TWI811636B - Inorganic substrate/engineering plastic film laminate with protective film, stacking of laminates, storage method of laminates, and transportation method of laminates - Google Patents

Abstract

The object of the present invention is to use a protective film to protect an engineering plastic/inorganic substrate laminate used in a manufacturing method of a flexible electronic device. The solution of the present invention is in an inorganic substrate/engineering plastic film laminate that sequentially includes an inorganic substrate, an engineering plastic film, an adhesive layer of a protective film, and an inorganic substrate/engineering plastic film laminate with a protective film base material. The bonding strength Fb of the engineering plastic film by the 90-degree peeling method, and the bonding strength Fp of the engineering plastic film and the protective film by the 90-degree peeling method are combined in a relationship such that Fp<Fb, and the protective film base material is The surface roughness Ra of the surface opposite to the adhesive material layer is in the range of 0.02 μm to 1.2 μm, thereby obtaining an inorganic substrate/engineering plastic film laminate with a protective film that has good storage properties, operability, and transportation properties.

Description

Inorganic substrate/engineering plastic film laminate with protective film, stacking of the laminate, storage method of the laminate, and transportation method of the laminate

The present invention relates to the form and storage method for storing a laminate of an inorganic substrate and an engineering plastic film (hereinafter referred to as the engineering plastic film), and further relates to a transportation method thereof.

As substrate materials for manufacturing flexible electronic devices, the use of polyamide, aromatic polyamide, polyamide, polycarbonate, polyethylene naphthalate, polyterephthalate has been studied. Engineering plastic films such as ethylene formate. This kind of engineering plastic film is manufactured in a long roll shape, so it is generally considered ideal to use a roll-to-roll production line in the manufacture of flexible devices. On the other hand, conventional electronic devices such as display devices, sensor arrays, touch screens, and printed wiring boards mostly use hard rigid substrates such as glass substrates, semiconductor wafers, or glass fiber reinforced epoxy substrates. Regarding manufacturing equipment, It is also constructed based on the use of this rigid substrate.

Against this background, as a method of manufacturing a flexible electronic device using existing manufacturing equipment, a method of manufacturing a flexible electronic device using the following procedure is known: using a rigid inorganic substrate such as a glass substrate as a temporary support, and The engineering plastic film is operated in a state where it is temporarily attached to a temporary support. After the electronic device is processed on the engineering plastic film, the engineering plastic film on which the electronic device is formed is peeled off from the temporary support (Patent Document 1).

In addition, as a method of manufacturing a flexible electronic device using existing manufacturing equipment, the following method is known: using a rigid substrate such as a glass substrate as a temporary support, applying an engineering plastic precursor in a solution state to the temporary support, and then applying the precursor to the temporary support. After drying to form a precursor film, a chemical reaction is initiated to convert the precursor into engineering plastic, thereby obtaining a laminate of the temporary support and the engineering plastic film. In the same manner, an electronic device is formed on the engineering plastic film and then peeled off. A flexible electronic device is manufactured (Patent Document 2).

That is, in either method, a laminated body in the form of a rigid temporary support and an engineering plastic film layer is superimposed, and the engineering plastic film will eventually be peeled off to become the base material of the flexible electronic device. Since the laminated body can be handled as a rigid plate material, it can be handled in the same manner as a glass substrate by a device used to manufacture liquid crystal displays, plasma displays, organic EL displays, etc., which have conventionally used glass substrates.

[Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 5152104 [Patent Document 2] Japanese Patent No. 5699606

[Problem to be solved by the invention]

The subject of the present invention is the form, storage method, and even transportation method when storing the above-mentioned laminate including an engineering plastic film and a rigid temporary support. Conventionally, rigid inorganic substrates such as glass substrates are handled in a stacked form in which multiple sheets are stacked during storage or transportation. When stacking, a buffer material such as a foamed polymer sheet or paper is sandwiched between the inorganic substrates so that the inorganic substrates can be easily taken out of the stack after storage or transportation. This method can be applied to glass substrates with sufficient surface hardness. However, in the laminate of the temporary support substrate and the engineering plastic film processed by the present invention, the surface hardness of the engineering plastic film is insufficient. Therefore, if the laminates are stacked, the engineering plastic film surface of the laminate will rub against the temporary support substrate surface, which may cause Causes scars on the surface of soft engineering plastic film. Furthermore, when cushioning materials such as foamed polymer sheets or paper are put in, scratches can easily occur on the surface of the engineering plastic film due to mixed foreign matter.

A commonly used method to solve this problem is to protect the engineering plastic film surface with a protective film. Generally speaking, protective films are micro-adhesive films made by coating one side of relatively cheap polymer films such as polyethylene, polypropylene, and polyester with a weakly adhesive adhesive material.

By using this protective film, the surface of the engineering plastic film can be prevented from being damaged and the surface of the engineering plastic film suitable for forming fine flexible electronic devices can be maintained. However, the inventors of the present case faced the following problem: when a plurality of laminates with a protective film attached to the engineering plastic film surface of the laminate are stacked together for storage or transportation, the protective film surface and the temporary The support substrate surface becomes attached and becomes difficult to remove individually. Although it is possible to use a cushioning material such as a foamed polymer sheet or paper in combination with the glass substrate, it requires the use of auxiliary materials in addition to the protective film, which increases the cost and leads to an increase in waste. Therefore, the use of cushioning materials cannot be said is the better method.

