JP3255439B2 - Reversible thermosensitive recording material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversible thermosensitive recording material capable of repeatedly forming and erasing an image by utilizing a reversible change in transparency of a thermosensitive layer depending on the temperature.

[0002]

2. Description of the Related Art In recent years, a reversible thermosensitive recording material which can form a temporary image and erase the image when it becomes unnecessary has been attracting attention. A typical example is a glass transition temperature (Tg) of 50 to 60 ° C to 8 ° C.
A reversible thermosensitive recording material is known in which an organic low molecular weight substance such as a higher fatty acid is dispersed in a resin base material such as a vinyl chloride-vinyl acetate copolymer having a low glass transition temperature of less than 0 ° C. JP-A-54-119377, JP-A-55-1
No. 54198).

When a heat roller, a hot pen, or the like is used as a heating method at the time of image formation and erasing, and only heat is applied without applying much pressure, image formation is repeated.
Erasing does not cause a problem in durability. However, when applying pressure and heating at the same time using a thermal head, etc., the resin base material around the organic low molecular substance fine particles is deformed as the image formation and erasure is repeated, and the organic low molecular substance dispersed finely There is a disadvantage that the particles gradually become larger in size, the effect of scattering light is reduced, the turbidity is reduced, and finally the image and the contrast are reduced.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks and provides a reversible thermosensitive recording material in which a transparent state and a cloudy state change reversibly depending on temperature. An object of the present invention is to provide a reversible heat-sensitive recording material in which the turbidity is less reduced even when image formation and erasure are performed by using a heating means for simultaneously applying pressure, and in which the durability is repeatedly improved.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for manufacturing a semiconductor device comprising the steps of:
In a reversible thermosensitive recording material having, as a main component, a resin base material and an organic low-molecular substance dispersed in the resin base material, and a heat-sensitive layer in which transparency changes reversibly depending on temperature, the resin base material is characterized in that the or transparent particles do not have colored particles having at least on the surface of the crystal nuclei-forming ability of a molecule consisting of an organic low-molecular substances not contain alkyl phenol resin is used is there.

That is, a reversible thermosensitive element comprising, as a main component, a resin base material and an organic low-molecular substance dispersed in the resin base material, and a heat-sensitive layer whose transparency reversibly changes depending on temperature. In the recording material, as a result of intensive examination of the resin base material,
By using a phenolic resin, durability against repeated image formation and erasure by a heating means such as applying a pressure of a thermal head and heating at the same time is improved, and high white turbidity and high contrast image are formed. It was found that a reversible thermosensitive recording material was obtained.

In the present invention, it is not clear why the use of a phenol resin as the resin base material improves the durability of image forming and erasing by heating means such as a thermal head. Since the mechanical strength and hardness are extremely high, even if recording and erasing are repeated using a heating means such as a thermal head that simultaneously applies heat and pressure, deformation of the resin base material existing around the organic low-molecular substance fine particles is small. It is presumed that durability is improved because the organic low-molecular substance is maintained as fine particles.

The reversible thermosensitive recording material of the present invention utilizes the change in transparency (transparent state, cloudy opaque state) as described above. The difference between this transparent state and cloudy opaque state is presumed as follows. . That is, (i) in the case of transparency, the particles of the organic low-molecular substance dispersed in the resin base material are composed of large particles of the organic low-molecular substance, and the light incident from one side is not scattered and is opposite. (Ii) In the case of cloudiness, the particles of the organic low-molecular substance are composed of polycrystals composed of fine crystals of the organic low-molecular substance, and the crystal axes of the individual crystals Is oriented in various directions, so that light incident from one side is refracted many times at the interface between the crystals of the organic low-molecular substance particles, and is scattered, so that it appears white.

In FIG. 1 (which shows a change in transparency due to heat), a heat-sensitive layer mainly composed of a resin base material and an organic low-molecular substance dispersed in the resin base material is, for example, T
_At a room temperature of ₀ or less, it is cloudy and opaque. This is called temperature T ₂
When the temperature is returned to room temperature below T ₀ , the film remains transparent. This is from temperature T ₂ to T ₀
It is considered that the crystal grows from a polycrystal to a single crystal through the semi-molten state of the organic low-molecular substance until the following.
Upon further heating to T ₃ or more temperature becomes translucent state intermediate between the maximum transparency and the maximum opacity. Next, when the temperature is lowered, the state returns to the original cloudy and opaque state without taking the transparent state again. This after low-molecular organic material is melted at a temperature T ₃ or more, presumably because the polycrystals precipitated by being cooled. When the opaque state is heated to a temperature between T _{1 and} T ₂ and then cooled to room temperature, that is, a temperature lower than T ₀ , an intermediate state between transparent and opaque can be obtained. Also, by returning to room temperature After heating to be again T ₃ or more temperature which became clear at the normal temperature, the flow returns to cloudy opaque state again. That is, both opaque and transparent forms at room temperature and intermediate states thereof can be taken. Therefore,
By selectively applying heat, the heat-sensitive layer can be selectively heated to form a cloudy image on a transparent background and a transparent image on a cloudy background, and the change can be repeated many times.

