JPH01171985A - Recording material for thermal transfer - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer recording material being improved in the transfer adhesion of a thermal transfer ink layer, increasing a transferable property of informations and being improved in regard to a fault due to charging, by providing a polyester film with a coating layer made up of a polymer having a pyrrolidium ring in a main chain and of polyvinyl alcohol and a zirconium compound. CONSTITUTION:A recording material for thermal transfer has a coating layer made up of a polymer having a pyrrolidium ring in a main chain and of polyvinyl alcohol and a zirconium compound, at least on one surface of a polyester film. The polyester film may contain inorganic particles, organic particles, an organic lubricant, an antistatic agent, a stabilizer, dye, pigment and organic macromolecules as compositions as occasion demands. The rates of the polymer, the polyvinyl alcohol and the zirconium compound in the coating layer are preverably 30wt.%-92wt.%, 5-77wt.%, and 3-30wt.%, respectively, and further it is preferable that a crosslinking agent is contained in a coating agent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording material for melt-type thermal transfer having antistatic properties.

[Problems to be solved by conventional technology and invention]

The thermal transfer recording method uses a lightweight, small, and noise-free device, and has excellent operability and maintainability, and has begun to be widely used as a new information recording method in place of the conventional impact method. This thermal transfer recording method uses a thermal transfer material in which a thermal transfer ink layer consisting of a colorant dispersed in a heat-melting binder is laminated on a sheet-like support, and this thermal transfer ink layer is used for recording. The ink layer is stacked on the recording medium so as to be in contact with the medium, and heat is supplied from the support side of the thermal transfer material to the thermal head to transfer the melted ink layer onto the recording medium, thereby creating a heat-supplied shape on the recording medium. A corresponding transfer ink image is formed. Heat-melting binders include carnauba wax, Sasol wax, microcrystalline wax, castor wax, waxes such as α-olefin derivatives, stearic acid, valmitic acid, lauric acid, aluminum stearate, barium stearate, and stearic acid. Higher fatty acids such as zinc, zinc palmitate, methyl hydroxystearate, glycerol monohydroxystearate or their metal salts, derivatives such as esters, polyethylene, polypropylene, polyisobutylene, polyethylene wax, polyethylene oxide, engineered tyrene-acrylic acid copolymer Thermoplastic resins made of olefins alone or copolymers or derivatives thereof, such as ethylene/acrylic acid ester copolymers, ethylene-vinyl acetate copolymers, etc., and metal-crosslinkable ionomer resins are used. As the colorant, various dyes, pigments, carbon black, etc. used in printing and other recording fields are used.

However, the amount of paper used as a recording medium for thermal transfer recording methods, 9IC polyester film with good transparency, is used as projection material for overhead flow projectors, etc.
When used as a second original drawing for drafting purposes, the transfer of the heat-sensitive transfer ink layer of the heat-sensitive transfer material to the polyester film is not necessarily good. This is particularly noticeable when fine characters or lines are transferred using low thermal energy, and so-called dropouts occur, so there is a demand for polyester films that are good for thermal transfer recording.

There is a demand for a film that is easy to handle due to electrostatic charge, and that does not attract dust or other dirt or stains due to adhesion.

[Object of the invention] The object of the invention is to improve the transferability of a thermal transfer ink layer,
It is a thermal transfer recording material that improves the transferability of information and improves problems caused by charging.

[Means for solving problems]

In view of the above problems, the inventors of the present invention have made extensive studies and found that
The present inventors have discovered that a polyester film having a specific coating layer has excellent antistatic properties and good transferability of a heat-sensitive ink layer, and has completed the present invention.

That is, the gist of the present invention resides in a recording material for thermal transfer, characterized in that it has a coating layer made of a polymer having a pyrrolidium ring in its main chain, polyvinyl alcohol, and a zirconium compound on at least one side of a polyester film.

The present invention will be explained in detail below.

The polyester of the polyester film constituting the substrate in the present invention is polyethylene terephthalate in which the mole fraction of the constituent components is ethylene terephthalate or polyethylene naphthalate in which the mole fraction of the constituent components is ethylene naphthalate.

