Water/oil repellent layer-provided article and method for producing it

Abstract

A water/oil repellent layer-provided article, containing a substrate, a water/oil repellent layer containing a hydrolyzed condensate of a fluorinated compound having a hydrolyzable silyl group, and a silicon oxide layer containing alkali metal atoms, present between the substrate and the water/oil repellent layer, where in the silicon oxide layer, the average concentration of the alkali metal atoms in a region with a depth from the surface in contact with the water/oil repellent layer of at least 0.1 nm and at most 0.3 nm, is at least 2.0×1019 atoms/cm3.

1 . An article, comprising:
 a substrate,   a water/oil repellent layer comprising a hydrolyzed condensate of a fluorinated compound having a hydrolyzed silyl group, and   a silicon oxide layer comprising alkali metal atoms, present between the substrate and the water/oil repellent layer,   wherein the fluorinated compound is a compound having a fluoroalkyl group and the hydrolyzed silyl group, a compound having a group having an etheric oxygen atom between carbon atoms of a fluoroalkyl group and the hydrolyzed silyl group or a compound having a fluoroalkyl group, the hydrolyzed silyl group and a poly(oxyfluoroalkylene) chain,   
       wherein the silicon oxide layer has a surface in contact with the water/oil repellent layer, and
 in the silicon oxide layer, an average concentration of the alkali metal atoms in a region with a depth from the surface in contact with the water/oil repellent layer of from 0.1 to 0.3 nm, is at least 2.0×10 19  atoms/cm 3 . 
 
     
     
         2 . The article according to  claim 1 , wherein the fluorinated compound having the hydrolyzed silyl group has at least 2 hydrolyzed silyl groups. 
     
     
         3 . The article according to  claim 1 , wherein the fluorinated compound having the hydrolyzed silyl group is a compound having a fluoroalkyl group, the hydrolyzed silyl group and a poly(oxyfluoroalkylene) chain, and the poly(oxyfluoroalkylene) chain is composed of C 1-10  oxyfluoroalkylene groups. 
     
     
         4 . The article according to  claim 3 , wherein the poly(oxyfluoroalkylene) chain is composed of C 1-10  oxyperfluoroalkylene groups. 
     
     
         5 . The article according to  claim 1 , wherein the fluorinated compound having the hydrolyzed silyl group is a fluorinated ether compound represented by the following formula (X):
   [A 1 -O—(R f1 O) m1 ] a -Q-[SiR 13   n1 X 1   3-n1 ] b    (X)
   
       wherein A 1  is a C 1-20  perfluoroalkyl group, R f1  is a C 1-10  fluoroalkylene group, m1 is an integer of from 2 to 210, (R f1 O) m1  may be one composed of two or more types of R f1 O differing in the number of carbon atoms, “a” and “b” are each independently an integer of at least 1, Q is a (a+b) valent linking group, R 13  is a hydrogen atom or a monovalent hydrocarbon group, X 1  is a hydrolyzable group, n1 is an integer of from 0 to 2, and each of the [SiR 13   n1 X 1   3-n1 ] may be the same or different. 
     
     
         6 . The article according to  claim 1 , wherein the average concentration of the alkali metal atoms is from 2.0×10 19  atoms/cm 3  to 4.0×10 22  atoms/cm 3 . 
     
     
         7 . The article according to  claim 1 , wherein at least part of the alkali metal atoms are sodium atoms. 
     
     
         8 . The article according to  claim 1 , wherein silicon oxide in the silicon oxide layer comprises a condensate of silicic acid or a hydrolyzed condensate of an alkoxysilane. 
     
     
         9 . The article according to  claim 1 , wherein silicon oxide in the silicon oxide layer comprises a deposit of silicon oxide comprising the alkali metal atoms. 
     
     
         10 . A method for producing an article, comprising:
 forming a silicon oxide layer comprising alkali metal atoms on a surface of a substrate using a silicon oxide-forming material comprising a silicon oxide precursor and an alkali metal source, and   forming, on a surface of the silicon oxide layer, a water/oil repellent layer comprising a hydrolyzed condensate of a fluorinated compound having a hydrolyzed silyl group,   wherein the fluorinated compound is a compound having a fluoroalkyl group and the hydrolyzed silyl group, a compound having a group having an etheric oxygen atom between carbon atoms of a fluoroalkyl group and the hydrolyzed silyl group or a fluorinated compound having a fluoroalkyl group, the hydrolyzed silyl group and a poly(oxyfluoroalkylene) chain, and   the silicon oxide layer is a silicon oxide layer in which an average concentration of the alkali metal atoms in a region with a depth from the surface of the silicon oxide layer in contact with the water/oil repellent layer of from 0.1 to 0.3 nm is at least 2.0×10 19  atoms/cm 3 .   
     
     
         11 . The production method according to  claim 10 , wherein the fluorinated compound having the hydrolyzed silyl group has at least 2 hydrolyzed silyl groups. 
     
