JP3053081B2 - Copolymer for antifouling coating material - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymer useful as an antifouling coating material for preventing aquatic organisms from adhering to underwater structures, fishing nets, ship bottoms, and the like. . 2. Description of the Related Art Aquatic organisms adhere to and propagate on underwater structures, fishing nets, boat bottoms, and other articles that are used for a long time in water, as well as impair the appearance thereof, and adversely affect their functions. Sometimes. [0003] In the case of a ship bottom, the attachment of aquatic organisms leads to an increase in the surface roughness of the whole ship, and furthermore, the ship speed decreases and the fuel efficiency increases. In addition, the repair time at the dock is prolonged, and the operating efficiency is significantly reduced. In addition, proliferation of bacteria causes enormous damage such as spoilage of underwater structures, deterioration of physical properties, and remarkable reduction in life. Heretofore, as antifouling agents used to avoid such damage, organic chlorine compounds, cuprous oxide, organic tin compounds and the like have been known. [0005] Physiologically active substances containing heavy metals such as organic tin compounds and cuprous oxide have particularly excellent antifouling effects and are considered to be essential components for paints for fishing nets and ship bottoms. For example, U.S. Pat. No. 3,167,473 describes an antifouling agent using an organotin compound, which is called "polymer type". This antifouling agent has an organotin-containing group in the side chain of the copolymer, and is hydrolyzed in slightly alkaline seawater to release an organotin compound, exhibiting an antifouling effect and being hydrolyzed at the same time. Since the copolymer itself becomes water-soluble and dissolves in seawater, an active surface can always be maintained without leaving a resin residue layer. Japanese Patent Application Laid-Open No. 60-231771 discloses an organic-containing copolymer used in combination with an organic tin compound or a cuprous oxide for the purpose of promoting the dissolution of a physiologically active substance. A method using a hydrolyzable silyl (meth) acrylate such as tributylsilyl acrylate or triphenylsilyl (meth) acrylate as a part of the monomer is described. [0007] However, these antifouling agents have a problem in that they have poor storage stability and, particularly when used in combination with cuprous oxide, will gel within a few days. Moreover, these antifouling agents contain heavy metals and hydrolyzable organotin-containing groups, and are therefore highly toxic. In particular, organotin compounds are highly irritating and cause inflammation when touching the skin. In addition, there were serious problems such as marine pollution due to runoff into seawater, generation of malformed fish, and accumulation in the human body due to ecological enrichment. [0008] To cope with the above-mentioned problems, for example, Japanese Patent Application Laid-Open No. Sho.
In the publication, without using an organotin-containing copolymer,
A bottom paint exhibiting an antifouling effect is described. This hull bottom paint is composed of a poison and a self-polishing polymer, and the polymer monomer is tris (4-methyl-2).
Hydrolyzable silyl (meth) acrylates, such as -pentoxy) silyl acrylate, are described. However, in this hull bottom paint, the self-polishing polymer only acts as a poisonous supply system (del-ivery system) and has no antifouling property itself, so that a poisonous component is essential. In this ship bottom paint, the basic principle of antifouling of killing aquatic organisms attached by poison is the same as the conventional antifouling agent,
Serious environmental problems could not be avoided. In addition, when cuprous oxide is used as a poison, there is a problem that the preservation stability is poor and gelation occurs within a few days. [0010] Furthermore, the tris (4
-Methyl-2-pentoxy) silyl acrylate has a hydrolyzable property in both of the two bonds between the silicon atom and the alkoxy bond and between the silicon atom and the ester bond. There was also a problem that it became difficult to control the solubility of the compound. It is an object of the present invention to provide a copolymer for an antifouling coating material which does not contain an organotin-containing polymer and does not adversely affect marine ecosystems. The present inventors have focused on the self-polishing property of a copolymer defined by the following specific formula. The present invention has been accomplished by finding a copolymer having excellent antifouling property and good storage stability even without the above. That is, the copolymer for an antifouling coating material of the present invention has a self-polishing effect in which the silyl group of the side chain of the copolymer represented by the following general formula is released by hydrolysis, and then the copolymer itself becomes water-soluble. And exhibits an antifouling property. (Wherein, R ¹ is a hydrogen atom or a methyl group, R ² , R ³ ,
R ⁴ represents a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, and a phenyl group), at least one unsaturated triorganosilyl monomer represented by the following formula: And a tin-free copolymer obtained by polymerizing at least one organic monomer selected from (meth) acrylic and vinyl compounds and having a degree of polymerization not exceeding 190. . The copolymer used in the present invention is a characteristic component in the present invention, and exhibits an appropriate hydrolyzability by selecting an organic group bonded to a silicon atom of a triorganosilyl group, and exhibits a water-soluble property in water. Since it gradually hydrolyzes to increase its hydrophilicity, it shows a controlled solubility property in water. Such a copolymer can be obtained by polymerizing one or more triorganosilyl monomers and one or more organic monomers to a degree of polymerization not exceeding 190. Can be The composition ratio of the unsaturated triorganosilyl monomer and the organic monomer is not particularly limited, but preferably the amount of the unsaturated triorganosilyl monomer is 10 to 10.
