SE433224B - THE NEW TRIARYLMETHAN COMPANIES INCLUDING TWO HETEROCYCLIC GROUPS, THEIR PREPARATION AND USE, AND THE PRESSURE REGISTRATION MATERIALS, CONTAINING THE NEW COMPANIES - Google Patents

Description

7910525-9 the cooler and not the chromogenic material as a solvent solution. Accordingly, one recording material contains a sheet having a coating of microencapsulated color developing solution (CB sheet) and the other contains a sheet having a coating of a water-insoluble substantially chemically neutral pigment on which the chromogenic material is adsorbed. The CB and CF sheets are assembled into a break-through set with the coatings in contact with each other, so that transfer of solvent solution can take place from the CB sheet to the CF sheet.

In order to obtain additional copies, the impact kit may also contain a third recording material, which contains a sheet of CB coating on one side and CF coating on the other. One or more of these sheets (CFB sheets) are placed between the CF and CB sheets in the punch set with each CB coating in contact with a CF coating.

To obtain an image with certain optical properties, different chromogenic materials were normally used in combination. One of the most common of these materials is crystal violet lactone, CVL; 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide) which has been used in combination with other chromogenic materials to obtain a blue or a black image. However, crystal violet lactone has poor color fastness, i.e. poor ability to prevent color fading for an image generated from it. In addition, crystal violet lactone after exposure to the environment including light shows a significant reduction in color formation reactivity, i.e. its ability to provide an image of acceptable intensity upon reaction with a color developer. This decrease in reactivity, which occurs whether the material is microencapsulated or not, is often called CB 'declination in a normal transfer system, and may also be greater if the material is used as a chromogenic solution in certain solvents, such as 2,2, 4-Trimethyl-1,3-pentanediol-di-i-butyrate (TXIB). Despite these disadvantages, however, crystal violet lactone has continued to be used to a very widespread extent in the absence of any commercially available alternative. An object of the present invention is to provide a chromogenic material which can be used to completely or partially replace crystal violet lactone and which has improved color fastness and improved ability to resist a decrease in reactivity. According to the present invention there is provided chromogenic material of the formula: lggHg ÜEZHS NC _ 7- (1-ethyl-2-methylindol-3-IIN in -yl) -7- (4-ethylamino] -2- CZHS N -s, v-ahydro- <:) E: = Û EH3 EZHS furo (3,4-b) pyridin-5-one In addition, this may contain an isomeric compound of the formula: CH3 CZHS furo (3,4-b ) pyridin-7-one H 2 H 5 -Ez 5 5- (1-ethyl-2-methylindol-3-wg -yl) -5- (4-diethylamino-2-EHHS In addition to having improved color fastness and an improved ability to resist reduction in reactivity, the chromogenic material of the present invention referred to herein as pyridyl blue is capable of providing rapid color formation and giving a blue color with excellent intensity and hue stability.

In addition, it also has a very low reactivity gente- _ V? 910525-0 against the base paper. This is important because when used in a normal transmission system there is very little CB discoloration if even any, i.e. the discoloration caused by a reaction between the base paper of the CB sheet and any chromogenic solution that has not been transferred.

Either of the above two isomers can be used as the chromogenic material, although the pyridin-5-one isomer of the invention is more useful. However, it is better to use a mixture of isomers in which the pyridin-5-one isomer is the predominant one. The reason is that the process used for synthesizing the chromogenic material gives a mixture of this kind and a later separation of the isomers by conventional technology is difficult, time consuming and expensive from a commercial point of view.

The present invention also provides a process for the preparation of the chromogenic material defined above characterized in that a keto acid of the formula: uw, AN \ coon / u "is reacted with a compound of the formula B - H wherein an avfA and B are 4- diethylamino-2-ethoxyphenyl and the other is 1-ethyl-2-methylindol-3-yl in the presence of a dehydrating agent.

A suitable type of dehydrating agent is an acid anhydride such as acetic anhydride and the reaction preferably takes place at elevated temperature, for example 65 DEG-750 DEG C.

When A is 1-ethyl-2-methylindol-3-yl, the keto acid is prepared by reacting quinolinic anhydride with 1-ethyl-2-methylindole and the reaction usually takes place at temperatures of 70 DEG-70 DEG.

