Abstract: The invention relates to polymers containing units of the structure ##STR1## or mixtures of A with more than one of B, B-1 and B-2; wherein R and R.sup.1 are each independently C.sub.1 to C.sub.18 alkyl;R.sup.2 is oxygen, sulfur or --NR.sup.5 --;R.sup.5 is hydrogen or lower alkyl;R.sup.3 is alkylene having from 3 to 6 carbon atoms, optionally mono- or di- substituted with lower alkyl;W is hydrogen --NH.sub.4, an alkali metal or an alkaline earth metal;Y is alkylene;Z is hydrogen, --NH.sub.4, an alkali metal or an alkaline earth metal or mixtures thereof;X is lower alkyl, a hydroxy phenyl radical or mixtures thereof;t has a value of from 2 to 8 andm, m', m" and n independently have a value of from 30 to 3,500 and n represents at least 5 mole percent of the polymeric product. The invention is also related to the synthesis of the above polymers and to their use as superior adhesives which have significantly improved bond strength.

Abstract: Fluorinated styrenes of the formula I; ##STR1## where R.sub.1 is a C.sub.1 -C.sub.6 alkyl and R.sub.2 is the repeating unit ##STR2## where x is zero or any positive integer, which are useful as compatibilizing and toughening agents for various polymers such as styrene, dienes (butadiene, isoprene, etc.) acrylates, polymethacrylates, polycarbonates, polyesters, polyamides, etc. Particularly preferred are p-(1,1,1,3,3,3-hexafluoro-2-hydroxy isopropyl)-.alpha.-methylstyrene, polymers thereof, block and random copolymers thereof and polymer blends incorporating the same.

Abstract: A fiber-reinforced chlorinated polyethylene composition comprises 100 parts by weight of a continuous phase of a chlorinated polyethylene and 2-100 parts by weight of a polyamide dispersed in the continuous phase in a fine short fiber form. Further a process comprises kneading a chlorinated polyethylene and a fiber-formable polyamide at a temperature not lower than the melting point of the polyamide and then stretching the kneaded product to obtain the above fiber-reinforced chlorinated polyethylene composition. When in the above process, the kneading is effected by further adding a reactive binder, there can be obtained a fiber-reinforced chlorinated polyethylene composition wherein the compatibility and dispersion of the fiber-formable polyamide with and in the chlorinated polyethylene are improved.

Abstract: The invention relates to compatible polymer mixtures of a polyamide and a special vinyl monomer containing copolymerized structural units of the bisphenol derivative type. The new mixtures are suitable for the production of thermoplastic molding compounds.

Abstract: This invention relates to mixtures of short fibers of varying lengths, diameters and aspect ratios composed of an anisotropic polymer, to compositions containing said fibers and one or more thermoplastic or thermoset resins, and to a process for forming said mixtures.

Abstract: A refrigerant-transport hose having an inner tube, an outer tube located radially outwardly of the inner tube, and a reinforcing fiber layer interposed between the inner and outer tubes, the reinforcing fiber layer and the inner and outer tubes providing an integral tubular body, and inner tube including a gas-impermeable resinous layer formed of a composition containing a polyamide resin produced by reaction of hexamethylene diamine and an aliphatic dicarboxylic acid having eight to sixteen carbon atoms.

Abstract: Polymer compositions are provided which are capable of being formed into shaped articles and comprise a poly(2-methylpentamethylene terephthalamide), also known as nylon M5T, and a minor amount of an ionomer, e.g., a partially neutralized copolymer of an alpha-olefin and an alpha, beta-ethylenically unsaturated carboxylic acid. In particular, the compositions may be melt spun and drawn into filaments having good mechanical properties.

Abstract: Disclosed is an improved process of the post-emulsion method capable of forming crosslinked resin particles which do not have fusion bonds between particles and which have good storage stability and good redispersibility in an aqueous medium. The process comprises (a) dispersing in an aqueous medium a resinous component comprising (I) a base resin having a glass transition temperature (Tg) of 0.degree. C. or less and a polymerizable double bond, (II) a monomer which, when polymerized, provides a resin of which Tg is 20.degree. C. higher than that of said base resin, or a resin of which Tg is 20.degree. C. higher than that of the base resin, and (III) a polyvinyl compound; (b) crosslinking inside the dispersed resin particles and; (c) removing the aqueous medium therefrom.

