PH26577A - Carbonless copy paper - Google Patents

Description

SE 26577 fone 1 This Invention relates to "carbonfeFs” UN 2 copy paper. {a hor © 1 | Horany Ji 3 Carbonless copy paper is really a Le Fe 141/n0 wf 4 sure sensitivecolour transfer system havitig =~... yf color transfer and colour developer sheets’ ‘AL 82> 6 This invention also Includes process 7 of preparation ofcolour former microcapsules 8 for the carbonless copy paper and the micro- 9 capsules so produced.

The present invention further Includes i1 a process of preparation of colour developer 12 for the colour transfer system used in carbon- 13 less copy paper and the colour developer. 14 The invention also encompasses process of making the carbonless copy paper, color 16 developer sheet and color developer syste. 17 Carbonless copy paper usually consists 18 of two or more sheets of coated paper. For 19 example, when three sheets of paper are used, the top sheet has a coated back(CB) which 21 is formed by coating in the back or underside 22 of the top sheet with a composition containing 23 microcapsules whichis prepared by dispersing 24 an oil containing a colorless electron donating chromogenic color former in a hydrophilic 26 colloid solution. The middle sheet is coated 27 on its front and back (CFB). The coatingon 28 the front or upperside contains anelectron 29 accepting color developer, and the coating on the back or underside is the same as the 31 microcapsule-containing coating on the top 32 sheet. The bottom sheetis coated on its upper- 33 side or front (CF) with the same composition 34 that is on the front of the midle sheet. Deta- jled disclosures of carbonless copy papers 36 are included in U.S. Patents 3,554,781; 37 4,154,462; 4,337,968; 4,352,855; 4,371,634 38 and 4,4411,451. . 39 in order to form an Image with carbonless 40 copy paper, the system utilizes the color 41 forming reaction that takes place between 42 the electron donating chromogenic material

RL ROY AD ORIGINAL

- 2 - TOYTARY

Pope a, 141160

Youoikahdl Rises

. . , . fe EER

C, D ] or color former in the costed back and Hiciron 2 acc pting acidic reactant material or c nar a3 3 developer in the scated front (CF). The redttant 4 are isolated from each other by microencapsulating one of them until an image Is desired. When pressure 6 is applied to the carbonless copy paper, the 7 microcapsules are ruptured and a reaction occurs 8 between the color former and color developer to 9 provide the desired image. In the preferred type of carbonless copy paper, the color former is 11 the reactant that is encapsulated by being dissolved 12 in oll and microencapsulated prior to being used 13 in the coating on the coated back. 14, A preferred method of making microcapsules containing color former reactants is the complex 16 coacervation procedure described in U.S. Patent 17 2,800,457. In this procedure an oil containing a 18 color former Is dispersed in two colloid materials 19 that have opposite charges, and at least one is gellable, Coacervation of the hydrophilic colloid 21 solution around each oil droplet is caused by 22 dilution and adjusting the pH to the acidic range. 23 The coacervate around each oil droplet is gelled 24 by cooling and hardened by addition of a suitable hardening agent, and the pH of the mixture is 26 adjusted to the alkaline range, 27 Carbonless copy papers that are produced 28 from multi-nuclear and clustered microcapsules 29 are subject to premature rupturing of the microcapsules during handling or during post- 31 coating conversion processes, especially in the 32 printing of business forms. Also, such copy 33 papers hove very poor humidity and heat resistance, 34 and those copy papers have only very limited utility tn hot, humid climates. Much effort has . 36 been expended to solve these problems by preparing 37 coacervation microcapsules that are mononuclear 1g, I, ROY,

HOTARY -3- BAD ORIGINAL

Regn. ilo. 141]80 -

A, sankshall Sreaet

Calestre-—=t :

