U.S. patent number RE28,957 [Application Number 05/575,560] was granted by the patent office on 1976-09-07 for synthetic resin compositions and methods of utilizing the same.
This patent grant is currently assigned to Johnson & Johnson. Invention is credited to Arthur H. Drelich, George J. Lukacs.
United States Patent |
RE28,957 |
Drelich , et al. |
September 7, 1976 |
**Please see images for:
( Certificate of Correction ) ** |
Synthetic resin compositions and methods of utilizing the same
Abstract
Methods of applying stable synthetic resin compositions to
porous .[.material.]. .Iadd.materials .Iaddend.the synthetic resin
composition comprising: (1) a synthetic resin; (2) a polyvalent
metal complex coordination compound; and (3) a water-soluble,
ionically active ammonium or alkali metal salt of an acid capable
of being chemically converted into an ionically inactive polyvalent
metal salt of said acid by chemical reaction and precipitation or
sequestration of said polyvalent metal salt, and substantially
immediately destroying the stability of the synthetic resin
compositions to precipitate the resin on the porous materials under
controlled migration conditions.
Inventors: |
Drelich; Arthur H. (Plainfield,
NJ), Lukacs; George J. (Perth Amboy, NJ) |
Assignee: |
Johnson & Johnson (New
Brunswick, NJ)
|
Family
ID: |
26948093 |
Appl.
No.: |
05/575,560 |
Filed: |
May 8, 1975 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
260613 |
Jun 7, 1972 |
03849173 |
Nov 19, 1974 |
|
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Current U.S.
Class: |
427/331; 427/288;
427/324; 427/342; 524/407; 524/416; 442/102; 427/283; 427/322;
427/340; 427/341; 428/198; 524/413 |
Current CPC
Class: |
C08J
3/03 (20130101); D06M 11/62 (20130101); D06M
11/67 (20130101); D06M 13/184 (20130101); D06M
13/192 (20130101); D06M 13/224 (20130101); D06M
15/244 (20130101); D06M 15/263 (20130101); D06M
15/333 (20130101); B05D 3/10 (20130101); Y10T
442/2352 (20150401); Y10T 428/24826 (20150115) |
Current International
Class: |
C08J
3/03 (20060101); D06M 11/00 (20060101); D06M
15/333 (20060101); D06M 13/00 (20060101); D06M
15/21 (20060101); D06M 11/62 (20060101); D06M
13/224 (20060101); D06M 13/192 (20060101); D06M
15/244 (20060101); D06M 15/263 (20060101); D06M
13/184 (20060101); D06M 11/67 (20060101); C08J
3/02 (20060101); B05D 003/10 (); B32B 023/02 ();
B32B 027/02 () |
Field of
Search: |
;427/340,331,243,283,288,341,342,322,324 ;428/198,290
;260/29.6MM,29.7M,29.7N,29.6RW,29.6M |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lusignan; Michael R.
Assistant Examiner: Schmidt; William H.
Claims
We claim:
1. A method of applying a stable synthetic resin composition having
an alkaline pH to porous materials and controlling the migration
thereon which comprises: applying to porous materials a stable
synthetic resin composition having an alkaline pH and comprising:
(1) from about 0.1 percent to 60 percent by weight on a solids
basis of a .Iadd.carboxylated .Iaddend.synthetic resin; (2) from
about 0.01 percent to about 5 percent by weight, based on the
weight of said synthetic resin of a polyvalent metal complex
coordination compound; and (3) a water-soluble, ionically-active
ammonium or alkali metal salt of an acid capable of being
chemically converted into an ionically-inactive polyvalent metal
salt of said acid by chemical reaction and precipitation or
sequestration of said polyvalent metal salt, said salt being
capable of sequestering or precipitating the metal in said
polyvalent metal complex coordination compound and being present in
an amount of from about 5 percent to about 90 percent molecular
equivalent on a stoichiometric basis of said polyvalent metal and
substantially immediately destroying the stability of said
synthetic resin composition to coagulate and precipitate the resin
on said porous materials under controlled migration conditions.
2. A method of applying a stable synthetic resin composition having
an alkaline pH to porous materials and controlling the migration
thereon as defined in claim 1 wherein the stability of said
synthetic resin composition is destroyed by diluting the same
substantially immediately after it is applied to said porous
materials.
3. A method of applying a stable synthetic resin composition having
an alkaline pH to porous materials and controlling the migration
thereon as defined in claim 1 wherein the stability of said
synthetic resin composition is destroyed by acidifying the same
substantially immediately after it is applied to said porous
materials.
4. A method of applying a stable synthetic resin composition having
an alkaline pH to porous materials and controlling the migration
thereon as defined in claim 1 wherein the coordination compound is
a polyvalent metal ammine complex coordination compound.
5. A method of applying a stable synthetic resin composition having
an alkaline pH to porous materials and controlling the migration
thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is an ammonium salt of phosphoric
acid.
6. A method of applying a stable synthetic resin composition having
an alkaline pH to porous materials and controlling the migration
thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is diammonium phosphate.
7. A method of applying a stable synthetic resin composition having
an alkaline pH to porous materials and controlling the migration
thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is an ammonium salt of a
dicarboxylic aliphatic acid.
8. A method of applying a stable synthetic resin composition having
an alkaline pH to porous materials and controlling the migration
thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is ammonium oxalate.
9. A method of applying a stable synthetic resin composition having
an alkaline pH to porous materials and controlling the migration
thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is an ammonium salt of an
aliphatic hydroxy acid.
10. A method of applying a stable synthetic resin composition
having an alkaline pH to porous materials and controlling the
migration thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is ammonium citrate.
11. A method of applying a stable synthetic resin composition
having an alkaline pH to porous materials and controlling the
migration thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is an ammonium salt of a
monocarboxylic aromatic acid.
12. A method of applying a stable synthetic resin composition
having an alkaline pH to porous materials and controlling the
migration thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is ammonium benzoate.
13. A method of applying a stable synthetic resin composition
having an alkaline pH to porous materials and controlling the
migration thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is an ammonium salt of a monobasic
aliphatic organic acid having at least 10 carbon atoms.
14. A method of applying a stable synthetic resin composition
having an alkaline pH to porous materials and controlling the
migration thereon as defined in claim 1 wherein the water-soluble,
ionically-active salt of an acid is ammonium palmitate.
15. A method of applying a stable synthetic resin composition
having an alkaline pH to porous materials and controlling the
migration thereon which comprises: applying to porous materials a
stable synthetic resin composition having an alkaline pH and
comprising: (1) from about 0.1 percent to about 60 percent by
weight on a solids basis of a synthetic resin; (2) from about 0.01
percent to about 5 percent by weight, based on the weight of said
synthetic resin of a polyvalent metal complex coordination
compound; (3) a water-soluble, ionically-active ammonium or alkali
metal salt of an acid capable of being chemically converted into an
ionically inactive polyvalent metal salt of said acid by chemical
reaction and precipitation or sequestration of said polyvalent
metal salt, said salt being capable of sequestering or
precipitating the metal in said polyvalent metal complex
coordination compound and being present in an amount of from about
5 percent to about 90 percent molecular equivalent on a
stoichiometric basis of said polyvalent metal, and (4) a
water-soluble polymeric carboxylic thickener; and substantially
immediately destroying the stability of said synthetic resin
composition to coagulate and precipitate the resin on said porous
materials under controlled migration conditions.
