JP3167448B2 - Reversible thermosensitive recording material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive recording material capable of repeatedly displaying and erasing a visible image.

[0002]

2. Description of the Related Art As a reversible thermosensitive recording material, a material in which an organic low-molecular compound is mixed and dispersed in a polymer resin base material has been proposed (JP-A-55-154198). This material has the property of becoming transparent when cooled to a normal temperature from a specific temperature range T ₁ and becoming cloudy when cooled to a normal temperature from a temperature range T ₂ higher than T _1. Can be reversibly printed and erased.

[0003]

However, this material The object of the invention is to solve the above-high since the range of the temperature range T ₁ showing the transmittance or very narrow or not high transparency, very difficult to control the temperature for the printing and erasing There was a problem that is.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above problems and provides a reversible thermosensitive recording material exhibiting characteristics opposite to those of the prior art.
In a polymer resin base material, A) at least one kind of a higher alkyl halide having 15 or more carbon atoms and B) at least one kind of an aliphatic saturated dicarboxylic acid having 12 or more carbon atoms are dispersed in combination. The reversible thermosensitive recording material is characterized in that the recording material is reversibly changed to an opaque state by cooling to a normal temperature from T _{1 and} to a transparent state by cooling to a normal temperature from a temperature T ₂ higher than the temperature T ₁ .

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a front view of an example of a card using the recording material of the present invention,
FIG. 2 is a ZZ cross-sectional view thereof.

The polymer resin base material in the present invention includes:
Any resin that is transparent and has good film-forming properties may be used.Polyvinyl chloride, vinyl chloride copolymers such as vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride, vinylidene chloride copolymer, polyester, polyamide, polystyrene, polymethyl (Meth) acrylate or a copolymer thereof is preferred.

The low-molecular organic compounds dispersed in the polymer resin base material include at least one of A) a higher alkyl halide having 15 or more carbon atoms and B) an aliphatic saturated dicarboxylic acid having 12 or more carbon atoms. Use with seeds.

[0008] The performance of these organic low molecular compounds may be varied transparency at the temperature range T ₁ and transparent to opaque by changing the mixing ratio, the opacity during opaque freely, printing, eraser The mixing ratio is set in consideration of the printing contrast and the like.

Although the conventional recording material has a higher opacity temperature than the clearing temperature, the combined use of the component A and the component B results in a recording material having a lower opacity temperature than the clearing temperature. Can be

As the alkyl halide of the component A, chlorides, bromides or iodides of alkyl having 15 or more carbon atoms, preferably 20 or more carbon atoms, such as 1-chlorodocosane, 1-bromodocosane, 1-chlorotriacontan, -Bromotriacontane, 1-iodohentriacontane and the like.

The B-component aliphatic saturated dicarboxylic acids having 12 or more carbon atoms include dodecandioic acid, tridecandioic acid, tetradecandiodic acid, pentadecandiodic acid, hexadecandiodic acid, octadecandioic acid, nonadecandioic acid, eicosanediacid. Acids, heneicosantioic acid, docosantioic acid, tricosandioic acid, tetrachosantioic acid, hexacosantioic acid, triacontanedioic acid, tetratriacontanedioic acid, and the like.

When the weight ratio of the component A to the component B is less than 2%, the composition does not become transparent even when heated, and when the ratio of the component B exceeds 70%, it is difficult to form a recording material layer. become.
The preferred weight ratio is in the range of 90:10 to 50:50 for A: B. The total amount of component A and component B is
10 to 80 parts by weight, preferably 30 to 6 parts by weight per 0 parts by weight
The range is 0 parts by weight.

When the recording material is heated to a temperature T ₂ by a heating means such as a thermal head, a heating stamp, a heating roll or the like, the recording material becomes transparent. Next, this transparent recording materials, thermal head, do it like in and locally heated to a temperature T ₁ of than T ₂ heated stamp, only the heated portion is opacified (cloudy), displaying a visible image can do. To erase the image, it may be heated to a temperature range T ₂ again.
Also, the white turbidity was recorded material, by heating the local temperature range T _2, it is also possible to perform clear printing during cloudy background.

The width of the opaque temperature range T ₁ is 5
If the temperature is lower than 60 ° C., it is difficult to control the temperature of the heating means such as a thermal head, so that it is difficult to obtain a stable opaque state.
When it more, too high a temperature T ₂ to be transparent, printing,
Although the thermal deterioration of the recording material due to repeated erasure is easy to progress, according to the present invention, for example, a temperature range of about 20 to 40 ° C. can be easily obtained.

