EP2625258A1

EP2625258A1 - Polymer-cleaning composition

Info

Publication number: EP2625258A1
Application number: EP11779790.2A
Authority: EP
Inventors: Mélanie VAUTHRIN; Bernard Monguillon; Paul Guillaume Schmitt
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2010-10-05
Filing date: 2011-10-04
Publication date: 2013-08-14
Anticipated expiration: 2031-10-04
Also published as: CA2809850C; CN103119148B; US20130310297A1; AU2011311433A1; PL2625258T3; SI2625258T1; WO2012045971A1; JP5823524B2; FR2965567A1; JP2014500161A; AU2011311433B2; CN103119148A; KR20150070414A; TR201903049T4; EP2625258B1; BR112013008332A2; KR20130060323A; FR2965567B1; US9212340B2; CA2809850A1

Abstract

The present invention relates to a dimethyl sulfoxide composition suitable for cleaning polymer residue found on the devices used for processing plastic materials, in particular polyurethane.

Description

COMPOSITION FOR CLEANING POLYMERS

The present invention relates to the field of plastics processing, more specifically the field of molding, injection molding, injection molding, extrusion, extrusion molding, and other techniques. processing of plastics.

More specifically, the invention deals with the cleaning of various devices used in the plastics processing industries. These devices are for example molds, injection nozzles, extrusion screws, and, in general, all the parts, most often but not necessarily metal, which come into contact more or less prolonged with one or more plastics brought to higher or lower temperatures and cooled to allow their transformation.

During these operations of transformations, such as moldings of articles or plastic objects, polymer residues of various shapes and sizes more or less important, can remain in contact with the mold. In particular, during demolding, opening of the molds, polymer residues can be torn off the molded object and adhere to the walls of the mold.

It is the same in the extrusion screws, the injection nozzles, and all parts of the processing apparatus in contact with the plastics. It is imperative to clean, that is to say, to remove all these residues adhering to molds, screws, nozzles and others, in order to perform new subsequent operations of molding, extrusion, and others.

These cleaning operations to remove the polymer residues are most often carried out today by contacting said residues with one or more solvents or solvent mixtures.

These solvents are most often organic solvents, some of which are smelly, more or less toxic and harmful to the environment, but also especially toxic and harmful to users responsible for cleaning said polymer residues. Many of these solvents are now banned, or will be, either by government directives or directly by the will of the industry themselves, anxious to preserve the health of their employees.

For example, it is known that the molds used for the manufacture of polyurethane articles are generally cleaned with dimethylformamide (DMF) which is considered today as harmful and toxic.

Also, a first object of the present invention is to provide new products, formulations, compositions, cleaning of polymer residues which are less toxic and less harmful than the solvents used today, or even products, formulations, compositions, cleaning of non-toxic residues and not harmful to the environment and for users.

Another object of the present invention is to provide products, formulations, compositions, cleaning polymer residues that are more effective than known solvents and used today.

Still other objects will become apparent from the description of the present invention which follows.

It has now been found that it is possible to achieve the above objectives at least in part, or in whole using, as a polymer cleaning composition a mixture comprising dimethylsulfoxide (DMSO) and at least one amine.

The composition of the invention comprises, and according to preferred aspect consists of, DMSO and at least one amine, optionally with water and / or at least one additive.

More specifically, the present invention relates to a composition comprising, and preferably consisting of:

from 40% to 95% dimethylsulfoxide (DMSO);

from 1% to 60% of at least one amine;

from 0% to 30% of water; and

from 0% to 10% of at least one additive.

In the description of this invention, all percentages are by weight, unless explicitly stated otherwise. DMSO is a solvent considered to be non-harmful and nontoxic. In addition, it may be available in various degrees of purity, the high purity DMSO having virtually no odor, at least no foul odor. According to one variant, the DMSO used can advantageously be perfumed with at least one odorant.

