Note: Descriptions are shown in the official language in which they were submitted.
~2~ S
--2--
BAC~Q~OUN~_OF THE I~VENTION
The present invention relates to articles for
conditioning fabrics in an automatic clothes dryer wherein the
article compri6es a flexible substrate which carries a fabric
softening/antistatic agent (hereinafter "fabric conditioning
agent").
The employment of such fabric conditioning articles to
impart softening and antistatic effects to fabrics in a laundry
dryer has been described in the art. For example, U.S. Pat. No.
3,442,692 to Gaiser, issued May 6, 1969, described the
conditioning of fabrics in a laundry dryer by cotumbling the
fabrics with a flexible substrate carrying a conditioning agent.
The conditioning agent is transferred to the tumbling fabrics to
provide fabric conditioning which otherwise might only
inconveniently be effected by treatment, for example, during the
rinsing cycle of a laundering operation. Similarly, U.S. Pat.
No. 3,686,025 to Morton, issued August 22, 1972, describes an
article for conditioning fabrics in a laundry dryer. The article
comprises an absorptive substrate impregnated with a fabric
softening agent for the provision of fabric softening effects
with minimal stalning tendencles.
In the articles desaribed ln the above prior art and in
those which are presently available in the market, the fabric
conditioning agent is distributed uniformly on the substrate. As
a result, it 18 difficult, when visually examining a used
article, to determine if the article has been previously used to
I2677~;S
--3--
condition fabrics in a dryer, i.e., the article has a uniform
appearance prior to use, and after any given period of use in the
dryer it still has a uniform appearance.
It is an object of the present invention to provide
fabric conditioning articles for dryer use which indicate by
their appearance whether or not they have been previously used.
DE~I LED DESCRI PTI ON OF THE I NVENTI ON
According to the present invention, dryer-added fabric
conditioning articles are provided comprising a flexible web
substrate and a fabric conditioning composition wherein the
fabric conditioning composition is disposed upon the substrate
unevenly so as to provide an article having areas which are
visuall~ contrasted from each other. Preferably, these areas of
visual contrast form a pattern. In the course of usage the
degree' of contrast diminishes as the conditioning composition is
depleted from the substrate. This difference in appearance from
that of the original article provides a means of visually
distingui 8 hi ng articles which have been used from those which
have not.
In one embodiment, an article of the invention
comprises a flexible woven or nonwoven web substrate in a sheet
form having disposed thereon a fabric conditioning composition,
wherein the fabric conditionin~ composition is unevenly
distributed on the substrate in areas of high aoncentration of
fabric conditioning composition per unit area of substrate and
area6 of low concentration of fabric conditioning composition per
unit area of substrate so as to produce visual contrast between
~2677~
--4--
said high concentration and low concentration areas, whereln the
weight per unit area of composition in the high concentration
areas is at least about 2 times (preferably from about 3 to
about 10 times) the weight per unit area of composition in the
low concentration areas, and wherein the total weight ratio of
fabric conditioning compo6ition to ~ubstrate is from about 0.5:1
to about 5:1.
In another, and more preferred embodiment, a pigment is
incorporated into the portion of the fabric conditioning
composition which forms the areas of high concentration of fabric
conditioning composition on the substrate, thus enhancing the
degree of achievable visual contrast between the high
concentration and low concentration areas, and also making
po6sible the achievement of a given level of visual contrast
between areas of high concentration and low concentration with a
smaller difference in concentrations between these areas than is
possible when no pigment is used. Such preferred embodiment can
be described as an article comprising a woven or nonwoven web
substrate in a sheet form having disposed thereon a fabric
conditioning composition, wherein the fabric conditioning
composition is unevenly distributed on the substrate in areas of
high concentration of fabric conditioning compositlon per unit
area of substrate and areas of low concentration of fabric
oondltioning oomposition per unit area of substrate so as to
produce a visual contrast between said high concentratlon and low
concentration areas, wherein the portion of the fabric
conditioning composition in the areas of high concentration
~6775~;
--5--
contains from about 0.05% to about 10% (preferably from about
0.1% to about 7%), based on total weight of fabric conditioning
composition in said areas of high concentration, of a pigment
which causes the portion of fabric conditioning compo~ition in
the areas of high concentration to differ in color from the
portion of the fabric conditioning compoæition in the areas of
low concentration, wherein the weight per unit area of
composition in the high concentration areas is at least about
1.25 times (preferably from about 1.4 to about 3.0 times, and
most preferably from about 1.4 to about 2.0 time~) the weight
per unit area of composition in the low concentration areas, and
wherein the total weight ratio of fabric conditioning composition
to substrate is from about 0.5:1 to about 5:1.
In a method embodiment, the present invention also
compriæes a process of manufacturing dryer-added fabric
condltioning articles in sheet form wherein said articles
comprise a flexible woven or nonwoven web substrate having a
fabric conditioning agent disposed unevenly on said sub6trate so
as to produce a visual contrast between areas of high
concentration of fabric conditioning composition and areas of low
concentration of fabric conditioning composition, said process
compri6ing the steps of:
A. applying a first portlon of fabric conditioning
composition, in a melted state, uniformly
to the obverse face of said substrate;
. coollng the substrate so as to solidify the
said composition;
~LZ67~55
--6--
C. passing the cooled substrate through the nip
formed by the impression roll and the printing roll of
a rotary printing station, said station
comprising;
i) an impression roll,
ii) a rotogravure printing roll having recessed
areas in its face in the shape of a
pattern which it i8 desired to print
onto the substrate,
iii) a means for feeding melted fabric
conditioning composition to 6 aid rotogravure
roll, and
iv) a means (such as a doctor blade) for
scraping melted fabric conditioning
composition from the face of said rotogravure
roll, but leaving fabric conditioning
composition in the recessed areas of
the face of said roll,
thereby printing onto a portion of the area
of said substrate a second portion of fabric
conditioning composition in a pattern corresponding
to the reces6ed areas of said rotogravure roll,
the respectlve amounts of fabrl¢ conditioning
composition applied to the substrate in ~teps A
and C being such as to provide a total compositlon
to ~ubstrate ratio of from about 0.5:1 to 5:1
and to provide a concentration of fabric
~26~755
--7--
conditioning composition per unit area of
~ubstrate on the portion of the substrate
defined by the pattern, which is at least
1.25 times the concentration of fabric condi-
tioning composition per unit area on the
portion of the substrate not defined by
the pattern, the said second portion of
fabric conditioning composition containing
a pigment in sufficient quantity such that the
concentration of pigment in the total amount
of fabric conditioning composition in the
area defined by the pattern is from about
0.05% to about 10%; and
D. cooling the substrate so as to solidify the
fabric conditioning composition.
