WO2017122964A1 - Polyester fiber, preparation method therefor, and tire cord comprising same - Google Patents

Abstract

The present invention relates to a polyester fiber treated with an eco-friendly secondary treatment liquid, the polyester fiber containing an epoxidized phenolic resin, a maleic anhydride-polybutadiene copolymer, and vinylpyridine latex and styrene-butadiene latex, to a preparation method therefor, and to a tire cord, whereby a high-functional tire cord that can prevent a delamination phenomenon between rubber and fiber, which occurs at the time of high-speed driving of tire, can be prepared by improving the adhesive force, heat resistance, and fatigue resistance of the tire cord.

Description

Polyester fiber, preparation method thereof and tire cord comprising same

The present invention is a secondary treatment liquid comprising a phenolic resin epoxidized on polyester fibers and a copolymer of maleic anhydride-polybutadiene (Riccobond 7004, hereinafter referred to as 'maleic anhydride polybutadiene') The present invention relates to a treated polyester fiber, a method for manufacturing the same, and a tire cord including the same, wherein the adhesive is an environmentally friendly adhesive that does not use environmentally harmful substances such as resorcinol, formalin, and ammonia. By improving the heat resistance and fatigue resistance, it is possible to manufacture a high-performance tire cord that can prevent the peeling of the rubber and fibers generated during high-speed running of the tire.

Tire reinforcements, generally represented by polyethylene terephthalate (polyester), have excellent mechanical strength, modulus of elasticity, dimensional stability and heat resistance, which are important properties of rubber reinforcements, such as rubber composites such as tires, It is widely used as a reinforcing material for belts or hoses. However, there has been a need for higher performance reinforcement materials due to the high performance of automobiles, the development of driving roads, and the severe use of rubber composite materials. However, because the surface of the polyester fiber is inert, the adhesion to rubber is not good, so a method of improving the adhesion of the fiber to rubber by treating the surface of the epoxy and diisocyanate compounds has been studied for a long time.

In the method of bonding the polyester fibers, the fibers are treated with a primary treatment liquid composed of epoxy and diisocyanate or parachlorophenol-based resins, and then secondary treatment with general resorcinol-formalin latex (hereinafter referred to as ``) ''. How to do is known. However, in the case of RFL used in the above method, a reaction is required for a certain time under a caustic soda catalyst to make resorcinol-formaline react to form resorcinol-formalin resin, and reaction of resorcinol-formalin resin with rubber latex. Reaction maturation time of about 24 hours is required to prepare RFL. Therefore, the degree of reaction may vary depending on outdoor conditions such as temperature or humidity, or the application state of RFL may vary according to an oil or fiber property, which may cause non-uniformity of final tire cord properties. In addition, the use of chemicals such as resorcinol, formalin, ammonia and the like can cause environmental problems.

In US Patent No. 2014/0308864 A1, a polyethylene terephthalate fiber is first treated with a mixture of epoxy and blocked isocyanate, and a polyol and an aromatic polyaldehyde are used to prepare a RFL by replacing the resorcinol-formalin resin. A method for producing a polyethylene terephthalate tire cord that is secondary treated to impart adhesion is proposed. However, this method can prepare environmentally friendly adhesives by not using environmentally harmful substances such as resorcinol and formalin, but acetic acid and ethanol are not dissolved in water because the polyalcohol and aromatic aldehydes are not dissolved in water. The adhesive liquid should be prepared in an organic solvent such as a solvent, and the time for the reaction of the adhesive liquid is also long, and the reactivity of the polyphenol and the aromatic aldehyde is relatively low, so that the adhesive strength of the tire cord treated with the adhesive liquid may be low. have.

International patent WO 2014/091429 A1 proposes a method for preparing an adhesive solution to replace resorcinol-formalin resin by using polyglycerol epoxy (RAS100, GE100) and polyamine. However, this method is an inert surface such as aramid fiber, and the crystallinity is very high, the method of expressing the adhesive force by embedding excess epoxy in the material that does not penetrate the epoxy, the epoxy penetration amount when applied to polyethylene terephthalate As the stiffness increases, the disadvantages such as lowering of fairness and lowering of fatigue may occur. In addition, there is a disadvantage in that the adhesive force deviation occurs badly depending on the characteristics of the adhesive rubber.

In addition, the international patent WO2014 / 091376 A1 discloses an environmentally friendly adhesive liquid that can replace the resorcinol-formalin resin using water-soluble acrylic resin (BASF, Acrodur 950) and glycerol epoxy (Nagase Chemtex, EX-313). I'm proposing. This method has the advantage of expressing adhesion even at low Dip Pick Up (DPU) in the case of fibers having a reactor such as nylon 66 and rayon by the reaction of acrylic resin and epoxy, but the surface is inert like polyethylene terephthalate. In case of having a low adhesive strength. In addition, due to the high reactivity of the acrylic resin, the pH should be sensitively adjusted at the time of preparation, and when the pH is not adjusted, coagulum is generated by reaction with latex, and thus adhesives cannot be used. .

