Source: https://patents.justia.com/patent/4861670
Timestamp: 2020-02-23 12:13:57
Document Index: 246803806

Matched Legal Cases: ['arts 80', 'arts 4', 'arts 40', 'arts 3', 'arts 30', 'arts 40', 'arts 9']

US Patent for Marine foulant release coating Patent (Patent # 4,861,670 issued August 29, 1989) - Justia Patents Search
Justia Patents As Siloxane, Silicone Or SilaneUS Patent for Marine foulant release coating Patent (Patent # 4,861,670)
Marine foulant release coating
Dec 15, 1987 - General Electric
The most widely used poison for present day anti-fouling paints is cuprous oxide (CU.sub.2 O), while it must be noted that cupric oxide (CUO) is useless as an anti-fouling agent. Thus in utilizing cuprous oxide it is necessary to add an anti-oxidizing agent to the paint to prevent atmospheric oxidation to the inactive cupric form. Mercury compounds have also been used to a limited extent although they do not appear to be as effective as copper and are toxic to humans. Recently some tin compounds, notably tributyl tin oxide (TBTO) have been introduced and claimed to be highly effective (some 3 times more effective than copper). However, the cost is more than 10 times the cuprous compounds and the effectiveness drops off rather abruptly as opposed to the tapering effect of copper. Other inorganic compounds such as arsenious oxide, zinc oxide and nickel compounds have proven of little value though recent work with zinc oxide indicates that such is capable of reinforcing the longevity of life effectiveness of copper as an anti-foulant.
(CH.sub.2 .dbd.CH)R.sub.2 SiO--[R'.sub.2 SiO].sub.n --R.sub.2 Si(CH.dbd.CH.sub.2)
where R and R' are monovalent hydrocarbon radicals free of aliphatic unsaturation, with at least 50 mole percent of the R' groups being methyl and where n has a value sufficient to provide a viscosity of from about 2,000 to 750,000 centistokes at 25.degree. C., preferably from about 50,000 to 150,000, inclusive,
(2) from 20 to 50 parts of an organopolysiloxane copolymer comprising where (R").sub.3 SiO.sub.0.5 units and SiO.sub.4/2 units, where R" is a member selected from the class consisting of vinyl radicals and monovalent hydrocarbon radicals free of aliphatic unsaturation, where the ratio of (R").sub.3 SiO.sub.0.5 units to SiO.sub.4/2 units is from about 0.5:1 to 1:1, and where from about 2.5 to 10 mole percent of the silicon atoms contain silicon-bonded vinyl groups,
The compositions of the present invention are described in U.S. Pat. No. 3,436,366 to Modic, hereby incorporated by reference, and are prepared by mixing in a suitable fashion all of the components described above, plus any additional components such as will be described subsequently. Subsequent to mixing, the composition will cure to a silicone rubber, assuming a proper temperature is maintained. The compositions cure at temperatures which vary from room temperature to temperatures of the order of 100.degree. C. or higher, depending upon the particular amount of platinum catalyst present in the composition and depending upon the catalyst present in the composition and depending upon the time which is allowed for the cure. Likewise, the compositions can be prevented from curing by maintaining them at a reduced temperature, such as a temperature of 0.degree. C., in which case all of the components can be kept together for extended periods of time without curing. The compositions can vary from readily flowable liquids to slowly flowing liquids, depending upon the viscosity of the various components employed in the reaction mixture depending upon the amount of filler included in the reaction mixture. Regardless of the flow characteristics of the compositions of the present invention and the proportions of the various ingredients, the compositions cure to a hard, tough silicone elastomer upon maintaining the compositions at the curing temperature for he required amount of time. The compositions are translucent or opaque, depending upon the particular filler employed, and the color of the cured product is a function of the filler and any coloring agents added to the composition.
The organopolysiloxane copolymer which comprises component (2) of the compositions of this invention have been defined as including R" groups which can be vinyl or monovalent hydrocarbon radicals free of aliphatic unsaturation, with at least the stated proportion of the R" groups being vinyl. The R" groups which are not vinyl are of the same scope as the R and R' groups of formula (1) and like these groups, in the preferred embodiment of the invention, all of the monovalent hydrocarbon radicals free of aliphatic unsaturation are preferably methyl groups. The vinyl groups can be present either as a portion of the (R").sub.3 SiO.sub.0.5 groups as mentioned or of (R").sub.2 SiO groups or can be present in both groups.
