GB2075701A

GB2075701A - A laminated product for use in duplicating an image by means of radiation, and a process for utilising the laminated product

Info

Publication number: GB2075701A
Application number: GB8112041A
Authority: GB
Original assignee: Mecanorma SA
Current assignee: Mecanorma SA
Priority date: 1980-04-16
Filing date: 1981-04-16
Publication date: 1981-11-18
Also published as: NL8002231A; FR2480953A1; DE3115615A1

Abstract

The invention relates to a laminated product for duplicating an image when subjected to at least one infra-red and/or ultra-violet radiation of predetermined wave-length, and to duplicating process employing such product. In one embodiment, the laminated product comprises a sensitive layer sandwiched between substrates, the sensitive layer including a prepolymer or polymer which can be polymerised, cross-linked or degraded by a first predetermined wave-length radiation and being colourless before it is subjected to this radiation. The sensitive layer also includes one or more normally colourless leucocyanide dyes in which photo-ionozation is caused by means of another radiation of the same or different wave-length. The sensitive layer also includes the combination of a diazo-component and a coreacting component, which is colourless before application of the first radiation.

Description

SPECIFICATION A laminated product for use in duplicating an image by means of radiation, and a process for utilising the laminated product The invention relates to a laminated product which is adapted to duplicate, i,e, reproduce or copy, an image by application of radiation, which consists of at least a substrate and a sensitive layer.

Such a product is described in Dutch Patent Application No: 79.06405, the product or element consisting of a first substrate, a sensitive layer, an image-forming layer and a second substrate, The sensitive layer is transparent, and is made of a substance which is polymerised by radiation, or else copolymerised, and then exhibits adhesive and cohesive properties. The image-forming layer consists of a dye, for example Ti02 which becomes opaque when using this system as dry transport product, it is better to add a binding agent layer between the image-forming layer and the second substrate.

Dutch Patent Application No: 79.06405 is different from United States Patent No: 3.353.955 in which is described a system which consists of a first and a second substrate between which is designed a very thin film of a sensitive preparation. The influence of the necessary dye impedes the polymerisation for the production of a visible image.

Dutch Patent Application No: 79.06405 allows this difficulty to be coped with because the dye is placed in a separate image-forming layer.

Over and above the difficulty due to the presence of a such separate layer, the element according to Dutch Patent Application No: 79.06405 has the disadvantage that its use in duplication processes is limited to the negative printing technique. Taking in consideration that an opaque image-forming layer is used, it is not possible to use a positive reflex printing technique.

The object of the present invention is to provide an element which does not have these disadvantages.

To this end, according to the present invention, the layer which forms the colour consists of a light or transparent (pre)polymer, which is polymerised cross-linked or degraded by a preset or predetermined wave-length radiation, and consists of one or several colourless dyes which react to a preset or predetermined wave-length radiation.

Leucocyanide dyes are used, in preference, in the sensitive layer which forms the colour or contrast.

The element according to the invention is preferably a laminate of one first and one second substrate between which is placed the colour-forming layer. Preferably, this colourforming layer consists of a colourless combination of a diazo-component, preferably diazosulphate, and a coreacting component,which can be activated by the addition of heat andor alkali releasing agents.

The invention also relates to an imageduplication process in which a predetermined wave length radiation is applied through an original to an element according to the invention.

According to a preferred process, the radiation to which the dyes of the image-forming layer react is passed through an original, onto an element according to the invention, then the original is separated, a radiation to which the (pre)polymer which is present in the sensitive layer reacts, is applied, and the said (pre)polymer allows colour or contrast formation by the said radiation with a strong absorption, and then the different components of the laminated element or product are separated.

According to another preferred process of the invention, an original is located under a element according to the invention, and the element is irradiated by an infra-red radiation such that the radiation absorbed by the original in its dark or black areas, is converted into heat, which activates the diazo-component and coreacting component combination where the dye colouration is generated; then irradiation is effected, if necessary, after separation of the original, with radiations of one or several wavelengths which generate the reaction of the (pre)polymer in the areas of the colour-forming sensitive layer in which the colouration or formation of the said dye is not generated, the degradation of the diazo-salts and the colourless dyes in the areas which are not yet coloured in the sensitive layer, and then the components of the laminated product are separated.

Therefore the invention offers a one-step photocopy process able to generate, without the disadvantage of a wet process, a drytransferable copy a transparent element or an opaque original (positive) and simultaneously through the automatic or manual separation of the components, a non-transferable negative of the original having non-actinic properties, and able to be used for standard dark-room applications.

In order that the invention may be more readily understood, reference will now be made to the accompanying drawings, in which: Figures 1 to 4 are schematic sectional views of a laminated product or element embodying the invention, and show the different sequential steps of the duplicating process or operation utilising this product; and Figures 5 to 6 are schematic sectional views of a second embodiment of laminated product or element, ad show the steps of an alternative duplicating operation or process utilising this laminated product.

