WO2019087081A1

WO2019087081A1 - Polyurea composition comprising filler and reactive silane compound and methods

Info

Publication number: WO2019087081A1
Application number: PCT/IB2018/058512
Authority: WO
Inventors: Chad M. AMB; Saswata CHAKRABORTY; Zai-Ming Qiu; Alexander J. KUGEL
Original assignee: 3M Innovative Properties Company
Priority date: 2017-11-01
Filing date: 2018-10-30
Publication date: 2019-05-09

Abstract

A method of forming a coating on a surface of a pipeline comprises the steps of: a) providing a polyurea coating composition comprising a first part comprising at least one polyisocyanate, and a second part comprising at least one polyamine; and b) combining the first part and the second part to form a liquid mixture. The first part, second part, or liquid mixture further comprises cl) at least one inorganic filler and at least one silane compound comprising a functional group that is reactive with the first or second part; or c2) a siliceous filler having an aspect ratio of at least 2: 1; and d) applying the liquid mixture to internal surfaces of the pipeline; and e) allowing the mixture to set forming a cured coating.

Description

POLYUREA COMPOSITION COMPRISING FILLER

AND REACTIVE SILANE COMPOUND AND METHODS

BACKGROUND

Trenchless methods for structural renovation of drinking water pipelines include the pipe in pipe method, pipe bursting method, and polyethylene thin wall lining method. As described in U.S. Patent No. 7,189,429, these methods are disadvantaged by their inability to deal with multiple bends in a pipeline and the fact that lateral connection pipes to customers' premises are disconnected and then reinstated after execution of the renovation process.

Various compositions have been described that are suitable to form a coating on the internal surface of a drinking water pipeline. See for example US 2013/0116379 and

US2015/0104652.

SUMMARY

In one embodiment, a method of forming a coating on a surface of a pipeline is described. The method comprises the steps of: a) providing a polyurea coating composition comprising a first part comprising at least one polyisocyanate, and a second part comprising at least one polyamine; and b) combining the first part and the second part to form a liquid mixture wherein the first part, second part, or liquid mixture further comprises cl) at least one inorganic filler and at least one silane compound comprising a functional group that is reactive with the first or second part; or c2) a siliceous filler having an aspect ratio of at least 2: 1; and d) applying the liquid mixture to internal surfaces of the pipeline; and e) allowing the mixture to set forming a cured coating.

In another embodiment, a method of improving the wet tensile strength of a polyurea coating composition is described. The method comprises a) providing a polyurea coating composition comprising a first part comprising at least one polyisocyanate, and a second part comprising at least one polyamine; and b) combining the first part and the second part to form a liquid mixture wherein the first part, second part, or liquid mixture further comprises cl) at least one inorganic filler and at least one silane compound comprising a functional group that is reactive with the first or second part; or c2) a siliceous filler having an aspect ratio of at least 2: 1; d) applying the liquid mixture to a surface; and e) allowing the mixture to set forming a cured coating.

In other embodiments, polyurea coating compositions are described comprising a) a first part comprising at least one polyisocyanate, b) a second part comprising at least one polyamine, and an optional third part. In one embodiment, the total polyurea coating composition comprises at least 5% by volume of the total composition of filler and a silane compound comprising a functional group that is reactive with the first or second part. In another embodiment, the total polyurea coating composition comprises at least 5% by volume of the total composition of siliceous filler having an aspect ratio of at least 2: 1. In some embodiments, the siliceous filler has an aspect ratio of at least 3: 1, 4: 1, or 5: 1.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 depicts a perspective view of a pipe comprising a coating of a caliper of at least 5 mm. FIG. 2 depicts a perspective view of a pipe comprising a coating not having a caliper of at least 5 mm.

FIG. 3 is a plot of a line fit of measured stress values over time to failure for CE-1.

DETAILED DESCRIPTION

The present invention provides a polyurea composition, typically comprising at least two- parts. In favored embodiments, the polyurea composition is suitable for applying to internal pipeline surfaces so as to form an impervious lining suitable for contact with drinking water. By virtue of its rapid setting characteristics and insensitivity to moisture after curing, the

composition is particularly useful as an "in-situ" applied lining for refurbishment of existing drinking water pipelines.

The first part of the two-part coating composition generally comprises at least one polyisocyanate and the second part comprises at least one polyamine. After application and curing, the coating composition comprises the reaction product of such first and second components. The reacted coating comprises urea groups (-NR-C(O)-NR-). Polymers containing urea groups are often referred to as polyureas. When the two-part coating composition comprises other isocyanate reactive or amine reactive components, the reacted coating may comprise other groups as well.

To avoid applying multiple coating layers, it is advantageous to apply a coating at a thickness or caliper greater than 5 mm. In order to apply a caliper of at least 5 mm in a single pass, the coating composition typically comprises filler(s). The inclusion of the filler can also contribute to mechanical properties, such as tensile strength and creep rupture strength.

With reference to FIG. 1, pipe 100 illustrates the polyurea coating composition 150, as described herein, having a caliper of at least 5 mm. In contrast, with reference to FIG. 2, pipe 200 illustrates the polyurea coating composition (250 and 260) not having a caliper of at least 5 mm. When the viscosity of the liquid mixture is too low, the coating sags such that portion 250 may have a thickness greater than 5 mm. However, portions 260 have a caliper significantly less than 5 mm.

The polyurea coating composition comprises at least 1, 2, 3, 4, 5 vol.-% or greater of filler, based on the total volume of the coating composition. In some embodiments, the vol.-% of filler is at least 6, 7, 8, 9 or 10 vol.-%. The concentration of filler is typically no greater than 35 vol-% based on the total volume of the coating composition. In some embodiments, the concentration of filler is typically no greater than 25, 24, 23, 22, 21 or 20 vol.-% based on the total volume of the coating. In some embodiments, the first part comprises the amount of filler just described. In some embodiments, the second part comprises the amount of filler just described. In other embodiments, both the first and second part comprise filler such that the total amount of filler is within the concentration ranges just described.

A filler is a solid, insoluble particulate material often employed to add bulk volume or to extend the pigment capabilities without impairing the reactive chemistry of the coating mixture. Many fillers are natural inorganic minerals such as calcium carbonate (e.g. whiting), dolomite (calcium magnesium carbonate), and siliceous fillers including talc, glass, ceramic, clay (e.g. kaolin), natural and synthetic silica and woilastonite (calcium silicate).

Pigments, such as titanium dioxide, can concurrently function as a colorant and filler. Further, molecular sieves (e.g. aluminosilicate) can concurrently function as a desiccant (e.g. water scavenger) and a filler. Inorganic thixotropes, such as fumed silica, can concurrently function as a thixotrope and a filler. Other thixotropes comprise an organic material such as polyamides, waxes, castor oil derivatives, and others, as described for example in US 4,923,909 and US 5,164,433. These may be soluble and/or semisoluble in the resin and are not considered "fillers". Thixotropes often can provide a suitable viscosity at lower concentrations than other types of filler and therefore can be advantageous for reducing the filler concentration.

Other fillers include ceramic microspheres, hollow polymeric microspheres such as those available from Akzo Nobel, Duluth, GA, (under the trade designation "EXPANCEL 551 DE"), and hollow glass microspheres (such as those commercially available from 3M Company, St. Paul, MN, under the trade designation "K37"). Hollow glass microspheres are particularly advantageous because they demonstrate excellent thermal stability and a minimal impact on dispersion viscosity and density. Other fillers can be solid insoluble particulates comprised of insoluble organic matter. Exemplary fillers of this type could include nylon, polyethylene, polypropylene, polyamides, etc.

The polyurea coating composition typically comprises an inorganic filler having a mean particle size greater than 1 micron. By inorganic filler, it is meant that the filler in the absence of an organic surface treatment comprises an organic carbon content of less than 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 wt.-%. When carbon is present, it is typically in the form of carbonate.

In some embodiments, the filler has a mean particle size of at least 2, 3, 4, 5, 10, 15, 20,

25, 30, 35, 40, 45, or 50 microns. Depending on the particle size distribution, the filler may comprise various (weight or volume) fractions greater than or less than the mean particle size. For example, in some embodiments, the filler may contain up to 1, 2, 3, 4, or 5 wt.-% or vol.-% of particles 2X or 3X the mean particle size. In other embodiments, the filler may contain up to 6, 7, 8, 9, or 10 wt.-% or vol.-% of particles 2X the mean particle size. In other embodiments, the filler may contain up to 15, 20, 25, or 30 wt.-% or vol.-% of particles less than half the size of the median particle size. The particle size of the filler can be determined using optical microscopy, Scanning Electron Microscopy and the like, in combination with any image analysis software. For example, software commercially available as free ware under the trade designation "IMAGE J" from NIH, Bethesda, MD. Suitable microscopy methods are described in ASTM E2651-13 and ASTM E1617-09 (2014).

The BET surface area of fillers can vary. Typically, the smaller the size, the greater the surface area. Hence, (e.g. fumed silica) thixotropes typically have a relatively high BET surface area. For example, the BET surface area may be at least 25, 50, 75 or 100 m²/g. In contrast, fillers having a mean particle of greater than 1, 2, 3, 4, or 5 microns often have a BET surface area of at least 1, 2, or 3 m²/g ranging up to about 5, 6, 7, 8, 9, or 10 m²/g.

In some embodiments, the filler is a non-siliceous filler, meaning that the silica content is less than 25 wt.-%. One example of a non-siliceous filler is alumina trihydrate that typically comprises greater than 95, 96, 97, 98 or 99 wt.-% Al(OH)₃. Another example of a non-siliceous filler is dolomite, a common rock-forming mineral composed of calcium magnesium carbonate, CaMg(C0 )₂.

In favored embodiments, the filler is a siliceous filler, meaning that the silica content is at least 25 wt.-%. In some embodiments, the siliceous filler comprises at least 30, 35, 40, 45 or 50 wt.-% of silica (silicon atom and two oxygen atoms for each silicon atom). In typical embodiments, the siliceous filler comprises silica as just described and other inorganic materials, such as other metal oxides. In some embodiments, such as in the case of wollastonite, the silica content ranges from about 50 to 55 wt.-%. In some embodiments, the siliceous filler may comprise 40-45 wt.-% of other metal oxides. In some embodiments, the siliceous filler comprises calcia (CaO) in an amount ranging from 40 to 50 wt.-%. The specific gravity of a siliceous filler can vary depending on the silica content and densification. In some embodiments, the siliceous filler has a specific gravity of at least 2.15 g/cc ranging up to 2.2 g/cc or 2.3 g/cc. When the siliceous filler comprises other metal oxides the specific gravity may be greater than 2.3 g/cc. For example, the specific gravity may range up to 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0 g/cc.

