DE19953569A1 - Reversible thermographic medium used on sleeve of diskette or record or label of magnetic tape cassette for showing (part of) the stored information has limited retarded initial transparency temperature - Google Patents

Abstract

In a reversible thermographic medium with a substrate and heat-sensitive layer that undergoes a reversible change in transparency or color with temperature, the novelty is that the change in the retarded initial transparency temperature is \} 5 deg C. Independent claims are also included for: (a) a reversible thermographic medium with a substrate and heat-sensitive layer that undergoes a reversible change in transparency or color with temperature, which consists of an organic material of low molecular weight dispersed in a matrix resin, in which the matrix resin is a crosslinked mixture of a thermoplastic resin containing hydroxyl groups, a linear isocyanate and a cyclic isocyanate; (b) a similar medium, in which the matrix is a crosslinked urethane resin based on polycarbonate; (c) a process for writing and erasing an image in such a medium by heating.

Description

The present invention generally relates to a reversible recording medium and more in detail on a reversible, thermosensitive or thermosensitive recording medium, which is able to repeatedly form images and by using a reversible change the transparency or the color of a heat-sensitive layer with high image contrast and improved erasability.

A variety of information recording media have been ent Wraps to meet the requirements for expansion and modification the scope of information. A reversible, heat-sensitive recording medium capable of Transparency or hue reversible with the temperature Request to change has recently attracted much attention drawn. In addition, the image formation and deletion under ver relatively low cost and without complicated development achieved.

As an illustrative example of reversible heat-up Drawing media are known recording media, the organi low molecular weight materials include higher fatty acids found in matrix resins such as vinyl chloride Vinyl acetate copolymers are dispersed (Japanese, open laid-open patent application No. 55-154198).

In this recording medium, however, the temperature is  rich in which the medium is transparent or the transparency Temperature range narrow (about 2 ° -4 ° C). This is for controlling the Temperature unsatisfactory to achieve image recordings, which use the above-mentioned reversibility.

In view of the above problem, in Japanese, have been open No. 2-1363 and 3-2089 some of Present inventors provided several recording materials beat. They disclose that when using higher fatty acids ren, aliphatic dicarboxylic acids and their combination as Ge the temperature range in which transparency (transparency Temperature range) is present, is extended to about 20 ° C. and the image erasure can be achieved relatively easily can.

Methods and devices have also been explored to date continue to produce miniaturized and cheaper devices in which both the formation and the erasure of the Ab Formations with a single thermal print head or Wärmeabbil training head and without any additional deletion unit performed can be.

However, if in the course of the investigation, the heating time to a for a short time, such as several milliseconds, like a thermal print head, deficits showed up. After this they were heated for only so short a time, and after a long time Storage at a temperature above room temperature, it comes with known material systems of the recording medium to Schwie how to reduce the erasability (or the Ability to become transparent) and insufficient image contrast.

Referring to Fig. 1, the reduction of erasability and image contrast will be described below.

As long as the erasure of formed images is not made long (short) after heating, for example, within several tens of minutes, the images can be erased down to the base transparency even if the heating time with a thermal head is reduced to several milliseconds. Also in this case, since the energy range for achieving the basic transparency is relatively wide, as shown in Fig. 1 ge, the production of transparency (or erasure) can be satisfactorily performed with sufficient margin, even if the erasure conditions change, such , As the ambient temperature, and when a concomitant change in the necessary input energy is caused.

If, on the other hand, the deletion of shaped images after a longer Period under the same deletion conditions as immediately after heating, the deletion can neither the Basic transparency still reach the previous, broad energy reach a satisfactory level of transparency in order to achieve satisfactory transparency chen.

It is considered that the above reduction in the Erasable on the change in the material properties of the Matrix resin lies in the reversible, heat-sensitive Recording layer is included. When a polymer material after being scared off over his glass transition temp temperature was heated, the polymer material, as is general is known, not in its characteristic or stable Condition return, and may be at temperatures below the glass transition temperature in the stable state only after a lan return to the period.

This is known as enthalpy relaxation. Examples of sol Changes in material properties include known the increase in glass transition temperatures and specific Densities. In the above cases, the reduction of the Erasability thus the increase in glass transition temperatures attributed to the matrix resin.  

To prevent the reduction of erasability are a Method of admixing a special, radiation-curing Resin (Japanese Laid-Open Patent Application No. 8-72416) and another method of receiving a reactive poly merart into a reversible, heat-sensitive recording Layer (Japanese Laid-Open Patent Application No. 10-100547) been proposed. Although the erasability by this Ver Driving is improved to some extent, this is improvement not sufficient to keep up with the ever-increasing Data processing speed and the associated Decrease the heating time of a thermal print head to keep up, resulting in unsatisfactory deletability and an unbefriedi gender image contrast caused.

As in the above method, in the '416 application Bart is the radiation curable resin with a matrix resin is only mixed, but no cross-linking between them is present, there is still the difficulty of Reduction of erasability with repeated use.

If, in the method disclosed in the '547 application, the Resin also cured by ultraviolet light radiation is, then only the proportion of radiation-curing Resin crosslinked. The erasability is repeated at repeated Ge need diminished again. Although further with an electron beam irradiation method a further improved erasable is reached, there are disadvantages in this process, such as about a large-scale and expensive plant.

There was still another method for preventing the Reduction of erasability for repeated use pre-existing in which a vinyl chloride-vinyl acetate-vinyl alcohol-Co polymer with an isocyanate compound in a matrix resin ver becomes wet (Japanese Laid-Open Patent Application No. Hei. 3-227688). Because in this process a fairly rigid chain structure is used in the isocyanate compound, has a ver  improved durability. However, the problem remains where the erasability immediately after the Image forming and also decreases after prolonged storage.

It is also the use of polyurethane resin as matrix resin disclosed, with a glass transition temperature of 35 ° C or more. However, this method has difficulties such as the ver a relatively high reduction in erasability after a longer period Storage and unsatisfactory durability with repeated Use (Japanese Laid-Open Patent Application No. 6-32053).

It is therefore an object of the present invention to provide a verbes sertes, reversible, thermosensitive recording material provide the most, if not all, benefits similar materials used, while many eliminates the aforementioned disadvantages.

Another object of the present invention is to provide a rever sibles to provide heat-sensitive recording material improved erasability and improved performance Image contrast even with a reduced heating time of a heat medruckkopfes has to the more and more increasing data processing speed to match. In addition will the reversible, heat-sensitive recording material before but without a large-scale and expensive system, but has Nevertheless, with repeated use, a satisfactory durability ness.

To achieve the previous and other goals, the Invention according to a first aspect, a reversible, heat temp sensitive recording medium, which is a heat-sensitive Layer having provided on a supporting substrate is, wherein the heat-sensitive layer, the transparency or the color changes reversibly with temperature, and the reversible, heat-sensitive recording medium a change the delayed initial transparency temperature of at most 5 ° C and more preferably at most 2 ° C.  

According to an alternative or further embodiment is a Reversible, heat-sensitive recording medium provided, this is a change in the delayed transparency start temperature of not more than 5 ° C, or a rate of change of Transparency temperature width of at least 90%.

In another embodiment, a reversible, wärmeemp sensitive recording medium provided that a heat temp has sensitive layer on a supporting substrate is provided and as the main components of a matrix resin and comprises an organic material of low molecular weight, which is dispersed in the matrix resin, the heat-sensitive Layer the transparency or hue reversible with the Temperature changes wherein the matrix resin is either a crosslinked Mixture of a hydroxyl-containing, thermoplastic resin, a linear isocyanate compound and a cycli isocyanate compound or a crosslinked urethane resin Polycarbonate-based. In addition, the cyclic iso cyanate compound has a molecular weight of at least 250, bezo to an isocyanate group. Furthermore, the matrix resin has a Glass transition temperature of at least 40 ° C and at most 120 ° C.

In yet another embodiment, the organic Ma low molecular weight material dispersed in the matrix resin Pergiert is a mixture of at least one organic Ma low melting point, low molecular weight material weight and at least one organic material with high Melting point and low molecular weight, wherein the Difference of the melting points between the organic material with low melting point and low molecular weight and the organic material with high melting point and low Molecular weight is at least 30 ° C. In addition, this indicates organic low molecular weight material a mixture from at least one linear hydrocarbon-containing Compound having a melting point of at least 130 ° C, available from  an amide, urea and sulfonyl bond and a carboxyl has at least one or one, and at least one linear hydrocarbon-containing compound, with a melting point which is at least 30 ° C higher than that linear hydrocarbon-containing compound.

In another embodiment, a reversible, wärmeemp sensitive recording medium a top transparency temperature temperature of at least 125 ° C, a difference between the highest Transparency temperature and the lowest white-opaque temperature of not more than 20 ° C, and a transparency temperature width of at least 30 ° C.

In another embodiment, a layer is also made of an adhesive or pressure sensitive adhesive on the side of the supporting substrate against the reversible, heat sensitive provided for a reversible, form heat-sensitive recording label. additionally For example, the supporting substrate may be in the manner of a card.

In another embodiment, the supporting substrate Further, an information recording section, which of a magnetic recording layer, an integrated Circuit and an optical memory at least one or has one, and a printed display section can even if on the reversible thermosensitive recording medium be provided.

In another embodiment, the supporting substrate a surface of a disk cartridge in which a rewritable storage disk or disk unterge was brought, a rewritable or just once described bare disk or disk or a magnetic tape cassette.

In another aspect, the invention provides a disk ten- or disk cartridge, which is capable of at least one  To display part of the information that is in a re writable information storage disk or disk ge stores and the rewritable information Memory disk or disk and a reversible, heat temp sensitive recording label, the at least vorgese one of the surfaces of the diskette or disk cartridge hen is the rewritable information store Diskette or plate is housed.

In another embodiment, a rewritable Information storage disk or disk provided in the is able to display at least part of the information in the rewritable information storage diskette or disk are stored, with the rewritable In formation memory disk or disk and a reversible, heat-sensitive recording label attached to at least one of the surfaces of rewriteable information storage cherplatte or -diskette is provided.

In yet another embodiment, a magnetic tape is kas provided that is capable of providing at least part of To display information stored on the magnetic tape are, with the magnetic tape cassette and a reversible, heat sensitive record label attached to at least one Surface of the magnetic tape cassette is provided, in which the Mag netband is recorded.

In still another aspect, the invention provides a method for forming and erasing an image on a reversible, thermally sensitive recording medium. The reversible thermosensitive recording medium may be selected from the group consisting of:
a reversible thermosensitive recording medium having a thermosensitive layer provided on a supporting substrate, the reversible thermosensitive recording medium having a change in retarded transparency of at least 5 ° C, and wherein the reversible thermosensitive recording medium is further comprised of a reversible thermosensitive recording medium; heat-sensitive recording label, which further comprises a layer of an adhesive or pressure-sensitive adhesive on the side of the supporting substrate facing the heat-sensitive recording layer;
the reversible thermosensitive recording medium is further provided on at least one of the surfaces of a rewritable information storage disk;
the reversible thermosensitive recording medium is further provided on at least one of the surfaces of a disk cartridge in which a rewritable information storage disk is accommodated; and
the reversible thermosensitive recording medium is further provided on at least one of the surfaces of a magnetic tape cassette, wherein:
the process is carried out by heating.

In another embodiment, the method of molding and erasing an image even with either a thermal pressure head or a ceramic heater. to In addition, the process with a thermal print head so by that it matches the overwriting method true, in which the writing of new pictures imagewise immed bar after deleting the old pictures with variable heating performance for each picture.

Preferred embodiments of the invention are hereafter described with reference to the drawings, in which:  

Fig. 1 is a graph showing the change in the reflection density with the heating energy supply to a heat-sensitive recording medium according to the present invention;

Fig. 2 is a graph showing the change in transparency with the temperature of a heat-sensitive recording medium according to the present invention;

Fig. 3 is a graph illustrating the change in the reflection density with the temperature and represents various characteristic parameters of a heat-sensitive Aufzeich recording medium according to the present invention;

Fig. 4 illustrates a thermosensitive recording label provided on a floppy disk cartridge;

Fig. 5 illustrates a thermosensitive recording label provided on a rewritable compact disc;

Fig. 6 illustrates the layered structure of an optical information storage medium according to an embodiment;

Fig. 7 illustrates a thermosensitive recording label provided on a video cassette;

Figs. 8A to 8C illustrate a variety of structures of heat-sensitive recording media according to the present invention;

9A and 9B, another embodiment of a wärmeemp-sensitive recording medium which is formed of a type of card.

Fig. 10A is yet another embodiment of a thermosensitive recording medium formed of a type of card and further provided with a concave portion for mounting a wafer substrate thereon;

Fig. 10B shows the wafer of Fig. 10A, on which integrated circuits are fabricated and electrical contact terminals are connected thereto;

Fig. 11A shows a schematic representation of the integrated scarf lines of Fig. 10B;

Fig. 11B contains a table representing memory locations in the access memory or RAM of Fig. 11A:

Figs. 12A and 12B illustrate recording apparatuses for the reversible heat-sensitive recording medium of the present invention;

Fig. 13 is a graph showing the change of the reflection density with the temperature and illustrating various characteristic parameters of the thermosensitive recording medium according to the present invention;

Fig. 14 is a graph showing the change of the reflection density with the temperature in the heat-sensitive recording medium obtained in Example 1;

Fig. 15 is a graph showing the change of the reflection density with the temperature in the heat-sensitive recording medium obtained in Example 4;

Fig. 16 is a graph showing the change of the reflection density with the temperature in the heat-sensitive recording medium obtained in Example 5;

Fig. 17 is a graph showing the change of reflection density with the temperature in the heat-sensitive recording medium obtained in Example 6;

Fig. 18 is a graph showing the change of the reflection density with the temperature in the heat-sensitive recording medium obtained in Example 7;

Fig. 19 is a graph showing the change of the reflection density with the temperature in the heat-sensitive recording medium obtained in Example 8;

Fig. 20 is a graph showing the change of the reflection density with the temperature of the thermosensitive recording medium obtained in Example 9:

Fig. 21 is a graph showing the change of the reflection density with the heat-sensitive recording medium temperature obtained in Example 10;

Fig. 22 is a graph showing the change of the reflection density with the temperature in the heat-sensitive recording medium obtained in Comparative Example 1;

Fig. 23 is a graph showing the change of the reflection density with the temperature in the heat-sensitive recording medium obtained in Comparative Example 2; and

Fig. 24 is a graph showing the change of the reflection density with the temperature in the heat-sensitive recording medium obtained in Comparative Example 3.

In the following, detailed description will be specific Embodiments of the invention described in Application cases of image recording are particularly useful. It will However, it should be noted that the invention is not limited to these Embodiments is limited. For example, it will be apparent emphasized that the recording media and methods of the invention adaptable to any form of reversible recording media. to These versions are the expert after reading the following description.  

A reversible thermosensitive recording medium of present invention has a layer of heat sensitive chem recording material that is capable of with the temperature a change of transparency or color to show. In the present invention, the attention becomes first of all to the first amendment, in which the medium shows a change in transparency (i.e., between transparent and white-opaque states).

One takes following mechanism of this change of the reversi blen, thermosensitive recording material between the Transparency and the white-opaque state.

The mechanism is based on the facts that (1) in the transpa penten state particles of organic material with low Molecules which are dispersed in the matrix resin, in Close contact with the matrix resin, without any room between them and also without any space in the particles, so that from the one side incident light to the other side without noticeable scattering can be transmitted, so that Transpa (2) in the white-opaque state the par low molecular weight organic material now formed of numerous small crystals, and that even small spaces at the interface between the klei NEN crystals and the matrix resin are formed so that of the one side incident light at the small spaces reflected or scattered, so that a white-opaque state will be shown.

Reference is now made to Fig. 2 which shows the change of transparency by heating; a heat-sensitive layer comprising a matrix resin and a low molecular weight organic material is in a white-opaque state at ambient temperature T ₀ or below.

Upon heating, the heat-sensitive layer gradually begins to become transparent at a temperature T ₁ and becomes completely transparent in a temperature range T ₂ to T ₃ . When this layer is cooled to ambient temperature below T ₀ , the layer remains transparent.

