Patent Application
20250043062
The present invention refers to a composition comprising or, alternatively, consisting of isocyanates blocked by means of a blocking agent selected from the group consisting of (i)-(iv) and, optionally, one or more technological additives.
Furthermore, the present invention refers to a use of (i)-(iv) as an isocyanate blocking agent.
Furthermore, the present invention refers to a use of a composition comprising or, alternatively, consisting of isocyanates blocked by means of a blocking agent; and optionally one or more technological additives; wherein said blocking agent is at least one imidazole compound of general formula (I), in a water repellency and/or oil repellency treatment of a fabric or of a skin.
Furthermore, the present invention refers to a use of an imidazole compound of general formula (I) as a blocked isocyanate blocking agent in a water repellency and/or oil repellency treatment of a fabric or a skin.
Methyl ethyl ketoxime (or 2-butanone oxime, CAS No. 96-29-7; in short, “MEKO”) is a colourless liquid that is the oxime derived from methyl ethyl ketone. MEKO is mainly used as an anti-skinning agent for oil and latex paints and coatings, as it is able to prevent the formation of solid skins above said paints and said coatings. The functioning of MEKO takes place through a bond with drying agents (in particular metal salts) that catalyze the oxidative cross-linking of the oils contained in the paints and in coatings. Once the paint or the coating is applied to a surface, MEKO evaporates, thus allowing the drying process to proceed.
MEKO is also widely used as an isocyanate blocking agent in automobile electrodeposition coating, in painting works, as a curing agent for silicone rubber due to its outstanding water and heat resistance, in fabric treatment in combination with a non-fluorinated resin due to the water repellency properties or in combination with a fluorinated resin due to the water repellency and/or oil repellency properties, and in the printing industry as a fixative.
However, MEKO presents several significant hazards to human health. It has in fact been the subject of the evaluation process (SEv; Substance Evaluation process) whose outcome, reported in the Substance Evaluation Report, led to the drafting of a proposal for harmonized classification (CLH) for the substance.
On the basis of this proposal, ECHA's Risk Assessment Committee (RAC) in September 2018 adopted the opinion to classify MEKO as Carc. 1B, H350: may cause cancer.
The same process has also led to the attribution of the following hazards: Acute Tox. 3, H301: toxic if swallowed; Acute Tox. 4, H312: harmful in contact with skin; Skin Sens. 1, H317-may cause an allergic skin reaction. 1, H318: Causes serious eye damage; Skin Irrit. 2, H315: causes skin irritation; STOT SE 3, H336: may cause drowsiness or dizziness; STOT SE 1, H370 (upper respiratory tract): causes organ damage; and STOT RE 2, H373 (blood system): may cause organ damage in case of prolonged or repeated exposure.
The corresponding inclusion in Annex VI of Regulation (EC) No. 1272/2008 (CLP) entered into force with the 15th ATP in August 2020. As of March 2022, the obligation of classification and labelling as Carc. 1B (H350) for mixtures containing the substance MEKO in concentrations exceeding 0.1% will therefore come into force.
Prior art document JPH05179573A concerns a water repellent and oil repellent agent. Prior art document CN110981750A discloses a method for synthesizing 2-pentanone oxime by means of an ammoxidation reaction.
The Applicant, after a long and intense research and development activity, has identified some oximes that might be used as an alternative to MEKO and that could provide an adequate response to the existing limitations, drawbacks and problems.
In particular, the compounds identified in the present invention have significantly lower toxicity characteristics than MEKO, are normally available on the market in large quantities and at acceptable costs even if-at least currently-they are higher than those of MEKO, are capable of generating blocked isocyanates with neutral (i.e. tending to white or light yellow) colourations, have reaction kinetics comparable to the corresponding products blocked by means of MEKO and show similar and in some cases superior properties compared to those currently used.
