U.S. patent application number 13/588420 was filed with the patent office on 2013-02-21 for screen protector film.
The applicant listed for this patent is Dennis P. O'Donnell. Invention is credited to Dennis P. O'Donnell.
Application Number | 20130045371 13/588420 |
Document ID | / |
Family ID | 47712860 |
Filed Date | 2013-02-21 |
United States Patent
Application |
20130045371 |
Kind Code |
A1 |
O'Donnell; Dennis P. |
February 21, 2013 |
SCREEN PROTECTOR FILM
Abstract
A multi-layer screen protector for digital display screens, such
as LCD's, cell phones, tablets, laptops, and pad computer devices,
that may be readily applied without the need for special tools and
in dusty environments, the screen protector being designed and
die-cut to match the shape of the digital display screen, including
cut-outs for cameras, microphones and device buttons, where the top
surface is a layer of polycaprolactone aliphatic urethane that is
connected to a bottom layer made from plastic such as polystyrene,
acrylic and/or polyethylene terephthalate, and a self-wetting
adhesive layer provided on the bottom surface of the bottom
polystyrene, acrylic and/or polyethylene terephthalate layer. The
screen protector provides an optically clear view of the device and
is constructed with the abrasion resistant layer being provided and
supported on a plastic layer and may be removed and
reinstalled.
Inventors: |
O'Donnell; Dennis P.;
(Philadelphia, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
O'Donnell; Dennis P. |
Philadelphia |
PA |
US |
|
|
Family ID: |
47712860 |
Appl. No.: |
13/588420 |
Filed: |
August 17, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61524931 |
Aug 18, 2011 |
|
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|
Current U.S.
Class: |
428/215 ;
428/220; 428/339; 428/354 |
Current CPC
Class: |
Y10T 428/2891 20150115;
Y10T 428/266 20150115; Y10T 428/31551 20150401; B32B 7/12 20130101;
Y10T 428/31565 20150401; C09J 7/29 20180101; Y10T 428/2495
20150115; B32B 7/02 20130101; C09J 7/25 20180101; B32B 27/40
20130101; C09J 2475/00 20130101; Y10T 428/1471 20150115; Y10T
428/2861 20150115; B32B 27/08 20130101; C09J 2203/318 20130101;
C09J 2301/162 20200801; Y10T 428/28 20150115; Y10T 428/2848
20150115; C09J 2433/00 20130101; Y10T 428/269 20150115; C09J
2425/006 20130101; B32B 2457/00 20130101; C09J 2433/006 20130101;
Y10T 428/24967 20150115; B32B 27/308 20130101; C09J 2467/006
20130101 |
Class at
Publication: |
428/215 ;
428/354; 428/339; 428/220 |
International
Class: |
C09J 7/02 20060101
C09J007/02; B32B 27/40 20060101 B32B027/40; B32B 7/02 20060101
B32B007/02; B32B 27/08 20060101 B32B027/08 |
Claims
1. A protective film for an electronic display, the protective film
comprising: a first layer having a top and a bottom, said top
comprising a top surface that forms the top surface of said
protective film; said first layer being made from urethane, a
second layer having a top and a bottom, said bottom comprising a
bottom surface that forms the bottom surface of said protective
film; said second layer being made from an optically clear
supporting plastic material, wherein said first layer and said
second layer comprise a laminated film wherein said first layer and
said second layer are laminated so that said bottom of said first
layer and said top of said second layer are engaged, and wherein
said first layer top comprises the top surface of said laminated
film, and wherein said second layer bottom forms the bottom surface
of said laminated film; and a self-wetting adhesive provided on
said bottom surface of said film.
2. The protective film of claim 1, wherein said protective film is
cut to a shape that matches the display surface which it is meant
to protect.
3. The protective film of claim 1, wherein said protective film is
planar and is contoured to correspond with the surface profile of
an electronic device or a screen of an electronic device.
4. The protective film of claim 1, wherein said urethane consists
essentially of polycaprolactone aliphatic polyurethane.
5. The protective film of claim 1, wherein said plastic material is
selected from the group consisting of acrylic, polystyrene and
polyethylene terephthalate.
6. The protective film of claim 1 wherein said protective film has
a peel adhesion of less than 1.0 oz/in.
7. The protective film of claim 1 wherein said screen protector has
a peel adhesion of about 0.2 oz/in.