FIGS. 1 and 2 show a card which is an example of the use of the recording material of the present invention. The card has a reflective layer 2 on a surface of a synthetic resin base sheet 1 such as polyethylene terephthalate (PET). A recording material layer 3, a protective layer 4, and a printing layer 5 for forming a visible recording display window 6 are laminated. A magnetic recording layer 7 and a protective layer 8 are provided on the back surface. The reflective layer 2 is for making the image formed on the recording material layer 3 easy to see, and is preferably a deposited layer or foil of aluminum, tin or the like, or a paint layer mixed with metal powder.

The protective layer 4 is for preventing thermal deterioration of the recording material layer 3, and is made of PET, polyetherimide, polyetheretherketone, polysulfone, polyphenylenesulfide, polyarylate, polyethersulfone, polycarbonate, polyethylenena. Phthalate,
A film or coating of a transparent resin having high heat resistance such as polyimide or acrylic resin can be used.

This card can be used, for example, as a prepaid card for entrance, shopping, rental, etc.
By displaying the amount of money used and the balance on the recording material layer 3 together with the magnetic recording at each use, an accurate balance can always be known. Further, it can be used as various heat-sensitive recording papers.

[0018]

【Example】

(Example 1) Aluminum was vapor-deposited as a reflective layer on the surface of a 188-μm-thick PET sheet in which a magnetic recording layer was previously formed to a thickness of 10 μm on the back surface. On top of this, a vinyl chloride-vinyl acetate copolymer (MRP-TS manufactured by Nissin Chemical Co., Ltd.) 1
1 part as the component A of the organic low molecular weight compound with respect to 00 parts by weight
-32 parts by weight of chlorodocosane, 1,12 as a B component
A recording material containing 16 parts by weight of tetradecandioic acid was dissolved in tetrahydrofuran, applied, dried, and dried to a thickness of 10
A μm recording material layer was formed.

On top of that, a PE having a thickness of 2 μm is formed as a protective layer.
A T-film was attached, and printing was performed to form a visible recording display window. On the other hand, a protective layer was provided on the magnetic recording layer on the back surface, and punched into a card shape. This recording material layer
It becomes opaque when cooled from 90 ° C. to room temperature, and becomes transparent when cooled from 130 ° C. to room temperature.

Example 2 A card was prepared in the same manner as in Example 1 except that 32 parts by weight of 1-bromodocosane was used instead of 1-chlorodocosane.

Comparative Example A card was prepared in the same manner as in the example except that only 32 parts by weight of 1-chlorodocosane as the component A was used as the organic low-molecular compound. Then, each of the obtained cards is heated at an interval of 50 ° C. to 1 ° C., and the reflection density of the recording material at each temperature is measured by a Macbeth reflection densitometer RD-91.
4 was measured.

When the measured value was 0.5 or less, the opaque state was set, and when 1.0 or more, the transparent state was set. The opaque temperature range T ₁ , its temperature range, and the clear temperature range T ₂ were determined. Table 1 shows the results.

[0023]

[Table 1]

It can be seen that the recording material of the present invention has a wide temperature range of the opacity temperature T ₁ , and a stable opaque state can be obtained even when the heating temperature fluctuates somewhat. Further, since a conventional one and opposite characteristics, the temperature width of the clearing temperature T ₂ is excellent in erasability widened to the high temperature side within a range that does not cause thermal degradation of the recording material. On the other hand, in the comparative example containing only the component A, printing was not possible because the composition was not transparent and was always in a cloudy state.

[0025]

The recording material of the present invention has a wide opacity temperature range, so that a stable opaque state can be obtained even when the heating temperature varies. In addition, since the characteristics are opposite to those of the conventional one, the temperature range of the clearing temperature is widened and the erasability is excellent.

Also, utilizing the opposite characteristic to the conventional one,
A recording method of performing transparent printing on cloudy ground is also possible, and is suitable for displaying, for example, a visible image that can be repeatedly printed and erased on a prepaid card or the like.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a card using the recording material of the present invention.

FIG. 2 is a sectional view taken along the line ZZ in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Card base material 2 Reflective layer 3 Recording material layer 4 Protective layer

Claims (1)

(57) [Claims] 1. A polymer resin matrix comprising: A) at least one higher alkyl halide having 15 or more carbon atoms; and B)
At least one kind of aliphatic saturated dicarboxylic acid having 12 or more carbon atoms is dispersed in combination, and is cooled to an ordinary temperature from the temperature T ₁ to be in an opaque state, and the temperature T is higher than the temperature T _1.
A reversible thermosensitive recording material characterized by reversibly changing to a transparent state by cooling from ₂ to room temperature.