JP2001122995A - Surface treatment of fluorine resin and production of laminated body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for surface treatment of fluorine resins that is characterized by subjecting the surface of the fluorine resin to the surface treatment so that the absorbance at 360 nm wavelength may become >=0.02/100 cm2 according to the iodometry, and provide a production process for laminated bodies that is characterized by laminating a crosslinkable elastic adhesive to a fluorine resin and integrating them. SOLUTION: According to this invention, a fluorine resin treatment suitable for giving a laminated body by firmly adhering the fluorine resin to the crosslinkable elastic adhesive and can simply and surly produce the laminated bodies having excellent adhesion and storage stability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a window material for a building or the like having at least a portion where a fluororesin and a crosslinked elastic adhesive such as an ethylene-vinyl acetate copolymer are directly bonded at least in part. More specifically, a method for producing a laminate used mainly for outdoor electric members and the like is described in more detail. A surface treatment method of a fluororesin suitable for imparting adhesiveness to the fluororesin for the laminate, and this treatment method The present invention relates to a method for producing a laminate using a fluororesin treated with the above.

[0002]

2. Description of the Related Art A laminate comprising a fluororesin and a crosslinked elastic adhesive such as an ethylene-vinyl acetate copolymer (EVA) directly joined to a fluororesin is known as a laminate material surface or a solar cell. It is used for bonding, surface protection, imparting antifouling property, sealing and the like.

In this case, the adhesion performance between the fluororesin and the crosslinked elastic adhesive requires not only storage stability but also weather resistance such as heat resistance after crosslinked adhesion and ultraviolet resistance in terms of use environment. ing.

By the way, various surface treatments are applied to the fluororesin before bonding in order to strengthen the adhesion with the crosslinked elastic adhesive. Sodium treatment, sandblasting,
Flame treatment, corona treatment, low pressure plasma treatment, sputter etching treatment, radiation irradiation treatment and the like can be mentioned.

[0005] However, even if a fluororesin surface-treated by these treatment methods is used, the adhesive strength may be insufficient in some cases, and at present, the effect of the surface treatment is not utilized to the maximum.

The present invention has been made in view of the above circumstances, and is suitable for reliably producing a laminate in which a fluorine resin and a crosslinked elastic adhesive such as an ethylene-vinyl acetate copolymer are directly and firmly joined. It is an object of the present invention to provide a method for surface treatment of a fluororesin and a method for producing a laminate.

[0007]

Means for Solving the Problems and Embodiments of the Invention The present inventors have conducted intensive studies in order to achieve the above object, and as a result, have found that acidic or reducing functional groups generated when a fluororesin is surface-treated. And a radical-generating functional group (diazo group, peroxide, etc.), and an iodometry method showing the presence of the above-mentioned functional group (known literature, organic peroxide Oxide Chemistry, edited by Yoshio Ogata Nanedo p331 (197
1), Jane E. Frew, et al, Anal
ytica Chimica Acta, 155, p1
39 (1983), Masayuki Yoshida, Synthetic Organic Chemistry 27, p.
257 (1969)), 360
I was examined peak ^- I ₃ detected by nm.

As a result, when the absorbance at 360 nm is 0.02 / 100 cm ² or more, the absorbance is preferably 0.02 / 100 cm ^2.
Fluororesin treated so that a value of 3/100 cm ² or more is detected is excellent in overall adhesion performance, and the treated fluororesin and a crosslinked elastic material such as ethylene-vinyl acetate copolymer are used. By directly laminating and integrating the adhesive, the fluororesin and the above-mentioned crosslinked elastic adhesive are firmly joined, and the storage stability, surface protection, antifouling property, high transparency, member sealing property The present inventors have found that a laminated body requiring the above can be reliably manufactured, and have accomplished the present invention.

Therefore, according to the present invention, the fluororesin surface has an absorbance at 360 nm by iodometry of 0.02 / 1.
A surface treatment method for a fluororesin characterized by being subjected to a surface treatment so as to be not less than 00 cm ² , and when manufacturing a laminate in which the fluororesin is directly bonded to a crosslinked elastic adhesive, Provided is a method for manufacturing a laminate, characterized in that a crosslinked elastic adhesive is bonded to a resin surface and integrated.

