JP2003171536A - Polyester resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel polyester resin composition which mainly comprises an aliphatic polyester having never existed before and is excellent in high- temperature mechanical characteristics and heat resistance. <P>SOLUTION: This polyester resin composition is prepared by blending an aliphatic polyester with 5-40 wt.% aromatic polyester which is prepared by using a 6C or higher diol ingredient or by copolymerizing a 6C or higher diol ingredient and/or a 6C or higher dicarboxylic acid ingredient. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition which is obtained by blending an aliphatic polyester with an aromatic polyester and has excellent high-temperature mechanical properties.

[0002]

2. Description of the Related Art Recently, development of a polymer material that decomposes in a natural environment has been earnestly desired for environmental problems on a global scale. Research and development of various polymers such as aliphatic polyester and practical use Attempts to realize this are becoming more active. Attention has been focused on polymers that are decomposed by microorganisms, that is, biodegradable polymers.

On the other hand, most conventional polymers use petroleum resources as raw materials, but it is possible that petroleum resources will be depleted in the future, and due to the large consumption of petroleum resources, they will be stored underground in the geological era. It is feared that the carbon dioxide that had been released will be released into the atmosphere, and that global warming will become more serious. However, if polymers can be synthesized from plant resources that take in carbon dioxide from the atmosphere and grow and grow, not only can we expect that global warming can be suppressed by the carbon dioxide cycle, but there is also the possibility that the problem of resource depletion can be solved at the same time. . Therefore, attention has been focused on polymers made from plant resources, that is, polymers using biomass.

From the above two points, biodegradable polymers utilizing biomass have attracted great attention and are expected to replace conventional polymers derived from petroleum resources. However, biodegradable polymers using biomass generally have the problems of low mechanical properties and low heat resistance and high cost. As a biodegradable polymer using biomass that can solve these problems, polylactic acid, which is a kind of aliphatic polyester, is currently receiving the most attention. Polylactic acid is a polymer using lactic acid as a raw material, which is obtained by fermenting starch extracted from plants, and has the best balance among mechanical properties, heat resistance and cost among biodegradable polymers using biomass. The development of resin products, fibers, films, sheets, etc. using these is being carried out at a rapid pace.

However, even the most promising polylactic acid has some drawbacks as compared with the conventional polymers made from petroleum resources. Among them, the large one is that the high temperature mechanical properties are poor. Here, the poor high-temperature mechanical properties mean that the polylactic acid polymer is rapidly softened when it exceeds the glass transition temperature (T _g ) of 60 ° C. For example, when the tensile test of polylactic acid fiber is performed at different temperatures, it suddenly softens from around 70 ° C and reaches 90 ° C.
Shows a shape close to that of flow, and the dimensional stability is greatly reduced (Fig. 3). On the other hand, such a softening phenomenon is slow in nylon 6 which is a conventional polymer, and sufficient mechanical properties are exhibited even at 90 ° C (Fig. 3).

Since polylactic acid has poor mechanical properties at high temperatures as described above, various problems actually occur. For example, an automobile dashboard made by injection molding of polylactic acid softens at 60 to 70 ° C, so the vehicle interior temperature in summer is 80%.
There was a problem that it was easily deformed at ~ 100 ° C. Further, the fiber has the following problems. For example, when polylactic acid fiber is used as the warp yarn of a woven fabric, the yarn is glued for the purpose of improving the bundle gathering property and the weaving property, but when hot air drying is performed, the yarn is stretched by the tension applied to stretch the warp yarn. There was a problem of stretching. Further, when the false twist is applied to the polylactic acid fiber, the yarn is abruptly softened on the hot plate, so that the yarn is not twisted and the crimp property is inferior, and the yarn is broken on the hot plate. In some cases, false twisting itself becomes difficult. Furthermore, due to such troubles on the hot plate, the hot plate temperature can be raised up to 110 ° C at most, and the heat setting is insufficient, so that not only the crimping property is low but also the shrinkage rate of the yarn in boiling water. It was also difficult to reduce (boiling yield) to a practical level of 20% or less.

Furthermore, aliphatic polyesters generally have low melting points, and even the highest melting class of polylactic acid is 170
The temperature is about 0 ° C., for example, when a cloth made of polylactic acid fiber is ironed, there is a problem that holes are formed in the cloth due to melting of the polylactic acid fiber.

Due to the above problems, the application of aliphatic polyesters such as polylactic acid has been greatly limited. Therefore, an aliphatic polyester having improved mechanical properties and melting point at high temperature has been earnestly desired.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides a polyester resin composition containing an aliphatic polyester as a main component, which has never before been provided with excellent high-temperature mechanical properties and heat resistance.

[0010]

[Means for Solving the Problems] The above object is to copolymerize an aliphatic polyester with an aromatic polyester having 6 or more carbon atoms in a diol component or a diol component having 6 or more carbon atoms and / or a dicarboxylic acid component. It is achieved by a polyester resin composition characterized in that an aromatic polyester is blended in an amount of 5 to 40% by weight.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The aliphatic polyester referred to in the present invention means a polymer in which an aliphatic alkyl chain is linked by an ester bond, and examples thereof include polylactic acid, polyhydroxybutyrate, polybutylene succinate and polyglycol. Examples thereof include acids and polycaprolactone. this house,
As mentioned above, polylactic acid is most preferred. Moreover, polylactic acid means a polymer of lactic acid, and it is preferable that the optical purity of the L-form or D-form is 90% or more because the melting point is high. Further, components other than lactic acid may be copolymerized, or polymers other than polylactic acid, particles, additives such as flame retardants, antistatic agents and the like may be contained, as long as the properties of polylactic acid are not impaired. However, from the viewpoint of biomass utilization and biodegradability, it is important that the lactic acid monomer is 50% by weight or more as a polymer. Lactic acid monomer is preferably 75% by weight or more,
More preferably, it is 96% by weight or more. The molecular weight of the polylactic acid polymer is preferably 50,000 to 500,000 in terms of weight average molecular weight, because the balance between mechanical properties and moldability is good.

