.

The present invention is an improvement of the film used for this base paper for heat-sensitive stencil printing (hereinafter simply referred to as heat-sensitive film).

The polyester in the present invention is a polyester containing an aromatic dicarboxylic acid as a main acid component and an alkylene glycol as a main glycol component.

Specific examples of aromatic dicarboxylic acids include terethalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid, anthracene dicarboxylic acid, α , β-bis(2-chlorophenoxy)ethane-4,4′-dicarboxylic acid, and the like. Among these, terephthalic acid is particularly desirable.

Specific examples of alkylene glycol include ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, hexylene glycol, and the like. Among these, ethylene glycol is particularly desirable.

Of course, these polyesters are copolyesters (
Examples of copolymerized components include diethylene glycol, propylene glycol, neopentyl glycol, polyalkylene glycol, oxylylene glycol, 1,4-cyclohexane dimetatool, and 5-sodium sulfonate. Diol components such as resorcinol, adipic acid, sebacic acid,
Dicarboxylic acid components such as phthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 5-sodium isophthalic acid, polyfunctional dicarboxylic acid components such as trimellitic acid and pyromellitic acid, and oxycarboxylic acid components such as p-oxyethoxybenzoic acid. Examples include acid components.

Note that, of course, the above polyester contains known additives,
For example, antistatic agents, heat stabilizers, ultraviolet absorbers, and the like may be added in amounts that do not impair the effects of the present invention.

The heat-sensitive film of the present invention needs to be biaxially stretched, and -axially stretched or unstretched film will cause uneven perforation.
Missing parts occur even after printing. Although the degree of biaxial stretching is not particularly limited, those having a plane orientation coefficient of 0.90 to 0.98 are preferred for the present invention.

Further, the crystal melting energy (ΔHu) (hereinafter simply referred to as ΔHu) of the heat-sensitive film is 3 to 11 Ca1/g. Preferably it is 5 to Local/g. If it is less than 3 Cal/g, it will stick to the base paper (manuscript) and it will not be possible to print clear characters. In addition, when △Hu is 5 Cal/(1 or more, clearer character printing is possible. Also, △
For those with Hu exceeding 11 Cal/IJ, solid printing,
Sensitivity and density expressivity (hereinafter referred to as sensitivity) are poor, and the object of the present invention cannot be obtained. In addition, ΔHu
When it is less than Local/g, it is possible to shorten the drilling time and improve productivity.

Further, the heat-sensitive film of the present invention preferably has a film thickness of 0.2 μm to 5 μm, more preferably 0.3 μm to 4 μm.

If the thickness is less than 0.2 μm, it will be difficult to bond it to the porous support, and the number of sheets to be printed will also decrease, which will be described later. Also, 5
If it exceeds .mu.m, there is a problem in improving sensitivity, and missing characters are likely to occur.

In the present invention, the compound whose main component is a higher aliphatic monocarboxylic acid having 10 to 33 carbon atoms includes, as specific examples, capric acid, lauric acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, and melisic acid. , nonadecanoic acid, cerotic acid, montanic acid, hentriacontanoic acid,
Examples include petroselic acid, oleic acid, erucic acid, linoleic acid, and acid mixtures containing these. Among these, higher aliphatic monocarboxylic acids preferably have 18 to 33 carbon atoms, more preferably 20 to 32 carbon atoms,
Preferred in terms of sensitivity and shading expression of characters and solid printing.

The higher aliphatic monocarboxylic acid ester in the present invention refers to the above-mentioned higher aliphatic monocarboxylic acid having 2 to 2 carbon atoms.
It is obtained by esterifying part or all of it with a monohydric or dihydric alcohol having 33. Specific examples include ethylene glycol montanate, ethyl montanate, ceryl montanate, octacosyl lignocerate, myricyl cerotate, seryl cerotate, and naturally occurring montan wax, carnauba wax, and beeswax. Candelilla wax, Nuka wax, Ibota wax, etc. are also preferably used.

In the present invention, the main component refers to a compound containing 50% by weight or more of the compound.

In the present invention, when the number of carbon atoms in the higher aliphatic monocarboxylic acid is less than 10, bleed-out to the film surface is severe and the adhesion to the porous support is extremely poor, and when the number of carbon atoms exceeds 33, The sensitivity of solid printing becomes poor and shading cannot be expressed.

In the present invention, as for the ester consisting of a higher aliphatic carboxylic acid and an alcohol, the number of carbon atoms of the acid and the alcohol constituting the ester are preferably 18 to 3.
The esters obtained by combining 3, more preferably 20 to 32 are desirable because they can improve solid printing sensitivity and provide good shading expression.

