Marine antifouling paint based on silyl acrylate copolymer synthesis

Abstract

This invention involves the production of marine anti-fouling paint using the synthesis of silyl acrylate copolymers. One of the most effective anti-algae or anti-fouling paints was self-polishing paints based on acrylate resins containing tributyl tin, which were banned due to the toxicity of their tin compounds. One of the best-introduced alternatives is self-polishing paints based on silyl acrylate copolymers, but their performance is subpar and they have a shorter lifespan. In this invention, silyl acrylate copolymers in a controlled structure, including at least one soft monomer such as butyl acrylate, ethyl acrylate, etc., at least one hard monomer such as methyl methacrylate, 2-methoxyethyl methacrylate, etc. and at least one functional monomer such as triisopropyl silyl acrylate, triisopropyl silyl methacrylate, tertiary-butyl dimethyl silyl methacrylate, and tri-N-butyl silyl methacrylate were synthesized in which monomers or hard monomers were gradually added to the reactor in 2-6 hours.

Description

Marine Antifouling Paint based on Silyl Acrylate Copolymer Synthesis

[0001] The invention is focused on enhancing the production process of marine anti-fouling paint by synthesizing silyl acrylate copolymers. Traditionally, a popular type of anti-fouling paint, called self-polishing paint, relied on acrylate resins containing tributyl tin. However, it was banned due to the toxicity of its tin compounds. While self-polishing paints based on silyl acrylate copolymers were introduced as an alternative, they were found to have inferior performance and a shorter lifespan.

[0002] This innovation involves the synthesis of silyl acrylate copolymers with a carefully controlled structure, incorporating at least one soft monomer such as butyl acrylate or ethyl acrylate, at least one hard monomer such as methyl methacrylate or 2-methoxyethyl methacrylate, and at least one functional monomer such as triisopropyl silyl acrylate, triisopropyl silyl methacrylate, tertiary-butyl dimethyl silyl methacrylate, and tri-N-butyl silyl methacrylate. Furthermore, the method involves the gradual addition of monomers or hard monomers to the reactor over 2-6 hours. This approach aims to improve the overall performance and lifespan of marine anti-fouling paint while addressing environmental and toxicity concerns.

[0003] C09D 5 / 16

[0004] KR1020110029023

[0005] ANTIFOULING PAINT COMPOSITION WITH SMALL COATING FILM THICKNESS WITH LITTLE ENVIRONMENTAL HARMFULNESS

[0006] An antifouling paint composition is provided to ensure no cuprous oxide, to control low wear rate of an antifouling coating film, and to secure long-term anti-fouling property in a low coating film thickness. CONSTITUTION: An antifouling paint composition includes, based on 100 parts by weight of the total paint composition, (A) 10 ~ 50 parts by weight of a copolymer consisting of (a) 10 ~ 60 weight% of metal-containing ester monomer, (b) 1 ~ 50 weight% of silyl(meth)acrylate, abd (c) 5 ~ 70 weight% of acryl or vinyl-based unsaturated monomer capable of radical polymerization, as a binder; (B) 0.5 ~ 20 parts by weight of silane, silane coating additive or their mixture; (C) 0.1 ~ 30 parts by weight of 4,5-dichloro-2-octyl-4-isothiazoline-3-one encapsulated with an organic antifouling agent, 2-p-chlorophenyl-3 cyano-4-bromo-5-trifluoromethylpyrrol or their mixture.

[0007] The mentioned invention and our claimed one are similar in many ways but they also have differences, forexample one of them is that the mentioned patent coprises zinc oxide, copper oxide, calcium oxide, or anhydride while the copper oxide is toxic for sea species and our formula is more environmentally friendly.

[0008] CN101117463

[0009] METHOD FOR PREPARING ANTI-FOULING PAINT

[0010] A preparation method of antifouling paint is provided, wherein toluene and azobisisobutyronitrile are added into a reactor provided with a stirrer, a condenser, a thermometer, a drop-adding device, a nitrogen introducing pipe and a heating sleeve, heated and stirred under 80 DEG C in nitrogen flow, and the heat is preserved; butyl acrylate, methyl methacrylate, N-(4-hydroxy-3-methoxy-benzyl)-acrylamide and the mixture of ethyl acrylate and dimethylformamide are added into the reactor drop by drop within 2 hours, and meanwhile the mixture of azobisisobutyronitrile and toluene is simultaneously added in drop by drop; after the reaction solution is stirred for 3 hours under the same temperature, azobisisobutyronitrile is added in, and the reaction solution is stirred for 3 hours again under the same temperature, obtaining the colorless and transparent copolymer of the N-(4-hydroxy-3-methoxy-benzyl)-acrylamide. The present invention has the advantages of the capability of preventing marine organisms being attached to the surface of net utensils, ships and coastal facilities, good antifouling performance, no crack and peeling.

