JPS63191680A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To stabilize feeding at the time of printing, reduce noise, suppress exfoliation of a coated film and contamination of a thermal head and ensure clear printing, by providing an anti-sticking layer comprising a crosslinked polyester copolymer and an organopolysiloxane in a specified ratio and having a specified thickness on a side of a base film opposite to the side of an ink layer. CONSTITUTION:A heat-fusible or sublimable transfer ink later is provided on one side of a plastic film, and an anti-sticking layer comprising a mixture of (A) a crosslinked polyester copolymer and (B) an organosiloxane and having a (B)/(A) weight ratio of 0.01-8 and a thickness of 0.03-3mum is provided on the other side. The crosslinked copolymer is a polyester copolymer crosslinked by heating or irradiation with UV rays after adding a known crosslinking agent for a polyester, or a copolymer obtained by introducing a reactive group into the polyester copolymer, followed by self-crosslinking. The organopolysiloxane may be a silicone oil or a modified silicone oil.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermal transfer material, and more particularly to a thermal transfer material that prevents sticking during printing and runs smoothly.

[Background Art] In recent years, recording media suitable for various hard copy devices have been put into practical use as we move toward a highly information-oriented society.

In particular, thermal printers, which use heat to melt heat-melting ink that is solid at room temperature and transfer it to transfer paper, have strict requirements such as small size, light consumption, low noise, and high-speed printing. Conventional thermal transfer materials based on plastic film have drawbacks such as a phenomenon (sticking) that occurs due to their lack of heat resistance, which causes fusion with the thermal head and significantly impedes running performance, and this tendency increases with high-speed printing. This problem has become more noticeable due to the increase in applied voltage and multicolor printing. To prevent this sticking, methods include adding inorganic particles such as siloids and calcium carbonate to roughen the surface to reduce contact with the thermal head, and mixing lubricants such as wax as an anti-sticking layer on the opposite side of the ink surface. A method of providing a thermoplastic resin layer or a fluororesin layer has been proposed.

[Problems to be Solved by the Invention] A thermal transfer material using a plastic film as a base material is fused to a thermal head, which significantly impedes running or, in extreme cases, makes it impossible to run. Furthermore, when using a plastic film whose surface has been roughened with inorganic particles, etc., if the surface is roughened to the extent that it prevents sticking, the ink layer will not be sufficiently transferred to the paper, resulting in unclear and rough prints. When the degree of surface roughening is reduced, there are drawbacks such as significant noise during running.

Although a layer containing a lubricant such as wax or a fluorine-based resin is effective in preventing sticking, the coating film has poor toughness and adhesion to the base plastic film is insufficient, making it difficult to use while driving. The paint film may fall off and contaminate the thermal head, or the noise level during running may be insufficient.

The object of the present invention is to provide a thermal transfer material that does not have the above-mentioned drawbacks, that is, has no sticking, excellent adhesion to the plastic film as a base material, low noise during printing, and clear printing performance. It is in.

[Means for Solving the Problems] The object of the present invention is to provide a transfer ink layer on one side of a plastic film that melts or sublimates when heated;
The other side has (A) a crosslinked polyester copolymer and (
B) consisting of a mixture of organopolysiloxanes, and (
B/A> weight ratio is 0.01 to 8, thickness is 0.03 to 3
This is achieved by a thermal transfer material characterized by being provided with an anti-sticking layer of .mu.m.

As the base plastic film for the thermal transfer material of the present invention, any known plastic film may be used as appropriate. Typical examples include polyester film, polycarbonate film, triacetyl cellulose film, cellophane film, polyamide film, polyimide film, polyphenylene sulfide film, polyetherimide film, polyether sulfone film, and polyolefin film.

However, it is preferable to use polyester film, polycarbonate film, and polyphenylene sulfide film in terms of price and heat resistance. Polyester film is more preferable in terms of toughness, flatness, and dimensional stability. (hereinafter abbreviated as PET) A biaxially stretched film (hereinafter referred to as PET) consisting of a copolymer containing 90 mol% or more of PET components (
Hereinafter, the biaxially stretched film will be abbreviated as BO film. ) are particularly suitable.

