Fluorine-containing organic silicon compound, water repellent composition containing it, and surface-treated substrate and process for its production

A water repellent composition comprising a fluorine-containing organic silicon compound of the following formula (1):

• wherein Rf is a fluorine-containing C1-20 monovalent organic group, X1 is an alkylene group, n is an integer of from 0 to 100, R is a C1-5 monovalent hydrocarbon group, X is a hydrolyzable group, and p is 0, 1 or 2, further containing a fluorine-containing reactive silane compound (II) and/or a no fluorine-containing reactive silane compound (III), which is capable of forming a surface having an angle of contact with water of at least 100°.

A surface-treated substrate which is a substrate having at least three surface-treated layers, wherein the first layer as the outermost layer among the surface-treated layers, is a layer formed by a water repellent composition comprising a fluorine-containing organic silicon compound of the following formula (1):

• wherein Rf is a fluorine-containing C1-20 monovalent organic group, X1 is an alkylene group, n is an integer of from 0 to 100, R is a C1-5 monovalent hydrocarbon group, X is a hydrolyzable group, and p is 0, 1 or 2, the second layer in contact with the inside of the first layer, is a layer formed by a composition (II) containing a fluorine-containing reactive silane compound (II) and having a surface, of which an angle of contact with water is at least 100°;
• and the third layer in contact with the inside of the second layer, is a layer formed by a composition (III) containing a no fluorine-containing reactive silane compound (III).

A fluorine-containing organic silicon compound of the following formula

• wherein Rf is a fluorine-containing C1-20 monovalent organic group, X1 is an alkylene group, n is an integer of from 0 to 100, R is a C1-5 monovalent hydrocarbon group, X is a chlorine atom, NCO or an acyloxy group, and p is 0, 1 or 2.