CA1250249A - Printing method by electrolytic colloid coagulation and colloid composition therefor - Google Patents
Printing method by electrolytic colloid coagulation and colloid composition thereforInfo
- Publication number
- CA1250249A CA1250249A CA000480015A CA480015A CA1250249A CA 1250249 A CA1250249 A CA 1250249A CA 000480015 A CA000480015 A CA 000480015A CA 480015 A CA480015 A CA 480015A CA 1250249 A CA1250249 A CA 1250249A
- Authority
- CA
- Canada
- Prior art keywords
- colloid
- group
- coagulated
- paper
- dots
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M5/00—Duplicating or marking methods; Sheet materials for use therein
- B41M5/20—Duplicating or marking methods; Sheet materials for use therein using electric current
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
- B41C1/00—Forme preparation
- B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
- B41C1/105—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by electrocoagulation, by electro-adhesion or by electro-releasing of material, e.g. a liquid from a gel
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- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Colloid Chemistry (AREA)
- Cosmetics (AREA)
- Manufacture Or Reproduction Of Printing Formes (AREA)
- Photosensitive Polymer And Photoresist Processing (AREA)
- Printing Plates And Materials Therefor (AREA)
- Printing Methods (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method of printing by electrolytic coagulation, using an improved colloid solution in association with a dyed colloid swelling agent which permits improved dye transfer from dyed coagulated images to enable very fast and accurate printing on ordinary paper. The dyed colloid swelling agent is rapidly absorbed by the coagulated colloid for dye transfer on any paper surface wetted with a paper wetting agent which is a solvent of the colloid swelling agent. The colloid is of reliable uniform quality and performance and is used in combination with a salt or acid to render the solution conductive. The colloid is selected from the group of linear synthetic colloids of high molecular weight, including polyacrylic acid and polyacrylamide resin. The swelling agent is selected from the group consisting of glycerol, sorbitol, ethylene glycol, formamide and N-methyl pyrrolydone.
The paper wetting agent is selected from the group consisting of methyl alcohol, ethyl alcohol, isopropyl alcohol, and acetone.
A method of printing by electrolytic coagulation, using an improved colloid solution in association with a dyed colloid swelling agent which permits improved dye transfer from dyed coagulated images to enable very fast and accurate printing on ordinary paper. The dyed colloid swelling agent is rapidly absorbed by the coagulated colloid for dye transfer on any paper surface wetted with a paper wetting agent which is a solvent of the colloid swelling agent. The colloid is of reliable uniform quality and performance and is used in combination with a salt or acid to render the solution conductive. The colloid is selected from the group of linear synthetic colloids of high molecular weight, including polyacrylic acid and polyacrylamide resin. The swelling agent is selected from the group consisting of glycerol, sorbitol, ethylene glycol, formamide and N-methyl pyrrolydone.
The paper wetting agent is selected from the group consisting of methyl alcohol, ethyl alcohol, isopropyl alcohol, and acetone.
Description
~0~
FIEL~ OF THE INVENTION
This invention relates to printing and, more particularly, to a method of making a printing plate by electrolytic coagulation and printing ordinary paper with the printing plate.
DESCRI TION OF PRIOR ART
In applicant s United States patent number 3,892,645 dated July 1, 1975 and entitled: "PRINTING METHOD AND SYSTEM BY
GELATIN COAGULATION, there is definecl a method for recording an image including coagulation of a colloid composition. Electric direct current is passed at desired places through a thin layer of a liquid-state colloid composition containing an electrolyte, by means of several negative electrodes and a single positive electrolytically-inert electrode in contact with the layer, thus achieving coagulation and adherence of part of the colloid to the positive electrode and removing the non-coagulated colloid composition to leave only the coagulated image.
It has been found that the patented me-thod may suffer adverse secondary effects and speed restrictlons, making it less suitable for more-demanding applications and for achieving sustained reliable performance, such as for computer printers and photocopying. Also, the colloids used in the patented method make it impossible to print on ordinary paper, since it required gelatinized paper, which is expensive. More specifically, it has been found that the albumin or gelatin used in the above-noted patent is not usually of consistent quality due to the high . ~
~P
. .
variance of its molecular weight and its different chemical pre-treatment, as well as its ability to be adversel~ affected by bacterial decornposition in ambient air.
OBJECTS OF THE INVENTION
_ _ _ It is the general object of the invention to obviate the above-noted disadvantages.
