Blocked isocyanate compositions, use of compounds as blocking agents for isocyanates

Abstract

A composition comprising or consisting of: an isocyanate blocked with a blocking agent selected from the group consisting of: (i) optionally 2-pentanone oxime; (ii) 4-methylpentan-2-one oxime; (iii) 5-methyl-3-heptanone oxime; and (iv) a mixture of two or more of (i) to (iii); and optionally one or more technical additives.

Description

[Technical field]

[0001] The present invention refers to a composition comprising or consisting of an isocyanate blocked with a blocking agent selected from the group consisting of (i) to (iv), and optionally one or more technical additives.

[0002] Additionally, the present invention refers to the use of (i)-(iv) as blocking agents for isocyanates.

[0003] Furthermore, the present invention refers to the use of a composition comprising or consisting of an isocyanate blocked by a blocking agent, and optionally one or more technical additives, in the water- and / or oil-repellent treatment of fabrics or leather, said blocking agent being at least one imidazole compound of general formula (I).

[0004] Furthermore, the present invention refers to the use of the imidazole compounds of general formula (I) as blocking agents for blocked isocyanates in the water- and / or oil-repellent treatment of fabrics or leather. [Background technology]

[0005] Methyl ethyl ketoxime (or 2-butanone oxime, CAS number 96-29-7, abbreviated "MEKO") is a colorless liquid and is the oxime derived from methyl ethyl ketone.

[0006] MEKO is primarily used as an anti-skinning agent in oil and latex paints and coatings, as it prevents the formation of a solid film on said paints and coatings. MEKO works by combining with drying agents (especially metal salts) that catalyze the oxidative crosslinking of the oils contained in the paints and coatings. When the paint or coating is applied to a surface, MEKO evaporates, thereby allowing the drying process to proceed.

[0007] MEKO is also widely used as a blocking agent for isocyanates in automotive e-coating and paintwork, as a curing agent for silicone rubber for its excellent water and heat resistance, in fabric treatment in combination with non-fluorinated resins for water repellency or in combination with fluorinated resins for water and / or oil repellency, and as an adhesion promoter in the printing industry.

[0008] However, MEKO presents some significant risks to human health. Indeed, MEKO was subject to an evaluation process (SEv; Substance Evaluation Process), the results of which were reported in a Substance Evaluation Report and led to the drafting of a proposal for a Harmonized Classification of Substances (CLH).

[0009] Based on this proposal, ECHA's Risk Assessment Committee (RAC) adopted an opinion in September 2018 to classify MEKO as carcinogenic (Carc.) 1B, H350: possibly causing cancer.

[0010] The process also results in the following hazard attributes: 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; Specific Target Organ Toxicity (Single Exposure) (STOT SE) 3, H336: May cause drowsiness or dizziness; Specific Target Organ Toxicity (Single Exposure) 1, H370 (Upper Respiratory Tract): Causes organ damage; and Specific Target Organ Toxicity (Repeated Exposure) 2, H373 (Blood System): May cause organ damage with prolonged or repeated exposure.

[0011] The corresponding inclusion in Annex VI of Regulation (EC) No. 1272 / 2008 (CLP) came into force at the 15th ATP in August 2020. Therefore, from March 2022 onwards, mixtures containing the substance MEKO at concentrations above 0.1% will be obliged to be classified and labelled as carcinogenic class 1B (H350).

[0012] Prior art document JP 05-179573A relates to water and oil repellents. Prior art document China Patent Publication No. 110981750A discloses a method for synthesizing 2-pentanone oxime by ammoxidation reaction. Summary of the Invention [Means for solving the problem]

[0013] After a long period of intensive research and development activity, the applicant has identified several oximes that can be used as alternatives to MEKO and that adequately address existing limitations, drawbacks and problems.

[0014] In particular, the compounds identified in the present invention have significantly less toxic properties than MEKO, are typically available in large quantities on the market at an acceptable cost, even if at least at present their cost is higher than that of MEKO, are capable of producing blocked isocyanates having achromatic colors (i.e., tending to white or light yellow), have reaction rates comparable to the corresponding products blocked by MEKO, and exhibit similar, and in some cases superior, properties compared to those currently in use.

[0015] An object of the present invention is therefore a composition comprising or consisting of an isocyanate blocked with a blocking agent selected from the group consisting of (i) to (iv) and optionally one or more technical additives, having the characteristics defined in the appended claims.

[0016] Furthermore, an object of the present invention is the use of a blocking agent selected from the group consisting of (i) to (iv) as a blocking agent for isocyanates, having the characteristics defined in the appended claims.

[0017] Furthermore, the present invention refers to the use of a composition comprising or consisting of an isocyanate blocked by a blocking agent, and optionally one or more technical additives, in the water- and / or oil-repellent treatment of fabrics or leather, having the characteristics defined in the appended claims, said blocking agent being at least one imidazole compound of general formula (I).

[0018] Furthermore, the present invention refers to the use of imidazole compounds of general formula (I) as blocking agents for blocked isocyanates in the water- and / or oil-repellent treatment of fabrics or leather, having the characteristics defined in the appended claims.

[0019] Preferred embodiments of the present invention are described below by way of example, and therefore not by way of limitation, with reference to tables. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 shows a DSC diagram performed on an isocyanate blocked with an imidazole compound according to the examples. [Diagram 2] FIG. 2 shows a DSC diagram performed on an isocyanate blocked with an imidazole compound according to the examples. [Diagram 3] FIG. 2 shows a DSC diagram performed on an oxime-blocked isocyanate according to the examples. [Figure 4] FIG. 2 shows a DSC diagram performed on an oxime-blocked isocyanate according to the examples. [Diagram 5] FIG. 1 shows a stability analysis report by Turbiscan analysis according to an embodiment. [Figure 6] FIG. 1 shows a stability analysis report by Turbiscan analysis according to an embodiment. [Figure 7] FIG. 1 shows a stability analysis report by Turbiscan analysis according to an embodiment. [Figure 8] FIG. 1 shows a stability analysis report by Turbiscan analysis according to an embodiment. [Figure 9] FIG. 1 shows a stability analysis report by Turbiscan analysis according to an embodiment. [Figure 10] FIG. 1 shows a stability analysis report by Turbiscan analysis according to an embodiment. [Figure 11] FIG. 2 is a diagram showing an overall view of a vertical orientation foulard machine used in the tests of the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] An object of the present invention is therefore a composition comprising or consisting of: - isocyanates blocked with a blocking agent selected from the group consisting of: (i) optionally 2-pentanone oxime (CAS number 623-40-5); (ii) 4-methylpentan-2-one oxime (CAS no. 105-44-2); (iii) 5-methyl-3-heptanone oxime (CAS number 22457-23-4); and (iv) A mixture of two or more of (i) to (iii); - optionally one or more technical additives.