In general, the various types of siloxane units in copolymer component (2) are selected so that the ratio of the (R").sub.3 SiO.sub.0.5 units to the SiO.sub.4/2 units is between 0.5:1 and 1:1. The (R").sub.2 SiO units may or may not be present, but are preferably present in an amount equal to from about 0.01:1 to about 0.2:1 based on SiO.sub.4/2 in the copolymer. Regardless of where the silicon-bonded vinyl groups are located in the copolymer, the silicon-bonded vinyl groups should be present in an amount equal to from about 2.5 to 10.0 mole percent of copolymer component (2).
The platinum catalyt component (4) employed in the present invention includes all of the well known platinum catalysts which are effective for catalyzing the reaction between silicon-bonded hydrogen groups and silicon-bonded vinyl groups. These materials include the various finely divided elemental platinum catalysts, such as those showin in U.S. Pat. No. 2,970,150--Bailey, the chloroplatinic acid catalyst described in U.S. Pat. No. 2,823,218--Speier, the platinum hyrocarbon complexes shown in U.S. Pat. Nos. 3,159,601--Ashby, and 3,159,662--Ashby, as well as the platinum alcoholate catalysts which are described in U.S. Pat. No. 3,220,972--Lamoreaux. Regardless of the type of platinum catalyst employed, the catalyst is used in an amount sufficient to provide from about 10.sup.-3 t 10.sup.-6 grams atoms of platinum per moleof silicon-bonded vinyl groups in the composition.
One illustration of a specific organohydrogenpolysiloxane compound which can be employed in the practice of the present invention is 1,3,5,7-tetramethylcyclotetrasiloxane, which contains one silicon-bonded methyl group and one silicon-bonded hydrogen atom per silicone atom. Another illustrative material is a dimethylhydrogen chain-stopped dimethylpolysiloxane containing from 2 to 3 silicon atoms in the molecule. A further type of composition is one which comprises a copolymer of dimethylsiloxane units, methylhydrogensiloxane units, and trimethylsiloxane units and which contains from 2 to 5 or 10 or more silicon atoms per molecule. A still further useful type of compound is the compound containing three dimethylhydrogensiloxane units and one monomethylsiloxane unit per molecule. Another useful material is the low viscosity fluid composed of dimethylhydrogensiloxane units and SiO.sub.4/2 units in the ratio of 2 moles of the former to one mole of the latter. In addition to containing silicon-bonded methyl groups as illustrated in the specific compounds mentioned above, these organohydrogenpolysiloxanes can also contain a variety of other organic groups, even though the preferred materials are those in which all of the R" groups of formula (2) are methyl. No disadvantage is found in substituting a minor portion of the methyl groups with phenyl groups.
When the two-package system is employed, the two components are merely mixed in suitable fashion at the point of use and the mixture is maintained at the curing temperature until curing has been completed. Generally, complete cure can be obtained at times which vary from 24 hours at room temperature to 10 to 20 minutes at a temperature of about 100.degree. C. The rate of cure is a function of both the concentration of platinum catalyst and the temperature of cure.
Coating  Description
A        Mixture of 80.5 parts 80,000 centipoise vinyl
terminated polydimethylsiloxane, 27 parts
silicone resin having by number 0.6
(CH.sub.3).sub.3 SiO.sub.1/2 /0.085
CH.sub.3 (CH.sub.2 .dbd.CH)SiO.sub.2/2 /1 SiO.sub.4/2, 50 parts
extending filler, 20 ppm of Pt based on linear
vinyl polymer in form of Karstedt complex, and
6.75 parts silicone resin having by number 1.33
H(CH.sub.3).sub.2 SiO.sub.1/2 /SiO.sub.4/2.
B        Mixture of 100 parts 4,000 centipoise silanol
terminated polydimethylsiloxane, 62.5 parts
extending filler, 3 parts 40% condensed
ethylorthosilicate, and 1,000 ppm water.
