Abstract: Radiation-curable resins containing a carbonyl-hydrogenated ketone-aldehyde and/or a ring-hydrogenated phenyl-aldehyde resins, and a process for preparing them.

Abstract: The present invention provides (meth)acrylate compounds bearing a specific maleimide group and resin compositions containing said compounds that can be cured by irradiation of light in a practical dose even when a photoinitiator is not used or used in a smaller amount than that of the prior art, and cured articles of the resin compositions.

Abstract: A method of preparing an ion-conducting material, for example membrane, having reduced sensitivity to water includes a step of treating an ion-conducting polymeric material (especially a sulphonated polyaryletherketone and/or sulphone) which has at least some crystallinity or which is crystallizable with a means to increase its crystallinity. The ion-conducting material prepared may be used in a Membrane Electrode Assembly of a fuel cell.

Abstract: Crosslinkable resin compositions that are cured easily by irradiation with active energy beams and particularly cured quickly with ultraviolet ray are provided, which comprises a polymer containing a maleimido group and an ethylenically unsaturated group. The composition may be an aqueous composition. They provide cured films which are excellent in durability, free from coloring and odors, and also excellent in abrasion resistance, adhesion to substrates, surface smoothness, and chemical resistance.

Abstract: Chemically cross-linked polymeric particles are formed using mechanical rather than chemical processes, facilitating production of small-diameter particles in a manner largely independent of the viscosity or density of the polymer. For example, an uncross-linked resin may be provided in particulate form, agglomerated, and compressed into a mass of a desired shape with a desired diameter, and subsequently cross-linked.

Abstract: A method for fabricating circuitized substrates which reduces shorts, and does not require baking and resulting film. The method employs a photoimageable dielectric film, having a solvent content less than about 5%, and a glass transition temperature, when cured, which is greater than about 110° C. A photoimageable dielectric film is provided having from about 95% to about 100% solids, and comprising: from 0% to about 30% of the solids, of a particulate rheology modifier; from about 70% to about 100% of the solids of an epoxy resin system (liquid at 20° C.) comprising: from about 85% to about 99.9% epoxy resins; and from about 0.1 to 15 parts of the total resin weight, a cationic photoinitiator; from 0% to about 5% solvent; applying the photoimageable dielectric film to a circuitized substrate; and exposing the film to actinic radiation.

Abstract: A method of modifying a polymeric material which comprises the steps of activation-treatment and a hydrophilic polymer-treatment, or comprises the steps of activation-treatment, a hydrophilic polymer-treatment, and monomer grafting in this order, or comprises the step of a solvent-treatment followed by these steps. Thus, the polymeric material, e.g., polyolefin, is improved in hydrophilicity, adhesion, etc. without lowering the practical strength thereof. The polymeric material thus improved in adhesion and other properties can be used in many applications where water absorption and adhesion are required, such as an absorption material, e.g., a wiping/cleansing material, a water retention material, a material for microorganism culture media, a separator for batteries (or cells), a synthetic paper, a filter medium, a textile product for clothing, a medical/sanitary/cosmetic supply, and reinforcing fibers for composite materials.

Abstract: The present invention relates to a composition for coating optical fibers that includes a UV curable coating composition. The composition includes at least one component having at least one heterocyclic moiety capable of undergoing ring opening polymerization. The composition may also include at least one acrylate functional end group. The acrylate functional group may be on the same component as the heterocyclic moiety or on a second component. The cured composition has a Young's Modulus of at least about 100 MPa.

Abstract: Low-shrinkage positioning formulations include, in addition to the resin-forming composition, a filler comprised of fibrous and spherical elements, usually of glass, present in a defined ratio and amount. The resin formulation may desirably comprise epoxy resin and a copolymerizable monomer having amide, acrylamide, or hydroxyl functionality, and may advantageously be devoid of any cationic catalyst ingredient.

Abstract: Disclosed herein are radiation-curable polymers, a method of preparing radiation-curable polymers and compositions containing radiation-curable polymers. Radiation-curable polymers and compositions containing radiation-curable polymers are useful as coatings and adhesives.

