WO2014209832A1

WO2014209832A1 - Article with silanol coating and method of making

Info

Publication number: WO2014209832A1
Application number: PCT/US2014/043566
Authority: WO
Inventors: Jitendra S. Rathore; Suresh S. Iyer; Chetan P. Jariwala; Vijay Rajamani
Original assignee: 3M Innovative Properties Company
Priority date: 2013-06-28
Filing date: 2014-06-23
Publication date: 2014-12-31

Abstract

Articles having silanol coatings and methods of making the articles are provided. More specifically, articles include a substrate and a coating attached to a major surface of the substrate. The silanol coating includes an aminosilanol polymer that is a reaction product of water and an aminosilane. The silanol coating adheres to but is not covalently bonded to the substrate. If desired, the silanol coating can be removed from the article by dissolution in water. The silanol coating can be provided on a large variety of substrates and tends to provide improved resistant to fogging.

Description

ARTICLE WITH SILANOL COATING AND METHOD OF MAKING

Field

Articles with silanol coatings and methods of making the articles are provided.

Background

Anti-fog coatings are used in high humidity areas where water vapors easily condense, for example, on eye glasses, bathroom mirrors, inside surfaces of car windshields, etc. One common method to prevent fogging is the use of polymer mirrors or heated elements installed behind conventional glass mirrors. Physically heating the glass electronically can make the glass defog quickly. Air conditioning can also make the glass defog, for instance, as commonly employed to defog automobile glass. Such physical methods show excellent anti-fog results, yet

simultaneously dramatically increase energy consumption and cost. Additionally, various coatable compositions are available. These coatable compositions, however, typically require some sort of curing mechanism (e.g., catalytic curing, radiation curing, or thermal curing) to yield solid coatings, which makes them inconvenient for consumer applications. Summary

Articles with silanol coatings and methods of making the articles are provided. More specifically, the articles include a substrate and a silanol coating disposed on a major surface of the substrate. The silanol coatings adhere to the surface of the substrate but are not covalently bonded to the substrate. That is, the silanol coatings adhere without curing and can be removed by dissolution in water, if desired. The silanol coatings provide anti-fogging characteristics to the articles.

In a first aspect, an article is provided that includes (a) a substrate and (b) a silanol coating attached to a major surface of the substrate. The silanol coating is not covalently bonded to the substrate. The silanol coating contains an aminosilanol polymer that is a reaction product of water and an aminosilane of Formula (I).

(I)

In Formula (I), each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl. The group R² is a divalent group comprising an alkylene, arylene, -N(R⁵)-, or a combination thereof. The group R³ is a hydrolyzable group and the group R⁴ is a non-hydrolyzable group. The group R⁵ is hydrogen or alkyl. The variable x is equal to 2 or 3.

In a second aspect, a method of making an article is provided. The method includes providing a substrate and applying a coatable composition to a major surface of the substrate. The coatable composition contains an aminosilanol polymer that is a reaction product of water and an aminosilane of Formula (I).

(I)

In Formula (I), each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl. The group R² is a divalent group comprising an alkylene, arylene, -N(R⁵)-, or a combination thereof. The group R³ is a hydrolyzable group and the group R⁴ is a non-hydrolyzable group. The group R⁵ is hydrogen or alkyl. The variable x is equal to 2 or 3. The method further includes forming a silanol coating, wherein the silanol coating is not covalently bonded to the substrate.

The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list.

Brief Description of the Drawings

Figure 1 is an exemplary schematic of an article including a substrate and a silanol coating.

While the above-identified drawing, which may not be drawn to scale, sets forth an embodiment of the present disclosure, other embodiments are also contemplated, as noted in the Detailed Description.

Detailed Description

Articles with silanol coatings and methods of making the articles are provided. More specifically, the articles include a substrate and a silanol coating disposed on a major surface of the substrate. The silanol coating adheres to but is not covalently bonded to the substrate. The silanol coating includes an aminosilanol polymer that is a reaction product of water and an aminosilane. The silanol coating tends to improve the resistance of the resulting article to fogging.

The recitation of any numerical range by endpoints is meant to include the endpoints of the range, all numbers within the range, and any narrower range within the stated range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.8, 4, and 5). Unless otherwise indicated, all numbers expressing quantities or ingredients, measurement of properties and so forth used in the specification and embodiments are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached listing of embodiments can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings of the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claimed embodiments, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

For the following Glossary of defined terms, these definitions shall be applied for the entire application, unless a different definition is provided in the claims or elsewhere in the specification.

Definitions

Certain terms are used throughout the description and the claims that, while for the most part are well known, may require some explanation. It should be understood that, as used herein:

The term "a", "an", and "the" are used interchangeably with "at least one" to mean one or more of the elements being described.

The term "and/or" means either or both. For example, the expression "A and/or B" means A, B, or a combination of A and B.

The terms "comprises" and variations thereof do not have a limiting meaning where these terms appear in the description and claims.

The words "preferred" and "preferably" refer to embodiments of the disclosure that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure.

The term "coatable composition" refers to a solution or dispersion including components (e.g., an aminosilane, an aminosilanol polymer, surfactant, water, water-miscible organic solvents, fillers, additives, and the like) that are suitable for applying onto a major surface of a substrate as a coating.

The term "fluid layer" refers to a coatable composition that has been applied onto a surface, for example onto a major surface of a substrate, prior to being subjected to a drying process. The term "silanol coating" refers to the components remaining after application of a coatable composition onto a major surface of a substrate and drying (e.g., removing at least the majority of water, water-miscible organic solvent, or both) the coatable composition.

The term "aminosilane" refers to a molecule having an amino group (i.e., a primary amino group, secondary amino group, or tertiary amino group) and a silyl group that is hydrolyzable.

The term "aminosilanol polymer" refers to the reaction product of three or more aminosilane compounds with water. The aminosilanol polymer has multiple -O-Si-0- linkages. The number of linkages can be at least 2, at least 3, at least 10, at least 20, at least 50, at least 100, or even more. The aminosilanol polymer is typically soluble in water, in a water-miscible organic solvent, or both.

