JP2013071375A - Release agent, cushioning material using the same, and hot-press molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release agent which, even if hot-press molding (particularly, high-temperature vacuum press molding) is performed while interposing a cushioning material arranged with a metal sheet as a surface material and optionally a backing plate, between a hot plate and an article to be molded, prevents seizure of the metal sheet on the hot plate or the backing plate in contact with the metal sheet, is nonflammable, does not generate a gas, has high heat-resistant durability, prevents a hot-press molding apparatus or a molded article from being contaminated, is excellent in uniform adhesion to a metal, film forming, safety and simplicity in handling, and is reduced in cost.SOLUTION: The release agent is an aqueous solution which includes, as the solid content, a swelling layered smectite group clay mineral as a main material, and an inorganic metal-absorbing agent as an auxiliary agent selected from a cerium hydroxide, a cerium oxide, a zeolite and a schwertmannite, and the solid content does not substantially contain a graphite and substantially consists of only the inorganic substances.

Description

  The present invention relates to a hot press molding apparatus in order to apply heat and pressure evenly to the entire surface of a molded object in a hot press molding process performed when manufacturing a synthetic resin laminate, a printed circuit board, or the like. When the cushioning material used between the molded product and the surface of the metal sheet is arranged on the surface of the cushioning material, a seizure phenomenon will occur with the metal heating plate or backing plate that comes in contact with the cushioning material. The present invention relates to a mold release agent for preventing this, a cushion material using the mold release agent, and a hot press molding method.

  Conventionally, a process of laminating and bonding molded articles by vacuum heating and pressurization has been mainly performed in a hot press molding process. As an example, there is a process of manufacturing a flexible printed circuit board (hereinafter referred to as FPC (Flexible Printed Circuits)). Recent FPCs are installed in HDD suspensions, hinges that connect the liquid crystal part of a mobile phone and a keyboard, slide parts of mobile phones, etc., so they are thin to prevent bending, disconnection, and short-circuiting when bending repeatedly. High-strength super engineering plastic (hereinafter referred to as super engineering plastic) is used. As these super engineering plastics, polyimide (PI), liquid crystal polymer, and the like are used, and a pressing temperature exceeding 300 ° C. is performed.

Therefore, usually, in the manufacturing process of FPC, a PI film, a liquid crystal polymer film, etc. and a copper foil are laminated, in a reduced pressure atmosphere close to a vacuum of about 10 ⁻² Pa, at a high temperature of about 300 to 350 ° C., for several hours, Hot press molding (high-temperature vacuum pressure molding) is performed at a pressure of about 30 to 100 kgf / cm ² . In order to uniformly apply a certain pressure and heat to the laminated printed wiring board (molded article), a heat-resistant cushioning material is used. For example, a papermaking sheet mainly composed of inorganic fibers such as rock wool fibers, slag fibers, glass fibers, basalt fibers, alumina fibers, silica fibers, and carbon fibers. The paper-making type sheet is a cushioning material that is required to have a function of uniformly applying a constant pressure and heat to the molding, and has an advantage in that a sheet with a more uniform thickness can be obtained. By using inorganic fibers of 4 μm or less (further 1.5 μm or less), the effect is further enhanced.

  However, cushioning materials made of paper-made sheets, when subjected to hot press molding as they are, are scattered and contaminated with products (forms) and machines (hot press molding equipment). It is common to coat and prevent fiber scattering. Since the use environment is a high temperature of 300 ° C. or more, as a sheet-like surface material that can be used, some super engineering plastics such as PI sheets and metal foils such as aluminum, copper, stainless steel, silver, and gold can be considered. Judging from price, supply and demand, and handling, aluminum foil is often used in practice.

However, recently, in order to integrate a more special super engineering plastic and copper foil, high-temperature vacuum press molding with higher pressure may be performed, for example, at about 350 ° C. and 20 MPa pressure for 5 hours. There is a molding condition of 10 ⁻² Pa under vacuum. When high-temperature vacuum pressure molding is performed under such conditions, the aluminum foil, which is the surface material of the cushion material, is baked on the hot platen or stainless steel plate (caulking plate) used in the hot press molding device. After molding, there is a problem that it is difficult to remove the cushioning material, workability is poor, and production cannot be performed.

