JPS59106515A - Manufacture of polyester fiber - Google Patents

Abstract

PURPOSE:To manufacture a high-quality hot-melt fiber which can be dried in the drying process without causing the fusing of powder, by drying particles of a low-crystalline polyester copolymer at a temperature within a specific range, and spinning under melting. CONSTITUTION:A polyester copolymer having low crystallinity and composed mainly of ethylene terephthalate or butylene terephthalate and copolymerized with a dicarboxylic acid or hydroxycarboxylic acid component other than terephthalic acid, is pulverized until >=90wt% of the copolymer becomes 16-12 mesh particles. The particles are dried by heating at a temperatre satisfying the formula [Tg is glass transition temperature ( deg.C) of the copolymer] and melted and spun at a melt viscosity of 500-6,200 poise.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming modified polyester fibers, particularly for drying low crystalline polymers to form fibers.

In recent years, polyester fiber products have been actively researched to improve their performance through improvements in high-order processing and spinning processes, as well as to modify them through copolymerization.

Polyester fibers, especially polyethylene terephthalate (
PET) has an excellent texture and chemical properties.

Although it is used in a wide range of fields due to its mechanical properties, polyester mainly composed of PET'i is attracting attention as a heat-adhesive fiber for use in cotton filling, paper making, and nonwoven fabrics. It is essential that heat-adhesive fibers exhibit sufficient adhesion when heat-treated by blending, blending, or interweaving with a main material such as polyester fiber. Therefore, in order to impart thermal bonding ability to polyester fibers, the bonding ability must be developed at a heat treatment temperature lower than the melting point of the main material. The method of lowering the melting point of polyester is
Copolymerization techniques are common.

However, it is generally known that increasing the copolymerization component lowers the melting point and also lowers the crystallinity of the polymer.

If polyester particles obtained by a batch polymerization method are spun without drying, they will be hydrolyzed by the water contained in the polymer particles, leading to deterioration in quality. Therefore, the necessity of drying is shown in many documents, such as Hisashi Mizutani's [Synthetic Fibers (1) Nylon and Tetron JP 312], and it is necessary to dry polyester chips particularly strictly. It is stated that if it is melted while containing water, there is a strong tendency for depolymerization to occur due to an equilibrium reaction, and therefore it is necessary to dry under reduced pressure to reduce the water content to 0.005 mole or less per mole of basic unit.

Here, the polyester of the present invention has low crystallinity or poor quality as revealed by differential scanning calorimetry and has a low melting point. Therefore, when the polyester is dried using a conventional drying recipe, the polymer melts and adheres to the interior of the dryer, or the polymer particles adhere to each other and form agglomerates, making spinning impossible.

The present invention is a method for forming fibers by drying low-crystalline polyester and supplying it to a spinning process while maintaining the shape of polymer particles whose 90 weight upwind is greater than 16 meshes and smaller than 8 meshes. .

That is, the present invention provides a low crystalline polyester polymer copolymerized with at least one aromatic or aliphatic dicarboxylic acid or oxycarboxylic acid component other than terephthalic acid in a polyester mainly composed of polyethylene terephthalate or polybutylene terephthalate. , the drying temperature (TD: °C) of the polymer particles whose 90 weight upwind of the entire polymer is greater than 16 mesh and smaller than 12 mesh/unit.
The relationship between the temperature and the glass transition temperature (Tg: °C) of the polymer is as follows: % After drying at a temperature that satisfies all requirements,
This is a method for producing polyester fiber, characterized by performing melt spinning at a melt viscosity [η] of 200 poise or less.

The drying method of the present invention allows drying without damaging the shape of the particulate polymer.

If the drying temperature is higher than 7g+15°C, the polymer particles will adhere and the polymer will become a hard lump after drying, making it difficult to feed it to the spinning site. Further, if the drying temperature is lower than 30° C., the drying time will be extremely long and the drying will not be carried out sufficiently, so that the polymer will be hydrolyzed during spinning, which is not preferable.

The preferred drying temperature is 45°C≦TD≦Tg+8°C.

The dryer used for drying may be a tray type, rotary type, fluidized bed type, or moving bed type, and drying can be performed by a heated air blowing method, a heated inert gas blowing method, or a reduced pressure method. It is preferable to dry by blowing heated air or inert gas using a rotary dryer, or under reduced pressure.

The rotation speed of the rotary dryer is suitably 1 to 12 rpm, preferably 2 to 8 rpm.

During drying, the polymer particle temperature is 30°C≦TD≦Tg+1
It is desirable to avoid local heating by controlling the entire temperature in the dryer to 5° C. and not causing a temperature difference between the polymer particles. Localized heating is undesirable because it induces agglomeration of the polymer particles between the polymer particles or on the inner wall of the dryer.

