|||||||||||||||||||||||||||||||||l|||||
`
`
`
`U800216344681
`
`(12) United States Patent
`Cole et a].
`
`(10) Patent No.:
`
`(45) Date of Patent:
`
`US 7,163,446 Bl
`Jan. 16, 2007
`
`(54) VEHICLE HEADLIGHT RESTORATION
`
`(761
`
`InVentors: John Ray (Sole. PO. Box 14493.
`Durham. NC (US) 27709; Ravonda
`Lynn Cole. I’D. Box 14493. l')urham.
`NC (115)22709
`
`200330211952 Al
`2004301219211 Al
`200450152758 Al
`200490235699 Al
`2006:“002442? Al “
`
`1132003 Held. 111 el al.
`632004 McDonald
`812004 Adickes
`1152004 Torres Moreno
`212006 Clyde el al.
`
`O'l‘I-IER PUBLICKI‘IONS
`
`427558
`
`[ ’1‘ ) Notice:
`
`Subject to any disclaimer. the term ot'thjs
`patent is extended or adjusted under 35
`use. 154(1)) by 0 days.
`
`(21) App1.No.: 111157.017
`
`(22)
`
`Filed:
`
`Jun. 20, 20:15
`
`(51)
`
`Int. (a.
`3243 7/30
`(52) U.S. (fl.
`
`(2006.01)
`451154: 451141: 4511’42:
`451157: 510t'163
`451154.
`[58) Field of Classification Search
`451141. 42. 57. 921: 5101163. 243
`See application file for complete search history.
`
`[56)
`
`References Cited
`
`11.8. PA'l'liNT DOCUMENTS
`
`3.659.307Ir A
`4.080.685 A
`4.661.182 A *
`5.248.521 A *
`5.443.604 A "‘
`5.569.346 A
`6.001.293 A
`6.244.707 Bl "'
`6.398.396 Bl
`6.428.407 151*
`6.583.092 Bl
`6.638.563 Bl
`6.831.049 Bl
`6.846.567 Bl
`6.855.210 Bl
`6.984.612 131*
`7.045.001 Bl‘“
`
`511922 Vilou
`351978 Vandcrpool
`411987 Lerner lS6.-"94
`9:”1993 Yamane el al.
`42111140
`
`8.11995 Stowell
`51330?
`[011906 Marshall
`12:”1999
`l‘igdore et a].
`632001 Faubl
`6-"2002 Nestell et at.
`812002 Elder
`612003 McDonald
`10-‘2003 McGee et at.
`[212004 Torres Moreno
`132005 Ekinaka el al.
`2-2005 Dostic ct a1.
`112006 Maillie
`532006 Kropp etal.
`
`3515160 H
`
`4513530
`
`510-163
`[06.53
`
`Clearstar
`Internet-
`
`collection of
`(‘oatings Corp.
`10 pages total. date unknown.
`
`screen shots
`
`from
`
`(Continued)
`
`
`
`Joseph .1. Hail. III
`Primary Examiner
`Assistant Examiner—Robert Scruggs
`[74) Attorney. Agent. or Firm—Miller Patent Services: Jerry
`A. Miller
`
`(57)
`
`ABSTRACT
`
`A method of restoring a discolored automobile headlight
`lens without
`removal of the lens from the automobile
`consistent with certain embodiments involves wet abrading
`an outer surface of the lens with successively finer grit wet
`sanding disks, using a low speed rotary or orbital tool having
`a flexible sanding holder holding the sanding disks. until a
`smooth surface is achieved exhibiting no discoloration.
`wherein the wet sanding disks comprise disks starting from
`approximately 220 to 400 grade down to approximately
`2000 grade: polishing the outer surface of the lens with an
`aqueous paste abrasive polish containing aluminum oxide
`abrasive particles; cleaning any residue from the outer
`surface of the lens by wiping the lens with a lint l‘rce cloth:
`and spraying a lilnl forming aqueous polymer dispersion
`containing an ultraviolet protectant to the outer surface of
`the lens. wherein the sealer comprises of acrylic urethane
`copolymers. l-lindcred Amine Light Stabilizers. benzotriaz-
`ole U \' light absorbers, l-methyl-2-pyrrolidone. and dipro-
`pylene glycol monolnetliyl ether. This abstract is not to be
`considered limiting. since other embodiments may deviate
`from the features described in this abstract.
