JP2009063114A - Transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission belt, with excellent wear resistance and heat durability. <P>SOLUTION: The transmission belt comprises rubber composition comprising short fibers composite with rubber. For the short fibers, 95 mol% or more of repeating units are composed of polyketone represented by formula (1), and they are RFL-treated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transmission belt, and more particularly to a transmission belt having excellent wear resistance and heat durability.

  The present applicant previously proposed in Patent Document 1 that short fibers and long fibers of fibers composed of polyketone (hereinafter referred to as polyketone fibers) are useful as rubber reinforcing materials such as belts. There has been no study on the demand for improvement in wear resistance and heat durability of the belt.

JP 2005-105470 A

  The present invention provides a transmission belt that meets such requirements.

（２）短繊維が、繊維長が０．５〜１０ｍｍ、繊維長Ｌと繊維径Ｄの比Ｌ／Ｄが３０〜１６７０の短繊維であることを特徴とする上記（１）に記載の伝動用ベルト。 The inventor of the present invention has arrived at the present invention as a result of intensive studies to solve the above problems.
That is, the present invention is as follows.
(1) A power transmission belt using a rubber composition in which short fibers and rubber are combined, wherein the short fibers are composed of a polyketone represented by the following formula (1) with 95 mol% or more of the repeating units. A transmission belt characterized by being made of fiber and RFL-treated.

(2) The transmission according to (1) above, wherein the short fiber is a short fiber having a fiber length of 0.5 to 10 mm and a ratio L / D of the fiber length L to the fiber diameter D of 30 to 1670. Belt.

  According to the present invention, it is possible to provide a transmission belt that is particularly excellent in wear resistance and heat durability.

但し式中、Ｒは、エチレン以外の炭素数１〜３０の有機基であり、例えば、プロピレン、ブチレン、１−フェニルエチレン等の基であり、Ｒの水素原子の一部または全部が、ハロゲン基、エステル基、アミド基、水酸基、エーテル基で置換されていてもよい。もちろん、Ｒは二種以上であってもよく、例えば、プロピレン基と１−フェニルエチレン基が混在していてもよい。 The present invention will be specifically described below.
In the polyketone constituting the polyketone fiber of the present invention, 95 mol% or more, preferably 98 mol% or more, particularly 99.6 mol% or more of the repeating unit is represented by the above formula (1), and 5 mol%. Within a range of less than the above, repeating units other than the above formula (1), for example, those represented by the following formula (2) may be contained.

In the formula, R is an organic group having 1 to 30 carbon atoms other than ethylene, for example, a group such as propylene, butylene, 1-phenylethylene, etc., and a part or all of the hydrogen atoms of R are halogen groups. , An ester group, an amide group, a hydroxyl group, and an ether group may be substituted. Of course, R may be two or more, for example, a propylene group and a 1-phenylethylene group may be mixed.

式中のｔ及びＴは、それぞれヘキサフルオロイソプロパノール（セントラル硝子（株）社製）及び該ヘキサフルオロイソプロパノールに溶解したポリケトンの希釈溶液の２５℃での粘度管の流過時間である。Ｃは、上記希釈溶液の濃度であり、ヘキサフルオロイソプロパノール１００ｍｌ中のポリケトンの質量（ｇ）である。
ポリケトンには、必要に応じて、酸化防止剤、ラジカル抑制剤、他のポリマー、艶消し剤、紫外線吸収剤、難燃剤、金属石鹸等の添加剤を含有させてもよい。 The intrinsic viscosity [η] of the polyketone is preferably 1 dl / g or more, more preferably 2 dl / g or more, particularly preferably 4 dl / g or more, preferably 20 dl / g or less, more preferably 15 dl / g or less, particularly Preferably it is 10 dl / g or less.
The intrinsic viscosity [η] is a value obtained based on the following definition formula.

In the formula, t and T are the flow times of the viscosity tube at 25 ° C. of hexafluoroisopropanol (manufactured by Central Glass Co., Ltd.) and a dilute solution of polyketone dissolved in the hexafluoroisopropanol, respectively. C is the concentration of the diluted solution, and is the mass (g) of polyketone in 100 ml of hexafluoroisopropanol.
The polyketone may contain additives such as antioxidants, radical inhibitors, other polymers, matting agents, ultraviolet absorbers, flame retardants, and metal soaps as necessary.