Drying is preferably carried out by blowing heated gas or under reduced pressure. It is efficient and preferable to blow in or apply reduced pressure at the time the polymer is charged into the dryer. The moisture content of the polymer particles subjected to drying is preferably 0.05% or less.

When the polymerized molten polymer is cooled with water and cut into particles, it is preferable to blow dry nitrogen gas in front of the cutter to evaporate moisture. Nitrogen gas is suitably 50L/-in to 1501/=n per 100g of polymer and 80L/s
in~1207. /Female is preferred.

The drying time is 3 hours to 25 hours after the specified temperature is reached, but a drying time of 8 hours or more is recommended to avoid the adverse effects of hydrolysis and to avoid the adverse effects of the drying time at a drying temperature of 60°C≦TD<7g+15°C. There are also few.

By applying all of the drying methods described above, 90% by weight or more of the dried polymer particles are larger than 16 meshes and smaller than 8 meshes, and the dried polymer particles can be stably transferred to the spinning field. can be supplied.

The dried polymer is fed to a spinning machine with one pressure melter and one extruder to obtain spun yarn, but even if the polymer particles are continuously fed by the drying method of the present invention, there is no possibility of clogging in the piping. , it is possible to obtain fibers with good quality without the formation of bridges and with stable quality.

What is the melt viscosity in melt spinning in the present invention?

Not only single fiber type, but also bimetal type composite fiber, sea-island type composite fiber, and concentric core-sheath type composite fiber can be easily produced.It is characterized by excellent ability to form composite fiber with PET in particular, and has a melt viscosity that allows stable fiber formation. and 500 poise≦η
The range is preferably ≦6200 poise, more preferably 1
100 poise≦η≦4500 poise. If this range is within this range, the decrease in melt viscosity due to thermal history during fiber formation can be sufficiently compensated for and stable fiber formation can be achieved, but if the melt viscosity is less than 500 poise, stable fiber formation cannot be achieved and spinning Occasionally, there are frequent occurrences of drips. Furthermore, if the melt viscosity exceeds 6200 voids, spinning becomes difficult, especially when combined with PET.

The copolymerization amount of at least one aromatic or aliphatic dicarboxylic acid or oxycarboxylic acid component other than terephthalic acid in the present invention is preferably 25 molar or more and less than 50 molar. If the copolymerization amount is within this range, the fiber forming ability will be satisfied and the thermal adhesive function can be expressed at low temperatures, but if the copolymerization component is less than 25 mol, the thermal adhesive function cannot be expressed at low temperatures. Moreover, when the copolymerization component is 50 molar or more,
This is not preferable because it makes it difficult to make particles of the polymer and form fibers.

The copolymerization components are P-hydroxy-7benzoic acid, isophthalic acid, 4.4'-diphenylmethane dicarboxylic acid, 4.4
'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, 1,2'-diphenoxyethane-
P, P' dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, adipic acid, and sebacic acid are applicable, and among them, inphthalic acid component is preferred. The isophthalic acid component is
It has good compatibility with the PET component and shows favorable reactivity, and P
As a heat-adhesive fiber containing ET'i as the main component, it exhibits sufficient heat-adhesive ability.

The main component of the polyester fiber of the present invention is preferably PET, but polybutylene terephthalate can also be used effectively.

In the synthesis of the polyester of the present invention, a well-known catalyst,
A coloring inhibitor, an ether bond by-product inhibitor, an antioxidant, a flame retardant, an antistatic agent, etc. can be used as appropriate. The polyester may also contain fine particle compounds such as silicon compounds, titanium compounds, and carbon.

As described in detail above, the present invention provides a method for forming fibers from a low-crystalline modified polyester copolymerized with at least one aromatic or aliphatic dicarboxylic acid or oxycarboxylic acid component other than terephthalic acid. , which provides valuable insight.

The present invention will be specifically explained below with reference to Examples. In addition, each measurement value in an Example was calculated|required by the following method.

〔Glass-transition temperature〕

Differential scanning calorimeter (PERK N-ELMER DSC)
IE type), the measurement was carried out using the following method.

After replacing the sample with nitrogen at room temperature for 5 minutes, it was heated for 1 hour under a nitrogen stream.
The temperature was raised to 280°C at a rate of 16°C per minute, and then the temperature was kept constant for 5 minutes. Then, the glass transition temperature is expressed as the glass transition temperature measured at the time of re-heating in a measurement method in which the temperature is left to cool to room temperature, the temperature is raised again at the same heating rate, and the temperature is lowered to room temperature at a cooling rate of 16°C per minute at the 280°C point.

[Melt viscosity]

It is expressed as a value measured at the melt spinning temperature using a melt indexer (manufactured by TAKARAT Corporation).

[Thermal adhesive function]

Single yarn 2 denier, cut length 5. Own PET staple 5g and single yarn 2 denier obtained by the manufacturing method of the present invention,
Long 50 pane staples mixed with hand card, 30
It was packed in a φ×15N container and heat treated at 100°C for 5 minutes under a load of 100g.

