Aqueous polyurethane dispersions from solvent-free prepolymers using sulfonate diols

A solvent free process for the preparation of aqueous polyurethane dispersions which comprises

• a. the solvent free preparation of an NCO terminated prepolymer by the reaction of
• i. polyisocyanates,
• ii. diols which contain sulphonate groups and have melting or softening points below 120.degree. C of the general formula ##STR8## wherein A and B, which may be the same or different, each represents a divalent aliphatic hydrocarbon group containing from 1 to 6 carbon atoms;
• R represents hydrogen, an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms or a phenyl group;
• X.sup.(+) represents an alkali metal cation
• n and m, which may be the same or different, each represents an integer between from 0 to 30;
• o and p represent 0 or 1;
• and
• q represents an integer of from 0 to 2 and
• iii. optionally other compounds which are at least difunctional per the purpose of the isocyanate polyaddition reaction and contain hydrogen atoms which are reactive with isocyanate groups, sufficient amounts of ii being used to provide the final polymer with 0.1 to 6 wt. % of SO.sub.3 .sup.(-) groups and
• b. the dispersion in water of said prepolymer by either
• i. reacting the terminal isocyanate groups to form acylated amino end groups and then combining the prepolymer with water which may contain aqueous formaldehyde or formaldehyde donors, or
• ii. combining said prepolymer directly with water which may contain water soluble chain lengthening agents or polyamines under such conditions as to effect chain extension of the prepolymer.

The process of claim 3, wherein

• a. the optionally present reactive hydrogen bearing compounds are mainly diols with molecular weights between about 1000 and 6000 selected from the group consisting of hydroxypolyesters, hydroxypolyethers, hydroxypolythioethers, hydroxypolyacetals, hydroxypolycarbonates and hydroxypolyester amides,
• b. the prepolymer is prepared at temperatures between about 50 and 120.degree. C.,
• c. the sulphonate diol is selected from those of the general formula (1) of claim 10, wherein R is methyl or hydrogen, n and m are limited to 0 to 3 and
• i. A and B are methylene groups, o, p and q are all 1, or
• ii. A is a methylene group, B is an ethylene group, o and p are both 1, and q is 0, or
• iii. B is a methylene group, o is 0, p is 1 and q is 2;
• d. the water soluble chain lengthening agent is a diamine with a molecular weight above 31 in which the amino groups are exclusively primary or secondary and
• e. the final polymer has a sulphonate group content of about 0.6 to 3 wt. % based on the solid polymer.

A process for the solvent free preparation of aqueous polyurethane dispersions which comprises

• a. the solvent free preparation of an NCO terminated prepolymer by the reaction of
• i. polyisocyanates,
• ii. diols which contain sulphonate groups and have melting points below 120.degree. C of the formula ##STR9## wherein A and B which may be the same or different, each represents a divalent aliphatic hydrocarbon group containing from 1 to 6 carbon atoms;
• X.sup.(+) an ammonium group which may be substituted;
• o and p represent 0 or 1;
• and
• q represents an integer of from 0 to 2 and
• iii. optionally other compounds which are at least difunctional for the purpose of the isocyanate polyaddition reaction and contain hydrogen atoms which are reactive with isocyanate groups, sufficient amounts of ii being used to provide the final polymer with 0.1 to 6 wt. % of SO.sub.3.sup.(-) groups and
• b. the combination of said prepolymer with water containing polyamines having chemically fixed ionic groups under such conditions as to effect chain extention of the prepolymer.

A solvent free process for the preparation of aqueous polyurethane dispersions which comprises

• a. the solvent free preparation of an NCO terminated prepolymer by the reaction of
• i. polyisocyanates,
• ii. diols which contain sulphonate groups and have melting points below 120.degree. C of the formula ##STR10## wherein R represents hydrogen or a methyl group;
• n and m which may be the same or different, each represents an integer of from 0 to 3;
• and
• X.sup.(+) represents an alkali metal cation
• iii. optionally other compounds which are at least difunctional for the purpose of the isocyanate polyaddition reaction and contain hydrogen atoms which are reactive with isocyanate groups, sufficient amounts of ii being used to provide the final polymer with 0.1 to 6 wt. % of SO.sub.3.sup.(+) groups, and
• b. the dispersion in water of said prepolymer by either
• i. reacting the terminal isocyanate groups to form acylated amino end groups and then combining the prepolymer with water which may contain aqueous formaldehyde or formaldehyde donors, or
• ii. combining said prepolymer directly with water which may contain water soluble chain lengthening agents or polyamines under such conditions as to effect chain extension of the prepolymer.

A solvent free process for the preparation of aqueous polyurethane dispersions which comprises

• a. the solvent free preparation of an NCO terminated prepolymer by the reaction of
• i. polyisocyanates,
• ii. diols which contain sulphonate groups and have softening or melting points below 120.degree. C of the formula ##STR11## wherein R represents hydrogen or a methyl group;
• n and m which may be the same or different, each represents an integer of from 0 to 3;
• and
• X.sup.(+) represents an alkali metal cation
• iii. optionally other compounds which are at least difunctional for the purpose of isocyanate polyaddition reaction and contain hydrogen atoms which are reactive with isocyanate groups,
• sufficient amounts of ii being used to provide the final polymer with 0.1 to 6 wt. % of SO.sub.3 .sup.(-) groups, and
• b. the dispersion in water of said prepolymer by either
• i. reacting the terminal isocyanate groups to form acylated amino end groups and then combining the prepolymer with water which may contain aqueous formaldehyde or formaldehyde donors, or
• ii. combining said prepolymer directly with water which may contain water soluble chain lengthening agents or polyamines under such conditions as to effect the chain extension of the prepolymer.

A solvent free process for the preparation of aqueous polyurethane dispersions which comprises

• a. the solvent free preparation of a NCO terminated prepolymer by the reaction of:
• i. polyisocyanates,
• ii. diols which contain sulphonate groups and have melting points below 120.degree. C of the general formula ##STR12## wherein A and B which may be the same or different, each represents a divalent aliphatic hydrocarbon group containing from 1 to 6 carbon atoms;
• R represents hydrogen, an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms or a phenyl group,
• X.sup.(+) an ammonium group which may be substituted;
• n and m which may be the same or different, each represents an integer of from 0 to 30 and their sum is greater than 0,
• o and p represent 0 or 1;
• and
• q represents an integer of from 0 to 2, and
• iii. optionally other compounds which are at least difunctional for the purpose of the isocyanate polyaddition reaction and contain hydrogen atoms which are reactive with isocyanate groups,
• sufficient amounts of ii being used to provide the final polymer with 0.1 to 6 wt. % of SO.sub.3.sup.(-) groups, and
• b. combining said prepolymer directly with water and polyamines having chemically fixed ionic groups under such conditions as to effect chain extension of the prepolymer.