16. A method of applying a stable synthetic resin composition
having an alkaline pH to porous materials and controlling the
migration thereon which comprises: applying to porous materials a
stable synthetic resin composition having an alkaline pH and
comprising: (1) from about 0.1 percent to about 60 percent by
weight on a solids basis of a synthetic resin; (2) from about 0.01
percent to about 5 percent by weight, based on the weight of said
synthetic resin of a polyvalent metal complex coordination
compound; (3) a water-soluble, ionically-active ammonium or alkali
metal salt of an acid capable of being chemically converted into an
ionically-inactive polyvalent metal salt of said acid by chemical
reaction and precipitation or sequestration of said polyvalent
metal salt, said salt being capable of sequestering or
precipitating the metal in said polyvalent metal complex
coordination compound and being present in an amount of from about
5 percent to about 90 percent molecular equivalent on a
stoichiometric basis of said polyvalent metal; (4) a water-soluble
polymeric carboxylic thickener; and (5) a surfactant, and
substantially immediately destroying the stability of said
synthetic resin composition to coagulate and precipitate the resin
on said porous materials under controlled migration conditions.
Description
GENERAL BACKGROUND OF THE INVENTION
The present invention relates to synthetic resin compositions and
to methods of utilizing the same. More particularly, the present
invention relates to synthetic resin compositions and to methods of
applying such synthetic resin compositions to porous or absorbent
materials and controlling their spreading, diffusing, or migrating
thereon or their penetrating therein. Even more particularly, the
present invention is concerned with the so-called bonded,
"nonwoven" textile fabrics, i.e., fabrics produced from textile
fibers without the use of conventional spinning, weaving, knitting
or felting operations. Although not limited thereto, the invention
is of primary importance in connection with nonwoven fabrics
derived from "oriented" or carded fibrous webs composed of
textile-length fibers, the major proportion of which are oriented
predominantly in one direction.
Typical of such fabrics are the so-called "MASSLINN" nonwoven
fabrics, some of which are described in greater particularity in
U.S. Pat. Nos. 2,705,687 and 2,705,688, issued Apr. 5, 1955, to D.
R. Petterson et al. and I. S. Ness et al., respectively.
Another aspect of the present invention is its application to
nonwoven fabrics wherein the textile-length fibers were originally
predominantly oriented in one direction but have been recognized
and rearranged in predetermined designs and patterns of fabric
openings and fiber bundles. Typical of such latter fabrics are the
so-called "KEYBAK" bundled nonwoven fabrics, some of which are
described in particularity in U.S. Pat. Nos. 2,862,251 and
3,033,721, issued Dec. 2, 1958 and May 8, 1962, respectively, to F.
Kalwaites.
Still another aspect of the present invention is its application to
nonwoven fabrics wherein the textile-length fibers are disposed at
random by air-laying techniques and are not predominantly oriented
in any one direction. Typical nonwoven fabrics made by such
procedures are termed "isotropic" nonwoven fabrics and are
described, for example, in U.S. Pat. Nos. 2,676,363 and 2,676,364,
issued Apr. 27, 1954 to C. H. Plummer et al.
And still another aspect of the present invention is its
application to nonwoven fabrics which comprise textile-length
fibers and which are made basically by conventional or modified
aqueous papermaking techniques such as are described in greater
particularity in pending patent application Ser. No. 4,405, filed
Jan. 20, 1970 by P. R. Glor and A. H. Drelich. Such fabrics are
also basically "isotropic" and generally have like properties in
all directions.
The conventional base starting material for the majority of these
nonwoven fabrics is usually a fibrous web comprising any of the
common textile-length fibers, or mixtures thereof, the fibers
varying in average length from approximately 3/8 inch to about 21/2
inches. Exemplary of such fibers are the natural fibers such as
cotton and wool and the synthetic or man-made cellulosic fibers,
notably rayon or regenerated cellulose.
Other textile-length fibers of a synthetic or man-made origin may
be used in various proportions to replace either partially or
perhaps even entirely the previously named fibers. Such other
fibers include: polyamide fibers such as nylon 6, nylon 66, nylon
610, etc.; polyester fibers such as "Dacron," "Fortrel" and
"Kodel;" acrylic fibers such as "Acrilan," "Orlon" and "Creslan;"
modacrylic fibers such as "Verel" and "Dynel;" polyolefinic fibers
derived from polyethylene and polypropylene; cellulose ester fibers
such as "Arnel" and "Acele"; polyvinyl alcohol fibers; etc.
These textile-length fibers may be replaced either partially or
entirely by fibers having an average length of less than about 1/2
inch and down to about 1/4 inch. These fibers, or mixtures thereof,
are customarily processed through any suitable textile machinery
(e.g., a conventional cotton card, a "Rando-Webber," a papermaking
machine, or other fibrous web producing apparatus) to form a web or
sheet of loosely associated fibers, weighing from about 100 grains
to about 2,000 grains per square yard or even higher.
If desired, even shorter fibers, such as wood pulp fibers or cotton
linters, may be used in varying proportions, even up to 100
percent, where such shorter length fibers can be handled and
processed by available apparatus. Such shorter fibes have lengths
less than 1/4 inch.
The resulting fibrous web or sheet, regardless of its method of
production, is then subjected to at least one of several types of
bonding operations to anchor the individual fibers together to form
a self-sustaining web. One method is to impregnate the fibrous web
over its entire surface area with various well-known bonding
agents, such as natural or synthetic resins. Such over-all
impregnation produces a nonwoven fabric of good longitudinal and
cross strength, acceptable, durability and washability, and
satisfactory abrasion resistance. However, the nonwoven fabric
tends to be somewhat stiff and board-like, possessing more of the
properties and characteristics of paper or board than those of a
woven or knitted textile fabric. Consequently, although such
over-all impregnated nonwoven fabrics are satisfactory for many
uses, they are still basically unsatisfactory as general purpose
textile fabrics.
Another well-known bonding method is to print the fibrous webs with
intermittent or continuous straight or wavy lines, or areas of
binder extending generally transversely or diagonally across the
web and additionally, if desired, along the fibrous web. The
resulting nonwoven fabric, as exemplified by a product disclosed in
the Goldman U.S. Pat. No. 2,039,312 and sold under the trademark,
"MASSLINN," is far more satisfactory as a textile fabric than
over-all impregnated webs in that the softness, drape and hand of
the resulting nonwoven fabric more nearly approach those of a woven
or knitted textile fabric.
The printing of the resin binder on these nonwoven webs is usually
in the form of relatively narrow lines, or elongated rectangular,
triangular or square areas, or annular, circular, or elliptical
binder areas which are spaced apart a predetermined distance which,
at its maximum, is preferably slightly less than the average fiber
length of the fibers constituting the web. This is based on the
theory that the individual fibers of the fibrous web should be
bound together in as few places as possible.
The nominal surface coverage of such binder lines or areas will
vary widely depending upon the precise properties and
characteristics of softness, drape, hand and strength which are
desired in the final bonded product. In practice, the nominal
surface coverage can be designed so that it falls within the range
of from about 10 percent to about 50 percent of the total surface
of the final product. Within the more commercial aspects of the
present invention, however, nominal surface coverages of from about
12 percent to about 40 percent are preferable.
Such bonding increases the strength of the nonwoven fabric and
retains substantially complete freedom of movement for the
individual fibers whereby the desirable softness, drape and hand
are obtained. This spacing of the binder lines and areas has been
accepted by the industry and it has been deemed necessarily so, if
the stiff and board-like appearance, drape and hand of the over-all
impregnated nonwoven fabrics are to be avoided.
The nonwoven fabrics bonded with such line and area binder patterns
have had the desired softness, drape and hand and have not been
undesirably stiff or board-like. However, such nonwoven fabrics
have also possessed some disadvantages.
For example, the relatively narrow binder lines and relatively
small binder areas of the applicator (usually an engraved print
roll) which are laid down on the fibrous web possess specified
physical dimensions and inter-spatial relationships as they are
initially laid down. Unfortunately, after the binder is laid down
on the wet fibrous web and before it hardens or becomes fixed in
position, it tends to spread, diffuse or migrate whereby its
physical dimensions are increased and its inter-spatial
relationships decreased. And, at the same time, the binder
concentration in the binder area is lowered and rendered less
uniform by the migration of the binder into adjacent fibrous areas.
One of the results of such migration is to make the surface
coverage of the binder areas increase whereby the effect of the
intermittent bonding approaches the effect of the over-all bonding.