It will be useful at thi6 point to define certain terms
and concept6 u6ed throughout this 6pecification in describing the
present invention.
"Fabric conditioning agent" shall mean an organic
substance which i6 capable of imparting a fabric softening or
antistatic effect to fabrics.
"Fabric conditioning composition" ~hall mean a
composition comprising one or more ~abric oonditionlng agents.
"Substrate" shall mean a woven or nonwoven web
structure in a sheet configuration.
"Obverse face" shall mean the face of the substrate to
which the fabric conditioning composition 18 applied in
1~677~;
--8--
manufacturing articles of the invention.
"Reverse face~ shall mean the face of the substrate
which is on the reverse side of the substrate from the obverse
face.
~ Area~ shall mean a space defined by dimensions on the
obverse face of the substrate and shall include the entire
thickness of the subætrate under the said space. (The term
"under" is used with reference to the substrate lying
horizontally, with the obverse face facing upward.) Thus, for
example, a nonwoven web substrate which is 25 cm. wide, 25 cm.
long and 0.01 cm. thick has a total area of 625 sq. cm. for
purposes of describing the present invention.
It is to be understood that substrates used in the
articles of the invention can be relatively porous and absorbent.
Thus, with respect to a given portion of the space on the
obverse face of a 6ubstrate occupied by a fabric conditioning
composition, some of the compo~ition, becau6e of impregnation
into and through the porous, absorbent structure, can reside
within the substrate and on the reverse face of the substrate
under the given portion. Thus, within the context of the present
invention, the amount of fabric conditioning composition
"di6posed on" a portion of the area of the substrate, includes
the amount which resldes on the ~urface ~pace of the obverse
face, defined by the dimen~ion~ of that portion, a~ well as that
amount which resides within the 6ubstrate and on the reverse face
of the substrate d-rectly under the obverse face dimensions of
that portion. Consider, for example, a square porous nonwoven
~```f; j
.A .. ` .
~2677~i
g
web substrate which has an obverse face dimension of 25 cm. by 25
cm. and is 0.01 cm. thick. A 15 cm. diameter circle (177 sq.
cm.), having its center at the center of the obver~e face of the
substrate is marked off on the obverse face. 2 grams of melted
fabric conditioning composition are applied (e.g., by rotogravure
printing as described hereinafter) to the portion of the obverse
face defined by the circle. Because of the porous nature of the
substrate, some of the compo~ition penetrates into the substrate
and through the substrate to the reverse face, opposite the
circle on the obverse face. Since the circle occupies 28.3% (177
sq. cm - 625 s~. cm. x 100%) of the substrate area (as defined
above), 100% of the ;abric conditioning composition is disposed
upon 28.3% of the area of the substrate. The weight per unit
area of composition in the high concentration area is about 0.011
g./sq. cm., and in the low concentration area it is 0 g. per sq.
cm. The welght ratio of composition per unit area in the high
concentration area to the low concentration area is, therefore,
infinity.
If in the foregoing example, 50% of the 2 grams of
fabric conditioning composition (i.e., 1.0 g.) is applied
unlformly to the entire area of the obverse face of the
substrate, followed by application of the remaining 50~ ~i,e.,
1.0 g.) to the portion of the obverse ~ace dafined b~ the circle,
then 64.1% of the fabric condltionlng aomposition
~(1-0 5a~ 83) + 1.0 g.l ~ 100%
2 g.
lZ6775~
-10-
i6 disposed upon 28.3~ of the substrate area. In this case, the
weight per unit area of composition in the high concentration
area is 0.0072 g./sq. cm., and the weight per unit area of
composition in the low concentration area is 0.0016 g. per sq.
cm. The weight ratio of composition per unit area in the high
concentration area to the low concentration area is 4.5:l.
In the articles of the invention, the areas of high
concentration of fabric conditioning composition will generally
occupy from about 5% to about 60% of the total substrate area
while the remaining portion of the total 6ubstrate area consist6
of the areas of low concentration of fabric conditioning
composition. Preferably the high concentration areas occupy from
about 15% to about 50% (most preferably from about 25% to about
45%) of the total substrate area, the remainder of the total
substrate area consisting of areas of low concentration of fabric
conditioning composition.
Although articles of the invention can have all of the
fabric conditioning composition disposed in the areas of high
concentration (i.e., the "low concentration" areas contain no
fabric conditioning composition), it i6 preferred that fabric
conditioning composition be present ln both the high
conoentratiGn and lo~ conaentration areas.
~ he uneven distribution of fabric conditioning
composition onto the substrate in area of high concentration
and low concentration is desirably in the form of a pattern which
is aesthetically pleasing and/or informative to the user of the
~1 .
ilZ~775~
--11--
article. Thu~ by printing techniques such as rotogravure
printing, or rotary screen printing, the uneven distribution of
fabric conditioning composition can be used to form decorative
patterns such a~ geometric designs, flowers, lace, bells, clouds,
etc., or it can be used to form words such as the product brand
name.
Vescriptio~ of the D~awinas
Figure lA shows an article of the invention prior to
use. The areas of high concentration of fabric conditioning
composition have been printed onto the substrate in the form of
letters to form the word "brand." Figure lB depicts the
appearance of the article as the visual pattern begins to
disappear during use in the dryer. Figure lC depicts the
appearance of the article after the visual pattern has completely
di 8 appeared.
Figure 2 iB a schematic diagram depictin~ a means of
manufacturing articles of the invention by rotogravure printing,
and will be described in more detail hereinafter.