. Lo ey Oa

CF

HE 5) 1 and cluster-free. For example, malelc anhydride }’ J. 141 /an/ TF 2 copolymc-s or carboxymethyl cellulose have been Nowrnorarsds 3 into the walls of the microcapsules, but these ori HAL Ge 4 art procedures have not been successful, although reaction conditions were strictly maintained during the 6 coacervation procedure. 7 Also, there are unsolved problems with the coated 8 fronts that are used in prior art carbonless copy papers. 9 Usually an acidic clay or an acidic polymer is used in the coated front. Images on acidic clay-coated paper are 11 not sufficiently permanent and they have only limited 12 resistance to moisture. Images on acidic polymer -coated 13 paper are time and temperature dependent and frequently 14 too slow. Better results are sometimes obtained by using a combination of acidic clay and acidic polymer, but image 16 formation is still too slow, especially at low temperatures 17 such as at 5°C. 18 SUVMARY OF THE INVENTION 19 It is an object of this invention to provide an improved carbonless copy paper that does not have the 21 problems and disadvantages discussed above. 22 It is another object of thls invention to 23 provide an jmproved carbonless copy paper having the 24 color former in microcapsules that are mononuclear and substantially cluster-free and are resistant to premature 26 rupturing, especially at high humidity and high 27 temperature. 28 It is a further object of this invention to 29 provide an improved carbonless copy paper having a faster image formatinn capability, especially at low 31 temperatures. © 32 DETAILED DESCRIPTION :

BAD ORIGINAL

EI fH ERY “4 —

MOL aAny

Peon. Ka. 14190

A Gienk shall Hives

Cl sdeannzar.

Fon 2 4 220 ! In accordance with this Invention, we dias pv |)? ; ’ OTARY 2 found that an improved carbonless copy paper a no. 141/80/ 3 has an improved resistance to smudging at high 4

Co 4 and humidity can be prepared by dispersing an oil LLIN containing an electron donating chromogenic color 6 former In a hydrophilic colloid solution to form 7 microcapsules that are mononuclear and cluster-free. 8 The hydrophilic colloid solution contains a water 9 soluble graft copolymer having a backbone of carboxymethyl cellulose or gum arabic and side chains of polyacrylic 11 acid or polymethacrylic acid, said side chains comprising 12 from 5 to 10 per cent by weight of the copolymer. 13 The hydrophilic colioid solution is coated on 14 one side of a sheet of paper to form a pressure-sensitive color transfer sheet, and the color transfer sheet is 16 placed in contact with an electron accepting color 17 developer that has been coated on a second sheet of 18 paper. The resulting system is a pressurc-sensitive 19 carbonless copy paper that is resistant to smudging at high temperature and high humidity. 21 We have also found that the image response 22 time of the second sheet of paper containing the 23 color developer can be improved, particularly at low 24 temperatures, such as 5°C, by incorporating pectin or sulfated starch in the acidic coating containing the 26 color developer. 27 The coacervation procedure that is described ' 28 in U.S. Patent 2,800,457 is suitable for preparing 29 the microcapsules containing color forming material that are used in preparing the carbonless copy paper 31 of this invention. The preferred hydrophilic or 32 colloid material that is used is an acid-treated gelatin; 33 and in order to obtain mononuclear, cluster-free 34 microcapsules, a graft copolymer is used with the . 35 acid-treated gelatin. i

SLE ay Cs. BAD ORIGINAL i. K, ROY) TT

NOTARY

Regn. No, 141/50 3. Jankshall Strecr

Codeveegg-—)

Co 2h 200 (i RK ROY\% orany J?

HO. 111/80 / ¥ 1 The graft copolymer contains carboxymetHY oy Seer SA 2 cellulose (QC) or gum arabic (GA) as a backbone "HiL, 2 3 polyacrylic acid or polymethacrylic acid in the he 4 side chains. The graft copolymers are carboxymethyl cellulose with polyacrylic acid (QXC-PAA) or 6 polymethacrylic acid (GMC-PMA), and gum arabic with 7 polyacrylic acid (GA-PAA)} or polymethacrylic acid 8 (CA-PMA). 9 The graft copolymers that are used contain from 5% to 10% by weight of polyacrylic acid (PAA) 11 or polymethacrylic acid (PVA). When less than 5% 12 by weight {s used, the benefits of our invention 13 are not achieved; and when more than 10% by welght 14 is used, the microccpsules have been found to agglomerate. 16 The amount of copolymer that is used, when 17 expressed In relation to the amount of gelatin or 18 other hydrophilic colloid material, is within the 19 range of 1/8 to 1/4 or 12.5% to 25% by weight.

