Field of the Invention
[0001] The present invention relates to release coatings. In particular, the present invention
relates to release coatings which anchor toner.
Background of the Invention
[0002] A number of conventional electrophotoconductive devices such as printers and copiers
employ dry toner. These printers and/or copiers employ toner to form a latent image
transferable from an imaging device to a substrate such as paper, tag or label stock.
The toned latent image is then subjected to heat fusing in order to obtain the best
print quality and toned image density.
[0003] Although the resulting images are often of good quality, there are problems associated
with the imaging processes employed by printers and/or copiers. For example, there
is the problem of backgrounding which is the accumulation of various unwanted materials
such as toner particles on the substrate. Backgrounding can occur when the imaging
device evenly disperses toner particles over a non-imaged area of the substrate.
[0004] Additional backgrounding problems can be experienced when label stock is utilized.
Label stock comprises one or more non-continuous substrates referred to as labels
which are adhered by an adhesive to a protective backing or liner. To permit the label
to be removed from the protective liner, it is customary to coat a release coating
over the liner in order to permit ready separation of the two members.
[0005] Although the release coating permits ready separation, detrimental backgrounding
problems can be experienced when a partially used sheet of label stock is repassed
through an electrophotoconductive printing device. Usually after the first printing,
one or more labels are removed thereby exposing the release coating. Thus, backgrounding
occurs not only on the label, but also upon exposed release coating. The toner will
not anchor to conventional silicone release coatings due to the fact that these coatings
have a different polarity than do the toner particles and because the silicone coatings
have much lower glass transition temperatures than the toner particles. Therefore,
the unwanted particles which are dispersed on the release coating tend to flake off
the coating, then transfer to rollers found in printers and then possibly, relocate
themselves to the succeeding labels or sheets.
[0006] World Patent Application No. US/90/03286 (Josephy et al.) describes a toner receptive
coating which can be applied to compressible substrates such as paper. Similarly,
U.S. Patent No. 4,492,410 (Fitch et al.) describes a toner receptive coating applied
to substrates such as paper. However, neither of these two references teach the use
of a release coating which can also anchor toner particles.
[0007] Thus, there currently exists a need for a release coating which will anchor toner
particles and yet, maintains good release properties for substrates such as labels.
Summary of the Invention
[0008] The present invention comprises a release coating which is capable of anchoring toner
particles emitted by electrophotoconductive devices and yet, maintains good release
properties. The release coating of the present invention is coated onto a liner over
which one or more substrates such as labels can be applied. The coating comprises
a polymer having at least one vinyl polymeric segment having a Tg between -10°C and
65°C and at least one siloxane polymeric segment. Preferably, the T
g should be between 20°C and 45°C of the vinyl polymer segment.
[0009] In one embodiment of the present invention, the coating is a copolymer which comprises
the formula:

wherein
- R₁
- are monovalent moieties which can independently be the same or different and are selected
from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, hydroxyl, hydrogen,
and fluoroalkyl;
- R₂
- can independently be the same or different and are divalent linking groups;
- R₃
- are monovalent moieties which can independently be the same or different and are selected
from the group consisting of alkyl, aryl, alkylaryl, alkoxy, alkylamino, hydroxyl,
hydrogen, and fluoroalkyl;
- R₄
- can independently be the same or different and are divalent linking groups;
- x
- is an integer of 0 to 3;
- y
- is an integer of 10 or greater;
- q
- is an integer of 0 to 3;
G₅ and G₆ are monovalent moieties which can independently be the same or different
selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoralkyl,
hydrogen, and -WSA wherein W is a divalent linking group and A is defined below; and
G₂ and G₄ are A wherein A is a vinyl polymeric segment or block consisting essentially
of a polymerized free radically polymerized monomer.
[0010] In another embodiment of the present invention, the coating comprises a copolymer
of D and E monomers copolymerized to form a polymeric backbone with F monomer grafted
thereto wherein:
- D
- is at least one free radically polymerizable vinyl monomer;
- E
- is at least one polar monomer copolymerizable with D, the amount of E being up to
30% of the total weight of all monomers, and
- F
- is a monomer having the general formula X-(Y)nSiR(3-m)Zm wherein
X is a vinyl group copolymerizable with the D and E monomers,
Y is a divalent linking group where n is zero or 1;
m is an integer of 1 to 3;
R is hydrogen, lower alkyl (e.g., methyl, ethyl, or propyl), aryl (e.g., phenyl or
substituted phenyl), or alkoxy groups; and
Z is a monovalent siloxane polymeric moiety having a number average molecular weight
above about 1,000 and is essentially unreactive under copolymerization conditions.
[0011] The present invention also includes a toner receptive article comprising a liner,
a release coating and a substrate such as a label mounted over the liner.
Drawings
[0012] Fig. 1 is a representation of an embodiment of Applicants' invention tested in accordance
with the procedures described below.
[0013] Fig. 2 is a representation of Avery 30-up stock #5160 which has been tested in accordance
with the procedures described below.
Detailed Description
[0014] The present invention includes a release coating which is capable of anchoring toner.
The release coating has at least one siloxane polymeric segment and at least one vinyl
polymeric segment having a T
g between -10°C and 65°C. By virtue of its chemical composition and structure and the
resultant properties, the release coating is well-suited to control toner anchorage
applications. In particular, it is thought that the silicone segment presents a low
energy, "siliconized" release surface and the higher energy vinyl polymeric segment
provides the adhesion for the toner particles.
[0015] In one embodiment of the present invention, the coating is a copolymer which comprises
the formula:

[0016] R₁ are monovalent moieties which can independently be the same or different which
are selected from the group consisting of alkyl, aryl, alkylaryl, alkoxy, alkylamino,
hydroxyl, fluoroalkyl, and hydrogen. Preferably, R₁ are monovalent moieties which
can independently be the same or different selected from the group consisting of C₁₋₄
alkyl and hydroxyl. Most preferably, R₁ is selected from the group consisting of methyl
and butyl.
[0017] R₂ are divalent linking groups which can independently be the same or different.
Suitable divalent linking groups include but are not limited to the following: C₁
to C₁₀ alkylene, arylene, alkylarylene and alkoxyalkylene. Preferably, R₂ is selected
from the group consisting of C₁₋₃ alkylene and C₇-C₁₀ alkylarylene due to ease of
synthesis of the compound. Most preferably, R₂ is selected from the group consisting
of -CH₂- ; 1,3-propylene; and

R₃ are monovalent moieties which can independently be the same or different which
are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino,
hydroxyl and fluoroalkyl, and hydrogen. Preferably, R₃ are monovalent moieties which
can independently be the same or different selected from the group consisting of C₁₋₄
alkyl and hydroxyl. Most preferably, R₃ is selected from the group consisting of methyl
and butyl.
[0018] R₄ are divalent linking groups which can independently be the same or different.
Suitable divalent linking groups include but are not limited to the following: C₁
to C₁₀ alkylene, arylene, alkylarylene and alkoxyalkylene. Preferably, R₄ is selected
from the group consisting of C₁₋₃ alkylene and C₇-C₁₀ alkylarylene for reasons of
ease of synthesis. Most preferably, R₄ is selected from the group consisting of -CH₂-;
1,3-propylene; and

