U.S. patent application number 10/687814 was filed with the patent office on 2004-04-01 for chemical resistant, water and dry particle impervious, flame resistant laminate.
This patent application is currently assigned to PRECISION FABRICS GROUP. Invention is credited to Cox, William C., Harris, Philip E..
Application Number | 20040063371 10/687814 |
Document ID | / |
Family ID | 23131695 |
Filed Date | 2004-04-01 |
United States Patent
Application |
20040063371 |
Kind Code |
A1 |
Cox, William C. ; et
al. |
April 1, 2004 |
Chemical resistant, water and dry particle impervious, flame
resistant laminate
Abstract
Disclosed is a laminate having flame and chemical resistance,
which may be used to form protective fabrics. The laminate contains
a first layer of a spunlace fabric having a fire retardant additive
applied thereto; and a second layer of a polymeric film.
Inventors: |
Cox, William C.; (Highpoint,
NC) ; Harris, Philip E.; (Highpoint, NC) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER
LLP
1300 I STREET, NW
WASHINGTON
DC
20005
US
|
Assignee: |
PRECISION FABRICS GROUP
|
Family ID: |
23131695 |
Appl. No.: |
10/687814 |
Filed: |
October 20, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10687814 |
Oct 20, 2003 |
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09294056 |
Apr 19, 1999 |
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60082330 |
Apr 20, 1998 |
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Current U.S.
Class: |
442/396 ;
442/136; 442/153; 442/164; 442/394; 442/408 |
Current CPC
Class: |
Y10T 442/676 20150401;
Y10T 442/2631 20150401; Y10T 442/681 20150401; Y10T 442/68
20150401; B32B 27/12 20130101; Y10T 442/2713 20150401; Y10T 442/674
20150401; B32B 7/12 20130101; B32B 2571/02 20130101; Y10T 442/2869
20150401; B32B 2327/06 20130101; Y10S 428/92 20130101; B32B
2262/0276 20130101; B32B 2262/04 20130101; A41D 31/10 20190201;
Y10T 442/277 20150401; Y10T 442/2787 20150401; A41D 31/085
20190201; B32B 27/18 20130101; C09K 21/14 20130101; B32B 27/304
20130101; B32B 2307/3065 20130101; Y10T 442/2861 20150401; Y10S
428/921 20130101; B32B 2437/00 20130101; Y10T 442/689 20150401 |
Class at
Publication: |
442/396 ;
442/136; 442/408; 442/153; 442/164; 442/394 |
International
Class: |
B32B 027/12; B32B
005/02; B32B 009/04; B32B 027/30; D04H 005/02; D04H 003/10; B32B
027/02; B32B 027/04 |
Claims
We claim:
1. A laminate comprising: (a) a first layer of a nonwoven fabric
having a fire retardant additive applied thereto; and (b) a second
layer containing a flame resistant polymeric film.
2. The laminate of claim 1, wherein the nonwoven fabric is spunlace
fabric.
3. The laminate of claim 2, wherein the spunlace fabric comprises
cellulose fibers and manmade fibers.
4. The laminate of claim 2, wherein the spunlace fabric comprises
cellulose fibers and polyester fibers.
5. The laminate of claim 2, wherein the spunlace fabric comprises
wood pulp fibers and polyester fibers.
6. The laminate of claim 1, wherein the laminate has a thickness
ranging from about 0.001 to about 0.5 inches.
7. The laminate of claim 1, wherein the first and second layer are
joined together by an adhesive.
8. The laminate of claim 1, wherein the first and second layers are
joined together by ultrasonic lamination, R.F. sealing, adhesive
lamination, or heat bonding with pressure.
9. The laminate of claim 1, wherein the polymeric film is
halogenated.
10. The laminate of claim 1, wherein the polymeric film comprises
polyvinyl chloride.
11. The laminate of claim 1, wherein the polymeric film has a
thickness ranging from about 0.3 to about 8.0 mils.
12. The laminate of claim 1, wherein the fire retardant additive is
ammonium polyphosphate, ammonium dihydrogen phosphate, urea
polyammonium phosphate, antimony trioxide, sodium antimonate, zinc
borate, a zirconium oxide, a molybdenum oxide, a zirconium sulfide,
or a molybdenum sulfide.
