Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/124—Duplicating or marking methods; Sheet materials for use therein using pressure to make a masked colour visible, e.g. to make a coloured support visible, to create an opaque or transparent pattern, or to form colour by uniting colour-forming components
  • B41M5/132—Chemical colour-forming components; Additives or binders therefor
  • B41M5/155—Colour-developing components, e.g. acidic compounds; Additives or binders therefor; Layers containing such colour-developing components, additives or binders

Definitions

• the present invention relates to novel pressure- sensitive chromogenic copy systems and receptor sheets and transfer sheets therefor, as well as novel co - positions for use as color developers.
• Still another method for manufacturing salicylates of the present invention is the combination of the two aforementioned manufacturing methods, i.e., the use of solvents in combination with the use of pressurized environments of varying temperatures.
• the salicylates must be processed extensively; i.e., they must go through steps such as layer separation (if a solvent is used), purification (often repeated purifi- cation steps involving counter-current extractions), precipitation of the alkali salt of the salicylate to obtain the free acid by acidifying the aqueous' layer containing the salicylate salt, filtration, and drying.
• the carbonless system manu ⁇ facturer must process the material further to incor ⁇ porate it into a coating and apply it to the color- developing substrate.
• Such further processing by the carbonless manufacturer may involve steps such as grinding, dissolution, mixing with pigments and bin- ders, and, optionally, the formation of a polyvalent metal salt of the salicylate.
• (crude) salicylic-containing compositions can be uti ⁇ lized without any purification as color-developing com ⁇ ponents in carbonless copy papers.
• the present invention comprises forming a salicylic derivative capable of reacting with a chromo ⁇ gen used in carbonless copy papers and, after formation of the crude reaction medium containing such salicylic component, reacting or otherwise combining the crude suspension with a hydrogen-donating compound or a metallic compound, preferably a lithium or a multivalent metallic compound of a metal selected from Groups IIIA through IVB of the Periodic Table, or mixtures thereof to form a metal compound of the salicylate.
• the invention also comprises carbonless copy systems utilizing such products produced in accordance with the teachings of this invention; e.g., the products produced from the salicylic components, as well as transfer sheets and receptor sheets useful in carbonless papers, as well as the resultant color- developer compositions. '
• metal compound of the salicylate means salts, complexes, adducts, esters, mixtures, and all other products resulting from combining the salicylates with the noted metal compounds.
• the term "crude" means that the reaction mixture resulting from the carboxylation step is not treated to the extent necessary to obtain a salicylic component in completely pure form. Partial purification such as washing and/or distillation and/or extraction may be employed to reduce some of the impurities present. For instance, the content of unreacted phenol may be lowered to no less than about 10%, more usually no less than 15 to 20% by weight of the reaction mixture. However, it has also been found that the reaction mixture from the carboxylation reaction containing 30% or more unreacted phenol can be used without any purification. The particular salicylate used is of little rele- vance.
• salicylic acid or oligomeric or polymeric salicylate or thio- salicylate, or any other salicylate which has been or can be used as a color developer in carbonless copy systems.
• salicylic acid and alkylated, cycloalkylated, or arylated salicylates are used.
• Salicylates with C_ to C20 alkyl groups are used; C2 to C12 alkylated salicylates being especially preferred with octyl and nonyl salicylates being exemplary.
• arylated salicylates any phenyl or cyclohexyl salicylic acid can be used.
• the entire reac- tion mixture after the reaction is completed is treated in accordance with the present invention to produce the desired salicylate moiety.
• the thus treated crude mixture contains the desired salicylate moiety as well as up to about 80% by weight of unreacted phenol, carbonates (primarily bicarbonates) and other impurities.
• the pH of the crude aqueous medium is raised to between about pH 7.5 to 12.5 with an alkali such as aqueous ammonia, LiOH, NaOH, KOH, or combinations of aqueous amonia with LiOH or with other water soluble hydroxides; aqueous ammonia or combinations of aqueous ammonia with other alkalis has been found to be the preferred way of adjusting the pH of the coating dispersions containing the crude salicylates of this invention.
• an alkali such as aqueous ammonia, LiOH, NaOH, KOH, or combinations of aqueous amonia with LiOH or with other water soluble hydroxides
• a polyvalent metallic compound selected from Groups IIIA through IVB of the Periodic Table may be added to form the desired metal compound of the salicylate.
