Photopolymerizable Compounds and Compositions Comprising the Product of the Reaction of a Monocarboxy-Substituted Benzophenone With a Resin

A. A benzoylbenzoic acid-modified polyamide resin was prepared by heating 205.1 parts of dimer fatty acids with 68.1 parts of o-benzoylbenzoic acid (o-BBA) at 140.degree. C. 31.5 Parts of ethylene diamine was dropped into the mixture slowly, maintaining the exotherm by cooling at about 140.degree.-150.degree. C. After the addition of the dimer was complete, the resulting polymeric salt was dehydrated slowly by heating it to 200.degree. C. The product was an amber-colored thermoplastic resin melting at 92.degree. C. It was soluble in lower alcohols and was compatible with nitrocellulose.

B. A thin film of an alcohol solution of the polyamide of part (A) above was exposed to ultraviolet light and crosslinked to an insoluble adhesive coating in 3 seconds.

A. A non-drying alkyd resin was prepared by reacting the following ingredients at 200.degree.-230.degree. C. in 6% xylene as azeotrope over a period of 10 hours: 175 parts of pelargonic acid, 50 parts of o-benzoylbenzoic acid, 137 parts of phthalic anhydride, 2 parts of fumaric acid, and 135 parts of pentaerythritol. The product has an acid value of 5.5 and its viscosity in xylene was about 6-9 poises at 50%.

B. A 65/35 mixture of the alkyd resin of part (A) and an isocyanate-modified pentaerythrotol triacrylate(prepared by the process disclosed in U.S. Pat. No. 3,759,809, which issued on Sept. 18, 1973.) was coated onto tin-free steel and exposed to a 100-watt/inch ultraviolet lamp. A high quality crosslinked film was obtained in about 2.5 seconds.

A benzoylbenzoic acid-modified unsaturated polyester resin was prepared by heating to 390.degree. F. under nitrogen the following ingredients: 73.5 parts of maleic anhydride, 137.9 parts of propylene glycol, 103.6 parts of phthalic anhydride, 90.8 parts of o-benzoylbenzoic acid, and 0.02 parts of hydroquinone. The reaction was continued at 385.degree.-395.degree. F. until the product has an acid value of 40-45 and a viscosity of 11 at 70% in styrene. The batch was then cooled to 290.degree. F. and dropped into 186 parts of styrene monomer. The product contained 70% solids and had a Gardner viscosity of 11-15 poises. It dried in 2 seconds when exposed to ultraviolet light.

A benzoylbenzoic acid rosin-modified phenolic resin was prepared by heating 800 parts of WW rosin and 200 parts of o-benzoylbenzoic acid at 480.degree. F. 200 Parts of liquid phenolformaldehyde resin was added slowly. At the completion of the addition, 105 parts of 95% glycerin was added and the mass heated slowly to 520.degree. F. where it was held until an acid value of 14-20 was reached (about 4-6 hours).

The product was hard amber-colored resin melting at 310.degree.-320.degree. F. It was soluble in petroleum solvents and drying oils. Upon exposure to ultraviolet radiation the product dried in 3 seconds.

A. A benzoylbenzoic acid-polyurethane ester was prepared as follows: 30 parts of xylene, 425 parts of dipropylene glycol, and 120 parts of trimethylolethane were charged to a 3-liter resin flask equipped with a thermometer, stirrer, inert gas inlet tube, and heating mantle set up for Dean-Stark decantation of water of esterification. The mixture was heated to 75.degree. C., and then 454 parts of o-benzoylbenzoic acid was added. Heating was continued under blanket of nitrogen to 150.degree. C. until esterification commenced. After 5 hours the reaction temperature rose to 217.degree. C. and 35.5 grams of water of reaction hand been collected.

The acid value of the product was 3.8 mg KOH per gram of resin. At 200.degree. C. and 20mm Hg vacuum the residual xylene was stripped from the reaction mixture.

The temperature of the reaction was lowered to 110.degree. C., and 253 parts of an 80/20 mixture of the 2,4- and 2,6-isomers of toluene diisocyanate was added over a 1-hour period via a dropping funnel in order to maintain the exotherm temperature below 150.degree. C. When all of the toluene diisocyanate had been added, the viscous reaction mixture was held at 150.degree. C. until all free NCO was consumed as monitored by an infrared scan of a sample of the product at 4.45 .mu..

The product, a pale amber o-BBA-polyurethane ester, was discharged at 75.degree.-100.degree. C. It had a melting point in the range of 45.degree.-54.degree. C. as measured by the Durran mercury method. The resin was freely soluble in aromatic hydrocarbons, ketones, and esters.

B. A solution of 30 parts of the product of part (A) above in 70 parts of pentaerythritol tetraacrylate was applied in a thin film to corona-treated polyethylene film and laminated to vinylidene chloride-coated cellophane. The sample was exposed to a 200-watt/inch ultraviolet lamp for 0.2 second, causing complete cure of the adhesive and providing a laminate having excellent peel strength.

A benzophenone tetracarboxylic dianhydride (BTDA)-modified polyester was prepared by heating to 170.degree. C. under nitrogen the following ingredients: 161 parts of BTDA, 200.4 parts of tridecanol, 256 parts of pelargonic acid, 137 parts of phthalic anhydride, and 29.6 parts of toluene. The reaction was continued at 207.degree.-215.degree. C. until the product had an acid value of 10.8 (about 12 hours). The product was an amber colored soft resin.

