FLUOROCHEMICAL COMPOSITION FOR TREATMENT OF A FIBROUS SUBSTRATE

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Fluorochemical composition for rendering fibrous substrates oil repellent, water repellent, and/or stain or soil repellent. The composition comprises a dispersion or a solution of a fluorinated compound which comprises the reaction product of the following: (i) one or more fluorinated polyethers according to the formula: RfQTk   (I) wherein Rf represents a monovalent perfluorinated polyether group having a number average molecular weight of at least 750 g/mol, Q represents a chemical bond or a divalent or trivalent organic linking group, T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2; (ii) one or more polyoxyalkylene diols; (iii) one or more short chain perfluoroalkyl alcohols; (iv) one or more isocyanate component selected from a polyisocyanate compound that has at least 3 isocyanate groups or a mixture of polyisocyanate compounds wherein the average number of isocyanate groups per molecule is more than 2; (v) optionally one or more isocyanate blocking groups; and (vi) optionally one or more co-reactants capable of reacting with an isocyanate group. Also, a method of applying such composition to substrates, e.g., fibrous substrates.

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Description
FIELD OF INVENTION

The present invention relates to a fluorochemical composition for rendering fibrous substrates oil repellent, water repellent, and/or stain or soil repellent. Additionally, the invention also relates to a method of treating the fibrous substrate with the fluorochemical composition.

BACKGROUND

Compositions for making substrates, in particular fibrous substrates, such as textile, oil and water repellent have been long known in the art. When treating fibrous substrates and in particular textile such as apparel, it is desired that the textile retains its look and feel as much as possible. Therefore, the composition should normally not contain components that would affect the look of the product, i.e., the treatment should be substantially invisible to the unaided human eye. Also, the feel of the substrate should preferably be substantially unaffected. Typically this means that only low amounts of the solids of the composition can be applied. Accordingly, an oil- and/or water repellent composition should be highly effective in rendering a substrate repellent.

Commercially available oil- and/or water repellent compositions are typically based on fluorinated compounds that have a perfluorinated aliphatic group. Such compositions are also described in for example U.S. Pat. No. 5,276,175 and EP 435 641. The commercial success of this type of composition can be attributed to their high effectiveness. Fluorinated compounds based on perfluorinated ether moieties have also been described in the prior art for rendering fibrous substrates oil- and/or water repellent. For example, perfluorinated polyether compounds have been disclosed in EP 1 038 919, EP 273 449, JP-A-04-146917, JP-A-10-081873, U.S. Pat. Nos. 3,536,710, 3,814,741, 3,553,179, and 3,446,761. It was found that previously disclosed compositions based on perfluorinated polyether compounds may not be very effective in rendering a fibrous substrate oil- and/or water repellent.

The desire to find fluorochemical compositions based on a perfluorinated polyether compound that can provide good to excellent oil- and/or water-repellency properties to a fibrous substrate led to the inventions disclosed in U.S. Patent Publication Nos. 2004/0077237 and 2004/0077238. However, such compositions are reliant upon a high level of perfluorinated polyether compound and/or high level of isocyanate blocking agent. Perfluorinated polyether compounds are relatively expensive and isocyanate blocking agents may inhibit oily stain release.

Preferably, the fluorochemical composition is capable of providing durable oil- and/or water repellency properties to a fibrous substrate such that a treated fibrous substrate can substantially maintain the repellency properties even after several washing cycles. Preferably a fibrous substrate treated with the fluorochemical composition has a soft feel, preferably the feel of a treated fibrous substrate is either the same or softer compared to the untreated fibrous substrate. It is a further desire that the fluorochemical compositions can be easily and efficiently manufactured and used at a low cost. It is further desired to find compositions that have environmentally beneficial properties.

SUMMARY OF THE INVENTION

The present invention provides fluorochemical compositions for imparting oil repellency, water repellency, stain release, and soil release to fibrous substrates. Compositions of the invention provide a surprising and heretofore unachieved combination of relatively low cost with durable high performance.

The present invention provides in one aspect a fluorochemical composition comprising a dispersion or a solution of a fluorinated compound, wherein said fluorinated compound comprises the reaction product of a combination of reactants comprising:

    • (i) one or more fluorinated polyethers according to the formula:


RfQTk  (I)

      • wherein Rf represents a monovalent perfluorinated polyether group having a number average molecular weight of at least 750 g/mol, Q represents a chemical bond or a divalent or trivalent organic linking group, T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2;
    • (ii) one or more polyoxyalkylene diols;
    • (iii) one or more short chain perfluoroalkyl alcohols
    • (iv) one or more isocyanate component selected from a polyisocyanate compound that has at least 3 isocyanate groups or a mixture of polyisocyanate compounds wherein the average number of isocyanate groups per molecule is more than 2
    • (v) optionally one or more isocyanate blocking groups; and
    • (vi) optionally one or more co-reactants capable of reacting with an isocyanate group.
      In fluorochemical urethanes of the invention less than about 15%, preferably from about 2 to about 8%, of the isocyanate groups are reacted with perfluorinated polyether; less than about 15%, preferably from 0 to about 10%, of the isocyanate groups are reacted with isocyanate blocking group; more than about 5%, preferably from about 10 to about 40%, of the isocyanate groups are reacted with polyoxyalkylene diol; and more than about 35%, preferably from about 50 to about 75%, of the isocyanate groups are reacted with short-chain perfluoroalkyl alcohol.

The invention further provides a method of treatment of a fibrous substrate with the fluorochemical composition whereby oil- and/or water repellent properties are provided to the substrate. The fluorochemical composition of the present invention can provide good to excellent repellency properties to the substrate. Moreover, durable oil- and/or water repellency properties can be obtained. The fluorochemical compositions may further provide soil repellency as well as soil or stain release properties. The term “soil and/or stain release” is used to mean that a treated substrate that becomes soiled or stained can be more easily cleaned in for example a home laundering than an untreated substrate that becomes soiled or stained. Soil/stain repellency on the other hand refers to the ability of the treated substrate to repel soil thereby reducing soiling or staining of the substrate.

Generally, the fibrous substrate will retain a soft feel after treatment with the fluorochemical composition.

Also, the fluorochemical compositions of the present inventions are generally environmentally friendly in that compositions can be obtained that are substantially free of fluorochemical components that eliminate slowly from the body of living organisms. Moreover, it is believed that fluorochemical degradation products that may form likewise eliminate well from the body of living organisms. In particular, indications show that the fluorinated polyether compounds that have a perfluorinated polyether moiety having a molecular weight of at least 750 g/mol and perfluorinated polyether degradation products that may form therefrom would eliminate more effectively from the body of living organisms. In particular, there are indications that fluorinated polyether compounds having a fluorinated polyether moiety derivable from a polycondensation of hexafluoropropylene oxide and having a molecular weight of at least 750 g/mol would more effectively eliminate from the body of living organisms compared to long chain perfluoroaliphatic compounds.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS OF THE INVENTION

As discussed above, the fluorochemical composition of the invention comprises a dispersion or a solution of a fluorinated compound, wherein said fluorinated compound comprises the reaction product of a combination of reactants comprising:

    • (i) one or more fluorinated polyethers according to the formula:


RfQTk  (I)

      • wherein Rf represents a monovalent perfluorinated polyether group having a number average molecular weight of at least 750 g/mol, Q represents a chemical bond or a divalent or trivalent organic linking group, T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2;
    • (ii) one or more polyoxyalkylene diols;
    • (iii) one or more short chain perfluoroalkyl alcohols;
    • (iv) one or more isocyanate component selected from a polyisocyanate compound that has at least 3 isocyanate groups or a mixture of polyisocyanate compounds wherein the average number of isocyanate groups per molecule is more than 2;
    • (v) optionally one or more isocyanate blocking group; and
    • (vi) optionally one or more co-reactants capable of reacting with an isocyanate group.

Fluorinated Polyether

The fluorinated compound used in the fluorochemical composition is obtainable by reacting an isocyanate component and optional co-reactants with a fluorinated polyether according to formula (I) that has an isocyanate reactive group:


RfQTk  (I)

wherein Rf represents a monovalent perfluorinated polyether group, Q represents a chemical bond or a divalent or trivalent non-fluorinated organic linking group, T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2.

From about 2% to about 15%, preferably from about 2% to about 8%, of the isocyanate groups will be reacted with perfluorinated polyether. If lesser isocyanate is so reacted, the resultant coating may tend to be too stiff and to be deficient in performance. If more isocyanate is so reacted, the resultant composition will tend to be more expensive.