[0011] Their ingredients are similar but there is difference between their methods of handling them, like we have a cooling phase at the end of our process but the mentioned antifouling product remains at a high temperature.

[0012] GB1124297

[0013] IMPROVED ANTI-FOULING COMPOSITION

[0014] An anti-fouling paint comprises (a) a polymer vehicle having organo-tin radicals chemically combined therein and (b) a water-soluble pigment, the ratio of water-soluble pigment to vehicle being at least 3 : 1 by weight. The pigment is preferably one toxic to marine organisms, e.g. cuprous oxide, copper aceto-arsenite, zinc oxide and zinc chromate. The organo-tin radicals in the polymer may be provided by a salt of an a ,b -unsaturated acid and an organotin group -SnR1R2R3, where R1, R2 and R3 are the same or different and may be n- or isopropyl, n-butyl, n-amyl or phenyl, e.g. by tri-n-butyl tin methacrylate or tri-n-butyl tin acrylate. The polymer may be a copolymer of such a monomer with methyl methacrylate, isobutyl methacrylate or styrene. A plasticizing monomer, e.g. 2-ethylhexyl acrylate, n-butyl acrylate or n-butyl methacrylate may also be present in the copolymer and / or a plasticizer such as di-butyl or di-octyl phthalate is incorporated in the paint. In the examples, co-polymers of tri-n-butyl tin methacrylate and methyl methacrylate and of these monomers with n-butyl acrylate are prepared in solution in xylene and 4-methoxy-4-methyl-pentan-2-one or toluene. Paints are prepared by blending the copolymer solutions with cuprous oxide and / or zinc oxide and other ingredients selected from iron oxide, clay, di-butyl phthalate, di-2-ethylhexyl phthalate, toluene, xylene and solvent naphtha.

[0015] While both our claimed invention and the mentioned patent offer a formula for anti fouling paint, their processes and ingredients are different. They use harmful ingredient such as tin compounds but our method does not, and is environmentally friendly.

[0016] CN101250378

[0017] SILICONE-ACRYLATE LOW SURFACE ENERGY OCEAN ANTI-FOULING PAINT AND PREPARATION METHOD THEREOF

[0018] The invention relates to a silicone-acrylic low surface energy marine anti-fouling paint and the process for preparation, which relates to a marine anti-fouling paint. The invention provides a silicone-acrylic low surface energy marine anti-fouling paint with lower surface energy which can keep environmental protection property, economy and excellent dust-proof effect, can be permanently used, and utilizes a novel multi-component silicone-acrylic block polymer to be base material and the process for preparation. The silicone-acrylic low surface energy marine anti-fouling paint is remixed by base material, pigments, additives and paint solvent, wherein the base material is dimethyl silicone polymer-b-polymethyl methacryate-b-poly butyl methacrylate ternary silicone-acrylic block copolymer, and the additive is methyl silicone oil and di-n-octyl phthalate. Methyl silicone oil and di-n-octyl phthalate are mixed to get coating auxiliary A, dimethyl silicone polymer-b-polymethyl methacryate-b-poly butyl methacrylate ternary silicone-acrylic block copolymer and pigments are mixed to get a mixture B, the coating auxiliary A is added in the mixture B to get a mixture C, and the mixture C is dissolved in solvent solvent to get a mixture D, and products are got after stewing.

[0019] They both offer environmentally aware solutions but both their ingredient and processes vary. We did not use Methyl silicone oil and di-n-octyl phthalate and also we did not include stewing but heating and cooling.

[0020] United States Patent 6767978

[0021] Copolymers containing fluoro and silyl groups and their use in marine antifoulant composition

[0022] Copolymers of at least three monomer units selected from the group consisting of fluorinated acrylic (methacrylic) monomers, triorganosilylacrylic (e.g. trimethylsilyl methacrylate) monomers and acrylic monomers not containing an organosilyl moiety, (e.g. methyl methacrylate) and optionally containing from 0-5 weight percent of a cross-linking agent are novel compositions useful as polymeric binders in long life marine antifoulant coatings. The erosion rate and resistance to cracking of the copolymer of the present invention when used as a binder in a marine antifoulant paint is controlled by adjusting the proportions of each monomer and the amount of crosslinking agent in the copolymer of the present invention.

