WO2013151003A1 - Durable water- and moisture-proof coating composition - Google Patents

Abstract

The present invention provides a durable water- and moisture-proof coating composition, comprising (I) a polymer obtained by polymerizing a fluoroalkyl-group-containing acrylate having a substitution group at the α position and having a fluoroalkyl group ester bonded directly or through a bivalent organic group to a carboxyl group, wherein the polymer is either (1) obtained by radical polymerization of a monomer component containing a radical polymeric monomer having an alkoxysilyl group and an acrylic acid ester and having a fluoroalkyl group or (2) is a fluoropolymer comprising a polymer obtained by radical polymerization of a fluoroalkyl-group-containing acrylate in the presence of an alkoxysilyl-group-containing mercaptan, and (II) a fluorine-based solvent. The present invention provides a coating composition that can form a film with excellent durability and favorable water- and moisture-proof performance with regards to a variety of substrates, and electronic components in particular.

Description

Durable waterproof and moisture-proof coating composition

The present invention relates to a coating composition capable of forming a waterproof and moisture-proof film having excellent wear resistance on various substrates, and an electronic component that requires chemical erosion resistance. It is related with the coating composition which can form the waterproof and moisture-proof film | membrane excellent in abrasion resistance, without inhibiting this.

In recent years, with the proliferation of multifunctional mobile terminals typified by smartphones and tablets, methods for imparting water resistance and moisture resistance have become issues. Since these devices have a large number of electronic components arranged in a small casing, there are almost no extra gaps, and it is difficult to pack them with conventionally used silicone rubber. In addition, a non-fluorine-based waterproof / moisture-proof coating agent represented by HumiSeal (manufactured by Chase Corp., USA) cannot exhibit sufficient waterproof / moisture-proof performance unless it is formed with a very thick film thickness of 100 μm or more.

Fluoro-based waterproof / moisture-proof coating agent in which fluoroalkyl (meth) acrylate homopolymer is dissolved in fluorinated solvent can provide sufficient waterproof / moisture-proof performance with a film thickness of 1 μm or less. Attention has been paid. However, conventional fluorine-based waterproof / moisture-proof coating agents do not have sufficient wear resistance, and workers and assembly equipment inadvertently touch the waterproof / moisture-proof processed parts on the production line, or consumers are waterproof / moisture-proof charged. By repeatedly using connectors and earphone jacks, there was a problem that the fluorine-based polymer peeled off and the initial waterproof / moisture-proof performance could not be maintained.

In addition, a solution in which a polyfluoroalkyl group-containing polymer is dissolved in a nonflammable low-boiling solvent is applied to the surface of the electronic component, and the solvent is dried to form a coating film made of the polyfluoroalkyl group-containing polymer. A method is known (see Patent Document 1 below). However, the treatment liquid used in this method cannot be used at present because it uses a specific chlorofluorocarbon that is prohibited from being used as a solvent.

The following Patent Document 2 discloses a fluorine-based surface modification comprising a copolymer of a (meth) acrylate monomer containing a C6 perfluoroalkyl group and a functional group-containing monomer, and a fluorine-based solvent capable of dissolving the copolymer. A quality composition is disclosed. If a functional group of this copolymer is selected so that it can chemically react with the substrate or has a good affinity, it is expected that the abrasion resistance of the coating will be improved. However, in the above method, there is a problem that the solubility in a fluorine-based solvent is lowered only by copolymerizing a perfluoroalkyl group-containing (meth) acrylate monomer with a functional group-containing monomer of only several weight%. For this reason, a sufficient amount of functional groups cannot be introduced, and the wear resistance of the coating film cannot be sufficiently improved.

JP-A 61-189893 JP 2009-57530 A

The present invention has been made in view of the current state of the prior art described above, and its main purpose is to form a film having excellent waterproof and moisture-proof performance with excellent wear resistance on various substrates. It is possible to provide a coating composition that can be formed, and to form a waterproof and moisture-proof coating with excellent wear resistance without impairing the function of electronic components that require chemical erosion resistance. Coating composition is provided.

The present inventor has intensively studied to achieve the above-mentioned purpose. As a result, an acrylic ester having a fluoroalkyl group and having a substituent at the α-position was used as a monomer, and the monomer containing the fluoroalkyl group-containing acrylic ester and an alkoxysilyl group-containing radical polymerizable monomer was used. A polymer obtained by radical polymerization of a monomer component or a polymer obtained by radical polymerization of the fluoroalkyl group-containing acrylic ester in the presence of an alkoxysilyl group-containing mercaptan is a fluorine-based solvent, particularly a chemical compound. It has been found that the solubility in hydrofluoroethers is low with low erosion and less adverse effects on the environment. And the composition which melt | dissolved this fluoropolymer in the fluorine-type solvent can form the waterproof and moisture-proof film excellent in abrasion resistance, without having a bad influence with respect to various materials containing an electronic component. The headline and here came to complete the present invention.

That is, the present invention provides the following durable waterproof / moisture-proof coating composition and a method for forming a durable waterproof / moisture-proof coating.
Item 1.
(I) radical polymerization of a fluoroalkyl group-containing acrylate ester having a fluoroalkyl group ester-bonded directly or via a divalent organic group to a carboxyl group and having a substituent at the α-position A polymer obtained, which is a fluoropolymer comprising the polymer shown in the following (1) or (2): (1) a monomer containing the fluoroalkyl group-containing acrylic acid ester and an alkoxysilyl group-containing radical polymerizable monomer A polymer obtained by radical polymerization of components,
(2) a polymer obtained by radical polymerization of the fluoroalkyl group-containing acrylic acid ester in the presence of an alkoxysilyl group-containing mercaptan;
And (II) a durable waterproof / moisture-proof coating composition characterized by containing a fluorine-based solvent.
Item 2. The fluoroalkyl group-containing acrylic ester is represented by the following general formula (1):

(In the formula, X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom or a chlorine atom) A cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a straight chain having 1 to 20 carbon atoms Or Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom, or an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom An aliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, an araliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, —CH ₂ CH ₂ N ( R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl group having 1 to 4 carbon atoms) A —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1 to 10); 2. The durable waterproof / moisture-proof coating composition according to Item 1, wherein Rf is a straight-chain or branched fluoroalkyl group having 1 to 20 carbon atoms.
Item 3. The fluoroalkyl group-containing acrylic ester is an α-position in which Rf is a linear or branched fluoroalkyl group having 4 to 6 carbon atoms and X is an atom or group other than hydrogen in the general formula (1) Item 3. The durable waterproof / moisture-proof coating composition according to Item 2, wherein is a substituted carboxylic acid ester.
Item 4. The fluorine-containing polymer is a polymer obtained by radical polymerization of a monomer component containing a fluoroalkyl group-containing acrylic acid ester and an alkoxysilyl group-containing radical polymerizable monomer, Item 4. The durable waterproof / moisture-proof coating composition according to any one of Items 1 to 3, which is a copolymer obtained by using a softening point monomer.
Item 5. The fluorine-containing polymer is a polymer obtained by radical polymerization of the fluoroalkyl group-containing acrylic ester in the presence of an alkoxysilyl group-containing mercaptan, and further, a monomer component having a high softening point monomer 4. The durable waterproof / moisture-proof coating composition according to any one of Items 1 to 3, which is a copolymer obtained by using the same.
Item 6. The fluorine-containing polymer is a polymer obtained by radical polymerization of the fluoroalkyl group-containing acrylic acid ester in the presence of an alkoxysilyl group-containing mercaptan, and further contains an alkoxysilyl group-containing radical as a monomer component. Item 6. The durable waterproof / moisture-proof coating composition according to any one of Items 1 to 3 and 5, which is a copolymer obtained using a polymerizable monomer.
Item 7. The alkoxysilyl group-containing radical polymerizable monomer has the formula (2)

(Wherein R ² , R ³ and R ⁴ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and at least one of R ² , R ³ and R ⁴ is One is an alkoxy group, and R ⁵ is a group containing a radical polymerizable unsaturated bond.), Which is a compound represented by any one of the above items 1 to 4 and 6. Moisture-proof coating composition.
Item 8. An alkoxysilyl group-containing mercaptan is represented by the general formula (3):

(Wherein R ⁷ , R ⁸ and R ⁹ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and at least one of R ⁷ , R ⁸ and R ⁹ is One is an alkoxy group, R ¹⁰ is a linear alkylene group having 1 to 12 carbon atoms, and the compound is represented by any one of the above items 1 to 3, and 5 to 7. Durable waterproof / moisture-proof coating composition.
Item 9. 9. The durable waterproof / moisture-proof coating composition according to any one of 4 to 8 above, wherein the high softening point monomer is a monomer having a glass transition point or a melting point of 100 ° C. or higher of a homopolymer comprising the high softening point monomer. .
Item 10. The fluorine-containing polymer has the following general formula (5):

(In the formula, X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom or a chlorine atom) A cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a straight chain having 1 to 20 carbon atoms Or Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, and 6 to 6 carbon atoms which may have an oxygen atom. 10 aromatic groups, C6-C10 cycloaliphatic groups optionally having oxygen atoms, C6-C10 aromatic aliphatic groups optionally having oxygen atoms, -CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl having 1 to 4 carbon atoms) A —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, and R ² , R ³ and R ⁴ may be the same or different and are alkyl groups having 1 to 4 carbon atoms. A group or an alkoxy group having 1 to 4 carbon atoms, wherein at least one of R ² , R ³ and R ⁴ is an alkoxy group, R ^{5 ′} is derived from a group containing a radically polymerizable unsaturated bond; R ¹¹ is H or CH ₃ and R ¹² is a group having a saturated alkyl group having 4 to 20 carbon atoms and a ratio of carbon atoms to hydrogen atoms of 0.58 or more. , M and n are each an integer of 1 or more, and the sum of l, m and n has a weight average molecular weight of 3,000 to 500. The number of repeating units with l, m, and n in parentheses is arbitrary in the formula.) And has a structural portion represented by 10. The durable waterproof / moisture-proof coating composition according to any one of Items 1 to 4, 7, and 9.
Item 11. The fluorine-containing polymer has the following general formula (6):

