JP2001011264A - Electrically conductive composition and electrically conductive roller produced therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrically conductive composition and a low hardness, electrically conductive roller produced from the composition. SOLUTION: This electrically conductive composition comprises (A) a polyisobutylene polymer having at least one alkenyl group capable of undergoing hydrosilylation reaction in the molecule, (B) a compound having at least two hydrosilyl groups in the molecule, (C) an electrical conductivity-imparting material, (D) a hydrosilylating catalyst and (E) a plasticizer. The alkenyl group capable of undergoing hydrosilylation reaction in the polymer of the component A is preferably present at the end of the polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive composition and a conductive rubber roller made from the conductive composition. Specifically, the conductive composition of the present invention includes a polyisobutylene-based polymer having at least one alkenyl group capable of performing a hydrosilylation reaction in a molecule, a compound having at least two hydrosilyl groups in a molecule, and a hydrosilylation compound. The present invention relates to an addition-type curable conductive composition containing a catalyst, a plasticizer, and a conductivity-imparting substance, and a low-hardness conductive rubber roller obtained therefrom.

[0002]

2. Description of the Related Art One application of a conductive composition is various rollers of an electrophotographic machine or a printer, for example, for feeding paper. EPDM, urethane, NBR, silicone, and the like are often used as materials used for the elastic portion of these rollers.

A conductive composition using a saturated hydrocarbon polymer or a polyoxyalkylene polymer is known, and is disclosed in, for example, JP-A-8-262866. However, the hardness of such a conductive material is not always sufficiently low, and a rubber roller having a lower hardness has been desired.

[0004] However, in applications such as rollers for electrophotographic machines, it is required that the above materials have low hardness, which is not normally possessed, as physical properties.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a conductive rubber roller of low hardness which does not affect a printed image due to contamination of a photoreceptor of an electrophotographic machine or the like, and a conductive material therefor. Aim.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have developed a polyisobutylene-based polymer having an alkenyl group capable of undergoing a hydrosilylation reaction, and a curable material containing a curing agent having a hydrosilyl group, a hydrosilylation catalyst, and a conductivity-imparting substance. The present inventors have found that a conductive composition for a rubber roller having a low hardness can be obtained by adding a plasticizer to the present invention, thereby completing the present invention.

The conductive composition of the present invention comprises the following components (A) to (E): (A) a polyisobutylene-based polymer having at least one alkenyl group capable of hydrosilylation in a molecule; B) a compound having at least two hydrosilyl groups in the molecule; (C) a conductivity-imparting substance; (D) a hydrosilylation catalyst; and (E) a plasticizer.

In one embodiment, the alkenyl group capable of undergoing a hydrosilylation reaction in the polymer of the component (A) is
Located at the end of the polymer.

[0009] In one embodiment, the total amount of repeating units derived from isobutylene in the polymer of the component (A) is 50% by weight or more.

[0010] In one embodiment, the compound of component (B) is a polyorganohydrogensiloxane containing on average two or more hydrosilyl groups in one molecule.

In one embodiment, the amount of silicon-bonded hydrogen atoms in the compound of the component (B) is 0.8 to 5 equivalents relative to the amount of the compound of the component (A).

[0012] In one embodiment, the plasticizer of the component (E) is a saturated hydrocarbon-based process oil.

In one embodiment, the component (C) is carbon black.

In one embodiment, the hardness (JIS A) of a cured product obtained by curing the conductive composition is 25.
° or less.

According to another aspect of the present invention, there is provided a conductive rubber roller obtained by curing any of the above-described compositions.

In one embodiment, the roller resistance is between 10 ^{7 and} 10 ¹¹ Ω.

In one embodiment, the roller resistance is between 10 ^{3 and} 10 ⁹ Ω.

In one embodiment, the roller resistance is between 10 ^{5 and} 10 ¹⁰ Ω.

In another aspect of the present invention, there is provided a method for producing a conductive rubber roller, comprising a step of curing any one of the above compositions.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The component (A) used in the composition of the present invention comprises at least one compound capable of undergoing a hydrosilylation reaction in a molecule.
It is a polyisobutylene polymer having two alkenyl groups. Here, the polyisobutylene-based polymer means a polymer in which the monomer units constituting the polymer skeleton are mainly composed of isobutylene units.

The polyisobutylene-based polymer can be produced by a known method by polymerizing isobutylene as a main raw material. For example, JP-A-8-134
220 or JP-A-9-71611.

Specifically, the polyisobutylene-based polymer can be obtained by polymerizing isobutylene alone or copolymerizing it with a copolymerizable monomer. Alternatively, it can also be obtained by a method such as a method of adding hydrogen after copolymerizing isobutylene and a diene-based compound.