The graft copolymers that are used can be 21 prepared by a free radical polymerization technique. 22 Free radicals are created on the carboxymethyl 23 celtulose or gum arabic backbone by higher valence 24 metallic lons, and the acrylic acid or methacrylic acid monomers are polymerized mainly on the chain 26 of the substrate polymer. The graft copolymers can 27 then be purified by the solvent-nonsolvent technique. 28 The carboxymethyl cellulose that 1s used 29 to form the graft copolymers has an average degree of polymerisation (DP) of 200-500 and a degree of . 31 substitution (DS) of 0.6 to 0.8. Commercial grades : 32 of gum arabic, acrylic acid, and methacrylic acid . 33 are also used.

Cae 6.

KK, ROY, BAD ORIGINAL

NOTARY

Regm. No, 141/80 3, Bunkshall Strer!

Culcstin---F

} , FN dk K. ROY\% x voimey |? } 1 Chromogenic materials that can be Gon ” 2 color formers are crystal violet lactone, benedgl. oo 3 leucomethylene blue, malachite green lactone, 4 rhodamine B-lactone, and fluoran derivatives, either alone or in combination. 6 Conventional hydrophobic materials are used, 7 either alone or in combination. Typical examples are 8 castor oil, alkyldiphenyl, biphenyl derivatives, 9 naphthalene derivatives, alkylbenzene phthalic acid esters, and kerosene. 11 Coacervate hardening agents are also used, 12 either alone or in combination. Suitable agents are 13 formaldehyde, glyoxal, and glutaraldehyde. From 3-30 14 parts by weight of hardening agent per 100 parts of hydrophilic colloid material are used. 16 The preferred color developers are acidic 17 polymers of thermoplastic materials having good 18 solubility in oil. A preferred polymer is p-substituted 19 phenol -formaldehyde novolac resin. The resin can be used in combination with an absorbent such as kaolin, 21 attapulgite, and precipitated silica. In the polymer 22 p-chloro phenol, p-octyl phenol, or p-tertiary butyl! phenol 23 can be used in place of p-phenyl phenol. 24 Binders that can be used with the color developers are polyviny! alcohol, styrene-butadiene 26 rubber (SBR) latex, carboxymethyl cellulose, hydroxyethyl 27 cellulose, oxidized starch, and polyvinyl acetate 28 emulsion. The most preferred binders are oxidized 29 starch and styrene-butadiene rubber latex.

Anionic, cationic, and nonionic emulsifying 31 agents can also be used with the color developer. 32 Preferred emulsifiers are teepol, turkey red oil, . be HW, ROY

LUAIAES BAD ORIGINAL

Regn. No, 14140 ——— 3, ankshall Su dover

A ow ay le : A hm

Ou “leg \ 1 tetrasodium pyrophosphate, cetyltrimethy! amef 1101)