The term "adjacent" in reference to a coating (e.g., the silanol coating) being adjacent to a substrate, means that the coating can contact a surface of the substrate or can be separated from a surface of the substrate by one or more other coatings.

The term "not covalently bonded" in reference to a silanol coating being attached to a substrate, means that the silanol coating can be attached to (e.g., adhere to) the substrate by any forces (e.g., electrostatic interaction, hydrogen bonding, van der Waals forces, etc.) except by formation of a covalent bonds between molecule on the substrate surface and the silanol coating.

The term "alkyl" refers to a monovalent group that is a radical of an alkane. The alkyl group can have 1 to 20 carbon atoms and can be linear, branched, cyclic, or a combination thereof. When the alkyl is linear, it can have 1 to 20 carbon atoms. When the alkyl is branched or cyclic, it can have 3 to 20 carbon atoms.

The term "alkylene" refers to a divalent group that is a radical of an alkane. The alkylene group can have 1 to 20 carbon atoms and can be linear, branched, cyclic, or a combination thereof. When the alkylene is linear, it can have 1 to 20 carbon atoms. When the alkylene is branched or cyclic, it can have 3 to 20 carbon atoms.

The term "alkoxy" refers to refers to a monovalent group having an oxy group bonded directly to an alkyl group.

The term "aryl" refers to a monovalent group that is a radical of an aromatic carbocyclic compound. The aryl group has at least one aromatic carbocyclic ring and can have 1 to 5 optional rings that are connected to or fused to the aromatic carbocyclic ring. The additional rings can be aromatic, aliphatic, or a combination thereof. The aryl group usually has 5 to 20 carbon atoms.

The term "arylene" refers to a divalent group that is a radical of an aromatic carbocyclic compound. The arylene group has at least one aromatic carbocyclic ring and can have 1 to 5 optional rings that are connected to or fused to the aromatic carbocyclic ring. The additional rings can be aromatic, aliphatic, or a combination thereof. The arylene group usually has 5 to 20 carbon atoms.

The term "alkaryl" refers to an aryl group substituted with at least one alkyl group. The alkaryl group contains 6 to 40 carbon atoms. The alkaryl group often contains an aryl group having 5 to 20 carbon atoms and an alkyl group having 1 to 20 carbon atoms.

The term "aralkyl" refers to an alkyl group substituted with at least one aryl group. The aralkyl group contains 6 to 40 carbon atoms. The aralkyl group often contains an alkyl group having 1 to 20 carbon atoms and an aryl group having 5 to 20 carbon atoms.

The term "aralkylene" refers to a divalent group that is an alkylene group substituted with an aryl group or an alkylene group attached to an arylene group. Aralkylene groups often have an alkylene portion with 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms and an aryl or arylene portion with 6 to 20 carbon atoms, 6 to 18 carbon atoms, 6 to 16 carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms.

The term "aryloxy" refers to a monovalent group having an oxy group bonded directly to an aryl group.

The term "aralkyloxy" refers to a monovalent group having an oxy group bonded directly to an aralkyl group. Equivalently, it can be considered to be an alkoxy group substituted with an aryl group.

The term "acyloxy" refers to a monovalent group of formula -0(CO)R^b where R^b is alkyl, aryl, or aralkyl. Suitable alkyl R^b groups often have 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Suitable aryl R^b groups often have 6 to 12 carbon atoms such as, for example, phenyl. Suitable aralkyl R^b groups often have an alkyl group with 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms that is substituted with an aryl having 6 to 12 carbon atoms such as, for example, phenyl.

The term "halo" refers to a halogen atom such as fluoro, bromo, iodo, or chloro. When part of a reactive silyl, the halo group is often chloro

The term "silyl" refers to a monovalent group of formula -Si(R³)_x(R⁴)₃__x having at least two hydro lyzable groups R³ and up to 1 hydro lyzable group R⁴. The variable x is equal to 2 or 3. In some embodiments, the silyl group is of formula -Si(R³)₂(R⁴) or -Si(R³)₃.

The term "hydrolyzable group" refers to a group that can react with water having a pH of

1 to 10 under conditions of atmospheric pressure. The hydrolyzable group is often converted to a hydroxyl group when it reacts. The hydroxyl group often undergoes further reactions. Typical hydrolyzable groups include, but are not limited to, alkoxy, aryloxy, aralkyloxy, acyloxy, or halo. As used herein, the term is often used in reference to one of more groups bonded to a silicon atom in a silyl group. The term "non-hydrolyzable group" refers to a group that cannot react with water having a pH of 1 to 10 under conditions of atmospheric pressure. Typical non-hydrolyzable groups include, but are not limited to alkyl, aryl, alkaryl, and aralkyl. As used herein, the term is often used in reference to one of more groups bonded to a silicon atom in a silyl group.

Articles and Methods of Making the Articles

(I)

The aminosilane can have a primary amino group (i.e., both R¹ groups in Formula (I) are hydrogen), a secondary amino group (i.e., one R¹ group is hydrogen ant the other R¹ group is alkyl, aryl, alkaryl, or aralkyl), or a tertiary amino group (i.e., both of the R¹ groups in Formula (I) are alkyl or aryl).

The group R² is often an alkylene or two or more alkylene groups connected to a -N (Regroup. Suitable alkylene groups often have 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 3 carbon atoms. The group R⁵ is often hydrogen.

Suitable silyl groups have either two or three hydrolyzable R³ groups. Suitable hydrolyzable groups include alkoxy, aryloxy, aralkyloxy, acyloxy, or halo groups. In many embodiments, the hydrolyzable group is an alkoxy or halo group. Some example alkoxy groups have 1 to 6 carbon atoms, 1 to 3 carbon atoms, or 1 to 2 carbon atoms (i.e., methoxy and ethoxy). The halo group is often chloro. If there are two hydrolyzable groups, then there is a single non- hydrolyzable group R⁴. Suitable non-hydrolyzable groups include alkyl, aryl, alkaryl, and aralkyl groups. When mixed with water, the hydrolyzable R³ groups are typically converted to hydroxyl groups. In many embodiments, the non-hydrolyzable group is an alkyl such as an alkyl having 1 to 6 carbon atoms, 1 to 3 carbon atoms, or 1 or two carbon atoms (i.e., methyl or ethyl).