The problem to be solved by the present invention is to provide an appropriate form and method for storing or transporting a laminated body including an engineering plastic film and a rigid temporary support. That is, the present invention provides an inorganic substrate/engineering plastic film laminate with a protective film that can be easily taken out individually even if it is stored in a stacked state for a long time, and provides an inorganic substrate/engineering process with a protective film. The invention provides a stack of plastic film laminates, a storage method of an inorganic substrate/engineering plastic film laminate using a specific protective film, and a transportation method of the inorganic substrate/engineering plastic film laminate. [Means used to solve problems]

That is, the present invention includes the following configurations. [1] An inorganic substrate/engineering plastic film laminate with a protective film, which is characterized by: sequentially including an inorganic substrate, an engineering plastic film, an adhesive material layer of the protective film, and a protective film base material of the protective film. In the inorganic substrate/engineering plastic film laminate, the bonding strength Fb of the inorganic substrate and the engineering plastic film using the 90-degree peeling method, and the bonding strength Fp of the engineering plastic film and the protective film using the 90-degree peeling method are such that Fp < Fb relationship, and the surface roughness Ra of the surface of the protective film base material opposite to the adhesive layer is in the range of 0.02 μm to 1.2 μm. [2] The inorganic substrate/engineering plastic film laminate with a protective film as described in [1], which is characterized by: the surface of the protective film base material opposite to the adhesive material layer, and the surface of the above-mentioned inorganic substrate not related to the engineering The kinetic friction coefficient between the opposite sides of the plastic film is in the range of 0.02 to 0.25. [3] The inorganic substrate/engineering plastic film laminate with a protective film as described in [1] or [2], characterized in that the surface roughness Ra of the surface of the inorganic substrate not facing the engineering plastic film is 0.01 ~2nm range. [4] The inorganic substrate/engineering plastic film laminate with a protective film according to any one of [1] to [3], characterized in that the bonding strength Fb of the inorganic substrate and the engineering plastic film is 0.02 to 0.3N/cm range. [5] The inorganic substrate with protective film/engineering plastic film laminate according to any one of [1] to [4], characterized in that the bonding strength Fp of the engineering plastic film and the protective film is 0.01 to 0.27 N/cm range. [6] The inorganic substrate/engineering plastic film laminate with a protective film according to any one of [1] to [5], characterized in that the diameter of the circumscribed circle of the inorganic substrate is 310 mm or more. [7] The inorganic substrate/engineering plastic film laminate with a protective film as described in any one of [1] to [6], characterized by being left in an environment of 23°C and 50% RH for more than 24 hours. In this case, the surface resistance of the surface of the protective film base material opposite to the adhesive material is in the range of 1×10 ⁶ to 1×10 ¹⁰ [Ω]. [8] A stack of an inorganic substrate with a protective film/engineering plastic film laminate, characterized by: the inorganic substrate with a protective film/engineering plastic film as described in any one of the above [1] to [7] Four or more laminated bodies are stacked in the same direction in the layer direction. [9] A method for storing an inorganic substrate/engineering plastic film laminate with a protective film, which is characterized by packaging the inorganic substrate/engineering plastic film laminate with a protective film in a stacked form as described in [8] and keep it. [10] A method of transporting an inorganic substrate/engineering plastic film laminate with a protective film, which is characterized by packaging the inorganic substrate/engineering plastic film laminate with a protective film in a stacked form as described in [8] and transport. [Effects of the invention]

In the case of general protective films, when stored in a stacked state for a long time, the air layer between the surface of the protective film and the opposite surface of the inorganic substrate will gradually be discharged from between the two surfaces due to the weight of the laminate, resulting in Vacuum sealing state. This is the reason why it becomes difficult to individually take out the laminated bodies during long-term storage. When the size of the laminated body is small, this does not become a big problem. However, assuming that the display manufacturing apparatus is operated, the size of the laminated body is a glass plate of about 2 m×3 m at most. When a multi-sheet laminated body of this size is brought into a vacuum-adhered state, it is very difficult to peel off, and when the temporary support substrate is a glass plate, breakage of the glass substrate or the like becomes easy to occur. By using the specific protective film of the present invention, such problems can be avoided. The inorganic substrate/engineering plastic film laminate with protective film of the present invention can be easily stored for a long time even if it is overlapped and made into a stack. Take out individually.

[Form used to implement the invention]

As the inorganic substrate in the present invention, a glass plate, a semiconductor wafer, a metal plate, a ceramic plate, etc. can be used. Examples of the glass plate include quartz glass, high silicate glass (96% silica), soda-lime glass, lead glass, aluminoborosilicate glass, and borosilicate glass (Pyrex (registered trademark)). , borosilicate glass (alkali-free), borosilicate glass (microsheet), aluminosilicate glass, etc. Among these, the linear expansion coefficient is preferably 5 ppm/K or less. If it is a commercial product, it is preferably "Corning (registered trademark) 7059" or "Corning (registered trademark) 1737" made by Corning Co., Ltd. for liquid crystal glass. , "EAGLE", "AN100" made by Asahi Glass Co., Ltd., "OA10" made by Nippon Electric Glass Co., Ltd., "AF32" made by SCHOTT Co., Ltd., etc. Examples of the semiconductor wafer include: silicon wafer, germanium, silicon-germanium, gallium-arsenic, aluminum-gallium-indium, nitrogen-phosphorus-arsenic-antimony, SiC, InP (indium phosphide), InGaAs, GaInNAs, LT, LN, ZnO (zinc oxide) or CdTe (cadmium telluride), ZnSe (zinc selenide) and other wafers. The aforementioned metal plate includes single-element metals such as W, Mo, Pt, Fe, Ni, and Au, or Inconel, Monel, Nimonic, and carbon copper. , Fe-Ni invar alloy, super invar alloy, various stainless steel and other alloys. In addition, these metals also include multi-layer metal plates with additional metal layers and ceramic layers. As the ceramic plate, single or composite sintered bodies of aluminum oxide, magnesium oxide, calcium oxide (calcia), silicon nitride, boron nitride, aluminum nitride, beryllium oxide, etc. can be used. In the present invention, when using a ceramic substrate, it is preferable to use a ceramic substrate whose surface is smoothed by glass glaze treatment.

The surface roughness of the inorganic substrate in the present invention is preferably in the range of 0.01 to 2 nm. When the inorganic substrate is laminated with engineering plastic, the surface roughness of at least the surface opposite to the engineering plastic film is preferably in the range of 0.01 to 2 nm. Furthermore, the preferred range of surface roughness is the range of 0.01 to 0.8 nm, and the further preferred range is the range of 0.01 to 0.3 nm. By controlling the surface roughness of the inorganic substrate within this range, the bonding strength with the engineering plastic film becomes easy to control, and the dynamic friction coefficient with the protective film base material explained separately can be converged to a predetermined range.

