KR20210125933A - Adhesive composition for tire cord, tire cord, and tire - Google Patents

Abstract

The present invention relates to an adhesive composition for a tire cord, a tire cord comprising an adhesive layer formed from the adhesive composition, and a tire comprising the tire cord. Accordingly, the present invention provides an environmentally friendly adhesive composition for a tire cord capable of increasing the strength of the tire cord while improving the adhesive force between the tire rubber and tire cord.

Description

Adhesive composition for a tire cord, a tire cord, and a tire TECHNICAL FIELD

The present invention relates to an adhesive composition for a tire cord, a tire cord comprising an adhesive layer formed from the adhesive composition, and a tire comprising the tire cord.

Fiber reinforcement is used to reinforce the strength of the rubber structure.

For example, in a rubber tire, polyester fiber, polyamide fiber, polyamide fiber, polyvinyl alcohol fiber, or the like may be used as a fiber reinforcing material.

Since some fibers have poor adhesion to rubber, the adhesion between rubber and fibers is supplemented after an adhesive is coated on the surface of the fibers.

For example, an adhesive is applied to the polyester fiber to improve the adhesion between the raw cord for the tire cord and the rubber for the tire.

In the adhesive composition for the above use, the adhesive composition generally includes a rubber (or latex) containing a resorcinol-formaldehyde (hereinafter referred to as "RF") resin or a component derived therefrom.

However, RF resin is harmful to the human body and the environment, so its use is strictly regulated. Accordingly, research on the adhesive composition that does not include an RF resin is steadily progressing.

The adhesive composition may be applied on the fiber reinforcement by immersion or spraying. In order to ensure that the effect of improving physical properties according to the application of the adhesive composition can be sufficiently and uniformly expressed, the adhesive composition must have appropriate flowability and the solids must be uniformly dispersed.

On the other hand, the adhesive composition improves the adhesion between the fiber reinforcement material and the rubber for a tire, but the stiffness of the fiber reinforcement material may be changed due to the application of the adhesive composition. When the rigidity of the fiber reinforcing material becomes greater than necessary, the strength of the fiber reinforcing material may be reduced, and as a result, physical properties of the tire including the fiber reinforcing material may be deteriorated.

The present invention provides an environmentally friendly adhesive composition for a tire cord capable of improving the strength of the tire cord while improving the adhesion between the tire rubber and the tire cord.

The present invention provides a tire cord having high adhesion to tire rubber and improved strength.

Further, the present invention provides a tire including the tire cord.

Hereinafter, a method for producing para-aramid fibers according to an embodiment of the present invention will be described in more detail.

Unless explicitly stated herein, terminology is for the purpose of referring to specific embodiments only, and is not intended to limit the present invention.

As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite.

As used herein, the meaning of “comprising” specifies a particular characteristic, region, integer, step, operation, element and/or component, and other specific characteristic, region, integer, step, operation, element, component, and/or group. It does not exclude the existence or addition of

According to the continuous research results of the present inventors, the reaction product of the epoxy resin and the diol compound has a larger molecular size than the original epoxy resin and has a relatively high soft segment ratio in the molecule. Accordingly, the adhesive composition for a tire cord including the reaction product can be applied to any fiber substrate to provide excellent adhesion and an appropriate level of stiffness, and enables the expression of improved strength.

According to one embodiment of the invention,

reaction products of epoxy resins and diol compounds;

isocyanate compounds;

latex;

Water-dispersible polyurethane

amine compounds; and

menstruum

There is provided an adhesive composition for a tire cord comprising a.

The adhesive composition for a tire cord does not include an RF resin, so it does not cause environmental pollution and enables improvement of a working environment.

The adhesive composition for a tire cord includes a reaction product of an epoxy resin and a diol compound.

The reaction product of the epoxy resin and the diol compound has an epoxy reactive group to improve reactivity and adhesion of the adhesive composition. The reaction product forms a three-dimensional network structure in the adhesive layer (or coating layer) formed by the adhesive composition together with an isocyanate compound to be described later to improve adhesion and stability of the adhesive layer (or coating layer).

In particular, the reaction product of the epoxy resin and the diol compound has a larger molecular size than the original epoxy resin and has a relatively high ratio of soft segments in the molecule. Thus, the reaction product allows the adhesive composition to be applied to any fibrous substrate to exhibit good adhesion and an appropriate level of stiffness.

Here, the soft segment refers to a segment including a carbon-carbon chain introduced into a molecule of the reaction product from the diol compound. The hard segment refers to a segment formed by reaction of an epoxy reactive group with an isocyanate compound to be described later.

A fiber reinforcement to which an epoxy resin having a relatively high ratio of hard segments in a molecule is applied may exhibit excessive stiffness, which may cause a decrease in strength of the tire cord.

According to an embodiment, the reaction product may be a reaction product of the epoxy resin and the diol compound in a weight ratio of 1:0.1 to 1:5.

Preferably, in the reaction product, the epoxy resin and the diol compound are 1:0.1 or more, or 1:0.5 or more; And 1: 5.0 or less, or 1: 4.5 or less, or 1: 4.0 or less, or 1: 3.5 or less, or 1: 3.0 or less may be reacted in a weight ratio.

