JP3433931B2 - Modification method of fluororesin molded body surface - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified surface of a fluororesin molded article for imparting high adhesion durability to the surface of the fluororesin molded article, particularly to rubber, especially, high conductivity silicone rubber. Regarding quality law.

[0002]

2. Description of the Related Art Fluorine resin is superior to other resins in that it is superior in water / oil repellency, slidability, antifouling property, heat resistance, chemical resistance, and electrical characteristics. However, due to its inactive surface, it has a drawback in that it is difficult to apply an adhesive or paint, and it is difficult to form a composite with other materials.

Various methods have been proposed as solutions to such problems. For example, (i) a method of treating with a complex compound solution prepared from a solution of sodium metal and naphthalene in tetrahydrofuran [ER Nelson]
Ind. Eng. Chem., 50, 329 (1958).
Year)], (ii) Method using glow discharge [Kakuda et al., Industrial Materials, Vol. 29 (No. 2), p. 105 (1981)], (iii) RF sputter etching under low pressure Method (see Japanese Patent Publication No. 53-22108),
(iv) A method of irradiating laser light in a special gas atmosphere such as B (CH ₃ ) ₃ or Al (CH ₃ ) ₃ (JP-A-2-
(See Japanese Patent Publication No. 196834), (v) Method of directly irradiating excimer laser light (see Japanese Patent Publication No. 3-57143),
(vi) Method of processing by low temperature plasma sputter etching (Japanese Patent Publication No. 58-21928, JP-A No. 2-1274)
No. 42 and Japanese Patent Publication No. 3-58375) and (vii) a method of irradiating an ultraviolet laser beam after previously kneading a light-absorbing substance (see Japanese Patent Laid-Open No. 5-125208).
Etc.

However, these reforming methods have the following problems. In the case of method (i), there is a risk of ignition during processing and the processing liquid is unstable, which is not only a problem in terms of work hygiene but also that the surface of the modified surface is exposed when exposed to sunlight or high temperature. There is a drawback that the adhesiveness and the like are significantly reduced. The method (ii) has a drawback that the effect of surface modification is significantly lower than that of a fluorine-free polymer such as polyethylene. In the case of the method (iii), the processing speed is slow, the etched resin component is expensive and not only adheres to the inside of a large-sized vacuum processing apparatus, but also the easily abraded irregularities formed on the resin surface have a low flow rate. There is a problem that it does not provide sufficient adhesiveness, paintability, etc., to a hydrophilic adhesive or paint. In the case of the method (iv), there is a problem that the processing speed is slow, a highly toxic gas and an expensive and large vacuum processing apparatus are required. Method
In the case of (v), there is a drawback that the adhesiveness and wettability of the fluororesin surface cannot be sufficiently improved. Furthermore, method (vi)
In the case of, since the chemical composition of the treated surface does not change, it is difficult to obtain high adhesive strength, and in order to obtain the same adhesiveness as in method (i) in which relatively high adhesive strength is obtained, a narrow range is required. The treatment must be carried out for a long time under the treatment conditions of No. 1, which is not sufficient as an industrial treatment technique. Furthermore, the method (vii) has a drawback that it cannot be applied to the surface modification of a fluororesin molding containing no light absorbing substance.

The present applicants have previously provided a method for solving various problems of the above-mentioned modification method of the fluororesin surface and generally imparting high adhesiveness and wettability to the fluororesin surface (Patent No. 2983438). However, a fluororesin molded product whose surface is modified by this method is mixed with various additives (for example, a conductivity-imparting agent, a vulcanizing agent, a vulcanization aid, a softening agent, etc.) in a rubber material (for example, silicone). Rubber, butadiene rubber, styrene rubber, chloroprene rubber, ethylene propylene rubber, natural rubber, etc.), especially conductive silicone rubber mixed with additives such as conductive carbon black, or thermally conductive silicone highly filled with silica / alumina, etc. It has been found that when it is adhered to rubber or the like, the durability of the adhesion is poor.