The above phenomenon can be explained as follows: when the temperature is raised to T ₁ , the resin begins to soften. As this softening proceeds, the resin fills the space between the resin and the low molecular weight organic material particles as well as between adjacent particles, thereby increasing the transparency. At a temperature in the range of T ₂ to T ₃ , the low-molecular-weight organic material partly melts, so that the remaining space is filled thereby, whereby the layer becomes transparent. When the layer is cooled as mentioned above, the organic material of low molecular weight crystallizes at a relatively high temperature because of the presence of nuclei. In this case, since the resin is still in a softened state, the resin can follow the volume change caused by the crystallization of the low molecular weight organic material, so that no gap is formed. That is, the layer remains transparent due to the cooling.

If, on the other hand, it is heated to a temperature T ₄ or above, then the layer between the maximum transparency and the opaque state becomes translucent. Subsequently, when the temperature is lowered, the layer returns to the white initial state, not the transparent state.

This can be explained as follows: at a temperature of T ₄ and above, the low molecular weight material completely melts. When the temperature is then lowered, the low molecular weight material is overcooled and crystallized at a temperature only slightly higher than T ₀ . In this case, the matrix resin which has already started to solidify and which is no longer in a softened state can not follow the volume change caused by the crystallization of the low-molecular-weight organic material, resulting in the formation of Intermediate and thereby the opaque state leads, as mentioned earlier.

It may be noted that although the transparency versus temperature curve in Fig. 1 is a typical example, the transparency properties will change as the materials used are exchanged.

At this point, two parameters are defined, namely the Change the initial transparency temperature and the rate of Change the transparency temperature width.

First, when gradually heating a white-opaque sample, the temperature is measured at which the white-opaque sample becomes transparent. More specifically, the heating is performed by using a thermal gradient tester (HG-100, TOYO SEIKI Co.) for a heating period of 0.1 second with the heater block of the tester in contact with a pressure of 1.0 kg / cm ² with the sample so that the temperature of the sample rises from a low temperature, at which the white-opaque state of the sample does not change, in equal steps of 2 ° C to a temperature at which the transparency is reached , Subsequently, the temperature is increased, like the same from 2 ° C to 5 ° C, from a low temperature at which the transparency of the sample is reached to a temperature at which a white-opaque state is sufficiently reached.

To prevent the sample of the medium during the heating glue on the heating block, a thin film made of poly imid or polyamide is composed and which has a thickness of  10 microns or less along with sufficient heat has to be arranged in between.

After heating in the manner described above, the Sample cooled to room temperature and measurements of optical Reflection density or blackening at respective points below pulled, which were heated to the respective temperatures, and although using a MacBeth Reflection Densitometer RD- 914. The values of the measured density are plotted, with the selected temperature of the heat gradient tester as Ab szisse and the reflection density as ordinate.

When the backing is transparent, underneath the reversible layer, the values of the reflection density for example, with a sheet or a layer of aluminum measured at the back of the Aufzeich layer is applied, so that the sheet or the layer either absorb light or sor for regular reflection can.

After applying density values at the respective temperatures, the diagram is completed by connecting pairs of juxtaposed plotted dots with straight lines. The data curve in the diagram is generally obtained in a trapezoidal shape as shown in FIG .

The observed values are influenced by several parameters flows, such as the total thickness of the recording layer together with the substrate and the type of material used. Since there is no significant effect of the thickness for the area the thickness of the recording layer of at most about 300 microns kron can be reproducible for this area Results are obtained.

On the other hand, if the thickness exceeds the above range, then the values of density are affected by the thickness, and too  Reliable values can only be determined after a balance of the effects kung thickness can be obtained. This is done by either remove backward portions of the recording layer, to reduce the thickness to at most about 300 microns, or by converting the observed values in relation to the thickness net. In addition, if the recording layer in the first place is composed of polymeric materials, no results significant impact; if, on the other hand, the layer is first Line composed of metals, becomes a calculation for conversion similar to the above-mentioned necessary.

Characteristic parameters, such as the dynamic initial transpa temperature and the dynamic end-transparency temperature, are obtained from the thus prepared diagram.

Referring to Fig. 13; the maximum reflection density is obtained from the plot. A straight line representing y = 0.7 × (the maximum reflection density) is drawn below. In the area above the straight line drawn in this way, several data points are selected, in order to thereby preferably find 5 to 20 points within this area. A number of points less than the above number may cause some ambiguity in the results obtained by the following calculations. If half of a number is found which is smaller than the above range, then it is necessary to increase the number of points by reducing the heating time interval during the aforementioned heating treatment using the thermal gradient tester.

After excluding points of both higher and lower density among the points so selected, density values for the remaining points are obtained. This is followed by _averaging these values, and thereby to arrive at a mean transparency _density (D _tavd ). The ratio of the number of the above-mentioned excluded points to the entire selected points is preferably 10% to 30%, and more preferably 15% to 25%. By excluding the higher and lower density dots as above, reliable transparency density values can be obtained.

Next, the lowest dynamic _{density of} transparency (D _tld ) is calculated by the following equation:

D _tld = D _tavd - 0.2 × (D _tavd - D _m ) (1)

where D _{m is} the maximum opaque density which is obtained among the density values when the white-opaque state is confirmed by vision. Therefore, the lowest, dynamic transparency density (D _tld ) is obtained as the density above which the sample is seen to be nearly transparent by sight.

In addition, after drawing a straight line representing y = D _tld , the temperatures at the intersection between the straight line thus drawn and the data curve are obtained. Among the temperatures, the lower temperature is defined as the initial dynamic _transient temperature (T _tsd ), while the higher temperature is defined as the dynamic final _transparency temperature (T _ted ). The transparency temperature _width (dT _wd ) is given below by the following equation:

dT _wd = T _ted - T _tsd (2).

For example, white opaque images may be formed by pressing the heat-sensitive medium against a hot plate for about 10 seconds, heated to a temperature high enough to achieve the white-opaque state, and then allowed to cool room temperature. When the thus-prepared white-opaque images are heat-treated with the thermal gradient tester and subjected to optical density measurements within several tens of minutes, the value of T _tsd thus obtained is a dynamic initial transparent temperature (T _tsd ). immediately after image formation, and similarly, the obtained value of dT _{wd is} the dynamic transparency temperature _width (dT _wd ) immediately after image formation.

Next, two more parameters will be described, such as dynamic start transparency temperature and dynamic Transparency temperature width, both after a long time tion.

In this case, white-opaque images are heat-sensitive Medium stored at 35 ° C for one week. The heat-sensitive Medium with the white-opaque images is below sim conditions as in the abovementioned measurements of Initial transparency temperature is warmed, with heating by Increase the temperature in equal steps and under Benut tion of the heat gradient tester is made.

After drawing a straight line representing y = D _tld , the temperatures at the intersection between the drawn line and the data curve are obtained. At these temperatures, the lower temperature is defined as the initial dynamic trans-face temperature after prolonged storage (T _tsd '), while the upper temperature is taken as the dynamic end-transparency temperature after prolonged storage (T _ted '). The transparency temperature _width after prolonged storage (dT _wd ') is then given by the following equation:

dT _wd '= T _ted ' _{-T tsd} (3).

Therefore, the T _tsd 'thus obtained is the initial dynamic transmittance temperature (T _tsd ) after prolonged storage, and dT _Wd ' is the transparency temperature width (dT _Wd ) after prolonged storage. In the following, a time-delayed or delayed change of the initial transparent temperature (dT _ts ) and the rate of change of the transparency temperature width (dT _w ) are indicated by the following equations:

dT _ts = T _tsd '- T _tsd (4)

dT _W = (dT _Wd '/ dT _Wd ) × 100 (5).

The delayed change of the initial transparent temperature (dT _ts ) is preferably at most 5 ° C, and more preferably at most 2 ° C. A delayed change larger than the above range causes difficulty in deleting images. Also, this change (dT _tS ) is preferably at most -5 ° C, and more preferably at -2 ° C. A delay change even smaller than the above range causes the difficulty that images are easily erased during storage at high temperatures.

The delayed change in the transparency temperature width (dT _W ) is preferably 90%, and more preferably 95%, as required. The change, which is less than the above range, causes difficulty in canceling a picture in a relatively short heat-up time using a thermal print head. This change (dT _W ) is also at most 120%. preferably at most 115% and most preferably at most 105%. A change larger than the above range causes a problem such as a changing density of images formed using a thermal print head.

The aforementioned two parameters, the delayed change of the initial transparent temperature (dT _ts ) and the rate of change of the transparency temperature width (dT _W ,) can also be considered as the parameters which, from a different point of view, reflect the change in material properties of the matrix resin illustrate the heat-sensitive layers.

Namely, as described earlier, the change in erasability is attributed to the change of the glass transition temperatures of the matrix resin. Although glass transition temperatures are generally measured with a measuring device such as a DSC (differential scanning calorimeter) or a DMS (data management system), it is difficult to obtain reliable results from the measurements with a sample such as a heat-sensitive layer. which is applied to a substrate as a coating, as is often the case. In the present measurements for the reversible recording layer, the temperature T _{1 represents} a glass temperature, which is a temperature that is the initial transparency, as shown in the assignment of transparency to the temperature in FIG. 2.

Therefore, the dynamic initial _transparency temperature (T _tsd ) obtained by the heat treatments using a thermal gradient tester corresponds to the glass transition temperature. Accordingly, the delayed onset transition temperature (dT _ts ) is considered to represent the change in glass transition temperature over time.

In addition, the dynamic end transparency temperature (T _ted ), that is, the temperature at which the transition from the transparent state caused by the heating using the thermal gradient tester to the opaque state, represents the temperature at Molecules with low molecular weight, long chains and high melting point begin to melt. Similarly, the transparency temperature width represents the temperature width from the glass temperature of the resin to the melting point of the low molecular weight, long chain and high melting point molecules. Further, the rate of change in the transparency temperature width (dT _W ) represents the change in the temperature width of the Glass transition temperature up to the melting point of the molecules of low molecular weight, long chains and high melting point.

One of the points to achieve that reversible, heat sensitive recording medium improved capabilities of the above, delayed onset transparency temperature and the Rate of change of the transparency temperature width is it inter alia, that a flexible structure of the molecule in the resin matrix is inserted.  

This can be done especially by either a suitable combination of the resin material and a Vernet with a flexible structure or a resin with a flexible structure chooses. By being such a flexible one Structure introduces into the resin matrix, different We can achieved, such as preventing aggregation of molecules in a longer storage time and decreasing the enthalpy relaxation in the molecular system. As a result can reduce the rate of change of glass transition Temperature and the change of the above-mentioned parameters in Lau be prevented over time.

In addition, the durability of repeated use there be improved by making the matrix resin in the reversible Forms a recording medium by a crosslinking reaction, and although using a thermoplastic resin containing a having functional group capable of reacting with the ver to react.

As for the method of crosslinking the resin used in the reversible, heat-sensitive layer is included, so can Heating, ultraviolet (UV) irradiation or electrons beam (EB) irradiation are used. Since the electric irradiation a relatively expensive Einrich tion is the heating method or the UV irradiation preferred. The heating process is even more to prefer, because this method is generally less used expensive equipment, and because the Vernetzungsreakti due to heat even at relatively low temperature can progress, namely during the longer storage for a period of, for example, 1 week or 1 month.

Examples of such a desirable combination of resin material Al and crosslinkers typically but not necessarily include restricting (1) a thermoplastic resin having a hydro xyl group and an isocyanate compound, and (2) a thermopla  Stical resin with an acryloyl or methacryloyl group and an acrylic or methacrylic monomer.

In the first combination of a containing a hydroxyl group the thermoplastic resin and an isocyanate compound the mixture of linear and cyclic isocyanate compounds preferably be used as isocyanate compound.

If only linear isocyanate compounds are used the resulting crosslinked resin has a flexible structure, and the erasability is improved. Too flexible structure ver However, it causes difficulties, such as the loss of grip in the repeated use and the heat resistance ge shaped pictures.

If, however, only cyclic isocyanate compounds used who then, the resulting, crosslinked resin has a rather star re structure. Although in this case the durability is in again brought use and the heat resistance of shaped pictures improved, it has been found that the erasability has decreased. By using a mixture of linear and cyclic isocyanate compounds can therefore delete the improved durability, durability and heat resistance at the same time become.

The weight ratio of linear isocyanate compound to cyc isocyanate compound is preferably 90:10 to 10:90, more preferably 90:10 to 30:70, and most preferably 80:20 to 30: 70. With increasing the linear isocyanate compound can Erasability and maximum extinction gradient increase to thereby to lead to an improvement in image contrast.

The linear isocyanate compound used in the present invention can be used either by the reaction of a li near isocyanate compound containing a hydroxy group such as Triol, directly with an aliphatic isocyanate such as hexamethylene diisocyanate or by the reaction of these Ver  in the presence of at least one of ethylene oxide or Be obtained propylene oxide.

The molecular weight of the linear isocyanate compound is preferably at least 500, more preferably at least 700 and on most preferably at least 1000. The above molecular weight is also preferably at most 5000, more preferably at most 4000, and most preferably at most 3000.

Too low molecular weight of the linear isocyanate compound This reduces the flexibility of networked devices Resin structure, whereby the erasability is reduced while too high a molecular weight of which the reduction of the Ver degree of network due to the difficulty of movement of the mole causes it to reduce in the shelf leads.

The molecular weight, based on an isocyanate group, is at least 250, preferably at least 300 and most before gives at least 400. The molecular weight is also ahead at most 2000, more preferably at most 1500 and most of me most preferably 1000.

Too low molecular weight, to an above-mentioned Isocy anatgruppe, causes the decrease in flexibility the crosslinked resin structure and thereby reduces the extinguishing while an excessively high molecular weight thereof is the Ver Reduction in the degree of crosslinking due to the difficulty of Causing movement of the molecules and thereby reducing them the durability leads.

Specific examples of the linear isocyanate compound include, but are not limited to, the following:

OCN-R'-O-CONH-R-NHCO-R "-NCO (II)

(R, R ', R ": alkylene, - (CH ₂ CH ₃ O) _n - or - (CH ₂ CH ₃ CH ₂ -O) _m -; m, n: 1-10).

The cyclic isocyanate compounds disclosed herein Isocyanate compounds which contain a benzene ring or an iso cyanurate ring. Of these compounds, those which have an isocyanurate ring, preferably used because of their ability to prevent yellowing. It is for this Isocyanate compounds are also preferred, in these a linear Structure such as an alkylene chain in addition to the ring structure contribute.

The molecular weight of the cyclic isocyanate compound is preferably at least 100, more preferably at least 200 and most preferably at least 300. The above molecular weight is also preferably at most 1000 and more preferred at most 700.

Too low a molecular weight of the cyclic isocyanate ver Bond causes too low crosslinking due to evaporation the compound when heated during the steps of Be stratification process and thereby leads to a decrease in the durability. In contrast, leads to a high molecular weight this also for reducing the durability, namely due to insufficient formation of the rigid molecular structure.

Specific examples of the cyclic isocyanate compound include, but are not limited to, the following:

The mixture of linear and cyclic isocyanate compounds can be done either by mixing the aforementioned compounds or as a commercially available mixture. at games of such a mixture include in non-limiting Way Coronate 2298-90T (from Nippon Polyurethane Industry Co.) with a ratio of compound (I) to compound (II) of 3.7.

The glass transition temperature of the above-mentioned thermoplastic Resin having hydroxyl groups and together with a Isocyanate compound is used is preferably Minde at least 40 ° C, more preferably at least 50 ° C and most preferably at least 60 ° C. The glass transition temperature is also preferably at most 120 ° C and more preferably at most 100 ° C. Too low a glass transition temperature of the thermopla Stical resin causes a decrease in the heat resistance speed of the formed images, while too high a temperature this causes a reduced erasability.

Illustrative examples of the thermoplastic resin used in the usable in the present invention include polyvinyl chloride resins, polycarbonate resins, polyurethane resins and copolymers here from.

