JPH09303487A - Transmission belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the permanent set resistance and crack resistance by forming the partial element of a belt with the mixed phase of the ACSM phase using alkylated chlorosulfonated polyethylene as the rubber component and the phase using polyethylene halide as the rubber component. SOLUTION: Three upper layers 2 of rubber canvas, an adhesive rubber layer 4 arranged with high-strength, low-ductility core wires 3, a compressed rubber layer 5 which is an elastic body layer, and a lower layer 2 of the rubber canvas are vertically laminated to form a V-belt 1. The compressed rubber layer 5 which is a part of the laminated V-belt 1 is formed with the mixed phase of the ACSM phase using alkylated chlorosulfonated polyethylene as the rubber component and the phase using polyethylene halide as the rubber component, and single fibers 6 are mixed while being oriented in the width direction of the belt 1. The heat resistance of belt elements is improved, and the permanent set resistance and crack resistance can be consistently improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission belt, and more particularly to an invention that is advantageous for improving the running life of friction power transmission belts such as V-ribbed belts and V-belts.

[0002]

2. Description of the Related Art In recent years, the ambient temperature in the engine room of automobiles has risen compared to the conventional temperature, and the demand for heat resistance of transmission belts used therein has increased. Therefore, in such a power transmission belt, it has been considered to use a chlorosulfonated polyethylene-based material having excellent heat resistance as the rubber material. However, this type of rubber material has problems in terms of durability and low temperature characteristics (cold resistance), and its improvement is desired.

On the other hand, in Japanese Patent Laid-Open No. 4-212748, an alkylated chlorosulfonated polyethylene (hereinafter referred to as "alkylated chlorosulfonated polyethylene", which has an alkyl group introduced into its main chain to reduce the crystallinity, , AC
The abbreviation "SM" is sometimes used) as the compression rubber of the power transmission belt. That is,
This is intended to improve the low temperature characteristics of the transmission belt by setting the chlorine content of the ACSM to 15 to 35% by weight and the sulfur content to 0.5 to 2.5% by weight.

Further, Japanese Patent Application Laid-Open No. 63-57654 discloses that chlorosulfonated polyethylene is blended with dimaleimide, nickel dithiocarbamate and thiuram polysulfide to improve its compression set resistance.

[0005]

However, the above-mentioned ACSM
In the case of a power transmission belt that uses, if the running (usage) time becomes long, it will be repeatedly subjected to mechanical stimulus, and the deformation of the belt will gradually increase and sink into the pulley, causing so-called sag (permanent distortion). This problem becomes noticeable especially when used under high load or high tension.

The above-mentioned settling is basically caused by deterioration of rubber, and this deterioration is caused by heat. Conventionally, as a factor relating to heat that influences the running life of the transmission belt, the ambient temperature of the transmission belt is known. Also, it has been considered that an external heat factor such as frictional heat generated by friction between the belt and the pulley during traveling of the belt is a problem, and a countermeasure against this is taken.

However, regarding the running life of the power transmission belt, not only the external heat factor is a problem, but the rubber itself constituting the belt generates heat as the belt moves, and the heat is stored inside. It needs to be a problem.
That is, due to internal heat factors such as heat generation and heat storage, the softening / deterioration of the rubber progresses, which is one of the causes of the above-mentioned settling. Then, this heat generation and heat storage becomes remarkable in the compressed rubber layer of the belt, and the belt life is shortened. In other words, even if the heat resistance of the belt against heat as an external factor is improved, the running life of the belt cannot be significantly extended unless the amount of heat generation / heat storage, which is an internal factor, is reduced.

On the other hand, the transmission belt using the ACSM also has a problem that if the running (usage) time becomes long, the belt is cracked as a result of being repeatedly subjected to mechanical stimulus, and the crack is compressed. It easily occurs in the rubber layer. In particular, when the diameter of the pulley around which the power transmission belt is wound is small, the bending deformation of the belt when passing through the pulley becomes large, so that the problem of the above-mentioned cracking becomes significant.

Considering the problems of the settling and the problems of the cracks, the former is that the mechanical energy applied from the outside with the movement of the belt is converted into heat and the compressed rubber layer stores heat inside. On the other hand, in the latter case, the latter causes the mechanical energy to be locally converted into heat and cause localized stress concentration in the compressed rubber layer. Therefore, the heat resistance / heat storage characteristics and the crack resistance characteristics of the belt have a relationship that they change in a contradictory direction such that when one is improved, the other is deteriorated, and there is a problem that it is difficult to achieve both at the same time.

