MXPA00006393A - Highly branched polyamide graft copolymers - Google Patents

Abstract

A graft copolymer prepared by a process comprising:graft polymerizing a polyamide-forming monomer selected from the group consisting of lactams, .omega.-aminocarboxylic acids and combination thereof, and an oligocarboxylic acid selected from the group consisting of from 0.015 to about 3 mol.%of dicarboxylic acid and from 0.01 to about 1.2 mol.%of tricarboxylic acid, in each case the stated amounts of oligocarboxylic acid based on a molar amount of lactam, .omega.-aminocarboxylic acid or combination thereof, onto from 0.5 to 25%by weight, based on the graft copolymer, of a polyamine having at least 11 nitrogen atoms and a number-average molecular weight Mn of at least 500 g/mol., wherein the amino group concentration in the graft copolymer ranges from 100 to 2500 mmol./kg.

Description

COPO IMITIZADOS DE INGERTO DE POLIA IDA HIGHLY RAMIFIED The invention relates to highly branched polyamide graft copolymers, which consist of a portion of polyamine and polyamide chains in jeopardy. The graft copolymers based on polyamine and polyamide are known. They can be obtained, for example, by the cationic polymerization of caprolactam in the presence of dendrimers of polyethyleneimine hydrochloride as a nuclear molecule (J.M. Warakomski, Chem. Mater. 1992, 4, 1000-1004). Compared to PA 6, this type of PA6 dendrimers has a clearly reduced melt and dissolution viscosity, and maintains the tensile strength, stiffness, melting points, heats of fusion and barrier action regarding oxygen. Polyvinylamine and polyamide-based graft copolymers are known from US Pat. No. 2 615 863. Graft copolymers are described in US Pat. No. 3,442,975. which are obtained by polymerization of lactams in the presence of high molecular weight polyethylenimine. German Patent DE-OS 19 15 772 discloses blends of a polyimino / polyamide graft copolymer, as well as a polyolefin and / or polyester, which can be processed to obtain fibers that can be easily dyed. Finally, German Patent DE-OS 196 54 179 discloses polyamides in the form of "H", which can be obtained from lactams, or aminocarboxylic acids, an at least trifunctional amine, difunctional and monofunctional carboxylic acids , these last two being with each other and with respect to the functional groups of the amine, at least trifunctional, in a certain proportion. The products have a better fusion stability. However, in many applications in which it is desired to use this type of polyamide graft copolymer, it turns out that they do not have sufficient resistance to solvents or fuels. In many cases, resistance to hydrolysis and alcoholysis and resistance to stress cracking, but also the swelling behavior and solidity of dimensions linked to the above, as well as the blocking action against diffusion are unsatisfactory. Thus, there is the objective of providing polyamine-polyane graft copolymers that are more resistant to solvents and fuels. This object is achieved according to the invention with a graft copolymer, which is obtained using the following monomers: a) 0.5 to 25 weight percent, preferably 1 to 20 weight percent and in particular 1.5 to 16 weight weight percent, based on the graft copolymer, of a polyamine with at least 11 nitrogen atoms and an average molecular weight Mn of at least 500 g / mol and preferably of at least 800 g / mol; b) monomers forming polyamides, selected from lactams and? -aminocarboxylic acids; c) oligocarboxylic acid, selected from dicarboxylic acid 0.015 up to about 3 mole percent and tricarboxylic acid 0.01 to about 1.2 mole percent, respectively based on lactam or α-aminocarboxylic acid; wherein the concentration of the amino groups of the graft copolymer is in the range of 100 to 2500 mmoles / kg. The upper limit indicated for the dicarboxylic acid, or tricarboxylic acid, must not only guarantee the preparation not of a crosslinked graft copolymer, but thermoplastic. According to current knowledge, these upper limits constitute a good guiding value. However, in specific cases, especially when relatively high amounts of polyamine are used, even larger amounts of oligocarboxylic acid can be added. As polyamine, for example, the following classes of substances can be used: polyvinylamines (Rummp Chemie Lexikon, 9. Auflage, Band 6, page 4921, Georg Thieme Verlag Stuttgart 1992.).; - polyamines, which are obtained from alternating