The perfluorinated polyether moiety Rf of the fluorinated polyether of formula (I) preferably corresponds to the formula:


Rf1ORf2 (Rf3)q  (II)

wherein Rf1 represents a perfluorinated alkyl group, Rf2 represents a perfluorinated polyalkyleneoxy group consisting of perfluorinated alkyleneoxy groups having 1, 2, 3, or 4 carbon atoms or a mixture of such perfluorinated alkylene oxy groups, Rf3 represents a perfluorinated alkylene group, and q is 0 or 1. The perfluorinated alkyl group Rf1 in formula (II) may be linear or branched and may comprise 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. A typical perfluorinated alkyl group is CF3CF2CF2—. Rf3 is a linear or branched perfluorinated alkylene group that will typically have 1 to 6 carbon atoms, for example, —CF2— or —CF(CF3)—. Examples of perfluoroalkylene oxy groups of perfluorinated polyalkyleneoxy group Rf2 include:

    • —CF2CF2O—,
    • —CF(CF3)CF2O—,
    • —CF2CF(CF3)O—,
    • —CF2CF2CF2O—,
    • —CF2O—,
    • —CF(CF3)O—, and
    • —CF2CF2CF2CF2O—
      The perfluoroalkyleneoxy group may be comprised of the same perfluoroalkylene oxy units or of a mixture of different perfluoroalkylene oxy units. When the perfluoroalkyleneoxy group is composed of different perfluoroalkylene oxy units, they can be present in a random configuration, alternating configuration or they can be present as blocks. Typical examples of perfluorinated polyalkylene oxy groups include:
    • [CF2CF2O]r—;
    • —[CF(CF3)CF2O]n—;
    • —[CF2CF2O]i[CF2O]j—; and
    • —[CF2CF2O]l[CF(CF3)CF2O]m—;
      wherein r is an integer of 4 to 25, n is an integer of 3 to 25, and i, l, m, and j each are integers of 2 to 25. A preferred perfluorinated polyether group that corresponds to formula (II) is CF3CF2CF2O[CF(CF3)CF2O]nCF(CF3)— wherein n is an integer of 3 to 25. This perfluorinated polyether group has a molecular weight of 783 when n equals 3 and can be derived from an oligomerization of hexafluoropropylene oxide. Such perfluorinated polyether groups are preferred in particular because of their benign environmental properties.

Examples of linking groups Q include organic groups that comprise aromatic or aliphatic groups that may be interrupted by O, N, or S and that may be substituted, alkylene groups, oxy groups, thio groups, urethane groups, carboxy groups, carbonyl groups, amido groups, oxyalkylene groups, thioalkylene groups, carboxyalkylene, and/or an amidoalkylene groups.

Examples of functional groups T include thiol, hydroxyl, and amino groups.

In a particular embodiment, the fluorinated polyether corresponds to the following formula (III):


Rf1[CF(CF3)CF2O]nCF(CF3)AQ1Tk  (III)

wherein Rf1 represents a perfluorinated alkyl group, e.g., a linear or branched perfluorinated alkyl group having 1 to 6 carbon atoms, n is an integer of 3 to 25, A is a carbonyl group or CH2, Q1 is a chemical bond or an organic divalent or trivalent linking group, for example, as mentioned for the linking group Q above, k is 1 or 2, and T represents an isocyanate reactive group, and each T may be the same or different. Particularly preferred compounds are those in which Rf1 represents CF3CF2CF2—. In accordance with a particular embodiment, the moiety -AQ1Tk is a moiety of the formula —COXRa(OH)k wherein k is 1 or 2, X is O or NRb with Rb representing hydrogen or an alkyl group of 1 to 4 carbon atoms, and Ra is an alkylene of 1 to 15 carbon atoms.

Representative examples of the moiety -AQ1Tk in above formula (III) include:

    • 1. —CONRcCH2CHOHCH2OH wherein Rc is hydrogen or an alkyl group of for example 1 to 4 carbon atoms;
    • 2. —CONH-1,4-dihydroxyphenyl;
    • 3. —CH2OCH2CHOHCH2OH;
    • 4. —COOCH2CHOHCH2OH; and
    • 5. —CONRd(CH2)mOH where Rd is hydrogen or an alkyl group of 1 to 6 carbons and m is 2, 3, 4, 6, 8, 10, or 11.

Compounds according to formula (III) can for example be obtained by oligomerization of hexafluoropropylene oxide which results in a perfluoropolyether carbonyl fluoride. This carbonyl fluoride may be converted into an acid, ester, or alcohol by reactions well known to those skilled in the art. The carbonyl fluoride or acid, ester, or alcohol derived therefrom may then be reacted further to introduce the desired isocyanate reactive groups according to known procedures. For example, EP 870 778 describes suitable methods to produce compounds according to formula (III) having desired moieties -AQ1Tk. Compounds having group 1 listed above can be obtained by reacting the methyl ester derivative of a fluorinated polyether with 3-amino-2-hydroxy-propanol. Compounds having the group 5 listed above can be obtained in a similar way by reacting with an amino-alcohol that has only one hydroxy function. For example 2-aminoethanol would yield a compound having the group 5 listed above with Rd being hydrogen and m being 2.

Still further examples of compounds according to above formula (I) are disclosed in European Patent No. 870 778 or U.S. Pat. No. 3,536,710.

It will be evident to one skilled in the art that a mixture of fluorinated polyethers according to formula (I) may be used to prepare the fluorinated polyether compound of the fluorochemical composition. Generally, the method of making the fluorinated polyether according to formula (I) will result in a mixture of fluorinated polyethers that have different molecular weights and such a mixture can be used as such to prepare the fluorochemical component of the fluorochemical composition. In a preferred embodiment, such a mixture of fluorinated polyether compounds according to formula (I) is free of fluorinated polyether compounds having a perfluorinated polyether moiety having a molecular weight of less than 750 g/mol or alternatively the mixture contains fluorinated polyether compounds having a perfluorinated polyether moiety having a molecular weight of less than 750 g/mol in an amount of not more than about 10% by weight relative to total weight of fluorinated polyether compounds, preferably not more than about 5% by weight and most preferably not more than about 1% by weight.

Polyoxyalkylene Diol

At least about 5%, preferably from about 10% to about 40%, of the isocyanate groups will be reacted with polyoxyalkylene diol. An illustrative example is polyoxypropylene diol having a number average molecular weight of from about 400 to about 2200. If less isocyanate is so reacted, the resultant coating may tend to have deficient durability and be deficient in performance. If more isocyanate is so reacted, the resultant composition will tend to gel making it more difficult to apply.

Alcohol

At least about 35%, preferably from about 50% to about 75%, of the isocyanate groups will be reacted with short chain perfluoroalkyl alcohol. If less isocyanate is so reacted, the resultant coating may tend to impart deficient oil repellency and water repellency. If more isocyanate is so reacted, the resultant composition will tend to impart poorer hand to the treated fabric substrate.

The short chain perfluoroalkyl alcohol has from 3 to 6 perfluorinated carbon atoms. In a preferred embodiment it comprises a C4F9— group. Specific examples of perfluoroalkyl alchohols which are suitable for use herein include:

    • C4F9SO2N(R)CH2CH2OH;
    • C4F9SO2N(R)CH2CH2O[CH2CH2O]tOH wherein t is 1 to 5;
    • C4F9SO2N(R)CH2CH2CH2NH2;
    • C4F9SO2N(R)CH2CH2SH;
    • C4F9SO2N(CH2CH2OH)2; and
    • C4F9SO2N(R)CH2CH2O(CH2)nOH wherein s is 2, 3, 4, 6, 8, 10, or 11
      wherein R is hydrogen or a lower alkyl of 1 to 4 carbons such as methyl, ethyl, and propyl.

Isocyanate

The isocyanate component for making the fluorinated compound of the fluorochemical composition is selected from a polyisocyanate having at least 3 isocyanate groups or a mixture of polyisocyanate compounds that on average has more than 2 isocyanate groups per molecule such as, for example, a mixture of a diisocyanate compound and a polyisocyanate compound having 3 or more isocyanate groups

The polyisocyanate compound may be aliphatic or aromatic and is conveniently a non-fluorinated compound. Aliphatic isocyantes are typically preferred as resultant compositions of the invention will be less subject to yellowing and will typically yield a softer finish on treated fibrous substrates.

