WO2018182002A1 - Composition for forming fluorine-containing sealing material - Google Patents

Abstract

Provided is a composition for forming a fluorine-containing sealing material, the composition containing a fluorine-containing polymer and a fluorine-based solvent and having a fluorine-containing polymer concentration within the range of 7-33% by mass. The fluorine-containing polymer is (A) a fluorine-containing polymer that includes a structural component derived from a monomer component including a fluoroalkyl-group-containing (meth)acrylic acid ester and an Si-atom-containing polymerizable monomer, and/or (B) a fluorine-containing polymer that includes a structural component derived from an Si-atom-containing mercaptan and a structural component derived from a monomer component including the fluoroalkyl-group-containing (meth)acrylic acid ester, and the Si-atom-containing polymerizable monomer and the Si-atom-containing mercaptan each independently include at least one Si atom bonded with a hydroxyl group or a hydrolyzable group.

Description

Composition for forming fluorine-containing sealant

The present invention relates to a composition for forming a fluorine-containing sealant.

In a gap (gap, for example, a minute gap) between electronic members in an electronic device such as a display and a printed board, a sealing material for filling the gap is provided. The sealing material is required to have waterproofness for protecting members included in the electronic device.

On the other hand, it is known that certain fluorine-containing compounds can provide excellent waterproof and moisture-proof properties to the substrate when used for the surface treatment of the substrate (Patent Documents 1 to 3). For example, Patent Document 1 discloses an acrylic acid ester having a fluoroalkyl group ester-bonded to a carboxyl group directly or via a divalent organic group and having a substituent at the α-position, and high softening Waterproofing and / or moisture-proof coating compositions containing point monomers are described. In such a waterproof and / or moisture-proof coating composition, a thin film having a thickness of several μm is usually formed.

JP 2013-253240 A JP 2009-46575 A JP2013-231168A

The present inventor has tried to use a coating composition containing a fluorine-containing compound in order to fill a gap such as an electronic member. However, it has been found that it is difficult to form a film having a large film thickness with a coating composition that has been studied so far, and it is not possible to obtain a film thickness sufficient to fill the gap.

An object of the present invention is to provide a composition containing a fluorine-containing compound, which is suitable for filling voids such as electronic members.

The present inventor tried to fill the voids with a coating composition having a high concentration of fluorine-containing compound. However, it has been found that the coating compositions that have been studied in the past have a small film thickness after curing and it is difficult to sufficiently fill the voids. As a result of further studies by the present inventors, it has been found that the above-mentioned voids can be sufficiently filled by using a composition containing a specific polymer at a specific concentration.

That is, according to the first aspect of the present invention,
(I) Formula (1):

[Where:
Rf is a fluoroalkyl group;
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 linear or branched group having 1 to 20 carbon atoms A branched alkyl group;
Y is a direct bond or a divalent organic group. ]
Is a polymer containing a structural unit derived from a fluoroalkyl group-containing (meth) acrylic acid ester represented by the following (A) and / or (B) fluorine-containing polymer (A) containing the fluoroalkyl group ( A fluorine-containing polymer comprising a component derived from a monomer component comprising a (meth) acrylate ester and a Si atom-containing polymerizable monomer,
(B) a fluorine-containing polymer comprising a component derived from a Si atom-containing mercaptan and a component derived from a monomer component containing the fluoroalkyl group-containing (meth) acrylic acid ester,
And (II) containing a fluorinated solvent,
The Si atom-containing polymerizable monomer and the Si atom-containing mercaptan each independently contain at least one Si atom bonded to one or more hydroxyl groups or hydrolyzable groups,
Provided is a composition for forming a fluorine-containing sealant having a fluorine-containing polymer concentration in the range of 7 to 33% by mass.

According to the second aspect of the present invention, there is provided an article including a sealing material formed using the above-mentioned composition for forming a fluorine-containing sealing material.

According to the present invention, it is possible to obtain a composition for forming a fluorine-containing sealing material suitable for filling a gap such as an electronic member.

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

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

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

In the present specification, unless otherwise specified, an alkyl group and a phenyl group may be unsubstituted or substituted. The substituent of such a group is not particularly limited, and examples thereof include one or more groups selected from a halogen atom, a C _1-6 alkyl group, a C _2-6 alkenyl group, and a C _2-6 alkynyl group. Can be mentioned.

In the present specification, the “hydrolyzable group” means a group that can undergo a hydrolysis reaction, that is, a group that can be removed from the main skeleton of the compound by the hydrolysis reaction. Examples of the hydrolyzable group include —OR, —OCOR, —O—N═CR ₂ , —NR ₂ , —NHR, halogen (in these formulas, R represents a substituted or unsubstituted carbon atom having 1 to 4 carbon atoms). And the like, preferably —OR (that is, an alkoxy group). Examples of R include unsubstituted alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group and isobutyl group; substituted alkyl groups such as chloromethyl group. Among them, an alkyl group, particularly an unsubstituted alkyl group is preferable, and a methyl group or an ethyl group is more preferable. In the present specification, the “hydroxyl group” written together with the “hydrolyzable group” is not particularly limited, but may be generated by hydrolysis of a hydrolyzable group.

[Composition for forming fluorine-containing sealant]
The composition for forming a fluorine-containing sealing material of the present invention is a composition for forming a fluorine-containing sealing material suitable for filling a gap (gap) of, for example, an electronic member or an electronic device including the electronic member. In the following, the fact that the gap filling property is good may be described as being suitable for filling the gap as described above.

The composition for forming a fluorine-containing sealing material of the present invention contains a fluorine-containing polymer and a fluorine-based solvent, and the concentration of the fluorine-containing polymer is 7 to 33% by mass with respect to 100% by mass of the composition for forming a fluorine-containing sealing material. is there. The fluorine-containing polymer contained in the composition for forming a fluorine-containing sealant of the present invention has the formula (1):

[Where:
Rf is a fluoroalkyl group;
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 linear or branched group having 1 to 20 carbon atoms A branched alkyl group;
Y is a direct bond or a divalent organic group. ]
Is a polymer containing a structural unit derived from a fluoroalkyl group-containing (meth) acrylic acid ester (hereinafter sometimes simply referred to as “fluoroalkyl group-containing (meth) acrylic acid ester”). ) And / or (B).
(A) A fluorine-containing polymer containing a component derived from a monomer component containing the fluoroalkyl group-containing (meth) acrylic acid ester and a Si atom-containing polymerizable monomer.
(B) A fluorine-containing polymer comprising a component derived from a Si atom-containing mercaptan and a component derived from a monomer component containing the fluoroalkyl group-containing (meth) acrylic acid ester.
However, the Si atom-containing polymerizable monomer and the Si atom-containing mercaptan each independently contain Si atoms bonded to at least one hydroxyl group or hydrolyzable group.

(I) Fluoropolymer The components for obtaining the fluoropolymer will be described below.

The fluoroalkyl group-containing (meth) acrylic acid ester is one in which a fluoroalkyl group is ester-bonded directly or via a divalent organic group to acrylic acid that may have a substituent at the α-position. In the present specification, the fluoroalkyl group-containing acrylic acid ester and the fluoroalkyl group-containing methacrylic acid ester are also collectively referred to as “fluoroalkyl group-containing (meth) acrylic acid ester”. The fluoroalkyl group-containing (meth) acrylic acid ester is a chemical resistance (for example, salt water, acid or basic aqueous solution, acetone) of a fluorine-containing sealant formed using the composition for forming a fluorine-containing sealant of the present invention. , Oleic acid or hexane, particularly resistance to salt water).

The fluoroalkyl group-containing (meth) acrylic acid ester is represented by the following formula (1):

It is represented by

In the above formula (1), 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 a hydrogen atom, a fluorine atom Or a chlorine atom), a cyano group, a linear or branched fluoroalkyl group having 1 to 21 carbon atoms, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a carbon number of 1 to 20 straight-chain or branched alkyl groups. X is preferably a hydrogen atom, a fluorine atom, a chlorine atom, or a methyl group.

