United States Patent (19) 11) 4,251,403

Rees
45) Feb. 17, 1981
(54) PROCESS FOR SIZING FILAMENTYARN 56 References Cited
UTILIZNG AN IMPROVED WARP SIZE
COMPOSITION OF PVAL, UREA AND U.S. PATENT DOCUMENTS
SACCHARDE 2,595,276 5/1952 Lowry .......................... 260/17.4 SG
(75) Inventor: Richard W. Rees, Wilmington, Del. OTHER PUBLICATIONS
Chem. Absts, vol. 71:51204t, Lubricating and Sizing
73) Assignee: E. I. Du Pont de Nemours and Agent for Glass Fiber, Golosova et al.
Company, Wilmington, Del. Chem. Absts., vol. 73:89097q, Size Mixture for Hydro
phobic Weaving Yarns, Yoshimura et al.
21 Appl. No.: 100,351 Chem. Absts. vol. 81:107718q, Paper Clear Coating
Materials, Sakato et al.
(22 Filed: Dec. 5, 1979 Primary Examiner-Edward M. Woodberry
57 ABSTRACT
Related U.S. Application Data An improved warp size for filament yarn is provided
63 Continuation of Ser. No. 901,851, May 1, 1978, aban
doned. consisting essentially of polyvinyl alcohol, urea, and
mono- and di-saccharides, such as sucrose, which when
applied to filament yarn from aqueous solution provides
51) Int. Cl. ................................................ C08L 5/00 excellent abrasion resistance, low shedding, freedom
52 U.S. C. ............................ 260/17.4 SG; 428/295; from skinning, and outstanding ease of removal.
428/395
58) Field of Search ................................. 260/17.4 SG 10 Claims, No Drawings
 1.
4,251,403
2
PROCESS FOR SIZING FILAMENT YARN
of urea, and (c) from about 5 to about 30% by weight of
UTILIZING AN IMPROVED WARP SIZE
saccharide selected from the group consisting of mono
and di-saccharides.
COMPOSITION OF PVAL, UREA AND Further provided according to the present invention
SACCHARIDE is the above composition in the form of an aqueous
solution having a solids content of from about 3 to about
This is a continuation, of application Ser. No. 25% by weight.
901,851, filed May 1, 1978 and now abandoned.
DETAILED DESCRIPTION OF THE
BACKGROUND OF THE INVENTION O INVENTION
1. Field Of The Invention Various mono- or di-saccharides (e.g., sucrose, sorbi
This invention relates to warp sizes and more specifi tol) were added to a PVA/urea blend and surprisingly
cally it relates to an improved warp size for filament it was found that in addition to suppressing the crystalli
yarns based upon polyvinyl alcohol. zation, adhesion to polyester surfaces was also im
2. Description Of The Prior Art 15 proved and solution viscosity was stabilized. The resul
Polyvinyl alcohol (PVA) has been tried, repeatedly tant three component sizing composition is clearly supe
as a warp size for polyester filament yarn but has been rior to the prior art sizes. Excellent performance is
rejected due to the undesirable quantity of "shed' that achieved by employing the improved warp size of the
accumulates on the loom. This "shed' consists of frag present invention on polyester filament yarn, resulting
ments of the size that are scraped off the individual 20 in excellent abrasion resistance, low shedding, freedom
yarns by the various areas of high abrasion encountered from skinning and outstanding ease of removal. In addi
in weaving, for example the reciprocating action of the tion, the present composition exhibits improved com
reed. As a consequence of this serious problem, PVA is patibility with tints, which are frequently used in fila
not used as a principle ingredient in polyester filament ment yarn slashing.
yarn sizing. 25 The polyvinyl alcohol employed in the composition
Although urea has been used in conjunction with of the present invention should have a degree of hydro
PVA in warp sizing of spun yarns for several years, this lysis of from about 88 to 100 mol % and should have a
combination is not an acceptable warp size for filament 4% aqueous solution viscosity in the range of from
yarns because of the excessive crystallization of urea on about 5 to about 50 mPas. Preferably the 4% solution
the surface of cast films, resulting in powdery shedding 30 viscosity is from about 10 to about 35 mPas.