It is another object of the present inventon to provide a method of recording an image by electric coagulation, thus forming a printing plate, and printing ordinary paper therewith, the method achieving an increased printing speed and increased reliability suitable for computer printing and photocopying.
DE CRIPTIO OF I~E PRE,FE.RRED EMBODIMENTS
As in the above-noted U.S. patent, the present invention includes a method of recording an image comprising the steps of interposing a thin layer in substantially-liquid state contalning water, an electrolyte arld an electrolytically-coabulable colloid between and in contact with a plurality of negative electrodes, and A single posi~ive electrode, the positive electrode being electrolytically inert, successively and selectively biasing said electrodes with direct current for a short period of time and concurrently sweeping the positive electrode by the negative electrodes to thereby cause point-by-point selective coagulation and adherence of the colloid onto said positive electrode and removing the non-coagulated colloid, whereby the coagulated colloid is representative of a desired image. The improved method is characterized by the use of a ~Z5~
colloid selected from the group consisting of water-dispersable synthetic linear colloid polymers, of a molecular weight between lO0,000 and 600,000 and, preferably, between 200,000 and 450,000 and including polyacrylic acid and polyacrylamide resins. The uniform characteristics of the synthetic colloids, with a well-controlled molecular weight, have been found to provide reliably-uniform and superior results over the albumin and gelatin used in the above-noted U.S. patent. The electrolyte used in the composition is either an acid or a salt selected from the group consisting of lithium, sodium, potassium and ammonium chloride.
The composition also preferably includes an electrode depolarizing agent to minimi~e the deposition of gas against the electrodes. Such an agent is preferably selected from the group of manganese and nitrate compounds and H~02, which combines with the gas producecl against the electrodes upon breakdown of a water molecule into oxygen and hydrogen ions. Lead nitrate, rnanganese chloride and H22 have been found suitable as a depolarlzing agent. The positive electrode must be electrolytically inert.
Metals suitable for rnaking the positive electrode are selected from stainless steel, aluminum and tin, with stainless steel grade 316 being preferred as giving the best results. The non-coagulated colloid composition is removed by washing or scraping the positive electrode with a soft rubber squeegee. The anode with the coagulated synthetic dots adhering thereto form the printing plate. A water solution of a dye and of a swelling agent for the coagulated dots of the printing plate is then , . .
applied to the printing plate and the coagulated dots become swollen as they absorb the solvent and absorb the dye. After removing the surplus, of the dyed solution, the swelled, dyed, coagulated image is pressed in close contact with ordinary paper previously slightly wetted with an alcohol. Since the swelling agent is soluble in the alcohol, the dye of~ the dots is transferred onto the paper surface. Any ordinary paper can thus be printed, including uncoated paper, such as bond paper and coated paper, more specifically kaolin-coated and synthetic resin-coated paper. The preferred swelling agent is a water solution of a compound selected from the group consisting of one or more of glycerol, ethylene glycol and sorbitol. These compounds are soluble in the alcohol used as a paper wetting agent and swells the coagulated dots much longer and much more than just water. Thus, dye transfer from the printing plate to the paper is highly efficient, fast and acc~lrate.
Preferred alcohols for paper wetting are selected from the group consisting of methanol, ethanol and isopropyl alcohol.
These alcohols possess high paper wetting property and, therefore, the colored glycerol, ethylene glycol or sorbitol, or mixtures thereof, are absorbed by the paper fibers where they remain. The d~e transfer on paper just described cannot work with the gelatin and albumin colloids mentioned in the above-noted U.S. patent. Sorbitol and ethylene glycol have only a very slight swelling effect on gelatin or albumin and are totally unsatisfactory for the above-described printing step.
:L;2 5~2'~
Gelatinized paper must be used to effect printing from the printing plate where the coagulated dots are gelatin or albumin.
The following electrolytically-coagulable colloid composition was prepared:
PERCENT BY WEIGHT
. . .
Polyacrylic acid (Carbopol 907, a registered trademark of B.F. Goodrich) 10 [molecular weight 450,000]: 10 grams 8.77 KCl electrolyte 4 grams 3.51 water lOO ~rams 87.72 total 114 grams 100.00 This water solution has a pH of 2.25. This solution was used as a layer between the negative and positive electrodes in the above-described method for recording an image. The positive electrode was stalnless steel grade 316. The gap between the negative and positive electrodes was 50 microns. The neyative electrodes were copper-insulatad wires of 250 microns in diameter arranged in a linear array. The electrodes were successively biased by successively and selectively applying to the negative electrodes a power supply of 25 watts (50 volts and 500 milliamperes). The operating temperature was 30 C. A speed of coagulation of 300,000 dots per second was achieved, with the size of the dots being 250 microns in diameter. This means that an electric pulse at each electrode of one-three hundred 5~2~
thousandths of a second was necessar~ to effect coagulation.