(In the formula, X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom or a chlorine atom) A cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a straight chain having 1 to 20 carbon atoms Or Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, and 6 to 6 carbon atoms which may have an oxygen atom. 10 aromatic groups, C6-C10 cycloaliphatic groups optionally having oxygen atoms, C6-C10 aromatic aliphatic groups optionally having oxygen atoms, -CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl having 1 to 4 carbon atoms) A —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, and R ⁷ , R ⁸ and R ⁹ are the same or different and are alkyl groups having 1 to 4 carbon atoms. Or an alkoxy group having 1 to 4 carbon atoms, wherein at least one of R ⁷ , R ⁸ and R ⁹ is an alkoxy group, and R ¹⁰ is a linear alkylene group having 1 to 12 carbon atoms. N is a numerical value having a weight average molecular weight of 3,000 to 500,000.) Any one of the above items 1 to 3, 5 to 9 including a polymer having an alkoxysilyl group at the terminal The durable waterproof / moisture-proof coating composition as described.
Item 12. Item 12. The durable waterproof / moisture-proof coating composition according to any one of Items 1 to 11, wherein the fluorinated solvent is hydrofluoroether.
Item 13. Item 13. The durable waterproof / moisture-proof coating composition according to any one of Items 1 to 12, further comprising a compound having a perfluoropolyether skeleton.
Item 14. 14. The durable waterproof / moisture-proof coating composition according to any one of items 1 to 13, wherein the content of the compound having a perfluoropolyether skeleton is 1 to 20 parts by weight with respect to 100 parts by weight of the fluoropolymer. .
Item 15. Item 15. The durable waterproof / moisture-proof coating composition for connectors of electronic components according to any one of Items 1 to 14, wherein the solid content concentration is 0.2 to 2% by weight.
Item 16. 16. The durable waterproof / moisture-proof coating composition according to any one of items 1 to 15, wherein the object to be treated is an electronic component.
Item 17. 17. A method for forming a durable waterproof / moisture-proof coating, comprising a step of bringing an object to be treated into contact with the durable waterproof / moisture-proof coating composition according to any one of items 1 to 16.
Item 18. Item 18. The method for forming a durable waterproof / moisture-proof coating according to Item 17, wherein the workpiece is an electronic component.
Item 19. Item 16. A connector for electronic parts, wherein a waterproof / moisture-proof coating is formed with the durable waterproof / moisture-proof coating composition according to Item 15.
Item 20. The following general formula (5):

(In the formula, X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom or a chlorine atom) A cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a straight chain having 1 to 20 carbon atoms Or Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, and 6 to 6 carbon atoms which may have an oxygen atom. 10 aromatic groups, C6-C10 cycloaliphatic groups optionally having oxygen atoms, C6-C10 aromatic aliphatic groups optionally having oxygen atoms, -CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl having 1 to 4 carbon atoms) A —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, and R ² , R ³ and R ⁴ may be the same or different and are alkyl groups having 1 to 4 carbon atoms. A group or an alkoxy group having 1 to 4 carbon atoms, wherein at least one of R ² , R ³ and R ⁴ is an alkoxy group, R ^{5 ′} is derived from a group containing a radically polymerizable unsaturated bond; R ¹¹ is H or CH ₃ and R ¹² is a group having a saturated alkyl group having 4 to 20 carbon atoms and a ratio of carbon atoms to hydrogen atoms of 0.58 or more. , M and n are each an integer of 1 or more, and the sum of l, m and n has a weight average molecular weight of 3,000 to 500. In addition, l, m, and n are attached in parentheses and the order of existence of each repeating unit is arbitrary in the formula.) polymer.
Item 21. General formula (6):

(In the formula, X is a fluorine atom or a chlorine atom. Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, and an oxygen atom. An aromatic group having 6 to 10 carbon atoms, a cyclic aliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, and an aromatic aliphatic group having 6 to 10 carbon atoms which may have an oxygen atom A group, —CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl group having 1 to 4 carbon atoms), —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1 to 10), and Rf is a linear or branched group having 1 to 20 carbon atoms. Each of R ⁷ , R ⁸ and R ⁹ is the same or different and is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; ⁷ , at least one of R ⁸ and R ⁹ is an alkoxy group, R ¹⁰ is a linear alkylene group having 1 to 12 carbon atoms, and n is a weight average molecular weight of 3,000 to 500,000. The fluorine-containing polymer represented by.

Hereinafter, the coating composition of the present invention will be specifically described.

Fluoropolymer The fluoropolymer compounded in the coating composition of the present invention has a fluoroalkyl group ester-bonded directly or via a divalent organic group to the carboxyl group, and has a substituent at the α-position. A polymer obtained by using a certain acrylic acid ester (hereinafter sometimes referred to as “fluoroalkyl group-containing acrylic acid ester”) as a monomer component, the alkoxysilyl group-containing acrylic acid ester and the alkoxysilyl group A copolymer obtained by copolymerizing a monomer component containing a containing radical polymerizable monomer, or a polymer obtained by radical polymerization of the fluoroalkyl group-containing acrylic ester in the presence of an alkoxysilyl group-containing mercaptan is there.

Hereinafter, each component for obtaining the fluoropolymer of the present invention will be described.

(I) Monomer component (1) Fluoroalkyl group-containing acrylic ester
Among the monomer components used in the production of the fluoropolymer used in the composition of the present invention, the fluoroalkyl group-containing acrylic ester has a fluoroalkyl group with respect to acrylic acid that may have a substituent at the α-position. An ester bond is formed directly or via a divalent organic group.

As a preferable specific example of the above-mentioned fluoroalkyl group-containing acrylic ester, the following general formula (1):

(In the formula, X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom or a chlorine atom) A cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a straight chain having 1 to 20 carbon atoms Or Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, and 6 to 6 carbon atoms which may have an oxygen atom. 10 aromatic groups, C6-C10 cycloaliphatic groups optionally having oxygen atoms, C6-C10 aromatic aliphatic groups optionally having oxygen atoms, -CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl having 1 to 4 carbon atoms) A —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1). -10), and Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms.

In the general formula (1), the fluoroalkyl group represented by Rf is an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and a perfluoroalkyl group in which all the hydrogen atoms are substituted with fluorine atoms. Is also included.

In the acrylic ester represented by the general formula (1), Rf is a linear or branched group having 4 to 6 carbon atoms in view of good solubility in a fluorinated organic solvent described later, particularly hydrofluoroether. It is preferably a linear fluoroalkyl group, particularly preferably a linear or branched perfluoroalkyl group having 4 to 6 carbon atoms. In the case where Rf is a linear or branched fluoroalkyl group having 4 to 6 carbon atoms, in order to further improve the waterproof resistance of the formed film, in the general formula (1), X The α-substituted acrylate ester in which the α-position substituent represented by is a group or atom other than a hydrogen atom is preferred. In particular, when the α-position substituent X is a methyl group, a chlorine atom or a fluorine atom, a film having good waterproof properties can be formed using a low-cost raw material. In particular, when the α-position substituent X is a methyl group, it is preferable in that the corrosive action on the electronic component is small.

Specific examples of the acrylic acid ester represented by the above general formula (1) are as follows.

The above-mentioned fluoroalkyl group-containing acrylic esters can be used singly or in combination of two or more.

(2) Alkoxysilyl group-containing radical polymerizable monomer The alkoxysilyl group-containing radical polymerizable monomer used in the present invention has the following composition formula (2):

It is represented by In the general formula (2), R ² , R ³ and R ⁴ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and R ² , R ³ and At least one of R ⁴ is an alkoxy group. Examples of the alkoxy group include a methoxy group, methoxy group and the like is preferred, and particularly preferred R ^2, R ³ and R ⁴ are all a methoxy group or an ethoxy group. R ⁵ is a group containing a radically polymerizable unsaturated bond.

By containing the above-mentioned alkoxysilyl group-containing radical polymerizable monomer as a monomer component, a fluorine-containing polymer containing an alkoxysilyl group in the side chain is formed, and this alkoxysilyl group contributes to improvement in adhesion to the substrate. .

Specific examples of the alkoxysilyl group-containing radical polymerizable monomer include monomers represented by the following formulae.

In the above formulas, R ² , R ³ and R ⁴ are the same as above, R ⁶ is a hydrogen atom, a methyl group, or Cl, and n is an integer of 1 to 10.

The above-mentioned alkoxysilyl group-containing radical polymerizable monomers can be used singly or in combination of two or more.

(ii) alkoxysilyl group-containing mercaptan alkoxylyl group-containing mercaptan acts as a chain transfer agent, and adjusts the degree of polymerization of the polymer, part of which is bonded to the fluoropolymer formed, The alkoxysilyl group present at the terminal contributes to the improvement of adhesion to the substrate, and it is possible to produce a fluorine-containing polymer having excellent wear resistance.

The alkoxysilyl group-containing mercaptan can be used without particular limitation as long as it is a compound having an alkoxysilyl group containing at least one alkoxy group and a mercapto group. Preferred alkoxysilyl group-containing mercaptans include the following general formula (3):

The compound represented by these can be mentioned.

In the general formula (3), R ⁷ , R ⁸ and R ⁹ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and R ⁷ , R ⁸ and At least one of R ⁹ is an alkoxy group. As the alkoxy group, a methoxy group is preferable, and it is particularly preferable that all of R ⁷ , R ⁸ and R ⁹ are methoxy groups. R ¹⁰ is a linear alkylene group having 1 to 12 carbon atoms.

The above alkoxysilyl group-containing mercaptans can be used singly or in combination of two or more.

In the alkoxysilyl group-containing mercaptan represented by the general formula (3), R ¹⁰ is preferably a linear alkylene group having 1 to 4 carbon atoms from the viewpoint of solubility in a fluorine-based solvent described later. .

(Iii) Method for Producing Fluoropolymer Hereinafter, for the method for producing the fluoropolymer used in the present invention, a monomer component containing a fluoroalkyl group-containing acrylic acid ester and an alkoxysilyl group-containing radical polymerizable monomer is radically polymerized. The fluorine-containing polymer obtained by radical polymerization of a fluoroalkyl group-containing acrylate ester in the presence of an alkoxysilyl group-containing mercaptan (hereinafter sometimes referred to as “fluorine-containing polymer 1”) (Hereinafter, it may be referred to as “fluorinated polymer 2”).

(1) Fluoropolymer 1
The fluorine-containing polymer 1 can be obtained by radical polymerization of a monomer component containing a fluoroalkyl group-containing acrylic acid ester and an alkoxysilyl group-containing radical polymerizable monomer as essential components.

The use amount of the alkoxysilyl group-containing radical polymerizable monomer is preferably about 0.1 to 20 parts by weight with respect to 100 parts by weight of the fluoroalkyl group-containing acrylic ester used as the monomer component.

