KR20210126200A - Adhesive composition for tire cord and method for manufacturing rubber reinforcing material using the same - Google Patents

Abstract

The present invention relates to an adhesive composition for a tire cord capable of exhibiting excellent adhesion and heat-resistance adhesion by adjusting the viscosity range by setting dry heat treatment conditions in an appropriate range, and a method of manufacturing a rubber reinforcing material using the same. The present invention comprises: an epoxy compound; an isocyanate compound; latex; water-dispersible polyurethane; an amine compound; and water.

Description

Adhesive composition for tire cord and manufacturing method of rubber reinforcement using same

The present invention relates to an environmentally friendly adhesive composition for rubber reinforcement and a method for manufacturing a rubber reinforcement using the same.

Fiber reinforcement is used to reinforce the strength of the rubber structure. For example, in a rubber tire, polyester fiber, polyamide fiber, aromatic polyamide fiber, polyvinyl alcohol fiber, or the like may be used as a reinforcing material. And, since some fibers have poor adhesion to rubber, the adhesion between rubber and fibers is supplemented after the adhesive is coated on the surface of the fibers. For example, in order to improve the adhesion between the polyester fiber for tire cord (raw cord, raw cord) and the rubber for tire, an adhesive is applied to the polyester fiber.

In the adhesive for the above use, the adhesive generally includes a rubber (or latex) containing resorcinol-formaldehyde or a component derived therefrom. However, RF containing phenols, resorcinol, and formaldehyde, known as a carcinogen, is known to be harmful to the human body. In addition, special post-management and post-treatment costs are sometimes required for the waste adhesive solution containing RF.

On the other hand, as a method of coating the adhesive composition as described above on the fiber reinforcement, a dipping method or a spray method may be considered. In this manufacturing process, each component constituting the adhesive composition should be uniformly mixed and dispersed in the solvent included in the composition. In addition, it is important that the composition in which each component is evenly mixed and dispersed can be uniformly coated on the surface of the fiber reinforcement in an appropriate amount even after being immersed or sprayed. This is because the adhesive strength is not ensured if the composition is not sufficiently mixed or the flowability of the composition is too high due to excessive use of the solvent.

The present invention provides an adhesive composition for an eco-friendly tire cord capable of significantly improving adhesion between tire rubber and a tire cord and heat-resistant adhesion, and a method for manufacturing a rubber reinforcement using the same.

In addition, the present invention provides a tire cord capable of improving tire durability by having high adhesion and heat-resistant adhesion to tire rubber.

In the present specification, an epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; amine compounds; and water, and after drying, the relative viscosity measured at room temperature using a Ubbelode viscometer satisfies the range of 2.85 to 3.25, and an adhesive composition for a tire cord may be provided.

In addition, in the present invention, a first step of immersing in a first coating solution containing an epoxy compound and an isocyanate compound, drying and curing to form a first coating layer on the base substrate; and

a second step of immersing the base substrate having the first coating layer in a second coating solution, drying and curing to form a second coating layer on the first coating layer;

The second coating solution is the adhesive composition for the tire cord,

The curing of the second step is carried out at 200 to 260 ° C.

A method of manufacturing a rubber reinforcement may be provided.

In this specification, base substrate for rubber reinforcement;

a first coating layer disposed on the base substrate; and

Including; a second coating layer disposed on the first coating layer;

The first coating layer includes a cured product of an epoxy compound and an isocyanate compound,

The second coating layer is an epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; amine compounds; and water, and after preheating and drying at a temperature of 200 to 260 ° C., a rubber reinforcing material comprising a cured product of an adhesive composition having a viscosity in the range of 2.85 to 3.25 measured at room temperature using an Ubbelode viscometer. may be provided.

Hereinafter, an adhesive composition for a tire cord, a tire cord, and a tire according to specific embodiments of the present invention will be described in more detail.

According to one embodiment of the invention, an epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; amine compounds; and water, and the relative viscosity measured at room temperature after drying using a Ubbelode viscometer after drying satisfies the range of 2.85 to 3.25, an adhesive composition for a tire cord may be provided.

The viscosity may be obtained by drying the adhesive composition at a temperature preheated to 200 to 260° C., maintaining it in a thermostat for 30 seconds to 30 minutes, and then measuring it at room temperature using an Ubelode viscometer.

The present inventors intend to provide a rubber reinforcing material using an adhesive composition (ie, RF-free adhesive composition) that does not contain rubber (or latex) containing resorcinol-formaldehyde or a component derived therefrom. , By setting the heat treatment drying temperature of the adhesive composition to a specific range when manufacturing a rubber reinforcing material using the adhesive composition, it was confirmed that the adhesive composition has high adhesion with tire rubber and heat-resistant adhesion, and the invention was completed.

Therefore, in the present invention, after the adhesive composition is prepared, drying conditions are specified and applied to the rubber reinforcing material.

Therefore, according to another embodiment of the present invention, a first step of immersing in a first coating solution containing an epoxy compound and an isocyanate compound, drying and curing to form a first coating layer on the base substrate; and a second step of immersing the base substrate having the first coating layer in a second coating solution, drying and curing to form a second coating layer on the first coating layer, wherein the second coating solution is an epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; chain extenders; and water, wherein the curing of the second step is performed at 200 to 260° C., and a method for manufacturing a rubber reinforcing material may be provided. Curing of the first step may be performed at 200 to 260°C.

First, in the specification of the present invention, the viscosity may mean a relative viscosity measured using a Ubbelode viscometer after drying at a high temperature of 200 to 260° C. with respect to the adhesive composition.

Specifically, the adhesive composition for a tire cord of the present invention is an RF-free adhesive composition, comprising: an epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; amine compounds; and water. When this RF-free adhesive composition is prepared and applied to a rubber reinforcing material, since an epoxy resin and an isocyanate compound are included, the adhesiveness can be improved by adjusting the heat treatment conditions.

In particular, the viscosity of the existing RF-free immersion (Dip) adhesive solution is 2.50 to 2.85, and the present invention is characterized in that the appropriate viscosity is adjusted to 2.85 to 3.25 after high temperature treatment at a certain temperature for this adhesive composition. Therefore, the present invention can greatly improve the adhesiveness compared to the prior art.

