MXPA99001295A

MXPA99001295A - Increasing the self-polishing properties of antifouling paints

Info

Publication number: MXPA99001295A
Application number: MXPA/A/1999/001295A
Authority: MX
Inventors: Sijbren Stienstra Pieter
Original assignee: Sigma Coatings Bv
Priority date: 1996-08-07
Filing date: 1999-02-04
Publication date: 2000-01-01

Abstract

Substituted 1,4,2-oxathiazines and their mono- and di-oxides, disclosed in WO-A-9505739, are used as additive to increase the self-polishing properties of antifouling paints. The additive is used in an amount of 0.5 to 9.9 wt.%, based on the total weight of the dry mass of the composition, preferably 1 to 8 wt.%, most preferably 2 to 4 wt.%. The preferred additive is 3-(3,4-dichlorophenyl)-5, 6-dihydro-1,4,2-oxathiazine dioxide.

Description

INCREASING THE SELF-POLISHING PROPERTIES OF ANTI-CRUSHING PAINTS DESCRIPTION OF THE INVENTION The present invention relates to the increase of self-polishing properties of marine antifouling paints. More particularly, this relates to the use of specific additives that increase the erosion rate of self-polishing anti-fouling paints. Antifouling paints for boat hulls comprise an important subclass of paints prepared with binders which are copolymers that release a biocide after hydrolysis, the copolymers that remain after the loss of the biocide are sufficiently soluble in water to be washed from the surface. . The slow dissolution of the copolymer helps keep the surface of the coating uniform, hence the name "self-pollinator" given to those paints. Indeed, it has been demonstrated for a long time that the speed and fuel consumption are strongly influenced by the roughness of the coating. The formulations of self-polishing coatings are generally based on polymeric binders incorporating a trialkyltin carboxylate group linked to the polymer backbone through the use of trialkyltin (meth) acrylate comonomers. The hydrolysis on the surface releases a toxic of trialkyltin that contributes to the antifouling properties, and leaves a more hydrophilic structure which can dissolve in the sea water, contributing to the self-polishing properties. The first anti-fouling self-polishing paints are based on copolymers containing high amounts of trialkyltin (meth) acrylate copolymers. GB-A-1457690 discloses one of the first commercial compositions and claims a paint wherein the copolymer forming the film contains from 50 to 80% by weight of units of triorganotin salt of olefinically unsaturated carboxylic acid; The claimed composition also contains an organic hydrophobic retarder to retard the ratio of ion exchange between seawater and the copolymer. More recently, environmental concerns have led to a reduction in the amount of comonomer containing tin in marine paints. In fact, toxic concentrations can accumulate enough to affect life in ports and even in bays; In addition, the potential for entry of tin into the food chain can affect humans. The reduction in the amount of tin-containing comonomer has, however, led to a reduction in the solubility of the remaining structure, potentially affecting the self-polishing properties. In this way, the situation has been completely reversed since the early days of self-polishing anti-fouling paints, and there is now a need in the art for ways to increase self-polishing properties. In the present it has now been surprisingly found that certain oxathiazines can be used as an additive in anti-fouling paints to enhance the self-polishing properties thereof. Those oxathiazines are described in O-A-9505739, the disclosure of which is incorporated herein. These are substituted 1, 4, 2-oxathiazines and their mono or dioxides, wherein: the substituent in the 3-position represents (a) phenyl; phenyl substituted with 1 to 3 substituents independently selected from hydroxyl, halo, C1-C12 