JP4068786B2 - Method for forming cured coating film - Google Patents

Description

[0001]
[Technology to which the invention belongs]
The present invention is excellent in antifouling properties, water and oil repellency, has excellent characteristics such as chemical resistance and weather resistance, which are the characteristics of fluororesin, and can be cured by light or heat in one liquid. The present invention relates to a fluorine-containing copolymer containing, a process for producing the same, a fluororesin paint containing the same as a main component, and a varnish.
[0002]
[Prior art]
Solvent-soluble fluororesin coatings are generally obtained by copolymerizing hydroxyalkyl vinyl ether and fluoroolefin, and optionally alkyl vinyl ether, alkyl vinyl ester and the like. The coating material based on such a fluorine-containing copolymer contains about 50% of a hydrocarbon monomer in order to obtain solubility in a general organic solvent. Therefore, the fluorine content in the fluororesin is lowered, and the coating film properties such as water / oil repellency and stain resistance required for the fluororesin cannot be sufficiently obtained. On the other hand, water and oil repellency is improved by mixing a small amount of an organic silicon compound such as silicone oil with the fluorine-containing copolymer. However, it is difficult to maintain water and oil repellency characteristics over a long period of time. Furthermore, depending on the application, silicone oil may bleed out from the surface of the coating film, and silicone oil cannot be used. JP-A-5-17535 discusses a copolymer of a fluorine-containing monomer and a monomer containing a silyl group. The film properties such as water / oil repellency cannot be sufficiently obtained.
[0003]
The hydroxyl group-containing fluorine-containing copolymer can be cured at room temperature, but two liquids of a main agent and a curing agent must be mixed immediately before use. This is not convenient for work, and attention must be paid to the pot life.
[0004]
[Problems to be solved by the invention]
The object of the present invention is to provide a fluorine-containing copolymer that solves the above-mentioned problems, that is, it has excellent characteristics (chemical resistance, weather resistance, etc.) of a fluororesin coating film, Provides a fluorine-containing copolymer containing a novel double bond that is excellent in oil repellency, antifouling properties, and repeated decontamination, and can be cured by light or heat in one liquid, and a method for producing the same, and further comprising them And providing fluorine-based paints, varnishes and the like.
[0005]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have shown a fluoroolefin, a reactive silicone oil represented by the general formula (1) or (2), and a general formula (3). A double bond is introduced into the fluorine-containing copolymer by a reaction between the hydroxyl group-containing fluorine-containing copolymer [A] and the unsaturated isocyanate [B], which is an essential component. It has been found that a fluorine-containing copolymer containing a new double bond produced by this method is excellent in long-term water and oil repellency, antifouling properties and repeated decontamination.
[0006]
_{^{R 1 - [Si (CH 3}} ) 2 -O] n -Si (CH 3) 2 -R 2 (1)
(Here, R ¹ represents an alkyl group having 1 to 6 carbon atoms, or — (CH ₂ ) _r —OOC (CH ₃ ) C═CH ₂ or —CH═CH _2. R ² represents — (CH ₂ ) _r —OOC (CH ₃ ) C═CH ₂ or —CH═CH ₂ , n represents an integer of 1 to 420, and r represents an integer of 1 to 6)
[0007]
R ² —Si [OSi (CH ₃ ) ₃ ] ₃ (2)
[0008]
_{CH 2 = CH (CH 2)} m -O-R 3 -OH (3)
(Here, R ³ represents an alkylene group having 1 to 6 carbon atoms or a cyclohexyl group. M represents an integer of 0 to 10.)
That is, in the present invention, 15 to 85 mol% of a fluoroolefin, 0.001 to 30 mol% of a reactive silicone oil represented by the general formula (1) or (2) as a polymerization unit, and a general formula (3 Hydroxyl-containing fluorine-containing copolymer obtained by copolymerization with any other copolymerizable monomer as required, with 1-50 mol% of the hydroxyl-containing unsaturated ether represented by It is produced by the reaction of coalescence [A] and unsaturated isocyanate [B], and contains double bonds with excellent water and oil repellency, antifouling properties, repeated decontamination, chemical resistance, and weather resistance over a long period of time. The fluorine-containing copolymer is provided.