Accordingly, in the present invention, the rubber reinforcement may be provided using the adhesive solution having the viscosity adjusted, and in this case, two types of RF-free adhesive compositions of the first coating solution and the second coating solution may be used.

In one example, in the present invention, an adhesive composition in which an epoxy resin and an isocyanate compound are used may be used as the first coating solution.

Moreover, the said epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; amine compounds; And a composition having a viscosity of 2.50 to 2.85 including water may be used as the second coating solution.

Here, the viscosity range of the second coating solution may be obtained by drying at a temperature preheated to 200 to 260° C., maintaining it in a thermostat for 30 seconds to 3 minutes, and then measuring it at room temperature using an Ubbelode viscometer. That is, the viscosity was measured after preheating and drying the second coating solution, which is the adhesive composition for tire cords, under the high temperature conditions, and then leaving it to stand in a constant temperature water bath.

More specifically, the present invention is characterized in that after preparing the first and second coating solutions, when the base substrate for rubber reinforcement is immersed, the heat treatment temperature is set in the range of 200 to 260 °C. In this case, the heat treatment of the first and second coating solutions may include a drying step and a curing step.

The heat treatment may be performed through a drying apparatus including 1) a dry zone, and 2) a heating for curing and a hot zone & normal zone.

의 온도에서 30~150초 동안 진행될 수 있다. At this time, 1) the temperature of the dry zone is 100 to 160

It can be carried out for 30 to 150 seconds at a temperature of

In addition, the heat treatment temperature referred to in the present invention may include a curing step proceeding in the region 2).

When the curing temperature in the region 2) is less than 200°C: Reaction activation of isocyanate, which causes crosslinking reaction, does not occur or reacts only partially, resulting in a decrease in adhesion strength and a decrease in fairness due to unreacted materials (eg, gel generation) .

In addition, when the curing temperature in the region 2) is more than 260° C., decomposition of the material may occur, and in a too hard state, the stiffness increases and there is a possibility of a strong decrease.

Meanwhile, the adhesive composition for tire cords may have a viscosity in the range of 2.50 to 2.85 measured at room temperature using a Ubelode viscometer before drying. In addition, the measured viscosity may mean a relative viscosity as described above.

In addition, the adhesive composition for a tire cord may have a viscosity in the range of 2.85 to 3.25, measured at room temperature using a Ubelode viscometer after drying at a high temperature of 200 to 260°C. When the relative viscosity is 2.85 or less, there is a problem in that the low molecular weight polymers formed during the preparation and curing of the composition are transferred to the adherend and the adhesive strength decreases, and accordingly, sufficient physical properties (eg, mechanical strength, etc.) for the purpose are not provided. can't In addition, when the relative viscosity is low, since the flowability is relatively large, it may not be possible to form a sufficient coating layer on the adherend. If it exceeds 3.25, as the cohesive force between the high molecular weight polymer formed during the composition preparation and curing process increases, it becomes difficult to uniformly distribute (or apply) the adhesive on the adherend, so there is a problem in that the adhesive force decreases. Accordingly, sufficient physical properties (eg, mechanical strength, etc.) for the intended use may not be provided.

The "room temperature" may mean a temperature in the range of, for example, 15 to 30 ℃ in a state in which temperature reduction or heating is not particularly performed. Specifically, within the above temperature range, the room temperature may be a temperature of 17 °C or higher, 19 °C or higher, 21 °C or higher, or 23 °C or higher, and may be a temperature of 29 °C or lower or 27 °C or lower.

In addition, in the present specification, unless otherwise defined, the temperature at which the evaluation of the digitized characteristic is performed may be room temperature.

The "relative viscosity" refers to the ratio of the viscosity of the composition to the solvent viscosity, and when the relative viscosity is measured, demineralized water may be used as the solvent. Specifically, the relative viscosity (RV) is the time taken until the composition passes through a predetermined scale section of the Ubbelode viscometer (T ₁ ), and the time taken until the demineralized water passes through the scale section of the same size (T After measuring ₀ ), it can be calculated by dividing _{T 1} by T _{0 .} In more detail, it will be described in Experimental Example 1 below with reference to FIG. 1 .

Specifically, the lower limit of the viscosity of the composition is, for example, 2.51 or more, 2.52 or more, 2.53 or more, 2.54 or more, 2.55 or more, 2.56 or more, 2.57 or more, 2.58 or more, 2.59 or more, 2.60 or more, 2.61 or more, 2.62 or more, 2.63 or more. , 2.64 or more, 2.65 or more, 2.66 or more, 2.67 or more, 2.68 or more, 2.69 or more, or 2.70 or more.

And, the upper limit of the viscosity of the viscosity composition is, for example, 2.84 or less, 2.83 or less, 2.82 or less, 2.81 or less, 2.80 or less, 2.79 or less, 2.78 or less, 2.77 or less, 2.76 or less, 2.75 or less, 2.74 or less, 2.73 or less, It may be less than or equal to 2.72 or less than or equal to 2.71.

When the adhesive composition for a tire cord satisfies the viscosity range as described above, as shown in the following experimental example, an appropriate level of pickup rate can be secured, processability and productivity can be improved, and excellent adhesion can be provided. have.

In particular, in consideration of the risk of fire or harm to the human body, and securing the dispersibility of other components of the composition, water (H ₂ O) ), it was confirmed that there is a problem in that the viscosity of the adhesive composition is lowered and sufficient adhesive force cannot be secured.

On the other hand, in the adhesive composition of the present invention, the first coating solution may include an epoxy compound and an isocyanate compound. In addition, the second coating solution is an epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; chain extenders; And it may be an adhesive composition for a tire cord comprising water. The composition of each component used in this composition is as follows.

The epoxy compound functions as a kind of curing agent, forms a three-dimensional network structure during heat treatment for the adhesive, and imparts adhesion and layer stability to the coating layer formed from the adhesive composition.

