EP0835290A1 - Antifouling paint - Google Patents
Antifouling paintInfo
- Publication number
- EP0835290A1 EP0835290A1 EP96922292A EP96922292A EP0835290A1 EP 0835290 A1 EP0835290 A1 EP 0835290A1 EP 96922292 A EP96922292 A EP 96922292A EP 96922292 A EP96922292 A EP 96922292A EP 0835290 A1 EP0835290 A1 EP 0835290A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- paint
- pigment
- binder
- pvc
- cpvc
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/16—Antifouling paints; Underwater paints
- C09D5/1687—Use of special additives
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/16—Antifouling paints; Underwater paints
- C09D5/1656—Antifouling paints; Underwater paints characterised by the film-forming substance
- C09D5/1662—Synthetic film-forming substance
Definitions
- the present invention relates to an antifouling paint for controlling and minimizing the attachment and growth of marine fouling organisms to those parts of various objects which are submerged in sea water, fresh water or brackish water.
- a common type of antifouling paint is that which contains a biocidal agent dispersed in a suitable binder or a mixture of binders .
- a commonly used biocidal agent is cuprous oxide. During use the biocidal agent will dissolve and be released to the surrounding water and will thus provide an antifouling property.
- antifouling paint is the so-called self polishing type.
- the antifouling agent which is chemically bound to the binder, gradually dissolves or hydrolyzes in water to release the antifouling agent.
- Well-known paints of this type are those which are based on acrylic polymers in which carboxyl groups have been esterified with organotin groups. During use the polymers will be hydrolyzed in sea water to release free trialkyltin compounds while carboxyl groups are formed in the polymer. The released trialkyltin compound will act as an antifouling agent .
- biocidal agents in paints.
- biocidal agents such as cuprous oxide or tin compounds or groups as described above, may have an undesired detrimental effect on the envi- ronment .
- antifouling paints which do not exhibit these undesired properties.
- an anti ⁇ fouling paint having no essential biocidal activity, which comprises a slightly soluble pigment having little or no biocidal activity, an essentially insoluble film-forming binder, the pigment volume concentration (PVC) being in the region of or above the critical pigment volume concentration (CPVC) , and optionally an organic or aqueous solvent.
- PVC pigment volume concentration
- CPVC critical pigment volume concentration
- the pigment will gradually dissolve and be removed from the surface of the paint together with any marine fouling organisms . Due to the rather high amount of pigment compared to the amount of binder, this effect may be considered as "chalking" which is not dependant on any biocidal effect. If the PVC/CPVC ratio is too low, the surface of the coating will form a continuous film with no pigment exposed on the surface, and no "chalking" effect will be obtained.
- Suitable binders are for instance selected from, but not limited to epoxy resin, alkyd resin, acrylic resin, vinyl resin, polyurethane, silicone, silicates and synthetic rubber.
- the binder may be formed from one or more components. With two or more components, these may react with each other when they are mixed. It is also possible to include a plasticizer and/or a co-binder to modify the properties of the essentially insoluble binder.
- the optional extender and other possible additives in particle form should be included as a part of the pigment .
- These may be ordinary paint additives such as silica dust or minor amounts of other pigments and, if desired, biocides. Normally biocides are not required but may be used if an enhanced antifouling effect is desired, i.e. a "chalking" as well as a biocidal effect.
- the optional plasticizer and co-binder should be included as a part of the binder when making said calculation.
- the PVC should be in the region of the CPVC, there will always be some pigment exposed to the surrounding water. If the PVC was lower, there might be formed a complete film without any pigment exposed to the water. Below the CPVC region film properties dominate the behaviour of the coating, and no "chalking" effect would be obtained, and marine fouling organisms may attach to the surface.
- the essential feature of the pigment is that it is slightly soluble so that some of it will continuously disappear from the surface of the coating. Some of the pig ⁇ ment will dissolve and pigment particles no longer bound into the coating will crumble away, or "chalk", by the movement of the water. This will ensure that no fouling organisms may attach to the surface.