Abstract: Disclosed is a radiation-crosslinkable thermoplastic polymer composition, a process for the preparation thereof, an angioplasty balloon made using such a composition, and a method of using the angioplasty balloon. The composition contains a reactive monomer cross-linker, that facilitates cross-linking of the reaction product upon contact of the cross-linker-containing composition with a particle beam from a radiation source.

Abstract: Photopolymerization compositions which include maleimides and processes using the same are disclosed. Polymerization of compositions which include maleimides in combination with a benzophenone compound/hydrogen atom donor sensitizer system may be activated by irradiating the composition with radiation.

Abstract: A method of treating reaction injection molded polyurethane, polyurethane/urea and polyurea polymers comprising exposing a reaction injection molded polyurethane, polyurethane/urea or polyurea polymer to an amount of infrared energy sufficient to increase the temperature of the polymer to at least 175° C., and then maintaining the temperature of the polymer at or above that temperature, for a time sufficient to increase the Gardner impact property, as measured using ASTMD-3029, when compared to the same polymer which has been heated to the same temperature and maintained thereat for the same time in a convection oven. The invention produces marked improvements in impact, heat sag and heat distortion temperature properties, and thus is particularly suited to rapid preparation of parts using a mass production conveyor and is particularly well-suited to preparation of parts which are to be subjected to later high temperature processes, such as the “E-coat” process.

Abstract: An Offset Lithographic Printing Process employing low VOC lithographic printing ink formulations containing monomeric diluents, curable by cationic polymerization in the presence of fountain solution and resin rheology modifiers compatible with cationic catalysts.

Abstract: A highly reliable ink jet recording head excellent in mechanical strength, weatherability, ink resistance, and adhesion to the substrate is provided. For its production, a cationically polymerized curing product of an epoxy resin having a structural unit expressed by the following formula (I) or (II), is used as a resin material which coats an ink flow path pattern formed from a dissoluble resin on the substrate.

Abstract: In order to offer coatings with improved resistance to solvents which can be prepared by cationic polymerization under irradiation, the choice is made of a composition comprising at least one monomer, oligomer or polymer of general formula (I): in which: A1 is chosen from polyester blocks, polyurethane blocks, hydrocarbon-comprising backbones of mono- or polycarboxylic acid and addition products of a polycarboxylic acid and of a cycloaliphatic diepoxide, m is a number from 1 to 6, R1 is a cycloaliphatic group carrying a hydroxyl group situated in the a position with respect to the oxygen atom to which R1 is bonded, R2 is a second cycloaliphatic group carrying an oxirane group situated at the chain end, and B is chosen from one or more covalent bonds, an oxygen atom and linear, branched or cyclic hydrocarbon-comprising radicals.

Abstract: Radiation-sensitive resin composition having excellent and well-balanced various properties required for photoresist, such as sensitivity, pattern profile and heat resistance. The radiation-sensitive resin composition comprises an alkali-soluble resin and a photosensitizer having a quinonediazide group. The alkali-soluble resin is a phenol novolak resin which is treated by a thin film distillation method to selectively remove monomer and dimer. The novolak resin treated by thin film distillation method preferably shows the following ratio in area in its profile in gel permeation chromatography with a detector at 280 nm: B2/B1≧0.95; C2/(A2+B2+C2)≦0.060 wherein A1 is a high-molecular region, B1 is a middle-molecular region, and C1 is a monomer/dimer region before the treatment of the starting novolak resin, and A2, B2 and C2 are the corresponding counterparts after the treatment of the novolak resin.

Abstract: A photocurable resin composition suitable for photo-fabrication. The resin composition capable of being promptly cured by photo-irradiation, thereby reducing fabricating time and providing cured products having excellent mechanical strength and minimized shrinkage during curing to ensure high dimensional accuracy. The composition includes (A) an oxetane compound, (B) an epoxy compound, and (C) a cationic photo-initiator.

Abstract: Disclosed is a composition which comprises a polymer containing at least some monomer repeat units with photosensitivity-imparting substituents which enable crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer being of the formula wherein x is an interger of 0 or 1, A is one of several specified groups, such as B is one of several specified groups, such as or mixtures thereof, and n is an integer representing the number of repeating monomer units, wherein said photosensitivity-imparting substituents are allyl ether groups, epoxy groups, or mixtures thereof. Also disclosed are a process for preparing a thermal ink jet printhead containing the aforementioned polymers and processes for preparing the aforementioned polymers.

