JPS61252332A - Production of polyester code - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

a. Industrial application field The present invention is a polyester cord suitable for industrial use, particularly for tire coating, having a high modulus comparable to that of rayon cord.
The present invention provides a method for producing a polyester cord that has low shrinkage and better fatigue resistance than rayon cord. b. Prior Art Polyester fibers have various excellent properties and are widely used not only for clothing but also for industrial purposes.

[There is. % polyester fiber with high strength and excellent dimensional stability,
It is useful in industrial applications and has been used not only for tires but also for industrial assets, but increasingly higher performance is required in recent years. For example, for tire cords, lower shrinkage is required to improve yield during tire molding, and higher motility is required to improve riding comfort.For large tires, fatigue resistance is improved, and for -10,000 V-belts. Cords are required to be highly moisturized to be maintenance-free, and cords for large, high-load lap belts are required to have high elongation, high toughness, and fatigue resistance. From this point of view, it has an excellent low shrinkage of 1 stage! If polyester cords with high modulus and fatigue resistance can be obtained, polyester fibers will be used in an increasing number of fields due to their cost competitiveness with other materials. T# polyester fiber is inferior to Rayo 7M fiber and vinylon fiber, which have a long history of IM, in terms of strength, elasticity, and shrinkage, and is also significantly inferior in fatigue resistance compared to general-purpose polyamide fiber, which has a long history. It is important to improve this point. If these points are improved, polyester fibers will be positioned more highly as industrial fibers as they are superior in cost/performance to rayon fibers, vinyl fibers, and polyamide fibers. Recently, polyester fibers have been widely used, for example, in tire cord applications, primarily as radial tire carcass materials. For example, as proposed in Japanese Patent Application Laid-open No. 53-58032, fibers made by drawing undrawn yarns that are highly oriented compared to conventional ones are highly motile, have low shrinkage, and are resistant to fatigue when used as tire hoods. It is a product that has been significantly improved compared to the conventional one, and is being used favorably because it improves handling stability, ride comfort, and less unevenness during tire molding (so-called dent bulge) when driving at high speeds. However, its performance is still insufficient in terms of modulus and shrinkage compared to older rayon fibers and vinylon fibers. Further, a cord formed from polyester fibers requires a step of embedding it in rubber and cooling it after vulcanization (so-called post-cure injection). This process requires a large capital investment, and in order to rationalize the cost, it is necessary to omit the cooling process.For this reason, it is necessary to have a cord with low shrinkage comparable to that obtained from rayon fibers or vinylon fibers, and the above-mentioned Improvement measures are also insufficient. Means for Solving the C6 Problem The present invention, Nagisa, has been developed as a result of intensive studies to solve this problem, and has been developed by twisting the crystalline drawn rut fibers, which have an extremely high degree of orientation compared to the conventional method, as they are, and creating a yarn with a specific high tensile strength. Only by heat-treating the cord without first stretching it, a polyester cord with unprecedented low shrinkage and high moteulus based on rayon hoods and better fatigue resistance than rayon hoods can be obtained at a lower cost. They discovered this and arrived at the present invention. Namely, the present invention is made of polynisdel whose main structural unit is ethylene terephthalate), which has an intrinsic viscosity of 0.90 or more, has a birefringence of 0.09 to 0.14, and has a crystal melting point of 270° C. or more. - A certain polyester fiber is made into twisted yarn with a twist coefficient of 1500 to 7100 to make a twisted yarn hood, and after being treated with an adhesive, the temperature is 235 to 260°C and the tension is 1
．． 0 to 2.01) / de with substantial stretching. #This is a method for manufacturing polyester cord. Polyester here means 90 mol S or more, preferably 95 mol S or more of ethylene terephthalate repeating units in the molecular chain.
