Abstract: A polymerizable composition comprising a) at feast one cyclic amide, b) from 2.8 to 3.5% by weight, preferably from 2.9 to 3.1% by weight, of at least one blocked polyisocyanate, and c) from 1.2 to 1.4% by weight of at least one catalyst for the polymerization of the cyclic amide, where the ratio by weight of components b) to c) is from 2.0 to 2.9 and the % by weight data are always based on the entirety of components a) to c).

Abstract: The invention relates to a method for preparing a compound comprising two phenyl groups by reacting a bisfuranic compound with a dienophile; and to such compounds.

Abstract: The present invention relates to a method for preparing a polyamide resin, comprising the steps of: (a) preparing a polyamide polymer by anionically polymerizing a monomer including 2-pyrrolidone; (b) refining an unreacted monomer and a catalyst in the polyamide polymer with water; (c) pH-controlling through an ion exchange of the refined water; and (d) recovering the unreacted monomer by concentrating the pH-controlled water.

Abstract: Supramolecular polymers having repeat units connected by hydrogen bonds, where the repeat units are monomers, macromers, oligomers or polymers where at least one on the monomers contains at least one 2,5-diketopiperazine group are described. Composition prepared from these supramolecular polymers and articles produced from these compositions are also described.

Abstract: The invention relates to a copolyamide comprising at least two different units corresponding to the following general formulation: A/X.T A is chosen from a unit obtained from an amino acid, a unit obtained from a lactam and a unit corresponding to the formula (Ca diamine).(Cb diacid), with a representing the number of carbon atoms of the diamine and b representing the number of carbon atoms of the diacid, a and b each being between 4 and 36, advantageously between 9 and 18, X.

Abstract: Biodegradable saturated and unsaturated polyester amides (PEA)s made from multiamino acid monomers and methods of making biodegradable saturated and unsaturated PEAs.

Abstract: The present invention relates to a process for producing moldings comprising (A) at least one lactam, (B) at least one activator, and (C) at least one catalyst, where (A) to (C) proceed through treatments comprising a) mixing of (A), (B), and (C), b) metering of (A), (B), and (C) into an apparatus for producing mixture droplets, and producing mixture droplets, and c) depositing the mixture droplets comprising (A), (B), and (C) on a belt, and d) producing moldings.

Abstract: The invention relates to a process for producing a shaped article having excellent mechanical properties, said article comprising a block copolymer PAX.Y/PE comprising polyamide (PA) blocks alternating with polyether (PE) blocks, prepared from homopolyamide blocks PAX.Y by polycondenstation of linear aliphatic diamines where PAX.Y is selected from the group consisting of PA 10,12; PA 6,18; PA 10,14; and PA 12.12, reacted with polyether PE blocks in the presence of a catalyst to produce a block copolymer PAX.Y/PE, wherein said PE blocks are either PE diols, or PE blocks comprising NH2 ends. The articles formed are either a fabric, film, sheet, rod, pipe, injection-molded component, or a shoe sole; the copolymer PAX.Y/PE has an improved flexural modulus of at least 300 MPa greater than a copolymer polyamide 12/polytetrametylene with the same size of PA block and with the same size of PE block respectively.

Abstract: The present invention relates to a new method of production of cast polyamides.

Abstract: A process for making a polyamide polymer, said process comprising heating, in one or more ionic liquid(s), one or more polyamide precursor(s) selected from: (i) one or more free dicarboxylic acid(s) or ester(s) thereof, with one or more diamine(s); or (ii) one or more salt(s) of a dicarboxylic acid with a diamine; or (iii) one or more lactam(s); or (iv) mixtures of any of the foregoing precursors (i) to (iii).

Abstract: Polyamides, e.g., polyhexamethylene adipamide, are continuously produced via the following stages: Stage 1: into and through a reactor, polycondensing a liquid stream which contain the polyamide monomer(s) at a pressure P1 greater than atmospheric pressure, the stream of material at the outlet of the reactor including a vapor phase which contains steam and a liquid phase which at least contains the product of polycondensation; Stage 2: feeding the outlet stream of material into a chamber, evacuating at least a portion of the vapor phase therefrom and recovering at least the liquid phase which at least contains the product of polycondensation, the pressure P2 in the chamber being regulated at a set value such that it is greater than atmospheric pressure and the residence time of said liquid phase in the chamber being less than 5 minutes; and Stage 3: pressure reducing at least the liquid phase which at least contains the stream of polycondensation product recovered during Stage 2.