Some aminosilanes of Formula (I) are of Formula (la).

N(R¹)₂-(R⁶-NH)_p-CH₂CH₂CH₂-Si(R³)_x(R⁴)₃-_x

(la) Group -(R⁶-NH)_p-CH₂CH₂- in Formula (la) is equal to group -R²- in Formula (I). In Formula (la), groups R¹, R³, and R⁴ are defined as in Formula (I). Group R is an alkylene, arylene, aralkylene, -N(R⁵)-, or a combination thereof.

Where p is equal to one in Formula (la), the aminosilane can have two or more amino groups. In many embodiments, the amino group N(R^!)₂- is a primary or secondary amino group. These compounds can be represented by Formula (lb).

(lb)

The groups R¹, R⁶, R³, and R⁴ are the same as defined above for Formula (la).

Some more specific examples include compounds of Formula (lb) where R⁶ is an alkylene having 1 to 6 carbon atoms, 1 to 3 carbon atoms, or 1 to 2 carbon atoms. In these more specific compounds, some exemplary silyl groups include trimethoxysilyl, triethoxysilyl,

methyldimethoxysilyl, methyldiethoxysilyl. Some even more specific example compounds of Formula (lb) include, but are not limited to, aminoethylaminopropyltrimethoxysilane,

aminoethylaminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and benzylaminoethylaminopropyltrimethoxysilane.

When p is equal to zero in Formula (la), the aminosilane has a single amino group. The amino group N(R^!)₂- is often a primary or secondary amino group. These compounds can be represented by Formula (Ic).

(Ic)

The amino group is separated from the silyl group by three carbon atoms.

Some exemplary compounds of Formula (Ic) have a silyl group such as trimethoxysilyl, triethoxysilyl, methyldimethoxysilyl, methyldiethoxysilyl. Some example compounds of Formula (Ic) include, but are not limited to, aminopropyltrimethoxysilane and aminopropyltriethoxysilane.

When the aminosilanes are mixed with water, the hydrolyzable R³ group typically is converted to a hydroxyl group. Thus, the aminosilanes of Formula (I) become aminosilanol compounds of Formula (II).

N(RVR²-CH₂-Si(OH)_x(R⁴)₃__x

(II)

In Formula (II), the groups R¹, R², R⁴ and the variable x are the same as defined for Formula (I). Some aminosilanol compounds are of Formula (Ila), Formula (lib), or Formula (lie) corresponding to those formed from the aminosilanes of Formula (la), Formula (lb), or Formula (Ic) respectively.

N(R -(R⁶-NH)_p-CH₂CH₂CH₂-Si(Oli R _x

(Ila) NH(R R⁶-NH-CH₂CH₂CH₂-Si(OH)_x(R⁴}

(lib)

NH(R CH₂CH₂CH₂-Si(OH)_x(R⁴)₃__x

(lie)

At least some of these aminosilanols can undergo hydrogen bonding between the amino group and the silanol group as shown below in Formula (lie- 1 ) for the aminosilanols of Formula (He) with the resulting formation of a ring-like structure.

(IIc-1)

In Formula (lie- 1), group R⁷ is equal to -OH when x is equal to 3 and is equal to R⁴when x is equal to 2. The hydrogen on the amino group -NHR can hydrogen bond with the silanol group -Si(OH)₂R⁷.

The aminosilanols can react, however, in water to form an aminosilanol polymer by a condensation reaction. This reaction is usually exothermic. The condensation reaction results in the formation of multiple -O-Si-0- linkages. The aminosilanol polymer has at least 2 -O-Si-0- linkages but often has at least 5, at least 10 linkages, at least 20 linkages, at least 50 linkages, at least 100 linkages, or at least 200 linkages. The aminosilanol polymer resulting from the reaction of multiple aminosilanols of Formula (II) can be of Formula (III). The variable q is equal to at least 1 but is often equal to at least 2, at least 3, at least 5, at least 10, at least 20, at least 50, at least 100, at least 200, or even greater.

(III)

In Formula (III), group R⁷ is equal to hydroxyl when x is equal to 3 and is equal to R⁴when x is equal to 2. When R⁷ is a hydroxyl group, the aminosilanol units can undergo hydrogen bonding between the -SiOH group and the amino group of formula -IS^R¹)^ Alternatively, the -SiOH group can form a crosslink with another polymeric unit of Formula (III). The amount of aminosilane of Formula (I) added to water to form the aminosilanol polymer of Formula (III) is typically at least 0.1 weight percent based on a total weight of the coatable composition (e.g., the mixture of water and aminosilane). In some embodiments, the amount of aminosilane is at least 0.5 weight percent, at least 1 weight percent, at least 2 weight percent, at least 3 weight percent, at least 5 weight percent, or at least 10 weight percent. The amount of the aminosilane can be up to 50 weight percent or higher depending on the solubility of the aminosilane in the water and the viscosity of the resulting mixture. In some embodiments, the amount of aminosilane is up to 40 weight percent, up to 30 weight percent, up to 25 weight percent, or up to 20 weight percent. In some example coatable compositions, the amount of aminosilane is in a range of 0.1 to 50 weight percent, in a range of 1 to 50 weight percent, in a range of 1 to 40 weight percent, in a range of 1 to 30 weight percent, or in a range of 1 to 20 weight percent.

The aminosilanol polymer of Formula (III) is typically soluble in water. The coatable composition used to apply the aminosilanol polymer to a surface of the substrate can include the aminosilanol polymer and water. In some embodiments, no other components are added to the coatable composition. In other embodiments, however, other components such as a non-ionic surfactant, a water-miscible organic solvent (i.e., a co-solvent), a filler, tetraethylorthosilicate (TEOS), or the like can be added to the coatable composition.