On the premise that the viscosity range of the entire composition described above is satisfied, the type of the epoxy compound included in the adhesive composition is not particularly limited. For example, diethylene glycol-diglycidyl ether, polyethylene glycol-diglycidyl ether, polypropylene glycol-diglycidyl ether, neopentyl glycol-diglycidyl ether, 1,6-hexanediol- Diglycidyl ether, glycerol-polyglycidyl ether, trimethylolpropane-polyglycidyl ether, polyglycerol-polyglycidyl ether, pentaerythol-polyglycidyl ether, diglycerol-polyglycidyl ether glycidyl ether-based compounds such as dil ether and sorbitol-polyglycidyl ether; novolac-type epoxy resins such as phenol novolac-type epoxy resins and cresol novolak-type epoxy resins; and a bisphenol type epoxy resin such as a bisphenol A type epoxy resin or a bisphenol F type epoxy resin.

In addition, on the premise that the viscosity range of the entire composition described above is satisfied, the adhesive composition may use a known or commercially available epoxy compound. For example, as the epoxy compound, EX614B of NAGASE, KETL6000 of Kolon, CL16 of Ipox chemical, or GE500 of Raschig may be used.

The equivalent (Epoxy Equivalent Weight, g/EQ) of the commercially available sorbitol polyglycidyl ether epoxy resin presented above may have a range of 120 to 600 g/eq, and when the equivalent of sorbitol polyglycidyl ether is less than 120, the epoxy resin Since the polymerization unit is small, it may be difficult to form a network structure between isocyanates. In addition, when it exceeds 600, the number of epoxies per unit molecule is relatively insufficient, so that the adhesive force may decrease.

The epoxy compound may be included in an amount of 0.5 to 10% by weight based on the total weight of the adhesive composition. If the content of the epoxy compound is less than 0.5% by weight, the reactivity and crosslinking degree of the adhesive composition may be reduced. On the other hand, when the content of the epoxy compound exceeds 10% by weight, the degree of curing of the adhesive composition increases due to excessive reactivity, so that the adhesive strength of the adhesive layer (or coating layer) formed by the adhesive composition may be reduced.

Meanwhile, in order to impart adhesive strength and cohesion strength, the adhesive composition for a tire cord may include an isocyanate-based compound as a crosslinking agent.

In the second coating solution, when the isocyanate compound is based on the total composition, according to an embodiment, the isocyanate compound may be included in an amount of 1 to 20% by weight based on the total weight of the adhesive composition for a tire cord.

The isocyanate compound forms a three-dimensional network structure during heat treatment of the adhesive to impart adhesion and layer stability to the coating layer formed from the adhesive composition.

The type of the isocyanate compound is not particularly limited, but may be selected in consideration of the viscosity range of the entire composition described above. For example, as the isocyanate, a compound containing an aromatic group, that is, an aromatic isocyanate may be used. In the case of the aromatic polyisocyanate, it may be advantageous to increase the low viscosity of the aqueous composition since a high reaction rate can be secured as compared with the non-aromatic polyisocyanate.

In one example, the isocyanate compound may have a blocked terminal (Blocked isocyanate). The blocked isocyanate compound can be prepared, for example, by a reaction of adding a known blocking agent to the polyisocyanate compound. Such blocking agents include, for example, phenol, thiophenol, chlorophenol, cresol, resorcinol, p-sec-butylphenol, ptert-butylphenol, p-sec-amylphenol, p-octylphenol, p-nonyl. phenols such as phenol; secondary or tertiary alcohols such as isopropyl alcohol and tert-butyl alcohol; aromatic 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; A basic nitrogen compound, such as 3-hydroxypyridine, acidic sodium sulfite, etc. can be used.

More specifically, commercially available water-dispersion blocking isocyanate products such as EMS's IL-6 and MEISEI Chemical's DM-6500 may be used as the isocyanate compound.

In addition, a known or commercially available isocyanate compound may be used as the adhesive composition on the premise that the viscosity range of the entire composition described above is satisfied. For example, commercially available water-dispersion blocking isocyanate products such as EMS's IL-6 or MEISEI Chemical's DM-6500 may be used.

In the second coating solution, the latex included in the adhesive composition for a tire cord is a component used in consideration of the use of the composition.

Specifically, the adhesive composition may be used for an adherend such as a rubber composite, a rubber structure, or a rubber reinforcing material. When latex is used, it may be advantageous to secure affinity, miscibility, or adhesion with the adherend. In some cases, the latex component included in the adhesive composition may be selected to be the same as the rubber component of the adherend.

In one example, the latex may not contain resorcinol-formaldehyde or a component derived therefrom. That is, the composition may be an RF-free composition. Accordingly, compared to the prior art using RF latex, an environmentally friendly adhesive composition that is not harmful to the human body can be provided. In addition, the use of such adhesive compositions provides the advantage of reducing after-care and post-treatment costs.

The type of latex that can be used in the composition is not particularly limited, as long as it does not contain resorcinol-formaldehyde or a component derived therefrom, and does not go against the present application, such as being able to satisfy the viscosity of the entire composition described above.

In one example, as the latex, natural rubber latex, vinyl-pyridine-styrene-butadiene-based copolymer latex (Vinyl-Pyridine-Styrene-Butadiene-copolymer Latex) (VP latex), styrene-butadiene-based copolymer latex, acrylic acid Ester-based copolymer latex, butyl rubber latex, chloroprene rubber latex, or modified latex thereof may be used. With respect to the modified latex, a specific kind of latex or a method of modifying the latex is not limited. For example, a modified latex obtained by modifying a vinyl-pyridine-styrene-butadiene-based copolymer with a carboxyl group or the like may be used.

Commercially available latex may also be used if the viscosity of the overall composition described below can be satisfied. For example, as VP latex, commercially available products such as Denaka's LM-60, APCOTEX's VP-150, Nippon A&L's VB-1099, or Closlen's 5218 or 0653 may be used.

In one example, a latex component comprising at least one of the latexes described above may be used in the adhesive composition.

In one example, based on the total composition, according to an embodiment, the latex may be included in an amount of 1.0 to 30.0% by weight based on the total weight of the adhesive composition for a tire cord. When the above range is satisfied, it may be advantageous in securing affinity, miscibility, or adhesion to a rubber-containing adherend in which the adhesive composition for a tire cord is used.