The laminated product shown in Figs. 1 to 4 consists of a sensitive layer (1) placed between two substrates (2) and (3) made of a material transparent to the radiation used in operation of the duplicating system or process.

The layer (1) may consist of only one layer, or of several laminated superposed layers.

A transparent or opaque original (4) to be duplicated, is placed under the substrate (2) and brought into close contact with the latter.

The sensitive layer (I) is composed of a photochrome and photo (pre)polymer compound consisting of: 1. A polymerisable cross-linkable or degradable (pre)polymer which reacts to an infrared radiation of a predetermined wave-length, and which is colourless before such irradiation.

2. One or more leucocyanide dyes which are colourless before the irradiation, and which react to a preset wave-length radiation identical to or different from the radiation mentioned in 1 above.

3. A colourless diazo/coreacting component combination which is not active at room temperature but wich can be activated by heat and/or alkali releasing agents to form a colour. This dye must have astrong absorption power with regard to the radiation mentioned in 1. above, i.e. the radiation under which the (pre) polymer reacts.

For this purpose, in preference, heat-sensitive diazo-salts which are indifferent to the radiation mentioned in 1. above will be used.

In order to operate or utilise the abovedescribed system or laminated element, a first suitable infra-red energy radiation (IR) is sent through the substrate (2). A certain amount of this radiation (IR) passes through the substrate (2), then through the sensitive layer or layers (1) and then reaches the original (4). The light areas (5) of the original image reflect most of this radiation back to the sensitive layer (1), while the dark areas (6) of the image absorb the radiation and convert it into heat.

This heat is reflected back, as indicated at F in Fig. 2, to the sensitive layer (1), where the heat causes the dye forming (i.e. colouring) reaction, indicated at (7), between the diazo and the coreacting components. This dye colouration (7) generated by heat is a strong colouration, and therefore absorbs a great amount of the infra-red energy which generated the photo (pre)polymer reaction Further, radiations are applied in one step or several sequential steps with energies of one or several wave-lengths Atr A2 (Fig. 3) in order to efface or neutralise the remaining sensitivity of the dye forming combination (as described in 3 hereabove) by a reaction of diazo-salts.These radiations Al, A2 can be applied through the substrate (2) or, after automatic or manual separation of the original (4), through the second substrate (3), or alternatively through the two substrates (2) and (3). At this time by subsequent application of another radiation, the photo (pre)polymer is polymerised, cross-linked or degraded, which gives rise to changes in its bond and cohesion properties as indicated at (8) in Fig. 4. Therefore, it is separated or able to be separated from the first substrate (2) and/or bound to the second substrate (3) and/or its adhesive ness to the first substrate (2) is decreased, in order to enable its subsequent transfer to another substrate.

In the areas (9) (Figs. 3 and 4) in which strong colouration is generated, thanks to the reaction of the diazo/coreacting compound, the greatest amount of the ultra-violet energy is absorbed due to all physical and chemical alteration of the photo(pre)polymer is avoided, which could be generated by simultaneous or next radiation with an ultra-violet energy of the same or different wavelength. Then, a photo-ionisation reaction is generated in one or several normally colourless leucocyanide dyes, by which all the product or system areas are coloured, except the areas where a strong colouration is generated by the diazo-coreacting component system.

The non-polymerised areas (9) (Fig. 4) of the photo (pre)polymer show a typical tackiness due to the polymer, which is the same as it was before the radiation application. The attraction or the adhesive power of this (pre)polymer, in the non-polymerised areas (9), is then stronger towards the first substrate (2) than towards the second substrate (3). Nevertheless, there is an attraction or adhesive power which is stronger towards other substrates than towards the substrates (2), (3) between which it was laminated, when such other substrates are applied under an adequate pressure.

Finally, the first and second substrates are manually or automatically removed, for example by separating them, resulting in the production of a positive image or copy (9) of the original visible on the first substrate (2), and a negative image or copy (8) of the positive original, with non-actinic colouration, which can be used in a standard dark-room.

The said positive copy (9) can be drytransferred by rubbing on the opposite side of the first substrate (2), on any other substrate which has a higher attraction or adhesive power than that created between the photopolymer/ dye combination and the first substrate (2).

On the other hand, the invention offers a one-step duplication system which produces a dry-transferable positive from a negative origi nail, without wet processing.

Another process of utilising the laminated element is schematically shown at Figs. 5 and 6. These Figs. show a laminated product or equipment embodying the invention, which consists of a sensitive layer (I 0) placed between two substrates (1 1) and (12) transpar ent to the radiation employed, and a negative original (13) placed over the material or element (10) (11) and (12).

In this case, the sensitive layer (10) does not include the diazo/coreacting component combination indicated hereabove and the said infra-red is no longer used. In this case, the image is produced by the leucocyanide dyes, the colours of which are sequentially and specifically developed by the frequency and the quality of the ultra-violet energy which passes through the clear areas of the transparent negative (13) and which falls on the laminated material (10) (11) (1 2).

In this case, this negative original (13) is not placed behind but before the element, taking into consideration that the reflectance/pressure effect is no longer used.

