JP2946513B2 - Transferr for thermal recording - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transfer body for thermal recording.

[Prior Art] A transfer member for thermal recording used for recording in a method of transferring a color material by applying heat is basically composed of a base film and a heat-sensitive transfer layer, and a polyester film is used as the base film. Is often used. Japanese Patent Application Laid-Open No. Sho 60-174693 proposes that a biaxially oriented polyphenylene sulfide film (hereinafter abbreviated as PPS film) is used as a base film.

[Problems to be Solved by the Invention] However, a conventional thermosensitive recording transfer medium using a polyester film as a base film has poor heat resistance, and the polyester itself melts when the back surface is heated by the thermal head. In some cases, a so-called sticking phenomenon may occur. Such a problem causes a reduction in image quality and a reduction in sensitivity. Further, if the recording density is to be increased at a high speed, the above-mentioned problem is likely to occur.

In order to prevent sticking, the surface of the thermal transfer member that contacts the head is coated with a heat-resistant resin, but this is not sufficient.

On the other hand, a film using a PPS film as a base film is less likely to cause sticking than a film using a polyester film, but when printing at a high temperature and at a high speed, sticking cannot be completely prevented.

The present invention solves the above problems, that is, 30
It is an object of the present invention to provide a heat-sensitive recording transfer member which does not melt and does not cause sticking even when it comes into contact with a thermal head at 0 ° C. or higher, and is excellent in high speed and high resolution.

[Means for Solving the Problems] The present invention provides: (1) at least one surface of a polyphenylene sulfide film containing 30% by weight or more of compound fine particles of one or more metals selected from iron, cobalt and nickel. A laminated film having a layer, wherein a thermal transfer layer is provided on the surface of the laminated film which does not dissolve when immersed in a diphenyl ether solution heated and stirred at 230 ° C. for 5 seconds. Transcript. And (2) a laminated film having a layer containing 30% by weight or more of compound fine particles of one or more metals selected from iron, cobalt, and nickel on at least one surface of the polyphenylene sulfide film, and heated to 230 ° C. 30 to 90% by weight of fine particles of a compound of one or more metals selected from iron, cobalt, and nickel on the surface of the laminated film which does not dissolve when immersed in a stirred diphenyl ether solution for 5 seconds.
A transfer member for heat-sensitive recording, comprising a heat-sensitive transfer layer containing the above.

In the present invention, a polyphenylene sulfide film (hereinafter sometimes abbreviated as a PPS film) is a resin composition containing poly-P-phenylene sulfide as a main component, which is melt-molded, biaxially stretched, and heat-treated. Film.

The thickness of the film is preferably in the range of 1 to 20 μm.

In the present invention, the resin composition containing poly-P-phenylene sulfide as a main component (hereinafter, may be abbreviated as a PPS-based composition) refers to poly-P-phenylene sulfide.
A composition containing 90% by weight or more.

When the content of PPS is less than 90% by weight, the crystallinity and the thermal transition degree of the composition are reduced, and the heat resistance which is a feature of the film made of the composition is obtained. Impair dimensional stability, mechanical properties, etc.

The remaining less than 10% by weight of the composition may contain additives other than PPS, such as polymers, inorganic or organic fillers, lubricants, coloring agents, and ultraviolet respirants, as long as the object of the present invention is not impaired. Absent.

The melt viscosity of the resin composition is as follows: temperature 300 ° C., shear rate 2
Under 00sec ^-1 , 500-12,000 poise (more preferably 7
(Poise of 100 to 10,000 poise) is preferable in view of the moldability of the film.

The melt viscosity of the resin composition is equal to the melt viscosity of the finally obtained biaxially oriented poly-P-phenylene sulfide film.

In the present invention, poly-P-phenylene sulfide (hereinafter sometimes abbreviated as PPS) is defined as a repeating unit of 7
Structural formula other than 0 mol% (preferably 85 mol% or more) Means a polymer comprising the structural unit represented by Such components
If it is less than 70 mol%, the crystallinity and heat transition temperature of the polymer will be low, and the heat resistance, dimensional stability and mechanical properties, which are the characteristics of a film composed of a resin composition containing PPS as a main component, will be impaired.

If the amount of the repeating unit is less than 30 mol%, preferably less than 15 mol%, a unit containing a copolymerizable sulfide bond may be contained.

Furthermore, the PPS film of the present invention has a weight average value of the standard electrode potential E ゜ of all metals contained in the resin composition containing PPS as a main component of -1.5 V or less, and the total content of the metals. When the amount Y (unit: ppm) is 80 ≦ Y ≦ 700, and the weight X (unit: ppm) of the chloroform-extractable metal and the weight Z (unit: ppm) of the hot water-extractable metal are the PPS,
(1) with respect to the weight of the resin composition containing
It is preferable to satisfy the expression and the expression (2).