Specifically, the reaction product is the epoxy resin and the diol compound 1: 0.1 to 1: 5.0, or 1: 0.1 to 1: 4.5, or 1: 0.1 to 1: 4.0, or 1: 0.1 to 1: 3.5, or 1: 0.1 to 1: 3.0, or 1: 0.5 to 1: 5.0, or 1: 0.5 to 1: 4.5, or 1: 0.5 to 1: 4.0, or 1: 0.5 to 1: 3.5, or 1: 0.5 to It may be a reaction in a weight ratio of 1:3.0.

In order for the reaction product to have a high soft segment ratio in the molecule, the diol compound is preferably applied in a weight ratio of 1:0.1 or more relative to the epoxy resin.

However, when the diol compound is applied in excess, the epoxy equivalent of the reaction product may decrease, thereby reducing the adhesiveness of the adhesive composition. In addition, when the diol compound is applied in an excessive amount, the molecular weight of the reaction product may become excessively large, thereby reducing adhesiveness of the adhesive composition. Therefore, the diol compound is preferably applied in a weight ratio of 1: 5.0 or less compared to the epoxy resin.

The reaction product of the epoxy resin and the diol compound preferably has a weight average molecular weight (Mw) of 700 to 1200 g/mol, or 700 to 1150 g/mol, or 730 to 1150 g/mol.

In this specification, the weight average molecular weight means the weight average molecular weight in terms of polystyrene measured by the GPC method. In the process of measuring the polystyrene equivalent weight average molecular weight measured by the GPC method, a commonly known analyzer and a detector such as a differential refraction detector and a column for analysis may be used, and the temperature generally applied Conditions, solvents, and flow rates can be applied.

As a specific example of the measurement conditions, a polymer resin such as a polyurethane resin is dissolved in tetrahydrofuran (THF) to a concentration of 1.0 (w/w)% in THF (about 0.5 (w/w)% based on solid content) to 0.45 After filtration using a syringe filter of μm pore size, 20 μl was injected into GPC, tetrahydrofuran (THF) was used for the mobile phase of GPC, and was introduced at a flow rate of 1.0 mL/min, and the column was Agilent PLgel 5 μm Guard. (7.5 x 50 mm) and Agilent PLgel 5㎛ Mixed D (7.5 x 300 mm) are connected in series. As a detector, the Agilent 1260 Infinity Ⅱ System, RI Detector can be used to measure at 40 ℃.

This is a polystyrene standard sample (STD A, B, C, D) in which polystyrene having various molecular weights is dissolved in tetrahydrofuran at a concentration of 0.1 (w/w)% as follows, filtered with a syringe filter of 0.45 μm pore size and then GPC The weight average molecular weight (Mw) value of the polymer can be obtained by using a calibration curve formed by injection into the .

STD A (Mp): 791,000 / 27,810 / 945

STD B (Mp): 282,000 / 10,700 / 580

STD C (Mp): 126,000 / 4,430 / 370

STD D (Mp): 51,200 / 1,920 / 162

According to an embodiment, the reaction product of the epoxy resin and the diol compound may be included in the adhesive composition for a tire cord in an amount of 0.5 to 10.0 wt%.

Preferably, the reaction product is 0.5 wt% or more, or 1.0 wt% or more, based on the total weight of the adhesive composition; And 10.0 wt% or less, 5.0 wt% or less, or 4.5 wt% or less, or 4.0 wt% or less, or 3.5 wt% or less, or 3.0 wt% or less may be included.

Specifically, the reaction product is 0.5 to 10.0% by weight, or 0.5 to 5.0% by weight, or 0.5 to 4.5% by weight, or 0.5 to 4.0% by weight, or 0.5 to 3.5% by weight based on the total weight of the adhesive composition, or 0.5 to 3.0% by weight, or 1.0 to 10.0% by weight, or 1.0 to 5.0% by weight, or 1.0 to 4.5% by weight, or 1.0 to 4.0% by weight, or 1.0 to 3.5% by weight, or 1.0 to 3.0% by weight. have.

In order to prevent a decrease in the reactivity and crosslinking degree of the adhesive composition, the reaction product is preferably included in an amount of 0.5% by weight or more based on the total weight of the adhesive composition.

However, when the reaction product is applied in excess, the degree of curing of the adhesive composition may increase due to excessive reactivity, so that the adhesive strength of the adhesive layer formed by the adhesive composition may be reduced. Therefore, the reaction product is preferably included in an amount of 10.0 wt% or less based on the total weight of the adhesive composition.

The type of the epoxy resin is not particularly limited, and a conventional one in the art to which the present invention pertains may be applied.

As a non-limiting example, the epoxy resin may include at least one selected from the group consisting of a bisphenol-based epoxy resin, a novolak-based epoxy resin, and an oxazolidone-based epoxy resin. The bisphenol-based epoxy resin may be a bisphenol A-type epoxy resin, a bisphenol F-type epoxy resin, or the like. The novolak-based epoxy resin may be a phenol novolak-type epoxy resin, a cresol novolak-type epoxy resin, or the like. In addition, commercial products such as EX614B of NAGASE, KETL6000 of Kolon, CL16 of Ipox chemical, GE500 of Raschig, etc. may be used as the epoxy resin.

The epoxy resin may have an epoxy equivalent of 120 to 600 in consideration of its reactivity and adhesiveness of the adhesive composition.

