JPS58153687A - Heat-sensitive recording material - Google Patents

Abstract

PURPOSE:To provide the titled material which has an explicit picture, and is excellent in stability, resistance to chemical compound, and resistance to plasticizer, by a method wherein the material is consists of a first support having a thermal trnsfer layer at the back and a second support having an image receiving layer at the surface. CONSTITUTION:A paint liquid, consisting of mainly a colorless or light-colored leuco dye, i.e., 3-(N-methyl-N-cyclohexylamino)-6-methyl-7-anilinofuloran, and a heat fusible material, i.e., carnauba wax, is coated on the back of a support, a paint liquid consisting of mainly salicylate or metallic salt of oxinaphthol acid, i.e., 5-t-zinc octylsalicylate, is applied on the surface of the support, and the obtained supports are overlapped with each other with a coating surface in to provide a required material. Further, a first support surface is heated, and a transfer layer is transferred to a second support surface to form a picture.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-sensitive recording material that provides a transferred image by heating.

Thermal recording paper can easily develop color using heating means such as thermal heads, thermal pens, lasers, strobe flashes, and radiant heat from halogen lamps, and the market has rapidly expanded due to its ease of handling, which does not require a developing and fixing process. In addition to copying books and documents, they are now being used in a wide variety of applications, including computer terminal facsimile machines, recorder printers, and barcoder ticket vending machines.

Thermochromic compositions used in heat-sensitive recording materials generally consist of a color former and a color developer that causes the color former to develop color when heated. Examples of the color former include Ruff 7ton, lactam, or colorless material having a spiropyran ring. Alternatively, a light-colored leuco dye is used, and an acidic substance such as an organic acid or a phenolic substance is used as a color developer. This recording material that combines a color former and a color developer has the advantage that the resulting image has a clear color tone, a high background whiteness, and the image has excellent weather resistance, so it is widely used. Although it has been
It is also a well-known fact that chemical resistance and plasticizer resistance are poor. On the other hand, there are various transfer recording methods that use leuco dyes for transfer recording.For example, there are methods that use sublimation dyes and methods that transfer carbon ink, but methods that use sublimation dyes have problems with image durability. However, it is said that the method of transferring carbon ink still has drawbacks in terms of transferability, resolution, gloss, etc.

An object of the present invention is to provide a heat-sensitive recording material that has clear images, high stability, and good chemical resistance and plasticizer resistance.

To describe the present invention specifically, the heat-sensitive recording material of the present invention includes:
Consisting of a first support having a thermal transfer layer on the back surface and a second support having an image-receiving layer on the front surface, heating the surface of the first support and transferring the transfer layer to the surface J of the second support. In a thermal recording method for forming an image, the transfer layer usually contains a colorless or light-colored leuco dye and a thermofusible substance as main components, and the image-receiving layer mainly contains a metal salt of salicylic acids or oxynaphthoic acids. This is a heat-sensitive recording material characterized by being made of a material.

The colorless or light-colored leuco dye used in the present invention may be used alone or in combination as a coloring agent. Specific examples thereof include leuco dyes such as triphenylmethane, fluoran, phenothiazine, auramine, and spiropyran dyes.More detailed examples include the following.

3.3'-His(p-dimethylaminophenyl)-6-
Dimethylaminophthalide (also known as crystal violet), 3.3-bis(p-dimethylaminophenyl)phthalide, 3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophenyl, 3.3-bis( p-dimethylaminophenyl)-6-chlorophthalide, 3-(N-methyl-N-cyclohexyl)amino-6-
Methyl-7-anirite fluorane, 3-(N-p-1-tri-N-ethyl)amino-6-methyl-7-anirite fluorane, 3-di1-di, 6-methy/'-7
-Arifluorane, 3-diethylamino-7-chlorofluorane, benzoyl 6-icomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrillospirane, 6'-promo8'-methoxy-benzoindolino-pyrillospirane 1. Examples include 2-(3,6-bis(diethylamino)-9-(0-chloroanilino)xantylbenzoic acid lactam).

Examples of the thermofusible substance include organic low-molecular compounds, oligomers, and high-molecular compounds having an appropriate surface melting point or softening point. Specific examples include animal waxes, vegetable waxes, mineral waxes, petroleum waxes, and other synthetic waxes such as higher fatty acids, higher fatty amines, higher fatty acid amides, phenyl benzoate derivatives, crystalline alkylnaphthalenes, etc. Examples include crystalline alkyldiphenyl derivatives and alkylterphenyl derivatives.

