JP2007161857A - Method for modifying substrate surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for modifying a substrate surface with which the modification having uniform and excellent persistence of the substrate surface can simply be carried out. <P>SOLUTION: The method for modifying the substrate surface is characterized as having the following steps. (1) a step of bringing the substrate surface treated by a physical method selected from a plasma treatment, a corona discharge treatment, a UV treatment and an electron beam treatment into contact with a high polymer having a polymerizable unsaturated double bond in the side chain and (2) a step of exposing the substrate to light, carrying out graft polymerization of the high polymer having the polymerizable unsaturated double bond in the side chain as radicals generated on the substrate surface by light exposure as starting points and producing a graft polymer directly bonded to the substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate surface modification method.

The application of the plasma process to polymer processing is widely known today, but the two most common techniques are plasma surface treatment and plasma polymerization. In the former, the surface of the polymer substrate is treated with a non-polymerizable gas such as nitrogen, argon, helium or the like as a plasma source. By this treatment, the surface of the polymer substrate has a polar group or a crosslinked structure. By being introduced, the hydrophilicity and adhesion of the surface can be improved. On the other hand, the latter is a method in which an organic gaseous monomer such as ethylene or benzene is converted into plasma and reacted, and an extremely thin film-like substance rich in a crosslinked structure can be obtained. This uses a specific function as a membrane, and can be applied as a separation membrane and a protective layer, and also can utilize the properties of the membrane surface.
That is, for example, the surface of a plasma polymerized film from a fluorine-based or silicon-based monomer is extremely hydrophobic, and the film from a nitrogen-containing monomer such as pyridine is hydrophilic. It can be used according to the purpose.
Both of the above-mentioned two methods are intended to perform modification processing and polymer film production by a one-step plasma process.

  By the way, at the time of the plasma surface treatment as described above, many polymer radicals are generated simultaneously with the introduction of polar groups and a crosslinked structure in the polymer substrate subjected to the treatment. Graft polymerization is possible with an organic monomer starting from this polymer radical. This plasma graft polymerization method has been known for a long time, and has been introduced for the purpose of, for example, hydrophilic processing of polyester. Further, plasma graft polymerization has an advantage that the surface modification can be easily performed in that the polymerization reaction proceeds without providing a separate polymerization initiation layer.

In such plasma graft polymerization, a reaction of a hydrophilic monomer in an aqueous solution is common. As a modified method, a method of reacting a monomer in a gas state has been proposed (see, for example, Patent Document 1 and Non-Patent Document 1 below). However, the methods described in these documents have a problem that, for example, it is extremely difficult to perform a uniform surface modification treatment on the surface of a large-area base material and the like, and the manufacturing suitability is poor.
Therefore, the present condition is that the method which can modify the base-material surface uniformly and simply has not been provided yet.
JP 52-98064 A Textile Industry, 91, 1975

  The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a substrate surface modification method that can easily perform uniform and excellent modification of the substrate surface.

  As a result of intensive studies, the present inventor performs plasma treatment or corona discharge treatment on the substrate surface, and uses a polymer compound having a polymerizable unsaturated double bond in the side chain on the substrate surface after the treatment. Thus, the inventors have found that the above object can be achieved by forming a graft polymer layer, and have completed the present invention.

That is, the substrate surface modification method of the present invention is (1) polymerizable unsaturated unsaturated on the substrate surface treated by a physical method selected from plasma treatment, corona discharge treatment, UV treatment, and electron beam treatment. A step of contacting a polymer having a double bond in a side chain (hereinafter also referred to as “step (1)” as appropriate), and (2) radicals generated on the substrate surface by exposure to the substrate and exposure. Is a step of graft polymerizing a polymer compound having a polymerizable unsaturated double bond in the side chain to form a graft polymer directly bonded to the substrate (hereinafter referred to as “step (2)” as appropriate). .).
The physical method in step (1) is preferably plasma treatment or corona discharge treatment.

  The substrate used in the substrate surface modification method of the present invention is preferably a substrate containing an organic polymer compound.

  ADVANTAGE OF THE INVENTION According to this invention, the base-material surface modification method which can perform the modification | reformation excellent in the uniformity and sustainability of the base-material surface easily can be provided.

The present invention will be described in detail below.
The substrate surface modification method of the present invention is a treatment by a physical method selected from plasma treatment, corona discharge treatment, UV treatment, and electron beam treatment (hereinafter sometimes referred to as “physical treatment” as appropriate). A polymer compound having a polymerizable unsaturated double bond in the side chain (hereinafter sometimes referred to as “graft precursor polymer” as appropriate) is brought into contact with the surface of the base material subjected to the treatment, and then (2) group A graft polymer obtained by subjecting the material to exposure, graft polymerization of a polymer compound having a polymerizable unsaturated double bond in the side chain from the radical generated on the surface of the base material by exposure, and binding directly to the base material It is implemented by generating.

The present invention is characterized in that in the step (1), the substrate is physically treated. By performing the physical treatment on the base material, for example, a graft polymer directly bonded to the base material is easily generated by graft polymerization without performing a process such as separately providing a polymerization initiation layer on the base material. be able to.
Furthermore, in the step (1), the graft precursor polymer is brought into contact with the surface of the base material after the physical treatment. Such contact in the step (1) is different from contacting the substrate with the monomer in the monomer aqueous solution having a low viscosity, and the graft precursor polymer can be uniformly present on the surface of the substrate. For this reason, when exposure is performed in the step (2), it is possible to obtain a substrate surface that has been uniformly modified by the graft polymer. Thus, it can be said that the method of the present invention is a method excellent in production suitability, which can easily obtain a substrate whose surface has been uniformly modified.