`
`14 Claims. 2 Drawing Sheets
`
`SELECTCDARSE‘BRASNE GRADE
`BASED UPON HIRDNESS OF LENS AND
`
`DEGREE OF EIISCOLORM'IDN
`
`
`
`
`
`SELECT FINER
`
`GRADE UNTIL
`
`FINEST GRADE 15
`REJICHED
`
`
`WiPE ANDIDR
`
`RmsE A5
`NECESSARY
`
`
`
`
`40
`
`RNSE AND WIPE WlTH
`IJNT FREE CLOTH
`
`
`IIPPLY AQUEOUS
`SEALER AND UV
`
`
`
`
`
`
`001
`
`LKQ CORPORATION 1008
`LKQ CORPORATION 1008
`
`

`

`US 7,163,446 BI
`Page 2
`
`OTHER PUBLICATIONS
`
`Material Safety Data Sheet [or Brite Lites Lens Cleaner. two pages.
`date unknown.
`“Britt: Lites Plastic Lens Restoref'. Five pages from Internet, date
`unknown.
`Material Safety Data Sheet tbrAtha-Bufl'ZODD. two pages. May 19.
`[993.
`
`Material Safely Data Sheet for Clearslar High Performance Gloss
`Clear Protective Coating. two pages. Aug. 16. 200].
`“I-Iendlighl Restoration Kits“. Detail King‘s Supply Online Mall.
`Three pages from Internet. GoEmerchant. 2003.
`
`Crystal View Chemicals. Inc.. “Directions for Headlight Restoration
`Kit“. two pages from Internet. 2004.
`Lens Renew. “New Life for Your Plastic Headlight Lenses". two
`pages from Internet. 2004.
`Clearstar Coatings Corp. “Liquid Laminate Manual". 13 pages.
`2004.
`
`Rightlook Automotive Reconditioning Equipment & Training.
`Clearlights Headlight Restoration Kit.
`two pages from Internet.
`2005.
`
`" cited by examiner
`
`002
`002
`
`

`

`US. Patent
`
`Jan. 16, 2007
`
`Sheet 1 of2
`
`US 7,163,446 Bl
`
`START
`
`12
`
`SELECT COARSE ABRASIVE GRADE
`
`DEGREE OF DISCOLORATION
`
`BASED UPON HARDNESS OF LENS AND
`
`20
`
`WET ABRADE HEADLAMP SURFACE WITH
`
`LOW SPEED ABRASIVE DISK
`
`WIPE AN DIOR
`
`
`RINSE As
`SELECT FINER
`
`GRADE UNTIL
`NECESSARY
`
`
`
`FINEST GRADE IS
` REACHED
`
`
`40
`
`32
`
`YES
`
`RINSE AND WIPE WITH
`LINT FREE CLOTH
`
`POLISH WITH ALUMINUM
`OXIDE PASTE UNTIL
`VISUALLY CLEAR
`
`
`
`
`APPLY AQUEOUS
`
`SEALER AND UV
`
`PROTECTANT
`
`FIG. 1
`
`003
`003
`
`

`

`US. Patent
`
`Jan. 16, 2007
`
`Sheet 2 of2
`
`US 7,163,446 B1
`
`FIG. 2
`
`74
`
`90
`
`78
`
`82
`
`84
`
`
`
`004
`004
`
`

`

`US ?.163,446 El
`
`2
`
`1
`VEHICLE HEADLIGHT RESTORATION
`
`BACKGROUND
`
`As automobiles age and are exposed to sunlight. chariti-
`cals. pollution. soil. pollen. dust and other contaminants. the
`lenses of the headlights commonly take on a yellowish
`translucent or opaque appearance. This yellowish discolora-
`tion can be a surface film. an actual discoloration of the
`plastic commonly used to make such lenses or a combina-
`tion of both. This discoloration is not only unsightly and
`detracting from an automobile’s value. but also reduces the
`effective brightness and focus of the headlamps.
