Abstract: A mixture of an adduct of an epoxy resin and a novolak with an acrylate polymer, a modified bisphenol A or a polyol in conjunction with a polyisocyanate or a polyol of an OH-terminated polyurethane or polyester gives a heat-sealing adhesive combining high heat resistance and good hydrolysis stability with relatively high bond strengths. Accordingly, the composition is suitable above all as a base material and cover film for printed circuits.

Abstract: Powdered coating compositions and methods for obtaining improved wrinkled finishes with epoxy powder coatings are provided which utilize a color stabilizer effective to avoid an excessive red color shift upon cure of the composition.

Abstract: Epoxy resin compositions which containa) at least one epoxy resin containing, on average, more than one 1,2-epoxy group per molecule,b) an anhydride hardener for the epoxy resin a),c) a toughener, andd) a compound containing two active hydrogen atoms which is capable of reacting with the epoxy resin a) have an outstanding toughness and are suitable as casting resins, laminating resins, moulding compounds, coating compounds and encapsulation systems for electrical and electronic components.

Abstract: Powdered coating compositions and methods for obtaining improved wrinkled finishes with epoxy powder coatings are provided which utilize curing agents other than commercially available methylenedisalicylic acid.

Abstract: An adhesive is provided for bonding cyanate ester composite parts together which is also plateable with metal once chemically etched. The adhesive comprises a polymeric matrix and a filler of cyanate ester polymer. The polymeric matrix comprises at least one polyepoxide resin and a curing agent, while the cyanate ester polymer filler is present in the adhesive as a powder. In practice, the present adhesive is applied to the surface of cyanate ester composite articles to be bonded and is allowed to cure at room temperature. Thereafter, the surface of the assembly is chemically etched and then plated with metal. The present adhesive enable the complete coverage of the cyanate ester composite assembly with the plated metal, including the adhesive bondlines.

Abstract: This invention relates to thermally-stable, polyglycidyl-terminated polyesters from diglycidyl phthalates and carboxylated polyesters. The resulting resins, when blended and cured with other carboxylated polyesters, are improved binders for powder coating and other applications. The invention also relates to polyglycidyl ester-based powder coating compositions containing these resins.

Abstract: The invention relates to flame-resistant epoxy resin mixtures comprising epoxy resins, phosphorus-containing compounds and a hardener, which comprise a phosphorus-containing compound of the formula I or II ##STR1## in which R is a linear or branched alkyl, cycloalkyl, aryl or alkylaryl group having 1 to 18 carbon atoms or is hydrogen, and R' is a linear or branched alkylene, cycloalkylene, arylene or alkylarylene group having 1 to 18 carbon atoms, to a process for their preparation and to their use.

Abstract: A photocopolymerizable composition for backsealing a ceramic carrier and process for using the composition is disclosed. The composition comprises: a liquid, multifunctional, bisphenol based epoxy; a liquid, multifunctional hydroxyl containing organic material; a complex onium salt photoinitiator; and, a complex cupric salt initiator. The composition utilizes a strong Bronstead acid for additional deep curing created by iodonium salt thermolysis.

Abstract: Modified epoxy resins are obtained by reaction of an epoxy resin with up to one mol equivalent per epoxy group of an alkyl or alkenyl substituted, hydroxy substituted aromatic acid, especially by reaction of a bisphenol A epoxy resin with an alkylated salicylic acid. Also are described a process for the production of such modified resins, curable compositions comprising the modified epoxy resin and products provided with the cured composition, especially in coating applications and civil engineering applications.

Abstract: An increase in the molecular weight of a polyamide or recycled polyamide, essentially without crosslinking, can be achieved by blending said polyamide with a polyfunctional epoxy resin and a sterically hindered hydroxyphenylalkylphosphonic acid ester or half-ester and heating the blend to above the melting point (or the glass transition temperature) of the polyamide, in the absence of a catalyst of the type used in the polymerization of polyamides.

Abstract: An increase in the molecular weight of polyester and recycled polyester can be achieved by blending said polyester with a difunctional epoxy resin and a sterically hindered hydroxyphenylalkylphosphonic acid ester or half-ester and heating the blend to above the melting point (glass transition temperature) of the polyester.

