U.S. patent application number 09/803280 was filed with the patent office on 2001-08-30 for capped silicone film and method of manufacture thereof.
Invention is credited to Hayden, Don.
Application Number | 20010018130 09/803280 |
Document ID | / |
Family ID | 22680022 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010018130 |
Kind Code |
A1 |
Hayden, Don |
August 30, 2001 |
Capped silicone film and method of manufacture thereof
Abstract
A silicone film is attached to a surface by chemical bonding.
The silicone film consists of chains of siloxane groups, each chain
terminating in an end molecule which is either an ester, an ether,
or a halogen. The end molecule is allowed to react with water to
produce an OH group. The surface is then contacted with a capping
agent which reacts with the OH group to produce a new end group
which improves the properties of the film.
Inventors: |
Hayden, Don; (Los Gatos,
CA) |
Correspondence
Address: |
Richard L. Myers
100 Pacifica, Suite 210
Irvine
CA
92618
US
|
Family ID: |
22680022 |
Appl. No.: |
09/803280 |
Filed: |
March 9, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09803280 |
Mar 9, 2001 |
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09185202 |
Nov 3, 1998 |
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6245387 |
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Current U.S.
Class: |
428/447 |
Current CPC
Class: |
C09D 4/00 20130101; Y10T
428/31663 20150401; C03C 17/30 20130101; B82Y 40/00 20130101; B82Y
30/00 20130101; B05D 1/185 20130101; C09D 4/00 20130101; C08G 77/04
20130101 |
Class at
Publication: |
428/447 |
International
Class: |
B32B 009/04 |
Claims
1. A process for treating a surface of a substrate G containing OH
or nitrogen hydrogen bonds and surrounded by air, the process
including the steps of: a) moistening the surface with water; b)
contacting the surface with silane groups having the formula
19wherein R represents polar or nonpolar groups including
hydrocarbons or halogenated hydrocarbons, and X is selected from
the group consisting of esters, ethers, and halogens; c) allowing
the silane groups to react with the OH or nitrogen hydrogen bonds
and water at the surface to create a film formed of chains having
the formula 20wherein n is around 100 or more; d) allowing the X
atom at the end of the chain to react with water to produce a
molecule having the structure 21at the end of the chain; and e)
contacting the surface with a capping agent having the formula
22wherein R.sup.1 may include any combination of inert and reactive
groups; and f) allowing the capping agent to react with the
molecule to result in a chain having the formula 23
2. The process according to claim 1, wherein the substrate G
includes silica molecules.
3. The process according to claim 2, wherein the substrate G is
formed from a material selected from the group consisting of glass,
ceramics and silica-containing minerals.
4. The process according to claim 1, wherein the substrate G
includes organic molecules.
5. The process according to claim 1, wherein R is methyl.
6. The process according to claim 1, wherein R is selected from the
group consisting of phenyl, ethyl, methyl, butyl, amyl, and larger
alkyl groups.
7. The process according to claim 1, wherein R consists of 50%
methyl groups and 50% phenyl groups, resulting in improved abrasion
resistance of the film.
8. The process according to claim 1, wherein R consists of polar
groups.
9. The process according to claim 1, wherein R consists of nonpolar
groups.
10. The process according to claim 1, wherein R.sup.1 consists of
chemically inert groups.
11. The process according to claim 1, wherein R.sup.1 consists of
chemically reactive groups.
12. The process according to claim 1, wherein the step of
contacting the surface with silane groups comprises chemically
depositing the siloxane groups on the surface using a vapor
machine.
13. The process according to claim 1, wherein the step of
contacting the surface with silane groups comprises a wipe-on
method.
14. The process according to claim 1, wherein the step of
contacting the surface with silane groups comprises a dipping, or
spraying procedure.
15. The process according to claim 1, wherein the step of
moistening the surface comprises a step of priming the surface with
cyclohexylamine.
16. A process for manufacturing water-resistant glass G in an
environment including air, comprising the steps of: a) coating the
glass with a somewhat water-resistant film formed of chains having
the formula 24wherein R consists of nonpolar groups, X is selected
from the groups consisting of esters, ethers and halogens, and n is
around 100 or more, the film being chemically bonded with the
glass; b) allowing the X atom at the end of the chain to react with
water to produce a molecule having the structure 25at the end of
the chain; and c) contacting the surface with a capping agent
having the formula 26wherein R.sup.1 consists of inert groups; and
d) allowing the capping agent to react with the molecule to result
in a greatly water-resistant film formed from chains having the
formula 27
17. The process according to claim 16, wherein the somewhat
water-resistant film comprises chains of dimethylsiloxane.
