JPH01226382A - Thermal transfer film ribbon - Google Patents

Abstract

PURPOSE:To obtain a highly detailed printing image, by constituting the stickiness preventing layer of a thermal transfer film ribbon of a specific silicon modified vinyl copolymer. CONSTITUTION:A thermal transfer ink layer is provided to the surface of a plastic film and a stickiness preventing layer is provided to the rear thereof. This stickiness preventing layer is composed of a silicon modified vinyl copolymer obtained by the radical polymerization of polysiloxane having an ethylenic unsaturated group and a radical copolymeric monomer and the heating temp. thereof at the time of a thermal weight change of 95 is 400 deg.C or more. A heating head is slid with this stickiness preventing layer and selectively heats the thermal transfer ink layer to form a printing image. At this time, a thermal transfer film ribbon is prevented from the generation of a hole large enough to obstruct the formation of a highly detailed printing image.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermal transfer film ribbon used in thermal transfer recording technology.

[Prior Art/Problems to be Solved by the Invention] The stick prevention layer of this type of thermal transfer film ribbon is already known as shown in Japanese Patent Publication No. 5G-13359. This configuration eliminates the poor running of the film ribbon due to the sticking phenomenon that occurs during high-speed image formation.

However, recently, in the formation of high-definition prints of 16 dots/aa+ or higher, a drawback has arisen in that a fine print cannot be obtained.

Regarding the cause of this defect, heat diffusion due to the thickness of the film as the base material, the thickness of the ink layer, and the thickness of the stick prevention layer became a problem, but it was not a decisive factor.

On the other hand, conventionally, in this type of thermal transfer film ribbon provided with a stick prevention layer on the back side, small holes have often been formed at the locations heated by the heating head.

The occurrence of the holes did not pose any problem in image formation in the case where high definition was not required in the past. However, when forming a high-definition print image as described above, it has been found that the larger the size of the hole, the lower the definition of the print image.

Based on this knowledge, it is an object of the present invention to make it possible to form high-definition print images satisfactorily without causing the above-mentioned hole formation phenomenon.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a thermal transfer ink layer on the surface of a plastic film, a stick prevention layer on the back side of the film, and a stick prevention layer. In a thermal transfer film ribbon that can selectively heat the thermal transfer ink layer by sliding a heating head on the ribbon, the anti-stick layer comprises a polysiloxane having an ethylenically unsaturated group and a radical copolymerizable monomer. The thermal transfer film ribbon is made of a silicone-modified vinyl copolymer radically copolymerized with a silicone-modified vinyl copolymer and has a heating temperature of 400° C. or higher when the thermal weight change of the anti-stick layer reaches 95%.

[Function] With the above configuration, large holes that would impede the formation of high-definition images are no longer generated.

Although the technical reasoning as to why such a problem could be solved by this structure has not yet been fully developed, in the conventional anti-stick layer, the anti-stick layer and film melted by heating with a heating head. While the base is attracted to surrounding non-heated areas by surface tension, it is speculated that in the present invention, such strong surface tension does not occur.

[Example] Next, the specific configuration will be explained.

In the present invention, the anti-stick layer is formed of a silicone-modified vinyl copolymer obtained by radical copolymerization of polysiloxane having an ethylenically unsaturated group (hereinafter referred to as vinyl-modified polysiloxane) and a radical copolymerizable monomer. ing.

As the vinyl-modified polysiloxane used in the present invention, any of those manufactured by various conventionally known methods can be used, but in particular, those having the following polysiloxane structure can be used. This is preferable from the viewpoint of ease of use.

-8l-P In the above formula, 2 is a (meth)acryloxypropyl or methyl group)]. Moreover, PSQ and S are the same or different, and each is an alkyl group having 1 to 3 carbon atoms, a phenyl group, or -0(SiR' R20) 81
(R')3 (Here, R1 and R2 are the same or different and each is an alkyl group having 1 to 3 carbon atoms or a phenyl group, R3 is an alkyl group having 1 to 3 carbon atoms, and n is O or is an integer of 1 or more) (excluding cases where P, Q and S are both an alkyl group having 1 to 3 carbon atoms and/or a phenyl group)
.

Among the (meth)acrylic modified polysiloxanes represented by the above formula, R1 and R2 are methyl groups (meth)
Acrylic-modified polydimethylsiloxane is preferred from the viewpoint of ease of production and economy.

Commercially available (meth)acrylic-modified polysiloxanes represented by the above formula include, for example, X-22-5004C manufactured by Shin-Etsu Chemical Co., Ltd., Silabrene PH-0711 and Silabrene PH-0721 manufactured by Chisso Chemical Industry Co., Ltd.
Examples include Silablane PM-0725.

In the present invention, P and Q represented by the above formula.

Using the vinyl-modified polysiloxane in which the sum of n of S is about 3 to 150, this is radically copolymerized with other radical copolymerizable monomers in a proportion of 5 to 80% by weight of the total monomers. , a resin with good film-forming properties, heat resistance, and abrasion resistance can be used.

If the sum of n of P and QSS exceeds 150, oily substances will come to the surface. On the other hand, the sum of n of P and QSS is 3
If it is less than that, the temperature at the completion of the thermogravimetric change will drop significantly. If the ratio is less than 5% by weight, the temperature upon completion of the thermogravimetric change will drop significantly, and if the unidirectional ratio exceeds 80% by weight, the friction resistance will drop significantly.

