U.S. patent application number 14/246285 was filed with the patent office on 2014-10-16 for fabric having ultraviolet radiation protection.
The applicant listed for this patent is Robert B Kramer, Ronald Kramer, Nicholas Marshall, Jason Rosenberg. Invention is credited to Robert B Kramer, Ronald Kramer, Nicholas Marshall, Jason Rosenberg.
Application Number | 20140304922 14/246285 |
Document ID | / |
Family ID | 51685744 |
Filed Date | 2014-10-16 |
United States Patent
Application |
20140304922 |
Kind Code |
A1 |
Kramer; Robert B ; et
al. |
October 16, 2014 |
FABRIC HAVING ULTRAVIOLET RADIATION PROTECTION
Abstract
A method for treating mercerized cotton for incorporating
ultraviolet radiation protection into the mercerized cotton is
disclosed which comprises the steps of placing the mercerized
cotton into a solution of Zn(II), removing the mercerized cotton
from the solution, and washing the mercerized cotton. Other methods
for treating cotton for protection from ultraviolet radiation are
also disclosed.
Inventors: |
Kramer; Robert B; (St.
Louis, MO) ; Kramer; Ronald; (St. Louis, MO) ;
Marshall; Nicholas; (Charleston, SC) ; Rosenberg;
Jason; (Shorewood, WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kramer; Robert B
Kramer; Ronald
Marshall; Nicholas
Rosenberg; Jason |
St. Louis
St. Louis
Charleston
Shorewood |
MO
MO
SC
WI |
US
US
US
US |
|
|
Family ID: |
51685744 |
Appl. No.: |
14/246285 |
Filed: |
April 7, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13643223 |
Oct 24, 2012 |
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14246285 |
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13317152 |
Oct 11, 2011 |
8277518 |
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13643223 |
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Current U.S.
Class: |
8/116.1 |
Current CPC
Class: |
D06M 11/38 20130101;
D06M 13/188 20130101; D06M 11/44 20130101; D06M 11/56 20130101 |
Class at
Publication: |
8/116.1 |
International
Class: |
D06M 13/503 20060101
D06M013/503 |
Claims
1. A method for treating mercerized cotton for incorporating
ultraviolet radiation protection into the mercerized cotton
comprising the steps of: placing the mercerized cotton into a
solution of Zn(II); removing the mercerized cotton from the
solution; and washing the mercerized cotton.
2. The method of claim 1 further comprising the step of drying the
mercerized cotton.
3. The method of claim 1 wherein the solution of Zn(II) comprises
zinc acetate dissolved in water.
4. The method of claim 3 wherein the solution of Zn(II) further
comprises 4.39 g. of zinc acetate (20 mmol) dissolved in 100 mL of
deionized water.
5. The method of claim 3 wherein the solution of Zn(II) further
comprises 4.39 g. of zinc acetate (20 mmol) dissolved in 100 ml of
distilled water.
6. The method of claim 1 wherein the solution of Zn(II) comprises
zinc acetate dissolved in water and amine added added to the zinc
acetate dissolved in water.
7. The method of claim 6 wherein the amine comprises ethanolamine,
ethylenediamine, or (tris)hydroxymethylaminomethane.
8. The method of claim 1 wherein the solution of Zn(II) comprises
zinc sulfate heptahydrate, sodium chloride, and sodium
hydroxide.
9. The method of claim 8 wherein the zinc sulfate heptahydrate
comprises 5.75 g. zinc sulfate heptahydrate (20 mmol), the sodium
chloride comprises 0.88 g (15 mmol) sodium chloride, and the sodium
hydroxide comprises 1.6 g. (40 mmol) sodium hydroxide.
10. A method for treating cotton for incorporating ultraviolet
radiation protection into the cotton comprising the steps of:
placing the cotton into a concentrated mercerization strength NaOH
solution; placing the cotton into a solution of Zn(II); removing
the cotton from the solution of Zn(II); and washing the cotton.
11. The method of claim 10 further comprising the step of drying
the cotton.
