Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/14—Polycondensates modified by chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
  • C08F290/02—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated end groups
  • C08F290/06—Polymers provided for in subclass C08G
  • C08F290/064—Polymers containing more than one epoxy group per molecule
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/02—Polycondensates containing more than one epoxy group per molecule
  • C08G59/10—Polycondensates containing more than one epoxy group per molecule of polyamines with epihalohydrins or precursors thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/14—Polycondensates modified by chemical after-treatment
  • C08G59/1433—Polycondensates modified by chemical after-treatment with organic low-molecular-weight compounds
  • C08G59/1438—Polycondensates modified by chemical after-treatment with organic low-molecular-weight compounds containing oxygen
  • C08G59/1455—Monocarboxylic acids, anhydrides, halides, or low-molecular-weight esters thereof
  • C08G59/1461—Unsaturated monoacids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/14—Polycondensates modified by chemical after-treatment
  • C08G59/1494—Polycondensates modified by chemical after-treatment followed by a further chemical treatment thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/20—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the epoxy compounds used
  • C08G59/22—Di-epoxy compounds
  • C08G59/28—Di-epoxy compounds containing acyclic nitrogen atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/4007—Curing agents not provided for by the groups C08G59/42 - C08G59/66
  • C08G59/4014—Nitrogen containing compounds
  • C08G59/4028—Isocyanates; Thioisocyanates
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/42—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof
  • C08G59/4292—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof together with monocarboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
  • C08L63/10—Epoxy resins modified by unsaturated compounds

Definitions

• the present invention relates to novel nitrogen-containing epoxy resin compositions suitable for use in photocurable compositions, including photoresist materials such as solder mask coating formulations.
• Canadian Patent Application Publication No. 2,127,203 discloses epoxy acrylates and carboxyl group-containing epoxy acrylates of higher molecular weight for use in photoresist formulations.
• Canadian Patent Application Publication No. 2,127,238 discloses photopolymerizable compositions for use as photoresists, such as for coating printed circuit boards and for making solder masks.
• novel intermediate compositions useful for making novel photopolymerizable compositions and (2) novel photopolymerizable compositions including, for example, a modified epoxy novolac resin formulation that has improved adhesion on substrates and higher photospeed when the modified epoxy novolac resin contains a nitrogen element.
• One embodiment of the present invention is directed to an acrylated epoxy resin composition useful as an intermediate for a photocurable resin composition, said acrylated epoxy resin prepared by reacting:
• Another embodiment of the present invention is directed to a half-ester resin composition useful for a photocurable resin composition, said half-ester prepared by reacting:
• Still another embodiment of the present invention is directed to a photocurable composition prepared by mixing: (a) the half-ester resin described above;
• Another aspect of the present invention is directed to a process for making an acrylated epoxy resin composition comprising reacting:
• Another aspect of the present invention is directed to a process for making a half-ester resin composition useful for a photocurable resin composition comprising reacting: (a) the acrylated epoxy resin described above; and
• Still another aspect of the present invention is directed to a process for making a photocurable composition comprising mixing:
• Yet another aspect of the present invention is directed to a cured product such as a cured coating on a substrate including: (a) the photocurable composition described above and (b) a curing source such as a radiation energy source, for example, electron beam, ultra violet (UV) light, microwave, infrared light or heat.
• a radiation energy source for example, electron beam, ultra violet (UV) light, microwave, infrared light or heat.
• compositions of the present invention are directed to photoresist materials such as solder mask coating formulations based on nitrogen element-containing epoxy resins obtained, for example, from the advanced products of (a) epoxy novolacs such as D.E.N.TM 438 (Trademark of The Dow Chemical Company) and (b) nitrogen-containing compounds such as methyiene diphenyl diisocyanate, toluene diisocyanate (TDI), sulfanilamide and 2,6-dimethylcyclohexylamine.
• epoxy novolacs such as D.E.N.TM 438 (Trademark of The Dow Chemical Company)
• nitrogen-containing compounds such as methyiene diphenyl diisocyanate, toluene diisocyanate (TDI), sulfanilamide and 2,6-dimethylcyclohexylamine.
• the base epoxy polymer have a softening point of greater than or equal to 50°C.
