WO2016090468A1

WO2016090468A1 - Coating compositions, method of preparation thereof and uses thereof

Info

Publication number: WO2016090468A1
Application number: PCT/CA2015/051260
Authority: WO
Inventors: Michel Couturier
Original assignee: Bio-Innox Anticorrosion Inc.
Priority date: 2014-12-08
Filing date: 2015-12-02
Publication date: 2016-06-16

Abstract

The present disclosure relates to a coating composition comprising an epoxy resin; an amino-functional silicone resin; methoxy-functional silicone resin; and an end functional polydimethylsiloxane; a method for preparing said composition by crosslinking the three resins in the presence of an end-functional polydimethylsiloxane and a method of use thereof.

Description

COATING COMPOSITIONS, METHOD OF PREPARATION THEREOF AND USES THEREOF

BACKGROUND OF THE DISCLOSURE

Ice accretion on various structures and vehicles exposed to the Nordic elements is problematic and can lead to catastrophic failures. In particular, windmill blades will often build-up ice that results in a lower efficiency energy output. To address this problematic, some windmill manufacturers have designed active de-icing systems where electricity generated heat is deployed within the blades. In this context, the energy required for this de-icing procedure is compounded by the loss of energy of the non-operational windmill.

In view of the energy losses, the identification of a coating to which ice loosely adheres to has been the subject of intensive efforts over the past decades. This so-called passive approach requires no heating elements, and vibrations, wind, centrifugal force etc. shed the ice. Various oils and greases have been tested and found efficient, but sacrificial in that the slippery agent leaches after each successive de-icing and the desired effect is non-lasting. Insofar, addition cured and condensation (moisture) cured silicones comprising silicon oil or reactive derivatives thereof have exhibited reduced ice adhesion, but are rather soft and not abrasion resistant. Heat cured silicone has both ice adherence reduction and abrasion resistance, but the cure mode is rather impractical. A room temperature curable coating under the trademark Wearlon, a water- based amide type epoxy, comprised of a fatty acid derived polyethylenepolyamine, a bisphenol- A derived epoxy resin, a linear end functional polydiorganosiloxane and a surfactant is not as efficient at shedding ice as addition cured silicone resins. Also, certain matrices containing 20% of a liquid freezing point depressant (magnesium chloride, propylene glycol 1 : 1) have been reported, however by virtue of its leachable nature in the mode of action, the freezing point depressant is sacrificial. The curing of certain coatings is dependant on the water from atmospheric moisture, and the level of humidity determines the curing rate, which may cause drawbacks in an open environment.

Thus, it is clear that there remains a need for ice shedding coatings. SUMMARY OF THE DISCLOSURE

In one aspect, there is provided a coating composition comprising: i) an epoxy resin;

ii) an amino-functional silicone resin;

iii) a methoxy-functional silicone resin;

iv) and an end functional polydimethylsiloxane.

In one aspect, there is provided a method for preparing the coating composition as described herein, comprising crosslinking an epoxy resin with an amino-functional silicone resin and a methoxy-functional silicone resin in the presence of an end functional polydimethylsiloxane.

In one aspect, there is provided articles surface-coated with composition as defined herein to substantially reduce or eliminate ice accretion on said surface.

In one aspect, there is provided a method for reducing ice-adhesion to a substrate comprising preparing the ice coating composition as described herein, and applying said coating composition to said substrate prior to the curing of said composition.

DETAILED DESCRIPTION OF THE DISCLOSURE

In one embodiment, there is provided a coating composition resulting from a blend comprising a), b) and c) wherein:

a) is a blend of i) an epoxy resin and iv) and an end functional polydimethylsiloxane;

b) is a blend of ii) an amino-functional silicone resin and iii) a methoxy-functional silicone resin; c) is at least one catalyst.

In one embodiment, there is provided an ice shedding coating composition resulting from a blend comprising a), b) and c) wherein: a) is a blend of i) an epoxy resin and iv) and an end functional polydimethylsiloxane; b) is a blend of ii) an amino-functional silicone resin and iii) a methoxy-functional silicone resin; c) is at least one catalyst and optionally additional agents.

b) is a blend of ii) an amino-functional silicone resin and iii) a methoxy-functional silicone resin; c) is at least one catalyst in a), b) or both.

b) is a blend of ii) an amino-functional silicone resin and iii) a methoxy-functional silicone resin; c) is at least one catalyst in a), b) or both and optionally additional agents.

In one embodiment, there is provided a coating composition resulting from a blend comprising a), b), c) and optionally d) wherein:

b) is a blend of ii) an amino-functional silicone resin and iii) a methoxy-functional silicone resin; c) is at least one catalyst in a), b) or both;

d) is an hindered amine light stabilizer (HALS).

In one embodiment, there is provided a coating composition resulting from a blend comprising a) and b) wherein:

a) is a blend of i) an epoxy resin, iv) an end functional polydimethylsiloxane and optionally a titanium catalyst; and

b) is a blend of ii) an amino-functional silicone resin, iii) a methoxy-functional silicone resin and optionally an organotin catalyst. In one embodiment, there is provided a coating composition resulting from a blend comprising a) and b) wherein:

a) is a blend of i) an epoxy resin, iv) an end functional polydimethylsiloxane and a titanium catalyst; and

b) is a blend of ii) an amino-functional silicone resin, iii) a methoxy -functional silicone resin and an organotin catalyst ;

and optionally additional agents.

In one embodiment, there is provided a coating composition comprising:

a mixed epoxy-siloxane resin resulting from a blend consisting of a), b), and c)

wherein a) is a blend of i) an epoxy resin and iv) an end functional polydimethylsiloxane; b) is a blend of ii) an amino-functional silicone resin and iii) a methoxy-functional silicone resin; c) at least one catalyst;

and the composition optionally comprising d) an hindered amine light stabilizer.

In one embodiment, there is provided a coating composition comprising:

a mixed epoxy-siloxane resin resulting from a blend consisting of a) and b)

wherein a) is a blend of i) an epoxy resin iv) an end functional polydimethylsiloxane and a titanium catalyst; b) is a blend of ii) an amino-functional silicone resin, iii) a methoxy-functional silicone resin and an organotin catalyst;

and the composition optionally comprising d) and optionally additional agents.