It is in the range of 95% by weight, more preferably 20-70% by weight. By setting the amount of the unsaturated triorganosilyl monomer in the above range, particularly good hydrolysis rate and coating film properties can be obtained, and good antifouling power can be maintained for a long period of time. In the unsaturated triorganosilyl monomer which is one of the starting materials of the copolymer, R ¹ is a hydrogen atom or a methyl group, and R ² , R ³ and R ⁴ each have 1 to 18 carbon atoms. An independent monovalent hydrocarbon group selected from a linear or branched alkyl group, a cycloalkyl group and a phenyl group. As this alkyl group,
Examples of a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a myristyl group, a stearyl group and the like, and examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group. . In order to have moderate hydrolyzability and thereby control the slow solubility of the coating material in water, R ² ,
It is preferable that at least one of R ³ and R ⁴ has 4 or more carbon atoms. Such unsaturated triorganosilyl monomers include dimethylbutylsilyl acrylate, dimethylhexylsilyl acrylate, dimethyloctylsilyl acrylate, dimethyldecylsilyl acrylate, dimethyldodecylsilyl acrylate, dimethylcyclohexylsilyl acrylate and dimethylphenylsilyl. Acrylate, dimethyldibutylsilyl acrylate, ethyldibutylsilyl acrylate, dibutylhexylsilyl acrylate, dibutylphenylsilyl acrylate, tributylsilyl acrylate, triphenylsilyl acrylate, and the like; and methacrylate corresponding thereto are exemplified. Among them, the hydrolysis rate is slow, the synthesis is easy, and the film-forming property is good, because R ² , such as dimethylhexylsilyl (meth) acrylate and dimethyldecylsilyl (meth) acrylate, R ³ and R ⁴ in which two are methyl groups and the remainder is a long-chain alkyl group having 6 or more carbon atoms are excellent, but have a controlled hydrolysis rate in water and obtain a moderate slow solubility. For this purpose, tributylsilyl (meth) acrylate is preferred. The organic monomer as the other starting material of the copolymer is selected from (meth) acrylic and vinyl compounds. Examples of the (meth) acrylic compound include methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate (the above alkyl group may be linear or branched), 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate Dimethylaminoethyl acrylate, acrylamide, acrylonitrile, and the like; and methacrylic compounds corresponding thereto. Examples of the vinyl compound include vinyl acetate, vinyl chloride, vinyl methyl ether, vinyl propyl ether, vinyl isobutyl ether, and vinyl pyrrolidrin. Etc. are exemplified. The polymerization is carried out, for example, by mixing an unsaturated triorganosilyl monomer and an organic monomer in the presence of an organic solvent and using a polymerization initiator. The organic solvent is for controlling the polymerization and preventing the formation of a gel during the reaction, and includes a hydrocarbon solvent such as benzene, toluene and xylene; an ester solvent such as ethyl acetate and butyl acetate; Examples thereof include alcohol solvents such as methanol and ethanol; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; and aprotic polar solvents such as dimethylformamide and dimethyl sulfoxide. The amount of the organic solvent is preferably from 20 to 1,000 parts by weight, more preferably from 50 to 500 parts by weight, based on 100 parts by weight of the total of the monomers. By setting the amount of the organic solvent within the above range, particularly good controllability of the reaction and simplification of the production process can be achieved. Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, t-butyl perbenzoate, methyl ethyl ketone peroxide and cumene hydroperoxide, and azo compounds such as azobisisobutyronitrile. The amount of the polymerization initiator is generally 0.01 to 10 parts by weight based on 100 parts by weight of the total amount of the monomers. The polymerization conditions are not particularly limited, but it is preferably carried out in a nitrogen stream. In general, the polymerization is carried out at a temperature of 60 to 120 ° C when the polymerization initiator is an organic peroxide, and at 45 to 100 ° C when the polymerization initiator is an azo compound. Will be The coating material using the above specific copolymer of the present invention can be obtained by mixing the above copolymer alone or, if necessary, a pigment, an organic solvent, a thixotropic agent and the like. Since the target of the antifouling treatment is as diverse as underwater structures, fishing nets, ship bottoms, etc., the blending ratio is not particularly limited, but by setting the blending amount of the copolymer within the above range, particularly good coating film forming property and workability are achieved. Property is obtained. Examples of the pigment include seawater inactive pigments such as red iron oxide, titanium white, talc, silica, calcium carbonate and barium sulfate, and seawater reactive pigments such as zinc oxide and calcium oxide. Combinations of more than one species are acceptable. As the organic solvent, those similar to those used in the polymerization step for obtaining the copolymer described above are used. Examples of the thixotropic material include bentonite, polyethylene oxide and amide compounds. The present invention will be described below with reference to examples and comparative examples. The parts in the following examples indicate parts by weight. <Synthesis of Copolymer> A reactor equipped with a cooler, a stirrer, and a thermometer was charged with 300 parts of xylene, and 120 parts of dimethylhexylsilyl methacrylate, 180 parts of methyl methacrylate were added thereto.
And 2 parts of azobisisobutyronitrile,
And the mixture was heated and stirred for 8 hours to carry out polymerization. After cooling to room temperature, 66 parts of ethyl acetate was added to obtain a pale yellow transparent copolymer solution V-1. V-1 had a viscosity at 25 ° C. of 480 cP and a solid content of 44.8%. In the same manner except that V-1 and the organic solvent after polymerization were not added, the light yellow transparent copolymer solutions V-2 to V-2 were prepared from the organic solvents, monomers and reaction initiators shown in Table 1. V
-7 was obtained. The viscosity and solid content of the obtained copolymer solution are as shown in Table 1. In addition, the number which shows the compounding quantity in a table | surface represents a part (the same hereafter). Further, a copolymer having a low polymerization degree (H-1) and a copolymer having a high polymerization degree (H-2) were synthesized as follows. First, 300 parts of xylene was charged into a reaction vessel equipped with a cooler, a stirrer, and a thermometer, and 144 parts of tributylsilyl methacrylate and 15 parts of methyl methacrylate were added thereto.
6 parts, 6 parts of n-octylmercaptan and 6 parts of azobisisobutyronitrile were added, and the mixture was heated and stirred at 95 ° C. for 8 hours, and then cooled to room temperature to obtain a colorless and transparent polymer having a low polymerization degree. A combined solution H-1 was obtained. H-1 of 2
The viscosity at 5 ° C. is 48 cP, and the solid concentration is 47.4%.
Met. Further, 300 parts of xylene was charged into a reaction vessel equipped with a condenser, a stirrer and a thermometer, and 144 parts of tributylsilyl methacrylate, 156 parts of methyl methacrylate and 0.1 part of azobisisobutyronitrile were added.
6 parts were added, polymerization was carried out by heating and stirring at 80 ° C. for 8 hours, and then cooled to room temperature to obtain a colorless and transparent high-polymerization degree copolymer solution H-2. H-2 had a viscosity at 25 ° C. of 1760 cP and a solid content of 49.9%. From the amount of each monomer charged and the yield of the copolymer, it was confirmed that substantially all of the monomers had been polymerized. Table 1 shows the GPC method of each of the above copolymers (column: TSK-GEL G4000HXL, manufactured by Toyoso Co., Ltd.).