Yarns whose 60φX15wn shape increases by less than 5% of the capacity when the load is removed after cooling are considered to have good thermal bonding function, and yarns whose capacity increases by less than 5 to 20 times are considered good by 20% or more. The increased threads are ranked as having poor thermal bonding function.

Example 1 (1) Dimethyl isophthalate and dimethyl isophthalate in the molar ratio shown in Table 1, ethylene glycol in twice the molar amount of the total acid component, and 1 mol of calcium acetate per total acid component.
A transesterification reaction was carried out by charging 0.08% by weight of hydrated salt. Then, antimony dioxide o, as
M amount%, 0.03% by weight of riftyl phosphate, and 0.5% by weight of titanium oxide were added, and the mixture was polymerized at 290° C. for a predetermined period of time.

The polymer was then introduced into an aqueous layer, cooled, and taken out from the aqueous layer.
t/-i= After reducing the moisture adhering to the sprayed polymer surface, 5φ×3 dark thick U≦polymer particle size≦12
It was made into polymer particles that are metsuyu.

(2) Charge the particulate polymer into a rotary vacuum dryer at room temperature under nitrogen gas flow. 0.5 at the same time as rotation starts
The pressure was reduced to n+mHg, the temperature was raised linearly from room temperature to the drying temperature shown in Table 1 over 2 hours, and then the temperature was kept constant and dried for 20 hours.

(3) The dried polymer particles were charged into a melt hopper under a nitrogen stream of a pret 7-year melter type spinning machine.

Next, 36 holes of 0.23φ, discharge amount 28 g
/-i, spinning at a spinning temperature of 270°C, 1400 m/s
The fibers were wound up at a take-up speed of 1.5 in. to obtain a heat-adhesive fiber with a single yarn denier of 5 deniers.

The dried polymer particles of the present invention (experiments/161-9) were 9
The content of 7% by weight or more was in the range of 16 meshes/unit to 8 meshes, which was good, and the fiber forming property was also very good, and the fiber thermal adhesion function was also sufficiently exhibited.

Those to which other acid components were added are also listed in Table 1 as Experimental rots 7 to 9.

When the melt viscosity after drying was outside the range of the present invention [η] of 400 poise, fiber formation could not be achieved. Also,
When the drying temperature exceeded Tg+15° C., the polymer particles became agglomerated and could not be used for spinning.

Example 2 Polymer particles obtained under the same conditions as in Example 1 Experiment A5 were dried for 20 hours in a rotary dryer under an air stream at 74°C. Polymer particles having a polymer melt viscosity of 1500 poise after drying were charged into a sheath melt hopper under a nitrogen stream of a Pressure Merck one-type core-sheath composite spinning machine, and the core melt hopper, which was also under a nitrogen stream, was charged. A hopper was charged with polyethylene/terephthalate: PET (intrinsic viscosity 0.63 g/dA measured at 25° C. in orthochlorophenol solvent).

Next, the sheath melting temperature is 270°C, and the core melting temperature is 29.
0℃, joint temperature 290℃, discharge amount 15g/each.
Sia core-sheath composite ratio 50:50. A core-sheath composite yarn of 18 denier single yarn was obtained.

Subsequently, the yarn was stretched 5.6 times in a 95°C liquid bath, and the yarn strength was
, qy, /d, a good core-sheath composite yarn with an elongation of 54% was obtained. The fiber formation and thermal bonding functions of this composite yarn were good.

Patent applicant: Toshi Co., Ltd. Procedures Amendment: January 5th, 5th, 6th, 1947 Kazu Wakasugi, Director General of the Patent Office Failure 1, Indication of the incident Patent Application No. 211220 of 1982 2, Name of the invention Polyester fiber 3. The person making the amendment voluntarily 5. The number of inventions increased by the amendment None 6. "Detailed description of the invention" column (1) of the specification subject to the amendment, page 10, line 8 of the specification Correct "cooling" to "quick cooling".

(2) Same page 10, line 4 Correct "Type IB" to "Type r+B".

(3) Same page 11 bottom line Correct "5φ x 3 lies" to "14 meshes".

that's all

Claims (1)

[Scope of Claims] A low-crystalline polyester polymer containing at least one aromatic or aliphatic dicarboxylic acid or oxycarboxylic acid component other than child phthalic acid in a polyester whose main component is polyethylene terephthalate or polybutylene terephthalate. Coalescence is carried out by determining the relationship between the drying temperature (TD 2°C) and the glass transition temperature (Tg:°C) of the polymer when the total polymer particles on a 90-weight plate are larger than 16 meshes and smaller than 12 meshes. Following formula 3 formula % After drying at a temperature that satisfies all, 500 poise or more 6
Method for producing polyester fiber 1 characterized by melt spinning at a melt viscosity [η] of 200 poise or less