8. The protective film of claim 1, wherein said self-wetting
adhesive consists of a low tack adhesive, and wherein said adhesive
provided on said bottom surface of said film provides for removal
and reinstallation of said protective film on said electronic
display.
9. The protective film of claim 1, wherein said self-wetting
adhesive comprises an adhesive that is capable of removably
securing the protective film to a screen display surface with
minimal or no external pressure.
10. The protective film of claim 1, wherein said self-wetting
adhesive comprises (a) a pre-polymerized cross-linkable non-water
soluble acrylic based pressure sensitive adhesive, (b) a
cross-linking agent selected from the group consisting of metal
chelates, silanes, epoxy-functional compounds, aziridine compounds,
multifunctional amines, alkyl halide compounds, multifunctional
acids, multifunctional mercaptans, multifunctional epoxy compounds,
polyols in the presence of a catalyst, and combinations thereof and
(e) a polyol having a weight average molecular weight in the range
from 1,000 g/mol to 10,000 g/mol.
11. The protective film of claim 7, wherein said self-wetting
adhesive comprises (a) a pre-polymerized cross-linkable non-water
soluble acrylic based pressure sensitive adhesive, (b) a
cross-linking agent selected from the group consisting of metal
chelates, silanes, epoxy-functional compounds, aziridine compounds,
multifunctional amines, alkyl halide compounds, multifunctional
acids, multifunctional mercaptans, multifunctional epoxy compounds,
polyols in the presence of a catalyst, and combinations thereof and
(c) a polyol having a weight average molecular weight in the range
from 1,000 g/mol to 10,000 g/mol.
12. The protective film of claim 1, said first layer comprises a
polycaprolactone aliphatic polyurethane and wherein said second
layer comprises a material selected from the group consisting of
acrylic and polystyrene plastics and polyethylene terephthalate,
and wherein said first layer bottom surface is attached to said
second layer top surface and said self-wetting adhesive is provided
on said second layer bottom surface.
13. The protective film of claim 1, wherein said first layer of
polycaprolactone aliphatic polyurethane comprises an optically
clear layer.
14. The protective film of claim 13, wherein said optically clear
first layer together with said second layer and said adhesive layer
comprise a three-layer screen protector that is optically clear and
has a top surface that is resistant to abrasion.
15. The protective film of claim 12, wherein said polycaprolactone
aliphatic polyurethane first layer comprises a layer having uniform
thickness and having a top surface which is substantially smooth
and a bottom surface which is substantially smooth, and wherein
said second layer has a uniform thickness.
16. The protective film of claim 15, wherein said screen protector
has a zone of coverage comprising the screen protector area that
covers the viewing area of said electronic display, and wherein
said zone of coverage comprises said first layer having a uniform
thickness and said second layer having a uniform thickness and
having a substantially smooth bottom surface, said adhesive being
provided on said substantially smooth bottom surface.
17. The protective film of claim 14, wherein the first layer has a
thickness of from about 1 mil to 8 mils.
18. The protective film of claim 17, wherein the second layer has a
thickness of from about 0.5 mil to 8 mils.
19. The protective film of claim 19, wherein the thickness of the
screen protector is from about 1.5 mils to about 16 mils plus the
thickness of said self-wetting adhesive provided on said bottom
surface of said film,
20. A protective film for an electronic display, the protective
film comprising: a first layer having a top and a bottom, said top
comprising a top surface that forms the top surface of said
protective film; said first layer being made from urethane, wherein
said urethane consists essentially of polycaprolactone aliphatic
polyurethane; a second layer having a top and a bottom, said bottom
comprising a bottom surface that forms the bottom surface of said
protective film, said second layer being made from an optically
clear supporting plastic material, wherein said plastic material is
selected from the group consisting of acrylic, polystyrene and
polyethylene terephthalate; wherein said first layer and said
second layer comprise a laminated film wherein said first layer and
said second layer are laminated so that said bottom of said first
layer and said top of said second layer secured together; wherein
said first layer top comprises the top surface of said laminated
film; wherein said second layer bottom forms the bottom surface of
said laminated film; and a self-wetting adhesive provided on said
bottom surface of said film; wherein said protective film is cut to
a shape that matches the display surface which it is meant to
protect; wherein said protective film is planar and is contoured to
correspond with the surface profile of an electronic device or a
screen of an electronic device; wherein said protective film has a
peel adhesion of about 0.2 oz/in; wherein said self-wetting
adhesive consists of a low tack adhesive, and wherein said adhesive
