EP0056226B1 - Two-component diazotype material - Google Patents

Abstract

A two-component diazotype material, composed of a support and a light-sensitive layer which is applied thereto and contains a polymeric binder, a diazonium salt, a coupler, an acid stabilizer and conventional additives, wherein the support is a biaxially oriented polyester film and the polymeric binder comprises a mixture of about 10-60 percent by weight of a polymer or copolymer of vinyl acetate, for example, a copolymer of vinyl acetate and crotonic acid, and about 40-90 percent by weight of a cellulose ester, such as cellulose acetopropionate, cellulose acetobutyrate, cellulose propionate or cellulose butyrate.

Description

The present invention relates to a two-component diazotype material, consisting of a support and a light-sensitive layer applied thereon, which contains polymeric binder, diazonium salt, coupler, acid stabilizer and conventional additives.

It is known that cellulose esters are used as polymeric binders in diazo type materials. Because of their good film-forming and optical properties, their thermal stability and their good compatibility with diazonium salts and couplers, these have proven themselves so well that they are often mentioned and are used almost exclusively in practice. The disadvantage of these compounds, however, is insufficient layer adhesion on polyester films, which is sufficient only with the aid of suitable, additionally applied adhesive layers. Adhesive layers are applied, for example, in a special operation with trichloroacetic acid and silica or polyvinylidene chloride.

It is also known to use polyvinyl acetate as a binder (US-A-2 405 523). Polyvinyl acetate has the advantage that it adheres somewhat better to polyester surfaces. As a thermoplastic, however, polyvinyl acetate has the major disadvantage that the sensitized layers tend to emboss and stick during processing.

It is also known that copolymers of vinyl acetate and maleic acid or crotonic acid are distinguished by useful adhesion on polyester surfaces (DE-B-1065724). These polymers can be applied from an aqueous alkaline solution, but are also easily removed by aqueous alkali. In addition, these layers tend to stick.

It is also known to harden adhesive or lacquer layers from a mixture of vinyl acetate-crotonic acid copolymers and, for example, urea-formaldehyde resins (DE-C-1062111 and DE-B-14 61 260). This reduces their alkali solubility, but not completely eliminated.

On the other hand, the more a lacquer layer is hardened, the more difficult it is to sensitize, since the diazonium salts and couplers penetrate less into the layer during the diffusion process. The degree of hardening of the layer is therefore decisive for its suitability in blueprint layers.

A two-component diazotype material with an anti-slip coating is also known (DE-A-25 02 259), which consists of a biaxially oriented polyester film and a photosensitive layer applied thereon, which contains a polymeric binder, a diazonium salt, a coupler and an acid stabilizer. The layer structure is relatively complicated and does not meet the highest demands on layer adhesion and sensitization.

The object of the invention was to develop light-sensitive layers on polyester films which have excellent adhesion without being prone to sticking or embossing, which are easily sensitized and in which the other blueprint properties are not impaired.

The solution is based on a two-component diazotype material, consisting of a biaxially oriented polyester film as a layer support and a photosensitive layer applied thereon, which contains polymeric binder, diazonium salt, coupler, acid stabilizer and conventional additives, which is characterized in that the polymeric binder consists of a Mixture of 10-60 percent by weight of a polymer or copolymer of vinyl acetate and 40-90 percent by weight of cellulose ester. The copolymer preferably consists of vinyl acetate and crotonic acid, a crotonic acid content of about 4-12 percent by weight being particularly advantageous.

This ensures that the layer adhesion is significantly improved compared to the unblended binders cellulose ester or polyvinyl acetate, without the layers tending to stick or embossing, that the lacquer layer is easily sensitized, and that the good blueprint properties, such as storage life of the unexposed material, the The development speed, transparency and durability of the solid and pause background are retained when storing files.

• Zum einen von Polymerisaten oder Mischpolymerisaten des Vinylacetats, wobei sich solche mit einem Crotonsäuregehalt von 4-12%, entsprechend einer Säurezahl im Bereich von 30-90, ganz besonders bewährt haben. Zum anderen von Celluloseestern, da diese besonders gute Filmbildner sind. Bevorzugt werden Ester der Essigsäure, Propionsäure oder Buttersäure sowie deren Mischester, zum Beispiel Celluloseacetopropionat, Celluloseacetobutyrat oder Cellulosebutyrat.