In the present invention, the size of the inorganic substrate is preferably such that the diameter of the circumscribed circle is 310 mm or more when the inorganic substrate is rectangular. By using an inorganic substrate of this size, it is possible to fully obtain the effects of the present invention that improve storage, transportation, and other operability of stacked laminates.

The engineering plastic film in the present invention refers to a film of a polymer compound that maintains a tensile strength of more than 49 MPa and a bending elastic coefficient of more than 2.5 GPa even if it is exposed to an environment above 100°C for a long time, preferably 168 hours. It is preferably a polymer film that can be used for a long time at 150°C, preferably at least 168 hours, and has a glass transition temperature of 115°C or higher, preferably 130°C or higher, and further preferably 145°C or higher. Polymer film. More specifically, it is amorphous polyarylate (polyarylate), polystyrene, polyether sulfide, polyphenylene sulfide, polyether ether ketone, polyamide imide, polyamide amide imine, polyether amide imine, Films of polybenzoethazole, polyethylene naphthalate, polysiloxy resin, fluororesin, liquid crystal polymer, etc. In the present invention, it is particularly preferable to use a polymer film having an imine bond. Examples of the polymer film having an imine bond include polyimide, polyimide imine, polyether imine, polyimide benzoxazole, and bismaleimide triazine) etc.

In the present invention, as the polyamideimide film, aromatic polyamideimide, alicyclic polyamideimide, polyamideimide, polyetherimide, etc. can be used. More preferably, it refers to a polymer containing more than 50% polyimide skeleton. Generally speaking, a polyamide film can be obtained by coating a polyamide acid (polyamide precursor) solution obtained by reacting diamines and tetracarboxylic acids in a solvent on a polyamide film. A support for producing a polyimide film is dried and becomes a green film (also known as a "precursor film" or "polyamide film"), which is further used as a support for producing a polyimide film. On the green film, or in a state of being peeled off from the support, the green film is subjected to high-temperature heat treatment to cause dehydration and ring-closure reaction.

The diamines constituting the polyamide are not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines, etc. that are generally used in the synthesis of polyimides can be used. From the viewpoint of heat resistance, aromatic diamines are preferred, and among aromatic diamines, aromatic diamines having a benzoethazole structure are more preferred. When aromatic diamines having a benzoethazole structure are used, it becomes possible to exhibit high flexural elastic modulus, low thermal shrinkage, and low linear expansion coefficient together with high heat resistance. The diamines may be used alone, or two or more types may be used in combination.

Polyimide resins are generally colored yellow or brown, but depending on the chemical structure, colorless and highly transparent polyimide films can be obtained. Examples of the acid component used in the synthesis of the precursor include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclopentanetetracarboxylic dianhydride, 1 ,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo[2,2,1]heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2,2,2]octane Alkane-2,3,5,6-tetracarboxylic dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic dianhydride, 1,2,4-cyclohexanetricarboxylic anhydride, etc., especially good It is 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic acid dianhydride. These aliphatic carboxylic acids may be used alone, or two or more types may be used in combination. On the other hand, those containing an unsaturated bond such as bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride may be used in combination.

If the diamine component used in the synthesis of the colorless and transparent polyimide-based resin of the present invention or its precursor is exemplified as a diamine compound, 1,3-phenylenediamine and 1,4-phenylenediamine can be exemplified. Amine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,4-diaminotoluene, 4,5-dimethyl-1,2-phenylenediamine, 2,5-diamine Methyl-1,4-phenylenediamine, 2,6-dimethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 3-amine m-xylylenediamine, o-xylylenediamine, 1,5-diaminonaphthalene, 2,2'-dimethylbiphenyl-4,4'-diamine, 2,2'-bis(trifluoromethyl)benzidine, 3,3'-dimethoxybenzidine, 4,4'-diaminooctafluorobiphenyl, 3,3'-diaminodiphenyl methylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-methylenebis(2,6-diethylaniline), 4 ,4'-methylenebis(2-ethyl-6-methylaniline), 4,4'-ethylidene diphenylamine, 4,4'-diaminodiphenyl ether, 3,4'-bis Aminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, 1,3-bis(4 -Aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,4-bis(4-amine 2-trifluoromethylphenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl Phenylmethane, bis[4-(4-aminophenoxy)phenyl]terine, bis[4-(3-aminophenoxy)phenyl]terine, 2,2-bis(4-amino) Phenyl)hexafluoropropane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2 '-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, α,α'-bis (4-Aminophenyl)-1,4-diisopropylbenzene, bis(2-aminophenyl)sulfide, bis(4-aminophenyl)sulfide, 3,3'-diamine Diphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminobenzophenone, 3,3'- Diaminobenzophenone, 4,4'-diaminobenzanilide, 1,4-bis(4-aminophenoxy)benzene, bis(4-amine terephthalate) Aromatic diamines such as phenyl) ester, 2,7-diaminophenyl, and 9,9-bis(4-aminophenyl)fluorine. Moreover, examples of aliphatic diamines include: 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1, 1-bis(4-aminophenyl)cyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4 '-Methylenebis(2,6-dimethylcyclohexylamine), 4,4'-diaminodicyclohexylpropane, bicyclo[2.2.1]heptane-2,3-diamine, bicyclo[ 2.2.1]heptane-2,5-diamine, bicyclo[2.2.1]heptane-2,6-diamine, bicyclo[2.2.1]heptane-2,7-diamine, 2,3- Bis(aminomethyl)-bicyclo[2.2.1]heptane, 2,5-bis(aminomethyl)-bicyclo[2.2.1]heptane, 2,6-bis(aminomethyl)- Bicyclo[2.2.1]heptane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0(2,6)]decane, etc. Among these, p-phenylenediamine, 2,2'-dimethylbiphenyl-4,4'-diamine, 2,2'-bis(trifluoromethyl)benzidine, 2,2 '-Bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 1,4-bis Aminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(2, 6-Dimethylcyclohexylamine). The above-mentioned amine components may be used alone, or two or more types may be used in combination.

