Polyester fiber

A fiber or filament comprising a polyester copolymerized with 2 to 20 mole % of a compound having a specific structure, which has one or two ester-forming functional groups. The polyester fiber or filament has a low birefringence and excellent dyeability and deep color development. The polyester fiber or filament is provided, when drawn under selected conditions, with not only high shrinkage ratio but also high shrinking stress, and has excellent lightfastness, thereby being useful while replacing conventional highly shrinkable fibers.

This application is a 371 of PCT/JP94/01242 filed Jul. 28, 1994. 
BACKGROUND OF THE INVENTION 
1. Technical Field 
The present invention relates to polyester fibers or filaments having 
improved properties in dyeability, deep color dyeability and 
lightfastness. The present invention further relates to composite fibers 
comprising the polyester constituting the above polyester fibers as a 
component, mixed filament yarns with differently shrinkable filaments or 
sheath-core textured yarns comprising the above polyester filaments as a 
component, and blended spun yarns comprising the above polyester staple 
fibers as a component. 
2. Background Art 
Polyester fibers represented by polyethylene terephthalate fibers have been 
used in a wide range of applications because of their superior 
characteristics. However, the fibers have disadvantages in color 
brightness, color depth particularly in deep black tone, and color 
development as compared to natural fibers, such as wool and silk, and 
semi-synthetic fibers such as rayon and acetate fibers. 
These disadvantages are caused, generally, by the fact that polyester 
fibers are dyed with disperse dyes which tend to give an insufficient 
brightness to the dyed articles, and that polyester fibers have a higher 
refractive index in a direction perpendicular to the fiber axis of 1.7 as 
compared to other fibers, which increases light reflectivity on the fiber 
surface, thereby increasing the intensity of white light reelection and 
scattering from the surface of fabrics comprising polyester fibers. 
To improve these disadvantages, many proposals for introducing dyeable 
sites for bright color dyes such as cationic dyes and acidic dyes into 
polyester fibers have been offered. These modifications have improved the 
dyed fabrics in color brightness, but achieved no substantial success in 
reducing the white light reflection and scattering and in improving color 
depth due to the high refractive index of the fibers. 
Japanese Patent Publication No. 42938/1992 proposes covering the surface of 
polyester fibers with a compound having a low refractive index, to achieve 
deep color dyeability. The publication mentions as examples of this type 
of compound organic fluorine and organosilicon compounds. 
Japanese Patent Publication Nos. 20304/1987 and 28229/1987 propose a method 
which comprises forming, on the surface of polyester fibers, fine 
projections and recesses having a pitch smaller than light wave length, 
thereby suppressing reflection and scattering of light on the fiber 
surface. 
However, with the fibers covered with a low refractive index compound, the 
covering film has poor durability against dry cleaning. Besides, the 
covered fibers, if they have achieved a sufficient deep color dyeability 
at all, give dyed articles having the new drawbacks of poor hand, 
colorfastness and lightfastness. 
The fibers with a very minutely toughened surface obtained by the above 
method suffer a damage to the toughened surface during post-processing, 
which reduces the effect of suppressing reflection and scattering of light 
on the fiber surface. Besides, fabrics made from this type of fibers tend 
to have a poor appearance due to wear when they are worn. 
One of the modifications of polyester fibers is highly shrinkable fibers, 
which are used for the following applications: (1) they are combined with 
less shrinkable fibers, and fabrics made therefrom are heat treated to 
achieve a bulky hand created by the difference in the fiber length; (2) 
the highly shrinkable fibers with a large fineness are combined with less 
shrinkable fibers with a small fineness, and fabrics made therefrom are 
heat treated to produce fiber length difference, whereby the fine fibers 
positioned on the fabric surface produce a gentle surface touch and the 
coarse fibers positioned in the fabric core produces good HARI (anti-drape 
stiffness) and KOSHI (stiffness); (3) the highly shrinkable fibers are 
used as ground yarns of pile knit or pile fabrics, thereby increasing the 
density of loops or fluffs; (4) a highly shrinkable polymer is used as a 
component of composite fibers, which will become latent crimpable fibers; 
and (5) the highly shrinkable fibers are used upon integral molding and 
three-dimensional molding. 
The highly shrinkable fibers have been prepared by modifying, upon 
polymerization for the raw material polyester, its acid component by 
polymerizing isophthalic acid with terephthalic acid. This is considered 
to be because that this process of modifying the acid component is most 
advantageous in conducting separation and recovery of ethylene glycol 
component in the polymerization process. However, this acid component 
modifying process, requiring a high copolymerization ratio, has the 
disadvantage of deteriorating superior characteristics inherent to 
polyester. 
Such being the case, not only the modification of acid component but also 
that of glycol component has been practiced in recent years. Among 
products obtained by the above processes, most common polyesters are those 
copolymerized with an alkylene oxide adduct of bisphenol A and those 
copolymerized with isophthalic acid and an alkylene oxide adduct of 
bisphenol A. These polyesters exhibit higher shrinkability with smaller 
copolymerization ratio as compared to those with modified acid component 
alone. Accordingly, this method is effective in obtaining high 
shrinkability and high shrinking stress while maintaining good properties 
inherent to polyester. 
However, polyesters copolymerized with an alkylene oxide adduct of 
bisphenol A have the disadvantages of very poor lightfastness and 
colorfastness. 
Another method for obtaining highly shrinkable polyester fibers comprises 
heat drawing polyester fibers at a low temperature, thereby decreasing the 
degree of crystallization of the polyester. This method can surely produce 
highly shrinkable polyester fibers, which, however, have low heat 
shrinking stress because of reduction in stress during dry heating. 
Consequently, the highly shrinkable effect cannot be exhibited in woven or 
knit fabrics utilizing mixed filament yarns combining less shrinkable 
fibers with such highly shrinkable fibers. 
The present inventors have made an intensive study to obtain a fiber having 
excellent dyeability and deep color dyeability, as well as high 
shrinkability and shrinking stress. As a result, it was found that 
polyesters copolymerized with a compound having a specific chemical 
structure in a specific amount can provide fibers having sufficient 
dyeability, deep color dyeability and shrinking characteristics. 
Polyesters copolymerized with the compound with the specific chemical 
structure in an amount of 50-100 mole % are disclosed in U.S. DEFENSIVE 
PUBLICATION T896033, but the polyester have been difficult to convert into 
fibers. 
The present invention is based on the finding that copolyesters polymerized 
with the compound with a specific chemical structure in a specific amount 
are convertible into fibers, which have not only sufficient dyeability, 
deep color dyeability, high shrinkability and shrinking stress 
characteristics, but also superior lightfastness and colorfastness. 
It is an object of the present invention to provide a polyester fiber or 
filament having not only excellent dyeability, deep color dyeability, high 
shrinkability and shrinking stress characteristics, but also excellent 
lightfastness and colorfastness. 
Another object of the present invention is to provide a mixed filament yarn 
or sheath-core textured yarn comprising this polyester filament. 
A further object of the present invention is to provide a blended spun yarn 
comprising as one component staple fibers comprising a polyester 
constituting the above polyester fiber. 
A still further object of the present invention is to provide a composite 
fiber comprising as a component the polyester constituting the above 
polyester fiber. 
DISCLOSURE OF THE INVENTION 
The present invention provides a polyester fiber (hereinafter referred to 
as "PES fiber (II)" or "PES filament (II)") comprising a polyester 
(hereinafter referred to as PES (I)) containing 2 to 20 mole % of 
copolymerization component of a compound represented by the following 
structural formula (1) 
##STR1## 
wherein R.sub.1 through R.sub.10 each represents a group selected from the 
group consisting of ester-forming functional groups, hydrogen atom and 
alkyl groups, one or two of R.sub.1 through R.sub.10 being ester-forming 
functional groups, x is 0 or 1, and y is an integer satisfying the 
following condition. 
EQU 1.ltoreq.x+y.ltoreq.3 
The present invention further provides a composite fiber comprising PES 
(I). 