In the fluorine-containing polymer 1, in addition to the fluoroalkyl group-containing acrylic ester and the alkoxysilyl group-containing radical polymerizable monomer, a high softening point monomer can be used as a monomer component, if necessary. The high softening point monomer is a monomer having a glass transition point or melting point of a homopolymer composed of the high softening point monomer of 100 ° C or higher, preferably 120 ° C or higher. In this case, the polymer having a glass transition point needs to have a glass transition point of 100 ° C. or higher, and the polymer having no glass transition point needs to have a melting point of 100 ° C. or higher.

The glass transition point and melting point are the extrapolated glass transition end temperature (T _eg ) and melting peak temperature (T _pm ) defined in JIS K7121-1987 “Method for Measuring Plastic Transition Temperature”, respectively.

By using a high softening point monomer satisfying such conditions as a monomer component together with the above-mentioned fluoroalkyl group-containing acrylic acid ester and alkoxysilyl group-containing radical polymerizable monomer, it is formed from the resulting fluorine-containing polymer. The film has excellent waterproof and moistureproof performance. Furthermore, the film formed from the fluoropolymer has improved hardness and good durability such as wear resistance.

In particular, a film formed from a fluorine-containing polymer obtained by using a monomer with a high softening point as a monomer component has a very good dynamic water repellency as an index indicating the performance of removing water droplets attached to the surface of the object to be treated. It is. For this reason, even when water adheres to the surface of an object to be processed such as a printed circuit board, the water drains well and the possibility of failure due to water can be greatly reduced. In addition, about dynamic water repellency, it can evaluate by the falling angle of water described in the Example mentioned later.

The amount of the high softening point monomer used is preferably about 1 to 30 parts by weight, and more preferably about 1 to 20 parts by weight with respect to 100 parts by weight of the fluoroalkyl group-containing acrylate ester.

As the high softening point monomer, in particular, the following general formula (4)
CH ₂ = C (R ¹¹ ) COOR ¹² (4)
(Wherein R ¹¹ is H or CH ₃ , and R ¹² is a group having a saturated alkyl group having 4 to 20 carbon atoms and a ratio of carbon atoms to hydrogen atoms of 0.58 or more). Preferred are (meth) acrylic esters. In the general formula (4), specific examples of the saturated alkyl group having 4 to 20 carbon atoms and a carbon atom to hydrogen atom ratio of 0.58 or more include isobornyl, bornyl, phensil (all of which are C ₁₀ H ₁₇ , Carbon atom / hydrogen atom = 0.58), adamantyl (C ₁₀ H ₁₅ , carbon atom / hydrogen atom = 0.66), norbornyl (C ₇ H ₁₂ , carbon atom / hydrogen atom = 0.58), etc. And a group having a hydrogen ring. These bridged hydrocarbon rings may be directly bonded to the carboxyl group, or may be bonded to the carboxyl group via a linear or branched alkylene group having 1 to 5 carbon atoms. . These bridged hydrocarbon rings may be further substituted with a hydroxyl group or an alkyl group (carbon number, for example, 1 to 5).

Specific examples of the high softening point monomer that can be used in the present invention include methyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate and the like in addition to the (meth) acrylic acid ester represented by the general formula (4). .

Examples of the (meth) acrylic acid ester represented by the general formula (4) include (meth) acrylate having an isobornyl group, (meth) acrylate having a norbornyl group, and (meth) acrylate having an adamantyl group. . Among these, as the (meth) acrylate having a norbornyl group, 3-methyl-norbornylmethyl (meth) acrylate, norbornylmethyl (meth) acrylate, norbornyl (meth) acrylate, 1,3,3- Trimethyl-norbornyl (meth) acrylate, miltanylmethyl (meth) acrylate, isopinocamphanyl (meth) acrylate, 2-{[5- (1 ', 1', 1'-trifluoro-2'-trifluoromethyl-2) '-Hydroxy) propyl] norbornyl} (meth) acrylate and the like, and (meth) acrylate having an adamantyl group may be 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) Acrylate, 3-hydroxy-1-adamantyl (meth) acrylate, 1-adamantyl-α-trifluoromethyl (meth) acrylate Examples include chlorate.

In the present invention, as the monomer component for obtaining the fluorine-containing polymer, other monomers can be used as necessary. The other monomer may be about 20% by weight or less, preferably 10% by weight or less, based on the total amount of monomer components used for obtaining the fluoropolymer.

The other monomer may be any monomer that can be copolymerized with a fluoroalkyl group-containing acrylic acid ester, and can be selected in a wide range as long as the performance of the resulting fluoropolymer is not adversely affected. For example, aromatic alkenyl compounds, vinyl cyanide compounds, conjugated diene compounds, halogen-containing unsaturated compounds, silicon-containing unsaturated compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, allyl ester compounds, unsaturated group-containing ether compounds, maleimides Examples include, but are not limited to, compounds, (meth) acrylic acid esters, acrolein, methacrolein, cyclopolymerizable monomers, N-vinyl compounds, and the like.

The polymerization method is not particularly limited, but it is preferable to perform solution polymerization in a fluorinated solvent. According to this method, since the formed fluorine-containing polymer has good solubility in a fluorine-based solvent, the radical polymerization reaction can proceed smoothly without forming a precipitate.

The fluorine-based solvent may be any of hydrocarbon compounds, alcohols, ethers, etc., as long as it has a fluorine atom in the molecule and the solubility of the formed fluoropolymer is good. Either aliphatic or aromatic may be used. For example, chlorinated fluorinated hydrocarbons (particularly 2 to 5 carbon atoms), especially HCFC225 (dichloropentafluoropropane), HCFC141b (dichlorofluoroethane), CFC316 (2,2,3,3-tetrachlorohexafluorobutane, ), Vertrel XF (chemical formula C ₅ H ₂ F ₁₀ ) (manufactured by DuPont), hexafluoro-m-xylene, pentafluoropropanol, fluorinated ether, and the like can be used.

In particular, when a hydrofluoroether is finally used as a solvent for the target coating composition, the separation step of the fluoropolymer can be omitted by using the same hydrofluoroether as a solvent for the polymerization reaction. Thus, a coating composition can be obtained efficiently.

Fluorine solvents can be used alone or in combination of two or more.

When radically polymerizing a fluoroalkyl group-containing acrylic ester in a fluorine-based solvent, for example, the fluoroalkyl group-containing acrylic ester is dissolved in a solvent, and a polymerization initiator is added while stirring the resulting solution. Thus, the polymerization reaction can be advanced.

The polymerization initiator is not particularly limited as long as it is a known polymerization initiator for radical polymerization reaction. For example, azo initiators such as azobisisobutyronitrile, methyl azoisobutyrate, azobisdimethylvaleronitrile; benzoyl peroxide, potassium persulfate, ammonium persulfate, benzophenone derivatives, phosphine oxide derivatives, benzoketone derivatives, phenylthioether derivatives, Azide derivatives, diazo derivatives, disulfide derivatives and the like can be used. These polymerization initiators can be used singly or in combination of two or more.

The amount of the polymerization initiator used is not particularly limited, but it is usually preferably about 0.01 to 10 parts by weight with respect to 100 parts by weight of the fluoroalkyl group-containing acrylic acid ester used as the monomer component. More preferably, it is about 1 to 1 part by weight.

The concentration of the fluoroalkyl group-containing acrylic ester in the fluorine-based solvent is not particularly limited, but is usually preferably about 10 to 50% by weight, more preferably about 20 to 40% by weight.

The polymerization conditions such as the polymerization temperature and the polymerization time may be appropriately adjusted according to the type of monomer component, the amount used thereof, the type of polymerization initiator, the amount used, etc., but usually about 50 to 100 ° C. The polymerization reaction may be carried out at a temperature for 4 to 10 hours.

The weight average molecular weight of the fluoropolymer 1 obtained by the above-described method is about 3,000 to 500,000, preferably about 5,000 to 300,000. The weight average molecular weight of the fluorine-containing polymer is determined by GPC (gel permeation chromatography) using a mixed solvent of HCFC225 / hexafluoroisopropanol (= 90/10 weight) as an elution solvent (standard polymethyl methacrylate conversion). .

Fluoropolymer 1 obtained by the above-described method is a copolymer having structural units based on a fluoroalkyl group-containing acrylic ester and an alkoxysilyl group-containing radical polymerizable monomer. When a high softening point monomer is used, a structural unit based on the high softening point monomer is included.

Among these, for example, as a high softening point monomer, the copolymer obtained using the (meth) acrylic acid ester represented by the above formula (4) is a structural part represented by the following chemical formula (5). It becomes the copolymer which has. According to this copolymer, it is possible to form a film having excellent abrasion resistance, good waterproof / moisture resistance, and excellent water repellency and good water drainage.

In the above chemical formula (5), X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom, Or a chlorine atom), a cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a carbon number of 1 to 20 These are linear or branched alkyl groups. Y represents a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom, and an oxygen atom. A cyclic aliphatic group having 6 to 10 carbon atoms which may have, an araliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, —CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— A group (wherein R ¹ is an alkyl group having 1 to 4 carbon atoms), a —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or — (CH ₂ ) _n SO ₂ ^— group (n is 1 to 10). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms. R ² , R ³ and R ⁴ are the same or different and are an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and at least one of R ² , R ³ and R ⁴ is an alkoxy group It is a group. R ^{5 ′} is a divalent group derived from the group R ⁵ in the composition formula (2), that is, a divalent group derived from a group containing a radical polymerizable unsaturated bond. R ¹¹ is H or CH ₃ , and R ¹² is a group having a saturated alkyl group having 4 to 20 carbon atoms and a ratio of carbon atoms to hydrogen atoms of 0.58 or more. l, m and n are each an integer of 1 or more, and the sum of l, m and n is a numerical value having a weight average molecular weight of 3,000 to 500,000. Note that the order of presence of each repeating unit with l, m, and n and enclosed in parentheses is arbitrary in the formula.

(2) Fluoropolymer 2
The fluorine-containing polymer 2 can be obtained by radical polymerization of a fluoroalkyl group-containing acrylic ester in the presence of the above-described alkoxysilyl group-containing mercaptan.

The amount of the alkoxysilyl group-containing mercaptan is preferably about 0.01 to 25 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the fluoroalkyl group-containing acrylate ester used as the monomer component. More preferably, it is about part.

