NON-FLAMMABLE, VOLATILE AND AQUEOUS CLEANING COMPOSITION

Abstract

 The present invention concerns a new non-flammable, volatile and aqueous cleaning composition.

Description

Technical field of the invention

[0001] The present invention concerns a new non-flammable, volatile and aqueous cleaning composition, and its use for example as a degreaser for metal, ceramic or polymer parts in the mechanical, industrial, agricultural or consumer fields. As it does not leave residues, the composition can also be used on glass surfaces (e.g. vehicle windscreens), glass-ceramics. The cleaning of natural or synthetic textiles can also be considered.

[0002] In the description below, references in square brackets ([ ]) refer to the list of references at the end of the text.

State of the art

[0003] Detergent formulations for glass surfaces are often based on mixtures of water and water-soluble solvents such as monohydroxy alcohols (usually ethyl alcohol, isopropyl alcohol), which are known for their degreasing efficiency. In addition, these same solvents ensure rapid drying of surfaces without leaving residues or traces. However, these same solvents are the main cause of the regulatory classification of these mixtures as flammable due to a flash point less than or equal to 60°C. Thus, the storage and transport of these compositions must comply with the drastic directives and regulations in force in order to ensure the safety of goods and people, generating non-negotiable costs.

[0004] Outdoor storage may then be preferred, as natural ventilation evacuates any vapors and does not allow the lower flammability limits to be reached. Cold winter conditions, however, give rise to other problems such as freezing or phase shifting of the mixtures.

[0005] In addition, there is a conflict between the properties of flammability, freezing point and vapor pressure, which must be resolved in accordance with the requirements of safety, decontamination, antistatic properties and protection against corrosion.

[0006] Under these conditions, the removal of dirt (dust, gum, lacquer, spray marks, etc.) from glass surfaces is another requirement which implies taking into account the solubility power but also eliminating conventional stain removers which are not (very) effective such as inorganic salts, acids (e.g. citric acid, formic acid or their acetates) or corrosive alkalis (e.g. sodium hydroxide).

[0007] The development of compositions based on surfactants has often been the means to achieve ideal stain removal by a separation mechanism, emulsion soluble in the water formed, thus achieving the cleaning and soil removal action. However, all surfactants do not provide the required properties.

[0008] To ensure effective detergency without residues after evaporation while guaranteeing the non-flammability of the composition, the main solution is to use fluids or solvents which are difficult to ignite, might be quite volatile but still have high flash points. Halogenated hydrocarbons such as tetrachloromethane meet these criteria perfectly. Their vapor pressure of more than 10 kPa at 20°C ensures rapid evaporation, while their freezing point of less than -20°C guarantees their use over a wide temperature range.

[0009] The use of halogenated hydrocarbons such as perfluoroalkyl ethylenes (e.g. in particular perfluorobutyl ethylene), is for example described in Patent EP0443911 [1].

[0010] The 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) has also been widely recognized for its cleaning properties but much research has sought to replace it to reduce environmental impact.

[0011] In Patent EP0347924 [2], this environmental problem is circumvented by compounds of the type CH_aCl_bF_cCF₂CH_xCl_yF_z with a+b+c=3, x+y+z=3, a+x≥1, b+y≥1, and 0≤a,b,c,x,y,z≤3 which demonstrate excellent detergent properties, alone or in combination with more conventional solvents (cetones, esters, acoohols, hydrocarbons, etc...) or surfactants (anionics, cationics, non-ionics or amphoterics).

[0012] The combined use of these solvents is justified in Patent Application US2031145 [3]. The author explains that for a sufficient quantity of non-flammable solvent, the incorporation of flash-point solvents does not modify this characteristic of non-flammability, as long as the vapor pressures are of the same order of magnitude. A mixture of tetrachloroethane (13kPa at 20°C) and light naphtha solvents (0.3kPa at 20°C) illustrates this point.

[0013] The use of 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone (FK-5-1-12), used as a second generation inhibitor gas in automatic extinction, also makes it possible to produce a non-flammable azeotropic mixture with the dichloroethylene and trans-1-chloro-3,3,3-trifluoropropene.

[0014] However, the use of halogenated hydrocarbons raises many safety problems.

[0015] On the one hand, global agreements govern their use, as many sub-families are involved in global climate change. 2015 notably marked the end of the use of chlorofluorocarbons (CFC) and hydrochlorofluorocarbons (HCFC), and the ban of Hydrofluorocarbons (HFC) will come into effect in 2030. On the other hand, chlorinated solvents often cause significant problems of acute toxicity, which affects the safety of users.