Hereinafter, the present invention will be described in further detail. First, the surface treatment method of a fluororesin according to the first invention of the present invention is applied to a fluororesin in order to optimize the adhesiveness with a crosslinked elastic adhesive. On the other hand, the treatment is performed so that the absorbance in the iodometry method becomes 0.02 / 100 cm ² or more.

Here, the fluororesin is not particularly limited, but for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl Vinyl ether copolymer (PFA), polychlorotrifluoroethylene (PCT)
FE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and the like. Various selections can be made according to the application.

In the present invention, the ethylene-tetrafluoroethylene copolymer is thermoplastic, and has moldability, heat resistance, chemical resistance, electric characteristics (dielectric characteristics), non-adhesion, friction resistance, and cut-through resistance. It is suitable for use as a surface material of electric members used outdoors, for example, because it is excellent in radiation resistance, ultraviolet ray transmission, infrared ray absorption and the balance of these properties.

[0013] processing method of the present invention, the surface of the fluororesin by iodometry, I ₃ ^- peak is obtained 36
The absorbance at 0 nm is adopted as a standard indicating the amount of a radical-generating functional group (azo group, peroxide), and the absorbance is 0.02 / 100 cm ² or more, particularly 0.03 / 10
0 cm ² or more is required. Absorbance is 0.0
If it is less than 2/100 cm ^2, the amount of the radical-generating functional group is too small, and sufficient adhesiveness to the crosslinked elastic adhesive cannot be provided.

In this case, the above-mentioned measuring method is described in the above-mentioned known literature (Organic Peroxide Chemistry, edited by Yoshio Ogata, Nanedo p.
331 (1971); Frew, et
al, Analytica Chimica Act
a, 155, p139 (1983), Masayuki Yoshida, Synthetic Organic Chemistry 27, p257 (1969)).

In the present invention, if the absorbance of the fluororesin is obtained, various surface treatment methods can be adopted, for example, corona treatment, flame treatment, low pressure plasma treatment, atmospheric pressure plasma treatment, ultraviolet irradiation treatment, laser irradiation treatment. And electron beam irradiation treatment, radiation irradiation treatment and the like. In the present invention, it is particularly preferable to employ corona treatment.

Here, the corona treatment can be performed by a known method, for example, a method of performing the treatment in a nitrogen gas atmosphere under a low oxygen gas concentration. As a method of lowering the oxygen gas concentration, specifically, a method of spraying a gas other than the oxygen gas under atmospheric pressure to a portion where corona discharge is generated, a method of covering the corona discharge portion with a polymer sheet or the like, and sealing After that, there is a method of replacing the internal gas with a gas other than oxygen, but these methods may be used in combination. Examples of the gas other than oxygen include nitrogen, argon, carbon dioxide, helium, tetrafluoromethane, and the like. In particular, nitrogen gas is preferable because it is inexpensive and has no danger.
The oxygen concentration can be measured by, for example, a galvanic cell type densitometer.

Next, a second invention of the present invention is a method for producing a laminate in which a crosslinked elastic adhesive is bonded to a fluororesin treated by the above method of the present invention and integrated.

Here, in order to obtain a crosslinked elastic adhesive, an ethylene-vinyl acetate copolymer composition can be suitably used, and the vinyl acetate content is 5 to 50% by mass, particularly 10 to 45% by mass. % Can be suitably used.

When the above-mentioned copolymer composition is used as a sealing material, it can be used in the form of a sheet or the like. However, after bonding to a fluororesin, this can be crosslinked to be integrated with the fluororesin. preferable. Accordingly, examples of the crosslinked elastic adhesive composition include heat and / or photocurable crosslinked elastic adhesive compositions containing an organic peroxide and / or a photosensitizer. An acryloxy group-containing compound, a methacryloxy group-containing compound, an allyl group-containing compound, a silane coupling agent, an epoxy group-containing compound, a hydrocarbon resin, and the like can be further added to the product from the viewpoint of adhesiveness.

For example, for thermal curing of the ethylene-vinyl acetate copolymer, an organic peroxide can be added. The organic peroxide decomposes at a temperature of 70 ° C. or more to generate radicals. Any substance can be used as long as the decomposition occurs, but a decomposition temperature having a half-life of 10 hours and a decomposition temperature of 50 ° C. or higher is preferable.