`One solution to this problem is replacement of the lens
`assembly. Unfortunately. replacement
`lens assemblies are
`costly. The labor involved to replace such lens assemblies
`can further escalate the price of replacement to surprisingly
`high levels. Whether one wishes to sell a vehicle with
`discolored headlights or retain it. it is obviously desirable to
`keep the cost of restoration of discolored lenses to a mini-
`mum.
`
`U.S. Pat. No. 6.831.041 describes a cleaning pad specifin
`cally made to clean headlight lenses. Various commercial
`products are also available on the market which are designed
`to restore headlight lenses. However. each has been found to
`have undesirable characteristics. For example, settle prod-
`ucts provide no protection against
`further damage and
`discoloration by the factors listed above. and others have in
`fact been used with unsatisfactory results by the current
`inventor. Other products contain harsh solvents and other
`chemicals which may either be dangerous to use or can
`potentially damage an automobile’s paint. Still others are
`complicated multiple part systems.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Certain illustrative embodiments illustrating organization
`and method of operation. together with objects and advan-
`tages may be best understood by reference to the detailed
`description that
`follows taken in conjunction with the
`accompanying drawings in which:
`FIG. 1 is a flow chart of a method of headlight lens
`restoration consistent with certain embodiments of the
`present invention.
`FIG. 2 illustrates an abrasive cleaning process consistent
`with certain embodiments of the present invention.
`FIG. 3 illustrates a sealant application process consistent
`with certain embodiments of the present invention.
`
`DETAILED DESCRIPTION
`
`in
`While this invention is susceptible of embodiment
`many diderent forms. there is shown in the drawings and
`will herein be described in detail specific embodiments. with
`the understanding that
`the present disclosure of such
`embodiments is to be considered as an example of the
`principles and not intended to limit the invention to the
`specific embodiments shown and described. In the descrip-
`tion below. like reference numerals are used to describe the
`same. similar or corresponding parts in the several views of
`the drawings.
`The terms “a“ or “an". as used herein, are defined as one
`or more than one. The term “plurality“. as used herein. is
`defined as two or more than two. The term “another"= as used
`herein. is defined as at least a second or tnore. The terms
`“including" andl'or “having". as used herein. are defined as
`comprising (i.e.. open language}. The temt “coupled". as
`
`used herein. is defined as connected. although not necessar-
`ily directly. and not necessarily mechanically.
`Reference throughout
`this document
`to “one embodi-
`ment“. “certain embodiments“. “an embodiment" or similar
`tenns means that a particular feature. structure. or charac-
`teristic described in connection with the embodiment
`is
`included in at least one embodiment ofthe present invention.
`Thus. the appearances of such phrases or in various places
`throughout this specification are not necessarily all referring
`to the saute embodiment. Furlhennore. the particular fea-
`tures. structures. or characteristics may be combined in any
`suitable manner in one or more embodiments without limi-
`lation.
`The terms “sandpaper" and “abrasive paper" and similar
`terms as used herein are intended to embrace coated or
`otherwise abrasive paper. cloth. fabric, mesh or other sub-
`strate materials without limitation. Moreover. other abrasive
`materials having similar properties can be readily substituted
`as equivalents without departing front
`the invention.
`' Accordingly. such terms should also be considered to
`embrace such equivalents.
`In view ofthe above background. it is desirable to provide
`a method for restoration of discolored (e.g., yellowed)
`automobile. or other vehicle. headlight assemblies which
`can be safely. and effectively used while the headlight lens
`assembly remains attached to the automobile or other
`vehicle. Such a method should preferably provide long
`lasting protection. while posing minimal danger to the user.
`Further. such a method should pose minimal danger to paint.
`chrome. rubber and other components of the automobile.
`Turning now to FIG. 1. a process 10 consistent with
`certain embodiments of the present invention is depicted in
`flow chart form starting at 12. An abrasive process is initially
`used to remove the film or yellowed portion of the lens
`surface starting at 16. At 16. a relatively coarse grit abrasive
`paper such as wett'dry sandpaper approximately in the range
`of grade 220 to 400.
`Sandpaper is graded using at least three difierertt systems:
`Coated Abrasives manufacturer’s institute [CAM1}. Federa-
`tion of European Producers Association (FEPA). and Japa-
`nese Industrial Standard (JlS). For purposes of this docu-
`ment. the example sandpaper grades are expressed using
`CAM] grading. but similar or corresponding grades (grits)
`from any other system can be utilized.
