JP2007015832A - Paper feeding roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding roller capable of improving close adhesion property between a surface layer and an inner layer when using silicone rubber causing no faulty image in the surface layer. <P>SOLUTION: This paper feeding roller 10 is composed of the inner layer 12 formed by soft polyurethane foam body in an outer peripheral part of a core member 11 and the surface layer 14 formed by a silicone rubber molded part bonded on an outer peripheral part of the inner layer 12 through an adhesive layer 13 of liquid silicone. It is preferable to use such silicone that has compatibility with the silicone constituting the silicone rubber molded part as the silicone constituting the liquid silicone. Preferably, viscosity of the liquid silicone is 50 to 60Pa s (25°C). It is preferable that a filling layer for preventing the inner layer 12 from being soaked by the liquid silicone is provided on a surface of the inner layer 12 formed of the soft polyurethane foam body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a paper feed roller and a paper discharge roller provided in an image forming apparatus that prints an image or a character on a recording paper using the principle of electrophotography, such as a copying machine (copy machine), a printer, a facsimile machine, and the like. The present invention relates to a paper feed roller (retard roller).

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a printer, and a facsimile, the surface of a photosensitive member (image carrier) is charged to a constant potential by corona discharge with a charging device and then recorded on the surface. An electrostatic latent image is formed by irradiating a pattern corresponding to an image or character with a laser oscillator. The obtained electrostatic latent image is developed and visualized by toner (developer) supplied from a developing roller of the developing device. Then, the toner image is transferred and fixed onto the recording paper supplied from the paper supply roller. Subsequently, the recording paper is discharged by a paper discharge roller.

As such a paper feed roller such as a paper feed roller and a paper discharge roller, a liquid film is formed by supplying a liquid rubber material such as liquid silicone rubber to the outer peripheral surface of a cylindrical molded product made of, for example, a synthetic resin foam. A molded product formed and dried and cured is known (for example, see Patent Document 1). Also known is a core material having a required length, a roller base material made of resin foam provided on the outer periphery thereof, and an EPDM rubber covering the outer peripheral surface of the roller base material (for example, , See Patent Document 2). In this case, the roller base material and the EPDM rubber are bonded by a moisture-curable one-component adhesive such as an epoxy resin or a urethane resin, or a hot melt adhesive.
Japanese Examined Patent Publication No. 6-7949 (first and second pages) JP 2005-82376 A (pages 2 and 4)

  However, in the conventional cylindrical molded product (roller) described in Patent Document 1, the free oil contained in the liquid rubber material adheres to the recording paper when the paper is fed, and an image is formed at the portion where the recording paper contacts the roller. There is a problem that a problem occurs such that the color of the color is changed (discolored). Further, in the paper feed roller described in Patent Document 2, a plasticizer or oil is often blended with the EPDM rubber on the surface. In this case, the plasticizer or oil bleeds on the surface and adheres to the recording paper. There has been a problem that a problem such as failure to feed paper properly occurs.

  Therefore, it is conceivable to use a silicone rubber that does not cause the above disadvantages as a material for forming the surface layer of the paper feed roller. In this case, since the silicone rubber is a material with poor adhesion, There is a problem that the adhesion between the silicone rubber and the polyurethane foam of the inner layer is insufficient.

  The present invention has been made paying attention to such problems of the prior art, and the object of the present invention is to use the surface layer and the inner layer when silicone rubber that does not cause image defects is used for the surface layer. It is to provide a paper feed roller that can improve the adhesiveness between the two.

  In order to achieve the above object, the paper feed roller of the invention according to claim 1 is provided with an inner layer made of a soft polyurethane foam on the outer peripheral portion of the core material, and liquid silicone as an adhesive on the outer peripheral portion of the inner layer. Thus, a surface layer made of a silicone rubber molded product is adhered and configured.

  According to a second aspect of the present invention, in the paper feeding roller of the first aspect, the silicone constituting the liquid silicone and the silicone constituting the silicone rubber molded product are compatible. It is what.

