GB2032932A - Carbonless pressure sensitive copying paper and a desensitizing ink composition therefor - Google Patents

Abstract

A copying paper having a color developing acidic material layer for developing color when contacted with a colorless dye can be sufficiently desensitized on a portion which is not desired to be given a image by printing on the portion a desensitizing ink composition comprising a poly(oxypropylene)glycol or triol, a copolymer thereof with polyoxyethylene, an aliphatic alcohol or a phenol adduct thereof, or a carboxylic acid ester thereof, a pigment and a vehicle therefor according to the so-called dry lithography.

Description

SPECIFICATION A carbonless pressure sensitive copying paper, a desensitizing ink composition therefor and a process for producing carbonless pressure sensitive copying paper This invention relates to a so-called carbonless pressure sensitive copying paper and more particularly to a carbonless pressure sensitive copying paper which has been subjected to desensitized printing according to a new printing system.

Carbonless pressure sensitive copying paper was devised by making use of the color reaction between a colorless basic dye as color forming agent and an acidic material as color developing agent.

Usually, the dye is dissolved in a high-boiling organic solvent, then encapsulized with a high-molecular material and coated on a sheet (top sheet), and such top sheet is used in combination with another sheet coated with an acidic material (bottom sheet). If still another sheet (intermediate sheet) coated with an acidic material on the front side and the colorless dye-incorporated capsules on the rear side is used by placing it between the top and bottom sheets, a greater number of copies can be obtained at one operation.

In case of using such carbonless pressure sensitive copying paper for slips or such, a specific ink, or so-called desensitizing ink, is applied on the front-sided surface of the acidic material coated sheet (intermediate and bottom sheet) usually according to a typographic printing system so as to prevent color formation in the unnecessary portions.

Among the known types of desensitizers contained in the desensitizing ink there are cationic quaternary ammonium salts (such as dodecyltrimethylammonium chloride) shown in Japanese Patent Publication No. 3921/58, tertiary amines having two polyethylene oxide yroups (such as N,N-dipolyoxyethyleneethylamine) shown in Japanese Patent Publication No. 29546/71, polyoxyethylene monoalkyl esters (such as polyoxyethylene oleyl esters) shown in Japanese Patent Publication No. 38201/72, ethylene oxide addition compounds of polyalkylene polyamine shown in Japanese Patent Publication No. 23008/74, glycidyl esters or glycidyl ether addition compounds of polyamine shown in Japanese Patent Publication No. 22416/76.

The desensitizer content in the desensitizing ink for no-carbon pressure sensitive copying paper is usually as hgh as several ten percent, so that the characteristics of the desensitizing ink are greatly affected by the properties of the desensitizer used.

An object of this invention, therefore, is to provide a desensitizing ink of a specified composition, particularly a specific desensitizer used in such Ink, so as to realize desensitized printing according to a new printing system which allows more beautiful finish of printing with less troubles than the conventional systems.

On the other hand, according to the conventional typographic (relief) printing system, desensitizing ink on the plate is directly printed on the surface of the carbonless copying paper, so that this system involed the problem of non-uniformity of the applied ink, while in the case of lithography, ink is more uniformly applied since printing is made after offsetting from the plate.

Also, pressure tends to concentrate on a certain portion of the plate in typography (letterpress), but in the case of lithography, pressure is applied uniformly over the entire surface of the plate, so that when printing is made particularly on the intermediate sheet coated with the capsules, there is less chance of partial break of the capsules than in the conventional typographic system, resulting in reduced troubles and good finish.

The printing systems currently practised in the printing industry may be roughly classified into the following four types: (1) typography, (2) intaglio, (3) lithography, and (4) stencil. However, printing by use of desensitizing ink has been actually practiced in the typographic and intaglio printing systems and could not be employed in lithography which is most prevalent in the general field of printing, and thus usually, printing of slips or such as depended on typographic printing.

Lithography is a printing system using a plate consisting of a lipophilic image portion and a hydrophilic non-image portion, according to which dampening water is first supplied over the entire plate surface and then printing ink is applied, whereby no ink adheres to the hydrophilic non-image portions where dampening water stays but ink adheres selectively on the lipophilic image portions alone, thereby effecting printing.

