Recording material and recording sheet

Abstract

An object of the invention is to provide a recording material and recording sheet having excellent color-developing performance, storage stability, etc. A recording material having good color-developing performance and storage stability may be obtained by using a specific compound having a benzhydrol skeleton as an additive in a recording material employing color development through a reaction between a color former and a color-developing agent.

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 (X): ##STR00025## (wherein X and Y each independently 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, a C.sub.1 to C.sub.6 haloalkyl group or a C.sub.2 to C.sub.6 haloalkenyl group; and p and q each independently represent any integer of 0 to 5), and (C) a color-developing agent, which is at least one compound selected from the group consisting of a compound represented by the following formula (II): ##STR00026## (wherein R.sub.1 and R.sub.2 each independently represent a halogen atom, a C.sub.1 to C.sub.6 alkyl group optionally having a substituent, a C.sub.2 to C.sub.6 alkenyl group optionally having a substituent, or an arylsulfonyl group optionally having a substituent; n1 represents any integer of 0 to 4; n2 represents 1 or 2 (with the proviso that n1+n2 is any integer of 1 to 5); n3 represents any integer of 0 to 5; n4 represents 0 or 1 (with the proviso that n3+n4 is any integer of 0 to 5); and R.sub.3 is a hydrogen atom, a C.sub.1 to C.sub.6 alkyl group optionally having a substituent, a C.sub.2 to C.sub.6 alkenyl group optionally having a substituent, an aralkyl group optionally having a substituent or an arylsulfonyl group optionally having a substituent), a compound represented by the following formula (III): ##STR00027## (wherein R.sub.5 to R.sub.7 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 fluoroalkyl group, an N(R.sub.8).sub.2 group (wherein R.sub.8 represents a hydrogen atom, a phenyl group, a benzyl group, or a C.sub.1 to C.sub.6 alkyl group), NHCOR.sub.9 (wherein R.sub.9 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; n5 and n7 each independently represent any integer of 1 to 5; and n6 represents any integer of 1 to 4), a compound represented by the following formula (IV): ##STR00028## (wherein R.sub.5 to R.sub.7 are the same as R.sub.5 to R.sub.7 in formula (III); n6 and n7 are the same as n6 and n7 in formula (III); and n8 represents any integer of 1 to 7), a compound represented by the following formula (V): ##STR00029## (wherein R.sub.5 to R.sub.7 are the same as R.sub.5 to R.sub.7 in formula (III); and n6, n7, and n8 are the same as n6, n7, and n8 in formula (IV)), a compound represented by the following formula (VI): ##STR00030## (wherein R.sub.10 and R.sub.11 each independently represent a C.sub.1 to C.sub.6 alkyl group; and n9 and n10 each independently represent any integer of 0 to 5), and a compound represented by the following formula (VII): ##STR00031## (wherein D represents a linear, branched or cyclic C.sub.1 to C.sub.12 hydrocarbon group or a group represented by the following formula (VIII) or formula (IX): ##STR00032## (wherein R represents a methylene group or an ethylene group, and T represents a hydrogen atom or a C.sub.1 to C.sub.4 alkyl group); m1 represents any integer of 1 to 6; R.sub.4 each independently represent a halogen atom, a C.sub.1 to C.sub.6 alkyl group, or a C.sub.2 to C.sub.6 alkenyl group; n11 each independently represent any integer of 0 to 4; m2 represents any integer of 1 to 6; and R.sub.1, R.sub.2, n1, n2, and n3 represent the same as R.sub.1, R.sub.2, n1, n2, and n3 in formula (II)).

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

3. A recording sheet having a recording material layer formed from the recording material according to claim 2 on a support.

4. 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.

(2) Note that, as calcined kaolin, Ansilex (registered trade mark)-93 was used. With respect to the compounds, the names or structures of which are shown below, the following abbreviations are used.