13. The laminate of claim 1, wherein the fire retardant additive is
a chlorinated paraffin, tetrabromobisphenol-A, decabromodiphenyl
oxide, hexabromodiphenyl oxide, pentabromobiphenyl oxide,
pentabromotoluene, pentabromoethylbenzene, hexabromobenzene,
pentabromophenol, tribromophenol derivatives,
perchloropentanecyclodecane, hexabromocyclodecane,
tris(2,3-dibromopropyl-1)isocyanurate, tetrabromobisphenol-S,
1,2-bis(2,3,4,5,6-pentabromophenoxy)ethane,
1,2-bis(2,4,6-tribromophenoxy)ethane, a brominated styrene
oligomer, 2,2-bis-(4(2,3-dibromopropyl)-3,5-dibromophenoxy)propane,
tetrachlorophthalic anhydride, and tetrabrornophthalic
anhydride.
14. The laminate of claim 1, wherein the fire retardant additive is
applied to the first layer at about 5 to about 45 percent by weight
of the first layer.
15. The laminate of claim 1, that passes NFPA 701-1989, has at
least 12.0 lbs of grab tensile according to INDA IST 110.3-92, and
a Suter hydrostatic head of at least 50 cm.
16. A protective garment formed of the laminate of claim 1.
17. A laminate comprising: (a) a first layer of a spunlace fabric
containing cellulose and manmade fibers, the first layer having a
fire retardant additive applied thereto; (b) a second layer of a
polyvinyl chloride film.
18. The laminate of claim 17, wherein said first and second layers
are joined together by an adhesive.
19. The laminate of claim 17, wherein the laminate has a thickness
ranging from about 0.001 to about 0.5 inches.
20. The laminate of claim 17, wherein the fire retardant additive
is ammonium polyphosphate, ammonium dihydrogen phosphate, urea
polyammonium phosphate, antimony trioxide, sodium antimonate, zinc
borate, a zirconium oxide, a molybdenum oxide, a zirconium sulfide,
or a molybdenum sulfide.
21. The laminate of claim 17, wherein the fire retardant additive
is applied to the first layer at about 5 to about 45 percent by
weight of the first layer.
22. The laminate of claim 17, that passes NFPA 701-1989, has at
least 12.0 lbs. of grab tensile according to INDA IST 110.3-92, and
a Suter hydrostatic head of at least 50 cm.
23. A protective garment formed of the laminate of claim 17.
Description
FIELD OF INVENTION
[0001] Our discovery relates to laminates which may be used for
garments, which are chemical and flame resistant, and are
impervious to dry particles.
BACKGROUND OF INVENTION
[0002] With multiple safety concerns, coupled with hazards and
liabilities that are associated with today's industrial working
environment, there is a need for a material that is impervious to
water and dry particles, resistant to chemical breakthrough, and
resistant to flames. Typically, available materials have only some
of the above-mentioned properties, or are constructed of very heavy
and expensive materials. Existing products normally target one area
of industrial protection. For example, DuPont's Tychem.RTM. is
described by the manufacturer as a high-performance protective
material for garments. While Tychem.RTM. may provide protection
against various liquid chemicals, it is not a flame resistant
material. In fact, Tychem.RTM.) is sold with a warning that the
product should not be used around heat, flames, sparks, or in
potentially flammable or explosive environments.
[0003] Although some products may be both flame and chemical
resistant, those products are generally costly to make and/or have
other disadvantages. For example, U.S. Pat. No. 5,491,022 relates
to a product having a plastic laminate formed by coextruding at
least two layers of polymeric sheets with an intermediate layer of
a polar resin or hydrophilic polymer. The plastic laminate is then
adhered to a fabric scrim formed of polyester and cellulosic fibers
treated with fire retardant and antistatic agents. The product
described in the '022 patent, however, has a thickness of at least
125 mils, and is, therefore, undesirably thick and heavy.
OBJECTS OF THE INVENTION
[0004] An object of the invention is to provide a material that is
fire retardant.
[0005] Another object of the invention is to provide a material
that is resistant to chemicals.
[0006] Another object of the invention is to provide a material
that is relatively light weight and has structural integrity
sufficient to form a protective garment.
SUMMARY OF THE INVENTION
[0007] To achieve these and other objectives, and in accordance
with the purpose of our invention as embodied and broadly described
herein, in one aspect we describe a laminate containing a first
layer of a nonwoven fabric having a fire retardant additive applied
thereto; and a second layer containing a polymeric film.
[0008] In another aspect, we describe a laminate having a first
layer of a nonwoven fabric containing cellulose and manmade fibers,
the first layer having a fire retardant additive applied thereto;
and a second layer of a polyvinyl chloride film.