Hereinafter, the details of the substrate surface modification method of the present invention will be described in the order of steps.
First, step (1) will be described.
In the step (1), first, a base material to be surface-modified is processed by a physical method selected from plasma processing, corona discharge processing, UV processing, electron beam processing, etc. (physical processing). I do. That is, in the step (1), the surface of the base material is activated by performing a physical treatment on the base material. Other physical treatments include flame treatment, other treatments by irradiation with electromagnetic waves, and combined use of these treatments.

  The physical treatment applied to the step (1) is selected from plasma treatment, corona discharge treatment, UV treatment, and electron beam treatment, and as to which physical treatment is performed, depending on the material of the substrate. You can choose.

The physical treatment in the step (1) is performed on the surface of the substrate, and the degree of the treatment is such that the contact angle between the treated substrate surface and pure water is 50 from the viewpoint of graft polymerization starting point density. It is preferable to process so that it may become below 60 degree | times, and it is more preferable to process so that it may become below 40 degree | times.
In addition, the contact angle in this specification uses Kyowa Interface Science Co., Ltd. product, CA-Z, and calculates | requires the angle after 20 second after dripping of pure water.
Hereinafter, each physical process applied to this process is demonstrated in detail.

<Corona discharge treatment>
For the corona discharge treatment, a commercially available corona machine, for example, a solid state corona treatment machine manufactured by Pillar, a creating generator manufactured by SOFTAL, and a VETAPHONE high-frequency impulse surface treatment machine (for example, T-2000, T-4000) is used. Can be done.
The amount of treatment in the case of performing corona discharge treatment can be represented by energy per unit area (J / m ² ). The amount of treatment in the present invention is preferably in the range of 30 to 3000 J / m ² and particularly preferably in the range of 40 to 2000 J / m ² from the viewpoint of graft polymerization starting point density.
The amount of treatment in the case of performing the corona discharge treatment can be set according to the type of substrate.

<Plasma treatment>
The plasma treatment is performed by Toshiba Mechanics Co., Ltd. microplasma treatment equipment TMP-7048A, TMW-7407, TMZ-9602-A, IPC 200S high frequency plasma treatment equipment, and Yamato Scientific Co., Ltd. PR. -510, PDC210, etc.
The amount of treatment in the case of performing plasma treatment can be represented by energy per unit area (J / m ² ). The amount of processing in the present invention, from the viewpoint of the graft polymerization starting point density is preferably in the range of 30~3000J / ^{m 2,} the range of 40~2000J / ^{m 2} is particularly preferred.
The processing amount in the case of performing the plasma processing can be set according to the type of the substrate and the like.

<UV treatment>
The UV treatment can be performed using a light source such as an excimer laser, a high-pressure mercury lamp, or an arc lamp.
The processing amount in the case of performing the UV processing can be expressed by an etching amount in the depth direction. The amount of treatment in the present invention is preferably in the range of 10 to 100%, particularly preferably in the range of 30 to 70%, from the viewpoint of graft polymerization starting point density.
When performing the UV treatment, conditions for setting the processing amount such as the exposure energy, the exposure time, and the irradiation distance can be set according to the type of the substrate.

<Electron beam processing>
The electron beam treatment can be performed using a commercially available electron beam drawing apparatus such as HL750 manufactured by Hitachi, Ltd.
The processing amount in the case of performing electron beam processing can be expressed by acceleration voltage and electron flow. As the processing amount in the present invention, the acceleration voltage is preferably in the range of 10 kV to 300 kV, particularly preferably in the range of 20 kV to 200 kV. The electron current is preferably in the range of 5 to 500 mA, particularly preferably in the range of 10 to 300 mA.
The processing amount in the case of performing electron beam processing can be set according to the type of the substrate and the like.

  The physical method in step (1) is preferably plasma treatment or corona discharge treatment from the viewpoint of the amount of graft polymer produced and the ease of treatment.

<Base material>
The substrate that can be used in this step is not particularly limited, and may be an organic material, an inorganic material, or a hybrid material of organic and inorganic materials. The substrate in the present invention is preferably a substrate containing an organic polymer compound.

  Examples of the organic material constituting the substrate include acrylic resins such as polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4, 4 ′. -Polyester resin such as dicarboxylate, polybutylene terephthalate, etc., epoxy resin represented by commercial products such as Epicoat (trade name: manufactured by Yuka Shell Epoxy Co., Ltd.), polycarbonate resin, polyimide resin, novolac resin, phenol Resin etc. can be used suitably.

  Other organic materials include cellulose esters (eg, triacetylcellulose, diacetylcellulose, propionylcellulose, butyrylcellulose, acetylpropionylcellulose, nitrocellulose), polyamides, polystyrene (eg, syndiotactic polystyrene), polyolefins ( Examples include polypropylene, polyethylene, polymethylpentene), polysulfone, polyethersulfone, polyarylate, polyetherimide, and polyetherketone.

  The thickness of the substrate is selected according to the purpose of use and is not particularly limited, but is generally about 10 μm to 10 cm.

  In step (1), after the physical treatment performed on the base material, the surface of the base material is contacted with a polymer compound (graft precursor polymer) having a polymerizable unsaturated double bond in the side chain. . Hereinafter, the graft precursor polymer in the present invention will be described.