Japanese Unexamined Patent Publication (Kokai) No. 4-212748, which has been cited as showing the prior art, prevents hardening of rubber due to agglomeration of chlorine at a low temperature of -30 ° C. or lower by using ACSM as a rubber material of a transmission belt. However, it does not suggest countermeasures against the above-mentioned settling and cracking.

[0011]

Means for Solving the Problems The present inventor has made various studies on the above problems, and as a result of repeating trial manufacture and experiments, a rubber material excellent in sag resistance (permanent strain resistance) and crack resistance are obtained. It was found that the desired effect can be obtained by combining a rubber material having excellent (bending fatigue resistance) and forming a specific phase-separated structure (mixed phase), and completed the present invention. It has come to do. Hereinafter, the invention according to each claim of the claims will be specifically described.

In the invention according to claim 1, at least a part of the elements of the belt is formed by a mixed phase of an ACSM phase having an alkylated chlorosulfonated polyethylene as a rubber component and a phase having a halogenated polyethylene as a rubber component. It is a transmission belt that is characterized by being.

The invention according to claim 2 is characterized in that, in the transmission belt according to claim 1, the ACSM phase forms a continuous phase.

The alkylated chlorosulfonated polyethylene is a chlorosulfonated low-density polyethylene having a linear molecular structure.

(Both sag resistance and crack resistance are compatible) With the above-mentioned structure, the halogenated polyethylene phase converts the mechanical energy acting on the transmission belt into heat to generate local heat. By avoiding stress concentration, that is, by causing the halogenated polyethylene phase to function as a buffer phase, it is possible to suppress the generation and growth of cracks in the power transmission belt, and to obtain sag resistance by the ACSM phase and It becomes possible to obtain cracking properties.

That is, the transmission belt is repeatedly bent by passing through the pulleys, but since the ACSM phase, which is advantageous in terms of sag resistance, forms one of the mixed phases, the entire belt element is Sag resistance close to that when formed by the ACSM composition is obtained. On the other hand, when the entire element is formed of the ACSM composition, the mechanical energy is hard to be converted into heat,
Although the occurrence of cracks becomes a problem, mechanical energy is easily converted into heat in the halogenated polyethylene phase, so the halogenated polyethylene phase functions as a buffer phase to prevent stress concentration and prevent cracking and growth. It

Here, the form of the mixed phase is ACSM.
One of the phases and the halogenated polyethylene phase forms a continuous phase and the other forms a dispersed phase, both phases form a continuous phase, or the two phases are dispersed together. It may be in any form. Among them, as in the invention according to claim 2, the ACSM
Having the phases form a continuous phase is advantageous in obtaining high sag resistance comparable to when the entire belt element is formed of an ACSM composition. That is, a dispersion system in which the ACSM phase forms a continuous phase and a large number of halogenated polyethylene phases are finely dispersed and AC
A marble system in which the SM phase and the halogenated polyethylene phase are intermingled with each other in a marble form (to form a red-wash pattern) is preferable.

As the halogenated polyethylene, commercially available chlorinated polyethylene or the like can be optionally used, but among them, so-called non-crystalline or anti-crystalline grade is suitable.

(Regarding Weight Ratio of ACSM and Halogenated Polyethylene) With respect to the weight ratio of ACSM and halogenated polyethylene, as in the invention according to claim 3, 100 parts by weight of ACSM and 10 parts of halogenated polyethylene are used. It is preferable that the amount is -100 parts by weight.
When the amount of halogenated polyethylene exceeds the upper limit of this weight ratio, the amount of ACSM is too small, and the expected sag resistance cannot be obtained, and when the amount of halogenated polyethylene becomes less than the lower limit of this weight ratio. The expected crack resistance cannot be obtained.

If the above weight ratio is out of the above range,
When a mixed phase is to be formed by kneading an unvulcanized ACSM composition with an unvulcanized halogenated polyethylene or a composition thereof, the phase separation should be performed so that the expected ACSM phase becomes a continuous phase. Hard to get.

However, if the method of adding the halogenated polyethylene to the ACSM composition after finely pulverizing the halogenated polyethylene to 100 μm or less in advance, the halogenated polyethylene is added up to about 150 parts by weight to withstand 100 parts by weight of the ACSM. Also, a mixed phase in which the ACSM phase is a continuous phase can be obtained.

