Antifouling coating composition.

Field of the Invention

0001This invention relates to an antifouling composition capable of forming a coating layer excellent in weatherability and antifouling properties and articles partly or wholy coated with the composition.

Background of the Invention

0002Known coating compositions having good weatherability include those containing a copolymer of fluoro-olefin with vinyl ethers such as cyclohexylvinyl ether, alkylvinyl ether, hydroxyalkylvinyl ether and the like (e.g. Japanese Unexamined Patent Publication No.34107/1982).

0003However, these coating compositions have the drawbacks of having little antifouling properties and, when applied to the exterior wall boads or walls of houses, for example, the coated surfaces are prone to be stained with rain drops or trickles, metal rust, contaminants from exhaust fumes from automobiles, soils, etc., resulting in impaired appearance thereof. Further, when these compositions are applied to household electric appliances such as refrigerator, television set, microwave range, surfaces are easily stained with oil or grease, dirt from the havds, cigarrette fume, marking pen, crayon, etc. which are difficult to remove.

0004It is also known that (meth)acrylate copolymers having long-chain fluoroalkyl group as side chain show excellent water- and oil-repellent and antifouling properties. Nevertheless, these copolymers have the drawbacks of being poor in weatherability and chemical resistance and easily degraded in oil repellency and antifouling property because the copolymers have a relatively low molecular weight of less than 10,000 and are not cross-linked.

Summary of the Invention

0005An object of the invention is to provide a coating composition capable of forming a coat excellent both in weatherability and antifouling properties.

0006Another object of the invention is to provide an article having a coated layer excellent in weatherability and antifouling properties.

0007Other object and features of the invention will become apparent from the following description.

0008The present invention provides the following antifouling coating compositions.

0009(1) An antifouling coating composition (hereinafter referred to as "composition A") comprising a photopolymerization initiator or thermal polymerization initiator and a fluorine-containing (meth)acrylate represented by the formula (1) <chemistry id="chem0001" num="0001"><img file="EP0337474A2_D0001.tif" /></chemistry> wherein X is hydrogen atom, fluorine atom, chlorine atom or methyl, Y is alkylene having 1 to 3 carbon atoms, a group -CH₂CH₂N(R)SO₂- (wherein R is alkyl having 1 to 4 carbon atoms), a group -CH₂CH(OZ)CH₂- (wherein Z is a hydrogen atom or acetyl) or a group <chemistry id="chem0002" num="0002"><img file="EP0337474A2_D0002.tif" /></chemistry> and Rf is fluoroalkyl having 6 to 15 carbon atoms or fluoroalkyl having 5 to 21 carbon atoms and containing 1 to 5 oxygen atoms in the carbon ring provided that the oxygen atoms are not present adjacent to one another.

0010(2) An antifouling coating composition (hereinafter referred to as "composition B") comprising a polymer containing a structural unit represented by the formula (2) <chemistry id="chem0003" num="0003"><img file="EP0337474A2_D0003.tif" /></chemistry> wherein X is hydrogen atom, fluorine atom, chlorine atom or methyl, Y is alkylene having 1 to 3 carbon atoms, a group -CH₂CH₂N(R)SO₂- (wherein R is alkyl having 1 to 4 carbon atoms), a group -CH₂CH(OZ)CH₂- (wherein Z is a hydrogen atom or acetyl) or a group <chemistry id="chem0004" num="0004"><img file="EP0337474A2_D0004.tif" /></chemistry> and Rf is fluoroalkyl having 6 to 15 carbon atoms or fluoroalkyl having 5 to 21 carbon atoms and containing 1 to 5 oxygen atoms in the carbon ring provided that the oxygen atoms are not present adjacent to one another.

0011The present invention further provides articles on the surface of which a cured coating film derived from the composition A or B is formed.

0012We have conducted intensive research in view of the foregoing problems of the prior art and consequently found that an antifouling composition comprising a specific (meth)acrylate or a polymer containing the (meth)acrylate unit gives a coating layer of highly improved weatherability and antifouling property and exhibits excellent processability enabling bending of the article which is formed of the coating film of the composition without causing cracking or peeling of the film, and the film formed has a high hardness. The present invention has been accomplished based on this novel finding.

Detailed Description of the Invention

0013The composition A of the invention comprises a (meth)acrylate of the formula (1) as the component capable of forming antifouling coating films of highly improved properties (hereinafter referred to as "antifouling coating component").

0014With reference to the formula (1), examples of fluoroalkyl groups represented by Rf and having 6 to 12 carbon atoms or those represented by Rf and having 5 to 21 carbon atoms and containing 1 to 5 oxygen atoms in the carbon ring (provided that the oxygen atoms are not present adjacent to one another) are groups reprsented by the formula -(CF₂CF₂)_kCF(R³)CF₃ wherein k is an integer of 1 to 6, and R³ is a fluorine atom or trifluoromethyl, groups represented by the formula -[(CF₂)_ℓO]_pCF(R³)CF₃ wherein R³ is as defined above, ℓ is an integer of 1 to 3, and p is an integer of 1 to 5, groups represented by the formula <chemistry id="chem0005" num="0005"><img file="EP0337474A2_D0005.tif" /></chemistry> wherein R³ is as defined above, and q is an integer of 0 to 4, and groups represented by the formula -Ph-O-Rf′ wherein Ph is phenylene, and Rf′ is perfluoroalkylene having 5 to 15 carbon atoms.

