JP2002317855A - Transmission belt and adhesion method of poly-phenylene benzobisoxazole fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the strength of a transmission belt by improving the adhesiveness of a core cord made of a poly-P-phenylene benzobisoxazole(PBO) fiber and a rubber composition of a belt body. SOLUTION: The core cord 18S is manufactured by forming a first coating layer 186 by reacting and fixing a mixture of an epoxy compound and latex to the outside of a raw yarn 184 prepared by twisting a filament 182 of PBO fiber, and further forming a second coating layer 187 by reacting and fixing RFL to the outside of the first coating layer 186. The transmission belt is manufactured by burying the core cord 18S in the rubber composition and vulcanizing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a power transmission,
For example, the present invention relates to a power transmission belt such as a toothed belt, a V belt, and a V-ribbed belt.

[0002]

2. Description of the Related Art A toothed belt, which is a type of power transmission belt, includes a belt body made of rubber having teeth for receiving load transmission, and a cord cord as a tensile strength member embedded in the longitudinal direction of the belt body. A canvas for covering the tooth surface of the belt body to prevent wear.

When a toothed belt is used as a timing belt for an automobile, it is necessary to be able to withstand use in a high-temperature and high-load environment. Various improvements have been attempted. Specifically, hydrogenated nitrile rubber with excellent heat resistance is used as the raw material rubber for the belt body instead of conventional chloroprene rubber, and high-strength aramid fiber is used for the core wire instead of glass fiber. As a canvas, a woven fabric made of aramid fiber having excellent abrasion resistance has been used instead of a nylon-6,6 woven fabric.

A vulcanization method for forming a three-dimensional structure on a belt body by appropriately treating a rubber composition obtained by adding a vulcanizing agent such as sulfur or an organic peroxide, a plasticizer, or the like to the raw material rubber by heating or the like is used. Applied, thereby improving elasticity, tensile strength and dimensional stability. The cord is made of rubber glue or resorcinol formaldehyde latex (hereinafter “R”).
FL) is embedded in the unvulcanized belt body through an adhesive process of applying and drying an adhesive, and the adhesive reacts with the rubber of the belt body by the heating reaction at the same time as the vulcanization molding of the belt body. Strongly adhered.

In recent years, poly-P-phenylene benzobisoxazole fibers (hereinafter abbreviated as "PBO fibers") having higher strength and higher elastic modulus than aramid fibers and having excellent heat resistance, flame retardancy and dimensional stability. ) Is researched and developed,
It is desired to use this for a cord. However, PBO fibers have extremely high crystallinity and a dense structure, so they have poor adhesion to rubber glue or RFL adhesive, and do not adhere to the rubber of the belt body even if the conventional cords are subjected to a conventional bonding treatment. There is. In the case of a toothed belt subjected to a large repetitive load, if the adhesion between the cord and the belt main body is poor, there is a problem that interface destruction occurs between the two and early damage of the toothed belt occurs.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above problems. The purpose is to improve the strength.

[0007]

The power transmission belt of the present invention comprises:
A cord comprising a poly-P-phenylene benzobisoxazole fiber is embedded in a rubber composition constituting a belt main body and vulcanized, and the two are integrated, and the surface of the cord is provided with: It is characterized in that after the primary treatment in which a mixture of an epoxy compound and a latex is adhered and heat treatment is performed, a secondary treatment in which a resorcinol formalin latex adhesive is adhered and heat treatment is performed. Thereby, the adhesion between the cord and the rubber composition is improved, and the strength of the toothed belt is improved.

The main component of the rubber composition used for the belt body is preferably chloroprene rubber or hydrogenated nitrile rubber having excellent heat resistance.

The epoxy compound used for the primary treatment is preferably a polyepoxy compound having two or more epoxy rings in one molecule and is water-soluble.
Specifically, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether or sorbitol polyglycidyl ether is preferred.

As the latex used in the primary treatment, acrylonitrile butadiene rubber latex or chloroprene rubber latex is preferable.

In the primary treatment, the cord is immersed in a primary treatment solution, which is an aqueous solution to which an epoxy compound, a latex, and a ring-opening catalyst for the epoxy compound are added, and after immersion, at 230 ° C. to 280 ° C. for a predetermined time. Heat treatment is preferred, and at this time, the ring opening catalyst is preferably an imidazole compound. The imidazole compound is
For example, it is 2-methylimidazole, and it is preferable to add substantially 10% by weight to the epoxy compound.

In the primary treatment, the solid content after treatment is preferably 3 to 8% by weight based on the cord before treatment.

The method of bonding poly-P-phenylene benzobisoxazole fibers according to the present invention is a method of performing a heat treatment by adhering a mixture of an epoxy compound and latex to the surface of poly-P-phenylene benzobisoxazole fibers. And a secondary treatment in which a resorcinol-formalin latex adhesive is adhered and a heat treatment is performed.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a part of the toothed belt. The toothed belt 10 includes a belt body 12 having a tooth portion 12 a formed on one surface, and the tooth portions 12 a are provided at regular intervals along the longitudinal direction of the belt body 12. The outer surface of the tooth portion 12a is covered with a canvas 16 to prevent abrasion. A plurality of cores 18 arranged in parallel in the width direction are embedded in the belt body 12, and each of the cores 18 extends in the longitudinal direction.

A vulcanizing press method for vulcanizing the rubber composition and simultaneously press-molding the rubber composition is applied to the belt body 12. Rubber composition is used for raw rubber such as chloroprene rubber and rubber with improved heat aging resistance such as hydrogenated nitrile rubber.
In addition to vulcanizing agents such as sulfur or organic oxides, vulcanization accelerators, reinforcing agents such as carbon black, zinc white, stearic acid, plasticizers, anti-aging agents, etc. are appropriately added according to the intended use. It is. When vulcanizing an unvulcanized rubber composition,
A covalent bond is generated between the rubber molecules to form a three-dimensional structure. Thereby, the elasticity, tensile strength and dimensional stability of the belt main body 12 are improved.

As the canvas 16, a woven fabric made of aramid fiber, nylon fiber or the like having excellent heat resistance and abrasion resistance, or a blended or mixed woven fabric thereof is used. It is preferable to use fibers having elasticity in the longitudinal direction of the belt body 12 and fibers having little elasticity in the width direction. The weave configuration is not particularly limited, such as plain weave, satin weave and twill weave. The canvas 16 is brought into close contact with the belt body 12 before vulcanization, and is integrated with the belt body 12 during vulcanization and pressurization.

The core wire 18 is obtained by spirally winding a pair of core cords having different twisting methods, for example, an S-strand core cord 18S and a Z-strand core cord 18Z. Each of the cords 18S, 18Z has a plurality of types of coat layers (see FIG. 2; reference numerals 186, 1) on the outer side of the yarn obtained by twisting poly-P-phenylene benzobisoxazole fibers (PBO fibers).
87, 188). PBO fiber is an organic fiber having high strength and high elastic modulus and excellent in heat resistance, flame retardancy and dimensional stability. The plurality of coat layers function as an adhesive for improving the adhesiveness between the PBO fiber constituting the core wire 18 and the rubber constituting the belt body 12.

FIG. 2 is a perspective view schematically showing a structure of one of a pair of cords constituting the cord 18, that is, an S-twist cord 18S, which is partially cut away. First, PB
Each of the small-diameter filaments 182,
The bottom is twisted in the direction. Then, three filaments 182 after the ply twist are collected and ply-twisted in the same S direction as the ply twist direction, whereby the raw yarn 184 of the S stranded core cord is obtained. In addition, the thickness, the number, the number of twists, and the method of twisting of the filament 182 are not limited to those described above.
It goes without saying that it can be appropriately changed according to the size of the toothed belt 12 and the required tensile strength. For example, you may twist in the Z direction opposite to the twist direction of a top twist in a bottom twist.

The plurality of coat layers formed around the yarn 184 are made of a mixture of a latex, which is an emulsion of natural rubber or synthetic rubber, and an epoxy compound, and the first coat formed outside the yarn 184. And a second coat layer 187 made of an RFL adhesive and formed outside the first coat layer 186.

The RFL adhesive is obtained by applying and drying an RFL solution, which is an aqueous solution obtained by mixing an RF resin, which is an initial condensate of resorcinol and formaldehyde, and various latexes onto an adherend. Generally, RFL adhesives have good compatibility with natural rubber, styrene-butadiene rubber, chloroprene rubber, and the like, and a high and stable adhesive strength can be obtained by covalent or hydrogen bonding to these rubbers. Widely used as an adhesive between. Further, since the RFL solution is water-soluble, there is an advantage that there is less problem of safety and health compared with a solvent-based adhesive such as rubber paste. However, since the adhesiveness to hydrogenated nitrile rubber is inferior, a method of improving the adhesive force by interposing a rubber paste between the RFL adhesive and the hydrogenated nitrile rubber is generally performed.

On the other hand, it is known that the RFL adhesive has good adhesion to nylon fibers, rayon fibers, glass fibers, etc., but has poor adhesion to aramid fibers. Therefore, a method of improving the adhesive force by interposing an epoxy adhesive or an isocyanate adhesive between the RFL adhesive and the aramid fiber has been performed. PBO fiber, like aramid fiber, has R
It has been found that adhesion to the FL adhesive is poor. It is considered that this is because the PBO fiber has a very high crystallinity and a dense structure, so that almost no bonding occurs between the PBO fiber and the RF component in the RFL adhesive. It is conceivable to interpose an adhesive made of an epoxy compound as in the case of the aramid fiber, but this does not provide a sufficient adhesive strength. Therefore, in this embodiment, the PBO fiber and the RF
A first coat layer 186 made of a mixture of an epoxy compound and a latex is interposed between the adhesive and the L adhesive, thereby improving the adhesive strength between the two.

FIG. 3 is a diagram schematically showing a code processor for forming the first coat layer 186. As shown in FIG. First, a solution of an epoxy compound and a latex are mixed, and a primary treatment liquid to which a ring-opening catalyst for an epoxy compound such as an imidazole compound or an aromatic amine, phenolic resin or acid anhydride, that is, a curing agent is added, is prepared. . The raw yarn 184 is wound around the control roll 30 on the right side in the drawing, and the raw yarn 184 is drawn from the control roll 30 and guided to the primary treatment liquid in the immersion tank 32. The primary treatment liquid is stirred by the stirrer 34.

After the raw yarn 184 is immersed in the primary treatment liquid,
It is guided to an upper drying furnace 36, where it is subjected to a heat treatment. The primary treatment liquid attached to the surface of the raw yarn 184 by the heat treatment is dried, and only the epoxy compound and latex, which are solid components, remain on the raw yarn 184, and this becomes the first coat layer 186. Yarn 1 on which first coat layer 186 is formed
84 is wound by the winding roll 38 on the left side in the figure.

Between the drying furnace 36 and the winding roll 38,
A speed control roller 40 for controlling the speed of the raw yarn 184 is provided, whereby the residence time of the raw yarn 184 in the drying furnace 36, that is, the heat treatment time is controlled. In addition,
The primary treatment for forming the first coat layer 186 is not limited to the above method. For example, a primary treatment liquid may be applied to the surface of the raw yarn 184 by spraying.

The epoxy compound is a polyepoxy compound having two or more epoxy rings in one molecule as long as it is water-soluble and has an appropriate viscosity in consideration of wetting to PBO fibers. preferable. Examples include diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, or sorbitol polyglycidyl ether. When the epoxy ring reacts with the curing agent, the epoxy compound is three-dimensionally cross-linked and cured, and functions as an adhesive.

The latex used here is acrylonitrile butadiene rubber (hereinafter abbreviated as "NBR").
Latex or chloroprene rubber latex is preferred.

Examples of the curing agent include 2-methylimidazole which is an imidazole compound, diphenylamine, methylbenzylamine, dimethylbenzylamine, trimethylbenzylammonium chloride which is an amine compound, and sodium hydroxide and potassium hydroxide. . The ring-opening reaction of the epoxy compound changes according to the type and amount of the curing agent, and the type and the amount of addition are appropriately selected according to the time required for the operation. For example, in the case of 2-methylimidazole having a relatively short gelation time and high activity, it is preferable to add about 10% by weight to the epoxy compound.

The solid content after the treatment is 3 to
10% by weight is preferred. If the solid content is less than 3% by weight, sufficient adhesive strength cannot be obtained, and if it is more than 10% by weight, the coating layer itself becomes thick and may become a boundary layer at the time of fracture. The solid content is adjusted according to the concentration of the processing solution, and the concentration of the processing solution is preferably about 10% in order to obtain the solid content.

The heat treatment conditions are as follows: processing temperature 230 ° C. to 280
C. and a processing time of 1 to 2 minutes are preferred. When the temperature is lower than 200 ° C., the reaction of the epoxy compound is not sufficient, and the adhesiveness is reduced. Regarding the tension during the treatment, the melting point of the PBO fiber was 65
The temperature is not particularly limited because it is relatively high at 0 ° C. and the elongation due to a temperature change from room temperature to the processing temperature is small.

The second coat layer 187 is coated with an RFL solution, which is an aqueous solution obtained by mixing an RF resin, which is an initial condensate of resorcinol and formaldehyde, with latex, that is, a core having the first coat layer 186 formed thereon. It is obtained by coating and drying the cord 18S. The latex used here is preferably a vinylpyridine-styrene-butadiene copolymer (hereinafter abbreviated as "VP-SBR") latex.
The secondary processing for forming the second coat layer 187 may be performed in the same manner as the primary processing. That is, the roll around which the raw yarn 184 provided with the first coat layer 186 obtained by the primary treatment is wound is used as the take-out roll 30, and the liquid in the immersion tank 32 is changed to the RFL solution, and the same immersion treatment is performed. And heat treatment.

When the raw rubber of the belt body 12 is a hydrogenated nitrile rubber, it is preferable to further provide a third coat layer 188 made of a rubber paste outside the second coat layer 187. The rubber paste is obtained by dissolving the same hydrogenated nitrile rubber as the raw rubber in an appropriate solvent such as toluene and adding an additive thereto.
The two adhere to each other by an anchor effect of penetrating into the unevenness of the adhered surface and hardening. The tertiary treatment for forming the third coat layer 188 may be performed in the same manner as the above-described primary treatment.
The drying temperature of the rubber glue is preferably set to a low processing temperature of about 100 ° C., and the processing time is preferably about 60 seconds.

The Z-strand core cord 18Z is the same as the S-strand core cord 18Z except that the lower twist and the upper twist are in the Z direction.
It is substantially the same as S. A pair of cords 18
A core wire 18 formed by spirally winding S and 18Z is embedded in the belt body 12 before vulcanization, and at the same time as the belt body 12 is vulcanized, each coat layer 186, 187 and 188 is formed.
Is heated and thermally reacted, whereby the core wire 18 is firmly adhered to the belt body 12.

As described above, the toothed belt 1 of the present embodiment
0, the surface of the PBO fiber (filament 184) and the RF
The first coat layer 186 made of a mixture of an epoxy compound and a latex between the L adhesive (the second coat layer 187)
Thus, the adhesiveness between the cord 18 made of PBO fiber and the rubber composition of the belt body 12 can be improved, and the strength of the toothed belt 10 can be improved. In addition, since both the first processing liquid and the second processing liquid used in the present embodiment are water-soluble, they are superior in environmental hygiene as compared with conventional processing using an organic solvent.

[0035]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.

In the following Examples 1 to 4 and Comparative Example 1, sample pieces were respectively formed to measure the adhesive strength of the core wire to the rubber composition for belts in which only the composition of the primary treatment liquid was changed. A strength test was performed. Table 1
In the above, "---" indicates that it is not added.

[0037]

[Table 1]

Example 1 First, 1000 denier PBO fiber (manufactured by Toyobo Co., Ltd.)
Zylon AS 1110dtx filament) was twisted in the S-direction, and three PBO fibers after the twisting were aligned and then twisted in the S-direction to obtain an original yarn cord. The raw yarn cord was subjected to a primary treatment and a secondary treatment by a cord processor shown in FIG.

In the primary treatment liquid, diglycerol polyglycidyl ether (Denacol EX421, manufactured by Nagase Kasei Kogyo Co., Ltd.) was used as an epoxy compound, and NBR latex containing 45% by weight of a latex component (Nipol NUN5100, manufactured by Zeon Corporation) was used as a latex. ), And a 10% solution of sodium hydroxide was used as a ring opening catalyst for the epoxy compound. 1: 1 solid component of epoxy compound and latex
2% by weight of diglycerol polyglycidyl ether and 4.44% by weight of NBR latex (2% by weight of solid component) so that
2% by weight (0.2% by weight of a component) was added to a 10% sodium hydroxide solution so as to have an amount of 0% by weight, and water was further added to make up a total of 100% by weight. I mixed.

The primary treatment liquid formulated as described above was mixed with 50
0 ml was prepared, and the yarn cord was immersed by a cord processor, and then heat-treated at a treatment temperature of 250 ° C. and a treatment time of 100 seconds. At this time, the solid content was 2% by weight based on the original yarn.

The RFL solution as a secondary processing solution will be described. First, 1.88% by weight of resorcinol was dissolved in water, and 2.76% by weight of a 37% formalin solution and 1% by weight were dissolved.
0.51% by weight of 0% sodium hydroxide solution was added and stirred. This was aged at 30 ° C. for 6 hours. After confirming that the RF resin was generated, the latex component was 40.5%.
% Of vinyl pyridine-styrene-butadiene copolymer rubber latex (Nipol 2518FS, manufactured by Zeon Corporation)
A secondary treatment liquid was prepared by adding 10% by weight, 49.43% by weight of aqueous ammonia having a concentration of 28%, and further adding water so as to be 100% by weight as a whole, and aged at room temperature for 12 hours.

The secondary treatment solution formulated as described above was mixed with 50
0 ml was prepared, and the primary-processed raw yarn cord was immersed by a code processor.
The heat treatment was performed under the condition of 00 seconds.

Subsequently, a sample piece was prepared using the cords obtained by the primary processing and the secondary processing. The compounded rubber A shown in Table 2 was used as the rubber composition used for the sample pieces.

[0044]

[Table 2]

As shown in Table 2, chloroprene rubber was used as the raw rubber for compounded rubber A. For 100 parts by weight (phr) of this chloroprene rubber, 40 parts by weight of carbon black, 2 parts by weight of stearic acid, and petroleum oil 10 parts by weight of a system softener, 4 parts by weight of Baintar, 5 parts by weight of zinc white, 1.5 parts by weight of N-phenyl-β-naphthylamine, 0.75 parts by weight of 2-benzothiazolyl sulfide, diphenyl It contains 0.75 parts by weight of guanidine and 3.5 parts by weight of sulfur as a vulcanizing agent.

A rubber sheet (reference numeral 56; see FIG. 4) having a thickness of 4 to 5 mm is obtained from the compounded rubber A by extrusion molding, and the rubber sheet 56 is cut into a length of 120 mm.
A processed cord cord (reference numeral 54; see FIG. 4) having a width of 15 mm and a length of 120 mm was arranged without gaps. In Example 1, the diameter of the cord 54 was about 0.7 mm, and the number thereof was 21. A canvas (reference numeral 52; see FIG. 4) is attached on the core cord 54 for protection. The sample thus obtained (symbol 50; see FIG. 4) was placed in a mold and vulcanized under pressure. The vulcanization conditions were 150 ° C. × 20 minutes. After vulcanization and cooling at room temperature, the adhesive strength was measured by a tensile tester (AG-500 type autograph manufactured by Shimadzu Corporation).

FIG. 4 is a perspective view showing a state where the sample piece 50 is attached to a tensile tester. First, the canvas 52 is peeled to some extent from the sample piece 50, and a cut is made between the core cord 54 and the rubber sheet 56 at one end of the stripped side, and the end of the core cord 54 and the end of the rubber sheet 56 are respectively separated. The rubber sheet 56 was pulled at a pulling rate of 50 mm / min in the direction in which it was attached to the chucks 60 and 62 and separated from each other, that is, the cord 54 was pulled upward in the figure, and the rubber sheet 56 was drawn downward in the figure.
The force required for the core cord 54 and the rubber sheet 56 to peel off was measured, and the average of five peak values was evaluated as the adhesive strength. Further, the peeled part at that time was visually evaluated.

In Example 1, as shown in Table 1,
The adhesive strength was 100 N / 15 mm, and it was confirmed that the peeled portion was at the interface between the cord 54 and the rubber sheet 56.

Example 2 In Example 2, a sample piece 50 was prepared in the same manner as in Example 1 except that the components of the primary treatment liquid were different, and the adhesive strength was evaluated. In the primary treatment liquid of Example 2, as shown in Table 1, the epoxy compound was 5% by weight, latex 11.1% by weight (solid content 5% by weight) and sodium hydroxide aqueous solution 5% by weight. It increased by 2.5 times of Example 1. At this time, the solid content was 5% by weight based on the original yarn, and the adhesive strength was 110 N / 15 mm. It was confirmed that the peeled portion was an interface between the cord 54 and the rubber sheet 56.

Example 3 In Example 3, a sample piece 50 was prepared in the same manner as in Examples 1 and 2 except that the components of the primary treatment liquid were different, and the adhesive strength was evaluated. In the primary treatment liquid of Example 3, Table 1
As shown in Table 2, the epoxy compound was 5% by weight, the latex was 11.1% by weight (solid content 5% by weight), and the amounts were the same as in Example 2. Also, as a ring-opening catalyst for epoxy compounds, sodium hydroxide having a concentration of 10% was used instead of sodium hydroxide.
-Methylimidazole was used, and it was added in an amount of 5% by weight (0.5% by weight of component), which was 1/10 of the epoxy compound. At this time, the solid content was 5
% By weight, and the adhesive strength was 140 N / 15 mm. It was confirmed that the peeled portion was not at the interface between the cord 54 and the rubber sheet 56 but was broken inside the rubber sheet 56.

Example 4 In Example 4, a specimen 50 was prepared in the same manner as in Examples 1 to 3 except that the components of the primary treatment liquid were different, and the adhesive strength was evaluated. In the primary treatment liquid of Example 4, as shown in Table 1, the epoxy compound was 5% by weight and the latex was 1%.
1.1 wt% (solid content: 5 wt%), and the amounts were the same as in Example 3. In addition, the same 10% concentration of 2-methylimidazole as in Example 3 was used as a ring-opening catalyst for the epoxy compound.
Only 0.5% by weight (0.05% by weight of component) was added. At this time, the solid content was 5% by weight based on the original yarn.
And the adhesive strength was 90 N / 15 mm. It was confirmed that the peeled portion was at the interface between the cord cord 54 and the rubber sheet 56.

Comparative Example 1 In Comparative Example 1, a sample 50 was prepared in the same manner as in Examples 1 to 4 except that the components of the primary treatment liquid were different, and the adhesive strength was evaluated. In the primary treatment liquid of Comparative Example 1, as shown in Table 1, 2.22% by weight of the epoxy compound and the same concentration of 10% as in Examples 1 and 2 as a ring-opening catalyst for the epoxy compound.
0.28% by weight of an aqueous solution of sodium hydroxide was added, and no latex was added. Also, the epoxy compound is P
2.24% by weight of aerosol OT having a concentration of 5% was added as a wetting agent for easily adhering to the BO fiber. At this time, the solid content was 0.2% by weight based on the original yarn, and the adhesive strength was 50 N / 15 mm. It was confirmed that the peeled portion was at the interface between the cord cord 54 and the rubber sheet 56.

From the above results, it can be seen that in all of Examples 1 to 4 in which latex was added to the primary treatment liquid, the solid content and the adhesive strength were improved as compared with Comparative Example 1 in which latex was not added. Understand.

When Examples 1 and 2 are compared, when the solid components of the epoxy compound and the latex are increased by 2.5 times, the amount of adhered solids is also increased by 2.5 times, and the adhesive strength is also improved. Comparing Examples 2 and 3, it can be seen that the use of 2-methylimidazole as the ring-opening catalyst rather than sodium hydroxide significantly improves the adhesive strength. In addition, at this time, since the destruction occurs not in the interface but in the rubber sheet 56 due to the tension, it is understood that the cord cord 54 and the rubber sheet 56 are firmly adhered. Example 3
The difference between 4 and 4 is that the amount of the ring-opening catalyst (2-methylimidazole) is 10% by weight or 1% with respect to the epoxy compound.
The only difference is the weight%. At this time, there is no difference in the amount of solids attached, but there is a large difference in the adhesive strength, indicating that an amount of the catalyst of about 10% by weight with respect to the epoxy compound is appropriate.

