This Report helps you to develop Hygroscopic Polyesters and also provided few patented technologies

1. 22.12.2014
Hygroscopic polyesters
PET is hygroscopic polyester, meaning that when it exposed to humid atmospheres, it will
absorb the moisture.
We can obtain hygroscopicity for PET by using the following Co-monomers
1. Polyethylene glycol (PEG) MW: 6000 to 20000 (up to 50 wt%)
2. Aromatic dicarboxylic acid having a metal sulfonate group (SIPA & DMSIP)
3. DEG
4. Silica-based inorganic particles
5. Graft polymerizing Acrylic polymers or meth-acrylic acid to polyester fiber
6. Cellulose acetate
7.
Application of Hygroscopic polyestercopolymer
Suitable for underwear, shirts, blouses, intermediate wear, sportswear, slacks, outer wear,
interlinings, curtains, wall paper, and furthermore, bed sheets, bedquilt covers, fillings, etc.
Test procedures
Test method for Degree of hygroscopic swelling
A polyester copolymer chip was dried in a vacuum at 130° C. for 12 hours, accurately weighed,
and put into a container filled with water. After 24 hours, the chip with water absorbed was
weighed, and the ratio of the chip weight after water absorption to the chip weight before
Water absorption was obtained from the following formula as the degree of hygroscopic
swelling.
Degree of hygroscopic swelling=Chip weight after water absorption/Chip weight before water
absorption
Determine the Moisture absorption and release parameter (ΔMR) of polyester copolymeror
fiber using it
In the case of a polymer, 1 g of a chip was cut into an about 2 mm cube to make a sample, and
in the case of a yarn, 1 to 3 g of a raw yarn or cloth was used as a sample. The absolute dry
weight of the sample was measured. The sample was allowed to stand in a thermo-hygrostat
(PR-2G produced by Tabai) at 20° C. and 65% RH or at 30. degree. C. and 90% RH for 24 hours,
and weighed. The coefficient of moisture absorption was obtained from the following formula:
Coefficient of moisture absorption (%) = (Weight after moisture absorption-Absolutely dry
weight)/Absolutely dry weight×100
From the coefficient of moisture absorption measured after treatment at 20° C. and 65% RH
and that at 30° C. and 90% RH (respectively expressed as MR1 and MR2), the moisture
absorption coefficient difference ΔMR (%)=MR2-MR1 was obtained. If the polyester copolymer
is higher in ΔMR, the hygroscopicity of the yarn can be more efficiently enhanced preferably.
So, the following criterion was used:

2. ΔMR≧18 . . . Good
12≦ΔMR < 18 . . . ok
ΔMR < 12 . . . Foor
Relevant Patents:
JP2006104379A
TEIJIN FIBERS LTD
2006-04-20 C08L 67/00
Title: POLYESTER COMPOSITION, ITS PREPARATION METHOD AND POLYESTER MOLDED
PRODUCT AND HYGROSCOPIC POLYESTER FIBER MADE OF THE SAME
Abstract: PROBLEMTO BE SOLVED: To provide a polyester composition excellent in color hue,
and a hygroscopic fiber and a molded product made of the same.
SOLUTION: The polyester composition comprises an aromatic polyester copolymer as the main
constituent and contains 0.1-10 mass ppm orthochromatic agent, wherein the aromatic
polyester copolymer comprises ethylene glycol or tetramethylene glycol as a main glycol
component and is obtained through copolymerization of polyethylene glycol and/or its
derivative. In the polyester composition, the color a* value and the color b* value in an L*a*b*
color systemfall within the range of -9 to 0 and -8 to 6, respectively, after a heat-treatment
conducted at 130°C for 2 hr, the maximum absorption wavelength in the visible absorption
spectrum falls within the range of 540-600 nm, and relations (1)-(4): [wherein A400, A500, A600
and A700 are the absorbance at 400nm, 500nm, 600nm and 700nm, respectively, in the visible
absorption spectrum; and Amax is the absorbance at the maximum absorption wavelength in the
visible absorption spectrum] are satisfied.
US5698331A
TORAY INDUSTRIES
1997-12-16
C08G 63/668
Title: Hygroscopic polyester copolymer, and a hygroscopic fiber made therefrom
Abstract: The present specification discloses a hygroscopic polyester copolymer with a
hydrophilic compound copolymerized, containing a cross-linking agent and controlled in
moisture absorbing and releasing property, and a fiber using the polyester copolymer. The fiber
can be used as a comfortable material for underwear, sports wear, interlinings, etc. as highly
hygroscopic woven and knitted fabrics, etc. of high quality
JP62267352A
ASAHI CHEMICAL IND
1987-11-20
Title: HYGROSCOPIC POLYESTER COMPOSITION

