U.S. patent application number 09/887844 was filed with the patent office on 2001-11-22 for polymer surface coating made by coalescing a polymer particulate with a coalescing agent.
This patent application is currently assigned to Ecolab Inc.. Invention is credited to Anderson, Bryan M., Hei, Robert D.P., Olson, Keith E..
Application Number | 20010043987 09/887844 |
Document ID | / |
Family ID | 23162221 |
Filed Date | 2001-11-22 |
United States Patent
Application |
20010043987 |
Kind Code |
A1 |
Olson, Keith E. ; et
al. |
November 22, 2001 |
Polymer surface coating made by coalescing a polymer particulate
with a coalescing agent
Abstract
Continuous coatings can be prepared using novel two part
compositions and methods. The two part compositions of the
invention comprise, in separate containers, a powder polymer
composition and a coalescing agent. The powder composition has
preferred particle size distribution and composition for use in the
compositions or methods of the invention. The coalescing agents of
the invention cooperate with the powder part to result in a
excellent finish having the appropriate drying hardness,
durability, etc. The novel method of the invention involves
contacting a coalescing agent with polymer particles in a variety
of coating methods. The particles and the coalescing agent interact
to form a continuous coating layer or finish layer. The basic
coating formation methods of the invention can be embodied in a
number of methods or protocols including applying a sold polymer to
the liquid coalescing agent, applying the agent to the polymer
particulate or applying the liquid and polymer simultaneously. In
any protocol, a desirable floor finish can be easily formed. This
invention is particularly suitable for a floor finish
composition.
Inventors: |
Olson, Keith E.; (Apple
Valley, MN) ; Anderson, Bryan M.; (St. Paul, MN)
; Hei, Robert D.P.; (Baldwin, WI) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
Ecolab Inc.
St. Paul
MN
|
Family ID: |
23162221 |
Appl. No.: |
09/887844 |
Filed: |
June 22, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09887844 |
Jun 22, 2001 |
|
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09301164 |
Apr 28, 1999 |
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Current U.S.
Class: |
427/189 ;
427/195; 427/201 |
Current CPC
Class: |
B05D 3/10 20130101; C09D
7/00 20130101 |
Class at
Publication: |
427/189 ;
427/195; 427/201 |
International
Class: |
B05D 001/12 |
Claims
We claim:
1. A method of forming a coating layer on a substrate, the coating
layer comprising a unitary layer having a thickness of about 1 to
about 20 microns, the method comprising: (a) combining at a
treatment locus on the substrate; (i) a liquid coalescing agent;
and (ii) a polymer composition having a particle size useful in
film formation, the polymer substantially free of an aqueous or
solvent medium; and (b) permitting the coalescing agent to convert
the polymer particles composition into a substantially continuous
coating.
2. The method of claim 1 wherein the coalescing agent comprises a
non-organic silicone.
3. The method of claim 1 wherein the coalescing agent comprises a
liquid with a VOC less than 5 mm-Hg and the coalescing agent
substantially evaporates during coating formation.
4. The method of claim 1 wherein the coalescing agent comprises a
liquid terpene comprising a diterpene, a triterpene or higher
terpene or mixtures thereof.
5. The method of claim 1 wherein the coalescing agent comprises an
ether alcohol having a VOC of less than 5 mm-Hg.
6. The method of claim 5 wherein the coalescing agent comprises a
mixture of a lower alcohol and the ether alcohol.
7. The method of claim 5 wherein the coalescing agent comprises a
C.sub.1-6 monoalkyl or dialkyl ether of a polyalkylene glycol
8. The method of claim 1 wherein the polymer has a particle size
less than 50 .mu.m.
9. The method of claim 1 wherein the polymer has a particle size
less than 40 .mu.m.
10. The method of claim 1 wherein the polymer has a particle size
of about less than 15 .mu.m.
11. The method of claim 5 wherein the coalescing agent comprises
diethylene glycol mono C.sub.1-6 alkyl ether.
12. The method of claim 5 wherein the coalescing agent comprises an
C.sub.1-6 alkyl ether of an alkylene glycol
13. The method of claim 5 wherein the coalescing agent comprises
diethylene glycol ethyl ether
14. The method of claim 5 wherein the coalescing agent comprises
ethylene glycol mono alkyl ether.
15. The method of claim 5 wherein the coalescing agent comprises
ethylene glycol mono ethyl ether
16. The method of claim 1 wherein there are about 0.2 to about 2
part of the coalescing agent per each part by weight of the polymer
and the resulting coating has a thickness greater than 3
microns.
17. The method of claim 1 wherein there are about 0.5 to about 1
part of the coalescing agent per each part by weight of the polymer
and the resulting coating has a thickness greater than 3
microns.
18. The method of claim 1 wherein the polymer composition comprises
a polymer and plasticizer.
19. The method of claim 18 wherein the polymer composition also
comprises a wax and the substrate comprises a floor surface.
20. The method of claim 1 wherein the polymer composition comprises
a vinyl polymer.
21. The method of claim 20 wherein the vinyl polymer composition
comprises a styrene polymer.
22. The method of claim 20 wherein the vinyl polymer composition
comprises an acrylic comprising methyl methacrylate, n-butyl
acrylate or mixtures thereof.
23. The method of claim 1 wherein the polymer composition comprises
an urethane polymer.
24. The method of claim 1 wherein the finish has a thickness of
about 3 to about 10 microns.
25. The method of claim 1 wherein the finish polymer composition is
placed on the substrate prior to the coalescing agent.
26. The method of claim 1 wherein the coalescing agent is placed on
the substrate prior to the polymer composition.
27. The method of claim 1 wherein the coalescing agent and the
polymer composition are separately atomized to form an atomized
coalescent and an atomized polymer composition and the atomized
coalescing agent and the atomized polymer composition are combined
to form a spray treatment composition directed to the treatment
locus.
28. The method of claim 1 wherein the coating is formed in less
than 60 minutes.
29. The method of claim 1 wherein the coating is formed in less
than 10 minutes.
30. The method of claim 1 wherein the coalescent layer evaporates
with no energy input to cure the layer other than ambient
energy.
31. The method of claim 1 wherein the substrate comprises a planar
substrate.
32. The method of claim 1 wherein the substrate comprises a curved
substrate
33. The method of claim 1 wherein the substrate comprises a
substrate with complex surface.
34. The method of claim 1 wherein the polymer is a cellulosic
composition and the coalescing agent is an aqueous solution of a
lower alcohol.
35. The method of claim 1 wherein the polymer comprises a vinyl
polymer comprising styrene and an acrylic monomer.
36. The method of claim 35 wherein the acrylic monomer comprises
methyl methacrylate, butyl acrylate or mixtures thereof and the
coalescing agent comprises an ether alcohol.
37. The method of claim 35 wherein the coalescing agent comprises
an ether alcohol and a lower alcohol.
38. The method of claim 35 wherein the coalescing agent comprises a
polyalkylene glycol C.sub.1-6 alkyl ether.
39. The method of claim 35 wherein the coalescing agent comprises a
dialkylene glycol C.sub.1-6 alkyl ether.
40. The method of claim 35 wherein the coalescing agent comprises a
monoalkylene glycol monoalkyl ether.
41. The method of claim 35 wherein the coalescing agent comprises a
diethylene glycol C.sub.1-6 alkyl ether.
42. The method of claim 35 wherein the coalescing agent comprises a
monoethylene glycol C.sub.1-6 alkyl ether.
43. The method of claim 35 wherein the coalescing agent comprises a
diethylene glycol monoethyl ether.
44. The method of claim 35 wherein the coalescing agent comprises
an ethylene glycol monoethyl ether.
45. A two part coating composition, resulting in a unitary coating
layer having a thickness of about 1 to about 20 microns, the
composition comprising, in separate containers: (a) a particulate
first part comprising a floor finish polymer composition
substantially free of a liquid aqueous or organic medium; and (b) a
liquid second part comprising a coalescing agent, said agent with
the capacity to convert the polymer particle composition into a
continuous floor finish.
46. The composition of claim 45 wherein the liquid coalescing agent
has a VOC less than 5 mm-Hg.
47. The composition of claim 45 wherein the coalescing agent
comprises a nonorganic silicone.
48. The composition of claim 45 wherein the coalescing agent
comprises a liquid terpene comprising a diterpene, a triterpene or
higher terpene or mixtures thereof.
49. The composition of claim 45 wherein the particle has a size
less than 40 .mu.m.
50. The composition of claim 45 wherein the particle has a size
less than 35 .mu.m.
51. The composition of claim 45 wherein the particle has a size
about 10 .mu.m to 25 .mu.m.
52. The composition of claim 45 wherein the coalescing agent
comprises an ether alcohol.
53. The composition of claim 52 wherein the coalescing agent
comprises a mixed lower alcohol and ether alcohol.
54. The composition of claim 52 wherein the coalescing agent
comprises monoalkyl or dialkyl ether of an polyalkylene glycol.
55. The composition of claim 52 wherein the coalescing agent
comprises diethylene glycol mono alkyl ether.