[0009]
In addition to the above polymerized units, the hydroxyl group-containing fluorine-containing copolymer [A] contains one or more polymerized units selected from alkyl vinyl ethers, alkyl allyl ethers, methacrylic acid esters and acrylic acid esters. The present invention relates to a fluorine-containing copolymer containing a double bond, which is produced by a reaction between a copolymer and an unsaturated isocyanate [B].
[0010]
In the hydroxyl group-containing fluorine-containing copolymer [A] of the present invention, the fluoroolefin is an olefin having one or more fluorine atoms in the molecule, such as vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene, Hexafluoropropylene and the like are preferred. These fluoroolefins may be used alone or in combination of two or more, but a combination of vinylidene fluoride and tetrafluoroethylene is particularly preferable. The combination ratio (VDF / TFE) of vinylidene fluoride and tetrafluoroethylene is preferably 0.05 / 1 to 2.0 / 1. A more preferable range for achieving the object of the present invention is 0.1 / 1 to 1.5 / 1.
[0011]
The reactive silicone oil represented by the general formula (1) or (2) is composed of polydimethylsiloxane having a methacrylic modification at one end, polydimethylsiloxane having an acrylic modification at one end, and a polydimethylsiloxane having a methacrylic modification at both ends. Etc. are suitable. These reactive silicone oils may be used alone or in combination of two or more. The number average molecular weight of these reactive silicone oils is preferably 200 to 30,000.
[0012]
As the reactive silicone oil, silicone oils of the following formulas (4), (5), (6) and (7) are particularly preferable.
[0013]
_{CH 2 = C (CH 3)} -COO-C 3 H 6 -Si (CH 3) 2 - [O-Si (CH 3) 2] p -R 4 (4)
(Here, R ⁴ represents an alkyl group having 1 to 6 carbon atoms. P represents an integer of 1 to 250.)
[0014]
_{CH 2 = CH-COO-C} 3 H 6 -Si (CH 3) 2 - [O-Si (CH 3) 2] r -R 5 (5)
(Here, R ⁵ represents an alkyl group having 1 to 6 carbon atoms. R represents an integer of 1 to 250.)
[0015]
R ⁶ —C ₃ H ₆ —Si (CH ₃ ) ₂ — [O—Si (CH ₃ ) ₂ ] _q —C ₃ H ₆ —R ⁶ (6)
(Here, R ⁶ represents —OOC (CH ₃ ) C═CH _2. Q represents an integer of 1 to 250.)
[0016]
_{CH 2 = C (CH 3)} COO-C 3 H 6 Si [OSi (CH 3) 3] 3 (7)
Specific examples of the hydroxyl group-containing unsaturated ether represented by the general formula (3) include hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, ethylene glycol monoallyl ether, cyclohexyl vinyl ether, 4-hydroxycyclohexyl vinyl ether, 3-allyloxy-1,2-propanediol, glycerol α-monoallyl ether and the like are preferable. These hydroxyl group-containing unsaturated ethers may be used alone or in combination of one or more.
[0017]
Specific examples of the alkyl vinyl ether include ethyl vinyl ether, isopropyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, cyclohexyl vinyl ether, octadecyl vinyl ether and the like.
[0018]
Specific examples of the alkyl allyl ether include ethyl allyl ether, butyl allyl ether, cyclohexyl allyl ether, isobutyl allyl ether, n-propyl allyl ether and the like.
[0019]
Specific examples of the acrylate ester include methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, and the like.
[0020]
Specific examples of the methacrylate ester include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, glycidyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate. Etc.
[0021]
The hydroxyl group-containing fluorine-containing copolymer [A] of the present invention can form a coating with excellent water and oil repellency, antifouling properties, repeated decontamination, chemical resistance, and weather resistance over a long period of time. Furthermore, in addition to these units, other copolymerizable monomer units may be included within a range not exceeding 20 mol% depending on the purpose of use.
