TECHNICAL FIELD

The present invention relates to a laminate and its production method.

BACKGROUND ART

Fluorinated compounds, which have high lubricity, water/oil repellency, etc., are suitably used for a surface treatment agent. A surface treatment agent imparts water/oil repellency to the surface of a substrate, whereby stains on the surface of the substrate will be easily wiped off, and the stain removability will improve. Among the fluorinated compounds, fluorinated ether compounds having a poly(oxyperfluoroalkylene) chain in which an ether bond (—O—) is present in the middle of a perfluoroalkylene group are compounds excellent in flexibility and are particularly excellent in removability of oil stains, etc.

In recent years, application of the fluorinated ether compounds to various substrates has been attempted, and Patent Document 1 discloses a sapphire substrate having a surface layer formed of the fluorinated ether compound.

PRIOR ART DOCUMENTS

Patent Documents

Patent Document 1: JP-A-2016-060792

DISCLOSURE OF INVENTION

Technical Problem

In recent years, further improvement of the fingerprint removability on a surface layer obtained by using a surface treatment agent has been desired.

Heretofore, it has been considered to form a surface layer having a large water contact angle, such as a surface layer formed by using the fluorinated ether compound, so as to improve the fingerprint removability. However, it was found that the fingerprint removability of a surface layer formed on the surface of a substrate using the fluorinated ether compound as disclosed in Patent Document 1, should further be improved.

The present inventor has conducted extensive studies on such a problem and found that the fingerprint removability may sometimes be insufficient if the sliding angle for water (hereinafter sometimes referred to as “water sliding angle”) is large, even if the water contact angle of the surface layer is large.

Under these circumstances, the object of the present invention is to provide a laminate having a surface layer with a small water sliding angle, and its production method.

Solution to Problem

The present invention provides a laminate having the following constitutions [1] to [10], and a method for producing a laminate having the following constitutions [11] to [14].[1] A laminate comprising a substrate, an interlayer formed on the substrate, and a surface layer formed on the interlayer,

wherein the interlayer is a layer formed by using a triazine compound having at least one of a M-OH group (wherein M is a metal atom or a silicon atom) and a group capable of forming the M-OH group, at least one of an amino group and a mercapto group, and a triazine ring, and

the surface layer is a layer formed by using a fluorinated ether compound having a poly(oxyperfluoroalkylene) chain, and at least one of a hydrolyzable group bonded to a silicon atom and a hydroxy group bonded to a silicon atom.[2] The laminate according to [1], wherein the triazine compound has a group capable of forming the M-OH group, and the group capable of forming the M-OH group is a hydrolyzable silyl group.[3] The laminate according to [1] or [2], wherein the triazine compound has an amino group.[4] The laminate according to [3], wherein the triazine compound is a compound represented by the following formula TN-1 or TN-2:


wherein AN1is —N(RN1)—RN2—Si(RN3)Nn(ORN4)3-Nnor —N{RN2—Si(RN3)Nn(ORN4)3-Nn}2,

AN2is —N(RN5)—RN6(NH2)Nmor —N{RN6(NH2)Nm}2,

AN3is AN1, AN2or —N(RN7)—RN8,

AN4is a bivalent linking group,

RN1, RN5and RN7are each independently a hydrogen atom or a monovalent hydrocarbon group,

RN2is a bivalent linking group,

RN3and RN8are each independently a monovalent hydrocarbon group,

RN4is a hydrogen atom or a monovalent hydrocarbon group,

RN6is a (Nm+1) valent linking group,

Nn is an integer of from 0 to 2, and Nm is 1 or 2.[5] The laminate according to [1] or [2], wherein the triazine compound has a mercapto group.[6] The laminate according to [5], wherein the triazine compound is a compound represented by the following formula TS:


wherein ASis —N(RS4)—RS1—Si(RS2)Sn(ORS3)3-Snor —N{RS1—Si(RS2)Sn(ORS3)3-Sn}2,

RS1is a single bond or a bivalent linking group,

RS2is a monovalent hydrocarbon group,

RS3and RS4are each independently a hydrogen atom or a monovalent hydrocarbon group,

MS1is a hydrogen atom or an alkali metal atom, and

Sn is an integer of from 0 to 2.[7] The laminate according to any one of [1] to [6], wherein the fluorinated ether compound is represented by the following formula 1:
[A—O—Z1—(RfO)m—]jZ2[—SiRnL3-n]qFormula 1
wherein A is a perfluoroalkyl group or -Q[—SiRnL3-n]k,

Q is a (k+1) valent linking group,

k is an integer of from 1 to 10,

R is a monovalent hydrocarbon group,

L is a hydrolyzable group or a hydroxy group,

n is an integer of from 0 to 2,

Z1is a single bond, a C1-20oxyfluoroalkylene group having at least one hydrogen atom substituted by a fluorine atom, or a C1-20poly(oxyfluoroalkylene) group having at least one hydrogen atom substituted by a fluorine atom,

Rfis a perfluoroalkylene group,

m is an integer of from 2 to 200,

Z2is a (j+q) valent linking group, and

j and q are each independently an integer of at least 1.[8] The laminate according to [7], wherein A is a perfluoroalkyl group.[9] The laminate according to any one of [1] to [8], wherein the substrate has, on the outermost surface on the interlayer side, a sapphire layer, a metal layer, a metal oxide layer, a diamond-like carbon layer or a resin layer.[10] The laminate according to any one of [1] to [9], which is used for an article for an electronic device, an article for a transport device, an article for a precision device, an article for an optical device or an article for building.[11] A method for producing a laminate comprising a substrate, an interlayer formed on the substrate, and a surface layer formed on the interlayer,

which comprises forming on the substrate the interlayer by dry coating method or wet coating method using a triazine compound having at least one of a M-OH group (wherein M is a metal atom or a silicon atom) and a group capable of forming the M-OH group, at least one of an amino group and a mercapto group, and a triazine ring, and

forming on the interlayer the surface layer by dry coating method or wet coating method using a fluorinated ether compound having a poly(oxyperfluoroalkylene) chain, and at least one of a hydrolyzable group bonded to a silicon atom and a hydroxy group bonded to a silicon atom.[12] The method according to [11], wherein the dry coating method is vacuum deposition method.[13] The method according to [11], wherein the method of forming the interlayer by wet coating method is a method of forming the interlayer by using a composition containing the triazine compound and a liquid medium, applying the composition on the substrate, and removing the liquid medium from the formed coating film containing the liquid medium, and

the method of forming the surface layer by wet coating method is a method of forming the surface layer by using a composition containing the fluorinated ether compound and a liquid medium, applying the composition on the interlayer, and removing the liquid medium from the formed coating film containing the liquid medium.[14] The method according to any one of [11] to [13], wherein the triazine compound is a triazine compound having a hydrolyzable silyl group, an amino group or a mercapto group, and a triazine ring.

Advantageous Effects of Invention

According to the present invention, a laminate having a surface layer with a small water sliding angle can be provided.