3. Abstract: PURPOSE: To obtain a novel polyester composition of high hygroscopicity, suitable for
sports wears, beddings, towels, etc., by incorporating, during the polyester production process,
that is, prior to the forming, a specified proportion of a polyalkylne glycol of specific mol.wt.
CONSTITUTION: The objective composition, that is, a modified polyester can be obtained by
incorporating (A) 50 to 70 (pref. 55 to 65)wt % of a polyalkylene glycol with a number-average
mol.wt. =6,000 (pref. 6,000 to 20,000) (e.g. a block copolymer from polyethylene glycol and
polypropylene glycol, a random copolymer from ethylene oxide and propylene oxide) during
the esterification or polymerization, or at the completion of the ester interchange, for a
polyester containing, in the recurring units, ethylene terephthalate chain or butylene
terephthalate chain.
JP2002363824A
TORAY INDUSTRIES
2002-12-18; C08K 3/36
Title: POLYESTER FIBER HAVING EXCELLENT HYGROSCOPICITY
Abstract: PROBLEMTO BE SOLVED: To obtain a polyester fiber having an excellent productivity
and high hygroscopicity, and capable of providing a woven or knitted product or the like usable
as a comfortable material such as an underwear, a sport wear and a lining.
SOLUTION: This polyester fiber having the excellent hygroscopicity and productivity contains
both of silica-based inorganic particles and inorganic particles having surface potentials
opposing to those of the silica-based particles
JP2221413A
TEIJIN LTD
1990-09-04
Title: HYGROSCOPIC POLYESTER FIBER
Abstract: PURPOSE: To obtain the subject fiber having permanent hygroscopicity and unique
feeling by dispersing and mixing a specified amount of cellulose acetate in a terephthalic acid-
based polyester. CONSTITUTION: In a polyester (e.g. polyethylene terephthalate or
polybutylene terephthalate) containing terephthalic acid as the main acid component, 1-30
weight percent, preferably 10-15 weight percent cellulose acetate (preferably 52-63 percent
degree of acetylation) is dispersed and mixed to obtain the objective fiber.
JP4361616A
Toray Ind.
1992-12-15
Title: CORE-SHEATH TYPE CONJUGATE FIBER EXCELLENT IN HYGROSCOPICITY

4. Abstract: PURPOSE: To obtain the subject fiber, useful as inners, sportswears, etc., and
excellent in high-level processability by using a specific thermoplastic resin as a core part and a
fiber-forming polyester resin as a sheath part and specifying the ratio of the core part.
CONSTITUTION: The objective fiber is obtained by using (A) a thermoplastic resin of a polyether
ester resin (preferably a block copolymer prepared by polycondensing a polyamide-forming
component composed of caprolactam, etc., adipic acid, etc., and a polyether ester-forming
component compose of polyethylene glycol) as a core part and (B) a fiber-forming polyester
resin such as polyethylene terephthalate as a sheath part. The ratio of the core part is 5-30wt.%
based on the whole weight of the conjugate fiber.
JP2002053743A
TORAY INDUSTRIES
2002-02-19; C08L 67/02
Title: HYGROSCOPIC POLYESTER COMPOSITION, SYNTHETIC FIBER USING THIS COMPOSITION,
AND PREPARATIVE PROCESS THEREOF
Abstract: PROBLEMTO BE SOLVED: To provide a hygroscopic polyester composition particularly
suitable for synthetic fibers which is comfortable to wear because of the excellent
hygroscopicity.
SOLUTION: The hygroscopic polyester composition comprises 80-99 wt.% of (A) a polyalkylene
terephthalate-based polyester which is copolymerized with 1-10 mole% of an aromatic
dicarboxylic acid having a metal sulfonate group, and 1-20 wt.% of (B) a hygroscopic viscosity-
reducing agent which has a melt viscosity at 280°C and 1000 sec-1 of 20-2, 000 poise and a
hygroscopic parameter (ΔMR) of 10-100%
JP9241925A
Nippon Ester Co Ltd
1997-09-16
Title: HYGROSCOPIC POLYESTER FIBER
Abstract: Source: JP9241925A [EN] PROBLEMTO BE SOLVED: To obtain a hygroscopic polyester
fiber, producible with good yarn manufacturing properties and having excellent hygroscopicity
and light resistance. SOLUTION: This hygroscopic polyester fiber comprises a polyester,
containing 3-50wt.% polyalkylene glycol having 2000-20000 average molecular weight in a
polyalkylene terephthalate, cerium oxide and talc or cesium oxide and silica and further 0.05-
10wt.% particles having the surface coated with amorphous silica and 0.1-3.0μm average
particle diameter therein