Abstract: A low gloss coating composition having a 60.degree. gloss of less than about 60 which contains:a) a glycidyl group-containing acrylic copolymer;b) an aromatic polyester; andc) an isocyanurate curing agent having the formula: ##STR1## wherein R.sub.1 -R.sub.3 are independently selected from the group consisting of divalent alkylene groups of 1 to 18 carbon atoms and divalent groups of 3 to 21 carbon atoms and containing an ester linkage, and R.sub.4 -R.sub.6 are independently selected from the group consisting of H, organic salt groups, alkyl groups of 1 to 20 carbon atoms and C(O)R.sub.7 wherein R.sub.7 is an alkyl group of 1 to 22 carbon atoms.

Abstract: A stable aqueous emulsions of epoxy resins are provided using an epoxy-functional polyether having the formula: ##STR1## wherein R.sup.1 is a C.sub.1 -C.sub.15 alkyl, aryl or alkylaryl group, R.sup.2 is a divalent aliphatic group, a divalent cycloaliphatic group, a divalent aryl group, or a divalent arylaliphatic group, R.sup.3 is independently a hydrogen or a C.sub.1 -C.sub.10 alkyl group, R.sup.8 is a divalent aliphatic group optionally containing ether or ester group(s) or together with R.sup.9 or R.sup.10 form a spiro ring optionally containing heteroatoms, and R.sup.9 and R.sup.10 are independently hydrogen or R.sup.9 or R.sup.10 together with R.sup.

Abstract: A process for curing epoxidized diene polymers for use in adhesives, sealants, and coatings which comprises contacting the polymer with an aromatic anhydride curing agent at an epoxy/anhydride molar ratio from 0.5/1 to 2.0/1.0, optionally, and from 0.1 to 10 phr of an accelerator at a temperature of from 100.degree. to 200.degree. C. for a period of 10 minutes to six hours.

Abstract: Disclosed are a carbonate group-modified epoxy resin in which carbonate groups are introduced into an epoxy resin having secondary hydroxyl groups at terminals or lactone-modified epoxy resin having primary hydroxyl groups at terminals by the ring-opening reaction of a cyclic alkylene carbonate, a process for the preparation thereof, and a thermosetting resin composition containing the carbonate group-modified epoxy resin.

Abstract: The present invention relates epoxy(meth)acrylates which are substantially free from epoxide groups and are the reaction products of organic compounds containing epoxide groups and having a number average molecular weight (M.sub.n) of 130 to 1000 withI) compounds containing carboxyl and ester groups at an equivalent ratio of carboxyl groups to epoxide groups of 0.7:1.0 to 1.0:1.0, wherein compounds I) are reaction products ofA) organic dicarboxylic acids or dicarboxylic acid anhydrides having a molecular weight of 98 to 164 withB) reaction products containing alcoholic hydroxyl groups and prepared at a COOH/OH equivalent ratio of 0.6 to 0.95 froma) (meth)acrylic acid andb) tri- or tetrahydric ether alcohols having a molecular weight of 180 to 1000, which contain at least two ethylene oxide units --CH.sub.2 --CH.sub.2 --O-- as part of one or more ether structures and which contain up to 20 mole %, based on the total moles of alkylene oxide units, of propylene oxide units, --CH.sub.2 --CH(CH.sub.

Abstract: In coating compositions based on a low molecular weight anhydride resin having pendant non-cyclic anhydride moieties, epoxy resin containing glycidyl methacrylate and catalyst, the use of branched epoxy resin provides an improved balance of performance characteristics.

Abstract: The present invention relates to an auxiliary agent for use in the synthesis of unsaturated polyester resins comprising a compound of the general formulaBCOO--A--COOB'and at least one compound selected from the group consisting of fatty acid amides, fatty acid divalent metal salts and their mixtures, whereby styrene emissions from unsaturated polyester resins are suppressed.

Abstract: The invention relates to water-dispersible binders for cationic electrocoating finishes, which binders are reaction products of(A) low molecular weight epoxide resins containing aromatic groups and having an epoxide equivalent weight of below 375,(B) aliphatic and/or alicyclic polyfunctional alcohols and/or carboxylic acids having a molecular weight of below 350,(C) if appropriate up to 60% by weight, relative to the total binder, of polyfunctional alcohols, carboxylic acids and/or SH compounds having a molecular weight of 500-5,000 and(D) primary, secondary and/or tertiary amines and/or salts thereof or a sulfide/acid mixture or a phosphine/acid mixture, the reaction product of A and B containing 10-45% of aromatic groups, calculated as the phenylene group. By means of the binders, a higher layer thickness is obtained in electrocoating.

