Abstract: A phenol resin for a wet friction material of the invention contains a resol-type phenol resin having, in one molecule, a structural unit A which is derived from a phenol compound having one phenolic hydroxyl group and a structural unit B which is derived from a polyfunctional phenol compound having two phenolic hydroxyl groups.

Abstract: A polycondensation product based on aromatics and/or heteroaromatics and aldehydes, the polycondensate containing at least one structural unit (I) having a polyisobutylene side chain and an aromatic or heteroaromatic and at least one structural unit (II) having an ionizable functional group and an aromatic or heteroaromatic, structural unit (I) not being the same as structural unit (II) and the aldehyde used having no acid or ester functions. A process for the preparation and the use as an additive for hydraulic binders are disclosed.

Abstract: Proposed is a polycondensation product comprising as monomer components at least one aryl polyoxyalkylene ether, at least one vicinally disubstituted aromatic compound, at least one aldehyde and also optionally further aromatic compounds; processes for preparing same, and also use thereof as dispersant for aqueous suspensions of inorganic binders and as grinding assistant for inorganic binders.

Abstract: An enhanced prepreg for printed circuit board (PCB) laminates includes a substrate and a resin applied to the substrate. The resin includes a curable polymer and a polymerization initiator polymer having a backbone with a free radical initiator forming segment that breaks apart upon being subjected to heat to generate a plurality of non-volatile initiating species. This resin composition eliminates possible volatile loss of the free radical initiator during all processing steps in the preparation of PCB laminates. The resin may additionally include a cross-linking agent, flame retardant and viscosity modifiers. In one embodiment, a sheet of woven glass fibers is impregnated with the resin and subsequently dried or cured. The glass cloth substrate may include a silane coupling agent to couple the resin to the substrate. In another embodiment, resin coated copper (RCC) is prepared by applying the resin to copper and subsequently curing the resin.

Abstract: Disclosed is a polycondensation product that is a reaction product of A) an aromatic or heteroaromatic compound containing 5 to 10 C atoms or heteroatoms and is provided with an average of 1 to 300 oxyethylene groups and/or oxypropylene groups per molecule which are linked to the aromatic or heteroaromatic compound via an O atom or N atoms, and B) an aromatic compound and C) an aldehyde selected among the group of formaldehyde, glyoxylic acid, and benzaldehyde or mixtures thereof. Surprisingly, the inventive polycondensation product causes very good liquefaction of hydraulic binding agents, eg. Cement, resulting in substantially improved liquefaction of the construction material at a lower dose while pourability can be maintained over a longer period of time as opposed to naphthalene sulfonates or melamine sulfonates.

Abstract: The present invention provides a phenol resin composition which imparts excellent heat resistance and flame retardancy in a cured article, the cured article, a resin composition for a copper-clad laminate, and a copper-clad laminate having both excellent heat resistance and flame retardancy. Disclosed is a phenol resin composition comprising a phenol resin (I) having a chemical structure (A) represented by structural formula (1) shown below in which an aromatic hydrocarbon group substituted with a carboxyl group is bonded to a triazine ring, as a partial structure in the molecular structure, and a curing agent (II) as essential components.

Abstract: The present invention provides a polymer electrolyte composition excellent in radical resistance and/or proton conductivity. The polymer electrolyte composition comprises an aromatic polymer phosphonic acid derivative represented by the following formula (1); and at least one selected from the group consisting of a phosphoric acid derivative and a polymer electrolyte. (wherein -Z- represents —SO2— or —CO—, x and y each represent 0.01-0.99 provided that the sum of x and y is 1, —Ar— represents a divalent aromatic group of 4-18 carbon atoms which may contain a hetero atom and may contain one or more substituents, n represents the average number of substituents per unit structure of polymeric moiety containing the aromatic group and is a positive number of 8 or less, and R and R′ each independently represent a hydrogen atom or an alkyl group).

Abstract: A polyester resin composition comprising 50 equivalents/ton or more of an aromatic ring in the resin and at least one thermosetting resin selected from the group consisting of melamine resin, urea resin, benzoguanamine resin and phenol resin. The aromatic ring in the polyester resin has a phenolic hydroxyl group and at least one of ortho-position and para-position of the aromatic ring to the phenolic hydroxyl group is a hydrogen atom. The resin composition has excellent toughness at ambient temperature and heat resistance.