• the advanced epoxy product of the present invention that is, a nitrogen element modified-epoxy resin of the present invention, has a higher softening point and a higher molecular weight than an unmodified-epoxy resin.
• the difference in softening point of a nitrogen element modified epoxy resin of the present invention from the softening point of an unmodified epoxy resin can be from 10°C to 60°C higher and preferably from 20°C to 50°C higher.
• the difference ( ⁇ ) in molecular weight as measured by epoxy equivalent weight (EEW) of a nitrogen element modified epoxy resin of the present invention from the molecular weight of an unmodified epoxy resin can be from 15 EEW to 250 EEW ⁇ molecular weight higher, preferably from 20 EEW to 160 EEW higher, more preferably from 25 EEW to 120 EEW higher and even more preferably from 30 EEW to 80 EEW higher.
• modified epoxy-functional resins for example, polyisocyanate- modified epoxy resins, have been shown to exhibit improved adhesion to a coated substrate and higher photospeed than unmodified-epoxy resins (for example, cresol novolacs or phenol novolac epoxy resins).
• the difference in adhesion of a nitrogen element modified-epoxy resin of the present invention from the adhesion of an unmodified-epoxy resin can be from 5 percent to 50 percent higher and preferably from 10 percent to 30 percent higher.
• the difference in photospeed of a nitrogen element modified-epoxy resin of the present invention from the photospeed of an unmodified-epoxy resin can be from 10 percent to 100 percent higher and preferably from 20 percent to 50 percent higher.
• the epoxy resin compositions of the present invention advantageously provide improved adhesion on a substrate and higher photospeed when the epoxy resin composition is modified to contain a nitrogen element.
• the starting materials of the present invention include (a) a polyepoxide resin and (b) a nitrogen-containing advancement monomer compound which are reacted together to form a nitrogen-containing modified advanced polyepoxide resin.
• the advanced polyepoxide advantageously has an increased softening point, for example, greater than or equal to 50°C.
• the advanced polyepoxide is acrylated and then anhydride modified to produce a free-radical photocurable resin which can be lithographically developed with aqueous solutions.
• photocurable resin products are useful in the electronic coatings industry; particularly for the formulation of solder masks.
• the polyepoxide compound useful in the practice of the present invention is suitably a compound which possesses more than one 1 ,2-epoxy group.
• the polyepoxide compound is a saturated or unsaturated aliphatic, cycloaliphatic, aromatic or heterocyclic compound which possesses more than one 1 ,2-epoxy group.
• the polyepoxide compound can be substituted with one or more substituents which are non-reactive with the nitrogen-containing groups of the advancement polymer such as lower alkyls and halogens.
• Such polyepoxide compounds are well known in the art. Illustrative polyepoxide compounds useful in the practice of the present invention are described in the Handbook of Epoxy Resins, by H. E. Lee and K. Neville, published in 1967 by McGraw-Hill, New York and U.S. Patent No. 4,066,628.
• Formula I (wherein "R” is a substituted or unsubstituted aromatic, aliphatic, cycloaliphatic or heterocyclic polyvalent group and "n" has an average value of from greater than 1 to less than 10.
• R is a substituted or unsubstituted aromatic, aliphatic, cycloaliphatic or heterocyclic polyvalent group and "n” has an average value of from greater than 1 to less than 10.
• epoxy novolac resins and diepoxide resins are used in the present invention.
• diepoxides which may be used in the present invention include, for example, diglycidyl ether of
• 2,2-bis(4-hydroxyphenyl)propane generally referred to as bisphenol A
• diglycidyl ether of 2,2,-bis(3,5-dibromo-4-hydroxyphenyl)propane generally referred to as tetrabromobisphenol A
• Diepoxides also useful in the present invention include, for example, diglycidyl ether of 4,4'-dihydroxy-alpha-methylstilbene (DHAMS) and diglycidyl ether of 9,9-bis(4-hydroxyphenyl)fluorene (BHPF). Mixtures of any two or more polyepoxides can also be used in the practice of the present invention.
• Epoxy novolac resins (sometimes referred to as epoxidized novolac resins, a term which is intended to embrace both epoxy phenol novolac resins and epoxy cresol novolac resins) are polyepoxy compounds having the following general formula:
• R is a hydrogen atom or a lower alkyl, for example, methyl groups; and "n” is 0 or an integer from 1 to 6.