The thickness of the plastic film is not particularly limited, but is usually 0.5 μm or more and 40 μm or less, preferably 1 μm.
The thickness is not less than 10 μm. The base film has a tensile modulus of elasticity of 100 to 20 at 25°C and 65% rh measured with a Tensilon type tensile tester at a tensile rate of 200 nwn/min.
00 k'i/mn+ 2. The heat shrinkage rate measured at 120°C is preferably 2% or less. The plastic film may be roughened on one or both sides using particles or the like in order to provide slipperiness, but in this case, if the surface is extremely roughened, the transfer of the ink layer to the paper may become difficult. JIS-BO6 may be insufficient and the printing will be unclear.
Center average roughness Ra measured according to 01-1976
is 01OO5~0.4μm, maximum surface roughness (Rt) is 0
．． It is preferable to use a material having a diameter of 0.05 to 4 μm or less.

The base plastic film may contain dispersed additives such as a weathering agent, a coloring agent, a matting agent, an antistatic agent, and a flame retardant, as long as the object of the present invention is not impaired. The surface of the rough film may be subjected to discharge treatment, primer treatment, antistatic treatment, matting treatment, flame retardant treatment, coloring, etc.

The melting or sublimating transfer ink constituting the transfer ink layer provided on one surface of the base plastic film is also not particularly limited, and any known one can be used as appropriate. The main components of the hot-melt ink are (1) a wax with an appropriate melting point such as paraffin wax, microcrystalline wax, or carnauba wax, (2) a pigment, and (3) a softener such as oil. Typical examples include those with various additives added depending on the situation.Pigments used in this case include azo pigments, phthalocyanine pigments, and for dyeing, lakes, condensed polycyclic pigments, nitrone pigments, alizarin lakes, etc. Organic pigments are a representative example.On the other hand, sublimation inks include (1) water-soluble acrylics such as hydroxyethyl cellulose, polyvinyl alcohol, or polyamide resins, and (2) yellow, magenta, and cyan inks. Typical examples include those that are mainly composed of sublimable dyes, with various additives added as necessary.Sublimable dyes include:
Representative examples include disperse dyes, basic dyes and oil-soluble dyes. Although the thickness is not particularly limited, it is usually 0.1 to 15 μm, preferably 1 to 6 μm.

The thermal transfer material of the present invention is characterized in that a layer consisting of a mixture of (A>crosslinked polyester copolymer and (B) organopolysiloxane) is provided on the opposite side of the base plastic film from the ink layer. A polyester copolymer crosslinked with a polyester copolymer is a polyester copolymer that is crosslinked by heating, ultraviolet rays, electron beams, etc. by adding a known crosslinking agent that crosslinks the polyester by reacting with the carboxyl group and hydroxyl group at the end of the polyester. A reactive group is introduced into a polyester copolymer and self-crosslinked either alone or by heating using a crosslinking catalyst.

The former polyester copolymer is a normal polyester copolymer having a carboxyl group or a hydroxyl group at the terminal, and is obtained by polycondensing a dicarboxylic acid component and a glycol component, and is not particularly limited.

The dicarboxylic acid component includes aromatic, aliphatic, and alicyclic dicarboxylic acids, such as terephthalic acid, isophthalic acid,
Orthophthalic acid, 2,6-naphthalene dicarboxylic acid, adipic acid, sebacic acid, succinic acid, glutaric acid, 1,3
Examples include -cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, dodecanedicarboxylic acid, and abilainic acid. In addition, a dicarboxylic acid containing a sulfonic acid metal group can be used as a copolymerization component in order to make the polyester copolymer water-soluble or to impart water-based dispersibility. Examples include metal salts of sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene 2,7-dicarboxylic acid, and 5[4-sulfophenoxy]isophthalic acid.

