JP5593698B2 - Water-based coating agent for electronic parts - Google Patents

Description

  The present invention relates to an aqueous coating agent that imparts excellent moisture resistance, water / oil repellency and antifouling properties to electronic parts and electrical parts. In the present invention, the term “electronic component” means both an electronic component and an electrical component.

  For control of outdoor electronic / electrical devices (for example, telephones, traffic lights, air conditioner outdoor units, switchboards, pole capacitors, mobile phones, portable relay antennas, automotive electronic devices, ship electronic devices, vending machines, mobile PCs, etc.) In addition, electronic / electrical circuit boards are being attached. In this case, there are cases where the metal wiring is corroded by acid or salt caused by rain, moisture, dust, insects, etc., and the circuit may be destroyed. Therefore, in recent years, it is a common practice to increase the moisture resistance by applying a coating to the surface of a circuit board after mounting electronic / electrical components.

  In order to form a moisture-proof coating, a method of applying a water / oil repellent is known.

  The water and oil repellent is applied by dissolving low molecular weight silicone and fluorine compounds (perfluoropolyether oligomers, etc.) with poor film-forming ability in a solvent and spraying the circuit board (patent) Therefore, no coating is formed on the surface of the circuit board, and the effect of the coating decreases with time.

  Patent Document 2 (Japanese Patent Laid-Open No. 61-189893) discloses that a coating solution in which a polyfluoroalkyl group-containing polymer is dissolved in a nonflammable low-boiling organic solvent is applied to an electronic component. . However, the organic solvent has a problem from the viewpoint of the coating operation and the environment.

Next, I will explain the environmental problems of PFOA. From recent research results [EPA report "PRELIMINARY RISK ASSESSMENT OF THE DEVELOPMENTAL TOXICITY ASSOCIATED WITH EXPOSURE TO PERFLUOROOCTANOIC ACID AND ITS SALTS" (http://www.epa.gov/opptintr/pfoa/pfoara.pdf)] Concerns about the environmental impact of PFOA (perfluorooctanoic acid), a type of fluoroalkyl compound, have become apparent, and on April 14, 2003, EPA (US Environmental Protection Agency) will strengthen scientific research on PFOA Announced.
Meanwhile, Federal Register (FR Vol.68, No.73 / April 16, 2003 [FRL-2303-8], http://www.epa.gov/opptintr/pfoa/pfoafr.pdf) and EPA Environmental News FOR RELEASE : MONDAY APRIL 14, 2003 EPA INTENSIFIES SCIENTIFIC INVESTIGATION OF A CHEMICAL PROCESSING AID (http://www.epa.gov/opptintr/pfoa/pfoaprs.pdf) and EPA OPPT FACT SHEET April 14, 2003 (http: // www. epa.gov/opptintr/pfoa/pfoafacts.pdf) publishes that telomers can produce PFOA by degradation or metabolism (telomers mean long chain fluoroalkyl groups). We also announced that telomers are used in many products such as foam, water- and oil-repellent and antifouling foams, care products, cleaning products, carpets, textiles, paper and leather. Yes.

  When the Rf group carbon number of the fluorine-containing copolymer mentioned above is 8 or more, there is a problem that it contains PFOA and PFOA analogs having bioaccumulative properties. There is a need for fluorine-containing polymers with improved transition to chain Rf group-containing fluoroacrylate polymers and improved compatibility with other materials and skin.

Japanese Patent No. 3122443 JP-A 61-189893

An object of the present invention is to provide a moisture-proof coating agent (that is, an aqueous coating composition) that is excellent in coating workability and environmental properties (no organic solvent is used).
Another object of the present invention is to provide a moisture-proof coating agent that can easily form a coating on the surface of an electronic component and can form a coating film that is excellent not only in moisture resistance but also in chemical resistance, electrical insulation, weather resistance, and durability. There is also to provide.

That is, this invention relates to the moisture-proof coating agent for electronic components which consists of a fluorine-containing compound (1) and an aqueous liquid medium (2).
The fluorine-containing compound (1) is generally a fluorine-containing polymer. The fluorine-containing compound (1) is
(A) A polymer having a repeating unit derived from a fluorine-containing acrylate monomer is preferred. The fluorine-containing compound (1) is
A polymer having (A) a repeating unit derived from a fluorine-containing acrylate monomer and (B) a repeating unit derived from an amino group-containing monomer is particularly preferred.

In the present invention, the fluoropolymer has sufficient solubility in the necessary water. When it has a short-chain fluoroalkyl group having 7 or less carbon atoms, especially 6 or less, higher solubility can be obtained. The fluorine-containing polymer of the present invention has sufficiently high water solubility, and gives high moisture resistance on the substrate.
The coating agent of the present invention can be easily formed on the surface of an electronic component by drying at a low temperature in a short time. The coating has excellent moisture resistance, water / oil repellency and antifouling properties, and is excellent in sustainability of these properties. The film formed from the coating agent of the present invention has high moisture resistance, water / oil repellency and antifouling property even if the film thickness is thin. Furthermore, the coating is excellent in chemical resistance, electrical insulation, weather resistance, and durability.

