JPH07300726A - Production of polyester fiber - Google Patents

Abstract

PURPOSE:To produce a polyester fiber resistive to, e.g. fray of single yarns caused by cutting in the direction of the fiber axis when used in a composite material with rubber by melt spinning PET having a relatively high polymerization degree of at a high speed, applying a specified spinning oil thereto, heat stretching it and subsequently applying a specified finishing oil thereto immediately before winding it. CONSTITUTION:Polyethylene terephthalate having 0.8 to 1.1 intrinsic viscosity or a polyester composed mainly of it is subjected to melt spinning and drawn at >=3000m/min in the form of unstretched yarn oriented and crystallized in a low oriented state. The spinning oil contains >=80wt.% composition composed of (A) 5 to 40wt.% ester between an aliphatic alcohol and an aliphatic carboxylic acid and (B) 95 to 60wt.% ethylene oxide and/or propylene oxide addition compound of an aliphatic alcohol. The unstretched yarn is subjected to heat stretching and wound. A finishing oil agent is applied immediately before winding and the finishing oil contains >=40wt.% ethylene oxide and/or propylene oxide addition compound of an aliphatic acid amide compound. Thus, the objective fiber having a satisfactory strength can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyester fibers suitable for industrial materials, especially for belts.

[0002]

2. Description of the Related Art Polyester fibers represented by polyethylene terephthalate fibers have excellent physical and chemical properties, are industrially mass-produced, and are extremely useful fibers widely used in various fields. With the increasing demand for higher performance, fibers having good dimensional stability against heat have been demanded.

As a method for increasing the dimensional stability of polyester fibers against heat, a method is known in which an unstretched yarn having a high degree of molecular orientation is taken up and subjected to heat stretching by increasing the spinning speed. For example, in Japanese Examined Patent Publication No. 3-21647, a melt spun yarn is drawn at a speed of 3000 m / min or more, and an oriented and crystallized undrawn yarn is drawn at a drawing start temperature of 125 ° C. or more.
A method of drawing at a draw ratio of 1.5 to 2.0 times has been proposed, but the breaking elongation of the drawn yarn is extremely low at about 7 to 8%, and there is a problem in operation in this case as well. When the drawing is performed at a high speed as in the spin draw method which is performed as described above, the operation is extremely difficult.

As a method for producing a fiber satisfying both thermal dimensional stability and strength on an industrial scale with good production, a melt spun yarn is drawn at a speed of 3000 m / min or more, and oriented crystallization is performed in a state where the degree of orientation is low. There is a method (Japanese Patent Application No. 4-359559) for hot drawing the undrawn yarn.

On the other hand, rib V belts, timing belts, etc., which are typified by transmission belts, are formed in a tubular shape in advance from the vulcanized polyester fiber reinforced rubber composite into a sliced shape in order to simplify the manufacturing process by reducing the cost. It is cut and commercialized. However, a single yarn is frayed from the polyester fiber exposed on the side surface of the belt cut in the fiber axis direction,
May project like fluff. In that case, not only the quality of the product will deteriorate, but if you set it on the pulley and operate it as it is, the frayed part of this single thread is rubbed by the pulley and the frayed single thread scatters, and this fraying causes the belt to break. It may reduce durability.

As a method for solving this problem, after twisting the polyester fiber into a cord, the cord is impregnated with an epoxy adhesive and / or an isocyanate adhesive and heat-treated to form a polyester fiber single yarn. A method for adhering the gaps (Japanese Patent Laid-Open Nos. 60-110978 and 60-110979)
No. 60-110980). However, in the case where the conventional spinning oil agent is added, the compatibility between the oil agent and the adhesive is poor, and the oil agent and the adhesive are separated from each other, or the adhesive does not sufficiently penetrate into the inside of the fiber, so that a sufficient effect is obtained. Was not obtained. On the other hand, when a spinning oil agent that does not have such a problem is used, there is a problem that single yarn breakage occurs frequently in the manufacturing process of the polyester fiber because the yarns on the take-up roller and the drawing roller do not have a bundling property.