In one embodiment, there is provided a coating composition comprising:

a mixed epoxy-siloxane resin resulting from a blend consisting of a) and b)

In one embodiment, there is provided a method for preparing a coating composition comprising

1) blending i) an epoxy resin, ii) an amino-functional silicone resin, iii) a methoxy-functional silicone resin and iv) an end functional polydimethylsiloxane; and

2) blending the mixture resulting from 1) with one or more catalyst.

1) blending a first composition comprising i) an epoxy resin together with iv) an end functional polydimethylsiloxane;

blending a second composition comprising ii) an amino-functional silicone resin together with iii) a methoxy-functional silicone resin; and

2) blending the first and second compositions resulting from 1) with one or more catalyst.

1) blending a first composition comprising i) an epoxy resin together with iv) an end functional polydimethylsiloxane and one or more catalyst;

blending a second composition comprising ii) an amino-functional silicone resin together with iii) a methoxy-functional silicone resin and one or more catalyst; and

2) blending the first and second compositions resulting from 1) .

2) blending the first and second compositions resulting from 1) and optionally d) an hindered amine light stabilizer.

2) blending the first and second compositions resulting from 1) and optionally additional agents. In one embodiment, there is provided a method for preparing a coating composition comprising:

1) preparing a mixed epoxy-siloxane resin resulting from a blend consisting of i) an epoxy resin iv) an end functional polydimethylsiloxane, ii) an amino-functional silicone resin, iii) a methoxy -functional silicone resin and one or more catalyst;

2) blending 1) above and optionally additional agents.

In one embodiment, there is provided a method for preparing a coating composition comprising:

1) preparing a mixed epoxy-siloxane resin resulting from a blend consisting of a), b) and c) wherein a) is a blend of i) an epoxy resin iv) an end functional polydimethylsiloxane; b) is a blend of ii) an amino-functional silicone resin, iii) a methoxy -functional silicone resin; c) and one or more catalyst in a), b) or both;

2) blending 1) above and optionally additional agents.

1) preparing a mixed epoxy-siloxane resin resulting from a blend consisting of a) and b) wherein a) is a blend of i) an epoxy resin iv) an end functional polydimethylsiloxane and one or more catalyst; b) is a blend of ii) an amino-functional silicone resin, iii) a methoxy -functional silicone resin and one or more catalyst;

2) blending 1) above and optionally additional agents.

1) preparing a mixed epoxy-siloxane resin resulting from a blend consisting of a) and b) wherein a) is a blend of i) an epoxy resin iv) an end functional polydimethylsiloxane and a titanium catalyst; b) is a blend of ii) an amino-functional silicone resin, iii) a methoxy -functional silicone resin and an organotin catalyst;

2) blending 1) above and an hindered amine light stabilizer.

In one embodiment, said catalyst of any blend of i) and iv) described herein is a titanium catalyst and said catalyst of any blend of ii) and iii) described herein is an organotin catalyst. In one embodiment, said catalyst of any blend of i) and iv) described herein is diisopropoxy titanium bis(acetylacetonate).

In one embodiment, said catalyst of any blend of ii) and iii) described herein is dibutyltin dilaurate.

In one embodiment, said catalyst of any blend of i) and iv) described herein is diisopropoxy titanium bis(acetylacetonate) and said catalyst of any blend of ii) and iii) described herein is dibutyltin dilaurate.

In one embodiment, said catalyst of any blend of i), ii), iii) and iv) and optionally any additional agent is diisopropoxy titanium bis(acetylacetonate).

The coating composition herein may be characterized as an ice shedding coating composition.

The present disclosure provides new epoxy-polysiloxane polymer coating compositions that render surfaces on which they are applied to slippery such that ice accretion and accumulation is diminished. The coatings of the present disclosure are of the thermoset plastic type. Thermoset plastics contain polymers that cross-link together during the curing process to form an irreversible chemical bond.

Suitable epoxy resins useful in forming coating embodiments of the present disclosure may include non-aromatic epoxy resins comprising more than one epoxy group per molecule as glycidyl ethers. Preferably, the non-aromatic epoxide resin has two 1,2 epoxide group per molecule. Preferably the epoxide has an epoxide equivalent weight of 100 to 5,000.

A preferred epoxy resins includes hydrogenated bisphenol A-type epoxy resin such as Eponex 1510 and 1513 from Hexion, Epalloy 5000 and 5001 from Emerald Performance Materials, YDH 3000 from Epotec and Denacol EX-252 from ChemteX.

The epoxide equivalent weight of preferred resins is in the range of from about 100 to 2000. Typically, the epoxide equivalent weight is 100 to about 500. According to various embodiments, the icephobic coating composition may comprise 15% to 50% by weight of the epoxide resin, relative to the total weight of the solids of the composition and in other embodiments from 20% to 30% by weight of epoxy resin. According to one embodiment the coating composition may comprise about 25% by weight of epoxide resin.

The epoxy resin may further comprise epoxy functional reactive modifiers such as TTA21 from Phibro and CER 4221 from Achiwell, Epodyl 757 from Air Products, Heloxy 107 from Hexion, Erisys GE-22 from Emerald Performance Materials. Epoxy functional reactive modifiers propylene glycol diepoxide resins such as D.E.R 732 from Dow and triglycidyl ether of castor oil such as Erisys GE-35 from Emerald Performance Materials may be used in the formulation of an icephobic coating. Epoxypropoxypropyl terminated polydimethylsiloxanes (DMS-09 and 11), (epoxypropoxypropylmethylsiloxane) - (dimethylsiloxane) Copolymers (EMS-622), (epoxypropoxypropyl)dimethoxysilyl terminated polydimethylsiloxanes (DMS-EX21), (epoxycyclohexylethylmethylsiloxane) - dimethylsiloxane copolymers (ECMS-series), all from Gelest, are examples of epoxy functional polydimethylsiloxanes that may be comprised in the coating formulation.

A polysiloxane is a silicon containing compound containing repeating (Si-O) units. A silane is a silicon-containing compound, which does not contain repeating (Si-O) units. Silicone resins are polymers containing siloxane units independently selected from (R3S1O1/2), (R₂Si0₂/₂), (RSi0₃/₂), or (Si0_4/2) siloxy units, where R may be any monovalent organic group. The siloxy units are commonly referred to as M, D, T, and Q units respectively. These siloxy units can be combined in various manners to form cyclic, linear, or branched structures. A silicone resin contains at least one T unit and/or at least one Q unit. Preferably a silicone resin contains two or more T units and/or Q units.