In the present invention, the “acrylate monomer” includes not only an acrylate having a hydrogen atom at the α-position but also an acrylate in which the hydrogen atom at the α-position is substituted with a substituent such as a methyl group or a halogen atom. .
In the fluorine-containing polymer, examples of the fluorine-containing acrylate monomer (A) include at least one fluorine-containing group selected from the group consisting of a fluoroalkyl group, a fluoroalkenyl group and a fluoroether group (hereinafter referred to as “fluorine-containing group”). And the formula: —O—CO—CX═CH ₂
[Wherein, X represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a CFX ¹ X ² group (where X ¹ and X ² is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom or an iodine 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. ]
It is a monomer which has an unsaturated group represented by these.

Examples of the acrylate monomer having a fluorine-containing group include a formula:
CH ₂ = C (−X) −C (= O) −OY−Rf (I)
[Wherein, X represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a CFX ¹ X ² group (where X ¹ and X ² is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom or an iodine 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,
Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom, an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom, a cyclic aliphatic group or an aromatic group. An aliphatic group, a —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (where R ¹ is an alkyl group having 1 to 4 carbon atoms) or a —CH ₂ CH (OY ¹ ) CH ₂ — group ( Y ¹ is a hydrogen atom or an acetyl group.
Rf is a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, or fluoroalkenyl group having 2 to 7 carbon atoms, repeating _{units: -C 3 F 6 O -,} - C 2 F 4 O- and - The total number of at least one repeating unit selected from the group consisting of CF ₂ O— is a fluoroether group having 1 to 200. ]
Indicated by

In the formula (I), when the Rf group is a fluoroalkyl group, it is preferably a perfluoroalkyl group. Specific examples of Rf groups are those having 1 to 7 carbon atoms, _{e.g., -CF 3, -CF 2 CF 3} , -CF 2 CF 2 CF 3, -CF (CF 3) 2, -CF 2 CF 2 CF 2 CF ₃ , —CF ₂ CF (CF ₃ ) ₂ , —C (CF ₃ ) ₃ , — (CF ₂ ) ₄ CF ₃ , — (CF ₂ ) ₂ CF (CF ₃ ) ₂ , —CF ₂ C (CF ₃ ) ₃ , -CF (CF ₃ ) CF ₂ CF ₂ CF ₃ ,-(CF ₂ ) ₅ CF ₃ ,-(CF ₂ ) ₃ CF (CF ₃ ) ₂ ,-(CF ₂ ) ₄ CF (CF ₃ ) ₂ , — (CF ₂ ) ₂ H, —CF ₂ CFHCF ₃ , — (CF ₂ ) ₄ H, — (CF ₂ ) ₆ H, and the like. When the Rf group is a fluoroalkyl group, the number of carbon atoms of the Rf group is 1 to 7, for example 2 to 6, particularly 4 to 6, particularly 6 from the viewpoints of PFOA and functions described above. Is preferred.
When the Rf group is a fluoroalkenyl group, examples of the Rf group are -CF = CF (CF ₃ ), -CF = C (CF ₃ ) ₂ , -CF = C (CF ₃ ) (CF ₂ CF ₂ CF ₃ ). _{, -CF = C (CF 3)} (CF (CF 3) 2), - C (CF 3) = CF (CF (CF 3) 2), -C (CF 2 CF 3) = C (CF 3) 2 Etc. When the Rf group is a fluoroalkenyl group, the Rf group preferably has 2 to 7 carbon atoms, particularly 3 to 6 carbon atoms, especially 6 carbon atoms.

）、
アミン基（例えば、H₂N-）、カルボン酸基（例えば、HOOC-）、酸ハライド基（例えば、F(O=)C-）、クロロメチル基（ClH₂C-）である。フルオロエーテル基は、オキシパーフルオロアルキレン繰り返し単位および末端基に加えて、炭素数１〜１０のフルオロアルキレン基、特にパーフルオロアルキレン基を有していてもよい。炭素数１〜１０のフルオロアルキレン基の例は、-CF₂-および-CF₂CF₂-である。When the Rf group is a fluoroether group, the fluoroether group is at least one repeating unit selected from the group consisting of —C ₃ F ₆ O—, —C ₂ F ₄ O— and —CF ₂ O— (oxypar Fluoroalkylene group). -C ₃ F ₆ O- is -CF ₂ CF ₂ CF ₂ O- or -CF ₂ C (CF ₃₎ is fo-. -C ₂ F ₄ O- is generally _-CF 2 _CF 2 O- are. The total number of oxyperfluoroalkylene repeating units is 1 to 200, for example 1 to 100, in particular 5 to 50. The fluoroether group has a terminal group that is directly bonded to the oxyperfluoroalkylene repeat unit. Examples of the terminal group include a hydrogen atom, a halogen atom (for example, a fluorine atom), an alcohol group (for example, HOCH ₂ —), an epoxy group (for example,

),
An amine group (for example, H ₂ N-), a carboxylic acid group (for example, HOOC-), an acid halide group (for example, F (O =) C-), and a chloromethyl group (ClH ₂ C-). The fluoroether group may have a fluoroalkylene group having 1 to 10 carbon atoms, particularly a perfluoroalkylene group, in addition to the oxyperfluoroalkylene repeating unit and the terminal group. Examples of the fluoroalkylene group having 1 to 10 carbon atoms are —CF ₂ — and —CF ₂ CF ₂ —.