Abstract: Polymer particles prepared by polymerizing polymerizable monomers by seed polymerization, with far more excellent polymerization stability than conventional seed polymerization processes, in the presence of a polymer emulsion comprising low molecular weight polymer particles, radically polymerizable in an aqueous system. The polymer particles are present in an amount of 0.5-30 parts by weight (on solid basis) per 100 parts by weight of polymerizable monomers, have a weight average molecular weight of 500-10,000 and are prepared by emulsion polymerization or soap-free polymerization. The seed polymerization is carried out by initially charging less than 30% by weight of said polymerizable monomers to the polymerization mixture, and after the polymerization conditions are established, by continuously or intermittently adding the remaining portion of said polymerizable monomers to the reaction system.

Abstract: Curable compositions based on (N-substituted carbamoyloxy)alkanoyloxyalkyl acrylate polymers. When cured the compositions are, for example, high-quality industrial finishes, sealants or encapsulants.

Abstract: In a method and apparatus for the production of thermoplastic, caprolactam containing molding compositions by hydrolytic polymerization of caprolactam in stirrer autoclaves in which a molten mass is polymerized at pressures of 5 to 20 bar and temperatures of 220.degree. to 280.degree. C., the molten mass is transferred into an intermediate vessel to which vacuum is applied for continued polymerization and removal of volatile portions. Subsequently, the mass is continuously fed into a multi-screw extruder, in order to attain at increased temperatures and vacuum the desired polymerization degree and the desired monomer and oligomer contents. In a subsequent zone of the extruder, when desired, additional agents are worked in, whereafter a further degasification occurs in the end zone of the extruder, whereafter the mass is extruded, quenched, subdivided and dried. The method and apparatus use relatively little energy as compared with the prior art.

Abstract: Hot melt adhesive composition of ethylene copolymer grafted with lactam oligomer, characterized by improved melt flow characteristics.

Abstract: The subject invention provides a composition having excellent extrusion characteristics comprising a difficulty-melt-processible polymer and 0.002-0.5 wt. % of one or more fluoropolymer process aids wherein the fluoropolymer has a fluorine to carbon ratio of at least 1:2, is capable of forming a die-coating film under the prevailing conditions of extrusion temperature and pressure, and contains an effective amount of polar functional polymer chain end groups, --W, wherein --W is selected from --COF, --SO.sub.2 F, --SO.sub.3 M, --OSO.sub.3 M, --COOR, and --COOM, wherein R is C.sub.1-3 alkyl and M is hydrogen, a metal cation, preferably an alkali or alkaline earth metal cation, or a quaternary ammonium cation.

Abstract: This invention is directed to polymers (including oligomers) that contain (N-substituted carbamoyloxy)alkanoyloxyalkyl acrylates, to a process for their preparation by reacting the carbamoyloxy alkanoyloxyalkyl acrylates with themselves, with lactone acrylates, and/or with other ethylenically unsaturated monomers, and to coating, ink, adhesive, and sealant compositions (including the cured coatings, inks, adhesives, and sealants) that are obtained by curing the above compositions by various means. The cured compositions, which are, for example, high-quality industrial finishes, sealants or encapsulants, are preferably made by incorporation of various conventional crosslinking agents and other normally-used formulating ingredients with the polymeric compositons of the invention.

Abstract: Improved polyamide-based compositions are provided which are particularly formulated for plasma-spray application to surfaces subjected to acidic conditions. The compositions include respective amounts of polyvinylidene fluoride, a polyamide (e.g., Nylon 11) and a compatable adhesive such as a nylon terpolymer adhesive.

Abstract: A process of blow molding, and compositions useful in the process. The articles are blow molded from compositions formed from thermoplastic polymeric material, a fluorinated olefinic polymer or copolymer and, optionally, an elastomeric impact modifier.

Abstract: A method of preparing a fiber reinforced elastomer by forming fibers therein in-situ and an elastomer made thereby are provided. In the method, a fiber forming material, preferably a high performance polymer, is dissolved in a compatible solvent to form a solvent/polymer mixture, and the mixture is added to the elastomer during compounding or mixing. The polymer is quickly dispersed into the elastomer, and the solvent rapidly evaporates. The shear of the mixer causes elongation of the polymer into fibers. The fibers may also be oriented by the shear of the mixer.