In order to uniformly coat the substrate or to enhance the interfacial adhesion of a coatable composition onto a hydrophobic substrate, it may be desirable to reduce the surface tension of the coatable composition. In certain embodiments, the coatable composition used to form a silanol coating contains a non-ionic surfactant, or more than one non-ionic surfactant. The presence of a non-ionic surfactant typically improves wetting of a substrate (e.g., a hydrophobic substrate) when the coatable composition is applied to a major surface of a substrate.

Any suitable non- ionic surfactant can be used. Example non- ionic surfactants include, but are not limited to, an alkyl ethoxylate, an ethylene oxide/propylene oxide block copolymer, an alkyl polyglycoside, a linear secondary alcohol ethoxylate, a branched secondary alcohol ethoxylate, an alkylphenol ethylene oxide condensate, an ethyleneoxide-propyleneoxide-ethylene oxide triblock based copolymer, an alkyl polyglucoside, or a combination thereof. Suitable non- ionic surfactants are available under the trade designation TERGOTOL TMN- 10 surfactant (i.e., a branched secondary alcohol ethoxylate), and TRITON X- 100 surfactant (i.e., an octylphenol ethoxylate) commercially available from The Dow Chemical Company (Midland, MI).

The non-ionic surfactant is often used in an amount in a range of 0.01 to 10 weight percent based on the total weight of the coatable composition. In some embodiments, the amount of non- ionic surfactant is present in an amount equal to at least 0.05 weight percent, at least 0.1 weight percent, or at least 1 weight percent. The amount of the non-ionic surfactant can be up to 8 weight percent, at least 0.01 to 7 weight percent, or 0.01 to 4 weight percent, 0.1 to 7 weight percent, or 0.1 to 4 weight percent of the total coatable composition.

In certain embodiments, the coatable composition contains a polar co-solvent (i.e., a water-miscible organic solvent), or more than one polar co-solvent, in addition to water. Suitable co-solvents include for example and without limitation, alcohols such as ethanol, isopropyl alcohol, n-butanol, n-propanol, and iso-butyl alcohol; ethers such as a glycol ether (e.g., diethylene glycol dimethyl ether), 1 ,4-dioxane, and tert-butyl methyl ether; ketones such as diethyl ketone, methyl ethyl ketone, acetone, and methyl iso-butyl ketone; esters such as ethyl acetate, propylene carbonate, and 2-methoxyethyl acetate; and halogenated solvents such as chloroform. Any desired amount of the co-solvent can be included in the coatable composition. In some embodiments, the water in the reaction mixture used to form the aminosilanol polymer is at least partially replaced in the coatable composition by a water-miscible organic solvent that may dry at a lower temperature. In some embodiments, the coatable composition can include 1 to 90 weight percent water-miscible organic solvent based on a total weight of the coatable composition. The amount of water- miscible organic solvent is often in a range of 1 to 70 weight percent, 1 to 50 weight percent, 1 to 20 weight percent, or 1 to 10 weight percent, or 30 to 70 weight percent, or 50 to 90 weight percent of the total coatable composition.

The coatable composition optionally includes additional components such as

tetraethylorthosilicate (TEOS). TEOS can improve adhesion of the silanol coating to the substrate.

The TEOS can be present in an amount of 0 to 10 weight percent. If present, the amount of TEOS can be in a range of 0.01 to 10 weight percent, in a range of 0.01 to 5 weight percent, in a range of 0.01 to 1 weight percent, in a range of 1 to 10 weight percent, or in a range of 1 to 5 weight percent based on the total weight of the coatable composition.

The coatable composition optionally can further include at least one filler such as silica particles, alumina particles, zirconia particles, or combinations thereof. When added, the coatable composition can contain up to 20 weight percent, up to 15 weight percent, up to 10 weight percent, or up to 5 weight percent filler based on the total weight of solids in the coatable composition. In some embodiments, the coatable compositions contain 1 to 20 weight percent, 1 to 10 weight percent, or 1 to 5 weight percent filler.

The coatable composition is applied to a substrate to prepare articles having a silanol coating. Suitable substrates comprise glass, ceramic material, polymeric material such as polyethylene terephthalate (PET) or polycarbonate, metals such as aluminum, chromium, iron, nickel, titanium, or the like, or a combination thereof. The substrate may be flat, curved or shaped. The substrate can be flexible or rigid, transparent or opaque, and colored or clear. Typically the substrate is in the form of a film, sheet, panel or pane of material, or molded material, and may be a part of an article such as motor vehicle window and windshield, mirror, eye glasses, helmet visor, face shield, building window or door, solar panel, architectural glazing, and decorative glass frame. The silanol coatings may, if desired, cover only a portion of the substrate.

In some embodiments, where increased transmissivity is desired, the substrate is transparent. The term "transparent" means transmitting at least 85 percent of incident light in the visible spectrum (about 400-700 nm wavelength). Transparent substrates may be colored or colorless.

As stated above, an article is provided that includes (a) a substrate and (b) a silanol coating attached or adhered to a major surface of the substrate. The silanol coating is not covalently bonded to the substrate. Accordingly, the silanol coating can be attached to the substrate by any forces (e.g., electrostatic interaction, hydrogen bonding, van der Waals forces, etc.) except by covalent bonds between molecules on the substrate surface and molecules in the silanol coating. This is in contrast to the use of aminosilane molecules in primer layers, in which the aminosilane molecules form covalent bonds with molecules on the substrate surface, thereby enhancing adhesion between the substrate and any additional coatings disposed on the primer layer.

Advantageously, the formation of the dried silanol coating does not require any curing catalyst or radiation. The strength of adhesion of the silanol coating to a substrate can be evaluated, for example, using the Tape Peel Test described in the Examples.

In most embodiments, the silanol coating attached to a major surface of the substrate is dry. That is, the majority of the water or water-miscible organic solvent in the coatable composition has been removed. As used herein, the term "dry silanol coating" or references to the silanol coating being dry means that the silanol coating contains no greater than 5 weight percent, no greater than 2 weight percent, no greater than 1 weight percent water, or no greater than 0.5 weight percent water based on the weight of the silanol coating. The dry silanol coating is formed by removing water, the water miscible solvent, or a combination thereof from the fluid layer of the coatable composition that is applied to the substrate.

