US2743191A - Method for manufacturing transfer sheets for spirit duplication - Google Patents

Description

METHOD FOR MANUFACTURING TRANSFER SHEETS FOR SPIRIT DUPLICATION Patented Apr. 24, 1956 base presents the additional problem of removal. The system of Neidich corresponds with that of Holik previously described who reacts the water soluble dye with ammonia to form the base and thereby presents a less 5 soluble surface. In both of these systems the transfer Robert I. Klimkowshi, Chica o, nd Robert '1, Fl sheet is formed with a dye but .in Neidich the dye is less Park Ridge, Ill., assignors to A. B. High Company, soluble in water until reacted with acid and then the Niles, IIL, a corporation .of Illinois dye becomes a conventional water solurble dye capable of transfer in aqueous or :in alcoholic medium. Before reacstssta6.thatassistsemits:s3 we h dye of 1952, Serial No.,304,207 alco olic meolum to form copies as in normal spirit dupl cating systems. 6 Claims. (Cl. 117-36) Briefly described, in the process forming the subject 7 matter of the prcsent application, a dyestuif is not formed This invention relates to anew spirit duplicating sys- 5 in the transfer Shefit l hema r t n r h tem for the production of multiple copies and it relates PY Sheets but is formed ta a ly i i i y more particularly to a method for the-manufacture of byreaction in the py sheets so h the dy P oduce transfer sheets to be used in the production of duplicatat a stage incapable 0 n amina n e QP fl 1i ing masters from which multiple copies are secured. "4 w pI:0duce d i the DY d h dyestuff is n More specifically, this invention comprises a division of substantially 111$h1b1e Ph 168.8 l ly t0 trallsftlr Of our copfinding application s N 237 616 filed 011 May deteriorate even under humid conditions, In practice, 13,1951 the coating on the transfer sheetis formulated with less In the aforementioned copending application, descrip- Q1 all of 1 cfimponems from whiflh an 3 d ti tion is made of a new and improved spirit duplicating 1S -I Such as fi Coupler a dlaZQ, P h bu and hectographic process in which reaction to form a W both a e p fi l l file i ff Coating, th d t fi' in the production f copies takes place in the ditions are such as to forestall reaction therebetween to copy hegts upon assage the maform thCUdYCS lIIfl uljltll alkaline Condltlol'ls are chine so that the pwcgssis entirely f f the staining In the fluid with which the copy sheets are wet P11011110 or soiling characteristic of present hectographic or spirit Contact W151 the lmaged mas T1111? the coupllng duplicating systems. In present systems, the t f Sheet 39 agent and diazo transferred from the imaged master i Iibbcn is compounded with a watgr and almhol 1 to the copy sheets are able to react in the copy sheet to uble basic dyestuif of the type crystal violet, Victoriagreen form the dyestufi- P transfer Coatmg Contams and the like. These dyestuffs are colloidal i oh g nly the coupler, the fluid is formulated not only to conso that many difiiculties are encountered in compounding ta111 the alkall but 9 the w tfansfef the coating composition and app-ligation thereof to f coating contains the (112120, then the fluid containing the the transfer Sheet Without Contamination of 1 Sup alkali s formulated also to contain the coupler for read rounding atmcsphere and spread of dyg onto the hands tion with the diazo to form the dyestufi' 1n the copy sheets. and clothing of the Various peratprs The t f h n Instead of supplying the missing components in the fluid in m mastgl- Set and its use hnhe duplicating machine to for reaction with the component or components in the produce copies raises still f th problems f Contaminw 40 transfer coatingor imaged master, the additional corntion with respect, to the Qpcrators hands and clothi ponent for reaction to form the dyestulf may be supplied with dyestuff which seemingly spreads and resists re as a Substance embodled 111 the PY Sheets, as y i movaL pregnation or as an ingredient in the .slurry from which Many attempts have been e to .obviatg the Color the copy sheets are formed, or in a fluid applied to the transfer value 0f the dyestufl in the .transfer shfiets and surface of the copy sheets after contact with the imaged in the formed master. Various coatings have been apf In any W511i, h transfer Coating and the plied "to the surface of the transfer sheet in order to prolmaged maste? are f lfl f f C0101 transfer and tect the operator but dyestulf is-invariably removed upon dyestllfi 18 formed p incipally in the copy sheets. contact with the master sheet to make corrections and Even the, the dyestuff 15 not formed lmmedlately but the image formed on the masterpresents an unprotected reaction appears to take P a Slowly whereby the P! surface identical to that of the conven iona .mastc z appears P stanfhilg the COPY Shifts Other re recen mod fication o vi te his Pro l m have 193* through of Staining or soiling in this Practice 9f P e'sve'n't'v beetle, :The invention described and claimed herein resides graph and spirit duplicating systems indudeauQmpts m chiefly 111 the manufacture of transfer sheets used to proinsolubilize the Surface portion of the u-ansfq mating duce the imaged master and it is an ob ect of this nby reaction f the basicdyesmfi Withammwjg, in th? vention to provide a new and improved method tor i-Iolik Patent No. 2,564,909, but the image master again manufacture of transfer Sheets 9 the type desmbedi presents an unprotected surface and dye transfer from Order to Produce a good lmage on the the imaged master occurs as readily as in present sysuse In the manufaciure of a large numb of 1 It tems and dye transfers Q1110 the hands and qlvothlingvof 60 has been found desirable to prepare a transfer coating the ope at r y y ab a With. the transfer sheet; hlch is relatively poorly bonded to the base sheet so as or cohtact i the cut edges duringsmcking th? 1 to enable substantially complete release of as much ma- The problem of contamination -facgd terial 3S POSSlblE to the master surface and Sufb N idi h i P t t NQ 2,146,976, N idi h attempts ficient sharpness to produce copy of good quality. Putto Overcome the ability of h dye to 13 11 ther, it has been found that to produce a master capable hands of the operator by converting the dyestuff to a a of use in the manufacture of hundreds of cop 8 phase which is less soluble in Water so that transfer will quality, it is desirable also to load as much of the active not as easily occur onto the moist .hands or clothing ingredients for producing the image as is possible to inwhich come in'contact therewith. However, thedye base corporate in the transfer coating consistent with the is capable of transfer by rubbing Qr'byengagementi-of the ability of the carrier, such as the wax base, to maintain hand with cut edges upon stacking and thena morezdifiicult problem is presented because the less soluble dye continuity in the coating for reproduction purposes. it has been found that to produce acceptable copy in the amounts of one hundred or more from the imaged master, concentrations of the coupler and diazo alone or in combination in the transfer coating should correspond to not less than about 20 percent by weight of the coating up to about 50 percent by weight of the coating. When both elements are combined in the transfer coating, the amount of the active ingredients may be increased to about 75 percent by weight of the coating composition.

