Abstract:
A heat-sensitive recording composition containing normally colorless lactones or spiropyran compounds in combination with hydrogen bonded molecular complexes of phenolic compounds having a dissociation temperature ranging from 50° to 220° C. The composition of the invention is less sensitive to pressure and less susceptible to background staining, image flooding, moisture sensitivity, odor, railroading and burnout problems as compared with compositions in which phenolic compounds are not complexed.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a record member which changes or develops color when contacted with heated styluses, heated print heads of thermal printers, or infrared absorbing text when exposed through a thermal copier. 
     Many types of heat sensitive recording materials are well known. This invention is concerned with the improvement of thermal color forming recording materials containing a leuco or colorless form of a dye material and a phenolic material which reacts with the leuco material to form the colored dye. There are many systems of this type represented in the patent literature. 
     References for these systems include: 
     (1) Phthalides, naphthalides, fluorans 
     Typical of these are Crystal Violet Lactone or 3,3-bis-(p-dimethylaminophenyl)-6-dimethylamino phthalide and malachite green lactone or 3,3-bis (p-dimethylaminophenyl) phthalide. The reactions of these and many related phthalides with phenolics are described in Adachi, U.S. Pat. Nos. 3,895,173; Schwab, 3,322,557; Kohmura et al., 3,859,112; Hayashi et al., 3,773,542; Futaki et al., 3,846,153; Baum, 3,539,375; Shimazu, 3,864,684; Adachi et al., 3,843,384; Futaki et al., 3,829,401; Futaki et al., 3,825,432; Higachi, et al., 3,816,838; Nagashima et al., 3,792,481; Blose et al., 3,746,675. 
     Typical examples of the lactones which are listed in the patents as reacting with phenolic materials to produce a color include the following: 
     TABLE I 
     3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide 
     3,3-bis(p-dimethylaminophenylphthalide) 
     3,3-bis p-di(n-butylaminophenyl)phthalide! 
     Rhodamine lactone 
     3- 2-methyl-4-(diethylamino)phenyl!-3-(1,2-dimethyl-3-indolyl)phthalide 
     3-(p-dimethylaminophenyl)-3-(1-ethyl-2-methyl-3-indolyl)-4,5,6,7-tetrachlorophthalide 
     3,3-bis(1-ethyl-2-methylindol-3-yl)phthalide 
     3-(4-morpholinophenyl)-3-(1,2-dimethylindol-3-yl)-4,5,6,7-tetrachlorophthalide 
     3-(1-benzyl-2-methylindol-3-yl)-8-(methyl-2-methylindol-3-yl)phthalide 
     5-nitro-3,3-bis(4-dimethylaminophenyl)phthalide 
     5-amino-3,3-bis(4-dimethylaminophenyl)phthalide 
     5-benzoylamino-3,3-bis-(4-dimethylaminophenyl)phthalide 
     3,3-bis(p-dimethylaminophenyl)-4,5,6,7-tetrachlorophthalide 
     3,3-bis(p-diethylaminophenyl)-6-dimethylaminophthalide 
     3,3-bis(p-dimethylaminophenyl)-6-aminophthalide 
     3,3-bis(p-dimethylaminophenyl)-6-(p-toluenesulfonamide) phthalide 
     3,3-bis(p-dimethylaminophenyl)-6-nitrophthalide 
     3,3-bis(p-dimethylaminophenyl)-6-monethylaminophthalide 
     3,3-bis(p-dimethylaminophenyl)-6-chlorophthalide 
     3,3-bis (p-dimethylaminophenyl)-6-ethoxyphthalide 
     3,3-bis(p-dimethylaminophenyl)-6-diethylaminophthalide 
     3-(4-diethylaminophenyl)-3-(1,2-dimethylindol-3-yl) naphthalide 3-(4-diethylaminophenyl)-3-(1-phenylpyrrol-3-yl) naphthalide 
     3-diethylamino-7-dibenzylaminofluoran 
     3-diethylamino-7-(N-methylanilino)fluoran 
     3-dimethylamino-6-methoxyfluoran 
     3-diethylamino-6-methyl-7-chlorofluoran 
     3-diethylamino-7-phenylfluoran 
     3-morpholino-5,6-benzofluoran 
     7-acetamino-3-dimethylaminofluoran 
     3-dimethylamino-5,7-dimethylfluoran 
     3,6-bis-β-methoxyethoxyfluoran 
     3,6-bis-β-cyanoethoxyfluoran 
     1-amino-3,6,7-trimethylfluoran 
     3-dibutylamino-6-methyl-7-chlorofluoran 
     3-diethylamino-7-dibenzylaminofluoran 
     3-diethylamino-7-(N-methyl-p-toluidino)fluoran 
     3-dimethylamino-7-chlorofluoran 
     3-(diethylamino)-6-methyl-7-anilinofluoran 
     3,7-bis(diethylamino)fluoran 
     3,6-dimethoxyfluoran 
     3-diamylamino-6-chlorofluoran 
     2&#39;,6&#39;-bis(diethylamino)fluoran 
     2&#39;-(benzylamino)-6&#39;-(diethylamino)-3&#39;,4&#34;-benzofluoran 
     3-(ethyl-p-tolylamino)-7-(methylphenylamino)fluoran 
     3-cyclohexylamino-6-chlorofluoran 
     3-diethylamino-5-methyl-7-bis(4-methylbenzyl)aminofluoran 
     3-diethylamino-6-methyl-7-(p-butylanilino)fluoran 
     2&#39;-anilino-6&#39;-diethylamino-3&#39;-methylfluoran 
     3-(diethylamino)-7-(N-methylanilino)fluoran 
     2&#39;-phenylamino-3&#39;-methyl-6&#39;-(N-ethyl-N-p-tolylamino) fluoran 
     3-diethylamino-7-piperidinofluoran 
     3-diethylamino-5-chloro-7-piperidinofluoran 
     3-dimethylamino-5-methyl-7-piperidinofluoran 
     3-diethylamino-5-methyl-7-piperidinofluoran 
     2-(2&#39;,4&#39;,6&#39;-trimethylphenylamino)-8-diethylamino-3,4-benzofluoran 
     2,8-bis(N-ethyl-N-p-tolylamino)-fluoran 
     3-diethylamino-6-methyl-7-o-anisidinofluoran 
     3-(diethylamino)-6,7-dimethylfluoran 
     3-dimethylamino-5-methyl-7- bis-(4-methylbenzyl) amino! fluoran 
     4-amino-8  bis-β-ethoxyethyl)amino! benzofluoran 
     N,n&#39;-bis (3&#39;-diethylaminofluoran-7&#39;yl) piperazine 
     2-phenylamino-6-diethylaminofluoran 
     2-phenylamino-6-dimethylaminofluoran 
     3&#39;-diethylamino-7&#39;-methylthiofluoran 
     3,7-bis (diethylamino)-5,6-benzofluoran 
     3-dimethylamino-7-benzylamino-5,6-benzofluoran 
     3-diethylamino-7-(N-benzyl-N-phenyl)aminofluoran 
     3-benzylamino-7-diethylaminofluoran 
     2&#39;-(p-chloroanilino)-6&#39;-diethylaminofluoran 
     2&#39;-(m-chloroanilino)-3-methyl-6&#39;-diethylaminofluoran 
     2&#39;-(p-chloro-N-methylanilino)-6&#39;-diethylaminofluoran 
     3-(diethylamino)-5-methyl-7-(β-phenylhydrazino)fluoran 
     3-(diethylamino)-7-bis(1-naphthylmethyl)aminofluoran 
     3-(diethylamino)-7-(2-phthalimidino)fluoran 
     3-diethylamino)-6-methyl-3&#39;-azafluoran 
     3 -diethylamino-5-methyl-7-(diphenylamino)fluoran 
     3-(dimethylamino)-7-(diphenylmethylamino)fluoran 
     3-(diethylamino)-6-methyl-7-(p,p&#39;-dimethyldiphenylmethyl)amino fluoran 
     3-(dibutylamino)-7-(diphenylmethylamino)fluoran 
     3-(diethylamino)-7-(β,β-dibenzylhydrazino)fluoran 
     3-(dimethylamino)-7-(p-methoxybenzamido)fluoran 
     7-anilino-3-(diethylamino)fluoran 
     2&#39;-(methylphenylamino-6&#39;-(methyl-p-tolylamino)fluoran 
     2&#39;-methyl-6&#39;-cyclohexylaminofluoran 
     2&#39;-amino-6&#39;-diethylamino-3&#39;-methylfluoran 
     2&#39;-amino-6&#39;-diethylaminofluoran 
     2&#39;-(2-carboxyanilino)-6&#39;-diethylaminofluoran 
     3-dibenzylamino-7-diethylaminofluoran 
     2&#39;- N-(carboethoxymethyl)amino!-6&#39;-diethylaminofluoran 
     2&#39;- N-(carbethoxymethyl)-N-methylamino!-6&#39;-diethylaminofluoran 
     Rhodamine lactam 
