U.S. patent application number 10/282076 was filed with the patent office on 2004-04-29 for imidazoline containing fiberglass binder.
Invention is credited to Miele, Philip Francis, Taylor, Thomas J., Wang, Lance.
Application Number | 20040082689 10/282076 |
Document ID | / |
Family ID | 32107297 |
Filed Date | 2004-04-29 |
United States Patent
Application |
20040082689 |
Kind Code |
A1 |
Taylor, Thomas J. ; et
al. |
April 29, 2004 |
IMIDAZOLINE CONTAINING FIBERGLASS BINDER
Abstract
Provided is a fiberglass binder composition which comprises a
polycarboxy polymer, polyol and an imidazoline. The binder also
preferably includes a catalyst which is an alkali metal salt of a
phosphorus-containing organic acid. The resultant binder provides
minimal processing difficulties and a product which exhibits
minimal water absorption.
Inventors: |
Taylor, Thomas J.; (Aurora,
CO) ; Miele, Philip Francis; (Highlands Ranch,
CO) ; Wang, Lance; (Parker, CO) |
Correspondence
Address: |
Robert D. Touslee
Johns Manville
10100 West Ute Avenue
Littleton
CO
80127
US
|
Family ID: |
32107297 |
Appl. No.: |
10/282076 |
Filed: |
October 28, 2002 |
Current U.S.
Class: |
524/106 ;
524/494 |
Current CPC
Class: |
C08K 5/3445 20130101;
C03C 25/323 20130101; Y10T 428/249924 20150401; Y10T 428/252
20150115; Y10T 428/249928 20150401; Y10T 428/249921 20150401 |
Class at
Publication: |
524/106 ;
524/494 |
International
Class: |
C08K 005/34; C08K
003/40 |
Claims
What is claimed is:
1. A fiberglass binder, comprising an aqueous solution of a
polycarboxy polymer, a polyol and an imidazoline.
2. The fiberglass binder of claim 1, wherein the imidazoline is
based upon the reaction of a fatty acid with an amine.
3. The fiberglass binder of claim 2, wherein the fatty acid is
comprised of stearic acid, oleic acid or tall oil.
4. The fiberglass binder of claim 2, wherein the amine is comprised
of an aminoethylethanolamine.
5. The fiberglass binder of claim 2, wherein the amine is comprised
of diethylene triamine.
6. The fiberglass binder of claim 2, wherein the imidazoline
comprises oleyl hydroxyethyl imidazoline.
7. The fiberglass binder of claim 1, wherein the imidazoline
comprises from about 0.4 to 3.0 wt % of the binder.
8. The fiberglass binder of claim 1, wherein the imidazoline
comprises from about 0.6 to 2.6 wt % of the binder.
9. The fiberglass binder of claim 1, wherein the imidazoline
comprises from about 1.2 to 2.4 wt % of the binder.
10. The fiberglass binder of claim 4, wherein the fatty acid is
comprised of stearic acid, oleic acid or tall oil.
11. The fiberglass binder of claim 5, wherein the fatty acid is
comprised of stearic acid, oleic acid or tall oil.
12. The fiberglass binder of claim 1, wherein the molecular weight
of the polycarboxy polymer is less than 5000.
13. The fiberglass binder of claim 1, wherein the molecular weight
of the polycarboxy polymer is less than 3000.
14. The fiberglass binder of claim 1, wherein the binder further
comprises a catalyst which comprises an alkali metal salt of a
phosphorus-containing organic acid.
15. The fiberglass binder of claim 14, wherein the catalyst is
sodium hydophosphite, sodium phosphite, or a mixture thereof.
16. The fiberglass binder of claim 1, wherein the polyol is
triethanolamine.
17. The fiberglass binder of claim 1, wherein the polycarboxy
polymer comprises homopolymers and/or copolymers of polyacrylic
acid.
18. The fiberglass binder of claim 1, wherein the amount of
polycarboxy polymer and polyol in the binder is such that the ratio
of carboxy group equivalents to hydroxyl group equivalents is in
the range of from about 1/0.65 to 1/0.75.
19. A fiberglass binder, comprising an aqueous solution of a
homopolymer and/or copolymer of polyacrylic acid, where the
polyacrylic acid polymer has a molecular weight of 5000 or less,
triethanolamine, and an imidazoline.