The present invention still further provides a mixed filament yarn with 
differently shrinkable filaments comprising the PES filament (II). 
The present invention still further provides a sheath-core textured yarn 
comprising the PES filament (II). 
The present invention still further provides a blended spun yarn comprising 
staple fibers comprising PES (I).

BEST MODE FOR CARRYING OUT THE INVENTION 
In the compound represented by the structural formula (1) and contained in 
PES (I) constituting the PES fiber (II), examples of the ester-forming 
functional groups used are hydroxyl group, hydroxyalkyl groups, carboxyl 
group and ester-forming derivatives thereof. There is no limitation to the 
type of alkyl groups constituting the hydroxyalkyl groups, but they are 
preferably alkyl groups having 1 to 4 carbon atoms, such as hydroxymethyl, 
hydroxyethyl, hydroxypropyl and hydroxybutyl, including branched alkyl 
groups. Preferred examples of ester-forming derivatives of carboxyl group 
are carboxyalkyl groups with the alkyl having 1 to 4 carbon atoms, such as 
carboxymethyl, carboxyethyl, carboxypropyl and carboxybutyl. 
It is necessary that the compound contain one or two ester-forming 
functional groups. The compound preferably has two groups thereof, since 
it is desirable that the compound be copolymerized in polyester molecular 
chains in view of obtaining high shrinking characteristics of the 
resulting polyester fibers and high polymerizability. The two functional 
groups may either be the same or different. 
In the compound, the carbon atoms other than those bonded to ester-forming 
functional groups are bonded to hydrogen atom or alkyl groups, preferably 
hydrogen atom, which does not impair polymerizability. Examples of 
preferred alkyl groups are those having 1 to 5 carbon atoms, such as 
methyl, ethyl, propyl, butyl and pentyl, which groups may be branched. 
Examples of the compound used in the present invention are 
norbornane-2,3-dimethanol, norbornane-2,3-diethanol, 
norbornane-2,3-dicarboxylic acid, norbornane-2,3-dicarboxylic dimethyl 
ester, norbornane-2,3-dicarboxylic diethyl ester, 
perhydrodimethanonaphthalenedimethanol, 
perhydrodimethanonaphthalenediethanol, 
perhydrodimethanonaphthalenedicarboxylic acid, 
perhydrodimethanonaphthalenedicarboxylic acid dimethyl ester, 
tricyclodecanedimethanol, tricyclodecanediethanol, 
tricyclodecanedicarboxylic acid, tricyclodecanedicarboxylic acid dimethyl 
ester and tricyclodecanedicarboxylic acid diethylesters. These compounds 
may have contain alkyl groups or other substituents, such as sulfonyl 
group, bonded to carbon atoms other than those bonded to ester-forming 
functional groups. Preferred among the above compounds are 
norbornane-2,3-dimethanol, norbornane-2,3-carboxylic acid, 
norbornane-2,3-dicarboxylic acid dimethyl ester, 
perhydrodimethanonaphthalenedimethanol, 
perhydrodimethanonaphthalenedicarboxylic acid, 
perhydrodimethanonaphthanledicarboxylic acid dimethyl ester, 
tricyclodecanedimethanol, tricyclodecanediethanol, 
tricyclodecanedicarboxylic acid and tricyclodecanedicarboxylic acid 
dimethyl ester, which give good polymerizability, spinnability, fiber 
strength and shrinking characteristics. Further in view of 
polymerizability, it is desirable to use norborane-2,3-dimethanol, 
norborane-2,3-dicarboxylic acid, norborane-2,3-dicarboxylic acid dimethyl 
ester, perhydrodimethanonaphthalenedimethanol, 
perhydrodimethanonaphthalenedicarboxylic acid and 
perhydrodimethanonaphthalenedicarboxylic acid dimethyl ester, all having 
the two ester-forming functional groups at the trans positions. 
The polyesters used in the present invention have a principal dicarboxylic 
acid component of terephthalic acid and a principal glycol component of at 
least one alkylene glycol selected from the group consisting of ethylene 
glycol, trimethylene glycol and tetramethylene glycol. The polyesters may 
be further copolymerized with a third component other than the compound 
represented by the structural formula (1) within a limit not to impair the 
purpose of the present invention. 
Examples of the third component are aromatic dicarboxylic acid, e.g. 
isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, 
biphenyldicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 
4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic 
acid, 4,4'-diphenylisopropylidenedicarboxylic acid, 
1,2-diphenoxy-ethane-4'4"-dicarboxylic acid, anthracenedicarboxylic acid, 
2,5-pyridinedicarboxylic acid, diphenoxyketonedicarboxylic acid, sodium 
5-sulfoisophthalate, sodium dimethyl-5-sulfoisophthalate and 
5-tetrabutylphosphoniumsulfoisophthalic acid; aliphatic dicarboxylic 
acids, e.g. malonic acid, succinic 
acid, adipic acid, azelaic acid and sebacic acid; alicyclic dicarboxylic 
acids, e.g. decalindicarboxylic acid and cyclohexanedicarboxylic acid; 
hydroxycarboxylic acids, e.g. .beta.-hydroxyethoxybenzoic acid, 
p-oxybenzoic acid, hydroxypropionic acid and hydroxyacrylic acid; 
carboxylic acids derived from ester-forming derivatives of the foregoing; 
aliphatic lactones, e.g. .epsilon.-caprolactone; aliphatic diols, e.g. 
hexamethylene glycol, neopentyl glycol, diethylene glycol and polyethylene 
glycol; aromatic diols, e.g. hydroquinone, catechol, naphthalene diol, 
resorcin, bisphenol A, bisphenol A ethylene oxide adducts, bisphenol S and 
bisphenol S ethylene oxide adducts; and aliphatic diols, e.g. 
cyclohexanedimethanol. These third components may be copolymerized singly 
or in combination of two or more. 
The PES (I) used in the present invention may further be copolymerized with 
a multifunctional carboxylic acid such as trimellitic acid, trimesic acid, 
pyromellitic acid or tricarballylic acid, or polyhydric alcohols such as 
glycerin, trimethylolethane, trimethylolpropane or pentaerythritol, as 
long as the resulting polyester is substantially linear. 
The content of the compound represented by structural formula (1) is in the 
range of 2 to 20 mole % based on the dicarboxylic component constituting 
the polyester, preferably 3 to 18 mole %. If the content is less than 2 
mole %, the resulting polyester will not give the intended highly 
shrinkable fiber of the invention, because of insufficient decrease in the 
degree of crystallinity of the polyester. If the content exceeds 20 mole 
%, the polymerizability will decrease and the resulting polyester will 
tend to be of low crystallinity. In this case, if a polyester with 
satisfactory crystallinity is obtained at all, it has a low melting point, 
thereby giving fibers having unsatisfactory heat resistance. 
With increasing content of the compound, the degree of crystallinity and 
melting point of the polyester decrease but the shrinkage ratio of the 
resulting polyester fibers increases. Accordingly, the content of the 
compound is suitably so selected as to meet the required heat resistance, 
shrinking characteristics and dyeability to each end-use, within the range 
specified in the present invention. 
The polyesters used in the present invention can be obtained by any 
conventional polymerization process. For example, there may be employed a 
process which comprises a first step of carrying out direct esterification 
of terephthalic acid and an alkylene glycol, transesterification of a 
lower alkyl ester of terephthalic acid such as dimethyl terephthalate and 
an alkylene glycol, or reaction of terephthalic acid with an alkylene 
oxide, to form an alkylene glycol ester of terephthalic acid and/or its 
oligomers and a second step of polycondensing the reaction product of the 
first step to a desired degree of polymerization, with a polymerization 
catalyst such as antimony trioxide, germanium oxide or tetralkoxyethane at 
a temperature of 230.degree. to 300.degree. C. under reduced pressure. In 
the above cases, the compound represented by structural formula (1) can be 
added in a prescribed amount at any step until the end of polycondensation 
reaction, for example added to the starting materials for the polyester or 
at a period after the transesterification and before the polycondensation. 