     N-phenyl Rhodamine lactam 
     Rhodamine anilino lactam 
     9-p-nitroamino-3,6-bis(diethylamino)-9-Xanthenoyl-6-benzoic acid lactam 
     9-p-nitroamino-3,6-bis(dimethylamino)-9-thioxanthenoyl-6-benzoic acid lactam 
     (2) Spiropyrans 
     The following are some of the patents which list typical spiropyrans giving a color when reacted with phenolic materials: Talvakar, U.S. Pat. Nos. 3,445,261; Futaki et al., 3,829,401; Kohmura et al., 3,859,112; Hayashi et al., 3,773,542; Kimura et al., 3,666,525; Yahagi et al., Japanese Pat. No. 73-63,734; Futaki et al., Germany Pat. No. 2,252,845; Komura et al., German Pat. No. 2,327,135; Takamizawa et al., Japanese Patent No. 74-00,069; Robillard et al., French Pat. No. 2,204,151; Haino et al., Japanese Pat. No. 75-01,746; Samat et al., German Pat. No. 2,522,877; Miyazawa et al., Japanese 75-137,146; Takimoto et al., Japanese Pat. No. 75-152,742; Futaki et al., German Pat. No. 2,252,845; Miyazawa et al., Japanese Pat. No. 75-137,549. 
     Typical examples of the spiropyrans listed in the patents as reacting with phenolic materials to yield colored dyes include: 
     TABLE II 
     6&#39;-chloro-8&#39;-methoxybenzoindolinospiropyran 
     benzothiazolinospiropyran 
     benzo-β-naphthospiropyran 
     3-methyl-di-β-naphthospiropyran 
     1,3,3-trimethyl-6&#39;-chloro-8&#39;-methoxyindolinobenzospiropyran 
     6&#39;chloro-8&#39;-methoxyindolinobenzospiropyran 
     6-chloro-8-methoxy-1&#39;,3&#39;,3&#39;-trimethylspiro(1-benzopyran-2,2&#39;-indoline) 
     spiro (1-benzopyran-2,2&#39;-naphthopyran) 
     8&#39;-methoxybenzoindolinospiropyran 
     1,3,3-trimethyl-4,7,8&#39;-trimethoxy  (2&#39;H-1&#39;-benzopyran)-2,2&#39;-indoline! 
     6-chloro-8&#39;-methyl-1,3,3-trimethylbenzoindolinospiropyran 
     2-ethyl-3,3&#39;-spirobinaphthopyran 
     3-phenyl-di-β-naphthospiropyran 
     di-62 -naphthospiropyran 
     3-ethyl-di-β-napththospiropyran 
     3,3&#39;-dichlorospirodinaphthopyran 
     1,3,3-trimethyl-6&#39;-nitrospiro(2&#39;H-1&#39;-benzopyran-2,2&#39;-indoline) 
     1,3,3-trimethyl-8&#39;-nitrospiro(2&#39;H-1&#39;-benzopyran-2,2&#39;-indoline) 
     1,3,3-trimethyl-6&#39;-nitro-8&#39;-methoxyspiro(2&#39;H-1&#39;-benzopyran-2,2&#39;-indoline) 
     1,3,3-trimethyl-5&#39;-nitro-8&#39;-methoxyspiro(2&#39;H-1&#39;-benzopyran-2,2&#39;-indoline) 
     3,7-bis(3&#39;,6&#39;-dimethoxy-9&#39;-spiroxanthyl) pyromellitide 
     Typical examples of phenolic materials listed in the patent literature as reacting with the leuco compounds such as the phthalides, naphthalides, fluorans, and spiropyrans to form colored dyes include: 
     TABLE III 
     4,4&#39;-isopropylidene diphenol 
     4,4&#39;-isopropylidene-bis(2-methylphenol) 
     4,4&#39;-isopropylidene bis(2-phenylphenol) 
     4,4&#39;-isopropylidene-bis(2-t.butylphenol) 
     4,4&#39;-sec.butylidene-diphenol 
     4,4&#39;-sec.butylidene bis (2-methylphenol) 
     4,4&#39;-cyclohexylidene diphenol 
     4,4&#39;-cyclohexylidene-bis(2-isopropylphenol) 
     4,4&#39;-ethylidene-diphenol 
     2,2&#39;-methylenebis (5-methylphenol) 
     4,4&#39;-ethylidene bis(2-methylphenol) 
     4,4&#39;-(1-methylpentylidene)diphenol 
     4,4&#39;-(methylisopentylidene)diphenol 
     4,4&#39;-(1-methylhexylidene)diphenol 
     4,4&#39;-(1-ethylbutylidene)diphenol 
     4,4&#39;-(ethylpropylidene)-bis(2-methylphenol) 
     4,4&#39;-isopropylidenedicatechol 
     4,4&#39;-benzylidene-diphenol 
     4,4&#39;-isopropylidene-bis(2-chlorophenol) 
     2,2&#39;-dihydroxydiphenyl 
     2,2&#39;-methylenebis (4-chlorophenol) 
     2,2&#39;-methylene bis(4-methyl-6-t.butylphenol) 
     2,2&#39;-methylene bis (4-methyl-6-t.butylphenol) 
     4,4&#39;-isopropylidene bis (2,6-dimethyl phenol) 
     2,2&#39;-thiobis (4,6-dimethylphenol) 
     4,4&#39;-ethylene diphenol 
     4,4&#39;-(1-methylbenzylidene)diphenol 
     4-t. butylphenol 
     4-phenylphenol 
     α-naphthol 
     β-naphthol 
     hydroquinone 
     pyrocatechol 
     pyrogallol 
     phloroglucine 
     m. cresol 
     There are a number of commercial products which use the above-described combinations of leuco dyes and phenolic derivatives. These have found applications in thermal copying paper using 3M&#39;s Thermofax and other models of thermal copiers. Thermally responsive sheets using these materials have also been used with computer-driven thermal printers such as Texas Instrument&#39;s Silent 700 Thermal Printer. Sensitized papers containing a combination of leuco dyes and phenolic materials are used in chart recording instruments wherein a colored trace record is obtained by contacting the paper with a hot pen or stylus. There are certain inherent disadvantages found with the leuco dye-phenolic combinations. Complaints are received on background staining, fading of the record mark, flooding of the image, moisture sensitivity, odor, pressure sensitivity causing accidental marking by paper clips and the like, railroading (developing two bars or streaks on the path made by a hot stylus), and burnout on chart recording papers. Many of the phenolic materials described in the patents are toxic or irritating and cannot be used. These same leuco dye-phenolic color-forming systems are used in the &#34;carbonless&#34; pressure marking papers and the reactants are kept separate by microencapsulation or by being contained in separate layers. Pressure contact of these materials results in dye formation. This property is also inherent in the thermal papers and excess pressure will cause accidental marking. Also, for this same reason, the reactants must be ground separately and a solvent or resin binder-solvent combination which will dissolve or partially dissolve one or both of the co-reactants will result in premature dye formation in the coating mix. The object of this invention is to eliminate or minimize the problems incurred with the leuco dye-phenolic thermal color-reacting systems. Another objective is to minimize the sublimation or migration of the phenolic material which has caused problems with staining and change in sensitivity. Still another objective is the manufacture of thermal record sheets with improved image sharpness and definition. 
     SUMMARY OF THE INVENTION 
     I have found that the above objectives can be obtained by combining a leuco dye lactone or spiropyran with a phenolic material which has been inactivated by complexing. More specifically, the phenolic material is incorporated as the solid, particulate hydrogen bonded molecular complex of an amine or amide. The phenolic hydroxyls are non-reactive in the hydrogen bonded form, but become active and enter into a color-forming reaction with the leuco dye or dye precursor when heated to a temperature sufficient to dissociate the hydrogen bonded molecular complex into its original components. The complex can be dissociated by heat or by solution in a solid polar material when it is melted. The dissociation temperature of the complex can range from 50° to 220° C, but remains in a stable, unreactive form below 50° C. 