• Epoxy novolac resins are readily commercially available, for example, under the trademark D.E.N.TM, QUATREXTM, GrilonitTM (ESN) and AralditeTM (ECN).
• the materials of commerce generally comprise mixtures of various species of the above formula and a convenient way of characterizing such mixtures is by reference to the average, n', of the values of n for the various species.
• Preferred epoxy novolac resins for use in accordance with the present invention are those in which n' has a value of from 2.05 to 10, more preferably from 3 to 5.
• the nitrogen-containing advancement monomers useful in the practice of the present invention are selected from isocyanates, amines and amides.
• the nitrogen-containing advancement monomers useful in the practice of the present invention include, for example, polyisocyanate compounds which form epoxy- terminated polyoxazolidones as described in U.S. Patent No. 5,112,932.
• the polyisocyanate compound used in the present invention is 4,4'-methylene bis(phenylisocyanate) (MDI) and isomers thereof and functional homologs of MDI (commonly designated as "polymeric MDI").
• MDI 4,4'-methylene bis(phenylisocyanate)
• Isocyanate compounds also useful in the present invention include, for example, toluene diisocyanate (TDI) and isomers thereof.
• the nitrogen-containing advancement monomers useful in the practice of the present invention also include, for example, amine- or amino amide-containing compounds which form epoxy-terminated amine compounds having two N-H bonds capable of reacting with an epoxy group.
• Amine-containing compounds useful in the present invention include, for example, mono-primary amines of the general formula R-NH 2 wherein R is alky!, cycloalkyl or aryl moieties; di-secondary amines of the general formula R-NH-R'-NH-R" wherein R, R' and R" are alkyl, cycloalkyl or aryl moieties; and heterocyclic di-secondary amines wherein one or both of the N atom is part of a nitrogen-containing heterocyclic compound such as:
• di-secondary amines or primary amines having sterically hindered amine groups are preferred as for example, 2,6-dimethylcyclohexylamine or 2,6-xylidene (1-amino-2,6-dimethylbenzene).
• Amino amide-containing compounds useful as advancement monomers in the present invention include for example, derivatives of carboxylic acids and amides as well as derivatives of sulfonic acid amides having additionally one primary or two secondary amino groups.
• Preferred examples of such compounds are amino-aryl carboxylic acid amides and amino-arylsulfonamides.
• a preferred compound of this group is, for example, sulfanilamide (4-amino benzylsulfonic acid amide).
• the advanced polyepoxide resin is obtained by reacting a polyepoxide with a nitrogen-containing advancement monomer as described above, the advanced polyepoxide is acrylated to form an epoxy acrylate.
• the acrylation of the advanced epoxy resins is preferably carried out with an unsaturated carboxylic acid, for example, acrylic or methacrylic acid. More preferably, an acrylic acid is used in the present invention.
• Other acrylation materials include, for example, trans-3-phenyl acrylic acid.
• the epoxy acrylate resin is esterified with an unsaturated or saturated anhydride to form a half-ester.
• the anhydride materials useful in the practice of the present invention include, for example, the saturated carboxylic acid anhydrides described in the Handbook of Epoxy Resins, by Lee and Neville in Page 12-6 including, for example, succinic anhydride, alkenyl anhydride, dodecenylsuccinic anhdyride, hexahydrophthalic anhydride, phthalic anhydride, and methylhexahydrophthalic acid anhydride (MHHPA).
• the anhydride esterification reaction to the half-ester of the epoxy acrylate resin is preferably carried out with MHHPA.
• the anhydride modified advanced epoxy resin acrylate described above is the product which can be used as a photoresist material.
• Photoresist materials include for example, photoimageable resins for solder mask applications and etch resist applications.
• Other photoresist materials include, for example, plating resists.
• the process of preparing the photocurable compositions of the present invention comprises the steps of (1) reacting a polyepoxide resin and a nitrogen-containing advancement monomer compound together to form a nitrogen-containing modified advanced polyepoxide resin; (2) reacting the advanced polyepoxide of Step (1 ) above with an acrylation material to form an epoxy acrylate; and (3) reacting the epoxy acrylate resin of Step (2) above with an unsaturated or saturated anhydride to form a half-ester.