HOTARY |° 2 chloride, and polyoxyethylene dodecyl sulfonic (8clde, y4y/a nf 3 Suitable protective agents for the color develod8y, of 4 are pectin, pectic acid, dialdehyde starch, sul fatedar A497 starch, and ureaformaldehyde polymers. Sulfated starch 6 and pectin are preferred. 7 The amount of pectin or sulfated starch that 8 is used Is within the range of 3 to 8% by weight of 9 the color developer, for example, p-pheny] phenol formaldehyde resin. When sulfated starch is used, it 11 is preferred that the degree of esterification be 12 within the range of 0.55 to 0.65. 13 The following examples illustrate our invention. 14 In these examples, parts and percentages are by weight unless otherwise indicated. 16 Preparation of Color Former Microcapsules: 17 Example 1 18 100 parts acid treated gelatin is dissolved in 1200 19 parts water at 45°C and 600 parts KMC-113 (alkylnapthalene! containing 12 parts crystal violet lactone js emulsified 21 into the gelatin solution to 3 particle size of 5-8. 22 To the emulsion, 1000 parts 2.5% QMC solution (DP=300 23 & DS=0.6) in water is added gradually under mild 24 stirring. Then 3000 parts warm water are added and stirred for another 15 minutes. The pH of the mixture 26 is adjusted to 5.0-5.5 with 10% sodium hydroxide in 27 water. The mixture is then cooled externally under 28 constant stirring and 50 parts of formaldehyde (37%) 29 is added to 1t. The pH of the system is then adjusted to 10.0 with 10% sodium hydroxide solution. 31 Example il 32 Example 1 is repeated by using a ax (DP=300 & DS=0.6)- . 2. 16 ROY. BAD ORIGINAL

CC noTAnRY fran. No. T4150 3. tionk shall Stee tpdosttg fF {

’ ’ , Co a oh b 2p $ 5

JR K ROY\z

NOTARY |’ 1 graft copolymer containing 10% PAA, instead o . 141/09 /% 2 alone. Ns

AL = 3 Example 111 4 Example 1 is repeated by using a OIC (DP=300 & DS=0.6)- graft copolymer containing 10% PMA, instead of using 6 MC alone. 7 Example 1V 8 Example | is repeated by using 100 parts of gum arabic 9 (GA) in place of carboxymethyl cellulose {OMC).

Example V

I Example 1 is repeated by using a GA-graflt copolymer 12 containing 10% PAA in place of OQWC alone. 13 Example VI 14 Example | is repeated by using GA-graft copolymer containing 10% PMA in place of OMC alone. 16 To each of the above capsule dispersions, 17 I50 parts cellulose powder, 75 parts starch, and 200

Ig parts 10% partially hydrolysed polyvinyl alcohol are 19 added and the final composition coated at 5 g/m2 onto a 50 g/m? base paper. 21 The coated papers with microcapsules (Examples 22 1-V1}, i.e. the CB sheets, are tested by using the 23 following procedures and the results are presented 24 in the comparative analytical table (Table I).

Test Procedures: 26 (i) Capsule nature and cluster 27 This test is done with a microscope of 1500x . 28 magnification by taking capsule suspensions

A

-g- BAD ORIGINAL

FLW ry —

NF ALS

Regn. fo. 141.00 ¥ Manksheid See alpen, . A

. en 24

Se my 3 RK ROY\z\ ] onto a slide and counting the number 1 NOTARY J? i 2 clusters per 100 capsules under the grin] 3 (it) Heat and humidity resistance Rar 4 Coated papers from the capsule suspensions oT are kept in an air oven at 150° + 2°C for 6 testing heat resistance and in a humidifier at 50° 7 + 0.5°C and 98% RH for testing the humidity 8 resistance. 9 (iii) Humidity resistance under weight

This is considered to be a measure of the 11 smudge resistance of the carbonless paper. 12 Coated papers from the capsule suspensions (CB) 13 are placed on the CF coated papers face to 14 face, under weight in a humidifier at 50° * 0.5°C and 938% RI. 16 (iv) [Hardening time 17 This is the time required for dropwise addition 18 of a sodium hydroxide solution in water to 19 make the pil of the prematured capsule suspension at 10°C reach the range of 21 10.0-10.5. 22 TABLE 1 23 Carnparative Analytical Tabel ((B) 24 Cluster/Heat Humidity “*Hhmidity Hardening