Abstract: New imido(meth) acrylates of general formula (1), wherein R1, R2 and R3 may be the same or different and each represents H or CH3; R4 to R7 may be the same or different and each represents H or CmH2m+1 (in which m is 1 to 6); and n represents 1 to 4, and radiation-curable compositions prepared from them, easily cured by the irradiation with radiations, particularly ultraviolet rays, to form cured compositions excellent in weather resistance, abrasion resistance and adhesion to a base, and free from the problem of odor.

Abstract: The present invention provides a polymer that can be used as an anti-refelctive coating (ARC) polymer, an ARC composition comprising the same, methods for producing the same, and methods for using the same. The polymer of the present invention is particularly useful in a submicrolithographic process, for example, using KrF (248 nm), ArF (193 nm), or F2 (157 nm) laser as a light source. The polymer of the present invention comprises a chromophore that is capable of absorbing light at the wavelengths used in a submicrolithographic process. Thus, the ARC of the present invention significantly reduces or prevents back reflection of light and the problem of the CD alteration caused by the diffracted and/or reflected light. The ARC of the present invention also significantly reduces or eliminates the standing wave effect and reflective notching.

Abstract: Describes polymerizing with actinic radiation a cationically polymerizable organic composition comprising (a) at least one polyfunctional thiirane having at least two groups represented by the following general formula I, 1

Abstract: Disclosed is a composition comprising a polymer with a weight average molecular weight of from about 1,000 to about 100,000, said polymer containing at least some monomer repeat units with a first, photosensitivity-imparting substituent which enables crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer also containing a second, thermal sensitivity-imparting substituent which enables further crosslinking or chain extension of the polymer upon exposure to temperatures of about 140° C.

Abstract: Disclosed is a composition which comprises a polymer containing at least some monomer repeat units with water-solubility- or water-dispersability-imparting substituents and at least some monomer repeat units with photosensitivity-imparting substituents which enable crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer being of the formula wherein x is an integer of 0 or 1, A is one of several specified groups, such as B is one of several specified groups, such as or mixtures thereof, and n is an integer representing the number of repeating monomer units. In one embodiment, a single functional group imparts both photosensitivity and water solubility or dispersability to the polymer. In another embodiment, a first functional group imparts photosensitivity to the polymer and a second functional group imparts water solubility or dispersability to the polymer.

Abstract: Production of a dielectric coating on a substrate whereby a poly(arylene ethers) or fluorinated poly(arylene ethers) layer is cured by exposure to electron beam radiation. A wide area electron beam is used which causes chemical reactions to occur in the polymer structure which are thought to cause crosslinks between polymer chains. The crosslinks lead to higher mechanical strength and higher glass transition temperature, lower thermal expansion coefficient, greater thermal-chemical stability and greater resistance to aggressive organic solvents. The polymer layer may also be optionally heated, thermally annealed, and/or exposed to UV actinic light.

Abstract: An epoxy resin containing group(s) of formula (1) and having a number average molecular weight of 400-10,000, an epoxy equivalent of 100-5,000 and an average number of glycidyl ether groups per molecule of 2-50 wherein A is a group (wherein R3 is a saturated aliphatic polyhydric alcohol residue having 2 to 30 carbon atoms, D is oxyalkylene group, a, b, c and d are 0-25, e and f are 0-4, e+f equals 0-4 and a+b+c×e+d×f equals 0-50), and B is (g, h are 0-18), etc. and R1 and R2 are H, glycidyl or a group of the formula wherein A and B are as defined above, and R7, R8 and R9 are H or glycidyl group; its preparation, and photo-curable and powder coating resin compositions containing the same.

Abstract: Cross-linked electrically conductive polymers, in particular electrically conductive, polyaniline are described. Dopants and substituents having pendant cross-linkable functionality are used which form a cross-linked conducting polymer network. The cross-linking functionality can be hydrogen-bonding as well as chemically polymerizable or cross-linkable. A conjugated path between chains can also be incorporated. The resulting cross-linked conducting polymers have enhanced thermal and environmental stability. The dopant cannot readily be washed out with solvents or diffuse out upon exposure to heat. In addition, the cross-linked polymers have enhanced electrical conductivity.