Abstract: The process for preparing a polyamide based on dicarboxylic acids and diamines has the following stages: 1) providing an aqueous monomer mixture of dicarboxylic acids and diamines, the molar ratio of dicarboxylic acids to diamines being adjusted such that a molar deficiency of dicarboxylic acids or diamines of from 1 to 10 mol % is present at the outlet of stage 3), based on the other component in each case, 2) transferring the aqueous mixture from stage 1) to a continuous evaporator reactor in which diamines and dicarboxylic acids are reacted at a temperature in the range from 100 to 370° C. and a pressure in the range from 1 to 50 bar, 3) transferring the mixture from stage 2) to a separator which is operated at a temperature in the range from 100 to 370° C.

Abstract: The invention relates to a copolyamide comprising at least two different units corresponding to the following general formulation: A/X.T A is chosen from a unit obtained from an amino acid, a unit obtained from a lactam and a unit corresponding to the formula (Ca diamine).(Cb diacid), with a representing the number of carbon atoms of the diamine and b representing the number of carbon atoms of the diacid, a and b each being between 4 and 36, advantageously between 9 and 18, X.

Abstract: A polyamide compound containing from 0.1 to 50 mol % of a diamine unit that contains at least 50 mol % of a linear aliphatic diamine unit represented by the following general formula (I), from 0.1 to 50 mol % of a dicarboxylic acid unit that contains a linear aliphatic dicarboxylic acid unit represented by the following general formula (II-1) and/or an aromatic dicarboxylic acid unit represented by the following general formula (II-2) in an amount of at least 50 mol % in total, and from 0.1 to 50 mol % of a constituent unit represented by the following general formula (III): [In the above-mentioned general formulae (I) and (II-1), m and n each independently indicate an integer of from 2 to 18. In the general formula (II-2), Ar represents an arylene group. In the general formula (III), R represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

Abstract: The present invention relates to a composition that can be used to manufacture an impermeable, sealing, tight envelope, to a process for manufacturing an impermeable envelope, and to a tank. The composition of the invention comprises in % by weight relative to the total weight of the composition: from 70 to 90% of a monomer (I); from 0.1 to 1% of an activator (II), in which R is chosen from the group comprising CnH2n+2, n being an integer chosen from 1 to 10; —OH; —OCnH2n+2, n being an integer chosen from 1 to 10; and —NHR? where R? is either CnH2n+2, n being an integer chosen from 1 to 10, or an amine functional group; from 2 to 6% of a catalyst (III), in which X is chosen from the group comprising MgBr, MgI, Li and Na; and from 10 to 20% of an additive (IV), with: This composition can be used, for example, to manufacture elements that are impermeable to fluids, for example impermeable envelopes, for example that can be used in the manufacture of type IV tanks or hydraulic accumulators.

Abstract: This invention relates to poly(ester amide)s (PEAs) comprising inactivated terminal amino and carboxyl groups, methods of synthesizing the inactivated PEAs and uses for them in the treatment of vascular diseases.

Abstract: A method of forming a polyamide composition includes melt blending specific amounts of a poly(phenylene ether) masterbatch, a first polyamide, glass fibers, and a flame retardant that includes a metal dialkylphosphinate. The poly(phenylene ether) masterbatch is prepared by melt blending specific amounts of a poly(phenylene ether) and a second polyamide. The method provides a polyamide composition with a desirable balance of flame retardancy, melt flow, heat resistance, and mechanical properties, while reducing the amount of metal dialkylphosphinate required by corresponding compositions without the poly(phenylene ether) masterbatch. A corresponding polyamide composition is described, as are the poly(phenylene ether) masterbatch, and a method of reducing the metal dialkylphosphinate content of a flame retardant polyamide composition.

