阅读说明：本技术 传动带 (Transmission belt ) 是由 土屋大树 小林正吾 松尾圭一郎 橘博之 于 2018-04-19 设计创作，主要内容包括：传动带至少包括底部橡胶层(11)。构成底部橡胶层(11)的橡胶组合物含有橡胶成分、纤维素微细纤维及短纤维。纤维素微细纤维的平均直径为1nm以上且200nm以下,并且相对于橡胶成分100质量份,该纤维素微细纤维的添加量为0.5质量份以上。短纤维的平均直径为5μm以上且30μm以下,并且相对于橡胶成分100质量份,该短纤维的添加量为1质量份以上。(The drive belt comprises at least a base rubber layer (11). The rubber composition constituting the bottom rubber layer (11) contains a rubber component, cellulose microfibers, and short fibers. The cellulose microfine fibers have an average diameter of 1nm to 200nm, and are added in an amount of 0.5 parts by mass or more per 100 parts by mass of the rubber component. The short fibers have an average diameter of 5 to 30 [ mu ] m, and are added in an amount of 1 part by mass or more per 100 parts by mass of the rubber component.)

1. A power transmission belt comprising at least a base rubber layer, the power transmission belt characterized by:

the rubber composition constituting the bottom rubber layer contains a rubber component, cellulose microfibers and short fibers,

the cellulose microfine fibers have an average diameter of 1nm to 200nm and are added in an amount of 0.5 part by mass or more per 100 parts by mass of the rubber component,

the short fibers have an average diameter of 5 to 30 [ mu ] m, and are added in an amount of 1 part by mass or more per 100 parts by mass of the rubber component.

2. The belt of claim 1, wherein:

the cellulose microfine fibers have an average diameter of 2-50 nm,

the short fibers have an average diameter of 8 to 25 [ mu ] m.

3. A transmission belt according to claim 1 or 2, wherein:

the amount of the cellulose microfine fibers added is in the range of 1 to 20 parts by mass based on 100 parts by mass of the rubber component,

the amount of the short fiber added is in the range of 5 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the rubber component.

4. A transmission belt according to any one of claims 1 to 3, wherein:

the cellulose microfiber is prepared by a chemical defibration method.

5. A transmission belt according to any one of claims 1 to 4, wherein:

the rubber comprises the following components: at least one rubber component selected from the group consisting of ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-octene copolymer, ethylene-butene copolymer, chloroprene rubber, chlorosulfonated polyethylene rubber, and hydrogenated nitrile rubber.

Technical Field

The present disclosure relates to a power transmission belt.

Background

Various substances are added to the rubber composition constituting the transmission belt in order to obtain target characteristics. For example, patent document 1 discloses a technique for forming at least a compression layer in a v-ribbed belt from a rubber composition containing carbon black and short fibers.

Patent document 1: japanese laid-open patent publication No. 2014-167347

Disclosure of Invention

Various requirements are imposed on various characteristics of a power transmission belt made of a rubber composition. The present disclosure describes a technique for improving the durability and transmission efficiency of a transmission belt made using a rubber composition.

The power transmission belt of the present disclosure includes at least a base rubber layer. The rubber composition constituting the bottom rubber layer contains a rubber component, cellulose microfibers, and short fibers. The cellulose microfine fibers have an average diameter of 1nm to 200nm, and are added in an amount of 0.5 parts by mass or more per 100 parts by mass of the rubber component. The short fibers have an average diameter of 5 to 30 [ mu ] m, and are added in an amount of 1 part by mass or more per 100 parts by mass of the rubber component.

Effects of the invention

According to the transmission belt of the present disclosure, durability and transmission efficiency of the transmission belt can be improved.

