JPH07157166A - Roller and its manufacturing method - Google Patents

Abstract

(57) [Abstract] [Purpose] A roller that has excellent slidability with respect to a shaft, wear resistance and scratch resistance against objects to be conveyed such as paper, and can reduce the manufacturing cost because the manufacturing process can be simplified. [Structure] Cylindrical laminate characterized in that a bearing cylinder sliding part layer in contact with a shaft is made of polyacetal resin, and an outer peripheral part layer of the sliding part layer is made of a thermoplastic resin or a thermoplastic elastomer. Roller with structure. Preferably, an unsaturated carboxylic acid-modified polyolefin resin layer, an unsaturated epoxy-modified polyolefin resin layer or a polyurethane resin layer is provided as an adhesive layer between the sliding portion layer and the outer peripheral portion layer. The roller can be manufactured, for example, by extruding a rod-shaped material having a core portion made of a polyacetal resin and an outer peripheral layer made of a thermoplastic resin or a thermoplastic elastomer, and then cutting the core portion.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to rollers. More specifically, the bearing sleeve sliding part layer is made of polyacetal resin and has excellent slidability with respect to the shaft, and also has excellent abrasion resistance to objects to be conveyed such as paper, and simplifies the manufacturing process. The present invention relates to a roller that can reduce costs.

[0002]

2. Description of the Related Art For example, copiers, printers, OA equipment such as fax machines, and printing machines at printing factories are equipped with rollers for feeding paper. Taking such a paper feed roller as an example, among the constituent materials of the paper feed roller, a vulcanized rubber is usually used for the roller surface layer that comes into contact with the paper. In some cases, the vulcanized rubber part is directly fixed to the shaft, but in the roller that rotates with respect to the shaft, the bearing tube sliding part layer is provided in the center, and the shaft penetrates into it. The structure is such that The reason why vulcanized rubber is used in the surface layer of the paper feed roller is as follows.
It has a large friction coefficient with respect to paper, no slippage, excellent abrasion resistance with respect to paper, excellent sound absorption during paper feeding, and scratch resistance. On the other hand, for the shaft cylinder sliding part layer of the paper feed roller having the shaft cylinder sliding part layer, polyacetal resin which is oil-free and has good slidability is used. It is manufactured by fitting a vulcanized rubber cylinder to cover it, or by coating the sliding portion of the bearing cylinder in a cylindrical shape with unvulcanized rubber and then vulcanizing. Therefore, the bearing tube sliding portion layer is provided in the center,
In addition, the paper feed roller having the vulcanized rubber layer on the surface layer has excellent paper feed performance, but has a problem that the manufacturing process is complicated, including the vulcanization process, and the manufacturing cost is increased. The same problem occurs in the transport rollers other than the paper feed roller.

[0003]

Means for Solving the Problems The inventors of the present invention have made extensive studies in order to solve the above-mentioned problems in a roller using a polyacetal resin for a shaft sliding portion layer, and found that a specific resin or a thermoplastic elastomer was used. In the roller consisting of the outer peripheral layer and the polyacetal resin barrel sliding layer, the roller is excellent in abrasion resistance due to the conveyance of the object to be conveyed, and other necessary performance such as conveyance performance is within a range that can be sufficiently used. However, they have found that the manufacturing cost can be significantly reduced, and have completed the present invention.

That is, according to the present invention, the bearing tube sliding portion layer in contact with the shaft is made of polyacetal resin, and the outer peripheral portion layer of the sliding portion layer is made of thermoplastic resin or thermoplastic elastomer. And a roller having a tubular laminated structure. In this case, the thermoplastic elastomer is preferably a thermoplastic elastomer selected from the group consisting of olefin-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyamide-based thermoplastic elastomer and polyurethane-based thermoplastic elastomer, and sliding An unsaturated carboxylic acid-modified polyolefin resin layer, an unsaturated epoxy-modified polyolefin resin layer or a polyurethane resin layer is preferably provided as an adhesive layer between the partial layer and the outer peripheral layer.