Abstract: The present invention relates to an epoxy composition that is isolated in the form of an infusible, gelled, heat curable, epoxy functional reaction product. The reaction product is formed by mixing together: (A) one or more epoxy resins or epoxy group containing compounds and (B) a hardener system which will react with (A) to give a gelled solid, but which does not cause complete curing of (A) under the reaction conditions chosen for reaction of (A) and (B) to give a gelled solid. The reaction product can be formed by including (C) an optional further hardener system for (A) and the reaction product of (A) and (B), which is different from (B), and which remains largely unreacted with (A) and (B) under said reaction conditions. The present invention further relates to a cured product of said epoxy composition.

Abstract: There is disclosed a photo-imaging resist ink containing (A) an unsaturated group-containing polycarboxylic acid resin which is a reaction product of (c) succinic anhydride with an additive reaction product of (a) an epoxy resin with (b) an unsaturated group-containing monocarboxylic acid, wherein (a) the epoxy resin is represented by the following formula (1): ##STR1## wherein M stands for ##STR2## n is at least 1 on the average; and m is 1 to n on the average. The resist ink is excellent in developability and photosensitivity, while the cured product thereof is excellent in flex resistance and folding resistance, and well satisfactory in adhesion, pencil hardness, solvent resistance, acid resistance, heat resistance, etc.

Abstract: The use of an amine salt of trifluoromethanesulfonic acid as a catalyst for the curing of hydroxyl-functional resins provides a wrinkle finish. The hydroxy-function may be present in polyesters, epoxies, and acrylate or methacrylate resins, among others. The polyester resins which are able to provide such a finish have a hot plate melt flow of at least about 50 mm but if it is more than 150 mm, the gel time of the resin must not be more than about 280 seconds. The minimum gel time in the case of polyesters is about 30 seconds.

Abstract: A coating composition applied to a substrate, the composition containing a solids content of at least about 65 percent by weight and including a polyanhydride having more than one non-cyclic moiety, a co-reactant resin such as a glycidyl (meth)acrylate-containing polymer, and a latent catalyst, wherein the equivalent ratio of epoxy to anhydride groups is from about 0.8:1 to 1.3:1.

Abstract: A coating composition applied to a substrate wherein the composition contains a solids content of at least about 65 percent by weight and includes a polyanhydride having more than one non-cyclic anhydride moiety, a glycidyl groups-containing oligomer, a catalyst and a surfactant or flow-control agent.

Abstract: The use of an amine salt of trifluoromethanesulfonic acid as a catalyst for the curing of hydroxyl-functional resins provides a wrinkle finish. The hydroxy-function may be present in polyesters, epoxies, and acrylate or methacrylate resins, among others. The polyester resins which are able to provide such a finish have a hot plate melt flow of at least about 50 mm but if it is more than 150 mm, the gel time of the resin must not be more than about 280 seconds. The minimum gel time in the case of polyesters is about 30 seconds.

Abstract: In a method for curing a resin by utilizing an intramolecular crosslinking reaction, the improvement wherein the crosslinking reaction is a ring opening addition reaction between a lactone structure and an active hydrogen-containing functional group.

Abstract: A thermosetting anti-reflective coating and method for making and using the same is disclosed for a broad range of exposure wavelengths, said coating containing an active curing catalyst, ether or ester linkages derived from epoxy functionality greater than 3.0, a dye-grafted hydroxyl-functional oligomer, and an alkylated aminoplast crosslinking agent, all present in a low-to-medium alcohol-containing solvent.

Abstract: Powdered coating compositions and methods for obtaining improved wrinkled finishes with epoxy powder coatings are provided which utilize curing agents other than commercially available methylenedisalicylic acid.

Abstract: Disclosed are an epoxy acrylate resin of the general formula (1) ##STR1## and an acid-modified epoxy acrylate resin obtained by reacting the epoxy acrylate resin with a carboxylic acid or an anhydride thereof, as well as curable resin compositions containing such a resin and the cured products thereof.

