JP2021138102A - Laminate film and method for producing laminate film - Google Patents

Abstract

To provide a laminate film which improves adhesion between a base material layer containing a polyimide resin and an elastic layer, and a method for producing a laminate film.SOLUTION: A laminate film 1 has a base material layer 2 and an elastic layer 4, in which the base material layer 2 contains a polyimide resin, a contraction ratio represented by the following expression (1) between 100-400°C when the base material layer 2 is heated in nitrogen gas environment while raising a temperature at 5°C/min within a range of 30-450°C is within a range of 0.5-3.0%, and the base material 2 and the elastic layer 4 are bonded to each other by a primer layer 3. Expression (1) Contraction ratio (%)={(Y-X)/A}×100 (In the expression, a length of the base material layer at 30°C is represented by A, a contraction length of the base material layer at 100°C is represented by X, and a contraction length of the base material layer at 400°C is represented by Y.)SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing a laminated film and a laminated film, and more particularly to a method for producing a laminated film and a laminated film having improved adhesiveness between a base material layer containing a polyimide resin and an elastic layer.

In electrophotographic and image output devices, by providing an elastic layer on a belt base material using a polyimide resin, adhesion to an output medium is improved and pressing and transferability are improved. Polyimide resin is often used as the resin material for the base material from the viewpoint of heat resistance and durability, and silicone rubber, fluorine-based rubber, or the like is often used for the elastic layer.

The base material and the elastic layer are bonded using an adhesive such as a silane coupling agent (hereinafter, also referred to as "primer"), but since the polyimide resin itself is a difficult-to-bond material, the interlayer adhesive strength is high. It tends to be weak. If the adhesive strength is weak, delamination may occur during belt drive, which may affect the image or, in the worst case, damage the belt itself. Further, there is a problem that the base material layer is warped due to shrinkage of the laminated resin or the like.

As a means for improving the adhesiveness between the belt base material and the elastic layer using a polyimide resin, a technique for forming an interlayer mixed layer between the base material layer and the elastic layer is disclosed (see, for example, Patent Document 1). ). However, it is necessary to imidize the polyimide precursor of the base material layer by heating after applying the elastic layer, and there is a problem that deterioration of the rubber contained in the elastic layer is promoted.

Further, in the laminate having the metal layer and the polyimide resin layer, the imidization rate of the polyimide resin layer is set in the range of 70 to 93%, and the flexibility of the polyimide resin layer is increased to alleviate the stress applied to the metal layer and make it durable. A technique for improving the property is disclosed (see, for example, Patent Document 2). However, this technique is a technique for improving the followability to the metal layer rather than improving the adhesiveness, and does not directly improve the adhesiveness between the layers.

Therefore, a new technique for improving the adhesiveness between the belt base material using the polyimide resin and the elastic layer is awaited.

JP-A-2019-60907 Japanese Unexamined Patent Publication No. 2001-341231

The present invention has been made in view of the above problems and situations, and the problem of solving the present invention is to provide a laminated film and a method for producing a laminated film having improved adhesiveness between a base material layer containing a polyimide resin and an elastic layer. It is to be.

The present inventor is a laminated film having a base material layer and an elastic layer in the process of examining the cause of the above problem in order to solve the above problems, and is a base material layer containing a polyimide resin in a specific temperature range. A laminated film in which the shrinkage rate of the film is within a specific range and the base material layer and the elastic layer are bonded by a primer layer, thereby improving the adhesiveness between the base material layer containing the polyimide resin and the elastic layer. Was found to be obtained.

That is, the above problem according to the present invention is solved by the following means.

1. 1. A laminated film having a base material layer and an elastic layer,
The following in the range of 100 to 400 ° C. when the base material layer contains a polyimide resin and the base material layer is heat-treated in a nitrogen gas environment while raising the temperature at 5 ° C./min in the range of 30 to 450 ° C. The shrinkage rate represented by the formula (1) is in the range of 0.5 to 3.0%, and
A laminated film characterized in that the base material layer and the elastic layer are adhered by a primer layer.
Equation (1) Shrinkage rate (%) = {(YX) / A} x 100
(In the formula, the length of the base material layer at 30 ° C. is A, the shrinkage length of the base material layer at 100 ° C. is X, and the shrinkage length of the base material layer at 400 ° C. is Y.)

2. The laminated film according to item 1, wherein the base material layer contains a polyimide resin in which a coating film containing a polyimide resin precursor is heat-imidized.

3. 3. The laminated film according to item 1 or 2, wherein the elastic layer contains silicone rubber.

4. The laminated film according to any one of items 1 to 3, wherein the glass transition temperature (Tg) of the polyimide resin is 400 ° C. or less.

5. The laminated film according to any one of items 1 to 4, wherein the laminated film is a transfer belt or a fixing belt.

6. A method for producing a laminated film according to any one of items 1 to 5, wherein the laminated film is produced.
In the step of forming the base material layer, a coating film is formed with a coating liquid containing at least a polyimide resin precursor, and the amount of residual solvent in the coating film is adjusted within the range of 20 to 35% by mass by drying. A method for producing a laminated film, which comprises a step of heating imidizing the polyimide resin precursor to form a polyimide resin.

7. Item 6 is characterized in that the liquid supply device includes a step of forming the elastic layer on the base material layer while supplying the coating liquid for forming the elastic layer to the inner surface or the outer surface of the cylindrical mold. The method for producing a laminated film according to the above.

According to the above means of the present invention, it is possible to provide a laminated film and a method for producing a laminated film in which the adhesiveness between the base material layer containing the polyimide resin and the elastic layer is improved.

Although the mechanism of expression or mechanism of action of the effects of the present invention has not been clarified, it is inferred as follows.

When forming a laminate having a base material and a functional layer, corona treatment or the like is used to improve the adhesiveness of the base material in order to increase the adhesive force between the base material and the functional layer, and the adhesion of the laminate is improved. Is usually done.

In this method, it is possible to make the surface of the base material hydrophilic by the treatment and improve the coatability, but it is difficult to uniformly increase the adhesive force over the entire base material due to variations in the treatment.

