Patent Application
20240392145
This application claims the benefit of French Patent Application Number 2305243 filed on May 26, 2023, the entire disclosure of which is incorporated herein by way of reference.
The present invention relates to solvent compositions, in particular for cleaning solvent-based paints, more particularly for cleaning equipment used in the preparation and/or the application of industrial paints.
At the industrial level, paints are applied as coatings using items of equipment such as pumps, pipes, guns, brushes or rollers. These items of equipment must be cleaned once the application of the paint has been carried out. Likewise, the items of equipment necessary for the preparation of the paint must be cleaned once the paint has been prepared. As these paints are solvent-based, cleaning is carried out using solvents.
Many solvents, for example organic or water-based, are available today. However, depending on their compositions, they exhibit variable characteristics of effectiveness, of dangerousness during use or of storage and of pollution.
This is because the paints used in industry, for example to coat mechanical parts, have variable compositions. They can in particular be based on polyepoxide, on polyurethane or on other types of polymers. Some solvents are not capable of dissolving any type of paint and can leave residues or also create precipitates.
Moreover, the flash point of a solvent is an essential characteristic in terms of dangerousness. This is because the flash point determines the flammability of the solvent. This is the lowest temperature at which a product releases enough vapor to form a flammable mixture with the air. A solvent exhibiting an excessively low flash point with respect to its conditions of use or of storage thus presents serious risks.
Finally, it is known that solvents are one of the main sources responsible for the emission of volatile organic compounds, or VOCs. In point of fact, more and more companies are now committed to reducing the environmental impact of their industrial processes and are implementing environmental management systems, in particular in accordance with the standards in force, such as Standard ISO 14001.
The aim of the present invention is to provide solvent compositions, in particular for the cleaning of items of equipment for the preparation and/or application of solvent-based paints or other surface coatings, which simultaneously exhibit a certain effectiveness for these paints, a reduction in the risks of flammability related to the flash point during use or storage and a controlled environmental impact, in particular in terms of emissions of volatile organic compounds.
To this end, the invention relates to a solvent composition for paints or other coatings, comprising dimethyl glutarate and at least one other compound chosen from isobutyl acetate, ethyl lactate, dimethyl 2-methylglutarate, 2-methyltetrahydrofuran, ethyl acetate, cyclopentyl methyl ether, diethoxymethane, dimethyl carbonate, dimethyl succinate, benzyl alcohol, dimethyl adipate or glycerol triacetate.
The composition according to the invention is shown to be entirely effective in dissolving the solvent-based paints generally used in industry, such as primer paints, base coats, top coats, varnishes, in particular paints or other coatings based on polyurethane, on polyepoxides or on other types of polymers, and thus efficiently cleaning the items of equipment for the preparation and/or application of paints.
The composition according to the invention can be used with a limited risk of flammability. This is because, whatever the combinations of components proposed, these will exhibit a minimum flash point suitable for the conditions of use and of storage.
Thus, advantageously, the composition according to the invention exhibits a flash point of greater than or equal to 39° C.
The flash point can be determined according to known closed cup methods, in particular by following Standard EN ISO 3679 (or any other standard in force specifying flash point test procedures for paints).
Also advantageously, the composition exhibits a content of volatile organic compounds of less than 50% by weight.
The content of volatile organic compounds can be measured according to known methods, by following Standard EN ISO 11890-1 (or any other standard in force specifying procedures for measuring VOCs for paints), in particular by following the measurement method 1 set out in Standard EN ISO 11890-1. According to this method, the percentage by weight of volatile organic compounds is calculated according to the following formula:
in which:
Preferentially, the composition comprises at least 40% by volume of dimethyl glutarate, with respect to the total volume of the composition.
According to a preferred embodiment of the invention, the composition comprises dimethyl glutarate in combination with isobutyl acetate and/or ethyl lactate.
Advantageously, the composition consists solely of dimethyl glutarate in combination with isobutyl acetate and/or ethyl lactate.
Advantageously, the composition comprises between 50% and 80% of dimethyl glutarate and between 20% and 50% of isobutyl acetate and/or of ethyl lactate, by volume, with respect to the total volume of the composition.
According to one embodiment, the composition comprises between 50% and 55% of dimethyl glutarate, between 30% and 35% of isobutyl acetate and between 20% and 25% of ethyl lactate, by volume, with respect to the total volume of the composition.
According to another embodiment, the composition comprises between 50% and 55% of dimethyl glutarate, between 30% and 35% of ethyl lactate and between 20% and 25% of isobutyl acetate, by volume, with respect to the total volume of the composition.
According to another embodiment, the composition comprises between 50% and 55% of dimethyl glutarate and between 45% and 50% of ethyl lactate or of isobutyl acetate, by volume, with respect to the total volume of the composition.
According to another embodiment, the composition comprises between 70% and 80% of dimethyl glutarate and between 20% and 30% of isobutyl acetate, by volume, with respect to the total volume of the composition.
Preferentially, the composition according to the invention comprises at most 20% of a compound chosen from dimethyl 2-methylglutarate, 2-methyltetrahydrofuran, ethyl acetate, cyclopentyl methyl ether, diethoxymethane, dimethyl carbonate, dimethyl succinate, benzyl alcohol, dimethyl adipate or glycerol triacetate or of one of their mixtures, by volume, with respect to the total volume of the composition.
The invention also relates to a process for cleaning items of equipment for the preparation and/or application of solvent-based paints or of other coatings, characterized in that it comprises at least one stage of cleaning said items of equipment using a solvent composition as defined above.
The abovementioned characteristics of the invention, and also others, will become more clearly apparent on reading the examples which follow and in connection with the following appended drawings:
Five solvent compositions (Sol 1; Sol 2; Sol 3; Sol 4; Sol 5) according to the invention were prepared according to the mixtures shown in Table 1 (
Their effectiveness with regard to the dissolution of different types of paints was compared with that of a commercial control solvent.
The trade names of the paints, as well as their main component, are also shown in Table 1 (
The results of the effectiveness tests and also the flash point of each solvent composition are shown in Table 1 (
The effectiveness with regard to the dissolution of different types of paint was determined using the device 100 illustrated in
It is noticed first of all that the five solvents according to the invention exhibit a flash point of greater than 39° C., whereas the control solvent exhibits a flash point of 26° C. At such a value, the control solvent cannot be used without danger, whereas the five solvents according to the invention can be used and stored more safely.
Furthermore, the five solvents according to the invention have been shown to be effective in dissolving all the layers of paint. Their effectiveness, compared to that of the controls, is much higher. This is because, compared with the control solvent, the solutions 1, 2, 3, 4 and 5 exhibit an effectiveness of 58%, 50%, 42%, 75% and 42% respectively. Compared with the recycled control solvent, the solutions 1, 2, 3, 4 and 5 exhibit an effectiveness of 67%, 67%, 50%, 92% and 58% respectively.
It is noted in particular that the solvent 4 stands out in terms of effectiveness.
The contents of volatile organic compounds (VOCs) of the 5 solvent compositions according to the invention are presented in Table 2 (
The five solvents according to the invention exhibit an acceptable content of VOCs of less than 50%, whereas the control solvent exhibits a content of VOCs of 100%.
While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2305243 | May 2023 | FR | national |
