Patent GB-1046141-A (GB)
Title: Method of repelling water from a transparent member
Inventor: GUNNAR KEITH
IPC: C09K3/18
Filed: 1965-01-12
Abstract: Visibility through a transparent member, e.g. a glass windscreen, is improved or maintained by application thereto as a water-repellent coating a solution of an amine of the formula <FORM:1046141/C4-C5/1> in which R6 is an aliphatic radical containing from 8 to 22 carbon atoms, x and y are integers whose sum is from 0 to 50, or a salt thereof with an acid of the formula HZ where Z is an anion. The amine or amine salt may constitute up to 20% by weight of the solution. The solution may also contain a compound of the formula <FORM:1046141/C4-C5/2> in which R1 is an aliphatic radical containing from 12 to 22 carbon atoms, R2 is a methyl radical or an aliphatic radical containing from 12 to 22 carbon atoms, R3 is a methyl or <FORM:1046141/C4-C5/3> radical, R4 is a methyl or <FORM:1046141/C4-C5/4> radical, m and n are integers whose sum is from 2 to 15, R5 is H or a methyl radical and X is an anion.  The solution may contain a straightchain aliphatic alcohol containing from 12 to 16 carbon atoms.  The total solute content of the solution may not exceed 30% by weight of the solution.  The coating may be a unimolecular layer of the water-repellent substance or substances. Examples of amines, amine salts, quaternary ammonium compounds, aliphatic alcohols and solvents therefore are given.ALSO:A method of producing an optically clear water repellent coating on a transparent member comprises applying a solution of an amine of the formula <FORM:1046141/B1-B2/1> in which R6 is an aliplastic radical containing from 8 to 22 carbon atoms, x and y are integers whose sum is from 0 to 50, or a salt thereof with an acid of the formula HZ where Z is an anion to the surface donor sites, defined as being a site on a surface available for acceptance of a water-repellent substance such as an anionic charge site, a hydrogen bond site or an acidic site, and permitting the solvent to be removed from the solution.  The amine or amine salt may constitute up to 20% by weight of the solution. The solution may also contain a compound of the formula <FORM:1046141/B1-B2/2> in which R1 is an aliphetic radical containing from 12 to 22 carbon atoms, R2 is a methyl radical or an aliphatic radical containing from 12 to 22 carbon atoms, R3 is a methyl or <FORM:1046141/B1-B2/3> radical, R4 is a methyl or <FORM:1046141/B1-B2/4> radical, m and n are integers whose sum is from 2 to 15, R5 is H or a methyl radical and X is an anion.  The solution may also contain a straight chain aliphatic alcohol containing from 12 to 16 carbon atoms.  The total solute contents of the solution may not exceed 30% by weight of the solution.  The solution may be a solution in ethylene glycol other solvents also being referred to. The transparent member may be glass.  The water-repellent coating may be a uni-molecular layer of the water-repellent substance or substances.  A system for rendering the surface of a transparent member on a vehicle water repellent comprises a container mounted on the vehicle holding a solution of an amine of the formula <FORM:1046141/B1-B2/5> in which R6, x and y are as defined above, as a solution of a salt thereof with an acid of the formula HZ, where Z is an anion, and means associated with the container for discharging the solution from the container on to the surface of the transparent member.