According to the invention, the polymeric binder is a mixture of at least two substances:

• On the one hand, polymers or copolymers of vinyl acetate, where those with a crotonic acid content of 4-12%, corresponding to an acid number in the range of 30-90, have proven particularly useful. On the other hand, from cellulose esters, since these are particularly good film formers. Esters of acetic acid, propionic acid or butyric acid and their mixed esters, for example cellulose acetopropionate, cellulose acetobutyrate or cellulose butyrate, are preferred.

The polyester films used as carrier material are, for example, those made from polybutylene terephthalate from mixed polyesters, for example made from terephthalic acid, isophthalic acid and ethylene glycol or 1,4-dimethylglycol-cyclohexane, the isophthalic acid content being up to 50 mole percent or from terephthalic acid and ethylene glycol and polyethylene glycol having a molecular weight 1,000 to 10,000 or from naphthalene-2,6-dicarboxylic acid, terephthalic acid and ethylene glycol. However, polyethylene terephthalate has proven particularly useful as a carrier material.

A polyester film to which an adhesive layer is applied to one or both surfaces during production is preferably used as the carrier material for the diazotype material according to the invention. The adhesive layers are generally applied between the first and second orientation steps, as can be seen, for example, from DE-B-16 29 480.

wobei

• R, und/oder R₂ Wasserstoff, Chlor, Methyl, Methoxy, Ethoxy oder Butoxy sein kann und
• X eine Dimethylamino-, Diethylamino-, Dipropylamino-, Morpholino-, Pyrrolidino-, Piperidino-, Alkylmercapto- oder Tolylmercaptogruppe sein kann.

The diazonium compounds that can be used to make the photosensitive layers are any of the many known diazonium salts available. Examples are the diazonium salts derived from the substituted p-phenylenediamine or p-mercaptoaniline, for example

in which

• R, and / or R _{2 can be} hydrogen, chlorine, methyl, methoxy, ethoxy or butoxy and
• X can be a dimethylamino, diethylamino, dipropylamino, morpholino, pyrrolidino, piperidino, alkylmercapto or tolyl mercapto group.

The diazonium salt is stabilized, as is known as the zinc chloride double salt, the cadmium chloride double salt, the tin chloride double salt, the boron fluoride salt, the sulfate salt, the hexafluorophosphate salt or the like.

The coupler substances to be used are also known. The selection is made according to the desired color of the image areas. For example, couplers based on cyanoacetic acid amide, acetoacetic acid amide, phenol and phenol carboxylic acid amide, naphthol, naphtholsulfonic acid amide and naphthocarboxylic acid amide, resorcinol and resorcylic acid derivatives or on the basis of mono-, di-, tri- and tetrahydroxyylene-di- and -triphenylene-can be mentioned, and can also be substituted .

The light-sensitive layer can also contain the known stabilizing agents, such as 5-sulfosalicylic acid, citric acid, maleic acid, tartaric acid, boric acid, but also thiourea. It can also contain pigments such as colloidal silica, finely ground aluminum oxide or silicates.

The following examples serve to explain the invention further, without restricting the scope of the invention thereto.

example 1

• 95 ml Aceton
• 15 ml Methanol und
• 10 ml Methylglykol

werden

• A 10 g Celluloseacetopropionat (3,6% Acetylgruppen, 44,7% Propionylgruppen, 1,8% Hydroxylgruppen; (eine 20%ige Lösung dieses Produktes in Aceton/Ethanol 72:8 besitzt eine Viskosität von etwa 7 Pa - s»
• B 10 g Polyvinylacetat mit dem Molgewicht 1 ·1µε
• C 10 g Copolymerisat aus Vinylacetat und Crotonsäure mit der Säurezahl 35-45 und dem Molgewicht 1 . 105
• D 5 g Copolymerisat aus Vinylacetat und Crotonsäure (wie C)
  • 5g butyliertes Harnsotff-Formaldehydharz
  • 0,2g Sulfosalicylsäure
  • E 7 g Celluloseacetopropionat wie A
  • 3 g Polyvinylacetat wie B
  • F 5 g Celluloseacetopropionat wie A
  • 5 g Polyvinylacetat wie B
  