[0016] The use of aqueous solutions is a more common way of achieving the objective of non-flammability and at the same time ensuring better health safety for the user. In Patent US9,085,751 [4], through the combination of hydrophobic and hydrophilic solvents chosen from respective flash point ranges 40-70°C and 50-80°C, effective non-flammable but versatile cleaners have been created. However, their use is claimed to be under agitation, as this type of mixture is cloudy, unstable and separates into 2 phases in less than 10 minutes according to the authors. In the absence of antifreeze agents, in addition, these products are susceptible to solidification as soon as the ambient temperature drops below 0°C.

[0017] Above all, as is known to the person skilled in the art and as shown for example by Patent US8,845,817 [5], the combination of various ionic or non-ionic surfactants with small amounts of solvents in an aqueous medium (89,45% to 97,77%) (w/v) makes it possible to obtain multipurpose, biodegradable and non-flammable detergents.

[0018] The use of a monoisopropylamine lactate in the aqueous base cleaning formulations of Patent US9,879,204 [6] allows the freezing temperature to be reduced to -12°C.

[0019] In addition to their cleaning power, glycol ethers are also known for their antifreeze power. The amounts below 10% claimed in many documents (International Application WO2017/011216, US8,114,223) [7,8] are not sufficient to achieve sufficient antifreeze power, based on comparative data with ethylene glycol (10% aqueous solution freezes at -5°C) and on the law of cryometry (the lowering of the solidification temperature is proportional to the molar fraction of the solute).

[0020] In Patent US5,486,314 [9], a formula consisting in a dipropyleneglycol ethylether (vapor tension 40Pa) major phase at 80%, supplemented with dipropyleneglycol dimethylether (15%) and 1-amino-2-butanol (5%) shows very good cleaning results on oil and grease. Its flash point of 73°C perfectly matches the flammability objective. The main phase ensures a minimal evaporation.

[0021] The cleaning compositions without volatile organic compounds (COV) disclosed in Patent Application US2016/0230127 [10] could meet this requirement of evaporation and low melting point. However, the use of acetone (closed cup flash point -18°C) makes these mixtures flammable.

[0022] In addition, many Patents claiming non-flammable compositions are based on the old criteria of the United States Health and Safety Administration (OSHA). Prior to the adoption of the GHS system in 2012, a liquid was classified as flammable if its flash point was less than 100°F (38°C), while the GHS system raises this limit to 60°C. For this reason, the literature prior to 2012 should be used with caution. Thus, a mixture of ethyl lactate and isoparaffins stabilized by a propyleneglycol methyl (or propyl) ether claimed by the International Application WO94/03579 [11] should not be considered as non-flammable as defined in the new regulations.

[0023] There is therefore still a need for non-toxic, environmentally friendly cleaning compositions that solve non-flammability, low freezing point and high vapor pressure antagonisms in accordance with manufacturing, transport and storage safety requirements.

Description of the invention

[0024] The purpose of the invention is thus to provide a multi-surface cleaning composition having limited manufacturing, transport and storage requirements and respecting the health and safety of the user and the environment, with contradictory properties:

• Cleaning or stain removal properties for effective removal of various soils, to improve the appearance of surfaces but also in preparation for the application of coatings such as paint, adhesive, water repellent treatment, etc.... The term soiling includes contaminants such as dust, oil or grease splashes, fingerprints, ink, animal droppings and crushed insects.
• The cleaned surfaces must be restored to their original appearance. This means that they must not be altered in any way, regardless of the nature of the surface (paint, plastic, rubber, metal, glass). The above-mentioned changes in appearance include major defects such as corrosion, staining, blistering, swelling, delamination, etc. These changes also include minor defects such as discoloration or deposits from the composition after drying (otherwise known as traces on glass surfaces).
• Exemption from the precautions associated with the transport of class 3 flammable liquids under ADR regulations for road transport, RID for rail transport, IATA for air transport or IMDG for sea transport implies that the closed cup flash point of the compound must be strictly above 60°C as measured by one of the following methods: ISO1516, ISO1523, ISO2719, ISO13736, ISO3679 or ISO3680.
• Commercial transport often exposes products to temperatures below 0°C. During the winter months, an average temperature of -15°C is recorded in the countries most exposed to cold (Canada, Scandinavia, etc.). In addition, end-users often store cleaning products in poorly heated or unheated places (garage, window sill, car boot,...). These conditions can be sufficient to cloud, thicken, gel or even freeze the product. The result is difficulties in use, whatever the method of application (pouring, pump, spray, etc.) and possible long-term stability issues (phase separation, precipitation, etc.). A cleaning product with a freezing temperature lower than or equal to -20°C would thus limit these problems.
• In addition, to enable the public use, the product must not contain any substance of very high concern as listed in Annex XVII of REACH, or candidate to this list as published in accordance with Article 59, paragraph 10, of the REACH Regulation.
• For tank use, the composition must be fully miscible with most detergent compositions. Because of the need to protect users and the environment, most of these compositions are water-based. The cleaner will therefore be required to be fully miscible with water to ensure this property.
• The evaporation rate of the formulation must be high enough to dry the surfaces over a short period of time, but slow enough for the cleaning action (chelation, dissolution, emulsion...) to occur even on the most encrusted dirt. Optimum evaporation has been determined to be in the range between the behaviour of water and ethanol. If the environment is inseparable from the drying capacity (temperature, gas flow, covered surfaces,...), the vapor pressure represents an objective thermodynamic quantity closely linked to evaporation, and easily measured experimentally. The formulation should therefore preferably have a vapor pressure higher than that of water (2.3 kPa at 20°C) but lower than that of ethanol (5.95 kPa at 25°C).