Therefore, the object of the present invention is a composition comprising or, alternatively, consisting of isocyanates blocked by means of a blocking agent selected from the group consisting of (i)-(iv) and, optionally, one or more technological additives, having the characteristics as defined in the attached claims.
Further, the object of the present invention is a use of a blocking agent selected from the group consisting of (i)-(iv) as an isocyanate blocking agent, having the characteristics as defined in the attached claims.
Furthermore, the present invention refers to a use of a composition comprising or, alternatively, consisting of isocyanates blocked by means of a blocking agent; and optionally one or more technological additives; wherein said blocking agent is at least one imidazole compound of general formula (I), in a water repellency and/or oil repellency treatment of a fabric or of a skin, having the characteristics as defined in the attached claims.
Furthermore, the present invention refers to a use of an imidazole compound of general formula (I) as blocked isocyanate blocking agent in a water repellency and/or oil repellency treatment of a fabric or skin, having the characteristics as defined in the attached claims.
Preferred embodiments of the present invention will be described hereinafter by way of example, and therefore not by way of limitation with the aid of the tables, in which:
Therefore, an object of the present invention is a composition comprising or, alternatively, consisting of:
Within the present description, the term “blocked isocyanates” means the reaction products between an isocyanate and said blocking agent, such that at least one isocyanate function is blocked (non-reactive).
Preferably, said 2-pentanone oxime is not obtained by means of an ammoxidation reaction.
More preferably, said mixture (iv) comprises (iii) 5-methyl-3-heptanone oxime in combination with:
Preferably, in said mixture (iv):
Said isocyanates are preferably selected from the group consisting of:
Preferably, said (d) polyisocyanates derived from isophorone diisocyanate (IPDI) obtained by trimerization, biuretization and/or allophanation process(es) comprise or, alternatively, consist of oligomerization products of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate and butane-1-ol and 25 pentane-1-ol and 2-ethylhexane-1-ol, of allophanate type.
More preferably, said (d) comprise the product EC/List no.: 933-047-9, comprising or consisting of the mixture of compounds illustrated in the following general formula (II):
Said isocyanates—are more preferably selected from the group consisting of:
Said composition comprising or, alternatively, consisting of blocked isocyanates and optionally one or more technological additives is preferably a non-ionic and/or ionic aqueous suspension or dispersion.
To make said compositions stable in the form of aqueous dispersions of said blocked isocyanates it is possible to insert into the molecule a carboxylated ionic group (for example deriving from dimethylolpropionic acid) or an alkoxylated chain having mono-alcoholic functionality (for example polyethylene glycol mono methyl ether with molecular weight of 350, 500 or 750 amu). More preferably, said suspension or dispersion comprises a mixture of water and co-solvents, preferably in a weight ratio comprised from 2% to 50% and preferably from 5% to 20%.
By way of example only, said co-solvents are selected from the group consisting of propylene glycol dimethyl ether, acetone or other low boiling organic solvent.
Said composition is preferably free of methyl ethyl ketoxime (MEKO).
Furthermore, the object of the present invention is a use of:
Preferably, said mixture (iv) comprises (iii) 5-methyl-3-heptanone oxime in combination with:
Preferably, in said mixture (iv):
Furthermore, the subject-matter of the present invention is a use of an imidazole compound of the following general formula (I):
Preferably, said imidazole compound is 2-isopropyl-1H-imidazole (CAS No. 36947-68-9) or 2-ethyl-4-methylimidazole (CAS No. 931-36-2).
More preferably, said imidazole compound is 2-ethyl-4-methylimidazole.
Preferably, said use comprises a deblocking of said isocyanates by said blocking agent in a water repellency and/or oil repellency treatment of a fabric or of a skin.
Furthermore, the object of the present invention is a use of a composition comprising or, alternatively, consisting of:
In this description the expression “at least one imidazole compound” means that said composition may comprise a single imidazole compound of general formula (I), or a mixture of two or more imidazole compounds of general formula (I) having R1 and/or R2 different from each other.