According to specific embodiments, a suitable amino functional polysiloxane resin comprise the units: (R₃SiOi/₂)_w (1); (R₂Si0_2/2)_x (2); (RSi0_3/2)_y (3) and (Si0_4/2)_z (4) wherein w+x+y+z=l, R is selected from the group consisting of an alkyl group having up to four carbon atoms, an aryl group, an aminofunctional hydrocarbon group having up to four carbon atoms or alkoxy groups having up to four carbon atoms, w has a value of less than 0.4, x has a value of greater than 0.15, y has a value greater than zero to 0.7, z has a value of less than 0.2, at least 10 mole percent of silicon atoms in unit (2) contain aminofunctional hydrocarbon groups, with an amine equivalent weight ranging from about 150 to about 350 g/NH.

In preferred embodiments, z = 0, the R groups are Methyl in (1), the R groups are Methyl and Phenyl, or Methyl and 3-Aminopropyl in (2), the R group is Phenyl or 3-Aminopropyl in (3) with an high amine content of about 250 g/NH and less than 2% of methoxy radicals. According to various embodiments, the icephobic coating composition may comprise 20% to 60% by weight of the amine-functional silicone resin, relative to the total weight of the solids of the composition and in other embodiments from 25% to 50% by weight of amine-functional silicone resin. According to one embodiment the coating composition may comprise about 40% by weight of amine-functional silicone resin. Examples of such resin include DC 3055 from Dow Corning, and Silres HP 2000 from Wacker.

According to an embodiment, suitable methoxy-functional silicone resins comprise the units: (R'₃Si0_1/2V (n (R'₂Si0_2/2 (2J, (R' Si0_3/2V and (Si0₄/₂)_z ^< (4') wherein w'+x'+y'+z'=l, R' is selected from the group consisting of an alkyl group having up to four carbon atoms, an aryl group or an alkoxy groups having up to four carbon atoms and the polysiloxane ingredient have a molecular weight in the range of from about 400 to about 10,000.

In preferred embodiments, the R' groups are Methoxy, Methyl and Phenyl, with a methoxy content of about 15% and a molecular weight in the range of from about 1200 to about 1900;

According to various embodiments, the coating composition may comprise 15% to 50% by weight of the methoxy-functional silicone resin, relative to the total weight of the solids of the composition, and in other embodiments from 20% to 30% by weight of methoxy-functional silicone resin. According to one embodiment the coating composition may comprise about 25% by weight of methoxy-functional silicone resin.

Preferred methoxy-functional silicone resins include, Silres IC 232, Silres SY 231, Silres IC 368, Silres IC 678 all from Wacker, and DC 3037, DC 3074 from Dow Corning. Hydroxyl-functional silicone resins such as Silres SY 300 and Silres IC 836 may be used as replacement of methoxy- functional silicone resins. According to various embodiments, the coating composition comprises end-functional polydimethylsiloxanes having the formula:

wherein R₅ is an alkyl up to four carbon atoms, a hydroxyl group, a 3-aminopropyl, a 3- hydroxypropyl or a 3-(hydroxyethoxy)propyl; P6 is a hydroxyl group, a 3-aminopropyl, a 3- hydroxypropyl or a 3 -(hydroxy ethoxy)propyl and where n is selected so that the molecular weight for the polysiloxane is 400 to 110,000.

Preferred end functional polysiloxanes includes mono and/or bis silanol-terminated polydimethylsiloxanes (i,e. one of R5 or R6 is -OH or both of R5 and R6 are -OH) with a viscosity of about 1000 cSt.

According to various embodiments, the viscosity of the end functional polydimethylsiloxane is about 15 cPs to 50,000 cPs, and in other embodiments from 100 cPs to 10000 cPs. According to one embodiment, the viscosity of the end functional polydimethylsiloxane is about 1000 cPs. According to various embodiments, the coating composition may comprise 1% to 20% by weight of the end functional polydimethylsiloxane, relative to the total weight of the solids of the composition, and in other embodiments from 5% to 15% by weight of end functional polydimethylsiloxane. According to one embodiment the coating composition may comprise about 8%) by weight of end functional polydimethylsiloxane.

Examples of silanol-terminated polydimethylsiloxane include DMS-S, PDS and FMS series from Gelest and Andisil OH and MOH series from Speciality Silicones. Carbinol-terminated such as DMS-C, DBE-C, DBP-C, CMS, MCR-C and MCS-C series from Gelest may also be suitable end-functional polysiloxanes.

In certain embodiments, catalysts may be added to accelerate curing rate of the composition.

Catalysts may be one or more organometallic derivatives of titanium, tin, bismuth, zinc, iron, lead, manganese, zirconium or cobalt. It is understood that the use of "catalyst" herein refers to a curing catalyst suitable for curing the composition, preferably in absence of added water. Preferably the catalyst is suitable to cure the composition within less than about 24 hours, preferably less than 12 hours or preferably less than 8 hours.

In one embodiment, the catalyst that can be used include dimethoxy titanium bis(ethylacetoacetate), dimethoxy titanium bis(acetylacetonate), diethoxy titanium bis(ethylacetoacetate), diethoxy titanium bis(acetylacetonate), diisopropoxy titanium bis(ethylacetoacetate), diisopropoxy titanium bis(methylacetoacetate), diisopropoxy titanium bis(t-butylacetoacetate), diisopropoxy titanium bis(acetylacetonate), di(n-butoxy) titanium bis(ethylacetoacetate), di(n-butoxy) titanium bis(acetylacetonate), diisobutoxy titanium bis(ethylacetoacetate), diisobutoxy titanium bis(acetylacetonate), di(t-butoxy) titanium bis(ethylacetoacetate), di(t-butoxy) titanium bis(acetylacetonate).

It is preferred to use the following titanium catalyst, because they are commercially obtainable: diethoxy titanium bis(ethylacetoacetate), diethoxy titanium bis(acetylacetonate), diisopropoxy titanium bis(ethylacetoacetate), diisopropoxy titanium bis(acetylacetonate), dibutoxy titanium bis(ethylacetoacetate), and dibutoxy titanium bis(acetylacetonate).