`At 16, the starting abrasive can be selected based upon a
`number of factors including hardness of the headlight lens
`(cg.
`lenses in certain FordTM automobiles have been
`observed to be noticeably harder than certain other lenses).
`the level of discoloration. and the aggressiveness of the tool
`being used. Generally. abrading can begin with a wett'dry
`sandpaper grade between about 220 and 400. and selection
`is based upon experience. One can generally safely start with
`400 grade and detennine if it appears to be cutting at an
`adequately aggressive pace. if not. the process can start over
`with a coarser grade such as 220 or 320.
`In certain embodiments. the abrading process of 20 is
`carried out using wet sanding with water and wett'dry
`sandpaper. The abrading can be carried out with a wettdry
`sanding disk (approximately 16 cm in diameter has been
`found suitable} mounted to a flexible backing (e.g.. a dense
`but flexible foam rubber backing) and driven by a low speed
`[actual speed has not been measured. but is roughly esti-
`mated to be in the range of several hundred to perhaps as
`much as 1000 RPM) rotary device such as an electric or
`pneumatic powered drill or other rotary tool. The speed of
`the rotary tool
`is selected to balance between speed of
`removal of the discoloration and the amotmt of heat that the
`
`10
`
`3o
`
`35
`
`4t:
`
`45
`
`50
`
`55
`
`6t;
`
`005
`005
`
`

`

`3
`
`4
`
`US ?.163,446 El
`
`lens cart tolerate witltout surface melting. Non-rotaryr tools
`such as orbital sanding devices (e.g.. quaner slteet devices]
`may be equivalently used and function well. provided they
`are not so aggressive as to melt the lens irt use. Use of
`random orbital sanding devices has been tried. and could
`possibly be effectively used. but the device tried was beett
`found to be difficult to control. Some headlight lenses also
`are more readily abraded by use of hand sanding. The
`selection of tool versus hand sanding is made depending
`upon the shape and contour of the headlight lens. Often.
`sortie level of hand abrading is rtecessary to reach hard to
`sand areas.
`Once the discoloration has been removed. or mostly
`removed by the coarse grade sanding,
`the lens cart be
`cleaned by wipirtg or rinsing if necessary at 24 to remove the
`larger grit particles that may remain and hinder removing the
`scratches. Successively liner grade sanding is then carried
`out by selection of finer grade sandpapers at 28 and repeat-
`ing the process. The objective of the succession of filter
`grade papers is to remove the large scratch marks from the
`surface of the lens until the lens appears to have a relatively
`smooth surface that is virtually free of visible individual
`scratches.
`'l‘his normally occtns at a sandpaper grade of
`approximately 2000, plus or minus a grade. A typical
`succession of grades might
`involve use of all common
`grades. or skipping every other available grade. or skipping
`two grades as the process proceeds. Commonly the fol low-
`ing progression of paper grades can be used:
`start:
`220—940046004800-42000. Other progressions with
`more or fewer grades may be in order depending upon the
`condition of the headlight. With experience. decisions as to
`which grade is appropriate to the current condition of the
`lens will be easily made. When the finest grade is reached at
`32 (norntally about 2000 grade). a final wet abrasion is
`carried out and the lens is wiped clean andt‘or rinsed at 24.
`At this point, the lens may still appear somewhat cloudy
`or foggy due to the microscopic scratches left behind from
`the line grit abrasive operation. bttt the yellow discoloration
`should be eliminated. At this point. the lens is polished at 36
`using a water based aluminum oxide paste polish which is
`diluted with water and applied either manually or with a
`polishing tool using a soft cloth or other ntaterial such as
`wool. In this operation. a water based polishing paste such
`as Aqua-Bull" 2000 (available from The Matchless Metal
`Polish Company, 840 West 49”" Place. Chicago, 111. 60609
`USA) has been found suitable. This material was developed
`for polishing the surface of boats and the like. This material
`comes as a dense paste (roughly the density of bread dough)
`arid contains very fine abrasive particles ofalttntinum oxide.
`For the operation of 36. the paste is diluted with water to
`achieve a consistency approximately that of toothpaste. This
`is normally achieved by dilution with approximately equal
`parts of water. bttt this dilution is not critical.
