A fluoro(poly)ether group-containing silane compound represented by any of the formulae (A1), (A2), (B1), (B2), (C1), or (C2). In the formulae, PFPE is each independently at each occurrence a group represented by the formula: —(OC.sub.3F.sub.6).sub.d—, wherein the repeating unit OC.sub.3F.sub.6 of the formula includes a branched structure, and d is an integer of 2 or more and 200 or less. The symbols are as defined in the description.

To provide a fluorinated ether compound, a fluorinated ether composition and a coating liquid capable of forming a surface layer excellent in initial water/oil repellency, fingerprint stain removability, abrasion resistance, light resistance and chemical resistance, an article having a surface layer, and a method for producing it. A fluorinated ether compound represented by A-O—(R.sup.f1O).sub.m—R.sup.f2-Z.sup.1-Q.sup.1 (R.sup.1).sub.b, wherein A is a C.sub.1-20 perfluoroalkyl group, R.sup.f1 is a linear fluoroalkylene group, m is an integer of from 2 to 500, R.sup.f2 is a linear fluoroalkylene group, Z.sup.1 is a single bond, —(CR.sup.2R.sup.3).sub.c— (wherein R.sup.2 and R.sup.3 are a hydrogen atom, a C.sub.1-6 monovalent organic group or the like, and c is an integer of from 1 to 10), a specific bond or a bivalent organic group having a specific bond, Q.sup.1 is a group having a (b+1) valent ring, R.sup.1 is a monovalent organic group having at least one hydrolyzable silyl group, and b is an integer of at least 2.

To provide a fluorinated ether compound, a fluorinated ether composition and a coating liquid capable of forming a surface layer excellent in initial water/oil repellency, fingerprint stain removability, abrasion resistance, light resistance and chemical resistance, an article having a surface layer, and a method for producing it. A fluorinated ether compound represented by A-O—(R.sup.f1O).sub.m—R.sup.f2-Z.sup.1-Q.sup.1 (R.sup.1).sub.b, wherein A is a C.sub.1-20 perfluoroalkyl group, R.sup.f1 is a linear fluoroalkylene group, m is an integer of from 2 to 500, R.sup.f2 is a linear fluoroalkylene group, Z.sup.1 is a single bond, —(CR.sup.2R.sup.3).sub.c— (wherein R.sup.2 and R.sup.3 are a hydrogen atom, a C.sub.1-6 monovalent organic group or the like, and c is an integer of from 1 to 10), a specific bond or a bivalent organic group having a specific bond, Q.sup.1 is a group having a (b+1) valent ring, R.sup.1 is a monovalent organic group having at least one hydrolyzable silyl group, and b is an integer of at least 2.

Provided is a surface protectant that suppresses corrosion of a semiconductor wafer surface by a basic compound, and reduces defects in the semiconductor wafer. The semiconductor wafer surface protectant of the present invention includes a compound represented by Formula (1) below;
R.sup.1O—(C.sub.3H.sub.6O.sub.2).sub.n—H  (1) where R.sup.1 denotes a hydrogen atom, a hydrocarbon group that has from 1 to 24 carbon atoms and may have a hydroxyl group, or a group represented by R.sup.2CO, where the R.sup.2 denotes a hydrocarbon group having from 1 to 24 carbon atoms; and n indicates an average degree of polymerization of a glycerin unit shown in the parentheses, and is from 2 to 60.

A surface coating material includes a plurality of fluorine-containing silicon compounds and an additive. The fluorine-containing silicon compounds include a fluorine-containing (poly)ether moiety, a hydrolytic silane moiety, and a linking group between the fluorine-containing (poly)ether moiety and the hydrolytic silane moiety. The linking group is configured to form a non-covalence interaction between adjacent molecules.

A surface coating material includes a plurality of fluorine-containing silicon compounds and an additive. The fluorine-containing silicon compounds include a fluorine-containing (poly)ether moiety, a hydrolytic silane moiety, and a linking group between the fluorine-containing (poly)ether moiety and the hydrolytic silane moiety. The linking group is configured to form a non-covalence interaction between adjacent molecules.