Diisopropoxy titanium bis(acetylacetonate) is particularly preferred.

In preferred embodiments, the catalysts are dibutyltin dilaureate commercially available as DABCO T-12 from Air Products together with diisopropoxy titanium bis(acetylacetonate) .

In various embodiments, the coating composition may comprise additional agents such as solvents, adhesion promoters, stabilizing agents, reinforcers, fillers, corrosion inhibitors, pigments, plasticisers, suspending agents, thixotropic agents, diluents, reactive diluents, UV light stabilizers, HALS, surfactant, or mixture thereof. One of ordinary skill in the resin coating composition art would understand that other common components may be incorporated into the composition within the scope of the various embodiments described herein.

The coating composition herein is free of added water. Stated differently, although water may be present in a trace amount in the reagents or may be in the present of atmospheric humidity, no additional water is added to the composition. The coating composition herein may therefore be qualified as substantially free of water.

In one embodiment, the substrate is an epoxy or an unsaturated polyester type gelcoat, aluminum or steel.

In one embodiment, the method for reducing ice-adhesion to a substrate as defined herein is for reducing ice-adhesion on vanes (or sails or blades) of windmills, above water line of ship vessels and oilrigs, bridges, power line structures, environmental control system (ECS) condensers and aircraft fuselages.

In one embodiment of any of the composition or methods herein,

- said epoxy resin i) is non-aromatic epoxy resins comprising more than one epoxy group per molecule

- said amino-functional silicone resin ii) is comprising the units: (R3SiOi ₂)_w (1); (R₂Si0₂/₂)_x (2); (RSi0_3/2)_y (3) and (Si0_4/2)_z (4);

wherein w+x+y+z=l, R is selected from the group consisting of an alkyl group having up to four carbon atoms, an aryl group, an aminofunctional hydrocarbon group having up to four carbon atoms or alkoxy groups having up to four carbon atoms, w has a value of less than 0.4, x has a value of greater than 0.15, y has a value greater than zero to 0.7, z has a value of less than 0.2, at least 10 mole percent of silicon atoms in unit (2) contain aminofunctional hydrocarbon groups, with an amine equivalent weight ranging from about 150 to about 350 g/NH

- said methoxy-functional silicone resin iii) is comprising the units: (R'₃SiOi/₂)_W' (7');

(R'₂Si0_2/2)_x> (2'); (R' Si0_3/2)_y> (·?') and (Si0_4/2)_z> (¥');

wherein w'+x'+y'+z'=l, R' is selected from the group consisting of an alkyl group having up to four carbon atoms, an aryl group or an alkoxy groups having up to four carbon atoms;

- said end functional polydimethylsiloxane iv) is having the formula:

wherein R₅ is an alkyl up to four carbon atoms, a hydroxyl group, a 3-aminopropyl, a 3- hydroxypropyl or a 3-(hydroxyethoxy)propyl; R6 is a hydroxyl group, a 3-aminopropyl, a 3- hydroxypropyl or a 3 -(hydroxy ethoxy)propyl and where n is selected so that the molecular weight for the polysiloxane is 400 to 110,000; and the viscosity of the end functional

polydimethylsiloxane is about 15 cPs to 50,000 cPs; and

- said catalyst is one or more organometallic derivatives of titanium, tin, bismuth, zinc, iron, lead, manganese, zirconium or cobalt.

In one embodiment of any of the composition or methods herein,

- said epoxy resin i) non-aromatic epoxide resin having two 1,2 epoxide groups per molecule

- said amino-functional silicone resin ii) is comprising the units: (R₃SiOi/₂)w (1); (R₂Si0₂/₂)_x (2); (RSi0_3/2)_y (3) and (Si0₄/₂)_z (4);

wherein w+x+y+z=l, R groups are Methyl in (1), the R groups are Methyl and Phenyl, or Methyl and 3-Aminopropyl in (2), the R group is Phenyl or 3-Aminopropyl in (3); w has a value of less than 0.4, x has a value of greater than 0.15, y has a value greater than zero to 0.7, z= 0; at least 10 mole percent of silicon atoms in unit (2) contain aminofunctional hydrocarbon groups and said amino-functional silicone resin ii) having an amine content of about 250 g/NH and less than 2% of methoxy radicals;- said methoxy-functional silicone resin iii) is comprising the units: (R'₃SiOi/₂)_w ^> CO; (R'2Si0_2/2)_x ^> (2'); (R' Si0_3/2)_y ^> (·?') and (Si0_4/2)_z ^> (¥');

wherein w'+x'+y'+z'=l, R' is selected from the group consisting of an alkyl group having up to four carbon atoms, an aryl group or an alkoxy groups having up to four carbon atoms and have a molecular weight in the range of from about 400 to about 10,000;

- said end functional polydimethylsiloxane iv) is having the formula:

wherein R₅ is an alkyl up to four carbon atoms, a hydroxyl group, a 3-aminopropyl, a 3- hydroxypropyl or a 3 -(hydroxy ethoxy)propyl and R₆ is a hydroxyl group, or alternatively both R₅ and R₆ are -OH and where n is selected so that the molecular weight for the polysiloxane is 400 to 110,000; and the viscosity of the end functional polydimethylsiloxane is about 15 cPs to 50,000 cPs;

said catalyst of a blend of i) and iv) is a titanium catalyst and said catalyst of a blend of ii) and iii) is organotin catalyst.

In one embodiment of any the composition or methods herein,

- said epoxy resin i) non-aromatic epoxide resin having two 1,2 epoxide groups per molecule an epoxide equivalent weight of 100 to 5,000

- said amino-functional silicone resin ii) is comprising the units: (R3SiOi ₂)_w (1); (R₂Si0₂/₂)_x (2); (RSi0_{3 2})_y (3) and (Si0_{4 2})_z (4);

wherein w+x+y+z=l, R groups are Methyl in (1), the R groups are Methyl and Phenyl, or Methyl and 3-Aminopropyl in (2), the R group is Phenyl or 3-Aminopropyl in (3); w has a value of less than 0.4, x has a value of greater than 0.15, y has a value greater than zero to 0.7, z= 0; at least 10 mole percent of silicon atoms in unit (2) contain aminofunctional hydrocarbon groups and said amino-functional silicone resin ii) having an amine content of about 250 g/NH and less than 2% of methoxy radicals;

(R'₂Si0_2/2)_x> (2'); (R' Si0_3/2)_y> (·?') and (Si0_4/2)_z> (¥');

wherein w'+x'+y'+z'=l, R' groups are Methoxy, Methyl and Phenyl, with a methoxy content of about 15% and a molecular weight in the range of from about 1200 to about 1900;

- said end functional polydimethylsiloxane iv) is having the formula:

wherein both R₅ and R₆ are -OH and where n is selected so that the molecular weight for the polysiloxane is about 26,000; and the viscosity of the end functional polydimethylsiloxane is about 1000 cPs; and

said catalyst is a tin or an organotin catalyst.