The polyester film of the present invention may contain inorganic particles, organic particles, organic lubricants, antistatic agents, stabilizers, dyes, pigments, and organic polymers as a composition, if necessary. In order to impart lubricity to a polyester film, fine particles are included in the film composition, but the type, size, and composition of the protrusion-forming agent are determined depending on the required properties such as lubricity and transparency of the product to be used. The amount is selected appropriately.

The polymer having a pyrrolidium ring in the main chain in the present invention is a polymer having a structure of the following formula (1) or (It) as a main component.

In the formula, Rq -Rt is usually an alkyl group, a phenyl group, or an acyl group, or the alkylenyl group may be substituted with a group shown below.

Substitutable groups include, for example, hydroxy, amido, carbo-lower alkoxy, lower alkoxy, phenoxy, naphthoxy, cyanide, thio-lower alkoxy, thiophenoxy, cycloalkyl (lower alkyl ammonium, lower alkyl), and the nitro group is an alkyl halogen. Groups can only be substituted on the phenyl group.

Moreover, R,, bird may be chemically bonded, for example, (CH2+m (m=an integer of λ to 5), CH(CH3) CH(CH3), CH=CH
CH=CH-1-CH=CH-CH=N-1-CH=C
H-N=CH-1+CH2+20mo CH2+2, +CH
Examples include 2hO(CH2)2-. Also,&,
Only one of the horses may be hydrogen.

X″″ in the formula is CI″-5Br-1l/coSO″ or //3PO″ (D inorganic acid group, CH3SO4-c2
H5SO4″, CI H21+, coo″″(1=/
Indicates an organic sulfonic acid residue or carboxylic acid residue (an integer between

The polymer of formula (1) in the present invention can be obtained by cyclopolymerizing the compound represented by using a radical polymerization catalyst. Further, the polymer of formula (n) is (ffI
) can be obtained by cyclization polymerization of a compound of formula ) in a system using sulfur diacid as a solvent. Polymerization is carried out using hydrogen peroxide, water, or a polar solvent such as methanol, ethanol, isopropanol, formamide, dimethylformamide, dioxane, acetonitrile, or sulfur dioxide as a solvent.
Although it can be carried out by a known method using a polymerization initiator such as benzoyl peroxide or tertiary butyl peroxide,
It is not limited to these.

The polymer having a pyrrolidium ring in the main chain in the present invention may contain a compound of formula (I) and a compound having a polymerizable carbon-carbon unsaturated bond as a copolymerization component.

The molecular weight of the polymer having a pyrrolidium ring in the main chain in the present invention is preferably SOO to 1,000,000, more preferably 1,000 to 300,000. If the molecular weight of this polymer is SOO, it has an antistatic effect, but
The strength of the coating film was weak, and it was sticky and easily blocked. If the molecular weight of this polymer is much higher than ioo,
The viscosity of the coating liquid increases, and handling and coating properties tend to deteriorate.

As the polymer having a pyrrolidium ring in the main chain in the present invention, commercially available products from Dai-Kogyo Seiyaku Co., Ltd., Nittobo Co., Ltd., and Merck & Co., Ltd. can be used for this purpose, but the polymer is not limited to these.

The polyvinyl alcohol in the present invention is a saponified product of polyvinyl acetate or a polyvinyl acetate copolymer, or a modified product of polyvinyl alcohol. The degree of saponification of polyvinyl acetate or polyvinyl acetate copolymer is preferably S O-/00 molar.