In one example, the latex is dispersed in a solvent (water or organic solvent), and may be mixed with other composition components.

On the other hand, the water-dispersed polyurethane may be a well-known water-dispersed polyurethane dispersed in _{water (H 2 O).} The content of water contained in the water-dispersed polyurethane is not particularly limited. For example, the content of water in the water-dispersed polyurethane may be in the range of 40 wt% to 80 wt%, and the other content may be occupied by the polyurethane. In some cases, the water-dispersible polyurethane may contain a known trace amount of additives in a small amount of about 10% by weight or less, about 5% by weight or less, or about 1% by weight or less.

According to an embodiment of the present invention, there is no particular limitation on the type of water-dispersible polyurethane, and water-dispersible polyurethane prepared by various methods may be used.

For example, a water-dispersed polyurethane may be prepared by reacting a polyol containing a polycarbonate polyol as a main component, an aliphatic polyisocyanate, and a hydrophilic diol.

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 350,000 g/mol.

More specifically, Bayer Material Science's Impranil DL 1537, Dow Chemical's ROBOND, etc. may be used as the water-dispersible polyurethane according to an embodiment of the present invention.

Meanwhile, when the adhesive composition for tire cords is based on the total composition, the water-dispersible polyurethane may be included in an amount of 0.5 to 10.0% by weight based on the total weight of the adhesive composition for tire cords.

When the adhesive composition for a tire cord contains a water-dispersed polyurethane in a lower content than the epoxy compound, adhesive performance and fatigue performance may decrease and the performance of the adhesive solution may appear insignificant. When the adhesive composition for tire cord contains an excessive amount of water-dispersible polyurethane resin compared to the epoxy compound, sludge is likely to occur due to high concentration, and due to the high reactivity of the aromatic polyurethane resin, gel (Gel) in the process step This may cause product appearance defects.

The amine compound contained in the adhesive composition for a tire cord functions as a curing agent. A stable coating layer may be formed by curing or promoting curing by the amine compound.

In the adhesive composition for a tire cord, one or more amine compounds may be used in consideration of a decrease in viscosity due to the use of water-dispersible polyurethane and solvent (water). Specifically, the adhesive composition may include at least an amine compound having a chain structure.

In one example, the amine compound having the chain structure may be a compound derived from a reaction between ethylene diamine and stearic acid. In this case, the amine compound may have 8 to 20 carbon atoms. (Product name used: Lonza Acrawax C Dipersion) The amine compound may exist in a solid or liquid state, and when it exists as a solid, a solvent for dispersing it into a liquid may be used.

In addition, the type of the amine compound is not particularly limited, and any amine compound that can be used as a curing agent may be used as the amine compound according to an embodiment of the present invention without limitation. As the amine compound, for example, at least one of an aliphatic amine, an alicyclic amine and an aromatic amine may be used.

More specifically, DAEJUNG's Piperazine, Kukdo Chemical's G640, Huntsman's HK511, etc. may be used as the chain extender according to an embodiment of the present invention. In another example, as a preferred example, N,N'-Ethylenebis(stearamide), which is a reaction product of ethylenediamine and stearic acid, may be used.

In addition, the adhesive composition of the present invention may include a compound in which at least one amine compound has a chain structure, and a compound having a chain structure such as piperazine, which may further function as a chain extender It may be desirable to include them together.

In addition, in consideration of accelerating curing of the adhesive composition for a tire cord, a weight ratio between the amine compound having the chain structure and the amine compound having an alicyclic structure may be 1:1 to 3:1 or 7:1.

The adhesive composition for a tire cord may include 0.1 to 1 part by weight of a chain extender based on 1 part by weight of the epoxy compound. In addition, based on the total composition, according to one embodiment, the amine compound may be included in an amount of 0.1 to 10% by weight or 0.1 to 3.0% by weight based on the total weight of the adhesive composition for a tire cord.

The adhesive composition for a tire cord may include water (H ₂ O).

Specifically, in the adhesive composition for a tire cord, water is used as a solvent instead of an organic solvent (eg, toluene or ethanol, etc.) in consideration of the harmfulness to the human body and the risk of flammability. That is, the adhesive composition for a tire cord can be regarded as a water-based or water-based composition.

In one example, water used as a solvent in the adhesive composition may be demineralized water (or pure water, demineralized water).

In one example, based on the total weight of the composition whose viscosity is measured, the water content may be 60% by weight or more. Specifically, the lower limit of the content of water may be, for example, 65% by weight or more, 70% by weight or more, 75% by weight or more, or 80% by weight or more. And, the upper limit of the water content may be, for example, 85% by weight or less, 80% by weight or less, or 75% by weight or less. When the above range is satisfied, each component forming the composition may be sufficiently dispersed in the solvent.

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 includes not only the content of water mixed as a solvent, but also the content of water mixed with other components as used to disperse the water-dispersed water-dispersed polyurethane. can

Preferably, the adhesive composition according to an embodiment of the present invention may be included in the remaining amount based on the total weight, for example, it contains 65 to 85% by weight of the solvent. Other components (hereinafter, also referred to as "solid content") are mixed and stirred by a solvent to form an adhesive composition.

Accordingly, the adhesive composition according to an embodiment of the present invention includes 15 to 40% by weight of solid content (components other than the solvent) based on the total weight.

Hereinafter, a method of manufacturing a rubber reinforcing material according to another embodiment of the present invention will be described in more detail.

A method for manufacturing a rubber reinforcement material according to another embodiment of the present invention includes a primary coating step of immersing a base substrate for a rubber reinforcement in a first coating solution and drying to form a first coating layer on the base substrate, and the primary coated base and a secondary coating step of immersing the substrate in a second coating solution and drying the substrate to form a second coating layer on the first coating layer.

As the base substrate for the rubber reinforcement, for example. There are raw cords for tire cords, films, textile substrates, and the like. By forming the first and second coating layers on the base substrate for rubber reinforcement, a tire cord, a film for rubber reinforcement, a fiber for rubber reinforcement, and the like are made.

Here, the coating layer formed by the primary coating is referred to as a first coating layer, and the coating layer formed by the secondary coating is referred to as a second coating layer. The second coating layer is formed on the first coating layer. The first coating layer and the second coating layer are collectively referred to as a coating layer.