56. The composition of claim 52 wherein the coalescing agent
comprises an alkyl ether of an alkylene glycol
57. The composition of claim 52 wherein the coalescing agent
comprises diethylene glycol ethyl ether
58. The composition of claim 52 wherein the coalescing agent
comprises ethylene glycol mono alkyl ether.
59. The composition of claim 52 wherein the coalescing agent
comprises ethylene glycol ethyl ether
60. The composition of claim 45 wherein there are about 0.2 to
about 2 part of the coalescing agent per each part by weight of the
polymer.
61. The composition of claim 45 wherein there are about 0.5 to
about 1 part of the coalescing agent per each part by weight of the
polymer.
62. The composition of claim 45 wherein the polymer composition
comprises a polymer and plasticizer.
63. The composition of claim 62 wherein the polymer composition
also comprises a wax.
64. The composition of claim 63 wherein the polymer composition
comprises a vinyl polymer.
65. The composition of claim 64 wherein the vinyl polymer
composition comprises a styrene polymer.
66. The composition of claim 64 wherein the vinyl polymer comprises
and acrylic comprising methyl methacrylate, n-butyl acrylate or
mixtures thereof.
67. The composition of claim 45 wherein the polymer composition
comprises an urethane polymer.
68. The composition of claim 45 wherein the polymer is a cellulosic
composition and the coalescing agent is an aqueous solution of a
lower alcohol.
69. A method of forming a coating layer on a floor surface, the
finish layer comprising a unitary layer having a thickness of about
1 to about 20 microns, the method comprising: (i) combining on a
floor treatment locus, the locus having an area of greater than
about 0.09 meter.sup.2; (a) a liquid coalescing agent having a VOC
less than 10 mm-Hg; and (b) a particulate floor finish polymer
composition comprising an acrylic polymer, a urethane polymer or
mixtures thereof, the particulate having a particle size of about 3
to about 50 microns; and (ii) permitting the coalescing agent to
convert the polymer composition into a continuous floor finish in a
time period of less than about 60 minutes.
70. The method of claim 69 wherein the coalescing agent has a VOC
of less than 5 mm-Hg and substantially evaporates before the finish
is formed.
71. The method of claim 69 wherein the polymer has a particle size
of 10 to 35 .mu.m.
72. The method of claim 69 wherein the polymer is free of a liquid
aqueous or solvent medium.
73. The method of claim 69 wherein the coalescing agent comprises
an ether alcohol with a VOC less than 1 mm-Hg.
74. The method of claim 73 wherein the coalescing agent comprises a
mixed lower alcohol and ether alcohol.
75. The method of claim 73 wherein the coalescing agent comprises
an alkyl ether of an polyalkylene glycol.
76. The method of claim 73 wherein the coalescing agent comprises
diethylene glycol mono alkyl ether.
77. The method of claim 73 wherein the coalescing agent comprises
diethylene glycol ethyl ether.
78. The method of claim 73 wherein the coalescing agent comprises a
monoalkyl or dialkyl ether of an alkylene glycol.
79. The method of claim 73 wherein the coalescing agent comprises
ethylene glycol mono alkyl ether.
80. The method of claim 73 wherein the coalescing agent comprises
ethylene glycol ethyl ether
81. The method of claim 69 wherein the coalescing agent comprises a
liquid terpene comprising a diterpene, a triterpene or higher
terpene or mixtures thereof.
82. The method of claim 69 wherein the coalescing agent comprises a
cyclic silicone.
83. The method of claim 69 wherein there are about 0.2 to about 2
part of the coalescing agent per each part by weight of the
polymer.
84. The method of claim 69 wherein there are about 0.5 to about 1
part of the coalescing agent per each part by weight of the
polymer.
85. The method of claim 84 wherein the polymer composition
comprises a polymer and plasticizer.
86. The method of claim 85 wherein the polymer composition also
comprises a wax.
87. The method of claim 69 wherein the polymer composition
comprises a vinyl polymer.
88. The method of claim 87 wherein the polymer composition
comprises a styrene polymer.
89. The method of claim 87 wherein the polymer composition
comprises an acrylic comprising methyl methacrylate, n-butyl
acrylate or mixtures thereof.
90. The method of claim 69 wherein the polymer composition
comprises an urethane polymer.
91. The method of claim 69 wherein the finish has a thickness of
about 3 to about 10 microns.
92. The method of claim 69 wherein the finish polymer composition
is placed on the substrate prior to the coalescing agent.
93. The method of claim 69 wherein the coalescing agent is placed
on the substrate prior to the polymer composition.
94. The method of claim 69 wherein the coalescing agent and the
polymer composition are separately atomized to form an atomized
coalescent and an atomized polymer composition and the atomized
coalescing agent and the atomized polymer composition are combined
to form a spray treatment composition directed to the treatment
locus.
95. The method of claim 69 wherein the coating covers the entire
available surface.
96. The method of claim 69 wherein the coating covers at least 5%
of the available surface.
97. The method of claim 69 wherein the coalescent layer evaporates
with no energy input to cure layer other than ambient energy.
98. The method of claim 69 wherein the substrate comprises a planar
substrate.
99. The method of claim 69 wherein the substrate comprises a curved
substrate.
100. The method of claim 69 wherein the substrate comprises a
substrate with complex surface.
101. The method of claim 69 wherein the locus has an area of
greater than 10 m.sup.2.
102. The method of claim 69 wherein the polymer comprises a vinyl
polymer comprising styrene and an acrylic monomer.
103. The method of claim 102 wherein the acrylic monomer is methyl
methacrylate, butyl acrylate or mixtures thereof and the coalescing
agent comprises an ether alcohol.
104. The method of claim 102 wherein the coalescing agent comprises
an ether alcohol and a lower alcohol.
105. The method of claim 102 wherein the coalescing agent comprises
a polyalkylene glycol C.sub.1-6 alkyl ether.
106. The method of claim 102 wherein the coalescing agent comprises
a dialkylene glycol C.sub.1-6 alkyl ether.
107. The method of claim 102 wherein the coalescing agent comprises
a monoalkylene glycol monoalkyl ether.
108. The method of claim 102 wherein the coalescing agent comprises
a diethylene glycol C.sub.1-6 alkyl ether.
109. The method of claim 102 wherein the coalescing agent comprises
a monoethylene glycol C.sub.1-6 alkyl ether.
110. The method of claim 102 wherein the coalescing agent comprises
a diethylene glycol monoethyl ether.
111. The method of claim 102 wherein the coalescing agent comprises
an ethylene glycol monoethyl ether.
112. A floor coating comprising a single layer having a thickness
of about 2 to 12 microns, the coating comprising a continuous
polymer layer having an entrapped residue in the coating the
residue comprising a coalescing agent with a VOC of less than 10
mm-Hg, the residue substantially free of an aqueous or solvent
medium.
113. The coating of claim 112 wherein the coalescing agent
comprises a nonorganic silicone.
114. The coating of claim 112 wherein the coalescing agent has a
VOC less than 5 mm-Hg.
115. The coating of claim 112 wherein the coalescing agent
comprises a liquid terpene comprising a diterpene, a triterpene or
higher terpene or mixtures thereof.
116. The coating of claim 112 wherein the coalescing agent
comprises an ether alcohol.
117. The coating of claim 112 wherein the coalescing agent
comprises a mixture of a lower alcohol and the ether alcohol.
118. The coating of claim 112 wherein the coalescing agent
comprises an alkyl ether of an alkylene glycol
119. The coating of claim 112 wherein the coalescing agent
comprises a C.sub.1-6 alkyl ether of an polyalkylene glycol
120. The coating of claim 112 wherein the coalescing agent
comprises diethylene glycol mono C.sub.1-6 alkyl ether.
121. The coating of claim 112 wherein the coalescing agent
comprises diethylene glycol ethyl ether
122. The coating of claim 112 wherein the coalescing agent
comprises ethylene glycol mono alkyl ether.
123. The coating of claim 112 wherein the coalescing agent
comprises ethylene glycol ethyl ether
124. The coating of claim 112 wherein the coating thickness is
greater than 4 microns.
125. The coating of claim 112 wherein the coating thickness is
greater than 5 microns.
126. The coating of claim 112 wherein the polymer composition
comprises a polymer and plasticizer.
127. The coating of claim 126 wherein the polymer composition also
comprises a wax.
128. The coating of claim 127 wherein the polymer composition
comprises a vinyl polymer.
129. The coating of claim 128 wherein the polymer composition
comprises a styrene polymer.
130. The coating of claim 129 wherein the polymer composition
comprises a styrene and acrylic copolymer.
131. The coating of claim 128 wherein the polymer composition
comprises methyl methacrylate, n-butyl acrylate or mixtures
thereof.
132. The coating of claim 112 wherein the polymer composition
comprises an urethane polymer.
133. The coating of claim 112 wherein the coating has a thickness
of about 3 to about 6 microns.