Abstract: There are herein disclosed a method for preparing a modified resin which comprises thermal/reaction by the use of a norbornenyl group-containing compound typified by norbornenecarboguanamine or its derivative, a method for preparing an epoxy-modified resin which comprises the step of reacting the above-mentioned modified resin and an epoxide, a flame-retarding method, a thermal stabilization method, a compatibilizing method and a surface modification method which comprise utilizing the modified resin, as well as a coating resin composition and an adhesive resin composition containing the modified resin. According to the, preparation methods of the present invention, the deterioration of a material scarcely occurs, and a functional group which is excellent in flame retardancy, thermal stability, compatibility and the like can be introduced to the resins.

Abstract: A hyperbranched macromolecule of polyester type comprising a central monomeric or polymeric nucleus and at least one generation of a branching chain extender having at least three reactive sites of which at least one is a hydroxyl or hydroxyalkyl substituted hydroxyl group and at least one is a carboxyl or terminal epoxide group. The nucleus is an epoxide compound having at least one reactive epoxide group. Optionally, the macromolecule comprises at least one generation consisting of at least one spacing chain extender having two reactive sites of which one is a hydroxyl or hydroxyalkyl substituted hydroxyl group and one is a carboxyl or terminal epoxide group. The macromolecule may be terminated by means of at least one chain stopper.

Abstract: A thermosetting resin composition comprising:[A] a polyfunctional epoxy resin produced from a reaction between a mixture of at least two polyhydric phenols selected from (a) bis(4-hydroxyphenyl)methane, (b) bis(4-hydroxyphenyl)ethane, (c) bis(4-hydroxyphenyl)-propane, (d) tris(4-hydroxyphenyl)alkane and (e) tetra(4-hydroxyphenyl)alkane, and epichlorohydrin, and[B] an acid anhydride curing agent; and a coil and a panel formed of said composition.

Abstract: The invention relates to powder coatings which are characterized in that they contain as film-forming material a mixture of(A) from 19.9 to 90.0 percent by weight of a synthetic resin which contains epoxide groups and may contain ethylenically unsaturated double bonds, or of a mixture of such epoxide group-containing synthetic resins,(B) from 9.9 to 80.0 percent by weight of a compound which contains carboxyl groups and may contain ethylenically unsaturated double bonds, or of a mixture of such carboxyl group-containing compounds,(C) from 0 to 20 percent by weight of a compound which contains ethylenically unsaturated double bonds and is different from (A) and (B), or of a mixture of such compounds, and(D) from 0.1 to 3.0 percent by weight of an initiator for free-radical polymerizations or of a mixture of initiators for free-radical polymerizations,the percentages by weight of (A)+(B)+(C)+(D) being=200% by weight and the mixture of components (A), (B), (C) and (D) containing from 0.1 to 6.

Abstract: A curable coating composition is described comprising two components that are reactive with one another upon curing to form urethane linkages. The urethane-forming components are an active hydrogen groups-containing component and a polyisocyanate, or a carbamate groups-containing component and a carbamate group-reactive component. The composition further comprises a third component that includes one or more epoxide groups. Coatings prepared with this coating composition can be cured and coated with additional coating(s), providing good intercoat adhesion to the subsequent coating.

Abstract: Polyepoxide-polyamine gas barrier coatings for use on packaging materials such as polymeric containers are provided with low permeability at relatively low amine to epoxy cure ratios by including substantial aryloxy or aryloate group content. The aryloxy or aryloate content may be provided, for example, by polyglycidyl ether of resorcinol or polyglycidyl ester of phthalic acid.

Abstract: A coating composition with a solids content of at least about 65% by weight comprises a polyanhydride having more than one non-cyclic anhydride moiety, a co-reactant resin such as a glycidyl (meth)acrylate-containing polymer and a latent catalyst wherein the equivalent ratio of epoxy to anhydride is from about 0.8:1 to 1.3:1.

Abstract: A coating composition with a solids content of at least about 65% by weight comprises a polyanhydride having more than one non-cyclic anhydride moiety, a glycidyl groups-containing oligomer, a catalyst and a surfactant or flow-control agent.