When A is 4-diethylamino-2-ethoxyphenyl, the keto acid is prepared by reacting quinoline anhydride with N, N-diethyl-m-phenetidine. The reaction usually takes place in a solvent in the presence of a catalyst, such as aluminum chloride and at a temperature of 35 DEG-400 DEG C. Preferably, A is 1-ethyl-2-methylindol-3-yl because the keto acid can then be prepared without solvent and catalyst. . In addition, the resulting two-step process favors higher production of the pyridin-5-one isomer than the two-step process in which A is 4-diethylamino-2-ethoxyphenyl. In fact, the preferred process enables a mixture to be obtained in which the pyridin-5-one isomer constitutes at least 90% to 95% thereof.

The present invention provides another process for the preparation of the chromogenic material defined above, characterized in that quinoline anhydride, 1-ethyl-2-methylindole and N, N-diethyl-m-phenetidine are reacted together in the presence of a dehydrating agents, such as those previously mentioned. However, this method is less preferred.

The chromogenic material of the present invention can of course be combined with other chromogenic materials, to obtain a certain hue and color for a developed image. An advantage of the resulting combination is that it has the chromogenic material of the present invention as an inclusion, as it allows the combination to avoid loss of reactivity. Examples of such other materials include one or more of the following: 3,7-bis (dimethylamino) -10-benzoyl-phenothiazine (benzoyl-leuco-methylene blue, BLMB) 2'-anilino-6'-diethylamino-3'-methylfluorane (N102 ) - 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide (indolyl red); 3,3-bis (1-butyl-2-methylindol-3-yl) phthalide; spiro-7-chloro-2,6-dimethyl-3-ethylaminoxanthene-9,2- (2H) naphthol (1,8-bc) furan; 7-chloro-6-methyl-3-diethylaminofluorane; 3-diethylaminobenzo (b) fluorane; 3- (4-diethylamino-2-ethoxy) -3- (2-methyl-1-ethylindol-3-yl) phthalide; 3- (4-diethylamino-2-butoxy) -3- (2-methyl-1-ethylindol-3-yl) phthalide; and 3,7-bis (diethylamino) -10-benzoylbenzoxazine.

In addition, the chromogenic material of the present invention can be used together with crystal violet lactone as well instead. For a direct acting or normal transfer system, the chromogenic material of the present invention is used alone or in combination as a microencapsulated chromogenic solution. Examples of a suitable organic solvent for the preparation of a chromogenic solution include dialkyl phthalates in which the alkyl groups have 4 to 13 carbon atoms such as dibutyl, dioctyl, dinonyl and ditridecyl phthalates; 2,2,4-trimethyl-1,3-pentanediol diobutyrate (TXIB, US, A 4,027,065); ethyl diphenylmethane (US, A3 996 405) alkyl biphenyls such as mono-i-propyl biphenyl (US, A3 627 581); C 10 -C 14 alkylbenzenes such as dodecylbenzene; diaryl ethers such as diphenyl ether, di (aralkyl) ether such as dibenzyl ether and aryl alkyl ethers such as phenylbenzyl ether; liquid dialkyl ethers having at least 8 carbon atoms; liquid alkyl ketones having at least 9 carbon atoms; alkyl or aralkyl benzoates such as benzyl benzoate; alkylated naphthalenes; and partially hydrogenated terphenyls. Preferred solvents include ethyldiphenylmethane and 2,2,4-trimethyl-1,3-pentanediol di-i-butyrate. These solvents, all of which are substantially odorless, can be used alone or in combination. They can also be used with a diluent to reduce costs. Of course, the diluent must not be chemically reactive with either the solvent or any other chromogenic material, and must be at least partially miscible with the solvent to give only one phase. The diluent is used in an amount sufficient to achieve a cost advantage without impairing the solubility of the chromogenic material.

Diluents are already known in the art and a preferred example of this is Magnaflux oil, which is a mixture of saturated aliphatic hydrocarbon oils with a distillation temperature of 160 - 2900 ° C.

The amount of the chromogenic material according to the invention which should be used in the chromogenic solution will, of course, depend on particular desires, but usually a useful amount should be 0.6 - 3% by weight, i.e. parts by weight of chromogenic material per 100 parts by weight of solvent.

Microencapsulation of the chromogenic solution can be performed by methods known in the art, for example, by using gelatin as described in U.S. Pat. Nos. 800,847 and 3,041,289, using a urea formaldehyde resin described in U.S. Pat. No. 4,001,140, 4,087,376. and 4,089,802, and using various melamine formaldehyde resins described in U.S. Pat. No. 4,100,103.

