U.S. patent application number 10/647917 was filed with the patent office on 2005-03-03 for low emission fibrous webs and method of such webs.
Invention is credited to Miele, Philip Francis.
Application Number | 20050048272 10/647917 |
Document ID | / |
Family ID | 34104656 |
Filed Date | 2005-03-03 |
United States Patent
Application |
20050048272 |
Kind Code |
A1 |
Miele, Philip Francis |
March 3, 2005 |
Low emission fibrous webs and method of such webs
Abstract
A nonwoven web of polymer fibers bonded with from about 5 to
about 30 wt. percent of a cured binder composition, based on the
weight of the web or mat. The web is a spunbonded web of polymer,
such as polyester, fibers bound with a binder containing one or
more formaldehyde fortified polymer resins that normally emit
substantial formaldehyde at high temperatures, but in this
invention the binder also contains up to about 7.5 wt. percent of a
bisulphite compound, preferably ammonium bisulphite. This binder is
applied in latex form to the fibrous web after the fibers are made
and collected in a known manner and then the wet web is dried and
heated to cure the binder in a known manner. The resultant nonwoven
webs have good hot strength and low formaldehyde emissions and
reasonable costs, something not heretofore attainable with these
types of formaldehyde containing binders. The webs of the present
invention are useful for making various roofing products such as
built up roofing products and for other uses.
Inventors: |
Miele, Philip Francis;
(Highlands Ranch, CO) |
Correspondence
Address: |
Robert D. Touslee
JOHNS MANVILLE
Legal Departmet
10100 West Ute Avenue
Littleton
CO
80127
US
|
Family ID: |
34104656 |
Appl. No.: |
10/647917 |
Filed: |
August 26, 2003 |
Current U.S.
Class: |
428/292.1 |
Current CPC
Class: |
C08F 8/34 20130101; C08L
67/00 20130101; D04H 1/64 20130101; C08L 25/12 20130101; C08L
23/0853 20130101; C08L 33/06 20130101; C08L 2666/04 20130101; C08K
5/07 20130101; C08L 25/10 20130101; D04H 3/12 20130101; C08L 67/00
20130101; Y10T 428/249924 20150401; D04H 1/587 20130101 |
Class at
Publication: |
428/292.1 |
International
Class: |
D04H 001/00 |
Claims
1. A web of polymer fibers bound by about 5-30 wt. percent, based
on the dry weight of the mat, of a formaldehyde containing polymer
resin latex binder providing good hot strength at 200 degrees C.
and good elasticity to the web, the resin containing at least about
0.75 wt. percent and up to about 7.5 wt. percent of a bisulfite
compound, based on the dry weight of the formaldehyde containing
resin in the binder.
2. The web of claim 1 wherein the resin is selected from the group
consisting of formaldehyde fortified latex polymers which may be
composed of ethylene-vinyl acetate copolymer, styrene-acrylic
copolymer, vinyl-acrylic copolymer, styrene-butadiene-acrylonitrile
copolymer, or acrylic copolymer.
3. The web of claim 2 wherein the bisulfite is ammonium
bisulfite.
4. The web of claim 3 wherein the bisulfite is ammonium
bisulfite.
5. The web of claim 1 wherein the bisulfite compound is present in
an amount of at least 1.25 wt. percent.
6. The web of claim 2 wherein the bisulfite compound is present in
an amount of at least 1.25 wt. percent.
7. The web of claim 3 wherein the bisulfite compound is present in
an amount of at least 1.25 wt. percent.
8. The web of claim 1 wherein the bisulfite compound is present in
an amount of at least 2.5 wt. percent.
9. The web of claim 2 wherein the bisulfite compound is present in
an amount of at least 2.5 wt. percent.
10. The web of claim 3 wherein the bisulfite compound is present in
an amount of at least 2.5 wt. percent.
11. The web of claim 8 wherein the polymer fibers are polyester,
the ammonium bisulfite compound is ammonium bisulfite, the binder
content of the web is in the range of about 16-24 wt. percent and
the basis weight of the web is in the range of about 150-200
gms/sq. meter.
12. The web of claim 9 wherein the polymer fibers are polyester,
the ammonium bisulfite compound is ammonium bisulfite, the binder
content of the web is in the range of about 16-24 wt. percent and
the basis weight of the web in the range of about 150-200 gms/sq.
meter.