It is a polyester containing mol% or more. As such polyester, polyethylene terephthalate is preferred, but it may contain other copolymer components in a proportion of less than 10 mol %, preferably less than 5 mol %. Examples of such copolymerization components include inphthalic acid, naphthalene dicarboxylic acid, divic acid, oxybenzoic acid, diethylene glycol, propylene glycoltatrimellitic acid, and pentaerythritol. Furthermore, these polyesters may contain additives such as stabilizers and i-coloring agents. The above polyester is melt-spun by a conventional method at a spinning speed of 3500 m/spinning plate to obtain an intermediately oriented yarn. It is necessary that the polyester yarn thus obtained has an intrinsic viscosity of 90 or more as determined from a 0-chlorophenol solution at 25°C. If the intrinsic viscosity is less than 1.90, a polyester cord with high strength cannot be obtained. An intrinsic viscosity of 0.9 to 1.3 is preferable.
09 to 0.14 and a crystalline melting point of 270°C or higher. Here, the birefringence was measured using a Bereck compensator attached to a polarizing optical microscope, and the crystal melting point was measured using a PerkinElmer DSC-1fJ- at a heating rate of 20
Measurement was carried out at a rate of °C/min, and the endothermic peak value was defined as a single crystal point. The intermediately oriented polyester yarn used in the present invention has a birefringence of 0.09 to 0.14 and a crystal melting point of 270°C.
Only when the above conditions are satisfied will the polyester cord obtained be highly motile and have low shrinkage, and if either of these characteristics is lacking, the goals cannot be achieved. Once the above characteristic values are satisfied, the subsequent twisting properties and heat treatment after adhesive embedding can be performed on the same level as drawn yarn without using the intermediately oriented yarn, and the drawing process can be incorporated into the heat treatment process, making it possible to omit steps. It will become. It is particularly preferable that the intermediately oriented yarn has a breaking elongation of 40 to 6 ON. In addition, as mentioned above, the intermediately oriented yarn has crystallinity and a specific cutting elongation, and the degree of crystallinity and degree of orientation (△
It is preferable that n) satisfy the following relationship. Xx=2.4 In the present invention, the intermediately oriented yarn must be melt-spun at a spinning speed of VC3500ml or more for 1 minute because it must have the above-mentioned characteristics. Obtain it. The limit GK whose main component is ethylene terephthalate is 0.
95-1.5 polyester or intrinsic viscosity 0.7-0
．． The polyester of No. 9 is reacted with a polymerization accelerator, melted and transported by a conventional method, and the fineness after drawing from a spinneret is 1 to 2 Qd.
Dispense it onto the yarn as shown in e, and immediately cool it down by tilting it immediately after discharging it, or
The material is kept at a temperature below the melting point up to the crystallization initiation temperature, or delayed cooling is performed by leaving it in a heated atmosphere at a temperature above the melting point for a period of time. after that. When cooling and solidifying the discharged filaments, it is useful to cool and solidify under the following conditions. X is the distance from the spinneret surface to the cooling air blowing surface, which is 45
0 m or less. y is the length of the cooling air, which is 100 to 500 Tomimaro, and Q is the amount of cooling air, which is 2 to 6N? F! ”/min. Then, after cooling and solidifying as described above, an oil agent was applied, and 350
Pick up at a speed of 0 m/min or more. The oil can be applied by any method such as an oiling roller method or a spray method. It is possible to apply a general textile oil as the oil, but in fields where adhesion with combs is considered a lil, it is recommended to apply a surface treatment agent to improve adhesion. It is for the shoulder. By using the above-mentioned intermediate yarn and carrying out stretching heat treatment after cording as described below, a hood with the desired durability, particularly excellent fatigue resistance, can be obtained. Further durability can be imparted by biasing the chemical durability to J4 in order to prevent strength deterioration at high temperatures due to heat generation. For this purpose, it is preferable to apply a carboxyl end capping technique, which is usually applied to polyester fibers. That is, it is particularly preferable that the carboxyl terminal concentration is 10 equivalents/ton or less. Various methods can be employed to reduce the terminal carboxyl group cap to 10 equivalents/106 grams of polymer or less. For example, tl+ A method of reacting phenyl glycidyl ether with a molten polyester as disclosed in Japanese Patent Publication No. 44-2791 (2) A method of reacting a molten polyester with a kneaded polyester carbonate as in Japanese Patent Publication No. 45-41235 Method + 31 Method of reacting polyester with ethylene oxide as in Japanese Patent Publication No. 47-12891 (4) Method of reacting oxalic acid polyester with polyester and glyfur ester of oxalic acid as in Japanese Patent Publication No. 48-35953 +51 ll # Publication No. 48-41713,