According to a preferred embodiment, the composition according to the invention comprises, and preferably consists of:

from 50% to 95%, preferably from 60% to 97%, dimethylsulfoxide (DMSO);

from 1% to 30%, preferably from 2% to 20%, of at least one amine;

from 0% to 30% water, preferably from 0% to 15%; and

from 0% to 10%, preferably from 0% to 5%, of at least one additive.

The amine (s) present (s) in the composition of the invention may be of any type known to those skilled in the art. However, primary, secondary or tertiary amines with a molecular weight of less than 500 Dalton, preferably less than 300 Dalton, more preferably less than 200 Dalton, more preferably less than 100 Dalton, are preferred. Primary or secondary amines are preferred, with primary amines being most preferred.

Amines having a single amino function are preferred. Amines further comprising at least one oxygen atom, and preferably one or two oxygen atoms, are also preferred.

Among these, it is further preferred amines having one or two groups selected from hydroxy-alkyl and alkoxy-alkyl, wherein alkyl represents methyl, ethyl, propyl or butyl. Particularly preferred are amines having one or two hydroxyethyl groups and / or a methoxy group. Amines carrying one or two hydroxy-ethyl groups being the most preferred.

By way of nonlimiting examples, the amines which can be advantageously used in the compositions according to the invention are chosen from alkylalkanolamines, alkyldialkanolamines, alkoxyamines.

According to one embodiment, and among the amines that can be used in the compositions of the invention, mention may be made, by way of nonlimiting examples, of monoethanolamine (MEOA), diethanolamine (DEOA), propanolamine (PoA), the butyl / ^{'so-propanolannine} (Bipoa), Γ ^/' so-propanolannine (IPOA), 2- [2- (3- amino-propoxy) ethoxy] -ethanol, N-2-hydroxyethyldiethylenetriamine, (3-methoxy) -propylamine (MoPA), 3-isopropoxypropylannine (IPOPA), and triethylamine (TE A).

According to a very particularly preferred aspect, the compositions according to the invention comprise at least one amine chosen from monoethanolamine (MEoA), diethanolamine (DEoA), propanolamine (PoA) and (3-methoxy) -propylamine ( MoPA), more preferably monoethanolamine (MEoA) and diethanolamine (DEoA).

In addition to the DMSO and at least one amine, as they have just been defined, the presence of a quantity of water in the compositions of the invention has proved advantageous to allow an even more effective dissolution. of polymer residues.

Furthermore, the presence of water in the compositions of the invention has the additional advantage of lowering the crystallization point of said compositions.

Thus, and according to yet another aspect, the present invention relates to a composition comprising, and preferably consisting of:

from 40% to 95% dimethylsulfoxide (DMSO);

from 1% to 60% of at least one amine;

from 1% to 30% water; and

from 0% to 10% of at least one additive.

In a preferred embodiment, the present invention relates to a composition comprising, and preferably consisting of:

from 50% to 95%, preferably from 60% to 97%, dimethylsulfoxide (DMSO);

from 1% to 30%, preferably from 2% to 20%, of at least one amine;

from 1% to 30% of water, preferably from 1% to 15%; and

from 0% to 10%, preferably from 0% to 5%, of at least one additive.

Finally, the compositions according to the present invention may comprise one or more additives commonly used in the field. These additives advantageously have no inherent or intrinsic properties of cleaning, or dissolving polymers. Among the additives that may be present in the compositions according to the invention, mention may be made, by way of non-limiting examples, of corrosion inhibitors, antioxidants, colorants, flavorings and other odor masking agents, stabilizers, wetting agents and others.

Among the corrosion inhibitors, mention may be made of catechol, sodium tolyltriazolate and morpholine, for example.

A particularly preferred composition for cleaning polymeric residues according to the present invention comprises, and preferably consists of, 80% to 90% DMSO, 2% to 9% MEoA and 5% to 15%, for example about 8% water. This composition may further comprise a few ppm by weight to 1% of a corrosion inhibitor.