`Operation 36 continues until the lens appears visually
`clear to tltc naked eye. Additional water can be added to the
`lens surface during the polishing if the paste appears to be
`drying out. The paste residue is then washed off witlt water
`and dried with a lint free clotlt at 40. A lint free cloth is used
`to help assure that no particles of lint are attracted to the lens
`dttring the drying process. since such particles would appear
`oit the finished surface of the lens.
`
`At 44 a film forming aqueous polymer dispersion con-
`tainittg an ultraviolet protectant
`is applied to the outer
`surface of the lens. The preferred product for this use is a
`sealer and ultraviolet light (UV) protectant based upon art
`aqueous acrylic urethane with additives that inhibit andfor
`absorb UV light; however. aqueous polyurethane products
`
`3
`
`10
`
`'
`
`3o
`
`35
`
`4t]
`
`45
`
`50
`
`55
`
`6t;
`
`may possibly be substituted without departing front embodi—
`rttents consistent with the present invention.
`One product that has been found to be suitable for use as
`the sealer and UV protectant is commercially available from
`(.‘learstar Coatings Corporation (13.0. Box 390. isle of Palms.
`SC 29451 USA) and is
`commercially marketed as
`ClearShieldiE- Original fon'nulation gloss liquid laminate.
`When used in this application, the product is diluted by
`adding approximately 50% (e.g.. about 40% to 60%) of its
`volume of water and mixing well (i.e.. 100 ml. of sealer is
`added to 50 ml. of water to produce a total of 150 1111.). This
`product was developed as a liquid laminate product for use
`in sealing the surface of signs, banners. digital inkjet output.
`printed or airbrushed products. art. and other graphic arts
`products.
`it
`is noted that
`the abovenmentioned level of
`dilution is significantly greater than that recommended by
`the manufacturer. bttt has been found to work well.
`The portion of ClearShield-is Original formulation gloss
`liquid laminate which represents solids is not available from
`the manufacture. but an experiment was conducted to
`attempt to determine this attribute. A protective coating was
`applied to at 2.0'I by 2.0" (2.54 cnt by 2.54 cm) sample of
`LexanTM plastic in the same manner used for coating head-
`light
`lenses.
`'l‘he starting weight of the plastic was 7.77
`grams. Immediately afier application (while wet) the weight
`increased to 8.38 grams. indicating that approximately 0.6]
`grams of liquid was applied. After the sample was com-
`pletely dry. it was weighed again artd weighed 7.94 grams
`indicating that the dry weight of the coating was 0.17 grains
`which represents approximately 28% by weight of the
`diluted dispersion.
`ClearShieldER'J Original fomtulation gloss liquid lzuninate
`is a product which is based upon acrylic urethane copoly-
`mers. The product further contains Ilindered Amine Light
`Stabilizers and benzotriazole UV light absorbers. Addition—
`ally.
`l—methyl—Z—pyrrolidone is used to improve adhesion
`and dipropylene glycol monomethyl ether is used as a
`co-solvent to help the resin coalesce attd form a film. This
`product appears milky. but dries clear. This product has been
`found especially suitable because it
`is safe to use with
`minimal protective equipment. does not damage painted
`surfaces. rubber or other common automobile materials. and
`can be readily cleaned tip.
`While the invention should rtot be constrained by the
`theoretical explanation of operation of the various compo-
`rtents of tlte preferred protective coating. it is nonetheless
`believed to be useliil to speculate on the various properties
`of the components of the protective coating as follows.
`In ClearShieldt-ED Original formulation gloss liquid lami~
`hate. it is likely that the vast majority of tlte dried film is the
`acrylic urethane copolymer.
`It
`is likely that
`the acrylic
`urethane copolymer represents greater them 90% of the
`weight of the dried film. but
`this has not been verified
`experimentally. The acrylic urethane copolyrner matrix
`holds the UV protection in the film. The immediate appear-
`ance change caused by application of the acrylic urethane
`copolyrner is a loss of fogginess. The dried acrylic urethane
`copolyrtter ltas a refractive index rtear to that of the plastic
`that
`is being refinished (at
`least muclt closer than the
`refractive index of air is). If the bulk of the plastic of the
`headligltt lens is fairly clear. much ofthe foggincss is likely
`based on the surface of the headlight not being smooth on a
`microscopic
`scale. The many microscopic
`grooves.