Specific examples of the thermoplastic resin include Vi vinyl chloride-vinyl acetate-vinyl alcohol copolymers, vinyl chloride Acrylate-vinyl alcohol copolymers and vinyl chloride-vinyl acetate  Hydroxyalkyl acrylate copolymers. Further, vinyl chloride ze, which is a sulfonic acid group in addition to the hydroxyl group also be used. Special materials, which can be suitably used in the invention comprises MR-110, MR-104, MR-112 and MR-113, each from Nippon Zeon CO are commercially available. Especially the resins that a highly polar functional group such as a sulfonic group are preferred because of your ability to use the Improve image contrast.

The amount by weight of the isocyanate compound, 100 parts by weight is at least 1 (one), more preferably at least 3. The amount is also preferred at most 50, and more preferably at most 40.

Too small an amount of the isocyanate compound causes a Decrease in durability, while too large an amount caused by transparency.

The equivalent of the isocyanate group in the isocyanate compound is based on the hydroxyl group in the resin, preferably min at least 0.05, more preferably at least 0.1 and most be preferably 0.2. The equivalent is also preferably at most 2 and more preferably at most 1 (one).

Too small an equivalent of the isocyanate group causes the Decrease in durability, while too large an equivalent of the Decrease in transparency caused.

As the crosslinking methods disclosed herein and described in U.S. Pat a combination of a thermoplastic resin containing a Acryloyl or methacryloyl group, and having a Acrylic or methacrylic monomer can be carried out Among other things, two methods are used here.

One goes through a cross-linking reaction between one Acryloyl or methacryloyl group in the resin and the monomer, un  supported by radicals that are produced by heating with organic Peroxides are produced, which are mixed therein. The on The latter proceeds via a crosslinking reaction that supports is caused by radicals caused by irradiation with ultraviolet Be generated, herein polymerization initiators instead of the above-mentioned radicals by heating attached are.

Of these procedures, the first is because of the simpler to griffs over the second preferable by the Vernet in the first reaction by heating using organi shear peroxides can be achieved without a fairly expensive Facility as needed in the second.

The examples of acrylic or methacrylic monomers used for the present invention include functional Mo monomers and oligomers, which are generally used to form resins used with ultraviolet rays or with Harden electron beams. Of these connections will be those which have a more flexible structure, preferably used, for example, aliphatic compounds and aromatic Ver bonds associated with the linear chain structure. In Similarly, mono- and bifunctional monomers against preferred over multifunctional monomers (these are three or higher functional monomers).

Specific examples of these monomers include the following. but are not limited to these:

Monofunctional monomers

Methacrylic acid (MAA)
Hydroxyethyl methacrylate (HEMA)
Hydroxypropyl methacrylate (HPMA)
Dimethylaminoethyl methacrylate (DMMA)
Chloride salt of dimethylaminoethyl methacrylate (DMCMA)
Diethylaminoethyl methacrylate (DEMA)
Glycidyl methacrylate (GMA)
Tetrahydrofurfuryl methacrylate (THFMA)
Allyl methacrylate (AMA)
Ethylene glycol dimethacrylate (EDMA)
Triethylene glycol dimethacrylate (3EDMA)
Tetraethylene glycol dimethacrylate (4EDMA)
1,3-Butylene glycol dimethacrylate (BDMA)
1,6-hexanediol dimethacrylate (HXMA)
Trimethylolpropane trimethacrylate (TMPMA)
2-ethoxyethyl methacrylate (ETMA)
2-ethylhexyl acrylate
phenoxyethyl
2-ethoxyethyl
2-ethoxyethoxyethyl
2-hydroxyethyl acrylate
2-hydroxypropyl acrylate
dicyclopentenyloxyethyl
N-vinylpyrrolidone
vinyl acetate

Bifunctional monomers

1,4-butanediol
1,6-hexanediol diacrylate
1,9-nonanediol diacrylate
neopentylglycol
tetraethylene
tripropylene
Polypropylene glycol diacrylate (adduct of bisphenol A with ethylene oxide) diacrylate
Glycerol methacrylate acrylate (adduct of neopentyl glycol with 2 moles of propylene oxide) diacrylate
diethylene
Polypropylene glycol (400) diacrylate
Neopentylglykolhydroxypivalatdiacrylat
2,2-bis (4-Acryloxydiethyloxyphenyl) propane
Neopentyl glycol adipate diacrylate (adduct of neopentyl glycol hydroxypivalate with ε-caprolactan) diacrylate
2- (2-hydroxy-1,1-dimethylethyl) -5-hydroxymethyl-5-ethyl-1,3-dioxane diacrylate
Tricyclodecanedimethylol diacrylate (adduct of tricyclodecanedimethylol with ε-caprolactone) diacrylate
1,6-Hexamethylendiglycidyletherdiacrylat
trimethylolpropane
Pentaerythritol triacrylate (adduct of glycerol with polyethylene oxide) triacrylate
Trisacryloyloxyethylphosphat
Pentaerythritol tetraacrylate (adduct of trimethylolpropane with 3 moles of propylene oxide) triacrylate
glycerol propoxy triacrylate
Dipentaerythritol polyacrylate (adduct of dipentaerythritol with ε-caprolactone) - polyacrylate
Dipentaerythritolpropionate triacrylate (hydroxypivalaldehyde modified dimethylolpropyne) triacrylate
Dipentaerythritolpropionattetraacrylat
dimethylolpropane
Dipentaerythritolpropionatpentaacrylat
Dipentaerythritol hexaacrylate (DPHA) adduct of dipentaerythritol hexaacrylate with ε-caprolactone.

The amount of acrylic or methacrylic monomer that becomes an art resin is preferably at least 1 (one) Ge weight part, more preferably at least 3 parts by weight and am most preferably 5 parts by weight per 100 parts by weight of the Resin. The amount thereof is also preferably at most 70 Parts by weight, and more preferably at most 50 parts by weight.  

Too little amount of monomer causes the difficulty reducing durability in repeated use, elect an excessive amount of this will worsen the Transparency causes.

In addition, the equivalent of acrylic or methacrylic group, based on acryloyl or methacryloyl preferably minde at least 0.02 and more preferably at least 0.05. Additionally be the equivalent preferably carries at most 2, more preferably at most 1 (one), and most preferably 0.8.

Too little equivalent of the monomer causes the difficulty while reducing the resistance of the inverting ability to much equivalent, a deterioration in transparency gently.

The glass transition temperature of the thermoplastic resin with an acryloyl or methacryloyl group is preferably min at least 40 ° C, more preferably at least 50 ° C and most preferably at least 60 ° C. In addition, the glass is over transition temperature preferably at most 120 ° C and more preferably at most 100 ° C.

Too low a glass transition temperature of the thermoplastic Resin causes the difficulty of reducing the heat Resistance of shaped pictures, while too high a glass Transition temperature a reduction in erasability verur gently.

Illustrative examples of the thermoplastic resin with an acryloyl or methacryloyl group include polyvinylchloro resins, polycarbonate resins, polyurethane resins and copolymers but not limited to these.

Specific compounds of a thermoplastic resin with a Acryloyl or methacryloyl be, for example, from Graft copolymers exemplified by the reaction of the  Hydroxyl group of the aforementioned thermoplastic resin, the has a hydroxyl group, with the isocyanate group of Iso cyanate compound can be obtained, which is an acryloyl or methacryloyl group.

Here disclosed examples of a thermoplastic resin which having an acryloyl or methacryloyl group include Vi vinyl chloride-vinyl acetate-vinyl alcohol copolymers, vinyl chloride Acrylate-vinyl alcohol copolymers and vinyl chloride-vinyl acetate Hydroxyalkyl acrylate copolymers.

In addition, examples of the isocyanate compound including a Methacryloyl or acryloyl group, methacryloyloxy ethylisocyanate, but are not limited thereto.

Examples of the organic peroxides suitably described in used in the present invention include ketone oxide, peroxyketal, hydroperoxide, dialkyl peroxide, dialkylper oxide, peroxyester and peroxydicarbonate.

The initiator for the photopolymerization is among those chosen, which generally when curing resins with UV Bestrah ment, and these initiators are used individually or used as a mixture of two or more. The amount the initiators for the photopolymerization added is, is preferably 0.005 to 1.0 parts by weight, more preferably 0.01 to 0.5 parts by weight per part by weight of Ver netzungsmittels.

In addition, a photopolymerization accelerator such as aro added, tertiary amines or aliphatic amines become. These accelerators are used singly or as a mixture of used two or more. The amount of photopolymerisati Onsbeschleuniger is preferably 0.1 to 5 parts by weight and more preferably 0.3 to 3 parts by weight, per part by weight of Photopolymerization.  

Illustrative examples of the aforementioned resin suitable for use in the present invention and having a flexible structure include, but are not limited to, polycarbonate-based urethane resins. Specific examples of the base polycarbonate include, but are not limited to, the following:

(R, R ': methylene or aromatic group: m = 1 ~ 10).

As urethane resins based on polycarbonate also NIPPOLAN 3151 available from Nippon Polyurethane Industry Co., they but are not limited to this.

Another point to get the reversible, heat sensitive Chen recording medium with improved capabilities of Erasability and in the maximum erasing gradient is the Verwen a variety of compounds with different Melting points in combination.

Among the compounds, the melting point difference is between the connections with the lowest and the highest most melting point at least 30 ° C, preferably at least 40 ° C, more preferably at least 50 ° C, and most preferably min at least 60 ° C. The bigger the difference, the bigger the Ver improvement of erasability.

It is preferred that the properties of the reversible, heat sensitive recording medium in the present invention satisfy the following three conditions: (1) the highest Transparency temperature is at least 125 ° C, (2) the difference between the highest transparency temperature and the lowest white-opaque temperature is at most 20 ° C and (3) the Transparency temperature range is at least 30 ° C.  

In the present invention, characteristic temperatures for the reversible thermosensitive recording medium can be determined in the following manner, such as the highest trans-parency (T _tu ), the lowest white-opaque temperature (T _s1 ), the difference between the uppermost transparency temperature, and the lowest white-opaque temperature (T _ts ), the initial transparency temperature (T _ta ) and the transparency temperature range (ΔT _W ).

First, a sample of a white-opaque, reversible, heat-sensitive recording medium prepared. An ent neither transparent nor pre-white-opaque piece can can be used after going through the white-opaque state Heat has reached, for example, against a hot plate pushes. To find out if the previously chosen Heating temperature is high enough to the white-opaque state reach the specimen of a second heating zugekom For example, the temperature may be higher by 10 ° C is.

If, after the second heating, the same degree of white-opaque condition has been noted that the previous temperature was high enough to make it white to reach opaque state. Otherwise, the previous Tempe not high enough to achieve the white-opaque state. Therefore, if after the second heating a higher degree of white-opaque condition is found, may be a second warming be used at a slightly higher temperature. This procedure can be repeated successively until he knows opaque state is reached.

The thus prepared, white-opaque sample of the reversible, would be meempfindlichen recording medium is hereinafter the Er heating to different temperatures subjected to the Find out transparency temperatures.  

The heating is performed with the heat gradient tester (HG-100 YO SEIKI Co.). This tester is with five heating equipped blocks, each of which is individually tailored to an un different temperature, a different heating period and a different heating pressure can be controlled so that it is possible to use this tester, at the same time five points on the sample to five respective Tem to warm up temperatures.

Specifically, the heating is carried out for 1 second in contact with the heating block under a pressure of 2.5 kg / cm ² pressure so that the temperature is increased in equal steps of 2 ° C to 5 ° C from a low temperature, in which the transparency of the sample does not change, to a temperature at which the white-opaque state is reached with certainty. In order to prevent the sample of the medium from adhering to the heating block during heating, a thin film composed of polyimide or polyamide and having a thickness of 10 microns or less with satisfactory heat resistance may be interposed therebetween.

After heating in the manner described above, the sample is cooled to room temperature and subjected to measurements of optical reflectance densities at locations heated to respective temperatures using a MacBeth reflection densitometer RD-914. The measured values are recorded as shown in Fig. 3, with the selected temperature of the thermal gradient tester as the abscissa and the reflection density as ordinate.

When the carrier is under the reversible recording layer is transparent, density values can be with a bow ge measure that at the back of the recording layer like this is attached, that the sheet can either absorb light or ensures regular reflection.  

After the order of the density values at the respective tempera ren the order is completed by connecting pairs be neighbar, applied points by straight lines. The data curve in the order is generally obtained in the trapezoidal form, as shown in Fig. 2.

The observed data are influenced by several parameters such as the total thickness of the recording layer together with the substrate and the type of used Material. As for the range of the recording layer thickness of at most about 300 microns no noticeable effect of thickness observed, reproducible for this area results are obtained.

If, however, the thickness exceeds the above value, you can values are affected by the thickness, and reliable Results can only be achieved when the off Effect of the thickness corrected. This is done either by led that one backward sections of the recording layer to increase the thickness to at most about 300 microns decrease or that one can observe the observed values in proportion converted to the thickness. When the recording layer is first Line composed of polymer materials occurs except there is no noticeable effect on the other hand is a conversion tion similar to the one mentioned above, if the layer composed primarily of metals.

The above-mentioned, characteristic temperatures, like the highest transparency temperature and the lowest white-opaque tem perature, are obtained from the application so prepared.

Reference is made to FIG. 3; the maximum reflection density (D _max ) is taken from the plot first. Then draw a straight line representing y = 0.7 × D _max . A plurality of points are subsequently selected in the region above the straight line 0.7 × D _max , to thereby preferably find 5 to 20 points within this range. A smaller number of points than the above number may cause some ambiguity in the results obtained by the subsequent calculations. Therefore, if it is found that the number is smaller, it is necessary to increase the number of dots by reducing the heating time interval during the above-mentioned heat treatment using the heat gradient tester.

After excluding the same number of higher and lower density points among the points thus selected, density values for the remaining points are obtained. This is followed by averaging these values to thereby arrive at an average of the transparency density (D _tav ). The ratio of the above-mentioned excluded points to the entirety of the selected points is preferably 10% to 30%, and more preferably 15% to 25%. By excluding the dots of higher and lower density, reliable transparency values can be achieved.

Next, the lowest transparency density (D _tm ) is calculated by the following equation:

D _tm = D _tav - 0.2 × (D _max - D _min ) (6)

where D _{min is} the maximum opaque density obtained by averaging the density values of three adjacent points when the difference in density between these three values reaches at most 0.3. Further, the value D _{tm is} approximately equal to the density value above which observation reveals that the recording layer is transparent.

After drawing a straight line representing y = 0.7 × D _tm , temperature readings are obtained at the intersections between the straight line thus drawn and the data curve. The temperatures for the higher and lower readings are regarded as the lowest (T _t1 ) or uppermost (T _tu ) transparency temperature.

The transparency temperature width (ΔT _W ) is obtained by the following equation:

ΔT _W = T _{tu -T t1} (7)

In addition, the top white-opaque density (D _S ) is calculated by the following equation:

D _S - D _min + 0.1 × (D _tav - D _min ) (8).

After drawing a straight line representing y = D _S , the lowest transparency temperature is read as the temperature corresponding to the intersection between the straight line thus drawn and the data curve.

The temperature difference (ΔT _ts ) between the upper transparent temperature and the uppermost opaque white temperature is obtained by the following equation:

ΔT _ts = T _s1 - T _tu (9)

The initial transparency density (D _ts ) is obtained by the following equation:

D _ts = D _min + 0.25 x (D _tav - D _min ) (10).

As shown in FIG. 3, the initial transparent temperature (T _ta ) is then read as the temperature corresponding to the intersection between the straight line corresponding to y = D _ts and the data curve.

In the present invention, the uppermost transparency temperature (T _tu ) is preferably at least 125 ° C. By increasing T _tu , the transparency temperature width (ΔT _W ) can be widened without degrading the durability of the formed images. In addition, the uppermost transparency temperature (T _tu ) is preferably at least 130 ° C, more preferably at least 135 ° C, and most preferably at least 140 ° C.