In yet another aspect, the compositions of the present invention may comprise, instead of DMSO, a mixture of DMSO and at least one other non-nitrogenous solvent. Among the non-nitrogenous solvents, mention may be made, by way of non-limiting examples, of alcohols, ethers, esters and other non-nitrogenous solvents compatible with the compositions as just described.

Among the additional non-nitrogenous solvents which can form a mixture with the DMSO present in the compositions of the present invention, the esters, which are mono-functional and / or di-functional, and more particularly the alkyl esters, are preferred. where "alkyl" denotes a hydrocarbon chain, linear or branched, comprising from 1 to 6 carbon atoms. These esters advantageously come from mono- and / or dicarboxylic acids containing from 3 to 30 carbon atoms, in a linear or branched chain.

Particularly preferred methyl, ethyl, propyl and butyl esters of formic acid, acetic, propionic, butyric, maleic, succinic, glutaric, 2-methylglutaric, and others, and mixtures thereof in all proportions.

Thus, in a preferred embodiment, the invention relates to a composition comprising, and preferably consisting of: from 50% to 95%, preferably from 60% to 97%, of a dimethylsulfoxide (DMSO) / non-nitrogenous solvent mixture selected from alcohols, ethers and esters;

from 1% to 30%, preferably from 2% to 20%, of at least one amine;

from 0% to 30% water, preferably from 0% to 15%; and

from 0% to 10%, preferably from 0% to 5%, of at least one additive.

According to another preferred embodiment, the invention relates to a composition comprising, and preferably consisting of:

from 50% to 95%, preferably from 60% to 97%, of a dimethylsulfoxide (DMSO) / non-nitrogenous solvent mixture selected from alcohols, ethers and esters;

from 1% to 30%, preferably from 2% to 20%, of at least one amine;

from 1% to 30% of water, preferably from 1% to 15%; and

from 0% to 10%, preferably from 0% to 5%, of at least one additive.

In the compositions according to the invention which comprise a DMSO / non-nitrogenous solvent mixture, those for which the weight ratio DMSO / non-nitrogenous solvent is between 99/1 and 30/70, preferably between 90/10, are preferred. and 40/60, for example the weight ratio is about 50/50.

The compositions of the invention may be prepared according to any method known in the art, and for example by simply mixing the various ingredients in any order. However, it is preferred to add the amines in the DMSO / water mixture, in the case where the latter is present in the composition. The optional additives are advantageously added to the final mixture DMSO / amine (s) and optionally water.

According to another aspect, the subject of the present invention is the use of at least one of the compositions as they have just been defined, for the partial or total dissolution of polymers, and in particular for the cleaning of polymer residues.

By cleaning polymer residues is meant the partial or total dissolution of polymers with the compositions of the present invention.

Polymers that can be partially or completely dissolved are of all types, thermoplastic and thermosetting, in particular thermoplastics. The polymers contemplated in the use of the present invention are for example chosen from, in a nonlimiting manner, fluorinated polymers, such as poly (vinyl difluoride) or PVDF, nitrogen-containing polycondensates, such as those containing amide, imide, amido-amide, urethane, nitrile groups, sulfur-containing polycondensates, such as those bearing sulphone groups, and the like.

The compositions of the invention are particularly suitable for cleaning polymers selected from polyurethanes, polyamides, polyamide-imides, polyether sulfones, polyacrylonitriles, and the like, and more particularly suitable for dissolving, cleaning of polyurethanes.

The compositions of the invention are particularly effective for the cleaning of polyurethane residues for which the solvent of choice until now was DMF which is now prohibited, in particular by European directives.