20. The fiberglass binder of claim 19, wherein the binder further
contains a catalyst which comprises an alkali metal salt of a
phosphorus-containing organic acid.
21. The fiberglass binder of claim 19, wherein the amount of
polyacrylic acid polymer and triethanolamine in the binder is such
that the ratio of carboxy group equivalents to hydroxyl group
equivalents is in the range of from about 1/0.65 to 1/0.75.
22. The fiberglass binder of claim 19, wherein the imidazoline is
based upon the reaction of a fatty acid with an amine.
23. The fiberglass binder of claim 22, wherein the fatty acid is
comprised of stearic acid, oleic acid or tall oil.
24. The fiberglass binder of claim 22, wherein the amine is
comprised of an aminoethylethanolamine.
25. The fiberglass binder of claim 22, wherein the amine is
comprised of diethylene triamine.
26. The fiberglass binder of claim 19, wherein the imidazoline
comprises oleyl hydroxyethyl imidazoline.
27. The fiberglass binder of claim 19, wherein the imidazoline
comprises from about 0.4 to 3.0 wt % of the binder.
28. The fiberglass binder of claim 19, wherein the imidazoline
comprises from about 0.6 to 2.6 wt % of the binder.
29. The fiberglass binder of claim 19, wherein the imidazoline
comprises from about 1.2 to 2.4 wt % of the binder.
30. A fiberglass product comprising a mat of glass fibers
containing the binder of claim 1.
31. The fiberglass product of claim 30, wherein the product is
building insulation.
32. The fiberglass product of claim 30, wherein the product is
reinforcing mat for roofing or flooring.
33. The fiberglass product of claim 30, wherein the product is a
microglass-based substrate useful for printed circuit boards or
battery separators, filter stock, tape stock or reinforcement
scrim.
34. The fiberglass product of claim 30, wherein the product is
filter stock.
35. The fiberglass product of claim 30, wherein the imidazoline is
comprised of oleyl hydroxyethyl imidazoline.
36. The fiberglass product of claim 30, wherein the amount of
imidazoline contained therein ranges from about 0.02 to 0.15 wt
%.
37. The fiberglass product of claim 30, wherein the amount of
imidazoline contained therein ranges from about 0.03 to 0.13 wt
%.
38. The fiberglass product of claim 30, wherein the amount of
imidazoline contained therein ranges from about 0.06 to 0.12 wt %.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The subject invention pertains to polycarboxy polymer
binding resins having improved water absorption properties. More
particularly, the subject invention pertains to thermosetting,
acrylic acid-based binder resins which cure by crosslinking with a
poly-functional, carboxyl group-reactive curing agent, which
binders containing such resins exhibit minimal water absorption.
Such binders are useful as replacements for formaldehyde-based
binders in non-woven fiberglass goods.
[0003] 2. Description of the Related Art
[0004] Fiberglass binders have a variety of uses ranging from
stiffening applications where the binder is applied to woven or
non-woven fiberglass sheet goods and cured, producing a stiffer
product; thermo-forming applications wherein the binder resin is
applied to sheet or lofty fibrous product following which it is
dried and optionally B-staged to form an intermediate but yet
curable product; and to fully cured systems such as building
insulation.
[0005] Fibrous glass insulation products generally comprise matted
glass fibers bonded together by a cured thermoset polymeric
material. Molten streams of glass are drawn into fibers of random
lengths and blown into a forming chamber where they are randomly
deposited as a mat onto a traveling conveyor. The fibers, while in
transit in the forming chamber and while still hot from the drawing
operation, are sprayed with an aqueous binder. A
phenol-formaldehyde binder has been used throughout the fibrous
glass insulation industry. The residual heat from the glass fibers
and the flow of air through the fibrous mat during the forming
operation are generally sufficient to volatilize the majority of
the water from the binder, thereby leaving the remaining components
of the binder on the fibers as a viscous or semi-viscous high
solids liquid. The coated fibrous mat is transferred to a curing
oven where heated air, for example, is blown through the mat to
cure the binder and rigidly bond the glass fibers together.
