JPS6025275B2 - heat sensitive recording material - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a V heat-sensitive recording material, and more particularly to a heat-sensitive recording material containing a novel lactone compound as a coloring agent. As is well known, the thermal recording method, which uses physical or chemical changes in substances caused by thermal energy to obtain images, can be used not only for copying documents, but also for recording the output of electronic computers, etc. It is expected that the technology will continue to be used to record facsimile reception in the future, as research is underway to develop a coloring system that does not emit noise during recording and does not require development or fixing. Many types of recording materials have been proposed to date for use in this V-thermal recording method, but among them, recording materials that use koiko bodies such as fluoran dyes as coloring agents have a high color development rate against heat. In other words, it has recently attracted attention because of its excellent thermal sensitivity. However, thermal recording paper that uses the leuco form of fluorane dyes as a coloring agent, which is attracting attention, has
It has the disadvantage that it easily develops color due to pressure, and furthermore, that it also develops color due to the presence of an organic solvent such as alcohol. An object of the present invention is to use a heat-sensitive recording material for use in the above-mentioned heat-sensitive recording method, to obtain a black image with strong light resistance, and to easily develop color under pressure or in the presence of an organic solvent such as alcohol. The goal is to provide products that do not have the disadvantages of That is, the present invention provides the following methods: general formula [wherein R is a hydrogen atom, a lower alkyl group, a benzyl group (
It can have a halogen atom or a lower alkyl group as a substituent. ), and R2 represents a lower alkyl group, a cyclohexyl group, a benzyl group (which can have a halogen atom or a lower alkyl group as a substituent), or a phenyl group (which can have a halogen atom or a lower alkyl group as a substituent). )
or R, and R2 are combined to form -(C)4-
, 1 (C mountain) 5 1, 1 (CH2) 2 10 - (C ratio) -, R3 and R4 represent a hydrogen atom, a lower alkyl group, an aralkyl group, an amyl group, a phenyl group (however, R3 and At least one of R4 is a hydrogen atom),
R5 represents a hydrogen atom, a lower alkyl group, or a benzyl group (which can have a halogen atom or a lower alkyl group as a substituent). X, , X2 each independently represent a hydrogen atom, a lower alkyl group, or a halogen atom, and X3 represents a hydrogen atom or a halogen atom. This is a heat-sensitive recording material characterized by containing a novel lactone compound shown in ] as a coloring agent. The sensitive V perusal line material of the present invention adopts a chemical two-component dye imaging method to form a colored image, and the lactone compound represented by the above general formula [1], which is a coloring agent, is acidic during recording. It must coexist with matter. Some specific examples of the lactone compound represented by the above general formula [1] and their coloring hues are as follows. Note that the coloring hue is that of pisphenol A, which is a representative example of an acidic substance. Next, a method for synthesizing the lactone compound represented by the above general formula [1] will be described. First, m-aminophenol derivative

[0] and phthanolic anhydride [m] are condensed to synthesize 4-amino/-2-hydroxy 2-carboxybenzophenone [W]. (R,,R2 have the above-mentioned meanings.) Then, this 4-amino-2-hydroxy-2'-carboxybenzophenone [W] and the diphenylamine derivative [V] (X,,X2,X3,R4,R5 ) has the above-mentioned meaning.
Allow to react for several hours to several tens of hours at about 10 pm. Next, the reactant was poured into ice water, neutralized to pH 8 with NaOH, separated from the furnace, and the resulting crude product was recrystallized from an organic solvent. Specific examples of synthesis methods for some of the above-mentioned compounds are as follows. Synthesis Example 1 Synthesis of 3-(4'-jethylamino-2-hydroxyphenyl)-3-{5'-3''-trifluoromethylphenyl)-amino-2-methoxyphenyl}phthalide of [11]; 4-diethylamino -2-hydroxy-2-carboxybenzophenone 31, Satoshi and 4-methoxy-3
-trifluoromethyldiphenylamine (26.7 g) was stirred in 100% concentrated sulfuric acid at 10°C for 4 hours. Then, it was discharged into 1,000 ml of water, neutralized with NaOH to a solution of 8, and placed in a furnace. The obtained crude product was recrystallized from toluene and ethanol to obtain two base compounds of the above '1}. The melting point of this thing is 1
94-1990, yield was 50%. This product was found to be 3-(4'-diethylamino-2'-hydroxyphenyl)-3-{5'-(
3″-trifluoromethylphenyl)-amino-2′-
It was confirmed to be methoxyphenyl}phthalide. Incidentally, 4-methoxygotrifluoromethyldiphenylamine used in this) can be obtained as follows. m-acetylamide/penzotrifluoride 20, Shigeru,
P-promuanisole 22/thin, 1 spot of hydrium carbonate, 1 g of copper powder, 0/0 iodine, 190-200 oo on oil
Stir for 4 hours. Then 2 parts of n-butyl alcohol and 1 part of 48% caustic soda
Add 7g and stir at loo~11 and 0 for 3 hours. After steam distilling the reactant, it is cooled and the precipitate is filtered through a furnace. Then, vacuum distillation is performed to obtain 4-methoxygotrifluoromethyldiphenylamine of 21 mm. Yield 81% white crystal m・p5
6-9chi Cbp156-16 is 0/2 GHg. Synthesis example
2 3-(4'-jethylamino-2'-hydroxyphenyl)-3-{5'-N-methyl-N-(3-
Synthesis of (trifluoromethylphenyl)amino-2-methoxyphenyl}phthalide; 31.1 g of 4-diethylamino-2-hydroxy-2'-carboxybenzophenone and 28.1 g of 4-methoxy-3'-trifluoromethyl-N-methyldiphenylamine. and 1 in 100 concentrated sulfuric acid
Stir at 0°C for 48 hours. Then drain into 1000ml of water and adjust the pH with NaOH.