13. The web of claim 10 wherein the polymer fibers are polyester,
the ammonium bisulfite compound is ammonium bisulfite, the binder
content of the web is in the range of about 16-24 wt. percent and
the basis weight of the web is in the range of about 150-200
gms/sq. meter.
14. A method of making a polymer fiber web by melting a polymer,
converting the melt to fibers, attenuating the fibers to the
desired fiber diameter, collecting the fibers in a random pattern
on a collecting surface, applying a latex formaldehyde containing
polymer resin binder to the web in an amount that the binder
content of the dry web will be in the range of about 5-30 wt.
percent, based on the weight of the dry web, and drying the web and
curing the polymer resin binder to bond the polymer fibers together
to form a nonwoven polymer fiber web, said polymer resin being
selected from the group consisting of formaldehyde fortified latex
polymers which may be composed of ethylene-vinyl acetate copolymer,
styrene-acrylic copolymer, vinyl-acrylic copolymer,
styrene-butadiene-acrylonitrile copolymer, or acrylic copolymer,
the improvement comprising adding about 0.75-7.5 wt. percent, based
on the dry weight of the formaldehyde containing resin, of a
bisulfite compound to the latex binder before applying the latex
binder to the collected polymer fibers.
15. The method of claim 14 wherein about 1.25-7.5 wt. percent of
the bisulfite compound is added to the latex binder before applying
the latex binder to the collected polymer fibers.
16. The method of claim 14 wherein about 2.5-5 wt. percent of the
bisulfite compound is added to the latex binder before applying the
latex binder to the collected polymer fibers.
17. The method of claim 14 wherein the polymer is polyester and the
bisulfite compound is ammonium bisulfite.
18. The method of claim 15 wherein the polymer is polyester and the
bisulfite compound is ammonium bisulfite.
19. The method of claim 16 wherein the polymer is polyester and the
bisulfite compound is ammonium bisulfite.
Description
[0001] This invention involves webs of polymer fibers containing
latex binder modified with formaldehyde containing crosslinkers in
which the formaldehyde component is chemically bound and that
display substantially reduced formaldehyde emissions during the
drying, curing and further processing and storing of the webs. The
webs of the invention also have good hot strength. The invention
also involves the method of making polymer fiber webs having
substantially lower formaldehyde emissions and substantially lower
formaldehyde emissions when later processed at elevated
temperatures to produce other products like asphaltic roofing
products.
BACKGROUND
[0002] It is known to make polymer fibrous mats for use in making
asphaltic and modified asphaltic roofing products like roll roofing
products by bonding inorganic fibers or polymer together with a
latex binder such as an SBR or acrylic type latex containing
crosslinking ingredients that emit formaldehyde when dried and
cured at an elevated temperature and when later processed with hot
asphaltic material to make roofing products, or when subjected to
hot, humid conditions. Such ingredients are crosslinking agents
employed to improve cured physical binder properties through
functional groups, usually incorporated into the latex polymer
backbone by copolymerization of N-methylol acrylamide, N-methylol
methacrylamide, or the addition of resins that contain N-methylol
functional groups that are either chemically blocked or unblocked.
Also, other binders including melamine formaldehyde resin mixed
with copolymers of styrene, butadiene, acrylic acid and acrylamide
and other catalysts and functional additives have been used as a
binder in spunbond roofing webs. The resin binders provide Thermal
Dimensional Stability to the webs to reduce stretching in the
machine direction and cross machine direction shrinkage, necking
down, when the webs are impregnated or coated with hot asphalt.
Such a process and products are disclosed in U.S. Pat. Nos.
3,967,032, 4,125,663. A disadvantage of these binders and products
is that they emit formaldehyde vapors when heated in the drying and
curing operation during manufacturing of the Spunbond webs or by
hot asphalt.
[0003] It is also known to add certain known formaldehyde
scavengers to binders containing resins that contain formaldehyde
to reduce emissions. U.S. Pat. No. 5,578,371 teaches adding urea,
melamine, dicyandiamide and/or 1-10 wt. percent of a water-soluble
bisulfite or precursor to urea extended phenol formaldehyde binders
in the manufacture of fiber glass insulation products, which
products are not later coated or impregnated with hot asphalt.