     Certain additives may be used with the recording composition of the invention to lower the temperature of color formation and to increase the intensity of color. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Preparation of Complexes 
     The phenolic material is dissolved in anhydrous methanol or ethanol to form a 25 percent solution. The hydrogen bonding co-reactant amine or amide is added to the alcoholic solution of the phenolic derivative in molecular equivalents corresponding to the functional hydroxyl groups in the phenolic compound. For example, two moles of cyclohexylamine are added to one mole of a bis-phenol, one mole of amine is added to one mole of a mono-hydroxy compound, etc. The mixtures are stirred for a few minutes until they become homogeneous. In some cases, a solid complex will form and precipitate almost immediately, while others must be chilled in a cold box before solid products are obtained. The mixture containing the precipitated complex is then filtered and the precipitate is washed with alcohol and allowed to dry. The following table (Table IV) contains a number of hydrogen-bonded phenolic complexes which have been prepared in this manner. 
     Preparation of Coatings 
     The phenolic hydrogen bonded complexes are dispersed in a solution of a binder and ball-milled or otherwise comminuted until a fine particle size, preferably below 10 microns, is obtained. Any solvent-binder system may be used which does not dissolve and dissociate the phenolic complex. Some suitable systems include water solutions of polyvinyl alcohol, hydroxyethyl cellulose, and other common water-soluble polymeric resins. Methanol or ethanol solutions of nitrocellulose, ethylcellulose, and other alcohol-soluble resins can be used. 
     
                                           TABLE IV__________________________________________________________________________AROMATIC HYDROXY COMPLEXESPhenol        Amine         Dissociation Temp.° C__________________________________________________________________________p,p&#39; biphenol ethylene diamine 136-140&#34;             t.butyl amino ethyl         methacrylateBisphenol B   ethylenediamine   85-92&#34;             formamide         64-66&#34;             t.butyl aminoethyl         methacrylate      94-64,4&#39;-isopropylidene bis(2-isopropylphenol)         triethanolamine   60-63&#34;             ethylene diamine 100-44,4&#39;-isopropylidene bis(2,6-dibromophenol)         diethanol amine  107-145&#34;             triethanolamine  128-157&#34;             ethylene diamine 198-215&#34;             diethylenetriamine                          210-215&#34;             propylene diamine                          146-156&#34;             formamide         95-102&#34;             hydrazine        135-150&#34;             t.-butyl aminoethyl         methacrylate     130-54-hydroxy propiophenone         hydrazine         84-902,4-dichloro-6-phenylphenol         ethyleneiamine   100-4&#34;             diethylenetriamine                          115-20&#34;             propylenediamine  92-42,2&#39;-methylenebis(3,4,6-trichlorophenol) -(Hexachlorophene)         diethanolamine    75-8&#34;             triethanolamine  118-23&#34;             ethylenediamine  124-7&#34;             diethylenetriamine                           90-110&#34;             propylene diamine                          125-30&#34;             formamide        125-30&#34;             hydrazine        180-4         t-butylamine ethyl         methacrylate     123-62-bromo-4-phenyl phenol         ethylenediamine   66-8&#34;             diethylene triamine                           78-82&#34;             formamide         55-8p-phenyl phenol         ethylene diamine 137-43&#34;             diethylene triamine                           99-104&#34;             propylene diamine                           77-81&#34;             formamide         90-5&#34;             hydrazine        145-1502,2&#39;-thiobis(4,6-dichlorophenol)(Actomer)     triethanolamine  120-5&#34;             ethylene diamine 125-130&#34;             diethylene triamine                          158-164&#34;             propylene diamine                          142-5&#34;             formamide        115-25&#34;             hydrazine        195-2004,4&#39; isopropylidenebis(2,6-dichlorophenol)(Tetrachlorobisphenol A)         ethylenediamine  192-5&#34;             diethylene triamine                          210-15&#34;             propylene diamine                          170-5&#34;             formamide        100-5&#34;             hydrazine        142-6&#34;             t-butyl amine ethyl         methacrylate     132-55-chloro-2-hydroxybenzophenone  ethylene diamine 190-4o-phenylphenol (Dowicide 1)         ethylene diamine  55-60&#34;             formamide         50-3&#34;             hydrazine         60-4Dichlorophene formamide         90-32,2&#39;-methylenebis(4-ethyl-6-t.butylphenol)(Antioxidant 425)         triethanolamine   68-70Bisphenol A   ethylene diamine 100-4&#34;             propylene diamine                           94-100&#34;             t-butylamine ethyl         methacrylate      90-24,4&#39;-thiobis(6-t.butyl-m-cresol)(Santowhite crystals)         triethanolamine   95-8&#34;             ethylene diamine 106-11&#34;             propylene diamine                          125-35&#34;             t.butylamine ethyl         methacrylate       62-54,4&#39;-butylidenebis(6-t.butyl-m-cresol)(Santowhite Powder)         triethanolamine   68-702,2&#39;-methylenebis(4-methyl-6-t.butylphenol)(Antioxidant 2246)         diethanolamine    62-5&#34;             ethylene diamine  54-8p-cyclohexyl phenol         triethanolamine   35-40&#34;             ethylene diamine 125-30&#34;             diethylene triamine                           70-85&#34;             propylene diamine                           88-90o-cyclohexyl phenol         ethylene diamine  88-93&#34;             hydrazine         75-80p-t.butyl phenol         ethylene diamine  70-3&#34;             propylene diamine                           54-7p.