The aromatic polyester referred to in the present invention means a polyester having an aromatic ring in its main chain or side chain, for example, polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT), Examples thereof include polyhexamethylene terephthalate (PHT). However, Homo PET and Homo PB
Since T generally has low compatibility with aliphatic polyester,
Polymer blends with aliphatic polyesters were virtually impossible. Therefore, in order to enhance the compatibility between the aromatic polyester and the aliphatic polyester, it is important to introduce the aliphaticity into the main chain or side chain of the aromatic polyester. More specifically, it is important that the diol component of the aromatic polyester has 6 or more carbon atoms, or that the diol component and / or dicarboxylic acid component having 6 or more carbon atoms is copolymerized with the aromatic polyester. As the copolymerization component, a long-chain alkyl chain or a bisphenol A derivative is preferable. Examples of long-chain alkyl chains include alkylene diols and long-chain dicarboxylic acids. Here, examples of the alkylene diol include alkylene oxide polymers and oligomers such as polyethylene glycol, and diols having a large number of carbon atoms such as neopentyl glycol and hexamethylene glycol.
Examples of the long-chain dicarboxylic acid include adipic acid and sebacic acid. The copolymerization ratio is preferably 2 to 15 mol% or 2 to 15% by weight based on the total carboxylic acid amount in the case of diol and the total diol amount in the case of dicarboxylic acid. The diol component used in the present invention has an aromatic polyester having 6 or more carbon atoms or has 6 carbon atoms.
The aromatic polyester copolymerized with the above diol component and / or dicarboxylic acid will be simply referred to as "specific aromatic polyester" hereinafter for the sake of simplicity.

Further, since the melting point of the aliphatic polyester is generally 170 ° C. or less, in consideration of lowering the blending temperature as much as possible, the specific aromatic polyester is further copolymerized with isophthalic acid or the like to lower the melting point. Preferably. The melting point of the specific aromatic polyester is preferably 250 ° C. or lower, more preferably 230 ° C. or lower. However, the melting point of the specific aromatic polyester is preferably 170 ° C. or higher, more preferably 200 ° C., from the viewpoint of improving the heat resistance of the blended polyester resin or a molded product thereof in which the specific aromatic polyester is blended with the aliphatic polyester.
That is all.

In order to improve the moldability of the blended polyester resin obtained by blending the aliphatic polyester with a specific aromatic polyester and the dimensional stability of the molded product, the blended polyester resin is preferably crystalline. Therefore, the specific aromatic polyester to be blended is also preferably crystalline. If a melting peak can be observed in a differential scanning calorimeter (DSC) measurement, the polymer can be judged to be crystalline.

In consideration of the biodegradability of the blended polyester resin, the blending ratio of the specific aromatic polyester is 40% by weight based on the whole blended polyester resin.
It is important that: On the other hand, it is important that the blending ratio of the specific aromatic polyester is 5% by weight or more in view of improving the high temperature mechanical properties. The blending ratio of the particular aromatic polyester is preferably 15-30.
% By weight.

The reason why the high temperature mechanical properties are improved in the present invention is considered as follows. That is, it is generally considered that the aliphatic polyester such as polylactic acid has a weak interaction between the molecular chains and is likely to slip through the molecular chains, and thus has a high temperature mechanical property. Therefore, the strong interaction between the aromatic rings of a specific aromatic polyester strongly restrains the aliphatic polyester molecular chain, thereby supporting the aliphatic polyester molecular chain and improving the high-temperature mechanical properties of the blended polyester resin. It is thought to have been done.

For this purpose, it is preferable to utilize the crystallization of a specific aromatic polyester or a high T _g . Further, in order to sufficiently bring out the effect of crystallization or high T _g , it is preferable that the specific aromatic polyester and the aliphatic polyester are appropriately compatible with each other. Here, the term “moderately compatible” means that a specific aromatic polyester and an aliphatic polyester are phase-separated and have a so-called sea-island structure, but the aliphatic polyester penetrates into the specific aromatic polyester domain to some extent. Refers to what you are doing.
When such a unique blended state can be realized, the specific aromatic polyester can strongly bind the aliphatic polyester. This state can be confirmed by, for example, observing a slice of the blended polyester molded body with a transmission electron microscope (TEM) and comparing the charging ratio of the aliphatic polyester and the specific aromatic polyester with the sea-island ratio obtained by the TEM observation. You can Information can also be obtained from long-period measurement by small-angle X-ray scattering.

For example, 80 weight of polylactic acid shown in Example 1
%, The ratio of sea-island ratio obtained by TEM observation (Fig. 1) is 45 area%: 55 area%, and the sea-island ratio 81 area%: 19 area predicted from the charging ratio. The island ratio is significantly higher than that in the case of%, suggesting that polylactic acid penetrates into the copolymerized PET domain. Moreover, the long period of the copolymerized PET is usually about 10 nm, but in Example 1, it was about 2 times as large as 19 nm, and it can be interpreted that the copolymerized PET molecular chain partially sandwiches the polylactic acid molecular chain.