In some embodiments, the filler is substantially spherical or has a relatively low aspect ratio (i.e. ratio of the width to the length). For example, the aspect ratio is no greater than 2: 1, 1.9: 1, 1.8: 1, 1.7: 1, 1.6: 1, 1.5: 1, 1.4: 1, 1.3, 1.2: 1, 1.1: 1, or 1: 1. As used herein "length" refers to the maximum dimension and "width" refers to the dimension orthogonal to the length.

Examples of siliceous fillers are 3M™ Fused Silica 20 and 40, commercially available from 3M.

In favored embodiments, the filler has an aspect ratio of at least 2: 1, 2.5: 1, 3: 1, 3.5: 1, 4: 1, 4.5: 1, or 5: 1. In some embodiments, such fillers may be described as acicular, or in other words needle-like. In some embodiments, the acicular filler has an aspect ratio ranging up to 10: 1, 11: 1, 12: 1, 13: 1, 14: 1 or 15: 1. In some embodiments, the acicular filler has an aspect ratio ranging up to 20: 1, 25: 1 or 30: 1.

In one embodiment, the high aspect ratio filler has an average length of at least 25 or 50 microns and no greater than 75 microns. In another embodiment, the high aspect ratio filler has an average length of at least 75 or 100 microns and no greater than 150 microns. The average width of the high aspect ratio filler is typically at least 1, 2, 3, or 4 micron and no greater than 10 microns. Suitable high aspect (e.g. siliceous) filler includes wollastonite commercially available from Vanderbilt Minerals, LLC under the trade designations "VANSIL™ WG" and "VANSIL™ HR-1500".

In some embodiments, (e.g. siliceous) filler with higher aspect ratios have been found to improve the dry and wet mechanical properties, such as tensile strength, even in the absence of a silane compound comprising a functional group that is reactive with the first or second part.

In some embodiments, the cured polyurea coating composition has a dry tensile strength of at least 40, 41, 42, 43, 44, or 45 MPa ranging up to 50, 55 or 60 MPa. In some embodiments, the cured polyurea coating composition has a wet tensile strength of at least 25, 30, 35, or 40 MPa. By wet tensile strength, it is meant after soaking the sample in deionized water until saturated, e.g. for 7 days as described in greater detail in the tensile strength and elongation test set forth in the examples. Thicker samples may need to soak a longer duration of time to reach saturation.

In some embodiments, the cured polyurea coating composition has a dry and/or wet Young's modulus of at least 3000, 3500, or 4000 MPa. The Young's modulus is typically no greater than 5000 or 4500 MPa. The Young's modulus can be determined according to ASTM D-638-14, as further described in the test method of the examples.

In some embodiments, the polyurea coating composition comprises a mixture of fillers.

For example, the polyurea coating composition may comprise a thixotrope, a molecular sieve in combination with a third filler. The third filler is typically present at a higher concentration than the thioxtrope and or molecular sieve. In favored embodiments, the third filler is preferably siliceous and has an aspect ratio of greater than 2: 1, as previous described.

Thixotropes often have an average particle size no greater than 1 micron. In some embodiments, the thixotrope may be characterized as an aggregate having an aggregate length of less than 1 micron. In some embodiments, the thixotrope has an average (e.g. aggregate) particle size of no greater than 900, 800, 700, 600, 500, 400, or 300 nanometers. In some embodiments, the thixotrope has an average (e.g. aggregate) particle size of greater than 150 nanometers. In some embodiments, the thixotrope may have a silica (S1O2) concentration greater than 50, 60, 70, 80, 90, or 95 wt.-% or greater. The thixotrope may be commercially available further comprising a surface treatment. One suitable thixotrope is fumed silica, such as commercially available from Cabot Corporation as CAB-O-SIL™ TS-720. This thixotrope is described as being treated with a dimethyl silicone fluid. The surface treatment replaces many of the surface hydroxyl groups on the fumed silica with poly-dimethyl- siloxane polymer. The surface treatment may be present at an amount such that the carbon content of the thixotrope is at least 2, 3, 4, or 5 wt.-% and typically less than 10 wt.-% of the thixotrope.

In some embodiments, the amount of thixotrope employed in the total polyurea coating composition is at least 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 wt.-%. In some embodiments, the concentration of thixotrope employed in the polyurea coating composition is typically no greater than 10 wt.-%. With regard to volume percent, the amount of thixotrope employed in the polyurea coating composition is at least 0.5, 1, 1.5, 2, or 2.5 vol.-% and typically no greater than 5 vol.-%. The first part, the second part, or a combination of the first and second part may contain thixotrope.

In some embodiments, the polyurea coating composition comprises a water adsorbing molecular sieve. Type 4A sieves generally comprise crystalline sodium aluminosilicate with a pore size of about 4 angstroms. This sieve size is suitable for adsorbing water. Type 3A sieves comprises potassium aluminosilicate with a pore size of about 3 angstroms. Type 3 A are the most selective type of molecular sieves for water adsorption. Molecular sieves are commercially available from various suppliers. For example, a Type 3 A molecular sieve is available from Zeochem LLC, as "PURMOL 3ST". Such material is described as having a primary crystal size of 4.6 microns and a typical particle size of 24 microns.

In some embodiments, the water adsorbing sieve has a water adsorption capacity of at least 5, 10, 15, or 20% w/w at 50% relative humidity at 20°C in 24 hours. In other words, 1 gram of water adsorbing sieve may absorb 0.05, 0.10, 0.15, or 0.2 grams of water at such conditions.

When the molecular sieve comprises crystalline sodium aluminosilicate and/or potassium aluminosilicate at a high level of purity (e.g. at least 95%, 96%, 97%, 98%, or 99%), the molecular sieve has a pore size of 3-4 angstroms. When the purity is less than 100%, the molecular sieve may comprise a small amount (e.g. less than 5, 4, 3, 2, or 1 wt.-%) of sieve or pores having a smaller and/or larger pore size. In this embodiment, the molecular sieve may have an average pore size greater than 2.5 or 3 angstroms (e.g. at least 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, or 3.5) and less than 5 angstroms (e.g. no greater than 4.9, 4.8, 4.7, 4.6, or 4.5).

When the pore size is too small, a water molecule is too large to be adsorbed by the molecular sieve. When the pore size is too large, a water molecule can pass through the sieve.

The amount of water adsorbing molecular sieve filler is typically at least 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0 wt.-% of the total coating composition. In some embodiments, the amount of water adsorbing molecular sieve filler is no greater than 5, 4.5, 4, 3.5, 3.0 or 2.5 wt.-% of the total coating composition. The percent by volume is about half the percent by weight.

Although the inclusion of a siliceous filler having a sufficiently high aspect ratio, as previously described, can improve the mechanical properties such as dry and wet tensile strength, it has been found that the wet tensile strength can be improved by inclusion of certain silane compounds. The silane compounds comprise a functional group that is reactive with the (e.g. isocyanate of the) first part or (e.g. polyamine of the) second part of the polyurea coating composition. After combining the first and second part, the functional group reacts (e.g. forms a covalent bond) with (e.g. polyisocyanate(s) of) the first part or (e.g. polyamine(s) of) the second part.

Suitable reactive silanes compounds typically have the following chemical formula:

^[Y-RsJ-SHR¹]_:*

wherein R¹ is independently hydroxy, alkoxy, or alkyl with the proviso that one or two of the R¹ group are hydrolyzable (e.g. alkoxy);

R5 is (e.g. divalent) non-hydrolyzable linking group such as alkylene, arylene, alkarylene, or arylalkyene;

Y is a functional group;

m in an integer equal to 1, 2 or 3, and is typically 2 or 3.

In some embodiments, R5 is (CH₂)n wherein n ranges from 0 to 12, or n ranges from 0 to 3, or n is 2 or 3.

In some embodiments, R¹ is independently a Ci-Ce alkoxy. More typically R¹ is independently a C1-C4 alkoxy such as methoxy and ethoxy. In some embodiments, one R¹ group is alkyl (e.g. methyl or ethyl) and the other two R¹ groups are alkoxy (e.g. methoxy or ethoxy).

Y is typically a (e.g. terminal) amine group, an isocyanate group, an epoxy group, or a (meth)acryl group. In some embodiments, R5 also comprise another (e.g. amine) functional group.

In some embodiments, the silane compounds comprise at least one amine functional group. The amine functional group is typically included in the second part and reacts with the polyisocyanates of the first part. In this embodiment, Y comprises an amine terminal group such as in the case of -NH-CH₂-CH₂-NR²R³, -NR²R³ with R² and R³ being independently selected from the group consisting of H, alkyl, phenyl, benzyl, cyclopentyl and cyclohexyl. In the case of primary amine functional groups, R² and R³ are both H. In the case of secondary amines R² is H and R³ is alkyl, phenyl, benzyl, cyclopentyl and cyclohexyl. In the case of tertiary amine functional groups, R² and R³ are typically both alkyl.

Examples of amino-functional silanes include 3-aminopropyltrimethoxysilane

(SILQUEST A-l 110), 3 -aminopropyltriethoxy silane (SILQUEST A-l 100), 3-(2- aminoethyl)aminoprop- yltrimethoxysilane (SILQUEST A-l 120), SILQUEST A-l 130,

(aminoethylaminomethyl)phenethyltrimethoxysilane, (aminoethylaminomethyl)- phenethyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (SILQUEST A-2120), bis-(.gamma.-triethoxysilylpropyl)amine (SILQUEST A-1170), N-(2-aminoethyl)-3- aminopropyltributoxysilane, 6-(aminohexylaminopropyl)trimethoxysilane, 4- aminobutyltrimethoxysilane, 4-aminobutyltriethoxysilane, p-(2- aminoethyl)phenyltrimethoxysilane, 3-aminopropyltris(methoxyethoxyethoxy)silane, 3- aminopropylmethyldiethoxy- silane, oligomeric aminosilanes such as DYNASYLAN 1146, 3- (N-methylamino)propyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylme- thyldimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)- 3 -aminopropyltrimethoxy silane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3- aminopropylmethyldiethoxysilane, 3 -aminopropylmethyldimethoxy silane, 3 - aminopropyldimethylmethoxysilane, and 3-aminopropyldimethylethoxysilane.