This problem is caused by various rollers used in, for example, electronic copying machines and laser beam printers.
That is, various rollers (for example, a charging roller, a developing roller, a transfer roller, a fixing roller, etc.) having a structure in which the coating layer of the metal cylindrical core whose outer peripheral surface is coated with a rubber material is further coated with a fluororesin tube. It is an important technical issue in the field of pressure rollers.

[0007]

DISCLOSURE OF THE INVENTION The present invention has solved the above technical problems and has a high adhesive durability, particularly fluorine, for rubber, especially conductive silicone rubber and heat conductive silicone rubber. It was made in order to provide a method that can be applied to the resin surface.

[0008]

That is, the present invention is to adhere a solution, dispersion or suspension containing an organosilicon compound, an ultraviolet absorbing compound and a fluorosurfactant to the surface of a fluororesin molded article, It relates to a method for modifying the surface of a fluororesin molded article, which comprises irradiating the adhered surface with an ultraviolet laser beam.

The fluororesin molding to which the present invention is applied is a molding manufactured from a fluorine-containing organic polymer compound. As the base resin of the molded article, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer
(FEP), tetrafluoroethylene-hexafluoropropylene-perfluoroalkoxyethylene terpolymer (EPE), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PC
TFE), trifluorochloroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF),
Polyvinyl fluoride (PVF), tetrafluoroethylene-
Perfluoromethoxyethylene copolymer (MFA), vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer (THV), tetrafluoroethylene-propylene copolymer , DAIEL THERMO PLASTIC (manufactured by Daikin Industries), Central Soft (manufactured by Central Glass), Teflon AF (manufactured by DuPont), CYTOP (manufactured by Asahi Glass), DIONION HTE (manufactured by 3M) and a mixture of any two or more thereof. A resin is exemplified. Further, silica, alumina, silicon carbide, silicon nitride or the like may be appropriately added for the purpose of improving wear resistance, and carbon black or the like may be appropriately added for the purpose of imparting electric conductivity. The specific form of the fluororesin molded product to be treated by the present invention is not particularly limited, and examples thereof include a molded product having a sheet, a film, a tube, a pipe, a porous film and any other shape.

As the organic silicon compound, those known per se may be appropriately used, and particularly preferable compounds are:
(Triphenylsilyl) acetylene, phenylsilane,
Examples thereof include tetraphenoxysilane, triphenylsilane, tribenzylsilane, allyltriphenylsilane, triphenylvinylsilane and phenyltriethoxysilane. If desired, two or more such organosilicon compounds may be used in combination.

As the ultraviolet absorbing compound, those known per se may be appropriately used, and are not particularly limited, but aromatic ultraviolet absorbing compounds such as aromatic hydrocarbons, aromatic carboxylic acids and the like. Salts, aromatic aldehydes, aromatic alcohols, aromatic amines and salts thereof, aromatic sulfonic acids and salts thereof, and phenols are preferable. The following are examples of this type of aromatic ultraviolet absorbing compound.

Naphthalene, phenanthrene, anthracene, naphthacene, pyrene, perylene, fluorenone, fluoranthene, 9-acetylanthracene, 9-methylanthracene, anthraquinonecarboxylic acid, anthracene
-9-methanol, biphenyl, sodium benzoate, phthalic acid, benzaldehyde, benzyl alcohol, phenylethanol, benzenesulfonic acid, 2-naphthalenesulfonic acid, sodium anthraquinone-2-sulfonate, phenol, cresol, 2,4-dihydroxybenzophenone , 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2,2'-dihydroxy-4 -Methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxy-5-
Sulfobenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2'-hydroxy-
4-chlorobenzophenone, 2 (2'-hydroxy-5-
Methoxyphenyl) benzotriazole, 2 (2'-hydroxy-3 ', 5'-di-t-butylphenyl) benzotriazole, 2 (2'-hydroxy-3'-t-butyl-5'
-Methylphenyl) benzotriazole, phenyl salicylate, p-octylphenyl salicylate, p salicylate
-T-butylphenyl, carboxyphenyl salicylate, strontium salicylate, methyl salicylate, dodecyl salicylate, resorcinol monobenzoate,
2-ethylhexyl-2-cyano-3,3-diphenyl acrylate, ethyl-2-cyano-3,3-diphenyl acrylate, Ni-bisoctylphenyl sulfide, [2,2'-thiobis (4-t-octylphenolato) )]
-N-butylamine-Ni.