(3) 1,1-Diphenylethanol, abbreviation: DPE

(4) 2-Methylbenzhydrol, abbreviation: MBH

(5) 1,2-bis(phenoxy)ethane, abbreviation: EGPE

(6) 4-Hydroxy-4-isopropoxydiphenyl sulfone, abbreviation: D-8

(7) 4,4-Dihydroxydiphenyl sulfone, abbreviation: 4,4-BPS

(8) ##STR00022##

(9) (wherein b is any integer of 1 to 6)

(10) A mixture of diphenyl sulfone crosslinked compounds represented by above formula, abbreviation: D-90

(11) ##STR00023##
Abbreviation: color developing agent 1

(12) ##STR00024##

(13) Abbreviation: P-201

(14) Preparation and Test of Thermal Recording Paper

(15) 1) Preparation of Thermal Recording Paper

Examples 1 to 10, Comparative Examples 2, 4, 6, 8, 10

(16) Dye Dispersion Solution (Solution A)

(17) TABLE-US-00001 3-di-n-Butylamino-6-methyl-7-anilinofluoran 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts
Color-Developing Agent Dispersion Solution (Solution B)

(18) TABLE-US-00002 Color-developing agent 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts
Filler Dispersion Solution (Solution C)

(19) TABLE-US-00003 Calcined kaolin 27.8 parts 10% Aqueous polyvinyl alcohol solution 26.2 parts Water 71 parts
Sensitizer Dispersion Solution (Solution D)

(20) TABLE-US-00004 Sensitizer 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts (parts represents parts by mass)

(21) 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. 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. To a white paper-sheet, first, 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 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 Examples 1, 3, 5, 7, 9

(22) Dye Dispersion Solution (Solution A)

(23) TABLE-US-00005 3-di-n-Butylamino-6-methyl-7-anilinofluoran 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts
Color-Developing Agent Dispersion Solution (Solution B)

(24) TABLE-US-00006 Color-developing agent 16 parts 10% Aqueous polyvinyl alcohol solution 84 parts
Filler Dispersion Solution (Solution C)

(25) TABLE-US-00007 Calcined kaolin 27.8 parts 10% Aqueous polyvinyl alcohol solution 26.2 parts Water 71 parts (parts represents parts by mass)

(26) Each mixture having the composition of the solutions A to C was sufficiently ground with a sand grinder to prepare dispersion solutions of the components of the solutions A to C. 1 part by mass of the solution A, 2 parts by mass of the solution B and 4 parts by mass of the solution C were mixed to prepare a coating solution for a color developing layer. To a white paper-sheet, first, 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 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).

(27) The (correspondence) relationship between evaluation samples, color-developing agent and sensitizer is shown in Table 1.

(28) In the following tests, Comparative Examples were carried out for comparing each of two types of sensitizers used in Examples.

(29) TABLE-US-00008 TABLE 1 List of evaluation samples Color-developing Evaluation sample agent Sensitizer Comparative Color-developing Example 1 agent 1 Comparative Color-developing EGPE Example 2 agent 1 Example 1 Color-developing DPE agent 1 Example 2 Color-developing MBH agent 1 Comparative D-8 Example 3 Comparative D-8 EGPE Example 4 Example 3 D-8 DPE Example 4 D-8 MBH Comparative D-90 Example 5 Comparative D-90 EGPE Example 6 Example 5 D-90 DPE Example 6 D-90 MBH Comparative P-201 Example 7 Comparative P-201 EGPE Example 8 Example 7 P-201 DPE Example 8 P-201 MBH Comparative 4,4-BPS Example 9 Comparative 4,4-BPS EGPE Example 10 Example 9 4,4-BPS DPE Example 10 4,4-BPS MBH

(30) 2) Dynamic Color-Developing Sensitivity Test

(31) Each thermal recording paper was partly cut out and subjected to a dynamic color-developing sensitivity test using a thermo-sensitive paper color development test machine (trade name: TH-PMH type, manufactured by OHKURA-DENKI). Color was developed in both conditions: printing voltage of 17 V, pulse widths of 0.95 ms and 1.25 ms and then the print densities were measured by Macbeth reflection densitometer (filter used herein: #106).

(32) The results of the above test are shown in Tables 2-1 and 2-2.