Drawings

Fig. 1 is a perspective view schematically illustrating a v-ribbed belt in an embodiment of the present disclosure;

fig. 2 is a sectional view of a main portion of the v-ribbed belt in the embodiment;

fig. 3 is a first explanatory view showing a manufacturing method of the v-ribbed belt in the embodiment;

fig. 4 is a second explanatory view showing a manufacturing method of the v-ribbed belt in the embodiment;

fig. 5 is a third explanatory view showing a manufacturing method of the v-ribbed belt in the embodiment;

fig. 6 is a fourth explanatory view showing a manufacturing method of the v-ribbed belt in the embodiment;

fig. 7 is a fifth explanatory view showing a manufacturing method of the v-ribbed belt in the embodiment;

fig. 8 is a sixth explanatory view showing a manufacturing method of the v-ribbed belt in the embodiment;

fig. 9 is a perspective view schematically showing a flat belt in the embodiment;

fig. 10 is a first explanatory view showing a manufacturing method of a flat belt in the embodiment;

fig. 11 is a second explanatory view showing a manufacturing method of a flat belt in the embodiment;

fig. 12 is a third explanatory view showing a method of manufacturing a flat belt in the embodiment;

FIG. 13 is a perspective view schematically illustrating a single-sided toothed V-belt in an embodiment;

FIG. 14 is a view schematically showing a wrapping cloth V belt, a trim V belt, and a timing belt in the embodiment;

FIG. 15 schematically illustrates a belt running test machine for measuring the transmission efficiency of a transmission belt;

fig. 16 schematically shows a belt running test machine for evaluating the wear resistance and bending fatigue of the belt.

Detailed Description

Next, embodiments of the present disclosure will be explained.

(rubber composition)

The rubber composition according to the present embodiment is a rubber composition in which an uncrosslinked rubber composition containing cellulose nanofibers (hereinafter, also referred to as "CNF") and short fibers is dispersed in a rubber component, and the rubber component is crosslinked by heating and pressurizing the uncrosslinked rubber composition. The content of CNF is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 20 parts by mass or less, more preferably 10 parts by mass or less, with respect to 100 parts by mass of the rubber component. The content of the short fiber is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and preferably 40 parts by mass or less, more preferably 30 parts by mass or less, per 100 parts by mass of the rubber component.

Examples of the rubber component include ethylene- α -olefin elastomers such as ethylene-propylene rubber (EPR), ethylene-propylene-diene rubber (EPDM), ethylene-octene copolymers, and ethylene-butene copolymers, Chloroprene Rubber (CR), chlorosulfonated polyethylene rubber (CSM), and hydrogenated nitrile rubber (H-NBR).

In the case of using CR as the rubber component, it is preferable that CR is a main component and the content of CR in the rubber component is more than 50 mass%. Further, from the viewpoint of suppressing heat generation and obtaining excellent abrasion resistance, the content of CR in the rubber component is preferably 80% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass.

Examples of CR include G-type sulfur-modified CR, W-type thiol-modified CR, A-type highly crystalline CR, low viscosity CR, and carboxylated CR. The CR contained in the rubber component preferably contains one or two or more of the above-mentioned CR, more preferably contains sulfur-modified CR, still more preferably contains sulfur-modified CR mainly, and still more preferably consists of only sulfur-modified CR, from the viewpoint of improving the power transmission efficiency and durability of the belt. Most preferably, the rubber component consists only of sulfur-modified CR.

CNF is composed of a skeletal component of plant cell walls obtained by breaking apart plant fibers very finely. As the raw material slurry of CNF, for example, slurry of wood, bamboo, pefurazone (straw), potato, sugar cane (bagasse), waterweed, seaweed, and the like is given. Among them, wood pulp is preferred.

Examples of CNF include TEMPO oxidation CNF and mechanical defibration CNF. The CNF preferably contains one or two of the above CNFs, preferably TEMPO-oxidized CNF as a main component, and more preferably consists of only TEMPO-oxidized CNF.

TEMPO oxidation CNF is CNF obtained by selectively oxidizing a hydroxyl group at C6 in a cellulose molecule to a carboxyl group by allowing a co-oxidant to act on cellulose contained in a raw material slurry with an N-oxyl compound as a catalyst, and mechanically refining the carboxyl group. Examples of the N-oxyl compound include radicals of 2,2,6, 6-tetramethylpiperidin-1-oxyl (TEMPO) and 4-acetamido-TEMPO. Examples of the co-oxidizing agent include hypohalous acids and salts thereof, perhalogenic acids and salts thereof, hydrogen peroxide, and perhydroorganic acids. The mechanical defibration CNF is a CNF obtained by pulverizing a raw material slurry by a defibrating apparatus such as a kneader such as a twin-screw kneader, a high-pressure homogenizer, a grinder, or a bead mill.

