JPS607262B2 - Erasable diazotype paper intermediate - Google Patents

Description

[Detailed description of the invention] This invention relates to erasable diazotype paper intermediates.

More particularly, the present invention provides a non-curling erasable diazo which has excellent developability and is easily erasable using any conventional erasing means without leaving image ghosts. Related to type paper. The present invention provides a method of first coating a light-transmissive support material with a non-aqueous solution of a rubbery barrier layer material, and then coating the formed barrier layer with a non-aqueous solution of a diazo-containing composition, which can be obliterated. It is contemplated to produce photosensitive paper by forming photosensitive diazotype paper. Diazotype intermediates serve two fundamental roles for engineers, architects, designers, and draftsmen: as proofreading of old drawings and as base elements for the production of new drawings; and as original drawings. It plays a role.

When proofreading a drawing or creating a new drawing, all repetitive elements of the drawing are diazotyped and only new information is rendered. This drawing usage requires a good base paper with a good drawing surface.
Also, surface damage such as from correction fluid should be avoided. In addition, erasable diazotype intermediates can be erased from drawings by simple erasure, thus providing draftsmen with a useful tool. Destruction of diazotype papers is permitted by inserting one or more intermediate or barrier layers between the base paper and the diazo or photosensitive layer. Any suitable interlayer must necessarily have a strong affinity for the barrier layer and a good hold-out so that the diazo compound does not penetrate or migrate. The characteristics required for erasable diazo intermediate paper are good pencil and ink receptivity, visual transparency,
Erasability by hand or machine with little or no image marks or ghosts after erasure, surface gloss or degradation with good UV transparency to enable rapid diazo copying, and non-flexibility or curling. It is a lack of habit. In the art, erasable diazotype papers are manufactured by, for example, first coating a clarified paper with an aqueous solution of a polymeric substance to form a barrier layer and then overcoating this with an aqueous solution of a diazotype photosensitive liquid. method is known.

Materials for obtaining such intermediate papers are disclosed, for example, in US Pat. No. 4,058,39.

Other prior art documents disclosing background, materials and methods for manufacturing erasable paper include U.S. Pat.
No. 68, General No. 264, No. 2861008, No. 3418469, No. 3624021, No. 36
There are No. 27563 and No. 3813261. Unfortunately, transparent erasable paper generally has a tendency to produce "ghosts" when it is folded, erased or scratched, for example. "Ghost" is
Caused by damage to the materials used to make paper. Ghost lines resulting from damage block light and cause undesirable lines to form on copies on other sheets of paper.
Additionally, known erasable diazotype intermediate papers tended to yellow more rapidly with long-term ultraviolet exposure.
Furthermore, known formulations for making erasable diazotype papers exhibit a tendency to curl in one or more manufacturing steps, resulting in many defects in the finished product when such papers are used. bring profit. Although known erasable diazotype papers have made valuable contributions to the industry, hitherto known erasable papers often lack one or more of the characteristics most desirable in erasable intermediate papers. That should be recognized. In accordance with the present invention, a simple and practical formulation is provided that allows for the two-step production of erasable photosensitive diazo-type papers that exhibit all of the properties desired.

Erasable papers made using the formulations of the present invention have good pencil and ink receptivity, are easily erasable by conventional erasing means, and, after erasing, easily remove pencil or ink in the erasure areas. It accepts virtually no scratches with ordinary drafting equipment, leaves no "ghosts" after erasure, and has no curling habits during or after manufacture. Various other objects, advantages, and advantages of the present invention will become readily apparent from the detailed description that follows.

First, a transparent support is coated with a non-aqueous solution of an aliphatic alcohol solvent-insoluble rubber coating, and after drying, an aliphatic alcohol-soluble composition consisting of a diazonium compound, an azokuplar, and an aliphatic oxycarboxylic acid is applied to this barrier coating. By overcoating with a photosensitive solution consisting of a non-aqueous solution of It has been discovered that it is possible to produce polydiazotype paper.

Preferred embodiments of the present specification will be described below. The term "clarified" paper or support herein refers to a light-transmissive flexible support that is inherently transparent or any well-known process in which paper is treated to impart desired light transparency. means a light-transmissive flexible support made transparent by a method.

When producing erasable photosensitive diazotype papers, the support must be protected from penetration by the photosensitive liquid.