polyketones (German Patent DE-OS 196 54 058); dendrimers such as ((H2N- (CH2) 3) 2N- (CH2) 3) iN (CH2) 2-N ((CH2) 2-N ((CH2) 3-NH2) 2) 2 (German Patent DE-A -196 54 179), or 3, 15-bis (2-aminoethyl) -6, 12-bis [2- [bis (2-aminoethyl) amino] ethyl] -9- [2- [bis [2-bis] 2-aminoethyl) amino] ethyl] amino] ethyl] 3, 6, 9, 12, 15-pentaazaheptadecan-1, 17-diamine (JM Warakomski, Chem. Mat. 1992, 4, 1000-1004); linear polyethyleneamines, which can be obtained by polymerization of 4,5-dihydro-l, 3-oxazoles and subsequent hydrolysis (Houben-Weyl, Methoden der Organischen Chemie, Band E20, pages 1482-1487, Georg Thieme Verlag Stuttgart, 1987); branched polyethyleneimines, which can be obtained by the polymerization of aziridines (Houben-Weyl, Methoden der Organischen Chemie, Band E20, pages 1482-1487, Georg Thieme Verlag Stuttgart, 1987) and who, in general, have the following distribution of amino groups: 25 to 46 percent of primary amino groups , 30 to 45 percent of secondary amino groups, and 16 to 40 percent of tertiary amino groups. In the preferred case, the polyamine has an average molecular weight Mn of not more than 20,000 g / mol, especially of a maximum of 10,000 g / mol and in particular of a maximum of 5,000 g / mol. The lactams, or the? -aminocarboxylic acids, which are used as monomers forming polyamides, contain 4 to 19 and in particular 6 to 12 carbon atoms. Especially preferred are e-caprolactam, e-aminocaproic acid, capryllactam, α-aminocaprylic acid, laurinlactam, α-aminododecanic acid and / or α-amino-decanoic acid. As the oligocarboxylic acid, any di- or tricarboxylic acid with 6 to 24 carbon atoms can be used, for example, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanic diacid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, cyclohexane acid. -1.4 -dicarboxylic acid, trimesinic acid and / or trimellitic acid. If a dicarboxylic acid is used, 0.03 to 2.2 mole percent, especially 0. 05 to 1.5 mole percent, in particular 0.1 to 1 mole percent and very particularly 0.15 to 0.65 mole percent; if a tricarboxylic acid is used, 0.02 to 0.9 are preferably employed per mole percent, especially 0.025 to 0.6 mole percent, in particular 0.03 to 0.4 mole percent and very particularly 0.04 to 0.25 mole percent. Tricarboxylic acid is used mainly when it is desired to obtain extrudable molding compositions with high melt stiffness. If desired, aliphatic, alicyclic, aromatic, aralkyl and / or alkylaryl-substituted monocarboxylic acids having 3 to 50 carbon atoms, such as lauryl acid, unsaturated fatty acids, acrylic acid or benzoic acid, can also be used as regulators. With these regulators, the concentration of the amino groups can be reduced without modifying the molecular configuration. In this way, functional groups such as double or triple bonds, etc. can optionally be introduced. However, it is necessary to note that the graft copolymer possesses a substantial portion of amino groups. The concentration of amino groups of the graft copolymer is preferably in the range of 150 to 1500 mmole / kg, in particular in the range of 250 to 1300 mmole / kg and in particular in the range of 300 to 1100 mmole / kg. In this case and hereinafter, amino groups are understood not only amino end groups, but also secondary or tertiary amino functions of the polyamine optionally present. The graft copolymers according to the invention can be obtained according to various methods. One possibility is to arrange together lactam, or,? -aminocarboxylic acid and polyamine and carry out the polymerization, or, the polycondensation. Oligocarboxylic acid can be added either at the beginning or during the course of the reaction. Another procedure is that, in a two-stage process, the lactam dissociation and the prepolymerization are first carried out in the presence of water (alternatively the corresponding amino-carboxylic acids are directly used and prepolymerized, in the second step it is added polyamine, while oligocarboxylic acid is dosed before, during or after prepolymerization, then expanded to temperatures between 200 and 290 ° C and is either polycondensed under nitrogen flow or under vacuum. hydrolytic degradation of a polyamide, which is derived from one or more lactams, or? -aminocarboxylic acids, to obtain a prepolymer and simultaneously or subsequently, reacting with the polyamine. Preferably polyamides are used, in which the difference of final groups