According to the present invention, a first coating solution comprising an epoxy compound and an isocyanate compound is used to impart a reactive group to the polyester.

The first coating solution may penetrate into the monofilament of polyester, which is the base substrate for reinforcing rubber, to impart a reactive group to the base substrate.

When the amount of the isocyanate compound is small compared to the epoxy compound, sufficient crosslinking is not achieved, and in many cases, the degree of curing of the first coating layer is increased more than necessary. Accordingly, according to another embodiment of the present invention, the epoxy compound and the isocyanate compound in the first coating solution have a weight ratio of 2:1 to 1:2.

The epoxy compound and the isocyanate compound are dispersed in the solvent. That is, the first coating solution includes an epoxy compound, an isocyanate compound, and a solvent. According to another embodiment of the present invention, water may be used as the solvent.

When the solvent is insufficient, the primary coating by immersion is not performed smoothly, and when the content of the solvent is excessively large, the reactive group is not sufficiently provided to the base substrate for reinforcing rubber. Considering these points, the solvent has a content of 94 to 99% by weight, and the mixture of the epoxy compound and the isocyanate compound has a content of 1 to 6% by weight based on the total weight of the first coating solution. That is, the first coating solution includes 1 to 6% by weight of a mixture consisting of an epoxy compound and an isocyanate compound and 94 to 99% by weight of a solvent based on the total weight.

The base substrate for rubber reinforcement is immersed in the first coating solution and then dried. The first coating solution is disposed on the base substrate for rubber reinforcement by such immersion. The first coating solution is then dried and cured.

In the first coating step of the base substrate, the drying is performed at a temperature of 100 to 160° C. for 30 to 150 seconds. Accordingly, the first coating layer is formed on the base substrate for the rubber reinforcement.

The manufacturing method of the rubber reinforcing material further includes curing the first coating layer at a temperature of 200 to 260° C. for 30 to 150 seconds after the drying. Accordingly, the first coating layer is formed on the base substrate for the rubber reinforcement.

The first coating layer is stably formed on the base substrate for rubber reinforcement by such heat treatment.

The method of forming the first coating layer according to another embodiment of the present invention is not limited to the immersion method. After the first coating solution is applied or sprayed on the base substrate for rubber reinforcement, the first coating layer may be formed by drying and curing.

Next, a second coating layer is formed on the first coating layer. This is called secondary coating.

The second coating layer is made by the second coating solution. The adhesive composition according to an embodiment of the present invention may be used as the second coating solution.

Specifically, the second coating solution may include an epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; chain extenders; And it may be an adhesive composition for a tire cord comprising water.

The adhesive composition used as the second coating solution is as described below.

The second coating layer forming step is a step of forming a second coating layer having excellent adhesion to rubber on a base substrate for a rubber reinforcing material to which a reactive active group is imparted, and may be formed in the same or similar manner to forming the first coating layer.

Specifically, the primary coated base substrate for rubber reinforcement is immersed in the second coating solution and then dried. The second coating solution is disposed on the first coating layer by immersion. However, another embodiment of the present invention is not limited thereto, and the second coating solution may be applied or sprayed on the first coating layer, and the second coating solution may be disposed on the first coating layer.

In the secondary coating step of the base substrate, the drying is performed at a temperature of 100 to 160° C. for 30 to 150 seconds.

The manufacturing method of the rubber reinforcement further includes curing the second coating layer at a temperature of 200 to 260° C. for 30 to 150 seconds after the drying.

Accordingly, the second coating layer is formed on the base substrate for the rubber reinforcement.

The second coating layer is stably formed on the first coating layer by this heat treatment. As a result, a rubber reinforcement having a coating layer is produced. Here, the coating layer includes a first coating layer and a second coating layer.

Hereinafter, a method of manufacturing the tire cord 201, which is a representative rubber reinforcing material, will be described with reference to FIGS. 2 and 3 . 2 is a schematic diagram of a manufacturing process of the tire cord 201, and FIG. 3 is a cross-sectional view of the tire cord 201 manufactured according to the manufacturing process of FIG.

The tire cord 201 may be referred to as a representative rubber reinforcing material. Also, a “raw cord” 110 is used as a base material for a rubber reinforcing material for manufacturing the tire cord 201 . That is, the tire cord 201 shown in FIGS. 2 and 3 is a rubber reinforcing material, and the raw cord 110 is a base material for the rubber reinforcing material.

With the raw cord 110, for example, using a polyester yarn, two lower twisted yarns 111 and 112 having a twist number of 300 to 450 TPM are staged with a twist number of 300 to 460 TPM. can be used. The raw cord 110 may be manufactured and distributed while being wound around the first winder 12 .

The raw cord 110 is immersed in the first coating solution 21 , dried and first coated, so that the first coating layer 211 is formed on the raw cord 110 .

The first coating solution 21 is contained in the first coating tank 20 . The immersion process is performed by passing the raw code 110 through the first coating solution 21 contained in the first coating tank 20 .

The dipping process may be performed in a dipping machine in which tension, dipping time and temperature can be controlled. This immersion device includes a first coating tank 20 containing the first coating solution (21).

In addition to the immersion process, the first coating solution 21 may be applied to the raw cord 110 by coating using a blade or a coater or spraying using a sprayer.

The first coating solution 21 includes an epoxy compound and an isocyanate compound.

The content ratio of the epoxy compound and the isocyanate compound in the first coating solution is adjusted to a weight ratio of 2:1 to 1:2. In addition, the first coating solution includes 1 to 6% by weight of a mixture consisting of an epoxy compound and an isocyanate compound and 94 to 99% by weight of a solvent. Water (pure water, demineralized water) is used as a solvent.

The first coating solution 21 penetrates even into the monofilaments constituting the lower twisted yarns 111 and 112 of the raw cord 110 to impart a reactive group to the lock rod 110 .

Next, the first coating liquid 21 applied to the raw cord 110 is dried and cured.