<Graft precursor polymer>
As the graft precursor polymer applicable to the present invention, a polymer compound having a functional group capable of achieving the target surface modification and a polymerizable unsaturated double bond in the side chain may be used.
For example, if a hydrophilic surface is to be obtained, a polymer compound having a hydrophilic group and a polymerizable unsaturated double bond in the side chain may be used, and if a hydrophobic surface is to be obtained, hydrophobic A polymer compound having a group and a polymerizable unsaturated double bond in the side chain may be used.
For example, if a functional surface such as a water / oil repellent surface is to be obtained, a polymer compound having an oil repellent and water repellent functional group and a polymerizable unsaturated double bond in the side chain may be used. Good. However, the present invention is not limited to these.

  Hereinafter, as specific examples of the graft precursor polymer, the above-mentioned “polymer compound having a hydrophilic group and a polymerizable unsaturated double bond in the side chain” and “oil-repellent and water-repellent functional groups and polymerizable unsaturated compounds”. The “polymer compound having a double bond in the side chain” will be described.

<High molecular compound having a hydrophilic group and a polymerizable unsaturated double bond in the side chain>
The polymer compound having a hydrophilic group and a polymerizable unsaturated double bond in the side chain is an ethylene addition polymerizable unsaturated group such as vinyl group, allyl group or (meth) acryl group introduced into the molecule. It refers to a hydrophilic polymer containing a radical polymerizable group.
This radically polymerizable group-containing hydrophilic polymer is required to have a polymerizable group in the side chain. Hereinafter, the hydrophilic polymer having a polymerizable group in the side chain will be referred to as a radically polymerizable group-containing hydrophilic polymer.

Such a radically polymerizable group-containing hydrophilic polymer can be synthesized as follows.
As a synthesis method, (a) a method of copolymerizing a hydrophilic monomer and a monomer having an ethylene addition polymerizable unsaturated group, (b) copolymerizing a hydrophilic monomer and a monomer having a double bond precursor, Next, a method of introducing a double bond by treatment with a base or the like, and (c) a method of reacting a functional group of a hydrophilic polymer with a monomer having an ethylene addition polymerizable unsaturated group. Among these, from the viewpoint of synthesis suitability, (c) a method of reacting a functional group of a hydrophilic polymer with a monomer having an ethylene addition polymerizable unsaturated group is particularly preferable.

In the methods (a) and (b), the hydrophilic monomer used for the synthesis of the radical polymerizable group-containing hydrophilic polymer includes (meth) acrylic acid or its alkali metal salt and amine salt, itaconic acid or its alkali. Metal salt and amine salt, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-monomethylol (meth) acrylamide, N-dimethylol (meth) acrylamide, allylamine or its hydrohalide, 3-vinylpropion Acid or alkali metal salt and amine salt thereof, vinyl sulfonic acid or alkali metal salt and amine salt thereof, 2-sulfoethyl (meth) acrylate, polyoxyethylene glycol mono (meth) acrylate, 2-acrylamido-2-methylpropanesulfone Monomers having hydrophilic groups such as carboxyl groups, sulfonic acid groups, phosphoric acid groups, amino groups or salts thereof, hydroxyl groups, amide groups and ether groups, such as acid phosphooxypolyoxyethylene glycol mono (meth) acrylate Can be mentioned.
As the hydrophilic polymer used in the method (c), a hydrophilic homopolymer or copolymer obtained using at least one selected from these hydrophilic monomers is used.

  When the radically polymerizable group-containing hydrophilic polymer is synthesized by the method (a), examples of the monomer having an ethylene addition polymerizable unsaturated group that is copolymerized with the hydrophilic monomer include an allyl group-containing monomer. Examples include allyl (meth) acrylate and 2-allyloxyethyl methacrylate.

  Further, when the radical polymerizable group-containing hydrophilic polymer is synthesized by the method (b), a monomer having a double bond precursor that is copolymerized with a hydrophilic monomer is 2- (3-chloro-1-oxopropoxy). ) Ethyl methacrylate.

  Further, when the radical polymerizable group-containing hydrophilic polymer is synthesized by the method (c), a reaction between a carboxyl group, an amino group or a salt thereof in the hydrophilic polymer and a functional group such as a hydroxyl group and an epoxy group is performed. It is preferable to introduce an unsaturated group using it. Examples of the monomer having an addition polymerizable unsaturated group used for this purpose include (meth) acrylic acid, glycidyl (meth) acrylate, allyl glycidyl ether, and 2-isocyanatoethyl (meth) acrylate.

-Hydrophilic macromonomer-
The polymer compound in the present invention includes a macromonomer. In the present invention, a macromonomer having a molecular weight of 100 to 100,000 can be used.
The method for producing a macromonomer that can be used in the present invention is described in, for example, Chapter 2 of “Macromonomer Chemistry and Industry” (Editor, Yuya Yamashita) published on September 20, 1999 by the IP Publishing Bureau. Various production methods have been proposed in “Synthesis”.
Particularly useful hydrophilic macromonomers that can be used in the present invention include macromonomers derived from carboxy group-containing monomers such as acrylic acid and methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, and vinylsterene sulfone. Sulfonic acid macromonomer derived from monomer of acid and its salt, (meth) acrylamide, N-vinylacetamide, N-vinylformamide, amide macromonomer derived from N-vinylcarboxylic amide monomer, hydroxyethyl Macromonomers derived from hydroxyl group-containing monomers such as methacrylic acid, hydroxyethyl acrylate, glycerol monomethacrylate, methoxyethyl acrylate, methoxypolyethylene glycol acrylate, polyethylene glycol Macromonomers derived from alkoxy group or ethylene oxide group-containing monomers such Lumpur acrylate. A monomer having a polyethylene glycol chain or a polypropylene glycol chain can also be usefully used as the macromonomer of the present invention.