In some embodiments, R5-Y forms a cyclic structure, such as in the case of the following compounds.

CH₂CH₂NH₂

I I ^OCH₂CH₃

k ^Si

ft" \OCH₂CH₃

I I .OMe

k ^Si

^ \0Me

When m is 2 and Y comprises an amine group, the silane compound may be characterized as an amine disilane. In some embodiments, the R5 group can covalently link two silane groups. One representative compound is bis[3-trimethoxylsilyl)propyl] amine, having the formula HN[CH₂)3Si(OMe)3]2.

In other embodiments, the silane compound can be partially hydrolyzed and condensed to form siloxane bonded structures. In some embodiments, the silane compounds comprise as least one isocyanate functional group. The isocyanate functional group is typically included in the first part and reacts with the polyamines of the first part. In this embodiment, Y comprises a (e.g. terminal) isocyanate group. Representative compounds may be characterized as isocyantoalkylalkoxysilane compounds such as 3-isocyantopropyltriethoxy silane, 3-isocyantopropyltrimethoxy silane and

(isocyantomethyl)methyldimethoxy silane.

In some embodiments, the silane compounds comprise as least one (meth)acryl functional group. The (meth) functional group is typically included in the first part and reacts (by Michael addition) with the polyamines of the first part. In this embodiment, Y comprises a (e.g. terminal) (meth)acrylate group. Representative compounds may be characterized as

(meth)acrylalkylalkoxysilane compounds such as (3-acryloxypropyl)trimethoxysilane, methacryloxypropyltrimethoxy silane ; N- (3 - acryloxy-2 -hydroxypropyl)- 3 - aminopropyltriethoxysilane; 0-(methacryloxyethyl)-N-trimethoxysilylpropyl)urethane; N-(3- methacryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane;

methacryloxymethyltriethoxysilane; methacryloxymethyltrimethoxysilane;

methacryloxypropyltriethoxysilane; (3-acryloxypropyl)methyldimethoxysilane;

(methacryloxymethyl)methyldiethoxysilane; (methacryloxymethyl)methyldimethoxysilane;

methacryloxypropylmethyldiethoxysilane; and methacryloxypropylmethyldimethoxysilane.

In some embodiments, the first and/or second part may comprise more than one reactive silane compounds. For example, the first part may comprise a silane compound comprising an isocyanate functional group or a (meth)acryl group and the second part may comprise a silane compound comprising an amine group.

The polyurea coating composition comprises a sufficient amount of filler, preferably in combination with a reactive silane compound such that the wet tensile strength is improved. The concentration of reactive silane compound is typically at least 0.1, 0.2, 0.3, 0.4 or 0.5 wt.-% of the total polyurea coating composition. The concentration of reactive silane compound is typically no greater than 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5 or 1 wt.-%. The concentration of reactive silane is generally dependent at least in part of the concentration of (e.g. siliceous) filler. For example, at 15 vol% (e.g. siliceous) filler, less than 1 wt.-% reactive silane can provide the desired improvement. However, at higher filler concentrations or equal filler concentrations, yet filler having a smaller mean particle size, higher concentrations of reactive silane is typically utilized. In some embodiments, the polyurea coating composition further comprises a second silane compound that lacks functional groups that react with the first and second part of the polyurea coating composition. Such non-reactive silane compounds generally have the chemical formula:

F^SriOR¹), wherein R is independently alkyl as previously described;

R² is independently alkyl, aryl, alkarylene, or arylalkyene; and

m ranges from 1 to 3, and is typically 2 or 3.

Representative silane compounds include propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane,

hexadecyltriethoxysilane, octadecyltrimethoxy silane, octadecyltriethoxysilane,

phenyltrimethoxysilane, phenyltriethoxysilane dimethyldimethoxysilane and

dimethyldiethoxysilane.

In some embodiments, the inclusion of a non-reactive silane compound may be utilized to adjust the elongation properties. For example, inclusion of a non-reactive silane compound wherein R² comprises a longer chain alkyl group, having at least 6, 7, 8, 9, 10, 11, 12 and typically no greater than 24 carbon atoms can increase the elongation.

The non-reactive silane compound is typically added to the polyurea coating composition in an amount by weight less than or equal to the reactive silane. The weight ratio of non-reactive silane to reactive silane can range from 1: 1 to 1:2, 1:3 or 1:4. In some embodiments, the wet tensile strength of the cured polyurea coating composition with filler, but without the reactive silane compound decreases by about 9 or 10%. When the reactive silane compound is included, the wet tensile strength decreases by less than 6, 5, 4, or 3%. In favored embodiments, the inclusion of the reactive silane compound causes an increase in the dry and especially wet tensile strength by at least 1, 2, 3, 4, or 5%. The increase in the dry and especially wet tensile strength can depend on the concentration of filler and range up to 10% or greater. The inclusion of the reactive silane compound alone can decrease the tensile strength, yet increase the elongation, especially the dry elongation. For example, the dry elongation can increase by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10%. In some embodiments, the wet elongation can increase by 1, 2, 3%.

In some embodiments, the cured polyurea coating composition has a dry and/or wet elongation less than 30, 25, 20, 15 or 10%. In some embodiments, the cured polyurea coating composition has a dry and/or wet elongation of at least 1, 2, 3, 4, or 5%.

The filler and silane compound can be added to the polyurea composition in various manners. In typical embodiments, the polyurea coating composition is provided with the fillers(s) and reactive silane compound(s) contained within the first and/or second part. In other words, the polyurea coating composition is commercially available containing both the filler(s) and the reactive silane compounds(s). This may be characterized as having the fillers(s) and the reactive silane compound(s) "pre-added" to the (e.g. two-part) polyurea coating composition. In this embodiment, the reactive polyurea coating composition comprises a) a first part comprising at least one polyisocyanate, and b) a second part comprising at least one polyamine, wherein the first part and/or second part further comprises fillers(s) and reactive silane compound(s) comprising a functional group that reacts with the first and/or second part. More typically, the polyurea coating composition is provided with the fillers(s) and a polyisocyanate-reactive silane compounds(s) contained within the second part. Alternatively, the polyurea coating composition is provided with the fillers(s) and a polyamine-reactive silane compounds(s) contained within the first part.

In another embodiment, the polyurea coating composition may be provided with the fillers(s) contained within the first and/or second part, but not containing the reactive silane compounds(s) in the second part. The reactive silane compound(s) is added to the first or second part prior to combining the first and second part or during combining the first part and the second part. This may be characterized as having the filler(s) pre-added and the reactive silane compound(s) "post-added". In this embodiment, the reactive polyurea coating composition comprises a) a first part comprising at least one polyisocyanate, and b) a second part comprising at least one polyamine, wherein the first part and/or second part further comprises filler(s); and c) a third part comprising reactive silane compound(s).

In yet another embodiment, the polyurea coating composition is provided without the filler(s) and without the reactive silane compounds(s). Both the fillers(s) and reactive silane compounds(s) are (e.g. sequentially) added to the second part prior to combining the first and second part or during combining the first part and the second part. This may be characterized as having the fillers(s) and the reactive silane compounds(s) "post-added" to the (e.g. two-part) polyurea coating composition.

In some embodiments, the filler and reactive silane compounds may be first combined with each other and the added to the first or second part of the polyurea coating composition. For example, the filler may be commercially available "pre-treated" with a reactive silane compound, such as in the case of aminosilane treated wollastonite available from Nyco Minerals under the trade designation "10 AS WOLLASTOCOAT" and from Quarzwerke GmbH under the trade designations "TM939-100" and "TM939-100". The pre-treated fillers typically contain 0.5 to 1 wt.-% of (e.g. amine) reactive silane.

The reactive components such as the polyisocyanate and polyamine can be characterized based on their functionality. Functionality may be calculated by dividing the molecular weight by the equivalent weight. The equivalent weight of isocyanate end groups can be determined by titration procedures such as, for example ASTM D 2572-97. The equivalent weight of amine end groups can be determined by titration procedures such as, for example ASTM D 2074-92. In the case of polyisocyanates, the average functionality is the average number of isocyanate (-NCO) groups of a polyisocyanate. In the case of polyamines, the average functionality is the average number of amine groups of a polyamine. The functionality is typically reported by the supplier. For example, Covestro, Leverkusen, Germany, reports the average functionality of their polyisocyanates. An average functionality is often reported when the material comprises a mixture of compounds. However, when the material is substantially a single compound, the material may be reported as difunctional (e.g. diamine) or trifunctional (e.g. triamine).

The first part of the two-part coating comprises one or more polyisocyanates.

"Polyisocyanate" refers to any organic compound that has two or more reactive isocyanate (-NCO) groups in a single molecule such as diisocyanates, triisocyanates, tetraisocyanates, etc., and mixtures thereof. Cyclic and/or linear polyisocyanate molecules may be usefully employed. The polyisocyanate(s) of the isocyanate component are preferably aliphatic. In typical embodiments, the (e.g. aliphatic) polyisocyanates are selected such that the total composition is substantially free of isocyanate monomer (e.g. less than 0.5%).

Suitable aliphatic polyisocyanates include derivatives of hexamethylene-l,6-diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; isophorone diisocyanate; and 4,4'- dicyclohexylmethane diisocyanate. Alternatively, reaction products or prepolymers of aliphatic polyisocyanates may be utilized. The first part generally comprises at least one aliphatic polyisocyanate. Such aliphatic polyisocyanate typically comprises one or more derivatives of hexamethylene-l,6-diisocyanate (HDI). In some embodiments, the aliphatic polyisocyanate is a derivative of isophorone diisocyanate. The aliphatic polyisocyanate may comprise an uretdione, biuret, and/or

isocyanurate of HDI.