-sec. butyl phenol         ethylene diamine  50-4p-bromophenol formamide         35-82,4,6-tribromophenol         ethylenediamine  135-8&#34;             propylenediamine  85-9&#34;             formamide         90-3pentachlorophenol         diethanolamine   145-55&#34;             triethanolamine  133-7&#34;             ethylenediamine  115-20&#34;             diethylenetriamine                          185-90&#34;             propylene diamine                          168-72&#34;             formamide        100-5&#34;             hydrazine        200-5&#34;             t-butyl amine ethyl         methacrylate     115-202,6-dichlorophenol         triethanolamine   83-6&#34;             ethylene diamine 110-15&#34;             propylenediamine 100-155&#34;             formamide         40-5&#34;             hydrazine        115-20&#34;             t.butyl amine ethyl         methacrylate     100-52-chloro-4-phenyl phenol         ethylene diamine 130-5&#34;             propylene diamine                            50-4&#34;             hydrazine        108-12tetrachlorophenol (Dowicide 6)         diethanolamine   110-25&#34;             triethanolamine   98-104&#34;             ethylene diamine 192-5&#34;             propylene diamine                          165-70&#34;             formamide         85-90&#34;             hydrazine        163-5         t.-butyl amino ethyl         methacrylate      95-1002,4,6-trichlorophenol         ethylene diamine 105-14&#34;             propylene diamine                          100-5&#34;             formamide         85-90&#34;             hydrazine        150-7&#34;             t.-butyl amine ethyl         methacrylate      70-5β-β-ethylenediimino-o-cresol         formamide        105-10&#34;             t.butylamine ethyl-         methacrylate     118-12Bisphenol A   benzylamine       70-44,4&#39;-isopropylidenebis(2,6-dibromophenol)(Tetrabromobisphenol A)         2-amino-1-butanol                          155-62&#34;             aminoethylenethanolamine                           74-85&#34;             2-amino-2-ethyl-1,         3-propenediol    130-40&#34;             2-amino-2-methyl-1,         3-propeneiol     154-60&#34;             aminoethyl piperazine                          140-50         2-amino-2-methyl-1-propanol                          180-90&#34;             2-amino-1-phenyl-1-propanol                          100-30&#34;             3-amino propanol 190-5&#34;             benzylamine      144-8&#34;             chloroacetamide  114-22&#34;             3-chloro-N-methyl-         acetamide         80-5Tetrabromobisphenol A         n-decylamine     170-90&#34;             1,3-diamino propane                          218-225&#34;             3-di-n-butyl amino         propylamine      150-8&#34;             diethanolamine   140-3&#34;             diethyl amino ethoxy         ethanol          180-5&#34;             diethylamino propylamine                          175-85&#34;             N-diethyl amino propyl-1-         methyloctadecylamine                           88-100&#34;             diethylisopropanolamine                          135-42&#34;             diisopropanolamine                           65-75&#34;             diisopropylethanolamine                          158-165&#34;             dimethylacetamine                           95-100&#34;             dimethylamino propylamine                          198-202&#34;             dimethylethanolamine                          135-45&#34;             dimethylformamide                           60-5&#34;             N-(1,1-dimethyl-2-hydroxy         ethyl)-2-methyl 1-1, 2-         Propane diamine  130-40Tetrabromobisphenol A         t.-dodecylaminopro-         pylamine          90-105&#34;             ethanolamine     170-80&#34;             N-ethylethanolamine                           90-100&#34;             N-ethyldiethanolamine                          137-42&#34;             hexamethyl phosphoramide                          127-30&#34;             n-hexylamine     200-10&#34;             hydroxyethyl diethylene         triamine          60-80&#34;             N-2-hydroxyethyl-1-methyl         dodecylamine     100-110&#34;             N-hydroxyethyl piperazine                          190-200&#34;             hydroxy ethyl trihydroxy         propyl-ethylene diamine                           45-55&#34;             iminobispropylamine                          210-20&#34;             isobutylamine    160-70&#34;             isopropylamine   165-75&#34;             3-isopropoxypropanolamine                          165-75&#34;             isopropylamine   160-70&#34;             methanediamine   140-5&#34;             methyldiethanolamine                          132-6&#34;             methyl ethanol amine                          143-6&#34;             N-methyl-bis-amino         propylamine      210-20&#34;             polyglycol amine H-119                          115-20&#34;             polyglycolamine H-176                          195-205&#34;             polyglycolamine H-221                          165-174&#34;             1,2-propanediamine                          150-160&#34;             propylenediamine 148-155&#34;             tetramethylethylene-         diamine          190-200&#34;             tetramethylguanidine                          225-235&#34;             triethanolamine  154-8&#34;             triethylene tetramine                          200-15&#34;             triisopropanolamine                          135-9p,p&#39;-biphenol hexamethyl phosphoramide                           40-504-hydroxy propiophenone         hydrazine         84-902,2&#39;-methylene bis         aminoethylethanolamine                          165-7(2,4,6-trichlorophenol)         2-amino-2-ethyl-1,3-         propanediol      151-70&#34;             2-amino-2-methyl-1,3-         propanediol      182-4&#34;             benzylamine      210-16         t-butylaminoethyl&#34;             methacrylate     123-6&#34;             diethanolamine    75-8&#34;             diethylenetriamine                           90-1102,2&#39;-methylene bis (2,4,6-trichlorophenol)         dimethylethanolamine                          183-93&#34;             N-ethyldiethanolamine                          124-7&#34;             ethylene diamine 187-92&#34;             formamide        125-30&#34;             hexamethyl prosphoramide                           85-90&#34;             hydrazine        180-4&#34;             N-methylbisamino         propylamine      157-65&#34;             methyldiethanolamine                          154-72,2&#39;-methylene bis (2,4,6-trichlorophenol)         methylethanolamine                          193-200&#34;             polyglycolamine H-1/4                          208-24&#34;             propylenediamine 135-40&#34;             triethanolamine  142-62,4-dichloro-6-phenyl phenol         diethylene triamine                          115-20&#34;             ethylene diamine 100-4&#34;             propylenediamine  92-42-bromo-4-phenyl phenol         benzylamine       85-95&#34;             diethylenetriamine                           78-82&#34;             ethylenediamine   66-8&#34;             formamide         55-8&#34;             hydrazine         82-8p-phenyl phenol         benzylamine       70&#34;             diethlenetriamine                           99-104&#34;             ethylenediamine  137-43&#34;             formamide        113-5&#34;             hexamethyl phosphoramide                           34-5&#34;             