Abstract: A multiple-pack system composed of a combined pack made from individual packages, where the individual packaging takes place in a biaxially stretch-oriented polypropylene film with modified polyolefinic sealable layers. The characterizing features of the multiple-pack system are that the combined-pack film is composed of a sealable, biaxially stretch-oriented coextruded polyester film having more than one layer, where the sealable outer layer(s) comprise(s) copolyester. In the novel multiple-packed system, the combined-pack film is sealable with itself, but does not seal to the biaxially oriented polypropylene films of the individual packages.

Abstract: A copolyester blend resistant to ultraviolet radiation consists essentially of a polyethylene terephthalate based copolyester having 1,4-cyclohexanedimethanol residues; an effective amount of an ultraviolet radiation absorber selected from the group consisting of benzoxazinones, dimeric benzotriazoles, triazines and mixtures thereof; and from about 2 to about 25 mole percent of 4,4′-biphenyldicarboxylic acid residues present in the copolyester wherein the mole percent is based on 100 mole percent of dicarboxylic acid or equivalents. The copolyester blend is useful in making UV radiation resistant thermoformed articles.

Abstract: A multilayered polymer film includes a first set of optical layers and a second set of optical layers. The first set of optical layers is made from a polyester which is often birefringent. The polyesters of the first set of optical layers typically have a composition in which 70-100 mol % of the carboxylate subunits are first carboxylate subunits and 0-30 mol % are comonomer carboxylate subunits and 70 to 100 mol % of the glycol subunits are first glycol subunits and 0 to 30 mol % of the glycol subunits are comonomer glycol subunits, where at least 0.5 mol % of the combined carboxylate and glycol subunits are comonomer carboxylate or comonomer glycol subunits. The second set of optical layers comprise copolyesters wherein 0.01 to 2.5 mol % of the combined carboxylate and glycol subunits are carboxylate subunits derived from compounds having three or more carboxylate or ester functionalities, glycol subunits derived from compounds having three or more hydroxyl functionalities, or combinations thereof.

Abstract: Transparent, articles, in particular sheets, having a thickness greater than 5 mm obtained from polyalkylene terephthalate/isophthalate resin containing 5-20% of isophthalic, acid units,. characterised by an intrinsic viscosity greater than 0.8 dl/g; a melt strength at 280° C. greater than 1 cN and a melt viscosity at 280° C. greater than 2000 Pa·s for shear rates tending to zero and not less than 200 Pa·s for shear rates of 1000 sec−1.

Abstract: A laminate sheet comprising (A) a polyester block copolymer which comprises 20 to 70 wt % of a hard segment consisting of an aromatic polyester and 80 to 30 wt % of a soft segment consisting of an aromatic polyester and (B) cloth on at least one side of which the polyester block copolymer is laminated, the melting point (T,.degree. C.) of the polyester block copolymer satisfying the following expressions: T0-5 >T>T0-60 and T>T'+10 (in which T is defined above, T0 is a melting point (0.degree. C.) of the aromatic polyester constituting the hard segment, and T' is a melting point (.degree. C.) of a random polymer obtained by adding 0.1 wt % of titanium tetrabutoxide to the polyester block copolymer and melting and kneading at 250.degree. C. for 3 hours).

Abstract: A poly(hydroxy ester ether) is prepared by reacting a) a diacid containing a hetero moiety of the formula:HO.sub.2 CCH.sub.2 X(RX).sub.y CH.sub.2 CO.sub.2 Hwherein X is selected from the group consisting of --O--, --S--, and NH; y is the whole number 0 or 1; and R is selected from the group consisting of an aromatic moiety and a heterocyclic moiety having from 6 to 30 carbon atoms; andb) a diglycidyl ether generally represented by the formula: ##STR1## wherein R.sup.2 is an aromatic moiety or divalent aliphatic hydrocarbon having 2 to 20 carbon atoms. Films, articles and laminations made from the composition exhibit an oxygen permeability of less than about 8 cc-mil/100 in.sup.2 -24 hour-atmosphere. The present invention is further directed to a miscible blend having the poly(hydroxy ester ether) of the present invention and a second component selected from a saturated polyester of an aromatic diacid, such as PET and PEN.