The polyisobutylene-based polymer has a number average molecular weight (GPC method, calculated as polystyrene) of 500 to 100.
About 000, and a number average molecular weight of 1,000 to 400.
A liquid material of about 00 is particularly preferred from the viewpoint of fluidity, ease of handling, and the like.

The polyisobutylene-based polymer may be composed entirely of monomer units of isobutylene, or may be a polymer obtained by copolymerizing a monomer having copolymerizability with isobutylene. When such a copolymerizable monomer is contained, its content is preferably 50% by weight or less, more preferably 30% by weight or less, particularly preferably 20% by weight in the polyisobutylene-based polymer.
It is as follows.

Examples of the monomer having copolymerizability with isobutylene include olefins having 4 to 12 carbon atoms, vinyl ethers, aromatic vinyl compounds, vinyl silanes, allyl silanes and the like.

Specific examples of monomers copolymerizable with isobutylene include, for example, 1-butene, 2-butene,
-Methyl-1-butene, 3-methyl-1-butene, pentene, 4-methyl-1-pentene, hexene, vinylcyclohexane, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, styrene, α-methylstyrene, dimethylstyrene, p -T-butoxystyrene, p-hexenyloxystyrene, p-allyloxystyrene, p-hydroxystyrene, β-pinene, indene, vinyldimethylmethoxysilane, vinyltrimethylsilane, divinyldimethoxysilane, divinyldimethylsilane, 1,3- Divinyl-1,1,3,3-tetramethyldisiloxane, trivinylmethylsilane, tetravinylsilane, allyldimethylmethoxysilane, allyltrimethylsilane, diallylmethoxysilane, diallyldimethylsilane , Γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, and the like.

Examples of the polyisobutylene-based polymer include, but are not limited to, butadiene, isoprene, 1,13-tetradecadiene, 1,9-decadiene, 1,7-octadiene, 1,5 A small amount of monomer units, such as polyene compounds such as hexadiene, in which double bonds remain after polymerization, preferably 10
You may make it contain in the range of the weight% or less.

The polymer of the component (A) contains an alkenyl group capable of undergoing a hydrosilylation reaction. The position where the alkenyl group is bonded to the polymer may be a side chain or a terminal of the polymer. Preferably, it is introduced at the end of the polymer. When the alkenyl group is at the terminal of the compound, there are advantages such that the effective network chain amount of the finally formed cured product is increased, the crosslinking density is increased, and a high-strength rubber-like cured product is easily obtained. .

As used herein, the term "hydrosilylation reaction" refers to a reaction in which a hydrosilyl compound is added to a double bond between carbon atoms of a compound having an alkenyl group.

The alkenyl group capable of undergoing a hydrosilylation reaction is not particularly limited as long as it is a group containing a carbon-carbon double bond which is active in a hydrosilylation reaction. Examples of such alkenyl groups include aliphatic unsaturated hydrocarbon groups such as vinyl, allyl, methylvinyl, propenyl, butenyl, pentenyl, hexenyl, cyclopropenyl, cyclobutenyl, cyclopentenyl. And a cyclic unsaturated hydrocarbon group such as a cyclohexenyl group, and a methacryl group. The component (A) desirably has 1 to 10 alkenyl groups in one molecule.

However, except for the alkenyl group capable of undergoing a hydrosilylation reaction, the skeleton of these polymers is composed of a saturated hydrocarbon substantially containing no ethylenically unsaturated bond. From the viewpoint of properties, it is particularly preferable.

The feature of the conductive composition of the present invention is that the hardness of the cured product can be easily set low. In order to easily exhibit this characteristic, it is preferable that two or more alkenyl groups are present at the molecular terminals.

The number of alkenyl groups is appropriately selected depending on the desired performance of the roller. If the number of alkenyl groups is too large, the cured product tends to be rigid, and it is difficult to obtain good rubber elasticity. If the number of alkenyl groups is too small, the conductive composition will not be sufficiently cured.

In preparing the polymer of the component (A), the method of introducing an alkenyl group is roughly classified into:
There are a method of introducing an alkenyl group after polymerization of a polymer and a method of introducing an alkenyl group during polymerization.

First, a method for introducing an alkenyl group after polymerization of a polymer will be described.

As a method for introducing an alkenyl group after polymerization, for example, a polymer having a hydroxyl group at a terminal or a side chain is used, and the hydroxyl group of this polymer is converted into a group such as -ONa or -OK to obtain an alkoxide. Then, there is a method of reacting an organic halogen compound.