Drying may be performed in the drying device 30 . For drying, the raw cord 110 treated with the first coating solution 21 is first heat-treated at a temperature of 100 to 160° C. for 30 to 150 seconds in a drying area. Thereafter, secondary heat treatment is performed at 200 to 260° C. as in the above-described range in the heating and normal region. Accordingly, the first coating layer 211 is formed on the raw cord 110 . At this time, a tension in the range of 0.05 to 3.00 g/d may be applied to the raw cord 110 .

Next, the first coating layer 211 may be cured by being treated at a temperature of 200 to 260° C. for 30 to 150 seconds. Curing may also be performed in the first drying device 30 .

Next, a second coating layer 212 is formed on the first coating layer 211 .

The second coating layer forming step is a step of applying a rubber-based adhesive composition to the raw cord 110 to which the active group is imparted, and a second coating solution having a composition different from that of the first coating solution is used, and a dipping process is performed like the first coating solution. can be applied.

To form the second coating layer 212 , the raw cord 110 coated with the first coating layer 211 is immersed in the second coating solution 41 . The second coating solution 41 is contained in the second coating tank 40 .

The second coating solution 41 is applied on the first coating layer 211 by such immersion.

Next, the second coating solution 41 applied on the first coating layer 211 is dried and cured.

Drying may be performed in the drying apparatus 50 . For drying, it is first heat-treated for 30-150 seconds at a temperature of 100-160° C. in a drying area. Thereafter, secondary heat treatment is performed at 200 to 260° C. as in the above-described range in the heating and normal region. Accordingly, the second coating layer 212 is formed on the first coating layer 211 . At this time, a tension in the range of 0.05 to 3.00 g/d may be applied to the raw cord 110 . However, another embodiment of the present invention is not limited thereto, and tension may not be applied to the raw cord 110 in the drying step.

Next, the second coating layer 212 is cured by heat treatment at a temperature of 200 to 260° C. for 30 to 150 seconds. Curing may be performed in the second drying device 50 . The tire cord 201 manufactured in this way is wound around the second winder 13 .

On the other hand, in the primary coating and the secondary coating, the range of process conditions such as temperature, time, and tension is the same or similar, but considering the characteristics and physical properties of the coating solution, the process conditions of the secondary coating are the process of the primary coating. conditions may be different.

Referring to FIG. 2 , since the tire cord 201 is made by a dipping process, the tire cord 201 is also referred to as a dip cord.

According to this method, more environmentally friendly than the conventional manufacturing method, and various rubber reinforcement materials having excellent initial adhesion and internal adhesion can be manufactured. In addition, the manufacturing method according to an embodiment of the present invention may be applied to the manufacture of other rubber reinforcement materials using fibers and films in addition to the tire cord.

Specifically, another embodiment of the present invention provides a base substrate 110 for rubber reinforcement, a first coating layer 211 disposed on the base substrate 110 , and a second coating layer disposed on the first coating layer 211 . 212, wherein the first coating layer 211 includes a cured product of an epoxy compound and an isocyanate compound, and the second coating layer contains an epoxy compound, an isocyanate compound, rubber latex, polyurethane, an amine compound, and water, Provided is a rubber reinforcing material including a cured product of an adhesive composition for a tire cord that satisfies a viscosity range after drying under one condition.

That is, the base substrate for rubber reinforcement; a first coating layer disposed on the base substrate; and a second coating layer disposed on the first coating layer, wherein the first coating layer includes a cured product of an epoxy compound and an isocyanate compound, and the second coating layer includes an epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; amine compounds; and water, and after preheating and drying at 200 to 260° C., a cured product of an adhesive composition having a viscosity in the range of 2.85 to 3.25 measured at room temperature using an Ubbelode viscometer. can At this time, when measuring the viscosity, the adhesive composition is dried at a temperature preheated to 200 to 260° C. and maintained in a constant temperature bath for 30 seconds to 30 minutes, and then measured at room temperature using an Ubelode viscometer.

Here, the base substrate 110 is, for example, raw cord. Also, the rubber reinforcement is the tire cord 201 . Here, the first coating layer and the second coating layer may have a visible boundary. Also, polyurethane is derived from water-dispersible polyurethane (PUD).

Meanwhile, according to another embodiment of the present invention, a tire cord including the rubber reinforcing material may be provided.

Specific details regarding the adhesive composition for a tire cord according to the embodiment include the above.

The adhesive composition for a tire cord does not contain resorcinol-formaldehyde or a component derived therefrom, so it is not only eco-friendly, but also can greatly improve the adhesion and heat resistance adhesion between the tire rubber and the tire cord, and thus the tire rubber and high It is possible to improve tire durability by having adhesive strength and heat-resistant adhesion. In addition, the present invention may provide a tire including the tire cord.

The specific use of the tire cord is not particularly limited, but as the adhesive layer is included, higher adhesion to the hybrid cord may be realized, and it may be suitably used for a large tire requiring higher heat-resistance adhesion.

Meanwhile, according to another embodiment of the present invention, a tire including a tire cord may be provided.

The pneumatic 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 part, the shoulder part, the sidewall part, and the bead part; a cord positioned 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, by setting an appropriate temperature range for dry heat treatment when manufacturing a rubber reinforcing material by applying the adhesive composition for RF-free tire cords, the activation of the reaction between the epoxy resin and the isocyanate compound included in the adhesive composition can be optimized. Accordingly, it is possible to provide a rubber reinforcing material having excellent adhesion by preventing a decrease in adhesion and fairness due to unreacted materials during manufacturing of the rubber reinforcing material. In addition, the present invention can contribute to improving the strength of the tire cord by suppressing the possibility of material decomposition.

Accordingly, in the present invention, a tire cord capable of improving tire durability by having high adhesive strength and heat-resistant adhesion to tire rubber, and a tire including the tire cord can be provided.

1 schematically shows a Ubelode viscometer in order to explain a method for measuring the viscosity of the adhesive composition of the present invention.
2 is a schematic diagram of a manufacturing process of a tire cord.
3 is a cross-sectional view of tire cords manufactured according to Examples and Comparative Examples.

The invention is described in more detail in the following examples. However, the following examples are merely illustrative of the present invention, and the specific contents of the present invention are not limited by the following examples.