0 ≦ X ≦ (0.5Y−40) (1) Z ≦ 50 (2) Here, all metals contained in the film are IC
All metals that can be analyzed by P emission spectroscopy (high frequency inductively coupled plasma emission spectroscopy).

The standard electrode potential E ゜ is defined as Chemical-Data-Book
(Ed: GHAylward, TJV, Findlay), 2nd Ed (19
66), which is defined as a measure of the metal ionization tendency in the standard state and the oxidizing power (or reducing power) of the redox system constituting the electrode reaction.

As a method for extracting chloroform, a method is used in which 10 g of a pulverized film or polymer of 200 to 250 mesh is placed in a Soxhlet extractor and extracted with 100 g of chloroform for 120 hours.

The method of hot water extraction is as follows: 10 g of a crushed film or polymer of 200 to 250 mesh is put in a titanium autoclave together with 300 g of ion-exchanged water at 180 ° C. for 20 minutes.
After extraction while stirring for a time, the mixture is filtered through a 0.5 μ filter, and the filtrate is concentrated using a 5 to 50-fold rotary evaporator or the like.

In the thermal recording transfer body of the present invention, the laminated film serving as the base film is provided with a metal compound layer containing fine particles of one or more metals selected from iron, cobalt and nickel on at least one surface of the PPS film.

The compounds of the present invention are oxides, chlorides,
Hydroxides, carbonates, nitrates, and sulfates are preferred.Examples include iron oxide, iron chloride, iron nitrate, iron sulfate, iron hydroxide, cobalt chloride, nickel chloride, and the like. Those that are stable to are particularly preferred. The compound is preferably in the form of particles having an average particle diameter of 5 μm or less.

The oxide is contained in the metal compound layer of the present invention in an amount of 30% by weight or more. If the amount is less than 30% by weight, infusibilization cannot be achieved, and the sticking of the transfer body for thermal recording, which is the object of the present invention, cannot be prevented. The remaining composition of the layer is preferably a resin such as urethane, acrylic, epoxy or the like, but may also contain additives such as a flame retardant, a colorant, a dispersant and the like.

The layer thickness (B, B ') with respect to the thickness (A) of the PPS film is 0.025 ≦ B / A ≦
0.4, when the layers are provided on both sides, 0.05 ≦ (B + B ′) /
The range of A ≦ 0.6 is preferred for the purpose of the present invention. Further, the thickness of the laminated film is preferably in the range of 1 to 20 μm.

In order to achieve the object of the present invention, it is necessary that the laminated film used for the transfer body for thermal recording of the present invention is insoluble in diphenyl ether heated to 230 ° C. The term “insoluble” as used herein means that the laminated film heated to a temperature of 230 ° C. ± 5 ° C. and immersed in a stirred diphenyl ether solution for 5 seconds does not dissolve. The laminated film insoluble in the diphenyl ether becomes infusible even at a high temperature of 400 ° C. or higher. Further, the heat shrinkage at 300 ° C. is preferably set to 10% or less.

The transfer member for thermal recording according to the present invention comprises a base film and a thermal transfer layer. The heat-sensitive transfer layer is a layer formed by applying a heat-sensitive transfer ink such as a hot-melt ink or a heat-sublimable ink to a film. The thermal transfer ink comprises a coloring component and a binder component, and if necessary, a softening agent, a flexible agent, a smoothing agent, a dispersing agent, a surface forming agent, and the like as additional components. The thickness of the thermal transfer layer is, for example,
It is 0.2 to 20 μm, preferably 0.5 to 10 μm.

As the binder component, well-known waxes such as carnauba wax, paraffin wax, and ester wax, cellulose-based resins, vinyl-based resins, and various polymers having a low melting point are useful. Organic or inorganic pigments or dyes are used.

The object of the present invention can also be attained by including 30 to 90% by weight of the metal compound fine particles according to the present invention in the heat-sensitive transfer layer. If the amount of the compound is less than 30% by weight, infusibilization cannot be achieved, and sticking of the transfer body for thermal recording, which is the object of the present invention, cannot be prevented. Conversely, if the content exceeds 90% by weight, the heat-sensitive transfer layer becomes brittle, and the recording speed and print quality deteriorate.

When providing a heat-sensitive transfer layer in the laminated film of the present invention,
It may be a laminated surface or a PPS film surface.

The layer containing the metal compound according to the present invention may also serve as the anti-sticking layer.

Next, a method for manufacturing the transfer body for thermal recording of the present invention will be described.