12. The method of claim 10 wherein the solution of Zn(II) comprises
zinc acetate dissolved in water.
13. The method of claim 12 wherein the solution of Zn(II) further
comprises 4.39 g. of zinc acetate (20 mmol) dissolved in 100 mL of
deionized water.
14. The method of claim 12 wherein the solution of Zn(II) further
comprises 4.39 g. of zinc acetate (20 mmol) dissolved in 100 ml of
distilled water.
15. The method of claim 10 wherein the solution of Zn(II) comprises
zinc sulfate heptahydrate, sodium chloride, and sodium
hydroxide.
16. The method of claim 15 wherein the zinc sulfate heptahydrate
comprises 5.75 g. zinc sulfate heptahydrate (20 mmol), the sodium
chloride comprises 0.88 g (15 mmol) sodium chloride, and the sodium
hydroxide comprises 1.6 g. (40 mmol) sodium hydroxide.
17. A method for treating cotton for incorporating ultraviolet
radiation protection into the cotton comprising the steps of:
placing the cotton into a concentrated mercerization strength NaOH
solution; placing the cotton into a solution of Zn(II); placing the
cotton into a solution of NaOH; removing the cotton from the
solution of NaOH; and washing the cotton.
18. The method of claim 17 further comprising the step of drying
the cotton.
19. The method of claim 17 wherein the solution of Zn(II) comprises
zinc acetate dissolved in water.
20. The method of claim 17 wherein the solution of Zn(II) comprises
zinc sulfate heptahydrate, sodium chloride, and sodium hydroxide.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 13/632,223 filed on Oct. 1, 2012, which is now
U.S. Pat. No. 8,690,964, which was a continuation-in-part of U.S.
patent application Ser. No. 13/317,152 filed on Oct. 11, 2011,
which is now U.S. Pat. No. 8,277,518.
BACKGROUND
[0002] This disclosure relates to a fabric having ultraviolet
radiation protection, and more specifically, to a fabric having
ultraviolet (UV) radiation protection incorporated into the fabric
by use of a laundry additive or photographing.
[0003] Ecological friendly fabrics or Eco-friendly fabrics are
gaining in popularity and use in clothing. An Eco-friendly fabric
may be a natural fiber such as cotton, hemp, or bamboo which has
been grown in soil that has not been treated with pesticides for a
number of years. Some examples of other Eco-friendly fabrics are
organic cotton, sisal, a combination of hemp and recycled rayon, a
combination of hemp and cotton, broadcloth, denim, linen, and a
combination of bamboo and recycled rayon. Natural fibers, which may
be derived from plants or animals, such as wool, angora, silk,
alpaca, cashmere, and silk are also examples of Eco-friendly
fabrics. Synthetic fabrics, which may be made from synthetic
sustainable products, such as nylon, rayon, olefin, spandex, and
tencel are also examples of Eco-friendly fabrics.
[0004] To assist an individual in determining whether a garment has
protection against ultraviolet radiation, a rating system has been
developed. This rating system is known in the industry as the UPF
(Ultraviolet Protection Factor) rating system. Clothing having a
rating of UPF 50 are able to block out 98% of the sun's ultraviolet
radiation. Further, by way of example, a garment having a rating of
UPF 15-24 will only block out 93.3% to 95.9% of ultraviolet
radiation. Exposure to the sun's harmful ultraviolet radiation
(known as UVA/UVB rays) can damage the skin, can cause sunburn, and
can lead to skin cancer over prolonged exposure.
[0005] There are a number of factors that affect the level of
ultraviolet radiation protection provided by a fabric and the UPF
rating. Some factors are the weave of the fabric, the color of the
fabric, the weight of the fabric, the fiber composition of the
fabric, the stretch of the fabric, moisture content of the fabric.
If the fabric has a tight weave or a high thread count then the
fabric will have a higher UPF rating. However, even though the
fabric has a higher UPF rating, the fabric may be less comfortable
because a tighter weave or higher thread count means that the
fabric is heavy or uncomfortable to wear. Another factor that
affects protection is the addition of chemicals such as UV
absorbers or UV diffusers during the manufacturing process. As can
be appreciated, some of the features that make a garment
comfortable to wear also make the garment less protective. A
challenge for a clothing manufacturer is to provide clothing having
both protection from the sun and being comfortable to wear.
