JP4469386B2 - Method for improving adhesion durability of fluororesin-based coated fixing roll - Google Patents

Description

  The present invention relates to a liquid addition-curable silicone rubber composition for a fluororesin-based fixing roller used in a copying machine, a laser beam printer, a fax machine, and the like, and a fluororesin-coated fixing roller having a silicone rubber layer made of a cured product of the composition About.

  Conventionally, silicone rubber has been used for fixing rolls used in copying machines, laser beam printers, fax machines, and the like. This is because the release properties, heat resistance, compression set and the like of silicone rubber are superior to other rubber materials. However, recently, with the speeding up of this type of equipment, an oil fuse that supplies silicone oil (so-called fuser oil) to the roll surface has been used to improve the toner releasability. In order to increase the time required for the rubber material, the hardness of the rubber material has been reduced for the purpose of securing the fixing width (nip width).

  However, since silicone rubber is originally the same material as silicone oil, there is a problem that when the hardness is lowered, the silicone rubber is swollen by the fused silicone oil. As a method for solving these problems, a roll surface made of low hardness silicone rubber or silicone rubber foam is covered with a flexible film made of fluororubber latex or fluororesin tube. . This coating significantly improved the life of the fixing roll. However, as the speed of the equipment increased, the adhesive interface between the silicone rubber and fluororesin tube or fluororubber latex or silicone rubber and the cylindrical metal core became hot and deformed. The reality is that it cannot withstand the stresses generated for a long time.

  The present invention has been intensively studied in view of the above situation, and the problem is that a fluororesin coating layer (surface) comprising a fluorocoating agent such as fluororubber latex or a fluororesin tube such as PFA, PTFE, or FEP. A liquid addition-curing silicone rubber composition for a fluororesin-based coating roll that has a release layer) and silicone rubber or a metal core and silicone rubber bonded to each other and does not easily peel even after long-term use, and a cured product of the composition Another object of the present invention is to provide a fixing roll having a silicone rubber layer.

That is, the present invention provides a means for solving the above problems.
(A) 100 parts by weight of an organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in the middle of the molecular chain in the molecule;
(B) an organohydrogenpolysiloxane having at least two hydrogen atoms directly bonded to a silicon atom (a) an alkenyl group bonded to a silicon atom in the component (b) a silicon atom-bonded hydrogen atom in the component An amount in which the molar ratio is 0.4 to 5.0,
(C) an effective amount of a platinum-based catalyst;
(D) 0.1 to 10 parts by weight of dry silica, and (e) 0.05 to 5 parts by weight of a cyclic diorganopolysiloxane containing an alkenyl group bonded to at least three silicon atoms in one molecule. A liquid addition-curable silicone rubber composition for a fluororesin-based coating fixing roll is provided.

  The present invention also relates to a fixing roll having a cored bar, a silicone rubber layer provided directly or indirectly on the outer periphery thereof, and a fluororesin layer (surface release layer) formed on the silicone rubber layer. A fluororesin-based coating fixing roll is provided, wherein the silicone rubber layer is a cured product of the liquid addition-curable silicone rubber composition according to claim 1.

  According to the liquid addition-curable silicone rubber composition for a fluororesin-based coating roll of the present invention, a silicone rubber layer and a metal core in a fixing roll comprising a metal core, a silicone rubber layer, and a fluorine-based coating or a fluororesin-based tube. In addition, good adhesion can be brought about between the resin layer and the fluororesin layer, and the obtained adhesion is excellent in durability and hardly peels even after long-term use.

Hereinafter, the silicone composition of this invention is demonstrated for every component.
-Component (a): Organopolysiloxane-
The component (a) used in the present invention is the main component of the present composition, and silicon atoms in the middle of the molecular chain (that is, in the middle of the siloxane chain excluding the terminal siloxane units constituting the main chain of the organopolysiloxane molecule). An alkenyl group bonded to a silicon atom (that is, a bifunctional siloxane unit or a trifunctional siloxane unit represented by R ₂ SiO _2/2 or RSiO _3/2 (R represents an unsubstituted or halogen-substituted monovalent carbonization described later) It is an organopolysiloxane having at least two alkenyl groups as so-called side chain substituents bonded to silicon atoms of hydrogen groups. The molecular structure of the organopolysiloxane is preferably substantially linear, but may have a slightly branched molecular structure.