  As another manufacturing method for forming at high temperature, there is a die casting method of aluminum. However, it is common sense to use a release agent in order to prevent the phenomenon of aluminum sticking to the mold. In the past, so-called oil-based mold release agents have been used as mold release agents for die casting, but oil ignites and causes fires at temperatures above 300 ° C, and is slippery and dangerous when scattered on the floor, Due to environmental demerits such as the generation of malodors, it has now shifted to a water-soluble release agent, accounting for 99%.

  Therefore, a water-soluble mold release agent for die casting is used in the above-described high-temperature vacuum pressure molding (heat press molding in which the aluminum foil causes a seizure phenomenon) with an aluminum foil or a hot press molding device as a surface material of the cushion material. It is conceivable that it is applied to a hot plate or a stainless plate (caulking plate) to be used, dried and used. However, the usual water-soluble mold release agents use surfactants called dispersants in order to form emulsions in which a small amount of oil, silicone resin / wax, and graphite are the main ingredients, and these are uniformly dispersed in water. ing. Therefore, when a water-soluble mold release agent is used at a high temperature of 300 ° C. or higher, the contained organic matter decomposes to generate gas, which contaminates the product (molded product) and the machine (hot press molding device). However, there is a problem that it takes a long time to create a vacuum state and the production efficiency is greatly reduced.

  Further, the surfactant of the dispersant has a problem of influence on environmental hormones, and it is required to select a surfactant having a low environmental load. For example, an alkyl polyether having an alkyl group having 12 to 15 carbon atoms. Is designated as a designated chemical substance that is required to emit PRTR (Pollutant Release and Transfer Register) as a chemical substance that is concerned about its environmental impact, and its use is restricted. Alkyl ester type, sorbitan ester type, sorbitan ester ether type are known as corresponding nonionic surfactants, but when creaming of emulsion, oil separation, water separation, etc. occur, when actually used, There is a problem of poor dilution stability at low concentrations. Furthermore, in terms of the environment, the water-soluble release agent has a problem that the working amount is deteriorated or the waste liquid needs to be processed because the amount of application increases.

  Solid lubricants are well known as release agents that are less affected by the above problems and do not decompose at high temperatures. For spray types that are not water-soluble, typical examples are molybdenum disulfide, graphite, and boron nitride. Is. Although it is not common, nanocarbon, graphene, nanodiamond, etc. may be commercially available in the future, but they are very expensive and are excluded from the evaluation target at present.

  Molybdenum disulfide is a natural product and is relatively inexpensive (however, the commercial spray price is 980 yen for 420 ml), and moreover, it adheres well to metal and easily forms a release layer film. It is used, but when it exceeds 300 ° C, it gradually oxidizes in the air and decomposes into molybdenum trioxide and sulfur oxide. The decomposed sulfur oxides contaminate the metal and become sulfides, so it takes time to contaminate the product (molded product) and the machine (hot press molding equipment) or to create a vacuum, greatly increasing production efficiency. There is a problem of lowering. Therefore, molybdenum disulfide is difficult to apply.

  Graphite has a heat-resistant temperature of 400 ° C., and if the temperature condition of the high-temperature vacuum pressure molding is 350 ° C., the temperature tolerance is small and there is a concern about thermal decomposition. In addition, there is a problem that products (molded articles) and machines (hot press molding apparatus) are contaminated in black. Therefore, graphite is difficult to apply. Graphite is more than twice as expensive as molybdenum disulfide.

  Boron nitride has a heat-resistant temperature as high as 900 ° C. in air and 1200 ° C. in vacuum, and there is no problem in heat resistance even when the temperature condition of high-temperature vacuum pressure molding is 350 ° C. However, since boron nitride itself does not have adhesiveness to metals or the like, it is a fact that a small amount of an organic binder is added. Therefore, if the temperature condition of the high-temperature vacuum pressure molding is 350 ° C., the contained organic matter is decomposed to generate gas, so that the product (molded product) and the machine (hot press molding device) are contaminated or vacuum is applied. There is a problem that it takes a long time to make the state, and the production efficiency is greatly reduced. Therefore, boron nitride is difficult to apply. Boron nitride is not a natural product but a synthetic product, and is three times more expensive than molybdenum disulfide.