[Examples and Comparative Examples: Preparation of Adhesive Composition for Tire Cord and Tire Cord]

(1) Preparation of adhesive composition for tire cord

Each composition of Examples and Comparative Examples was prepared by mixing each component under the conditions shown in Tables 1 and 2 below, and stirring for 24 hours. (TSC: Total Solid Content, total solid content)

(Unit: % by weight) Example One 2 3 4 5 6 (A) Latex 14.7 13.7 12.7 14.7 14.7 14.7 (B) Water-dispersible polyurethane 1.8 1.8 1.8 1.8 1.3 1.8 (C) amine compounds 1.8 1.8 1.8 1.8 1.8 1.8 (E) epoxy resin 1.2 1.2 1.2 1.2 1.2 1.2 (F) isocyanate 3.7 3.7 3.7 3.7 3.7 5.7 (G) chain extenders 0.4 0.4 0.4 0.4 0.4 0.4 (D) solvent 76.4 77.4 78.4 76.4 76.9 74.4 TSC 23.6 22.6 21.6 23.6 23.1 25.6

(Unit: % by weight) comparative example One 2 3 4 5 (A) Latex 0 14.7 14.7 14.7 14.7 (B) Water-dispersible polyurethane 1.8 1.8 0 1.8 1.8 (C) amine compounds 1.8 1.8 1.8 1.8 1.8 (E) epoxy resin 1.2 1.2 1.2 1.2 1.2 (F) isocyanate 3.7 0 3.7 3.7 3.7 (G) chain extenders 0.4 0.4 0.4 0.4 0.4 (D) solvent 91.1 80.1 78.2 76.4 76.4 TSC 8.9 19.9 21.8 23.6 23.6

main)

(A) Latex: Closlen's 0653 VP Latex

(B) Water-dispersed polyurethane: 308,000 g/mol of weight average molecular weight (Mw) (Impranil DL 1537 from Bayer Material Science)"

(C) Amine compound: N,N'-Ethylenebis(stearamide), a reaction product of ethylenediamine and stearic acid

(D) solvent: distilled water (Demineralized water)

(E) Epoxy resin: EX614B of NAGASE (Sorbitol Polyglycidyl Ether, Epoxy content: 167 g/eq, Viscosity (mPas): 21,200)

(F) Isocyanate: IL-6 from EMS

(G) Chain extender: Piperazine

(2) Preparation of adhesive composition for tire cord

100 ml of each of the adhesive compositions prepared above was transferred to a round flask, and then a heating mantle was installed.

Thereafter, the heating mantle and the round flask were preheated at the same time under the HoT&Nor setting conditions of Tables 3 and 4, and then dried.

Then, after stirring at 300 rpm for 80 seconds according to each condition, each composition was transferred to a Uvelod viscometer, and left in a constant temperature water bath at 25° C. for 30 minutes to minimize additional reaction.

(3) Manufacture of tire cords

According to the process diagram of FIG. 2 , a tire cord was manufactured.

3 is a cross-sectional view showing tire cords manufactured in Examples and Comparative Examples.

After preparing two strands 111 and 112 of lower twisted yarn (Z-direction) having a twist number of 360 TPM using a polyester yarn, the lower twisted yarns 111 and 112 of the two strands are staged together with a twist number of 360 TPM. (S-direction) to prepare a ply-twisted yarn (1650 dtex/2 ply). The ply-twisted yarn thus prepared was used as the raw cord 110 .

After immersing the raw cord 110 made of polyester in the first coating solution, drying and curing under the conditions of Tables 5 to 8 to form the first coating layer 211, the raw cord 110 A reaction active group was imparted. The first coating solution was mixed with 97% by weight of demineralized water as a solvent and 1.0% by weight of a sorbitol-type epoxy compound (EX614B manufactured by NAGASE), stirred for about 1 hour, and then an isocyanate compound (EMS) of IL-6 product) was prepared by further mixing 2.0% by weight.

Next, in order to apply the adhesive composition to the raw cord 110 on which the first coating layer 211 is formed, the raw cord 110 on which the first coating layer 211 is formed is mixed with a second coating solution (adhesive compositions of each Example and Comparative Example). ), followed by drying and curing for about 1 minute, respectively, under the conditions of Tables 5 to 8. The first coating liquid immersion process and the second coating liquid immersion process were performed continuously, and the tension condition at this time was 0.5 g/d. Accordingly, tire cords 201 according to Examples and Comparative Examples were manufactured in the form of a dipped cord.

Example One 2 3 4 5 6 Dry temperature
(℃) 150 150 150 150 150 150 Hot&Nor
Temperature
(℃) 240 240 240 260 240 240

comparative example One 2 3 4 5 Dry
Temperature
(℃) 150 150 150 150 150 Hot&Nor
Temperature
(℃) 240 240 240 195 265

[Experimental example]

Experimental Example 1: Measurement of Viscosity of Examples and Comparative Examples

After drying the compositions of Examples and Comparative Examples at a high temperature of 240 ° C., at room temperature (about 25 ° C.) using a Ubbelohde viscometer, the viscosity of each composition of Examples and Comparative Examples prepared as above was measured. That is, after the composition was dried at high temperature, it was measured using an Ubbelohde viscometer after being left in a constant temperature water bath (about 25 ° C. for 30 minutes. Specifically, the demineralized water was subjected to the following procedure with an Ubbelohde viscometer. After adding a certain amount to the , the viscosity characteristics of the demineralized water were measured, and the viscosity characteristics of the composition were measured in the same way, and then the relative viscosity was calculated based on the previously measured viscosity characteristics of the demineralized water.

Referring to FIG. 1, the specific viscosity measurement method is as follows, and the measurement results are shown in Tables 5 and 6.

(1) Inject the sample (composition or demineralized water) into tube A of the Ubelode viscometer.

(2) After setting the constant temperature water bath to 25℃, fix part C so that it is submerged in the water bath and leave it for 30 minutes.

(3) Using a pipette filler, let the sample come to the middle of part C.

(4) After that, let the sample flow down and measure the time it takes for the liquid level of the sample to pass through the upper scale of B and pass the lower scale of B.

(5) Calculate the relative viscosity by applying the measured time to the formula for calculating the relative viscosity below.