(Regarding ACSM tan δ and vulcanization system)
Since the ACSM phase is required to have excellent sag resistance as described above, the sulfur content of the ACSM is 0.7% by weight or more as in the invention according to claim 4. And the temperature of the ACSM phase is 100 ° C and the frequency is 1
It is preferable that tan δ at 0 Hz is 0.09 or less.

For the same reason, as the vulcanization system, the rubber composition forming the ACSM phase is N, N'based on 100 parts by weight of ACSM as in the invention according to claim 5.
0.2 to 5.0 parts by weight of -m-phenylenedimaleimide and 0.
It is preferable that 1 to 4.0 parts by weight are blended.

Explaining tan δ, the complex elastic modulus in the dynamic property test (JIS K 6394) of vulcanized rubber is expressed by the following equation (1): G ^* = G ′ + iG ″ (1) G ^* : Complex shear modulus G ′: Storage modulus (real part of complex shear modulus) G ″: Loss modulus (imaginary part of complex shear modulus)

The angle δ, which represents the time delay between the applied stress and strain, is called the dissipation factor and is defined by the following equation (2). tan δ = G ″ / G ′ (2)

This tan δ is a damping term and is a measure of the ratio of the energy dissipated as heat to the maximum energy stored during one cycle of vibration. And
The loss elastic modulus G ″ is directly proportional to the heat dissipated per cycle as shown in the following equation (3). H = πG ″ γ ² (3) H: Heat dissipated per cycle γ: Maximum value of shear strain

As described above, tan δ represents the ease with which the mechanical energy applied to the rubber composition is dissipated as heat. If the value of tan δ is high, the mechanical energy applied from the outside It is advantageous to improve crack resistance because it reduces stress concentration due to heat, and if the value of tan δ is low, the amount of mechanical energy converted to heat is small, which is advantageous for improving sag resistance. Become.

Since the ACSM phase is intended to provide the belt with sag resistance, its tan δ is kept low as described above. From another point of view, it can be said that the halogenated polyethylene phase forms a high tan δ phase.

From the viewpoint of suppressing the above settling, the ACSM phase has a ta value at a temperature of 100 ° C. and a frequency of 10 Hz.
The upper limit of n δ is preferably 0.09, and more preferably 0.08. As for the lower limit of tan δ, if the value is too low, the problem of the above-mentioned cracking will occur, so it is preferable to set it to about 0.05.

Here, the value of tan δ is set to a temperature of 100 ° C.,
The frequency of 10 Hz is set because the operating environment and conditions of a general transmission belt (for example, a timing belt of an automobile) are taken into consideration. Especially, regarding the frequency, the transmission belt is bent by passing through a pulley. This is in consideration of the extended cycle.

(Regarding Sulfur Content and Chlorine Content) The sulfur content is closely related to the amount of chlorosulfone groups in the molecule, that is, the number of crosslinking points. The larger the amount, the denser the crosslinking. Therefore, the sulfur content is a major factor in changing the tan δ of the ACSM phase.

In the invention according to claim 4, the lower limit of the sulfur content of the ACSM forming the ACSM phase is 0.7% by weight.
The reason for this is that if the sulfur content is less than this, the value of tan δ becomes high and it becomes difficult to set tan δ at a low value. On the other hand, the upper limit of the sulfur content is preferably about 2.0% by weight, and if the sulfur content is higher than this, it will be advantageous for lowering the tan δ, but the addition of other compounding agents will be advantageous. Design becomes difficult.

As described above, the value of tan δ changes depending on the sulfur content, but not only the sulfur content but also the chlorine content is a factor of change. However, this chlorine content is
It has a closer relationship with the crystallinity of SM, and the higher the chlorine content, the stronger its rubber elastic properties, but the worse the low temperature properties. Therefore, regarding this chlorine content,
It is suitable to set it to 5 to 35% by weight, and more desirably to 25 to 32% by weight. That is, when the upper limit of the chlorine content is set to 35% by weight, and more preferably 32% by weight, the cohesive energy of chlorine can be suppressed to a low level, which is advantageous in preventing the rubber from curing and the cold resistance of the belt. Is improved. Also, the lower limit of the chlorine content is 15% by weight,
More preferably, it is set to 25% by weight, which is advantageous in ensuring the oil resistance and mechanical strength of the rubber.