  This organopolysiloxane has the general formula (1):

（式中、Ｒは非置換又はハロゲン置換の１価炭化水素基であり、Ｒ^１は脂肪族不飽和二重結合を有しない非置換又はハロゲン置換の１価炭化水素基であり、Ｒ^２はアルケニル基であり、ｎは２以上の整数であり、ｍは０又は１以上の整数である。）
で表されるものが好ましい。

Wherein R is an unsubstituted or halogen-substituted monovalent hydrocarbon group, R ¹ is an unsubstituted or halogen-substituted monovalent hydrocarbon group having no aliphatic unsaturated double bond, and R ² is An alkenyl group, n is an integer of 2 or more, and m is an integer of 0 or 1)
The thing represented by these is preferable.

Examples of the unsubstituted or halogen-substituted monovalent hydrocarbon group represented by R in the general formula (1) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and a tert-butyl group. , Alkyl groups such as pentyl group, hexyl group, cyclohexyl group, alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group, aryl groups such as phenyl group, tolyl group, xylyl group, benzyl group, phenylethyl group, etc. And those having about 1 to 12 carbon atoms, preferably about 1 to 10 carbon atoms, such as halogenated alkyl groups such as aralkyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, etc. The R ¹ is an unsubstituted or halogen-substituted, except for these unsubstituted or halogen-substituted monovalent hydrocarbon groups, a group having an aliphatic unsaturated double bond such as an alkenyl group such as a vinyl group or an allyl group. It is a monovalent hydrocarbon group. Among these, R and R ¹ are preferably methyl groups. R ² is usually an alkenyl group having about 2 to 6 carbon atoms such as vinyl, allyl, propenyl, butenyl, hexenyl and the like. n is an integer of 2 or more, m is an integer of 0 or 1, and m + n is usually an integer of about 20 to 2,000, preferably about 50 to 1,000. Further, n / (m + n) is preferably about 0.001 to 0.2, particularly about 0.002 to 0.1.

  The viscosity of component (a) at 25 ° C. is 1,000 mPa.s. s (millipascal · second) or more, preferably 1000 to 1,000,000 mPa.s. The range of s is preferable.

  Specific examples of the component (a) include, for example, a trimethylsiloxy group-capped dimethylsiloxane / methylvinylsiloxane copolymer, a dimethylvinylsiloxy group-capped dimethylsiloxane / methylvinylsiloxane copolymer, and a trimethylsiloxy group-capped both terminals. Methyl vinyl siloxane / diphenyl siloxane copolymer, both ends dimethyl vinyl siloxy group-blocked methyl vinyl siloxane / diphenyl siloxane copolymer, both ends trimethyl silyl group blocked dimethyl siloxane / methyl vinyl siloxane / diphenyl siloxane copolymer, both ends dimethyl vinyl siloxy Capped dimethylsiloxane / methylvinylsiloxane / diphenylsiloxane copolymer, trimethylsilyl group-capped methylvinylsiloxane / methylphenylsiloxane copolymer Etc., and the like. These can be used singly or in combination of two or more.

-Component (b): Organohydrogenpolysiloxane-
The organohydrogenpolysiloxane of component (b) used in the present invention is a hydrosilylation addition reaction between an alkenyl group in which a hydrogen atom (SiH group) bonded to a silicon atom in the molecule is bonded to a silicon atom in component (a). And acts as a crosslinking agent. The molecular structure of the organohydrogenpolysiloxane is not particularly limited, and conventionally known structures having various structures such as linear, cyclic, and branched three-dimensional networks can be used. It is necessary to include a hydrogen atom (that is, SiH group) directly bonded to at least two silicon atoms. As the organohydrogenpolysiloxane of component (b), those represented by the following average composition formula (2) are preferably used.

R ³ _b H _c SiO _{(4-b-c) / 2} (2)
(R ³ is an unsubstituted or substituted monovalent carbon hydrogen group having 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms excluding aliphatic unsaturated compounds, and b and c are 0.7 ≦ b ≦ 2.1, respectively. 1 ≦ b ≦ 2, 0.002 ≦ c ≦ 1, preferably 0.01 ≦ c ≦ 0.6, 0.8 ≦ b + c ≦ 3, preferably 1.5 ≦ b + c ≦ 2.6 Is a positive number.)