A method of reacting a polyester with a cyclic carbonate (method of reacting a polyester with a diaryl oxalate and/or a diaryl malonate and a diaryl carbonate as in 61 Japanese Patent Publication No. 49-5233) (7) U.S. Patent No. 3,193,522 A method of reacting a carbodiimide with a polyester (8) as described in JP-A-55-145734 (a method of reacting a biscyclic imino ether, etc.) may be adopted as needed depending on the desired intrinsic viscosity and amount of terminal carboxyl groups. In particular, it is possible to avoid coloring the resulting fibers, prevent foaming due to decomposition of additives during spinning, and reduce the amount of terminal carboxyl groups to 10 fijk/10'g polymer or less without reducing the degree of polymerization. Next, in the present invention, it is necessary to twist the above-mentioned polyester fibers with a twist coefficient of 1,500 to 7,100 to form a twisted cord. Here, the twist coefficient ak is defined by the following formula. k=Tx% However, T is the number of twists per 10 cords, and D is the denier of the raw cord.The twist coefficient is set so that the twist coefficient of the hood after the subsequent adhesive treatment and stretching heat treatment is 900 to 25001C. If the twist coefficient is less than 1,500, the fatigue resistance will not be as high as that of the light, and if it exceeds 7,100, the strength and low shrinkage properties will not be sufficient.
Heat treat at ℃. The tension during this heat treatment is 1.0 to 2.0
It is necessary to carry out the heat treatment while substantially causing stretching within the range of 1/de. Here, the adhesive treatment is performed using a mixture of resorcinol-formalin-rubber latex (RFL) and an epoxy compound or @PEXUL'' (ICI Shasai) in a similar manner to martial arts. Zone co-processing temperature is 235-2
The temperature is 50°C. Below 235°C, the adhesion between the fiber cord and tire rubber is poor (and above 250°C, the strength of the treated cord is greatly reduced. Also, when the tension after heat treatment is below 1.0&/de, the adhesive strength between the fiber cord and tire rubber is poor). If the modulus exceeds 2.01)/de, not only will it not be possible to obtain a low-shrinkage cord, but stable cord processing will not be possible, and sometimes cord breakage will occur, which is inappropriate. It is preferable to perform the heat treatment without substantially stretching 1.4 to 2.0 under tension during the heat treatment. The polyester cord obtained by simultaneously satisfying 1c of the method detailed above has a sum of intermediate elongation Ei at a load of 2.01/de and dry heat shrinkage rate S of Ei+S≦6.0, but S≦2. It has a high monaural value of .5 and exhibits extremely low contractility. Here, the dry heat shrinkage rate is at a temperature of 175°C, and is based on J I S L 1017-1963 (5, 12
). In addition, the polyester cord produced by the method of the present invention has a strength of 5. It has OJ'/de or more and elongation of 129 or more, and the heat generation temperature in the rubber structure is lower than that of conventional polyester cords for rubber reinforcement, and the fatigue resistance is significantly improved. Example 97 parts of dimethyl terephthalate (parts by weight), 69 parts of ethylene glycol, 034 parts of calcium acetate monohydrate Q, and 0.025 parts of antimony trioxide were placed in an autoclave. 80-230℃
After removing methanol to remove insects as a result of ester father exchange, add 0.05 part of a 50% aqueous solution of )T, PO, and heat to raise the temperature to 280 ''[' and gradually reduce the pressure. The pressure in the reaction system was reduced to 0 over approximately 1 hour.
．． 2wJ1) and continued the polymerization reaction for 2 hours and 20 minutes to obtain an intrinsic viscosity of 0.85 and a terminal carboxyl group:! 128 z,
A polymer of 'io' gram polymer was obtained. 100 parts of this polymer chip was dry-punched with 2,2-bis(2-oxazoline) (CF) as shown in Table 1, then melted and transported at about 300°C, with a pore diameter of 0.6 m and a pore number of 25.
After being discharged from 0 spinnerets, the discharged yarn was maintained at the cooling conditions listed in Table 1, and then cooled at 25° C. for 300 hours. Cool and solidify while spraying ONm for 7 minutes.