[0007]

The present invention has high strength,
It has excellent dimensional stability against heat, and when it is treated as a cord with an epoxy adhesive and / or an isocyanate adhesive and the ordinary RFL treatment is performed, the adhesiveness with rubber becomes good, and using this cord When the polyester fiber reinforced rubber composite is cut in the axial direction of the fiber, the polyester fiber having the property of not fraying the single filament of the polyester fiber exposed on the cut surface and protruding in a fluff shape from the cut surface is manufactured with good operability. It is intended to provide a method for producing a polyester fiber that can be used.

[0008]

[Means for Solving the Problems] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that the melt-spun yarn is 3000
At a speed of m / min or more, in the method for producing a polyester fiber, which is taken as an undrawn yarn that is oriented and crystallized in a state where the degree of orientation is low and is hot-drawn, by adding a spinning oil agent and a finishing oil agent having a specific composition, The inventors have found that the object is achieved and have reached the present invention.

That is, the gist of the present invention is as follows. Polyethylene terephthalate having an intrinsic viscosity of 0.8 to 1.1 or polyester composed mainly of this is melt-spun and
At the speed of 00 m / min or more, it is taken as an oriented and crystallized unstretched yarn in a low degree of orientation, and when hot-stretched to produce a polyester fiber, the following spinning oil agent is added, and after hot stretching, immediately before winding. A method for producing a polyester fiber, which comprises adding the following finishing oil agent to Spinning oil agent; an oil agent containing 80% by weight or more of a composition comprising the following two components (A) an ester of an aliphatic alcohol and an aliphatic carboxylic acid 5 to 40% by weight (B) ethylene oxide and / or a protic acid of an aliphatic alcohol Pyrene oxide adduct 95-60% by weight Finishing oil agent; Oil agent containing 40% by weight or more of ethylene oxide and / or propylene oxide adduct of fatty acid amide compound

The present invention will be described in detail below. In the present invention, polyethylene terephthalate having an intrinsic viscosity (measured at a temperature of 20 ° C. with an equal weight mixture of phenol and tetrachloroethane as a solvent) in the range of 0.8 to 1.1 or a polyester mainly composed thereof is melt-spun, and 3000
The undrawn yarn is drawn at a speed of m / min or more. If the intrinsic viscosity is lower than this range, the strength properties of the fiber will be inferior,
On the other hand, if it is higher than this range, the spinning stress is high and the spinnability is deteriorated, which is not preferable. Further, if the spinning speed is less than 3000 m / min, fibers having good dimensional stability cannot be obtained.

In the present invention, it is necessary to obtain an undrawn yarn that is oriented and crystallized in a state where the degree of orientation is low. To this end, melt spinning at a high speed and setting an extreme temperature gradient on the spinning line may control the crystallization and orientation of the undrawn yarn. For example, the spinning temperature is set to 290 to 310 ° C, and the atmospheric temperature 10 cm below the spinneret is controlled to 300 to 350 ° C by disposing a heating cylinder or the like. If the spinning temperature and this atmospheric temperature are lower than this range, the initial stress is high and it is difficult to take off at a high speed of 3000 m / min or more. If the spinning temperature and this atmospheric temperature are higher than this range, the subsequent cooling becomes incomplete. The occurrence of oriented crystallization is delayed, resulting in a highly oriented undrawn yarn. Furthermore, in order to keep the ambient temperature below 60 ° C 30 to 70 cm below the spinneret where oriented crystallization is expected to occur, cool air at 10 to 25 ° C should be applied at a wind speed of 60 m / min or more.
Cool by spraying over a length of 20 cm.

Thus, the density of the undrawn yarn is 1.360.
g / cm ³ or more, the spinning conditions are set so that the birefringence is 0.07 to 0.09, and the obtained undrawn yarn is not wound up,
When heat-stretched at a draw ratio of 1.5 or more, a polyester fiber having high strength and excellent dimensional stability against heat can be obtained.

In the present invention, the fiber means a multifilament, and the single yarn fineness, the total fineness, the number of filaments, the cross-sectional shape, the presence or absence of additives, and the polymer properties (terminal carboxyl group concentration etc.) are not limited. Not a thing.

In the present invention, when a polyester fiber is produced under the above-mentioned conditions, first, as a spinning oil agent, a composition consisting of the above two components (A) and (B) is used.
An oil agent containing at least wt% is applied. In the oil agent component, EO means ethylene oxide, PO means propylene oxide, POE means polyoxyethylenation, and the value in parentheses means the number of moles added.