For the cleaning of polymer residues, the compositions of the present invention are implemented in a temperature range from room temperature to 90 ° C. The effectiveness of the compositions according to the invention decreases rapidly when the temperature decreases, and, below the ambient temperature, the time required for effective cleaning can be relatively long. Above 90 ° C, the cleaning composition can generate annoying vapors, but it is possible to work in ventilated or closed enclosure, thus allowing to work at the boiling temperature of the cleaning composition.

However, it is preferred to use the compositions according to the invention at a temperature between 30 ° C and 70 ° C, for example between 50 ° C and 65 ° C.

According to yet another aspect, the present invention relates to a method for cleaning polymer residues present on devices used in the transformation of plastics as defined above, said method comprising at least one step of contacting said contaminated apparatus by said polymer residues, with at least one composition according to the present invention, under the temperature conditions indicated above. By contacting is meant a partial or complete immersion of the apparatus to be cleaned, with or without agitation, a spray of the apparatus to be cleaned with a cleaning composition at various pressure, for example by means of a brush, spray gun, and others. Alternatively the contacting can be simply wiping with a cloth, sponge or other absorbent / desorbent material soaked with the cleaning composition.

The bringing into contact defined above may optionally be accompanied by a physical cleaning, for example using tools, such as spatulas, scrapers, and others.

The present invention is now illustrated by means of the examples which follow, without presenting any limiting character, and which can not therefore be understood as likely to restrict the scope of the invention as claimed.

Example 1 Dissolution of Polyurethane (PU) Using DMF and DMSO

For carrying out the tests illustrating the invention, polyurethane residues from shoe sole molds were used.

The reference solvent is DMF; for cleaning the molds, they are usually immersed for a few hours in a DMF bath heated to 60 ° C.

The tests are performed here in 20 ml glass bottles. 10 ml of the cleaning composition (in this case DMF on the one hand and DMSO alone on the other hand) preheated in an oven at approximately 60 ° C. is introduced into each flask. A sample of polyurethane (PU) of parallelepipedal shape (about 10 × 5 × 2 mm) is then introduced into each bottle. The flasks are closed and left without stirring in the oven at 60 ° C.

First observed swelling of the samples after about 2 to 3 minutes of immersion. After 25 minutes, the PU is not dissolved in either DMF or DMSO. The difference in efficacy between DMF and DMSO is observed over time: after 18 hours at 60 ° C, PU begins to solubilize in DMF while nothing happens in DMSO. DMF is therefore more efficient than DMSO alone. Example 2 Dissolution of Polyurethane (PU) in a Mixture

DMSO / non-nitrogenous solvent

The same protocol as in Example 1 is repeated using a mixture of DMSO (95.5%) and diacetone alcohol (4.5%). As in DMSO, the DMSO / diacetone alcohol mixture is observed to swell the PU, but no dissolution, even after 18 hours immersion of the sample.

A comparable test was carried out with a DMSO / hexylene glycol mixture. Similarly, it is observed that hexylene glycol provides no additional efficiency. This mixture acts like DMSO and is less effective than DMF.

The addition of an oxygenated solvent, non-nitrogen, DMSO does not improve the effectiveness of DMSO alone and remains a less efficient solution than dissolution with DMF.

Example 3 Dissolution of Polyurethane (PU) in a Mixture

DMSO / MEOA

The same protocol as in Example 1 is repeated using a mixture of DMSO (95.5%) and monoethanolamine (4.5%), immersion for 18 hours at 60 ° C.

Surprisingly, it is observed that the PU sample is completely dissolved in the DMSO / MEoA mixture, while in the DMF, the sample just begins to dissolve.

A DMSO / MEoA mixture is therefore significantly more effective than DMF alone.

Example 4 Dissolution of Polyurethane (PU) in a Mixture

DMSO / MEoA, with and without added water

The same protocol as in Example 1 is repeated by comparing a composition DMSO / MEoA (95.5% / 4.5%) and a composition DMSO / MEoA / Water (87.5% / 4.5% / 8% ). After 4h at 60 ° C, the PU is completely dissolved in the mixture DMSO / MEoA / water, while it is not dissolved in the mixture DMSO / MEoA (95.5% / 4.5%) .