The proportion of copolymerized components in polyvinyl alcohol copolymer is 0
-SO molar ratio is preferred. This copolymer component is C
AFINCH edition'PolyvinylAlcohol
', JOHN WILEY & 5ONS,
/Published in 773, /Gutsu page ~ /AA page or Japanese Patent Application Publication No. 1973
Styrene, alkyl vinyl ether, vinyl versatate, (meth)acrylamide, ethylene, propylene, α-hexene, α, known as No. 9-/7944'g, etc.
Olefins such as octene, unsaturated acids such as (meth)acrylic acid, crotonic acid, maleic anhydride, fumaric acid, and itaconic acid, their alkyl esters and their alkali salts, and sulfonic acids such as co-acrylamide-co-methylpropane sulfonic acid. Containing monomers and their alkali salts, trimethyl-2(/-:, (meth)acrylamide-/
, I-dimethylethyl]ammonium chloride, cationic monomers such as l-vinyl-comethylimidazole and its 9th product, and silyl group-containing olefinic unsaturated monomers, but are not limited to these. do not have.

Modified products of polyvinyl alcohol include, but are not limited to, acetalized products, reaction products with reactive silane compounds, reactive unsaturated monomers, and the like.

The degree of polymerization of polyvinyl alcohols is preferably 10 to
5ooo, more preferably 30 to yooo.

The polyvinyl alcohols are preferably those that can be used in a water-soluble or water-dispersed state.・The zirconium compound in the present invention is Ink &
Pr1nt No. 1nt No. 1, No. 2A-Page 2g, /
Zirconium nitrate, zirconium oxychloride, etc. described in 9g7, published in 1998, exhibit cationic properties, but are not limited to these. These are thought to have a polymer structure due to a so-called bridging structure with hydroxyl groups as shown below.

In the present invention, the proportion of the polymer having a pyrrolidium ring in the main chain, polyvinyl alcohol, and zirconium compound in the coating layer is 30% by weight to 30% by weight of the polymer having a pyrrolidium ring in the main chain, polyvinyl alcohol is preferably 5 to 77% by weight, and 3 to 30% by weight of the zirconium compound. If the zirconium compound is less than 30% by weight, the effect of improving transparency may not be obvious depending on the proportion of polyvinyl alcohol, and if the amount is more than 30% by weight, the coating may not be effective. The film strength and stability of the coating solution may decrease.

In the present invention, it is preferred that the coating agent further contains a crosslinking agent. In other words, the crosslinking agent is not only effective in improving the strength of the coating layer, but also in improving the adhesion (blocking property), water resistance, and solvent resistance. It is preferable that the crosslinking agent does not coagulate with the cationic polymer having a ring, and is preferably water-soluble or water-dispersible.Examples of the crosslinking agent include, but are not limited to, the following.

+At Methylolation or alkylol compound melamine type, urea type, guanamine type, acrylamide type,
N-methylolated or N-alkylolated compounds such as polyamides can be used.

0 Epoxy compound An epoxy compound that has been made hydrophilic by introducing a hydroxyl group or a polyether group, or a hydrophobic epoxy compound that has been water-dispersed using a surfactant can be used. For example, low molecular or oligomer products are available from Nagase Kasei Co., Ltd., but are not limited thereto.

(0-block polyisocyanate In order for polyisocyanate to be able to be used in aqueous systems, the inocyanate group is once blocked and inactivated by reaction, and the so-called blocking agent is removed by heating, and the isocyanate group is regenerated. Examples include, but are not limited to, polyurethane compounds and products manufactured by Shikinichi Yakuhin Kogyo Co., Ltd. and Mitsubishi Chemical Industries, Ltd.

0 Aziridine Compound A compound having at least one aziridine group, which is a product of Nippon Shokubai Kagaku Kogyo Co., Ltd., but is not limited thereto.

(E Coupling agent As a so-called coupling agent, silicon-based, titanium-based, aluminum-based, zirconium-based, zirco-aluminum-based, etc. containing metal elements can be used, and various types of these are available as commercial products. be.

(F) Other compounds having groups that react with heat, peroxide, light, etc.
Examples include vinyl compounds, acrylic compounds, and photosensitive resins.

The proportion of the crosslinking agent in the coating layer in the present invention is preferably 3 parts by weight to SO weight parts, more preferably 5 parts by weight to 3θ weight parts.