• a nitrogen-containing epoxy resin useful for photoimageable coating applications includes (1) advancing a low molecular weight epoxy novolac resin with a nitrogen-containing compound such as diphenylmethane diisocyanate, (2) fully acrylating the advanced epoxy novolac resin with acrylic acid, and (3) esterifying the acrylated resin to the half-ester with methylhexahydrophthalic anhydride.
• a nitrogen-containing compound such as diphenylmethane diisocyanate
• reaction conditions that is, temperatures and pressures that allow the reaction to proceed.
• ingredients that do not adversely effect the reaction may be used; for example, a catalyst may be used in each of the reaction steps of the present process.
• the advancement reaction such as the reaction of an epoxy novolac resin(s) with an amine-containing compound(s) is carried out by reacting the epoxy novolac resin with the amine-containing compound, generally at temperatures of from 60°C to 200°C, preferably from 100°C to 150°C and optionally, the reaction is carried out in the presence of a catalyst.
• the advancement reaction such as reaction of an epoxy novolac resin(s) with an isocyanate compound(s) is carried out by reacting the epoxy novolac resin with the isocyanate compound, generally at temperatures of from 120°C to 200°C, preferably from 150°C to 180°C, in the presence of a catalyst.
• the catalysts useful in the advancement reaction step include for example, tertiary amines, phosphines, imidazoles, and ammonium and phosphonium salts.
• Examples of the catalysts useful in this reaction step include quaternary ammonium and phosphonium salts such as tetraphenylphosphonium chloride; tertiary amines; nitrogen-containing heterocycles such as: substituted imidazoles including 1-methylimidazole, 2-methylimidazole, 1-phenylimidazole, 2-phenylimidazole, benzimidazole, 2-ethyl-4- methylimidazole, 1 -benzyl, 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole;
• DABCO 1 ,4-diazabicyclo[2.2.2]octane
• DBU 1 ,8-diazabicyclo[5.4.0]undecene-7
• DBN 1 ,5- diazabicyclo[4.3.0]non-5-ene
• substituted phosphines such as triphenylphosphine and mixtures thereof.
• the preferred catalysts useful in this step are the substituted imidazoles, most preferably 1-phenylimidazole, 2-phenylimidazole, and DBU or DBN. Above 200°C, the advancement reaction is not economically effective and below 60°C, the advancement reaction is too slow to be effective.
• the reaction temperature is generally from 80°C to 150°C, preferably 100°C to 130°C.
• the acrylation reaction step requires a catalyst, for example, when reacting an advanced epoxy with acrylic acid.
• the catalyst useful in this step can be for example, tertiary amines such as triethylamine, tributylamine, triphenylamine, benzyldimethylamine, tris(dimethylaminomethyl)phenol; phosphines such as triphenylphosphine; imidazoles such as 1 -methylimidazole, 2-methylimidazole, 1-phenylimidazole, 2-phenylimidazole, benzimidazole, 2-ethyl-4-methylimidazole, 1 -benzyl, 2-phenylimidazole; heterocyclic amino compounds such as: benzotriazole, pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2,3-d
• the acrylation reaction also requires an inhibitor to stop the double bond compounds such as acrylic acid from reacting or polymerizing with itself, that is, the inhibitor is used to prevent radical polymerization.
• inhibitors useful in the acrylation step include, for example, hydroquinone and those described in U.S. Patent No. 4,413,105.
• a solvent is optionally used in the acrylation reaction step to control the reaction mixture viscosity and better control the reaction. For example when a high molecular weight material is used, a solvent can be optionally used.
• solvents useful in this step include, for example, those solvents having a boiling point higher than 110°C and do not react with any of the components of the present composition such as DowanolTM PMA or xylene or toluene.
• the acrylation reaction step also requires the use of an oxygen-containing stream such as air to help activate the inhibitor.
• the acrylation step of the process of the present invention is carried out such that all or 100 percent of the epoxy groups on the advanced polyepoxide are reacted with acrylic acid groups, preferably from 75 percent to 100 percent, more preferably from 85 percent to 99 percent, and most preferably from 90 percent to 97 percent of the epoxy groups are reacted.
• the acrylation reaction step is carried out to provide a residual acid percentage of the resin of generally less than about 1 percent, preferably less than about 0.5 percent, more preferably less than about 0.2 percent and most preferably less than about 0.1 percent.
