JP6350161B2 - Waterproof and moisture-proof durable coating composition - Google Patents

Description

  The present invention is (i) excellent in storage stability before use, and (ii) chemically bonded to various metal substrates at the time of use, through solvent immersion, immersion in water, wiping, abrasion, high temperature and high humidity, etc. It also relates to a coating composition that imparts waterproof and moisture-proof properties that can also be sustained; and weather resistance, salt water and corrosion resistance to hydrogen sulfide gas.

  In recent years, with the proliferation of multifunctional portable information terminals represented by smartphones and tablets, a method for imparting waterproofness and moistureproofness to various metal substrates incorporated therein has become an issue. Since these devices have a large number of electronic components built in and arranged in a small housing, there are almost no extra gaps, and the gaps are a slight gap of 100 μm or less. For this reason, it is difficult to provide a waterproof / moisture-proof performance by packing with a conventionally used silicone rubber. In addition, non-fluorine-based waterproof / moisture-proof coatings represented by HumiSeal (manufactured by Chase Corp. in the United States) are not suitable unless they are made with a very thick thick film of 100 μm or more. is not.

  A fluorine-based waterproof / moisture-proof coating agent in which a copolymer obtained by radical polymerization of a monomer component containing fluoroalkyl (meth) acrylate is dissolved in a fluorine-based solvent is sufficient for a waterproof / moisture-proof coating with a film thickness of 1 μm or less. Since the performance can be demonstrated, the use to a multifunctional portable information terminal attracts attention (patent document 1). However, conventional fluorine-based waterproof / moisture-proof coating agents do not have sufficient wear resistance, and workers and assembly equipment accidentally touch the waterproof / moisture-proof parts on the production line, or waterproof / moisture-proof charging connectors and earphones. When a consumer repeatedly uses a part such as a jack that requires insertion / extraction, the fluorine-based coating agent is peeled off, and the initial waterproof / moisture-proof performance cannot be maintained.

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 durability with respect to various metal substrates, such as solvent immersion, immersion in water, wiping, abrasion, and high temperature and high humidity. It is an object of the present invention to provide a coating composition having excellent storage stability, which can form a film having excellent waterproof and moistureproof performance.

  The inventors of the present invention have intensively studied to achieve the above-described object. As a result, an acrylic ester having a fluoroalkyl group as the first monomer and having a substituent at the α-position is further used as the second monomer, and (1) one or more in the molecule Using at least one of a monomer containing a phosphate ester having a radical polymerizable group of (2) and (2) a monomer containing an acetoacetoxy group having one or more radical polymerizable groups in the molecule, It has been found that the fluorine-containing polymer obtained by radical polymerization is excellent in storage stability, in particular, excellent in adhesion to aluminum, and has excellent durability after coating. Furthermore, the inventors of the present invention are more effective than the case where the skeleton provided with at least one of a phosphate group and an acetoacetoxy group is added with an alkoxysilane group in the same manner as described above. It has been found that the adhesiveness to the metal substrate is developed. Furthermore, it discovered that the adhesiveness was improved by including the monomer which has a diester structure in a polymer frame | skeleton. Therefore, the present invention has been completed based on these findings.

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) a fluorine-containing polymer,
(A) a fluorine-containing acrylic ester having a fluoroalkyl group or a fluoropolyether group ester-bonded to a carboxyl group directly or via a divalent organic group and having a substituent at the α-position;
And (b-1) a phosphate ester having one or more radically polymerizable groups in the molecule, and / or (b-2) a acetoacetoxyester having one or more radically polymerizable groups in the molecule. A coating composition comprising a fluorine-containing polymer which is a copolymer obtained by radical polymerization of a monomer component and (II) a fluorine-based solvent.
Item 2. The fluorine-containing acrylic ester (a) 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, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom, a —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (provided that , 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 — (CH ₂ ) _n SO ₂ — group (n is 1 to 10), and Rf is a straight chain having 1 to 20 carbon atoms. Or a branched fluoroalkyl group or a fluoropolyether group having a molecular weight of 400 to 5,000.) The coating composition according to Item 1 above.
Item 3. The fluorine-containing acrylate ester (a) is represented by the general formula (1), wherein Rf is a linear or branched fluoroalkyl group having 4 to 6 carbon atoms, and X is an atom or group other than hydrogen. Item 3. The coating composition according to Item 2, wherein the position is a substituted carboxylic acid ester.
Item 4. The fluorine-containing polymer is further used as a monomer component.
(C) The coating composition according to any one of Items 1 to 3, which is a copolymer obtained using a high softening point monomer.
Item 5. Item 5. The item according to any one of Items 1 to 4, wherein the fluorine-containing polymer is a copolymer obtained by using at least one compound represented by the following general formula (2) as the phosphate ester (b-1). Coating composition

(In the formula, R ² is a group containing a radically polymerizable unsaturated bond, and when there are plural groups, each may be the same or different, and n is 0, 1 or 2. .)
Item 6. The fluorine-containing polymer is a phosphoric ester (b-1), a compound (b-1-1) represented by the formula (2) where n = 2 and a compound represented by the formula (2) where n = 1 ( Item 6. The coating composition according to Item 5, which is a copolymer obtained by using a mixture containing each of b-1-2).
Item 7. A mixture in which the fluorine-containing polymer contains 40 mol% to 95 mol% of the compound (b-1-1) and 5 mol% to 60 mol% of the compound (b-1-2) as the phosphate ester (b-1) is used. Item 7. The coating composition according to Item 6, which is a copolymer obtained in the above step.
Item 8. The fluorine-containing polymer is a copolymer obtained by using, as the phosphate ester (b-1), a compound represented by at least the above general formula (2), wherein R ² is a methacryloyloxyalkyl group. Item 7. The coating composition according to Item 5 or 6.
Item 9. Item 9. The item according to any one of Items 1 to 8, wherein the fluorine-containing polymer is a copolymer obtained by using at least one compound represented by the following general formula (3) as acetoacetoxy ester (b-2). Coating composition

(In the formula, Z is a direct bond, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom, a —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (where R ¹ is carbon Or 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 —. A group (n is 1 to 10),
R ³ is have an oxygen atom and a hydrocarbon group which may having 1 to 10 carbon atoms, and R ⁴ is a group containing a radical-polymerizable unsaturated bond. ).
Item 10. 10. The coating composition according to any one of Items 4 to 9, 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 composed of the high softening point monomer.
Item 11. Item 11. The coating composition according to any one of Items 1 to 10, wherein the fluorine-containing polymer has a crosslinked structure.
Item 12. The fluorine-containing polymer has the following general formula (4):