In another embodiment, X is preferably a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a CFX ¹ X ² group (X ¹ and X ² are as defined above), a cyano group, a carbon number of 1 to 21 is a linear or branched fluoroalkyl group, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, or a linear or branched alkyl group having 1 to 20 carbon atoms, preferably Is a fluorine atom, a chlorine atom, or a methyl group.

In the above formula (1), Y is a direct bond or a divalent organic group. The divalent organic group is as defined above. Y is preferably a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom, A cyclic aliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, an araliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, —CH ₂ CH ₂ N (R ¹ ) SO ₂ — group (where R ¹ is an alkyl group having 1 to 4 carbon atoms), —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), more preferably a direct bond, an aliphatic group having 1 to 10 carbon atoms, or —CH ₂ CH (OH) A CH ₂ — group, more preferably an aliphatic group having 1 to 4 carbon atoms, or a —CH ₂ CH (OY ¹ ) CH ₂ — group.

Examples of the aliphatic group include an alkylene group having 1 to 10 carbon atoms.

The aliphatic group is preferably, for example, an alkylene group having 1 to 4 carbon atoms.

Examples of the aromatic group include a phenylene group.

Examples of the cycloaliphatic group include a cycloalkylene ring.

Examples of the araliphatic group include —Y ²¹ —Ar—Y ²² —. Y ²¹ and Y ²² are each independently a direct bond or an alkylene group having 1 to 12 carbon atoms, and Ar can be a substituted or unsubstituted arylene group (more specifically, a phenylene group). .

In the above formula (1), Rf is a fluoroalkyl group, preferably a linear or branched fluoroalkyl group having 1 to 20 carbon atoms, more preferably at least one hydrogen atom. It is an alkyl group substituted with a fluorine atom, and includes a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

The fluoroalkyl group-containing (meth) acrylic acid ester represented by the above formula (1) has a good solubility in a fluorinated solvent described below, particularly hydrofluoroether, and Rf has 4 to 6 carbon atoms. It is preferably a linear or branched fluoroalkyl group. In order to further improve the waterproof resistance of the formed gap fill material (sealing material), the fluoroalkyl group-containing (meth) acrylic acid ester represented by the above formula (1) is further in the α position represented by X. Is preferably an α-substituted acrylate ester in which the substituent is a group or atom other than a hydrogen atom. From the viewpoint of forming a gap fill material having good waterproof properties using a low-priced raw material, the α-position substituent X is preferably a methyl group, a chlorine atom or a fluorine atom. From the viewpoint of improving the film formability, the α-position substituent X is particularly preferably a methyl group.

In one embodiment, the fluoroalkyl group-containing (meth) acrylic acid ester represented by the above formula (1) is a fluorine-based solvent described later, for example, at least one hydrogen atom is a fluorine atom and at least one hydrogen Rf is preferably a linear or branched fluoroalkyl group having 4 to 6 carbon atoms from the viewpoint of good solubility in an olefin substituted with a chlorine atom. In order to further improve the waterproofing resistance of the formed gap fill material, the fluoroalkyl group-containing (meth) acrylic acid ester represented by the above formula (1) further has an α-position substituent represented by X. An α-substituted acrylate ester that is a group or atom other than a hydrogen atom is preferable. From the viewpoint of forming a gap fill material having good waterproof properties using a low-priced raw material, the α-position substituent X is preferably a methyl group, a chlorine atom or a fluorine atom. From the viewpoint of improving the film formability, the α-position substituent X is particularly preferably a methyl group.

In one embodiment, Rf is a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms, and more preferably a linear or branched perfluoroalkyl group having 4 to 6 carbon atoms. .

Specific examples of the fluoroalkyl group-containing (meth) acrylic acid ester represented by the above general formula (1) are as follows.

The fluoroalkyl group-containing (meth) acrylic acid ester may be used alone or in combination of two or more.

The Si atom-containing polymerizable monomer contains at least one Si atom bonded to one or more hydroxyl groups or hydrolyzable groups. The Si atom-containing polymerizable monomer preferably contains at least one Si atom bonded to at least one hydroxyl group or hydrolyzable group and at least one polymerizable functional group in the molecule. The Si atom-containing polymerizable monomer contributes to improvement in adhesion to the wall surface of the gap or a member previously filled in the gap, and improvement in wear resistance of the fluorine-containing sealing material.

In the Si atom-containing polymerizable monomer, the polymerizable functional group is preferably a group containing a polymerizable unsaturated bond, more preferably a group containing a polymerizable ethylenically unsaturated bond. One polymerizable functional group is preferably present in the molecule of the Si atom-containing polymerizable monomer.

In the Si atom-containing polymerizable monomer, the Si atom is preferably bonded to 1 to 3 hydroxyl groups or hydrolyzable groups, and more preferably bonded to 3 hydroxyl groups or hydrolyzable groups. The hydrolyzable group is as defined above.

The Si atom-containing polymerizable monomer is preferably the following formula (2):

It is represented by

In the above formula (2), R ² , R ³ and R ⁴ are the same or different and are a hydroxyl group, a hydrolyzable group or an alkyl group having 1 to 4 carbon atoms, and R ² , R ³ and R ⁴ At least one is a hydroxyl group or a hydrolyzable group. The hydrolyzable group is as defined above. More preferably, R ² , R ³ and R ⁴ are the same or different and are an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms (—OR), and R ² , R ³ and R 4 ^At least one of 4 is an alkoxy group having 1 to 4 carbon atoms. R is as defined above. R ² , R ³ and R ⁴ are each independently more preferably an alkoxy group, more preferably each independently a methoxy group or an ethoxy group. For example, R ² , R ³ and R ⁴ can all be methoxy groups.

In the above formula (2), R ⁵ is a group containing a polymerizable unsaturated bond, and preferably a group containing a polymerizable ethylenically unsaturated bond.

Specifically, the compound represented by the formula (2) can be represented by the following formula (2 ′).

In the above formula (2 ′), R ² , R ³ and R ⁴ are as defined above. R ¹⁴ represents a hydrogen atom, a fluorine atom, a chlorine atom, or an alkyl group having 1 to 4 carbon atoms, and is preferably a hydrogen atom, a chlorine atom, or a methyl group. Y ² represents a direct bond or a divalent organic group, and is preferably a direct bond, an alkylene group having 1 to 10 carbon atoms, or an araliphatic group having 6 to 15 carbon atoms. The araliphatic group has the same meaning as described above.

Specific examples of the Si atom-containing polymerizable monomer include monomers represented by the following formula.

In the above formulas, R ² , R ³ and R ⁴ are as defined above, R ⁶ is a hydrogen atom, a methyl group, or a chlorine atom, and h is 1 to 12 (eg, 1 to 10). It is an integer.

In one embodiment, R ² , R ³ and R ⁴ are a methoxy group or an ethoxy group, preferably a methoxy group, R ⁶ is a methyl group, and h is an integer of 1-12.

The above Si atom-containing polymerizable monomers may be used alone or in combination of two or more.

The monomer component may contain a high softening point monomer or other monomer as necessary.

The high softening point monomer is a monomer having a glass transition point or melting point of a homopolymer composed of a 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, preferably 120 ° C. or higher, and the polymer having no glass transition point has a melting point of 100 ° C. or higher, preferably Needs to be 120 ° C. or higher.

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

The above high softening point monomer can contribute to the improvement of waterproofing and / or moisture-proof performance of the fluorine-containing sealing material formed from the fluorine-containing sealing material forming composition. Furthermore, by including a high softening point monomer, the fluorine-containing sealant can have improved hardness and better durability such as wear resistance.

In particular, by using the high softening point monomer as a monomer component, the sealing material has very good dynamic water repellency that serves as an index indicating the removal performance of water droplets attached to the surface. The dynamic water repellency can be evaluated by the falling angle of water.

As the high softening point monomer, the following general formula (4)
CH ₂ = C (R ¹¹ ) COOR ¹² (4)
(Wherein R ¹¹ is H or CH ₃ , and R ¹² is a group having a saturated alkyl group having 4 to 20 carbon atoms and a ratio of carbon atoms to hydrogen atoms of 0.55 or more). (Meth) acrylic acid ester; methyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate and the like.

The high softening point monomer is preferably a (meth) acrylic acid ester represented by the general formula (4).

