JPS62225392A - Thermal plastic thin film recording material - Google Patents

Abstract

PURPOSE:To obtain the heat reversible recording material capable of forming the picture having the large contrast of a transparent state to a turbid state, high brightness and efficient durability, by providing at least one kind of specific compound capable of keeping a transparent state or a turbid state on a base material according to different thermal temperature. CONSTITUTION:At least one kind of the compound indicated by the general formula (1) capable of keeping a transparent state or a turbid state according to different temperature is provided on the base material of heat reversible thin film recording material. The compound of the general formula (1) is dissolved with solvent and applied to the base material to form a thin film. Though the transparent thin film does not change its transparency at a room temperature state, if the thin film material is warmed by a specific hot plate at approx. 50 deg.C-120 deg.C, it starts to be turbid. After returning it to room temperature, it is stable and the white picture part and the transparent non-picture part of good contrast are formed. If the white picture part is warmed by the hot plate of a high temperature at approx. 100-160 deg.C (generally a temperature near a fusing point), it returns to the initial transparent state. Even though it is cooled to room temperature, the transparent state is stably kept. Further, this is the durable thermal reversible thin film material capable of repeating the operation, having the large contrast of a transparent state to a turbid state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a thermoplastic thin film recording material that can assume a transparent state and an opaque state at different thermal temperatures.

[Prior art]

Many materials that undergo plastic changes due to heat or light have been known for a long time, and are generally very useful as photochromic or thermochromic materials.

Typical materials that undergo plastic changes due to heat include those that use leuco dyes to change color tone through repeated melting and solidification, and laser recording materials that use solidification by melting a total refractive mixture. However, transparent materials made of polymeric compounds or fatty acids mixed into polymeric compounds,
Composite materials that repeat opacity are also available.

However, conventionally known polymer compounds or polymer compounds kneaded with fatty acids have the disadvantage that the whiteness of the opaque state is not sufficient, and the durability is not sufficient, making it difficult to record repeatedly over a long period of time. If you do this, it will deteriorate,
There was a drawback that whiteness decreased.

〔the purpose〕

An object of the present invention is to provide a new thermoplastic recording material that can form images with a large contrast between transparent and opaque states, high whiteness, and excellent durability.

〔composition〕

According to the present invention, there is provided a thermoplastic thin film recording material in which at least one compound represented by the following general formula (1) which can take a transparent state or an opaque state depending on different thermal temperatures is provided on a support. .

General formula (wherein R□ and R2 represent a lower alkyl group, a substituted or unsubstituted aryl group, or an aralkyl group) Specific examples of the general formula compound (I) include (1)
N,N'-dicyclohexyl-N,N'-dimethylisophthalamide (2) N,N'-dicyclohexyl-N,N'-
Diethylisophthalamide (3) N,N'-dicyclohexyl-N,N'-
Di-n-propylisophthalamide (4) N,N'-dicyclohexyl-N,N'-
Di-isopropylisophthalamide (5) N,N'-dicyclohexyl-N,N'-di-
Benzyl isophthalamide (6) N,N'-dicyclohexyl-N,N'-
Examples include, but are not limited to, di(IIl-methylbenzyl)isophthalamide and the like.

In the present invention, the compound of the general formula (1) is used.

For example, it is dissolved in an appropriate solvent and applied onto a support such as paper or plastic to form a thin film. The formed transparent thin film is stable at room temperature and its transparency hardly changes even after one month;
When heat is applied with a specific hot plate at ~120°C, opacity occurs, which remains stable even after returning to room temperature, forming a white image area and a transparent non-image area with good contrast. In addition, when this white image is formed by applying heat with a hot plate with a higher concentration of 100 to 160°C (generally at a temperature near the melting point), it returns to the initial transparent state, and even if it is cooled to room temperature, the transparent state remains. Stability is maintained. Furthermore, even if the above operations are repeated, the formation of a white image and the initial transparency are repeated at the same time, so that the recording medium of the present invention has a large contrast between transparent and opaque states fi, and is called a sufficiently durable thermoplastic thin film body. be able to.

Next, FIG. 1 shows a measurement chart of the general formula compound (1) using a differential scanning calorimeter (Shimadzu differential calorimeter DT-30 system).

That is, as shown in FIG. 1, for example, N.

When a white crystalline powder of N'-dicyclohexyl-N,N'-dimethylisophthalamide is heated at a rate of 10°/sin, a heat of fusion absorption peak is observed in the range of 153 to 155°C. When the sample is naturally cooled to room temperature and repeated measurements are performed, an exothermic peak of crystallization is observed at around 100° C. At this time, the sample changes from a transparent state to an opaque state. When the temperature is further increased, the sample melts in the range of 153 to 156°C, as in the first time, and the sample becomes transparent.

Similar exothermic peaks and endothermic peaks are observed even if repeated measurements are performed. Therefore, since the thermoplastic thin film recording material of the present invention has the above-mentioned properties, 011
P film, second original film, electronic blackboard, optical sensor
, it can be used for optical memory as a laser recording material, etc.