(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, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur 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 -} .Rf 1 carbon atoms which is (n 1 to 10) Linear or branched fluoroalkyl group having 20 or a fluoropolyether group having a molecular weight of 400 to 5,000 .R 2 ^'is trivalent group derived from a group containing a radical-polymerizable unsaturated bond In the case where a plurality of them are present, they may be the same or different, and R ⁵ is H or CH ₃ , and R ⁶ is a carbon atom having 4 to 20 carbon atoms with respect to a hydrogen atom. A group having a saturated alkyl group with a ratio of 0.58 or more, j, k and m are each an integer of 1 or more, l is 0 or an integer of 1 or more, and j, k, l and m are the sum Is a numerical value with a weight average molecular weight of 3,000 to 500,000, where j, k, l, and m are attached and parenthesized parentheses are present in any order in the formula. Having a structural part represented by In it, the coating composition according to claim 1.
Item 13. The fluorine-containing polymer has the following general formula (5):

(Wherein j, k and m are each an integer of 1 or more, l is 0 or an integer of 1 or more, and the sum of j, k, l and m has a weight average molecular weight of 3,000 to 500, 000. It should be noted that the order of existence of each repeating unit in parentheses with j, k, l, and m attached is arbitrary in the formula.) Item 2. The coating composition according to Item 1, wherein the coating composition is.
Item 14. 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. And Y and Z are the same or different and each represents a direct bond, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, —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 — (CH ₂ ) _n SO ₂ — group (where n is 1 to 1). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, or a fluoropolyether group having a molecular weight of 400 to 5,000, and R ^{2 ′} represents a radical polymerizable unsaturated bond. And a trivalent group derived from the containing group, and when there are a plurality of groups, each may be the same or different, and R ³ may have an oxygen atom. R ^{4 ′} is a group containing a radically polymerizable unsaturated bond, R ⁵ is H or CH ₃ , and R ⁶ is a carbon atom having 4 to 20 carbon atoms with respect to a hydrogen atom. A group having a saturated alkyl group having a carbon atom ratio of 0.58 or more, j, m and n are each an integer of 1 or more, k and l are 0 or an integer of 1 or more, and j, k, l , M and n have a weight average molecular weight of 3,000 to 500,000. Note that the order of existence of each repeating unit in parentheses with j, k, l, m, and n attached thereto is arbitrary in the formula.) The coating composition according to Item 1, wherein
Item 15. The fluorine-containing polymer has the following general formula (7):

(Wherein j, m and n are each an integer of 1 or more, k and l are 0 or an integer of 1 or more, and the sum of j, k, l, m and n has a weight average molecular weight of 3,000. It is a numerical value of ˜500,000, where the order of presence of each repeating unit in parentheses with j, k, l, m and n attached thereto is arbitrary in the formula. Item 2. The coating composition according to Item 1, wherein the coating composition has a structural portion.
Item 16. Item 16. The coating composition according to any one of Items 1 to 15, wherein the fluorinated solvent is hydrofluoroether.
Item 17. The coating composition according to any one of Items 1 to 16, further comprising a compound having a perfluoropolyether skeleton.
Item 18. Item 18. The coating composition according to Item 17, 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 19. Item 19. The coating composition for connectors for electronic components according to any one of Items 1 to 18, wherein the solid content concentration is 0.2 to 10% by weight.
Item 20. Item 20. The coating composition according to any one of Items 1 to 19, wherein the workpiece is an electronic component.
Item 21. 21. A method for forming a durable waterproof / moisture-proof coating, comprising a step of bringing a treatment object into contact with the coating composition according to any one of Items 1 to 20.
Item 22. Item 22. The method for forming a durable waterproof / moisture-proof coating according to Item 21, wherein the workpiece is an electronic component.
Item 23. Item 20. A connector for electronic parts, wherein a waterproof / moisture-proof coating is formed by the coating composition according to any one of items 1 to 19.
Item 24. The following general formula (4):

(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, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur 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 carbon number A linear or branched fluoroalkyl group having 1 to 20 or a fluoropolyether group having a molecular weight of 400 to 5,000, and R ^{2 ′} is a trivalent group derived from a group containing a radical polymerizable unsaturated bond. And when there are a plurality of them, they may be the same or different, R ⁵ is H or CH ₃ , R ⁶ is a carbon atom having 4 to 20 carbon atoms and a hydrogen atom. A group having a saturated alkyl group having an atomic ratio of 0.58 or more, wherein j, k, and m are each an integer of 1 or more, l is 0 or an integer of 1 or more, and j, k, l, and m Is a numerical value having a weight average molecular weight of 3,000 to 500,000, wherein the order of presence of each repeating unit in parentheses with j, k, l, and m attached is given in the formula The fluorine-containing polymer represented by
Item 25. A fluorine-containing polymer,
(A) a fluorinated acrylate ester having a fluoroalkyl group or a fluoropolyether group ester-bonded to the carboxyl group directly or via a divalent organic group and having a substituent at the α-position; and (B-2) A fluorine-containing polymer that is a copolymer obtained by radical polymerization of a monomer component containing an acetoacetoxy ester having one or more radical polymerizable groups in the molecule.
Item 26. 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. And Y and Z are the same or different and each represents a direct bond, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, —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 — (CH ₂ ) _n SO ₂ — group (where n is 1 to 1). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, or a fluoropolyether group having a molecular weight of 400 to 5,000, and R ^{2 ′} represents a radical polymerizable unsaturated bond. And a trivalent group derived from the containing group, and when there are a plurality of groups, each may be the same or different, and R ³ may have an oxygen atom. R ^{4 ′} is a group containing a radically polymerizable unsaturated bond, R ⁵ is H or CH ₃ , and R ⁶ is a carbon atom having 4 to 20 carbon atoms with respect to a hydrogen atom. A group having a saturated alkyl group having a carbon atom ratio of 0.58 or more, j and m are each an integer of 1 or more, k, l and n are 0 or an integer of 1 or more, and j, k, l , M and n have a weight average molecular weight of 3,000 to 500,000. Is a value to be used. In addition, j, k, l, the order of the repeating units in parentheses are denoted respectively m and n are arbitrary in the formula.) Fluorine-containing polymer represented by.
Item 27. The method for producing a fluorine-containing polymer according to any one of Items 1 to 15,
(A) a fluorine-containing acrylate ester having a fluoroalkyl group or a fluoropolyether group ester-bonded to a carboxyl group directly or via a divalent organic group and having a substituent at the α-position; b) A production method comprising the step of radical polymerization of a monomer component containing a phosphate ester having one or more radically polymerizable groups in the molecule.

  According to the present invention, in the waterproof / moisture-proof coating composition, (i) the storage stability before use can be improved, and (ii) the film formed after use is immersed in a solvent, immersed in water, wiped, worn and Water and moisture resistance that can be maintained even after high temperature and high humidity, and weather resistance, salt water, and corrosion resistance to hydrogen sulfide gas can be imparted.