G₅ and G₆ are monovalent moieties which can independently be the same or different
selected from the group consisting of alkyl, aryl, alkylaryl, alkoxy, alkylamino,
fluoralkyl, hydrogen, and -WSA wherein W is a divalent linking group and A is defined
below.
[0019] W are divalent linking groups. Suitable divalent linking groups include, but are
not limited to, C₁ to C₁₀ alkylene, alkarylene, arylene, and alkoxyalkylene. Preferably,
W is selected from the group consisting of methylene and propylene.
[0020] G₂ and G₄ are the same or different and comprise A. A is a vinyl polymeric segment
consisting essentially of polymerized free radically polymerizable monomer. A can
comprise either a homopolymer segment or block or a copolymer segment or block. The
toner anchorage properties of the coating are determined by the vinyl polymeric segment
content. The chemical nature or composition of the vinyl polymeric segments can be
modified independent of the release aspect to improve toner anchorage and adhesion
to the substrate. Thus, the release coating can be chemically tailored to provide
a specific level of toner anchorage. The selection of the composition of A is typically
based upon the intended use of the release coating and the properties the release
coating must possess in order to accomplish its intended purpose.
[0021] A can include, but is not limited to, those monomers wherein the free radically polymerizable
monomer or monomers are chosen such that a vinyl segment has a T
g or T
m above about -20°C. The preferred free radically polymerizable monomers are selected
from the group consisting of styrene, methyl methacrylate, methyl acrylate, acrylic
acid, methacrylic acid, acrylonitrile, isobornyl acrylate, isobornyl methacrylate,
N-vinyl pyrrolidone, butyl methacrylate, isopropyl methacrylate, vinyl acetate, hydroxy
propylacrylate, hydroxy ethyl acrylate and mixtures thereof.
[0022] The amount and composition of the vinylic segment to silicone should range from about
98 to about 2 parts preferably, from about 40 to about 60 parts by weight. It is preferred
that the vinyl polymeric segments should have a molecular weight in the range of 2,000
to 80,000, more preferably 5,000 to 50,000.
[0023] The release properties of the coating are determined by both the silicone content
(weight percentage) present in the copolymer and the molecular weight of the silicone
segment, with higher silicone content and/or molecular weight providing easier release.
A copolymer or copolymer blend can, therefore, be chemically tailored to provide a
specific level of release which can be reproduced with consistency, thus making possible
the variation of the release properties of a liner over a range of values in a controlled
fashion.
[0024] The silicone polymeric segment must have an average molecular weight above about
1000 in order for the release coating to function properly. Preferably, the silicone
polymeric segment has a number average molecular weight of about 1000 to about 20,000.
Most preferably, the silicone polymeric segment has a number average molecular weight
ranging from about 2,000 to about 15,000. The silicone polymeric segment can comprise
about 2 to 60 wt% of the release coating in order to allow for a wide range of release
performance.
[0025] In another embodiment of the present invention, the release coating comprises a copolymer
of D and E monomers copolymerized to form a polymeric backbone. Grafted to the backbone
is an F monomer. The D and E monomers provide the toner anchorage properties of the
coating and the F monomer provides the release properties.
[0026] The D monomer or monomers (there may be more than one) are chosen such that the backbone
T
g or T
m is above about -20°C. Representative examples of D monomers include styrene, vinyl
acetate, vinyl chloride, vinylidene chloride, acrylonitrile and acrylic or methacrylic
acid esters of nontertiary alcohols or tertiary alcohols such as methanol, ethanol,
propanol, isopropanol, butanol, isobutanol, cyclohexanol, benzyl alcohol, dodecanol,
hexadecanol, and octadecanol, the alcohols having from 1 to 18 carbon atoms.
[0027] Especially preferred D monomers include methyl methacrylate, butyl methacrylate,
vinyl acetate, partially hydrolyzed vinyl acetate, methyl acrylate and octadecyl acrylate.
[0028] Representative E monomers useful in practicing the invention, and which may be used
either individually or in combination, include carboxylic acids such as acrylic acid,
methacrylic acid, itaconic acid, maleic acid, fumaric acid, and 2-carboxyethyl acrylate
and their ammonium or metal salts; sulfonic or phosphonic acids such as 2-sulfoethyl
methacrylate, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, styrene sulfonic
acid, and vinyl benzyl phosphonic acid and their ammonium or metal salts; amides such
as acrylamide, methacrylamide, N,N-dimethyl acrylamide, and N-vinyl pyrrolidone; and
monomers having hydroxyl functionality (e.g., 2-hydroxyethyl acrylate, 2-hydroxyethyl
methacrylate, hydroxypropyl acrylate, and dihydroxypropyl acrylate), ammonium functionality
derived from reaction of amine-containing monomers (e.g., N,N,-dimethylaminoethyl
methacrylate and vinyl pyridine) with alkylating agents or protic acids, or zwitterionic
functionality such as that derived by reaction of amine monomers with hydrogen peroxide
or propane sulfone.
[0029] The F monomer has the general formula:
X-(Y)
nSiR
(3-m)Z
m
[0030] X is a vinyl group copolymerizable with the D and E monomers.
[0031] Y is a divalent linking group.
[0032] R comprises hydrogen, lower alkyl groups such as methyl, ethyl, or propyl, aryl groups
such as phenyl or substituted phenyl and alkoxy groups such as methoxy and ethoxy
groups.
[0033] Z is a monovalent siloxane polymeric moiety having a number average molecular weight
above about 1,000 and is essentially unreactive under copolymerization conditions.
[0034] The preferred F monomer may be further defined as having an X group which has the
general formula