• the esterification of the advanced acrylated epoxy resin is generally carried out at temperatures of from 80°C to 130°C, preferably from 110°C to 130°C.
• this esterification step is carried out in the presence of a catalyst such as those used in the acrylation step above including for example, a tertiary amine, phosphine, ammonium or phosphonium salt or a metal salt of an organic or inorganic acid.
• a solvent may be optionally used in this esterification step.
• the solvent used is not a hydroxy- containing solvent because the hydroxy-containing solvent can react with the anhydride groups.
• the resin contains an acid value generally in the range of from 20 to 200, preferably from 50 to 150, more preferably from 80 to 120 and most preferably from 90 to 105 acid value.
• the present invention is also directed to a process for making a photocurable composition comprising mixing or blending together: (a) the half-ester resin described above;
• the photocurable materials (esters) in accordance with the present invention are readily photocurable by the action of ultra violet light in the presence of a conventional photoinitiator.
• the present invention accordingly, provides a photocurable composition
• a photocurable composition comprising a photocurable material as defined above together with a photoinitiator.
• Such compositions may also, and indeed, generally will, contain other ingredients such as, for example, diluents, colorants or fillers.
• Suitable photosensitizers or photoinitiators for use in the photocurable compositions of the present invention include, for example, benzophenone, substituted benzophenones, 2-chlorothioxanthone, isopropylthioxanthene, dialkyl-p-dimethylamine benzoates (including the diethyl, amyl/isoamyl and ethyl hexyl compounds), and 2-cleavage initiators, such as those sold under the trademarks DarocurTM 1 173, IrgacureTM 174, IrgacureTM 184, IrgacureTM 651 , IrgacureTM 907, IrgacureTM 369, EsacureTM KIP, and LucirinTM 7PO.
• an initiator system will comprise a mixture of two or more compounds as listed above.
• Examples of diluents possibly employed in the photocurable compositions of the present invention may be tris(2-hydroxyethyl)isocyanate triacrylate and trimethylol propane triacrylate.
• the colorants which may be used in the photocurable composition of the present invention may be selected from phthalocyanine green and methylene blue.
• Suitable fillers which can be used in the photocurable composition of the present invention may include, for example, silicas, bentonite clays, talc, alumina hydrate, barium sulfate, calcium carbonate and magnesium carbonate.
• the photocurable composition generally comprises (I) an epoxy, (II) a diluent, (III) a photoinitiator, and (IV) a colorant.
• the photocurable composition suitably comprises from 10 to 95 percent by weight (weight percent), preferably from 20 to 70 weight percent of (I); from 1 to 20 weight percent, preferably from 2 to 10 weight percent of (II); from 0.001 to 10 weight percent, preferably from 0.05 to 3 weight percent of (III); and from 0.01 to 10 weight percent, preferably from 0.1 to 5 weight percent of (IV).
• compositions of the present invention are useful as photoresist materials, such as etch resist and solder mask-coating formulations.
• photoresist materials such as etch resist and solder mask-coating formulations.
• 1 -component or 2-component system can be formulated to provide the photoresist product.
• Examples of a 1 -component system are described in U.S. Patent No. 5,049,628; EP 418011 ; WO 89/07785; and EP 359216.
• Examples of a 2-component system are described in U.S. Patent No. 5,009,982; GB 2,273,707; EP 292219 and EP 306273.
• the coating formulations are applied to substrates as is known in the art.
• the coating formulation (or varnish as sometimes referred) on the substrates, such as metal or circuit board epoxy resin laminates, is cured with an energy curing source, such as UV light, infrared light or heat.
• an energy curing source such as UV light, infrared light or heat.
• the cured coating on the substrate can then be tested for use as a solder mask-coating in electronic applications.
• compositions of the present invention show improvements in higher softening point and higher molecular weight than the unmodified epoxy novolac resins.
• the polyisocyanate modified epoxy-functional resins have been shown to exhibit improved adhesion to the coated substrate and higher photospeed than the unmodified epoxy resins (cresol novolacs or phenol novolac epoxy resins).
• the advanced resins were analyzed for epoxy equivalent weight (EEW), melt viscosity, softening point and glass transition temperature (Tg). Melt viscosity was determined by American Standard Testing Method (ASTM) D4287. Generally, the products of the present invention contain melt viscosities of at least 50 percent higher than unmodified resins.