Abstract: An ink jet ink composition comprising from about 0.5% to about 30% by weight of a pigment, a carrier and a sulfonated polyester dispersant in a ratio of dispersant:pigment from about 0.1:1 to about 5:1.

Abstract: A method is disclosed of producing a copolymer of polyethylene terephthalate and polyethylene naphthalate. The method comprises esterifying a combination of a diester of naphthalene, terephthalic acid, and ethylene glycol to produce an esterification reaction mixture that includes the alcohol byproduct of the naphthalene diester, distilling the reaction mixture to remove at least a portion of the esterification byproducts from the reaction mixture in the form of a vapor stream of which the majority component is water vapor and which includes the alcohol byproduct of the naphthalate ester in the vapor state, and combusting at least a portion of the vapor stream under conditions sufficient to decompose at least a portion of the alcohol byproduct present in the vapor stream.

Abstract: The disclosure relates to a copolymer obtainable by radically initiated polymerization of the following: A) 70-99.9 wt. % an olefinically unsaturated C.sub.3 -C.sub.5 monocarboxylic acid, an olefinically unsaturated C.sub.4 -C.sub.8 dicarboxylic acid or its anhydride, or a mixture of such carboxylic acids; with B) 0.1-30 wt. % one or more multiply olefinically unsaturated carboxylic acid derivatives of formula (I)Z--Y--(CHR.sup.3 --CH.sub.2 --X).sub.n --R.sup.4 (I)in which Z is a vinyl or allyl group or structure (a), ##STR1## R.sup.1, R.sup.2 are hydrogen or methyl, R.sup.3 is hydrogen, methyl or ethyl, R.sup.4 is a singly or multiply olefinically unsaturated alkenyl or cycloalkenyl group or a singly or doubly olefinically unsaturated arylalkylene group, X is oxygen or NH, Y is oxygen, NH or N-alkyl, n is a number between 0 and 50; and C) 0-29.9 wt. % other copolymerizable monomers. The proposed copolymer can be used as a thickener or dispergent for aqueous systems.

Abstract: Biaxially oriented films containing at least one layer of polyethylene naphthalate bibenzoate (PENBB) copolyester wherein the copolyester contains from about 60 to about 40 mol % of a first recurring unit of the formula (II). ##STR1## and about 40 to about 60 mol % of a second recurring unit of formula (I). The copolyester preferably contains less than 10 mol % of recurring units derived from terephthalate or other dicarboxylic acids. The films have a total thickness of 0.05-500 .mu.m and may contain inert particles.

Abstract: There are disclosed a flame retardant polyethylene terephthalate resin composition comprising (A) a polyethylene terephthalate resin containing ethylene terephthalate units as a main constituent, prepared by the use of a germanium compound as a catalyst, (B) a halogen flame retardant, (C) at least one compound selected from the group consisting of epoxy compounds and carbodiimide compounds and (D) an antimony compound, and moreover, resin compositions further containing, besides those (A), (B), (C) and (D), at least one selected from the group consisting of (E) a reinforcing filler, (F) at least one inorganic compound composed of silicates and silicic acid and (G) a crystallization accelerator. The resin compositions are excellent in physical properties and wet heat resistance. By the addition of the specific inorganic compounds and the crystallization accelerators, releasability is also improved and thus high cyclization of molding is possible.

Abstract: A rubber-polyester composite comprising a rubber and a core-and-sheath heterocomponent fiber wherein the fiber core is formed from a linear polyester derived from an alkyl glycol and an aromatic diacid, and wherein the fiber sheath is formed from a compatibilizing acid-terminated or isocyanate-terminated polyester. The fiber sheath may also be composed of a blend of a thermoplastic elastomer and the compatibilizing polyester.