Examples of fluoroether groups (particularly perfluoroether groups) that are examples of Rf groups are as follows.
F- (CF ₂ CF ₂ CF ₂ O) _n -CF ₂ CF _2- (n is 1 to 200)
F- (CF ₂ C (CF ₃ ) FO) _n -CF ₂ CF _2- (n is 1 to 200)
F- (CF ₂ C (CF ₃ ) FO) _n- (CF ₂ O) _m -CF ₂ CF _2- (total of n and m is 1 to 200)
F- (CF ₂ CF ₂ O) _n- (CF ₂ O) _m -CF ₂ CF _2- (total of n and m is 1 to 200)

Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom, an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom, a cyclic aliphatic group or an aromatic group. An aliphatic group, a —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (where R ¹ is an alkyl group having 1 to 4 carbon atoms) or a —CH ₂ CH (OY ¹ ) CH ₂ — group ( However, Y < ¹ > is a hydrogen atom or an acetyl group.). The aliphatic group is preferably an alkylene group (particularly having 1 to 4 carbon atoms, such as 1 or 2). The aromatic group and the cycloaliphatic group may be either substituted or unsubstituted.

Examples of the fluorine-containing acrylate monomer are as follows.
Rf- (CH ₂ ) ₁₀ OCOCH═CH _{2
Rf- (CH 2) 10 OCOC (} CH 3) = CH 2
Rf—CH ₂ OCOCH═CH _{2
Rf-CH 2 OCOC (CH 3} ) = CH 2
Rf- (CH ₂ ) ₂ OCOCH═CH ₂
Rf- (CH ₂ ) ₂ OCOC (CH ₃ ) ═CH _{2
Rf-SO 2 N (CH 3} ) (CH 2) 2 OCOCH = CH 2
_{Rf-SO 2 N (C 2} H 5) (CH 2) 2 OCOCH = CH 2
_{Rf-CH 2 CH (OCOCH 3} ) CH 2 OCOC (CH 3) = CH 2
_{Rf-CH 2 CH (OH)} CH 2 OCOCH = CH 2

[Wherein, Rf is preferably a linear or branched fluoroalkyl group having 1 to 7 carbon atoms, a fluoroalkenyl group having 2 to 7 carbon atoms, or a repeating unit: —C ₃ F ₆ O—, — the total number of C ₂ F ₄ O-and at least one repeating unit of selected from the group consisting of _-CF 2 O-are fluoroether group 1-200. ]

［式中、Ｒ^１１、Ｒ^１２、Ｒ^２１は、同一又は異なって、水素原子、又は炭素数１〜４のアルキル基であり、Ｙ¹¹は酸素原子又はＮＨであり、Ｚは炭素数１〜１０の分岐または直鎖のアルキレン基である。Ｒ^１１とＲ^１２は互いに結合して隣接する窒素原子と共に環を形成してもよい。］
で示されるものである。
共重合体は、アミノ基を含むため、例えばプロトン酸により塩を形成すると、水に溶解したときに解離してカチオン性を呈する。The amino group-containing monomer (B) is a compound having an amino group and a carbon-carbon double bond. The amino group-containing monomer (B) preferably does not contain a fluorine atom.
Examples of amino group-containing monomers (B) have the formula:

[Wherein R ¹¹ , R ¹² and R ²¹ are the same or different and are a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, Y ¹¹ is an oxygen atom or NH, and Z is 1 to 1 carbon atom. 10 branched or straight chain alkylene groups. R ¹¹ and R ¹² may be bonded to each other to form a ring together with the adjacent nitrogen atom. ]
It is shown by.
Since the copolymer includes an amino group, for example, when a salt is formed with a protonic acid, the copolymer is dissociated when dissolved in water and becomes cationic.

R < ¹¹ >, R <^12> , R <^21> shows a hydrogen atom or a C1-C4 alkyl group (for example, methyl, ethyl, propyl, butyl etc.), respectively. R ²¹ is preferably a hydrogen atom or a methyl group. When R ¹¹ and R ¹² are bonded to each other to form a ring with an adjacent nitrogen atom, R ¹¹ and R ¹² may be bonded through a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom. Examples of the ring formed by combining R ¹¹ and R ¹² together with the adjacent nitrogen atom include an aziridine ring, a pyrrolidine ring, a piperidine ring, a piperazine ring, and a morpholine ring.
Examples of the alkylene group as Z include linear or branched alkylene groups having 1 to 6 carbon atoms (preferably having 1 to 4 carbon atoms) such as methylene, ethylene, propylene, trimethylene, tetramethylene and hexamethylene groups. Can be mentioned.

Specific examples of the amino group-containing monomer (B) include dimethylaminomethyl (meth) acrylate, diethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) ) A compound in which Y ¹¹ is an oxygen atom in chemical formula (II) such as acrylate and diethylaminopropyl (meth) acrylate; Y ¹¹ in chemical formula (II) such as dimethylaminoethyl (meth) acrylamide and dimethylaminopropyl (meth) acrylamide The compound etc. which are NH are mentioned. The amino group-containing monomer (B) can be used alone or in combination of two or more.