<Polymer compound having oil- and water-repellent functional groups and polymerizable unsaturated double bond in side chain>
A polymer compound having an oil-repellent and water-repellent functional group and a polymerizable unsaturated double bond in the side chain has a water-repellent / oil-repellent functional group in the molecule that gives the surface water-repellent / oil-repellent properties. It is a radically polymerizable polymer compound.
Using such a polymer compound having an oil-repellent and water-repellent functional group and a polymerizable unsaturated double bond in the side chain is more effective than using a low-molecular compound having an oil-repellent and water-repellent functional group. Thus, the surface of the base material can be modified with improved surface water repellency effect of the obtained water / oil repellent material.

The specific oil-repellent polymer containing a radical polymerizable group can be synthesized as follows.
(I) a method of copolymerizing a water / oil repellent monomer such as a fluorine monomer and a monomer having an ethylene addition polymerizable unsaturated group; (ii) a monomer having a water / oil repellent monomer and a double bond precursor; Next, a method of introducing a double bond by treatment with a base, etc., (iii) a water / oil repellent polymer having a functional group such as carboxylic acid and a compound having an ethylene addition polymerizable unsaturated group And the like. Among these, from the viewpoint of synthesis suitability, (iii) a method of reacting a functional group of a water / oil repellent polymer with a monomer having an ethylene addition polymerizable unsaturated group is particularly preferable.

When the radically polymerizable group-containing oil-repellent polymer is synthesized by the method (i), examples of the monomer having an ethylene addition polymerizable unsaturated group that is copolymerized with the oil-repellent monomer include an allyl group-containing monomer. Examples include allyl (meth) acrylate and 2-allyloxyethyl methacrylate.
In addition, when synthesizing the radically polymerizable group-containing oil-repellent polymer by the method (ii), a monomer having a double bond precursor that is copolymerized with the oil-repellent monomer includes 2- (3-chloro-1-oxopropoxy ) Ethyl methacrylate.
Furthermore, when the radically polymerizable group-containing oil-repellent polymer is synthesized by the method (iii), the reaction between the carboxyl group, amino group or salt thereof in the oil-repellent polymer and a functional group such as a hydroxyl group and an epoxy group is performed. Monomers having an addition-polymerizable unsaturated group used for introducing unsaturated groups using (meth) acrylic acid, glycidyl (meth) acrylate, allyl glycidyl ether, 2-isocyanatoethyl (meth) acrylate Etc.

Here, examples of the monomer having an oil repellent and water repellent functional group used for synthesizing a specific oil repellent polymer include a fluorine monomer and a silicon-based (silicon-based) monomer.
(Fluorine-containing monomer)
The fluorine-containing monomer used as a raw material for the specific oil-repellent polymer used for the formation of the graft polymer layer is selected from the group consisting of the following general formulas (I), (II), (III), (IV) and (V). And at least one selected fluorine-containing monomer.
CH ₂ = CR ¹ COOR ² R ^f (I)
[Wherein, R ¹ is a hydrogen atom or a methyl group, R ² is —C _p H _2p —, —C (C _p H _{2p + 1} ) H—, —CH ₂ C (C _p H _{2p + 1} ) H— or -CH ₂ CH ₂ O-, the ^{_{R f -C n F 2n + 1}} , - (CF 2) n H, -C n F 2n -CF 3, - (CF 2) p OC n H 2n C i F _{2i + 1, - (CF 2} ) p OC m H 2m C i F 2i H, -N (C p H 2p + 1) COC n F 2n + 1, -N (C p H 2p + 1) SO 2 C _n F _{2n + 1} . However, p is 1-10, n is 1-16, m is 0-10, i is an integer of 0-16. ]

CF ₂ = CFOR ^g (II)
(In the formula, R ^g represents a fluoroalkyl group having 1 to 20 carbon atoms.)
CH ₂ = CHR ^g (III)
(In the formula, R ^g represents a fluoroalkyl group having 1 to 20 carbon atoms.)
^{_{CH 2 = CR 3 COOR 5 R}} j R 6 OCOCR 4 = CH 2 ··· (IV)
[Wherein R ³ and R ⁴ are hydrogen atoms or methyl groups, R ⁵ and R ⁶ are —C _q H _2q −, —C (C _q H _{2q + 1} ) H—, —CH ₂ C (C _q H _2q + 1) H- or -CH ₂ CH ₂ O-, R ^j is -C _t F _2t. However, q is an integer of 1 to 10, and t is an integer of 1 to 16. ]
CH ₂ = CHR ⁷ COOCH ₂ (CH ₂ R ^k ) CHOCOCR ⁸ = CH ₂ (V)
(Wherein R ⁷ and R ⁸ are a hydrogen atom or a methyl group, R ^k is —C _y F _{2y + 1} , where y is an integer of ₁ to 16)