Further, a rod-shaped member having a core made of polyacetal resin and an outer peripheral layer made of a thermoplastic resin or a thermoplastic elastomer is extruded, and then the core is cut to form a polyacetal resin bearing cylinder. There is provided a method of manufacturing a roller having the above structure, which comprises forming a sliding layer.

[0006]

The roller provided by the present invention has excellent sliding characteristics because the bearing cylinder sliding layer is made of polyacetal resin, and the outer peripheral layer is made of a specific resin or thermoplastic elastomer. , Excellent in abrasion resistance with respect to objects to be conveyed such as paper, and also in the range in which conveyance characteristics and scratch resistance can be sufficiently used, and a complicated process is not required for manufacturing rollers.

As the polyacetal resin used in the production of the roller of the present invention, both a polyacetal homopolymer and a polyacetal copolymer having a main chain composed mainly of oxymethylene chains can be used. Further, as long as the molding is possible, the polyacetal modified by crosslinking or graft copolymerization by a known method can be used as the base resin. The degree of polymerization is not particularly limited as long as it can be molded.

It is not necessary to add a lubricant as the polyacetal resin used in the present invention, but a lubricant may be added when it is necessary to further improve the slidability. In this case, as the lubricant, solid lubricants such as molybdenum disulfide and graphite, resins such as fluororesin, polyolefin resin, silicone resin, fatty acid ester, paraffin oil, spindle oil, lubricating oil such as silicone oil, etc. Can be illustrated.
When the polyacetal resin needs rigidity, a reinforcing material may be added. Examples of such a reinforcing material include potassium titanate whiskers and carbon fibers. These reinforcing materials may be used alone or in combination with other known reinforcing materials.

When the lubricant has poor compatibility or affinity with the polyacetal resin, a third component may be added as a lubricant retainer. For example, when a fatty acid ester is used as a lubricant, 1 to 1 of inorganic powder having an average particle size of 50 μm or less is added to the lubricant-containing polyacetal resin.
20 parts by weight (in composition), 0.05-
You may mix | blend 10 weight part (in composition). When a silicone polymer is used as a lubricant, 0.5 to 25 parts by weight (in the composition) of silica powder having the silicone polymer absorbed therein may be added. As the third component, other than the above, inorganic components such as activated carbon and graphite, high molecular weight polyethylene, ethylene copolymer, organic acid polymers such as silicone rubber and the like can be used.

The polyacetal resin used in the present invention may be added with various known stabilizers to enhance its stability. Further, it may be a mixture of various known additives. Examples of such additives include colorants such as dyes and pigments, antioxidants, heat-resistant agents, antistatic agents, ultraviolet absorbers, lubricants, release agents, plasticizers, crystal accelerators, crystal nucleating agents, etc. There is.

The material constituting the outer peripheral layer of the roller of the present invention is a thermoplastic resin or a thermoplastic elastomer, but the latter is preferable from the viewpoint of softness.
Examples of the former thermoplastic resin include polyolefin, polyester and polyamide. Here, examples of the polyolefin include polyethylene and polypropylene. Examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, and polyethylene isophthalate / terephthalate copolymers. As polyamide, nylon 6, nylon 66,
Examples thereof include nylon 610, nylon 9, nylon 11, nylon 12, nylon 6/66, nylon 66/610 and nylon 6/11.