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

It is drawing which shows the result by washing | cleaning solvent HFE7200 independent washing | cleaning of an Example, The error bar in a figure has shown the maximum value and minimum value at the time of a measurement. It is drawing which shows the result by washing | cleaning solvent HFE7200 / IPA (= 9/1 weight ratio) of an Example, The error bar in a figure has shown the maximum value and minimum value at the time of a measurement.

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

Fluoropolymer The fluoropolymer to be blended in the coating composition of the present invention has a fluoroalkyl group or a fluoropolyether group that is ester-bonded directly or via a divalent organic group to the carboxyl group, and is in the α-position. An acrylic ester that may have a substituent (hereinafter sometimes referred to as “fluorinated acrylic ester”) is used as the first monomer component, and it further has one or more radically polymerizable groups in the molecule. At least one of a monomer component containing a phosphate ester and a monomer component containing an acetoacetoxy ester having one or more radical polymerizable groups in the molecule is used as a second monomer component. It is a copolymer obtained by polymerization.

  Hereinafter, each component for obtaining the fluorine-containing polymer of the present invention will be described.

(I) Monomer component (1) Fluorinated acrylic ester (a)
Among the monomer components used in the production of the fluoropolymer used in the composition of the present invention, the fluorine-containing acrylic ester (a) is a fluoroalkyl group with respect to acrylic acid which may have a substituent at the α-position. Alternatively, a fluoropolyether group is ester-bonded directly or via a divalent organic group.

  As a preferable specific example of the above-mentioned fluorine-containing acrylic acid ester (a), 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, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur 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 - is a group (n is 1 to 10), Rf is C 1 -C Linear or branched fluoroalkyl group having 20 or a fluoropolyether group having a molecular weight of 400-10,000.) Acrylic acid ester represented by the exemplified.

  In the above, the hydrocarbon group may be cyclic or non-cyclic, and may be either linear or branched.

  In the general formula (1), the fluoroalkyl group is an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and includes a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. . The fluoropolyether group is a polyether group in which at least one hydrogen atom is substituted with a fluorine atom, and includes a perfluoropolyether group in which all hydrogen atoms are substituted with fluorine atoms.

In the acrylic ester represented by the general formula (1), Rf is a linear or branched group having 4 to 6 carbon atoms in that it has good solubility in a fluorinated organic solvent described later, particularly hydrofluoroether. It is preferably a linear fluoroalkyl group, and 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 waterproofness of the formed film, in the general formula (1), X is The α-substituted acrylate ester in which the α-position substituent represented 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 acrylate ester represented by the 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.

  When the Rf group is a fluoropolyether group, the molecular weight of the fluoropolyether group is 400 to 10,000, and a perfluoropolyether group is preferable. A perfluoropolyether group having 6 to 8 carbon atoms is particularly preferred. Specific examples are given below.

  The perfluoropolyether group-containing acrylic acid ester described above can be used alone or in combination of two or more.

(2) Phosphate ester (b-1) having one or more radically polymerizable groups in the molecule
The phosphoric ester (b-1) used in the present invention is represented by the following general formula (2)

It is represented by In the general formula (2), R ² is a group containing a radical polymerizable unsaturated bond, and when there are a plurality of R ^{2 s} , each may be the same or different, and n is 0, 1 or 2.

  By containing the above-mentioned phosphate ester (b-1) as a monomer component, a fluorine-containing polymer containing a phosphate group in the side chain is formed, and this phosphate group has adhesion to a metal substrate, particularly aluminum. Contributes to improvement.

  Specific examples of the phosphate ester (b-1) include compounds represented by the following formulae.

(In the formula, n ¹ is 4 or 5, and n ² is 5 or 6.)
The above-mentioned phosphate ester (b-1) can be used singly or in combination of two or more.

  The fluorine-containing polymer of the present invention is represented by the compound (b-1-1) represented by the formula (2) where n = 2 and the formula (2) where n = 1 as the phosphate ester (b-1). It is preferable that the copolymer is obtained using a mixture containing each of the compounds (b-1-2), since a fluorine-containing polymer having better adhesion to a metal substrate (particularly aluminum) can be obtained.

The compound (b-1-2) has two groups R ² containing a radically polymerizable unsaturated bond. For this reason, the copolymer of this invention obtained using a compound (b-1-2) has a crosslinked structure. Therefore, the copolymer of this invention obtained using a compound (b-1-2) contains a high molecular weight component. This is considered to contribute to the improvement of the adhesion between the coating thin film and the metal substrate.

  In the above, the fluorine-containing polymer is 40 to 95 mol% (preferably 60 to 75 mol%) of the compound (b-1-1) and 5 to 60 mol% (preferably 25 or less) as the phosphate ester (b-1). A copolymer obtained by using a mixture containing each of (˜45 mol%) compound (b-1-2) is preferred in terms of adhesion to a metal substrate (particularly aluminum).

Copolymer obtained by using the fluorine-containing polymer of the present invention as a phosphate ester (b-1), which is a compound represented by at least the above general formula (2), wherein R ² is a methacryloyloxyethyl group A coalescence is preferable because a fluorine-containing polymer having better adhesion to a metal substrate (particularly aluminum) can be obtained.

(3) Acetoacetoxy ester (b-2) having one or more radical polymerizable groups in the molecule
The acetoacetoxy ester (b-2) used in the present invention is represented by the following general formula (3)

It is represented by In the above general formula (3), Z represents a direct bond, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom, a —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (provided that 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 — (CH ₂ ). _n SO ₂ — group (n is 1 to 10).
R ³ is a C 1-10 hydrocarbon group which may have an oxygen atom.
R ⁴ is a group containing a radical polymerizable unsaturated bond.

  In the above, the hydrocarbon group may be cyclic or non-cyclic, and may be either linear or branched.

  Specific examples of the acetoacetoxy ester (b-2) include 2-acetoacetoxyethyl methacrylate (AAEM) represented by the following formula, acetoacetoxyethyl acrylate, acetoacetoxypropyl acrylate, acetoacetoxypropyl methacrylate, N- (2-acetoacetoxyethyl) acrylamide, N- (2-acetoacetoxyethyl) methacrylamide, vinyl acetoacetate, allyl acetoacetate and the like can be mentioned. Examples include acetoacetoxyethyl (meth) acrylate and acetoacetoxypropyl (meth) acrylate.

  By containing the above-mentioned acetoacetoxy ester (b-2) as a monomer component, a fluorine-containing polymer containing an acetoacetoxy group in the side chain is formed, and this acetoacetoxy group has adhesiveness to a metal substrate, particularly copper. Contributes to improvement.