Abstract: A novel process for producing mouldings, especially contact lenses, is described, comprising the following steps: a) introducing into a mould a prepolymer containing photo crosslinkable groups that is liquid at room temperature or is readily meltable and is substantially free of solvents; b) initiating the photo cross-linking for a period of <20 minutes; c) opening the mould, so that the moulding can be removed for the mould. In accordance with the process according to the invention, it is possible especially to produce contact lenses having valuable properties.

Abstract: Disclosed is a process which comprises reacting a polymer of the general formula wherein x is an integer of 0 or 1, A is one of several specified groups, such as B is one of several specified groups, such as or mixtures thereof, and n is an integer representing the number of repeating monomer units, with a halomethyl alkyl ether, an acetyl halide, and methanol in the presence of a halogen-containing Lewis acid catalyst, thereby forming a halomethylated polymer.

Abstract: A composition which comprises a mixture of (A) a first component comprising a polymer, at least some of the monomer repeat units of which have at least one photosensitivity-imparting group thereon, said polymer having a first degree of photosensitivity-imparting group substitution and being of the formulae specified in the claims, and (B) a second component which comprises either (1) a polymer having a second degree of photosensitivity-imparting group substitution lower than the first degree of photosensitivity-imparting group substitution, wherein said second degree of photosensitivity-imparting group substitution may be zero, wherein the mixture of the first component and the second component has a third degree of photosensitivity-imparting group substitution which is lower than the first degree of photosensitivity-imparting group substitution and higher than the second degree of photosensitivity-imparting group substitution, or (2) a reactive diluent having at least one photosensitivity-imparting group per

Abstract: Disclosed is a composition comprising a polymer with a weight average molecular weight of from about 1,000 to about 100,000, said polymer containing at least some monomer repeat units with a first, photosensitivity-imparting substituent which enables crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer also containing a second, thermal sensitivity-imparting substituent which enables further crosslinking or chain extension of the polymer upon exposure to temperatures of about 140.degree. C.

Abstract: A polymer which can be crosslinked by high-energy radiation and contains from 0.1 to 50% by weight, based on the polymer, of 2,3-dihydrofuran groups or derivatives thereof, each calculated as 2,3-dihydrofuran.

Abstract: Disclosed is a composition comprising a polymer with a weight average molecular weight of from about 1,000 to about 100,000, said polymer containing at least some monomer repeat units with a first, photosensitivity-imparting substituent which enables crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer also containing a second, thermal sensitivity-imparting substituent which enables further crosslinking or chain extension of the polymer upon exposure to temperatures of about 140.degree. C.

Abstract: Disclosed is a process which comprises the steps of (a) providing a polymer containing at least some monomer repeat units with halomethyl group substituents which enable crosslinking or chain extension of the polymer upon exposure to a radiation source which is electron beam radiation, x-ray radiation, or deep ultraviolet radiation, said polymer being of the formula ##STR1## wherein x is an integer of 0 or 1, A is one of several groups, as specified in the claims, and B is one of several groups, as specified in the claims or mixtures thereof, and n is an integer representing the number of repeating monomer units, and (b) causing the polymer to become crosslinked or chain extended through the photosensitivity-imparting groups. Also disclosed is a process for preparing a thermal ink jet printhead by the aforementioned curing process.

Abstract: Disclosed is a process which comprises reacting a polymer of the general formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3##

Abstract: This invention relates to polyvinyl acetals containing the units A, B, C and D, whereinA is present in an amount of 0.5 to 20 wt.-% and is of the formula ##STR1## B is present in an amount of 15 to 35 wt.-% and is of the formula ##STR2## C is present in an amount of 10 to 50 wt.-% and is of the formula ##STR3## wherein R.sup.1 is an alkyl group with up to 4 carbons, which is optionally substituted by an acid group, or a phenyl group, to which an acid group is attached, wherein the phenyl group optionally comprises 1 to 2 further substituents selected from halos, amino, methoxy, ethoxy, methyl and ethyl groups, or is a group X--NR.sup.6 --CO--Y--COOH, wherein X is an aliphatic, aromatic or araliphatic spacer group, R.sup.6 is hydrogen or an aliphatic, aromatic or araliphatic moiety and Y is a saturated or unsaturated chain- or ring-shaped spacer group, and this unit C may be contained several times with various moieties R.sup.1 independent of one another, and D is present in an amount of 25 to 70 wt.