Generally, the molecular weight of the polyisocyanate compound will be not more than 1500 g/mol. Examples include hexamethylenediisocyanate, 2,2,4-trimethyl-1,6-hexamethylenediisocyanate, 1,2-ethylenediisocyanate, dicyclohexylmethane-4,4′-diisocyanate, aliphatic triisocyanates such as 1,3,6-hexamethylenetriisocyanate, cyclic trimer of hexamethylenediisocyanate, and cyclic trimer of isophorone diisocyanate (isocyanurates); aromatic polyisocyanate such as 4,4′-methylenediphenylenediisocyanate, 4,6-di-(trifluoromethyl)-1,3-benzene diisocyanate, 2,4-toluenediisocyanate, 2,6-toluene diisocyanate, o, m, and p-xylylene diisocyanate, 4,4′-diisocyanatodiphenylether, 3,3′-dichloro-4,4′-diisocyanatodiphenylmethane, 4,5′-diphenyldiisocyanate, 4,4′-diisocyanatodibenzyl, 3,3′-dimethoxy-4,4′-diisocyanatodiphenyl, 3,3′-dimethyl-4,4′-diisocyanatodiphenyl, 2,2′-dichloro-5,5′-dimethoxy-4,4′-diisocyanato diphenyl, 1,3-diisocyanatobenzene, 1,2-naphthylene diisocyanate, 4-chloro-1,2-naphthylene diisocyanate, 1,3-naphthylene diisocyanate, and 1,8-dinitro-2,7-naphthylene diisocyanate and aromatic triisocyanates such as polymethylenepolyphenylisocyanate. Still further isocyanates that can be used for preparing the fluorinated compound include alicyclic diisocyanates such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate; aromatic tri-isocyanates such as polymethylenepolyphenylisocyanate (PAPI); cyclic diisocyanates such as isophorone diisocyanate (IPDI). Also useful are isocyanates containing internal isocyanate-derived moieties such as biuret-containing tri-isocyanates such as that available from Bayer as DESMODUR™ N-100, isocyanurate-containing tri-isocyanates such as that available from Huls AG, Germany, as IPDI-1890, and azetedinedione-containing diisocyanates such as that available from Bayer as DESMODUR™ TT. Also, other di- or tri-isocyanates such as those available from Bayer as DESMODUR™ L tri-(4-isocyanatophenyl)-methane (available from Bayer as DESMODUR™ R) and DDI 1410 (available from Henkel) are suitable.

Blocking Group

Further, the optional co-reactant may include an isocyanate blocking agent. The isocyanate blocking agent can be used alone or in combination with one or more other co-reactants described above.

Up to about 15%, preferably up to about 10%, of the isocyanate groups will be reacted with blocking agent.

Isocyanate blocking agents are compounds that upon reaction with an isocyanate group yield a group that is unreactive at room temperature with compounds that at room temperature normally react with an isocyanate but which group at elevated temperature reacts with isocyanate reactive compounds. For example, at elevated temperature the blocking group may be released from the blocked (poly)isocyanate compound thereby generating the isocyanate group again which can then react with an isocyanate reactive group. Blocking agents and their mechanisms have been described in detail in “Blocked isocyanates III.: Part. A, Mechanisms and Chemistry” by Douglas Wicks and Zeno W. Wicks Jr., Progress in Organic Coatings, 36 (1999), pp. 14-172.

Preferred blocking agents include arylalcohols such as phenols; lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam; and oximes such as formaldoxime, acetaldoxime, cyclohexanone oxime, acetophenone oxime, benzophenone oxime, 2-butanone oxime; or diethyl glyoxime. Further suitable blocking agents include bisulfite and triazoles.

Optional Co-Reactants

The organic compound will include one or more water solubilising groups or groups capable of forming water solubilising groups so as to obtain a fluorinated compound that can more easily be dispersed in water. Additionally, by including water solubilising groups in the fluorinated compound, beneficial stain release properties may be obtained on the fibrous substrate. Suitable water solubilising groups include non-ionic water solubilising groups. Preferrably organic compounds that have only one functional group capable of reacting with NCO-group and that further include a non-ionic water-solubilising group are used. Typical non-ionic water solubilising groups include polyoxyalkylene groups. Preferred polyoxyalkylene groups include those having 2 to 3 carbon atoms such as polyoxyethylene, polyoxypropylene, and copolymers thereof such as polymers having both oxyethylene and oxypropylene units. The polyoxyalkylene containing organic compound may include one functional group such as hydroxy or amino groups. Examples of polyoxyalkylene containing compounds include alkyl ethers of polyglycols such as, e.g., methyl or ethyl ether of polyethyleneglycol, hydroxy terminated methyl or ethyl ether of a random or block copolymer of ethyleneoxide and propyleneoxide, amino terminated methyl or ethyl ether of polyethyleneoxide.

The perfluoroaliphatic group included in the fluorinated compound and the co-reactant may then comprise a perfluoroaliphatic compound having one or more isocyanate reactive groups. By “perfluoroaliphatic groups” is meant groups that consist of carbon and fluorine without however including perfluorinated end groups of the perfluorinated moiety. The perfluoroaliphatic group contains 3 to 18 carbon atoms, preferably 3 to 6 carbon atoms, and most preferably is a C4F9— group. By including perfluoroaliphatic groups, in particular C4F9— groups in the fluorinated polyether compound, one can improve the solubility and/or dispersibility of the fluorinated polyether compound in the fluorochemical composition. Preferred fluorinated co-reactants will correspond to the formula:


(Rf4)xL(Y)y  (IV)

wherein Rf4 represents a perfluoroaliphatic group having 3 to 5 or 6 carbon atoms, L represents a non-fluorinated organic divalent or multivalent linking group such as, for example, organic groups that comprise alkylene, carboxy, sulfonamido, carbonamido, oxy, alkyleneoxy, thio, alkylenethio, and/or arylene. Y represents a functional group having a Zerewitinoff hydrogen such as, for example, hydroxy, amino, or thiol, and x is an integer of 1 to 20, for example, between 2 and 10, and y is 1 or 2. According to a particular embodiment, Rf4 is C4F9—, x is 1, and y is 1.

The condensation reaction to prepare the fluorinated compound of the fluorochemical composition can be carried out under conventional conditions well-known to those skilled in the art. Preferably the reaction is run in the presence of a catalyst and typically, the reaction will be carried out such that all isocyanate groups have been reacted and the obtained reaction product is free of isocyanate groups. Suitable catalysts include tin salts such as dibutyltin dilaurate, stannous octanoate, stannous oleate, tin dibutyldi-(2-ethyl hexanoate), stannous chloride; and others known to those skilled in the art. The amount of catalyst present will depend on the particular reaction, and thus it is not practical to recite particular preferred concentrations. Generally, however, suitable catalyst concentrations are from about 0.001 percent to about 10 percent, preferably about 0.1 percent to about 5 percent, by weight based on the total weight of the reactants. The condensation reaction is preferably carried out under dry conditions in a common organic solvent that does not contain Zerewitinoff hydrogens such as ethyl acetate, acetone, methyl isobutyl ketone, toluene, and fluorinated solvents such hydrofluoroethers and trifluorotoluene. Suitable reaction temperatures will be easily determined by those skilled in the art based on the particular reagents, solvents, and catalysts being used. While it is not practical to enumerate particular temperatures suitable for all situations, generally suitable temperatures are between about room temperature and about 120° C.

Fluorochemical urethanes of the invention are prepared from aliphatic polyisocyanate, wherein less than about 15%, preferably from about 2 to about 8%, of the isocyanate groups are reacted with perfluorinated polyether alcohol, less than about 15%, preferably from 0 to about 10%, of the isocyanate groups are reacted with isocyanate blocking group, more than about 5%, preferably from about 10 to about 40%, of the isocyanate groups are reacted with polyoxyalkylene diol, and more than about 35%, preferably from about 50 to about 75%, of the isocyanate groups are reacted with short-chain perfluoroalkyl alcohol.