and because of the poor viscosity stability in concen The polyvinyl alcohol can be either a homopolymer
trated solutions. or a copolymer. Copolymers can be obtained by alco
C. R. Williams and D. P. Donermeyer disclosed in holysis (hydrolysis saponification) of copolymers of
the American Dyestuff Reporter, June 3, 1968, the addi vinyl acetate with minor quantities of other comono
tion of sucrose to PVA in order to increase rate of 35 mer, such as acrylate esters, methacrylate esters, male
removal of warp size. ate esters and alpha-olefins. The mol % range of such
Nippon Gohsei disclosed in Japanese Patent Applica comonomer units is from 0 to about 12% in the PVA.
tion JA-134571, published on July 7, 1977 the addition The polyvinyl alcohol is employed in the amount of
of 0.5-5.0 weight percent of mono- or disaccharide, from about 40 to about 90% by weight of the cole posi
such as glucose, fructose, sucrose and maltose, to aque- 40 tion on a dry basis. Preferably polyvinyl alcohol should
ous PVA solutions thereby preventing size shedding, be present in the amount of from about 50 to about 75%.
fluffing and end-breakage of the warp during weaving. The urea component of the present invention is pres
The solids content of the solution was 5-11 weight ent in the amount of from about 5 to about 30%, prefer
percent. ably from about 10 to about 25% by weight.
United States Patent Application Ser. No. 640,782, 45 The third ingredient of the composition of the present
filed on Dec. 15, 1975, and now abandoned discloses invention is mono- or di-saccharide. These include for
adhesive compositions that are combinations of (1) pol example, sucrose, glucose, fructose, maltose, lactose,
yvinyl alcohol, (2) a crystalline solvent such as urea and invert sugar and sorbitol. A most preferred saccharide is
(3) a viscosity reducing diluent such as water, liquid SuCOSe,
polyhydric compounds such as glycols, etc., and op 50 The mono- and di-saccharides do not soften the film
tionally extenders, such as starch, clay, etc. These adhe or cause it to become tacky. Therefore, they are func
sives are disclosed to be suitable for cellulosic substrates tional in warp sizing when used in combination with
providing excellent ambient temperature water resis urea. They improve adhesion to polyester while glyc
tance while being fully repulpable in hot water. Appli erol or glycols only function as plasticizers. The solid
cation of such a combination of PVA, urea and poly 55 physical form of the saccharides is an advantage since
hydric alcohol to polyester filament yarns gives very the sizing composition can be supplied as a dry, free
soft, flexible films which tend to cause end-to-end, i.e., flowing blend which can be stored dry and dissolved
yarn-to-adjacent yarn adhesions. Abrasion resistance is only as needed.
only marginal to poor. The saccharides are present in the amount of from
60 about 5 to about 30%, preferably from about 10 to about
SUMMARY OF THE INVENTION 25% by weight.
According to the present invention there is provided For certain styles of yarn and fabric the PVA based
a composition consisting essentially of (a) from about 40 warp size of the present invention can also be used
to about 90% by weight of polyvinyl alcohol having a advantageously in combination with other aqueous
degree of hydrolysis of from about 88 to about 100 mol 65 sizes, such as acrylic polymers or polyester dispersions.
% and a solution viscosity of from about 5 to about 50 Of course, optionally other ingredients may also be
mPa.s measured as a 4% aqueous solution at a tempera included in the warp size of the present invention in
ture of 20 C., (b) from about 5 to about 30% by weight order to accomplish some special effect. Accordingly
 3
4,251,403
4.
for example, water soluble color may be added to size shedding was somewhat higher, and the abraded yarn
boxes to color-code yarns from specific section beams. was more open, and limper.