Abstract: A polyamide compound containing from 50 to 99.9 mol % of an ?-aminocarboxylic acid unit represented by the following general formula (I), and from 0.1 to 50 mol % of a constituent unit represented by the following general formula (II): [In the general formula (I), m indicates an integer of from 2 to 18. In the general formula (II), R represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

Abstract: The present invention relates to a process for producing moldings comprising (A) at least one lactam, (B) at least one activator, and (C) at least one catalyst, where (A) to (C) proceed through treatments comprising a) mixing of (A), (B), and (C), b) metering of (A), (B), and (C) into an apparatus for producing mixture droplets, and producing mixture droplets, and c) depositing the mixture droplets comprising (A), (B), and (C) on a belt, and d) producing moldings.

Abstract: Supramolecular polymers having repeat units connected by hydrogen bonds, where the repeat units are monomers, macromers, oligomers or polymers where at least one on the monomers contains at least one 2,5-diketopiperazine group are described. Composition prepared from these supramolecular polymers and articles produced from these compositions are also described.

Abstract: Polyamide containing a compound which bears at least one hydroxy group and has chemical bonding by way of an amide group to the end of the polymer chain, process for preparing this polyamide, and also fibers, films, and moldings, comprising at least one such polyamide.

Abstract: A process for crosslinking polyamides by reacting a compound of the general formula R1R2C?CR3—X in which R1, R2 and R3 are each independently hydrogen or an organic radical with a lactam A at a temperature of (?30) to 150° C., and then reacting with a lactam B, a catalyst and an activator at a temperature of 40 to 240° C.

Abstract: A process for producing an activated monomer composition comprising at least one lactam and/or lactone, one catalyst, and one activator permits storage of the resultant monomer composition, since this is stable with respect to polymerization. Said monomer composition is used inter alia in producing a polyamide molding via ring-opening, anionic polymerization.

Abstract: Methods of making copolymers are described.

Abstract: The present invention relates to a method for reducing the crystallization temperature an the melting temperature of a polyamide powder resulting from the polymerization of at least one predominant monomer, in which the reduction in the crystallization temperature is greater than the reduction in the melting temperature, said method comprising a step of polymerization of said at least one predominant monomer with at least one different minor comonomer polymerized according to the same polymerization process as said at least one predominant monomer, said at least one minor comonomer being chosen from aminocarboxylic acids, diamine/diacid pairs, lactams and/or lactones, and said at least one minor comonomer representing from 0.1% to 20% by weight of the total blend of said monomers(s) and comonomer(s), preferably from 0.5% to 15% by weight of said total blend, preferably from 1% to 10% by weight of said total blend.

Abstract: A continuous process for producing polyamides, their oligomers or mixtures thereof, if appropriate with further reaction products, comprises reaction of aminonitriles or dinitriles and diamines or mixtures thereof, if appropriate together with further polyamide-forming monomers and/or oligomers, with an aqueous medium composed of aqueous monomer and oligomer extracts obtained from polyamide production by extraction of the polymer with water in a reactor which has a vertical longitudinal axis and through which there is a flow substantially in the longitudinal direction wherein water and/or the aqueous medium are introduced into the reactor at two or more different locations along the vertical longitudinal axis, wherein the aqueous medium is introduced at one or more locations.

Abstract: The invention relates to a composition, and structures having a layer made of said composition, in which the composition is, by weight, the total being 100%: 50 to 100% of at least one polyamide A1 of formula X.Y/Z or 6.Y2/Z in which: X denotes the residues of an aliphatic diamine having from 6 to 10 carbon atoms, Y denotes the residues of an aliphatic dicarboxylic acid having from 10 to 14 carbon atoms, Y2 denotes the residues of an aliphatic dicarboxylic acid having from 15 to 20 carbon atoms and Z denotes at least one unit chosen from the residues of a lactam, the residues of an ?,?-aminocarboxylic acid, the unit X1, Y1 in which X1 denotes the residues of an aliphatic diamine and Y1 denotes the residues of an aliphatic dicarboxylic acid, the weight ratios Z/(X+Y+Z) and Z/(6+Y2+Z) being between 0 and 15%; 0 to 40% of a plasticizer; 0 to 50% of an impact modifier; and 0 to 50% of a polyamide A2.

Abstract: Polyamide, whose main chain contains a chemically bound amine selected from the group consisting of 2-methyl-1,5-diaminopentane and 1-amino-2-R-cyclopent-1-ene, where R is a functional group capable of combining with an amino group to form an amide group, and processes for preparing such a polyamide and fibers, films and moldings comprising such a polyamide.

