Compositions – Water-softening or purifying or scale-inhibiting agents – Plant or organic material containing
Reexamination Certificate
1999-06-18
2002-07-02
Anthony, Joseph D. (Department: 1714)
Compositions
Water-softening or purifying or scale-inhibiting agents
Plant or organic material containing
C252S181000, C106S287100, C106S287120, C106S287130, C427S387000, C428S447000, C428S907000
Reexamination Certificate
active
06413446
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to antifouling agents, to methods of producing and using them, and to antifouling coatings produced therefrom. Antifouling coatings serve for the protection of objects from fouling, particularly ship's hulls, screens, nets, buildings, canal installations, and signaling installations which come into contact with seawater or brackish water.
The occurrence of fouling is a serious problem, particularly for ships, since the frictional resistance is thereby increased and operating costs are considerably increased as a result of increased energy consumption and frequent dry dock maintenance. For this reason, antifouling coatings have long been used to prevent fouling by algae, barnacles, sedentaria, mussels, or other organisms.
A distinction can be made in principle between antifouling coatings that contain biocides and antifouling coatings that do not contain biocides.
Antifouling coatings that contain biocides constitute the state of the art. Organisms that result in fouling are killed off by the biocides. The usual antifouling biocides are organic tin compounds or copper, antimony, and bismuth compounds. The disadvantage of these biocides is their restricted environmental compatibility. Heavy metal biocides are particularly problematical, since these cause contamination of seawater and of the sea bed, particularly in the region of harbors.
Biocide-free antifouling coatings possess anti-adhesion properties intended to physically prevent the attachment of marine organisms. For example, the prior art comprises antifouling coatings based on liquid organosilicone, liquid paraffins, or fluorinated oils in combination with organopolysilicone polymers, particularly silicone elastomers (see U.S. Pat. No. 5,298,060 and DE-A 2,601,928). However, the effectiveness of antifouling coatings such as these is limited. A further disadvantage is their low mechanical loading capacity, which is frequently accompanied by unsatisfactory adhesion to anti-corrosion coatings, due to which the application of an additional primer coat may become necessary.
Copolymers of organic polymers and silicone polymers are also known from the prior art. U.S. Pat. No. 4,910,252 and WO 93 13179 describe biocide-free antifouling coatings which contain trialkoxysilane-group-containing polymers, preferably acrylates and linear siloxane polymers. EP 329 375 claims a coating composition of silicone polymers and polyurethane and/or polyurea. WO 98 38251 describes organic/inorganic hybrid materials produced from at least one organic polymer, inorganic (nano)particles and polyfunctional organosilanes.
The mode of action of the abovementioned antifouling coatings is based on the low surface tension of silicone-containing coatings and/or the more or less controlled release of slip additives which are intended to prevent the attachment of marine organisms.
The underlying object of the present invention is, therefore, to provide improved anti-fouling agents, which do not have the afore-mentioned disadvantages of known antifouling agents and the antifouling properties of which can be achieved even without biocides.
Surprisingly, it has now been found that this spectrum of requirements is fulfilled by antifouling agents that contain at least one multifunctional carbosilane and/or carbosiloxane (A), and which also optionally contain at least one additional alkoxysilane (B), a solvent-(C), catalyst (D), and/or inorganic nanoparticles (E), and optionally other additives (F).
The antifouling agents according to the invention cure at room temperature and are characterized by good adhesion to anti-corrosion coatings and by a high mechanical loading capacity. An additional primer coat is thus not necessary. The antifouling agents according to the invention exhibit a fouling-inhibiting effect and effectively protect objects from fouling, particularly ships' hulls, screens, nets, buildings, canal installations, and signaling installations that come into contact with seawater or brackish water.