• the softening point of the resin was determined by Dow Quality Control Method Number RPM 108C; such method is described in a publication readily available from The Dow Chemical Company.
• the Tg of the resin was determined by using a Mettler DSC 30, an apparatus commercially from Mettler Instrument AG (Switzerland), and scanning a sample of the resin using the Mettler DSC 30 at
• the Tg of the resins of the present invention are generally 5°C higher than resins which are not modified according to the present invention, preferably 10°C higher and more preferably 15°C higher than the unmodified resins. In some instances, the Tg of the resins of the present invention can be as much as 50°C higher than the unmodified resins.
• the acrylated, acid functionalized resins produced were analyzed for acid value, solution viscosity and solids content.
• a summary of the resin compositions prepared in the following Examples and their properties are described in Tables I and II.
• Step 1 The Advancement Reaction: General Production Procedure for the
• an epoxy resin for example, a liquid epoxy novolac (LEN) resin such as D.E.N.TM 438 or D.E.N.TM 431 , commercially available from The Dow Chemical Company
• LN liquid epoxy novolac
• MDI methylene diphenyl diisocyanate
• reaction temperature was raised up to at least 150°C (for example, for D.E.N. 438) or 165°C (for example for D.E.N. 431) or 180°C
• Step 2 The Acrylation Reaction: General Production Procedure for the Acrylation of the Advanced Resins
• the advanced resins obtained in Step 1 above were acrylated with acrylic acid as follows:
• the resin solution obtained after advancement in Step 1 above was further diluted with an amount of DOWANOLTM PMA calculated to obtain a constant 75 percent solid solution of epoxy acrylate.
• DOWANOLTM PMA calculated to obtain a constant 75 percent solid solution of epoxy acrylate.
• the nitrogen purge was stopped and replaced by a bubbling of air into the reaction mixture through a glass tube plunger.
• the air flow was started at a rate of 2 to 3 bubbles/second and 400 ppm (based on acrylated solid) hydroquinone inhibitor was added, followed by the required amount of acrylic acid (0.98 mole acid/equivalent epoxy).
• the acrylated resins obtained in Step 2 above were esterified to the half-ester with an anhydride such as methylhexahydrophthalic anhydride (MHHPA) as follows:
• MHHPA methylhexahydrophthalic anhydride
• Steps 1 and 2 The same procedure for the advancement reaction (Step 1) and the acrylation reaction (Step 2) as in Examples 1 to 4 were used for Examples 5 and 6 and the results of these examples are also described in Table I. Comparative Example A
• PAPI 27 Methylene diphenyl diisocyanate, commercially available from The Dow Chemical Company.
• Step 1 The Advancement Reaction: General Production Procedure for the
• an epoxy resin for example, a liquid epoxy novolac (LEN) resin such as D.E.N.TM 438 commercially available from The Dow Chemical Company
• LEO liquid epoxy novolac
• 2,6-DMCH 2,6-dimethylcyclohexylamine
• the reactor was purged with nitrogen to maintain an inert atmosphere.
• An epoxy for example, D.E.N. TM 438, was preheated to 80°C and then 475 g of the preheated epoxy was charged to the reactor and heated to 90°C.
• To the epoxy was added 25 g of 2,6-DMCH via the addition funnel of the reactor under 80 revolutions per minute (rpm) agitation.
• the inside temperature of the reactor was increased to 130°C, and the reaction was continued for 2.0 hours until completion as shown by the epoxy analysis.
• a sample of the resultant solid resin was taken for analysis before the resin was diluted to 75 percent solids with 167 g of a solvent such as DOWANOLTM PMA (Trademark of The Dow Chemical Company). After cooling the resultant resin to 105°C, the resin was ready for further acrylation.
• Step 3 The Esterification Reaction: General Production Procedure for the Esterification of the Acrylated Advanced Resins to the Half-ester
• Step 1 The Advancement Reaction: General Production Procedure for the
• an epoxy resin for example, a liquid epoxy novolac (LEN) resin such as D.E.N.TM 438, commercially available from The Dow Chemical Company
• LEN liquid epoxy novolac
• D.E.N.TM 438 commercially available from The Dow Chemical Company
• an amine compound for example sulfanilamide
• D.E.N.TM. 438 was advanced in molecular weight with sulfanilamide at a weight ratio of 94:6.