In order to prepare the reversible thermosensitive recording material used in the present invention, generally, (1) a resin base material and an organic low-molecular substance are used.
A dispersion in which fine particles of an organic low-molecular substance are dispersed in a solution in which components are dissolved or (2) a resin base material solution (a solvent that does not dissolve at least one of the organic low-molecular substances) is used as a plastic. What is necessary is just to apply | coat and dry on a support body, such as a film, a glass plate, and a metal plate, and to form a laminated thermosensitive layer. The solvent for preparing the heat-sensitive layer or the heat-sensitive recording material can be variously selected depending on the type of the resin base material and the organic low-molecular substance, and examples thereof include tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, chloroform, carbon tetrachloride, ethanol, toluene, and benzene. No. In addition, of course, when a dispersion is used,
Even when a solution is used, in the heat-sensitive layer obtained, the organic low-molecular substance is precipitated as fine particles and exists in a dispersed state.

The phenol resin used as the resin base material includes phenol, cresol, xylenol, p-alkylphenol, p-phenylphenol, chlorophenol, bisphenol A, phenolsulfonic acid,
It is a polymer compound obtained by adding and condensing an aldehyde such as formalin or furfural to a compound having phenolic -OH such as resorcin, and can be classified as follows. Phenol / formalin resin Cresol / formalin resin Modified phenolic resin Phenol / furfural resin Resorcinol resin In the present invention, alkyl in modified phenolic resin
Use phenolic resin. Further, when the substrate is made of a material such as an Al vapor-deposited layer, which has a low adhesive strength to a resin, an adhesive layer must be provided between the support and the heat-sensitive recording layer.

On the other hand, as the organic low-molecular substance, any substance that changes from polycrystal to single crystal by heat in the recording layer (a substance that changes within the temperature range of T _{1 to} T ₃ shown in FIG. 1) may be used. Generally, the melting point is 30 to 200 ° C, preferably 50 to 150.
A temperature of about ° C is used. Such organic low molecular weight substances include alkanol; alkane diol; halogen alkanol or halogen alkane diol; alkylamine; alkane; alkene; alkyne; halogen alkane; halogen alkene; halogen alkyne; cycloalkane; cycloalkene; cycloalkyne; Unsaturated mono- or dicarboxylic acids or esters thereof,
Amides or ammonium salts; saturated or unsaturated halogen fatty acids or their esters, amides or ammonium salts; aryl carboxylic acids or their esters, amides or ammonium salts; halogen allyl carboxylic acids or their esters, amides or ammonium salts; thioalcohols Thiocarboxylic acids or their esters;
Amines or ammonium salts; carboxylic acid esters of thioalcohols and the like. These may be used alone or in combination of two or more. The carbon number of these compounds is 1
0-60, preferably 10-38, particularly preferably 10-30. The alcohol group in the ester may be saturated, may not be saturated, and may be halogen-substituted. In any case, the organic low-molecular substance is at least one kind of oxygen, nitrogen, sulfur and halogen in the molecule, for example, -OH, -COOH, -CONH, -COOR,-
_{NH, -NH 2, -S -,} - S-S -, - O-, is preferably a compound containing a halogen and the like.

More specifically, these compounds include lauric acid, dodecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, behenic acid, nonadecanoic acid, araginic acid, henicosanoic acid, tricosanoic acid, lignoceric acid, pentacosanoic acid. Higher fatty acids such as acid, cerotic acid, heptacosanoic acid, montanic acid, melicic acid and oleic acid; esters of higher fatty acids such as methyl stearate, tetradecyl stearate, octadecyl stearate, octadecyl laurate, tetradecyl palmitate and dodecyl behenate C ₁₆ H ₃₃ —OC ₁₆ H ₃₃ , C ₁₆ H ₃₃ —S—C ₁₆ H _{33;
, C 18 H 37 -S-C} 18 H 37, C 12 H 25 -S-C 12
_{H 25, C 19 H 39 -S} -C 19 H 39, C 12 H 25 -S-
S-C ₁₂ H _25, And ether or thioether. Among them, in the present invention, higher fatty acids, especially palmitic acid, pentadecanoic acid,
Higher fatty acids having 16 or more carbon atoms, such as nonadecanoic acid, arachinic acid, heicosanoic acid, tricosanoic acid, stearic acid, behenic acid, and lignoceric acid, are preferred, and have 16 to 24 carbon atoms.
Are more preferred.

