GB2093041A - Quaternised vinylimidazole polymers - Google Patents

Abstract

The invention provides a polymer, useful as a mordant for dyes in photographic colour diffusion transfer processes, containing repeating units of polymerised 1-vinylimidazole and/or a 2-alkyl-1-vinylimidazole which repeating units have been partially quaternised with 1-chloromethyl-carbonyloxy-2,3- dihydroxypropane. Preferably, the polymer contains additional repeating units which raise the Tg of the polymer e.g. units derived from methyl methacrylate, styrene a N-(2-hydroxypropyl) methacrylamide. Suitable starting copolymers are prepared in Examples. Example 1 describes the preparation of 1-chloromethyl-carbonyloxy- 2,3-dihydroxypropane.

Description

SPECIFICATION Vinylimidazole polymers This invention relates to polymers, in particular to polymers containing units derived from a vinylimidazole. Such polymers can be of use as mordants for dyes in photographic colour diffusion transfer processes.

It has been known for some time that mordants based on poly.(1-vinylimidazole) and partially quaternised with chloroethanol are suitable for use in colour image transfer processes. They do however suffer from a number of disadvantages. Because of their susceptability to moisture uptake, dyes mordanted to these materials tend to become less firmly attached to the mordant at high temperature and at high humidity. This is a phenomenon known as 'smear'.

According to the present invention there is provided a polymer containing repeating units of polymerised 1-vinylimidazole and/or a 2-alkyl-1-vinylimidazole which repeating units have been at least partially quaternised with 1 -chloromethyl-carbonyloxy-2, 3-d ihydroxypropane (otherwise described as chloroacetyl glycerine).

Preferably, at least 10% of said units in the polymer are quaternised more preferably 20% to 50% of said units are quaternised.

A polymer of the invention may be initially a homopolymer of 1-vinylimidazole or a 2alkylvinylimidazole or may be initially a copolymer thereof. In the case of copolymers the comonomer is preferably one which raises the Tg of the polymer, for example an alkyl methacrylate in which the alkyl group contains from 1 to 4 carbon atoms, preferably 1. Specific examples of comonomers are methyl methacrylate, styrene and N-(2-hydroxypropyl)methacrylamide.

The molar ratio of comonomer to the vinylimidazole monomer may be for example from 1:1 to 1.5:1.

The viscosity of the quaternised polymer may be for example, in terms of log viscosity number, as given in any of the Examples below.

The polymers of the invention are water-soluble and a layer thereof may be formed by coating a a solution of the polymer on a support and drying. The solution may contain a binder, e.g.

gelatin. The solution may also contain ingredients desired for the functioning of the layer as a dye image-receiver in a colour image transfer process such as hardeners, developing agents and surfactants.

The following Examples 2, 3, 4, 6, 9, 10, 11 and 13 to 15 describe preparations of specific polymers of the invention by way of example and Examples 16 to 20 describe the production and use of dye image-receiving materials containing a polymer of the invention as a mordant in accordance with the invention by way of example. In the Examples:~ A.l.B.N. = azobis(butyronitrile) CIT = colour image transfer EDTA = ethylenediaminetetracetic acid, and ESTAR is a registered trade mark.

Example 1: The Preparation of 1 -Chloromethylcarbonyloxy-2, 3-dihydroxypropane Glycerol was reacted with acetone in the presence of p-toluene-sulphonic acid to give isopropylidene glycerol as described by Newman and Renoll (J. Am. Chem. Soc. 67, 1621 (1945). The compound was a clear colourless liquid, boiling at 101 or. under a water pump vacuum.

This compound was reacted with chloroacetyl chloride in the presence of pyridine and the chloroacetylated isopropylidene glycerol was treated with p-toluene sulphonic acid in aqueous suspension as described by Arpino and Jacini (Fette, Seife, Anstrichmittel, 60, 1 1958) to give the chloroacetylated glycerine. The product was purified by high vacuum distillation. b.p.

148-154'C/0.1 mm.

C5H9CI04 Require: C,35.61; H,5.34; Cl,21.07% Found: C,35.27; H,5.49; Cl,20.23% Example 2: Reaction of poly(styren e)-co-( I -vinylimidazole) with chloroacetyl glycerine The polymer used in this example was a 48.4:51.6 mole % copolymer of styrene and Nvinylimidazole.

Enough quaternising agent was added to quaternise 20% of the available tertiary nitrogen.