• the use of lithium alone in an amount stoichiometric to the particular salicylic acid in the crude mixture or in an amount less than stoichiometric and using aqueous ammonia to reach stoichiometry or beyond can obviate the use of polyvalent metallic com- pounds.
• a hydrogen-donating compound such as an organic or inorganic acid; e.g., hydrochloric, acetic, sulfuric, citric, maleic, glyoxylic, glycolic, and the like and mixtures thereof can also obviate the use of polyvalent metal compounds.
• Another unexpected finding of this invention is that controlling the pH of the coating dispersions containing salicylates or salicylate derivatives, made in accordance with the processes of this invention, by the use of aqueous ammonia and permanent alkalis, along with the use of mineral inorganic acids to effect a pH of the dried CF coated surface of between 5.0 and 8.0, and preferably between 5.5 and 7.5, can offer the best image properties of the salicylates as color develo ⁇ pers.
• the preferred mode of this invention is the use of polyvalent metal compounds along with the careful pH adjustments of the coating dispersions and coated surfaces.
• Preferred polyvalent metals added are zinc, nickel, cadmium, titanium, aluminum, tin, magne ⁇ sium, and manganese and the like, and mixtures thereof with zinc being especially preferred. It is possible to use a mixture of polyvalent metals and the monova- lent lithium and/or hydrogen compounds. Dependent upon the particular salicylate, the metal compound used, and the quantity thereof which is added, a precipitate may form, but such precipitate as well as the remaining portions of the aqueous solution containing the other materials such as noted unreacted phenol, bicarbonates. and the like or the entire solution, if no precipitate is formed, can be easily and directly formulated as hereinafter set forth into a color-developing coating.
• the color-developing coating is prepared by admixing the impure salicylate mixture with conventional pigments such as clays, carbonates and the like and/or conventional adhesives or binders such as natural or modified starches, latexes, partially or fully hydrolyzed polyvinyl alcohols, proteins, gums. and the like conventionally used in forming carbonless copy paper; all being added in their usual amounts for their usual effect.
• conventional additives such as pigment dispersants and coating lubricants can also be used.
• the main function of the conventionally used pigments in preparing coated front (CF) formulations is to "extend” or "spread out” the principal color- developing material for a more efficient use.
• the nature of the extending pigment is inconsequential; calcium carbonate, various types of clays, or combinations of calcium carbonate and clays have been used as extending pigments in formulating the impure salicylates of this invention, without any apparent influence in the functional properties of the CFs containing the salicylates noted herein as color developers. This is demonstrated in Table II, where the same salicylate moiety is formulated with different extending pigments without any evident loss in func- tional properties.
• a generally accepted indicator of the efficiency of a color developing material in carbonless CF papers is the amount of the color developer used relative to the amount of the extending pigment, usually expressed as a percent by weight of the color developer on the weight of the pigment. It has been surprisingly found during the development of this invention that only relatively small amounts of the salicylates are required to give superior results, i.e., speed of image formation and image intensity and stability, when the salicylates are manufactured and processed in accordance with the modes described herein. For example, 4% to 10% by weight of the salicylates of the present invention on the weight of the pigment is sufficient to produce superior image intensities and stabilities compared to color- developing materials heretofore described in the prior art [U.S. Patent Nos. 3,934,070, 4,051,303, 4,147,830, 4,159,208 and others] and reported to be used at between 30% and 1000% of the weight of the color developer on the weight of the pigment.
• the final mixture is applied in the conventional manner as by conventional paper coaters, such as an air knife, gate roll, blade, reverse roll, and the like in the usual thickness to substrates conventionally used for forming carbonless copy paper (usually paper) to form the color-developing part (receptor or transfer sheet) of a carbonless pressure-sensitive chromogenic copy system.
• conventional paper coaters such as an air knife, gate roll, blade, reverse roll, and the like in the usual thickness to substrates conventionally used for forming carbonless copy paper (usually paper) to form the color-developing part (receptor or transfer sheet) of a carbonless pressure-sensitive chromogenic copy system.
• the coating noted can be mixed with a solution of leuco dyes containing microcapsules and applied to a single surface to form a "self-contained" type of carbonless system.
• the salicylate formed is usually extracted from the solvent by the addition of sufficient amounts of water and unreacted or uncarboxylated phenols usually stay mainly in the solvent layer and do not interfere with the processing of the water layer.