Abstract: Cross-linked electrically conductive polymers, in particular electrically conductive, polyaniline are described. Dopants and substituents having pendant cross-linkable functionality are used which form a cross-linked conducting polymer network. The cross-linking functionality can be hydrogen-bonding as well as chemically polymerizable or cross-linkable. A conjugated path between chains can also be incorporated. The resulting cross-linked conducting polymers have enhanced thermal and environmental stability. The dopant cannot readily be washed out with solvents or diffuse out upon exposure to heat. In addition, the cross-linked polymers have enhanced electrical conductivity.

Abstract: Disclosed is an improved composition comprising a photopatternable polymer containing at least some monomer repeat units with photosensitivity-imparting substituents, said photopatternable polymer being of the general formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3## or mixtures thereof, and n is an integer representing the number of repeating monomer units. Also disclosed is a process for preparing a thermal ink jet printhead with the aforementioned polymer and a thermal ink jet printhead containing therein a layer of a crosslinked or chain extended polymer of the above formula.

Abstract: Disclosed is a composition which comprises a polymer containing at least some monomer repeat units with water-solubility- or water-dispersability-imparting substituents and at least some monomer repeat units with photosensitivity-imparting substituents which enable crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer being of the formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3## or mixtures thereof, and n is an integer representing the number of repeating monomer units. In one embodiment, a single functional group imparts both photosensitivity and water solubility or dispersability to the polymer. In another embodiment, a first functional group imparts photosensitivity to the polymer and a second functional group imparts water solubility or dispersability to the polymer.

Abstract: Disclosed is an improved composition comprising a photopatternable polymer containing at least some monomer repeat units with photosensitivity-imparting substituents, said photopatternable polymer being of the general formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3## or mixtures thereof, and n is an integer representing the number of repeating monomer units. Also disclosed is a process for preparing a thermal ink jet printhead with the aforementioned polymer and a thermal ink jet printhead containing therein a layer of a crosslinked or chain extended polymer of the above formula.

Abstract: Disclosed is a composition for preparing a thermal ink jet printhead which comprises a mixture of (A) a polymer, some monomer repeat units of which have at least one photosensitivity-imparting group thereon, said polymer having a first degree of photosensitivity-imparting group substitution measured in milliequivalents photosensitivity-imparting group per gram either (1) a polymer having a second degree of photosensitivity-imparting group substitution measured in milliequivalents of photosensitivity-imparting group per gram lower than the first degree of photosensitivity-imparting group substitution, wherein said second degree of photosensitivity-imparting group substitution may be zero, wherein the mixture of the first component and the second component has a third degree of photosensitivity-imparting group substitution measured in milliequivalents of photosensitivity-imparting group per gram which is lower than the first degree of photosensitivity-imparting group substitution and higher than the second degr

Abstract: Disclosed is a composition which comprises a polymer containing at least some monomer repeat units with photosensitivity-imparting substituents which enable crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer being of the formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3## or mixtures thereof, and n is an integer representing the number of repeating monomer units, wherein said photosensitivity-imparting substituents are allyl ether groups, epoxy groups, or mixtures thereof. Also disclosed are a process for preparing a thermal ink jet printhead containing the aforementioned polymers and processes for preparing the aforementioned polymers.

Abstract: A method for the anionic photoinitiation of polymerization or crosslinking of a substrate by irradiating a mixture of a substrate and a photoinitiator, where the photoinitiator is an inorganic transition metal complex which releases on irradiation a polymerization initiating substance consisting essentially of an anionically charged nucleophile that initiates the polymerization or crosslinking reaction, under conditions that allow the anion to initiate polymerization. FIG. 3 is plot of percentage polymerization of ethyl .alpha.-cyanoacrylate containing different concentration of Reineckate's anion.