As a result, some of the desired softness, drape and hand are lost
and some of the undesired properties of harshness, stiffness and
boardiness are increased.
Various methods have been proposed to prevent or to at least limit
such spreading, diffusing or migration tendencies of such
intermittent binder techniques.
For example, U.S. Pat. No. 3,009,822, issued Nov. 21, 1961 to A. H.
Drelich et al., discloses the use of a nonmigratory regenerated
cellulose viscose binder which is applied in intermittent fashion
to fibrous webs under conditions wherein migration is low and the
concentration of the binder in the binder area is as high as 35
percent by weight, based on the weight of the fibers in these
binder areas. Such viscose binder possesses inherently reduced
spreading, diffusing and migrating tendencies, thereby increasing
the desired softness, drape and hand of the resulting nonwoven
fabric. This viscose binder has found acceptance in the industry
but the use of other more versatile binders has always been
sought.
Resins, or polymers as they are often referred to herein as
interchangeable terms, are high molecular weight organic compounds
and, as used herein, are of a synthetic or man-made origin. These
synthetic or man-made polymers have a chemical structure which
usually can be represented by a regularly repeating small unit,
referred as a "mer," and are formed usually either by an addition
or a condensation polymerization of one or more monomers. Examples
of addition polymers are the polyvinyl chlorides, the polyvinyl
acetates, the polyacrylic resins, the polyolefins, the synthetic
rubbers, etc. Examples of condensation polymers are the
polyurethanes, the polyamides, the polyesters, etc.
Of all the various techniques employed in carrying out
polymerization reactions, emulsion polymerization is one of the
most commonly used. Emulsion polymerized resins, notably polyvinyl
chlorides, polyvinyl acetates, carboxylated styrene butadiene
rubbers, and polyacrylic resins, are widely used throughout many
industries. Such resins are generally produced by emulsifying the
monomers, stabilizing the monomer emulsion by the use of various
surfactant systems, and then polymerizing the monomers in the
emulsified state to form a stabilized resin polymer. The resin
polymer is usually dispersed in an aqueous medium as discrete
particles of colloidal dimensions (1 to 2 microns diameter or
smaller) and is generally termed throughout the industry as a
"resin dispersion," or a "resin emulsion" or "latex."
Generally, however, the average particle size in the resin
dispersion is in the range of about 0.1 micron (or micrometer)
diameter, with individual particles ranging up to 1 or 2 microns in
diameter and occasionally up to as high as about 3 or 5 microns in
size. The particle size of such colloidal resin dispersions vary a
great deal, not only from one resin dispersion to another but even
within one resin dispersion itself.
The amount of resin binder solids in the resin colloidal aqueous
dispersion varies from about 1/10 percent solids by weight up to
about 60 percent by weight or even higher solids, generally
dependent upon the nature of the monomers used, the nature of the
resulting polymer resin, the surfactant system employed, and the
conditions under which the polymerization was carried out.
These resin colloidal dispersions, or resin emulsions, or latexes,
may be anionic, non-ionic, or even polyionic and stable dispersions
are available commercially at pH's of from about 2 to about 11.
As will be pointed out in greater detail, such resin dispersions
are used in the present inventive concept at alkaline pH ranges.
Various alkaline reagents, such as ammonia, are therefore added to
bring the pH out of the acid range.
The amount of resin which is applied to the porous or absorbent
material varies within relatively wide limits, depending upon the
resin itself, the nature and character of the porous or absorbent
materials to which the resins are being applied, its intended use,
etc. A general range of from about 4 percent by weight up to about
50 weight percent by weight, based on the weight of the porous or
absorbent material, is satisfactory under substantially all uses.
Within the more commercial limits, however, a range of from about
10 percent to about 30 percent by weight, based on the weight of
the porous or absorbent material, is preferred.
Such resins have also found use in the coating industries for the
coating of knitted fabrics, woven fabrics, paper, paper products,
leather, and other materials. The resins are also used as adhesives
for laminating films, sheets and like materials or for bonding
fibrous webs. These resins have also found wide use as additives in
the manufacture of paper, the printing industry, the painting
industry, the decorative printing of textiles, and in other
industries.
In most instances, the resin is colloidally dispersed in water and,
when applied from the aqueous medium to a porous or absorbent sheet
material which contains additional water is carried by the water
until the water is evaporated or otherwise driven off. If it is
desired to place the resin only on the surface of the wet porous or
absorbent sheet material and not to have the resin penetrate into
the porous or absorbent sheet material, such is usually not
possible inasmuch as diffusion takes place between the aqueous
colloidal resin and the water in the porous material. In this way,
the colloidal resin tends to spread into and throughout the porous
material and does not remain merely on its surface.
Or, if it is desired to deposit the resin in a specific
intermittent print pattern, such as is used in bonding nonwoven
fabrics, the aqueous colloid tends to diffuse, spread or migrate
and to wick along the individual fibers and to carry the resin with
it beyond the confines of the nominal intermittent print pattern.
As a result, although initially placed on the nonwoven fabric in a
specific intermittent print pattern, the ultimate pattern goes far
beyond that due to the spreading of migration which takes place due
to the diffusion of the water and the resin, until the water is
evaporated or otherwise driven off.
We have discovered new resin binder compositions containing
polymers colloidally dispersed in aqueous media and new methods of
applying such resin binder compositions to porous or absorbent
material, as enumerated herein, whereby the resins are applied in a
controlled, relatively nonmigrating manner. If it is desired that
the resin be placed only on the surface of the porous or absorbent
material, our compositions and methods will allow this to be done.
Furthermore, if it is desired that the resin be impregnated
throughout the material, from one surface to the other surface,
again, our compositions and methods will allow this to be done.
SPECIFIC BACKGROUND OF THE INVENTION
In copending, commonly-assigned patent applications Ser. No. 65,880
filed Aug. 21, 1970, now U.S. Pat. No. 3,720,562 which issued Mar.
13, 1973, and Ser. No. 66,003 filed Aug. 21, 1970, now abandoned,
and Ser. No. 109,026 filed Jan. 22, 1971, now U.S. Pat. No.
3,706,595 which issued Dec. 19, 1972, there are disclosed various
synthetic resin compositions and methods of utilizing the same by
application to porous or absorbent materials. Basically, these
methods disclose applying stable synthetic resin compositions under
alkaline conditions to porous or absorbent materials which were
previously treated and wetted with controlled concentrations or
amounts of acidic media, aqueous media, or simply water. When the
synthetic resin compositions were applied to the pretreated porous
or absorbent materials, their stability was altered and destroyed
by the resulting altered acidic or dilutive conditions and they
immediately coagulated and precipitated on the porous or absorbent
materials under controlled migration conditions.
.[.".].More specifically, U.S. Pat. No. 3,706,595 discloses methods
of applying stable synthetic resin compositions as described herein
and having an alkaline pH to porous materials and controlling the
migration of such stable synthetic resin compositions on such
porous materials by destroying the stability of such synthetic
resin compositions by diluting the same substantially immediately
after being applied to such porous materials..[.".].
.[.".].And, also more specifically, U.S. Pat. No. 3,720,562
discloses methods of applying stable synthetic resin compositions
as described herein and having an alkaline pH to porous materials
and controlling the migration of such stable synthetic resin
compositions on such porous materials by destroying the stability
of such synthetic resin compositions by acidifying the same
substantially immediately after being applied to such porous
materials..[.".].
THE METHODS
Normally, the methods disclosed in these patent applications and in
the present case involve the use of standard or conventional
apparatus, such as described in FIG. 9 of U.S. Pat. No. 3,009,822.
Such methods employ an adjustable upper rotatable back-up roll and
an adjustable lower rotatable engraved print roll or applicator
roll, with the porous or absorbent materials passing under
adjustable pressure through the nip therebetween. In contact with
the applicator roll was a lowermost rotatable pick-up roll
partially immersed in a bath of the synthetic resin composition,
which pick-up roll picked up the synthetic resin composition and
transferred it to the applicator roll which applied it to the
porous or absorbent materials.