As the fluorine-containing surfactant used together with the above-mentioned organosilicon compound and ultraviolet absorbing compound, a known surfactant having a fluorocarbon chain as a hydrophobic group may be appropriately used. Examples of this type of fluorine-based surfactant include the following surfactants. (1) Anionic fluorinated surfactant R _f COOM R _f SO ₂ N (R) ₂ CH ₂ COOM R _f CONRYOSO ₃ M R _f SO ₂ NRYOSO ₃ M R _f SO ₃ M R _f CH ₂ O (CH ₂ ) ₂ SO ₃ M

[Chemical 1]

[Chemical 2]

[Chemical 3] In the above formula, R _f and R _f 'represent a fluoroalkyl group, R represents a hydrogen atom or a lower alkyl group, Y represents a lower alkylene group, M represents a hydrogen atom, and -N.
H _3, an alkali metal atom or alkaline earth metal atom.

(2) Cationic Fluorosurfactant R _f CONHYN (R) (R ′) · HX R _f SO ₂ NHYN (R) (R ′) · HX

[Chemical 4]

[Chemical 5] In the above formula, R _f , R and Y are as defined above, R ′ represents a hydrogen atom or a lower alkyl group, and HX
Represents an acid, and X represents a halogen atom or an acid radical.

(3) Amphoteric fluorinated surfactant

[Chemical 6]

[Chemical 7] In the above formula, R _f , R and Y are as defined above.

(4) Nonionic fluorine-containing surfactant R _f OH

[Chemical 8]

[Chemical 9] In the above formula, R _f and R are as defined above,
n shows the number of 1-30. In addition, two or more kinds of the above-mentioned fluorine-containing surfactants may be appropriately used in combination, if desired.

Further, as a suitable commercially available fluorochemical surfactant, "Surflon S-" manufactured by Seimi Chemical Co., Ltd.
111 "(perfluoroalkylcarboxylate)," Surflon S-112 "(perfluoroalkyl phosphate)," Surflon S-113 "(perfluoroalkylcarboxylate)," Surflon S-121 "(perfluoro) Alkyl trimethyl ammonium salt), "Surflon S-1
31 "(perfluoroalkyl betaine)," Surflon S
-132 "(perfluoroalkyl betaine)" Surflon S-141 "(perfluoroalkylamine oxide)," Surflon S-145 "(perfluoroalkylethylene oxide adduct)," Surflon S-381 "
(Perfluoroalkyl-containing oligomer), "Surflon S-383" (Perfluoroalkyl-containing oligomer), "Surflon S-393" (Perfluoroalkyl-containing oligomer), "Surflon SC-101" (Perfluoroalkyl-containing oligomer), "Surflon S
C-105 "(perfluoroalkyl-containing oligomer)," Surflon KH-40 "(perfluoroalkylethylene oxide adduct) and" Surflon SA-
100 ”(perfluoroalkyl-containing special blended product) and the like are exemplified.