is approximately zero, or in which the oligocarboxylic acid is already incorporated by polycondensation. However, the oligocarboxylic acid can also be added at the beginning or in the course of the degradation reaction. With these processes, highly branched polyamides with acid levels lower than 40 mmoles / kg, preferably lower than 20 mmoles / kg and in particular lower than 10 mmoles / kg can be obtained. Already from reaction times of one to five hours at temperatures of 200 ° C to 290 ° C, an almost complete reaction is achieved. If desired, in a further step of the process a subsequent vacuum phase of several hours can be carried out. This lasts at least four hours, preferably at least six hours and in particular at least eight hours at 200 to 290 ° C. After an induction period of several hours, an increase in the melt viscosity is observed, which could have its origin in that a reaction of amino end groups takes place with each other producing the dissociation of ammonia and a chain link . Thus, the molecular weight is further increased, which is advantageous in particular for extrusion molding compositions. If it is not desired to terminate the reaction in the melt, the highly branched polyamide according to the invention can also be further condensed into a solid phase. The graft copolymers according to the invention can be used in injection or extrusion molding compositions. However, they can also be used as a mixture component for the modification of use properties or as thermoplastic adhesives. The results indicated in the examples were determined with the help of the following measurement procedure. To determine the final carboxylic groups, 1 g of graft copolymer in 50 ml of benzyl alcohol was dissolved under nitrogen at 165 ° C. The dissolution time was maximum 20 minutes. The solution was titrated until the color change with a KOH solution in ethylene glycol (0.05 moles KOH / 1) against phenolphthalein. For the determination of the amino groups, 1 g of graft copolymer in 50 ml of m-cresol was dissolved at 25 ° C. The solution was titrated potentiometrically with perchloric acid. The determination of the solution viscosity? Re? (Relative viscosity) was carried out at 25 ° C using a 0.5 percent m-cresol solution, according to DIN 53727 / ISO 307. Comparative example 1 (without oligocarboxylic acid): In a heating kettle they were melted at 180 ° C. up to 210 ° C 4.75 kg of laurinlactam and were transferred to a pressure resistant polycondensation kettle. Then 250 ml of water and 57 ppm of hypophosphorous acid were added. The dissociation of laurinlactam was performed at 280 ° C under the proper pressure that is adjusted. Then, it was expanded in 3 hours to a residual steam pressure of 3 bar and 250 g of polyethyleneimine (Lupasol G 100, polyethylenimine from BASF AG, Ludwigshafen) were added. Subsequently, it was expanded to normal pressure and polycondensed for 2 hours at 250 ° C under nitrogen flow. The clear melt was discharged as a skein through a melt pump, cooled in a water bath and then granulated. ? rei: 1-58 Melting temperature Tm: 170 ° C Amine group concentration: 879 mmoles / kg Concentration of final carboxylic groups: < 10 mmole / kg Example 1 (with 0.27 mole percent dodecanic diacid referring to laurinlactam): Worked as in comparative example 1 with the only difference that 15 g of dodecanic diacid were added together with the polyethylenimine. ? re ?: 1.52 Melting temperature Tm: 170 ° C Amine group concentration: 837 mmoles / kg Concentration, of final carboxylic groups: < 10 mmole / kg Example 2 (with 0.15 mole percent of trimesinic acid referred to laurinlactam): Worked as in comparative example 1 with the only difference that together with the polyethylenimine 7.5 g of trimesinic acid were added. ? re ?: 1.56 Melting temperature Tm: 173 ° C Amine group concentration: 790 mmol / kg Concentration of final carboxylic groups: < 10 mmoles / kg Table 1 compares the resistance to solvents of the products obtained from each other. For this, they were stored at 80 ° C for 5 or 10 days, shot in a mixture of 42.5 volume percent toluene, 42.5 volume percent isooctane and 15 volume percent methanol at 80 ° C and then they dried. Then the relative viscosity was determined? Re? using a 0.5 percent solution in m-cresol at 25 ° C, according to DIN 53727 / ISO 307. In the products according to the invention no alcohol degradation was observed.