0015More specific examples of fluorine-containing acrylates represented by the formula (1) are CH₂=CFCOOCH₂C₆F₁₃, CH₂=CFCOOCH₂CH₂C₈F₁₅, CH₂=CFCOOCH₂CH₂(CF₂)₆CF(CF₃)₂, CH₂=CFCOOCH₂CH₂(CF₂CF₂)_nC₂F₅ (mixture of compounds wherein n is an integer of 3 to 6), CH₂=CFCOOCH₂CH₂N(CH₃)SO₂C₈F₁₇, CH₂=CFCOOCH₂CH(OH)CH₂(CF₂)₆CF(CF₃)₂, <chemistry id="chem0006" num="0006"><img file="EP0337474A2_D0006.tif" /></chemistry> CH₂=(CH₃)COOCH₂CH₂C₈F₁₇, CH₂=(CH₃)COOCH₂CH₂(CF₂)₆CF(CF₃)₂ and the like.

0016Among the fluorine-containing (meth)acrylates (1), those wherein X is fluorine are more preferable.

0017When required, the composition A may contain hydrocarbon (meth)acrylates, (meth)acrylates having a functional group, etc. as antifouling coating components other than the fluorine-containing (meth)acrylates (1).

0018Examples of useful (meth)acrylates having functional group are compounds represented by the formula (3) <chemistry id="chem0007" num="0007"><img file="EP0337474A2_D0007.tif" /></chemistry> wherein X is as defined above, A is a group -(CH₂)a- (wherein a is 0 or an integer of 1 to 4), and B is a hydrogen atom, hydroxyl, epoxy, a group -NHCH₂OH, alkyl having 1 to 4 carbon atoms and having as substituent at least one of hydroxyl and halogen atoms or a group <chemistry id="chem0008" num="0008"><img file="EP0337474A2_D0008.tif" /></chemistry> (wherein R¹ and R² are the same or different and represent a hydrogen atom or a alkyl having 1 to 4 carbon atoms, and b is 0 or an integer of 1 to 3.)

0019More specific examples of such (meth)acrylates (3) are <chemistry id="chem0009" num="0009"><img file="EP0337474A2_D0009.tif" /></chemistry> CH₂=CHCOONHCH₂OH and the like.

0020Among the (meth)acrylates having a functional group and represented by the formula (3), those wherein B is a group <chemistry id="chem0010" num="0010"><img file="EP0337474A2_D0010.tif" /></chemistry> (wherein R¹, R² and b are as defined above) are particularly preferred because those (meth)acrylates impart to the coating film particularly improved antifouling properties, weatherability, curing rate, transparency, smoothness, etc.

0021Examples of useful hydrocarbon (meth)acrylates are compounds represented by the formula (4) <chemistry id="chem0011" num="0011"><img file="EP0337474A2_D0011.tif" /></chemistry> wherein X is as defined above, and Z is alkyl having 1 to 10 carbon atoms, or alicyclic or aromatic group having 6 to 10 carbon atoms.

0022More specific examples of such (meth)acrylates (4) are CH₂=CFCOOCH₃, CH₂=C(CH₃)COOCH₃, CH₂=C(CH₃)COOC₂H₅, CH₂=C(CH₃)COOC₄H₉, <chemistry id="chem0012" num="0012"><img file="EP0337474A2_D0012.tif" /></chemistry> and the like.

0023The composition A may contain ethylenically unsaturated monomers other than indicated above for reducing the cost of the composition. Examples of such monomers are ethylene, vinyl chloride, vinyl versate, stylene and the like.

0024In the case where the fluorine-containing (meth)acrylate (1), (meth)acrylate having a fucntional group (3) and hydrocarbon (meth)acrylate (4) are used in combination as antifouling coating components, the proportions of these compounds are not limited specifically but can be determined suitably. Usually it is desirable to use about 50 to about 99 wt.%, preferably about 60 to about 95 wt.%, of the fluorine-containing acrylate (1), about 1 to about 50 wt.%, preferably about 5 to about 40 wt.%, of the (meth)acrylate having a functional group (3), and up to 35 wt.%, preferably about 0.1 to about 20 wt.%, of the hydrocarbon (meth)acrylate (4). The ethylenically unsaturated monomers as defined above may be used in such an amount that the properties of the coating film are not impaired, usually up to 35 wt.% of the combined amount of all monomers.

0025The composition A contains, in addition to the antifouling coating component or components, a photopolymerization initiator or thermal polymerization initiator. Examples of useful photopolymerization initiators are those already known, such as benzoyl alkyl ethers, α-hydroxyisobutylphenone, 1-hydroxycyclohexyl phenyl ketone and the like. Examples of useful thermal polymerization initiators are also those already known, such as t-butyl peroxide, benzoyl peroxide and like peroxides, azobis(isobutyronitrile) and like azo compounds, etc. The amount of photopolymerization initiator or thermal polymerization initiator, although not limited specifically, is usually about 0.1 to about 10 parts by weight, preferably about 1 to about 5 parts by weight, per 100 parts by weight of the antifouling coating component.

0026An antifouling coating film can be formed on the desired article using the composition A in the same manner as usual coating compositions containing a photo­polymerization initiator or thermal polymerization initiator, for example, by applying the composition A to the article and thereafter irradiating the coating with ultraviolet radiation or heating the coating to polymerize the (meth)acrylate compound present in the composition. The composition can be applied by any known method, for example, by brush coating, dipping, roll coating, spin coating, spray coating, flow coating, bar coating, screen printing, etc.