Abstract: Disclosed is a method for producing low molecular weight oligomers of a film forming resin, which involves: a) providing a solution of the film forming resin in a first solvent system comprising a photoresist solvent, and optionally a water-soluble organic solvent; b) providing a second solvent system comprising at least one substantially pure C5-C8 alkane and/or at least one aromatic compound having at least one hydrocarbyl substituent and/or water/C1-C4 alcohol mixture; and performing steps c)-e) in the following order: c) mixing the solutions from a) and second solvent system from b) in a static mixer for a time period sufficient for efficient mixing; d) feeding the mixture from c) and second solvent system from b) through two separate inlet ports into a liquid/liquid centrifuge, one of the inlet ports feeding the mixture from c), the second inlet port feeding the second solvent system from b) into said liquid/liquid centrifuge at a feed ratio of the mixture from c) to the second solvent system from b) of

Abstract: The invention provides a novel polymer in the form of a novolac resin in which some of the hydrogen atoms of the hydroxyl groups are replaced by 1,2-naphthoquinonediazidosulfonyl ester groups and some of the hydrogen atoms of the remaining hydroxyl groups are replaced by substituted carbonyl or sulfonyl groups. The polymer has a weight average molecular weight calculated as polystyrene of 1,000-30,000. The polymer is formulated into a resist composition having improved uniformity, sensitivity, resolution and pattern geometry in microfabrication.

Abstract: A radiation sensitive resist composition with high sensitivity, capable of forming a highly heat-resistant resist pattern. The radiation-sensitive resist composition contains, together with a resist material, a polymer which is obtained by reacting (a) a xylylene compound, (b) salicylic acid and (c) 9,9'-bis(hydroxyphenyl)fluorene derivatives or diol compounds of 3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene, and which has a weight average molecular weight of 1,000 to 5,000 and Tg of 100 to 150.degree. C. Examples of (c) include 9,9'-bis(4-hydroxyphenyl)fluorene and 3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol. As the resist material, any of positive- and negative-working resists may be used, with that comprising an alkali-soluble resin and a quinonediazide photo-sensitizer being preferably used.

Abstract: The invention is directed to purification of phenolic resins and to a process for preparing an organic photoresist coating composition. The process comprises reacting one or more phenols to form a crude phenolic resin. The crude phenolic resin formed is then separated from its reaction mixture and dissolved in an aqueous insoluble organic solvent in an organic solvent that is a solvent for the photoresist coating composition. The solution so formed is then mixed with an aqueous phase to extract water soluble impurities from the resin solution into the aqueous phase. Finally, the purified resin solution is further diluted with additional photoresist solvent.

Abstract: Dental resins and dental compositions utilizing such resins are described. The dental compositions are particularly useful as cavity liners and root canal sealants which contain calcium hydroxide (or calcium oxide) and which are utilized to deliver calcium to exposed dental pulp. The resins, and resin-containing compounds, include eutectic mixtures of polyfunctional salicylates. In particular, the transesterification of a blend of trimethylolpropane and neopentylglycol with methyl salicylate yields a blend of trimethylolpropanetrisalicylate and neopentylglycoldisalicylate, which is contemplated by the present invention.

Abstract: Weatherable polycarbonate compositions (formulations or blends) comprise polycarbonate, cycloaliphatic polyester resins, at least one of a benzotriazole, benzophenone, and triazine based UVA, and a catalyst quencher. The incorporation of the cycloaliphatic polyester resin and the benzotriazole, benzophenone, and triazine based UVA exhibits a synergistic effect, thereby resulting in unexpected enhanced protection of the polycarbonate compositions by imparting photostability to the polycarbonate formulations, thereby reducing yellowing or other forms of light induced degradation.

Abstract: A method for the removal, separation, and concentration of cesium cations from a source solution which may contain larger concentrations of other alkali metal ions comprises bringing the source solution into contact with a polymeric resin containing poly(hydroxyarylene) ligands. The poly(hydroxyarylene) ligand portion(s) of the polymeric resins has affinity for cesium, thereby removing cesium from the source solution. The source solutions from which the cesium has been removed may then be treated or disposed of as desired and the cesium cations are then removed from the polymeric resin through contact with a much smaller volume of a receiving solution in which these cesium cations are soluble and has greater affinity for such cations than does the poly(hydroxyarylene) ligand or protonates the ligand, thereby quantitatively stripping the completed cesium cations from the ligand and recovering them in concentrated form in said receiving solution.