In a particular embodiment, the fluorochemical composition may contain additionally a non-fluorinated organic compound, wherein the non-fluorinated organic compound is capable of improving relative to the fluorochemical composition without the non-fluorinated organic compound, the oil repellency or water repellency that can be achieved by the fluorochemical composition on a fibrous substrate or the durability of one or both of the repellency properties. Such non-fluorinated organic compounds are sometimes called extenders. Suitable extenders for use in the fluorochemical composition include non-fluorinated organic compounds that have one or more blocked isocyanate groups, so called blocked isocyanate compounds, or a carbodiimide compound. Preferred blocked isocyanate extenders are blocked polyisocyanates that at a temperature of less than about 150° C. are capable of reacting with an isocyanate reactive group, preferably through deblocking of the blocking agent at elevated temperature. Preferred blocking agents include arylalcohols such as phenols; lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam; oximes such as formaldoxime, acetaldoxime, methyl ethyl ketone oxime, cyclohexanone oxime, acetophenone oxime, benzophenone oxime, 2-butanone oxime, or diethyl glyoxime. Further suitable blocking agents include bisulfite and triazoles.

In a preferred embodiment of the invention, the blocked polyisocyanate may comprise the condensation product of a polyisocyanate, for example, a di- or triisocyanate, and a blocking agent.

The carbodiimide compound can be an aromatic or aliphatic carbodiimide compound and may include a polycarbodiimide. Carbodiimides that can be used have been described in, for example, U.S. Pat. Nos. 4,668,726, 4,215,205, 4,024,178, and 3,896,251, WO 93/22282, U.S. Pat. Nos. 5,132,028, 5,817,249, 4,977,219, 4,587,301, 4,487,964, 3,755,242, and 3,450,562. Particularly suitable carbodiimides for use in this invention include those corresponding to the formula (VII):


R1[N═C═NR3]uN═C═NR2  (VII)

wherein u has a value of 1 to 20, typically 1 or 2, R1 and R2 each independently represent a hydrocarbon group, in particular a linear, branched, or cyclic aliphatic group preferably having 6 to 18 carbon atoms, and R3 represents a divalent linear, branched, or cyclic aliphatic group.

The aliphatic carbodiimide extenders of formula VII can be synthesized in a 1-step process by reacting aliphatic diisocyanates with an aliphatic mono-isocyanate as a chain terminator at about 130 to about 170° C. in the presence of a phospholine oxide or other suitable carbodiimide formation catalyst. Preferably the reaction is carried out in the absence of solvents under inert atmosphere, but high-boiling non-reactive solvents such as methyl isobutyl ketone can be added as diluents. The mole ratio of diisocyanate to mono-isocyanate can be varied from about 0.5 to 10, preferably about 1 to 5.

Examples of aliphatic diisocyanates for the preparation of the carbodiimide compounds of formula (VII) include isophorone diisocyanate, dimer diacid diisocyanate, 4,4′ dicyclohexyl methane diisocyanate. Examples of mono-isocyanates are n.butyl isocyanate and octadecyl isocyanate. Representative examples of suitable carbodiimide formation catalysts are described in, e.g., U.S. Pat. Nos. 2,941,988, 3,862,989, and 3,896,251. Examples include 1-ethyl-3-phospholine, 1-ethyl-3-methyl-3-phospholine-1-oxide, 3-methyl-1-phenyl-3-phospholine-1-oxide, and bicyclic terpene alkyl or hydrocarbyl aryl phosphine oxide. The particular amount of catalyst used depends on the reactivity of the catalyst and the isocyanates being used. A concentration of about 0.2 to about 5 parts of catalyst per 100 g of diisocyanate is suitable.

In an alternative approach the aliphatic diisocyanates can be first reacted with monofunctional alcohols, amines, or thiols followed by carbodiimide formation in a second step.

The fluorochemical urethane is preferably delivered in combination with blocked isocyanate extender. The fluorochemical urethane and blocked isocyanate extender may be synthesized separately or, preferably, in the same reactor and may be applied to the textile yarns from organic solvent or, preferably, as aqueous emulsion. The fluorochemical urethane and blocked isocyanate extender may be emulsified separately and then blended or, preferably, their organic solutions may be combined and co-emulsified.

It has been unexpectedly found that such compounds provide a surprising combination of good performance at low cost as compared to previously known otherwise similar compounds made with higher proportions of perfluorinated polyether.

The fluorinated compound of the fluorochemical composition typically will have a molecular weight such that it is readily dissolved or dispersed in water or an organic solvent. Generally, the molecular weight of the fluorinated compound is not more than 100,000 g/mol, with a typical range being between 1500 g/mol and 60,000 g/mol. When a mixture of fluorinated compounds is used, the aforementioned molecular weights represent weight average molecular weights.

The fluorochemical composition comprises a dispersion or solution of the fluorinated compound in water or an organic solvent. As used herein, the term “dispersion” refers to both solid-in-liquid dispersions as well as liquid-in-liquid dispersions which are also called emulsions. Generally, the fluorochemical compositions will be diluted before treating fibrous substrates such that the amount of fluorinated compound contained in the treating composition is from about 0.01 to about 7% by weight, preferably from about 0.05 to about 3% by weight based on the total weight of the fluorochemical composition. Higher amounts of fluorinated compound, for example up to about 10% by weight may be used as well, particularly if the uptake of the fluorochemical composition by the substrate is low. Generally, the fluorochemical treating composition will be prepared by diluting a more concentrated fluorochemical composition to the desired level of fluorinated compound in the treating composition. The concentrated fluorochemical composition can contain the fluorinated compound in an amount of up to about 70% by weight, typically from about 10% by weight to about 50% by weight.

When the fluorochemical composition is in the form of a dispersion in water or an organic solvent, the weight average particle size of the fluorinated compound particles is preferably not more than about 400 nm, more preferably is not more than about 300 nm.

Most preferably, the fluorochemical composition is an aqueous dispersion of the fluorinated compound. Such dispersion may be non-ionic, anionic, cationic, or zwitterionic. The dispersion is preferably stabilised using non-fluorinated surfactants, such as non-ionic polyoxyalkylene, in particular polyoxyethylene surfactants, anionic non-fluorinated surfactants, cationic non-fluorinated surfactants, and zwitterionic non-fluorinated surfactants. Specific examples of non-fluorinated surfactants that can be used are nonionic types such as EMULSOGEN™ EPN 207 (Clariant) and TWEEN™ 80 (ICI), anionic types such as lauryl sulfate and sodium dodecyl benzene sulfonate, cationic types such as ARQUAD™ 12-50 (Akzo), ETHOQUAD™ 18-25 (Akzo) or amphoteric types such as lauryl amineoxide and cocamido propyl betaine. The non-fluorinated surfactant is preferably present in an amount of about 1 to about 25 parts by weight, preferably about 1 to about 50 parts by weight, based on 100 parts by weight of the fluorochemical composition.

Alternatively, a solution or dispersion of the fluorinated compound in an organic solvent can be used as the fluorochemical treating composition. Suitable organic solvents include alcohols such as isopropanol, methoxy propanol, and t.butanol, ketones such as isobutyl methyl ketone and methyl ethylketone, ethers such as isopropylether, esters such ethylacetate, butylacetate or methoxypropanol acetate, or (partially) fluorinated solvents such as HCFC-141b, HFC-4310 mee and hydrofluoroethers such as HFE-7100 or HFE-7200 available from 3M Company.

The fluorochemical composition may contain further additives such as buffering agent, agents to impart fire proofing or antistatic properties, fungicidal agents, optical bleaching agents, sequestering agents, mineral salts, and swelling agents to promote penetration.

In a preferred embodiment of the present invention, the fluorochemical composition will be free of or substantially free of perfluorinated polyether moieties having a number average molecular weight of less than 750 g/mol and/or perfluoroaliphatic groups of more than 5 or 6 carbons. By the term “perfluoroaliphatic groups” is meant groups consisting of carbon and fluorine without including perfluorinated end groups of the perfluorinated polyether moieties. By the term “substantially free of” is meant that the particular perfluorinated polyether moieties are present in amounts of not more than about 10% by weight, preferably not more than about 5% by weight, and most preferably not more than about 1% by weight based on the total weight of perfluorinated polyether moieties in the composition and that the particular perfluoroaliphatic groups having more than 5 or 6 carbons are present in amounts of not more than about 10% by weight, preferably not more than about 5% by weight, and most preferably not more than about 1% by weight based on the total weight of perfluoroaliphatic groups in the composition. Compositions that are free of or substantially free of these moieties or groups are preferred because of their beneficial environmental properties.