[0022] In the description of the present invention, the term "blocked isocyanate" means a reaction product between an isocyanate and said blocking agent, such that at least one isocyanate functional group is blocked (non-reactive).

[0023] Preferably, the 2-pentanone oxime is not obtained by an ammoxidation reaction.

[0024] More preferably, the mixture (iv) comprises (iii) 5-methyl-3-heptanone oxime in combination with: (i) 2-pentanone oxime; and / or (ii) 4-Methylpentan-2-one oxime.

[0025] Preferably, in the mixture (iv), - (iii):(i) or (iii):(ii) are in a weight ratio of 20:1 to 1:20, preferably 10:1 to 1:10, more preferably 5:1 to 1:5; or The weight ratio of [(iii)]:[(i)+(ii)] is within the range of 20:1 to 1:20, preferably 10:1 to 1:10, and more preferably 5:1 to 1:5.

[0026] The isocyanate is preferably selected from the group consisting of: (a) 1,5-pentamethylene diisocyanate (PDI) and its polymers, preferably trimers, optionally of bio-based origin; (b) toluene diisocyanate (TDI) and its adducts, preferably TDI trimer; (c) polyisocyanates derived from hexamethylene diisocyanate (HDI) obtained by trimerization, biuretization, and / or allophanatization processes; (d) polyisocyanates derived from isophorone diisocyanate (IPDI) obtained by trimerization, biuretization, and / or allophanatization processes; (e) 4,4'-methylenedicyclohexyl diisocyanate (H12MDI); (f) trimethylhexamethylene diisocyanate (TMDI); (g) 1,4-cyclohexyl diisocyanate (CHDI); (h) tetramethylxylene diisocyanate (TMXDI); and (i) Any mixture of two or more selected from (a) to (h).

[0027] Preferably, the (d) polyisocyanate derived from isophorone diisocyanate (IPDI) obtained by a trimerization, biuretization, and / or allophanatization process comprises or consists of the oligomerization products of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate with butan-1-ol and pentan-1-ol and 2-ethylhexan-1-ol, in the allophanate form.

[0028] More preferably, said (d) comprises a product EC / Listing No: 933-047-9, which comprises or consists of a mixture of compounds represented by the following general formula (II):

[0029] [ka] (wherein R is the alcohol residue of butan-1-ol, pentan-1-ol and 2-ethylhexan-1-ol).

[0030] The isocyanate is more preferably selected from the group consisting of: (a) 1,5-pentamethylene diisocyanate (PDI) and its polymers, preferably trimers, optionally of bio-based origin; (b) adducts of toluene diisocyanate (TDI) obtained by reaction of trimethylolpropane with toluene diisocyanate, preferably trimers, isocyanurates from hexamethylene diisocyanate (HDI) and isocyanurates from isophorone diisocyanate (IPDI), more preferably reaction products of trimethylolpropane with a mixture of isomeric 2,4 toluene diisocyanate and 2,6 toluene diisocyanate, even more preferably said isomers in a ratio by weight comprised between 90:10 and 70:30, between 85:15 and 75:15, for example 80:20; (c) hexamethylene 1,6-diisocyanate trimer; and (i) A mixture of (a)-(c).

[0031] The compositions comprising or consisting of a blocked isocyanate and optionally one or more technical additives are preferably non-ionic and / or ionic aqueous suspensions or dispersions.

[0032] To make the composition stable in the form of an aqueous dispersion of the blocked isocyanate, it is possible to insert into the molecule a carboxylated ionic group (e.g. derived from dimethylolpropionic acid) or an alkoxylated chain with monoalcohol functionality (e.g. polyethylene glycol monomethyl ether with molecular weights of 350, 500 or 750 amu).More preferably, the suspension or dispersion comprises a mixture of water and a cosolvent, preferably in a weight ratio comprised between 2% and 50%, preferably between 5% and 20%.

[0033] By way of example only, the co-solvent is selected from the group consisting of propylene glycol dimethyl ether, acetone, or other low boiling organic solvents.

[0034] The composition is preferably free of methyl ethyl ketoxime (MEKO).

[0035] Furthermore, the object of the present invention is the use as blocking agent for isocyanates: (i) optionally 2-pentanone oxime; (ii) 4-methylpentan-2-one oxime; (iii) 5-methyl-3-heptanone oxime; or (iv) A mixture of two or more of (i) to (iii).

[0036] Preferably, the mixture (iv) comprises (iii) 5-methyl-3-heptanone oxime in combination with: (i) 2-pentanone oxime; and / or (ii) 4-Methylpentan-2-one oxime.

[0037] Preferably, in the mixture (iv), - (iii):(i) or (iii):(ii) are in a weight ratio of 20:1 to 1:20, preferably 10:1 to 1:10, more preferably 5:1 to 1:5; or The weight ratio of [(iii)]:[(i)+(ii)] is within the range of 20:1 to 1:20, preferably 10:1 to 1:10, and more preferably 5:1 to 1:5.

[0038] The subject of the present invention is further the use of imidazole compounds of the following general formula (I) as blocking agents for isocyanates in the water- and / or oil-repellent treatment of fabrics or leather.

[0039] [ka] (In the formula, R1=H or CH3; R2=H, CH3, CH2CH3, or CH(CH3)2)

[0040] Preferably, the imidazole compound is 2-isopropyl-1H-imidazole (CAS number 36947-68-9) or 2-ethyl-4-methylimidazole (CAS number 931-36-2).

[0041] More preferably, the imidazole compound is 2-ethyl-4-methylimidazole.

[0042] Preferably, said use comprises deblocking of said isocyanates with said blocking agent in the water and / or oil repellent treatment of fabrics or leather.

[0043] Further, the object of the present invention is to provide a method for the water- and / or oil-repellent treatment of fabrics or leather, - isocyanates blocked with a blocking agent, and - optionally one or more technical additives Use of a composition comprising or consisting of The blocking agent is at least one imidazole compound of the following general formula (I):

[0044] [ka] (In the formula, R1=H or CH3; R2 = H, CH3, CH2CH3 or CH(CH3)2)

[0045] In this description, the expression "at least one imidazole compound" means that the composition may contain a single imidazole compound of general formula (I) or a mixture of two or more imidazole compounds of general formula (I) in which R1 and / or R2 are different from each other.