Hereinafter, although the specific example of the fluorine-containing monomer which can be used for this invention is given, this invention is not restrict | limited to this.
Examples of the monomer represented by the general formula (I) include CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ OCOCH═CH ₂ , CF ₃ CH ₂ OCOCH═CH ₂ , CF ₃ (CF ₂ ) ₄ CH ₂ CH _2. OCOC (CH ₃ ) = CH ₂ , C ₇ F ₁₅ CON (C ₂ H ₅ ) CH ₂ OCOC (CH ₃ ) = CH ₂ , CF ₃ (CF ₂ ) ₇ SO ₂ N (CH ₃ ) CH ₂ CH ₂ OCOCH ═CH ₂ , CF ₃ (CF ₂ ) ₇ SO ₂ N (C ₃ H ₇ ) CH ₂ CH ₂ OCOCH═CH ₂ , C ₂ F ₅ SO ₂ N (C ₃ H ₇ ) CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , (CF ₃ ) ₂ CF (CF ₂ ) ₆ (CH ₂ ) ₃ OCOCH═CH ₂ , (CF ₃ ) ₂ CF (CF ₂ ) ₁₀ (CH ₂ ) ₃ OCOC (CH ₃ ) = CH _{2 , CF 3 (CF 2) 4} CH (CH 3) OCOC (CH 3) = CH 2, CF 3 CH 2 OCH 2 C _{2 OCOCH = CH 2, C 2} F 5 (CH 2 CH 2 O) 2 CH 2 OCOCH = CH 2, (CF 3) 2 CFO (CH 2) 5 OCOCH = CH 2, CF 3 (CF 2) 4 OCH 2 _{CH 2 OCOC (CH 3) =} CH 2, C 2 F 5 CON (C 2 H 5) CH 2 OCOCH = CH 2, CF 3 (CF 2) 2 CON (CH 3) CH (CH 3) CH 2 OCOCH = _{CH 2, H (CF 2)} 6 C (C 2 H 5) OCOC (CH 3) = CH 2, H (CF 2) 8 CH 2 OCOCH = CH 2, H (CF 2) 4 CH 2 OCOCH = CH 2 H (CF ₂ ) CH ₂ OCOC (CH ₃ ) ═CH ₂ , CF ₃ (CF ₂ ) ₇ SO ₂ N (CH ₃ ) CH ₂ CH ₂ OCOC (CH ₃ ) ═CH ₂ , CF ₃ (CF ₂ ) _{7 SO 2 N (CH 3)} (CH 2) 10 OCOCH = CH 2, C 2 F 5 SO 2 N (C 2 H 5 _{CH 2 CH 2 OCOC (CH 3} ) = CH 2, CF 3 (CF 2) 7 SO 2 N (CH 3) (CH 2) 4 OCOCH = CH 2, C 2 F 5 SO 2 N (C 2 H 5) _{C (C 2 H 5) HCH} 2 OCOCH = CH 2 and the like.

Examples of the fluoroalkylated olefin represented by the general formulas (II) and (III) include C ₃ F ₇ CH═CH ₂ , C ₄ F ₉ CH═CH ₂ , C ₁₀ F ₂₁ CH═CH ₂ , C such as _{3 F 7 OCF = CF 2,} C 7 F 15 OCF = CF 2 and C ₈ F ₁₇ OCF = CF ₂ and the like.

The monomer represented by the general formula (IV) and (V) for _{example, CH 2 = CHCOOCH 2 (CF} 2) 3 CH 2 OCOCH = CH 2, CH 2 = CHCOOCH 2 CH (CH 2 C 8 F 17) OCOCH = CH _{2 and the} like can be mentioned.

As a monomer that can be used for the synthesis of the specific oil-repellent polymer used for the formation of the graft polymer layer, in addition to the above-mentioned fluorine-containing monomer, a monomer having no fluorine can be used in combination as long as the effects of the present invention are not impaired. . Such monomers are not particularly limited as long as they can be radically polymerized, and specifically, unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, and alkyl or glycidyl thereof. Examples include esters, styrene, vinyl esters of alkyl acids, and silicon-containing monomers.
The blending amount when used in combination is preferably 50% by weight or less based on the fluorine-containing monomer.

(Silicon monomer)
Examples of the silicon-based monomer that can be used as a raw material for the specific oil-repellent polymer in the present invention include silicon-based monomers having a Si—CH ₃ group or —O—Si—CH ₃ group. Specifically, a silicon acrylate or silicone methacrylate, the general formula _{(CH 3 O) n Si (} CH 3) 3-n -R 3 -O-CO-CR 4 = are those represented by CH _2, R ³ is a linking group, and R ⁴ is methyl or hydrogen. In addition, for example, a silicon-based monomer described in paragraph No. [0025] of JP-A-2003-335984 can also be mentioned as a preferable example.

(Other monomers)
The polymer compound having an oil-repellent and water-repellent functional group and a polymerizable unsaturated double bond in the side chain of the present invention includes, in addition to the oil-repellent and water-repellent group, and the polymerizable unsaturated double bond group as constituent elements. In addition, other monomers may be copolymerized. These monomers are used to increase the solvent solubility of the polymer compound of the present invention. Although it does not specifically limit as a monomer used for such a purpose, Acrylic acid ester, such as (meth) acrylic acid methyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid methoxyethyl ester, is used. be able to.

  Examples of polymer compounds having the oil- and water-repellent functional groups and polymerizable unsaturated double bonds in the side chain that can be used in the present invention [Exemplary Compounds (1) to (11)] are shown below. However, the present invention is not limited to these.

  The molecular weight of the polymer compound having an oil and water repellent functional group and a polymerizable unsaturated double bond in the side chain is in the range of 1,000 to 1,000,000, and particularly preferably in the range of 5,000 to 100,000. By using a specific oil-repellent polymer in this molecular weight range, excellent water and oil repellency is realized, and the solvent is excellent in solubility when being brought into contact with the substrate surface, and the handleability is also good.

  In the step (1), the solvent / dispersion medium used in the coating liquid / dispersion liquid containing the graft precursor polymer is not particularly limited as long as the graft precursor polymer and additives added as necessary are soluble. Absent.

