JPS5827117B2 - record sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording sheet used in pressure-sensitive copying sets and the like.

A color forming system used in a pressure-sensitive recording material comprises a substantially colorless chromogen composition, a coloring agent that reacts with the chromogen composition to form a color, and a solvent in which the coloring reaction is carried out. Usually have.

The reactive components of the color forming system are sequestered until use.

This exfoliation is usually accomplished by microencapsulating a solvent solution of either of the components.

In use, the microencapsulation is broken by applying pressure, resulting in release of the solvent solution.

This then brings the two color-forming components into reactive contact and forms a colored image that corresponds precisely to the shape of the applied pressure.

In this way, pressure-sensitive recording materials are used when copying is performed without using carbon paper.

The reactive color forming component and the solvent can be placed on the recording material by many means.

One aspect is called a metastasis recording system, in which the first
A microencapsulated solution of a color-forming component is applied to one side of one sheet (CB sheet), and a second color-forming component is applied to one side of another sheet (CF sheet).

These two pairs of sheets are superimposed as a copy set so that their coatings are in contact.

Thus, when pressure is applied to the uncoated side of the CB sheet, the solution is released and transferred to the CF sheet undergoing recording to carry out the color forming reaction.

A copy set can additionally have one or more intermediate sheets (CFB sheets).

The CF'B sheet has a microcafuslating solution on one side and a coating of a second color-forming component on the other side.

In this way, more copies can be made as long as these sheets are properly positioned with respect to the solution being transferred to the CF or CFB sheet receiving the record.

Another embodiment is referred to as a self-contained system in which microencapsulated solutions of first and second color-forming components are mixed and applied to the same side of a sheet.

When pressure is applied to the recording sheet, the solution is released and reacts with the second color-forming component to develop an image on the sheet that corresponds to the pattern of applied pressure.

In both transfer and self-contained systems, the color-forming component microencapsulated in solution is usually a chromogenic material.

This is because chromogen materials are more susceptible to atmospheric deterioration than color formers.

However, recently in British Patent No. 1337927,
The recording sheet, i.e. the sheet on whose surface the color-forming reaction takes place, is chemically adsorbed to its surface a substantially colorless color-based chromogenic material capable of producing color when reacted with a color former. A technique for providing a neutral pigment coating is described.

By adsorption onto the pigment, the chromogenic material is stabilized against atmospheric degradation, and this sheet can be used in inversion systems, i.e. systems where the color former, rather than the chromogenic material, is microencapsulated as a solvent solution. It becomes possible.

Although others have been mentioned, British Patent No.
The only chromogen material actually used in the recording sheet of No. 337924 was crystal violet lactone (3.3
-bis-(P-dimethylaminophenyl)-6-dimethylaminophthalide).

Although the use of this chromogenic material makes the sheet highly suitable for use in inversion systems, it still has many properties that need improvement.

Such properties are the density of the colored image (image density), the ability of the image to resist fading (fade resistance), and the ability of the adsorbed chromogenic material to resist atmospheric degradation.

It is an object of the present invention to provide a recording sheet for use in inversion systems and having improved properties as described above.

The present invention provides a recording sheet having on one side a coating of a water-insoluble, substantially chemically neutral pigment that has adsorbed pyridyl flue.

The use of pyridyl blue improves the resistance to atmospheric degradation, ability to form images of improved density, and fade resistance of the recording sheets of the present invention, while improving the resistance of recording sheets of the present invention to all types of recording sheets conveniently used in reversal systems. It has advantages.

Pyridyl blue itself is a novel chromogenic material with the following formula: 5-(l-ethyl-2-methylindol-3yl)-
5-(4-diethylamino-2-ethoxyphenyl)
-5,7-cyhydrofuro(3,4-b)pyridine-7-
on and/or 7-(1-ethyl-2-methylindol-3yl)-
7-(4-diethylamino-2-ethoxyphenyl)-
5,7-Sihydrofuro(3,4b)pyridin-5-one Both of these two isomers can be used in chromogen compositions, but the pyridin-5-one isomer is more effective. .