[0022]
Examples of the copolymerizable monomer include olefins such as ethylene and propylene, haloolefins such as vinyl chloride and vinylidene chloride, and alkanecarboxylic acids such as vinyl acetate, vinyl n-butyrate, vinyl isobutyrate, and vinyl propionate. And esters of vinyl alcohol.
[0023]
When the hydroxyl group-containing fluorine-containing copolymer [A] contains less than 15 mol% of the polymerized unit fluoroolefin, it is not preferable because sufficient stain resistance cannot be obtained when used as a paint base. Moreover, when more than 85 mol%, the solubility with respect to various solvents falls and it is unpreferable. More preferably, it is 30-80 mol%.
[0024]
When the ratio of the reactive silicone oil represented by the general formula (1) or (2) is less than 0.001 mol%, it is not preferable because sufficient water / oil repellency and antifouling properties cannot be obtained for a long time. On the other hand, when it is more than 30 mol%, sufficient chemical resistance and weather resistance cannot be obtained, which is not preferable. Further, when a polymer having a large molecular weight (n = 200 to 420) is polymerized, the ratio cannot be increased in production. For these reasons, the ratio is more preferably 0.005 to 25 mol%.
[0025]
When the hydroxyl group-containing unsaturated ether represented by the general formula (3) is less than 1 mol%, the double bond amount is lowered and sufficient curing does not occur, and the chemical resistance and solvent resistance of the cured coating film are lowered. It is not preferable. On the other hand, when it is more than 50 mol%, the fluorine content in the fluorine-containing copolymer is decreased, and sufficient chemical resistance and weather resistance cannot be obtained, which is not preferable.
[0026]
The hydroxyl group-containing fluorine-containing copolymer [A] can be produced by copolymerizing a predetermined proportion of a monomer mixture using a polymerization initiator.
[0027]
As the polymerization initiator in the synthesis of the hydroxyl group-containing fluorine-containing copolymer [A], an oil-soluble or water-soluble one is appropriately used depending on the polymerization type and the type of solvent used as desired.
[0028]
Examples of the oil-soluble initiator include peroxyester type peroxides such as t-butyl peroxyisobutyrate and t-butyl peroxyacetate, and dialkyl peroxydicarbonates such as diisopropyl peroxydicarbonate and dinormalpropyl peroxydicarbonate. Oxydicarbonate, benzoyl peroxide, azobisisobutyronitrile and the like are used.
[0029]
Examples of the water-soluble initiator include a persulfate such as potassium persulfate, hydrogen peroxide, or a redox initiator comprising a combination of these with a reducing agent such as sodium bisulfite and sodium thiosulfate, and a small amount thereof. Inorganic initiators in which iron, ferrous salt, silver nitrate, and the like coexist, and dibasic acid organic initiators such as succinic acid peroxide, diglutaric acid peroxide, and monosuccinic acid peroxide are used.
[0030]
The amount of these polymerization initiators to be used is appropriately selected according to the type, copolymerization reaction conditions, and the like, but is 0.005 to 5% by weight, preferably 0.1%, based on the total amount of monomers normally used. It is selected in the range of ˜2% by weight.
[0031]
There is no particular limitation on the polymerization method in the synthesis of the hydroxyl group-containing fluorine-containing copolymer [A]. For example, bulk polymerization method, suspension polymerization method, emulsion polymerization method, solution polymerization method and the like can be used. Solution polymerization methods using ketones, acetate esters such as butyl acetate, aromatic hydrocarbons such as xylene, alcohols such as t-butanol, halogenated saturated hydrocarbons having one or more fluorine atoms, etc. as solvents An emulsion polymerization method in an aqueous solvent is preferred.
[0032]
Particularly preferable solvents for obtaining the hydroxyl group-containing fluorine-containing copolymer [A] of the present invention by a solution polymerization method include ethyl acetate, butyl acetate, xylene, toluene, and methyl ethyl ketone.
