JP2005279999A - Developer for thermosensitive recording material and thermosensitive recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer for thermosensitive recording material, the color developing sensitivity, water resistance, oil resistance and light fastness of which are excellent equally to or more than those obtained under the condition that bisphenol A is employed as a raw material, and its manufacturing method and a thermosensitive recording material including the developer for the thermosensitive recording material and the thermosentive recording material employing thereof. <P>SOLUTION: The developer for the thermosensitive recording material includes a compound represented by the general formula, wherein preferably R<SB>1</SB>is selected from the group consisting of hydrogen, a methyl group and an isopropyl group, n is integers from 1 through 3, R<SB>2</SB>is selected from the group consisting of hydrogen, a hydroxyl group and a methyl group, m is integers from 1 through 3. The thermosensitive recording material includes the developer for the thermosensitive recording material and a leuco dye and the thermosensitiver recording material is formed by coating the thermosensitive recording material on a support. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a developer for a heat-sensitive recording material, a production method thereof, a heat-sensitive recording material containing the developer for the heat-sensitive recording material, and a heat-sensitive recording material using the same.

  Thermal recording materials are mainly used in facsimiles, measuring devices, medical devices, and the like, and recently, they are used in bar code labels and register receipts used in POS systems and the like, and the amount of use is increasing. With the wide variety of applications, various properties such as water resistance, oil resistance, and light resistance are required for heat-sensitive recording materials.

  The heat-sensitive recording material is generally produced by applying a heat-sensitive recording material containing a leuco dye as a color forming precursor and a developer as an acidic compound as basic components on a support. As the developer, a phenol compound has been used for a long time, and a bisphenol compound represented by bisphenol A is most commonly used (for example, see Patent Documents 1 and 2). However, bisphenol A has recently been reported as an environmental hormone substance that adversely affects reproductive functions, and the demand for an alternative compound is very high.

  In order to solve this problem, acidic compounds having various phenol skeletons have been studied. However, a color developer that replaces bisphenol A with excellent water resistance, oil resistance, and light resistance has not yet been obtained. Is the current situation.

JP-A-56-015394 JP-A-57-151394

  The present invention relates to a developer for a heat-sensitive recording material excellent in color development sensitivity, water resistance, oil resistance, and light resistance, equivalent to or higher than that using bisphenol A as a raw material, and a method for producing the same, and the heat-sensitive recording material The present invention provides a heat-sensitive recording material containing a developer and a heat-sensitive recording material using the same.

上記一般式［１］中、Ｒ_１は水素、炭素数１〜４のアルキル基、炭素数５〜７のシクロアルキル基、置換又は無置換フェニル基、置換又は無置換アラルキル基、アルコキシ基、及び、ハロゲン原子から選ばれるものである。ｎは１〜４の整数を示し、ｎが２〜４のとき、１分子内に存在するＲ_１同士は同じであっても異なっていてもよい。
Ｒ_２は水素、水酸基、炭素数１〜４のアルキル基、炭素数５〜７のシクロアルキル基、置換又は無置換フェニル基、置換又は無置換アラルキル基、アルコキシ基、及び、ハロゲン原子から選ばれるものである。ｍは１〜４の整数を示し、ｍが２〜４のとき、１分子内に存在するＲ_２同士は同じであっても異なっていてもよい。
Ｒ_３は、エトキシエチル基、フラニル基、ピラニル基、及び、ｔｅｒｔ−ブチルカルボニル基から選ばれるものであり、１種類であっても２種類以上であってもよい。
（２）上記一般式［１］で示される化合物中、Ｒ_１が水素、メチル基、及び、イソプロピル基から選ばれるものであり、ｎ＝１〜３である上記（１）に記載の感熱記録材料用顕色剤。
（３）上記一般式［１］で示される化合物中、Ｒ_２が水素、水酸基、及び、メチル基から選ばれるものであり、ｍ＝１〜３である上記（１）又は（２）に記載の感熱記録材料用顕色剤。
（４）上記一般式［１］で示される化合物を、顕色剤全体に対して５０重量％以上含有する上記（１）ないし（３）のいずれかに記載の感熱記録材料用顕色剤。
（５）上記（１）ないし（４）のいずれかに記載の感熱記録材料用顕色剤の製造方法であって、
（ａ）下記一般式［２］で示されるシクロヘキサノン化合物と、下記一般式［３］で示されるフェノール化合物とを、酸性触媒の存在下で反応させて、下記一般式［４］で示されるシクロヘキシリデンビスフェノール化合物を合成する工程、及び、
（ｂ）上記シクロヘキシリデンビスフェノール化合物と、エチルビニルエーテル、２，３−ジヒドロフラン、３，４−ジヒドロ−２Ｈ−ピラン、及び、ジ−ｔｅｒｔ−ブチルジカルボネイトから選ばれる化合物とを反応させて、上記一般式［１］で示される化合物を合成する工程、
を有することを特徴とする、感熱記録材料用顕色剤の製造方法。