As a method for converting the hydroxyl group of the polymer into an oxymetal group, the polymer is converted into an alkali metal such as Na or K, a metal hydride such as NaH, a metal alkoxide such as NaOCH ₃ , or a caustic alkali such as caustic soda or caustic potash. A reaction method may be used.

Organic reacting with polymer alkoxide
The halogen compound is represented, for example, by the following general formula (1).
Re: CH_Two= CH-R⁴¹-Y (1) Here, Y is a halogen atom such as a chlorine atom or an iodine atom.
Child and R⁴¹Is -R⁴²-, -R⁴²-OC (= O)
-Or -R⁴²A divalent organic group represented by -C (= O)-
Where R⁴²Is a divalent hydrocarbon having 1 to 20 carbon atoms
Elementary group. R ⁴²Is preferably an alkylene group,
An alkylene group, an arylene group, and an aralkylene group.

Preferably, R ⁴¹ is a methylene group or

[0040]

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(R ⁴³ is a hydrocarbon group having 1 to 10 carbon atoms).

Specific examples of the organic halogen compound represented by the general formula (1) include, for example, allyl chloride, allyl bromide, vinyl (chloromethyl) benzene, allyl (chloromethyl) benzene, allyl (bromomethyl) benzene, Chloromethyl) ether, allyl (chloromethoxy) benzene, 1-hexenyl (chloromethoxy) benzene, and allyloxy (chloromethyl) benzene, and the like. Of these, allyl chloride is preferred because of its low cost and ease of reaction.

According to such a method, an alkenyl group-containing polymer having substantially the same molecular weight as the hydroxy group-containing polymer used as a starting material can be obtained.

On the other hand, when it is desired to obtain a polymer having a higher molecular weight, methylene chloride, bis (chloromethyl) benzene, bis (chloromethyl) ether or the like is required before the reaction of the organic halogen compound of the general formula (1). Can be reacted with a polyvalent organic halogen compound containing two or more halogen atoms in one molecule to increase the molecular weight. By reacting with the organic halogen compound represented by the general formula (1) after increasing the molecular weight in this way, a polymer having a higher molecular weight and having an alkenyl group (for example, a hydrogenated polybutadiene-based polymer) can be obtained. .

In one embodiment, the compound of component (A) is a polyisobutylene-based polymer. Examples of the method for preparing the polyisobutylene-based polymer include a method of introducing an alkenyl group into a polyisobutylene-based polymer having a covalent Cl group. The method of introducing an alkenyl group into a polyisobutylene-based polymer having a covalent Cl group is not particularly limited. For example, a method of performing a Friedel-Crafts reaction between alkenyl phenyl ethers and a Cl group of the polymer, allyltrimethyl A method of subjecting a silane or the like to a substitution reaction of a polymer Cl group in the presence of a Lewis acid, and various phenols and a polymer Cl group.
And a method in which a Friedel-Crafts reaction with a group is performed to introduce a hydroxyl group, and then the above-described alkenyl group introduction method is further performed.

Next, a method for introducing an alkenyl group during polymerization of the polymer will be described.

As a method for introducing an alkenyl group during the polymerization of a polymer, for example, allyltrimethylsilane is added to a reaction system for cationically polymerizing a cationically polymerizable monomer containing isobutylene in the presence of an initiator, a chain transfer agent, and a catalyst. In addition, there is a method for producing a polyisobutylene-based polymer having an allyl end.

Here, for example, as the initiator / chain transfer agent, a compound having a halogen atom and a carbon atom bonded to an aromatic ring carbon or a compound having a halogen atom bonded to a tertiary carbon atom is used. Can be used. A Lewis acid can be used as a catalyst.

Similarly, a method of adding a non-conjugated diene such as 1,9-decadiene or an alkenyloxystyrene such as p-hexenyloxystyrene to the polymerization reaction system is also possible.

Here, the catalyst is used as a cationic polymerization catalyst.
The Lewis acid to be obtained has a general formula MX'n (M is a metal source).
And a compound represented by X ′ is a halogen atom (for example,
BCl _Three, Et_TwoAlCl, EtAlCl_Two, AlCl_Three,
SnCl_Four, TiCl_Four, VCl _Five, FeCl_Three, And B
F_ThreeAnd the like, but are not limited thereto. This
Of these Lewis acids, BCl_Three, SnCl_Four, BF_ThreeWhat
And more preferably TiCl_FourIt is. Le
The amount of isocyanic acid used is based on the number of moles of initiator and chain transfer agent.
It is preferably 0.1 to 10 times, more preferably 2 to 5 times.
is there.