The PPS used in the present invention is obtained by reacting alkali sulfate and paradihalobenzene in a polar solvent at high temperature and high pressure. In particular, sodium sulfide and paradiclobenzene
The reaction is preferably performed in an amide-based high-boiling-point polar solvent such as methylpyrrolidone. In this case, in order to adjust the degree of polymerization, it is most preferable to add a so-called polymerization aid such as a caustic alkali or an alkali metal carboxylate and react at 230 to 280 ° C. The pressure and polymerization time in the polymerization system are appropriately determined depending on the type and amount of the auxiliary agent used, the desired degree of polymerization, and the like. The obtained powdery or granular polymer is washed with water or / and a solvent to separate a by-product salt, a polymerization aid, an unreacted monomer and the like.

Further, the obtained polymer is optionally used in an aqueous solution of a metal acetate having a standard electrode potential referred to in the present invention in an aqueous solution of 30 to 10 to 30 to 30.
After stirring for 10 to 60 minutes at a temperature of 0 ° C, add 3 times with ion-exchanged water.
Drying after repeating washing at a temperature of 0 to 80 ° C. several times is preferable because the heat resistance and mechanical properties of the film made of the polymer are further improved.

The polymer is formed into a film by a known method.

A biaxially oriented film is obtained by obtaining a non-oriented, amorphous sheet of the polymer, and biaxially stretching and heat-treating by a known method. Stretching is performed at 90 to 110 ° C. in the longitudinal direction and the width direction in a range of 3.0 to 4.5 times. The heat treatment is performed at a fixed temperature or a limited shrinkage of 15% or less for 1 to 60 seconds in a range of 240 ° C. to a melting point. Further, the film may be relaxed in one or two directions to improve the thermal dimensional stability of the film.

 Next, a method for manufacturing a laminated film will be described.

As described above, as the metal compound used in the present invention, iron oxide, iron chloride, iron nitrate, iron hydroxide, cobalt chloride, nickel chloride and the like can be used.

The method of laminating the compound of the metal on the PPS film is a method of dispersing the compound of the metal in water or an appropriate solvent, and applying the compound of the metal to a resin such as a urethane-based resin, an acrylic-based resin, or an epoxy-based resin. There is a method of mixing and dispersing to 30% by weight or more and applying it to a PPS film. The latter method is preferable in consideration of the dispersibility of the metal compound and the peeling of the metal compound layer. It is particularly preferable to use iron oxide from the viewpoint of tackiness (tackiness) and workability of the coated surface after coating.

Prior to the above coating, it is preferable to perform a surface treatment such as a corona discharge treatment or a plasma treatment on the PPS film.

Examples of a method for applying the above composition include a gravure roll method and a reverse coater method. The method of application on the table includes a metering bar, applicator,
Alternatively, it can be applied with a glass rod or the like. The drying of the solvent after the application differs depending on the type of the solvent to be used. Usually, a condition under which the residual solvent is completely eliminated at a temperature near the boiling point of the solvent is selected.

The laminated film obtained as described above is subjected to a heat treatment in the presence of oxygen for further improving the heat resistance. The heat treatment is performed at a temperature of 200 ° C. to 300 ° C. for 1 second in the presence of oxygen.
Choose optimal conditions for tens of hours. For example, (1) 5-30 hours at a temperature of 200-250 ° C (2) 1-60 minutes at a temperature of 260-280 ° C (3) 1-60 seconds at a temperature of 290-300 ° C is there.

The heat treatment may be in a fixed length or in a free state. In the case of long products, there are methods such as heat treatment in a hot air oven or the like in the state of a roll, continuous heat treatment using a heat treatment device such as a tenter or a coater, or heat treatment by a method combining both.

The heat treatment temperature is (1) among the above (1) to (3).
The lower temperature and the longer time are preferable because the heat shrinkage at 300 ° C. is lower.

Next, the laminated film obtained above is used as a base film to form a heat-sensitive transfer layer. The heat-sensitive transfer ink is as described above, and may be formed by a general-purpose coating method such as hot-melt coating on one side of the film or gravure, reverse, or a slit die as a solution dissolved in a solvent. it can.

When the heat-sensitive transfer layer contains fine particles of the metal compound according to the present invention, they are mixed and dispersed in the heat-sensitive transfer ink, and PPS is used.
The surface of the film or the laminated film is coated by the above method.

Further, the base film may be subjected to a surface treatment such as a corona discharge treatment or a plasma treatment in advance.

[Effects of the Invention] Since the transfer member for thermal recording of the present invention has the above-mentioned structure, the base film becomes infusible, and even if a high-speed and high-density thermal bed is used, it is stable without causing a so-called sticking phenomenon. It is now possible to keep the recorded records continuously.