In this organohydrogenpolysiloxane, the substituent R ³ bonded to a silicon atom other than a hydrogen atom is the same as those exemplified as the substituent R in the organopolysiloxane of component (a), preferably a fatty acid having 1 to 12 carbon atoms. It is a C1-C10 unsubstituted or substituted monovalent | monohydric hydrocarbon group except a group unsaturated bond.

Examples of such an organohydrogenpolysiloxane include methylhydrogen cyclic polysiloxane, trimethylsiloxy group-blocked methylhydrogenpolysiloxane at both ends, trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer at both ends, and dimethylsiloxane at both ends. Hydrogensiloxy group-blocked dimethylpolysiloxane, both ends dimethylhydrogensiloxy group-blocked methylhydrogenpolysiloxane, both ends dimethylhydrogensiloxy-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, both ends trimethylsiloxy group-blocked methylhydrogen Siloxane / diphenylsiloxane / dimethylsiloxane copolymer, a copolymer comprising (CH ₃ ) ₂ HSiO _1/2 units and SiO _4/2 units A copolymer comprising (CH ₃ ) ₂ HSiO _1/2 units, (CH ₃ ) ₃ SiO _1/2 units and SiO _4/2 units, (CH ₃ ) ₂ HSiO _1/2 units and SiO _{4 / Examples} thereof include a copolymer comprising ₂ units and (C ₆ H ₅ ) SiO _3/2 units.

  The organohydrogenpolysiloxane preferably has a viscosity of 0.1 to 1,000 mPa · s, preferably 0.1 to 500 mPa · s at 25 ° C., and the number of silicon atoms in the molecule (or polymerization) The degree) is usually 3 to 300, preferably about 4 to 150.

  The addition amount of the component (b) is such that the amount of hydrogen atoms (SiH groups) bonded to the silicon atom in the component (b) is 0 by molar ratio with respect to the silicon-bonded alkenyl group contained in the component (a). .4 to 5.0 (mol / mol), preferably in the range of 0.8 to 2.0. If this molar ratio is less than 0.4, the crosslinking density becomes too low and the heat resistance of the cured silicone rubber may be reduced. On the other hand, if it is more than 5.0, foaming due to dehydrogenation reaction is likely to occur, and the heat resistance may also be lowered.

A method for producing this organohydrogenpolysiloxane is well known to those skilled in the art, and can be easily produced by a known method according to the degree of polymerization and the molecular structure. For example, to give a very general production method, octamethylcyclotetrasiloxane and / or tetramethylcyclotetrasiloxane and hexamethyldisiloxane or 1,3-dihydro-1,1,3,3-tetramethyl which can be a terminal group A compound containing a disiloxane unit can be easily obtained by equilibrating at a temperature of about −10 to + 40 ° C. in the presence of a catalyst such as sulfuric acid, trifluoromethanesulfonic acid or methanesulfonic acid.
-Component (c): Platinum catalyst-

The platinum-based catalyst of component (c) used in the present invention has an action of promoting the curing addition reaction (hydrosilation) between the components (a), (b) and (e). As the platinum catalyst, any platinum and platinum compounds known to those skilled in the art as promoting the addition reaction can be used. For example, there are platinum black, chloroplatinic acid, alcohol-modified products of chloroplatinic acid, complexes of chloroplatinic acid and olefins, aldehydes, vinyl siloxanes, acetylene alcohols, and the like. The amount added is an effective amount as a catalyst (so-called catalyst amount), but may be appropriately increased or decreased depending on the desired curing rate. Usually, it is 0.1-1000 ppm as platinum content with respect to (a) component, Preferably it is the range of 1-200 ppm.
-Component (d): Dry silica-
The dry silica of component (d), that is, fumed silica (fumed silica) is a reinforcing filler that imparts physical strength to the cured silicone rubber, and has a BET specific surface area of 50 m ² / g or more (usually, It is preferable that it is about 50-500 m < ² > / g), and it is more preferable that it is about 100-400 m < ² > / g.

  The dry silica of component (d) used in the present invention is an essential component for adhesion durability with a fluororesin or a metal core, and examples thereof include hydrophilic silica and hydrophobic silica. As the hydrophilic silica, Aerosil 130, 200, 300 (Japan Aerosil, Degussa) Cabosil MS-5, MS-7 (Cabot) Rheorosil QS-102, 103 (Tokuyama Soda Co., Ltd.) Nipsil LP (Nihon Silica) Etc. Examples of the hydrophobic silica include Aerosil R-812, R-812S, R-972, R-974 (manufactured by Degussa) Rheorosil MT-10 (manufactured by Tokuyama Soda), Nippon SilSS series (manufactured by Nippon Silica), and the like.

