Polyisocyanate solutions useful for impregnating porous inorganic substrates

• US 5,254,660 A
• Filed: 11/02/1992
• Issued: 10/19/1993
• Est. Priority Date: 11/08/1991
• Status: Expired due to Fees

• Current Assignee: Bayer AG
• Original Assignee: Bayer AG
• Inventors: Muller, Hanns-Peter, Kirchmeyer, Stephan, Bohm, Stefan, Pedain, Josef, Kober, Hermann
• Primary Examiner(s): WELSH JR, MAURICE
• Application Number:
  US07/970,354
• Time in Patent Office: 351 Days
• Field of Search: 528/49, 528/70, 427/393.6, 427/425.5, 428/307.3, 568/842, 568/843
• US Class Current: 528/49
• CPC Class Codes: C04B 41/4846 Perfluoro-compounds
• CPC Class Codes: C07C 271/20 to carbon atoms of hydrocarbon radicals substituted by nitrogen atoms not being part of nitro or nitroso groups
• CPC Class Codes: C07C 271/24 with the nitrogen atom of at least one of the carbamate groups bound to a carbon atom of a ring other than a six-membered aromatic ring
• CPC Class Codes: C07C 31/40 perhalogenated
• CPC Class Codes: C07C 311/09 the carbon skeleton being further substituted by at least two halogen atoms
• CPC Class Codes: C07C 33/423 containing only double bonds as unsaturation
• CPC Class Codes: C08G 18/8054 with compounds of C08G18/38
• CPC Class Codes: C08G 18/8087 containing halogen atoms
• CPC Class Codes: E04B 1/66 Sealings damp-proof courses E04B1/644; fire-proof sealings E04B1/948; additions of anti-leak properties to plaster C04B; bituminous sealing masses C08L95/00; sealings for hydraulic engineering work in general E02B3/16; against ground humidity or ground water E02D31/02; coverings against rain or other precipitations of the atmosphere E04D; composition of material or manufacture of sealing foils, see the relevant classes for these foils
• CPC Class Codes: Y10T 428/249956 Void-containing component is inorganic

Abstract

Solutions of a) a fluorine-containing polyisocyanate in b) an isocyanate-inert solvent are used to impart water, oil and dirt resistance to porous inorganic substrates impregnated therewith. The fluorine-containing polyisocyanate is preferably selected from fluorine-containing polyisocyanates having a fluorine content in the form of perfluorinated alkyl groups of from about 15 to about 60% by weight and an isocyanate content of from about 0.5 to about 15% by weight. These isocyanates are obtained by reaction of (cyclo)aliphatic isocyanates with fluorine-containing mono- and polyhydric alcohols, and selected fluorine-containing alcohols suitable for the production of these polyisocyanates.

Claims

1. A fluorine-containing diisocyanate or polyisocyanate having a fluroine content determined as perfluorinated alkyl group content of from 15 to about 60% by weight, an isocyanate content of from about 0.5 to about 15% by weight and urethane groups which is the reaction product of

a) a diisocyanate or polyisocyanate having (cyclo)aliphatically bound isocyanate groups and a molecular weight of from about 168 to about 1,000 and

b) a less than equivalent amount of a fluroine-containing monohydric or dihydric alcohol selected from the group consisting of ##STR6## in which R^f represents a perfluoroalkyl group containing from 4 to 26 carbon atoms, and

R² represents a difunctional saturated aliphatic hydrocarbon radical containing from 2 to 4 carbon atoms,

R³ represents a C₁ -C₄ alkyl group,

R⁴ represents a trifunctional saturated aliphatic hydrocarbon radical containing from 3 to 4 carbon atoms, and

n represents 0, 1 or 2.

2. The diisocyanate or polyisocyanate of claim 1 in which any unreacted diisocyanate or polyisocyanate starting material is removed.

3. A process for treating a porous inorganic substrate to impart water, oil and dirt repellant protection to that substrate comprising impregnating the porous inorganic substrate with a solution of

a) a fluorine-containing diisocyanate or polyisocyanate having from about 15 to about 60% by weight perfluorinated alkyl groups present and an isocyanate content of from about 0.5 to about 15% by weight which is the reaction product ofa diisocyanate or polyisocyanate having a molecular weight in the range of from about 168 to about 1,000 and isocyanate groups which are (cyclo)aliphatically bound

(2) less than an equivalent quantity of a fluorine-containing alcohol selected from the group consisting of ##STR7## in which R^f represent a perfluoroalkyl group having from 4 to 16 carbon atoms

R² represent a difunctional saturated aliphatic hydrocarbon radical containing from 2 to 4 carbon atoms.

R³ represents a C₁ -C₄ alkyl group,

R⁴ represents a trifunctional saturated aliphatic hydrocarbon radical containing from 3 to 4 carbon atoms, and

n represents 0, 1 or 2

b) a solvent which does not react with the isocyanate groups.

4. The process of claim 3 in which the fluroine-containing diisocyanate or polyisocyanate contains urethane groups and is substantially free of urea groups.

5. The process of claim 3 in which any unreacted diisocyanate or polyisocyanate starting material is removed from the fluroine-containing diisocyanate or polyisocyanate.

6. An inorganic substrate coated with a solution of a fluorine-containing diisocyanate or polyisocyanate produced by the process of claim 3.

7. A fluroine-containing dihydric alcohol represented by the formula ##STR8## in which R^f represents a perfluoroalkyl group containing from 4 to 16 carbon atoms.