In some embodiments, the first part comprises at least one solvent-free aliphatic polyisocyanate(s) that is substantially free of isocyanate (HDI) monomer, i.e. less than 0.5 % and more preferably no greater than 0.3 % as measured according to DIN EN ISO 10 283. Various solvent-free aliphatic polyisocyanate(s) are available. One type of HDI uretdione polyisocyanate, reported to have an isocyanate content of 21.8 and a viscosity of 150 mPa- s at 23°C is available from Covestro under the trade designation "DESMODUR N 3400". Another HDI polyisocyanate is a trimer, reported to have a viscosity of about 1200 mPa- s at 23°C is available from Covestro under the trade designation "DESMODUR N 3600". Such polyisocyanates typically have an isocyanate content of 20-25%. Another polyisocyanate is an aliphatic prepolymer resin comprising ether groups, based on HDI is available from Covestro under the trade designation

"DESMODUR XP 2599". Yet another aliphatic HDI polyisocyanate is a trimer is available from Covestro under the trade designation "DESMODUR N3800". This material has an NCO content of 11% and a viscosity of 6,000 mPa- s at 23°C. Yet another aliphatic HDI polyisocyanate is a trimer is available from Covestro under the trade designation "DESMODUR N3300". This material has an NCO content of 21.8% and a viscosity of 3,000 mPa- s at 23°C. Yet another aliphatic polyisocyanate resin based on HDI and isophorone diisocyanate is available from Covestro under the trade designation "DESMODUR XP2838". This material has an NCO content of 20% and a viscosity of 3,000 mPa- s at 23°C. One type of HDI biuret polyisocyanate, is available from Covestro under the trade designation "DESMODUR N 3200". This material has an NCO content of 20-25% and a viscosity of 2,500 mPa- s at 23°C.

In some embodiments, the first part comprises a single aliphatic polyisocyanate based on hexamethylene-l,6-diisocyanate (HDI). In this embodiment, the first part may comprise 100 wt- % of a single aliphatic polyisocyanate based on hexamethylene-l,6-diisocyanate (HDI). In some embodiments, the single aliphatic polyisocyanate has a viscosity of no greater than 1,500 mPa- s at 23°C and a functionality ranging from about 2.8 to 3.5, such as "DESMODUR N 3600". In typical embodiments, the first part further comprises additives, as will subsequently be described, such that the first part comprises less than 100 wt-% of polyisocyanate. In some embodiments, the first part comprises a mixture of aliphatic polyisocyanates based on hexamethylene-l,6-diisocyanate (HDI). In one embodiment, the first part comprises a first aliphatic polyisocyanate having a viscosity of no greater than 1,500 mPa- s at 23°C and a functionality ranging from about 2.8 to 3.5, such as "DESMODUR N 3600," and a second aliphatic polyisocyanate having a functionality greater than the first aliphatic polyisocyanate. In some embodiments, the second aliphatic polyisocyanate has an average functionality of at least 3.6, 3.7, 3.8, 3.9, or 4.0 and typically no greater than 4, 5, or 6. In some embodiments, the second aliphatic polyisocyanate may have a higher viscosity than the first polyisocyanate. In some embodiments, the second aliphatic polyisocyanate has a viscosity of at least 1,600; 1,700; 1,800; or 1,900 mPa- s at 23°C and typically no greater than 5,000; 4,500; 4,000; 3,500; or 3,000 mPa- s at 23°C, such as "DESMODUR XP 2599".

In this embodiment, the amount of first aliphatic polyisocyanate is typically at least 70, 75, or 80 wt.-% and in some embodiments at least 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95 wt.-% or greater of the first part. In this embodiment, the amount of second aliphatic polyisocyanate is typically at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 wt.-% or greater of the first part.

Various other mixtures of aliphatic polyisocyanates based on hexamethylene-1,6- diisocyanate (HDI) can be used. In some embodiments, the mixtures comprise three or four different polyisocyanates.

In some embodiments, the first part is substantially free of other "amine reactive resin(s)"

(i.e. a resin containing functional groups capable of reacting with primary or secondary amines). For example, the first part is typically free of aromatic amine reactive resins. The first part may also be free of epoxy functional compounds and compounds containing unsaturated carbon- carbon bonds capable of undergoing "Michael Addition" with polyamines (e.g. monomeric or oligomeric polyacrylates). The first part may optionally comprise non-reactive resins or the composition may be free of non-reactive resins.

The second part of the two-part coating comprises one or more polyamines. As used herein, polyamine refers to compounds having at least two amine groups, each containing at least one active hydrogen (N-H group) selected from primary amine or secondary amine. In some embodiments, the second component comprises or consists solely of one or more (e.g. secondary) polyamines.

In a preferred coating composition, as described herein the amine component comprises at least one aliphatic cyclic secondary polyamine (e.g. diamine). As described for example in US 6,005,062, aspartic ester amines react with isocyanates to form urea-diester linkages. However, urea-diester linkages are reportedly unstable, typically forming the hydantoin and an alcohol as a by-product. Hydantoin formation can cause dimensional changes of the polymer. Unlike aspartic ester amine, the amine component comprises at least one aliphatic cyclic secondary polyamine (e.g. diamine) that is not an aspartic ester amine. Therefore, such polyamine comprises secondary amine substituents, yet the polyamine lacks ester groups and specifically diester moieties.

In one embodiment, the second part comprises one or more aliphatic cyclic secondary diamines that comprise two, optionally substituted, hexyl groups bonded by a bridging group. Each of the hexyl rings comprise a secondary amine substituent.

The aliphatic cyclic secondary diamine typically has the general structure:

(Formula 1) wherein Ri and R₂ are independently linear or branched alkyl groups, having 1 to 10 carbon atoms. Ri and R₂ are typically the same alkyl group. Representative alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, tertiary butyl, and the various isomeric pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups. The symbol "S" in the center of the hexyl rings indicates that these cyclic groups are saturated. The preferred Ri and R₂ contain at least three carbons, and the butyl group is particularly favored, such as a sec -butyl group.

R₃, R₄, R5 and R₆ are independently hydrogen or a linear or branched alkyl group containing 1 to 5 carbon atoms. R₃, and R₄ are typically the same alkyl group. In some embodiments, R5 and R₆ are hydrogen. Further, in some embodiments, R₃, and R₄ are methyl or hydrogen.

The substituents are represented such that the alkylamino group may be placed anywhere on the ring relative to the CR5R6 group. Further, the R₃ and R₄ substituents may occupy any position relative to the alkylamino groups. In some embodiments, the alkylamino groups are at the 4,4'-positions relative to the CR5R6 bridge. Further, the R3 and R₄ substituents typically occupy the 3- and 3'-positions.

Commercially available aliphatic cyclic secondary diamines having this structure include:

In another embodiment, the second part comprises one or more aliphatic cyclic secondary diamines that comprise a single hexyl ring. The aliphatic cyclic secondary diamine typically has the general structure:

(Formula 2) wherein R7 and R₈ are independently linear or branched alkyl groups, having 1 to 10 carbon atoms or an alkylene group terminating with a -CN group. R7 and R₈ are typically the same group. Representative alkyl groups include the same as those described above for Ri and R₂. In one embodiment, R7 and R₈ are alkyl groups having at least three carbons, such as isopropyl. In another embodiment, R7 and R₈ are short chain (e.g. C1-C4) alkylene groups, such as ethylene, terminating with a -CN group. R9, Rio and Rn are independently hydrogen or a linear or branched alkyl group having 1 to 5 carbon atoms. R9, Rio and Rn are typically the same alkyl group. In some embodiments, R9, Rio and Rn are methyl or hydrogen. In one embodiment R9, Rio and Rn are methyl groups.

The substituents are represented such that the alkylamino group may be placed anywhere on the ring relative to the -NRs group. In some embodiments, the alkylamino group is 2 or 3 positions away from the -NR₈. The preferred alkylamine group is two positions away from the -NRs group on the cyclohexyl ring.

In some embodiments, the aliphatic cyclic secondary diamine is prepared by the reaction product of (1 equivalent of) isophorone diamine and (2 equivalents of) a Michael acceptor group that reduces the nucleophilicity of the resulting secondary amine groups. Representative Michael acceptors include acrylonitrile and α,β-unsaturated carbonyl compounds, with acrylonitrile typically preferred. In some embodiments, the alkylene group between the terminal -CN group and the amine group has at least two carbon atoms.

Commercially available aliphatic cyclic secondary polyamines (e.g. diamines) having this structure include:

In some embodiments, the isocyanate-reactive component of the second part may include a single aliphatic cyclic secondary diamine comprising two hexyl rings bonded by a bridging group, such as a species according to Formula 1. In some embodiments, the isocyanate-reactive component of the second part comprises two or more aliphatic cyclic secondary diamines comprising two hexyl rings bonded by a bridging group, such as two or more species according to Formula 1. In some embodiments, the isocyanate-reactive component of the second part may include a single aliphatic cyclic secondary diamine comprising a single hexyl ring, such as a species according to Formula 2. In some embodiments, the isocyanate-reactive component of the second part comprises two or more aliphatic cyclic secondary diamines comprising a single hexyl ring, such as two or more species according to Formula 2. In yet other embodiments, the isocyanate-reactive component of the second part may include at least one aliphatic cyclic secondary diamine comprising two hexyl rings bonded by a bridging group (e.g. a specie or species according to Formula 1) and at least one aliphatic cyclic secondary diamine comprising a single hexyl ring (e.g. a specie or species according to Formula 2).

In some embodiments, the second part typically comprises at least 20, 21, 22, 23, 24 or 25 wt.-% of aliphatic cyclic secondary polyamine(s) (e.g. diamine(s)). In some embodiments, the second part comprises at least 30, 35, 40, 45 or 50 wt.-% of aliphatic cyclic secondary

polyamine(s) (e.g. diamine(s)). The amount of aliphatic cyclic aliphatic cyclic secondary polyamine(s) (e.g. diamine(s)) can range up to 100%. However, in typical embodiments, the second part further comprises a polyether polyamine and filler(s). Thus, the amount of aliphatic cyclic secondary polyamine(s) (e.g. diamine(s)) is less than 100%. In some embodiments, the second part comprises up to 70, 75, 80, 85, 90, or 95 wt.-% of aliphatic cyclic secondary polyamine(s) (e.g. diamine(s)).

