Recording material and recording sheet

Abstract

A recording material and a recording sheet having better color-developing performance, storage stability, etc. A recording material which contains (A) at least one color former, (B) at least one compound selected from the group including compounds represented by the following formula (I), and (C) at least one compound selected from the group including compounds represented by the following formula (II) (wherein R.sup.1 to R.sup.3 each represent a halogen atom, a nitro group, a C.sub.1 to C.sub.6 alkyl group, a C.sub.1 to C.sub.6 alkoxy group, a C.sub.2 to C.sub.6 alkenyl group or a C.sub.1 to C.sub.6 haloalkyl group, n1 and n3 each independently represent any integer of 0 to 5, n2 represents any integer of 0 to 4, and X represents —SO.sub.2—O— or —O—SO.sub.2—). ##STR00001##

Claims

1. A recording material comprising (A) at least one color former, (B) at least one compound selected from the group consisting of compounds represented by the following formula (I): ##STR00009## and (C) at least one compound selected from the group consisting of compounds represented by the following formula (II): ##STR00010## wherein R.sup.1 to R.sup.3 each represent a halogen atom, a nitro group, a C.sub.1 to C.sub.6 alkyl group, a C.sub.1 to C.sub.6 alkoxy group, a C.sub.2 to C.sub.6 alkenyl group or a C.sub.1 to C.sub.6 haloalkyl group, n1 and n3 each independently represent any integer of 0 to 5, n2 represents any integer of 0 to 4, and X represents —SO.sub.2—O— or —O—SO.sub.2—, wherein the recording material does not comprise N-(2-(3-phenylureido)phenyl)benzenesulfonamide.

2. The recording material according to claim 1, wherein the compound represented by the above formula (I) is at least one compound selected from 4,4′-diaminodiphenyl sulfone and 3,3′-diaminodiphenyl sulfone.

3. The recording material according to claim 1, wherein the compound represented by the above formula (II) is a compound represented by the following formula (III): ##STR00011## wherein R.sup.1 and R.sup.3 are the same as R.sup.1 and R.sup.3 in formula (II).

4. The recording material according to claim 3, wherein the compound represented by the above formula (III) is N-(p-toluenesulfonyl)-N′-(3-p-toluenesulfonyloxyphenyl)urea.

5. The recording material according to claim 1, wherein the color former is a fluoran-based dye.

6. A recording sheet having a recording material layer formed from the recording material according to claim 1 on a support.

Description

EXAMPLES

(1) Now, the recording material of the present invention will be more specifically described by way of Examples; however, the present invention is not limited merely to these.

Preparation and Test of Thermal Recording Paper

1) Preparation of Thermal Recording Paper

Example 1

(2) TABLE-US-00001 Dye dispersion solution (Solution A) 3-di-n-Butylamino-6-methyl-7-anilinofluoran 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts Color-developing agent dispersion solution (Solution B) PF-201 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts Filler dispersion solution (Solution C) Calcium carbonate 27.8 parts 10% Aqueous polyvinyl alcohol solution 26.2 parts Water 71 parts Additive dispersion solution (Solution D1) 3,3′-diaminodiphenyl sulfone 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts (“parts” represents “parts by mass”)

(3) Each mixture having the composition of the solutions A to D1 was sufficiently ground with a sand grinder to prepare dispersion solutions of the components of the solutions A to D1.

(4) 1 part by mass of the solution A, 2 parts by mass of the solution B, 3 parts by mass of the solution C, and 1 part by mass of the solution D1 were mixed to prepare a coating solution for a color developing layer. Subsequently, the coating solution for a color developing layer was applied on the white paper-sheet by use of a wire rod and dried, and then calendering treatment was applied to prepare a thermal recording paper (the coating solution for a color developing layer: about 5.5 g/m.sup.2 on a dry-mass basis).

Example 2

(5) TABLE-US-00002 Additive dispersion solution (Solution D2) 4,4′-diaminodiphenyl sulfone 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts (“parts” represents “parts by mass”)

(6) A thermal recording paper was prepared in the same manner as in Example 1 except that 1 part by mass of the solution D1 was replaced by 1 part by mass of the solution D2.

Comparative Example 1

(7) TABLE-US-00003 Sensitizer dispersion solution (Solution E) EGPE 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts (“parts” represents “parts by mass”)

(8) A thermal recording paper was prepared in the same manner as in Example 1 except that 1 part by mass of the solution D1 was replaced by 1 part by mass of the solution E.

2) Image Storage Stability Test

(9) With respect to individual evaluation samples, the colored images were subjected to a storage stability test in the following conditions. The results were shown in Table 1.

(10) [Before Test]

(11) Each thermal recording paper was partly cut out and color was developed by use of a thermo-sensitive paper color development test machine (trade name: TH-PMH type, manufactured by OHKURA-DENKI) at a printing voltage of 17 V and a pulse width of 1.8 ms. The density of colored image was measured by a spectrophotometer (SpectroeyeLT, manufactured by X-Rite, Inc.).

(12) [Heat Resistance Test]

(13) Each thermal recording paper was partly cut out and saturated color development was carried out in the same manner as before the test. The paper sample was stored in an incubator (trade name: DK-400, manufactured by YAMATO) of 80° C., 90° C. or 100° C. for 24 hours. After the test, the optical density thereof was measured by a spectrophotometer (SpectroeyeLT, manufactured by X-Rite, Inc.).

(14) [Plasticizer Resistance Test]

(15) Each thermal recording paper was partly cut out and saturated color development was carried out in the same manner as before the test. Subsequently, a vinyl-chloride wrap film (one including a plasticizer) was allowed to adhere to the color developing side and the back side of each paper sample and stored as they were at 40° C. for four hours. Thereafter, the density of colored image was measured by a spectrophotometer (SpectroeyeLT, manufactured by X-Rite, Inc.).

(16) [Oil Resistance Test]

(17) Each thermal recording paper was partly cut out and saturated color development was carried out in the same manner as before the test. Subsequently, the paper was immersed in salad oil, and the density of colored image after one hour at room temperature was measured by a spectrophotometer (SpectroeyeLT, manufactured by X-Rite, Inc.).

(18) TABLE-US-00004 TABLE 1 Evaluation Before Heat resistance Plasticizer Oil sample test 90° C. 100° C. resistance resistance Example 1 1.37 1.35 1.24 1.15 1.38 Example 2 1.38 1.30 1.24 1.20 1.32 Comparative 1.31 1.15 0.98 1.01 1.18 Example 1

(19) From the results of Table 1, it was found that a combination with 3,3′-diaminodiphenyl sulfone or 4,4′-diaminodiphenyl sulfone provided excellent storage stability of colored images.