A paper feed roller according to a third aspect of the present invention is characterized in that the viscosity of the liquid silicone according to the first or second aspect is 50 to 60 Pa · s (25 ° C.). .
According to a fourth aspect of the present invention, there is provided the paper feed roller according to any one of the first to third aspects, wherein the surface of the inner layer made of the soft polyurethane foam is prevented from penetrating into the inner layer of the liquid silicone. For this purpose, a sealing layer is provided.

According to the present invention, the following effects can be exhibited.
In the paper feed roller according to the first aspect of the invention, since the surface layer is composed of a silicone rubber molded product, the plasticizer and oil are substantially not contained, and image defects and paper feed caused by them are not included. Can solve the problem. Further, the silicone rubber molded product is bonded to the outer peripheral portion of the inner layer made of polyurethane foam with liquid silicone as an adhesive. This liquid silicone has a good affinity for silicone rubber, and can improve the adhesion between the silicone rubber molded product of the surface layer and the soft polyurethane foam of the inner layer.

  In the paper feed roller according to the second aspect of the present invention, the silicone constituting the liquid silicone and the silicone constituting the silicone rubber molded product are compatible with each other. In addition, the adhesion between the silicone rubber molded product and the flexible polyurethane foam can be further improved.

  In the paper feed roller of the invention according to claim 3, the viscosity of the liquid silicone has a high viscosity of 50 to 60 Pa · s (25 ° C.). Accordingly, the penetration of the liquid silicone into the inner layer made of the flexible polyurethane foam can be suppressed, and in addition to the effect of the invention according to claim 1 or 2, the silicone rubber molded article and the flexible polyurethane foam are not affected. Adhesion can be further improved.

  In the paper feed roller according to the fourth aspect of the present invention, the sealing layer is provided on the surface of the inner layer made of the soft polyurethane foam, so that the penetration of the liquid silicone into the inner layer can be suppressed. For this reason, in addition to the effect of the invention according to any one of claims 1 to 3, the adhesion between the silicone rubber molded product and the flexible polyurethane foam can be further enhanced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in the cross-sectional view of FIG. 1, the paper feed roller 10 is provided with an inner layer 12 made of a soft polyurethane foam on the outer periphery of a synthetic resin core material 11, and an adhesive layer 13 made of liquid silicone on the outer periphery. A surface layer 14 made of a silicone rubber molded product is provided. The core material 11 is made of a synthetic resin (engineering plastic) having good mechanical strength. Examples of such a synthetic resin include polyacetal resin (POM), polyamide resin, and polyester resin.

  The soft polyurethane foam forming the inner layer 12 is a polyurethane foam having an open-cell structure and having flexibility and resilience. By using such flexible soft polyurethane as the inner layer 12 of the paper feed roller 10, a sufficient nip width can be obtained during paper feed. Such a flexible polyurethane foam is obtained by reacting, foaming and curing a raw material of a polyurethane foam containing polyols, polyisocyanates, a catalyst and a foaming agent.

  As the polyols, polyether polyols or polyester polyols are used. However, polyether polyols have better reactivity with polyisocyanates than polyester polyols, and the resulting polyurethane foam is less distorted and hardly hydrolyzed. Therefore, it is preferable to use a polyether polyol. As the polyether polyol, a polymer obtained by addition polymerization of propylene oxide to a polyhydric alcohol, a polymer obtained by addition polymerization of ethylene oxide, a polymer obtained by addition polymerization of propylene oxide and ethylene oxide, or a modified product thereof is used. It is done. The polyhydric alcohol is a compound having a plurality of hydroxyl groups in one molecule, and examples thereof include glycerin and dipropylene glycol.

  The average molecular weight of the polyether polyol is preferably 2000 to 6000. When the average molecular weight is less than 2000, the stability of the resulting polyurethane foam during molding is lowered, and when it exceeds 6000, the resilience performance of the polyurethane foam is remarkably increased and the cushioning property tends to be lowered. Show. This polyether polyol can change the number of functional groups and the hydroxyl group value of the hydroxyl group by adjusting the kind of raw material component, the molecular weight, the degree of condensation, and the like.