Abstract: A biaxially oriented polyester film which has excellent resistances to dry heat deterioration and wet heat deterioration, which can withstand the use in an atmosphere of relatively high moisture content, and which is useful, for example, as an electrical insulating film, a film for transparent electrode, a film for absorption of electromagnetic wave (e.g. a film used as an inspection window of microwave oven) and a reflection film. This polyester contains ?ethylene-2,6-naphthalenedicarboxylate as the main recurring unit.! 99.5 to 95 mole % of ethylene-2,6-naphthalenedicarboxylate and 0.5 to 5 mole % of ethylene-2,7-naphthalenedicarboxylate and has a density of 1.355 to 1.370 g/cm.sup.3 and an intrinsic viscosity of 0.62 to 0.90. The polyester film has an amount of terminal carboxyl in the polyester of 40 eg/10.sup.6 g or less and an amount of oligomers of 2.0 mg/m.sup.2 film or less.

Abstract: The present invention relates to blends of a polyester, polyamide or polyester/amide containing a copolymerizable fluorescence quenching compound and a second polymer. The blends of the present invention display reduced fluorescence. Specifically the blends comprise(a) a polyester/amide comprising:(1) a dicarboxylic acid component which comprises at least 0.1 mol % of a dicarboxylic acid selected from the group consisting of terephthalic acid and/or terephthalate ester;(2) a diol and/or diamine component;(3) 0.1 to 99.9 mol %, based on 100 mol % dicarboxylic acid and 100 mol % diol, of a copolymerizable fluorescence quenching compound;(b) a second polymer selected from the group poly(alkylene terephthalate) homo and copolyesters, poly(alkylene naphthalate) homo and copolyesters, poly(cycloalkylene terephthalate) homo and copolyesters, poly(alkylene 1,4-cyclohexanedicarboxylate) homo and copolyesters, and polycarbonate homo and copolymers.

Abstract: New copolymers of recycled polyesters having improved properties are disclosed. The copolyesters are produced by a reaction of recycled polyalkylene terephthalate and a dicarboxylate moiety.

Abstract: In the present invention, a class of catalysts is described, to be used in the polycondensation stage in the synthesis of poly(ethylene terephthalate), constituted by a composition of metal derivatives in quantity so that the content of these in the final polymer is below 130 ppm.

Abstract: This invention is an improved process for producing polyester copolymers, which employs a combination of an acid-based process and an ester-based process. The ester-based process is used to manufacture a low molecular weight naphthalate-based polymer, and the acid-based process is used to manufacture phthalate-based oligomers. The low molecular weight naphthalate-based polymer is combined with the phthalate-based oligomers, or the raw materials used to form the phthalate-based oligomers, to form a random polyester copolymer. Specifically, the process of the invention may be employed to manufacture, in an ester-based process, a low molecular weight polyethylene naphthalate polymer, which is then combined with polyethylene terephthalate oligomers produced in an acid-based process, and the acid-based process is then used to continue the polymerization reaction. Ester interchange reactions and further polymerization result in the production of a random polyethylene terephthalate/naphthalate copolymer.

Abstract: Hot-melt adhesives are based on a random copolyetherester formed from aromatic dicarboxylic acids, terephthalic acid and isophthalic acid wherein the molar proportion of terephthalic acid is at least 55% based on the acid content, with a butanediol content between 20 and 85 mol % and containing at least 10 mol % triethylene glycol; the remainder of the diol content is preferably diethylene glycol. Copolyetheresters of this type are distinguished by excellent adhesion properties, a low melting point, rapid crystallization, and good resistance to laundering and dry cleaning at a minimum viscosity of 80 Pas.