The polymer (9,9g) was dissolved in ethanol (100 ml) in a 250 ml. round bottomed flask, fitted with a magnetic stirrer and a condenser. The apparatus was placed in a thermostated oil bath set at 80 C. Chloroacetyl glycerine (1.70 g) was added and the solution was heated overnight. The polymer was isolated by precipitation of the solution into ethyl acetate (2+1). The polymer was washed with fresh ethyl acetate, and dried under vacuum. It had a log. viscosity number of 42 ml/g in ethanol at 25 C.

[ C8gH79N1004Cl1n Require : Cl,3.09; N, 12.21% Found : Cm,3.55; N,12.59% Example 3: Reaction of Poly-(N-vinylimidazole) with chloroacetyl glycerine (20% quaternisation) Poly-(N-vinylimidazole) (9.4 g) was dissolved in ethanol (100 ml) in a 250 ml round bottomed flask fitted with a magnetic stirrer and a condenser. Chloroacetyl glycerine (3.36 g) was added and the solution was heated in a thermostated oil bath, set at 50'C, overnight. The polymer was isolated as in Example 2 by precipitation into ethyl acetate, washing with this solvent and drying under vacuum. It had a log viscosity number of 20 ml/g. (1% in ethanol at 25 C).

[ C30H39N1004Cl ] n Require: Cl,5.56; N,21.92% Found: Cm,4.70; N,19.13% Example 4: Reaction of Poly-(N-vinylimidazole) and chloroacetyl glycerine (25% substitution) The method of preparation used was the same as that described in Example 3 except that the following charge was used: Poly-(N-vinylimidazole) (9.4 g) Ethanol (100 ml) Chloroacetyl glycerine (4.2 g) The polymer was isolated as described above.

(C25H33H8O4Cl ] Require: Cl,6.52; N,20.56% Found: Cm,5.74; N,20.88% Example 5: PolyjN-(2-h ydroxyprop yl)methacryla m idej-co-(N-vin ylim idazole) N-(2-hydroxypropyl)methacrylamide (14.3 g) and N-vinylimidazole (9.4 g) were dissolved in deaerated water (50 ml) and isopropanol (15 ml) in a 100 ml three necked round bottom flask, fitted with a stirrer, a nitrogen inlet and a condenser. The apparatus was placed in a thermostated oil bath set at 70 C.

AIBN (0.19 g) was added and the solution was heated in a nitrogen atmosphere for 18 hours.

The viscous solution was diluted with water (100 ml) and isopropanol (30 ml) and the polymer was isolated from the solution by precipitation into acetone (21). The polymer was washed with acetone and dried under vacuum. The polymer had a log. viscosity number of 87 ml/g (1% in ethanol and 25 C.).

[ C12H19N302j Require: N,17.72% Found: N, 16.9% NMR gives a monomer ratio of 1:1.05 hydroxypropylmethacrylamide to vinylimidazole.

Example 6: Reaction between the polymer of Example 5 and chloroacetyl glycerine (25% quaternisation) The reaction was carried out as described in Example 2. The following charge was used: Polymer of Example 5: 7.9 g Chloroacetyl glycerine 1.4 g Ethanol 100 ml (Q3H85N12012Cl ] # Require: Cl,3. 18; N,15.05% Found: Cl,3.86; N,14.31% Example 7: Poly(methyl methacrylate)-co-(N-vinylimidazole) Mole ratio 1:1 Distilled N-vinylimidazole (37.6 g), methyl methacrylate (10 g), ethanol (100 ml), acetone (33 ml) and AIBN (0.211 g) were placed in a three necked round bottomed flask, fitted with a magnetic stirrer, reflux condenser and nitrogen bubbler. The flask was placed in a thermostated oil bath set at 85 C. and the mixture was heated under reflux for 18 hours in a nitrogen atmosphere. The viscous solution was allowed to cool and the polymer was isolated from the solution by precipitation into water. The polymer was washed with water, filtered and dried under vacuum. It has a log. viscosity number of 45 ml/g. (1% in ethanol/acetone 3:1 at 25 C).

[ C10H14N20J Require: N, 14.43% Found: N, 14.08% The structure was confirmed by NMR analysis.

Example 8: Poly(methyl methacrylate)-co-(N-vinylimidazole) Mole ratio 1.5:1 The preparation was carried out as for Example 7 except that the following charge was used.