Figure 3 is a drawing o~ a pre~surized applicator head
which can be used to apply fabric conditioning composition to a
rotogravure printing roll, and will be described in more detail
hereinafter.
Figure 4 18 a drawing of a vertical cros~-sectlo~ of a
pressurized appl~ cator heAd whlah is a variation of the type of
appllcator head shown in Figure 3, and will be de~cribed in more
detail hereinafter.
~lZ~i775~
-12-
F~ic Cond1~1s~i~sLCom~ositions
The fabric conditioning compositions utilized in the
articles of the present invention can comprise any of the fabric
softening and/or antistatic agents (i.e., fabric conditioning
agents) conventionally used in dryer-added fabric softening
articles. The agents can be utilized individually or in
mixtures.
Such softening/antistatic agents are organic compounds
having at least one relatively long hydrocarbon group serving to
provide lubricity and/or antistatic effects. Among such groups
are al~yl groups contàining 8 or more carbon atoms and preferably
from 12 to 22 carbon atom6. Suitable fabric conditioning agent~
include cationic, anionic, nonionic, or zwitterionic compounds.
Cationic fabric conditioning agents are the preferred fabric
conditioning agents for use herein. They include the cationic
nltrogen-oontaining oompounds 6uch a6 quaternary ammonium
compounds which have one or two straight-chain organic groups of
at least eight carbon atoms. Preferably, they have one or two
such gro~ps of from 12 to 22 carbon atoms. Preferred cation-
active softener compounds include the qua~ernary ammonium
softener compounds corresponding to the formula.
N / ~ ~_
~67 75~ii
wherein R is hydrogen or an aliphatic grsup of from 12 to 22
carbon~; R1 is an aliphatic group having from 12 to 22 carbon
atoms/ R2 and R3 are each alkyl groups of from 1 to 3 carbon
atoms; and X is an anion selected from halogen, acetate
phosphate, nitrite and methyl sulfate radicals. The methyl
sulfate radical is the preferred anion.
Because of their excellent softening efficacy and ready
availability, preferred cationic softener compounds of the
invention are the dialkyl dimethylammonium 6alts (particularly
the methylsulfate salts, wherein the alkyl groups have from 12
to 22 carbon atoms. The alkyl groups are usually derived from
long-chain fatty acids, such as hydrogenated tallow fatty acids.
As employed herein, alkyl is intended to include unsaturated
compounds such as are present in aliphatic groups derived from
naturally occurring fatty oils. The term "tallow" refers to
fatty alkyl group6 derived from tallow fatty acids. Such fatty
acids give rise to quaternary softener compounds wherein R and R1
have predominantly from 16 to 18 carbon atoms. The term
"coconut" refer~ to fatty acid groups from coconut oil fatty
acids. The coconut-alkyl R and R1 groups have from about 8 to
about 18 carbon atoms and predominate in C12 to C14 alkyl
groups. Repre~entative examples of quaternary softener6 of the
invention include tallow trimethyl ammonium methyl B ul fate;
dltallow dimethyl ammonium methylsulfate; dlhexadecyl dimethyl
ammonium chloride; di(hydrogenated tallow) dimethyl ammonium
methylsulfate; dioctadecyl dimethyl ammonium methylsulfate;
dlelco~yl dimethyl ammonium methylsulfate; didocosyl dimethyl
lZ677~5
-14-
ammonium methylsulfate; di(hydrogenated tallow) diethyl ammonium
methylsulfate; dihexadecyl diethyl ammonium methylsulfate;
dihexadecyl diethyl ammonium methylsulfate; dihexadecyl dimethyl
ammonium acetate; ditallow dipropyl ammonium phosphate; ditallow
dimethyl ammonium nitrate; di(coconut-alkyl) dimethyl ammonium
chloride.
Other suitable cation-active softener compounds herein
are the quaternary imidazolinium ~alts. Preferred salts are
those conforming to the formula
H H +
H - C - C - H O
l l 11
. N ~ / N \ C2H4 - I - C ~ ~7 L
R8
wherein R6 i8 an alkyl containing from 1 to 4, preferably from 1
to 2, carbon atoms, R7 is an alkyl containing from 1 to 4 carbon
atom6 or a hydrogen radical, R8 is an alkyl containing from 8 to
22, preferably at least 15, carbon atoms, R5 is hydrogen or an
alkyl containing from 8 to 22, preferably at least lS, carbon
atoms, and X i~ an anion, preferably methylsulfate. Other
suitable anion~ include those di B cl osed with reference to the
cati oni c ~uaternary ammonlum fabric softeners de~cribed
hereinbefore. Particularly preferred are tho~e imidazolinium
compounds in which both R5 and R8 are alkyl8 of from 12 to 22
carbon atoms, e.g., 2-heptadecyl~ methyl [(2-~tearolyamido)
ethyll imidazolinium methylsulfate.
~.~677~;~
-15-
Other cationic quaternary ammonium fabric softeners,
which are useful herein include, for example, alkyl (C12 to C22)-
pyridinium methylsulfates, alkyl (C12 to C22)- alkyl (C1 to C3)-
morpholinium methylsulfates, and quaternary derivatives of amino
acids and amino e~ters.
The anionic fabrlc conditloning agents can include any
of the various surface-active anionic fabric-softening and
antistatic agents such as alkali metal or ammonium salts of
higher fatty alcohol sulfates, higher fatty alcohol ether
sulfates, higher fatty alcohol sulfonates, the linear higher
alkyl benzene sulfonates, the higher fatty acyl taurides and
isethionates. Generally, the cation of such compounds will be an
alkali metal or other water-solubilizing radical. The
hydrophobic moiety of such compounds will normally contain from
lO to 22 carbon atoms. Alkali metal and ammonium soaps of fatty
acids of from lO to 22 carbon atoms can also be employed and
include the sodium or potassium coconut or tallow soaps.
Suitable nonionic fabric conditioning agents that can be employed
are the polyoxyalkylene glycols, the higher fatty alcohol esters
of polyoxyalkylene glycols, the higher fatty alcohol ethers of
polyoxyalkylene glycols. Also suitable are the ethoxylates of
long-chain alcohols of from 8 to 22 carbon atoms such as the
ethoxylates of tallow alcohol with, for example, lO to ~0 moles
of 0thylene oxide. Other nonionlc~ include the amides such as
the alkanolamldes, e.g., the higher fatty amides and higher fatty
acid mono- and di-lower alkanolamides, wherein the long-chain
hydrophobic groups have from about lO to 22 carbon atoms.
