JPH0461110B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to high strength polyester fibers.
For more details, please refer to resorcin, formalin,
The present invention relates to high-strength polyester fibers for rubber reinforcement that generate less smoke when treated with a latex liquid (referred to as RFL liquid) and that provide high strength treated cords. (Prior art) In recent years, the need to improve tire quality and productivity has become more important than ever, and polyester fibers are increasingly required to have higher strength and improved heat resistance. . For this reason, polyester fibers are stretched at higher temperatures and higher ratios in order to obtain high strength, so there is a need for processing agents that have excellent oil film strength at high temperatures and high contact pressures and also have excellent smoke generation properties. . Furthermore, after twisting, the cord is treated with RFL liquid, dried, and heat treated to obtain a treated cord, which is required to have high strength and generate little smoke during heat treatment. In order to satisfy these demands, conventionally,
Smoothing agents containing sulfur elements, such as diester of thiodipropionic acid and monohydric alcohol (JP-A-Show)
52-103590) and mono- and diesters of EO adducts of thiodipropionic acid and monohydric alcohol (Japanese Patent Application Laid-open No. 148216/1982). In addition, in order to reduce the friction between fibers especially at high contact pressures, a high molecular weight activator such as an alkylene oxide adduct of an ester of a polyhydric alcohol and a hydroxymonocarboxylic acid and maleic acid are used as essential components. Esters with carboxylic acid components (Unexamined Japanese Patent Publication No. 1983
-223368) have also been proposed. However, the strength of the filament is 8.5g/
In order to obtain a product exceeding d, it is necessary to significantly increase the yarn tension during spinning and drawing, and to raise the heating temperature significantly.The requirements for oil film strength and smoke generation properties have also become more stringent, and the conventional smoothness has become more difficult. A combination of only the active agent and the high molecular weight active agent will not produce the desired effect. That is, even if the strength of the filament is increased, the strength of the final treated cord does not increase, and smoke generation also increases. As a means to solve this problem, increasing the proportion of the smoothing agent, using a polymer activator,
Alternatively, methods have been proposed such as lubricating with non-water-containing oil (Japanese Patent Application Laid-open No. 60-9919), but these methods all have re-emulsifying properties (solubility when the oil on the fiber enters the RFL liquid). There was a problem that it was inferior to If this re-emulsifying property is reduced, the viscosity of the RFL liquid will change, the emulsification balance of the RFL liquid will be disrupted, and the latex portion will separate, which is undesirable. In order to improve the re-emulsifying properties of such processing agents, it is necessary to reduce the proportion of the leveling agent,
A decrease in molecular weight can be considered, but this is not preferable because it tends to increase smoke generation and decrease smoothness. (Object of the invention) The object of the invention is to provide a filament with a strength of 8.5.
The object of the present invention is to provide a high-strength polyester fiber that exhibits an increase in treated cord strength as the filament strength increases in terms of g/d and also has low smoke-emitting properties. (Structure of the Invention) As a result of intensive studies to achieve the above object, the present inventors have found that a smoothing agent based on a sulfur-containing ester (hereinafter sometimes referred to as an S-containing ester) with a specific molecular weight, and a smoothing agent based on a non-sulfur-containing ester. When used in combination with polymeric activators and nonionic activators, smoke generation and
The inventors discovered that it is possible to stably obtain polyester fibers that simultaneously satisfy RFL permeability, and arrived at the present invention. That is, the present invention includes (a) 62% by weight or more of a smoothing agent (component A) mainly composed of a sulfur-containing ester compound with a molecular weight of 600 or more, and (b) a non-sulfur smoothing agent with a molecular weight of 5000 or more and liquid at 15°C. Contains an ester polymer activator (component B) of 8% by weight or more, (c) a nonionic activator with a molecular weight of 800 or more (component C)
Contains 20% by weight or less, and A+B is 90% by weight
It is a polyester fiber to which the following processing agent has been applied, and the polyester fiber is a high-strength polyester fiber characterized by simultaneously satisfying the following () to (). () Filament strength≧8.5g/d () Smoke generation≦1500 () RFL permeability≦5cm The present invention targets polyester fibers whose filament strength is 8.5g/d or more after spinning. do. If the fiber is less than 8.5 g/d, there will be no difference in the strength of the treated cord, whether it is treated with the treatment agent used in the present invention or a conventionally known treatment agent. is rarely expressed. However, more than 8.5 g/d, especially 9.0
g/d or more, it has been found that the strength of the treated cord obtained from the polyester fiber of the present invention increases as described below. The smoothing agent (property A component) constituting the treatment agent applied in the present invention must have a sulfur-containing ester smoothing agent with a molecular weight of 600 or more as the main component (here, the main component refers to the component A). 50% or more by weight). If the molecular weight of the sulfur-containing ester is less than 600 or the proportion of the sulfur-containing ester in component A is less than 50%, the smoothness of the treatment agent will be poor, resulting in yarn breakage during drawing heat treatment, a decrease in the strength of the treated cord, and even worse. Unfavorable because it generates a lot of smoke during manufacturing. Also,
Component A needs to be at least 62% by weight based on the processing agent. If it is less than 62% by weight, it is also not preferred because the smoothness of the processing agent decreases. Here, as a sulfur-containing ester smoothing agent,
Compounds having a sulfur atom in the molecule include, for example, diesters of thiodipropionic acid and higher alcohols. Higher alcohols include saturated or unsaturated alcohols with straight or side chains of natural or synthetic alcohols, and alcohols containing aromatic nuclei;
Among these, particularly preferred are linear unsaturated aliphatic alcohols. Specifically, dioleylthiodipropionate is preferably used. Non-sulfur-containing ester polymer activator (component B)