The monomer constituting the fluoropolymer may contain a hydrophilic non-fluorine monomer (C) in addition to the monomers (A) and (B). The hydrophilic non-fluorine monomer (C) has hydrophilicity and does not contain a fluorine atom.
An example of a hydrophilic group is an oxyalkylene group.

The hydrophilic non-fluorine monomer (C) may be a monomer having a hydrophilic group which is an oxyalkylene group (an alkylene group having 2 to 6 carbon atoms) and a carbon-carbon double bond.
The hydrophilic group which is an oxyalkylene group is nonionic. The number of oxyalkylene groups in the hydrophilic non-fluorine monomer (C) may be 2 to 200, for example 3 to 50.
The hydrophilic non-fluorine monomer (C) may be polyalkylene glycol mono (meth) acrylate and / or polyalkylene glycol di (meth) acrylate.
The molecular weight of the hydrophilic non-fluorine monomer (C) may be 100 or more, such as 150 or more, particularly 200 or more, particularly 250 to 3000.

The polyalkylene glycol mono (meth) acrylate has the general formula:
CH ₂ = CX ¹ C (= O) −O− (RO) _n −X ² (III)
[Where:
X ¹ is a hydrogen atom or a methyl group,
X ² is a hydrogen atom or an unsaturated or saturated hydrocarbon group having 1 to 22 carbon atoms, R is an alkylene group having 2 to 6 carbon atoms,
n is an integer of 2 to 90,
It is. ]
It is preferable that it is shown by these. n may in particular be 3-30, for example 4-20.

R in the general formula (III) is preferably ethylene, propylene and butylene, particularly an ethylene group.
R in the general formula (III) may be a combination of two or more alkylene groups. In that case, at least one of R is preferably an ethylene group. Examples of the combination of R include an ethylene group / propylene group combination and an ethylene group / butylene group combination.
The hydrophilic non-fluorine monomer (C) may be a mixture of two or more. In that case, at least one of the hydrophilic non-fluorine monomers (C) preferably has R in the general formula (III) as an ethylene group.

Specific examples of the hydrophilic non-fluorine monomer (C) include, for example, the following, but are not limited thereto.
CH ₂ = CX ¹ COO- (CH ₂ CH ₂ O) _n -H
CH ₂ = CX ^1- (CH ₂ CH ₂ O) _n -CH ₃
CH ₂ = CX ¹ COO- (CH ₂ CH (CH ₃ ) O) _n -H
CH ₂ = CX ¹ COO- (CH ₂ CH (CH ₃ ) O) _n -CH ₃
CH ₂ = CX ¹ COO- (CH ₂ CH ₂ O) _5- (CH ₂ CH (CH ₃ ) O) ₂ -H
CH ₂ = CX ¹ COO- (CH ₂ CH ₂ O) _5- (CH ₂ CH (CH ₃ ) O) ₃ -CH _{3
^{CH 2 = CX 1 COO- (CH}} 2 CH 2 O) 8 - (CH 2 CH (CH 3) O) 6 -CH 2 CH (C 2 H 5) C 4 H 9
CH ₂ = CX ¹ COO- (CH ₂ CH ₂ O) ₂₃ -OOC (CH ₃ ) C = CH _{2
^{CH 2 = CX 1 COO- (CH}} 2 CH 2 O) 20 - (CH 2 CH (CH 3) O) 5 -CH 2 -CH = CH 2

  In addition to the monomers (A), (B), and (C), the monomer constituting the fluoropolymer may contain another monomer (D) as necessary. The other monomer (D) is preferably a non-fluorine monomer. Examples of the other monomer (D) include hydrocarbon group-containing monomers, ethylene, vinyl acetate, vinyl halide (for example, vinyl chloride), vinylidene halide (for example, vinylidene chloride), acrylonitrile, 2- Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerol mono (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, vinyl alkyl ketone, vinyl alkyl Examples include, but are not limited to, ether, isoprene, chloroprene, butadiene and the like.

Another example of the other monomer (D) includes a monomer having a silane group. The monomer having a silane group is preferably a compound having a silane group (particularly a terminal silane group) and a carbon-carbon double bond. The monomer having a silane group may be a terminal silane coupling agent or a monomer having a silane coupling agent in the side chain.
Specific examples of the monomer having a silane group are as follows.
CH ₂ = CHCO ₂ (CH ₂ ) ₃ Si (OCH ₃ ) ₃ ,
CH ₂ = CHCO ₂ (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ ,
_{CH 2 = C (CH 3)} CO 2 (CH 2) 3 Si (OCH 3) 3
(Γ-methacryloxypropyltrimethoxysilane),
CH ₂ = C (CH ₃ ) CO ₂ (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ ,
_{CH 2 = CHCO 2 (CH 2} ) 3 SiCH 3 (OC 2 H 5) 2,
CH ₂ = C (CH ₃ ) CO ₂ (CH ₂ ) ₃ SiC ₂ H ₅ (OCH ₃ ) ₂ ,
_{CH 2 = C (CH 3)} CO 2 (CH 2) 3 Si (CH 3) 2 (OC 2 H 5),
_{CH 2 = C (CH 3)} CO 2 (CH 2) 3 Si (CH 3) 2 OH,
CH ₂ = CHCO ₂ (CH ₂ ) ₃ SiCH ₃ [ON (CH ₃ ) C ₂ H ₅ ] ₂ ,
CH ₂ = C (CH ₃ ) CO ₂ (CH ₂ ) ₃ SiC ₆ H ₅ [ON (CH ₃ ) C ₂ H ₅ ] ₂ ,
CH ₂ = CHSi (OCH ₃ ) ₃ ,
CH ₂ = CHSi (OC ₂ H ₅ ) ₃ ,
CH ₂ = CHSiCH ₃ (OCH ₃ ) ₂ ,
CH ₂ = CHSi (CH ₃ ) ₂ (OC ₂ H ₅ ),
CH ₂ = CHSi (CH ₃ ) ₂ SiCH ₃ (OCH ₃ ) ₂ ,
CH ₂ = CHSiCH ₃ [ON (CH ₃ ) C ₂ H ₅ ] ₂
Vinyltrichlorosilane,
Vinyltris (2-methoxyethoxy) silane.