Further, as other suitable commercially available fluorochemical surfactants, "Florard FC-430" (fluorinated alkyl ester) and "Florard FC-431" (fluorinated alkyl ester) manufactured by Sumitomo 3M Limited are available. Etc., and "F-top EF-102" (perfluorosulfonate), "F-top EF-103" (perfluorosulfonate), "F-top EF-104" (perfluorosulfone) manufactured by Mitsubishi Materials Corporation. Acid salt), "F-top EF-122" (perfluoroalkylethylene oxide adduct), "F-top E"
F-351 "(fluorinated alkyl ester)," F-top EF-352 "(fluorinated alkyl ester),
Examples include “F-top EF-801” (fluorinated alkyl ester), “F-top EF-802” (fluorinated alkyl ester), “F-top EF-601” (fluorinated alkyl ester) and the like.

The above-mentioned organosilicon compound, ultraviolet absorbing compound, and fluorosurfactant are solutions using water or a water-soluble organic solvent as a solvent from the viewpoint of the efficiency of modifying the surface of the fluororesin molding and workability. , As a dispersion or suspension on the surface. As the solvent for the solution or the like, a mixture of water and a water-soluble organic solvent such as a lower alcohol (eg, methanol, ethanol, isopropanol, butanol, etc.) may be used. When used as an aqueous solution, a water-soluble organic solvent, for example, a lower alcohol such as isopropanol or the like may be appropriately blended in order to enhance the solubility of the organosilicon compound, the ultraviolet absorbing compound and the fluorosurfactant. .

The concentration of the solution or the like of the organic silicon compound using water and / or a water-soluble organic solvent as a solvent depends on the kind of the compound, the solubility in water and the like, the kind of the fluororesin to be treated, and the coexisting ultraviolet absorbing compound. It depends on the type and concentration of the fluorosurfactant and is not particularly limited, but is generally 0.05 to 10% by weight, preferably 0.
It is 1 to 5% by weight.

The concentration of the solution or the like of the ultraviolet absorbing compound is also the kind of the compound, the solubility in water, the kind of the fluororesin to be treated, and the kind and the concentration of the coexisting organosilicon compound and fluorine-containing surfactant. It depends on, but is not particularly limited to, generally 0.05 to 10% by weight,
It is preferably 0.1 to 5% by weight.

Further, the concentration of the above-mentioned fluorine-based surfactant in an aqueous solution or the like may be any concentration as long as it allows the above-mentioned organosilicon compound and ultraviolet absorbing compound to uniformly exist on the surface of the fluororesin molded article at a sufficient concentration. Although not particularly limited, it is generally 0.05 to 2% by weight, preferably 0.02% by weight.
It is 1 to 1% by weight.

Any method such as coating method, spraying method or dipping method may be used as the method for allowing the above-mentioned organosilicon compound, the ultraviolet absorbing compound and the aqueous solution of the fluorine-containing surfactant to exist on the surface of the fluororesin molding. Good. Further, after the aqueous solution or the like is allowed to exist on the surface of the fluororesin molding, a drying treatment may be performed before the irradiation with the ultraviolet laser light. Natural drying is sufficient for the drying treatment, but if desired, for example, 60 to
You may forcefully carry out at 150 degreeC. Due to the action of the fluorine-based surfactant, the organosilicon compound and the ultraviolet absorbing compound are uniformly present on the surface of the fluororesin molded article in a sufficient concentration.

In the present invention, the surface of the molded product is irradiated with an ultraviolet laser beam under the condition that the organosilicon compound, the ultraviolet absorbing compound and the fluorine-containing surfactant are present on the surface of the molded product of fluororesin. As the ultraviolet laser light, one having a wavelength of 400 nm or less is desirable, and an argon laser light, a krypton ion laser light, N
Examples thereof include d: YAG laser light, N ₂ laser light, dye laser light, and excimer laser light. Excimer laser light of 193 to 308 nm is particularly preferable. Particularly, KrF excimer laser light (wavelength: 248 nm), ArF excimer laser light (wavelength: 193 nm) and XeCl excimer laser light (308 nm), which can stably obtain high output for a long time, are preferable. Irradiation of excimer laser light is usually performed at room temperature in the air, but may be performed in an oxygen atmosphere. The irradiation conditions of the excimer laser light depend on the type of fluororesin and the desired degree of surface modification, but the general irradiation conditions are as follows. Fluence: About 20 mJ / cm ² / pulse or more Incident energy: About 0.1 J / cm ² or more Shot number: About 100 or less