Examples include alkylene oxide-modified polyester obtained by polymerizing an alkylene oxide adduct of an ester consisting of a polyhydric alcohol and a hydroxycarboxylic acid and maleic acid, a polyester obtained from polyalkylene glycols and a dibasic acid, etc. There is no need to particularly limit the terminal end. That is, any high molecular weight polyester having polyalkylene glycols in either the main chain or the side chain may be used. Specifically, for example, polyesters made from castor oil and maleic acid or maleic anhydride added with ethylene oxide, polyesters made from sorbitol, ricinoleic acid, and maleic acid or maleic anhydride, and polytetramethylene glycol added with alkylene oxide and maleic acid. Or polyester from maleic anhydride, etc. can be mentioned. Such B component has a molecular weight of 5000 or more and 15
It must be liquid at ℃, and the usage ratio is 8% by weight.
It is necessary to do more than that. If the molecular weight is less than 5000, the smoothness of the treatment agent will be poor, and in solid form, the variation in smoothness will increase and at the same time the adhesion to rubber will decrease, and if the usage ratio is less than 8% by weight, the smoothness will be poor. At the same time, the re-emulsifying property of the processing agent deteriorates, which is not preferable. In addition, in this treatment agent, the usage ratio of A + B is 90
It is necessary to keep it below % by weight. If it exceeds 90% by weight, the re-emulsifying properties of the processing agent will deteriorate, which is not preferable. As the nonionic activator (component C), derivatives of polyhydric alcohols that have an emulsifying effect and are excellent in smoke generation and smoothness, such as castor oil, hydrogenated castor oil, trimethylolpropane, glycerin, and other polyhydric alcohols in which ethylene oxide is added are used. Examples include those with 5 to 40 moles added, and esters of these ethylene oxide-added polyhydric alcohols and aliphatic carboxylic acids. Specific examples include polyoxyethylene hydrogenated castor oil ether and polyoxyethylene sorbitan triolate. The molecular weight of such nonionic activator (component C) is 800 or more,
The proportion used must be 20% by weight or less.
If the molecular weight is less than 800, the processing agent will generate more smoke, while if the proportion exceeds 20% by weight, smoothness will be impaired, which is not preferable. In addition to the above-mentioned components A, B, and C, a small amount of an antistatic agent, an emulsifying agent, an oxidation stabilizer, etc. may be added to the processing agent of the present invention without any problem. For example, as an antistatic agent, oleyl phosphate and its salts (Na,
K, amine, etc.), polyoxyethylene oleyl phosphate and its salts (Na, K, amine, etc.),
Examples include dioctyl sulfosuccinate Na salt, alkanesulfonates and their salts (Na, K, amines, etc.). In order to apply such a treatment agent to polyester fibers, conventionally known methods such as roller oiling or nozzle oiling can be used in the spinning process in the form of a water-free type or an emulsion emulsified with water. /d or more requires high-speed spinning and high-temperature heat treatment, so it is preferable to use a nozzle oiling method with a non-hydrous treatment agent. The amount of the treatment agent deposited on the fiber is preferably 0.1 to 2.0% by weight, preferably 0.2 to 1.0% by weight. The polyester fiber thus obtained has a smoke production value of 1500 or less and an RFL measured at 230°C as described below.
It also has the effect of maintaining permeability below 5 cm. If the smoke-emitting property exceeds 1500, a lot of smoke will be emitted when it is immersed in RFL liquid to form a treated code. Furthermore, when the RFL permeability exceeds 5 cm, the strength of the treated cord decreases, presumably because the RFL liquid penetrates into the inside of the treated cord and restricts the movement of each filament that makes up the cord. The polyester fiber used in the present invention is obtained by directly spinning and drawing polyethylene terephthalate or a polyester mainly composed of polyethylene terephthalate after melting it in an extruder according to a conventional method. (Function) When the filament strength is 8.5g/d or more,
Although it is not clear why the effects of the present invention appear,
At present, it can be considered as follows. In order to increase the filament strength to 8.5 g/d or more, it is necessary to have extremely high crystallinity and orientation of the polyester fibers, which changes the fiber surface condition (changes in friction between fibers, etc.) and increases the elongation. will also be on the lower side. As a result, the tensile behavior of the cord changes, and it becomes necessary to further improve the smoothness between the fibers in order to increase the strength of the treated cord. In order to achieve this requirement, the processing agent used in the present invention has the above-mentioned structure, and has high heat resistance and high surface strength (even if the contact pressure between the filaments is high, the processing agent film is firmly adhered to the filament surface). Therefore, it can withstand the strict spinning conditions (high-temperature heat treatment, high spinning tension, high drawing tension) adopted to obtain polyester fibers with a filament strength of 8.5 g/d or more, and has sufficient treatment agent remaining on the filament surface, allowing the filament to Improves stretchability by reducing friction between Furthermore, even when the polyester fibers obtained according to the present invention are twisted to form a cord, the treating agent has a high surface strength, so even if a large pressure is exerted between the filaments during twisting, the treating agent remains sufficiently between the filaments. Therefore, due to the compatibility between the RFL liquid and the treatment agent of the present invention, the permeability of RFL is 5 cm or less, and the RFL liquid does not penetrate much into the treated cord, allowing each filament that makes up the cord to move freely. Become. As a result, the processing code becomes more powerful. Furthermore, since the processing agent used in the present invention has a large molecular weight and high heat resistance, it can withstand high-temperature heat treatment during production of the processing cord, and its smoke-emitting properties are also reduced. Since the above effects are simultaneously expressed, it is considered that the intended purpose can be achieved only when the processing agent of the present invention is used. (Effects of the Invention) Since the polyester fiber of the present invention has a low smoke-emitting property, the working environment when making it into a treated cord is improved. In addition, since the RFL permeability is low, a highly powerful processing cord can be obtained, and its industrial effects are extremely large. (Examples) Hereinafter, the present invention will be further explained with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation method was as follows. Sample: When polyethylene terephthalate with an intrinsic viscosity of around 0.95 is melted and produced by the direct spinning/drawing method, a treatment agent mentioned above is applied in the form of a non-water-containing oil and a yarn (1500De /250fil). A two-strand cord (raw cord) with a twist count of 40 x 40 T/10 cm was created using a ring twisting machine for tire cord. Next, this raw cord was immersed in an RFL solution using a single cord dipping machine, dried at 130°C for 2 minutes, and then heat-treated at 240°C for 1 minute to obtain a treated cord. Here, the RFL liquid has the composition shown in Table 1.
A PEXUL adhesive that had been aged in a conventional manner was used.