Typically, when preparing RFL, which is a secondary treatment liquid, resorcinol, formalin, ammonia, etc., which are environmentally harmful substances, are used. Formalin is registered as a primary carcinogen, and ammonia causes odors. Therefore, the use of resorcinol and formalin in 2019 will be banned in accordance with the REACH regulations in Europe and the United States, and the development of eco-friendly secondary treatment liquid that does not use such environmentally harmful substances is required. It is a reality.

The present invention relates to a polyester fiber treated with an environmentally friendly adhesive liquid on the surface of the polyester fiber, a method of manufacturing the same and a tire cord including the same. Polyester fiber which can manufacture high performance tire cord which can improve the adhesive force, reduce the rigidity of tire cord, improve heat resistance and fatigue resistance, and prevent the peeling phenomenon of rubber and fiber generated at high speed of tire running, its manufacturing method and An object of the present invention is to provide a tire cord including the same.

In order to achieve the above object, the present invention comprises the steps of preparing a first treatment liquid comprising a blocked diisocyanate and an epoxy compound; Passing through the primary treatment liquid while applying a tensile force to the polyester twisted cord; Drying and heat-treating the fibers having passed through the primary treatment liquid; Passing the heat treated polyester fiber through a secondary treatment liquid comprising an epoxidized phenolic resin and a maleic hydride polybutadiene copolymer; And it provides a method for producing a polyester fiber comprising the step of drying and stabilizing the fiber passed through the secondary treatment liquid.

Here, the epoxidized phenol resin and maleic hydride polybutadiene copolymer is preferably 1: 1 to 5: 1 by weight.

The present invention also provides a polyester tire cord, which is produced by the above production method and has the following physical properties.

(1) Initial adhesion with rubber measured by H-test is 16kgf or more, heat resistance adhesion is 10kgf or more

(2) The strength of fiber remaining more than 60% after the fatigue test measured by the disk type fatigue tester

The polyester fiber according to the present invention is a maleic anhydride- which can increase the binding force between the epoxidized phenolic resin and rubber latex and the epoxidized phenolic resin and rubber latex which can interact with rubber as a secondary treatment liquid. By treating with a mixture of polybutadiene copolymers, high heat adhesion, rubber coverage, excellent heat resistance, and fatigue resistance can be exhibited, which makes it possible to manufacture high-performance tires.

In addition, since the secondary treatment solution used in the present invention can be used immediately after mixing, it does not require a reaction aging time and does not use any environmental regulatory substances in the preparation of the treatment solution. By minimizing the degree and enabling the uniform treatment liquid to be attached, it is possible to reduce the manufacturing processability and the production cost, and to provide the treatment liquid for the polyester fiber with improved quality uniformity.

1 is a chemical structure of maleic hydride polybutadiene copolymer (Ricobond 7004) of the secondary treatment solution of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated.

The present invention provides a polyester fiber, a manufacturing method thereof and a tire cord comprising the same.

Method for producing a polyester fiber of the present invention, the present invention comprises the steps of preparing a primary treatment liquid containing a blocked diisocyanate and an epoxy compound; Passing through the primary treatment liquid while applying a tensile force to the polyester yarn cord; Drying and heat-treating the fibers having passed through the primary treatment liquid; Passing the heat treated polyester fiber through a secondary treatment liquid comprising an epoxidized phenol resin and a Maleic Anhydride-Polybutadiene copolymer; And drying and stabilizing the fibers passing through the secondary treatment liquid.

The present invention uses a primary treatment liquid mainly composed of blocked isocyanates and epoxy to bond polyester fibers and rubber. Thereafter, a rubber latex is added to the mixed solution of the epoxidized phenolic resin and the maleic anhydride-polybutadiene copolymer to treat the polyester fiber with a secondary treatment solution capable of interacting with the rubber.

First, in order to prepare a primary treatment solution, 0.5 to 4.0 wt% of diisocyanate blocked, based on 100 wt% of the primary treatment solution, 0.3 to 1.5 wt% epoxy compound, 0.5 to 1.5 wt% vinylpyridine latex, heat additive 0.3 to 0.6% by weight and the balance comprises water.

At this time, the secondary treatment solution may include a maleic anhydride polybutadiene copolymer in order to increase the bonding strength of the rubber latex and the epoxidized phenol resin.

Referring to the step of treating the polyester fiber according to the present invention and the secondary treatment liquid consisting of the epoxidized phenol and maleic hydride polybutadiene copolymer and latex as follows.

