Claims
- 1. A pressure-sensitive recording material capable of forming an image upon color development due to the reaction of an electron-donating color former and an electron-accepting color developer, wherein the color developer comprises a mixture of (a) a metal salt of an aromatic carboxylic acid and (b) a hindered phenol which is a phenol having an alkyl substitutent in at least one of the positions 2 and 6 or is a derivative thereof and which contains a plurality of phenolic hydroxyl groups wherein the proportion of the hindered phenol compound in the color developer comprising a mixture of the aromatic carboxylic acid metal salt and the hindered phenol compound is in the range of 5 to 60% by weight, wherein the aromatic carboxylic acid used is represented by the following formula (I): ##STR3## wherein R.sub.1 and R.sub.2, which may be the same or different, each represents an alkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms or an aralkyl group having 7 to 15 carbon atoms.
- 2. The pressure-sensitive recording material as claimed in claim 1, wherein said aromatic carboxylic acid has a hydroxyl group in the ortho or para position to the carboxyl group.
- 3. The pressure-sensitive recording material as claimed in claim 2, wherein said aromatic carboxylic acid is a salicylic acid derivative having at least one substituent selected from the group consisting of an alkyl group, an aryl group or an aralkyl group, in the ortho and/or para position to the hydroxyl group, with the sum of the carbon atoms in the substituents being not less than 8.
- 4. The pressure-sensitive recording material as claimed in claim 1, wherein the metal constituting said metal salt is selected from the group consisting of magnesium, aluminum, calcium, scandium, titanium, vanadium, chromium, maganese, iron, cobalt, nickel, copper, zinc, potassium, germanium, strontium, yttrium, zirconium, molybdenum, cadmium, indium, antimony, barium and tin.
- 5. The pressure-sensitive recording material as claimed in claim 1, wherein said hindered phenol has a tert-butyl group in at least one of the positions 2 and 6 or is a derivative thereof.
- 6. The pressure-sensitive recording material as claimed in claim 1, wherein the proportion of the hindered phenol in the aromatic carboxylic metal acid salt-hindered phenol mixture is in the range of from 10 to 40% by weight.
- 7. The pressure-sensitive recording material claimed in claim 1, wherein the carboxylic acid used is represented by the formula (I) and wherein R.sub.1 and R.sub.2, which may be the same or different, each represents a t-butyl group, a t-amyl group, a t-hexyl group, a .alpha.,.alpha.-dimethyl-benzyl group or a .alpha.-methylbenzyl group.
- 8. The pressure-sensitive recording materials claimed in claim 4, wherein the metal constituting said metal salt is selected form the group consisting of zinc, aluminum and calcium.
- 9. The pressure-sensitive recording material claimed in claim 8, wherein the metal constituting said metal salt is zinc.
- 10. The pressure-sensitive recording material claimed in claim 1, wherein the hindered phenol is represented by the formulae (II) or (III): ##STR4## wherein R.sub.3 represents a t-butyl group, a methyl group, an ethyl group or a hydrogen atom; R.sub.4 represents a hydrogen atom, a methyl group or an ethyl group, and X represents a sulfur atom or a alkylene group.
- 11. The pressure-sensitive recording material claimed in claim 1, wherein the color former is selected from the group consisting essentially of triarylmethane type compounds, diphenylmethane type compounds, xanthene type compounds, thiazine type compounds, spiro type compounds, and mixtures thereof.
- 12. The pressure-sensitive recording material claimed in claim 1, wherein the color former is coated in an amount of about 0.01 to 0.2 g/m.sup.2.
- 13. The pressure-sensitive recording material claimed in claim 12, wherein the color former is coated in an amount of 0.03 to 0.1 g/m.sup.2.
- 14. The pressure-sensitive recording material claimed in claim 10, wherein the metal constituting said metal salt is selected from the group consisting of magnesium, aluminum, calcium, scandium, titanium, vanadium, chromium, maganese, iron, cobalt, nickel, copper, zinc, potassium, germanium, strontium, yttrium, zirconium, molybdemum, cadmium, indium, tin, antimony, and barium.
- 15. The pressure-sensitive recording material claimed in claim 14, wherein the color former is coated in an amount of about 0.01 to 0.2 g/m.sup.2.
- 16. The pressure-sensitive recording material claimed in claim 15, wherein the carboxylic acid used is represented by the formula (I) and wherein R.sub.1 and R.sub.2, which may be the same or different, each represents a t-butyl group, a t-amyl group, a t-hexyl group, an .alpha.-dimethylbenzyl group or an .alpha.-methyl benzyl group.
- 17. The pressure-sensitive recording material claimed in claim 15, wherein the aromatic carboxylic acid of the metal salt of an aromatic carboxylic acid is selected from the group consisting of 3,5-di-tert-butylsalicylic acid, 3,5-di-tert amylsalicylic acid, 3,5-bis(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 3,5-bis(.alpha.-methylbenzyl)salicylic acid, 3-(.alpha.-methylbenzyl)-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid, 3,5-di-tert-octylsalicylic acid and 3-cyclohexyl-5-(.alpha.,.alpha.-dimethylbenzyl)salicylic acid.
- 18. The pressure-sensitive recording material claimed in claim 17, wherein the hindered phenol has two or three phenolic hydroxyl groups.
- 19. The pressure-sensitive recording material claimed in claim 18, wherein said hindered phenol has a tert-butyl group in at least one of the two or six positions.
Priority Claims (1)
Number |
Date |
Country |
Kind |
58-215815 |
Nov 1983 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 672,319 filed Nov. 16, 1984.
US Referenced Citations (8)
Continuations (1)
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Number |
Date |
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Parent |
672319 |
Nov 1984 |
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