Abstract: This invention relates to soft, rubber-like, thermoplastically processible polymer alloys based on 10 to 50% by weight of (cyclo)aliphatic, thermoplastic polyamides and 90 to 50% by weight of special cross-linked, particulate alkyl acrylate copolymer rubbers suitable for the preparation of rubber-like, elastic moulding compounds.The invention also relates to a process for their preparation.

Abstract: A thermosetting resin composition formed of a polyaminobismaleimide resin, which is composed of a bismaleimide compound and a diamine compound, and a solid lubricant. The composition has low coefficient of friction and excellent wear resistance, and can be utilized for self-lubricating parts.

Abstract: A process for the continuous and discontinuous production of polycaprolactam is disclosed which includes the step of polymerizing, by anionic polymerization, .epsilon.-caprolactam to which suitable initiators and activators are added. The process may optionally include the addition of comonomers, pigments, electroconductive fillers, modifying polymers, inorganic fillers, reinforcing fibers, inorganic fillers and/or other additives to a dispersing media in which the polymerization takes place with polycaprolctam, copolymers or composites thereof being obtained in the form of particles. The foregoing additives may, for example, be added to the dispersing media dropwise with mechanical or convective stirring under controlled temperature conditions.

Abstract: Radiation-crosslinkable contact adhesive mixtures are prepared from polymers having a glass transition temperature of less than 0.degree. C. and a K value of from 20 to 80, derivatives of dihydroxypropyl (meth)acrylates as reactive diluents and small amounts of polymerizable tertiary amino compounds by a process in which the mixture is heated at from 80.degree. to 120.degree. C. for not more than 2 hours and solvents are then separated off under atmospheric or reduced pressure.

Abstract: A mixed polymer material is formed of a polyelectrolyte ternary copolymer having a hydrophobic backbone and containing 10 to 90 percent unsubstituted portions and the remainder being substituted with hydrophilic groups such as a styrene ternary copolymer of the formula: ##STR1## where R.sup.1 is alkyl, preferably ethyl, and R.sup.5 is hydroxyalkyl, preferably hydroxethyl. The ternary copolymer self-segregates into discrete hydrophilic and hydrophobic domains and is believed to act as a template to segregate the polyelectrolyte into the domains. The mixed polymer has large ion-exchange capacity, very high effective diffusion constants of incorporated counter-ions and prolonged retention of multiply-charged counter-ions. The mixed polymer forms a stable and effective coating for electrodes for electrocatalytic applications.

Abstract: Impact-resistant nylon molding materials containA a linear, thermoplastic nylon composed of radicals derived from terephthalic acid and isophthalic acid and alkanediamines of 4 to 10 carbon atoms, andB from 5 to 60% by weight, based on A, of one or more copolymers of1. from 50 to 80% by weight of ethylene,from 20 to 50% by weight of a primary or secondary C.sub.2 -C.sub.8 -alkyl ester of (meth)acrylic acid andfrom 0.5 to 10% by weight of a monomer possessing an acidic functional group or a latent acidic functional group, or2. from 70 to 98% by weight of a primary or secondary C.sub.2 -C.sub.8 -alkyl ester of (meth)acrylic acid,from 1 to 30% by weight of a monomer possessing an acidic functional group or a latent acidic functional group, andfrom 1 to 5% by weight of a monomer containing 2 or more olefinic double bonds in the molecule,the percentages stated in 1. and 2. summing to 100% in each case, andC. if required, effective amounts of additives.

Abstract: It is desirable to increase the modulus of rubbers utilized in a wide variety of applications. This invention discloses a technique for modifying rubbers to improve their modulus without sacrificing other properties. The subject invention more specifically relates to a process for preparing a rubber composition having a high modulus which comprises reacting maleic anhydride with at least one polydiene rubber and at least one nylon.

Abstract: Dispersions of core-shell polymers in caprolactam wherein the core-shell polymer comprises a crosslinked elastomer core and a hard thermoplastic shell prepared by adding an aqueous dispersion of core-shell polymer to an aqueous solution of caprolactam, stirring the mixture to provide a uniform dispersion and evaporating water from the mixture. Such dispersions can be combined with caprolactam polymerization initiator and caprolactam polymerization catalyst to provide rubber-modified nylon-6 polymers.