As the diol compound, a linear or branched aliphatic diol compound having 3 to 8 carbon atoms may be preferably used.

As a non-limiting example, the diol compound may include at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, and 1,6-hexanediol. may include

Meanwhile, the adhesive composition for a tire cord includes an isocyanate compound.

The isocyanate compound serves as a crosslinking agent.

The isocyanate compound reacts with the reaction product to form a three-dimensional network structure in the adhesive layer (or coating layer) formed by the adhesive composition to improve adhesion and stability of the adhesive layer (or coating layer).

The isocyanate compound may be an isocyanate compound having a phenyl group. Specifically, the isocyanate compound may include at least one selected from the group consisting of methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI).

In addition, a blocked isocyanate_compound may be applied as the isocyanate compound. The blocked isocyanate compound may be obtained by adding a known blocking agent to the isocyanate compound.

Examples of the blocking agent include phenol, thiophenol, chlorophenol, cresol, resorcinol, p-sec-butylphenol, p-tert-butylphenol, p-sec-amylphenol, p-octylphenol, p-nonylphenol, etc. phenols; secondary or tertiary alcohols such as isopropyl alcohol and tert-butyl alcohol; secondary amines such as diphenylamine and xylidine; phthalic acid imides; lactams such as ?-valerolactam; caprolactams such as ε-caprolactam; active methylene compounds such as malonic acid dialkyl ester, acetylacetone, and acetacetic acid alkyl ester; oximes such as acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime; basic nitrogen compounds such as 3-hydroxypyridine; Acidic sodium sulfite and the like may be used.

As the blocked isocyanate compound, an aqueous dispersion product such as IL-6 manufactured by EMS and DM-6500 manufactured by MEISEI Chemical may be used.

According to an embodiment, the isocyanate compound may be included in an amount of 1.0 to 20.0 wt% in the adhesive composition for a tire cord.

Preferably, the isocyanate compound is 1.0 wt% or more, or 2.0 wt% or more, or 3.0 wt% or more, based on the total weight of the adhesive composition; And, 20.0 wt% or less, or 18.0 wt% or less, or 16.0 wt% or less, or 15.0 wt% or less, or 14.0 wt% or less, or 12.0 wt% or less, or 10.0 wt% or less may be included.

Specifically, the isocyanate compound is 1.0 to 20.0% by weight, or 1.0 to 18.0% by weight, or 1.0 to 16.0% by weight, or 1.0 to 14.0% by weight, or 1.0 to 12.0% by weight based on the total weight of the adhesive composition, or 1.0 to 10.0% by weight, or 2.0 to 20.0% by weight, or 2.0 to 18.0% by weight, or 2.0 to 16.0% by weight, or 2.0 to 14.0% by weight, or 2.0 to 12.0% by weight, or 2.0 to 10.0% by weight, or 3.0 to 20.0% by weight, or from 3.0 to 18.0% by weight, or from 3.0 to 16.0% by weight, or from 3.0 to 14.0% by weight, or from 3.0 to 12.0% by weight, or from 3.0 to 10.0% by weight.

In order to allow sufficient crosslinking in the adhesive layer formed by the adhesive composition, the isocyanate compound is preferably included in an amount of 1.0 wt % or more based on the total weight of the adhesive composition.

However, when the isocyanate compound is applied in excess, an increase in the degree of curing of the adhesive layer and an increase in fatigue of the tire cord may be induced due to an excessive crosslinking reaction. Therefore, the isocyanate compound is preferably included in an amount of 20.0 wt% or less based on the total weight of the adhesive composition.

Meanwhile, the adhesive composition for a tire cord includes latex.

The latex is an adhesive component, and imparts adhesion to the adhesive layer formed by the adhesive composition. In particular, the latex improves affinity and adhesion between the adhesive layer and the rubber composition.

The latex is selected from the group consisting of vinylpyridine-styrene-butadiene-based copolymer latex and its modified latex, styrene-butadiene latex and its modified latex, natural rubber latex, acrylic acid ester copolymer latex, butyl rubber latex, and chloroprene rubber latex It may include one or more types.

Preferably, as the latex, a latex prepared by dispersing a rubber component of the same type as the rubber component to be mixed in the rubber composition for a tire in water or an organic solvent may be used.

As a non-limiting example, commercial products such as Denaka's LM-60, APCOTEX's VP-150, Nippon A&L's VB-1099, Closlen's 5218 and 0653 may be used as the latex.

According to an embodiment, the latex may be included in an amount of 1.0 to 30.0 wt% in the adhesive composition for a tire cord.

Preferably, the latex is 1.0 wt% or more, or 5.0 wt% or more, or 10.0 wt% or more, based on the total weight of the adhesive composition; And, 30.0 wt% or less, or 25.0 wt% or less, 20.0 wt% or less, or 16.0 wt% or less may be included.

Specifically, the latex is 1.0 to 30.0 wt%, or 1.0 to 25.0 wt%, or 1.0 to 20.0 wt%, or 1.0 to 16.0 wt%, or 5.0 to 30.0 wt%, or 5.0 to 30.0 wt%, based on the total weight of the adhesive composition to 25.0% by weight, or 5.0 to 20.0% by weight, or 5.0 to 16.0% by weight, or 10.0 to 30.0% by weight, or 10.0 to 25.0% by weight, or 10.0 to 20.0% by weight, or 10.0 to 16.0% by weight. .