Example Capsule Shape 100 Resis- Resis- Resistance Time 26 Capsules tance tance under Welght (minutes) 27 1 2 3 4 5 6 7 28 1 Mixture of 15 +5 4 hrs. 1/2 hr. 1/4 Kg/ in? @ 40 + 5 29 Multi-nuclear at @ 50°C 50°C & 98&h RH & Nononuclear 150°C & 98% RH for 1/4 hr. 31 11 Nononuclear 1 7 hrs. | hr. 1/2 Kg/1n% 15 + 5 32 at 50°C 50°C & 980 Rl 33 150°C & 9&1 for 1/2 hr. 34 111 Mononuclear 7 hrs 1 hr. 1/2Kg/in’@ 15 +5 at @0°C 50°C & 98% Rl . 36 150°C & 9% for 1/2 hr. -10-

RLFC BAD ORIGINAL

MOTAR

Regn. Nn. 141s¢ 3, Peakshed 81:

Cover?

p

J 20

IVMulti-nuclear 25 +5 3 hrs 1/2 hr. 1/4Ke/in2 @ 45 £57 NA 2 at @0°C 50°C & 98% Ri! J/R K ROY\% 3 150°C & 99% RI for 1/4 hr. ane 4 V Mononuclear 5+ 2 6 hrs. | hr. 1/2 Kg/ In? 20 a > ly ¥ at @50°C 50°C & 98% RI! ’ La a 6 150°C & 98% Rl for 1/2 hr. mr 7 VI Lononuclear 5+ 2 6 hrs. | hr. 1/2Kg/in2 0 20 + 5 8 at @50°C 50°C & 98% HI g 150°C & 98431 for 1/2 hr.

This test has been done by keeping both weight 11 and time as variables. 12 It is observed that for Examples 11, [I11, V, and 13 VI, the resistance is almost four times (giving equal 14 emphasis to weight and time) that of Examples I andIV.

The following observations are found with the CB 16 coated papers and the microcapsules used for making 17 the CB sheets according to the process of the invention 14 (Examples 11, 111, V, and VI): 19 (i) The average capsule size is 5-8 pn. (ii) For all practical purposes, the microcapsules 21 are mononuclear and cluster-free when compared 22 to those obtained in Examples | and IV. 23 (iii) The humidity resistance of the CB sheets is 24 relatively higher, (iv) The humidity resistance under weight, or in 26 other words the smudge resistance of the microcapsule 27 coatings, is far better than that as obtained 28 in Examples | and IV. 29 {v) The coated papers are not affected when stored at lower temperatures like 5°C. 31 (vi) Up to seven clear copies on 50 g/m? base paper 32 are obtained. 33 Preparation of Color Developer: 34 Example A . 35 60 parts precipitated silica and 40 parts kaolin are .

A 38 dispersed in 180 parts water under stirring. To the

S11- 3. 18, ROY BAD ORIGINAL

NOTADY oo

Rega, No, 111000 1, Nank shall Seer ‘

Colovrta 7

So ~NFE ) F(R K. ROY z . NOTARY

Am on aglen/ dispersion, 100 parts 25% p-pheny! phenol 1orta M¥hyYHY : a) 2 resin, 100 parts 20% oxidized starch sorut ion Mga, 50 3 water, and 20 parts 50% SBR latex are added and m ¥8d” 4 thoroughly in a ball mill.

Example B 6 60 parts precipitated silica and 40 parts kaolin 7 are dispersed in 180 parts water containing 5 parts 8 pectin under stirring. To the dispersion, 100 parts of 9 25% p-phenyl phenol formaldehyde resin, 100 parts 20% oxidized starch solution in water, and 20 parts 11 50% SBR latex are added and mixed thoroughly in a 12 ball mill. 13 Example C 14 Example B is repeated by using 5 parts sulfated starch instead of 5 parts pectin. 16 The final compositions from each of these 17 examples are coated at 5 g/m? onto a 50 g/m? tose 18 paper. Ce 19 These coated papers (Examples A, B and Cc), i.e. the CF sheets, are tested by using the following 21 procedures and the results are presented in the 22 comparative analytical table (Table 11). 23 Testing Procedures: 24 (i) Humidity resistance

This is considered to be a measure of the 26 life of the CF paper in an acceptable active 27 condition. 28 Coated papers are kept in a humidifier at 50°C 29 + 0.5°C and 98% RH for 4 hours. \