DETAILED DESCRIPTION OF THE INVENTION
[0009] We have found that the desired physical properties can be
obtained by combining a fire retardant finished nonwoven fabric
with a barrier film. The barrier film may have at least some degree
of flame resistance or may contain a fire retardant additive. The
resulting material, referred to herein as a "laminate," is
resistant to certain chemicals in liquid, vapor, or solid form, and
is also flame resistant. The laminate is also impervious to water
and dry particles.
[0010] As used herein, "flame resistant" refers to the ability of
the fabric to pass at least one flame resistance test set forth by
the National Fire Protection Association in "NFPA 701 Standard
Methods of Fire Tests for Flame-Resistant Textiles and Films," 1996
Ed. and "NFPA 701 Standard Methods of Fire Tests for
Flame-Resistant Textiles and Films," 1989 Ed. The entire contents
of each of those publications are incorporated herein by
reference,
[0011] Preferably, the laminate has a first layer that is a
nonwoven fabric. Examples of nonwoven fabrics include spunbond
fabrics, resin bonded fabrics, thermal bonded fabrics, air-laid
pulp fabrics, and stitchbonded fabrics. More preferably, the
nonwoven fabric is a spunlace fabric made from a combination of
cellulosic and manmade fibers. Cellulosic fibers that may be used
to form the spunlace fabric include woodpulp fibers, cotton fibers,
regenerated cellulose fibers such as Rayon.RTM. (obtained from
DuPont) or Lyocell.RTM. (obtained from DuPont, cellulose acetate
fibers, cellulose triacetate fibers, jute, hemp and any bast, leaf,
or stem fibers. Preferably, woodpulp fibers are used.
[0012] Manmade fibers that may be used to form the spunlace fabric
include polyester, nylon, or acrylic fibers. When combining the
manmade fibers and cellulosic fibers to form the spunlace fabric,
it is convenient for the cellulosic and manmade fibers to be in the
form of flat layers. Preferably, the celluosic fibers are in the
form of sheets of paper and the manmade fibers are in the form of
an air-laid web of staple fibers or a nonwoven sheet of
substantially continuous filaments. The webs or sheets may be
bonded or nonbonded. Preferably, the weight ratio of the cellulosic
fibers to manmade fibers ranges from 75:25 to 25:75, more
preferably from 65:35 to 50:50.
[0013] The weight of the spunlace fabric used in the laminate is
determined by the degree of dimensional stability needed as well as
wear durability needed in protective apparel applications. A
preferred weight range for the spunlace fabric is 1.0 osy to 4.0
osy. An example of a spinlace woodpulp/polyester fabric that can be
used to form the laminate is sold by DuPont under the tradename
Sontara.RTM..
[0014] As mentioned, the nonwoven fabric used in the laminate is
preferably formed by a spunlace process. Examples of spunlace
processing are well known in the art. For example, a pulp
containing cellulosic fibers may be applied to one side of a batt
of carded manmade fibers. The material is then passed under a
plurality of water jets, which entangle the manmade and cellulosic
fibers to form a fabric. Methods of making the spunlace fabric are
described in U.S. Pat. No. 4,442,161, the entire contents or which
are incorporated herein by reference.
[0015] A fire retardant additive is applied to the spunlace fabric,
at a preferred dry solids add-on ranging from about 5 to about 45
percent by weight of the spunlace fabric. Preferably, the dry
solids add-on ranges from about 15 to about 25 percent by weight of
the spunlace fabric. Any well-known inorganic fire retardant
additives can be used, including ammonium polyphosphates, ammonium
dihydrogen phosphate, antimony trioxide, sodium antimonate, zinc
borate, zirconium oxides, diammonium phosphate, sulfamic acid,
salts of sulfamic acid, boric acid, salts of boric acid, and
hydrated alumina.
[0016] Exemplary organic fire retardant additives that may be used
include urea polyammonium phosphate, chlorinated paraffins,
tetrabromobisphenol-A and oligomers thereof, decabromodiphenyl
oxide, hexabromodiphenyl oxide, pentabromodiphenyl oxide,
pentabromotoluene, pentabromoethylbenzene, hexabromobenzene,
pentabromophenol, tribromophenol derivatives,
perchloropentanecyclodecane, hexabromocyclodecone,
tris(2,3-dibromopropyl-1)isocyanurate, tetrabromobisphenol-S and
derivatives thereof, 1,2-bis(2,3,4,5,6-pentabromophenoxy)ethane,
1,2-bis-(2,4,6-tribromophenoxy)ethane, brominated styrene
oligomers, 2,2-bis-(4(2,3-dibromopropyl)3,5-dibromophenoxy)propane,
tetrachlorophthalic anhydride, and tetrabromophthalic
anhydride.