In the fluoropolymer 2, as in the fluoropolymer 1, a high softening point monomer and other monomers can be used as a monomer component as necessary. Specific examples of the high softening point monomer and other monomers are the same as those of the fluorinated polymer 1, and the amount used is the same as that of the fluorinated polymer 1.

Furthermore, when the fluorine-containing polymer 2 is produced, the alkoxysilyl group-containing radical polymerizable monomer used in the production of the fluorine-containing polymer 1 may be used as a monomer as necessary. The kind and amount of the alkoxysilyl group-containing radical polymerizable monomer may be the same as those of the fluoropolymer 1. By using the alkoxysilyl group-containing radical polymerizable monomer, the adhesion to the base material is further improved for the fluorinated polymer 2.

The kind and amount of polymerization initiator used are the same as those for fluorinated polymer 1.

Other polymerization conditions may be the same as those for the fluoropolymer 1.

The weight average molecular weight of the fluoropolymer 2 obtained by the above-described method is about 3,000 to 500,000, preferably about 5,000 to 300,000. The weight average molecular weight of the fluorine-containing polymer is determined by GPC (gel permeation chromatography) using a mixed solvent of HCFC225 / hexafluoroisopropanol (= 90/10 weight) as an elution solvent (standard polymethyl methacrylate conversion). .

The fluorine-containing polymer 2 obtained by the above-described method has an alkoxysilyl group-containing mercaptan of the general formula (3) on the polymer chain of the fluoroalkyl group-containing acrylic ester polymer of the general formula (1) used as a monomer. The following general formula (6):

The polymer which has an alkoxy silyl group at the terminal represented by these is included. In the general formula (6), X, Y, Rf, R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are the same as described above, and n is a numerical value corresponding to the weight average molecular weight described above, that is, the general formula (6 The weight average molecular weight of the polymer of) is a value of 3,000 to 500,000.

Further, when a high softening point monomer is used, the fluorine-containing polymer 2 contains a structural unit based on the high softening point monomer in addition to the structure represented by the general formula (6). When the containing radical polymerizable monomer is used, it has a structural unit based on the alkoxysilyl group-containing radical polymerizable monomer.

In addition, as described above, in the general formula (6), the polymer in which X is a chlorine atom or a fluorine atom is obtained using a low-cost raw material, and is highly useful for forming a film having good waterproof properties. It is a polymer and is a novel polymer that has not been known so far.

Durable waterproof / moisture-proof coating composition The coating composition of the present invention is obtained by dissolving the fluorinated polymer 1 or the fluorinated polymer 2 obtained by the above-described method in a fluorinated solvent.

The fluorine-containing polymer 1 and the fluorine-containing polymer 2 obtained by the method described above both have good water repellency by containing a fluoroalkyl group, and the film formed from the polymer has good waterproof performance. Indicates.

Furthermore, the fluorine-containing polymer 1 obtained by using an alkoxysilyl group-containing radical polymerizable monomer as a monomer component exhibits good binding properties to various substrates due to the alkoxysilyl group present in the side chain. At the same time, the film has crosslinkability, and the formed film has good wear resistance and waterproof / moisture-proof performance.

In the fluorine-containing polymer 2 obtained by performing the radical polymerization reaction in the presence of the alkoxysilyl group-containing mercaptan, at least a part of the alkoxysilyl group-containing mercaptan existing during the polymerization reaction is bonded to the polymer chain, The alkoxysilyl group present in the polymer exhibits good binding properties to various substrates and has crosslinkability. As a result, the formed film has excellent wear resistance, and the waterproof / moisture-proof performance is also improved.

Furthermore, when a high softening point monomer is used as the monomer component, the water repellency of the formed film is improved for both the fluorine-containing polymer 1 and the fluorine-containing polymer 2, and water drainage is improved.

In the waterproof / moisture-proof coating composition of the present invention, by using a fluorine-based solvent, the above-mentioned fluorine-containing polymer can be stably dissolved, and a coating composition having good stability in which precipitation or the like hardly occurs. Can do.

The fluorine-based solvent may be any of hydrocarbon compounds, alcohols, ethers, etc., as long as it has a fluorine atom in the molecule and the solubility of the formed fluoropolymer is good. Either aliphatic or aromatic may be used. For example, chlorinated fluorinated hydrocarbons (particularly 2 to 5 carbon atoms), especially HCFC225 (dichloropentafluoropropane), HCFC141b (dichlorofluoroethane), CFC316 (2,2,3,3-tetrachlorohexafluorobutane, ), Vertrel XF (molecular formula C ₅ H ₂ F ₁₀ ) (manufactured by DuPont), hexafluoro-m-xylene, pentafluoropropanol, fluorine ether, and the like can be used.

In the present invention, it is particularly preferable to use hydrofluoroether as the fluorinated solvent. Hydrofluoroether is a solvent having low chemical erosion with respect to various materials, and is a particularly suitable solvent as a solvent for coating compositions for electronic components that are strongly required to eliminate the adverse effects of the solvent. Further, hydrofluoroether is an ideal solvent having excellent performance such as quick drying, low environmental pollution, nonflammability, and low toxicity.

In the present invention, as the hydrofluoroether,
_{Formula: C m F 2m + 1 -O} -C z H 2z + 1
[Wherein, m is a number from 1 to 6, and z is a number from 1 to 6. ]
The compound shown by these is preferable. Examples of such hydrofluoroethers include Novec HFE7100 (chemical formula C ₄ F ₉ OCH ₃ ), 7200 (chemical formula C ₄ F ₉ OC ₂ H ₅ ), 7300 (chemical formula C ₂ F ₅ CF (OCH ₃ ) C ₃ F ₇ ) can be used.

In the present invention, in particular, in the general formula (1), Rf is a linear or branched fluoroalkyl group having 4 to 6 carbon atoms, and X is a group or atom other than a hydrogen atom. A coating composition in which a fluoropolymer obtained by using a fluoroalkyl group-containing acrylic acid ester as a monomer component is dissolved in hydrofluoroether is preferred. The fluorine-containing polymer formed from an α-substituted fluoroalkyl group-containing acrylate ester in which Rf is a fluoroalkyl group having 4 to 6 carbon atoms has good solubility in hydrofluoroether, and the film formed is Thus, the film has excellent waterproofness and moisture resistance, and has excellent wear resistance with good bondability to the substrate.

In the coating composition of the present invention, the concentration of the fluorine-containing polymer in the composition is preferably about 0.01 to 30% by weight, and preferably about 0.1 to 20% by weight as the solid content concentration. More preferred. In particular, when the object to be processed is a connector of an electronic component or the like, by setting the solid content concentration to about 0.2 to 2% by weight, the wear resistance is good and the waterproofing is excellent without impairing the conductivity. And a film having moisture-proof performance can be formed.

The coating composition of the present invention may be used as a coating composition as it is after the radical polymerization reaction in the fluorinated solvent by the above-described method, and after adjusting the concentration of the polymer as necessary. After the radical polymerization reaction, the fluorine-containing polymer is separated, and then dissolved in a fluorine-based solvent to form a coating composition. In the present invention, in particular, after performing a polymerization reaction using hydrofluoroether as a solvent, if necessary, by adjusting the polymer concentration using hydrofluoroether to obtain a coating composition, the object can be efficiently obtained. Coating composition can be obtained.

In the coating composition of the present invention, a compound having a perfluoropolyether (PFPE) skeleton (hereinafter sometimes referred to as “PFPE compound”) can be further blended as necessary. By blending the PFPE compound, the slipperiness of the film formed from the fluorine-containing polymer is improved, and the wear resistance is greatly improved.

In the present invention, as the PFPE compound, a compound represented by the following general formula (7) can be used.

A ¹ -B ¹ -R ^a -B ² -A ² (7)
In the above formula, A ¹ and A ² are the same or different and are a C _1-16 alkyl group which may be substituted with one or more fluorine atoms, or a group: —SiQ _k Y ^a _3-k ( In the formula, Y ^a represents a hydroxyl group, a hydrolyzable group, or a hydrocarbon group, Q represents —Z ^a —SiR ^b _j R ^c _3-j (Z ^a represents a divalent organic group, R ^b Is a hydroxyl group or a hydrolyzable group, R ^c is a C _1-22 alkyl group or Q ′, Q ′ is synonymous with Q, and j is independently 0 to 0 in each Q and Q ′. And the sum of j is 1 or more), and k is an integer of 1 to 3. B ¹ and B ² are the same or different and each represents a single bond or a divalent organic group, and Ra represents ^a perfluoropolyether group.

In the above formula (7), among the groups represented by ^{A 1} and ^{A 2,} _{"C 1-16} alkyl group at one or more of the good _{C 1-16} alkyl group optionally substituted by a fluorine atom "Is a linear or branched alkyl group having 1 to 16 carbon atoms, preferably a linear or branched alkyl group having 1 to 3 carbon atoms, more preferably a linear carbon number. 1 to 3 alkyl groups.

The C _1-16 alkyl group substituted by one or more fluorine atoms is preferably a CF ₂ H—C _1-15 perfluoroalkylene group, more preferably a C _1-16 perfluoroalkyl group. It is.

The C _1-16 perfluoroalkyl group is a linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, preferably a linear or branched perfluoroalkyl group having 1 to 3 carbon atoms. More preferably a linear perfluoroalkyl group having 1 to 3 carbon atoms, specifically —CF ₃ , —CF ₂ CF ₃ , or —CF ₂ CF ₂ CF ₃ .