[0046] Preferably, the imidazole compound, or the imidazole compound of the mixture, is 2-isopropyl-1H-imidazole (CAS number 36947-68-9) or 2-ethyl-4-methylimidazole (CAS number 931-36-2).More preferably, the composition comprises a mixture of 2-isopropyl-1H-imidazole and 2-ethyl-4-methylimidazole.

[0047] Even more preferably, the imidazole compound, or the imidazole compound of said mixture, is 2-ethyl-4-methylimidazole.

[0048] The blocked isocyanates - ionic or non-ionic - are preferably selected from the group consisting of: (a) 1,5-pentamethylene diisocyanate (PDI) and its polymers, preferably trimers, optionally of bio-based origin; (b) toluene diisocyanate (TDI) and its adducts, preferably trimers of TDI, more preferably reaction products of trimethylolpropane with a mixture of isomeric 2,4 toluene diisocyanate and 2,6 toluene diisocyanate, even more preferably said isomers in a ratio by weight comprised between 90:10 and 70:30, 85:15 and 75:25, for example 80:20; (c) polyisocyanates derived from hexamethylene diisocyanate (HDI) obtained by trimerization, biuretization, and / or allophanatization processes, preferably hexamethylene 1,6-diisocyanate trimer; (d) polyisocyanates derived from isophorone diisocyanate (IPDI) obtained by trimerization, biuretization, and / or allophanatization processes; (e) 4,4'-methylenedicyclohexyl diisocyanate (H12MDI); (f) trimethylhexamethylene diisocyanate (TMDI); (g) 1,4-cyclohexyl diisocyanate (CHDI); (h) tetramethylxylene diisocyanate (TMXDI); and (i) Any mixture of two or more selected from (a) to (h).

[0049] The composition is preferably an aqueous suspension or dispersion.

[0050] More preferably, the composition does not include methyl ethyl ketoxime (MEKO).

[0051] The composition preferably comprises acrylic or methacrylic acid esters (in short, polyacrylates) functionalized with fluorinated chains.

[0052] More preferably, the polyacrylate is obtained by copolymerization of the following monomer units (a) to (d): (a) 0.1% to 90% by weight of one or more acrylic or methacrylic monomers of the following general formula: Rf-Rh-OCOC(R5)=CH2 (In the formula, R5 is a methyl or hydrogen group; Rf is a linear or branched perfluorinated alkyl group having 1 to 6 carbon atoms, preferably 4 to 6 carbon atoms, - Rh(CH2) n group, where n is an integer between 1 and 6, preferably between 2 and 4. (b) 0.1% to 80% by weight of one or more acrylic or methacrylic monomers of general formula (II) Rz-OCOC(R5)=CH2(II) (In the formula, Rz is a linear or branched benzyl or alkyl group containing 1 to 30 carbon atoms; - R5 is a methyl or hydrogen group. (c) 1% to 20% by weight of at least one acrylic or methacrylic functional group and a compound represented by the general formula R 2 -OCOC(R5)=CH2(wherein, R 2 one or more monomers having at least one carboxylic acid function of the formula (COOH)-(Rh)m-, where Rh and R5 are defined above and m can assume the value 0 or 1, or itaconic acid, (d) 0.1% to 15% by weight of one or more monomers having at least one vinyl functional group; (e) 1% to 20% by weight of one or more acrylic or methacrylic monomers of the following general formula: Ry-OCOC(R5)=CH2 (In the formula, Ry is the R-[Si(CH3)2O]l-Si(CH3)2-(Rh)m- group, where l is an integer comprised between 2 and 30, R is a linear or branched alkyl group having a number of carbon atoms between 1 and 20, Rh and m are as defined above, - R5 is a methyl or hydrogen group. (f) 0 to 15% by weight of one or more acrylic or methacrylic monomers of the following general formula: Rz-OCOC(R5)=CH2 (In the formula, Rz is -R 5 A -(Rh)m- group, where R5 is a hydroxyl or epoxy group and m is defined above.

[0053] The composition further comprises at least one additional component selected from paraffin wax and a polysiloxane compound.

[0054] Below, by way of non-limiting examples, some embodiments of the present invention are reported. EXAMPLES

[0055] Experimental determination of the unblocking temperature, reaction rate, and product color. The imidazole compounds 2-isopropyl-1H-imidazole (CAS number 36947-68-9) and 2-ethyl-4-methylimidazole (CAS number 931-36-2) were reacted with the following commercially available isocyanates: - Desmodur® Ultra N 3300 (from Covestro AG): homopolymer (trimer) of hexamethylene 1,6-diisocyanate (CAS number 28182-81-2; EC / list number: 931-274-8); - Polurgreen AD 01: adducts of toluene diisocyanate (TDI), in particular the reaction products of trimethylolpropane with toluene diisocyanate (mixture of 2,4- and 2,6-isomers in a weight ratio of 80:20); A blocked isocyanate was obtained.

[0056] DSC (Differential Scanning Calorimetry) studies were performed on the blocked isocyanates to determine their unblocking temperatures. The instrument used was a Discovery DSC25AUTO TA INSTRUMENTS (WATERS CORPORATIONS) serial number DSC2A-01063.

[0057] The proposed DSC method consists of preparing the blocked isocyanate in a nitrogen atmosphere and then subjecting it to the following temperature increase: - a first temperature increase from 25 to 250 °C at 10 °C / min, so that a change in the slope of the profile, representing the onset of the deblocking temperature, can be observed; - Cool the sample to 25°C; A second temperature increase from 25° C. to 250° C. at 10° C. / min, so that complete deblocking of the isocyanates can be observed.

[0058] The results are shown in Table 1 below.

[0059] [Table 1]

[0060] Exemplary DSC spectra are reported below in Figure 1 (for test LAB220621) and Figure 2 (for test LAB230621).

[0061] In general, the reaction of isocyanates with imidazoles shows good reaction kinetics, with the unblocking temperatures of both imidazoles tested falling within the range of 89.9°C to 98°C.

[0062] Regarding the appearance of blocked isocyanates, - reaction of Desmodur® Ultra N 3300 with 2-isopropyl-1H-imidazole; and - Reaction of Desmodur® Ultra N 3300 with 2-ethyl-4-methylimidazole The product resulting from is slightly yellowish in color.

[0063] The three oximes (i), (ii), (iii) of the subject invention are reacted individually with the commercially available isocyanates mentioned above to give: - Desmodur® Ultra N 3300; - Polurgreen AD 01; A blocked isocyanate was obtained.