Examples of usable organic peroxides include 2,5-dimethylhexane-2,5-dihydroperoxide and 2,5-dimethyl-2,5-di (t-butylperoxy) hexine. -3, di-t-butyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane,
Dicumyl peroxide, α, α′-bis (t-butylperoxyisopropyl) benzene, n-butyl-4,
4′-bis (t-butylperoxy) valerate, 1,
1-bis (t-butylperoxy) cyclohexane,
1,1-bis (t-butylperoxy) -3,3,5-
Trimethylcyclohexane, t-butylperoxybenzate, t-butylperoxyacetate, methyl ethyl ketone peroxide, 2,5-dimethylhexyl-2,5-bisperoxybenzoate, butyl hydroperoxide, p-methane hydroperoxide, p-Chlorobenzoyl peroxide, t-butylperoxyisobutyrate, hydroxyheptyl peroxide, chlorohexanone peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, cumylperoxy octoate, succinic acid Peroxide, acetyl peroxide, t-butylperoxy (2-ethylhexanoate), m-toluoyl peroxide, benzoyl peroxide, , 4-dichlorobenzoyl peroxide. As organic peroxides,
At least one of these may be used alone or in combination of two or more.
It can be used by adding 0.1 to 10 parts by mass with respect to parts by mass.

When a photosensitizer is added for photocuring the ethylene-vinyl acetate copolymer, a radical photopolymerization initiator is suitably used as the photosensitizer. Among the radical photopolymerization initiators, examples of the hydrogen abstraction initiator include benzophenone, methyl orthobenzoylbenzoate,
Benzoyl-4′-methyldiphenyl sulfide, isopropylthioxanthone, diethylthioxanthone,
Ethyl-4- (diethylamino) -benzoate and the like are used. Further, among radical photopolymerization initiators, benzoin ether, benzyldimethyl ketal and the like are used as an intramolecular cleavage type initiator, and 2-hydroxy-2-methyl-1-phenylpropan-1-one is used as an α-hydroxyalkylphenone type. , 1-hydroxycyclohexylphenyl ketone, alkylphenylglyoxylate, diethoxyacetophenone, etc., and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 as α-aminoalkylphenone type , 2-
Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and the like, and acylphosphine oxide and the like are used. As a photosensitizer,
At least one of these can be used alone or as a mixture of two or more, and it can be used by adding 0.1 to 10 parts by mass to 100 parts by mass of the copolymer.

In addition to the above-mentioned photosensitizer, the above-mentioned organic peroxide may be blended if necessary, so that thermosetting can be used together with photocuring.

Further, as described above, at least one of an acryloxy group-containing compound, a methacryloxy group-containing compound, and an allyl group-containing compound can be added to the copolymer. As the acryloxy group or methacryloxy group-containing compound used for this purpose, acrylic acid or methacrylic acid derivatives, for example, esters thereof can be used. Examples of the alcohol residue of the ester include an alkyl group having 1 to 24 carbon atoms, such as a methyl group, an ethyl group, a dodecyl group, a stearyl group, and a lauryl group, and an alkyl group having 1 to 18 carbon atoms. 6, halogen substitution such as tetrahydrofurfuryl group, aminoethyl group, 2-hydroxyethyl group, 3-hydroxypropyl group, 3-chloro-2-hydroxypropyl group, hydroxyl substitution, amino substitution, etc. Substituted alkyl group (alkyl group having 1 to 24 carbon atoms, particularly 1 to 1 carbon atoms)
8) and glycidyl groups. Furthermore,
Esters with polyfunctional alcohols such as ethylene glycol, triethylene glycol and polyethylene glycol can also be used.

As the allyl group-containing compound, diallyl phthalate, diallyl fumarate, diallyl nurate, triallyl isocyanurate, triallyl cyanurate and the like can be used.

These compounds can be used alone or in combination of two or more. The compounding amount is sufficient if it is 50 parts by mass or less based on 100 parts by mass of the copolymer. It can be 0.1 to 50 parts by mass, especially 0.5 to 20 parts by mass.

In order to further improve the adhesiveness,
It is preferable to add a silane coupling agent. Known silane coupling agents for this purpose include, for example, γ-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ
-Methacryloxypropyltrimethoxysilane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (amino Ethyl) -γ-aminopropyltrimethoxysilane. The amount of these silane coupling agents to be blended is 10 parts by mass or less with respect to 100 parts by mass of the copolymer, preferably 0.01 to 10 parts by mass, more preferably 0.01 to 5 parts by mass. Part.