For example, when a hydrophilic polymer compound is applied as the graft precursor polymer, the solvent / dispersion medium used in the coating liquid / dispersion liquid is preferably an aqueous solvent such as water or a water-soluble solvent. Of these, a mixture of a surfactant and a solvent is preferred. The water-soluble solvent refers to a solvent miscible with water in an arbitrary ratio, and examples of such a water-soluble solvent include alcohol solvents such as methanol, ethanol, propanol, ethylene glycol, and glycerin, acids such as acetic acid, Examples thereof include ketone solvents such as acetone, amide solvents such as formamide, and the like.
In the case where a hydrophobic polymer compound is applied as the graft precursor polymer, the solvent / dispersion medium used in the coating solution / dispersion liquid is methanol, ethanol, 1-methoxy-2-propanol, or the like. Alcohol solvents, ketone solvents such as methyl ethyl ketone, hydrocarbon solvents such as toluene are preferred.
Further, when a specific oil-repellent polymer is applied as the graft precursor polymer, the solvent / dispersion medium used in the coating liquid / dispersion liquid includes ketone solvents such as acetone, ester solvents such as ethyl acetate, Examples include alcohol solvents such as 1-methoxy-2-propanol, and other fluorine-based solvents such as hexafluoropropanol.

  At this time, the concentration of the graft precursor polymer in the coating liquid / dispersion liquid varies depending on the polymer used, but is preferably 1 to 80% by mass, and more preferably 5 to 50% by mass.

  In the step (1), as a method of bringing the graft precursor polymer into contact with the substrate surface, a method in which a solution or dispersion in which the graft precursor polymer is dissolved is applied to the substrate, a solution or a dispersed dispersion A method of immersing the base material in the substrate is preferable, and from the viewpoint of film thickness uniformity of the polymer layer, a method of applying a solution or dispersion of the graft precursor polymer to the base material is preferable.

  Next, (2) a step of exposing the base material and graft-polymerizing the graft precursor polymer from the radical generated on the surface of the base material by the exposure to generate a graft polymer directly bonded to the base material (step) (2)) will be described.

  In the step (2), after the physical treatment is performed on the base material, the base material is exposed in a state where the graft precursor polymer is applied or immersed on the surface of the base material. Based on the starting point generated in the material, the graft precursor polymer is directly bonded to the substrate by graft polymerization to form a graft polymer.

The substrate on which the graft polymer is formed on the surface of the substrate by the method of the present invention is subjected to a treatment such as solvent immersion after the exposure, and the special polymerizable unsaturated double bond remaining without being subjected to graft polymerization. The polymer compound in the side chain is removed and purified. Specifically, washing with water or acetone, drying, and the like can be given.
From the standpoint of residual polymer removability, it is preferable to adopt means such as ultrasonic waves during washing. The base material after purification is such that the polymer remaining on the surface is completely removed, and only the polymer compound having a polymerizable unsaturated double bond firmly bonded to the base material in the side chain is present.

In particular, when the present invention is applied to a durable antifouling surface material, a coating solution containing a polyfunctional acrylate and a photopolymerization initiator is applied on a substrate and cured by light irradiation. An intermediate layer is formed, and the specific oil-repellent polymer is brought into contact with the intermediate layer by a method such as coating, and then the step (2), that is, the active energy ray is irradiated to perform photografting polymerization on the substrate surface. It is preferable to carry out the step of causing it.
In other words, when an application liquid containing a polyfunctional acrylate and a photopolymerization initiator is applied, and irradiated with light and cured to form a hard coat, the intermediate layer is irradiated with active energy rays such as UV exposure. Polymerization starts from the remaining initiator, and a polymerization terminal is generated in the polyfunctional acrylate. A specific oil-repellent polymer is fixed by graft polymerization with the polymerization terminal as a starting point, whereby a layer containing a fluoropolymer is formed on a strong intermediate layer having a crosslinked structure. Therefore, the resulting fluorine-containing polymer coating has a two-layer structure in which a fluorine polymer layer composed of a graft polymer chain made from a fluorine-containing monomer bonded to the intermediate layer surface via a polyfunctional acrylate as a raw material is formed. Have.

  In this two-layer structure, the intermediate layer formed on the surface of the base material is in close contact with the base material as a hard coat layer having a crosslinked structure, and the intermediate layer itself has a high hardness, and is also a coating made of a specific oil repellent polymer. That is, since the graft polymer layer having a water / oil repellent functional group is fixed by chemical bonding with the material constituting the intermediate layer, the water / oil repellent material obtained by the method of the present invention is used. When used as an antifouling surface material, it is excellent in hardness and adhesion, and high antifouling property due to a specific oil-repellent polymer such as a fluoropolymer will last for a long time.

In the step (2), the active energy ray used for the exposure for causing the graft polymerization reaction is such that the photopolymerization initiation site remaining on the surface of the substrate can absorb the energy and generate an active site. Although there is no particular limitation, specifically, ultraviolet rays and visible rays having a wavelength of 200 to 800 nm, preferably 300 to 600 nm are desirable.
Examples of the exposure light source include a high-pressure mercury lamp, a low-pressure mercury lamp, a halogen lamp, a xenon lamp, an excimer laser, a dye laser, a YAG laser, and sunlight.
The exposure energy is preferably about 10 mJ / m ^{3 to} 10,000 J / m ³ .

  The present invention can be applied in various ways depending on the surface modification mode. For example, in addition to the water- and oil-repellent materials described above, antifouling films, cloud-proof films, gas barrier films, conductive films and the like can be mentioned.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[Example 1-1]
[(1) Process]
<Plasma treatment>
A 75 μm thick polyethylene terephthalate film substrate was subjected to plasma treatment using PDC-510 manufactured by Yamato Scientific Co., Ltd. under an argon atmosphere, output 50 J / m ² , vacuum degree 11 to 12 Pa, gap between electrodes 150 mm, room temperature, A substrate a was obtained.