In typical embodiments, the liquid mixture of the first and second part further comprises a polyether component. In some embodiments, the polyether component may be an isocyanate functional polyether, such as DESMODUR XP 2599. The polyether component may also be an isocyanate-functional prepolymer, where an alcohol or amine functional polyether is added to a large molar excess of isocyanate compound. The polyether component may also be an amine- functional prepolymer, where an isocyanate functional polyether is added to a large molar excess of polyamine.

In typical embodiments, the polyether component comprises one or more amine functional polyethers, such as the JEFF AMINE series of polyether amines. Common types of amine functional polyethers include for example amine-terminated polypropylene oxide, amine- terminated polyethylene oxide (PEG), amine-terminated polytetramethylene oxide, etc.

The polyether amines may be either primary or secondary and are available in various molecular weights and functionality. In typical embodiments, the molecular weight is at least 100, 150, or 200 g/mol. In typical embodiments, the molecular weight is no greater than about 10,000; 9,000; 8,000; 7,000; 6,000 or 5,000 g/mol. Commercially available (e.g. primary and secondary) polyether amines include the following:

In some embodiments, the polyether component is amine functional polyether(s) or a combination of at least one isocyanate functional polyether and at least one amine functional polyether. In some embodiments, the first and/or second part comprises one or more polyether components such that the polyether content of the total composition (i.e. liquid mixture of first and second part) is at least 1, 1.5, 2, or 2.5 wt.-%. In some embodiments, the total polyether content is at least 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 8, 9.5 or 10 wt.-%. In other embodiments, the total polyether content is at least 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5 or 15 wt.-%. In some embodiments, the polyether content of the total composition (i.e. liquid mixture of first and second part) is preferably less than 25, 24, 23, 22 or 21 wt.-%. When the second part consists of aliphatic cyclic secondary diamine comprising a single hexyl ring, the concentration of polyether amine is typically no greater than 15, 14, 13, 12, 11, or 10 wt.-%.

The inclusion of one or more polyether components can increase the elongation while maintaining a calculated 50 year tensile creep rupture strength of at least 8, 9, or 10 MPa as described in US patent application serial no. 62/527508; incorporated herein by reference. As used herein, the calculated 50 year creep rupture strength refers to the value obtained according to the test method described in US patent application serial no. 62/527508. Such test method is believed to correspond with the value obtained when determining the 50 year creep rupture tensile strength according to ASTM D-2990-17, using the same sample conditioning method described in the examples and keeping the sample specimens saturated throughout the test. Thus, when a composition exhibits a calculated 50 year creep rupture tensile strength of at least 10 MPa according to such test method it will also exhibit a calculated 50 year creep rupture tensile strength of at least 10 MPa according to ASTM D-2990-17. The difference between the average values obtained by these methods is generally within the statistical standard deviation of such tests, meaning the average values are statistically the same.

In some embodiments, the calculated 50 year creep rupture tensile strength is at least 11, 12, 13, 14, 15, or 16 MPa. In typical embodiments, the calculated 50 year creep rupture tensile strength is no greater than 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, or 17 MPa. In some embodiments, the elongation is at least 4, 5, 6, or 7%. In typical embodiments, the elongation is no greater than 25% or 20% and in some embodiments, no greater than 19, 18, 17, 16 or 15%.

In some embodiments, the aliphatic cyclic secondary polyamine (e.g. diamine) is combined with one or more secondary aliphatic polyamine (including other cycloaliphatic polyamines) having a different structure than Formulas 1 and 2. The other secondary aliphatic polyamine may include aspartic acid ester, such as described in US2010/0266762; incorporated herein by reference. Preferred aspartic ester amines have the following formula:

FUOOC COOR 13

F OOC

COOR 13

(Formula 3) wherein R12 is a divalent organic group (up to 40 carbon atoms), and each R13 is independently an organic group inert toward isocyanate groups at temperatures of 100°C or less.

In the above formula, preferably, Ru is an aliphatic group (preferably, having 1-20 carbon atoms), which can be branched, unbranched, or cyclic. More preferably, R12 is selected from the group of divalent hydrocarbon groups obtained by the removal of the amino groups from 1,4- diaminobutane, 1,6-diaminohexane, 2,2,4- and 2,4,4-trimethyl-l,6-diaminohexane, 1-amino- 3,3,5-trimethyl-5-aminomethyl-cyclohexane, 4,4'-diamino-dicyclohexyl methane or 3,3- dimethyl-4,4'-diamino-dicyclohexyl methane.

In some embodiments, R12 preferably comprises a dicyclohexyl methane group or a branched C4 to C12 group. R13 is typically independently a lower alkyl group (having 1-4 carbon atoms).

Suitable aspartic acid esters are commercially available from Bayer Corp. under the trade designations "DESMOPHEN NH 1420", "DESMOPHEN NH 1520" and "DESMOPHEN NH 1220".

DESMOPHEN NH 1220 is substantially composed of the following compound Formula

4;

wherein Et is ethyl. (Formula 4)

The inclusion of aspartic acid esters according to Formula 3, wherein R is a branched or unbranched group lacking cyclic structures and having less than 12, 10, 8, or 6 carbon atoms, such as depicted in Formula 4, is typically preferred for faster film set times of 2 to 5 minutes. The inclusion of an aspartic acid ester according to Formula 3, wherein R¹² comprises unsubstituted cyclic structures can be employed to extend the film set time to 5 to 10 minutes. The inclusion of an aspartic acid ester according to Formula 3, wherein R¹² comprises substituted cyclic structures, (e.g. Formula ΠΙ of US 2010/0266764, can even further extend the film set time). Typically, such aspartic acid esters are employed at only small concentrations in combination with another aspartic acid ester that provides faster film set times, as just described.

In other embodiments, the second part may further comprise acyclic aliphatic linear or branched polyamines (i.e. that lacks a cyclic group).

One suitable commercially available aliphatic acyclic secondary diamine includes the following:

In some favored embodiments, the other aliphatic secondary diamine components are utilized at a lower concentration than the aliphatic cyclic secondary diamine (e.g. of Formula 1 and/or 2). Depending on the amount of aliphatic cyclic secondary diamine (e.g. of Formula 1 and/or 2) the concentration of such other aliphatic secondary diamine (e.g. aspartic ester amine) is typically no greater than 40, 35, 30, 25, 20, 15, 10 or 5 wt.-% of the polyamines of the second part or less than 25, 20, 15, 10, or 5 wt.-% of the total coating composition.

When present, the optional other amine components are chosen to dissolve in the liquid aliphatic cyclic secondary diamine (e.g. of Formula 1 and/or 2).

In some embodiments, the total composition (i.e. first and second part) is substantially free of aromatic components, such that the composition meets the NSF/ANSI Standard. In some embodiments, the total composition typically comprises less than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 or 0.5 wt.-% of aromatic components.

The average functionality (f_aVg) of the reactive components (e.g. polyisocyanates, polyamines, reactive silane compound etc.) of the total composition can be calculated using Equation 1, where Ni is the number of moles of a given reactant, and fi is the functionality of that reactant. The functionality of the reactant can be obtained by division of the molecular weight of the reactant by the equivalent weight of the reactant. It is appreciated that fillers (inclusive of pigments, thixotropes, and desiccants (i.e. molecular sieves or other solid drying agents described above), and other additives are not reactive components and are excluded for the calculation of

Equation 1. Calculation of average functionality

It has been found that increasing the average functionality can contribute to increasing the calculated 50 year creep rupture tensile strength. In some embodiments, the average

functionality is at least 2.30, 2.31, 2.32, 2.33, 2.34, 2.35, 2.36, 2.37, 2.38, 2.39, or 2.40. In other embodiments, the average functionality is at least 2.41, 2,42, 2.43, 2.44, 2.45, 2.46, 2.47, 2.48, 2.49, or 2.50. In typical, embodiments, the average functionality is less than 2.65, 2.64, 2.63, 2.62, 2.61, or 2.60.

In some embodiments, the above functionality is achieved utilizing one or more polyisocyantes each having a functionality greater than 2. However, the above functionality can also be achieved by utilizing a polyisocyanate having a functionality of 2 in combination with a second polyisocyante having a functionality greater than 2.

The first and/or second part may comprise various additives as are known in the art, provided the inclusion of such is permitted with the requirements of the NSF/ANSI Standard. For example, dispersing and grinding aids, defoamers, etc., can be added to improve the manufacturability, the properties during application, and/or the shelf life. The stoichiometry of the polyurea reaction is based on a ratio of equivalents of isocyanate (e.g. modified isocyanate and excess isocyanate) of the first component to equivalents of amine of the second component. The first and second components are reacted at a stoichiometric ratio of at least about 1 : 1.

Preferably, the isocyanate is employed in slight excess, such that the first part is combined with the second part at a ratio of 1.1 to 1.4 equivalents isocyanate to amine.

To simplify application in typical embodiments, the first and second part are formulated such that the stoichiometric ratio is obtained at a volume ratio of 1 : 1. However, other volume ratios can be employed, typically ranging from 1 :3 to 3:2. When the first and second part are combined at a particular volume ratio (e.g. 1 : 1) the weight percent of each of the components in the total coating composition (i.e. liquid mixture of first and second part) can be calculated based of the wt.-% of the part and the density of the component. Typical amounts of each of the components in the total coating composition are set forth in the following table. Other specific amounts can be derived from the wt.-% of the part as previously described and the density of a particular component as described in Table 1 of the examples.

The first and second parts are preferably each liquid at temperatures ranging from 5°C to 25°C, 30°C, 35°C, or 40°C. In view of the confined spaces within the pipeline and the resultant lack of suitable outlet for vapor, both the first part and the second part are substantially free of any volatile solvent. That is to say solidification of the system applied to the pipeline interior is not necessitated by drying or evaporation of solvent from either part of the system. To further lower the viscosity, one or both parts can be heated. Further, the coating composition has a useful shelf life of at least 6 months, more preferably, at least one year, and most preferably, at least two years.