  The polyisocyanates to be reacted with the above polyols are compounds having a plurality of isocyanate groups, specifically, tolylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI). ), Aromatic polyisocyanates such as triphenylmethane triisocyanate and xylylene diisocyanate (XDI), alicyclic polyisocyanates such as isophorone diisocyanate (IPDI) and dicyclohexylmethane diisocyanate, and aliphatics such as hexamethylene diisocyanate (HDI) Polyisocyanates, or modified isocyanates such as free isocyanate prepolymers and carbodiimide-modified polyisocyanates by reaction of these with polyols, These mixtures polyisocyanate is used for. Of these, tolylene diisocyanate and derivatives thereof, 4,4-diphenylmethane diisocyanate and derivatives thereof are preferable, and these can also be used as a mixture.

  The isocyanate index of the polyisocyanates may be 100 or less or more than 100, but is preferably in the range of 100 to 110 in order to make the polyurethane foam suitable for the paper feed roller 10. When the isocyanate index is less than 100, the polyurethane foam becomes soft and the paper feed function of the paper feed roller 10 is lowered. On the other hand, when the isocyanate index exceeds 110, the polyurethane foam tends to be hard, and the elasticity as the paper feed roller 10 is lowered. Here, the isocyanate index represents the equivalent ratio of isocyanate groups of polyisocyanates to active hydrogen groups such as polyols and foaming agents in percentage.

  Catalysts include urethanization reaction (resinification reaction) between polyols and polyisocyanates, foaming reaction between polyisocyanates and water, and curing reaction (crosslinking reaction) between these reaction products and polyisocyanates. This is to promote the reaction. Specific examples of such catalysts include tertiary amines such as triethylenediamine (TEDA), dimethylethanolamine, N, N ′, N′-trimethylaminoethylpiperazine, organometallic compounds such as tin octylate (tin octoate), and acetic acid. Salts, alkali metal alcoholates and the like are used. As other catalysts, morpholine catalysts such as N-methylmorpholine and N-ethylmorpholine can also be used in order to improve the curability on the foam surface. The compounding amount of the catalyst is about 0.05 to 0.5 parts by mass per 100 parts by mass of polyols.

  The foaming agent is for obtaining a polyurethane foam by foaming polyurethane, and typically includes water as a chemical foaming agent. Water mainly reacts with polyisocyanates (foaming reaction) to generate carbon dioxide gas. As the foaming agent, other chemical foaming agents or physical (mechanical) foaming agents can be used in addition to water. Examples of the chemical foaming agent include organic acids, inorganic acids, alkali metal carbonates and the like. These chemical foaming agents generate gas by reaction with raw material components of the flexible polyurethane foam or decomposition by heating. On the other hand, examples of the physical blowing agent include gases such as pentane and methylene chloride. The blending amount of water as a blowing agent is preferably about 1 to 7 parts by mass per 100 parts by mass of polyols. When the amount of water is less than 1 part by mass, the foaming reaction is insufficient and the cushioning property of the foam tends to be impaired. When the amount exceeds 7 parts by mass, the foaming reaction becomes excessive and foaming occurs. Your body may become too soft.

  As the foam stabilizer, any of those usually blended in the raw material of polyurethane foam can be used. For example, nonionic surfactant such as organosiloxane-polyoxyalkylene copolymer, sodium dodecylbenzenesulfonate, lauryl Examples thereof include anionic surfactants such as sodium sulfate, and phenolic compounds. The blending amount of the foam stabilizer is preferably about 0.1 to 2.0 parts by mass per 100 parts by mass of polyols. In addition, as a raw material for the flexible polyurethane foam, a cell opener such as a polyalkylene oxide polyol, a flame retardant such as a condensed phosphate ester, an antioxidant, a plasticizer, an ultraviolet absorber, a colorant, and the like can be used.