Abstract: Disclosed herein are a resin composition comprising 5 to 95% by weight of a vinylidene chloride resin and 5 to 95% by weight of a polyamide resin having a low crystalline melting point of not higher than 210.degree. C. and a molded product of said resin composition.The molded product of the present invention shows a molded product excellent in gas-barrier property and impact strength at low temperature, particularly a film, sheet or container.Among the resin compositions of the present invention, since the composition having 60 to 95% by weight of vinylidene chloride resin is particularly rich in gas-barrier property, it is suitable for packaging foods, and since the composition having more than 40% by weight and not more than 95% by weight of polyamide resin is excellent particularly in impact strength at low temperature, it is suitable as the packaging material for use at an extremely low temperature.

Abstract: A thermoplastic elastomer composition which comprises 25-95% by weight of a polyamide and 75-5% by weight of a halogenated butyl rubber, a chlorosulfonated polyethylene or both thereof. Said composition is excellent in resistance to Freon gas permeation and has good oil resistance and low-temperature resistance. A hose wherein the layer to be contacted with a gas is made of the above thermoplastic elastomer composition is suitable as a Freon gas R-22 hose.

Abstract: The invention relates to polymers containing a lactam functionality and having in its molecule repeating units of the general formula: ##STR1## wherein R.sup.1 is C.sub.1 to C.sub.18 alkyl;R.sup.2 is oxygen, sulfur or amino;R.sup.3 is alkylene having 3 to 6 carbon atoms optionally substituted with lower alkyl;Z is hydrogen, an alkali metal, an alkaline earth metal or ammonia;n has a value of from 30 to 3,500 andt has a value of from 2 to 8;and to the use and synthesis of said polymer.

Abstract: Dispersion-process-produced, non-melt-processible, particulate, core-shell, tetrafluoroethylene copolymer comprising recurring units of tetrafluoroethylene and modifying recurring units of at least one ethylenically unsaturated comonomer that is copolymerizable with the tetrafluoroethylene, the number of recurring units of comonomer in the shell being sufficient to enable the copolymer to compound uniformly with an elastomer or plastic without forming visible agglomerates, and blends thereof with elastomeric and plastic resins.

Abstract: It is desirable to increase the modulus of rubbers utilized in a wide variety of applications. This invention discloses a technique for modifying rubbers to improve their modulus without sacrificing other properties. The subject invention more specifically relates to a process for preparing a rubber composition having a high modulus which comprises reacting at least one thio acid with at least one polydiene rubber and at least one nylon.

Abstract: Resin compositions of (A) 50-95 percent by weight of a polyamide and (B) 5-50 percent by weight of a modified polyolefin containing in side chains 0.005-5 molar percent of functional groups expressed by formulas (I) and/or (II) below and 0.005-5 molar percent of functional groups expressed by formulas (III) and/or (IV) below provide molds having a high impact resistance and are applicable to automobile parts. ##STR1## Where R.sub.1 represents hydrogen or methl and wherein R.sub.2, R.sub.3 and R.sub.4 represent hydrogen, aliphatic, alicyclic or aromatic residual groups having 1-30 carbon atoms.

Abstract: Thermoplastic molding materials contain, as essential components,(A) from 2 to 97.9% by weight of a nylon,(B) from 2 to 97.9% by weight of a polyaryl ether ketone and(C) from 0.1 to 30% by weight of a polymeric component containing hydroxyl groupsand in addition(D) from 0 to 50% by weight of an impact-modifying rubber and(E) from 0 to 60% by weight of fibrous and/or particulate fillers.

Abstract: Thermoplastic polyamide mixtures of polyamides based on dimerized fatty acids in which at least one polyamide contains as an incorporated unit (a) a C.sub.2 -C.sub.10 aliphatic diamine capable of diamide formation, which is N-substituted with C.sub.10 -C.sub.25 -alkyl, and (b) a C.sub.2 -C.sub.40 -diamine capable of diamide formation comprising a diprimary amine, a heterocyclic amine, or a diomine containing one or two secondary amino groups and which is N-C.sub.1 -C.sub.8 -alkyl-substituted on at least one side.

Abstract: Novel moisture resistant polyamide compositions are prepared comprising at least one polyamide and at least one di- or poly- hydric compound, oligomer or polymer free of sterically hindered hydroxy groups.