provided on said bottom surface of said film provides for removal
and reinstallation of said protective film on said electronic
display; wherein said self-wetting adhesive comprises an adhesive
that is capable of removably securing the protective film to a
screen display surface with minimal or no external pressure;
wherein said self-wetting adhesive comprises (a) a pre-polymerized
cross-linkable non-water soluble acrylic based pressure sensitive
adhesive, (b) a cross-linking agent selected from the group
consisting of metal chelates, silanes, epoxy-functional compounds,
aziridine compounds, multifunctional amines, alkyl halide
compounds, multifunctional acids, multifunctional mereaptans,
multifunctional epoxy compounds, polyols in the presence of a
catalyst, and combinations thereof and (c) a polyol having a weight
average molecular weight in the range from 1,000 g/mol to 10,000
g/mol; wherein said first layer bottom surface is attached to said
second layer top surface and said self-wetting adhesive is provided
on said second layer bottom surface; wherein said first layer of
polycaprolactone aliphatic polyurethane comprises an optically
clear layer; wherein said polycaprolactone aliphatic polyurethane
first layer comprises a layer having uniform thickness and having a
top surface which is substantially smooth and a bottom surface
which is substantially smooth, and wherein said second layer has a
uniform thickness; wherein said protective film has a zone of
coverage comprising the screen protector area that covers the
viewing area of said electronic display, and wherein said zone of
coverage comprises said first layer having a uniform thickness and
said second layer having a uniform thickness and having a
substantially smooth bottom surface, said adhesive being provided
on said substantially smooth bottom surface; wherein the first
layer has a thickness of from about 1 mil to 8 mils; and wherein
the second layer has a thickness of from about 0.5 mil to 8 mils.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application Ser. No. 61/524,931, filed on Aug. 18, 2011, the
complete contents of which are herein incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of screen
protectors for touch screen displays, and more particularly to a
removable, repositionable protective film for a touch screen
display.
[0004] 2. Brief Description of the Related Art
[0005] Touch screens are widely used, including in portable
electronic devices, such as, cellular telephones and portable
computing devices, including readers and tablets, such as the
popular iPad.RTM.. A factor owing to the popularity of these
electronic touch screen devices is their portability. The devices
are generally lightweight, or compact. As a result, users often
carry and use these electronic devices when traveling or when
participating in daily activities. In many cases, the touch screens
of these electronic devices come in contact with other objects and
items, and may be prone to being scratched. In the case of cellular
telephones, a user may place the phone in the user's pocket or
purse along with potentially other sharp items, such as, for
example, keys, nail files, key chains, coins, pens and other
objects. There is a need to protect the screens of these electronic
devices, and prior art devices have used a film that is placed on
the screen surface, the film being attached to the surface
statically or with the use of an adhesive.
[0006] There are drawbacks with the prior screen protectors. Screen
protectors require that the screen surface be cleaned and that it
be free from any dust or debris. The presence of dust or other
particles on the screen surface will come between the screen
protector and the touch screen surface and impair or compromise the
viewing quality. If dust particles are present, often the screen
protector is raised by the dust particle to be off of the surface
of the touch screen. This results in an occurrence of what may be
referred to as "tenting" around the dust particle, creating a
bubble. The bubbles created impair the viewability of the screen,
as the bubbles may be noticeable and interfere with a user's
ability to view the screen in those locations where the bubbles are
present. In addition, the presence of bubbles may hamper the
ability of the screen protector to remain secured to the screen
surface.
[0007] U.S. Patent Application 2012/0043015, published on Feb. 23,
2012, discloses a method and apparatus for protecting an electronic
device. The '015 disclosure specifies an adhesive and a mechanical
smoothing device (i.e., a squeegee) for applying the film onto a
screen. In addition, the '015 method and apparatus require the
elimination of debris and fingerprints prior to applying or
reapplying the film. Aside from being time consuming to use and
apply because the display surface must be cleaned before the film
is installed, in environments where dust is present, such as, on a
battlefield, in a war zone, factory, or other locations where
cleaning items are not readily available or practical to use, the
'015 device and method are not suitable. Another aspect of the '015
apparatus is that the film is disclosed to be elastic and highly
conformable so that the film may be applied to complex
geometries.