It has been found further that these characteristics are best embodied in a transfer coating applied to the base sheet in the form of a hot melt wherein an excess of the coating composition in molten form is applied to the surface of the base paper and then the excess is removed with a doctor knife or the like to smooth the coating and produce a continuous layer of uniform thickness.

When the transfer coating is formulated to contain only the coupler for reaction with the diazo in the fluid or in the copy sheet or after applied to the copy sheet, limitation as to temperature and conditions for coating are not so important. When the diazo is incorporated alone or in combination with the coupler in the transfer coating, then it is important to maintain the temperature of the melt below 90-95 C. unless certain stabilizers are present and to make use of diazos which are not destroyed by such temperatures. To the present diazo materials capable of use in compositions for application as a hot melt are found to have the general formula =N-Ol wherein the R2 group comprises 02H; /CH3 (32H; C2135 N ---N --N N CzH5 CH: CzHAOH CH3 and l -N-H It has been found that the stability of the diazo dye forming components is vastly improved when embodied in the treating composition as their corresponding zinc chloride or sulfonic acid salts such as For purposes of economy in reproduction and for purposes of simplicity in the process, it is desirable to incorporate the more expensive ingredients, such as the coup ler and the diazo, in the transfer sheet for use in the preparation of the imaged master from which multiple copies are produced. While some of the diazo compounds remain unreactive in the presence of couplers until the alkali is applied with the fluid, it is better to maintain acidic conditions in the transfer coating as by the addition of acidic medium to maintain the pH of the composition below that at which coupling can take place to form the azo dyestuff. With the basic dyes of the azo type, coupling will generally not take place below a pH of about 3.5. In the coating composition it is preferred, for purposes of stabilization, to formulate the coating for a pH between 1.5 and 3.5.

