MXPA00010632A - Process for preparing hydroxy-functionalized polyesters - Google Patents

Abstract

A process for preparing a thermoplastic hydroxy-functionalized polyester comprises contacting a dicarboxylic acid or a mixture of dicarboxylic acids with a diepoxide in a given solvent in the presence of an end-capping agent and a catalyst under conditions sufficient to form the hydroxy-functionalized polyesters or polyethers.

Description

PROCESS FOR PREPARING POLYESTERS FUNCTION ALIZED WITH H1DROXI This invention relates to a process for preparing polyesters functionalized with hydroxy. When manufacturing polymers, it is convenient to be able to control the molecular weight. Unfortunately, polymers produced from the reaction of diepoxides and diacids, such as adipic acid, over time, exhibit the tendency to increase molecular weight when maintained at polymerization temperatures. This can be a problem since it could take several hours to empty the contents of a reactor, during which time the molecular weight of the polymer increases. This increase in molecular weight occurs even when normal stoichiometric calculations suggest that no molecular weight accumulation should take place. It is known to control the molecular weight by adding a large excess of a mono-functional acid to the content of the reactor when the desired molecular weight has been achieved. The disadvantage of this is that it may be necessary to remove the excess acid or the construction material for the equipment associated with the production may not be compatible with the acids used. The Patent of E.U.A. No. 5,171,820, discloses a process for preparing non-hydroxy functionalized polyesters by allowing a dicarboxylic acid and a diglyceryl ether to react in a solvent containing a quaternary ammonium halide as an initiator.

This patent teaches that a monofunctional carboxylic acid can be added at the end of the polymerization reaction. This end capping step prevents molecular weight accumulation that could occur in some way during an extended heating phase of commercial production, but requires at least 10 weight percent of the monofunctional carboxylic acid to control the molecular weight . It may be convenient to provide a process for preparing hydroxy functionalized polyesters in a given solvent, whereby the molecular weight of the polymer can be controlled using a lower level of a co-terminating agent than those used in the prior art. The present invention is a process for preparing a hydroxy-functional polyester, which comprises reacting dicarboxylic acids and diepoxides in a solvent in the presence of an end capping agent and a catalyst under conditions sufficient to form the functionalized polyethers or polyesters. with hydroxy. One aspect of this invention is the addition of the co-terminating agent at the beginning of the reaction together with the other starting materials. The endcapping agent can be added to the reaction before, or at the point at which the product reaches the maximum peak molecular weight or maximum number average molecular weight.