The reason why the crosslinking agent has a weight width of 3 or more is because the improvement effect on coating film strength becomes less noticeable if the weight width is less than 3. In this case, the strength of the coating film may deteriorate, and the adhesion (blocking property) may deteriorate.

Note that in order to make the effect of the crosslinking agent more effective, it may be preferable to blend a polymer having a group reactive with the crosslinking agent.

The coating liquid in the present invention preferably has the above-mentioned composition dissolved or dispersed in water.

The medium of the coating solution is well-drained water, but alcohols, cellosolves, N- An organic solvent such as methylpyrrolidone may be added to the coating solution.

The coating liquid in the present invention contains silica, silica sol, alumina, etc. as inorganic fine particles to improve adhesion and lubricity.
Alumina sol, zirconium sol, kaolin, Merck,
May contain calcium carbonate, titanium oxide, barium salt, carpon plask, molybdenum sulfide, antimony oxide sol, etc., and if necessary, antifoaming agent, coating improver, thickener, organic lubricant. , organic polymer particles, antioxidants, ultraviolet absorbers, blowing agents, dyes, pigments, and the like.

Furthermore, the coating solution of the present invention may contain a polymer other than the polymer of the present invention in order to improve the properties of the coating solution or the coating layer.

A coating solution is applied to an unstretched polyester film using a reverse roll coater, Clavier coater, rod coater, air doctor coater, or other coating equipment as shown in "Coating Method" published in 2010, and uniaxially stretched either sequentially or simultaneously. Method, / Method of applying to an axially stretched polyester film and further stretching in a direction perpendicular to the previous l-axis stretching direction, or method of applying to an l-axis stretched polyester film and further stretching in the transverse and/or longitudinal direction There is also a method of coating an axially stretched polyester film product.

The above-mentioned stretching step is preferably carried out at AO, /30°C, and the stretching ratio is at least Hiro times or more in terms of area ratio, preferably 6 to 20 times.

The stretched film is heat treated at 1so-2so°C.

Furthermore, in the maximum temperature zone of the heat treatment and/or the cooling zone of the heat treatment outlet, the temperature is 0.2 to -0 in the longitudinal and transverse directions.
% relaxation is preferred.

In particular, the coating solution is applied to an l-axis stretched polyester film that has been stretched 2 to 6 times by the roll stretching method at 1.0-130°C, and then dried appropriately, or the polyester l-axis stretched film is prepared without drying. Immediately stretched 2 to 6 times at go-i, yo °C in a direction perpendicular to the previous stretching direction,
A method in which heat treatment is performed at 150 to 230°C for 1 to 1.00 seconds is preferred.

According to this method, it is possible to dry the coating layer at the same time as stretching, and the thickness of the coating layer can be reduced according to the stretching ratio, and a film suitable as a polyester film base material can be produced at a relatively low cost. can.

The coating liquid in the present invention may be applied to only one side of the polyester film, or may be applied to both sides. When the polyester film of the present invention is coated only on one side, a coating layer other than the coating liquid of the present invention can be formed on the opposite side as necessary to impart other properties to the polyester film of the present invention.

In order to improve the applicability and adhesion of the coating agent to the film, the film may be subjected to chemical treatment or discharge treatment before coating. Further, in order to improve the adhesion, coating properties, etc. of the l-axis stretched polyester film of the present invention to the coating layer, the coating layer may be subjected to a discharge treatment after the coating layer is formed.

The polyester film coated with the coating solution of the present invention obtained as described above preferably has a thickness of 30 to isoμ, and the thickness of the coating layer ranges from o, oiμ to 5μ. is preferable, and more preferably in the range of 0.02μ to lμ. If the thickness of the coating layer is less than 0.0/μ, it is difficult to obtain a uniform coating layer and uneven coating is likely to occur on the product. If it is thicker than sμ, the lubricity decreases and the film becomes difficult to handle. I don't like it.

〔Example〕

Hereinafter, the present invention will be explained based on examples, but the present invention is not limited by the following embodiments as long as the gist thereof is not exceeded. In addition, evaluation in Examples is based on the following method.