The experiment was repeated several times and the coagulation results were very constant ~rom one experiment to the other. Additional experiments were repeated using the same liquid composition but using negative elec-trodes having a diameter of 125 microns instead of 250 microns. The resulting speed of coagulation was found to be 1,000,000 dots per second, that is requiring an electrical pulse for each negative elec~rode of one millionth of a second.
Comparative experiments were made using the same set-up but with gelatin and albumin as the colloid. The coagulation was very inconsistent from one experiment to the other, and the speed of coagulation using 250 microns negative electrodes was only 100,000 dots per second.
EXAMPLE II
A series of experiments were conducted for recording an image using the same electrolytically-coagulable colloid composition, but with the polyacrylic acid mentioned in Example I
replaced by a polyacrylic acid of molecular weight of 250,000 as supplied by Aldrich under code number 18128-5, with the resulting solution having a pH adjusted to 2.30. Very similar results were obtained: other experiments were carried out and with similar results using the following colloid polymer:
Polyacrylamide of molecular weight 200,000, supplied by Aldrich under code number 19-092-6, with the solution a~justed to a pH of ~.46.
~;~5~
Additional experiments were carried out with the same results, using a copolymer of polyacrylamide and of polyacrylic acid of molecular weight 250,000, as supplied by Cyanamid under the registered trademark ACCOSTRENGTH 86, with the solution adjusted to pH 4.63.
EXAMPLE_III
Experiments similar to those of the prior-mentioned examples were carried out, but while varying the voltage applied to the electrodes; it was found that the size or thickness of the coagulated dots varied in proportion to the applied voltage, thus permitting the reproduction of half-tones.
EXAMPLE IV
To the liquid electrolytically-coagulable colloid composition of any of the above noted examples, was added a depolarizing agent consisting of two percent by weight of a compound selected from lead nitrate, manganese chloride and H2O2, with even better results.
_AMPLE. V
The coagulated synthetic resin dots of the printing plate obtained from any of the foregoing examples were swollen and colored by applying thereto the following solution:
A~LZ ~
PERCENT BY WEIGHT
water soluble dye selected from Pina dyes and obtained from RIDEL-deHAEN ~West Germany~, namely:
pina yellow N 28,5995 grams 3.84 glycerol 20 c.c. or25.2 grams 19.35 water _ _00 qrams _76.~1 total 130.2 grams lO0.00 The coagulated dots became quickly and highly swollen and absorbed the dye. The surplus dye solution was then removed and the swelled, dyed coagulated image was pressed in close contact with a kaolin-coated paper previously wetted with methanol. The methano]., which is a solvent ~or glycerol, caused the transfer ~f the dye to the paper surface, resulting in the image transfer to the paper. About seven paper sheets were thus printed with the same printing plate, while recharging the synthetic dots with the dye and swelling agent each time; it was found that up to about seven sheets could be printed. To print additional sheets, it was necessary to remake the printing plate.
Each time a paper sheet was printed, there was not only a dye transfer but also a transfer of a portion of the coagulated dots. Very precise and clear images were obtained on the paper sheets.
EX~MP E VI
The same experiments were carried out as in Example V, but while using the following coloring and swelling composition:
5~
PERCENTAGE BY WEIGH.T
pina blue N 28,597 5 grams 3.61 ethylene glycol 30 c.c. 33.46 grams 24.17 or water _ 100 arams __72.22 total 138.46 grams 100.00 The paper wetting agent was ethanol and similar results as in Example V were obtained.
EXAMPLE VII
10 The same experiments as Example V were carried out but using the following coloring and swelling agent composition for treating the coagulated dots of the printing plate image:
_R ENT_ Y WEIGHT
pina violet N 28,5985 grams 3.23 15 sorbitol 50 grams 32.25 water _ 00 cirams 64.52 total 155 cJrams 100.00 Isopropyl alcohol was used as the paper wetting agent.
The dye transfer to the paper was less than in Examples V and VI, since sorbitol is a poorer solvent and, therefore, a poorer swelling agent than glycerol or ethylene glycol for the coagulated dots of the colloids named in Examples I to IV.