`scratches and pits act as a collection of lenses. each aiming
`the light iii a difi'erent direction.
`Since light traveling between twu clear materials with the
`same refractive index is not dill'racted, a coating with a
`
`006
`006
`
`

`

`5
`
`US ?.163,446 El
`
`material of the saute refractive index is optically equivalent
`to the coating being identical to the underlying material. The
`clearing action of the film is likely. at least in large part. due
`to the film smoothing out the surface of the headlight. It is
`believed likely that any film with a similar refractive index
`would have a similar short term elllxt. Other polymer films
`(e.g.. polyurethane) would likely have a similar effect. but
`this analysis should not be considered limiting.
`Most UV damage to the plastics is caused by UV light
`causing highly reactive, short lived chemicals (radicals) to
`be formed. There are two widely used classes of additives to
`protect polymers from UV degradation. ClearShieldiEi Origi-
`nal formulation gloss liquid laminate has both.
`The easier type of protection to explain is that by UV
`absorbers. UV which is absorbed is not available to form the
`highly reactive. short lived chemicals which harm the poly-
`mer. The absorbance of the UV generally follows Beer’s
`law. Beer law states that the quantity of UV absorbed by the
`coating is proportional to the concentration in the coating
`times the thickness of the coating. This means that the UV
`absorbing protoctants protect the more interior plastic more
`than the tnore superficial plastic. Since the additive concen-
`tration is never infinity. the protection of the plastic by this
`sort of additive is essentially minimal at the surface of the
`polymer which the UV enters. Since this “sun screen" type
`of protection involves no special intermolecular chemistry.
`any compound that strongly absorbs the damaging UV
`wavelengths will do. ’l‘herefore.
`there is great chemical
`diversity among the UV absorbing additives which are
`commonly used. Within that there are various benzotriazole
`absorbers. The general structure is:
`
`110
`
`R.
`
`R'
`
`Hindered amine light stabilizers (HALS) act as radical
`scavengers. The HALS do not prevent the UV li'om causing
`the highly reactive. short
`lived chemicals to be formed.
`However, the HALS “defuse" the radicals so that they do not
`damage the plastic. The general structure for HALS is:
`
`
`
`ClearShieldt-‘R'I Original formulation gloss liquid laminate
`is also known to contain two solvents. l-methyl-Z-pyrroli-
`done (aka. NMP] (shown below) is used widely in paint
`strippers and strippers to remove resins. NMP helps less
`polar compoimds and water eohabitatc a solution or disper-
`sion. Dipropylenc glycol monomcthyl ether also helps less
`polar compounds and water cohabitate a solution or disper-
`s1on.
`
`ll]
`
`3U
`
`35
`
`4t:
`
`45
`
`50
`
`55
`
`on
`
`Many techniques might prove suitable for application of
`the sealer and protectant. The most suitable technique iden-
`tified to date has been use of a small (eg. 2 ounce bottle]
`pump fine mist atomizer bottle (widely available commer-
`cially at various retail outlets). The small size makes it easy
`to use and control for painting the surface of an automobile
`headlight at close proximity. Additionally. these bottles with
`attached atomizer are inexpensive and appear to work well
`without significant cloggi ng.
`The fine mist
`is simply painted on from top to bottom
`using short side to side strokes to form a continuous film of
`liquid over the lens surface. When dilute ClearShielth
`Original formulation liquid laminate is used. it is preferable
`that it be applied above 50" 1‘.
`in an environment that is
`shielded from or free of wind (to minimize overspray) and
`direct sunlight. At higher temperature and lower humidity, a
`retarder such as C learSltieldfi’C- RETARDER can be added to
`slow drying time. Somewhat low relative htunidity is also
`beneficial to facilitate drying. The film is permitted to dry
`and cure at 48 for roughly 15 minutes at which point it is
`usually dry to touch. Multiple coats. while not normally
`required. can be used if needed or desired. Drying time is
`somewhat variable‘ however. and additional curing can be
`expected to take place over a period of days. The process is
`completed at 50. at which point the headlight appears crystal
`clear. The surface is protected from further yellowing by the
`protective coating which is durable and long-lasting. The
`thickness of the protective coating varies according to
`application conditions.