The desensitizer for desensitizing ink which has been used for carbonless pressure sensitive copying paper is a compound with relatively high hydrophilicity, so that the desensitizing ink containing such compound does not repel dampening water, causing the desensitizing ink to adhere on the nonimage portions of the plate, too. Thus, lithography has been considered unsuited for the printing operation using desensitizing ink.

However, lithography is a most prevalent printing system and lithoprinting is now widely used.

This printing system is also noted for easy plate making and beautiful finish of printing. For these reasons, development of the techniques for printing carbonless pressure sensitive copying paper with desensitising ink according to lithography and development of desensitizing ink used for such printing system have been keenly sought.

The present inventor carried out an intensive study to satisfy the demand, and as a result, developed a desensitizing ink for carbonless pressure sensitive copying paper, which can be applied by dry lithography which has surprisingly been developed in the printing field. Thus the present invention is achieved.

The term "dry lithography" used herein refers to a lithoprinting system which was developed recently in the plate making industry and already commercialized in the certain fields of printing.

According to this method, as described in detail in "PHOTOPOLYMER" (Photopolymer Conversazione, compiled by the Photopolymer Compliation Committee, pub. by C.M.C. Inc. in September, 1977, pp.308-316), ink is allowed to adhere to the image portions alone without supplying any dampening water.

The salient advantage in use of such dry lithography is that it can eliminate or minimise the various troubles and difficulties resulting from supply of dampening water, such as (1) emulsification of ink due to mixing of dampening water into ink, (2) curling and expansion or contraction of the printing paper by dampening water, and (3) adjustment of balance of supply between ink and dampening water, and such advantage of dry lithography is retained in the device of this invention.

As for the desensitizer, the results of the tests on various types of desensitizers which have been used for the commercially sold surfactants and desensitizing inks for typography and flexography showed that most of them are strongly hydrophilic and cause adhesion of ink even to the hydrophilic nonimage portions of the plate, and also, because of strong polarity, the image portions on the plate surface are attacked by the desensitizer and made unusable. However, further studies by the present inventor revealed that a very few of such known desensitizers can be safely used for lithography.

An object of the present invention is to provide a desensitizing ink for no-carbon pressure sensitive sheet, which is suitable for being applied by dry lithography.

Another object of the present invention is to provide a carbonless pressure sensitive copying sheet having a layer of desensitizing agent thereon applied by dry lithography.

The desensitizer for dry lithography provided according to the present invention has high desensitizing effect, is strongly lipophilic and does not attack the plate surface, and the desensitizing ink composition comprises (A) a polymer compound having a surface activity selected from a poly(oxypropylene)glycol or triol, a poly(oxypropylene-oxyethylene)glycol or triol having propylene oxide component and ethylen oxide component in a ratio of 100:65 or below, a monovalent aliphatic alcohol or a phenol adduct thereof and a carboxylic acid ester thereof as desensitizer, (B) a pigment and (C) a vehicle therefor.

Also, the carbonless pressure sensitive copying paper of the present invention may be prepared by printing the above desensitizing ink onto the color developing layer of acidic material of a carbonless copying sheet by dry lithography.

Among the polymer compounds used in the present invention, the monohydric alcohol or phenol for the adduct may include a C1-C10 saturated or unsaturated alcohol which may contain a substituent such as a phenyl group or a phenyl which may contain C1-C10 alkyl groups.

The carboxylic acid for the ester may include a saturated or unsaturated aliphatic or aromatic carboxylic acids including mono- or di-carboxylic acids, and are preferably C1g fatty acids such as capric acid, lauric acid, stearic acid, caproleinic acid, oleic acid or such. The ester may be esterified either with a part or whole parts of the terminated hydroxyl group of the polymer.

Referring to formula of the polymer compound used in the invention, the following may be mentioned:

wherein R, and R2 which may be same or different are a hydrogen atom, a C,C,O saturated or unsaturated aliphatic hydrocarbon group which may have as substituent, a phenyl group which may have a C1-C10 alkyl group or a -COR3 group wherein R3 is a C5-C18 saturated or unsaturated aliphatic hydrocarbon group or an aromatic group, which may have a carboxyl group, 1, m, m', m", m"', n, n', n" and n"' which may be the same or different are independently a positive integer, provided that m is not less than 7 and they satisfy the following conditions: m = m' + m" + m"', I + n = n + nii + n"' which may be equal to zero and m:l + n = 100:65-0.