However, it should be noted that even the power transmission belt described in Japanese Patent Laid-Open No. 4-212748 mentioned above as the prior art has the ACSM used for this.
Although the sulfur content and chlorine content of tan δ are specified, the value of tan δ cannot be specified only by this sulfur and chlorine content.

That is, the value of tan δ is not only determined by the above-mentioned sulfur content and chlorine content, but also changes by the kind and amount of the crosslinking agent and other compounding agents.

For example, the tan δ can be set to a predetermined high value by reducing the blending amount of the crosslinking agent and the crosslinking accelerator, but the tan δ can be increased by increasing the blending amount of carbon black or the process oil. δ can be set to a high value. However, if these amounts are changed, other rubber physical properties of the belt change accordingly,
It is necessary to adjust the amount of each compounding agent in consideration of various rubber physical properties required for the belt.

(Regarding compounding agent) The rubber composition forming the above mixed phase contains the crosslinking agent, the crosslinking accelerator, the carbon black, etc., as described above in relation to the description of tan δ. A general rubber compound such as a reinforcing agent, a filler, an acid acceptor, a plasticizer, a tackifier, a processing aid, an antioxidant and an activator can be arbitrarily selected and compounded.

As for the cross-linking compounding agent, as in the invention according to claim 5, N, N is added to 100 parts by weight of ACSM.
0.2-5.0 parts by weight of ‘-m-phenylene dimaleimide, and dipentamethylene thiuram tetrasulfide of 0.
It is preferable that 1 to 4.0 parts by weight are blended.

In the above rubber composition, N, N'-m-
Phenylene dimaleimide acts as a cross-linking agent, and if the compounding amount is less than 0.2 parts by weight, vulcanization becomes insufficient. on the other hand,
When this amount exceeds 5.0 parts by weight, the value of tan δ becomes low, but the problem of cracking occurs. Therefore, the compounding amount is set in the above range, and in order to set tan δ to a predetermined low value while performing appropriate vulcanization, the compounding amount may be 2 to 4 parts by weight. It is more preferable.

The above-mentioned dipentamethylene thiuram tetrasulfide is an accelerator for promoting cross-linking when used in combination with the above N, N'-m-phenylene dimaleimide. However, if it exceeds 4 parts by weight, tan δ will be considerably low, and the problem of cracking will occur. Therefore, the compounding amount of this accelerator is set within the above range, and a more preferable range is 1 to 2 parts by weight.

As carbon black, MAF, FE
F, GPF, SRF, etc., magnesium oxide, calcium hydroxide, magnesium oxide-aluminum oxide solid solution etc. as acid acceptors, process oil as softeners,
Dioctyl adipate (DOA), dioctyl sepacate (DOS), polyether plasticizer, etc., coumaron resin, phenol resin, alkylphenol resin etc. as tackifier, nickel butyl dithiocarbamate (NBC) as anti-aging agent , 2,2,4-trimethyl-
1,2-dihydroquinoline condensate (TMDQ), 6
-Ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline condensate (ETMDQ) and the like can be used, respectively.

When a magnesium oxide-aluminum oxide solid solution is used as the above acid acceptor, the blending amount is ACS.
1 to 50 parts by weight, preferably 4 to 100 parts by weight of M
-20 parts by weight. If the amount of this magnesium oxide-aluminum oxide solid solution is less than 1 part by weight, hydrogen chloride generated during crosslinking cannot be sufficiently removed, so that the crosslinking points of ACSM are reduced and a predetermined vulcanized product is obtained. If the amount exceeds 50 parts by weight, the Mooney viscosity becomes extremely high, which causes a problem in processing and finishing.

As a method for mixing the ACSM, the halogenated polyethylene and the compounding agent, kneading can be carried out by an appropriate known means and method (for example, using a Banbury mixer, a kneader or the like).

According to a sixth aspect of the present invention, in the power transmission belt according to any one of the first to fifth aspects, an adhesive rubber layer for holding the core wire extending in the belt longitudinal direction at an appropriate position and a compression layer. And a rubber layer, and a part of the element of the belt is a compressed rubber layer.

In the invention according to claim 7, in the power transmission belt according to claim 6, short fibers are mixed in the compressed rubber layer.

In the invention according to claim 8, the transmission belt described in claim 7 is a low edge type V belt, and in the invention according to claim 9, the transmission belt described in claim 7 is used. It is a low edge type V-ribbed belt.