[0008] U.S. Patent Application 2007/0077420, published on Apr. 5,
2007, discloses a polyether aliphatic urethane film for protection
of exposed surfaces of automobiles, trailers and boats that may
come into contact with environmental hazards (such as dirt, dust,
rocks, sand road salt, bird droppings). The '420 application
discloses a base layer that may be a polyether aliphatic urethane,
and a base layer that may be made of laminated or combined layers.
The '420 application discloses a topcoat that may be applied to the
base layer and which may comprise a resin. The application of the
'420 protective film is designed for automobiles, including the
leading edges of automobile hoods.
[0009] U.S. Patent application 2011/0267793 published on Nov. 3,
2011 discloses a protective adhesive film polyurethane sheet with a
pressure-sensitive adhesive that includes an acrylate polymer and a
silicone macromer disposed on a portion of the first surface of the
polyurethane sheet. The '793 application also discloses using a
smoothing device to apply the film to a surface. The presence of
dust or debris generally will interfere with the smoothing device,
and, in many instances, when dust is present on the screen surface,
the film is required to be removed, the screen cleaned, and the
film reapplied. In many cases, the film may be compromised and
cannot be reapplied due to surface dirt becoming embedded on the
film surface. Consequently, a new sheet of film is needed when the
film becomes compromised. Even fingerprints may cause problems in
applying films to a display surface.
[0010] U.S. Pat. No. 7,070,837, issued on Jul. 4, 2006, discloses a
screen protector for preventing interference patterns (e.g., Newton
rings) from arising when the film touches the screen. The '837
patent discloses a hard plastic film, such as PET, is used as the
protective film, and a non-uniform urethane resin is disposed on a
lower surface in contact with the screen. The '837 device provides
a roughened surface on the film so that the majority of the film
surface facing the screen does not substantially touch the screen.
The '837 disclosure also specifies that no adhesive or adhesive
forces are used to hold the film to the screen.
[0011] U.S. Patent Application 2011/0043727 published on Feb. 24,
2011, discloses an adhesive layer for multilayer optical article.
The adhesive layer is disposed between optical article's multilayer
optical film and the light transmissive support layer of a display,
such as an LCD television. The '727 discloses the use of glass as a
potential component of the multilayer optical article and is part
of an article that is assembled as a display device. In addition,
the '727 application discloses a method of making display devices
including the optical article.
[0012] U.S. Patent Application 2011/0129643, published on Jun. 2,
2011, discloses a surface protective sheet for a metal plate, a
resin plate or glass plate that includes a high tack adhesive or
high anchoring force, and that provides a preferred haze value of
20% to 80%. The '643 disclosure identifies two outer layers of
polyethylene which sandwich a middle mechanical property control
layer that may consist of urethane.
[0013] One attempt to address the presence of dust particles has
been disclosed in U.S. Pat. No. 8,044,942, issued on Oct. 25, 2011,
for a touch screen protector which provides a spacer along an outer
perimeter of a plastic film surrounding a transparent window and
having a thickness sufficient to space the plastic film near but
not in contact with the touch screen.
[0014] There are drawbacks with the prior devices, and none of the
prior devices has been found to be completely suitable. A need
exists for an improved touch screen protector that can be readily
and easily applied to and removed from a touch screen surface in
conditions of uncontrolled environments without compromising the
optical quality.
SUMMARY OF THE INVENTION
[0015] A screen protector film is provided for fast, bubble-free,
field installation of the screen protector film onto the surface of
a touch screen display, such as a display of a laptop, tablet, cell
phone or other touchscreen portable devices. The screen protector
film may be used on the surfaces of electronic touch screen
displays in order to protect the displays from dirt, debris and
other potentially abrasive objects that may come into contact with
the display.
[0016] It is an object of the present invention to provide a
multilayer screen protector that is suitable for high wear and
uncontrolled environments, such as, those settings commonly found
where medical, military and industrial operations are carried out.
In these types of environments, high resistance to abrasion along
with fast and easy installation are required without compromising
the optical quality as a result of impediments, such as, dirt or
dust, that may be present in the environment, as may be likely in
the case of a factory or in a war zone.
[0017] It is an object of the invention to provide a screen
protector that may be readily and easily installed on a screen
display, and which may be removed, replaced, or reinstalled.
[0018] It is another object of the present invention to provide a
screen protector that provides protection against abrasion and
surface abuse, and which provides optical clarity for viewing the
display screen that the screen protector is guarding.