The dry silanol coating typically can be redissolved in water, a water-miscible organic solvent, or a mixture thereof at room temperature (e.g., 20°C to 25°C) or near room temperature. That is, the dried silanol coating is either not crosslinked or is so lightly crosslinked so that it can be removed by dissolution. In many embodiments, the silanol coating is soluble in water at room temperature or near room temperature. This easy removal process may be desirable if the silanol coating needs to be replaced.

The silanol coatings typically impart anti-fog properties to substrates coated therewith. Coatings are considered anti-fogging if a coated substrate resists the formation of small, condensed water droplets in sufficient density to significantly reduce the transparency of the coated substrate such that it cannot be adequately viewed through by the human eye after exposure to repeated human breath directly on the article and/or after holding the article above a source of steam. A coating may still be regarded as anti-fogging even though a uniform water film or a small number of large water droplets forms on the coated substrate so long as the transparency of the coated substrate is not significantly reduced such that it cannot be readily seen through. In many instances, a film of water that does not significantly reduce the transparency of the substrate will remain after the substrate has been exposed to a steam source. There are numerous instances where the value of optically clear articles would be enhanced if the tendency of the articles to cause light scattering or glare or to be obscured by the formation of a fog on a surface of the article could be reduced. For example, motor vehicle windows and windshields, architectural glazings, eyeglasses, face shields, building windows, and decorative glass frames, may all scatter light in a manner that causes an annoying and disruptive glare. Use of such articles may also be

detrimentally affected by the formation of a moisture vapor fog on a surface of the article. Ideally, in preferred embodiments, the coated articles of this invention have exceptional anti-fog properties while also separately having greater than 90 percent transmission of 550 nm light.

Unexpectedly, in embodiments the (dried) silanol coating can remain adhered (e.g., the article passes the Tape Peel Test) to the substrate even upon exposure to water vapor. More specifically, the coating can be subjected to air comprising 100 percent humidity at 20°C for 24 hours without any detectable decrease in the tape peel adhesion value of the silanol coating to the substrate, as compared to tape peel adhesion value immediately prior the subjection to the air comprising 100% humidity at 20°C. In certain embodiments, the coating can be subjected to air comprising 100% humidity at 20°C for 48 hours, or 72 hours, or 96 hours without any detectable decrease in the tape peel adhesion value of the silanol coating to the substrate, as compared to tape peel adhesion value immediately prior the subjection to the air comprising 100% humidity at 20°C.

Figure 1 provides an exemplary schematic of an article 10 according to certain

embodiments of the disclosure. The article 10 includes a substrate 12 and a silanol coating 14 attached to a major surface of the substrate 12.

The optimal average thickness of the silanol coating is usually dependent upon the particular coatable composition used. The thickness can be varied by varying the thickness of the fluid layer of the coatable composition applied to the substrate. In general, average thickness of the (dry) silanol coating is in the range of 100 to 10,000 angstroms (A), in the range of 500 to 2500 A, in the range of 750 to 2000 A, or in the range of 1000 to 1500 A. The thickness can be measured using an ellipsometer such as a Gaertner Scientific Corp. Model No. LI 15C. The dry silanol coating often contains at least 50 weight percent of the aminosilanol polymer. For example, the silanol coating can contain at least 60 weight percent, at least 70 weight percent, at least 80 weight percent, or at least 90 weight percent aminosilane polymer. The amount of the aminosilanol polymer in the silanol coating can be up to 99.5 weight percent, up to 95 weight percent, up to 90 weight percent, up to 80 weight percent, or up to 60 weight percent. In some embodiments, the silanol coating contains the aminosilanol polymer in an amount in a range of 50 to 99.5 weight percent, in a range of 50 to 85 weight percent, in a range of 50 to 75 weight percent, in a range of 50 to 60 weight percent, in a range of 75 to 99.5 weight percent, or in a range of 60 to 80 weight percent. The weight percents are based on the total weight of the dry silanol coating.

The dry silanol coating often contains 0 to 20 weight percent, 0.01 to 20 weight percent, 0.05 to 20 weight percent, 0.1 to 20 weight percent, 0.5 to 20 weight percent, 0.1 to 10 weight percent, or 0.1 to 5 weight percent non-ionic surfactant based on the total weight of the silanol coating.

The dry silanol coating often contains 0 to 10 weight percent, 0.1 to 10 weight percent, 0.1 to 5 weight percent, 0.1 to 3 weight percent, 0.1 to 2 weight percent, or 0.1 to 1 weight percent TEOS based on the total weight of the silanol coating.

The dry silanol coating often contains 0 to 20 weight percent, 0.5 to 15 weight percent, 1 to 10 weight percent, or 1 to 5 weight percent filler based on the total weight of the silanol coating.

(I)

To form the article having the silanol coating, the coatable composition is applied to the substrate as a fluid layer using conventional techniques, for example and without limitation, wipe coating, bar coating, roll coating, curtain coating, rotogravure coating, knife coating, spray coating, spin coating, or dip coating, of the composition on the major surface of the substrate. The wet thickness of the fluid layer (i.e., coatable composition applied to the substrate), for example, can be in the range of 0.1 to 100 micrometers, in the range of 0.1 to 50 micrometers, or in the range of 0.1 to 10 micrometers. Although the actual fluid layer thickness can vary considerably from one particular point to another, it is often desirable to apply the coatable composition uniformly over the surface of the substrate. For example, to minimize visible interference color variations in the final coating, it may be desirable to control the average coating thickness of the fluid layer within 200 A, within 150 A, or within 100 A across the substrate.

A silanol coating is formed from the fluid layer by drying. Drying can be accomplished via one or more various routes. Typically, the drying method includes allowing the composition applied to the substrate (e.g., fluid layer) to dry under ambient conditions, thereby forming a silanol coating as the water (and optional water-miscible organic solvent) evaporates. In certain embodiments the drying method comprises wiping the fluid layer applied to the substrate (e.g., wiping with a cloth), thereby removing liquid within the fluid layer. To speed the drying process, in certain embodiments the fluid layer is dried at a temperature of 25°C to 100°C, thereby forming the silanol coating. An oven with circulating air or inert gas such as nitrogen is often used for such heated drying purposes.