[0006] Fiberglass binders used in the present sense should not be
confused with matrix resins which are an entirely different and
non-analogous field of art. While sometimes termed "binders",
matrix resins act to fill the entire interstitial space between
fibers, resulting in a dense, fiber reinforced product where the
matrix must translate the fiber strength properties to the
composite, whereas "binder resins" as used herein are not
space-filling, but rather coat only the fibers, and particularly
the junctions of fibers. Fiberglass binders also cannot be equated
with paper or wood product "binders" where the adhesive properties
are tailored to the chemical nature of the cellulosic substrates.
Many such resins, e.g. urea/formaldehyde and
resorcinol/formaldehyde resins, are not suitable for use as
fiberglass binders. One skilled in the art of fiberglass binders
would not look to cellulosic binders to solve any of the known
problems associated with fiberglass binders.
[0007] Binders useful in fiberglass insulation products generally
require a low viscosity in the uncured state, yet characteristics
sufficient to form a rigid thermoset polymeric mat for the glass
fibers when cured. A low binder viscosity in the uncured state is
required to allow the mat to be sized correctly. Also, viscous
binders tend to be tacky or sticky and hence they lead to
accumulation of fiber on the forming chamber walls. This
accumulated fiber may later fall onto the mat causing dense areas
and product problems. A binder which forms a rigid solid when cured
is required so that a finished fiberglass thermal insulation
product, when compressed for packaging and shipping, will recover
to its as-made vertical dimension when installed in a building.
[0008] From among the many thermosetting polymers, numerous
candidates for suitable thermosetting fiber-glass binder resins
exist. However, binder-coated fiberglass products are often of the
commodity type, and thus cost becomes a driving factor, generally
ruling out such resins as thermosetting polyurethanes, epoxies, and
others. Due to their excellent cost/performance ratio, the resins
of choice in the past have been phenol/formaldehyde resins.
Phenol/formaldehyde resins can be economically produced, and can be
extended with urea prior to use as a binder in many applications.
Such urea-extended phenol/formaldehyde binders have been the
mainstay of the fiberglass insulation industry for years, for
example.
[0009] Over the past several decades however, minimization of
volatile organic compound emissions (VOCS) both on the part of the
industry desiring to provide a cleaner environment, as well as by
Federal regulation, has led to extensive investigations into not
only reducing emissions from the current formaldehyde-based
binders, but also into candidate replacement binders. For example,
subtle changes in the ratios of phenol to formaldehyde in the
preparation of the basic phenol/formaldehyde resole resins, changes
in catalysts, and addition of different and multiple formaldehyde
scavengers, has resulted in considerable improvement in emissions
from phenol/formaldehyde binders as compared with the binders
previously used. However, with increasingly stringent Federal
regulations, more and more attention has been paid to alternative
binder systems which are free from formaldehyde.
[0010] One such candidate binder system employs polymers of acrylic
acid as a first component, and a polyol such as glycerin or a
modestly oxyalkylated glycerin as a curing or "crosslinking"
component. The preparation and properties of such poly(acrylic
acid)-based binders, including information relative to the VOC
emissions, and a comparison of binder properties versus urea
formaldehyde binders is presented in "Formaldehyde-Free
Crosslinking Binders For NonWovens", Charles T. Arkins et al.,
TAPPI JOURNAL, Vol. 78, No. 11, pages 161-168, November 1995. The
binders disclosed by the Arkins article, appear to be B-stageable
as well as being able to provide physical properties similar to
those of urea/formaldehyde resins.
[0011] U.S. Pat. No. 5,340,868 discloses fiberglass insulation
products cured with a combination of a polycarboxy polymer, a
-hydroxyalkylamide, and an at least one trifunctional monomeric
carboxylic acid such as citric acid. The specific polycarboxy
polymers disclosed are poly(acrylic acid) polymers. See also, U.S.
Pat. No. 5,143,582
[0012] U.S. Pat. No. 5,318,990 discloses a fibrous glass binder
which comprises a polycarboxy polymer, a monomeric trihydric
alcohol and a catalyst comprising an alkali metal salt of a
phosphorous-containing organic acid.
