JPS621575A - Heat-sensitive transfer film - Google Patents

Abstract

PURPOSE:To furnish a heat-sensitive transfer film making it possible to improve a sticking phenomenon at the time of heat-sensitive transfer and to make efficient the heat-sensitive transfer by a thermal printer, by a construction wherein a coat containing an acryl-silicone graft polymer is provided on the surface of the heat-sensitive transfer film whereon it contacts with a heating head. CONSTITUTION:A coating containing an acryl-silicon graft polymer is applied and dried on the surface of a heat transfer film whereon it contacts with a heating head, so as to provide a coat thereon. A polymer of acrylic ester or methacrylate ester can be mentioned as a component of an acrylic chain of the acryl-silicon graft polymer, and a substance having an alkyl polysiloxane structure, such as dimethyl polysiloxane, can be mentioned as a component of a silicon chain. Although the copolymerization ratio between the acrylic component and the silicon component is not defined in particular, the more ratio of the acrylic component is advisable in terms of the hardness of a coat and the adhesion thereof, and concretely, a coat in the ratio of about 6-9.5:4-0.5 is preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of application in M industry) The present invention relates to a film for thermal transfer, and more specifically,
This invention relates to a heat-sensitive transfer film provided with a coating film to prevent stick phenomenon.

(Prior Art and Problems) Various recording methods have been known in the past, but thermal transfer using a thermal recording device such as a thermal printer has the advantage of excellent operability and maintainability. In this method, the recording paper and the thermal ink layer of the thermal transfer film are brought into contact with each other, and the film is selectively heated by a pulse signal from a force a thermal head located on the opposite side of the ink layer. When you do so,
The ink layer is heated through the film, melts it, and transfers it to the recording paper.

However, if an attempt is made to shorten the input time to the heating head in order to speed up recording, it is necessary to increase the input power, which causes the following problems. That is, although it is desirable to adjust the heating to below the melting point of the base film and above the melting point of the thermal ink layer, increasing the input power makes it extremely difficult to adjust the fc, and the base film is fused to the heating head. This phenomenon occurs, and the feeding of the heat-sensitive transfer film is hindered. This phenomenon is called stick.

This results in a lack of clarity in recording, poor film running, etc.

(A Larger Means for Determining Problems) An object of the present invention is to provide a thermal transfer film that can completely improve the sticking phenomenon during thermal transfer and make thermal transfer by a thermal printer more efficient. The gist lies in a heat-sensitive transfer film characterized in that a coating film containing an acrylic-silicon graft polymer is applied and dried on the surface of the heat-sensitive transfer film in contact with a heating head to form a coating film.

Hereinafter, one aspect of the present invention will be explained in detail.

The acrylic chain component of the acrylic-silicon graft polymer used in the present invention includes a polymer of acrylic ester or methacrylic ester, and the ester groups of the ester include methyl, ethyl, n-propyl,
Saturation of isopropyl, n-butyl, inbutyl, l-methylguloyl, λ-ethyl phthyl, n-pentyl, n-hexyl, λ-ethylhexyl, n-hair, n-octyl, nonyl, tecyl, lauryl, stearyl, etc. Hydrocarbon group; λ-methyl-coptenyl, 3-methyl-2
Unsaturated hydrocarbon groups such as -butenyl and 3-methyl-3-pentenyl; human axyl groups such as hydroxyethyl and hydroxypropyl; halogenated alkyl groups such as chloromethyl, / -chloroethyl and +2-bromoethyl;
Examples include alkoxyalkyl groups such as methoxyethyl and ethoxyethyl; aminoalkyl groups such as 2-dimethylaminoethyl and 2-diethylaminoethyl; cycloalkyl groups such as cyclohexyl; phenyl group; benzyl group; tetrahydrobenzyl group; glycidyl group, etc. .

In addition, acrylamide, methacrylamide, N
Copolymers of α, d-ethylenically unsaturated monomers such as -methylalacrylamide, N-methylolmethacrylamide, styrene, and vinyltoluene are also mentioned as examples of the acrylic chain component.

On the other hand, examples of the silicon chain component include those having an alkylpolysiloxane structure such as dimethylpolysiloxane.

The copolymerization ratio of the acrylic component and silicone component is not particularly limited, but in terms of coating film hardness and coating film adhesion,
The more acrylic components there are, the better; specifically, 2 to 3, j:
≠～0. ! , especially r~ri! Neil 0. ! It is preferable that the degree of

An example of an acrylic-silicon graft polymer obtained by graft copolymerizing an acrylic component and a silicone component is ``Aron G S-J O'' manufactured by Toagosei Kagaku Kogyo ■.
Examples include thermoplastic types, or those in which the hydroxyl group added to the acrylic component is reacted with an isocyanate resin in the presence of a curing accelerator such as dibutyltin dilaurate, resulting in thermal crosslinking, and those in which a silane coupling agent is used. Can be used in a wide variety of ways, including cross-linked products.

Further, the heat-sensitive transfer film of the present invention may be provided with a coating film by applying and drying a coating material containing an alkoxysilane hydrolyzate together with an acrylic-silicon graft polymer.