Preferably, said imidazole compound or an imidazole compound of said mixture is 2-isopropyl-1H-imidazole (CAS No. 36947-68-9) or 2-ethyl-4-methylimidazole (CAS No. 931-36-2). More preferably, said composition comprises a mixture of 2-isopropyl-1H-imidazole and 2-ethyl-4-methylimidazole.
Even more preferably, said imidazole compound or an imidazole compound of said mixture is 2-ethyl-4-methylimidazole.
Said blocked isocyanates-ionic or non-ionic-are preferably selected from the group consisting of:
Said composition is preferably an aqueous suspension or dispersion.
More preferably, said composition is free of methyl ethyl ketoxime (MEKO).
Said composition preferably comprises acrylic acid or methacrylic acid esters (in short: polyacrylates) functionalized with fluorinated chains.
More preferably, said polyacrylates are obtained by means of a copolymerization of the following monomer units (a)-(d):
Rf-Rh-OCOC(R5)═CH2
Rz-OCOC(R5)═CH2 (II)
Ry-OCOC(R5)═CH2
Rz-OCOC(R5)═CH2
Said composition further comprises at least one further ingredient selected from paraffin wax and polysiloxane compounds.
Below will be reported some examples, provided by way of non-limiting example, of the present invention.
The imidazole compounds 2-isopropyl-1H-imidazole (CAS No. 36947-68-9) and 2-ethyl-4-methylimidazole (CAS No. 931-36-2) were reacted with the following commercially available isocyanates:
A DSC (Differential scanning calorimetry) study was performed on the blocked isocyanates to determine the deblocking temperatures thereof. The instrument used is Discovery DSC25AUTO TA INSTRUMENTS (WATERS CORPORATIONS) Serial No. DSC2A-01063.
The proposed DSC method consists of preparing the blocked isocyanates in a nitrogen atmosphere and then performing the following temperature ramps:
The results are illustrated in Table 1 below.
Exemplary DSC spectra are reported in the following
In general, the reactions between isocyanates and imidazoles result in good reaction kinetics, and the deblocking temperature for both imidazoles tested is comprised in the range from 89.9° C. to 98° C.
As regards the appearance of the blocked isocyanates, the products resulting from the reactions between:
The three oximes (i), (ii), (iii) subject-matter of the present invention have been individually reacted with the commercial isocyanates discussed above:
The aforementioned DSC study (Differential scanning calorimetry) was performed on the blocked isocyanates to determine the deblocking temperatures thereof.
The results are illustrated in Table 2 below.
Exemplary DSC spectra are reported in the following
In all the products obtained, the colouration was white. The reactivity of all oximes with both isocyanates tested is high.
From the above data it emerges that the three oximes (i), (ii), (iii) have very promising characteristics to be used as blocking agents in isocyanates due to their classification, reactivity, and due to the colouration of the final products obtained.
The temperature values in Table 2 suggest that the three oximes (i), (ii), (iii) may also be used in combination in a single composition to modulate the deblocking temperatures as a function of contingencies, so as to allow flexibility necessary to optimize the processes of use of such compositions.
Furthermore, as can be noted, the deblocking temperatures are not particularly high. This aspect is particularly important with a view of optimizing energy consumption and improving process productivity.
The tests discussed above were repeated by blocking other isocyanate products with oximes (i), (ii), (iii). The isocyanate products are as follows:
Said DSC study was performed on the obtained blocked isocyanates to determine the deblocking temperatures thereof.
The results were included in Table 3 below.
In all the products obtained, the colouration was white. The reactivity of all oximes with both isocyanates tested is high.
The results obtained are in line with the first series of tests.
It should be noted that the tests carried out on bio-based PDI reveal relatively low deblocking temperatures, with important consequences with a view to optimizing energy consumption and improving process productivity. With the same isocyanate, lower deblocking temperatures are achieved by increasing the chain length of the oxime blocking agent.