In the present invention, the content of at least one compound consisting of a higher aliphatic monocarboxylic acid and its ester (hereinafter referred to as a specific wax) must be 0.005 to 5 parts by weight per 100 parts by weight of the polyester. The amount is preferably 0.01 to 3 parts by weight. The above content is 0.00
If the amount is less than 5 parts by weight, not only will there be no effect of preventing fusion with the original, but there will also be no improvement in solid printing sensitivity, and shading cannot be expressed. Moreover, if it exceeds 5 parts by weight, bleed-out to the film surface becomes severe and adhesiveness with the porous support is lost, making it unusable for this purpose.

Further, the heat-sensitive film of the present invention preferably has a heat shrinkage rate of 5 to 50% at 150° C. for 15 minutes.

More preferably it is 8 to 40%.

If it is less than 5%, the sensitivity will be poor for both text and solid printing. Moreover, if it exceeds 50%, curling will occur after perforation, resulting in uneven thickness when printing characters.

The heat-sensitive film of the present invention may be multilayered (two or more layers), as long as it satisfies this required value in the JW structure. Furthermore, an additive having an absorption peak in the wavelength range of flash irradiation may be added to the heat-sensitive film of the present invention. In order to improve the adhesion to the porous support, the surface of the heat-sensitive film may be subjected to a corona discharge treatment in air, carbon dioxide gas, nitrogen gas, or a mixed gas thereof.

Furthermore, by incorporating inert particles into the heat-sensitive film of the present invention, 0.001 to 2 parts by weight, preferably 0.002 to 1 part by weight, based on 100 parts by weight of polyester,
The slipperiness of the film can be further improved, and the density expression can also be further improved.

The inert particles referred to here are those from the Periodic Table of Elements A and RI.
B, ■ A, NB particles selected from oxides or inorganic salts of group elements, such as calcium carbonate, wet silica (silicon dioxide), dry silica (silicon dioxide), which are obtained as synthetic or natural products. Examples include aluminum silicate (kaolinite), barium sulfate, calcium phosphate, talc, titanium dioxide, aluminum oxide, aluminum hydroxide, calcium terephthalate, calcium silicate, and the like.

Further, it is preferable that the average particle diameter of the inert particles is 0.1 to 3 μm, preferably 0.1 to 2 μm, since the slipperiness and density expressivity of the film are improved.

[Manufacturing method] Next, a method for manufacturing the heat-sensitive film of the present invention will be described.

The heat-sensitive film of the present invention is obtained by blending the above-mentioned polyester copolymer or copolymer with homogeneous polyethylene terephthalate, etc., and feeding this resin with a specific wax added to an extruder. , extrusion, T-die or inflation casting, followed by biaxial stretching.

This biaxial stretching is performed at a temperature higher than the glass transition temperature (Tg) (hereinafter referred to as Tg) and within the range of (Tg + 50'C), and at a stretching ratio within the range of 2.0 to 7.0 times (longitudinal direction , both in the width direction).

Furthermore, this film was (melting point -10°C) to (melting point -1
The heat-sensitive film of the present invention can be obtained by heat treatment within the range of 20°C.

The method of biaxial stretching is not particularly limited, but it can be obtained by using sequential biaxial stretching or simultaneous biaxial stretching (stenter method, tube method, etc.).

A heat-sensitive stencil printing base paper is obtained by laminating the heat-sensitive film thus obtained with a porous support.

[Applications] The film for heat-sensitive stencil printing base paper of the present invention thus obtained is particularly preferable for use in -a for heat-sensitive stencil printing, as well as for use in perforation and printing using flash irradiation, a thermal head, or the like.

[Method of Measuring Characteristics and Method of Evaluating Effects] Each characteristic used in the present invention was evaluated by the following method.

(1) Crystal melting energy [Δu (Cal/g)
] was determined from the area of the heat-sensitive film when it was melted using a DSC-2 model manufactured by PERKIN ELHER.

This area is the area that shifts from the baseline to the endothermic side as the temperature rises, and returns to the baseline position when the temperature continues to rise, and is the area from the melting start temperature position to the end temperature value! The area (a) was determined by connecting the areas with a straight line.

Measure In (indium) under the same DSC measurement conditions,
The area (b) was determined as 6.8 cal/g using the following formula.

a/b The porous support and the heat-sensitive film of the present invention (same as in Examples and Comparative Examples) were laminated together using a "RISO Business Card Pretend" plate making and printing machine (
The plate was made using Riso Kagaku Kogyo Co., Ltd., and the printed material was evaluated as follows.

Evaluation is done with the naked eye in three grades: A, R, and C. A is for items that look similar to the original paper, and B is for items that differ from the original paper in that the lines are partially cut or stuck together, but are cut to the point where they are unreadable. means.