The polymer compound used as desensitizer in the present invention is well known as a nonionic surfa ctant, defoamer or intermediate for polymers and sold. The poly(oxypropylene-oxyethylene)glycol or triol may be a random or block copolymer, and the triol means a polymer or a copolymer having three terminal hydroxy groups, which may be prepared by an ordinary method comprising polymerizing or copolymerizing propylene oxide alone or with ethylene oxide in the presence of a trihydric alcohol such as glycerol and trimethylolpropane as intitiator.

The polypropylene oxide which is a basic component of the polymer compound in this invention may be one having an average molecular weight of about 500 to about 4000.

It is to be noted, however, that a high'proportion of polyoxyethylene leads to a strong hydrophilic nature of the desensitizer resulting in a strong desensitizing effect, while a high proportion of polyoxypropylene results in a weak desensitizing effect but a high adhesiveness of ink to the dry lithoprinting plate, so that it is essential to select appropriately the ratio of propylene oxide component: ethylene oxide component depending on the kind of the dye or color developer used in the no-carbon pressure sensitive copying paper.

As a result of studies on carbonless pressure sensitive copying papers containing a dye and a color developer in various combinations, the present inventors found that the more desirable results are obtained by using a polymer compound appropriately selected from those in which the molar ratio of propylene oxide component: oxyethylene component is 100:47 or less in the case of the copolymer itself, 100:33 or less in the case of its adduct and 100:65 or less preferably 100:47 or less in the case of the carboxylic acid ester. The poly(oxypropylene) glycol or triol itself is also usable depending on the kind of the dyes and color developers.

These polymer compounds, when used as desensitizier in desensitizing ink for dry lithography, prove to be advantageous over other known desensitizers as to the following points: 1) Sufficient desensitizing ink adhesion to the image portions of the plate is provided to ensure the required desensitizing effect.

2) Ink does not adhere to the non-image portions of the plate, causing no staining on other parts than the printed portions.

3) No attack to the plate surface is caused.

The polymer or copolymer itself used in the invention is exemplified in.the following Table 1.

TABLE 1 mol mol mol Compound propylene ethylene ratio No. Compound name oxide oxide 1 Polypropylene oxide (diol) 17 0 100:0 Ave. mol. wt.: approx. 1,000 2 Polypropylene oxide (diol) 34 0 100:0 Ave. mol. wt.: approx. 2,000 3 Polypropylene oxide (triol) 51 0 100:0 Ave. mol. wt.: approx. 3,000 4 Polypropylene oxide (triol) 68 0 100:0 Ave. mol. wt.: approx. 4,000 5 Ethylene oxide (20%) /propyoene oxide copolymer (using propylene oxide (diol) with ave. mol. wt. of approx. 1,000 17 4 100:23 6 Ethylene oxide (20%) /propylene oxide copolymer (using polypropylene oxide (diol) with ave. mol. wt. of approx. 2,000) 34 9 100:29 7 Ethylene oxide (20%) /propylene oxide copolymer (using propylene oxide (triol) with ave. mol. wt. of approx. 3,000) 51 13 100:25 8 Ethylene oxide (30%/propylene oxide copolymer (using polypropylene oxide (triol) with ave. mol. wt. of approx. 4,0001 68 18 100:28 9 Ethylene oxide (10 M0)/propylene oxide copolymer (using poly propylene oxide (triol) with ave. mol. wt. of approx. 51 7 100::14 10 Ethylene oxide (35%/propylene oxide copolymer (using poly propylene oxide (triol) with ave. mol. wt. of approx. 3,000) 51 24 100:47 11 Ethylene oxide (35%) /propylene oxide copolymer (using poly propylene oxide(diol) with ave. moi. wt. of approx. 2,000) 34 16 100.47 The alcohol or phenol for the adduct of the polymer compound used in the present invention may include, for example, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol or allyl alcohol as the alcohol, and phenol, cresol, ethylphenol, propylphenol, butylphenol, amylphenol, hexylphenol, heptylphenol, octylphenol or nonylphenol as the phenol.

Examples of the polymer compounds represented by the formula

wherein RX, I and n are the same as above, are shown in the following Table 2.