[0064] DSC studies (differential scanning calorimetry) as described above were carried out on the blocked isocyanates to determine their unblocking temperatures.

[0065] The results are shown in Table 2 below.

[0066] [Table 2]

[0067] Exemplary DSC spectra are reported below in Figure 3 (for the LAB030821 study) and Figure 4 (for the LAB040821 study).

[0068] All the products obtained were white in color. The reactivity of all the oximes tested with both isocyanates was high.

[0069] From the above data, it is apparent that the three oximes (i), (ii) and (iii) have very promising characteristics for use as blocking agents for isocyanates due to their classification, reactivity and the colour of the resulting final products.

[0070] The temperature values ​​in Table 2 suggest that the three oximes (i), (ii) and (iii) can also be used in combination in a single composition in order to adjust the deblocking temperature depending on the contingency, thus allowing the flexibility required to optimize the use process of such compositions.

[0071] Moreover, as can be noted, the unblocking temperatures are not particularly high, an aspect that is particularly important with regard to optimizing energy consumption and increasing process productivity.

[0072] The above test was repeated by blocking other isocyanate products with oximes (i), (ii) and (iii). The isocyanate products were as follows: - Desmodur® eco N 7300 (from Covestro AG): 1,5-Pentamethylene diisocyanate (PDI; trimer) - Bayhydur® eco 701-90 (from Covestro AG): bio-based 1,5-pentamethylene diisocyanate (PDI).

[0073] The resulting blocked isocyanate was subjected to the DSC test described above to determine its unblocking temperature.

[0074] The results are shown in Table 3 below.

[0075] [Table 3]

[0076] All the products obtained were white in color. The reactivity of all the oximes tested with both isocyanates was high.

[0077] The results obtained are consistent with the first series of studies.

[0078] It should be noted that tests carried out on bio-based PDIs revealed relatively low deblocking temperatures, with important results in terms of optimizing energy consumption and increasing process productivity. For the same isocyanate, lower deblocking temperatures can be achieved by increasing the chain length of the oxime blocking agent.

[0079] Obtaining an aqueous composition of blocked polyisocyanate. The typical preparation procedure consists in reacting polyisocyanate with methoxypolyethylene glycol at about 80° C. under stirring. The additive methoxypolyethylene glycol is then essential to make the product dispersible in water. The resulting product is partially blocked with a blocking agent under stirring at a temperature of about 70° C. The remaining free NCO groups are reacted with difunctional compounds diglycol and / or diamine at about 70° C. to increase its molecular weight. The reaction mixture is then cooled to 50° C. and then water is added under stirring to a concentration of about 40%.

[0080] The following methods are reported for making compositions which are aqueous suspensions or dispersions of ionic or non-ionic blocked isocyanates. The following were used as blocking agents: (i) 2-pentanone oxime; or (ii) 4-methylpentan-2-one oxime; or (iii) 5-methyl-3-heptanone oxime; (iv) A mixture of (i) to (iii)

[0081] Example 1 Blocking agent (i) 2-pentanone oxime In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following are charged with stirring under a nitrogen atmosphere at room temperature: - 100 g (0.518 equivalents) of Desmodur® Ultra N 3300 with an NCO content of 23%; - 19.43 g (0.026 eq.) of pre-melted methoxy PEG 750.

[0082] The reaction temperature is raised to 80° C. and maintained for approximately 1 hour until the free NCO groups still present are determined by titration to a value of 17.4% by weight.

[0083] It is then cooled to 70° C. and 31.4 g (0.310 eq.) of 2-pentanone oxime are added dropwise in 20 min, keeping the mixture in the temperature range comprised between 70° C. and 75° C. After 15 min of reaction, the progress is checked by titration, determining the free NCO groups still present, until a value of 5.4% is obtained.

[0084] 17.6 g (0.182 eq.) of tetraethylene glycol is added in 20 min to allow the reaction to proceed. After 1 h of reaction, FTIR analysis confirms the disappearance of the NCO groups. It is then cooled to about 50° C. and 252.6 g of demineralized water is added with stirring.

[0085] A stable milky dispersion is obtained with a solids content of 38.2% by weight.

[0086] Example 2 Blocking agent (ii) 4-methylpentan-2-one oxime In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following is charged with stirring under a nitrogen atmosphere at room temperature: - 100 g (0.518 equivalents) of Desmodur® Ultra N 3300 with an NCO content of 23%; - 19.43 g (0.026 eq.) of pre-melted methoxy PEG 750.

[0087] The reaction temperature is raised to 80° C. and maintained for approximately 1 hour until the free NCO groups still present are determined by titration to a value of 17.4% by weight.

[0088] It is then cooled to 70° C. and 35.7 g (0.310 equivalents) of 4-methylpentan-2-one oxime are added dropwise in 20 minutes at a temperature range comprised between 70° C. and 75° C. After 15 minutes of reaction, the free NCO groups still present are determined by titration to give a value of 5.4%.

[0089] 17.6 g (0.182 eq.) of tetraethylene glycol is added in 20 min to allow the reaction to proceed. After 1 h of reaction, FTIR analysis confirms the disappearance of the NCO groups. It is then cooled to about 50° C. and 259.1 g of demineralized water is added with stirring.

[0090] A stable milky dispersion is obtained with a solids content of 37.7% by weight.

[0091] Example 3 Blocking agent (iii) 5-methyl-3-heptanone oxime In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following is charged with stirring under a nitrogen atmosphere at room temperature: - 100 g (0.518 equivalents) of Desmodur® Ultra N 3300 with an NCO content of 23%; - 19.43 g (0.026 eq.) of pre-melted methoxy PEG 750.

[0092] The reaction temperature is raised to 80° C. and maintained for approximately 1 hour until the free NCO groups still present are determined by titration to a value of 17.4% by weight.

[0093] It is then cooled to 70° C. and 44.4 g (0.310 equivalents) of 5-methyl-3-heptanone oxime are added dropwise in 20 minutes at a temperature range comprised between 70° C. and 75° C. After 15 minutes of reaction, the free NCO groups still present are determined by titration to give a value of 5.4%.

[0094] 17.6 g (0.182 eq.) of tetraethylene glycol is added in 20 min to allow the reaction to proceed. After 1 h of reaction, FTIR analysis confirms the disappearance of the NCO groups. It is then cooled to about 50° C. and 272.1 g of demineralized water is added with stirring.

[0095] A stable milky dispersion is obtained with a solids content of 37.7% by weight.