When weaving and weaving the polyester fiber produced by the spinning process, the heat treatment will be described as follows. Raw fabric for a tire cord is twisted with a direct weaving machine in the lower direction in the Z direction and the upper edge in two in the S direction, and then weaved using a weaving machine to produce a raw fabric. The dough for tire cords thus prepared is treated with a primary treatment liquid composed of blocked isocyanates and epoxy during the heat treatment process. After the water is removed in the drying zone and the drying temperature is preferably 140 to 180 ℃, it is dried for 20 to 150 seconds. Thereafter, the diisocyanate blocked through heat treatment at a temperature of 160 to 250 ° C. for 20 to 150 seconds is dissociated to give reactivity to the fiber surface through chemical reaction with epoxy.

Then, to prepare a secondary treatment solution, 0.5 to 10% by weight of epoxidized phenolic resin, 0.1 to 3% by weight maleic hydride polybutadiene copolymer, based on 100% by weight of the secondary treatment solution, vinylpyridine latex 15 To 20% by weight, and 0 to 5% by weight of styrene-butadiene latex.

The epoxidized phenolic resin serves to interact with the rubber.

Such epoxidized phenolic resin is a bisphenol-A and epichlorohydrin, a noble and epichlorohydrin, or a high molecular weight polyisocyanate at the end of the epoxy resin synthesized from resol and epichlorohydrin, and organic such as butanol It can be prepared by dispersing in a solvent. Alternatively, the polymerized epoxy is synthesized by addition polymerization of a novolac or resol to a liquid epoxy resin synthesized using bisphenol-A and epichlorohydrin, and then an isocyanate blocked with resorcinol, phenol, caprolactam or the like is prepared. It can be produced by binding to the terminal and dispersing in an organic solvent such as butanol. Another synthesis method is prepared by synthesizing a novolak or resol type epoxy using bisphenol-A and epichlorohydrin and then binding the resorcinol or resorcinol-formalin resin to the ends and dispersing it in an organic solvent. Can be. In addition to the synthesis method described above, a mixed solution may be prepared by applying a very strong shearing force while mixing a novolak or a resol-type epoxy and phenol resin together with water, a co-solvent, and a dispersant and heating. This mixed solution has a uniform dispersibility in the form of small particles and can be maintained in a stable state by the dispersant during the cooling process. At this time, a co-solvent may be used alcohols or ether glycol (Glycol Ether).

The epoxidized phenol resin preferably contains 0.5 to 10% by weight based on 100% by weight of the secondary treatment liquid. When the content of the epoxy compound is less than 0.5% by weight, it is difficult to express sufficient adhesiveness to the fiber by providing sufficient reactivity to the fiber, and when it exceeds 10% by weight, the workability is decreased due to the high rigidity and the fatigue resistance of the cord is reduced. In addition, manufacturing costs will increase.

In addition, the epoxidized phenol resin and the maleic anhydride-polybutadiene copolymer are preferably 1: 1 to 5: 1 by weight. If it is out of the above range, not only sufficient adhesion is not expressed, but also the rigidity is so high that fatigue resistance, which is one of the main required characteristics of the tire cord, is degraded, resulting in deterioration of tire durability.

The content of the vinylpyridine latex is preferably 15 to 20% by weight based on 100% by weight of the primary treatment solution, and when the content of the vinylpyridine latex is 15% by weight or less, sufficient adhesion with rubber may not be expressed. If it is more than 20% by weight, the initial adhesive strength is increased, but the latex layer is formed thick, which may cause peeling phenomenon in the latex layer at a high temperature, and the stiffness is increased due to the high adhesion amount, thereby reducing the fatigue resistance. May cause deterioration in workability or increase in final product defects.

The polyester fiber thus prepared is a mixture of epoxidized phenolic resins and rubber latexes that can interact with rubber and maleic anhydride-polybutadiene copolymers that can increase the bonding strength of the epoxidized phenolic resins and rubber latex. By treating with, high heat adhesive strength, rubber coverage, excellent heat resistance, and fatigue resistance can be expressed, and thus high performance tires can be manufactured.

In addition, since the secondary treatment solution used in the present invention can be used immediately after mixing, it does not require a reaction aging time, and does not use any environmental regulatory substances in the preparation of the treatment solution. By minimizing the influence of the environment to enable uniform deposition of the treatment solution, it is possible to reduce the manufacturing processability and production cost, and to provide a treatment solution for the polyester fiber with improved quality uniformity.

Hereinafter, the present invention will be described in detail by way of Examples, but the following Examples and Experimental Examples are only illustrative of one embodiment of the present invention, and the scope of the present invention is not limited to the following Examples and Experimental Examples. .