When the present inventors studied to uniformly increase the adhesive force over the entire substrate, the substrate layer was heat-treated in a nitrogen gas environment while raising the temperature at 5 ° C./min in the range of 30 to 450 ° C. After preparing a base material layer containing a polyimide resin so that the shrinkage rate represented by the above formula (1) between 100 and 400 ° C. is within the range of 0.5 to 3.0%, a primer is used. It was found that when the elastic layers were laminated via the layers, the adhesive force between the layers increased.

The fact that the base material layer shrinks in the above temperature range is considered to indicate that there are places where polycondensation of the polyimide resin with amine and acid is incomplete. It is presumed that the unfinished portion of the imide bond reacts and bonds with a primer such as a coupling agent, and as a result, the adhesive force between the base material layer and the elastic layer is improved. It is presumed that this is because the amino group and carboxy group in the molecular chain and the silanol group are chemically bonded and combined with the intermolecular binding force of the adhesive to improve the adhesive force between the layers. ..

When the shrinkage rate represented by the formula (1) is less than 0.5%, there are few unfinished portions of the imide bond, and there is no effect of improving the adhesiveness. On the other hand, if it exceeds 3.0%, there are many unfinished imide bonds, which affects the strength and dimensional accuracy of the polyimide itself.

As shown in Patent Document 2, the imidization rate is usually measured using the spectroscopic absorption spectrum of IR, but since the state in which a sufficient temperature is applied is converted as 100% imidization, the polyimide resin is clearly measured. It is difficult to show the imidization state (imidization rate) of. In that respect, it is considered that determining the range of physical properties of the base material layer by the amount of shrinkage, as in the present application, is a simple method but is in line with practical skills.

Schematic diagram showing an example of the configuration of the laminated film of the present invention Schematic diagram showing an example of the configuration of an endless belt-shaped fixing member having the laminated film of the present invention. Schematic diagram showing an embodiment of an apparatus for manufacturing an endless belt for an image forming apparatus according to the present invention. Schematic diagram showing an example of the overall configuration of an image forming apparatus applicable to the present invention.

The laminated film of the present invention is a laminated film having a base material layer and an elastic layer, in which the base material layer contains a polyimide resin and the base material layer is placed in a nitrogen gas environment at 30 to 450 ° C. The shrinkage rate represented by the above formula (1) between 100 and 400 ° C. when heat-treated while raising the temperature at 5 ° C./min is within the range of 0.5 to 3.0%, and the above-mentioned The base material layer and the elastic layer are adhered to each other by a primer layer. This feature is a technical feature common to or corresponding to the following embodiments.

In an embodiment of the present invention, from the viewpoint of exhibiting the effect of the present invention, the strength of the base material layer is that the coating film containing the polyimide resin precursor contains a polyimide resin in which the coating film is heat-imidized. , Preferable from the viewpoint of heat resistance.

Further, it is preferable that the elastic layer contains silicone rubber from the viewpoint of hardness, heat resistance, and cost.

Further, it is preferable that the glass transition temperature (Tg) of the polyimide resin is 400 ° C. or lower because it is easier to produce the polyimide resin having a low Tg from the viewpoint of producing the base material layer.

Further, it is desirable that the laminated film is a transfer belt or a fixing belt, and that the transfer belt and the fixing belt are pressed by each member and therefore have excellent interlayer adhesiveness. Hereinafter, the transfer belt and the fixing belt are also referred to as a "transfer member" and a "fixing member", respectively.

In the method for producing a laminated film of the present invention, the step of forming the base material layer is to form a coating film with a coating liquid containing at least a polyimide resin precursor, and the residual solvent amount of the coating film is 20 to 35 by drying. It is characterized by including a step of forming a polyimide resin by heating imidizing the polyimide resin precursor after adjusting the amount within the range of mass%. Further, from the viewpoint of productivity, the liquid supply device includes a step of forming the elastic layer on the base material while supplying the coating liquid for forming the elastic layer to the inner surface or the outer surface of the cylindrical mold. ,preferable.

Hereinafter, the present invention, its constituent elements, and modes and modes for carrying out the present invention will be described in detail. In the present application, "~" is used to mean that the numerical values described before and after the value are included as the lower limit value and the upper limit value.

<< Overview of the Laminated Film of the Present Invention >>
The laminated film of the present invention is a laminated film having a base material layer and an elastic layer, in which the base material layer contains a polyimide resin and the base material layer is placed in a nitrogen gas environment at 30 to 450 ° C. The shrinkage rate represented by the following formula (1) between 100 and 400 ° C. when heat-treated while raising the temperature at 5 ° C./min is within the range of 0.5 to 3.0%, and the above-mentioned The base material layer and the elastic layer are adhered to each other by a primer layer.

Equation (1) Shrinkage rate (%) = {(YX) / A} x 100
(In the formula, the length of the base material layer at 30 ° C. is A, the shrinkage length of the base material layer at 100 ° C. is X, and the shrinkage length of the base material layer at 400 ° C. is Y.)
Here, the shrinkage rate can be measured using a thermomechanical analyzer (TMA). As the thermomechanical analyzer, for example, EXSTAR TMA / SS6100 (manufactured by Hitachi High-Tech Science Corporation) can be used.

The base material with respect to the temperature represented by the above formula (1) between 100 and 400 ° C. when the base material layer is heat-treated in a nitrogen gas environment while raising the temperature at 5 ° C./min in the range of 30 to 450 ° C. Measure the maximum shrinkage rate of. The sample piece size is 4 × 15 mm (distance between chucks is 10 mm).

FIG. 1 shows an example of the structure of the laminated film of the present invention.

FIG. 1 is an example of the laminated film 1 of the present invention, and shows a typical configuration in which an elastic layer 4 is provided on a base material 2 containing a polyimide resin via a primer layer 3. A protective layer or a surface layer may be further formed on the elastic layer 4 (not shown).

The laminated film of the present invention is preferably used for a transfer member such as a transfer belt or a fixing member such as a fixing belt, and examples thereof include a roller-shaped or endless belt-shaped form.

For example, in the case of a roller-shaped fixing member in the form of a fixing member, a fixing sleeve in which the base material 2, the primer layer 3 and the elastic layer 4 containing the above-mentioned polyimide resin are supported on the outer peripheral surface of a metal cylinder. be.