Abstract: A base film for a photographic film, which (A) consists essentially of polyethylene-2,6-naphthalenedicarboxylate containing naphthoic acid unit in an amount, in terms of methyl naphthoate, of 2 to 1,000 ppm, (B) has a light transmittance, T.sub.400, of at least 95%/cm at a wavelength of 400 nm when a solution of 10 mg/ml of the polyethylene-2,6-naphthalenedicarboxylate in a hexafluoroisopropanol/chloroform mixed solvent having a hexafluoroisopropanol/chloroform weight ratio of 2/3 is measured, (C) has a yellow index Y.sub.ID of at most S, and (D) has a haze value of 2.0% or less.

Abstract: An aqueous dispersion comprising (A) a polyester comprising an aromatic dicarboxylic acid, an addition product of bisphenol A with ethylene oxide and/or propylene oxide, and a dicarboxylic acid having a metal base of sulfonic acid and/or a polyol having a metal base of sulfonic acid, (B) a water-soluble organic compound having a boiling temperature of about 60.degree. C. to about 250.degree. C., (C) water and (D) a neutralizer; the amounts of the components A, B, C and D satisfying the following ratios of (1) to (3):(1) A/B/C being about 1% to about 70% by weight/about 0% to about 69% by weight/about 9% to about 99% by weight,(2) B/(B+C) being about 0 to about 0.7 (weight ratio), and(3) the equivalent ratio of D to A being about 0.1 to about 20.

Abstract: Provided are thermosetting powder coatings based on a resin based on dimethyl 2,6-decalindicarboxylate and neopentyl glycol. The resin may be modified with other diacids or diols but must have a suitable glass transition temperature (Tg) required for powder coatings. We have found that this aliphatic polyester meets the basic Tg requirement of powder coatings and found that it provides powder coating with excellent weatherability. The polyester resin has a number average molecular weight (Mn) of from about 1,500 to about 10,000, a glass transition temperature (Tg) of about 45.degree. C. to 100.degree. C., and a hydroxyl or acid number of from about 20 to about 100.

Abstract: A film for heat-sensitive stencil paper comprising a biaxially oriented film having a thickness of 0.5 to 6.0 .mu.m and formed from a polyester composition comprising polybutylene terephthalate and at least one other polyester, the content of the polybutylene terephthalate in the polyester composition being 20 to 80 wt %, the polyester composition has one melting point or a plurality of melting points with a difference of less than 10.degree. C. between the highest melting point and the lowest melting point.

Abstract: The present invention provides a powder coating composition which is suitable for precoated steel plates. The powder coating composition has excellent storage stability (e.g. blocking resistance) and provides a cured film having good weather resistance and a good balance of hardness and processability. The powder coating composition comprises;(I) 95 to 70% by weight of a polyester resin having a glass transition temperature of 40.degree. to 70.degree. C., prepared from (i) and acid component containing at least 80 mole % of an aromatic dicarboxylic acid with (ii) a polyol component which comprises(a) at least 50 mole % of neopentyl glycol, and(b) 1 to 10% by weight of a diol selected from the group consisting of a linear chain C.sub.8 -C.sub.16 alkylene diol, 2-methyl-1,8-octane diol and a mixture thereof, and(II) 5 to 30% by weight of a curing agent.

Abstract: This invention relates to naphthalenedicarboxylic acid containing polymer compositions having reduced fluorescence. More specifically, the polymers contain at least 0.1 mole percent of a dicarboxylic acid selected from 2,6-naphthalenedicarboxylic acid or 2,6-naphthalenedicarboxylate ester, with 0.1 to 5 mole percent of a copolymerizable halogen containing aromatic compound. These polymers are useful for packaging applications where clarity and/or aesthetic appeal are of concern.

Abstract: This invention relates to naphthalenedicarboxylic acid containing polymer compositions having reduced fluorescence. More specifically, the process involves melt blending a naphthalenedicarboxylic acid containing polymer with 0.1 to 5 weight percent of a fluorescence quenching compound selected from a halogen containing aromatic compound, an aromatic ketone or a naphthol compound and thermoforming the blend into an article. The blends are useful for packaging applications where clarity and/or aesthetic appeal are of concern.