134. The coating of claim 112 wherein the finish polymer
composition is placed on the substrate prior to the coalescing
agent.
135. The coating of claim 112 wherein the coalescing agent is
placed on the substrate prior to the polymer composition.
136. The coating of claim 112 wherein the coalescing agent and the
polymer composition are separately atomized to form an atomized
coalescent and an atomized polymer composition and the atomized
coalescing agent and the atomized polymer composition are combined
to form a spray treatment composition directed to the treatment
locus.
137. The coating of claim 112 wherein the coating covers the entire
available surface.
138. The coating of claim 112 wherein the coating covers at least
5% of the available surface.
139. The coating of claim 112 wherein the coalescent layer
evaporates with no energy input to cure layer other than ambient
energy.
140. The coating of claim 112 wherein the substrate comprises a
planar substrate.
141. The coating of claim 112 wherein the substrate comprises a
curved substrate.
142. The method of claim 1 wherein the coating comprises a
biocide.
143. The coating of claim 60 wherein the coating is formed on a
flooring unit during factory finishing.
144. The coating of claim 112 wherein the coating is formed on a
flooring unit during factory finishing.
145. The coating of claim 60 wherein the coating comprises a
biocide.
146. The method of claim 112 wherein the coating comprises a
biocide.
147. A method of forming a coating layer on a flooring unit used in
forming a floor surface, the coating layer comprising a unitary
layer having a thickness of about 3 to about 12 microns, the method
comprising: (i) combining on a flooring unit, the unit comprising
sheet flooring or an individual floor component having an area of
about 5 to 5000 centimeter.sup.2; (a) a liquid coalescing agent;
and (b) a particulate floor finish vinyl polymer composition, the
particulate having a particle size of about 5 to about 50 microns;
and (ii) permitting the coalescing agent to convert the polymer
composition into a continuous floor finish in a time period of less
than about 10 minutes.
148. The method of claim 147 wherein the coalescing agent has a VOC
of less than 20 mm-Hg and substantially evaporates before the
finish is formed.
149. The method of claim 147 wherein the polymer has a particle
size of 10 to 35 .mu.m.
150. The method of claim 147 wherein the polymer is free of a
liquid aqueous or solvent medium.
151. The method of claim 147 wherein the coalescing agent comprises
an ether alcohol with a VOC less than 10 mm-Hg.
152. The method of claim 147 wherein the coalescing agent comprises
a mixed lower alcohol and ether alcohol.
153. The method of claim 147 wherein there are about 0.2 to about 2
part of the coalescing agent per each part by weight of the
polymer.
154. The method of claim 147 wherein there are about 0.5 to about 1
part of the coalescing agent per each part by weight of the
polymer.
155. The method of claim 153 wherein the polymer composition
comprises a polymer and plasticizer.
156. The method of claim 153 wherein the polymer composition
comprises a styrene polymer and the coalescing agent has a VOC less
than 5 mm-Hg.
157. The method of claim 147 wherein the finish has a thickness of
about 3 to about 10 microns.
158. The method of claim 147 wherein the coating covers the entire
available surface.
159. The method of claim 147 wherein the substrate comprises a
planar substrate.
160. The method of claim 147 wherein the locus has an area of
greater than 10 to 4000 cm .sup.2.
161. The method of claim 147 wherein the locus has an area of
greater than 20 to 2000 cm.sup.2.
162. The method of claim 147 wherein the coating is formed with
energy input that promotes coating formation and coalescent
evaporation in less than 5 minutes.
163. The method of claim 147 wherein the sheet flooring comprises a
vinyl sheet.
164. The method of claim 147 wherein the individual floor component
comprises a quarry tile.
165. The method of claim 45 wherein the coating is formed in less
than 60 minutes.
166. The method of claim 45 wherein the coating is formed in less
than 10 minutes.
Description
FIELD OF THE INVENTION
[0001] The invention relates to compositions and methods used in
the formation of a polymer coating from a polymer particulate. The
coatings of the invention can be made in a uniform continuous
structure. Further, floor finishes having appropriate predetermined
properties such as hardness, thickness, resiliency, and integrity
can be made. One aspect of the invention is a two part coating
system. A second aspect of the invention is a method for forming
the polymer coating of the invention using the two part system and
a number of distinct coating forming protocols. Another aspect of
the invention is a floor finish system that results in substantial
labor savings.
BACKGROUND OF THE INVENTION
[0002] Coating compositions are generally well known and have been
formulated using a variety of technologies such as solvent based,
aqueous liquid and powder systems. Powder coatings have been
electrostatically applied to hard surfaces such as metals and then
baked into a hard resistant finish. Reactive liquid coatings have
been made by combining reactive materials (such as reactive
isocyanates, ethylenically unsaturated reactive systems, reactive
epoxy systems, etc.). Such systems have been applied to surfaces
and then reacted to form a crosslinked hard surface. Further,
coatings have been formed by dissolving typically polymeric
materials in organic solvents at a solids concentration of about 10
to 50 wt.-%. Such solutions are applied and the solvent borne
materials dry to a hard surface by the evaporation the solvent
leaving a polymer coating. In order to increase the add-on of
polymeric solids, polymer materials have been dispersed in aqueous
media to form finish compositions. Lastly, aqueous technologies are
used with active materials at concentrations typically higher than
solvent systems. Such aqueous dispersions have been applied to
surfaces for the purposes of forming a finish layer by serial
application and evaporation of the water. Once the water is
removed, the polymer materials form a useful film typically in a
multi-coating layer. Solvent or aqueous based systems typically
leave a residue of the medium in the coating.
[0003] Typical compositions and methods include those in Michio et
al., Japanese Patent No. 92243309A. Michio et al. teach a
aqueous/solvent coating composition for floors comprising a
polymeric material combined with an ether solvent material adapted
for reduced odor. Feigin, U.S. Pat. No. 4,131,585, teaches a
polyether leveling agent adapted for use in aqueous self-polishing,
dry bright coating compositions. Hacket et al., U.S. Pat. Nos.
4,363,835 and 4,704,429 and Zdanowski et al., U.S. Pat. No.
4,517,330, teach a method of forming floor finishes by applying an
aqueous dispersion of polymer and materials and then dry buffing
the resulting coating at high temperature to either fuse or
crosslink the waxy or reactive coating composition. Bolgiano et
al., U.S. Pat. No. 4,421,782, teach the formation of a coating from
an aqueous system which after drying is radiation cured into a hard
tough surface. Craven, U.S. Pat. No. 3,776,752, teaches
compositions and methods for finishing surfaces. The method
comprises applying a solvent dispersion of a polymer coating
material, drying the applied material to form a coating and then
forming the resulting coating with a finishing agent. Such
finishing agents disclosed by Craven include typical plasticizing
compositions. Lovell, Canadian Patent No. 717,495 (U.K. Patent No.
930,919), teaches the application of an organosol polish
composition. Lovell discloses that the organosol material, when
cosprayed with a solvent material, forms a combined coating which
dries to a hard floor surface. Lewis et al., U.S. Pat. No.
4,168,255, and Gehman et al., U.S. Pat. No. 4,017,662, teach a
polishing method involving the application of an aqueous coating
composition containing a polymer material and finish forming
agents. The polymeric materials combine with the agents as the
aqueous material evaporates leaving a hard floor finish. Berrido,
U.S. Pat. No. 4,747,880, teaches a dry granular floor care product.
The dry granular material is formulated such that it can be
combined with water to form an aqueous solution or dispersion which
can be applied to form a clean shiny appearance after drying. The
prior art coating technology involves heat melted or fused
coatings, reactive crosslinking coatings, or coatings that rely on
a carrier liquid, an evaporating liquid aqueous or solvent medium
for film formation. Such media involve solvents which must
evaporate upon application to initiate coalescing the finish layer.
Further the prior art aqueous compositions typically require two or
more applications to form a finished surface having two or more
distinct layers for a complete floor treatment. The typical
applications of coatings to floors, walls, ceilings and other
environmental hard surfaces can involve rolling, mopping, spray
coating and other conventional methods. A combination of a resin,
solvent (aqueous or organic), diluent, additives and pigment can be
used. A survey of conventional coating composition and techniques
is shown in Kirk-Othmer Concise Encyclopedia of Chemical
Technology, Fourth Edition, Wiley Interscience Publications, pp.
469-482 (John Wiley & Sons, Inc. 1999).
[0004] A need exists for floor coating systems that can be used
with minimal labor in forming a reliable coating with as little as
one application of the coating system. The coating systems of the
invention can be used without substantial heat input for curing or
a substantial proportion of an organic carrier solvent or an
aqueous medium.