[0025] The composition is biodegradable according to the OECD 302B method.

[0026] The composition does not affect metal surfaces. After 120h contact at 50°C, carbon steel, stainless steel, copper, brass and aluminum samples show a negligible mass change of less than 0.05 mg/cm², and no visual signs of corrosion or staining.

[0027] The composition does not degrade polymers including elastomers and plastics. After 120h contact at 50°C, NBR, EPDM, PE, PP, PVC, POM, PBT specimens with a mass change of more than 0.4% were tested. The hardnesses of these specimens are also not modified in relation to a reference value (verification carried out on NBR elastomer material in particular) in accordance with the requirements of standards such as JIS K2398-2001 "Automotive windscreen cleaning agent". This standard specifies each technical requirement in more detail: exterior appearance, freezing point, pH value, high temperature stability, low temperature stability, detergency, compatibility with metal(s), rubber(s), plastic(s), coating(s), etc.

[0028] The composition also respects paints and surface coatings. After 24 hours of contact at 50°C, no visual modification (blistering, delamination,...) has been observed on epoxy, urethane or acrylic type paints.

[0029] The present invention thus concerns a non-flammable, volatile and aqueous composition comprising at least one compound A and optionally at least one compound selected from the group consisting of a compound B and a compound C, wherein :

• the compound A is at least one, optionally substituted, glycol ether, preferably a linear or branched, saturated or unsaturated, mono- or di- C2 to C5 glycol mono- or di- alkyl or aryl ether, in which the alkyl or aryl groups, identical or different, comprise from 1 to 6 carbon atoms;
• the compound B is at least one linear or branched, saturated or unsaturated, C1 to C4 alcohol; and
• the compound C is at least one linear or branched, saturated or unsaturated, C2 to C5 polyol and having no more than 3 hydroxyl functions.

[0030] According to a particular embodiment of the composition of the present invention, the alkyl groups are chosen in the group comprising methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl and hexyl.

[0031] According to a particular embodiment of a composition of the present invention, the aryl group is phenyl.

[0032] According to a particular embodiment of a composition of the present invention, the glycol ether(s) of the compound A are advantageously glycol ethers with a flash point equal or above 30°C, preferably above 60°C (to achieve the non-flammable feature of the end-use product), with a freezing point below -15°C (to guarantee use of the end-use product over a wide temperature range, namely by inhibiting ice formation or remaining its liquid state at temperature in the range from about -15°C to about -30°C), with a vapor pressure greater than 0.05 kPa at 20°C (to achieve quick drying of the end-use product) and/or having a molecular mass less than 150 g/mol (to ensure better stability and prevent freezing of the end-use product), but excluding all compounds categorized for reproductive toxicity according to GHS and CLP Regulation (EC) 1272/2008. Glycol ethers are amphiphilic solvents that are both soluble in water and fatty substances. This gives them useful properties for many technical and industrial uses, i.e. excellent cleaning and degreasing properties, with effectiveness on many waxes, oils and resins.

[0033] According to a particular embodiment of a composition of the present invention, the at least one glycol ether is chosen from glycol ethers derived from propylene oxide. For example, the at least one glycol ether is chosen from the group consisting of 2-Propylene Glycol 1-Methyl Ether (2PG1 ME or PGME), 2-Propylene Glycol 1-Methyl Ether Acetate (2PG1 MEA), Di-Propylene Glycol Methyl Ether (DPGME), Propylene Glycol Dimethyl Ether (PGDME), 2-Propylene Glycol 1-Ethyl Ether (2PG1EE), 2-Propylene Glycol 1-Ethyl Ether Acetate (2PG1 EEA), Propylene Glycol n-Propyl Ether (PGnPE), 2-Propylene Glycol 1-n-Butyl Ether (2PG1 BE), Propylene Glycol 1-tert-Butyl Ether (PG1tBE), Propylene Glycol Phenyl Ether (PGPhE), Di-Ethylene Glycol mono-Butyl Ether (DEGBE).