alkyl, C5-6 cycloalkyl, trihalomethyl, phenyl, Cl-5 alkoxy, Cl-5 alkylthio, tetrahydropyranyloxy, phenoxy, Cl-alkylcarbonyl 4, phenylcarbonyl, Cl-4 alkylsulfinyl, carboxy or its alkali metal salt, Cl-4alkyloxycarbonyl, Cl-4alkylaminocarbonyl, phenylaminocarbonyl, tolylaminocarbonyl, morpholinocarbonyl, amino, nitro, cyano, dioxolanyl, or alkyloxyiminomethyl Cl-4; naphthyl; pyridinyl; thienyl, furanyl; or thienyl or furanyl substituted with one to three substituents independently selected from Cl-4 alkyl, Cl-4 alkyloxy, Cl 4 alkylthio, halo, cyano, formyl, acetyl, benzoyl, nitro, Cl-4 alkyloxycarbonyl, phenyl , phenylaminocarbonyl and Cl-4 alkyloxyiminomethyl; or (b) a substituent of the generic formula wherein X is oxygen or sulfur; And it is nitrogen, CH or C (Alkoxy Cl-4); and the C6 ring may have an alkyl substituent of Cl-4; - A substituent selected from C 1-4 alkyl or benzyl may be present in the 5 or 6 position. WO-A-9505739 discloses that anti-fouling paint compositions may contain from 10 to 75% by weight of the active ingredient, based on to the total weight of the dry mass of the composition. The additive should be used in an amount of 0.5 to 9.9% by weight, based on the total weight of the dry mass of the composition, preferably 1 to 8% by weight, more preferably 2 to 4% by weight. Using oxatiazines according to O-A-9505739 as additives in an amount of 0.5 to 9. 9% by weight, based on the total weight of the dry mass of the composition, in self-polishing antifouling paints, it has been unexpectedly found that the paints not only have regular antifouling behavior at all times but also exhibit an evenly improved uniform layer on the surface of the painting. It is surprising that the oxathiazines described in WO-A-9505739 can have a favorable influence on the self-polishing properties since they have a very low solubility in water which is hitherto believed to have a harmful influence on those properties. It is additionally surprising that those oxathiazines can have an effect on self-polishing anti-fouling paints when WO-A-9505739 teaches that anti-fouling paints should contain the oxathiazines in a much greater amount, ie in an amount of 10 to 75% by weight, in based on the total weight of the dry mass of the composition. The self-polishing paint composition according to the invention comprises the usual components and at least one compound according to WO-A-9505739 in an amount of 0.5 to 9.9% by weight. According to the first embodiment, the self-polishing paint composition comprises: (i) a trialkyltin (meth) acrylate copolymer; (ii) at least one compound according to WO-A-9595739, in an amount of 0.5 to 9.9% by weight, based on the total weight of the dry mass of the composition. The trialkyltin (meth) acrylate copolymers are well known in the self-polishing paints art from GB-A-1457690 and thus need not be described herein. According to a second embodiment, the self-polishing paint composition comprises: (i) a first component selected from one or more rosin-based components; (ii) a (co) polymer as a binder; (iii) at least one moderately soluble metalliferous pigment; (iv) at least one compound according to WO-A-9505739, in an amount of 0.5 to 9.9% by weight, based on the total weight of the dry mass of the composition. According to a third embodiment, the self-polishing paint composition comprises: (i) a first "component selected from one or more rosin-based components; (ii) a hydrophilic binder; (iii) at least one moderately soluble metalliferous pigment; (iv) at least one compound according to WO-A-9505739, in an amount of 0.5 to 9.9% by weight, based on the total weight of the dry mass of the composition.Appropriate binders for use in such compositions they are well known in the art, they are exemplified by the copolymers described in EP-A-289481 and EP-A-526441.