• the water layer in addition to the desired salicylate usually contains up to about 5% to 6% by weight of solvent, up to 50% by weight or more of unreacted phenol, up to about 10% by weight of catalyst, and up to about 15% by weight of carbonates (primarily bicarbonates). Following the separation the water layer is treated in the manner described above to form the metal compound of a salicy ⁇ late and color developer.
• an oligomeric or polymeric condensation product of the salicylate is the final desired color developer subsequent to the carboxylation reaction and layer separation, if one is required, as is conventional, the pH of the water layer is again adjusted to the alkaline side for the formation of oligomers or pH on the acid side for the formation of higher molecular weight poly ⁇ mers and the condensation agent, such as an aldehyde or the like, is added and the condensation reaction is allowed to proceed under time and temperature con- ditions suitable for the formation of the desired pro ⁇ duct.
• the condensation agent such as an aldehyde or the like
• the crude sali ⁇ cylate solution should contain at least about 5% to 25% by weight of the particular salicylate. This permits preparation of the color developer which preferably should contain at least about 1% by weight of salicy- late, dependent upon the particular salicylate used.
• the instrument used to make the intensity measurements was a Brightimeter Micro S4-M Brightness, Opacity, and Color Tester.
• the L value on the Hunter L,a,b scale which the Brightimeter calculates was taken as a measure of the color intensity of the images. Since lower L values on the 0-100 scale mean higher image intensities, the Intensity values (I) presented in Tables I and II were calculated as 100-L.
• To measure light resistance the colored images were exposed for twenty hours to a General Electric cool white fluorescent bulb at a distance of six inches and the intensity of the image was compared before and after exposure.
• the reaction mixture is cooled to 120°C under a nitro ⁇ gen atmosphere, and 7.3 grams (0.1 mole) -of dimethyl formamide are added; while maintaining the agitation and the temperature to between 125-130°C, 4.5 grams of carbon dioxide are added to the mixture through a sub ⁇ surface gas inlet tube for approximately 30 to 60 minu ⁇ tes.
• the solution temperature of 125-130°C is maintained for about one additional hour after the addition of the carbon dioxide has been completed.
• the reaction mixture is then cooled to about 90°C, 68-70 grams of water are added with thorough mixing for about 15 to 20 minutes, the mixing is stopped and the phase separation is allowed to occur.
• Fourteen grams of a 50% by weight aqueous solution of zinc chloride are added slowly and with agitation forming a precipitate; this precipitate remains stable over an indefinite period of time and over a wide range of temperatures.
• the coating can be prepared by applying the crude solution containing the flocculant precipitate directly to a paper substrate at very low coating weights of about 1.5 to 2.2 g/m2, after mixing with small amounts (10% to 15% by weight on a dry basis) of one or more binders such ethylated or oxidized starches, and/or small amounts (10% to 15% by weight) of a styrene- butadiene latex (Dow's latex-638), producing a receptor or color developer coated front (CF) part of a car ⁇ bonless paper product.
• binders such ethylated or oxidized starches
• the solution containing the floc ⁇ culant precipitate is formulated into a coating by the addition of 200 grams of calcium carbonate, 130 grams of a 20% aqueous solution of ethylated starch, and 30 grams of Dow's latex-638 (48% by weight aqueous solu ⁇ tion) and applied to a paper substrate at low coating weights (2 to 3 g/m 2 ). Images of the same high inten- sity, speed and brightness as those obtained from the nonpigmented formulation are obtained.
• COMPARATIVE EXAMPLE la Twenty-five grams of pure, conventionally produced octyl salicylic acid are dissolved in 100 grams of water with the aid of 12.5 grams of a 45% aqueous solu ⁇ tion of potassium hydroxide. The pH of the solution is raised to between 12 and 13 using a concentrated solu ⁇ tion of aqueous ammonia, mixed with 14 grams of a 50% aqueous solution of zinc chloride and formulated into coatings (with and without pigments) as described in Example 1 above.
• the properties of the images formed on the CF paper of this example are identical to the properties of the images produced on the CF of Example
• Example 1 is repeated, but the aqueous layer con ⁇ taining the octyl salicylic acid is drained off into a suitable vessel equipped with an agitator, 4 grams of an aqueous (37% by weight) formaldehyde solution are added and the reaction mixture is heated to between 85 and 90°C and maintained at this temperature for 2 to 4 hours while maintaining the pH at between 8.5 and 9. At the end of this reaction, almost all of the for- maldehyde has been consumed, and oligomers of the octyl salicylate have been formed.