BRIEF DISCUSSION OF THE INVENTION
[0005] We have found a two-part system that can be used in a method
for forming a continuous hard durable coating on virtually any
surface. The two-part system comprises a polymer first part in the
form of a finely divided flowable powder or particulate that can be
delivered to a surface without an aqueous or organic solvent or
other carrier liquid. The second part is a liquid part comprising a
liquid coalescent or coalescing agent. In use, the parts are
combined on the floor surface or as they are being delivered to the
floor surface. The coalescing agent causes the polymer powder
uniformly distributed in a finely divided state to coalesce and
form a uniform film or coating within a short time after it came in
contact with the coalescent. The materials can be applied in one of
three application regimens we have defined to date, others may be
developed and used. The powder can be uniformly placed on a target
surface first followed by a careful uniform application of the
coalescing agent. Second, the coalescing agent can be placed on the
target surface followed by a careful uniform application of the
powder particle. Lastly, the materials can be formed into a fine
dispersion of the material in air, combined in an application
device and simultaneously delivered to the surface. In such a
process, the powder and coalescing agent can be atomized in
separate atomizers and combined after atomization to form a spray
of the final coating components.
[0006] One important application of the coating technology of this
invention is to form hard, uniform coatings with regular thickness
and integrity on floors. These coatings are typically 1 to 20
microns, preferably 3 to 12 microns, most preferably 4 to 10
microns in thickness. The floor finishes can have properties such
as hardness, thickness, resiliency, integrity and wear resistance
that meet or exceed requirements of current floor finish
technology. Two or more coatings can be made if each coating
provides a unique property. Layers of different hardness can be
used. A first layer can be formed from a colored layer with a
second uncolored clear layer. A first layer can be used with a
second layer having a COF additive or biocide. A first acrylic
layer can be used with a second urethane layer.
[0007] Floor surfaces that can be treated include installed floors,
uninstalled sheet vinyl or uninstalled flooring units. The coatings
can be applied during manufacture of the flooring as one of the
final steps in manufacture, can be applied to the flooring at an
installation site just prior to installation, can be applied to the
floor after installation or during routine maintenance. The primary
substrates or supports for conventional coating systems include
paper and paperboard, polymer films such as polyethylene,
polyethylene terephthalate, metal foils, woven and non-woven
fabrics, fibers, metal coils and a variety of environmental
surfaces including floors, walls, ceilings, hard surfaces, exterior
walls and other rough, curved or flat surfaces. Each of these kinds
of surfaces utilizes coating compositions and methods adapted for
each coating environment. Many coating processes are used in the
industry including methods that create single and multiple layers.
The precision and uniformity of the coating is important for
consistent coverage, uniform appearance and wear properties.
[0008] For the purpose of this patent application, the term
"coating" refers to a single or multiple coating of a polymer
material in a substantially uniform layer. In this application
uniform indicates the thickness does not vary more than about .+-.3
microns, preferably .+-.2 microns, from place to place in the
coating. Such a coating can be applied under factory conditions or
in the field. The term "floor finish" typically connotes a floor
coating having a thickness of greater than 1 micron but typically
less than 12 microns, preferably less than 5, microns having a
single layer formed from the coalesced distribution of the polymer
particles. Such floor finishes can be applied during floor tile
manufacture or at a building location. Traditional floor finish
methods use multiple (typically 4 or 5) applications of the finish
forming liquid to result in a multi-layer or laminate structure.
Each layer typically have a thickness less than 2 microns, often as
little as 1 micron. The technology of the invention, however, can
be used to form multiple layers. The term "polymer particle"
typically connotes a polymer material typically made by
polymerizing ethylenically unsaturated monomers and then
comminuting such a polymeric material into a particle or
particulate collection. The particles in the particulate can have a
major dimension less than about 40 microns, preferably less than
about 25 microns but preferably greater than about 10 microns. The
term "coalescing agent" typically connotes an organic or silicone
liquid material that causes the polymer particle to coalesce into a
single layer floor finish film having a dimension greater than
about 1 micron but less than about 12 microns. Such coalescing
agents are materials that can cause the polymer particles to flow
of fuse into a continuous layer before evaporation and are
typically organic materials with a relatively low VOC (volatile
organic compound content), typically less than about 10 mm-Hg
preferably less than 5 mm-Hg, often less than 1 mm-Hg. More
volatile, higher VOC coalescing agents can be used in a factory
location where dying speed is important. In such locations, higher
VOC coalescing agents can be recovered and recycled during coating
operations. The more volatile solvent coating media carrier
materials typically have a VOC greater than 20 mm-Hg and more 25 to
80 mm-Hg. A coalescing agent can be identified as a coalescing
agent using the following procedure. The polymer floor finish
particulate or powder material can be placed on a surface of a
glass dish or microscope slide. About 0.5 grams, or less,
sufficient to thinly cover the glass surface, of the slide or dish
is used. Onto the particulate or powder is added about an equal
amount by weight of a candidate coalescing agent. The test or
candidate coalescing agent can be lightly sprayed or added
drop-wise to the polymer powder and lightly mixed to form a uniform
glaze of the wetted polymer. Visual and microscopic observations
will confirm if the candidate coalescing agent can form a coating.
The coating should be formed within about 30 minutes, preferably
less than 5 minutes.
[0009] The coating compositions of the invention can be used to
form a finish on an individual flooring unit. A flooring unit is
defined as sheet vinyl with a defined width and an optional or
indeterminate length, a single uninstalled quarry tile, composite
tile, vinyl tile, wooden flooring component such as pine strips or
oak strips having milled tongue and groove installation components
and other common stone, thermoplastic, linoleum, wood flooring
components, etc. Such flooring units are designed to be delivered
to an installation site and individually installed onto a rough
floor or subfloor surface using adhesive compositions, mastic,
metallic fasteners such as nails, wooden pegs, etc. Such flooring
units are typically used to cover a rough floor or subfloor with a
large number of units to form the final floor surface.
[0010] Each flooring unit can be covered with the compositions of
the invention leaving a uniform continuous coating layer. The
flooring unit can comprise sheet vinyl or an individual flooring
unit that can have an area that range from about 5 to 2000
cm.sup.2, more commonly 10 to 1000 cm.sup.2. The most typical
flooring unit comprises vinyl flooring made in the form of large
rolled sheets with a width of 2 meters to 5 meters and an
indeterminate length, about 5 to 6 cm.sup.2. ceramic tile, a about
15 cm by 15 cm vinyl tile, a quarry tile having dimensions of from
about 200 cm.sup.2 to 1000 cm.sup.2, flooring components having
tongue and groove installation features that can have a width of
from about 2 to about 20 cm and variable length from 25 inches to
350 cm. The surface area of each flooring unit can range from about
5 to about 5000 cm.sup.2., commonly 10 to 4000 cm.sup.2, commonly
20 to 1000 cm.sup.2. When used in forming a coating layer on a
flooring unit, the coalescing agent and the polymer particulate are
typical materials of the invention. However, the coalescing agent
used in a factory formed floor finish on a flooring unit can be of
higher volatility than typical coalescing agents used in field
applications. Factory manufacture of coating units using higher
volatility coalescing agents can involve processes in which the
volatilized coalescing agents are recovered, recycled and reused in
the application rendering the higher volatility less problematic
than their use in field applications. Further, factory application
of the coating compositions on flooring units can involve the use
of relatively high heat flux of incident energy. Such high heat
energy use can result in more rapid coating formation and more
rapid evaporation of the coalescing agent from the finished floor
unit. The use of the methods and compositions of the invention in
coating flooring units involves coating one substantially planar
surface of the flooring unit without applying a coating to an
installation surface of the flooring unit. In other words, the
surface of the flooring unit that is used to attach the flooring
unit either to the rough floor or subfloor or to other flooring
units are preferably not coated with the compositions of the
invention. However, the exposed surface of the flooring unit
obtains a complete continuous uniform coating of the compositions
of the invention.
[0011] The coatings and finishes of the invention appear to the eye
be substantially identical in gross appearance and when
conventionally tested have properties similar to those of the prior
art. In the coatings of the invention, however, the microscopic
structure of the inventive coatings of this invention appears to be
substantially different. In practice, the coating layers can appear
substantially different under cross-sectional microscopic
examination. The prior art coating are typically made with four or
more applications of the liquid coating material forming a layered
structure. This is a result of the limits of the application
methods. Each individual layer has a thickness controlled by the
viscosity of the liquid coating mixture. Useful viscosity materials
require several applications. A coating of this invention is
typically a single uniform layer structure greater than 1 micron,
but typically less than 20 microns in thickness.
[0012] The polymer particulate compositions of the invention are
typically substantially free of liquid organic or aqueous media,
however, the coalescing agent can contain some proportion of water
or solvent but rarely has greater than about 10 wt % water based on
the total amount of coalescing agent. Further, the polymer
particles can contain some water as a matter of impurity or residue
from water based polymerization techniques, however, the amount of
water present in the polymer particulate is typically less than 10
wt % of the total polymer material. Certainly, little or no free or
flowable water is used as an aqueous medium or carrier liquid to
carry either the coalescing agent or the polymer particle onto the
floor surface. For the purpose of this patent application, the term
"floor surface" typically relates to a ceramic, terrazzo, concrete,
quarry tile, vinyl, linoleum, wood composite or other conventional
floor surface material. The compositions of the invention are
typically used to coat a large area of floor in a single step.