Next, the component (B) used in the composition of the present invention will be described.

As the compound having a hydrosilyl group as the component (B), any compound having two or more hydrosilyl groups in a molecule can be used.

In the present specification, "hydrosilyl group"
And the general _{formula: H n R (3-n} ) represented by Si- (wherein R
Is an arbitrary monovalent group) and refers to a group having a hydrogen atom bonded to a silicon atom of the silyl group. In this specification, for convenience, when two hydrogen atoms (H) are bonded to the same silicon atom (Si),
Calculate as two hydrosilyl groups.

Preferred examples of the component (B) include polyorganohydrogensiloxane. Polyorganohydrogensiloxane refers to a siloxane compound having a hydrocarbon group or a hydrogen atom on a silicon atom. The siloxane compound can be, for example, linear or cyclic, and is specifically represented, for example, by the following formula:

[0055]

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(Where 2 <m ¹ , 0 ≦ n ¹ , 2 ≦ m ¹ + n ¹ ≦ 50, and R ¹ has 2 to 2 carbon atoms.
0 hydrocarbons and R ¹ can be optionally substituted by one or more phenyl groups. Further, 0 <m ² , 0 ≦ n ² , 0 ≦ m ² + n ² ≦ 50, and R
² is a hydrocarbon having 2 to 20 carbon atoms, and R ² can be optionally substituted by one or more phenyl groups. In addition, 2 <m ³ ≦ 19, 0 ≦ n ³ <18, and 3 ≦
m ³ + n ³ ≦ 20, R ³ is a hydrocarbon having 2 to 20 carbon atoms, and R ³ may be optionally substituted by one or more phenyl groups. ) Or the siloxane compound may have two or more siloxane units, for example, represented by the following formula:

[0057]

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(Where 1 ≦ m ⁴ , 0 ≦ n ⁴ , 1 ≦ m ⁴ + n ⁴ ≦ 50, and R ⁴ has 2 to 2 carbon atoms.
0 hydrocarbons and R ⁴ can be optionally substituted by one or more phenyl groups. 2 ≦ l ¹ and R
⁵ is a divalent organic group, or R ⁵ may not be present. R ⁶ is a divalent to tetravalent organic group. Also, 0 ≦ m ⁵
0 ≦ n ⁵ , 0 ≦ m ⁵ + n ⁵ ≦ 50,
R ⁷ is a hydrocarbon having 2 to 20 carbon atoms, and R ⁷ is
It may be optionally substituted with one or more phenyl groups. 2
≦ l ² and R ⁸ is a divalent organic group or
⁸ need not be present. R ⁹ is a divalent to tetravalent organic group. Also, 1 ≦ m ⁶ , 0 ≦ n ⁶ , and 3 ≦ m ⁶ +
n ⁶ ≦ 50, R ¹⁰ is a hydrocarbon having 2 to 20 carbon atoms, and R ¹⁰ can be optionally substituted by one or more phenyl groups. A 2 ≦ l ^3, R ¹¹ is either a divalent organic group, or R ^{1 1} may be absent. R ¹²
Is a divalent to tetravalent organic group. ) The component (B) is a component (A), a component (C), a component (D),
Alternatively, those having good compatibility with the component (E) or dispersion stability in the system are preferable. In particular, when the viscosity of the entire system is low, if the compatibility of the component (B) with each of the above components is low, phase separation easily occurs, and poor curing is likely to occur. For this reason, a filler having a small particle size such as finely divided silica may be blended as a dispersing aid in order to prevent phase separation.

Specific examples of the component (B) having relatively good compatibility with the component (A), the component (C), the component (D) or the component (E) or the dispersion stability include, for example, The following compounds are mentioned.

[0060]

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(Where p is 6 to 12.
2 <k <10, 0 <j <5, and R ¹³ is a hydrocarbon group having 8 or more carbon atoms.) The amount of component (B) used is the total amount of alkenyl groups in component (A). It is preferable to use the component (B) such that the total number of moles of silicon-bonded hydrogen atoms of the component (B) is 0.8 to 5.0 equivalents. When the number of silicon-bonded hydrogen atoms in the component (B) is too small relative to the total amount of the alkenyl groups in the component (A), the crosslinking tends to be insufficient. If the amount is too large, silicon-bonded hydrogen atoms are likely to remain after curing, and the physical properties are likely to change significantly due to the influence of the hydrogen atoms. In particular, when it is desired to suppress this effect, the amount of the component (B) is preferably set to 1.0 to 2.0 equivalents.