<Graft precursor polymer solution coating>
The following hydrophilic polymer P-1 (0.6 g) as a graft precursor polymer is dissolved in a mixed solution of 5.0 g of pure water and 3.0 g of acetonitrile to prepare a graft precursor polymer solution (a coating solution for a graft forming layer). did. The obtained coating liquid for graft formation layers was apply | coated to the base material a with the spin coater. The spin coater was first rotated at 300 rpm for 5 seconds and then at 1000 rpm for 20 seconds. The base material a after applying the coating solution for the graft forming layer was dried at 100 ° C. for 2 minutes.

-Hydrophilic polymer P-1-
18 g of polyacrylic acid (average molecular weight 25,000) is dissolved in 300 g of dimethylacetamide (DMAC), and 0.41 g of hydroquinone, 19.4 g of 2-methacryloyloxyethyl isocyanate, 0.25 g of dibutyltin dilaurate, , And reacted at 65 ° C. for 4 hours. The acid value of the obtained polymer was 7.02 meq / g. Thereafter, the carboxyl group was neutralized with a 1 mol / l (1N) aqueous sodium hydroxide solution, ethyl acetate was added to precipitate the polymer, washed well, and hydrophilic polymer P-1 having a polymerizable group in the side chain was obtained. 18.4 g was obtained.

[(2) Process]
<UV exposure>
The surface of the substrate A coated with the graft forming layer was exposed for 1 minute with an exposure machine (UVX-02516S1LP01, manufactured by USHIO INC.). After the exposure, it was thoroughly washed with pure water.
As described above, a base material A-1 whose surface was modified to be hydrophilic was obtained.

  The obtained base material A-1 was cut using a microtome, and the cut cross section was observed with an SEM. As a result, it was confirmed that the graft polymer layer was formed on the surface with a film thickness of about 1 μm.

[Examples 1-2 to 1-5]
Steps (1) and (2) were carried out in the same manner as in Example 1-1 except that the output of the plasma processing apparatus used in step (1) of Example 1-1 was changed as shown in Table 1. The substrate A-2 to A-5 whose surface was modified to be hydrophilic was obtained.

[Comparative Example 1-1]
A substrate A-6 was obtained in the same manner as in Example 1-1 except that in the step (1) of Example 1-1, the polyethylene terephthalate film was not subjected to plasma treatment.

[Comparative Example 1-2]
Substrate A-7 was prepared in the same manner as in Example 1-1 except that the application of the graft precursor polymer solution in step (1) of Example 1-1 and the UV exposure in step (2) were not performed. Got.

[Comparative Example 1-3]
The base material a obtained in the step (1) of Example 1-1 was immersed in an aqueous acrylic acid solution (10% by mass) for 1 minute using an exposure machine (UVX-02516S1LP01, manufactured by Ushio Inc.). Exposed. After the exposure, the film was sufficiently washed with pure water, immersed in saturated aqueous sodium hydrogen carbonate for 5 minutes, and thoroughly washed with pure water again. As a result, a base material A-8 whose surface was modified to be hydrophilic was obtained.

[Example 2-1]
[(1) Process]
<Corona discharge treatment>
A polyethylene terephthalate film substrate having a thickness of 75 μm was subjected to corona discharge treatment at a power of 20 W, a line speed of 50 m / min, and room temperature using a solid state corona treatment machine manufactured by Pillar to obtain a substrate b.

<Graft precursor polymer solution coating>
The same coating liquid for graft forming layer as that used in Example 1-1 was applied to the substrate b with a spin coater. The spin coater was first rotated at 300 rpm for 5 seconds and then at 1000 rpm for 20 seconds. The base material b after applying the coating solution for the graft forming layer was dried at 100 ° C. for 2 minutes.

[(2) Process]
<UV exposure>
The surface of the substrate b to which the graft forming layer was applied was exposed for 1 minute with an exposure machine (UVX-02516S1LP01, manufactured by USHIO INC.). After exposure, it was pure and thoroughly washed.
As described above, the base material B-1 whose surface was modified to be hydrophilic was obtained.

  The obtained base material B-1 was cut using a microtome, and the cut cross section was observed with an SEM. As a result, it was confirmed that the graft polymer layer was formed on the surface with a film thickness of about 1 μm.

[Examples 2-2 to 2-5]
Steps (1) and (2) were performed in the same manner as in Example 2-1, except that the output of the corona discharge treatment apparatus used in Step (1) of Example 2-1 was changed as shown in Table 2. And base materials B-2 to B-5 whose surfaces were modified to be hydrophilic were obtained.
It was.

[Comparative Example 2-1]
A substrate B-6 was obtained in the same manner as in Example 2-1, except that the corona discharge treatment of the polyethylene terephthalate film substrate was not performed in the step (1) of Example 2-1.

[Example 3-1]
In the step (1) of Example 2-1, the hydrophilic polymer (P-1) used in the graft precursor polymer solution was changed to the hydrophobic polymer P-2 shown below in the same manner (step ( 1) and step (2) were performed to obtain a substrate C-1 whose surface was modified to be hydrophobic.

