WO1993005106A1

WO1993005106A1 - Process for producing dispersed liquids containing hydroxy and/or amino-functional compounds and their use

Info

Publication number: WO1993005106A1
Application number: PCT/DE1992/000702
Authority: WO
Inventors: Hannelore Baumgarten; Alfred Mayer; Uwe Frank; Manfred Schmiedel
Original assignee: Pebra Gmbh Paul Braun
Priority date: 1991-08-28
Filing date: 1992-08-21
Publication date: 1993-03-18
Also published as: JPH06510068A; CA2116434A1; EP0600994A1; DE4128588A1

Abstract

The invention relates to dispersed liquids containing hydroxy and/or amino-functional compounds by causing polyurethane, polyurethane/polyurea and polyurea waste made by the PUR-RIM and/or RRIM process to react with at least one diamine compound. The dispersed liquids thus made are suitable for the production of polyurethanes, polyurethane ureas or polyureas.

Description

Process for the production of disperse liquids which contain hydroxy- and / or amino-functional compounds and their use.

The invention relates to a process for the production of disperse liquids which contain hydroxy- and / or amino-functional compounds from polyurethane, polyurethane / polyurea or polyurea wastes which are used in PUR-RIM and / or - RRIM- Process (Polyurethane (Reinforced) Reaction Injection Molding process) were produced.

It is known that by alcoholic degradation, polyurethanes can be broken down again into more or less liquid, viscous, hydroxy functional components which are capable of reacting with tsocyanates. Obtaining these reaction components therefore represents a process for chemical and chemical recycling of PUR wastes.

Various alcoholysis processes are described in the following publications

DE-PS 25 15 863, DE-PS 27 38 572, DE-PS 29 51 617, DE-PS 32 32 461, DE-PS 37 02 495 or DE-PS 40 24 601 described.

In almost all of the processes described, chemical degradation is carried out using diols, with hydroxy-functional compounds being formed as the reaction product. The reaction conditions for the cleavages are usually drastic. At temperatures around 200 ° C the reaction times are 1-2 hours. In this case, side reactions occur which are undesirable for toxicological, qualitative and economic reasons.

Thus, in not negligible amounts, for example, by cleavage, the isocyanates used, for example methylene diphenyl diisocyanate (MDI) and tolylene diisocyanate (TDI), corresponding amines, methylenediphenyldiamine (MDA) and toluenediamine (TDA) _r which are classified as carcinogenic. In addition, there are side reactions which take place with evolution of CO2 and cyclization reactions of the glycols with the formation of, for example, dioxane derivatives.

The side reactions, which lead to inconsistent compositions, are also disadvantageous for the following reasons: The so-called PUR-RRIM parts are a special application of the polyurethanes, predominantly in the motor vehicle sector. These polyurethane / polyurea RRIM systems consist of a Polyether polyol, an aromatic isocyanate and a diamine crosslinker. The isocyanate and the diamine crosslinker react with one another to form urea structures. Several successive sequences of isocyanate-amine units result in a so-called hard segment chain. The hard segment chains are connected to one another via hydrogen bonds and, as hard segment domains that separate in the soft segment phase (polyether polyol), represent the crosslinking points of the material. The structure of these hard segment domains largely determine the properties of the polyurethane / polyurea systems . It is therefore important to have a composition of the recovered starting components which is as uniform as possible when reprocessing the polyurethane / polyurea RRIM material.

Furthermore, the excess glycols and by-products which are still present in the reaction mixture during alcoholysis have a disadvantageous effect on the hard segment structures and the properties of the polyurethane / polyurea material.

The invention is therefore based on the object of a process for the degradation of polyurethane, polyurethane / polyurea, poly to provide urea waste that avoids the disadvantages of the alcoholysis process.

This object is achieved according to the invention by a process for the production of disperse liquids which contain hydroxy- and / or amino-functional compounds, by reaction of polyurethane, polyurethane / polyurea, polyurea wastes which are in the PUR-RIM and / or -RRIM -Procedures were made with at least one diamine compound.

So far it has not been possible to obtain hydroxy- and / or amino-functional compounds from polyurethane, polyurethane / polyurea or polyurea wastes which have been produced in the PUR-RIM and / or -RRIM process by inolytic degradation can be reused for the production of the polymers. In particular, no technically feasible method is known up to now to break down RRIM materials into reusable products by aminolysis.

A process is preferred in which aromatic diamines as amine compounds in a weight ratio of polymer wastes to diamine of 1: 0.1 to 1: 2, in particular of 1: 0.15 to 1: 0 _. 4 at a temperature of 140 to 180 ° C, in particular 160 to 180 ° C, and a reaction time of 30 to 120 minutes, in particular 45 to 120 minutes, optionally in the presence of at least one catalyst.

The polyether polyol which is the basis of the polyurethane / polyurea waste or which is used to blend the recycling product for use in the RRTM process is advantageously chosen as the reaction medium.

