JP3435853B2 - Surface modification method for fluororesin - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a surface hydrophilic fluorine resin, conductive, high hardness degree, to a method of imparting properties such as adhesion.

[0002]

Fluorine resins are excellent in heat resistance, abrasion resistance, chemical resistance, electrical characteristics, etc. and are used in a wide variety of applications. However, because the surface is hydrophobic and inactive ,
Adhesive, wettability of such coatings have poor adhesion, it is difficult to composite with other materials, or, easily charged due to a very high insulation property, the nature of the hardness of the surface is low, etc. Therefore, their applications were often limited.

[0003] Therefore, as a method of modifying the characteristics of conventionally fluorine resin surface, (1) metallic sodium, naphthalene, and immersed in a mixture of tetrahydrofuran, method or applying it, (2) radiation and ultraviolet A method of irradiating to form a graft polymerized film on the surface, a method of (3) irradiating with low-pressure plasma or the like to sputter-etch the surface to make unevenness and at the same time generate a hydrophilic functional group , etc. have been proposed.

However, in the method (1), in addition to problems such as fire hazard due to metallic sodium and rapid deactivation of chemicals in the air, metallic sodium causes deterioration in performance and reliability. There was a limitation on usage such that it could not be used for related purposes. Further, in the method (2) and (3), the processing apparatus is that Do a very large scale
In order, often industrial use is limited, also, the functional group density is insufficient to produce on the surface, or a is insufficient adhesion to the upper layer to the small fry breaking strength of the modified layer itself It was

Conventionally, it has been difficult to form a uniform thin film by coating a fluororesin since it is generally insoluble in a solvent. However, JP-A-63-238111, JP-A-63-260932, US Pat. Patent 4754009
As seen in the specification, a fluororesin having a fluorine-containing alicyclic structure that is soluble in a special solvent has been developed, and its application as a coating material utilizing its optical characteristics, electrical characteristics, low water absorption, etc. JP 6-120001 A, JP 2-019801, JP 0393
It is disclosed in, 682 JP. However, since this resin also exhibits the surface characteristics peculiar to the above-mentioned fluororesin, its application is often limited.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks recognized in the conventional methods for surface modification of fluororesins, is easy to industrially utilize, and has good wettability and adhesion of the upper layer. It is an object of the present invention to newly provide a method for modifying the surface of a fluororesin which is sufficient.

[0007]

Means for Solving the Problems As a result of intensive studies based on the recognition of the above problems, the present inventor has found that a fluorine resin surface is coated with a primer dissolved in a fluorine-containing solvent to give fluorine. We have newly found that the surface of the resin is made hydrophilic and activated.

Thus, the present invention has been completed based on the above findings, and a silane coupling agent, titane
Coupling agent, aluminum chelate coupling agent
And a solution prepared by dissolving a primer selected from the group consisting of condensates thereof in a fluorine-containing solvent to give a fluorine-containing alicyclic structure.
Characterized in that the applied and dried on the fluorine resin surface with a
It is to that surface modification method of the fluorine resin.

[0009]

The fluororesin having a fluorine- containing alicyclic structure in the present invention (hereinafter also simply referred to as a fluororesin) is obtained by polymerizing a monomer having a fluorine-containing alicyclic structure, or at least two. A polymer having a fluorine-containing alicyclic structure in its main chain obtained by cyclopolymerization of a fluorine-containing monomer having a polymerizable double bond is widely exemplified including known or well-known substances.

[0011] fluorine-containing in the main chain obtained by the fluorine-containing monomer polymerized cyclization having at least two polymerizable double bonds
A polymer having an aliphatic aliphatic ring structure is disclosed in JP-A-63-23.
It is known from JP-A-8111 and JP-A-63-238115. That is, perfluoro (allyl vinyl ether) and perfluoro (butenyl vinyl ether)
It can be obtained by homopolymerization of a monomer such as, or by copolymerization with a radical polymerizable monomer such as tetrafluoroethylene.

[0012] The polymer having a fluorinated aliphatic ring structure in its main chain obtained by polymerizing a monomer having a fluorinated aliphatic ring structure, is known by JP-B-63-18964 Publication. That is obtained by copolymerizing a radical polymerizable monomer such as a homopolymer or tetrafluoroethylene monomers with perfluoro (2,2-dimethyl-1,3-dioxole) fluorinated aliphatic ring structure, such as .