A BTDA-modified polyester was prepared by heating to 240.degree. C. under nitrogen the following ingredients: 724 parts of a 2:1 mixture of BTDA and tridecanol, 107 parts of dipropylene glycol, 41.4 parts of trimethylolethane, and 20 parts of pelargonic acid. The reaction was continued until the product had an acid value of 13.5 (about 8 hours). The product was an amber colored, soft, tacky resin.

A BTDA-modified alkyd/polyester was prepared by heating to 220.degree. C. under nitrogen the following ingredients: 161.5 parts of a 2:1 mixture of BTDA and tridecanol, 451 parts of dehydrated castor oil, 137 parts of trimethylolethane, and 29.6 parts of phthalic anhydride. Water of esterification was collected, and the reaction terminated when the product had an acid number of 9.2. The product was a dark amber, soft resin.

The procedures of Examples 1-8 were repeated with each of the following instead of o-BBA or BTDA: o-(p-chlorobenzoyl) benzoic acid, o-(p-dimethylaminobenzyl) benzoic acid, 2,2'-benzophenone dicarboxylic acid, benzophenone tetracarboxylic acid, benzophenone hexacarboxylic dianhydride, diethylaminobenzophenone tetracarboxylic acid, and N,N'-dibutylaminobenzophenone tetracarboxylic acid. The results were comparable.

Several of the products of this invention were formulated into inks and tested as follows:

A. A mixture of 23 parts of o-BBA-modified oil-free alkyd resin, 59 parts of isocyanate-modified pentaerythritol triacylate, 15 parts of phthalocyanone blue, and 3 parts of 4,4'-bis (dimethylamino)benzophenone was printed onto clay-coated sulfite board by web offset and was dried by passing it at the rate of 550 feet per minute on a sheet-fed lithographic press equipped with 2 reflectorized 200-watt/inch mercury vapor lamps.

B. A mixture of 50 parts of o-BBA-modified linseed oil-alkyd resin, 30 parts of isocyanate-modified pentaerythritol triacrylate, 15 parts of phthalocyanine blue, and 5 parts of 4,4'-bis (dimethylamino) benzophenone was printed onto clay-coated sulfite board and dried by passing it at the rate of 600 feet per minute on the equipment of part (A) above.

C. A mixture of 85 parts of o-BBA-polyurethane ester and 15 parts of phthalocyanine blue was printed onto coated paper by letterpress and dried by passing it under three 200-watt/inch mercury vapor lamps at the rate of 1200 feet per minute.

D. A mixture of 68 parts of o-BBA-rosin-modified phenolic resin, 15 parts of phthalocyanine blue, and 17 parts of Michler's ketone was printed by web offset onto 32-pound coated paper. The ink was dried by passing it under three 200-watt/inch mercury vapor lamps at a rate of 800 feet per minute.

E. A mixture of 90 parts of a BTDA-modified polyester prepared by the process of Example 6 and 10 parts of phthalocyanine blue was printed onto coated paper by letterpress and dried by passing it under three 200-watt/inch mercury vapor lamps at the rate of 1200 feet per minute.

F. The procedure of part (E) was repeated with each of the products of examples 7, 8, and 9 instead of the BTDA-modified polyester. The results were comparable.

G. The procedures of parts (A), (B) and (d) were repeated with each of the following photoinitiators instead of 4,4'-bis (dimethylamino) benzophenone (or Michler's ketone): benzoin methyl ether, acetophenonebenzil, and hexachlorobenzene. The results were comparable.

In each case the sheets were set off free without the use of spray powders and were scratch resistant.

The products of Examples 1 (A) and 2-9 were applied by offset gravure at film weights ranging from 0.5 to 3.0 pounds per ream to each of these substrates: Saran-coated cellophane, polyethylene surface-treated with corona discharge, polyvinylidene dichloride-coated polypropylene, and Mylar. Laminations were made at 150.degree. F. and 50 pounds/inch pressure between cellophane and cellophane, cellophane and polyethylene, cellophane and polypropylene, and polypropylene and Mylar, and then cured by exposing them at the rate of 50 feet per minute at a distance of 1 inch from a 1200-watt/inch ultraviolet lamp. The laminations were successful as evidenced by tear seals having bond strengths of at least 300 grams per inch.

The procedures of Example 10 (parts A-G) were repeated with each of the following colorants instead of phthalocyanine blue: benzidine yellow, lithol rubine red, carbon black, milori blue, and phthalocyanine green. The results were comparable.

The procedures of Examples 1 (B), 2 (B), 3, 4, 5 (B), and 6-11 were repeated except that instead of being exposed to ultraviolet light the samples were passed on a conveyor belt beneath the beam of a Dynacote 300,000-volt linear electron accelerator at a speed and beam current so regulated as to produce a dose rate of 0.5 megarad.

These systems produced resinous materials of varying degrees of hardness in films from 0.5 to 20 mils thick having tacky surfaces.

The procedures of Examples 1 (B), 2 (B), 3, 4, 5 (B), and 6-11 were repeated except that instead of being exposed to ultraviolet light the samples were exposed to a combination of ultraviolet light and electron beam radiation in a variety of arrangements: ultraviolet light, then electron beam; electron beam, then ultraviolet light;

ultraviolet light before and after electron beam; electron beam before and after ultraviolet radiation; and simultaneous electron beam and ultraviolet light radiation. The results were comparable.