According to a second embodiment, the self-polishing paint composition comprises: (i) a (co) polymer based on copper acrylate; (ii) optionally, one or more components based on rosin; (iii) at least one moderately soluble metalliferous pigment; (iv) at least one compound according to WO-A-9505739, in an amount of 0.5 to 9. 9 by weight, based on the total weight of the dry mass of the composition. Copper acrylate (co) polymers are well known in the art; they are exemplified by those described in US-A-5236493; Rosin is a freely used term, which indicates the result of a harvest of gum exudations from surface cuts made in certain tree species. Rosin is usually defined as the product obtained from the pines; Similar products include congo, damar, kauri and manila gums. Other processes for obtaining rosin include dissolving rosin from pine stump wood after the trees have been felled, or retreating a byproduct of the Kraft papermaking process to produce rosin oil tallow. Colophony originating from pine is preferably chosen, although similar products can be contemplated on the condition that they have a similar hydrophilic / lipophilic balance. The main component (approximately 80% by weight) of the rosin is abietic acid, also called sylvic acid (Chemical Abstracts Service Registry Number: 514-10-3), which can be used in place of the rosin. The preferred rosin-based components are the same rosin, its copper or zinc derivatives, subsequently named in the present copper resinate and zinc resinate, other salts of resinates having a comparable solubility, or mixtures thereof. The salts are prepared by any known methods, typically by metathesis with the metal carbonate, oxide, hydroxide or hydroxycarbonate (either in situ or in a separate reaction). In some cases, the transformation of abietic acid into salts thereof can improve the properties such as melting point, hardness, durability, resistance to water or solvent. The paint compositions according to the invention also comprise at least one moderately soluble metalliferous pigment; they may additionally comprise one or more pigments which are highly insoluble in seawater and / or other biocides. The metalliferous pigment soluble in seawater is exemplified by cuprous thiocyanate, cuprous oxide, zinc oxide, cupric acetate meta arsenate, or zinc chromate. The paint preferably includes at least one metalliferous pigment selected from zinc oxide, cuprous oxide, cuprous thiocyanate and pigments. These pigments have a solubility in seawater in such a way that the pigment particles do not survive on the surface of the paint. The pigment has the effect of inducing total uniformity which relatively sea water exerts on the paint film, minimizing localized erosion and preferentially eliminating the outgrowths formed during the application of the paint. Mixtures of moderately soluble pigments can be used, the most preferred being a mixture of zinc oxide, which is more effective in inducing the gradual dissolution of the paint, with cuprous oxide and / or cuprous thiocyanate, which are more effective marine biocides, the mixture preferably comprising at least 25% by weight of oxide and / or cuprous thiocycle, the balance being zinc oxide. The paint composition may additionally contain a pigment which is highly insoluble in seawater, such as titanium dioxide or ferric oxide. Such highly insoluble pigments can be used in up to 40 weight percent of the total pigment component of the paint. Although the highly insoluble pigment has the effect of slowing the dissolution of the paint, it is highly desirable since it is very economical; this is an added advantage of this invention to allow inclusion of additional amounts of such highly insoluble pigment while retaining good self-polishing properties. The proportion of the pigment to the polymer is generally such as to give a pigment volume concentration of at least 25 percent, preferably at least 35 percent, in the dry paint film. The upper limit of the pigment concentration is the critical concentration of pigment volume. For example, paints having pigment volume concentrations of approximately 50 percent have been found to be very effective, for uniformity in seawater and to avoid fouling. EXAMPLES In all the examples, a copolymer of vinyl chloride and isobutyl ether commercially available as Laroflex MP 45 (Laroflex is a trademark of BASF) is used as an agglomerate. It is used as an additive that improves the self-polishing properties: in the examples according to the invention: an oxathiazine according to WO-A-9505739 wherein n = 2, R1 = H and R = 3,4-dichlorophenyl , [i.e., 3- (3,4-dichlorophenyl) -5,6-dihydro-l, 4,2-oxathiazine] dioxide, and - in the comparative examples: diuron. Self polishing paints are tested for their self polishing properties according to the following procedure. Steel discs of 20 cm diameter are first coated with a layer of dry film thickness of 220 μm of a commercially available anticorrosive paint based on carbon tar and epoxy resin. The antifouling paint is then applied as two layers having a total dry film thickness of about 250 μm. The discs are rotated in a tank filled with seawater continuously renewed at a temperature of 20 degrees Celsius; the circumferential speed of the discs is approximately 17 knots (31 km / h). Measurements are made after 7 months of storage, in 15 different places at 9 cm from each center of the disc, in a period of 177 days. The following average erosion proportions are given: Compositions (parts by volume excluding solvents) Example 1 2 3 4 A B (comparative) Colophony 31.4 31.7 32.4 35.5 31.7 32.4 Binder 15.4 15.7 16.1 17.6 15.7 16.1 Epoxidized oil 5.0 5.1 5.2 5.7 5.1 5.2 Cuprous oxide 24 26 27 16 6 27 Zinc oxide 3.0 5.5 6.0 9.0 5.5 6.0 Talco 3.0 3.0 3.0 3.0 3.0 3.0 Ti02 3.0 3.0 3.0 3.0 3.0 3.0 Bentonite 3.0 3.0 3.0 3.0 3.0 3.0 Additive (see text) 11.0 5.5 2.8 5.5 5.5 2.8 Erosion rate (um / month) 11 10 10 9 5 5 The composition calculated by weight is given below: Example 1 2 3 4 A B (comparative) Colophony 7 5 7. 1 7. 1 9 0 7. 1 7. 1 Binder 13.3 12.5 12.5 15.8 12.5 12.5 Epoxidized oil 1.9 1.8 1.9 2.4 1.8 1.9 Cuprous oxide 56.0 55.9 56.4 39.1 55.9 56.4 Zinc oxide 6. 6 11.3 12.0 20.9 11.3 12.0 Talc 3.2 3.0 2.9 3.4 3.0 2.9 Ti02 4.8 4.4 4.3 4.9 4.4 4.3 Bentonite 1.9 1.8 1.8 2.0 1.8 1.8 Additive (see text) 4.8 2.2 1.1 2.5 2.2 1.1 Total dry mass 100 100 100 100 100 100 Erosion rate (um / month) 28.7 26.7 25.9 32.5 26.7 25.9 The solvents consist of 1.25% by weight (calculated in the total dry mass) of ethanol and a mixture of xylene and methyl isoamyl ketone in a ratio of 3: 1.