The higher the temperature T _tu , the more sensitive the recording medium becomes in image recording. The temperature T _tu is also preferably at most 190 ° C. more preferably at most 180 ° C, and most preferably at most 170 ° C. Within this range, the lower the temperature T _tu , the more sensitive the recording medium.

The temperature difference (ΔT _ts ) between the uppermost transparency temperature and the uppermost opaque white temperature is preferably at most 20 ° C. A larger difference ΔT _ts than 20 ° C causes difficulty, requiring a larger amount of energy to form the white-opaque images because the above-mentioned white-opaque temperature is higher than usual, and possibly causing damage to the surface of the recording layer and / or a deteriorated opaque density of the same. The difference ΔT _ts is more preferably at most 20 ° C, and most preferably at most 10 ° C.

The initial transparency temperature (T _ta ) is preferably at most 95 ° C, more preferably at most 90 ° C, and most preferably at most 85 ° C. The temperature T _ta is also preferably at least 70 ° C and more preferably at least 75 ° C. With the decrease of this temperature, the image erasability increases, while the durability increases with the increase of this temperature.

The transparency temperature width (ΔT _W ) is preferably at least 30 ° C. A difference ΔT _W smaller than 30 ° C causes the decrease in erasability. The difference ΔT _W preferably carries at least 40 ° C, more preferably at least 45 ° C, and most preferably at least 50 ° C. The larger the difference, the higher the erasability. The difference also preferably amounts to at most 100 ° C, more preferably at most 90 ° C and most preferably at most 80 ° C. Insbesonde re leads the greater difference in the transparency temperature width to the advantage that constant extinguishing results even at higher processing speed he can be enough during the deletion process. In such cases, the difference ΔT _{W is} preferably at least 60 ° C, more preferably at least 70 ° C.

To be a desirable, reversible, heat sensitive record Forming medium, as mentioned above, is one of Key points the selection of organic materials with low Molecular weight, the ver in the present invention ver are turning. This is in fact caused by the fact that one approves finds a combination of linear hydrocarbons, containing the compounds (A) and (B), wherein the compound (A) has a melting point of at least 130 ° C, and the Compound (B) a fulcrum that is at least 30 ° C higher is as that of the compound (A).

The melting point of the linear hydrocarbon containing the Ver contains bond (A), is preferably at least 135 ° C and more preferably at least 140 ° C. The melting point is also preferably at most 200 ° C, more preferably at most 190 ° C and most preferably at most 170 ° C.

The lower limit of the difference of the melting points between the Compounds (A) and (B) is preferably at least 30 ° C, more preferably at least 40 ° C, and most preferably min at least 50 ° C. The image erasability decreases with the increase of lower limit of the difference of the melting points. Further be the upper limit of the difference preferably does not exceed 100 ° C, more preferably at most 90 ° C and most preferably max at least 80 ° C. The heat sensitivity decreases with the increase of upper limit of the difference too.  

The lower limit of the melting point of the linear, coal the compound containing sulfur (A) is preferably at least 50 ° C, more preferably at least 60 ° C, and most preferably at least 70 ° C. The higher the melting point, the more it is Improved heat resistance.

In addition, these compounds (A) and (B) further, li near hydrocarbon-containing compounds (C) added which have melting points which are at least 10 ° C higher than the compounds (B) and at least 10 ° C. lower than the compounds (A). By adding the Compounds (C), the image contrast can be improved. The Melting point of the linear hydrocarbon-containing Ver Binding (C) is preferably at least 80 ° C, more preferably at least 90 ° C and most preferably at least 100 ° C. The Melting point is also preferably at most 150 ° C, further be preferably at most 140 ° C, and most preferably at most 130 ° C.

These linear, hydrocarbon-containing compounds (A), (B) and (C) can be individually used in the present invention or used in combination. They preferably include a long-chain structure, with preferably 4, more preferred at least 6 and most preferably at least 8 carbon atoms. With the increase of the carbon number, the durable becomes improved with repeated use.

The number of long-chain structures found in the linear Ver may be equal to one or more. in the Moreover, the above carbon number represents the total carbon number of substances in the long chains that are in the linear verbin is included. If two long-chain structures in one linear compound, each of which contains six Koh having the rare earth atoms, then the linear compound as long-chain structure with 12 carbon atoms called.  

If the compounds (A) and (B) are mixed, that is Weight ratio of the compound (A) to the total weight of the or ganic compound of low molecular weight, that is to the weight of the combination of compounds (A) and compound (B), preferably at least 3%, more preferably at least 5% and most preferably at least 10%. The higher the weight ratio, the more the erasability is improved. The Ge weight ratio is also preferably at most 50%, further preferably at most 40%, and most preferably at most 30%. The lower the weight ratio, the higher the trans transparency.

Similarly, the weight ratio of the verbin (B) to the total weight of the organic compounds with low molecular weight preferably at least 30%, more preferably at least 50% and most preferably at least 60%. The lower the weight ratio, the more it is Erasability improved. The weight ratio is also at most 95%, more preferably at most 90% and most preferably at most 85%. The higher the weight ratio, the more higher is the transparency after deletion.

When the linear hydrocarbon-containing compound (C) is added in addition, the weight ratio of Compound (C) to the total weight of the organic compounds low molecular weight preferably at least 3%, more preferably at least 5% and most preferably at least 10%. The higher the weight ratio, the more the trans Parenz improved. The weight ratio is also ahead at most 50%, more preferably at most 40% and most me preferably not more than 30%. The lower the weight behaves The higher the erasability.

The low molecular weight organic material of the re versatile, thermally sensitive recording medium used in the can be suitably used in the present invention preferably, the mixture of at least one kind of linear,  hydrocarbon compound (A), which Has melting points of at least 130 ° C, and that of amide, Urea and Sulfonylbindungen at least one and minde at least one type of carboxy radical comprises at least one type of linear. Hydrocarbon-containing compound (B), which has a melting point that is at least 30 ° C higher as the compound (A).

In the above organic material of low molecular weight the amide, urea and sulfonyl bonds can be used as the highest at least one of the respective bonds or as at least one be contained in these bonds. These bindings can too either at the end or in the middle of the molecular chain his. In addition, any number of carboxy radicals may be included be either at the end of the molecular chain or in one Side chain are attached.

The linear hydrocarbon-containing compound (A) can prefers both an amide bond and a carboxy radical but is not limited thereto. In addition, can preferably, a plurality of at least one of the amide bins tion and the carboxy radicals preferably in the organic material be contained with low molecular weight. It is further more preferred that both the amide bond and the carboxyradi kal are contained herein.

The linear hydrocarbon-containing compound (A) comprising the amide bond and the carboxy radical is expressed by, but not limited to, the following general formula:

HOOC- (CH ₂ ) _n -X- (CH ₂ ) _m -Y- (CH ₂ ) _n -COOH (IV),

where 26 ≧ n ≧ 1, 26 ≧ m ≧ 1, and where X and Y are one of the groups CONH and NHCO, but not both at the same time. The number 2n + m is preferably at least 6, more preferably min at least 8, and most preferably at least 10.  

The linear hydrocarbon-containing compound (A) can prefers both a urea bond and a carboxyra contained dikal. The compound (A) may also preferably both a sulfonyl bond as well as a carboxy radical.

The linear hydrocarbon-containing compound (A) comprising a urea bond and a carboxy radical, as well as a sulfonyl bond and a carboxy radical, is expressed by, but not limited to, the following general formula:

CH ₃ - (CH ₂ ) _n -Z- (CH ₂ ) _m -COOH (V),

wherein 25 ≧ n ≧ 0, 26 ≧ m ≧ 1, and wherein Z is either NHCONH or SO ₂ . The number n + m is preferably at least 6, more preferably at least 8, and most preferably at least 10.

The melting point of the compound represented by the formula (IV) is pressed, is preferably at least 130 ° C, further be preferably at least 135 ° C and most preferably at least 140 ° C. Image erasability decreases with the increase in enamel point too. The melting point is also at most 200 ° C, be preferably at most 180 ° C, more preferably 170 ° C and most preferably at most 160 ° C. The heat sensitivity decreases the increase of the melting point too.

In addition, the melting point of the formula (V) is expressed compound preferably at least 135 ° C and beyond preferably at least 140 ° C. The image erasability increases with the Increase of the melting point too. The melting point is also preferably at most 190 ° C, more preferably at most 170 ° C and more preferably at most 150 ° C. The heat sensitivity increases as the melting point increases.  

Specific examples of the compound described above include the following, but are not on this be limits:

TABLE 1

Melting point (° C) (1) HOOC-CH ₂ -NHCO- (CH ₂ ) ₁₀ -CONH-CH ₂ -COOH 198 (2) HOOC- (CH ₂ ) ₂ -NHCO- (CH ₂ ) ₄ -CONH- (CH ₂ ) ₂ -COOH 197 (3) HOOC- (CH ₂ ) ₂ -NHCO- (CH ₂ ) ₈ -CONH- (CH ₂ ) ₂ -COOH 198 (4) HOOC- (CH ₂ ) ₂ -NHCO- (CH ₂ ) ₄ -CONH- (CH ₂ ) ₃ -COOH 187 (5) HOOC- (CH ₂ ) ₃ -NHCO- (CH ₂ ) ₄ -CONH- (CH ₂ ) ₃ -COOH 139 (6) HOOC- (CH ₂ ) ₃ -NHCO- (CH ₂ ) ₆ -CONH- (CH ₂ ) ₃ -COOH 144 (7) HOOC- (CH ₂ ) ₃ -NHCO- (CH ₂ ) ₈ -CONH- (CH ₂ ) ₃ -COOH 148 (8) HOOC- (CH ₂ ) ₃ -NHCO- (CH ₂ ) ₁₀ -CONH- (CH ₂ ) ₃ -COOH 150 (9) HOOC- (CH ₂ ) ₃ -NHCO- (CH ₂ ) ₁₂ -CONH- (CH ₂ ) ₃ -COOH 156 (10) HOOC- (CH ₂ ) ₃ -NHCO- (CH ₂ ) ₁₈ -CONH- (CH ₂ ) ₃ -COOH 151 (11) HOOC- (CH ₂ ) ₅ -NHCO- (CH ₂ ) ₂ -CONH- (CH ₂ ) ₅ -COOH 168 (12) HOOC- (CH ₂ ) ₅ -NHCO- (CH ₂ ) ₄ -CONH- (CH ₂ ) ₅ -COOH 146 (13) HOOC- (CH ₂ ) ₅ -NHCO- (CH ₂ ) ₆ -CONH- (CH ₂ ) ₅ -COOH 138 (14) HOOC- (CH ₂ ) ₅ -NHCO- (CH ₂ ) ₈ -CQNH- (CH ₂ ) ₅ -COOH 146 (15) HOOC- (CH ₂ ) ₅ -NHCO- (CH ₂ ) ₁₀ -CONH- (CH ₂ ) ₅ -COOH 145 (16) HOOC- (CH ₂ ) ₅ -NHCO- (CH ₂ ) ₁₂ -CONH- (CH ₂ ) ₅ -COOH 145 (17) HOOC- (CH ₂ ) ₁₁ -NHCO- (CH ₂ ) ₂ -CONH- (CH ₂ ) ₁₁ -COOH 144 (18) HOOC- (CH ₂ ) ₁₁ -NHCO- (CH ₂ ) ₄ -CONH- (CH ₂ ) ₁₁ -COOH 155 (19) HOOC- (CH ₂ ) ₁₁ -NHCO- (CH ₂ ) ₆ -CONH- (CH ₂ ) ₁₁ -COOH 135 (20) HOOC- (CH ₂ ) ₁₁ -NHCO- (CH ₂ ) ₁₀ -CONH- (CH ₂ ) ₁₁ -COOH 144 (21) HOOC- (CH ₂ ) ₁₁ -NHCO- (CH ₂ ) ₁₀ -CONH- (CH ₂ ) ₁₁ -COOH 148 (22) HOOC- (CH ₂ ) ₁₁ -NHCO- (CH ₂ ) ₁₂ -CONH- (CH ₂ ) ₁₁ -COOH 145 (23) HOOC- (CH ₂ ) ₂ -CONH- (CH ₂ ) ₁₂ -NHCO- (CH ₂ ) ₂ -COOH 181 (24) HOOC- (CH ₂ ) ₄ -CONH- (CH ₂ ) ₁₀ -NHCO- (CH ₂ ) ₄ -COOH 158 (25) HOOC- (CH ₂ ) ₄ -CONH- (CH ₂ ) ₁₂ -NHCO- (CH ₂ ) ₄ COOH 159 (26) HOOC- (CH ₂ ) ₅ -CONH- (CH ₂ ) ₈ -NHCO- (CH ₂ ) ₅ -COOH 143 (27) HOOC- (CH ₂ ) ₇ -CONH- (CH ₂ ) ₆ -NHCO- (CH ₂ ) ₇ -COOH 164 (28) HOOC- (CH ₂ ) ₁₀ -CONH- (CH ₂ ) ₄ -NHCO (CH ₂ ) ₁₀ -COOH 168

TABLE 2

Melting point (° C) (29) CH ₃ - (CH ₂ ) ₁₇ -NHCONH-CH ₂ -COOH 143 (30) CH ₃ - (CH ₂ ) ₁₇ -NHCONH- (CH ₂ ) ₂ -COOH 140 (31) CH ₃ - (CH _{2) 17} -NHCONH- (CH _{2) 3} -COOH 130 (32) CH ₃ - (CH _{2) 13} -NHCONH- (CH _{2) 2} -COOH 136 (33) CH ₃ - (CH _{2) 17} -SO ₂ - (CH _{2) 2} -COOH 136

The linear, carbon-containing compounds (B) can preferably those with as indicated in the tables above Melting points, and also a linear chain structure ha ben. The linear chain structure preferably has at least 8 Carbon atoms, more preferably at least 10 carbon atoms, and most preferably at least 12 carbon atoms. The linear chain structure also preferably has at most 50 Carbon atoms, more preferably at most 40 carbon atoms and most preferably at most 30 carbon atoms.  

Examples of the linear carbon-containing compounds (B) useful in the present invention do not limit alkanols; Alkandole; halogenated Al canols or halogenated alkanediols; alkyl amines; Alkanes: Alke ne; alkyne; halogenated alkanes; halogenated alkenes; on halogenated Named Alkyne; Cycloalkanes; cycloalkenes; Cycloalkyne; Esters of saturated or unsaturated monocarboxylic acids or saturated or unsaturated dicarboxylic acids or esters, amides and Am monium salts thereof; Arylcarboxylic acids and esters, amides and Ammonium salts thereof; halogenated arylcarboxylic acids as well Esters, amides and ammonium salts thereof; thioalcohols; Thiocar Bonsäuren and esters, amides and ammonium salts thereof; such as Carboxylic acid ester of thioalcohol.

These compounds can be used singly or in combination. These compounds have 10 to 60 carbon atoms, preferably 10 to 38 carbon atoms and more preferably 10 to 30 carbon atoms. Alcohol groups in these esters can be saturated, unsaturated or halogenated. It is preferred that the low molecular weight organic compounds in their molecule of oxygen, nitrogen, sulfur and halogen have at least one such as -CH, -COOH, -CONH, -COOR, -NH-, -NH ₂ , -S -, -SS-, -O- or halogen.

Specific examples of these compounds do not include restricting a monocarboxylic acid, a dicarbonic acid a fatty acid ester, a ketone with higher alkyl groups, an ester of a dibasic acid, a polyalkaline fatty acid acid ester, a fatty acid monoamide, a compound produced by the general formula (VI) is expressed, and a verbin , which is expressed by the general formula (VII). </ 83753 00070 552 001000280000000200012000285918364200040 0002019953569 00004 83634DL <

CH ₃ - (CH ₂ ) _n -X- (CH ₂ ) _m -COOH (VI),

wherein the melting point of the compound expressed by the formula (VI) is lower than 130 ° C, and wherein 26 ≧ n ≧ 0, 26 ≧ m ≧ 0, n + m ≧ 10 and Z is one of NHCONH, SO ₂ , CONH or NHCO.