The component (A) is an ester of an aliphatic alcohol and an aliphatic carboxylic acid, and has the function of enhancing the yarn bundle converging property in the yarn making process. As the aliphatic alcohol and the aliphatic carboxylic acid, those having 6 to 22 carbon atoms are preferable. (A sulfur atom or phosphorus atom may be introduced to improve heat resistance.) Specific examples of the component (A) include dioleyl adipate,
Examples include oleyl oleate, lauryl oleate, isostearyl oleate, isotridecyl palmitate, diglycidol dioleate, dioleyl thiodipropionate. The compounding amount of the component (A) is 5 to 40% by weight, preferably 10 to 35% by weight. If this amount is less than 5% by weight, the spinnability is deteriorated, and if it is more than 40% by weight, the anti-raveling effect is lowered.

The component (B) is an EO and / or PO adduct of an aliphatic alcohol, and has a function of penetrating the adhesive to a deep portion when the cord is treated with the adhesive. The aliphatic alcohol preferably has 4 to 22 carbon atoms, and the number of added moles of EO and / or PO is 4
~ 20 is preferred. Specific examples of the component (B) include POE (6)
Stearyl ether, POE (6) oleyl ether, POE (1
0) Oleyl ether, POE (10) Cetyl ether, POE
(8) Lauryl ether, PO (5) / EO (5) monobutyl ether, POE (20) glycerin ether and the like can be mentioned.
The blending amount of the component (B) is 95 to 60% by weight, preferably 90 to
It is 65% by weight. If it is out of this range, the effect of preventing fraying is reduced.

The spinning oil in the present invention is such that the total of the two components (A) and (B) is 100% by weight, and the composition is used in an amount of 80% by weight or more and 20% by weight or less.
It is used by blending an emulsifier, an antistatic agent, a heat resistance agent and the like. The spinning oil is usually used in the form of a straight oil (non-water oil) diluted with a low-viscosity mineral oil or the like, but may be used as an aqueous emulsion oil. In addition, EO of a fatty acid amide compound which is an essential component of a finishing oil agent in a spinning oil agent
It is desirable not to add this to the spinning oil agent, because the addition of the PO additive and / or the PO additive tends to cause roller fouling.

Next, after applying the spinning oil as described above and hot drawing, the finishing oil is applied immediately before winding. The finishing oil agent is EO and / or PO of a fatty acid amide compound.
It contains a component consisting of an additive, and this component has a good affinity with the adhesive when treated as a cord with an adhesive and allows the adhesive to penetrate deep and cure the adhesive. It acts. The fatty acid amide compound preferably has 4 to 22 carbon atoms, and the added mole number of EO and / or PO is preferably 4 to 20. Specific examples of EO and / or PO adducts of fatty acid amide compounds include POE (5) oleic acid amide, POE (10) oleic acid amide, POE (15) oleic acid amide, POE (8) lauric acid amide, POE (10) stearic acid amide, POE (10) lauric acid ethanolamide, POE (10) oleic acid ethanolamide, POE (10) oleic acid diethanolamide and the like. The content of the EO and / or PO adduct of the fatty acid amide compound needs to be 40% by weight or more, and preferably 55 to 95% by weight. If it is out of this range, the effect of preventing fraying is reduced. Other components to be added to the finishing oil agent include components (A) and (B) of the spinning oil agent and natural oils such as coconut oil, rapeseed oil and sperm oil, but the same ingredients as the spinning oil agent should be added. Is desirable. Further, if necessary, an emulsifier, an antistatic agent, a heat-resistant agent, etc. are added.

The finish oil agent is usually used in the form of an aqueous emulsion oil agent, but it may be used as a straight oil agent (non-water oil agent) diluted with a low-viscosity mineral oil or the like.

The spinning oil agent and the finishing oil agent are applied to the yarn by a usual roller type oil supply method or a nozzle type oil supply method. The amount of spinning oil applied is 0.1 to 1.0% by weight, preferably 0.2 to
0.5% by weight is suitable, and the amount of finishing oil applied is 0.2-
1.0% by weight, preferably 0.3-0.8% by weight is suitable.