■Evaluation of character thickness unevennessUsing the same plate making and printing machine as in section■, character size 5.
M characters were printed, and the printing condition was evaluated with the naked eye.

Characters whose thickness is clearly uneven compared to the characters on the original paper (manuscript) and are unreadable are marked with an "X" as unusable, and characters with uneven thickness but legible and usable are marked with a Δ. The O mark indicates that the thickness is completely uniform.

■ Character printing sensitivity evaluation Pencil hardness 7H, 6H, 5H, 4H, 3H, 2H.

Seven types of manuscripts (G) and (3) were prepared, and characters were written with a pressure of 150 g as manuscripts. Using these manuscripts, evaluation was made on whether or not the characters were legible. When written at 7H, the colors are the lightest and the sensitivity is the best, and as the color increases to H, the black becomes darker and the sensitivity deteriorates.

(3) Evaluation of solid printing ■ Evaluation of the sharpness of solid printing ・Using the base paper of 1 to 5 in order of 2 (circles filled with black inside), the same plate making and printing as above were performed as follows. It was evaluated as follows.

Judgment was made based on the unevenness (partial) of the outline using the size of the base paper as a standard. Items with unevenness of 200 μm or more than the size of the base paper are marked with an X, indicating poor appearance and unclear, and items with unevenness of 50 μm or less are marked with a circle, indicating that they are clear. The intermediate value is indicated by Δ. Depending on the usage, even those marked with Δ can be used.

■ Compatibility with base paper size for solid printing Print in the same way as in item 0, and print in all directions (0 and 180°, 45° and 225°, 90° and 270°, 135° and 315° -
The size of the paper was evaluated, and the correspondence of the size with the size of the base paper was evaluated. If the difference is 500 μm or more compared to the base paper size (sometimes it is very large, sometimes it is small), it is considered to have good compatibility and is marked with an O symbol. The one in between is indicated by Δ,
It can be used depending on the purpose.

■ Evaluation of sensitivity of solid printing and expressiveness of shading "Macbeth" reflection densitometer, RD-918 (kol1morgen
Density was measured by a company (Japan, USA), and the solid print density of the manuscript was compared with the density after plate making and printing.

First, the concentration is 0.90, 0.50, 0.3 using the densitometer mentioned above.
A manuscript with a solid print of 15 mm opening was prepared so as to have a size of 5.0.20. Next, using this manuscript, plate making was carried out in the same manner as described above.
Printed.

This printed material was measured using the densitometer described above, and the sensitivity for each density was determined using the following formula.

Sensitivity for each density = Density after printing for each density / Original density for each density When all the sensitivities for each density are 0.8 or higher, the sensitivity and expressibility of shading is good, which is indicated by an ◎ mark, and 0°7 or higher. Those less than 0.8 were marked with an X, indicating that the sensitivity and density expression were poor. The sensitivity for each concentration is when all are satisfied, and when even one is poor, it is ranked lower.

(4) Heat shrinkage rate Sample the film to a width of ICm and a length of 30 Cffl, mark a position 5 Cffl from one end of the film, and further mark a position 20 Cffl from there.

A load of 3 g was applied to the tip of this film, and Tabai Co., Ltd.
After processing for 15 minutes at 150° C. in the "Perfect Oven" produced by the company, the intermediate length attached to the film was measured (length after processing) and calculated from the following formula.

20 (cm) (5) Adhesiveness Refers to the adhesion between Tetron gauze used as a porous support and a heat-sensitive film. Sellotape was attached to each surface and peeled off for evaluation.

If the Tetron gauze is completely peeled off, it is considered as insufficient adhesive strength.
If it does not come off at all, it is considered to have sufficient adhesive strength and is marked Q.
Indicated with a mark. Although it partially peels off.

is indicated by a Δ mark.

(6) Release property refers to the peelability between the manuscript after plate making and the base paper for thermal stencil printing, and is considered good if it can be peeled off without any resistance.
Marks and manuscripts that are stuck to the original but can be removed without causing various defects in the plate-making part are less workable but can be used, and Δ marks and peeling may cause defects in the plate-making part, or in severe cases. Those that caused tearing were marked as unusable and marked with an X.

(7) Number of sheets to be printed To check durability, the number of sheets to be printed was determined by the number of sheets until the heat-sensitive film was slightly torn in the printing machine and the same character and solid printability as the first sheet could no longer be obtained.

(8) A curlable heat-sensitive stencil printing base paper was made into a plate using the same plate-making machine as described above, and then evaluated as follows.

After making the plate, cut the base paper for thermal stencil printing into a size of 5xscm, place it on a flat table with the thermal film side up, and if it does not curl at all, it is considered good and marked as 0, and the size is 10m1.
Those that rose by 11 or more were marked as defective and marked with an X, and those in the middle were marked with a Δ.