A polyether-modified siloxane represented by an average composition formula (1): (R.sub.3SiO.sub.1/2).sub.a(R.sub.2R′SiO.sub.1/2).sub.a′(R.sub.2SiO.sub.2/2).sub.b(RR′SiO.sub.2/2).sub.b′(RSiO.sub.3/2).sub.c(SiO.sub.4/2).sub.d. In the formula (1), “R”s each represent a hydrogen atom, a hydroxy group, a monovalent hydrocarbon group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, “R” 's each represent an organic group selected from groups represented by —C.sub.qH.sub.2q—O—(C.sub.2H.sub.4O).sub.e(C.sub.3H.sub.6O).sub.f—R.sup.1, R.sup.1s each represent a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or an organic group represented by R.sup.6—(CO)—, and R.sup.6 represents a hydrocarbon group having 1 to 30 carbon atoms. This can provide a novel polyether-modified siloxane that has little environmental impact and that provides excellent antifouling performance.

A fluorinated ether compound represented by A-O—(R.sup.f1O).sub.m—R.sup.f2—[C(O)N(R.sup.1)].sub.p-Q.sup.1-C(R.sup.2)[-Q.sup.2-SiR.sup.3.sub.nL.sub.3-n].sub.2, wherein A is a C.sub.1-20 perfluoroalkyl group, R.sup.f1 is a linear fluoroalkylene group, m is an integer of from 2 to 500, R.sup.f2 is a linear fluoroalkylene group, R.sup.1 is a hydrogen atom or an alkyl group, p is 0 or 1, Q.sup.1 is a single bond or an alkylene group, R.sup.2 is a hydrogen atom, a monovalent hydrocarbon group or the like, Q.sup.2 is an alkylene group, R.sup.3 is a hydrogen atom or a monovalent hydrocarbon group, L is a hydrolyzable group, and n is an integer of from 0 to 2 is provided. A fluorinated ether composition and a coating liquid capable of forming a surface layer excellent in initial water/oil repellency, fingerprint stain removability, abrasion resistance, light resistance and chemical resistance, an article having a surface layer, and a method for producing it are also provided.

A fluorinated ether compound represented by A-O—(R.sup.f1O).sub.m—R.sup.f2—[C(O)N(R.sup.1)].sub.p-Q.sup.1-C(R.sup.2)[-Q.sup.2-SiR.sup.3.sub.nL.sub.3-n].sub.2, wherein A is a C.sub.1-20 perfluoroalkyl group, R.sup.f1 is a linear fluoroalkylene group, m is an integer of from 2 to 500, R.sup.f2 is a linear fluoroalkylene group, R.sup.1 is a hydrogen atom or an alkyl group, p is 0 or 1, Q.sup.1 is a single bond or an alkylene group, R.sup.2 is a hydrogen atom, a monovalent hydrocarbon group or the like, Q.sup.2 is an alkylene group, R.sup.3 is a hydrogen atom or a monovalent hydrocarbon group, L is a hydrolyzable group, and n is an integer of from 0 to 2 is provided. A fluorinated ether composition and a coating liquid capable of forming a surface layer excellent in initial water/oil repellency, fingerprint stain removability, abrasion resistance, light resistance and chemical resistance, an article having a surface layer, and a method for producing it are also provided.

A surface coating material includes a first material and a second material having a different structure. The first material includes a linking group represented by *—(CF.sub.2).sub.nO—* between two terminal ends, where one terminal end is a trifluoroalkoxy group and another terminal end is a silane group. The second material includes an oxyalkylene group or a *—NH—* linking group between two terminal ends, where one terminal end is an alkoxy group or an amino group, and another terminal end is a silane group. The first material is included in the surface coating material in an amount of less than or equal to about 5 mol % relative to a total amount (100 mol %) of the first material and the second material in the surface coating material.