上記一般式［２］中、Ｒ_１は水素、炭素数１〜４のアルキル基、炭素数５〜７のシクロアルキル基、置換又は無置換フェニル基、置換又は無置換アラルキル基、アルコキシ基、及び、ハロゲン原子から選ばれるものである。ｎは１〜４の整数を示し、ｎが２〜４のとき、１分子内に存在するＲ_１同士は同じであっても異なっていてもよい。
上記一般式［３］中、Ｒ_２は水素、水酸基、炭素数１〜４のアルキル基、炭素数５〜７のシクロアルキル基、置換又は無置換フェニル基、置換又は無置換アラルキル基、アルコキシ基、及び、ハロゲン原子から選ばれるものである。ｍは１〜４の整数を示し、ｍが２〜４のとき、１分子内に存在するＲ_２同士は同じであっても異なっていてもよい。
（６）上記（１）ないし（４）のいずれかに記載の感熱記録材料用顕色剤と、ロイコ染料とを含有することを特徴とする感熱記録材料。
（７）上記（５）に記載の製造方法により得られた感熱記録材料用顕色剤と、ロイコ染料とを含有することを特徴とする感熱記録材料。
（８）上記（６）又は（７）に記載の感熱記録材料を支持体上に塗布してなることを特徴とする感熱記録材。 Such an object is achieved by the following present inventions (1) to (8).
(1) A developer for a heat-sensitive recording material comprising a compound represented by the following general formula [1].

In the general formula [1], R ₁ is hydrogen, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, an alkoxy group, and Are selected from halogen atoms. n represents an integer of 1 to 4, and when n is 2 to 4, R ₁ existing in one molecule may be the same or different.
R ₂ is selected from hydrogen, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, an alkoxy group, and a halogen atom. Is. m represents an integer of 1 to 4, and when m is 2 to 4, R ₂ existing in one molecule may be the same or different.
R ₃ is selected from an ethoxyethyl group, a furanyl group, a pyranyl group, and a tert-butylcarbonyl group, and may be one type or two or more types.
(2) In the compound represented by the general formula [1], R ₁ is selected from hydrogen, a methyl group, and an isopropyl group, and n = 1 to 3, and the thermal recording according to the above (1). Developer for materials.
(3) In the compound represented by the general formula [1], R ₂ is selected from hydrogen, a hydroxyl group, and a methyl group, and m = 1 to 3 and described in (1) or (2) Developer for heat-sensitive recording materials.
(4) The developer for a heat-sensitive recording material according to any one of (1) to (3), wherein the compound represented by the general formula [1] is contained in an amount of 50% by weight or more based on the whole developer.
(5) A method for producing a developer for a heat-sensitive recording material according to any one of (1) to (4) above,
(A) A cyclohexanone compound represented by the following general formula [2] and a phenol compound represented by the following general formula [3] are reacted in the presence of an acidic catalyst to produce a cyclohexene represented by the following general formula [4]. Synthesizing a silidene bisphenol compound, and
(B) reacting the cyclohexylidenebisphenol compound with a compound selected from ethyl vinyl ether, 2,3-dihydrofuran, 3,4-dihydro-2H-pyran, and di-tert-butyl dicarbonate. A step of synthesizing the compound represented by the general formula [1],
A method for producing a developer for a heat-sensitive recording material, comprising:

In the general formula [2], R ₁ is hydrogen, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, an alkoxy group, and Are selected from halogen atoms. n represents an integer of 1 to 4, and when n is 2 to 4, R ₁ existing in one molecule may be the same or different.
In the general formula [3], R ₂ represents hydrogen, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, and an alkoxy group. And a halogen atom. m represents an integer of 1 to 4, and when m is 2 to 4, R ₂ existing in one molecule may be the same or different.
(6) A heat-sensitive recording material comprising the developer for a heat-sensitive recording material according to any one of (1) to (4) above and a leuco dye.
(7) A heat-sensitive recording material comprising a developer for a heat-sensitive recording material obtained by the production method according to (5) and a leuco dye.
(8) A heat-sensitive recording material obtained by coating the heat-sensitive recording material according to (6) or (7) on a support.

The present invention relates to a developer for a heat-sensitive recording material comprising the compound represented by the general formula [1], a method for producing the same, and a heat-sensitive recording material containing the developer for the heat-sensitive recording material. And a heat-sensitive recording material using the same.
The developer and the heat-sensitive recording material for the heat-sensitive recording material of the present invention do not use bisphenol A, which has been pointed out as an environmental problem, as a raw material, and have color development sensitivity equal to or higher than that using bisphenol A, water resistance, A heat-sensitive recording material having oil resistance and light resistance can be produced.