The ratio between the organic low-molecular substance and the resin base material in the heat-sensitive layer is preferably about 2: 1 to 1:16, more preferably 1: 1 to 1: 3 by weight. When the ratio of the resin base material is less than this, it becomes difficult to form an organic low-molecular substance in a film held in the resin base material. Becomes difficult.

[0015] In addition to the above components, additives such as a surfactant and a high-boiling solvent can be added to the heat-sensitive layer in order to facilitate formation of a transparent image. Specific examples of these additives are as follows. Examples of high boiling point solvents; tributyl phosphate, tri-2-phosphate
Ethylhexyl, triphenyl phosphate, tricresyl phosphate, butyl oleate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, diisononyl phthalate , Dioctyldecyl phthalate, diisodecyl phthalate, butylbenzyl phthalate,
Dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, di-2 azelate
-Ethylhexyl, dibutyl sebacate, di-2-ethylhexyl sebacate, diethylene glycol dibenzoate, triethylene glycol di-2-ethyl butyrate, methyl acetyl ricinoleate, butyl acetyl ricinoleate, butyl phthalyl butyl glycolate, acetyl citric acid Tributyl.

Examples of surfactants and other additives: polyhydric alcohol higher fatty acid ester; polyhydric alcohol higher alkyl ether; polyhydric alcohol higher fatty acid ester, higher alcohol, higher alkylphenol, higher fatty acid higher alkylamine, higher fatty acid amide Lower olefin oxide adducts of fats and oils or polypropylene glycol; acetylene glycol; Na, Ca, Ba or Mg salts of higher alkylbenzene sulfonic acids; higher fatty acids, aromatic carboxylic acids, higher fatty acid sulfonic acids, aromatic sulfonic acids, monoesters of sulfuric acid Or Ca, Ba or Mg salts of phosphoric acid mono- or di-esters; low sulfated oils; poly long chain alkyl acrylates; acrylic oligomers; poly long chain alkyl methacrylates; Chromatography copolymers; styrene-maleic anhydride copolymer; olefin-maleic anhydride copolymer.

The thickness of the heat-sensitive layer is preferably 1 to 30 μm,
2-20 μm is more preferred. If the heat-sensitive layer is too thick, heat distribution within the layer will occur, making it difficult to achieve uniform transparency. On the other hand, if the heat-sensitive layer is too thin, the turbidity decreases and the contrast decreases. Further, the turbidity can be increased by increasing the amount of the organic low-molecular substance in the heat-sensitive layer.

Further, a protective layer may be provided on the heat-sensitive layer of the present invention in order to prevent the surface from being deformed by the heat and pressure of the heating means by a writing method such as a thermal head or the like, and to reduce the transparency of the transparent portion. good. A protective layer (having a thickness of 0.1 mm) laminated on the thermosensitive layer.
Materials of silicone rubber, silicone resin (described in JP-A-63-221087), and polysiloxane graft polymer (JP-A-63-210 μm)
317385), an ultraviolet curable resin or an electron beam curable resin (described in JP-A-2-566).

Further, in order to protect the reversible recording material from a solvent, a monomer component and the like of the protective layer forming liquid, an intermediate layer such as polyamide can be provided between the protective layer and the reversible recording material. The thickness of the intermediate layer varies depending on the application, but is 1 to 20
About μm is preferable. Below this, the protection effect decreases, and above this, the thermal sensitivity decreases.

[0020]

EXAMPLES All parts and percentages herein are by weight. Example 1 9 parts of behenic acid 1 part of eicosane diacid 1 part of alkylphenol resin (PS2880, Gunei Chemical Industry Co., Ltd.) 30 parts of diphthalic acid on a film in which an Al layer of about 40 nm thickness is provided on a polyester film of about 50 μm thickness A solution consisting of 2 parts of ethylhexyl 3 parts of tetrahydrofuran 150 parts of toluene 15 parts is coated with a wire bar and dried by heating.
An m-thick heat-sensitive layer was provided.

Example 2 9 parts of behenic acid 1 part of eicosane diacid 1 part of alkylphenol resin (PS2851 by Gunei Chemical Industry Co., Ltd.) 30 parts of phthalate on a film in which an Al layer having a thickness of about 40 nm is provided on a polyester film having a thickness of about 50 μm A solution consisting of 3 parts of di-2ethylhexyl acid, 150 parts of tetrahydrofuran and 15 parts of toluene was applied with a wire bar, dried by heating, and dried at about 5 μm.
An m-thick heat-sensitive layer was provided.