  A flexible polyurethane foam obtained from such a raw material has a three-dimensional communication structure in which a skeleton extends in a three-dimensional network, a number of cells are formed therebetween, and the cells extend three-dimensionally continuously. is doing. In addition, the flexible polyurethane foam has a certain strength and required elasticity based on the properties of the polyurethane composed of the hard segment and the soft segment, and can exhibit good distortion (restorability). . The average cell diameter based on JIS K6400 of the flexible polyurethane foam is preferably 100 to 700 μm. When the average cell diameter is less than 10 μm, the skeleton portion increases and the surface tends to be hard, and when it exceeds 700 μm, the cell becomes large and the space portion increases, the strength decreases, and the durability is insufficient.

Moreover, it is preferable that the density (apparent density) based on JISK7222: 1999 of a flexible polyurethane foam is 20-300 kg / m < ³ >. When the density is less than 20 kg / m ^3, the number of skeleton parts forming the cell is reduced, and the cell is enlarged and the strength is lowered. On the other hand, when the density exceeds 300 kg / m ³ , the skeleton portions forming the cells may increase and become too hard. Furthermore, the average number of cells based on JIS K6400-1: 2004 of the flexible polyurethane foam is preferably 20 to 250 cells / 25 mm. When the average number of cells is less than 20/25 mm, the number of skeleton portions forming the cells decreases, and the cells become larger and the strength decreases. On the other hand, when it exceeds 250 pieces / 25 mm, there is a possibility that the skeleton portions forming the cells increase and become too hard.

  The silicone rubber molded article forming the surface layer 14 is a silicone rubber molded article which does not substantially contain a plasticizer or an oil component and does not cause a bleeding problem due to those components. In addition, the silicone rubber molded product has a large surface friction coefficient and a smooth surface, so that the paper feeding function as the paper feeding roller 10 can be satisfactorily exhibited. Examples of such silicone rubber include millable silicone rubber and room temperature curable silicone rubber. The millable silicone rubber is obtained by using a linear polyorganosiloxane having a high degree of polymerization as a main raw material, blending a kneading agent, a dispersing agent, a vulcanizing agent, and the like, kneading the mixture, and heat curing. As the polyorganosiloxane, methyl vinyl silicone or the like is used. On the other hand, room temperature curable silicone rubber is composed of terminally reactive diorganopolysiloxane as a main component, blended with a crosslinking agent, a catalyst, a reinforcing agent, etc., and cured at room temperature with one liquid or two liquids separately from the curing agent. It is obtained. The thickness of the surface layer 14 is normally set to 0.7 to 2 mm in order to properly exhibit the paper feeding function of the paper feeding roller 10.

  The liquid silicone forming the adhesive layer 13 is a compound for adhesively bonding between a silicone rubber molded product and a flexible polyurethane foam. There are 1 liquid type and 2 liquid type in the liquid silicone. The 1 liquid type includes dealcohol type, deoxime type, deacetic acid type, etc. The 2 liquid type includes condensation type and addition type. It is done. Of these, a one-component type that has excellent adhesion to both the silicone rubber molded product that forms the surface layer 14 and the soft polyurethane foam that forms the inner layer 12, and a deoxime-type liquid silicone that is easy to handle. preferable. Moreover, what has compatibility with the silicone which comprises liquid silicone, and the silicone which comprises the said silicone rubber molded product is preferable in order to improve the adhesiveness of the contact bonding layer 13 with respect to a silicone rubber molded product.

  Furthermore, the viscosity of the liquid silicone is preferably 50 to 60 Pa · s (25 ° C.). When this viscosity is less than 50 Pa · s, the viscosity of the liquid silicone becomes low and the liquid polyurethane foam easily penetrates, and the adhesiveness to the soft polyurethane foam decreases. On the other hand, when the viscosity exceeds 60 Pa · s, the viscosity increases, the applicability to the surface of the soft polyurethane foam deteriorates, the adhesiveness to the soft polyurethane foam decreases, and the handleability also deteriorates.

