JPS5812387B2 - Manufacturing method of polyester synthetic fiber for rubber reinforcement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing polyester synthetic fibers for rubber reinforcement;
More specifically, the present invention relates to a manufacturing method in which polyester synthetic fibers are treated with an adhesive after a specific treatment agent is applied thereto.

An object of the present invention is to provide a rubber-reinforcing polyester synthetic fiber that reduces the bending stiffness of a cord or fabric treated with an adhesive and has high strength and adhesive strength.

Polyester synthetic fibers have excellent dimensional stability, heat resistance, fatigue resistance, etc., and are used as rubber reinforcing materials for belts, tires, etc.

In general, rubber reinforcing materials are made by first twisting the spun fiber bundle yarns, then collecting two or several yarns and giving them a second twist to create a cord, which is then made into a sudare fabric, which is then treated with an adhesive and embedded in rubber. By performing vulcanization treatment, its reinforcing effect is exhibited.

Therefore, in order to maximize its effectiveness as a rubber reinforcing material, the adhesive-treated sudare fabric (hereinafter referred to as treated sudare) must not only be highly strong, but also have sufficient adhesive strength with the rubber. Must be.

In recent years, in addition to the above-mentioned characteristics, there has been a growing demand for processing slag to be flexible and easy to handle in order to improve productivity.

In order to improve the strength of processed threads, it is necessary not only to stretch the yarn as much as possible to make it as strong as possible, but also to prevent a decrease in strength during the subsequent processes of twisting, weaving, and adhesive treatment.

Incidentally, it is thought that the cause of the strength reduction at these stages is mainly due to the yarns being twisted together and the adhesive between the yarns and between the single yarns being fixed, which prevents the full strength of the initial yarn from being exerted. There is.

The number of twists during twisting is determined from the viewpoints of strength, fatigue resistance, etc., depending on the type of rubber product that requires reinforcement, and is determined by the rubber product manufacturer.

On the other hand, the conditions for fixing the single yarns with the adhesive are determined by the issue of how much the adhesive enters inside the cord at the stage of adhering the adhesive, and the subsequent baking conditions.

These conditions are determined to be suitable for improving adhesion to rubber in the subsequent vulcanization step and dimensional stability during vulcanization.

Sufficient heat must be applied to improve adhesive strength and reduce thermal shrinkage; however, such treatment has the drawback of decreasing strength and hardening the treated sag.

In order to reduce this hardening, the treated sag is then rubbed with edges to make it soft (so-called blading).
That is what is being attempted.

However, in the conventional manufacturing method of polyester synthetic fiber,
If you try to obtain sufficient flexibility while maintaining high strength and adhesive strength, problems such as weft breakage will occur.

For this reason, there is a drawback that sufficient adhesion strength cannot be obtained if the yarn is subjected to a treatment that softens the treated sag sufficiently.

In this way, in the conventional manufacturing method of polyester synthetic fibers, it has been difficult to optimize the rubber reinforcement manufacturing process from spinning to vulcanization, but it has not been possible to obtain processed fibers with high strength, high adhesiveness, and flexibility. is extremely difficult.

From this point of view, it has been strongly desired to improve the properties of polyester synthetic fibers as a rubber reinforcing material simply by changing the processing agent in the spinning conditions, but no such processing agent has been found so far. The current situation is that this is not the case.

For example, a cord to which a treatment agent of 50 parts of oleyl oleate and 50 parts of oleyl alcohol EO adduct, which is the most common type of conventional oil agent, is attached has satisfactory adhesion, but is significantly hardened.

For this reason, in an attempt to increase the flexibility of the treated cord, for example, from the viewpoint of reducing the depth of nylon yarn, as shown in Japanese Patent Publication No. 47-2023, a treatment agent that simply suppresses the penetration of adhesive into the inside of the cord is used. Synthetic fibers significantly reduce adhesion.

Similarly, in order to control the penetration of adhesive into the inside of the cord, Japanese Patent Publication No. 49-40154 proposes adding sorbitan fatty acid ester to improve the air permeability inside the adhesive-treated cord. .

However, in recent years, processes have been rationalized, such as in tire manufacturing, by reducing the number of plies and using mono-plies.
Furthermore, improved adhesiveness is required, and none of the conventional methods can improve the flexibility of treated sag while maintaining high adhesive strength.

As a result of intensive research, the present inventors discovered that it is possible to obtain a treated fiber with high adhesiveness, high strength, and flexibility by simply changing the treatment agent for polyester synthetic fibers. The present invention was achieved by discovering that by using it, effects previously unimaginable can be achieved.