Example 1

The primary treatment solution was prepared by mixing 96.5 wt% water, 0.5 wt% epoxy compound, 1.0 wt% diisocyanate, 1.5 wt% vinylpyridine latex, and 0.5 wt% heat resistant additive. It was prepared by adjusting as shown in Table 1. The twisted yarn cord produced by using 1500 denier 2ply of polyester fiber for tire cords as 37 (Twist / 10cm) and 37 (Twist / 10cm) soft water was immersed in the primary treatment liquid while applying a tension of 0.1 g / d. Passed through, dried at 160 ° C. for 2 minutes and heat treated at 245 ° C. After the heat treatment process, the polyester fiber was further subjected to the binding treatment between the epoxidized phenol resin (Allnex Corp. VPW-1942), vinylpyridine latex and styrene-butadiene latex, and the epoxidized phenolic resin and rubber latex. It was made into a polyester tire cord by being impregnated into an adhesive solution consisting of an increaseable maleic hydride polybutadiene copolymer (Ricobond 7004 from Cray Valley), followed by drying at 160 ° C. and stabilization at 245 ° C.

Example 2 Comparative Examples 1,2 and 3

A polyethylene terephthalate tire cord was manufactured in the same manner as in Example 1, except that the content of the secondary treatment liquid composition was adjusted as shown in Table 1 below.

		Comparative Example 1	Comparative Example 2	Comparative Example 3	Example 1	Example 2
Secondary liquid composition (% by weight)	water	76.5	75.0	77.5	76.5	77.5
	Caustic soda	0.1	0.4	-	-	-
	Resorcinol	2.4	3.0	-	-	-
	formalin	0.8	1.2	-	-	-
	Epoxylated Phenolic Resin	-	-	2.5	2.5	4.0
	Ricobond7004	-	-	-	1.0	1.0
	Vinyl pyridine latex	20.0	17.5	20.0	17.5	15.0
	SBR Latex	-	2.5	-	2.5	2.5
	ammonia	0.2	0.4	-	-	-

Experimental Example

The physical properties of the polyester tire cords prepared in Examples 1 to 2 and Comparative Examples 1 to 3, respectively, were evaluated using the following method, and the results are shown in Table 2 below.

(a) Evaluation method of adhesive force (kgf): H-Test

As a method of showing the adhesive strength between the heat treated cord and the rubber, the cord is placed in a rubber block and vulcanized at a pressure of 50 kgf / cm 2 at 160 ° C. for 20 minutes (initial) or 170 ° C. for 60 minutes (heat resistance). Adhesion is measured at a tensile rate of 200 m / min using an elongation type tensile tester. The same test was carried out 10 times to obtain an average value. Other methods were performed according to ASTM D4776-98.

(b) Evaluation method of fatigue resistance

A measure of the resistance value against external stress of the heat treatment cord, which simulates tire running conditions. In the present invention, the evaluation of the disc fatigue resistance was evaluated using Ueshima Seisakusho Co., Ltd. FT-6110. Fatigue test conditions were 6% tensile and 12% compression. After 8 hours of fatigue at 120 ° C at 2500rpm, the cord was collected and the strength was measured. Cord strength measurement method was carried out according to the ASTM D885 method.

	Comparative Example 1	Comparative Example 2	Comparative Example 3	Example 1	Example 2
DPU (%)	2.7	3.1	2.5	2.6	2.8
Initial adhesive force (pull-out, kgf)	16.5	17.0	18.0	19.0	17.5
Pull-out, kgf	9.5	10.0	11.8	12.3	11.5
Endo fatigue (%) Disk	62.3	60.1	69.1	74.7	70.0

As a result of the test results in Table 2, the polyester tire cord according to the present invention (Examples 1 and 2) shows that the adhesion and fatigue resistance are improved as compared with the comparative example without addition of the maleic hydride polybutadiene copolymer. Can be.

Claims (3)

1. Preparing a first treatment liquid comprising a blocked diisocyanate and an epoxy compound;

   Passing through the primary treatment liquid while applying a tensile force to the polyester twisted cord;

   Drying and heat-treating the fibers having passed through the primary treatment liquid;

   Passing the heat treated polyester fiber through a secondary treatment liquid comprising an epoxidized phenolic resin and a maleic anhydride-polybutadiene copolymer; And

   Method for producing a polyester fiber comprising the step of drying and stabilizing the fiber passed through the secondary treatment liquid.
2. The method of claim 1,

   The epoxidized phenol resin and maleic anhydride polybutadiene (Maleic Anhydride-Polybutadiene) copolymer is a method of producing a polyester fiber, characterized in that 1: 1 to 5: 1 by weight.
3. A polyester tire cord comprising the polyester fiber produced by the method according to claim 1 and having the following physical properties.

   (1) Initial adhesion with rubber measured by H-test is 16kgf or more, heat resistance 10kgf or more, and (2) 60% strength strength of fiber after fatigue test measured using a fatigue tester of disk type. More than

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