In the general formula (4), a saturated alkyl group having 4 to 20 carbon atoms and a ratio of carbon atoms to hydrogen atoms of 0.55 or more (more specifically, a ratio of carbon atoms having 4 to 20 carbon atoms to hydrogen atoms is Specific examples of 0.58 or more saturated alkyl groups include isobornyl, bornyl, phensil (all of which are C ₁₀ H ₁₇ , carbon atom / hydrogen atom = 0.58), adamantyl (C ₁₀ H ₁₅ , carbon atom) / Hydrogen atom = 0.66), norbornyl (C ₇ H ₁₂ , carbon atom / hydrogen atom = 0.58) and other groups having a bridged hydrocarbon 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).

Note that the ratio of carbon atoms to hydrogen atoms represents the ratio of the number of carbon atoms to the number of hydrogen atoms.

Examples of the (meth) acrylic acid ester represented by the general formula (4) include (meth) acrylate having an isobornyl group, (meth) acrylate having a norbornyl group, (meth) acrylate having an adamantyl group, and the like. it can. 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, 2-ethyl-2-adamantyl (meth) Acrylate, 3-hydroxy-1-adamantyl (me ) Acrylate can be exemplified by 1-adamantyl -α- trifluoromethyl (meth) acrylate.

The other monomer may be any monomer that can be copolymerized with a fluoroalkyl group-containing (meth) acrylic acid ester, and can be selected from a wide range as long as it does not adversely affect the performance of the resulting fluoropolymer. 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 Si atom-containing mercaptan contains at least one Si atom bonded to at least one hydroxyl group or hydrolyzable group.

The Si atom-containing mercaptan functions as a chain transfer agent, and the degree of polymerization of the fluoropolymer can be adjusted by adding it. Furthermore, a part of Si atom-containing mercaptan, specifically, a hydroxyl group or hydrolyzable group bonded to an Si atom contained in the Si atom-containing mercaptan is contained in the fluorine-based polymer. This improves the adhesion between the formed fluorine-containing sealing material and the elastomer (for example, silicone) and / or the wall surface of the void. Therefore, the Si atom-containing mercaptan can contribute to the formation of a fluorine-containing sealing material excellent in wear resistance.

As said Si atom containing mercaptan, if it is a compound which has a Si atom couple | bonded with at least 1 or more hydroxyl group or hydrolyzable group, and a mercapto group, it can use without limitation. Preferred examples of the Si atom-containing mercaptan include compounds represented by the following formula (3).

In the above formula (3), R ⁷ , R ⁸ and R ⁹ are the same or different and are a hydroxyl group, a hydrolyzable group or an alkyl group having 1 to 4 carbon atoms, and R ⁷ , R ⁸ and R ⁹ At least one is a hydroxyl group or a hydrolyzable group. The hydrolyzable group is as defined above. R ⁷ , R ⁸ and R ⁹ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms (—OR), and at least one of R ⁷ , R ⁸ and R ⁹ More preferably, it is an alkoxy group having 1 to 4 carbon atoms. R ⁷ , R ⁸ and R ⁹ are each independently more preferably an alkoxy group, particularly preferably each independently a methoxy group or an ethoxy group. For example, R ⁷ , R ⁸ and R ⁹ can all be methoxy groups.

In the above formula (3), R ¹⁰ is an alkylene group having 1 to 12 carbon atoms. The alkylene group is linear or branched, and is preferably a linear alkylene group.

In one embodiment, R ⁷ , R ⁸ and R ⁹ are each independently a methoxy group or an ethoxy group, preferably a methoxy group, and R ¹⁰ is an alkylene group having 1 to 5 carbon atoms.

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

The above-mentioned Si atom-containing mercaptans may be used alone or in combination of two or more.

Hereinafter, for the fluorine-containing polymer contained in the composition for forming a fluorine-containing sealing material of the present invention,
(A) Fluoropolymer containing a component derived from a monomer component containing a fluoroalkyl group-containing (meth) acrylic acid ester and a Si atom-containing polymerizable monomer (hereinafter sometimes referred to as “fluorinated polymer 1”) When,
(B) a fluorine-containing polymer (hereinafter referred to as “fluorine-containing polymer 2”) including a component derived from a Si atom-containing mercaptan and a component derived from a monomer component containing a fluoroalkyl group-containing (meth) acrylic ester Sometimes)
It is divided and described. However, in each of the fluoropolymer 1 and the fluoropolymer 2, the Si atom-containing polymerizable monomer and the Si atom-containing mercaptan each independently contain at least one Si atom bonded to one or more hydroxyl groups or hydrolyzable groups. Including.

The fluoropolymer 1 can be obtained by polymerizing a monomer component containing a fluoroalkyl group-containing (meth) acrylic acid ester and a Si atom-containing polymerizable monomer as essential components. That is, the fluorine-containing polymer 1 is a fluorine-containing polymer obtained by polymerizing a monomer component containing a fluoroalkyl group-containing (meth) acrylic acid ester and a Si atom-containing polymerizable monomer. The fluoropolymer 1 is a copolymer having a structural unit derived from a fluoroalkyl group-containing (meth) acrylic acid ester and a structural unit derived from a Si atom-containing polymerizable monomer.

The weight average molecular weight of the fluoropolymer 1 is preferably 3,000 to 500,000, more preferably 5,000 to 300,000, still more preferably 20,000 to 100,000. The weight average molecular weight of the fluoropolymer 1 can be determined by GPC (gel permeation chromatography). For example, the weight average molecular weight can be obtained by GPC using a mixed solvent of HCFC225 / hexafluoroisopropanol (= 90/10 weight) as an elution solvent (in terms of standard polymethyl methacrylate).

The fluoroalkyl group-containing (meth) acrylic acid ester and the Si atom-containing polymerizable monomer have the same meanings as described above.

The fluorine-containing polymer 1 comprises a structural unit derived from the fluoroalkyl group-containing (meth) acrylic ester and a structural unit derived from the Si atom-containing polymerizable monomer in a mass ratio of 99.9: 0.1 to 50 : 50, preferably 96: 4 to 70:30, more preferably 96: 4 to 90:10.

In a preferred embodiment, in the fluoropolymer 1, the fluoroalkyl group-containing (meth) acrylic ester is represented by the following formula (1), and the Si atom-containing polymerizable monomer is represented by the following formula (2). The In the formula, Rf, X, Y, and R ² to R ⁵ are as defined above.

In this embodiment, the obtained fluoropolymer 1 is a copolymer having a structural portion represented by the following chemical formula (5). The terminal of the fluoropolymer 1 may be a group derived from a terminator, a group derived from an initiator, or a group derived from a monomer.

The composition for forming a fluorine-containing sealing material containing the fluorine-containing polymer 1 can contribute to the formation of a fluorine-containing sealing material having a large thickness. The composition for forming a fluorine-containing sealing material containing the fluorine-containing polymer 1 is excellent in abrasion resistance, has good waterproof and / or moisture-proof performance, can contribute to the formation of a sealing material having excellent water repellency and good water drainage. Furthermore, the composition for forming a fluorine-containing sealant containing the fluorine-containing polymer 1 has chemical resistance, for example, against salt water (for example, 5% salt water), acid or basic aqueous solution, acetone, oleic acid or hexane, particularly salt water. It can contribute to the formation of a sealing material with good resistance.

In the above chemical formula (5), X, Y, Rf and R ² to R ⁴ are as defined above. R ^{5 ′} is a trivalent group derived from the group R ⁵ in the formula (2), that is, a trivalent group derived from a group containing a polymerizable unsaturated bond.

In the above chemical formula (5), the structural unit enclosed in parentheses with l is a structural unit derived from a fluoroalkyl group-containing (meth) acrylic acid ester, and a structural unit enclosed in m with m The unit is a structural unit derived from the Si atom-containing polymerizable monomer. Note that the order of presence of each repeating unit with l and m in parentheses is arbitrary in the formula.

In the above chemical formula (5), l and m are each independently an integer of 1 or more. The sum of l and m is preferably a numerical value with a weight average molecular weight of 3,000 to 500,000.