[0096] Example 4 Blocking agent mixture (iv) of oximes (i) to (iii) In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following is charged with stirring under a nitrogen atmosphere at room temperature: - 100 g (0.518 equivalents) of Desmodur® Ultra N 3300 with an NCO content of 23%; - 19.43 g (0.026 eq.) of pre-melted methoxy PEG 750.

[0097] The reaction temperature is raised to 80° C. and maintained for approximately 1 hour until the free NCO groups still present are determined by titration to a value of 17.4% by weight.

[0098] It is then cooled to 70° C. and the following is added dropwise in 30 minutes at a temperature range comprised between 70° C. and 75° C.: - 10.47 g (0.103 eq.) of 2-pentanone oxime, followed by - 11.93 g (0.104 eq.) of 4-methylpentan-2-one oxime, and finally - 14.84 g (0.104 eq.) of 5-methyl-3-heptanone oxime.

[0099] It should be noted that the addition of the various oximes can be carried out in a different order than that shown.

[0100] After 15 minutes of reaction, the free NCO groups still present are determined by titration to give a value of 5.4%.

[0101] 17.6 g (0.182 eq.) of tetraethylene glycol is added in 20 min to allow the reaction to proceed. After 1 h of reaction, the disappearance of the NCO groups is confirmed by FTIR analysis. It is then cooled to about 50° C. and 261.4 g of demineralized water is added with stirring.

[0102] A stable milky dispersion is obtained with a solids content of 39.6% by weight.

[0103] Comparative Example 5 MEKO Blocking Agent (see US2006167204) In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following is charged with stirring under a nitrogen atmosphere at room temperature: - 70.0 g (0.22013 equivalents) of Polurgreen AD 01 with an NCO content of 13.2% by weight and 75% by weight; - 12.5 g of ethyl acetate; - 29.717 g (0.03962 equivalents) of pre-melted polyethylene glycol MW1500.

[0104] The reaction temperature is raised to 70° C. and maintained within the range of 70° C. to 75° C. for about 2 hours until the free NCO groups still present are determined to give a value of 6.7% by weight.

[0105] Next, 15.34 g (0.1761 equivalents) of MEKO is added dropwise over about 1 hour, taking care not to allow the reaction temperature to exceed 70°C.

[0106] After 1 hour of reaction, which confirms by FTIR analysis that the prepolymer has only the last traces (0.145%) of NCO groups, at about 60° C., 0.392 g (0.02 equivalents) of dimethylethanolamine is added.

[0107] After 1 hour of reaction, the disappearance of the NCO groups is confirmed by FTIR analysis, and a mixture formed of 150.86 g of demineralized water and 0.604 g of 70% methanesulfonic acid is added to the water at about 50° C. The organic solvent (ethyl acetate) is distilled off under vacuum.

[0108] A stable milky dispersion is obtained with a solids content of 40.5% by weight.

[0109] Example 6 Blocking agent (i) 2-pentanone oxime In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following is charged with stirring under a nitrogen atmosphere at room temperature: - 70.0 g (0.22013 eq.) of Polurgreen AD 01; - 12.5 g of ethyl acetate; - 29.71 g (0.03962 equivalents) of pre-melted polyethylene glycol MW1500.

[0110] The reaction temperature is raised to 70° C. and maintained within the range of 70° C. to 75° C. for about 2 hours until the free NCO groups still present are determined to give a value of 6.7% by weight.

[0111] Next, 17.81 g (0.1761 equivalents) of 2-pentanone oxime is added dropwise over about 1 hour, while being careful not to allow the reaction temperature to exceed 70°C.

[0112] After 1 hour of reaction, FTIR analysis confirms that the prepolymer has only the last traces (0.142%) of NCO groups, and at about 60° C., 0.392 g (0.02 eq.) of dimethylethanolamine is added.

[0113] After 1 hour of reaction, the disappearance of the NCO groups is confirmed by FTIR analysis, and a mixture formed of 163.85 g of demineralized water and 0.604 g of 70% methanesulfonic acid is added to the water at about 50° C. The organic solvent (ethyl acetate) is distilled off under vacuum.

[0114] A stable milky dispersion is obtained with a solids content of 40.3% by weight.

[0115] Example 7 Blocking agent (ii) 4-methylpentan-2-one oxime In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following is charged with stirring under a nitrogen atmosphere at room temperature: - 70.0 g (0.22013 eq.) of Polurgreen AD 01; - 12.5 g of ethyl acetate; - 29.71 g (0.03962 equivalents) of pre-melted polyethylene glycol MW1500.

[0116] The reaction temperature is raised to 70° C. and maintained within the range of 70° C. to 75° C. for about 2 hours until the free NCO groups still present are determined to give a value of 6.7% by weight.

[0117] Then, 20.28 g (0.1761 equivalents) of 4-methylpentan-2-one oxime is added dropwise over about 1 hour, while taking care not to allow the reaction temperature to exceed 70°C.

[0118] After 1 hour of reaction, FTIR analysis confirms that the prepolymer has only the last traces (0.139%) of NCO groups, and at about 60° C., 0.392 g (0.02 equivalents) of dimethylethanolamine is added.

[0119] After 1 hour of reaction, the disappearance of the NCO groups is confirmed by FTIR analysis, and a mixture formed of 167.87 g of demineralized water and 0.604 g of 70% methanesulfonic acid is added to the water at about 50° C. The organic solvent (ethyl acetate) is distilled off under vacuum.

[0120] A stable milky dispersion is obtained with a solids content of 40.4% by weight.

[0121] Example 8 Blocking agent (iii) 5-methyl-3-heptanone oxime In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following is charged with stirring under a nitrogen atmosphere at room temperature: - 70.0 g (0.22013 eq.) of Polurgreen AD 01; - 12.5 g of ethyl acetate; - 29.71 g (0.03962 equivalents) of pre-melted polyethylene glycol MW1500.

[0122] The reaction temperature is raised to 70° C. and maintained within the range of 70° C. to 75° C. for about 2 hours until the free NCO groups still present are determined to give a value of 6.7% by weight.

[0123] Next, 25.22 g (0.1761 equivalents) of 5-methyl-3-heptanone oxime is added dropwise over about 1 hour, while taking care not to allow the reaction temperature to exceed 70°C.

[0124] After 1 hour of reaction, FTIR analysis confirms that the prepolymer has only the last traces (0.139%) of NCO groups, and at about 60° C., 0.392 g (0.02 equivalents) of dimethylethanolamine is added.