Next, as preferable characteristics of the polyketone fiber, the tensile strength is 10 cN / dtex or more, particularly preferably 15 cN / dtex or more, 30 cN / dtex or less, and the tensile elongation is 3% or more, more preferably 3.5. % Or more, particularly preferably 4% or more, 15% or less, more preferably 10% or less, further preferably 8% or less, particularly preferably 6% or less, and the tensile elastic modulus is 100 cN / dtex or more, more preferably Is 200 cN / dtex or more, particularly preferably 300 cN / dtex or more, and 1000 cN / dtex or less.
The form of the polyketone fiber is a short fiber, which may be uniform or thick in the length direction, and the cross-sectional shape of the fiber is round, triangular, L-shaped, T-shaped, Y-shaped, W-shaped, Many types such as Yaba type, flat type (flatness of about 1.3-4, W type, I type, boomerang type, wave type, skewer type, eyebrows type, rectangular parallelepiped type, etc.), dogbone type, etc. A square shape, a multi-leaf shape, a hollow shape, an irregular shape, or the like may be used.

The present invention is a transmission belt using a rubber composition in which short fibers of such polyketone fibers and rubber are combined, wherein the short fibers are RFL-treated. By using the polyketone short fibers thus obtained, the heat durability is greatly improved.
The RFL treatment refers to treatment with a mixed solution containing resorcin, formalin and latex, and the preferable adhesion amount of the RFL resin is preferably 1 to 10% by mass, particularly preferably 2 to 7% by mass with respect to the fiber.
A preferred molar ratio (F / R) of formalin (F) to resorcin (R) is 1.0 to 2.2, particularly preferably 1.0 to 1.9, and resorcin to the solid content mass (L) of the total latex. And the ratio (RF / L) of the formalin total mass (RF) is preferably 5 to 25% by mass, particularly preferably 5 to 17% by mass, and the molar ratio of the total amount of sodium hydroxide and ammonium hydroxide to resorcin (R) (NaOH + NH ₄ OH / R) is preferably 0.21 or less.

The latex is preferably a latex corresponding to the composite rubber, such as styrene-butadiene-vinylpyridine terpolymer, chlorosulfonated polyethylene (CSM), alkylated chlorosulfonated polyethylene (ACSM), hydrogenated acrylonitrile rubber. Examples thereof include latex such as (HNBR), epichlorohydrin, natural rubber, styrene / butadiene rubber (SBR), chloroprene rubber, olefin-vinyl ester copolymer, and ethylene-propylene-diene rubber (EPDM).
Prior to the RFL treatment, pretreatment with an epoxy or isocyanate compound may be performed.
As a method of RFL treatment, short fibers of polyketone fibers may be applied. Preferably, however, the long fibers of polyketone fibers are subjected to RFL treatment in a state where they are twisted as necessary, and then cut to obtain short fibers. The number of twists is preferably a sweet twist of 100 to 700 in terms of a twist coefficient (K1) represented by the following formula, but may be a medium twist to a strong twist of about 30000.
T1 = K1 / D ^1/2
T1 = Number of twists (T / m), D = Fine fineness (dtex) of the yarn supplied for RFL

In the present invention, the fiber length of the polyketone short fiber is preferably 0.5 to 10 mm, preferably 1 mm or more, more preferably 1.5 mm or more, particularly preferably 2 mm or more, 9 mm or less, more preferably 8 mm or less, particularly preferably. Is 7 mm or less. If the fiber length is less than 0.5 mm or more than 10 mm, sufficient wear resistance may not be obtained.
The ratio L / D of the preferred fiber length L to the fiber diameter D is 30 or more, more preferably 50 or more, particularly preferably 100 or more, 1670 or less, more preferably 1500 or less, and particularly preferably 1000 or less. . If it is less than 30 or exceeds 1670, sufficient wear resistance may not be obtained.
A preferable single yarn fineness is 0.01 to 10 dtex, more preferably 0.1 to 10 dtex, and particularly preferably 0.5 to 5 dtex.

The preferable content of the polyketone short fiber in the rubber composition is 3 to 50 parts by mass, more preferably 5 to 40 parts by mass, particularly preferably 5 to 30 parts by mass, and 3 parts by mass per 100 parts by mass of the rubber. If it is less than 50 parts, sufficient wear resistance and heat durability may not be obtained, and if it exceeds 50 parts by mass, the processability of rubber may be difficult.
In the present invention, the fiber combined with rubber is preferably 100% polyketone short fiber, but if necessary, it is 70% or less (ratio to the total amount of combined fiber), more preferably 50%. In the following, fibers other than polyketone short fibers may be used within a range of 30% or less, and polyester fibers, polyamide fibers, acrylic fibers, glass fibers, wholly aromatic polyester fibers, polyphenylene sulfide fibers, polyimide fibers, aramid fibers ( Para- or meta-), polyvinyl alcohol fiber, poly (p-phenylenebenzobisoxazole) fiber, ultra-high molecular weight polyolefin fiber or the like may be mixed.