In the invention according to claim 6 described above, the reason why some of the elements of the belt are limited to the compression rubber layer is that the compression rubber layer is required to have both sag resistance and crack resistance. Because.

Regarding the above-mentioned core wire, polyester fiber,
It can be formed by a cord having high strength and low elongation made of aramid fiber, glass fiber or the like. This core wire can be treated with an adhesive for the purpose of improving the adhesiveness with the adhesive rubber layer. As such an adhesive treatment, fibers are resorcin-formalin-latex (RF
It is general that the adhesive layer is uniformly formed on the surface by heating and drying after dipping in the L liquid).

On the other hand, the adhesive rubber layer has a chloroprene rubber composition which has heat resistance and adheres well to the above-mentioned core wire, a hydrogenated nitrile rubber composition having a hydrogenation rate of 80% or more, and an ACS.
M composition, CSM composition and the like can be used.

In the invention according to claim 7, since short fibers are mixed in the compressed rubber layer, it is advantageous in preventing cracks and settling. It is preferable to orient the short fibers in a direction perpendicular to the friction surface with the pulley in order to enhance the lateral pressure resistance of the compressed rubber layer. As the short fibers, organic fibers or inorganic fibers such as polyester fibers, nylon fibers and aramid fibers can be used.

In the inventions of claims 8 and 9,
The transmission belt is limited to the low edge type,
This is because in this type, the problem of sagging due to heat generation / accumulation of the compressed rubber layer and the problem of cracking become significant.

Further, the transmission belt according to the present invention is not limited to the low edge type V belt or the V ribbed belt, and may be another transmission belt such as a flat belt. A wrapped type belt covering the entire circumference may be used.

[0053]

BEST MODE FOR CARRYING OUT THE INVENTION

<Preferred Embodiment of Belt Structure> FIG. 1 shows a V-belt 1 as an example of a transmission belt. This V
The belt 1 includes three layers of rubber-coated canvas 2 on the upper surface, an adhesive rubber layer 4 on which a core wire 3 having high strength and low elongation is arranged, a compression rubber layer 5 as an elastic layer, and a rubber-coated canvas 2 on the lower surface. Is a lower edge type in which the side surfaces of these laminated members are exposed. Single fibers 6, 6, ... Are mixed in the compressed rubber layer 5 while being oriented in the belt width direction.

FIG. 2 shows a V-ribbed belt 8 as another example of the transmission belt. This V-ribbed belt 8
Is a two-layered rubber cloth 2 on the upper surface, an adhesive rubber layer 4 on which a core wire 3 having high strength and low elongation is arranged, and a compression rubber layer 5 which is an elastic body layer, which are laminated one above the other, and These are low edge types in which the side surfaces of these laminated members are exposed.
The compressed rubber layer 5 has a plurality of ribs 7, and the short fibers 6,
6, are mixed while being oriented in the belt width direction.

<Mixed Phase of ACSM Phase and Halogenated Polyethylene Phase> A case where the above-mentioned compressed rubber layer is formed by a mixed phase of ACSM phase and halogenated polyethylene phase will be described.

The α to η ACSSs having different sulfur contents shown in Table 1 and the chlorinated polyethylenes A to C having different crystallinity (hereinafter referred to as PE-CL) shown in Table 2 were prepared. did. The Mooney viscosity of each ACSM of the above α to η is shown in the lower column of Table 1.

[0057]

[Table 1]

[0058]

[Table 2]

An unvulcanized rubber sheet containing short fibers was produced by combining and kneading ACSM appropriately selected from Table 1 above and PE-CL selected from Table 2 together with α.
For each ACSM of ˜η, a short fiber-containing unvulcanized rubber sheet is produced independently, and the compression rubber layers shown in Table 3 having different constitutions 1 to 10 and 1 to 6 Each test belt (having the same structure as the V belt in FIG. 1) was produced. The tan δ value in Table 3 is the value of tan δ when vulcanized with a composition excluding chlorinated polyethylene from the rubber composition constituting the compressed rubber layer (test piece temperature 100 ° C., frequency 10 Hz according to JIS K 6394). I asked.)
Also, ACSM for making the above-mentioned unvulcanized rubber sheet
The composition of the composition is as follows.