~,~
lZ67 7~S
-16-
A particularly useful class of nonionic fabric
conditioning agents are the fatty acid esters of sorbitan and
ethoxylates of such esters. These materials, as well as cationic
fabric conditioning agents, are described more fully in U.S.
Patent No. 4,022,938 to Zaki et al., issued May 10, 1977.
Examples of suitable sorbitan esters are sorbitan
tristearate, sorbitan dipalmitate, sorbitan monolaurate and
sorbitan monstearate, as well as mixtures of sorbitan esters such
as mixtures of mono-, di- and tristearate esters of sorbitan.
Particularly preferred fabric conditioning compositions for use
in the articles herein contain from about 15% to about 85%
(preferably from about 20% to about 80%) by weight of a cationic
fabric conditioning agent such as ditallowdimethylammonium
methylsulfate and from about 85% to about 15% (preferably from
about 80% to about 20%) of a Cl~ to C26 fatty acid ester of
sorbitan, ~uch as sorbitan monostearate. All composition
percentages herein are "by weight" unles6 specified otherwise.
Other suitable softening agents include the
zwitterionic compounds of the formula
Rlo
I
R _ N~ _ CH2 ~ R12 ~ CH2S3
I
R11
wherein R1o and R11 are each methyl, ethyl, n-propyl, isopropyl,
~i~7~5
-17-
2-hydroxyethyl or 2-hydroxypropyl, Rg i6 a 12 to 22 carbon atom
alkyl or alkenyl and wherein 6aid alkyl or al~enyl contains from
0 to 2 hydroxyl substituents, from 0 to 5 ether linkages, and
from 0 to 1 amide linkage, and R12 i~ an alkylene group
contalning from 1 to 4 carbon atoms with from 0 to 1 hydroxyl
substituent6; particularly preferred are compounds wherein Rg i8
a carbon chain containing from 14 to 18 carbon atoms selected
from the group consisting of alkyls wherein said alkyls contain 0
to 2 hydroxyl substituents. Specific examples of the
particularly preferred compounds of this class include the
following: 3-(N-hexadecyl-N,N-dimethylammonio)-2-hydroxypropane-
l-sulfonate; and 3-(N-octadecyl-N,N-dimethylammonio)-propane-
1 -8ul fonate.
Other examples of conditioning agents suitable for the
articles herein are described in detail in Morton, U. S. Patent
No. 3,686,025, at column 5, line 51, to column 14, line 6.
The fabric conditioning compositions will generally comprise
a mixture of fabric conditioning agents in order to obtain the
optimum balance of conditioning performance. Cationic fabric
conditioning agents generally comprise at least about 10% by
weight of such mixtures, preferably about 20%. Generally,
however, cationic agents are not used in mixtures ~ith ~nionia
s~ents because of ahemical lnteraotion.
The amount of fabria aonditioning oomposition which i5
applied to the substrate to fabricate an article of the present
lnventlon i6 an amount suffiaient to provide the desired
conditlonlng effect without sub~tantial exce~s. Generally, the
~2677S~
-18-
amount used is sufficient to provide a conditioning agent:
substrate weight ratio of from about 0.5:1 to about 5:1,
preferably from about 1:1 to about 3:1.
The fabric conditioning compositions herein comprise
from about 85% to 100% fabric conditioning agent.
In addition to fabric condi~ioning agents the
conditioning composition can contain additives such as pigments,
perfumes, mothproofing agents, mildewproofing agents, fabric
brighteners, viscosity modifiers, such as clays and gums, etc.
Pigments are particularly useful additives for the
fabric conditioning compositions of the invention. In a
preferred aspect of the invention, the portion of fabric
conditioning composition which is disposed upon the areas of high
concentration of fabric conditioning composition in the articles
of the invention contains from about 0.05% to about 10%
(preferably from about 0.1% to about 7%) by weight of a pigment.
The percent of pigment is based upon the total weight of fabric
conditioning composition (i.e., pigment plu6 other composition
components) disposed upon the areas of high concentration of
fabric conditioning compooitlon. The pigment present in the
portion of composition which is disposed upon the high
concentration areas accentuates the visual difference between
the high concentration and low concentration area~. In the
absence of plgments, the fabric oon~itionlng compositlons herein
are generally tran61ucent and have a grayish or yellowish color
ln thelr solld state.
Any particulate material having a particle size from
1 Z67~75~;
--19--
about 6 to about 100 microns, which i5 inert to the other
components of the fabric conditioning compositlon and which is
insoluble in the melted composition i6 suitable for use as a
pigment herein. The pigment is incorporated into the composition
by blending it into a molten mixture of the other composition
components. Examples of suitable pigments are titanium dioxide,
calcium carbonate, calcium sulfate, magnesium oxide, clay,
ultramarine blue, phthalocyanine blue, ~Monastral"* fast blue,
permanent peacock blue, "Monastral"* fast green and pigment
green B.
The Substr~
The sub6trate component of the article of the present
invention i8 a woven or nonwoven flexible web substrate which
carries the fabric conditioning agent. Such substrates include
paper (e.g., paper towelling), woven or nonwoven cloth made from
natural or synthetic fibers, ànd foamed plastic material6 such as
polyurethane foamed sheets. The use of flexible webs as
substrate6 for carrying fabric conditioning agents for dryer use
is described in U.S. Patents 3,442,692, Gaiser, is6ued May 6,
1969; 3,895,128, Gaiser, issued July lS, 1975; and 3,686,02S,
Morton, is6ued August 22, 1972. Numerous examples of flexible
web substrate6 are di~olosed in these referenoes.
In order to obtain a good appeAr~noe ln the fabric
condltloning article6 herein, and to obtain even relea~e of the
*Trademark for phthalocyanine blue and phthalocyanine green
pigments.