In the present invention, an inorganic substrate and an engineering plastic film are laminated. In this case, the bonding strength between the inorganic substrate and the engineering plastic film laminate is preferably in the range of 0.02 to 1.0 N/cm, and more preferably in the range of 0.03 to 0.3 N/cm. This bonding strength is based on the assumption that the inorganic substrate and the engineering plastic film will be peeled off in the future.

The laminated body of the present invention can be divided into the following three categories according to the production method. (1) Method of pre-making an engineering plastic film and bonding it to the inorganic substrate. (2) A method of coating a solution of engineering plastics or a solution of engineering plastic precursors on an inorganic substrate and performing drying and chemical reactions as required to form a thin film of engineering plastics on the inorganic substrate. (3) A method of preparing a thin film of an engineering plastic film precursor in advance, and then performing a chemical reaction after bonding it to an inorganic substrate to form a thin film of engineering plastic on the inorganic substrate.

Among the methods of (1) making an engineering plastic film in advance and attaching it to an inorganic substrate, there are cases in which an adhesive is used and a method in which the following method is used: surface treatment is performed on both or one of the surfaces of the engineering plastic film and the inorganic substrate. Activated and directly attached method. Specific examples of the latter include: a method of treating the surface of an engineering plastic film with active energy rays, plasma, etc.; a method of treating the surface of an inorganic substrate in the same way; a method of further chemical modification using a coupling agent, etc. In addition, in order to control the peeling strength of the engineering plastic film and the inorganic substrate, technologies such as mold release agent treatment and mold release layer formation can also be combined.

It is better to use the above method (2) to apply the solution of engineering plastic or the solution of engineering plastic precursor on the inorganic substrate and perform drying and chemical reaction according to the requirements to form a thin film of engineering plastic on the inorganic substrate. A solution of polyimide-based resin or a precursor of polyimide-based resin is used. As a precursor of polyimide-based resin, a solution in the state of isoimide or polyamide acid is applied to an inorganic substrate, and then heated or catalyzed after drying to obtain polyimide. amine film. Drying and heating can also be performed simultaneously and in parallel.

In the case of using the aforementioned (3) method of pre-preparing a thin film of engineering plastic film precursor, laminating it to an inorganic substrate and then performing a chemical reaction, and forming a thin film of engineering plastic on the inorganic substrate, first coating it on a polyester film, etc. An engineering plastic precursor, preferably a polyimide precursor, is dried and chemically changed according to requirements to obtain a gelatinous film. Solvents may also remain in the gelatinous film. The gel-like film thus obtained has a certain degree of viscosity, so it can be laminated by pressing it against the inorganic substrate. The gelatinous film can also be interpreted as the B stage of hardened resin. That is, this method can thin curable resins such as epoxy resin, melamine resin, phenol resin, and BT resin on an inorganic substrate to form an engineering plastic film. In the present invention, thin films of these curable resins can also be used as Engineering plastic film for processing.

In the present invention, the bonding strength Fb between the inorganic substrate and the engineering plastic film is preferably in the range of 0.02 to 0.3 N/cm. The adhesion strength does not necessarily need to be within this range, but in the present invention, it is particularly effective in laminates that require weak adhesion, that is, peeling off the engineering plastic film from the inorganic substrate in a subsequent step.

In the present invention, the engineering plastic film surface of the laminate of the engineering plastic film and the inorganic substrate is covered with a protective film. The protective film system in the present invention is composed of at least a protective film base material and an adhesive material layer. As the protective film base material, in addition to PET film, PEN film, polyethylene film, polypropylene film, nylon film, etc., PPS film, PEEK film, aromatic polyamide film, polyimide film, polyimide film, etc. can also be used. Heat-resistant super engineering plastic films such as polyimidebenzazole films.

The adhesive material of the protective film is not particularly limited, and known ones such as acrylic type, polysilicone type, urethane type, rubber type, polyester type, etc. can be used. From the viewpoint of handleability, acrylic resins, silicone resins, and urethane resins are preferred. The acrylic resin is obtained by polymerizing monomers such as alkyl (meth)acrylate. Specific examples of the monomer include: (meth)acrylic acid methyl ester, (meth) ethyl acrylate, (meth) acrylic acid propyl ester, (meth) acrylic acid n-butyl ester, (meth) acrylic acid isopropyl isoester Butyl ester, tertiary butyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate , (meth)acrylic acid alkyl ester compounds such as lauryl (meth)acrylate and stearyl (meth)acrylate. These can also be copolymerized according to needs.

The surface roughness Ra of the protective film base material in the present invention is preferably 0.02 μm or more, preferably 0.025 μm or more, and further preferably 0.03 μm or more on the surface opposite to the adhesive layer, and the upper limit is A range of 1.2 μm or less, preferably 0.6 μm or less, further preferably 0.3 μm or less is still more preferred. An example of a method for controlling the surface roughness of the protective film base material within a predetermined range is a method of adding inorganic particles to the raw resin to control the surface roughness when producing a thin film of the protective film base material. As the inorganic particles, a predetermined amount of known inorganic particles such as silicon oxide, aluminum oxide, calcium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, calcium phosphate, magnesium phosphate, barium sulfate, talc, kaolin, etc. may be added. The amount added varies depending on the stretching ratio when making the base film, the final base film thickness, the particle size distribution of the added inorganic particles, etc., but generally it is 500 ppm or more in terms of mass ratio relative to the mass of the base film resin. , preferably 1000 ppm or more, further preferably 2000 ppm or more, and the upper limit is 10 mass % or less, preferably 3 mass % or less, further preferably 10000 ppm or less. As a method of controlling the surface roughness of the protective film base material within a predetermined range, a method of grinding or grinding the surface of the film base material to obtain a predetermined surface roughness can be exemplified. Furthermore, an example of a method for controlling the surface roughness of the protective film base material within a predetermined range is to cast the film raw material onto a support base material that has been produced in advance to have a predetermined surface roughness to obtain the protective film base material. Methods. In addition, a method of controlling the surface roughness of the protective film base material by pressing an embossing roller or the like processed into a predetermined surface shape may also be exemplified.