On the other hand, examples of metal salt compounds of salicylic acids or oxynaphthoic acids used in image-receiving papers include those having the following general formula.

In the formula, R is a hydrogen atom or a substituent such as lower alkyl, higher alkyl, allyl, aralkyl, alkoxy, acyl, or halogen, and each R may be the same or different. Further, M is a divalent or trivalent metal, for example,
Zn, Sn, Oa, Mg, Ba.

Represents Ni, Co, A/, etc.

Specific examples of the metal salts include 3,5-ditertiary-butylsalicylic acid, 5-octylsalicylic acid, 5-coolsalicylic acid, 5-cyclohexylsalicylic acid, 5-benzylsalicylic acid, 5-chloro-3 -tert-butylsalicylic acid, 5-phenoxysalicylic acid, 2-oxy-3-naphthoic acid, 6,8-di-tert-butyl-2oxy-3-naphthoic acid,
1-oxy-2-naphthoic acid, 1-oxy-7-cucru 2-naphthoic acid, 2
-oxy-1-naphthoic acid, 2-oxy-3,6,8-
) is a metal salt such as ditertiarybutyl-1-naphthoic acid, and as metals, those that are generally not colored are preferable, and Ca, Ba, Mg, etc. are preferable, and in particular, Zn,
8n, ke are preferred.

The image-receiving layer may contain a pigment filler in order to improve the transferability or the apparent image density. Specific examples include clay, talc, aluminum hydroxide, magnesium hydroxide, zinc oxide, titanium oxide, calcium carbonate, silica, and carbon water. A support with good quality, such as a thin leaf containing fuglum, is used. The coating amount of the dye is preferably 0.1 ft-0.597 m'', and the preferable range of the heat-fusible material is 0.12 to 297 m''. Moreover, the preferable range of the color developer is 0.11 to 22.

Examples of the present invention are described below.

Example 1 The following coating liquid was applied to impregnated processed paper (thickness: 15 μm).

(Coating liquid) Carnauba wax (particle size 2μ) 20
Partial dispersing agent (surface active type) Part Isobutylene Maleic anhydride with alkali 5 parts Additive (binder) Water 11
The amount of dye deposited in the second part is 0 when applied with a wire bar.
It was designed to be 3 f 7 m2.

Next, coat high-quality paper with the following solution: inbutylene maleic anhydride 2 parts water 3
The amount of color developer attached was 0.8 parts by applying with a wiper.
The surface smoothness was adjusted to 300-400 seconds in Beck smoothness by calendering.

When two of the sheets obtained as described above were stacked one on top of the other and colored using a thermal gradient tester (manufactured by Toyo Seiki), a clear image was obtained on the receiving paper.

Example 2 A product was prepared in the same manner as in Example 1 except that 2-oxy-3-naphthoic acid was used instead of zinc 5-tert-octylsalicylate.

Example 3 A product was obtained in the same manner as in Example 1 except that magnesium 3,5-ditertiary-butylsalicylate was used instead of zinc 5-tertiary-octylsalicylate.

Comparative Example 1 The same procedure as in Example 1 was carried out except that bisphenol All was used instead of zinc 5-tertiary-octylsalicylate.

Next, each of the sheets obtained as described above was tested in the following manner.

(1) Fingerprint test After pressing a fingerprint on the image area and leaving it in a constant temperature bath at 60° C. for 3 days, judgment was made.

○: No change, ×: Image area peels off (2) Plasticizer test A thin layer of plasticizer (dioctyl phthalate (6op)) was applied to the image area, and changes were observed after leaving it for one day. .

○...No change in concentration, ×...Concentration almost disappeared (3
) Heat Resistance Tester Changes were observed after being left in a constant temperature bath at 0°C for 3 days.

○: Almost no change, Δ: The density decreases considerably Table 1 As can be seen from the above results, the image recording material of the present invention is not only capable of sufficient image recording; It can be seen that this is a much more reliable recording material than the comparative example.

Patent applicant Ricoh Co., Ltd. Agent: Patent Attorney Toshiaki Ikeura

Claims (1)

[Claims] (1) Consisting of a first support having a transfer layer on the back surface and a second support having an image receiving layer on the front surface, the surface of the first support is heated and the transfer layer is transferred to the surface of the second support. In a thermal recording method in which an image is formed by
1. A heat-sensitive recording material comprising a usually colorless or light-colored leuco dye and a thermofusible substance as main components, and an image-receiving layer comprising a metal salt of salicylic acids or oxynaphthoic acids as a main component.