  The fluorine-containing polymer of the present invention may be a copolymer obtained by using a mixture containing a phosphate ester (b-1) or an acetoacetoxy ester (b-2), or a phosphate ester (b-1 And a copolymer obtained using a mixture containing acetoacetoxy ester (b-2). If it is a copolymer obtained using the mixture containing phosphate ester (b-1), there exists a tendency for the adhesiveness with respect to aluminum to improve, and the copolymer obtained using the mixture containing acetoacetoxyester (b-2) is used. Since the adhesion to copper tends to be improved in the case of a polymer, which one is used can be appropriately determined depending on which metal substrate is required to have adhesion.

  If the fluorine-containing polymer of the present invention has a crosslinked structure in the polymer skeleton, it is crosslinked at a part between the polymer chains, and a high molecular weight product is formed, so that the adhesion to the metal substrate is improved. There is a tendency to improve. Therefore, even if it is a copolymer obtained using the mixture containing either phosphate ester (b-1) and acetoacetoxy ester (b-2), if it has a crosslinked structure, it is more. Since there exists a tendency for the adhesiveness with respect to a metal base material to improve, it is preferable.

  In particular, the fluorine-containing polymer of the present invention is a phosphoric ester (b-1) represented by the formula (2) where n = 2 and the formula (2) where n = 1 And a copolymer obtained by using a mixture containing each of the compounds (b-1-2) and acetoacetoxy ester (b-2), a plurality of types of metal substrates (for example, single This is preferable because a fluorine-containing polymer having excellent adhesion to one-element metal silicon, aluminum, copper, and multi-element stainless steel (SUS) can be obtained.

(Iii) Method for Producing Fluoropolymer The fluoropolymer of the present invention is obtained by radical polymerization of a monomer component containing fluorinated acrylate ester (a) and phosphate ester (b-1) as essential components. be able to.

  It is preferable that the usage-amount of phosphoric ester (b-1) shall be about 0.1-20 weight part with respect to 100 weight part of fluorine-containing acrylic ester (a) used as a monomer component.

  In addition to the fluorine-containing acrylic ester (a) and the phosphoric ester (b-1), a high softening point monomer can be used as a monomer component as 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 the 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 fluorinated acrylic ester (a) and phosphoric ester (b-1), it is formed from the resulting fluorinated polymer. The coating 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 fluorine-containing acrylic ester (a). .

  As the high softening point monomer, in particular, the following general formula (8)

(Wherein R ⁵ is H or CH ₃ , and R ⁶ 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 (8), specific examples of the saturated alkyl group having 4 to 20 carbon atoms and a ratio of carbon atoms to hydrogen atoms of 0.58 or more include isobornyl, bornyl, phensil (all of which are C ₁₀ H ₁₇ , Bridge carbonization such as 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) 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 (8). .

  Examples of the (meth) acrylic acid ester represented by the general formula (8) 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. Examples of the (meth) acrylate having an adamantyl group include 2-methyl-2-adamantyl (meth) acrylate and 2-ethyl-2-adamantyl (meth) Acrylate, 3-hydroxy-1-adamantyl (meth) acrylate, 1-adamantyl-α-trifluoromethyl (meth) acrylate Can be exemplified Relate like.

  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.

  In addition, when the fluorine-containing polymer of this invention is obtained using the monomer containing an alkoxysilane group as a monomer component, the usage-amount of the monomer is with respect to 100 weight part of phosphate ester (b-1). Thus, the amount is preferably about 1 to 100 parts by weight, and more preferably about 50 to 90 parts by weight. When a phosphoric acid group is imparted to the fluorine-containing polymer as in the present invention, adhesion to the metal substrate can be improved more effectively than when an alkoxysilane group is similarly introduced. Furthermore, unlike an alkoxysilane group, a phosphoric acid group is not easily subjected to hydrolysis. On the above fluoropolymer, the ratio of alkoxysilane groups to phosphate groups is relatively low. Such a fluorine-containing polymer has a tendency to be more excellent in adhesion to a metal substrate and more excellent in storage stability than a polymer having a higher proportion of alkoxysilane groups.

  The other monomer may be any monomer that can be copolymerized with the fluorinated acrylate ester, and can be selected over a wide range as long as the performance of the obtained fluorinated polymer is not adversely affected. For example, aromatic alkenyl compound, vinyl cyanide compound, conjugated diene compound, halogen-containing unsaturated compound, silicon-containing unsaturated compound, unsaturated dicarboxylic acid compound, vinyl ester compound, allyl ester compound, unsaturated group-containing ether compound, maleimide 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.

  However, it is preferable to use a mixed solvent with alcohol from the viewpoint of solubility of the phosphate ester (b-1). The alcohol used in this case is not particularly limited, but is highly compatible with the fluorine-based solvent to be used, has good compatibility with the phosphoric acid ester (b-1), and is based on the produced polymer. Those that are relatively soluble are preferred. Examples include isopropyl alcohol and ethanol. The mixing ratio is not particularly limited, but usually the range in which the weight ratio is fluorinated solvent: alcohol = 9.5: 0.5 to 7.5: 2.5, more preferably 9: 1 to 8: 2. May be set as appropriate.

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), particularly HCFC] 225 (dichloropentafluoropropane) (AK-225 (manufactured by Asahi Glass Co., Ltd.)), HCFC141b (dichlorofluoroethane), CFC316 (2, 2,3,3-tetrachlorohexafluorobutane), Vertrel XF (chemical formula C ₅ H ₂ F ₁₀ ) (manufactured by DuPont), AC-6000 (chemical name tridecafluorooctane) (manufactured by Asahi Glass), 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, the following general formula (9)

[Wherein, n is a number from 1 to 6, and X is a number from 1 to 6. ]
The compound shown by these is preferable. Such hydrofluoroethers include, for example, Novec HFE7100 (chemical formula C ₄ F ₉ OCH ₃ ) (boiling point 61 ° C.), 7200 (chemical formula C ₄ F ₉ OC ₂ H ₅ ) (boiling point 76 ° C.), manufactured by 3M USA, 7300 (chemical formula C ₆ F ₁₃ OCH ₃ ) (boiling point 98 ° C.) or the like can be used. HFE7100 may be used when quick drying is required, and HFE7300 may be used to control the volatility of the solvent when brushing a high-concentration polymer coating agent. HFE7200 has moderate volatility and can be used for most general purposes.

  In the present invention, in particular, in general formula (1), Rf is based on a fluoroalkyl group-containing α-substituted acrylate ester having a linear or branched fluoroalkyl group having 4 to 6 carbon atoms and a high softening point monomer. A coating composition in which a fluoropolymer obtained by using a polymer having a structural unit as an essential monomer component is dissolved in hydrofluoroether is preferred. Such a fluorine-containing polymer has good solubility in hydrofluoroether, and the formed film is a film having excellent waterproofness and moisture resistance, and is also a suitable material from the viewpoint of environmental compatibility. It is.

  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.

