U.S. patent application number 11/083197 was filed with the patent office on 2005-09-01 for water repellant fiberglass binder.
This patent application is currently assigned to Johns Manville International, Inc.. Invention is credited to Miele, Philip Francis, Taylor, Thomas J., Wang, Lance.
Application Number | 20050191924 11/083197 |
Document ID | / |
Family ID | 32868261 |
Filed Date | 2005-09-01 |
United States Patent
Application |
20050191924 |
Kind Code |
A1 |
Taylor, Thomas J. ; et
al. |
September 1, 2005 |
Water repellant fiberglass binder
Abstract
Provided is a fiberglass binder composition which comprises a
polycarboxy polymer modified with a fatty acid, and a polyol. 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 fiberglass product
which exhibits minimal water absorption.
Inventors: |
Taylor, Thomas J.;
(Northville, MI) ; Miele, Philip Francis;
(Highlands Ranch, CO) ; Wang, Lance; (Parker,
CO) |
Correspondence
Address: |
JOHNS MANVILLE INTERNATIONAL, INC.
717 SEVENTEENTH STREET
DENVER
CO
80202
US
|
Assignee: |
Johns Manville International,
Inc.
|
Family ID: |
32868261 |
Appl. No.: |
11/083197 |
Filed: |
March 18, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11083197 |
Mar 18, 2005 |
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10370982 |
Feb 20, 2003 |
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6884838 |
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Current U.S.
Class: |
442/331 |
Current CPC
Class: |
Y10T 442/604 20150401;
H05K 1/0366 20130101; C09J 133/04 20130101 |
Class at
Publication: |
442/331 |
International
Class: |
D04H 013/00 |
Claims
1-24. (canceled)
25. A fiberglass binder having improved water absorption
properties, comprising an aqueous solution of a modified
polycarboxy polymer and a polyol.
26. The fiberglass binder of claim 25, wherein the molecular weight
of the polycarboxy polymer is less than 5000.
27. The fiberglass binder of claim 25, wherein the molecular weight
of the polycarboxy polymer is less than 3000.
28. The fiberglass binder of claim 25, wherein the binder further
comprises a catalyst which comprises an alkali metal salt of a
phophorus containing organic acid.
29. The fiberglass binder of claim 25, wherein the polyol is
triethanolamine.
30. The fiberglass binder of claim 25, wherein the amount of
polycarboxy polymer and polyol in the binder is such that the ratio
of carboxy groups equivalent to hydroxyl groups equivalents is in
the range of from about 1/0.65 to 1/0.75.
31. A fiberglass product comprising a mat of glass fibers
containing the binder of claim 25.
32. The fiberglass product of claim 25, wherein the product is
building insulation.
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 a 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 to
all 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 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
so as 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 matrix 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 fiberglass 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 glycerine or a
modestly oxyalkylated glycerine 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 Non-Wovens", 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 can result 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, 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 modified with a fatty acid, and a polyol. 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 polycarboxy polymer is modified with a fatty acid, and
preferably an unsaturated fatty acid. Modifying the polycarboxy
polymer, preferably a polyacrylic acid, with the fatty acid, is
believed to render the binder, and hence the fiberglass mat to
which the binder is applied, essentially waterproof. As a result,
fiberglass insulation made with the binder of the present invention
avoids the possible problem of coming apart when subjected to
water, as the binder of the present invention has been found to
repel the water and maintain the integrity of the bond with the
fiberglass.
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,
-methyleneglutaric acid, and the like. Alternatively, 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, -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 results in a final product
which exhibits excellent recovery and rigidity.
[0024] An important aspect of the present invention is that the
polycarboxy polymer, and preferably polyacrylic acid, is modified
by reaction with a fatty acid, preferably an unsaturated fatty
acid. Unsaturated fatty acids are usually vegetable-derived and
contain alkyl chains of 18 or 22 carbon atoms with the
characteristic end group --COOH. In a preferred embodiment the
fatty acid is oleyl carboxylic acid. The fatty acid can be
incorporated into the polycarboxy polymer at any time during the
preparation of the polymer. The fatty acid is thereby incorporated
into the polymer itself. Such modification has shown that the
resulting polymer exhibits excellent water repellancy in a resin
formulation comprising said modified polycarboxy polymer and a
polyol.
[0025] 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(-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).
[0026] 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, however, thus, a 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 1/0.2 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 lower pH
binder.
[0027] In a most preferred embodiment the binder of the present
invention also contains an imidazoline material, as an additive.
The presence of the imidazoline has been found to further render
the binder less prone to absorb water, as described in co-owned and
co-pending U.S. application Ser. No. 10/282,076, filed Oct. 28,
2002. As a result, its action, in combination with the fatty acid
modified polycarboxy polymer, may better maintain the integrity of
the bond between the binder and glass fiber, and hence the
integrity of the entire mat product, when exposed to liquid water.
The binder bond, and hence the overall product, is more
water-proof.
[0028] The preferred imidazoline is generally 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. 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.
[0029] It is also most preferred that the imidazoline be hydroxy
functional as it acts as a coupling agent for the resin to glass
adhesion. Since acrylic resins do not react very effectively with
silane coupling agents, this is an additional advantage in using an
imidazoline.
[0030] It is preferred that the formaldehyde-free curable aqueous
binder composition of the present invention also contain 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.
[0031] 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 from 3.5
to 4.5 also allows one to avoid serious problems with corrosion of
the equipment while still realizing the benefits of the low pH.
Lower pH can also be used, e.g., less than 3.5, and is actually
preferred, with appropriate handling precautions.
[0032] 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.
[0033] The formaldehyde-free curable aqueous binder composition may
be prepared by admixing the polyacid of the present invention
modified with a fatty acid, the polyol, and the
phosphorous-containing accelerator using conventional mixing
techniques. In another embodiment, a carboxyl- or
anhydride-containing addition polymer modified with the fatty acid,
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 the
modified polyacid of the present invention. 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.
[0034] Once the composition of the fatty acid modified polyacid and
the polyol has been prepared, in a preferred embodiment, other
additives, such as the imidazoline, can then be mixed in with the
composition to form the final composition to be sprayed on the
fiberglass. 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 fatty acid modified polyacid.
[0035] 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.quadrature. 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 1{fraction
(1/2)} minutes. The fibrous glass having a cured, rigid binder
matrix emerges from the oven in the form of a batt which may be
compressed for packaging and shipping and which will thereafter
substantially recover its vertical dimension when
unconstrained.
[0036] The formaldehyde-free curable aqueous composition may also
be applied to an 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.
[0037] The waterborne formaldehyde-free composition of the present
invention, 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.
[0038] 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.
[0039] 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.
* * * * *