In one embodiment of any of the composition or methods herein,

- said epoxy resin i) non-aromatic epoxide resin having two 1,2 epoxide groups per molecule an epoxide equivalent weight of 100 to about 500

(R'₂Si0_2/2)_x> (2'); (R' Si0_3/2)_y> (·?') and (Si0_4/2)_z> (¥');

wherein w'+x'+y'+z'=l, R' groups are Methoxy, Methyl and Phenyl, with a methoxy content of about 15% and a molecular weight in the range of from about 1200 to about 1900

- said end functional polydimethylsiloxane iv) is having the formula:

said catalyst said catalyst of a blend of i) and iv) is a titanium catalyst and said catalyst of a blend of ii) and iii) is organotin catalyst.

In one embodiment of any of the composition or methods herein,

- said epoxy resin i) hydrogenated bisphenol A-type epoxy resin having an epoxide equivalent weight is 100 to about 500;

(R'₂Si0_2/2V (2J, (R' Si0_3/2V and (Si0_4/2)_z ^> (¥');

- said end functional polydimethylsiloxane iv) is having the formula:

In one embodiment of any of the composition or methods herein,

- said amino-functional silicone resin ii) is comprising the units: (R₃SiOi/₂)w (1); (R₂Si0₂/₂)_x (2); (RSi0_3/2)_y (3) and (Si0₄/₂)z (4);

(R'₂Si0_2/2V (2J, (R' Si0_3/2V and (Si0_4/2)_z ^> (¥');

- said end functional polydimethylsiloxane iv) is having the formula:

said catalyst of a blend of i) and iv) is diisopropoxy titanium bis(acetylacetonate) and said catalyst of a blend of ii) and iii) is dibutyltin dilaurate.

In one embodiment of the composition or methods herein, said composition is comprising: 15% to 50%) by weight of the epoxide resin, relative to the total weight of the solids of the composition of said epoxy resin i);

20%) to 55%o by weight of the amine-functional silicone resin ii), relative to the total weight of the solids of the composition;

15%) to 50%o by weight of the methoxy-functional silicone resin iii) relative to the total weight of the solids of the composition;

1%) to 20%) by weight of the end functional polydimethylsiloxane iv), relative to the total weight of the solids of the composition, the total %> of all components including said catalyst and optional agents not being greater than 100%>.

In one embodiment of the composition or methods herein, said composition is comprising: 20%o to 30%) by weight of the epoxide resin, relative to the total weight of the solids of the composition of said epoxy resin i);

25%o to 50%) by weight of the amine-functional silicone resin ii), relative to the total weight of the solids of the composition;

20%o to30%> by weight of the methoxy-functional silicone resin iii) relative to the total weight of the solids of the composition;

5%o to 15%o by weight of the end functional polydimethylsiloxane iv), relative to the total weight of the solids of the composition, the total %> of all components including said catalyst and optional agents not being greater than 100%.

In one embodiment of the composition or methods herein, said composition is comprising:

about 25% by weight of the epoxide resin, relative to the total weight of the solids of the composition of said epoxy resin i);

about 40%) by weight of the amine-functional silicone resin ii), relative to the total weight of the solids of the composition;

about 25 by weight of the methoxy-functional silicone resin iii) relative to the total weight of the solids of the composition ;

about 8%) by weight of the end functional polydimethylsiloxane iv), relative to the total weight of the solids of the composition; and the remaining % amount to 100% is comprised of said catalyst and optional agents.

The % range amounts of i), ii) iii) and iv) one or more catalyst and any optional agent are understood to mean that the total % of all components can't be greater than 100%> when a combination of the upper ranges can theoretically lead to a value greater than 100%>. In other words, the total amount of all components combined together are selected to that it is no greater than 100% .

In the following examples, the curing process is accelerated by the addition of catalysts at the end of the formulation, i.e. when all other components are admixed. The test sample aluminum beams for the test method were then dipped in the freshly prepared formulation, and allowed to drip and cure at room temperature for at least 5 days. In general, the coatings were dry to the touch within 8 hours, through cured after 24 hours and fully cured after 3-5 days. It is understood that kits of a least 2 parts could be prepared by combining/mixing chemically compatible components, such that the end-user can more easily prepare the pre-cured coating composition.