In addition, in the present invention, in addition to the compound of general formula (1), if necessary, auxiliary additive components 1 commonly used in this type of heat-sensitive recording material, such as fillers, surfactants, lubricants, etc., may be used in combination. be able to. In this case, the filler is
For example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate,
In addition to inorganic fine powders such as clay, talc, surface-treated calcium and silica, organic fine powders such as urea-formalin resin, styrene/methacrylic acid copolymer, and polystyrene resin can be used as lubricants. is 1. For example,
In addition to higher fatty acids or their esters, amides, or metal salts, various waxes, condensates of aromatic carboxylic acids and amines, phenyl benzoate, higher linear glycols, dialkyl 3,4-epoxy-hexahydrophthalates , higher ketones, other thermofusible organic compounds, etc.
Examples include those having a melting point of about 200°C.

Further, as the binder resin agent, the following are used.

Polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, ethylcellulose, sodium polyacrylate,
Polyvinyl pyro 1-nodone, acrylic amide/acrylic ester copolymer, acrylic amide/acrylic ester/methacrylic acid ternary copolymer, styrene/maleic anhydride copolymer alkali salt, isobutylene/maleic anhydride copolymer In addition to water-soluble polymers such as combined alkali salts, polyacrylamide, sodium alginate, gelatin, and casein, polyvinyl acetate, polyurethane, styrene/butadiene copolymer, polyacrylic acid, polyacrylic acid ester, and vinyl chloride/vinyl acetate copolymer Polymer, polybutyl methacrylate-1-.

Latex such as ethylene/vinyl acetate copolymer, styrene/butadiene/acrylic copolymer, etc.

The heat-sensitive recording material of the present invention can be prepared, for example, by applying a thin film-forming coating solution containing the compound of general formula (1) and each of the above-mentioned auxiliary components onto a suitable support such as paper, synthetic paper, or plastic film. It is manufactured by coating and drying.

The amount of coating varies depending on the purpose of use, but is usually 0. 'rg/rd to 10g/bo is appropriate.

〔effect〕

The thermoplastic thin film recording material of the present invention has a large contrast between transparent and opaque states and a high degree of whiteness by containing the compound represented by the general formula (I) that repeatedly appears in different phase states depending on different temperatures. , and can form an image with excellent durability. Therefore, the thermoplastic thin film recording material of the present invention has 0! IP film, 2nd
Original drawing fill 1%.

It can be used for electronic blackboards, optical sensors, optical memories as laser recording materials, etc.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 [Synthesis of N,N'-dicyclohexyl-N,N'-dimethylisophthalamide] 23.8 g of N-methyl-N-cyclohexylamine and 12 g of sodium hydroxide, 200 cc of water, and 10 g of toluene
Add to 0 cc of the mixed solution and dissolve. A solution prepared by dissolving 20.3 g of isophthaloyl dichloride in 50 cc of toluene is added dropwise to this mixed solution over a period of 1 hour at 10° C. or lower. Thereafter, the mixture was cooled to room temperature and stirred for an additional hour. The obtained precipitate was filtered, washed with water, dried, and recrystallized from 95% ethanol.
, N'-dicyclohexyl-N,N'-dimethylisophthalamide (35.0 g) was obtained. Melting point 15
4-1556C0 [Preparation of thermoplastic thin film recording material] N,N'-dicyclohexyl-N,N' obtained above
- 10 g of dimethyl isophthalamide is dissolved in 200 mQ of tetrahydrofuran (TIIF), and 0.5 g of modified ethylene-vinyl acetate copolymer resin is added and completely dissolved.

Next, this liquid was applied onto a 20 μm transparent heat-resistant polyester using a doctor blade so that the dry solid content was 2 g/m to prepare a thermoplastic thin film recording medium of the present invention.

This recording material was transparent like polyester. When this recording medium was brought into contact with a hot plate at 85°C for 1 second,
It became white and opaque. This product was stable even when returned to room temperature, and no change in its state was observed over time. This white image area has a transmittance of 5% or less (500 nm) and a gloss level of 5% or less, and the transparent area has a transmittance of 80% or more (500 nm).
500 nm), the glossiness was 20% or more.

Next, a hot plate at 160°C was applied to the white image area of the recording medium for 1 s.
When brought into contact with EC, it became transparent, and the transparent state was maintained even when the temperature was returned to room temperature. Even after repeating the above operation several times, similar results were obtained.

[Brief explanation of drawings]

FIG. 1 is a measurement chart when five compounds targeted by the present invention were measured using a differential scanning calorimeter.

Claims (1)

[Claims] (1) A thermoplastic thin film recording material comprising, on a support, at least one compound represented by the following general formula (I) that can change into a transparent state or an opaque state depending on different temperatures. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1 and R_2 represent a lower alkyl group, a substituted or unsubstituted aryl group, or an aralkyl group.)