Compounds capable of use as couplers with the diazo in accordance with the practice of this invention are somewhat limited in character. Generally such couplers should be capable of removal of a hydrogen atom for combination with the chloride ion of the diazo compound to form the dyestufi. Such reactions are secured by the use of aromatics having amine groups such as aniline and substituted aniline like dimethyl anilin, or phenolic compounds such as phenol, resorcinol, phloroglucinol, 2,3-dihydroxy naphthalene, 6,sulfonic acid and water soluble salts thereof and the like, or thio compounds such as thio-barbituric acid or cyano compounds such as cyanoacetamide.

The following will illustrate the practice of this invention in the manufacture of a transfer sheet embodying the coupler and diazo which are reacted to form the azo dyestutf in the copy sheets:

Example 1 5 .0 percent by weight carnauba wax 20.0 percent by weight of microcrystalline wax 15.0 percent by weight parafiin wax 20.0 percent by weight of petrolatum 20.0 percent by weight p-diazo diethyl aniline zinc chloride 20.0 percent by weight 1,amino-8,naphtol-4,sulfonic acid Example 2 15 .0 percent by weight microcrystalline wax 15.0 percent by weight parafiin wax 30.0 percent by weight petrolatum 30.0 percent by weight p-diazo diethyl aniline zinc chloride 10.0 percent by weight 2,4-diamino toluene dihydrochloride The following examples will illustrate the practice of this invention in the manufacture of a transfer sheet embodying the coupler only or the diazo only for reaction with the other in the presence of the base and supplied with the fluid to form the dyestutf in the copy sheets:

Example 3 8.0 percent by weight carnauba wax 11.0 percent by weight oxidized microcrystalline wax 3.0 percent by weight polybutene 6.0 percent by weight petrolatum 17.0 percent by weight mineral oil 55.0 percent by weight p-diazo diethyl aniline zinc chloride Example 4 8.5 percent by weight carnauba wax 14.0 percent by Weight oxidized microcrystalline wax 12.0 percent by weight dark petrolatum 15.5 percent by weight mineral oil 50.0 percent by weight p-diazo ethyl hydroxyethyl aniline zinc chloride Example 5 12.5 percent by weight carnauba wax 10.5 percent by weight microcrystalline wax 12.0 percent by weight petrolatum 15.0 percent by weight mineral oil 50.0 percent by weight diazo dimethyl aniline zinc chloride Example 6 19.0'percent by weight carnauba' wax 25.0 percent by'wei'ghtcetyl alcohol 14.0 percent by'weight mineral'oil 42.0 percent by Weight p-diazo diethyl toluidine zinc salt Example 7 8.5 percent-by weight carnauba wax 14.0 percent by weight oxidized m'icrocrystalline wax 12.0 percent by weight petrolatum 15.5 percent by Weight mineral oil 50.0 percent by weight phloroglucinol Example 8 5.0 percent by weight carnauba Wax 20.0 percent by Weight microcrystalline wax 15.0 percent by Weight paraflin Wax 15.0 percent by weight petrolatum 35.0 percent by weight phloroglucinal 10.0 percent by weight triethanol amine In each of the above examples, the coating composition is ground to achieve uniform distribution with the wax base carrier in a roller mill and, at the same time, it is possible .to heat the composition to a temperature of. about 8090 C. for the purposes of reducing the composition to molten condition. Application is made of the hot melt to a base sheet in the form of a Web of paper to achieve a relatively nonadherent coating in Weights of about 1520 pounds per 3,000 square feet of surface area. The hot melt is applied over the surface of the web in excess of the coating weight required and then the excess is removed by a doctor blade or the like. The coating composition becomes soft and flexible upon cooling to room conditions but is substantially incapable of offset unless forces are applied to cause displacement of the coating onto a receptive surface in contact therewith.

The coated web is sheeted and positioned with the coated side adjacent the master sheet in a formed master set. When the opposite side of the master is inscribed or impacted as by die impression or by a typewriter key, the coating in the impression areas transfers from the base sheet to the adjacent surface of the master sheet in reverse image. Instead of impression forces to effect transfer, thermal forces may be employed such as are made available by the process described and claimed in the copend ing application of Allan l. Roshkind, Ser. No. 273,530, filed on February 26, 1952, to produce the imaged master directly from an original. Thereafter, the master may be mounted in the duplicating machine for subsequent engagement with copy sheets, wetted with a suitable fluid to cause transfer of fractional portions of the dye forming components from the imaged master to the copy sheet where such components are caused to react and form the dyestuif.