Dye developers suitable for use with the chromogenic material of the invention are known in the art and include acid clays and oil-soluble metal salts of phenol formaldehyde and novolak resins of the type described in U.S. Pat. Nos. 67,693,935, 3,732,120 and 3,737,410. A preferred example of a suitable resin is a zinc-modified, oil-soluble phenol-formaldehyde resin, such as the zinc salt of a p-octylphenol-formaldehyde resin or the zinc salt of a p-phenylphenol-formaldehyde resin.

For a reverse transfer system, the chromogenic material of the invention is not microencapsulated as a chromogenic solution but is adsorbed on a water-insoluble, substantially chemically neutral pigment as described in GB, A, 1 337 924. The color developer which may be a resin color developer such as referred to above, however, is microencapsulated as a solution. Suitable solvents and encapsulation procedures include those referred to above.

The present invention further provides pressure sensitive recording materials which, as a component of the color formation system, contain chromogenic materials as defined above.

Coating formulations and methods for making pressure sensitive recording materials are well known in the art, for example GB, A, 1,337,924 and in U.S. Pat. Nos. 3,627,581, 3,775,424 and 3,853,869.

The invention will now be described with reference to a number of examples, in which all parts refer to parts by weight.

Example 1 Preparation of chromogenic material.

Quinolic anhydride (0.2l mol) and 1-ethyl-2-methylindole (0.33 mol) were mixed in a reaction flask at 65 DEG-700 DEG C. for 3 hours. The reaction mixture was then cooled and washed with 7910525 = 0 benzene or chlorobenzene to give 1-ethyl-2-methylindol-3-yl-3-carboxypyridin-2-yl-ketone and its isomer (0.19 mol). in ketone and its isomer (together 58.0 g; 0.188 mol) was stirred for 2 hours at 60 DEG-650 DEG C. with N, N-diethyl-m-phenetidine (35.3 g; 0.188 mol) and acetic anhydride (250 ml). ). The reaction mixture was poured into water (500 ml) and the acetic anhydride was hydrolyzed by slowly adding a 29% ammonium hydroxide (450 ml). After stirring for 2 hours, the resulting solid was filtered and washed with water, 40% methanol / water (200 ml) and petroleum ether (b.p. 60 DEG-110 DEG C.; 50 ml). The solid was then dried to constant weight in an oven at 750 ° C to give a mixture of (931 of 7- (1-ethyl-2-methylindol-3-yl) -7- (4-diethylamino-2-ethoxy) phenyl) -5,7-dihydrofuro (3,4-b) pyridin-5-one and 5- (1-ethyl-2-methyl-indol-3-yl) -5- (4-diethylamino-2-ethoxyphenyl) 5,7-dihydrofuro (3,4-b) pyridin-7-one (80.5 g, 90%, m.p. about 134 DEG-137 DEG).

Example gel 2 Preparation, of chromogenic material.

A mixture of (1-ethyl-2-methylindol-3-yl) (3-carboxypyridin-2-yl) ketone and its isomer (together 3.62 g; 0.011 mol) and N, N-diethyl-m -phenetidine (2.26 g; 0.011 mol) was stirred and heated for four hours at 600 DEG C. together with acetic anhydride (17 ml). The reaction mixture was poured into water (150 ml) containing sodium hydroxide (18.4 g).

The hot reaction mixture (50-60 ° C) was stirred vigorously for 1 hour and then filtered. The product obtained was washed several times with water, 30% methanol-water (10 ml) and finally with petroleum ether (b.p. 60 DEG-110 DEG C.). A mixture (20: 1) of pyridin-5-one compound and pyridin-7-one compound (5.66 g; melting point 148 - ISOOC2) - Example 2 Preparation of chromogenic material was obtained.

A mixture of 2'-carboxypyrid-3'-yl- (4-diethylamino-2-ethoxyphenyl) -ketone (3.75 g; 0.01096 mol), 1-ethyl-2-methyl-7910525-indole (1 74 g; 0.0106 mol) and acetic anhydride (35 ml) were heated for 5 hours at 750 DEG C. The reaction mixture was dropped into water (250 ml) containing sodium hydroxide (38.8 g). After stirring for several hours, the product was filtered. It was washed several times with water and finally with petroleum ether. The desired chromogenic material was obtained (3.37 g; 65%) in which the presence of only a very small amount of pyridin-7-one compound could be detected.

The reaction was carried out in a similar manner using mixed keto acid isomers, but then the resulting product contained more of pyridin-7-one compound.