In order to allow sufficient adhesion and rubber affinity to be expressed in the adhesive layer formed by the adhesive composition, the latex is preferably included in an amount of 1.0 wt % or more based on the total weight of the adhesive composition.

However, when the latex is applied in excess, the adhesive layer formed by the adhesive composition cannot be cured and becomes very sticky, thereby reducing the manufacturing efficiency of the tire cord. Therefore, the latex is preferably included in an amount of 30.0 wt% or less based on the total weight of the adhesive composition.

Meanwhile, the adhesive composition for a tire cord includes water-dispersed polyurethane.

In general, polyurethane is manufactured and distributed in a dissolved state in an organic solvent. However, organic solvents are harmful to the human body and the environment, and there is a risk of ignition by fire. From this point of view, the water-dispersed polyurethane, which is not an organic solvent-based polyurethane, but a water-based polyurethane, may be preferably used.

In particular, the water-dispersible polyurethane protects or captures an amine compound, which is a curing agent, which will be described later, so that the adhesive layer formed by the adhesive composition can be stably cured. Furthermore, the water-dispersible polyurethane has excellent affinity for rubber, so that the rubber composition for a tire can be stably attached to the adhesive layer. In addition, the water-dispersible polyurethane may impart excellent abrasion resistance and elasticity to the adhesive layer.

The water-dispersed polyurethane may include, for example, 20 to 60% by weight of polyurethane and 40 to 80% by weight of water.

The polyurethane is a high molecular compound having a urethane bond in a molecule, and may generally be formed by a reaction between a diisocyanate compound and a polyol.

The water-dispersed polyurethane is at least one selected from the group consisting of polycarbonate-based urethane, polyester-based urethane, polyacrylic urethane, polytetramethylene-based urethane, polycaprolactone-based urethane, polypropylene-based urethane, and polyethylene-based urethane. and urethane.

According to an embodiment, the polyurethane included in the water-dispersed polyurethane may have a weight average molecular weight (Mw) of 250,000 to 350,00 g/mol.

Specifically, the weight average molecular weight (Mw) of the polyurethane is 250,000 g/mol or more, or 255,000 g/mol or more, or 260,000 g/mol or more, or 265,000 g/mol or more, or 270,000 g/mol or more, or 275,000 g/mol or more, or 280,000 g/mol or more, or 285,000 g/mol or more, or 290,000 g/mol or more, or 295,000 g/mol or more, or 300,000 g/mol or more, or 305,000 g/mol or more.

And, the weight average molecular weight (Mw) of the polyurethane is, for example, 350,00 g/mol or less, or 345,000 g/mol or less, or 340,000 g/mol or less, or 335,000 g/mol or less, or 330,000 g /mol or less, or 325,000 g/mol or less, or 320,000 g/mol or less, or 315,000 g/mol or less, or 310,000 g/mol or less, or 305,000 g/mol or less, or 300,000 g/mol or less.

When the weight average molecular weight range of the polyurethane is satisfied, adhesion, abrasion resistance and elasticity according to the use of the water-dispersible polyurethane may be secured.

As long as the weight average molecular weight is satisfied, the method for producing the water-dispersed polyurethane is not particularly limited. For example, the water-dispersed polyurethane can be obtained by neutralizing a prepolymer having units derived from polyester polyol, diol, and diisocyanate with a neutralizing agent and then stirring with distilled water.

According to an embodiment, the water-dispersible polyurethane may be included in an amount of 0.5 to 10.0 wt% in the adhesive composition for a tire cord.

Preferably, the water-dispersible polyurethane is 0.5 wt% or more, or 1.0 wt% or more, or 1.5 wt% or more, based on the total weight of the adhesive composition for a tire cord; And, 10.0 wt% or less, or 8.0 wt% or less, or 5.0 wt% or less may be included.

Specifically, the water-dispersed polyurethane is 0.5 to 10.0% by weight, or 0.5 to 8.0% by weight, or 0.5 to 8.0% by weight, or 0.5 to 5.0% by weight, or 1.0 to 10.0% by weight based on the total weight of the adhesive composition for a tire cord. 10.0% by weight, or 1.0 to 8.0% by weight, or 1.0 to 8.0% by weight, or 1.0 to 5.0% by weight, or 1.5 to 10.0% by weight, or 1.5 to 8.0% by weight, or 1.5 to 8.0% by weight, or 1.5 to 5.0 It may be included in weight %.

In order to achieve the effect of improving the adhesive strength, the water-dispersible polyurethane is preferably included in an amount of 0.5 wt % or more based on the total weight of the adhesive composition for a tire cord.

However, when the water-dispersible polyurethane is applied in excess, the adhesive composition may not cure the adhesive layer formed by the adhesive composition and become very sticky, thereby reducing the adhesive strength and durability of the adhesive layer. Therefore, the water-dispersible polyurethane is preferably included in an amount of 10.0 wt% or less based on the total weight of the adhesive composition for tire cords.

Meanwhile, the adhesive composition for a tire cord includes an amine compound.

The amine compound acts as a curing agent. Curing of the adhesive composition may be made or promoted by the amine compound, and a stable adhesive layer may be formed by the adhesive composition.