hydrazine        155-8&#34;             propylene diamine                           71-81&#34;             triethylene tetramine                           63-52,2&#39;-thiobis (4,6-dichlorophenol         2-amino-2-ethyl-1,         3-propanediol    125-59&#34;             benzylamine      197-9&#34;             diethanolamine   143-7&#34;             diethylene triamine                          158-74&#34;             dilosopropanolamine                          155-62&#34;             dimethylacetamide                          190-3&#34;             dimethylethanol amine                          120-3&#34;             N-ethyldiethanolamine                          127-30&#34;             ethylene diamine 125-30&#34;             hydrazine        195-200&#34;             iminobispropylamine                           50-74&#34;             methyldiethanolamine                          127-40&#34;             polyglycolamine H-176                          210-14&#34;             propylene diamine                          142-5&#34;             formamide        115-25&#34;             triethanolamine  165-8&#34;             triisopropanolamine                          151-52,2&#39; methylene bis (4-chlorophenol) benzylamine       60-100&#34;             formamide         90-34,4&#39;-isopropylidene bis(2,6-dichlorophenol)         2-amino-1-butanol                          166-70&#34;             aminoethylethanolamine                          154-8&#34;             2-amino-2-ethyl-1,2-         propanediol      166-8&#34;             2-amino-2-methyl-1, 3-         propanediol      172-5&#34;             3-amino propanol 180-90&#34;             amylamine        200-10&#34;             aniline           90-6&#34;             benzylamine      145-554,4&#39;-isopropylidene bis(2,6-dichlorophenol)         t.butylaminoethyl         methacrylate     132-5&#34;             cyclohexylamine  190-204&#34;             n-decylamine     193-8&#34;             1,3-diamino propane                          230-5&#34;             dibutylamine     124-57&#34;             3-di-n-butylamine         propylamine      155-64&#34;             dibutylmethylamine                          120-31&#34;             dicyclohexylamine                          202-6&#34;             diethanolamine   150-3&#34;             diethylamine     142-7&#34;             diethylaminoethyl&#34;             methacrylate     115-7         β-diethylaminopro-         pionitrile        94-6&#34;             3-ethylamino propionitrile                          103-5&#34;             di-2-ethylhexylamine                          100-5&#34;             diethylene triamine                          210-15&#34;             diethylisopropanolamine                          125-35&#34;             diisopropylethanolamine                          162-4&#34;             diisopropylamine 141-52&#34;             β-dimethylamino propio-         nitrile           70-3&#34;             dimethylaminopropylamine                          197-203&#34;             dimethylethanolamine                          140-6&#34;             di-n-propylamine 142-53&#34;             3-t.-dodecylaminopropy-         lamine           100-5&#34;             ethanolamine      96-104&#34;             N-ethylcyclohexylamine                          161-78&#34;             N-ethyldiethanolamine                          154-5&#34;             ethylene diamine 208-10&#34;             N-ethylethanolamine                           87-110&#34;             formamide        103-8&#34;             hexamethylphosphoramide                          122-4&#34;             n-hexylamine     168-85&#34;             hydrazine        142-6&#34;             hydroxyethylethylene         diamine           94-100&#34;             iminobispropylamine                          220-3&#34;             isobutylamine    152-67&#34;             isodecylamine    187-95&#34;             isooctylamine    172-84&#34;             isopropanolamine 150-7&#34;             3-isopropoxyisopropanol-         amine            160-7&#34;             β-isopropylaminopro-         pionitrile       103-7&#34;             3-isopropylamine pro-         pylamine         122-7&#34;             isoquinoline     102-4&#34;             2,6-lutidine     125-32&#34;             methanediamine   186-90&#34;             N-methyl bis amino         propylamine      219-364,4&#39;-isopropylidene bis(2,6-dichlorophenol)         methylaminopropylamine                          207-13&#34;             methylbenzylamine                          145-55&#34;             N-methyldiethanolamine                          148-52&#34;             N-methylethanolamine                           85-102&#34;             3,3&#39;-methyl iminobis         propylamine      190-9&#34;             N-methyl morpholine                          120-4&#34;             N-methyl-2-pyrrolidone                           70-3&#34;             morpholine       159-60&#34;             phenyldiethanolamine                           85-95&#34;             phenylethanolamine                           88-95&#34;             2,2&#39;-phenyliminodiethano-         lamine            55-70&#34;             γ-picoline  96-9&#34;             polyglycolamine H-119                          156-63&#34;             polyglycolamine H-169                          123-33&#34;             polyglycolamine H-176                          210-18&#34;             polyglycolamine H-221                          196-200&#34;             propylenediamine 168-75&#34;             pyridine         117-30&#34;             tetraethylene pentamine                           92-102&#34;             tributylamine    103-8&#34;             triethylamine    155-64&#34;             triethanolamine  139-45&#34;             triethylene tetramine                          215-20&#34;             triisopropanolamine                          125-30&#34;             trimethylenediamine                          230-5&#34;             dimethylacetamide                          1325-chloro-2-hydroxy benzo-phenone       ethylenediamine  190-42,2&#39;-methylene bis (4-ethyl6-dibutyl phenol)         benzylamine       76-85&#34;             triethanolamine   68-70o-phenyl phenol         ethylenediamine   55-60&#34;             formamide         50-3&#34;             hydrazine         60-44,4&#39;-isopropylidene bisphenol         benzylamine       80-90&#34;             t-butylaminoethyl-         methacrylate      90-2&#34;             cyclohexylamine  108-10&#34;             dibutylamine     120-52&#34;             diethylamine     117-53&#34;             dimethylamine         propylamine      105-8&#34;             di-n-propylamine  90-100&#34;             ethylenediamine  100-4&#34;             formamide         66-8&#34;             isobutylamine     88-93&#34;             methanediamine   128-30&#34;             N-methyliminobis-         