SUMMARY OF THE INVENTION
The present invention therefore relates to antifouling agents comprising
(A) at least one multifunctional carbosilane and/or carbosiloxane of the general formula (I)
Q[(CH
2
)
m
SiR
1
n
X
(3−n)
]
p
(I)
and/or a partial condensation product thereof,
wherein
R
1
is a C
1
-C
18
alkyl and/or C
6
-C
20
aryl, wherein R
1
may represent radi-
cals which are identical or different within the molecule,
X
is OH, C
1
-C
4
alkoxy, C
6
-C
20
aryloxy, or C
1
-C
6
acyloxy, (prefer-
ably OH, methoxy, or ethoxy),
n
is 0 to 2,
m
is 2 to 6,
p
is an integer ≧2, and
Q
is either (i) a linear or cyclic silane or siloxane or (ii) an unsubstituted
hydrocarbon or a hydrocarbon in which at least one carbon atom is
substituted with at least one member of the group consisting of O, N,
S, and P,
(B) optionally, one or more alkoxysilanes,
(C) optionally, an organic solvent and/or water,
(D) optionally, a catalyst,
(E) optionally, inorganic nanoparticles, and
(F) optionally, other additives.
DETAILED DESCRIPTION OF THE INVENTION
Multifunctional carbosilanes (A) in the sense of the present invention are silanes of general formula (II)
R
2
4−p
Si[(CH
2
)
m
SiR
1
n
X′
(3−n)
]
p
(II)
or partial condensation products thereof,
wherein
p
is 4, 3, or 2 (preferably 4),
X′
is C
1
-C
4
alkoxy or C
6
-C
20
aryloxy (preferably methoxy or ethoxy),
R
2
denotes C
1
-C
18
alkyl and/or C
6
-C
20
aryl, and
m, n, and R
1
have the meanings given above.
In another embodiment of the invention, multifunctional carbosiloxanes (A) contain at least two components selected from monofunctional siloxane units M of general formula R
3
SiO
12
, difunctional siloxane units D of general formula R
2
SiO2/2, and/or trifunctional siloxane units T of general formula RSiO
3/2
, and optionally also contain tetrafunctional siloxane units Q of general formula SiO
4/2
and/or condensation products and/or partial condensation products thereof. These compounds may be substituted with at least one member of the group O, N, S, and P. In this context R denotes a C
1
-C
18
alkyl and/or C
6
-C
20
aryl, wherein R may represent radicals which are identical or different within the molecule.
The siloxanes according to the invention preferably have a (number average) molecular weight between 300 and 5000.
In one preferred embodiment, multifunctional carbosiloxanes (A) are compounds of formula (III)
or (partial) condensation products thereof, wherein a is 3 to 6 (preferably 4), and R
1
, X, m and n have the meanings given in formula (I).
Compounds that are particularly preferred for the antifouling agents according to the invention are those of formulas (IV) and/or (V)
or partial condensation products thereof.
The multifunctional carbosilanes and/or carbosiloxanes are preferably prepared by the method described in DE-A 1,960,3241 and DE 1,971 1650, namely by the hydrosilylation of the corresponding vinyl compounds with a chlorosilane and subsequent hydrolysis and/or alcoholysis.
However, multifunctional carbosilanes (A) may also be heterocyclic compounds, such as, for example, a compound of formula (VI)
This tris[3-(trimethoxysilyl)propyl]isocyanurate of formula (VI) is obtainable from the Witco company under the trade name Silquest® Y-11597.
Multifunctional carbosilanes (A) may also be the reaction products of what are preferably aliphatic polyols, such as pentaerythritol 2,2-bis(hydroxymethyl)-1,3-propanediol, with silanes of formula (VII)
ONC—(CH
2
)
m
SiR
1
n
X
(3−n)
(VII)
wherein R
1
, X, m, and n have the meanings given for formula (I), and/or reaction products of what are preferably aliphatic polyisocyanates, such as polyisocyanates based on hexamethylenediamine (“HDI”), with silanes of formula (VIII)
R
3
NH—(CH
2
)
m
SiR
1
n
X
(3−n)
(VIII)
wherein R
1
, X, m, and n have the meanings given in formula (I) and R
3
denotes a C
1
-C
4
alkyl radical.
The alkoxysilanes (B) are particularly preferably use
Käsler Karl-Heinz
Mager Michael
Mechtel Markus
Anthony Joseph D.
Bayer Aktiengesellschaft
Eyl Diderico van
Gil Joseph C.
Henderson Richard E. L.
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