THE APPARATUS
A typical arrangement of such apparatus is shown in the FIGURE for
illustrative but not for limitative purposes. In this FIGURE, there
is shown an adjustable upper rotatable back-up roll 10, rotating on
a rotatable shaft 12, in adjustably controlled pressure contact
with a lower rotatable engraved print roll or applicator roll 14
rotating on a rotatable shaft 16. In contact with the applicator
roll 14 is a lowermost pick-up roll 18 rotating on a rotatable
shaft 20 and being partially immersed in a bath 22 of the synthetic
resin composition, which pick-up roll 18 picks up the synthetic
resin composition 24 and transfers it to the applicator roll 14
which applies it to a porous or absorbent material W passing
through the adjustable pressure nip of back-up roll 10 and
applicator roll 14. All these rolls are adjustable whereby the
pressure applied to the porous or absorbent material W is adjusted
to control the amount of pick-up of the synthetic resin composition
24 on the porous or absorbent material W. A doctor blade 26 is
employed to prevent build-up of the resin latex on the pick-up roll
18. This apparatus is generally conventional and standard and other
equivalent forms of apparatus are of use.
PRIOR OPERATING DIFFICULTIES
On occasion, it has been noted that the synthetic resin composition
lost its stability and thickened or prematurely coagulated and
precipitated in the bath 22 itself, prior to application to the
porous or absorbent material W. As a result, operating difficulties
were consequently occasionally encountered.
The premature coagulation and precipitation was evidenced primarily
by a thickening or "setting-up" of the synthetic resin composition
in the bath, particularly during the running of the operation.
Also, in some cases, it has been noted that a synthetic resin
composition having a viscosity, for example, .[.a.]. .Iadd.of
.Iaddend.1,000 centipoises, when originally prepared, thickened to
a viscosity of 20,000 centipoises or higher in a period of 1 week
storage, prior to plant operation. A comparable synthetic resin
composition, when protected by the application of the present
invention, thickened only slightly to a viscosity of 1,040
centipoises.
It is a primary purpose of the present inventive concept to prevent
such undesirable unstability, thickening and "setting-up" and
premature coagulation and precipitation of the synthetic resin
compositions during storage and during actual manufacturing
operations. It is a further purpose of our invention to permit the
formulation of more effective and versatile resin compositions.
GENERAL STATEMENT OF THE INVENTION
It has been discovered that such primary purpose and other
advantages and benefits to be described hereinafter are realized by
adding to the synthetic resin compositions described in said patent
applications controlled amounts of a stabilizing and
anti-coagulating and precipitating agent comprising a
water-soluble, ionically active ammonium or alkali metal salt of an
acid capable of being chemically converted into an ionically
inactive polyvalent metal salt of said acid by chemical reaction
and precipitation or sequestration of said polyvalent metal
salt.
It has not been established beyond any doubt but it is believed
that relatively small amounts of polyvalent metal cations
spontaneously ionize away from the polyvalent metal complex
coordination compound after formulation and during storage before
use and that these relatively small amounts of polyvalent metal
cations "trigger" the premature thickening, "setting-up",
coagulation or precipitation in the bath prior to application to
the porous or absorbent materials.
It is also believed that such undesirable premature coagulation and
precipitation by the relatively small amounts of polyvalent cations
is promoted and accelerated by unspecified amounts of acidic media,
aqueous media, or simply water, which are pressed out of the porous
materials as they pass through the nip of the back-up roll and
applicator roll to drain downwardly into the synthetic resin
composition in the bath. This, of course, changes the pH and/or
concentration of the complex coordination compound whereby its
stability is changed.
The addition of the stabilizing and anti-coagulating and
anti-precipitating agent serves to render the liberated polyvalent
metal cations innocuous and ionically inactive by chemical reaction
and precipitation or sequestration of the polyvalent metal cations.
The action of the stabilizing and anti-coagulating agent is thus
actually a scavenging action. In this way, the synthetic resin is
unaffected and the viscosity of the synthetic resin composition is
relatively stabilized.
In order to understand and explain the probable mechanism of the
actions taking place, it is instructive to show a typical
equilibrium reaction involving a divalent complex metal
compound:
or
Prior to this invention, problems were sometimes encountered by the
premature liberation of the M.sup.+.sup.+ cation which caused
premature thickening or coagulation of the resin component in the
binder formulation. This liberation of the metal cation can be
triggered by an increase in concentration of H.sub.2 O by dilution
or a decrease in concentration of NH.sub.4 OH by dilution,
neutralization, or evaporation. The scavenging agents which we have
discovered effectively inactivate the liberated M.sup.+.sup.+
cation.
Based on simple considerations of reaction kinetics, the removal of
M.sup.+.sup.+ from the system should shift the equilibrium to
continuously form more ionic M.sup.+.sup.+ cations to maintain the
constancy of the value of the reaction constant k. Unexpectedly and
surprisingly, this does not appear to happen, or to happen so
slowly that we can increase the stability of a formulation from
several hours to many weeks.
THE SYNTHETIC RESIN
The improved synthetic resin compositions of the present invention
comprise from about 0.1 percent to about 60 percent by weight on a
solids basis of a colloidal synthetic resin and may be of a self
cross-linking type, or an externally cross-linking type, or may not
be cross-linked.
Specific examples of such colloidal synthetic resins include:
.Iadd.carboxylated synthetic resins .Iaddend.polymers and
copolymers of vinyl halides such as plasticized and unplasticized
polyvinyl chloride, polyvinyl chloride-polyvinyl acetate,
ethylene-vinyl chloride, etc.; polymers and copolymers of vinyl
esters such as plasticized and unplasticized polyvinyl acetate,
ethylene-vinyl acetate, acrylic-vinyl acetate, etc.; polymers and
copolymers of the polyacrylic resins such as ethyl acrylate, methyl
acrylate, butyl acrylate, ethyl-butyl acrylate, ethyl hexyl
acrylate, hydroxyethyl acrylate, dimethyl amino ethyl acrylate,
etc.; polymers and copolymers of the polymethacrylic resins such as
methyl methacrylate, ethyl methacrylate, isopropyl methacrylate,
butyl methacrylate, etc.; polymers and copolymers of acrylonitrile,
methacrylonitrile, acrylamide, N-isopropyl acrylamide, N-methylol
acrylamide, methacrylamide, etc.; vinylidene polymers and
copolymers, such as polyvinylidene chloride, polyvinylidene
chloride-vinyl chloride, polyvinylidene chloride-ethyl acrylate,
polyvinylidene chloride-vinyl chloride-acrylonitrile, etc.;
polymers and copolymers of polyolefinic resins including
polyethylene, polypropylene, ethylene-vinyl chloride and
ethylene-vinyl acetate which have been listed previously; the
synthetic rubbers such as 1,2-butadiene, 1,3-butadiene,
2-ethyl-1,3-butadiene, high, medium and carboxylated
butadiene-acrylonitrile, butadiene-styrene, chlorinated rubber,
etc., natural latex; the polyurethanes; the polyamides; the
polyesters; the polymers and copolymers of the styrenes including
styrene, 2-methyl styrene, 3-methyl styrene, 4 -methyl styrene,
4-ethyl styrene, 4-butyl styrene; natural latex; phenolic
emulsions, etc.
These resins may be used either as homopolymers comprising a single
repeating monomer unit, or they may be used as copolymers
comprising two, three, or more different monomer units which are
arranged in random fashion, or in a definite ordered alternating
fashion, within the polymer chain. Also included within the
inventive concept are the block polymers comprising relatively long
blocks of different monomer units in a polymer chain and graft
polymers comprising chains of one monomer attached to the backbone
of another polymer chain.
Other synthetic resins of particular applicability within the
principles of the present inventive concept are colloidal synthetic
resins containing a coordinating ligand.
The coordinating ligand is normally an acidic or proton donor
group, especially those containing terminal hydroxy groups.