[0019] Another object of the invention is to provide a screen
protector that can pass MIL-STD-810F Method 510.4, which involves a
blowing sand test. The test is part of the "Department of Defense
Test Method Standard for Environmental Engineering Considerations
and Laboratory Tests" and is a standards test for environmental
conditions that seeks to replicate the effects of environments on
the equipment. The MIL-STD-810 test series are approved for use by
departments and agencies of the United States Department of Defense
(DoD).
[0020] It is another object of the invention to accomplish the
above objects by providing a screen protector that may be easily
and readily installed, removed and re-installed by the user in the
user's operating environment.
[0021] It is another object of the invention to accomplish the
above objects where the screen protector may be installed on a
display screen without additional installation aids or
chemicals.
[0022] It is another object of the invention to accomplish the
above objects where the screen protector may be installed on a
screen display that has dust or fingerprints on the display, and
still provide an optically suitable, clear and/or bubble-free
surface.
[0023] It is another object of the present invention to accomplish
the above objects where a protective layer is provided as a uniform
top layer with a top surface that provides resistance to abrasion
and may be layered as a laminate with a supportive layer, where the
uniformity of the top layer provides optical clarity and uniformity
over the screen protector, and, in particular, the screen protector
portion that covers a display screen.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0024] FIG. 1 is a right side elevation view of a screen protector
film according to my invention.
[0025] FIG. 2 is a schematic illustration of an exemplary process
arrangement for attaching the layers of the multilayer screen
protector.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Referring to FIG. 1, a multilayer screen protector 10 is
shown having a top layer 20, a bottom layer 30 and an adhesive
layer 40. The top layer has a top surface 21 and a bottom surface
22. The bottom layer 30 has a top surface 31 and a bottom surface
32. The adhesive layer 40 is provided on the bottom surface 32 of
the bottom layer 30. The adhesive layer 40 is comprised of an
adhesive that is a low tack adhesive that provides suitable
adhesion of the screen protector to a display surface, but which
also allows the screen display, once installed on the surface of a
display, to be removed and re-installed. According to preferred
embodiments, the screen protector 10 is constructed as a planar
structure.
[0027] According to the preferred embodiment, the adhesive that
forms the adhesive layer 40 is a self-wetting adhesive. According
to a preferred embodiment, the peel adhesion of the adhesive layer
is less than about 10 oz/in, and preferably less than 5 oz/in. In
the more preferred embodiments, the peel adhesion of the screen
protector 10 with the adhesive is about 1 oz/in or less. According
to one preferred embodiment, peel adhesion of the adhesive is
substantially less than 1.0 oz/in, and, according to a most
preferred embodiment, the peel adhesion is 0.2 oz/in. The peel
adhesion force of the self-wetting adhesive is obtained through
ASTM D-3330, which utilizes a 180 degree peel adhesion Test Method
A for single coated tapes, wherein an adhesive backed item is
adhered to a glass plate (or steel plate) and is then removed by
moving the plate at a specified rate, while recording the average
force required for peeling the item from the plate. For example,
the ASTM D-3330 test may be carried out by adhering the specimen to
a testing plate, folding an end of the specimen to create a tab
parallel to the plate, securing the end of the plate furthest away
from the tab to the moving grip, securing the tab to the static
grip, peeling the tape at a 180 degree angle by moving the plate at
the specified rate, and recording the average force required for
peeling. The peel adhesion for the adhesive is for a laminate 10
consisting of a top layer 20 made of urethane, and preferably,
polycaprolactone aliphatic urethane (PAU), a bottom layer 30 made
of a plastic, and preferably, polyethylene terephthalate, with the
adhesive provided on the bottom surface 32 of the bottom layer 30.
An example of a suitable adhesive that may be used and applied to
achieve the desired peel adhesion forces and provide the
self-wetting properties is an acrylic based self-wetting adhesive.
According to one preferred embodiment, a preferred self-wetting
adhesive that may be utilized comprises (a) a pre-polymerized
cross-linkable non-water soluble acrylic based pressure sensitive
adhesive, (b) a cross-linking agent selected from the group
consisting of metal chelates, silanes, epoxy-functional compounds,
aziridine compounds, multifunctional amines, alkyl halide
compounds, multifunctional acids, multifunctional mercaptans,
multifunctional epoxy compounds, polyols in the presence of a
catalyst, and combinations thereof and (e) a polyol having a weight
average molecular weight in the range from 1,000 g/mol to 10,000
g/mol.