[0023] Both our claimed method and this mentioned composition use silicone based copolymers but our formula does not contain fluorinated monomers.

[0024] United States Patent 4593055

[0025] Erodible ship-bottom paints for control of marine fouling

[0026] A film-forming, water insoluble seawater erodible antifouling paint is described which is characterized by including a hydrolyzable organosilyl acrylate copolymer therein.

[0027] Both our claimed patent and this mentioned invention use organosilyl compolymers instead of the harmful organotin compounds. However, our formula is not limited to a certain quantity of the ingredients and can be used in various proportions, while their method is bound to the exact and detailed amount of each compiling ingredient.

[0028] United States Patent 9540521

[0029] Antifouling coating composition, antifouling coating film and antifouling substrate, and method for producing antifouling substrate

[0030] The antifouling coating composition according to the present invention includes a silylacrylic copolymer including a structural unit (1) derived from triisopropylsilyl methacrylate (i), a structural unit (2) derived from triisopropylsilyl acrylate (ii) and a structural unit (3) derived from a polymerizable monomer having a polymerizable double bond (iii), which excludes the above (i) and (ii), the silylacrylic copolymer satisfies specific requirements. Thus, an antifouling coating composition that is excellent in long-term storage stability and gives a coating film excellent in long-term antifouling properties and long-term water resistance can be provided.

[0031] Our claimed paint composition and this one are similar in their function and copolymer composition, but this antifouling substrate, unlike ours, includes elements such as plasticizers, pigments, an anti-sagging agent, a dehydrating agent and an anti-settling agent.

[0032] United States Patent 6458878

[0033] SILYL (METH) ACRYLATE COPOLYMERS, PROCESSES FOR PREPARING THE SAME, ANTIFOULING PAINT COMPOSITIONS

[0034] Disclosed is a silyl (meth)acrylate copolymer which comprises 20 to 80% by weight of (a) silyl (meth)acrylate constituent units (I), 0.01 to 40% by weight of (b) acrylic unsaturated monomer constituent units (II) and 5 to 79.9% by weight of Ĉ unsaturated monomer constituent units other than the constituent units (a) and (b). Also disclosed is a process for preparing the silyl (meth)acrylate copolymer, an antifouling paint composition comprising the copolymer, a coating film formed from the paint composition, a hull with the coating film and an antifouling method using the paint composition.

[0035] This mentioned patent and our claimed method both have a primary focus on creating a non-toxic and long-term solution. However, this one proposes various additives and substitutes such as alkyl, aryl or halogen atom, chlorine atom or phenoxy group, which are not part of our formula. Moreover, our heating and mixing and cooling mechanisms are not part of the process in the forementioned invention.

[0036] United States Patent Application 20180094092

[0037] COPOLYMER OF TRIISOPROPYLSILYL (METH)ACRYLATE WITH (METH)ACRYLIC ACID DERIVATIVE AND MAKING METHOD

[0038] A copolymer of triisopropylsilyl (meth)acrylate with a (meth)acrylic acid derivative having a Mn of 6,000-100,000 and a Mw / Mn of up to 2.0 is provided. A paint composition comprising the copolymer and a relatively small amount of an organic solvent has a low viscosity.

[0039] This method resembles our claimed patent in terms of the copolymer acrylate base and a few of the components like aromatic solvents, but our formula offers a more comprehensive process for the anti fouling paint as the final product. Also our method does not include toxic components such as heavy metal salts.

[0040] United States Patent 10131799

[0041] Antifouling coating composition and its use on man-made structures

[0042] The invention pertains to an antifouling coating composition comprising a copper acrylate polymer, 2-(p-chlorophenyl)-3-cyano-4-bromo-5-trifluoromethyl pyrrole (tralopyril), and solvent, with the coating composition being substantially free of further biocidal compounds, wherein the copper acrylate polymer is present in an amount of 60-99 wt. % and the tralopyril is present in an amount of 0.1-30 wt. %, the weight percentages for copper acrylate polymer and tralopyril being calculated on the dry weight of the coating composition. In one embodiment, the coating composition comprises 30-70 wt % of solvent, the weight percentage of solvent being calculated on the wet weight of the coating composition. It has been found that the coating composition according to the invention combines a good antifouling performance against both weed and shell fouling, for at least 12 months, i.e. a yacht season, with a high gloss finish, and, when a suitable application method is used, a smooth and level surface.