[0017] Any combination of fire retardant additives, whether
inorganic or organic, may be used. A preferred fire retardant
additive is a phosphate, such as Spartan 880.RTM. sold by Spartan
Flame Retardants. The fire retardant additive may be applied to the
spunlace fabric by any conventional method such as spraying,
contacting the spunlace fabric with a saturation pad or saturation
roller, a dip/nip saturation process, gravure coating, or kiss
coating.
[0018] The nonwoven fabric, either before or after it is treated
with a fire retardant, is laminated to a polymeric film which
serves as a barrier against liquids, solids, and gases. The
polymeric film may be selected so that by itself it has at least
some degree of flame resistance. This property of flame resistance
for the polymeric film may be measured by flame testing or by
determining its limiting oxygen index. Accordingly, the polymeric
film may be made from halogenated films such as polyvinyl chloride,
polyvinyl bromide, or polyvinylidene chloride. As an alternative, a
polymeric film may be used which, by itself, is not flame
resistant, but is rendered flame resistant by the application of
fire retardant additives.
[0019] A preferred polymeric film is polyvinyl chloride. Polymeric
film thickness could range from about 0.1 mils to about 8.0 mils,
with the preferred range being about 0.2 mils to about 6.0 mils.
The polymeric film thickness depends on the end use, and may be
optimized to control the laminate's strength, abrasion resistance,
and barrier properties for an intended end use while being cost
effective. Similarly, the weight of the polymeric film is
determined by the degree and type of chemical resistance needed, as
well as the needed cost fit to the specific end use. The weight of
the polymeric film ranges from about 0.05 to about 10.0 ounces per
square yard. A more preferred weight for the polymeric film ranges
from about 0.15 to about 5.0 ounces per square yard.
[0020] The film and the fabric can be attached to one another in
many ways, including ultrasonic lamination, R.F. sealing, adhesive
lamination, and heat bonding with pressure. Proper bonding may
enhance the laminate's ability to hinder the propagation of a
flame.
[0021] Preferably, the nonwoven fabric is bonded to the polymeric
film via a moisture curable polyurethane adhesive. An example of a
polyurethane adhesive is XPU 51018M PUR.RTM. which may be obtained
from ATO Findley, Inc. The adhesive may be applied to a surface of
either the spunlace fabric or the polymeric film by a hot met slot
coater. Generally, the adhesive is applied at temperatures ranging
from about 150 to about 250.degree. F. The temperature may be
controlled to optimize the viscosity of the adhesive for proper
flow through the slot dies. Other adhesives that may be used
include, for example, pressure sensitives, polyesters, polyamides,
polyolefins and thermoplastic polyurethanes.
[0022] The laminate may also contain additional layers. For
example, the chemical resistance of the laminate may be enhanced by
the addition of another layer of a dissimilar polymeric film. An
additional polyethylene layer may be added to enhance protection
against polar solvents, i.e., solvents having relatively high
dielectric strengths. As another example, a layer of a conventional
ethylene vinyl alcohol may be added to improve further the solvent
repellancy of the laminate.
[0023] The formed laminate therefore has a preferred thickness of
about 0.001 to about 0.5 inches, more preferably about 0.005 to
about 0.05 inches. The formed laminate's weight may range from
about 0.5 to about 10.0 ounces per square yard, and more
preferably, from about 1.0 to about 8.0 ounces per square yard.
EXAMPLE 1
[0024] A phosphate fire retardant additive, sold as Spartan
880.RTM., was applied to a 2.13 osy Sontara.RTM.) DuPont spunlace
wood pulp/polyester fabric. The fabric was then dried on a pin
tenter. The dry solids add-on of the Spartan 880.degree. was 27
percent by weight of the fabric. A 0.5 mil polyvinyl chloride film
was then bonded to the woodpulp side of the spunlace fabric by
application of 3.0 gsm add-on of a hot melt moisture curable
urethane to form a laminate. The urethane was applied using a hot
melt slot coater maintained at a temperature from 150 to
250.degree. F. The finished basis weight of the laminate was
approximately 2.95 osy.