• the final theoretical EEW was calculated for complete reaction of the primary amine, as it is known that the amide group reacts with epoxy at a much slower rate and a high temperature.
• the LEN advancement with sulfanilamide was carried out as follows: The reactor was purged with nitrogen to maintain an inert atmosphere.
• An epoxy for example, D.E.N.TM 438, was preheated to 80°C and then 501 g of the preheated D.E.N.TM 438 was charged to the reactor and heated to 105°C. Then 32 g of sulfanilamide powder was slowly introduced into the reactor under 80 rpm agitation until complete dissolution. The inside temperature of the reactor was increased to 130°C, and the reaction was continued for 3.0 hours until the reaction was complete as shown by the epoxy analysis.
• Step 2 The Acrylation Reaction: General Production Procedure for the Acrylation of the Advanced Resins
• the acrylation reaction Step 2 used in this example was the same as in Examples 1 to 6 above.
• the analysis of the resin is given in Table II.
• a 100 mL glass bottle was filled at 95 percent of its volume with the solder mask resin solution, then closed with a screwed cover and, finally placed in a stability oven where the inside temperature was controlled at 50°C ⁇ 1 °C.
• the stability of these two solder mask resin solutions was followed by measuring the viscosity increase versus the initial/starting viscosity every 5 to 10 days interval using the Canon Fenske (C.F.) viscosity method (ASTM-D445): viscosity measurement recorded at 40°C in a temperature controlled water bath.
• solder mask varnish was prepared using the following three resins:
• Part A Two parts of Part A was mixed with 1 part of Part B (all components being dispersed using a ball mill apparatus) to form a solder mask varnish. Test coatings were made from the varnish and the performance of each of the coatings was evaluated.
• Pre-exposure bake Heat each of the panels at 120°C for 5 minutes and then place each panel on a hot plate at 35°C for 10 minutes:
• TEST 1 For tackiness. This test gives plastic rating. A hard rating is required so that image negatives can be placed on the surface of the panels without sticking to the coating during the exposure process.
• TEST 2 methyl ethyl ketone (MEK)-rub resistance on corner of panel. This test gives relative photospeed rating, good MEK-rating after minimal exposure is required; indicating fast photopolymerization.
• the resins of the present invention provide increased speed of greater than 5 percent, and preferably from 10 percent to 50 percent greater than the unmodified resins.
• TEST 3 MEK-rubs. This test provides an indication of the extent of cure/adhesion on a panel substrate.
• TEST 4 Cross-hatch resistance on coated FR-4 boards was carried out using ASTM D 3359-83 Method B. In this test a result of 00 is the best and 55 is the worst. Generally the coatings of the present invention had a cross-hatch resistance of 00 to 11.
• TEST 5 Impact test on coated metal panels (1 kg used, inch ball) was carried out in accordance with ASTM D 2794-84. This test provides a further indication of coating adhesion and integrity on the panel substrate.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Emergency Medicine (AREA)
• Spectroscopy & Molecular Physics (AREA)
• General Physics & Mathematics (AREA)
• Epoxy Resins (AREA)
• Macromonomer-Based Addition Polymer (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=10811423

Family Applications (1)

Country Status (8)

Families Citing this family (6)

Family Cites Families (9)

• 1997
  • 1997-04-25 GB GBGB9708510.4A patent/GB9708510D0/en active Pending
• 1998
  • 1998-04-15 EP EP98918264A patent/EP0977792A1/en not_active Withdrawn
  • 1998-04-15 WO PCT/US1998/007610 patent/WO1998049214A1/en not_active Application Discontinuation
  • 1998-04-15 JP JP54703998A patent/JP2002508787A/ja active Pending
  • 1998-04-15 BR BR9808693-6A patent/BR9808693A/pt not_active Application Discontinuation
  • 1998-04-15 CN CN98805382A patent/CN1257518A/zh active Pending
  • 1998-04-15 KR KR1019997009788A patent/KR20010020207A/ko not_active Application Discontinuation
  • 1998-04-20 ID IDP980588A patent/ID20228A/id unknown

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events