FIG. 2 shows an example of the configuration of an endless belt-shaped fixing member having the laminated film of the present invention.

FIG. 2A is a schematic view showing an example of the configuration of an endless belt-shaped fixing member 10 having the laminated film of the present invention, and FIG. 2B is a schematic view showing endlessness shown in FIG. 2A. FIG. 5 is an enlarged schematic cross-sectional view of the area A described in the belt-shaped fixing member 10.

As shown in FIG. 2B, the fixing member 10 is an endless belt formed by laminating a base material layer 2, a primer layer 3, and an elastic layer 4 in this order. The fixing member 10 may be a transfer member such as an intermediate transfer belt.

Hereinafter, the components of the present invention will be described.

[Base material layer]
The base material layer according to the present invention (hereinafter, also simply referred to as “base material”) contains a polyimide resin, and the base material layer is placed at 5 ° C./40 ° C. in the range of 30 to 450 ° C. under a humidity of 50% RH. The shrinkage rate represented by the following formula (1) between 100 and 400 ° C. when heat-treated while raising the temperature in minutes is within the range of 0.5 to 3.0%, and the substrate layer. The elastic layer is bonded by a primer layer.

Equation (1) Shrinkage rate (%) = {(YX) / A} x 100
(In the formula, the length of the base material layer at 30 ° C. is A, the shrinkage length of the base material layer at 100 ° C. is X, and the shrinkage length of the base material layer at 400 ° C. is Y.)

As described above, the shrinkage of the base material layer in the above temperature range is considered to indicate that the polycondensation of the polyimide resin with amine and acid is incomplete, and the imide bond is incomplete. It is presumed that these points react and bond with a primer such as a coupling agent to improve the adhesive force between the base material layer and the elastic layer. When the heat shrinkage rate is less than 0.5%, there are few unfinished portions of the imide bond, and there is no effect of improving the adhesiveness. Further, if it exceeds 3.0%, there are many unfinished imide bonds, which affects the strength and dimensional accuracy of the polyimide itself, so it is necessary to adjust within this range.

In order to adjust to the range of the shrinkage rate, various methods such as the type of polyimide resin, the heating temperature for imidization, the heating time, the amount of residual solvent, the type of chemical imidizing agent and the amount added are adopted. However, for example, a coating film is formed with a coating solution containing a polyimide resin precursor, the amount of residual solvent in the coating film is adjusted within the range of 20 to 35% by mass by drying, and then heat imidization is performed. It is a particularly preferable example to adjust by having a step of forming the base material layer.

<resin>
The polyimide used as the resin according to the present invention is excellent in properties such as heat resistance, bending resistance, flexibility, and dimensional stability, and is particularly preferable for fixing members and transfer members. The polyimide can be obtained, for example, by synthesizing a polyamic acid (polyimide precursor) from an acid anhydride and a diamine compound, and imidizing the polyamic acid by heat or a catalyst.

For example, polyimide can be obtained by heating the precursor polyamic acid at 200 ° C. or higher, or by advancing the dehydration and cyclization (imidization) reaction by using a catalyst. The polyamic acid may be produced by dissolving tetracarboxylic dianhydride and a diamine compound in a solvent and performing a polycondensation reaction by mixing and heating, or a commercially available product may be used. Examples of the diamine compound and the tetracarboxylic dianhydride include the compounds described in paragraphs (0123) to (0130) of JP2013-25120A.

As an example, the acid anhydride used for the synthesis of polyimide is not particularly limited, and for example, biphenyltetracarboxylic acid dianhydride, terphenyltetracarboxylic acid dianhydride, benzophenone tetracarboxylic acid dianhydride, and anhydrous. Examples include aromatic tetracarboxylic acid dianhydrides such as pyromellitic acid, oxydiphthalic acid dianhydride, diphenylsulfonetetracarboxylic acid dianhydride, hexafluoroisopropyridene diphthalic acid dianhydride, and cyclobutanetetracarboxylic acid dianhydride. Be done.

The diamine compound used in the synthesis of polyimide is not particularly limited, but for example, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 4,4'-diaminodiphenylmethane, 4,4'. -Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 3,7 -Diamino-dimethyldibenzothiophene-5,5'-dioxide, 4,4'-diaminobenzophenone, 4,4'-bis (4-aminophenyl) sulfide, 4,4'-diaminobenzanilide, 1,4-bis Examples thereof include aromatic diamines such as (4-aminophenoxy) benzene.

Further, as a commercially available product, a polyimide varnish containing a polyimide precursor as a main component, for example, U-varnish S (manufactured by Ube Industries, Ltd.), Ecrios (manufactured by Mitsui Chemicals, Inc.) and the like can be used.

When an ultraviolet-transmissive polyimide is used depending on the purpose, for example, as a polyimide having a commercially available polyimide precursor (polyamic acid) as a main component, SOMAR-S, X (manufactured by IST), Spixeria HR003, GR003 (The above is manufactured by Somar), FLUPI (manufactured by NTT), Type HM (manufactured by Toyobo), Type-C (manufactured by Mitsui Chemicals), PI-100 (manufactured by Maruzen Chemicals), HDN-20D (manufactured by Shin Nihon Rika) CBDA-6FDAC (manufactured by Central Glass Co., Ltd.), Q-VR-X-1655 (manufactured by PI Giken Co., Ltd.) and the like can be used.

Further, the base material layer may contain, for example, a filler as long as the effect of the present invention is not impaired. The filler is, for example, a component that contributes to at least one performance improvement of the hardness, heat transferability and conductivity of the base material. The filler may be one kind or two or more kinds, and examples of the filler include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, and hydrated calcium silicate. , Aluminum silicate, magnesium silicate, calcium phosphate and other inorganic fine particles, and a matting agent such as a crosslinked polymer are preferably contained. Of these, silicon dioxide is preferable from the viewpoint of suppressing a decrease in transparency.

In the present invention, a resin other than polyimide can be further used as long as the effect of the present invention is not impaired, and polyamide, polyamideimide (PAI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), Examples thereof include triacetyl cellulose (TAC) and cycloolefin polymer (COP), and examples thereof include Uniamide (manufactured by Unitica), Lumirer T60 (manufactured by Toray), and Zeonex (manufactured by Zeon Corporation).