Abstract: A method for preparing nylon microspheres is provided, said method comprising steps (1), (2) and (3) or steps (1?), (2) and (3) as follows: (1) a radically polymerizable monomer is dispersed in a molten lactam monomer, and a free radical initiator is added, so that radical polymerization of the radically polymerizable monomer is carried out, to give a mixture of a free radical polymer and the lactam monomer; or (1?) a mixture of a free radical polymer and a molten lactam monomer is provided; and (2) an initiator and an activator, used for anionic ring-opening polymerization of the lactam monomer, are added to the mixture obtained in step (1) wherein the remaining radically polymerizable monomer and water are removed, or to the mixture obtained in step (1?), so that the anionic ring-opening polymerization of the lactam is carried out to give a polymer alloy of the free radical polymer/polyamide; and (3) the free radical polymer in the polymer alloy obtained in step (2) is removed by dissolution, giving nylon m

Abstract: The present invention relates to a flexible semiaromatic polyamide composition with a low moisture uptake comprising, by weight, the total being 100: 60 to 99.5% (preferably 70 to 93%) of at least one copolyamide of formula X/Y,Ar in which: Y denotes the residues of an aliphatic diamine having from 8 to 20 carbon atoms, Ar denotes the residues of an aromatic dicarboxylic acid, X denotes either the residues of aminoundecanoic acid NH2—(CH2)10—COOH, of lactam-12 or of the corresponding amino acid, or X denotes the unit Y,x, residue from the condensation of the diamine with an aliphatic diacid (x) having between 8 and 20 carbon atoms, or X denotes the unit Y,I, residue from the condensation of the diamine with isophthalic acid, ?0.5 to 40% (preferably 7 to 30%) of at least one product chosen from plasticizers, nanofillers, polyolefins, crosslinked polyolefins and additives.

Abstract: Thermoplastic molding materials containA) from 5 to 94% by weight of a partly aromatic, semicrystalline copolyamide composed essentially ofa.sub.1) from 30 to 44 mol % of units which are derived from terephthalic acid,a.sub.2) from 6 to 20 mol % of units which are derived from isophthalic acid,a.sub.3) from 43 to 49.5 mol % of units which are derived from hexamethylenediamine, anda.sub.4) from 0.5 to 7 mol % of units which are derived from aliphatic cyclic diamines of 6 to 30 carbon atoms,the molar percentages of components a.sub.1) to a.sub.4) together giving 100% andB) from 5 to 94% by weight of an ASA or ABS or SAN polymer or of a C.sub.1 -C.sub.18 -alkyl ester of (meth)acrylic acid or of a mixture thereof,C) from 1 to 30% by weight of an adhesion promoter which contains from 0.

Abstract: A process for the continuous production of polyamides from a mixture of at least one lactam and water and, if required, other monomer units and/or conventional additives and fillers under polyamide-forming conditions, where the mixture of the starting materials is heated in liquid phase in a first reaction zone until a conversion of at least 70% is reached, and undergoes adiabatic decompression and further polymerization in another reaction zone, wherein, in the first reaction zone, 0.5-7% by weight of water are employed, the temperature is increased to the range from 220.degree. to 310.degree. C., and polymerization is carried out until a conversion of at least 85% is reached and, in the second reaction zone, after the decompression further polymerization is carried out in the range from 215.degree. to 300.degree. C. without heat input.

Abstract: The invention relates to a process for the production of high-molecular-weight polytetramethylene adipamide from equivalent amounts of 1,4-diaminobutane and adipic acid at lower pressures. By supplying 1,4-diaminobutane at an advanced stage of the polycondensation a first polycondensate is obtained that can be extruded very well and that can be aftercondensed in the solid phase to obtain a product with a high molecular weight within a short time. Because of this a substantial overall gain in time is realized. It even appears to be possible to prepare a first polycondensate with a relative viscosity that is high enough for the polycondensate to be further processed into shaped objects.The polycondensation can be carried out both in the melt and in solution.The diaminobutane can be supplied both via the liquid and via the vapour phase.