The thermoplastic elastomer is preferably a thermoplastic elastomer selected from the group consisting of olefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers and polyurethane-based thermoplastic elastomers. As the olefin-based thermoplastic elastomer, it is typical to use a polyolefin such as polypropylene or polyethylene for the hard segment and an elastomer such as ethylene / propylene / diene terpolymer for the soft segment. It may be partially crosslinked when blending the polyolefin and the elastomer, or may be simply blended. Examples of the thermoplastic polyester elastomer include those using a hard segment such as polybutylene terephthalate having a high melting point and a high crystalline aromatic polyester resin and a soft segment such as polytetramethylene ether glycol or an aliphatic polyester. As the polyamide-based thermoplastic elastomer, a block copolymer having nylon such as nylon 6 or nylon 12 as a hard segment and a polyester or a polyol as a soft segment is typical. Further, the thermoplastic polyurethane elastomer includes, for example, a polymer chain composed of diisocyanate and a short-chain glycol as a hard segment, a polymer chain composed of diisocyanate and a polyol as a soft segment, and a caprolactone type, an adipic acid type, an ether type and the like can be mentioned.

In the roller of the present invention, if the adhesion between the bearing sleeve sliding part layer made of polyacetal resin and the outer peripheral part layer made of thermoplastic resin or thermoplastic elastomer is not sufficient, an adhesive layer is provided. preferable.
The resin constituting the adhesive layer is not limited, but it is preferable to use an unsaturated carboxylic acid-modified polyolefin resin or an unsaturated epoxy-modified polyolefin resin. Examples of the unsaturated carboxylic acid used for modification include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid and isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, nadic acid (endocis-bicyclo [2 1.2.1] Hept-5-ene-2,3-dicarboxylic acid), unsaturated dicarboxylic acids such as methyl nadic acid, tetrahydrophthalic acid and methyl hexahydrophthalic acid, or derivatives thereof such as anhydrides and esters. Specifically, maleic anhydride, itaconic anhydride, citraconic anhydride, allyl succinic anhydride, glutaconic anhydride, nadic acid anhydride, tetrahydrophthalic acid anhydride, methyl tetrahydrophthalic anhydride, monomethyl maleate, maleic acid. Examples include dimethyl acid and glycidyl maleate. Among these, anhydrides are preferable, and maleic anhydride and nadic acid anhydride are particularly preferable. As the unsaturated epoxy monomer, glycidyl acrylate, glycidyl methacrylate, itaconic acid mono- and diglycidyl esters, butenetricarboxylic acid mono-, di- and triglycidyl esters, nadic acid or methyl nadic acid and citraconic acid mono- and di- Examples thereof include glycidyl ester, glycidyl ester of p-styrenecarboxylic acid, and 3,4-epoxy-1-butene. Of these, glycidyl methacrylate is preferred.

The polyolefin used as the base resin for the modified polyolefin resin includes polypropylene resin, polyethylene resin, poly-4-methyl-1-pentene resin, and ethylene / α mainly containing ethylene such as ethylene / propylene copolymer. Examples thereof include an olefin copolymer, a copolymer of propylene containing propylene as a main component such as a propylene / ethylene copolymer, and an α-olefin other than propylene, and the like.

The graft modification is carried out by a conventional method using a radical initiator, and a grafted monomer having 0.1 to 10% by weight of a grafting monomer per modified polyolefin resin is preferably used.

A polyurethane resin can also be used as the adhesive layer. Examples of the polyurethane resin include a prepolymer type, a polyisocyanate type and an isocyanate modified polymer type.

The roller of the present invention can be manufactured by a known general molding method such as, but not limited to, a two-color extrusion molding method and a two-color injection molding method, or by applying them. However, the two-color extrusion method is preferable.

In the case of the two-color extrusion molding method, three extruders having an adhesive layer and two extruders having no adhesive layer are used to form a polyacetal resin and an adhesive layer, which will be described later, in a common die on a common die. A resin such as an acid-modified polyolefin resin and a thermoplastic resin or a thermoplastic elastomer constituting the outer peripheral layer are fed to extrude a rod-shaped article having a two-layer or three-layer structure. The outer shape of the rod-shaped object may be any shape, and the cross-section may be polygonal or elliptical, but among them, a round bar is preferable. Further, the rod-shaped material also includes one having a hollow or profile extrusion shape. This rod-shaped material may be used as it is, or the core portion or hollow portion made of polyacetal resin may be cut to form the bearing sleeve sliding portion. The cutting according to the length of the roller can be performed before or after the cutting of the core portion or the hollow portion.