Accordingly, the processes of the invention are typically used in
coating more than about 100 cm, preferably more than 0.9 m, most
preferably more than 10 m.sup.2, of floor surface area in a single
step. Typically, the polymer and coalescent can be simultaneously
applied to a surface. the compositions of the invention can also be
applied using devices designed to cover 100 m.sup.2 of floor
surface in a good amount of time. One of ordinary skill in the art
will readily appreciate that the polymer particulate or the
coalescing agent can be distributed over a relatively small or
large area of floor followed by a careful application of the other
part of the two-part coating systems. Such a coating technique is
substantially different than the application of a solvent or
aqueous based medium in which the combined one-part materials are
applied typically using a mop to distribute the combined materials
in a relatively small location in building up a continuous coating
on the floor surface. Lastly, one of ordinary skill in the art will
readily appreciate that there is a substantial difference between
the form of the materials typically considered to be coatings in an
aqueous media or coatings in an organic solvent media when compared
to coating materials of the invention comprising a flowable powder
polymeric composition and a liquid considered to be a coalescing
agent. Solvents typically do not become involved in coalescing
polymer particles into a final coating. Coalescing agents, however,
are comparatively lower in volatility than solvents. Coalescents
are intimately involved in penetrating polymer particles, causing
the polymer to fuse or flow, leaving a coated surface as the
coalescent evaporates. The resulting coating exhibits coverage,
consistency and uniform coating properties. Commonly, solvents or
other liquid carrier media evaporate without causing any important
change in polymer properties. A coalescing agent operates to modify
the polymer properties of a coating system during fusing and
coating formation. A plasticizer is different than a coalescing
agent because after a plasticizer is incorporated into a polymer it
is an essentially permanent part of the formulation. A plasticizer
results in a permanent change in polymer properties including
T.sub.g (glass transition temperature), rheology, tensile strength,
film forming properties, etc. Lastly, the coatings of the invention
are substantially free of aqueous or solvent residue in the coating
layer.
DETAILED DISCUSSION OF THE INVENTION
[0013] The essential components of the compositions and methods of
the invention can be found first in a powder particulate polymer
part and second in a liquid coalescing agent part. The powder
particulate polymer part typically comprises a flowable
substantially dry particulate material made into a composition
having a dimension of from about 3 to about 50 microns, preferably
about 3 to about 15 microns. Often a blended particulate can have
an advantage in friction or appearance. Such a blend can comprise a
particulate with an average particle size of about 25 microns with
a particulate of about 40 microns. The material is typically a dry,
flowable, non-caking particulate. The polymer can be reduced to the
desired particle size by spray drying from an emulsion or milled
from a solid. Typically, the polymer particulate materials of the
invention are prepared by first polymerizing the material using
conventional techniques such as those commonly employed in
aqueous/solvent emulsion polymerization systems. The resulting
product is then spray dried in conventional spray drying equipment
to a dry polymer particle with the desired dimensions. Also, if the
size of the polymer particles need adjusting to a reduced polymer
particle size, the polymer can be comminuted in typical dry
grinding/ball milling technology and then classified into particle
sizes conventionally. The polymer materials are kept dry to a
degree such that the polymer particulate material does not cake,
but retains its free flowing characteristic. The polymer particles
of the invention can be conventional coating polymers and can be
made from a number of useful monomer materials and polymerization
systems.
[0014] One advantage of the invention is that the coating powders
useful in the practice of the invention can be prepared by
non-conventional methods of preparing powders. Many critical
properties of the coatings such as thickness, chargeability,
fluidizing bed pressures, build thicknesses, percent overspray,
etc., are determined by the shape, size, and size distribution of
the powder. Conventional powders result from limited control over
these parameters. The powders of the invention can be made by spray
drying of coating powder composition or spray congealing of an
atomized coating powder composition. The resulting product provides
preferred particles with controlled size and narrow particle size
distributions. These physical properties result in high powder
transfer to a surface or substrate, and in uniform robust
coatings.
[0015] Blends of monomers are used in a balanced ratios to obtain
the desired glass transition temperature, hydrophobic/hydrophilic
qualities, and in particular a desired minimum film forming
temperature. Suitable monomers include methyl acrylate, ethyl
acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate,
isobutyl acrylate, sec-butyl acrylate, n-amyl acrylate, isoamyl
acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl
acrylate, 3,5,5-trimethylhexyl acrylate, n-decyl acrylate,
n-dodecyl acrylate, isotridecyl acrylate, cetyl acrylate, octadecyl
acrylate and n-butoxyethyl acrylate. Further n-amyl methacrylate,
isoamyl methacrylate, n-hexyl methacrylate, 2-ethylbutyl
methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate,
3,5,5-trimethylhexyl methacrylate, n-decyl methacrylate, n-dodecyl
methacrylate, isotridecyl methacrylate, octadecyl methacrylate and
butoxyethyl methacrylate, can be used. Further, tert-butyl acrylate
or methacrylate, tert-amyl acrylate or methacrylate,
1,1-dimethylbutyl acrylate or methacrylate and 1,1-dimethylhexyl
acrylate or methacrylate. Further, isobornyl acrylate or
methacrylate, cyclohexyl acrylate or methacrylate, benzyl acrylate
or methacrylate, and phenyl acrylate or methacrylate can be used.
Further, methyl methacrylate, but also ethyl methacrylate, n-propyl
methacrylate, isopropyl methacrylate, n-butyl methacrylate,
isobutyl methacrylate and sec-butyl methacrylate can be used.
Further, vinyl formate, vinyl acetate, vinyl propionate, vinyl
butyrate, vinyl hexanoate, vinyl octanoate and vinyl
2-ethylhexanoate can be used. Further, styrene,
.alpha.-methylstyrene,2-, 3- or 4-vinyltoluene, 2,4-dimethylstyrene
and 1-phenylpropene. Further, acrylic acid, methacrylic acid,
crotonic acid, itaconic acid, citraconic acid, fumaric acid, maleic
acid and maleic anhydride. Of these, acrylic acid and methacrylic
acid are particularly suitable. Multifunctional hydrophilic
monomers having at least one further functional group are monomers
with amido groups, including N-substituted derivatives, such as
alkoxyalkylamido- and alkylolamido(meth)acrylates,
(meth)acrylamidoglycolic acid and esters and/or ethers thereof,
with further olefinic double bonds, for example divinylbenzene,
butanediol di(meth)acrylate or (meth)allyl(meth)acrylate, and with
hydroxyl, amino, epoxy, oxazolinidyl, oxazinyl or ureido groups in
the side chain. In an emulsion component, the cation M.sup.+ is
preferably ammonium potassium or in particular sodium, but may also
be lithium, trimethylammonium, triethylammonium,
tri-n-butylammonium, tetra-n-butylammonium, triethanolammonium or
triisopropanolammonium. Multifunctional monomers can be employed to
crosslink polymer chains either through irreversible covalent
bonding or through reversible coupling with divalent, trivalent,
etc. metal ions. The polyvalent metal compound, if employed in the
coatings, may be either a metal complex or a metal chelate. The
polyvalent metal ions may be those of beryllium, cadmium, copper,
calcium, magnesium, zinc, zirconium, barium, strontium, aluminum,
bismuth, antimony, silver, lead, cobalt, iron, nickel or any other
polyvalent metal or mixture thereof which can be added to the
composition by means of an oxide, hydroxide, or basic, acidic, or
neutral salt or complex or clathrate thereof which has appreciable
solubility in water, such as at least about 1% by weight therein.
The selection of polyvalent metal and the anion are governed by the
solubility of the resultant meal complex in order. Zinc and cadmium
are particularly preferred polyvalent metal ions. The ammonia and
amine complexes (and especially those coordinated with NH.sub.3) of
these metals are particularly useful. Amines capable of so
complexing include morpholine, monoethanol amine,
diethylaminoethanol, and ethylenediamine. Polyvalent metal
complexes (salts) or organic acids that are capable of
solubilization in an alkaline pH range may also be employed. Such
anions as acetate, glutamates, formate, carbonate, salicylate,
glycollate, octoate, benzoate, gluconate, oxalate and lactate are
satisfactory. Polyvalent metal chelates where ligand is a bidentate
amino acid such as glycine or alanine may also be employed. The
polyvalent metal compound must be such that the metal is available
to serve its crosslinking function, i.e., it is dissociable to form
polyvalent metal-containing ions. Preferred polyvalent metal
compounds, complexes and chelates include zinc acetate, cadmium
acetate, zinc glycinate, cadmium glycinate, zinc carbonate, cadmium
carbonate, zinc benzoate, zinc salicylate, zinc glycollate and
cadmium glycollate. Although the polyvalent metal compound may be
added to the polish composition in dry form such as a powder, it is
preferred to first solubilize the polyvalent metal compound using a
fugitive ligand such as ammonia. For purposes of this invention a
ligand is considered fugitive if at least a portion of said ligand
tends to volatilize under normal film forming conditions. Since the
ammonia may complex with the polyvalent metal compound, a compound
such as zinc glycinate, when solubilized in dilute aqueous ammonia
solution, may be named zinc amine glycinate.
