FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL
Specification
(See Section 10; rule 13)
A POLYESTER RESIN COMPOSITION FOR MANUFACTURING POLYESTER STAPLE FIBRE OR FILAMENT YARN WITH HIGH
SHRINKAGE PROPERTIES
FUTURA POLYESTERS LIMITED
an Indian Company,
of Paragon Condominium, 3rd floor, Pandurang Budhakar Marg, Mumbai 400 013, Maharashtra , India
THE FOLLOWING SPECIFICATION DESCRIBES THE INVENTION

This invention relates to a new polyester resin composition for manufacturing polyester staple fibre or filament yarn with high shrinkage properties.
Background
Polyesters, particularly Polyethylene Terephthalate (PET), are now produced world-wide and are widely used in the manufacture of fibres for textiles and other applications like non-wovens. Because fibers produced from polyester have a number of outstanding characteristics: excellent dimensional stability and sturdiness, a high degree of crease resistance, good bulk elasticity, and warm handle, the fibers made from polyester have found a wide variety of applications, especially in the textile field. While PET has many desirable properties which makes it suitable for manufacturing textle fibres, there is a continuing need for new modified polyester fibres with improved properties that are different from normal PET fibres thereby opening new areas of application. Polyester fiber with high shrinkage is one such desirably modified fiber.
In the prior art, Polyester fibers are produced having a reduced final shrinkage. Typical, polyester fiber shrinkage is about 7% when subjected to dry heat at I8O0C for 20 minutes. However, in certain applications, it is desirable for the polyester fibers to have a high shrinkage of about 70% , like for example for fabrics made from polyester fibers which are used for automotive upholstery. Also it is sometimes desirable to blend polyester fibers having low shrinkage with polyester fibers having high shrinkage to produce a resulting product in which there is crimp retention and high bulk is developed along with a soft

handle like in carpet yarns. High shrinkage fibres also find applications, as an alternative and substitute for Acrylic fibre, in the fields of Apparel comprising sweaters, socks, sportswear, circular knit wears etc. and in the fields of Home Furnishings like blankets, rugs, artificial furs etc. As non-wovens they have usage in interlinings, filtration media etc. This substitution is cost effective in relation to acrylic fiber user.
Shrinkage of polyester fiber can be altered by both chemical modification of the polymer and by modifying the process during fiber manufacture.
Prior Art
Modified PET fibers with high shrinkage properties are known and the
modifications are mainly by different additives while making the PET.
Isophthalic acid, dimethyl-2,6-naphthalenedicarboxylate (NDC),
polyethylenenaphthalate (PEN) are some of the modifiers which find application in these areas.
KR 850001069B describes a method for producing cation dyeable polyester fiber with high shrinkage characteristics. Here the high shrinkage modifiers are selected from dicarboxylic acids like phthalic acid, phthalic anhydride or isophthalic acid.
Again, KR 93001133 8B describes a polyester fiber of high strength with dry-heat high shrinkage above 35% produced by adding modifiers like isophthalic acid or dimethylisophthalate and 2,2-bis(4(2-hydroxyethoxy) phenol)propane.

KR 940007687B also describes a new polyester based fiber with enhanced shrinkage properties.
WO/1998/000591 deals with polyester fibers containing naphthalate units in the range of 10 to 90 mole percent of the total aromatic ester units in the polyester. PET blended with PEN has also been suggested as an alternative method of incorporating naphthalateunits.-
KR 20020008899 provides a polyester based orientd film with excellent heat-shrinkage property which comprises poly trimethylene terephthalate (PTT), PET and glycol modified copolyester (PETG) .
KR 20020085315 gives a method for producing high shrinkage polyester fiber by making use of a copolyester obtained by using di-[beta]-hydroxy ethylene phthalate as an acid modifier.
US 20060008644 describes fabrics of mixed polyester ratio bi-component fibers comprising a PET/PTT mixture between the ratios of 55/45 and 75/25 by weight and the two components of the bi-component have different shrinkage characteristics.
US 5223317 describes texturised carpets and rugs made from fiber blends of low shrinkage and high shrinkage polyester fibers the high shrinkage fibers being fibers made from the copolymer of poly(ethylene terephthalate) and the

second component selected from the group consisting of polyethylene gycol, diethylene glycol and isophthalic acid containing from about 2 to about 10 percent by weight of the second component.
US 4826949 discloses high shrinkage polyester fibers having good strength and uniform dyeability along with a method of producing the high shrinkage polyester fibers, by drawing a feeder yarn having a birefringence of at least 0.0175 at ambient temperature and carefully controlled draw ratios.
The present invention deals with production of high shrinkage textile fiber, with boiling water shrinkage (BWS) upto 50%, by chemical modification of the polyester resin and fiber processing.
Description of the Invention
BWS of the fiber is increased by trials in the pilot plant as well as in the manufacturing plant both by chemical modification of the polymer as well as by modifying the process during the fiber manufacture. In the chemical modification the PET resin is modified by alloying it with Polytrimethylene Terephthalate (PIT) at different proportions and optimizing the level which gives the higher BWS with out affecting the other essential fiber properties. Other modifiers like Isophthalic Acid (IPA) and 2-Methyl-l,3 Propane Diol (MP Diol) were also tried to evaluate the BWS properties. Details of the studies are given in the following examples.