In order to start the process utilising this element, first of all, a suitable wave-length ultra-violet radiation 3 is transmitted through a negative original placed between the ultraviolet source and the first substrate, the part of this 3 radiation which does not fall on the opaque areas (14) of the negative (13), passes through the first substrate and reaches the sensitive photopolymer photoforming component.

A group of leucocyanide dyes, sensitive to the ultra-violet frequency used, is photo-ionized and develops a strong colouration (15) which absorbs a great amount of the ultraviolet energy at the wave-length to which the photo (pre)polymer is itself sensitive.

Then, after separation of the negative (13), a second ultra-violet radiation is applied to the laminated product at the wave-length at which the photo(pre)polymer is sensitive, so that the photo(pre)polymer reacts and/or is polymerised in all the remaining clear areas (16).

Thus, the polymer is transferred in these areas (16) from the substrate (11) to the second substrate (12). Then, a separation of the components allows the production of a dry-transferable positive image (15) on the said first substrate (11). According to an aternative of this process, a radiation can be transmitted through a negative, having a frequency of an ultra-violet light, so that the photochrome/ photo (pre)polymer reacts causing polymerisation and a strong colouration is then generated due to the leucocyanide dyes which react at the same frequency.

Thanks to this polymerisation of the areas exposed to the radiation, the polymer can be deliaminated from the first substrate (11), whereafter a dry-transfer can be carried out by mechanical means, for example by rubbing.

The transfer product thus obtained can show an adequate tackiness allowing a drytransfer, in the absence of a separate binding layer, because there is no polymerisation at the level of the side of the photo(pre)polymer which is exposed to the air, this tackiness being due to the presence of oxygen in the air.

It will be understood that the invention is not limited to the processes and products described herein, and various changes may be made while remaining within the scope of the invention as defined in the appended claims.

Claims

1. A laminated product for the duplication of an image by at least one intra-red and/or ultra-violet radiation of predetermined wavelength, which consists at least of one substrate provided with a sensitive layer, said sensitive layer consisting of a prepolymer or polmer able to be polymerised, cross-linked or degraded by first predetermined wave-length radiation, and being colourless before the application of this radiation, said sensitive layer also comprising one or several normally colourless dyes in which, in use, photo-ionization is generated by another radiation of the same wave-length as the said first radiation or of a different wave-length.

2. A laminated product as claimed in claim 1, in which the or each dye is a leucocyanide dye.

3. A laminated product as claimed in claims 1 or 2, which comprises a second substrate which covers the said sensitive layer, at least one of the said substrates being transparent to the said radiations.

4. A laminated product as claimed in claims 1, 2 or 3, in which said sensitive layer also comprises a colourless combination of a diazo-component and a coreacting component which is stable at room temperature and can be activated by heat and/or by alkali releasing agent, which combination does not react to said radiations which produce the polymerisation of the said polymer or prepolymer

5. A duplicating process for utilising the product claimed in any of claims 1 to 4, in which at least one predetermined wave-length ultra-violet radiation is sent directly through a transparent original, on said layer or through a substrate of the said sensitive layer.

6. A duplicating process for utilising a product as claimed in claim 3, in which a first predetermined wave-length radiation is sent through an original and one of the said substrates, on the sensitive layer to generate the photo-ionisation of the said dye or dyes, and a second predetermined wave-length radiation is applied directly to the laminated product, without the said original, on the sensitive layer to generate the reaction of the said polymer and then the two substrates are separated from each other, each one with adhesive parts of the sensitive layer.

7. A process as claimed in clam 6, in which ultra-violet range wave-lengths are utilised for the said two radiations, the said second radiation being of such a wave-length that the coloured parts generated by the said first radiation offer a very strong absorption for said second radiation.

8. A duplicating process for utilising a laminated product as claimed in claims 3 and 4, in which the laminated product is placed on an opaque or transparent original document to be duplicated, one first infra-red radiation is sent through the laminated product and onto said original at a such frequency that radiation absorbed by the dark areas of the original are converted into heat which generates the reaction of the said diazo/ coreacting combination whereby the latter becomes opaque at the level of the corresponding areas, the said original is removed, one or several radiations are applied to the laminated product according to predetermined wavelengths which generate the reaction of the said polymer in the parts of the sensitive layer in which the infra-red radiation did not generate a reaction at the level of the diazo/coreacting combination in order to cause the degradation of the diazo/salts of the said combination and the formation of a colour from the said dye, and the said two substrates are separated from each other, each one with adhesive parts of the sensitive layer.

9. An image-duplicating laminated product or material, substantially as hereinbefore described with reference to Figs. 1 to 4 of the accompanying drawings.

10. An image-duplicating laminated product or material, substantially as hereinbefore described with reference to Figs. 5 and 6 of the accompanying drawings.

11. A duplicating process substantially as hereinbefore described with reference to Figs.

1 to 4 of the accompanying drawings.

12. A duplicating process substantially as hereinbefore described with reference to Figs.

5 and 6 of the accompanying drawings.