However, the methods that can be used to synthesize pyridyl blue (see e.g. British Patent No. 1,367,567 and US Pat. No. 3,775,424) usually produce mixtures of isomers, and conventional techniques (e.g. chromatography)
Separating a single isomer from the mixture is difficult, time consuming, and industrially expensive.

It is therefore more advantageous to use mixtures and to select conditions for their preparation which favorably form the pyridi/-5-one isomer.

In this way, a mixture is obtained for use in recording sheets, in which the more effective pyridin-5-one isomer is present in higher amounts.

When reacted with a color former, pyridyl flue produces a blue color.

Examples of water-insoluble substantially chemically neutral pigments include:
These are calcium carbonate, zinc oxide, barium sulfate, titanium dioxide, barium carbonate, magnesium carbonate, calcium oxide, magnesium titanate and zinc sulfide.

For transfer systems, this recording sheet may be e.g.
It can be used as a sheet, or it can be used as a CFB sheet by applying a pressure-destructible microencapsulated solution of a color former on the other side.

For self-contained systems, a collapsible microencapsulated solution of color former is applied to the same side of the sheet, preferably incorporated within the coating.

The recording sheet of the invention has a base of plastic, preferably paper.

The present invention also provides a method for making a recording sheet, which comprises adsorbing pyridyl blue onto a water-insoluble, substantially chemically neutral pigment and then applying a component containing said pigment onto the sheet. do.

The method of adsorption of the pyridyl flue onto the pigment is not critical to the invention.

The only requirement is that the pyridyl blue be adsorbed to the pigment in a colorless state.

Possible means include passing a solution of pyridyl flue through a pigment bed as in chromatographic methods;
and involves precipitating the pyridyl blue from solution in the presence of the pigment by any of a number of precipitation techniques known in the chemical arts.

Examples of such techniques include dilution of pyridyl blue solutions with non-solvents and miscible solutions for pyridyl blue, chemical neutralization of acidic aqueous solutions of pyridyl blue, cooling of hot solutions of pyridyl blue, and This includes evaporation of a solvent from a solution.

Any of these methods results in the formation of water-insoluble, substantially chemically neutral pigments that have adsorbed pyridyl blue, and such pigments represent one embodiment of the present invention.

The composition having a pyridyl blue adsorbed pigment representing another aspect of the invention is applied to the sheet surface by any of the known application methods used in pressure sensitive recording material technology.

For example, Mayer rod or air knife coating methods can be employed.

The composition is usually liquid and contains suitable binders such as styrene butadiene latex and/or starch.

Additionally, the composition may contain small amounts of known paper coating ingredients, such as wetting agents and antifoaming agents.

Coating compositions and application methods that can be used in the present invention are described in U.S. Pat.

However, when applying the technology of the above patent to the present invention, when using the recording sheet in a transfer system, a composition containing a pigment that has adsorbed pyridyl blue is
It is necessary to limit the application to the CF side of the F sheet or CFB sheet.

A microencapsulated solvent solution of color former is applied to the CB side of the CB sheet or CFB sheet.

As stated above, this embodiment is the opposite of that commonly known in pressure-sensitive recording material technology.

If the recording sheet is used in a self-contained system containing two color-forming components in the coating, the coating composition must also contain a microencapsulated solvent solution of the color former.

The coloring agent may be any one known for use in pressure-sensitive recording materials, but it goes without saying that it must be dissolved in a solvent and capable of developing a pyridyl blue color.

Suitable examples of such color formers include acidic novolac resins, such as P-phenylphenol-formaldehyde resins or P-octylphenol-formaldehyde resins.

As the solvent for the acidic resin coloring agent, any solvent known in the art of pressure-sensitive recording materials can be used.