Abstract: A flexible thermoplastic resin composition is disclosed comprising (A) from 5 to 59 parts by weight of a polyamide resin and (B) from 95 to 41 parts by weight of an ethylene copolymer containing (a) from 50 to 90% by weight of ethylene, (b) from 5 to 49% by weight of an .alpha.,.beta.-unsaturated carboxylic acid alkyl ester, and (c) from 0.5 to 10% by weight of maleic anhydride. The resin composition of the invention has excellent cold resistance, particularly impact strength at low temperatures, and an excellent balance between rubbery elasticity and rigidity in addition to excellent thermal resistance, abrasion resistance, and chemical resistance.

Abstract: This invention is directed to polymers (including oligomers) that contain (N-substituted carbamoyloxy)alkanoyloxyalkyl acrylates, to a process for their preparation by reacting the carbamoyloxy alkanoyloxyalkyl acrylates with other ethylenically unsaturated monomers, and to coating, ink, adhesive, and sealant compositions (including the cured coatings, inks, adhesives, and sealants) that are obtained by crosslinking the above compositions by various means. The cured compositions, which are, for example, high-quality industrial finishes, sealants or encapsulants, are made by incorporation of various conventional crosslinking agents and other normally-used formulating ingredients with the polymeric compositions of the invention.

Abstract: A process for preparing a predispersed fiber composition useful for dispersing discontinuous fibers into a rubber or plastic polymer compound is disclosed which comprises mixing at least about 15 percent by weight of a pourable binder composition with up to about 85 percent by weight of discontinuous fibers at a temperature of from about 40.degree. C. to about 150.degree. C. until a homogeneous predispersed fiber composition is obtained. The binder composition comprises from about 50 to 100 percent by weight of a rubber or plastic polymer, from 0 to about 50 perecnt by weight of a plasticizer or peptizer for the polymer, and from 0 to about 45 percent by weight of critical chemical additives, and is pourable at ambient tmeperature or becomes pourable upon being heated to a temperature of up to about 135.degree. C. and has a Brookfield viscosity of less than about 1,300,000 centipoises at the temperature at which it is pourable.

Abstract: A shaped article comprised of a tetrafluoroethylene polymer with a number average molecular weight of at least about 10.sup.6 which exhibits specific heat shrinking properties represented by an average maximum expansion ratio of from 2 to 10, a least maximum shrinkage ratio of 0.71 or less, an orientation release stress at 200.degree. C. of less than 5 Kg/cm.sup.2 and a shrinking starting temperature of at least 80.degree. C. The shaped article has excellent compression creep resistance, compression resistance, impact strength, dimensional stability, gas barrier property and tensile strength. Accordingly, it can be advantageously utilized as a sealant, a lining material, a bearing pad, a sliding pad, etc.

Abstract: A process for preparing a polymeric blend stock comprising fluidizing a first particulated polymer, contacting the particulated polymer with droplets of a latex of a second polymer or polymer mixture, retaining the resulting product in a fluid state under conditions sufficient to dry the latex, and recovering the resulting dried polymeric blend stock.

Abstract: A method of adsorbing a substance such as an optically active substance, comprising contacting a solution of the substance in a solvent with an adsorbent consisting of a cross-linked polymer comprisingan optically active, synthetic poly(amino acid) represented by the general formula (I): ##STR1## wherein R stands for an organic group, R' stands for hydrogen or an alkyl group and n is an integer of at least 5, which may be protected at a terminal amino group anda carrier polymer supporting said synthetic poly(amino acid) thereon, said carrier polymer having affinity for said solvent. A method for producing the cross-linked polymer is also described.The adsorbent is especially useful for optical resolution of racemic mixtures.

Abstract: A process for the preparation of moulded bodies of thermoplastic polyamides, which comprises intensively mixing a polyamide and a masterbatch, converting the mixture by conventional thermoplast processing to moulded bodies and, before use, conditioning the bodies by contact with ambient moisture or, briefly, with water, in which the masterbatch contains at least 5% by weight of a silane substituted by one, 2 or 3 hydrolysable radicals and a functional group which can undergo a chemical reaction, to form a bond, with amino groups and/or carboxyl groups and/or amide groups in the polyamide chain.

Abstract: Surface treating water-absorbent resins with a polyquaternary amine substantially increases both the rate of water absorption and the quantity of water absorbed and retained by the resin. In addition to improved water absorbing properties, the surface-treated resins maintain the necessary "dry feel" required for most applications.