Examples of the alkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-mercaptoglobiltrimethoxysilane. Examples include silane and dimethyldimethoxysilane, which can be expressed by a general formula. In the general formula above, R
1 and R2 are substituted or unsubstituted monovalent hydrocarbon groups, such as alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, aralkyl groups, or hydrogen atoms of these groups are partially substituted with other substituents (for example, mercapto groups). , Gridkin group, methacryloxy group, aba) group, etc.), and R3 represents an alkyl group.

Hydrolysis of alkoxysilane is carried out in the presence of an inorganic acid or an organic acid commonly used for hydrolysis, particularly preferably in a lower alcohol solvent such as ethanol, Impro/(Nol). Silica may be present in the coexistence, and in that case, colloidal silica may be added before, during, or after the hydrolysis, but it is preferably added before hydrolysis of the alkoxysilane. Colloidal silica The addition ratio is based on the amount of alkoxysilane used, and is based on the amount of alkoxysilane used.
Q-10 parts by weight (preferably 20-0 parts of ♂) of colloidal silica (as silica solid content) based on 20 parts by weight (preferably 0-λO parts). As colloidal silica, DuPont's Ludo
x), Monsanto Cyton (5yton),
Nalcoag manufactured by Nalcosha, Snowtex manufactured by Nichiryo Kagaku Co., Ltd., and the like are preferably used.

Al; The amount of xysilane hydrolyzate used is
~10. θO0 parts by weight.

The paint containing the alkoxysilane hydrolyzate is applied to the base film and then subjected to a curing treatment, preferably using various curing catalysts such as acetic acid.

It is cured by heating in the presence of sodium acetate, alkali metal salts of fatty acids, and chlorinated ammonium salts. The curing process depends on the thickness of the coating film, and the efficiency is usually 60 to ir.
at an ambient temperature of 0°C, for at least 70 seconds, preferably 70
It takes more than a second and less than a minute. In addition, number 10 for more than 1 minute
If you spend a few minutes on it, it will harden to a higher degree.

For this purpose, there is no need for a particularly long time. Note that there appears to be a chemical bonding relationship between the alkoxysilane hydrolyzate and colloidal silica.

The thickness of the coating obtained by applying and drying a coating containing this acrylic-silicon graft polymer (in some cases, also containing alcocosilane hydrolyzate) is determined by flexibility, surface coating processing efficiency, coating agent, etc. From the viewpoints of cost, thermal transfer efficiency of the thermal head, etc., it is preferable to make the thickness as thin as possible within the range where the stick prevention effect can be obtained.

The amount of coating film (solid content) after drying is λ ~ 0.0/f/ml
is preferable, and more preferably o, i~o, or? /m”
It is. If the amount of the coating film exceeds 1 ν, the flexibility of the coating film, the thermal transfer efficiency of the thermal head, and the efficiency of surface coating processing will decrease, which is undesirable. Also, 0.0/f/
If it is less than -, the stick prevention effect will not appear and it is not preferable.

The advantages of using the acrylic-silicone craft polyi-containing coating of the present invention compared to conventional mold release silicone resins are as follows.

■ Due to the contribution of the acrylic component, the adhesion of the coating film to the film is good.

■ Excellent abrasion resistance, with less generation and accumulation of paint film scum on thermal heads, etc.

■ Appropriate level of slipperiness, with little chance of print misalignment due to excessive slippage.

■ When applying hot-melt ink to the back side, there is less occurrence of coating repellency due to precipitation of uncured silicone components.

(2) Due to the contribution of the silicone component, the surface of the coating film has good releasability from the heating element, and has anti-stick ability comparable to that of silicone resin coatings.

In addition, when an alkoxysilane hydrolyzate is used in combination, the cured product of the alkoxysilane hydrolyzate has an appropriate hardness, so it has an anti-wear effect, and has very good heat resistance and has an anti-stick effect. It has good compatibility with acrylic-silicon graft polymers, so it has good coating processability, and has appropriate coating film hardness and surface slipperiness, so it has the potential to be applied to printers that are prone to print misalignment.

Incidentally, an antistatic agent may be added in order to reduce the chargeability of the coating film. Among these, polyether-modified silicone oil is preferred. It has excellent heat resistance, and like the normally used linear alkyl polysiloxane silicone oil, it suppresses the occurrence of repelling due to bloom components when applying hot-melt ink, and also has a suitable level of lubricity. Can be granted.

[L] Ninth, particles that do not dissolve in the paint solvent, such as benzoguanamine resin fine particles, may be added to impart good film running properties. The particles preferably have a spherical shape and have a suitable hardness and an average particle diameter of 1μ or less. For example, Nippon Shokubai Chemical Co., Ltd. "Xll'"Epostor" can be mentioned. The amount added is 0.1-2% based on the solid content of the coating film, as too much will cause a decrease in the adhesion of the coating film and sedimentation in the coating solution.
0XfjL% is preferred.

The base film used in the present invention is appropriately selected from films such as polyester such as polyethylene terephthalate, nylon, polycarbonate, polyglobylene, etc., but polyethylene terephthalate film is preferable because it has good heat resistance and has high strength even if it is thin. Z～Oμ
is preferred.

