JPH021371A - Thermal recording material - Google Patents

Abstract

PURPOSE:To enhance color forming properties and improve raw preservability or the like by providing a thermal recording layer comprising a diazo compound, a coupling component and a basic substance having a specified partial structure on a support to produce a thermal recording material. CONSTITUTION:A coating liquid is prepared which comprises a diazo compound, a coupling component for color formation through coupling with the diazo compound, and a basic substance having a partial structure of formula I in the molecule thereof. The coating liquid is applied to a support to provide a thermal recording layer, thereby obtaining a thermal recording material. The basic substance having the partial structure of formula I preferably has a melting point of 60-110 deg.C. The diazo compound is a diazonium salt represented by ArN2<+>X<-> (Ar is an aromatic moiety, N2<+> is diazonium group, and X<-> is an anion).

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a heat-sensitive recording material, and particularly to a diazo-based heat-sensitive recording material.

``Prior Art'' As a recording material used in a heat-sensitive recording method, a leuco color-forming wall heat-sensitive recording material is usually used. However, this heat-sensitive recording material has the disadvantage that color develops in unexpected places due to harsh handling, heating, or adhesion of solvents after recording, which stains the recorded image. In recent years, research on diazo-based heat-sensitive recording materials has been actively conducted as a heat-sensitive recording material that does not have such drawbacks. For example, JP-A-Shoj7-/230
Although disclosed in G Otsu issue, Journal of the Image Electronics Engineers of Japan, //, Utaho (iyr2), etc., descriptions using diazo compounds, coupling components, and basic components (including substances that become basic by heat) This method records heat on the material and then irradiates it with light to decompose unreacted diazo compounds and stop color development. Indeed, according to this method, it is possible to stop color development (hereinafter referred to as fixing) in areas that do not require recording.

In addition, in diazo thermosensitive recording materials, in order to prevent pre-coupling during storage, the core material contains at least one of the components involved in the coloring reaction, and a wall is formed around the core material by polymerization. A heat-sensitive recording material using capsules is described in Japanese Patent Application Laid-open No. 19-19-19-19.

However, even in these diazo-based heat-sensitive recording materials, it is desired to impart higher color development, improve shelf life, and improve the light resistance of recorded images. As the uses of recording materials expand, there is an increasing need for recorded images to maintain high quality over a long period of time. Therefore, it is desired to further reduce the coloring of the background after fixing even in the case of a fixing type.

``Problems to be Solved by the Invention'' Therefore, an object of the present invention is to provide a heat-sensitive recording material that has high color development, excellent shelf life and image fastness, and has less coloring on the background after fixing.

"Means for Solving the Problems" The object of the present invention is to combine a diazo compound, a coupling component that develops color by coupling with the diazo compound, and a basic substance having a partial structure represented by H in its molecule. This was achieved using a heat-sensitive recording material characterized by coating a backing yarn recording layer containing the same on a support.

The basic substance of the present invention has a melting point of to 0c or more λ
It is preferable to have a melting point of oo0C or less, and more preferably a melting point of 0°C or more and 1po0C or less.

In addition, the basic substance of the present invention preferably has low solubility in water to reduce pre-coupling during storage, and has excellent compatibility with coupling components to improve color development. preferable.

Among the basic substances of the present invention, preferred ones are the following formation (I
).

In the formula, Y represents a substituted or unsubstituted alkyl group, aryl group, or aralkyl group, and R1 and R2 may be linked to each other to form a ring. In that case, the linking ring may further contain a heteroatom.

Furthermore, as the basic substance of the present invention, the following general formula (I
Those shown in I) are preferred.

In the formula, R3 and R4 are substituted or unsubstituted alkyl groups,
Indicates an aryl group or an aralkyl group.

More preferably, it contains an ether bond or a thioether bond as shown in the following general formula (1).

(III) In the formula, X1dO or s, Ar, and Ar2 represent a substituted or unsubstituted phenyl group or naphthyl group.

Furthermore, among the basic substances of the present invention, those having a structure represented by the following general formula (IV) are also suitable.

In the formula, may form a ring. In this case, the connecting ring may contain other heteroatoms, and specific examples of preferred heterocycles include a morpholine ring, a radine ring, and the like.

Y, R1, R2, RrtR of the general formulas (1) to (■)
and alkyl represented by R6
5 group, aryl group or aralkyl group and A r 1, Ar
2. Examples of substituents for the phenyl group or naphthyl group represented by Ar3 include alkyl groups, alkoxy groups, alkylthio groups, /.logen atoms, alkylsulfonyl groups, carbamoyl groups, alkylsulfonyl groups, ureido groups, cyan groups, Examples include acylamino group.

Preferred examples of compounds are as follows.

/) N,N'-bis(3-phenoxy-!-hydroxypropyl)pi<radine, 2) N,N'-bisC3-(p-methylphenoquine)
-! -hydroxypropyl] syrin Propyl) Pipecillin j) N,N'-bis[3-(β-naphthoxy)-cohydroxyprogyl]pipecillin B) N-J-(β-nandoxy)-1-hydroxypropyl-N'-methyl Piperazine 7) N-C3-<β-naphthoxy)-2-hydroxy]
propylmorpholine♂)/, 4t-bis[(3-morpholino-cohydroxy)propyloki7]benzenta)/, 3-bis[(3-morpholino-1-hydroxy)propyloki7]benzene10)/, 4L-bis ([(J-(N-methylbiradino)-2-hydroquine]furobyloxy)benzene It is needless to say that the present invention is not limited to these examples. Also, two or more of these may be used in combination. It is also possible to further use a known poorly water-soluble or water-insoluble basic substance, or a substance that generates an alkali upon heating.The content of these known substances relative to the basic substance of the present invention is t.