TABLE 2

Compound No. l m I+n m: I+n 1 ethyl 10 0 100:0 2 ethyl 17 0 100:0 3 isopropyl 17 0 100:0 4 isopropyl 26 0 100:0 5 octyl 10 0 100:0 6 octyl 17 0 100:0 7 phenyl 10 0 100:0 8 phenyl 17 0 100:0 9 benzyl 26 0 100:0 10 pmethylphenyl 17 0 100:0 11 p-octylphenyl 10 0 100:0 12 pnonylphenyl 17 0 100::0 13 ethyl 10 2 100:20 14 isopropyl 17 4 100:23 15 octyl 26 5 100:25 16 phenyl 10 3 100:30 17 benzyl 17 4 100:23 18 pmethylphenyl 26 5 100: 19 19 poctylphenyl 10 2 100:20 20 p-nonylphenyl 17 4 100: 23 Listed below (Table 3) are some typical examples of the ester compounds used in this invention, such compounds being merely cited here for the purpose of exemplification and not restrictive of the scope of this invention.

TABLE 3

Average molecular Molar ratio of Compound weight of poly- propylene oxide: No. propylene oxide ethylene oxide Carboxylic acid Esteritication 1 1000 (diol) 100:0 Lauric acid mono 2 1000 (diol) 100:0 Stearic acid di 3 1000 (diol) 100:12 Capric acid mono 4 1000 (diol) 100:23 Lauric acid mono 5 2000 (diol) 100:0 Caproicacid mono 6 2000 (diol) 100::0 Stearic acid di 7 2000 (diol) 100:12 Capric acid mono 8 2000 (diol) 100:26 Palmitic acid di 9 3000 (triol) 100:0 Stearicacid di 10 3000 (triol) 100:0 Oleic acid di 11 3000 (triol) 100:4 Lauricacid mono 12 3000 (triol) 1000:14 Caproic acid mono 13 3000 (triol) 1000:27 Stearic acid di 14 3000 (triol) 100:27 Palmitic acid mono 15 3000 (triol) 100::47 Stearic acid di 16 3000 (triol) 100:47 Oleic acid di 17 4000 (triol) 100:0 Capric acid mono 18 4000 (triol) 100:0 Palmitic acid mono 19 4000 (triol) 100:26 Lauricacid di 20 4000 (triol) 100:47 Stearic acid di The pigment (B) in the ink composition according to this invention may be selected from the inorganic pigments generally used for printing ink, such as for example, titanium dioxide, zinc oxide, calcium carbonate, clay, etc.

The vehicle (C) therefor may be prepared from a resin generally used for lithographic printing ink, such as for example rosin-modified phenol resin, alkyd resin, maleic acid resin, estericacid resin or a blend of these resins, such resin or blend thereof being dissolved in the desensitizer itself or with a vegetable oil or a suitable solvent.

If necessary, other additives such as ultraviolet absorber, antioxidant, viscosity modifier, stabilizer, lubricant, dye, pigment, etc., may be added in small quantities.

The desensitizing ink for dry lithography according to this invention can be prepared in the same way as ordinary lithographic printing ink, but the component materials may be blended in the following proportions: (A) polymer compound: 25-60 parts by weight; (B) pigment: 10 40 parts by weight; and (C) vehicle; 20-80 parts by weight, and the blended mixture may be uniformly admixed under heating to obtain a printing ink.

The invention is described in further detail hereinbelow by way of some examples thereof in which parts therein are by weight. The dry lithographic printing plate used in these examples was one made by Toray Co., Ltd.

EXAMPLE 1 Rosin-modified phenolic resin ("Tamanol" 135, Arakawa Chemicals) 30 parts Linseed oil 10 parts Ethylene oxide (35%)/propylene oxide copolymer (using polypropylene oxide (triol) with ave. mol. wt. of approx. 3,000) ("Actinol" P-3035, Matsumoto Yushi) 40 parts Titanium oxide 20 parts EXAMPLE 2 Rosin-modified phenolic resin ("Tamanol" 135, Arakawa Chemical) 30 parts Linseed oil 10 parts Ethylene oxide (20%)/propylene oxide copolymer (using polypropylene oxide (triol) with ave. mol. wt. of approx. 3,000) ("Actinol" P3035) 40 parts Titanium oxide 20 parts EXAMPLE 3 Maleic acid resin ("Malkeed" No. 33, Arakawa Chemicals) 30 parts Linseed oil 10 parts Polypropylene oxide (triol), ave. mol. wt.: approx.