Therefore, in view of the above-described conventional problems, the present invention provides heat that is performed by interposing a cushioning material in which a surface material of a metal sheet is disposed between a hot platen and a molded object, and a backing plate as necessary. Perform press molding, particularly high-temperature vacuum pressing for several minutes to several hours at a high temperature of 300 ° C. or higher in a reduced-pressure atmosphere (for example, 10 ⁻² Pa vacuum atmosphere, 350 ° C., 20 MPa pressure, 5 hours). In addition to preventing seizure of a hot plate or a backing plate that comes into contact with a metal sheet, it is nonflammable, does not generate gas, has good heat resistance and durability, and may contaminate a hot press molding device or a workpiece. Another object of the present invention is to provide a mold release agent that has good uniform adhesion to metal and film formation, is safe and easy to handle, and is inexpensive, a cushioning material using the mold release agent, and a hot press molding method.

  In order to achieve the above object, the release agent of the present invention has a plate-like shape in which a surface material of a metal sheet is arranged between a hot platen of a hot press molding apparatus and a molding as described in claim 1. A mold release agent for preventing seizure between the heat plate or the contact plate in contact with the metal sheet in hot press molding performed by interposing a cushion material and a contact plate as necessary. , An aqueous solution containing, as a solid content, a smectite group-swelling layered clay mineral as a main material and an inorganic metal adsorbent selected from cerium hydroxide, cerium oxide, zeolite, and Schwertmannite as an auxiliary material, The solid content is substantially free of graphite and is substantially composed only of an inorganic substance.

  The mold release agent according to claim 2 is characterized in that, in the mold release agent according to claim 1, the smectite group swellable layered clay mineral is a synthetic smectite.

  The release agent according to claim 3 is the release agent according to claim 1 or 2, wherein the inorganic metal adsorbent is cerium hydroxide.

  The mold release agent according to claim 4 is the mold release agent according to any one of claims 1 to 3, wherein the aqueous solution contains 0.4 to 4% by weight of the solid content, Includes 75 to 98 wt% of the smectite group swellable layered clay mineral and 2 to 25 wt% of the inorganic metal adsorbent.

  Moreover, the cushion material of this invention is a plate-shaped cushion material which arranged the surface material of the metal sheet interposed between the hot platen of a hot press molding apparatus, and a to-be-molded object as described in Claim 5. Then, the release agent according to any one of claims 1 to 4 is attached to the outer surface of the surface material in the form of a film and dried to form a solid film of the release agent. It is characterized by that.

  Moreover, the hot press molding method of the present invention is a plate-like cushion material in which a surface material of a metal sheet is disposed between a hot platen of a hot press molding apparatus and a molded object, as described in claim 6. A hot press molding method that is performed with a backing plate as necessary, wherein the cushion material is the cushion material according to claim 5, and an adhesion surface of the release agent is the hot plate and / Or abutting against the abutting plate.

  Moreover, the hot press molding method of the present invention is a plate-like cushion material in which a surface material of a metal sheet is arranged between a hot platen of a hot press molding apparatus and a molded object, as described in claim 7. It is a hot press molding method performed by interposing a backing plate as necessary, and any one of claims 1 to 4 on the contact surface of the surface material with the heating plate and / or the backing plate The mold release agent according to Item 1 is attached in a film shape to form a solid film of the mold release agent.

  Moreover, the hot press molding method of the present invention, as described in claim 8, is a plate-like cushion material in which a surface material of a metal sheet is disposed between a hot platen of a hot press molding apparatus and a molded object, It is a hot press molding method performed by interposing a backing plate as necessary, and any one of claims 1 to 4 is provided on a contact surface of the hot plate and / or the backing plate with the surface material. The mold release agent according to Item 1 is attached in a film shape to form a solid film of the mold release agent.

According to the present invention, hot press molding performed by interposing a cushioning material in which a surface material of a metal sheet is disposed between a hot platen and a workpiece and a backing plate as necessary, particularly in a reduced pressure atmosphere. Heat that makes contact with the metal sheet even if high-temperature vacuum pressing is performed at a high temperature of 300 ° C. or higher for several minutes to several hours (for example, a vacuum atmosphere of 10 ⁻² Pa, 350 ° C., pressure of 20 MPa, 5 hours). Prevents seizure of the panel and backing plate, is non-flammable, does not generate gas, has good heat resistance and durability, and does not contaminate the hot press molding equipment or workpieces, and evenly adheres to metal In addition, it is possible to provide a release agent that has good film formation, is safe and easy to handle, and is inexpensive. That is, the mold release agent of the present invention is a smectite-swelling layered clay mineral that has a laminar structure and a lubrication and peeling function as a main material, and an inorganic material that provides an adhesion function to a metal as an auxiliary material. It is an aqueous solution containing a metal adsorbent (one or more of cerium hydroxide, cerium oxide, zeolite, and Schwertmannite) as a solid component, and the surface of the hot platen, backing plate, and cushion material by the action of the metal adsorbent. A uniform release layer coating of smectite group swellable layered clay mineral can be formed on a metal surface such as a material (metal sheet) with good adhesion, and in contact with the metal sheet even in high-temperature vacuum pressing at 300 ° C. or higher. It is possible to satisfactorily prevent seizure of the heating plate and the backing plate. In addition, since the constituent materials are only water and inorganic substances, and there are no environmentally problematic solvents, hot press molding with a release layer after drying is performed at 300 ° C or higher high temperature vacuum press molding. However, it has various advantages such as non-combustion, no gas generation, safety, and no contamination of machinery and products.