[0034] According to a particular embodiment of a composition of the present invention, the at least one glycol ether is chosen from glycol ethers derived from ethylene oxide. For example, the at least one glycol ether is chosen from the group consisting of Di-Ethylene Glycol Ethyl Ether (DEGEE), Ethylene Glycol n-Propyl Ether (EGnPE), Ethylene Glycol n-Propyl Ether Acetate (EGnPEA), Ethylene Glycol iso-Propyl Ether (EGiPE), Ethylene Glycol Hexyl Ether (EGHE), Ethylene Glycol Phenyl Ether (EGPhE), Ethylene Glycol n-Butyl Ether (EGBE), Ethylene Glycol tert-Butyl Ether (EGtBE).

[0035] According to a particular embodiment of a composition of the present invention, the at least one glycol ether is chosen from the alternative group consisting of Butylene Glycol Methyl Ether, Butylene Glycol di-Methyl Ether, Butylene Glycol Ethyl Ether, Butylene Glycol Propyl Ether, 3-Methyl 3-Methoxy Butanol (MMB).

[0036] Furthermore, some glycol ethers are known to form azeotropic compositions with water, i.e. forming a mixture which has, for a particular composition, a vapor phase having the same composition than the liquid phase with which it is in equilibrium. Known water-glycol azeotropes are called positive: their boiling temperature is lower than that of the pure components. This results in a higher vapour pressure than the pure components, which improves the volatility of the system. Among the glycol ethers listed above, the following may be cited as positive azeotropic glycol ethers: 2-Propylene Glycol 1-Methyl Ether (2PG1ME), 2-Propylene Glycol 1-Methyl Ether Acetate (2PG1MEA), Di-Propylene Glycol Methyl Ether (DPGME), Ethylene Glycol Hexyl Ether (EGHE), Butyl Ethoxy Ethanol (BEE). The preferred azeotropic glycol ether is 2-Propylene Glycol 1-Methyl Ether (2PG1ME or PGME), available from Dow Chemical under the trade name Dowanol^® PM. The optimum content is in the concentration range from 30 to50% by weight of the composition of the invention.

[0037] Other glycol ethers may be additionally incorporated to adjust evaporation rate and cleaning performance. According to a particular embodiment of a composition of the present invention, the compound A is a mixture of a compound A1 which is the 2-Propylene Glycol 1-Methyl Ether (2PG1 ME), and a compound A2 which is at least one among the 3-Methyl 3-Methoxy Butanol (MMB)and the Propylene Glycol Propyl Ether, preferably in a mass ratio compound A1:compound A2 in the range from 1:1 to 3:1. In a preferred embodiment, the glycol ether mixture comprises or consists of 2-Propylene Glycol 1-Methyl Ether and 3-Methyl 3-Methoxy Butanol.

[0038] According to a particular embodiment of a composition of the present invention, the at least one linear or branched, saturated or unsaturated, C1 to C4 alcohol of compound B has a vapor pressure greater than 2.3 kPa at 20°C, in order to promote volatility of the composition by a drag-out effect (water being the main phase of the composition). For example, at least one linear or branched, saturated or unsaturated, C1 to C4 alcohol is chosen from the group consisting of ethanol, 1-propanol, isopropanol, and tert-butanol. The use of short-chain solvents reduces the surface tension of the composition and allows it to better wet the surfaces and dirt. Advantageously, the use of compound B in the invention may not exceed 15% by weight of the total glycol ether content, more preferably may not exceed 5% by weight of the total glycol ether content.

[0039] According to a particular embodiment of a composition of the present invention, the at least one linear or branched, saturated or unsaturated, C2 to C5 polyol and having no more than 3 hydroxyl functions of compound C is chosen from the group consisting of Ethylene Glycol, Diethylene Glycol, Triethylene Glycol, Propylene Glycol, Trimethylene Glycol, n-Butylene glycol, 2,3-Butylene glycol, Neopentyl Glycol, Glycerol. Thanks to their hygroscopic properties, the polyols in the composition also act as humectants, facilitating the cleaning of dried-out dirt. As these polyols have the particularity of having a very low vapor pressure generating residues which never dry, it has been found that a content of less than 15% by weight of the total glycol ether content is preferred in order to guarantee better drying behaviour. Preferably, the mass ratio of compound C to compound A does not exceed 1:20, more preferably does not exceed 1:25. Preferably, the mass ratio of compound C to compound B is 1:1.

[0040] Advantageously, the 2-Propylene Glycol 1-Methyl Ether of the composition of present invention cooperates with monohydroxy alcohol on the one hand to reduce the freezing point. On the other hand, due to its higher viscosity than that of monohydroxy alcohol, and its lower volatility, it adsorbs on the glass surface, increases the dwell time and therefore enhances the effect of washing or dirt removal. At the same time, it contributes to the reduction of the friction between the wiper and the glass.