Example 4 Preparation of chromogenic solutions.

A number of chromogenic solutions were prepared by mixing the following ingredients in the parts given below: 7910525-0 I0 Table 1 1 2 3 4 5 6 7 pyridyl blue - 1.2 1.8 2.4 - 1.2 1.2 CVL 3.4 2.8 2.2 1.6 3.4 2.8 2.8 indolyl red 1.1 1.2 1.2 1.2 l, l 1.2 1.2 N-loz 1,1 '- - - 1.1 0.6 - alkylate 214 * 130.0 130.0 130.0 130.0 130.0 130.0 200.0 ethyltiphenylmethane 70.0 70.0 70.0 70.0 70.0 70 , 0 - 8 9 10 ll, 12 13 pyridyl blue ~ - 2.0 2.0 - 2.0 CVL 3.4 3.4 2.0 2.0 3.4 3.4 2.0 indolyl red 1.1 1.2 1 1,2 1,2,1 1,2 N-102 1,1 1,2 - - 1,1 - other chromogenic materials - - - 1,0 (a) - 1,0 (b) alkylate 215 126,4 130.0 200.0 200.0 130.0 180.0 4 Ethyldiphenylmethane 68.0 70.0 - - 70.0 - other additives - - - - - 20.0 (c) Clo ~ Cl5 alkylbenzene (a) 3,1fbis (diethylamino) -10-benzoylbenzoxazine (b) BLMB (c) methyl myristate Example gel Preparation of microencapsulated chromogenic solutions.

Each of the chromogenic solutions 1 to 13 was microencapsulated according to the procedure of US, A, 4 001 140. Briefly, the procedure was as follows: 180 parts of chromogenic solution were emulsified in a mixture of 35 parts of 10% EMA 31 (ethylene maleic anhydride copolymer having a molecular weight in the range of 75,000 - 7910525-oll 90,000, marketed by Monsanto Chemical Co.) in water, 32 parts of 20% EMA 1103 (ethylene maleic anhydride copolymer having a molecular weight in the range 5000 - 7000 marketed by Monsanto Chemical Company) in water, 133 parts water, 10 parts urea and 1 part resorcinol, the pH was adjusted to 3.5. After emulsification, 29 parts of 37% formaldehyde were added and the mixture was placed in a 55 ° C water bath with stirring. After 2 hours, the temperature in the water bath was allowed to equilibrate with the ambient temperature with continued stirring.

Example gel 6 Preparation of microcapsule coating preparations.

Each of the microcapsule kits 1 - 13 was prepared into a coating formulation using the materials and parts listed below: Weight parts, Weight parts, wet dry capsule set 80 40 wheat starch granules 10 10 x Penford 230, 10% _ 40 4 water 100 x Preferred corn starch binder by Penick and Ford Ltd.

Example gel 7 Preparation of CB recording material.

Each of the coating formulations 1 - 13 was dispersed, applied to a paper base and pulled out with a wire-wound coating rod No. 12 and the coatings were allowed to dry in hot air.

Example 8 Comparative CB declination test.

Each CB recording material from 1 to 13 was subjected to the Typewriter Intensity Test (TI) in which a standard pattern is written on an impact kit comprising a CF and a CB sheet, (the CF sheet in the present sample is coated with a zinc modified phenolic resin which described in U.S., A, 3,732,120 and 3,737,410). A colored print corresponding to the pattern is thus produced on the CF sheet and the intensity of the print is determined by means of an opacimeter.

The intensity is a measure of the color development and is the ratio between the reflectance of the imprint and of the surface without imprint (I / ID) expressed as a percentage; A high value indicates low color development and a low value indicates high color development.

Typewriter intensity tests were performed before exposing the CB sheet to radiation from fluorescent light and after 1 and 2 hours of exposure to the CB sheet with such radiation, respectively. In all these cases, the intensity measurements were made 20 minutes after the impression.

The device for the fluorescent light samples consisted of a light box containing a battery of 18 fluorescent daylight lamps (53.3 cm long, 13 watts nominal power) vertically mounted on central supports of 2.5 cm, the CB sheets were placed 2, 5 - 3.8 cm from the lamps.