INAL

-12- BAD ORIG", oa pe. at LHL poy oan tf oar No, (4180 : vo Condoxidd Spec {adorn /

i | AaB 2p fst ( K. or’

HOTARY

(ii) Image formation 7 \no. 141/79 7 2 CB and CF papers are conditioned at 5 Gago G8 3 0.5°C and tested by writing with a bal) UAL 2 4 point pen. Similar testing is done at 30°C also, 6 (iit) Image stability 7 (a) Water resistance Copies on CF sheets are 8 washed under a stream of 9 tap water, (b) Solvent resistance Copies on CF sheets are 11 rubbed by cotton soaked 12 with benzene, toluene, 13 and acetone. 14 (c) Ultraviolet Copies on CF sheets are resistance kept under an ultraviolet 16 light source situated 17 100nm away from the image. 18 (d) Suntight resistance Copies on CF sheets are 19 exposed to sunlight for hour. 21 TARLE 11 22 Comparative Analytical Table (CF) 23 Example 24 A B C

Moisture resistance of CF paper d* b b 26 Image formation at 30°C b a a 27 Image formation at 5°C d a a 28 Image Stability: 29 Water resistance a a a

Solvent resistance d c c 31 Ultraviolet resistance c Cc c 32 Sunlight resistance d C c — 33 * Ratings: 34 a = very good b = good . 36 ’ c = satisfactory . 37 d = relatively unsatisfactory

Ls HOR. ROY. 19

Ream Mor fel n 54D ORIGINAL

N, Rankshall Steer

Calorie

PALIN

Fm ny

Sr AVAN

F/R K ROY\ZY

I The following obscrvatlions are found with, thdiOTARY

Y\ jo: 141/e0/ 2 CF coated papers and the images developed evel Sa)

Ny mea Vb 3 according to the process of the invention (Examp! $251 oS 4 B and C): Th (i) Image formation is relatively quick at 30°C 6 as well as at 5°C and much faster than that 7 as obtained in Example A. 8 (ii) The coated papers have a relatively good 9 moisture resistance. - 10 (iii) The image stability is good which is demonstrated 11 by the fact that the image has good resistance ! 12 to water, solvents, ultraviolet light, and 13 sunlight. : -14- £87 4th in EA TY

Rpg. feel Io dian INAL oA A, Bankshall Stee BAD ORIG

Caleurte -

Claims (7)

1. oo Jaren S No, {5 RK ror) . ! OTARY |° What is claimed is: AS ra
2. 2 I. A pressure-sensitive color transfer*sfdat % 3 containing an electron donating chromogenic color 4 former for use in combination with a second sheet containing an electron accepting color developer, 6 said color former being dispersed in a hydrophilic 1 colloid solution to form substantially cluster-free 8 microcapsules, the said colloid solution containing 8 a water soluble graft copolymer having a backbone of carboxymethyl cellulose or gum arabic and side chains 11 of polyacrylic acid or polymethacrylic acid, said 12 side chains comprising from 5 to 10 per cent by weight 13 of said copolymer. 14 2. A pressure-sensitive color transfer sheet according to claim | wherein the hydrophilic colloid 16 solution comprises gelatin and the graft copolymer. 17
3. 3. A pressure-sensitive color transfer sheet 18 according to claim 2 wherein the amount of graft 19 copolymer is within the range of 1/8 to 1/4 by weight of the amount of gelatin. 21
4. 4, A carbonless copy paper color transfer system 22 comprising a pressure-sensitive color transfer 23 sheet having one side coated with a layer containing 24 an electron donating chromogenic color former, said layer being In contact with a second layer 26 coated on a second sheet, said second layer containing 27 an electron accepting color developer, said color 28 former being dispersed in a hydrophilic colloid 29 solution to form substantially cluster-free microcapsules, the said colloid solution containing a water soluble 31 graft copolymer having a backbone of carboxymethyl 32 cellulose or gum arabic and side chains of polyacrylic 33 acld or polymethacrylic acid, sald side chains : 34 comprising from 5 to 10 per cent by weight of said . copolymer. Aine, } NER -15- RE Rey BAD ORIGINAL Hat ARY a Reep, Ne, 141/30 1, Bunkshall Stree Coriomrpay 4