propylamine       94-8&#34;             propylenediamine  95-100&#34;             triethylenetetramine                          137-94,4&#39;-thiobis (6-t.butyl-m-cresol)     t.butylamino ethyl         methacrylate      62.5&#34;             cyclohexylamine   78-85&#34;             ethylenediamine  112-15&#34;             iminobispropylamine                           85-95&#34;             isopropylamine   164-6&#34;             propylenediamine 130-6&#34;             pyridine         160-5&#34;             triethanolamine   95-84,4&#39;-butylidene bis(m-cresol)    acetamine         82-3&#34;             benzylamine      135&#34;             cyclohexylamine  214-7&#34;             ethylenediamine  213-7&#34;             triethanolamine   68-702,2&#39;-methylene bis (4-methyl-6-t.butylphenol)         2-amino-1-butanol                           58-64&#34;             benzylamine       69-79&#34;             decylamine        52-3&#34;             1,3-diaminopropane                           50-5&#34;             N-dibutylethylamine                           60-5&#34;             diethanolamine    62-5&#34;             di-n-hexylamine   81-9&#34;             ethyl cyclohexylamine                           92-4&#34;             N-ethyl diethanolamine                           68-71&#34;             isopropylaminoiso-         propylamine      128-32&#34;             ethylene diamine  54-8&#34;             hexamethyl phosphoramide                           58-65&#34;             isoquinoline     121-5&#34;             N-methyldiethanolamine                          127-34&#34;             methyl ethanolamine                           74-84&#34;             triamylamine      65-75&#34;             triethanolamine   61-5p-cyclohexyl phenol         triethanolamine   35-40&#34;             benzylamine       50-5&#34;             diethylenetriamine                           70-85&#34;             ethylene diamine 125-30&#34;             hexamethyl phosphoramide                           97-109&#34;             hydrazine        115-20&#34;             propylene diamine                           88-90o-cyclohexyl phenol         benzylamine       82-95&#34;             ethylene diamine  88-93&#34;             hydrazine         75-80p.t.-butyl phenol         benzylamine       70-80&#34;             ethylenediamine   70-3&#34;             hydrazine         45-50&#34;             propylenediamine  54-6p-bromophenol formamide         35-82,4-dibromophenol         benzylamine       80-52,4,6-tribromophenol         t.butyl amino ethyl         methacrylate      68-71&#34;             benzylamine      125-30&#34;             ethylene diamine 135-8&#34;             formamide         90-3&#34;             hydrazine        145-54&#34;             propylene diamine                           87-92Pentachlorophenol         benzylamine      155-60&#34;             t.-butylaminoethyl         methacrylate     115-20&#34;             diethanolamine   145-55&#34;             diethylenetriamine                          185-90&#34;             ethylenediamine  115-20&#34;             formamide        100-105&#34;             hexamethyl phosphoramide                           79-83&#34;             hydrazine        200-205&#34;             propylenediamine 168-72&#34;             triethanolamine  133-72,6-dichlorophenol         benzylamine      100-5&#34;             t.butylaminoethyl         methacrylate     100-5&#34;             diethanolamine    83-6&#34;             ethylenediamine  110-15&#34;             formamide         40-5&#34;             hydrazine        115-20&#34;             propylenediamine 115-252-chloro-4-phenyl phenol         benzylamine       95-100&#34;             ethylenediamine  130-5&#34;             hydrazine        108-12&#34;             propylenediamine  50-4tetrachlorophenol         benzylamine      115- 25&#34;             t.butylaminoethyl         methacrylate      95-100&#34;             diethanolamine   110-25&#34;             ethylenediamine  192- 5&#34;             formamide         85-90&#34;             hydrazine        163-5&#34;             propylenediamine 165-70&#34;             triethanolamine   98-1042,4,6-trichlorophenol         benzylamine      120-5&#34;             t.butylaminoethyl         methacrylate      70-5&#34;             ethylenediamine  105-14&#34;             formamide         85-90&#34;             hydrazine        150-7&#34;             propylenediamine 100-52,4-dichloro-1-naphthol         benzylamine       55-60&#34;             diethanolamine    65-70&#34;             diethylenetriamine                           79-83&#34;             formamide         78-82&#34;             hydrazine         83-93&#34;             triethanolamine   63-52-naphthol    benzylamine       40-5&#34;             ethylenediamine   86-9&#34;             formamide         56-59&#34;             hydrazine        110-124,4-isopropylidene bis(p-chlorophenol)         benzylamine      105-10&#34;             formamide         55-60&#34;             hexamethyl phosphoramide                           46-8&#34;             hydrazine        100-1122,6-dibromo-t.butyl phenol         benzylamine       75-80&#34;             diethylenetriamine                           85-96&#34;             ethylenediamine   95-105&#34;             hydrazine        105-110&#34;             propylenediamine  95-100&#34;             triethanolamine  104-6phenol        ethylenediamine   56-62&#34;             hydrazine          48-562,4,5-trichlorophenol         benezylamine     118-20&#34;             t.butylaminoethyl         methacrylate      55-60&#34;             diethanolamine1,1-di 10&#34;             diethylenetriamine                           85-95&#34;             ethylenediamine   55-60&#34;             hydrazine         94-100&#34;             propylenediamine  96-1041,1-di (4-hydroxyphenyl)cyclohexane   diethanolamine   100-112&#34;             propylenediamine 120-51,1-di (3,5-dibromo-4-hydroxy phenyl) cyclohexane         diethanolamine   149-54&#34;             propylenediamine 175-803,3-bis (3,5-dibromo-4-hydroxy phenyl) pentane         propylenediamine 183-922,2-bis (3,5-dibromo-4-hydroxy phenyl) pentane         diethanolamine   110-18&#34;             propylenediamine 180-90bis (3,5-dibromo-4-hydroxy phenyl) methane         diethanolamine   115-232,2-bis (3,5-dibromo-4-hydroxy phenyl) butane         diethanolamine   142-5&#34;             propylenediamine 174-63,3&#39;-5,5&#39;-tetrabromo-4,4&#39;-dihydroxy biphenyl         diethanolamine   173-80&#34;             propylene diamine                          180-21-phenyl-1, 1-di (3,5-di-bromo-4-hydroxy phenyl)ethane        diethanolamine   145-50&#34;             propylenediamine 185-2002,2-di (3,5-dibromo-4-hydroxyphenyl) 4-methyl-penetane      diethanolamine   115-20&#34;             propylenediamine 190-42,2-di (3,5 dibromo-4-hydroxy phenyl) heptane         