wherein R¹ is a hydrogen atom or a COOH group and R² is a hydrogen atom, a methyl
group, or a CH₂COOH group.
[0035] The Z group of the F monomer has the general formula

wherein R³ and R⁵ are independently lower alkyl, aryl, or fluoroalkyl, where lower
alkyl and fluoroalkyl both refer to alkyl groups having from one to three carbon atoms
and where aryl refers to phenyl or substituted phenyl. R⁴ may be alkyl, alkoxy, alkylamino,
aryl, hydroxyl, or fluoroalkyl, and r is an integer from about 5 to about 700. Preferably,
the F monomer has a general formula selected from the group consisting of the following,
where m is 1, 2 or 3, p is zero or 1, R" may be alkyl or hydrogen, and X, R, and Z
are as defined above:

wherein q is an integer from 2 to 6;

wherein q is an integer from zero to 2;

wherein q is an integer from 2 to 6;

and

wherein q is an integer from 2 to 6.
[0036] The release coating of the present invention may comprise the copolymers of the two
embodiments alone, or may comprise copolymers blended with other compatible homopolymers
and/or copolymers. The low percentage of silicone contained in the copolymers makes
the copolymers readily compatible with polymers of similar composition to the vinyl
Polymeric blocks or segments. In addition, there are several pairs of dissimilar polymers
that yield compatible blends due to specific interaction as described by S. Krause
in
Polymer Blends, Academic Press, New York, 1978. Introduction of a low level of silicone block onto
one of these polymers will not influence compatibility.
[0037] In addition, additives, fillers or pigments such as alumina, silica, titanate, or
calcium carbonate may, of course, be added to the copolymer compositions.
[0038] The release coating of the present invention should provide sufficient anchorage
to anchor at least 50% of the toner. It is understood that "substantially" means at
levels of at least 50%. More preferably, it should anchor at least 70% of the toner.
[0039] In addition, the release coating should have a surface release value not greater
than about 10 oz./in (11 N/dm). It should be understood that this upper limit applies
to use with highly aggressive pressure-sensitive adhesives (PSAs) which have peel
adhesion values of 45 N/dm or higher. PSAs as a group fall into three broad categories
(1) low (5-15 N/dm), (2) intermediate (25-50 N/dm), and (3) high (60-100 plus N/dm)
peel adhesion ranges. It is apparent that the degree of release can be selected to
match the aggressiveness of the PSA with which it will be in contact and it is only
for the most aggressive PSAs that a release value as high as 10 oz/in. (11 N/dm) would
be selected. Release coatings for less aggressive PSAs would be selected to be correspondingly
lower.
[0040] The release compositions do not require curing or crosslinking; however, if solvent
resistance is desired for a particular application, crosslinking can be effected by
standard methods well-known in the art, such as radiation curing (electron beam or
ultraviolet light) or chemical crosslinking.
[0041] The release coating compositions may be applied to any suitable backing or liner
by means of conventional coating techniques such as wire-wound rod, direct gravure,
offset gravure, reverse roll, air-knife and trailing blade coating. Suitable liners
include paper, non-woven fabrics and films of thermoplastic resins such as polyesters,
polyamides, polyolefins, polycarbonates and polyvinyl chloride.
[0042] In addition, any substrate which can be applied to a liner by a pressure sensitive
adhesive can be utilized. For example, paper is a suitable substrate.
[0043] In a preferred embodiment, the release coating of the present invention is utilized
as a component of label stock. In this preferred embodiment, one or more non-continuous
substrates such as labels are adhered to protective liner by a suitable adhesive.
To permit the substrate to be removed from the liner, the release coating of the present
invention is coated the liner.
[0044] The following examples are illustrative in nature and are not intended to limit the
invention in any way.
TEST SAMPLES
[0045] The polymer solutions of Examples 1 to 19 discussed below were diluted to 15% solids
in distilled water. The solutions were then coated onto commercially available roll
base paper with a gravure roll having a pyramidal pattern of 200 cells per inch. A
two roll direct gravure coating was applied to each sample. Two different roll base
papers were utilized. Supercalendered C1S paper supplied by the Simpson Paper Company
was coated with the diluted polymer solutions of Examples 1 to 4 and machine glazed
base paper sold by Akrosil were coated with the diluted polymer solutions of Examples
4 to 19. After coating, the base papers were dried at 77°C.
Test Methods
Release Properties
[0046] The release property of an adhesive refers to ease that an adhesive separates from
another surface. It is the force required to remove a flexible adhesive tape from
a test sample at a specific angle and rate of removal. It is measured in Newtons per
decimeter (N/dm) Two test methods are used to evaluate the release properties of coated
flexible sheet materials. Both tests are modified versions of the industry standard
peel adhesion test ASTM D3330-78 PSTC 1 and 3 used to evaluate PSA coated materials.
The two modified release property tests are described below.
1. Immediate Release Value
[0047] Each test sample was conditioned overnight at constant temperature (22°C) and humidity
(50% RH). Thereafter, a 5.08 cm by 25.4 cm strip of the test sample is laminated to