However, it was found that, when sorbitol is admixed with either or both glycerol and ethylene glycol, the coagulated colloid swelling ef~iciency can be adjusted for maximum dye transfer to the paper.
~z~z;~
EXAMP E VIII
The same experiments as in Examples V to VII were carried out~ but the printing step was carried out on bond paper.
This necessitated heating the printed sheet by hot-blown air to accelerate its drying, in order to prevent spreading of the dye through the paper fibers.
EXAMPLE IX
Experiments were carried out in accordance with Examples I, II and IV, while varying the voltage applied to the electrodes, followed by paper printing in accordance with Examples V to VIII, and the printed image exhibited the 64 grades of half-tones as required for image printing in photographic work EX~IPLE XI
The same experiments were carried out as in example V of the principal disclosure, but while using the following coloring and swelling composition:
PERCENT BY WEIGHT
water soluble dye: Pina blue No. 28,597 5%
N-methyl pyrrolidone 20%
water 75%
The paper wettin agent was acetone in one set of exper-iments and isopropyl alcohol in the other set.
Dye transfer was even more accurate than in Example X
during printing.
EXAMPLE XII
The same experiments with the same results were carried out as in Example IX of the principal disclosure but while varying the duration of the applied vol-tage instead of varying the vol-tage.
s.d.)
FIEL~ OF THE INVENTION
This invention relates to printing and, more particularly, to a method of making a printing plate by electrolytic coagulation and printing ordinary paper with the printing plate.
DESCRI TION OF PRIOR ART
In applicant s United States patent number 3,892,645 dated July 1, 1975 and entitled: "PRINTING METHOD AND SYSTEM BY
GELATIN COAGULATION, there is definecl a method for recording an image including coagulation of a colloid composition. Electric direct current is passed at desired places through a thin layer of a liquid-state colloid composition containing an electrolyte, by means of several negative electrodes and a single positive electrolytically-inert electrode in contact with the layer, thus achieving coagulation and adherence of part of the colloid to the positive electrode and removing the non-coagulated colloid composition to leave only the coagulated image.
It has been found that the patented me-thod may suffer adverse secondary effects and speed restrictlons, making it less suitable for more-demanding applications and for achieving sustained reliable performance, such as for computer printers and photocopying. Also, the colloids used in the patented method make it impossible to print on ordinary paper, since it required gelatinized paper, which is expensive. More specifically, it has been found that the albumin or gelatin used in the above-noted patent is not usually of consistent quality due to the high . ~
~P
. .
variance of its molecular weight and its different chemical pre-treatment, as well as its ability to be adversel~ affected by bacterial decornposition in ambient air.
OBJECTS OF THE INVENTION
_ _ _ It is the general object of the invention to obviate the above-noted disadvantages.
It is another object of the present inventon to provide a method of recording an image by electric coagulation, thus forming a printing plate, and printing ordinary paper therewith, the method achieving an increased printing speed and increased reliability suitable for computer printing and photocopying.
DE CRIPTIO OF I~E PRE,FE.RRED EMBODIMENTS
As in the above-noted U.S. patent, the present invention includes a method of recording an image comprising the steps of interposing a thin layer in substantially-liquid state contalning water, an electrolyte arld an electrolytically-coabulable colloid between and in contact with a plurality of negative electrodes, and A single posi~ive electrode, the positive electrode being electrolytically inert, successively and selectively biasing said electrodes with direct current for a short period of time and concurrently sweeping the positive electrode by the negative electrodes to thereby cause point-by-point selective coagulation and adherence of the colloid onto said positive electrode and removing the non-coagulated colloid, whereby the coagulated colloid is representative of a desired image. The improved method is characterized by the use of a ~Z5~
colloid selected from the group consisting of water-dispersable synthetic linear colloid polymers, of a molecular weight between lO0,000 and 600,000 and, preferably, between 200,000 and 450,000 and including polyacrylic acid and polyacrylamide resins. The uniform characteristics of the synthetic colloids, with a well-controlled molecular weight, have been found to provide reliably-uniform and superior results over the albumin and gelatin used in the above-noted U.S. patent. The electrolyte used in the composition is either an acid or a salt selected from the group consisting of lithium, sodium, potassium and ammonium chloride.
The composition also preferably includes an electrode depolarizing agent to minimi~e the deposition of gas against the electrodes. Such an agent is preferably selected from the group of manganese and nitrate compounds and H~02, which combines with the gas producecl against the electrodes upon breakdown of a water molecule into oxygen and hydrogen ions. Lead nitrate, rnanganese chloride and H22 have been found suitable as a depolarlzing agent. The positive electrode must be electrolytically inert.