Here, the laminated film of the present invention is not particularly limited in terms of transparency and colorability, but may be preferably "colorless and transparent" depending on the intended use. “Colorless and transparent” means that when a base material layer is formed using the polyimide and the elastic layers are laminated, the total light transmittance and the yellow index value (YI value) of the film satisfy the following conditions. Defined as "colorless and transparent".

(Total light transmittance)
The total light transmittance of the laminated film sample of the present invention is a haze meter (NDH2000) in an environment of 23 ° C. and 55 RH according to JIS K-7375: 2008 for one sample whose humidity was adjusted for 24 hours in an air conditioning room at 23 ° C. and 55 RH. Measure using a mold, manufactured by Nippon Denshoku Industries Co., Ltd.) or a spectrophotometer (U-3300 manufactured by Hitachi High-Technologies Corporation).

The laminated film of the present invention is referred to as "transparent" when the thickness of the base material layer is 80 μm in dry film thickness and the total light transmittance is 70% or more in the range of light wavelengths of 395 to 420 nm, and the total light transmittance is said to be "transparent". Is more preferably 80% or more from the viewpoint of equipping the fixing member or the transfer member with the laminated film of the present invention and corresponding to a mechanism of irradiating light from the back surface, for example.

Conventionally, a polyimide resin film has excellent heat resistance, but due to its high aromatic ring density, it has a brown or yellow color and a low transmittance in the visible light region, and it has been difficult to use it in a field where transparency is required. Therefore, in the field where transparency is required, it is necessary that the YI value (yellow index: yellowish index) indicating the degree of coloring is a certain value or less, for example, the thickness of the base material layer is dry. In a sample having a film thickness of 80 μm, it is preferably 7 or less, more preferably in the range of 3 to 6, and particularly preferably in the range of 2 to 5. When the range of the YI value (7 or less) is satisfied, it is said to be practically "colorless". The range of the YI value is achieved by selecting the type of polyimide precursor and adopting and adjusting the imidization conditions.

The yellow index value can be determined according to the YI (yellow index: yellowish index) of the film defined in JIS K-7373 (2006).

As a specific method for measuring the yellow index value, a sample having a thickness of 80 μm was prepared, and the spectrophotometer U-3300 of Hitachi High-Technologies Corporation and the attached saturation calculation program were used to obtain JIS Z8701. The tristimulus values X, Y, and Z of the specified light source color are obtained, and the yellow index value is obtained according to the following equation.

Yellow index value (YI value) = 100 (1.28X-1.06Z) / Y

[Thickness and length of base material layer, etc.]
The thickness of the base material layer is not particularly limited, but is in the range of 10 to 200 μm, preferably in the range of 20 to 100 μm from the viewpoint of improving the elastic modulus, folding resistance, and durability of the belt.

The length of the base material layer is also not particularly limited, and is preferably determined by the size of the cylinder, the number of turns of the film, and the like.

[Elastic layer]
The elastic layer is a layer having desired elasticity formed on the outer peripheral surface of the base material layer.

Examples of elastic materials applicable to the present invention include elastic resin materials, which include silicone rubbers, thermoplastic elastomers and rubber materials. Above all, the elastic material is preferably silicone rubber from the viewpoint of heat resistance in addition to the desired elastic properties.

The above silicone rubber may be used alone or in combination of two or more. Examples of the silicone rubber applicable to the present invention include polyorganosiloxane or a heat-cured product thereof, and an addition reaction type silicone rubber described in JP-A-2009-122317.

As an example of the polyorganosiloxane, dimethylpolysiloxane described in JP-A-2008-255283, in which both ends are sealed with a trimethylsiloxane group and a vinyl group is provided in the side chain, can be mentioned as a typical example.

As the elastic layer, KE1356 A / B agent, which is a silicone rubber, and KE153U (all manufactured by Shin-Etsu Chemical Industry Co., Ltd.) are preferably used. If transparency is required, a transparent silicone rubber KE-2061 A / B agent (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used.

The thickness of the elastic layer is preferably in the range of 5 to 600 μm, more preferably in the range of 100 to 500 μm, for example, from the viewpoint of sufficiently exhibiting heat transferability and elasticity.

The elastic layer may further contain components other than the elastic resin material as long as the desired effect of the present invention can be obtained. For example, the elastic layer may contain a heat-conducting filler for enhancing the heat-conducting property of the elastic layer in addition to the elastic material. Examples of materials for the filler include silica, metallic silicon, alumina, zinc, aluminum nitride, boron nitride, silicon nitride, silicon carbide, carbon and graphite. The form of the filler is not limited, and is, for example, spherical powder, amorphous powder, flat powder or fibrous.

The content of the elastic resin material in the elastic material constituting the elastic layer is preferably in the range of 60 to 100% by volume, and 75 to 100% by volume, based on the total volume of the elastic layer, from the viewpoint of achieving both heat transferability and elasticity. It is more preferably%, and further preferably 80 to 100% by volume.

[Primer layer]
The primer layer (hereinafter, also referred to as an adhesive layer) contains an adhesive that adheres them between the base material layer and the elastic layer.

The thickness of the adhesive layer is preferably in the range of 0.1 μm or more and 30 μm or less.

Further, if the adhesive layer becomes too thick, the transparency of the laminated film is lowered. However, this can be prevented by setting the upper limit of the thickness to 30 μm.

Further, the adhesive layer is preferably a mixture of a filler (alumina, silica, etc.) and at least one of a thermosetting resin (epoxy resin, phenol resin, etc.).

<glue>
In the present invention, the adhesive is not particularly limited, and not only an active energy ray-curable adhesive, but also a urethane-based adhesive, an epoxy-based adhesive, an aqueous polymer-isocyanate-based adhesive, a heat-curable acrylic adhesive, and the like. Curable adhesive, moisture-curable urethane adhesive, polyether methacrylate type, ester-based methacrylate type, anaerobic adhesive such as oxidized polyether methacrylate, cyanoacrylate-based instant adhesive, acrylate and peroxide-based two-component type A known adhesive such as an instant adhesive can be used.