The component (C) is a component that imparts conductivity to the composition of the present invention or a cured product obtained from the composition of the present invention. (C) As the conductivity-imparting substance of the component, an organic compound having carbon black or a metal oxide, a metal fine powder, a quaternary ammonium salt, a carboxylic acid group, a sulfonic acid group, a sulfate group, a phosphate group, or the like. Alternatively, a compound having a conductive unit represented by a polymer, an ether ester imide, or an ether imide polymer, an ethylene oxide-epihalohydrin copolymer, methoxypolyethylene glycol acrylate, or a compound such as a polymer compound such as an antistatic agent may be used.

Examples of the carbon black include furnace black, acetylene black, lamp black, channel black, thermal black, oil black and the like. There is no limitation on the type, particle size and the like of these carbon blacks.

Since the hydrosilylation reaction may be hindered depending on the type and amount of the conductivity-imparting substance, it is preferable to use a conductivity-imparting substance having little effect on the hydrosilylation reaction.

The addition amount of the component (C) can be arbitrarily selected according to the conductivity required for the obtained molded article. Preferably, it is 0.1 to 200 parts by weight, more preferably 1 to 100 parts by weight, based on 100 parts by weight of the polymer (A). If the amount is too small, the conductivity of the obtained conductive material tends to vary. On the other hand, if the amount added is too large, the fluidity of the composition tends to decrease,
Workability tends to decrease.

In one embodiment, the cured product obtained has a volume resistivity in the range of 10 ⁵ Ωcm to 10 ⁵ Ωcm.
It is added so as to be 10 ¹³ Ωcm.

In a preferred embodiment, it is added so that the range of the obtained roller resistance is 10 ⁷ to 10 ¹¹ Ω.

In another preferred embodiment, it is added so that the range of the obtained roller resistance is 10 ³ to 10 ⁹ Ω.

In yet another preferred embodiment,
The range of the obtained roller resistance is 10 ^Five-10^TenBecomes Ω
To be added.

The hydrosilylation catalyst of the component (D) is not particularly limited, and any hydrosilylation catalyst can be used. Specifically, a catalyst in which solid platinum is supported on a carrier such as chloroplatinic acid, platinum alone, alumina, silica, or carbon black; a platinum-vinylsiloxane complex {for example, Pt _n (ViMe ₂ SiOSiMe ₂ V)
i) n, Pt [(MeViSiO) _{4] m};} platinum - phosphine complex {for _{example, Pt (PPh 3) 4,} Pt (PBu
₃ ) ₄ }; platinum-phosphite complex {for example, Pt [P
(OPh) ₃ ] ₄ , Pt [P (OBu) ₃ ] ₄ (where Me is
Represents a methyl group, Bu represents a butyl group, Vi represents a vinyl group, Ph represents a phenyl group, n and m represent integers), Pt (acac) ₂ , US Pat. No. 3,159,601 to Ashby et al. No. 3,159,662 and the platinum-hydrocarbon complex described in Lamore
No. 3,220,972 to Aux et al.

Examples of catalysts other than platinum compounds include
Is RhCl (PPh_Three)_Three, RhCl _Three, Rh / Al_TwoO
_Three, RuCl_Three, IrCl_Three, FeCl_Three, AlCl_Three, P
dCl_Two・ 2H_TwoO, NiCl_Two, TiCl_FourEtc.
You. These catalysts may be used alone or in combination of two or more.
You can use it. From the viewpoint of catalytic activity, chloroplatinic acid, platinum
-Olefin complex, platinum-vinylsiloxane complex, Pt
(Acac)_TwoAre preferred.

The amount of the catalyst of the component (D) is not particularly limited, but may be 1 to 1 mol of the alkenyl group in the component (A).
The range of 0 ^-1 to 10 ^-8 mol is preferable. Preferably, 1
The range is 0 ^-2 to 10 ^-6 mol. Further, the hydrosilylation catalyst is generally expensive and corrosive, and it is preferable that the amount of the hydrosilylation catalyst be not too large because a large amount of hydrogen gas may be generated to foam the cured product.

