Thomson-Csf

Andre Couttet

Jean Claude Dubois

Armand Eranian

Evelyne Datamanti

Jean-Claude Dubois

Annie Zann

A resin crosslinkable by electron or photon irradiation (gamma rays, X-rays or ultraviolet rays), which is (after crosslinking) very stable under the action of ambient light and heat. It contains a substance the chemical formula of which comprises a thietane ring: ##STR1## notably a compound of the methacrylic ester polymer type wherein the monomer has the general formula: ##STR2## wherein n may be zero or equal to an integer from 1 to 10. The process for using such a resin consists of dissolving it in a solvent, then applying a thin layer of the solution on the object to be coated and finally treating the coating by irradiation.

Resin with a thietane ring, crosslinkable by electron photon

The invention relates to resins used for manufacturing or reproducing masks in electronics. The photomasking composition corresponds to the general formula: ##STR1## in which R.sub.1, R.sub.1 ', R.sub.1 ', R.sub.2, R.sub.2 ', R.sub.2 ' designate alkyl radicals whose principal chain contains from 1 to 10 carbon atoms, the symbols F, Cl and Br which designate the fluorine, chlorine and the bromine bearing indices a, b, c, a', b', and c' representing the number of these atoms which are zero or positive whole numbers, such as m, n, p.

Photomasking composition, process for preparing same and mask obtained

A mixture of liquid crystals comprising a substance which imparts a medium positive dielectric anisotropy, and substances which widen the mesomorphic temperature range or impart good long-term stability, is provided. The mixture in accordance with the invention comprises at least one substance of the formula: ##SPC1## Or its isomer of the formula: ##SPC2## Where R is an alkyl or alkoxy radical and at least one substance of the formula: ##SPC3## Where the radical R is of the same kind as mentioned earlier or substance of the formula: ##SPC4## Or its isomer of the formula: ##SPC5## Where R is an alkoxy radical.

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Paris, France

Andre Couttet