The results obtained for the thirteen CB recording materials are shown below: 7910525 ~ 0 13 Original Change in TI after light CB recording- TI exposure of CB coating material No. 1 h 2 h Exposure Exposure l 44 -20 -33 2 48 - 12 -24 3 41 -12 -20 4 47 -12 -19 _ 5 35 -15 '-3l 6 44 -14 -24_ 7 46 -14 -24 8 36 -13 -34 9 35 -18 -32 10 43 - 8 -13 ll 43 '-8 -14 12 39. -13 -34 13 39 -5 -ll The degree of CB declination that is acceptable naturally depends on the duration of light exposure on the CB sheet.

For an exposure of 2 hours, a loss of more than about 26 units is unacceptably high. The recording materials 2, 3, 4, 6, 7, 10, 11 and 13 which contained pyridyl blue thus showed a sufficiently low degree of CB declination to be acceptable. Registration materials 1, 5, 8, 9 and 12 which were control samples without any pyridyl blue at all all showed too high a degree of CB declination to be approved.

Example 9 Preparation of chromogenic solutions.

An additional number of chromogenic solutions were prepared by mixing the following ingredients into the indicated parts: 7910525-0 14 14 '15 16 -pyridyl blue 91.8 91.8 CVL 1 21.6 21.6 91.8 indolyl red 27.0 _27.0 14 , 8 N-102 16.2 16.2 _ 29.7 2,3,4-trimethyl-1,3-pentanediol diisobutyrate ~ 3495.6 - 3509, 1 'Magnaflux oil 747.8 3146.0 l754.6 aibutyphthalate - 2o97.4 - Example 10 Preparation of microencapsulated chromogenic solutions.

Each of the chromogenic solutions 14-16 was microencapsulated according to the procedure of US, A, 4,100,103. The specific procedure was as follows: In 5400 parts of a chromogenic solution was emulsified in a mixture of 1000 parts of 10% EMA 31 in water and 5600 parts of water, the pH was adjusted to 3.7. The pH of the emulsion was then adjusted to 4.0. A mixture of 1000 parts of 10% EMA 1103 in water was adjusted to pH 4.0, 1000 parts of water and 1000 parts of Resimen 714 were added to the emulsion. The resulting mixture was heated to 550 ° C for 2 hours. After this time, the temperature of the mixture was allowed to equilibrate with the ambient temperature with continued stirring.

Exemgel ll Preparation of microcapsule coating preparations.

Each of the microcapsule batches 14-16 was prepared into a coating formulation using the materials and parts set forth below: parts by weight, dry capsule batch 70,40 wheat starch granules 21,10 etherified corn starch binder 4,25 polyvinyl alcohol binder 4,25 7910525-0 water was added to prepare a 17.4% solids formulation for coating.

Example 12 Preparation of CB recording material.

Each of the coating formulations 14 - 16 was dispersed and spread on a paper base using an experimental scale air knife coater and then dried.

Example 13 Comparative CB declination test.

CB recording materials 14 - 16 were subjected to the same test in the same manner as described in Example 8.

The results obtained are given below: CB registration- Original Change in TI after light material no. TI exposure of CB coating 1 h 2 h Exposure Exposure 14 46 -2 -9 15, 47 -1 -3 16 53 -17 -30 Using of the approval guidelines shown in Example 8, the recording materials 14 and 15 containing pyridyl blue show excellent resistance to CB declination, while the control sample without pyridyl blue, recording material 16, gave unsatisfactory results.

Example 14 Preparation of CF recording material with pyridyl blue for use in a reverse transmission system. (a) Pyridyl blue (1 g) was dissolved in acetone (150 ml). Precipitated calcium carbonate (70 g), Cabolite 100 urea-formaldehyde resin pigment (20 g, US, A, 3,988,522) and zinc oxide (10 g; Green Seal 8 from New Jersey Zinc Co., USA) were then mixed into the solution and the resulting dispersion was allowed to dry in a hood. (b) The product from step (a) was then processed into a coating formulation having the following ingredients and amounts: 7910525-Û 16 parts by weight dry weight% wet dry step (a) test week 84 84 5 83.4 Penford Gum 260 100 10 9.9 (modified maize starch) Dow Latex 620 12 6 A 6.0 (carboxylated styrene-butadiene latex) Tamol 731 3 0.75 0.7 (25% solution of the sodium salt of a polymeric carboxylic acid, marketed by Rohm & Haas) water 250 449 100.75 100 (c) The resulting preparation was coated on (1.54 kg kg) of glued paper with a No. 12 Mayer bar and then dried. The weight of the dry coating was about 2.04 kg per bundle of 500 sheets, measuring 63.5 x 96.5 cm.