[Table] The amount of RFL liquid adhered was 2.5% by weight. Each characteristic was measured according to the following method. Stretchability: Stretchability was defined as the number of fluffs with a length of 1 mm or more on the surface of a 10 kg bobbin (0.45 m ² ) that was wound at 5000 m/min. Smoke generation: Place a load of 250 g on the yarn so that it is almost touching it on a vertically long (width 5 cm, length 50 cm) hot plate heater, and cover it. Then, make a slit (width 5mm) between the bottom of the heater and the cover.
A small hole (diameter 5cm, depth 1cm) installed at the top of the heater measures the amount of smoke in the air that rises through the heater.
mm) at a rate of 10/min.
3), and the cumulative value for 3 minutes was taken as the smoke density. The heater temperature was 230°C. Cord strength: Test length with Intesco tensile tester
The processing cord was determined to be strong at 25cm. Re-emulsifying property: Mix RFL liquid and processing agent (each 20% aqueous solution) at a ratio of 6:1, place on a 20cm x 20cm square glass plate in an amount such that the solid content is 0.4mm thick, and place in a fume hood at room temperature. While air drying, the dry state of the surface layer was visually observed for 2 days. ○…Forms a uniform film over the entire surface △…Forms a hard film in some areas (20% of the total surface area)
(within) ×…forms a partially hard film (20% of total surface area)
(above) RFL permeability: A 30 cm yarn with a tension of 200 g was held vertically, the lower end was immersed in a 20% aqueous RFL solution, and after 5 minutes the height of the RFL solution rose above the liquid level. The test was carried out in an atmosphere of 20°C and RH65%. Examples 1 to 7 and Comparative Examples 1 to 8 The spinning and drawing conditions were set so that the filament strength was 9.0 g/d, and the treatment agents shown in Table 2 were used. The results are shown in Table 3.