[0021]

EFFECTS OF THE INVENTION According to the present invention, as a spinning oil agent and a finishing oil agent, when the adhesive agent is treated as a cord with a component and a cord which enhances the sizing property of the yarn in the spinning process, the adhesive agent is allowed to penetrate deeply or to be bonded. Since it gives a component to cure the agent,
It has good spinnability and good adhesion to rubber just by performing ordinary RFL treatment, and when it was cut in the fiber axis direction as a polyester fiber reinforced rubber composite using this cord, it was exposed on the cut surface. It is possible to prevent fraying of single filaments of polyester fiber and fluff-like protrusion from the cut surface. When the finish oil agent is applied in front of the heat treatment roller, roller stain may occur and the operability may be deteriorated. However, by applying the finish oil agent immediately after winding after hot drawing, this problem is solved. .

[0022]

EXAMPLES Next, the present invention will be described in detail with reference to examples. In addition, "part" means a weight part and the measuring method is as follows. (a) Using a cord strength / elongation autograph, measure according to JIS-L-1017. (b) Dry heat shrinkage According to JIS L-1017, the sample is heat-treated at 150 ° C for 30 minutes without tension and measured. (c) Spinnability The number of windings of the single yarn around the roller due to breakage of the single yarn by the take-up roller and the stretching roller in the yarn making process is evaluated in the following three stages. ○: 0 to 3 times / 1 day △: 4 to 10 times / 1 day ×: 11 times or more / 1 day (d) Anti-raveling The treated cords are arranged in parallel between two 3 mm thick rubber sheets. Sandwich and vulcanize at 150 ° C for 30 minutes under a pressure of 50 kg / cm ² to obtain a rubber sheet. This sheet is cut with a cutter knife in the fiber axis direction of the cords arranged in rubber,
Make sure the end of the cord is exposed on the cut surface. Then, while observing the protruding state of the single yarn of the polyester fiber from the end face with the naked eye, rub the end face with sandpaper (# AA-120) 10 times and observe the frayed state of the single yarn. Evaluate with. ◯: No protrusion of single yarn or fraying of single yarn is observed. Δ: The single yarn does not jump out, but the single yarn is unraveled. X: Single yarn jumping out and single yarn fraying are recognized. (e) Adhesiveness Using a rubber composition having the composition shown in Table 1, JIS-L-1017 A
Measure according to the method.

[0023]

[Table 1]

Examples 1 to 3 and Comparative Examples 1 to 4 [Preparation of Spinning Oil Agents (a) to (e)] 50 parts of low-viscosity mineral oil having RW of 30 seconds was heated to 40 ° C. 50 parts of the oil agent composition blended in (4) was heated to 50 ° C., stirred slowly while being added, and then cooled to room temperature.

[0025]

[Table 2]

[Preparation of Finishing Oils a to d] 77 parts of water at 40 ° C.
Then, 23 parts of the oil agent composition containing the respective components in the proportions (parts) shown in Table 3 and heated to 40 ° C. was slowly added and stirred, and then cooled to room temperature.

[0027]

[Table 3]

[Preparation of Isocyanate Adhesive] Tris (p-isocyanatophenyl) thiophosphate having a solid content of 27% was added to 75 parts of toluene;
25 parts of "E" (trade name of Sumitomo Bayer Urethane Co., Ltd.) was slowly added and dissolved by stirring.

[Preparation of RFL Solution] To 125 parts of water, 19 parts of 10% aqueous sodium hydroxide solution was added, then 17 parts of resorcinol was added and dissolved by stirring, and then 30 parts of 37% aqueous formaldehyde solution was added and stirred. The mixture was reacted at 25 ° C for 30 minutes. The resulting reaction liquid was VP latex having a solid content of 41%; "Pilatex J-1904" (trade name of Sumitomo Dow Co., Ltd.) and SBR latex having a solid content of 40%; "JSR-2108" (Japan Synthetic Rubber). Brand name of the company) 190 parts of the mixed solution was added with stirring, 431 parts of water was added with stirring, and the mixture was stirred and mixed for 10 minutes and then aged at 25 ° C. for 24 hours.