Hereinafter, the developer for the heat-sensitive recording material of the present invention, a method for producing the same, the heat-sensitive recording material containing the developer for the heat-sensitive recording material, and the heat-sensitive recording material using the same will be described.
First, the developer for the heat-sensitive recording material of the present invention will be described.
The developer for a heat-sensitive recording material of the present invention (hereinafter sometimes simply referred to as “developer”) contains a compound represented by the following general formula [1].

上記一般式［１］中、Ｒ_１は水素、炭素数１〜４のアルキル基、炭素数５〜７のシクロアルキル基、置換又は無置換フェニル基、置換又は無置換アラルキル基、アルコキシ基、及び、ハロゲン原子から選ばれるものである。
ここで、炭素数１〜４のアルキル基としては例えば、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基などが挙げられる。
置換又は無置換フェニル基としては例えば、フェニル基、トルイル基、キシリル基、トリメチルフェニル基などのアリール基が挙げられる。
置換又は無置換アラルキル基としては例えば、ベンジル基などが挙げられる。
アルコキシ基としては例えば、メトキシ基、エトキシ基などが挙げられる。
そして、ハロゲン原子としては、フッ素原子、塩素原子、臭素原子、ヨウ素原子である。

In the general formula [1], R ₁ is hydrogen, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, an alkoxy group, and Are selected from halogen atoms.
Here, examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. .
Examples of the substituted or unsubstituted phenyl group include aryl groups such as phenyl group, toluyl group, xylyl group, and trimethylphenyl group.
Examples of the substituted or unsubstituted aralkyl group include a benzyl group.
Examples of the alkoxy group include a methoxy group and an ethoxy group.
And as a halogen atom, they are a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In the general formula [1], n represents an integer of 1 to 4, and the melting point of the resulting compound can be controlled by adjusting the value of n. Further, when n is 2 to 4, R ₁ together present in one molecule may be different even in the same.

In the compound represented by the general formula [1], R ₁ is preferably selected from hydrogen, a methyl group, and an isopropyl group. Thereby, the compound represented by the general formula [1] can have a high melting point.
Moreover, it is preferable that n is 1-3. By appropriately selecting the number of n from this range, it is possible to obtain a melting point suitable for use as a developer, and to improve the storage stability.

In the general formula [1], R ₂ is hydrogen, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, or an alkoxy group. And a halogen atom.
Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and tert-butyl group.
Examples of the substituted or unsubstituted phenyl group include aryl groups such as phenyl group, toluyl group, xylyl group, and trimethylphenyl group.
Examples of the substituted or unsubstituted aralkyl group include a benzyl group.
Examples of the alkoxy group include a methoxy group and an ethoxy group.
And as a halogen atom, they are a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In the general formula [1], m represents an integer of 1 to 4, and the melting point and acidity of the resulting compound can be controlled by adjusting the value of m. Moreover, when m is 2-4, R ₂ existing in one molecule may be the same or different.

In the compound represented by the general formula [1], R ₂ is preferably selected from hydrogen, a hydroxyl group, and a methyl group. Thereby, since it can be set as high acidity, color developability can be made favorable.
M is preferably 1 to 3. Thereby, since it can be set as high acidity, color developability can be made favorable.

In the general formula [1], R ₃ is selected from an ethoxyethyl group, a furanyl group, a pyranyl group, and a tert-butylcarbonyl group, and may be one type or two or more types. .

The developer of the present invention contains a compound represented by the above general formula [1].
The ratio of the compound represented by the above general formula [1] to the whole developer is not particularly limited, but is preferably 50% by weight or more. Thereby, the melting point of the developer can be increased, and the storage stability of the heat-sensitive recording material using the developer can be improved.

Next, a method for producing the developer for the heat-sensitive recording material of the present invention (hereinafter sometimes simply referred to as “manufacturing method”) will be described. The production method of the present invention is a method for producing the developer of the present invention,
(A) A cyclohexanone compound represented by the following general formula [2] and a phenol compound represented by the following general formula [3] are reacted in the presence of an acidic catalyst to produce a cyclohexene represented by the following general formula [4]. Synthesizing a silidene bisphenol compound, and
(B) reacting the cyclohexylidenebisphenol compound with a compound selected from ethyl vinyl ether, 2,3-dihydrofuran, 3,4-dihydro-2H-pyran, and di-tert-butyl dicarbonate. A step of synthesizing the compound represented by the general formula [1],
It is characterized by having.

First, the step (a) will be described.
In step (a), a cyclohexanone compound and a phenol compound are reacted in the presence of an acidic catalyst to synthesize a cyclohexylidene bisphenol compound.

In the general formula [2], R ₁ is hydrogen, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, an alkoxy group, and Are selected from halogen atoms. Examples of these R ₁ include the same as those described in the general formula [1], but are preferably selected from hydrogen, a methyl group, and an isopropyl group.
Further, n represents an integer of 1 to 4, when n is 2 to 4, R ₁ together present in one molecule may be different even in the same. n is preferably 1 to 3.