-G2000HXL, solvent: tetrahydrofuran, converted to polystyrene) (number average molecular weight (Mn)), and the degree of polymerization calculated from Mn and the charged composition of the monomer at the time of copolymer synthesis obtained by the GPC method. [Table 1] <Examples 1 to 10, Reference Examples 1 to 2, Comparative Examples 1 to 4 and Comparative Examples 6 to 7> Using the copolymer solution obtained as described above, a stain-resistant coating material was prepared. 2 was prepared. Also,
As Comparative Examples 1 and 2, antifouling paints using varnishes A and B shown in Table 3 consisting of a copolymer of cuprous oxide, tributyltin methacrylate and methyl methacrylate were prepared according to the formulations shown in Table 4. Comparative Examples 3 and 4
The antifouling paint using the conventional cuprous oxide was prepared according to the formulation shown in Table 4. Further, as Reference Examples 1 and 2, antifouling coating materials were prepared using the copolymer solution H-1 according to the formulation shown in Table 2. Comparative Examples 6 to
As No. 7, an antifouling coating material was prepared using the copolymer solution H-2 according to the formulation shown in Table 2. [Table 2] [Table 3] [Table 4] Using the antifouling coating materials and the antifouling paints prepared as described above, a test of the degree of wear of the coating film and the adhesion of aquatic organisms was performed in the following manner. <Degree of Consumption of Coating Film> Each of the antifouling coating materials and antifouling paints of Examples 1 to 10, Reference Examples 1 to 2, Comparative Examples 1 to 4 and Comparative Examples 6 to 7 were respectively 70 × 150 Apply to a × 2mm rigid vinyl chloride plate with an applicator so that the dry film thickness becomes 100 μm, attach it to a rotating drum placed in seawater, and rotate at a peripheral speed of 10 knots to reduce the consumable film thickness for one month. It was measured. Table 5 shows the results.
Shown in <Adhesiveness of aquatic organisms> The antifouling coating materials and antifouling paints of Examples 1 to 10, Reference Examples 1 to 2, Comparative Examples 1 to 4 and Comparative Examples 6 to 7 were respectively used as antirust paints. A sample was prepared by applying the resulting composition to a 100 × 300 × 3 mm copper plate coated with such that the dry film thickness was 150 to 200 μm. Each of these samples and an untreated sample as Comparative Example 5 were submerged in the sea off Hiroshima Bay and Miyajima, and the area of attachment of aquatic organisms was examined every six months. Table 6 shows the adhesion area of each sample in percentage. [Table 5] [Table 6] <Adhesiveness of aquatic organisms> A mesh in which the antifouling coating materials and the antifouling paints of Examples 1 and 5 and Comparative Examples 1 and 4 were respectively attached to a 50 × 50 cm polyvinyl chloride resin frame. A sample was prepared by dip coating a polyester fishing net having a size of 7 knots. These samples and an untreated sample as Comparative Example 5 were each submerged in the sea of Toyama Bay, and the state of attachment of aquatic organisms was checked every two months. Table 7 shows the results. [Table 7] As shown by the results of each test, the antifouling coating material using the copolymer of the present invention exhibits stable antifouling properties over a long period of time. The copolymer for an antifouling coating material of the present invention has an improved hydrophilicity by hydrolyzing a triorganosilyl group in a side chain, and has a controlled solubility in water, that is, self-polishing. As a result, excellent antifouling effect can be exhibited without using an organic tin compound or an organic tin-containing copolymer which affects the environment. Therefore, the copolymer for an antifouling coating material of the present invention is effective in preventing contamination by aquatic organisms such as underwater structures, fishing nets, and ship bottoms.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nobuhiro Saito 133 Nishishinmachi, Ota City, Gunma Prefecture Toshiba Siri Cone Co., Ltd. 72) Inventor Masayuki Hatanaka 133 Nishishinmachi, Ota-shi, Gunma Toshiba Silicon Cone Co., Ltd. (56) References Tables Sho 60-500452 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) C09D 143/04 C08F 220/10 C08F 230/08 C09D 5/14 C09D 133/04

Claims (1)

(57) [Claims] The following general formula (Wherein, R ¹ is a hydrogen atom or a methyl group, R ² , R ³ ,
R ⁴ represents a monovalent hydrocarbon group selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, and a phenyl group), at least one unsaturated triorganosilyl monomer represented by the following formula: And a polymer containing at least one organic monomer selected from (meth) acrylic and vinyl compounds and having a degree of polymerization of not more than 190 and containing no tin-containing copolymer for an antifouling coating material. Copolymer. 2. ^{2. The} copolymer for an antifouling coating material according to claim 1, wherein R ² , R ³ and R ⁴ are all butyl groups. 3. ^{2. The} copolymer for an antifouling coating material according to claim 1, wherein ^{two of} R ² , R ³ and R ⁴ are methyl groups, and the remainder is an alkyl group having 6 or more carbon atoms. 4. The copolymer for an antifouling coating material according to any one of claims 1 to 3, wherein the amount of the unsaturated triorganosilyl monomer among the monomers of the copolymer is 10 to 95% by weight.