The general preparation procedure consists in reacting at about 80° C. under stirring a polyisocyanate with a methoxy polyethylene glycol. The latter additive is fundamental for subsequently dispersing the product in water. The product obtained is partially blocked with a blocking agent under stirring at a temperature of about 70° C. The remaining free NCO groups are reacted at about 70° C. with a bifunctional compound diglycol and/or diamine to increase the molecular weight thereof. The reaction mixture is then cooled to 50° C. and then water is added under stirring up to a concentration of ca. 40%.
Methodologies for making compositions that are aqueous suspensions or dispersions of ionic or non-ionic blocked isocyanates are reported below. The following were used as blocking agents:
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
The reaction temperature is brought to 80° C. and maintained for about one hour until the determination of the free NCO groups still present by titration gives a value of 17.4% by weight.
It is then cooled to 70° C. to add dropwise in 20 minutes 31.4 g (0.310 eq) of 2-pentanone oxime keeping the mixture in a temperature range comprised from 70° C. to 75° C. After 15 minutes of reaction, the progress is checked by titration until the determination of the free NCO groups still present gives a value of 5.4%.
It is proceeded with the addition of 17.6 g (0.182 eq) of tetraethylene glycol in 20 minutes. After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis. It is then cooled to about 50° C., to add 252.6 g of demineralised water under stirring.
A stable milky dispersion is obtained, with a solids content of 38.2% by weight.
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
The reaction temperature is brought to 80° C. and maintained for about one hour until the determination of the free NCO groups still present by titration gives a value of 17.4% by weight.
It is then cooled to 70° C. to add dropwise in 20 minutes 35.7 g (0.310 eq) of 4-methylpentane-2-one oxime with a temperature range comprised from 70° C. to 75° C. After 15 minutes of reaction, it is checked by titration that the determination of the free NCO groups still present gives a value of 5.4%.
It is proceeded with the addition of 17.6 g (0.182 eq) of tetraethylene glycol in 20 minutes. After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis. It is then cooled to about 50° C., to add 259.1 g of demineralised water under stirring.
A stable milky dispersion is obtained, with a solid content of 37.7% by weight.
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
The reaction temperature is brought to 80° C. and maintained for about one hour until the determination of the free NCO groups still present by titration gives a value of 17.4% by weight.
It is then cooled to 70° C. to add dropwise in 20 minutes 44.4 g (0.310 eq) of 5-methyl-3-heptanone oxime with a temperature range comprised from 70° C. to 75° C. After 15 minutes of reaction, it is checked by titration that the determination of the free NCO groups still present gives a value of 5.4%.
It is proceeded with the addition of 17.6 g (0.182 eq) of tetraethylene glycol in 20 minutes. After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis. It is then cooled to about 50° C., to add 272.1 g of demineralised water under stirring.
A stable milky dispersion is obtained, with a solid content of 37.7% by weight.
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
The reaction temperature is brought to 80° C. and maintained for about one hour until the determination of the free NCO groups still present by titration gives a value of 17.4% by weight.
It is then cooled to 70° C. to add dropwise in 30 minutes with a temperature range comprised from 70° C. to 75° C.:
It is specified that the addition of the different oximes could also take place in a different order from that indicated.
After 15 minutes of reaction, it is checked by titration that the determination of the free NCO groups still present gives a value of 5.4%.
It is proceeded with the addition of 17.6 g (0.182 eq) of tetraethylene glycol in 20 minutes. After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis. It is subsequently cooled to about 50° C., to add 261.4 g of demineralised water under stirring.
A stable milky dispersion is obtained, with a solid content of 39.6% by weight.
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
70.0 g (0.22013 eq) of Polurgreen AD 01, having an NCO content of 13.2%, 75% by weight;
The reaction temperature is brought to 70° C. and kept in a range comprised from 70° C. to 75° C. for about two hours, until the determination of the free NCO groups still present gives a value of 6.7% by weight.