• the crude oligomeric octyl salicylate reaction mass is treated in a similar manner to that described in Example 1; i.e., the pH is raised to between 12 and 13 with concentrated aqueous ammonia, and the zinc chloride solution is added to form the flocculant precipitate. Subsequently, the solution containing the flocculant precipitate is for ⁇ mulated into the coatings described in Example 1 and applied to a paper substrate in equivalent coating weights.
• the images produced on such CF surfaces possess properties similar to the images produced in Example 1, but in addition they exhibit improved sta ⁇ bility to severe light exposures.
• Example 2 is repeated, but the water layer contains the p-tert.butyl salicylate produced in Example 3.
• the CF papers produced using the methods described in Example 1 exhibit equivalent properties.
• Example 1 is repeated, but the p-octyl phenol is replaced with equimolar quantities of 2,4, ditertiary butyl phenol.
• the resultant material, 3,5, ditertiary butyl salicylate, and/or its metal salts, when used as the color developer in a CF coating exhibit properties equivalent to those obtained with the octyl salicylate- containing CF.
• Example 1 is repeated up to the point of draining off the lower layer (water phase) containing the potassium salt of the salicylic acid product, except that the p-octyl phenol is replaced with equimolar quantities of phenol.
• the resultant salicylic acid salt contained in the water layer is reacted with 16 grams of aqueous formaldehyde solution (37% by weight) in the presence of 25 grams of 12N sulfuric acid solution at a temperature of 95 to 97°C for one hour to produce a high molecular weight polymer of salicylic acid.
• the alkaline salt of this material was treated in a manner similar to that described in Example 1 to form the flocculant precipitate, and formulated into coatings according to the methods described in Example 1.
• the CF papers produced containing the material of this example exhibited properties similar to those of the CF produced in Example 1, but the images required substantially higher amount of time to develop full intensities.
• Example 7 Example 1 is repeated throughout, but the p-octyl phenol is replaced with equimolar quantities of 2-methyl, 3-isobutylthiophenol.
• the resultant product, 2-hydroxy-4-methyl-5-isobutylthiobenzoic acid and/or its metal salts, when used as the color developer in a CF coating exhibit properties equivalent to those obtained with the CF containing the octyl salicylate product.
• Example 1 is repeated in its entirety, but the p- octyl phenol is replaced with equimolar quantities of p-t-butylthiophenol.
• the resultant product, 2-hy- droxy-5-t-butylthiobenzoic acid and/or its metal salts when used as the color developer in a CF coating, exhibit properties equivalent to those obtained with the CF containing the octyl salicylate product.
• EXAMPLE 9 Twenty grams of an impure mixture of m-nonyl sali ⁇ cylic acid and nonyl phenol containing about 11 grams (55% of total mixture weight) of nonyl phenol and about 1-1.5 grams of potassium carbonate and xylene, are dissolved in 100 grams of water containing 1.5 dry grams of sodium hydroxide. While maintaining the solution under agitation, 5.8 grams of 50% by weight of an aqueous solution of zinc chloride are added and allowed to react, forming the zinc salt of the nonyl salicylic acid.
• CF surface When the CF surface is mated with a coated back (CB) of a carbonless form containing leuco dyes (usually in an encapsulated form) and localized pressure is applied, bright and intense images are formed instantaneously on the CF surface.
• CB coated back
• Example 10 The process of Example 9 is repeated except that 1 gram of lithium hydroxide is substituted for the 1.5 grams of sodium hydroxide used therein and no zinc chloride is added. Equivalent results are obtained.
• EXAMPLE 11 Twenty grams of an impure mixture of m-nonyl salicylic acid and nonyl phenol containing about 50% by weight nonyl salicylic acid, about 43-45% by weight nonyl phenol, and about 5-7% by weight of potassium carbonate and xylene, are dissolved in 90 grams of water containing 0.5 dry gram of sodium hydroxide, and 10 grams of concentrated aqueous ammonium hydroxide. While maintaining the solution under agitation, 15 grams of zinc oxide are thoroughly dispersed therein.
• a 72% by weight dispersion of calcium carbonate and kaolin clays in water are added along with 36 grams of Dow's latex-620 (50% solids by weight) and 92 grams of a 20% by weight aqueous solution of ethylated starch.