Abstract: A modified liquid epoxy resin composition is provided by reacting a crystalline epoxy resin, from about 3 to about 20 parts by weight, based on the epoxy resin, of a compound having two or more phenolic hydroxyl groups and/or carboxyl groups in one molecule and from about 3 to about 20 parts by weight of a compound having one phenolic hydroxyl group or carboxyl group in one molecule. The crystalline epoxy resin is preferably selected from various glycidylethers of biphenol compounds. The modified liquid epoxy resin composition has a low viscosity and good liquid stability at low temperatures, resulting in cured resins having excellent heat resistance and water resistance.

Abstract: A novel epoxy-functional hydroxy ester composition is produced by reacting (a) dimethylolpropionic acid and (b) an aliphatic or cycloaliphatic glycidyl ether, an epoxy novolac or a cycloaliphatic epoxy having a functionality of at least about 1.5 epoxide group per molecule.

Abstract: A resin composition is provided that is suitable for impregnating sheet material, including fabrics, films, paper and tapes of the type employed to form prepregs, such as tapes used to form electrical insulation layers on electrical components. The resin composition includes a solid or semi-solid epoxy resin having an epoxide functionality of at least 2.5, a metal acetylacetonate for catalyzing the epoxy resin, and an accelerator of bisphenol A-formaldehyde novolac catalyzed by an acidic catalyst and having a hydroxyl equivalent weight of 120. The resin composition is essentially unreactive at room temperature and at elevated temperatures sufficient to enable permeation of the sheet material by the resin in its manufacture, is essentially unreactive at temperatures required to remove moisture and volatiles during processing of articles wrapped or taped with the sheet material, and cures at a higher temperature without adversely affecting the cure characteristics of the resin composition.

Abstract: A curing agent for a composition useful for the production of matt epoxy resin and hybrid powder coatings, comprising a mixture ofa) salts of phthalic acid, isophthalic acid and terephthalic acid with the following amines ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 are identical or different aliphatic, cycloaliphatic, araliphatic or aromatic hydrocarbon radicals having 1-20 carbon atoms and in which one or more CH.sub.2 groups in the carbon chain may be replaced by 0 atoms, by NR.sub.4 groups where R.sub.4 =C.sub.1-6 -alkyl, CH--OH groups, and/or one or more terminal methyl groups may be replaced by dialkyl-substituted amino groups having 1 to 6 carbon atoms, and R.sub.1 and R.sub.2 may form a joint ring in which one CH.sub.2 group may be replaced by an O atom or by an NR.sub.4 group, and R.sub.1 =R.sub.2 =R.sub.3 --CH.sub.2 --CH.sub.2 -- attached via a common nitrogen atom, and n=3-11, and 0.5-2 mol of amine A)-C) per mole of acid, andb) pyromellitic acid and/or trimellitic acid, 0.

Abstract: The invention relates to a substantially solventless curable resin composition, in particular for the fabrication of prepregs, which contains more than 45% by weight of substances which are solid at ambient temperature at least or at lower temperature, and which, in addition to comprising customary modifiers, comprises solid epoxy resins or a mixture of liquid and solid epoxy resins, at least one initiator which is sensitive to UV radiation for the polymerisation of the epoxy resins and has the formula I ##STR1## wherein a and b are each independently of the other 1 or 2, R.sup.1 ist a .pi.-arene, R.sup.2 is a .pi.-arene, an indenyl anion or a cyclopentadienyl anion, [X].sup..crclbar. is an anion [LQ.sub.m ].sup..crclbar.

Abstract: A thermosetting in-mold coating for molded fiber-reinforced plastic parts is disclosed. The binder for the thermosetting coating is comprised of least one polymerizable epoxy-based oligomer having at least two acrylate groups and at least one copolymerizable ethylenically unsaturated monomer. The coating includes graphite and titanium dioxide which results in the gray color. The coating composition has good flow and coverage during molding, good adhesion, uniform color, good surface quality, and good paintability. The coating composition includes enough carbon black so that a 1.0 mil thick coating has a Ransburg conductivity meter reading of at least 165 units.