[0016] The polyvalent metal compound when used is employed in an
amount so that the ratio of polyvalent metal to the
.alpha.,.beta.-ethylenically unsaturated acid of the addition
polymer varies from about 0.05 to 0.5, and preferably from about
0.2 to 0.3. This is expressed as the ratio of metal, such as
Zn.sup.++, to --COOH or --COONH4 groups, a ratio of 0.5 being
stoichiometric.
[0017] The polymer particulate materials of the invention can be
formulated in a particle having a dimension of from 3 to 50
microns, or other preferred particle size as are discussed herein,
with other compatible materials that aid in coating, film or finish
formation and/or characteristics. Such ingredients include
cooperative polymer materials, plasticizers, waxes, small amounts
of solvents or liquids that aid in particle formation but do not
act as liquid media. The compositions can also include biocides,
gloss agents, deglossing agents, matte forming agents, friction
(TiO.sub.2, silica or other COF additives) modifiers and other
additives common in coating formulations. Typical particulate
formulations for the coating polymer is set forth in the following
table. Further blending polymers with different T.sub.g can have
useful properties. Relatively higher T.sub.g polymers can aid in
forming regions of increased friction on the coating surface.
Clearly film forming materials can be combined with both film
forming and non-film forming materials. These materials can have a
variety of particle sizes depending on desired properties.
1 Particulate Polymer for Coatings Particulate Useful Preferred
Most preferred Composition Wt.-% Wt.-% Wt.-% Acrylic polymer 0 to
80 5 to 75 10 to 60 Urethane polymer 0 to 80 5 to 75 10 to 60
Plasticizer 0.1 to 35 0.5 to 30 1 to 25 Wax 0.1 to 15 0.2 to 12 0.1
to 10 Resin Additive(s) 0 to 15 0.1 to 12 0.2 to 15
[0018] Some polymers which would be useful are 60/40 MMA/MA,
55/40/5, MMA/MA/DMAM, 70/30 MMA/EA, 80/20 MMA/BA, 60/40 MMA/2EHA,
75/25 EMA/MA, 90/10 EMA/EA, 50/50 MMA/BMA, 88.5/715.5/88.5
MAA/Sty/AA, 60/39/1 MMA/MA/MAA, 34/28/25/5/8 MMA/BA/Sty/AN/MAA;
wherein AA=Acrylic acid, MMA=Methyl methacrylate, MA=Methyl
acrylate, EA=Ethyl acrylate, EMA=Ethyl methacrylate,
AN=acrylonitrile, Sty=Styrene BA=Butyl acrylate, 2EHA=2-Ethylhexyl
acrylate, BMA=Butyl ethacrylate, DMAM =Dimethylaminoethyl
methacrylate and MAA=Methacrylic acid. Other Polymers include
cellulosic types including cellulose acetate phthalate (CAP),
cellulose acetate trimellitate (CAT), hydroxypropylmethyl cellulose
phthalate (HPMCP), hydroxy propylmethyl cellulose acetate succinate
(HPMCAS) and carboxymethylethyl cellulose (CMEC) vinyl types
including polyvinyl alcohol acetate phthalate (PVAP) acryl types
including copolymers of methacrylic acid and ethyl acrylate are
used. Further, hydroxypropyl methylcellulose phthalate, cellulose
acetate phthalate, methyl methacrylate/methacrylic acid copolymer,
polyvinyl acetate phthalate, carboxymethyl ethylcellulose,
polyvinyl alcohol phthalate, starch acetate phthalate cellulose
acetate succinate, styrene/maleic acid copolymer, polyvinyl acetyl
diethylaminoacetate, poly(dimethylaminoethyl methacrylate),
benzylaminomethylcellulose, diethylaminomethylcellulose,
benzylaminoethyl hydroxyethylcellulose, cellulose acetate
diethylaminoacetate, cellulose acetate dibutylaminohydroxypropyl
ether, sodium carboxymethylcellulose, methylcellulose,
hydroxyethylcellulose, polyvinyl alcohol, gelatin,
polyvinylpyrrolidone, pyrrolidone/vinyl acetate copolymer,
polyethylene glycol, hydroxypropyl methylcellulose,
hydroxypropylcellulose, vinylpyrrolidone/vinyl acetate copolymer,
ethylcellulose, methylvinylpyridine/methyl acrylate methacrylate
copolymer, acetylcellulose, nitrocellulose, polyvinyl acetate,
shellac and mixtures of two or more thereof are useful.
[0019] Blends of the addition copolymers may be used. The polymers
may also be graft copolymers including grafts of the monomers
mentioned on shellac. The copolymer containing acid groups may be
soluble or dispersible in aqueous alkaline media having a pH from
7.0 to 11, usually at least 7.5, and preferably from about 8.0 to
9.5, the pH being adjusted to achieve a water clear appearance.
[0020] The second necessary component, a coalescing agent or
coalescent, is necessary in the production of a coherent film layer
from the polymer particles. The fugitive coalescent agent enables
or promotes the film forming characteristics of the polymer
particles in the coating compositions. The term fugitive means the
material eventually evaporates or escapes the coating during or
after film formation. Some small proportion of coalescent residue
can remain in the layer. The fugitive material which are preferred
are at least partially water soluble higher boiling (about
150.degree. to 200.degree. C.) monohydric and polyhydric alcohols;
and monoalkyl and dialkyl ethers of glycols, diglycols ether
alcohols, and polyglycols where alkyl is straight or branched and
has from 1 to 5 carbon atoms. Examples of such fugitive materials
include diglyme, 2-butoxyethanol, 3-methoxybutanol-1, the
monomethyl, monoethyl and monobutyl ether of diethyleneglycol,
dipropylene glycol or polypropylene glycols, ethylene glycol,
propylene glycol and polypropylene glycols. An evaporative
coalescent temporarily reduces the film formation temperature and
softens the polymer particulate. This allows the particles to fuse
and form a continuous film layer. The final properties of the
polymer film layer are established or expressed as the coalescent
evaporates from the particles. Additional energy could be added to
the coating to aid in the removal of the coalescing agent. The
coalescent is used with the polymer at an amount of about 0.2 to 2
or about 0.5 to 1 part by weight of the coalescent for each part of
the polymer. Additive materials can be added to the coalescent
liquid to enhance the coalescent action. Such additives reduce
surface tension at the particle coalescent interface. Such
materials may include minor amounts of low molecular weight or
lower (a C.sub.1-6 linear or branched alcohol) or a surfactant.
[0021] A wide variety of materials capable of performing the
aforementioned role in the film formation process. Some examples of
liquids used in conjunction with acrylic based polymers include but
are not limited to glycol ethers or ether alcohols, mono alkyl
ether alcohols, etc. including diethylene glycol C.sub.1-6 mono- or
dialkyl ether, diethylene glycol ethyl ether, diethylene glycol
butyl ether, dipropylene glycol methyl ether, tripropylene glycol
ethyl ether, propylene glycol ethyl ether, glycol ether,
triethylene glycol ethyl ether, etc. selected other coalescents can
include texanol (isobutyrate), benzyl alcohol, 3-methoxybutanol-1.
Examples of low volatility fugitive coalescents include the
monomethyl, monoethyl and monobutyl ethers of diethylene glycol,
triethylene glycol, dipropylene glycol and tripropylene glycol and
also benzyl alcohol, isophorone and methoxybutanol.
[0022] A wide variety of materials can be used as a plasticizer.
Any material that reduces the glass transition temperature can be
defined as plasticizer. Plasticizers can enhance the properties of
the polymer films and to ease their film formation. A plasticizer
incorporates itself into the polymer matrix and permanently reduces
the polymer's glass transition temperature. This obtains a
reduction in the polymer hardness and an increase in the polymer
flexibility. The plasticizer also aids in the film formation
process. While permanent plasticizers are not necessary in the film
formation process plasticizers can provide useful properties. The
polymer materials of the invention can be combined with
plasticizers in a variety of ways. When the polymeric materials are
spray dried, the polymers can be combined with plasticizers in the
aqueous or solvent form solution prior to spray drying. During
spray drying, the permanent plasticizers can combine with the
polymers in the final flow of particles. Alternatively, the
plasticizer can be added to the polymer particles during
comminution or during milling prior to classification of the
polymer/plasticizer composition into the correct particle size.
Other ways of combining plasticizer and polymer are known in the
art and can be used to result in a combined polymer plasticizer
flowable particle. Examples of non-fugitive permanent plasticizers
are pure or mixed diesters of phthalic acid with benzyl alcohol,
butanol, hexanol, 2-ethylhexanol, cyclohexanol or octanol as
alcohol component, pure or mixed benzoic and fatty esters of
monohydric or polyhydric alcohols such as pentaerythritol, glycols
and propylene glycols. Examples are polypropylene glycol adipate
benzoate, diethylene glycol dibenzoate, dibenzyl sebacate, acetyl
tributyl citrate and butyl phthalate-butyl glycolate. A
structurally different group are triphenyl phosphate, tributyl
phosphate and tributyoxyethyl phosphate. Tributoxyethyl phosphate
is frequently also used as flow control agent.