N-vinylimidazole 1 8.8 g Methyl methacrylate 20 g Ethanol 100 ml Acetone 33 ml AIBN 0. 149 The polymer had a log viscosity number of 31 ml/g (1% in ethanol/acetone 3:1 at 25 C.).

[ C2sH36N40jn Require: N,9.52% Found: N,10.98% Example 9: Quaternisation of poly(methyl m ethacrylate)-co-(N-vin ylimidazole), [ Example 7 ] with chloroacetyl glycerine. (50% quaternisation) The polymer (Example 7; 9.7 g) was dissolved in ethanol (50 ml) in a round bottom flask, fitted with a magnetic stirrer and a reflux condenser. The apparatus was placed in a thermostated oil bath set at 90 C. and a solution of chloroacetyl glycerine (4.2 g) in ethanol (50 ml) was added. The solution was heated to reflux overnight. the polymer was isolated by precipitation from the solution into ethyl acetate. The polymer had a log viscosity number of 66 ml/g (1% in ethanol/acetone 3:1 at 25 C.).

(C25H37N408Clj Require: Cl,6.40; N,10.08% Found: Cl,5.67; N,9.92% N.M.R. spectroscopy gave 46% quaternisation.

Example 10: Quaternisation of poly-(methyl methacrylate)-co-(N-vinylimidazole), (Example 7) with chloroacetyl glycerine, (20% quaternisation) The method of Example 9 was followed, but using chloroacetyl glycerine (1.7 g) only. The polymer was isolated as described above. The polymer had a log viscosity number of 59 ml/g (1% in ethanol/acetone 3:1 at 25 C.).

[ C55H7gN10014Cl ] n Require: Cm,3.10; N, 12.23% Found: Cl,3.17; N,11.25% N.M.R. spectroscopy analysis showed 26% quaternisation.

Example 11: Quaternisation of poly(methyl methacrylate)-co-(N-vinylimidazole) (Example 8) with chloroacetyl glycerine (50% quaternisation The method of Example was employed but using chloroacetyl glycerine (3.5 g).

The polymer was isolated as described above, and it had a log viscosity number of 56 ml/g (1% in ethanol/acetone 3:1 at 15"C.).

[ C30H45N4010Cl ] n Require: Cl,5.41; N,8.53% Found: Cl,5.24; N,8.07% N.M.R. analysis showed 47% quaternisation.

Example 12: Poly-(methyl methacrylate)-co-(2-methyl4-vinylimidazole), (Molar ratio 1: 1) Methyl methacrylate (20 g), 2-methyl-l-vinylimidazole (21.6 g), ethanol (225 ml) and acetone (75 ml) were plac#ed in a 500 ml, three necked round bottomed flask, fitted with a nitrogen inlet tube, stirrer, condenser and dropping funnel. The apparatus was placed in a thermostated oil beth set at 70 C, stirring and continuous purgeing with nitrogen was started. AIBN (0.21 g) was added. After heating for one hour, 2-methyl-l-vinylimidazole (21.6 g) was added dropwise from the dropping funnel over one hour. Polymerisation was then continued for 18 hours. The polymer was isolated from the solution by precipitation into water. It was separated from the solvent by centrifugation. The polymer cake was then freeze dried.It had a log viscosity number of 66 ml/g (1% in ethanol, acetone 3:1 at 25 C.).

[ C11H16N202j# Require: N,13.46% Found: N,12.22% N.M.R. spectroscopy confirmed the molar ratio of monomers as 1:1.

Example 13: Quaternisation of Poly-(methyl methacrylate)-co-(2-methyl- 1-vinylimidazole (example 12) with chloroacetyl glycerine (50% quaternisation) The method of Example 9 was employed but the following charge was used: Polymer, Example 12 10.4 g Chloroacetyl glycerine 4.2 g Ethanol 100 ml Isolation of the polymer was carried out as before (Example 9). The polymer had a log viscosity number of 98 ml/g. (1% in ethanol at 25'C.).

[ C27K41 N408Cl ] # Require: Cl,6.07; N,9.58% Found: Cl,5.19; N,9.37% Example 14: Quaternisation of Poly- [ methyl methacrylate-co-(2-methyl4-vin ylimidazole), (Example 12) with chloroacetyl glycerine, 25% quaternisation The reaction was carried out as described in Example 9 using the following charge: Polymer, (Example 1 2) 10.4 g Chloroacetyl glycerine 2.1 g Ethanol 100 ml #C49H73N8012CI ] Require: Cl,3.55; N,11.19% Found: C1,3.60; N,10.29% Example 15: Quaternisation of Poly-(methyl methacrylate)-co-(2-methyl-1-imidazole) with chloroacetyl glycerine, Complete quaternisation The method used was that of Example 9.