The glycol component to be reacted with the dicarboxylic acid mentioned above is an aliphatic glycol having 2 to 8 carbon atoms, or an aliphatic glycol having 6 to 8 carbon atoms.
12 alicyclic glycols, specific examples include ethylene glycol, 1,2-propylene glycol, 1,3
-Propanediol, 1,4-butanediol, neopendel glycol, 1,6-hexanediol, 1,2
Cyclohexane dimetatool, 1,3-cyclohexane dimetatool, 1,4-cyclohexane dimetatool,
These include p-xylylene glycol, diethylene glycol, triethylene glycol, and the like. Polyethylene glycol, polypropylene glycol, or polytetramethylene glycol may be used as part of these glycol components.

The polyester copolymer obtained from the dicarboxylic acid and glycol components is used after being dissolved or dispersed in water, an organic solvent, a mixed solvent of water and an organic solvent, or the like.

These copolymerized polyesters preferably have many terminal groups from the viewpoint of crosslinking properties, and have a hydroxyl value of 3 to 200 mCJKOH.
/Q polymer, preferably 5 to 100 mg KOH/g polymer. When the hydroxyl value is 3 or less, reactivity is poor, and when it exceeds 200, the toughness of the coating film is poor. Further, when the glass transition point of the copolyester is 10 to 90°C, preferably 40 to 70°C, suitable stick resistance is exhibited.

The crosslinking agent for crosslinking the polyester copolymer is not particularly limited as long as it reacts with the terminal carboxyl group or hydroxyl group to make it three-dimensional, but typical examples include methylolated or alkylolated urea type, and melamine type. , acrylamide-based resins, polyamide-based resins, epoxy compounds, isocyanate compounds, and aziridine compounds. Among these, methylolated melamine and isocyanate compounds are preferably used in terms of adhesion to the substrate and stick prevention properties. The amount of crosslinking agent to be added is appropriately selected depending on the type of crosslinking agent, but it is preferably added in an amount equivalent to the terminal amount of the polyester copolymer, and usually 2 to 30 parts in terms of solid content relative to the polyester copolymer. ,
Preferably it is 5 to 20 parts.

In addition, what is a polyester copolymer that has introduced reactive groups?The following compounds that have functional groups such as reactive functional groups, self-crosslinking functional groups, and hydrophilic groups are introduced into the polyester copolymer that is the backbone polymer. This is what I did. Examples of compounds having a carboxyl group or a salt thereof, or an acid anhydride group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of compounds having an amide group or an alkylolated amide group include acrylamide, methacrylamide, N-methylmethacrylamide, methylolated acrylamide, methylolated methacrylamide, ureido vinyl ether, β-ureido isobutyl vinyl ether, ureido ethyl acrylate, etc. can be given. Compounds containing water [i include β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, β-hydroxyvinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, polyethylene glycol monoacrylate, polyethylene Examples include glycol monomethacrylate, polypropylene glycol monoacrylate, and polypropylene glycol monomethacrylate.

Examples of compounds having an epoxy group include glycidyl acrylate and glycidyl methacrylate.

Among these reactive groups, grafted products of acrylic acid and methylolated acrylamide are preferred in terms of adhesion to the substrate, stick resistance, and the like.

After coating, the polyester copolymer having these reactive groups can be crosslinked by heating, etc., but it is more preferable to use a crosslinking catalyst in combination because the crosslinking will proceed further. As a crosslinking catalyst, ammonium chloride, ammonium nitrate, citric acid, oxalic acid, p-toluenesulfonic acid, dialkyltin &
The amount of crosslinking catalyst to be added is 0.5 to 5 parts of the polyester copolymer in terms of solid content,
Preferably it is 1 to 3 parts.

After applying the polyester copolymer containing a crosslinking agent and the polyester copolymer containing a reactive group to the substrate, heating and
Crosslinking is carried out using ultraviolet rays, electron beams, etc., but the most common method is heating.

Heating is not particularly limited as long as it can be crosslinked to the extent that the purpose of the present invention can be achieved, but it is usually heated at 60 to 150 °C for 5
The heating time is from seconds to 5 minutes, preferably from 10 seconds to 2 minutes at 80-130°C. However, when the base film is a biaxially stretched polyester film, it is more preferable because drying and heat treatment can be performed after coating during the manufacturing process, and crosslinking can be carried out at a higher temperature for a shorter time.