[0023] Waxes are often used in conjunction with a polymer in the
production of polymer films used as floor finishes. However, they
are not a necessary component. They can serve a few purposes in a
polymer film. Among these are modifications in the film durability,
the buffability, the reparability, and the coefficient of friction.
Waxes are oftentimes added to surface coatings. This is
particularly true of acrylic floor finishes. In floor finish
formulations, the emulsified wax should be added to the base
polymer prior to drying to solid. In the case of acrylic floor
finishes, the emulsified wax should be mixed with the acrylic latex
and then spray dried. The resulting dry polymer is comprised of
both wax and acrylic polymer. One could also envision the addition
of wax along with the coalescing fluid. Furthermore, the addition
of more liquid would result in longer cure times and therefore is
not the preferred embodiment. It is important that the wax remain
as discrete particles in the film. It is that discrete particle
character that manifests itself in film's properties. In the
compositions of the present invention, the relative proportions of
the polymer to wax are from 100:0 to 30:70 by weight. The variation
in these relative proportions provides for various buffing
characteristics. The wax used may be either natural or synthetic
and of vegetable, animal or mineral origin and should have a
melting point of at least 75.degree. C. and preferably of at least
82.degree. C. Some examples of these waxes include both high and
low density polyethylene and polypropylene waxes, carnuba, montan,
palm waxes, Chinese insect, ceresin, azocerite, microcrystalline
waxes, Fisher-Tropsch wax. Mixtures of the waxes may be used. Waxes
of lower melting points should not be used as the sole wax
component, but can be blended with higher melting point waxes such
that the aggregate melting point is about 75.degree. C.
[0024] An alkali soluble resin may aid in film formation in floor
finishes. These usually acid-functional resins may if desired also
be used in a partially neutralized form. In floor finish
formulations of the invention, the resin should be added to the
base polymer prior to drying to solid. This is the preferred
embodiment. The resulting polymer is comprised of both the base
polymer and the resin. Examples of such alkali soluble resins are
shellac, Manilla gun, Loba gum and alkali soluble alkyd resins
which essentially represent polyesters of aliphatic dicarboxylic
acids with aliphatic polyhydric alcohols, which may be modified
with a C.sub.8-C.sub.18-fatty acid, glycerol esters of
C.sub.8-C.sub.18-fatty acids and resin acids, for example abietic
acid or rosin. But it is particularly advantageous to use addition
copolymers of olefinically unsaturated acids and aromatic vinyl
compounds, for example copolymers of acrylic acid, methacrylic acid
and/or maleic anhydride with styrene.
[0025] In the methods of the invention, the coatings are made by
combining the polymer particulate with a coalescing liquid agent at
preferred proportions. Since certain agents are more or less
effective as a coalescing agent, there is a broad range of
proportions useful in the invention that can result in the
formation of an excellent coating of beneficial properties. The
coatings of the invention can be formed on flooring materials at a
floor manufacturing plant. In such a process, flooring units, such
as a vinyl tile, ceramic tile, milled oak or pine board, etc. can
be coated as described in this application. Onto the tile unit or
wood flooring unit is placed typically simultaneously the
particulate and coalescing agent of the invention. As described
above, the polymer particle or the coalescing agent can be
separately added. The coalescing agent is permitted to form the
continuous finish layer during processing. The coalescing agent is
typically removed by evaporation during the operations or
immediately thereafter. In a flooring manufacturing location,
additional energy can be applied to the flooring to speed
coalescing agent removal. Typical factory applications permit the
use of higher VOC coalescing agents. Such agents can be
substantially recovered in recovery systems after evaporation and
recycled. The ratio of combining the polymer with a coalescing
agent are shown in the following table of coating systems.
2 Coating Systems Useful Preferred Most Range - Range Preferred
Composition Nature (wt./wt.) (wt./wt.) (wt./wt.) Polymer
particulate 1 1 1 Coalescing agent liquid 0.1 to 2 0.2 to 1 0.5 to
1
Experimental Section
[0026] The following coating examples highlight the coating
formation characteristics of the compositions of the invention. We
have provided a number of examples that illustrate the spirit of
the invention using three different acrylic based polymers, a
cellulosic polymer and a number of different coalescing agents. The
coatings exhibit useful hardness, uniformity, resiliency,
integrity, durability, and flexibility. The coatings in the
examples are evaluated for gloss. Gloss provides an indication of
proper film formation. A discussion of the results of scanning
electron microscopy (SEM) analysis of the coatings are also
included. The SEM analysis is used to confirm coherent film
formation. Examples using three conventional Rohm & Haas
polymeric coating compositions other coating agents and differing
coalescing agents are provided. The examples include the coating of
glass microscopic slides, ceramic tile, and vinyl composite
tile.
EXAMPLE 1
[0027] The polymer used was a non-crosslinked Rohm & Haas UHS
plus product. The polymer was spray dried from an aqueous latex to
a dry flowable powder with a mean particle diameter of
approximately 7 .mu.M. The coalescing agent was a mixture of
isopropanol (10 wt.-%) in diethylene glycol monoethyl ether.
[0028] Coatings were formed on the surface of a 1".times.3"
microscopic glass slide A pump-up aerosol liquid spray bottle was
used to deliver a uniform spray of the coalescing agent on the
slide. Onto the slide surface, distributed evenly on the glass, was
placed 0.005 grams of the spray dried polymer particulate. About
equal proportions of the coalescing agent was briefly sprayed onto
the polymer coated glass surface. The polymer and coalescent system
was allowed to stand alone and begin the film formation process for
approximately 30 seconds. After the initial 30 seconds, a visible
glaze was spread evenly over the surface. The final coating was
uniform and glossy.
[0029] Microscopic observations were conducted with a 200.times.
Nikon Optiphax-PDL Optical Microscope. Microscopic Observations
included excellent film formation observed under 200.times.
magnification. No original particle definition is observable in the
film. This observation suggests that a tight and coherent film has
been formed. A scrape across the surface of the coated slide
reveals that the coating layer is consistent throughout the surface
of the slide. The film looks nearly identical to the slides
produced from conventional aqueous acrylic latex materials. Visual
Observations of the gross coating showed that the coating is
transparent and glossy. The surface appears to be coated
evenly.
EXAMPLE 2
[0030] The polymer used was a mixture of the composition listed in
Table No. 1. The mixture was diluted with water and then spray
dried to mean particle diameter of approximately 10 .mu.M.
3TABLE 1 Order of Addition Coating Component Amount wt % 1 Conrez
polymer (25 wt % solids) 4.7 2 Tributoxy ethyl phosphate 2.4 3
Dibutyl phthalate 3.1 4 NT-2624 Acrylic polymer 77.9 (38 wt %
solids) 5 AC-325 polyethylene wax 5.9 6 E-43 Polypropylene wax
6.1
[0031] The coalescing agent used was 100% diethylene glycol
monobutyl ether (Butyl Carbitol). The procedure was substantially
the same as that in Example 1. In the microscopic observations, we
observed that the level of film formation, under 200.times.
magnification, is good. The surface appears completely covered with
polymer coating and no original particle definition can be observed
suggesting that a tight and coherent film has been formed. Ridges
are observable in the film layer, the ridges are most likely the
result of the spreading of the glaze over the surface A scrape
across the surface of the coated slide reveals that the polymer
covers the entire surface of the slide. Visual Observations of the
coating revealed that the coating is uniform, transparent and
glossy. There is some noticeable diffraction/light scattering that
most likely results from the ridges. There is no noticeable haze in
the film.
EXAMPLE 3
[0032] The polymer used was a latex of the Rohm & Haas Rhoplex
NTS-2923 acrylic polymer that was allowed to air dry into a solid
polymer. The solid polymer was crushed to a fine powder with a
mortar and pestle. The Coalescing Agent was 100% diethylene glycol
monobutyl ether (tradename Butyl Carbitol). The surface of a 1" by
3" microscopic glass slide was covered. The crushed polymer powder
(0.005 gram) was sieved onto the glass surface through a 20 .mu.M
screen. The coalescing agent then was briefly sprayed onto the
polymer coated glass surface. The polymer/coalescent system was
allowed to stand alone and begin the film formation process for
approximately 30 seconds. After the initial 30 seconds, the glaze
was spread evenly over the surface. Microscopic Observations were
made through a 200.times. Optical Microscope. The surface appeared
glossy and was completely covered with polymer, this suggests that
a tight and coherent film has been formed. Some particle definition
can be observed, this results from some incomplete film formation
in some of the particles. The observed level of film formation,
under 200.times. magnification, was possibly be the result of the
larger, crushed particles used. A scrape across the surface of the
coated slide reveals that the coating layer is consistent
throughout the surface of the slide. Visual Observations with
naked/unassisted eye revealed that the coating is transparent and
glossy. The surface appears to be coated evenly, with no evidence
of the method of application visible. Some "orange peeling"/light
scattering is observable--most likely results from some of the
imperfections noted under magnification. The coating appears to be
continuous, coherent and substantially uniform but has some minor
surface depressions or dimples resulting from polymer flow. Such
surface features do not interrupt coating formation.