Example 1 - MP Diol as the modifier
Normal textile grade PET of 0.65 is either modified with MP Diol while making the PET or the PET is blended with mastef batch chips of MP Diol ( 8 % MP Diol in PET) at the required proportion such that the MP Diol is available in the blended chips at percentages ranging between 3 an 6. The blended chips are converted to fiber by processing through the pilot spinning and drawing units. The resulting drawn fiber is evaluated for its BWS and the results are given in Table - 1.
TABLE - 1: BWS of MP Diol Modified Fibre

ISerial Rs&u& Dravfa Fibre Properties
No. Composition Denier (d) 1% Elongation Tenacity,
g/d % BWS
1. 100% PET 2.10 29.81 4.45 ! 11.8
2. PET + 3% MP Diol 2.05 31.05 4.37 15.2
3- PET + 4% MP Diol 1.63 27.35 4.99 16.1
4. PET + 4% MP Diol (as master batch) 1.8 32.7 4.47 16.3
5. PET + 6% MP Diol (as master batch) 1.74 36.81 4.11 22.13

With MP Diol as a modifier > 15 % BWS is obtained using the modifier as such or as a master batch in PET chips.
Example 2 - PDO or PTT as the modifier
Example 1 is repeated by replacing MP Diol with PTT or PDO as the modifier. The PET is modified either by adding PDO while making the PET or modified PTT chips are separately made by reacting PTA and PDO. The results of the drawn fibre are given in Table - II.
TABLE - II: BWS of PET Fibres Modified with PTT (Pilot Plant Studies)

Serial Resin Drawn Fibre Properties
No. Composition Denier (d) % Elongation Tenacity,
g/d % BWS
1. 100% PET 1.35 35.99 4.33 13.13
2. PET + 10 % PTT 1.62 19.7 6.02 16.5
3. PET + 15 % PTT 1.61 51.12 3.98 24.93
i
i
4. PET + 20 % PTT 1.77 46.91 3.88 32.6
Increasing PTT % in PET gives increased % BWS without affecting the other drawn fiber properties.

Example 3 - PDO or PTT as modifier along with IPA modified CoPET
Example 2 is repeated wherein instead of PET, CoPET containing 5 to 10 % IPA is used for the study. Results of the drawn fiber are given in Table - III.
TABLE - III: BWS of PET Fibres Modified with PTT along with IPA Modified CoPET

Serial Resin
Composition Drawn Fibre Properties
No.
Denier (d) % Elongation Tenacity, g/d % BWS
1. 100 % CoPET 1.59 39.2 4.88 16.1
2. 90% CoPET + 10% PTT 1.68 32.0 4.80 21.6
3. 80 % CoPET + 20 % PTT 1.70 29.1 4.77 31.4
4. 70 % CoPET 1.62 + 30 % PTT 34.4 5.07 44.9
5. 60 % CoPET + 40 % PTT 1.57 36.7 4.42 54.3
%BWS increases with increase of PTT % in the presence of CoPET. When compared to the resin modifications comprising PET with MPDiol (refer Example 1) or PET with PTT (refer Example 2), the resin composition comprising CoPET with PTT gives higher %BWS in the drawn fiber samples.

Similar results were obtained with colored fibers when normal PET or CoPET was used in association with PTT.
Example 4 - Example 2 is repeated in the production plant, instead of the pilot plant, and the results are given in Table - IV:
TABLE - IV: BWS of PET Fibers Modified with PTT (Production Plant
Studies)

Serial Resin Composition Drawn Fibre Properties
No.
Denier (d) % Elongation Tenacity,
g/d % BWS
1. 100% PET 2.78 51.80 4.13 12.89
2. PET + 12 % CoPET 2.75 53.00 4.00 31.35
3. PET + 15 % CoPET 2.76 53.62 3.94 36.36
4. PET + 20 % CoPET 2.74 50.33 4.03 44.80
e above sti tidies the Draw Line process c conditions are: Draw Ratios 4. 15
and 1.02, 64°C and Relaxation Drier 70°C.
As seen in the Pilot Plant studies increasing PTT % in PET gives increased % BWS to a higher level than obtained in pilot plant studies without affecting the other drawn fiber properties.

The main feature of the invention is a fiber having high shrinkage made from a resin which is a blend of PET and PTT where the PTT content is between 5 to 30%, preferably 10 to 25% and still preferably 12 to 20%, and wherein the first draw ratio lies between 4.00 and 4.2 and in the second draw ratio lies between 0.98 and 1.11 , the draw bath temperature being below 70 degrees C and the temperature at the time of crimping and relaxation drying being maintained below 80 degrees C.
While considerable emphasis has been placed herein on the specific resin composition and processes for making it by the preferred embodiment, it will be appreciated that many alterations can be made and that many modifications can be made in the preferred embodiment without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.
Dated this 3rd day of June 2009.
Mohan foewan Of RK Dewan&Co Applicants' Patent Attorneys