[0028] The screen protector 10 preferably may be applied to a
screen display surface in the presence of dirt or dust on the
screen display. Dust and dirt are components common to a number of
working environments, in particular, such as, for example, on the
military fields of operations, in factories, outdoor environments,
sporting events (e.g., fields and tracks). Often, there are not the
resources, time or facilities by which to remove the dust, dirt,
fingerprints and other interfering items that may be present on the
screen display prior to installation of a screen protector. The
screen protector 10 includes a layer 40 that consists of a low tack
adhesive that is self-wetting and preferably wets out over the
display surface to promote the attachment of the protector 10 onto
a display screen.
[0029] The screen protector 10 has a top layer 20 that is a
protective layer that resists abrasion and provides increased
resistance to harsh environments and high-wear conditions. The
military battlefield is one example of a high-wear environment
where abrasive conditions are often encountered by the screen
protector 10 and device on which it may be installed. According to
a preferred embodiment, the screen protector 10 has a top layer 20
that is made from urethane, and more preferably from
polycaprolactone aliphatic urethane (PAU), which is a highly
abrasive-resistant material. According to a preferred embodiment,
the PAU top layer has a thickness of from 1 mil to 8 mil (0.0254 mm
to 0.2032 mm). The polycaprolactone aliphatic urethane layer 20
preferably is thin and is supported by the bottom layer 30.
[0030] The screen protector bottom layer 30 represents the
structural layer that supports the polycaprolactone aliphatic
urethane layer 20. The illustration in FIG. 1 shows the
polycaprolactone aliphatic urethane layer 20 supported directly on
the bottom layer 30. The bottom layer 30 is a hard plastic
structural layer which is constructed from a rigid plastic
material, and which, preferably, may be constructed from a plastic
material, such as, for example, a hard clear plastic, preferably
from plastic materials selected from the group consisting of
acrylic and polystyrene. According to one preferred embodiment,
another material from which the bottom layer 30 may be made is
polyethylene terephthalate. According to a preferred embodiment,
the bottom layer 30 has a thickness of from about 0.5 mils to 8
mils (0.0127 mm to 0.2032 mm). The polycaprolactone aliphatic
urethane layer 20 preferably is thin and is supported by the bottom
layer 30.
[0031] The bottom layer 30 and top layer 20 are connected together.
According to a preferred embodiment, the top layer 20 and bottom
layer 30 are co-extruded so that the layers 20, 30 form a
multi-layer laminate layer. According to a preferred embodiment,
the multi-layer laminate formed from the two layers now includes
the top surface 21 that is an abrasive resistant polycaprolactone
aliphatic urethane surface on the top polycaprolactone aliphatic
urethane layer 20, and the bottom surface 32 that is the plastic
surface of the plastic bottom layer 30. The hard plastic bottom
layer 30 provides suitable rigidity for the screen protector 10.
The polycaprolactone aliphatic urethane surface 21 and the
polycaprolactone aliphatic urethane top layer 20 are supported by
the rigid plastic bottom layer 30. The laminate formed consisting
of the polycaprolactone aliphatic urethane top layer 20 and plastic
bottom layer 30 has the abrasion resistant top surface 21 and the
supportive bottom layer 30. The top layer 20 preferably is a thin
layer of polycaprolactone aliphatic urethane and provides abrasion
resistance and optical clarity as a uniform layer in conjunction
with the supporting structure, which is the plastic bottom layer
30, that preferably also is a uniform layer, so that the screen
protector 10 is a film having excellent optical clarity qualities
as well as superior abrasion resistance.
[0032] The securing together of the top layer 20 and bottom layer
30 is accomplished to maintain the optical clarity of the laminate.
According to a preferred embodiment, a laminate of coextruded
polycaprolactone aliphatic urethane and rigid plastic is formed
having optically clear properties, to which the adhesive layer 40
is applied to form the screen protector 10. According to a
preferred embodiment, the top layer 20 and bottom layer 30 are
secured together without an additional component between the
layers. According to an alternate embodiment, a bonding agent or
adhesive may be used to accomplish the lamination of the top layer
20 and the bottom layer 30. A high tack aggressive adhesive, such
as, for example, acrylic adhesives, may be used in order to bond
the top layer 20 to the bottom layer 30. In this example, the
aggressive adhesive secures the bottom surface 22 of the top layer
20 to the top surface 31 of the bottom layer 30. According to one
embodiment, the top layer, such as, for example, the layer of
polycaprolactone aliphatic urethane, may be provided with an
aggressive, high tack adhesive thereon, on the bottom surface 22. A
wet or dry lamination process may then be used to adhere the
polycaprolactone urethane layer 20 to the bottom layer 30.