~267~ S
-20-
fabric conditioning composition to the clothes in the dryer, it
is preferable that the web substrate be absorbent. "Absorbent~
as defined herein, is intended to mean a sub6trate with an
ab~orbent capacity (i.e., a parameter representing a substrate~s
ability to take up and retain water) of from 4 to 25. Suitable
paper and woven and nonwoven cloth absorbent substrates are
disclosed in U.S. Patent 3,686,025, issued August 22, 1972 to
Morton. As described in that patent, determination of absorbent
capacity values is made by using the capacity testing procedures
described in U.S. Federal Specifications UU-T-595b,
modified as follows:
(1) tap water is used instead of di~tilled water;
(2) The specimen is immersed for 30 seconds instead of
3 minutes;
(3) draining time is 15 seconds instead of 1 minute;
and
(4) the specimen iB immediately weighed on a torsion
balance having a pan with turned-up edges.
Absorbent capacity value~ are then calculated in accordance with
the formula given in said Specification. Based on this test,
one-ply, dense bleached paper (e.g., kraft or bond having a basis
weight of about 7.9 kg. per 100 square meters) has an ab~orbent
capacity of 3.5 to 4. Commercially availAble household one-ply
towellng paper has a value of 5 to 6; and commercially available
two-ply household toweling paper has a value of 7 to about 9.5.
If the 6ubstrate to be used 1B paper or a woven or
nonwoven cloth, rather than a foamed plastic material, the
i267~7~;5
-21-
absorbency should preferably be in the range of 4 to 12, most
preferably between 5 and 7. For foamed plastic materials, such
as foamed polyurethane, the preferable absorbency is in the
range of about 15 to 22.
The thickness of the substrates used herein can range
from about 0.005 cm. to about 0.5 cm. Generally, paper and woven
or nonwoven cloth substrates will have thicknesses of from about
0.005 cm. to about 0.02 cm. and the foamed plastic substrates
will have thicknesses of from about 0.05 cm. to about 0.5 cm.
The preferred substrates for use in the present
invention are nonwoven cloth substrates, which can generally be
defined as adhesively bonded fibrous or filamentous products
having a web or carded fiber structure (where the fiber strength
is suitable to allow carding), or comprising fibrous matters in
which the fibers or filaments are aistributed haphazardly or in
random array (l.e., an array of fi~ers in a carded web wherein
partial orientation of the fibers is frequently pre~ent, as well
as a completely haphazard distributional orientation), or
substantially aligned. The fibers or filaments can be natural
(e.g., wool, silk, jute, hemp, cotton, linen, sisal, or ramie) or
synthetic (e.g. rayon, cellulose ester, polyvinyl derivative6,
polyolefins, polyamides, or polyesters).
Methods of making nonwoven clo~h~ are not a part of
this invention and, being well-known in the art, are not
described in detail herèin. Generally, however, such cloths are
made by air- or water-laying processes in which the fibers or
filaments are first cut to desired lengths from long strands,
~.2677~
-22-
passed into a water or air stream, and then deposited onto a
scraen through which the fiber-laden air or water is passea. The
deposited fibers or filaments are then adhesively bonded
together, dried, cured, and otherwise treated as desired to form
the nonwoven cloth. Nonwoven cloths made of polyesters,
polyamides, vinyl resins, and other thermoplastic fibers can be
spun-bonded, i.e., the fibers are spun out onto a flat surface
and bonded (melted) together by heat or by chemical reactions.
The absorbent properties preferred herein are
particularly easy to obtain with nonwoven cloths and are provided
merely by building up the thickness of the cloth, i.e., by
superimposing a plurality of carded webs or mats to a thickness
adequate to obtain the necessary absorbent properties, or by
allowing a sufficient thickness of the fibers to deposit on the
screen. Any diameter or denier of the fiber (generally up to
about 10 denier) can be used, inasmuch as it is the free space
between each fiber that makes the cloth porous and is directly
related to the absorbent capacity of the cloth.
The choice of binder-resins used in the manufacture of
nonwoven cloths can provide substrates possessing a variety of
desirable traits. For example, the absorbent capacity of the
cloth can be increased, decreased or regulated by respectlvely
using a hydrophilic binder-resin, a hydrophoblo binder-resin, or
a mixture thereof, in the fiber bondlng step. Moreover, the
hydrophobia binder-resin, when used singly or a~ the predominant
compound of a hydrophobic-hydrophilic mixtuxe, provides nonwoven
cloths which are especially useful as substrates when the
2-23-
softening articles herein are u~ed with damp fabrics in an
automatic dryer.
When the substrate for the ~oftening articles herein is
a nonwoven cloth made from fibers deposited haphazardly or in
random array on the screen, the articles exhibit excellent
strength in all directions and are not prone to tear or separate
when used in the automatic clothes dryer.
Preferably, the nonwovsn cloth is water-laid or air-
laid and i8 made from cellulosic fibers, particularly from
regenerated cellulose or rayon. Such nonwoven cloth can ne
lubricated with any standard textile lubricant. Preferably, the
fibers are from 0.45. cm.to 5 cm. in length and are from 1.5 to 5
denier. Preferably, the fibexs are at least partially oriented
haphazardly, particularly substantially haphazardly, and are
adhesively bonded together with a hydrophobic or substantially
hydrophobic binder-resin, particularly with a nonionic self-
crosslinking acrylic polymer or polymer~. Preferably, the cloth
comprises about 70% fiber and 30% binder-resin polymer by weight
ana ha~ a basi6 weight of from about 17 to 29 grams per s~uare
meter.
It i8 preferred that the fabric softening articles of
the present invention be structured to have maximum
compatibility with conventional laundry dryer de~ign~. Whlle it
is preferred to employ the article~ of the pre~ent inventlon ln
an automatic laundry dryer, other equivalent machines can be
employed, and in ~ome instances, heat and drying air may be
omitted for part or all of the cycle. Generally, however, heated
~677~;5
-24-
air will be employed and ~uch air will be circulated frequently
in the dryer. Normally, there are from about 5 to 50 volume
changes of drying air in the dryer drum per minute and the air
moves at about 3.5 to 5 cubic meters per minute. These changing
volumes of air create a drawing or suction effect which can,
especially with small fabric loads, cause an item such as a sock,
handkerchief, or the like, or a fabric conditioning article, to
be dispo6ed on the surface of the air outlet of the dryer. A
usual load of fabrics of from about 5 to 7 pounds dry weight will
fill from about 10% to 70% of the volume of most dryers and will
normally po6e little difficulty.