`Thus. in accordance with certain embodiments. a method
`
`ol'restoring a discolored headlight lens without removal of
`the lens from the vehicle involves wet abrading an outer
`surface of the lens with successively finer grit abrasives until
`a smooth surface is achieved exhibiting no visible discol—
`oration; polishing the outer surface of the lens with an
`aqueous paste abrasive polish: cleaning any residue from the
`outer surface of the lens: and applying a sealer comprising
`a film forming aqueous polymer dispersion containing an
`ultraviolet protectant to the outer surface ot‘tlte lens, wherein
`the wet abrading, the polishing. the cleaning and the apply—
`ing are carried out while the headlight lens remains attached
`to the vehicle.
`
`Another method. consistent with certain embodiments, of
`restoring a discolored vehicle headlight
`lens without
`removal of the lens from the vehicle involves wet abrading
`an outer surface of the lens with successively fitter grit wet
`sanding disks. using a low speed rotary tool having a flexible
`sanding holder holding the sanding disks, until a smooth
`surface is achieved exhibiting no visible discoloration: pol—
`ishing the outer surface of the lens with an aqueous paste
`abrasive polish containing aluminum oxide abrasive par-
`ticles: cleaning any residue from the outer surface of the
`lens: and applying a sealer comprising a film forming
`aqueous polymer dispersion containing an ultraviolet pro-
`tectant to the outer surface of the lens, wherein the wet
`abrading. the polishing. the cleaning and the applying are
`carried out while the headlight lens remains attached to the
`vehicle.
`
`007
`007
`
`

`

`US ?.163,446 El
`
`7
`Yet another method. consistent with certain embodiments,
`of restoring a discolored automobile headligltt lens without
`removal of the lens frotn the automobile involves wet
`
`abrading an outer surface of the lens with successively finer
`grit wet sanding disks. using a low speed rotary or orbital
`tool having a flexible sanding holder holding the sanding
`disks. until a smooth surface is achieved exhibiting no
`discoloration. wherein the wet sanding disks comprise disks
`starting from approximately 220 to 400 grit down to
`approximately 2000 grit: polishing the outer surface of the
`lens with an aqtteotts paste abrasive polish containing alti-
`minum oxide abrasive particles: cleaning any residue from
`the outer surface of the lens by wiping the lens with a lint
`free cloth; and spraying a film forming aqueous polymer
`dispersion containing an ultraviolet protectant to the outer
`surface of the lens. wherein the dispersion comprising
`acrylic urethane copolymers. a l-lirtdered Amine Light Sta-
`bilizer. a benzotriazole UV light absorbers,
`l-methyl-2-
`pyrrolidone. and dipropylene glycol
`inonotnethyl ether.
`wherein the wet abrading. the polishing, the cleaning and the
`applying are carried ottt while the headlight lens remains
`attached to the vehicle.
`FIG. 2 illustrates the abrasive operation of 20 shown in
`disproportion for clarity. The headlight lens 70 is often held
`in place by a rubber gasket and frame assembly represented
`by 74 as well as possibly other supporting structures (not
`shown}. The outer surface containing the discoloration is
`represented by 78. A rotary tool such as a drill 82 drives the
`sanding disk 84. which is attached to a flexible disk 86 using,
`for example. hook and loop fasteners.
`During the abrasive operation. an accumulation of par-
`ticles 90 can agglonterate and can become trapped at the
`edge of the rubber gasket or other support structure. This
`residue of particles 90 should be cleaned by rinsing with
`water and perhaps wiping with a cloth before beginning the
`polishing operation.
`FIG. 3 illustrates the sealing process. A pump action
`sprayer 90 (similar in operation to that commonly used for
`window cleaner) which produces a fine mist is used to apply
`the sealer using a side to side motion to “paint“ the surface
`front top to bottom until the surface is completely covered
`with a film of the sealer solution. Overspray and drips can
`normally be wiped from surrounding surfaces with a cloth if
`done immediately after spraying. If such overspray or drips
`go unnoticed and are pemtitted to partially dry, they can still
`be removed by aggressive use of a clean cloth. in either
`event. however. since the sealer is in an aqueous solution
`free of strong solvents. it has been found to not damage the
`paint or other automobile surfaces. This permits the user to
`confidently and safely restore the headlight without the labor
`involved in removal of the headlight from the automobile.