a constant 90° angle jig commercially available as the Deltron Ball Slide from the
J.R. Brass Co. of Eden Praire, MN with double coated tape. Then a 2.54 cm strip of
a PSA coated test tape was rolled down onto the laminate with a 1.82 kg rubber roller.
The force required to remove this tape at 90° and 30.5 cm/minute was then measured
was measured by a Sintech/Instron Tensile Tester System commercially available from
Sintech Corporation, a division of MTS Systems Corporation, Research Triangle Park,
North Carolina.
2. Aged Release Test
[0048] The aged release test was conducted in the same manner as the immediate release test
with the exception that the test tape was allowed to dwell in contact with the coated
paper for 3 days at 65°C and 50% RH, 11 days at 21°C and 80% RH, 11 days at 49°C dry,
and 11 days 49°C at 65% RH, prior to removal.
Toner Receptivity Testing
[0049] The toner receptivity of the test samples was assessed by printing on a 21.6 cm x
27.9 cm test sample an asterisk pattern, i.e., (****), in an Hewlett Packard LaserJet
II printer. The imaged coated sheets then sat overnight in a controlled environment
of 21°C and 50% RH. Thereafter, a 2.54 cm x 25.4 cm strip of Scotch™ Brand 810™ tape
manufactured by the Minnesota Mining and Manufacturing Company was rolled down over
the imaged test samples using two passes of a 1.82 kg rubber roller. After the two
passes, the test samples were allowed to sit in a controlled environment of 21°C and
50% RH for 24 hours. Then the Scotch™ Brand 810™ tape was laminated image side up
to the stage of in TIMI Release and Adhesion Tester sold by Testing Machines Inc.
of Mityville, New York with double coated tape. The 810™ tape was then removed at
a peel angle of 180°C at 3048 cm/minute. Image analysis was used to determine the
amount of toner which remained anchored to the coated sheet.
Abbreviations
[0050] AA - acrylic acid
AIBN - 2-2'-azobisbutyronitrile
BMA - butyl methacrylate
EMA - ethyl methacrylate
IPA - isopropyl alcohol
KF2001 - a mercaptofunctional dimethyl siloxane with 4-5 mole % mercapto functionality
commercially available from Shin-Etsu.
MA - methacrylic acid
MAA - methyl acrylate
MEK - methyl ethyl ketone
MMA - methyl methacrylate
ODA - octadecyl acrylate
Example 1
[0051] The composition of Example 1 was prepared in the following manner:
[0052] First, a solvent borne sample was prepared by charging a 32 oz. reaction bottle with
45 grams of mercaptofunctional dimethyl siloxane with 4-5 mole % mercapto functionality
commercially available as KF-2001 from Shin-Etsu, 169 grams of methyl acrylate, 11
grams acrylic acid, 335 grams of methyl ethyl ketone (MEK) and 0.56 grams 2-2'-azobisisobutyronitrile
(AIBN). The solution mixture was then purged with nitrogen for 2 minutes at a rate
of 1 L/min, after which the bottle was sealed. The sealed bottle containing the clear
solution was tumbled in a constant temperature bath for 20 hours at 55°C resulting
in a viscous cloudy white solution.
[0053] Thereafter, a waterborne solution was prepared by filling a gallon jar with 860 grams
deionized (DI) water and 9 grams NH₄OH. Next, 537 grams of the solvent borne solution
(40.0 % solids) was added to the solution in the gallon jar. The resulting solution
was placed on a shaker and shaken for one-half hour in order to complete the neutralization.
The MEK was then stripped from the resulting viscous solution on a rotary evaporator
at 40°C using an aspirator vacuum to yield 19.0 % solids aqueous solution. An additional
amount of DI water was added to obtain 15.0 % solids solution. The ingredients utilized
in forming a solvent borne solution and water borne solution and the amount of the
ingredients utilized are reported in Tables 1 and 2 respectively. The ingredients
of the release coating, the weight percentage of the ingredients and the test results
are reported in Table 3.
Examples 2-20
[0054] The copolymers of Examples 2-20 were prepared in accordance with the procedure outlined
in Example 1. The ingredients utilized in forming a solvent borne solution and water
borne solution and the amount of the ingredients utilized are reported in Tables 1
and 2 respectively. The ingredients of the release coating, the weight percentage
of the ingredients and the test results are reported in Table 3.
TABLE 1
Example |
Ingredients Utilized in Polymerization |
Amount of Ingredients Utilized (gms.) |
1 |
KF2001/MA/AA/MEK/AIBN |
45/169/11/335/0.56 |
2 |
KF2001/MA/AA/MEK/AIBN |
25/70/10/157.5/0.52 |
3 |
KF2001/MA/AA/MEK/AIBN |
50/140/20/315/0.53 |
4 |
KF2001/MA/MAA/MEK/AIBN |
50/140/10/300/0.5 |
5 |
KF2001/MA/MAA/MEK/AIBN |
52/182/26/390/0.65 |
6 |
KF2001/MA/MAA/MEK/AIBN |
62/173/25/390/0.65 |
7 |
KF2001/MA/MAA/MEK/AIBN |
60/140/20/330/0.55 |
8 |
KF2001/MA/MAA/MEK/AIBN |
60/140/10/315/0.53 |
9 |
KF2001/MA/MAA/MEK/AIBN |
50/120/10/300/0.5 |
10 |
KF2001/MA/MAA/MMA/MEK/AIBN |
65/130/13/52/390/0.65 |
11 |
KF2001/MA/MAA/MMA/MEK/AIBN |
30/75/7.5/37.5/225/0.38 |
12 |
KF2001/MA/MAA/MMA/MEK/AIBN |
37.5/60/7.5/45/225/0.38 |
13 |
KF2001/MA/MAA/MMA/MEK/AIBN |
37.5/45/7.5/60/225/0.38 |
14 |
KF2001/MA/MAA/MMA/MEK/AIBN |
37.5/30/7.5/75/225/0.38 |
15 |
KF2001/MA/MAA/MMA/MEK/AIBN |
39.5/71/7.9/31.6/225/0.38 |
16 |
KF2001/MA/MAA/MMA/MEK/AIBN |
35.7/78.6/7.1/28.6/225/0.38 |
17 |
KF2001/MA/MAA/MMA/MEK/AIBN |
34.1/81.8/6.8/27.3/225/0.38 |
18 |
KF2001/MA/MAA/MMA/MEK/AIBN |
32.6/84.8/6.5/26.1/225/0.38 |
19 |
KF2001/MA/MAA/MMA/MEK/AIBN |
31.2/87.5/6.2/25/225/0.38 |
20 |
KF2001/MA/MAA/MMA/MEK/AIBN |
50/100/10/40/300/1.0 |

