RECORDING MATERIAL AND RECORDING SHEET

Abstract

A recording material and a recording sheet having excellent color-developing performance and storage stability and particularly having excellent heat-resistance of background. The recording material contains a color former (A), a compound represented by formula (I) (B), and a compound represented by formula (II) (C).

##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): ##STR00013## and (C) at least one compound selected from the group consisting of compounds represented by the following formula (II): ##STR00014## (wherein R and R represent a hydrogen atom, 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, a C.sub.1 to C.sub.6 haloalkyl group, an N(R.sup.4).sub.2 group (wherein R.sup.4 represents a hydrogen atom, a phenyl group, a benzyl group, or a C.sub.1 to C.sub.6 alkyl group), AR.sup.5 (wherein A represents a group represented by SO.sub.2NH, NHSO.sub.2, CONH, or NHCO, and R.sup.5 represents a C.sub.1 to C.sub.6 alkyl group optionally having a substituent, a phenyl group optionally having a substituent, a 1-naphthyl group optionally having a substituent, or a 2-naphthyl group optionally having a substituent), a phenyl group optionally having a substituent, or a benzyl group optionally having a substituent, n and n each independently represent any integer of 1 to 5, and X represents O or S).

2. The recording material according to claim 1, wherein the compound represented by the formula (II) is at least one compound selected from the group consisting of: a compound represented by the following formula (III): ##STR00015## (wherein R.sup.1 to R.sup.3 represent a hydrogen atom, 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, a C.sub.1 to C.sub.6 haloalkyl group, an N(R.sup.4).sub.2 group (wherein R.sup.4 represents a hydrogen atom, a phenyl group, a benzyl group, or a C.sub.1 to C.sub.6 alkyl group), NHCOR.sup.6 (wherein R.sup.6 represents a C.sub.1 to C.sub.6 alkyl group), a phenyl group optionally having a substituent, or a benzyl group optionally having a substituent, n1 and n3 each independently represent any integer of 1 to 5, n2 represents any integer of 1 to 4, A.sup.1 represents a group represented by SO.sub.2NH, NHSO.sub.2, CONH, or NHCO, and X is the same as X in formula (II)), a compound represented by the following formula (IV): ##STR00016## (wherein R.sup.1 to R.sup.3 are the same as R.sup.1 to R.sup.3 in formula (III), n2 and n3 are the same as n2 and n3 in formula (III), n4 represents any integer of 1 to 7, A.sup.1 is the same as A.sup.1 in formula (III), and X is the same as X in formula (II)), and a compound represented by the following formula (V): ##STR00017## (wherein R.sup.1 to R.sup.3 are the same as R.sup.1 to R.sup.3 in formula (III), n2, n3, and n4 are the same as n2, n3, and n4 in formula (IV), A.sup.1 is the same as A.sup.1 in formula (III), and X is the same as X in formula (II)).

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

4. The recording material according to claim 2 wherein A.sup.1 is SO.sub.2NH and X is O in a compound represented by the above formula (III), formula (IV), or formula (V).

5. The recording material according to claim 2, wherein the compound represented by the above formula (III) is a compound represented by the following formula (VI): ##STR00018## (wherein R.sup.1 to R.sup.3 and n1 to n3 are the same as R.sup.1 to R.sup.3 and n1 to n3 in formula (III)).

6. The recording material according to claim 5, wherein the compound represented by the above formula (VI) is N-(2-(3-phenylureido)phenyl)benzenesulfonamide.

7. The recording material according to claim 6, wherein N-(2-(3-phenylureido)phenyl)benzenesulfonamide is in a crystalline form showing peaks at diffraction angles (20.10) of 23.60, 20.80, 12.24, and 13.80 in powder X-ray diffractometry using Cu-K rays.

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

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

Description

EXAMPLES

[0113] 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 1-1

[0114]

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) N-(2-(3-phenylureido)phenyl)benzenesulfonamide 16 parts type II crystal 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 D) 4,4-diaminodiphenyl sulfone 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts (parts represents parts by mass)

[0115] Each mixture having the composition of the solutions A to D was sufficiently ground with a sand grinder to prepare dispersion solutions of the components of the solutions A to D.

[0116] 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 D 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).

Comparative Example 1-1

[0117] By use of dispersion solutions of the components of the same solutions A to C as those in Example 1-1, 1 part by mass of the solution A, 3 parts by mass of the solution B, and 3 parts by mass of the solution C were mixed to prepare a coating solution for a color developing layer. The coating solution for a color developing layer was applied on a white paper-sheet and dried, and then calendering treatment was applied in the same manner as in Example 1-1 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).