The warp sizing composition of the present invention
is applied to the filament yarn from an aqueous solution EXAMPLE 3
having a solids content of from about 3 to about 25 409.2 g of polyvinyl alcohol employed in Example 1,
weight percent, and preferably from about 5 to about 12 125.4 g of urea and 125.4 g of sucrose were dissolved in
weight percent. Well known slashing methods are suit 5340 g of water, producing a clear, 10.3% solids solu
able for applying the warp sizing to the filament yarn. tion. This was applied to texturized polyester yarn as in
The temperature of the size solution should be be previous examples and gave an add-on of 9.6%. The
tween 40 and 90° C. Either single or multiple size boxes 10 slashed yarn was found to be excellent in abrasion resis
may be used. After removal of excess size solution by tance.
passage between squeeze rolls, the sized yarn is dried by
contact with multiple drying cans heated to tempera EXAMPLE 4
tures of 100 to 125 C., split by stationary lease rods, 150g of "Syltint Blue' (a water-soluble dye solution,
and wound as a weaving beam. The slashing operation 15 available from Sylvan Chemical Corp.) tint was added
is conducted at speeds of 10 to 100 meters/min. Essen to 5000 g of the aqueous composition of Example 3. A
tial properties of the size include (a) absence of exces uniform blue color was obtained on the yarn, although
sive foaming in the size box, (b) no sticking of polymer
to the drying cans, (c) clean splitting at the lease bars operability was not as good as in Example 3 due to
without breakage of ends or filaments, and (d) easy 20 altered wetting characteristics. In the abrasion test, the
separation of the sized yarns when entering into the quantity of shedding was very light. Performance was
loom harness. judged to be very good on an overall basis.
Weaving may be performed with conventional shut EXAMPLES 5-10
tle looms, air-jet looms, rapier looms or shuttleless
weaving machines. Essential characteristics are (a) pro 25 Comparative tests were run by the methods detailed
duction of first-quality cloth, (b) loom efficiency of 90% above, on texturized polyester yarn. Size compositions
or greater, and (c) absence of loom fouling by powdery were applied from an aqueous solution having a solids
or paste-like deposits. content of 10% by weight. Operability in the slasher
During finishing, the size is removed by scouring was excellent in every case.
with detergent solutions and hot water. It is highly 30
desirable that the size should be completely removed
from the cloth, using water at moderate temperatures Compostn. (wt % Dry) Add-on
(50-80 C.), without the use of chemical additives such Example PVA Urea Sucrose wt % Abrasion Rating
as sodium hydroxide or carbonate. 5 62 19 19 9.0 Very good.
All these desired characteristics are obtained by the 35 6 62 16 22 8.5 Slightly more shed
than 5.
use of the compositions disclosed in this application. 7 62 22 6 8.7 Fair (filled dents).
The following examples are given for the purpose of 8 60 20 20 8.7 Excellent.
illustrating the present invention. All parts and percent 9 64 18 18 9.1 . Slightly inferior
ages are by weight unless otherwise specified. to 6.
40 10 70 15 15 9.4 Light shed but loose
EXAMPLE 1. filaments.
A solution of 750 g of polyvinyl alcohol (degree of
hydrolysis 99.0-99.8 mol %, 4% aqueous solution vis EXAMPLES 11-14
cosity at 20 C. 27 mPais), 225 g of urea, and 225 g of
sucrose in 4800 cm3 of water was prepared by heating 45 PVA of Example 1 was dissolved in water to produce
and stirring at 80 C. The viscous, 20% solids solution, an 8% by weight solution. Urea and saccharides were
was diluted with water to solids contents of 12.5, 11.0 added as shown below to give solution blends from
and 9.2% respectively, before being applied to 100 ends which films were cast on Mylar (R) polyester. The punc
of texturized polyester yarn, using a Callaway slasher ture and abrasion resistances of these films were com
operating at about 10 meters/minute. The solutions 50 pared by methods which have been shown to correlate
were clear, and did not foam or form skins in the size with weaving experience.
box. The slashed yarn produced, at add-on levels of
13.1, 12.0 and 8.8%, respectively, was stiff, compact
and well bonded. In abrasion tests, using a reciprocating Example PVA Urea Saccharide Puncture and Abrasion
reed tester at 1 cycle/second for 15 minutes, outstand 55 Control 10g - - Poor
ing freedom from shedding and filament breakage was 11 10g 3g Dextrose 3g Excellent
observed at the 13.1 and 12.0% add-on levels. There 12 10g 3g Lactose 3g Very good
was slightly more shedding at 8.8% add-on, but the 13 10g 3g Fructose 3g Excellent
14 10g 3g Maltose 3g Very good
shed was easily removed and did not fill any of the reed
dents.