The pressure-sensitive adhesive may be a one-component type or a two-component type in which two or more liquids are mixed and used before use. The adhesive may be a solvent system using an organic solvent as a medium, an emulsion type, a colloidal dispersion type, an aqueous solution type or the like which is a medium containing water as a main component, or a solvent-free adhesive. It may be a mold. The concentration of the adhesive liquid may be appropriately determined depending on the film thickness after adhesion, the coating method, the coating conditions, etc., and is usually 0.1 to 50% by mass.

Further, the surface on which the adhesive is provided may be easily adhered. The easy-adhesion treatment is not particularly limited, but for example, a known method such as corona treatment or plasma treatment can be used.

(Active energy ray-curable adhesive)
The active energy ray-curable adhesive includes a cationic polymerization type and a radical polymerization type. Preferred examples of the active energy ray-curable adhesive that can be suitably used in the present invention include an active energy ray-curable adhesive composition containing each of the following components (α) to (δ).

(Α) Cationic polymerizable compound (β) Photocationic polymerization initiator (γ) Photosensitizer showing maximum absorption in light having a wavelength longer than 380 nm (δ) Naphthalene-based photosensitizer In the present invention, it is cationically polymerizable. It is preferable that the compound is cationically polymerized by irradiation with active energy rays and cured to form an adhesive layer, and a photocationic polymerization initiator (β) is blended in the active energy ray-curable adhesive composition. Is preferable.

The photocationic polymerization initiator generates a cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and initiates a polymerization reaction of the cationically polymerizable compound (α). Is. As the active energy ray, ultraviolet rays are generally preferably used because it is easy to handle and has a sufficient curing rate. Hereinafter, a preferred form of the ultraviolet curable adhesive will be briefly described.

(UV curable adhesive)
In one embodiment of the present invention, by applying the ultraviolet curable adhesive, it is possible to obtain high productivity and excellent durability of the laminated film.

<Composition of UV curable adhesive>
The ultraviolet curable adhesive composition includes a photoradical polymerization type composition using photoradical polymerization, a photocationic polymerization type composition using photocationic polymerization, and a hybrid type composition using both photoradical polymerization and photocationic polymerization. Things are known.

As the photoradical polymerization type composition, a radical polymerizable compound containing a polar group such as a hydroxy group or a carboxy group described in JP-A-2008-09329 and a radical polymerizable compound not containing a polar group are specified in a specific ratio. (Compositions contained in) and the like are known. In particular, the radically polymerizable compound is preferably a compound having a radically polymerizable ethylenically unsaturated bond. Preferred examples of compounds having a radically polymerizable ethylenically unsaturated bond include compounds having a (meth) acryloyl group. Examples of compounds having a (meth) acryloyl group include N-substituted (meth) acrylamide-based compounds, (meth) acrylate-based compounds, and the like. (Meta) acrylamide means acrylamide or methacrylamide.

Further, as the photocationic polymerization type composition, (α) a cationically polymerizable compound, (β) a photocationic polymerization initiator, and (γ) a wavelength longer than 380 nm as disclosed in Japanese Patent Application Laid-Open No. 2011-028234. Examples thereof include an ultraviolet curable adhesive composition containing each component of a photosensitizer exhibiting maximum absorption of light and a (δ) naphthalene-based photosensitizer. However, other ultraviolet curable adhesives may be used.

[Protective layer]
If desired, the protective layer or surface layer can be formed on the outer peripheral surface of the elastic layer. Known resins and additives are used for the protective layer. Further, it can be cured and used by using a conventionally known method.

As the resin, a thermoplastic resin layer can be used, and the thermoplastic resin is preferably a fluorine-based resin.

(Thermoplastic resin)
In the present invention, the thermoplastic resin constituting the protective layer is not particularly limited as long as it has the necessary heat resistance and releasability. For example, vinyl-based thermoplastic resins (for example, polyvinyl chloride and polyvinylidene chloride) are not particularly limited. , Polyvinyl alcohol, etc.), Polystyrene-based thermoplastic resin (for example, polystyrene, styrene / acrylonitrile copolymer, acrylonitrile / butadiene / styrene copolymer (ABS), polyethylene, ethylene / vinyl acetate copolymer, etc.), polypropylene, polyacetal , Acrylic thermoplastic resin (eg, polymethylmethacrylate, methacryl-styrene copolymer, etc.), polycarbonate, polyamide-based thermoplastic resin, polyurethane-based thermoplastic resin, fluorine-based thermoplastic resin (eg, trifluorochloroethylene (PCTFE)) ), Tetrafluoroethylene (PTFE), Tetrafluoroethylene-Hexafluoropropylene copolymer (FEP), Tetrafluoroethylene-ethylene copolymer (ETFE), Perfluoroalkoxyfluororesin (PFA), Perfluoropolyether compound ( PFPE) etc.) can be mentioned.

As for the heat resistance required for the thermoplastic resin, from the viewpoint of fixing the toner at a low temperature, a fluorine-based resin is particularly preferable from the viewpoint that high releasability is required at about 150 ° C. or higher continuously.

(Fluorine resin)
In the thermoplastic resin layer according to the present invention, the thermoplastic resin is preferably a fluororesin, and examples of the fluororesin include perfluoroalkoxy alkane-based resin (PFA) and tetrafluoroethylene-hexa as described above. Fluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), perfluoropolyether compound (PFPE) and the like can be mentioned. More preferably, it is a perfluoroalkoxy fluorinated resin (PFA) which is a copolymer of ethylene tetrafluoride and perfluoroalkoxyethylene. Specifically, it is a film-shaped or tube-shaped perfluoroalkoxy alkane-based resin (PFA), and for example, a soft PFA manufactured by Mitsui-DuPont Fluorochemical Co., Ltd., which is formed into a tube shape can be applied.

[Manufacturing method of laminated film]
FIG. 3 shows an embodiment of an apparatus for producing an endless belt for an image forming apparatus in which the laminated film of the present invention is preferably used.

As shown in FIG. 3, the coating device 101b includes a coating means 102b having a nozzle and a metal cylinder 105b. The coating means 102b discharges the coating liquid 103b with respect to the metal cylinder 105b from the nozzle to form the coating film 104b on the metal cylinder 105b. The metal cylinder 105b is rotated at a desired speed in the direction of arrow 107b, and the coating means 102b is further moved in the direction of arrow 106b to form a uniform coating film while spreading the coating liquid from the nozzle.