The organopolysiloxane (B) used as a mixed component with the above-mentioned crosslinked polyester copolymer has the purpose of imparting compatibility, hydrophilicity, reactivity, adsorption, lubricity, etc. with the silicone oil and the resin to be blended. Examples include modified silicone oils into which various functional groups have been introduced.

Representative examples of organopolysiloxanes applicable to the present invention are represented by the following general formulas (a) to (c).

II ......(c) [where X, Y, and Z are integers of 1 to 5000, R is an alkyl group or hydroxyl group having 1 to 100 carbon atoms, R' is an alkylene group having 1 to 10 carbon atoms, phenylene Rh is hydrogen, an alkyl group having 1 to 100 carbon atoms, an epoxy group, an amino group,
carboxyl group, phenyl group, hydroxyl group, mercapto group,
R represents a group selected from a polyoxylene alkyl group and a halogen-containing alkyl group, and R represents a group selected from an alkyl group having 1 to 100 carbon atoms, a polyoxylene alkyl group, a hydroxyl group, and a halogen-containing alkyl group. ] Specific examples include dimethylpolysiloxane oil, amine-modified silicone oil, epoxy-modified silicone oil, epoxy/polyether-modified silicone oil, carboxyl-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, alkyl- and alkyl-aralkyl-modified silicone oil. Examples include silicone oil, alkyl/aralkyl/polyether-modified silicone oil, fluorine-modified silicone oil, alkyl/higher alcohol ester-modified silicone oil, methylhydrogene, polysiloxane oil, phenylmethyl silicone, and emulsified products thereof. can.

Dimethylpolysiloxane oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, polyether-modified silicone oil, amine-modified silicone oil and emulsions thereof are preferred in terms of anti-sticking properties and noise-preventing properties. Further, two or more of these may be mixed and used in any ratio. Furthermore, a known crosslinking agent that reacts with the reactive group of the silicone oil may be used in combination.

For example, it is more preferable to use a compound such as an amine, amide, or melamine in combination with a silicone oil having an epoxy group, since this will reduce the amount of oil desorption.

The organopolysiloxane suitable for the present invention has a viscosity of 100 centistokes (hereinafter referred to as C-8) or more and 5 million C-8 or less, preferably 2000 C·S or more and 3 million C-8 or more, as measured at 25°C. -8 or less is preferable.

(A>Polyester copolymer having crosslinking property and (B) organopolysiloxane can be mixed in any ratio using a common organic solvent or water, but the effect of the present invention is (B/A
) is 0.01-8, preferably 0.1-5, more preferably 0.2-1. ('B/
When A) is less than 0.01, the anti-sticking effect is not sufficient and the noise during printing is also large. If it exceeds 8, it is not preferable because the adhesion to the base plastic film may be poor or the coating film may become sticky and have poor runnability. Excellent effects are exhibited only when (B/A) is within the range of the present invention.

The thickness of the anti-sticking layer of the present invention is 0.03 μm or more and 3 μm or less, preferably 0.1 μm or more and 1 μm or less. If it is less than 0.03 μm, it is insufficient in terms of preventing sticking and noise, and even if it is applied more than 3 μm, the sticking improvement effect will not increase and the toughness of the coating film and the clarity of the print will decrease. It is not desirable because Further, anti-blocking agents, lubricants, pigments, coloring agents such as dyes, plasticizers, light and heat stabilizers, surfactants, etc. may be added to this coating layer within a range that does not impair the effects of the present invention.

Next, a typical method for manufacturing a thermal transfer material of the present invention will be described, but the present invention is not limited thereto. First, prepare a plastic film as a base material. This film may be subjected to corona discharge treatment in air or other various atmospheres, if necessary. Anchor treatment may also be performed using a known anchor treatment agent such as urethane resin or epoxy resin, but this is usually not necessary. After coating the film with an anti-sticking layer using a known method such as gravure coating, reverse coating, or spray coating, it was heated at 60'C to 250°C for 1 s.
Dry for about 15 minutes. Next, heat-melting or sublimation ink is coated on the opposite side in the same manner, and then
Dry at specified temperature.

