Abstract: A method of forming an image on a substrate by irradiation thereof, wherein the substrate comprises therein or thereon a co-crystal of a polymerisable unsaturated monomer and a spacing component, wherein the co-crystal is capable of undergoing a radiation-activated colour change reaction. A co-crystal of a diacetylene and a spacing component, whereby the reactivity of the diacetylene is reduced is also provided, together with a surface coating composition comprising this co-crystal.

Abstract: The invention relates to a method of marking a substrate comprising treating the substrate with a boron compound and a charrable agent, and, irradiating the areas of the substrate to be marked such that those areas change colour. Marked substrates obtainable by this method are also provided.

Abstract: A textile comprising a diacetylene compound which is capable of changing colour when irradiated with light energy. Methods of imparting colour to textiles comprising irradiating the textile with light energy are also provided.

Abstract: A method of manufacturing a paper substrate comprising a colour former which is capable undergoing a light activated colour change reaction, wherein the colour former is applied to the paper substrate during the manufacture of said paper substrate, and the colour former is a metal oxyanion or a molecular organic. A paper substrate obtainable by this method is also provided.

Abstract: The invention relates to a method of storing information in or on an article, wherein the article comprises a colour former which is selectively irradiated to produce a multi-coloured code comprising at least three different colours. Also provided by the invention is an article comprising a multi-coloured code comprising at least three different colours, obtainable by the method of the invention.

Abstract: A composition susceptible to changing colour upon the application of energy, wherein the composition comprises a colour former and a tinting colourant, wherein the tinting colourant has a complementary colour to that of the composition comprising the colour former without tinting colourant. Preferably, the composition 5 also comprises an energy absorbing additive. The invention also provides a method of improving contrast when a composition susceptible to changing colour is imaged.

Abstract: A method of forming an invisible indicium on an article that comprises an outer opaque layer and an inner, laser-imageable layer, which comprises (5) irradiating the article with a laser, whereby the laser radiation passes through the opaque layer, and causes the laser-imageable layer to change colour. The article can be scanned, as a security check.

Abstract: A composition comprising i) a colour forming component which is susceptible to changing colour when irradiated; ii) an amine neutralised alkylaromatic sulphonic acid; and iii) a binder. Methods of marking a substrate comprising incorporating within or applying to a substrate the composition of this invention, and substrates coated with the composition, are also provided.

Abstract: A data storage medium comprising recording information in the form of a track of data points, the colour of each data point being selected from at least three different colours, wherein the recording information is disposed on a substrate which comprises a colour forming composition, wherein said colour forming comprises a colour former which is susceptible to changing to at least three different colours when irradiated with a laser, wherein the colour former is a leuco dye, a diacetylene or a carbazole. Methods of forming the data storage medium and methods of reading the medium are also provided.

Abstract: A polymer additive for improving the reheat characteristics of a polymer or polymeric composition comprises an inorganic material which is such that a 2.5 mm thick polyethylene terephthalate plaque incorporating the inorganic material has, when tested, an absorption ratio of less than 0.9, wherein the absorption ratio is either the ratio of A1/A2 or the ratio A1/A3, wherein: A1 is the maximum absorption between 400 nm and 550 nm; A2 is the maximum absorption between 700 to 1100 nm; A3 is the maximum absorption between 700 to 1600 nm. Preferred inorganic materials are titanium nitride, indium tin oxide and lanthanum hexaboride.

Abstract: A polymer additive for improving the reheat characteristics of a polymer or polymeric composition comprises an inorganic material which is such that a 2.5 mm thick polyethylene terephthalate plaque incorporating the inorganic material has, when tested, an absorption ratio of less than 0.9, wherein the absorption ratio is either the ratio of A1/A2 or the ratio A1/A3, wherein: A1 is the maximum absorption between 400 nm and 550 nm; A2 is the maximum absorption between 700 to 1100 nm; A3 is the maximum absorption between 700 to 1600 nm. Preferred inorganic materials are titanium nitride, indium tin oxide and lanthanum hexaboride.

Abstract: A method for freezing a food product comprising the steps of: (a) contacting the food product with a freezing surface, the freezing surface having a temperature of from ?10° C. to ?50° C.; and (b) removing the food product from the freezing surface, characterised in that in step (a) a layer of a frozen aqueous solution is present between the food product and the freezing surface, the solution having a Tg? below ?60° C. and a solute concentration of from 0.001 to 20% by weight.

Abstract: A method for moulding a plastic food product comprising the steps of (a) pressing a moulding surface having a temperature of from ?10° C. to ?5O0C. against the food product to cause at least part of the product to take up the shape of the moulding surface; and (b) removing the moulding surface from the food product characterised in that in step (a) a layer of a frozen aqueous solution is present between the food product and the moulding surface, the solution having a Tg? below ?60° C. and a solute concentration of from 0.001 to 20% by weight.

Abstract: A tape construct comprises a laser-imageable composition, whereby images can be created in said tape by irradiation with a laser. In an alternative, a laser-imageable formulation suitable for spray application to a substrate, comprises a colour-former, a binder and a carrier.

Abstract: A polymer additive for improving the reheat characteristics of a polymer or polymeric composition comprises an inorganic material which is such that a 2.5 mm thick polyethylene terephthalate plaque incorporating the inorganic material has, when tested, an absorption ratio of less than 0.9, wherein the absorption ratio is either the ratio of A1/A2 or the ratio A1/A3, wherein: A1 is the maximum absorption between 400 nm and 550 nm; A2 is the maximum absorption between 700 to 1100 nm; A3 is the maximum absorption between 700 to 1600 nm. Preferred inorganic materials are titanium nitride, indium tin oxide and lanthanum hexaboride.