Hereinafter, as a preferred embodiment, a method for producing the base material layer will be described.

According to a preferred embodiment, the substrate layer can be produced using a coating liquid containing a polyimide precursor.

While slowly rotating a cylindrical mold, for example, a cylindrical metal mold (mold drum: metal cylinder 105b), the coating liquid is supplied by a liquid supply device (not shown) such as a nozzle or a dispenser. A coating film is formed by applying and casting the metal cylinder 105b so that the thickness after the heat treatment (firing) treatment becomes a predetermined thickness evenly over the entire outer surface of the metal cylinder 105b.

The number of rotations at this time is not particularly limited and can be appropriately set according to the size of the metal cylinder 105b and the like, but about 30 to 80 rpm is preferable. The solvent in the coating film is evaporated at a temperature of about 50 to 150 ° C. for about 30 to 90 minutes while gradually raising the temperature while rotating, and the residual solvent amount of the coating film is preferably 20 to 35% by mass by drying. Adjust within the range of. In this process, it is preferable to efficiently circulate and remove atmospheric vapors (volatilized solvent, etc.). The drying temperature may be set, for example, between 50 ° C. for 30 minutes and 100 ° C. for 60 minutes.

<Measurement method of residual solvent amount>
In the present invention, the amount of residual solvent can be expressed by the following formula.

Residual solvent amount (mass%) = {(MN) / N} x 100
Here, M is the mass of the base material layer at a predetermined time point (total mass of resin + solvent), and N is the mass of M when it is dried at 200 ° C. for 3 hours (mass of resin after solvent evaporation). Is. In particular, M when calculating the amount of residual solvent achieved in the solvent evaporation step is the mass of the coating film immediately after forming the base material layer and immediately before the drying step.

Next, when a self-supporting film is formed, the entire metal cylinder is transferred to a heating furnace (firing furnace) capable of high-temperature treatment, the temperature is gradually raised, and finally at a high temperature of about 250 to 450 ° C. , Heat treatment (calcination) for 10 to 90 minutes to sufficiently imidize the polyimide precursor to prepare a base material layer. After the base material layer is prepared by imidization, it is sufficiently cooled.

A primer layer and an elastic layer can be laminated on the base material layer thus produced.

Hereinafter, the formation of the elastic layer will be described. Although the elastic layer can be formed on the base material layer by injection molding, extrusion molding, etc., here, a thermosetting liquid elastomer material is used and the base material is used. A method of coating and forming on the layer and the primer layer will be described.

For example, a nozzle or dispenser is applied to a coating liquid containing a liquid thermosetting elastomer material while slowly rotating a cylindrical metal mold (mold drum: metal cylinder 105b) in the same manner as in the case of a base material layer. A liquid supply device (not shown) such as the above is used to apply and cast (form a coating film) on a base material layer formed on the outer surface of a metal cylinder 105b.

The number of rotations at this time is not particularly limited and can be appropriately set according to the size of the metal cylinder 105b and the like, but about 30 to 80 rpm is preferable. The thickness of the coating film can be controlled by controlling the supply amount of the coating liquid.

Then, while rotating the metal cylinder 105b, heat treatment is performed at a predetermined temperature and a predetermined time to cure the elastomer material and form an elastic layer. As the elastomer material, acrylonitrile rubber, chloroprene rubber or silicone rubber is preferable, and a coating liquid containing these is preferable.

The specific temperature conditions are not particularly limited and can be appropriately selected depending on the type of coating liquid and the like, but as a guide, the temperature is about 90 to 150 ° C., and the time is about 10 to 90 minutes. When the self-supporting film is formed, the metal cylinder 105b is transferred to a heating furnace capable of high temperature treatment, the temperature is gradually raised, and finally (secondary vulcanization) is performed at about 150 to 200 ° C., 30 Heat treatment (vulcanization) for ~ 120 minutes. After the elastic layer is prepared and cooled sufficiently, a protective layer may be continuously laminated on the elastic layer, if necessary.

[Image forming device]
First, an outline of the overall configuration of a typical image forming apparatus will be described with reference to the figures.

The image forming apparatus applicable to the present invention is preferably an electrophotographic image forming apparatus that fixes the toner image of the recording medium carrying the unfixed toner image on the recording medium by heating and pressurizing.

An example of a typical image forming apparatus will be described with reference to the drawings.

FIG. 4 is a schematic view showing an example of the overall configuration of the image forming apparatus applicable to the present invention.

The image forming apparatus 15 shown in FIG. 4 is an intermediate transfer type color image forming apparatus using electrophotographic process technology, and is mainly an automatic document conveying unit 20, a scanner unit 30, an image forming unit 40, and a paper feeding unit. 50, a storage unit (not shown), an operation display unit (not shown), a control unit (not shown), and the like.

The automatic document transport unit 20 is configured to include a mounting tray on which the document D is placed, a mechanism for transporting the document D, a transport roller, and the like, and transports the document D to a predetermined transport path.

The scanner unit 30 is configured to include an optical system such as a light source and a reflecting mirror, irradiates a document D transported along a predetermined transport path or a document D placed on a platen glass with a light source, and receives reflected light. .. Further, the scanner unit 30 converts the received reflected light into an electric signal and outputs it to the control unit 100.

The image forming section 40 includes a yellow image forming section Y, a magenta image forming section M, a cyan image forming section C, a black image forming section K, an intermediate transfer belt V to which the laminated film of the present invention is applied, and a laminated film of the present invention. Is provided with a fixing device F or the like having a fixing belt T to which the above is applied.

Others include a photoconductor drum 41, a charging device 42, an exposure device 43, a developing device 44, a primary transfer roller 45, a secondary transfer roller 46, and the like, but a detailed description of the configuration thereof will be omitted.

As shown in FIG. 4, the fixing device F including the fixing member according to the present invention is mainly arranged on the lower surface side of the paper P and the heating transfer roller (conveyor roller, F1) on the upper surface side. A fixing roller (first roller, F2), a heating roller (second roller, F3) arranged above the fixing roller F2, and a fixing belt T, which is a fixing member according to the present invention, are provided. There is. The fixing device F heats and pressurizes the paper P by passing the paper P through the nip portion formed by heating and pressing the heat transfer roller F1 and the fixing roller F2, and transfers the transferred toner image to the paper. Fix to P.