Table 1: Resistance to solvents Storage time Comparative example 1 Example 1 Example 2 [days]? Re? ? rel? rel 0 1.58 1.52 1.56 5 1.42 1.52 1.56 10 1.3E 1.52 1.56 Example 3 (with 1.2 mole percent dodecanic diacid related to laurinlactam) In a pot with heating, 47.75 kg of laurinlactam and 0.675 kg of dodecanic diacid were melted at 180 to 210 ° C and passed to a pot of polycondensation resistant to the pressure. Subsequently, 2.5 kg of water and 57 ppm of hypophosphorous acid were added. The dissociation of laurinlactam was carried out at 280 ° C under the proper pressure that is adjusted. Then, it was expanded in 3 hours to a residual water vapor pressure of 5 bar and 2.25 kg of polyethyleneimine (Lupasol G 100, BASF AG, Ludwigshafen) were added. Subsequently, it was expanded to normal pressure and polyadenized for 2 hours at 2.80 ° C under nitrogen. The clear melt was discharged as a skein through a spinning lathe pump, cooled in a water bath and then granulated. ? re ?: 1.60 Melting temperature Tm: 172 ° C Amine group concentration: 720 mmoles / kg Concentration of final carboxylic groups: 16 mmoles / kg

Claims (10)

1. A graft copolymer obtained using the following monomers: a) 0.5 to 25 weight percent based on the graft copolymer, of a polyamine with at least 11 nitrogen atoms and an average molecular weight Mn of at least 500 g / mol; b) polyamide-forming monomers, selected from actamas and? -aminocarboxylic acids; c) oligocarboxylic acid, selected from dicarboxylic acid 0.015 up to about 3 mole percent and tricarboxylic acid 0.01 to about 1.2 mole percent, respectively based on lactam or α-aminocarboxylic acid; wherein the concentration of the amino groups of the graft copolymer is in the range of 100 to 2500 mmoles / kg.

2. A graft copolymer according to claim 1, characterized in that the oligocarboxylic acid is selected from dicarboxylic acid 0.03 to 2.2 mole percent and tricarboxylic acid 0.02 to 0.9 mole percent.

3. A graft copolymer according to claim 1, characterized in that the oligocarboxylic acid is selected from dicarboxylic acid 0.05 to 1.5 mole percent and tricarboxylic acid 0.025 to 0.6 mole percent.

4. A graft copolymer according to claim 1, characterized in that the oligocarboxylic acid is selected from dicarboxylic acid 0.1 to 1 mole percent and tricarboxylic acid 0.03 to 0.4 mole percent. A graft copolymer according to claim 1, characterized in that the oligocarboxylic acid is selected from dicarboxylic acid 0.1 to 0.65 mole percent and tricarboxylic acid 0.04 to 0.25 mole percent. 6. A graft copolymer according to any of the preceding claims, characterized in that the concentration of the amino groups is in the range of 150 to 1500 mmoles / kg. 7. A graft copolymer according to claim 6, characterized in that the concentration of the amino groups is in the range of 250 to 1300 mmoles / kg. 8. A graft copolymer according to any of the preceding claims, characterized in that the concentration of the amino groups is in the range of 300 to 1100 mmol / kg. 9. A graft copolymer according to any of the preceding claims, characterized in that the polyamine is a branched polyethyleneimine, which has the following distribution of amino groups: 25 to 46 percent of primary amino groups, 30 to 45 percent of secondary amino groups, and 16 to 40 percent of tertiary amino groups. 10. A graft copolymer according to any of the preceding claims, characterized in that its acid value is less than 40 mmoles / kg.