A sufficient number of tumbling items will normally be
present to prevent any item from being drawn to the exhaust
outlet or to cause it to be removed from the outlet. In the
event, however, a fabric softening article is caused to be
disposed in relation to the air exhaust outlet in such a manner
as to cause blocXage of passing air, undesirable temperature
increases can re6ult. In the case of fabric conditioning
articles, the fabric conditioning compositions substantially melt
under conditions of heat, and the article may tend to adhere to
an exhaust outlet.
The problem of blockage can be solved by providlng
openings in the article ln the manner described in U.S. Patents
3,944,694, McQueary, is~ued March 16, 1976; and 3,956,556,
McQue~ry, issued May 11, lg76.
More speciflcally, slits or holes are cut through the
~ubstrate to allow free passage of air.
~.2~77'95
-25-
The slit openings are provided f~r two principal
purposes. Importàntly, the 61its permit passage of air in the
event the article is placed in a blocking relationship to the air
exhaust outlet. Moreover, the slit openings provide a degree of
flexibility or resiliency which causes the article to crumple or
pucker. The effect of such crumpling is that only a portion of
the air exhaust outlet will be covered by the softening article
in the event it is carried by the moving air stream to the
exhaust outlet. Moreover, the crumpled article is more readily
removed by tumbling fabrics than would be the case if the article
were placed in a flat relationship to the exhaust outlet.
The type and number of slit openings can vary
considerably and will depend upon the nature of the sub6trate
material, its inherent flexibility or rigidity, the nature of the
fabric conditioning composition, and the extent to which
increased pas 5 age of air therethrough is desired. The preferred
articles of this invention can comprise a large number of small
slit6 of various types or configurations, or fewer larger slits.
For example, a single rectilinear or wavy 6 1 i t, or a plurality
thereof, confined to within the area of a sheet and extending
close to opposite edges of the article, can be employed. By
maintaining a border around all edges of the artlole, A deBired
degree of flexibllity and ~urface areA avail~blllty to tumbling
fabrlcs can be maintained. While, for example, reotilinear slits
can be cut into a softening article completely to the edges of
the article, confinement of the slits to within the area of the
article will be preferred where the convenience of packaging the
iz67755
-26-
softening artlcle in roll form is desirea, i.e., the article will
better maintain its structural integrity when being handled by
the user.
According to one preferred embodiment of the invention,
a sheet of fabric softening article i8 provided with a plurality
of rectilinear slits extending in one direction, e.g., the
machine direction of the web substrate, and in a substantially
parallel relationship. The slits can be aligned or in a
staggered relationship. A preferred embodiment will contain from
5 to 9 of such 61its which will extend to within about 5 cm. and
preferably 2.5 cm. from the edge of the web material which is,
for example, a 22.9 cm. by 27.9 cm. sheet. In general, the
greater the number and the longer the slit6, the greater the
effect in preventing restriction of air flow. Such an article
permits the individual panel areas or sections within the
rectilinear slits to flex or move ln independent relationship to
each other and out of the plane of the sheet. This flexing
minimizes the probability that such an article will align itself
in a flat and blocking relationship to an exhaust outlet. The
inhèrent puckerin~ or crumpling tendency of the article allows
the article to contact the air outlet in such a manner as to
leave at least a portion of the air exhaust outlet uncovered. In
addition, the tumbling fabrlcs in the dryer will collide wlth the
crumpled artiole causing it to be removed from the exhaust
outlet. Removal i6 readily accompllshed by reason of the
protrusion of the crumpled article which makes it more availa~le
for contact with the tumbling load of fabrics in the dryer.
~2Ç~
-27-
The slit openings in the 60ftening articles of the
invention can be in a variety of configurations and sizes, as can
be readily appreciated. In some instances, it may be desirable
to provide slit openings as C-, U- or V-6haped slits. Such ~lits
arranged in a continuous or regular or irregular pattern are
desirable from the standpoint of permitting gate-like or flap
6tructures which permit the passage of air therethrough.
ArtiC~ a~Yf~Y~
The articles of the present invention are manufactured
by melting the fabric conditioning composition, distributing it
onto portions of the obverse face of the substrate to produce the
desired visual pattern, and then cooling to 601idify the fabric
conditioning composition. A preferred embodiment i8 one wherein
a portion (generally from about 20% to about 80% by weight) of
the total amount of fabric conditioning composition which is
applied to the substrate is evenly di6posed onto the entire
obverse face of the substrate, and then cooled to solidify this
portion of composition, before the remaining 80% to 20% by weight
of fabric conditioning composition i6 disposed onto particular
areas of the obverse face to produce areas of high concentration
of fabric conditioning compositlon and thereby produclng the
desired areas of vlsual contrast. ~he portion~ o~ composition
applled in the two steps can be portions of the 8ame aomposltion
or they can be portion~ of two different composltions.
Preferably, the portion of the fabric conditioning composition
which is evenly dlsposed onto the sub~trate i5 free of plgment
and the portion whlch 18 di.sposed onto particular areas to
~Z677~;5
-28-
produce areas of high concentrations, contains a sufficient
amount of pigment to produce a pigment concentration of from
about 0.05% to about 10% (preferably from about 0.1% to about
7%), by weight of pigment, based on the total amount of fabric
conditioning composition disposed upon the areas of high
concentration. The "total amount of fabric conditioning
composition" in the areas of high concentration includes the
originally unpigmented composition which was originally disposed
onto those areas, as well as the pigmented composition which has
been added.
In the articles of the invention the weight ratio of
total fabric conditioning composition to substrate should be
within the range of from about 0.5:1 to 5:1, and is preferably
from about 1:1 to about 3:1, with the fabric conditioning
composition being disposed unevenly on the substrate so as to
form the desired visual contrast effect between areas of high
concentratisn and low concentration. As indicated hereinbefore,
the uneven disposition of fabric conditioning composition is
desirably in the form of a pattern which is aesthetically
pleasing and/or informative to the user.