The plasticizer (E) is a component for reducing the hardness of the obtained conductive cured product. The component (E) is not particularly limited as long as the above-mentioned object can be achieved. However, 1) the compatibility with the component (A) is good, and 2) the volatile matter is small under the curing conditions. preferable. That is, as the plasticizer of the component (E), a hydrocarbon compound having a low polarity is preferable. For example, a hydrocarbon or a hydrocarbon-substituted product may be mentioned. The plasticizer has 6 carbon atoms
These compounds are preferred, and compounds having 8 or more carbon atoms are more preferred. Specific examples of the component (E) include:
Examples include, but are not limited to, saturated hydrocarbon-based process oils having a molecular weight of 350 to 1000. (E)
The amount of the component is 1 to 100 parts by weight of the component (A).
200 parts by weight or less, preferably 5 to 150 parts by weight or less,
More preferably, it is used in an amount of 10 to 100 parts by weight or less. If the amount exceeds 200 parts by weight, problems such as bleeding tend to occur. If the amount is less than 1 part by weight, the hardness cannot be sufficiently reduced.

In the composition of the present invention, a storage stability improving agent can be used for the purpose of improving the storage stability.
As the storage stability improver, for example, a usual stabilizer known as a storage stabilizer for a compound containing a hydrosilyl group of the component (B) can be used, and is not particularly limited. Specifically, a compound containing an aliphatic unsaturated bond, an organic phosphorus compound, an organic sulfur compound, a nitrogen-containing compound, a tin compound, an organic peroxide, or the like can be preferably used. More specifically, 2-benzothiazolyl sulfide, benzothiazole, thiazole, dimethylacetylene dicarboxylate, diethylacetylene dicarboxylate, BHT, butylhydroxyanisole, vitamin E, 2- (4-morphodinyldithio) Benzothiazole, 3-methyl-1-butene-3
-All, acetylenically unsaturated group-containing organosiloxane, acetylene alcohol, 3-methyl-1-butyl-
Examples include, but are not limited to, 3-ol, diallyl fumarate, diallyl maleate, diethyl fumarate, diethyl maleate, dimethyl maleate, 2-pentenenitrile, 2,3-dichloropropene, and the like.

In the conductive composition of the present invention, a cured product having good hardness can be easily obtained by blending only the above-mentioned components (A) to (E). However, if necessary, a softener may be added for the purpose of further adjusting the hardness of the cured product. The amount of the softener used is preferably 150 parts by weight or less based on 100 parts by weight of the component (A). If the addition amount exceeds that, problems such as bleeding tend to occur.

Next, the hardness of the cured product will be described.

The hardness of the cured product is measured according to JIS K6301. Specifically, a cured product obtained by hydrosilylation of the composition of the present invention was used as a measuring instrument for A
It is measured using a mold hardness tester.

In one embodiment, the hardness of the cured product obtained by curing the composition of the present invention is 25 ° or less. The hardness of the cured product can be easily adjusted by adjusting the composition of the conductive composition of the present invention.

The conductive composition of the present invention may contain, as necessary, an adhesive or tackifier for improving the adhesion to various supports (metal core, plastic film, metal foil, paper, etc.). Resins can be added. Examples of the adhesion-imparting agent include various silane coupling agents or epoxy resins. In particular, a silane coupling agent having a functional group such as an epoxy group, a methacryloyl group, or a vinyl group has a small effect on the curability, has a large effect on the adhesiveness, and is easily used. However, usable silane coupling agents are not limited to these. These reaction catalysts may be added in combination with a silane coupling agent or an epoxy resin. In their use, the effect on the hydrosilylation reaction must be considered.

The tackifier resin is not particularly limited.
Usually, any resin used as a tackifier can be used. Specific examples include phenol resins, modified phenol resins, cyclopentadiene-phenol resins, xylene resins, cumarone resins, petroleum resins, terpene resins, terpene phenol resins, rosin ester resins, and the like. Of these, terpene resins and petroleum resins are preferred because they have particularly good compatibility and good adhesive properties.

The conductive composition of the present invention contains various fillers,
Antioxidants, ultraviolet absorbers, pigments, surfactants, solvents,
A silicon compound or the like may be appropriately added according to the required performance of the target molded article. Specific examples of the filler include fine powder of silica, calcium carbonate, clay, talc, titanium oxide, zinc white, diatomaceous earth, and barium sulfate. Among these fillers, silica fine powder, particularly fine powder silica having a particle size of about 50 to 70 nm (BET specific surface area of about 50 to 380 m ² / g) is preferable, and hydrophobic silica having been subjected to surface treatment is particularly preferable. But,
It is particularly preferable because the function of improving strength in a preferable direction is large.

The composition of the present invention is cured by, for example, an addition reaction of an Si—H group to an alkenyl group using a noble metal catalyst. Therefore, the curing speed is very fast, which is convenient for performing line production.

The composition of the present invention is molded and thermally cured by a conventionally known method to form a conductive molded article.
For example, the composition of the present invention is poured into a mold having a molding space of a desired shape such as a roller, and then heated to obtain a conductive molded product of a desired shape.