     
         12 . The production method according to  claim 10 , wherein the fluorinated compound having the hydrolyzed silyl group is a compound having a fluoroalkyl group, the hydrolyzed silyl group and a poly(oxyfluoroalkylene) chain, and the poly(oxyfluoroalkylene) chain is composed of C 1-10  oxyfluoroalkylene groups. 
     
     
         13 . The production method according to  claim 12 , wherein the poly(oxyfluoroalkylene) chain is composed of C 1-10  oxyperfluoroalkylene groups. 
     
     
         14 . The production method according to  claim 10 , wherein the fluorinated compound having the hydrolyzed silyl group is a fluorinated ether compound represented by the following formula (X):
   [A 1 -O—(R f1 O) m1 ] a -Q-[SiR 13   n1 X 1   3-n1 ] b    (X)
   
       wherein A 1  is a C 1-20  perfluoroalkyl group, R f1  is a C 1-10  fluoroalkylene group, m1 is an integer of from 2 to 210, (R f1 O) m1  may be one composed of two or more types of R f1 O differing in the number of carbon atoms, “a” and “b” are each independently an integer of at least 1, Q is a (a+b) valent linking group, R 13  is a hydrogen atom or a monovalent hydrocarbon group, X 1  is a hydrolyzable group, n1 is an integer of from 0 to 2, and each of the [SiR 13   n1 X 1   3-n1 ] may be the same or different. 
     
     
         15 . The production method according to  claim 10 , wherein the silicon oxide layer is formed on the substrate surface using a coating fluid comprising at least one silicon oxide precursor selected from the group consisting of silicic acid, a partial condensate of silicic acid, a tetraalkoxysilane or its partial condensate, an alkali metal source and a solvent. 
     
     
         16 . A method for producing an article, comprising:
 forming a silicon oxide layer comprising alkali metal atoms on a surface of a substrate using silicon oxide comprising the alkali metal atoms, and   forming, on a surface of the silicon oxide layer, a water/oil repellent layer comprising a hydrolyzed condensate of a fluorinated compound having a hydrolyzed silyl group,   wherein the fluorinated compound is a compound having a fluoroalkyl group and the hydrolyzed silyl group, a compound having a group having an etheric oxygen atom between carbon atoms of a fluoroalkyl group and the hydrolyzed silyl group or a compound having a fluoroalkyl group, the hydrolyzed silyl group and a poly(oxyfluoroalkylene) chain, and   the silicon oxide layer is a silicon oxide layer in which an average concentration of the alkali metal atoms in a region with a depth from the surface of the silicon oxide layer in contact with the water/oil repellent layer of from 0.1 to 0.3 nm is at least 2.0×10 19  atoms/cm 3 .   
     
     
         17 . The production method according to  claim 16 , wherein the fluorinated compound having the hydrolyzed silyl group has at least 2 hydrolyzable silyl groups. 
     
     
         18 . The production method according to  claim 16 , wherein the fluorinated compound having the hydrolyzed silyl group is a fluorinated compound having a fluoroalkyl group, the hydrolyzed silyl group and a poly(oxyfluoroalkylene) chain, and the poly(oxyfluoroalkylene) chain is composed of C 1-10  oxyfluoroalkylene groups. 
     
     
         19 . The production method according to  claim 18 , wherein the poly(oxyfluoroalkylene) chain is composed of C 1-10  oxyperfluoroalkylene groups. 
     
     
         20 . The production method according to  claim 16 , wherein the fluorinated compound having the hydrolyzed silyl group is a fluorinated ether compound represented by the following formula (X):
   [A 1 -O—(R f1 O) m1 ] a -Q-[SiR 13   n1 X 1   3-n1 ] b    (X)
   
       wherein A 1  is a C 1-20  perfluoroalkyl group, R f1  is a C 1-10  fluoroalkylene group, m1 is an integer of from 2 to 210, (R f1 O) mi  may be one composed of two or more types of R f1 O differing in the number of carbon atoms, “a” and “b” are each independently an integer of at least 1, Q is a (a+b) valent linking group, R 13  is a hydrogen atom or a monovalent hydrocarbon group, X 1  is a hydrolyzable group, n1 is an integer of from 0 to 2, and each of the [SiR 13   n1 X 1   3-n1 ] may be the same or different. 
     
     
         21 . The production method according to  claim 16 , wherein the content of the alkali metal atoms in the silicon oxide comprising the alkali metal atoms is at least 200 ppm to a total number of silicon atoms in the silicon oxide layer. 
     
     
         22 . The production method according to  claim 16 , wherein the method of forming the silicon oxide layer is a deposition method. 
     
     
         23 . The production method according to  claim 10 , wherein the average concentration of the alkali metal atoms in the region is from 2.0×10 19  atoms/cm 3  to 4.0×10 22  atoms/cm 3 . 
     
     
         24 . The production method according to  claim 10 , wherein at least part of the alkali metal atoms are sodium atoms. 
     
     
         25 . The production method according to  claim 10 , wherein the surface of the substrate is treated by corona discharge treatment, plasma treatment or plasma graft polymerization treatment, and then on the treated substrate surface, the silicon oxide layer is formed.