Exemgel 15 Preparation of CF recording material with CVL for use in a reverse transmission system.

The procedures of steps (a), (b) and (c) of Example 14 were repeated except that pyridyl blue was replaced with crystal violet lactone. Example 16 Alternative preparation of CF recording material with pyridyl blue. * g (a) Pyridyl blue (300 g), calcium carbonate (600 g), Penford Gum 230 with 10% solids (modified grain starch; 300 g) Tamol 731 (30 g) with 25% solids and water (1200 g) were ground in a grinder for 45 minutes along with a few drops of octanol to reduce foaming. (b) The product from step (a) was prepared into a coating formulation having the following ingredients and amounts: 7910525-0 17 parts by weight dry weight% wet dry product from step (a) 6.3 2.0 3.0 calcium carbonate 43.4 43 , 4 65.8 Ansilexlera (US, A 3,586,523) 9.9 9.9 15.0 Penford Gum 230 66.0 6.6 10.0 Dow Latex 620 8.0 4.0 6.0 Calgon T 0 , 0.1 0.1 0.1 (molten sodium-zinc-phosphate-glass powder composition) water 110.3 244.0 66.0 99.9 Solids in the coating 27% Viscosity 58 cp (c) The resulting preparation was coated on 15, 42 kg of sheet paper base with an air knife and then dried. The weight of the dry coating was about 2.04 kg per bundle of 500 sheets and measured 63.5 x 96.5 cm.

Example 17 Alternative preparation of CF recording sheets for registration with CVL.

The procedures of step (a), (b1 and (c) of Example 16 were repeated except that pyridyl blue was exchanged for crystal violet lactone and 300 g of calcium carbonate in step (a) were exchanged for 300 g of zinc cresinate.

The solids of the coating and the viscosity of the preparation were 27% and 57 cp, respectively.

Example 18 Preparation of CB and CFB sheets with acidic resin. (a) p-Phenylphenol resin (1200 g, PPP resin) was dissolved in dibenzyl ether (3200 g) and Magnaflux oil (1600 g) with heating and stirring. EMA 31 (ethylene-maleic anhydride copolymer having a molecular weight in the range of 75,000 - 90,000; 200 g) was dissolved in deionized water (1800 g) while heating and stirring. The resulting EMA solution was diluted with deionized 79% water (6000 g) and the pH was adjusted to 4.0 with 20% sodium hydroxide solution. The PPP resin oil solution was then emulsified in the EMA solution with a Cowles dissolver at 250 ° C.

The emulsification was allowed to continue until an average oil droplet size of about 2 Jun was reached with a total droplet size distribution lying in the range of about 0.5 - 15) nn. The resulting emulsion was then transferred to a water bath maintained at 550 DEG C. and, with rapid stirring, 80% Resloom 714 (etherified methylolmelamine; 1000 g) diluted with deionized water (1000 g) was added. The resulting mixture was kept at 55 ° C for 2 hours with constant stirring to effect capsule formation. After 2 hours, the temperature slowly adjusted to equilibrium with the room temperature. Stirring was allowed to continue for another 16 hours. (b) The microencapsulated solvent solution of PPP was then prepared into a coating formulation having the following ingredients_and amounts: parts by weight dry weight% wet dry in capsules from step (a) 26.60 12.50 71.4 stilt starch 3.20 3.12 17.9 Stayco S starch 6.30 0.63 '3.6 Dow Latex 638 2.50 1.25 7.1 (carboxylated styrene-butadiene latex) water - 26.40 65.00 17.50 l00, 0 Solid constituents in the coating 27% Viscosity 68 cp (c) The resulting preparation was spread on a 15.42 kg sheet of paperboard with an air knife and then dried. The dry coating weight was about 1.7 kg per bundle of 500 sheets and measured 63.5 x 96.5 cm. In addition, the preparation was coated on the back of the recording sheet 2 recorded in accordance with the procedure of Examples 16 and 17 for the purpose of preparing CFB sheets. 7910525-0 l9 Example 19 Preparation of alternative CB sheet with acid resin. (a) An oil solution of p-octylphenol resin (1400 g; POP in dibenzyl ether (3200 g) and Magnaflux oil (1600 g) was prepared using sufficient heat and stirring to effect dissolution. The oil solution was then microencapsulated using the procedure described for step (a) in Example 18. (b) and (c) The procedures of steps (b) and (c) in Example 18 were repeated except that 27.3 wet parts by weight (instead of 26.6) of The POP capsules from step (a) were used and the formulation was used only to make CB sheets.