It has been found that the addition of the terminating agent at the beginning of the reaction decreases the amount of monofunctional acids required to control the molecular weight of the polymer. It has also been found that the addition of the co-terminating agent at the beginning of the reaction results in a more stable end product (with respect to excess molecular weight accumulation) than if the same amount of co-terminating agent was added at the end of the reaction. the reaction or if an excess of monofunctional acid was used in the polymerization. Because a small amount of crowning agent is used, the process of the present invention eliminates the need to recover an unreacted monofunctional acid from the recovery system of polymers or solvents. The poii (ethers of hydroxyesters) or poly (hydroxyesters) prepared by the process of the present invention have repeating units represented by the formula: C-RL-CO.-R ^ O-R4-O-R: 7- wherein R1 is a divalent organic moiety which is primarily a hydrocarbon; R3 is: OH CH2OH I I - CH2-C-CH2- and - C- CH2 -; I I and R4 is: wherein R2 and R6 are independently divalent organic portions which are primarily hydrocarbons; R5 is hydrogen or alkyl and n is from 0 to 100. In the preferred polymers, R1, R2 and R6 are independently alkylene, cycloalkylene, alkylenearylene, alkyleneoxyalkylene, poly (alkyleneneoxyalkylene), alkyleneamide-alkylene, poly (alkyleneamide-alkyl) ), alkylenethioalkylene, poly (alkylenethioalkylene), alkylene sulfonylalkylene, poly (alkylene-sulphonylalkyl), arylene, dialkylenearylene, diacenediacetone, diarylene sulfone, diarylene oxide, diakylene diarylene, diarylene sulphide, or a combination of these portions, optionally substituted with at least one hydroxyl group. In the most preferred polymers, R is methylene, ethylene, propylene, butifen, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, dodecamethylene, 1,4-cyclohexylene, 1,3-cyclohexylene or 1,2-cyclohexylene, optionally substituted with at least one hydroxyl group; and R 2 and R 6 are independently methylene, ethylene, propylene, butylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, dodecamethylene, 1,4-cyclohexylene, 1,3-cyclohexylene or 1,2-cyclohexylene, optionally substituted with at least one hydroxy group. More preferably, R1 and R6 are represented by the formula: and R2 is represented by the formula: wherein R7 is independently hydrogen or methyl; x and y are independently from 0 to 100. In the most preferred polymers, R1 and R6 are independently m-phenylene, p-phenylene or 2,6-naphthalene; R2 is independently m-phenylene, p-phenylene, naphthalene, diphenylene-isopropyl-deen, sulfonyldiphenylene, carbonyldiphenylene, oxydipheniene or 9,9-fluorenodiphenylene; R5 is hydrogen; R7 is independently hydrogen or methyl. Generally, the process of the present invention comprises reacting dicarboxylic acids and diepoxides in a given solvent in the presence of an end capping agent and a catalyst under conditions sufficient to form the hydroxy functionalized polyethers or polyesters. The terminating agent is added at the beginning of the reaction together with the other starting materials. Dicarboxylic acids that can be used in the practice of the present invention include succinic acid, adipic acid, suberic acid, azaleic acid, sebacic acid, 1,1-decanedicarboxylic acid, 1,2-dodecanedicarboxylic acid, 1,3- cyclohexanedicarboxylic acid, tartaric acid, terephthalic acid and isophthalic acid. Diepoxides that can be employed in the practice of the present invention include diglycidyl ethers or dihydric phenols, such as those described in U.S. Pat. 5,246,751; 5,115,075; 5,089,588; 4,480,082 and 4,438,254, or the diglycidyl ethers of dicarboxylic acids such as those described in the U.S. Pat. 5,171,820. Other suitable diepoxides include epoxy resins based on a, ra-digiicidyloxy-p-propylidene-bisphenol (commercially known as epoxy resins of the 300 and 600 DER ™ series), phenoxy resins based on a.ts-digiicidyloxy tetrabroisopropylidene-bisphenol, such as Quatrex ™ 6410, both a product of The Dow Chemical Company. Preferred diepoxides are epoxy resins having an epoxy equivalent weight of from 100 to 4000. The most preferred diepoxides are the diglycidyl ethers of bisphenol A; 4,4'-sulfonyl diphenol; 4,4-oxydiphenol; 4,4'-dihydroxybenzophenone; resorcinol; hydroquinone; 9,9'-bis (4-hydroxyphenyl) fluorene; 4,4'-dihydroxybiphenyl or 4,4'-dihydroxy-a-methyl-ethylbenzene and the diglycidyl esters of the aforementioned dicarboxylic acids. Endcapping agents that can be employed in the present invention include monofunctional nucleophiles capable of reacting with an epoxide group and include monofunctional carboxylic acids, monohydric phenols, secondary amines and thiols. Preferred end-capping agents are monofunctional carboxylic acids. The most preferred co-terminating agents are benzoic acid, acetic acid and propionic acid, with propionic acid being more preferred. The process of the present invention requires only a fraction of the amount of co-terminating agents employed in the known processes previously described. In general, the process of the present invention requires only 0.25 to 3.0 mole percent of an end capping agent (based on the diglycidyl ether or diglycidyl ester) in the polymerization mixture to effectively control the molecular weight buildup that could somehow be presented during an extended heating phase of the commercial production of the polymers.