Particularly suitable KrF excimer laser light, Ar
The commonly used irradiation conditions of F excimer laser light and XeCl excimer laser light are as follows. KrF fluence: 30 to 500 mJ / cm ² / pulse incident energy: 0.2 to 2.0 J / cm ² shot number: 1 to 20 ArF fluence: 20 to 150 mJ / cm ² / pulse incident energy: 0.1 to 1. 0 J / cm ² shot number: 1-20 XeCl fluence: 100-600 mJ / cm ² / pulse incident energy: 0.1-2.0 J / cm ² shot number: 1-20

[0026]

EXAMPLES The present invention will be described below with reference to examples.Example 1 To a 1% by weight aqueous solution of anthraquinonecarboxylic acid,
Freon S-132 "(commercially available from Seimi Chemical Co., Ltd.
Product; perfluoroalkyl betaine) at a concentration of 1% by weight
And then add (triphenylsilyl) acetylene to 1
Prepare pretreatment liquid by dispersing at concentration of wt%
did. Applicator (Yoshimitsu Seiki Co., Ltd. "YA
Type applicator ”)
Apply on the surface of the film (thickness: 100 μm)
(Thickness: 50 μm), Kr for a coating film that has been naturally dried for about 30 minutes
Irradiated with F excimer laser light (irradiation amount: 0.6 J /
cm ^Two). Silicone rubber of the obtained surface modified film
Adhesion durability to was evaluated by the following test.Adhesion durability test Test film (150 mm × 150 mm × 100 μm)
And aluminum plate (120mm × 120mm × 1m
m) is a one-component addition type silicone rubber (volume specific resistance: 1 x
10^ThreeΩ ・ cm) to bond the laminated body
Heating at 120 ° C for 30 minutes under load
Therefore, an adhesion test piece was prepared. The obtained adhesion test piece is 2
It is left in a constant temperature bath at 00 ° C and the adhesive test piece is
When the film is removed from the warm bath and the film is peeled off,
Check whether the rubber sticks to the film and peels off
To evaluate the adhesion durability. Prepared in Example 1
The tested film showed good adhesion after 2000 hours
It was

Comparative Example 1 A test film prepared in the same manner as in Example 1 except that (triphenylsilyl) acetylene was not dispersed in the pretreatment liquid was subjected to an adhesion durability test.
After 0 hours, the silicone rubber did not show peeling off.

Example 2 To a 1 wt% ethanol solution of fluorene, "Florard FC-430" (commercially available from Sumitomo 3M Ltd .; fluorinated alkyl ester) was added at a concentration of 1 wt%, and then phenylsilane was added to 1 wt%. A pretreatment liquid was prepared by adding it at a concentration of wt%. The pretreatment liquid is applied onto the surface of a PFA film (thickness: 100 μm) (applying thickness: 25 μm) using an applicator (“YA type applicator” manufactured by Yoshimitsu Seiki Co., Ltd.) and naturally dried for about 30 minutes. The coating film was irradiated with KrF excimer laser light (irradiation amount: 0.4 J / cm ² ). The surface-modified film obtained was used as a one-component addition type silicone rubber (heat conductivity: 4.2 W
/ M · ° C.) and subjected to the above-mentioned adhesion durability test, it showed good adhesion even after 2000 hours.

Comparative Example 2 A test film prepared in the same manner as in Example 2 except that phenylsilane was not added to the pretreatment liquid was subjected to an adhesion durability test. After about 1000 hours, the silicone rubber was peeled off. No longer shows.