- Any slightly soluble pigment may be used, such as, but not restricted to: metals, such as zinc, iron, aluminium; inorganic oxides and salts, such as calcium, magnesium and ammonium oxides and salts, in addition to zinc, iron and aluminium oxides and salts; organic salts; and glasses.
- the biocidal activity of the pigment should preferably not be greater than that of zinc oxide.
- the use of zinc compounds in combination with biologically highly active materials, such as organotin and cuprous oxide, is well known. In that case, the antifouling effects are due to biological activity of the organotin and cuprous oxide, and not to a "chalking" effect.
- an essentially insoluble pigment which will act as an extender. Such an extender is generally chosen to maintain the desired PVC, modify the solubility, and to control coating properties such as "chalking", film toughness, overcoatability, colour, costs, etc.
- Chrositting properties are related to the rate of solubility of the soluble pigment, which in turn is influenced by its intrinsic solubility, particle size, shape and surface area. Thus, a porous particle may result in a much higher solubility rate than a compact bead.
- the “chalking” may be increased by increasing the PVC, by increasing the solubility of the pig ⁇ ment and by increasing the surface area of the pigment particles.
- the “chalking” may also be increased by using a co-binder which is slightly soluble, and possibly also one or more plasticizers, so that more pigment may be exposed to the surrounding water.
- the paint of the invention may also contain conventional paint additives.
- Examples 1-4 Four different paints (Examples 1-4) containing varying amounts of acrylic resin as binder and zinc oxide as pigment were prepared and tested. Similarly, five paints (Examples 5-9) based on epoxy resin were prepared and tested. Panels coated with the paint were kept submerged in seawater for 3 months at a temperature of about 25°C. The composition of the paints as well as the test results will appear from the following table .
- control sample was a panel with gel coat only, i.e. the same as those used as substrate for the other examples.
- Example 10 and 11 Two paints (Examples 10 and 11) having the higher PVC/CPVC ratios of 1.3 and 1.5 respectively were also prepared and applied to the same type of substrate. These were not subjected to the same long time antifouling testing described above since it is obvious in view of the other tests that the antifouling effect will be satisfactory. However, the test panels were subjected to adhesion tests, and the durability of the films was found to be satisfactory.
- the PVC/CPVC ratio should not be higher than 1.5 and preferably not higher than 1.3, particularly less than 1.2.
- the PVC/CPVC ratio is in practice above 0.7, normally above 0.8, in particular above 0.9. Apparently the best balance between antifouling effect and durability is normally found when said ratio in the range 0.8-1.2. However, this will depend on several factors such as the type of polymer and pigment as well as the particle size of the latter.
- Plasticizer 9.5 10.7 13.1 15.7 12.0 8.0 (Chlorparaffin 42)
- Ad ⁇ osil 200 0.8 0.9 1.1 1.3 0.5 0.3
Abstract
Antifouling paint having no essential biocidal activity. It comprises a slightly soluble pigment having little or no biocidal activity, an essentially insoluble film-forming binder, the pigment volume concentration (PVC) being in the region of the critical pigment volume concentration (CPVC), and optionally an organic or aqueous solvent.
Description
ANTIFOULING PAINT
The present invention relates to an antifouling paint for controlling and minimizing the attachment and growth of marine fouling organisms to those parts of various objects which are submerged in sea water, fresh water or brackish water.
The attachment and growth of marine fouling organisms to ships, marine structures etc. cause considerable problems, and various antifouling paints are in use for controlling the attachment and growth of marine fouling organisms .
A common type of antifouling paint is that which contains a biocidal agent dispersed in a suitable binder or a mixture of binders . A commonly used biocidal agent is cuprous oxide. During use the biocidal agent will dissolve and be released to the surrounding water and will thus provide an antifouling property.