Abstract: A process for hardening a composition and a hardenable composition, in wh there are used:at least one novolac resin;at least one hardener of the resin, selected from the group consisting of substituted melamines;at least one compound comprising at least one ##STR1## group, this compound being without methylol group and ether group corresponding to methylol, and/or at least one reagent capable of giving such a compound under the conditions of the hardening.The hardening of the resin is caused by the action of heat.

Abstract: A processes for producing a (co)polycarbonate having a low terminal hydroxyl group concentration and being excellent in heat resistance and hue, which comprises melt-polycondensing a dihydroxy compound with a carbonic diester in the presence of a catalyst for transesterification selected from the group consisting of a nitrogen-containing basic compound, an alkali metal borate and an alkaline earth metal borate and in the presence of a specific ester compound.

Abstract: In a novel method of homo- or copolymerization of vinyl chloride, a specified coating agent is applied on the surfaces of the portions which will become into contact with the vinyl chloride monomer during the polymerization process. The coating agent is in a form of an aqueous solution of a modified condensation product of phenol and aldehyde, the pH of the solution being adjusted in a range that the product is dissolved at an ambient temperature upon coating of the solution and separates out of the solution upon being heated on the surfaces. The wall surface of the polymerization tank and the like is then coated with a thin film of the coating agent having a uniform thickness and being strongly adhered to the wall surface, thereby providing an excellent effect of preventing adhesion of the product polymer to the wall surface.

Abstract: A biologically active polymeric compound comprising an alkylaryl or heteroalkylaryl backbone having about 5 to about 50 repeating aromatic ring-containing units and which, according to the computer program marketed as SYBYL.RTM. version 5.2 running on a DEC VAX.RTM. 11/750 computer, is capable of forming a linear backbone having a helical secondary structure, and wherein the maximum diameter of the helical structure, as measured by the alkylaryl or heteroalkylaryl backbone, is less than 3 times greater than the maximum diameter of the aryl group of the alkylaryl or heteroalkylaryl backbone.

Abstract: Polyamide-containing fibre materials can be given an anti-stain finish by treating them with a sulpho-containing aromatic formaldehyde condensation product in combination with polyacrylic acid, the treatment with the two components being carried out in any desired order or simultaneously.

Abstract: A method for the removal separation, and concentration of cesium cations from a source solution which may contain larger concentrations of other alkali metal ions comprises bringing the source solution into contact with a polymeric resin containing poly(hydroxyarylene) ligands. The poly(hydroxyarylene) ligand portion(s) of the polymeric resins has affinity for cesium, thereby removing cesium from the source solution. The source solutions from which the cesium has been removed may then be treated or disposed of as desired and the cesium cations are then removed from the polymeric resin through contact with a much smaller volume of a receiving solution in which these cesium cations are soluble and has greater affinity for such cations than does the poly(hydroxyarylene) ligand or protonates the ligand, thereby quantitatively stripping the complexed cesium cations from the ligand and recovering them in concentrated form in said receiving solution.

Abstract: A process for the production of modified phenol-aldehyde resins includes the use of a modifier selected from melamine, urea, and other suitable nonvolatile organic compounds. The phenolic component of the resins preferably includes a difunctional phenolic compound. The inventive resins resist precuring and are particularly useful in blowline blending procedures.

Abstract: Novel aminoplast anchored UV stabilizers are provided. Compared to unanchored stabilizers, the anchored stabilizers disclosed herein have increased compatibility with coating resins and have reduced volatility due to higher molecular weights resulting from anchoring. A process for preparing the anchored stabilizers by the reaction of unanchored stabilizers with alkoxymethylated aminoplasts in a sulfuric acid medium is also provided. The unanchored stabilizers include 2-(2-hydroxyaryl)benzotriazoles, 2-hydroxybenzophenones, 2-(2-hydroxyaryl)-4,6-diaryl-1,3,5-triazines, salicylic acid derivatives, 2-hydroxyoxanilides, and blocked derivatives thereof as well as mixtures of two or more stabilizers. The aminoplasts include alkoxymethylated derivatives of glycolurils, melamines, and benzoguanamines.