In the present invention, the bonding strength Fp of the engineering plastic film and the protective film using the 90-degree peeling method is preferably in the range of 0.01 to 0.27 N/cm. Furthermore, in the present invention, the bonding strength Fb between the inorganic substrate and the engineering plastic film by the 90-degree peeling method, and the bonding strength Fp between the engineering plastic film and the protective film preferably have a relationship of Fp<Fb. That is, it is preferable to set the adhesive force between each layer so that the engineering plastic film will not peel off from the inorganic substrate when the protective film is peeled off from the engineering plastic film. The type of adhesive material is dependent on the peeling speed, so the adhesion force between the respective layers varies depending on the peeling speed. In particular, if the peeling speed is increased, the peeling strength tends to increase. However, from the viewpoint of shortening the process time, the peeling speed during peeling is preferably faster, but is preferably at least 50 mm/min, and desirably 100 mm/min or less. In addition, the above-mentioned bonding strengths Fp and Fb are based on the 90-degree peeling method. However, the peeling strength between the engineering plastic film and the protective film, and the peeling strength between the inorganic substrate and the engineering plastic film are preferably 180-degree peeling. The relationship is Fp<Fb.

In the present invention, the dynamic friction coefficient between the surface of the protective film base material opposite to the adhesive material layer and the surface of the inorganic substrate not opposite to the engineering plastic film is in the range of 0.02 to 0.25. The dynamic friction coefficient can be achieved by controlling the surface roughness of the surface of the protective film substrate opposite to the adhesive layer and the surface of the inorganic substrate not facing the engineering plastic film within the aforementioned range.

In the present invention, a plurality of the above-described laminates can be stacked to form a stack, preferably 4 or more sheets, more preferably 10 or more sheets. In the present invention, when a stack is formed, the kinetic friction coefficient between the surface of the adjacent protective film base material opposite to the adhesive material and the inorganic substrate is within a predetermined range, so that the laminated bodies can be easily taken out individually from the stack.

In the present invention, the surface resistance of the surface of the protective film base material opposite to the adhesive material is preferably 1×10 ⁶ to 1×10 ¹⁰ [ Ω] range. That is, it is preferable that the surface of the protective film has electrical conductivity to such an extent that it is ineffective and does not become electrified. If the protective film surface is charged, when the laminates are stacked to form a stack, the protective film surface and the inorganic substrate surface may come into close contact due to static electricity, making it difficult to individually take out the laminates.

In the present invention, the laminated body can be stored in the stacked state thus obtained. The stacking of the present invention can be stored in any of the following situations: when the stacked inorganic substrates are stored in a horizontal direction, when they are stored in a vertical direction, or when they are nearly vertical and tilted at 75 to 89 degrees. The situation of storage is left and right.

In the present invention, the laminated body can be transported in the stacked state thus obtained. The stacking of the present invention can correspond to any of the following situations: a situation in which the stacked inorganic substrates are held in a horizontal direction for transportation; a case in which the stacked inorganic substrates are held in a vertical direction for transportation; or a situation in which the stacked inorganic substrates are held in a vertical direction and tilted by 75 to 75 degrees. The condition is maintained at around 89 degrees for transportation. [Example]

The following examples are given to illustrate the present invention more specifically, but the present invention is not limited to the following examples. The physical property evaluation methods in the following examples are as follows. ＜Surface roughness＞ Surface roughness Ra, Rt and Rsm are measured using a stylus type surface roughness meter in accordance with JIS B 0601. ＜Dynamic friction coefficient＞ Regarding the dynamic friction coefficient, the friction coefficient fixture was installed on the tensile testing machine and measured in accordance with JIS K 7125. Tensile testing machine: "Autograph (registered trademark) AG-IS" manufactured by Shimadzu Corporation

＜Adhesion strength＞ The bonding strength between the engineering plastic film and the inorganic substrate and the bonding strength between the protective film and the engineering plastic film (before heating) were measured under the following conditions in accordance with the 90-degree peeling method described in JIS K 6854-1. Moreover, the adhesive strength after heating at 120 degreeC for 1 hour was measured similarly. Tensile testing machine: "Autograph (registered trademark) AG-IS" manufactured by Shimadzu Corporation Measuring temperature: room temperature Peeling speed: 50mm/min Gas environment: atmosphere Measurement sample width: 10mm ＜Surface resistance＞ A resistance measurement unit 16008B made by Agilent Technologies was installed on the milliohmmeter 4338B made by Agilent Technologies to perform measurements according to the method of IEC 62631-3-2.

＜Manufacturing of engineering plastic film/inorganic substrate laminate L1＞ As the engineering plastic film F1, polyimide film Upilex 25S manufactured by Ube Kosan Co., Ltd. was used. First, one side of the engineering plastic film is treated with atmospheric pressure plasma using nitrogen. As the inorganic substrate, a glass plate OA10G made of Nippon Electric Glass with a thickness of 370 mm×470 mm and a thickness of 0.7 mm was used. First, after cleaning the surface of the glass plate with UV/ozone treatment, put the glass plate and the heating plate into a clean chamber (clean chamber). After supporting the glass plate on the support stage, replace the chamber with clean dry nitrogen. , place a Petri dish filled with silane coupling agent (3-aminopropyltrimethoxysilane) with the liquid level 200mm below the inorganic substrate, and heat the Petri dish to 100°C with a heating plate to make the lower surface of the inorganic substrate After being exposed to the silane coupling agent vapor for 3 minutes, take it out of the chamber and place it on a clean bench. Place the inorganic substrate in a temperature-adjusted temperature of 120°C so that the side opposite to the exposed surface is in contact with the hot plate. Heat treatment was performed on a hot plate at 100°C for 1 minute to obtain a glass plate treated with a silane coupling agent. Then, the atmospheric pressure plasma treated surface of the previously obtained engineering plastic film is overlapped with the silane coupling agent treated surface of the glass plate, so that the two are closely bonded using a roller laminator, and heat treated at 150°C for 30 seconds in a clean oven. Minutes, a laminate L1 of engineering plastic film/inorganic substrate is obtained.