Although a wide range of formulations are possible, such as exemplified in the forthcoming examples, the coating compositions described herein are particularly suitable for water distribution pipes, typically having a diameter > 3 inches (7.6 cm) up to about 36 inches (91 cm). It is generally desired that the cured coating has sufficient long term strength (i.e. 50 year creep rupture tensile strength) and ductility (i.e. flexibility as characterized by elongation at break) to remain continuous in the event of a subsequent circumferential fracture of a partially deteriorated (e.g. cast iron) pipe, such that the cured coating continues to provide a water impervious barrier between the flowing water and internal surfaces of the pipe. The following table describes typical and preferred properties of cured coating compositions for water distribution pipes as determined by the test methods described in US patent application serial no. 62/527508. Preferred Performance Ranges for Structural Coatings

The coating compositions described herein advantageously provide these desired properties while complying with NSF/ANSI Standard 61-2008, (i.e. the standard for the United States) and are also believed to comply with Regulation 31 of the Water Supply (Water Quality) Regulations (i.e. the standard for the United Kingdom).

The coating composition is typically applied directly to the internal surfaces of a pipe without a primer layer applied to the surface. This can be done using various spray coating techniques. Typically, the amine component and the isocyanate component are applied using a spraying apparatus that allows the components to combine immediately prior to exiting the apparatus. In carrying out the method of the invention, the first and second parts of the system are fed independently, e.g. by flexible hoses, to a spraying apparatus capable of being propelled through an existing pipeline to be renovated. For example, a remote-controlled vehicle, such as described in US 2006/0112996, may enter the pipeline to convey the spraying apparatus through the pipeline. The apparatus preferably heats the two parts of the system prior to application to the pipeline interior and mixes the two parts immediately before applying the mixture to the interior surface of the pipeline. The mixture of the two parts cures on the interior surface of the pipeline to form a (e.g. monolithic) water impervious lining. Such linings may be formed when the pipeline is initially laid, or after a period of use when the pipeline itself begins to deteriorate. Thus, the pipeline is typically buried underground at the time the coating composition is applied. The liquid mixture can be applied at various thickness. In some embodiments, the coating is present at a caliper ranging from about 1 to 15 mm. Multiple coating layers can be applied to obtain the desired caliper. Notably, the composition described herein can be applied at a caliper of at least 5 mm in a single pass forming a cured continuous lining.

A variety of spray systems may be employed as described in the art. In some

embodiments, a heated airless spray apparatus, such as a centrifugal spinning head is employed. In another embodiment, an airless, impingement mixing spray system is employed and generally includes the following components: a proportioning section which meters the two components and increases the pressure to above about 1500 psi (10.34 MPa); a heating section to raise the temperatures of the two components (preferably, independently) to control viscosity; and an impingement spray gun which combines the two components and allows mixing just prior to atomization. In other embodiments, the liquid mixture (e.g. coating composition) is heated and applied with an (e.g. air vortex) spray apparatus.

In some embodiments and in particular when the liquid mixture is applied by spraying, the first and second part typically each have a (Brookfield) viscosity ranging from about 5,000 centipoise (cps) to about 60,000 cps (using spindle 6 with a spindle speed of 20 revolutions per minute (RPM)) at the temperature at which the liquid mixture is applied. The temperature at which the liquid mixture is applied typically ranges from about 15°C to 50°C.

Viscosity behavior of each of the two components is important for two-part spray-coating processes. With impingement mixing, the two parts should be as close as possible in viscosity at high shear rates to allow adequate mixing and even cure. The plural component static mix/spray system appears to be more forgiving of viscosity differences between the two components.

Characterization of viscosities as functions of shear rate and temperature can help with decisions as to starting points for temperatures and pressures of the coatings in the two part spray equipment lines.

Advantages and embodiments of this disclosure are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention. In these examples, all percentages, proportions and ratios are by weight unless otherwise indicated. These abbreviations are used in the following examples: s = seconds, min = minute, ppb = part per billion, hr = hour, L = liter, mL = milliliter; wt = weight, gpm = gallons per minute, V = volts, cP = centipoise, MPa = megapascals, RPM = revolutions per minute, HP = horsepower, and Mw = molecular weight.

Materials and Methods

The chemicals used with their sources are shown in Table 1. All materials were obtained from commercial sources and used as received. Table 1. Raw materials and sources

NH1220 Aspartic ester, f=2 according to Formula I of 1.07 Covestro, US2010/0266764; Obtained under the trade Pittsburg, PA designation DESMOPHEN NH1220

MMOL A phthalate-free mixture of C10-C18 1.06 Laxness,

alkylsulphonic esters of phenol; Obtained under the Leverkusen, trade designation MESAMOLL Germany

CTS-720 Medium surface area fumed silica which has been 2.2 Cabot

surface modified with polydimethylsiloxane Corporation, (thixotrope); Obtained under the trade designation Bilerica, MA CAB-O-SIL TS-720

T595 Titanium dioxide pigment; Obtained under the 4.1 Cristal Global, trade designation TIONA 595 Australind,

WA

MH600 Dolomite (Ca/MgC03), calcium magnesium 2.85 Bentley

carbonate having 5.5 micron average size dolomite Chemicals, filler; Obtained under the trade designation Kidderminster, MICRODOL H600 Worcestershire,

UK

PURMOL Alkali aluminosilicate molecular sieve powder, 3 2.1 Zeochem,

Angstrom pore size; Obtained under the trade Louisville, KY designation PURMOL 3ST

BLUE A4R Phthalocyanine blue pigment; Obtained under the 1.61 Clariant,

trade designation PV FAST BLUE A4R Charlotte, NC

WC 10AS CaSi0₃, 3 micron average size aminosilane treated 2.9 Nyco Minerals, wollastonite, aspect ratio - 3: 1; Obtained under the Willsboro, NY trade designation 10 AS WOLLASTOCOAT

VS-W20 A calcium metasilicate or wollastonite (CaSi0₃), 2.9 Vanderbilt coarse powder grade with 2.5% retained on 325 Materials, mesh sieve; Obtained under the trade designation LLC, Norwalk, VANSIL W-20 CT VS-WG A long needle, high aspect ratio (Average Aspect 2.9 Vanderbilt Ratio = 15: 1), acicular grade of wollastonite; Materials, Obtained under the trade designation VANSIL WG LLC, Norwalk,

CT

VS-HR1500 A short needle, high aspect ratio (average aspect 2.9 Vanderbilt ratio = 14: 1), acicular grade of wollastonite; Materials, Obtained under the trade designation VANSIL HR- LLC, Norwalk, 1500 CT

F-SILICA 9-16 micron average size silica flour; Obtained 2.2 3M Company, under the trade designation FUSED SILICA 20 St. Paul, MN

HSB432 9 micron median particle size alumina trihydrate, 2.42 J.M. Huber

Al(OH)₃; Obtained under the trade designation Corporation, HYMOD SB 432 Edison, NJ

TM939-100 Aminosilane surface-treated wollastonite having 2.9 Quarzwerke mean aspect ratio of 7: 1, and in size of 95 um GmbH, (L90); Obtained under the trade designation Kaskadenweg TREMIN 939-100 40

50226 Frechen

TM939-300 Aminosilane surface-treated wollastonite having 2.9 Quarzwerke mean aspect ratio of 6: 1, and in size of 69 um GmbH, (L90); Obtained under the trade designation Kaskadenweg TREMIN 939-300 40

50226 Frechen

N-Si Aminosilane, (3-Aminopropyl) trimethoxysilane, 1.027 Sigma-Aldrich

H₂N(CH₂)₃Si(OMe)₃ Corporation,

St. Louis, MO

C8-Si Alkylsilane, Isooctyltriethoxysilane, Me₃C- 0.88 Gelest

CH₂CHMeCH₂-Si(OCH₃)₃ Corporation,

Morrisville, PA

C18-Si Alkylsilane, Trimethoxy(octadecyl)silane, CisH₃7- 0.883 Sigma-Aldrich

Si(OCH₃)₃ Corporation,

St. Louis, MO N-Si2 Aminosilane, Bis[3-(trimethoxysilyl) 1.04 Sigma-Aldrich propylamine, HN[(CH₂)₃Si(OMe)₃]2 Corporation,

St. Louis, MO

N2-Si2 Aminosilane, 0.89 Gelest,

(MeO)₃Si(CH2)₃NHCH₂CH₂NH(CH2)₃Si(OMe)₃ Morrisville, PA

N2-Si Aminosilane, 1.019 Gelest,

NH₂CH2CH2NHCH2CH2CH₂Si(OMe)₃ Morrisville, PA

N3-Si Aminosilane, 1.030 Gelest,

NH₂CH2CH2NHCH2CH2NHCH2CH2CH₂Si(OMe)₃ Morrisville, PA

NCO-Si Isocyanate-Silane, OCN(CH₂)₃Si(OMe)₃, 3- 1.073 Momentive,

(Triethoxysilyl)propyl isocyanate; Obtained under Waterford, NY the trade designation SILQUEST A-LINK 35

Ac-Si Acrylate-Silane, 3- 1.06 Gelest,

(Acryloxypropyl)trimethoxysilane, Morrisville, PA

CH₂=CHC0₂(CH₂)₃Si(OMe)₃

J754 Cycloaliphatic, bis (secondary amine), f = 2; 0.86 Huntsman obtained under the trade designation JEFFLINK Corporation, 754 The

Woodlands, TX

General method for preparation of resin mixtures

Two part cartridges were acquired: Sulzer Mixpac 1: 1 cartridges (Sulzer Mixpac

EAAC400-01-10-01, 400 milliliter (mL) 1 to 1 Cartridge Assembly Kit available from Ellsworth Adhesives, Germantown, WI) or Plas-Pak Industries Inc. 3:2 cartridges (Cartridge package 3:2 Ratio (150 x 100 mL), Norwich, CT).

Resin formulations were blended using a 3 horse power (HP), high dispersion Ross Mixer (Charles Ross and Son Company, St. Charles, IL) equipped with a vacuum attachment. Liquid formulation components were charged into a mixing vessel equipped with a Cowles mixing blade and vacuum was applied to the mixing vessel. The components mixed for 15 min at 1200 revolutions per minute (RPM). The first and second part (i.e., part A and part B) compositions were then loaded into opposite sides of two-part cartridges. All formulations utilized 1: 1 volume ratio unless specifically noted as 3:2. General method for preparation of molded samples

The cartridges were dispensed at 40°C using a pneumatic cartridge dispenser or mechanically driven cartridge dispensing system through a 32 element static mixer. A Sulzer Mixpac Static Mixer MCQ 08-32T was used for low viscosity materials, and a Sulzer Mixpac Static Mixer MCH 10-32T was used for materials containing CAB-O-SIL TS-720 (both mixers were obtained from Brandywine Materials, LLC, Burlington, MA). The materials were injected into a closed polytetrafluoroethylene (PTFE) mold (ASTM D638-08 Type IV dogbone, ~ 2 mm thickness for tensile tests, 120 mm x 10 mm x 4 mm rectangular samples for flexural testing). The parts were then demolded, and tags/molding excess on the samples were sanded smooth using 400 grit sandpaper.