Metals suitable for rnaking the positive electrode are selected from stainless steel, aluminum and tin, with stainless steel grade 316 being preferred as giving the best results. The non-coagulated colloid composition is removed by washing or scraping the positive electrode with a soft rubber squeegee. The anode with the coagulated synthetic dots adhering thereto form the printing plate. A water solution of a dye and of a swelling agent for the coagulated dots of the printing plate is then , . .
applied to the printing plate and the coagulated dots become swollen as they absorb the solvent and absorb the dye. After removing the surplus, of the dyed solution, the swelled, dyed, coagulated image is pressed in close contact with ordinary paper previously slightly wetted with an alcohol. Since the swelling agent is soluble in the alcohol, the dye of~ the dots is transferred onto the paper surface. Any ordinary paper can thus be printed, including uncoated paper, such as bond paper and coated paper, more specifically kaolin-coated and synthetic resin-coated paper. The preferred swelling agent is a water solution of a compound selected from the group consisting of one or more of glycerol, ethylene glycol and sorbitol. These compounds are soluble in the alcohol used as a paper wetting agent and swells the coagulated dots much longer and much more than just water. Thus, dye transfer from the printing plate to the paper is highly efficient, fast and acc~lrate.
Preferred alcohols for paper wetting are selected from the group consisting of methanol, ethanol and isopropyl alcohol.
These alcohols possess high paper wetting property and, therefore, the colored glycerol, ethylene glycol or sorbitol, or mixtures thereof, are absorbed by the paper fibers where they remain. The d~e transfer on paper just described cannot work with the gelatin and albumin colloids mentioned in the above-noted U.S. patent. Sorbitol and ethylene glycol have only a very slight swelling effect on gelatin or albumin and are totally unsatisfactory for the above-described printing step.
:L;2 5~2'~
Gelatinized paper must be used to effect printing from the printing plate where the coagulated dots are gelatin or albumin.
The following electrolytically-coagulable colloid composition was prepared:
PERCENT BY WEIGHT
. . .
Polyacrylic acid (Carbopol 907, a registered trademark of B.F. Goodrich) 10 [molecular weight 450,000]: 10 grams 8.77 KCl electrolyte 4 grams 3.51 water lOO ~rams 87.72 total 114 grams 100.00 This water solution has a pH of 2.25. This solution was used as a layer between the negative and positive electrodes in the above-described method for recording an image. The positive electrode was stalnless steel grade 316. The gap between the negative and positive electrodes was 50 microns. The neyative electrodes were copper-insulatad wires of 250 microns in diameter arranged in a linear array. The electrodes were successively biased by successively and selectively applying to the negative electrodes a power supply of 25 watts (50 volts and 500 milliamperes). The operating temperature was 30 C. A speed of coagulation of 300,000 dots per second was achieved, with the size of the dots being 250 microns in diameter. This means that an electric pulse at each electrode of one-three hundred 5~2~
thousandths of a second was necessar~ to effect coagulation.
The experiment was repeated several times and the coagulation results were very constant ~rom one experiment to the other. Additional experiments were repeated using the same liquid composition but using negative elec-trodes having a diameter of 125 microns instead of 250 microns. The resulting speed of coagulation was found to be 1,000,000 dots per second, that is requiring an electrical pulse for each negative elec~rode of one millionth of a second.
Comparative experiments were made using the same set-up but with gelatin and albumin as the colloid. The coagulation was very inconsistent from one experiment to the other, and the speed of coagulation using 250 microns negative electrodes was only 100,000 dots per second.
EXAMPLE II
A series of experiments were conducted for recording an image using the same electrolytically-coagulable colloid composition, but with the polyacrylic acid mentioned in Example I
replaced by a polyacrylic acid of molecular weight of 250,000 as supplied by Aldrich under code number 18128-5, with the resulting solution having a pH adjusted to 2.30. Very similar results were obtained: other experiments were carried out and with similar results using the following colloid polymer:
Polyacrylamide of molecular weight 200,000, supplied by Aldrich under code number 19-092-6, with the solution a~justed to a pH of ~.46.
~;~5~
Additional experiments were carried out with the same results, using a copolymer of polyacrylamide and of polyacrylic acid of molecular weight 250,000, as supplied by Cyanamid under the registered trademark ACCOSTRENGTH 86, with the solution adjusted to pH 4.63.