  As the cyclohexanone compound represented by the general formula [2], for example, cyclohexanone, 2-methylcyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 4-isopropylcyclohexanone, 3,3,5-trimethylcyclohexanone and the like are preferable. Can be used.

In the general formula [3], R ₂ represents hydrogen, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, and an alkoxy group. And a halogen atom. Examples of these R ₂ include the same as those described in the general formula [1], but are preferably selected from hydrogen, a hydroxyl group, and a methyl group.
M represents an integer of 1 to 4, and when m is 2 to 4, R ₂ existing in one molecule may be the same or different. m is preferably 1 to 3.

  As the phenol compound represented by the general formula [3], for example, phenol, cresol, xylenol, resorcin, pyrogallol and the like can be suitably used.

The acidic catalyst used in the step (a) is not particularly limited, and examples thereof include organic carboxylic acids such as oxalic acid, acetic acid and trifluoroacetic acid, inorganic acids such as hydrochloric acid and sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid, and trifluoro. Organic sulfonic acids such as romethanesulfonic acid, organic phosphonic acids, or heteropolyacids such as phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, and silicotungstic acid can be used.
Although the usage-amount of an acidic catalyst is not specifically limited, It is preferable to use 0.1 times equivalent or more with respect to the phenolic compound used from the point of reaction control and reaction rate.

  In the step (a), a reaction solvent may be used as necessary. The reaction solvent is not particularly limited, and any cyclohexanone compound and phenol compound as raw materials can be dissolved, and any solvent that does not contribute to this reaction can be used without particular limitation.

  In the step (a), the reaction molar ratio when the cyclohexanone compound (H) represented by the general formula [2] and the phenol compound (P) represented by the general formula [3] are reacted is particularly limited. However, the reaction molar ratio (H / P) is preferably 0.125 to 0.5. More preferably, it is 0.25-0.4. As a result, the intended reaction can be efficiently performed and at the same time economic efficiency can be achieved.

Next, the step (b) will be described.
In the step (b), the cyclohexylidenebisphenol compound obtained in the step (a), ethyl vinyl ether, 2,3-dihydrofuran, 3,4-dihydro-2H-pyran, and di-tert-butyl. A compound selected from dicarbonate is reacted to synthesize a compound represented by the above general formula [1].

The step (b) can be usually performed in the presence of a catalyst.
Of these, when a cyclohexylidene bisphenol compound is reacted with one selected from ethyl vinyl ether, 2,3-dihydrofuran, and 3,4-dihydro-2H-pyran, an acidic catalyst may be used. it can.
Although it does not specifically limit as an acidic catalyst used here, For example, organic carboxylic acids, such as oxalic acid, an acetic acid, trifluoroacetic acid, inorganic acids, such as hydrochloric acid and a sulfuric acid, paratoluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, etc. Organic sulfonic acids, organic phosphonic acids, or heteropolyacids such as phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, and silicotungstic acid can be used.

Moreover, when making a cyclohexylidene bisphenol compound react with di-tert- butyl dicarbonate, it can carry out using a basic catalyst.
Although it does not specifically limit as a basic catalyst used here, For example, organic bases, such as inorganic bases, such as sodium hydroxide, lithium hydroxide, and potassium hydroxide, ammonia, a triethylamine, a triethanolamine, etc. can be used.

In step (b), the cyclohexylidene bisphenol compound is reacted with a compound selected from ethyl vinyl ether, 2,3-dihydrofuran, 3,4-dihydro-2H-pyran, and di-tert-butyl dicarbonate. However, the reaction molar ratio of the two is not particularly limited, but can be 0.3 to 1.0 times equivalent to each of the above compounds with respect to 1 equivalent of the hydroxyl group of the cyclohexylidene bisphenol compound. As a result, the intended reaction can be efficiently performed and at the same time economic efficiency can be achieved.

  The thus-obtained compound represented by the general formula [1] can be appropriately subjected to various purification operations such as crystallization, filtration and recrystallization by a usual method. Thereby, a compound with few impurities can be obtained.

Next, the manufacturing method of this invention is demonstrated according to reaction order.
In a reaction vessel equipped with a stirrer, a condenser (condenser), a heating device, a thermometer, etc., a phenol compound and an acidic catalyst are charged and mixed. The cyclohexanone compound is sequentially added thereto. Although reaction temperature is not specifically limited, About room temperature-about 80 degreeC is preferable. The time for sequential addition is not particularly limited, but is preferably 0.5 to 3 hours from the viewpoint of reaction control, reaction rate, and purity of the target compound. The reaction is then carried out for 1-8 hours. Then, the target substance can be obtained by neutralizing the acidic catalyst used for the reaction with a basic substance and removing water, neutralized salts, and unreacted raw materials. The cyclohexylidene bisphenol compound thus obtained can be recrystallized using an appropriate solvent in order to further improve the purity.