In one embodiment, in the chemical formula (5), l: m is preferably in the range of 99.9: 0.5 to 50:50, and more preferably in the range of 95: 5 to 70:30. Preferably, it is in the range of 95: 5 to 80:20, more preferably in the range of 95: 5 to 85:15.

In one embodiment, in the above chemical formula (5), l: m may be in the range of 93: 7 to 80:20, or may be in the range of 90:10 to 80:20.

In one embodiment, the monomer component includes a high softening point monomer in addition to the fluoroalkyl group-containing acrylic ester and the Si atom-containing polymerizable monomer. In this embodiment, the fluorine-containing polymer 1 is a copolymer further containing a structural unit based on a high softening point monomer. The high softening point monomer has the same meaning as described above.

The composition for forming a fluorine-containing sealing material containing the fluorine-containing polymer obtained in this embodiment has good waterproof and moistureproof properties and can contribute to the formation of a sealing material with good hardness.

In a preferred embodiment,
The fluoroalkyl group-containing (meth) acrylic acid ester is represented by the following formula (1);

The Si atom-containing polymerizable monomer is represented by the following formula (2);

The high softening point monomer is a (meth) acrylic acid ester represented by the formula (4) CH ₂ = C (R ¹¹ ) COOR ¹² (4)
It is. In the formula, Rf, X, Y, R ² to R ⁵ , R ¹¹ and R ¹² are as defined above.

In this embodiment, the obtained fluoropolymer 1 is a copolymer having a structural portion represented by the following chemical formula (5 ′). The composition for forming a fluorine-containing sealant containing this copolymer is excellent in abrasion resistance, has good waterproof and / or moisture-proof performance, and further has excellent water repellency and excellent water drainage. Can contribute. The terminal of the fluoropolymer 1 may be a group derived from a terminator, a group derived from an initiator, or a group derived from a monomer.

In the above chemical formula (5 ′), X, Y, Rf, R ² to R ⁴ , R ¹¹ and R ¹² are as defined above. R ^{5 ′} is a trivalent group derived from the group R ⁵ in the formula (2), that is, a trivalent group derived from a group containing a polymerizable unsaturated bond.

In the above chemical formula (5), the structural unit enclosed in parentheses with l ′ is a structural unit derived from a fluoroalkyl group-containing (meth) acrylic acid ester, and is enclosed in parentheses with m ′. The structural unit is a structural unit derived from a Si atom-containing polymerizable monomer, and the structural unit in parentheses with n ′ is a structural unit derived from a high softening point monomer. In addition, the order of presence of each repeating unit with l ', m', and n 'enclosed in parentheses is arbitrary in the formula.

In the above chemical formula (5 '), l', m 'and n' are each independently an integer of 1 or more. The sum of l ′, m ′ and n ′ is preferably a numerical value having a weight average molecular weight of 3,000 to 500,000.

In one embodiment, in the above chemical formula (5 ′), the ratio of l ′, m ′, and n ′ is such that l ′ is in the range of 50 to 99.8 and m ′ is 0.1 to 49.5. In this range, n ′ is preferably in the range of 0.1 to 49.9. More preferably, the ratio of l ′, m ′, and n ′ is such that l ′ is in the range of 65-99.8, m ′ is in the range of 5-29.5, and n ′ is in the range of 0.2-30. Is in range.

The ratio of l ', m' and n 'is preferably such that l' is in the range of 65 to 75, m 'is in the range of 3 to 15, and n' is in the range of 20 to 30.

The monomer component may further contain other monomers as necessary. Other monomers are as defined above.

The above-mentioned other monomers are preferably contained in an amount of 0.1 to 20% by mass with respect to 100% by mass of the entire fluoropolymer 1.

The polymerization method of the fluoropolymer 1 is not particularly limited, but for example, solution polymerization can be performed in a fluorine-based solvent. According to this method, since the formed fluoropolymer 1 has good solubility in a fluorine-based solvent, the polymerization reaction can proceed smoothly without forming a precipitate.

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

It is preferable to use the same solvent as the fluorinated solvent contained in the composition for forming a fluorinated sealant of the present invention as the fluorinated solvent for polymerization. When hydrofluoroether is used as the fluorinated solvent contained in the composition for forming a fluorinated sealant of the present invention, it is preferable to use hydrofluoroether as the fluorinated solvent for polymerization. By using such a fluorinated solvent, a fluorine-containing sealing material-forming composition can be obtained efficiently by omitting the step of separating the fluorinated polymer.

The above-mentioned polymerization fluorinated solvents may be used alone or in combination of two or more.

When the monomer component is polymerized in the fluorinated solvent, for example, the polymerization reaction is performed by dissolving the monomer component in the fluorinated solvent and adding a polymerization initiator while stirring the obtained solution. Can be advanced.

The polymerization initiator is not particularly limited as long as it is a known polymerization initiator for a polymerization reaction. Examples of the polymerization initiator include azo initiators such as azobisisobutyronitrile, methyl azoisobutyrate, azobisdimethylvaleronitrile; benzoyl peroxide, potassium persulfate, ammonium persulfate, benzophenone derivatives, phosphine oxide derivatives, benzoketones Derivatives, phenylthioether derivatives, azide derivatives, diazo derivatives, disulfide derivatives and the like can be used. These polymerization initiators may be used alone or in combination of two or more.

The amount of the polymerization initiator used is not particularly limited, but is usually preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the fluoroalkyl group-containing (meth) acrylic acid ester used as the monomer component. More preferably, the content is 0.1 to 1 part by mass.

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

The concentration of the monomer component in the fluorinated solvent for polymerization is not particularly limited, but is usually preferably 10 to 50% by mass, and more preferably 20 to 40% by mass.

In the monomer component, the amount of the Si atom-containing polymerizable monomer used is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the fluoroalkyl group-containing (meth) acrylic acid ester.

In one embodiment, in the monomer component, the amount of the high softening point monomer used is 0.1 to 49.9 parts by mass with respect to 100 parts by mass of the fluoroalkyl group-containing (meth) acrylic acid ester. Yes, preferably 1 to 25 parts by mass.

The content of other monomers is preferably about 20% by mass or less, more preferably 10% by mass or less, based on the total amount of monomer components used for obtaining the fluoropolymer 1.

The fluoropolymer 2 can be obtained by polymerizing a monomer component containing a fluoroalkyl group-containing (meth) acrylic acid ester in the presence of a Si atom-containing mercaptan. That is, the fluorine-containing polymer 2 is a fluorine-containing polymer obtained by polymerizing a monomer component containing a fluoroalkyl group-containing (meth) acrylic acid ester in the presence of a Si atom-containing mercaptan. The fluoroalkyl group-containing (meth) acrylic acid ester and the Si atom-containing mercaptan have the same meanings as described above.

The monomer component can contain a high softening point monomer and other monomers in addition to the fluoroalkyl group-containing (meth) acrylic acid ester. The high softening point monomer and other monomers have the same meanings as described above.

The weight average molecular weight of the fluoropolymer 2 is preferably 3,000 to 500,000, more preferably 5,000 to 300,000, and still more preferably 20,000 to 100,000. The weight average molecular weight of the fluoropolymer 2 can be determined by GPC. For example, the weight average molecular weight can be obtained by GPC using a mixed solvent of HCFC225 / hexafluoroisopropanol (= 90/10 weight) as an elution solvent (in terms of standard polymethyl methacrylate).

The fluorine-containing polymer 2 comprises a component derived from a fluoroalkyl group-containing (meth) acrylic acid ester and a component derived from a Si atom-containing mercaptan in a mass ratio of 100: 0.01 to 100: 25. Preferably, it is included in the range of 100: 0.1 to 100: 5.

The fluorinated polymer 2 comprises a component derived from a fluoroalkyl group-containing (meth) acrylic acid ester and a component derived from a Si atom-containing mercaptan in a mass ratio of 100: 0.01 to 100: 1. It may be included, and may be included in the range of 100: 0.1 to 100: 1.