Abstract: This invention relates to aromatic oligomeric compounds useful in the treatment of cardiovascular, bone metabolic, hypolipidaemic, neuronal, gastrointestinal and elastase-mediated connective tissue degradation disorders and disorders which may be treated by agents effective in binding DNA, to processes for preparation of such oligomeric compounds, to pharmaceutical compositions including such oligomeric compounds, and to their use in the treatment of such disorders.

Abstract: The invention relates to a process for the preparation of a phenol-formaldehyde resin by causing phenol and formaldehyde to condense under the influence of a basic catalyst, the catalyst being an aqueous solution containing alkali metal ions, carbonate ions, ions of carboxylic acids and one or more ions chosen from the group comprising transition metal ions and borates.

Abstract: The aromatic formaldehyde condensation products, which are substantially colorless and water-soluble and contain sulphonate and/or carboxylate groups, are obtainable by adding agents which have a reducing action during and/or after the condensation reaction, and are suitable for the treatment of textiles and leather.

Abstract: A process for preparing a polymeric composition comprising reacting a mixture of at least one phenolic compound and at least one oxazoline compound in the presence of a catalytic amount of at least one ammonium salt and a tetracarbyl phosphonium salt, and optionally also in the presence of an alkyl halide is described.

Abstract: A process for producing a branched polycarbonate comprising reacting a dihydric phenol, such as 2,2-bis(4-hydroxyphenyl) propane, a polyfunctional organic compound, such as 1,1,1-tris-(4-hydroxyphenyl)ethane, and phosgene to produce a polycarbonate oligomer, and then polycondensing with stirring the polycarbonate oligomer with a dihydric phenol, such as 2,2-bis(4-hydroxyphenyl) propane, and a monohydric phenol, such as p-tert butylphenol, whereby the interfacial area of the resultant emulsion is not less than 40 m.sup.2 /L.

Abstract: A polyester for electrophotography derived from(a) at least one component selected from tri- or tetra-basic acid components and tri- or tetra-hydric alcohols;(b) at least one component selected from dibasic carboxylic acids and lower alkyl esters thereof; and(c) at least one component selected from aromatic diols and alicyclic diolswherein the proportion of x (mole %) of component (a) to the whole acid components and the proportion y (mole %) of component (c) to the whole acid components satisfies the following formulae (1) and (2):y<(133m+51.5n) log x+(60m+25.43n) (1)y>(253m+170n) log x-(176m+162n) (2)wherein 0<y<100, 0.5<x<50 0.ltoreq.y.ltoreq.100, 0.5.ltoreq.x.ltoreq.50, m is a proportion of the tetrabasic acid or alcohol in component (a) (mole %), n is a proportion of the tribasic acid or alcohol in component (a) (mole %), and m+n=1. The polyester possesses a good resistance to off-setting and good grinding characteristics.

Abstract: An essentially aromatic alkali soluble novolak resin comprising the product resulting from the acid condensation of an aromatic aldehyde and a phenol where the resin has a molecular weight in excess of 1500 and a glass transition temperature in excess of 125.degree. C. If desired, the aromatic novolak resin may be blended with a conventional novolak resin to regulate the glass transition temperature of the resin. The aromatic novolak resin and blends formed therefrom are especially suitable as coating resins and are useful for the formation of photoresist coating compositions.

Abstract: A novel calixarene derivative, viz. acetylated methyl-calix[n]arene (n is from 4 to 8), exhibits high solubilities in various organic solvents. A film of this compound can easily be formed by a conventional solution coating method such as spin coating, and the obtained film is hard and heat-resistant. A pattern of negative type can be formed in the obtained film by selectively irradiating the film with a high-energy ray such as ion beam, electron beam or X-ray to polymerize and insolubilize the irradiated regions and then removing the unirradiated region by dissolution in an organic solvent.

Abstract: The invention is a solution of highly advanced phenolic resin with improved inherent foamability that is made from the reaction of phenol, aldehyde, water and alkali the improved foamability being brought about by the incorporation of up to 1.0% by weight, anhydrous basis, lime (calcium hydroxide) into the early stages of the reaction mix. In another embodiment, the invention is a plywood glue composition comprising a solution of lime-containing highly advanced phenolic resin, dried animal blood and preferably an aldehyde glue viscosity-lowering agent.