Abstract: This invention relates to a poly(ethylene 2,6-naphthalene dicarboxylate) composition having reduced fluorescence. More specifically, the composition contains poly(ethylene 2,6-naphthalene dicarboxylate) with 0.1 to 5 mole percent of a copolymerizable halogen containing aromatic compound. The polyesters are useful for packaging applications where clarity and/or aesthetic appeal are of concern.

Abstract: This invention relates to poly(ethylene 2,6-naphthalene dicarboxylate) blends having reduced fluorescence. More specifically, the process involves melt blending poly(ethylene 2,6-naphthalene dicarboxylate) with 0.1 to 5 weight percent of a fluorescence quenching compound selected from a halogen containing aromatic compound, an aromatic ketone or a naphthol compound and thermoforming the blend into an article. The blends are useful for packaging applications where clarity and/or aesthetic appeal are of concern.

Abstract: Functional-amine polyesters have at least a first residue of a first monomer, a second residue of a second monomer and from about 0.1 to about 3.0 mole percent of a functional-amine residue of a functional amine prepared by reacting the first and second monomers and the functional amine in an inert atmosphere. The functional amine has a functional group which facilitates polymerizing the amine and the first and second monomers. The amine residue facilitates reaction of the functional-amine polyester in an organic peroxide cross-linking reaction system.

Abstract: This invention relates to an aqueous dispersion of a water-dissipatable polyester and a styrenated acrylic copolymer in combination with either an acrylic polymer or a hydantoin-formaldehyde resin.

Abstract: Provided are water-dissipatable, sulfo-containing polyesters and polyester-amides having copolymerized therein thermally stable near infrared flourophoric compounds. The polymers are useful in coating or ink compositions, which are in turn useful for marking articles for identification/authentication purposes. Also provided is a method for invisibly marking such articles and a method for detecting and sorting articles by utilizing the near infrared flourophoric ink or coating compositions.

Abstract: A hollow article or sheet of a copolyester which comprises, as main components, terephthalic acid as a dicarboxylic acid component and ethylene glycol as a diol component and which is characterized by:(1) isophthalic acid as a dicarboxylic acid component being from 0.5 to 3.0 mol %,(2) diethylene glycol as a diol component being from 1.0 to 2.5 mol %,(3) the intrinsic viscosity being from 0.60 to 1.50 dl/g,(4) the concentration of terminal carboxyl groups being at most 18 eq/ton, and(5) the content of a cyclic trimer being at most 0.40% by weight.

Abstract: Provided is a coating composition for a two-piece can containing a polyester resin (A) consisting essentially of terephthalic acid and propylene glycol and containing tri- or more functional polycarboxylic acid or polyol comonomer(s) and an alkyl-etherified aminoformaldehyde resin (B); and the coating film (C) to be obtained by reacting these (A) and (B) in the composition has larger tensile strength and elongation than the film made of only (A). The coating composition is coated on at least one surface of a metal sheet to give a coated metal sheet for a two-piece can. The coated metal sheet may be formed into a drawn and ironed can or a drawn and re-drawn can. The adhesiveness of the coated film to the metal sheet is high, and the coated film has excellent resistance to blistering and resistance to whitening and has excellent flavor preservability.

Abstract: The present invention relates to polyesters capable to give moldings having excellent flow characteristics, heat resistance and mechanical properties.These polyesters are prepared by copolymerizing specified amounts of specific dioxycompounds such as t-butylhydroquinone, phenylhydroquinone and so on with polyesters comprising specified amounts of p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, hydroquinone and terephthalic acid or terephthalic acid and isophthalic acid.

Abstract: Hard resinous polyol esters having a high degree of hydroxyl functionality and a ball and ring softening temperature of at least about 50.degree. C.

Abstract: This invention relates to a polymer blend comprising water-dissipatable, sulfonate containing, a hydantoin-formaldehyde resin.