(1) Antistatic property A Charge decay property Using a static honest meter (trade name) manufactured by Shishido Shokai, a voltage of 10 kV was applied to the discharge electrode at a height of α above the sample at 23°C and in an SOCH RH atmosphere. The film was charged with electricity, and the discharge was stopped after the amount of charge was saturated.Thereafter, the charge decay property of the sample was measured with an electrometer placed 2cIIL above the sample, and the half-life was determined.

S seconds or less: (Extremely good) 5-30 seconds = (Good), 30-1.00 seconds: (Slightly good 9 100 seconds or more: (Poor) i6oo is a concentric electrode with a soH diameter and an outer electrode diameter of 7014N.
gA (trade name) was placed on the sample in an atmosphere of 23°C and SO%RH, and a voltage of 100V was applied. ? The surface resistivity of the sample was measured using u9A (trade name).

C Asche test, 3°C, 60 R1 (in an atmosphere, hold gauze on your fingertips and rub the sample surface 10 times to charge the film, and use Thyroid 1so, which is a fine silica particle from Fuji Deguin Co., Ltd.)
(Product name), measured the distance at which the fine particles were adsorbed to the film, and judged according to the following criteria. This test also serves as an evaluation of the strength of the coating film, since if the coating film is damaged by the friction of the gauze, the antistatic effect will be lost.

(2) Thermal transfer property A The monochrome image thermal transfer device is a newly manufactured πP core aoB-ON manufactured by Gotemba.
was used. As the thermal transfer material, one having a black ink layer manufactured by Fuji Kagaku Paper was used. The thermal transfer conditions were as follows: the current application time was 20 milliseconds, the current application energy was 1 dot per millimeter, and the transfer ink line width was 0.1 mm. As a criterion for determining the transferability of a thermal transfer ink, a case where qo% or more of the linearly thermally transferred ink layer was transferred to the polyester film was considered to be a pass, and a case below that was judged to be a fail.

B. A color scanner printer CX-SOOO (trade name) manufactured by Sharp Corporation was used as a color image thermal transfer device. The heat-sensitive transfer material used was made by Utsukurihosen Shinshin Co., Ltd. and consists of nine colors: yellow, cyan, magenta, and black. The device conditions were such that the print density was lightened using the print density adjustment knob on the device so that the difference could be easily seen.

To judge the image gradation, etc., we used the Color Chart of the Institute of Image Electronics Engineers of Japan.

(3) Coefficient of Friction ASTM D-/g9 This is carried out in accordance with the method modified so that it can be measured using a tape-shaped sample. A film without a coating layer and a film with a coating layer are placed one on top of the other with the coating layer facing inside, and cut into a tape having a width of /jll+1 m. Load 1ooy, tensile speed J Ozl/m1
Measure at It. The measurement is performed in an atmosphere at a temperature of 23° C. and a humidity of so%.

(4) Transparency In accordance with JIS K1.7/II, shear haze was measured using an integral turbidity meter NDH-20D (trade name) K manufactured by Nippon Heavy Industries, Ltd.

Comparative Example 1 Polyethylene terephthalate having an intrinsic viscosity of O, ta was melt-extruded at a temperature of 2 gO<0>C to 300<0>C, and an amorphous film having a thickness of g20μ was obtained by casting on a cooling drum using an electrostatic adhesion method.

This film was stretched 3.3 times in the machine direction at 95° C., further stretched 3.3 times in the transverse direction at 110° C., and heat-treated at 21 parts° C. to obtain a λ-axis stretched film with a thickness of 75 μm.

The haze of the obtained film is &, /, the coefficient of static friction is 0
．． 'lJ, dynamic friction coefficient was 0.4'/, and surface resistivity was 10'5Ω/mouth or more. In addition, the charge decay properties of the film and the assembly test results were poor. Furthermore, the heat-sensitive transfer properties of the film were poor, with missing prints occurring.