(9) Planar orientation coefficient: The refractive index (Nz) of the film of the present invention in the thickness direction. A sample was taken out, and the refractive index (NZO) in the thickness direction was determined using the following formula.

Planar orientation coefficient = NZ/NZO The refractive index was measured using an Atsube refractometer.

[Example] The present invention will be explained based on examples.

Examples 1 to 5, Comparative Examples 1 to 2 Niletine terephthalate, isophthalate, and copolymer were used as raw materials. The proportion of isophthalate in Comparative Example 1 and Examples 1 to 5 is 30m0! %, 22.5g1
101%, 20mo1%, 17.5m.

1%, 15mo1%, and 2.5mo1% were copolymerized, and 0.51 parts by weight of carnauba wax was added to 100 parts by weight. Both IV=0
．． 6 is fed to an extruder, melt-extruded through a T-die at 280°C, wound around a rotating cooling roll (temperature 50°C) and cast, and fed into a stenter heated with hot air at 80°C. Stretched 3.0 times in the direction, then heat treated in a stenter at 150°C for 5 seconds,
A biaxially stretched film of 0 μm was obtained.

In Comparative Example 2, polyethylene terephthalate homopolymer was used as the raw material, and the temperature conditions were the same except that the temperature was 10° C. higher.

The content of carnauba wax in the obtained thermosensitive film was 0.5 parts by weight based on 100 parts by weight of the copolymer.

Examples 6 to 11, Comparative Examples 3 to 4 Ethylene terephthalate, isophthalate, copolymer 9 with an isophthalate ratio of 20 mo1% as raw materials
0 parts by weight was blended with 10% by weight of polyethylene terephthalate homopolymer, this was made into 100 parts by weight, and the content of carnauba wax was added as shown in Table 1. Other conditions were the same as in Example 1.

Example 12, Comparative Examples 5 to 6 As shown in Table 1, waxes with different numbers of carbon atoms as main components were used, and the amount added was 0.2
1 part by weight was added. Other conditions were the same as in Example 6, and the film thickness was adjusted to 3 μm.

As mentioned above, when the samples of Examples 1 to 12 and Comparative Examples 1 to 6 were laminated with Tetron gauze and plate making and printing tests were conducted,
The results shown in Table 1 were obtained.

From this result, it was found that a specific amount of a specific wax is contained, and
By using a biaxially stretched polyester film with a specific melting energy, it is possible to print letters with uniform thickness, clarity, and good sensitivity.Also, solid printing is clear and can be printed in various sizes. A thermosensitive film with good properties and sensitivity was obtained.

Examples 13 to 17, Comparative Examples 7 to 8 Ethylene terephthalate, isophthalate, and a copolymer with an isophthalate ratio of 20 mo1% were used as raw materials, and 1.01 parts by weight of sodium montanate was added as a wax for one mass. The heat treatment temperature was set to 18 in the order of Comparative Example 7, Example 13.14.15.16.17, and Comparative Example 8.
0'C1160℃, 150℃, 140℃, 130℃, 1
All conditions were the same except that the conditions were 00°C and 80°C.

When the above samples were formed into films, printed and evaluated in the same manner as in Example 2, the results shown in Table 2 were obtained.

The content of sodium montanate at this time was 1.
It was 0 parts by weight.

What is clear from these results is that when the heat shrinkage rate is within a specific range, a heat-sensitive film that satisfies text, solid printability, and other properties can be obtained.

[Effects of the Invention] The present invention provides the following excellent film for heat-sensitive stencil printing base paper by making a biaxially stretched film containing a specific amount of a specific wax in a specific polyester having a melting energy in a specific range. This is what I was able to obtain.

(1) Clear text and solid printing can be obtained.

(2) It is possible to obtain characters with uniform thickness and good size compatibility in solid printing.

(3) Sensitivity for text and solid printing is significantly improved.

(4) It becomes possible to express shading during solid printing, making it suitable not only for character printing but also for printing photographs, etc.

(5) After perforation, there is no fusion between the document and the thermosensitive film, and unlike conventional products, there is no need to coat with a release agent or the like, reducing costs and simplifying the work process.

Claims (1)

[Claims] 2, comprising 100 parts by weight of polyester containing 0.005 to 5 parts by weight of at least one type of wax whose main constituent is a compound consisting of a higher aliphatic monocarboxylic acid having 10 to 33 carbon atoms, or an ester thereof. A film for heat-sensitive stencil printing base paper, which is an axially stretched film, characterized in that the film has a crystalline melting energy of 3 to 11 cal/g.