Example 20 Comparison between recording sheets for registration based on pyridyl sheet and CVL, respectively.

Recording materials based on pyridyl blue and crystal violet lactone were subjected to the typewriter intensity test, in which a standard pattern was printed on a breakthrough set consisting of a CF and a CB sheet and possibly an intermediate CFB sheet. A colored image print corresponding to the pattern is then generated on the CF sheet or on the CF side of a CFB sheet and the intensity of the image is determined using an opacimeter.

The intensity is a measure of the color development and is the ratio between the reflectance of the imprint and of the surface without image expressed in percent. A high value indicates small color development and a low value indicates high color development.

For the comparison between recording material with pyridyl blue and CVL, the following intensities were determined: A - The initial intensity, i.e. the intensity of an image 24 hours after the initial development, B - The intensity of an image after it has been exposed: (i) for fluorescent light, (ii) for natural sunshine, (iii) for ambient conditions or (iv) in an oven, C - The intensity of an image generated on a sheet previously exposed: (i) for fluorescent light, (ii) for natural sunlight, (iii) j for ambient conditions, or ( iv) in an oven.

The device for fluorescent light samples consisted of a light box containing a 53.3 cm long row of 18 fluorescent daylight lamps of 13 watts of power vertically mounted on 1-inch central support. The sheets with or without the image were placed 2.5 - 3.8 cm from the lamps for 48 hours. Image prints were made with an IBM Executive typewriter using a "§§É" type.

The sheets with or without the image imprint were exposed to natural sunlight by being placed for 48 hours in a window facing south. Image prints were made with an IBM Memory typewriter using an "X" type.

The sheets with or without image were exposed to the environment by being hung on a laboratory wall for 7 and 9 weeks during which time the sheets were exposed to air, natural and fluorescent room light, air temperature and humidity. Imaging was performed with an IBM Selectric typewriter_Using a fixed block type¿ Exposure of the sheets in an oven was performed for 3 weeks at a temperature of 60 ° C. Imaging was performed with an IBM Executive typewriter using a “§šÉ” type.

The results obtained were the following sheets of acid resin recording sheet AB (i) C (i) Example 18-CB Example 16-CF 38 48 55 Example 18-CB Example 17-CF 51 74 78 Example 18 and Example 18 and Example 16-CFB Example 16-CFB 49 51 56 Example 18 and Example 18 and Example 17-CFB Example 17-CFB 52 68 75 21 sheets of acid resin registration sheet Example 18-CB Example 14-CF Example 19-CB Example 14-CF Example 18-CB Example 15 ~ CF 'Example 19-CB Example 15-CF Example 18-CB Example 16-CF Example 19-CB Example 16-CF Example 18-CB Example 17-CF Example 19-CB Example 17-CF Example 18-CB Example 16-CF Example 18-CB Example 17-CF Example 18 and Example 18 and Example 16-CFB Example 16-CFB Example 18 and Example 18 and Example 17-CFB Example 17-CFB Example 18-CB Example 16-CF Example 18 CB Example 17-CF Example 18 and Example 18 and Example 16-CFB Example 16 ~ CFB Example 18 and Example 18 and Example 17 ~ CFB Example 17-CFB A 40 52 40 56 A 33 44 34 57 'ê 32 34 33 35 40 48 48 51 79'í0525-0 B (ii) 41 53 52 74 min ) 38 56 45 73 B (iii1 42 54 42 55 B (iv) 49 49 45 51 C (ii) 65 75 88 96 cuii) 7 weeks 48 54 72 89 c (iii) 9 weeks 76 45 76 C (iv) 52 From the foregoing examples and in particular Examples 8, 13 and 20 it will be appreciated that the chromogenic material of the invention is a significant improvement over crystal lactone. In particular, an image generated by the material has better color fastness and the material itself is much less sensitive to violet light. Therefore, it retains its reactivity longer. In addition, in a reverse transmission system, recording material containing pyridyl blue can produce an image of greater intensity than recording material containing crystal violet lactone.