The heat transfer roller F1 is formed in a cylindrical shape by rubber, and like the heat roller F3, has a high output heater inside. The heat transfer roller F1 rotates in the forward direction with respect to the transfer direction of the paper P, and heats and pressurizes the non-fixed surface of the transferred paper P.

The fixing device provided with the fixing member according to the present invention can be configured in the same manner as a known fixing device having a structure corresponding to the form of the fixing member. For example, when the fixing member is the fixing belt, it is preferable that the fixing device has a structure using the fixing member, that is, a known structure for realizing biaxial tension belt fixing, pad pressing belt fixing, IH belt fixing, and the like. ..

Regarding the details of the image forming apparatus applicable in the present invention, for example, Japanese Patent Application Laid-Open No. 2017-173445, 2017-194550, 2018-4714, 2018-5016, 2018-25691 An image provided with an intermediate transfer belt described in JP-A, 2018-25691, 2018-36449, 2018-36587, 2018-54758, 2018-66768 and the like. You can refer to the forming device and the fixing device.

[Use]
The laminated film of the present invention is suitably used as an endless belt for an image forming apparatus, as an intermediate transfer belt or a fixing belt for an image forming apparatus such as an electrophotographic or inkjet copying machine, a printer or a facsimile. In particular, it is preferably used for an intermediate transfer belt or a fixing belt of an electrophotographic image forming apparatus and an inkjet image forming apparatus.

<Toner>
The fixing member or transfer member in which the laminated film of the present invention is used can be used for fixing or transferring a toner image of an electrophotographic image forming apparatus.

The electrostatic latent image developing toner (hereinafter, simply referred to as "toner") applicable to the present invention is not particularly limited as long as it contains wax as a release agent. For example, wax (release agent). In addition, it is composed of a binder resin, a colorant, a charge control agent, an external additive and the like.

The toner applicable to the present invention may be a one-component developer which is a toner particle composed of a toner matrix particle and an external additive adhering to the surface thereof, or may be a toner particle and a supporting agent thereof. It may be a two-component developer having carrier particles to be used.

Regarding the detailed configuration of the toner applicable to the present invention and the method for producing the same, for example, JP-A-2018-155912, JP-A-2018-180279, JP-A-2018-205642, and JP-A-2019-003101. You can refer to the contents described in Japanese Patent Application Laid-Open No. 2019-015924, Japanese Patent Application Laid-Open No. 2019-015977, Japanese Patent Application Laid-Open No. 2019-035906, and the like.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, the indication of "parts" or "%" is used, but unless otherwise specified, it indicates "parts by mass" or "% by mass".

Example 1
<Material used>
(varnish)
Ecrios (transparent polyimide resin): VICT-Bnp manufactured by Mitsui Chemicals, Inc. is used. The transmittance was 70% (80 μm conversion value: 420 nm wavelength), the tensile property: 4.5 GPa, the breaking strength was 130 MPa, and the elongation was 45%. Tg is 265 ° C., solid content: 14% (solvent: N-methyl-2-pyrrolidone: NMP)
U-varnish-A (polyimide resin): manufactured by Ube Industries, Ltd. Transmittance is 0% (80 μm conversion value: 420 nm wavelength), tensile properties: elastic modulus: 4 GPa, breaking strength 230 MPa, elongation 100%, solid content: 18% (solvent: NMP), Tg is 380 ° C.

(Primer)
Primer: XP81-A6361 manufactured by Momentive Performance Materials Co., Ltd.

(silicone rubber)
Silicone rubber: KE-1356 A / B agent manufactured by Shin-Etsu Chemical Co., Ltd. Transparent silicone rubber: KE-2061 A / B agent manufactured by Shin-Etsu Chemical Co., Ltd.

<Preparation of laminated film 1>
(Formation of base material layer)
A leveling agent (KF-96 manufactured by Shin-Etsu Chemical Co., Ltd.) was added to a polyimide varnish (U-varnish-A manufactured by Ube Industries, Ltd.) having a solid content of 15% by mass containing a polyimide precursor as a main component at 100 ppm based on the total mass of the polyimide varnish. The coating liquid 1 for forming the base material layer was prepared by adding the mixture so as to be the same and mixing using a mixer.

Next, a cylindrical stainless steel mold having a circumference of 1940 mm and a width of 800 mm on which a mold release agent is formed is rotated at 100 rpm around a cylindrical shaft, and the dispenser nozzle is moved in the direction of the cylindrical shaft to a width of 560 mm after firing. A wet film was formed on the outer surface of a cylindrical stainless steel mold with the above-mentioned coating liquid 1 so that the thickness of the coating liquid 1 was 80 μm.

After that, the solvent is volatilized by heating (firing) at 100 ° C. for 1.5 hours while rotating at 100 rpm around the cylindrical shaft, and the base material layer does not flow down. A film with a solvent was prepared.

Next, after adjusting the residual solvent amount of the base material layer to 20% by mass by drying, the mold was introduced into a heating furnace, and the temperature was gradually raised and the mixture was heat-treated (baked) for 90 minutes while being held at 380 ° C. Imidization was performed. After that, it was sufficiently cooled to obtain a base material layer containing a polyimide resin having a thickness of 80 μm. As a result of measuring the film thickness using MMS manufactured by Fisher Instruments Co., Ltd., it was confirmed that the film thickness was 80 μm.

The amount of the residual solvent was calculated by the following formula.

Residual solvent amount (mass%) = {(MN) / N} x 100
Here, M is the mass of the base material layer at a predetermined time point (total mass of resin + solvent), and N is the mass of M when it is dried at 200 ° C. for 3 hours (mass of resin after solvent evaporation). Is. In particular, M when calculating the amount of residual solvent achieved in the solvent evaporation step is the mass of the coating film immediately after forming the base material layer and immediately before the drying step.

(Formation of primer layer),
Using XP81-A6361 XP81-405 manufactured by Momentive Performance Materials Co., Ltd., the primer layer is rotated at 200 rpm around the cylindrical axis, and the dispenser nozzle is moved in the cylindrical axis direction while the post-drying layer thickness. After coating to a thickness of 1 μm, the drying was air-dried in the air for 10 minutes.