The type of the amine compound is not particularly limited, and an amine compound known to be used as a curing agent may be applied. For example, the amine compound may include at least one selected from the group consisting of aliphatic amines and alicyclic amines.

As a non-limiting example, as the amine compound, commercially available products such as DAEJUNG's Piperazine, Kukdo Chemical's G640, and Huntsman's HK511 may be used.

According to an embodiment, the amine compound may be included in an amount of 0.1 to 10.0 wt% in the adhesive composition for a tire cord.

Preferably, the amine compound is 0.1 wt% or more, or 0.2 wt% or more, or 0.3 wt% or more, based on the total weight of the adhesive composition for a tire cord; And, 10.0 wt% or less, or 5.0 wt% or less, or 3.0 wt% or less, or 2.5 wt% or less, or 2.0 wt% or less, or 1.5 wt% or less, or 1.0 wt% or less may be included.

Specifically, the amine compound may be present in an amount of 0.1 to 10.0 wt%, or 0.1 to 5.0 wt%, or 0.1 to 3.0 wt%, or 0.1 to 2.5 wt%, or 0.1 to 2.0 wt%, based on the total weight of the adhesive composition for a tire cord. %, alternatively from 0.1 to 1.5% by weight, alternatively from 0.1 to 1.0% by weight, alternatively from 0.2 to 10.0% by weight, alternatively from 0.2 to 5.0% by weight, alternatively from 0.2 to 3.0% by weight, alternatively from 0.2 to 2.5% by weight, alternatively from 0.2 to 2.0% by weight or 0.2 to 1.5% by weight, or 0.2 to 1.0% by weight, or 0.3 to 10.0% by weight, or 0.3 to 5.0% by weight, or 0.3 to 3.0% by weight, or 0.3 to 2.5% by weight, or 0.3 to 2.0% by weight, Or 0.3 to 1.5% by weight, or 0.3 to 1.0% by weight may be included.

In order to sufficiently cure the adhesive composition, the amine compound is preferably included in an amount of 0.1 wt % or more based on the total weight of the adhesive composition for a tire cord.

However, when the amine compound is applied in excess, the adhesive strength of the adhesive layer formed by the adhesive composition may be reduced due to excessive curing. Therefore, the amine compound is preferably included in an amount of 10.0 wt% or less based on the total weight of the adhesive composition for a tire cord.

Meanwhile, the adhesive composition for a tire cord includes a solvent.

Preferably, water (H ₂ O) may be used as the solvent.

More preferably, demineralized water, distilled water, or the like may be used as the solvent.

According to an embodiment, the solvent may be included in an amount of 60.0 to 85.0 wt % in the adhesive composition for a tire cord.

Preferably, the solvent is 60.0 wt% or more, or 65.0 wt% or more, or 70.0 wt% or more, based on the total weight of the adhesive composition for a tire cord; And, it may be included in 85.0 wt% or less, or 80.0 wt% or less.

Specifically, the solvent is 60.0 to 85.0 wt%, or 60.0 to 80.0 wt%, or 65.0 to 85.0 wt%, or 65.0 to 80.0 wt%, or 70.0 to 85.0 wt%, based on the total weight of the adhesive composition for a tire cord , or 70.0 to 80.0% by weight, or 70.0 to 75.0% by weight, or 65.0 to 70.0% by weight.

In order to ensure mixing and dispersibility of solids, the solvent is preferably included in an amount of 60.0 wt % or more based on the total weight of the adhesive composition for tire cords.

However, when the solvent is applied in excess, it is difficult to form an adhesive layer by the adhesive composition, and it may take a long time to dry. Therefore, the solvent is preferably included in an amount of 85.0 wt% or less based on the total weight of the adhesive composition for a tire cord.

In one example, the content of water in the entire composition may mean the content of water mixed as a solvent.

In another example, the content of water in the entire composition may include not only the content of water mixed as a solvent, but also the content of water mixed with other components such as the water-dispersed polyurethane.

In addition, the adhesive composition for a tire cord may further include conventional additives such as a chain extender, a dispersant, and a heat stabilizer.

The adhesive composition for a tire cord may have a relative viscosity of 2.0 to 3.0 measured at 25° C. using an Ubbelohde viscometer. Preferably, the adhesive composition for a tire cord is 2.00 or more, or 2.20 or more, measured at 25° C. using an Ubbelohde viscometer; and a relative viscosity of 3.00 or less, or 2.85 or less, or 2.80 or less, or 2.77 or less, or 2.75 or less, or 2.70 or less.

Specifically, the adhesive composition for the tire cord is 2.00 to 3.00, or 2.00 to 2.85, or 2.00 to 2.80, or 2.00 to 2.77, or 2.00 to 2.75, or 2.00 to 3.00, or 2.00 to 2.85, or 2.00 to 2.80, or 2.00 to 2.77, or 2.00 to 2.75, or It may have a viscosity of 2.00 to 2.70, or 2.20 to 3.00, or 2.20 to 2.85, or 2.20 to 2.80, or 2.20 to 2.77, or 2.20 to 2.75, or 2.20 to 2.70.

Since the adhesive composition for a tire cord satisfies the above viscosity range, it is possible to secure an appropriate level of pickup rate during the manufacture of a tire cord, improve processability and productivity, and provide excellent adhesion.