[0043] This patent and our claimed invention both feature a copolymer acrylate base for their anti fouling solution and minimize the use of toxic material, but the mechanisms and the ingredients vary. For example, we use a method of adding, mixing, heating and cooling which they do not. Also their formula contains tralopyril as the biocide component while ours does not.

[0044] United States Patent 4654380

[0045] Marine anti-fouling paint

[0046] A marine anti-fouling paint capable of becoming smoother in use on a ship's hull moving through sea water comprises an effective amount of marine biocide and, as the film-forming binder, a polymer containing diorganotin moities linked to the polymer by carboxylate linkages. The binder is preferably a copolymer of units of a diorganotin salt of an olefinically unsaturated carboxylic acid of the formula: ##STR1## where R' is an olefinically unsaturated group, each group R is a monovalent organic radical linked to the tin atom by a carbon-tin bond and X represents an electronegative group linked to the tin atom by an atom other than carbon, together with units of at least one olefinically unsaturated comonomer.

[0047] This invention has a similar function as our final product but the compounds and the process of preparing the solution are different. For instance, they use a copolymer of units of a dialkyltin salt of an olefinically unsaturated carboxylic acid, while our formula uses a silylacrylate based resin and three types of monomers to achieve the ideal coating film results.

[0048] A silyl acrylate resin consisting of various monomers is used to make self-polishing marine antifouling paints. The resin is prepared using 3-5 monomers to ensure specific properties such as solvent solubility, film formation, hydrolysis in alkaline conditions, and the ability to form a polyelectrolyte and dissolve in seawater. Soft and hard monomers are used to adjust the glass transition temperature and mechanical strength of the paint film. The resin is made of at least one functional monomer, added concurrently and gradually to the reactor, resulting in the ability to self-polish uniformly.

[0049] One of the most effective anti-algae or anti-fouling paints used to be self-polishing paints based on tributyltin acrylate resins, which during the polishing process, introduced tin compounds into the sea water. Due to the toxicity of tin compounds and its harmful effects on non-target marine organisms, the production of paints based on this resin was banned in 2001. Since then, a lot of research has been done to develop alternative paint with a similar function. One of the best introduced alternatives are self-polishing paints based on silyl acrylate copolymers, but their performance is weaker and they have a shorter lifespan.

[0050] Among the flaws of these paints, we can mention the variable wear rate (self-polishing) in working conditions, as well as unfavorable performance in dealing with the accumulation of biofouling on the surface of vessels and structures in static conditions. The most important factors affecting the paint are the properties of the silyl acrylate copolymer, including hydrolysis rate, water absorption rate, glass transition temperature, and permeability. The mentioned properties have a direct relationship with the structural characteristics of the silyl acrylate copolymer, including the average and distribution of the molecular mass, the proportion of monomers and their arrangement, which depends on the method and conditions of the synthesis reaction. The purpose of this invention is to make an anti-fouling paint with a certain efficiency using the optimization of the resin structure.Solution of Problem

[0051] In this patent, first, a silylacrylate copolymer was synthesized in order to make an antifouling (anti-algae) paint. 3-5 monomers from the family of acrylic acid or methacrylic acid esters were used to make the copolymer. Also, at least one type of solvent and one type of radical initiator were used.

[0052] The reason for using 3-5 types of monomers from the family of acrylic acid and methacrylic acid esters is to obtain a copolymer with these characteristics (a) the ability to dissolve in organic solvents, (b) the ability to form a uniform film, (c) having a glass transition temperature in the range of 15-55 degrees Celsius, (d) ability to be hydrolyzed in alkaline environment, (e) ability to form polyelectrolyte soluble in sea water. The monomers used include at least one soft monomer such as butyl acrylate, ethyl acrylate, etc., at least one hard monomer such as methyl methacrylate, 2-methoxyethyl methacrylate, etc., and at least one functional monomer such as triisopropyl silyl acrylate, triisopropyl silyl methacrylate, tertio-butyl dimethyl silyl methacrylate, tri-N-butyl silyl methacrylate, etc. The amount of soft monomers in the copolymer is in the range of 4-20% by weight, the amount of hard monomers is in the range of 30-60% by weight and the amount of functional monomers is in the range of 15-45% by weight.

[0053] The initiator is used to generate radicals and start the polymerization reaction, which was used from the family of azo compounds such as azobisisobutyronitrile and azodi (2-methylbutyronitrile).