HOOC- (CH ₂ ) _n -NHCO- (CH ₂ ) _m -COOH (VI),

wherein the melting point of the compound represented by the formula (VII) is lower than 130 ° C, and wherein 26 ≧ n ≧ 0, 26 ≧ m ≧ 0 and n + m ≧ 10.

Further examples of the linear, hydrocarbon-containing Compounds are provided in the present invention are useful and include the following compounds, but not limited to these.

Illustrative examples of monocarboxylic (fatty) acid include Lau ricinic acid, tridecylic acid, myristic acid, pentadecylic acid, palmi tic, margaric, stearic, nonadecylic, arachin acid, behenic acid, lignoceric acid, cerotic acid, montanic acid and melissic acid.

Illustrative examples of dicarboxylic acid include Bern stone acid. Glutaric acid, adipic acid, pimaric acid, suberic acid, Azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, Te tradecandic acid, pentadecanedioic acid, hexadecanedioic acid, heptade candic acid, octadecanedioic acid, nonadecanedioic acid, eicosanedioic acid, Heneicosanedioic and docosanedioic acid.

Specific examples of fatty acid esters for use in the present invention include octadecyl laurate, dococyl laurate, Dococyl myristate, dodecyl palmitate, tetradecyl palmitate, pentad cylpalmitate, hexadecyl palmitate, octadecyl palmitate, triacontyl palmitate, dococyl palmitate, vinyl stearate, propyl stearate, isopro pylstearate, butyl stearate, amyl stearate, octyl stearate, tetrade cylstearate, hexadecyl stearate, heptadecyl stearate, octadecylstea rat, dococyl stearate, hexacocyl stearate, triacontyl stearate, dode cylbehenate, octadecylbehenate, dococylbehenate, tetracocylligno cerat and melissyl myristate.  

Illustrative examples of the higher alkyl ketone include 8-pentadecanone, 9-heptadecanone, 10-nonadecanone, 11-henico sanon, 12-tricosanone, 14-heptacosanone, 16-hentriacontanone, 18- Entatriacontanone, 22-tritetracontanone, 2-pentadecanone, 2-hexa decanone, 2-heptadecanone, 2-octadecanone and 2-nonadecanone.

The dibasic acid esters can be either monoesters or diesters, which is expressed by the following general formula:

ROOC- (CH ₂ ) _n -COOR '(VIII)

where R and R 'are a hydrogen atom or an alkyl radical with 1 to 30 carbon atoms, and R and R 'either are equal or different, the case excluded that both are hydrogen at the same time; the number n is a whole Number from 0 to 40.

In the dibasic acid ester expressed by the above, all common formula (VIII), the carbon numbers of Al kylradikale R and R 'is 1 to 22 and is also the number n an integer from 1 to 30, more preferably from 2 to 20. The Melting temperature of the ester is preferably at least 40 ° C.

The specific examples of dibasic acid esters include Succinic diester, adipic diester, sebacic diester and 1- (18-) octadecamethylenedicarboxylic acid ester.

The polyalkanol difatty acid esters useful in the present invention are expressed by the following general formula:

CH ₃ (CH ₂ ) _m-2 COO (CH ₂ ) _n OOC (CH ₂ ) _m-2 CH ₃ (IX)

wherein the number n is an integer from 2 to 40, preferably 3 to 30, and more preferably from 4 to 22; and the number m one  is integer from 2 to 40, preferably from 3 to 30 and further preferably from 4 to 22.

The specific examples of the esters include 1,3-propanediol kanat, 1,6-hexanediol alkanate, 1,10-decanediol dialkanate and 1.18 Octadecandioldialkanat.

A fatty acid monoamide suitable for the present invention is expressed by the following general formula:

R ¹ -CONH-R ² (X),

wherein R ^{1 is} a linear hydrocarbon group containing at most 25 carbon atoms; R ^{2 is selected} from hydrogen, a linear hydrocarbon group containing at most 26 carbon atoms, and a methylol group; and of R ¹ and R ^2, at least one is a linear hydrocarbon group containing at most 10 carbon atoms.

Specific examples of the monoamide include nonanamide, decana mid, undecanamide, dodecanamide, tridecanamide, tetradecanamide, Hexadecanamide, octadecanamide, eicosanamide, docosanamide, trico sanamide, hexacosanamide and octacosanamide.

Explanatory examples of the connections that are determined by the general Formulas (VI) and (VII) are in the table 3 and 4, respectively.

TABLE 3

Melting point (° C) (34) CH ₃ (CH _{2) 13} -NHCONH- (CH _{2) 5} -COOH 117 (35) CH ₃ (CH _{2) 13} -NHCONH- (CH _{2) 5} -COOH 118 (36) CH ₃ (CH _{2) 17} -NHCONH- (CH _{2) 5} -COOH 119 (37) CH ₃ (CH _{2) 13} -NHCONH- (CH _{2) 7} -COOH 120 (38) CH ₃ (CH _{2) 13} -NHCONH- (CH _{2) 10} -COOH 122 (39) CH ₃ (CH _{2) 17} -SO ₂ -CH ₂ -COOH 118 ₂ (40) CH ₃ (CH _{2) 19} -SO ₂ -CH -COOH 120 (41) CH ₃ (CH _{2) 16} -CONH-CH ₂ -COOH 122 (42) CH ₃ (CH _{2) 16} -CONH- (CH _{2) 2} -COOH 120 (43) CH ₃ (CH _{2) 20} -CONH-CH ₂ -COOH 125 (44) CH ₃ (CH _{2) 11} -NHCO- (CH _{2) 4} -COOH 109 (45) CH ₃ (CH _{2) 17} -NHCO- (CH _{2) 4} -COOH 108

TABLE 4

Melting point (° C) (46) HOOC- (CH ₂ ) ₁₁ -NHCO- (CH ₂ ) ₂ COOH 127 (47) HOOC- (CH ₂ ) ₁₁ -NHCO- (CH ₂ ) ₄ COOH 123

In addition to the linear, hydrocarbons mentioned above Compounds (A) and (B) may also be of at least one kind an organic material of low molecular weight may be closed, which is characterized in that they has a melting point that is at least more than 10 ° C is higher than the compound (B), and never at least 10 ° C driger as the compound (A). These compounds can be in ge Suitably from the above-mentioned compounds (B) out choose to be.  

The heat-sensitive recording layer in the present Invention preferably has a thickness of 1 to 30 microns, farther preferably from 2 to 20 microns and most preferably from 4 up to 15 microns. Too much thickness of the recording layer causes the difficulty of equaling the recording layer transparent, because in the layer temperature fluctuations occur. Too small a thickness of the recording On the other hand, the layer causes a decrease in the white opa ken condition and contrast. By increasing the amount of alipha tic acids and / or crosslinking resin materials in the Recording layer, the white-opaque state can be increased.

The weight ratio of organic materials with niedri is molecular weight to the crosslinked resin materials 2: 1 to 1: 16, preferably 1: 2 to 1: 8, more preferably 1: 2 to 1: 5, more preferably 1: 2 to 1: 4, and most preferably 1: 2.5 to 1: 4.

A proportion of the resin below the above range causes a Difficulty in forming a film in which the organic Low molecular weight material retained in the resin remains. The amount of resin caused above the above range also a difficulty, and that when reaching the weissopa ken state, because the amount of organic material never low molecular weight.

Further, a protective layer may be formed on the recording layer be provided to prevent damage or impaired protection. Suitable materials for the protective layer with a thickness of 0.1 to 5 microns include silicone rubber or Silicone resin (Japanese Laid-Open Patent Application No. 63-221087), polysiloxane graft polymer (Japanese Laid-open Pa Patent Application No. 63-317385) and by ultraviolet radiation curable or electron beam curable resin (Japani Published Patent Application No. 2-566). In addition, you can organic or inorganic fillers included there Be where they are relevant.  

In addition, an intermediate layer between the protective layer and the recording layer be provided to the Aufzeich layer before solvents or monomer components in the layer-forming liquid to form the protective layer protect as in Japanese Patent Application Laid-Open No. 1-133781.

As the materials for the intermediate layer, the following thermosetting resins (thermoset resins) and thermoplastic Resins in addition to the previously used to form the recording layer mentioned resin materials are used. Examples suitable materials include polyethylene, polypropylene, butene lystyrene, polyvinyl alcohol, polyvinyl butyral, polyurethane, ge saturated polyester, unsaturated polyester, epoxy resin, phe nolharz, polycarbonate and polyamide. The thickness of the intermediate layer is preferably 0.1 to 2 microns. A thickness below The above area of the intermediate layer causes a problem during the protection of the recording layer, during which Ab Measurement above the above range, a reduction in the Wärmeemp caused sensitiveness.

The reversible thermosensitive recording medium of underlying invention can be effective together with another Da storage medium can be used. This is because of it accomplished that you can, for example, these two media a memory card: from the data storage medium on the reversible thermosensitive recording medium differs denominational information that is frequently rewritten saves (or transfers); and below the information in the reversible thermosensitive recording medium for the Eye makes recognizable. In this training of media and In The data may be handled directly by the cardholder by view to necessary data from the entire stored Get data access so that you can get the convenience considerably for users.  

The data storage medium mentioned above and in the invention is suitably used, any storage medium be as preferred, for example, a magnetic recording Medium, an integrated circuit (IC), a non-contact IC and an optical memory. Magnetic layers to Bil Magnetic recording media include those Iron oxides and barium ferrites on a substrate either by applying a coating composition containing Ure than- or nylon resins mixed, or by depositing oh ne resins are formed, for example by the vacuum Ver steam or vacuum spray method (sputtering).

The portions of the magnetic recording medium may be (1) be provided on the side of the substrate, the reversib len, heat-sensitive recording layer opposite is, (2) between the substrate and the reversible, heat sensitive recording layer or (3) on sections of the reversible, heat-sensitive recording layer.

The reversible thermosensitive recording medium can also serve as part of a data storage medium, by Her position of a bar code or two-dimensional code. From These storage media may preferably be the magnetic recording and IC memories can be used in the present invention.

A layer of glue or pressure-sensitive adhesive can also be formed on the back of the substrate to a reversible thermosensitive recording label form. All materials commonly used as glue or pressure sensitive glue can also be used in the pre underlying invention.

Examples of materials of the adhesive layer do not include restricting urea resins, melamine resins, phenolic resins, epoxy resins, vinyl acetate resins, vinyl acetate-acrylic copolymers, ethylene Vinyl acetate copolymers, acrylic resins, polyvinyl ether resins, vinyl  chloride-vinyl acetate copolymers, polystyrene resins, polyester resins ze, polyurethane resins, polyamide resins, chlorinated Polyolefinhar ze, polyvinyl butyral resins, acrylate copolymers, methacrylate copo polymers, natural gums, cyanoacrylate resins and silicone resins. The adhesive layer may be composed of a hot melt adhesive material be set. If a label is used, then a used either with or without removable paper who the.

By additional use of the layer thus prepared Glue or pressure-sensitive adhesive can be a reversible, heat-sensitive recording label are formed. With the adhesive layer can be reversible, heat-sensitive Recording material therefore provided even on surfaces be such as the entire surface or parts of a relatively thick substrate of a polyvinyl chloride card on the magnetic stripes are present where the coating is on drawing material is generally difficult to achieve. of Half parts of the information data previously stored in the magneti stored data storage medium, thus on the right versatile, heat-sensitive recording layer by sight become recognizable, so that one is able to be comfortable considerably for users.

In addition to the above polyvinyl chloride card, on the magneti If the strip is present, this can be done with the adhesive layer see, reversible, heat-sensitive recording label too used together with relatively thick memory cards, like IC cards or optical memory cards.

The reversible thermosensitive recording label can also be used as a display label on the surface of a disk or disk cartridge housing a rewritable memory disk such as a floppy disk, MD (micro disk) or DVD-RAM. Figure 4 is also included to illustrate the reversible thermosensitive recording label as it is placed on the front surface of an MD disk cartridge.

Further, for example, in the case of a CD-RW disk or -Dis chain, for which no floppy disk is generally used, a reversible, heat-sensitive recording label sticks directly to the end face of the disk or plate stuck. Therefore, the record label may be conveniently used in a variety of ways so that its display content may be caused to automatically change (or rewrite) in accordance with the change in the original content of the data storage medium. Fig. 5 illustrates a reversible thermally sensitive recording medium applied directly to the front surface of a CD-RW disc.

Still further becomes a reversible, thermally sensitive record label directly on the end face of a wiederbe writable, optical Dikette or plate applied, such as a CD-R disk or disks, wherein the shares of Informa originally stored in the CD-R floppy disk be transferred to the label in order subsequently to the sem to be displayed.

Fig. 6 illustrates an embodiment of a reversible, heat-sensitive recording label applied to an optical information storage medium (CD-RW) using an AgInSbTe phase-change recording material.

The storage medium has a basic configuration that is a sub Strat with a guide groove with the following, adjacent Has layers on it in the order mentioned are formed: a first dielectric layer, an opti data storage layer, a second dielectric layer, a reflection and heat dissipation layer, an intermediate layer, as well as a hard coating layer on the back of the Substrate. In addition, is a reversible, heat-sensitive  Recording label applied to the intermediate layer. The Dielectric layers are not necessarily on the provided on both sides of the data storage layer. Also is the first dielectric layer is preferably provided in the case in which the substrate is formed of resin materials ver have relatively low melting points, such as. B. polycarbo natharz.

A reversible thermosensitive recording label is also mounted on the face of a video cassette as shown in FIG .

In addition to the above-mentioned method, which would be reversible sensitive material in the form of a label on a rela tively thick disk provided, the heat-sensitive Ma terial can also be applied directly, or can be from one other carrier ago, the heat-sensitive material before carries on the surface of the diskette or floppy disk be transmitted by yourself. What the above transmission method As far as a layer of a type of hot-melt adhesive is concerned or pressure-sensitive adhesive in a suitable manner det by placing them on the heat-sensitive layer applies. If the heat-sensitive layer or its label on a stiff surface z. As a card, diskette, case or Tape cassette is provided, a padding bow or a Padding layer preferably inserted between the rigid substrate be brought to a satisfactory contact with a heat reach the print head. This makes it possible, satisfying, constant conditions during the entire image forming process sustain.

If that is on the reversible, heat-sensitive recording Layered image used together with a barcode It is preferred that a light reflection layer be behind the recording layer is used. The reflection layer can the white-opaque density of the white-opaque parts of the  layer and also the contrast. This made possible light the increase in the accuracy of the data reading. The reflect Xionsschicht can as a thin film or vapor-deposited layer Metal such as formed.

When the reversible thermosensitive recording medium with both (1) rewritable bar code sections, which are commonly used be recognized by a reading unit, as well as with (2) other sections that contain both images and also have alphanumeric characters and of human Eyes are perceived by sight, these two are Ab cuts preferably as at least two different Ab formed sections that a respective reflectivity to have.

It is to be preferred that on the back of the line Code sections a light reflection layer is provided, currency a light-absorbing or colored layer on the Rear of the visible sections visible provided is. This is considered as follows.

If the latter sections are recognized by sight, then the eyes in general can make the color difference come true as well as reflected the difference in intensity Light between white-opaque sections and colored ten, picture-free sections. By arranging the color layer may also have an excessively intense shine from the re flexing sections ago at a certain angle be suppressed to thereby observe images facilitate on the reversible recording layer are shaped.

By contrast, if the same images are from a reading unit, such as B. from a reflectance spectrometer or bar code reader be read, the measuring unit in general perpendicular to Surface of the recording layer is aligned to the  coming light rays at an angle. Of course, this leads out formation of incorrectly observed values of the image contrast, which are attenuated by the absorption of light by dis Color layer is caused.

Accordingly, it is highly desirable that the reversible would be photosensitive recording medium of the present invention is formed so that it has at least two sections, which are preferably designed so that they have a respective Re flexion capability, so that a light reflection layer on the back of the barcode sections and a light absorber Baking or colored layer at the back of the by sight recognizable sections is formed. In this training Not only will the images be reversible, heat sensitive union recording medium are formed, by view with high Contrast observed, but also with the reading unit measured with sufficient accuracy.