The range below 10,304 is particularly effective.

Preferred compounds among these known basic substances include guanidines, imidacillins, amidines, and the like.

The diazo compound used in the present invention is -forming ArN2
X (wherein, Ar represents an aromatic moiety, N2+ represents a diazonium salt, and X- represents an acid anion.)
It is a diazonium salt represented by

It is a compound that can develop color by causing a camping reaction with a coupling component, and can be decomposed by light.

Specifically, as the aromatic moiety, those having the following formation are preferable.

n In the formula, Y represents a hydrogen atom, a substituted amine group, an alkoxy group, an aryloxy group, an arylthio group, an alkylthio group, or an arylamino group, and R represents a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group, an arylamino group Or halogen (I.

Br, 01! , F). n represents/or 2.

The substituted amine group of Y includes a monoalkylamino group, a dialkylamino group, an arylamino group, a morpholino group,
Bi is preferably a lysino group, a pyrrolidino group, or the like.

Specific examples of diazoniums that form total salts include ≠-diazo/-dimethylaminebenzene, ≠-diazo/-diethylaminobenzene, ≠-diazo/-dipropylaminobenzene, t-diazo/-methylbenzylaminobenzene, Hiro- diazo-7-dibenzylaminobenzene,
Hiro-diazo-/-ethylhydroxyethylaminobenzene, Gudiazo-/-diethylamine-3-methoxybenzene, ≠-diazo/-dimethylamine-λ methylbenzene, ≠-diano'-/-benzoylamino-, 2,
! -jethoxybenzene, Hiro-diaso/-morpholinobenzene, gusiaso/-morpholino-2B-shedquinobenzene, kudiazo-/-morpholino-λ, j-
Dibutoxybenzene, ≠-diazo/-anilinobenzene, ≠-diazo/-tolylmercapto-2,j-jethoxybenzene, Hiro-diazo/, 4t-methquinhenzoylamine-λ,! -jethoxybenzene, goudiazo-/-pyrrolidino-2-ethylbenzene, and the like.

As a specific example of acid anidine, CnF2r++IC0O
(n is an integer from 3 to ri), CmF2m+l503 (m is an integer from J-♂), (CzFzz÷□502)2CH(t
is an integer of /~/♂), HC(CH3)3C3H27CONI-I, or PF6 is preferable because it causes less increase in color during raw storage.

Specific examples of the diazo compound (diazonium salt) include the following examples.

C4H9 (n is an integer from 3 to ri) Examples include PF6.

In particular, the acid anion includes a /9-fluoroalkyl group or a 2-fluoroalknyl group.QC41
-I9 QC4H9 OC2H5 OC2H5 C4H9 C2H5 OC2H5 OC4H9 C(CH3)3 C4H9 The coupling component used in the present invention is one that forms a dye by coupling with a diazo compound (diazonium salt) in a basic atmosphere. Examples include resorcinol, phloroglucin, and λ.

3-dihydroxynaphthalene-B-sodium sulfonate, /-hydroxy-2-naphthoic acid morpholinopropylamide, /, terdihydroxynaphthalene 1.2+
3-dihydrox7naphthalene1. ! .

3-Dihydroxy-O-naphthalenesulfonic acid anilide-1-hydroxy-3-naphthoic acid morpholinopropylamide, 2-hydroxy-3-naphthoic acid anilide, 2
-Hydroxy-3-naphthoic acid-λ'-methylanilide, λ-hydroxy/-3=naphthoic acid ethanolamide,
! -Hydroquine 3-naphthoic acid octylamide,! -Hydroquine 3-naphthoic acid U-N-dode/luoquin-propylamide, 2-hydroxy/-3-naphthoic acid tetradenlamide, acetanilide, acetoacetanilide,
Benzoylacetanilide, /-phenyl-3-methyl-terhirazolone, /-(u'≠'II!lI'-trichlorophenyl)-3-benzamide-terpyrazolone, /-(,2',≠',z'- trichlorophenyl)-
Examples include 3-anilino-terhirazolone, /-phenyl-3-phenylacetamido-y-pyrazolone, and the like.

Furthermore, by using two or more of these coupling components in combination, an image of any color tone can be obtained.

In addition, in the present invention, if necessary, at least one or more of aromatic ethers or esters, alcohols, phenols, sulfonamides, and acid amides may be further included in the coloring agent 1 during raw storage. Aromatic ethers that are preferred for improving properties, thermochromic properties, and reducing the decrease in optical density of recorded images due to long-term storage after thermal recording are represented by A r -0-R, and specific examples include /) λ-benzyloxynaphthalene, 2) / -p-biphenyloxy-2-phenylethane J),! -p-chlorobenzyloxynaphthalene≠)/
, -1-diphenoxyethane j) / -phenoxy-2-p-crocotzenoxyethane B) p-biphenyl-β-methoxyethiethe 7) p
-biphenyl-β-cyclohexyloxyethyl ether and the like.

and t2 or R3 and R4 may be the same or different, a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group, an acyl group, a rogen atom, a cyan group,
It represents an aryl group, an alkyloxycarbonyl group, or an alkyloxycarbonyl group. Further, R1 and R2 or R3 and R4 may be linked to form a ring.

Among the substituents represented by R, an alkyl group having a carbon atom number/~IO that may be substituted with an alkoxy group, an aryloxy group, a halogen atom, or an aryl group, or an alkyl group, an alkoxy group, a hydroxy group, or an alkyl group, which may be substituted with an aryl group. Particularly preferred is an aryl group having 6 to 2 carbon atoms which may be substituted with atoms.