Abstract: Thermoplastically processable elastomeric block copolyetheresteretheramides from recurring units of the formula ##STR1## in which ##STR2## represents a polyamide segment containing terminal carboxyl groups and having an average molar mass of 700 to 10 000, --O--E--O-- is a poly-(oxytetramethylene)-segment having an average molar mass of 600 to 3 500, --NH--F--NH-- represents a poly-(oxy-1,2-propylene)-segment containing terminal amino groups and having an average molar mass of 350 to 2 500, x and y are integers from 3 to 35 and indicate the number of the respective, randomly arranged, recurring units, the ratio x:y of components A and B varying between 5:1 and 1:5.The ether amides of the present invention can optionally be mixed with additives, fillers, modifiers, or other compatible polymers normally used in the processing of polyamides and which are suitable for the production of molded articles, for example by injection molding, coinjection, extrusion, blow molding, etc.

Abstract: Molding materials are composed ofA) from 40 to 100% by weight of a copolyamide based ona.sub.1) from 1 to 20 mol%, based on the copoly- amide, of at least one monomer that contains at least one olefinic double bond (monomers a.sub.1) from the group of the.alpha..sub.1) olefinically unsaturated lactams,.alpha..sub.2) olefinically unsaturated aminocarboxylic acids,.alpha..sub.3) olefinically unsaturated dicarboxylic acids,.alpha..sub.4) olefinically unsaturated diamines, anda2) from 80 to 99 mol%, based on the copolyamide, of at least one monomer that contains no olefinic double bonds (monomers a2) from the group of the.beta..sub.1) lactams.beta..sub.2) aminocarboxylic acids,.beta..sub.3) dicarboxylic acids,.beta..sub.4) diamines, andB) from 0 to 35% by weight of an impact modifying rubber,C) from 0 to 50% by weight of a filler and/or reinforcing agent,D) from 0 to 20% by weight of a flame retardant, andE) from 0 to 10% by weight of further additives and processing aids.

Abstract: Nylon 66 polymer is prepared by condensation of a reaction mixture containing 1,8-diazacyclotetradecane-2,7-dione and nylon 66 salt and/or caprolactam.

Abstract: A method for producing a sliding coupling, w hich comprises injecting a casting material comprising the following components (A) and (B) into a clearance between a bearing and a shaft fitted in and rotatably or reciprocatively supported by the bearing, wherein a primer is preliminarily applied to either the shaft or the bearing and a releasing agent is preliminarily applied to the other; followed by polymerization and curing to form a resin lining on the surface of the shaft or the bearing:(A) a .OMEGA.-lactam liquid containing a polymerization catalyst of an alkali metal or alkaline earth metal compound; and(B) a .OMEGA.-lactam liquid containing at least one polymerization initiator.

Abstract: A process for preparing a co-poly(amide/peptide) by reacting polymeric or oligomeric polypeptides and polymeric or oligomeric polyamides in the presence of an effective amount of one or more aryl phosphoryl azide compounds.

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: A polyether-polyamide block copolymer having an ethylenically unsaturated group represented by formula (I): ##STR1## wherein symbols are as defined in the specification; and a polyether prepolymer represented by formula (II): ##STR2## wherein the symbols are as defined in the specification, which is a starting material for synthesizing the above polyether-polyamide block copolymer, are disclosed. The polyether-polyamide block copolymer exhibits improved heat stability while retaining excellent characteristics inherent to polyether-polyamide.

Abstract: This invention relates to modified polyetheramide hotmelt adhesives showing reduced melt viscosity and, optionally, better adhesive properties and to their use as ingredients for hotmelt adhesives.

Abstract: An adhesive copolyamide composition having a dry powder DSC melting point of at least 100.degree. C., a glass transition temperature above 60.degree. C., a dry powder softening point of at least 100.degree. C., preferably a water content after storage in water of more than 20% by weight, and a wet softening point of less than 100.degree.. Such compositions exhibit softening points and heat resistances in excess of 100.degree. C. and can be processed and set at substantially lower temperatures. No low molecular weight additives are required nor are any solvents necessary. The compositions are comparable in their heat-resistance, softening points, and bond strength to conventional high performance hot melt adhesives.