[Action] PPS serving as a base film of the transfer body for thermal recording of the present invention
It is not clear why the metal compound-containing layer is provided on at least one side of the film, or why the instant heat resistance is remarkably improved by including the metal compound in the transfer ink layer of the transfer body for thermal recording, but is roughly as follows. Can be considered.

That is, when the above-mentioned laminated film or PPS film is heated by the thermal head of the thermal transfer device, the heat causes the metal compound to become a catalyst, and crosslinking of the PPS film occurs extremely rapidly, so that the PPS is melted. It is thought that it will be in an infusible state sooner.

[Measurement method and evaluation criteria used in the description of the present invention] (1) Solubility in diphenyl ether A 10 mm x 20 mm film sample was immersed in a diphenyl ether solution kept at 230 ° C ± 5 ° C for 5 seconds with stirring, and its appearance was measured. Was observed.

(2) Thermal recording test A recording test was performed with a thermal transfer device having a thermal head density of 16 lines / mm and a pulse width of 0.7 msec, and evaluated according to the following criteria.

：: Sticking does not occur, and good image quality is stable for a long time.

X: Sticking occurs and / or print quality is significantly reduced.

Example Next, an example will be described in detail.

Example 1 (1) PPS film used in the present invention A 9-μm-thick biaxially oriented PPS film “TORELINA” type 1000 manufactured by Toray Industries, Inc. was used. Further, both surfaces of the film were subjected to a corona discharge treatment at 6000 J / m ² , and this film was referred to as Film-1.

(2) Adjustment of laminated film Acrylic polyol resin “KOTAX” LH608 (manufactured by Toray Industries, Inc., solid content concentration 50% by weight) and isocyanate “Sumidur” N75 (manufactured by Sumitomo Bayer, solid content concentration 75% by weight) Oxidized second fine particles having an average particle size of 0.4μ
It was added at a ratio of 80% by weight based on the total solid content including iron fine particles, and kneaded with a ball mill for 32 hours. The obtained paint was diluted with ethyl acetate to a solid content of 30% by weight. Next, the above paint was applied to film-1 by the gravure roll method.
Coated on both sides. Drying conditions were 100 ° C. for 1 minute. Also, the coating thickness is 0.
It was 7 μm. The laminated film was heat-treated at a temperature of 240 ° C. for 16 hours. (This is referred to as laminated film-1.) Laminated film-1 was insoluble in diphenyl ether at 230 ° C. The heat shrinkage at 300 ° C. for 10 minutes was 0%.

(3) Preparation of transfer body for thermal recording A transfer ink layer consisting of carnauba wax 30 parts ester wax 35 parts carbon black 12 parts polytetrahydrofuran 10 parts silicone oil 3 parts was heated on a surface of the laminated film-1 by a heating roll. It was applied to a thickness of 6 μm by a melt coating method.

Example 2 The transfer ink used in Example 1 was made to contain 50% by weight of oxidized second fine particles having an average particle size of 0.4 μm based on the total solid content including ferric oxide, and was applied to the surface of the laminated film of Example 1. Example 1
Was applied under the following conditions.

Comparative Example 1 A transfer ink was formed under the conditions of Example 1 on the surface of Film-1.

Comparative Example 2 Film-1 was heat-treated at a temperature of 240 ° C. for 100 hours, and a transfer ink was formed on the surface of the film under the conditions of Example 1.

Evaluation The transfer materials for thermal recording of the present invention of Examples 1 and 2 were able to obtain very good image quality stably over a long period of time and did not generate sticking at all.

On the other hand, in the case of Comparative Example 1, sticking occurred and the running property was poor. In Comparative Example 2 in which the film was oxidized by the heat treatment, the base film was brittle and broke immediately after running.

Claims (2)

(57) [Claims] 1. A laminated film comprising a polyphenylene sulfide film provided on at least one side with a layer containing 30% by weight or more of fine particles of a compound of at least one metal selected from iron, cobalt and nickel, wherein the temperature is 230 ± 5 ° C. A heat-sensitive transfer layer, wherein a heat-sensitive transfer layer is provided on the surface of a laminated film that does not dissolve when immersed in a heated and stirred diphenyl ether solution for 5 seconds. 2. A laminated film comprising at least one surface of a polyphenylene sulfide film provided with a layer containing at least 30% by weight of fine particles of a compound of at least one metal selected from iron, cobalt and nickel, wherein the layer has a temperature of 230 ± 5 ° C. On the surface of a laminated film that does not dissolve when immersed in a diphenyl ether solution heated and stirred for 5 seconds, fine particles of a compound of one or more metals selected from iron, cobalt and nickel
A transfer body for heat-sensitive recording, comprising a heat-sensitive transfer layer containing at least 90% by weight or more.