The amount of component (d) is 0.1 to 10 parts by weight, preferably 0.2 to 8 parts by weight, based on 100 parts by weight of organopolysiloxane of component (a). If the amount is less than 0.1 part by weight, the resulting cured silicone rubber is often insufficiently adhered to the base material. If the amount exceeds 10 parts by weight, the compression set of the cured silicone rubber tends to decrease, and it is used at a high temperature. Does not function practically as a roll.
-Component (e): Alkenyl group-containing cyclic diorganopolysiloxane-
The cyclic diorganopolysiloxane of component (d) contains at least 3, preferably 4 or more silicon atom-bonded alkenyl groups in one molecule, and usually 3-20, preferably 4-10 diorganogroups. It consists of siloxane units and has the effect of stabilizing the initial adhesion and adhesion durability between a cured silicone rubber layer obtained by curing the composition of the present invention, a fluororesin layer and / or a metal core. . This cyclic diorganopolysiloxane is, for example, the general formula (3):

（式中のＲ^４は独立に脂肪族不飽和二重結合を有しない非置換又はハロゲン置換の１価炭化水素基であり、Ｒ^５はアルケニル基であり、ｍは３〜２０の整数であり、ｎは０〜１７の整数であり、但しｍ＋ｍは３〜２０の整数である。）
で表されるものが好ましい。

(In the formula, R ⁴ is an unsubstituted or halogen-substituted monovalent hydrocarbon group independently having no aliphatic unsaturated double bond, R ⁵ is an alkenyl group, and m is an integer of 3 to 20. , N is an integer of 0 to 17, provided that m + m is an integer of 3 to 20.)
The thing represented by these is preferable.

In the general formula (3), the unsubstituted or halogen-substituted monovalent hydrocarbon group which does not contain an aliphatic unsaturated double bond as R ⁴ can be the same as R ¹ , for example, methyl Group, alkyl group such as ethyl group and propyl group, aryl group such as phenyl group, tolyl group and xylyl group, and haloalkyl group such as 3-chloropropyl group, 3,3,3-trifluoropropyl group, etc. , Methyl group, and phenyl group are preferable. The alkenyl group represented by R ⁵ may be the same as R ² described above, and examples thereof include a vinyl group, an allyl group, and a butenyl group, and a vinyl group is preferable. m is an integer of 3 to 20, and preferably an integer of 4 to 8. Moreover, n is an integer of 0-17, Preferably, it is an integer of 0-5. M + n in the above formula is an integer of 3-20, preferably an integer of 4-10.

  Such components (e) include 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetra. In addition to cyclic methylvinylpolysiloxane such as vinylcyclotetrasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-pentavinylcyclopentasiloxane, 1,3,5,7 , 7-pentamethyl-1,3,5-trivinylcyclotetrasiloxane, and the like, and cyclic methylvinylsiloxane / dimethylsiloxane copolymer, cyclic methylvinylsiloxane / phenylmethylsiloxane copolymer, and the like. These cyclic diorganosiloxanes may be used alone or in combination of two or more.

  The cyclic diorganopolysiloxane of the component (e) participates in the addition curing reaction together with the components (a) and (b), and at least two of the silicon-bonded alkenyl groups contained in the molecule then undergo the addition reaction. Participating and contributing to curing, the remaining alkenyl groups are thought to be involved in adhesion. However, since this component is in a liquid state, it is difficult to act as an adhesion active point unless it is used together with the component (c).

The amount of component (e) is in the range of 0.05 to 5 parts by weight with respect to 100 parts by weight of component (a). If the amount exceeds 5 parts by weight, the physical properties of the silicone rubber are changed and the adhesiveness is adversely affected.
-Other ingredients-
In the composition of the present invention, other additives can be blended as necessary, as long as the functions and effects of the present invention are not impaired. Examples of such arbitrarily blended components include the following.