0027Photopolymerization is effected using ultraviolet radiation sources such as a high pressure mercury lamp, metal halide lamp and the like.

0028Thermal polymerization are carried out at room temperature or at elevated temperatures. When the polymerization is conducted with heating, the temperature is selected depending on the kind of initiator used and usually between about 50 to about 150°C.

0029The antifouling coating film to be formed is about 0.1 to about 150 µm in thickness.

0030Further, it is possible to crosslink the fluorine-containing polymer and accelerate the curing of the coating film by incorporating a known crosslinking agent and/or crosslink accelerator into the composition A. Examples of crosslinking agents are Lewis acid compounds, amino compounds, amide compounds, imino compounds, epoxy compounds, isocyanate compounds, carboxylic acid anhydride, etc. Examples of crosslinking accelerators are hydrochloric acid, acetic acid, p-­toluenesulfonic acid, dibutyltin dilaurate, etc.

0031The composition A of the invention may further contain one or more of conventional additives such as pigment, dispersion stabilizer, viscosity regulating agent, leveling agent, anti-static agent, antigelling agent, UV absorber, antioxidant, flatting agent, filler, etc.

0032The antifouling component of the composition B is a fluorine-containing polymer containing structural units represented by the formula (2). More specifically, examples of useful fluorine-containing polymers are homopolymers or copolymers of fluorine-containing (meth)acrylates (1), copolymers of acrylates (1) and monomers copolymerizable therewith. Examples of useful monomers copolymerizable with acrylates (1) are (meth)acrylates having a functional group (3), hydrocarbon (meth)acrylates (4) and ethylenically unsaturated monomer other than monomers (1), (3) and (4) which are exemplified above. Use of the (meth)acrylate (3) as a monomer component enables the fluorine-containing copolymer obtained to exhibit improved hardness and adhesion to substrate. Further the (meth)acrylate (4), when used as a polymer component, permits the coating film formed to exhibit enhanced hardness.

0033The fluorine-containing polymer can be prepared by known radical polymerization processes, for example, by solution polymerization, bulk or mass polymerization, emulsion polymerization or suspension polymerization.

0034Examples or solvents usable for solution polymerization are m-xylenehexafluoride, trichloro­trifluoroethane and like fluorine-containing solvents, 1,1,1-trichloroethane and like chlorine-containing solvents, ethyl acetate and like ester solvents, methyl isobutyl ketone, acetone and like ketone solvents, toluene, xylene and like hydrocarbon solvents, etc. Useful polymerization initiators are those already known, such as azobisisobutyronitrile (AIBN) and like azo compounds, benzoyl peroxide and like peroxide compounds, etc. Further laurylmercaptan, thiophenol and the like may be used as chain transfer agents. The polymerization temperature, although not limited specifically, is usually about 30 to about 100°C.

0035The solution resulting from solution polymerization and containing the desired fluorine-­containing polymer may be used as it is as the composition B. Alternatively, the fluorine-containing polymer may be separated from the solution and dried before use.

0036Bulk or mass polymerization, when to be resorted to, can be conducted using the same polymerization initiator, chain transfer agent and polymerization conditions as employed for solution polymerization. Preferably, the fluorine-containing polymer obtained by bulk or mass polymerization is separated from the resulting block and dried before use.

0037Known emulsifying agents are useful in the emulsion polymerization. Examples of emulsifying agents are fluorine-containing type such as ammonium salts of perfluorocarboxylic acids and the like, polyethylene­glycols, hydrocarbon type such as alkylphenylethers and the like. Known polymerization initiators can be used which include redox initiators consisting of oxidizing agents such as ammonium persulfate, potassium persulfate and the like, reducing agents such as sodium sulfate and the like and ferrous sulfate and like salts of transition metals; azo compounds such as azoisobutyroamidine hydrochloride etc.; peroxide compounds suchd as succinic acid peroxide, etc. Emulsion polymerization is conducted under the similar conditions as in solution polymerization.

0038Suspension polyerization can be conducted in the presence of suspension stabilizer such as sodium polyacrylate or the like using the same polymerization initiator and polymerization conditions as employed for emulsion polymerization.

0039When to be copolymerized, the fluorine-­containing (meth)acrylate (1), (meth)acrylate having a functional group (3), hydrocarbon (meth)acrylate (4) and ethylenically unsaturated monomer other than monomer (1), (3) and (4) can be used in proportions which are not limited sepcifically. Usually, however, it is suitable to use about 50 to about 99 wt.%, preferably about 60 to about 95 wt.%, of the fluorine-containing acrylate (1), about 1 to about 50 wt.%, preferably about 5 to 40 wt.%, of the (meth)acrylate (3), and up to 35 wt.%, preferably about 0.1 to about 20 wt.%, of the hydrocarbon (meth)acrylate (4). The ethylenically unsaturated monomers as defined above may be used in such an amount that the properties of the coating film are not impaired, usually up to 35 wt.% of the combined amount of all monomer components.

0040Among the fluorine-containing polymers thus obtained, it is desirable to use those having a number average molecular weight of about 5,000 to about 4,000,000 (as determined by gel permeation chromatography) or those having an intrinsic viscosity [η] of about 0.15 to about 3.0 (solvent: m-xylenehexafluoride, methyl ethyl ketone, chloroform or 1,1,1-trichloroethane or the like, temperature: 35°C). If the molecular weight is too small, the antifouling coating film is liable to separate from the article treated and is likely to have low strength, whereas if it is excessively great, the composition is not always applicable to articles easily.