  The thickness of the adhesive layer 13 made of liquid silicone is preferably about 0.5 to 2 mm. When this thickness is less than 0.5 mm, the liquid silicone soaks into the soft polyurethane foam and tends to be insufficient for the liquid silicone that can contribute to adhesion. On the other hand, when the thickness exceeds 2 mm, the amount of liquid silicone present between the inner layer 12 and the surface layer 14 becomes too large, and this tends to slow the curing, which is not preferable.

  It is preferable to provide a sealing layer for suppressing penetration of the liquid silicone into the inner layer 12 on the surface of the inner layer 12 made of the flexible polyurethane foam. By this sealing layer, liquid silicone can be present between the silicone rubber molded article and the flexible polyurethane foam to sufficiently exhibit the adhesive function. As a material for forming the sealing layer, polyurethane or the like is used.

Next, a method for manufacturing the paper feed roller 10 will be described.
As shown in FIG. 2 (a), the inner layer 12 made of a cylindrical soft polyurethane foam is supported by a support tool (not shown) and rotated at a constant speed. In this state, the outer layer of the inner layer 12 The liquid silicone 16 is sprayed from the coating nozzle 15 that moves at a constant speed along the axial direction. By this operation, the adhesive layer 13 of the liquid silicone 16 having a certain thickness is formed on the outer peripheral portion of the inner layer 12. Next, the surface layer 14 made of a cylindrical silicone rubber molded product is fitted into the outer peripheral portion of the inner layer 12 to obtain the state shown in FIG. By leaving in this state for a predetermined time, the surface layer 14 is bonded and integrated with the outer peripheral portion of the inner layer 12. Thereafter, as shown by a two-dot chain line in FIG. 2B, the paper feed roller 10 is cut into a constant width necessary.

  In another manufacturing method, as shown in FIG. 3, an inner layer 12 made of a cylindrical soft polyurethane foam and a surface layer 14 made of a silicone rubber molded product are cut in advance to the width of the paper feed roller 10. deep. Next, liquid silicone 16 is applied to the inner peripheral surface of the surface layer 14, and then the inner layer 12 is fitted into the inner peripheral portion of the surface layer 14. By leaving in this state for a predetermined time, the surface layer 14 is bonded and integrated with the outer peripheral portion of the inner layer 12. Thereafter, as shown in FIG. 4, the paper feed roller 10 is manufactured by inserting the core material 11 through the insertion hole 17 of the inner layer 12.

  Since the above paper feed roller 10 is mainly used in an image forming apparatus, the image forming apparatus will be briefly described. A charging roller rotates above the photoconductor while being pressed against the photoconductor at a constant pressure, and charges the surface of the photoconductor to a constant potential by corona discharge. In the rotation direction of the photoreceptor, an exposure unit is provided at a position adjacent to the charging roller, and a pattern corresponding to an image or character to be recorded in the exposure unit is irradiated with a laser oscillator to form an electrostatic latent image. Is done. A developing unit is provided at a position adjacent to the exposure unit, and toner is supplied onto the photoconductor, and the electrostatic latent image on the photoconductor is developed with the toner and visualized with the toner image. A transfer roller is provided below the photoconductor, and the recording paper is fed from the paper feed roller between the photoconductor and the transfer roller.

  That is, as shown in FIG. 5, the pair of upper and lower paper feed rollers 10 are arranged so as to contact each other and are configured to rotate in opposite directions. When the leading edge of the recording paper 18 reaches between both paper feed rollers 10, the recording paper 18 is fed forward at a speed corresponding to the rotational speed of the both paper feed rollers 10. Then, the toner image on the photosensitive member is transferred to the recording paper 18. A fixing unit is provided in the traveling direction of the recording paper 18 from the transfer roller, and a heat roller and a pressure roller constituting the fixing unit are arranged at the upper and lower positions with the recording paper 18 interposed therebetween and transferred to the recording paper 18. The toner image is fixed. Thereafter, the recording paper 18 is discharged by a paper discharge roller to complete printing.