Example 3 1% by weight of "Florard FC-430" (commercially available from Sumitomo 3M; fluorinated alkyl ester) was added to a 1% by weight ethanol solution of 9-acetylanthracene.
Then, the pretreatment liquid was prepared by adding phenylsilane at a concentration of 1% by weight. The pretreatment liquid is applied onto the surface of the PTFE film (thickness: 100 μm) using an applicator (“YA type applicator” manufactured by Yoshimitsu Seiki Co., Ltd.) (coating thickness: 25 μm).
m), the coating film naturally dried for about 30 minutes was irradiated with KrF excimer laser light (irradiation amount: 0.6 J / cm ² ).
The obtained surface-modified film was subjected to the above-mentioned adhesion durability test using a one-component addition type silicone rubber (volume specific resistance: 1 × 10 ³ Ω · cm), and showed good adhesion even after 2000 hours. It was

Comparative Example 3 A test film prepared in the same manner as in Example 3 except that phenylsilane was not added to the pretreatment liquid was subjected to an adhesion durability test. After about 1500 hours, the silicone rubber was peeled off. No longer shows.

When the surface-modified films obtained in Examples 1 to 3 were subjected to surface analysis by XPS (X-ray photoelectron spectroscopy analysis), introduction of silicon atoms and increase in oxygen atom amount were confirmed.

[0033]

EFFECTS OF THE INVENTION According to the present invention, it is possible to impart high adhesion durability to a fluororesin molded article, particularly to rubber, especially high conductivity silicone rubber. In this case, excellent heat resistance, which is a characteristic of fluororesin,
The chemical resistance and electrical characteristics are not impaired.
Therefore, the surface-modified fluororesin molded article according to the present invention is, for example, various rollers (eg, charging roller, developing roller, transfer roller, fixing roller, pressure roller) used in electronic copying machines, laser beam printers and the like. It can be effectively and widely used in the field of rollers and the like).

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08J 7/00 C08J 7/06

Claims (8)

(57) [Claims] 1. A solution, dispersion or suspension containing an organosilicon compound, an ultraviolet absorbing compound and a fluorosurfactant is adhered to the surface of a fluororesin molding, and the adhered surface is irradiated with an ultraviolet laser beam. A method for modifying the surface of a fluororesin molded article, which comprises: 2. The organosilicon compound is selected from the group consisting of (triphenylsilyl) acetylene, phenylsilane, tetraphenoxysilane, triphenylsilane, tribenzylsilane, allyltriphenylsilane, triphenylvinylsilane and phenyltriethoxysilane. The method according to claim 1, wherein the compound is one or more compounds. 3. The method according to claim 1, wherein the ultraviolet absorbing compound is an aromatic ultraviolet absorbing compound. 4. The aromatic ultraviolet absorbing compound is an aromatic hydrocarbon, an aromatic carboxylic acid and its salt, an aromatic aldehyde, an aromatic alcohol, an aromatic amine and its salt, or an aromatic sulfonic acid. The method according to claim 2, which is one or more compounds selected from the group consisting of: and salts thereof and phenols. 5. The fluorosurfactant is a perfluoroalkyl phosphate, a perfluoroalkyl carboxylate,
The method according to claim 1, which is one or more surfactants selected from the group consisting of perfluoroalkyltrimethylammonium salts, perfluoroalkylbetaines, perfluoroalkylamine oxides and perfluoroalkylethylene oxide adducts. 6. The method according to claim 1, wherein the ultraviolet laser light is ArF excimer laser light, KrF excimer laser light or XeCl excimer laser light. 7. The method according to claim 1, wherein the surface of the fluororesin molding is coated with an aqueous solution of an organosilicon compound, an ultraviolet absorbing compound and a fluorosurfactant. 8. The method according to claim 1, wherein the surface of the fluororesin molding is coated with a lower alcohol solution of an organosilicon compound, an ultraviolet absorbing compound and a fluorosurfactant.