COMPARATIVE EXAMPLE On a film in which an Al layer having a thickness of about 40 nm was provided on a polyester film having a thickness of about 50 μm, 9 parts of behenic acid 1 part of eicosane diacid 1 part of vinyl chloride-vinyl acetate copolymer VYHH 30 parts of diphthalic acid A solution consisting of 3 parts of ethylhexyl, 150 parts of tetrahydrofuran, and 15 parts of toluene is applied with a wire bar, dried by heating, and dried at about 5 μm.
An m-thick heat-sensitive layer was provided.

A solution consisting of 10 parts of a polyamide resin (CM8000, manufactured by Toray Industries, Inc.) and 90 parts of ethyl alcohol was applied on each of the heat-sensitive layers prepared as described above with a wire bar, and dried by about 0.5 μm.
An intermediate layer having a thickness of m is provided, and a solution consisting of 10 parts of a 75% butyl acetate solution of a urethane acrylate-based ultraviolet curable resin (Unidik C7-157 manufactured by Dainippon Ink and Chemicals, Inc.) and 10 parts of toluene is applied by a wire bar. After heating and drying, 8
A protective layer having a thickness of about 2 μm was formed by curing with an ultraviolet lamp of 0 W / cm to form a reversible thermosensitive recording medium.

Using the reversible thermosensitive recording material prepared as described above, a forced test condition (applied power of 1.0 W, applied pulse width of 1.0 W / mm) using a thermal head of 8 dots / mm and increasing the applied energy from normal printing conditions was used. 0.7mse
After printing with c) and clouding, heat roller (80
８５85 ° C., 10 mm / min), clearing and erasing were performed, and printing-erasing was repeated 10 times under the same conditions. = 514 are shown in FIGS. 2, 3, and 4. FIG. In the comparative example, the density of the image portion (opaque portion) was high and almost no turbidity was observed after 10 printings, but in Examples 1 and 2, the density of the image portion (opaque portion) was low and the transparency was high and the printing was high up to 10 times. Maintains contrast.

Example 3 A vinyl chloride-vinyl acetate-phosphate ester copolymer (Denka Vinyl 1000P, manufactured by Denki Kagaku Kogyo Co., Ltd.) was formed on a film in which an Al layer having a thickness of about 40 nm was provided on a polyester film having a thickness of about 50 μm. A solution consisting of 80 parts of methyl ethyl ketone was applied with a wire bar and dried by heating.
An adhesive layer having a thickness of 5 μm was provided, and the same solution as in Example 2 was applied using a wire bar and dried by heating to provide a heat-sensitive layer having a thickness of about 5 μm. Further, a solution consisting of 10 parts of a 75% butyl acetate solution of a urethane acrylate-based ultraviolet-curable resin (Unidic C7-157 manufactured by Dainippon Ink and Chemicals, Inc.) and 10 parts of toluene was applied by a wire bar, and dried by heating.
A protective layer having a thickness of about 2 μm was formed by curing with an ultraviolet lamp of 0 W / cm to form a reversible thermosensitive recording medium.

A grid-shaped cut is made on each surface of the recording medium of Example 3 and the recording medium of Example 2 prepared as described above with a cutter knife, and a cellophane tape (Nichiban) is adhered to the surface. Was peeled off and the adhesion test of the heat-sensitive recording layer was carried out.
The recording layer of Example 3 was not peeled off from the interface with the layer.

[0027]

In the resin matrix using a reversible thermosensitive recording material as is apparent from this example, according to the present invention, Al as the resin base material
The use of a kill phenol resin has the effect of improving the durability due to its heat resistance, increasing the white turbidity and forming a high-contrast image.

[Brief description of the drawings]

FIG. 1 is a diagram showing a change in transparency of a reversible thermosensitive recording material according to the present invention due to heat.

FIG. 2 is a graph showing image density when recording and erasing are repeatedly performed using the reversible thermosensitive recording material of Example 1 of the present invention.

FIG. 3 is a graph showing image density when recording and erasing are repeatedly performed using the reversible thermosensitive recording material of Example 2 of the present invention.

FIG. 4 shows a reversible thermosensitive recording material of a comparative example of the present invention,
5 is a graph showing image density when recording and erasing are repeatedly performed.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Kawaguchi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Fumito Masufuchi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Toru Nogaki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-4-299177 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B41M 5/36

Claims (2)

(57) [Claims] 1. A reversible sensor comprising a resin base material and a heat-sensitive layer whose main component is a resin base material and an organic low-molecular substance dispersed in the resin base material and whose transparency changes reversibly depending on temperature. in thermal recording material, the resin base material, also did not contain or transparent particles do not have colored particles having at least on the surface of the crystal nuclei-forming ability of a molecule consisting of the organic low-molecular material, alkyl
Reversible thermosensitive recording material characterized in that Le phenolic resin. 2. The reversible thermosensitive recording material according to claim 1, wherein an adhesive layer is provided between the support and the thermosensitive layer.