0041The composition B can be prepared by dissolving the antifouling coating component, i.e. the fluorine-­containing polymer, in a suitable solvent. Examples of useful solvents are m-xylenehexafluoride, trichloro­trifluoroethane and like fluorine-containing solvents, tetrachloroethylene, trichloroethylene, trichloroethane and like chlorine-containing solvents, acetone and like ketone solvents, ethyl acetate and like ester solvents, toluene and like aromatic solvents, n-hexane and like saturated aliphatic solvents, etc. The diluted composition can be applied by the same method as already described. After application, the composition is dried at room temperature or with heating at about 50 to about 150°C for 30 minutes to 7 days, whereby an antifouling coating film is formed.

0042In the case where the monomer wherein the functional group is <chemistry id="chem0013" num="0013"><img file="EP0337474A2_D0013.tif" /></chemistry> (wherein R¹, R² and b are as defined above) is uded as a film forming component, it is preferable to admix curing accelerator, water and alcohol to the composition.

0043The concentration of the antifouling component, although not limited specifically, is suitably determined usually from the range of about 0.05 to about 40 wt.%, in view of work efficiency, etc. The antifouling coating film formed from the composition B may have the same thickness as is the case with the composition A. When the composition B is to be used, a crosslinking agent and/or crosslinking accelerator and additives mentioned above may be added to the composition B to further crosslink the fluorine-containing polymer and to thereby assure the coating of promoted curing.

0044Before the application of the composition of the invention, a primer coating may be formed on the surface of substrate or article to be protected in order to improve the adhesion of antifouling coating film to the surface. Any primer composition can be used which include those comprising silane coupling agent, acryl-silicone polymer, acrylate polymer, epoxy polymer, urethane polymer, etc.

0045The articles of the invention are partially or wholy coated with the composition A or B. The articles to be coated are not specifically limited and include those formed from a wide range of materials. Examples of the materials for articles are metals such as iron, aluminum, copper and alloys thereof; glass and enameled ware; resins such as ABS resin, AXS resin, polycarbonate resin, polyacrylate resin, polymethacrylate resin, amino resin, phenol resin, alkyd resin, polyvinyl chloride resin, polyester resin, polyurethane resin, polyamide resin, polyacetal resin, polyethylene resin, polypropylene resin, epoxy resin, furan resin, diallyl phthalate resin, polyvinyl acetate resin, polystylene resin, cellulosic plastics, etc.; natural and synthetic rubbers; wood, etc. Articles formed from these materials may be pre-­treated by plating, chemical conversion, oxidation and the like. Further, Articles may be formed of coating of resin as mentioned above.

0046Articles to be coated with the antifouling composition of the invention are not limited and include building, bridge, plant, sound-proof wall, tunnel, antennas and like outdoor constructions; refrigerator, television set, microwave oven, washer, dryer, electric ion, rice cooker, electric fan, air circulating fan, illuminating apparatus, air conditioner, stereo audio player and like household electric appliances; sink, cooking table, wagon and like kitchen ware; bathtub, bath burner, washbowl, toilet bowl and like sanitary ware; furniture, desk, interior wall board and the like; personal computer, word processor, copying machine, shredder, communication device, cabinet and like business machines; car, railroad car, ship, aircraft and like vehicles; inner surface of injection nozzle of ink-jet type printer, etc.

0047The antifouling coating compositions of the invention can produce coating films excellent in weatherability and antifouling property and having good processability. Thus, the article formed of the coating film of the composition of the invention can be bent without entailing cracks in the film or peeling of the film. Further, the coating film formed has a remarkable hardness.

0048For a better understanding of the invention, examples and comparative examples are given below.

Example 1

0050A 75 g quantity of CH₂=CFCOOCH₂CH₂C₈F₁₇ (hereinafter referred to as "αF17F"), 25 g of CH₂=CFCOO(CH₂)₃Si(OCH₃)₃ and 3 g of Dalocure 1116 (photopolymerization initiator, product of Merck) were throughly mixed to obtain a composition of the invention.

0051The composition was applied with a doctor blade to a degreased aluminum sheet (BT712) to a thickness of 10 µm. The aluminum sheet was then irradiated with ultraviolet radiation to cure the coated composition. The antifouling coating film thus prepared was 9 µm in thickness.

0052The antifouling coating film was found to be resistant to m-xylene hexafluoride (mXHF), showing the film was fully crosslinked.

Example 2

0053A 4-necked flask was charged with a mixture of 66 g of αF17F, 30 g of methylmethacrylate (MMA), 4 g of hydroxypropylacrylate (HPA), 0.5 g of azobisisobutyro­nitrile (AIBN) and 233 g of mXHF. After replacing the air in the flask with nitrogen, the mixture was reacted at 50°C for 24 hours to obtain a 30 wt.% solution of fluorine-containing copolymer. To 30 g quantity of the solution were added 0.3 g of crosslinking agent (trademark "Melan 28", product of Hitachi Kasei Kabushiki Kaisha) and 0.1 g of p-toluenesulfonic acid (crosslinking accelerator). The intrinsic viscosity (η) of the copolymer after crosslinking determined at 35°C using mXHF as solvent was 0.42.