In a preferred embodiment, a fluoroalkyl group-containing (meth) acrylic acid ester represented by the above formula (1) is used as a monomer, and a Si atom-containing mercaptan represented by the above formula (3) is used. In this embodiment, the fluoropolymer 2 has the following general formula (6):

It is represented by The fluorine-containing polymer 2 represented by the formula (6) is derived from a polymer chain of a polymer having a structural unit derived from a fluoroalkyl group-containing (meth) acrylic ester and a Si atom-containing mercaptan represented by the formula (3). It is combined with the structure. The fluoropolymer 2 represented by the formula (6) may have a Si atom bonded to a hydroxyl group or a hydrolyzable group at at least one end.

In the general formula (6), X, Y, Rf, and R ⁷ to R ¹⁰ are as defined above. k is preferably a numerical value corresponding to the above-mentioned weight average molecular weight, that is, a numerical value such that the weight average molecular weight of the polymer of the general formula (6) is 3,000 to 500,000, and 3,000 to 500,000. Is more preferable, and a numerical value of 20,000 to 100,000 is even more preferable.

The composition for forming a fluorine-containing sealing material containing the fluorine-containing polymer 2 can contribute to the formation of a fluorine-containing sealing material having a large thickness. The composition for forming a fluorine-containing sealing material containing the fluorine-containing polymer 2 is excellent in abrasion resistance, has good waterproof and / or moisture-proof performance, can contribute to the formation of a sealing material having excellent water repellency and good drainage. Furthermore, the composition for forming a fluorine-containing sealant containing the fluorine-containing polymer 2 is used to form a sealant having good chemical resistance, for example, salt water, acid or basic aqueous solution, acetone, oleic acid or hexane, particularly salt water. Can contribute.

In one embodiment, a high softening point monomer can be further used as a monomer component together with a fluoroalkyl group-containing (meth) acrylic acid ester when the fluoropolymer 2 is produced. Specific examples of the high softening point monomer are the same as described above.

In this embodiment, the fluorine-containing polymer 2 includes a structural unit based on a high softening point monomer. More specifically, in addition to the structure represented by the general formula (6), a structural unit based on a high softening point monomer is included.

The fluorinated polymer 2 preferably contains 0.1 to 50 parts by mass, more preferably 1 to 30 parts by mass of the constituent component derived from the high softening point monomer with respect to 100 parts by mass of the entire fluorinated polymer 2. More preferably, the content is 1 to 20 parts by mass.

In one embodiment, when the fluoropolymer 2 is produced, other monomers can be further used as a monomer component together with the fluoroalkyl group-containing (meth) acrylic acid ester. Specific examples of other monomers are the same as described above.

In one embodiment, when the fluorine-containing polymer 2 is produced, a Si atom-containing polymerizable monomer can be further used as a monomer component. The Si atom-containing polymerizable monomer has the same meaning as described above.

In this embodiment, the fluorine-containing polymer 2 further has a structural unit based on the Si atom-containing polymerizable monomer. By using the Si atom-containing polymerizable monomer, the composition for forming a fluorine-containing sealing material containing the fluorine-containing polymer 2 can further contribute to improvement in adhesion to an elastomer (for example, silicone).

The fluorine-containing polymer 2 contains at least one selected from the group consisting of a high softening point monomer, other monomers, and a Si atom-containing polymerizable monomer together with a fluoroalkyl group-containing (meth) acrylic acid ester as a monomer component. be able to.

In addition, as above-mentioned, when X is a chlorine atom or a fluorine atom, the said General formula (6) is obtained using a low-priced raw material, and has high usefulness which can form the gap fill material which has favorable waterproofness. It is a polymer.

In the production of the fluoropolymer 2, the type and amount of the polymerization initiator are the same as those of the fluoropolymer 1.

In the production of fluoropolymer 2, the amount of Si atom-containing mercaptan used is 0.01 to 25 parts by mass with respect to 100 parts by mass of the fluoroalkyl group-containing (meth) acrylic acid ester used as the monomer component. The content is preferably 0.1 to 5 parts by mass.

In the production of the fluoropolymer 2, the amount of the high softening point monomer in the monomer component and the amount of the Si atom-containing polymerizable monomer used are the same as described in the fluoropolymer 1.

The polymerization of the fluoropolymer 2 can be performed under the same conditions as the fluoropolymer 1.

(II) Solvent As the fluorine-based solvent contained in the composition for forming a fluorine-containing sealing material of the present invention, a solvent having a fluorine atom in the molecule and good solubility of the formed fluorine-containing polymer may be used. It is preferable to use a hydrocarbon compound, alcohol or ether having a fluorine atom in the molecular structure. The fluorinated solvent may be aliphatic or aromatic.

The fluorine-based solvent is selected from the group consisting of hydrofluoroether, hydrofluorocarbon, perfluorocarbon, and an olefin in which at least one hydrogen atom is substituted with a fluorine atom and at least one hydrogen atom is substituted with a chlorine atom. It is preferable to use at least 1.

It is preferable to use at least one selected from the group consisting of hydrofluoroether, hydrofluorocarbon, and perfluorocarbon as the fluorinated solvent. Examples of the fluorinated solvent include chlorinated fluorinated hydrocarbons (particularly 2 to 5 carbon atoms), particularly HCFC225 (dichloropentafluoropropane), HCFC141b (dichlorofluoroethane), CFC316 (2, 2, 3, 3). -Tetrachlorohexafluorobutane), Bertrell XF (molecular formula C ₅ H ₂ F ₁₀ ) (manufactured by DuPont), hexafluoro-m-xylene, pentafluoropropanol; fluorinated ethers such as hydrofluoroether; perfluorocarbon, especially fluorinate Mention may be made of FC40 (manufactured by 3M), Fluorinert FC43 (manufactured by 3M), PFC-5060 (manufactured by Solvay); hydrofluorocarbons, particularly Solcan 365mfc (manufactured by Solvay).

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

In the present invention, as the hydrofluoroether,
Formula: C _y F _{2y + 1} —O—C _z H _{2z + 1}
[Wherein y is a number from 1 to 6, and z is a number from 1 to 6. ]
It is preferable to use the compound shown by these. Such hydrofluoroethers include, for example, Novec HFE7100 (Chemical Formula C ₄ F ₉ OCH ₃ ), 7200 (Chemical Formula C ₄ F ₉ OC ₂ H ₅ ), 7300 (Chemical Formula C ₂ F ₅ CF (OCH) manufactured by 3M Corporation, USA. ₃ ) C ₃ F ₇ ) or the like can be used.

In another embodiment, an olefin in which at least one hydrogen atom is substituted with a fluorine atom and at least one hydrogen atom is substituted with a chlorine atom can be used as the fluorine-based solvent. The olefin is preferable from the viewpoint of preventing global warming.

The olefin in which at least one hydrogen atom is substituted with a fluorine atom and at least one hydrogen atom is substituted with a chlorine atom is, for example, a compound having 2 to 5 carbon atoms, more specifically, having 3 carbon atoms. ~ 4 compounds.

As the olefin in which at least one hydrogen atom is substituted by a fluorine atom and at least one hydrogen atom is substituted by a chlorine atom, hydrochlorofluoroolefin or chlorofluoroolefin, which has been recently developed as a low GWP solvent, is used. Can do. In the present specification, the chlorofluoroolefin means an olefin in which at least one of the substituents is substituted with a chlorine atom and the rest are substituted with a fluorine atom. In the hydrochlorofluoroolefin, at least one of the substituents is substituted with a hydrogen atom, at least one with a chlorine atom, and the rest with a fluorine atom.

Examples of the hydrochlorofluoroolefin include 1-chloro-3,3,3-trifluoro-1-propene, 1-chloro-2,3,3-trifluoro-1-propene, and the like; 1,2-dichloro-1,3,3,3-tetrafluoro-1-propene, 1,1,3-trichloro-2,3,3-trifluoro-1-propene, 1,1-dichloro-2, 3,3,3-tetrafluoro-1-propene and the like can be mentioned.

In the composition for forming a fluorine-containing sealing material of the present invention, the fluorine-containing polymer is 7% by mass or more, preferably 10% by mass or more, preferably 33% by mass or less, and 30% by mass with respect to the entire composition. % Or less, and more preferably 25% by mass or less.