Claims

CLAIMS 1. The use of substituted 1, 4, 2 -oxathiazines and their mono and dioxides as an additive to increase the self-polishing properties of antifouling paints, the substituent in the 3-position represents (a) phenyl; phenyl substituted with 1 to 3 substituents independently selected from hydroxyl, halo, C1-C12 alkyl, C5-6 cycloalkyl, trihalomethyl, phenyl, Cl-5 alkoxy, Cl-5 alkylthio, tetrahydropyranyloxy, phenoxy, Cl-alkylcarbonyl 4, phenylcarbonyl, Cl-4 alkylsulfinyl, carboxy or its alkali metal salt, Cl-4alkyloxycarbonyl, Cl-4alkylaminocarbonyl, phenylaminocarbonyl, tolylaminocarbonyl, morpholinocarbonyl, amino, nitro, cyano, dioxolanyl, or alkyloxyiminomethyl Cl-4; naphthyl; pyridinyl; thienyl, furanyl; or thienyl or furanyl substituted with one to three substituents independently selected from Cl-4 alkyl, Cl-4 alkyloxy, Cl-4 alkylthio, halo, cyano, formyl, acetyl, benzoyl, nitro, Cl-4 alkyloxycarbonyl, phenyl , Cl-4 phenylaminocarbonyl and alkyloxyiminomethyl; or (b) a substituent of the generic formula wherein X is oxygen or sulfur; And it is nitrogen, CH or C (Alkoxy Cl-4); and the C6 ring may have an alkyl substituent of Cl-4; a second substituent selected from alkyl of Cl-4 or the benzyl may be present in the 5 or 6 position, and the additive which is used in an amount of

0. 5 to 9.9% by weight, based on the total weight of the dry mass of the composition.
2. The use according to claim 1, characterized in that the additive is used in an amount of 1 to 8% by weight, based on the total weight of the dry mass of the composition.
3. The use according to claim 2, characterized in that the additive is used in an amount e 2 a 4% by weight, based on the total weight of the dry mass of the composition.
4. The use according to any of claims 1 to 3, characterized in that the additive is 3- (3,4-dichlorophenyl) -5,6-dihydro-1,4,4-oxathiazine dioxide.
5. The use according to any of claims 1 to 4, characterized in that the self-polishing paint composition essentially comprises (i) a trialkyltin (meth) acrylate copolymer; (ii) the additive. The use according to any of claims 1 to 4, characterized in that the self-polishing paint composition essentially comprises (i) a first component selected from one or more rosin-based components; (ii) a copolymer as a binder; (i ii) at least one moderately soluble metalliferous pigment; (iv) the additive. The use according to any of claims 1 to 4, characterized in that the self-polishing paint composition essentially comprises: (i) a first component selected from one or more components based on rosin; (ii) a hydrophilic binder; (iii) at least one moderately soluble metalliferous pigment; (iv) the additive. The use according to any of claims 1 to 4, characterized in that the self-polishing paint composition essentially comprises: (i) a (co) polymer based on copper acrylate; (ii) optionally, one or more components based on rosin; (iii) at least one moderately soluble metalliferous pigment; (iv) the additive. The use according to any of claims 6 to 8, characterized in that the self-polishing paint composition comprises cuprous oxide as representing at least 25% by weight of the moderately soluble metalliferous pigments.