18. The process according to claim 16, wherein the capping agent is
trimethylchlorosilane.
19. The process according to claim 16, wherein R is selected from
the group consisting of phenyl, ethyl, methyl, butyl, amyl and
larger alkyl groups.
20. The method according to claim 16, wherein R comprises
approximately 50% methyl groups and 50% phenyl groups, resulting in
improved abrasion-resistance of the highly water-resistant
film.
21. A process for treating a surface of a substrate G containing OH
or nitrogen hydrogen bonds and surrounded by air, the process
including the steps of: a) moistening the surface with water; b)
contacting the surface with silane groups having the formula
28wherein R consists of polar or nonpolar groups, and X is selected
from the group consisting of esters, ethers and halogens; c)
allowing the silane groups to react with the OH or nitrogen
hydrogen bonds and water at the surface to create a film formed of
chains having the formula 29wherein n is around 100 or more, and
the film is chemically bonded to the surface; d) allowing the X
atom at the end of the chain to react with water to produce a
molecule having the structure 30at the end of the chain; and e)
contacting the surface with a capping agent having the formula
31wherein R.sup.1 consists of chemically active groups, and f)
allowing the capping agent to react with the molecule to result in
a new end molecule having the formula 32wherein the new end
molecule serves as a solid state ion exchanger or attachment point
for chemically bound enzymes, chelating agents, dyes, chemical
indicators, or the like.
22. The process according to claim 21, wherein the substrate G
includes silica molecules.
23. The process according to claim 22, wherein the substrate G is
formed from a material selected from the group consisting of glass,
ceramics, and silica-containing minerals.
24. The process according to claim 21, wherein the substrate G
includes organic molecules.
25. The process according to claim 21, wherein R is methyl.
26. The process according to claim 21, wherein the film consists of
chains of dimethylsiloxane.
27. A film for altering the properties of a surface G containing OH
or nitrogen hydrogen bonds and surrounded by air, the film
consisting of a polymer including: a) an anchor group having the
formula 33wherein R represents polar or nonpolar groups including
hydrocarbons or halogenated hydrocarbons; b) a chain of siloxane
groups having a first end and a second end, the first end of the
chain being chemically bound to the silicon molecule of the anchor
group, the chain having the formula 34where n is around 100 or
more; and c) a terminal group of molecules chemically bound to the
second end of the chain, the terminal group having the structure
35where R.sup.1 may include any combination of inert and reactive
groups.
28. The film according to claim 27, wherein R.sup.1 is the same as
R.
29. The film according to claim 27, wherein R is methyl.
30. The film according to claim 27, wherein R is selected from the
group consisting of phenyl, ethyl, methyl, butyl, amyl, and larger
alkyl groups.
31. The film according to claim 27, wherein R consists of polar
groups.
32. The film according to claim 27, wherein R consists of nonpolar
groups.
33. The film according to claim 27, wherein R.sup.1 consists of
chemically inert groups.
34. The film according to claim 27, wherein R.sup.1 consists of
chemically reactive groups.
35. In a process of manufacturing a water-resistant film for
protecting a surface G containing OH or nitrogen hydrogen bonds
wherein the process comprises the step of coating the glass with a
polymer having i) an anchor group having the formula 36wherein R
consists of nonpolar groups, and ii) a chain of siloxane groups,
the chain having a first end and a second end, the first end of the
chain being chemically bound to the silicon molecule of the anchor
group, the chain having the formula 37where n is around 100 or
more, and iii) a terminal group of molecules chemically bound to
the second end of the chain, the terminal group having the formula
38wherein R.sup.1 consists of inert groups, and X is selected from
the group consisting of esters, ethers and halogens, the
improvement comprising the steps of a) allowing the X atom of the
terminal group to react with water to produce a new terminal group
having the formula 39b) replacing the new terminal group with a
final terminal group having the structure 40wherein R.sup.1
consists of inert groups.
36. The improvement according to claim 35, wherein the siloxane
groups consist of dimethylsiloxane groups.
37. The improvement according to claim 36, wherein the final
terminal group consists of a trimethylsiloxane group.