  gelöst, und die Lacke A-F auf eine 100 µm dicke Folie aus biaxial orientiertem Polyethylenterephthalat, die während der Produktion mit einer Haftschicht aus einer Acryl- bzw. Methacrylmasse versehen worden ist, so beschichtet und dann 5 Minuten bei 70-80 °C getrocknet, dass man Lackfilme mit einem Schichtgewicht von 7-8 g/cm² erhält. Der Lack D wird zur Härtung zusätzlich 5 Minuten bei etwa 150 °C getrocknet.

In a mixture of

• 95 ml acetone
• 15 ml of methanol and
• 10 ml methyl glycol

will

• A 10 g of cellulose acetopropionate (3.6% acetyl groups, 44.7% propionyl groups, 1.8% hydroxyl groups; (a 20% solution of this product in acetone / ethanol 72: 8 has a viscosity of about 7 Pa s »
• B 10 g of polyvinyl acetate with a molecular weight of 1 · 1µε
• C 10 g copolymer of vinyl acetate and crotonic acid with an acid number of 35-45 and a molecular weight of 1. 105
• D 5 g copolymer of vinyl acetate and crotonic acid (as C)
  • 5g butylated urine formaldehyde resin
  • 0.2g sulfosalicylic acid
  • E 7 g of cellulose acetopropionate as A
  • 3 g of polyvinyl acetate as B
  • F 5 g of cellulose acetopropionate as A
  • 5 g of polyvinyl acetate as B
  
  dissolved, and the paints AF on a 100 micron thick film of biaxially oriented polyethylene terephthalate, which has been provided with an adhesive layer made of an acrylic or methacrylic composition during the production, and then dried for 5 minutes at 70-80 ° C that paint films with a layer weight of 7-8 g / cm ^{2 are} obtained. The lacquer D is dried for an additional 5 minutes at about 150 ° C.

• 70 ml Wasser
• 75 ml Ameisensäure
• 1000 mllsopropanol
• 10 g 5-Sulfosalicylsäure
• 10 g Weinsäure
• 2 g Borsäure
• 12,5 g 2-Hydroxynaphthoesäure-N-2'-methylanilid
• 15 g p-Dipropylaminobenzoldiazoniumtetrafluoroborat

The lacquered films are then sensitized by dipping with a solution containing the following components and then drying at 80 ° C:

• 70 ml water
• 75 ml formic acid
• 1000 ml isopropanol
• 10 g 5-sulfosalicylic acid
• 10 g tartaric acid
• 2 g boric acid
• 12.5 g of 2-hydroxynaphthoic acid N-2'-methylanilide
• 15 g p-dipropylaminobenzene diazonium tetrafluoroborate

The dried samples are developed into a full tone in a commercially available blueprint machine between filter paper with moist ammonia at around 75 ° C, since adhesion defects are more visible on full tones. Layers that tend to stick or emboss stick to the paper surface. When the film is removed from the paper, glued or embossed paper fibers remain on the lacquer layer.

To check the layer adhesion on the film base, the layer-bearing film side is scored with a cross-cut tester according to DIN 53 151. Adhesive tape is pressed onto the injured layer and then peeled off suddenly. If the layer adheres well to the film, no part of the layer may remain on the adhesive tape during this test; with medium layer adhesion individual break points are recognizable, with poor layer adhesion the lacquer can be largely removed.

Liability is permanently damaged by storage in a humid atmosphere (96% relative air humidity, storage for 24 hours). A similar deterioration in adhesion can also be observed in the rapid test when stored under water for one hour.

The following table shows the results of the tests:

It can be seen that varnishes E and F have the best adhesion, show no signs of sticking and, in contrast to C and D, are not soluble by wiping with a cotton ball soaked in dilute ammonia (1:10).