＜Manufacturing of engineering plastic film/inorganic substrate laminates L2 to L4＞ Next, except that the engineering plastic film is changed to the following, the same operation is performed to obtain the engineering plastic film/inorganic substrate laminates L2 to L4: F2: Polyimide film Kapton 100H manufactured by DuPont-Toray; F3: Polyimide film Xenomax 38LR manufactured by Toyobo Co., Ltd.; F4: Liquid crystal polymer film Vecstar CTQ-25 manufactured by Kuraray Corporation.

＜Manufacturing of engineering plastic film/inorganic substrate laminate L5＞ Polyimide ("Neopulim" manufactured by Mitsubishi Gas Chemical Co., Ltd., glass transition temperature: 390°C) was prepared. This polyimide was dissolved in a 9:1 mixed solvent of N,N-dimethylacetamide and γ-butyrolactone to prepare a varnish (concentration: 20% by mass). This varnish was formed on a polyethylene terephthalate (PET) film with a thickness of 188 μm and a width of 750 mm by a casting method. At a line speed of 0.2m/min, the film-formed varnish is passed through a 12m-long furnace whose temperature is set from 50°C to 75°C in stages, thereby removing the solvent from the varnish to form a transparent resin film/PET film The two-layer body is rolled into a roll shape. Then, the two-layer body is rolled out from this roll and the transparent resin film and PET film are peeled off. The transparent resin film is cut into a predetermined size and heated in an inert oven at 210°C for 60 minutes in a nitrogen atmosphere. Dry to obtain a colorless and transparent polyimide film. This film is regarded as engineering plastic film F5. Using the obtained engineering plastic film F5, the same operation as the production of the engineering plastic film/inorganic substrate laminated body L1 was performed to obtain the engineering plastic film/inorganic substrate laminated body L5.

＜Manufacturing of engineering plastic film/inorganic substrate laminate L6＞ Prepare a reactor and oil bath consisting of a detachable flask equipped with a silicone tube, a stirring device, and a thermometer. 519.84 parts by mass of dimethylacetamide, 75.52 parts by mass of 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA) and 54.44 parts by mass of 2,2 were put into this flask. '-bis(trifluoromethyl)-4,4'-diaminodiphenyl (TFMB), and stir until the contents of the flask become a uniform solution. Next, stirring was continued for 20 hours while adjusting the temperature in the container so that it would fall within the range of 25°C±5°C using an oil bath, thereby obtaining a polyamide solution. The obtained polyamic acid solution was coated on one side of a Nippon Electric Glass glass plate OA10G of 370 mm × 470 mm and 0.7 mm thickness using a rod coater, dried at 70° C. for 7.5 minutes, and then dried at 120° C. for 7.5 minutes. Heating was performed in an inert oven at 300°C for 20 minutes in a nitrogen atmosphere. Polyamide acid is converted into polyimide, and a laminate L6 of an engineering plastic film/inorganic substrate including a polyimide film and a glass plate, which is the engineering plastic film F6, is obtained. Table 1 shows the bonding strength Fa between the engineering plastic film and the glass plate of the obtained laminated body, the surface roughness Ra of the surface of the glass plate opposite to the laminated surface of the engineering plastic film, etc. The resin film layer is peeled off from the laminated body L6 produced by the same method, and it is made into the engineering plastic film F6.

＜Manufacturing of engineering plastic film/inorganic substrate laminate L7＞ After replacing the reaction vessel with a nitrogen gas inlet pipe, a reflux pipe, and a stirring rod with nitrogen, 33.36 parts by mass of 2,2'-bis(trifluoromethyl)benzidine (TFMB) and 270.37 parts by mass of N-methyl were added. 2-pyrrolidone (NMP), and colloidal silicon oxide dispersed in dimethylacetamide was added so that the total polymer solid content of silicon oxide in the polyamide solution became 0.14% by mass. The dispersion ("SNOWTEX (registered trademark) DMAC-ST" manufactured by Nissan Chemical Industry) was completely dissolved, and then 9.81 parts by mass of 1,2,3,4-cyclobutane was added directly in a solid state in batches After adding tetracarboxylic dianhydride (CBDA), 11.34 parts by mass of 3,3',4,4'-biphenyltetracarboxylic acid, and 4.85 parts by mass of (ODPA), the mixture was stirred at room temperature for 24 hours. Thereafter, 165.7 parts by mass of DMAc was added for dilution to obtain a polyamide solution 11 with a solid content of 18 mass % and a reduced viscosity of 2.7 dl/g (molar ratio of TFMB//CBDA/BPDA/ODPA=1.00//0.48/ 0.37/0.15). Using a comma coater, this polyamide solution was applied to polyethylene terephthalate film A4100 (Toyobo Co., Ltd.) by a die coater so that the final film thickness became 20 μm. Made of) non-slip material surface. Dry it at 110°C for 10 minutes. The self-supporting polyamide film obtained after drying is peeled off from the A4100 film as the support, and passed through a pin tenter (pin tenter) with a pin seat equipped with pins. Insert the needle into the bottom and hook it, adjust the distance between the needle plates so that the film does not break and unnecessary slack is not generated, and transport it at 200°C for 3 minutes, 250°C for 3 minutes, and 300°C for 6 minutes. Heating under the conditions to carry out the imidization reaction. After that, the film was cooled to room temperature for 2 minutes, and the parts with poor flatness at both ends of the film were cut off with a cutting machine and rolled into a roll to obtain a 500-meter-wide engineering plastic film (polyimide film) F7 with a width of 450 mm. Using the obtained engineering plastic film F7, the same operation as the production of the engineering plastic film/inorganic substrate laminated body L1 was performed to obtain the engineering plastic film/inorganic substrate laminated body L7.

[Table 1] laminated body L1 L2 L3 L4 L5 L6 L7 Engineering plastic film Upilex 25S Kapton 100H Xenomax F38LR Vecstar CTQ-25 Neopulim Liquid resin 6FDA/TFMB Trial film Film thickness [μm] 25 25 38 25 18 12 25 Inorganic substrate Glass plate(OA10G) Glass plate(OA10G) Glass plate(OA10G) Glass plate(OA10G) Glass plate(OA10G) Glass plate(OA10G) Glass plate(OA10G) Inorganic substrate back surface roughness Ra [nm] 0.7 0.7 0.7 0.7 0.7 0.7 0.7 Adhesion strength Fa between film/inorganic substrate [N/cm] 0.08 0.28 0.25 0.12 0.45 0.32 0.22 Adhesion strength after heating at 120℃ for 1 hour [N/cm] 0.09 0.31 0.25 0.12 0.44 0.35 0.23

＜Protective film＞ The polyester (PET) film and polypropylene (PP) film shown in Table 2 were used as the base film of the protective film, and the adhesive material shown in Table 2 was similarly coated to produce protective films P1 to P6. In addition, the surface roughness in Table 2 represents the surface roughness of the side of the protective film base material opposite to the adhesive layer.