  In order to increase physical strength such as hardness and tensile strength of the cured product and adhesion durability with the fluororesin-based coating layer, examples of the filler used include crystalline silica and quartz. A single species or a combination of two or more species may be used. As an example of such a material, crystallites include crystallite and Minusil Isil. The compounding amount of such a reinforcing filler may be 300 parts by weight or less (that is, 0 to 300 parts by weight) with respect to 100 parts by weight of the component (a), and is preferably 5 to 300 parts by weight, more preferably 20 to 200 parts by weight.

If it is necessary to adjust the curing time, triallyl isocyanurate, alkyl maleate, acetylene alcohols and their silane or siloxane modifications, hydroperoxide, tetramethylethylenediamine, benzotriazole and mixtures thereof as a control agent You can use it.
Furthermore, non-reinforcing fillers such as diatomaceous earth and calcium carbonate, inorganic pigments such as cobalt blue, colorants such as organic dyes, heat resistance and flame resistance such as cerium oxide, zinc carbonate, manganese carbonate, titanium oxide, and carbon black Addition of an improver, etc. is also possible.

  The metal core used for manufacturing the roll may be made of any material such as iron, aluminum, and stainless steel. Moreover, you may use the metal core metal which gave the primer process. Commercially available fluorine latex coating (for example, polytetrafluoroethylene) and fluorine resin tube polyimide resin tube used above are used, and the fluororesin tube is preferably tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA). Silicone rubber The contact surface is preferably treated with a corona discharge treatment, sodium naphthalene method, sputter etching method, liquid ammonia method or the like so as to be advantageous for adhesion to the silicone rubber. Furthermore, primer treatment may be used to improve the adhesion durability.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example 1:
100 parts by weight of a linear dimethylsiloxane polymer (degree of polymerization of about 700) containing both sides of the molecular chain blocked with trimethylsiloxy groups and containing an average of about 5 side chain vinyl groups as methylvinylsiloxane units, dry silica (fumed) 2 parts by weight of Aerosil R-972 (manufactured by Degussa) and 0.1 part by weight of cyclic methylvinylpolysiloxane represented by the following formula (i) are uniformly mixed as silica), and then represented by the following formula (ii). 3.0 parts by weight of a trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer with both ends of the molecular chain, 0.1 parts by weight of 1-ethynyl-1-cyclohexanol as a reaction control agent, platinum vinylsiloxane complex as platinum 50 ppm as an atom was added and mixed well until uniform to obtain a silicone rubber composition 1.

Evaluation of shear adhesiveness at 120 ° C. to the aluminum and PFA resin films of the silicone rubber composition 1 was performed according to the following method.
<Shearing adhesive evaluation method>
Primer X-33-173A / B (manufactured by Shin-Etsu Chemical Co., Ltd.) is brushed on two aluminum metal sheets 1 and 2 each having a thickness of 0.3 mm, a width of 25 mm, and a length of 100 mm. Dried for minutes. The two metal sheets coated with the primer are fixed to a tensile shear adhesion test piece preparation jig, an appropriate amount of the silicone rubber composition 1 is poured into the jig, and heated and cured in a 120 ° C. constant temperature bath for 60 minutes, as shown in FIG. Thus, a test sample in which the aluminum metal sheets 1 and 2 as adherends were bonded via the silicone rubber layer 3 was prepared. Both ends 4 and 5 of this test sample were pulled in the opposite direction at a speed of 50 mm / min, and the cohesive failure rate of the rubber layer 3 in the bonded portion at that time was measured. A PFA resin film having a thickness of 100 μ, a width of 25 mm, and a length of 100 mm was also measured in the same manner as described above.
The cohesive failure rate of both aluminum and PFA resin films was 100%.

Comparative Example 1:
The silicone composition C-1 was blended in the same manner as in Example 1 except that no cyclic methylvinylpolysiloxane was blended in Example 1, and the shear adhesion evaluation for aluminum and PFA resin film was measured in the same manner as in Example 1. Both the aluminum and PFA resin films had a cohesive failure rate of 50%.

Comparative Example 2:
The silicone composition C-2 was blended in the same manner as in Example 1 except that Aerosil R-972 (made by Degussa), which is dry silica, was not blended in Example 1, and the shear adhesion evaluation for aluminum and PFA resin film was performed. Measurement was performed in the same manner as in Example 1. Both the aluminum and PFA resin films had a cohesive failure rate of 50%.

