Heat-sensitive recording material

Patent metadata

Field	Value
Publication number	US-2025242626-A1
Application number	US-202318854259-A
Country	US
Kind code	A1
Filing date	Apr 6, 2023
Priority date	Apr 7, 2022
Publication date	Jul 31, 2025
Grant date	—

Abstract

Disclosed is a heat-sensitive recording material comprising at least an undercoat layer and a heat-sensitive recording layer in this order on a support,the undercoat layer containing an inorganic pigment, hollow particles, and a binder,the heat-sensitive recording layer containing a leuco dye, developers, and a binder,the heat-sensitive recording layer containing a first developer and a second developer as the developers,the heat-sensitive recording layer containing an N,N′-diarylurea-based compound represented by formula (1) as the second developer:whereinR2 represents a C1-12 alkyl group, a C7-12 aralkyl group, or a C6-12 aryl group, the aralkyl group and aryl group may be substituted with a C1-12 alkyl group, a C1-12 alkoxy group, a C6-12 aryl group, or a halogen atom, and a plurality of R2s may be the same or different; andA1 represents a hydrogen atom or a C1-4 alkyl group, and a plurality of A1s may be the same or different.

First claim

1 : A heat-sensitive recording material comprising at least an undercoat layer and a heat-sensitive recording layer in this order on a support,
the undercoat layer containing an inorganic pigment, hollow particles, and a binder, the heat-sensitive recording layer containing a leuco dye, developers, and a binder, the heat-sensitive recording layer containing a first developer and a second developer as the developers, and the heat-sensitive recording layer containing an N,N′-diarylurea-based compound represented by formula (1) as the second developer:

R 2 represents a C 1-12 alkyl group, a C 7-12 aralkyl group, or a C 6-12 aryl group, the aralkyl group and aryl group may be substituted with a C 1-12 alkyl group, a C 1-12 alkoxy group, a C 6-12 aryl group, or a halogen atom, and a plurality of R 2 s may be the same or different; and
A 1 represents a hydrogen atom or a C 1-4 alkyl group, and a plurality of A 1 s may be the same or different.

2 : The heat-sensitive recording material according to claim 1 , wherein the N,N′-diarylurea-based compound represented by formula (1) is at least one member selected from the group consisting of N,N′-di-[3-(p-toluenesulfonyloxy)phenyl]urea, N,N′-di-[3-(o-toluenesulfonyloxy)phenyl]urea, N,N′-di-[3-(benzenesulfonyloxy)phenyl]urea, N,N′-di-[3-(mesitylenesulfonyloxy)phenyl]urea, N,N′-di-[3-(4-ethylbenzenesulfonyloxy)phenyl]urea, N,N′-di-[3-(2-naphthalenesulfonyloxy)phenyl]urea, N,N′-di-[3-(p-methoxybenzenesulfonyloxy)phenyl]urea, N,N′-di-[3-(benzylsulfonyloxy)phenyl]urea, N,N′-di-[3-(ethanesulfonyloxy)phenyl]urea, N,N′-di-[3-(p-toluenesulfonyloxy)-4-methyl-phenyl]urea, N,N′-di-[4-(p-toluenesulfonyloxy)phenyl]urea, N,N′-di-[4-(benzenesulfonyloxy)phenyl]urea, N,N′-di-[4-(ethanesulfonyloxy)phenyl]urea, and N,N′-di-[2-(p-toluenesulfonyloxy)]phenylurea.

3 : The heat-sensitive recording material according to claim 1 , wherein the N,N′-diarylurea-based compound represented by formula (1) is N,N′-di-[3-(p-toluenesulfonyl)oxy]phenylurea.

4 : The heat-sensitive recording material according to claim 1 , wherein a diphenylsulfone derivative represented by formula (2) is contained as the first developer:

wherein
R 3 and R 4 are the same or different, and each represents C 1-4 alkyl group, a C 2-4 alkenyl group, a C 1-4 alkoxy group, a C 2-4 alkenyloxy group, a C 7-12 aralkyloxy group, or a halogen atom;
m is an integer of 0 to 2;
n is an integer of 1 to 3; and
p and q are the same or different, and each represents an integer of 0 to 2.

5 : The heat-sensitive recording material according to claim 4 , wherein the diphenylsulfone derivative represented by formula (2) is at least one member selected from the group consisting of 4-hydroxy-4′-isopropoxy diphenyl sulfone, 4,4′-dihydroxydiphenyl sulfone, 2,4′-dihydroxydiphenyl sulfone, bis(3-allyl-4-hydroxy)diphenyl sulfone, 4-hydroxyphenyl(4′-n-propoxyphenyl)sulfone, 4-allyloxy-4′-hydroxydiphenyl sulfone, and 4-hydroxy-4′-benzyloxydiphenyl sulfone.

6 : The heat-sensitive recording material according to claim 1 , wherein the first developer is N-p-tolylsulfonyl-N′-3-(p-tolylsulfonyloxy)phenylurea.

7 : The heat-sensitive recording material according to claim 1 , wherein the first developer is N-[2-(3-phenylureido)phenyl]benzenesulfonamide.

8 : The heat-sensitive recording material according to claim 1 , wherein the first developer is 5-(N-3-methylphenyl-sulfonamide)-N′,N″-bis-(3-methylphenyl)-isophthalic acid diamide.

9 : The heat-sensitive recording material according to claim 1 , wherein the second developer is contained in an amount of 0.1 to 3 parts by mass per part by mass of the first developer.

10 : The heat-sensitive recording material according to claim 1 , wherein the second developer is contained in an amount of 0.1 to 1 part by mass per part by mass of the first developer.

11 : The heat-sensitive recording material according to claim 1 , wherein
the hollow particles have a maximum particle diameter (D100) of 10 to 30 μm and an average particle diameter (D50) of 4.0 to 15 μm, the ratio of the maximum particle diameter (D100) to the average particle diameter (D50), which is D100/D50, is 1.8 to 3.0, and the volume % of hollow particles with a particle diameter of 2.0 μm or less is 1% or less.

12 : The heat-sensitive recording material according to claim 1 , wherein the hollow particles have a hollow ratio of 80 to 98%.

13 : The heat-sensitive recording material according to claim 1 , wherein the binder in the undercoat layer contains a binder resin with a glass transition temperature of −10° C. or lower.

14 : The heat-sensitive recording material according to claim 1 , wherein the binder in the undercoat layer contains a binder resin with a glass transition temperature of −30° C. or lower.

15 : The heat-sensitive recording material according to claim 1 , comprising an adhesive layer on at least one surface of the support.

Assignees

• Oji Holdings Corp

Inventors

• Takemura Takashi
• Sugiyama Naonobu

Classifications

• B41M2205/36

  Backcoats; Back layers · CPC title

• B41M2205/32

  Thermal receivers · CPC title

• B41M2205/04

  Direct thermal recording [DTR] · CPC title

• B41M5/42 Primary

  Intermediate, {backcoat}, or covering layers {(B41M5/405 takes precedence; multilayer thermal transfer systems in general B41M5/38214)} · CPC title

• B41M5/41

  Base layers {supports or substrates} · CPC title