On the other hand, when the specific aromatic polyester and the aliphatic polyester are completely compatible at the molecular level,
Although formability good, or inhibit the crystallization of one another, T _g increases as the blend polyester with additive property T _g of decreases, restraint effect of specific aromatic polyesters as described above does not express, It may not be possible to improve the high temperature mechanical properties.

When the specific aromatic polyester and the aliphatic polyester are so-called incompatible, the aliphatic polyester cannot penetrate into the specific aromatic polyester domain, and the above-mentioned effects are not exhibited, The high temperature mechanical properties cannot be improved. Further, in an incompatible system, elastic behavior due to phase separation often appears strongly, and the moldability of the blended polyester is significantly impaired. In the past, homo-PET or homo-PBT and an aliphatic polyester were incompatible with each other, and polymer blending was virtually impossible.

As described above, in order to achieve both high-temperature mechanical properties and moldability, the so-called blended state has a sea-island structure, and the size of the island domain is 0.00 in terms of diameter.
It is preferable to have at least a portion having a thickness of 1 to 10 μm. Particularly in the case of fibers and films, it is preferable that at least a part of the island domain has a size of 0.001 to 1 μm in terms of diameter. Here, the island domain size can be measured by slicing the blended polyester resin or a molded product thereof and observing it by TEM. Further, it is also preferable from the viewpoint of improving moldability that a part of the blended polyester has a sea-island structure in which seas and islands are difficult to distinguish from each other and sea islands are disturbed. For example, the first embodiment described above.
Then, such a state can be observed in the fiber inner layer (Fig. 1).

Since the polyester resin composition of the present invention has excellent moldability, it can be used not only for ordinary resin molding such as injection molding, extrusion molding and blow molding but also for fiberization by spinning and film formation by film formation. It can also be applied to advanced melt molding. Normally, glass fiber blends are used to improve the performance of resins, but since the size of glass fibers is on the order of microns or more, when applied to fibers and films, the size is greater than the fiber diameter or film thickness. ,
It was virtually impossible to make yarn or film. However, in the blended polyester of the present invention, since the specific aromatic polyester to be blended is on the order of submicron or less, there is no such problem, and it can greatly contribute to the high performance of the aliphatic polyester and the expansion of its applications. . In particular,
Fibers and textile products are preferable because secondary processing using them is easy.

The fiber using the polyester resin composition of the present invention preferably has a strength at room temperature of 1.0 cN / dtex or more in order to keep the process passability and the mechanical strength of the product sufficiently high. The strength at room temperature is preferably 2.0 cN / dtex or more. Further, the elongation at room temperature of the fiber of the present invention is 15 to 70.
When it is%, the process passability in making a textile product is improved,
preferable. The elongation at room temperature is more preferably 25 to 50%.

As described above, the polylactic acid fiber, which is a typical example of the aliphatic polyester, has a strength-elongation curve shape (FIG. 3) close to a flow at 90 ° C. and a strength of 0.5 cN / dtex or less. However, with the fiber of the present invention, the strength can be increased to 0.7 cN / dtex or more even at 90 ° C., and the creep property can be greatly improved. As the creep property, the elongation at 90 ° C. under 0.5 cN / dtex stress is used as an index, but in the fiber of the present invention, this can be set to 15% or less. Here, the elongation at 90 ° C under 0.5 cN / dtex stress is obtained by performing a tensile test of the fiber at 90 ° C and reading the elongation at stress 0.5 cN / dtex in the strength-elongation curve diagram. Can be done (Fig. 2). 0.5cN / dtex at 90 ℃
The elongation under stress is preferably 10% or less. Also, 9
When the strength at 0 ° C. is 0.7 cN / dtex or more, the strength at high temperature of the fiber product made of polylactic acid fiber can be improved, which is preferable. The strength at 90 ° C is more preferably 1.0 cN / dtex or more.

In the fiber of the present invention, when the boiling point is 0 to 20%, the dimensional stability of the fiber and the fiber product is good and it is preferable. The boiling point is preferably 3-10%.

Regarding the cross-sectional shape of the fiber of the present invention, it is possible to freely select a round cross section, a hollow cross section, a multilobe cross section such as a trilobal cross section, and other irregular cross sections. Also,
The form of the fiber is not particularly limited such as long fiber and short fiber, and in the case of long fiber, it may be multifilament or monofilament.

The fibers of the present invention can be in the form of various textile products such as woven fabrics, knitted fabrics, non-woven fabrics and thermocompression molded products such as cups and boards.

The polyester resin composition of the present invention can be suitably used for cases, boards, daily life materials, vehicle materials, industrial materials and the like in resin molding applications. Also,
In textile applications, not only raw yarn for false twisting, clothing such as shirts, blouson and pants, but also clothing materials such as cups and pads, curtains, carpets, mats, furniture interiors, vehicle interiors, belts, nets, etc. It can also be suitably used for industrial materials such as ropes, heavy cloth, bags, sewing threads, felts, non-woven fabrics, filters and artificial grass. In addition, in the use of films and sheets, it can be suitably used as a packaging material, a label, a living material such as a wrap film, and an industrial material such as a separator.

[0029]

EXAMPLES The present invention will be described in detail below with reference to examples. The following methods were used as the measuring methods in the examples.

A. Tetrahydrofuran was mixed with a chloroform solution of a weight average molecular weight sample of the aliphatic polyester to prepare a measurement solution. This was measured by GPC, and the weight average molecular weight was calculated in terms of polystyrene.

B. Intrinsic viscosity of aromatic polyester [η] Measured in orthochlorophenol at 25 ° C.

C. Strength and elongation at room temperature At room temperature (25 ℃), initial sample length = 200mm, tensile speed = 2
The load-elongation curve was determined under the conditions specified in JIS L1013 at 00 mm / min. Next, divide the load value at break by the initial fineness,
The strength was taken as the strength, the elongation at break was divided by the initial sample length, and the strength-elongation curve was obtained as the elongation.

D. Elongation measurement temperature at 90 ° C. under 0.5 cN / dtex stress At 90 ° C., a strength-elongation curve was obtained in the same manner as in the above C.
The elongation at 5 cN / dtex was read, and the elongation was measured at 90 ° C under 0.5 cN / dtex stress.

E. Strength measurement at 90 ° C. At a temperature of 90 ° C., a strength / elongation curve was obtained in the same manner as in D, and the load value was divided by the initial fineness to obtain the strength at 90 ° C.

F. Evaporation / evaporation (%) = [(L0-L1) / L0)] × 100 (%) L0: Skein the drawn yarn and measure the original length L1: L0 of the skein measured under an initial load of 0.09 cN / dtex Skein skeins were treated in boiling water for 15 minutes in a substantially load-free state, and after air drying, skein length G. under an initial load of 0.09 cN / dtex. Was measured a T _g and a melting point in the 2nd the run with a T _g and a melting point manufactured by PERKIN ELMER DSC-7 of the polymer. At this time, the sample weight is 10 mg, and the heating rate is 16 ° C.
/ Minute.

H. Observation of blended state of blended polyester An ultrathin section was cut in the cross-sectional direction of the blended fiber, and the blended state of the polyester was observed with a transmission electron microscope (TEM).

TEM apparatus: H-7100FA manufactured by Hitachi Ltd. Condition: Accelerating voltage 100 kV Here, as the size of the island domain, it was assumed that the domain was a circle, and the size was calculated by converting the area into a diameter. The sea-island ratio was calculated using image analysis software.

I. Wide-angle X-ray diffraction Rigaku Denki's 4036A2 type X-ray diffractometer was used to measure the diffraction intensity in the equatorial line direction under the following conditions.

X-ray source: Cu-Kα ray (Ni filter) Output: 40 kV × 20 mA Slit: 2 mm φ-1 ° -1 ° Detector: Scintillation counter counting recorder: RAD-C type step scan manufactured by Rigaku Denki: 0.05 ° Step integration time: 2 seconds J. Small-angle X-ray scattering A small-angle X-ray scattering photograph was taken using an RU-200 type X-ray generator manufactured by Rigaku Denki.

X-ray source: Cu-Kα ray (Ni filter) Output: 50kV × 150mA Slit: 0.5mmφ Camera radius: 405mm Exposure time: 300 minutes Film: Kodak DEF-5 And the distance between scattering points r ( mm) to calculate the long period using the Bragg equation.

J = λ / 2sin [{tan ⁻¹ (r / R)} / 2] J: long period (nm) R: camera radius (405 mm) λ: wavelength of X-ray (0.15418 nm) K. Crimping characteristics of false-twisted yarn, CR value False-twisted yarn was squeezed, treated in boiling water for 15 minutes in a substantially load-free state, and air-dried for 24 hours. A load equivalent to 0.088 cN / dtex (0.1 gf / d) was applied to this sample and the sample was immersed in water, and the skein length L'0 was measured after 2 minutes. Then in water 0.00
Except for the load equivalent to 88 cN / dtex, the load was changed to a small load equivalent to 0.0018 cN / dtex (2 mgf / d), and the skein length L'1 was measured 2 minutes later. Then, the CR value was calculated by the following formula.

CR (%) = [(L'0-L'1) / L'0] × 100 (%) Number of crimps of crimped yarn The number of crimps was counted after shrinking the crimped yarn in hot water at 100 ° C in a substantially load-free state.

Example 1 As a specific aromatic polyester, 6 mol% of bisphenol A ethylene oxide adduct and 6 parts of isophthalic acid were used.
Copolymer PET with an intrinsic viscosity of 0.65 that was copolymerized with mol% (melting point 220 ° C)
And a homopoly L lactic acid having a weight average molecular weight of 150,000 (optical purity 99% L lactic acid) were melt-blended at 235 ° C. using a biaxial kneader to obtain a blended polyester chip. At this time, the blending ratio of the copolymerized PET was set to 20% by weight based on the blended polyester. The T _g of this blended polyester chip was 61 ° C., which was almost the same as 60 ° C. of homopoly L lactic acid. This blended polyester chip is dried, melt-spun at a spinning temperature of 235 ° C., the spun yarn 5 is cooled and solidified by a chimney 4 with a cooling air of 25 ° C., and then a fiber oil agent is applied by a focusing oil supply guide 6. Then, the yarn was entangled by the entanglement guide 7 (FIG. 4). There was no problem with the melt spinnability of this, and there was no yarn breakage after winding 100 kg. After that, it was taken up by an unheated first take-up roller 8 at a peripheral speed of 1500 m / min, and then wound up by an unheated second take-up roller 9. This thread the temperature of the first roller 13
After preheating at 90 ℃, stretched 2.8 times, the second roller 14
Heat-set at 130 ° C with a non-heated third roller 15
The filament was wound up through to obtain a stretched yarn 16 of 84 dtex, 36 filaments and a round cross section. There is no problem with the stretchability here,
There was no yarn breakage after winding 100 kg.