[0013] Published European Patent Application EP 0 583 086 A1
appears to provide details of polyacrylic acid binders whose cure
is catalyzed by a phosphorus-containing catalyst system as
discussed in the Arkins article previously cited. Higher molecular
weight poly(acrylic acids) are stated to provide polymers
exhibiting more complete cure. See also U.S. Pat. Nos. 5,661,213;
5,427,587; 6,136,916; and 6,221,973.
[0014] Some polycarboxy polymers have been found useful for making
fiberglass insulation products. Problems of clumping or sticking of
the glass fibers to the inside of the forming chambers during the
processing, as well as providing a final product that exhibits the
recovery and rigidity necessary to provide a commercially
acceptable fiberglass insulation product, have been overcome. See,
for example, U.S. Pat. No. 6,331,350. The thermosetting acrylic
resins have been found to be more hydrophilic than the traditional
phenolic binders, however. This hydrophilicity results in
fiberglass insulation that is more prone to absorb liquid water,
thereby possibly compromising the integrity of the product. Also,
the thermosetting acrylic resins now being used as binding agents
for fiberglass have been found to not react as effectively with
silane coupling agents of the type traditionally used by the
industry. Overcoming these problems will help to better utilize
polycarboxy polymers in fiberglass binders.
[0015] Accordingly, it is an objective of the present invention to
provide a novel, non-phenol formaldehyde binder.
[0016] Yet another object of the present invention is to provide
such a binder which allows one to prepare fiberglass insulation
products which are less prone to absorb liquid water.
[0017] Still another object of the present invention is to provide
a fiberglass insulation product which exhibits good recovery and
rigidity, and is formaldehyde-free, and is more water-proof.
[0018] These and other objects of the present invention will become
apparent to the skilled artisan upon a review of the following
description and the claims appended hereto.
SUMMARY OF THE INVENTION
[0019] In accordance with the foregoing objectives, there is
provided by the present invention a novel fiberglass binder. The
binder composition of the present invention comprises a polycarboxy
polymer, a polyol and an imidazoline. It is also preferred that the
binder comprise a catalyst, such as an alkaline metal salt of a
phosphorus-containing organic acid.
[0020] An important aspect of the binder of the present invention
is that the imidazoline material is present. The presence of the
imidazoline has been found to render the binder, and hence the
fiberglass mat to which the binder is applied, essentially
water-proof. As a result, fiberglass insulation made with the
binder of the present invention avoids problems of coming apart
when subjected to water, as the binder of the present invention has
been found to better repel the water and maintain the integrity of
the bond with the fiberglass. Indeed, it is believed that the
imidazoline materials used, primarily due to their hydroxy
functionality, act as coupling agents for resin to glass
adhesion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The polycarboxy polymer used in the binder of the present
invention comprises an organic polymer or oligomer containing more
than one pendant carboxy group. The polycarboxy polymer may be a
homopolymer or copolymer prepared from unsaturated carboxylic acids
including but not necessarily limited to acrylic acid, methacrylic
acid, crotonic acid, isocrotonic acid, maleic acid, cinnamic acid,
2-methylmaleic acid, itaconic acid, 2-methylitaeonic acid, alpha,
beta-methyleneglutaric acid, and the like. Alternative, the
polycarboxy polymer may be prepared from unsaturated anhydrides
including, but not necessarily limited to, maleic anhydride,
methacrylic anhydride, and the like, as well as mixtures thereof.
Methods for polymerizing these acids and anhydrides are well-known
in the chemical art.
[0022] The polycarboxy polymer of the present invention may
additionally comprise a copolymer of one or more of the
aforementioned unsaturated carboxylic acids or anhydrides and one
or more vinyl compounds including, but not necessarily limited to,
styrene, alpha-methylstyrene, aorylonitrile, methacrylonitrile,
methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl
acrylate, methyl methacrylate, n-butyl methacrylate, isobutyl
methacrylate, blycidyl methacrylate, vinyl methyl ether, vinyl
acetate, and the like. Methods for preparing these copolymers are
well-known in the art.
[0023] Preferred polycarboxy polymers comprise homopolymers and
copolymers of polyacrylic acid. It is particularly preferred that
the molecular weight of the polycarboxy polymer, and in particular
polyacrylic acid polymer, is less than 10000, more preferably less
than 5000, and most preferably about 3000 or less. The low
molecular weight polycarboxy polymer, when combined with a low pH
binder, results in a final product which exhibits excellent
recovery and rigidity.