[0033]
In the case of copolymerization in an aqueous solvent (emulsion polymerization method, suspension polymerization method), a suspension or emulsifier is usually used as a dispersion stabilizer, and a basic buffer is added to the reaction solution during polymerization. It is desirable that the pH value is 4 or more, preferably 6 or more.
[0034]
The reaction temperature in each of the copolymerization reactions is appropriately selected depending on the type of the polymerization initiator and the polymerization medium, usually within a range of −30 ° C. to 150 ° C. For example, when copolymerization is performed in a solvent, it is usually selected in the range of 0 ° C to 100 ° C, preferably 10 ° C to 90 ° C. The reaction pressure is not particularly limited, but is usually selected in the range of 1 to 100 kg / cm ² , preferably 1 to 50 kg / cm ² . Further, the copolymerization reaction can be carried out by adding an appropriate chain transfer agent.
[0035]
The reaction of the hydroxyl group-containing fluorine-containing copolymer [A] and the unsaturated isocyanate [B] is not particularly limited, but the unsaturated isocyanate is added to a solution in which the hydroxyl group-containing fluorine-containing copolymer is dissolved in a solvent. It is preferable to add it while dropping and to carry out under stirring.
[0036]
The reaction ratio of the hydrogen group-containing fluorine-containing copolymer [A] and the unsaturated isocyanate [B] is selected in the range of 0.1 to 1 in terms of the ratio of isocyanate group / hydroxyl group.
[0037]
When the ratio of isocyanate group / hydroxyl group is less than 0.1, the amount of double bonds is lowered and sufficient curing does not occur, which is not preferable because the chemical resistance and solvent resistance of the cured coating film are lowered. Moreover, when more than 1, unreacted unsaturated isocyanate remains and there exists a possibility that a coating-film characteristic may be reduced.
[0038]
Specific examples of the unsaturated isocyanate include 2-isocyanate ethyl methacrylate, 2-isocyanate ethyl acrylate, 4-isocyanate butyl methacrylate, 4-isocyanate butyl acrylate, a reaction product of 1 mol of an unsaturated monoalcohol and 1 mol of a diisocyanate compound, Examples include a reaction product of 2 mol of an unsaturated monoalcohol and 1 mol of a triisocyanate compound. Specific examples of the unsaturated monoalcohol include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxybutyl methacrylate, hydroxybutyl acrylate, and allyl alcohol.
[0039]
Specific examples of the diisocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, dicyclohexylmethane diisocyanate and the like. Specific examples of the triisocyanate compound include isocyanurate-bound HDI, isocyanurate-bound IPDI, TMP-modified HDI, and TMP-modified IPDI.
[0040]
The reaction temperature at this time is selected in the range of 10 to 130 ° C, preferably 25 to 85 ° C. When the temperature is lower than 10 ° C., the reaction does not proceed sufficiently. When the temperature is higher than 130 ° C., gelation tends to occur during the reaction, which is not preferable.
[0041]
The solvent used for the reaction is preferably a ketone such as methyl ethyl ketone, an acetate such as butyl acetate, an aromatic hydrocarbon such as xylene. Since unsaturated isocyanate is used, if a solvent having a hydroxyl group such as water or alcohol is used, the reaction between the hydroxyl group-containing fluorine-containing copolymer [A] and unsaturated isocyanate [B] does not proceed. These solvents having a hydroxyl group are not preferred.
[0042]
It is preferable to use an organic tin compound such as dibutyltin dilaurate as a reaction catalyst.
[0043]
Since the fluorine-containing copolymer containing a double bond of the present invention can be cured by light irradiation, curing can be completed in a short time. Therefore, it is very useful for coating on a substrate such as plastic which cannot be heated very much. Moreover, when trying to harden a hydroxyl-containing fluorine-containing copolymer at normal temperature, a hardening | curing agent must be mixed at the time of use, and it is not easy on operation. On the other hand, the fluorine-containing copolymer containing a double bond of the present invention is one liquid and can be used without mixing a curing agent, which is very useful in operation.
[0044]
The fluorine-containing copolymer containing a double bond obtained by such a method can be cured by light irradiation or heat.