When the master is prepared of a transfer sheet in which the coating corresponds to the compositions of Examples 1 and 2, the fluid with which the copy sheets are wet may be formulated as follows:

Example 9 0.5 percent by weight phloroglucinol 5 .0 percent by weight b-naphthol 2.0 percent by weight diethanol amine 92.5 percent by Weight methanol Example 10 5 .0 percent by weight phenyl methyl pyrazolone 2.0 percent by weight diethanol amine 93.0 percent by weight methanol 6 Example 11.

2.0 percent by weigh-t potassium hydroxide 98.0 percent by weight methanol When the transfer coating; is prepared-with the compositions of Examples 3-7, the fluid with which the copy sheets are wet may be formulated of the following:

Example 12 5 .0 percent by weight 2,3dihydroxy naphthalene, 6-sulfonic acid 8.0 percent by weight diethanol, amine.

10.0 percent by weight water.

77.0 percent by weight methanol Example 13 3.0 percent by Weight phloroglucinol 2.0 percent by weight resorcinol 11.0 percent by weight sodium hydroxide 94.0 percent by weight ethyl alcohol When the transfer sheet is formulated to contain the coupler, as in Example 8 the fluid used to wet the copy sheets may be formulated of the following:

Example 14 2.0 percent by weight p diazo diethyl aniline Zinc chloride 98.0 percent by weight methanol The specific composition of the base in which the azo dye forming component is embodied in the manufacture of a transfer sheet may be formulated of waxy materials in various combinations including carnauba wax, microcrystalline wax, paraflinwax, and the like, preferably in combination with softening or plasticizing agents such as mineral oils, fatty acids and the like. Modification to improve the strength and the film forming characteristics may be made by the addition of small amounts of polyethylene, polybutene and; other polymeric compounds formed by addition polymerization and other materials capable of miscibility with. the waxy substances to form a stable composition. The composition for preparation of the transfer coating should be capable of providing a continuous layer having. the characteristics of transferability to adjacent surfaces responsive to impression forces or previously described thermal forces and it is preferred to form the composition with materials having slight solubility in spirit solvents so as continuously to cleanse the surface of the imaged master during the production of copy.

While it is preferred to apply the composition of the transfer coating as a hot melt, it may be possible to achieve the desired formation of the transfer layer by application of the materials in corresponding proportions from solvent solutions or aqueous emulsions. However, the cost and dangers involved for the elimination of such solvents and the necessity for the application of multiple coatings to achieve the desired coating weights makes it highly undesirable to employ such systems but, when such solvent or emulsion systems are employed, limitation as to the type of diazo stable at elevated temperatures is notso critical so that use of other diazo systems for the production of various colors in the copy sheets may be employed.

It Will be understood that other dye systems, such as the leuco dyes separable into substantially colorless dye forming components which are water and alcohol soluble and one of which may be embodied as a component in the imaging or carbon coating material to form the imaged master and the other in the fluid or in the copy I Example 15 12.0 percent by weight carnauba wax 10.0 percent by weight microcrystalline wax 12.0 percent by weight petrolaturn 15.0 percent by weight mineral oil 51.0 percent by weight leuco base of malachite green A fluid for use in combination with the above to develop the malachite green dye in the copy sheet may be formulated of the following:

Example 16 4.0 percent by weight potassium dichromate 1.0 percent by weight nitric acid 45.0 percent by weight ethanol 50.0 percent by Weight methanol Example 17 Carbon coating composition:

33.0 percent by weight polyethylene glycol having an average molecular weight of 6000-7500 (Carbowax 6000) 33.0 percent by weight polyethylene glycol having an average molecular weight of 1500 (Carbowax 1500) 34.0 percent by weight phenolphthalein A fluid for use in combination withthe composition of Example 17 and with which the copy sheet may be wetted to form the dye color therein is formulated of the following:

Example 18 1.0 percent by weight sodium hydroxide 99.0 percent by weight ethyl alcohol Example 19 Carbon coating composition:

33.0 percent by weight polyethylene glycol having an average molecular weight of 6000-7500 (Carbowax 6000) 33.0 percent by weight polyethylene glycol having an average molecular Weight of 1500 (Carbowax 1500) 17.0 percent by weight sodium persulphate (NELISZOB) 17.0 percent by Weight p-phenylenediamine A fluid composition for use in wetting a copy sheet to develop a dye therein by reaction with the active ingredient in the imaging composition of Example 19 may contain the following:

Example 20 20.0 percent by weight aniline 80.0 percent by weight glacial acetic acid It will be understood that the transfer sheets formed by the method described and claimed herein constitute a new and improved article of manufacture and that changes may be made in the specific formulations and methods of application within the limitations defined to produce the transfer sheet without departing from the spirit of the invention, especially as defined in the following claims.