[0056] The composition of Example 21 was prepared in the following manner:
[0057] First, a solvent borne sample was prepared by charging a 4 ounce glass bottle with
4 grams of 15K silicone macromer (SiMac), the preparation of which is described in
U.S. Patent No. 7,728,571, 16 grams ethyl methacrylate (EMA), 30 grams methyl ethyl
ketone (MEK) and 0.06 g 2-2'-azobisbutyronitrile (AIBN).
Thereafter, the contents of the bottle was purged with nitrogen gas for two minutes.
Then the bottle was sealed and tumbled in a 55°C water bath for 48 hours.
[0058] The sample was then diluted to 10% solids for coating. 40 grams of 40% solids polymer
solution, 96 grams of toluene and 24 grams of isopropanol (IPA) were added to a 16
ounce wide mouth jar. The mixture was then shaken to form a homogenous mixture. The
ingredients utilized in forming a solvent borne solution and the amount of the ingredients
utilized are reported in Tables 4 and 5 respectively. The ingredients of the release
coating, the weight percentage of the ingredients and the test results are reported
in Table 6.
Examples 22-27
[0059] The copolymers of Examples 22-27 were prepared in accordance with the procedure outlined
in Example 21. The ingredients utilized in forming a solvent borne solution and the
amount of the ingredients utilized are reported in Tables 4 and 5 respectively.
TABLE 4
Example |
Ingredients Utilized in Polymerization |
Amount of Ingredients Utilized (gms.) |
21 |
15K SIMAC/EMA/MEK/AIBN |
4/16/30/0.06 |
22 |
15K SIMAC/EMA/MMA/MEK/AIBN |
5/7.5/7.5/30/0.06 |
23 |
15K SIMAC/EMA/BMA/MEK/AIBN |
5/7.5/7.5/30/0.06 |
24 |
15K SIMAC/EMA/MA/MEK/AIBN |
5/7.5/7.5/30/0.06 |
25 |
15K SIMAC/MMA/BMA/MEK/AIBN |
5/7.5/7.5/30/0.06 |
26 |
15K SIMAC/EMA/ODA/MEK/AIBN |
5/11/4/30/0.06 |
27 |
15 K SIMAC/EMA/AA/MEK/AIBN |
5/7.5/7.5/30/0.06 |

