DE1445311B2 - PROCESS FOR THE PROCESSING OF WASTE FROM DIFFICULT, HIGH MOLECULAR TEREPHTAL ACID DIOLESTERS - Google Patents

Description

When processing sparingly soluble, high molecular weight Terephthalic acid diol esters into foils. Fibers or plastics often result in larger ones Amounts of waste for which there was previously no possibility of economic recovery.

The invention now relates to a method for processing sparingly soluble, high molecular weight wastes Terephthalic acid diol ester, which is characterized in that one either

a) with olefinically unsaturated dicarboxylic acids, the anhydrides or esters of which are transesterified with heating and then the reaction products with polyhydric, especially dihydric alcohols further esterified or

b) - optionally after a reaction with adipic acid - with polyhydric alcohols transesterified and then the reaction products with olefinically unsaturated dicarboxylic acids or their derivatives further esterified, with at least trihydric alcohols also used can be used together with such amounts of monohydric alcohols that the order two reduced free hydroxyl groups of the at least trihydric alcohol are equivalent are,

and optionally copolymerizing the mixed polyesters thus obtained with polymerizable monomers.

The unsaturated dicarboxylic acids can also be used together with saturated dicarboxylic acids, their anhydrides or esters can be used. It is preferred to use polyvalent, especially divalent Alcohols with boiling points of more than 200 ° C. Dissolve the high molecular weight terephthalic acid diol esters develop very quickly in the dicarboxylic acids or their anhydrides at temperatures above 200 ° C, slower in the oligomers or the mono- or diesters of the dicarboxylic acids or according to the procedure b) polyhydric alcohols initially used. The properties of the polyester resins obtained can be achieved by varying the ratio of terephthalic acid diol ester to dicarboxylic acid or terephthalic acid diol ester to polyhydric alcohol as well as by the type of dicarboxylic acid or the polyhydric Alcohol change largely.

The reactions according to a) and b) can, for. B. can also be carried out in autoclaves under pressure.

Suitable olefinically unsaturated dicarboxylic acids are, for. B. maleic acid, fumaric acid, itaconic acid, Citraconic acid or mesaconic acid.

Suitable saturated dicarboxylic acids are e.g. B. Amber, Glutar, Adipine, Pimeline, Azelaine, Sebacic acid, also ortho- or isophthalic acid or hexahydrogenation products of these acids or the Terephthalic acid, endomethylene hexahydrophthalic acid, the various tri- or tetrachlorophthalic acids or to understand hexachloroendomethylene tetrahydrophthalic acid. When using halogenated acids they can be used in such an amount that the resin is incombustible. Also the Oligomeric or mono- or diesters of these dicarboxylic acids can be used.

Particularly suitable polyhydric alcohols are dihydric alcohols, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propanediol, the various butane, pentane or hexanediols, such as 1,4-butanediol or 2,2-dimethylpropanediol 1,3,2-ethyl-2-butyl-propanediol-1,3, butenediol, hydrogenated bisphenols; partially etherified, at least trihydric alcohols, which are preferably etherified to such an extent that they still contain two free hydroxyl groups, e.g. B. partially etherified glycerine. Trimethylolpropane, trimethylolethane, hexanetriol or pentaerythritol; Dimethylolbenzene, -toluene, -xylene; Addition products of alkylene oxides, such as ethylene, propylene or butylene oxides, with dihydric alcohols, e.g. B. the aforementioned, or divalent phenols such as resorcinol, hydroquinone, 4,4'-dihydroxydiphenylmethane, ethane, propane, or homologues. If appropriate, higher-valent alcohols can also be used instead of the dihydric alcohols or together with them, e.g. B. glycerol, trimethylolethane, trimethylolpropane, hexanetriol or pentaerythritol. The properties of the reaction products can still be modified to a large extent by such higher-value alcohols. Is expedient to employ these high-order alcohols, however, only used in such quantities that the proportion of the "excess" hydroxyl groups (that is, the number of reduced two free hydroxyl groups of the at least trivalent alcohol) is not higher than 20 ° / _0, preferably not higher than 10 ° / ₀ . Such at least trihydric alcohols can also be used together with such amounts of monohydric alcohols which are equivalent to the "excess" hydroxyl groups (in the sense of the previous definition).