A convenient means of manufacturing articles of the
invention is by rotogravure printing, Figure 2 present~ a
schematia description of how article~ of the invention can be
made by such a process.
The substrate 2 from unwind roll 1 is drawn over heated
metal rollers 3 and 3a which are maintained at a temperature of
from about 38 C to 80 C. The eubstrate is then drawn over idler
~12Ç~
_~9_
rollers 4, 4a and 4b and over coating head 5, which is a clo6ed
container with a narrow slit opening at the top. The slit is
aligned perpendicular to the direction of movement of the
substrate and has a length equal to the width of the substrate.
Molten fabric conditioning composition (maintained at a
temperature of about 10 C to about 40 C above the melting point
of the composition) from reservoir 6 i6 pumped by pump 7 into
coating head 5 so as to maintain a positive pressure (140 to 1400
g./sq. cm.) of molten conditioning composition againRt substrate
2 through the slit of coating head 5, thereby applying a uniform
treatment of fabric conditioning composition to the obverse face
of substrate 2. (Pres 6 ures quoted herein are gauge pressures
unless specifi2d otherwise.) Substrate 2 is then drawn between
the nip of distribution rolls 8 and 8a and over distribution roll
8b, which are all maintained at a temperature of from about 55'C
to about 80 C. The function of the distribution rolls is to
distribute the composition evenly throughout the thickness of the
substrate. The pre~sure between the nip of distribution rolls 8
and 8a is maintained at a gauge pressure of about 2500 to 15,000
g. per liner cm. Substrate 2 is then drawn over cooling rolls 9
and 9a which are maintained at a temperature of about l'C to
about 25'C, to solidify the fabric conditioning composition
applied by coating head 5, Substrate 2 i8 then drawn under idler
roll 10 and between nip of impression roll 11 and rotogravure
roll 12, which picks up molten fabric conditioning composition
from print pan 13, which is supplied with fabric conditioning
compositlon from reservoir 14 via pump 15. The fabric
~2~77S~
-30-
conditioning composition in the print pan is maintained at a
temperature of at least 10 C (preferably about 10 C to about
40 C) above the melting point of the composition. Rotogravure
roll 12 contains reces~es in its surface face which are in the
pattern which it is desired to print on sub6trate 2. The
recesses are from about 0.009 cm. to about 0.030 cm. deep with
reference to the surface face of the roll. Preferably the
recesses consist of a plurality of individual cells, with a
density of from about 60 to about 600 cells per sq. cm. of
recessed area. After pickup of fabric conditioning composition
from print pan 13, rotogravure roll 12 contacts doctor blade 16
which scrapes exces fabric conditioning composition off the
~urface face of rotogravure roll 12, leaving fabric conditioning
composition in the recesses of said roll. Rotogravure roll 12
comes into contact with ~ubstrate 2 which i6 pressed between
lmpresslon roll 11 and rotogravure roll 12. The pressure exerted
by impre6sion roll 11 (preferably from about 2500 to 15,000 g.
per linear cm.) oauses fabric conditioning composition to be
transferred from the recesses of rotogravure roll 12 to the
obverse face of substrate 2 thus imprinting the desired pattern
of composition onto the substrate. Substrate 2 is then drawn
over cooling rolls 17, 17a and 17b, which are maintained at a
temperature of from about 1'C to about 25'C ~o A~ to ~olidify the
composition on sub~trate 2. Finally, substrate 2 passes over
idler rolls 18 and 18a and is wound onto rewind roll 19. Heated
rolls 3 and 3a, coating head 5, reservoir 6, pump 7, distribution
rolls 8, 8a and 8b and chill rolls 9 and 9a can be deleted from
~26~5
-31-
the process if it is not desired to treat the obverse face of the
substrate with fabric conditioning composition prior to applying
the patterned design from rotogravure roll 12.
Figure 3 depicts an alternate means to the open print
pan for applying melted fabric conditioning composition to the
rotogravure roll. This means i6 a pressurized applicator head
which fits against the rotogravure roll and feeds fabric
conditioning composition, under pressure to the roll. The head
comprise6 a back wall 20, a top wall, which is comprised of
doctor blade 21 and doctor blade retainer 22, a bottom wall which
is compriæed of doctor blade 23 and doctor blade retainer 24,
and side walls 25 and 26. Doctor blade retainer 24 contains
feed ports 27, 27a, 27b and 27c through which melted fabric
conditioning composition is pumped into the applicator head
through feed lines 28, 28a, 28b and 28c from a reservoir (not
shown). When used, the open front face of the applicator defined
by doctor blades 21 and 23 and the curved edges of side walls 25
and 26 is engaged against the surface of the rotogravure roll.
The applicator head is filled with melted fabric conditioning
composition which is maintained at a pressure of from about 140
to 2000 g. per sq. cm. As the rotogravure roll rotates in the
direction of arrows 29 and 30, it picks up fabric conditioning
composition from within the applicator he~d. As the rotogravure
roll rotates past doctor blade 23, the doctor blade scrape~
exoess fabric conditioning composition off the surface of the
surface face of the roll, leaving fabric conditioning composition
in the reces~es of the roll.
~677~S
-32-
Figure 4 depicts a vertical cross-~ection of a
pressurized applicator head, which is a variation of the type
depicted in Figure 3, in contact with a rotogravure roll 39.
The applicator head comprises a metal casing 31, which
encloses a chamber 32, on three sides, a plurality of inlet
ports, one of which is depicted and designated 33, an upper
doctor blade 34, a lower doctor blade 35, an upper doctor blade
retainer 36, a lower doctor blade retainer 37, and a plurality of
threaded holes, 38, 38a, 38b, 38c, and 38d by which end walls
(not shown) are fastened to the ends of the casiny. A leakproof
seal between the end walls and the casing is achieved by use of a
~Viton~ quad ring gasket. The ends of the doctor blades are
in movable sealed contact with the end walls which are made of
"Teflon6~" . This seal is achieved by the compression of the
blade against the "Teflon"~ In use, the chamber of the
applicator head is filled with melted fabric conditioning
composition and maintained at a pressure (about 140 to 2000 g.
per s~. cm.) by the pumping of melted fabric conditioning
composition into the chamber via the inlet ports. The opposing
forces eY.erted against the doctor blades by the fluid pressure
of the composition in the chamber and by the rotogravure roll 39,
retain the blades in very tight contact agalnst the rotogravure
*Trademark of du Pont for a fluoroelastomer based on the
copolymer of ~inylidene fluoride and hèxafluoropropylene.