-Hydrophobic polymer (P-2)-
The hydrophobic polymer P-2 is synthesized through the following two steps.
<Step 1: Synthesis of 2- (perfluorooctyl) -ethyl methacrylate (FAMAC) and methacrylic acid 2-hydroxyethyl ester (HEMA) (FAMAC / HEMA = 33/67)>
Under a nitrogen atmosphere, 30 g of N, N-dimethylacetamide (DMAc, Wako Pure Chemical Industries) was placed in a 300 ml three-necked flask equipped with a condenser and heated to 65 ° C. in a water bath. Here, DMAc 30 g, methacrylic acid 2-hydroxyethyl ester (HEMA, Tokyo Chemical Industry Co., Ltd.) 5.0 g (0.0382 mol) and 2- (perfluorooctyl) -ethyl methacrylate (FAMAC, manufactured by Daikin Fine Chemical Laboratories) 10.0 g (0.0188 mol) and 2.2'-azobis (isobutyric acid) (V601, Wako Pure Chemical Industries, Ltd.) 0.66 g (0.0029 mol) was dissolved in a homogeneous solution with a plunger pump at 0.54 ml / min. It was dripped at a speed. After completion of the dropwise addition, the reaction was stopped by stirring for 5 hours.
The reaction solution was reprecipitated with 1500 ml of methanol, and the precipitated solid was collected by suction filtration. Vacuum drying for 3 hours gave a white powder. (Yield 6.52 g, 43% yield)
IR (KBr) (measured using Excalibur FTIR-8300 (SHIMAZU))
3471 (b), 2953 (b), 1732 (s), 1456 (s) cm ^-1

<Step 2: Introduction of double bond to copolymer>
3.0 g of the copolymer obtained in Step 1 and 0.0325 g of hydroquinone (Wako Pure Chemical Industries, Ltd.) were placed in a 300 ml three-necked flask equipped with a cooling tube, and 40 g of DMAc was added and stirred at room temperature to obtain a uniform solution.
While stirring the solution, 1.53 g (0.00983 mol) of 2-methacryloyloxyethyl isocyanate (Karenz MOI, Showa Denko) was added dropwise. Subsequently, 1 drop of dilauric acid di-n-butyltin (Tokyo Kasei Kogyo) was added and heated in a 65 ° C. water bath with stirring. After 5 hours, the reaction was stopped and the mixture was naturally cooled to room temperature. The reaction solution was reprecipitated with 1500 ml of methanol, and the precipitated solid was collected by suction filtration to obtain a hydrophobic polymer P-2. (Yield 2.5g, Yield 55%)
IR (KBr) (measured using Excalibur FTIR-8300 (SHIMAZU))
3390 (b), 2961 (b), 1732 (s), 1639 (s) cm ⁻¹
The molecular weight (GPC, THF, polystyrene conversion) was Mw30500.

[Examples 3-1 to 3-5]
Steps (1) and (2) were performed in the same manner as in Example 3-1, except that the output of the corona discharge treatment apparatus used in Step (1) of Example 3-1 was changed as shown in Table 3. To obtain substrates C-2 to C-5 whose surfaces were modified to be hydrophobic.

[Comparative Example 3-1]
In step (1) of Example 3-1, a base material C-6 was obtained in the same manner as in Example 3-1, except that the polyethylene terephthalate film base material was not subjected to corona discharge treatment.

<Evaluation>
About the base material which processed each Example and the comparative example, the wettability test of the base-material surface was done and evaluated.
Moreover, about the base material (hydrophilic surface base material) obtained in Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-2, a dyeing test is performed to evaluate the uniformity of the surface modification. did.
Details of each evaluation test are as follows.

1. Wetability test About the base materials A-1 to A-8, B-1 to B-5, and C-1 to C-5 which have passed one day after the base material surface modification treatment, manufactured by Kyowa Interface Science Co., Ltd., CA Using -Z, the angle 20 seconds after the addition of pure water was measured. The measured value was an average value of five measurements. Moreover, it measured similarly about the contact angle with respect to the pure water of each base-material surface which passed for 30 days at room temperature. The results are shown in Tables 1 to 3 below.

2. Dyeing test The substrates A-1 to A-8 were immersed in an aqueous methylene blue solution (1% by mass) for 5 minutes, and the dyeing uniformity was visually evaluated. Shown in Table 1 below

As shown in Tables 1 to 3, the base materials A-1 to A-5, B-1 to B-5, and C- It can be seen that the surfaces of 1 to C-5 are each modified to the desired hydrophilic or hydrophobic surface. Moreover, the base material surface-modified by this invention is maintaining the modification | reformation effect even 30 days after a modification process, and it turns out that the base-material surface modification by this invention is excellent in sustainability. .
In addition, as shown in the dyeing test results of Table 1, it can be seen that the surface modifications of the substrates A-1 to A-5 that were surface-modified according to the present invention were uniform. On the other hand, the base material A-6 that did not perform the step (1) and the base material A-7 that did not perform the step (2) were not surface-modified, and the graft precursor in the step (2) It can be seen that the base material A-8 obtained using the monomer without using the polymer is a non-uniform modification although the surface of the base material is modified.

Claims (4)

  (1) A polymer compound having a polymerizable unsaturated double bond in a side chain is brought into contact with a substrate surface treated by a physical method selected from plasma treatment, corona discharge treatment, UV treatment, and electron beam treatment. And (2) exposing the substrate, grafting a polymer compound having a polymerizable unsaturated double bond in the side chain from the radical generated on the substrate surface by the exposure, And a step of producing a graft polymer directly bonded to the substrate.   The substrate surface modification method according to claim 1, wherein the physical method is plasma treatment or corona discharge treatment.   The substrate surface modification method according to claim 1, wherein the substrate is a substrate containing an organic polymer compound. The contact of the polymer compound having the polymerizable unsaturated double bond in the side chain with the substrate is performed by applying a solution or dispersion of the polymer compound to the substrate surface. The substrate surface modification method according to any one of claims 1 to 3.