Subsequently, 15.34 g (0.1761 eq) of MEKO is dripped over a period of about 1 hour taking care that the reaction temperature does not exceed 70° C.
After 1 hour of reaction it is checked by FTIR analysis that the prepolymer has the last traces (0.145%) of NCO groups and, at about 60° C., 0.392 g (0.02 eq) of dimethyl ethanol amine is added.
After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis and, at about 50° C., a mixture formed by 150.86 g of demineralised water and 0.604 g of 70% methanesulphonic acid is added in water. The organic solvent (ethyl acetate) is distilled off under vacuum.
A stable milky dispersion is obtained, with a solids content of 40.5% by weight.
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
The reaction temperature is brought to 70° C. and kept in a range comprised from 70° C. to 75° C. for about two hours, until the determination of the free NCO groups still present gives a value of 6.7% by weight.
Subsequently, 17.81 g (0.1761 eq) of 2-pentanone oxime is dripped over a period of about 1 hour, taking care that the reaction temperature does not exceed 70° C.
After 1 hour of reaction it is checked by FTIR analysis that the prepolymer has the last traces (0.142%) of NCO groups and, at about 60° C., 0.392 g (0.02 eq) of dimethyl ethanol amine is added.
After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis and, at about 50° C., a mixture formed by 163.85 g of demineralised water and 0.604 g of 70% methanesulphonic acid is added in water. The organic solvent (ethyl acetate) is distilled off under vacuum.
A stable milky dispersion is obtained, with a solids content of 40.3% by weight.
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
The reaction temperature is brought to 70° C. and kept in a range comprised from 70° C. to 75° C. for about two hours, until the determination of the free NCO groups still present gives a value of 6.7% by weight.
Subsequently, 20.28 g (0.1761 eq) of 4-methylpentane-2-one oxime is dripped over a period of about 1 hour, taking care that the reaction temperature does not exceed 70° C.
After 1 hour of reaction it is checked by FTIR analysis that the prepolymer has the last traces (0.139%) of NCO groups and, at about 60° C., 0.392 g (0.02 eq) of dimethyl ethanol amine is added.
After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis and, at about 50° C., a mixture formed by 167.87 g of demineralised water and 0.604 g of 70% methanesulphonic acid is added in water. The organic solvent (ethyl acetate) is distilled off under vacuum.
A stable milky dispersion is obtained, with a solids content of 40.4% by weight.
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
The reaction temperature is brought to 70° C. and kept in a range comprised from 70° C. to 75° C. for about two hours, until the determination of the free NCO groups still present gives a value of 6.7% by weight.
Subsequently, 25.22 g (0.1761 eq) of 5-methyl-3-heptanoneoxime is dripped over a period of about 1 hour, taking care that the reaction temperature does not exceed 70° C.
After 1 hour of reaction it is checked by FTIR analysis that the prepolymer has the last traces (0.139%) of NCO groups and, at about 60° C., 0.392 g (0.02 eq) of dimethyl ethanol amine is added.
After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis and, at about 50° C., a mixture formed by 175.94 g of demineralised water and 0.604 g of 70% methanesulphonic acid is added in water. The organic solvent (ethyl acetate) is distilled off under vacuum.
A stable milky dispersion is obtained, with a solids content of 40.3% by weight.
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
The reaction temperature is brought to 80° C. and maintained for about one hour until the determination of the free NCO groups still present by titration gives a value of 17.4% by weight.
It is then cooled to 70° C. to add in portions in 20 minutes 34.1 g (0.310 eq) of 2-isopropyl-1H-imidazole with a temperature range comprised from 70° C. to 75° C. After 15 minutes of reaction, it is checked by titration that the determination of the free NCO groups still present gives a value of 5.5%.
It is proceeded with the addition of 17.6 g (0.182 eq) of tetraethylene glycol in 20 minutes. After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis. It is then cooled to about 50° C., to add 256.7 g of demineralised water under stirring.