COMPARATIVE EXAMPLES 1-5
[0060] The samples of Comparative Examples 1-5 comprised commercially available label stock
coated with toner receptive materials. The samples were tested in accordance with
the procedures outlined above utilizing acrylic tape. The label stock utilized and
the test results is reported in Table 7.

[0061] The test results indicate that the release coating of the present invention anchors
toner much more effectively than the release coatings utilized in the Comparative
Examples. Visually this is seen in a comparison of Figs. 1 and 2 wherein the samples
were tested in accordance with the Toner Receptivity Test described above. The asterisk
pattern in Fig. 2 was not substantially anchored compared to Applicants' release coating
shown in Fig. 1. Applicant's composition utilized in Fig. 1 comprises MA/MAA/MMA/KF2001
in the following amounts 50/5/20/25.
[0062] Thus, the coating of the present invention significantly decreases the attendant
problems associated with toner particles which are dislocated from release coatings.
[0063] In summary, a novel toner receptive release coating is described. Although specific
embodiments and examples of the present invention have been described herein, it should
be borne in mind that these are by way of explanation and illustration and the present
invention is not limited thereby. Certainly, modifications which are within the ordinary
skill in the art are considered to lie within the scope of this invention as defined
in the following claims including all equivalents.
1. A release coating receptive to particles emitted by electrophotoconductive devices
comprising a polymer having at least one vinyl polymeric segment having a Tg between -10°C and 65°C and at least one siloxane polymeric segment wherein release
coat is capable of substantially anchoring said particles thereto.
2. The release coating of Claim 1 wherein said polymer is a copolymer comprising the
formula:

wherein
R₁ are monovalent moieties which can independently be the same or different and
are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino,
hydroxyl, hydrogen, and fluoroalkyl;
R₂ can independently be the same or different and are divalent linking groups;
R₃ are monovalent moieties which can independently be the same or different and
are selected from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino,
hydroxyl, hydrogen, and fluoroalkyl;
R₄ can independently be the same or different and are divalent linking groups;
x is an integer of 0-3;
y is an integer of 10 or greater;
q is an integer of 0-3;; and
G₅ are monovalent moieties which can independently be the same or different selected
from the group consisting of alkyl, aryl, alkaryl, alkoxy, alkylamino, fluoralkyl,
hydrogen, and -WSA;
A is a vinyl polymeric segment or block consisting essentially of polymerized free
radically polymerized monomer;
G₆ are monovalent moieties which can independently be the same or different selected
from the group consisting of alkyl, aryl, alkoxy, alkylamino, fluoroalkyl, hydrogen
and -WSA; and
G₂ and G₄ are A.
3. The release coating of Claim 1 wherein said polymer is a copolymer of D and E monomers
copolymerized to form a polymeric backbone with F monomer grafted thereto wherein:
D is at least one free radically polymerizable vinyl monomer;
E is at least one polar monomer copolymerizable with D, the amount of E being up
to 30% of the total weight of all monomers, and
F is a monomer having the general formula
X-(Y)nSiR(3-m)Zm wherein
X is a vinyl group copolymerizable with the D and E monomers,
Y is a divalent linking group where n is zero or 1;
m is an integer of from 1 to 3;
R is hydrogen, lower alkyl (e.g., methyl, ethyl, or propyl), aryl (e.g., phenyl
or substituted phenyl), or alkoxy; and
Z is a monovalent siloxane polymeric moiety having a number average molecular weight
above about 1,000 and is essentially unreactive under copolymerization conditions.
4. The release coating of Claim 3 wherein said D monomer is selected from the group consisting
of styrene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, acrylic
or methacrylic acid esters of non-tertiary alcohols and tertiary alcohols having from
1 to about 18 carbon atoms and mixtures thereof.
5. The release coating of Claim 3 wherein said E monomer is selected from the group consisting
of acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylamide, N,N-dimethylacrylamide,
methacrylonitrile and maleic anhydride.
6. An image receiving article comprising:
a. a release coating coated over a portion of a front face of a liner comprising a
polymer having at least one vinyl polymeric segment having a Tg between -10°C and 65°C and at least one siloxane polymeric segment wherein said coating
is capable of substantially anchoring toner particles emitted by an electrophotoconductive
device; and
b. at least one substrate having a front and a back face, at least a portion of said
back face coated with an adhesive wherein said back face of said substrate is secured
to said liner.
7. The release coating of Claim 6 wherein said polymer is a copolymer comprising having
the formula:

wherein
R₁ are monovalent moieties which can independently be the same or different and
are selected from the group consisting of alkyl, aryl, alkylaryl, alkoxy, alkylamino,
hydroxyl, hydrogen, and fluoroalkyl;
R₂ can independently be the same or different and are divalent linking groups;
R₃ are monovalent moieties which can independently be the same or different and
are selected from the group consisting of alkyl, aryl, alkylaryl, alkoxy, alkylamino,
hydroxyl, hydrogen, and fluoroalkyl;
R₄ can independently be the same or different and are divalent linking groups;
x is an integer of 0-3;
y is an integer of 10 or greater;
q is an integer of 0-3;; and
G₅ are monovalent moieties which can independently be the same or different selected
from the group consisting of alkyl, aryl, alkylaryl, alkoxy, alkylamino, fluoralkyl,
hydrogen, and -WSA;
A is a vinyl polymeric segment or block consisting essentially of polymerized free
radically polymerized monomer;
G₆ are monovalent moieties which can independently be the same or different selected
from the group consisting of alkyl, aryl, alkoxy, alkylamino, fluoroalkyl, hydrogen
and -WSA; and
G₂ and G₄ are A.
8. The release coating of Claim 6 wherein said polymer is a copolymer of D and E monomers
copolymerized to form a polymeric backbone with F monomer grafted thereto
wherein
D is at least one free radically polymerizable vinyl monomer;
E is at least one polar monomer copolymerizable with D, the amount of E being up
to 30% of the total weight of all monomers, and
F is a monomer having the general formula
X-(Y)nSiR(3-m)Zm wherein
X is a vinyl group copolymerizable with the D and E monomers,
Y is a divalent linking group where n is zero or 1;
m is an integer of from 1 to 3;
R is hydrogen, lower alkyl (e.g., methyl, ethyl, or propyl), aryl (e.g., phenyl
or substituted phenyl), or alkoxy; and
Z is a monovalent siloxane polymeric moiety having a number average molecular weight
above about 1,000 and is essentially unreactive under copolymerization conditions.
9. The release coating of Claim 8 wherein said D monomer is selected from the group consisting
of styrene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, acrylic
or methacrylic acid esters of non-tertiary alcohols having from 1 to about 18 carbon
atoms and mixtures thereof.
10. The release coating of Claim 8 wherein said E monomer is selected from the group consisting
of acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylamide, N,N-dimethylacrylamide,
methacrylonitrile and maleic anhydride.
11. The article of Claim 6 wherein said substrate is a label.