Specifically, for example, molding can be performed by liquid injection molding, extrusion molding, press molding, etc., but liquid injection molding is preferred in view of the fact that the composition is liquid and productivity.

The temperature at which the composition of the present invention is thermally cured is 8
The temperature is preferably in the range of 0 ° C to 180 ° C. When the temperature rises to about 80 ° C. or higher, the hydrosilylation reaction proceeds rapidly, and curing can be performed in a short time.

The conductive composition of the present invention is suitable as a material for producing a conductive rubber roller, and specifically includes, for example, a charging roller, a developing roller, a transfer roller, a paper feeding roller, a cleaning roller, and a fixing roller. Suitable for pressure rollers and the like.

The method for producing the above-mentioned conductive rubber roller is not particularly limited, and conventionally known various roller molding methods can be used. For example, the above-mentioned curable conductive composition is extruded, pressed, injection-molded, reaction-injection-molded (RIM), liquid injection-molded (LIMS), and the like in a mold having a metal shaft such as SUS in the center. It is molded by various molding methods such as casting, and is cured by heating at an appropriate temperature and time to form a conductive elastic layer around the shaft. In this case, the curable conductive composition may be semi-cured and then completely cured by providing a separate post-curing process. Further, if necessary, one or more layers may be provided outside the conductive elastic layer. For example, it is possible to form a surface layer by spraying or dip-coating a resin for forming a surface layer on the conductive elastic layer to apply the resin to a predetermined thickness, and to dry and cure at a predetermined temperature. it can.

The roller resistance of the conductive rubber roller is appropriately selected according to the desired roller performance. A roller having a roller resistance of 10 ⁷ to 10 ¹¹ Ω is, for example, a transfer roller having a roller resistance of 10 ³ to 1.
Those having a range of ⁰⁹ Ω can be used, for example, as a developing roller, and those having a roller resistance in a range of 10 ⁵ to 10 ¹⁰ Ω can be used, for example, as a charging roller.

The roller resistance can be adjusted to a desired range by adjusting the amount of the conductivity-imparting substance (C) in the curable conductive composition.

Here, the roller resistance means that a roller is applied horizontally to a metal plate, a load of 500 g is applied to each end of the conductive shaft of the roller in the direction of the metal plate, and a DC voltage is applied between the shaft and the metal plate. It refers to an electric resistance value measured by applying 100 volts.

[0091]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Example 1) As the component (A), an allyl-terminated polyisobutylene polymer (EP4, manufactured by Kaneka Corporation)
00A) was used. The structural formula is shown below, and the analytical values are shown in Table 1.

[0093]

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(Here, m ⁷ and n ⁷ are integers.)

[0095]

[Table 1]

First, with respect to 100 parts by weight of the component (A),
Carbon black (manufactured by Asahi Carbon Co., Ltd.)
# 35) 20 parts by weight, 50 parts by weight of a saturated hydrocarbon-based process oil (PW-380 manufactured by Idemitsu Kosan) as the component (E), and 1 part by weight of MARK AO-50 (manufactured by Asahi Denka) as an antioxidant were mixed. And kneaded three times with a roll.
Next, 5.3 parts by weight of the compound (B) having the following structure was mixed with 100 parts by weight of the component (A).

[0097]

Embedded image

Further, bis (1,3-divinyl-1,1,3,3-tetramethyldisiloxane) is used as the component (D).
A platinum complex catalyst (17.9 × 10 ⁻⁵ mmol / μl, xylene solution) was added in an amount such that platinum was 5 × 10 ⁻⁴ equivalents to the number of moles of the alkenyl group of the component (A). .
Next, 2-phenyl-3-butyn-2-ol as a storage stability improver was weighed in an amount of 300 molar equivalents with respect to platinum, and uniformly mixed. This mixture was defoamed for 15 minutes using a vacuum defoaming and stirring device (manufactured by Seatec Co., Ltd.). This mixture was filled into an aluminum mold frame on which a Teflon sheet was spread, and then heated in a hot air drier at 150 ° C. for 30 minutes to obtain a sheet-like cured product for evaluation. The hardness and volume resistivity of the obtained sheet-shaped cured product were measured at a temperature of 23 ° C. and a humidity of 65 ± 5%. Table 2 shows the recipe and the results. Further, the photoreceptor was taken out of the electrophotographic apparatus main body, and left standing for 7 days at a temperature of 50 ° C. and a humidity of 90% with the obtained sheet-shaped cured product pressed against the photoreceptor. Thereafter, the photoreceptor was returned to the electrophotographic apparatus main body, and a solid black image and a halftone image were printed. A sample having a good image was evaluated as 汚 れ, and an image having some contamination was evaluated as x. The results are shown in Table 2.