<Relative viscosity calculation formula>

T1/T0

T1: time taken for the composition to pass through the upper scale of B and pass through the lower scale of B, T0: demineralized water

Example One 2 3 4 5 6 Viscosity (RV) 2.91 2.89 2.87 2.94 2.88 2.9

comparative example One One 3 4 5 Viscosity (RV) 1.45 1.82 2.63 2.54 3.82

From the above results, the Examples satisfy a certain component composition and a solid content range, and after drying at a high temperature, the viscosity measured at room temperature using an Ubbelode viscometer satisfies the range of 2.85 to 3.25, so that the flowability of each component is uniformly mixed. It was excellent and was uniformly coated on the surface of the fiber reinforcement to ensure high adhesion.

On the other hand, in Comparative Examples, the viscosity was 2.85 or less or 3.25 or more, and thus the flowability of the adhesive composition was poor.

Experimental Example 2: Adhesion evaluation

Adhesive strength of the adhesive composition was evaluated at an appropriate manufacturing temperature setting. To this end, for the tire cords manufactured in Examples and Comparative Examples, adhesion strength evaluation was performed according to ASTM D4393 in order to evaluate the adhesion strength per unit area, and the results are recorded in Tables 7 and 8 below.

에서 15분 동안 가황하여 샘플을 제작하였다. 그리고, 샘플을 재단하여 1 인치의 폭을 갖는 시편을 제조하였다.Specifically, a 0.6 mm thick rubber sheet, cord paper, 0.6 mm thick rubber sheet, cord paper, and 0.6 mm thick rubber sheet were sequentially laminated, and 170 at a pressure of 60 kg/cm2.

Samples were prepared by vulcanization for 15 minutes. Then, the sample was cut to prepare a specimen having a width of 1 inch.

에서 125 mm/min의 속도로 박리 시험을 하여 카카스층에 대한 타이어 코드의 접착력 측정하고, 측정된 접착력의 상대적 값을 기재하였다. 이때, 박리시 발생하는 하중의 3회 평균값을 접착력으로 산정하였다. 결과는 표 19 내지 27에 기록하였다.For the manufactured specimen, 25 using a universal testing machine (Instron)

In a peel test at a speed of 125 mm/min, the adhesion force of the tire cord to the carcass layer was measured, and the relative value of the measured adhesion force was described. At this time, the average value of three times of the load generated during peeling was calculated as the adhesive force. The results are reported in Tables 19-27.

The measured value is normalized based on the value of the adhesive layer formed by the adhesive composition of Example 1, and is compared with each other.

Example One 2 3 4 5 10 adhesion
(%) 100 98 97 94 98 94

comparative example One 2 3 4 5 adhesion
(%) 76 46 55 42 74

As seen from the above results, the Examples, compared to the comparative example, satisfies a certain component composition and a range of solid content, so that all of the adhesive strength was excellent.

12: first winder, 13: second winder
20: first coating tank, 21: first cotan solution
30: first drying device
40: second coating tank, 41: second coating solution
50: second drying device
110: raw code 111, 112: lower twisted yarn
201: tire code 210: coating layer
211: first coating layer 212: second adhesive layer (or coating layer)

Claims (15)

epoxy compounds; isocyanate compounds; latex; water-dispersible polyurethane; amine compounds; and water;
After drying, the viscosity measured at room temperature using a Ubelode viscometer satisfies the range of 2.85 to 3.25, the adhesive composition for a tire cord.
The method of claim 1, wherein the viscosity is obtained by drying the adhesive composition at a temperature preheated to 200 to 260° C. and maintaining it in a constant temperature bath for 30 seconds to 30 minutes, and then measuring it at room temperature using a Ubelode viscometer. Adhesive composition for tire cords.
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, and polypropylene-based urethane and polyethylene-based urethane. containing,
Adhesive composition for tire cords.
The method of claim 1,
The water-dispersible polyurethane is an adhesive composition for a tire cord comprising 0.5 to 10.0 wt%.
The method of claim 1,
The latex is an adhesive composition for a tire cord, comprising 1.0 to 30.0% by weight.
The method of claim 1,
The amine compound comprises an amine compound having a chain structure, the adhesive composition for a tire cord.
The method of claim 1,
The isocyanate-based compound comprises a blocked isocyanate compound, the adhesive composition for a tire cord.
The method of claim 1,
The adhesive composition for a tire cord has a solid content of 15 to 40% by weight, the adhesive composition for a tire cord.
A first step of immersing the base substrate for rubber reinforcement in a first coating solution containing an epoxy compound and an isocyanate compound, drying and curing to form a first coating layer on the base substrate; and
A second step of immersing the base substrate having the first coating layer in a second coating solution, drying and curing to form a second coating layer on the first coating layer;
The second coating solution is the adhesive composition for the tire cord of claim 1,
The curing of the second step proceeds at 200 to 260 ° C. for 30 seconds to 150 seconds, a method of manufacturing a rubber reinforcement.
10. The method of claim 9,
The curing of the first step is a method of manufacturing a rubber reinforcement that proceeds for 30 seconds to 150 seconds at 200 to 260 ℃.
10. The method of claim 9,
The base substrate is a method of manufacturing a rubber reinforcement comprising polyester.
10. The method of claim 9,
The base substrate is a raw cord (raw cord), a method of manufacturing a rubber reinforcement material of any one of a film and a fiber.
10. The method of claim 9,
The drying of the first step and the second step is carried out for 30 to 150 seconds at a temperature of 100 to 160 ℃, respectively, the manufacturing method of the rubber reinforcement.
base substrate for rubber reinforcement;
a first coating layer disposed on the base substrate; and
Including; a second coating layer disposed on the first coating layer;
The first coating layer includes a cured product of an epoxy compound and an isocyanate compound,
The second coating layer is an epoxy compound; isocyanate compounds; latex; water-dispersible polyurethane; amine compounds; and water, and after preheating and drying at a temperature of 200 to 260° C., a cured product of an adhesive composition having a viscosity in the range of 2.85 to 3.25 measured at room temperature using an Ubbelode viscometer.
15. The method of claim 14,
The base material is a rubber reinforcing material that is a raw cord.

Images