  The cyclohexylidene bisphenol compound obtained by the above method is dissolved using a solvent, the above compound for protecting the hydroxyl group is added thereto, and a predetermined amount of catalyst is added. The reaction temperature is not particularly limited, but some have a very low boiling point. Therefore, it is desirable that the reaction temperature be from room temperature to about 50 ° C. so as not to greatly exceed the boiling point. Thereafter, the reaction is carried out for 1 to 6 hours. The product obtained by the reaction is placed in a large amount of water together with the reaction solvent to precipitate the target compound. Furthermore, the target compound can be obtained by drying this.

Next, the heat-sensitive recording material of the present invention will be described.
The heat-sensitive recording material of the present invention is characterized by containing the developer of the present invention or the developer obtained by the production method of the present invention and a leuco dye.

  The leuco dye used in the heat-sensitive recording material of the present invention is not particularly limited. For example, triphenylmethane, fluorane, phenothiazine, auramine, and spiro leuco dyes can be used.

  Examples of triphenylmethane-based leuco dyes include triphenylmethane.

  Examples of the fluorane leuco dye include 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone, CVL), p, p'-benzylidenebis (N, N '-Dimethylaniline (leucomalachite green), 3-diethylamino-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3- (N-methyl-p-toluidino)- 6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3- (N-methylcyclohexyl-N -Methylamino) -6-methyl-7-anilinofluorane, 2-anilino-3-methyl-6-dibutylfluorane, 3 Diethylamino-7- (o-chloroanilino) fluorane, 3-diethylamino-7- (m-trifluoromethylanilino) fluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-6-methylflurane Oran, 3-cyclohexylamino-6-chlorofluorane, 3- (N-isoamyl-N-ethylamino) -6-methyl-7-anilinofluorane, and the like.

  Examples of phenothiazine-based leuco dyes include benzoyl leucomethylene blue and p-nitrobenzoyl leucomethylene blue.

  Examples of the olamine leuco dye include 4,4′-bis (dimethylaminophenyl) benzhydrylbenzyl ether, N-chlorophenyl leucoolamine, N-2,4,5-trichlorophenyl leucoolamine. Etc.

  Examples of spiro leuco dyes include 3-methylspirodinaphthopyrans, 3-ethylspirodinaphthopyrans, benzo-β-naphthopiropyrans, and the like.

  These leuco dyes can be appropriately selected depending on the hue and color developability, and can be used alone or as a mixture of two or more as required.

  In addition to the above-mentioned developer and leuco dye, various additives can be added to the heat-sensitive recording material of the present invention as necessary. Examples of the additive mainly include a binder, a pigment, and a sensitizer.

  The binder is not particularly limited. For example, polyvinyl alcohol, starch, starch derivatives, hydroxyethyl cellulose, methyl cellulose, sodium polyacrylate, polyvinyl pyrrolidone, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, etc. An aqueous emulsion such as a water-soluble polymer, styrene-butadiene latex, styrene-acrylic ester emulsion, or polyvinyl acetate emulsion can be added, whereby the developer composition can be strongly adhered to the support.

  The pigment is not particularly limited, and examples thereof include calcium carbonate, talc, kaolin, calcined kaolin, and aluminum hydroxide.

  The sensitizer is not particularly limited, and examples thereof include stearic acid amide, palmitic acid amide, oleic acid amide, lauric acid amide, ethylene bisstearamide, methylol stearoamide, and the like.

  In addition, generally known waxes, wax-like substances, organic fillers, inorganic fillers, and the like can be added to improve head matching properties, writing properties, whitening of the background, and the like.

  In the heat-sensitive recording material of the present invention, the blending amount of the developer of the present invention, the leuco dye, etc. is not particularly limited. Usually, the developer is 1 to 30 weights with respect to the entire solid content in the heat-sensitive recording material. %, Leuco dye 1 to 15% by weight, and binder 1 to 30% by weight.

The method for preparing the heat-sensitive recording material of the present invention is not particularly limited. For example, in addition to a developer containing a compound represented by the above general formula [1], a leuco dye, and an additive such as a binder, It can be prepared as a solution dissolved in or a mixed solution dispersed. When preparing in such a form, this can be normally apply | coated and used for a support body.
In addition, for example, a leuco dye can be mixed with a binder solution, and a developer can be mixed with the binder solution. When using in such a form, the method of applying each mixed solution to the support after mixing the mixed solutions, the method of applying each mixed solution to the same surface of the same support sequentially, or the same mixed solution There is a method of coating the front and back surfaces of the support separately, and the method is not particularly limited.

Next, the heat-sensitive recording material of the present invention will be described.
The heat-sensitive recording material of the present invention is obtained by coating the heat-sensitive recording material of the present invention on a support.
Although it does not specifically limit as a support body here, Generally paper, a synthetic paper, a synthetic resin film, a metal laminate film, etc. can be used. The support can be selected in a timely manner depending on the application and purpose for which the thermosensitive recording material is used. The heat-sensitive recording material of the present invention is obtained by applying the heat-sensitive recording material of the present invention to these supports by, for example, the method described above, performing a smoothing treatment as necessary, and drying the material. It is what

  Hereinafter, the present invention will be described in detail with reference to examples. Here, “parts” all represent “parts by weight”, and “%” all represent “% by weight”.