Polymer (Example 1 2) 10.4 g Chloroacetyl glycerine 8.45 g Ethanol 100 ml The polymer solution was worked up as described above. The polymer had a log viscosity number of 114 ml/g (1% in ethanol at 25 C.).

[ C16H2sN206Cl ] n Require: Cl,9.43; N,7.44% Found: Cl,6.39; N,7.57% Example 16 The quaternised co-polymeric mordant described in Example 12 was coated in the CIT (colour image transfer) receiver format shown in diagram 1 a. The coating melt was adjusted to pH 5.5.

After holding the coating overnight at 35 C to ensure adequate hardening sample strips were laminated to wedge exposed donor strips in a conventional CIT process. Digram 1 b shows the structure of the donor coating. Lamination was effected by passing donor and receiver in register through a pair of nip rollers after soaking the donor for 1 5s in an activator solution.The composition of thr activator solution was: KOH: 42 g/l KBr 20 g/l 5-Methylbenzotriazole 5 g/l Benzyl alcohol: 5 ml/l ll-Aminoundecanoic acid 5 g/l EDTA, tetrasodium salt: 33 g/l Diagram 1 a) Receiver Structure Mordant (2.15) Gelatin B (2.15) Dev (0.27) Hardener A (0.11) Hardener B (0.11) Surfactant A (0.54) SUPPORT b) Donor Structure RDR (0.67) Gelatin A (3.77) Surfactant B (0.086) Hardener C (0.027) AgX (0.86) Gelatin A (1.08) Surfactant B (0.021) Hardener C (0.01 3) SUPPORT Numbers is parentheses refer to the coating weight of each constituent in g.m In the above coating structures: : Mordant = the test polymer Gelatin B = deionised, acid-processed pig skin gelatin Dev. = 4-methyl-4-hydroxymethyl- 1 -phenyl-3- pyrazolidone Hardener A = Formaldehyde Hardener B = 'Araldite' diluent DX022, active component butanediol diglycidyl ether Surfactant A = nonylphenoxypolyglycidol RDR = magenta dye releaser of structure I Gelatin A = alkali processed bone gelatin Surfactant B = Di-isopropylnaphthalenesulphonic acid Hardener C = bis(vinylsulphonylmethyl)ether AgX = undyed silver halide photographic emulsion, 88% Biro, 12% cre Support = ESTAR transparent support (ESTAR is a registered trade mark).

A check receiver coating, prepared in the same way as the test coating (diagram 1a) but utilising partially (~10%) chloroethanol quaternised poly(1-vinylimidazole) as the mordant, was also processed with the same donor coating. The resultant transferred images were washed 10 mins. in running cold water and the compared for sensitometry, dye hue, image stability (light and dark fade) and 'smear'.

The sensitometry parameters recorded are Dmax, Dmin and toe speed (measured 0.2 density units above fog) and dye hue is defined by A max (wavelength of maximum absorption) half band width (HBW, the width of the absorption band at half the peak density) and -Ai, the wavelength corresponding to the mid point of the HBW line. Light fade was determined using a high intensity FTF and dark oven stability was measured by incubating samples at 49 C. 75% RH for 7 days. 'Smear' was monitored by measuring the loss in resolution of Cobb Chart images when held for 3 days at 60 C. 75% RH. The higher the 'smear number' the greater the smear (Note that 'smear number' is obtained from measurements of the number of Cobb Chart patches that can be resolved before and after incubation.Four determinations are made for each coating and the mean loss, multiplied by 4 to eliminate fractional numbers, is the 'smear number').

The results for the test and check mordant coatings are presented in Table 1.

Fluorescent Tube Fader.

Table 1 60 hr.

fade Sensitometry Hue (nm) (with Dark UV Oven Smear Mordant Dmax Dmin Speed Amax HBW -A filter) Fade No.

2 1.57 0.19 193 554 89 548 3.4% 1.7% 1 Check 1.47 0.19 188 548 95 544 2.5% 3.1% 9 The test polymer is superior to the check in all respects, excepting light fade, where the check shows a small advantage.