   7 iY B24. Co ev nods
5. 5. Acartonless copy paper colour fi) 2 system comprising a pressure sensitive colof¥ \ po. 141/r0 x 3 transfer sheet referred to as top sheet, havigy one. {of 4 side coated with a layer containing an olectroRiAL 82 donating chromogenic colour former, a plurality 6 of further set of sheets, a second layer coated 7 on upper face of each shect of said further set 8 of sheets, said second layer on each such upper 9 face contalning an electron accepting colour developer, said color former being dispersed in a 11 hydrophilic colloid solution to form substantially 12 cluster-free micro-capsules, the said colloid solution 13 containing a water soluble graft copolymer having a 14 backbone of carboxymethyl cellulose or gum arabic and side chains of polyacrylic acid or polymethacrylic 16 acid, said side chains comprising from 5 to 10 per cent 17 by weight of said copolymer, bottom face of each sheet 18 with the exception, if desired, of bottom most sheet, 19 in said further set of sheets, being coated as the bottom face of the top sheet, said second layer being 21 in contact with the said first layer coated on one 22 face of the sheet above it. 23
6. 6. A carbonless copy paper according to claim 4 24 or 5 whereln the hydrophilic colloid solution comprises gelatin and the graft copolymer. 26 7. A carbonless copy paper according to claim 6 27 wherein the amount of graft copolymer is within the : 28 range of 1/8 to 1/4 by weight of the amount of gelatin. 29 8. A carbonless copy paper according to claim 4 or 5 wherein the color developer contalns pectin 31 or sulfated starch. 32 9. A carbonless copy paper according to claim 4 33 or 5 wherein the color developer is p-pheny! 34 formaldehyde resin. ’ . ~16- Lae oe LOW PLY paD ORIGINAL HOraARY Regn. Ne. 14) 00 XQ, Bank shail fore Colonia
7. 7 fo JR K ROY\Z

   ». NOTARY x 1 10. Acolor developer sheet for use in a & rhea Wy; 2 copy paper color transfer syst... having a mi TOA 3 capsulated electron donating chromogenic color 4 said sheet containing pectin or sulfated starch to improve the image response time. 6 11. A color developer sheet according to claim 10 7 containing p-phenyl phenol formaldehyde resin and 8 pectin or sulfated starch. 9 12. Process of preparing colour former microcapsules for use in carbonless copy paper comprising dissolving 11 acid treated gelatin in warn water, emulsifying 12 alkylnapthalene containing crystal violet lactone 13 in said gelatin solution, adding dilute aqueous 14 solution of one or more of a thickening agent such as QC, GA, graft copolymers of GQ. and GA containing 16 PAA, PMA to said emulsion under mitd stirring and 17 adding to it large quantities of warm water, stirring, 18 adjusting the pl thereof to 5.0 - 5.5 with aquous 19 alkali, adding 50 parts of formalde] yde to it, adjusting the pH to 10 with dilute acqueous alkali, to the 21 dispersion so obtained adding cellulose powder, 22 starch and partially hydrolysed polyvinyl alcohol. - 26 14. Process for preparing color developer for 27 use in carbonless copy paper comprising dispersing 28 silica and kaolin in water under stirring, adding 29 to the dispersion so obtained p-pheny! phenol formaldehyde, oxidised starch solution in water 3) and SB? latex and mixing thoroughly, e.g. in a ball 32 mill. 2, K, ROY NOTARY Regn. No, 1418 -17- R, Bankshall Serer Calcurto --F BAD ORIGINAL tested

   Ce Ci Po Lo 1 15. Process as claimed in claim 14 in which water., ., 7 2 in which silica and kaolin are dispersed, contains 3 pectin or sulfated starch. vt