[0125] After 1 hour of reaction, the disappearance of the NCO groups is confirmed by FTIR analysis, and a mixture formed of 175.94 g of demineralized water and 0.604 g of 70% methanesulfonic acid is added to the water at about 50° C. The organic solvent (ethyl acetate) is distilled off under vacuum.

[0126] A stable milky dispersion is obtained with a solids content of 40.3% by weight.

[0127] Example 9 Blocking agent 2-isopropyl-1H-imidazole In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following is charged with stirring under a nitrogen atmosphere at room temperature: - 100 g (0.518 equivalents) of Desmodur® Ultra N 3300 with an NCO content of 23%; - 19.42 g (0.026 eq.) of pre-melted methoxy PEG 750.

[0128] The reaction temperature is raised to 80° C. and maintained for approximately 1 hour until the free NCO groups still present are determined by titration to a value of 17.4% by weight.

[0129] It is then cooled to 70° C. and 34.1 g (0.310 equivalents) of 2-isopropyl-1H-imidazole are added in portions over 20 minutes at a temperature range comprised between 70° C. and 75° C. After 15 minutes of reaction, the free NCO groups still present are determined by titration to give a value of 5.5%.

[0130] 17.6 g (0.182 eq.) of tetraethylene glycol is added in 20 min to allow the reaction to proceed. After 1 h of reaction, FTIR analysis confirms the disappearance of the NCO groups. It is then cooled to about 50° C. and 256.7 g of demineralized water is added with stirring.

[0131] A stable milky dispersion is obtained with a solids content of 38.5% by weight.

[0132] Example 10 Blocking agent 2-ethyl-4-methylimidazole In a glass flask equipped with an internal thermometer, stirrer, and condenser, the following is charged with stirring under a nitrogen atmosphere at room temperature: - 100 g (0.518 equivalents) of Desmodur® Ultra N 3300 with an NCO content of 23%; - 19.42 g (0.026 eq.) of pre-melted methoxy PEG 750.

[0133] The reaction temperature is raised to 80° C. and maintained for approximately 1 hour until the free NCO groups still present are determined by titration to a value of 17.4% by weight.

[0134] It is then cooled to 70° C. and 34.1 g (0.310 equivalents) of 2-ethyl-4-methylimidazole are added in portions over 20 minutes at a temperature range comprised between 70° C. and 75° C. After 15 minutes of reaction, the free NCO groups still present are determined by titration to give a value of 5.5%.

[0135] 17.6 g (0.182 eq.) of tetraethylene glycol is added in 20 min to allow the reaction to proceed. After 1 h of reaction, FTIR analysis confirms the disappearance of the NCO groups. It is then cooled to about 50° C. and 256.6 g of demineralized water is added with stirring.

[0136] A stable milky dispersion is obtained with a solids content of 38.4% by weight.

[0137] Composition stability testing The three oximes (i), (ii), (iii) of the subject invention were used in typical compositions (see Examples 1, 2, 3) and each product was tested in water to evaluate its performance in comparison with current commercially available products.

[0138] Four tests were performed: Example 20A: (i) a composition comprising 2-pentanone oxime; Example 21A: (ii) a composition comprising 4-methylpentan-2-one oxime; Example 22A: (iii) a composition comprising 5-methyl-3-heptanone oxime; - Example 31A: A composition comprising a mixture of oximes (i) to (iii).

[0139] To evaluate water stability, stability studies were performed using a Turbiscan Tower apparatus, which is designed to analyze destabilization mechanisms in concentrated dispersion media, thus providing accelerated aging testing for unstressed real products.

[0140] The experimental conditions are shown in Table 4 below.

[0141] [Table 4]

[0142] The Turbiscan analysis reports are shown in Figures 5, 6, 7, 8, 9, and 10.

[0143] All four formulations prepared were stable as they did not show any settling. The graphs of backscattering change ΔBS (%) versus sample height (mm) reported in Figures 5, 6, 7, and 8 show straight lines with a slope close to zero. The TSI (degree of destabilization) versus time at 40°C in Figure 10 is less than 2 for all four tests over the entire 4 day analysis period.

[0144] Figure 10 shows the backscattering change ΔBS(%) versus time at 40°C. ΔBS(%) is less than 1% for all four samples, confirming the stability of the four products. Visually, the sample of Example 31A is more translucent and grainier than the other three samples. The positive slope of the backscattering change % is believed to be due to the finely dispersed crystals and improved solution homogeneity, which results in better light reflection.

[0145] Fabric performance evaluation Fabric application test The base + isocyanate compositions have good yields, comparable to and sometimes superior to the reference composition (Comparative Example 5, MEKO blocked isocyanate).

[0146] The percentages given below are percentages by weight of the individual component relative to the total weight of the formulation, unless otherwise specified.

[0147] How to treat fabric with foulard (padding method) The treatment and evaluation of the treated fabrics involves three steps: 1. Preparation of Protectant Solution 2. Substrate treatment 3.Performance evaluation by AATCC test

[0148] 1. Preparation of Protectant Solution The wetting solution used in the padding method is obtained by diluting the textile protectant solution combined with the crosslinker. The mixture between the two components usually has a ratio comprised between 90:10 and 80:20 of protectant and crosslinker, respectively. Before treatment, it is diluted with distilled water to a concentration comprised between 30 g / L and 100 g / L. Depending on the fabric or leather to be treated and the type of protectant to be applied, more or less diluted solutions are used (for example, for cotton, a higher weight is used compared to polyester or polyamide; as a further example, for fluorinated products, a lower weight is required compared to non-fluorinated products).

[0149] 2. Substrate treatment (I) Cut the substrate (leather or fabric, e.g., cotton, polyester, polyamide, etc.) to dimensions of approximately 60 cm x 20 cm; (II) weighing the dried substrate on an analytical balance; (III) Turn on the Foulard machine (Figure 11; model FL500, manufacturer Off.Electromechanical Gavazzi) and set the roller pressure to 3 bar and the rotation speed to 0.60 cm / min; (IV) Attaching a reservoir for wetting solution containing the preservative to the front of the foulard machine and inserting the wetting solution (volume contained in 0.5 liter to 1 liter); (V) immersing the substrate in a bath of wetting solution, then starting the rollers of the foulard machine and inserting the substrate between the rollers; (VI) in a second step, the substrate is slid off the rollers, removed and reintroduced between the two rollers (without passing the substrate through a bath with the wetting solution); (VII) The wetted substrate is weighed to be able to estimate the amount of wetting solution remaining on the substrate (substrate pick-up rate) according to the following formula: Capture rate = ((Final base material weight - Initial base material weight) / Initial base material weight) * 100 (VIII) A drying step is performed by inserting the substrate into a 120° C. oven for 1.5 minutes; (IX) carrying out a crosslinking step (curing) by inserting the substrate into an oven at 150° C. for 3 minutes; (X) The dried substrate is removed and an evaluation test is carried out.