The silanol coating resulting from drying the fluid layer on the substrate according to methods of the invention typically can be removed by dissolution in water, a water-miscible organic solvent, or a mixture thereof. In certain embodiments, the method further includes washing the silanol coating off the major surface of the substrate with water. Moreover, such a method preferably further includes applying at least a second portion of the coatable composition as a fluid layer to the major surface of the substrate, following removal of the coating. Due to the ease of application and removal of the coating, a substrate can be coated with a portion of the composition once, twice, three times, four times, or any number of times. An advantage of embodiments of the present disclosure, therefore, is that although the silanol coating has anti-fog properties and significant adhesion to a substrate, the silanol coating is easily washed off of the substrate and optionally replaced with a new coating, if needed or desired. The simplicity of the method of preparing the article, which does not require specialized equipment, allows a consumer or other user to conveniently apply a coatable composition onto a substrate and form a coating, as well as to remove and replace the coating with a new coating in the event a fresh coating is desired.

The coatable compositions, fluid layers, silanol coatings, and substrate materials described above are suitable for use in the method of preparing the article.

Various items are described that are articles or methods of making articles. Item 1 is an article including (a) a substrate; and (b) a silanol coating attached to a major surface of the substrate. The silanol coating is not covalently bonded to the substrate. The silanol coating includes an aminosilanol polymer that is a reaction product of water and an aminosilane of Formula (I)

(I)

wherein

each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R² is a divalent group comprising an alkylene, arylene, -N(R⁵)-, or a combination thereof;

R³ is a hydrolyzable group;

R⁴ is a non-hydrolyzable group;

R⁵ is hydrogen or alkyl; and

x is equal to 2 or 3.

Item 2 is an article of item 1 , wherein the silanol coating further includes a non- ionic surfactant.

Item 3 is an article of item 1 or item 2, wherein the aminosilane is of Formula (la)

N(R¹)₂-(R⁶-NH)_p-CH₂CH₂CH₂-Si(R³)_x(R⁴)₃-_x

(la)

wherein

each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R⁶ is a divalent group comprising an alkylene, arylene, aralkylene, -N(R⁵)- , or a combination thereof;

R³ is a hydrolyzable group;

R⁴ is a non-hydrolyzable group;

R⁵ is hydrogen or alkyl;

p is equal to 0 or 1 ; and

x is 2 or 3.

Item 4 is an article of item 3, wherein p is equal to 0 and each R¹ is hydrogen or alkyl. Item 5 is an article of item 3, wherein p is equal to 1, each R¹ is hydrogen or alkyl, and R⁶ is alkylene.

Item 6 is an article of item 1 or item 2, wherein the aminosilane is of Formula (lb)

NH(R¹)-R⁶-NH-CH₂CH₂CH₂-Si(R³)_x(R⁴)₃._x

(lb)

wherein each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R³ is a hydrolyzable group;

R⁴ is a non-hydrolyzable group; and

x is equal to 2 or 3.

Item 7 is an article of item 6, wherein the aminosilane includes

aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, N-(2- aminoethyl)-3-aminopropylmethyldimethoxysilane, or

benzylaminoethylaminopropyltrimethoxysilane.

Item 8 is an article of item 1 or item 2, wherein the aminosilane is of Formula (Ic)

NH(R CH₂CH₂CH₂-Si(R³)_x(R⁴)₃-_x

(Ic)

wherein

R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R³ is a hydrolyzable group;

R⁴ is a non-hydrolyzable group; and

x is equal to 2 or 3.

Item 9 is an article of item 8, wherein the aminosilane includes

aminopropyltrimethoxysilane or aminopropyltriethoxysilane.

Item 10 is an article of any one of items 1 to 9, wherein the silanol coating includes at least 50 weight percent aminosilanol polymer based on a total weight of the silanol coating.

Item 1 1 is an article of any one of items 1 to 10, wherein the silanol coating further includes at least one filler comprising silica particles, alumina particles, zirconia particles, or combinations thereof.

Item 12 is an article of any one of items 1 to 1 1, wherein the silanol coating further includes tetraethylorthosilicate (TEOS).

Item 13 is an article of any one of items 1 to 12, wherein the silanol coating can be removed by dissolution in water.

Item 14 is an article of any one of items 1 to 13, wherein the silanol coating can be subjected to air comprising 100% humidity at 20°C for 24 hours without any detectable decrease in the tape peel adhesion value of the coating to the substrate, as compared to tape peel adhesion value immediately prior the subjection to the air comprising 100% humidity at 20°C.

Item 15 is an article of item 2, wherein the surfactant includes an alkyl ethoxylate, an ethylene oxide/propylene oxide block copolymer, an alkyl polyglycoside, a linear secondary alcohol ethoxylate, a branched secondary alcohol ethoxylate, an alkylphenol ethylene oxide condensate, or a combination thereof.

Item 16 is an article of any one of items 1 to 15, wherein the substrate includes glass, a polymeric material, a metal, or a combination thereof.

Item 17 is an article of any one of items 1 to 16, wherein the aminosilanol polymer includes at least five -O-Si-0- linkages.

Item 18 is a method for coating an article, the method including (a) providing a substrate; (b) applying a coatable composition to a major surface of the substrate, the coatable composition containing an aminosilanol polymer that is a reaction product of water and an aminosilane of Formula (I)

(I)

wherein

each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R³ is a hydrolyzable group;

R⁴ is a non-hydrolyzable group;

R⁵ is hydrogen or alkyl;

x is 2 or 3; and

(c) forming a silanol coating, wherein the silanol coating is not covalently bonded to the substrate.

Item 19 is a method of item 18, wherein the aminosilane is of Formula (la)

N(R¹)₂-(R⁶-NH)_p-CH₂CH₂CH₂-Si(R³)_x(R⁴)₃-_x

(la)

wherein

each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R³ is a hydrolyzable group;

R⁴ is a non-hydrolyzable group;

R⁵ is hydrogen or alkyl;

p is equal to 0 or 1 ; and

x is 2 or 3.