  Next, examples of rubber include chloroprene rubber, natural rubber, nitrile rubber, styrene / butadiene rubber, butadiene rubber, ethylene / propylene rubber, chlorosulfonated polyethylene rubber (CSM), and alkylated chlorosulfonated polyethylene rubber (ACSM). , Acrylic rubber, urethane rubber, hydrogenated acrylonitrile rubber (HNBR), a composition mainly composed of ethylene-α-olefin elastomer, such as ethylene-propylene-diene rubber (EPDM), ethylene-propylene copolymer (EPM), ethylene -Butene copolymer (EBM), ethylene-octene copolymer (EOM), halogen substitution (especially chlorine substitution), mixtures of two or more thereof. The composition mainly composed of an ethylene-α-olefin elastomer may contain a hydrogenated acrylonitrile rubber (HNBR), and if necessary, an enhancer such as carbon black or silica, or a filler such as calcium carbonate or talc. , Plasticizers, stabilizers, processing aids, colorants and the like.

In the present invention, a V-belt, a flat belt, and a toothed belt are preferable as the transmission belt, and a V-ribbed belt, a low-edge type V-belt, and a wrapped type V-belt are preferable. Moreover, the friction transmission belt which has a compression rubber layer using the rubber composition of this invention may be sufficient, and also a friction transmission belt may have an adhesive rubber layer. For example, it is composed of a compressed rubber layer, an adhesive rubber layer in contact with the compressed rubber layer, and an upper canvas layer in contact with the adhesive rubber layer, and a core wire is embedded in the adhesive rubber layer along the longitudinal direction of the belt There is.
Here, the rubber for forming the compression rubber layer and the rubber for forming the adhesive rubber layer may be the same, or the adhesive rubber layer may contain polyketone short fibers, What is necessary is just to select suitably content per 100 mass parts of rubber | gum according to the case where it is set as the length direction of a belt, or the width direction of a belt as a calendar row direction.
As the upper canvas layer, for example, a fabric using polyketone fibers in addition to cotton, polyamide, polyester, and aramid fibers can be used. As the core wire, for example, polyketone core wire can be used in addition to polyester (polyethylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon 6, 66, etc.), polyvinyl alcohol, and aramid core wire.

The power transmission belt of the present invention can be manufactured by a conventionally known manufacturing method. For example, in the case of a V-ribbed belt, a rubber coated canvas and a rubber composition unvulcanized sheet for an adhesive rubber layer are wound around the peripheral surface of a molding drum. And then spinning the core wire thereon, and further wrapping the rubber composition unvulcanized sheet for the adhesive rubber layer on it, and then wrapping the rubber composition unvulcanized sheet for the compression rubber layer A laminate is used. Then, a ring obtained by vulcanizing this laminate may be formed with ribs on the surface with a cutting grindstone and cut into a predetermined width.
For example, when there is a concern about the decrease in the tensile strength of polyketone fiber due to strong UV rays outdoors, UV absorbers (for example, one or more of benzophenone-based, benzotriazole-based, hindered amine-based in the form of fiber) And / or an ultraviolet shielding agent (for example, fine particles such as titanium oxide, iron oxide, cerium oxide, etc., preferably having an average particle size of 0.01 to 0.6 μm). . Examples of the method of inclusion include a method of applying or coating a fiber or a resin or film containing an ultraviolet absorber and / or an ultraviolet shielding agent on the fiber. The content of the ultraviolet absorber and / or the ultraviolet shielding agent is a resin. And 0.001 to 10% by mass relative to the mass of the film.

Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.
The measurement method and evaluation method in the present invention are as follows.
(1) Tensile strength, tensile elongation, tensile elastic modulus Measured according to JIS-L-1013.
Sample length: 20 cm, tensile speed: measured at 20 cm / min, and an average value is obtained when measured 20 times.