【table】

[Table] As is clear from the results in Table 3, according to the present invention (Examples 1 to 7), the strength of the processing code is high;
High strength polyester fibers with low smoke generation can be obtained. However, the molecular weight of component A is less than 600, the proportion of component A is less than 62% by weight, the molecular weight of component B is less than 5000, the proportion of component B is less than 8% by weight, A+B exceeds 90% by weight, and the molecular weight of component C is is less than 800, or when the proportion of component C exceeds 20% by weight, the stretchability, smoke-emitting property, cord strength, re-emulsifying property, and RFL permeability are unsatisfactory.

[Table] Examples 8 and 9 and Comparative Examples 8 to 11 The spinning and drawing conditions were changed so that the filament strength was 8.0 g/d to 9.5 g/d. In addition, the treatment agent used in Example 1 or Comparative Example 1 was used. The results are shown in Table 4. Note that the results of Example 1 and Comparative Example 1 are also shown. As is clear from these results, according to the present invention (Examples 1, 8, and 9), it is possible to obtain high-strength polyester fibers with high strength treated cords, low smoke generation, and low RFL permeability. However, in Comparative Examples 1 and 9 to 11, which satisfy the other conditions but have a small molecular weight of component A and do not satisfy the conditions of the present invention, even if the filament strength increases,
The power of the processing code is hardly increased and the results are not satisfactory. Further, even if the treatment agent satisfies the conditions of the present invention, if the filament strength is low, this is not preferable because the strength of the treated cord is low.

【table】

Claims (1)

[Scope of Claims] 1 (a) 62% by weight or more of a smoothing agent (component A) mainly composed of a sulfur-containing ester compound with a molecular weight of 600 or more, (b) a smoothing agent with a molecular weight of 5000 or more and liquid at 15°C. 8% by weight or more of a non-sulfur-containing ester polymer activator (component B), (c) a nonionic activator with a molecular weight of 800 or more (component C)
Contains 20% by weight or less, and A+B is 90% by weight
A high-strength polyester fiber to which the following processing agent has been applied, characterized in that the polyester fiber satisfies the following conditions () to () at the same time. () Filament strength≧8.5g/d () Smoke generation≦1500 () RFL permeability≦5cm