In the above embodiment, the present invention is applied to a toothed belt, but the present invention can also be applied to a transmission belt such as a V-belt or a V-ribbed belt.

[0056]

As described above, in the power transmission belt of the present invention, since a suitable bonding treatment is performed on the PBO fiber, a toothed belt having improved adhesion between the core cord made of the PBO fiber and the main rubber can be obtained. There is an advantage that it can be.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing an embodiment of a toothed belt according to the present invention.

FIG. 2 is a perspective view showing a part of the cord shown in FIG.

FIG. 3 is a view schematically showing primary processing of a cord in a manufacturing process of the toothed belt shown in FIG. 1;

FIG. 4 is a view showing an evaluation test of the adhesive strength between the cord and the rubber composition, and is a perspective view showing a sample piece attached to a tester.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Toothed belt 12 Belt main body 18 Core wire 18S, 18Z Core cord 184 Yarn 186 First coat layer 187 Second coat layer 188 Third coat layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) D06M 15/693 F16G 1/28 E F16G 1/28 5/06 A 5/06 B29K 9:00 // B29K 9:00 63:00 63:00 105: 08 105: 08 C08L 21:00 C08L 21:00 D06M 15/72 (72) Inventor Hiroyuki Yamamoto 3-15-1 Tsuneda, Ueda City, Nagano Prefecture Shinshu University Textile Science Attached F-term in polymer research facility (reference) 4F072 AA04 AB05 AC10 AC12 AD02 AG03 AG12 AH26 AJ04 AJ11 AK14 AL19 4F213 AA45 AB18 AD16 AG16 WA03 WA14 WA52 WA57 WB01 WB11 WE01 WF01 WF05 WK01 WK03 WW06 AB03 AC03 CA34 CA49 CA68 CA70

Claims (11)

[Claims] 1. A power transmission belt in which a core cord made of poly-P-phenylene benzobisoxazole fiber is embedded in a rubber composition constituting a belt body and vulcanized, and the two are integrated to form a belt. On the surface of the wire cord, after a primary treatment of applying a mixture of an epoxy compound and latex and performing a heat treatment, a secondary treatment of applying a resorcinol formalin latex adhesive and performing a heat treatment is performed. And transmission belt. 2. The power transmission belt according to claim 1, wherein a main component of the rubber composition is chloroprene rubber or hydrogenated nitrile rubber. 3. The power transmission belt according to claim 1, wherein the epoxy compound is a polyepoxy compound having two or more epoxy rings in one molecule and is water-soluble. 4. The power transmission belt according to claim 3, wherein the epoxy compound is diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether or sorbitol polyglycidyl ether. 5. The power transmission belt according to claim 1, wherein the latex is acrylonitrile butadiene rubber latex or chloroprene rubber latex. 6. The core cord is immersed in a primary treatment liquid, which is an aqueous solution to which the epoxy compound, the latex, and the ring-opening catalyst for the epoxy compound are added in the primary treatment, and after immersion, at 230 ° C. to 280 ° C. The power transmission belt according to claim 1, wherein the power transmission belt is heat-treated at a predetermined temperature for a predetermined time. 7. The power transmission belt according to claim 6, wherein the ring opening catalyst is an imidazole compound. 8. The power transmission belt according to claim 7, wherein the ring opening catalyst is 2-methylimidazole. 9. The power transmission belt according to claim 6, wherein the ring opening catalyst is added in an amount of substantially 10% by weight based on the epoxy compound. 10. The power transmission belt according to claim 1, wherein the solid content adhesion amount after the primary treatment is 3 to 8% by weight based on the cords before the primary treatment. 11. A primary treatment in which a mixture of an epoxy compound and a latex is adhered to the surface of a poly-P-phenylene benzobisoxazole fiber to perform a heat treatment, and a heat treatment in which a resorcinol formalin latex adhesive is further adhered. And performing a secondary treatment to be performed. A method for bonding poly-P-phenylene benzobisoxazole fibers.