  A fluorine-type solvent can be used individually by 1 type or in mixture of 2 or more types.

  When radically polymerizing the fluorinated acrylate ester (a) in a fluorinated solvent, for example, dissolving the fluorinated acrylate ester in a solvent and adding a polymerization initiator while stirring the resulting solution. Allows the polymerization reaction to proceed.

  As the polymerization initiator, any known polymerization initiator for radical polymerization can be used without particular limitation. 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 is usually preferably about 0.01 to 10 parts by weight with respect to 100 parts by weight of the fluorine-containing acrylic ester (a) used as the monomer component. More preferably, it is about 0.1 to 1 part by weight.

  The concentration of the fluorinated acrylic ester (a) in the fluorinated 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 polymerization temperature and polymerization time may be appropriately adjusted according to the type of monomer component, the amount used, the type of polymerization initiator, the amount used, etc. The polymerization reaction may be performed at a temperature for 4 to 10 hours.

  The weight average molecular weight of the fluoropolymer obtained by the above 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 was determined by GPC (gel permeation chromatography) using a mixed solvent of HCFC225 (AK-225 (manufactured by Asahi Glass Co.)) / Hexafluoroisopropanol (= 90/10 weight) as an elution solvent. (Standard polymethylmethacrylate conversion).

  The fluorine-containing polymer obtained by the above-described method is a copolymer having structural units based on the fluorine-containing acrylic ester (a) and the phosphate ester (b-1). When a high softening point monomer is used, a structural unit based on the high softening point monomer is included.

  Among these, for example, the copolymer obtained using the (meth) acrylic acid ester represented by the above formula (8) as a high softening point monomer has a structure represented by the following general formula (4). It becomes the copolymer which has a part. According to this copolymer, it is possible to form a film having excellent durability, good waterproof and moistureproof performance, excellent water repellency, and good water drainage.

In the general formula (4), 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; 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 1 to 1 carbon atoms. 20 straight-chain or branched alkyl groups. Y is a direct bond, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, a —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (where R ¹ is the number of carbon atoms; 1 to 4 alkyl groups), —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 or a fluoropolyether group having a molecular weight of 400 to 10,000. R ^{2 ′} is a trivalent group derived from a group containing a radical polymerizable unsaturated bond, and when there are a plurality of R ^{2 ′} , each may be the same or different. R ⁵ is H or CH ₃ , and R ⁶ 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. j, k, and m are each an integer of 1 or more, l is 0 or an integer of 1 or more, and the sum of j, k, l, and m is a numerical value with a weight average molecular weight of 3,000 to 500,000. It is. Note that the order of existence of each repeating unit with parentheses attached with j, k, l, and m is arbitrary in the formula.

  In the above, the hydrocarbon group may be cyclic or non-cyclic, and may be either linear or branched.

  An example of the fluorine-containing polymer of the present invention is a polymer represented by the following general formula (5).

(Wherein j, k and m are each an integer of 1 or more, l is 0 or an integer of 1 or more, and the sum of j, k, l and m has a weight average molecular weight of 3,000 to 500, 000. It should be noted that the order of existence of each repeating unit in parentheses with j, k, l, and m attached is arbitrary in the formula.) In the present invention, a monomer having a hydroxyl group in the molecule [for example, 2-hydroxyethyl (meth) acrylate] is copolymerized with a fluorine-containing monomer, and then, orthophosphoric acid, polyphosphoric acid or quinolone is added to the hydroxyl group in the polymer. A phosphorylating agent such as phosphorus oxide may be reacted to introduce a phosphate ester moiety into the polymer.

Coating composition The coating composition of the present invention is obtained by dissolving the fluorine-containing polymer obtained by the above-described method in a fluorine-based solvent.

  The fluorine-containing polymer obtained by the above-described method has a good water repellency by containing a fluoroalkyl group or a fluoropolyether group, and a film formed from the polymer shows a good waterproof performance.

  Furthermore, the fluorine-containing polymer of the present invention has good adhesion to various metal substrates, particularly aluminum, due to the phosphoric acid group present in the side chain, and the formed film is durable and waterproof. The moisture proof performance is good.

  Therefore, the coating composition of the present invention can be used in applications where various durability such as solvent immersion, immersion in water, wiping, abrasion, high temperature and high humidity, and waterproof and moisture resistance are required.

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

  In the 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 be obtained.

  The fluorinated solvent used is the same as the fluorinated solvent used in the polymerization solvent described in (iii) the method for producing a fluorinated polymer.

  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 an electronic component connector or the like, the solid content concentration is 0.2 to 10% by weight, preferably 0.2 to 5% by weight, more preferably about 0.2 to 2% by weight. By doing so, a film having good abrasion resistance and excellent waterproof and moisture-proof performance can be formed without impeding electrical conductivity.

  The coating composition of the present invention may be used as it is as a coating composition after performing a radical polymerization reaction in a fluorine-based solvent according to the above-described method, and after adjusting the concentration of the polymer, if necessary. Alternatively, 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 main solvent, if necessary, by adjusting the polymer concentration using hydrofluoroether to obtain a coating composition, it is efficient. A desired coating composition can be obtained.

  The coating composition of the present invention may further contain a compound having a perfluoropolyether (PFPE) skeleton (hereinafter sometimes referred to as “PFPE compound”) as necessary. By blending the PFPE compound, the PFPE compound serves as a lubricant, and the slip resistance of the film formed from the fluoropolymer is improved, so that the wear resistance is greatly improved.

  In the present invention, specific examples of the PFPE compound include International Publication No. 97/07155, Japanese Translation of PCT International Application No. 2008-534696, International Publication No. 2013/146110, Japanese Unexamined Patent Application Publication No. 2010-217915, Japanese Unexamined Patent Application Publication No. 2013-2013. JP1117012, JP2002-348370, JP2012-72272, JP2003-238777, JP2000-143991, WO2013 / 121984, WO2013 / 121985 No., International Publication No. 2013/121986, International Publication No. 2014/069592 and the like. Moreover, as a PFPE compound, you may utilize what can be used as a surface treating agent. As commercially available surface treatment agents, KY-130 (manufactured by Shin-Etsu Chemical Co., Ltd.), KY-164 (manufactured by Shin-Etsu Chemical Co., Ltd.), KY-178 (manufactured by Shin-Etsu Chemical Co., Ltd.), KY-185 (manufactured by Shin-Etsu Chemical Co., Ltd.) ), OPTOOL DSX (manufactured by Daikin Industries), OPTOOL AES-4E (manufactured by Daikin Industries), and DC2634 (manufactured by Dow Corning).

  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.