Specific examples include /)-2-benzoyloxynaphthalene, ri/, 2-
Bis(β-phenoxyethoxycarbonyl)ethane J)/, ≠-bis(β-phenoxyethoxy/carbonyl)butane 4L)/-p-methylbenzoyloxy7-. 2-
Examples include p-biphenyloquinethane/-hydroxy-niphenylene7carbonylnaphthalene.

Examples of alcohol include:

-OH In the above formula, R is an alkyl group that may have a substituent,
It may be linear or branched, or cyclic or unsaturated, and may be a halogen atom, an acyl group, an alkoxy group, a hydroxy group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an acylamino group, a cyan group, or a nitro group. Alternatively, it may be substituted with one or more acyloxy groups.

Specific examples include /) p-xylenol, 2) m-xylenol, 3) hydroxybenzyl alcohol, 4t
) hydroxybenzyl alcohol, p-methoxyphenoxyethanol, perhydrobisphenol A, 7) naphthylene diol, male) methylxylylene diol, 9) methoxyquinyl diol, and the like.

Phenols are represented by Ar-OH, specifically /)p
-t-butylphenol, -ript-octylphenol 3) p-α-cumylphenol, 4t) p-t-
Pentylphenol, 21-dimethylphenol,
2.4t, tertrimethylphenol, 7)
3-Methyl-≠-inpropylphenol, ? ) p-benzylphenol, r) o-cyclohexylphenol, 10) p-(diphenylmethyl)phenol, //)
Examples include p-benzyloxyphenol-/, u, 4-bis(hydroxymethyl)-p-cresol.

Amides include carboxylic acid amides and sulfonic acid amides, and arylcarboxylic acid amides and arylsulfonic acid amides are particularly preferred.

To give specific examples, examples of arylcarboxylic acids include /) Benzamide 2) Ethylbenzamide 3) Inpropylbenzamide! I) dimethylbenzamide j) chlorobenzamide B) methoxybenzamide, etc. Examples of the sulfonic acid amide include l ethylbenzenesulfonamide, 20-) luenesulfonamide, 30-methoxybenzenesulfonamide≠ chlorobenzenesulfonamide! Examples include ethoxybenzenesulfonamide, <)p-toluenesulfonamide, and the like.

Next, when the thermal recording paper of the present invention is constructed using a microcassicle formation method, the core material of the microcapsules is dissolved or dispersed in a water-insoluble organic solvent, and after emulsification, the microcapsule walls are formed around it. However, the organic solvent preferably has a boiling point of 2080 or higher. Specifically, phosphoric acid esters, phthalic acid esters, other carboxylic acid esters, fatty acid amides, alkylated biphenyls, alkylated terphenyls, chlorinated paraffins, alkylated naphthalenes, diarylethanes, etc. are used. Specific examples include tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, tricyclohexyl phosphate, diptyl phthalate, dioctyl phthalate, dilauryl phthalate, dicyclohexyl phthalate, butyl oleate, diethylene glycol dibenzoate, and heptane. Dioctyl acid, didutyl sebacate, dioctyl adipate, trioctyl trimellitate, acetyltriethyl citrate, octyl maleate, dibutyl maleate, isozolobylbiphenyl, isoamyl biphenyl, chlorinated, o-roughin, diisopropylnaphthalene, /
．． /'-ditollylethane! , N-dibutyl-tertiary aminophenone, N-dibutyl-tertiary octeraniline, and the like.

Among these, diptyl phthalate, tricresyl phosphate, diethyl phthalate, dibutyl maleate, etc. can be mentioned.

Microcapsules are made by emulsifying a core material containing a reactive substance and then forming a wall of polymeric material around 70 oil droplets. A reactant forming a polymeric substance is added to the interior of the oil droplet and/or to the exterior of the oil droplet. Specific examples of polymeric substances include polyurethane, polyurea, polyamide, polyester, polycarbonate, urea-formaldehyde resin, melamine resin, polystyrene, styrene methacrylate copolymer, styrene-acrylate-1 copolymer, gelatin, polyvinylpyrrolidone, Examples include polyvinyl alcohol.

Two or more types of polymeric substances can also be used in combination.

Preferred polymeric materials are polyurethane, polyurea, polyamide, polyester, polycarbonate, and more preferred are polyurethane and polyurea.

The effect of forming microcapsule walls is particularly great when using a method of forming microcassicles by polymerizing a glue actant from inside an oil droplet.

That is, it is possible to obtain capsules, which are desirable as a recording material and have a uniform particle size and excellent storage stability, within a short period of time.

This method and the compound envelope are described in the specifications of U.S. Pat.

For example, when polyurethane is used as a capsule wall material, a polyvalent isocyanate and a second substance (such as a polyol) that reacts with it to form the capsule wall are mixed into an oily liquid to be encapsulated, emulsified and dispersed in water, and then heated to a temperature. By rising, a polymer formation reaction occurs at the oil droplet interface, forming a microcapsule wall.

In this case, regarding the polyisocyanate to be used and the polyol and polyamine to be reacted with it, US Pat.

No. 773, 675, No. 3,773, 2 Otsu♂, Tokuko Sho≠
These are disclosed in r-4103 Hiro No. 7, Kota 24t/Tata, Tokkai Sho 4t DoichigO/ri No. 7, and Dogu♂-♂Hiro0♂Otsu, and they can also be used. .

Moreover, tin salt etc. can also be used together.

In particular, polyvalent isonene I- is added to the hawk/wall-forming substance,
When a polyol is used as the second wall film-forming substance, it has good shelf life (preferably).Also, by combining the two, the thermal permeability of the reactive substance can be changed as desired.

Examples of the polyvalent incyanate that is the first wall film-forming substance include m-)22 diincyanate, p-phenylene diisocyanate, 2. Otsu-tolylene diisocyanate, '+4th') diisocyanate, naphthalene-/, Hiro-diisocyanate, diphenylmethane-4t, ta'-diisocyanate, 3,3'-dimethoxy-gutsuhiro'-biphenyl-diincyanate,
3,3'-dimethyldiphenylmethanog, j'-diisocyanate, quinrylene-/, kudiisocyanate, ≠ ≠'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-l2.2-diisocyanate,
Butylene-/! -Diisocyanate, cyclohexylene/1,2-diisocyanate, 4L-diisocyanate, etc., ≠', Hiro''-triphenylmethane triincyanate, toluene-2, 1, t , 4-triisocyanate, Hiroshi, Hiroshi'-dimethyldiphenylmethane, tetracyanate such as 2',t,6/-tetraincyanate, adducts of hexamethylene diisocyanate and trimethylolpropane 1.!
, g-tolylene diisocyanate and trimethylolpropane, xylylene diisocyanate and trimethylolpropane, and tolylene diisocyanate and hexanetriol.

Examples of the polyol that is the second wall-forming substance include (RI, aliphatic and aromatic polyhydric alcohols, hydroxy polyesters, and hydroxy polyalkylene ethers). Examples of preferred polyols include ethylene glycol, /, 3-propanediol, / ≠-butanediol, /, j- is methanediol, /, O-hexanediol, / 7-hebutansinol /, ♂-octanediol, furopylene gelicol, 2,3-dihydroxy Butane, /, 2-dihydroquine butane, /.

3-dihydroxybutane 1.2. ．． 2-dimethyl-/3
-Propanedionope2. Hiro - vantanediol! ,
! -Hexanediol, 3-methyl-/.

! -hantandio/he/, 11-cyclohexanedimethanol, dihydroxycyclohexane, diethylene glycol, /, 2. O-trihydroquine hexane,
Phenylethylene glycol, /.

/, /-) Limethylolpropane, hexanetriol, pentaerythritol, glycerin, /.

condensation products of aromatic polyhydric alcohols such as gauge (,2-hydroxyethoxy)benzene, resorcinol dihydroxyethyl ether, and alkylene oxides, p-
Xylylene glycol, m-xylylene glycol, α
, α'-dihydroxy-p-diisopropylbenzene, and the like.

Further examples include g,4t'-dihydroxy-diphenylmethane, λ-(r)+l)'-dihydroxydiphenylmethyl)hensyl alcohol, adducts of ethylene oxide to hisphenol A, and adducts of propylene oxide to bisphenol A. . The polyol has a ratio of hydroxyl groups of 0.0λ to 1 mole of isocyanate groups.
Preferably, 2 mol is used.

When making microcapsules, water-soluble polymers can be used, and the water-soluble polymers may be any of water-soluble anionic polymers, nonionic polymers, and amphoteric polymers O.

As the anionic polymer, both natural and synthetic polymers can be used, and examples thereof include those having -C00--8Qi groups. Specific anionic natural polymers include gum arabic and alginic acid.
Semi-synthetic products include carboxymethyl cellulose, phthalated gelatin, sulfated starch, sulfated cellulose, and lignin sulfonic acid.

Synthetic products include maleic anhydride-based (including hydrolyzed) copolymers, acrylic acid-based (including methacrylic acid-based) polymers and copolymers, vinylbenzenesulfonic acid-based polymers and copolymers, Examples include carboxy-modified polyvinyl alcohol.

Examples of nonionic polymers include polyvinyl alcohol, hydroquine ethyl cellulose, and methyl cellulose.

Examples of amphoteric compounds include gelatin.

These water-soluble polymers are 0. It is used as an aqueous solution of O/~/OW t %. The particle size of microcapsules is 2
Adjusted to 0 μ or less. In general, the particle size! If θμ is exceeded, the print image quality tends to deteriorate.

Especially when heating with a thermal head from the coated layer side, to avoid pressure blurring! It is preferably less than μ.

Of the diazo compound, coupling component, or basic substance that is the main component used in the present invention, either one of them is used as the core material of the microcapsule, or two of them are used as the core material of the microcapsule.
One species or three species can be used. 2
When seeds are contained in the core material of microcapsules, they may be in the same ρ microcapsule or in separate microcapsules.

In addition, 3 types are the core of microcapsules! When they are contained in Iyl substances, they cannot be contained in the same microcapsule at the same time, but there are various combinations. Other ingredients not contained in the core material of the microcapsules are used in the heat-sensitive layer outside the microcapsules.

Even if the compound of the present invention is in the core of the microcapsule,
It can be outside.

When making microcapsules, they can be made from an emulsion containing 0.2 wt% or more of the component to be microencapsulated.

Diazo compound used in the present invention, coupling component,
Even if the basic substance is contained inside the microcapsule or in the heat-sensitive layer outside the microcapsule, the coupling parabolic is 0.0% based on the weight of the diazo compound. /~10 parts by weight, 0 basic substances
．． 7~. Preferably, it is used in an amount of 20 parts by weight. Also, the diazo compound is 0.0! It is preferable to apply 0.097 m2.

When the diazo compound, coupling component, and basic substance used in the present invention are not microencapsulated, they are preferably used after being dispersed in solid form with a water-soluble polymer using a sand mill or the like. Preferred water-soluble polymers include water-soluble polymers used when making microcapsules.

At this time, the concentration of the water-soluble polymer is 2 to 3 ONvt, and the diazo compound, campling component, and basic substance are respectively j, ..., IA
Ow was put in charge.

The dispersed particle size is preferably 10 microns or less.

In addition to the heat-sensitive recording layer of the present invention formed of a single layer,
It goes without saying that it may be formed of multiple layers such as a diazo layer and a compulsory component layer.

A carbamate ester compound and an aromatic methoxy compound can be further added to the heat-sensitive recording material of the present invention for the purpose of further improving thermal coloring properties. It is believed that these compounds lower the melting point of the camping component or basic substance or improve the thermal permeability of the microcapsule wall, resulting in a higher practical concentration.

Specific examples of the carbamate ester compounds include N-phenylcarbamic acid ethyl ester, N-phenylcarbamic acid pendyl ester, N-phenylcarbamic acid phenethyl ester, carbamic acid benzyl ester,
Examples include carbamic acid phthyl ester, carbamic acid isopropyl ester, and the like. Specific examples of aromatic methoxy compounds include! - methoxybenzoic acid, 3. ! -dimethoxyphenylhiL 2-methoxynaphthalene, /.

3,! -trimethoxybenzene, p-benzyloxy7methoxybenzene, and the like.

In either case, the amount used is o, oi to 10 parts by weight, preferably 0.0 to 10 parts by weight, based on the coupling component/part by weight. / to 2 parts by weight, but may be selected as appropriate in order to adjust the coloring density to a desired level.

The thermosensitive recording material of the present invention includes a free radical generator (a compound that generates free radicals when irradiated with light) that is used in photopolymerizable compositions, etc. for the purpose of reducing yellowing of the background after light conditioning. You can add Free % f group generators include aromatic ketones (e.g., benzophenone, ≠, ri'-bis(dimethylamino)benzophenone, p,4t'-bis(diethylamine)(nzophenone, ≠-methoxyk'(dimethylamino)benzophenone). , ≠, ≠′-dimethoxybenzophenone, V-dimethylaminobenzophenone,
Hiro-methoxy, 3,3'-dimethylbenzophenone, l
-Hydroxycyclohexylphenylketone, Hiro-dimethylaminoacetophenone, x-methyl-/-[tl-
(methylthio)phenyl]-2-morpholino-propanone-/-acetophenone, benzyl), cyclic aromatic ketones (e.g., fluorenone, anthrone, xanthone, thioxanthone, 2-chlorothioxanthone, λ, Hiro-dimethylthioxanthone, 2. gauge ethyl thioxanthone, acridone, N-ethyl acridone, benzanthrone), quinones (e.g. benquinone sl
3+"h') Methyl-B-bromobenzoquinone, λ, 6
-G〇-de/rubenzoquinone, /, ≠-naphthoquinone, 1-impropoxy-/, 1. t-naphthoquinone, /
9.2-naphthoquinone, anthraquinone, λ-chloroanthraquinone, λ-methylanthraquinone, λ-te
rt-butylanthraquinone, phenanthraquinone),
Benzoin, benzoin ether M (e.g. benzoin methyl ether, benzoin ethyl ether, λ).

-monodimethoxy λ-phenylacetophenone, α-methylolbenzoin methyl ether), aromatic polycyclic hydrocarbons (e.g. naphthalene, anthracene, phenanthrene, pinne), aso compounds (e.g. azobisisobutyronitrinope α- azo-/-cyclohexanecarboxonitrile, azobisvaleronitrile), organic disulfides (e.g., thiuram disulfide), and acyloxime esters Th (e.g., benzyl-(0-ethoxycarbonyl)-α-monoxime). It will be done.

The amount to be added is based on the diazonium compound/part by weight.
The free radical generator is preferably used in an amount of o, oi to j parts by weight. More preferably 0. The range is from / to / parts by weight.

By encapsulating the free radical generator together with the diazonium salt as the core material of microcapsules, the aforementioned yellowing of the skin after photofixing can be eliminated over time.

In the heat-sensitive recording material of the present invention, a polymerizable compound having an ethylenically unsaturated bond (hereinafter referred to as a vinyl monomer) can be used for the purpose of reducing yellow appearance in the background area after photofixing. A vinyl monomer is a compound having at least 7 ethylenically unsaturated bonds (vinyl group, vinylidene group, etc.) in its chemical structure, and is a compound that has at least 7 ethylenically unsaturated bonds (vinyl group, vinylidene group, etc.), and is a compound that contains monomers, polymers, i.e., dimers, trimers, and other oligomers. They have chemical forms such as a combination thereof and a copolymer thereof. Examples of these include unsaturated carboxylic acids and their salts, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds, amides of unsaturated carboxylic acids and aliphatic polyhydric amine compounds, etc. can be given.

The vinyl monomer is 0.0% based on the diazo compound/part by weight. −
! It is used at a ratio of ~2θ weight + j' parts. Preferably 7~
The proportion is 10 parts by weight.

The vinyl monomer is used by being contained in the core material of the microcapsule together with the diazo compound, but at this time, the solvent for the core material (
7 parts or all of the organic solvent used as a dispersion medium) can be replaced with a vinyl monomer.

When the heat-sensitive recording material of the present invention contains a diazo compound as a core material, by incorporating a coupling reaction deactivator outside the microcapsules, the diazo compound present in the aqueous phase and the diazo compound in the incomplete capsules can be removed. (i.e., the diazo compound that is not completely blocked by the capsule wall) and the coupling reaction quencher react, causing the diazo compound to lose its coupling reaction (coloring reaction) ability and preventing capri. can.

The coupling reaction deactivator may be any substance that reduces the coloring of a solution containing a diazo compound, and the diazo compound is dissolved in water or an organic solvent, and then the diazo compound is dissolved in water or an organic solvent. The diazo compound can be selected by adding other compounds and observing the color change of the diazo compound.

Specific examples include hydroquinone, sodium bisulfite, potassium nitrite, hypophosphorous acid, tin chloride, and formalin. In addition to this, H.

5unders [The Aromatic Di
az.

-Compounds and Their Te
chnicalApplications'+ (Lo
You can also choose from the ones listed on pages 103 to 30, published in 1997, pages 103 to 30.

The coupling reaction quencher is preferably one that has little coloration and has few side effects. More preferably, it is a water-soluble substance.

The coupling reaction deactivator is used to the extent that it does not inhibit the thermal coloring reaction of the diazo compound.
The deactivator is used in a range of o, oi moles to 2 moles per mole. More preferably, it is used in a range of 0.02 mol to 1 mol.

The coupling reaction quencher of the present invention is a liquid in which microcapsules containing a diazo compound are completely dispersed after being dissolved in a solvent;
Alternatively, it can be used by adding a compulsory component or a basic substance to a dispersion liquid or a mixture thereof. Preferably, the quencher is used in the form of an aqueous solution.

The heat-sensitive recording material of the present invention contains silica, barium sulfate, titanium oxide, aluminum hydroxide, zinc oxide,
Pigments such as calcium carbonate, fine powders such as styrene beads, urea-melamine resin, etc. can be used.

Likewise, metal soaps can also be used to prevent sticking. The usage amount of these is 0.2
~7g/m2.

Furthermore, a heat-melting substance can be used in the heat-sensitive recording material of the present invention in order to increase the heat-recording density.

The thermofusible substance is a substance that is solid at room temperature and has a melting point of SO~/jO'C that melts when heated by a thermal head, and is a substance that dissolves a diazo compound, a camping component, or a basic substance. The thermofusible substance is 0. /
Dispersed in particles of ~10μ, solid content O0.2~777
used in an amount of m2. Specific examples of the heat-melting substance include N-substituted fatty acid amides, ketone compounds, urea compounds, esters, and the like.

The heat-sensitive recording material of the present invention can be coated with a suitable binder.

Binders include polyvinyl alcohol, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, gum arabic, pyratine, starch and hisso derivatives, polyvinylpyrrolidone, polystyrene, polyacrylamide, polyester, casein, styrene-butadiene latex, acrylonitrile-butadiene. latex, polyvinyl acetate,
Various emulsions of polyacrylic esters and ethylene-vinyl acetate copolymers can be used. The amount used is solid content 0. j-jf/m2.

In the present invention, in addition to the above materials, citric acid is used as an acid stabilizer.
Tartaric acid, oxalic acid, boric acid, phosphoric acid, pyrophosphoric acid can be added.

The heat-sensitive recording material of the present invention is produced by preparing a coating liquid containing a diazo compound, a coupling component, a basic substance, and other additives, and coating it on a support such as paper or a synthetic resin film by applying it with a parser, a blade, or the like. Air knife coating, gravure coating,
Apply by coating methods such as roll coating, spray coating, dip coating, etc., and dry to obtain a solid content of λ, J'~231.
A heat-sensitive layer of i'/m2 is provided. Alternatively, a coupling component, a basic substance, and other additives may be added as a core material of microcapsules, or they may be solidly dispersed, or they may be dissolved as an aqueous solution and then mixed to prepare a coating solution. Coated on support and dried to a solid content of 2.1
A pre-coat layer of 0 y/m2 is provided, and the main component diazo compound and other additives are added thereon as core materials for microcapsules, or they are solid-dispersed or dissolved as an aqueous solution and then mixed. The coating layer is coated and dried to give a solid content of /~/! ;? It is also possible to use a laminated type with a coating layer of /m2. The laminated type heat-sensitive recording material may have a reverse order of lamination, and the coating method may be sequential coating or simultaneous coating of the laminated layers. This laminated heat-sensitive recording material exhibits particularly excellent performance in long-term storage.

It is also possible to provide an intermediate layer on the support as described in the specification of Japanese Patent Application No. 77 Otsu-Otori, etc., and then coat the heat-sensitive layer thereon.

The paper used for the support is heat extracted pH 6 sized with a neutral sizing agent such as an alkyl ketene dimer.
- Neutral paper (described in the Tokukai Akari!-l Ko2♂/issue)
It is advantageous in terms of storage stability over time.

In addition, in order to prevent the coating liquid from penetrating the paper and to improve the contact between the recording heat head and the heat-sensitive recording layer, Japanese Patent Application Laid-Open No. 7-IIT
Paper described in Otsu and No. 7 and having a Beck smoothness of 0 seconds or more is advantageous.

In addition, paper with an optical surface roughness of gμ or less and a thickness of ≠0 to 7jμ as described in JP-A-5g-/3 Otsuhiro Octopus, and paper with a density of 0 as described in JP-A-5G-2RIO-7゜ri? Paper with /cfn3 or less and optical fusing rate of /J- or more, JP-A-Sho! ♂-Canadian standard water temperature (J-cho SP♂/2
/) Paper made from pulp beaten to ≠oocc or higher to prevent penetration of coating liquid, JP-A Showyu F-3J&
No. 5 of JP-A-Sho, which improves the color density and resolution by using the glossy side of base paper made by a Yankee machine as the coating surface, as described in No. 5 of JP-A-Sho! Ta 3! The paper described in No. 5, in which the base paper is subjected to corona discharge treatment to improve its coating suitability, can also be used in the present invention and gives good results.

In addition to these, any support commonly used in the field of heat-sensitive recording paper can be used as the support of the present invention.

The heat-sensitive recording material of the present invention can be used as printer paper for facsimiles and electronic computers that require high-speed recording, and can be fixed by exposing it to light after heating and decomposing unreacted diazo compounds. .