Examples of hydroxy-containing coordinating ligands are: hydroxy
--OH; carboxy --COOH; sulfino --SO(OH) sulfo --SO.sub.2 (OH);
sulfonoamino-NHSO.sub.2 (OH); aci-nitro=NO(OH); hydroxyamino
--NHOH; hydroxyimino =NOH; etc. It is to be observed that these
hydroxy-containing radicals contain a hydrogen atom which is
capable of dissociating to form an H.sup.+ ion or proton.
The colloidal synthetic resins possessing a hydroxy-containing
coordinating ligand are obtained by copolymerizing: (1) from about
92 percent by weight to about 99 percent by weight of a monomer or
a mixture of monomers of the group comprising vinyl halide, vinyl
ester, or vinyl ether monomers including, for example, vinyl
chloride, vinyl acetate and vinyl ethyl ether; olefin monomers such
as ethylene and propylene; acrylic and methacrylic monomers
including, for example, ethyl acrylate, ethyl hexyl acrylate,
methyl acrylate, propyl acrylate, butyl acrylate, hydroxyethyl
acrylate, dimethyl amino ethyl acrylate, methyl methacrylate, ethyl
methacrylate, isopropyl methacrylate, butyl methacrylate,
acrylonitrile, methacrylonitrile, acrylamide, N-isopropyl
acrylamide, N-methylol acrylamide, methacrylamide; vinylidene
monomers such as vinylidene chloride; diene monomers including, for
example 1,2-butadiene, 1,3-butadiene, 2-ethyl-1,3-butadiene;
styrene monomers including, for example, styrene, 2-methyl styrene,
3-methyl styrene, 4-methyl styrene, 4-ethyl styrene, 4-butyl
styrene; and other polymerizable monomers; and (2) a relatively
small amount, on the order of from about 1 percent by weight to
about 8 percent by weight, of an unsaturated acid containing a
terminal hydroxy group such as the .alpha.,.beta.-unsaturated
carboxylic acids including acrylic acid, methacrylic acid, fumaric
acid, maleic acid, itaconic acid, crotonic acid, isocrotonic acid,
angelic acid, tiglic acid, etc. Anhydrides of such acids, where
they exist, are also of use. Other .alpha.,.beta.-unsaturated acids
are of use and include 2-sulfoethyl methacrylate, styrene sulfonic
acid, vinyl phosphonic acid, etc.
It is to be appreciated that more than one monomer may be included
in the polymerization with the .alpha.,.beta.-unsaturated acid. An
outstanding example of the use of more than one monomer is the
polymerization of butadiene and styrene with an
.alpha.,.beta.-unsaturatd acid such as acrylic acid, methacrylic
acid, fumaric acid, maleic acid, or itaconic acid. Anhydrides, for
example, maleic anhydride, are also of use.
THE WATER-SOLUBLE, POLYMERIC CARBOXYLIC THICKENER
Also of application within the principles of the present inventive
concept, either in lieu of the previously mentioned synthetic
resins or in addition thereto, are water-soluble, polymeric
carboxylic thickeners which are included in the resin composition
in amounts of from about 0.05 percent by weight to about 10 percent
by weight.
The water soluble polymeric carboxylic thickener may be selected
from a relatively large group of such materials which include, for
example: polyacrylic acid; polymeric crotonic acid; copolymers of
vinyl acetate and crotonic acid; copolymers of vinyl acetate and
acrylic acid; polyacrylic acid-polyacrylamide copolymers;
polymethacrylic acid; polymethacrylic acid-polyacrylamide
copolymers; carboxymethyl cellulose; carboxyethyl cellulose;
carboxypropyl cellulose; polycarboxy-methyl hydroxyethyl cellulose;
alginic acid; polymers of acrylic acid and acrylic acid esters;
polymers of .alpha.,.beta.-unsaturated carboxylic acids such as
itaconic acid; etc. These water soluble, polymeric, carboxylic
thickeners may be used in their acid forms but normally it is
preferred to use their water-soluble, neutralized salts, that is,
their sodium, potassium, lithium, ammonium, or like water soluble
salts.
THE SURFACTANTS
On occasion, anionic and nonionic surfactants are added to the
synthetic resin composition to create, enhance or to augment the
"triggering" action which initiates the coagulation and
precipitation of the synthetic resin. Such anionic and nonionic
surfactants are included in the synthetic resin composition in
amounts ranging from about 0.01 percent to about 5 percent by
weight, based on the weight of the synthetic resin solids.
Typical examples of such surfactants are: the alkyl aromatic
sulfonic acids, alkyl sulfonic acids, the carboxylic acids, and
other surfactants such as, for example, dodecyl benzene sulfonate,
octyl benzene sulfonate, hexyl benzene sulfonate, octadecyl benzene
sulfonate, octyl sulfonate, hexyl sulfonate, dodecyl sulfonate,
octadecyl sulfonate, and the sodium and potassium fatty acid soaps
containing from 5 to 18 carbon atoms. Other anionic surfactants
include sodium p-1-methyl alkyl benzene sulfonates in which the
alkyl group contains from 10 to 16 carbon atoms, the sodium
di-n-alkyl sulfosuccinates in which the alkyl groups contain from 4
to 12 carbon atoms, the potassium n-alkyl malonates in which the
alkyl group contains from 8 to 18 carbon atoms, the potassium alkyl
tricarboxylates in which the alkyl group contains from 6 to 14
carbon atoms, the alkyl betaines in which the alkyl group contains
from 6 to 14 carbon atoms, the ether alcohol sulfates, sodium
n-alkyl sulfates, containing from 6 to 18 carbon atoms, etc.
Non-ionic surfactants which are useful within the principles of the
present invention possess non-ionizing hydrophilic groups, and
include such surface-active agents as fatty acid mono-esters of
polyglycerol and pentaerythritol. Specific examples are glycerol
mono-stearate, glycerol mono-laurate, pentaeryltritol
mono-stearate, pentaerytritrol, mono-laurate, etc. Others include
glycol esters of fatty acids, prepared by treating the acid with
ethylene oxide. Specific useful surfactants include: nonyl phenoxy
poly (ethyleneoxy) ethanol; nonyl phenol polyglycol ether alcohol;
polyethylene glycol monolaurate; polyoxyethylene oleyl ether;
ethylene oxide condensates of castor oil; polyglycol palmitate
amide; ethoxylated alkyl phenol; lauric diethanolamide; octyl
phenoxy polyethoxy ethanol; difunctional block-polymers terminating
in primary hydroxy groups; etc.
The specific surfactant which is selected for use in the resin
composition does not relate to the essence of the invention. It is
merely necessary that it possess the necessary properties and
characteristics to carry out its indicated function of stabilizing
the resin composition prior to the time that coagulation and
precipitation of the resin is required. Additionally, in the event
that it is desired that the surfactant assist in or promote the
coagulation and precipitation function, then it must possess the
necessary anionic groups, as described hereinbefore, which are
capable of reaction due to the presence of the metal cations
released from the metal complex coordination compound.
THE POLYVALENT METAL COMPLEX COORDINATION COMPOUND
The polyvalent metal complex coordination compound is included in
the resin composition in an amount equal to from about 0.01 percent
by weight to about 5 percent by weight, based on the weight of the
previously mentioned synthetic resin or polymer solids.
Examples of polyvalent metal complex coordination compounds of
particular applicability when the porous or absorbent materials are
pretreated with acidic media are:
ammonium carbonato zirconate
ammonium heptafluoro zirconate
potassium tetracyano zincate
sodium tetrahydroxo zincate
sodium tetrahydroxo aluminate
potassium trioxalato aluminate
as defined herein, a metal complex coordination compound is one of
a number of types of metal complex compounds, usually made by
addition of organic or inorganic atoms or groups to simple
inorganic compounds containing the metal atom. Coordination
compounds are therefore essentially compounds to which atoms or
groups are added beyond the number possible of explanation on the
basis of electrovalent linkages, or the usual covalent linkages,
wherein each of the two atoms linked donate one electron to form
the duplet. In the cases of the coordination compounds, the
coordinate atoms or groups are linked to the atoms of the
coordination compound, usually by coordinate valences, in which
both the electrons in the bond are furnished by the linked atoms of
the coordinated group.