diethanolamine   145-50&#34;             propylenediamine 195-71,1-i (3,5-dibromo-4-hydroxy phenyl) butane         diethanolamine   100-15&#34;             propylene diamine                          173-72,2-di (3,5-dibromo-4-hydroxy phenyl) octane         diethanolamine   140-21,l-di (3,5-dibromo-4-hydroxy phenyl) ethane         diethanolamine   105-10&#34;             propylenediamine 175-82,4-dihydroxybenzophenone         propylenediamine 212-183,5-dichlorosalicylaldehyde         diethanolamine   100-5&#34;             hexamethyl phosphoramide                           70-84&#34;             propylenediamine 135-45bisphenol A disalicylate         diethanolamine   150-5&#34;             propylenediamine 155-75tetrachlorohydroquinone         diethanolamine   146-50&#34;             propylene diamine                          175-802-hydroxy-5-phenyl-propiophenone propylenediamine 180-52,4,6-tribenzoyl resorcinol         diethanolamine   125-30&#34;             propylenediamine over 2803,5-dibromosalicylaldehyde         diethanolamine    90-8&#34;             hexamethylphosphoramide                           83-95&#34;             propylenediamine 150-22-isopropyl-4,6-dinitro-phenol        diethanolamine   105-10&#34;             propylenediamine 188-903,4,6-trichloro-2-nitrophenol        diethanolamine 146-50&#34;             propyleneiamine  185-901,1-methylenebis-2-naphthol         diethanolamine   135-40&#34;             hexamethylphosphoramide                          142-4&#34;             propylenediamine 160-51,1-di-2-naphthol         diethanolamine   158-74&#34;             hexamethylphosphoramide                          112-20&#34;             propylenediamine 120-301,1-thio bis (2-naphthol)         diethanolamine   135-42&#34;             hexamethyl phosphoramide                          124-8&#34;             propylenediamine 120-5p-chlorotrisphenol         diethylene triamine                          132-8&#34;             hexamethylphosphoramide                          149-511,1-bis (3,5-dichloro-4-hydroxyphenyl) cyclohexane         benzylamine      144-521,1-bis (3,5-dichloro-4-hydroxy phenyl) cyclohexane         diethanolamine   140-3&#34;             diisopropyl ethanolamine                          164-8&#34;             dimethyl ethanolamine                          169-85&#34;             methyl diethanolamine                          131-9&#34;             methyl ethanolamine                          165-71&#34;             polyglycolamine H-176                          192-200pentabromophenol         aminoethylethanolamine                          131-3&#34;             2-amino-2-methyl-1,3-         propanediol      170-9&#34;             benzylamine      155-8&#34;             diethanolamine   158-61&#34;             diisopropanolamine                          178-37&#34;             diisopropylethanolamine                          130-3&#34;             N-ethyldiethanolamine                           93-8&#34;             methyl diethanolamine                          120-3&#34;             methyl ethanolamine                          163-5&#34;             triethanolamine  129-34hydroquinone  acetamide         99-105&#34;             formamide         63-5&#34;             morpholine        64-8&#34;             piperazine       187-95resorcinol    hydrazine         48-55&#34;             piperazine       147-52pyrogallol    formamide         55-8&#34;             acetamide         58-65__________________________________________________________________________ 
    
     Likewise, hydrocarbon solutions of styrene polymers or copolymers, acrylate or methacrylate polymers or copolymers, hydrocarbon resins, elastomeric polymers, and the like, can be used. The limits for the concentration are governed by desirable coating viscosities, dry weight of the coating, and the like. Concentrations of complexes varying between 5 and 50 percent have been found to be convenient. 
     Similarly, the leuco dye color-forming material is also dispersed by ball-milling or by other convenient means in a solvent-binder system which will not dissolve and dissociate the phenolic molecular complex. The reactive ingredients are ground separately in this case to permit more convenient variation of the ratios of the co-reacting leuco dyes and phenolic complexes. However, this is not a requirement as the leuco dyes and phenolic complexes have been ground together without encountering any signs of mix instability or loss of the marking characteristics of the dried coating. This is not true when the leuco dye, for example Crystal Violet Lactone, is ground with the free phenolic material. The ground mixture becomes highly colored and is useless as a coating material. 
     Coating Applications 
     The mixtures of grinds of the leuco dyes and molecular complexes of phenolic materials were applied by Meyer rod to a 25lb/3000 sq ft sulfite base paper and allowed to air-dry. Dry coating weights of the thermo-sensitive coatings were varied from 1.5 lb/3000sq ft. to over 10 lb/3000 sq ft and useful records were made with each coating. 
     Recording or Imaging the Sensitized Sheets 
     The utility of the described thermosensitive coatings was demonstrated by reproduction of legible copies using a 3M thermal copier sold under the trade name Thermofax Secretary. A Texas Instruments thermal matrix printer, the Silent 700, was used to demonstrate printing with a computer-driven, high speed thermal printer. The thermosensitive coated sheets where run through a Sanborn 500 Viso Cardiette recorder, commonly used in recording electrocardiograms to give useful records demonstrating the chart-recording capabilities. The following examples illustrate the working of this invention. 
    
    
     EXAMPLE 1 
     A leuco dye combined with representative complexes of phenolic materials 
     Crystal Violet Lactone or 3,3-bis-(p-dimethyl amino phenyl)-6-dimethylamino phthalide sold by Hilton-Davis as Brilliant Violet Leuco 70-3044, a well known lactone which is widely used in thermal recording papers and pressure marking papers, was combined in different ratios with molecular complexes formed from a variety of phenolic materials and different amines as the complexing agents. The components were prepared as a 15 percent concentration of the leuco dye or the phenolic molecular complex in a 5 percent solution of polyvinyl alcohol in water. These were ground by ball-milling overnight and combined in various ratios to form the coating mixes. The coatings were applied by Meyer rod to a 25 lb/3000 sq. ft sulfite paper and air-dried to give a variety of coating weights. All were imaged satisfactorily on a 3M Thermofax Secretary thermal copier, a Texas Instruments Silent 700 thermal printer, and a Sandborn Viso Cardiette electrocardiogram chart recorder. In all cases, a bright blue mark was obtained on a white background. 