[0006] Therefore, it would be desirable to provide a fabric that
can be treated to protect an individual from the effects of the
sun. Moreover, there is a need for a controllable process for
attaching UV protection to a fabric after the fabric has been
manufactured so that the treated fabric may be used to protect an
individual from UV radiation. Furthermore, it would be advantageous
to incorporate adequate protection in a garment, fabric, or textile
to protect against exposure to UV radiation, to increase the UV
resistance of a garment, fabric, or textile, or to enhance UV
radiation absorption of a garment, fabric, or textile to protect an
individual from UV radiation.
BRIEF SUMMARY
[0007] In one form of the present disclosure, a method for treating
mercerized cotton for incorporating ultraviolet radiation
protection into the mercerized cotton is disclosed which comprises
the steps of placing the mercerized cotton into a solution of
Zn(II), removing the mercerized cotton from the solution, and
washing the mercerized cotton.
[0008] In another form of the present disclosure, a method for
treating cotton for incorporating ultraviolet radiation protection
into the cotton comprises the steps of placing the cotton into a
concentrated mercerization strength NaOH solution, placing the
cotton into a solution of Zn(II), removing the cotton from the
solution of Zn(II), and washing the cotton.
[0009] In yet another form of the present disclosure, a method for
treating cotton for incorporating ultraviolet radiation protection
into the cotton comprises the steps of placing the cotton into a
concentrated mercerization strength NaOH solution, placing the
cotton into a solution of Zn(II), placing the cotton into a
solution of NaOH, removing the cotton from the solution of NaOH,
and washing the cotton.
[0010] The present disclosure provides a fabric having ultraviolet
radiation protection which is lightweight and can be worn in any
temperature.
[0011] The present disclosure provides a fabric having ultraviolet
radiation protection which provides enhanced protection from both
UVA and UVB radiation when worn by an individual.
[0012] The present disclosure also provides a fabric having
ultraviolet radiation protection which retains ultraviolet
radiation protection after use or after cleaning.
[0013] The present disclosure provides a fabric having ultraviolet
radiation protection which is comfortable to wear.
[0014] The present disclosure provides a fabric having
antimicrobial protection incorporated therein.
[0015] The present disclosure also provides a fabric having
ultraviolet radiation protection which can be manufactured without
increasing the cost of the fabric.
[0016] The present disclosure provides a fabric having ultraviolet
radiation protection that may be incorporated into the fabric by
use of a laundry additive.
[0017] The present disclosure provides a fabric having ultraviolet
radiation protection that is incorporated into active wear clothing
or athletic clothing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] Various methods or processes are disclosed herein for the
immobilization of UV-blocking nanoparticles on Eco-friendly fabric
to incorporate UV protection in the fabric. Once the UV-blocking
nanoparticles are attached, the Eco-friendly fabric will be able to
protect a wearer of the fabric from UV radiation. One method
comprises direct immobilization from in situ formation of the
particles. A second method comprises carboxylation or
phosphorylation of the fabric followed by binding of the
UV-blocking nanoparticles to the modified fabric. A third method
comprises modifying UV-blocking nanoparticles with a self-assembled
monolayer (SAM) or polymer layer containing an active chemical
group capable of binding to the fabric and deposited on the fabric
from solution.
[0019] ZnO (zinc oxide) nanoparticles are generally formed by the
precipitation of a zinc salt (acetate, sulfate, nitrate, chloride)
using either aqueous hydroxide or an amine. The following examples
disclose direct immobilization from in situ formation of the ZnO
nanoparticles.