[Table 2] protective film P1 P2 P3 P4 P5 P6 Base film PET PET PET PP Non-slip PET PET thickness μm 25 50 75 50 25 50 Surface roughness Ra * ⁾ μm 0.017 0.031 0.037 0.12 0.003 0.034 Surface roughness Rt *) μm 0.14 0.21 0.32 0.23 0.08 0.22 The average interval between bumps and bumps Sm μm 20.3 21.5 57.9 34.4 18.7 43.5 adhesive material Polysilicone series Polysilicone series Acrylic Acrylic Urethane series Urethane series Adhesive material thickness μm 12 20 25 25 20 12 Friction coefficient (against glass back) 0.28 0.13 0.23 0.12 0.53 0.13 *) Surface roughness of the protective film substrate on the opposite side to the adhesive layer

＜Adhesion strength between protective film and engineering plastic film＞ Combine the engineering plastic films F1 to F7 and the protective films P1 to P6 in turn, and measure the bonding strength Fp of each combination in the 90-degree peeling method. The results are shown in Table 3. In addition, the measurement was performed with N5, and was set as an average value. In addition, the bonding surface is the surface of the engineering plastic film opposite to the surface where the inorganic substrate (glass plate) is attached. After laminating the protective film and the engineering plastic film, the results of confirming the bonding strength after heating at 120°C were within 10% of the results reported in Table 3.

[table 3] Bonding strength Fp of protective film and engineering plastic film [N/cm] protective film P1 P2 P3 P4 P5 P6 Engineering plastic film F1 0.10 0.05 0.14 0.26 0.32 0.03 F2 0.09 0.05 0.14 0.24 0.36 0.04 F3 0.11 0.05 0.14 0.25 0.31 0.03 F4 0.10 0.04 0.14 0.26 0.37 0.04 F5 0.10 0.06 0.14 0.23 0.38 0.04 F6 0.09 0.05 0.15 0.23 0.36 0.05 F7 0.10 0.06 0.15 0.24 0.33 0.03

<Manufacture of laminate with protective film and measurement of bonding strength between engineering plastic film/inorganic substrate (glass plate)> Using the combination shown in Table 4, use a roller laminator to laminate the engineering plastic film/inorganic substrate A protective film is laminated on the body to obtain a laminate of an engineering plastic film with a protective film and an inorganic substrate (referred to as a laminate with a protective film). In addition, 7 sets of laminate systems with protective films are produced for each combination. The bonding strength between the engineering plastic film/inorganic substrate (glass plate) was measured using 3 sets of laminates with protective films among the 7 sets mentioned above. Make a "starting point" from the edge of the laminated body, peel the protective film base material/adhesive material/engineering plastic film uniformly by about 10mm, grasp this part, and calculate the 90-degree bonding strength Fb when peeling off from the glass plate. The results are shown in Table 4. Measured values are average values of N3. Regardless of whether there is a protective film or not, a value approximately equivalent to the bonding strength Fa between the engineering plastic film/inorganic substrate (glass plate) shown in Table 1 was obtained. [Table 4] Adhesion strength Fb [N/cm] when peeling off the engineering plastic film from the laminated body with protective film protective film P1 P2 P3 P4 P5 P6 Engineering plastic film/inorganic substrate laminate L1 0.08 0.09 0.08 0.07 0.08 0.09 L2 0.27 0.27 0.28 0.29 0.27 0.25 L3 0.25 0.25 0.25 0.26 0.24 0.24 L4 0.12 0.13 0.12 0.12 0.12 0.16 L5 0.46 0.44 0.43 0.46 0.45 0.39 L6 0.32 0.31 0.31 0.31 0.34 0.28 L7 0.37 0.34 0.35 0.34 0.31 0.33

＜Manufacture of laminate with protective film and measurement of protective film adhesion strength＞ The remaining 4 sets of the above-mentioned protective film-attached laminated body were used to determine the 90-degree bonding strength when the protective film was peeled off from the laminated body. The results are shown in Table 5. When the protective film adhesive material and the engineering plastic film are peeled off, the bonding strength value is recorded. However, when the protective film is peeled off, the engineering plastic film and the protective film are peeled off from the inorganic substrate (glass plate) as "×" ”. Measured values are average values of N3. This result shows that when the bonding strength Fb of the inorganic substrate (glass plate) and the engineering plastic film by the 90-degree peeling method, and the bonding strength Fp of the engineering plastic film and the protective film by the 90-degree peeling method, the relationship is Fp < Fb. , when peeling off the protective film, the engineering plastic film will not peel off from the inorganic substrate (glass plate) together with the protective film.

[table 5] Adhesion strength [N/cm] when the protective film is peeled off from the laminated body with the protective film protective film P1 P2 P3 P4 P5 P6 Engineering plastic film/inorganic substrate laminate L1 × 0.05 × × × 0.04 L2 0.09 0.04 0.14 0.25 × 0.05 L3 0.10 0.05 0.16 × × 0.04 L4 0.10 0.04 × × × 0.06 L5 0.09 0.05 0.15 0.26 0.34 0.04 L6 0.09 0.05 0.14 0.23 × 0.07 L7 0.11 0.07 0.18 0.25 0.34 0.03 ×: Peeling between the engineering plastic film and the inorganic substrate of the laminate