Preferred examples include dibenzyl ether; Magnaflux oil (370
Benzyl benzoate; 2,2,4-trimethyl-1,3-bentanediol dimybutyrate (T
XIB; U.S. Pat. No. 4,027,065); dibutyl phthalate: 1,24-trimethylbenzene; ethyl diphenylmethane (U.S. Pat. No. 3,996,405); C0l~
C12 alkylbenzene; and i-propylbiphenyl (US Pat. No. 3,627,581).

However, the most preferred is a mixed solvent of dibenzyl ether and Magnaflux oil.

Microcapsules of solvent solutions of acidic resin color formers can be prepared from gelatin as described in U.S. Pat.
From formaldehyde polymers, U.S. Pat. No. 375,519
0 (from resorcinol-formaldehyde-filled polyvinyl alcohol wall capsules) and from various melamine-formaldehyde polymers as described in U.S. Pat. No. 4,100,103.

Further, the present invention provides a pressure sensitive copying set including a recording sheet as described above.

The present invention will be explained below with reference to a number of examples, but these are not intended to limit the scope of the invention.

Example 1 Preparation of Pyridiri Blue Quinolinic anhydride (0.21 mol) and 1-ethyl-2-methylindole (0.33 mol) were mixed in a reaction flask at 65-70°C for 3 hours.

The reaction mixture was cooled and washed with benzene (or chlorobenzene) to form (1-ethyl 2-methylindol-3-yl)(3-carboxypyridin-2-yl).
A ketone and its isomer (0.10 mol) were obtained.

(1-ethyl-2-methylindol-3-yl) (3
-Carboxypyridin-2-yl) ketone and its isomer (both 58.09P; 0.188 mol) were added to N-N-
Diethyl-m-phenetidine (35,3f; 0.1
88 mol) and acetic anhydride (250 TrLl) and 60
Stirred at ~65°C for 2 hours.

The reaction mixture was poured into water (500 mO) and the acetic anhydride was hydrolyzed by slowly adding 29% ammonium hydroxide (450 mO).

After stirring for 2 hours, the resulting solid was filtered and water, 40
% methanol/water (200 m0 and petroleum ether (b
, p, 60-11O<0>C: Washed at 50mO.

The solid was then dried in an oven at 75°C to constant weight and 7-(1-ethyl-2-methylindol-3-yl)-7-(4diethylamino-2-
ethoxyphenyl)-5,7-cyhydrofuro (3,4.
-b) Pyridin-5one and 5-(1-ethyl-2-methylindol-3-yl)-5-(4-diethylamino-2-ethoxyphenyl)-5,7-cyhydrofuro(
3.4-b) Pyridin-7-one (80.5 g, 90%
, m, p, ~134-137 °C) (9:1, respectively) was obtained.

Example 2 Preparation of Pyridyl Blue CF Recording Sheet (a) Pyridyl Blue (11) was mixed with acetone (150
Dissolved in m0.

Precipitated calcium carbonate (7ou), capolite (Cabo
lite) 100 urea-ho/L/Maldehyde pigment (20?; U.S. Patent No. 3,988,352) and zinc oxide (10 g; Green 5eal manufactured by New Jersey Cinta Company, USA)
were mixed in the above solution and the resulting dispersion was dried in a hood.

☆☆(b) Next, the product of stage 1ia) was made into a coating composition using the following components and ratios.

(e) The resulting composition was applied to 34 pound sheet paper using a 12 Meyer rod and then dried.

Dry coating weight is 25 x 38 inches (63.5 x 96.
The weight was approximately 4.5 pounds (2.04 kg) per ream of 500 sheets (5c door).

Comparative Example I Preparation of CVL CF Recording Sheet The procedure of steps (aXb) and (C) of Example 2 was repeated except that pyridyl blue was replaced by crystal violet lactone.