Treatment of Substrates

In order to affect treatment of the fibrous substrate the fibrous substrate is contacted with the fluorochemical composition of the invention. For example, the substrate can be immersed in the fluorochemical treating composition. The treated substrate can then be run through a padder/roller to remove excess fluorochemical composition and dried. The treated substrate may be dried at room temperature by leaving it in air or, preferably, be subjected to a heat treatment, for example, in an oven. This heat treatment is typically carried out at temperatures from about 50° C. to about 190° C. depending on the particular system or application method used. In general, a temperature of about 120° C. to about 170° C., in particular of about 150° C. to about 170° C. for a period of about 20 seconds to 20 minutes, is suitable. Alternatively, the chemical composition can be applied by spraying the composition on the fibrous substrate.

It was found that with fluorochemical compositions of this invention, surprisingly good to excellent oil, water repellent properties, and/or stain release properties on the fibrous substrate can be achieved. Also, it was observed that the repellency properties are durable, i.e., even after several washing cycles, the repellency properties can be substantially maintained. The compositions furthermore in many instances minimally affect the soft feel of the fibrous substrates.

The amount of the treating composition applied to the fibrous substrate is chosen so that a sufficiently high level of the desired properties are imparted to the substrate surface preferably without substantially affecting the look and feel of the treated substrate. Such amount is usually such that the resulting amount of the fluoropolymer on the treated fibrous substrate will be from about 0.05% to about 3% by weight, preferably from about 0.2 to about 1.5% by weight based on the weight of the fibrous substrate. The amount which is sufficient to impart desired properties can be determined empirically and can be increased as necessary or desired. According to a particularly preferred embodiment, the treatment is carried out with a composition and under conditions such that the total amount of perfluorinated polyether groups having a number average molecular weight of less than 750 g/mol and/or perfluoroaliphatic groups of more than 6 carbon atoms is not more than about 0.1%, preferably not more than about 0.05% by weight based on the weight of the fibrous substrate.

Fibrous substrates that can be treated with the fluorochemical composition include in particular textile and carpet. The fibrous substrate may be based on synthetic fibers, e.g., polyester, polyamide and polyacrylate fibers or natural fibers, e.g., cellulose fibers as well as mixtures thereof. The fibrous substrate may be a woven as well as a non-woven substrate.

The invention will now be further illustrated with reference to the following examples without the intention to limit the invention thereto. All parts and percentages are by weight unless stated otherwise.

EXAMPLES Test Methods

Water Repellency Test (WR)

The water repellency (WR) of a substrate was measured using a series of water/isopropyl alcohol test liquids and was expressed in terms of the WR rating of the treated substrate. The WR rating corresponded to the most penetrating test liquid that did not penetrate or wet the substrate surface after 10 seconds exposure, according to the WR rating scale and the test liquid compositions summarized in the table below. Substrates which were penetrated by a 2%/98% isopropyl alcohol/water blend, the least penetrating test liquid, were given a rating of 0, a treated substrate resistant to a 30%/70% isopropyl alcohol/water blend, but not to an 40%/60% blend, would be given a rating of 5, and so on.

Standard Water Repellency Test Liquids

Water Repellency Test Liquid Composition (Volume %) Rating # (WR) Isopropanol:Water 1  2:98 2  5:95 3 10:90 4 20:80 5 30:70 6 40:60 7 50:50

Oil Repellency (OR)

The oil repellency of a substrate was measured by the American Association of Textile Chemists and Colorists (AATCC) Standard Test Method No. 118-2002, which test was based on the resistance of a treated substrate to penetration by oils of varying surface tensions. Treated substrates resistant only to NUJOL™ mineral oil (the least penetrating of the test oils) were given a rating of 1, whereas treated substrates resistant to n-decane (the most penetrating of the test liquids) were given a rating of 6. Other intermediate values were determined by use of other pure oils or mixtures of oils, as shown in the following table.

Standard Oil Repellency Test Liquids

AATCC Oil Repellency Rating Number Compositions 1 NUJOL ™ Mineral Oil 2 NUJOL ™ Mineral Oil/n- Hexadecane 65/35 3 n-Hexadecane 4 n-Tetradecane 5 n-Dodecane 6 n-Decane

Laundering Procedure

The procedure set forth below was used to prepare treated substrate samples designated in the examples below as “5 Launderings”.

A 230 g sample of generally square, 400 cm2 to about 900 cm2 sheets of treated substrate was placed in a washing machine (SEARS KENMORE™ Model No. 110.26962500) along with a ballast sample (1.9 kg of 8 oz wash-load ballast fabric, from Textile Innovators/SDL Atlas, Windsor, N.C., in the form of generally square, hemmed 8100 cm sheets). A commercial detergent (75 g of TIDE™ Ultra Liquid deep cleaning formula, from Proctor and Gamble, Cincinnati, Ohio) was added and the washer was filled to high water level with hot water (41° C.±2° C.). The substrate and ballast load were washed 5 times using a 12-minute normal wash cycle.

The substrate and ballast were dried together in a conventional tumble drier at 65±5° C. during 45±5 minutes. Before testing, the substrates were conditioned at room temperature during about 4 hours.

“20 Launderings” or “30 Launderings” indicated that the substrate was washed for 20 or 30 times, respectively, according to the procedure above.

Stain Release Test—Woven Fabric

This test evaluates the release of forced-in oil-based stains from the treated fabric surface during simulated home laundering. Five drops of KAYDOL™ mineral oil (Witco Chemical Co.) were dropped onto the fabric surface in a single puddle and a separate puddle of 5 drops of MAZOLA corn oil was dropped on the fabric. The puddles were covered with glassine paper, and weighted with a five-pound weight each for 60 seconds. The weights and glassine paper were removed from the fabric. The fabric sample was hung for 15 to 60 minutes, and then washed and dried. Samples were evaluated against a rating board, and assigned a number from 1 to 8. An 8 represented total removal of the stain, where 1 was a very dark stain. Stain release values were determined using one stain challenge. A more detailed description of the test is written in the 3M's “Stain Release Test I” method (Document # 98-0212-0725-7).

Stain Release Test—Knit Fabric

This test was carried out similar to Stain Release Test—Woven fabric test above except using WELCH'S™ grape juice, 0.25 pound weights, TIDE™ powder soap, and the AATCC rating scale wherein a value “1” indicates very dark staining and “5” indicates no visible stain. Grape juice stain release values were assigned using the average rating of three stain challenges.

Textile Substrates

Textile substrates used for the evaluation of treatments of this invention were commercially available and are listed below:

    • Textile Substrate 1: Tan 100% cotton woven fabric, BRITISH KHAKI SUPER HIP, from Avondale Mills, Graniteville S.C.;
    • Textile Substrate 2: Olive polyester/cotton (65/35) woven fabric, EQUESTRIAN TWILL, from Avondale Mills, Graniteville S.C.; and
    • Textile Substrate 3: White 100% cotton jersey knit fabric, from Fruit of the Loom, Bowling Green, Ky.

Materials

Descriptor Formula/Structure Source ARCOL ™ Polypropylene oxide-based diol Bayer MaterialScience POLYOL (MW ~ 426) LLC, PPG-425 Pittsburgh, PA ARCOL ™ Polypropylene oxide-based diol Bayer MaterialScience POLYOL (MW ~ 763) LLC, PPG-725 Pittsburgh, PA ARCOL ™ Polypropylene oxide-based diol Bayer MaterialScience POLYOL (MW ~ 1000) LLC, PPG-1025 Pittsburgh, PA ARCOL ™ Polypropylene oxide-based diol Bayer MaterialScience POLYOL (MW ~ 2000) LLC, PPG-2025 Pittsburgh, PA ARQUAD ™ Dodecyltrimethylammonium chloride Akzo Nobel, Netherlands 12-50 ARQUAD ™ Di(hydrogenated Akzo Nobel, Netherlands 2HT-75 tallow)dimethylammonium chloride CARBOWAX ™ Methoxypolyethylene glycol Union Carbide, Danbury, MPEG-750 (MW ~750) CT, a subsidiary of Dow Chemical Company, Midland, MI DBTDL Dibutyltin dilaurate Sigma-Aldrich DESMODUR ™ Aliphatic polyisocyanate resin based on Bayer MaterialScience N 3300 hexamethylene diisocyanate (NCO content LLC, 21.8 ± 0.3%) Pittsburgh, PA DESMODUR ™ Aromatic polyisocyanate resin based on Bayer MaterialScience L 75 toluene diisocyanate, approximately 75% in LLC, ethyl acetate (NCO content 13.3 ± 0.4%) Pittsburgh, PA EA Ethyl acetate Sigma-Aldrich MEKO 2-Butanone oxime Sigma-Aldrich CH3C(═NOH)C2H5 WETAID ™ Nonionic wetting agent Noveon, Inc., Cleveland, NRW OH MONDUR ™ Aromatic polymeric isocyanate based on Bayer MR diphenylmethane-diisocyanate

(HFPO)k-alc: HFPO oligomer alcohols,

CF3CF2CF2O(CF(CF3)CF2O)nCF(CF3)CONHCH2CH2OH, consisting of a mixture of oligomers with different chain lengths. The indexes k and n are indicative of the mathematical average of the number of repeating HFPO-units and k=n+2. The (HFPO)7.7-alc was prepared essentially according to the same procedure as that for CF3CF2CF2O(CF(CF3)CF2O)6.8CF(CF3)CONHCH2CH2OH, or (HFPO)8.8-alc, as described in U.S. Patent Publication No. 2004/0077238, paragraph [0140] through paragraph [0145].