Referring to Fig. 8A; The reversible, heat-sensitive recording medium of the present invention may be preferably formed as a film comprising a substrate 11 having a reversible thermosensitive recording layer 13 formed thereon and a protective layer 14 further formed thereon.

However, as shown in Fig. 8B, the reversible thermosensitive recording medium may be preferably formed as a film comprising a substrate 11 having a reflective layer 12 made of Al formed thereon, a reversible thermosensitive recording layer 13 formed thereon. and a protective layer 14 further formed thereon.

Further, the reversible thermally sensitive recording medium may also be formed as a film as shown in Fig. 8C comprising a substrate 11 having a reflective layer 12 formed thereon of Al, a reversible thermally sensitive recording layer 13 formed thereon, and a further formed thereon Protective layer 14 comprises, with a magnetic recording layer 16 , which is further formed on the back of the sub strate.

In addition, these foils 22 may each be provided on the end face of a card 21 on which there is also a printed display section 23 .

Still further, the reversible thermosensitive recording medium may be formed as a card, as shown in Fig. 9A, comprising a substrate 11 having a reversible thermosensitive recording layer 13 formed thereon and a protective layer 14 further formed thereon. This film is then shaped to be card-like, further having a concave portion 23 to engage e.g. B. to record an IC chip.

In the present embodiment, a rewritable storage portion 24 serves as a label, and a concave portion 23 is formed in a predetermined portion on the back side of the card for a wafer substrate 231 to be fixed, as shown in Fig. 10B. Integrated circuits 233 are fabricated on the wafer substrate 231 . A variety electrical shearing contact terminals 234 are connected thereto, and the se terminals 234 are exposed to the back side of the wafer 232 to be electrically connected to extract relevant information data by means of an exclusive printer or a read / write means and recording again.

Operating characteristics of the reversible thermosensitive recording card will be described below with reference to Figs. 11A and 11B, for example.

Fig. 11A is a block diagram showing the construction of the IC (integrated) circuit 233 , and Fig. 11B is a block diagram showing the structure of the memory data in a random access memory (RAM).

The integrated circuit (IC circuit) is composed of, for example, a large scale integration element (LSI). In the LSI, a central processing unit (CPU) 235 for performing control of steps in a predetermined order, a read-only memory (RDM) 236 for storing program data for the CPU operation, and an access memory (RAM) 237 for the read / write operations of neces sary data includes. In addition, the IC circuit 233 includes an input-output interface (I / O interface) 238 for inputting / outputting data signals in response to the input, and other circuits (not shown) such as power-on Reset circuit, a circuit for generating a pulse step signal, a pulse dividing circuit (or circuit for generating an interrupt signal) and an address decoding circuit.

The CPU 235 is capable of executing interruption control routines in response to interruption signals which are periodically input. The address decoding circuit de encodes address data output from the CPU 235 , and subsequently inputs necessary signals to the ROM 236 , the RAM 237, and the I / O interface 238, respectively.

Through a plurality of control terminals (ie, 8 terminals shown in FIG. 11A) connected to the I / O interface 238 , required data output from the printer (or the read-write unit) is input to the CPU 235 entered.

The CPU 235 then executes predetermined processing steps in response to inputted signals and / or program data previously stored in the ROM 236 , and thereafter outputs the required data and signals to the printer through the I / O interface 238 .

The RAM 237 includes a plurality of storage regions 239 as shown as 239a to 239f in FIG. 11B. There are each a card number 239 a; Surname. Address, telephone number and other information about the cardholder in the region 239 b; the card balance and other data of the value item for the cardholder in the region 239 c; and sales records of the values by the card owner in the regions 3239d , 239e , 239f and 239g .

The methods of writing and deleting images used in the reversible thermosensitive recording medium of the invention are suitable, are carried out as follows.

The writing of the images is done by heating means leads, such. As a thermal print head or laser, the capable is to heat the sections of already existing images. The deletion of images is done by various means performed a hot stamp, a ceramic heater direction, a heating roller, a stream of hot air, a heat printhead and a laser. From these means will a ceramic heater is preferably used, the sta bile deletion and high contrast images with minimal build Ensures Lich effort. The temperature used for heating the ceramic unit is suitable is preferably minde at least 110 ° C, more preferably at least 112 ° C and most preferably at least 115 ° C.

When using a thermal print head, the extinguishing device be further miniaturized, and the power consumption of Device can be further reduced, which z. Legs Portable extinguishing device allows for a battery power supply has.

When both writing and deleting pictures with a single thermal print head is performed, then this will by causing either (1) new pictures to be deleted the entirety of the old pictures writes, or (2) new pictures  Immediately after you picture the old pictures has cleared, with variable heating power for each picture, what one generally calls the overwriting method. That is why the Total time for writing and deleting with this overwrite verifier Drive down to faster data processing receive.

In addition, the reversible, heat-sensitive record tion medium of the invention even further with another data provided memory medium, as mentioned above, so that the Informati transferred onsabschnitt in the other data storage medium and in the reversible, heat-sensitive recording medium by sight can be made visible / visible. He can do this be enough, that you both reading and overwriting in addition to the above-mentioned heaters provides.

Referring now to Figs. 12A and 12B; Recording devices are described which can be suitably used for the reversible thermosensitive recording medium of the present invention.

In the apparatus schematically shown in Fig. 12A, a ceramic heater is used as an image forming or writing means, while a thermal printing head is used as a quenching direction. Referring again to FIG. 12A, reference is made. Information data previously recorded in a magnetic recording layer is first read by a magnetic head, then old image information in the reversible thermosensitive recording medium is warmed to be erased, and new image data updated based on the current magnetic head data is updated are recorded in the reversible, heat-sensitive recording medium with the thermal print head. Subsequently, the image data in the magnetic recording layer is also updated.

In the present embodiment, a reversible would be meempfindliches recording medium used with a Magnetic recording layer is provided on the Back of the medium made of a reversible, heat-sensitive Layer is formed.

In Fig. 12A, the reversible thermosensitive recording medium 1 may be displaced either in a first direction (eg, to the right) or a second and opposite direction (eg, to the left) via a conveying path indicated by a double arrow is shown. Along the conveying path, the apparatus for the reversible thermosensitive recording medium is operated as follows: (1) the data in the magnetic recording layer is net updated (ie, recorded and / or erased) during passage between a magnetic head 34 and a platen roller 40 mag. (2) the image data in the reversible medium is heated / erased during passage between a ceramic heater 38 and a roller 40 , and (3) image data in the reversible medium is rewritten during passage between a thermal head 53 and a roller 47. updated. After that, the reversible thermosensitive recording medium is released from the device.

As previously described, the temperature suitable for heating the ceramic unit 38 is preferably at least 110 ° C, more preferably at least 112 ° C, and most preferably at least 115 ° C.

It may be noted that the data updating steps may be performed either before or after erasure of the image data with the ceramic heater. If appropriate, the reversible thermally sensitive recording medium can also be displaced immediately after the passage either between the ceramic heater 38 and the roller 40 or between the thermal head 53 and the roller 47 in the reverse direction, thereby being able to do so to be treated again with the ceramic heater 38 and the heat pressure head 53 .

In another embodiment, as shown in Fig. 12B, a reversible, heat-sensitive recording medium 1 inside the device either in the forward or backward direction along a path 50 is added, which is represented by a ge dotted line.

After being fed from a feed slot 30 , the rever sible, heat-sensitive medium 1 by means of a feed roller 31 and a guide roller 32 through the interior of the device promotes GE. Upon arrival at a particular position along the path 50, the recording medium 1 is detected by a sensor 33, and the data in the magnetic recording layer are updated by a control unit 34 C magnetic (recorded that during the passage between a magnetic head 34 and a platen roller 35 and / or deleted).

Subsequently, the recording medium is further displaced by a guide roller 36 and another conveying roller 40 , and passes between a guide roller 39 and a conveying roller 40 through to a point where the recording medium is detected by a sensor 43 . At this point, the sensor 43 activates, together with a control unit, operations for heating the ceramic heater to thereby perform heating / extinguishing steps during the passage between a ceramic heater 38 and a roller 44 .

The recording medium is further moved by conveying rollers 45 , 46 , 47 along the path 50 until it is detected at another, bestimm th point by another sensor 51 . At this point, the process of rewriting / updating the image data in the reversible medium during the passage between a thermal print head 53 and a platen roller 52 is activated.

Subsequently, the reversible, heat-sensitive Aufzeich tion medium of the machine along a conveying path 56 a by a conveying roller 59 , a guide roller 60 and an exit slot 61 is released.

The temperature suitable for heating the ceramic unit 38 is preferably at least 110 ° C, more preferably at least 112 ° C, and most preferably at least 115 ° C, as previously described.

In addition, the reversible, heat-sensitive recording medium can also, if appropriate, be re-treated with the heat-pressure head 53 . This is achieved by (1) first by switching a conveying path Umschalteinrich device 55 a, the recording medium another path 56 b supplies. (2) The recording medium is then moved by a conveyor belt 58 in the backward direction, which moves in the reverse direction after it has been turned on by a limit switch 57 a, which was activated by pressure due to the weight of the recording medium. Be tet (3) machining data between the thermal print head 53 and the platen roller 52 upon arrival of the medium, (4) it is the direction 55 is formed by activating a way Umschaltein b in a forward direction along a feed path 49 b moved, (5) It then runs along the conveyor belt 48 after activating a limit switch 57 b back, and (6) it is subsequently released from the device after it has passed along the path 56 a over the guide roller and through the exit slot 61 .

The above divided conveying paths and the Förderweg-Umschaltein directions, which are able to choose among the plurality of divided paths one, are seen in another embodiment, also on each side of the ceramic heater 38 provided. In this case, a sensor 43 a is preferably provided between the pressure roller 44 and the conveying roller 45 .

After this invention has been generally described, a further understanding by reference to specific examples which are presented here for purposes of explanation only see and are not intended to be limiting. In the Be The following examples are numerals of weighted acronyms le, unless stated otherwise.

EXAMPLES EXAMPLE 1

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made of the steps and devices.

An arc of a roll of magnetic raw material was called supporting substrate used, which consists of a film of polyethy lenterephthalate was composed with a magnetic Recording layer and a self-cleaning layer be was layered as the Memorydick DS-1711-1040 by Dainippon Ink and Chemicals Inc. is available.

A layer of aluminum was deposited on the polyethylene terephthalate lattice of the substrate using a vacuum evaporator depressed to a light reflection layer with a thickness of 400 Å. A Beschich The composition for forming an adhesive layer was then produced by mixing the following components.

Vinyl chloride-vinyl acetate Phosphoresterkopolymer @ (Denka Vinyl # 1000P by Denki Kagaku Kogyo Co) 10 parts methyl ethyl ketone 45 parts toluene 45 parts

The coating composition thus prepared was named Be layer applied to the Al reflective layer and ge  dries to a 0.5 micron thick adhesive layer to build.

A disperse solution A was then prepared as follows: to 50 parts of a tetrahydrofuran solution containing 15% solids of polyvinyl chloride copolymers (MR110 from Nippon Zeon Co.) was added 1.5 parts of HOOC- (CH ₂ ) ₅ -NHCO- ( CH ₂ ) ₄ -CONH- (CH ₂ ) ₅ - COOH. The mixture thus prepared was further mixed by stirring for 48 hours in a glass bottle which also contained glass beads about 2 millimeters in diameter, using a paint stirrer (from Asada Tekko Co.).

A dissolving liquid B was prepared by mixing the following components:

Behenic acid (# 95 from Miyoshi Oil and Fat Co.) 1.1 part Eicosanedioic acid (SL-20-90 from Okamura Qil Co.) 0.25 parts Vinyl chloride copolymer (MR110 from Nippon Zeon Co.) 3.0 parts tetrahydrofuran 17.0 parts o-xylene 6.0 parts

Subsequently, a coating composition was prepared by mixing the following solutions and components:

Disperse Solution A 7.8 parts Dissolving liquid B 27.0 parts Isocyanate compound (Nippon Polyurethane Industry Co.) 0.6 parts

The coating composition thus prepared was named Be coating applied to the adhesive layer, previously formed was, as described above, with the underlying ma magnetic recording with the polyethylene terephthalate substrate, and was dried to a heat-sensitive layer with  to form a thickness of about 11 microns. The heat-sensitive Layer was further cured by placing it at 60 ° C 72 Let stand for hours.

Another coating composition was prepared by mixing the following components:

AL = L <75% solution of urethane acrylate-based, UV-curing resin (Unidec C7-157 from Dainippon Ink and Chemicals Inc) in butyl acetate 10 parts isopropyl alcohol 10 parts

The coating composition thus prepared was washed with a wire rod piled on the recording layer, dried and irradiated with ultraviolet from a high pressure mercury lamp irradiated with about 80 W / cm to a deck layer with a thickness of about 3 microns.

Subsequently, the thus formed recording medium was passed through Heat to 150 ° C for 10 seconds on a hot plate in spent white-opaque state and then at 90 ° C one minute long in a constant temperature oven transparent makes, whereby a reversible. Heat sensitive record was prepared.

EXAMPLE 2

Another reversible thermosensitive recording medium according to the present invention was prepared in accordance with the following steps and apparatus:
An aluminum layer was beaten on a polyester film to form a light-reflecting layer. The polyester film was used as a supporting substrate for the recording medium and was available from Toray Co. (Lumilar # 125 having a thickness of about 125 microns).

A coating composition for forming an adhesive layer was prepared by mixing the following components:

AL = L <vinyl chloride-vinyl acetate-phosphoric acid copolymer (Denka-vynyl # 1000P by Denki Kagaku Kogyo Co.) 10 parts methyl ethyl ketone 45 parts toluene 45 parts

The coating composition thus prepared was applied to Light reflection layer of Al coated as a coating and dried to an adhesive layer with a thickness of 0.5 microns to build. Hereinafter, in a manner similar to Example 1, was then on a heat-sensitive recording layer Ge forms and a coating layer was further formed thereon, whereby a reversible, heat-sensitive recording medium was produced. Furthermore, the thus formed Auf Drawing medium in a manner similar to Example 1 heat delt, thereby the white-opaque state and then the trans parenz.

The reversible thermosensitive recording medium of underlying invention was prepared.

Furthermore, a layer of adhesive on the back of the Recording medium provided zusammenge composed of acrylic resin was set and had a thickness of about 5 microns, creating a reversible thermosensitive recording label formed has been. Subsequently, the recording label was placed on the upper surface of a CD-RW disc (rewritable CD disc) brought, thereby producing an optical data storage medium which included reversible display options.

The optical data storage medium thus prepared was subjected to the following experiment:
Information data such as dates and times were first stored in the CD-RW disc by a CD-RW drive (MP 62005 from Ricoh Co.). The portions of this information were then transferred to the reversible thermosensitive recording layer using a writing / recording apparatus (a thermal printhead) and a quenching apparatus (a ceramic heater), each recording power of the thermal printhead being adjusted depending on the recording temperature of the recording medium , As a result, the transmitted information data was successfully displayed and recognized by visualization on the reversible heat-sensitive recording label.

After the previous information data in the CD-RW disc rewritten and the old displayed data in the record label with the deletion device was deleted In addition, a new set of information data new in the up Drawing label written with the thermal print head. The new written information data was again successful the reversible, heat-sensitive recording label ange ange shows. This process was subsequently repeated up to 50 times brings, and one found the writing and extinguishing results satisfactory quietly.

EXAMPLE 3

A reversible thermosensitive recording label was prepared in a similar manner to Example 2.

The reversible thermosensitive recording label was subsequently on the surface of an MD diskette case which made a data storage medium that was reversible display options included.

Information data such as dates and music titles were in the MD-Dis chain already saved. Parts of this information were then into the reversible thermosensitive recording layer  using a writing / recording device (a Thermal print head) and a quenching device (a ceramic Heating device) while transferring the energy of the heat printhead as a function of the recording temperature of the Set recording medium. As a result, the over displayed data successfully and by view on the reversible, heat-sensitive recording medium recognized.