: Example 3 Other preparation of pyridyl blue CF recording sheet (a) Pyridyl blue (300f?), calcium carbonate (600f?)
r), 10% solids Pen Photogum (Penford G
nm) 230 (modified cornstarch; 300f),
25% solid Tamol 731 (30f?)
and water (120 Or) were milled in a mill for 45 minutes with a few drops of Octatool to reduce foaming.

(b) A coating composition was then made from the product of step a) and the following ingredients and ratios.

(e) The resulting product was applied to a 34 pound (15,421V) base sheet paper using an air knife coater and then dried.

Dry paint weight is 25 x 38 inches (63,5 x 9
Each ream of 500 sheets (6.5 cm) weighed approximately 4.5 pounds (2.04 kg).

Comparative Example 2 Other Preparation of CVL CF Recording Sheet The procedure of Example 3 was repeated except that the pyridyl flue was replaced by crystal violet lactone and the calcium carbonate at 301' in stage (a) was replaced by 300P zinc resinate. Steps a), (b) and (e) were repeated.

The solid content of the paint and the viscosity of the composition are each 27%.
and 57 cps.

Preparation Example 1, Example 4 and Comparative Example 3 Preparation of acidic resin CB and CFB sheets (a) p −7x = /1/7 x Nord resin (
12001 PPP resin) to dibenzyl ether (320
0? ) and Magnaflux oil (1600 g) under heating and stirring.

EMA31☆r (ethylene-maleic anhydride copolymer with a molecular weight range of 75,000 to 90,000; 200P)
was dissolved in deionized water (1800f) with stirring and heating.

The resulting EMA solution was diluted with deionized water (6000P) and the pH was adjusted to 4.0 with 20% sodium hydroxide solution.

An oil solution of PPP resin was prepared using a Cowles dissolver (Cowl's dissolver).
ES]) EM at 25°C by 1ssolver)
Emulsified in solution A.

Emulsification was continued until an average oil droplet size of about 2 microns and a distribution of total oil droplet sizes ranging from about 0.5 to 15 microns were obtained.

The resulting emulsion was transferred to a water bath adjusted to 55°C and diluted with deionized water (10005') while stirring.
x-7-/1/methylolmelamine; 1001) was added.

The resulting mixture was kept at 55° C. for 2 hours under constant stirring to effect encapsulation.

After 2 hours, the temperature of the mixture gradually equilibrated with the ambient temperature.

Stirring was continued for an additional 16 hours. (b) A coating composition was obtained from a microencapsulated solvent solution of ppp with the following components and ratios.

(c) ■ The resulting composition was applied to a 34 pound (15,42 kg) base sheet paper using an air knife coater and then dried to prepare an acidic resin CB sheet (Preparation Example 1).

Dry paint weight is 25 x 38 inches (63,5 x 96
．． Each ream of 500 sheets of 5 cm2) weighed approximately 3.75 pounds (1.7 kg).

(2) A recording sheet prepared according to the procedure of Example 30 was used instead of the base sheet paper, and the composition was coated on the back side of the recording sheet in the same manner as described above, dried and coated with acidic resin C.
A BF sheet was prepared (Example 4).

(2) A recording sheet prepared according to the procedure of Comparative Example 20 was used instead of the base sheet paper, and the composition was coated on the back side of the recording sheet in the same manner as described above, and dried to coat the acidic resin C.
A BF sheet was prepared (Comparative Example 3).

Preparation Example 2 Preparation of Other Acidic Resin CB Sheets (a) Sufficient solution of p-octylphenol resin (1400P; POP) and Magnaflux oil (160(1)) in dibenzyl ether (3200g) Prepared with heat and stirring.

This oil solution was microencapsulated using the method described in Preparation Example 2, stage (a).

(b) and 'ff1c) P OP (a) except that 27.30 (instead of 26.60) parts by weight (wet temperature) of the stage capsule was used and the composition was used only for the preparation of the CB sheet. The procedure according to Preparation Example i gb) and C) was repeated.