Photograph of the state of the cushion material surface (contact surface with the stainless steel plate) when the heat press test of the example was performed (in air, 300 ° C., 20 MPa, 1 hour) Photograph of surface (contact surface with cushioning material) after water washing of stainless steel plate when heat press test of example (in air, 300 ° C., 1 hour at 20 MPa)

  The mold release agent of the present invention is a plate-like cushion material in which a surface material of a metal sheet (mainly metal foil) is arranged between a hot plate (mainly metal) of a hot press molding apparatus and a molding target ( In order to prevent seizure between the hot platen or the contact plate that comes into contact with the metal sheet in hot press molding performed mainly by interposing an inorganic fiber sheet) and, if necessary, a contact plate (mainly a metal plate). It is an aqueous solution containing, as a main component, a smectite group-swelling layered clay mineral that provides lubricity and exfoliation functions as a solid content. In addition, the hot platen of the hot press molding apparatus refers to a press substrate in which a hot wire or a heat medium is piped, and is mainly made of metal. In addition, the backing plate is a member used as necessary in hot press molding, and the workability and surface smoothness of the molded product are increased between the hot platen and the cushion material and / or between the cushion material and the molded product. It is a general term for mirror plates and the like that are used to increase the height, and is mainly made of metal.

  As the smectite swellable layered clay mineral, natural products and synthetic products can be used. However, natural products are likely to contain impurities, and therefore it is preferable to use synthetic products (synthetic smectites). In addition, when the synthetic product is dispersed in water, it has a higher viscosity than that of a natural product, and a small coating amount can be obtained with a small amount, and a thin coating film can be obtained. This is because when the compound is dispersed in water, it swells and disperses, and its unit layer becomes a very thin plate shape with a thickness of about 1 nm and a spread of 100 to 1000 nm. It is easy to form and has a structure that is slippery along the surface of each layer to obtain good lubricity and good peelability that does not cause seizure to metal. The heat resistant temperature of the smectite group swellable layered clay mineral is about 700 ° C. In addition, natural mica and synthetic mica are known as other scaly inorganic substances, but those having an average particle size of 3 μm or less cannot be obtained, and the lubricity and peelability are inferior due to the large size.

  The smectite swellable layered clay mineral refers to montmorillonite, beidellite, nontronite, saponite, hectorite, soconite, stevensite, and the like. Examples of the synthetic smectite include chemical synthetic products such as hectorite, saponite, stevensite, beidellite, montmorillonite, and nontronite, or substituted products, derivatives, or mixtures thereof. Examples of commercially available synthetic smectites include “Lucentite” (Coop Chemical Co., synthetic hectorite), “Smecton” (Kunimine Industries Co., Ltd., synthetic saponite), and the like. Synthetic smectite is a pure artificially synthesized material, and its properties such as swelling and thixotropy are equal to or better than natural bentonite, but it does not contain impurities, so the viscosity range can be adjusted by adding a small amount. And contributes to dripping prevention. Synthetic smectite becomes a thixotropic dispersion when dispersed in water, has a function of obtaining a stable viscosity and increasing the specific surface area.

  As described above, the mold release agent of the present invention is an aqueous solution containing, as a main component, a smectite group-swelling layered clay mineral that provides lubricity and exfoliation functions as a solid content. Smectite group swellable layered clay mineral is an inorganic substance, and has a film-forming property when used in a wet state after being dispersed in a solvent. It is difficult to obtain a uniform film (uniform film). Therefore, in order to uniformly adhere to the metal surface, a component serving as an auxiliary material for bonding the smectite group swellable layered clay mineral and the metal is required. In general, organic compounds such as surfactants and oils can be considered as materials that facilitate adhesion to metals. However, since the release agent of the present invention is used at a high temperature of 300 ° C. or higher, these materials are Difficult to apply.