Tensile Strength and Elongation Measurements Test Method 1

Molded dogbone samples were stored in a desiccator for greater than 7 days prior to testing. Samples for wet tensile strength were then soaked in deionized water for an additional 7 days prior to testing and measured immediately after removal from the water. Tensile strength and elongation were measured from the molded samples according to ASTM D-638-14 using a Sintech 10/D electromechanical load frame. Strain was measured by means of an extensometer with 25.4 mm gage length for both load frames, and the strain rate was 0.2 inches/minute (0.5 cm/minute). Test control and data acquisition was performed using TestWorks 4.0 software (MTS Corp., Eden Prairie, MN).

Tensile Strength Measurements Test Method 2

Molded dogbone samples were stored in a drybox for at least 2 days prior to testing. Samples for wet tensile strength (at least 6) from above were fully immersed in water in a glass jar, then sealed and aged in a 40°C oven for at least 7 days. Water absorption % was calculated based on the weight difference of dried samples and wet samples. The tensile samples were placed in fresh room temperature deionized water and further conditioned for at least 30 minutes. The wet samples were tested immediately after taking out from water.

Tensile strength was tested with an Instron (Norwood, MA) model 55R1122 universal load frame having fixed grips and a 5 kN load cell, at the testing speed of 2 inches/minute (5 cm/minute). Test control and data acquisition was performed using Bluehill software (Instron Corp., Norwood, MA). The reported data is the average of 6 tested specimens. Flexural Strength Test Method

Flexural strength and modulus were tested with Instron with a 5 kN load cell having support span of 64 mm and crosshead speed of 1.7 millimeters/minute (by ASTM D790-07) with Bluehill software to report the results.

Tensile Creep Test Method

The above molded 2 mm thick Type IV dogbone samples were allowed to condition for 7 days in a dessicator, then soaked in deionized water for at least 10 days at room temperature (20+2°C) to allow complete water saturation to simulate long-term conditions inside a water pipe. Before testing, the narrow portion of the dogbone was wrapped in a wet paper towel to keep samples saturated during the testing period, and the wet paper towel was taped over using 3M SCOTCH 3750 packaging tape to prevent cooling due to water evaporation. Creep rupture strength was determined by using an Instron model 55R1122 universal load frame to apply a fixed level of stress to a sample specimen, and time to failure (i.e. when the sample breaks) was recorded. The temperature during testing was 20+2°C. A minimum of five specimens per formulation were tested, with all five of such specimens failing in more than 0.1 hours, at least 3 samples failing in more than 1 hour, and at least one sample failing in more than 10 hours. The applied stress for each specimen was held constant, but differed from another specimen by at least 1 MPa. Samples with visible defects (such as bubbles and/or voids) were discarded. The measured values were plotted on a stress versus time plot and fit using a power function (i.e. y =mx^b , where y = applied stress and x = time to failure, and m and b are fitting parameters). The 50 year creep rupture tensile strength was extrapolated (i.e. calculated) from the fit and all R² values were greater than 0.85. An example of the fitting is shown in Table 2 below and in Fig. 3 for CE-1.

Table 2. Tensile creep test for CE- 1

Example preparation

All inventive examples (EX), control examples (CT), and comparative examples (CE) were generated using the general procedure described above. The values described are weight percent for each side of the two-part formulations. All formulations were dispensed using 1: 1 volume ratio of Part A: Part B (except for EX- 1 and EX-2, which were 1.5: 1 volume ratio of Part A:Part B).

Tables 3 - 6 list the weight percent values for the Part A and Part B compositions of the following examples

Table 3A. Formulations for Examples 1 to 7 (EX-1 to EX-7) Part A

Denotes 3:2 Part A to Part B volume ratio

Table 3B. Formulations for Examples 1 to 7 (EX-1 to EX-7) Part B

Denotes 3:2 Part A to Part B volume ratio Table 4A. Formulations for Examples 8 to 12, 14 (EX-8 to EX-12, EX-14) and Control 13 (CT-13) Part A

Table 4B. Formulations for Examples 8 to 12, 14 (EX-8 to EX-12, EX-14) and Control 13 (CT-13) Part B

Table 5A. Formulations for Examples 15 to 20, 22 (EX-15 to EX-20, EX-22) and Control 21 (CT-21) Part A

Table 5B. Formulations for Examples 15 to 20, 22 (EX-15 to EX-20, EX-22) and Control 21 (CT-21) Part B

Table 6A. Formulations for Controls 23 to 25 (CT-23 to CT-25) Part A

Table 6B. Formulations for Controls 23 to 25 (CT-23 to CT-25) Part B

Tables 7 - 10 list the weight percent values (volume percent values in parenthesis) for the total compositions of the followins examples (liquid mixture of Part A and Part B)

Table 7. Total composition formulations for Examples 1 to 7 (EX-1 to EX-7)

Table 8. Total composition formulations for Examples 8 to 12, 14 (EX-1 to EX-12, EX-14) and Control 13 (CT-13)

Table 9. Total composition formulations for Examples 15 to 20, 22 (EX- 15 to EX-20, EX- 22) and Control 21 (CT-21)

Table 10. Total composition formulations for Controls 23 to 25 (CT-23 to CT-25)

Tables 11 - 13 list the tensile properties of the following examples

Table 11.* Tensile properties of wet and dry samples with various fillers. Filler loading approximately 15% v/v, silane to filler wt. ratio 1.5%.

Dry Wet Dry Wet Dry Wet Dry Δ Wet A

EX-1** None None 38.1 33.6 9.3 10.0 1710 1580 0 0

EX-2** None N-Si 36.4 34.3 16+ 12.1 1570 1560

-1.7 0.7

EX-3 MH600 None 29.2 23.4 5.2 9.1 2710 2210 -8.9 -10.2

EX-4 MH600 N-Si 37.3 30.8 5.1 5.1 2630 2450 -0.8 -2.8

EX-5 WC 10AS Factory 43.3 37.3 4.4 5.3 3370 3170

applied N- 5.2 3.7 Si

EX-6 VS-W20 None 39.1 29.4 2.4 3.1 4000 3950 1 -4.2

EX-7 VS-W20 N-Si 42.2 39.1 7.1 4.7 3620 3660 4.1 5.5

EX-8 F-SILICA None 34.2 25.8 2.2 4.3 2810 2750 -3.9 -7.8

EX-9 F-SILICA N-Si 38.5 37.1 7.8 7.8 2620 2590 0.4 3.5

EX- 10 HSB432 None 35.4 24.4 2.6 5.7 2650 2310

-2.7 -9.2

EX- 11 HSB432 N-Si 38.3 28.0 3.0 4.7 2560 2330 0.2 -5.6

EX- 12 VS-W20 N-Si2 45.0 39.1 4.8 5.1 3670 3280 6.9 5.5

CT-13 VS-W20 C18-Si 31.9 27.2 3.3 5.1 3700 3540 -6.2 -6.4

EX- 14 VS-W20 NCO-Si 41.9 38.6 3.4 4.5 3550 3610 3.8 5

*Tensile strength, elongation percent, and Y-modulus (Young's Modulus) measurements were taken using the Tensile Strength and Elongation Measurements Test Method 1 described above;

**EX-1 and EX-2 were dispensed using a 1.5: 1 volume ratio of Part A:Part B. ***Several samples exceeded the 20% strain limit of the extensometer.

Table 12.* Tensile properties of some high and low aspect ratio fillers, approximately 10 volume % loading.

Example Filler Aspect Silane Silane Tensile

Ratio Treatment /filler wt. Strength,

ratio MPa

Dry Wet

EX- 15 VS-W20 < 5: 1 None 0 45 41

EX- 16 VS-W20 < 5: 1 N-Si 5% 51 51

EX- 17 VS-HR1500 14: 1 None 0 55 43 EX- 18 VS-HR1500 14: 1 N-Si 1.5% 65 57

EX- 19 VS-HR1500 14: 1 N-Si 2.5% 63 58

EX-20 VS-HR1500 14: 1 N-Si 5% 58 56

CT-21 VS-HR1500 14: 1 C18-Si 5% 45 40

*Tensile strength measurements were taken using the Tensile Strength Measurements Test Method 2 described above.

Table 13.* Tensile properties of silane treated and non-treated fillers.

*Tensile strength measurements were taken using the Tensile Strength and Elongation Measurements Test Method 1 described above.