Abstract: Novel thermosetting imido prepolymers having low melt viscosity, well adapted for the production, e.g., of preimpregnated shaped articles, are copolymerizates of at least one N,N'-bismaleimide; at least one hindered diprimary diamine, e.g., 4,4'-diamino-3,3',5,5'-tetraalkyl-diphenyl-methane or 1,3-diamino- or 1,4-diaminotrialkylbenzene; at least one comonomeric heterocycle, e.g., a vinylpyridine, N-vinyl-2-pyrrolidone, allyl isocyanurate, vinyltetrahydrofuran, and/or an imidazole compound; and at least one comonomeric (meth)acrylate.

Abstract: A vegetable tannin is condensed with formaldehyde and an amine to provide an acid soluble product which is useful in a metal treatment solution to enhance corrosion resistance and paint adhesion characteristics of a metal surface.

Abstract: Compositions have melting points below 100.degree. C. which are useful in the formation of resins by reaction with polyphenolic compounds consisting of a mixture of more than two compounds having the formula ##STR1## wherein A represents a cyclic or acyclic aliphatic or substituted cyclic or acyclic aliphatic moiety having from 1 to 20 carbon atoms or an aromatic mono- or multi-nuclear or aliphatic substituted aryl residue having from 6 to 20 carbon atoms,R independently represents H, CH.sub.3, CH.sub.2 CH.sub.3 or C.sub.6 H.sub.5,R.sup.1 independently represents H or CH.sub.3,R.sup.2 independently represents H or CH.sub.3, andx represents an integer from 0 to 2are described.

Abstract: A polymerizable thermosetting composition which is a flowable liquid at moderate temperatures which comprises a mixture of:(A) from about 75% to about 95% by weight of a mixture of:(1) from about 80% to about 20% by weight of a bisoxazoline and(2) from about 20% to about 80% by weight of a polyphenolic compound and(B) from about 5% to about 25% by weight of at least one member selected from the group consisting of a monooxazoline and a monooxazine,a method for forming thermoset products therefrom and the novel thermoset products resulting from said method are described.

Abstract: Compositions having melting points below 100.degree. C. which are useful in the formation of resins by reaction with polyphenolic compounds consisting of a mixture of more than two compounds having the formula ##STR1## wherein A represents a cyclic or acyclic aliphatic or substituted cyclic or acyclic aliphatic moiety having from 1 to 20 carbon atoms or an aromatic mono- or multi-nuclear or aliphatic substituted aryl residue having from 6 to 20 carbon atoms,R independently represents H, CH.sub.3, CH.sub.2 CH.sub.3 or C.sub.6 H.sub.5,R.sup.1 independently represents H or CH.sub.3,R.sup.2 independently represents H or CH.sub.3, andx represents an integer from 0 to 2as described.

Abstract: Compositions comprising an oligomer which (a) on average comprises at least one in-chain residue of the general formula ##STR1## wherein Ar.sup.1 is an aromatic group, R.sup.1 is hydrogen or a hydrocarbyl group, X is a group which activates Ar.sup.1 to electrophilic attack, and Y.sup.1 is an organic residue bearing a carboxyl substituent; and (b) has one or more pendant and/or terminal acyloxymethyl groups are described. They may be used in dental, electronic and electrical applications.

Abstract: Novel metal-modified phenolic resins useful in the color developer part of a carbonless copy paper system are disclosed, as well as methods for preparing such resins. The metal-modified phenolic resins are reaction products of an aromatic carboxylic acid and a partial condensation reaction product (an oligomer) of a phenol and an aldehyde. The metal-containing compound is added either to the mixture of phenol and aldehyde in forming the oligomer or to the mixture of aromatic carboxylic acid and the oligomer. The color developer materials of the invention are coated on a paper substrate which forms a part of a pressure sensitive recording paper system. The color developer materials exhibit improved performance over prior art colored developer materials.

Abstract: A complex coordination compound of a novolac phenolic resin with zinc, copper, cobalt, cadmium, aluminum, indium, tin, chromium, cobalt or nickel is prepared by reaction of an oxide of the metal or an inorganic functional equivalent of the oxide, an alkanoic or aromatic monocarboxylic acid and an ammonia base. The resin product is useful as a color developer for coating of the record sheet of a chemical carbonless copying sheet system.

Abstract: The invention provides a polycondensation product of(a) sulfamic acid (H.sub.2 N--SO.sub.3 H) and/or at least one N-substituted organic derivative of the sulfamic acid as such or in the form of their salts,(b) formaldehyde and/or glyoxal(c) melamine and/or at least one phenolic compound.This polycondensation product may be used as at least one component in a material for construction.