Comparative Example 1-2

[0118] By use of dispersion solutions of the components of the same solutions A, C, and D as those in Example 1-1, 1 part by mass of the solution A, 3 parts by mass of the solution C, and 3 parts by mass of the solution D were mixed to prepare a coating solution for a color developing layer. The coating solution for a color developing layer was applied on a white paper-sheet and dried, and then calendering treatment was applied in the same manner as in Example 1-1 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 2-1

[0119] By use of dispersion solutions having the composition of the same solutions A to D as those in Example 1-1, 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 D were mixed to prepare a coating solution for a color developing layer. On a white paper-sheet, first, the solution C was applied by use of a wire rod (wire bar NO. 12, manufactured by Webster) and dried to prepare an undercoat layer. Subsequently, the coating solution for a color developing layer was applied on the undercoat layer and dried, and then calendering treatment was applied in the same manner as in Example 1-1 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 2-2

[0120]

TABLE-US-00002 Color-developing agent dispersion solution (Solution B) N-(2-(3-phenylureido)phenyl)benzenesulfonamide 16 parts type I crystal 10% Aqueous polyvinyl alcohol solution 84 parts (parts represents parts by mass)

[0121] A mixture having the composition of the solution B was sufficiently ground with a sand grinder to prepare a dispersion solution of the components of the solution B.

[0122] By use of dispersion solutions of the components of the same solutions A, C, and D as those in Example 1-1 and the above solution B, 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 D were mixed to prepare a coating solution for a color developing layer.

[0123] An undercoat layer was prepared on a white paper-sheet, subsequently, the coating solution for a color developing layer was applied on the undercoat layer and dried, and then calendering treatment was applied in the same manner as in Example 2-1 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 2-3

[0124] By use of dispersion solutions having the composition of the same solutions A to D as those in Example 2-1, 1 part by mass of the solution A, 1.8 parts by mass of the solution B, 4 parts by mass of the solution C, and 0.2 part by mass of the solution D were mixed to prepare a coating solution for a color developing layer. An undercoat layer was prepared on a white paper-sheet, subsequently, the coating solution for a color developing layer was applied on the undercoat layer and dried, and then calendering treatment was applied in the same manner as in Example 2-1 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 2-4

[0125] By use of dispersion solutions of the components of the same solutions A, B, C, and D as those in Example 2-2, 1 part by mass of the solution A, 1.8 parts by mass of the solution B, 4 parts by mass of the solution C, and 0.2 part by mass of the solution D were mixed to prepare a coating solution for a color developing layer. An undercoat layer was prepared on a white paper-sheet, subsequently, the coating solution for a color developing layer was applied on the undercoat layer and dried, and then calendering treatment was applied in the same manner as in Example 2-1 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 3-1

[0126] A coating solution for a color developing layer was prepared, an undercoat layer was prepared, subsequently, the coating solution for a color developing layer was applied and dried, and then calendering treatment was applied in the same manner as in Example 2-3 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 3-2

[0127] A coating solution for a color developing layer was prepared, an undercoat layer was prepared, subsequently, the coating solution for a color developing layer was applied and dried, and then calendering treatment was applied in the same manner as in Example 2-4 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 3-3

[0128]

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

[0129] A mixture having the composition of the solution E was sufficiently ground with a sand grinder to prepare a dispersion solution of the components of the solution E.

[0130] By use of dispersion solutions of the components of the same solutions A to D as in Example 1-1 and the above solution E, 1 part by mass of the solution A, 1.8 parts by mass of the solution B, 4 parts by mass of the solution C, 0.2 parts by mass of the solution D, and 1 part by mass of the solution E were mixed to prepare a coating solution for a color developing layer. An undercoat layer was prepared on a white paper-sheet, subsequently, the coating solution for a color developing layer was applied on the undercoat layer and dried, and then calendering treatment was applied in the same manner as in Example 2-1 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 3-4

[0131] By use of dispersion solutions of the components of the same solutions A, B, C, and D as those in Example 2-2 and the same solution E as that in Example 3-3, 1 part by mass of the solution A, 1.8 parts by mass of the solution B, 4 parts by mass of the solution C, 0.2 parts by mass of the solution D, and 1 part by mass of the solution E were mixed to prepare a coating solution for a color developing layer. An undercoat layer was prepared on a white paper-sheet, subsequently, the coating solution for a color developing layer was applied on the undercoat layer and dried, and then calendering treatment was applied in the same manner as in Example 2-1 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 3-5