According to the invention so clear, break-resistant polyester resins which z. B. are useful as valuable paint raw materials or as moldings with good mechanical properties.
The following are, for example, suitable for the copolymerization: vinyl toluene. Vinylpyrrolidone, styrene, α-methylstyrene, chlorostyrene, divinylbenzene, vinyl acetate, vinyl propionate, allyl acetate, allyl propionate, diallyl maleate, fumarate, succinate, adipate, acelate, sebacate or phthalate, triallyl phosphate, methyl,

Ethyl, propyl, butyl (primary, secondary, tertiary or iso), amyl, hexyl or allyl acrylate or methacrylate, diallyl itaconate, acrylonitrile or a mixture of such monomers. The preferred monomers are therefore those compounds in which the --CH = CH ₂ group is bonded to a negative radical, such as to a benzene nucleus, to the ester group or to the nitrile group. Those monomers which contain no conjugated double bonds and which are normally liquid are largely preferred.

The amount of olefinic monomers is often between 30 and 50 percent by weight of the ester component, but much larger, z. B. 80 ° / ₀ , or smaller amounts, e.g. B. 10% can be used.

Suitable catalysts are, for. B. benzoyl peroxide, 2,3-dichlorobenzoyl peroxide, acetyl peroxide, tert-butyl peroxide or hydroperoxide, succinyl peroxide, lauroyl peroxide, cyclohexyl hydroperoxide, cyclohexanone peroxide, Methyl ethyl ketone peroxide, methyl

isobutyl ketone peroxide, dibenzaldiperoxide, cumene hydroperoxide, 2,2-bis (tertiary butylperoxy) butane, tert-butyl peracetate, tert-butyl perbenzoate, di-tert-butyl dipersuccinate, -diperphthalate, -diperterephthalate or Azoisobutyronitrile.

According to German Auslegeschrift 1 017 789, terephthalic acid alkyl ester, i.e. an ester with a monovalent one Alcohols, are first transesterified with alkylene glycols and the transesterification product

finally further esterified with an unsaturated acid or its anhydride. The first made However, terephthalic acid glycol ester is not compatible with the high molecular weight starting materials comparable to the present application.

According to the German Auslegeschrift 1112 292 can Terephthalic acid glycol ester waste from film production in monomeric terephthalic acid ethylene glycol ester can be dissolved at temperatures above 225 ° C. This publication contains however, there is no information that such transesterification products continue with polyhydric alcohols to be converted to polyester resins, it should rather be a high molecular weight polyethylene glycol terephthalate that can be used to make films or fibers.

The French patent specification 1,222,989 describes the conversion of waste from polyethylene glycol terephthalate with ethylene glycol, optionally in the presence of dialkyl esters of terephthalic acid. This document does not contain any information that the waste is in esters of an unsaturated dicarboxylic acid should be solved. In addition, high molecular weight polyethylene glycol terephthalate should be made from the reaction products again be won.

The Belgian patent 574 385 describes a process for the production of mixed polyesters without that it discloses the implementation of terephthalic acid esters. It starts with low molecular weight starting materials, such as dicarboxylic acids or acid chlorides with an excess of glycols. In the Polyesters obtained in the first stage should be of low molecular weight. In the second stage, they are above 200 ° C melting polyesters from aromatic diols and acid chlorides reacted, with the acid component this polyester can also be terephthalic acid.

According to Belgian patent 579 635 polyesters are made from a linear polyester and a Monoglycol, a bisglycol or polyesters made from a glycol and an unsaturated dicarboxylic acid manufactured. The possibility of using high-molecular terephthalate waste as starting materials is however not disclosed. According to this process, the two starting polyesters are to be copolymerized to form products in which the two polyesters are additively bound to one another.

In contrast, the present invention enables the processing of high molecular weight wastes of terephthalic acid diol esters, valuable products with advantageous properties being obtained.

Example 1

300 g of a high molecular weight terephthalic acid diol ester, obtained as waste during processing into foils in the form of chips, are heated to temperatures above 200 ° C with 294 g of maleic anhydride under a protective gas atmosphere (nitrogen) until a clear, homogeneous, low-viscosity solution is formed which takes about 1 hour. 228 g of 1,2-propanediol are allowed to run in over the course of 3 hours, slowly increasing the temperature by a total of 20.degree. Esterification is carried out at 220 ^° C. until the acid number is below 50, then the reaction product is kept in vacuo at 20 to 30 torr for a further hour. A clear, break-proof polyester is obtained on cooling.

Dissolve 25 g of this polyester in 65 g of monoethyl ether of ethylene glycol and 10 g Essigsäureester of Monoäthyläthers of ethylene glycol and burns, the solution thus obtained is applied to plate for 10 minutes at 220 ⁰ C, paint films give excellent adhesion and good chemical resistance.

Solving 70 parts of this resin in 30 parts of styrene and hardened after the addition of 2 parts Benzoylperoxydpaste (50 ° / ₀ solution in dibutyl phthalate) at 80 ° C, so to obtain moldings with good mechanical properties. - Plotting 50 parts of the styrenic polyester resin solution, catalyzed with 1.5 parts Benzoylperoxydpaste and treated with 1 to 2 ° / ₀ of a conventional tertiary amine as an accelerator, a glass fiber mat of 35 g weight, are obtained glass fiber-reinforced body with very good crush strength and particularly high tensile strength.