[0025] Properties of the laminate are shown below in Table 1. In
both Tables 1 and 2 below, the basis weight was determined by INDA
Standard Test 130.1-92, the thickness was determined by IST
120.1-92, the cured bond strengths by IST 110.2-82, the grab
tensile strengths by IST 110.3-92, the static decays by IST
40.2-92, the trap tears by IST 100.2-92, the resistivity by AATCC
76-1978, the flame char lengths by NFPA 701-1989, the flame weight
loss by NFPA 701-1996, the Mullen Burst by ASTM D3786-87 and Suter
Hydrostatic by INDA IST 80.4(95), and the Taber Abrasion by ASTM
D3884-80. All data shown in Table 1 is the calculated mean.
1TABLE 1 Physical Properties of Laminate Having 0.5 Mil PVC Layer
Cured Bond Cured Bond Grab Grab Basis Strength Strength- Tensile-
Tensile Weight Thickness MD XD MD XD Static Static (oz/sq. yd.)
(in.) (grams/in) (grams/in.) (lb.) (lb.) Decay-MD Decay-XD 2.92
9.014 238 245 34.2 25.2 0.01 0.00 Flame Flame Char Flame Char
Weight Mullen Taber Trap Trap Length- Length- Loss- Burst Abrasion
Suter Tear-MD Tear-XD Resistivity MD (in.) XD (in.) MD (%)
(lb.f/sq. in.) (cycles) Hydrostatic 7.2 7.9 3.55E+14 4.1 4.0 23.7
27.2 500 >50 cm
EXAMPLE 2
[0026] A laminate was formed by the same method described in
Example 1, except a 2.0 mil polyvinyl chloride film was used as the
polymeric film. Properties of the laminate are shown below in Table
2. All data shown in Table 2 is the calculated mean.
2TABLE 2 Physical Properties of Laminate Having 2.0 Mil PVC Layer
Cured Bond Cured Bond Grab Grab Basis Strength- Strength- Tensile
Tensile Weight Thickness MD XD MD XD Static Static (oz/sq. yd.)
(in.) (grams/in.) (grams/in.) (lb.) (lb.) Decay-MD Decay-XD 4..25
0.015 94 126 43.5 33.6 0.01 0.00 Flame Flame Char Flame Char Weight
Mullen Taber Trap Trap Length- Length- Loss Burst Abrasion Suter
Tear-MD Tear-XD Resistivity MD (in.) XD (in.) MD (%) (lb.f/sp. in.)
(cycles) Hydrostatic 7.2 10.3 31.0E+12 4.6 4.3 23.6 33.0 500
>100 cm
EXAMPLE 3
[0027] Laminates were made by the same method of Example 1 having a
0.5 mil polyvinyl chloride layer and a 2.0 mil polyvinyl chloride
layer. The chemical penetration resistance for each laminate was
tested by the method taught in ASTM F903-87. Procedure C and the
results are shown in Table 3 below,
3TABLE 3 Chemical Penetration of Laminates Laminate Having Laminate
Having 0.5 mil PVC Layer 2.0 mil PVC Layer Acetone Pass Pass
Acetonitrite Pass Pass Carbon Disulfide Pass Pass Dichloromethane
Fail Fail Diethylamine Fail Pass Dimethylformamide Fail Fail Ethyl
acetate Pass Pass Hexane Pass Pass Methanol Pass Pass Nitrobenzene
Fail Fail Sodium hydroxide Pass Pass Sulfuric Acid Fail Fail
Tetrachloroethylene Pass Pass Tetrahydrofuran Fail Fail Toluene
Pass Pass
[0028] The laminates described herein should be useful for
protective garments used in heavy Industry (e.g. welding, equipment
manufacturing), hazardous chemical remediation, general laboratory
work, electrical utilities (rainware, fire protection), the
petrochemical industry, pesticide applications, and painting.
Examples of protective garments formed by the laminate include
gloves, headgear, jackets, trousers, and shoes.
[0029] Additionally, the laminates described herein may be formed
into protective covers for machinery or equipment, Regardless of
the specific end use, the laminate may be used by Itself or in
conjunction with other protective materials.
[0030] It will be apparent to those skilled in the art that various
modifications and variations can be made in the laminate and
methods disclosed above without departing from the spirit of our
discovery. Thus, it is intended that our description covers the
modifications and variations of this invention provided that they
come within the scope of the appended claims and their
equivalents.
* * * * *