[0004] U.S. Pat. No. 5,795,933 also teaches adding a bisulfite such
as sodium bisulfite, ammonium bisulfite or calcium bisulfite as a
formaldehyde scavenger to an urea extended phenolic resin systems
employing amino-group-containing formaldehyde scavengers in the
manufacture of glass fiber products like thermal insulation.
[0005] U.S. Pat. No. 5,160,679 teaches using acetoacetamide as an
effective formaldehyde scavenger in the manufacture of wood
particleboard and durable press finished fabrics that use urea
formaldehyde as a binder. U.S. Pat. No. teaches using such
formaldehyde scavengers as diethylene glycol, sorbitol, urea,
melamine, diazine, triazine, and a water-soluble active methylene
compound in the manufacture of durable press finished fabrics and
wood particleboard.
[0006] U.S. Pat. No. 5,612,405 teaches glass fiber products bonded
with a binder containing an aqueous compatible formaldehyde resin
like phenolic resin, an aqueous latex elastomeric polymer like
styrene butadiene, ethylene propylene monomer, ethylene
propylene-diene terpolymer, etc., an acrylic polymer like
copolymers of acrylic acid, methacrylic acid acrylic or methacrylic
acid esters from 1-4 carbon atoms, acrylamide polymers or
copolymers and esters thereof of from 1-4 carbon atoms, and a
formaldehyde scavenger like melamine, guanamine, benzyl guanamine,
guanidine, dicyandiamide, and the like.
[0007] U.S. Pat. No. 5,719,228 teaches using furan resins to bond
glass fibers together to manufacture glass fiber products and to
add urea or ammonia as formaldehyde scavengers, but also teach that
these known additives produce disadvantages and therefore prefer to
prereact an acidic furan resin, a formaldehyde scavenger and a
source of reactable formaldehyde with a source of ammonia before
spraying the binder onto the glass fibers.
[0008] U.S. Pat. No. 5,795,933 teaches aqueous metal coating
compositions comprising a formaldehyde containing resin and a
formaldehyde scavenger consisting essentially of an organic
compound having at least one active methylene hydrogen and a pKa
about 5 to 13.
[0009] U.S. Pat. No. 5,143,954 teaches a low formaldehyde,
self-cross linking polymer latex composition for use in making
nonwoven products, the composition including one or more very
complex and costly formaldehyde scavengers such as
N-hydroxyethylethyleneurea, ethyl acetoacetate, 2,4-pentanedione,
esters of 2-cyanoacetate, 2-cyanoacetamide, trimethylopropane
tricyanoacetate, and the polymerized residue of
methacryloxyethyleneurea.
[0010] As the above patents indicate, a tremendous effort has been
made to suppress the emissions of formaldehyde from various
products containing formaldehyde containing resins as a binder, but
as yet no effective solution has been known for achieving a
formaldehyde resin bound spunbonded web having low formaldehyde
emissions during the drying and curing operation of manufacturing
the Spunbond web or when contacted with hot asphalt in the
manufacture of roofing and similar products. This is the problem
solved by the invention described below.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention also includes a nonwoven web of
polymer fibers bonded with from about 5 to about 30 wt. percent of
a cured binder composition, preferably from about 16 to about 24
wt. percent and most preferably from about 18 to about 22 wt.
percent, based on the weight of the web or mat. The resin component
of the binder is of a type that will emit formaldehyde when exposed
to the high temperatures of drying and curing or to hot asphalt
conditions, such as resins having reasonably good elasticity such
as formaldehyde fortified, styrene-butadiene- acrylonitrile,
acrylic and similar type resins. The binder is preferably a mixture
of copolymers, like GenCryl.RTM. 9030 available from Omnova
Solutions, Inc. of Chester, S.C. By fortified is meant that
formaldehyde is incorporated into the polymer to provide high
temperature strength. The binder can also contain trace amounts of
free acrylamide, acrylonitrile, butadiene, formaldehyde, methanol,
styrene and 4-vinylcyclohexene. The basis weight of the web can be
any conventional weight but normally is in the range of about 50 to
about 250 gms/sq. meter, more typically about 100-225 and
preferably about 150-200, such as about 175 gms/sq. meter. The
latex may be a polymer composed of ethylene-vinyl acetate
copolymer, styrene-acrylic copolymer, vinyl-acrylic copolymer,
styrene-butadiene-acrylonitrile copolymer, or acrylic
copolymer.