EXAMPLE 2 Comparative Example A
Identical to Example 1 except that the proportions Polyvinyl alcohol of Example 1 was dry blended
were changed as follows: 706 g of polyvinyl alcohol, with urea to give a 70/30 uniform mixture and this was
282 g of urea and 212 g of sucrose. Add-on levels of 65 dissolved in water to give a 20 wt.% solids solution.
10.0, 9.3 and 8.2% were obtained on the texturized During a 4 week period of storage of this solution, the
polyester yarn. Results with the abrasion tester were viscosity was found to increase substantially and finally
similar to the results in Example 1, but the level of it became a gel.
 5
4,251,403
6
A 20% solution was also prepared from PVA/urea/- I claim:
sucrose (62/19/19). The viscosity was about 3000 mPa.s 1. A process for sizing filament yarn with a composi
and remained at this level after storage for 3 months. tion consisting essentially of (a) from about 40 to about
Comparative Example B 90% by weight, on a dry basis, of polyvinyl alcohol
having a degree of hydrolysis of from about 88 to about
PVA of Example 1/urea (70/30) was dissolved in 100 mol % and a solution viscosity of from about 5 to
water to give a 7.5 wt.% solution which was applied to about 50 mPa's measured as a 4% aqueous solution at a
3728 ends of texturized polyester yarn in a West Point temperature of 20° C., (b) from about 5 to about 30% by
slasher. Operation was good, and the size add-on was weight of urea, and (c) from about 5 to about 30% by
approximately 5%. Weaving of this yarn on a Sulzer 10 weight of saccharide selected from the group consisting
loom gave 91.7% efficiency, but excessive shedding of mono- and di-saccharides.
was observed. 2. The process of claim 1 wherein said polyvinyl
PVA of Example 1/urea/sucrose (62/19/19) was alcohol has a solution viscosity of from about 10 to
dissolved in water and was applied to 4040 ends of about 35 mPas.
texturized polyester yarn, the tints ("Chemurgy Blue' 15 3. The process of claim 2 wherein said polyvinyl
and "Chemurgy Yellow", available from Chemurgy alcohol is present in the amount of from about 50 to
Chemical Company) added to the size boxes in the about 75% by weight.
amount of about 3% by wt. of the size box contents. 4. The process of claim 3 wherein said saccharide is
Solids levels of about 9.5% were used. Satisfactory selected from the group consisting of sucrose, glucose,
operation was observed during slashing of 2000 yards. 20 fructose, maltose, lactose, and invert sugar.
Weaving tests in a Sulzer loom gave >85% efficiency 5. The process of claim 4 wherein said saccharide is
with low shedding and overall acceptable performance. present in the amount of from about 10 to about 25% by
Add-on was about 6.4%. weight.
Comparative Example C 6. The process of claim 5 wherein said saccharide is
25 SUCOSc.
10 g of polyvinyl alcohol of Example 1, 3 g of urea, 7. The process of claim 6 wherein the urea is present
and 1 g of diethylpropanediol were dissolved in 115 in the amount of from about 10 to about 25% by weight.
cm3 of water. Cast film had good adhesion to Mylar (R) 8. The process of claim 7 wherein a composition
polyester sheet, but was very soft. When applied to consisting essentially of about 60% by weight of polyvi
smooth polyester yarn at 70° C. abrasion resistance was 30 nyl alcohol, about 20% by weight of urea and about
fair. However, it was also applied to texturized polyes 20% by weight of sucrose is employed.
ter yarn and found to produce an undesirable quantity 9. The process of claims 1, 4, 7 or 8 wherein said
of shed when subjected to abrasion in the reciprocating composition is employed in the form of an aqueous
reed device. solution having a solids content of from about 3 to about
A similar solution, in which glycerol was substituted 35 25% by weight.
for the diethylpropanediol, was also applied to smooth 10. The process of claim 9 wherein said aqueous solu
polyester yarn and gave a flat yarn with some irregular tion has a solids content of from about 5 to about 12%
ities and fair abrasion resistance. This was not consid by weight.
ered sufficiently promising to test on texturized yarn. k is k it

45

50

55

65