Other examples of polyvalent metal complex coordination compounds
of more universal utility but of particular applicability when the
porous or absorbent materials are pretreated with aqueous media
are:
hexammine chromium chloride
pentammine chloro chromium chloride
hexammine nickel chloride
tetrammine dinitro cobalt nitrate
hexammine cobalt chloride
hexammine cobalt iodide
hexammine cobalt nitrate
hexammine cobalt sulfate
hexammine cobalt bromide
hexammine nickel bromide
hexammine nickel chlorate
hexammine nickel iodide
hexammine nickel nitrate
tetrammine zinc carbonate
tetrammine zinc sulfate
tetrammine zinc nitrate
diammine zinc chloride
tetrammine zinc chloride
diammine copper acetate
tetrammine copper sulfate
tetrammine copper hydroxide
ammonium tetra thiocyanato diammine chromate
hexammine chromium chloride
chloro pentammine chromium chloride
As defined herein, a metal ammine complex coordination compound is
one of a number of types of metal complex compounds, usually made
by addition of organic or inorganic atoms or groups such as ammonia
(NH.sub.3) to simple inorganic compounds containing the metal atom.
Coordination compounds are therefore essentially compounds to which
atoms or groups are added beyond the number possible of explanation
on the basis of electrovalent linkages, or the usual covalent
linkages, wherein each of the two atoms linked donate one electron
to form the duplet. In the case of the coordination compounds, the
coordinated atoms or groups are linked to the atoms of the
coordination compound, usually by coordinate valences, in which
both the electrons in the bond are furnished by the linked atoms of
the coordinated group.
THE WATER-SOLUBLE, IONICALLY-ACTIVE SALT
The water-soluble, ionically active ammonium or alkali metal salt
of an acid (to be defined more particularly hereinafter) is present
in the resin composition in an amount of from about 5 percent to
about 90 percent molecular equivalent (stoichiometric basis) of the
polyvalent metal which is present and which is to be precipitated
or sequestered. That is to say, for example, if there is one mole
of the polyvalent metal present, then there is from about 0.05 to
0.90 mole of the water-soluble, ionically active ammonium or alkali
metal salt present.
Ammonium and alkali metal salts of acids naturally are selected
from the group consisting of ammonium, lithium, sodium and
potassium salts. Of these, ammonium is preferred. As a matter of
fact, in many cases where there is sufficient ammonium or alkali
metal hydroxide in the resin composition, the agent may be added in
the acid form rather than in the salt form and the water-soluble,
ionically active ammonium salt will be formed, in situ. The above
salts generally consist of the NH.sub.4, Na, etc., and salts of
acids listed below.
THE ACIDS
Examples of acids suitable for application within the principles of
the present invention are: inorganic mineral acids such as
ortho-phosphoric acid, hypophosphoric acid, metaphosphoric acid,
triphosphoric acid, tetraphosphoric acid, chromic acid, orthoboric
acid, metaboric acid, tetraboric acid, etc.; monobasic aliphatic
organic acids, preferably having at least 10 carbon atoms, such as
capric acid, lauric acid, myristic acid, palmitic acid, stearic
acid, oleic acid, linoleic acid, linolenic acid, etc.; dicarboxylic
aliphatic organic acids such as oxalic acid, malonic acid, succinic
acid, glutaric acid, adipic acid, pimelic acid, suberic acid, etc.;
aliphatic hydroxy acids such as citric acid, glycolic acid, lactic
acid, malic acid, tartaric acid, etc.; monocarboxylic aromatic
organic acids such as benzoic acid, o-toluic acid, m-toluic acid,
p-toluic acid, phenylacetic acid, cinnamic acid, etc.; hydroxy
aromatic organic acids such as salicylic acid, m-hydroxy benzoic
acid, p-hydroxy benzoic acid, mandelic acid, etc.; dicarboxylic and
polycarboxylic aromatic organic acids such as phthalic acid,
isophthalic acid, terephthalic acid, gluconic acid, etc.
Many of these acids are frequently also classified as chelating
agents and possess the ability to form chelated compounds wherein
the polyvalent metal cations which are associated with them are
rendered ionically inactive and remain in solution in sequestered
form.
Other acids which are more truly considered as chelating agents are
also suitable for application within the principles of the present
invention. Such chelating agents include: ethylene diamine
tetraacetic acid (EDTA); ethylene diamine tetrapropionic acid
(EDTPA); hydroxyethyl ethylene diamine triacetic acid (HEDTA);
ammonia triacetic acid (NTA); N-hydroxyethyl diethylene triamine
tetraacetic acid (HDTTA); etc.
The invention will be further described by reference to the
following Examples wherein there are disclosed preferred
embodiments of the present invention. However, it is to be
appreciated that such Examples are illustrative but not limitative
of the broader aspects of the inventive concept.
EXAMPLE I
A resin binder formulation suitable for bonding nonwoven fabrics
having the following composition is prepared:
______________________________________ Pounds
______________________________________ GAF 500-19A carboxylated
butadiene-styrene resin (50% solids) GAF Corporation 12.5 Water 6.0
Anti-foam agent 0.12 External curing agent for resin (80%) 0.55
Acrylic acid copolymer thickener Rohm and Haas Acrysol 51 (10%)
(ammonium 1.30 salt) Zinc tetrammine chloride (169 ml.) - 10% Zn
0.42 Content Plasticizer 0.60 Anionic surfactant (25%)
.[.0.25.]..Iadd.0.05.Iaddend.
______________________________________
The values in pounds in the above Example and in all other Examples
herein represent the weight in pounds of the constituent or the
solution added. To obtain the real weight of the added constituent,
if in a solution, you must multiply by the percent solids or
concentration of the constitutent in the solution.
The viscosity of the above-described composition is 1,000
centipoises, as initially prepared. The pH is on the alkaline side
(9.0). A one-pound sample is exposed to air for seven days and the
viscosity undesirably increases to 20,000 centipoises. Another
one-pound sample is protected by the addition of 0.01 pound of a 25
percent solution of diammonium phosphate. The one-pound sample of
the "protected" composition is exposed to air for seven days and
the viscosity increases to only 1,040 centipoises. There is no
excessive thickening or setting-up of the resin latex. The
beneficial results of the diammonium phosphate as an
anti-thickening and anti-coagulating agent are notable.
EXAMPLE II
A resin binder formulation suitable for bonding nonwoven fabrics
having the following composition is prepared:
______________________________________ Pounds
______________________________________ GAF-243 carboxylated
butadiene-styrene resin (50% solids) GAF Corporation 2.8 Water 0.9
Anti-foam agent 0.03 External curing agent for resin (80%) 0.11
Acrylic acid copolymer thickener Rohm and Haas Acrysol 51 (10%)
(ammonium salt) 0.18 Zinc tetrammine chloride (33 ml) - 10% Zn
content 0.083 Plasticizer 0.15 Anionic surfactant (25%) 0.03
Corrosion inhibitor (20%) 0.03
______________________________________
The viscosity of the above-described composition is 560
centipoises, as initially prepared. The pH is alkaline (9.2). A
0.7-pound sample is exposed to air for 24 hours and the viscosity
undesirably increases to 3,200 centipoises. Another 0.7-pound
sample is protected by the addition of 1 ml. of a 25 percent
solution of diammonium phosphate. The 0.7-pound sample of the
"protected" composition is exposed to air for 24 hours and the
viscosity increases to only 1,060 centipoises. There is no
excessive thickening or setting-up of the resin latex. The
beneficial results of the diammonium phosphate as an
anti-thickening and anti-coagulating agent are notable.