On the other hand, according to another embodiment of the invention,

fiber base; and

An adhesive layer formed on the fiber substrate and formed from the above-described adhesive composition for tire cords

A tire cord comprising:

Specific details regarding the adhesive composition for tire cords are replaced with those described above.

The adhesive composition for tire cord is environmentally friendly because it does not contain RF resin or a component derived therefrom. In particular, the adhesive composition for a tire cord may improve the strength of the tire cord while improving the adhesive force between the tire rubber and the tire cord.

As the fiber base material, conventional ones applicable as tire cords in the technical field to which the present invention pertains may be used without particular limitation.

For example, the fiber base may be a raw cord including polyester fibers.

The adhesive layer may be formed by immersing the fiber base in the adhesive composition for a tire cord or spraying the adhesive composition for a tire cord on the fiber base.

The adhesive layer may be formed to have an appropriate thickness to improve the adhesive force between the tire rubber and the tire cord without impairing the physical properties of the fiber substrate.

In manufacturing the tire cord, a method for applying the adhesive composition for a tire cord on the fiber substrate, drying and curing conditions, etc. may be changed within a conventional range as necessary.

According to one embodiment, the method of manufacturing the tire cord may include: a first coating step of immersing the fiber base in a first coating solution and drying to form a first coating layer on the fiber base; And it may include a secondary coating step of immersing the first coated fiber base in a second coating solution and drying to form a second coating layer on the first coating layer.

The first coating solution includes a reaction product of the epoxy resin and a diol compound, and the isocyanate compound. The first coating layer formed by the first coating solution imparts an adhesive activator to the fiber substrate.

The fiber base treated with the first coating solution is dried by heat treatment at a temperature of 100 to 160° C. for 30 to 150 seconds. Accordingly, a first coating layer is formed on the fiber substrate. Then, the fiber substrate is cured by heat treatment at a temperature of 200 to 260 ℃ for 30 to 150 seconds. The first coating layer may be stably formed on the fiber substrate by such heat treatment.

The second coating solution is the above-described adhesive composition for a tire cord.

The first coated fiber base is immersed in the second coating solution and dried by heat treatment at a temperature of 100 to 160° C. for 30 to 150 seconds. Accordingly, the second coating layer is formed on the first coating layer. Then, the fiber substrate is cured by heat treatment at a temperature of 200 to 260 ℃ for 30 to 150 seconds. The second coating layer may be stably formed on the first coating layer by such heat treatment.

Meanwhile, according to another embodiment of the present invention, a tire including the above-described tire cord is provided.

The tire may have a conventional configuration, except for including the aforementioned tire cord.

For example, the tire may include a tread portion; a pair of shoulder portions each continuous on both sides around the tread portion; a pair of sidewall portions continuous to each of the shoulder portions; a pair of bead portions continuous to each of the sidewall portions; a carcass layer formed inside the tread portion, the shoulder portion, the sidewall portion, and the bead portion; the tire cord located inside the carcass layer; a belt part positioned between the inner surface of the tread part and the carcass layer; and an inner liner coupled to the inside of the carcass layer.

According to the present invention, there is provided an environmentally friendly adhesive composition for a tire cord capable of improving the strength of the tire cord while improving the adhesion between the tire rubber and the tire cord.

Hereinafter, preferred embodiments are presented to help the understanding of the invention. However, the following examples are only for illustrating the present invention, and do not limit the present invention thereto.

Preparation A

(Preparation of reaction product of epoxy resin and diol compound)

An epoxy resin (EX614B manufactured by NAGASE) and a diol compound were mixed in the weight ratios shown in Tables 1 to 3 below, and stirred at room temperature (20° C.) for 2 hours to obtain reaction products of #1 to #14. However, #C1 below is an epoxy resin (EX614B manufactured by NAGASE) that has not been reacted with a diol compound.

Production Example No. #One #2 #3 #4 #5 epoxy 1.2 1.2 1.2 1.2 1.2 Dior 1,4-butanediol 1,3-propanediol 1,6-hexanediol 1,3-butanediol 2,3-butanediol 0.6 0.6 0.6 0.6 0.6 weight ratio
(Epoxy: Dior) 1: 0.5 1: 0.5 1: 0.5 1: 0.5 1: 0.5 Mw (g/mol) 737 730 751 737 737

Production Example No. #6 #7 #8 #9 #10 epoxy 1.2 1.2 1.2 1.2 1.2 Dior 1,4-butanediol 1,4-butanediol 1,4-butanediol 1,4-butanediol 1,4-butanediol 1.2 1.8 2.4 3.0 3.6 weight ratio
(Epoxy: Dior) 1:1 1: 1.5 1: 2 1: 2.5 1: 3 Mw (g/mol) 782 827 872 917 962

Production Example No. #11 #12 #13 #14 #C1 epoxy 1.2 1.2 1.2 1.2 1.2 Dior 1,4-butanediol 1,4-butanediol 1,4-butanediol 1,4-butanediol - 4.2 4.8 5.4 6.0 0 weight ratio
(Epoxy: Dior) 1: 3.5 1: 4 1:4.5 1: 5 1: 0 Mw (g/mol) 1007 1052 1097 1143 692