Neutralize to 8 and filter. The obtained crude product was recrystallized from toluene/ethanol to obtain the compound (3) of 34 acid. The melting point of this product is 1 to 1 group/5℃, and the yield is 60%.
Met. This product was determined by IR and elemental analysis to be 31(4'-diethylamino-2'-hydroxyphenyl)131{5'-N
-Methyl-N-(3″-trifluoromethylphenyl)
It was confirmed that it was amino-2'-methoxyphenyl}phthalide. In addition, 4-methoxy-3'- used in this)
Trifluoromethyl-N-methyldiphenylamine is obtained as follows. 26.7 g of 4-methoxy-3'-trifluoromethyldiphenylamine, 6 pyramids of dimethyl sulfate, 1 female of water, 70-8 g
Stir at 0°C for 4 hours. After neutralizing the reaction product with dilute NaOH, the oily substance is separated and vacuum distilled. 22. Obtain speckled 4-methoxy-3'-trifluoromethyl-N-methyldiphenylamine. Yield 80%, white crystal m・p 47-49℃, bp 143
~145q0/3 H In this method, phenolic compounds such as Q naphthol, organic acids such as citric acid, metal salts thereof, and solid acids such as activated clay, which are well known as substances with the same effect as this, are used. The heat-sensitive recording material according to the present invention is characterized in that it contains a lactone compound represented by the above general formula [1] as a coloring agent, and the lactone compound represented by the above general formula [1] and an acidic substance, For example, a heat-sensitive recording material can be obtained by binding bisphenol A to a support such as paper or a synthetic resin sheet as a recording layer by means commonly used in the technical field of heat-sensitive recording. Next, an example will be given in which a heat-sensitive recording material was produced by a conventional method using one of the lactone compounds represented by the above general formula [1] and bisphenol A. Production Example 1 g of 3-(4'-jethylamino-2'-hydroxyphenyl)-3-{5'-(3''-trifluoromethylphenyl)-amino-2-methoxyphenyl}phthalide of '1} above. Mix with 1 part of polyvinyl alcohol (10% aqueous solution, PVA205 manufactured by Kuraray Co., Ltd.) and 3 parts of water to obtain a suspension (Liquid A).Meanwhile, mix the bisphenol A base with 1 part of polyvinyl alcohol (same as above) and 3 parts of water. A suspension (liquid B) is obtained.Then, the above-mentioned liquids A and B are mixed, and this mixed liquid is applied to high-quality paper by a conventional method and dried to obtain a sheet-like sensitive V thermal recording material. When a well-known V-thermal head was printed on the obtained sheet-like V-thermal recording material using a built-in thermal printer, a clear black image was recorded.The recorded sheet-like V-thermal recording material Both the skin part had sufficient light resistance, and the skin part did not develop color under pressure or with alcohol. The recording material is one in which a lactone compound represented by the general formula (1) used as a coloring agent reacts with an acidic substance when heated to form an ether bond and change into a corresponding fluoran derivative, producing color. Fluorane-type dyes used as coloring agents in heat-sensitive recording materials have a different coloring mechanism, so they do not have the disadvantage of easily developing color under pressure or in the presence of organic solvents such as alcohol. Furthermore, after the lactone compound represented by the general formula (1) is heated with an acidic substance, it produces a 2,6-diaminofluorane derivative, which has a trifluoro-methyl group at the meta-position of the amino group at the 2-position. Since the dye produced by introducing a phenyl group is a black color with strong light resistance, the heat-sensitive recording material according to the present invention using this as a coloring agent is guaranteed to record black images with excellent light resistance. As described above, the present invention provides a heat-sensitive recording material with excellent performance.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R_1 is a hydrogen atom, a lower alkyl group, or a benzyl group (it can have a halogen atom or a lower alkyl group as a substituent.) represents a lower alkyl group, a cyclohexyl group, a benzyl group (which can have a halogen atom or a lower alkyl group as a substituent), or a phenyl group (which can have a halogen atom or a lower alkyl group as a substituent). ), or R_1 and R_2 are combined to represent -(C
H_2)_4-, -(CH_2)_5-, -(CH_2
)_2-O-(CH_2)-, R_3, R_4
represents a hydrogen atom, a lower alkyl group, an aralkyl group, an amyl group, a phenyl group (provided that at least one of R_3 and R_4 is a hydrogen atom); R_5 represents a hydrogen atom, a lower alkyl group, a benzyl group (a halogen atom, can have a lower alkyl group as a substituent). X_1 and X_2 each independently represent a hydrogen atom, a lower alkyl group, or a halogen atom, and X_3 is a hydrogen atom,
Represents a halogen atom. ] A heat-sensitive recording material characterized by containing a lactone compound represented by the following as a coloring agent.