Further, perfluoro (2,2-dimethyl-
Monomers having a fluorinated alicyclic structure such as 1,3-dioxole) and perfluoro (allyl vinyl ether)
And a polymer obtained by copolymerizing a fluorine-containing monomer having at least two polymerizable double bonds such as perfluoro (butenyl vinyl ether).

[0014] Polymers having a fluorinated aliphatic ring structure, a repeating unit have a fluorinated aliphatic ring structure in all the repeating units of the polymer is one that contains more than 20 mol%, transparency, such as mechanical properties It is preferable from the aspect.

In the present invention, the fluorine-containing solvent contains fluorine in the molecule, and as a result, the surface tension is low,
It is not particularly limited as long as it has an affinity with the fluorine resin, in view of the solubility of the primer, 2-perfluorobutyl ethanol, 2-perfluorohexyl ethanol, 2-perfluorooctyl ethanol, collected by trifluoroacetic ethanol, hexafluoroisopropane Piruaruko <br/> Lumpur, 2,2,3,3,3 fluorinated alcohols pentafluoro propanol, perfluoropolyethers, such as hexafluoroacetone trihydrate is illustrated It

[0016] Among these, fluorine-containing alcohols having a boiling point suitable for coating is preferably employed. Further, evaporation rate, boiling point, in order tone pollock solubility, etc. of the primer may be used by mixing these solvents appropriate.

Further, perfluoroalkanes, perfluoro tetrahydrofurans, perfluoro compound such as perfluoroalkyl amine is itself often does not dissolve the primer, so compatible with the fluorine-containing SOLVENTS Alternatively, they may be mixed for the purpose of enhancing the affinity between the surface of the fluororesin and the solvent.

[0018] In addition, the fluorine-containing soluble agents are alcohols,
Ethers, since there is compatibility with hydrocarbon solvents such as ketones, it may be suitably mixed to adjust the evaporation rate of Solvent or primer solubility adjustment.

[0019] In the present invention, the primer is intended to impart an adhesive property to the full fluororesin surface, a silane coupling agent, titanate coupling agent, an aluminum chelate coupling agent, a coupling agent such as a silyl isocyanate and Ru is selected from the group consisting of condensates thereof. You may use these primers in combination of 2 or more types .

Among the specific examples of the above-mentioned primer, a silane coupling agent and its condensate are preferably used because they have excellent solubility in a fluorine-containing solvent and high activity. Here, the silane coupling agent is a silane compound having a hydrolyzable group and other organic reactive group in the molecule. The hydrolyzable group is a group such as an alkoxy group which is hydrolyzed by moisture to generate a silanol group,
The organic reactive group an amino group, mercaptoalkyl group, methacryl Roiruo Kishiarukiru group is a group such as a vinyl group.

A preferred example of the silane coupling agent is 3 -aminopropyltriethoxysilane having an amino group,
Aminopropylmethyldiethoxysilane, aminoethyl-aminopropyltrimethoxysilane, aminoethyl-
Aminosilanes such as aminopropyl methyl dimethoxy silane, or 3-glycine Jiruo <br/> trimethoxysilane having a glycidyl group are glycidyl silanes such as glycine Jiruo propyl methyl dimethoxy silane.

In order to enhance the film-forming property, these silane coupling agents are added to silanes such as tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane and tetramethoxysilane, or aluminum acetylacetonate as a catalyst. Metal alkoxides such as titanium tetraalkoxide, chelates, and acylates may be added.

The concentration of the primer in the fluorinated solvent is not particularly limited, but it is usually desirable to use a primer adjusted to 0.001 to 20% by weight, and further 0.01 to
A concentration of 10% by weight is preferably adopted. If the film thickness of the primer layer is too small, the surface modification will be insufficient, and if it is too large, the original characteristics of the fluororesin may be impaired, so the film thickness after coating is 1 nm to 50 μm, and further 1 nm.
It is desirable that it is ˜1 μm.

The method of applying the fluorine-containing solvent containing the primer to the surface of the fluororesin may be appropriately selected from known or known methods in consideration of the film thickness of the coating film, the uniformity, the shape of the object to be coated, and the like. Spin coating method, dipping method, potting method, roll coating method, bar coating method, printing method, die coating method, curtain flow coating method,
A spray coating method and the like are exemplified. Further, after coating, the solvent is volatilized, in order to make the primer coating firm, intends row drying of usually about 50 to 350 ° C..