3,000 (Wako Pure Chemical Industries) 40 parts Titanium oxide 20 parts COMPARATIVE EXAMPLE 1 Polyethylene oxide (m.w. = 350) propylphenol ether (a desensitizer disclosed in Japanese Pat.

Pub. No. 38201/72) was used in place of ethylene oxide (35%)/propylene oxide copolymer (m.w. = 3,000) of EXAMPLE 1.

COMPARATIVE EXAMPLE 2 Polyoxyethylene laurylamine (a desensitizer disclosed in Japanese Pat. Pub. No. 29546/71) was used in place of polypropylene oxide (m.w. = 3,000) of EXAMPLE 3.

EXAMPLE 4 Maleic acid resin (Malkeed No. 33) 30 parts Linseed oil 10 parts Polypropylene oxide (10 mol) nonylphenol adduct 40 parts Titanium oxide 20 parts EXAMPLE 5 Maleic acid resin (Malkeed No. 33) 30 parts Linseed Oil 10 parts Propylene oxide (17 mol) - octyl alcohol aduct 40 parts Titanium oxide 20 parts EXAMPLE 6 Maleic acid resin) (Malkeed No. 33) 30 parts Linseed oil 10 parts Propylene oxide (17 mol)/ethylene oxide (4 mol) copolymer-nonylphenol aduct 40 parts Titanium oxide 20 parts COMPARATIVE EXAMPLE 3 Polyethylene oxide (ave. mol. wt. 350) propylphenol aduct (a desensitizer disclosed in Japanese Pat. Pub. No. 38201/72) was used in place of the polypropylene oxide-nonylphenol aduct of EXAMPLE 4.

COMPARATIVE EXAMPLE 4 Polyoxyethylene laurylamine (a desensitizer disclosed in Japanese Pat. Pub. No. 29546/71) was used in place of the propylene oxide-nonylphenol aduct of EXAMPLE 4.

EXAMPLE 7 Rosin-modified phenolic resin ("Tamanol" 135) 30 parts Linseed oil 10 parts Polyoxyethylene (20%)/polypropylene glycol (ave. mol. wt. 3,000) monooleate ("Burian" P-3035 OL, Matsumoto Yushi 40 parts Titanium oxide 20 parts EXAMPLE 8 Rosin-modified phenolic resin ("Tamanol" 135) 30 parts Linseed oil 10 parts Polyoxyethylne (35%)/polypropylene glycol (ave. mol. wt. 3,000) dioleate ("Burian" P-3035 DOL) 40 parts Titanium oxide 20 parts EXAMPLE 9 Maleic acid resin (Malkeed No. 33) 30 parts Linseed oil 10 parts Polypropylene glycol (av. mol. wt. 3,000) distearate ("Noniolate" 3,000 P-DS, Kyoie Yushi) 40 parts Titanium oxide 20 parts COMPARATIVE EXAMPLE 5 Polyethylene oxide (ave. mol. wt. 350) propylphenol ether (a desensitizer disclosed in Japanese Pat.Pub. No. 38201/72) was used in place of polyoxyethylene (20%)/polypropylene glycol (ave. mol.

wt. 3,000) monooleate of EXAMPLE 7.

COMPARATIVE EXAMPLE 6 Polyoxyethylene laurylamine (a desensitizer disclosed in Japanese Pat. Pub. No. 29546/71) was used in place of polypropylene (ave. mol. wt. 3,000) distearate of EXAMPLE 9.

EXAMPLE 10 The component materials shown in EXAMPLES 1-9 and COMPARATIVE EXAMPLES 1-6 were well mixed and dissolved under heating respectively to prepare printing inks, and these inks were subjected to dry lithographic printing on the bottom sheet (N 40) of MITSUBISHi NCR paper, a .commercially sold carbonless pressure sensitive copying paper, by a lithoprinter using a dry lithograph without suppling dampening water.

As a result, desensitizing inks of the said EXAMPLES showed good selective adhesion, allowing clear printing of the image portions alone, while the inks of COMPARATIVE EXAMPLES adhered to the entire plate from the early phase of printing, creating a condition incapable of performing desensitized printing. By this time, the dry lithographic surface has already been attacked by the desensitizer.