A. Synthesis of HFPO-Oligomer Alcohol and Diol 1. Synthesis of HFPO-Oligomer Alcohol ((HFPO)k-alc Several HFPO-oligomer alcohols ((HFPO)k-alc) were prepared according to the general procedure as given for the synthesis of CF3CF2CF2O(CF(CF3)CF2O)6.8CF(CF3)CONHCH2CH2OH, indicated in table 1 as (HFPO)8.8-alc.

A 1 liter 3-necked reaction flask was equipped with a stirrer, a condenser, a dropping funnel, a heating mantle and a thermometer. The flask was charged with 1000 g CF3CF2CF2O(CF(CF3)CF2O)6.8CF(CF3)COOCH3. The mixture was heated to 40° C. and 43.4 g ethanolamine was added via the dropping funnel, over a period of 30 minutes. The reaction mixture was kept at 65° C. during 3 hours. FTIR analysis indicated complete conversion. The end product could be purified as follows: 500 ml ethylacetate were added and the organic solution was washed with 200 ml HCL (1N), followed by 2 washings with 200 ml brine. The organic phase was dried over MgSO4. Ethylacetate was evaporated with waterjet vacuum, using a Buchi rotary evaporator. The product was dried at 50° C. during 5 hours, using oil pump vacuum (<1 mbar). An alternative purification step included evaporation of methanol, formed during reaction, via water jet vacuum, using a Buchi rotary evaporator (up to 75° C.=<100 mm Hg). Residual methanol was further removed with oil pump vacuum (up to 80° C., =<10 mbar).
The HFPO-oligomer alcohol (HFPO)8.8-alc obtained, was a yellow coloured oil, with medium viscosity. The structure was confirmed by means of NMR.

HFPO-oligomer alcohols with other chain lengths were prepared essentially according to the same procedure. MeFB SE: N-2-hydroxyethyl-N-methylperfluorobutylsulfonamide, C4F9SO2N(CH3)CH2CH2OH, was prepared according to PCT Publication Number WO 01/30873, Example 2 Part A. EXAMPLES 1 to 7

Synthesis of FC Urethane Mixture A

A solution of HFPO oligomer alcohol (HFPO)7.7-alc (15.56 grams, 11.76 meq hydroxyl), MeFBSE (77.84 grams, 218.03 mmole), ARCOL™ POLYOL PPG-1025 (62.26 grams, 124.77 meq hydroxyl), and CARBOWAX™ MPEG-750 (20.80 grams, 27.73 meq hydroxyl) in ethyl acetate (EA, 220 grams) was heated and 82.5 grams distillate allowed to escape. DESMODUR™ N3300 (77.87 grams, 401.42 meq isocyanate), ethyl acetate (EA, 30 grams), and dibutyltin dilaurate (DBDTL, 0.06 grams) were added sequentially, and then heated for 6 hours at 75° C. 2-Butanone oxime (MEKO, 18.89 grams, 217.10 mmole), ethyl acetate (EA, 90 grams), and toluene diisocyanate based adduct in organic solvent (DESMODUR™ L 75, 62.37 grams, 197.99 meq isocyanate) were added sequentially, heated for 1 hour at 75° C., then diluted with ethyl acetate to a final 640 grams.

FC Urethane Mixture A solids comprised 80 weight percent aliphatic fluorochemical urethane and 20 weight percent blocked aromatic isocyanate extender. Of the aliphatic isocyanates of FC Urethane Mixture A's fluorochemical urethane, 2.9% were reacted perfluorinated polyether alcohol, 4.8% with MEKO, 31.1% with polyoxyalkylene diol, 54.3% with short-chain perfluoroalkyl alcohol, and 6.9% with polyethylene glycol monomethyl ether. FC Urethane Mixture A contained 14.8% fluorine versus urethane solids and the fluorochemical urethane portion contained 18.5% fluorine versus urethane solids.

Preparation of Fluorochemical Emulsion A

Warm deionized water (375 grams, 40° C.) was poured into a rapidly stirred 40° C. solution of FC Urethane Mixture A (300 grams solution), ARQUAD™12-50 (2.40 grams), ARQUAD™ 2HT-75 (2.40 grams), and ethyl acetate (EA, 33.33 grams). The emulsion was stirred 20 minutes and then sonified for three minutes on a BRANSON™ Sonifier 450 (70/30 on/off cycling). Then the emulsion was heated to 50° C. as the ethyl acetate was removed under vacuum. The resulting emulsion was diluted with deionized water to a final 500 grams.

Textile Treatment

Three textile treatment baths were prepared by sequentially adding deionized water, WETAID™ NRW wetting agent (0.50 grams) and Fluorochemical Emulsion A in the amounts shown below in Table 1. Textile Substrate 1 (tan 100% cotton woven) and Textile Substrate 2 (olive 65/35 polyester/cotton woven) were dipped in the padding baths and then squeezed between rubber rollers to wring out the excess. The damp swatches were dried for ten minutes 100° C. and then cured for two minutes at 160° C. The calculated grams solids of FC Urethane Mixture A per 100 grams fabric (solids on fabric or SOF) are indicated below in Table 1.

TABLE 1 Textile Fluorochemical Treatment Water Emulsion A Bath (grams) (grams) SOF 1 237.99 11.51 0.88 2 231.89 17.61 1.35 3 225.80 23.70 1.82

The treated woven fabric substrates (Examples 1 to 6 in Table 2) were then tested for initial oil repellency, initial water repellency and initial stain release, and also tested after 20 and 30 launderings as described in the above test methods. The results are summarized in Table 2.

Textile Treatment Bath 4 was prepared by sequentially combining deionized water (141.89 grams), WETAID™ NRW wetting agent (0.30 grams), and Fluorochemical Emulsion A (7.81 grams). Textile Substrate 3 (white 100% cotton jersey knit) was dipped in the padding bath and then squeezed between rubber rollers to wring out the excess. The damp swatch was dried for ten minutes 100° C. and then cured for two minutes at 160° C. The calculated SOF was 1.33.

The treated knit fabric substrate (Example 7 in Table 2) was then tested for initial oil repellency, initial water repellency, and initial stain release, and also tested after 5 and 20 launderings as described in the above test methods. The results are summarized in Table 3.

TABLE 2 Initial After 20 Launderings After 30 Launderings Stain Stain Stain Stain Stain Stain Textile release release release release release release Treatment Textile (mineral (corn (mineral (corn (mineral (corn Example Bath Substrate OR WR oil) oil) OR WR oil) oil) OR WR oil) oil) 1 1 1 6 5 7 6.5 2 3 6.5 6.5 1 2 6.5 7 2 2 1 6 5 6.5 6.5 4 2 7.5 7 4 3 7 7 3 3 1 6 6 7.5 7 5 4 7.5 7 3 4 7 7 4 1 2 6 5 7.5 6.5 6 5 7 7 5 5 7 6.5 5 2 2 6 6 7.5 6.5 6 5 7 6.5 6 5 7 6.5 6 3 2 6 6 7 7 6 6 7.5 7 6 5 7 7

TABLE 3 Example 7 Initial After 5 Launderings After 20 Launderings Stain release Stain Release Stain Release OR WR (grape juice) OR WR (grape juice) OR WR (grape juice) 6 5 Not measured 6 5 4.8 3 4 4

EXAMPLES 8 to 23 AND COMPARATIVE EXAMPLE C1 to C3

Synthesis of FC Urethane Mixtures B to J

FC Urethane Mixtures B to J were prepared according to the procedure described above for FC Urethane Mixture A. The compositions are summarized in Table 4. Weight percent aliphatic fluorochemical urethane, weight percent blocked aromatic isocyanate extender, equivalent percent aliphatic isocyanate reactant, and weight percent fluorine versus FC Urethane Mixture solids, and weight percent fluorine versus aliphatic Fluorochemical Urethane solids are summarized in Table 5.