We claim:

1. The method of preparing a transfer sheet of the type described comprising the steps of formulating a coating composition having a wax base and from 20 to 75 percent by weight of a water and alcohol soluble diazo dye intermediate stable at temperatures up to and including the temperature of the wax melt, heating the composition to a molten stage, and applying the hot melt onto a base sheet to form a continuous layer which is poorly bonded to the base sheet.

2. The method of preparing a transfer sheet of the type described comprising the steps of formulating a coating composition comprising a wax base and containing a high proportion of a diazo dye intermediate stable at temperatures up to 95 C. and lacking in color transfer value and a coupler capable of'reaction with the diazo at pHs above 3.5 to form a diazo dyestutf, the composition being acidified to maintain the pH below 3.5, heating the composition to a temperature below 95 C. to reduce the composition to a molten state and applying the hot melt onto a base sheet to form a continuous coating which is poorly bonded to the base sheet.

3. The method of preparing a transfer sheet of the type described comprising the steps of formulating a coating composition having a wax base and from 20 to percent by weight of a water and alcohol soluble diazo having the general formula N=NOl wherein the group is selected from the group consisting of C2115 CH2 ciHs Cafis C1115 CH: CaHtOH CH1 and and the stabilized salts thereof heating the composition to a molten state, and applying the hot melt onto a base sheet to form a continuous layer.

4. The method of preparing a transfer sheet of the type described comprising the steps of formulating a coating composition comprising a wax base and containing a high proportion of a diazo having the general formula N=N--Cl wherein the R2 group is selected from the group consisting of /C:4H5 /CH3 /C:H5 Gi s 0211 on, Canton OH: and

-N-H and the stabilized salts thereof, and a coupler capable of reaction with the diazo at pHs above 3.5 to form a diazo dyestufi, the composition being acidified to maintain the pH below 3.5, heating the composition to a temperature below 95 C. to reduce the composition to a molten state and applying the hot melt onto a base sheet to form a continuous coating which is poorly bonded to the base sheet.

5. The method of preparing a transfer sheet of the type described comprising the steps of formulating a coating composition comprising a wax base and containing a high proportion of a diazo dye intermediate stable at temperatures up to 95 C. and lacking in color transfer value and a coupler capable of reaction with the diazo at pHs above 3.5 to form a diazo dyestuff and selected from the group of aromatic compounds consisting of ammatic amines, phenols, aromatic thio compounds and aromatic cyano compounds, the composition being acidified to maintain the pH below 3.5, heating the composition to a temperature below 95 C. to reduce the com position to a molten state and applying the hot melt onto a base sheet to form a continuous coating which is poorly bonded to the base sheet.

6. The method of preparing a transfer sheet of the type described comprising the steps of formulating a coating composition comprising a wax base and containing a high proportion of a diazo having the general formula 10 wherein the I v group is selected from the group consisting of 0 1H: 0 H: C In; CIHI -N -N -N 0,11, om mmon CH| and References Cited in the file of this patent UNITED STATES PATENTS 38,086 Underwood -e Mar. 31, 1863 2,010,884 Olpin Aug;- 13, 1935 2,146,976 Neidich Feb. 14, 1939 2,595,916 Bartels May 6, 1952 2,597,306 Eaton May 20, 1952 FOREIGN PATENTS 524,786

Great Britain '.Aug. 14, 1940

Claims (1)

1. THE METHOD OF PREPARING A TRANSFER SHEET OF THE TYPE DESCRIBED COMPRISING THE STEPS OF FORMULATING A COATING COMPOSITION HAVING A WAX BASE AND FROM 20 TO 72 PERCENT BY WEIGHT OF A WATER AND ALCOHOL SOLUBLE DIAZO DYE INTERMEDIATE STABLE AT TEMPERATURES UP TO AND INCLUDING THE TEMPERATURE OF THE WAX MELT, HEATING THE COMPOSITION TO A MOLTEN STAGE, AND APPLYING THE HOT MELT ONTO A BASE SHEET TO FORM A CONTINUOUS LAYER WHICH IS POORLY BONDED TO THE BASE SHEET.