     
                                           TABLE V__________________________________________________________________________                        Ratio Weight-Complexes                    Complex/                              CoatPhenolic          Amine      Leuco Dye                              lb./3000 sq. ft.__________________________________________________________________________(a)   2,2-thiobis(4,6-dichlorophenol)             Cyclohexylamine                        4/1   1.9   &#34;              &#34;          2/1   2.8   &#34;              &#34;          1/1   2.2   &#34;              &#34;          1/2   2.8(b)   2,2-thiobis(4,6-dichlorophenol)             diisopropanolamine                        4/1   3.7   &#34;              &#34;          2/1   2.3   &#34;              &#34;          1/1   2.4   &#34;              &#34;          1/2   3.1(c)   2,2-thiobis(4,6-dichlorophenol)             N-methylethanolamine                        4/1   1.6   &#34;              &#34;          2/1   2.1   &#34;              &#34;          1/1   1.5   &#34;              &#34;          1/2   2.2(d)   2,2-thiobis (4,6-dichlorophenol)             diethanolamine                        2/1   4.6(e)   2,2-thiobis(4,6-dichlorophenol)             ethanolamine                        2/1   3.2(f)   2,2&#39;-methylenebis (3,4,6-trich-   lorophenol)    triisopropanolamine                        4/1   7.5   &#34;              &#34;          2/1   10.2(g)   &#34;              N-methylethano-             lamine     4/1   8.0   &#34;              &#34;          2/1   6.5(h)   &#34;              dimethylethanolamine                        2/1   3.0(i)   &#34;              cyclohexylamine                        6/1   4.0   &#34;              &#34;          4/1   4.0   &#34;              &#34;          2/1   3.8   &#34;              &#34;          1/2   3.2(j)   &#34;              N-ethyldiethanolamine                        4/1   4.0(k)   1,1-bi-2-naphthol             Cyclohexylamine                        2/1   3.7   &#34;              &#34;          1/1   4.2   &#34;              &#34;          1/2   6.5(l)   2,2&#39;-methylene bis(3,4,6-             N-ethylethanolamine                        2/1   4.0   trichlorophenol)   &#34;              &#34;          1/1   3.0   &#34;              &#34;          1/2   2.5(m)   2,5-dichlorohydroquinone             Cyclohexylamine                        4/1   4.5   &#34;              &#34;          2/1   3.6   &#34;              &#34;          1/2   4.0(n)   2-naphthol     Cyclohexylamine                        2/1   2.5(o)   hydroquinone   Cyclohexylamine                        2/1   5.0(p)   resorcinol     Cyclohexylamine                        2/1   3.0(q)   1,1-butylidene(biphenol)             Cyclohexylamine                        2/1   3.5(r)   Bisphenol A    Cyclohexylamine                        4/1   3.5   &#34;              &#34;          2/1   2.6   &#34;              &#34;          1/1   2.8   &#34;              &#34;          1/2   2.2(s)   p-phenylphenol Cyclohexylamine                        4/1   3.0   &#34;              &#34;          2/1   3.1   &#34;              &#34;          1/1   2.9   &#34;              &#34;          1/2   2.5(t)   2,2&#39;-dihydroxy-5,5&#39;-dichloro-   phenylmethane  Cyclohexylamine                        4/1   2.8   &#34;              &#34;          2/1   3.4   &#34;              &#34;          1/1   3.3   &#34;              &#34;          1/2   2.7__________________________________________________________________________ 
    
     EXAMPLE 2 
     The molecular complex of 2,2&#39;-methylene bis (3,4,6-trichlorophenol) with cyclohexylamine and representative leuco dyes was dispersed in a manner similar to that described in Example 1, coated on 25 lb/3000 sq. ft sulfite paper and the dry coated sheets were imaged on the Thermofax Secretary, the Texas Instruments Silent 700 and the Sandborn 500 Viso Cardiette. 
     
                                           TABLE VI__________________________________________________________________________                      Ratio Wt. Coat                      Complex/                            lb/3000                      Dye   sq. ft                                 Color__________________________________________________________________________(a)  3,3-bis(1-ethyl-2-methylindol-3-yl) phthalide                      2/1   3.0  red(b)  3-diethylamino-7-(N-methyl-p-toluidino)fluoran                      2/1   2.2  green(c)  3-dibutylamino-6-methyl-7-chlorofluoran                      2/1   2.8  red(d)  3,3-bis (dimethylaminophenyl)phthalide                      2/1   3.1  green(e)  2,2&#39;-spiro bi(benzo (f) chromene)                      2/1   3.5  blue-                                 violet(f)  3-methyl-2,2&#39;-spiro bi(benzo (f) chromene)                      2/1   1.9  blue(g)  6&#39;-chloro-8&#39;-methoxybenzoindolino spiropyran                      2/1   2.4  blue(h)  8&#39;-methoxybenzoindolinospiropyran                      2/1   3.0  brownish                                 black(i)  spiropyran from 2-hydroxy-1-napthaldehyde and the  salt of methyl-p-toluenesulfonate with 2-                                 blue-  methlbenzothiazole       2/1   3.6  black(j)  2&#39;-anilino-6&#39;-diethylamino-3&#39;-methylfluoran                      2/1   2.4  green(k)  3-(ethyl-p-tolylamino)-7-(methylphenylamino) fluoran                      2/1   2.9  green__________________________________________________________________________ 
    
     EXAMPLE 3 
     Comparison of stabilities, staining, flooding, railroading. 
     (a) A mixture of 5 parts of Crystal Violet Lactone and 10 parts of the complex obtained by reacting cyclohexylamine with 2,2&#39;-methylenebis(3,4,6-trichlorophenol) is 85 parts of a 5-percent solution of polyvinylalcohol in water was ball-milled for 24 hours. The web coating mixture, which was colorless, was coated onto a 25 lb/3000 sq. ft sulfite paper with a No. 16 Meyer rod and air-dried to give a white coating weighing 3.1 lb/3000 sq. ft. This coated paper was run through a Sanborn 500 Viso Cardiette recorder to give a bright blue trace on a white background. Good trace resolution was obtained without excessive flooding or railroading (developing two bars or streaks on the path made by a hot stylus). 
     (b) (a) was repeated except that the phenol complex was replaced with pure 2,2&#39;-methylenebis (3,4,6-trichchlorophenol). Color developed very early during ball-milling and the mix was a deep blue-grey after 8 hours grinding. This grind was useless in the preparation of a thermo-sensitive coated paper. 
     (c) The crystal violet lactone and the 2,2&#39;-methylene bis(3,4,6-trichlorophenol) were ball-milled as separate dispersions and then mixed and coated on the sulfite paper. This coating when run through the Sanborn recorder showed excessive flooding and railroading. In addition, the coated sheets on standing for a period of time developed a blue stain or background which also indicates instability. 
     (d) Similar results were obtained using the complexed phenolics in Example 2 as a comparison against the phenolic materials which had not been complexed. In all cases, the coatings containing the pure phenolics had a tendency to mark with paper clips or other sharply applied pressure. This accidental marking or marring was eliminated or greatly reduced by replacing the pure phenolic with a complexed phenolic material. 
     Activators may be used to lower the activation temperatures of the systems described above. The image mark is also intensified. Some preferred activators are ureas such as phenylurea, phenylthiourea, and allylurea; carbanilide; thiocarbanilide; zinc acetoacetonate; fatty acid salts of zinc such as zinc stearate and zinc palmitate; and salicylanilide.