That is, the present invention provides polyester synthetic fibers with a blending ratio of 500 to 1500 molecular weight and 65 to 80% by weight of smoothing agent A component, which is liquid at room temperature and solid in an atmosphere of 20° C. and 65% RH. A method for producing synthetic fibers for rubber reinforcement, which comprises applying a treatment agent containing 3 to 20% by weight of a polyhydric alcohol fatty acid ester activator having an HLB of 10.0 or less, and then subjecting the fiber to an adhesive treatment. .

The "normal temperature liquid smoothing agent A component with a molecular weight of 500 to 1,500" used in the present invention refers to a molecular weight of 500 to 1 with a hydrophobic note.
500 is an organic compound that is liquid at room temperature, and liquid at room temperature means that it is liquid at a normal operating temperature of 18 to 25°C, and is a component that has been conventionally used to improve the lubricity of textiles and machinery.

For example, esters of monohydric alcohols of monobasic acids such as oleyl oleate and instearyl oleate; monohydric alcohol esters of dibasic acids such as dioleyl adipate, ditridecyl sebacate, and dioleyl dithiopropionate; Examples of alcohol esters include tridecyl trimellitate and trioleyl trimellitate; examples of fatty acid esters of dihydric alcohols include neopentyl glycol diolate, 1.6 hexanediol diolate, and 4,4'impropylidene bisphenoxate. As a total fatty acid ester of polyhydric alcohol such as ethyl laurate, glycerin triolate, pentaerythritol tetraoleate, etc., the terminals of polyesters of dihydric alcohol and dibasic acid are blocked with monohydric alcohol or monobasic acid to increase the molecular weight. 1,500 or less, and urethane made of diphenylmethane diisocyanate and oleyl alcohol.

Furthermore, if the individual components have a molecular weight of 500 to 1,500, a smoothing agent mixture obtained by mixing these components can also be used as component A of the present invention, as long as the mixture itself is liquid at room temperature.

For example, even a small amount of oleyl stearate or oleyl oleate containing stearyl oleate generated by partial hydrogenation of oleyl oleate can be used as component A as long as they are compatible and liquid at room temperature.

Component A used in the present invention is liquid at room temperature and has a molecular weight of 50.
Must be between 0 and 1500.

If this component A becomes solid at room temperature, water repellency will occur and adhesiveness will decrease, and if the molecular weight is less than 500, it will volatilize and dissipate during heat treatment during spinning and adhesive treatment.
cannot demonstrate its effectiveness.

On the other hand, if the molecular weight exceeds 1,500, not only will the viscosity become high and ease of handling will deteriorate, but if more than 65% by weight is incorporated into the processing agent, it will be difficult to form an aqueous emulsion, making it impossible to use it industrially.

Therefore, the blending ratio of component A in the non-aqueous component of the treatment agent is 6.
It should be at least 5% by weight, preferably at least 67% and no more than 80% by weight.

If it is less than 65% by weight, adhesion will decrease if you attempt to coexist with component B and obtain sagging flexibility, and if it exceeds 80% by weight, it will not only be difficult to use it as an aqueous emulsion, but it will also be difficult to use with other fiber treatments. It becomes difficult to impart properties of the agent, such as antistatic performance and focusing performance, making industrial use difficult.

The component B of the polyhydric alcohol fatty acid ester type nonionic activator that is solid in an atmosphere of 20° C. and 65% RH and has an HLB of 10.0 or less used in the present invention is an alcohol with a valence of 3 or more, such as trimethylolpropane, glycerin, diglycerin, triglycerin, pentaerythritol,
Partial esters of sorbitan, sorbitol, etc. and higher fatty acids, such as behenic acid, arachic acid, stearic acid, palmitic acid, myristic acid, lauric acid, etc., and their ethylene oxide adducts, and. HLB=20(
1-MO/M) [However, MO: hydrophobic group molecular weight, M: activator molecular weight] The value of hydrophilic/lipophilic balance HLB is 10.0 or less, and in an atmosphere of 20°C and 65% RH. It is a polyhydric alcohol fatty acid ester activator that remains solid even when left undisturbed.

Specific compounds include trimethylolpropane monolaurate, glycerin monomyristate, diglycerin monopalmitate, triglycerin monobehenate, pentaerythritol monostearate, sorbitan monostearate, sorbitol monostearate, sorbitan distearate. , POE(2) sorbitan monostearate, etc.

The polyhydric alcohol fatty acid ester type nonionic activator used in the present invention does not exhibit its effect unless the above conditions are satisfied.