1. Preparation of developer for heat-sensitive recording material 1.1 Synthesis of cyclohexylidenebisphenol compound <Synthesis Example 1>
To a reaction vessel equipped with a stirrer, a cooling tube, a heating device, and a thermometer, 300 parts of phenol and 37.5 parts of 35% hydrochloric acid were added and heated to 50 ° C. Thereto, 78.2 parts of cyclohexanone (reaction molar ratio H / P = 0.25) was added and reacted for 6 hours, whereby crystals were deposited. Hydrochloric acid used in the reaction was neutralized by adding 57.5 parts of 25% aqueous sodium hydroxide solution, washed with hot water to remove as much unreacted monomer as possible, and then vacuum dried at 120 ° C. using a dryer. To obtain 53.6 parts of a cyclohexylidenebisphenol compound.

<Synthesis Example 2>
To a reaction vessel equipped with a stirrer, a cooling tube, a heating device, and a thermometer, 300 parts of phenol and 37.5 parts of 35% hydrochloric acid were added and heated to 50 ° C. Thereto, 89.4 parts of 4-methylcyclohexanone (reaction molar ratio H / P = 0.25) was added and reacted for 6 hours to precipitate crystals. Hydrochloric acid used in the reaction was neutralized by adding 57.5 parts of 25% aqueous sodium hydroxide solution, washed with hot water to remove as much unreacted monomer as possible, and then vacuum dried at 120 ° C. using a dryer. To obtain 52.9 parts of a cyclohexylidenebisphenol compound.

1.2 Synthesis of developer <Example 1>
100 parts of the cyclohexylidene bisphenol compound obtained in Synthesis Example 1 is dissolved in 200 parts of acetone, 26.1 parts of ethyl vinyl ether (equivalent ratio of 0.5) is added, and further a catalytic amount of para-toluenesulfonic acid is added. The reaction was carried out at 50 ° C. for 3 hours. After the reaction, the reaction mixture was neutralized by adding triethylamine, and then washed with water.
As a result of analyzing the obtained reaction product using reverse phase chromatography, 25% of the unreacted product was obtained, 60% was reacted on only one side of the hydroxyl group in the compound obtained in Synthesis Example 1, both hydroxyl groups Was 15%.
To this reaction solution, 100 parts of toluene and 100 parts of a 10% aqueous sodium hydroxide solution were added, and the compound reacted with both of the hydroxyl groups was extracted to the toluene side, and the extract was removed. Further, 100 parts of isopropyl ether was added, and the reaction product was extracted to the ether side to remove unreacted products. The ether content was removed from the ether extract to obtain 33 parts of a compound that reacted only with the target hydroxyl group on one side.

<Example 2>
100 parts of the cyclohexylidenebisphenol compound obtained in Synthesis Example 1 is dissolved in 200 parts of acetone, 31.3 parts of 2,3-dihydrofuran (equivalent ratio 0.83) is added, and a catalytic amount of paratoluenesulfonic acid is added. And reacted at 50 ° C. for 3 hours. After the reaction, the reaction mixture was neutralized by adding triethylamine, and then washed with water.
The obtained reaction product was analyzed using reverse phase chromatography. As a result, 32% of the unreacted product, 51% reacted on only one side of the hydroxyl group in the compound obtained in Synthesis Example 1, both hydroxyl groups It was 17% that reacted.
To this reaction solution, 100 parts of toluene and 100 parts of a 10% aqueous sodium hydroxide solution were added, and the compound reacted with both of the hydroxyl groups was extracted to the toluene side, and the extract was removed. Further, 100 parts of isopropyl ether was added, and the reaction product was extracted to the ether side to remove unreacted products. The ether content was removed from the ether extract to obtain 32 parts of a compound that reacted only with the target hydroxyl group on one side.

<Example 3>
100 parts of the cyclohexylidenebisphenol compound obtained in Synthesis Example 2 is dissolved in 200 parts of acetone, 31.3 parts of 3,4 dihydro-2H-pyran (equivalent ratio 1.0) is added, and a catalytic amount of paratoluene is further added. Sulfonic acid was added and reacted at 50 ° C. for 3 hours. After the reaction, the reaction mixture was neutralized by adding triethylamine, and then washed with water.
The obtained reaction product was analyzed using reverse phase chromatography. As a result, 32% of the unreacted product, 51% of the compound obtained in Synthesis Example 2 reacted only on one side of the hydroxyl group, both hydroxyl groups It was 17% that reacted.
To this reaction solution, 100 parts of toluene and 100 parts of a 10% aqueous sodium hydroxide solution were added, and the compound reacted with both of the hydroxyl groups was extracted to the toluene side, and the extract was removed. Further, 100 parts of isopropyl ether was added, and the reaction product was extracted to the ether side to remove unreacted products. The ether content was removed from the ether extract to obtain 35 parts of a compound that reacted only with the target hydroxyl group on one side.