After the old displayed data in the recording medium with the extinguisher were deleted, in addition, again a new set of informational data into the recording file chain written with the thermal print head. The newly written Information data was again on the reversible record label displayed. This process was subsequently 50 times repeated, and you found the write and erase results be satisfactorily.

COMPARATIVE EXAMPLE 1

In accordance with the following steps became a wide res, reversible, thermosensitive recording medium of produced according to the present invention.

In a manner similar to Example 1, a light reflection layer and an adhesive layer on the surface of Polyethy lenterephthalate film of the magnetic raw material roll gebil det.

A coating composition for forming a heat temp The sensitive recording layer was then mixed by mixing following components.

Hexadecanedioic acid (from Tokyo Kasei Co.) Part 1 Stearyl behenate (from Sigma Co.) 5 parts Vinyl chloride-vinyl acetate copolymer (VMCH from Union Carbide Co.) 12 parts 1,9-nonanediol diacrylate 4 parts Photopolymerization initiator (Irgacure 184 from Ciba-Geigy Co.) 0.2 parts Photo-Curing Resin (S-2040 from Toa Gosei Co.) 26.7 parts tetrahydrofuran 140 parts

The coating composition thus prepared was used as Layer applied to the adhesive layer, dried and with an ultraviolet radiation from a high-pressure mercury Overloaded with about 80 W / cm irradiated to a heat sensitive Layer with a thickness of about 11 microns.

A coating layer was subsequently applied to the heat sensitive recording layer in a manner similar to Example 1 ge forms, creating a reversible, heat-sensitive Aufzeich was prepared medium.

COMPARATIVE EXAMPLE 2

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made the steps.

In a manner similar to Example 1, a light reflection layer and an adhesive layer on the surface of the polyethylene lenterephthalate film of the magnetic raw material roll gebil det.

A coating composition for forming a heat temp The sensitive recording layer was then mixed by mixing following components.

1,18-octadecadicarboxylic acid dodecyl (Miyoshi Oil and Fat Co.) 2.4 parts Eicosanedioic acid (SL-20-99 from Okamura Oil Co.) 2.6 parts AL = L <vinyl chloride-vinyl acetate copolymer (M2018 with 80% vinyl chloride, 20% vinyl acetate and an average degree of polymerization of 1800 by Kaneka Co.) 14.0 parts Reaction Polymeric Species (NK polymer B-3015H from Shin Nakamura Kagaku Co.) 2.4 parts Photopolymerization initiator (Irgacure 184 from Ciba-Geigy Co.) 0.1 parts tetrahydrofuran 108 parts amyl alcohol 12 parts

The coating thus prepared was applied as a layer on the Adhesive layer applied, dried and with ultraviolet Radiation from a high-pressure mercury lamp with about 80 W / cm irradiated to a heat-sensitive layer with a thickness of about 11 microns.

Subsequently, on the heat-sensitive layer over Tensile layer formed in a manner similar to Example 1, whereby a reversible thermosensitive recording medium is was.

EXAMPLE 4

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made the steps.

In a similar manner as in Example 1, a Lichtreflexi onsschicht and an adhesive layer on the surface of the poly ethylene terephthalate film of the roll of magnetic raw material educated.

A disperse solution B was prepared as follows. To 50 parts of tetrahydrofuran solution containing 15% solids of urethane resin (Nipporan 3151 at 35% solids from Nippon Polyurethane Industry Co.) was added 1.5 parts of HOOC- (CH ₂ ) ₅ -NHCO- (CH ₂ ) ₄ - CONH- (CH ₂ ) ₅ -COOH added. The mixture thus prepared was further mixed by stirring in a glass bottle for 48 hours, which also contained glass beads about 2 millimeters in diameter, using a paint mixer (from Asada Tekko Co.).

A dissolving liquid C was prepared by mixing the following Components made.

Behenic acid (# 95 from Miyoshi Qil and Fat Co.) 1.1 parts Eicosanedioic acid (SL-20-99 from Okamura Oil Co.) 0.25 parts AL = L <Polyurethane resin (Nipporan 3151 at 35% solids from Nippon Polyurethane Industry Co.) 15.6 parts tetrahydrofuran 17.1 parts o-xylene 4.43 parts

Subsequently, a coating composition for formation a heat-sensitive recording layer by mixing of the following solutions and components.

Disperse Solution B 2.2 parts Solution liquid C 26.6 parts Isocyanate Compound (Coronate HK from Nippon Polyurethane Industry Co.) 0.25 parts

The coating composition thus prepared was applied to previously formed as described above adhesive layer as Beschich applied, with the underlying magnetic Auf drawing together with the polyethylene terephthalate substrate, and dried to a heat-sensitive layer having a thickness  of about 11 microns, similar to Example 1. Further was then a coating layer with a thickness of about 3 Micron similar to that formed in Example 1.

Subsequently, the thus formed recording medium became similar heat-treated as in Example 1. Namely, the medium became by heating to 150 ° C for 10 seconds in the white opaque stood and then by heating to 90 ° C for one minute made transparent in a constant temperature oven, whereby a reversible, heat-sensitive recording medium was produced.

EXAMPLE 5

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made the steps.

Similar to Example 1, a light-reflecting layer and an adhesive layer on the surface of the polyethylene tereph Thalatfolie a roll formed with magnetic raw material.

As a disperse solution was also a disperse solution A similar as used in Example 1. In addition, a Lö liquid D by mixing the following components posed.

Behenic acid (# 95 from Miyoshi Qil and Fat Co.) 1.1 parts Eicosanedioic acid (SL-20-99 from Okamura Oil Co.) 0.25 parts Vinyl chloride copolymer (MR110 from Nippon Zeon Co.) 2.81 parts tetrahydrofuran 18.6 parts o-xylene 4.0 parts

Subsequently, a coating composition for formation a heat-sensitive recording layer by mixing the following solutions and components.

Disperse Solution A 6.18 parts Solution liquid D 20.4 parts Isocyanate Compound (Coronate 2298-90T from Nippon Polyurethane Industry Co.) 0.45 parts

The coating composition thus prepared was named Be coating applied to the adhesive layer, previously formed was, as described above, with the underlying magnet layer together with the polyethylene terephthalate substrate, and dried to heat in a similar manner as in Example 1 sensitive layer to form, which has a thickness of about 11 Mi kron has. Further, similar to Example 1, a Coating layer formed, which has a thickness of about 3 microns te.

Subsequently, the thus formed recording medium was placed on a Similar to Example 1 by heating to 150 ° C 10 sec Cured for a long time on a hot plate to keep it white produce opaque state, and then at 90 ° C for 1 minute heated in a constant temperature oven to ensure transparency to provide. The reversible, heat-sensitive recording medium was made that way.

EXAMPLE 6

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made the steps.

In a manner similar to Example 1, a Lichtre flexion layer and an adhesive layer on the surface  the polyethylene terephthalate film of a roll of magnetic Raw material formed.

The disperse solution was also similar to a disperse solution A. as used in Example 1. Additionally, a solution flow became E by mixing the following components provides.

Behenic acid (# 95 from Miyoshi Oil and Fat Co.) 1.1 parts Eicosanedioic acid (SL-20-99 from Okamure Oil Co.) 0.25 parts Vinyl chloride copolymer (MR110 from Nippon Zeon Co.) 2.81 parts tetrahydrofuran 18.6 parts o-xylene 4.0 parts

Subsequently, a coating composition for formation a heat-sensitive recording layer by mixing of the following solutions and components.

Disperse Solution A 6.18 parts Solution liquid E 20.4 parts Isocyanate Compound (Coronate 2298-90T from Nippon Polyurethane Industry Co.) 0.61 parts

The coating composition thus prepared was named Be coating applied to the adhesive layer, as described above written before, with the Ma below gnetschicht together with the polyethylene terephthalate substrate, and dried to be in a manner similar to Example 1 a sensitive layer about 11 microns thick form. Furthermore, a coating layer with a Thickness of about 3 microns similar to that formed in Example 1.

Subsequently, the thus formed recording medium was placed on a Method similar to Example 1 by heating to 150 ° 10 seconds  long heat-treated on a hot plate to add the white-opaque to bring forth, then by heating to 90 ° C for 1 minute long in a constant temperature oven the transparency too achieve. Thus, the reversible heat-sensitive record was prepared medium.

EXAMPLE 7

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made the steps.

In a manner similar to Example 1, a light reflection layer and an adhesive layer on the surface of Polyethy lenterephthalate film from the roll of magnetic raw material manufactured.

A coating composition for forming a heat temp The sensitive recording layer was then mixed by mixing following components.

Behenic acid (# 95 from Miyoshi Oil and Fat Co.) 0.8 parts Eicosanedioic acid (SL-20-99 from Okamura Oil Co.) 0.8 parts Vinyl chloride polymer (MR110 from Nippon Zeon Co.) 4.2 parts tetrahydrofuran 25.7 parts o-xylene 4.5 parts Isocyanate Compound (2298-90T from Nippon Polyurethane Industry Co.) 0.66 parts

The coating composition thus prepared was applied to as described previously formed adhesive layer as Be layered, with the underlying magnetic layer  together with the polyethylene terephthalate substrate, and getrock net to a heat-sensitive layer with a thickness of about 11 microns in a manner similar to that of Example 1 to form. Further, a coating layer having a thickness of about 3 microns on this in a manner similar to that of Example 1 ge forms. Thus, the reversible heat-sensitive record was prepared medium.

EXAMPLE 8

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made the steps.

In a manner similar to Example 1, a light reflection layer and an adhesive layer on the surface of Polyethy lenterephthalate film of the roll of magnetic raw material educated.

The disperse solution was also a disperse solution A. which was prepared in a similar manner as in Example 1 de. In addition, a dissolving liquid F was mixed by mixing formed of the following components.

12-Tricosanone (from Tokyo Kasei Co.) 0.82 parts 14-heptacosanone (from Tokyo Kasei Co.) 0.28 parts Eicosanedioic acid (SL-20-99 from Okamura Qil Co.) 0.25 parts Vinyl Chlorocopolymer (HR110 from Nippon Zeon Co.) 2.81 parts tetrahydrofuran 18.6 parts o-xylene 4.0 parts

Subsequently, a coating composition for formation a heat-sensitive recording layer by mixing of the following solutions and components.  

Disperse Solution A 6.18 parts Dissolving liquid F 20.8 parts Isocyanate Compound (Coronate 2298-90T from Nippon Polyurethane Industry Co.) 0.5 parts

The coating composition thus prepared was named Be layering on the before, as described above, structure applied adhesive layer, with the underlying magneti layer together with the polyethylene terephthalate substrate, and dried to be in a manner similar to Example 1 a sensitive layer about 11 microns thick form. Furthermore, a coating layer with a Thickness of about 3 microns in a manner similar to Example 1 ge forms.

Subsequently, the thus formed recording medium was placed on a Example 1 by heating to 150 ° C for 10 sec customers to bring about the white-opaque state and then by heating at 90 ° C for 1 minute in a constant oven heat to produce the transparency heat treated. So became the reversible thermosensitive recording medium manufactured.

EXAMPLE 9

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made the steps.

In a manner similar to Example 1, a light reflection layer and an adhesive layer on the surface of the poly ethylene terephthalate film of a magnetic raw-roll formed.  

As a disperse solution, the disperse solution A also became similar used in Example 1. In addition, a solution became liquid G produced by mixing the following components.

Diphenyl behenate (from Sigma Co.) 1.1 parts Eicosanedioic acid (SL-20-99 from Ckamura Oil Co.) 0.25 parts Vinyl chloride copolymer (M110 from Nippon Zeon Co.) 2.81 parts tetrahydrofuran 18.6 parts o-xylene 4.0 parts

Subsequently, a coating composition for formation a heat-sensitive recording layer by mixing of the following solutions and components.

Disperse Solution A 6.18 parts Solution liquid C 20.8 parts Isocyanate Compound (Coronate 2298-90T from Nippon Polyurethane Industry Co.) 0.5 parts

The coating composition thus prepared was applied to earlier, as described above, formed adhesive layer than Coated with the underlying magneti layer, together with the polyethylene terephthalate sub strat, and was dried to be similar in a similar way to example 1, a heat-sensitive layer about 11 microns thick form. Furthermore, a coating layer with a Thickness of about 3 microns similar to Example 1 formed.

Subsequently, the thus formed recording medium became similar as in Example 1 by heating to 150 ° C for 10 seconds a heating plate for causing the white-opaque state and then by heating to 90 ° C for 1 minute in an oven with constant temperature to achieve the transparency heat  delt. The reversible thermosensitive recording medium was made that way.

EXAMPLE 10

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made the steps.

Similar to Example 1, a light-reflecting layer and an adhesive layer on the surface of the polyethylene terephthalate film of the roll formed with magnetic raw material.

A coating composition for forming a heat temp The sensitive recording layer was then mixed by mixing following components.

Behenic acid (# 95 from Miyoshi Oil and Fat Co.) 0.8 parts CH ₃ (CH _{2) 17} -SO ₂ - (CH _{2) 2} -COOH 0.8 parts Vinyl chloride copolymer (MR110 from Nippon Zeon Co.) 4.2 parts tetrahydrofuran 25.7 parts o-xylene 4.5 parts Isocyanate Compound (Coronate 2298-90T from Nippon Polyurethane Industry Co.) 0.66 parts

The coating composition thus prepared was named Be layering on the before, as described above, structure te adhesive layer applied, with the underlying magneti layer together with the polyethylene terephthalate substrate, and was dried to a similar manner to Example 1 a heat sensitive layer having a thickness of about 11 microns crown. Further, a coating layer was added thereto a thickness of about 3 microns similar to Example 1 formed. Thus, the reversible thermosensitive recording medium was manufactured.  

COMPARATIVE EXAMPLE 3

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following formed the steps.

In a manner similar to Example 1, a Lichtreflexi onsschicht and an adhesive layer on the surface of the poly ethylene terephthalate film of the magnetic raw material roll (Memory Dick DS-1711-1040 from Dainippon Ink and Chemicals Inc) educated.

A coating composition for forming a heat temp The sensitive recording layer was then mixed by mixing following components.

Behenic acid (# 95 from Miyoshi Oil and Fat Co.) 0.5 parts Eicosanedioic acid (SL-20-99 from Okamure Oil Co.) 0.5 parts Vinyl chloride-vinyl acetate-vinyl alcohol copolymer (VAGH from Union Carbide Co.) 3 parts tetrahydrofuran 15.0 parts Isocyanate Compound (Coronate L from Nippon Polyurethane Industry Co.) 0.5 parts

The coating composition thus prepared was named Be layering on the before, as described above, structure te adhesive layer applied, with the underlying magneti layer together with the polyethylene terephthalate substrate, and was dried to a heat-sensitive layer with a thickness of about 11 microns, similar to the example 1. Further, similar to Example 1, a coating layer with a thickness of about 3 microns formed thereon. So that was it reversible, heat-sensitive recording medium produced.  

COMPARATIVE EXAMPLE 4

A reversible thermosensitive recording medium of The present invention has been made in accordance with the following made the steps.

Similar to Example 1, a light-reflecting layer and an adhesive layer on the surface of the polyethylene terephthalate lath foil of the roll of magnetic raw material (Memorydick DS- 1711-1040 by Dainippon Ink and Chemicals Inc).

A coating composition for forming a heat temp The sensitive recording layer was then mixed by mixing following components.

Behenic acid (# 95 from Miyoshi Oil and Fat Co.) 1.0 parts Vinyl chloride-vinyl acetate-vinyl alcohol copolymer (VAGH from Union Carbide Co.) 3.0 parts tetrahydrofuran 15.0 parts Isocyanate Compound (Coronate L from Nippon Polyurethane Industry Co.) 0.5 parts

The coating composition thus prepared was named Be layering on the before, as described above, structure applied adhesive layer, with the underlying magneti layer, together with the polyethylene terephthalate sub strat, and was dried to a heat-sensitive layer with a thickness of about 11 microns, similar to example 1 form. Furthermore, a coating layer with a Thickness of about 3 microns similar to Example 1 formed. Thus was the reversible thermosensitive recording medium provides.