In other words, if it is liquid in an atmosphere of 20°C and 65% RH, it is impossible to control the penetration of the adhesive into the cord during adhesive dipping, and even if it is solid, if the HLB exceeds 10.0, Not only is the effect of controlling the penetration of the adhesive into the inside of the cord poor, but also flexibility cannot be obtained when the treatment conditions are adjusted to sufficiently increase the adhesiveness of the treated sag.

The reason for this is not clear, but it is thought that when combined with component A, a unique treatment agent film is formed on the polyester synthetic fiber, and even polyhydric alcohol fatty acid activators have this effect as their hydrophilicity increases. It disappears.

From this point of view, if emulsifying properties can be obtained, it is preferable that the HLB is low, and it is also preferable that the -OH group derived from the polyhydric alcohol remains.

The blending ratio of component B in the non-aqueous component used in the present invention is 3
At least 20% by weight, preferably at least 5% by weight1
Must be less than 5% by weight.

If it is less than 3% by weight, the effect of increasing the flexibility of the treated sag is poor, and if it exceeds 20% by weight, sufficient adhesive strength cannot be obtained even if the blending ratio of component A is optimized.

The "polyester synthetic fiber for rubber reinforcement" used in the present invention is, for example, a polyester synthetic fiber used as a reinforcing material for tires, rubber hoses, belts, etc., which has polyethylene terephthalate or polyethylene terephthalate as its main component, The main component is a high-molecular polyester copolymerized with three components: isophthalic acid, adipic acid, sehacic acid, 5-sodium sulfoisophthalic acid, propylene glycol, hexamethylene glycol, diethylene glycol, polyoxyethylene glycol, pentaerythritol, etc. It is a thread.

In the present invention, after adhering a treatment agent made by blending a predetermined amount of component A and component B to the polyester synthetic fiber, adhesive treatment is performed. Although it can be carried out in any of the previous steps, in order to uniformly adhere it to the fibers, it is preferable to attach it before it becomes a cord, that is, in steps such as spinning, stretching, and rewinding.

The most common method of attachment is to use an aqueous emulsion containing 5 to 30% by weight of the treatment agent and a roller set lubricating method. good.

The amount of treatment agent attached is 0.3 per 100 parts by weight of fiber.
~1.5 parts by weight is preferred, but is not particularly limited.

The adhesive used in the present invention is not particularly limited, but water-based adhesives generally used for rubber reinforcing synthetic fibers are particularly effective.

In other words, in general, the degree of penetration into the inside of the cord and the affinity for polyester synthetic fibers differ depending on the type of adhesive. For small ones, it is preferable to lower the B component ratio and strengthen the A component effect, but as long as the A component and B component ratios are within the range of the present invention, 4 to 8% by weight of adhesion, which is usually used for polyester synthetic fibers, can be used. The amount of agent attached is sufficient to demonstrate its effect.

As mentioned above, the treatment agent used in the present invention is characterized by a specific ratio of component A and component B, so the type of component A is selected according to the required characteristics of the yarn spinning process, yarn twisting process, and adhesive treatment process. This is extremely advantageous industrially.

That is, in order to reduce friction during spinning and twisting, materials with good smoothness such as oleyl oleate and dioleyl adipate can be selected, and in order to reduce smoke generation in the adhesive treatment process, for example, A material with good heat resistance such as 4,4'isopropylidene bisphenoxyethyl laurate can be selected.

In addition, for components other than component A and component B, conventionally used surfactants may be optionally used, and antioxidants and the like may be added in order to prevent static electricity and improve emulsifying properties.

In this way, according to the present invention, the combination of components A and B has a specific effect on polyester synthetic fibers, thereby achieving the good characteristics of conventional polyester synthetic fibers for rubber reinforcement, such as high modulus and low shrinkage. While maintaining high strength and adhesion, it is possible to improve processing flexibility.

Next, the present invention will be explained by examples.

Example 1 Polyethylene terephthalate fiber yarn made from a 0.4 mm, g, 250H nozzle {[η)=0.9O
Solvent; Orthochlorophenol Temperature: 35°C} to 4
Wind it onto a bobbin at a speed of 0 m/min.

Before winding up, the lower part of the roller is dipped and rotated in a 10% by weight aqueous emulsion having a treatment agent composition shown in Table 32.
The number of rotations of the roller is adjusted so that the amount of treatment agent attached to the fiber is 0.8% by weight.

Next, this undrawn yarn was stretched 5.8 times by two-stage heating stretching, and heat set at 220°C to 1500 deg.
/250 mil drawn yarn is obtained.