<Example 4>
100 parts of the cyclohexylidene bisphenol compound obtained in Synthesis Example 1 is dissolved in 200 parts of acetone, 81.1 parts of di-tert-butyl dicarbonate (equivalent ratio of 1.0) is added, and 41.5 parts of Triethylamine was added and reacted at 60 ° C. for 6 hours. After the reaction, 24.6 parts of acetic acid was added for neutralization, followed by washing with water.
The obtained reaction product was analyzed using reverse phase chromatography. As a result, 50% of the unreacted product, 46% reacted on only one side of the hydroxyl group in the compound obtained in Synthesis Example 1, both hydroxyl groups It was 4% that reacted.
To this reaction solution, 100 parts of toluene and 100 parts of a 10% aqueous sodium hydroxide solution were added, and the compound reacted with both of the hydroxyl groups was extracted to the toluene side, and the extract was removed. Further, 100 parts of isopropyl ether was added, and the reaction product was extracted to the ether side to remove unreacted products. The ether content was removed from the ether extract to obtain 39 parts of a compound that reacted only with the target hydroxyl group on one side.

3. Preparation of thermosensitive recording material <Example 11>
The following raw materials and blends were separately wet-ground with a ball mill for 24 hours to prepare dispersion liquid mixture A and liquid B.

(3.1) Liquid A, crystal violet lactone 10 parts, stearic acid amide 20 parts, 10% by weight polyvinyl alcohol aqueous solution (“# 105” manufactured by Kuraray Co., Ltd.) 60 parts, calcium carbonate 50 parts, water 150 parts

(3.2) Liquid B: 10 parts of the compound obtained in Example 1 10 wt% polyvinyl alcohol aqueous solution (“# 105” manufactured by Kuraray Co., Ltd.) 20 parts • Calcium carbonate 20 parts • Water 50 parts

The A and B liquids obtained above were blended in the following proportions to prepare a heat sensitive recording material.
(3.3) Thermosensitive recording material / A liquid 20 parts / B liquid 20 parts / 10 wt% polyvinyl alcohol aqueous solution (“# 105” manufactured by Kuraray Co., Ltd.) 15 parts

<Example 12>
In Example 11, a thermosensitive recording material was obtained in the same manner as in Example 11 except that the compound obtained in Example 2 was used instead of the compound obtained in Example 1.

<Example 13>
In Example 11, instead of the compound obtained in Example 1, the compound obtained in Example 2 and the compound obtained in Synthesis Example 1 were used in the ratio of 6: 4, except that the ratio was 6: 4. In the same manner as in No. 11, a heat-sensitive recording material was obtained.

<Example 14>
In Example 11, instead of the compound obtained in Example 1, the compound obtained in Example 2 and the compound obtained in Synthesis Example 1 were used in a ratio of 4: 6, except that the Example was used. In the same manner as in No. 11, a heat-sensitive recording material was obtained.

<Example 15>
In Example 11, a thermosensitive recording material was obtained in the same manner as in Example 11 except that the compound obtained in Example 3 was used instead of the compound obtained in Example 1.

<Example 16>
In Example 11, a thermosensitive recording material was obtained in the same manner as in Example 11 except that the compound obtained in Example 4 was used instead of the compound obtained in Example 1.

<Comparative Example 11>
In Example 11, a heat-sensitive recording material was obtained in the same manner as in Example 11 except that bisphenol A was used in place of the compound obtained in Example 1.

3. Preparation of heat-sensitive recording material The heat-sensitive recording materials obtained in Examples 11 to 16 and Comparative Example 11 were coated on fine paper so that the coating amount after drying was 7 to 9 g / m ² , dried, and heat-sensitive. A recording material was prepared.

  The items described in Table 1 were evaluated for the heat-sensitive recording material obtained above. The evaluation results obtained in Examples 11 to 16 and Comparative Example 11 are shown in Table 1.

(Measuring method)
(1) Content of the compound represented by the general formula [1]:
About the cyclohexylidene bisphenol reactant obtained in Examples 1 to 4, the content of the compound represented by the general formula [1] was measured using reverse phase chromatography. Here, “the content of the compound represented by the general formula [1]” means that the unreacted product, the compound represented by the general formula [1], and the phenolic hydroxyl group obtained by reverse phase chromatography are both It is the content calculated from the area ratio corresponding to each of the reacted compounds.
The measurement conditions of reverse phase chromatography are as follows. When measured under these conditions, the retention time of the compound represented by the general formula [1] is about 8 to 9 minutes.
・ Column: manufactured by TOSOH ・ “TSK-GEL ODS-120T”
-Column temperature: 40 ° C
-Mobile phase: THF / water = 7/3 (volume ratio)
・ Flow rate: 0.5 ml / min,
・ Detection wavelength 280nm

(2) Color developability: Two glass plates with a thickness of 1.2 mm were placed on a 200 ° C. heating plate and heated to this temperature. Next, the heat-sensitive recording material obtained above was sandwiched between the glass plates and held for 3 seconds to develop color. This was observed with the naked eye, and a color that was the same color as in Comparative Example 11 was marked as ◯.