  Now, the operation of the present embodiment will be described. The inner layer 12 made of a cylindrical soft polyurethane foam is formed by injecting and reacting the raw material of the soft polyurethane foam into the mold, and foaming and curing. . On the other hand, silicone rubber is poured into a mold and cured by heating to form a surface layer 14 made of a cylindrical silicone rubber molded product. And after apply | coating the liquid silicone 16 to the outer peripheral surface of the inner layer 12, and forming the contact bonding layer 13, the paper feed roller 10 is obtained by making the surface layer 14 fit.

  In this case, the liquid silicone 16 used as an adhesive is the same kind of silicone rubber as the silicone rubber forming the surface layer 14, and both can exhibit compatibility, and the chemical bondability is enhanced. At the same time, the liquid silicone 16 exhibits a certain viscosity, so that the penetration of the inner layer 12 into the soft polyurethane foam is suppressed, and exists between the inner layer 12 and the surface layer 14, thereby exhibiting sufficient adhesiveness between the two. . Therefore, by using the liquid silicone 16 as an adhesive, the silicone rubber molded product of the surface layer 14 and the soft polyurethane foam of the inner layer 12 are favorably bonded.

The effects exhibited by the above embodiment will be described collectively below.
In the paper feed roller 10 in the present embodiment, since the surface layer 14 is formed of a silicone rubber molded product, the plasticizer and oil are substantially not included, and image defects and paper feed caused by them are not included. Trouble can be solved. Further, the silicone rubber molded product is bonded to the outer peripheral portion of the inner layer 12 made of a soft polyurethane foam with a liquid silicone 16 as an adhesive. The liquid silicone 16 has a good affinity with silicone rubber, and can improve the adhesion between the silicone rubber molded product of the surface layer 14 and the soft polyurethane foam of the inner layer 12.

  The silicone constituting the liquid silicone 16 and the silicone constituting the silicone rubber molded product are compatible, so that the silicone rubber molded product of the surface layer 14 and the soft polyurethane foam of the inner layer 12 The adhesion can be further improved.

  Moreover, since the viscosity of the liquid silicone 16 is 50 to 60 Pa · s (25 ° C.), the penetration of the liquid silicone 16 into the soft polyurethane foam can be suppressed, and the silicone rubber molded product and the soft polyurethane foam Can be further improved.

  -By providing a sealing layer on the surface of the inner layer 12 made of a soft polyurethane foam, the penetration of the liquid silicone 16 into the soft polyurethane foam can be further suppressed, and a silicone rubber molded product, a soft polyurethane foam, Can be further improved.

Hereinafter, the embodiment will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.
Example 1
The paper feed roller 10 shown in FIG. 4 was manufactured by the method shown in FIGS. 2 (a) and 2 (b). That is, the liquid silicone 16 as an adhesive is sprayed on the outer peripheral portion of the inner layer 12 made of a cylindrical soft polyurethane foam to form the adhesive layer 13, and the surface layer 14 made of a silicone rubber molded product is fitted and adhered thereto. . Then, it cut | disconnected to the fixed width | variety and the core material 11 was penetrated to the penetration hole 17, and the paper feed roller 10 was obtained. As the core material 11, polyacetal resin (POM) was used. The inner layer 12 was manufactured by supplying a raw material of a flexible polyurethane foam into a mold, causing it to react, foaming and curing. This flexible polyurethane foam was obtained by preparing a polyether polyol as a polyol, tolylene diisocyanate as a polyisocyanate, water as a foaming agent, and other raw materials according to conventional methods, reacting, foaming and curing. Its apparent density was 55 kg / m ³ .