Penetration of the diazo material into this support is detrimental and greatly hinders image erasure on paper. In order to prevent such penetration, it is necessary to interpose a coating of barrier material between the support material (base) and the photosensitive layer. However, any barrier material used must allow the transmission of light, be flexible with the support, be relatively easy to remove by erasure, and have good adhesion to the support and photosensitive layer. Moreover, it must be completely insoluble in the photosensitive liquid. More importantly, the barrier layer should not tolerate curling of the support. The barrier layer formulations of the present invention include aliphatic alcohol-insoluble elastomers or thermoplastics, including styrenated copolymers and terpolymers, such as polyurethanes, vinyltoluene-Q-methylstyrene copolymers, polystyrene butadiene. copolymers, polystyrene acrylate terpolymers, polybutadiene rubber, polystyrene ethylene butylene block copolymers and pentaerythritol esters of dimeric resin acids, and non-aqueous solutions of mixtures thereof. Most organic solvents are suitable as barrier layer composition solvents, with the exception of aliphatic alcohol solvents, which in preferred embodiments are toluene, methyl ethyl ketone, methyl cellosolve acetate and mixtures thereof. What is essential is that the barrier layer is not soluble in either the photolayer formulation solvent or any of the optional components of the photolayer formulation. The photosensitive layer is applied directly to the dry barrier layer coating.

One of the main advantages of the present invention is that any known coating method can be used to apply the barrier layer and the photosensitive layer. Good results can be obtained, for example, by applying the liquid with a roller and removing excess liquid with a wire-wound rod. Although not critical, the barrier layer generally has a thickness of about 0.
Applied at a thickness of 1 to 0.5 mil. The photosensitive layer of the present invention consists of a non-aqueous solution of a polymeric resin binder soluble in aliphatic alcohol, a diazonium salt, an azo coupler, an acid and a dye color fixing agent.

It is important to the invention that no water be present in either the barrier layer solution or the photosensitive layer solution. A combination of methanol and methyl cellosolve has been found to be highly satisfactory as a photosensitive formulation solvent. The ratio of methanol to methyl cellosolve is not critical, but in preferred embodiments ranges from 2:1 to 8:1. As previously mentioned, the well-known roller and wire-wound rod methods may be advantageously used to apply the photosensitive liquid and remove excess liquid. There are many diazonium compounds known in the art that can be successfully used in the formulations of the present invention.

2,5-diethoxy4-morpholinobenzenediazonium zinc chloride has been found to be suitable in practice, but also N-ethyl-N-hydroxyethyl-p-phenylenediamine, 2,5-diethoxy4- Pyrrolidinoaniline, 2,5-dimethoxy-4-morpholinoaniline and N-N-diethyl p
- Salts of diazonium zinc chloride or hexafluorophosphate derived from phenylene diamine give excellent results.

Any suitable couplers such as resorcinol, phenol and catechol can also be used in the light-sensitive material of the invention.

To prevent premature coupling, aliphatic oxycarboxylic acids such as citric acid, malic acid, tartaric acid and lactic acid are used in the photosensitive solution. The use of zinc chloride as a stabilizer also increases the shelf life of photosensitive material formulations. Additionally, photosensitive material formulations generally include diazo dye color fixing agents such as thiourea. As is well known in the art, erasability is enhanced by the inclusion of silica. In preferred embodiments of the invention, the photosensitive layer contains about 1 to
Includes silica having a particle size in the 15-F range. The respective concentrations of the photosensitive diazo compound and the coupling agent used in the photosensitive layer of the present invention are present in stoichiometric amounts. The following examples illustrate formulations used to make erasable diazotype papers of the present invention.

In all examples, a clarified paper support was used. Also, in all examples, the surface of the support paper was coated with a liquid barrier layer formulation. After coating the barrier layer, the barrier-coated support was coated with a photosensitizer formulation. In each example, the barrier layer and photosensitive layer were applied by conventional roller coating, and excess photosensitive solution was removed by rolling over a wire-wound rod. Example 1 Barrier layer methyl ethyl ketone 85c
c Methyl cellosolve acetate 15cc
Polyurethane 8 Vinyltoluene-Q-methylstyrene copolymer 5 Photosensitive layer Methanol
85CC methyl cellosolve
15 ccl/2 (seconds) *Cellulose acetate propionate 5 evenings (1 citric acid)
．． 0 thiourea 0.2
Zinc chloride 1.0 Resorcin sulfide 3.6 4-
Diazo-2,5-diethoxyphenylmorpholine zinc chloride 2.8 and 4.
4.0 t * Eastman Kodak Viscosity Indication Also, polyurethane in amounts ranging from 3 to 24 ta and vinyltoluene-Q in amounts ranging from 1.85 to 15 ta.
Various barrier layer formulations containing methylstyrene copolymers have been successfully prepared for use in the present invention.

The coated diazotype intermediate prepared in accordance with this example was imagewise exposed through a translucent original to a mercury vapor lamp, such as those conventionally found in diazotype copiers, and then passed through an ammonia vapor atmosphere at 90 qC. . the result,
An intense sepia azo dye image was developed on a flexible light-transparent support. The lines marked thereon could then be easily and cleanly erased with a conventional soft eraser or by mechanical erasing means. Example Lovalya layer toluene 100
CC polystyrene butadiene copolymer 4 polystyrene acrylate terpolymer 2 tabinyltoluene-Q-methylstyrene copolymer 0.5 photosensitive layer methanol 6
5CC methyl cellosolve
Cellulose acetate propionate of 35ccl EC
5 parts citric acid 1.5 parts thiourea 1.5 parts zinc chloride 1.0 parts diresorcin sulfide 3.5 parts 4-diazo-205-diethoxyphenylmorpholine zinc chloride 2.8 parts and 2 parts
The amounts of the three elastomers were varied when preparing other barrier layers used in the manufacture of erasable papers.