TABLE 4 FC Equiv % Equiv Urethane (HFPO)7.7- % Equiv % Equiv % Equiv % Mixture alc MEKO PPG-1025 MeFBSE MPEG-750 B 5.4 5.0 13.5 69.6 6.5 C 10.8 4.8 38.1 40.0 6.3 D 10.5 4.8 37.2 39.1 8.4 E 8.2 4.7 26.2 55.0 5.9 F 8.1 4.7 25.6 53.7 7.9 G 5.3 4.8 14.1 70.3 5.5 H 5.2 4.8 13.8 68.8 7.4 I 3.0 4.8 31.5 55.2 5.5 J 2.9 4.7 30.9 54.1 7.4

TABLE 5 Wt % Wt % Fluorine Wt % Fluorine in FC Wt % Aliphatic Blocked in Aliphatic Urethane Fluorochemical Aromatic Urethane Fluorochemical Mixture Urethane Isocyanate Mixture Urethane B 85 15 22.2 26.1 C 100 0 22.3 22.3 D 75 25 16.2 21.6 E 100 0 24.2 24.2 F 75 25 17.6 23.5 G 100 0 26.3 26.3 H 75 25 19.1 25.5 I 100 0 18.9 18.9 J 75 25 13.8 18.4

Synthesis of FC Urethane Mixtures K to U

FC Urethane Mixtures K to U were prepared according to the procedure described above for FC Urethane Mixture A except substituting different molecular weight polypropylene oxide-based diol materials for PPG-1025 (PPG-425, -725, and -2025), or excluding perfluorinated polyether (FC Urethane Mixture U). The compositions are summarized in Table 6. Weight percent aliphatic fluorochemical urethane, weight percent blocked aromatic isocyanate extender, equivalent percent aliphatic isocyanate reactant, and weight percent fluorine versus FC Urethane Mixture solids, and weight percent fluorine versus aliphatic Fluorochemical Urethane solids are summarized in Table 7.

TABLE 6 FC Equiv % Equiv Equiv Equiv % Urethane PPG (HFPO)7.7- % % Equiv % MPEG- Mixture MW alc MEKO PPG MeFBSE 750 K 426 3.4 4.8 38.2 49.0 4.6 L 426 3.4 4.7 37.5 48.1 6.3 M 726 2.7 4.8 37.4 50.0 5.1 N 726 2.6 4.8 36.7 49.0 6.9 O 726 2.6 4.7 35.9 48.0 8.8 P 726 5.6 4.8 19.6 62.8 7.2 Q 2000 3.6 4.8 19.0 66.4 6.2 R 2000 3.5 4.7 18.5 64.9 8.4 S 1976 4.5 4.8 38.1 45.1 7.5 T 1976 4.4 4.7 37.0 43.8 10.1 U 1000 0 4.8 32.4 55.6 7.2

TABLE 7 Wt % Wt % Wt % Fluorine in FC Wt % Aliphatic Blocked Fluorine in Aliphatic Urethane Fluorochemical Aromatic Urethane Fluorochemical Mixture Urethane Isocyanate Mixture Urethane K 100 0 21.1 21.1 L 75 25 15.4 20.5 M 100 0 18.3 18.3 N 75 25 13.3 17.7 O 60 40 10.3 17.2 P 75 25 18.6 24.8 Q 100 0 20.1 20.1 R 75 25 14.6 19.5 S 100 0 13.6 13.6 T 75 25 9.9 13.2 U 75 25 11.6 15.5

Synthesis of Comparative Urethane Mixtures C-A to C-D

FC Urethane Mixtures C-A to C-D were prepared according to the procedure described above for FC Urethane Mixture A, optionally substituting PPG-2025 molecular weight PPG for PPG-1025. The compositions are summarized in Table 8. Aliphatic fluorochemical urethane weight percent, blocked aromatic isocyanate extender weight percent, equivalent percent aliphatic isocyanate reactant, and weight percent fluorine versus FC Urethane Mixture solids, and weight percent fluorine versus aliphatic FC Fluorochemical Urethane solids are summarized in Table 9.

TABLE 8 FC Equiv % Equiv Equiv Equiv % Urethane PPG (HFPO)7.7- % % Equiv % MPEG- Mixture MW alc MEKO PPG MeFBSE 750 C-A 1000 22.3 4.8 0 64.9 8.0 C-B 1000 17.9 4.8 26.3 44.3 6.7 C—C 1000 17.5 4.8 25.6 43.1 9.0 C-D 1976 0 4.8 34.5 51.4 9.3

TABLE 9 Wt % Wt % Fluorine Wt % Fluorine in Comparative Wt % Aliphatic Blocked in Aliphatic Urethane Fluorochemical Aromatic Urethane Fluorochemical Mixture Urethane Isocyanate Mixture Urethane C-A 85 15 32.6 38.4 C-B 100 0 29.5 29.5 C-C 75 25 21.4 28.5 C-D 75 25 8.3 11.1

Preparation of Fluorochemical Emulsions B-U and Comparative Fluorochemical Emulsions C-A to C-D

Fluorochemical Emulsions B-U and Comparative Fluorochemical Emulsions C-A to C-D were prepared according to the Preparation of Fluorochemical Emulsion A procedure described above, except using Fluorochemical Emulsions B-U or Comparative Fluorochemical Emulsions C-A to C-D, respectively.

Textile Treatment

Textile Treatment Baths 5 to 20 and C-1 to C-3 were prepared and applied to Textile Substrate 3 (white 100% cotton jersey knit) as described for Textile Treatment Bath 4, except using mixtures of Fluorochemical Emulsion B to U or Comparative Fluorochemical Emulsions C-A to C-D, as indicated in Table 10. Applied SOF and weight percent fluorine versus urethane blend solids are also indicated in Table 10.

TABLE 10 Wt % blocked Wt % Textile Second aromatic fluorine in Treatment First FC FC isocyanate emulsion Bath Emulsion SOF Emulsion SOF in blend blend  5 B 1.96 None None 15 22.2  6 C 0.41 D 1.63 20 17.4  7 E 0.40 F 1.62 20 18.9  8 G 0.40 H 1.61 20 20.5  9 I 2.17 None None 0 18.9 10 I 1.76 J 0.44 5 17.9 11 I 1.34 J 0.89 10 16.9 12 I 0.91 J 1.36 15 15.8 13 I 0.46 J 1.84 20 14.8 14 K 0.85 L 1.28 15 17.7 15 M 0.92 N 1.37 15 15.3 16 O 2.46 None None 40 10.3 17 P 2.06 None None 25 18.6 18 Q 0.46 R 1.82 20 15.7 19 S 0.51 T 2.03 20 10.6 20 U 1.97 None none 25 11.6 C-1 C-A 0.86 None none 15 32.6 C-2 C-B 0.35 C-C 1.41 20 23.0 C-3 C-D 2.16 None none 25 8.3

The treated knit fabric substrates (Examples 8 to 23 and Comparative Examples C1 to C3 in Table 11) were then tested for initial oil repellency, initial water repellency, and initial stain release, and also tested after 5 and 20 launderings as described in the above test methods. The results are summarized in Table 11.