In a particularly advantageous manner, a is used as the solvent Hydroxyl-containing polyether polyol with a molecular weight of 200 to 12000 in a weight ratio of polymer waste to polyether polyol of 1: 1 to 1:10, in particular from 1: 1 to 1: 5, is used.

It is advantageously used as a slide in a compound of the following general formula

H ^ N - R - NH ^ used, where R can be an aromatic ring optionally substituted with one or more different or the same alkyl radicals.

Preferred alkyl radicals on the aromatic ring are methyl, ethyl and propyl radicals. According to a particularly preferred embodiment of the invention, the aminolysis reagent consists of the chain extender on which the polyurethane, polyurethane / polyurea, polyurea formation reaction is based. Detda (diethyltoluenediamine) can be used here. The excess of the diamine therefore has no adverse effect on the recycling of the aminolysis product as the starting polyol for a polyurethane / polyurea product.

Organometallic compounds can be used as catalysts. Dibutyltin dilaurate is preferred.

The products produced by the process according to the invention only have carcinogenic methylene diphenyldiairtine or toluenediamine in minimal or undetectable amounts compared to the product pn produced by alkyolysis.

Furthermore, the process according to the invention requires shorter reaction times and lower temperatures, which is to be regarded as an essential economic advantage. In addition, the present process leads to fewer side reactions, which is reflected in a higher yield and in a better quality product.

During alcoholysis, some of the urea is cleaved, and the diol used, together with the isocyanate, in turn forms a urethane which can be cleaved. The same does not occur in the method according to the invention.

The diamine used does not interfere with the reprocessing of the aminolysis products, since it is an ingredient already present in the polymer. In contrast, the diol used in the alcoholysis leads to reaction groups which are new polymer and can therefore have a disadvantageous effect on the product properties.

For reasons of recyclability of the products obtained according to the invention, it is therefore advantageous to start from polymer wastes which are composed of polyether polyol, aromatic isocyanates and diethyltoluenediamine. RIM and / or RRIM production wastes are generally suitable, even if they are mixed with glass fibers or still contain paint components. The polymer wastes can either be mixed in the cold with the polyether / slide in / optionally a catalyst mixture and brought to the appropriate reaction temperature, or can be metered directly into the previously heated polyether / diamine / catalyst mixture. In any case, thorough mixing must be ensured, and the reaction can be carried out in a continuous or discontinuous manner.

During the reaction, the polyurethane / polyurea systems usually already liquefy when the urethane bonds are cleaved. The urea resin segments remain in the system as a reactive solid and there an OH-terminated polyether is formed.

The disperse liquids produced according to the invention are particularly well suited for the production of polyurethanes, polyurethaneureas or ureas, in particular by the RIM and / or RRIM process. The following examples illustrate the invention.

example 1

A reaction vessel equipped with a reflux condenser, N-w feed and with a stirrer was mixed with a mixture of 91 g of polyether polyol (MW 4800)

9g detda (diethyltoluenediamine), 25g finely divided polyurethane / polyurea waste, 80mg DBTDL (dibutyltin dilaurate)

charged and heated to 170 ° C. with stirring in an oil bath. After the end temperature had been reached, the reaction mixture was kept at this temperature for 45 minutes with constant stirring. The PU / PH liquid mixture changed its consistency from a greenish viscous to a light brown viscous mass. The result was a practically homogeneous, viscous, disperse liquid at room temperature. No sedimentation of solid particles was observed. No MDA formation took place after the GC spectrum.

The result was a viscosity at 25 ° C. of 3.84 • lo as, at 40 ° C. of 1.44-10 ³ mPas and an NH, number of 44.43.

The insoluble content in DMSO was about 20% of the PTJ / PH material used (corresponds to about 20% glass fiber)

Spare sheet Example 2 (comparison)

The procedure was as in Example 1, but with 6 g of ethylene glycol (EG) instead of the diamine and 97 g of polyether. 3 phases formed at room temperature, the product settling out, which is to be regarded as disadvantageous.

The result was a viscosity at 25 ° C of 3.50 • 10mPas, at 40 ° C of 1.31 • lo as and an NH ^ number of 3.66.

The insoluble fraction in DMSO was approximately 33% of the PU / PH material used (corresponds to approximately 20% glass fiber and approximately 13% unreacted material).

Example 3

The procedure was as in Example 1, but with 50 g of polyurethane / polyurea waste and 160 mg of DBTDL. The highly viscous mass became a practically homogeneous brown mass during the reaction. At room temperature, a practically homogeneous, viscous, disperse liquid resulted. No sedimentation of solid particles was observed. No MDA formation occurred after the GC spectrum.

The result was a viscosity at 25 ° C. of 14.0 lOmPas, at 40 ° C. of 5.68 • lo as and an NH ₂ number of 38.15.