Comparative Example 3:
The silicone composition C-3 was blended in the same manner as in Example 1 except that 7 parts by weight of cyclic methylvinylpolysiloxane was blended in Example 1, and the shear adhesion evaluation for aluminum and PFA resin film was conducted in the same manner as in Example 1. It was measured. The cohesive failure rate for both aluminum and PFA resin films was 60%.

Comparative Example 4:
Silicone composition C-4 was blended in the same manner as in Example 1 except that 30 parts by weight of pulverized quartz fine powder having an average particle size of 5 μm was blended in place of dry silica in Example 1, and aluminum and PFA resin were blended. Evaluation of shear adhesion to the film was measured in the same manner as in Example 1. Both the aluminum and PFA resin films had a cohesive failure rate of 50%.

Example 2:
Both ends of the molecular chain are blocked with trimethylsiloxy groups, and 100 parts by weight of a linear dimethylsiloxane polymer (degree of polymerization of about 700) containing an average of about 5 side chain vinyl groups as methylvinylsiloxane units, Aerosil R- as dry silica 8 parts by weight of 972 (manufactured by Degussa), 30 parts by weight of fine pulverized quartz powder having an average particle size of 5 μm, and 4 parts by weight of cyclic methylvinylpolysiloxane represented by the above formula (i) were uniformly mixed. Thereafter, 3.0 parts by weight of a trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer with both ends of the molecular chain represented by the above formula (ii), 0.1-ethynyl-1-cyclohexanol 0.1 as a reaction control agent Part by weight, 50 ppm of platinum vinylsiloxane complex as a platinum atom is mixed well until uniform, and silicone rubber composition 2 Obtained.

  The silicone rubber composition 2 was evaluated for shear adhesion to aluminum and a PFA resin film at 120 ° C. in the same manner as in Example 1. The cohesive failure rate of both aluminum and PFA resin films was 100%.

Example 3:
Primer NO. For addition reaction type liquid silicone rubber on an aluminum shaft having a diameter of 10 mm and a length of 300 mm. 101 A / B (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied. In the mold, a PFA resin tube having a thickness of 50 μm whose inner surface was primed and the shaft were placed in the same circular shape, and the liquid composition 1 prepared in Example 1 was filled between the two, and 150 ° C. For 30 minutes and then post-cured at 200 ° C. for 4 hours. A PFA resin-coated silicone rubber roll having an outer diameter of 14 mm and a length of 250 mm was produced.

  Furthermore, when it was incorporated into a PPC copying machine as a fixing roll and copied on 100,000 sheets of paper, good copies were obtained, and the adhesion between silicone rubber and PFA tube and between silicone rubber and aluminum core was good. I understood.

Comparative Example 5:
A PFA resin-coated silicone rubber roll having an outer diameter of 14 mm and a length of 250 mm was prepared in the same manner as in Example 3 except that the liquid composition C-1 obtained in Comparative Example 1 was used instead of the composition 1.

  As a fixing roll was incorporated into a PPC copying machine and copied, the silicone rubber layer and the PFA tube were peeled off when 30,000 sheets were copied.

Comparative Example 6:
A PFA resin-coated silicone rubber roll having an outer diameter of 14 mm and a length of 250 mm was prepared in the same manner as in Example 3 except that the liquid composition C-2 obtained in Comparative Example 2 was used instead of the composition 1.

  As a fixing roll of a PPC copying machine, copying was performed, and when 50,000 copies were made, the silicone rubber layer and the PFA tube were peeled off.

Comparative Example 7:
A PFA resin-coated silicone rubber roll having an outer diameter of 14 mm and a length of 250 mm was prepared in the same manner as in Example 3 except that the liquid composition C-4 obtained in Comparative Example 4 was used instead of the composition 1.
Further, as a fixing roll of a PPC copying machine, copying was performed, and when the 50,000 copies were made, the silicone rubber layer and the aluminum core metal were peeled off.

Example 4:
In the same manner as in Example 3, the liquid composition 2 obtained in Example 2 was used on an aluminum shaft having a diameter of 10 mm and a length of 300 mm and cured by heating at 150 ° C. for 30 minutes and further post-cured at 200 ° C. for 4 hours. A silicone rubber layer was formed. Daiel latex and silicone rubber primer GLP-103SR (manufactured by Daikin) are uniformly applied to the surface of the cured product, heated at 80 ° C. for 10 minutes, and further, Daiel latex GLS-213 is spray-applied uniformly at 300 ° C. And baked for 1 hour. Thus, a Daiel latex-coated silicone rubber roll having an outer diameter of 14 mm and a length of 250 mm was produced.
Furthermore, as a fixing roll of a PPC copying machine, when 100,000 copies were made, good copies were obtained, and the adhesion between silicone rubber and Daiel latex coating and between silicone rubber and aluminum core was good. .