38. The improvement according to claim 35, wherein R.sup.1 is the
same as R.
39. The improvement according to claim 35, wherein R is selected
from the group consisting of phenyl, ethyl, methyl, butyl, amyl,
and larger alkyl groups.
40. The improvement according to claim 35, wherein the step of
replacing the new terminal group comprises the substeps of: a)
contacting the surface with a capping agent having the formula 41b)
allowing the capping agent to react with the new terminal group to
result in an inert final terminal group.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to silicone films, and more
specifically to application of such films to glass and other
surfaces.
[0003] 2. Description of the Prior Art
[0004] Various methods exist for manufacturing easily cleanable,
water repellent glass products, including shower doors,
windshields, glass entry doors and glass partitions in restaurants.
Two such methods are disclosed in U.S. Pat. Nos. 5,415,927 to
Hirayama et el. and 4,263,350 to Valimont.
[0005] In another method currently in use, the glass is coated with
a film consisting of chains of silicone molecules, with each chain
chemically bound at one end to the surface of the glass. Each chain
contains from dozens to hundreds of dimethylsiloxane (DMS) units
and is terminated at its free end by either a hydroxyl (OH) group
or a chlorine attached to a silicon, which soon reacts with water
vapor in the air to produce OH groups. This existing film is in use
on a number of glass products as well as other silica-containing
products such as granite, porcelain, earthenware and stoneware, and
for the most part, has performed satisfactorily. However, the
water-repellence of the film is limited to some extent by the
presence of the terminal OH groups, which are highly
water-attracting.
[0006] Accordingly, it is an object of the present invention to
improve the water-resistance of silicone films on glass, and to
provide a support film for chemically active substances.
[0007] Another object of the invention is to produce a family of
silicone films for treating a variety of products such as the
silica-containing products previously mentioned as well as organic
substances including paper, cotton, nylon, leather, and wood, in
order to improve the surface properties of those products.
SUMMARY OF THE INVENTION
[0008] Briefly, to achieve the desired objects of the instant
invention in accordance with the preferred embodiments thereof, a
silicone film is attached to a surface by chemical bonding. The
silicone film consists of chains of siloxane groups, each chain
terminating in an end molecule which is either an ester, an ether,
or a halogen. The end molecule is allowed to react with water,
either water vapor in the surrounding air or by covering the
surface with liquid water, to produce an end OH group. The surface
is then contacted with a capping agent which reacts with the OH
group to produce a new end group which improves the properties of
the film.
[0009] The specific improvement in properties will depend on the
siloxane groups used, as well as the composition of the capping
agent. In general, the siloxane groups have the formula 1
[0010] and the capping agent has the formula 2
[0011] For water-repellent applications, R consists of nonpolar
groups, and R.sup.1 consists of inert groups. For
non-water-repellent applications, R consists of polar or nonpolar
groups. In other applications, R.sup.1 could consist of chemically
active groups, enabling the surface to be used as a solid state ion
exchanger or an attachment point for chemically bound enzymes,
chelating agents, dyes, chemical indicators or other
substances.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing and further and more specific objects and
advantages of the instant invention will become readily apparent to
those skilled in the art from the following detailed description of
the preferred embodiments thereof taken in conjunction with the
drawings in which:
[0013] FIG. 1 is a diagrammatic representation of a surface coated
with a prior art water-repellent film; and
[0014] FIG. 2 is a diagrammatic representation of a surface coated
with a water-repellent film manufactured using the process of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Turning now to the drawings, attention is first directed to
FIG. 1, which shows a surface G which has been treated with a
water-repellent film using a prior art process. In the most
widely-used application of the process, the surface G is glass, but
the process may actually be used to treat any surface containing OH
or nitrogen hydrogen bonds, such as silica-containing surfaces
including granite, porcelain, earthenware and stoneware, as well as
organic substances including cotton, paper, nylon, leather and
others. The film comprises chains of dimethylsiloxane (DMS) groups.
Each chain is chemically bonded at one end to an oxygen (O)
molecule, which in turn is chemically bonded to the surface G. The
opposite end of each chain includes either a hydroxyl (OH) group or
a chlorine attached to silicone, which will soon react with water
vapor in the surrounding air to produce an OH group.