The strength-elongation curve of the obtained fiber at 90 ° C. is shown in FIG. 2 and the physical properties are shown in Table 1. The yield stress is higher than that of the conventional polylactic acid fiber (Comparative Example 1) and the 90 ° C. The mechanical properties were greatly improved. In addition, wide-angle X-ray diffraction was performed, and it was confirmed that the PET portion was oriented and crystallized. Furthermore, when the long period was measured by small-angle X-ray scattering, it was found to be 19 nm, which was a large increase compared with 10 nm of the copolymer PET single yarn (Reference Example 1). In addition, TEM observation of the cross section of the yarn revealed that it had a uniformly dispersed sea-island structure as shown in FIG. 1, and the domain size of the island was in the submicron order in terms of diameter. Furthermore, there was a part where the sea island was reversed, suggesting that the compatibility was excellent. The sea-island ratio calculated by image analysis is 45 areas.
%: 55 area%, 81 area% predicted from the charging ratio: 1
The island ratio is significantly larger than 9 area%, and polylactic acid is a copolymerized PE.
It is considered that the apparent insular ratio increased by invading the T domain. Furthermore, since the long-period structure of the PET portion is 19 nm, which is about twice as large as that of the copolymerized PET alone yarn, which is 10 nm, it was considered that the PET molecular chain sandwiches the polylactic acid molecular chain and strongly binds it. .

Further, this fiber was cylindrically knitted and subjected to an ironing test at 180 ° C., but no hole was formed in the tubular knitted fabric, and the heat resistance was remarkably higher than that of the conventional polylactic acid fiber (Comparative Example 1). It was improving.

Reference Example 1 The copolymer PET used in Example 1 was used in Example 1 at a spinning temperature of 280 ° C.
After melt spinning, draw ratio 3.0 times, draw temperature 9
Stretching and heat treatment at 0 ℃, heat set temperature 130 ℃, 84dtex, 36
A filament cross-section stretched yarn was obtained. When the small-angle X-ray scattering of this was measured, the long period was 10 nm.

Example 2 Example 1 except that the blending ratio of copolymerized PET was 35% by weight.
In the same way, spinning and drawing are performed, 84dtex, 72 filaments,
A drawn yarn having a round cross section was obtained. The physical properties of this are shown in Table 1,
Compared with the conventional polylactic acid fiber (Comparative Example 1), the mechanical properties at 90 ° C were significantly improved.

Example 3 Example 1 except that the blending ratio of copolymerized PET was 10% by weight.
In the same manner as above, spinning and drawing were carried out to obtain drawn yarn having 84 dtex, 144 filaments, and round cross section. The physical properties are shown in Table 1, and the mechanical properties at 90 ° C were significantly improved as compared with the conventional polylactic acid fiber (Comparative Example 1).

Example 4 As a specific aromatic polyester, 4% by weight of polyethylene glycol having a molecular weight of 1000 and 6 mol% of isophthalic acid were used.
Copolymerized PET with a limiting viscosity of 0.55 (melting point 240 ° C) was used and melt-blended with homopoly L-lactic acid (optical purity 99% L-lactic acid) having a weight average molecular weight of 200,000 at 250 ° C using a twin-screw kneader. A blended polyester chip was obtained. At this time, the blending ratio of the copolymerized PET is 20 with respect to the blended polyester.
It was set to% by weight. This blended polyester chip was dried and spun and stretched in the same manner as in Example 1 except that the spinning temperature was 250 ° C to obtain a stretched yarn of 164 dtex, 48 filaments, and a round cross section. The physical properties of this are shown in Table 1, and the mechanical properties at 90 ° C. were significantly improved as compared with the conventional polylactic acid fiber (Comparative Example 1).

Example 5 10 mol% of adipic acid as a specific aromatic polyester,
Further, copolymerized PET (melting point 225 ° C.) having an intrinsic viscosity of 0.65 in which 6 mol% of isophthalic acid was copolymerized was melt-blended with the polylactic acid used in Example 4 at 240 ° C. using a twin-screw kneader, and the spinning temperature was adjusted. Was drawn and stretched in the same manner as in Example 4 except that the temperature was 240 ° C. to obtain a stretched yarn with 84 dtex, 48 filaments and a round cross section. At this time, the blending ratio of the copolymerized PET was set to 20% by weight based on the blended polymer. The physical properties are shown in Table 1, and the mechanical properties at 90 ° C were significantly improved as compared with the conventional polylactic acid fiber (Comparative Example 1).

Comparative Example 1 The polylactic acid used in Example 1 was dried, melt-spun at 220 ° C., and the spun yarn 5 was cooled and solidified by the chimney 4 with cooling air at 25 ° C. An oil agent for fibers was applied by the focusing refueling guide 6, and the yarn was entangled by the entanglement guide 7 (FIG. 4). After that, the 1st unheated peripheral speed of 1500m / min
After the yarn was taken up by the take-up roller 8, the yarn was wound up through the non-heated second take-up roller 9. This unstretched yarn 11 is preheated at a temperature of 90 ° C. for the first roller 13, then drawn 2.8 times, heat set at 130 ° C. for the second roller 14, and wound up through a non-heated third roller 15 to obtain 84 dte.
A drawn yarn with x, 24 filaments and a round cross section was obtained. 90 of this
The strength and elongation curve at ℃ is shown in Fig. 2 and the physical properties are shown in Table 1.
The mechanical properties at Further, this fiber was knitted and subjected to an ironing test at 180 ° C., but it was found that the polylactide fiber had a large hole in the knitted fabric and the heat resistance was poor.

Comparative Example 2 A biaxial kneader was used in the same manner as in Example 4 except that homo-PET having an intrinsic viscosity of 0.55 was used as the aromatic polyester, and 280 ° C.
Were melt-blended to obtain a blended polyester chip. Here, the blending ratio of homo-PET was set to 10% by weight based on the blended polyester. However, due to the poor compatibility between homo-PET and polylactic acid, a clean gut could not be pulled and the chip quality was poor. Further, since the melt blending temperature was too high, smoke was observed due to decomposition of polylactic acid. The blended polyester chips are dried and the spinning temperature is 280
Melt spinning was carried out in the same manner as in Example 4, except that homo PE
Due to the poor compatibility of T and polylactic acid, rubber-like elastic behavior was strongly exhibited, and the spinnability was poor and spinning was impossible. When TEM observation was performed by slicing the discharged product obtained here,
Homo PET and polylactic acid were completely phase separated.

Comparative Example 3 Homo PBT having an intrinsic viscosity of 0.85 was used as an aromatic polyester and melt-blended with polylactic acid at 250 ° C. in the same manner as in Comparative Example 2. Here, the blend ratio of homo PBT was set to 10% by weight based on the blend polyester. However, as in Comparative Example 3, the compatibility between homo PBT and polylactic acid was poor, so that a clean gut could not be pulled and the chip quality was poor. The blended polyester chips are dried and the spinning temperature is 250 ° C.
Was melt-spun in the same manner as in Comparative Example 3, but homo PBT was used.
Due to the poor compatibility of polylactic acid, rubber-like elastic behavior was strongly exhibited, and the spinnability was poor and spinning was impossible. When the discharged product obtained here was sliced and observed by TEM, homo-PET and polylactic acid were completely phase-separated.

Comparative Example 4 An example in which polymethylmethacrylate (PMMA) is blended with polylactic acid as a high T _g polymer which is completely compatible with polylactic acid at the molecular level is shown. PMMA (SUMIPEX LG21 manufactured by Sumitomo Chemical Co., Ltd., T _g = 105 ° C.) and the dried polylactic acid used in Example 1 were melt-blended at 220 ° C. using a biaxial kneader to obtain a blended polymer chip. At this time, the blending ratio of PMMA was 50% by weight based on the blended polymer. The T _g of this blended polymer chip is 75 ℃ and that of homopoly L lactic acid is 60 ℃.
Greatly improved compared to. The blended polymer chips were dried and melt-spun in the same manner as in Example 1 except that the spinning temperature was 220 ° C. The undrawn yarn 11 wound up is taken up by the first roller 13
After preheating at a temperature of 90 ° C, it is drawn 1.7 times, heat-set at 130 ° C with the second roller 14, and wound up through the unheated third roller 15, 100dtex, 36 filaments, a stretched yarn 16 with a round cross section. Got The physical properties of this yarn are shown in Table 1.
It had low room temperature strength and low mechanical properties at 90 ° C. Thus, in the completely compatible system is insufficient T _g improve blend polymer satisfied additive property of T _g, and did not necessarily lead to the improvement of high-temperature mechanical properties even in a high T _g.

Comparative Example 5 Aliphatic polyester carbonate having a weight average molecular weight of 190,000 (14% carbonate unit) polymerized by the method described in Example 2 of JP-A-2000-109664 and dried optical purity 99%,
Homopoly L lactic acid having a weight average molecular weight of 200,000 was melt blended at 240 ° C. using a biaxial kneader to obtain a blended polymer chip. At this time, the blending ratio of the aliphatic polyester carbonate was 50% by weight based on the blended polymer. The T _g of this blended polymer chip was 65 ° C. This blended polymer chip was dried and melt-spun in the same manner as in Example 4 except that the spinning temperature was 240 ° C. However, the compatibility of the aliphatic polyester carbonate and polylactic acid was poor, and thus the yarn was frequently broken. The unstretched yarn that has been wound up is preheated at a temperature of 90 ° C for the first roller 13 and then stretched 1.5 times,
Roller 14 sets the heat at 130 ℃,
It was wound around a roller 15 to obtain a drawn yarn 16 having a filament of 100 dtex, 36 filaments and a round cross section, but the drawability was poor and the yarn was frequently broken. The physical properties of this yarn are shown in Table 1, but the room temperature strength was low and the mechanical properties at 90 ° C were also poor.

[0056]

[Table 1] Example 6 To the polylactic acid fiber excellent in high temperature mechanical properties obtained in Example 1,
Friction disk false twisting was performed at a draw ratio of 1.1 times, a heater temperature of 130 ° C., and a processing speed of 400 m / min. There was no problem in workability and no yarn breakage or fluff occurred. In addition, the CR value, which is an index of crimp characteristics, was 28%, which was sufficient crimp as a false twist textured yarn. Further, the boiling point was 5%, which was sufficiently low.

Example 7 Melt spinning was carried out in the same manner as in Example 1 at a spinning speed of 3000 m / min to obtain a highly oriented undrawn yarn. The draw ratio is 1.5 times,
Friction disk false twisting was performed at a heater temperature of 130 ° C and a processing speed of 400 m / min. There is no problem in workability, thread breakage,
No fluff was generated. In addition, CR, which is an index of crimp characteristics,
The value was 25%, which was sufficient crimp for false twisted yarn.
Further, the boiling point was 5%, which was sufficiently low.