In the composition for forming a fluorine-containing sealing material of the present invention, the fluorine-containing polymer is 7 to 33% by mass, preferably 10 to 30% by mass, and preferably 10 to 25% by mass with respect to the entire composition. It is more preferable.

The composition for forming a fluorinated sealant of the present invention has a fluorinated polymer concentration as described above, so that the voids of the electronic member, particularly small voids (micro voids, for example, width 0.1 to 1 mm, depth 0. 1 to 3 mm) can be effectively filled. The composition for forming a fluorine-containing sealing material of the present invention is less likely to cause problems such as clogging of voids during filling, and can uniformly fill the voids. The composition for forming a fluorine-containing sealing material of the present invention has a fluorine-containing polymer concentration as described above, so that there is little volume reduction due to volatilization of the solvent, and it is easy to form a fluorine-containing sealing material with a large film thickness. Become. Therefore, the gap fill property is improved by using the composition for forming a fluorine-containing sealant of the present invention.

The composition for forming a fluorine-containing sealant of the present invention contains a fluorine-containing polymer 1 and / or a fluorine-containing polymer 2, and since these polymers all contain a fluoroalkyl group, they are formed using the above composition. The fluorine sealant exhibits good waterproof performance. The composition for forming a fluorine-containing sealant of the present invention is excellent in abrasion resistance, has good waterproof and / or moisture-proof performance, can contribute to the formation of a sealant having excellent water repellency and good drainage. The fluorine-containing polymer 1 and the fluorine-containing polymer 2 are excellent in chemical resistance, for example, salt water, acid or basic aqueous solution, acetone, oleic acid or hexane, particularly salt water, and therefore the fluorine-containing sealing material of the present invention. The forming composition can contribute to the formation of a fluorine-containing sealing material having good chemical resistance. In the gap, a member such as an electrode or a resin material may be formed in advance. In such a case, by using the composition for forming a fluorine-containing sealing material of the present invention, the electrode or the resin is formed from water or the like. It becomes possible to protect members such as materials.

Furthermore, due to the hydroxyl group or hydrolyzable group contained in the fluoropolymer 1 and the fluoropolymer 2, the adhesion of the sealing material formed from the fluorine-containing sealing material-forming composition of the present invention to the object to be treated is good. become. Examples of the object to be treated include a wall surface of a gap of an electronic member, or a member (for example, glass; metal or metal oxide (for example, metal wiring)) filled in the gap; an elastomer such as silicone; polyethylene or epoxy; Resin materials) or display peripheral materials (optical adhesive, OCA, polarizing plate, etc.).

In one embodiment, the composition for forming a fluorine-containing sealing material contains the fluorine-containing polymer 1 as the fluorine-containing polymer. Fluoropolymer 1 is good for various treatment objects (the same is true for various treatment objects) due to hydroxyl groups or hydrolyzable groups bonded to Si atoms present in the side chain. It exhibits excellent adhesiveness and crosslinkability. Therefore, the fluorine-containing sealant formed using the fluorine-containing sealant-forming composition of this embodiment has good adhesion to the treatment object, abrasion resistance, and waterproof and / or moisture-proof performance.

In one embodiment, the composition for forming a fluorine-containing sealant contains the fluorine-containing polymer 2 as the fluorine-containing polymer. In the fluorine-containing polymer 2, at least a part of the Si atom-containing mercaptan existing during the polymerization reaction is bonded to the polymer chain, and various treatments are performed depending on the hydroxyl group or hydrolyzable group bonded to the Si atom existing at the terminal. In addition to exhibiting good adhesiveness to an object (for various treatment objects, the same meaning as described above), it has crosslinkability. Thereby, the fluorine-containing sealing material formed by using the composition for forming a fluorine-containing sealing material according to this aspect has excellent adhesion to the treatment object and abrasion resistance, and is further waterproof and / or moisture-proof. The performance is also good.

In another embodiment, the fluorine-containing polymer 1 or the fluorine-containing polymer 2 is formed using a monomer component further containing a high softening point monomer. In this embodiment, both the fluorine-containing polymer 1 and the fluorine-containing polymer 2 improve the water repellency of the fluorine-containing sealing material to be formed, and improve water drainage.

The composition for forming a fluorine-containing sealant of the present invention preferably has a viscosity in the range of 10 to 1000 mPa · s, more preferably in the range of 10 to 100 mPa · s, and in the range of 10 to 60 mPa · s. More preferably, it is in the range of 10 to 50 mPa · s. The viscosity is a B-type viscometer at 25 ° C. and can be measured according to JIS K7117-1: 1999. The composition for forming a fluorine-containing sealant of the present invention has the above-described viscosity, so that it is difficult for clogging of voids at the time of filling, and even for voids between electronic members, particularly minute voids having a narrow width. Can be filled uniformly. Since the composition for forming a fluorine-containing sealant of the present invention has the above-described viscosity, it is difficult for bubbles to be formed when filling the gaps, or even if bubbles are generated, the generated bubbles Disappears naturally (without special manipulation). Furthermore, the fluorine-containing sealing material-forming composition of the present invention having the above-described viscosity can form a sealing material having a sufficient film thickness after curing.

In a particularly preferred embodiment, the composition for forming a fluorine-containing sealing material is an α-substituted fluoroalkyl group-containing (meth) acrylic acid ester in which the fluoroalkyl group-containing (meth) acrylic acid ester is represented by the formula (1) [In the formula (1), Rf is a linear or branched fluoroalkyl group having 4 to 6 carbon atoms; X is a group or atom other than a hydrogen atom, preferably a fluorine atom, a chlorine atom, Or it is a methyl group. ], The fluorine-based solvent is a hydrofluoroether. The fluorine-containing polymer formed from an α-substituted fluoroalkyl group-containing acrylic ester in which Rf is a fluoroalkyl group having 4 to 6 carbon atoms has good solubility in hydrofluoroether, and the fluorine-containing polymer formed The sealant has good waterproofness and moistureproofness and good wear resistance.

In the above embodiment, Y is preferably a direct bond, an aliphatic group having 1 to 10 carbon atoms (for example, an alkylene group), or a —CH ₂ CH (OH) CH ₂ — group, more preferably 1 to 4 aliphatic groups (for example, an alkylene group), or a —CH ₂ CH (OY ¹ ) CH ₂ — group. In the formula, Y ¹ is a hydrogen atom or an acetyl group.

In the composition for forming a fluorine-containing sealing material of the present invention, by using a fluorine-based solvent, the above-mentioned fluorine-containing polymer can be stably dissolved, and formation of a fluorine-containing sealing material having good stability that hardly causes precipitation or the like. Composition.

The composition for forming a fluorine-containing sealing material of the present invention may be used as a composition for forming a fluorine-containing sealing material as it is after the polymerization reaction is carried out in a fluorine-based solvent for polymerization, and then the concentration of the polymer is adjusted as necessary. Alternatively, after the polymerization reaction, the fluorine-containing polymer may be separated, and a composition for forming a fluorine-containing sealing material containing the separated fluorine-containing polymer and a fluorine-based solvent may be used.

Preferably, after performing a polymerization reaction using hydrofluoroether as a fluorinated solvent for polymerization, if necessary, the polymer concentration is adjusted using hydrofluoroether to obtain a composition for forming a fluorine-containing sealing material. . By using such a method, a target fluorine-containing sealing material-forming composition can be obtained efficiently.

The composition for forming a fluorine-containing sealing material of the present invention may contain other components in addition to the fluorine-containing polymer and the fluorine-based solvent. Other components include catalysts (metal catalysts such as tin or titanium, or organic catalysts such as acid bases, stabilizers (dehydrating agents, molecular sieves, magnesium sulfate or methyl orthoformate), viscosity modifiers, fillers ( Inorganic materials such as silica, mica, and clay), colorants, and fluorescent agents.

The composition for forming a fluorine-containing sealing material of the present invention is not particularly limited, but can be used for electronic members such as displays or printed boards, for example, and materials contained in these members such as elastomers, plastics, Applicable to metals, ceramics, etc. Examples of the electronic device including the electronic member include a personal computer, a tablet personal computer, a smart phone, a digital camera, and a car navigation system.

According to the composition for forming a fluorine-containing sealing material of the present invention, it is possible to form a fluorine-containing sealing material having water resistance and moisture resistance excellent in wear resistance. When hydrofluoroether is used as a solvent, a fluorine-containing sealing material having good waterproof and moisture resistance can be formed without causing chemical erosion and without adversely affecting the environment. Moreover, by using the composition for forming a fluorine-containing sealing material of the present invention, a fluorine-containing sealing material having good chemical resistance and a large film thickness can be formed. Furthermore, by using the composition for forming a fluorine-containing sealing material of the present invention, it is not necessary to separately provide an adhesive layer, and it becomes possible to adhere to the wall surface of a member or a gap, thereby simplifying the process of forming the fluorine-containing sealing material. Is possible.

Hereinafter, the treatment method using the composition for forming a fluorine-containing sealing material of the present invention will be described.

The treatment method is not particularly limited. For example, the composition for forming a fluorine-containing sealing material according to the present invention is used to form a void in an electronic member (for example, a bonded portion of a housing and a printed board, or a resin-molded metal terminal portion and a mold). It can be carried out by filling a gap between the resin and the like, and drying after filling.

Thereby, the hydroxyl group or hydrolyzable group bonded to the Si atom introduced into the polymer terminal or side chain of the fluorine-containing polymer contained in the composition for forming a fluorine-containing sealing material of the present invention is hydrolyzed by moisture in the atmosphere. Then, for example, the wall surface of the gap of the electronic member, or a member (for example, glass, metal wiring, or elastomer such as silicone, resin material such as polyethylene or epoxy) that is preliminarily filled in the gap, etc. It reacts with the object to be treated and improves the adhesion. Silanol groups that have not reacted with the wall surfaces of the voids or the above members are condensed to form a strong film by crosslinking two-dimensionally or three-dimensionally.

There is no particular limitation on the temperature during the treatment, and the treatment may be usually performed at room temperature. The treatment time is not particularly limited, and can be, for example, 5 minutes to 1 hour.

In addition, in order to form a fluorine-containing sealing material having higher wear resistance, in order to remove the oil on the wall surface of the gap prior to the treatment with the composition for forming a fluorine-containing sealing material of the present invention, It is preferable to dry after washing with acetone, hydrofluoroether or the like. Furthermore, in addition to the above cleaning, pretreatment with UV ozone, oxygen plasma or the like can further improve the wear resistance of the fluorine-containing sealing material.

Further, prior to the treatment with the composition for forming a fluorine-containing sealant of the present invention, it is formed from the composition for forming a fluorine-containing sealant by applying a primer treatment to the wall surfaces of the voids as necessary. The adhesion of the fluorine-containing sealant can be improved, and the wear resistance can be further improved. The primer treatment may be performed under the same conditions as the primer treatment in the case of using a silane coupling agent according to a conventional method.

The present invention will be described in more detail through the following examples, but the present invention is not limited to these examples.

In addition, the abbreviations of the compounds used in Examples and Comparative Examples are as follows.
Rf (C6) MA: Methacrylic acid (perfluorohexyl) ethyl (CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₆ F ₁₃ )
• MPS: mercaptopropyltrimethoxysilane • TMSMA: 3- (trimethoxysilyl) propyl methacrylate • IBMA: isobornyl methacrylate • CHMA: cyclohexyl methacrylate

<Synthesis Example 1>
In a four-necked flask equipped with a reflux tube, 50 g of Rf (C6) MA, 5 g of TMSMA, and 110 g of perfluorobutyl ethyl ether (HFE7200) were placed. The flask was heated to 80 ° C. with a nitrogen purge. Thereafter, 0.55 g of azoisobutyronitrile was added and reacted for 6 hours. The resulting reaction composition was designated as Compound 1.

(Evaluation of coating film)
Compound 1 was mixed with HFE7200 to prepare a solution containing 2% by mass of the polymer. This prepared solution was dipped on a slide glass (substrate) and dried at 25 ° C. for 24 hours to form a polymer coating film.

The obtained polymer coating film was subjected to water contact angle measurement for evaluation of repellency and cross-cut test for adhesion evaluation under the following conditions.

-Contact angle measurement of water The contact angle of the polymer coating film was measured 5 times using the contact angle measuring apparatus (made by Kyowa Interface Science Co., Ltd.), and the average value was computed.
Water droplet: 2 microliters Measurement temperature: 25 ° C

(GPC measurement)
The weight average molecular weight of the polymer contained in Compound 1 was measured under the following conditions. As a measurement sample, HFE7200 was added to Compound 1 and the polymer concentration was 1% by mass.
Eluent: Fluorine solvent [HCFC225 / hexafluoroisopropanol = 90/10 mass ratio]
Column: KF-806L (manufactured by Viscotek)
-Column temperature: 30 ° C
Measurement device: Gel permeation chromatography (manufactured by Viscotek)
・ Detector: Differential refractive index detector TDA-302 (manufactured by Viscotek)

-Cross cut test (cross cut method)
The test was carried out according to JIS K5600. Specifically, 5 × 5 squares were put in the polymer coating film using a cutter knife so that one square had a size of 2 mm in length and 2 mm in width. Cellotape (registered trademark) was pasted on the polymer coating film after the grids were formed, pressed with a finger, and then the cellotape was peeled off. The residual rate was calculated from the squares remaining on the substrate.

<Synthesis Example 2>
In a four-necked flask, 50 g of Rf (C6) MA, 0.1 g of MPS, and 100 g of HFE7200 were placed. The subsequent procedure was the same as in Synthesis Example 1. The resulting reaction composition was designated as Compound 2.

Compound 2 was subjected to GPC measurement in the same manner as in Synthesis Example 1. Moreover, the polymer coating film was formed and the coating film was evaluated similarly to the synthesis example 1.

<Synthesis Example 3>
A four-necked flask was charged with 50 g of Rf (C6) MA, 10 g of IBMA, 0.15 g of MPS, and 120 g of HFE7200. The subsequent procedure was the same as in Synthesis Example 1. The resulting reaction composition was designated as Compound 3.

Compound 3 was subjected to GPC measurement in the same manner as in Synthesis Example 1. Moreover, the polymer coating film was formed and the coating film was evaluated similarly to the synthesis example 1.

<Synthesis Example 4>
In a four-necked flask, 50 g of Rf (C6) MA, 7.5 g of CHMA, 2.5 g of TMSMA, and 120 g of HFE7200 were placed. The subsequent procedure was the same as in Synthesis Example 1. The resulting reaction composition was designated as Compound 4.

Compound 4 was subjected to GPC measurement in the same manner as in Synthesis Example 1. Moreover, the polymer coating film was formed and the coating film was evaluated similarly to the synthesis example 1.

<Synthesis Example 5>
In a four-necked flask, 50 g of Rf (C6) MA, 14 g of CHMA, and 115 g of HFE7200 were placed. The subsequent procedure was the same as in Synthesis Example 1. The resulting reaction composition was designated as Compound 5.

Compound 5 was subjected to GPC measurement in the same manner as in Synthesis Example 1. Moreover, the polymer coating film was formed and the coating film was evaluated similarly to the synthesis example 1.

<Examples 1 to 12 and Comparative Examples 1 to 14>
The reaction compositions obtained in Synthesis Examples 1 to 5 were adjusted in concentration using HFE7200, and solutions having polymer concentrations shown in Tables 1 and 2 were prepared. Evaluation of gap fill property and chemical resistance of each obtained sample was performed under the following conditions, respectively.

-Evaluation of gap fill property A copper plate having a thickness of 0.5 mm was sandwiched between two slide glasses to form a gap having a thickness of 0.5 mm and a depth of 2 mm. The solution was put into a syringe equipped with a needle having an outer diameter of 0.2 mm and poured into the gap. The gap fill property was evaluated as follows.
A: The solution enters the gap smoothly and spreads. Even if it does not bite bubbles or bites bubbles, the bubbles disappear naturally.
B: The solution enters the gap smoothly and spreads, but foaming occurs. If the sample is shaken immediately after injection, the bubbles disappear.
C: No solution enters the gap.