(Formation of elastic layer)
Silicone rubber (model number KE-1356 A / B agent, manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a coating liquid for forming an elastic layer.

Using the polyimide base material layer formed on the outer peripheral surface of the mold, the wet film is rotated at 200 rpm around the cylindrical axis and the dispenser nozzle is moved in the direction of the cylindrical axis so that the thickness after firing becomes 250 μm. Was laminated. The solvent was volatilized by heating at 100 ° C. for 1 hour using a far-infrared drying device while rotating the cylinder shaft at 200 rpm so that the elastic layer did not flow down. Finally, the mold was introduced into a heating furnace, heated stepwise, heated at 200 ° C. for 60 minutes (vulcanization), and then sufficiently cooled.

Through the above steps, an endless belt-shaped laminated film 1 for an image forming apparatus having a thickness of 331 μm, which is obtained by sequentially stacking a base material layer, a primer layer, and an elastic layer, was produced.

<Shrinkage rate of base material layer>
The shrinkage rate of the base material layer of the laminated film 1 is 100 to 400 ° C. when the prepared base material layer is heat-treated in a nitrogen gas environment while raising the temperature at 5 ° C./min in the range of 30 to 450 ° C. When the shrinkage rate represented by the following formula (1) was determined, it was 0.5%.

Equation (1) Shrinkage rate (%) = {(YX) / A} x 100
(In the formula, the length of the base material layer at 30 ° C. is A, the shrinkage length of the base material layer at 100 ° C. is X, and the shrinkage length of the base material layer at 400 ° C. is Y.)
Here, the shrinkage ratio was measured using an EXSTAR TMA / SS6100 (manufactured by Hitachi High-Tech Science Corporation), which is a thermomechanical analyzer (TMA).

The base material with respect to the temperature represented by the above formula (1) between 100 and 400 ° C. when the base material layer is heat-treated in a nitrogen gas environment while raising the temperature at 5 ° C./min in the range of 30 to 450 ° C. Measure the maximum shrinkage rate of. The sample piece size is 4 × 15 mm (distance between chucks is 10 mm).

<Preparation of laminated films 2 to 8>
In the production of the laminated film 1, the resin (varnish), the type of elastic layer material, the amount of residual solvent, and the presence / absence of the primer layer are changed as shown in Table I, and the laminated film 2 is produced in the same manner as in the production of the laminated film 1. ~ 8 was manufactured.

≪Evaluation method≫
(1) T-type peeling test in the initial state (JIS-K6854-3)
Half of the film interface where the base material layer and the elastic layer were adhered was carefully peeled off with a cutter, and a T-type peeling test was carried out. In the T-type peeling test, the interlayer adhesiveness between the base material layer and the elastic layer was measured at a peeling rate of 100 mm / min for the adhesive strength of the laminated body by using the method specified in JIS K-6854.

4.5N or more was evaluated as 〇, 4.0 to less than 4.5N was evaluated as Δ, less than 4N was evaluated as ×, and delamination was evaluated as XX.

(2) Durability test by winding rollers (after sliding drive)
A base material / elastic layer film was attached to the Bizhub PRESS C7000 fuser with a polyimide tape, and a continuous sliding drive equivalent to 600 kp was carried out.

After the implementation, a T-type peeling test was conducted in the same manner, and evaluation was carried out from the same viewpoint as above.

The composition and evaluation results of the above laminated film are shown in Table I below.

From Table I, it was found that the laminated film of the present invention was excellent in adhesiveness between layers in each peeling test.

1 Laminated film 2 Base material layer 3 Primer layer 4 Elastic layer 10 Fixing member 15 Image forming device 20 Automatic document transfer part 30 Scanner part 40 Image forming part 41 Photoreceptor drum 42 Charging device 43 Exposure device 44 Developing device 45 Primary transfer roller 46 Secondary transfer roller 47, 48 Cleaning device 50 Paper feed section D Original F fixing device F1 Heat transfer roller (conveyor roller)
F2 fixing roller (first roller)
F3 heating roller (second roller, heating part)
P Recording medium T Fixing belt (laminated film)
V Intermediate transfer belt (laminated film)
101b Coating device 102b Coating means with nozzle 103b Coating liquid 104b Coating film 105b Metal cylinder 106b Arrow 26
107b arrow 27

Claims (7)

A laminated film having a base material layer and an elastic layer,
The following in the range of 100 to 400 ° C. when the base material layer contains a polyimide resin and the base material layer is heat-treated in a nitrogen gas environment while raising the temperature at 5 ° C./min in the range of 30 to 450 ° C. The shrinkage rate represented by the formula (1) is in the range of 0.5 to 3.0%, and
A laminated film characterized in that the base material layer and the elastic layer are adhered by a primer layer.
Equation (1) Shrinkage rate (%) = {(YX) / A} x 100
(In the formula, the length of the base material layer at 30 ° C. is A, the shrinkage length of the base material layer at 100 ° C. is X, and the shrinkage length of the base material layer at 400 ° C. is Y.) The laminated film according to claim 1, wherein the base material layer contains a polyimide resin in which a coating film containing a polyimide resin precursor is heat-imidized. The laminated film according to claim 1 or 2, wherein the elastic layer contains silicone rubber. The laminated film according to any one of claims 1 to 3, wherein the glass transition temperature (Tg) of the polyimide resin is 400 ° C. or lower. The laminated film according to any one of claims 1 to 4, wherein the laminated film is a transfer belt or a fixing belt. A method for producing a laminated film according to any one of claims 1 to 5, wherein the laminated film is produced.
In the step of forming the base material layer, a coating film is formed with a coating liquid containing at least a polyimide resin precursor, and the amount of residual solvent in the coating film is adjusted within the range of 20 to 35% by mass by drying. A method for producing a laminated film, which comprises a step of heating imidizing the polyimide resin precursor to form a polyimide resin. 6. The sixth aspect of the present invention includes a step of forming the elastic layer on the base material layer while supplying the coating liquid for forming the elastic layer to the inner surface or the outer surface of the cylindrical mold by the liquid supply device. The method for producing a laminated film according to the above.

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