[0024] The formaldehyde-free curable aqueous binder composition of
the present invention also contains a polyol containing at least
two hydroxyl groups. The polyol must be sufficiently nonvolatile
such that it will substantially remain available for reaction with
the polyacid in the composition during heating and curing
operations. The polyol may be a compound with a molecular weight
less than about 1000 bearing at least two hydroxyl groups such as,
for example, ethylene glycol, glycerol, pentaerythritol,
trimethylol propane, sorbitol, sucrose, glucose, resorcinol,
catechol, pyrogallol, glycollated ureas, 1,4-cyclohexane diol,
diethanolamine, triethanolamine, and certain reactive polyols such
as, for example, -hydroxyalkylamides such as, for example,
bis[N,N-di(beta-hydroxyethyl)]adipamide, as may be prepared
according to the teachings of U.S. Pat. No. 4,076,917, hereby
incorporated herein by reference, or it may be an addition polymer
containing at least two hydroxyl groups such as, for example,
polyvinyl alcohol, partially hydrolyzed polyvinyl acetate, and
homopolymers or copolymers of hydroxyethyl (meth) acrylate,
hydroxypropyl(meth) acrylate, and the like. The most preferred
polyol for the purposes of the present invention is triethanolamine
(TEA).
[0025] The ratio of the number of equivalents of carboxy,
anhydride, or salts thereof of the polyacid to the number of
equivalents of hydroxyl in the polyol is from about 1/0.01 to about
1/3. An excess of equivalents of carboxy, anhydride, or salts
thereof of the polyacid to the equivalents of hydroxyl in the
polyol is preferred. The more preferred ratio of the number of
equivalents of carboxy, anhydride, or salts thereof in the polyacid
to the number of equivalents of hydroxyl in the polyol is from
about 1/0.4 to about 1/1. The most preferred ratio of the number of
equivalents of carboxy, anhydride, or salts thereof in the polyacid
to the number of equivalents of hydroxyl in the polyol is from
about 1/0.2 to about 1/0.95, more preferably from 1/0.6 to 1/0.8,
and most preferably from 1/0.65 to 1/0.75. A low ratio, approaching
1/0.7 has been found to be of particular advantage in the present
invention, when combined with a low molecular weight polycarboxy
polymer, and also preferably with a low pH binder.
[0026] The binder of the present invention also contains an
imidazoline material. The presence of the imidazoline has been
found to render the binder less prone to absorb water. As a result,
the integrity of the bond between the binder and glass fiber, and
hence the integrity of the entire mat product, is better maintained
when exposed to liquid water. The binder bond, and hence the
overall product, is more water-proof.
[0027] The imidazoline of the present invention is preferably based
upon the reaction of a fatty acid with an amine. The reaction forms
an amide which then undergoes cyclization at elevated temperatures
to form the imidazoline.
[0028] Preferably, the entire reaction product is used as the
additive to the binder composition. The reaction product is a
mixture of the reactants, intermediates, and final product.
[0029] The fatty acid can be any fatty acid, but is preferably
selected from stearic acid, oleic acid or tall oil. The amine can
also be any suitable amine, but is preferably comprised of an
aminoethylethanolamine. Amines such as diethylene triamine can also
be used. From a performance standpoint, oleyl hydroxyethyl
imidazoline is the most preferred imidazoline for use in the binder
of the present invention.
[0030] It is also most preferred that the imidazoline be hydroxy
functional as it acts as a coupling agent for resin to glass
adhesion. Since acrylic resins do not react very effectively with
silane coupling agents, this is an additional advantage of the
present invention.
[0031] It is preferred that the formaldehyde-free curable aqueous
binder composition of the present invention also contains a
catalyst. Most preferably, the catalyst is a phosphorous-containing
accelerator which may be a compound with a molecular weight less
than about 1000 such as, for example, an alkali metal
polyphosphate, an alkali metal dihydrogen phosphate, a
polyphosphoric acid, and an alkyl phosphinic acid or it may be an
oligomer or polymer bearing phosphorous-containing groups such as,
for example, addition polymers of acrylic and/or maleic acids
formed in the presence of sodium hypophosphite, addition polymers
prepared from ethylenically unsaturated monomers in the presence of
phosphorous salt chain transfer agents or terminators, and addition
polymers containing acid-functional monomer residues such as, for
example, copolymerized phosphoethyl methacrylate, and like
phosphonic acid esters, and copolymerized vinyl sulfonic acid
monomers, and their salts. The phosphorous-containing accelerator
may be used at a level of from about 1% to about 40%, by weight
based on the combined weight of the polyacid and the polyol.