Another type of antifouling paint is the so-called self polishing type. In such a paint, the antifouling agent which is chemically bound to the binder, gradually dissolves or hydrolyzes in water to release the antifouling agent. Well-known paints of this type are those which are based on acrylic polymers in which carboxyl groups have been esterified with organotin groups. During use the polymers will be hydrolyzed in sea water to release free trialkyltin compounds while carboxyl groups are formed in the polymer. The released trialkyltin compound will act as an antifouling agent . During recent years certain restrictions have been made with respect to the use of biocidal agents in paints. Thus, it has been found that in certain cases biocidal agents such as cuprous oxide or tin compounds or groups as described above, may have an undesired detrimental effect on the envi- ronment . There is accordingly a need for antifouling paints which do not exhibit these undesired properties.
We have now found a new principle which may be used in antifouling paints, and which is not uniquely dependant on any biocidal activity of components of the paint.
According to the present invention we provide an anti¬ fouling paint having no essential biocidal activity, which comprises a slightly soluble pigment having little or no biocidal activity, an essentially insoluble film-forming binder, the pigment volume concentration (PVC) being in the region of or above the critical pigment volume concentration (CPVC) , and optionally an organic or aqueous solvent. The terms "PVC" and "CPVC" are well known in the paint art. See e.g. "Principles of Paint Formulation", edited by R. Woodbridge, Blackie, Glasgow and London, p. 69-70, and "Protective Coatings" by Clive H. Hare, Technology Publishing Company, Pittsburgh, Pennsylvania, SSPC 94-17. p. 6-13.
During use the pigment will gradually dissolve and be removed from the surface of the paint together with any marine fouling organisms . Due to the rather high amount of pigment compared to the amount of binder, this effect may be considered as "chalking" which is not dependant on any biocidal effect. If the PVC/CPVC ratio is too low, the surface of the coating will form a continuous film with no pigment exposed on the surface, and no "chalking" effect will be obtained.
Suitable binders are for instance selected from, but not limited to epoxy resin, alkyd resin, acrylic resin, vinyl resin, polyurethane, silicone, silicates and synthetic rubber. The binder may be formed from one or more components. With two or more components, these may react with each other when they are mixed. It is also possible to include a plasticizer and/or a co-binder to modify the properties of the essentially insoluble binder.
When calculating the PVC/CPVC ratio, the optional extender and other possible additives in particle form should be included as a part of the pigment . These may be ordinary paint additives such as silica dust or minor amounts of other pigments and, if desired, biocides. Normally biocides are not required but may be used if an enhanced antifouling effect is desired, i.e. a "chalking" as well as a biocidal effect.
Similarly, the optional plasticizer and co-binder should be included as a part of the binder when making said calculation.
Since the PVC should be in the region of the CPVC, there will always be some pigment exposed to the surrounding water. If the PVC was lower, there might be formed a complete film without any pigment exposed to the water. Below the CPVC region film properties dominate the behaviour of the coating, and no "chalking" effect would be obtained, and marine fouling organisms may attach to the surface.
The essential feature of the pigment is that it is slightly soluble so that some of it will continuously disappear from the surface of the coating. Some of the pig¬ ment will dissolve and pigment particles no longer bound into the coating will crumble away, or "chalk", by the movement of the water. This will ensure that no fouling organisms may attach to the surface. Any slightly soluble pigment may be used, such as, but not restricted to: metals, such as zinc, iron, aluminium; inorganic oxides and salts, such as calcium, magnesium and ammonium oxides and salts, in addition to zinc, iron and aluminium oxides and salts; organic salts; and glasses.
The biocidal activity of the pigment should preferably not be greater than that of zinc oxide. The use of zinc compounds in combination with biologically highly active materials, such as organotin and cuprous oxide, is well known. In that case, the antifouling effects are due to biological activity of the organotin and cuprous oxide, and not to a "chalking" effect. Together with the slightly soluble pigment it is also possible to use an essentially insoluble pigment which will act as an extender. Such an extender is generally chosen to maintain the desired PVC, modify the solubility, and to control coating properties such as "chalking", film toughness, overcoatability, colour, costs, etc.
"Chalking" properties are related to the rate of solubility of the soluble pigment, which in turn is influenced by its intrinsic solubility, particle size, shape
and surface area. Thus, a porous particle may result in a much higher solubility rate than a compact bead.