In other words, this film was unsuitable as a thermal transfer recording material. After longitudinal stretching of Examples/Comparative Examples/
3P (trade name) 95 parts (solid weight, the same applies hereinafter), Gohsenol GLOj (trade name) 4 parts 5 parts, which is a polyvinyl alcohol manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd., and a zirconium compound manufactured by Kigenso Kagaku Kogyo Co., Ltd. A certain zircozole ZC-
2 (trade name): Apply an aqueous dispersion of 10 parts to both sides,
Thereafter, the film was laterally stretched and heat treated in the same manner as in Comparative Example/, so that the thickness of the coating layer was O, OSμ, and the thickness of the base film was 75.
4&μ coaxially stretched polyester film.

The haze of the obtained film was 4. j, the coefficient of static friction is o
, lIq, dynamic friction coefficient is O, eA, surface resistivity is S
X/08Ω/mouth. Further, the heat-sensitive transfer properties of the film were good, and the charge decay properties of the film were also good.

In place of the aqueous dispersion in Example/Example, Jarol DC-, a polymer having a pyrrolidium ring in the main chain manufactured by Dai-Kogyo Seiyaku Co., Ltd., was used.
30,? P (trade name) 70 parts, polyvinyl alcohol theargosenol GLθ5 manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.
-Product name)'10 parts, Zircosol ZC-2 (trade name) 1, a zirconium compound manufactured by Kigenso Kagaku Kogyo Co., Ltd.
Coating thickness O, OS
A coaxially stretched polyester film with a thickness of 75 μm as a base film was obtained.

The haze of the obtained film is gu, 2, and the coefficient of static friction is 0.
．． 'l/, the coefficient of dynamic friction was o, ti, 7, and the surface resistivity was gX/08Ω/mouth. The charge decay properties and assembly test results of the film were good, and the heat-sensitive transfer properties of the film were also good.

In other words, this film could be put to practical use as a thermal transfer recording material.

Example 3 Polyethylene terephthalate having an intrinsic viscosity of 0.65 was melt-extruded at a temperature of 20° C. to 300° C., and an amorphous film having a thickness of SSO μ was obtained by casting on a cooling drum using an electrostatic adhesion method.

This film was stretched 3.3 times in the longitudinal direction at 95°C,
Both sides of this film are coated with Jarol DC-?
03P (trade name) 4 parts 0 parts, Gohsenol GLOs (trade name), a polyvinyl alcohol manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd., 35 parts, Zircosol ZC-2 (trade name), a zirconium compound manufactured by Kigenso Kagaku Kogyo Co., Ltd. ) 10 copies,
5 parts of alkylol melamine, 1 part of Bunacol EX-ssl (trade name), a water-based epoxy compound manufactured by Nagase Kasei Co., Ltd.
After applying an aqueous dispersion consisting of 0 parts, the film was stretched at 110° C. in the transverse direction tlc, 3.3 times to 1.210
A coaxially stretched polyester film having a coating layer thickness of 0.0 Aμ and a base film thickness SO゛μ was obtained by heat treatment at ℃.

The haze of the obtained film was 3. O5 static friction coefficient is o
, q, the coefficient of dynamic friction is 0. '19, surface resistivity is F
X/0”Ω/mouth.Charge decay property of the film,
The results of the ash test were good, and the heat-sensitive transferability of the film was also good. Film runnability, thermal transfer performance, cutting workability, and alignment of stacked films of A+ plate printed products using a thermal transfer device that unwinds this film from a roll, performs thermal transfer, and then cuts it into A1 size sheets. The properties (e.g., removability and extraction) were good.

In other words, this film could be put to practical use as a recording material for thermal transfer.

〔Effect of the invention〕

The recording material for thermal transfer of the present invention is not only good in transferability of thermal transfer ink, but also excellent in antistatic effect and excellent in handling workability of the recording material.

Sender: Diafoil Co., Ltd. Proxy manager - Others/names

Claims (1)

[Claims] (1) A recording material for thermal transfer, characterized in that it has a coating layer on at least one side of a polyester film comprising a polymer having a pyrrolidium ring in its main chain, polyvinyl alcohol, and a zirconium compound.