Claims (15)

7910525-0 Patent claims 1. Chromogenic material, characterized in that the dominant substance consists of a compound of the formula ÉZHS DEZHS N c l | C 2 H 5 N 9 N 2 O n = n m 3 fz fl s designated 7- (1-ethyl-2-methylindol-3-yl) -7- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro (3, 4-b) pyridin-5-one, optionally in admixture with the isomeric compound 5- (1-ethyl-2-methylindol-3-yl) -5- (4-diethylamino-2-ethoxyphenyl) -5.7 -dihydro-furo (3,4-b) pyridin-7-one of the formula N in Uh Chromogenic material according to claim 1, characterized in that it consists of at least 90% pyridin-5-one isomer. Chromogenic material according to claim 2, characterized in that it consists of at least 95% pyridin-5-one isomer. Process for the preparation of a chromogenic material according to Claim 1, characterized in that a keto acid of the formula 79'š0525 ~ 0 24 Ü \\ [/ Å NI \ CÜUH 2 / and / or its 2-carboxy-pyride is reacted -3-yl ismer with a compound of formula B - H wherein one of A and B is 4-diethylamino-2-ethoxyphenyl and the other is 1-ethyl-2-methylindol-3-yl in the presence of a dehydrating agent. Process according to Claim 4, characterized in that the dehydrating agent is an acid anhydride. 6. A process according to claim 5, characterized in that the acid anhydride is acetic anhydride. Process according to one of Claims 4 to 6, characterized in that the reaction is carried out at a temperature of 65-75 ° C. Process according to any one of claims 4-7, characterized in that A is 1-ethyl-2-methylindol-3-yl and that the keto acid is prepared by reacting quinolinic anhydride with 1-ethyl- 2-methylindole. ¿ 9. A process according to any one of claims 4-8, characterized in that A is 4-diethylamino-2-ethoxyphenyl and that the keto acid is prepared by reacting quinolinic anhydride with N, N-diethyl-m-phenetidine. 10. A process for the preparation of a chromogenic material according to claims 1-3, characterized in that quinolinic anhydride, 1-ethyl-2-methylindole and N, N-diethyl-m-phenetidine are reacted in the presence of a dehydrating agent. Pressure-sensitive recording material, characterized in that it contains in the color formation system the chromogenic material according to any one of claims 1-3. Use of the compound 7- (1-ethyl-2-methylindol-3-yl) -7- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro (3,4-b) pyridine-5- and optionally 5- (1-ethyl-2-methylindol-3-yl) -5- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro (3,4-b) pyridin-7-one as chromogenic material and as a means of preventing a decrease in the color-forming reactivity of crystal violet lactone or other chromogenic materials present therein. Use of the compound 7- (1-ethyl-2-methylindol-3-yl) -7- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro (3,4-b) pyridine-5- and optionally 5- (1-ethyl-2-methylindol-3-yl) -5- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro (3,4-b) pyridin-7-one such as chromogenic material and as a means of preventing a decrease in the color fastness of crystal violet lactone or other chromogenic material present therein. 14. A process for improving the ability of recording materials to resist reduction in color formation reactivity, characterized in that the compound 7- (1-ethyl-2-) is added to the color formation system together with crystal violet lactone and / or one or more other chromogenic materials. methylindol-3-yl) -7- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro (3,4-b) pyridin-5-one and optionally 5- (1-ethyl-2-methylindol- 3-yl) -5- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro (3,4-b) pyridin-7-one. Process for improving the ability of recording materials to withstand a decrease in color fastness, characterized in that the compound 7- (1-ethyl) is added to the color formation system together with crystal violet lactone and / or one or more other chromogenic materials. -2-methylindol-3-yl) -7- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro (3,4-b) pyridin-5-one and optionally 5- (1-ethyl-2 -methylindol-3-yl) -5- (4-diethylamino-2-ethoxyphenyl) -5,7-dihydrofuro (3,4-b) pyridin-7-one. 7910525-0 Abstract Chromogenic material for use in pressure sensitive recording materials consisting of either 7- (1-ethyl-2-methylindol-3-yl) -7- (4-diethylamino-2-ethoxyphenyl) -5,7- dihydrofuro (3,4-b) pyridin-5-one, optionally in admixture with 5- (1-ethyl-2-methylindol-3-yl) -5- - (4-diethylamino-2-ethoxyphenyl) -5, 7-dihydrofuro (3,4-b) pyridin-7-one. The invention also relates to a process for the preparation of the chromogenic material in which a keto acid of the formula nN / A NI \ CÛÛH / is reacted with a compound of the formula in BH where one of A and B is 4-diethylamino-2-ethoxyphenyl and the other is 1-ethyl-2-methylindole-Bjyl in the presence of a dehydrating agent. '