  There is no particular limitation on the application target of the coating composition of the present invention, and various durability such as solvent immersion, immersion in water, wiping, abrasion, and high temperature and high humidity are applied to various substrates such as plastic, metal, ceramics and the like. A film having good and excellent waterproof and moisture-proof performance can be formed. In particular, when electronic components including connectors, housings, printed boards, semiconductors, etc. are to be processed, the use of the coating composition of the present invention makes it possible to use a solvent having low chemical erodibility and durability. Therefore, it is possible to provide good waterproof and moisture-proof performance without impairing the performance of the electronic component.

  There is no particular limitation on the treatment method using the coating composition of the present invention, and the coating composition of the present invention may be brought into contact with the object to be treated. Usually, what is necessary is just to dry in air | atmosphere of about 20-70% or more of humidity, after immersing a to-be-processed object in the coating composition of this invention. 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 dispenser can also be applied.

  There is no particular limitation on the temperature during the treatment, and usually the treatment may be performed at room temperature. The treatment time is not particularly limited, but, 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 durability, prior to the treatment with the coating composition of the present invention, the substrate is removed from the substrate with acetone, isopropyl alcohol (IPA), hydro- It is preferable to dry after washing with a solvent such as fluoroether or a mixed solvent thereof. In addition to the above cleaning, an oxide film formed on the metal surface by chemical cleaning such as acid (hydrochloric acid, nitric acid, hydrogen fluoride, etc.), UV ozone, etc., sandblasting, glass beads, plasma, etc. Removal is also useful for improving durability.

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

Production Example 1 Rf (C6) methacrylate / iBMA / PPME = 100 / 14.27 / 1.17 (weight ratio) In a polymer branch test tube, C ₆ F ₁₃ CH ₂ CH ₂ OCOC (CH ₃ ) ═CH ₂ (Hereafter, Rf (C6)
Methacrylate) 18.52 g, isobornyl methacrylate (hereinafter sometimes abbreviated as iBMA) 2.720 g, methacryloyloxyethyl phosphate (manufactured by Toho Chemical Industry, hereinafter abbreviated as PPME) 0.2209 g, and 80 g of perfluorobutyl ethyl ether (C ₄ F ₉ OC ₂ H ₅ : hereinafter abbreviated as “HFE7200”) / IPA (= 9/1 weight ratio) mixed solvent was charged, and nitrogen purged for 10 minutes. Heated to ° C. To this was added 0.1161 g of AIBN and reacted for 6 hours. It was confirmed by measurement by ³¹ P-NMR that the monoester (b-1) and diester (b-2) contents in PPME were 67 and 33 mol%, respectively.

  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 to calculate the resin solid content 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 eluent, fluorine-based solvent [HCFC225 (AK-225 (Asahi Glass Co., Ltd.); the same shall apply hereinafter) / hexafluoroisopropanol = 90/10 (weight) As eluent, fluorine-based solvent [HCFC225 / hexafluoroisopropanol = 90/10 ( The weight average molecular weight was 116,000 as a result of measuring the molecular weight by GPC using (Weight)].

Production Example 2 Rf (C6) methacrylate / iBMA / PPME = 100 / 14.27 / 2.34 (weight ratio) The fluoropolymer was prepared in the same manner as in Production Example 1 except that the amount of the polymer PRME was replaced with 0.4228 g. The resin solid content concentration of the synthesized and polymerized polymer was calculated. Then, the solution of the predetermined density | concentration used in the Example mentioned later was prepared by diluting the solution which calculated resin solid content density | concentration with HFE7200. The weight average molecular weight of the obtained polymer was 113,800.

Production Example 3 (Rf (C6) methacrylate / iBMA / AAEM = 100 / 14.62 / 2.34 (weight ratio) Polymer Rf (C6) methacrylate 3.920 g, iBMA 0.571 g, AAEM 0.09300 g The fluorine-containing polymer was synthesized by the same method as in Production Example 1, and the resin solid content concentration of the polymer after polymerization was calculated, and then the solution in which the resin solid content concentration was calculated was diluted with HFE7200, in the examples described later. A solution having a predetermined concentration to be used was prepared, and the weight average molecular weight of the obtained polymer was 113,000.

Production Example 4 (Rf (C6) methacrylate / iBMA / PPME / AAEM = 100 / 9.71 / 2.29 / 2.29 (weight ratio) Polymer Rf (C6) methacrylate 9.625 g, iBMA 0.9350 g, PPME 0 .2200 g and AAEM 0.2200 g were used to synthesize a fluorine-containing polymer by the same method as in Production Example 1, and the resin solid content concentration of the polymer after polymerization was calculated. A solution having a predetermined concentration used in Examples described later was prepared by diluting with 1. The weight average molecular weight of the obtained polymer was 114,000.

Reference Production Example 1 Rf (C6) methacrylate / iBMA / PPME = 100 / 14.49 / 0 (weight ratio) The polymer PPME content was set to zero, and the polymerization solvent was replaced with HFE7200 alone. A fluoropolymer was synthesized, and the resin solid content concentration of the polymer after polymerization was calculated. Then, the solution of the predetermined density | concentration used in the Example mentioned later was prepared by diluting the solution which calculated resin solid content density | concentration with HFE7200. The weight average molecular weight of the obtained polymer was 115,000.

Reference Production Example 2 Rf (C6) methacrylate / iBMA / TMSMA = 100 / 14.49 / 2.373 (weight ratio) The polymer PPME is abbreviated as 3- (trimethoxysilyl) propyl methacrylate (hereinafter, “TMSMA”). In addition, a fluorine-containing polymer was synthesized in the same manner as in Production Example 1 except that the polymerization solvent was replaced with the HFE7200 / IPA (= 9/1 weight ratio) mixed solvent by HFE7200 alone, and the polymer resin after polymerization was synthesized. The solid content concentration was calculated.
Then, the solution of the predetermined density | concentration used in the Example mentioned later was adjusted by diluting the solution which computed resin solid content density | concentration with HFE7200. The weight average molecular weight of the obtained polymer was 118,800.

Examples 1-4 and Reference Examples 1-4
Using silicon (Si), Al, Cu, or SUS304 (Fe / Ni / Cr alloy) test piece as the object to be processed, ultrasonic cleaning is performed in acetone for 30 minutes, and then immersed in HFE7200, followed by drying. The pretreatment was performed.

  The object to be treated pretreated by the above-described method is immersed in the HFE7200 solution (resin solid content concentration of 0.5% by weight) of each fluoropolymer obtained in Production Examples 1 and 2 and Reference Production Examples 1 and 2. After that, the test piece was produced by leaving it in the atmosphere (20 ° C., humidity 30%) for a whole day and night.