In the above formula (7), R ^a is a perfluoropolyether group. Specifically, for example, — (OC ₄ F ₈ ) _a — (OC ₃ F ₆ ) _b — (OC ₂ F ₄ ) _c — (OCF ₂ ) _d — is represented. Here, a, b, c and d are each independently an integer of 0 or 1 and are not particularly limited as long as the sum of a, b, c and d is at least 1. Preferably, each independently represents an integer of 0 or more and 200 or less, more preferably, each independently represents an integer of 0 or more and 100 or less, and more preferably, the sum of a, b, c and d is 10 or more. 100 or less. Further, the order of presence of each repeating unit with a, b, c or d in parentheses is arbitrary in the formula. Among these repeating units, — (OC ₄ F ₈ ) — represents — (OCF ₂ CF ₂ CF ₂ CF ₂ ) —, — (OCF (CF ₃ ) CF ₂ CF ₂ ) —, — (OCF ₂ CF (CF ₃ ) CF ₂ )-,-(OCF ₂ CF ₂ CF (CF ₃ ))-,-(OC (CF ₃ ) ₂ CF ₂ )-,-(OCF ₂ C (CF ₃ ) ₂ )-,-(OCF (CF ₃ ) CF (CF ₃ ))-,-(OCF (C ₂ F ₅ ) CF ₂ )-and-(OCF ₂ CF (C ₂ F ₅ ))-may be used, but preferably — (OCF ₂ CF ₂ CF ₂ CF ₂ ) —. -(OC ₃ F ₆ )-is any of-(OCF ₂ CF ₂ CF ₂ )-,-(OCF (CF ₃ ) CF ₂ )-and-(OCF ₂ CF (CF ₃ ))- Preferably, it is — (OCF ₂ CF ₂ CF ₂ ) —. In addition, — (OC ₂ F ₄ ) — may be any of — (OCF ₂ CF ₂ ) — and — (OCF (CF ₃ )) —, preferably — (OCF ₂ CF ₂ ) —. is there.

In one embodiment, R ^a is — (OC ₃ F ₆ ) _b — (wherein b is an integer of 1 or more), preferably — (OCF ₂ CF ₂ CF ₂ ) _b —.

In another embodiment, R ^a is — (OC ₂ F ₄ ) _c — (OCF ₂ ) _d — (wherein c and d are each independently an integer of 1 or more, and a subscript c or d is attached). The order of presence of each repeating unit in parentheses is arbitrary in the formula), and is preferably — (OCF ₂ CF ₂ ) _c — (OCF ₂ ) _d —. In this embodiment, R ^a is a small amount of — (OC ₄ F ₈ ) _a — (preferably — (OCF ₂ CF ₂ CF ₂ CF ₂ ) _a —) and — (OC ₃ F ₆ ) _b — ( Preferably,-(OCF ₂ CF ₂ CF ₂ ) _b- ) may be contained, and for example, (a + b) / (a + b + c + d) may be contained at a ratio of 0.3 or less.

In the above formula (7), B ¹ and B ² are the same or different and represent a direct bond or a divalent organic group.

The above “divalent organic group” means a divalent group containing carbon as used herein. Such a divalent organic group is not particularly limited, and examples thereof include a divalent group obtained by further removing one hydrogen atom from a hydrocarbon group.

The “hydrocarbon group” as used herein means a group containing carbon and hydrogen. Such hydrocarbon group is not particularly limited, but may be a hydrocarbon group having 1 to 20 carbon atoms which may be substituted by one or more substituents, such as an aliphatic hydrocarbon group, An aromatic hydrocarbon group etc. are mentioned. The “aliphatic hydrocarbon group” may be linear, branched or cyclic, and may be either saturated or unsaturated. The hydrocarbon group may also contain one or more ring structures. Such a hydrocarbon group may have one or more N, O, S, Si, amide, sulfonyl, siloxane, carbonyl, carbonyloxy and the like at the terminal or molecular chain.

The substituent of the “hydrocarbon group” is not particularly limited. For example, a halogen atom; a C _1-6 alkyl group which may be substituted with one or more halogen atoms, C _2-6 alkenyl group, C _2-6 alkynyl group, C _3-10 cycloalkyl group, C _3-10 unsaturated cycloalkyl group, 5-10 membered heterocyclyl group, 5-10 membered unsaturated heterocyclyl group, C _Examples include _6-10 aryl group, 5- to 10-membered heteroaryl group, and the like.

B ¹ and B ² are preferably a direct bond, a C _1-20 alkylene group, or — (CH ₂ ) _s —X ″ — (CH ₂ ) _t —. In the above formula, X ″ is — O—, or — (Si (R ^d ) ₂ O) _v — or —O— (CH ₂ ) _u — (Si (R ^d ) ₂ O) _v — (wherein R ^d is Each independently represents a C _1-6 alkyl group, v represents an integer of 1 to 100, and u represents an integer of 1 to 20, preferably —O—. s is an integer of 1 to 20, preferably an integer of 1 to 3, more preferably 1 or 2. t is an integer of 1 to 20, preferably an integer of 2 to 3. These groups may be substituted with one or more substituents selected from a fluorine atom and a C _1-3 alkyl group.

Specific examples of B ¹ and B ² include, in addition to direct bonding, for example:
—CH ₂ O (CH ₂ ) ₃ —,
—CH ₂ O (CH ₂ ) ₆ —,
—CH ₂ O (CH ₂ ) ₃ Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ (CH ₂ ) ₂ —,
_{-CH 2 O (CH 2) 3} Si (CH 3) 2 OSi (CH 3) 2 OSi (CH 3) 2 (CH 2) 2 -,
-CH ₂ O (CH ₂ ) ₃ Si (CH ₃ ) ₂ O (Si (CH ₃ ) ₂ O) ₂ Si (CH ₃ ) ₂ (CH ₂ ) _2- ,
—CH ₂ O (CH ₂ ) ₃ Si (CH ₃ ) ₂ O (Si (CH ₃ ) ₂ O) ₃ Si (CH ₃ ) ₂ (CH ₂ ) ₂ —,
—CH ₂ O (CH ₂ ) ₃ Si (CH ₃ ) ₂ O (Si (CH ₃ ) ₂ O) ₁₀ Si (CH ₃ ) ₂ (CH ₂ ) ₂ —,
—CH ₂ O (CH ₂ ) ₃ Si (CH ₃ ) ₂ O (Si (CH ₃ ) ₂ O) ₂₀ Si (CH ₃ ) ₂ (CH ₂ ) ₂ —
In the above formula (7), among the groups represented by A ¹ and A ² , Y ^a in the group: Y ^a _3-k Q _k Si— represents ^a hydroxyl group, a hydrolyzable group, or Represents a hydrocarbon group. The hydroxyl group is not particularly limited, but may be a group produced by hydrolysis of a hydrolyzable group.

The “hydrolyzable group” as used herein means a group capable of leaving from the main skeleton of a compound by a hydrolysis reaction. Such hydrolyzable groups are not particularly limited, but include —OR ^e , —OCOR ^e , —O—N═C (R ^e ) ₂ , —N (R ^e ) ₂ , —NHR ^e , A halogen atom (in these formulas, R ^e independently represents a substituted or unsubstituted C _1-3 alkyl group at each occurrence).

Y ^a is preferably a hydroxyl group, —O (R ^f ) (wherein R ^f represents a C _1-12 alkyl group, preferably a C _1-6 alkyl group, more preferably a C _1-3 alkyl group). ), A C _1-12 alkyl group, a C _2-12 alkenyl group, a C _2-12 alkynyl group, or a phenyl group, and more preferably —OCH ₃ , —OCH ₂ CH ₃ , —OCH (CH ₃ ) ₂ It is. These groups may be substituted with, for example, one or more substituents selected from a fluorine atom, a C _1-6 alkyl group, a C _2-6 alkenyl group, and a C _2-6 alkynyl group. .

In the formula (7), Q in the group: Y ^a _3-k Q _k Si— represents —Z ^a —SiR ^b _j R ^c _3-j .

Z ^a represents a divalent organic group independently at each occurrence.

The Z ^a is preferably free of those which form siloxane bonds and a terminal Si atoms of the molecular backbone in the formula (7).

Z ^a is preferably a C _1-6 alkylene group, or — (CH ₂ ) _{s ′} —O— (CH ₂ ) _{t ′} — (wherein s ′ is an integer of 1 to 6, 'Is an integer of 1 to 6, and more preferably a C _1-3 alkylene group. These groups may be substituted with, for example, one or more substituents selected from a fluorine atom, a C _1-6 alkyl group, a C _2-6 alkenyl group, and a C _2-6 alkynyl group. .

R ^b represents a hydroxyl group or a hydrolyzable group independently at each occurrence. Preferably, R ^b is —OR ^g (wherein R ^g represents a substituted or unsubstituted C _1-3 alkyl group, more preferably a methyl group).

R ^c represents each independently a C _1-22 alkyl group or Q ′ at each occurrence. Q ′ has the same meaning as Q.

J is an integer independently selected from 0 to 3 in each Q and Q ', and the sum of j is 1 or more. In each Q or Q ′, when j is 0, Si in Q or Q ′ does not have a hydroxyl group or a hydrolyzable group. Therefore, the total sum of j must be at least 1 or more.

In Q ′ at the end of the chain −QQ ′ _0-5 chain bonded to the Si atom at the end of the molecular main chain having a perfluoropolyether group, the above n is preferably 2, more preferably 3. is there.

When at least one of R ^c in Q is Q ′, there are two or more Si atoms linked in a straight chain via a Z group in Q. The maximum number of Si atoms connected in a straight chain via the Z group is five.

In one embodiment, the number of Si atoms linearly linked via a Z ^a group in Q is 1 (i.e., Si atoms in Q is present only one) or two.

In the above formula (7), k is an integer selected from 1 to 3, preferably 2 or more, more preferably 3. By setting k to 3, the bond with the substrate becomes strong and high wear resistance can be obtained.

In one embodiment, the PFPE compound used in the present invention is a compound represented by the formula (7), wherein R ^c in Q is a C _1-22 alkyl group.

In one embodiment, the PFPE compound used in the present invention is a compound represented by the formula (7), wherein at least one of R ^c in Q is Q ′.

The PFPE compound represented by the above formula (7) is not particularly limited, but may have an average molecular weight of 5 × 10 ² to 1 × 10 ⁵ . Among these ranges, an average molecular weight of 1,000 to 30,000 is preferable from the viewpoint of wear resistance. In the present invention, “average molecular weight” means number average molecular weight, and “average molecular weight” is a value measured by ¹⁹ F-NMR.

In the coating composition of the present invention, when the PFPE compound is blended, the blending amount of the PFPE compound is 100 parts by weight of the fluorinated polymer contained in the composition in order to sufficiently exhibit the effect of improving the wear resistance. The amount is preferably about 1 to 20 parts by weight.

The application object of the coating composition of the present invention is not particularly limited, and a film having excellent wear resistance and excellent waterproof and moisture proof performance can be formed on various base materials such as plastic, metal, and ceramics. In particular, when processing electronic parts including connectors, housings, printed boards, semiconductors, etc., by using the coating composition of the present invention, it is possible to use a solvent having low chemical erosion resistance and wear resistance. Since a waterproof and moisture-proof coating having excellent properties can be formed, good waterproof and moisture-proof performance can be imparted without impairing the performance of the electronic component.