A stable milky dispersion is obtained, with a solid content of 38.5% by weight.
A glass flask, equipped with an internal thermometer, stirrer and chiller, in a nitrogen atmosphere and at room temperature, is charged—under stirring—with:
The reaction temperature is brought to 80° C. and maintained for about one hour until the determination of the free NCO groups still present by titration gives a value of 17.4% by weight.
It is then cooled to 70° C. to add in portions in 20 minutes 34.1 g (0.310 eq) of 2-ethyl-4-methylimidazole with a temperature range comprised from 70° C. to 75° C. After 15 minutes of reaction, it is checked by titration that the determination of the free NCO groups still present gives a value of 5.5%.
It is proceeded with the addition of 17.6 g (0.182 eq) of tetraethylene glycol in 20 minutes. After 1 hour of reaction, the disappearance of the NCO groups is checked by FTIR analysis. It is then cooled to about 50° C., to add 256.6 g of demineralised water under stirring.
A stable milky dispersion is obtained, with a solid content of 38.4% by weight.
The three oximes (i), (ii), (iii) subject-matter of the present invention have been employed in a typical composition (referred to in Examples 1, 2, 3) and the respective products in water have been tested to evaluate their performance in comparison with the current marketed products.
Four tests have been carried out so named:
To assess water stability, a stability study was carried out using the Turbiscan Tower instrument. Such an instrument is configured to analyse destabilization mechanisms in concentrated dispersed media, and thus to provide accelerated ageing testing on unstressed real products.
The experimental conditions are shown in Table 4 below.
19 h
19 h
19 h
d 19 h
indicates data missing or illegible when filed
The Turbiscan analysis report is shown in
All four formulations prepared were stable as they did not show any sedimentations. The graphs reported in
The base+isocyanate compositions have a good yield, comparable and sometimes superior to the reference composition (Comparative Example 5 isocyanate blocked with MEKO).
The percentages indicated below are percentages by weight of the individual component with respect to the total weight of formula, unless otherwise specified.
The treatment and evaluation of treated fabrics comprise three steps:
The wetting solutions used for the Padding method are obtained by diluting the textile protective agent solution combined with the cross-linking agent. The mixture between the two components usually has a proportion comprised from 90:10 to 80:20, respectively of protective agent and crosslinking agent. The dilution is carried out before treatment, with distilled water, to obtain a concentration comprised between 30 g/L and 100 g/L. Depending on the treated fabric or skin and the type of protective agent applied, a more or less diluted solution will be used (for example, higher weights are used on cotton compared to polyester or polyamide; as a further example, a lower weight will be needed for a fluorinated product compared to a non-fluorinated product).
The tests that are usually carried out to evaluate the yield of a treated substrate are the following:
A treated substrate is placed tilted at 45° below a funnel from which 250 ml of deionized water are poured. The wettability of the treated substrate and the resistance thereof are then evaluated according to the AATCC 22 evaluation. The results of the tests carried out according to AATCC 22-Spray test are illustrated in schematic form in Table 5 below.
From the previous Tables 5.A and 5.B the following conclusions can be drawn:
The non-fluorinated resin product applied without the use of a blocked isocyanate shows both in the cotton and in the polyamide a low resistance to washes. The photographic index already drops after 4 washes to 70/80 for cotton and to 80 after 6 washes in the case of polyamide.
All new products prepared with non-fluorinated base and isocyanates blocked with oxime (i), (ii), (iii) and oxime mixture (iv) show after four washes water repellency properties similar to Product B blocked with MEKO. The water repellency properties are constant with a higher number of washes confirming that the products subject-matter of the present invention are effective crosslinkers. The effectiveness of the products subject-matter of the present invention is also confirmed by the good performance despite containing a lower % NCO compared to standard products blocked with MEKO.