Abstract: A thermoplastic polybend of nylon 66 and polymethylmethacrylate having superior friction and wear properties. Alternatively, the polybend composition may contain a third component of polytetrafluoroethylene to further improve its friction and wear properties.

Abstract: A soil release composition comprising:(A) a polymer comprising 10 to 100% by weight of constituting units of the formula: ##STR1## wherein R.sub.f is a C.sub.3 --C.sub.21 fluoroalkyl group; R.sup.1 is a hydrogen atom or a C.sub.2 --C.sub.4 acyl group; R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are, the same or different, each a hydrogen atom, a methyl group or an ethyl group; A is a group of the formula: --CH.sub.2 CH(OR.sup.1)CH.sub.2 --OCO-- which R.sup.1 is the same as defined in the above, --CO--, --(CH.sub.2).sub.k N(R.sup.2)CO-- in which R.sup.2 is the same as defined in the above and k is an integer of 1 to 10, or --(CH.sub.2).sub.

Abstract: A method of adsorbing a substance such as an optically active substance, comprising contacting a solution of the substance in a solvent with an adsorbent consisting of a cross-linked polymer comprising an optically active, synthetic poly(amino acid) represent by the general formula (I): ##STR1## wherein R stands for an organic group, R' stands for hydrogen or an alkyl group and n is an integer of at least 5, which may be protected at a terminal amino group and a carrier polymer supporting said synthetic poly(amino acid) thereon, said carrier polymer having affinity for said solvent. A method for producing the cross-linked polymer is also described.The adsorbent is especially useful for optical resolution of racemic mixtures.

Abstract: A modified polyolefin composition comprising(A) 50 to 99 parts by weight of a modified polyolefin having an intrinsic viscosity [.eta.] of 0.5 to 10 dl/g and a degree of crystallization of at least 20% selected from the group consisting of polyolefins modified with styrene-type hydrocarbons, polyolefins modified with unsaturated epoxy compounds, polyolefins modified with unsaturated silane compounds, halogenated polyolefins and hydroxyl group-containing polyolefins, and(B) 1 to 50 parts by weight of a thermoplastic polymer selected from the group consisting of(B-1) thermoplastic polymers having a flexural modulus of less than 1000 kg/cm.sup.2, a glass transition temperature (Tg) of not higher than 0.degree. C. and a weight average molecular weight (Mw) of at least 400,000, and(B-2) polar non-olefinic thermoplastic polymers or ethylenic polymers having a flexural modulus of at least 1000 kg/cm.sup.2 and an adhesion strength, with respect to the modified polyolefin (A), of not more than 200 g/cm.

Abstract: In one embodiment this invention provides a nonlinear optical substrate which comprises a transparent film of an external field-induced noncentrosymmetric macroscopic orientation of poly[[benzo(1,2-d:5,4-d')bisthiazole-2,6-diyl]-1,4-phenylene] molecules: ##STR1##

Abstract: Unsaturated polyamide polymers are provided which are comprised of a polyamide chain terminated at one end by a group containing at least one double bond. The polymers are particularly useful in the preparation of molded object coatings, water tight joints, grafting onto thermoplastic polymers or copolymers, and the like.

Abstract: A composition comprising an intimate thermoplastic admixture of at least two structurally dissimilar organic polymers, a delamination inhibiting effective amount of the first organic polymer covalent bond graft linked to the second organic polymer through a multifunctional graft linking agent of the insertion, electron deficient type the new admixtures are useful for the usual applications associated with the admixture properties.

Abstract: A reactive hardenable polymer mixture which comprises(A) at least one epoxy compound and(B) at least one polycarboxylic acid compound in the form of a component selected from the group consisting of(a) at least one compound of formula ##STR1## wherein R.sup.1 is a radical derived from at least one polymeric product containing hydroxy groups selected from the group consisting of a polymerization and a condensation product and a combination thereof in the form of polyesters, polymers each having a hydroxy number between 20 and 300, phenol resins having a hydroxy number between 100 and 800 and combinations thereof,R.sup.2 is a radical of an at least tetrabasic cyclic carboxylic acid having at least one COOH-group in an o- or peri-position to the ester bond,R.sup.5 is a radical of an at least dibasic cyclic carboxylic acid having at least one COOH-group in o- or peri-position to the ester bond and R.sup.5 may also be as defined for R.sup.