[0132] By use of dispersion solutions of the components of the same solutions A to D as those in Example 1-1 and the same solution E as that in Example 3-3, 1 part by mass of the solution A, 1.7 parts by mass of the solution B, 4 parts by mass of the solution C, 0.3 parts by mass of the solution D, and 1 part by mass of the solution E were mixed to prepare a coating solution for a color developing layer. An undercoat layer was prepared on a white paper-sheet, subsequently, the coating solution for a color developing layer was applied on the undercoat layer and dried, and then calendering treatment was applied in the same manner as in Example 2-1 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 3-6

[0133] By use of dispersion solutions of the components of the same solutions A to D as those in Example 1-1 and the same solution E as that in Example 3-3, 1 part by mass of the solution A, 1.6 parts by mass of the solution B, 4 parts by mass of the solution C, 0.4 parts by mass of the solution D, and 1 part by mass of the solution E were mixed to prepare a coating solution for a color developing layer. An undercoat layer was prepared on a white paper-sheet, subsequently, the coating solution for a color developing layer was applied on the undercoat layer and dried, and then calendering treatment was applied in the same manner as in Example 2-1 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 3-7

[0134] By use of dispersion solutions of the components of the same solutions A to D as those in Example 1-1 and the same solution E as that in Example 3-3, 1 part by mass of the solution A, 1.5 parts by mass of the solution B, 4 parts by mass of the solution C, 0.5 parts by mass of the solution D, and 1 part by mass of the solution E were mixed to prepare a coating solution for a color developing layer. An undercoat layer was prepared on a white paper-sheet, subsequently, the coating solution for a color developing layer was applied on the undercoat layer and dried, and then calendering treatment was applied in the same manner as in Example 2-1 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).

[0135] The relationship of the evaluation samples with the color-developing agent, the presence or absence of 4,4-diaminodiphenyl sulfone as an additive, sensitizer, mass ratio thereof contained, and the presence or absence of the undercoat layer is shown in Table 1.

TABLE-US-00004 TABLE 1 List of evaluation samples Mass ratio of components Color- contained (color Evaluation developing former:color-developing Undercoat sample agent Additive Sensitizer agent:additive:sensitizer) layer Example 1-1 Crystal + 1:2:1:0 form II Comparative Crystal 1:3:0:0 Example 1-1 form II Comparative + 1:0:3:0 Example 1-2 Example 2-1 Crystal + 1:2:1:0 + form II Example 2-2 Crystal + 1:2:1:0 + form I Example 2-3 Crystal + 1:1.8:0.2:0 + form II Example 2-4 Crystal + 1:1.8:0.2:0 + form I Example 3-1 Crystal + 1:1.8:0.2:0 + form II Example 3-2 Crystal + 1:1.8:0.2:0 + form I Example 3-3 Crystal + EGPE 1:1.8:0.2:1 + form II Example 34 Crystal + EGPE 1:1.8:0.2:1 + form I Example 3-5 Crystal + EGPE 1:1.7:0.3:1 + form II Example 3-6 Crystal + EGPE 1:1.6:0.4:1 + form II Example 3-7 Crystal + EGPE 1:1.5:0.5:1 + form II

[0136] 2) Storage Stability Test for Background

[0137] With respect to individual evaluation samples, the test sheets before and after the test were subjected to a storage stability test in the following conditions. The results were shown in Tables 2-1 and 2-2.

[0138] [Before Test]

[0139] Each thermal recording paper was partly cut out and optical density of the background was measured by a spectrophotometer (SpectroeyeLT, manufactured by X-Rite, Inc.).

[0140] [Heat Resistance Test]

[0141] Each thermal recording paper was partly cut out and stored in an incubator (trade name: DK-400, manufactured by YAMATO) of 90 C. or 100 C. for 24 hours. After storage, the optical density of the background was measured by a spectrophotometer (SpectroeyeLT, manufactured by X-Rite, Inc.).

[Moist-Heat Resistance Test]

[0142] Each thermal recording paper was partly cut out and stored in a constant low temperature/humidity chamber (trade name: THN050FA, manufactured by ADVANTEC) under conditions of a temperature of 40 C. and a humidity of 90% for 24 hours. Thereafter, the optical density thereof was measured by a spectrophotometer (SpectroeyeLT, manufactured by X-Rite, Inc.).