  As a result of measuring the initial value of the contact angle with respect to n-hexadecane (HD) for each of these test pieces, it was 62 to 65 °. Next, each test piece was immersed in a cleaning solvent HFE7200 alone or a mixed solvent of HFE7200 / IPA (9/1 weight ratio) at room temperature (25 ° C.), and irradiated with ultrasonic waves for 2 hours with an ultrasonic cleaner. After replacing the cleaning solvent with a new one, ultrasonic waves were irradiated for another 2 hours. Moreover, in order to avoid that the water temperature of an ultrasonic cleaner was raised, the water of the ultrasonic cleaner was changed to room temperature water every 1 hour. Then, it pulled up in air | atmosphere, left to stand for 1 minute, and the immersion durability with respect to the washing | cleaning solvent was evaluated by measuring a HD contact angle. The experiment was performed three times. FIG. 1 and Table 1 (cleaning solvent HFE7200 single cleaning) and FIG. 2 and Table 2 (cleaning solvent HFE7200 / IPA (= 9/1 weight) Ratio) cleaning). These results indicate that the closer the HD contact angle after ultrasonic cleaning is to the initial value, the more the fluoropolymer film remains on the metal substrate. The contact angle with respect to HD of various metal substrates before treatment with the fluoropolymer was 5 ° or less.

  As is apparent from the above results, Production Examples 1 and 2 were prepared by dissolving a fluoropolymer obtained by copolymerizing a fluoroalkyl group-containing acrylic ester, isobornyl methacrylate, and methacryloyloxyethyl phosphate in hydrofluoroether. It was found that this coating agent can form a film excellent in solvent immersion durability against aluminum and SUS304. The above results indicate that the phosphate groups introduced into the fluoropolymers of Production Examples 1 and 2 have specific adhesion to aluminum and SUS304. On the other hand, the methoxy group introduced into the fluorine-containing polymer of Reference Production Example 2 has a specific adhesion to the natural oxide film on the silicon base. The coating agent of Production Example 3 in which a fluoropolymer obtained by copolymerization of a fluoroalkyl group-containing acrylic ester, isobornyl methacrylate, and acetoacetoxymethyl methacrylate was dissolved in hydrofluoroether was produced in Reference Production Examples 1 and 2. It became clear that it showed adhesiveness to a copper substrate compared with. In addition, the coating agent of Production Example 4 was prepared by dissolving a fluoropolymer obtained by copolymerizing a fluoroalkyl group-containing acrylic ester, isobornyl methacrylate, methacryloyloxyethyl phosphate, and acetoacetoxymethyl methacrylate in hydrofluoroether. It was found that adhesion was exhibited not only on aluminum and SUS304 but also on a silicon substrate and a copper substrate (Example 6).

  After storing the HFE7200 solution (resin solid concentration 0.5 wt%) of each fluoropolymer obtained in Production Examples 1 and 2 and Reference Production Example 2 at 50 ° C. for 3 months, the washing solvent HFE7200 / IPA (= 9 / 1 weight ratio), a solvent immersion durability test was conducted. As a result, although the contact angles with respect to the aluminum of Production Examples 1 and 2 and SUS304 were hardly changed, the contact angle with respect to the silicon base of Reference Production Example 2 was about 60 ° before storage at 50 ° C. On the other hand, it decreased to about 40 ° after storage. From the above results, it was suggested that the storage stability of phosphate groups in the coating agent was excellent.

Example 5 and Reference Examples 5-6
Using the HFE7200 solution of each fluoropolymer obtained in Production Example 2 and the HFE7200 solution of each fluoropolymer obtained in Reference Production Examples 1 and 2, the moisture resistance and rust prevention properties were evaluated by the following methods. . The results are shown in Table 3.

* 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 circular shape (diameter 70 mm) was used as a support sheet, and a 5 wt% HFE7200 solution of each fluoropolymer was 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 C1100P buffing process, a copper substrate having a size of 2.0 × 15 × 60 mm (manufactured by Nippon Test Panel Industry) was used, and a film was formed by being immersed once in a 2% HFE7200 solution of each fluoropolymer. (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 apparent from the above results, it was found that the coating agent obtained in Production Example 2 can form a film having better moisture resistance and rust prevention than the coating agents obtained in Reference Production Examples 1 and 2.

  Although the reason why the moisture resistance is good is not clear, the contribution is that the phosphate ester compound (b-2) having two polymerization points forms a crosslinked structure in the polymer molecule. It is estimated that

Examples 6-12 and Comparative Examples 7-13
After charging a commercially available smartphone (Galaxy S (registered trademark) II manufactured by Samsung Electronics), the power was turned off, and the smartphone was set up vertically so that the micro USB portion was facing upward. The coating agent of Production Example 2 adjusted to various concentrations (0.1, 0.2, 0.5, 1, 2, 5, 10% by weight) inside the plug fitting port of the micro USB receptacle, or Reference Production Example After filling the coating agent of No. 2 with a dropper, immediately the smartphone was rotated so that the opening of the micro USB faced downward, and the coating agent was discharged, thereby coating the inside of the plug fitting opening. After the treatment, the sample was left for 1 hour in an environment at a temperature of 25 ° C. and a humidity of 60%, and then the following test was 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, there is electrical conductivity (◯), and when even 1 pole is 50 mΩ or more, the electrical conductivity is poor (×). Next, stand vertically so that the micro USB is facing upward, fill the inside of the plug fitting port with a dropper, 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 of about 110 °)
○: Play well (contact angle of about 100 °)
Δ: Play (contact angle of about 90 °)
×: (Contact angle of about 50-80 °)
XX: (Contact angle 50 ° or less)

-Insertion / removal test The contact resistance was measured after inserting and removing a plug 10,000 times into a waterproof micro USB. Next, water repellency was evaluated in the same manner as in the initial stage. Next, the power of the smartphone was turned on, and the smartphone was set up vertically so that the micro USB faced upward. After filling tap water into the plug fitting opening with a dropper, the water was left for 10 minutes. Tap water was discharged by turning the micro USB downward and dropping it on 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 (magnification 30 times) in the following five stages.
A: No discoloration ○: Slight discoloration Δ: Slight discoloration ×: Discoloration ××: Severe discoloration The above test results are shown in Table 4 below.