EXAMPLES

Example 1

Component wt (g) wt %

Eponex 1510 (epoxy resin) 6 27.0 DC 3055 (amino-silicone resin) 8 36.0

DC 3074 (methoxy-silicone resin) 6 27.0

DMS-S31 * 2 9.0

Ti(0-z^'Pr)₂acac₂ 0.1 0.5

SnBu₂laureate₂ 0.1 0.5

* OH-terminated polydimethylsiloxane 1000 cSt from Gelest

Example 2

Component wt (g) wt %

Eponex 1510 (epoxy resin) 6 27.0

DC 3055 (amino-silicone resin) 8 36.0

DC 3074 (methoxy-silicone resin) 6 27.0

PDM-0821 * 2 9.0

Ti(0-/^'Pr)₂acac₂ 0.1 0.5

SnBu₂laureate₂ 0.1 0.5

* Diphenylsiloxane-dimethylsiloxane copolymer 100-125 cSt from Gelest

Example 3

Component wt (g) wt %

Eponex 1510 (epoxy resin) 6 27.0

DC 3055 (amino-silicone resin) 8 36.0

DC 3074 (methoxy-silicone resin) 6 27.0

AK1000 * 2 9.0

Ti(0-/^'Pr)₂acac₂ 0.1 0.5

SnBu₂laureate₂ 0.1 0.5

* Polydimethylsiloxane 1000 cSt from Wacker

Example 4

Component wt (g) wt %

Eponex 1510 (epoxy resin) 6 27.0

DC 3055 (amino-silicone resin) 8 36.0 DC 3074 (methoxy-silicone resin) 6 27.0

PMM-1015 * 2 9.0

Ti(0-z^'Pr)₂acac₂ 0.1 0.5

SnBu₂laureate₂ 0.1 0.5

* Phenylmethylsiloxane-dimethylsiloxane copolymer 50 cSt from Gelest

Example 5

Component wt (g) wt %

Eponex 1510 (epoxy resin) 6 27.0

DC 3055 (amino-silicone resin) 8 36.0

DC 3074 (methoxy-silicone resin) 6 27.0

DMS-S33 * 2 9.0

Ti(0-/^'Pr)₂acac₂ 0.1 0.5

SnBu₂laureate₂ 0.1 0.5

* OH-terminated polydimethylsiloxane 3500 cSt from Gelest

Example 6

Component wt (g) wt %

Eponex 1510 (epoxy resin) 6 27.0

DC 3055 (amino-silicone resin) 10 45.0

DC 3074 (methoxy-silicone resin) 6 27.0

Ti(0-/^'Pr)₂acac₂ 0.1 0.5

SnBu₂laureate₂ 0.1 0.5

Example 7

Component wt (g) wt %

Eponex 1510 (epoxy resin) 6 24.8

DC 3055 (amino-silicone resin) 10 41.3

DC 3074 (methoxy-silicone resin) 6 24.8

DMS-S31 * 2 8.3 Ti(0-z^'Pr)₂acac₂ 0.1 0.4

SnBu₂laureate₂ 0.1 0.4

* OH-terminated polydimethylsiloxane 1000 cSt from Gelest

Example 8

Component wt (g) wt %

Eponex 1510 (epoxy resin) 6 22.9

DC 3055 (amino-silicone resin) 10 38.2

DC 3074 (methoxy-silicone resin) 8 30.5

DMS-S31 * 2 7.6

Ti(0-/^'Pr)₂acac₂ 0.1 0.4

SnBu₂laureate₂ 0.1 0.4

* OH-terminated polydimethylsiloxane 1000 cSt from Gelest

Example 9

Component wt (g) wt %

Eponex 1510 (epoxy resin) 6 24.7

DC 3055 (amino-silicone resin) 10 41.1

DC 3074 (methoxy-silicone resin) 6 24.7

DMS-S31 * 2 8.2

Tinuvin 123 ** 0.12 0.5

Ti(0-/^'Pr)₂acac₂ 0.10 0.4

SnBu₂laureate₂ 0.10 0.4

* OH-terminated polydimethylsiloxane 1000 cSt from Gelest

** HALS light stabilizer from BASF

Example 10

Component wt (g) wt %

Eponex 1510 (epoxy resin) 3 24.6

DC 3055 (amino-silicone resin) 5 40.9

DC 3074 (methoxy-silicone resin) 3 24.6 DMS-S31 * 1 8.2

Tinuvin 123 ** 0.12 1.0

Ti(«-BuO)₄ 0.05 0.4

SnBu₂laureate₂ 0.05 0.4

* OH-terminated polydimethylsiloxane 1000 cSt from Gelest

** HALS light stabilizer from BASF

11 faut aj outer une position de repli pour le catalyseur de Ti

Example 11

Component wt (g) wt %

Silikopon EF * 10 76.9

Dynasylan Ammo **

2 15.4 ("monomelic" aminosilane)

DMS-S31 *** 1 7.7

* Silicone epoxy hybrid from Evonik Industries

** 3-Aminopropyltrimethoxysilane from Evonik Industries

*** OH-terminated polydimethylsiloxane 1000 cSt from Gelest

Example 12

Component wt (g) wt %

Eponex 1510 (epoxy resin) 3 24.6

DC 3055 (amino-silicone resin) 5 40.9

DC 3074 (methoxy-silicone resin) 3 24.6

Fluorolink ElOH * 1 8.2

Tinuvin 123 ** 0.12 1.0

Ti(0-/^'Pr)₂acac₂ 0.05 0.4

SnBu₂laureate₂ 0.05 0.4

* OH-terminated PFPE from Solvay

** HALS light stabilizer from BASF

Example 13 Component wt (g) wt %

Eponex 1510 (epoxy resin) 3 24.6

DC 3055 (amino-silicone resin) 5 40.9

DC 3074 (methoxy-silicone resin) 3 24.6

Fluorolink S10 * 1 8.2

Tinuvin 123 ** 0.12 1.0

Ti(0-z^'Pr)₂acac₂ 0.05 0.4

SnBu₂laureate₂ 0.05 0.4

* triethoxysilane-terminated PFPE from Solvay

** HALS light stabilizer from BASF

Example 14

Component wt (g) wt %

Eponex 1510 (epoxy resin) 3 24.6

DC 3055 (amino-silicone resin) 5 40.9

DC 3074 (methoxy-silicone resin) 3 24.6

DMS A32 * 1 8.2

Tinuvin 123 ** 0.12 1.0

Ti(0-/^'Pr)₂acac₂ 0.05 0.4

SnBu₂laureate₂ 0.05 0.4

* H₂-terminated polydimethylsiloxane from Gelest

** HALS light stabilizer from BASF

Example 15

Component wt (g) wt %

Eponex 1510 (epoxy resin) 3 24.6

DC 3055 (amino-silicone resin) 5 40.9

DC 3074 (methoxy-silicone resin) 3 24.6

DMS C21 * 1 8.2

Tinuvin 123 ** 0.12 1.0 Ti(0-z^'Pr)₂acac₂ 0.05 0.4

SnBu₂laureate₂ 0.05 0.4

* carbinol-terminated polydimethylsiloxane from Gelest

** HALS light stabilizer from BASF

Example 16

Component wt (g) wt %

Eponex 1510 (epoxy resin) 3 24.6

DC 3055 (amino-silicone resin) 5 40.9

DC 3074 (methoxy-silicone resin) 3 24.6

MOH 1000 * 1 8.2

Tinuvin 123 ** 0.12 1.0

Ti(0-/^'Pr)₂acac₂ 0.05 0.4

SnBu₂laureate₂ 0.05 0.4

* monosilanol -terminated polydimethylsiloxane 1000 cSt from Andisil

** HALS light stabilizer from BASF

TEST METHOD AND RESULTS

A method using a centrifuge, (Centrifugal Adhesion Test; CAT) was developed at AMIL (Anti- Icing Materials International Laboratory) to measure the shear adhesion strength of ice on many substrate types. The tests were conducted on an impeller, a 6061 T6 aluminum flat bar, 32 mm wide, 0.6 mm thick, which is then cut into small beams 340 mm in length. Thereto, an impeller was coated with the test sample at one impeller tip over a surface of approximately 1500 mm .