[0041] According to a particular embodiment, a composition of the present invention comprises:

• the compound A in a concentration superior or equal to 10 wt% and inferior or equal to 50 wt%, 10 wt% ≤ [compound A] ≤ 50 wt%;
• the compound B in a concentration strictly superior to 0 wt% and inferior or equal to 15 wt%, 0 wt% < [compound B] ≤ 15 wt%; and
• the compound C in a concentration strictly superior to 0 wt% and inferior or equal to 15 wt%, 0 wt% < [compound C] ≤ 15 wt%;

the wt% being based on a total weight of the composition.

[0042] According to a particular embodiment, a composition of the present invention comprises:

• the compound A in a concentration superior or equal to 20 wt% and inferior or equal to 50 wt%, 20 wt% ≤ [compound A] ≤ 50 wt%;
• the compound B in a concentration superior or equal to 0.1 wt% and inferior equal to 5 wt%, 0.1 wt% ≤ [compound B] ≤ 5 wt%; and
• the compound C in a concentration superior or equal to 0.1 wt% and inferior or equal to 5 wt%, 0.1 wt% ≤ [compound C] ≤ 5 wt%;
• water in a concentration superior or equal to 40 wt% and inferior or equal to 70 wt%, 40 wt% ≤ [water] ≤ 70 wt%;

the wt% being based on a total weight of the composition.

[0043] According to a particular embodiment of a composition of the present invention, the mass ratio compound B and/or compound C:compound A is in the range of 1:90 to 1:9.

[0044] According to a particular embodiment, a composition of the present invention further comprises at least one surfactant which is anionic, non-ionic, amphoteric or a mixture thereof, chosen from the group consisting of ethers of the carboxylic acids, alkyl aryl sulfonates containing an alkyl radical of from 8 to 16 carbon atoms and no substituent other than alkyl, alkyl ether sulfates containing an alkyl radical of from 8 to 18 carbon atoms and no substituent other than alkyl with different degrees of ethoxylation (average number of ethoxylation moles between 0.5 to 5), alkyl sulfates containing an alkyl radical of from 12 to 18 carbon atoms and no substituent other than alkyl, alcohols containing an alkyl radical of from 12 to 18 carbon atoms and no substituent other than alkyl with different degrees of ethoxylation (average number of ethoxylation moles between 3 to 20), N-alkylamine oxides containing an alkyl radical of from 12 to 18 carbon atoms and no substituent other than alkyl, sophorolipides.

[0045] According to a particular embodiment, a composition of the present invention further comprises a cationic surfactant such as a copolymer of polydimethylsiloxane and organic quaternary amine which is responsible for the spontaneous cracking of the water layer to enhance the drying effect and improve the water repellency of the cleaned surfaces. Copolymer of polydimethysiloxane and organic quaternary amine is available for example from EVONIK Industries AG under the trade name Tegropren^® 6922.

[0046] Preferably said surfactant is used in a concentration superior or equal to 0.001 wt% and inferior or equal to 0.1 wt%, 0.001 wt% ≤ [surfactant] ≤ 0.1 wt%, the wt% being based on the total weight of the composition.

[0047] Anionic, cationic, non-ionic, amphoteric surfactants improve cleaning or soil removal properties.

[0048] The use of surfactant may be helpful in removing or repelling insects from surfaces. It is assumed that the synergistic effect of the glycol ether / surfactant combination is due to the sticky and film-forming effect of the surfactant which improves the contact of the end-use product with the insect and enhances the ability of surfactants to dewax the insect's protective coating. The insect becomes dehydrated or is easily attacked by ever-present environmental microbes. The insect repellent activity is prolonged over time for example due to the use of biosurfactant such as a sophorolipid which resists repeated rinsing.

[0049] According to a particular embodiment, a composition of the present invention may also comprise an insect repellent such as octanoic, nonanoic or decanoic acid, or citronella oil, geraniol, cedar oil and similar. The present invention also concerns the use of a composition of the present invention, in a liquid cleaning composition.

[0050] According to a particular embodiment of the invention, the composition is used as a cleaning composition for cleaning metal. According to another particular embodiment of the invention, the composition is intended to improve the wetting by water of the surface to which the product is applied. Preferably, the surface is a glass surface such as a window. In a preferred embodiment, the composition is used for washing vehicle windscreens. The detergent is contained in the tank provided for this purpose, and is administered via the dispensing nozzles. According to another embodiment, the cleaner is dispensed in a spray-aerosol can, after pressurization by a non-flammable gas. Another embodiment is the provision of the product by a hand sprayer.

Brief description of the figures

[0051] Figure 1 represents the aqueous cryoscopic constant (relationship between the freezing point and molality of the solute) for different compositions with (in circles) or without (in squares) propylene glycol methyl ether (PGME).