Preferred is a level of phosphorous-containing accelerator of from
about 2.5% to about 10%, by weight based on the combined weight of
the polyacid and the polyol.
[0032] It is most preferred that the pH of the binder of the
present invention also be low, i.e., no greater than 4.5. For it
has been found that the combination of low molecular weight
polycarboxy polymer with a lowered pH provides a binder exhibiting
minimal processing difficulties and a final product with excellent
recovery and rigidity. Maintaining the pH in the range of greater
than 3.5 to 4.5 or less, also allows one to avoid serious problems
with conversion of the equipment while still realizing the benefits
of the low pH.
[0033] The formaldehyde-free curable aqueous binder composition may
contain, in addition, conventional treatment components such as,
for example, emulsifiers, pigments, filler, anti-migration aids,
curing agents, coalescents, wetting agents, biocides, plasticizers,
organosilanes, anti-foaming agents, colorants, waxes, and
anti-oxidants.
[0034] The formaldehyde-free curable aqueous binder composition may
be prepared by admixing the polyacid, the polyol, and the
phosphorous-containing accelerator using conventional mixing
techniques. In another embodiment, a carboxyl- or
anhydride-containing addition polymer and a polyol may be present
in the same addition polymer, which addition polymer would contain
both carboxyl, anhydride, or salts thereof functionality and
hydroxyl functionality. In another embodiment, the salts of the
carboxy-group are salts of functional alkanolamines with at least
two hydroxyl groups such as, for example, diethanolamine,
triethanolamine, dipropanolamine, and di-isopropanolamine. In an
additional embodiment, the polyol and the phosphorous-containing
accelerator may be present in the same addition polymer, which
addition polymer may be mixed with a polyacid. In yet another
embodiment the carboxyl- or anhydride-containing addition polymer,
the polyol, and the phosphorous-containing accelerator may be
present in the same addition polymer. Other embodiments will be
apparent to one skilled in the art. As disclosed herein-above, the
carboxyl groups of the polyacid may be neutralized to an extent of
less than about 35% with a fixed base before, during, or after the
mixing to provide the aqueous composition. Neutralization may be
partially effected during the formation of the polyacid.
[0035] Once the composition of the polyacid and the polyol has been
prepared, the imidazoline can then be mixed in with the composition
to form the final composition to be sprayed on the fiberglass. The
imidazoline is therefore basically an important additive to
conventional binder systems, such as that described in U.S. Pat.
No. 6,331,350, which is hereby expressly incorporated by reference
in its entirety. As molten streams of glass are drawn into fibers
of random lengths and blown into a forming chamber where they are
randomly deposited as a mat onto a traveling conveyor, the fibers,
while in transit in the forming chamber, are sprayed with the
aqueous binder composition of the present invention, which includes
the imidazoline.
[0036] More particularly, in the preparation of fiberglass
insulation products, the products can be prepared using
conventional techniques. As is well known, a porous mat of fibrous
glass can be produced by fiberizing molten glass and immediately
forming a fibrous glass mat on a moving conveyor. The expanded mat
is then conveyed to and through a curing oven wherein heated air is
passed through the mat to cure the resin. The mat is slightly
compressed to give the finished product a predetermined thickness
and surface finish. Typically, the curing oven is operated at a
temperature from about 150.degree. C. to about 325.degree. C.
Preferably, the temperature ranges from about 180 to about
225.degree. C. Generally, the mat resides within the oven for a
period of time from about 1/2 minute to about 3 minutes. For the
manufacture of conventional thermal or acoustical insulation
products, the time ranges from about 3/4 minute to about 11/2
minutes. The fibrous glass having a cured, rigid binder matrix
emerges from the oven in the form of a bat which may be compressed
for packaging and shipping and which will thereafter substantially
recover its vertical dimension when unconstrained.