Item 20 is a method of item 19, wherein p is equal to 0 and each R¹ is hydrogen or alkyl. Item 21 is a method of item 20, wherein p is equal to 1 , each R¹ is hydrogen or alkyl, and R⁶ is alkylene.

Item 22 is a method of item 18, wherein the aminosilane is of Formula (lb)

NHCR^-R^NH-CHzCHzCHz-SiCR^_xCR _x

(lb)

wherein

each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R³ is a hydro lyzable group;

R⁴ is a non-hydrolyzable group; and

x is equal to 2 or 3.

Item 23 is a method of item 22, wherein the aminosilane includes

benzylaminoethylaminopropyltrimethoxysilane.

Item 24 is a method of item 18, wherein the aminosilane is of Formula (Ic)

NH(R CH₂CH₂CH₂-Si(R³)_x(R⁴)₃-_x

(Ic)

wherein

R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R³ is a hydrolyzable group;

R⁴ is a non-hydrolyzable group; and

x is equal to 2 or 3.

Item 25 is a method of item 24, wherein the aminosilane includes

aminopropyltrimethoxysilane or aminopropyltriethoxysilane.

Item 26 is a method of any one of items 18 to 25, wherein the silanol coating includes at least 50 weight percent aminosilanol polymer based on a total weight of the silanol coating.

Item 27 is a method of any one of items 18 to 26, wherein the aminosilanol polymer includes at least five -O-Si-0- linkages.

Item 28 is a method of any one of items 18 to 27, wherein the method further includes drying the coatable composition at a temperature of 25°C to 100°C after applying the coatable composition to the substrate.

Item 29 is a method of any one of items 18 to 28, wherein the method further includes wiping the coatable composition after applying the coatable composition to the substrate. Item 30 is a method of any one of items 18 to 29, wherein applying the coatable composition to the substrate includes wipe coating, bar coating, roll coating, curtain coating, rotogravure coating, knife coating, spray coating, spin coating, or dip coating the coatable composition on the major surface of the substrate.

Item 31 is a method of any one of items 18 to 30, wherein the coatable composition further includes a non-ionic surfactant.

Item 32 is a method of any one of items 18 to 31 , wherein the silanol coating further includes tetraethylorthosilicate (TEOS).

Item 33 is a method of any one of items 18 to 32, wherein the silanol coating further includes at least one filler comprising silica particles, alumina particles, zirconia particles, or combinations thereof.

Item 34 is a method of any one of items 18 to 33, wherein the silanol coating can be subjected to air comprising 100% humidity at 20°C for 24 hours without any detectable decrease in the tape peel adhesion value of the coating to the substrate, as compared to tape peel adhesion value immediately prior the subjection to the air comprising 100% humidity at 20°C.

Item 35 is a method of item 31, wherein the surfactant includes an alkyl ethoxylate, an ethylene oxide/propylene oxide block copolymer, an alkyl polyglycoside, a linear secondary alcohol ethoxylate, a branched secondary alcohol ethoxylate, an alkylphenol ethylene oxide condensate, or a combination thereof.

Item 36 is a method of any one of items 18 to 35, wherein the silanol coating can be removed by dissolution in water.

Item 37 is a method of any one of items 18 to 36, wherein the substrate includes glass, a polymeric material, a metal, or a combination thereof.

Item 38 is a method of any one of items 18 to 37, wherein the coatable composition further contains a co-solvent including ethanol, isopropyl alcohol, n-butanol, n-propanol, iso-butyl alcohol, diethylene glycol dimethyl ether, 1 ,4-dioxane, tert-butyl methyl ether, diethyl ketone, methyl ethyl ketone, acetone, methyl iso-butyl ketone, ethyl acetate, propylene carbonate, 2- methoxyethyl acetate, or chloroform.

EXAMPLES

Objects and advantages of this invention 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. These examples are merely for illustrative purposes only and are not meant to be limiting on the scope of the appended claims. Materials

Unless otherwise noted, all parts, percentages, ratios, etc., in the examples and in the remainder of the specification are by weight. Unless otherwise noted, all chemicals were obtained from, or are available from, chemical suppliers such as Sigma- Aldrich Chemical Company, St. Louis, MO.

Test Methods

Method for Tape Peel Test

This test was run to determine the quality of adhesion of the silanol coatings according to the Examples and Comparative Examples described below on to their respective substrates. SCOTCH 610 tape was applied as firmly as possible onto the top surface of the coated samples. Then, the tape was rapidly peeled off from the surface at a 90-degree angle. If the coating did not peel off, the coated sample was rated "pass". If the coating peeled off with the tape, the sample was rated "fail".

Method for Anti-Fog Test

The anti-fog performance of the samples prepared according to the Examples and

Comparative Examples were determined by subjecting them to water vapors by breathing out air directly onto the coated substrate and then visually examining the surfaces. Based on the visual examination, the anti-fog performance of each sample was determined and the samples were assigned an anti-fog performance rating. The criteria used for determining the anti-fog performance and anti-fog performance rating for the samples is described in Table 1 , below.

Table 1 : Criteria for Anti-Fog Test

Examples 1-18 (EX1-EX18) and Comparative Example A (CE-A)

To prepare EX1 anti-fog coating formulation, 5 g of AS- 1 was added dropwise to 95 g of distilled water while constantly stirring during the addition. The addition of aforementioned aminosilane (i.e., AS- 1) resulted in exothermic hydrolization of alkoxy groups into silanol groups, thus forming oligomers. Thereafter, 0.25 g of SURF- l was added to the solution as a surfactant.

CE-A was prepared in the same manner as EX1, except that 5 g of AS-6 was used instead of AS- 1.