Abstract: Low-crystallization-speed polyesters obtained by means of the polycondensation of 2,6-naphthalene-dicarboxy acid with at least one (C.sub.2 -C.sub.10)-(cyclo)alkylene glycol in the presence of 0.5-50 mol % of a copolymerizable reactant of general formula:ROOC--Ar--OOC--Ar'--COO--Ar--COOR (I)wherein Ar and Ar' stand for aromatic radicals, and R stands for a hydrogen atom or a (C.sub.1 -C.sub.4)-alkyl radical, or the OR group is replaced by a halogen.

Abstract: A copolyester which comprises, as main components, terephthalic acid as a dicarboxylic acid component and ethylene glycol as a diol component and which is characterized by:(1) isophthalic acid as a dicarboxylic acid component being from 0.5 to 3.0 mol %,(2) diethylene glycol as a diol component being from 1.0 to 2.5 mol %,(3) the intrinsic viscosity being from 0.60 to 1.50 dl/g,(4) the concentration of terminal carboxyl groups being at most 18 eq/ton, and(5) the content of a cyclic trimer being at most 0.40% by weight.

Abstract: The invention is concerned with novel water-dispersible copolymers which contain at least one UVA light-absorbing monomer, one UVB light-absorbing monomer, one hydrophilic monomer, and optionally one hydrophobic monomer component. The UVA light-absorbing monomer absorbs at .lambda.max ultraviolet light in the 320-400 nm range. The UVB light-absorbing monomer absorbs at max ultraviolet light in the 290-320 nm range. Because of the R.sub.3 group used in the invention, the copolymers of the invention permit higher loading of UV monomers than previously obtainable.

Abstract: The invention is concerned with novel water-dispersible or water-soluble copolymers which contain at least one UVA light-absorbing monomer, one UVB light-absorbing monomer, one hydrophilic monomer, and optionally one hydrophobic monomer component. The UVA light-absorbing monomer absorbs at .lambda.max ultraviolet light in the 320-400 nm range. The UVB light-absorbing monomer absorbs at .lambda.max ultraviolet light in the 290-320 nm range.

Abstract: Copolyesters having an improved combination of barrier, mechanical, thermal and rheological properties and consisting of acylic and glycolic radicals, wherein the acylic radicals derive from at least isophthalic acid and 2,6-naphthalene dicarboxylic acid and at least 90% by mols of the glycolic radicals derive from ethylene glycol.

Abstract: The present invention describes a method for the synthesis of saturated aliphatic polyesters by reaction of saturated or aromatic diacid chlorides with oligomeric aliphatic polyester diols, a method to thermally crosslink membranes prepared from the above saturated aliphatic polyesters, and the use of the crosslinked membranes to separate aromatics from saturates.

Abstract: The present invention relates to a polymer composition comprising a high molecular weight polyester having a glass transition temperature of 50.degree. to 100.degree. C. and a weight average molecular weight of 30,000 to 100,000 and a low molecular weight polyester in linear, amorphous form defined by the formula: ##STR1## said low molecular weight polyester having a glass transition temperature of 55.degree.-65.degree. C., wherein:R is a hydrocarbon radical having 2 to 5 carbons andm is a number which gives the low molecular weight polyester a number average molecular weight of 500 to 2000.

Abstract: A polyester resin comprised of (a) units derived from a terephthalic acid component and/or a isophthalic acid component, (b) 0 to 80 mole %, based on the total carboxylic acid component, of units derived from a diol component represented by the formula: ##STR1## wherein R represents an alkyl group having 2 or 3 carbon atoms, and x and y are integers satisfying the requirement of 2.ltoreq.x+y.ltoreq.6,and (c) 20 to 200 mole %, based on the total carboxylic acid component, of units derived from an aliphatic diol component. The polyester has a weight average molecular weight M.sub.w of 3,000 to 20,000, a number average molecular weight M.sub.n of 1,000 to 10,000, a glass transition temperature T.sub.g of 40.degree. to 70.degree. C., and a softening temperature of 70.degree. to 130.degree. C. The polyester is valuable for a toner.