(3) Water resistance: A colored thermal recording material sample was prepared in the same manner as in the evaluation of color development. This was immersed in pure water at 25 ° C. for 2 hours and then air-dried, and the change in the color image was observed with the naked eye. A sample in which no decrease in density was observed was rated as ◎, and a sample in which the density decrease was not significant was marked as ◯.

(4) Oil resistance: A colored thermal recording material sample was prepared in the same manner as in the evaluation of color development. This was sandwiched between PVC wrap films and allowed to stand at 40 ° C. for 24 hours under a load of 200 g / cm ² from the upper side of the color development surface, and the change in the color development image was observed with the naked eye. A sample in which no decrease in density was observed was indicated by ◎, and a sample in which the concentration decrease was not significant was indicated by ◯.

(5) Light resistance: A heat-sensitive recording material sample was developed in the same manner as in the evaluation of color development. This was irradiated with an ultraviolet fade meter (FAL-5 manufactured by Suga Test Instruments Co., Ltd.) for 24 hours, and the change in the color image was observed with the naked eye. The case where almost no fading or discoloration was observed was marked with ◎, and the case where discoloration or fading was slightly recognized was marked with ◯.

Examples 1-4 are the developers of the present invention represented by the above general formula [1]. And Examples 11-16 are the heat-sensitive recording materials of the present invention using these, and in any of water resistance, oil resistance, and light resistance as compared with Comparative Example 11 in which a developer composed of bisphenol A was blended. However, it was possible to obtain a heat-sensitive recording material having the same or better characteristics.

  The developer for heat-sensitive recording material and the heat-sensitive recording material of the present invention can be particularly suitably used for a heat-sensitive recording material having water resistance, oil resistance, and light resistance. For example, it can be suitably used for heat-sensitive recording materials such as barcode labels and register receipts used in facsimiles, measuring devices, medical devices, POS systems, and the like.

Claims (8)

A developer for a heat-sensitive recording material, comprising a compound represented by the following general formula [1].

In the general formula [1], R ₁ is hydrogen, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, an alkoxy group, and Are selected from halogen atoms. n represents an integer of 1 to 4, and when n is 2 to 4, R ₁ existing in one molecule may be the same or different.
R ₂ is selected from hydrogen, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, an alkoxy group, and a halogen atom. Is. m represents an integer of 1 to 4, and when m is 2 to 4, R ₂ existing in one molecule may be the same or different.
R ₃ is selected from an ethoxyethyl group, a furanyl group, a pyranyl group, and a tert-butylcarbonyl group, and may be one type or two or more types. 2. The color for a heat-sensitive recording material according to claim 1, wherein in the compound represented by the general formula [1], R ₁ is selected from hydrogen, a methyl group, and an isopropyl group, and n = 1-3. Agent. In the compound represented by the general formula [1], R ₂ is selected from hydrogen, a hydroxyl group, and a methyl group, and m = 1 to 3. Coloring agent. The developer for a heat-sensitive recording material according to any one of claims 1 to 3, wherein the compound represented by the general formula [1] is contained in an amount of 50% by weight or more based on the whole developer. A method for producing a developer for a heat-sensitive recording material according to any one of claims 1 to 4,
(A) A cyclohexanone compound represented by the following general formula [2] and a phenol compound represented by the following general formula [3] are reacted in the presence of an acidic catalyst to produce a cyclohexene represented by the following general formula [4]. Synthesizing a silidene bisphenol compound, and
(B) the cyclohexylidenebisphenol compound, ethyl vinyl ether, 2, 3
A step of reacting a compound selected from -dihydrofuran, 3,4-dihydro-2H-pyran, and di-tert-butyl dicarbonate to synthesize a compound represented by the above general formula [1];
A method for producing a developer for a heat-sensitive recording material, comprising:

In the general formula [2], R ₁ is hydrogen, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, an alkoxy group, and Are selected from halogen atoms. n represents an integer of 1 to 4, and when n is 2 to 4, R ₁ existing in one molecule may be the same or different.
In general formula [3], R ₂ represents hydrogen, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, and an alkoxy group. And a halogen atom. m represents an integer of 1 to 4, and when m is 2 to 4, R ₂ existing in one molecule may be the same or different. A heat-sensitive recording material comprising the developer for a heat-sensitive recording material according to claim 1 and a leuco dye. A heat-sensitive recording material comprising a developer for a heat-sensitive recording material obtained by the production method according to claim 5 and a leuco dye. A heat-sensitive recording material obtained by coating the heat-sensitive recording material according to claim 6 on a support.