5. JP6123011A
ASAHI CHEMICAL IND
1994-05-06: C08G 63/672
Title: HYGROSCOPIC POLYESTER FIBER
Abstract: PURPOSE: To obtain the subject fiber containing a three-dimensional random
copolymer component and a block polyetherester component in specified amounts,
respectively, further containing metal ions, and excellent in washing resistance, hygroscopicity
and heat resistance.
CONSTITUTION: The objective fiber contains (A) a three-dimensional random copolymer
component composed from (i) alkylene terephthalate units of formula I (R1 is 2-4C alkylene), (ii)
alkylene sulfoisophthalate units of formula II (M is metal ion), and (iii) polyoxyalkylene glycol
units each having an average mol.wt. of 300-20000 and (B) a blocked polyetherester
component of formula III (R2 is the same as R1 (a) is 3-100; (b) is 1-10) so as to satisfy conditions
comprising: component (i) (wt.%) ≥60 and 1≤, component (ii) ≤10 and 0.2≤, component
(iii)/component (ii) ≤5.0 and 0.5≤, component B/component (ii) ≤4.0. The M having a value of
≥1.5 is contained as the metal salts of the compounds of formula II and III in an amount of
0.1g/kg of the weight of the fiber. The value is obtained by dividing the charge number of the
metal ion by the radius (Å) of the metal ion
JP3179024A
KURARAY CO
1991-08-05D01F 6/86
Title: COPOLYESTER, DIOL COMPOUND USED THEREFOR AND FIBER COMPRISING SAME
Abstract: PURPOSE: To provide a copolyester which can give a high-strength fiber having high
surface wettability, hygroscopicity, etc., by constituting it from aromatic dicarboxylic acid units,
alkylene glycol units and a specified amount of polyoxyalkylene side chain-containing diol
compound units.
CONSTITUTION: Aromatic dicarboxylic acid units (e.g. terephthalic acid units), alkylene glycol
units (e.g. ethylene glycol units) and polyoxyalkylene side chain- containing diol compound
units of formula I [wherein R1 and R4 are each a hydrocarbon group which may be substituted;
R2 and R5 are each 2-4 C alkylene; R3 is H or a hydrocarbon group; Y1 and Y2 are each an organic
group; m1 and m2 are each 1, 2 or 3; and (a1×m1)+(a2×m2) is 12-500] (e.g. formula II) in an
amount to give the content of units of formula I of 1-60wt.% to produce a copolyester of an
intrinsic viscosity of 0.4-1.5dl/g
CN102220657A
CHINESE TEXTILE ACADEMY
2011-10-19

6. D01F 6/92
Title: Hygroscopic polyester staple fiber and preparation method thereof
Abstract: The invention relates to a hygroscopic polyester staple fiber and a preparation
method thereof. The hygroscopic polyester staple fiber is obtained by the steps of beating and
blending of inorganic powder and polyester monomers, polycondensation reaction, spinning
and post-treatment. The polyester monomers are terephthalic acid, binary fatty alcohol and
poly binary fatty alcohol. With a fiber number ranging from 0.89-1.33dtex, the fiber obtained
has good hygroscopicity and pilling resisting performance
JP2001234433A
NIPPON ESTER CO LTD
2001-08-31 D01F 8/14
Title: HYGROSCOPIC POLYESTER FIBER
Abstract: PROBLEMTO BE SOLVED: To provide a hygroscopic polyester fiber excellent in
hygroscopic performance and also possessing practical strength, and capable of exhibiting a
soft feeling by being subjected to caustic reduction treatment.
SOLUTION: This hygroscopic polyester fiber is a conjugated fiber made of two components A
and B both composed mainly of polyethylene terephthalate. The component A substantially
comprises a polyethylene terephthalate composed of ≥90% of ethylene terephthalate repeating
unit, the component B comprises a specific compound, and the weight ratio of the component
A to the component B is (10/90) to (60/40). The component B is exposed on the surface of the
fiber in a proportion of ≥15% of the surface area of the fiber.
The component B is polyethylene glycol, molecular weight is over 18,000
JP9157956A
Nippon ester co Ltd
2004-10-06
Title: HYGROSCOPIC POLYESTER CONJUGATE FIBER
Abstract: Source: PROBLEMTO BE SOLVED: To obtain a hygroscopic polyester hollow conjugate
fiber not causing sheath cracking in alkali weight-loss treatment and a dyeing process, by
arranging polyesters different in moisture absorption at a core part and a sheath part and
subjecting to conjugate spinning. SOLUTION: This hygroscopic polyester conjugate fiber
comprises a core component consisting of a copolyester composed of a polyethylene glycol and
sodium salt of 5-sulfoisophthalic acid as copolymerization components and ethylene