EXAMPLE 1
Solution Sol-Gel Process, Hydroxide Base
[0020] 4.39 g. zinc acetate (20 mmol) is dissolved in 100 mL
deionized or distilled water. A textile is added to this solution
and 100 mL 0.4M NaOH is added while mixing. The suspension is mixed
for 2 hours to form a suspension of zinc oxide nanoparticles in
contact with the fabric. The textile is removed from the
nanoparticle suspension and laundered in a household washing
machine. As can be appreciated, a fabric may be treated to have
ultraviolet radiation protection incorporated in the fabric by the
steps of dissolving zinc acetate or other zinc salt in a liquid to
form a solution containing Zn(II) ions, adding a fabric to the
solution, mixing the solution and the fabric, and adding a base to
the solution when the solution and the fabric are being mixed to
form a suspension of zinc oxide nanoparticles in contact with the
fabric.
EXAMPLE 2
Solution Sol-Gel Process, Amine Base
[0021] 4.39 g. zinc acetate (20 mmol) is dissolved in 100 mL
deionized water. A textile is added to this solution while mixing
and 40 mmol amine is added while mixing. Amines used may include
ethanolamine, ethylenediamine, (tris)hydroxymethylaminomethane, or
others. The textile is removed from the nanoparticle suspension and
laundered in a household washing machine.
EXAMPLE 3
Mechanochemical Process
[0022] 5.75 g. zinc sulfate heptahydrate (20 mmol) and 0.88 g (15
mmol) sodium chloride are powered finely and blended, then placed
with a textile in a ball mill or similar mechanical mixer. 1.6 g
(40 mmol) sodium hydroxide is powdered and added to the mixer.
After twenty minutes, the textile is removed and rinsed thoroughly
with water.
[0023] The following examples disclose carboxylation or
phosphorylation of the fabric followed by binding of the
UV-blocking nanoparticles to the modified fabric.
EXAMPLE 4
Modification of Textile with Phosphonic Acid Groups
[0024] For this process it will be necessary to modify a textile
with phosphonic acid groups. This can be accomplished in a number
of ways, but it is desirable to use materials that are non-toxic
and/or renewably sourced chemicals. Phosphorylated cellulose should
form covalent linkages with ZnO and TiO.sub.2 nanoparticles. The
interaction between phosphonates and oxide surfaces are used for
modification of the oxide surfaces. In essence, the procedure
consists of condensing the cellulose textile with a bis(phosphonic
acid), phosphonate, or phosphate species, either organic or
inorganic. Urea may be added to forestall discoloration of the
textile. Phosphorylation takes place driven by the elimination of
water. The resulting phosphorylated textile will directly bind both
zinc oxide and titanium oxide nanoparticles. It will be necessary
to restrict the degree of phosphorylation of the textile to prevent
great alteration in the properties of the textile by controlling a
reaction time. This process does not require in situ synthesis of
the zinc oxide nanoparticles. Commercially available zinc oxide
nanoparticles may be used.
[0025] A sample of cotton textile is wetted with a 10% v/v solution
of phosphoric acid or bis-phosphonic acid containing 10-30% w/v
urea. The textile is pressed to remove excess solution and baked in
an oven at 85-100.degree. C. for 5 minutes to dry, then at
170.degree. C. for 2-4 minutes to cure unreacted groups. The
textile is removed from the oven and washed with water. The textile
is then used without further modification in subsequent deposition
steps.
EXAMPLE 5
Modification of a Textile by Partial TEMPO-H.sub.2O.sub.2
Oxidation
[0026] A sample of cotton textile (ca. 1 g) is added to a solution
composed of 90 mL water with 10 mg (0.065 mmol) TEMPO and 0.22 g (2
mmol) sodium bromide. Hydrogen peroxide 3% is added (0.9 mL, 1
mmol) and the reaction stirred at RT for 10 minutes to 2 hours. The
material is washed with water, dried, and used without further
modification in the following ZnO deposition step.
EXAMPLE 6 Immobilization of Nanoparticles on a Phosphorylated or
Carboxylated Cellulose Surface
[0027] Ca. 1 mg/mL nanoparticles are suspended in water, ethyl
alcohol, or other solvent. The phosphorylated or carboxylated
cellulose textile is added to the suspension and the suspension is
gently mixed over a reaction period of 1 to 12 hours. The textile
is removed from the suspension and subjected to tumble drying or
another drying procedure to force surface condensation and cure
remaining groups.