[0045]
Examples of the photocuring initiator include benzoin ether, benzophenone, 1 -hydroxy -cyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-monforinopropanone-1, 2-benzyl-2. Dimethylamino-1- (4-morpholinophenyl) -butanone-1,2,2-dimethoxy-1,2-diphenylethane-1-one and the like are used.
[0046]
As the thermosetting initiator, benzoyl peroxide, azobisisobutyronitrile, t-butylperoxy-2-ethylhexanate, t-butylperoxyisopropyl monocarbonate, or the like is used.
[0047]
Various solvents can be used for producing a curable fluororesin coating material mainly composed of the fluorine-containing copolymer containing a double bond of the present invention, for example, aromatic carbonization such as xylene and toluene. Examples include hydrogen esters, acetate esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, glycol ethers such as ethyl cellosolve, and various commercially available thinners. Ethyl acetate, butyl acetate, xylene Toluene is particularly preferred. Moreover, it is possible to add a commercially available photocurable resin etc. as needed, The fluorine-containing copolymer containing the double bond of this invention with respect to these other resins is 5 to 80 weight% in a coating material. In particular, it is preferably used by adjusting so as to contain 20 to 60% by weight.
[0048]
Mixing of the fluorine-containing copolymer containing a double bond of the present invention and a solvent should be carried out using various equipment used for normal coating, such as a ball mill, paint shaker, sand mill, triple roll mill, kneader. I can do it. At this time, a pigment, a dispersion stabilizer, a viscosity modifier, a leveling agent and the like can be added as necessary.
[0049]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
[0050]
[Example 1]
After degassing in an autoclave (withstand pressure of 100 kg / cm ² ) with a stainless steel stirrer with an internal volume of 1 L, 96 g of vinylidene fluoride (hereinafter abbreviated as VDF), 84 g of tetrafluoroethylene (hereinafter abbreviated as TFE), ethyl vinyl ether (hereinafter referred to as “VDF”) 14.9 g of EVE), 52.2 g of hydroxybutyl vinyl ether (hereinafter abbreviated as HBVE), 10.5 g of methacryl-modified silicone oil A (number average molecular weight of about 3500) represented by the following structural formula, 400 g of butyl acetate, and t- 1.3 g of butyl peroxypivalate was added, and the internal temperature was raised to 60 ° C. while stirring.
[0051]
_{CH 2 = C (CH 3)} -COO-C 3 H 6 -Si (CH 3) 2 - [O-Si (CH 2) 2] 44 -OSi (CH 3) 3
Thereafter, the reaction was continued with stirring, and stirring was stopped after 20 hours to complete the reaction. The obtained copolymer was isolated by drying under reduced pressure. The copolymer yield was 242 g, and the copolymer yield was 94%. The hydroxyl value of the obtained hydroxyl group-containing fluorine-containing copolymer (hereinafter referred to as [A-1]) measured by an acetylation method with acetic anhydride was 104 mg KOH / g resin, and the fluorine content by a combustion method was 47 wt%. .
[0052]
Next, in a 1 L round bottom three-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a calcium chloride tower in a dark place, 600 g of the obtained 30% butyl acetate solution of [A-1] and hydroquinone monomethyl ether 0 .05 g was added. While maintaining the temperature at 40 ° C. and stirring, a mixed solution containing 51.8 g of 2-isocyanatoethyl methacrylate (hereinafter referred to as [B-1]) and 17.3 g of butyl acetate was dropped little by little with a dropping funnel. After completion of the dropping, stirring was continued for 2 hours to obtain a fluorinated copolymer containing a double bond.
[0053]
The infrared absorption spectrum of the reaction solution was measured. As a result, it was confirmed that the absorption of isocyanate groups at 2,260 cm ⁻¹ disappeared completely. Thereby, it was confirmed that reaction of the hydroxyl group of [A-1] and the isocyanate group of [B-1] advanced. The number average molecular weight measured by GPC of the obtained fluorine-containing copolymer containing a double bond was 1.9 × 10 ⁴ . The coating properties of the cured coating film of this copolymer were examined by the following method. The results are shown in [Table 1].