Furthermore, when a film having a thin metal film layer of aluminum, zinc, etc. provided on the surface of the film on which the coating film is formed is used, the antistatic effect is improved.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

In addition, in the following Examples and Comparative Examples, stick characteristics were evaluated according to the following two methods.

(1) Evaluation using a thermal printing device: A thermal printing device manufactured by Matsushita Electronic Components@ was used.

Thermal head specific resistance 27! Ω, applied voltage/3.7V
Printing was performed at 5 ec on a 1-bath A/width 8-2 area, and the stick characteristics of the surface (non-ink coated surface) of the thermal transfer film in contact with the heating head were evaluated.

(2) Evaluation using facsimile equipment: Fuji Xerox facsimile television; Biako Hiro! using a mold machine,
Print in the same manner as in (1) above and evaluate the stick characteristics.

1+: The running state of the thermal transfer film during printing was evaluated as follows.

Example 1 Main chain is methyl methacrylate resin.

Add boridimel siloxane chain to this, about 1% to the main chain.
Acrylic-silicone graft polymer liquid (manufactured by Toagosei Kagaku Kogyo ■0 Aron G5-
3o') was diluted with a mixed solution of methyl ethyl ketone (MEK)/) toluene, and this was coated on a 6μ thick polyethylene terephthalate film using a gravure coater to a temperature of about /00℃.
After drying, a film having a coating thickness of 0.2 mm was obtained. The non-coated side of the obtained film was hot-melt coated with a heat-melt ink consisting of paraffin wax and carbon black in a coating amount of about 3 V- on solids to obtain a film for thermal transfer.

The evaluation results of stick characteristics are shown in Table 1.

Example: A polydimethylsiloxane-based graft polymer containing a methyl methacrylate component with a water group as a functional group ("Aron Fronay)-1i!H'') was added at a solid content weight ratio≠O:3, and dibutyltin dilaurate was added in an amount of 0.0μ% by weight based on the resin solid content, and diluted with an MIK/toluene mixture. The paint was applied to a 6μ polyethylene terebutarate film as in Example 1 and heated to about ioC.
The inocyanate was crosslinked by heating for 3Q seconds, and after drying, a film having a coating density of 0.2 f/ze was obtained. A heat-melting ink was applied to the non-coated side in the same manner as in Example 1 to obtain a heat-sensitive transfer film.

The evaluation results of stick characteristics are shown in Table 1.

Example 3 A methyltrimexysilane hydrolyzate solution was added to the acrylic-silicon graft polymer solution used in Example 1 at a solid content ratio of 1/2 to 1/2, and methyl cellosolve/ME was added.
Using a running paint diluted with K mixed liquid, this was applied to a polyethylene terephthalate film having a thickness of tμ, and heated and cured at about 100° C. for 30 seconds to obtain a film having a coating density of 0.2 or more after drying. A heat-melting ink was further applied in the same manner as in Example 1 to obtain a heat-sensitive transfer film.

The evaluation results of stick characteristics are shown in Table 7.

Example 3: In the HA material used in Example 3, a large paint with a solid content weight ratio of methyltrimethoxysilane/colloidal silica of Conil was used instead of the methyltrimethoxysilane water decomposition product. An integrally cured coating film was obtained in the same manner as in Example 3, and a heat-melting ink was further applied in the same manner as in Example 1 to obtain a film for thermal transfer.

The evaluation results of stick characteristics are shown in Table 1.

Example! Example 3 Using the paint used in Example 3, polyether-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd. "KF-3!, 2#) was further added in an amount of 90% by weight based on the resin solid content. A heat-sensitive transfer film was obtained in the same manner as above.

The evaluation results of stick bamboo properties are shown in Table 7.

Example B In addition to the paint of Example 3, benzoguanamine resin fine particles (
“Eposter S” manufactured by Nippon Shokubai Chemical Co., Ltd.) to the resin solid content! A heat-sensitive transfer film was obtained in the same manner as in Example 3 using the paint containing M amount.

The evaluation results of stick characteristics are shown in Table 7.

Comparative example/Approximately ≠ heat melt ink on untreated 6μ thick polyester film. /Hot melt coating with coating t,
A sensitive pP4 transfer film was obtained.

The evaluation results of stick characteristics are shown in Table 7.

Table - (Effects of the Invention) The thermal transfer film of the present invention has an effect of preventing the stick phenomenon, and can efficiently perform thermal transfer using a thermal printer.

Sender: Diafoil Co., Ltd. Representative Patent Attorney Naga Kagawa - Others/names

Claims (3)

[Claims] (1) A film for thermal transfer, characterized in that a coating containing an acrylic-silicon graft polymer is applied and dried to form a coating film on the surface of the film that comes into contact with a heating head. (2) The heat-sensitive transfer film according to claim 1, wherein the coating film further contains a cured product of an alkoxysilane hydrolyzate. (3) The heat-sensitive transfer film according to claim 1 or 2, wherein the coating film contains colloidal silica.