A DMSO / MEoA / water mixture is therefore significantly more effective than a DMSO / MEoA mixture.

EXAMPLE 5 Influence of the Proportion of Nitrogen Solvent in DMSO on Polyurethane (PU) Dissolution

Still according to the protocol described in Example 1, the PU sample dissolution tests are carried out, by varying the concentration of MEoA in DMSO, by 1 to 5%.

It is observed that the more the amount of MEoA in the DMSO increases, the more the dissolution of the PU is fast.

In addition, the mixture DMSO + 1% MEoA is more effective than DMF alone, because already after 1 hour at 60 ° C, we begin to see flakes of PU suspended in the mixture, while no effect (except swelling of the sample) is observed, neither the DMF nor in the DMSO.

After 48 hours at 60 ° C, the PU is completely dissolved in the mixture DMSO + 1% MEoA. The addition of MEoA in DMSO (from 1% to 5%) markedly increases the dissolution of PU relative to DMSO alone. DMSO + MEoA is more effective than DMF.

Example 6: Lowering of the crystallization point in the presence of water in cleaning compositions based on DMSO

The crystallization point of the DMSO is 18.5 ° C., which often poses storage and handling problems in the winter period.

The crystallization point of a mixture DMSO (95%) + MEA (5%) is about 15 ° C. This crystallization point can be further increased by adding water to the composition.

A test is carried out by adding 8% by weight of water in DMSO, then the MEoA is added (5% by weight in the above mixture). Point of Crystallization of this mixture is measured at -2.9 ° C, while a DMSO / water mixture (92% / 8%) has a crystallization point close to 0 ° C.

According to the protocol of the example, dissolution tests are carried out on this DMSO / MEoA / water mixture (ie 87.6% / 4.8% / 7.6%).

After 3 hours at 60 ° C, the PU sample is completely dissolved in this mixture, whereas it only begins to dissolve in the DMSO / MEoA mixture (95% / 5%) and no dissolution. is still observed in DMF: the addition of water in the DMSO / MEA mixture accelerates the dissolution of the PU.

Example 7 Influence of the Water Content on the Dissolution of Polyurethane (PU) in a DMSO / MEoA / Water Mixture

The same protocol as in Example 1 is repeated comparing DMSO / MEoA / water compositions with variable water contents.

After 7 hours at 60 ° C, the results are as follows:

91.5% DMSO / 4.5% MEOA / 4% water: polymer not completely dissolved;

87.5% DMSO / 4.5% MEoA / 8% water: fully dissolved polymer;

80.5% DMSO / 4.5% MEOA / 15% water: any early dissolution of the polymer;

- 70.5% DMSO / 4.5% MEoA / 25% water: no dissolution of the polymer;

- 45.5% DMSO / 4.5% MEoA / 50% water: no dissolution of the polymer.

It can therefore be concluded that a water content of up to 15% significantly improves the dissolution efficiency of the DMSO / MEoA / water compositions.

Example 8 Dissolution of Polyurethane (PU) in a Mixture

DMSO / non-nitrogen solvent / M EoA / water

The same protocol as in Example 1 is repeated using a mixture of DMSO (50% by weight) and dimethyl glutarate (50% by weight). As in DMSO, dimethyl DMSO / 2-methylglutarate is observed to swell the PU, but no dissolution, even after 18 hours immersion of the sample.

A comparable test was carried out with a mixture of dimethyl DMSO / 2-methylglutarate / MEoA / water (44.5% - 44.5% - 3% - 8% by weight). weight). After 18 hours of immersion of the PU sample, the latter is totally dissolved.

The addition of MEoA and water under the conditions of the invention to a non-nitrogenous DMSO / solvent mixture significantly improves performance compared to the DMSO / non-nitrogen solvent alone mixture.