`The process can commonly be completed in approximately
`thirty minutes per lens on average.
`A headlight lens refinished according to the present pro-
`cess produces a clearheadlight lens that is generally visually
`indistinguishable from a new headlight. Tests have indicated
`that the longevity of the coating is far superior to that of
`certain commercially available products which failed within
`weeks.
`
`The products needed to carry out the present operation
`can be supplied in kit lbnn containing a selection of wewa
`sandpaper ranging in grade from 220 to 5000. a supply of
`aqueous aluminum oxide paste. an application pad for the
`aluminum oxide paste. a lint free cloth and a supply of film
`forming aqueous polymer solution containing an ultraviolet
`prolectant. An application spray bottle liar the sealer can also
`be provided.
`
`ll]
`
`3U
`
`35
`
`4t:
`
`45
`
`50
`
`55
`
`60
`
`65
`
`8
`embodiments have been
`certain illustrative
`While
`described. it is evident that many alternatives. modifications.
`permutations arid variations will become apparent to those
`skilled in the art in light of the foregoing description.
`What is claimed is:
`l. A method of restoring a diseolored vehicle headlight
`lens without removal of the lens from the vehicle. compris—
`ing in combination the ordered steps of:
`(a) wet abrading an outer surface of the lens with suc-
`cessively finer grit abrasives until a smooth surface is
`achieved exhibiting no visible discoloration remaining;
`(b) polishing the outer surface of the lens with an aqueous
`paste abrasive polish;
`(c) cleaning any residue from the outer surface of the lens;
`and
`(d) applying a sealer comprising a film forming aqueous
`polymer dispersion containing an ultraviolet protectant
`to the outer surface of the lens. wherein the wet
`abrading. the polishing. the cleaning and the applying
`are carried out while the headlight
`lens
`remains
`attached to the vehicle. wherein the sealer comprises an
`aqueous dispersion containing acrylic urethane copoly-
`mers, a hindered amine U V protectant, a benzotriamle
`UV protectant.
`l-methyl-Z-pyrrolidone and dipropy-
`lene glycol monomethyl ether.
`2. The method according to claim I. wherein the wet
`abrading is carried out using a rotary or orbital drive tool to
`drive a sanding pad.
`3. The method according to claim 1, wherein the applying
`comprises spraying the sealer onto the outer surface of the
`lens.
`
`4. The method according to claim 1. wherein the cleaning
`is carried out by wiping the lens with a lint li'ee cloth.
`5. The method according to claim I. wherein the aqueous
`paste abrasive polish comprises an aluminum oxide paste
`polish.
`6. A vehicle headlight that has been restored according to
`the method of claim 1.
`
`7. The method according to claim 1. wherein the film
`forming aqueous polymer dispersion consists essentially of
`(TlearShieldiRJ Original brand formulation of gloss liquid
`laminate containing acrylic urethane eopolymers, a Hin—
`dered Amine Light Stabilizer. a benzotriazole UV light
`absorber.
`l-methyl-anyrrolidone. and dipropylene glycol
`monomethyl ether dilttted with a volume of water represent-
`ing approximately 50% of the volume ofthe liquid laminate.
`8. A method of restoring a discolored vehicle headlight
`lens without removal of the lens from the vehicle. compris-
`ing in combination the ordered steps of:
`(a) wet abrading an ottter surface of the lens with suc-
`cessively finer grit wet sanding disks. using a low speed
`rotary tool having a flexible sanding holder holding the
`sanding disks, ttntil a smooth surface is achieved exhib-
`iting no visible discoloration remaining:
`(b) polishing the outer surface ofthe lens with an aqueous
`paste abrasive polish containing aluminum oxide abra—
`sive particles;
`(c) cleaning any residue from the outer surface of the lens.
`and
`
`(d) applying a sealer comprising a film forming aqueous
`polymer dispersion containing an ultraviolet protectant
`to the outer surface of the lens. wherein the wet
`abrading, the polishing, the cleaning and the applying
`are carried out while the headlight
`lens
`remains
`attached to the vehicle. wherein the sealer comprises an
`aqueous dispersion containing acrylic urethane copoly-
`mers, a hin