The higher the fouling severity, the higher the "chalking" should be. The "chalking" may be increased by increasing the PVC, by increasing the solubility of the pig¬ ment and by increasing the surface area of the pigment particles. The "chalking" may also be increased by using a co-binder which is slightly soluble, and possibly also one or more plasticizers, so that more pigment may be exposed to the surrounding water.
It may be advantageous to use a pigment which has an anticorrosive effect, such as metallic zinc, since the substrate upon which the antifouling paint is applied, will then also be protected against corrosion and not only against fouling.
In addition to the different components mentioned above, the paint of the invention may also contain conventional paint additives.
Four different paints (Examples 1-4) containing varying amounts of acrylic resin as binder and zinc oxide as pigment were prepared and tested. Similarly, five paints (Examples 5-9) based on epoxy resin were prepared and tested. Panels coated with the paint were kept submerged in seawater for 3 months at a temperature of about 25°C. The composition of the paints as well as the test results will appear from the following table .
The control sample was a panel with gel coat only, i.e. the same as those used as substrate for the other examples.
Two paints (Examples 10 and 11) having the higher PVC/CPVC ratios of 1.3 and 1.5 respectively were also prepared and applied to the same type of substrate. These were not subjected to the same long time antifouling testing described above since it is obvious in view of the other tests that the antifouling effect will be satisfactory. However, the test panels were subjected to adhesion tests, and the durability of the films was found to be satisfactory. The PVC/CPVC ratio should not be higher than 1.5 and preferably not higher than 1.3, particularly less than 1.2. The PVC/CPVC ratio is in practice above 0.7,
normally above 0.8, in particular above 0.9. Apparently the best balance between antifouling effect and durability is normally found when said ratio in the range 0.8-1.2. However, this will depend on several factors such as the type of polymer and pigment as well as the particle size of the latter.
PANEL TEST AT MARINE FACILITY
Series A Series B Series C
FORMULATION COMPONENTS VOLUM% DRY FILM Example
Control
1 2 3 4 5 6 7 8 9 10 11
Acffyl film forming resin 35.1 39.4 48.3 58.2 20.4 13.5 (Neocryl B-725)
Plasticizer 9.5 10.7 13.1 15.7 12.0 8.0 (Chlorparaffin 42)
10 Epoxy Resin 1001-type 26.4 31.0 37.6 42.1 47.8
Amine Curing Agent 13.8 16.3 19.7 22.1 25.1
Adδosil 200 0.8 0.9 1.1 1.3 0.5 0.3
Zinc Oxide 54.6 49.0- 37.5 24.8 59.8 52.7 42.7 35.8 27.1 67.1 78.2
PVC/CPVC 1.1 1.0 0.8 0.6 1.1 1.0 0.8 0.7 0.5 1.3 1.5
RfiMults panel test
Total fouling ) 42 0 0 5 78 3 6 11 26 42
3 months Barnacles ) exposure 3 0 0 0 7 1 1 1 1 2
25 (area%) Algae ) 15 0 0 3 70 2 5 10 25 40
It should be noted that the test with acrylic resin was not carried out at the same time as the test with the epoxy re
Claims
1. Antifouling paint having no essential biocidal activity, characterised in that it comprises a slightly soluble pigment having little or no biocidal activity, an essentially insoluble film-forming binder, the pigment volume concentration (PVC) being in the region of the critical pigment volume concentration (CPVC) , and optionally an organic or aqueous solvent.
2. The paint of claim 1, characterised in that the PVC/CPVC ratio is in the range 0.7-1.5, preferably 0.8- 1.3, in particular 0.9-1.2.
3. The paint of any of claims 1-2, characterised in that it also contains an essentially insoluble pigment as an extender.
4. The paint of any of claims 1-3, characterised in that the essentially insoluble binder is formed from two or more components which react with each other upon mixing.
5. The paint of any of claims 1-4, characterised in that it contains a plasticizer and/or a co-binder.
6. The paint of any of claims 1-5, characterised in that the binder is selected from epoxy resin, alkyd resin, acrylic resin, vinyl resin, polyurethane, silicone, silicates and synthetic rubber.