Thus, the amount of polystyrene-butadiene copolymer was reduced to about 2
Excellent barrier properties were obtained when the amount of polystyrene-acrylate terpolymer was 1 to 10 mm and the amount of vinyltoluene-Q-methylstyrene copolymer was about 0.25 to 2.5 mm. I found Shiroko. The coated diazotype intermediate prepared according to this example is imagewise exposed through a translucent original to a mercury vapor lamp such as conventionally found in diazotype copiers, and then exposed to
It was passed through an atmosphere of ammonia vapor.

As a result, an intense sepia colored Azo dye image was developed on the flexible light-transmissive support. The lines marked thereon could then be easily and cleanly erased with a conventional soft eraser or by mechanical erasing means.
Example m (reference example) Barrier layer toluene 10
0CC Polystyrene Butadiene Rubber 13 The photosensitive layer of this example was prepared using the same formulation used in Example B.

Example m (reference example) Barrier layer toluene 100
CC polystyrene butadiene rubber 7 Pentaerythritol ester of dimer resin acid 2 The photosensitive layer of this example was prepared using the same formulation used in Example B.

Example V (reference example) Barrier layer toluene 10
0 cc polystyrene butadiene rubber 5 cc Polystyrene ethylene butadiene rubber 5 cc Pentaerythritol ester of dimer resin acid 1.5 cc The photosensitive layer of this example was prepared using the same formulation used in Example B.

The polyurethane used in the barrier layer in the above example was 2000F.
melting point, glass transition temperature of -34°C, molecular weight of about 50,000 and solids content in THF of 15%, at 25°C, about 5
It had a viscosity range of 00 to 80 specific ps.

Pynyltoluene-Q-methylstyrene has a softening point of 75°, a melt viscosity of 100 poise at 0°, and a melt viscosity of 1000°.
It was identified by a melting point of 0 and a specific gravity of 1.04 at 25o0. The polystyrene butadiene copolymer that can be used is 3
Mooney viscosity of 8-46 and pine. It had a styrene composition of 5-24.5%. The polystyrene acrylate terpolymer has a softening point of 155°C (ring and ball method) and a softening point of 3 in xylene.
It had the physical properties of a Brookfield viscosity of 40 specific ps at 3%, a glass transition temperature of 61° C., and a critical cosolution temperature of 160 F at 33% in xylene. The polystyrene-ptadiene copolymer of the above "example" has a specific gravity of 0.92 and a specific gravity of 0.93.
It was a styrene-butadiene radical block copolymer with a styrene content of 30% and a Brookfield viscosity of 51 ps at 20% in toluene.
The pentaerythritol ester of the dimeric resin acid is 185
Softening point of ~197qC, acid number of 25, 50% solids in inorganic acid, Gardner 1 Holt scale (A-Z) at 25qo
Viscosity of T~x at and 1.09 at 25/25oo
It had a specific gravity of The polystyrene ethylene flock copolymer also had a tensile strength of 650 msi, an elongation at break of 500%, a styrene/rubber ratio of 30/70, and a solution viscosity of 80 ps at 2% solids in toluene. . "example"
Erasable papers made using the formulation did not roll up or wrinkle during or after application of either the barrier layer or the photosensitive layer.

Furthermore, erasable diazotype papers made using the formulations of the present invention had excellent receptivity with hard and black pencils and inks. The lines marked thereon could then be easily and cleanly erased with a conventional soft eraser or mechanical erasing means. Very importantly, the paper showed clear receptivity to both pencil and ink stamps in the erasure area. This paper showed remarkable stability without any yellowing tendency even after long-term exposure. It will be understood that changes in coating methods, component proportions and materials may be made without departing from the spirit and scope of the invention.

Claims (1)

[Claims] 1. A light-transparent diazo-type intermediate comprising a clarified paper support, a first dry barrier coating on the paper support, and a second dry photosensitive layer overcoated the first barrier coating; The first coating film is a non-aqueous solution prepared by dissolving polyurethane and vinyltoluene-α-methylstyrene copolymer in a mixture of methyl ethyl ketone and methyl cellosolve acetate, or a polystyrene-butadiene copolymer or polystyrene acrylate terpolymer in toluene. and a non-aqueous coating solution prepared by dissolving a vinyltoluene-α-methylstyrene copolymer, and the second photosensitive layer is a non-aqueous, aliphatic alcohol-soluble photosensitive layer containing a diazo compound. and wherein the barrier layer is insoluble in the photosensitizer formulation and has good properties for both the photosensitive layer and the paper. A light-transmitting diazo type intermediate that has adhesive strength, has no curling curls, and can be erased.