EXAMPLE_III
Experiments similar to those of the prior-mentioned examples were carried out, but while varying the voltage applied to the electrodes; it was found that the size or thickness of the coagulated dots varied in proportion to the applied voltage, thus permitting the reproduction of half-tones.
EXAMPLE IV
To the liquid electrolytically-coagulable colloid composition of any of the above noted examples, was added a depolarizing agent consisting of two percent by weight of a compound selected from lead nitrate, manganese chloride and H2O2, with even better results.
_AMPLE. V
The coagulated synthetic resin dots of the printing plate obtained from any of the foregoing examples were swollen and colored by applying thereto the following solution:
A~LZ ~
PERCENT BY WEIGHT
water soluble dye selected from Pina dyes and obtained from RIDEL-deHAEN ~West Germany~, namely:
pina yellow N 28,5995 grams 3.84 glycerol 20 c.c. or25.2 grams 19.35 water _ _00 qrams _76.~1 total 130.2 grams lO0.00 The coagulated dots became quickly and highly swollen and absorbed the dye. The surplus dye solution was then removed and the swelled, dyed coagulated image was pressed in close contact with a kaolin-coated paper previously wetted with methanol. The methano]., which is a solvent ~or glycerol, caused the transfer ~f the dye to the paper surface, resulting in the image transfer to the paper. About seven paper sheets were thus printed with the same printing plate, while recharging the synthetic dots with the dye and swelling agent each time; it was found that up to about seven sheets could be printed. To print additional sheets, it was necessary to remake the printing plate.
Each time a paper sheet was printed, there was not only a dye transfer but also a transfer of a portion of the coagulated dots. Very precise and clear images were obtained on the paper sheets.
EX~MP E VI
The same experiments were carried out as in Example V, but while using the following coloring and swelling composition:
5~
PERCENTAGE BY WEIGH.T
pina blue N 28,597 5 grams 3.61 ethylene glycol 30 c.c. 33.46 grams 24.17 or water _ 100 arams __72.22 total 138.46 grams 100.00 The paper wetting agent was ethanol and similar results as in Example V were obtained.
EXAMPLE VII
10 The same experiments as Example V were carried out but using the following coloring and swelling agent composition for treating the coagulated dots of the printing plate image:
_R ENT_ Y WEIGHT
pina violet N 28,5985 grams 3.23 15 sorbitol 50 grams 32.25 water _ 00 cirams 64.52 total 155 cJrams 100.00 Isopropyl alcohol was used as the paper wetting agent.
The dye transfer to the paper was less than in Examples V and VI, since sorbitol is a poorer solvent and, therefore, a poorer swelling agent than glycerol or ethylene glycol for the coagulated dots of the colloids named in Examples I to IV.
However, it was found that, when sorbitol is admixed with either or both glycerol and ethylene glycol, the coagulated colloid swelling ef~iciency can be adjusted for maximum dye transfer to the paper.
~z~z;~
EXAMP E VIII
The same experiments as in Examples V to VII were carried out~ but the printing step was carried out on bond paper.
This necessitated heating the printed sheet by hot-blown air to accelerate its drying, in order to prevent spreading of the dye through the paper fibers.
EXAMPLE IX
Experiments were carried out in accordance with Examples I, II and IV, while varying the voltage applied to the electrodes, followed by paper printing in accordance with Examples V to VIII, and the printed image exhibited the 64 grades of half-tones as required for image printing in photographic work EX~IPLE XI
The same experiments were carried out as in example V of the principal disclosure, but while using the following coloring and swelling composition:
PERCENT BY WEIGHT
water soluble dye: Pina blue No. 28,597 5%
N-methyl pyrrolidone 20%
water 75%
The paper wettin agent was acetone in one set of exper-iments and isopropyl alcohol in the other set.
Dye transfer was even more accurate than in Example X
during printing.
EXAMPLE XII
The same experiments with the same results were carried out as in Example IX of the principal disclosure but while varying the duration of the applied vol-tage instead of varying the vol-tage.
s.d.)
2~1 SUPPLEMENTARY DISCLOSURE:
Since the filing of the present application a great number of additional chemicals have been tested for carrying out the different s-teps of applicant's method.
The following have been found: the principal disclosure mentions that, as a swelling agent, glycerol, sorbitol and ethylene glycol are suitable. It has now been found that increased swelling can be achieved by the use of formamide or N-methylpyrrolidone.
As a wetting agent, it has now been found that acetone can be used to great advantage.