Comparative Example 6 The conventional polylactic acid fiber obtained in Comparative Example 1 was added with a draw ratio of 1.3 times,
Although friction disk false twisting was performed at a heater temperature of 130 ° C and a processing speed of 400 m / min, the yarn was slack on the hot plate and the yarn could not be applied. Next, when the hot plate temperature was lowered to 110 ° C. and processing was performed, there was still a problem in threading, but it was possible to wind the thread. However, it is an index of crimp characteristics
The CR value was 10% and there was almost no crimp. Furthermore, the boiling point was 25%, which was too high due to insufficient heat setting.

Example 8 A plain weave was produced by using the yarn obtained in Example 1 as a warp yarn and a weft yarn. The warp was pasted and dried at 110 ° C., but no trouble of stretching the yarn occurred. The plain weave obtained was scoured at 60 ° C. according to a conventional method and then subjected to intermediate setting at 140 ° C. Further, it was dyed at 110 ° C. according to a conventional method. The obtained cloth had a squeaky feeling and a soft feeling, and had an excellent texture for clothing.

Comparative Example 7 A plain weave was produced by using the yarn obtained in Comparative Example 1 as a warp and a weft. The warp yarn was glued and dried at 110 ° C, but the yarn was stretched and could not be dried.

Example 9 The blend polymer obtained in Example 1 was melt-spun and
The tow was collected at 1600 m / min and stretched 4 times in a 90 ° C water bath. Then, after passing through the crimper, cut it and keep it at 90 ° C.
Was subjected to a relaxation heat treatment to obtain a cut fiber with a single yarn fineness of 6 dtex and a fiber length of 60 mm. This was thermocompression-molded at 220 ° C. to obtain a board having a thickness of 3 mm. This was cut into a width of 2 cm, the distance between the fulcrums was set to 50 cm, a weight of 1 kg was placed on the center, and it was held at 100 ° C for 20 minutes. After cooling, the weight was removed and the residual warp of the board was observed, but no warp was found.

Comparative Example 8 Example 9 was repeated except that the polylactic acid used in Comparative Example 1 was used.
I got a board in the same way as. When the warp was observed in the same manner as in Example 9, a remarkable residual warp was found.

Example 10 The blended polyester chips obtained in Example 1 were dried and melt-spun at 240 ° C. At this time, the mouthpiece discharge hole was Y-shaped, and the mouthpiece discharge hole length was 0.5 mm. The spun yarn is drawn at 800 m / min, then drawn in two steps under the conditions of the first step draw ratio of 1.4 times and the total draw ratio of 4.0 times, and further crimped using a jet nozzle before 450 dtex. , 90 filament filament bulky yarn was wound up. The number of crimps was 15 / m, indicating a good crimp.

Comparative Example 9 Example 1 was repeated except that the polylactic acid used in Comparative Example 1 was used.
A bulky processed yarn for carpet was obtained in the same manner as in No. 0. The number of crimps was 6 / m, which was an insufficient crimp.

Example 11 The blended polyester chips obtained in Example 1 were dried, charged into a single-screw extruder equipped with a screw having a diameter of 150 mm and heated to 240 ° C., melt-extruded, and fiber-sintered. After filtering in a stainless metal filter, it was discharged in a sheet form from a T die, and the sheet was adhered and solidified at a draft ratio of 3 at a speed of 20 m / min and rapidly cooled on a cooling drum having a surface temperature of 25 ° C. An unoriented unstretched film was obtained.

Subsequently, the unstretched film was stretched 3.5 times in the machine direction of the film at a temperature of 85 ° C. by using a longitudinal stretching machine consisting of a plurality of heated roll groups and utilizing the peripheral speed difference of the rolls. It was stretched at a ratio. After that, both ends of this film were held by clips, introduced into a tenter, and stretched in the width direction of the film at a stretching temperature of 85 ° C. and a stretching ratio of 3.0 times. Then 1
After heat treatment at a temperature of 60 ℃, after cooling to room temperature,
The film edge was removed to obtain a biaxially oriented film having a thickness of 20 μm.

The longitudinal strength of this is 100 MPa and the lateral strength is
The heat shrinkage at 130 MPa was 0.5% in the longitudinal direction, and the heat shrinkage in the lateral direction was 0.5%. Both strength and shrinkage were sufficient. The heat shrinkage was determined from the dimensional change when left in an atmosphere of dry heat of 120 ° C for 30 minutes under no load. The strength at 90 ℃ is 45MP in the vertical direction.
a, the transverse direction was 50 MPa, which was sufficient.

Comparative Example 10 Example 1 was repeated except that the polylactic acid used in Comparative Example 1 was used.
Film formation was carried out in the same manner as in 1, but when heat treatment was carried out at 160 ° C., breakage thought to be caused by partial melting of polylactic acid occurred, and film formation was substantially impossible. Therefore, the heat treatment temperature
The film was formed by lowering the temperature from 160 ° C to 140 ° C to obtain a biaxially oriented film having a thickness of 20 µm.

The longitudinal strength of this is 110 MPa, and the lateral strength is
The heat shrinkage was 150MPa, the longitudinal heat shrinkage was 2.5%, and the transverse heat shrinkage was 2.5%. Although the strength was sufficient, the shrinkage became large. Furthermore, the strength at 90 ℃ is 10MPa in the vertical direction and 1 in the horizontal direction.
The high temperature mechanical properties of 3MPa were extremely inferior.