[0012] The web is a spunbonded web of polymer, such as polyester,
fibers bound together with a resinous binder except that in place
of prior art binders, the binder contains one or more formaldehyde
fortified polymer resins that normally emit substantial
formaldehyde at high temperatures, but in this invention the binder
also contains a bisulfite compound, preferably ammonium bisulfite,
added in amounts from at least about 0.75 wt. percent up to about
7.5 wt. percent (dry weight basis of the binder). This binder is
applied in latex form to the fibrous web after the fibers are made
and collected in a known manner and then the wet web is dried and
heated to cure the binder in a known manner. The resultant nonwoven
webs have good hot strength and low formaldehyde emissions and
reasonable costs, something not heretofore attainable with these
types of formaldehyde containing latex binders. The webs of the
present invention are useful as substrates in known processes for
making various roofing products such as built up roofing products
and for other known uses in which polymer fiber webs are used.
[0013] The method of making the inventive webs is also part of the
present invention. This method comprises melting a polymer,
converting the melt to fibers, attenuating the fibers to the
desired fiber diameter, collecting the fibers in a random pattern
on a collecting surface, applying a formaldehyde containing latex
resin binder to the web in an amount that the binder content of the
dry web will be in the range of about 5-30 wt. percent, based on
the weight of the dry web, and drying the web and curing the resin
binder to bond the polymer fibers together to form a nonwoven
polymer fiber web, the improvement comprising adding about 0.75-7.5
wt. percent, based on the dry weight of the formaldehyde containing
resin, of a bisulfite compound to the latex binder before applying
the latex binder to the collected polymer fibers.
[0014] The above inventive binder composition produces webs that
reduce formaldehyde emissions by more than 25 percent, preferably
at least 50 percent and most preferably about 90 percent, compared
to a prior art web bound with the same resin, but not containing
the bisulfite addition, when the webs are heated to 200 degrees
Centigrade., a temperature expected in the drying and curing
operation of manufacturing the web or when subjected to hot
asphalt. This reduction of formaldehyde allows the use of preferred
binding resins that contain formaldehyde while avoiding the need
for costly investment in thermal or catalytic incinerators or other
emission abatement equipment and their operation in both the web
manufacturing plant and in the roofing plants where the webs are
used.
[0015] When the word "about" is used herein it is meant that the
amount or condition it modifies can vary some beyond that so long
as the advantages of the invention are realized. Practically, there
is rarely the time or resources available to very precisely
determine the limits of all the parameters of ones invention
because to do would require an effort far greater than can be
justified at the time the invention is being developed to a
commercial reality.
[0016] The skilled artisan understands this and expects that the
disclosed results of the invention might extend, at least somewhat,
beyond one or more of the limits disclosed. Later, having the
benefit of the inventors disclosure and understanding the inventive
concept and embodiments disclosed including the best mode known to
the inventor, the inventor and others can, without inventive
effort, explore beyond the limits disclosed to determine if the
invention is realized beyond those limits and, when embodiments are
found to be without any unexpected characteristics, those
embodiments are within the meaning of the term about as used
herein. It is not difficult for the artisan or others to determine
whether such an embodiment is either as expected or, because of
either a break in the continuity of results or one or more features
that are significantly better than reported by the inventor, is
surprising and thus an unobvious teaching leading to a further
advance in the art.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] The polymer fiber webs of the present invention can be
formed by many known processes for making polymer fiber webs, but a
typical preferred process is disclosed in U.S. Pat. No. 4,163,305,
which reference is incorporated herein by reference. After the
fibers, which can be any known polymer fiber, but are preferably
polyester fibers, are collected in a nonwoven form on a collection
surface such as a permeable conveyor belt or chain, the web is
passed through a binder applicator section where an aqueous latex
binder is applied in any conventional manner in the amount desired.
The wet, bindered web is then passed through a hot oven to dry the
web and to cure the resinous latex binder.
[0018] The binders used to make the webs of the present invention
are water-based latexes containing one or more polymer resins and a
bisulfite, preferably ammonium bisulfite. The bisulfite is present
in amounts from about 0.75 wt. percent to about 7.5 wt. percent,
based on the dry weight of the resin. Typically the bisulfite is
added in an aqueous solution in a concentration of about 60 wt.
percent, but it can be added in other well known forms so long as
it dissolves in the binder latex.