The weight average molecular weight of the fluorine-containing polymer may be, for example, 1000 to 1000000, particularly 2000 to 100000, particularly 4000 to 20000. The weight average molecular weight of the fluoropolymer is determined by GPC (gel permeation chromatography) (polystyrene conversion).
The fluoropolymer is soluble in water. The solubility of the fluoropolymer (the amount of the fluoropolymer that can be dissolved in 100 g of water at 25 ° C.) may be 5 g or more, for example, 10 g or more, particularly 20 g or more. The upper limit of solubility may be 500 g, for example 200 g.

The fluorine-containing polymer may be composed of a combination of repeating units derived from the following monomers.
(1) Monomer (A) + Monomer (B)
(2) Monomer (A) + Monomer (B) + Monomer (C)
(3) Monomer (A) + Monomer (B) + Monomer (D)
(4) Monomer (A) + Monomer (B) + Monomer (C) + Monomer (D)

In the fluoropolymer, with respect to 100 parts by weight of the monomer (A),
The amount of monomer (B) is 1 to 500 parts by weight, for example 2 to 100 parts by weight, in particular 3 to 80 parts by weight, especially 5 to 70 parts by weight,
The amount of the monomer (C) is 0 to 10 parts by weight, for example 1 to 5 parts by weight,
The amount of monomer (D) is 0-10 parts by weight, for example 1-5 parts by weight,
It may be.

  The fluoropolymer in the present invention can be produced by any ordinary polymerization method, and the conditions for the polymerization reaction can be arbitrarily selected. Examples of such polymerization methods include solution polymerization, suspension polymerization, and emulsion polymerization. In particular, solution polymerization is preferable.

  In solution polymerization, a method in which a monomer is dissolved in an organic solvent in the presence of a polymerization initiator, and after nitrogen substitution, for example, is heated and stirred in the range of 50 to 120 ° C. for 1 to 10 hours. Examples of the polymerization initiator include azobisisobutyronitrile, azobisisovaleronitrile, benzoyl peroxide, di-t-butyl peroxide, lauryl peroxide, cumene hydroperoxide, t-butyl peroxypivalate, Examples include diisopropyl peroxydicarbonate. The polymerization initiator may be used in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the monomer.

  Organic solvents are those that are inert to the monomers and dissolve them, such as pentane, hexane, heptane, octane, isooctane, cyclohexane, benzene, toluene, xylene, petroleum ether, commercially available petroleum solvents (ExxonMobil). EXXSOL D40, ISOPER E, etc.), tetrahydrofuran, 1,4-dioxane, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, t-butyl acetate, isopropanol, propylene glycol methyl ether acetate, p- Examples include chlorobenzotrifluoride, 1,1,2,2-tetrachloroethane, 1,1,1-trichloroethane, trichloroethylene, perchloroethylene, tetrachlorodifluoroethane, trichlorotrifluoroethane, and the like. The organic solvent may be used in the range of 50 to 1000 parts by weight with respect to 100 parts by weight of the total amount of monomers.

  After the polymerization reaction, an aqueous solution of the polymer can be obtained by adding water to the reaction mixture and removing the organic solvent (such as by distillation).

In the present invention, the coating agent (for example, water / oil repellent or antifouling agent) comprises (1) a fluoropolymer and (2) an aqueous liquid medium, that is, water or a mixture of water and a water-soluble organic solvent. Comprising. Examples of water-soluble organic solvents are alcohols such as methanol, ethanol, n-propanol, isopropanol; ketones such as acetone. The amount of the water-soluble organic solvent may be 50% by weight or less, for example, 1 to 30% by weight with respect to the mixture (total of water and the water-soluble organic solvent).
The coating agent is in the form of a solution (aqueous solution) of a fluoropolymer.
In the coating agent, the amount of the fluorine-containing polymer is not particularly limited and may be appropriately selected from a range in which it can be uniformly dissolved. For example, it may be 0.1 to 50% by weight, for example 0.2 to 20% by weight, in particular 0.5 to 10% by weight, based on the coating agent.

The coating agent of the present invention may contain (3) an additive in addition to (1) the fluoropolymer and (2) the aqueous liquid medium.
Examples of the additive (3) are silicon-containing compounds.
The silicon-containing compound is preferably a compound having at least one siloxane bond. The silicon-containing compound is generally a compound excluding a monomer having a silane group.