0054The copolymer solution was diluted with 1,1,1-­trichloroethane to a concentration of 20 wt.% to obtain a composition of the invention.

0055The composition thus produced was applied with a brush to a degreased aluminum sheet (BT712) and the aluminum sheet was heated at 140°C for 60 minutes to cure the coated composition and to form a antifouling coating film 15 µm in thickness.

Examples 3 to 5

0056The compounds (1) to (7) shown below were polymerized in the same manner as in Example 2 to obtain fluorine-containing polymers each having the composition and intrinsic viscosity [η] listed in Table 1.

0057(1) CH₂=CFCOOCH₂CH₂(CF₂)₆CF(CF₃)₃ <chemistry id="chem0014" num="0014"><img file="EP0337474A2_D0014.tif" /></chemistry> (4) CH₂=CHCOOCH₂CH₂OH (5) CH₂=CFCOOCH₂CH₂C₈F₁₇ (6) CH₂=C(CH₃)COO(CH₂)₃Si(OCH₃)₃ (7) CH₂=CFCOO(CH₂)₃Si(OCH₃)₃

0058To each of the fluorine-containing polymer solution obtained were added curing agent and/or curing accelerator as required and the solution was applied to a degreased aluminum sheet (BT712). The coating layer on the sheet was cured under the conditions listed in Table 1 to form an antifouling coating film. <tables id="tabl0001" num="0001"><table frame="all"><title>Table 1</title><tgroup cols="7" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="22.50mm" /><colspec colnum="2" colname="col2" colwidth="22.50mm" /><colspec colnum="3" colname="col3" colwidth="22.50mm" /><colspec colnum="4" colname="col4" colwidth="22.50mm" /><colspec colnum="5" colname="col5" colwidth="22.50mm" /><colspec colnum="6" colname="col6" colwidth="22.50mm" /><colspec colnum="7" colname="col7" colwidth="22.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">Ex.</entry><entry namest="col2" nameend="col2" align="center">Composition of copolymer (wt. ratio)</entry><entry namest="col3" nameend="col3" align="center">Intrinsic viscosity [η]</entry><entry namest="col4" nameend="col4" align="center">Crosslinking agent</entry><entry namest="col5" nameend="col5" align="center">Crosslinking accelerator</entry><entry namest="col6" nameend="col6" align="center">Condition</entry><entry namest="col7" nameend="col7" align="center">Film thickness (µm)</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="right">3</entry><entry namest="col2" nameend="col2" align="right">(1)/(2)/(6) 75/20/5</entry><entry namest="col3" nameend="col3" align="char" char=".">0.25</entry><entry namest="col4" nameend="col4" align="left">-</entry><entry namest="col5" nameend="col5" align="left">Acetic acid¹⁾, water : IPA²⁾</entry><entry namest="col6" nameend="col6" align="right">80°C x 24 hr.</entry><entry namest="col7" nameend="col7" align="right">28</entry></row><row><entry namest="col1" nameend="col1" align="right">4</entry><entry namest="col2" nameend="col2" align="right">(5)/(7) 80/20</entry><entry namest="col3" nameend="col3" align="char" char=".">0.48</entry><entry namest="col4" nameend="col4" align="left">-</entry><entry namest="col5" nameend="col5" align="left">Dibutyltin dilaurate³⁾, water : IPA²⁾</entry><entry namest="col6" nameend="col6" align="right">80°C x 24 hr.</entry><entry namest="col7" nameend="col7" align="right">21</entry></row><row rowsep="0"><entry namest="col1" nameend="col1" align="right">5</entry><entry namest="col2" nameend="col2" align="right">(1)/(3)/(4) 70/20/10</entry><entry namest="col3" nameend="col3" align="char" char=".">0.23</entry><entry namest="col4" nameend="col4" align="left">Colonate EH⁴⁾</entry><entry namest="col5" nameend="col5" align="left">Dibutyltin dilaurate³⁾</entry><entry namest="col6" nameend="col6" align="right">room temp. x 7 days</entry><entry namest="col7" nameend="col7" align="right">30</entry></row></tbody></tgroup><tgroup cols="7" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="22.50mm" /><colspec colnum="2" colname="col2" colwidth="22.50mm" /><colspec colnum="3" colname="col3" colwidth="22.50mm" /><colspec colnum="4" colname="col4" colwidth="22.50mm" /><colspec colnum="5" colname="col5" colwidth="22.50mm" /><colspec colnum="6" colname="col6" colwidth="22.50mm" /><colspec colnum="7" colname="col7" colwidth="22.50mm" /><tbody valign="top"><row><entry namest="col1" nameend="col7" align="justify">1) 0.001 g per 1 g of polymer</entry></row><row><entry namest="col1" nameend="col7" align="justify">2) Water : IPA (isopropanol) = 1:1 ... 0.001 g per 1 g of polymer</entry></row><row><entry namest="col1" nameend="col7" align="justify">3) 0.0001 g per 1 g of polymer</entry></row><row><entry namest="col1" nameend="col7" align="justify">4) Product of Nippon Polyurethane Kabushiki Kaisha, 0.15 g</entry></row></tbody></tgroup></table></tables>

Example 6

0059Using 75 g of CH₂=C(CH₃)COOCH₂CH₂C₈H₁₇ and 25 g of CH₂=C(CH₃)COO(CH₂)₃Si(OCH₃)₃, an antifouling coating film 9 µm in thickness was formed on an aluminum sheet in the same manner as in Example 1.