Further tests, carried out at lower temperatures (drying 100° C. and crosslinking 120° C.) using (iii) 5-methyl-3-heptanone oxime as blocking agent, show slightly higher water repellency properties (spray test) compared to formulations containing isocyanates blocked with MEKO. In this regard, see Table 6 below, where Product C is fluorinated resin (see Example 11 in this regard).
Similar results regarding stability and water repellency were obtained by using as blocking agents 2-isopropyl-1H-imidazole Example 9 and 2-ethyl-4-methylimidazole Example 10.
Drops of oils with different surface tensions are applied to a treated substrate. The drops are removed after 30 seconds and the absorption of the drop by the treated surface is evaluated. The oil repellency grade is identified as the highest among the tested grades that is not completely absorbed within 30 seconds. The following Table 7 illustrates the oil grades applied:
The tests performed have been reported in Table 8.
From the previous Tables 8.A, 8.B, 8.C the following conclusions can be drawn:
The tests performed with the isocyanates blocked with the oximes (i)-(iii) and the mixture thereof (iv) in formulation with Product C (fluorinated resin) show—with the same material (cotton, polyamide, polyester)—similar properties evaluated with AATCC Method 118, comparable with those obtained with Product D, reference product containing MEKO as blocking agent.
Drops of a water/isopropyl alcohol mixture (IPA; isopropyl alcohol) with different proportions and different surface tensions are applied to a treated substrate. The drops are removed after 10 seconds and the absorption of the drop by the treated surface is evaluated. The water repellency grade is identified as the highest of the tested grades that is not completely absorbed within 10 seconds. The following Table 9 illustrates the water/IPA solutions used:
The tests performed have been reported in Table 10.
From the previous Tables 10.A, 10.B, 10.C the following conclusions can be drawn:
The tests performed with the isocyanates blocked with the oximes (i)-(iii) and the mixture thereof (iv) in formulation with Product C (fluorinated resin) show similar properties evaluated with Method AATCC 193, comparable with those obtained with Product D, reference product containing MEKO as blocking agent.
The composition may comprise—in addition to said oximes (i)-(iv) or to said imidazole compound of general formula (I)—a polyacrylate consisting of several (meth)acrylic acid esters and optionally further ingredients chosen from paraffin wax and polysiloxanes. The entire composition is suitably used to treat a substrate such as fabrics or skins in order to give hydrophobic, or hydro/oleophobic properties in case the polyacrylate is functionalized with fluorinated chains.
Preferably, the polyacrylate is obtained by means of a copolymerization of the following monomer units (a)-(d):
Rf-Rh-OCOC(R5)═CH2
Rz-OCOC(R5)═CH2 (II)
Ry-OCOC(R5)═CH2
Rz-OCOC(R5)═CH2
Hereinafter, for the sake of brevity, the term “(meth)acrylate” or similar shall mean “acrylate or methacrylate”.
The synthesis of the (meth)acrylate polymer is carried out in two distinct steps:
The monomer mixture is heated until complete melting, preferably in the presence of solvents. The mixture is dispersed in hot water at 70° C. containing suitable surfactants, and is vigorously stirred using for example a Turrax. A subsequent step involves high pressure homogenization (e.g. 400 bar and a temperature of 65-75° C.) using a Manton-Gaulin type homogenizer. To the resulting mixture it is then added a radical initiator, possibly dissolved or dispersed in water. The polymerization reaction is carried out for several hours at a temperature of 60-70° C., until the monomers are exhausted.
Advantageously, for all the compounds subject-matter of the present invention the deblocking temperatures are not particularly high.
This aspect is an application advantage and is particularly important with a view to optimizing energy consumption and improving process productivity.
Advantageously, for all the compounds subject-matter of the present invention the presence of differentiated deblocking temperatures allows to obtain a series of flexibilities, for example necessary to optimize the processes of use of such compositions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102022000001934 | Feb 2022 | IT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2023/050966 | 2/3/2023 | WO |