Example 2

• 68 ml Aceton
• 12 ml Methanol
• 12 ml Methylglykol
• 8 g Celluloseacetopropionat
• 4 g eines Gemisches aus feinteiliger gefällter Kieselsäure und Aluminiumoxid

werden

• G ohne Zusatz
• H mit 0,9 g (10%) eines Copolymerisates aus Vinylacetat und Crotonsäure (Säurezahl 90)
• I mit 1,5 g (16%) eines Coplymerisates aus Vinylacetat und rctcrsäure (Säurezahl 90)
• K mit 1,5 g (16%) eines Copolymerisates aus Vinylacetat und Crotonsäure (Säurezahl 45)
• L mit 2,5 g (24%) Polyvinylacetat mit dem Mol. Gew.2,6 · 105

nach dem Lösen auf 100 gm dicke Folie aus biaxial orientiertem Polyethylenterephthalat, das während der Produktion mit einer Haftschicht versehen worden ist, beschichtet und 5 Minuten bei 90 °C getrocknet, so dass man Schichtgewichte von 7-8 g/m² erzielt. Anschliessend werden die lackierten Folien mit einer Lösung aus

• 100 ml Wasser
• 900 ml Isopropanol
• 60 ml Ameisensäure
• 30 g 5-Sulfosalicylsäure
• 30 g Resorcin
• 32 g 2,5-Dibutoxy-4-morpholino-benzoldia- zonium-tetrachlorozinkat

bestrichen und getrocknet.Pigmented varnishes on the basis

• 68 ml acetone
• 12 ml of methanol
• 12 ml methyl glycol
• 8 g cellulose acetopropionate
• 4 g of a mixture of finely divided precipitated silica and aluminum oxide

will

• G without addition
• H with 0.9 g (10%) of a copolymer of vinyl acetate and crotonic acid (acid number 90)
• I with 1.5 g (16%) of a copolymer of vinyl acetate and hydrochloric acid (acid number 90)
• K with 1.5 g (16%) of a copolymer of vinyl acetate and crotonic acid (acid number 45)
• L with 2.5 g (24%) polyvinyl acetate with a mol. Weight of 2.6 x 105

after dissolving on 100 gm thick film of biaxially oriented polyethylene terephthalate, which has been provided with an adhesive layer during production, coated and dried for 5 minutes at 90 ° C., so that layer weights of 7-8 g / m ^{2 are} achieved. The lacquered foils are then removed with a solution

• 100 ml water
• 900 ml isopropanol
• 60 ml formic acid
• 30 g of 5-sulfosalicylic acid
• 30 g resorcinol
• 32 g of 2,5-dibutoxy-4-morpholino-benzenediazonium tetrachlorozincate

spread and dried.

The samples are developed in a blueprint machine with warm, moist ammonia and, as described in Example 1, the adhesion is then checked.

The results of the adhesion test are summarized in the following table:

The adhesion results show that the pigmented lacquer layers according to the invention adhere significantly better than the lacquer layer of the comparison sample.

Example 3

• 80 ml Aceton
• 20 ml Methanol

werden

• M 8 g Celluloseacetopropionat (2,5% Acetylgruppen;
• 46 % Propionylgruppen; 2,8% Hydroxylgruppen;
• Viskosität: 20 Sekunden nach ASTM D-817 (Formula A) und D-1343
• N 8 g Copolymeres aus Vinylacetat und 5% Crotonsäure, wie unter G aus Beispiel 1
• 0 8 g Polyvinylacetat mit dem Molekulargewicht 2,6 · 10⁵
• P 4 g Celluloseacetopropionat, wie unter M
• 4 g Copolymeres aus Vinylacetat und Crotonsäure, wie unter N
• Q 4 g Celluloseacetopropionat, wie unter M
• 4 g Polyvinylacetat wie unter 0 gelöst. Anschliessend werden in jedem dieser Ansätze folgende Substanzen aufgelöst:
  • 0,2 g 5-Sulfosalicylsäure
  • 0,2 g 2-Hydroxyphenol-hydroxyethylether
  • 0,4 g Phthalsäure-bis-(methoxyethylester)
  • 0,4 g 2,4- Dihydroxybenzoesäure-ethanolamid
• 0,6 g 4-(p-Tolylmercapto)-2,5-diethoxybenzol- diazonium-tetrafluoroborat