[0150] 3.Performance evaluation by AATCC test Tests that are typically performed to assess the yield of treated substrates are as follows:

[0151] A.AATCC22: Spray test The treated substrate is placed under the funnel at a 45° angle and 250 ml of deionized water is poured through the funnel. The wettability and resistance of the treated substrate are then evaluated according to the AATCC22 evaluation method.

[0152] The results of the tests carried out according to the AATCC22-Spray test are summarized in Table 5 below.

[0153] [Table 5] Material: Cotton polyamide Process: Application method: Padding (P=3bar) Drying: 120℃ / 1.5 minutes Crosslinking: 150℃ / 3 minutes Required test: Spray test (in accordance with AATCC22) result:

[0154] [Table 5.A]

[0155] [Table 5.B]

[0156] From the above Tables 5.A and 5.B, the following conclusions can be drawn:

[0157] Non-fluorinated resin products applied without blocked isocyanates show poor resistance to washing both for cotton and polyamide: the photographic index drops to 70 / 80 after four washes for cotton and to 80 after six washes for polyamide.

[0158] All new products made with non-fluorinated base and isocyanates blocked with oximes (i), (ii), (iii) and oxime mixture (iv) show similar water repellency properties to MEKO blocked product B after 4 washes. The water repellency properties are consistent over many washes, thereby confirming that the subject products of the present invention are effective crosslinkers. The effectiveness of the subject products of the present invention is also confirmed by the good performance despite the lower NCO content compared to the standard MEKO blocked product.

[0159] Further tests carried out at lower temperatures (100°C drying and 120°C crosslinking) using (iii) 5-methyl-3-heptanone oxime as blocking agent show slightly higher water repellency properties (spray test) compared to formulations containing MEKO blocked isocyanates. In this regard, see Table 6 below, where product C is a fluorinated resin (see Example 11 in this regard).

[0160] [Table 6] Material: Cotton polyamide polyester Process: Application method: Padding (P=3bar) Drying: 100℃ / 1.5 minutes Crosslinking: 120℃ / 3 minutes Test: Spray test (AATCC22) result:

[0161] [Table 6.A]

[0162] [Table 6.B]

[0163] [Table 6.C]

[0164] Similar results in terms of stability and water repellency were obtained using 2-isopropyl-1H-imidazole Example 9 and 2-ethyl-4-methylimidazole Example 10 as blocking agents.

[0165] B.AATCC118:Oil repellency Drops of oil with different surface tensions are applied to the treated substrate. After 30 seconds the oil drop is removed and the absorption of the oil drop by the treated surface is evaluated. The oil repellency grade is determined as the highest grade tested that is not completely absorbed within 30 seconds. Table 7 below shows the oil grades that were applied:

[0166] [Table 7]

[0167] The tests performed are reported in Table 8.

[0168] [Table 8] Material: Cotton polyamide polyester Process: Application method: Padding (P=3bar) Drying: 120℃ / 1.5 minutes Crosslinking: 150℃ / 3 minutes Required test: AATCC118 (oil repellency) result:

[0169] [Table 8.A]

[0170] [Table 8.B]

[0171] [Table 8.C]

[0172] From the above tables 8.A, 8.B and 8.C the following conclusions can be drawn:

[0173] Tests carried out with isocyanates blocked with oximes (i)-(iii) and their mixtures (iv) formulated with product C (fluorinated resins) show that for the same materials (cotton, polyamide, polyester), the properties evaluated by AATCC method 118 are similar and equivalent to those obtained with product D, the reference product containing MEKO as blocking agent.

[0174] C.AATCC193: Water repellency Droplets of water / isopropyl alcohol mixtures (IPA; isopropyl alcohol) with different ratios and different surface tensions are applied to the treated substrate. After 10 seconds, the drops are removed and the absorption of the drops by the treated surface is evaluated. The water repellency grade is determined as the highest grade tested that is not completely absorbed within 10 seconds. Table 9 below shows the water / IPA solutions used:

[0175] [Table 9]

[0176] The tests performed are reported in Table 10.

[0177] [Table 10] Material: Cotton polyamide polyester Process: Application method: Padding (P=3bar) Drying: 120℃ / 1.5 minutes Crosslinking: 150℃ / 3 minutes Required test: AATCC193 (water resistance / isopropyl alcohol resistance) result:

[0178] [Table 10.A]

[0179] [Table 10.B]

[0180] [Table 10.C]

[0181] From the above tables 10.A, 10.B and 10.C the following conclusions can be drawn:

[0182] Tests carried out on isocyanates blocked with oximes (i)-(iii) and their mixtures (iv) formulated with product C (fluorinated resin) show that the properties evaluated by the AATCC 193 method are similar and equivalent to those obtained with product D, the reference product containing MEKO as blocking agent.

[0183] Example 11 Fluorinated resins and methods for their preparation. The composition may comprise, in addition to said oximes (i)-(iv) or said imidazole compound of general formula (I), a polyacrylate consisting of several (meth)acrylic acid esters, and optionally further components selected from paraffin waxes and polysiloxanes. The overall composition is suitably used for the treatment of substrates such as fabrics or leather to impart hydrophobicity, or hydrophobic / oleophobic properties, if the polyacrylate is functionalized with fluorinated chains.