(2) Abrasion resistance and heat resistance (Abrasion resistance)
A rubber composition was prepared using a Banbury mixer at the following blending ratio and rolled with a calendar to obtain a 1.1 mm-thick unvulcanized rubber sheet. Five obtained unvulcanized rubber sheets were stacked and press vulcanized at 170 ° C. for 20 minutes to prepare a rectangular vulcanized rubber having a 5 mm × 5 mm wear surface.
A pin-on-disk wear test was conducted for 24 hours at a surface pressure of 1.2 MPa, a sliding speed of 0.15 m / s, and an ambient temperature of 100 ° C. with an FC material having a surface roughness (Rz) of 9.6 μm. The specific wear amount in a section of 10 to 20 hours was determined by the following formula.
Specific wear amount (10 ⁻⁶ mm ³ / Nm) = wear volume per unit time / (wear distance per unit time × load)

(Heat resistance durability)
According to a conventional method, a flat belt having a belt width of 10 mm and a thickness of 5 mm was prepared at the following blending ratio, and the crack generation time was measured by running between a pair of rotating pulleys. The flat belt was run under an atmospheric temperature of 90 ° C., a pulley rotational speed of 5500 rpm, and a tension of 85 kgf.
<Combination ratio>
HNBR 100 parts by mass Zinc oxide 5 parts by mass Sulfur 1 part by mass Carbon black 60 parts by mass Softening agent 5 parts by mass Anti-aging agent 4 parts by mass Vulcanization accelerator 2 parts by mass Example short fiber 10 parts by mass

[Example 1]
After twisting (10 T / m) a multifilament of polyketone fiber of 1670 dtex / 1250 f (manufactured by Asahi Kasei Fibers Co., Ltd .; trademark Cyvalon; tensile strength 18 cN / dtex, tensile elongation 5%, tensile elastic modulus 350 cN / dtex) Polyketone fibers were immersed in an RFL solution having the following composition, and after squeezing (pickup rate 5%), dried, and heat-treated at 200 ° C. for 3 minutes.
An RFL-treated polyketone fiber (RFL resin adhesion amount to the fiber of 3.5% by mass) was cut to a length of 3.5 mm and used as a short fiber for a rubber composition containing a polyketone short fiber. The L / D ratio of the short fiber used was 318.
As a result of evaluating the wear resistance and the heat resistance, the specific wear amount was 5.2 and the crack generation time was 410 hours, and both the wear resistance and the heat resistance were excellent.
<RFL solution>
Resorcinol 11 parts by weight Formalin (37%) 8 parts by weight Caustic soda 0.2 parts by weight Styrene / butadiene / vinylpyridine terpolymer (40%) 84 parts by weight Chlorsulfonated polyethylene rubber latex (40%) 56 parts by weight Water 121.5 parts by mass

[Comparative Example 1]
In Example 1, except that the RFL treatment was not performed, the results of evaluating the wear resistance and heat durability in the same manner as in Example 1 were as follows. The specific wear amount was 5.3 and the crack generation time was 350 hours. The properties were inferior to those of Example 1.

[Examples 2 to 7]
In Example 1, except that the polyketone short fiber having a changed L / D was used, the results of evaluating the wear resistance and heat durability in the same manner as in Example 1 showed that the specific wear was obtained at L / D = 30. When the amount is 5.4, crack generation time is 390 hours (Example 2), and L / D = 208, the specific wear amount is 5.2, crack generation time is 410 hours (Example 3), and L / D = 611, the specific wear. When the amount is 5.2, the crack generation time is 420 hours (Example 4), and L / D = 1670, the specific wear amount is 5.4 and the crack generation time is 400 hours (Example 5). It was excellent in both sex.
On the other hand, when L / D = 18, the specific wear amount is 5.5 and crack generation time is 380 hours (Example 6), and when L / D = 2000, the specific wear amount is 5.6 and crack generation time is 380 hours (Example 7). In particular, the wear resistance tended to be inferior to that of Examples 1-5.

  The present invention relates to a transmission belt that is particularly excellent in wear resistance and heat resistance durability, and in particular, a V belt, a flat belt, and a toothed belt are suitable. A belt and a wrapped type V belt are preferable.

Claims (2)

A transmission belt using a rubber composition in which short fibers and rubber are combined, wherein the short fibers are fibers composed of polyketone represented by the following formula (1) with 95% by mole or more of the repeating units. A transmission belt characterized by being subjected to RFL treatment.

  The transmission belt according to claim 1, wherein the short fibers are short fibers having a fiber length of 0.5 to 10 mm and a ratio L / D of the fiber length L to the fiber diameter D of 30 to 1670.