[Production of Polyester Fiber] Intrinsic viscosity is 0.
90 polyethylene terephthalate chips were fed to an extruder type melt spinning machine, the spinning temperature was set to 305 ° C, spun from a spinneret having 300 spinning holes with a diameter of 0.5 mm, and the length was set just below the spinneret. After passing through a heating tube of 10 cm and a temperature of 330 ° C, use a cylindrical cooling device with a length of 30 cm to make it 18 ° C
Was blown onto the yarn at a speed of 72 m / min to cool the yarn. Then, the spinning oil agent shown in Table 2 prepared by the above-mentioned method by the roller type oil supply method was applied to the yarn in an amount of 0.4% by weight. Apply a thread with oil to the surface temperature of 70
℃, surface speed 3200m / min, take up with a heat take-up roller, take-up roller and surface temperature 140 ℃, surface speed 4800m
/ Min to 1.5 times with the first stretching roller, then the first stretching roller and the surface temperature 200 ℃, surface speed 6000m
After stretching at a draw ratio of 1.25 times between the second stretching roller and the second stretching roller, the surface temperature is 200 ° C. and the surface speed is 5800 m.
After the relaxation heat treatment of 0.97 times was performed between the heat treatment roller and the heat treatment roller, the nozzle oiling method was used to prepare the above-mentioned method.
The finish oil shown in (4) was applied to the yarn in an amount of 0.4% by weight and wound up to obtain 1000d / 300f polyester fiber.

[Treatment of Cord] While twisting two obtained polyester fibers, a twist of 115 times / m is applied to form a twisted cord, and then three twisted cords are twisted and reversely twisted. The cord is twisted in the direction of 115 times / m and twisted into a cord, and the cord is dipped in the isocyanate adhesive solution prepared by the above method (solid content: 2.5 to 3.5% by weight).
After drying with hot air at ℃, it was heat-treated at 240 ℃ for 100 seconds. Then, after soaking in the RFL bath prepared by the above method (amount of solid content 4.5 to 5.5% by weight) and drying at 120 ° C. for 60 seconds,
Heat treatment was performed at 240 ° C for 100 seconds.

Table 4 shows the strength / elongation, dry heat shrinkage, resistance to fraying, adhesiveness, and spinnability of the raw yarn manufacturing process of the treated cord thus obtained.

[0033]

[Table 4]

As is apparent from Table 4, Example 1 of the present invention
In Nos. 3 to 3, the strength, dimensional stability, yarn formability, fray resistance, and adhesiveness were all good. On the other hand, in Comparative Examples 1 and 4, there is a problem in the fray resistance, and Comparative Example 2
In Nos. 3 and 3, the spinnability was poor.

[0035]

EFFECTS OF THE INVENTION According to the present invention, a high strength, excellent dimensional stability against heat, a cord is treated with an epoxy adhesive and / or an isocyanate adhesive, and a conventional RFL is used.
Adhesion with rubber becomes good just by processing, and
When the polyester fiber reinforced rubber composite is cut in the fiber axis direction by using this cord, a polyester fiber having a characteristic that does not fray or protrude from the cut surface of the single filament of the polyester fiber exposed on the cut surface is obtained. It can be manufactured with good operability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Uchida, et al. 23 Uji Kozakura, Uji City, Kyoto Prefecture Unitika Research Institute, Central Research Laboratory (72) Inventor Katsu Sugawa 23 Uji Kozakura, Uji City, Kyoto Unitika Stock Company Central Research In-house

Claims (1)

[Claims] 1. A polyethylene terephthalate having an intrinsic viscosity of 0.8 to 1.1 or a polyester composed mainly of polyethylene terephthalate is melt-spun and taken at a speed of 3000 m / min or more as an undrawn yarn oriented and crystallized in a state of low orientation. A method for producing a polyester fiber, which comprises applying the following spinning oil agent during hot drawing to produce a polyester fiber, and applying the following finishing oil agent immediately after winding after hot drawing. Spinning oil agent; an oil agent containing 80% by weight or more of a composition comprising the following two components (A) an ester of an aliphatic alcohol and an aliphatic carboxylic acid 5 to 40% by weight (B) ethylene oxide and / or a protic acid of an aliphatic alcohol Pyrene oxide adduct 95-60% by weight Finishing oil agent; Oil agent containing 40% by weight or more of ethylene oxide and / or propylene oxide adduct of fatty acid amide compound