These coats may be performed in any order, and of course may be performed simultaneously. In addition, a coating layer is separately formed,
You can laminate it later, but the coating layer is
Since the strength is somewhat insufficient, a method of directly coating the base film is preferred. The transfer ink layer can be coated by a known method such as barcode coating, reverse coating, gravure coating, etc., regardless of whether before or after the anti-sticking layer is coated.

Moreover, when the base film is biaxially stretched, it is also possible to apply it during the manufacturing process. Specifically, an example is as follows: 1. An anti-sticking layer is applied to at least one side of a polyester film after being stretched in one direction.
After drying or after stretching in the right angle direction while drying,
The method includes performing heat treatment, or stretching in the perpendicular direction, then re-stretching in the one direction, and then heat treatment.

Although the effects of the present invention can be fully exerted by either the former method or the latter method, the latter method is preferred from the viewpoint of the toughness of the anti-sticking layer and economical efficiency.

[Effects of the Invention] The present invention provides the following advantages by providing a crosslinked polyester copolymer and organopolysiloxane in a specific ratio and a specific thickness as an anti-sticking layer on the opposite side of the base film from the ink layer. I was able to get the desired effect.

(1) Stable running with no sticking during printing.

(2) The noise during printing is extremely low.

(3) Due to the high adhesion with the base film, there is little chance of paint film falling off or contamination of the thermal head.

(4) Printing is clear.

Since the thermal transfer material of the present invention has the above-mentioned excellent effects, it is particularly suitable for use in facsimile machines, bar code printers, graphic printers, automatic ticket issuing machines, and the like.

[Method for evaluating characteristics and effects] Sticking properties, noise during running, and print clarity were evaluated using a serial printer and a line printer shown below.

(a) Serial printer: Sharp Shoin WD300
Print voltage 10V, 12V using F type word processor
I ran it and printed it.

(b) Line type printer 2 Using Mitsubishi line thermal color printer G500F-10 type, applied voltage 17V
I ran it and printed it.

The evaluations of (a) and (b) above were determined based on the following criteria.

(1) Anti-sticking properties ◎: Running is stable with no sticking at all.

O: Hardly any sticking.

Δ: Slight sticking occurs.

×: Sticking is significant and driving becomes impossible.

(2) Noise when driving ◎: Significantly small.

○: There is some noise, but it is hardly noticeable.

Δ: There is a very annoying noise.

X: The noise is extremely loud.

(3) Clarity of printing ◎: No scratching, fading, or deformation at all.

○: Easy to handle, no fading or deformation.

△: Slightly deformed characters are seen.

X: Significant deformation and much centering.

(4) Adhesion to the base film When the anti-sticking layer is peeled off from a commercially available cellophane adhesive tape by 90' using a commercially available cellophane adhesive tape (manufactured by Chiban Co., Ltd.), the area of the anti-sticking layer adhered to the cellophane tape after peeling is less than 20%. ○,
The case where it was 20% or more and less than 50% was rated Δ, and the case where it was 50% or more was rated X.

[Example] Next, the present invention will be explained based on examples.

Example 1 Polyethylene terephthalate biaxially stretched film with a thickness of 5 μm (tensile modulus: 400 ki/mm2, Ra/Rt
:0.151m/1.30μm) with an anti-sticking layer of the following composition on one side with a dry thickness of 0.25μm.
Apply m. Drying was performed at 130'C for 2 minutes.

(A) Polyester copolymer ■ The dicarboxylic acid component is polycondensed using terephthalic acid/isophthalic acid (50,150 mol%) and the glycol component is polycondensed using ethylene glycol/neopentyl glycol (45,155) mol%, and has a molecular weight of about 20,000. Glass transition point 67°C, intrinsic viscosity 0.53
polyester copolymer.

Crosslinking agent: Coronate (trade name, manufactured by Nippon Polyurethane Co., Ltd.) was used as an adduct of 1′f-trimethylolpropane and 3 moles of 2.4-tolylene diisocyanate. The crosslinking agent has a solid content ratio of 2 to the polyester copolymer.
0 parts were blended.