C        Mixture of 100 parts 3,000 centipoise silanol
terminated polydimethylsiloxane, 40 parts
ethylorthosilicate, and 750 ppm water.
D        Mixture of 93 parts 30,000 centipoise silanol/
t-butoxy stopped polydimethylsiloxane, 24 parts
reinforcing filler, 3 parts extending filler,
28.5 parts extending polydimethylsiloxane, 1.6
parts silanol terminated dimethylsiloxane fluid,
2 parts 40% condensed ethylorthosilicate, 0.5
parts tin catalyst and 0.5 parts pigment.
E        Mixture of 100 parts silanol terminated
polydimethylsiloxane, 3,500 centipoise, 17 parts
reinforcing filler, 11 parts liquid resin having
R.sub.3 SiO.sub.1/2  units, R.sub.2 SiO.sub.2/2 units and
RSiO.sub.3/2 units, and 7 parts of catalyst mixture
containing alkylsilanes, silicates and tin
F        Mixture of 66 parts methyldimethoxy terminated
polydimethylsiloxane, 10 parts reinforcing
filler, 18 parts silanol terminated
dimethylsiloxane fluid, 2 parts methanol
scavenger, 1.4 parts trimethoxysilane, and 0.1
part tin catalyst.
G        Mixture of 93 parts 9,000 centipoise silanol
terminated polydimethylsiloxane, 129 parts
extending filler, 61 parts hydrocarbon solvent, 2
parts titanium dioxide, 2 parts alkyl silane and
silicate, 0.2 parts tin catalyst, 4 parts mineral
H        Aquatek coating, obtained commercially and
advertised as anti-foulant.
I        Miracol 253 coating, obtained commercially and
J        Micron 33 coating, obtained commercially and
Coating Utilized  Foul Release
A       Yes       Good-excellent
Excellent.sup.1
B       Yes       Excellent   Excellent
C       Yes       Excellent   Good
D       Yes       Good        Good
E       No        Fair        Fair
F       No        Fair        Fair
G       No        Poor        Poor
H       No        Good        Very Poor.sup.2
I       No        Fair        Very Poor.sup.2
J       No        Good        Very Poor.sup.2
.sup.1 Superior in adhesion and corrosion break through as compared to
.sup.2 Over 1/2 of surface lost during exposure
1. A ship's hull normally immersed in sea water and coated with an outermost coating of a curable silicone rubber composition comprising:
where R and R' are monovalent hydrocarbon radicals free of aliphatic unsaturation, with at least 50 mole percent of the R' groups being methyl and where n has a value sufficient to provide a viscosity of from about 2,500 to 750,000 centistokes at 25.degree. C.,
(2) from 20 to 50 parts of an organopolysiloxane copolymer comprising (R").sub.3 SiO.sub.0.5 units and SiO.sub.4/2 units, where R" is a member selected from the class consisting of vinyl radicals and monovalent hydrocarbon radicals free of aliphatic unsaturation, where the ratio of (R").sub.3 SiO.sub.0.5 units to SiO.sub.4/2 units is from about 0.5:1 to 1:1, and where from about 2.5 to 10 mole percent of the silicon atoms contain silicon-bonded vinyl groups,
2. The hull and silicone coating of claim 1 wherein said coating has a thickness of from 0.5 to 40 mil.
5. The hull and silicone coating of claim 1 wherein the viscosity of component (1) is from about 2,500 to 150,000 centipoise at 25.degree. C.
7. A method for reducing foul on ships comprising the step of coating the ship's hull with a outermost coating of a curable silicone rubber composition comprising:
4080190 March 21, 1978 Law
4298543 November 3, 1981 Law et al.
Patent number: 4861670
Inventors: Warren R. Lampe (Charlton, NY), Annette A. Moore (Gansevort, NY), Kathleen R. Hartley (Troy, NY)
Application Number: 7/132,379
Current U.S. Class: As Siloxane, Silicone Or Silane (428/447); 106/1505; Of Metal (428/457); Next To Metal (428/450)
International Classification: A01N 900;