Processes and compositions for photogeneration of acid
AssigneePolaroid Corporation
InventorsLarry C. Takiff, Stephen J. Telfer, Kenneth C. Waterman
Life of this patent
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Abstract
An infra-red sensitive acid-generating medium comprises a binder, an iodonium salt; and a squarylium dye capable of absorbing infra-red radiation having a wavelength within the range of about 700 to about 1200 nm, the dye having a squarylium ring the 1- and 3-positions of which are each connected, via a single sp.sup.2 carbon atom, to a pyrylium, thiopyrylium, benzpyrylium or benzthiopyrylium nucleus, at least one of the sp.sup.2 carbon atoms having a hydrogen atom attached thereto, and the 2-position of the squarylium ring bearing an O.sup.-, amino or substituted amino, or sulfonamido group.
Claims24
An acid-generating medium comprising:
- a diaryl iodonium salt;
- and
- a squarylium dye capable of absorbing infra-red radiation having a wavelength within the range of 700 to 1200 nm, the dye having a squarylium ring the 1- and 3-positions of which are each connected, via a single sp.sup.2 carbon atom, to a pyrylium, thiopyrylium, benzpyrylium or benzthiopyrylium moiety, at least one of the sp.sup.2 carbon atoms having a hydrogen atom attached thereto, and the 2-position of the squarylium ring bearing an O.sup.-, amino or substituted amino, or sulfonamido group.
A process for generating acid, which process comprises:
- providing a mixture of a diaryl iodonium salt and a squarylium dye capable of absorbing infra-red radiation having a wavelength within the range of 700 to 1200 nm, the dye having a squarylium ring the 1- and 3-positions of which are each connected, via a single sp.sup.2 carbon atom, to a pyrylium, thiopyrylium, benzpyrylium or benzthiopyrylium moiety, at least one of the sp.sup.2 carbon atoms having a hydrogen atom attached thereto, and the 2-position of the squarylium ring bearing an O.sup.-, amino or substituted amino, or sulfonamido group;
- and
- irradiating the mixture with infra-red radiation having a wavelength within the range of 700 to 1200 nm, thereby causing absorption of the radiation by the squarylium dye and formation of acid in the mixture.
Dependencies are inferred from the claim text.