[式中、R¹ⁿは炭素数1〜18のアルキル基を表し、nnが2以上の場合には同一であっても異なっていてもよい。 R²ⁿは、水素原子または炭素数1〜5のアルキル基を表し、nnが2以上の場合には同一であっても異なっていてもよい。nnは、1〜20の整数を表す。]
で示される化合物であってよい。Examples of silicon-containing compounds include alkyl silicates and siliconates.
Examples of alkyl silicates include the following general formula (I):

[Wherein, R ¹ⁿ represents an alkyl group having 1 to 18 carbon atoms, and when nn is 2 or more, they may be the same or different. R ²ⁿ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and may be the same or different when nn is 2 or more. nn represents an integer of 1 to 20. ]
It may be a compound shown by these.

With respect to R ¹ⁿ , the alkyl group having 1 to 18 carbon atoms (that is, a saturated chain aliphatic hydrocarbon group) is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. Group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, and the like. It may be branched or branched.

Regarding R ²ⁿ , the alkyl group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group, and these are linear. Alternatively, it may be branched.
The nn is an integer of 1 to 20, for example, 1 to 10.

  More specifically, the alkyl silicate includes, for example, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, heptyltrimethoxysilane, octyltrimethyl. Methoxysilane, nonyltrimethoxysilane, decyltrimethoxysilane, undecyltrimethoxysilane, dodecyltrimethoxysilane, tridecyltrimethoxysilane, tetradecyltrimethoxysilane, pentadecyltrimethoxysilane, hexadecyltrimethoxysilane, heptadecyl Trimethoxysilane, octadecyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltriethoxy Silane, pentyltriethoxysilane, hexyltriethoxysilane, heptyltriethoxysilane, octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, undecyltriethoxysilane, dodecyltriethoxysilane, tridecyltriethoxysilane, tetra Examples include decyltriethoxysilane, pentadecyltriethoxysilane, hexadecyltriethoxysilane, heptadecyltriethoxysilane, octadecyltriethoxysilane, and the like. Among them, methyltrimethoxysilane, methyltriethoxysilane, hexyltriethoxy Silane and octyltriethoxysilane are preferred.

  In addition, dimers or the like of silicon-containing compounds can also be used as silicon-containing compounds, and examples thereof include those having nn of 2 or 3 in the above general formula (I). Furthermore, nn may be an integer up to 20.

Siliconates (especially alkyl siliconates) are for example represented by the formula:
R ¹ _a Si (OR ² ) _b (OM) _c is a compound represented by _c .
[Wherein, a is an integer of 0 or more (preferably 1), b is an integer of 0 or more (preferably 2), c is an integer of 1 or more (preferably 1), and satisfies a + b + c = 4. R ¹ may be the same or different and represents a hydrocarbon group having 1 to 18 carbon atoms. R ² may be the same or different and represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. M may be the same or different and represents an alkali metal. ]

The hydrocarbon group is, for example, an aliphatic hydrocarbon group (for example, an alkyl group), an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or an araliphatic hydrocarbon group.
Examples of R ¹ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, t-pentyl group, and n-hexyl. Group, n-heptyl group, n-octyl group, isooctyl group, 2,2,4-trimethylpentyl group, n-nonyl group, n-decyl group, n-dodecyl group, n-octadecyl group, cyclopentyl group, cyclohexyl group , Cycloheptyl group, methylcyclohexyl group, phenyl group, naphthyl group, anthryl group, phenanthryl group, tolyl group, xylyl group, ethylphenyl group, benzyl group, phenylethyl group and the like. Among these, a methyl group, an ethyl group, and a propyl group are preferable, and a methyl group is particularly preferable.
Examples of R ² include a hydrogen atom and the same group as R ¹ . Among these, a hydrogen atom, a methyl group, and an ethyl group are preferable, and a hydrogen atom is particularly preferable.
Examples of M include Li, Na, K and the like, and Na is particularly preferable.
Specific examples of the alkyl siliconate are sodium methyl siliconate [CH ₃ Si (OH) ₂ (ONa)] and potassium ethyl siliconate [C ₂ H ₅ Si (OH) ₂ (OK)].

  The amount of the additive (3) may be 0 to 200 parts by weight, for example 0 to 50 parts by weight, for example 0.1 to 50 parts by weight with respect to 100 parts by weight of the fluoropolymer (1). .

  In addition to the above components (1) to (3), the coating agent may contain other water repellents, other oil repellents, fluorescent agents, drying rate adjusting agents, cross-linking agents, film-forming aids, Solubilizers, surfactants, antifreeze agents, viscosity modifiers, UV absorbers, antioxidants, pH adjusters, antifoaming agents, slipperiness adjusters, antistatic agents, hydrophilic agents, antibacterial agents, antiseptics, You may contain an insect repellent, an aromatic agent, a flame retardant, a color tone regulator, etc.

  In the present invention, a coating agent is applied to a substrate to impart moisture resistance to the substrate.

Examples of the substrate include electronic parts and electric parts. In this specification, the term “electronic component” simply means an electrical component in addition to an electronic component.
The base material is an electronic component and an electrical component that are disposed in a place exposed to moisture regardless of whether they are outdoors or indoors, and is an electronic component and an electrical component on which various elements are mounted. Examples of the substrate include a circuit board and a hard disk bearing. Electronic parts and electrical parts are used in articles such as telephones, traffic lights, air conditioner outdoor units, switchboards, pole capacitors, mobile phones, portable relay antennas, automotive electronic equipment, ship electronic equipment, vending machines, mobile personal computers, etc. Is done.