As the radical copolymerizable monomer to be radically copolymerized with the vinyl-modified polysiloxane, any conventionally known monomer can be used as long as it can be copolymerized with the vinyl-modified polysiloxane. . For example, methyl acrylate, ethyl acrylate, butyl acrylate,
Acrylic ester monomers such as β-hydroxypropyl acrylate and β-hydroxyethyl acrylate, methacrylic esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, and glycidyl methacrylate. system monomer,
Vinyl monomers such as styrene and vinyl acetate, maleimide monomers such as N-laurylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide, ethylene, propylene, etc. can be used alone or in combination as appropriate. It is possible.

Methods for radical copolymerization of the monomer and the vinyl-modified polysiloxane include conventionally known suspension polymerization methods,
Emulsion polymerization method, solution polymerization method, etc. can be used as appropriate, but in consideration of productivity, solution polymerization method is preferable. As the solvent and polymerization initiator used in the solution polymerization method, any conventionally used solvent and polymerization initiator can be used.

In addition, the thermogravimetric change of 95% as used in the present invention refers to a thermogravimetric analyzer 5SC15000 manufactured by Seiko Electronics Co., Ltd.
lO while supplying air at a rate of 200 ml/win.
The change in weight of the sample was measured by increasing the temperature at a rate of °C/ll1in, and the weight loss was 95% due to the rapid change in weight.
% is reached. The temperature at which the thermogravimetric change of the silicone-modified vinyl copolymer reaches 95% is preferably 400°C or higher.

If the temperature is less than 400°C, the heat resistance will be insufficient and large holes will tend to form.

The thermal transfer film ribbon of the present invention is prepared by dissolving the silicone-modified vinyl copolymer obtained as described above in a suitable solvent, coating it in a predetermined amount on one side of a plastic film, and drying it to form a stick prevention layer. At the same time, on the other side of the film, a heat-melt transfer ink layer made of a heat-melt vehicle or a heat-sublimation transfer ink layer in which a heat-sublimable dye is mixed and dispersed in a non-transferable binder is provided.

The thickness of the stick prevention layer is suitably in the range of 0.005 to 11 seconds; if it is less than this range, the stick prevention effect will be significantly reduced, and if it exceeds this range, the thermal conductivity will decrease due to the thickness. This causes a disadvantage that heat conduction in the thickness direction deteriorates, making it difficult to print high-definition images.

Next, the present invention will be explained with reference to Examples and Comparative Examples.

Examples 1 to 4 A silicone-modified vinyl obtained by radical copolymerization of a vinyl-modified polysiloxane and a radical copolymerizable monomer shown in Table 1 was placed on one side of a polyethylene terephthalate film having a thickness of 3.5 mm. Copolymer of methyl ethyl ketone
A xylene mixed solvent solution is applied and dried to form a stick prevention layer, and on the other side, the main component of the vehicle is wax and resin, the main component of the colorant is carbon black, the melting point is 69°C, and the thickness is 3AII11. A thermal transfer film ribbon was prepared by forming a heat-melting transfer ink layer.

Comparative Example A thermal transfer film ribbon was prepared in the same manner as in Examples 1 to 4, except that the stick prevention layer was formed of polymethyl methacrylate.

For each of the obtained thermal transfer film ribbons, the perforation of the N ribbon and the definition of the printed image were examined.

The evaluation of holes is based on the diameter of the holes that occur when printing using a thermal printer (PEN-24 manufactured by Canon) that has a thermal head composed of square heating dots with a side length of 0.17 mm. Judgment was made based on the average value.

In addition, the evaluation of definition was based on the average value of the width of fine lines obtained by printing with two adjacent dots (width 0.34 mg) of the thermal printer (numbers shown within 0 in Table 1 (unit III), below. Let this be L) is the width of the two dots (
Hereafter, the extent to which it expands relative to L (hereinafter referred to as L) is
The determination was made by expressing the expansion rate (%) as expressed by the following formula: 2 Pa A x 100 (in the formula, ΔL-L-L'').

These results are shown in Table 1. In Table 1, TGT means the temperature at 95% thermogravimetric change.

Note: Vinyl-modified polysiloxane mixture represented by the following formula (
The number average molecular weight is 5000).

In the previous formula, Zl is a wing.

C112-C-C-0-Cx)Is-, and p
, q and " are each integers, and Me is a methyl group (the same applies hereinafter).

The sum of the average values of plq and ``of the mixture is about 60.

A vinyl-modified polysiloxane mixture represented by the following formula (
The number average molecular weight is 1000).

Me Me In the above formula, zl is the same as above, and t is an integer. The average value of p for the mixture is approximately 1O.

[Effects of the invention] By composing the stay/stick prevention layer of the thermal transfer film ribbon with a specific silicone-modified vinyl copolymer, large holes that would impede high-definition image formation are not formed.
This made it possible to obtain high-definition prints.

Patent applicant: Fuji Kagaku Paper Industries Co., Ltd. Haka 1 person

Claims (1)

[Claims] 1. A thermal transfer ink layer is provided on the surface of a plastic film, a stick prevention layer is arranged on the back side of the film, and a heating head is brought into sliding contact with the stick prevention layer to selectively heat the thermal transfer ink layer. In the thermal transfer film ribbon, the stick prevention layer is made of a silicone-modified vinyl copolymer obtained by radical copolymerization of polysiloxane having an ethylenically unsaturated group and a radical copolymerizable monomer, and the stick prevention layer A thermal transfer film ribbon having a heating temperature of 400° C. or higher when the thermogravimetric change of the layer is 95%.