TABLE 11 After 5 After 20 Initial launderings launderings Stain Stain Stain Textile Release Release Release Treatment (grape (grape (grape Example Bath OR WR juice) OR WR juice) OR WR juice)  8 5 6 5 5 5 4 4.5 3 2 3.8  9 6 6 4 5 5 4 4.3 4 3 4 10 7 6 5 5 6 4 4.5 4 3 4.3 11 8 6 5 4.7 6 5 5 5 4 4 12 9 6 5 3.8 4 5 3.5 0 0 3.5 13 10 6 5 4 5 5 4 2 3 3.8 14 11 6 5 4.3 5 5 4.2 2 3 4 15 12 6 5 4.3 6 6 4.3 4 5 4.5 16 13 6 5 4.7 6 6 4.7 5 5 4.5 17 14 6 5 4.5 6 6 4.3 5 5 4.3 18 15 6 5 4.5 6 6 4.3 5 6 4.2 19 16 6 6 4.5 6 6 4.5 5 5 4.5 20 17 6 5 4.5 5 5 4.5 4 4 4.3 21 18 6 5 4.8 5 5 4.8 4 4 4.5 22 19 6 4 not 0 1 3.8 0 0 3.5 tested 23 20 6 7 not 5 6 4.7 4 4 4 tested C1 C1 6 4 4.2 2 0 2 1 0 2 C2 C2 6 4 4.2 5 3 4.3 4 2 4.5 C3 C3 6 7 not 0 0 3.2 0 0 3.7 tested

The above Examples and Comparative Examples demonstrate that: 1) fluorinated urethanes with low perfluorinated polyether levels can give excellent performance (compared to Textile Treatment Bath C1 to C3); 2) fluorochemical urethanes of this invention are advantageously combined with blocked aromatic isocyanate extender (compared to Textile Treatment Bath 9); 3) fluorinated urethanes with polyoxypropylene units can give excellent durability and stain release (compared to Textile Treatment Bath C1); and 4) fluorinated urethanes containing 15 to 26 weight percent fluorine can result in excellent performance.

Claims

1. A fluorochemical composition comprising a dispersion or a solution of a fluorinated compound, wherein said fluorinated compound comprises the reaction product of a combination of reactants comprising: wherein less than about 15% of the isocyanate groups are reacted with said fluorinated polyether, at least about 5% of the isocyanate groups are reacted with said polyoxyalkylene diol, at least about 35% of the isocyanate groups are reacted with said short chain perfluoroalkyl alcohol, and less than about 15% of the isocyanate groups are reacted with said isocyanate blocking group.

(i) one or more fluorinated polyethers according to the formula: RfQTk  (I) wherein Rf represents a monovalent perfluorinated polyether group having a number average molecular weight of at least 750 g/mol, Q represents a chemical bond or a divalent or trivalent organic linking group, T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2;
(ii) one or more polyoxyalkylene diols;
(iii) one or more short chain perfluoroalkyl alcohols;
(iv) one or more isocyanate component selected from a polyisocyanate compound that has at least 3 isocyanate groups or a mixture of polyisocyanate compounds wherein the average number of isocyanate groups per molecule is more than 2;
(v) optionally one or more isocyanate blocking group; and
(vi) optionally one or more co-reactants capable of reacting with an isocyanate group;

2. The fluorochemical composition of claim 1 wherein said composition is free of perfluoroaliphatic groups of more than 6 carbon atoms other than perfluorinated end groups of a perfluorinated polyether moiety and/or perfluorinated polyether groups having a number average molecular weight of less than 750 g/mol or wherein said composition contains said perfluoroaliphatic groups of more than 6 carbon atoms in an amount of not more than about 10% by weight based on the total weight of perfluoroaliphatic groups other than end groups of a perfluorinated polyether moieties and/or contains said perfluorinated polyether groups having a number average molecular weight of less than 750 g/mol in an amount of not more than about 10% by weight based on the total weight of perfluorinated polyether moieties in the fluorochemical composition.

3. The fluorochemical composition of claim 1 wherein Rf in formula (I) is a perfluoropolyether group derived from a polycondensation of hexafluoropropylene oxide.

4. The fluorochemical composition of claim 1 wherein Rf in formula (I) corresponds to the formula: wherein Rf1 represents a perfluorinated alkyl group, Rf2 represents a perfluorinated polyalkyleneoxy group consisting of perfluorinated alkyleneoxy groups having 2 or 3 carbon atoms or a mixture of such perfluorinated alkylene oxy groups, Rf3 represents a perfluorinated alkylene group, and q is 0 or 1.

Rf1ORf2(Rf3)q

5. The fluorochemical composition of claim 4 wherein Rf2 corresponds to the formula: wherein n is an integer of 3 to 25.

[CF(CF3)CF2O]n

6. The fluorochemical composition of claim 4 wherein Rf3 is CF(CF3), q is 1, and Rf2 corresponds to the formula: wherein n is an integer of 3 to 25.

[CF(CF3)CF2O]n

7. The fluorochemical composition of claim 1 wherein T is selected from the group consisting of hydroxy and amino groups.

8. The fluorochemical composition of claim 1 wherein said fluorinated polyether of formula (I) corresponds to the formula: wherein Rf1 represents a perfluorinated alkyl group, n is an integer of 3 to 25, A is a carbonyl group or CH2, Q1 is a chemical bond or an organic divalent or trivalent linking group, and T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2.

Rf1O[CF(CF3)CF2O]nCF(CF3)AQ1Tk

9. The fluorochemical composition of claim 1 wherein the fluorinated polyether compound corresponds to the formula: wherein Rf1 represents a perfluorinated alkyl group, n is an integer of 3 to 25, X represents O or NRb with Rb representing hydrogen or an alkyl group of 1 to 4 carbon atoms, Ra represents an alkylene group having 1 to 15 carbon atoms, and k is 1 or 2.

Rf1O [CF(CF3)CF2O]nCF(CF3)COXRa(OH)k

10. The fluorochemical composition of claim 1 wherein said organic linking group Q is selected from the group consisting of alkylene, oxyalkylene, aminoalkylene, amidoalkylene, carboxyalkylene.

11. The fluorochemical composition of claim 1 wherein said polyoxyalkylene diol is a polyoxypropylene diol having a number average molecular weight of from about 400 to about 2200.

12. The fluorochemical composition of claim 1 wherein said optional co-reactant has the formula: wherein Rf4 is a perfluoroaliphatic group having 3 to 6 carbon atoms; L is a non-fluorinated organic divalent or multivalent linking group; Y represents a functional group having a Zerewitinoff hydrogen; x is an integer of from 1 to 20; and y is 1 or 2.

(Rf4)xL(Y)y  (IV)

13. The fluorochemical composition of claim 12 wherein Rf4 is C4F9—, x is 1, and y is 1.

14. The fluorochemical composition of claim 1 wherein said isocyanate component comprises an aliphatic polyisocyanate.

15. The fluorochemical composition of claim 1 wherein said isocyanate blocking group is butanone oxime.

16. The fluorochecmial composition of claim 1 wherein said co-reactant comprises a monofunctional alcohol, a monofunctional amine, a polyol, or a polyamine.

17. The fluorochemical composition of claim 1 wherein said co-reactant comprises a polyoxyalkylene having 2 or 3 carbon atoms in the oxyalkylene groups and having 1 group capable or reacting with an isocyanate.

18. The fluorochemical composition of claim 1 wherein said non-fluorinated organic compound comprises one or more non-fluorinated organic compounds having only one functional group capable of reacting with an isocyanate group and one or more non-fluorinated organic compounds having two functional groups capable of reacting with an isocyanate group.

19. The fluorochemical composition of claim 1 wherein said fluorochemical composition is dispersed in water and wherein the number average particle size of the dispersed fluorinated polyether compound is from about 50 nm to about 400 nm.

20. The fluorochemical composition of claim 1 wherein said fluorinated polyether compound is dispersed in water and wherein the aqueous dispersion contains a surfactant.

21. The fluorochemical composition of claim 1 wherein the amount of fluorinated polyether compound in the composition is from about 0.1% by weight to about 10% by weight.

22. The fluorochemical composition of claim 1 further comprising a non-fluorinated organic compound, wherein the non-fluorinated organic compound is capable of improving relative to the fluorochemical composition without said non-fluorinated organic compound, the oil repellency or water repellency that can be achieved by the fluorochemical composition on a fibrous substrate or the durability of one or both of the repellency properties

23. The fluorochemical composition of claim 1 wherein said isocyanate blocking group is selected from the group consisting of arylalcohols; lactams; oximes, bisulfites; and triazoles.

24. A method of treatment of a fibrous substrate, comprising applying to the fibrous substrate a fluorochemical composition of claim 1.

25. The method of claim 24 wherein the amount of the fluorochemical composition applied is such that the amount of fluorinated polyether compound is from about 0.2% by weight to about 3% by weight relative to the weight of the fibrous substrate.

Patent History
Publication number: 20080116414
Type: Application
Filed: Nov 22, 2006
Publication Date: May 22, 2008
Applicant:
Inventor: Dean M. Moren (North St. Paul, MN)
Application Number: 11/562,458
Classifications
Current U.S. Class: Oil Or Water Repellent Or Soil Resistant Or Retardant (252/8.62)
International Classification: D06M 15/53 (20060101);