• the pH of the dispersion is adjusted to about 11 with a concentrated aqueous ammonium hydroxide solution (28% by weight) , and applied onto a paper substrate at a coating weight of between 5 and 7 g/m 2 producing a receptor or color developer coated front (CF) part of a carbonless product.
• CF receptor or color developer coated front
• Example 14 The process of Example 9 is repeated except that the zinc chloride is replaced with 15 grams of an 18% by weight solution of zinc octoate in mineral spirits. Equivalent results are obtained.
• Example 15 The process of Example 11 is repeated except that the 213 grams of the calcium carbonate and kaolin clays dispersion are replaced with 213 grams of a 72% by weight dispersion of kaolin clays in water. Equivalent results are obtained.
• EXAMPLE 16 The process of Example 11 is repeated except that the 213 grams of the calcium carbonate and kaolin clays dispersion are replaced with 213 grams of a 72% by weight dispersion of a 50-50 mixture of calcium carbonate and kaolin clays. Equivalent results are obtained.
• Example 9 The process of Example 9 is repeated except that the zinc chloride is replaced with 8 grams of a 12% by weight hydrochloric acid solution. Equivalent results are obtained. EXAMPLES 18-25
• Examples 9 through 16 are repeated except that the 20 grams of the impure mixture of nonyl salicylic acid are replaced with 13.5 grams of an impure mixture containing about 75% by weight nonyl salicylic acid, about 20 to 22% by weight of nonyl phenol, and about 3 to 5% by weight potassium carbonate and xylene. Equivalent results are obtained in all cases.
• Microcapsules containing leuco color formers are manufactured according to the specifications of U.S. Patent No. 4,586,060, as follows:
• An oil solution comprising 90 grams of monoisopropylbiphenol, 3 grams of Hilton Davis' N-102 black leuco dye, 1 gram of Crystal Violet Lactone, 0.5 gram of benzoyl leuco methylene blue, 0.4 gram of Hilton Davis' Kopichem XIV leuco dye, and 5 grams of a hexamethylene di-isocyanate adduct (Mobay's Desmondur L-2291A) are emulsified with 100 grams of a 13% by weight aqueous solution of gelatin (Hudson Industries G-110). Emulsification is continued until an average particle size of between 5 and 5.5 microns are obtained and the solution is heated to 65°C for about two hours.
• microcapsular dispersion is cooled to room temperature and mixed with 35 grams of load-bearing material such as Henkel's Keestar-328, a granular, uncooked starch, and 100 grams of a 20% by weight aqueous solution of ethylated starch. The solids of the microcapsular dispersion are adjusted with water to between 35 and 40% by weight.
• load-bearing material such as Henkel's Keestar-328, a granular, uncooked starch, and 100 grams of a 20% by weight aqueous solution of ethylated starch.
• Example 11 Two hundred grams of a color developer CF coating prepared according to the procedure of Example 11 are thoroughly mixed with 75 grams of the microcapsular dispersion of this Example, coated onto a paper substrate at a coating weight of about 6.5 gms/m2, and dried. When pressure is applied to the coated surface, the microcapsules are ruptured, releasing the oily material containing the leuco color developers and forming an in-situ black image of high intensity and excellent light stability.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Color Printing (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Lubrication Of Internal Combustion Engines (AREA)
• Photoreceptors In Electrophotography (AREA)
• Medicines Containing Material From Animals Or Micro-Organisms (AREA)
• Heat Sensitive Colour Forming Recording (AREA)

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• 1988
  • 1988-07-19 DE DE8888906823T patent/DE3871771T2/de not_active Expired - Lifetime
  • 1988-07-19 AU AU22622/88A patent/AU608651B2/en not_active Ceased
  • 1988-07-19 WO PCT/US1988/002366 patent/WO1989000506A1/en not_active Application Discontinuation
  • 1988-07-19 AT AT88906823T patent/ATE76816T1/de not_active IP Right Cessation
  • 1988-07-19 BR BR888807134A patent/BR8807134A/pt not_active Application Discontinuation
  • 1988-07-19 JP JP63506830A patent/JPH02500428A/ja active Pending
  • 1988-07-19 EP EP88906823A patent/EP0330685B1/en not_active Expired
  • 1988-07-22 CA CA000572860A patent/CA1305321C/en not_active Expired - Lifetime
  • 1988-10-27 FI FI884964A patent/FI884964A/fi not_active IP Right Cessation
• 1989
  • 1989-03-22 DK DK147489A patent/DK147489D0/da not_active Application Discontinuation

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