It is also possible, in order to increase the degree of polymerization, to 
effect polymerization at first in the liquid phase and then conduct solid 
phase polymerization. 
The PES (I) used in the present invention preferably has an intrinsic 
viscosity (determined at 30.degree. C. in a 50/50 by weight mixed solvent 
of phenol/tetrachloroethane) of 0.4 to 1.5. If the intrinsic viscosity of 
the PES (I) is less than 0.4, the resulting fiber will have too poor 
strength and shrinking characteristics to achieve the object of the 
present invention. On the other hand, i.e. the intrinsic viscosity of the 
PES (I) exceeds 1.5, the polyester will have too high a melt viscosity, 
thereby deteriorating fiber formability, such as spinnability and 
drawability. 
The PES (I) used in the invention may, as required, incorporate additives 
such as antioxidants, UV absorbers, fluorescent whitening agents, 
delustering agents, antistatic agents, flame-retardants, auxiliary flame 
retardants, lubricants, colorants, plasticizers and inorganic fillers, 
within limits not to impair the purpose of the invention. 
The PES fiber (II) of the present invention can be obtained by the usual 
melt spinning. The obtained as-spun filaments are drawn in the usual 
manner, i.e. under drawing conditions generally employed for conventional 
polyester fibers. Thus, the as-spun filaments are preheated through hot 
rolls, and heat drawn at a draw ratio conforming to the speed of take-up 
roll. Instead, there may be employed spin-drawing which connects spinning 
directly with heat drawing. 
The PES fiber (II) may have any cross-sectional shape such as circular, 
multi-lobal including 3 to 8-lobal, T-shaped, V-shaped, flat or square. 
The PES fiber (II) may not necessarily be solid, but may be hollow or 
porous. There is no particular limitation to the size (fineness) of the 
PES fiber (II), and it may have any-optional fineness according to the 
intended use. The PES fiber (II) may have a fineness unevenness along the 
fiber axis. 
The PES fiber (II) can be used not only in the form of filament yarns but 
in the form of staple fibers. 
The PES fiber (II) has a birefringence .DELTA. n satisfying the following 
condition (2). 
EQU -5.55.times.A+80.ltoreq..DELTA.n.times.10.sup.3 .ltoreq.-5.55.times.A+165 
(2) 
wherein A is the content of the compound represented by structural formula 
(1) in mole %. 
The value of birefringence .DELTA. n being in the above range realizes the 
excellent dyeability and deep color dyeability of the polyester fibers 
when dyed. 
Incorporation of the compound represented by structural formula (1) into 
molecular chains of polyester makes the aliphatic cyclic skeleton of the 
compound be positioned on the side chains of the molecular chains. Due to 
this conformation, even a small content of the compound can increase the 
degree of amorphous state, suppress the decrease of the second-order 
transition temperature and accumulate stress generating upon relaxation of 
the resulting fiber when it shrinks by heat. As a result, the fiber 
becomes highly shrinkable and, at the same time, has excellent heat 
resistance, colorfastness and lightfastness. The lightfastness herein can 
be expressed in terms of that against carbon arc light, and the above PES 
fiber (II) is ranked at at least class 4. There is no limitation to dyeing 
conditions employed for the fiber and all disperse dyes, cationic dyes and 
acidic dyes are usable for providing any shade ranging from light to dark. 
The PES fibers (II) of the present invention can be provided not only with 
high shrinkage ratios but high shrinking stress by properly adjusting 
drawing conditions. 
Generally speaking, highly shrinkable fibers show a low shrinking stress. 
However, the polyester fibers of the present invention have, when drawn 
under specific conditions, both a high shrinkage ratio and a high 
shrinking stress. 
That is, the polyester as-spun filaments produced by the usual melt 
spinning process are, after being once taken up or directly, drawn with 
heating. It is desirable to preheat the as-spun filaments at a temperature 
of around 75.degree. to 95.degree. C. through hot rolls, before feeding to 
a drawing zone. Then, the preheated filaments are drawn at a temperature 
of 150.degree. C. or less, preferably 140.degree. C. or less at a draw 
ratio of at least 0.68 time, preferably at least 0.7 time the maximum draw 
ratio at breakage. If the drawing temperature exceeds 150.degree. C., the 
shrinkage ratio of the resulting filaments will decrease. If the draw 
ratio is less than 0.68 time the maximum draw ratio, the resulting 
filaments will have insufficient heat shrinking stress and too large a 
remaining elongation and hence become hard to form into clothing. 
The thus obtained drawn polyester filaments (hereinafter referred to as 
"drawn PES fibers (III)" or "drawn PES filaments (III)") have a high 
shrinkage ratio and high shrinking stress, i.e. a dry heat shrinkage ratio 
at 180.degree. C. of at least 20%, a dry heat maximum shrinking stress of 
at least 250 mg/denier and a wet heat shrinkage ratio at 98.degree. C. of 
at least 15%. The filaments satisfying the above three conditions of dry 
heat shrinkage ratio, dry heat maximum shrinking stress and wet heat 
shrinkage ratio at the same time give, when used as core yarn of 
sheath-core textured yarns or as a component of mixed filament yarns with 
differently shrinkable filaments as described later herein, woven or knit 
fabrics having a good hand. These fabrics can, aiter post-treatment, be 
provided with an appropriate HARI (anti-drape stiffness), KOSHI 
(stiffness) and bulk. 
If the drawn PES filaments (III) having a dry heat shrinkage ratio of less 
than 20% are used as core filaments of sheath-core textured yarns as 
described later, woven or knitted fabrics prepared therefrom will tend to 
be insufficient in bulkiness because of the insufficient shrinkage of the 
drawn PES filaments (III). Although there is no limitation to the upper 
limit of dry heat shrinkage ratio, it is preferably less than 80%, more 
preferably in the range of 20 to 75% in view of degradation of fiber 
properties. 
With the drawn PES filaments (III) having a wet heat shrinkage ratio at 
98.degree. C. of less than 15%, the difference between the dry heat 
shrinkage ratio and wet heat shrinkage ratio is too large. Woven or knit 
fabrics utilizing such filaments will tend to have poor dimensional 
stability and dimensional uniformity because the drawn PES filaments (III) 
shrink too much during processing, for example dry heat treatment such as 
heat setting after hot water treatment, dyeing or like wet heat 
treatments. Although there is no particular limitation to the upper limit 
of the wet heat shrinkage ratio, it is preferably 75% or less, more 
preferably in the range of 15 to 70%, in view of physical properties, 
especially collapsing tendency of finished woven or knit fabrics. There is 
no limitation to the difference between dry heat shrinkage ratio and wet 
heat shrinkage ratio either, but it is preferably in the range of 1 to 30% 
because of the same reasons as described above. 
Ease of shrinking of fibers or woven and knit fabrics under restrained 
conditions depends on the shrinking stress of the fibers constituting the 
fabrics. The larger the shrinking stress of the fibers, the more easily 
the shrinkage occurs even under restrained conditions. The fibers having a 
dry heat maximum shrinking stress of at least 250 mg/denier can shrink 
sufficiently even under restrained conditions. 
The drawn PES filaments (III) can be used for mixed filament yarns with 
differently shrinkable filaments and sheath-core textured yarns. 
Firstly, the application to the mixed filament yarns is explained. 
Conventional mixed filament yarns with differently shrinkable filaments 
comprising differently shrinkable polyethylene terephthalate filaments are 
used for preparing woven and knit silk-like fabrics with soft hand and 
drape to be used principally for women's dresses and blouses. These mixed 
filament yarns have been produced by mixing drawn yarns having different 
boiling water shrinkage ratios, or by drawing undrawn yarns having the 
same physical properties under different heating conditions, followed by 
mixing thereof. However, with these processes, simply mixing filaments 
having different boiling water shrinkage ratios, the original shrinkage 
difference decreases through heat history ending at weaving or knitting. 