The method is a two-step procedure performed in AMIL's low-speed, closed-loop Icing Wind Tunnel (IWT) using a standard conditions of:

Ambient test temperature of - 15°C,

Liquid water content of 0.8 g/m³,

Median volumetric diameter of 27 ± 3 μιτι,

Air speed of 15.0 ± 0.5 m/s. In the first step, an ice layer was built up by depositing a water fog on to the coated surface, resulting in an ice thickness of typically 8 mm over said surface of approximately 1152 mm². The impeller was balanced by a counter weight mounted on the other impeller tip. The impeller was then mounted on a shaft in a centrifuge chamber. On the outer wall of the centrifuge, accelerometers were mounted which could detect the impact of an object colliding to said centrifuge Wall. The rotational speed of the impeller was gradually increased with about 270 rpm/sec up to the point that ice-like mass detached from the impeller tip. The point in time at which the ice-like mass released from the tip surface was detected almost instantly by the accelerometers attached at the centrifuge wall. When the pulsed signal of the accelerometer was detected, the actual rpm value of the impeller was fixed. From 1) final fixed rpm value, 2) the radial distance between the mass centre point of ice and axis of rotation, 3) the ice mass and 4) the air shear force, the critical shear between ice and coating surface at which detachment occurs, was determined. The latter is referred to as ice adhesion strength (E). The adhesion reduction factor (ARE) is defined as E alu/E coating, Wherein E alu corresponds to the force required to shear off the ice mass from the uncoated aluminum surface.

TABLE 1

Coating Shear Stress (MPa) ARF

Example 1 0.029 18

Example 2 0.236 2

Example 3 0.062 8

Example 4 0.260 2

Example 5 0.046 11

Example 6* - -

Example 7 0.022 23

Example 8 0.066 8

Example 9 0.022 30

Example 10 0.065 8

Example 11 0.057 10

Example 12 0.092 6 Example 13 0.230 2

Example 14 0.054 10

Example 15 0.032 17

Example 16 0.026 21

Enercode White 0.032 21

Enercode Clear 0.035 19

StaClean 0.117 6

NuSil R-1082 0.065 8

NuSil R-3975 0.096 5

* the ice did not dislodge from the sample beam indicating that its adherence to the coating is greater than bare aluminum.

Various polydimethylsiloxane additives were added to a mixture of epoxy resin, methoxy- functional silicone resin, amine-functional silicone resin and catalysts. The coating composition which includes a hydroxyl-terminated-polydimethylsiloxane (Example 1) provided a surface with a greater ARF value as compared to non-functional polydimethylsiloxanes (Examples 2-4).

The inclusion of a higher molecular weight hydroxyl-terminated-polydimethylsiloxane also led to an ARF value above 10 (Example 5), whereas a comparative coating with no end-functional polydimethylsiloxane (Example 6) exhibited no icephobic properties as compared to bare aluminium. Also, changing the ratio of epoxy resin : methoxy-functional silicone resin : amine- functional silicone resin from 3 :4:3 (Example 1) to 3 :5:3 (Example 7) and 3 :5:4 (Example 8) allowed to maintain icephobic properties, at least as good as or better than some commercial products (see last 5 entries in table 1) . Adding Tinuvin 123, an HALS light stabilizer from BASF, increased the ARF value to 30 (Example 9). Surprisingly, the choice of catalyst had a major influence on the coating's ice adhesion. For example the use of Ti(«-BuO)₄, commonly employed in the prior art, instead of Ti(0-z^'Pr)₂acac₂ lead to a lower ARF value (Example 10) indicating a significant increase in ice adhesion. Thus, Ti(0-/^'Pr)₂acac₂ was deemed a superior catalyst for preparing icephobic compositions of the present disclosure.

A comparative composition using a monomeric aminosilane provided a lower ARF value (Example 11). However, more importantly, it has been observed that epoxy-siloxane based on monomelic aminosilanes lead to a wrinkled surface, which increase surface roughness that, although not bound by any a particular theory, could explain the lower ARF value. This surface wrinkling effect was not observed in the compositions of the present disclosure using polymeric amino-silicone resin.

In addition, epoxy-siloxane composions made from a "monomeric" aminoalkyl-trialkoxysilane (such as Dynasylan Ammo) require moisture from the air and the outer layer begins to solidify first to form a film on the surface, commonly referred to as a skin, while the subsurface mixture is initially in a liquid state. Through curing the compositions of the present disclosure to a solid state did not require exogenous water. For example, a freshly prepared mixture according to example 7 was placed in a closed desiccated calcium chloride environment and through curing to a solid state occurred within 8 hours. In contrast, a freshly prepared mixture according to example 11 (using Dynasylan Ammo) placed in the same desiccated environment did not cure after 48 hours, even on the surface. Curing the coating compositions of the present disclosure does not depend on airflow, coating thickness and humidity.

The use of di-endfunctional PFPE (perfluoropolyether) did not provide coatings of significant icephobicity (Examples 12 and 13), while the use of amine-terminated polydimethylsiloxane (Example 14) had a less pronounced effect on icephobicity as compared to silanol -terminated polydimethylsiloxanes. However, both carbinol-terminated and monosilanol-terminated polydimethylsiloxanes provided icephobic coatings (Examples 15 and 16).

Also tabulated are ARF values obtained on commercially available icephobic coatings, namely Enercode, Stay clean and NuSil. While the former exhibits icephobic properties, the silicone coating is fragile by vitue of its polyorganosiloxane nature.

It is expected that the coatings described herein will be also be useful for structures exposed to freezing elements, such as, but not limited to, navigation vessels, electric power infrastructures, ocean rigs, bridges and aircrafts.