In general, the reaction of the dicarboxylic acid and diepoxide requires a catalyst or any material capable of catalyzing the reaction. While any material capable of catalyzing the reaction can be used, the preferred catalysts are the onium catalysts. The preferred onium catalysts include the catalysts of phosphonium or ammonium salts. The most preferred onium catalysts include tetrabutylammonium bromide, ethyltriphenylphosphonium iodide, tetraphenylphosphonium bromide and tetrakis (n-butyl) ammonium bromide and the corresponding chloride, iodide, bromide, acetate, formate, phosphate, borate, trifluoroacetate, oxalate and bicarbonate tetrakis (n-butyI) ammonium bromide being the most preferred. The conditions to which the polymerization reaction is most advantageously carried out depend on a variety of factors, including the specific reagents, solvent and catalyst used, if any. In general, the reaction is carried out under an atmosphere without oxidation such as a blanket of nitrogen or other inert gases. The reaction can be carried out in a pure form (without solvent or other diluents). However, in order to ensure homogeneous reaction mixtures and to moderate the exothermic reactions at said temperatures, it is often convenient to use inert organic solvents for the reagents. The time and temperature employed will very advantageously vary depending on the specific monomers employed, particularly their reactivity, the specific oligomer and the organic liquid. In general, the reaction temperature for forming the polyesters or polyethers is 80 ° C to 220 ° C and more preferably 120 ° C to 140 ° C and for a time of 30 minutes to 24 hours, more preferably 3 hours to 24 hours and even more preferably from 4 hours to 20 hours.

The concentrations at which the monomers are used most advantageously in the organic liquid reaction medium depend on a variety of factors including the specific monomers and organic liquid employed and the polymer being prepared. In general, the monomers are employed in a stoichiometric ratio of diacid to epoxy from 0.8: 1.0 to 1.2: 1.0. Any inert organic solvent which can dissolve the monomers to the appropriate degree and can be heated to the appropriate polymerization temperature, either at atmospheric, subatmospheric or superatmospheric pressure and which does not interfere with the reaction of a portion of the carboxylic acid with a portion of epoxide. Examples of suitable solvents include cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, cyclohexylpyrrolidinone; and hydroxy ethers or ethers such as dioxane, diglyme, tripolyme, diethyl ethyl ether, diethylene glycol methyl ether, propylene glycol methyl ether acetate, propylene glycol methyl ether and tripropylene glycol methyl ether; toluene, mesitylene, xylene, benzene, dipropylene glycol monomethyl ether acetate, halogenated solvents such as dichlorobenzene; propylene carbonate, naphthalene, diphenyl ether, butyrolactone, dimethylacetamide, dimethylformamide, esters such as ethyl acetate or butyl acetate and mixtures thereof. The preferred solvents are diglyme, dioxane and propylene glycol methyl ether acetate.

During polymer synthesis, the polymers were recovered from the reaction mixture by conventional methods. For example, the reaction mixture containing the polymer as a precipitate can be filtered to remove the solid polymer. The solid monomer can then be rinsed with water, methanol and ether or other solvents that are non-solvent for the polymer, but are good solvents for impurities. The polymer can also be isolated by pouring the reaction mixture in a non-solvent for the polymer and recovering the precipitated product. Additionally, the product polymer can be isolated by solvent removal by vacuum distillation, evaporation of cleaned film or devolatilization extrusion. The following examples are for illustrative purposes only and are not intended to limit the scope of this invention. Unless otherwise indicated, all parts and percentages are by weight. Example 1 A 1 liter reaction vessel equipped with a mechanical stirrer (driven by air), condenser (with chilled water) and nitrogen inlet (to maintain a nitrogen pad) was used for this reaction. The temperature was controlled using a heating mantle and a Thermal-watch® temperature controller (a glass thermometer was used). The reagent, D.E.R. 331 ™ (186.1 g), adipic acid (73.07 g), propionic acid (0.37 g), tetrabutyl ammonium bromide (TBA Br) (1.66 g) and propylene glycol methyl ether acetate (261 g) were weighed directly into the vessel of reaction. The total solids were 50 percent. The reaction mixture was stirred and heated to 120 ° C. An aliquot was taken every hour (for the first 7 hours) and the GPC and inherent viscosity measurements were performed. The results are shown in Table I. The reaction mixture was diluted with THF to about 20 percent solids and the polymer was precipitated in water. The reaction mixture was poured into a high speed mixer containing cold hexane in order to precipitate the PHEE polymer. This needs to be done several times in order to remove the propylene glycol methyl ether acetate from the polymer. The product was dried in a vacuum oven at 35 ° C for 24 hours.