Example 12 The blended polyester chips obtained in Example 1 were dried and charged into a single-screw extruder equipped with a screw having a diameter of 150 mm heated to 240 ° C., a cylinder temperature of 240 ° C., and a mold temperature. Injection molding was performed at 40 ° C. to prepare a test piece having a length of 100 mm, a width of 20 mm, and a thickness of 3 mm. The ambient temperature was 120 ° C, and a weight of 1 kg was placed on the fulcrum at a distance of 80 mm for 30 minutes, but there was no residual deformation when cooled to room temperature.

Comparative Example 11 A test piece was produced in the same manner as in Example 12 except that the polylactic acid used in Comparative Example 1 was used and the extruder temperature and the cylinder temperature were 220 ° C. When the ambient temperature was 120 ° C and a weight of 1 kg was placed on the fulcrum at a distance of 80 mm for 30 minutes, significant residual deformation was observed when cooled to room temperature.

Example 13 Polylactic acid and polybutylene succinate used in Example 1 as an aliphatic polyester (Showa High Polymer "Bionore")
A blended polyester chip having a melting point of 118 ° C.) blended in a ratio of 3: 1 was blended with 20% by weight of copolymerized PET in the same manner as in Example 1 to prepare a blended polyester chip at 235 ° C. Then, in the same manner as in Example 1, 84dtex, 36 filaments, a drawn yarn having a round cross section was obtained. Its strength at 90 ° C is 0.
The elongation under stress of 7cN / dtex and 0.5cN / dtex was 12%, which had sufficient high temperature mechanical properties.

Example 14 The procedure of Example 1 was repeated except that the polybutylene succinate of Example 13 was used as the aliphatic polyester.
A drawn yarn of dtex, 36 filaments, round cross section was obtained. Of this
The strength at 90 ℃ was 0.7 cN / dtex, and the elongation under stress of 0.5 cN / dtex was 14%, which was sufficient for high temperature mechanical properties.

Comparative Example 12 Polybutylene succinate of Example 13 was melt-spun at 220 ° C. in the same manner as in Comparative Example 1, and further stretched / heat-treated at a draw ratio of 2.2 times, a stretching temperature of 75 ° C. and a heat setting temperature of 85 ° C. A 84dtex, 36 filament, round drawn yarn was obtained. Its strength at 90 ℃ was 0.2cN / dtex, which was extremely inferior in high temperature mechanical properties.

[0075]

EFFECTS OF THE INVENTION By using a polyester resin composition characterized in that a specific aromatic polyester is blended with the aliphatic polyester of the present invention, the disadvantages of the aliphatic polyester are high temperature mechanical properties and heat resistance. The properties can be significantly improved, and the application of the aliphatic polyester can be greatly expanded.

[Brief description of drawings]

FIG. 1 is a TEM photograph showing a blended state of a specific aromatic polyester and an aliphatic polyester in the blended polyester of the present invention.

FIG. 2 is a diagram showing strength-elongation curves at 90 ° C. of the present invention and conventional polylactic acid fibers.

FIG. 3 is a view showing strength / elongation curves of conventional polylactic acid fiber and nylon 6 fiber.

FIG. 4 is a view showing a spinning and drawing device.

[Explanation of symbols]

1: Spin block 2: Spin pack 3: Base 4: Chimney 5: Thread 6: Focused refueling guide 7: Confounding guide 8: First take-up roller 9: Second take-up roller 10: Winding thread 11: Undrawn yarn 12: Feed roller 13: First roller 14: Second roller 15: Third roller 16: drawn yarn

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F071 AA43 AA45 BA01 BB05 BB06                       BB08 BC01                 4J002 CF031 CF052 CF062 CF072                       CF181 CF191 GK01                 4L035 BB31 BB89 BB91 EE20                 4L036 MA05 RA04 UA25

Claims (9)

[Claims] 1. An aromatic polyester in which a diol component has 6 or more carbon atoms or an aromatic polyester in which a diol component having 6 or more carbon atoms and / or a dicarboxylic acid component is copolymerized with an aliphatic polyester is 5 to 40 wt. % Blended polyester resin composition. 2. An aromatic polyester having a carbon number of 6 or more in the diol component or an aromatic polyester in which a diol component having a carbon number of 6 or more and / or a dicarboxylic acid component is copolymerized is crystalline and has a melting point of 170 to 170. The polyester resin composition according to claim 1, which has a temperature of 250 ° C. 3. The polyester resin composition according to claim 1 or 2, wherein the aliphatic polyester is polylactic acid. 4. A blended state of an aliphatic polyester and an aromatic polyester having a diol component having 6 or more carbon atoms or an aromatic polyester obtained by copolymerizing a diol component having 6 or more carbon atoms and / or a dicarboxylic acid component is sea island. The polyester resin composition according to any one of claims 1 to 3, wherein the polyester resin composition has a structure, and has at least a portion having an island size of 0.001 to 10 µm in terms of diameter. 5. A molded article comprising at least a part of the polyester resin composition according to any one of claims 1 to 4. 6. The molded product according to claim 5, wherein the molded product is a fiber or a fiber product. 7. The fiber according to claim 6, wherein the fiber is a crimped yarn. 8. The molded product according to claim 5, wherein the molded product is a film or a sheet. 9. The molded product according to claim 5, which is an injection molded product, an extrusion molded product or a blow molded product.