  Examples of electronic components include various printed wiring boards (electronic circuit boards) and hybrid ICs, but are not limited to these.

  Epoxy resin, phenolic resin, BT resin, polyimide, glass base fabric (fiber), aluminum, etc. are used as substrate materials for such electronic components, and copper, silver, gold, platinum and other metals as circuit materials, Solder is scattered on the substrate. The coating composition of the present invention does not alter these materials.

  Moreover, as an electrical component, a switchboard etc. can be illustrated besides the various electric devices incorporating the above-described electronic components. Specifically, outdoor units for air conditioners, mobile phones, car navigation systems, solar panels, lighting, traffic lights, mobile relay antennas, automotive electronics, vending machines, mobile PCs, unmanned antenna stations, radios, marine equipment, An example is a watch.

  The coating agent is applied by a brush coating method, a dipping method, a spray method, a roll coating method, a potting method, a casting method, and the like, and is left in the surrounding environment to volatilize an aqueous liquid medium to form a coating film.

  In the present invention, the coating film may be a film made from the coating composition, for example, a cast film. This film provides a moisture-proof effect by wrapping electronic / electrical parts.

The substrate is treated (particularly applied) with the coating agent. The amount of coating agent, 0.05 to 50 g / ^{m 2} in the fluorine-containing polymer in the coating agent, for example 0.1~25g / ^{m 2,} preferably from 0.5 to 5.0 g / ^{m 2.} The application may be performed once but may be divided into a plurality of times.

  “Treatment” means that the treating agent is applied to the substrate by dipping, spraying, coating, or the like. By the treatment, the fluoropolymer which is an active ingredient of the treatment agent adheres to the surface of the base material (and / or penetrates into the base material).

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this is only a specific example of this invention, and this invention is not limited to it. In the following, “%” means “% by weight” unless otherwise specified.

Test methods and measurement methods employed in the present invention and the following examples are as follows.
(1) Water / oil repellency The water / oil repellency of the copper foil portion of the test piece was evaluated using a contact angle meter (CONTACT-ANGLE METER CA-DT, manufactured by Kyowa Interface Science Co., Ltd.).

(2) Resistance Value The surface resistance of the test piece was measured with an electric resistance measuring device (ULTRA HIGH RESISTANCE METER R8340A manufactured by Advantest Corporation).

(3) Water resistance The test piece was immersed in deionized water at 25 degrees for 24 hours. The surface resistance of the test piece after immersion was measured with an electric resistance measuring machine.

(4) Drying property A coating agent was applied to the glass fiber reinforced epoxy resin plate to which the comb electrode substrate was attached by a brush coating method, and the surface resistance of the test piece was measured with an electric resistance measuring device while drying at room temperature.

(5) High-temperature and high-humidity resistance Place the test piece in a high-temperature and high-humidity tank maintained at 85 RH% at 85 ° C for 48 hours and continuously apply a voltage of 16V. When measuring the resistance value, a voltage of 100 V was applied, and the change with time of the resistance value under high temperature and high humidity was examined.

Production Example 1 (Preparation of aqueous solution of “Rf (C6) -DM” polymer)
CF ₃ CF _2- (CF ₂ CF ₂ ) ₂ -CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ [Rf (C6) methacrylate] 73.30 g, dimethylaminoethyl methacrylate (DM) 26.70 g, isopropanol (IPA) 150.00 After stirring and dissolving g in a four-necked flask and maintaining at 60 ° C. while purging with nitrogen, 2 g of t-butyl peroxypivalate was added and reacted at 60 ° C. for 6 hours to obtain a polymer solution. The completion of the polymerization reaction was confirmed by gas chromatography to have a monomer conversion rate of 99% or more. Further, while this polymer solution was stirred at 60 ° C., a mixed solution of 10.20 g of CH ₃ COOH (acetic acid) and 300 g of ion-exchanged water was added dropwise. Thereafter, the IPA is removed under reduced pressure, and the solid content of this solution is obtained from the evaporation residue after heating at 130 ° C. for 1 hour, diluted with ion-exchanged water so that the solid content becomes 25 mass%, and is a transparent and stable polymer. An aqueous solution was obtained.

Production Example 2 [Rf (C4) Cl-DM] and Production Example 3 [Rf (C2) -DM]
In Production Example 1, Rf (C6) methacrylate and DM are replaced with CF ₃ CF ₂ CF ₂ CF ₂ —CH ₂ CH ₂ OCOC (Cl) ═CH ₂ [Rf (C4) chloroacrylate] 63.00 g and DM 37.00 g, respectively. A product produced in exactly the same manner except for the above was designated Production Example 2. Production Example 3 was produced in exactly the same manner except that it was replaced with 59.62 g of CF ₃ CF ₂ —CH ₂ OCOC (CH ₃ ) ═CH ₂ [Rf (C2) methacrylate] and 40.38 g of DM.