[0028] The following example discloses modifying UV-blocking
nanoparticles with a self-assembled monolayer (SAM) or polymer
layer containing an active chemical group capable of binding to the
fabric and deposited on the fabric from solution.
EXAMPLE 7
Grafting to Attachment of Cellulose to Nanoparticles Through
Reactive Groups
[0029] In this method, ZnO particles are synthesized separately by
any of the means discussed in Examples 1-3 or the ZnO particles may
be purchased commercially. The ZnO particles are suspended in water
or a weak non-nucleophilic aqueous buffer and an organosilane or
phosphonate with one of the given combinations of reactive groups,
as shown in Table 1, is added. Multidentate ligand or polymeric
silanes may also be added to this mixture to facilitate the
formation of a durable reactive layer and an oxide, alkoxide, or
salt of another metal such as Ti or Si may be added first to form a
surface layer of another oxide in the ZnO particles. After a
reaction time of 1 to 12 hours, the particles are collected by
centrifugation and washed with water. The particles are then
resuspended in water or buffer and added to the textile. The
conditions for binding of the particles to the textile vary
depending on the headgroup, as shown in Table 1, but may involve
direct application of the particles to the textile similarly to the
process disclosed in Example 6, raising the pH of the suspension
containing the textile, or heating the textile either in or after
removal from the suspension. This process has the advantage of
yielding extremely fine control over the nature of the linkage
between particle and textile. This process has a further advantage
in that the treated textile will be durable due to the robustness
of self-assembled siloxane layers on oxide.
TABLE-US-00001 TABLE 1 Molecule name (if commercially Commercially
available) Linker Headgroup available? 3-glycidoxypropyl-
Triethoxysilane Glycidyl ether Yes triethoxysilane
2-(3,4-cyclohexyloxy) Triethoxysilane Cyclohexyl oxide Yes
ethyltriethoxysilane Hydroxymethyl- Triethoxysilane Hydroxymethyl
Yes triethoxysilane Isocyanatopropyl Trimethoxysilane Isocyanate
Yes trimethoxysilane Bis(triethoxysilyl) Triethoxysilane (2) N/A
Yes ethane 6-azidosulfonylhexyl Triethoxysilane Axidosulfonyl Yes
triethoxysilane Triethoxysilane Vinylsulfone No Triethoxysilane
Aryl azide No Phosphonate Glycidyl ether No Phosphonate Cyclohexyl
oxide No Phosphonate Azidosulfonyl No Phosphonate Vinylsulfone No
Phosphonate Aryl azide No Bis(triethoxysilyl) Triethoxysilane (2)
Secondary amine Yes propylamine APTES/EGDE Triethoxysilane
Amine/Ethylene Yes, 2 components glycol diglycidyl ether
[0030] The terms "fabric" or "textile" are intended to include
fibers, filaments, yarn, textiles, material, woven and non-woven
fabric, knits, and finished products such as garments. The methods
described above may be used in treating fibers, filaments, yarn,
textiles, and fabrics. For example, fibers may be initially treated
by use of one or more of the above disclosed methods and the fibers
may be manufactured into a fabric or a textile. Once manufactured
into a fabric, the fabric may be treated by use of one or more of
the disclosed methods. In this manner, individual fibers and the
entire fabric are treated to incorporate UV protection. As can be
appreciated, the treated fabric may be used to manufacture a
garment such as, by way of example only, shirts, pants, hats,
coats, jackets, shoes, socks, uniforms, athletic clothing, and
swimwear. It is also possible and contemplated that the treated
fabric may be used to construct non-apparel items such as blankets,
sheets, sleeping bags, backpacks, and tents.
[0031] Further, it is also possible to further modify ZnO particles
with a thin layer of other oxides in a "core-shell" type procedure
by adding a reactive precursor to a suspension of the ZnO oxides.