(B) Organoborisiloxane: Epoxy polyether modified oil (trade name: TOμ Silicone 5F842'l)
(manufactured by Tomu Silicone Co., Ltd.) was used.

(A) and (B) were replaced with toluene/ethyl acetate (1/2>
The concentration was adjusted by diluting with a mixed solvent of (B)/(A) to give a ratio of 0.3.

After applying this coating liquid using a gravure coater and drying, further apply carnauba wax type 100 warm part, microcrystalline wax 30 parts by weight, vinyl acetate-ethylene copolymer type 15 part, and carbon black 20 parts by weight. A thermal transfer material shown in Table 1 was obtained by applying a heat-melting ink of 5 μm.

As shown in Table 1, the obtained thermal transfer material has good printing properties with no sticking and little noise during running.
Good characteristics were shown in both the line type and serial type.

Comparative Example 1 A thermal transfer material was obtained in the same manner as in Example 1 except for the varnish except for the crosslinking agent. When a non-crosslinked polyester copolymer was used by Organopolysiloxane Co., Ltd. and the coating thickness was similar, the properties were extremely poor as shown in Table 1.

Examples 2 to 4, Comparative Examples 3 to 4 Thermal transfer materials were obtained in the same manner as in Example 1 except that the ratio of (B>/(A>) was changed. As shown in Table 1, (B)/(
Comparative example 2) where the ratio of A> is less than the range of the present invention
Sticking and noise were significant, and printing performance was also poor. Moreover, when the range of the present invention was exceeded (Comparative Example 3), the adhesion of the coating film was insufficient or the coating film became sticky, making it impossible to achieve the objective of the present invention. (B)/(A>
Good characteristics were exhibited only when the value was within the range of the present invention.

Examples 5 to 7, Comparative Examples 4 to 5 Thermal transfer materials were obtained in the same manner as in Example 1 except that the thickness of the anti-sticking layer was changed.

As shown in Table 1, the coating thickness less than the range of the present invention (Comparative Example 4) caused significant sticking and noise, and the coating thickness exceeding the range of the present invention (Comparative Example 5) caused sticking and noise. However, the adhesion was somewhat insufficient, contaminating the thermal head, and the total thickness was thick, resulting in slightly poor printing performance. A thermal transfer material exhibiting good properties could be obtained only when the coating thickness was within the range of the present invention.

Example 8 PES Resin A604 (trade name, Takamatsu Yushi Co., Ltd.'!j), which is an aqueous dispersion having a reactive acrylic group, was used as a polyester copolymer (Polyester copolymer ■
).

As the organopolysiloxane, dimethylpolysiloxane oil (an emulsion with a viscosity of approximately 3,000,000 C-S> (To-μ Silicone 5M8705, trade name: To-μ Silicone Co., Ltd.) was used.

(B)/(A> was set to 0.3, 2 parts of p-toluenesulfonic acid was added to the polyester copolymer as a crosslinking catalyst, and the mixture was diluted with water to a predetermined concentration to prepare a coating liquid.

Polyethylene terephthalate with an intrinsic viscosity of 0.62 is about 2
It was melted at 80°C and extruded onto a cooling drum at about 60°C. Roughly stretched 3.5 times by roll stretching in the longitudinal direction at 80°C,
After corona discharge treatment in air, the water-based paint described above was applied. 3.5 in the horizontal direction at 110℃ continuously after application
Stretched twice and heat treated at 220°C, film thickness 5μm
A biaxially stretched polyester film having a coating thickness of 0.25 μm was obtained. Example 1 was applied to the opposite side of the film to the coated side.
A heat-melting ink was applied in the same manner as above to obtain a thermal transfer material. This thermal transfer material exhibited good properties with no problems in both line type and serial type printers.

Claims (1)

[Claims] A transfer ink layer that melts or sublimates when heated is provided on one side of the plastic film, and the other side is made of a mixture of (A) a crosslinked polyester copolymer and (B) an organopolysiloxane, and (B/A 1.) A thermal transfer material comprising an anti-sticking layer having a weight ratio of 0.01 to 8 and a thickness of 0.03 to 3 μm.