Example 1
Glass fiber reinforced epoxy resin plate with comb-shaped electrode substrate (material: CEM3, plate thickness: 1.6mm, copper foil thickness: 18μm, pattern width: 0.75mm or 0.3mm), coating agent by brush coating method (Production Example 1) -3 polymer aqueous solution) was applied and dried to prepare a test piece having a coating thickness of 2.7 μm. About this test piece (test piece which apply | coated the polymer aqueous solution of Example 1), water and oil repellency, resistance value, and high temperature-and-humidity resistance were measured. The results are shown in Tables 1 to 4.

Example 2
The same procedure as in Example 1 was repeated except that the film thickness of the coating was changed to 0.8 μm. The results are shown in Tables 1 to 4.

Comparative Examples 1 and 2
The same procedure as in Example 1 was repeated except that the type of coating agent and the film thickness of the coating were changed. As a comparative example, a urethane dispersion (“Takelac W-6020” manufactured by Mitsui Chemicals Polyurethane Co., Ltd.) and an acrylic dispersion (“ViniBran Binibrand T0-453N” manufactured by Nissin Chemical Industry Co., Ltd.) were used. The results are shown in Tables 1 to 4.

  The coating agent of the present invention can be used for moisture-proof coating of electronic parts and electric parts. Examples of electronic components and electrical components are circuit boards, hard disk bearings, and the like. Electronic parts and electric parts are, for example, telephones, traffic lights, air conditioner outdoor units, switchboards, pole capacitors, mobile phones, portable relay antennas, automobile electronic devices, ship electronic devices, vending machines, mobile personal computers, and the like.

Claims (13)

A coating agent for electronic parts comprising a fluorine-containing compound (1) and an aqueous liquid medium (2),
The coating agent for electronic parts is a solution,
The fluorine-containing compound (1)
(A) a water-soluble polymer having a repeating unit derived from a fluorine-containing acrylate monomer, and (B) a repeating unit derived from an amino group-containing monomer,
The fluorine-containing acrylate monomer (A) is
At least one fluorine-containing group selected from the group consisting of perfluoroalkyl groups, perfluoroalkenyl groups and perfluoroether groups, and
Formula: —O—CO—CX═CH ₂
[Wherein, X represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a CFX ¹ X ² group (where X ¹ and X ² is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom or an iodine 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. ]
The coating agent for electronic components which is a monomer which has an unsaturated group represented by these . The fluorine-containing compound (1)
The coating agent according to claim 1, which is a water-soluble polymer comprising (A) a repeating unit derived from a fluorine-containing acrylate monomer and (B) a repeating unit derived from an amino group-containing monomer. Electronic / electrical electronic components selected from the group consisting of telephones, traffic lights, air conditioner outdoor units, switchboards, pole capacitors, mobile phones, portable relay antennas, automotive electronics, ship electronics, vending machines, and mobile PCs The coating agent according to claim 1, which is used in a device. The coating agent according to any one of claims 1 to 3 , wherein the coating agent for electronic parts is an aqueous solution . The fluorine-containing acrylate monomer (A) has the formula:
CH ₂ = C (−X) −C (= O) −OY−Rf (I)
[Wherein, X represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a CFX ¹ X ² group (where X ¹ and X ² is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom or an iodine 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,
Y is a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom, an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom, a cyclic aliphatic group or an aromatic group. An aliphatic group, a —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (where R ¹ is an alkyl group having 1 to 4 carbon atoms) or a —CH ₂ CH (OY ¹ ) CH ₂ — group ( Y ¹ is a hydrogen atom or an acetyl group.
Rf is a linear or branched perfluoroalkyl group of 1 to 21 carbon atoms, or perfluoroalkenyl group having 2 to 21 carbon atoms, repeating _{units: -C 3 F 6 O -,} - C 2 F 4 O A perfluoroether group in which the total number of at least one repeating unit selected from the group consisting of — and —CF ₂ O— is 1 to 200. ]
The coating agent according to any one of claims 1 to 4, wherein Rf of the fluorine-containing acrylate monomer (A) is a coating agent according to claim 5 which is a perfluoroalkenyl group perfluoroalkyl group or 3 to 6 carbon atoms having 2 to 6 carbon atoms. The amino group-containing monomer (B) has the formula:

[Wherein R ¹¹ , R ¹² and R ²¹ are the same or different and are a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, Y ¹¹ is an oxygen atom or NH, and Z is 1 to 1 carbon atom. 10 branched or straight chain alkylene groups. R ¹¹ and R ¹² may be bonded to each other to form a ring together with the adjacent nitrogen atom. ]
The coating agent according to any one of claims 1 to 6, wherein   The coating agent according to any one of claims 1 to 7, wherein the aqueous liquid medium (2) is (i) water or (ii) a mixture of water and a water-soluble organic solvent.   The coating agent according to any one of claims 1 to 8, comprising a fluorine-containing compound (1), an aqueous liquid medium (2), and an additive (3). The coating agent of Claim 9 which contains the fluorescent agent or the pigment | dye as an additive (3).   The manufacturing method of the processing electronic component which consists of apply | coating an electronic component or an electrical component with the coating agent in any one of Claims 1-10.   12. The method of claim 11, comprising removing the aqueous liquid medium after applying the coating agent to the electronic or electrical component.   Processed electronic parts manufactured by the method according to claim 11 or 12.