EXAMPLE 4
[0033] The polymer used was a non-crosslinked version of the Rohm
& Haas UHS Plus polymer. The polymer was spray dried from an
aqueous emulsion to a mean particle diameter of approximately 7
.mu.M. The coalescing Agent was 100% diethylene glycol monoethyl
ether (tradename Carbitol). The surface Coated was a 1 foot by 1
foot black ceramic tile. The application procedure was an
application of 0.5 grams of the spray dried polymer distributed
evenly on the ceramic tile followed by the spraying of the
coalescing agent onto the polymer coated ceramic surface. The
polymer/coalescent system was allowed to stand alone and begin the
film formation process for approximately 30 seconds. After the
initial 30 seconds, the glaze was spread evenly over the surface.
Visual Observations made with the naked/unassisted eye included a
coated surface that appeared clear and glossy. No noticeable orange
peeling or particle definition formed in the surface. The coating
looks like the coatings derived from aqueous latex acrylics. The
surface appeared to be coated evenly with no evidence of the method
of application.
EXAMPLE 5
[0034] The polymer used was a non-crosslinked Rohm & Haas UHS
Plus polymer. The polymer was spray dried from an aqueous emulsion
and processed to a mean particle diameter of approximately 7 .mu.M.
Isopropanol (IPA wetting agent) at 10 wt %, in diethylene glycol
monoethyl ether (tradename Carbitol) was used as a coalescent. The
surface Coated was a 1 foot by 1 foot black vinyl composition tile.
Approximately 0.5 grams of the spray dried polymer was distributed
evenly on the vinyl tile. The coalescing agent was briefly sprayed
onto the polymer coated vinyl surface. The polymer/coalescent
system was allowed to stand alone and begin the film formation
process for approximately 30 seconds. After the initial 30 seconds,
the glaze was spread evenly over the surface. Visual Observations
with the naked/unassisted eye showed that the coated surface
appeared clear and glossy with no noticeable "orange peeling" or
particle definition. The coating looks like the coatings derived
from aqueous latex acrylics. The surface appears to be coated
evenly, there is no evidence of the method of application.
EXAMPLE 6
[0035] The polymer used was a mixture of the composition listed in
Table No. 2. The mixture was diluted with water and then spray
dried to mean particle diameter of approximately 10 .mu.M.
4TABLE 2 Order of Addition Coating Component Amount wt % 1 Conrez
polymer (25 wt % solids) 4.7 2 KP-140 Plasticizer 2.4 3 Dibutyl
Phthalate 3.1 4 38% NT-2624 Acrylic Polymer 77.9 (38 wt % solids) 5
AC-325 polyethylene wax 5.9 6 E-43 Polypropylene wax 6.1
[0036] The coalescing agent was diethylene glycol monoethyl ether
(tradename Carbitol). The surface coated was a 1 foot by 1 foot
black vinyl composition tile. Approximately 0.5 grams of the spray
dried polymer distributed evenly on the vinyl tile. The coalescing
agent was sprayed onto the polymer coated vinyl surface. The
polymer/coalescent system was allowed to stand alone and begin the
film formation process for approximately 30 seconds. After the
initial 30 seconds, the glaze was spread evenly over the surface.
Visual observations with the naked/unassisted eye revealed that the
coated surface appears hazy and of a matte finish. There is no
noticeable orange peeling or particle definition to be seen. The
surface is streaked with regions of greater haze and the method of
application is noticeable. The coating appears to cover the entire
surface area.
EXAMPLE 7
[0037] Using the method of the previous examples solid sodium
carboxymethylcellulose from Aqualon was crushed to a fine powder
with a mortar and pestle. The coalescing agent was 40% by weight
ethyl alcohol in water The surface coated was a 1" by 3"
microscopic glass slide. About 0.005 grams of the crushed polymer
powder sieved was onto the glass surface through a 20 .mu.M screen.
The coalescing agent was sprayed onto the polymer coated glass
surface. After a few seconds, the resulting glaze was spread over
the slide surface. Microscopic observations revealed that the level
film formation was good. The surface appears completely covered
with polymer, this suggests that a tight and coherent film has been
formed. A scrape across the surface of the coated slide reveals
that the coating layer is consistent throughout the surface of the
slide. Visual Observations using the naked/unassisted eye revealed
a coating that was transparent and glossy.
SEM Evaluation
[0038] Scanning Electron Microscope (SEM) observations of coated
glass slides were made to compare coatings. Polymer films similar
to those of Example 1 were compared with coatings produced with
conventional aqueous emulsions finishes.
[0039] Slide Preparation/composition for SEM Evaluation
[0040] Slide No. 1:
[0041] Conventional control coating. A 1" by 3" glass slide was
coated with conventional floor finish and allowed to cure on the
slide.
[0042] Slide No. 2:
[0043] A coated Slide was made using the coating in Example No. 1.
A 1" by 3" glass slide was coated from particles with the 7 .mu.M
non-crosslinked UHS Plus polymer particles. Diethylene glycol
mono-ethyl ether was used as the coalescent. The polymer particles
were allowed to coalesce and cure on the slide.
[0044] Slide No. 3:
[0045] Example No. 2 coating material. A 1" by 3 " glass slide was
coated from particles with the 10 .mu.M polymer particles described
in Example No. 2. Diethylene glycol mono-ethyl ether (Carbitol) was
used as the coalescent. The polymer particles were allowed to
coalesce and cure on the slide.
[0046] Slide No.4:
[0047] Aqueous Example No.2 Material Coated Slide A 1" by 3" glass
slide was coated with an aqueous emulsion of the material described
in Example No. 2. The Carbitol coalescent was then sprayed on the
liquid emulsion and mixed. The liquid was allowed to cure on the
slide. This slide was prepared as a control for the third SEM
slide.
[0048] SEM Observations: Gold Coated Image
[0049] Slide No. 1:
[0050] The conventional control coating, at 3000.times.
magnification, forms a surface that is smooth and there is no
visible particle definition. This suggests that the particles form
into a tight film layer. There are sporadic dimples in the surface.
The dimples seem to be no bigger than 1 .mu.M in diameter
[0051] Slide No. 2:
[0052] Example No. 1 Material There is quite a bit of variation in
the coating under 3000.times. magnification. Original particle
definition cannot be observed in any area of the slide. This
suggests that the particles coalesced into a tight film layer.
[0053] Slide No. 3:
[0054] Example No. 2 Material At 3000.times. magnification, the
surface is smooth and there is no visible original particle
definition. This suggests that the particles coalesced into a tight
film layer. There are sporadic dimples in the surface. The dimples
are seem to be no bigger than 1 .mu.M in diameter and seem similar
to the ones noted in slide No. 1.
[0055] Slide No. 4:
[0056] Aqueous Example No 2 Material Coated Slide. At 3000.times.
magnification, no original particle definition can be noted. This
suggests that the particles coalesced into a tight film layer.
[0057] The analysis seems to have proven that the coating particles
of the invention have coalesced into a coherent and tight film.
Evidence for this conclusion can be drawn from the lack of visible
original particle definition. Improper film formation observable as
visible faults between particles having a mean diameter of greater
than around 20 .mu.M, was not seen.
[0058] The coatings of the invention can be modified using coatings
technology to incorporate useful properties into the coatings. The
coatings can be antimicrobial, protective, antistatic, removable,
have high coefficients of surface friction, act as biocidal films
against the growth of adventitious organisms such as barnacles and
zebra mussels, removable systems that act as cleaners by enveloping
or incorporating dirty layers that are removed along with the
coatings, can act as medical coatings for skin and medical devices
and protective coatings for optical structures. In this regard,
antibacterial antifungal properties of the films can be enhanced
using metal additives such as manganese or copper, titanium
dioxide, silver or organic antimicrobial materials such as quats,
hexachlorophene and others. GRAS materials can be used in the
manufacture of coatings for foods such as plants, stems, leaves,
fruits and others. Specialized coatings developed for particular
locations such as food surfaces, dairies, electronic factories,
greenhouses, kitchens, nursing homes, hospitals, surgical theaters,
hotel rooms, bathrooms, factory floors, ceramic or polyester
containers, car surfaces and other known surfaces. Specific
products envisioned include antifouling coatings for ships,
preservative coatings for woods, metal coatings for food processing
equipment, antistatic surfaces for electronic equipment and
explosive environments, graffiti resistant coatings for municipal
environment, grass, food coatings, stain resistant coatings and
others.
[0059] The above specification example and data fully explain the
operations of the floor finish compositions and methods. The
invention can have a variety of embodiments and applications
without departing from the spirit and scope of the invention. The
invention resides in the claims hereinafter appended.
* * * * *