[Adhesion to Base Material] 67 g of the 30% butyl acetate solution, 80 g of Ebecry 1810 (manufactured by Daicel UC), and 2-methyl-1- [4- (methylthio) phenyl] -2-monforinoprop Non-1 (Ciba Geigy Co., Ltd.) 0.3g was added, it apply | coated with the applicator on the JISG-3141 steel plate, and after drying for 3 minutes at 80 degreeC, the ultraviolet-ray of 270mJ / cm < ² > was irradiated in the air. The obtained 25-micrometer-thick test piece was measured by JIS-K5400 6.15 (Gobain cello tape (trademark) test).
[Pencil hardness] According to JIS-K5400 6.14 (pencil scratch test).
[Acid Resistance] Visually observe the appearance of the coating film after a 24-hour spot test using a 10% HCl solution.
[0054]
：: No abnormality ○: Almost no change Δ: Slightly attacked X: Slightly affected [Alkali resistance] The appearance of the coating film after a 24-hour spot test with a 10% NaOH solution is visually observed.
[0055]
◎: No abnormality ○: Almost no change △: Slightly attacked ×: Soiled [oil-based magic repellency] Oil-based Magic (registered trademark) (Black / Red / Magic Ink product name) paints the surface of the coating to repel it. evaluate. Further, this coating film is left at room temperature for 1 hour and then removed by dry wiping. The repellency of the coating film surface after repeating this 20 times is evaluated.
[0056]
◎: Repels well ○: Repels △: Slightly repels ×: Does not repel at all [Repeatability of oil-based magic] Paint the paint film surface with oil-based magic (black, red, magic ink product name), leave it at room temperature for 1 hour, and then wipe dry Remove. Furthermore, the removability of the coating film surface after repeating this 20 times is evaluated.
[0057]
A: No trace at all O: Very slight trace Δ: Quite trace X: Trace remains completely [Water repellency] The contact angle (unit: degree) of water was evaluated.
[0058]
[Examples 2-3]
Using the monomers shown in [Table 1], a copolymer was produced in accordance with the operation of the above Example, and these characteristics were similarly examined. The results are shown in [Table 1].
[0059]
[Example 4]
After deaeration into an autoclave (withstand pressure of 100 kg / cm ² ) with a stainless steel stirrer with an internal volume of 1 L, VDF 50 g, TFE 78 g, butyl vinyl ether (hereinafter abbreviated as BVE) 52.0 g, HBVE 45.2 g, represented by the following structural formula 54.6 g of methacryl-modified silicone oil C (molecular weight about 420), 400 g of toluene, and 1.4 g of t-butyl peroxypivalate were added, and the internal temperature was raised to 60 ° C. while stirring.
[0060]
Embedded image
_{CH 2 = C (CH 3)} -COO-C 3 H 6 -Si- [OSi (CH 3) 3] 3
Thereafter, the reaction was continued with stirring, and stirring was stopped after 20 hours to complete the reaction. The obtained copolymer was isolated by drying under reduced pressure. The copolymer yield was 260 g, and the copolymer yield was 93%. The obtained hydroxyl group-containing fluorine-containing copolymer (hereinafter referred to as [A-4]) had a hydroxyl value of 86 mgKOH / g resin and a fluorine content of 32 wt%.
[0061]
Next, in a 1 L round bottom three-necked flask equipped with a stirrer, reflux condenser, dropping funnel and calcium chloride tower in a dark place, 600 g of 30% butyl acetate solution of [A-4] and 0.05 g of hydroquinone monomethyl ether were added. I put it in. While stirring at a temperature of 40 ° C., a mixed solution containing 30.0 g of [B-1] and 10.0 g of toluene was dropped little by little with a dropping funnel. After completion of the dropping, stirring was continued for 2 hours to obtain a fluorinated copolymer containing a double bond.