In addition, the heat-sensitive recording material of the present invention is used in so-called heat-developable copying, in which the unexposed image area develops color by overlapping it with a light-transmitting support on which an image is recorded and exposing it to light, and then heating the entire surface. Particularly preferred is use as paper. With such heat-developable copying paper, the background area is heated over the entire surface during development, so if a known basic substance such as triphenylguanidine is used, the background area is likely to turn yellow. On the other hand, it was found that this coloration was significantly improved by using the basic substance of the present invention.

"Example" The present invention will be described in detail below, but it goes without saying that the present invention is not limited thereto.

Example 1 The following diazo compound 3. ≠5 parts and (3:l) adduct of xylylene diisocyanate and trimethylolpropane/
, 1' part was added to a mixed solvent consisting of 11 parts of tricresyl phophei and 1 part of ethyl acetate, and dissolved by heating. This diazo compound solution is mixed with 51.2 parts of polyvinyl alcohol and water! 1 part dissolved in an aqueous solution, and emulsified and dispersed at 20"C to obtain an emulsion with an average mass of 2.J-μ. To the obtained emulsion, 100 parts of water was added, and while stirring, to
After 2 hours of heating to 0°C, a capsule liquid containing a diazo compound in the core substance was obtained.

Next, the naphthol ASLO part and the N,N'-bis(3-phenoxy-2-hydroxypropyl)pi were dispersed in a sand mill for about 2≠ hours by adding 10 parts of radine to io parts of the J-4 polyvinyl alcohol aqueous solution. A dispersion with an average particle size of 3 μm was obtained.

Furthermore, 20 parts of p-benzyloxyphenol, 700 parts of an aqueous polyvinyl alcohol solution related to A, and 700 parts of water were added and dispersed in an Indian shaker for 2 hours to obtain dispersions W and F having an average particle size of 3 μm.

Capsule liquid of diazo compound obtained as above 5
Coupling component and basic substance dispersion-2≠0 part
1 part and 2 parts of p-benzyloxyphenol dispersion were added to prepare a coating solution. Spread this coating solution on smooth high-quality paper (!0
? /m) using a coating bar to measure dry weight/Q
It was coated at a ratio of 9/rn2 and dried at 2!0C for 30 minutes to obtain a heat-sensitive material.

Comparative Example: A heat-sensitive recording material was obtained in the same manner as in Example, except that N,N'-bis(3-7dinoki/Tλ-hydroxypropyl)pibecillin in Example 1 was changed to triphenylguanidine. .

(Test method) G
■Mode thermal printer (Hifax 700
; made by Hitachi, Ltd.), and then the entire surface was exposed to light using Ricopy Super Dry ioo (made by (2)) and fixed. The blue density of the obtained recorded image was measured using a Macbeth reflection densitometer. In addition, the yellow density of the background portion was also measured in the same manner. On the other hand, when thermal recording was performed again on the fixed portion, no image was recorded and it was confirmed that the image was fixed.

Next, in order to check the raw storage stability, to 0c1 relative humidity 3
The background density (fog) of the heat-sensitive recording material when stored for 2 hours under the conditions of 0 ratio and ti-ooc, relative humidity and 0 ratio, and a xenon long life fade meter (FAL-rrAX/HC type ; Manufactured by Suga Test Instruments) 2
4 was irradiated with light for a period of time and a forced deterioration test was performed, and the yellow density of the background was measured using a Macbeth reflection densitometer to observe changes in the coloration of the background.

Next, in order to investigate the decrease in optical density of the colored part due to long-term storage after thermal recording, the recorded image of the thermal recording material was
After storage in a dark place for 72 hours under the conditions of 0.00 and a forced deterioration test, the degree of decrease in the density of the recorded image was completely evaluated. The results are shown in Table 1.

Table 1 Table 2 summarizes the measurement results for the coloring of the background area.

Example λ Next, an example of a heat-developable thermal copying paper in which the present invention is particularly suitably used will be described in detail below.

The following diazo compound 3. Hiro! (3:/) adduct of xylylene diisocyanate and trimethylolpropane
The r part is tricresyl phosphate,! It was added to a mixed solvent consisting of ≠ part and 5 parts of ethyl acetate, and dissolved by heating. child,
A solution of the diazo compound of 1.2% of polyvinyl alcohol
The part is water! 20°
The mixture was emulsified and dispersed with C to obtain an emulsion with an average particle size of H jμ. Add 700 parts of water to the resulting emulsion and stir until too thick.
C. After 2 hours, a capsule liquid containing a diazo compound in the core material was obtained.

Next, naphthol AS, 2o part and N,N'-bis(3-phenoquine-!-hydroxy/furopyl)pi are 297.2
0 parts were added to ioo parts of a j% polyvinyl alcohol aqueous solution and dispersed in a sand mill for about 2'1 hour to obtain a dispersion with an average particle size of 3 μm.

Diazo compound capsule liquid obtained as above!
A coupling component and a basic substance dispersion part O were added to part O to prepare a coating liquid. Apply this coating solution to smooth high-quality paper (, t
dry weight Ay/m) using a coating par
It was coated to give a heat-sensitive material of 0.0 m and dried for rs0c3o minutes.

Example 3 N,N'-bis(3-phenoxycohydroxypropyl) in Example 2 is syringoN,N'bisC3
A heat-sensitive recording material was obtained in the same manner as in Example λ, except that -(p-methylphenoxy)-northoxypropyl]p was replaced with syringe.

Example ≠ N, N'-bis(3-phenoxy-!-hydroxypropyl) in Example λ is syringoN, N'-bisC3
Example except that -(p-methoxyphenoxy)-2-hydroxypropylcopiperazine was used! A heat-sensitive recording material was obtained in the same manner as above.