Abstract: Aliphatic polyesters of 3,4'-biphenyldicarboxylic acid and optionally 4,4'-biphenyldicarboxylic acid are prepared by contacting at least one aliphatic diol having from 2 to 12 carbon atoms with a lower alkyl diester or phenolic diester of 3,4'-biphenyldicarboxylic acid and, optionally, a lower alkyl diester or phenolic diester of 4,4'-biphenyldicarboxylic acid, in the presence of a catalyst at about 180.degree. to about 300.degree. C. These polyesters are suitable for use in making fibers, films, three dimensional molded articles, barrier containers and coatings.

Abstract: Linear saturated copolyesters of terephthalic acid, isophthalic acid, butanediol, and one or more aliphatic diols having at least 13 carbon atoms used as adhesives for the formation of wash-resistant bonds especially for temperature-sensitive materials. Preferably, the melting points of these adhesive compositions are from 50.degree. to 170.degree. C. and their relative viscosities, measured as 1% solutions in meta-cresol at 20.degree. C., are 1.40 to 1.80.

Abstract: Disclosed are polyesters comprised primarily of residues of 4,4'-biphenyldicarboxylic acid, ethylene glycol and 1,4-butanediol. Articles injection-molded from the polyesters exhibit a unique combination of properties including unusually high tensile strength and excellent heat resistance, flexural modulus and resistance to chemicals and solvents.

Abstract: A thermotropic liquid crystal polyester consisting essentially of ethylene glycol residue, terephthalic acid residue and parahydroxybenzoic acid residue wherein the mol ratio of ethylene glycol residue to terephthalic acid residue is substantially about 1:1 and the mol ratio of terephthalic acid residue to parahydroxybenzoic acid residue is in the range of about 5:95 to about 25:75, the polyester having an intrinsic viscosity of at least about 0.5 dl/g measured in a 50:50 by weight solvent mixture of phenol and 1,1,2,2-tetrachlorethane at 20.degree. C., and a transmittance of at least about 80% to 530 nm light at a light path length of said solvent mixture. A method for forming the thermotropic liquid crystal polyester is also disclosed.

Abstract: New Z-stilbene compounds and a process for their preparation are disclosed wherein the compounds correspond to the following formulae: ##STR1##

Abstract: Disclosed is a crosslinked polyester resin comprised of, based on the total acid units, (a) 1 to 30 mole % of units of a trihydric or higher alcohol or units of a trivalent or higher carboxylic acid, (b) 1 to 60 mole % of units of an alicyclic diol in which at least one alcohol component is a secondary alcohol, (c) 40 to 100 mole % of units of an aromatic dicarboxylic acid and (d) 40 to 99 mole % of units of a non-alicyclic diol, wherein the acid value is 0.5 to 25 mg-KOH/g, the glass transition temperature is 50.degree. to 80.degree. C., the softening temperature is not higher than 145.degree. C., the fixing-possible temperature covers a range of at least 30.degree. C., and the difference between the softening temperature and the glass transition temperature is not larger than 75.degree. C. The crosslinked polyester is used for toner for electrostatic recording.

Abstract: The present invention is connected with a process for preparing a novel photosensitive polyimide precursor having excellent shelf stability and high sensitivity and containing less impurities.The process for preparing a photosensitive heat-resistant polymer containing a repeating unit represented by the formula (III) comprises the step of reacting a photosensitive group-containing isoimide represented by the formula (I) with a diamine represented by the formula (II) at a temperature of 0.degree. to 100.degree. C. in the presence of a solvent: ##STR1## wherein R.sup.1 is independently a tetravalent carbon cyclic aromatic group or heterocyclic group; R.sup.2 is independently an aliphatic group having at least 2 carbon atoms, an alicyclic group, an aromatic aliphatic group, a carbon cyclic aromatic group, a heterocyclic group or a polysiloxane group; R.sup.3 is a monovalent organic group having a photosensitive unsaturated group; and D is an oxygen atom or .dbd.N--R.sup.3.