(33) TABLE-US-00009 TABLE 2-1 Dynamic color-developing Evaluation sensitivity sample 0.95 ms 1.25 ms Comparative 0.67 1.10 Example 1 Comparative 1.19 1.27 Example 2 Example 1 1.19 1.28 Comparative 1.01 1.25 Example 3 Comparative 1.27 1.28 Example 4 Example 3 1.23 1.28 Comparative 0.52 0.89 Example 5 Comparative 0.96 1.15 Example 6 Example 5 0.94 1.13 Comparative 0.66 1.09 Example 7 Comparative 1.19 1.26 Example 8 Example 7 1.18 1.29 Comparative 0.63 1.05 Example 9 Comparative 1.10 1.29 Example 10 Example 9 1.09 1.30

(34) TABLE-US-00010 TABLE 2-2 Dynamic color-developing Evaluation sensitivity sample 0.95 ms 1.25 ms Comparative 0.41 0.84 Example 1 Comparative 0.94 1.24 Example 2 Example 2 0.89 1.20 Comparative 0.76 1.14 Example 3 Comparative 1.16 1.31 Example 4 Example 4 1.10 1.26 Comparative 0.28 0.60 Example 5 Comparative 0.65 0.97 Example 6 Example 6 0.68 0.94 Comparative 0.41 0.86 Example 7 Comparative 1.00 1.24 Example 8 Example 8 0.94 1.22 Comparative 0.35 0.72 Example 9 Comparative 0.62 1.07 Example 10 Example 10 0.78 1.15

(35) From the results of Tables 2-1 and 2-2, it was found that the recording sheet of the present invention produces an equivalent sensitization effect compared to the case where EGPE was used as a sensitizer, and that particularly in the case where 4,4-BPS is used as a color-developing agent, MBH exerts a further more excellent sensitization effect than EGPE.

(36) 3) Storage Stability Test for Background

(37) 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 3-1 and 3-2.

(38) [Before Test]

(39) Each thermal recording paper was partly cut out and optical density of the background was measured by a Macbeth reflection densitometer (filter used herein: #106).

(40) [Heat Resistance Test]

(41) Each thermal recording paper was partly cut out and stored in an incubator (trade name: DK-400, manufactured by YAMATO) of 80 C., 90 C. or 100 C. for 24 hours. After storage, the optical density of the background was measured by a Macbeth reflection densitometer (filter used herein: #106).

(42) [Water Resistance Test]

(43) Each thermal recording paper was partly cut out and soaked in water at 25 C. for 7 days. Thereafter, the optical density of the background was measured by a Macbeth reflection densitometer (filter used herein: #106).

(44) TABLE-US-00011 TABLE 3-1 Evaluation Before Background heat resistance Background sample test 80 C. 90 C. 100 C. water resistance Comparative 0.06 0.08 0.11 0.12 0.04 Example 1 Comparative 0.04 0.12 0.18 0.24 0.03 Example 2 Example 1 0.05 0.13 0.15 0.15 0.03 Comparative 0.06 0.14 0.20 0.32 0.03 Example 3 Comparative 0.07 0.27 0.52 0.70 0.02 Example 4 Example 3 0.08 0.30 0.30 0.39 0.02 Comparative 0.05 0.07 0.21 0.45 0.05 Example 5 Comparative 0.04 0.16 0.36 0.65 0.04 Example 6 Example 5 0.05 0.29 0.31 0.44 0.05 Comparative 0.08 0.12 0.16 0.21 0.05 Example 7 Comparative 0.07 0.20 0.32 0.36 0.03 Example 8 Example 7 0.07 0.18 0.21 0.21 0.04 Comparative 0.10 0.13 0.18 0.19 0.02 Example 9 Comparative 0.09 0.16 0.21 0.27 0.02 Example 10 Example 9 0.08 0.15 0.18 0.21 0.02

(45) TABLE-US-00012 TABLE 3-2 Evaluation Before Background heat resistance Background sample test 80 C. 90 C. 100 C. water resistance Comparative 0.06 0.06 0.07 0.08 0.05 Example 1 Comparative 0.05 0.09 0.14 0.25 0.04 Example 2 Example 2 0.06 0.11 0.15 0.19 0.04 Comparative 0.06 0.10 0.14 0.29 0.04 Example 3 Comparative 0.06 0.24 0.55 0.80 0.04 Example 4 Example 4 0.08 0.38 0.45 0.76 0.04 Comparative 0.04 0.05 0.13 0.41 0.05 Example 5 Comparative 0.04 0.12 0.29 0.65 0.05 Example 6 Example 6 0.05 0.31 0.40 0.59 0.05 Comparative 0.06 0.09 0.12 0.22 0.05 Example 7 Comparative 0.06 0.24 0.37 0.45 0.04 Example 8 Example 8 0.07 0.25 0.38 0.39 0.04 Comparative 0.11 0.09 0.08 0.11 0.03 Example 9 Comparative 0.09 0.10 0.14 0.21 0.03 Example 10 Example 10 0.08 0.14 0.16 0.21 0.03