As the liquid silicone 16, one-pack type deoxime-type silicone [GESE Toshiba Silicone Co., Ltd., TSE387] was used. The viscosity of the liquid silicone 16 was 60 Pa · s (25 ° C.). And 30g was apply | coated to the outer peripheral surface of the inner layer 12 (the inner layer 12 is 31.5 mm in diameter, 310 mm in length). On the other hand, as the silicone rubber molded product forming the surface layer 14, millable silicone rubber was used. The raw material was subjected to primary vulcanization by press molding at 170 ° C. for 10 minutes. Subsequently, secondary vulcanization was performed at 200 ° C. for 4 hours. The obtained silicone rubber molded product has a specific gravity of 1.07 (25 ° C.), a JIS A hardness of 31 degrees, a tensile strength of 3.2 MPa (32 kgf / cm ² ), an elongation of 240%, and a tear strength of 80 N / cm (8 kgf). / Cm). The thickness of the surface layer 14 by the silicone rubber molded product was about 1.5 mm.

Then, the surface layer 14 was fitted to the inner layer 12 coated with the liquid silicone 16 and cured at room temperature to obtain a paper feed roller 10. The thickness of the adhesive layer 13 made of the liquid silicone 16 was about 1 mm. With respect to the paper feed roller 10, the adhesion between the surface layer 14 and the inner layer 12 was measured by the following method. The results are shown in Table 1.
(Measurement method of adhesion)
The surface layer 14 of the paper feed roller 10 was pinched by hand and pulled in a direction (radial direction) perpendicular to the tangential direction on the outer peripheral surface of the surface layer 14, and the adhesion was evaluated according to the following criteria.

(Circle): The soft polyurethane foam of the inner layer 12 destroyed.
X: Interfacial breakage occurred between the surface layer 14 and the adhesive layer 13 or between the adhesive layer 13 and the inner layer 12.
(Example 2)
In Example 1, it carried out like Example 1 except having used 1 part type deoxime type silicone [GEE (GE) Toshiba Silicone Co., Ltd. make, TSE382] as liquid silicone 16 of adhesives. . The obtained paper feed roller 10 was measured for the adhesion between the surface layer 14 and the inner layer 12 in the same manner as in Example 1, and the results are shown in Table 1.
(Comparative Example 1)
In Example 1, it implemented like Example 1 except having used the hot-melt-adhesive which consists of ethylene-vinyl acetate copolymer (EVA) as an adhesive agent. For the obtained paper feed roller, the adhesion between the surface layer and the inner layer was measured in the same manner as in Example 1, and the results are shown in Table 1.
(Comparative Example 2)
In Example 1, it carried out like Example 1 except having used the alpha cyanoacrylate adhesive (instant adhesive) as an adhesive agent. For the obtained paper feed roller, the adhesion between the surface layer and the inner layer was measured in the same manner as in Example 1, and the results are shown in Table 1.
(Example 3)
In Example 1, the sealing agent shown below was applied to the surface of the soft polyurethane foam constituting the inner layer 12, and the sealing layer was formed by volatilizing the organic solvent. Others were carried out in the same manner as in Example 1. The obtained paper feed roller 10 was measured for the adhesion between the surface layer 14 and the inner layer 12 in the same manner as in Example 1, and the results are shown in Table 1.

  Sealing agent: One-pack type polyurethane for coating (MDI), methyl ethyl ketone (MEK) as an organic solvent, adjusted to a solid content of 35% by mass, and its viscosity was 400 P (25 ° C.).

表１に示したように、実施例１〜３では内層１２の軟質ポリウレタン発泡体が破壊し、表面層１４と内層１２との間に十分な接着力が得られた。これは、液状シリコーン１６を構成するシリコーンとシリコーンゴム成形品を形成するシリコーンとが相溶性を有するとともに、液状シリコーン１６の粘性が高く、軟質ポリウレタン発泡体への染み込みが抑えられた結果であると推測される。さらに、実施例３では内層１２表面に目止め層を設けたことから、軟質ポリウレタン発泡体中への液状シリコーン１６の染み込み（浸透）が抑制され、実施例１及び２に比べて一層高い接着力が得られた。一方、比較例１ではホットメルト接着剤を用いたことから、接着性の低いシリコーンゴム成形品に接着せず、界面破壊をした。比較例２ではα−シアノアクリレート系接着剤を使用したが、その粘度が低いため軟質ポリウレタン発泡体中に染み込んで、その軟質ポリウレタン発泡体に対して接着しない結果となった。

