Method for producing a holographic film

A process for producing a holographic film comprising:

• determining the TGA 95 of compounds useful as components for a photopolymer formulation,
• i) providing the photopolymer formulation comprising:
• A) matrix polymers,
• B) writing monomers,
• C) a photoinitiator system,
• D) optionally a non-photopolymerizable component, and
• E) optionally catalysts, free radical stabilizers, solvents, additives and other auxiliaries and/or additives;
• ii) applying the photopolymer formulation as a film to a substrate film;
• and
• iii) drying the photopolymer formulation on the substrate film at a temperature of between 60 to 120° C.,
• wherein the components chosen for the photopolymer formulation are only compounds having a TGA 95 value greater than 100° C. and at least 30° C. above the drying temperature and wherein the photopolymer formulation has a plateau modulus of greater than or equal to 0.030 MPa,
• wherein the TGA 95 values of the individual photopolymer formulation components are determined by weighing an amount of about 10 mg of a sample of the respective component into a small aluminium pan having a volume of 70 μl, introducing the small aluminium pan an oven of a thermobalance, and measuring the loss of mass of the sample in the open small aluminium pan at a constant oven heating rate of 20 K/min, the start temperature of the oven being 30° C. and the end temperature 600° C., the oven being flushed with a 200 ml/min nitrogen stream during the determination and the temperature at which a loss of mass of the sample of 5% by weight, based on the originally weighed in amount of the sample, has occurred being determined as the TGA 95 value of the respective component.