The compositions of the present disclosure can be prepared according to the procedures denoted in the examples or modifications thereof using readily available starting materials and conventional procedures or variations thereof well known to a practitioner of ordinary skill in the art. The above examples are given for illustrative purposes only and are not intended to limit the invention in any way.

Claims

Claims:

1. A coating composition comprising at least: i) an epoxy resin;

ii) an amino-functional silicone resin;

iii) a methoxy-functional silicone resin;

iv) an end functional polydimethylsiloxane and

one or more catalyst.

2. The coating composition of claim 1, wherein said epoxy resins is comprising a non- aromatic epoxy resins comprising more than one epoxy group per molecule

3. The coating composition of claim 2, wherein said non-aromatic epoxide resin has two 1,2 epoxide group per molecule.

4. The coating composition of any one of claims 1 to 3, wherein said epoxy resins is comprising hydrogenated bisphenol A-type epoxy resin.

5. The coating composition of any one of claims 1 to 4, wherein said amino functional polysiloxane resin comprises the units: (R3SiOi ₂)_w (1); (R₂Si0₂/₂)_x (2); (RSi03/₂)_y (3) and

wherein w+x+y+z=l, R is selected from the group consisting of an alkyl group having up to four carbon atoms, an aryl group, an aminofunctional hydrocarbon group having up to four carbon atoms or alkoxy groups having up to four carbon atoms, w has a value of less than 0.4, x has a value of greater than 0.15, y has a value greater than zero to 0.7, z has a value of less than 0.2, at least 10 mole percent of silicon atoms in unit (2) contain aminofunctional hydrocarbon groups, with an amine equivalent weight ranging from about 150 to about 350 g/NH.

6. The coating composition of claim 5, wherein, z = 0, the R groups are Methyl in (1), the R groups are Methyl and Phenyl, or Methyl and 3-Aminopropyl in (2), the R group is Phenyl or 3- Aminopropyl in (3) with an high amine content of about 250 g/NH and less than 2% of methoxy radicals.

7. The coating composition of any one of claims 1 to 6, wherein said methoxy-functional silicone resins comprise the units: (R'3SiOi ₂)_W' (J'); (R'₂Si0₂/₂)_X' (2'); (R' Si03/₂)_y' and (Si0_4/2)_z> ( ') : wherein w'+x'+y'+z'=l, R' is selected from the group consisting of an alkyl group having up to four carbon atoms, an aryl group or an alkoxy groups having up to four carbon atoms and the polysiloxane ingredient have a molecular weight in the range of from about 400 to about 10,000.

8. The coating composition of claim 7, whereinthe R' groups are Methoxy, Methyl and Phenyl, with a methoxy content of about 15% and a molecular weight in the range of from about 1200 to about 1900.

9. The coating composition of any one of claims 1 to 8, wherein said end-functional polydimethylsiloxanes is having the formula:

wherein R₅ is an alkyl up to four carbon atoms, a hydroxyl group, a 3-aminopropyl, a 3- hydroxypropyl or a 3-(hydroxyethoxy)propyl; R6 is a hydroxyl group, a 3-aminopropyl, a 3- hydroxypropyl or a 3 -(hydroxy ethoxy)propyl and where n is selected so that the molecular weight for the polysiloxane is 400 to 1 10,000.

10. The coating composition of claim 9, wherein said end-functional polydimethylsiloxanes is a mono or bis silanol-terminated polydimethylsiloxanes.

11. The coating composition of any one of claims 1 to 10, wherein said catalysts is one or more organometallic derivatives of titanium, tin, bismuth, zinc, iron, lead, manganese, zirconium or cobalt.

12. The coating composition of claim 11, wherein said catalysts is dibutyltin dilaureate, diisoporpoxy titanium bis(acetylacetonate) or a combination thereof.

13. The coating composition of any one of claims 1 to 12, further comprising one or more additional agent which are solvents, adhesion promoters, stabilizing agents, reinforcers, fillers, corrosion inhibitors, pigments, plasticisers, suspending agents, thixotropic agents, diluents, reactive diluents, UV light stabilizers, HALS, surfactant, or mixture thereof.

14. A coating composition comprising:

- an epoxy resin i) which is a hydrogenated bisphenol A-type epoxy resin having an epoxide equivalent weight is 100 to about 500;

- an amino-functional silicone resin ii) comprising the units: (R3SiOi ₂)_w (1); (R₂Si0₂/₂)_x (2); (RSi0₃/₂)_y (3) and (Si0₄/₂)_z (4);

- a methoxy-functional silicone resin iii) comprising the units: (R'₃SiOi/₂)_W' (7'); (R'₂Si0₂/₂)_X' (2'); (R'Si0₃/₂)_y ^> (·?') and (Si0_4/2)_z ^> (¥');

wherein w'+x'+y'+z'=l, R' groups are Methoxy, Methyl and Phenyl, with a methoxy content of about 15% and a molecular weight in the range of from about 1200 to about 1900 - an end functional polydimethylsiloxane iv) is having the formula:

a catalyst which is diisopropoxy titanium bis(acetylacetonate), dibutyltin dilaurate or a combination thereof.

15. A method for preparing the coating composition as defined in any one of claims 1 to 14 comprising

1) blending said epoxy resin i), said amino-functional silicone resin ii), said methoxy-functional silicone resin iii) and said end functional polydimethylsiloxane iv) ; and

2) blending the mixture resulting from 1) with one or more catalyst.

16. The method of claim 15 comprising

1) blending a first composition comprising said epoxy resin i) together with said end functional polydimethylsiloxane iv);

blending a second composition comprising said amino-functional silicone resin ii) together with said methoxy-functional silicone resin iii); and

17. The method of claim 15 comprising

1) blending a first composition comprising said epoxy resin i) together with said end functional polydimethylsiloxane iv) and one or more catalyst;

blending a second composition comprising said amino-functional silicone resin ii) together with said methoxy -functional silicone resin iii) and one or more catalyst; and

2) blending the first and second compositions resulting from 1) .

18. A method for reducing ice-adhesion to a substrate comprising applying to said substrate the coating composition as described in any one of claims 1 to 14, or applying the coating composition as prepared in preparation methods of any one of claims 15 to 17 wherein said coating composition is applied prior to the curing of said composition.

19. An article surface-coated with the coating composition as described in any one of claims 1 to 14, or prepared as defined in any one of claims 15 to 17 .