** Trademark of du Pont for polytetrafluoroethylene~
~k
1267~5
-33-
roll. As the roll rotates in the direction of arrow 40, it picks
up fabric conditioning composition from within the applicator
head. As the roll rotates past doctor blade 34, the doctor blade
scrapes exceas conditioning composition off the surface face of
the roll, leaving fabric conditioning composition in the recesses
of the roll 41, 41a, 41b, and 41c.
The temperature of heated and cooled rolls in the
process can be maintained by circulating refrigerated or heated
liquid through the interior of the rolls.
The finished article material on rewind roll 19 can be
subsequently unwound and cut into individual sheets for packaging
and sale. Instead of individual sheets, the finished material
can be cut into lengths with perforated tear lines at
predetermined intervals perpendicular to the length direction.
Theae lengths can be placed on individual rolls and packaged so
that the user oan tear off individual sheetæ of appropriate aize
at the time of U6 e.
If it ia desired to incorporate slits or other types of
openings into the article, this can be done just prior to winding
the finished article material onto rewind roll 19, or when it is
unwound from 6aid roll for cutting and packaging,
Typically, the individual usAge sheets of article~ of
the lnvention are deslgned to provlde from about 1 to about 5
grams of fabric condltioning composltion per aheet, wlth the area
of the individual sheet~ being from about 130 sq. am. to about
970 sq. cm.
The article ia used by placing it in the dryer with up
~26775S
-34-
to about 5-7 lbs. of fabrics ~based on dry weight) and cotumbling
the article and the fabrics together during the drying cycle.
The invention is illu~trated by the following example.
EXAMPLE I
An article of the invention is made according to the
process of Figure 2.
The substrate is a nonwoven cloth made of rayon fibers
having an average length of about 4 cm. and a denier of about 3.
The fibers are bound together by an ethyl acrylate binder system,
the binder comprising about 30% to about 35% by weight of the
substrate. The ~ubstrate thicknes~ i5 O. 008 cm. and the
substrate weight is 21 grams per square meter. The 6ubstrate has
an absorbent capacity of 6 grams of water per gram of substrate.
The portion of fabric conditioning compo~ition which i8
applied uniformly to the obverse face of the substrate by coating
head 5 consists of 70% by weight sorbitan mono~tearate (SMS) and
30% by weight ditallowdimethylammonium methylsulfate (DTDMAMS),
and is applied to the ~ubstrate in an amount 80 as to produce
composition:sub~trate ratio of 0.97:1. The portion of
composition which i6 applied by the rotogravure roll is prepared
by mixing 100 parts of the above SMS/DTDMAMS composition in a
molten state with 11 part~ titanium dioxide and 1 part of
"Ben~olite L" clay ta montmorillonite alay purohased from
Southern Clay Produots) to form a composition consisting of 26.8
by weight DTDMAMS, 62.6% by weight SMS, 9.8% by welght titanium
~Trademark
~r,
1;,~
~Z67~;S
-35-
dioxide, and 0.8% clay. The clay thickens the mixture and also
provides pigmentation. This pigmented portion of composition is
printed onto the substrate (to which the unpigmented composition
has already been uniformly applied) in a decorative "clouds"
design produced by the recesses in the surface face of the
rotogravure roll. The printed-on design covers 36% of the
substrate area and the amount of pigmented composition which is
added by the print-on, raises the total fabric conditioning
composition:substrate ratio to 1.5:1, and the weight percent of
pigment (titanium dioxide plus clay) present in the total amount
of fabric conditioning composition present on the substrate area
defined by the printed design is 6.4%
In preparing the article according to the process of
Figure 2, metal rollers 3 and 3a are maintained at a temperature
of about 70 C, the compositions in coating head 5 and print pan
13 are maintained at a temperature of about 65 C. The pressure in
the soating head is maintained at about 350 g./sq. cm. The
distribution rolls 8, 8a and 8b are maintained at a temperature
of about 70 C and the cooling rolls 9 and 9a are maintained at a
temperature of about 13-C. The recesses in the rotogravure roll
12 a.e cellular, having a depth of about 0.02 cm. and a density
of about 140 cells per sq. cm. of reoes~ed Area. The temperature
of rotogravure roll 12 and impre~sion roll 11 i~ maintained at
about 80 C. Cooling rolls 17, 17a and 17b arc maintained at
about 1-C.
After cooling and rewinding, the printed substrate is
cut into individual 22.9 cm. by 27.9 cm. rectangular articles.
lZ67755
-36-
A series of six 12.7 cm. slits, approximately 2.5 cm. apart, are
cut into the articles in the lengthwise direction, the series of
slit6 being centered within the article (see U.S. Patent
3,944,694). The articles each contain about 2.1 grams of fabric
conditioning composition, and the composition:substrate ratio is
about 1.5:1. In these articles, 58% by weight of the fabric
conditioning composition is disposed upon 36% of the substrate,
and 42% by weight of the fabric conditioning composition is
disposed upon the remaining 64% of the 5 ubstrate area.
One of these articles is placed into an automatic
laundry dryer with five pounds (dry weight basis) of damp
clothes. The dryer is operated for 45 minutes at the normal heat
setting. The fabrics and article are then removed from the dyer
and it is observed that the pattern has disappeared from the
article. The fabrics are softer and exhibit less static cling
than fabrics which have been dried in a similar manner without
adding a fabric conditioning article to the dryer. Depending
upon conditions of usage, the pattern on the article may not
always completely disappear during use. In any event, however,
the pattern will exhibit a substantially different appearance
after usage than before usage, thereby providing an easy mean~ o~
distinguishing a used article ~rom one which has not been used.