(Example 2) A sheet-like cured product was obtained in the same manner as in Example 1 except that the component (E) was changed to a saturated hydrocarbon-based process oil PW-90 (manufactured by Idemitsu Kosan). Table 2 shows the composition table and the results of the evaluation.

Example 3 A sheet-like cured product was obtained in the same manner as in Example 1, except that the component (E) was changed to a saturated hydrocarbon-based process oil PAO5006 (manufactured by Idemitsu Petrochemical). Table 2 shows the composition table and the results of various evaluations.

Comparative Example 1 A cured sheet was obtained in the same manner as in Example 1 except that the component (E) was not added. The hardness and volume resistivity of the obtained sheet-shaped cured product were measured at a temperature of 2
The measurement was performed at 3 ° C. and a humidity of 65 ± 5%. Table 2 shows the recipe and the results.

[0102]

[Table 2]

[0103]

According to the present invention, a polyisobutylene-based polymer having an alkenyl group and a hydrosilylation-addition-curable conductive composition containing a conductivity-imparting substance can be used as a storage stability improver with an aliphatic non-ionic compound. By adding a compound containing a saturated bond to the composition, a conductive composition for a conductive roller having low hardness can be obtained.

When the conductive composition of the present invention is used, a conductive rubber roller having a low hardness which does not affect a printed image due to contamination of a photosensitive member of an electrophotographic machine or the like is provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 3/04 C08K 3/04 3F049 5/00 5/00 4F071 C08L 83/05 C08L 83/05 4J002 91 / 00 91/00 5G301 G03G 15/02 101 G03G 15/02 101 15/08 501 15/08 501D 15/16 103 15/16 103 15/20 103 15/20 103 21/10 H01B 1/24 Z H01B 1 / 24 G03G 21/00 312 F term (reference) 2H003 CC05 2H032 BA08 BA13 2H033 BB29 2H034 BC03 BC04 2H077 AC04 AD06 AD14 AE04 FA22 FA25 3F049 CA13 LA02 LA05 LA07 LB02 LB03 4F071 AA21 AABB BB02 AF03 BC06 4J002 AE05Y BB18W BB20W CH04Z CH05Z CM04Z CP04X DA036 DA066 DA117 DD077 DE046 DE197 EF006 EN136 EV186 EV236 EW007 EW046 FD010 FD02Y FD030 FD11Z FD116 FD157 FD340 GM00 5G301 DA18 DA42 DD08 DD10

Claims (13)

[Claims] 1. A conductive composition comprising the following components (A) to (E): (A) a polyisobutylene-based polymer having at least one alkenyl group capable of hydrosilylation in a molecule; (B) a molecule A compound having at least two hydrosilyl groups therein; (C) a conductivity-imparting substance; (D) a hydrosilylation catalyst; and (E) a plasticizer. 2. The composition according to claim 1, wherein the hydrosilylation-reactive alkenyl group in the polymer of the component (A) is present at a terminal of the polymer. 3. The conductive composition according to claim 1, wherein a total amount of repeating units derived from isobutylene in the polymer of the component (A) is 50% by weight or more. 4. The compound of the component (B) has an average of 1
The conductive composition according to any one of claims 1 to 3, which is a polyorganohydrogensiloxane containing two or more hydrosilyl groups in a molecule. 5. The compound according to claim 1, wherein the amount of silicon-bonded hydrogen atoms in the compound of the component (B) is 0.8 to 5 equivalents relative to the amount of the compound of the component (A). Any one
Item 6. The conductive composition according to item 1. 6. The method according to claim 1, wherein the plasticizer (E) is a saturated hydrocarbon-based process oil.
Item 6. The conductive composition according to item 1. 7. The composition according to claim 1, wherein the component (C) is carbon black. 8. The composition according to claim 1, wherein a hardness (JIS A) of a cured product obtained by curing the conductive composition is 25 ° or less. 9. A conductive rubber roller obtained by curing the composition according to any one of claims 1 to 8. 10. The conductive rubber roller according to claim 9, wherein the roller resistance is 10 ⁷ to 10 ¹¹ Ω. 11. The conductive rubber roller according to claim 9, wherein the roller resistance is 10 ³ to 10 ⁹ Ω. 12. The conductive rubber roller according to claim 9, wherein the roller resistance is 10 ⁵ to 10 ¹⁰ Ω. 13. A method for producing a conductive rubber roller, comprising a step of curing the composition according to claim 1. Description: