JP3249850B2 - Rubber material for paper feed - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION The present invention is, (a) pre during the manufacturing process
The present invention relates to a paper feed rubber member made of a resin composition containing an oil- extended ethylene-propylene copolymer rubber to which extension oil is added and (ii) a specific organopolysiloxane.

[0002]

2. Description of the Related Art Heretofore, as a rubber composition for a roll member, a vulcanizable composition containing a polyurethane, a composition containing a polynorbornene-based polymer, and the like have been known. Roll members obtained from these compositions are useful, for example, as rubber rolls or pads for feeding or transporting as disclosed in JP-B-62-56061 and JP-A-60-170337. And are often used in OA equipment such as copiers and various financial terminals.

[0003] The rubber composition constituting these rubber members is characterized by the fact that paper sheets can be transported relatively accurately from the viewpoint of a paper feed roll.
It is a rubber composition most often used as a rubber roll for equipment. By the way, in recent years, there has been a remarkable demand for improvement in performance of OA equipment, and improvement in the transport speed of paper sheets is no exception. For example, there is a performance demand that the copying speed of a copying machine, a facsimile, and the like be remarkably improved, and the transport performance of paper sheets must be improved in accordance with the improvement of the performance of the equipment itself.

[0004] However, conventionally used,
Various urethane-based rubbers and polynorbornene-based rubbers have problems such as the effect of paper dust accompanying transport under various environments and the problem that the surface of the rubber itself gradually hardens. When transported, the coefficient of friction of the rubber itself decreases,
As a result, there is a problem that the transfer performance is remarkably reduced, and it cannot be said that the conventional equipment can sufficiently cope with the problem. Can not be said to be able to respond appropriately.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a paper feeding rubber member which can solve the above problems. Also,
With excellent paper feeding performance, the performance is not affected by changes in the environment, and excellent paper feeding performance over a long period of time, that is, a friction coefficient is maintained, a rubber member excellent in weather resistance,
Among them, an object of the present invention is to provide a rubber composition particularly useful for producing a rubber roll. It is still another object of the present invention to provide a paper feed rubber member having excellent paper feed performance and weather resistance obtained from the rubber composition.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems, and is directed to an oil-extended ethylene-propylene copolymer rubber or an organopolypropylene specific to ethylene-propylene copolymer rubber. Compound siloxane,
It is characterized in that it is used for a paper feeding rubber member or a pad member having excellent performance. That is, according to the present invention, a mixture 9 comprising the following components (A) and (B)
5 to 50% by weight and the following component (C) 5 to 50% by weight (where the total of (A), (B) and (C) is 100% by weight, (A) is at least 30% by weight, B) may be 0.) is provided. (A) 20 to 120 parts by weight of extender oil is added during the production process to 100 parts by weight of ethylene / propylene copolymer rubber.
Oil extended ethylene-propylene copolymer rubber; (B) the non-oil extended ethylene-propylene copolymer rubber; (C) the average compositional formula _{RnSiO (4-n) / 2} ( wherein, in R is a substituted or unsubstituted one Represents a monovalent hydrocarbon group, n is 1.98 to 2.05
Represents the number of A) an organopolysiloxane having at least two aliphatic unsaturated bonds and / or mercapto groups in one molecule;

[0007]

DETAILED DESCRIPTION OF THE INVENTION An important technical feature of the present invention is that a rubber member for feeding paper is provided from a rubber composition containing an oil-extended ethylene-propylene copolymer rubber and a specific organopolysiloxane as essential components. is there. Further, an important technical feature of the present invention is that the rubber composition has a hardness of
An object of the present invention is to provide a paper feed rubber member having a temperature of 60 ° (JIS A) or less.

[0008] The one oil-extended ethylene-propylene copolymer rubber is a component of the composition in the present invention, ethylene -
Extending oil during the process of producing propylene copolymer rubber
It is obtained by adding
"Esplen 606" used in the examples,
"Esprene 660F" is exemplified . Amount of extender oil added to 100 parts by weight of ethylene-propylene copolymer rubber
Is from 20 to 120 parts by weight . The ethylene / propylene copolymer rubber means a rubbery copolymer composed of an ethylene / propylene / diene terpolymer (EPDM). Examples of the diene in the EPDM include 5-methylene- Examples include 2-norbornene, 5-ethylidene-2-norbornene, dicyclopentadiene, cyclooctadiene, and 1,4-hexadiene. Preferred EPDM used in the present invention is
Propylene content of 10 to 70 mol%, iodine value of 3
To 25 are used.

The extender oil means a petroleum softener used in the production of oil-extended rubber, and specific examples thereof include paraffin oil and naphthene oil.

[0010]

The ethylene-propylene copolymer rubber as one component of the rubber composition in the present invention means a rubber prepared from ethylene and propylene which has been known before the present application.

In order for the rubber composition to be vulcanized, particularly co-vulcanized, to have a good paper feed performance at a hardness of 60 ° or less, at least 30% by weight of an oil-extended ethylene-propylene copolymer and a non-oil The sum of the extended ethylene-propylene copolymer rubber is 50 to 95% by weight, preferably 55 to 90% by weight in the rubber composition. If the ratio exceeds the above range, it becomes impossible to provide a rubber roll member having stable performance.

The organopolysiloxane, another essential component of the composition of the present invention, has an average compositional formula of RnS
iO _{(4-n) / 2} (wherein, R represents a substituted or unsubstituted monovalent hydrocarbon group, and n represents a number from 1.98 to 2.05), and is aliphatically unsaturated in one molecule. It means an organopolysiloxane having at least two bonds and / or mercapto groups. The organopolysiloxane may comprise the components (A), (B) and (C) described in the claims.
It is contained in an amount of 5 to 50% by weight in the total amount of the components.

In the above formula, a substituted or unsubstituted C
₁ to C ₈ hydrocarbon groups include, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,
Pentyl, 3,3,3-trifluoropropyl, γ-cyanoethyl and γ-cyanopropyl groups, C ₂ to C ₄ alkenyl groups (for example, vinyl, allyl and 2-butenyl groups), substituted or unsubstituted by halogen atoms. A substituted C ₆ -C ₈ mononuclear aryl group (eg, phenyl,
Chlorophenyl, tolyl, and tolylfluoromethylphenyl groups). It is preferred that at least 60%, especially 70%, of the number of groups represented by R are methyl groups.

In the above formula, examples of the aliphatic unsaturated bond include ethylene, propylene, butylene and the like.

The organopolysiloxane in the present invention is obtained by, for example, hydrolyzing dimethyldichlorosilane to obtain octamethylcyclotetrasiloxane, which is heated by using an acid or an alkali as a catalyst. Can be exemplified, but the compound is not limited to this compound, and naturally includes those obtained by other known methods. R ¹³ _-a (R ² O) _a SiO (R ¹ SiO) _b Si (OR ² ) _a R ¹³ _-a (wherein, R ¹ is substituted or unsubstituted by the same or different halogen atom or cyano group) C ₁ to C ₈
R ² is a hydrogen atom, C ₁ to C ₄
A represents 0 or 1, b represents a number having a value sufficient to give a viscosity of at least 1 million mPaS at 25 ° C., and at least 50% of the number of groups represented by the R ¹ group Is a methyl group, and 0.005 to 0.5 mol% of the unit constituting one component of the rubber component is represented by the formula (CH ₂ ＣC
H) (R ¹ ) SiO and (CH ₂ ＣＨCH) R ¹² _-a (R ²
O) _a Si _0.5 ).

A preferred method for producing a paper feed rubber member from the rubber composition of the present invention is a method of producing a paper feed rubber member by co-vulcanizing the rubber composition. It is also possible to manufacture the paper feed rubber member by employing a method other than the above. Co-vulcanization of the composition of the present invention is performed by first compounding and kneading compounding materials such as a vulcanizing agent, a vulcanizing aid, and a filler in a conventional manner with a rubber composition, and then using a known vulcanizing pot or the like. It can be vulcanized by a method. More specifically, a conventional compounding agent such as silica or carbon black is mixed with the polymer of the composition, and kneaded with a kneader or the like at 100 to 160 ° C. for 15 to 30 minutes. To this mixture, as a vulcanizing agent, dicumyl peroxide, 1,1-bis (tert-butylperoxy) -3,3,3
5-Trimethylcyclohexane or tertiary butyl cumyl peroxide is added to, for example,
Knead at 0-70 ° C for 8-15 minutes. Next, the kneaded material is set in a vulcanizing pot or poured into a mold, and then, for example, at 140 to 180 ° C. for 10 minutes.
By heating for 60 minutes
(JISA) The following co-vulcanized product can be obtained. A rubber roll member having a hardness exceeding 60 ° has a disadvantage that paper sheets cannot be accurately conveyed.

The rubber composition of the present invention may contain a filler, a softener, a reinforcing agent, and the like, which are generally recognized as rubber compounding agents in the art, within a range not to impair the object of the present invention. Examples of the filler include calcium carbonate and hard clay, examples of the softener include paraffin oil and a siloxane oligomer having a terminal OH group, and examples of the reinforcing agent include silica and carbon black. Further, in the rubber composition of the present invention,
An auxiliary agent such as a silane coupling agent may be blended.

The rubber member for paper feeding according to the present invention is characterized in that at least the surface of the rubber member for paper feeding which is in contact with paper is formed of a co-vulcanized product of a specific ethylene-propylene rubber and a specific organopolysiloxane. Can be ". To explain this in more detail, for example, when the rubber layer of the paper feed rubber member is a laminate, the rubber of the rubber layer that comes into contact with the uppermost paper is the specific ethylene-propylene rubber and the specific organopolypropylene. It means that it is a co-vulcanizate with siloxane, and it also includes that at least a part of the rubber layer on the surface of the paper feed rubber member that contacts the paper is the above-mentioned specific rubber co-vulcanizate. .

[0020]

The present invention will be described in more detail with reference to the following examples. Example 1 The mixture shown in Table 1 was heated at 120 ° C. using a kneader.
And knead for 20 minutes. This mixture is kneaded with an extruder, and the mixture is extruded from a die to obtain a tube. The extrusion temperature was kept at 80 ° C. Then, a vulcanized core was inserted into the obtained tube-shaped material, and pressed with a Lumirror film, and then pressed and heated at 150 ° C., 4 kgf / cm ² for 1.5 hours, and the vulcanized rubber layer was pressed. Was obtained. The hardness of this rubber member was 35 °. The paper feed performance and weather resistance of the obtained rubber member were measured. Table 2 shows the measurement results.
And graphs 2 and 3. It has been found that this rubber member has remarkably excellent weather resistance and retains excellent paper feeding ability for a long period of time.

Example 2 The mixture shown in Table 1 was heated at 120 ° C. using a kneader.
And knead for 20 minutes. The mixture was poured into a mold in which a cored bar was previously arranged, and heated at 170 ° C. for 10 minutes under a pressure to obtain a rubber member having a vulcanized rubber layer. The hardness of this rubber member was 45 °. The paper feed performance and weather resistance of the obtained rubber member were measured. The measurement results are shown in Table 2 and Graphs 2 and 3. This rubber member also had excellent sheet feeding ability and weather resistance, similarly to the rubber member obtained in Example 1.

[0022] * Sumitomo Chemical's Esplen 606 is 40 parts by weight of extender oil per 100 parts by weight of ethylene-propylene copolymer, and Sumitomo Chemical's Esplen 600F is 10 parts by weight of ethylene-propylene copolymer.
Contains 100 parts of extender oil per 0 parts by weight.

COMPARATIVE EXAMPLE 1 In Example 1, a polynorbornene-based rubber was used in place of the oil-extended ethylene-propylene copolymer rubber and the organopolysiloxane-based composition. A rubber member for paper feeding was obtained. The paper feed performance and weather resistance of the obtained rubber member were measured. The measurement results are shown in Table 2 and Graphs 2 and 3. This rubber member has no weather resistance,
Paper feeding capacity could not be maintained for a long time.

Comparative Example 2 In Example 1, a non-oil-extended ethylene-propylene copolymer rubber EP was used instead of the oil-extended ethylene-propylene copolymer rubber.
Using T-3045 (manufactured by Mitsui Petrochemical Co., Ltd.), and otherwise operating in the same manner as in Example 1, a paper feed rubber member was obtained. The paper feed performance and weather resistance of the obtained rubber member were measured. The measurement results are shown in Table 2 and Graphs 2 and 3. This rubber member could not exhibit sufficient paper feeding performance after long-term use.

[0025] Note that the paper feed performance in Table 2 was measured using the obtained rubber member.
This indicates the conveying force after the sheet has been fed. The conveying force is represented by (friction coefficient) × (load). The conveying force was such that a roll having a width of 25 mm was rotated on a paper surface under a load of 200 gf, and the force applied to the paper was measured by a load cell. The weather resistance was measured by measuring the conveying force after irradiating the obtained rubber member with ultraviolet light for 8 hours, and calculating the retention ratio with respect to the conveying force before irradiating ultraviolet light. The coefficient of friction of Example 1 and Comparative Example 2 was measured using a Haydon friction meter (200 gf load, manufactured by Shinto Kagaku), and was found to be 1.5 and 0.6, respectively.

[0026]

According to the present invention, a rubber composition having excellent weather resistance can be provided. Further, according to the present invention, compared with urethane-based or polynorbornene-based rubber, which is a material for a conventionally used paper feed rubber member, the weather resistance is remarkably improved, and over a long period, various types of rubber are used. Provided is a rubber member that retains excellent paper feeding performance when paper is fed, and this rubber member is, for example, a rubber roll that feeds office equipment such as a copier, a facsimile, and a financial terminal. It is also suitably used as a double feed prevention pad and a double feed prevention roll for paper feeding.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a rubber roll which is a preferred example of a rubber member for feeding paper according to the present invention.

FIG. 2 is a graph showing the paper feeding performance of a rubber member.

FIG. 3 is a graph showing the weather resistance of a rubber member.

[Explanation of symbols]

 1: Rubber roll 2: Core

Claims (2)

(57) [Claims] 1. A mixture comprising the following components (A) and (B): 95 to 50% by weight and the following component (C): 5 to 50% by weight.
% By weight (however, the sum of (A), (B) and (C) is 100% by weight)
Wherein (A) is at least 30% by weight and (B) may be zero. A) a rubber member for paper feed comprising a rubber composition containing (A) 20 to 120 parts by weight of extender oil is added during the production process to 100 parts by weight of ethylene / propylene copolymer rubber.
Oil extended ethylene-propylene copolymer rubber; (B) the non-oil extended ethylene-propylene copolymer rubber; (C) the average compositional formula _{RnSiO (4-n) / 2} ( wherein, in R is a substituted or unsubstituted one Represents a monovalent hydrocarbon group, n is 1.98 to 2.05
Represents the number of A) an organopolysiloxane having at least two aliphatic unsaturated bonds and / or mercapto groups in one molecule; 2. The rubber member according to claim 1, wherein the rubber member is a rubber roll.