Thermosensitive recording materials containing chelating agents

Patent metadata

Field	Value
Publication number	US-10118427-B2
Application number	US-201715448840-A
Country	US
Kind code	B2
Filing date	Mar 3, 2017
Priority date	Mar 17, 2016
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

The present invention relates to thermal recording materials comprising (in order):
a support (base) layer; one or more “undercoat” layers; a thermal layer (thermosensitive coloring layer); and
one or more “protective” layers, wherein the thermal recording material contains an aminocarboxylic and/or phosphorus-based chelating agent.

The thermal (thermosensitive) recording materials of the invention show enhanced plasticizer resistance and/or preprint uniformity.

First claim

The invention claimed is:

1. A thermal recording material comprising:
a base layer;
one or more undercoat layers which is/are laid down on the base layer;
a thermo-sensitive coloring layer which is laid down on the uppermost undercoat layer, on the opposite side with respect to the base layer; and
one or more protective layers which is/are laid down on the thermo-sensitive coloring layer, on the opposite side with respect to the undercoat layer(s),
wherein one or more of said protective layer(s) and/or said thermosensitive layer contains a chelating agent whose structure is given by following general formula (1):

wherein R1 is a linear alkyl group of 1 to 8 carbon atoms, optionally substituted with one or more carboxyl groups —CO2M, wherein M is hydrogen, ammonium or substituted ammonium, alkali metal, alkaline earth metal or a combination thereof.

2. The thermal recording material according to claim 1 , wherein the chelating agent is:
methylglycine diacetic acid (MGDA) or salts thereof, having R1=—CH3; or
glutamic diacetic acid (GLDA) or salts thereof, having R1=—(CH2)2-CO2M, where M is defined as in claim 1 .

3. The thermal recording material according to claim 1 , wherein one or more of the said undercoat layer(s) and/or the thermo-sensitive coloring layer and/or one or more of the said protective layer(s) further contains a phosphorus-based chelating agent.

4. A thermal recording material according to claim 1 , wherein the thermo-sensitive layer contains a leuco dye and a developer.

5. An image forming method including recording an image on the thermal recording material according to claim 1 using an image recording unit, which is any one of a thermal head and a laser.

6. A thermal recording material comprising:
a base layer;
one or more undercoat layers which is/are laid down on the base layer;
a thermo-sensitive coloring layer which is laid down on the uppermost undercoat layer, on the opposite side with respect to the base layer; and
one or more protective layers which is/are laid down on the thermo-sensitive coloring layer, on the opposite side with respect to the undercoat layer(s),
wherein one or more of the said undercoat layers contains an aminocarboxylic acid chelating agent.

7. The thermal recording material according to claim 6 , wherein the aminocarboxylic acid chelating agent contains —N—CH2-CH2-N— groups and/or —N—CH2-CO2M groups, wherein in —CO2M, M is hydrogen, ammonium or substituted ammonium, alkali metal, alkaline earth metal or a combination thereof.

8. The thermal recording material according to claim 7 , wherein the chelating agent whose structure is given by following general formula (1):

wherein R1 is a linear alkyl group of 1 to 8 carbon atoms, optionally substituted with one or more carboxyl groups —CO2M, wherein M is hydrogen, ammonium or substituted ammonium, alkali metal, alkaline earth metal or a combination thereof.

9. The thermal recording material according to claim 7 , wherein the chelating agent is:
methylglycine diacetic acid (MGDA) or salts thereof; or
glutamic diacetic acid (GLDA) or salts thereof.

10. The thermal recording material according to claim 7 , wherein the chelating agent is:
ethylendiamine tetraacetic acid (EDTA) or salts thereof; or
hydroxyethylendiamine triacetic acid (HEDTA) or salts thereof.

Assignees

• Daudin Laurence
• Gayrard Florence
• Iwata Daiki
• Ricoh Co Ltd

Inventors

• Daudin Laurence
• Gayrard Florence
• Iwata Daiki

Classifications

• B41M5/44

  characterised by the macromolecular compounds · CPC title

• B41M5/41 Primary

  Base layers {supports or substrates} · CPC title

• B41M5/323

  Organic colour formers, e.g. leuco dyes · CPC title

• B41M5/3375 Primary

  Non-macromolecular compounds · CPC title

• B41M2205/04

  Direct thermal recording [DTR] · CPC title