Comparative Example A The procedure described in Example 1 was repeated, except that the propionic acid was added at the end instead of at the beginning of the polymerization, the results are shown in Table I.

Table Aggregate Propionic Acid Pro Pionic Acid Added at the beginning of the Reaction Ending at the End of the Reaction Time (hr.) Mps1 Mp2 Mn3 mps1 Mp2 Mn3 0 710 255 429 471 255 322 1 7977 7577 3395 2292 1651 1066 2 22506 21722 7049 9881 9324 3745 3 32114 27522 8513 49392 26001 6609 4 35354 28150 8338 67818 31329 7820 5 36513 28553 8109 74546 30299 7725 6 37192 28553 8645 82245 31681 8372 7 37823 28756 8145 91814 31069 7710 MpS1 = weight average molecular weight Mp2 = peak molecular weight Mn3 = average molecular weight in number. The terms "weight average molecular weight" and "number average molecular weight" are well known in the art and are described, for example, in Encyclopedia of Polymer Science and Engineering. John Wiley and Sons, Second Edition, Vol. 10, p. 1-11. The term "peak molecular weight" refers to the weight-average molecular weight of the polymer at the bottom of the reaction. The data in the above table shows that the addition of propionic acid at the end of the ro reaction helps control the molecular weight since propionic acid is added at the beginning of the reaction. The data also shows that the peak average molecular weight and the number average molecular weight of the polymer reach a maximum value after a few hours in the reaction and remain constant while the weight average molecular weight maintains the increase as a function of time under a given set of conditions. Example 2 The procedure described in Example 1 is repeated, except that benzoic acid was used in place of propionic acid as the terminating co-terminating agent. The results are shown in Table II. Table II Time (hours) Mw Mn Mf 0 255 306 419 1 5369 2138 5678 2 14868 5897 19037 3 27184 6761 32436 4 27796 6855 34624 5 29062 7289 39705 6 29062 7195 40066 7 28776 7239 41514 8 28896 7026 42130 The polymers prepared by process of the present invention are useful for preparing containers and barrier film and as molding, extrusion and casting resins, for manufacturing molded, extruded or foamed articles, containers, films, film laminates or coatings using conventional manufacturing techniques such as extrusion techniques with compression molding and injection molding, blow molding and similar manufacturing commonly used to produce said articles. Examples of such articles include films, foams, sheets, pipes, rods, bags and boxes.

Claims (28)