[0016] The process by which the film of FIG. 1 is created is as
follows. Initially, the surface G is moistened. The moistened
surface can be represented as shown in simplified form below: 3
[0017] In reality, however, the number of 4
[0018] molecules at the surface would be much greater than the
number of O--H groups on the surface (a ratio of about 100:1).
[0019] Next, the surface is treated with dimethyldichlorosilane
using Portable Vapor machines which may be adapted to fixed site
chambers for large volume operations, or by using a wipe-on method
or a dipping or spraying procedure. Where necessary,
cyclohexylamine is used as a primer to ensure sufficient moisture
for the chemical reaction to take place. After the
dimethyldichlorosilane has been applied, a dimethyldichlorosilane
molecule approaches an O--H group at the surface, as shown below:
5
[0020] The ensuing reaction results in an anchor molecule which
will chemically bond the film to the surface G, as shown below:
6
[0021] The Si--Cl bond then reacts with water absorbed on the
surface G as follows: 7
[0022] resulting in the following structure: 8
[0023] This structure then reacts with a DMS molecule as follows:
9
[0024] resulting in the molecule shown below: 10
[0025] The process of steps (c)-(f) above is repeated about 100
times until no more water remains for steps (c) and (d). The
product has the formula: 11
[0026] where n is around 100 or more. The groups in the brackets
are highly water repellent. However, the chlorine atom at the end
of the chain slowly reacts over several hours with water vapor in
the air to result in a product having the formula: 12
[0027] which is equivalent to the structure shown in FIG. 1. The
Si--O--H group at the end of this final product is
water-attracting, thus reducing the overall water repellence of the
entire film, and creating a site for undesirable chemical
reactions.
[0028] In the improved process of the instant invention, a surface
coated with the above film is then treated with
trimethylchlorosilane, which reacts with the OH group at the end of
the DMS chain to produce trimethylchlorosiloxane (TMS). The final
product is a film having the formula: 13
[0029] which is equivalent to the structure shown in FIG. 2.
Because the TMS group at the end of the chain is chemically inert,
the water-resistance of the film is much greater than that of the
prior art film.
[0030] The silicone film produced by the process of steps (a)-(i)
above is one specific example of the invention, intended for
water-repellent applications. In a more general case, the moistened
surface G is first contacted with silane groups having the formula
14
[0031] wherein R represents polar or nonpolar groups including
hydrocarbons or halogenated hydrocarbons, and X is selected from
the group consisting of esters, ethers, and halogens. The silane
groups then react with the OH or nitrogen hydrogen bonds and water
at the surface G to chemically bond the film to the surface G, in a
process analogous to step (b) above. A series of reactions
analogous to those shown in steps (b)-(f) above results in a
polymer having the formula: 15
[0032] where n is around 100 or more. The X atom at the end of the
chain then reacts with water vapor in the surrounding air resulting
in a molecule having the formula: 16
[0033] The surface is then contacted with a capping agent having
the formula: 17
[0034] where R.sup.1 may include any combination of inert and
reactive groups. The capping agent reacts with the OH group at the
end of the chain, resulting finally in a chain having the formula:
18
[0035] The properties of the film manufactured using this process
will depend on the choice of R and R.sup.1, and to a lesser extent,
X. Choosing X from the chloro group gives the lowest material cost
and gives a faster reaction time, while esters and ethers are less
reactive but produce less troublesome coproducts and require
different processing conditions.
[0036] In general, for water repellent applications, R consists of
nonpolar groups and R.sup.1 consists of chemically inert groups. If
R consists of approximately 50% methyl groups and 50% phenyl
groups, the abrasion-resistance of the film is improved. The
abrasion-resistance of the film can also be improved by connecting
the DMS chains with methyltrichlorosilane (which causes branched
chains and additional ends). The methyltrichlorosilane would cause
the chains to be tied together in a three-dimensional structure,
which would resist abrasion better than a two-dimensional
structure.
[0037] For non-water repellent applications, R consists of polar or
nonpolar groups. If R.sup.1 is selected from chemically reactive
groups, the end molecule can provide an attachment point for
enzymes, chelating agents, ion exchange elements, chemical
indicators and other substances.
[0038] Various other modifications and variations to the
embodiments herein chosen for purposes of illustration will readily
occur to those skilled in the art. To the extent that such
variations and modifications do not depart from the spirit of the
invention, they are intended to be included within the scope
thereof which is assessed only be a fair interpretation of the
following claims.
* * * * *