＜Evaluation of operability of laminate stacking with protective film＞ According to the results of the above-mentioned bonding strength measurement test, among the combinations in which the protective film can be peeled off from the engineering plastic film (the combination in which the engineering plastic film is not peeled off from the inorganic substrate), 10 sets of laminates with protective films were prepared for each combination. In each of the obtained combinations, 10 sets of laminated bodies with a protective film were overlapped in the horizontal direction on a flat table with the glass plate downward to make a laminated body with a protective film. Stack on top a glass plate of the same size, a polyethylene film with a thickness of 50 μm, and a polysiloxane rubber sheet with a thickness of 3 mm and the same size as the glass plate. Place a stainless steel plate with a thickness of 10 mm as a load and let it stand at room temperature. 10 days. After 10 days, remove the load, silicone rubber sheet, and polyethylene film, and manually confirm whether the protective films can be removed one by one from the stack of 10 sets of laminates with protective films. The layered body. As a result, the case where the product could be taken out without any particular problem was regarded as good operability "○", and the case where any problem occurred when taking out the laminated body with the protective film was regarded as poor operability "●". The results are shown in Table 6. In addition, in most cases of poor operability, the back side of the glass plate and the protective film are in close contact, and when the glass plate is lifted, the lower set of protective films peels off.

[Table 6] The operability of laminate stacking protective film P1 P2 P3 P4 P5 P6 Engineering plastic film/inorganic substrate laminate L1 - ○ - - - ○ L2 ● ○ ○ ○ - ○ L3 ● ○ ○ - - ○ L4 ● ○ - - - ○ L5 ● ○ ○ ○ ● ○ L6 ● ○ ○ ○ - ○ L7 ● ○ ○ ○ - ○ Example ○: Comparative example with good operability ●: Comparative example with poor operability -: Excluded from the test

＜Evaluation of transportability of stacked laminates with protective film＞ Among the combinations of laminated bodies that were found to have good handleability in the aforementioned handleability evaluation, 10 sets of each were aligned and overlapped to prepare a stack of laminated bodies with a protective film. Wrap the laminate with a protective film in kraft paper and stack it, put it into a corrugated board box together with a polyurethane buffer material with a thickness of 20mm, stack it on the platform of a small truck, and transport it for 30km on a general national highway. Unpack the product at the destination and evaluate the operability again using the method described above. There is no particular problem in any combination, and the laminated body with the protective film can be removed. In addition, there were no accidents such as glass breakage during transportation. [Possibility of industrial application]

As described above, the inorganic substrate/engineering plastic film laminate system with a protective film of the present invention has excellent handleability and transportability, can be operated with the engineering plastic film surface protected by the protective film, and can be used to treat the engineering plastic. If the film surface is processed, the protective film can be peeled off without any problem. The present invention can be effectively used in the production of flexible devices and the like by performing fine processing on the engineering plastic film and then peeling the engineering plastic film from the inorganic substrate using such a laminate.

1:Glass substrate 2: Engineering plastic film 3: Adhesive material layer of protective film 4: Protective film base material 100: Glass/engineering plastic film laminate 150:Protective film 200:Laminated body with protective film 300: Laminated body stack with protective film

FIG. 1 is a schematic diagram showing the cross-sectional structure of the inorganic substrate/engineering plastic film laminate. FIG. 2 is a schematic diagram showing the cross-sectional structure of the protective film. FIG. 3 is a schematic diagram showing the cross-sectional structure of an inorganic substrate/engineering plastic film laminate with a protective film. FIG. 4 is a schematic diagram showing a stacked cross-sectional structure in which four inorganic substrate/engineering plastic film laminates with protective films are stacked.

200:Laminated body with protective film

300: Laminated body stack with protective film

Claims (10)

An inorganic substrate/engineering plastic film laminate with a protective film, which is characterized by: an inorganic substrate/engineering plastic film with a protective film including an inorganic substrate, an engineering plastic film, an adhesive layer of the protective film, and a protective film base material in this order. In the engineering plastic film laminate, the bonding strength Fb of the inorganic substrate and the engineering plastic film using the 90-degree peeling method, and the bonding strength Fp of the engineering plastic film and the protective film using the 90-degree peeling method have a relationship of Fp<Fb, and The surface roughness Ra of the surface of the protective film base material opposite to the adhesive layer is in the range of 0.02 μm to 1.2 μm. The inorganic substrate/engineering plastic film laminate with a protective film as claimed in claim 1, wherein the surface of the protective film substrate opposite to the adhesive layer and the surface of the inorganic substrate not opposite to the engineering plastic film The kinetic friction coefficient between them is in the range of 0.02~0.25. For example, the inorganic substrate/engineering plastic film laminate with a protective film according to claim 1 or 2, wherein the surface roughness Ra of the surface of the inorganic substrate not facing the engineering plastic film is in the range of 0.01~2nm. For example, the inorganic substrate/engineering plastic film laminate with a protective film according to claim 1 or 2, wherein the bonding strength Fb of the inorganic substrate and the engineering plastic film is in the range of 0.02~0.3N/cm. For example, the inorganic substrate/engineering plastic film laminate with a protective film according to claim 1 or 2, wherein the bonding strength Fp of the engineering plastic film and the protective film is in the range of 0.01~0.27N/cm. For example, the inorganic substrate/engineering plastic film laminate with a protective film according to claim 1 or 2, wherein the diameter of the circumscribed circle of the inorganic substrate is 310mm or more. For example, if the inorganic substrate/engineering plastic film laminate with a protective film in claim 1 or 2 is left in an environment of 23°C and 50% RH for more than 24 hours, the side of the protective film base material opposite to the adhesive material The surface resistance of the surface is in the range of 1×10 ⁶ ~1×10 ¹⁰ [Ω]. An inorganic substrate/engineering plastic film laminate with a protective film is stacked, which is characterized in that the inorganic substrate/engineering plastic film laminate with a protective film according to any one of claims 1 to 7 is oriented in the layer direction. Overlap 4 or more pieces in the same direction. A method of storing an inorganic substrate with a protective film/engineering plastic film laminate, characterized by packaging and storing the inorganic substrate with a protective film/engineering plastic film laminate in a stacked state as claimed in claim 8. A method of transporting an inorganic substrate with a protective film/engineering plastic film laminate, characterized by packaging and transporting the inorganic substrate with a protective film/engineering plastic film laminate in a stacked state as claimed in claim 8.