EX2-EX18 were prepared in the same manner as EX1 by except that the type and amount of the aminosilane, water and the surfactant were varied as summarized in Table 2, below. Table 2: Coatable Compositions

The anti-fog coating solution of EX1 prepared above was applied onto a 5 cm X 5 cm (2- inch X 2-inch) glass substrate using a paper towel soaked in the coating solution (coatable composition). Thereafter, the excess solution was wiped off and dried with a clean paper towel. A thin layer of solid adherent coating (silanol coating) was formed upon evaporation of the solvent. The same coating method was used for coating a variety of different substrates (e.g., polyethylene terephthalate (PET), polycarbonate, and aluminum) for each of EX1-EX18. The tape peel test and anti-fog performances were determined using the methods described above. Table 3 summarizes the data for each sample.

For CE-A, the coating was applied as described above for EX1 but, evaporation of solvent yielded a wet coating that could be easily be wiped off with a clean paper towel leaving the substrate without a coating. Table 3: Characteristics of the Silanol Coatings

EX12 Glass 1 Pass Dried

EX12 PET 1 Pass Dried

EX12 Polycarbonate 1 Pass Dried

EX12 aluminum 1 Pass Dried

EX13 Glass 1 Pass Dried

EX13 PET 1 Pass Dried

EX13 Polycarbonate 1 Pass Dried

EX13 aluminum 1 Pass Dried

EX14 Glass 1 Pass Dried

EX14 PET 1 Pass Dried

EX14 Polycarbonate 1 Pass Dried

EX14 aluminum 1 Pass Dried

EX15 Glass 1 Pass Dried

EX15 PET 1 Pass Dried

EX15 Polycarbonate 1 Pass Dried

EX15 aluminum 1 Pass Dried

EX16 Glass 1 Pass Dried

EX16 PET 1 Pass Dried

EX16 Polycarbonate 1 Pass Dried

EX16 aluminum 1 Pass Dried

EX17 Glass 1 Pass Dried

EX17 PET 1 Pass Dried

EX17 Polycarbonate 1 Pass Dried

EX17 aluminum 1 Pass Dried

EX18 Glass 1 Pass Dried

EX18 PET 1 Pass Dried

EX18 Polycarbonate 1 Pass Dried

EX18 aluminum 1 Pass Dried

CE-A Glass 3 Failed Wet

CE-A PET 3 Failed Wet

CE-A Polycarbonate 3 Failed Wet

CE-A aluminum 3 Failed Wet

Claims

What is claimed is:

An article comprising:

a. a substrate; and

b. a silanol coating attached to a major surface of the substrate, wherein the silanol coating is not covalently bonded to the substrate, the silanol coating comprising an aminosilanol polymer that is a reaction product of water and an aminosilane of Formula (I)

(I)

wherein

each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R³ is a hydro lyzable group;

R⁴ is a non-hydrolyzable group;

R⁵ is hydrogen or alkyl; and

x is equal to 2 or 3.

2. The article of claim 1, wherein the silanol coating further comprises a non- ionic surfactant.

3. The article of claim 1 or 2, wherein the aminosilane is of Formula (la)

N(R¹)₂-(R⁶-NH)_p-CH₂CH₂CH₂-Si(R³)_x(R⁴)₃-_x

(la)

wherein

each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R³ is a hydrolyzable group;

R⁴ is a non-hydrolyzable group;

R⁵ is hydrogen or alkyl;

p is equal to 0 or 1 ; and

x is 2 or 3.

4. The article of claim 3, wherein p is equal to 0 and each R¹ is hydrogen or alkyl.

5. The article of claim 3, wherein p is equal to 1, each R¹ is hydrogen or alkyl, and R⁶ is alkylene.

6. The article of any one of claims 1 to 5, wherein the silanol coating comprises at least 50 weight percent aminosilanol polymer based on a total weight of the silanol coating.

7. The article of any one of claims 1 to 6, wherein the silanol coating further comprises at least one filler comprising silica particles, alumina particles, zirconia particles, or combinations thereof.

8. The article of any one of claims 1 to 7, wherein the silanol coating further comprises tetraethylorthosilicate (TEOS).

9. The article of any one of claims 1 to 8, wherein the silanol coating can be removed by dissolution in water.

10. The article of any one of claims 1 to 9, wherein the silanol coating can be subjected to air comprising 100% humidity at 20°C for 24 hours without any detectable decrease in the tape peel adhesion value of the coating to the substrate, as compared to tape peel adhesion value immediately prior the subjection to the air comprising 100% humidity at 20°C.

1 1. A method for coating an article, the method comprising:

providing a substrate;

applying a coatable composition to a major surface of the substrate, the coatable composition comprising an aminosilanol polymer that is a reaction product of water and an aminosilane of Formula (I)

(I)

wherein

each R¹ is hydrogen, alkyl, aryl, alkaryl, or aralkyl;

R³ is a hydrolyzable group;

R⁴ is a non-hydrolyzable group; R⁵ is hydrogen or alkyl;

x is 2 or 3; and

forming a silanol coating, wherein the silanol coating is not covalently bonded to the substrate.

12. The method of claim 1 1, wherein the method further comprises drying the coatable

composition at a temperature of 25°C to 100°C after applying the coatable composition to the substrate.

13. The method of claim 1 1, wherein the method further comprises wiping the coatable

composition after applying the coatable composition to the substrate.

14. The method of any one of claims 1 1 to 13, wherein applying the coatable composition to the substrate includes wipe coating, bar coating, roll coating, curtain coating, rotogravure coating, knife coating, spray coating, spin coating, or dip coating the coatable composition on the major surface of the substrate.

15. The method of any one of claims 1 1 to 14,wherein the coatable composition further

comprises a non- ionic surfactant.

16. The method of any one of claims 1 1 to 15, wherein the silanol coating can be removed by dissolution in water.

17. The method of any one of claims 1 1 to 16, wherein the substrate comprises glass, a

polymeric material, a metal, or a combination thereof.

18. The method of any one of claims 1 1 to 17, wherein the coatable composition further comprises a co-solvent comprising ethanol, isopropyl alcohol, n-butanol, n-propanol, iso- butyl alcohol, diethylene glycol dimethyl ether, 1,4-dioxane, tert-butyl methyl ether, diethyl ketone, methyl ethyl ketone, acetone, methyl iso-butyl ketone, ethyl acetate, propylene carbonate, 2-methoxyethyl acetate, or chloroform.