As shown in Table 1, in Examples 1 to 3, the flexible polyurethane foam of the inner layer 12 was broken, and sufficient adhesive force was obtained between the surface layer 14 and the inner layer 12. This is because the silicone constituting the liquid silicone 16 and the silicone forming the silicone rubber molded product are compatible with each other, and the viscosity of the liquid silicone 16 is high, so that the penetration into the flexible polyurethane foam is suppressed. Guessed. Further, in Example 3, the sealing layer was provided on the surface of the inner layer 12, so that the penetration (penetration) of the liquid silicone 16 into the flexible polyurethane foam was suppressed, and higher adhesive strength than in Examples 1 and 2. was gotten. On the other hand, in Comparative Example 1, since a hot melt adhesive was used, it did not adhere to a silicone rubber molded product having low adhesiveness, and the interface was destroyed. In Comparative Example 2, an α-cyanoacrylate-based adhesive was used, but because of its low viscosity, it penetrated into the soft polyurethane foam and did not adhere to the soft polyurethane foam.

It should be noted that the present embodiment can be implemented with the following modifications.
-It is also possible to apply an adhesion promoter (primer) for enhancing the adhesion between the two on the outer peripheral surface of the inner layer 12 made of a soft polyurethane foam or the inner peripheral surface of the surface layer 14 made of a silicone rubber molded product. is there.

-As a soft polyurethane foam of the inner layer 12, the surface can have a skin layer whose density is higher than the inside, and it can also be comprised so that the penetration of liquid silicone may be suppressed.
-Polyester etc. can also be used as a material which forms the said sealing layer.

-It is also possible to comprise so that the surface of a soft polyurethane foam or a silicone rubber molded product may have a functional group such as a hydroxyl group for enhancing adhesiveness.
Further, the technical idea that can be grasped from the embodiment will be described below.

  The paper feed roller according to any one of claims 1 to 4, wherein the liquid silicone is a one-component type and a deoxime type. When comprised in this way, in addition to the effect of the invention which concerns on any one of Claims 1-4, the adhesiveness with respect to both a silicone rubber molded product and a flexible polyurethane foam can be improved.

  The paper feed roller according to any one of claims 1 to 4, wherein the paper feed roller is used as a paper feed roller or a paper discharge roller of the image forming apparatus. When configured in this manner, the effects of the invention according to any one of claims 1 to 4 can be satisfactorily exhibited with respect to the paper feed roller or paper discharge roller of the image forming apparatus.

FIG. 3 is an enlarged sectional view showing a paper feed roller in the embodiment. (A) is a disassembled perspective view which shows the member of the process of manufacturing a paper feed roller, (b) is a perspective view which shows the member of the post process of (a). The disassembled perspective view which shows the member of the manufacturing process different from FIG. The perspective view which shows a paper feed roller. The front view which shows the use condition of a paper feed roller.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Paper feed roller, 11 ... Core material, 12 ... Inner layer, 14 ... Surface layer.

Claims (4)

An inner layer made of a soft polyurethane foam is provided on the outer periphery of the core material, and a surface layer made of a silicone rubber molded product is adhered to the outer periphery of the inner layer with liquid silicone as an adhesive. roller. The paper feed roller according to claim 1, wherein the silicone constituting the liquid silicone and the silicone constituting the silicone rubber molded product have compatibility. The paper feed roller according to claim 1, wherein the liquid silicone has a viscosity of 50 to 60 Pa · s (25 ° C.). The paper according to any one of claims 1 to 3, wherein a sealing layer for suppressing penetration of liquid silicone into the inner layer is provided on a surface of the inner layer made of the flexible polyurethane foam. Feed roller.

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