In order to obtain a desired surface condition, a fluorine-containing solvent containing a primer may be applied to improve the wettability of the surface, and then one or more layers may be further formed thereon. The thickness of the other film is not particularly limited, from film-shaped ones to sheet-shaped ones. Further, a molded product having a thickness larger than that of a sheet-shaped product may be used.

When forming another film, as a matter of course, since the solvent in which the film material is dissolved is applied after the wettability of the fluororesin surface is improved, it is not necessary to use a fluorine-containing solvent as this solvent. Therefore the type of formable film material is not at all restricted, known or from known materials may be appropriately selected a substance suited to the purpose.

For example, when it is desired to impart adhesiveness to the surface of fluororesin, polyimide, polyamide, polyamideimide,
Adhesive polymers or oligomers such as epoxy resin, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl pyrrolidone, melamine resin, urethane resin and cyanoacrylate may be exemplified.

Among these, polyimide is preferably used from the viewpoint of excellent heat resistance and chemical resistance. The composite formed by forming polyimide on the fluororesin retains the excellent electrical characteristics, heat resistance and chemical resistance of the fluororesin,
Wettability on the surface, and that the adhesive has been applied.

As the polyimide, a polymer obtained by reacting an aromatic diamine with an aromatic tetracarboxylic dianhydride, or an aromatic diamine, an aromatic tetracarboxylic dianhydride, an aromatic diamide carbonamide, etc. The polymer obtained by the reaction can be exemplified. Further, also the addition of diaminosiloxane as a copolymer component, which the polymer end was stopped with aminosilane, or the polymer solution an aminosilane may be one obtained by adding an adhesion improving agent such as aluminum chelate.

[0030]

EXAMPLES Next, examples of the present invention will be described more specifically, but it goes without saying that the description does not limit the present invention.

"Synthesis Example 1" 35 g of perfluorobutenyl vinyl ether, 150 g of ion-exchanged water, and ((CH ₃ ) ₂ as a polymerization initiator)
90 mg of CHOCOO) ₂ was put into a pressure-resistant glass autoclave having an internal volume of 200 cc. After purging the system with nitrogen three times, suspension polymerization was carried out at 40 ° C. for 22 hours to obtain a fluororesin. This is called resin A.

The intrinsic viscosity of the resin A [eta] is in perfluoro (2-butyl tetrahydrofuran), at 30 ° C.,
It was 0.34 dl / g. Glass transition point of polymer is 1
Was 08 ° C., tough transparent Tsu vitreous polymer Der at room temperature. The 10% thermal decomposition temperature was 465 ° C., and the dielectric constant was 2.1. The surface free energy of this polymer was 19 dyn / cm ² .

"Synthesis Example 2" Perfluoro (2,2-dimethyl-1,3-dioxole) and perfluoro (butenyl vinyl ether) were radically copolymerized to obtain a fluororesin having a glass transition point of 160 ° C. This is called resin B. This resin B was colorless and transparent and had a dielectric constant of 2.0. The surface free energy of this polymer was 19 dyn / cm ² .

"Preparation of Surface Modification Solution" 1 g of 3-aminopropyltriethoxysilane was added at room temperature to 2
-A solution of perfluorohexyl ethanol in 100 g was obtained. This is called solution A.

3-aminopropyltriethoxysilane 1
g was dissolved in 100 g of 2,2,3,3,3-pentafluoropropanol at room temperature to obtain a solution. This is solution B
Say.

[0036] 3-glycine Jiruo trimethoxysilane 1g to give a solution dissolved in 2-perfluorohexyl ethanol 100g at room temperature. This is called solution C.

[Example 1] The resin A obtained in Synthesis Example 1 was dissolved in perfluorotributylamine to prepare a 9% by weight solution. This solution was applied onto a silicon wafer with a spin coater and dried in an oven at 50 ° C. for 1 hour and 270 ° C. for 1 hour to form a coating film having a thickness of 3 μm. This is called a resin film a. The resin film a formed was on the wafer, the solution A was applied by a spin coater, 200 ° C. on a hot plate was dried for 1 minute.