The fiber diameter of the TEMPO oxidized CNF is, for example, 1nm to 10nm, and the distribution is narrow. On the other hand, the fiber diameter of the mechanical defibration CNF is several tens nm to several hundreds nm, and the distribution thereof is wide. Therefore, it is possible to clearly distinguish between the TEMPO oxidized CNF and the mechanical defibered CNF according to the size of the fiber diameter and the distribution thereof.

The average fiber diameter of the CNF contained in the rubber composition in the present embodiment is preferably 1nm or more, more preferably 2nm or more, and preferably 200nm or less, more preferably 50nm or less, and further preferably 20nm or less.

The CNF may contain hydrophobized CNF that has been subjected to a hydrophobization treatment. Examples of the hydrophobized CNF include a CNF in which a part or all of carboxyl groups in cellulose are replaced with a hydrophobic group, and a CNF subjected to a hydrophobization surface treatment with a surface treatment agent. Examples of hydrophobization for obtaining CNF in which a part or all of the hydroxyl groups in cellulose are replaced with hydrophobic groups include esterification, alkylation, tosylation, epoxidation, and arylation. Among them, esterification is preferable. Specifically, the esterified hydrophobized CNF is a CNF obtained by acylating a part or all of hydroxyl groups in cellulose with a carboxylic acid such as acetic acid, acetic anhydride, propionic acid, or butyric acid, or a halide thereof. Examples of the surface treatment agent for obtaining the CNF subjected to the hydrophobic surface treatment with the surface treatment agent include a silane coupling agent.

Examples of the short fibers include: para-aramid staple fibers, meta-aramid staple fibers, nylon 6,6 staple fibers, nylon 4,6 staple fibers, polyethylene terephthalate staple fibers, polyethylene naphthalate staple fibers, and the like. The short fibers preferably contain one or more of the above short fibers, more preferably contain para-aramid short fibers, preferably contain para-aramid short fibers as a main component, and still more preferably consist of only para-aramid short fibers.

Examples of the para-aramid staple fibers include those of poly (p-phenylene terephthalamide) (e.g., Kevlar (Dupont) and Twaron (Derman)) and those of poly (p-phenylene-3, 4' -oxydiphenylterephthalamide) (e.g., Technia (Derman)). The para-aramid staple fibers preferably contain one or two of the above para-aramid staple fibers, more preferably a co-poly-p-phenylene-3, 4' -oxydiphenylterephthalamide-containing staple fiber, still more preferably a co-poly-p-phenylene-3, 4' -oxydiphenylterephthalamide-containing staple fiber as a main component, and still more preferably a co-poly-p-phenylene-3, 4' -oxydiphenylterephthalamide-containing staple fiber alone.

The staple fiber preferably has a fiber length of 0.5mm to 5.0mm, more preferably 1.0mm to 3.0 mm. The fiber diameter of the short fibers is preferably 5.0 μm or more, more preferably 8 μm or more, and preferably 30 μm or less, more preferably 25 μm or less.

A crosslinking agent for crosslinking CR is added to an uncrosslinked rubber composition forming the rubber composition according to the embodiment. Examples of the crosslinking agent include metal oxides such as zinc oxide and magnesium oxide. The crosslinking agent is preferably zinc oxide and magnesium oxide in combination. The amount of zinc oxide added is preferably 3 parts by mass or more and 7 parts by mass or less, and more preferably 4 parts by mass or more and 6 parts by mass or less, with respect to 100 parts by mass of the rubber component. The amount of magnesium oxide added is preferably 3 parts by mass or more and 7 parts by mass or less, and more preferably 4 parts by mass or more and 6 parts by mass or less, with respect to 100 parts by mass of the rubber component.