Claims

A composition comprising, and preferably consisting of:

from 50% to 95%, preferably from 60% to 97%, dimethylsulfoxide (DMSO);

from 1% to 30%, preferably from 2% to 20%, of at least one amine;

from 0% to 30% water, preferably from 0% to 15%; and

from 0% to 10%, preferably from 0% to 5%, of at least one additive.

The composition of claim 1 comprising, and preferably consisting of:

from 50% to 95%, preferably from 60% to 97%, dimethylsulfoxide (DMSO);

from 1% to 30%, preferably from 2% to 20%, of at least one amine;

from 1% to 30% of water, preferably from 1% to 15%; and

from 0% to 10%, preferably from 0% to 5%, of at least one additive.

3. A composition according to claim 1 or claim 2, wherein the amine or amines are primary, secondary or tertiary amines of molecular weight less than 500 Dalton, preferably less than 300 Dalton, more preferably less than 200 Dalton, more preferably, less than 100 Dalton, the primary or secondary amines being preferred, the primary amines being very particularly preferred.

4. Composition according to any one of the preceding claims, wherein the amine or amines comprise a single amine function and at least one oxygen atom, preferably one or two oxygen atoms.

5. Composition according to any one of the preceding claims, wherein the amine or amines comprising one or two groups selected from hydroxy-alkyl and alkoxy-alkyl, wherein alkyl represents methyl, ethyl, propyl or butyl, preferably one or two groups. hydroxyethyl and / or methoxy group, more preferably one or two hydroxyethyl groups.

6. A composition according to any preceding claim, wherein the or the amines are chosen from monoethanolamine (MEOA), diethanolamine (DEOA), propanolamine (PoA), the butyl / ^{'n-propanolamine} ( BiPoA), n-propanolamine (iPoA), 2- [2- (3-aminopropoxy) ethoxy] ethanol, N-2-hydroxyethyldiethylenetriamine, (3-methoxy) -propylamine (MoPA), 3-isopropoxypropylamine (IPOPA), and triethylamine (TEA), more preferably monoethanolamine (MEoA) and diethanolamine (DEoA).

7. Composition according to one of the preceding claims comprising, and preferably consisting of, from 80% to 90% of DMSO, from 2% to 9% of MEoA and from 5% to 15%, for example approximately 8% of water, and optionally from a few ppm by weight to 1% of a corrosion inhibitor.

8. Composition according to one of the preceding claims, wherein the DMSO is a mixture of DMSO and at least one other non-nitrogenous solvent selected from alcohols, ethers, esters, and other non-nitrogenous solvents compatible with said compositions. , preferably chosen from monofunctional and / or di-functional esters.

9. Composition according to one of the preceding claims, wherein the DMSO is a mixture of DMSO and at least one other non-nitrogenous solvent, the weight ratio DMSO / non-nitrogenous solvent being between 99/1 and 30/70, preferably between 90/10 and 40/60, for example about 50/50.

10. Use of at least one composition according to any one of claims 1 to 9, for the partial or total dissolution of polymers.

11. Use according to claim 10, in which the polymer is a thermoplastic or thermosetting polymer, preferably a thermoplastic polymer, chosen from fluorinated polymers, sulfur-containing polycondensates and nitrogen-containing polycondensates, preferably those bearing amide, imide, amido-amide, urethane, nitrile and other groups.

The use of claim 10 or claim 11, wherein the polymer is a polyurethane.

13. A method for cleaning polymer residues present on devices used in the processing of plastics, said method comprising at least one step of contacting said apparatus contaminated with said polymer residues, with at least one composition according to one of the following: any of claims 1 to 9, at a temperature between room temperature and 90 ° C, preferably between 30 ° C and 70 ° C, for example between 50 ° C and 65 ° C.

The method of claim 13, wherein the apparatus used in plastics processing is a mold, an injection nozzle, an extrusion screw, and the like.