ACSM 100 parts by weight Carbon black 45 parts by weight MgO 5 parts by weight Processing aid 2 parts by weight Anti-aging agent 2 parts by weight Plasticizer 10 parts by weight N, N'-m-phenylenedimaleimide 2 parts by weight dipentamethylene thiuram Tetrasulfide 1 part by weight Chlorinated polyethylene Variable

In the production of each of the unvulcanized rubber sheets, the composition of each compound and a predetermined amount of 6,6-nylon short fibers (length 3 mm) were kneaded by a closed type kneader to form a sheet. The method of forming into The mixing amount of the above short fibers is 2 with respect to 100 parts by weight of ACSM.
It was made to be 0 weight part.

In the production of the test belt, a mold mantle for forming the belt is provided with an upper canvas with rubber, an unvulcanized rubber sheet for an adhesive rubber layer, a core wire, an unvulcanized rubber sheet for an adhesive rubber layer, and a compressed rubber. The unvulcanized rubber sheet for layers and the lower canvas with rubber were wound in order and vulcanized at 160 ° C. for 40 minutes in a vulcanizing can. Then, the molded product that was released from the mold was cut into round pieces and further finished into a V shape.

Further, regarding the above-mentioned test belt, a core made of polyester fiber was used. This core wire was impregnated with an adhesive solution obtained by dissolving an isocyanate compound in a solvent, heated and dried, and then coated with an RFL solution and heated and dried. The RFL solution was 430.5 parts by weight of RF solution (resorcin-formalin solution), 787.4 parts by weight of 2.3-dichlorobutadiene, 716.4 parts by weight of water,
And wetting agent (sodium dioctyl sulfosuccinate 2
%) 65.8 parts by weight. As the rubber material of the adhesive rubber layer, 100 parts by weight of ACSM, 40 parts by weight of carbon black, 2 parts by weight of antioxidant, 2 parts by weight of accelerator, 8 parts by weight of MgO—Al ₂ O ₃ solid solution, and N—N ′.
ACS consisting of 1 part by weight of -m-phenylene dimaleimide
The M composition was used.

The constitution of the above-mentioned sample belt is an example and should not be construed as limiting the present invention.

In the belt running life test, as shown in FIG. 3, the test V-belt 20 is wound around the driving pulley 21, the driven pulley 22 and the idle pulley 23, and the belt 20 is run under the following conditions to be compressed. Time until the transmission failure occurs due to cracking or sag in the rubber layer (unit:
hr) is measured.

-Belt running test conditions-Diameter of drive pulley 21; 125 mm Diameter of driven pulley 22; 125 mm Diameter of idle pulley 23; 65 mm Winding angle θ of sample belt 20; 90 degrees Load W; 80 kgf Ambient temperature; 25 ℃ Drive pulley 21 rotation speed: 4800 rpm load: 10 PS

The test results are shown in Table 3.

[Table 3]

First, in the ratios 1 to 4, the life is short due to cracks or settling. The reason is that the ratio 2 to ratio 4 in which cracks are generated is low in tan δ, and the ratio 1 in which the value of tan δ is relatively high causes settling.

Examples 1 to 4 are examples in which the sulfur content of ACSM is different. The longer the sulfur content and the lower the tan δ, the longer the life. Therefore, as in Examples 2 to 4, the sulfur content of ACSM is 0.75% by weight or more, and tan δ is 0.0
It can be said that it is preferable that it is 9 or less.

Examples 4 to 6 are examples in which the crystallinity of PE-CL is different. The lower the crystallinity, the longer the life. Therefore, it can be said that non-crystalline or semi-crystalline PE-CL such as Ex 4 and Ex 5 is preferable.

Actual 4, actual 7 to actual 10, ratio 5 and ratio 6 are AC
In this example, the mixing ratio of SM and PE-CL is different. PE
If the proportion of -CL increases, cracks are prevented and the life becomes longer, but if the proportion becomes too large, the life becomes short due to fatigue. Therefore, from these results, the mixing ratios are as follows:
It can be said that PE-CL is preferably in the range of 10 to 100 parts by weight with respect to parts by weight.

[0072]

According to the invention described in claim 1, at least a part of the elements of the belt has an A containing ACSM as a rubber component.
Since it is formed by a mixed phase of a CSM phase and a phase containing a halogenated polyethylene as a rubber component, it is possible to enhance the heat resistance of the belt element while simultaneously improving the sag resistance and the crack resistance. be able to.

According to the invention of claim 2, in the transmission belt according to claim 1, the ACSM is used.
Since the phases form a continuous phase, it is advantageous in increasing the sag resistance of the element.

According to the invention of claim 3, in the power transmission belt according to claim 1 or 2, the proportion of the halogenated polyethylene is 10 to 100 parts by weight based on 100 parts by weight of the ACSM. In that case, the phase separation between the ACSM phase and the halogenated polyethylene phase becomes appropriate, which is advantageous for improving the sag resistance and crack resistance.

According to the invention of claim 4, in the transmission belt according to any one of claims 1 to 3, the sulfur content of the ACSM is 0.7% by weight.
As described above, the temperature of the ACSM phase is 100 ° C. and the frequency is 10
Since tan δ at Hz is set to 0.09 or less, it is advantageous in ensuring the sag resistance of the element.

According to the invention of claim 5, in the power transmission belt according to any one of claims 1 to 4, the rubber composition forming the ACSM phase is added.
Since 0.2 to 5.0 parts by weight of N, N'-m-phenylene dimaleimide and 0.1 to 4.0 parts by weight of dibentamethylene thiuram tetrasulfide were blended with 100 parts by weight of ACSM. It is possible to improve the sag resistance and the crack resistance by forming the ACSM phase and the halogenated polyethylene phase without causing insufficient vulcanization of the rubber.

According to the invention of claim 6, in the transmission belt according to any one of claims 1 to 5, an adhesive rubber layer for holding the core wire extending in the belt longitudinal direction at an appropriate position. And a compression rubber layer, and a part of the element of the belt is a compression rubber layer, it is possible to improve both the sag resistance and the crack resistance of the compression rubber layer.

According to the invention of claim 7, in the transmission belt according to claim 6, short fibers are mixed in the compression rubber layer, and therefore the sag resistance and the compression rubber layer of the compression rubber layer are reduced. It is advantageous for improving crack resistance.

According to the invention of claim 8 or the invention of claim 9, since the transmission belt described in claim 7 is a low edge type V-belt or a low edge type V-ribbed belt, these belts are used. It is possible to improve both the settling resistance and the crack resistance of the compressed rubber layer and extend its life.

[Brief description of drawings]

FIG. 1 is a sectional view of a V-belt according to an embodiment.

FIG. 2 is a sectional view of a V-ribbed belt according to an embodiment.

FIG. 3 is a front view showing a mode of a running life test of a transmission belt.

[Explanation of symbols]

 1 V-belt 3 Core wire 4 Adhesive rubber layer 5 Compressed rubber layer 6 Short fibers 7 Rib 8 V-ribbed belt 20 Test belt 21 Drive pulley 22 Driven pulley 23 Idle pulley

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // B29K 9:00

Claims (9)

[Claims] 1. At least some elements of the belt are formed by a mixed phase of an ACSM phase containing alkylated chlorosulfonated polyethylene as a rubber component and a phase containing halogenated polyethylene as a rubber component. And a transmission belt. 2. The transmission belt according to claim 1, wherein the ACSM phase forms a continuous phase. 3. The transmission belt according to claim 1, wherein the halogenated polyethylene is 10 to 1 with respect to 100 parts by weight of the alkylated chlorosulfonated polyethylene.
A transmission belt characterized by being mixed in a proportion of 00 parts by weight. 4. The transmission belt according to claim 1, wherein the alkylated chlorosulfonated polyethylene has a sulfur content of 0.7% by weight or more, and the ACSM phase. And a tan δ at a temperature of 100 ° C. and a frequency of 10 Hz of 0.09 or less. 5. The power transmission belt according to any one of claims 1 to 4, wherein the rubber composition forming the mixed phase is N, with respect to 100 parts by weight of alkylated chlorosulfonated polyethylene. N '
0.2 to 5.0 parts by weight of -m-phenylene dimaleimide, and 0.2% by weight of dipentamethylene thiuram tetrasulfide.
A power transmission belt characterized by being compounded in an amount of 1 to 4.0 parts by weight. 6. The power transmission belt according to claim 1, further comprising an adhesive rubber layer and a compression rubber layer for holding a core wire extending in a belt longitudinal direction at an appropriate position. A transmission belt, wherein a part of the elements of the belt is a compressed rubber layer. 7. The transmission belt according to claim 6, wherein short fibers are mixed in the compressed rubber layer. 8. The transmission belt according to claim 7, which is a V-belt of a low edge type. 9. The transmission belt according to claim 7 is a low edge type V-ribbed belt.