Abstract: A process for preparing a nylon block copolymer which comprises bringing into reactive contact lactam monomer, basic lactam polymerization catalyst and a composition containing one or more lactam functional materials selected from the group represented by the formula: ##STR1## wherein, Q is ##STR2## with Y=C.sub.3 -C.sub.11 alkylene; b is an integer equal to 2 or more;R.sub.1 is an alkyl, aryl, aralkyl, alkyloxy, halogen, aryloxy, or aralkyloxy group;Z is a segment of: (1) a polyether, provided said polyether is not solely polyarylene polyether; (2) a polyester containing polyether or polymeric hydrocarbon segments (3) a hydrocarbon; (4) a polysiloxane; or (5) combinations thereof.

Abstract: N-alkylamide-substituted amines, such as nitrilotripropionamide, are either self-polymerized or copolymerized with other monomers, such as amino acids, in the presence of a stoichiometric amount of aqueous ammonia and at a temperature of at least 200.degree. C. and autogenous pressure to form substantially linear polyamides, such as poly-.beta.-alanine and nylon-3/6.

Abstract: A process for preparing a nylon block polymer which comprises bringing into reactive contact lactam monomer, basic lactam polymerization catalyst and a composition containing one or more acyllactam functional materials selected from the group consisting of: ##STR1## wherein, Q is ##STR2## with Y=C.sub.3 -C.sub.11 alkylene; a is an integer equal to 1, 2 or 3;b is an integer equal to 2 or more;R is a di- or a poly- valent group selected from hydrocarbon groups and hydrocarbon groups containing ether linkages;Z is a segment of: (1) a polyether or polymeric hydrocarbon; (2) a polyester containing polyether segments (3) a hydrocarbon; (4) a polysiloxane; or (5) combinations thereof.

Abstract: The invention relates to laminated films and articles of manufacture based on such films and having improved resistance to heat treatment, wherein said films comprise a heat sealing layer of copolyamide obtained by random copolymerization of precursor monomers of at least two different polyamides. Said laminated films, or the articles of manufacture formed therefrom, such as bags or preformed containers, are useful for packaging applications, particularly in connection with food products.

Abstract: This invention relates to reaction injection molding of a mixture of lactams in presence of a catalyst and a promotor which is carried out by mixing at least two lactams in a liquid state with the catalyst and promoter before injecting the mixture into a preheated mold. The use of a mixture of lactams results in a supercooled mixture which remains liquid at ambient temperature for at least 2 hours.

Abstract: A method of forming an amorphous crystallizable thermoplastic polymer composition. The polymer composition has a modulus of rigidity which decreases to a minimum value with increasing temperature and then begins to increase. The process includes heating polymer to below a temperature at which crystal formation occurs and form the polymer. The polymer composition is then heated to a temperature at which crystal formation can occur and be annealed. This process is useful to make articles having a thickness of from 0.127 cm (0.050 inches) to 1.27 cm (0.50 inches) such as sheets and tubes of the amorphous polymer and then reforming and annealing them.

Abstract: This invention is a transparent alcohol resistant, hot water resistant, thermoplastically formable copolymer of (A) 80.4 to 88.8 weight percent epsilon-caprolactam and the remaining (B) 11.2 to 19.6 weight percent of substantially equimolar portions of a moiety derived from (1) a diamine or diisocyanate and (2) a diacid or (c) 11.2 to 19.6 weight percent para amino benzoic acid.

Abstract: What are disclosed are a polyamide polymer and its use as a melt adhesive for adhering textiles, said polymer having a melt viscosity, measured at 220.degree. C., of 5-150 Pas and being the reaction product of approximately equivalent amounts of an acid component and a basic component, said acid component comprising(a) (1) a dimerized fatty acid having a content of 70-100 percent by weight of dimeric fatty acid and, optionally,(a) (2) a monocarboxylic acid, as a molecular weight regulator, having up to 22 carbon atoms, which monocarboxylic acid may be present in an amount up to 50 equivalent percent of the total carboxy groups of the mixture (a) (1) and (a) (2);(b) at least one aliphatic straight chain co-dicarboxylic acid having 6 to 13 carbon atoms, wherein the ratio of carboxylic acid according to (a) (1) and (a) (2) to carboxylic acid according to (b) is from 0.