Finally, it has been found -that not only polyacrylic acid and polyacrylamide resins can be used as the colloid but also copolymers of these two substances.
Finally, it has been found that the si~e or thickness of the coagulated dots may be varied not only by varying the applied voltage, but also by controlling the duration of the electric pulse applied to the colloid layer.
The following experiments were effected:
EXA~1PLE X
The same experiments were carried out as in Example V
of the principal disclosure but while using the following coloring and swelling agent:
PERCENT BY WEIGHT
Pina blue No. 28,597 5 ethylene glycol 20~
formamide 20%
water 55%
The paper wetting agent was acetone instead of methanol. Dye -transfer during printing was more accurate than in Example V.
-12- ~s.d.) ~ .
Since the filing of the present application a great number of additional chemicals have been tested for carrying out the different s-teps of applicant's method.
The following have been found: the principal disclosure mentions that, as a swelling agent, glycerol, sorbitol and ethylene glycol are suitable. It has now been found that increased swelling can be achieved by the use of formamide or N-methylpyrrolidone.
As a wetting agent, it has now been found that acetone can be used to great advantage.
Finally, it has been found -that not only polyacrylic acid and polyacrylamide resins can be used as the colloid but also copolymers of these two substances.
Finally, it has been found that the si~e or thickness of the coagulated dots may be varied not only by varying the applied voltage, but also by controlling the duration of the electric pulse applied to the colloid layer.
The following experiments were effected:
EXA~1PLE X
The same experiments were carried out as in Example V
of the principal disclosure but while using the following coloring and swelling agent:
PERCENT BY WEIGHT
Pina blue No. 28,597 5 ethylene glycol 20~
formamide 20%
water 55%
The paper wetting agent was acetone instead of methanol. Dye -transfer during printing was more accurate than in Example V.
-12- ~s.d.) ~ .
Claims (13)
1. A method of recording an image and forming a printing plate and then printing the image on an end-use paper support, comprising the steps of interposing a thin layer in substantially liquid-state, containing water, an electrolyte and an electrolytically-coagulable colloid between and in contact with a plurality of negative electrodes disposed side by side and a single positive, electrolytically-inert electrode, successively and selectively electrically, negatively biasing said negative electrodes relative to said positive electrode with direct current for a short period of time, to thereby cause point-by-point selective coagulation and adherence of the resulting coagulated colloid dots onto said positive electrode, removing the non-coagulated colloid, so that the coagulated dots are representative of a desired image, said positive electrode with the coagulated dots adhering thereto, forming said printing plate, impregnating said dots with an impregnating water solution of a coagulated colloid swelling agent and of a water soluble dye to cause swelling of and dye absorption by said dots, wetting an end-use paper sheet with a paper wetting agent which is a solvent for the swelling agent, pressing said printing plate against said wetted end-use paper support to transfer the dyed image onto the latter, and drying said paper support, the colloid being selected from the group consisting of water dispersable synthetic linear colloid polymers of molecular weight between 100,000 and 600,000, said swelling agent being selected from the group consisting of glycerol, ethylene glycol, and sorbitol.
2. A method as defined in claim 1, wherein said colloid is selected from the group consisting of polyacrylic acids and polyacrylamides and having a molecular weight of between 200,000 and 450,000.
3. A method as defined in claim 2, wherein the amount of said colloid in said layer is between 6% and 12% by weight and the amount of electrolyte is sufficient to obtain a layer having a pH lying between 2.25 and 5.
4. A method as defined in claim 3, wherein said impregnating solution includes betwen 3% and 5% by weight of said dye and between 19% and 40% by weight of said swelling agent.
5. A method as defined in claim 2, wherein said paper wetting agent is selected from the group consisting of methanol, ethanol and isopropyl alcohol.
6. A method as defined in claim 2, wherein the electrolyte is selected from the group consisting of lithium, sodium and potassium chlorides and of ammonium chloride.
7. A method as defined in claim 2, wherein the positive electrode is made of a metal selected from the group consisting of aluminum, tin and stainless steel.
8. A method as defined in claim 7, wherein the positive electrode is made of stainless steel, grade 316.
9. A method as defined in claim 7, wherein a variable voltage is applied across said negative and positive electrodes to vary the amount of coagulated colloid forming the dots.
Claims supported by the supplementary disclosures:
Claims supported by the supplementary disclosures:
10. (S.D.) A method as defined in claim 1, wherein said swelling agent is selected from the group consisting of formamide and N-methylpyrrolidone.