EXAMPLES

EXAMPLE 1 : DETERMINATION OF THE PROPERTIES OF THE COMPOUNDS OF THE INVENTION TAKEN INDEPENDENTLY AND OF COMPARATIVE COMPOUNDS

Material and Methods

[0052] Flash point measurement was based on closed cup Pensky-Martens measurement according to the ASTM D93 method (and on Setaflash apparatus according to the ASTM D3278 method).

[0053] Freezing points measurements were performed according to standards NF T 78-102 and ASTM D1177. The result is approximated to the nearest unit. For purposes of the examples in Table 1, 2 and 3, acceptable result was a freezing point less than or equal to -15°C.

[0054] The drying speed was evaluated comparatively from the evaporation time of 1 drop of detergent composition deposited on a glass plate, placed in a non-ventilated oven maintained at 25°C. The results were scored according to the following rating scale namely that ○ : evaporation time less than or equal to 2 hours; ∅: evaporation time between 2 and 4 hours; ⊗: evaporation time between 4 and 6 hours; × evaporation time greater than 6 hours. For purposes of the examples in Table 1, 2 and 3, acceptable result was an evaporation time less than or equal to 2 hours.

[0055] At the end of this test, the residual traces were estimated by visual observation of the glass plate in transparency. The results were scored according to the following rating scale namely that ○: no traces; ∅: light traces not hindering observation; ⊗: traces hindering observation. For purposes of the examples in Table 1, acceptable result was no traces.

[0056] The dirt of the cleaning test was a 200g/L dispersion of various dusts within a low viscous API Group I mineral oil. 1mL of this dispersion was applied to a glass surface and left in contact for 24 hours at 100°C, causing a slight varnishing. The test itself consisted of applying 1mL of the product to be studied for 10s, then wiping with a single stroke of the cloth. This cleaning operation was repeated twice. The result was scored after visual inspection of the transparency of the glass surface according to the following rating scale namely that ○: no traces; ∅: light traces that do not hinder observation; ⊗: traces that hinder observation. For purposes of the examples in Table 1, acceptable result was no traces.

Results

[0057] In table 1, the comparative commercial example was made of a cleaning composition containing 30% by weight of ethanol in aqueous medium, in the presence of ionic and anionic surfactants. The properties of conventional solvents that partially address the issue were also reported.

Table 1

Compound		A1	A2	B	C	Other conventional solvents
Composition	Comparative commercial example	PGME	MMB	Ethanol	Ethylene glycol	Water	Exxsol D100	CFC-113
Flash point (°C)	15	31	68	13	111	-	67	N/A
Freezing point (°C)	-20	-96	< -50	-114	-13	0	-49	-35
Drying speed	○	○	⊗	○	x	⊗	x	○
Residual traces	∅	○	∅	○	⊗	○	∅	○
Cleaning	∅	○	○	○	∅	⊗	○	○
Classification and labelling according to CLP regulation (EC) 1272/2008	H226	H336	H319	H225	H302	-	H304	H420
Theoretical PVap at 20°C (Pa)	2800	1560	90	5800	7	2300	40	36200

[0058] On reading the results, it can be seen that, taken independently, the performance of each example of compounds of the invention did not make it possible to simultaneously obtain a flash point greater than 60°C, a freezing point less than or equal to -20°C and an acceptable drying speed. Conventional solvents did not satisfy all the criteria either, except for hydrohalogenated solvents of the CFC-113 type. However, the latter are unusable due to their high environmental impact. The water-based commercial comparative example presented acceptable performances in cleaning, but the presence in high concentration of ethanol implies a characteristic of particularly low and unsuitable flash point.

[0059] The freezing point is the temperature at which crystallization begins in the absence of supercooling, or the maximum temperature reached immediately after initial crystal formation in the case of supercooling. The law of aqueous cryometry stipulates that the depression of the freezing point of a system is proportional to the molality b of the solute.

[0060] According to the Figure 1, surprisingly, the compositions of the present invention containing a majority proportion of compound A1 (in the range of 15 to 40% by weight on the total weight of the composition) such as a propylene glycol methyl ether (PGME) which provides an azeotropic behaviour with water demonstrate a lower measured cryoscopic constant around -2.8 K/b (in circles) compared to the cryoscopic constant measured for the compositions which do not contain it (in squares). This means that to achieve the same freezing point target, the concentration required of compound A1 will be lower. This positively impacts the volatility.

[0061] At the same time, the azeotropic compositions Water - Compound A1 generated vapor pressures almost 30% higher than the theoretical vapor pressure calculated according to Raoult's law. For example, a 40% by weight solution of propylene glycol methyl ether (PGME) has a vapor pressure measured according to the ASTM D2879 method of 2.9kPa at 20°C, instead of about 2.2kPa theoretically.