Abstract: Disclosed is a process which comprises the steps of (a) providing a polymer containing at least some monomer repeat units with halomethyl group substituents which enable crosslinking or chain extension of the polymer upon exposure to a radiation source which is electron beam radiation, x-ray radiation, or deep ultraviolet radiation, said polymer being of the formula ##STR1## wherein x is an integer of 0 or 1, A is one of several groups as specified in the claims, B is one of several groups as specified in the claims, and n is an integer representing the number of repeating monomer units, and (b) causing the polymer to become crosslinked or chain extended through the photosensitivity-imparting groups. Also disclosed is a process for preparing a thermal ink jet printhead by the aforementioned curing process.

Abstract: Disclosed is a composition which comprises (a) a polymer containing at least some monomer repeat units with photosensitivity-imparting substituents which enable crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer being of the formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3## or mixtures thereof, and n is an integer representing the number of repeating monomer units, wherein said photosensitivity-imparting substituents are hydroxyalkyl groups; (b) at least one member selected from the group consisting of photoinitiators and sensitizers; and (c) an optional solvent. Also disclosed are processes for preparing the above polymers and methods of preparing thermal ink jet printheads containing the above polymers.

Abstract: Radiation-sensitive organo-halogen compounds that have a photo-labile halomethyl-1,3,5-triazine moiety and a polymeric moiety within the same molecule. The compounds of this invention are comprised of a polymeric moiety having attached or incorporated within its structure at least one 1,3,5-triazine nucleus, said triazine nucleus having at least one halomethyl substituent attached to a carbon atom of the triazine nucleus. These compounds are capable of being stimulated by actinic radiation at wavelengths of from about 250 to about 900 nanometers to generate free radicals and/or acids. The compounds of this invention are useful as photoinitiators in free radical polymerization reactions, oxidation-reduction reactions, or reactions sensitive to acid, and they also exhibit the capability to crosslink upon exposure to light.

Abstract: Disclosed is a positive radiation-sensitive resist composition comprising polymer(s) of the following general formula (1) and a radiation-sensitive agent. ##STR1## Ra, Rb, Rc and Rd each are independently a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an alkenyl group, an aryl group, an aralkyl group, an alkoxycarbonyl group, an arylcarbonyl group, an acyloxy group, an acyl group, or a cycloalkyl group; k is an integer of from 1 to 30; (1+n) is an integer of from 1 to 100; m is an integer of from 1 to 50; p1, p2 and p3 each are an integer of from 1 to 3; q1 is an integer of from 1 to 4. The resist composition has high resolution to give resist patterns with good profiles and has high heat resistance and good storage stability.

Abstract: A polyfunctional vinyl ether compound represented by formula (I): ##STR1## wherein n, which is an average repeating number, represents a number of from 0 to 20; R.sub.1 and R.sub.2 each independently represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, or a cycloalkyl group; Q each independently represents --OH or a group represented by the formula --OROCH.dbd.CH.sub.2, wherein R represents an alkylene group having from 1 to 12 carbon atoms, the molar ratio of (--OH)/(--OROCH.dbd.CH.sub.2) being from 10/90 to 90/10; and A each independently represents a divalent hydrocarbon group having from 1 to 30 carbon atoms.

Abstract: The present invention provides positive-tone and negative-tone photoresists including a photoinitiator comprising a compound of Formula (I): ##STR1## wherein R.sub.1 and R.sub.2 are independently selected from C.sub.1 -C.sub.6 alkyl; n is a number from 2 to 5, and An.sup.- is an anion. The photoinitiator comprising the compound of Formula (I) being soluble in water. Methods of preparing positive-tone and negative-tone photoresists are also provided.

Abstract: A polyimide obtained by reacting an acid dianhydride such as catechol bistrimellitate dianhydride, bisphenol A bistrimellitate dianhydride, etc. with a diamine such as 4,4'-diamino-3,3',5,5'-tetraisopropyl-diphenylmethane, etc. has high solubility in organic solvents and good moldability at low temperatures, and can provide a thermosetting resin composition together with a polymaleimide.