Comparative Experimental Example Comparison of Pyridyl Flue and CVL Recording Sheets Pyridyl Flue and Crystal Violet Lactone recording sheets were subjected to a typewriter strength test.

In this test, a standard pattern is typed onto a copy set having CF and CB sheets and optionally an intermediate CFB sheet.

A colored print image corresponding to this pattern is formed on the CF side of the CF sheet or CFB sheet, and the density of the image is determined using an opacity meter.

This density is a measure of color development and is the ratio (I/Io) of the reflection of the image forming area to the reflection of the non-image forming area, expressed as a percentage.

A high value indicates a low degree of color development, and a low value indicates a high degree of color development.

The following concentrations were measured for comparison between Pyridyl Fluor and the CVL recording sheet.

A - Original density, i.e. the density of the printed image 24 hours after initial color development.

B - Density of the image after the following treatments.

(1) Fluorescent ray irradiation (11) Natural light irradiation (iii) Leaving in the atmosphere (IV) Leaving it in the oven C-Sheet that has been previously treated as follows.

The density of the image formed in

(i) Fluorescent light irradiation (11) Natural light irradiation (it) left in the atmosphere at 6 V) The apparatus for the oven kept fluorescence test was a 18 day light irradiation test set vertically on a 1 inch central support. It had a light source box with a bank of light lamps (21 inches long, 13 nominal lamp watts).

A sheet with or without an image is removed from the lamp from 1 to
4 at 1.5 inch (2.5-3.8 cm) intervals
It was placed for 8 hours.

Imaging was done on an IBM Executive typewriter using 4-bar crosshatch text.

Irradiation of the sheets with and without images by natural light was accomplished by placing them in a south-facing window for 48 hours.

Use the characters fl X I+ to select IBM memory (Mem
ory) Image formation was performed by a typewriter.

Atmospheric processing of the sheets with and without images was done by hanging the sheets on the walls of the laboratory for 7 and 9 weeks.

During that period, the sheet was exposed to air, natural light, room fluorescence, air temperature and humidity.

The image was formed using solid block letters and an IBM Select 5 electric typewriter.
It was done by

140 sheets left in the oven (60℃)
The test was carried out for 3 weeks at a temperature of

To form the image, use the 4-bar crosshatch character, IB
This was done on an M executive typewriter.

The results obtained are shown in the following table.

In addition, in the table, Preparation Example 1-CB, Preparation Example 2-CB, Example 2
-CF, Example 3-CF, Example 4CFB, Comparative Example 1-
CF, Comparative Example 2-CF, and Comparative Example 3-CFB are the CB sheet, CF sheet, or CF'B obtained in Preparation Example 1.2, Example 2.3.4, and Comparative Example 1.2.3, respectively.
It is a sheet.

From the above results, it was found that the recording sheet of the present invention was improved over the conventional recording sheet using the same concentration of crystal violet lactone.

In particular, it has been found that resistance to quality deterioration, including atmospheric deterioration, is improved and images with improved density and fade resistance can be formed.

Claims (1)

[Scope of Claims] 1. A recording sheet having on one surface a coating film comprising a water-insoluble, substantially chemically neutral pigment and a chromogen material represented by the following formula adsorbed to the pigment. 2. The recording sheet according to claim 1, wherein the pigment is calcium carbonate. 3. The recording sheet according to claim 1 or 2, wherein the other side of the sheet has a coating film of a microencapsulated color former solution that can be broken under pressure. 4. Claim 1, in which the coloring solution encapsulated in microcapsules that can be broken under pressure is applied to the same surface of the sheet.
Recording sheet as described in Section 2 or Section 2. 5. The recording sheet according to claim 3 or 4, wherein the coloring agent is an acidic novolac resin. 6. The recording sheet according to claim 5, wherein the resin is P-phenylphenol-formaldehyde resin or P-octylphenol-formaldehyde resin. 7. The recording sheet according to any one of claims 1 to 6, wherein the sheet has a paper base.