When the inner diameter dimension accuracy of the bearing sliding layer is not so high, the polyacetal resin is used as an inner layer (bearing sliding) by using an injection molding die having a cylindrical core (slide core) by a two-color injection molding method. Part), a thermoplastic resin or a thermoplastic elastomer may be injection-molded to form an outer layer (outer peripheral part) to directly produce the roll of the present invention. Also in this case, the inner diameter portion of the bearing sliding portion can be cut. If necessary, an unsaturated carboxylic acid-modified polyolefin resin, an unsaturated epoxy-modified polyolefin resin or a polyurethane resin forming the adhesive layer may be used as an intermediate layer and injection molded on the way.

In either case of the extrusion molding method or the injection molding method, the shape of the boundary between the sliding portion layer and the outer peripheral layer or the outer periphery of the outer peripheral layer is not limited to the cylindrical shape. The adhesive layer may be injected as an intermediate layer during the two-color injection molding, or the adhesive layer may be applied or sprayed on the outer surface of the core after the injection of the core. Alternatively, the core portion and the outer peripheral portion may be separately molded, an adhesive layer may be applied or sprayed on the outer surface of the core portion, and then the two may be fitted together to manufacture the roller of the present invention.

[0021]

EXAMPLE A roller having an adhesive layer provided by the present invention is shown in FIG. In the figure, 1 is a bearing tube, 2 is a bearing tube sliding portion layer, 3 is an adhesive layer, 4 is an outer peripheral layer, and 5 is a sliding portion. 2 to 5, among the rollers of the present invention, one having a structure in which the bearing cylinder sliding portion is supported by a beam (FIG. 2), and improving the adhesiveness at the boundary between the sliding portion layer and the outer peripheral layer. 3A and 3B show an uneven shape for the purpose (FIGS. 3 and 4), and a groove (FIG. 5) is provided on the outermost surface of the outermost layer in order to enhance the carrying property of the object to be carried.

[0022]

EFFECTS OF THE INVENTION According to the roller of the present invention, the bearing cylinder sliding portion layer is made of polyacetal resin and has excellent slidability with respect to the shaft, and also has excellent abrasion resistance to an object to be conveyed such as paper. It has excellent transport performance and roller scratch resistance, and since it does not have a vulcanization step, it can simplify the manufacturing process, thus reducing the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a roller provided by the present invention.

[Figure 2]

FIG. 5 is a perspective view showing another example of the roller provided in the present invention.

[Explanation of symbols]

 A roller 1 bearing tube 2 bearing tube sliding part layer 3 adhesive layer 4 outer peripheral layer 5 sliding part

Claims (4)

[Claims] 1. A cylindrical laminated structure characterized in that a bearing cylinder sliding part layer in contact with a shaft is made of a polyacetal resin, and an outer peripheral part layer of the sliding part layer is made of a thermoplastic resin or a thermoplastic elastomer. Roller with structure. 2. The thermoplastic elastomer is a thermoplastic elastomer selected from the group consisting of olefin-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyamide-based thermoplastic elastomer and polyurethane-based thermoplastic elastomer. Roller described. 3. An unsaturated carboxylic acid-modified polyolefin resin layer, an unsaturated epoxy-modified polyolefin resin layer or a polyurethane resin layer is provided as an adhesive layer between the sliding portion layer and the outer peripheral portion layer. Roller described. 4. A bearing cylinder made of a polyacetal resin, the core of which is made of polyacetal resin, and the outer peripheral layer of which is extruded from a thermoplastic resin or thermoplastic elastomer. The method for producing a roller having a tubular laminated structure according to claim 1, wherein a sliding layer is formed.