EXAMPLE III
The procedures of Example II are followed substantially as set
forth therein with the exception that the 0.7-pound sample is
protected by the addition of 1 ml. of a 25 percent solution of
ammonium citrate which increases the viscosity to 760 centipoises.
The sample of the "protected" composition is exposed to air for 24
hours and the viscosity increases further to only 1,060
centipoises. There is no excessive thickening or setting-up of the
"protected" resin latex. The beneficial results of the ammonium
citrate as an anti-thickening and anti-coagulating agent is
notable.
EXAMPLE IV
The procedures of Example II are followed substantially as set
forth therein with the exception that the 0.7-pound sample is
protected by the addition of 1 ml. of a 25 percent solution of the
ammonium salt of ethylene diamine tetraacetic acid. The sample of
the "protected" composition is exposed to air for 24 hours and the
viscosity increases moderately to only 1,400 centipoises. There is
no excessive thickening or setting-up of the "protected" resin
latex. The beneficial results of the ethylene diamine tetraacetic
acid as an anti-thickening and anti-coagulating agent are
notable.
EXAMPLE V
The procedures of Example IV are followed substantially as set
forth therein with the exception that ethylene diamine tetraacetic
acid is added rather than its ammonium salt. The dispersion is
sufficiently ammoniacal, that the ammonium salt is formed in situ,
and subsequently protects the dispersion from coagulation and
precipitation. No thickening or setting-up of the "protected" resin
latex is noted. The results are generally comparable.
EXAMPLE VI
The procedures of Example II are followed substantially as set
forth therein with the exception that the 0.7-pound sample is
protected by the addition of 1 ml. of a 121/2 percent solution of
ammonium oxalate. The sample of the "protected" composition is
exposed to air for 24 hours and the viscosity increases to only
1,600 centipoises. This increase in viscosity is significantly
below the unprotected sample and is still acceptable. The
beneficial results of such a small amount of ammonium oxalate as an
anti-thickening and anti-coagulating agent are notable.
EXAMPLE VII
A resin binder formulation suitable for bonding nonwoven fabrics
having the following composition is prepared:
______________________________________ Pounds
______________________________________ GAF-243 carboxylated
butadiene-styrene resin (50% solids) GAF Corporation 2.5 Water 0.08
Anti-foam agent 0.03 External curing agent for resin (80%) 0.10
Acrylic acid copolymer thickener Rohm and Haas Acrysol 51 (10%)
(ammonium salt) 0.15 Zinc tetrammine chloride (30 ml.) - 10% Zn
0.074 content Plasticizer 0.13 Anionic surfactant (25%) 0.03
Corrosion inhibitor (20%) 0.03
______________________________________
The viscosity of the above-described composition is 7,400
centipoises, as initially prepared. The pH is alkaline (9.3). A
0.7-pound sample is exposed to air for 24 hours and the viscosity
undesirably increases to 20,000 centipoises. Another 0.7-pound
sample is protected by the addition of 4 ml. of a 25 percent
solution of diammonium phosphate. The sample of the "protected"
composition is exposed to air for 24 hours, and the viscosity
decreases. There is no evidence of any thickening or setting-up of
the resin latex. The beneficial results of the diammonium phosphate
as an anti-thickening and anti-coagulating agent are notable.
EXAMPLE VIII
A resin binder formulation suitable for bonding nonwoven fabrics
having the following composition is prepared:
______________________________________ Pounds
______________________________________ GAF-243 carboxylated
butadiene-styrene resin (50% solids) GAF Corporation 2.5 De-ionized
water 0.8 Anti-foam agent 0.03 External curing agent for resin
(80%) 0.10 Acrylic acid copolymer thickener Rohm and Haas Acrysol
51 (10%) (ammonium 0.15 salt) Zinc tetrammine chloride (169 ml.) -
10% Zn .[.0.074.]..Iadd.0.42.Iaddend. content Plasticizer 0.13
Anionic surfactant (25%) 0.03
______________________________________
The viscosity of the above-described composition is 7,400
centipoises, as initially prepared. The pH is alkaline (9.4). A
0.7-pound sample is exposed to air for 24 hours and the viscosity
increases to 20,000 centipoises. Another 0.7-pound sample is
protected by the addition of 1 ml. of a 25 percent solution of
diammonium phosphate. The 0.7-pound sample of the "protected"
composition is exposed to air for 25 hours and the viscosity
decreases to 2,800 centipoises. The beneficial results of the
diammonium phosphate as an anti-thickening and anti-coagulating
agent are notable.
EXAMPLE IX
A fibrous card web weighing about 750 grains per square yard and
comprising 100 percent bleached rayon fibers 1.5 denier and 1 9/16
inches in length is intermittently print bonded by the rotogravure
process using an engraved roll having a diamond print pattern
therein. Apparatus such as illustrated in the FIGURE is used. There
are approximately four lines per inch in each of two directions,
crossing to form a diamond pattern and each set of lines is
approximately 30.degree. to the cross axis of the fibrous web. The
width of each line, as measured on the engraved print roll, is
0.024 inch. The composition by weight of the resin binder
formulation used for the intermittent print bonding is:
1. 15 pounds of a 50 percent solids latex of GAF-243 terpolymer of
46 percent butadiene, 51 percent styrene and approximately 2
percent alpha-beta unsaturated carboxylic acid;
2. 5 pounds of de-ionized water;
3. 0.15 pound of an anti-foam agent;
4. 0.60 pound of 80 percent solution of an external curing agent
for the resin;
5. 0.75 pound of a plasticizer for the resin;
6. 0.85 pound of a 10 percent solution of a polymeric thickening
agent -- Rohm & Haas Acrysol 51, a copolymer of acrylic acid
(ammonium salt)
7. 0.15 pound of an anionic surfactant (25 percent)
8. 0.2 pound of blue coloring
9. 0.15 pound of an anti-corrosion agent
10. 190 ml. (0.47 pound) of zinc tetraammine chloride
To a 5.6-pound sample of the above composition is added 0.03 pounds
of a 25 percent solution of diammonium phosphate. The viscosity of
the resulting composition, as initially prepared, is 400
centipoises. The pH is 9.
The fibrous card web is pretreated or premoistened with a large
amount of water to an extent of 250 percent moisture, based on the
weight of the fibers in the web. The extra dilution with water is
sufficient to destroy the stability of the resin dispersion when it
is applied to the fibrous web by a rotogravure printing process and
the resin dispersion immediately coagulates and precipitates in
place on the very wet fibrous web. The printed web is then
processed, treated and cured as described in the previous
referred-to patent applications.
The width of the binder line in the finished bonded nonwoven
product is not more than about 0.048 inch which represents a
controlled total migration of not more than about 100 percent.
The control over the bonding operation and production procedure is
very good. At no time is there any evidence of premature
coagulation or precipitation in the bath. There is substantially no
thickening or setting-up of the synthetic resin dispersion in the
bath prior to being applied to the nonwoven fabric.
The resulting bonded nonwoven fabric has excellent strength,
excellent softness, and excellent drape and hand.
EXAMPLE X
The procedures of Example IX are followed substantially as set
forth therein with the exception that an increased amount of 0.06
pound of the 25 percent solution of diammonium phosphate is added
to the 5.6-pound sample of the resin binder composition. The pH of
the resulting composition is 9.2 and the viscosity is 440
centipoises. The results are generally comparable to those obtained
in Example IX and the resulting bonded nonwoven fabric has
excellent strength, excellent softness and excellent drape and
hand.
EXAMPLE XI
The procedures of Example IX are followed substantially as set
forth therein with the exception that a further increased amount of
0.12 pound of 25 percent solution of diammonium phosphate is added
to a 5.6-pound sample of the resin binder composition. The pH of
the resulting dispersion is 9.2 and its viscosity is 360
centipoises.