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

Claims (23)

(I) a fluorine-containing polymer,
(A) a fluorine-containing acrylic ester having a fluoroalkyl group or a fluoropolyether group ester-bonded to a carboxyl group directly or via a divalent organic group and having a substituent at the α-position;
And (b-1) a phosphate ester having one or more radically polymerizable groups in the molecule, and / or (b-2) a acetoacetoxyester having one or more radically polymerizable groups in the molecule. A coating composition comprising a fluorine-containing polymer that is a copolymer obtained by radical polymerization of a monomer component and (II) a fluorine-based solvent ,
When the monomer component includes (b-1) and does not include (b-2), the object to be processed is aluminum, SUS, or silicon.
When the monomer component contains (b-2) and does not contain (b-1), the object to be treated is copper,
When the monomer component includes (b-1) and (b-2), the coating composition is an object to be processed which is aluminum, SUS, silicon, or copper . The fluorine-containing acrylic ester (a) 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, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom, a —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (provided that , 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 — (CH ₂ ) _n SO ₂ — group (n is 1 to 10), and Rf is a straight chain having 1 to 20 carbon atoms. Or a branched fluoroalkyl group, or a fluoropolyether group having a molecular weight of 400 to 5,000.) The coating composition according to claim 1. The fluorine-containing acrylic ester (a) is represented by the general formula (1), wherein Rf is a linear or branched fluoroalkyl group having 4 to 6 carbon atoms, and X is an atom or group other than hydrogen. The coating composition according to claim 2, wherein the position is a substituted carboxylic acid ester. The fluorine-containing polymer is further used as a monomer component.
(C) Coating composition in any one of Claims 1-3 which is a copolymer obtained using a high softening point monomer. The fluorine-containing polymer is a copolymer obtained by using at least one compound represented by the following general formula (2) as the phosphate ester (b-1), according to any one of claims 1 to 4. Coating composition
(In the formula, R ² is a group containing a radically polymerizable unsaturated bond, and when there are plural groups, each may be the same or different, and n is 0, 1 or 2. .) The fluorine-containing polymer is a phosphoric ester (b-1), a compound (b-1-1) represented by the formula (2) where n = 2 and a compound represented by the formula (2) where n = 1 ( The coating composition according to claim 5, which is a copolymer obtained by using a mixture containing each of b-1-2). A mixture in which the fluorine-containing polymer contains 40 mol% to 95 mol% of the compound (b-1-1) and 5 mol% to 60 mol% of the compound (b-1-2) as the phosphate ester (b-1) is used. The coating composition according to claim 6, which is a copolymer obtained in the above manner. The fluorine-containing polymer is a copolymer obtained by using, as the phosphate ester (b-1), a compound represented by at least the above general formula (2), wherein R ² is a methacryloyloxyalkyl group. The coating composition according to claim 5 or 6. The fluorine-containing polymer is a copolymer obtained by using at least one compound represented by the following general formula (3) as the acetoacetoxy ester (b-2), according to any one of claims 1 to 8. Coating composition
(In the formula, Z is a direct bond, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom, a —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (where R ¹ is carbon Or 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 —. A group (n is 1 to 10),
R ³ is have an oxygen atom and a hydrocarbon group which may having 1 to 10 carbon atoms, and R ⁴ is a group containing a radical-polymerizable unsaturated bond. ). The coating composition according to any one of claims 4 to 9, 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. The coating composition according to any one of claims 1 to 10, wherein the fluoropolymer has a crosslinked structure. The fluorine-containing polymer has the following general formula (4):
(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, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur 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 -} .Rf 1 carbon atoms which is (n 1 to 10) Linear or branched fluoroalkyl group having 20 or a fluoropolyether group having a molecular weight of 400 to 5,000 .R 2 ^'is trivalent group derived from a group containing a radical-polymerizable unsaturated bond In the case where a plurality of them are present, they may be the same or different, and R ⁵ is H or CH ₃ , and R ⁶ is a carbon atom having 4 to 20 carbon atoms with respect to a hydrogen atom. A group having a saturated alkyl group with a ratio of 0.58 or more, j, k and m are each an integer of 1 or more, l is 0 or an integer of 1 or more, and j, k, l and m are the sum Is a numerical value with a weight average molecular weight of 3,000 to 500,000, where j, k, l, and m are attached and parenthesized parentheses are present in any order in the formula. Having a structural part represented by In it, the coating composition of claim 1. The fluorine-containing polymer has the following general formula (5):
(Wherein j, k and m are each an integer of 1 or more, l is 0 or an integer of 1 or more, and the sum of j, k, l and m has a weight average molecular weight of 3,000 to 500, 000. It should be noted that the order of existence of each repeating unit in parentheses with j, k, l, and m attached is arbitrary in the formula.) The coating composition of claim 1, wherein 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. And Y and Z are the same or different and each represents a direct bond, a hydrocarbon group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, —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 — (CH ₂ ) _n SO ₂ — group (where n is 1 to 1). Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, or a fluoropolyether group having a molecular weight of 400 to 5,000, and R ^{2 ′} represents a radical polymerizable unsaturated bond. And a trivalent group derived from the containing group, and when there are a plurality of groups, each may be the same or different, and R ³ may have an oxygen atom. R ^{4 ′} is a group containing a radically polymerizable unsaturated bond, R ⁵ is H or CH ₃ , and R ⁶ is a carbon atom having 4 to 20 carbon atoms with respect to a hydrogen atom. A group having a saturated alkyl group having a carbon atom ratio of 0.58 or more, j, m and n are each an integer of 1 or more, k and l are 0 or an integer of 1 or more, and j, k, l , M and n have a weight average molecular weight of 3,000 to 500,000. Note that the order of existence of each repeating unit in parentheses with j, k, l, m, and n attached thereto is arbitrary in the formula.) The coating composition according to claim 1, wherein The fluorine-containing polymer has the following general formula (7):
(Wherein j, m and n are each an integer of 1 or more, k and l are 0 or an integer of 1 or more, and the sum of j, k, l, m and n has a weight average molecular weight of 3,000. It is a numerical value of ˜500,000, where the order of presence of each repeating unit in parentheses with j, k, l, m and n attached thereto is arbitrary in the formula. The coating composition according to claim 1, which has a structural portion. The coating composition according to claim 1, wherein the fluorine-based solvent is hydrofluoroether. Furthermore, the coating composition in any one of Claims 1-16 containing the compound which has a perfluoro polyether skeleton. The coating composition according to claim 17, 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. The coating composition for connectors of electronic components according to any one of claims 1 to 18, wherein the solid content concentration is 0.2 to 10% by weight. The coating composition according to claim 1, wherein the workpiece is an electronic component. A method for forming a film, comprising the step of bringing an object to be treated into contact with the coating composition according to claim 1 ,
When the monomer component includes (b-1) and does not include (b-2), the object to be processed is aluminum, SUS, or silicon.
When the monomer component contains (b-2) and does not contain (b-1), the object to be treated is copper,
The method for forming a film, wherein when the monomer component includes (b-1) and (b-2), the object to be processed is aluminum, SUS, silicon, or copper . The method for forming a film according to claim 21, wherein the object to be processed is an electronic component. A connector for an electronic component having a film formed by the coating composition according to claim 1 ,
When the monomer component contains (b-1) and does not contain (b-2), the surface on which the film is formed is aluminum, SUS or silicon,
When the monomer component contains (b-2) and does not contain (b-1), the surface on which the film is formed is copper,
The method for forming a film, wherein when the monomer component includes (b-1) and (b-2), the surface on which the film is formed is aluminum, SUS, silicon, or copper .