[0184] Preferably, the polyacrylate is obtained by copolymerization of the following monomer units (a) to (d): (a) 0.1% to 90% by weight of one or more acrylic or methacrylic monomers of the following general formula: Rf-Rh-OCOC(R5)=CH2 (In the formula, R5 is a methyl or hydrogen group; Rf is a linear or branched perfluorinated alkyl group having 1 to 6 carbon atoms, preferably 4 to 6 carbon atoms, - Rh(CH2) n group, where n is an integer between 1 and 6, preferably between 2 and 4. (b) 0.1% to 80% by weight of one or more acrylic or methacrylic monomers of general formula (II) Rz-OCOC(R5)=CH2(II) (In the formula, Rz is a linear or branched benzyl or alkyl group containing 1 to 30 carbon atoms; - R5 is a methyl or hydrogen group. (c) 1% to 20% by weight of at least one acrylic or methacrylic functional group and a compound represented by the general formula R 2 -OCOC(R5)=CH2(wherein, R 2 one or more monomers having at least one carboxylic acid function of the formula (COOH)-(Rh)m-, where Rh and R5 are defined above and m can assume the value 0 or 1, or itaconic acid, (d) 0.1% to 15% by weight of one or more monomers having at least one vinyl functional group; (e) 1% to 20% by weight of one or more acrylic or methacrylic monomers of the following general formula: Ry-OCOC(R5)=CH2 (In the formula, Ry is the R-[Si(CH3)2O]l-Si(CH3)2-(Rh)m- group, where l is an integer comprised between 2 and 30, R is a linear or branched alkyl group having a number of carbon atoms between 1 and 20, Rh and m are as defined above, - R5 is a methyl or hydrogen group. (f) 0 to 15% by weight of one or more acrylic or methacrylic monomers of the following general formula: Rz-OCOC(R5)=CH2 (In the formula, Rz is -R 5 A -(Rh)m- group, where R5 is a hydroxyl or epoxy group and m is defined above.

[0185] Hereinafter, for the sake of brevity, "(meth)acrylate" or similar terms will be taken to mean "acrylate or methacrylate."

[0186] The synthesis of the (meth)acrylate polymers is carried out in two distinct steps: - homogenization of the mixture obtained by combining (meth)acrylic monomers, surfactants, water, and / or organic solvents; - followed by polymerization of the previously homogenized mixture.

[0187] The monomer mixture is heated, preferably in the presence of a solvent, until it is completely melted. The mixture is dispersed in hot water at 70 ° C containing a suitable surfactant and stirred vigorously, for example using a Turrax. In a subsequent step, high-pressure homogenization (for example, 400 bar and a temperature of 65-75 ° C) is carried out using a Manton-Gaulin type homogenizer. A radical initiator, optionally dissolved or dispersed in water, is then added to the resulting mixture. The polymerization reaction is carried out at a temperature of 60-70 ° C for several hours until no monomer remains.

[0188] Advantageously, for all compounds that are the subject of the present invention, the unblocking temperatures are not particularly high.

[0189] This aspect is of application advantage and is particularly important in terms of optimizing energy consumption and increasing process productivity.

[0190] Advantageously, for all compounds that are the subject of the present invention, the difference in unblocking temperature makes it possible to obtain a range of flexibility necessary, for example, for optimizing the processes that use such compositions.

Claims

1. A composition comprising or consisting of: - isocyanates blocked with a blocking agent selected from the group consisting of: (i) optionally 2-pentanone oxime; (ii) 4-methylpentan-2-one oxime; (iii) 5-methyl-3-heptanone oxime; and (iv) a mixture of two or more of (i) to (iii); Optionally one or more technical additives.

2. The composition of claim 1 , wherein the mixture (iv) comprises (iii) 5-methyl-3-heptanone oxime in combination with: (i) 2-pentanone oxime; and / or (ii) 4-methylpentan-2-one oxime.

3. In the mixture (iv), - (iii):(i) or (iii):(ii) in a weight ratio comprised between 20:1 and 1:20, preferably comprised between 10:1 and 1:10, more preferably comprised between 5:1 and 1:5; or A composition according to claim 2, in which the weight ratio [(iii)]:[(i)+(ii)] is comprised between 20:1 and 1:20, preferably between 10:1 and 1:10, and more preferably between 5:1 and 1:

5.

4. The composition according to any one of claims 1 to 3, wherein the (i) 2-pentanone oxime is not obtained by an ammoxidation reaction.

5. The composition according to any one of claims 1 to 4, wherein the blocked isocyanate - ionic or non-ionic - is selected from the group consisting of: (a) 1,5-pentamethylene diisocyanate (PDI) and its polymers, preferably trimers, optionally of bio-based origin; (b) toluene diisocyanate (TDI) and its adducts, preferably TDI trimer; (c) polyisocyanates derived from hexamethylene diisocyanate (HDI) obtained by trimerization, biuretization, and / or allophanatization processes; (d) polyisocyanates derived from isophorone diisocyanate (IPDI) obtained by trimerization, biuretization, and / or allophanatization processes; (e) 4,4'-methylenedicyclohexyl diisocyanate (H12MDI); (f) trimethylhexamethylene diisocyanate (TMDI); (g) 1,4-cyclohexyl diisocyanate (CHDI); (h) tetramethylxylene diisocyanate (TMXDI); and (i) Any mixture of two or more selected from (a) to (h).

6. The composition of claim 5, wherein the blocked isocyanate comprises or consists of hexamethylene 1,6-diisocyanate trimer.

7. 6. The composition of claim 5, wherein the blocked isocyanate comprises or consists of the reaction product of trimethylolpropane and a mixture of isomers of 2,4 toluene diisocyanate and 2,6 toluene diisocyanate, preferably in a weight ratio of 80:

20.

8. 8. The composition of claim 1, wherein the composition is an aqueous suspension or dispersion.

9. 9. The composition of any one of claims 1 to 8, wherein the composition does not include methyl ethyl ketoxime (MEKO).

10. Use of the following as blocking agents for isocyanates: (i) optionally 2-pentanone oxime; (ii) 4-methylpentan-2-one oxime; (iii) 5-methyl-3-heptanone oxime; or (iv) A mixture of two or more of (i) to (iii).

11. The use according to claim 10, wherein the mixture (iv) comprises (iii) 5-methyl-3-heptanone oxime in combination with: (i) 2-pentanone oxime; and / or (ii) 4-methylpentan-2-one oxime.

12. In the mixture (iv), - (iii):(i) or (iii):(ii) in a weight ratio comprised between 20:1 and 1:20, preferably comprised between 10:1 and 1:10, more preferably comprised between 5:1 and 1:5; or The use according to claim 11, wherein the weight ratio [(iii)]:[(i)+(ii)] is comprised between 20:1 and 1:20, preferably between 10:1 and 1:10, more preferably between 5:1 and 1:

5.

13. 13. The use according to any one of claims 10 to 12, comprising the deblocking of the isocyanate from the blocking agent in the water and / or oil repellent treatment of fabrics or leather.

14. 14. The use according to any one of claims 10 to 13, wherein the blocked isocyanate comprises or consists of hexamethylene 1,6-diisocyanate trimer.

15. 14. Use according to any one of claims 10 to 13, wherein the blocked isocyanate comprises or consists of the reaction product of trimethylolpropane with a mixture of the isomers of 2,4 toluene diisocyanate and 2,6 toluene diisocyanate, preferably in a weight ratio of 80:20 said isomers.

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