The treatment method using the coating composition of the present invention is not particularly limited, and the coating composition of the present invention may be brought into contact with the object to be treated. Usually, after the object to be treated is immersed in the coating composition of the present invention, it may be dried in the atmosphere having a humidity of about 20 to 70% or more. In addition, a method of bringing the coating composition of the present invention into contact with an object to be treated by a method such as brush coating, spraying, spin coating, or the like can also be applied.

As a result, the alkoxysilane group introduced into the polymer terminal or side chain of the fluorine-containing polymer contained in the coating composition of the present invention is hydrolyzed by moisture in the atmosphere and converted into a silanol group, which reacts with the substrate. , Adhesion is improved. In addition, silanol groups that have reacted with the base material are condensed and crosslinked two-dimensionally or three-dimensionally to form a strong film.

There is no particular limitation on the temperature during the treatment, and the treatment may be usually performed at room temperature. The treatment time is not particularly limited. For example, in the case of the dipping method, the dipping time may be about 1 second to 24 hours.

In order to form a film having higher wear resistance, the substrate was washed with acetone, hydrofluoroether or the like in order to remove oil on the substrate surface prior to the treatment with the coating composition of the present invention. Thereafter, it is preferable to dry. Furthermore, in addition to the above cleaning, pretreatment with UV ozone, oxygen plasma or the like can further improve the wear resistance of the coating.

In addition, prior to the treatment with the coating composition of the present invention, if necessary, by applying a primer treatment to the object to be treated, the binding property of the film formed from the coating composition is improved and the wear resistance is increased. The sex can be further improved. The primer treatment may be performed under the same conditions as the primer treatment in the case of using a silane coupling agent according to a conventional method.

According to the waterproof / moisture-proof coating composition of the present invention, waterproof and moisture-proof coatings excellent in abrasion resistance can be formed on various substrates. In particular, when hydrofluoroether is used as a solvent, a good waterproof and moisture-proof coating can be formed without causing chemical erosion on the substrate and without adversely affecting the environment.

Furthermore, when a PFPE compound is blended, the slipperiness of the film formed from the fluorine-containing polymer is improved, and the wear resistance is greatly improved.

For this reason, according to the waterproof / moisture-proof coating composition of the present invention, particularly when electronic components are treated, good waterproof and moisture-proof performance having wear resistance without impairing the performance of the electronic components. Can be given.

The graph which shows the relationship between the immersion time in HFE7200 and the ratio with respect to the initial contact angle with respect to a water static contact angle in Examples 1-6 and Comparative Examples 1-3. The graph which shows the relationship between the frequency | count of wiping in Examples 7-8 and Comparative Examples 4-6 and the ratio with respect to the initial contact angle with respect to a water static contact angle. 14 is a graph showing the relationship between the number of wears in Examples 11 to 13 and Comparative Example 10 and the ratio of the static contact angle to water to the initial contact angle. The graph which shows the relationship between the frequency | count of wear in Examples 14-16 and Comparative Examples 11-13, and the ratio with respect to the initial contact angle with respect to a water static contact angle.

Hereinafter, the present invention will be described in more detail with reference to production examples and examples.

Production Example 1 (Rf (C6) α-Cl acrylate / MPS = 100 / 5.21 (weight ratio) polymer)
In a four-necked flask, α-chloroacrylic acid (perfluorohexyl) ethyl (CH ₂ = C (Cl) COOCH ₂ CH ₂ C ₆ F ₁₃ : hereinafter abbreviated as “Rf (C6) α-Cl acrylate”. 35 g), mercaptopropyltrimethoxysilane (hereinafter sometimes abbreviated as “MPS”) 1.824 g, and perfluorohexyl methyl ether (C ₂ F ₅ CF (OCH ₃ ) C ₃ F ₇ : “HFE7300” (It may be abbreviated) 66 g was charged, nitrogen purged for 10 minutes, and heated to 80 ° C. To this, 0.127 g of azobisisobutyronitrile (hereinafter sometimes abbreviated as “AIBN”) was added and reacted for 6 hours.

After cooling to room temperature, the fluoropolymer was precipitated with methanol and dried under reduced pressure. This was diluted with perfluorobutyl ethyl ether (C ₄ F ₉ OC ₂ H ₅ : sometimes abbreviated as “HFE7200”) to prepare a solution having a predetermined concentration used in Examples described later.

As a result of measuring the molecular weight by GPC using a fluorinated solvent [HCFC225 / hexafluoroisopropanol = 90/10 (weight)] as an eluent, the weight average molecular weight was 22,100.

Production Example 2 (Rf (C6) α-Cl acrylate / MPS = 100 / 3.08 (weight ratio) polymer)
A fluorine-containing polymer was synthesized in the same manner as in Production Example 1 except that the amount of MPS used was 1.079 g, and a HFE 7200 solution having a predetermined concentration used in Examples described later was prepared. The weight average molecular weight of the obtained polymer was 36,900.

Production Example 3 (Rf (C6) α-Cl acrylate / MPS = 100 / 1.04 (weight ratio) polymer)
A fluorine-containing polymer was synthesized by the same method as in Production Example 1 except that the amount of MPS used was 0.365 g, and a HFE 7200 solution having a predetermined concentration used in Examples described later was prepared. The weight average molecular weight of the obtained polymer was 42,300.

Production Example 4 (Rf (C6) methacrylate / MPS = 100 / 1.04 (weight ratio) polymer)
In Production Example 1, instead of Rf (C6) α-Cl acrylate, methacrylic acid (perfluorohexyl) ethyl (CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₆ F ₁₃ : hereinafter, “Rf (C6) The HFE7200 solution having a predetermined concentration used in Examples described later was prepared in the same manner as in Production Example 1 except that the amount of MPS used was 0.365 g. The weight average molecular weight of the obtained polymer was 6,800.

Production Example 5 (Rf (C6) methacrylate / MPS = 100 / 0.45 (weight ratio) polymer)
A fluorine-containing polymer was synthesized by the same method as in Production Example 4 except that the amount of MPS used was 0.159 g, and a HFE 7200 solution having a predetermined concentration used in Examples described later was prepared. The weight average molecular weight of the obtained polymer was 13,400.

Production Example 6 (Rf (C6) methacrylate / MPS = 100 / 0.23 (weight ratio) polymer)
A fluorine-containing polymer was synthesized by the same method as in Production Example 4 except that the amount of MPS used was 0.080 g to prepare a HFE7200 solution having a predetermined concentration. The weight average molecular weight of the obtained polymer was 25,000.

Production Example 7 (Rf (C6) methacrylate / iBMA / MPS = 100 / 14.58 / 1.424 (weight ratio) polymer)
In a four-necked flask, 60.24 g of Rf (C6) methacrylate, isobornyl methacrylate (hereinafter sometimes abbreviated as iBMA) 8.78 g, MPS 0.858 g, and perfluorobutyl ethyl ether (C ₄ F ₉ OC ₂ H ₅ : Hereinafter, 280.0 g) (which may be abbreviated as “HFE7200”) was charged, and nitrogen was purged for 10 minutes and heated to 70 ° C. AIBN 0.298g was thrown into this and it reacted for 6 hours.

After cooling to room temperature, a part of the reaction solution was taken out on an aluminum cup and dried at 110 ° C. for 1 hour at normal pressure, thereby calculating the resin solids concentration of the polymer in the polymerization solution. Thereafter, the polymerization solution was diluted with a predetermined amount of HFE7200 to prepare a solution having a predetermined concentration used in Examples described later.

As a result of measuring the molecular weight by GPC in the same manner as in Production Example 1, the weight average molecular weight of the obtained polymer was 16,700.

Production Example 8 (Rf (C6) methacrylate / iBMA / MPS / TMSMA = 100 / 14.58 / 1.507 / 2.383 (weight ratio) polymer)
In a four-necked flask, 0.772 g of Rf (C6) methacrylate, 4.48 g of iBMA, 0.463 g of MPS, 3- (trimethoxysilyl) propyl methacrylate (hereinafter sometimes abbreviated as “TMSMA”), And HFE7200140.6g were charged and nitrogen purged for 10 minutes and heated to 70 ° C. This was charged with 0.156 g of AIBN and reacted for 6 hours.

After cooling to room temperature, the resin solid content concentration of the polymer in the polymerization solution was calculated in the same manner as in Production Example 7. Thereafter, the polymerization solution was diluted with a predetermined amount of HFE7200 to prepare a solution having a predetermined concentration used in Examples described later.

As a result of measuring the molecular weight by GPC in the same manner as in Production Example 1, the weight average molecular weight of the obtained polymer was 14,200.

Production Example 9 Rf (C6) methacrylate / iBMA / TMSMA = 100 / 14.49 / 2.373 (weight ratio) polymer)
A four-necked flask was charged with 91.81 g of Rf (C6) methacrylate, 13.30 g of iBMA, 2.179 g of TMSMA, and HFE7200420.03 g, and was purged with nitrogen for 10 minutes and heated to 70 ° C. AIBN 0.464g was thrown into this and it reacted for 6 hours.

After cooling to room temperature, the resin solid content concentration of the polymer in the polymerization solution was calculated in the same manner as in Production Example 7. Thereafter, the polymerization solution was diluted with a predetermined amount of HFE7200 to prepare a solution having a predetermined concentration used in Examples described later.

As a result of measuring the molecular weight by GPC in the same manner as in Production Example 1, the weight average molecular weight of the obtained polymer was 118,800.

Comparative Production Example 1 (Rf (C6) α-Cl acrylate / MPS = 100/0 (weight ratio) polymer)
Without using MPS, a fluoropolymer was synthesized in the same manner as in Production Example 1 except that, and a HFE7200 solution having a predetermined concentration used in a comparative example described later was prepared. The weight average molecular weight of the obtained polymer was 171,900.

Comparative Production Example 2 (Rf (C6) methacrylate / MPS = 100/0 (weight ratio) polymer)
Without using MPS, a fluorine-containing polymer was synthesized in the same manner as in Production Example 4 except that, and a HFE7200 solution having a predetermined concentration used in Comparative Examples described later was prepared. The weight average molecular weight of the obtained polymer was 269,600.