Oxides that can be deposited in this manner include SiO.sub.2 from
tetraethoxysilane (TEOS) or sodium silicate, and Al.sub.2O.sub.3
and TiO.sub.2 either from the appropriate alkoxides,
aluminate/titanate compounds, or other hydrolyzable aluminum or
titanium compounds. A second oxide shell of this type may enhance
the formation and stability of both directly applied ZnO-textile
conjugates and those formed by modification of nanoparticles with
an organic monolayer. ZnO can also be modified by the addition of a
multidentate silane along with a silane containing the desired
functional group. The multidentate silane yields a more densely
crosslinked siloxane surface than monodentate silanes alone,
forming a more stable layer on ZnO.
[0032] Although the above examples and methods are applicable to
the manufacturing process in which ultraviolet radiation protection
is incorporated into the fabric, textile, or garment when initially
produced, the following discloses various methods of incorporating
ultraviolet radiation protection directly to clothing being
laundered. By use of the following methods, a garment after
purchase may be made a protected garment by an end user.
[0033] In general, the methods may comprise the self-assembly of
certain polyanionic materials onto a ZnO surface to create a linker
which will bind the particles to a cellulose (cotton) surface.
Several acidic or oxyanion functional groups are capable of
self-assembly onto ZnO. These functional groups include siloxane,
silanol, carboxylic acid, carboxylate, phosphonic acid,
phosphonate, boronic acid or other groups capable of binding to
oxide layers. Boronic acid is capable of forming very strong
interactions with carbohydrates, including the glycosidically
linked glucose units making up cellulose. One method or approach is
to prepare a polymer bearing boronic acid groups and use that
polymer to bind ZnO to cotton.
[0034] Various methods or processes are disclosed herein for the
treatment of fabric to incorporate UV protection in the fabric by
use of a laundry additive. One method is identified as the
cellulose-to-oxide method. A second method is termed the
oxide-to-cellulose method. A third method is described as the free
mixing method.
EXAMPLE 8
The Cellulose-To-Oxide Method
[0035] In this method, cotton garments are pre-treated with boronic
acid polymer resulting in cloth or fabric coated with boronic acid
groups capable of binding to suspended uncoated ZnO particles. A
home washing machine having the capability of adding a substance on
a delayed basis may be used. In particular, boronic acid polymer is
added to laundry detergent or added at the beginning of the laundry
cycle. A suspension of ZnO particles may be added to a compartment
in the washing machine that will dispense the particles on a
delayed basis. For example, several washing machines have a
compartment for storing bleach which is dispensed later on in the
laundry cycle. The suspension of ZnO particles may be placed in the
bleach compartment to be dispensed at the time that bleach would
normally be dispensed into the washing machine. The washing machine
would initially mix the clothing with the boronic acid material.
This will result in the clothing bearing boronate groups. At the
end of the delayed period the washing machine will dispense the
suspension of ZnO particles into the washing machine. The ZnO
particles will bind to the boronate groups and become attached to
the clothing. It is also possible and contemplated that the
suspension of ZnO particles may be manually added to the washing
machine in a delayed manner. Manually adding the suspension may be
required if the washing machine is not equipped with a compartment
for adding bleach on a delayed basis.
EXAMPLE 9
Oxide-To-Cellulose Method
[0036] In this method, ZnO particles are treated with boronic acid
polymer. Once prepared, these particles may be either mixed with
laundry detergent and distributed in that form or sold as a
separate additive that may be added to laundry detergent. The
particles mixed with the laundry detergent or the separate additive
is used in the washing machine as normal. During the course of the
wash cycle, the boronic acid groups attach to the ZnO particles
would assemble on and bind to cotton or other cellulose clothing.
This results in a ultraviolet protected garment.
EXAMPLE 10
Free Mixing Method
[0037] In this method, boronic acid polymer and ZnO particles
(untreated) are incorporated into the laundry detergent preparation
in the solid phase. When added to a laundry cycle or wash cycle the
detergent and water will solubilize these materials causing boronic
acid polymer to assemble on both ZnO and cellulose. This will
result in linked ZnO material. This method may require more boronic
acid polymer and ZnO particles then the more controlled methods
disclosed in Examples 8 and 9 to yield adequate grafting densities
of ZnO on clothing.