Preparation B

(Production of water-dispersed polyurethane)

Polyester polyol (weight average molecular weight 2000 g/mol), diol (1,6-hexanediol), and ionomer (dimethylol butanoic acid) were added to the reactor in a molar ratio of 1: 0.2: 0.8, and 75±5 ° C. and atmospheric pressure. and mixed for 4 hours to obtain a mixture. Methylene diphenyl diisocyanate (MDI) was added to the mixture in a molar ratio of 1:2 relative to the polyester polyol and reacted for 2 hours to prepare a polyurethane prepolymer. The reaction temperature of the prepared polyurethane prepolymer was lowered to 60 °C, and a neutralizing agent (triethanolamine, TEA) was added to a solvent (acetone) and dispersed. Distilled water was added to the neutralized polyurethane prepolymer so that the solid content was 60% by weight and stirred. Then, a chain extender (ethylene diamine) was added in a molar ratio of 1:1 relative to the polyester polyol and stirred to obtain an aqueous dispersion polyurethane (weight average molecular weight: 308,000 g/mol).

Examples 1 to 14 and Comparative Example 1

(Preparation of adhesive composition for tire cord)

Adhesive compositions of Examples 1 to 14 and Comparative Example 1 were prepared by mixing each component at the content (% by weight) shown in Tables 4, 5, and 6 below, and stirring at room temperature (20° C.) for 24 hours.

Each component indicated by the alphabet in Tables 4 to 6 below is as follows.

- E: the reaction product of the epoxy resin and the diol compound according to Preparation A, or the epoxy resin

- I: Isocyanate compound (EMS's IL-6, caprolactam-blocked 4,4'-MDI)

- L: Latex (Closlen's 0653, vinylpyridine-styrene-butadiene copolymer)

-U: Water-dispersed polyurethane according to Preparation B

- A: Amine compound (DAEJUNG's Piperazine)

- S: solvent (demineralized water)

weight% Example 1 Example 2 Example 3 Example 4 Example 5 E
(Production Example No.) 1.8
(#One) 1.8
(#2) 1.8
(#3) 1.8
(#4) 1.8
(#5) I 3.9 3.9 3.9 3.9 3.9 L 15.6 15.6 15.6 15.6 15.6 U 2 2 2 2 2 A 0.4 0.4 0.4 0.4 0.4 S 76.3 76.3 76.3 76.3 76.3

weight% Example 6 Example 7 Example 8 Example 9 Example 10 E
(Production Example No.) 2.4
(#6) 3.0
(#7) 3.6
(#8) 4.2
(#9) 4.8
(#10) I 3.9 3.9 3.9 3.9 3.9 L 15.6 15.6 15.6 15.6 15.6 U 2 2 2 2 2 A 0.4 0.4 0.4 0.4 0.4 S 75.7 75.1 74.5 73.9 73.3

weight% Example 11 Example 12 Example 13 Example 14 Comparative Example 1 E
(Production Example No.) 5.4
(#11) 6.0
(#12) 6.6
(#13) 7.2
(#14) 1.2
(#C1) I 3.9 3.9 3.9 3.9 3.9 L 15.6 15.6 15.6 15.6 15.6 U 2 2 2 2 2 A 0.4 0.4 0.4 0.4 0.4 S 72.7 72.1 71.5 70.9 76.9

Comparative Example 2

(Preparation of adhesive composition for tire cord)

In Example 1, instead of "reaction product of an epoxy resin and a diol compound" (component E) of 1.8 wt% according to #1 of Preparation A, 1.2 wt% and 1,4 of an epoxy resin (EX614B manufactured by NAGASE) - An adhesive composition was prepared in the same manner as in Example 1, except that 0.6 wt% of butanediol was added and stirred together with the I, L, U, A, and S components.

Comparative Example 3

(Preparation of adhesive composition for tire cord)

In Example 1, 1,6-hexanediol-diglycidyl ether 1.8% by weight instead of 1.8% by weight of "reaction product of epoxy resin and diol compound" (component E) according to #1 of Preparation A An adhesive composition was prepared in the same manner as in Example 1, except that the I, L, U, A, and S components were added and stirred.

manufacture of tire cords

Two strands of lower twisted yarn (Z-direction) having a twist number of 360 TPM were prepared using polyester yarn. The two strands of the lower twisted yarns were twisted together (S-direction) with a twist number of 360 TPM to prepare a ply-twisted yarn (1650 dtex/2 yarn). The ply-twisted yarn was used as a raw cord.

After the low cord was immersed in the adhesive composition of the Example or Comparative Example, heat treatment was performed at a drying temperature of 150° C. and a curing temperature of 243° C. for 1 minute, respectively, to prepare tire cord specimens including an adhesive layer formed on the low cord. .

test example

(1) Using an Ubbelohde viscometer, the relative viscosity of the adhesive compositions of Examples and Comparative Examples was measured in a constant temperature water bath at 25° C. according to a conventional method. Before measuring the relative viscosity, add a certain amount of demineralized water to the Ubelode viscometer, and then measure the viscosity of the demineralized water. Based on the measured viscosity of the demineralized water, the relative viscosity (R.V.) of the adhesive compositions of Examples and Comparative Examples is measured.