[0054] Solvents are used to control the viscosity of the copolymer, control the temperature, and also help ease mixing. The solvent used in the production of copolymer is from the family of aromatic solvents such as toluene and xylene or aliphatic solvents such as methyl ethyl ketone and butyl acetate or a mixture of aliphatic and aromatic solvents.

[0055] The set-up used to make copolymer includes a three-hole reactor equipped with coolant, oil bath, thermometer and magnetic stirrer.

[0056] First, part of the solvent (i.e. 30-60% solvent) along with soft monomers and functional monomers entered the reactor. Then, to remove oxygen, it was placed under nitrogen gas pressure for 30 minutes and stirred at a speed of 300-500 rpm and the mixture was heated until it reached the synthesis temperature (60-90°C). After that, the hard monomer or the mixture of hard monomers along with the initiator and the rest of the solvent were gradually added to the reactor at a constant speed using an injection pump in the span of 2-6 hours.

[0057] The gradual injection of monomer or hard monomers leads to the formation of a copolymer with a random arrangement of monomers, which leads to the uniformity of the copolymer structure.

[0058] The gradual injection of the initiator leads to a narrowing of the molecular mass distribution.

[0059] Mixing and injection of nitrogen gas continued throughout the reaction time. After finishing the injection of hard monomer mixture, initiator and remaining solvent, the reaction continued for another 2-4 hours. After that, the mixing was stopped and the reactor was cooled down.Advantage Effects of the Invention

[0060] The advantages of this invention patent compared to similar formulas include:

[0061] 1- Obtaining silylacrylate copolymers with controlled structure by injecting monomers or hard monomers gradually.

[0062] 2- Making copolymers with narrow molecular mass distribution by injecting the initiator gradually.

[0063] Shows a flowchart of the related chemical process and its steps.

[0064] dispays a flowchart in which the steps of the chemical operation are mentioned:

[0065] 1- Part of the solvent enters the reactor along with soft monomers and functional monomers.

[0066] 2- Nitrogen gas is injected into the reactor for 30 minutes and the contents of the reactor are mixed at a speed of 300-600 rpm. At the same time, the mixture is heated until it reaches the synthesis temperature.

[0067] 3- Monomer or mixture of hard monomers along with the initiator and the remaining solvent is added to the reactor gradually and at a constant speed using an injection pump in a time frame of 2-6 hours.

[0068] 4- The mixing process along with nitrogen injection continues for another 2-4 hours.

[0069] 5- The mixing is stopped and the reactor cools down.

[0070] 6- Silylacrylate copolymer solution is obtained.Examples

[0071] The obtained copolymer can be mixed with anti-algae compounds such as copper oxide and be applied on the surface of ships and underwater structures to prevent the formation of fouling organisms.

[0072] The resin made in this process can be used in making marine anti-fouling paints, and It can be used in the construction of ships and other floating vessels.

Claims

A silyl acrylate resin is made which consists of methyl methacrylate, butyl acrylate, triisopropyl silyl acrylate, and tertio-butyl dimethyl silyl methacrylate, which is used to make self-polishing marine antifouling paints.According to claim 1, the resin is prepared using 3-5 monomers so that the resin can dissolve in an organic solvent, the ability to form a film, the ability to hydrolyze in alkaline conditions, the ability to create a polyelectrolyte, and dissolve in seawater.According to claim 1, at least one soft monomer such as butyl acrylate, ethyl acrylate, etc. is used to make the resin, which helps to adjust the glass transition temperature of the resin.According to claim 1, at least one hard monomer such as methyl methacrylate, 2-methoxyethyl methacrylate, etc. is used to make the resin, which helps to adjust the glass transition temperature and the mechanical strength of the antifouling paint film.According to claim 1, the resin is made of at least one functional monomer such as tri isopropyl silyl acrylate, tri isopropyl silyl methacrylate, tertiary-butyl dimethyl silyl methacrylate and trinomial butyl silyl methacrylate which helps give the resin the ability to be hydrolyzed in an alkaline environment and the ability to form a polyelectrolyte.According to claim 1, for resin synthesis, the mixture of soft and functional monomers is added simultaneously at the beginning of the synthesis reaction and the mixture of hard monomers is added gradually to the reactor. This helps in their uniform distribution in the copolymer chain due to the higher activity ratio of the hard monomers.According to claim 1, the silyl acrylate copolymer made through this process can self-polish uniformly.

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