[0038] Use of any of the methods disclosed in Examples 8, 9, or 10
will result in ZnO particles being bound to the fabric that is
being washed in a conventional household washing machine. Once the
ZnO particles are bound to the fabric, the fabric will have
incorporated therein ultraviolet radiation protection. It is also
possible and contemplated that the various methods described in
Examples 8, 9, and 10 may be used more than once to incorporate
ultraviolet radiation protection into clothing. For example,
clothing may be treated by use of one or more of these methods and
over time and after numerous washings the ultraviolet radiation
protection may diminish. If there is any concern about the
ultraviolet radiation protection of the garment, the garment may be
washed using the various methods discussed in Examples 8, 9, and
10. Further, it is possible that a consumer may purchase a garment
that has been treated using the methods described in Examples 1-7.
Again, over time the ultraviolet radiation protection of the
garment may decline. The consumer may use the methods disclosed in
Example 8, 9, and 10 to wash the garment to again incorporate
ultraviolet radiation protection into the garment.
[0039] All synthetic material such as polyester and nylon that is
used in the manufacture of athletic clothing or active wear
clothing may be rendered UV-absorbing using a ZnO preparation.
These types of fabrics may resist treatment using the methods as
outlined with respect to Examples 8, 9, and 10. One solution to
this problem is to prepare ZnO particles coated with functional
groups capable of being grafted directly to polyester or nylon
materials. This may be accomplished by using benzophenone
photografting chemistry. The following examples and methods are
applicable to the manufacturing process in which ultraviolet
radiation protection is incorporated into the artificial or
synthetic fabric, textile, or garment when initially produced.
[0040] The following methods provide for the direct grafting of ZnO
particles to nonpolar, non-natural polymers such as nylon and
polyester. Nylon and polyester have little in the way of chemical
functionality, containing only alphatic and aromatic C-H bonds and
amide or ester linkages between monomers. The method is capable of
directly functionalizing C-H bonds. The following method describes
preparing ZnO particles coated with functional groups capable of
being grafted directly to polyester or nylon materials by using the
photografting reaction of benzophenone.
EXAMPLE 11
Grafting ZnO onto Artificial or Synthetic Fibers
[0041] In this method, an artificial fabric composed of polyester,
nylon, or other polymer lacking hydroxyl functional group is
modified by use of a preparation of a zinc oxide particle modified
with a layer of reactive groups capable of C-H activation. Examples
of the reactive functional group capable of C-H activation are
benzophenone, sulfonylazides, aryl azides, or diazonium salts. The
prepared particles are coated onto the fabric and a reaction is
initiated using UV light, heat, or both. By way of example only, a
mercury-vapor UV lamp may be used and the time for exposure may be
one hour. Unbound particles are washed off the fabric. This second
step, a curing step, bonds the prepared particles to the fabric.
This method adds a second UV-absorbing chromophore which
cross-links and becomes further bonded to the polymer surface of
the fabric upon exposure to UV light. In this method, zinc oxide
particles can be composed of pure zinc oxide or zinc oxide coated
with aluminum, titanium, or silicon oxides in a core-shell
configuration. The result is an artificial fabric with photografted
zinc oxide particles.
[0042] By way of example, the zinc oxide particles were prepared in
the following manner. Five grams of zinc oxide nanoparticles were
used and suspended in a solution of 98% ethyl alcohol. Two grams of
benzophenone silane linker were suspended in this solution and the
pH of the solution was adjusted to 12. After 12 hours, the zinc
oxide particles were recovered by centrifugation and dried
overnight at 50-60.degree. C. in an oven.