Comparative Example 1

0060Using 70 g of CH₂=CFCOOCH₂CH₂C₂F₅ and 30 g of MMA and following the polymerization procedure of Example 2, a fluorine-containing copolymer having an intrinsic viscosity of 0.55 was obtained. An antifouling coating film (30 µm) was produced in the same manner as in Example 2.

Comparative Example 2

0061A mixture of 50 g of an acrylic paint composition (trademark "Hitaloyd", product of Hitachi Kasei Kabushiki Kaisha) and 5.3 g of a crosslinking agent (trademark "Colonate EH", product of Nippon Polyurethane Kabushiki Kaisha) was diluted with a mixture of ethyl acetate/toluene (1/1) to a paint concentration of 30 wt.%.

0062The diluted paint composition was applied to a degreased aluminum sheet and cured at room temperature for 7 days to form an antifouling coating film 30 µm in thickness.

Comparative Example 3

0063A mixture of 100 g of fluorine-containing weather resistant paint composition (trademark "Lumiflon", a product of Asahi Glass Co., Ltd.), 9.3 g of crosslinking agent (trademark "Colonate EH"), 3.5 mg of dibutyltin dilaurate and 100 g of xylene/methylisobutylketone (1/3) was applied to an aluminum sheet and cured at room temperature for 7 days to produce an antifouling coating film 30 µm in thickness.

Example 7

0064The antifouling coating films obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were tested for the following properties.

0065Results are given in Table 2.

I. Weatherability (1):

0066The coating film was subjected to weathering test for 2000 hours using "super long life sunshine carbon arc weather meter" (product of Suga Shikenki Kabushiki Kaisha) under the condition of wetting stage/drying stage = 18 min./120 min. After the completion of the test, gloss retaining rate (%) of mirror kept at the angle of 60° was measured.

II. Weatherability (2):

0067Contact angles (°) with water of the coating film before and after the weatherability test (1) were measured, using CA-DS type contact angle tester (product of Kyowa Kagaku Kabushiki Kaisha).

III. Antifouling Property (1):

0068The aluminum sheet formed of antifouling coating film was bonded to the outer wall of a building of a plant at Settsu-shi, Osaka of Daikin Industries Ltd. After the lapse of one month, the aluminum sheet was washed with water and checked for gloss retaining rate according to the following criteria. <ul id="ul0001" list-style="none"><li>A ... Gloss retaining rate was over 90%</li><li>B ... Gloss retaining rate was between 80% and 90%.</li><li>C ... Gloss retaining rate was between 60% and 70%.</li><li>D ... Glass retaining rate was less than 60%.</li></ul>

IV. Antifouling Property (2):

0069On the antifouling coating film formed on aluminum sheet were drawn ten red lines with an oil marker (product of Sakura Color Products, Co., Ltd.). The lines were erased with wiping cloth (trademark "Kim Wipe", product of Jujo Kimberley Co., Ltd.) attached to rubbing tester (product of Taihei Rika Kogyo Kabushiki Kaisha). The number of wiping strokes required for removing ten lines was determined.