According to one embodiment, the lamination of the top layer 20 and
bottom layer 30 may be carried out using a wet lamination procedure
where the aid of a water/surfactant blend is used to minimize
imperfections that may be present in the lamination. Other suitable
methods may be employed to laminate the top layer 20 and bottom
layer 30.
[0033] The screen protector 10 according to a preferred embodiment
consists of a coextruded polycaprolactone aliphatic urethane top
layer 20 and a plastic bottom layer 30 secured together to form a
film, the film having structural rigidity and having a durable,
clear and abrasion-resistant surface 21. According to a preferred
embodiment, the plastic layer may be a hard layer, but generally is
a poor abrasion protection agent. The plastic layer provides
structural support for the polycaprolactone aliphatic urethane
layer. Preferably, the formed laminate screen protector 10 is a
planar structure suitable for installation on a flat surface. The
construction of the layers and the film 10 provides an optically
clear and uniform abrasion resistant surface. The present screen
protector 10 is abrasion resistant and may be readily installed on
a display screen in almost any environment and without the need for
tools.
[0034] The adhesive layer 40 is applied on the bottom surface 32 of
the bottom layer 30 to form the screen protector 10. Preferably,
the adhesive is a self-wetting adhesive. The adhesive may be
applied by any suitable method for applying adhesives to a surface,
including, for example, rolling or spraying the adhesive onto the
bottom surface 32. Other examples of adhesive application include
gravure coating, air knife, hot melt, curtain, reverse roll or any
other method suitable to this application. Although not shown, a
release material or backing, such as release paper, may be
removably installed on the adhesive layer 40 to provide protection
of the layer 40 prior to the time that the screen protector 10 is
actually installed on a display screen. The release paper may
comprise a suitable composition that is compatible with the
adhesive, and which will not degrade or break down when coming into
contact with the adhesive layer 40 that the backing is provided to
protect. The adhesive, according to the preferred embodiments, is a
low tack adhesive with limited gripping power to permit the screen
protector 10 to be easily and quickly removed from a screen display
surface and re-installed in the field if necessary, while still
providing sufficient gripping to prevent accidental removal from
the display screen on which the screen protector 10 is attached.
According to a preferred embodiment, the screen protector 10 is
attached to a display with an adhesive which provides a relatively
low bond of less than 10 oz per inch of peel adhesion, and more
preferably, less than 5 oz per inch of peel adhesion, and according
to a most preferred embodiment, the adhesive has a peel adhesion of
about 0.2 oz per inch. The adhesive also provides the ability to
remove and replace the screen protector 10 on a display without the
need to remove the adhesive from the surface of the screen display.
The adhesive is not applied to the polycaprolactone aliphatic
urethane top layer 20, but rather is applied to the hard plastic
structural layer, the bottom layer 30, which, according to
preferred embodiments, may be a polystyrene or acrylic layer or a
PET layer. According to one embodiment, the adhesive 40 is applied
to the bottom layer surface 32 of the structural or bottom layer 30
and the structural layer 30 is then connected to the top layer 20
through a co-extrusion process. According to another embodiment,
the structural layer 30 is connected to the top layer 20 through a
co-extrusion process, and the adhesive layer 40 is applied to the
bottom layer surface 32.
[0035] The screen protector 10 may be applied to virtually any
display surface to prevent abrasion. The screen protector 10
provides improved resistance to scratching and allows for improved
ease of installation. The construction of the screen protector 10
also provides remedial solutions for improper installation or
errors, in that the adhesive composition and placement in
conjunction with the bottom layer 30 remains active for
re-installation or repositioning of the screen protector 10 on a
screen display.