TABLE-US-00005 TABLE 2-1 Background evaluation Moist-heat Evaluation Before Heat resistance resistance sample test 90 C. 100 C. 40 C., 90% RH Example 2-1 0.02 0.05 0.08 0.02 Example 2-2 0.03 0.07 0.13 0.03 Example 2-3 0.03 0.05 0.08 0.02 Example 2-4 0.03 0.06 0.12 0.03

TABLE-US-00006 TABLE 2-2 Background evaluation Moist-heat Evaluation Before Heat resistance resistance sample test 90 C. 100 C. 40 C., 90% RH Example 3-1 0.03 0.05 0.08 0.02 Example 3-2 0.03 0.06 0.12 0.03 Example 3-3 0.02 0.14 0.26 0.01 Example 3-4 0.02 0.24 0.37 0.02 Example 3-5 0.02 0.17 0.25 0.01 Example 3-6 0.02 0.19 0.26 0.01 Example 3-7 0.02 0.18 0.25 0.01

[0143] From the results of Tables 2-1 and 2-2, it was found that the recording sheet of the present invention has excellent background heat resistance and moist-heat resistance and that the heat resistance is good and falls within a range with no practical problem particularly even when a sensitizer is used in combination.

[0144] 3) Image storage stability test

[0145] 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 Tables 3-1 to 3-3.

[0146] [Before Test]

[0147] 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.).

[0148] [Heat Resistance Test]

[0149] 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.).

[0150] [Moist-Heat Resistance Test]

[0151] 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 stored in a constant low temperature/humidity chamber (trade name: THN050FA, manufactured by ADVANTEC) under conditions of a temperature of 40 C. and a humidity of 90% for 24 hours. Thereafter, the optical density thereof was measured by a spectrophotometer (SpectroeyeLT, manufactured by X-Rite, Inc.).

[Plasticizer Resistance Test]

[0152] 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.).

[Oil Resistance Test]

[0153] 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.).

TABLE-US-00007 TABLE 3-1 Image evaluation Moist-heat resistance Evaluation Before Heat resistance 40 C., Plasticizer Oil sample test 90 C. 100 C. 90% RH resistance resistance Example 1.13 1.17 1.14 1.16 0.64 0.50 1-1 Compar- 1.15 1.10 1.01 1.13 0.26 0.12 ative Example 1-1 Compar- 0.40 0.12 0.12 0.14 0.09 0.15 ative Example 1-2

TABLE-US-00008 TABLE 3-2 Image evaluation Moist-heat resistance Evaluation Before Heat resistance 40 C., Plasticizer Oil sample test 90 C. 100 C. 90% RH resistance resistance Example 1.34 1.28 1.10 1.36 0.82 1.02 2-1 Example 1.33 1.28 1.11 1.36 0.85 0.98 2-2 Example 1.32 1.27 1.02 1.34 0.55 0.16 2-3 Example 1.31 1.27 1.03 1.33 0.58 0.16 2-4

TABLE-US-00009 TABLE 3-3 Image evaluation Moist-heat resistance Evaluation Before Heat resistance 40 C., Plasticizer Oil sample test 90 C. 100 C. 90% RH resistance resistance Example 1.32 1.27 1.02 1.34 0.55 0.16 3-1 Example 1.31 1.27 1.03 1.33 0.58 0.16 3-2 Example 1.28 1.15 0.97 1.32 0.51 0.18 3-3 Example 1.29 1.14 0.97 1.31 0.58 0.17 3-4 Example 1.29 1.17 1.00 1.33 0.45 0.25 3-5 Example 1.29 1.14 1.00 1.33 0.47 0.34 3-6 Example 1.29 1.15 0.97 1.33 0.52 0.41 3-7

[0154] From the results of Tables 3-1 to 3-3, it was found that the use of 4,4-diaminodiphenyl sulfone singly was not practical, although a slight color developing ability was seen, and particularly the image storage stability was inferior. However, it was also found that when 4,4-diaminodiphenyl sulfone was used in combination with N-(2-(3-phenylureido)phenyl)benzenesulfonamide, the plasticizer resistance and oil resistance of colored images were markedly improved and also the heat resistance was improved, in comparison with the case where N-(2-(3-phenylureido)phenyl)benzenesulfonamide was used as the color-developing agent and 4,4-diaminodiphenyl sulfone was not added and combined. Even when the sensitizer was used, the image storage stability remained good.