Example 17 In the same way as indicated for polymer 2 in Example 16, the mordant polymer described in Examples 3, 4 and 6 were evaluated. Table 2 shows the results: Table 2 60 hr.

fade Sensitometry Hue (nm) (with Dark UV Oven Smear Mordant Dmax Dmin Speed Amax HBW Ai filter) Fade No 3 1.01 0.16 201 549 100 543 1.9% 2.0% 3 4 1.46 0.17 217 549 99 5441.4% 2.1% 6 6 0.72 0.11 183 549 100 543 2.6% 1.4% 4 Check 1.49 0.21 214 549 99 542 1.3% 1.9% 15 Test mordant 4 behaved very similarly to the check but showed much greater resistance to smear. The lower quaternisation level of test mordant 3 (relative to test mordant 4) apparently resulted in a loss in dye density and the co-polymeric test mordant 6 behaved particularly poorly in this respect.

Example 18 Evaluation of the polymers detailed in Examples 9, 10 and 11 was carried out in the same manner as described in Example 16. Table 3 shows the results obtained.

Table 3 60 hr.

fade Sensitometry Hue (nm) (with Dark UV Oven Smear Mordant Dmax Dmin Speed Amax HBW A filter) Fade No.

9 2.25 0.29 223 548 96 546 2.1% + 0.6 4 10 2.23 0.19 212 548 96 546 1.5% +0.64 11 2.65 0.23 217 549 95 545 2.8% +11 2 Check 2.32 0.28 206 549 98 547 2.1% 1.8 7 All the test mordants show good sensitometry and dye stability with a modest improvement in smear relative to the check.

Example 19 The test mordants described in Examples 12 and 14 were also evaluated via the technique set out in Example 16 with the modification that DEV. was omitted from the reveiver coating format (diagram 1 a) and included in the activator solution (1 g/l). The results shows in Table 4 were obtained.

Table 4 60 hr.

fade Sensitometry Hue (nm) (with Dark UV Oven Smear Mordant Dmax Dmin Speed Amax HBW Ai filter) Fade No.

14 0.80 0.17 204 553 89 547 2.4% - +2 13 0.82 0.20 201 551 91 546 2.3% - 0 Check 0.87 0.13 202 549 94 545 2.2% 9 9 The test and check mordants are very similar sensitometrically and confer similar light stability to the dye. The dye absorption band on the test polymers is slightly bathochromic of the control and also slightly sharper. Excellent smear properties are displayed by the test polymers.

Example 20 The evaluation method of Example 16 was used to investigate the test polymer described in Example 15 and the results obtained are collected in Table 5.

Table 5 60 hr.

fade Sensitometry Hue (nm) (with Dark UV Oven Smear Mordant Dmax Dmin Speed Amax HBW A filter) Fade No.

1 15 1.40 0.17 202 548 94 544 1.3% 3.0% 3 Check 1.32 0.18 198 548 95 543 0.8% 7.3% 10 The only major difference between the test mordant and the check is the much better smear result for the test.

Claims (10)

1. A polymer containing repeating units of polymerised 1-vinylimidazole and/or a 2-alkyl-1 vinylimidazole which repeating units have been partially quaternised with 1 -chloromethyl-1 - carbonyloxy-2,3-dihydroxypropane.

2. A polymer according to claim 1 wherein from 10% to 50% of said units have been quaternised with said 1 -chloromethyl-carbonyloxy-2, 3-dihydroxy-propane.

3. A polymer according to claim 1 or 2 which contains additional repeating units derived from a monomer which units increase the Tg of the polymer.

4. A polymer according to claim 1 or 2 which contains additional repeating units derived from an alkyl methacrylate in which the alkyl group contains from 1 to 4 carbon atoms.

5. A polymer according to claim 1 or 2 which contains additional repeating units derived from styrene or N-(2-hydroxypropyl) methacrylamide.

6. A polymer according to claim 3, 4 or 5 in which the molar ratio of additional repeating units to said 1-vinylimidazole and/or 2-alkyl-1-vinylimidazole repeating units (unquaternised and quaternised) is from 1:1 to 1.5:1.

7. A polymer according to claim 1 which has been prepared substantially in accordance with any Example selected from Examples 2, 3, 4, 6, 9, 10, 11, 13, 14 or 15.

8. A material comprising a support and a layer containing a polymer as defined in any of the preceding claims.

9. A material according to claim 8 which is a dye image-receiving material useful in a colour diffusion transfer process.

10. A material according to claim 9 which carries a dye image.