Comparative Example 8:
In Example 1, silicone composition C-8 was blended in the same manner as in Example 1 except that 12 parts by weight of Aerosil R-972 (Degussa) was blended as dry silica.

Next, a die latex coated silicone rubber roll having an outer diameter of 14 mm and a length of 250 mm was prepared in the same manner as in Example 4 except that the composition C-8 was used instead of the liquid composition 2.
When this was incorporated as a fixing roll for a PPC copying machine and 10,000 copies were made, a copy with uneven fixing was obtained, and dents were generated in various places on the roll between the silicone rubber layer and the Daiel latex coating. Some peeling occurred.

Comparative Example 9:
100 parts by weight of a linear dimethylsiloxane polymer having a dimethylvinylsiloxy group-blocked at both ends (degree of polymerization: about 500), 2 parts by weight of Aerosil R-972 (manufactured by Degussa) as dry silica, and represented by the above formula (i) After uniformly mixing 0.1 part by weight of the cyclic methylvinylpolysiloxane, the dimethylsiloxane / methylhydrogensiloxane copolymer 3.0 blocked with a trimethylsiloxy group-blocked trimethylsiloxy group represented by the above formula (ii) Part by weight, 0.1 part by weight of 1-ethynyl-1-cyclohexanol as a reaction control agent, and 50 ppm of platinum vinylsiloxane complex as platinum atoms were mixed well until uniform, and silicone rubber composition C-9 was obtained.

The silicone rubber composition C-9 was evaluated for shear adhesion to aluminum and a PFA resin film in the same manner as in Example 1 at 120 ° C. The cohesive failure rate for both aluminum and PFA resin films was 60%.
Furthermore, NO. For addition reaction type liquid silicone rubber is formed on an aluminum shaft having a diameter of 10 mm and a length of 300 mm. 101 A / B (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied. Inside the mold, a 50 μm PFA tube whose inner surface was primed and the shaft were placed concentrically, and the silicone rubber composition C-9 was filled between the two and cured at 150 ° C. for 30 minutes. Further, post-curing was performed at 200 ° C. for 4 hours. A PFA resin-coated silicone rubber roll having an outer diameter of 14 mm and a length of 250 mm was produced.
Further, as a fixing roll of a PPC copying machine, copying was performed, and when 30,000 copies were made, the silicone rubber layer and the PFA tube were peeled off.

It is a test sample perspective view used for a shear adhesiveness evaluation method.

Explanation of symbols

1, 2: Aluminum metal sheet 3: Silicone rubber layer 4, 5: Both ends of test sample

Claims (2)

In a fixing roll having a core metal, a silicone rubber layer provided on the outer periphery thereof, and a fluororesin-based layer formed on the silicone rubber layer, the silicone rubber layer includes the following components (a) to (f): A method for improving the adhesive durability of a fluororesin-based coated fixing roll, comprising forming a cured product of a liquid addition-curable silicone rubber composition comprising:
(a) 100 parts by weight of an organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in the middle of the molecular chain,
(b) Organohydrogenpolysiloxane having at least two hydrogen atoms directly bonded to silicon atoms in one molecule
(a) an amount such that the molar ratio of silicon atom-bonded hydrogen atoms in component (b) to alkenyl groups bonded to silicon atoms in component is 0.4 to 5.0,
(c) an effective amount of a platinum-based catalyst;
(d) 0.1 to 10 parts by weight of dry silica,
(e) 0.05 to 5 parts by weight of a cyclic diorganopolysiloxane containing an alkenyl group bonded to at least 3 silicon atoms in one molecule, and
(f) 1-ethynyl-1-cyclohexanol .   2. The fluorine according to claim 1, wherein a liquid addition-curable silicone rubber composition containing the components (a) to (f) is prepared, and the composition is heated and cured to form a silicone rubber layer on the core metal. A method for improving the adhesion durability of a resin-coated fixing roll.

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