Tables 14 - 17 list the weight percent values for the Part A and Part B compositions of the following examples

Table 14A. Formulations for Examples with aminosilane surface-treated woUastonite filler having aspect ratios of 7:1 and 6:1 - Control 26 and Examples 27 to 28 (CT-26, EX-27 to EX-28) Part A

Table 14B. Formulations for Examples with aminosilane surface-treated woUastonite filler having aspect ratios of 7:1 and 6:1 - Control 26 and Examples 27 to 28 (CT-26, EX-27 to EX-28) Part B

Table 15A. Formulations for Examples with reactive silane and non-reactive silane - Examples Control 29 (CT-29) and Examples 30 to 33 (EX-30 to EX-33) Part A

Table 15B. Formulations for Examples with reactive silane and non-reactive silane - Control 29 (CT-29) and Examples 30 to 33 (EX-30 to EX-33) Part B

Table 16A. Formulations for Examples with a combination of reactive silanes - Examples 34, 35, and 37 (EX-34, EX-35, and EX-37) and Control 36 (CT-36) Part A

MATERIAL EX-34 EX-35 CT-36 EX-37

N3600 57.76 63.44 78.03 77.19

MMOLL 12.22 12.13 VS-HR1500 27.14 22.30 21.97 21.73

Ac-Si 2.88

NCO-Si 2.33 1.08

Table 16B. Formulations for Examples with a combination of reactive silanes - Examples 34, 35, and 37 (EX-34, EX-35, and EX-37) and Control 36 (CT-36) Part B

Table 17A. Formulation for Examples with either aminosilane N2-Si2 or N-Si2 - Examples 39 and 40 (EX-39 and EX-40) and Control 38 (CT-38) Part A

Table 17B. Formulation for Examples with either aminosilane N2-Si2 or N-Si2 - Examples 39 and 40 (EX-39 and EX-40) and Control 38 (CT-38) Part B

Tables 18 and 19 list the weight percent values (volume percent values in parenthesis) for the total compositions of the following examples (liquid mixture of Part A and Part B) Table 18. Total composition formulations for Examples 27, 28, and 30 to 33 (EX-27, EX-28, and EX-30 to EX-33) and Controls 26 and 29 (CT-26 and CT-29)

Table 19. Total composition formulations for Examples 34, 35, 37, 39, 40 (EX-34, EX-35, EX-37, EX-39 and EX-40) and Control 36 and 38 (CT-36 and CT-38)

MATERIAL EX-34 EX-35 CT-36 EX-37 CT-38 EX-39 EX-40

N3600 30.6 34.35 42.6 42.1 35.16 34.72 34.72

(33.9) (35.92) (44.9) (44.3) (36.99) (36.45) (36.45) MMOLL 6.5 6.57

(7.9) (7.59)

XP2599 11.71 11.57 11.57

(13.75) (13.55) (13.55)

VS-HR1500 31.1 24.04 23.9 23.6

(13.8) (10.06) (10.1) (10.0)

VS-WG 24.98 24.67 24.67

(10.36) (10.51) (10.36)

Ac-Si 1.5

(1.9)

NCO-Si 1.20 0.6

(1.47) (0.7)

CL1000 22.2 25.12 28.8 28.5 28.16 27.81 27.81

(32.1) (34.33) (39.6) (39.0) (38.75) (38.18) (38.18)

JT-5000 6.6 7.51

(8.5) (9.21)

NH1220 4.7 4.6

(5.4) (5.3)

N-Si 1.6 0.6

(1.9) (0.7)

N3-Si 1.20

(1.42)

N2-Si2 1.23

(1.46)

N-Si2 1.23

(1.46)

Table 20 lists the tensile properties of the followins examples Table 20.* Tensile properties of wet and dry samples with filler and water adsorption

CT-26 None 45 38 2.58

EX-27 T939-100(N- Filler Pretreated 53 45 1.53

Si)/7.5

EX-28 T939-300(N- Filler Pretreated 53 46 1.61

Si)/7.5

CT-29 VS-HR1500 None 55 42 2.11

EX-30 VS-HR1500 / 10 N-Si and 57 54 1.28

C8-Si

EX-31 VS-HR1500 / 10 N-Si and 54 54 1.45

C8-Si

EX-32 VS-HR1500 / 10 N-Si and 56 55 1.38

C8-Si

EX-33 VS-HR1500 / 15 N-Si and 55 53 1.22

NCO-Si

EX-34 VS-HR1500 / 15 N-Si and 59 56 1.08

Ac-Si

EX-35 VS-HR1500 / 15 N3-Si and 54 50 1.48

NCO-Si

CT-36 VS-HR1500 / 10 None 61 55 1.99

EX-37 VS-HR1500 / 10 N-Si and 60 58 1.72

NCO-Si

CT-38 VS-WG / 10 None 53 45 1.72

EX-39 VS-WG / 10 N2-Si2 53 52 1.47

EX-40 VS-WG / 10 N-Si2 56 52 1.54

*Tensile strength measurements were taken using the Tensile Strength Measurements Test Method 2 described above

Tables 21 A and B list the weight percent values for the Part A and Part B compositions of the following examples

Table 21A. Formulation for Controls 41 and 45 (CT-41 and CT-45) and Examples 42 to 44, 46, and 47 (EX-42 to EX-44, EX-46, and EX-47) Part A

MMOLL 16.80 12.14 12.14 12.14 16.80 13.95 10.30

VS-W20 28.90

VS-WG 28.90

VS-HR1500 28.90 16.99 38.70

Table 21B. Formulation for Controls 41 and 45 (CT-41 and CT-45) and Examples 42 to 44, 46, and 47 (EX-42 to EX-44, EX-46, and EX-47) Part B

Table 22 lists the weight percent values (volume percent values in parenthesis) for the total compositions of the following examples (liquid mixture of Part A and Part B)

Tables 22. Total composition formulations for Controls 41 and 45 (CT-41 and CT-45) and Examples 42 to 44, 46, and 47 (EX-42 to EX-44, EX-46, and EX-47)

VS-W20 33.11

(15.02)

VS-WG 33.11

(15.02)

VS-HR1500 33.11 18.51 41.20

(15.02) (7.50) (20.01)

Table 23 lists the tensile properties of the following examples

Table 23.* Tensile properties of wet and dry samples with filler and water adsorption

Table 24. Representative flexure properties from selected formulations

Claims

What is claimed is:

1. A method of forming a coating on a surface of a pipeline, the method comprising the steps of: a) providing a polyurea coating composition comprising

a first part comprising at least one polyisocyanate, and

a second part comprising at least one polyamine; and

b) combining the first part and the second part to form a liquid mixture wherein the first part, second part, or liquid mixture further comprises

cl) at least one inorganic filler and at least one silane compound comprising a functional group that is reactive with the first or second part; or

c2) a siliceous filler having an aspect ratio of at least 2: 1; and

d) applying the liquid mixture to internal surfaces of the pipeline; and

e) allowing the mixture to set forming a cured coating.

2. The method of claim 1 wherein the polyurea coating composition is provided with the filler(s) and silane compound(s) contained within the first and/or second part.

3. The method of claim 1 wherein the polyurea coating composition is provided with the filler(s) contained within the first and second part and the silane compound(s) contained within the second part.

4. The method of claim 1 wherein the polyurea coating composition is provided with the filler(s) contained within the first and/or second part and the silane compound(s) added to the first and/or second part prior to combining the first and second part or during combining the first part and the second part.

5. The method of claim 1 wherein the polyurea coating composition is provided without the filler(s) and without the silane compound(s), and the filler(s) and silane compound(s) are added to the first and/or second part prior to combining the first and second part or during combining the first part and the second part.

6. The method of claims 1-5 wherein the filler comprises at least 25 wt.-% silica.

7. The method of claim 6 wherein the filler comprises CaSi0₃.

8. The method of claims 1-7 wherein the filler has an aspect ratio of at least 2: l, 3: 1 4: l, or 5: l.

9. The method of claims 1-8 wherein the filler is present in an amount of 1, 2, 3, 4, or 5 vol.-% of the total composition.

10. The method of claims 1-8 wherein the functional group of the silane is selected from amine, isocyanate, or (meth)acrylate.

11. The method of claims 1-10 wherein the second part comprises one or more of the aliphatic cyclic secondary diamine(s) in an amount ranging from 20 wt.-% to 100 wt.-% of the polyamines of the second part.

12. The method of claim 11 wherein the aliphatic cyclic diamines(s) are not aspartic ester amines or the second part further comprises up to 20 wt-% of aspartic ester amines.

13. The method of claims 11-12 wherein the second part comprises an aliphatic cyclic secondary diamine comprising two hexyl rings bonded by a bridging group.

14. The method of claim 13 wherein the aliphatic cyclic secondary diamine has the general formula:

wherein Ri and R₂ are independently alkyl groups, having 1 to 10 carbon atoms and R₃, R₄, Rs and R₆ are independently hydrogen or alkyl groups having 1 to 5 carbon atoms.

15. The method of claim 14 wherein Ri and R₂ are independently alkyl groups comprising at least 2 carbon atoms, R₃ and R₄ are methyl or hydrogen, and R5 and R₆ are hydrogen.

16. The method of claims 1-15 wherein the polyisocyanate is aliphatic.

17. The method of claim 16 wherein the polyisocyanate is a derivative of hexamethylene diisocyanate, a derivative of isophorone diisocyanate, a derivative of hexamethylene diisocyanate and isophorone diisocyanate, or a mixture thereof.

18. The method of claims 1-17 wherein the liquid mixture is applied at a caliper of at least 5 mm in a single pass.

19. The method of claims 1-18 wherein the liquid mixture has a polyether content of at least 2.5 wt.-%.

20. The method of claim 19 wherein the polyether content is derived at least in part from a polyether polyamine, a polyisocyanate or a combination thereof.

21. The method of claims 1-20 wherein the pipeline is a drinking water pipeline and the cured coating contacts drinking water.

22. A method of improving the wet tensile strength of a polyurea coating composition comprising:

a) providing a polyurea coating composition comprising

a first part comprising at least one polyisocyanate, and

a second part comprising at least one polyamine; and

c2) a siliceous filler having an aspect ratio of at least 2: 1; and

d) applying the liquid mixture to a surface; and

e) allowing the mixture to set forming a cured coating.

23. The method of claim 22 wherein the coating composition is further characterized by any one or combination of claims 2-21.

24. A polyurea coating composition comprising:

a) a first part comprising at least one polyisocyanate,

b) a second part comprising at least one polyamine,

an optional third part,

wherein the total polyurea coating composition comprises at least 5% by volume of the total composition of filler and a silane compound comprising a functional group that is reactive with the first or second part.

25. A polyurea coating composition comprising:

a) a first part comprising at least one polyisocyanate,

b) a second part comprising at least one polyamine,

an optional third part,

wherein the total polyurea coating composition comprises at least 5% by volume of the total composition of siliceous filler having an aspect ratio of at least 2: 1, 3: 1, 4: 1, or 5: 1.

26. The polyurea coating composition of claim 25 wherein the coating composition further comprises a silane compound comprising a functional group that is reactive with the first or second part.

27. The polyurea coating composition of claim 25-26 wherein the coating composition is further characterized by any one or combination of claims 7 and 11-21.

28. An article comprising a surface wherein at least a portion of the surface is submerged in water during ordinary use wherein the surface comprising a layer of a cured polyurea coating composition according to claims 24-27.

29. The article of claim 28 wherein the article is a pipeline and the surface is the internal surfaces of the pipeline.