[0037] The formaldehyde-free curable aqueous composition may also
be applied to a already formed nonwoven by conventional techniques
such as, for example, air or airless spraying, padding, saturating,
roll coating, curtain coating, beater deposition, coagulation, or
the like.
[0038] The waterborne formaldehyde-free composition, after it is
applied to a nonwoven, is heated to effect drying and curing. The
duration and temperature of heating will affect the rate of drying,
processability and handleability, and property development of the
treated substrate. Heat treatment at about 120.degree. C., to about
400.degree. C., for a period of time between about 3 seconds to
about 15 minutes may be carried out; treatment at about 150.degree.
C., to about 250.degree. C., is preferred. The drying and curing
functions may be effected in two or more distinct steps, if
desired. For example, the composition may be first heated at a
temperature and for a time sufficient to substantially dry but not
to substantially cure the composition and then heated for a second
time at a higher temperature and/or for a longer period of time to
effect curing. Such a procedure, referred to as "B-staging", may be
used to provide binder-treated nonwoven, for example, in roll form,
which may at a later stage be cured, with or without forming or
molding into a particular configuration, concurrent with the curing
process.
[0039] The heat-resistant nonwovens may be used for applications
such as, for example, insulation batts or rolls, as reinforcing mat
for roofing or flooring applications, as roving, as
microglass-based substrate for printed circuit boards or battery
separators, as filter stock, as tape stock, as tape board for
office petitions, in duct liners or duct board, and as
reinforcement scrim in cementitious and non-cementitious coatings
for masonry.
[0040] The following examples are produced in order to further
illustrate the present invention, and are not intended to limit the
invention.
EXAMPLE
[0041] The following materials were used in a trial to evaluate a
range of imidazoline materials:
[0042] 1. 2-(2-heptadec-1-enyl-4,5-dihydroimidazol-1-yl)ethanol
also known as oleyl hydroxyethyl imidazoline. This was supplied by
Lonza as Unamine O. It is also available from Scher Chemicals as
Schercozolione O.
[0043] 2. Coco hydroxyethyl imidazoline supplied by Lonza as
Unamine C.
[0044] 3. Lubril Cat X/VC from Rhodia. This is believed to be based
on a poly(ethylene amine) and is described as a fatty amide.
[0045] 4. Indulin QTS from MeadWestvaco. This is described as a
fatty acid imidazoline.
[0046] 5. Peral 417 from MeadWestvaco. This is described as a fatty
acid imidazoline.
[0047] These materials were added to a standard thermosetting
acrylic binder comprising a polyacrylic acid and a polyol
(triethyenolamine). The resin was supplied to the fiberglass at a
rate such that the final product contained about 5% by weight of
the binder. The materials listed above were added in turn to
produce samples of product containing each of the additives. The
fiberglass was a R6 product with a thickness of 2 inches.
[0048] The samples were tested for water repellancy by two methods.
In the first method, a 6 inch.times.6 inch square of the fiberglass
was placed onto a bath of water for 5 minutes. After that time, the
fiberglass was removed and suspended for 30 seconds from one corner
to allow draining and then immediately weighed. The weight gain was
recorded as a percent of the original weight. In the second method,
a 6 inch.times.6 inch square of the fiberglass was placed onto a
bath of water. the time taken for the sample to completely immerse
was recorded. The results are shown below:
1 Time to Sink, Sample *Amount of Additive, % Weight Gain seconds
Control Before 0 1861% 210 1A 0.06 76% 1566 1B 0.11 28% 5700 2A
0.07 814% 247 2B 0.13 678% 640 3A 0.03 605% 610 3B 0.06 566% 425 4
0.12 809% 615 5 0.11 1638% 295 Control After 0 1803% 210 *The
amount of additive is solids expressed as a percent of total
product weight.
[0049] All of the imidazoline additives significantly reduced the
amount of water absorbed by the fiberglass. The oleyl hydroxyethyl
imidazoline was the best material and is most preferred.
[0050] While the invention has been described with preferred
embodiments, it is to be understood that variations and
modifications may be resorted to as will be apparent to those
skilled in the art. Such variations and modifications are to be
considered within the purview and the scope of the claims appended
hereto.
* * * * *