Eg 1 2

175 g of high molecular terephthalic acid diol ester are dissolved in 196 g of maleic anhydride and 148 g of o-phthalic anhydride with heating to over 200 ° C. as in Example 1. Then allowed to within 3 hours and under a slow temperature increase to 220 ⁰ C 228 g of 1,2-propanediol are added dropwise, esterified until the acid number is below 50, and then stops with stirring for one hour under vacuum of 20 to 30 torr.

The solution solidifies on cooling to form a clear, break-proof polyester, which is used according to Example 1 can be.

Example 3

300 g of high molecular weight terephthalic acid diol ester are heated with 684 g of maleic acid dibutyl ester to over 220 ° C. with stirring and under protective gas until a clear, homogeneous, low-viscosity solution has formed. Is then added with stirring in small portions 312 g of 2,2-dimethyl-l, 3 to and so long esterified under temperature increase of 3O ⁰ C to until a viscosity of 120 cP 1: 1 is reached in the monoethyl ether of ethylene glycol. It is then evacuated at 20 to 30 Torr for 1 hour. A clear, unbreakable polyester is obtained.

Example 4

200 g of high molecular weight terephthalic acid ester according to the preceding examples are ^{heated to over 200 °} C. under protective gas with 312 g of 2,2-dimethylpropanediol-1,3 until a clear, homogeneous, low-viscosity solution has formed. 116 g of fumaric acid and 296 g of o-phthalic anhydride are then introduced in portions and esterification is continued with a slow increase in temperature until the acid number is below 50. It is then kept under vacuum (20 to 30 Torr) for a further hour and, after cooling, a clear, break-resistant polyester is obtained.

Example 5

300 g of high molecular weight terephthalic acid ester, 312 g of 2,2-dimethylpropanediol-1,374 g of o-phthalic anhydride and 247 g of maleic anhydride are, as described in Example 4, reacted. You get one clear, firm polyester.

Example 6

300 g of high molecular weight terephthalic acid ester, 270 g of 1,3-butanediol, 74 g of o-phthalic anhydride and 247 g

Maleic anhydride are reacted according to Example 4. A clear, break-proof polyester is obtained.

B e i s ρ i e 1 7

^{300 g of high molecular weight terephthalic acid diol ester are heated to over 200 °} C. with 312 g of 2,2-dimethylpropanediol-1,3 with stirring and under protective gas until a clear, homogeneous, low-viscosity solution has formed. Then 742 g of 3,6-endo-dichloromethylene-tetrachloro-tetrahydrophthalic anhydride are added and esterified to an acid number <50, then 98 g of maleic anhydride are added, the mixture is stirred until the acid number is <50 and the mixture is evacuated to 20 to 30 torr for 1 hour. A clear, break-resistant resin is obtained which, dissolved in 70:30 in monostyrene, gives test specimens with good heat resistance which are cured at 80 ° C. with 2% benzoyl peroxide paste.

Example 8

292 g of adipic acid and 300 g of high molecular weight terephthalic acid ethylene glycol ester are heated to over 220 ° C. with stirring and under protective gas, and 312 g of 2,2-dimethylpropanediol-1,3 are then added in portions. It is esterified to an acid number below 10. This product can be further esterified with 98 g maleic anhydride, e.g. B. until the acid number is below 50. The resin thus obtained is evacuated for 1 hour at 20 to 30 Torr, then dissolved in a weight ratio of 70:30 in styrene and 2 ° / o Benzoylperoxydpaste (50 ° / ₀ solution in dimethyl phthalate) at 80 ° C to give moldings with good impact strength and flexural strength hardened.

Claims (2)

'Patent claims: 1. Process for processing waste of sparingly soluble, high molecular weight terephthalic acid diol esters, characterized in that one either a) with olefinically unsaturated dicarboxylic acids, their anhydrides or esters with heating transesterified and then the reaction products with polyvalent, especially divalent Further esterified alcohols or b) - optionally after a reaction with adipic acid - with polyhydric alcohols transesterified and then the reaction products with olefinically unsaturated dicarboxylic acids or their derivatives further esterified, at least trihydric alcohols used also together with such amounts monohydric alcohols can be used, the reduced by two free Hydroxyl groups of the at least trihydric alcohol are equivalent, and optionally copolymerizing the mixed polyesters thus obtained with polymerizable monomers. 2. The method according to claim 1, characterized in that the unsaturated dicarboxylic acids used together with saturated dicarboxylic acids, their anhydrides or esters.