7. The paint of any of claims 1-6, characterised in that the pigment is selected from metallic zinc, iron and aluminium, and slightly soluble salts and oxides thereof and of calcium, magnesium and ammonium.
8. The paint of any of claims 1-7, characterised in that the pigment has an anticorrosive effect .
9. The paint of any of claims 1-8, characterised in that the slightly soluble pigment is zinc oxide.
10. The use of a paint according to any of claims 1-9 for coating objects which are submerged in water.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NO952537A NO952537L (en) | 1995-06-23 | 1995-06-23 | Coarse paint |
NO952537 | 1995-06-23 | ||
PCT/NO1996/000153 WO1997000919A1 (en) | 1995-06-23 | 1996-06-21 | Antifouling paint |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0835290A1 true EP0835290A1 (en) | 1998-04-15 |
Family
ID=19898342
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP96922292A Withdrawn EP0835290A1 (en) | 1995-06-23 | 1996-06-21 | Antifouling paint |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0835290A1 (en) |
AU (1) | AU6321096A (en) |
NO (1) | NO952537L (en) |
WO (1) | WO1997000919A1 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100431725B1 (en) * | 2001-10-29 | 2004-05-17 | 한국수력원자력 주식회사 | Spacer grid with side welding support and flow mixing vane for nuclear reactor fuel assembly |
US6974847B1 (en) * | 2002-07-16 | 2005-12-13 | Matrix Engineering | Melt compounded fusion bonded marine anti-fouling coating |
ES2309593T3 (en) | 2003-10-16 | 2008-12-16 | THE PROCTER & GAMBLE COMPANY | WATERPROOF COMPOSITIONS THAT INCLUDE VESICLES THAT HAVE CERTAIN PERMEABILITY OF VESICULA. |
EP1986500A2 (en) * | 2006-02-16 | 2008-11-05 | Sachtleben Chemie GmbH | Biocidal composition |
DE102007042509A1 (en) * | 2007-09-07 | 2009-03-12 | Conrads, Mathias, Dipl.-Ing. | Coating material useful as cover coating for article surface, comprises resin based transparent bonding agent comprising components, and solid particles distributed in the bonding agent and having metal particles, pigments and/or fillers |
JP5814796B2 (en) | 2009-02-06 | 2015-11-17 | ヘンペル エイ/エス | Self-polishing paint composition based on enzyme |
SG11201402317UA (en) * | 2011-12-02 | 2014-09-26 | Akzo Nobel Coatings Int Bv | Waterborne antifouling coating composition |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1182376B (en) * | 1958-10-10 | 1964-11-26 | Akad Wissenschaften Ddr | Anti-fouling coating for objects that come into contact with water |
NL130862C (en) * | 1968-05-24 | |||
SE434517B (en) * | 1976-11-25 | 1984-07-30 | Extensor Ab | COMPOSITION WITH ANTI-ANTICIPATIVE PROPERTIES APPLICABLE SUCH AS SKEPPSBOTTENFERG, INCLUDING PARTICULAR POLYTETRAFLUORET AND USE THEREOF |
JPS5925843A (en) * | 1982-07-16 | 1984-02-09 | Osaka Soda Co Ltd | Seawater-resistant antifouling coating composition |
-
1995
- 1995-06-23 NO NO952537A patent/NO952537L/en unknown
-
1996
- 1996-06-21 EP EP96922292A patent/EP0835290A1/en not_active Withdrawn
- 1996-06-21 WO PCT/NO1996/000153 patent/WO1997000919A1/en not_active Application Discontinuation
- 1996-06-21 AU AU63210/96A patent/AU6321096A/en not_active Abandoned
Non-Patent Citations (1)
Title |
---|
See references of WO9700919A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO1997000919A1 (en) | 1997-01-09 |
NO952537L (en) | 1996-12-27 |
AU6321096A (en) | 1997-01-22 |
NO952537D0 (en) | 1995-06-23 |
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Legal Events
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