Further, an epoxy group-containing compound other than epoxysilane can be added as an adhesion promoter. Such epoxy group-containing compounds include triglycidyl tris (2-hydroxyethylene) isocyanurate, neopentyl glycol diglycidyl ether,
1,6-hexanediol glycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenol polyoxyethylene (5 mol) glycidyl ether, pt
-Butylphenyl glycidyl ether, diglycidyl adipate, glycidyl o-phthalate,
Glycidyl methacrylate, butyl glycidyl ether and the like can be mentioned. The same effect can be obtained by using an alloy of a polymer containing an epoxy group. These epoxy group-containing compounds,
One type can be used alone or two or more types can be used as a mixture.
-20 parts by weight, especially 0.1-20 parts by weight, is sufficient.

The hydrocarbon resin is used in an amount of 0 to 200 parts by mass, preferably 5 to 150 parts by mass, more preferably 10 to 100 parts by mass based on 100 parts by mass of the ethylene-vinyl acetate copolymer.
-100 parts by mass may be added. This hydrocarbon resin is
Either a natural resin or a synthetic resin may be used.

In the natural resin system, rosin, rosin derivative,
Terpene resins are preferably used. As the rosin, a gum resin, a tall oil resin, or a wood resin can be used. As the rosin derivative, rosin obtained by hydrogenation, disproportionation, polymerization, esterification, and metal salification can be used. In terpene resins, α-pinene, β
-In addition to terpene resins such as pinene, terpene phenol resins can be used. Further, dammar, koval, and shellac may be used as other natural resins. On the other hand, in the case of synthetic resin, petroleum resin, phenol resin, and xylene resin are preferably used. As the petroleum resin, aliphatic petroleum resin, aromatic petroleum resin, alicyclic petroleum resin, copolymer petroleum resin, hydrogenated petroleum resin, pure monomer petroleum resin, cumarone indene resin, and the like can be used. . As the phenolic resin, an alkylphenol resin and a modified phenol resin can be used. As the xylene-based resin, a xylene resin or a modified xylene resin can be used.

In addition to the above additives, antioxidants, dyes,
A processing aid, an ultraviolet absorber and the like may be added.

The ethylene-vinyl acetate copolymer composition contains the above copolymer, a curing agent (organic peroxide and / or photosensitizer), a silane coupling agent, an acryloxy group, a methacryloxy group or an allyl group. After weighing a predetermined amount of a compound or the like and uniformly mixing the mixture with a kneading machine such as a roll mill or a kneader, forming a film to a desired width and thickness with a film forming apparatus such as a calendar roll, a T-die extruder, and inflation. Can be.

Here, the film thickness is 1 to 1000 μm.
And more preferably 5 to 800 μm
It is.

The composition layer thus formed is coated with a fluororesin which has been subjected to a surface treatment so as to have an absorbance at 360 nm of 0.02 / 100 cm ² or more in the above-mentioned iodometry method, for example, by hot pressing. And can be integrated by a laminating method. In this case, when the ethylene-vinyl acetate copolymer is heat-cured, it depends on the kind of the organic peroxide to be used. Preferably, the heating is performed for up to 30 minutes. Curing is 1-5000 kPa, preferably 10-20
Heating under a pressure of 00 kPa is preferable from the viewpoint of adhesiveness. On the other hand, in the case of photo-curing, curing can be performed by irradiating the laminate with ultraviolet rays using a mercury lamp or the like. Also, to shorten the curing time and improve the degree of curing,
While heating the laminate to 40 to 120 ° C. in advance, the laminate may be irradiated with ultraviolet rays.

The laminate obtained by the method of the present invention comprises:
For example, it is used as a window material of a building or the like and an electric member mainly used outdoors.In this case, in the production of this laminated body, the steps other than directly joining the fluororesin and the crosslinked elastic adhesive are: It can be performed by a conventional method.

[0036]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Examples and Comparative Examples] The following ethylene-tetrafluoroethylene copolymer film (100 μm thick) was used as a fluororesin film, subjected to corona discharge treatment by the following method, and measured for energy density and absorbance by iodometry. It was measured. For comparison, a heat treatment was performed in the same manner as the above-mentioned copolymer film except that the corona discharge treatment was not performed on the fluororesin film, and the measurement was performed in the same manner. The measured values are also shown in Table 1.