(46) From Tables 3-1 and 3-2, it is found that the recording sheet of the present invention did not develop color before the test and thus no fogging occurred in the background and had better background heat-resistance compared to the case where EGPE was used as a sensitizer. The background water resistance was equivalent compared to the case where EGPE was used as a sensitizer.

(47) 4) Image Storage Stability Test

(48) 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 4-1 and 4-2.

(49) [Before Test]

(50) 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 Macbeth reflection densitometer (filter used herein: #106).

(51) [Heat Resistance Test]

(52) 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 Macbeth reflection densitometer (filter used herein: #106).

(53) [Water Resistance Test]

(54) 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 soaked in water at 25 C. for 7 days. Thereafter, the optical density thereof was measured by a Macbeth reflection densitometer (filter used: #106).

(55) TABLE-US-00013 TABLE 4-1 Evaluation Before Image heat resistance Image water sample test 80 C. 90 C. 100 C. resistance Comparative 1.27 1.29 1.23 0.86 1.02 Example 1 Comparative 1.25 1.04 1.01 0.78 0.48 Example 2 Example 1 1.28 1.27 1.22 0.85 1.10 Comparative 1.31 1.04 1.00 0.97 0.97 Example 3 Comparative 1.23 0.95 0.93 0.91 0.43 Example 4 Example 3 1.22 1.01 0.97 0.92 0.73 Comparative 1.09 1.08 1.12 1.06 1.00 Example 5 Comparative 1.17 1.03 0.97 0.89 0.97 Example 6 Example 5 1.18 1.14 1.13 1.05 1.01 Comparative 1.24 1.28 1.18 0.83 0.88 Example 7 Comparative 1.26 1.01 0.95 0.71 0.57 Example 8 Example 7 1.28 1.20 1.12 0.77 0.90 Comparative 1.28 1.28 1.29 1.18 0.88 Example 9 Comparative 1.30 1.31 1.23 1.20 0.67 Example 10 Example 9 1.33 1.34 1.35 1.28 0.96

(56) TABLE-US-00014 TABLE 4-2 Evaluation Before Image heat resistance Image water sample test 80 C. 90 C. 100 C. resistance Comparative 1.21 1.24 1.21 1.13 0.92 Example 1 Comparative 1.28 1.29 1.27 1.14 0.62 Example 2 Example 2 1.27 1.28 1.27 1.13 1.04 Comparative 1.28 1.33 1.32 1.30 0.91 Example 3 Comparative 1.30 1.29 1.28 1.25 0.45 Example 4 Example 4 1.29 1.30 1.28 1.26 0.88 Comparative 0.92 0.96 1.03 1.05 0.83 Example 5 Comparative 1.10 1.08 1.07 1.03 0.90 Example 6 Example 6 1.09 1.06 1.07 1.03 0.92 Comparative 1.20 1.25 1.21 1.05 0.85 Example 7 Comparative 1.27 1.26 1.21 1.04 0.68 Example 8 Example 8 1.26 1.25 1.20 1.02 0.88 Comparative 1.16 1.17 1.15 1.10 0.80 Example 9 Comparative 1.25 1.27 1.28 1.26 0.83 Example 10 Example 10 1.24 1.29 1.28 1.25 0.95

(57) From Tables 4-1 and Table 4-2, it was found that the recording sheet of the present invention has equivalent image heat resistance compared to the case where EGPE was used as a sensitizer. In the case where EGPE was used, water resistance was poor depending upon the color-developing agent used in combination; however, the recording sheet of the present invention was found to exert excellent water resistance even though any type of color-developing agent is used.