The variety of reversible, heat-sensitive recording media, which in Examples 1, 4, 5, 6, 7, 8 and the Ver  Examples 1 to 4 were prepared, respectively Measurements were taken to determine characteristic parameters men. These parameters are the change in the elapsed on trapping temperature and the rate of change of trans parenztemperaturbreite.

Measuring conditions using a thermal gradient tester

Specimens of the white-opaque, reversible, heat-sensitive Recording medium were first by heating the medium Produced at temperatures that are high enough to whiten To achieve opaque state, as described earlier.

The thus prepared white-opaque samples were subsequently heated. The heating was carried out with a thermal gradient tester (HG-100, TOYO SEIKI Co.), with a heating time of 0.1 second and a pressure of 1 kg / cm ² . The temperature was increased in uniform increments of 2 ° C from 72 ° C to 165 ° C, where the transparency possibly started, or uniform steps of 5 ° C in the temperature range in which the transparency might end. The samples were then cooled to room temperature and subjected to optical density measurements using a MacBeth Reflection Densitometer RD-X914.

Another group of measurements were essentially for the white-opaque samples are performed in a similar way prepared above and left for one week at 35 ° C. These Samples were then the same heat treatment and same subjected to optical measurements as described above. From the Measurements at the respective temperatures became the change the delayed onset transparency temperature at the rate of Change in the transparency temperature width obtained.

The results from the measurements are shown in FIG. 14 for the results obtained from the measurements in Example 1. Similarly, the results are each in Fig. 15 for example 4, Fig. 16 for example 5 , Fig. 17 for example 6, Fig. 18 for example 7, Fig. 19 for example 8, Fig. 20 for example 9, Fig. 21 for example 10. Fig. 22 for Vergleichbei game 1, Fig. 23 for Comparative Example 2 and Fig. 24 for comparison example 3 Ver shown.

There are also the results of the change in the delayed än trapping temperature and the rate of change of trans parenztemperaturbreite listed in Table 5.

Furthermore, the lowermost and the uppermost transparency tempera and the transparency temperature width in a similar way obtained above.

Specifically, specimens of the white-opaque, reversible, heat-sensitive recording medium were first prepared by heating the medium to temperatures high enough to achieve the white-opaque state. The thus-prepared white-opaque samples were subsequently heated using the thermal gradient tester (HG-100, TOYO SEIKI Co.) with a heating time of 1 second and a pressure of 2.5 kg / cm ² . The temperature was increased in equal steps from 1 ° C to 5 ° C from a temperature high enough to maintain the white opaque state to a temperature high enough to provide satisfactory transparency. The samples were then cooled to room temperature and subjected to optical density measurements using a MacBeth Reflection Densitometer RD-914.

From the measurements at respective temperatures, a lowermost and an uppermost transparency temperature as well as the trans-parenztemperaturbreite were obtained, as shown in Fig. 6.

In addition, from the variety of reversible, wärmeemp sensitive recording media used in Examples 1, 4, 5,  6, 7, 8 and in Comparative Examples 1 to 4 Each measurement was subjected to erasability.

The measurements were made using a pressure tester performed by Yashiro Denki Co., with an edge heat Printhead EUX-ET8A9AS1 from Matsushita Electric Device Co. with equipped with a resistor of 1152 Ω.

Conditions of erasability measurement (I)

The printing conditions with the thermal print head were set to Im pulse width of 2.0 ms, a line duration of 2.86 ms, a Printing speed of 43.10 mm / s, a lateral scanning of 8 points / mm and a pressure roller pressure of 3 kp (kgf) set.

The transparent, reversible, heat-sensitive record media were then applied using various energy sources Gießengen by changing the applied voltage potential he which ranges from 0.176 to 0.527 mJ / dot to thereby To obtain energy values that were necessary to the jewei to bring saturated media to saturated white opaque density.

The results were 0.414 mJ / dot for the examples 1, 4, 5, 6, 8, 9 and 10 and 0.339 mJ / dot for Example 7 and Comparative Examples 1, 2, 3 and 4.

After white-opaque pictures with the above-mentioned printing energy were printed on the respective media were printing steps on the white-opaque image sections with the same Pressure conditions performed as above. During printing For example, the print energy values ranged from 0.09 to 0.363 mJ / point adjusted by changing the applied voltage potential provides, thereby eliminating the erasability for the respective media the respective energy values.  

After white-opaque pictures on the respective media with the The above-mentioned printing energy was printed Leave these media at 35 ° C for one week. The so vorbe rode media were under the same conditions as above prints, so that thereby the deletability for the respective Media after prolonged storage under respective energy values was achieved.

Conditions of erasability measurement (I)

To measure the erasability for a shorter printing time, wur carried out the additional measurements. The pressure conditions namely with the thermal print head were on a pulse width of 1.62 ms, a line duration of 1.8 ms, a printing speed of 69.44 mm / s, a lateral scanning density of 8 dots / mm and a pinch roller pressure of 3 kgf (kgf) is set.

Having white-opaque pictures under the above conditions on each Since media have been printed, printing has been printed on the white-opaque image sections performed, the Druckener values as a result of changes in the applied voltage potential al ranging from 0.084 to 0.297 mJ / dot. It became the Erasability for the respective media with corresponding energy greedy thus achieved.

After having white-opaque images on the respective media with the The above-mentioned printing energy printed these media leave at 35 ° C for one week. The prepared media were printed under the same conditions as above, and here the erasability of the respective media became apparent longer storage at the respective energy values achieved.

Table 7 lists the values given above Measurements obtained using the Gradientheizprüfgeräts were, like the average transparency density, the lowest trans density of parity, the highest density of transparency and the change in  the delayed transparency temperature; also the others, previously mentioned values resulting from the deletion under the Bedin tions (I) using the thermal print head wur wur such as the maximum initial quenching density and the delayed ma maximum extinction density.

Similarly, in Table 8, the above-mentioned values are listed from measurements using the gradient heating were obtained, such as the mean transparency density, the lowest transparency density, the highest transparency density and the delayed change in the transparency temperature; such as also the other, above-mentioned values, resulting from the deletion and under conditions (II) using the thermal print head were obtained, such as the maximum initial quenching density and the delayed maximum extinction density.

The results shown in Tables 5 to 8 clearly show to that, what the erasability using the heat pressure head with the conditions (I), the respective media in The examples each have a higher maximum extinction density aufwei sen as a dtm, both for the starting point and the delayed state of the media. This indicates that the Lö sufficiently completed.

In contrast, some of the media in the comparative examples a lower maximum extinction density than Dtm, indicating is that the erasability is not completely satisfactory. The Difference between the initial quenching density and the delayed one Erase density is higher in Example 5 than in others Examples, although the maximum extinction density of more than Dtm has resulted in the medium that delayed one Initial transparency temperature of -2.0 ° C than in Recording medium in Example 5.  

TABLE 5

Measured, dynamic transparency characteristics

* not measured or not transparent
(Gradientheizprüfgerät: 0.1 seconds and at a pressure of 1 kg / cm ² ),
T _tsd : dynamic initial _transparency temperature immediately after preparation of the medium
T _tsd ': dynamic initial _transparency temperature after prolonged storage of the meduim
dT _Wd : dynamic transparency temperature _width immediately after image formation
dT _Wd : dynamic transparency temperature _width after prolonged storage of the medium
dT _ts : delayed change of the initial transparency temperature
dT _W : Rate of change of transparency temperature width

TABLE 6

Transparency characteristics (Gradientheizprüfgerät: 1 second at a pressure of 2.5 kg / cm ² )

TABLE 7

Transparency characteristics and erasability using the thermal print head (Conditions I)

TABLE 8

Transparency characteristics and erasability using a thermal print head (Conditions II)

As can be seen from the above description, which also the Examples include the reversible, heat sensitive Auf Drawing medium of the invention improved erasability and improved image contrast, even within reduced Time of a printhead to be able to be more and more awake send data processing speed to match.

Moreover, the reversible, heat-sensitive recording medium of the present invention also be card-like, as a reversible thermosensitive recording label ver to be turned. This label may be on the surface of a Floppy disk case, a rewritable or disposable writable disk or disk, and a magnetic tape cassette be provided, being able to at least a part to view the information in the information store disk or disk or is stored on the magnetic tape.

This document claims priority and contains the In holds Japanese Patent Application 10-316542, issued to Japani Patent Office on 6 November 1998, whereby the entire contents incorporated herein by reference becomes.

Additional changes and adaptations of the herein disclosed Embodiments are possible in light of the above teaching, Des It should be noted half of these embodiments in the In light of the appended claims also be practiced otherwise can, as it is described in detail here.

In particular, the invention relates to a reversible, heat-sensitive recording medium with a heat-sensitive which is provided on a supporting substrate, the the transparency or hue reversible with the temperature changes, with the reversible, heat-sensitive recording medium, a change in the delayed initial transparency temperature temperature of not more than 5 ° C or a rate of change of transpa  temperature range of at least 90%. The mainstay Substrate comprises a matrix resin and a disperse in the matrix resin g., low molecular weight organic material, wherein the matrix resin is either a crosslinked mixture of a a hydroxyl group-containing thermoplastic resin, a a linear isocyanate compound and a cyclic isocyanate ver Bond or a crosslinked urethane resin based on polycarbonate includes. The supporting substrate of the recording medium can be card-like, as a reversible, heat-sensitive Recording label to be used. This label can on the surface of a floppy disk, a rewrite or write-once disk or disk and a Magnetic tape cassette be provided, and it is thereby in is able to display at least part of the information that in the information storage disk or disk or Mag netband are stored.

Claims (24)

1. Reversible thermosensitive recording medium, comprising:
a supporting substrate; and
a heat-sensitive layer provided on the substrate, wherein
the heat-sensitive layer changes the transparency or hue reversibly with the temperature,
characterized in that
the reversible thermosensitive recording medium has a change in the delayed initial transparency temperature of at most 5 ° C. 2. Reversible, heat-sensitive recording medium according to Claim 1, characterized in that the reversible, would be sensitive recording medium a change of the delayed Initial transparency temperature of at most 2 ° C. 3. Reversible, heat-sensitive recording medium according to Claim 1, characterized in that the reversible, would be me sensitive recording medium a rate of change of Transparency temperature width of at least 90%. 4. Reversible, heat-sensitive recording medium according to Claim 1, 2 or 3, characterized in that the rever sible, heat-sensitive recording medium is a change in the delayed initial transparency temperature of 5 ° C and max a rate of change of the transparency temperature width of at least 90%.   5. Reversible thermosensitive recording medium with:
a supporting substrate, and
a heat-sensitive layer provided on the supporting substrate and having, as main components, a matrix resin and a low molecular weight organic material dispersed in the matrix resin,
wherein the heat-sensitive layer reversibly changes the transparency or hue with temperature,
characterized in that
the matrix resin comprises a crosslinked mixture of a hydroxyl group-containing thermoplastic resin, a linear isocyanate compound and a cyclic isocyanate compound. 6. Reversible, heat-sensitive recording medium according to Claim 5, characterized in that the cyclic Isocy anat compound has a molecular weight of at least 250 be attracted to an isocyanate group. 7. Reversible thermosensitive recording medium with:
a supporting substrate, and
a heat-sensitive layer provided on the supporting substrate and having, as main components, a matrix resin and a low molecular weight organic material dispersed in the matrix resin,
wherein the heat-sensitive layer changes transparency or hue with temperature,
characterized in that
the matrix resin comprises a crosslinked polycarbonate-based urethane resin. 8. Reversible, heat-sensitive recording material according to Claim 5, 6 or 7, characterized in that the organi low molecular weight material is a mixture of at least one organic material with low Melting point and low molecular weight and at least an organic material with high melting point and low Molecular weight, wherein the difference of the enamel points between the organic material with low melting point  point and low molecular weight and the organic mate High Melting Point, Low Molecular Weight Min at least 30 ° C. 9. Reversible, heat-sensitive recording medium according to Claim 5, 6, 7 or 8, characterized in that the Ma trixharz a glass transition temperature of at least 40 ° C and at most 120 ° C. 10. Reversible, heat-sensitive recording medium according to Claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, characterized that the reversible thermosensitive recording medium is a having the highest transparency temperature of at least 125 ° C, where the difference between the highest transparency temperature and a lowest white-opaque temperature not exceeding 20 ° C and the transparency temperature width should be at least 30 ° C. 11. Reversible, heat-sensitive recording medium according to Claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, characterized gekenn characterized in that the low molecular weight organic material large is a mixture of at least one linear carbon hydrogen-containing compound having a melting point of at least 130 ° C, by an amide, urea or Sulfonylbindung and a carboxyl radical at least one or ei NEN, and at least one linear hydrocarbon containing compound having a melting point which is at least 30 ° C higher than that of the linea ren hydrocarbon containing compound. 12. Reversible, heat-sensitive recording medium according to Claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, further characterized draws through a layer of an adhesive or a pressure sensitive glue on the side of the supporting substrate is provided, that of the heat-sensitive recording layer opposed to being a reversible, heat-sensitive To form a recording label.   13. Reversible, heat-sensitive recording medium according to Claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, characterized records that the supporting substrate is card-like and further an information recording section. 14. Reversible, heat-sensitive recording medium according to Claim 12, characterized in that the substrate cardarten tiger and also an information recording section having. 15. Reversible, heat-sensitive recording medium according to Claim 13 or 14, characterized in that the Informa tion recording section of a magnetic Aufzeich layer, an integrated circuit (IC) and an op memory device has at least one. 16. Reversible, heat-sensitive recording medium according to Claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, characterized characterized in that the supporting substrate is one of a floppy disk or disk case in which a rewritable memory diskette or disk is housed, a wiederbe writable or write-once disk or disk and a magnetic tape cassette is. 17. A disk enclosure capable of displaying at least a portion of the information stored on a rewritable information storage label or disk;
full
the rewritable information storage disk or disk, and
a reversible thermosensitive recording label provided on at least one of the surfaces of the disk cartridge. 18. A rewritable information storage disk that displays at least a portion of the information stored in the rewritable information storage disk or disk,
full
the rewritable information storage disk or disk, and
a reversible thermosensitive recording label provided on at least one of the surfaces of the rewritable information storage disk or disk. 19. A magnetic tape cassette capable of displaying at least part of the information stored on a magnetic tape,
full
the magnetic tape cassette, and
a reversible thermosensitive recording label provided on at least one of the surfaces of the magnetic tape cassette. 20. Reversible, heat-sensitive recording medium according to Claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 and 19, further comprising a printed display section mounted on the reversible, heat-sensitive recording medium provided is. 21. A method of forming and erasing an image on a reversible thermosensitive recording medium, wherein the reversible thermosensitive recording medium is selected from the group consisting of:
a reversible thermosensitive recording medium having a thermosensitive layer provided on a supporting substrate, the thermosensitive layer reversibly changing its transparency or color tone with the temperature, and wherein the reversible recording medium exhibits a change in retarded transparency of at most 5 ° C having,
a reversible thermosensitive recording medium further contained in a reversible thermosensitive recording label further comprising a layer of an adhesive or a pressure-sensitive adhesive provided on the side of the supporting substrate which opposes the reversible thermosensitive recording layer is
a reversible thermosensitive recording medium further provided on at least one of the surfaces of a rewritable information storage disk or disk;
a reversible thermosensitive recording medium further provided on at least one of a surface of a disk or disk cartridge in which a rewritable information storage disk or disk is accommodated, and
a reversible thermosensitive recording medium, which is further provided on at least one of the surfaces of a magnetic tape cassette, and wherein
the process is carried out by heating. 22. Method for forming and erasing an image after An Claim 21, characterized in that the method with a Thermal print head is performed. 23. Method for forming and deleting an image after An Claim 21, characterized in that the method with a Thermal print head and in accordance with the Überreibme method is performed so that writing new pictures picturewise immediately after deleting the old pictures and using changing heating performance performed for each image becomes. 24. A method for forming and erasing an image as claimed 23, characterized in that the deletion with a kerami heating device is performed.