[0019] The resin used is a resin that is a latex polymer composed
of ethylene-vinyl acetate copolymer, styrene-acrylic copolymer,
vinyl-acrylic copolymer, styrene-butadiene-acrylonitrile copolymer,
or acrylic copolymer. The various copolymers may be prepared by
emulsion polymerization of one or more acrylic ester monomers
including ethyl acrylate, methyl acrylate, methyl methacrylate,
butyl acrylate, 2-ethyl hexylacrylate, hydroxyethyl acrylate,
hydroxypropyl acrylate, and hydroxyethyl methacrylate; acrylamide
or substituted acrylamides; butadiene; styrene ; acrylonitrile;
vinyl acetate or other vinyl esters; carboxylic acid monomers or
ethylenically unsaturated anhydrides which can generate carboxylic
acids. The latex polymer will have an internal N-methylol
crosslinker such as of N-methylol acrylamide, N-methylol
methacrylamide, or added resins that contain N-methylol functional
groups that are either chemically blocked or unblocked.
[0020] These types of resin all emit significant amounts of
formaldehyde when heated to high temperatures, such as the
conditions in the drying and curing operation of manufacturing the
webs or when contacted with hot, molten asphalt in typical roll
roofing (Built-Up-Roofing products) manufacturing processes. These
resins are typically fortified SBR, acrylic and resins having
similar properties as these resins. A preferred resin is known as
G-9030 available from Omnova Solutions, Inc. of Chester, S.C. This
material is a styrene-butadiene-acrylonitrile type latex having the
following characteristics:
[0021] Active solids concentration in water 50%
[0022] Ph--about 7.5
[0023] Specific Gravity--1.08
[0024] Volatile organic content (VOC) <0.1%
[0025] Any type of polymer fibers can be used in the webs of the
present invention depending upon the desired properties of the webs
and the intended applications as is well known to the artisan. When
making webs for use in making roofing products spunbond polyester
fibers are preferred. The following examples demonstrate the
problems solved by the present invention, some of the preferred
embodiments and the most preferred embodiment, and demonstrate only
a few of the many possible embodiments of the present
invention.
EXAMPLE 1
[0026] A polyester spunbonded mat was made in a known manner such
as the process described in U.S. Pat. No. 4,125,663, the disclosure
hereby incorporated herein by reference, in which the binder used
to bond the polyester fibers together was GenCryl.RTM. 9000, an
emulsified styrene butadiene acrylonitrile copolymer latex binder
containing very little formaldehyde, available from Omnova
Solutions, Inc. of Chester, S.C. This binder did not contain a
bisulfite addition. The binder content was 20 wt. percent in the
finished dry mat, based on the weight of the dry mat. The
properties of this mat are shown in Table 1 below.
EXAMPLE 2
[0027] A second polyester spunbond mat was made in the same process
as the mat made in Example 1 above except the binder used was
GenCryl.RTM. 9030, the high performance mixed polymer latex type
binder with a 50 percent concentration in water and available from
Omnova Solutions, Inc. This binder is described above in detail.
The binder content in the mat made in this example was about 18 wt.
percent. By high performance binder is meant that the binder
contains N-methylol functionality and as such exhibits improved
high temperature performance characteristics when subjected to
temperatures of hot asphalt, 200 degrees centigrade. No addition of
bisulfite was made to this binder. The properties of this mat are
shown in Table 1 below.
EXAMPLE 3
[0028] Another web was made using the process used in Example 1
except that 2.5 wt. percent of ammonium bisulfite (60%
concentration in water), based on the dry weight of the binder, was
added to the high performance GenCryl.RTM. G-9030 binder containing
formaldehyde used in Example 2 above. These properties of this
finished mat are compared with the properties of the mats made in
Examples 1 and 2 in Table 1.