[0062]
The infrared absorption spectrum of the reaction solution was measured, and it was confirmed that the reaction between the hydroxyl group of [A-4] and the isocyanate group of [B-1] proceeded. The number average molecular weight measured by GPC of the obtained fluorine-containing copolymer containing a double bond was 1.9 × 10 ⁴ . The cured coating film characteristics of this copolymer were examined in the same manner as in Example 1. The results are shown in [Table 1].
[0063]
[Example 5]
Using the monomers shown in [Table 1], a copolymer was produced in accordance with the operation of the above example, and these characteristics were similarly examined. The results are shown in [Table 1].
[0064]
[Comparative Example 1]
After deaeration in an autoclave with a stainless steel stirrer with an internal volume of 1 L (pressure resistance 100 kg / cm ² ), VDF 96 g, TFE 84 g, EVE 15.1 g, HBVE 52.2 g, butyl acetate 400 g, and t-butyl peroxypivalate 1.2 g The internal temperature was raised to 60 ° C. while stirring. Thereafter, the reaction was continued with stirring, and stirring was stopped after 20 hours to complete the reaction. The obtained copolymer was isolated by drying under reduced pressure. The copolymer yield was 230 g, and the copolymer yield was 93%. The obtained hydroxyl group-containing fluoropolymer (hereinafter referred to as [A-6]) had a hydroxyl value of 110 mg KOH / g resin and a fluorine content of 49 wt%.
[0065]
Next, in a 1 L round bottom three-necked flask equipped with a stirrer, reflux condenser, dropping funnel and calcium chloride tower in a dark place, 600 g of 30% butyl acetate solution of [A-6] and 0.05 g of hydroquinone monomethyl ether were added. I put it in. While maintaining the temperature at 40 ° C. and stirring, a mixed solution containing 54.7 g of [B-1] and 23.4 g of butyl acetate was added dropwise little by little. After completion of the dropping, stirring was continued for 2 hours to obtain a fluorinated copolymer containing a double bond.
[0066]
The infrared absorption spectrum of the reaction solution was measured. As a result, it was confirmed that the absorption of isocyanate groups at 2,260 cm ⁻¹ disappeared completely. Thereby, it was confirmed that reaction of the hydroxyl group of [A-6] and the isocyanate group of [B-1] advanced. The number average molecular weight measured by GPC of the obtained fluorine-containing copolymer containing a double bond was 1.9 × 10 ⁴ . The coating film characteristics of the cured coating film of this copolymer were examined in the same manner as in Example 1. The results are shown in [Table 1].
[0067]
[Comparative Example 2]
To the coating composition prepared in Comparative Example 1, 5% TSF410 [manufactured by Toshiba Silicone Co., Ltd.] was added to the solid content of the composition, and test pieces were prepared in the same manner as in the above Comparative Example. I investigated. The results are shown in [Table 1].
[0068]
[Table 1]

Claims (1)

As polymerized units, 15 to 85 mol% of fluoroolefin, 0.001 to 30 mol% of reactive silicone oil represented by general formula (1) or (2), and hydroxyl group-containing unsaturation represented by general formula (3) A fluorine-containing copolymer produced by a reaction between a hydroxyl group-containing fluorine-containing copolymer [A] comprising 1 to 50 mol% of ether and an unsaturated isocyanate [B] and containing a double bond A method of forming a coating film, which comprises coating a polymer on a substrate and curing it by light irradiation or heat.
_{^{R 1 - [Si (CH 3}} ) 2 -O] n -Si (CH 3) 2 -R 2 (1)
(Here, R ¹ represents an alkyl group having 1 to 6 carbon atoms, or — (CH ₂ ) _r —OOC (CH ₃ ) C═CH ₂ or —CH═CH _2. R ² represents — (CH ₂ ) _r —OOC (CH ₃ ) C═CH ₂ or —CH═CH ₂ , n represents an integer of 1 to 420, and r represents an integer of 1 to 6)
R ² —Si [OSi (CH ₃ ) ₃ ] ₃ (2)
_{CH 2 = CH (CH 2)} m -O-R 3 -OH (3)
(Here, R ³ represents an alkylene group having 1 to 6 carbon atoms or a cyclohexyl group. M represents an integer of 0 to 10.)