0070Similar test specimen was set up on the roof of a factory at an angle of 45° and exposed to the atmosphere for 6 months. Wiping test for removing red lines was carried out in the same manner as above. <tables id="tabl0002" num="0002"><table frame="all"><title>Table 2</title><tgroup cols="6" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="26.25mm" /><colspec colnum="2" colname="col2" colwidth="26.25mm" /><colspec colnum="3" colname="col3" colwidth="26.25mm" /><colspec colnum="4" colname="col4" colwidth="26.25mm" /><colspec colnum="5" colname="col5" colwidth="26.25mm" /><colspec colnum="6" colname="col6" colwidth="26.25mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col4" align="center"><u style="single">Weatherability</u></entry><entry namest="col5" nameend="col5" align="center">Antifouling test¹⁾ Gloss retaining rate (%)</entry><entry namest="col6" nameend="col6" align="center">Antifouling test²⁾ Initial/After 6 months</entry></row><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center">Gloss retaining (%)</entry><entry namest="col3" nameend="col4" align="center"><u style="single">Contact angle (°)</u></entry><entry namest="col5" nameend="col5" /><entry namest="col6" nameend="col6" /></row><row rowsep="1"><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" /><entry namest="col3" nameend="col3" align="center">Before test</entry><entry namest="col4" nameend="col4" align="center">After test</entry><entry namest="col5" nameend="col5" /><entry namest="col6" nameend="col6" /></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Ex. 1</entry><entry namest="col2" nameend="col2" align="char" char=".">98.5</entry><entry namest="col3" nameend="col3" align="right">115</entry><entry namest="col4" nameend="col4" align="right">106</entry><entry namest="col5" nameend="col5" align="left">A</entry><entry namest="col6" nameend="col6" align="right">6/6</entry></row><row><entry namest="col1" nameend="col1" align="left">2</entry><entry namest="col2" nameend="col2" align="char" char=".">98.0</entry><entry namest="col3" nameend="col3" align="right">116</entry><entry namest="col4" nameend="col4" align="right">108</entry><entry namest="col5" nameend="col5" align="left">B</entry><entry namest="col6" nameend="col6" align="right">30/30</entry></row><row><entry namest="col1" nameend="col1" align="left">3</entry><entry namest="col2" nameend="col2" align="char" char=".">97.0</entry><entry namest="col3" nameend="col3" align="right">118</entry><entry namest="col4" nameend="col4" align="right">110</entry><entry namest="col5" nameend="col5" align="left">B</entry><entry namest="col6" nameend="col6" align="right">20/25</entry></row><row><entry namest="col1" nameend="col1" align="left">4</entry><entry namest="col2" nameend="col2" align="char" char=".">98.2</entry><entry namest="col3" nameend="col3" align="right">115</entry><entry namest="col4" nameend="col4" align="right">105</entry><entry namest="col5" nameend="col5" align="left">A</entry><entry namest="col6" nameend="col6" align="right">6/6</entry></row><row><entry namest="col1" nameend="col1" align="left">5</entry><entry namest="col2" nameend="col2" align="char" char=".">97.5</entry><entry namest="col3" nameend="col3" align="right">116</entry><entry namest="col4" nameend="col4" align="right">108</entry><entry namest="col5" nameend="col5" align="left">A</entry><entry namest="col6" nameend="col6" align="right">18/20</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">6</entry><entry namest="col2" nameend="col2" align="char" char=".">58.2</entry><entry namest="col3" nameend="col3" align="right">115</entry><entry namest="col4" nameend="col4" align="right">100</entry><entry namest="col5" nameend="col5" align="left">C</entry><entry namest="col6" nameend="col6" align="right">8/80</entry></row><row><entry namest="col1" nameend="col1" align="left">Comp. Ex. 1</entry><entry namest="col2" nameend="col2" align="char" char=".">81.6</entry><entry namest="col3" nameend="col3" align="right">105</entry><entry namest="col4" nameend="col4" align="right">100</entry><entry namest="col5" nameend="col5" align="left">D</entry><entry namest="col6" nameend="col6" align="right">100/200</entry></row><row><entry namest="col1" nameend="col1" align="left">2</entry><entry namest="col2" nameend="col2" align="char" char=".">60.7</entry><entry namest="col3" nameend="col3" align="right">83</entry><entry namest="col4" nameend="col4" align="right">70</entry><entry namest="col5" nameend="col5" align="left">D</entry><entry namest="col6" nameend="col6" align="right">100/200</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">3</entry><entry namest="col2" nameend="col2" align="char" char=".">97.9</entry><entry namest="col3" nameend="col3" align="right">84</entry><entry namest="col4" nameend="col4" align="right">82</entry><entry namest="col5" nameend="col5" align="left">D</entry><entry namest="col6" nameend="col6" align="right">400&lt;/400&lt;</entry></row></tbody></tgroup></table></tables>

Example 8

0071The aluminum sheets on which the antifouling coating films were formed in Examples 1 to 5 and Comparative Example 1 to 3 were subjected to the following processability tests.

0072Results are given Table 3 below.

I. Bending test:

0073Bending test according to JIS K 5400 was carried out using a rod (2 mm in diameter) and a support plate (4 mm in thickness) to evaluate the quality of the antifouling coating film.

0074The criteria for evaluation are as follows. <ul id="ul0002" list-style="none"><li>A ... No defects found.</li><li>B ... Cracks found or small area peeled.</li><li>C ... Film peeled.</li></ul>

II. Impact test:

0075Impact test according to JIS K 5400 (Du pont Impact test) was carried out under the conditions; weight=500 g, falling distance=50 cm, radius of blow mold=6.35 mm, and the quality of the antifouling coating film was evaluated with the following criteria. <ul id="ul0003" list-style="none"><li>A ... No defects such as crack, peeling detected.</li><li>B ... Cracks and/or peeling of small area detected.</li><li>C ... Film peeled.</li></ul><tables id="tabl0003" num="0003"><table frame="all"><title>Table 3</title><tgroup cols="3" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center"><u style="single">Bending Test</u></entry><entry namest="col3" nameend="col3" align="center"><u style="single">Impact Test</u></entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Ex. 1</entry><entry namest="col2" nameend="col2" align="left">A</entry><entry namest="col3" nameend="col3" align="left">A</entry></row><row><entry namest="col1" nameend="col1" align="left">2</entry><entry namest="col2" nameend="col2" align="left">A</entry><entry namest="col3" nameend="col3" align="left">A</entry></row><row><entry namest="col1" nameend="col1" align="left">3</entry><entry namest="col2" nameend="col2" align="left">A</entry><entry namest="col3" nameend="col3" align="left">A</entry></row><row><entry namest="col1" nameend="col1" align="left">4</entry><entry namest="col2" nameend="col2" align="left">A</entry><entry namest="col3" nameend="col3" align="left">A</entry></row><row><entry namest="col1" nameend="col1" align="left">5</entry><entry namest="col2" nameend="col2" align="left">B</entry><entry namest="col3" nameend="col3" align="left">B</entry></row><row><entry namest="col1" nameend="col1" align="left">Comp. Ex. 1</entry><entry namest="col2" nameend="col2" align="left">C</entry><entry namest="col3" nameend="col3" align="left">C</entry></row><row><entry namest="col1" nameend="col1" align="left">2</entry><entry namest="col2" nameend="col2" align="left">C</entry><entry namest="col3" nameend="col3" align="left">B</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">3</entry><entry namest="col2" nameend="col2" align="left">C</entry><entry namest="col3" nameend="col3" align="left">B</entry></row></tbody></tgroup></table></tables>

0076Table 2 and 3 reveal that the compositions of the invention can produce coating films excellent in antifouling property, weatherability and processability.