1TABLE 1 Properties Example 1 Example 2 Example 3 Binder Content
(wt. %) 20 18 18 Basis wt. (gms/sq. meter) 173 174 172 Thickness
(mm) 0.95 1.01 1.00 Tenmsile strength (lb./in.) Machine Direction
72 79 75 Cross Machine Dir. 46 44 42 Elongation Machine Direction
31 30 30 Cross Machine Dir. 33 34 33 Shrinkage @ 200 deg. C. (%)
Machine Direction 0.90 0.93 0.94 Cross Machine Dir. -0.30 -.20
-0.22 Tear Strength (lbs.) Machine Direction 32 32 31 Cross Machine
Dir. 23 23 23 TDS* @ 200 deg. C. (%) Machine Direction 1.5 1.0 1.0
Cross Machine Dir. -1.6 -1.2 -1.3 Tube Furnace Emissions 1400
16,333 4628 (ppm formaldehyde)** *Thermal Dimensional Stability
(Description of test given below). **binder heated to 200 deg. C.
and exhaust gas analyzed.
[0029] Thermal Dimensional Stability is a characteristic that is
very important in the use of nonwoven polymer fiber mats in the
manufacture of roofing products. As discussed above in the
background, polymer fiber mats tend to stretch in the machine
direction and neck down, shrink, in the cross machine direction
when coated or impregnated with hot, molten, asphalt or modified
asphalt material. This stretching and particularly the necking down
in the cross machine direction requires the use of a wider mat to
compensate and to insure the final dimension of the roofing
product. Wider mats are often much more costly because the machine
making the mats is limited in width and as much as 20-50%
productivity can be lost when making a wider mat.
[0030] The test for Thermal Dimensional Stability is as follows.
Three test samples measuring 350 mm in the machine direction of the
mat and 100 mm in the cross machine direction are cut from the mat
with a specimen being taken 100 mm from each side of the mat and
the third sample taken from the center portion of the mat. A line
is drawn across one surface of each of the samples 50 mm on each
side of and parallel to the lengthwise centerline of the sample
using a material that will still be visible after heating to 200
degrees C. Each sample is mounted on a stand with a preheated clamp
that allows each sample to hang vertically in a furnace with a four
kg weight attached to the bottom clamp on the sample to provide
stress on the sample similar to the stress on the mat in the
roofing product manufacturing process. Clamps attaching to each
sample are preheated for five minutes at 200 degrees Centigrade in
the oven, removed and attached to the samples and placed back into
the 200 degree oven for five minutes, then removed and allowed to
cool under stress for five minutes. The distance between the marks
made on each sample is measured as is the width of the sample at
the lengthwise centerline and the amount of change calculated. The
three machine direction results are averaged to give the machine
direction percent change and the three width or cross machine
direction results are averaged to give the cross machine direction
percent change. Values of 1.0% or less are highly desirable.
[0031] The nonwoven web or mat of Example 1 has been used to make
roofing products. It has acceptable formaldehyde emissions in the
drying and curing section of the web manufacturing process or hot
asphalt coating operation, but it produces lower performance in hot
elongation in the roofing manufacturing process than desired as
indicated by the TDS results, i.e. more than desired stretching in
the machine direction and necking down in the cross machine
direction. The nonwoven mat of Example 2 had about 33% improvement
in the TDS test compared to that of Example 1, an acceptable hot
strength, but the formaldehyde emissions at elevated temperature
was unacceptably high.
[0032] The addition of a bisulfite is effective in lowering
formaldehyde emissions at elevated temperatures in amounts as low
as 0.75 wt. percent based on the dry weight of the formaldehyde
resin in the latex. Table 2 shows the effect of ammonium bisulfite
concentration in the G-9030 latex binder in webs made using the
method of Example 3, but varying the amount of ammonium bisulfite
addition to the binder before applying the binder latex to the
polyester web.
2 TABLE 2 Amount of Bisulfite Compound Added Tube Furnace Results:
0% 0.75% 1.25% 2.5% 5% Emissions (ppm 16,333 12,000 8085 4630 1265
CH20)
[0033] The bisulfite compound is useful up to about 7.5 wt. percent
to reduce emissions, but above about 7.5 percent the bisulfite
begins to degrade the properties of the webs. While ammonium
bisulfite is the preferred additive, the bisulfite can be any
bisulfite material such as sodium bisulfite, calcium bisulfite,
etc.
[0034] The preferred embodiments described above are only a few of
the many embodiments possible as will be readily recognized by a
person of ordinary skill in this art given the above disclosure.
These and obvious modifications thereof are intended to be included
in the following claims.
* * * * *