The insoluble content in DMSO was about 20% of the PU / PH material used (corresponds to about 20% glass fiber).

Dilution of the product with half the amount by weight of the polyol used resulted in a practically homogeneous, viscous se, disperse liquid. No sedimentation of solid particles was observed.

The result was a viscosity at 25 ° C. of 3.5 • 10 ³ mPas, at 40 ° C. of 1.7 • 10 ³ mPas and an NH _j number of 24.19.

Dilution of the product with the same amount by weight of the polyol used resulted in a practically homogeneous, viscous, disperse liquid. No sedimentation of solid particles was observed.

The result was a viscosity at 25 ° C of 2.54 • 10τnPas, at 40 ° C of 1.07 • 10 ³ _τιPas and an NH ^ number of 18.8.

Example 4

The procedure was as in Example 1. The reaction time at 170 ° C. was 90 minutes.

A viscous, disperse liquid was obtained. The solid particles tended to settle after a few hours.

The result was a viscosity at 25 ° C. of 2.5 • 10 mPas, an NH _j number of 47.5 and an MDA content of 0.15%.

Example 5

The procedure was as in Example 1. The reaction temperature was 150 ° C. with a reaction time of 45 minutes. It became a highly viscous, disperse liquid with little residual PUR fabrics received.

The viscosity at 25 ° C. was 12 • 10 Pas and one

NH number of 44.

No MDA has been demonstrated.

Example 6

One equipped with a reflux condenser, ^ supply and agitator

The reaction vessel was made with a mixture of

50g polyether polyol (MG 4800)

25g Detda

50g finely divided PUR RRIM waste

80mg DBTDL

charged and heated to 170 ° C. with stirring in an oil bath and kept at this temperature for 60 minutes.

The result was a homogeneous, viscous, disperse liquid. The result was a viscosity at 25 ° C. of 11 · 10 'as, NH _j number of 130 and an MDA content of 0.2%.

Example 7

One equipped with a reflux condenser, ^ supply and agitator

The reaction vessel was made with a mixture of

50g polyether polyol (MW 10000)

12g Detda

50g finely divided PUR RRIM waste

80 mg DBTDL charged and heated to 180 ° C with stirring in an oil bath and 60 Minutes at this temperature.

A viscous, disperse liquid developed.

The result was a viscosity at 25 ° C. of 10.5 · 10 ^ mPas, an NH _j number of 64 and an MDA content of 0.25%.

Example 8

One equipped with a reflux condenser, N _j supply and agitator

The reaction vessel was made with a mixture of

91g polyether polyol (MG 4800)

10g slide inotoluene

25g finely divided PUR RRIM waste

80mg DBTDL

charged and allowed to react at 170 ° C for 60 minutes. A viscous, disperse liquid was obtained.

The result was a viscosity at 25 ° C. of 3.5-10 ³ mPas and an NH _; -Number of 46. No MDA was detected.

Claims

Claims:

1. Process for the production of disperse liquids which contain hydroxy- and / or amino-functional compounds, by reacting polyurethane, polyurethane / polyurea, polyurea wastes which have been produced in the PUR-RIM and / or -RRIM process with at least one diamine compound.

2. The method according to claim 1, characterized in that as diamine compounds aromatic diamines in a Ge weight ratio of polymer waste to diamine of 1: 0.1 to 1: 2, at a temperature of 140 - 180 ° C and a reaction time of 30-120 minutes, optionally in the presence of at least one catalyst.

3. The method according to claim 2, characterized in that a diamine is a compound of the general formula

H ₂ N - R - NH _{2 is} used, where R is an aromatic ring optionally substituted with one or more different or identical alkyl radicals.

4. The method according to claim 2 or 3, characterized in that the weight ratio of polymer waste to diamine is from 1: 0.15 to 1: 0.4.

5. The method according to any one of claims 2 to 4, characterized in that the reaction time is 45-120 minutes and / or the temperature is between 160-180 ° C.

6. The method according to any one of claims 1 to 5, characterized g e k e n n z e i c b. It is not necessary to additionally use a hydroxyl-terminated polyether polyol with a molecular weight of 200-12000 in a weight ratio of polymer waste to polyether polyol of 1: 1 to 1:10.

7. The method according to claim 6, characterized in that the weight ratio of polymer waste to polyether polyol is 1: 1 to 1: 5.

8. The method according to any one of claims 2 to 7, characterized in that an organometallic compound is used as the catalyst.

9. The method according to any one of claims 1 to 8, characterized in that wastes are used which are made up of polyether polyol, aromatic diisocyanants and diethyl toluenediamine.

10. The method according to any one of claims 1 to 9, characterized in that RIM and / or RRIM production waste, optionally with glass fibers and / or lacquer components, is used.

11. Use according to one of claims 1 to 10 disperse liquids prepared for the production of polyurethane, polyurethaneureas or polyureas, in particular according to the RIM and / or RRIM process.