in

• 80 ml acetone
• 20 ml of methanol

will

• M 8 g cellulose acetopropionate (2.5% acetyl groups;
• 46% propionyl groups; 2.8% hydroxyl groups;
• Viscosity: 20 seconds according to ASTM D-817 (Formula A) and D-1343
• N 8 g copolymer of vinyl acetate and 5% crotonic acid, as under G from Example 1
• 0 8 g of polyvinyl acetate with a molecular weight of 2.6 · 10 ⁵
• P 4 g of cellulose acetopropionate as described in M
• 4 g copolymer of vinyl acetate and crotonic acid, as under N
• Q 4 g cellulose acetopropionate as under M
• 4 g of polyvinyl acetate as dissolved under 0. The following substances are then dissolved in each of these approaches:
  • 0.2 g 5-sulfosalicylic acid
  • 0.2 g of 2-hydroxyphenol hydroxyethyl ether
  • 0.4 g of bis (methoxyethyl) phthalate
  • 0.4 g 2,4-dihydroxybenzoic acid ethanolamide
• 0.6 g of 4- (p-tolylmercapto) -2,5-diethoxybenzene diazonium tetrafluoroborate

The solutions are applied with a wet weight of about 100 g / m ² to subbed polyester film and dried at 80 ° C. for 5 minutes. The light-sensitive foils are exposed under an image template and then developed with ammonia. Strong brown-lined copies with a colorless background are obtained.

Liability is determined as in Example 1. The following table shows the results:

The quality of copies P and Q is significantly better. Similar results are obtained if the lacquers M-Q are coated on a polyester film from another manufacturer and dried.

Example 4

• R 3 g Celluloseacetobutyrat (15,3% Acetylgruppen; 37% Butyrylgruppen; 1,5% Hydroxylgruppen, Viskosität: 55 m Pa . s, 15%ig in Aceton bei 25°C)
• S 1,5 g Celluloseacetobutyrat, wie unter R und
• 1,5 g Polyvinylacetat, wie unter 0, Beispiel 3 in 30 ml Methylglykol beschichtet und 5 Minuten bei 120°C getrocknet.

Solutions from. Are placed on a 180 Jlm polyester film

• R 3 g cellulose acetobutyrate (15.3% acetyl groups; 37% butyryl groups; 1.5% hydroxyl groups, viscosity: 55 mPa.s, 15% in acetone at 25 ° C)
• S 1.5 g of cellulose acetobutyrate, as under R and
• 1.5 g of polyvinyl acetate, as coated under 0, Example 3, in 30 ml of methyl glycol and dried at 120 ° C. for 5 minutes.

The films are then sensitized and developed into full blue tones, as described in Example 1. With pattern R, the blue lacquer layer is easily peeled off as skin. In contrast, the pattern S shows a significantly improved adhesion compared to the pattern R.

Claims (6)

1. A two-component diazotype material, composed of a biaxially oriented polyester film serving as a layer support and a light-sensitive layer, which is applied thereto and contains a polymeric binder, a diazonium salt, a coupler, an acid stabilizer and conventional additives, wherein the polymeric binder comprises a mixture of 10-60 per cent by weight of a polymer or copolymer of vinyl acetate and 10-90 per cent by weight of a cellulose ester.

2. A diazotype material as claimed in claim 1, wherein the copolymer comprises vinyl acetate and crotonic acid.

3. A diazotype material as claimed in claim 2, wherein the copolymer of vinyl acetate and crotonic acid contains about 4-12 per cent by weight of crotonic acid.

4. A diazotype material as claimed in claim 1, wherein the cellulose ester is a cellulose aceto- propionate, cellulose acetobutyrate, cellulose propionate or cellulose butyrate.

5. A diazotype material as claimed in claim 1, wherein the support is a polyethylene terephthalate film.

6. A diazotype material as claimed in claims 1 and 5, wherein an adhesive layer has been applied to one or both surfaces of the polyester film during manufacture.