EXEMPLE 2: DETERMINATION OF THE ADVANTAGEOUS PROPERTIES OF A COMPOSITION OF THE INVENTION AND OF COMPARATIVE COMPOSITIONS

[0062] Table 2 shows the results of the properties obtained with a suitable combination of components (A1), (A2), (B) and (C) (Ex. 1 to 4) of the invention, while comparative examples (Ex. Comp. 1 to 9) show the results obtained with the components taken independently.

[0063] By "A1" was meant a glycol ether with azeotropic behaviour, preferably propylene glycol methyl ether (PGME).

[0064] By "A2" was meant one or more glycol ethers which do not behave azeotropically with water, preferably 3-Methyl 3-Methoxy Butanol (MMB), Propylene Glycol Propyl Ether or any combination thereof.

[0065] By "B" was meant a polar solvent with less than 4 carbon atoms, preferably ethanol

[0066] By "C" was meant a polyol with less than 5 carbon atoms, preferably ethylene glycol (EG).

[0067] In the following compositions, the complement was provided by water and minor elements (surfactants,...).

Table 2

Composition	Ex. Comp. 1	Ex. Comp. 2	Ex. 1	Ex. 2	Ex. Comp. 3	Ex. Comp. 4	Ex. 3	Ex. Comp. 5	Ex. Comp. 6
Total glycol ether content (%m)	30	30	35	35	40	40	40	50	50
Ratio A1/A2 (%)	100/0	67/33	100/0	50/50	100/0	90/10	50/50	60/40	40/60
Freezing point (°C)	-13	-13	-17	-15	-23	-20	-15	-21	-18
Flash point (°C)	62.5	62	61.5	61	59	52	62	59	62.5
Drying speed	○	○	○	○	○	○	○	∅	⊗

[0068] No composition with less than 35% glycol ethers met the freezing point criteria, even if only an azeotropic glycol ether was used. In combination with other glycol ethers, a minimum content of 20% by weight of compound A1 on the total formulation was required to reach -15°C. In combination with other glycol ethers, a minimum content of 30% by weight of compound A1 on the total formulation was required to reach -20°C.

[0069] The maximum glycol ether content may not exceed 50% by weight of the total formulation. Above this limit, combinations of compounds A1 and A2 may either lead to an increase in freezing point and a decrease in drying kinetics if there is an excess of compound A2, or to a flammable product if there is an excess of compound A1.

[0070] Table 3 below shows the results of adding ethylene glycol as a freezing point depressant. Although ethanol can also play this role, its action on lowering the flash point made it difficult to use in large proportions. It was preferable to play on the compound A1/A2 ratio, the azeotropic glycol ether being favourable to freezing point depression.

[0071] The combined effect of compounds B and C in similar proportions advantageously made it possible to increase the freezing point depression and the flash point, while improving the evaporation properties.

Table 3

Composition	Ex. Comp. 6	Ex. Comp. 7	Ex. Comp. 8	Ex. Comp. 9	Ex. 4
Total glycol ether content (%m)	50	50	50	45	45
Ratio A1/A2 (%)	40/60	40/60	40/60	75/25	75/25
Ratio A/B/C (%)	100/0/0	97/0/3	97/3/0	95/0/5	90/5/5
Freezing point (°C)	-18	-19	-19	-23	-24
Flash point (°C)	62.5	62.5	57.5	61.5	61
Drying speed	⊗	⊗	∅	⊗	○

List of references

[0072] 

1.

Patent EP0443911

2.

Patent EP0347924

3.

Patent Application US2031145

4.

Patent US9,085,751

5.

Patent US8,845,817

6.

Patent US9,879,204

7.

International Application WO2017/011216

8.

Patent US8,114,223

9.

Patent US5,486,314

10.

International Application WO94/03579

Claims

1. Non-flammable, volatile and aqueous composition comprising at least one compound A and optionally at least one compound selected from the group consisting of a compound B and a compound C, wherein :

- the compound A is at least one, optionally substituted, glycol ether, preferably a linear or branched, saturated or unsaturated, mono- or di- C2 to C5 glycol mono- or di- alkyl or aryl ether, in which the alkyl or aryl groups, identical or different, comprise from 1 to 6 carbon atoms;

- the compound B is at least one linear or branched, saturated or unsaturated, C1 to C4 alcohol; and/or

- the compound C is at least one linear or branched, saturated or unsaturated, C2 to C5 polyol and having no more than 3 hydroxyl functions.

2. Composition according to claim 1, wherein the composition is in liquid state at any temperature in the range from about -15°C to about -30°C.

3. Composition according to either of claims 1 or 2, wherein the alkyl groups are chosen in the group comprising methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl and hexyl.