[0043] It is also possible to prepare a phosphoether of
4-hydroxybenzophenone and use this self-assembling molecule to
functionalize ZnO particles. The resulting particles, having a
monolayer of nonpolar molecules, will be substantially nonpolar and
will adhere to nonpolar polyester and nylon. In order to bond the
particles to the polymer surface an UV light may be used to
initiate a reaction. Again, the process has the advantage of adding
a second UV absorbing chromophore which cross-links and becomes
further bonded to the polymer surface upon exposure to UV
light.
[0044] It is also known that some cotton fabrics or yarns are
mercerized through a series of processes to add luster to the
fabrics or yarns. The mercerization process typically requires that
cotton be held under tension for a specific amount of time while
having between 21%-23% caustic soda (NaOH) applied to the cotton at
room temperature. The process may include neutralizing the cotton
by washing with water or by using an acid bath. Once the process is
completed, the cotton fabric or yarn has increased luster,
increased strength, is easier to dye, and resists mildew. However,
the treated cotton does not include any ultraviolet radiation
protection.
[0045] Although the above examples and methods are applicable to
the manufacturing process in which ultraviolet radiation protection
is incorporated into the fabric, textile, or garment when initially
produced, the following discloses various methods of incorporating
ultraviolet radiation protection into mercerized cotton. By use of
the following methods, mercerized fabric, textile, or a garment may
be made an ultraviolet radiation protected fabric, textile, or
garment for an end user. In the following examples and the claims
appended hereto, the word or term "cotton" is intended to mean or
include fibers, filaments, yarn, textiles, material, woven and
non-woven fabric, knits, and finished products such as
garments.
[0046] In general, the methods may comprise impregnating cotton
with ZnO that involves treating the textile with aqueous Zn(II)
solution followed by addition of ca. 2M NaOH solution with
subsequent washing steps. By use of the following methods it is
possible to incorporate ultraviolet radiation protection into
mercerized cotton.
EXAMPLE 12
Pretreatment
[0047] In this method, cotton is pretreated with a solution of NaOH
followed by transfer to Zn(II) solution. The pretreatment step is
to place the cotton in a concentrated mercerization strength NaOH
solution before placing the cotton into Zn(II) solution. Since
mercerization generally greatly enhances absorption of dyes on
cellulose, the cotton will readily incorporate the deposition of
ZnO on or in the mercerized cotton. After the cotton is treated in
the Zn(II) solution, a solution of ca. 2M NaOH may be added. After
a sufficient time, the cotton is removed from the NaOH solution and
may be washed or rinsed and then dried. It is possible that the
cotton may be washed or rinsed more than once.
EXAMPLE 13
Treatment of Cotton Followed by Neutralization
[0048] In this method, cotton is swelled with a strong NaOH
solution and after the optional step of pressing and/or stretching
the cotton as part of the mercerization process, the cotton is
transferred to a Zn(II) solution. Retained NaOH in the cotton
reacts with the Zn(II), depositing ZnO on the cotton and in the
fibers of the cotton. After a sufficient time, the cotton is
removed from the Zn(II) solution, washed or rinsed, and then
allowed to dry. This method does not require an acid recycling
step.
EXAMPLE 14
Mercerized Cotton
[0049] In this method, previously mercerized cotton is used. The
mercerized cotton is placed into a Zn(II) solution. The ZnO is
deposited on the cotton and in the fibers of the cotton. The cotton
is removed from the Zn(II) solution after a period of time, washed
or rinsed, and then allowed to dry.
[0050] The solution of Zn(II) or the ZnO nanoparticles may be
produced by any of the methods described above in Examples 1-3 to
be used in Examples 12-14.
[0051] From all that has been said, it will be clear that there has
thus been shown and described herein a fabric having ultraviolet
radiation protection incorporated into the fabric which fulfills
the various advantages sought therefore. It will become apparent to
those skilled in the art, however, that many changes,
modifications, variations, and other uses and applications of the
subject fabric having ultraviolet radiation protection incorporated
into the fabric are possible and contemplated. All changes,
modifications, variations, and other uses and applications which do
not depart from the spirit and scope of the disclosure are deemed
to be covered by the disclosure, which is limited only by the
claims which follow.
* * * * *