Example 9

0077A 75 g quantity of CH₂=CFCOOCH₂CH₂C₈F₁₇ and 75 g of CH₂=CFCOO(CH₂)₃Si(OCH₃)₃ were copolymerized in the similar manner as in Example 2 and the copolymer obtained was diluted with mXHF to produce a solution with a solid concentration of 5 wt.%. Dibutyltin dilaurate (curing accelerator) was added to the solution in an amount of 0.1 part per 100 parts of solid to prepare an antifouling coating composition.

0078The coating composition was applied with a brush to the surface of body (ABS resin) of an electric cleaner. The coated composition was dried at room temperature for 30 minutes and then heated at 80°C for 12 hours to obtain a cured coating film 5 µm in thickness.

0079The electric cleaner body formed of the coating film was subjected to the tests listed in Table 4. Table 4 shows the results of an electric cleaner to which the coating composition was not applied. <tables id="tabl0004" num="0004"><table frame="all"><title>Table 4</title><tgroup cols="5" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="31.50mm" /><colspec colnum="2" colname="col2" colwidth="31.50mm" /><colspec colnum="3" colname="col3" colwidth="31.50mm" /><colspec colnum="4" colname="col4" colwidth="31.50mm" /><colspec colnum="5" colname="col5" colwidth="31.50mm" /><thead valign="top"><row rowsep="1"><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center">Marking Pen ¹⁾</entry><entry namest="col3" nameend="col3" align="center">Hand dirts</entry><entry namest="col4" nameend="col4" align="center">Cross Cut ²⁾</entry><entry namest="col5" nameend="col5" align="center">Pencil Hardness</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Coated cleaner</entry><entry namest="col2" nameend="col2" align="left">Not stained</entry><entry namest="col3" nameend="col3" align="left">Not stained</entry><entry namest="col4" nameend="col4" align="right">100/100</entry><entry namest="col5" nameend="col5" align="left">H</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Non-coated cleaner</entry><entry namest="col2" nameend="col2" align="left">Stained</entry><entry namest="col3" nameend="col3" align="left">Stained</entry><entry namest="col4" nameend="col4" align="right">-</entry><entry namest="col5" nameend="col5" align="left">HB</entry></row></tbody></tgroup><tgroup cols="5" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="31.50mm" /><colspec colnum="2" colname="col2" colwidth="31.50mm" /><colspec colnum="3" colname="col3" colwidth="31.50mm" /><colspec colnum="4" colname="col4" colwidth="31.50mm" /><colspec colnum="5" colname="col5" colwidth="31.50mm" /><tbody valign="top"><row><entry namest="col1" nameend="col5" align="justify">1) : Red oil marker (product of Sakura Color Products Co., Ltd.)</entry></row><row><entry namest="col1" nameend="col5" align="justify">2) : JIS K 5400</entry></row></tbody></tgroup></table></tables>

Example 10

0080Fololowing the procedure of Example 9, an antifouling coating film was formed on a sound proof board made of polycarbonate.

0081The board was fixed for one year to the wall along a road in Settsu-shi, Osaka and then subjected to the same tests as in Example 9. The results are given in Table 5. <tables id="tabl0005" num="0005"><table frame="all"><title>Table 5</title><tgroup cols="4" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="39.37mm" /><colspec colnum="2" colname="col2" colwidth="39.37mm" /><colspec colnum="3" colname="col3" colwidth="39.37mm" /><colspec colnum="4" colname="col4" colwidth="39.37mm" /><thead valign="top"><row rowsep="1"><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center">Marking Pen</entry><entry namest="col3" nameend="col3" align="center">Cross Cut</entry><entry namest="col4" nameend="col4" align="center">Pencil Hardness</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Coated board</entry><entry namest="col2" nameend="col2" align="left">Not stained</entry><entry namest="col3" nameend="col3" align="right">100/100</entry><entry namest="col4" nameend="col4" align="left">H</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Non-coated board</entry><entry namest="col2" nameend="col2" align="left">Stained</entry><entry namest="col3" nameend="col3" align="right">-</entry><entry namest="col4" nameend="col4" align="left">HB</entry></row></tbody></tgroup></table></tables>

Example 11

0082Following the procedure of Example 9, the antifouling coating composition was applied to the aluminum fin element of air conditioner and cured.

0083The air conditioner was continuously operated for 10 days and frost formation on the fin element was checked.

0084The results are shown in Table 6 below. <tables id="tabl0006" num="0006"><table frame="all"><title>Table 6</title><tgroup cols="4" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="39.37mm" /><colspec colnum="2" colname="col2" colwidth="39.37mm" /><colspec colnum="3" colname="col3" colwidth="39.37mm" /><colspec colnum="4" colname="col4" colwidth="39.37mm" /><thead valign="top"><row rowsep="1"><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center">Frost</entry><entry namest="col3" nameend="col3" align="center">Cross Cut</entry><entry namest="col4" nameend="col4" align="center">Marking Pen</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Coated fin</entry><entry namest="col2" nameend="col2" align="left">Almost no formation</entry><entry namest="col3" nameend="col3" align="right">100/100</entry><entry namest="col4" nameend="col4" align="left">Not stained</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Non-coated fin</entry><entry namest="col2" nameend="col2" align="left">Distinct formation</entry><entry namest="col3" nameend="col3" align="right">-</entry><entry namest="col4" nameend="col4" align="left">Stained</entry></row></tbody></tgroup></table></tables>