(2) For the tire cord specimen having an adhesive layer formed by the adhesive composition of the Examples and Comparative Examples, the adhesive force per unit area was evaluated according to the standard test method of ASTM D4393.

Specifically, a 0.6 mm thick rubber sheet, the tire cord specimen, a 0.6 mm thick rubber sheet, the tire cord specimen, and a 0.6 mm thick rubber sheet are sequentially laminated, and 170° C. under a pressure of ^{60 kg/cm 2} Samples were prepared by vulcanization for 15 minutes. The sample was cut to prepare a specimen having a width of 1 inch. For reference, the rubber sheet is a sheet used for a carcass constituting a tire. By using a laminate using such a rubber sheet, the adhesion of the tire cord to the carcass layer can be confirmed.

For the prepared specimen, a peel test was performed at 25° C. at a rate of 125 mm/min using a universal testing machine (Instron) to measure the adhesion of the tire cord to the carcass layer, and the load generated during peeling was measured. The average value of three times was calculated as the adhesive force. The measured values were normalized based on the value of the adhesive layer formed by the adhesive composition of Example 1, and are shown in Tables 7 and 8 below.

(3) For the tire cord specimens having an adhesive layer formed by the adhesive compositions of the Examples and Comparative Examples, the strength and stiffness of the tire cords were evaluated according to the standard test method of ASTM D885/D885M. The measured values were normalized based on the value of the adhesive layer formed by the adhesive composition of Example 1, and are shown in Tables 7 and 8 below.

Relative Viscosity (R.V.) Adhesion (%) Stiffness (%) strong(%) Example 1 2.24 100 100 100 Example 2 2.26 98 105 94 Example 3 2.33 96 94 102 Example 4 2.21 97 102 97 Example 5 2.23 95 106 95 Example 6 2.29 99 97 103 Example 7 2.32 98 94 104 Example 8 2.41 98 92 106 Example 9 2.48 97 89 108 Example 10 2.53 96 88 108 Example 11 2.55 95 84 108 Example 12 2.61 95 81 109 Example 13 2.63 95 79 109 Example 14 2.77 94 78 109

Relative Viscosity (R.V.) Adhesion (%) Stiffness (%) strong(%) Comparative Example 1 2.14 87 124 79 Comparative Example 2 2.01 71 113 81 Comparative Example 3 2.11 59 40 98

Referring to Tables 7 and 8, it is confirmed that the tire cord including the adhesive layer formed by the adhesive composition according to the embodiments may exhibit improved strength while having excellent adhesion to tire rubber.

Claims (15)

reaction products of epoxy resins and diol compounds;
isocyanate compounds;
latex;
Water-dispersible polyurethane
amine compounds; and
menstruum
An adhesive composition for a tire cord comprising a.
The method of claim 1,
0.5 to 10.0% by weight of the reaction product;
1.0 to 20.0% by weight of the isocyanate compound;
1.0 to 30.0% by weight of the latex;
0.5 to 10.0% by weight of the water-dispersible polyurethane;
0.1 to 10.0% by weight of the amine compound; and
60.0 to 85.0% by weight of the solvent
An adhesive composition for a tire cord comprising a.
The method of claim 1,
The reaction product is an adhesive composition for a tire cord, wherein the epoxy resin and the diol compound are reacted in a weight ratio of 1: 0.1 to 1: 5.
The method of claim 1,
The adhesive composition for a tire cord, wherein the epoxy resin comprises at least one selected from the group consisting of a bisphenol-based epoxy resin, a novolak-based epoxy resin, and an oxazolidone-based epoxy resin.
The method of claim 1,
The diol compound is a linear or branched aliphatic diol compound having 3 to 8 carbon atoms, the adhesive composition for a tire cord.
The method of claim 1,
The diol compound includes at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, and 1,6-hexanediol, tire cord adhesive composition for
The method of claim 1,
The isocyanate compound comprises at least one selected from the group consisting of methylene diphenyl diisocyanate, toluene diisocyanate, and hexamethylene diisocyanate, the adhesive composition for a tire cord.
The method of claim 1,
The latex is selected from the group consisting of vinylpyridine-styrene-butadiene-based copolymer latex and its modified latex, styrene-butadiene latex and its modified latex, natural rubber latex, acrylic acid ester copolymer latex, butyl rubber latex, and chloroprene rubber latex An adhesive composition for a tire cord, comprising at least one.
The method of claim 1,
The water-dispersed polyurethane is one or more selected from the group consisting of polycarbonate-based urethane, polyester-based urethane, polyacrylic-based urethane, polytetramethylene-based urethane, polycaprolactone-based urethane, polypropylene-based urethane, and polyethylene-based urethane. Including, the adhesive composition for a tire cord.
The method of claim 1,
The amine compound comprises at least one selected from the group consisting of aliphatic amines and cycloaliphatic amines.
The method of claim 1,
The solvent is water, the adhesive composition for a tire cord.
The method of claim 1,
An adhesive composition for a tire cord, having a relative viscosity of 2.0 to 3.0 measured under 25° C. using an Ubbelohde viscometer.
fiber base; and
An adhesive layer formed on the fiber substrate and formed from the adhesive composition for a tire cord of claim 1
comprising, a tire cord.
14. The method of claim 13,
wherein the fiber base is a raw cord comprising polyester fibers.
A tire comprising the tire cord of claim 13 .