4. Composition according to either of claims 1 or 2, wherein the aryl group is phenyl.

5. Composition according to any one of claims 1 to 4, wherein the at least one glycol ether is chosen from P-series glycol ethers, preferably from P-series glycol ethers having a molecular mass less than 150g/mol.

6. Composition according to claim 5, wherein the at least one glycol ether is chosen from the group consisting of: 2-Propylene Glycol 1-Methyl Ether (2PG1ME), 2-Propylene Glycol 1-Methyl Ether Acetate (2PG1MEA), Di-Propylene Glycol Methyl Ether (DPGME), Propylene Glycol Dimethyl Ether (PGDME), 2-Propylene Glycol 1-Ethyl Ether (2PG1EE), 2-Propylene Glycol 1-Ethyl Ether Acetate (2PG1EEA), Propylene Glycol n-Propyl Ether (PGnPE), 2-Propylene Glycol 1-n-Butyl Ether (2PG1BE), Propylene Glycol 1-tert-Butyl Ether (PG1tBE), Propylene Glycol Phenyl Ether (PGPhE), Di-Ethylene Glycol mono-Butyl Ether (DEGBE).

7. Composition according to any one of claims 1 to 4, wherein the at least one glycol ether is chosen from E-series glycol ethers.

8. Composition according to claim 7, wherein the at least one glycol ether is chosen from the group consisting of: Di-Ethylene Glycol Ethyl Ether (DEGEE), Ethylene Glycol n-Propyl Ether (EGnPE), Ethylene Glycol n-Propyl Ether Acetate (EGnPEA), Ethylene Glycol iso-Propyl Ether (EGiPE), Ethylene Glycol Hexyl Ether (EGHE), Ethylene Glycol Phenyl Ether (EGPhE), Ethylene Glycol n-Butyl Ether (EGBE), Ethylene Glycol tert-Butyl Ether (EGtBE).

9. Composition according to any one of claims 1 to 4, wherein the at least one glycol ether is chosen from the group consisting of: Butylene Glycol Methyl Ether, Butylene Glycol di-Methyl Ether, Butylene Glycol Ethyl Ether, Butylene Glycol Propyl Ether, 3-Methyl 3-Methoxy Butanol (MMB).

10. Composition according to any one of claims 1 to 4, wherein the at least one glycol ether is chosen from the group consisting of: 2-Propylene Glycol 1-Methyl Ether (2PG1ME), 2-Propylene Glycol 1-Methyl Ether Acetate (2PG1MEA), Di-Propylene Glycol Methyl Ether (DPGME), Ethylene Glycol Hexyl Ether (EGHE), Butyl Ethoxy Ethanol (BEE).

11. Composition according to either of claims 1 or 2, wherein the compound A is a mixture of a compound A1 which is the Propylene Glycol Methyl Ether, and a compound A2 which is at least one among the 3-Methyl 3-Methoxy Butanol (MMB) and the propylene Glycol Propyl Ether, preferably in a ratio compound A1 :compound A2 of 3:1.

12. Composition according to any one of claims 1 to 11, comprising :

- the compound A in a concentration superior or equal to 10wt% and inferior or equal to 50wt%, 10wt% ≤ [compound A] ≤ 50wt%;

- the compound B in a concentration strictly superior to 0wt% and inferior or equal to 15wt%, 0wt% < [compound B] ≤ 15wt%; and

- the compound C in a concentration strictly superior to 0wt% and inferior or equal to 15wt%, 0 wt% < [compound C] ≤ 15 wt%;

the wt% being based on a total weight of the composition.

13. Composition according to claim 12, comprising :

- the compound A in a concentration superior or equal to 20wt% and inferior or equal to 50wt%, 20wt% ≤ [compound A] ≤ 50wt%;

- the compound B in a concentration superior or equal to 0.1 wt% and inferior equal to 5wt%, 0.1 wt% ≤ [compound B] ≤ 5wt%; and

- the compound C in a concentration superior or equal to 0.wt% and inferior or equal to 5wt%, 0.1 wt% ≤ [compound C] ≤ 5wt%;

- water in a concentration wt% superior or equal to 40wt% and inferior or equal to 70wt%, 40wt% ≤ [water] ≤ 70wt%;

the wt% being based on a total weight of the composition.

14. Composition according to any one of claims 1 to 13, wherein the mass ratio compound B and/or compound C:compound A is in the range of 1:90 to 1:9.

15. Composition according to any one of claims 1 to 14, further comprising at least one surfactant which is anionic, amphoteric, nonionic, cationic or a mixture thereof, preferably in a concentration superior or equal to 0.001wt% and inferior or equal to 0.1wt%, 0.001 wt% ≤ [surfactant] ≤ 0.1wt%, the wt% being based on the total weight of the composition.

16. Use of a composition according to any one of claims 1 to 15, in a liquid cleaning composition.

Drawing