Abstract: A fiber-reinforced resin composition, which comprises:an epoxy resin having at least two epoxy groups in the molecule,a polymerizable unsaturated group-containing epoxy compound of the following general formula [I], ##STR1## wherein R.sup.1 is H or CH.sub.3, R.sup.2 is an alkylene group having 1 to 20 carbon atoms, and n is an integer of 0 to 20,a liquid carboxylic acid anhydride containing a monofunctional carboxylic acid anhydride and/or a polyfunctional carboxylic acid anhydride obtained by reacting a lower aliphatic polyhydric alcohol with a trimellitic acid or a derivative thereof,a curing promoter,a radical polymerization initiator, anda fiber,the glass transition temperature (Tg, .degree.C.) and breaking strain (E, %) of a cured product of said composition satisfying the following formulae:Tg.gtoreq.-17E+240E.gtoreq.4, andTg.gtoreq.125.

Abstract: Aqueous epoxy resin dispersion comprising (A) an epoxy resin which is a condensation product of (A-1) from 50 to 95% by weight, preferably from 55 to 85% by weight, of one or more epoxide compounds having at least two epoxide groups per molecule and an epoxide equivalent mass of from 100 to 2000 g/mol, (A-2) from 5 to 50% by weight, preferably from 15 to 45% by weight, of an aromatic polyol; and (A-3) from 0 to 25% by weight, preferably from 0 to 10% by weight, of modifying compounds containing at least two epoxide-reactive groups; (B) a dispersant comprising (B-1) a condensation product of a polyol having a weight-average molecular mass (M.sub.

Abstract: The invention relates to salts of pyromellitic acid which comprise 1 mol of pyromellitic acid and 0.5 to 2 mol of a guanidine of the following composition: ##STR1## in which R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different radicals from the group consisting of hydrogen, alkyl, cycloalkyl and aromatic hydrocarbon residues having 1 to 8 carbon atoms, and R.sup.1 and R.sup.2 and R.sup.3 and R.sup.4 may form a joint ring which may contain an oxygen atom as heteroatom. Also claimed are the preparation of the salts and their use for matt epoxide and hybrid powder coatings.

Abstract: The present invention relates to a powder coating, in particular for internal coating of packaging containers, which is characterized in that it1.) comprises at least one epoxy resin having an epoxide equivalent weight of from 300 to 5500 and at least one hardener having more than one phenolic hydroxyl group per molecule and a hydroxyl equivalent weight, based on the phenolic OH groups, of from 100 to 500, and2.) has a particle size distribution such that at least 90 percent by weight of the powder coating particles have a particle size of between 1 and 60 .mu.m, the maximum particle size of the powder coating particles is .ltoreq.100 .mu.m, the mean particle size of the powder coating particles is between 5 and 20 .mu.m and the gradient of the particle distribution curve at the point of inflexion is .gtoreq.100.

Abstract: A stable aqueous emulsions of epoxy resins are provided using an epoxy-functional polyether having the formula: ##STR1## wherein Q is A or B, R.sup.1 is independently a divalent hydrocarbon group, R.sup.2 is a divalent aliphatic group optionally containing ether or ester groups or together with R.sup.3 or R.sup.4 form a spiro ring optionally containing heteroatoms, and R.sup.3 and R.sup.4 are independently hydrogen or R.sup.3 or R.sup.4 together with R.sup.2 form a spiro ring optionally containing heteroatoms such as oxygen, X and Y are independently hydrogen, methyl or ethyl group with the provision that if X is methyl or ethyl, Y is hydrogen or if Y is methyl or ethyl, X is hydrogen and n+m+o is a positive real number from about 15 to 450, and where Q is B, n+o is a real number in an amount effective to provide emulsifying property.

Abstract: A novel polyester composition is disclosed comprising a linear polyester resin, a difunctional epoxy compound and a catalyst. The novel polyester compositions have excellent melt viscosity properties including excellent retention of melt viscosity after aging.

Abstract: An adhesive composition is here disclosed which comprises a 2-cyanoacrylate and at least one of compounds (a) and (b):(a) an addition reaction product of an epoxy group and a compound having a cyano group and a carboxylic acid group in its molecule, and(b) a compound having a cyano group and a carboxylic acid group in its molecule. A process for preparing the adhesive composition is also disclosed herein. According to the present invention, the 2-cyanoacrylate-based adhesive composition can be obtained which is excellent in storage stability and hardening properties of thick films and which has a high hardening rate and remarkably improved surface hardening properties of the adhesive composition itself bulged from between adherends. Particularly, the 2-cyanoacrylate bulged from between the adherends can harden rapidly, so that the vaporization of the 2-cyanoacrylate can be minimized.