Example j N,N'-bis(3-phenoxy-!
-Hydroquinepropyl)pi N, N'his[3-(β-naphthoxy)-2-hydroxypropyl]
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that B was replaced with syringe.

Example B Same as Example 2 except that N,N'-bis(3-phenoquine!-hydroxypropyl)piperazine in Example λ was changed to N,N'bis(3-phenylthio-2-hydroxypropyl)piperazine. A heat-sensitive recording material was obtained.

Synthesis Example/Example/N,N'-bis(3-phenoxy-2-hydroxypropyl)pyhalazine of Example λ was synthesized as follows.

/l of anhydrous pipette in a three-ring flask (7 mol)
was weighed out, 300 ml of ethyl acetate was added thereto, and the mixture was heated and stirred over steam gas to dissolve the anhydrous syringe. About 3 phenyl glycidyl ether 3/ry (2.1 mol)
After dropping for 0 minutes, the mixture was reacted at 7!0C for 2 hours. After the reaction was completed, the mixture was cooled and the white crystals formed were filtered and washed twice with Oml of chilled ethyl acetate. After drying, the target compound was obtained in 3≠7y (yield 0%). Melting point: 1C0 In the above reaction, 2.7 mol of piperazine hydrate (41077), which is widely distributed and inexpensive, is used in place of anhydrous piperazine, and the target compound is obtained in the same yield even if the reaction is carried out in exactly the same manner. It was done.

Synthesis Example 2 N,N'-bisC3-(p-methylphenoxy)-2-hydroxypropyl]P! of Example 3 , Radin was synthesized as follows.

1 (1 mole) of anhydrous pipet and syringe in a 3-L flask.
was weighed out, and methanol was added to dissolve the anhydrous syringe. Epichlorohydrin/9≠7(2
7 mol) was added dropwise at room temperature for about 30 minutes, and then 7 mol was added dropwise at room temperature.
Allowed time to react. Next, p-cresol, t7oy (,!
, r moles) were added over about 3θ minutes, and 10 oy (,!j moles) of sodium hydroxide was further added and reacted at 7°C for 4 hours. After the reaction was completed, cooled, filtered the white crystals produced, and cooled methanol/water (//, ) mixed solvent 100ml
! Washed twice with When dried, the target compound is 2 L
(yield ts%). Melting point //3 °C0 Synthesis Example 3 p-cresol of Synthesis Example 2, 270 ru(,2, tamol)
N, N of Example
'-bis[3-(p-methoxyphenoxy)-λ-hydroxypropyl]pyhalazine was obtained in a yield of 3037 (yield: 2-2). Melting point: 7.23°C0 Synthesis example ≠ Same as Synthesis example 2 except that p-cresol 2707 (2,3 mol) in Synthesis example λ was replaced with β-naphthol 3 oy (,:z, s mol) and N of Example 5, N'-
Bis[3-(β-naphthoxy)-1-hydroxypropyl]piperazine was obtained in 2 pieces (yield to %). Melting point /7 0c0 Synthesis example j N of Example 2 was prepared in the same manner as Synthesis example λ except that p-cresol 27oy (r, s mol) and thiophenol 27sy (, 2, s mol) of Synthesis example λ were changed. .

N'-bis(3-7enylthio-2-hydroxopropyl)pi was obtained with 3y (yield: 70%) of syrin.

Melting point Dos Oco Comparative Example 2 Thermal recording was carried out in the same manner as in Example λ, except that N,N'-bis(3-)futxyλ-hydroxypropyl)pi in Example 2 was replaced with triphenylguanidine. I got the material.

(Test method) The obtained heat-sensitive recording materials of Example λ and Comparative Example 2 were subjected to image exposure using Ricope Sono ξ-Dry 1oo (manufactured by Ricoh ■), and then subjected to /j using a hot plate.

The entire surface was heated for 0 Cs seconds. The blue density of the obtained recorded image was measured using a Macbeth reflection densitometer.

In addition, the yellow density of the background portion was also measured in the same manner.

Next, to check the raw storage stability, to 0c, relative humidity 3
The color density was measured in the same manner after 24 hours of storage under the conditions of relative humidity and humidity of 0 and ≠08C1.

In order to check the fastness of the image to light, the heat-sensitive recording material after recording was coated with xenon long life fade meta (FAL).
, AX-HC type; manufactured by Suga Test Instruments Ltd.) for 2≠ hours, and after performing a forced deterioration test, the image density was measured using a Macbeth reflection densitometer. In addition, in order to check the fastness of the image to temperature and humidity, the heat-sensitive recording material was subjected to RO after recording.
The sample was stored for 2 tons in the dark under conditions of 0C and relative humidity of 5'0%, and the image density was measured after performing a forced deterioration test.

Next, in order to check the coloration of the background, the heat-sensitive recording material after recording was measured using a xenon long-life fade meter (FAL-, AX-H
C type; made by Suga Test Instruments ■),! After ≠time light irradiation and forced deterioration test, the yellow density of the skin was measured using a Magpeth recorder.

Furthermore, in order to observe the coloration of the background due to temperature and humidity after recording, the heat-sensitive recording material was heated to 0% relative humidity at 0°C.
The sample was stored in a dark place for 2 hours under the following conditions, and after a forced deterioration test, the yellow density of the skin was measured using a Macbeth reflection densitometer.

The above results are shown in Table 3! Shown in the table.

Table 3 (color development and raw storage stability) Table 4 (image fastness)

Claims (1)

[Claims] A diazo compound, a coupling component that develops color by coupling with the diazo compound, and a ▲ mathematical formula, chemical formula,
A heat-sensitive recording material characterized by coating a heat-sensitive recording layer containing a basic substance having a partial structure shown in the following table on a support.