11. (S.D.) A method as defined in claim 2, wherein said colloid is selected from the group consisting of copolymers of polyacrylic acids and polyacrylamides.
12. (S.D.) A method as defined in claims 10 or 11, wherein said paper wetting agent is acetone.
13. (S.D.) A method as defined in claims 7 or 8, wherein the duration of the voltage bias applied across said negative and positive electrodes is controlled to vary the amount of coagulated colloid forming the dots.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US60955584A | 1984-05-11 | 1984-05-11 | |
| US06/609,555 | 1984-05-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1250249A true CA1250249A (en) | 1989-02-21 |
Family
ID=24441277
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000480015A Expired CA1250249A (en) | 1984-05-11 | 1985-04-25 | Printing method by electrolytic colloid coagulation and colloid composition therefor |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0160979B1 (en) |
| JP (1) | JPS60245592A (en) |
| KR (1) | KR850008299A (en) |
| AT (1) | ATE61764T1 (en) |
| AU (1) | AU578092B2 (en) |
| BR (1) | BR8502230A (en) |
| CA (1) | CA1250249A (en) |
| DE (1) | DE3582188D1 (en) |
| ES (1) | ES8605417A1 (en) |
| ZA (1) | ZA853270B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1205778A (en) * | 1984-05-16 | 1986-06-10 | Adrien Castegnier | Image reproduction by in plane electro-coagulation of a colloid |
| CA1279603C (en) * | 1986-02-20 | 1991-01-29 | Adrien Castegnier | Monochromic and polychromic printing of an image reproduced by electro-coagulation of a colloid |
| CA1249238A (en) * | 1986-07-18 | 1989-01-24 | Adrien Castegnier | Method of preventing undesirable gas generation between electrodes of an electrocoagulation printing system |
| JPH0641221B2 (en) * | 1988-01-25 | 1994-06-01 | キヤノン株式会社 | Image forming method, recording material and image forming apparatus |
| US5055380A (en) * | 1989-12-18 | 1991-10-08 | Eastman Kodak Company | Method of forming a color-differentiated image utilizing a metastable aggregated group ib metal colloid material |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3752746A (en) * | 1972-02-25 | 1973-08-14 | A Castegnier | Electrolytic printing method and system |
| US3892645A (en) * | 1973-06-06 | 1975-07-01 | Adrien Castegnier | Printing method and system by gelatin coagulation |
| US4165741A (en) * | 1975-12-29 | 1979-08-28 | Process Shizai Co., Ltd. | Heat-sensitive recording materials and recording process of using the same |
| DE3416867A1 (en) * | 1984-05-08 | 1985-11-14 | Hoechst Ag, 6230 Frankfurt | ONE-STEP ELECTROCHEMICAL IMAGING METHOD FOR REPRODUCTION LAYERS |
-
1985
- 1985-04-25 CA CA000480015A patent/CA1250249A/en not_active Expired
- 1985-05-01 ZA ZA853270A patent/ZA853270B/en unknown
- 1985-05-06 KR KR1019850003073A patent/KR850008299A/en not_active Application Discontinuation
- 1985-05-07 AU AU42059/85A patent/AU578092B2/en not_active Ceased
- 1985-05-08 EP EP85105621A patent/EP0160979B1/en not_active Expired - Lifetime
- 1985-05-08 DE DE8585105621T patent/DE3582188D1/en not_active Expired - Lifetime
- 1985-05-08 AT AT85105621T patent/ATE61764T1/en not_active IP Right Cessation
- 1985-05-10 JP JP60098140A patent/JPS60245592A/en active Granted
- 1985-05-10 BR BR8502230A patent/BR8502230A/en unknown
- 1985-05-11 ES ES543069A patent/ES8605417A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60245592A (en) | 1985-12-05 |
| ZA853270B (en) | 1985-12-24 |
| BR8502230A (en) | 1986-01-14 |
| EP0160979A3 (en) | 1987-08-12 |
| EP0160979A2 (en) | 1985-11-13 |
| ATE61764T1 (en) | 1991-04-15 |
| ES8605417A1 (en) | 1986-03-16 |
| JPH0548750B2 (en) | 1993-07-22 |
| AU4205985A (en) | 1985-11-14 |
| AU578092B2 (en) | 1988-10-13 |
| ES543069A0 (en) | 1986-03-16 |
| EP0160979B1 (en) | 1991-03-20 |
| DE3582188D1 (en) | 1991-04-25 |
| KR850008299A (en) | 1985-12-16 |
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