1. CLAIMS 1. A process for preparing poly (ester ethers) or hydroxy-functionalized polyesters, thermoplastics, comprising contacting a dicarboxylic acid or a mixture of dicarboxylic acids with a diepoxide in the presence of a terminating agent, a catalyst and a solvent under conditions sufficient to form the hydroxy-functionalized polyesters; where the end-capped agent is added at the start of the reaction or before, or at the point where the product reaches the maximum peak molecular weight, or the number average, number-average molecular weight 2. The process of claim 1, wherein the dicarboxylic acid is succinic acid, adipic acid, suberic acid, azaleic acid, sebacic acid, 1,1-O-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tartaric acid, terephthalic acid, acid isoittal or combinations thereof. 3. The process of claim 1, wherein the diepoxide is a diglycidyl ether of a dihydric phenol. 4. The process of claim 3, wherein the diepoxide is the diglycidyl ether of bisphenol A; 4,4'-sulfonyl diphenol; 4,4-oxydiphenol; 4,4'-dihydroxybenzophenone? A; resorcinol; hydroquinone; 9,9-bis (4-hydroxyphenyl) fluorene; 4,4'-düh i croxi biphenyl, 4,4'-dihydroxy-α-methyl-ethylbenzene or combinations thereof. 5. The process of claim 1, wherein the diepoxide is a diglycidyl ester of a dicarboxylic acid. 6. The process of claim 5, wherein the diglycidyl ester is a diglycidyl ester of succinic acid; adipic acid; suberic acid; azaleic acid; sebacic acid; 1,10-decanedicarboxylic acid, 1,2-dodecanedicarboxylic acid; 1,4-cyclohexanedicarboxylic acid; tartaric acid; terephthalic acid; isophthalic acid or combinations thereof The process of claim 1, wherein the diglycidyl ether or diglycidyl ester has an epoxy equivalent weight of from 100 to 4,000. The process of claim 1, wherein the catalyst is an onium catalyst. 9. The process of claim 8, wherein the onium catalyst is a phosphonium salt catalyst or ammonium salt. The process of claim 9, wherein the onium catalyst is an ethyltriphenylphosphonium iodide, tetraphenylphosphonium bromide or tetrakis (n-butyl) bromide, chloride, iodide, acetate, formate, phosphate, borate, trifluoroacetate, oxalate or bicarbonate. ammonium. The process of claim 10, wherein the onium catalyst is tetrakis (n-butyl) ammonium bromide. The process of claim 1, wherein the catalyst is present in an amount of 0.001 to 10 mole percent, based on the number of moles of dicarboxylic acid in the reaction mixture. 13. The process of claim 1, wherein the terminating agent is a monofunctional carboxylic acid or a monohydric phenol. The process of claim 13, wherein the terminating agent is a monofunctional carboxylic acid. 15. The process of claim 14, wherein the monofunctional carboxylic acid is propionic acid, acetic acid or benzoic acid. 16. The process of claim 15, wherein the monofunctional carboxylic acid is propionic acid. The process of claim 1, wherein the terminating agent is added at the beginning of the reaction together with the other starting materials. 18. The process of claim 1, wherein the end capping agent is added to the reaction before the point at which the product reaches the maximum peak or number average molecular weight. The process of claim 1, wherein the terminating agent is added to the reaction in an amount of 0.25 to 3.0 mole percent based on the diglycidyl ether or the diglycidyl ester present in the polymerization mixture. . The process of claim 1, wherein the terminating agent is added to the reaction at the point at which the product reaches its maximum peak molecular weight or number average molecular weight. 21. The process of claim 1, wherein the solvent is an ether or polyether or a substituted ether or polyether, the substituent being a compound that does not interfere with the reaction of a carboxylic acid moiety with an epoxide moiety. 22. The process of claim 1 ,. where the solvent is an ester. 23. The process of claim 18, wherein the solvent is diglyme, dioxane or propylene glycol methyl ether acetate. 24. The process of claim 1, comprising mixing a dicarboxylic acid, an end capping agent, a catalyst, a diglycidyl ether or a diglycidyl ester and a solvent at a temperature sufficient to dissolve all reagents and for a time sufficient to produce a poly (hydroxy ester) or poly (hydroxy ester). 25. The process of claim 23, wherein the reaction temperature is from 100 ° C to 220 ° C and the reaction time is from 4 to 24 hours. 26. The process of claim 1, further comprising isolating from po! I (hydroxy ester ester) or poly (hydroxy ester) by precipitating it from the solvent in which the polymer is insoluble. 27. The process of claim 1, further comprising isolating the poly (hydroxy ester ester) or poly (hydroxy ester) polymer by removing the solvent by vacuum distillation, evaporation of cleaned film and / or devolatilization extrusion and, optionally, pellet the polymer. 28. A poly (hydroxy ester) or p or I i (h id rox i ester) prepared by the process of claim 1. RES UMEN A process for preparing a polyester functionalized with thermoplastic hydroxy, comprising contacting a dicarboxylic acid or a mixture of dicarboxylic acids with a diepoxide in a given solvent in the presence of a co-terminating agent and a catalyst under sufficient conditions to form polyesters or polyethers functionalized with hydroxy.