-Evaluation of chemical resistance The sample in which the solution was poured into the gap formed by the copper plate and the two slide glasses in the evaluation of the gap fill property was heated and cured at 25 ° C to form a cured product. This sample was sprayed with 100 ml of a 5% salt aqueous solution and allowed to stand for 24 hours. About the sample after stationary, the state of the copper plate was evaluated as follows.
A: There is no rust on the copper plate.
B: Rust is seen in a part of the entire copper plate (an area of about 10% when the area of the outer surface of the copper plate between the two glass slides and in contact with the cured product is 100%) .
C: Most of the copper plate (20 to 50% of the area) is rusted.
D: The entire area of the copper plate is rusted.

<Examples 15 to 23 and Comparative Examples 15 to 23>
The reaction composition (Compound 1) obtained in Synthesis Example 1 was converted into 1,2-dichloro-1,3,3,3-tetrafluoro-1-propene, 1,1-dichloro-2,3,3,3. Concentrations were adjusted using tetrafluoro-1-propene and 1-chloro-3,3,3-trifluoro-1-propene, respectively, and solutions having polymer concentrations shown in Table 3 were prepared. Evaluation of the gap fill property and chemical resistance of each obtained sample was implemented. Gap fill properties and chemical resistance were evaluated in the same manner as described above.

The present invention can be suitably used for forming a fluorine-containing sealing material for filling a gap between electronic members such as a display or a printed board (for example, a gap at the end face of a display) in an electronic device or the like.

Claims (14)

1. (I) Formula (1):
   

   

   [Where:
   Rf is a fluoroalkyl group;
   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 linear or branched group having 1 to 20 carbon atoms A branched alkyl group;
   Y is a direct bond or a divalent organic group. ]
   Is a polymer containing a structural unit derived from a fluoroalkyl group-containing (meth) acrylic acid ester represented by the following (A) and / or (B) fluorine-containing polymer (A) containing the fluoroalkyl group ( A fluorine-containing polymer comprising a component derived from a monomer component comprising a (meth) acrylate ester and a Si atom-containing polymerizable monomer,
   (B) a fluorine-containing polymer comprising a component derived from a Si atom-containing mercaptan and a component derived from a monomer component containing the fluoroalkyl group-containing (meth) acrylic acid ester,
   And (II) containing a fluorinated solvent,
   The Si atom-containing polymerizable monomer and the Si atom-containing mercaptan each independently contain at least one Si atom bonded to one or more hydroxyl groups or hydrolyzable groups,
   A composition for forming a fluorinated sealant, wherein the concentration of the fluorinated polymer is in the range of 7 to 33% by mass.
2. The composition for forming a fluorine-containing sealing material according to claim 1, wherein the viscosity is in the range of 10 to 1000 mPa · s.
3. 3. The composition for forming a fluorine-containing sealing material according to claim 1 or 2, wherein Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms.
4. Y represents a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom, and an oxygen atom. A cyclic aliphatic group having 6 to 10 carbon atoms which may have, an araliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, —CH ₂ CH ₂ N (R ¹ ) SO ₂ — A group (where R ¹ is an alkyl group having 1 to 4 carbon atoms), a —CH ₂ CH (OY ¹ ) CH ₂ — group (where Y ¹ is a hydrogen atom or an acetyl group), The composition for forming a fluorine-containing sealant according to any one of claims 1 to 3, which is a-(CH ₂ ) _n SO ₂ -group (n is 1 to 10).
5. The fluorine-containing sealing according to claim 3 or 4, wherein in the formula (1), Rf is a linear or branched fluoroalkyl group having 4 to 6 carbon atoms, and X is an atom or group other than hydrogen. Material forming composition.
6. The composition for forming a fluorine-containing sealing material according to any one of claims 1 to 5, wherein in the fluorine-containing polymer shown in (B), the monomer component further contains a Si atom-containing polymerizable monomer.
7. The Si atom-containing polymerizable monomer has the formula (2):
   

   

   [Where:
   R ² , R ³ and R ⁴ are the same or different and are a hydroxyl group, a hydrolyzable group or an alkyl group having 1 to 4 carbon atoms, provided that at least one of R ² , R ³ and R ⁴ is a hydroxyl group Or a hydrolyzable group;
   R ⁵ is a group containing a polymerizable unsaturated bond. ]
   The composition for forming a fluorine-containing sealant according to any one of claims 1 to 6, which is a compound represented by the formula:
8. The composition for forming a fluorine-containing sealant according to any one of claims 1 to 7, wherein the Si atom-containing mercaptan is a compound represented by the formula (3).
   

   

   [Where:
   R ⁷ , R ⁸ and R ⁹ are the same or different and are a hydroxyl group, a hydrolyzable group or an alkyl group having 1 to 4 carbon atoms, provided that at least one of R ⁷ , R ⁸ and R ⁹ is a hydroxyl group Or a hydrolyzable group;
   R ¹⁰ is a linear alkylene group having 1 to 12 carbon atoms. ]
9. The fluorine-containing polymer shown in (A) is represented by the following formula (5):
   

   

   [Where:
   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 linear or branched group having 1 to 20 carbon atoms A branched alkyl group;
   Y represents a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom, and an oxygen atom. A cyclic aliphatic group having 6 to 10 carbon atoms which may have, an araliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, —CH ₂ CH ₂ N (R ¹ ) SO ₂ — A group (where R ¹ is an alkyl group having 1 to 4 carbon atoms), a —CH ₂ CH (OY ¹ ) CH ₂ — group (where Y ¹ is a hydrogen atom or an acetyl group), Or — (CH ₂ ) _n SO ₂ — group (n is 1 to 10);
   Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms;
   R ² , R ³ and R ⁴ are the same or different and are an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, provided that at least one of R ² , R ³ and R ⁴ is An alkoxy group;
   R ^{5 ′} is a trivalent group derived from a group containing a polymerizable unsaturated bond;
   l and m are each an integer of 1 or more, and the sum of l and m is a numerical value with which the weight average molecular weight of the fluoropolymer is 3,000 to 500,000, where l and m are added. The order of presence of each repeating unit enclosed in parentheses is arbitrary in the formula. ]
   The composition for forming a fluorinated sealant according to any one of claims 1 to 8, which has a structural portion represented by the formula:
10. The fluorine-containing polymer shown in (B) is represented by the following formula (6):
    

    

    [Where:
    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 linear or branched group having 1 to 20 carbon atoms A branched alkyl group;
    Y represents a direct bond, an aliphatic group having 1 to 10 carbon atoms which may have an oxygen atom or a sulfur atom, an aromatic group having 6 to 10 carbon atoms which may have an oxygen atom, and an oxygen atom. A cyclic aliphatic group having 6 to 10 carbon atoms which may have, an araliphatic group having 6 to 10 carbon atoms which may have an oxygen atom, —CH ₂ CH ₂ N (R ¹ ) SO ₂ — A group (wherein R ¹ is an alkyl group having 1 to 4 carbon atoms), a —CH ₂ CH (OY ¹ ) CH ₂ — group (where Y ¹ is a hydrogen atom or an acetyl group), or — A (CH ₂ ) _n SO ₂ — group, where n is 1 to 10;
    Rf is a linear or branched fluoroalkyl group having 1 to 20 carbon atoms;
    R ⁷ , R ⁸ and R ⁹ are the same or different and are an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and at least one of R ⁷ , R ⁸ and R ⁹ is an alkoxy group. Is;
    R ¹⁰ is a linear alkylene group having 1 to 12 carbon atoms;
    k is a numerical value at which the weight average molecular weight of the fluoropolymer is 3,000 to 500,000. ]
    The composition for forming a fluorine-containing sealing material according to any one of claims 1 to 9.
11. The composition for forming a fluorine-containing sealing material according to any one of claims 1 to 10, wherein the fluorine-based solvent is at least one selected from the group consisting of hydrofluoroether, hydrofluorocarbon, and perfluorocarbon.
12. An article comprising a sealing material formed using the fluorine-containing sealing material-forming composition according to any one of claims 1 to 11.
13. The article according to claim 12, wherein the article is an electronic member.
14. The article according to claim 13, which is an electronic device including an electronic member.