Besides, the resulting woven or knit fabrics have poor hand, because of a 
small stress accumulated due to the heat shrinkage difference under their 
restrained conditions. 
Where the drawn PES filaments (III) are applied as highly shrinkable 
filaments for these conventional mixed filament yarns with differently 
shrinkable filaments, the above problems are solved and, further, there 
can be obtained the practical advantage of excellent lightfastness. 
The mixed filament yarns with differently shrinkable filaments according to 
the present invention comprise a highly shrinkable filament group of the 
above drawn RES filaments (III) and a less shrinkable filament group of 
filaments having a smaller shrinkage ratio as compared to the drawn PES 
filaments (III), the two groups having been mixed together by entangling 
or mixed spinning. It is desirable that the difference between the wet 
heat shrinkage ratio at 98.degree. C. (hereinafter simply referred to as 
"wet heat shrink ratio") of the high shrinkable filament group and that of 
the less shrinkable filament groups be at least 8%. If the wet heat 
shrinkage ratio difference is less than 8%, woven or knit fabrics 
comprising the mixed yarn will hardly exhibit sufficient heat shrinking 
behavior. That is, in order to form a specific structure, after a woven or 
knit fabric has been made, where highly shrinkable filaments are 
positioned at the core part and less shrinkable filaments at the sheath, 
paying attention only to the wet heat shrinkage ratio difference as the 
measure is not sufficient. The synergetic effect produced by the 
difference in wet heat shrinkage ratio between the highly shrinkable 
filaments and less shrinkable filaments, together with the maximum dry 
heat shrinking stress of the highly shrinkable filaments, can realize a 
sufficient heat shrinking behavior of the woven or knit fabrics during 
post-treatment processes, whereby excellent hand including HARI, KOSHI and 
bulky feeling can be obtained. 
To achieve a sufficient heat shrinking behavior for woven or knit fabrics 
during post-treatment processes, it is desirable that the difference in 
wet heat shrinkage ratio between highly shrinkable filaments and less 
shrinkable fibers be in the range of 8 to 60%, preferably 10 to 55%. 
It is also desirable that these mixed filament yarns with differently 
shrinkable filaments have, by themselves, a wet heat shrinkage ratio of 10 
to 55%, particularly 10 to 50%. If the wet heat shrinkage ratio of the 
mixed yarn is less than 10%, finished woven or knit fabrics will have 
insufficient hand, such as HARI, KOSHI and bulky feeling. On the other 
hand, if the wet heat shrinkage ratio exceeds 55%, the mixed filament 
yarns will tend to have poor heat stability. 
It is further desirable that filaments constituting the highly shrinkable 
filament group of the mixed filament yarns, i.e. the drawn PES filaments 
(III), have a fineness of 1 to 10 deniers and those of the less shrinkable 
filament group have a fineness of not more than 5 denier, and that the 
weight ratio between the highly shrinkable filament group and the less 
shrinkable filament group be in the range of 2:1 to 1:5, in order to 
obtain a good hand of the resulting woven or knit fabrics. There is no 
specific limitation to the type of the polymer constituting the less 
shrinkable filament group, and any one of polyester, rayon, polyamide and 
like filaments, having a wet heat shrinkage ratio of at least 8% smaller 
than that of the drawn PES filaments (III) can be used. 
With the mixed filament yarns, the difference in the filament length 
between the drawn PES filaments (III) and less shrinkable filaments are 
preferably at least 4%. If the difference is less than 4%, woven or knit 
fabrics utilizing the mixed filament yarns will lack a good hand, such as 
bulky feeling and softness. The upper end of the difference is not 
particularly limited, but it is preferably not more than 30% and may be 
adjusted according to the intended use. 
The mixed filament yarns can be produced by the usual mixed spinning, mixed 
drawing, air jet entangling or like processes, and can further be 
subjected to an air entanglement process such as interlacing or Taslan 
texturing, which improves the stable runnability 5 the yarns during 
processing, weaving or knitting. The mixed filament yarns may have loops 
or fluffs. 
Next, the application of the drawn PES filaments (III) to sheath-core 
textured yarns is described. 
The use of the drawn PES filaments (III) as the core part of a sheath-core 
textured yarn makes it a soft "spun-like" textured yarn having an 
excellent hand. With this type of sheath-core textured yarn, it is 
desirable that filament entanglements be further formed by air entangling 
at specific intervals along the yarn direction, in order to obtain a good 
bulkiness upon false-twisting and a good unwindability after false 
twisting. The core and sheath filaments are held together, to give a soft 
textured yarn having a superior soft hand. The air entanglement may be 
applied either before or alter false twisting, according to the intended 
purpose. The false twisting is desirably carried out at a temperature 
below the melting point of low melting filaments. The false twisting 
number T can be the same as that of conventional polyester textured yarns 
and is preferably in the range determined by the following formula. 
EQU T=T.sub.0 {150/[D.times.(R.sup.1 /R.sup.2)]}.sup.1/2 
EQU R.sup.1 /R.sup.2 =k.multidot.r 
wherein 1200.ltoreq.T.sub.0 2800, and 0.9.ltoreq.k.ltoreq.1.4, R.sup.1 
represents the speed of feed roll for feed yarn and R.sup.2 that of 
delivery roll, r is the speed ratio between R.sup.1 and R.sup.2 generally 
employed for manufacturing bulky yarns, and D the fineness (deniers) of 
feed yarn. 
The finenesses of sheath and core yarns should be selected according to the 
intended use but, generally, the fineness of sheath yarn is preferably 
larger or equal to that of core yarn. The sheath yarn used preferably 
comprises a polyester, which may by modified. It is also possible to use 
for this purpose a composite fiber comprising a polyester and a polyamide. 
The PES (I) of the present invention can be used for producing composite 
fibers and blended spun yarns. 
Firstly, the use for composite yarns is described. 
The PES (I) can, while being combined with other fiber-forming polymers, be 
formed into composite fibers, which are then drawn under the drawing 
conditions as described above. Then, the resulting fibers may, depending 
on the composite configuration, develop self-crimpability due to the 
difference in the shrinkability of two components; develop fine wrinkles 
on the fiber surface formed by the other fiber-forming polymer due to the 
high shrinkability of the PES (I); or develop efficient delamination due 
to the large shrinkage difference. Accordingly, the composite fibers can 
provide fabrics having excellent features similar to natural fibers, such 
as good elasticity, HARI, KOSHI, bulk, slippery nature, flexibility and 
softness. 
Examples of composite configurations are side-by-side, sheath-core, 
eccentric sheath-core, multilayer laminate and radial. Any one of these 
configurations may be suitably selected according to the intended use, as 
long as it enables the PES (I) to exhibit high shinkability. 
Conventional crimpable composite fibers are of side-by-side or eccentric 
sheath-core type and comprise components of polyethylene terephthalates 
with different degrees of polymerization, polyethylene terephthalate and 
polybutylene terephthalate, a polyester copolymerized with isophthalaic 
acid and a polyethylene oxide adducts of bisphenol A and polyethylene 
terephthalate, and like combinations. However, these conventional 
composite fibers are insufficient in shrinking characteristics or, if they 
have satisfactory shrinkability at all, insufficent in lightfastness. 
Composite fibers comprising the PES (I) and other fiber-forming polymers 
have solved the problem of insufficient colorfastness, and have sufficient 
shrinking characteristics. Nonwoven fabrics comprising these composite 
fibers are useful, utilizing the good shrinking characteristics. 
Application to blended spun yarns is described now. 
Staple fibers of the drawn PES fibers (III) and other synthetic fibers 
and/or natural fibers are blend-spun by the usual process into blended 
yarns. Woven or knit fabrics comprising the blended yarns produce, upon 
heat treatment, a good bulk, since the staple of the drawn PES fibers 
(III) shrink sufficiently even under restraint of woven or knit 
construction. These woven or knit fabrics also show excellent 
lightfastness as compared to conventional products, and are hence very 
useful for practical purposes. 
There is no specific limitations to the fineness, cut length, twist number 
and blend ratio of the drawn PES fibers (III) and the other synthetic 
and/or natural fibers used for this purpose, and these factors can 
appropriately set according to the intended use. 
While composite fibers, mixed filament yarns, sheath-core textured yarns 
and blended spun yarns utilizing the PES (I), PES fibers (II) and drawn 
PES fibers (III) have been described, the present invention also includes 
woven and knit fabrics utilizing these polymer and fibers. 
Examples of such fabrics include woven, knit and nonwoven fabrics and pile 
fabrics using the drawn PES fibers (III) as the ground yarns or pile 
yarns. These fabrics preferably contain the drawn PES fibers (III), 
composite fibers, mixed filament yarns, blended spun yarns or sheath-core 
textured yarns in an amount of at least 20% by weight, more preferably at 
least 30%. If the content is less than 20% by weight, the fibers of the 
present invention will shrink only insufficiently under restraint of woven 
or knit construction, thereby failing to provide desired products. Even if 
the desired products are obtained at all, they are insufficient in HARI, 
KOSHI, resilience or bulk, or have so poor dimensional stability that they 
will be elongated or collapsed when put under external forces. 
The fabrics, containing the highly shrinkable fibers, no longer suffer from 
problems inherent to conventional fabrics of similar construction, such as 
poor hand and insufficient lightfastness. Pile fabrics containing the 
shrinkable fibers can be provided with high density and high bulkiness. 
The present invention will be described in further detail with reference to 
the following examples. 
In the Examples, Comparative Examples and Reference Examples that follow, 
various properties were determined according to the methods given below. 
[Content of the compound represented by formula (1) (mole %) 
Calculated from the results of .sup.1 H-NMR spectroscopy on a polyester 
sample dissolved in deuterated trifluoroacetic acid. 
[Intrinsic viscosity of polyester (dl/g)] 
Determined by measurement in a 1/1 by weight mixed solvent of 
phenol/tetrachloroethane at 30.degree. C. 
[Melting point (.degree.C.), glass transition temperature (.degree.C.) and 
degree of crystallinity (J/g)] 
A differential scanning calorimeter (Mettler TA 3000 type, manufactured by 
Perkin-Elmer Inc.) is used. A 10-mg sample is tested at a temperature 
elevation and decreasing rates of both 10.degree. C./min., while the air 
in the apparatus is replaced by nitrogen. The same sample is subjected to 
this procedure twice and the data obtained by the second measurement is 
taken as the observed values. Separately, a sample is heat treated to 
crystallize sufficiently and then tested with the same apparatus, to 
obtain a heat of fusion of crystal (J/g), which is taken as an index of 
the degree of crystallinity. 
[Birefringence of polyester fiber] 
Measured in a -bromonaphthalene, with sodium vapor light source and under a 
polarized microscope, with a Berek compensator inserted into the light 
passage. 
[Dry heat shrinkage ratio of polyester fiber (Dsr, %)] 
A filament specimen is marked for a length of 50 cm under an initial load 
of 1 mg/denier (hereinafter "denier" is sometimes expressed as "d"). The 
specimen is allowed to stand for 10 minutes under a load of 5 mg/d in a 
dry heat atmosphere at 180.degree. C., and then taken out and measured for 
the distance, L cm, between the marks under a load of 1 mg/d. The dry heat 
shrinkage ratio is calculated by: 
Dry heat shrinkage ratio (Dsr, %)=[(50-L)/50].times.100 
[Dry heat shrinking stress of polyester fiber (mg/d)] 
A 20-cm test filament sample is mounted on a tensile tester (Autograph) 
and, after application of an initial load of 50 mg/d, heated at a 
temperature elevation rate of .degree. C./min. The shrinking force 
developed during this heating is measured. 
[Wet heat shrinkage ratio of polyester fiber (Wsr, %)] 
A filament specimen is marked for a 50-cm length under an initial load of 1 
mg/d. Then the specimen is immersed in hot water at 98.degree. C. for 30 
minutes under a load of 5 mg/d. The specimen is taken out from hot water 
and the distance, L' cm, between the marks is measured. The wet shrinkage 
ratio is calculated by: 
Wet heat shrinkage ratio (Wsr, %)=[(50-L')/50].times.100 
[Wet heat shrinkage ratio of mixed filament yarn (Wsr, %)] 
Determined in the same manner as for the above wet heat shrinkage ratio of 
polyester fiber. 
[Difference in wet shrinkage ratio between filament groups constituting 
mixed filament yarn (.DELTA.W, %)] 
A mixed filament yarn sample is separated into constituting filament 
groups, which are then each tested for the wet shrinkage ratio according 
to the above method. The difference between the obtained values is 
calculated. 
[Difference in fiber length of filament groups constituting mixed filament 
yarn (1, %)] 
A mixed filament yarn sample is marked for a 50-cm length and then 
separated into composing filament groups. The groups are each measured for 
the distance, l.sub.1 and l.sub.2, under a load of 1 mg/d. The difference 
between l.sub.1 and l.sub.2 is calculated. 
[Lightfastness] 
A fabric sample is dyed under the following conditions and the dyed sample 
is tested for lightfastness according to JIS L0842-1988. 
______________________________________ 
Dyeing 
Dye: Sumikaron Red S-BL (manufactured by 
0.1 or 3.0% 
Sumitomo Chemical Co., Ltd.) 
Dispersing agent: Disper TL (manufactured by 
1 g/l 
Meisei Kagaku K.K.) 
pH regulator: acetic acid 0.5 cc/l 
Dyeing time: 60 min 
Dyeing temperature: 130.degree. C. 
Bath ratio: 1:50 
Alkali reduction cleaning 
Sodium hydroxide: 1 g/l 
Amylazin (Dai-ichi Kogyo Seiyaku Co., Ltd.): 
1 g/l 
Hydrosulfite: 1 g/l 
Cleaning time: 20 min 
Cleaning temperature: 80.degree. C. 
Bath ratio: 1:50 
______________________________________ 
[Color depth of dyed fabric (K/S)] 
A dyed fabric sample, having been dyed under the above conditions with a 
dye concentration of 3.0%, is tested for spectral reflectance (R) with a 
color analyzer (an automatic recording spectrophotometer manufactured by 
Hitachi Ltd.). The color depth is obtained by the following Kubelka-Munk 
formula. A larger K/S value means a deeper color. 
EQU K/S=(1-R).sup.2 /2R 
wherein R is the spectral reflectance at the maximum absorption wave length 
on the reflectance curve in the visual light range. 
[Evaluation of fabric hand and elasticity] 
The hand as represented by bulk, softness, HARI, KOSHI and scrooping 
feeling, and elasticity of a fabric sample is organoleptically evaluated 
by pair comparison method. 
Reference Example A 
A slurry was prepared from a mixed diol of 4.2 mole % of 
norbornane-2,3-dimethanol (a compound as shown in Table 1) and 95.8 mole % 
of ethylene glycol, and terephthalic acid in a molar ratio between the 
diol and terephthalic acid of 1.2:1. The slurry was subjected to 
esterification under pressure (absolute pressure: 2.5 kg/cm.sup.2) at 
250.degree. C. to a conversion of 95%, to give a low-polymerization-degree 
product. Then, 350 ppm of antimony trioxide as a catalyst was added to the 
product, and polycondensation was effected under a reduced pressure of 1 
torr (absolute pressure) at 280.degree. C. for 1.5 hours, to obtain a 
polyester having an intrinsic viscosity of 0.70 dl/g. The obtained 
polyester was extruded through nozzles into strands, which were then cut 
into cylindrical chips having a diameter of 2.8 mm and a length of 3.2 mm. 
The obtained polyester chips were analyzed by NMR spectroscopy, to prove to 
be a polyester having as a copolymerization component 
norbornane-2,3-dimethanol in an amount of 5 mole % based on the total 
dicarboxylic acid component. The polyester chip was found to have a Tg 
(glass transition temperature) of 78.degree. C., a Tm (melting point) of 
241.degree. C. and a heat of fusion of crystal after crystallization 
treatment of 36 J/g. 
Reference Examples B through Q 
Reference Example A was repeated except that each of the compounds shown in 
Table 1 was used in a copolymerization amount as shown, to obtain groups 
of polyester chips. The Tg, Tm and heat of fusion of crystal of each of 
the obtained polyesters were measured and shown in Table 1. 
Reference Examples a through q 
Reference Example A was repeated except that a polyethylene terephthalate 
having an intrinsic viscosity of 0.70 dl/g (Reference Example a) and 
compounds as shown in Tables 2 and 3 were each used in a copolymerization 
amount as shown, to obtain a series of polyester chips. Each of the 
polyester was tested for intrinsic viscosity, Tg, Tm and heat of fusion of 
crystal. The results are shown in Tables 2 and 3. 
EXAMPLE 1 
The polyester chips obtained in Reference Example A were melted in a 
extruder and extruded at 290.degree. C. through a spinneret with 24 holes 
having a diameter of 0.25 mm, and the extruded filaments were taken up at 
a speed of 1,000 m/min. The obtained polyester yarn was drawn through a 
hot roll at 85.degree. C. and a hot plate at 100.degree. C. (Example 1--1) 
or 120.degree. C. (Example 1-2) at a speed of 500 m/min., to give 
multifilament yarns of 75 denlet/24 filaments. The draw ratios were both 
3.20, which was 0.75 time the maximum draw ratio at break. 
The properties of the obtained multifilament yarns were shown in Table 4. 
The filament yarns comprising the polyester copolymerized with 
norbornane-2,3-dimethanol in a specific amount had a high dry heat 
shrinkage ratio and wet heat shrinkage ratio, as well as high dry heat 
shrinking stress. 
Pile knit fabrics were prepared using these multifilament yarns as ground 
yarn, and it was found that the pile knit fabrics had a high pile density 
with high quality surface appearance. These pile knit fabrics were dyed 
under the aforementioned conditions, to yield colored knit fabrics having 
a low birefringence and good color depth due thereto, as well as a high 
colorfastness of class 5. 
COMATIVE EXAMPLE 1 
Example 1 was repeated except that the polyethylene terephthalate obtained 
in Reference Example a, to obtain multifilament yarns of 75 denier/24 
filaments. 
The properties of the multifilament yarns obtained were measured and are 
shown in Table 5. 
The multifilament yarns showed a dry heat shrinking stress of the same 
level as that oE the yarns obtained in Example 1, but had a markedly small 
dry heat shrinkage ratio and wet heat shrinkage ratio. 
Pile knit fabric were prepared using each of the multifilament yarns as 
ground yarn, and it was found that the pile knit fabrics had a small pile 
density, thus lacking high quality appearance. The pile knit fabrics were 
dyed in the same manner as in Example 1. The dyed fabrics had a high 
lightfastness of class 5, but had a high birefringence and low color 
depth. 
EXAMPLES 2 THROUGH 17 
Multifilament yarns of 75 denier/24 filaments were prepared in the same 
manner as in Example 1, except for using the polyester chips obtained in 
Reference Examples B through Q. The properties of the obtained 
multifilament yarns are shown in Table 4. The multifilament yarns, while 
having a high heat shrinking stress of the same level as those of the 
yarns obtained in Comparative Example 1, still had a high dry heat 
shrinkage ratio and wet heat shrinkage ratio. Pile knit fabrics were 
prepared using the obtained multifilament yarns as ground yarn, and then 
dyed, in the same manner as in Example 1. The dyed fabrics showed a high 
color depth thanks to low birefringence and had sufficient lightfastness, 
thus proving of high practical utility. 
COMATIVE EXAMPLES 2 THROUGH 7 
Multifilament yarns of 75 denier/24 filaments were prepared in the same 
manner as in Example 1, except for using the polyester chips obtained in 
Reference Examples a through g. The properties of the obtained 
multifilament yarns are shown in Table 5. Although the multifilament yarns 
had a high heat shrinking stress of the same degree as that of the yarns 
obtained in Comparative Example 1, they showed a low dry heat shrinkage 
ratio and wet heat shrinkage ratio. The pile fabrics using the yarns as 
ground yarn had a small pile density, thus lacking high quality 
appearance. 
COMATIVE EXAMPLES 8 THROUGH 13 
Attempts were made to use the polyester chips obtained in Reference 
Examples h through m and conduct spinning and drawing in the same manner 
as in Example 1. However, satisfactory drawn yarns could not be obtained 
due to frequent yarn breakages during drawing because of the amorphous 
nature of the polyesters. 
COMATIVE EXAMPLE 14 
Multifilament yarns of 75 denlet/24 filaments were prepared in the same 
manner as in Example 1, except for using the polyester chips obtained in 
Reference Example n. The properties of the obtained multifilament yarns 
are shown in Table 5. Although the multifilament yarns had a dry heat 
shrinkage ratio and wet heat shrinkage ratio of the same level as those of 
the yarns obtained in Examples, they showed a very low dry heat shrinking 
stress. The pile fabrics using the yarns as ground yarn, with which a 
sufficient shrinkage could not be obtained due to the low shrinking 
stress, had a small pile density, thus lacking high quality appearance. 
COMATIVE EXAMPLES 15 THROUGH 17 
Multifilament yarns of 75 denier/24 filaments were prepared in the same 
manner as in Example 1, except for using the polyester chips obtained in 
Reference Examples o through q. The properties of the obtained 
multifilament yarns are shown in Table 5. Although the multifilament yarns 
had a dry heat shrinkage ratio, dry heat shrinking stress and wet heat 
shrinkage ratio all of the same level as those of the yarns obtained in 
Examples, they showed, when formed into a knit fabric and dyed in the same 
manner as in Example 1, a low lightfastness of 1-2 class, thus proving to 
be of no practical utility. 
EXAMPLE 18 
A mixed filament yarn with 2 units/inch of entanglements was prepared with 
a fluid entangling apparatus under an air pressure of 5 kg/cm.sup.2, using 
the multifilament yarn obtained in Example 1--1 as a highly shrinkable 
filament group and the multifilament yarn obtained in Comparative Example 
1--2 as a less shrinkable filament group. The difference (.DELTA.W, %) in 
wet heat shrinkage ratio between the two filament groups constituting the 
mixed yarn was found to be 15%, and the wet heat shrinkage ratio (Wsr', %) 
and filament length difference of the mixed yarn were 20% and 10%, 
respectively. 
The mixed yarn thus obtained was twisted to 300 T/m, and the twisted yarn 
was used as both warps and wefts, to weave a fabric, which was dyed and 
finished by the usual processes to give a twill fabric. 
The twill fabric thus obtained was organoleptically evaluated, to prove to 
have an excellent hand, as evaluated in terms of bulk, softness, HARI, 
KOSHI and cripsiness. The fabric also had good color depth and 
lightfastness. 
COMATIVE EXAMPLE 18 
Example 18 was repeated except that the multifilament yarn obtained in 
Comparative Example 2--1 was used as a highly shrinkable filament group, 
to prepare a mixed filament yarn. The difference (.DELTA.W, %) in wet heat 
shrinkage ratio between the two filament groups constituting the mixed 
yarn was found to be 4%, and the wet heat shrinkage ratio (Wsr', %) and 
filament length difference of the mixed yarn were 12% and 2%, 
respectively. 
The mixed filament yarn was twisted to 300 T/m, and the twisted yarn was 
used as both warps and wefts, to weave a fabric, which was dyed and 
finished to give a twill fabric. 
The twill fabric thus obtained was organoleptically evaluated, to prove to 
have poor hand, lacking bulky feeling and softness. 
COMATIVE EXAMPLE 19 
Example 18 was repeated except that the multifilament yarn obtained in 
Comparative Example 16--1 was used as a highly shrinkable filament group, 
to prepare a mixed filament yarn. The difference (.DELTA.W, %) in wet heat 
shrinkage ratio between the two filament groups constituting the mixed 
yarn was found to be 4%, and the wet heat shrinkage ratio (Wsr', %) and 
filament length difference of the mixed yarn were 12% and 2%, 
respectively. 
The mixed filament yarn was twisted to 300 T/m, and the twisted yarn was 
used as both warps and wefts, to weave a fabric, which was dyed and 
finished by the usual processes, to give a twill fabric. 
The twill fabric thus obtained was organoleptically evaluated, to prove to 
have poor hand, lacking bulky feeling and softness. 
EXAMPLE 19 
A sheath-core textured yarn was prepared by combining a highly shrinkable 
filament group of the multifilament yarn obtained in Example 1--1 and a 
less shrinkable filament group of the multifilament yarn obtained in 
Comparative Example 1--2, then providing the combined yarn with 2 
units/inch of entanglements with a fluid processor under an air pressure 
of 5 kg/cm.sup.2, and false twisting the yarn to a twist number of 2,000 
T/m at a temperature of 180.degree. C. 
The textured yarn thus obtained was twisted to 300 T/m, and the twisted 
yarn was used as both warps and wefts, to weave a fabric, which was then 
dyed and finished by the usual processes to give a twill fabric. The 
difference in filament length between the core yarn and sheath yarn of the 
sheath-core textured yarn constituting the fabric was 8%. 
The twill fabric thus obtained was organoleptically evaluated, to prove to 
have excellent hand, as evaluated in terms of bulk, softness, HARI, KOSHI 
and cripsiness. The fabric also had good color depth and lightfastness. 
COMATIVE EXAMPLE 20 
Example 19 was repeated except that the multifilament yarn obtained in 
Comparative Example 2--1 was used as a highly shrinkable filament group 
and that the false twisting temperature was changed to 200.degree. C., to 
obtain a sheath-core textured yarn. 
The textured yarn thus obtained was woven into a twill fabric in the same 
manner as in Example 19. The difference in filament length between the 
core yarn and sheath yarn of the sheath-core textured yarn constituting 
the fabric was 2%. Due to this small difference of 2%, i.e. the small 
shrinkage ratio of the multifilament yarn used as the highly shrinkable 
filament group, the fabric had a poor hand. 
COMATIVE EXAMPLE 21 
Example 19 was repeated except that the multifilament yarn obtained in 
Comparative Example 16--1 was used as a highly shrinkable filament group 
and that the false twisting temperature was changed to 200.degree. C., to 
obtain a sheath-core textured yarn. 
The textured yarn thus obtained was woven into a twill fabric in the same 
manner as in Example 19. The difference in filament length between the 
core yarn and sheath yarn of the sheath-core textured yarn constituting 
the fabric was 7%. 
Although the hand of the fabric was as good as that in Example 19, the 
lightfastness was a very poor class 1--2. 
EXAMPLE 20 
Composite melt spinning was conducted with the polyester chips obtained in 
Reference Example A and those obtained in Reference Example a in such a 
manner as to form a side-by-side configuration, to obtain as-spun 
filaments. The as-spun filaments were then drawn in the same manner as in 
Example 1, to give a composite multifilament yarn of 75 denier/24 
filaments. 
The composite multifilament yarn thus obtained was twisted to 300 T/m, and 
the twisted yarn was used as both warps and wefts, to weave a fabric, 
which was then dyed and finished by the usual processes, to give a twill 
fabric. 
The composite multifilament yarns constituting the obtained fabric had 
developed very fine spiral crimps during the finishing processes due to 
the difference in shrinkage ratio of the polyesters constituting the 
filaments. The obtained fabric had a moderate elasticity and a similar 
bulk, HARI, KOSHI and resilience to those of woolen fabric. Further the 
obtained fabric was excellent in color depth and had sufficient 
lightfastness for practical use. 
Separately, the above side-by-side composite filament yarns were cut into 
staple fibers having a length of 51 mm, which were then formed into a 
nonwoven fabric. The nonwoven fabric had a good elasticity with the 
constituting fibers being crimped due to heating during processing. The 
nonwoven fabric showed, when dyed, excellent color depth and 
lightfastness. 
COMATIVE EXAMPLE 22 
A composite multifilament yarn was prepared by following the same procedure 
as in Example 20 except that the polyester chips obtained in Reference 
Example b were used instead of those obtained in Reference Example A. A 
twill fabric was prepared from the composite multifilament yarn in the 
same manner as in Example 20, and organoleptically evaluated in the same 
manner. 
The obtained fabric, with the constituting filaments having developed fine 
crimps only to a small extent due to the small difference in the shrinkage 
ratio between the polyesters, lacked elasticity, bulki HARI, KOSHI and 
resilience. 
COMATIVE EXAMPLE 23 
A composite multifilament yarn was prepared by following the same procedure 
as in Example 20 except that the polyester chips obtained in Reference 
Example p were used instead of those obtained in Reference Example A. A 
twill fabric was prepared from the composite multifilament yarn in the 
same manner as in Example 20, and organoleptically evaluated in the same 
manner. 
Although the obtained fabric had a good elasticity and hand, it showed a 
very poor lightfastness of class 1 to 2. 
EXAMPLE 21 
A blended spun yarn was prepared by blending the staple fibers obtained by 
cutting the composite filaments obtained in Example 20 to 50 mm and 
polyethylene terephthalate staple fibers having a fineness of 1 denier and 
a cut length of 51 mm, in a ratio by weight of 50:50. The blended yarn was 
used as both warps and wefts, to weave a fabric, which was then dyed and 
finished by the usual processes, to give a twill fabric. 
The obtained fabric, with the constituting composite fibers having 
developed fine crimps caused by heating during processing, had a moderate 
elasticity. The polyethylene terephthalate staple fibers were positioned 
as loops and fluffs on the fabric surface, whereby the fabric showed a 
similar bulk, HARI, KOSHI and resilience to those of woolen fabric. The 
fabric also had a good color depth and lightfastness. 
INDUSTRIAL APPLICABILITY 
The fibers of the present invention have not only excellent dyeability and 
deep color development but also a high shrinkage ratio and shrinking 
stress, as well as excellent lightfastness and colorfastness. The fibers 
are hence useful when used by themselves and also as a component of mixed 
yarns, sheath-core textured yarns or blended yarns. Composite fibers 
having a component of the polyester constituting the fibers of the present 
invention can develop fine crimps and therefore give fabrics having good 
elasticity. 
TABLE 1 
__________________________________________________________________________ 
Amount Intrinsic 
Ref. 
Copolymerization colymerized 
viscosity 
Tg Tm .DELTA. H 
Ex. 
compound (mol %) 
(dl/g) 
(.degree.C.) 
(.degree.C.) 
(J/g) 
__________________________________________________________________________ 
##STR2## 5 0.70 78 241 
36 
B " 10 0.70 80 230 
31 
C " 15 0.70 83 218 
26 
D 
##STR3## 5 0.70 73 240 
38 
E " 10 0.70 71 229 
34 
F " 15 0.70 69 218 
27 
G 
##STR4## 5 0.70 80 239 
35 
H " 10 0.70 85 228 
26 
I " 15 0.70 89 218 
20 
J 
##STR5## 5 0.70 75 240 
33 
K " 10 0.70 76 227 
27 
L " 15 0.70 76 217 
18 
M 
##STR6## 5 0.70 77 239 
35 
N " 10 0.70 79 225 
28 
O " 15 0.70 82 216 
20 
P 
##STR7## 5 0.70 78 238 
28 
Q " 10 0.70 81 223 
19 
__________________________________________________________________________ 
TABLE 2 
__________________________________________________________________________ 
Amount Intrinsic 
Ref. 
Copolymerization colymerized 
viscosity 
Tg Tm .DELTA. H 
Ex. 
compound (mol %) 
(dl/g) 
(.degree.C.) 
(.degree.C.) 
(J/g) 
__________________________________________________________________________ 
a -- 1 0.70 75 254 
42 
##STR8## 1 0.70 75 250 
40 
c 
##STR9## 1 0.70 75 251 
40 
d 
##STR10## 1 0.70 75 249 
38 
e 
##STR11## 1 0.70 75 250 
39 
f 
##STR12## 1 0.70 75 249 
39 
g 
##STR13## 1 0.70 75 248 
38 
h 
##STR14## 1 0.70 89 -- 0 
__________________________________________________________________________ 
TABLE 3 
__________________________________________________________________________ 
Amount Intrinsic 
Ref. 
Copolymerization colymerized 
viscosity 
Tg Tm .DELTA. H 
Ex. 
compound (mol %) 
(dl/g) 
(.degree.C.) 
(.degree.C.) 
(J/g) 
__________________________________________________________________________ 
##STR15## 30 0.70 60 -- 0 
j 
##STR16## 30 0.70 103 
-- 0 
k 
##STR17## 30 0.70 76 -- 0 
l 
##STR18## 30 0.70 87 -- 0 
m 
##STR19## 30 0.70 79 -- 0 
n Isophthalic acid 10 0.70 70 232 
32 
o Isophthalic acid 4 0.70 74 235 
30 
EOBPA*.sup.) 4 
p EOBPA 4 0.70 76 242 
35 
q EOBPA 8 0.70 76 235 
28 
__________________________________________________________________________ 
*.sup.) EOBPA: ethylene oxide adduct of bisphenol A 
TABLE 4 
__________________________________________________________________________ 
Type Fiber 
Draw- 
Fiber properties 
Bire- 
Light- 
of form- 
ing Shrinking 
Bire- 
fringence 
fastness, 
poly- abili- 
temp. 
Dsr 
stress 
Wsr 
frin- 
after 
class 
Ex. 
ester 
ty .degree.C. 
% mg/d % gence 
shrinkage 
0.1% 
3% K/S 
__________________________________________________________________________ 
1-1 
A Good 
100 27 380 24 0.132 
0.117 
5 4-5 
18.2 
2 120 24 380 17 0.133 
0.115 
5 4-5 
18.0 
2-1 
B Good 
100 50 390 47 0.112 
0.107 
5 4-5 
19.8 
2 120 35 390 20 0.114 
0.108 
5 4-5 
19.5 
3-1 
C Good 
100 64 380 59 0.095 
0.087 
4-5 
4 21.1 
2 120 42 390 34 0.093 
0.083 
4-5 
4 20.7 
4-1 
D Good 
100 26 390 22 0.124 
0.111 
5 4-5 
18.9 
2 120 23 400 16 0.121 
0.113 
5 4-5 
18.6 
5-1 
E Good 
100 46 400 41 0.103 
0.095 
5 4-5 
20.5 
2 120 32 400 20 0.104 
0.093 
5 4-5 
20.5 
6-1 
F Good 
100 54 390 51 0.090 
0.082 
5 4-5 
21.6 
2 120 37 400 30 0.091 
0.081 
5 4-5 
21.2 
7-1 
G Good 
100 28 410 25 0.120 
0.107 
5 4-5 
19.4 
2 120 26 400 18 0.119 
0.105 
5 4-5 
19.2 
8-1 
H Good 
100 65 400 60 0.092 
0.084 
5 4-5 
21.0 
2 120 33 410 22 0.091 
0.085 
5 4-5 
20.6 
9-1 
I Good 
100 73 390 68 0.073 
0.065 
4 4 22.1 
2 120 46 390 40 0.070 
0.062 
4 4 21.7 
10-1 
J Good 
100 24 370 20 0.118 
0.109 
5 4-5 
19.4 
2 120 22 380 16 0.118 
0.113 
5 4-5 
19.3 
11-1 
K Good 
100 41 380 35 0.089 
0.082 
5 4-5 
20.8 
2 120 28 380 21 0.090 
0.081 
5 4-5 
20.9 
12-1 
L Good 
100 49 360 45 0.071 
0.063 
4-5 
4 21.8 
2 120 33 370 27 0.070 
0.063 
5 4-5 
21.6 
13-1 
M Good 
100 28 430 24 0.134 
0.115 
4-5 
4 18.5 
2 120 24 440 20 0.130 
0.117 
4-5 
4 18.7 
14-1 
N Good 
100 46 430 40 0.116 
0.109 
4-5 
4 19.4 
2 120 37 430 25 0.112 
0.109 
4-5 
4 19.6 
15-1 
O Good 
100 58 410 51 0.093 
0.088 
4 4 20.6 
2 120 50 420 43 0.095 
0.090 
4 4 20.5 
16-1 
P Good 
100 47 410 42 0.110 
0.101 
5 4 19.7 
2 120 36 420 30 0.111 
0.099 
5 4 19.9 
17-1 
Q Good 
100 66 400 61 0.082 
0.070 
4-5 
4 21.0 
2 120 43 410 39 0.080 
0.073 
4-5 
4 20.7 
__________________________________________________________________________ 
TABLE 5 
__________________________________________________________________________ 
Type Fiber 
Draw- 
Fiber properties 
Bire- 
Light- 
of form- 
ing Shrinking 
Bire- 
fringence 
fastness, 
Comp. 
poly- 
abili- 
temp. 
Dsr 
stress 
Wsr 
frin- 
after 
class 
Ex. ester 
ty .degree.C. 
% mg/d % gence 
shrinkage 
0.1% 
3% K/S 
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1-1 a Good 
100 17 400 12 0.165 
0.156 
5 4-5 
15.6 
2 120 15 410 9 0.166 
0.158 
5 4-5 
15.8 
2-1 b Good 
100 17 400 13 0.156 
0.145 
5 4-5 
16.1 
2 120 16 400 10 0.158 
0.148 
5 4-5 
16.0 
3-1 c Good 
100 17 390 13 0.154 
0.142 
5 4-5 
16.2 
2 120 15 400 10 10.154 
0.146 
5 4-5 
16.0 
4-1 d Good 
100 18 410 14 0.153 
0.145 
5 4-5 
16.4 
2 120 16 410 11 0.156 
0.145 
5 4-5 
16.4 
5-1 e Good 
100 17 390 13 0.156 
0.146 
5 4-5 
16.3 
2 120 15 400 10 0.155 
0.147 
5 4-5 
16.5 
6-1 f Good 
100 18 410 13 0.159 
0.151 
5 4-5 
15.9 
2 120 16 420 11 0.159 
0.152 
5 4-5 
15.8 
7-1 g Good 
100 19 390 15 0.153 
0.144 
5 4-5 
16.3 
2 120 17 410 12 0.154 
0.146 
5 4-5 
16.2 
8 h Poor 
-- -- -- -- -- -- -- -- -- 
9 i Poor 
-- -- -- -- -- -- -- -- -- 
10 j Poor 
-- -- -- -- -- -- -- -- -- 
11 k Poor 
-- -- -- -- -- -- -- -- -- 
12 l Poor 
-- -- -- -- -- -- -- -- -- 
13 m Poor 
-- -- -- -- -- -- -- -- -- 
14-1 
n Good 
100 24 210 18 0.142 
0.131 
4 4 17.6 
2 120 20 240 16 0.143 
0.134 
4 4 17.1 
15-1 
o Good 
100 34 340 28 0.140 
0.128 
1 2 17.9 
2 120 26 350 19 0.141 
0.130 
1 2 17.7 
16-1 
p Good 
100 31 330 27 0.145 
0.131 
1 2 17.1 
2 120 24 330 18 0.143 
0.132 
1 2 16.9 
17-1 
q Good 
100 35 340 31 0.130 
0.119 
1 2 18.2 
2 120 27 350 20 0.131 
0.122 
1 2 18.1 
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