There is substantially no excessive thickening, coagulating, or
premature coagulation of the resin latex in the bath. Calculation
of the amount of diammonium phosphate, however, indicates that
there is more than its stoichiometric equivalent present and the
excess diammonium phosphate interferes seriously subsequently upon
printing of the .[.web.]. .Iadd.wet .Iaddend. fibrous web and
control is lost over the migration and lateral spread of the
binder.
EXAMPLE XII
The procedurs of Example IX are followed substantially as set forth
therein with the following synthetic resin formulation:
______________________________________ Pounds
______________________________________ GAF-243 carboxylated
butadiene-styrene resin (50% solids) GAF Corporation 300 Anti-foam
agent 4 De-ionized water 100 Resin curing agent (80%) 12 Resin
plasticizer 15 Acrylic acid co-polymer thickening agent Rohm and
Haas Acrysol 51 (10%) (ammonium 15 salt) Zinc tetrammine chloride -
10% Zn 6.12 Anionic surfactant 0.50 Anti-corrosion agent 0.8
Diammonium phosphate (25%) 1.5
______________________________________
The control of the application of the protected synthetic resin
composition to the fibrous web is very good. The viscosity of the
synthetic resin composition at the outset is 600 centipoises and
this value does not change materially throughout the operation of
the binder application. There is no evidence of any premature
coagulation or precipitation of the resin binder composition in the
bath and there is no undesirable thickening or setting-up of the
resin prior to being applied to the fibrous web. The resulting
bonded nonwoven fabric has excellent strength, excellent softness,
and excellent drape and hand. It is acceptable to the industry.
EXAMPLE XIII
The procedures of Example I are followed substantially as set forth
therein with the exception that the following synthetic resin
formulation is used.
______________________________________ Pounds
______________________________________ Air Flex 510 ethylene vinyl
acetate co-polymer (50% solids) 2.5 Water 0.68 Anti-foam agent 0.03
Zinc tetrammine chloride 17.5 ml 0.044 Acrylic acid copolymer
thickener (10%) 0.47 (ammonium salt) Plasticizer for resin 0.25
Corrosion inhibitor 0.025 External curing agent for resin 0.05
______________________________________
The viscosity of the dispersion as initially prepared is 880
centipoises and the pH is 9.5. A sample of the resin is exposed to
air and the viscosity thereof increases to 20,000 centipoises in 24
hours.
A 0.7-pound sample of the resin dispersion is protected by the
addition thereof of 1 ml. of a 25 percent solution of diammonium
phosphate. After 24 hours, the viscosity of the resin dispersion is
840 centipoises. After 48 hours, the viscosity increases to 1,600
centipoises.
The beneficial results of the addition of diammonium phosphate are
notable.
To another 0.7-pound sample of the above resin is added 1 ml. of a
25 percent solution of ammonium citrate. After 24 hours, the
viscosity of the dispersion is 2,000 centipoises. The beneficial
results of the addition of ammonium citrate are notable.
EXAMPLE XIV
The procedures of Example IX are followed substantially as set
forth therein with the exception that .Iadd.the .Iaddend.zinc
tetrammine chloride is replaced by:
1. Zinc tetrammine sulfate;
2. Zinc tetrammine carbonate;
3. Zinc tetrammine nitrate.
The results are generally comparable to the results obtained in
Example IX. The bonded nonwoven fabric is processed with no
production difficulties. There is no thickening or setting-up of
the resin latex in the applicator bath. There is no premature
coagulation or precipitation in the bath of resin latex. The
resulting bonded nonwoven fabric has excellent strength, excellent
softness, and excellent hand and drape.
EXAMPLE XV
The procedures of Example I are followed substantially as set forth
therein with the exception that the diammonium phosphate is
replaced by:
1. ammonium benzoate;
2. ammonium palmitate
3. the sodium salt of ethylene diammine tetraacetic acid;
4. ammonium succinate;
5. sodium phosphate.
The results are generally comparable to the results obtained in
Example I. There is no excessive thickening or setting-up of the
resin latex. The beneficial results of the anti-thickening and
anti-coagulating agent are notable.
EXAMPLE XVI
The procedures of Example IX are followed substantially set forth
therein with the exception that the carboxylated butadiene styrene
resin is replaced by:
1. National Starch 4260, a polyacrylic resin;
2. Geon 576 polyvinyl .Iadd.chloride .Iaddend.resin;
3. National Starch 22K11 polyvinyl acetate resin.
The results are generally comparable to the results obtained in
Example IX. There is no excessive thickening or setting-up of the
resin latex in the bath. The beneficial results of the
anti-thickening and anti-coagulating resin are notable. The
properties of the bonded nonwoven fabric are generally comparable
to those obtained in Example IX.
EXAMPLE XVII
The procesures of Example IX are followed substantially as set
forth therein with the exception that the polymeric thickener
(Acrysol 51) is replaced by the:
1. sodium salt of Hercules carboxymethylcellulose designated as
grade 7H3S;
2. sodium salt of Hercules carboxymethylcellulose designated as
grade 7M;
3. sodium salt of Hercules carboxymethylcellulose designated as
grade 7L2;
4. kelco Kelgin F alginate (sodium salt)
The results are generally comparable to the results obtained in
Example IX. There is no excessive thickening or setting-up of the
resin latex in the bath. There is no evidence of any premature
coagulation or precipitation. The resulting bonded nonwoven fabric
has excellent strength, excellent softness, and excellent drape and
hand. It is acceptable to industry.
EXAMPLE XVIII
The procedures of Example I are followed substantially as set forth
therein with the exception that the following composition is
used:
______________________________________ Pounds
______________________________________ GAF-243 Carboxylated
butadiene styrene resin (50% solids) GAF Corporation 1.0 Water 0.3
Acrylic acid copolymer thickener Rohm and Haas Acrysol 51 (10%)
(ammonium 0.1 salt) Ammonium zirconyl carbonate (10 ml. - 10%
.[.ZnO.sub.2 .].ZrO.sub.2) 0.02 Plasticizer 0.05 Anionic surfactant
(25%) 0.01 ______________________________________
The viscosity of the above-described composition is .Badd.1200
centipoises as initially prepared. The pH is alkaline (pH 9.3).
Upon exposure to air for 4 days, the viscosity undesirably
increases to 1920 centipoises.
A 0.67-pound sample of the above resin composition is protected by
the addition of 1.5 ml. of a 25 percent solution of diammonium
phosphate. At the end of four days exposure to air, the viscosity
has risen only slightly to 1,400 centipoises.
There is no excessive thickening or setting-up of the resin latex
composition. The beneficial results of the diammonium phosphate as
an anti-thickening and anti-coagulating agent are notable.
EXAMPLE XIX
The procedures of Example I are followed substantially as set forth
therein with the exception that the following composition is
used:
______________________________________ Pounds
______________________________________ GAF-243 carboxylated
butadiene-styrene resin (50% solids) GAF Corporation 1.0 Water 0.3
Acrylic acid copolymer thickener Rohm and Haas Acrysol 51 (10%)
(ammonium 0.05 salt) Ammonium zirconyl carbonate (15 ml. - 10%
[ZrO.sub.2)] 0.03 Plasticizer 0.05 Anionic surfactant (25%) 0.01
______________________________________
The viscosity of the above-described composition is 240
centipoises. The composition is alkaline and has a pH of 9.3. Upon
exposure to air for 4 days, the viscosity of the composition
increases to 520 centipoises.
A 0.65-pound sample of the above resin composition is protected by
the addition of 2 ml. of 25 percent diammonium phosphate. The
viscosity of the resulting composition is 240 centipoises which,
after four days, rises 320 centipoises.
There is no excessive thickening or setting-up of the resin latex
composition. The beneficial results of the diammonium phosphate as
an anti-thickening and anti-coagulating agent are notable.
Although several specific examples of the inventive concept have
been described, the same should not be construed as limited thereby
nor to the specific features mentioned therein but to include
various other equivalent features as set forth in the claims
appended hereto. It is understood that any suitable changes,
modifications and variations may be made without departing from the
spirit and scope of the invention.
* * * * *