Abstract: Condensation products which are obtained from formaldehyde, di-hydroxyaryl sulphones, phenols, if desired, and hydroxyarylcarboxylic acids and are prepared in a one-stage reaction at pH values between 2 and 5 are suitable as fixing agents for basic dyestuffs.

Abstract: Thermoplastic and thermoset polymeric compositions, having particular utility in the area of molding applications, are obtained by reacting a compound containing a plurality of oxazoline groups with a phenol or a phenolic resin each containing a plurality of aromatic hydroxyl groups.

Abstract: The phenolic chelate resin has a chelate-forming group wherein part or all of the hydrogen atoms in a primary and/or secondary alkylamino group introduced in a phenol nucleus are replaced by a methylenephosphonate group. Also disclosed is a process for producing such a chelate resin, and a method for recovering heavy metal ions with such a resin. The resin has particularly high selectivity for adsorbing uranium ions, as well as high heat, acid and alkali resistance as well as dimensional stability. The resin is very effective for recovering uranium from various uranium-containing solutions such as sea water, crude phosphoric acid fertilizer solutions, lowgrade uranium ore, waste water from uranium refining, and uranium mine water.

Abstract: An ultraviolet-absorbing amino compound; a paint containing the aforesaid ultraviolet-absorbing amino compound; and a coated article having on its surface a coated film containing the aforesaid ultraviolet-absorbing amino compound are provided. The ultraviolet-absorbing amino compound is produced by reacting (a) a compound having a light absorption maximum within a wavelength region of 300 to 400 m.mu. and containing a mono-, di- or tetra-hydroxyphenyl group, (b) at least one compound containing a amino group and (c) formaldehyde, in the presence of at least one alcohol. The ultraviolet-absorbing amino compound of this invention is used in resin products which undergo photodegradation by ultraviolet light, for example, paints or molded articles of resins, and is especially effective for use in thermosetting synthetic resin paints.

Abstract: A rubber composition comprising vulcanizable natural or synthetic rubber and a sulfide resin produced by (1) reacting a component (A) with a componet (B), followed by reacting with a component (D), or (2) reacting a component (A) with a component (B), followed by reacting with a component (C) and a component (D) simultaneously or sequentially, and if desired reacting the resulting phenol resin with an acylating agent, the component (A) being a phenol compound of the following formula, and/or an acylated compound thereof, ##STR1## wherein R.sub.1 and R.sub.2 are each a hydrogen atom, a hydroxyl, carboxyl, amino, C.sub.1 -C.sub.18 alkyl, C.sub.3 -C.sub.10 cycloalkyl, C.sub.3 -C.sub.10 cycloalkenyl or C.sub.7 -C.sub.12 aralkyl group or a phenyl group unsubstituted or substituted with at least one C.sub.1 -C.sub.

Abstract: Finely divided polyetherimide is provided which can be used in a variety of applications. These oligomers, in the form of fine powders, are particularly useful for coating wire by a powder coating technique.

Abstract: Disclosed is a color-developing composition for pressure-sensitive recording sheet material of the self-contained type comprising (A) 100 parts by weight of a copolymer obtained by reacting a p-alkylphenol having an alkyl moiety of from 1 to 12 carbon atoms and phenol with formaldehyde and (B) from 1 to 20 parts by weight of a hindered phenolic compound selected from phenols having an alkyl, alkylene or hydroxyl substituent radical in at least the 2- or 6-position, or both, of the benzene ring and derivatives thereof, the copolymer and the hindered phenolic compound being homogeneously dissolved in mutual solution. The hindered phenolic compound is either added to the starting materials for the preparation of the copolymer or, at the end of the copolymerization reaction, added to the resulting copolymer and dissolved homogeneously in mutual solution.

Abstract: Cyclic phenol-aldehyde resins, for example cyclic tetramers; derivatives thereof; processes by which they are prepared; and uses thereof.

Abstract: A phenolic chelate resin comprising the three-dimensional product obtained by cross-linking a phenolic compound represented by the general formula (I): ##STR1## (wherein M is an alkali metal atom, an ammonium group, or a hydrogen atom, and R.sub.1 and R.sub.2, which may be the same or different, each is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms) with a phenol and an aldehyde. The phenolic chelate resin selectively adsorbs ferric ion and/or cupric ion in an acidic aqueous solution at a pH of 3 and less.