When the top sheet (N--40) of MISTUBISHI NCR paper was placed on the plate portions printed with the desensitizing inks of the said EXAMPLES and subjected to typewriting, a satisfactory desensitizing effect was provided.

Claims (17)

1. A desensitizing ink for a carbonless pressure sensitive copying paper which is capabSe of printing the paper by dry lithography, which comprises (A) a polymer compound having a surface activity, as desensitizer, selected from a poly(oxypropylene)glycol~or triol, a poly(oxypropyleneoxyethylene)glycol or triol having propylene oxide component and ethylene oxide component in a ratio of 100:65 or less, a monohydric aliphatic alcohol or a phenol adduct thereof and a carboxylic acid ester thereof, (B) a pigment and (C) a vehicle therefor.

2. The desensitizing ink of Claim 1, wherein the polyoxypropylene moiety in the polymer compound has a molecular weight of about 500 to about 4,000.

3. The desensitizing ink of Claim 1 or Claim 2, wherein the polymer compound is a poly(oxypropylene)glycol or triol or a poly(oxypropylene-oxyethylene)glycol or triol having a molar ratio of propylene oxide component: ethylene oxide component of 100:47 or less.

4. The desensitizing ink of Claim 1 or Claim 2, wherein the polymer compound is a poly(oxypropylene-oxyethylene)glycol - a monohydric aliphatic alcohol or a phenol adduct having a molar ratio of propylene oxide component: ethylene oxide component of 100:33 or less.

5. The desensitizing ink of Claim 1 or Claim 2, wherein the polymer compound is an ester of a poXy(oxypropylene-oxyethylene)glycol or triol having a molar ratio of propylene oxide component: ethylene oxide component of 100:65 or less with a carboxylic acid.

6. The desensitizing ink of Claim 1 or Claim 2, wherein the monohydric aliphatic alcohol is a C1-C10 saturated or unsaturated alcohol.

7. The desensitizing ink of Claim 1 or Claim 2, wherein the phenol is a phenol which may have a C1C1O alkyl group.

8. The desensitizing ink of Claim 1 or Claim 2, wherein the carboxylic acid is a fatty acid having a C5-C18 saturated or unsaturated aliphatic hydrocarbon group.

9. The desnsitizing ink of Claim 1 or Claim 2, which contains 25-60 parts by weight of the polymer compound,10 40 parts by weight of the pigment and 20-80 parts by weight of the vehicle.

10. The desensitizing ink of Claim 1 or Claim 2, wherein the polymer compound is represented by the formula,

wherein R1 and R2 which may be same or different are a hydrogen atom, a C1C10 saturated or unsaturated aliphatic hydrocarbon group which may have as substituent a phenyl group which may have a C1-C10 alkyl group, or a -COR3 group wherein R3 is a C5C18 saturated or unsaturated aliphatic hydrocarbon group or an aromatic group, which may have a further carboxylic group, I, m, m', m, rn'1,, n, n', n" and n"' which may be same or different are independently a positive integer provided that m is not less than 7 and they satisfy the following conditions: m = m' + m" + m"', I + n = n' + n" + m"' which may equal to zero and m:l + n = 100:65--0.

11. A process for producing a no-carbon pressure sensitive copying paper desensitized by printing, which comprises printing on the color developing acidic substance layer of a no-carbon pressure sensitive paper which comprises a support and said acidic material layer thereon a desensitising ink of Claim 1 by dry lithography without supplying any dampening water.

12. A desensitizing ink composition according to Claim 1 substantially as herein described and exemplified.

13. A process according to Claim 11 substantially as herein described and exemplified.

14. A carbonless pressure sensitive copying paper which has been obtained by the process claimed in Claim 11 or Claim 13.

1 5. A carbonless pressure sensitive copying paper having a color developing acidic material layer for developing color when contacted with a colorless dye and which is adapted to be sufficiently desensitized on a portion which is not desired to be given an image by printing on the portion a desensitizing ink composition comprising a poly(oxypropyiene)glycol or tripol, a copolymer thereof which polyoxyethylene, an aliphatic alcohol or a phenol adduct thereof, or a carboxylic acid ester thereof, a pigment and a vehicle therefor.

1 6. A carbonless pressure sensitive copying paper according to Claim 1 5 substantially as herein described and exemplified.

17. The invention substantially as herein described.