Comparative Production Example 3 (Rf (C8) methacrylate / MPS = 100/0 (weight ratio) polymer)
In Production Example 1, instead of Rf (C6) α-Cl acrylate, perfluorooctyl methacrylate (CH ₂ = C (CH ₃ ) COOC ₈ F ₁₇ : hereinafter, abbreviated as “Rf (C8) methacrylate”. The HFE7200 solution having a predetermined concentration used in a comparative example described later was prepared in the same manner as in Production Example 1 except that MPS was not used. The weight average molecular weight of the obtained polymer was 228,300.

Comparative Production Example 4 Rf (C6) methacrylate / iBMA / TMSMA = 100 / 14.49 / 0 (weight ratio) polymer)
Without using TMSMA, the fluoropolymer was synthesized in the same manner as in Production Example 9 except that, and the resin solid content concentration of the polymer after polymerization was calculated in the same manner as in Production Example 7. Then, the solution of the predetermined concentration used in the Example mentioned later was prepared by diluting the solution which calculated resin solid content concentration with HFE7200.

The weight average molecular weight of the obtained polymer was 115,000.

Examples 1 to 6 and Comparative Examples 1 to 3
A silicon wafer was used as an object to be processed, and ultrasonic cleaning was performed in acetone for 30 minutes, followed by immersion in HFE7200, followed by drying to perform pretreatment.

The silicon wafer pretreated by the above-described method was immersed in an HFE7200 solution (resin solid content concentration 0.2% by weight) of each fluoropolymer obtained in Production Examples 1 to 6 and Comparative Production Examples 1 to 3. Then, it was left to stand for a whole day and night in the atmosphere (20 ° C., humidity 30%) to prepare a test piece.

For each of these test pieces, the static contact angle with water was measured to determine the initial contact angle, and then immersed in HFE7200 at room temperature (20 ° C.) for a predetermined time. Then, after raising in the atmosphere and leaving to stand for 1 minute, the static contact angle with respect to water was measured, the ratio to the initial contact angle was calculated, and thereby the durability against the solvent was evaluated. Tables 1 and 2 below show the immersion time in HFE7200 and the ratio of the static contact angle to water relative to the initial contact angle. FIG. 1 shows the immersion time in HFE7200 and the static contact angle to water. The relationship with the ratio with respect to an initial contact angle is shown as a graph.

The film thickness calculated by measuring the unevenness prepared by cutting the thin film formed on the silicon wafer with a cutter knife with the above-described method with a laser microscope VK-9710 (manufactured by KEYENCE) was about 50 nm. It was.

As is clear from the above results, according to the coating liquids of Production Examples 1 to 6, the fluoropolymer obtained by polymerizing the fluoroalkyl group-containing acrylic ester in the presence of MPS was dissolved in hydrofluoroether. It can be seen that a water-repellent film excellent in solvent immersion durability can be formed.

Examples 7 to 8 and Comparative Examples 4 to 6
Using the HFE7200 solution of each fluoropolymer obtained in Production Examples 2 and 5 and the HFE7200 solution of each fluoropolymer obtained in Comparative Production Examples 1 to 3, a silicon wafer was prepared in the same manner as in Example 1. A test piece was prepared by dipping treatment.

For each of these test pieces, the static contact angle against water was measured to determine the initial contact angle. (Trademark name: Kimwipe, Nippon Paper Crecia Co., Ltd.) is attached, the surface is wiped a predetermined number of times with a load of 100 g, then the static contact angle with water is measured, and the ratio to the initial contact angle is calculated and wiped off. Abrasion resistance was evaluated. Table 3 below shows the number of wiping times and the ratio of the static contact angle to the initial contact angle, and FIG. 2 is a graph showing the relationship between the number of wiping times and the ratio of the static contact angle to the initial contact angle. Show.

As is apparent from the above results, it can be seen that the coating liquids obtained in Production Examples 2 and 5 can form a water-repellent film excellent in abrasion resistance against wiping.

Examples 9 to 10 and Comparative Examples 7 to 9
Using the HFE7200 solution of each fluorine-containing polymer obtained in Production Examples 2 and 5 and the HFE7200 solution of each fluorine-containing polymer obtained in Comparative Production Examples 1 to 3, moisture resistance and rust prevention were achieved by the following methods. evaluated. The results are shown in Table 4 below.

* Evaluation method of moisture resistance The moisture resistance was evaluated by moisture permeability (cup method, JIS Z0208). The moisture permeability (g / m ² · day) is defined by the amount of water vapor that permeates the moisture-proof film, and the smaller the value, the better the moisture-proof property.

As a test method, a moisture-permeable waterproof sheet for building materials (JIS A6111 · 2004 compliant product) cut into a circle (diameter 70 mm) is used as a support sheet, and a 2 wt% HFE7200 solution of each fluoropolymer is used. The film was formed on a moisture permeable waterproof sheet by spin coating, and the moisture permeability was measured. The transmittance of the support sheet alone was about 4000 g / m ² · day.

* Evaluation method of rust prevention The rust prevention was evaluated by the salt spray test (JIS Z 2371) under the following conditions.
Specimen angle: 20 ± 5 ° to the vertical axis
Salt concentration: 5% by weight, pH 6.5-7.2
Spray temperature: 60 ± 1 ° C
As a substrate, a JIS H 3100 (C1100P) buffing process, a copper substrate of size 2.0 × 15 × 60 mm (manufactured by Nippon Test Panel Industry), made by dipping once in a 2% HFE7200 solution of each fluoropolymer A film was formed (film thickness about 100 nm). After spraying with salt water, the appearance after 96 hours was evaluated in five stages: ◎ (no change at all), ○, Δ, ×, XX (severe discoloration = untreated).

As is clear from the above results, it can be seen that the coating liquid obtained in Production Examples 2 and 5 can form a film excellent in moisture resistance and rust resistance.

Although it is not clear why the moisture resistance is good, the alkoxysilane group at the end of the polymer crosslinks the polymer molecules and contributes to improving the adhesion between the polymer and the substrate. It is estimated that

Examples 11 to 13 and Comparative Example 10
A silicon wafer is dipped in the same manner as in Example 1 using the HFE7200 solution of each fluoropolymer obtained in Production Examples 7 to 9 and the HFE7200 solution of each fluoropolymer obtained in Comparative Production Example 4. Thus, a test piece was prepared.

For each of these test pieces, the wear resistance was evaluated by the same method as in Examples 7 to 8 and Comparative Examples 4 to 6, using a load of 500 g and a friction element as steel wool. Table 5 below shows the number of wear and the ratio of static contact angle with water to the initial contact angle when the friction piece is made of steel wool. FIG. 3 shows the number of wear and initial contact with static contact angle with water. The relationship with the ratio to the corner is shown as a graph.

As is apparent from the above results, it was found that the coating liquids obtained in Production Examples 7 to 9 can form a water-repellent film excellent in wear resistance when steel wool is used as a friction element.

Examples 14 to 16 and Comparative Examples 11 to 13
Preparation of fluoropolymer HFE7200 solution (resin solid content concentration 2% by weight) obtained in Production Example 9 and preparation of fluoropolymer HFE7200 solution (resin solid content concentration 2% by weight) obtained in Comparative Production Example 4 did. Also, the HFE7200 solution of these fluoropolymers and the HFE7200 solution of the compound having a perfluoropolyether (PFPE) skeleton (resin solid content concentration 2 wt%) were mixed at a weight ratio of 90/10 to obtain a resin solid content. A 2% strength by weight solution was prepared. As the compound having a perfluoropolyether (PFPE) skeleton, a silane compound having a PFPE skeleton (manufactured by Daikin Industries, Optool DSX) and unmodified PFPE oil (manufactured by Daikin Industries, demnum S-20) were used. (Hereafter, OPTOOL DSX may be abbreviated as DSX, and demnum S-20 as S-20.)
Using these solutions, a silicon wafer was dipped in the same manner as in Example 1 to prepare test pieces. For each of the obtained test pieces, the wear resistance was evaluated in the same manner as in Examples 7 to 8 and Comparative Examples 4 to 6, using a load of 250 g and a friction element of steel wool. Table 6 below shows the number of wear and the ratio of static contact angle with water to the initial contact angle when the friction piece is made of steel wool, and Fig. 4 shows the number of wear and initial contact with water static contact angle. The relationship with the ratio to the corner is shown as a graph.

As is clear from the above results, the test pieces (Examples 14 and 15) prepared with the blend solution of the fluoropolymer and the PFPE compound were more steel wool than the Examples 16 and Comparative Production Examples 11 to 13 to which PFPE was not added. It was found that a water-repellent film excellent in wear resistance when using as a friction element can be formed.

Example 17 and Comparative Example 14
After charging a commercially available smartphone (Samsung Galaxy S II), the power was turned off, and the micro USB part was placed vertically so that it faced up. The coating agent of Production Example 9 adjusted to various concentrations (0.1, 0.2, 0.5, 1, 2, 5, 10% by weight) or the coating agent of Comparative Production Example 4 is dropped inside the plug fitting opening of the micro USB receptacle. Immediately after filling in, the smartphone was rotated so that the micro USB opening faced downward, and the coating agent was discharged to coat the inside of the plug fitting opening. After the treatment, it was treated for 1 hour in an environment of a temperature of 25 ° C. and a humidity of 60%, and then the following tests were performed.
-Initial evaluation The degree of initial conductivity was evaluated by measuring the contact resistance of the electrode (5 poles). When the contact resistance of both 5 poles is less than 50 mΩ, the continuity is good (◯), and when 1 pole is 50 mΩ or more, the continuity is poor (×). Next, stand vertically so that the micro USB is facing upward, fill the inside of the plug fitting with a dropper, then immediately turn the micro USB downward and drop it onto the desk from a height of 1 cm. The water was discharged. The method of visually repelling water remaining in the plug fitting opening (water repellency) was visually determined according to the following criteria. The higher the water repellency, the less water droplets remain inside the plug fitting opening, which means that the electrode is less susceptible to electric field corrosion.
A: Plays very well (contact angle 110 °)
○: Play well (contact angle of about 100 °)
△: Play (contact angle about 90 °)
×: (Contact angle 50 ~ 80 °)
XX: (Contact angle 50 ° or less)
-Insertion / removal test The contact resistance was measured after inserting / removing the plug into / from the waterproof micro USB 5000 times. Next, water repellency was evaluated in the same manner as in the initial stage. Next, the smartphone was turned on, placed vertically so that the micro USB was facing upward, tap water was filled into the plug fitting opening with a dropper, and then left for 10 minutes with water still inside. Tap water was discharged by turning the micro USB downward and dropping it onto a desk from a height of 1 cm. The presence or absence of electric field corrosion was determined by observing the degree of discoloration of the USB electrode with a stereomicroscope (30 times magnification) in the following five stages.
A: No discoloration O: Slight discoloration Δ: Slight discoloration x: Discoloration xx: Severe discoloration The test results are shown in Table 7 below.