Thereafter, an oil agent was applied using an oiling roller, and the film was rolled up at the speed shown in Table 1. The properties of this intermediately oriented undrawn fiber are shown in Table 1. Next, these intermediately oriented undrawn fibers were given the twist numbers listed in Table 1 to form green cords. Glue this raw cord to CRFL
liquid) and subjected to tension heat treatment at 245°C for 2 minutes. The characteristics of this treated hood, as well as tube fatigue resistance and heat resistance strength after embedding it in rubber and vulcanizing it, were measured. The results are also listed in Table 1. Note that the characteristic values of the treated cords were measured by the following method. (1) The load-stretching curve is JISL1017-1963 (
5,4') Compliant with K. 12) Dry heat 175℃ shrinkage rate is JISL1017-1
963(5,12). 13+ Tube life is JISL1017-1963
. 1.3.2. Compliant with IA law. However, the bending angle is 90
'. (4) Heat resistance and strength were determined by immersing raw hoods in RFL adhesive solution and heat-treating them at 245° C. for 2 minutes under tension. This treatment hood was embedded in a vulcanization mold and accelerated vulcanization was carried out at 170° C. and a pressure of 50 kQ/clI for 120 minutes.The treated cord was then taken out and its strength was measured. Procedural Amendment July 1985 / 2L1 Patent Publication Office 1, Indication of Case Patent Application No. 1988-88788 2, Name of Invention Process for Manufacturing Polyester Stel Cord 3, Supplement 1 Relationship to the incident Patent applicant No. 1 Y1 Minamihonmachi, Higashi-ku, Osaka (300) Teijin Ltd. Representative name: Okamoto Sashibe 4, Agent (1) In the specification, page 2, line 6, it says [Tire coat]. Correct it to 1 tie x 7 code]. (2) On page 3, line M17, "Performance" is corrected to "Performance." (3) On page 4, lines 9 and 10, “Punto Bulge”
Correct the statement to "Punto Bulge." (4) On page 6, lines 17 to 18, it is stated that “3500 m
7 minutes" should be corrected to 1", preferably 2500 m/min. On page 8, line 16, the phrase "3500 rn/min" is revised to "preferably 2500 m7 min" (1F). (7) On page 8, lines 17 to 18, the words ``although necessary'' have been corrected to ``although it is preferable.'' (8) On page 9, line 7 of the same page, the phrase ``saratote'' is corrected to ``sarasete J.'' (9) On page 9, line 17 of the same page, the phrase ``l 3500 m1 minute'' is changed to ``preferably.'' is 2,500 m and 7 minutes.'' (10) On page 10, line 13 of the same page, the phrase “apply” is corrected to “apply J.” (1)) On page 13, line 12 of the same page, the phrase “normalizing zone” is changed to [ Normalizing Zone]. (12) On page 13, lines 13 and 15, “250
℃" should be corrected to 1260℃. (13) "1J" in the Experiment No. column of Table 1 on page 18.
1) Change “4” and “7” to “1 (ratio)” and “4 (ratio)” respectively.
J and "7 (ratio) J" is corrected. (14) The following note is inserted under Table 1 on page 18 of the same. "Note (ratio) indicates a comparative example. × indicates the invention Indicates that it is out of range.”

Claims (3)

[Claims] (1) Made of polyester whose main structural unit is ethylene terephthalate and whose intrinsic viscosity is 0.90 or more, whose birefringence is 0.09 to 0.14 and whose crystal melting point is 27.
Polyester fibers with a twist coefficient of 1500 to 7 at 0°C or higher
The yarn is twisted at a temperature of 100°C to form a twisted yarn cord, and after being treated with an adhesive, the temperature is 235~260°C and the tension is 1.0~2.0g/
A method for producing a polyester cord, characterized in that heat treatment is carried out with substantial stretching within a range of de. (2) The cutting elongation of the polyester fiber used for the twisted yarn is 4
The method for producing a polyester cord according to claim (1), wherein the polyester cord has a content of 0 to 60%. (3) The method for producing a polyester cord according to claim (1) or (2), wherein the terminal carboxyl group concentration of the polyester fiber to be used as the twisted yarn is 10 equivalents/ton or less.