This drawn yarn is twisted at a rate of 39 times/cm for both the first and second twists using a ring twisting machine for tire cords to produce a two-strand cord of 1500 de.

The strength of this raw cord is measured using an Instron tensile tester (manufactured by Instron).

It is then treated with a PEXUL-based RFL adhesive shown in Table 1.

The above adhesive was adjusted to have a solid content concentration of 16% by weight, and after dipping the raw cord, it was dried at 100°C for 2 minutes under a fixed length.
Next, heat setting is performed at 230° C. for 1 minute under 2% elongation and 3% relaxation for 1 minute, and the wire is wound onto a bobbin while being lightly strained by the edge.

The strength of the resulting treated cord was measured using an Instron tensile tester, and in order to clarify the effect of the treatment agent, the strength retention rate was calculated by calculating what percentage of the strength of the previously measured raw cord was maintained. shall be.

Next, the bending hardness was measured using a Gurley set flexibility tester (manufactured by Nippon Rigaku Kogyo Co., Ltd.) and expressed in mg.Further, five cords were embedded in the rubber, and the peeling force after vulcanization was measured. The quality is evaluated and expressed in (kg/5C).

The results obtained are shown below together with the amount of adhesive adhered.

From these results, it can be seen that the treatment agent used in the present invention has better adhesive adhesion, strength retention, bending hardness, and adhesive properties than the comparative treatment agent.

No. 6 and 7 are typical processing agents shown in Japanese Patent Publication No. 47-2023, but when a high melting point smoothing agent is used, the amount of adhesive deposited decreases, and as a result, the adhesiveness decreases significantly. However, the bending hardness and strength retention rate have not been improved.

No. 8, 9, and 10 are conventional aqueous emulsions.
Although there have been no examples of commercialization of products with such a high leveling agent ratio, this study was conducted to clarify the characteristics of the present invention.

No. No. 8 is an example in which the smoothing agent has a low molecular weight, so it volatilizes during spinning and the effect decreases. No. 9 is a case in which only a liquid polyhydric alcohol fatty acid ester activator is used, and the adhesion is good, but the bending hardness is extremely high and the strength retention rate is also low.

No. 10 is an example in which all the smoothing agents are solid,
The amount of adhesive deposited is significantly reduced, the bending hardness is softened, but the adhesiveness is extremely reduced.

Example 2 Only the treatment agent applied in the same manner as in Example 1 was applied to No.
This is done by changing the A component ratio of the composition of 1.

When increasing or decreasing the proportion of A component in the processing agent, P O E (
n) Adjust emulsification by decreasing or increasing hydrogenated castor oil ether.

The results are shown in Table 4 along with the emulsifying properties. As a result, the A component ratio was less than 65% by weight in No. It can be seen that when the number is 11, the adhesiveness decreases.

It was possible to use it as an aqueous emulsion when the A component ratio ranged from 65% to 80% by weight, but when it reached 85% by weight, No. No. 16 creaming occurred and it could not be used even under stirring, so yarn spinning was stopped. It can be seen that samples Nos. 12 to 15 all showed good results in terms of strength retention, bending hardness, and adhesiveness.

Example 3 Using the same method as in Example 1, only the processing agent was added to No. A composition of No. 1 with a different B component ratio is used.

Emulsification was adjusted using emulsifiers other than component B, and all were usable.

The results are shown in Table 5. As a result, the B component was less than 3% by weight in No. If it is 17, the effect of reducing bending hardness is poor, and if it exceeds 20% by weight, it will be no. It can be seen that the adhesion of No. 23 decreases.

Example 4 A test was carried out in the same manner as in Example 1 except that only the processing agent was changed, and the results shown in Table 6 were obtained.

Processing agent No. HLB is 10 like 28, 29, 30
．． It is shown that when the value exceeds 0, the bending hardness increases and the strength retention rate also decreases, which clearly shows the uniqueness of the combination of component A and component B used in the present invention.

Claims (1)

[Claims] 1 Polyester synthetic fibers are mixed with 65 to 80% by weight of room temperature liquid leveling agent A component with a molecular weight of 500 to 1500 in the total non-aqueous components, and are solid in an atmosphere of 20°C and 65% RH and have an HLB. 10.0 or less, a polyester-based synthetic fiber for rubber reinforcement, characterized in that an adhesive treatment is applied after adhering a processing agent containing 3 to 20% by weight of a polyhydric alcohol fatty acid ester-based activator component B. manufacturing method.