As is clear from the above results, when the coating agent of Production Example 9 was used, better results were obtained for water repellency and electric field corrosion than when the coating agent of Comparative Production Example 4 was used. It was. In particular, in the coating agent of Production Example 9, in the range where the solid content concentration of the coating agent was 0.2 to 2% by weight, the initial electrical conductivity was secured, the water repellency after the insertion / extraction test was good, and the electric field corrosion was difficult to occur. .

Claims (21)

1. (I) radical polymerization of a fluoroalkyl group-containing acrylate ester having a fluoroalkyl group ester-bonded directly or via a divalent organic group to a carboxyl group and having a substituent at the α-position A polymer obtained, which is a fluoropolymer comprising the polymer shown in the following (1) or (2): (1) a monomer containing the fluoroalkyl group-containing acrylic acid ester and an alkoxysilyl group-containing radical polymerizable monomer A polymer obtained by radical polymerization of components,
   (2) a polymer obtained by radical polymerization of the fluoroalkyl group-containing acrylic acid ester in the presence of an alkoxysilyl group-containing mercaptan;
   And (II) a durable waterproof / moisture-proof coating composition characterized by containing a fluorine-based solvent.
2. The fluoroalkyl group-containing acrylic ester is represented by the following general formula (1):
   

   

   (In the formula, X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom or a chlorine atom) A cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a straight chain having 1 to 20 carbon atoms Or Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom, or an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom An aliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, an araliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, —CH ₂ CH ₂ N ( R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl group having 1 to 4 carbon atoms) A —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1 to 10); 2. The durable waterproof / moisture-proof coating composition according to claim 1, wherein Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms.
3. The fluoroalkyl group-containing acrylic ester is an α-position in which Rf is a linear or branched fluoroalkyl group having 4 to 6 carbon atoms and X is an atom or group other than hydrogen in the general formula (1) The durable waterproof / moisture-proof coating composition according to claim 2, wherein is a substituted carboxylic acid ester.
4. The fluorine-containing polymer is a polymer obtained by radical polymerization of a monomer component containing a fluoroalkyl group-containing acrylic acid ester and an alkoxysilyl group-containing radical polymerizable monomer, The durable waterproof / moisture-proof coating composition according to any one of claims 1 to 3, which is a copolymer obtained using a softening point monomer.
5. The fluorine-containing polymer is a polymer obtained by radical polymerization of the fluoroalkyl group-containing acrylic ester in the presence of an alkoxysilyl group-containing mercaptan, and further, a monomer component having a high softening point monomer The durable waterproof / moisture-proof coating composition according to any one of claims 1 to 3, which is a copolymer obtained by use.
6. The fluorine-containing polymer is a polymer obtained by radical polymerization of the fluoroalkyl group-containing acrylic acid ester in the presence of an alkoxysilyl group-containing mercaptan, and further contains an alkoxysilyl group-containing radical as a monomer component. The durable waterproof / moisture-proof coating composition according to any one of claims 1 to 3 and 5, which is a copolymer obtained by using a polymerizable monomer.
7. The alkoxysilyl group-containing radical polymerizable monomer has the formula (2)
   

   

   (Wherein R ² , R ³ and R ⁴ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and at least one of R ² , R ³ and R ⁴ is 7. The durable waterproof / reactive compound according to claim 1, wherein one is an alkoxy group, and R ⁵ is a group containing a radical polymerizable unsaturated bond. Moisture-proof coating composition.
8. An alkoxysilyl group-containing mercaptan is represented by the general formula (3):
   

   

   (Wherein R ⁷ , R ⁸ and R ⁹ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and at least one of R ⁷ , R ⁸ and R ⁹ is One is an alkoxy group, and R ¹⁰ is a linear alkylene group having 1 to 12 carbon atoms. Durable waterproof / moisture-proof coating composition.
9. 9. The durable waterproof / moisture-proof coating composition according to any one of 4 to 8 above, wherein the high softening point monomer is a monomer having a glass transition point or a melting point of 100 ° C. or higher of a homopolymer comprising the high softening point monomer. .
10. The fluorine-containing polymer has the following general formula (5):
    

    

    (In the formula, X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom or a chlorine atom) A cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a straight chain having 1 to 20 carbon atoms Or Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, and 6 to 6 carbon atoms which may have an oxygen atom. 10 aromatic groups, C6-C10 cycloaliphatic groups optionally having oxygen atoms, C6-C10 aromatic aliphatic groups optionally having oxygen atoms, -CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl having 1 to 4 carbon atoms) A —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, and R ² , R ³ and R ⁴ may be the same or different and are alkyl groups having 1 to 4 carbon atoms. A group or an alkoxy group having 1 to 4 carbon atoms, wherein at least one of R ² , R ³ and R ⁴ is an alkoxy group, R ^{5 ′} is derived from a group containing a radically polymerizable unsaturated bond; R ¹¹ is H or CH ₃ and R ¹² is a group having a saturated alkyl group having 4 to 20 carbon atoms and a ratio of carbon atoms to hydrogen atoms of 0.58 or more. , M and n are each an integer of 1 or more, and the sum of l, m and n has a weight average molecular weight of 3,000 to 500. The number of repeating units with l, m, and n in parentheses is arbitrary in the formula.) And has a structural portion represented by The durable waterproof / moisture-proof coating composition according to any one of claims 1 to 4, 7, and 9.
11. The fluorine-containing polymer has the following general formula (6):
    

    

    (In the formula, X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom or a chlorine atom) A cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a straight chain having 1 to 20 carbon atoms Or Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, and 6 to 6 carbon atoms which may have an oxygen atom. 10 aromatic groups, C6-C10 cycloaliphatic groups optionally having oxygen atoms, C6-C10 aromatic aliphatic groups optionally having oxygen atoms, -CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl having 1 to 4 carbon atoms) A —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, and R ⁷ , R ⁸ and R ⁹ are the same or different and are alkyl groups having 1 to 4 carbon atoms. Or an alkoxy group having 1 to 4 carbon atoms, wherein at least one of R ⁷ , R ⁸ and R ⁹ is an alkoxy group, and R ¹⁰ is a linear alkylene group having 1 to 12 carbon atoms. N is a numerical value having a weight average molecular weight of 3,000 to 500,000.) The polymer represented by any one of claims 1 to 3, and 5 to 9, comprising a polymer having an alkoxysilyl group at the terminal. The durable waterproof / moisture-proof coating composition as described.
12. The durable waterproof / moisture-proof coating composition according to any one of claims 1 to 11, wherein the fluorinated solvent is hydrofluoroether.
13. The durable waterproof / moisture-proof coating composition according to any one of claims 1 to 12, further comprising a compound having a perfluoropolyether skeleton.
14. The durable waterproof / moisture-proof coating composition according to claim 1, wherein the content of the compound having a perfluoropolyether skeleton is 1 to 20 parts by weight with respect to 100 parts by weight of the fluoropolymer. .
15. The durable waterproof / moisture-proof coating composition for connectors of electronic components according to any one of claims 1 to 14, wherein the solid content concentration is 0.2 to 2% by weight.
16. The durable waterproof / moisture-proof coating composition according to any one of claims 1 to 15, wherein the object to be treated is an electronic component.
17. A method for forming a durable waterproof / moisture-proof coating, comprising a step of bringing a treatment object into contact with the durable waterproof / moisture-proof coating composition according to any one of claims 1 to 16.
18. The method for forming a durable waterproof / moisture-proof film according to claim 17, wherein the object to be processed is an electronic component.
19. The connector of the electronic component in which the waterproof / moisture-proof film was formed with the durable waterproof / moisture-proof coating composition of Claim 15.
20. The following general formula (5):
    

    

    (In the formula, X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a CFX ¹ X ² group (provided that X ¹ and X ² are the same or different and are a hydrogen atom, a fluorine atom or a chlorine atom) A cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a straight chain having 1 to 20 carbon atoms Or Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, and 6 to 6 carbon atoms which may have an oxygen atom. 10 aromatic groups, C6-C10 cycloaliphatic groups optionally having oxygen atoms, C6-C10 aromatic aliphatic groups optionally having oxygen atoms, -CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl having 1 to 4 carbon atoms) A —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, and R ² , R ³ and R ⁴ may be the same or different and are alkyl groups having 1 to 4 carbon atoms. A group or an alkoxy group having 1 to 4 carbon atoms, wherein at least one of R ² , R ³ and R ⁴ is an alkoxy group, R ^{5 ′} is derived from a group containing a radically polymerizable unsaturated bond; R ¹¹ is H or CH ₃ and R ¹² is a group having a saturated alkyl group having 4 to 20 carbon atoms and a ratio of carbon atoms to hydrogen atoms of 0.58 or more. , M and n are each an integer of 1 or more, and the sum of l, m and n has a weight average molecular weight of 3,000 to 500. In addition, l, m, and n are attached in parentheses and the order of existence of each repeating unit is arbitrary in the formula.) polymer.
21. General formula (6):
    

    

    (In the formula, X is a fluorine atom or a chlorine atom. Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, and an oxygen atom. An aromatic group having 6 to 10 carbon atoms, a cyclic aliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, and an aromatic aliphatic group having 6 to 10 carbon atoms which may have an oxygen atom A group, —CH ₂ CH ₂ N (R ¹ ) SO ₂ ^— group (where R ¹ is an alkyl group having 1 to 4 carbon atoms), —CH ₂ CH (OY ¹ ) CH ₂ ^— group (where Y ¹ is a hydrogen atom or an acetyl group), or a — (CH ₂ ) _n SO ₂ ^— group (n is 1 to 10), and Rf is a linear or branched group having 1 to 20 carbon atoms. Each of R ⁷ , R ⁸ and R ⁹ is the same or different and is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; ⁷ , at least one of R ⁸ and R ⁹ is an alkoxy group, R ¹⁰ is a linear alkylene group having 1 to 12 carbon atoms, and n is a weight average molecular weight of 3,000 to 500,000. The fluorine-containing polymer represented by.

Images