Next, a liquid epoxy resin chip coat 1310 (manufactured by Hokuriku Paint Co., Ltd.) was applied onto the dried resin film a by a dispenser and cured at 150 ° C. for 1 hour. At this time, the wet spreadability of the epoxy resin film was good. Moreover, when the adhesion strength between the resin film a and the epoxy resin film was measured by a push-pull gauge, it was 12 kgf.
/ Cm ² , and had good adhesion.

Example 2 The resin A obtained in Synthesis Example 1 was dissolved in perfluorotributylamine to prepare a 9% by weight solution. This solution was applied by a spin coater on a silicon wafer treated with 3-aminopropyltriethoxysilane, between 100 ° C. 2 minutes on a hot plate and dried between 200 ° C. 10 minutes, the thickness of 3μ coating Was formed. This is called a resin film b. The solution A is applied on the wafer having the resin film b formed thereon by a spin coater, and the hot plate is applied at 200 ° C. for 1 hour.
The dry between minute were carried out.

Then, a 2% by weight solution of polyamic acid in N-methylpyrrolidone was applied onto the dried resin film b by a spin coater, and was applied on a hot plate at 200 ° C. for 1 hour.
After drying between 0 min, 350 ° C. oven for 30 minutes
By baking for a period of time, an imidization (dehydration condensation) reaction was performed to form a polyimide film. This sample of a pressure cooker test (127 ℃, at 100% RH, 2
The adhesiveness of the polyimide film after 0 hour) was tested by a cross-cut tape peeling test, and it was found that there was no peeling and the adhesiveness was good.

Example 3 Except that the step of applying the solution A by the spin coater was changed to the step of applying the solution B by the dip coater.
When the same evaluation as in Example 2 was performed, no peeling of the polyimide film was observed in the cross-cut tape peeling test, and good adhesiveness was obtained.

Example 4 The same evaluation as in Example 1 was carried out except that the solution A was changed to the solution C, and the adhesion strength was 15 kgf / cm ² , and the epoxy resin film had good adhesion. Was.

[Embodiment 5] In Embodiment 1, the liquid epoxy resin chip coat 13 is used.
10 (manufactured by Hokuriku Paint Co., Ltd.), epoxy pellets ST-80
A sample was prepared in the same manner as in Example 1 except that the sample was changed to 00H (manufactured by Nitto Denko Corporation) and was molded by the transfer molding method. The adhesive strength between the resin and the epoxy resin film measured by the 90-degree peel tester was 2 kgf / cm, and the adhesiveness was good.

Comparative Example 1 1 g of 3-aminopropyltriethoxysilane was dissolved in 100 g of water / ethanol (weight ratio 5/95) mixed solvent to obtain a solution. This is called solution D.

When the resin film a of Example 1 was formed on a silicon wafer and the solution D was applied thereto by a spin coater, the solution D was completely repelled on the resin film a and applied. I couldn't.

"Comparative Example 2" In Example 1 , the same evaluation as in Example 1 was carried out without treating the surface of the resin film a with the solution A. As a result, the epoxy resin was beaded. The wettability was poor. Further, the adhesion strength between the resin film a and the epoxy resin is 0.
It was 5 kgf / cm ² .

[Comparative Example 3] In Example 2 , when the surface of the resin film b was not treated with the solution A and a polyimide film was formed on the resin film b in the same manner as in Example 2, a polyamic acid was obtained. The solution of No. 1 repelled into a bead, and a film could not be formed by spin coating.

[0048]

INDUSTRIAL APPLICABILITY According to the present invention, the surface of a fluororesin can be easily and effectively modified by applying a primer dissolved in a fluorine-containing solvent to impart hydrophilicity, adhesiveness and the like. It has an excellent effect.

Claims (4)

(57) [Claims] 1. A silane coupling agent, a titanate-based cup
Pulling agents, aluminum chelate-based coupling agents and the like
A surface of a fluororesin characterized in that a solution prepared by dissolving a primer selected from the group consisting of a condensate in a fluorine-containing solvent is applied to the surface of the fluororesin having a fluoroaliphatic ring structure and dried. Modification method. 2. The method according to claim 1, wherein the fluorinated solvent is a fluorinated alcohol. 3. The process as claimed in claim 1 or 2 primer is a silane coupling agent. 4. The method of claim 1 complex to form a polyimide resin film on the surface-modified fluororesin by a method according to any one of 3.