[0036] The lamination of the top layer 20 and bottom layer 30 may
be carried out using any process suitable to the application. An
exemplary lamination embodiment is illustrated in FIG. 2, where,
according to the exemplary embodiment illustrated, a laminate 10'
is shown consisting of a layer of polycaprolactone aliphatic
urethane (PAU) 20' and a layer of plastic 30'. The laminate 10' is
shown extruded from the rollers 60 apply pressure to secure the
polycaprolactone aliphatic urethane (PAU) layer 20' and plastic
layer 30' together. The rollers 60 may be driven by any
conventional driving means, such as, for example chain drives, belt
drives, shaft drives or other direct or indirect drives and may be
moved with a motor. The rollers 60 are shown having rotational
directions indicated by arrows "a" and "b" to drive the
polycaprolactone aliphatic urethane (PAU) layer 20' and plastic
layer 30' together through the rollers in compressive engagement
(and with the adhesive layer 40 also when it is present on the
bottom surface 32' of the bottom layer 20'. The lamination may be
accomplished in the presence of heat. According to one embodiment,
an adhesive layer 40', which is a self-wetting, low tack adhesive,
may be applied to the surface 32' of the laminate 10' after the
extrusion of the polycaprolactone aliphatic urethane (PAU) layer
20' and plastic layer 30', or, alternately, may be provided on the
bottom surface 32' of the plastic layer 30', before the lamination
together of the polycaprolactone aliphatic urethane (PAU) layer 20'
and plastic layer 30'. A cutter, not shown, may be placed in line
downstream of the rollers 60 to cut the laminate 10' into suitable
lengths or pieces (or screen protector configurations, including
cut outs). The screen protector 10' may be cut and configured to
the dimensions of a screen display, and used as the screen
protector 10 shown and described herein.
EXAMPLE 1
[0037] A screen protector of the present invention was constructed
from a polycaprolactone aliphatic urethane layer and a PET layer. A
self-wetting adhesive consisting of an acrylic pressure sensitive
adhesive was applied to the bottom surface of a 0.002'' PET layer.
A release liner was applied over the adhesive layer on the bottom
surface of the PET layer. A 0.006'' polycaprolactone aliphatic
urethane layer was laminated to the PET layer. A roll of the
multi-layer film was formed. A screen protector was cut from the
roll stock using die cutters, drag knife, tangential knife, or
laser cutters to provide a screen protector having mating
dimensions to cover a touch screen of a cellular telephone. Mating
cutouts for a home button, a speaker, microphone, and front camera
were made in the screen protector.
[0038] The screen protector was subjected to an ASTM D3330 peel
adhesion test, and the peel adhesion was determined to be 0.2
oz/inch. The screen protector exhibited good self-wetting
properties as well as resistance to external factors such as dust,
fingerprints, and dirt, while maintaining optical quality. The
screen protector was also subjected to MIL-STD-810F Method 510.4, a
blowing sand test, and exhibited excellent resistance to abrasion.
Optical clarity was maintained.
[0039] According to preferred embodiments, the first layer of
polycaprolactone aliphatic polyurethane is an optically clear
layer. The supporting layer preferably works in conjunction with
the optical capabilities of the first polycaprolactone aliphatic
polyurethane layer to maintain the optical clarity of the layer and
screen protector and to provide a structural bed for the abrasion
resistant layer.
[0040] According to preferred embodiments, the screen protectors
are constructed by bringing together the optically clear top layer
20 of polycaprolactone aliphatic polyurethane with the bottom layer
30 consisting of an acrylic or polystyrene layer, and with the
self-wetting adhesive layer on the bottom surface 32 of the bottom
layer 30 to provide a three-layer screen protector 10 with a
non-reflective top surface 21 and having non-reflective surface
properties when installed on a screen of an electronic device. The
construction of the screen protector 10 is designed to maintain and
produce the properties desirable for non-reflectiveness as well as
abrasion resistance and ease of field installation.
[0041] According to a preferred embodiment, the screen protector 10
is designed and die-cut to match the shape of the digital display
screen and includes cut-outs for cameras, microphones, buttons and
the like.
[0042] The multi-layer screen protector 10 may be applied to
digital display screens, such as LCD's, displays of cell phones,
tablets, laptops and pad computer devices, including touch screens.
The screen protector 10 may be readily applied to a display surface
without the need for special tools, and may be installed in dusty
environments. The screen protector 10 is designed and die-cut to
match the shape of the digital display screen, including having
cut-outs for cameras, microphones, speakers, and device
buttons.
[0043] These and other advantages may be obtained through the use
of the inventive apparatus and methods disclosed herein. While the
invention has been described with reference to specific
embodiments, the description is illustrative and is not to be
construed as limiting the scope of the invention. Various
modifications and changes may occur to those skilled in the art
without departing from the spirit and scope of the invention
described herein and as defined by the appended claims.
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