Fluororesin film NEOFLON ETFE EF-0 manufactured by Daikin Industries, Ltd.
100 corona discharge treatment The discharge electrode (30 cm width) of the corona treatment device is covered with an acrylic resin container, nitrogen gas is flowed at 10 L / min under atmospheric pressure, and corona output is performed using a Tantec HV05-2 type power supply. 250W, film moving speed 1mm /
Processed in minutes. Absorbance A solution for absorbance analysis was prepared as follows. Benzene 40 mL, 2-propanol 60 mL, iron chloride 1
A saturated amount of sodium iodide was added to the mixed solution adjusted to ppm. In 10 mL of this mixed solution, 100 cm ² of one side of the treated or untreated fluororesin film was immersed,
The mixture was kept at 60 ° C. for 10 minutes, and then 1 mL of water was quickly added to stop the reaction. During this time, I ^- is oxidised by radical-generating functional groups including peroxides, I ₃ ^- and becomes. The solution having undergone the above-described operation was transferred to a quartz glass cell having an optical path length of 10 mm, and a Hitachi U-
Using 4000 spectrophotometer, I ₃ ^- 3 is the absorption wavelength of the
The absorbance at 60 nm was measured.

Next, a film (500 μm) of an ethylene-vinyl acetate copolymer composition having the following composition was bonded to the fluororesin film subjected to the corona discharge treatment as described above and the fluororesin film not subjected to the corona discharge treatment. A 100 μm-thick polyester film was bonded to the surface of the film of the ethylene-vinyl acetate copolymer composition opposite to the surface to which the fluororesin was bonded. 150 ° C, 1
The film was heat-pressed at 1000 kPa for 5 minutes to cure and integrate the film.

Ethylene-vinyl acetate copolymer composition ultracene 634 ^* 100 parts by mass triallylisocyanurate 2 γ-methacryloxypropyltrimethoxysilane 0.5 1,1-bis (t-butylperoxy) 3,3 , 5-trimethylcyclohexane 2 * Ultracene 634: an ethylene-vinyl acetate resin manufactured by Tosoh Corporation, vinyl acetate content 26% by mass

The adhesive strength of each of the obtained laminates was examined using an autograph (AGS-100D) manufactured by Shimadzu Corporation. Table 1 shows the results.

[0042]

[Table 1]

[0043]

According to the present invention, it is possible to carry out a treatment of a fluororesin capable of directly and firmly bonding to a crosslinked elastic adhesive, and according to the method of the present invention, it is possible to improve adhesion and storage stability. An excellent laminate can be easily and reliably manufactured.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // C08L 27/18 C08L 27/18 F term (reference) 4F070 AA13 AA28 AC56 AE08 GA05 GC02 GC08 4F073 AA01 BA11 BA15 BA16 BA48 BB01 CA01 CA21 CA41 CA42 CA45 CA46 GA03 4F100 AK17A AK18A AK18J AK68B AL01A AR00B BA02 CA30 EJ05B EJ053 EJ551 EJ64A GB07 GB90 JK07B JL11 JL11B JN30A YY00A 4J002 BB04W BB04W06

Claims (7)

[Claims] 1. A method for treating a surface of a fluororesin, wherein the surface of the fluororesin is treated so that the absorbance at 360 nm by iodometry becomes 0.02 / 100 cm ² or more. 2. The method according to claim 1, wherein the absorbance is 0.03 / 100 cm ² or more. 3. The method according to claim 1, wherein the fluororesin is an ethylene-tetrafluoroethylene copolymer. 4. A method for producing a laminate in which a fluororesin and a crosslinked elastic adhesive are directly joined, according to claim 1.
A method for producing a laminate, characterized in that a crosslinked elastic adhesive is adhered to the surface of the fluororesin treated by the method according to any one of the above, and integrated. 5. The method for producing a laminate according to claim 4, wherein the crosslinked elastic adhesive is bonded to a fluororesin and then crosslinked. 6. The method for producing a laminate according to claim 4, wherein the crosslinked elastic adhesive is crosslinked with a radical initiator. 7. The method for producing a laminate according to claim 4, wherein the crosslinked elastic adhesive has an ethylene-vinyl acetate copolymer as a main component.