7. terephthalate as a main repeating unit and a sheath component having each moisture
absorption at 34°C at 90%RH satisfying relationship 10≥A≥B and 5≥B≥1 (A is moisture
absorption of the core component and B is moisture absorption of the sheath component) and
a weight ratio of both the core and the sheath components of 20/80 to 70/30 and is obtained
by melt spinning through a spinneret for concentric circular hollow conjugate spinning and has
a hollow part having 2-6% hollow ratio continuous in the longer direction in the interior of the
fiber.
JP11181676A
Toray Industries
1999-07-06
Title: HYGROSCOPIC TEXTILE STRUCTURAL PRODUCT AND ITS PRODUCTION
Abstract: Source: PROBLEMTO BE SOLVED: To obtain the subject product simultaneously
bearing excellent hygroscopicity, durability and color fastness by providing an acidic group-
contg. polyester-based textile structural product with a carboxylic acid salt-type amphoteric
compound alogn with carrying out dyeing. SOLUTION: This hygroscopic textile structural
product is obtained by immersion treatment at 80-130°C of a textile structural product such as
yarns or a fabric comprising acidic group-contg. polyester fiber such as polyethylene
terephthalate copolymerized with 1.5-7 (pref. 2-5) mol.% of 5-sodium sulfoisophthalate and/or
5-potassium sulfoisophthalate in a treatment liquid containing a dye and a carboxylic acid salt-
type amphoteric compound such as lauryl dimethylbetaine or coconut oil fatty acid
amidopropylbetaine to effect applying the amphoteric compound at 0.1-5 wt.% to the textile
structural product.
JP2000054262A
Teijin Ltd
2000-02-22
Title: [EN] HYGROSCOPIC POLYESTER FIBER
Abstract: PROBLEMTO BE SOLVED: To produce hygroscopic polyester fibers excellent in
hygroscopictiy and laundering resistance by forming fibers of a polyester compounded with a
specific polyalkylene oxide and then graft-polymerizing a polyalkylene glycol derivation on the
surfaces of the fibers. SOLUTION: The hygroscopic polyester fibers are produced by spinning
poly(ethylene terephthalate) compounded with 0.1-15 weight percent polyalkylene oxide (e.g.
polyethylene oxide) having =100,000 (pref. 500,000-4,000,000) weight average molecular
weight to form fibers, forming cloth with the fibers and then graft- polymerizing a polyalkylene
glycol derivative (e.g. a polyalkylene glycol diacrylate and/or a polyalkylene glycol
dimethacrylate) having 100,000 (pref. 250-1,500) weight average molecular weight on the
surfaces of the cloth.

8. JP2003306833A
Nippon Polyester Co Ltd
2003 -10-31
Title: [EN] HYGROSCOPIC POLYESTER FIBER
Abstract: PROBLEMTO BE SOLVED: To provide a fiber exhibiting a soft touch feeling and having
excellent hygroscopicity by regulating the alkali weight reduction rate of the fiber within the
range without actual problems and carrying out a uniform weight reduction
processing.SOLUTION: The hygroscopic polyester fiber comprises a polyalkylene terephthalate
containing 5-30 mass% of a polyether compound or a polyether compound derivative having
=4,000 average molecular weight and an aromatic dicarboxylic acid component having at least
=1 phenolic hydroxy groups is copolymerized in an amount of 0.5-5 mol% based on the whole
acid components.
JP2004084087A
Nippon Ester Co Ltd
2004-03-18
Title: HYGROSCOPIC POLYESTER CONJUGATE FIBER
Abstract: PROBLEMTO BE SOLVED: To obtain a conjugate fiber which develops a soft feeling by
carrying out uniform weight reduction processing and has excellent hygroscopicity.SOLUTION:
The hygroscopic polyester conjugate fiber is a core-sheath type polyester conjugate fiber
comprising a polyalkylene terephthalate as a core component which contains 10-30 mass % of a
polyether compound or a polyether compound derivative having 4,000-15,000 average
molecular weight and is copolymerized with 0.5-5 mol % based on the total acid components of
a sulfonate group-containing aromatic dicarboxylic acid and/or a phenolic hydroxy group-
containing aromatic dicarboxylic acid and 0.5-5 mol % based on the total acid components of a
dimer acid and has =5% swelling ratio and a polyester as a sheath component composed of an
alkylene terephthalate as a main repeating unit. The hygroscopic polyester conjugate fiber has
=2.5 mass % coefficient of moisture absorption of the conjugate fiber (in an atmosphere at 34
Degrees Centigrade at humidity of 90% RH).