  As a result of intensive studies, a metal adsorbent was considered as a component that can serve as an auxiliary material for bonding the smectite group-swelling layered clay mineral and the metal. Well-known heavy metal adsorbents include so-called chelating agents such as ethylenediaminetetraacetic acid. Furthermore, lignin, tannin (a kind of polyphenol) and the like are known, and some of them have already been sold and have already been introduced in the treatment for fixing heavy metals in soil. However, ethylenediaminetetraacetic acid has a decomposition temperature of 240 ° C., and a toxic gas of nitrogen oxide is generated at the time of decomposition. Therefore, it is difficult to apply to ethylenediaminetetraacetic acid at high temperatures of 300 ° C. or higher. In addition, lignin has a decomposition temperature of 420 ° C. and is in a range that can be used as an adhesion aid for high temperature applications of 300 ° C. or higher. There is a risk of distilling out, and there are concerns about safety and it is difficult to apply. Tannin does not generate harmful substances, but has a melting point as low as 210 ° C., so it is difficult to apply tannin to high temperature applications of 300 ° C. or higher.

  Inorganic metal adsorbents include schbert manite, zeolite (zeolite), calcium fluoride (fluorite), cerium hydroxide, etc., and these have already been introduced as heavy metal immobilization agents in soil. There are sales results.

Synthetic schwertmannite, which is an iron compound, is a mineral containing iron as a main component, which was recently named as 1994, and has a structure containing sulfuric acid. Fe ₈ O ₈ (OH) _6-2x (SO ₄ ) _x (1 <X <1.75), and a metal component is taken in and fixed to the sulfuric acid portion. Although the melting point exceeds 1000 ° C., it is expensive at 3500 yen / kg, and there is concern about cost.

Zeolite is a porous ore mainly composed of aluminum silicate, and there are natural products and synthetic products. Structurally, it has a tetrahedral structure and is represented by (SiO ₄ ) ⁴ + (AlO ₄ ) ⁵⁻ . Since the adsorption mechanism is mainly physical adsorption inside the porous body, when it is mixed with the smectite group swellable layered clay mineral and applied, it is pulverized into a fine powder of 1 μm or less. It is considered that the adsorption performance is reduced due to a decrease in the amount, and is not optimal for use as an adhesion aid. In addition, a synthetic product with few impurities is as expensive as 2000 yen / kg, and there is anxiety in terms of cost.

Calcium fluoride is a material used for glass raw materials and soil heavy metal adsorbents as CaF ₂ and is mainly a natural product. Although it has a high melting point of 1360 ° C. and high temperature resistance, it is a substance that causes serious damage to human eyes. It causes eye irritation and skin irritation, and is uneasy in terms of safety and difficult to apply. In addition, it is expensive at 7500 yen / kg and is difficult to apply.

Cerium hydroxide is the most abundant rare earth material and is inexpensive at several hundred yen / kg, and its use as an abrasive for glass lenses and recently as a metal adsorbent is known. Compared with other adsorbents, anion adsorption performance is excellent. The structure is shown as Ce (OH) ₃ .nH ₂ O or Ce (OH) ₄ .nH ₂ O, and the metal adsorption is said to be due to the following reaction.
(1) Ce—OH + MO ₂ · H ₂ O → Ce—O—MO · H ₂ O
(2) Ce—OH + MO _2. (OH) ₂ → Ce—O ₂ —MO (OH) ₂
^{(3) 2Ce-OH + MO} 2- → 2Ce (MO) + 2OHCe -
Here, M represents a metal atom.
Toxicity is extremely low and safety is high. Heat resistant up to 800 ° C and stable. When it exceeds about 900 ° C., it completely changes to cerium oxide. Cerium oxide has a melting point of about 1950 ° C. and is a safe substance that is used in cosmetics as an ultraviolet protection material.

  Therefore, as a solid content of the release agent of the present invention, as an inorganic metal adsorbent as an adhesion auxiliary material used in combination with the smectite group swellable layered clay mineral of the main material, cerium hydroxide, cerium oxide, zeolite, Schwbert One or more types of knight can be used, and among them, cerium hydroxide is preferable in terms of safety and cost.

  Therefore, the mold release agent of the present invention includes a smectite group-swelling layered clay mineral that provides lubricity and exfoliation functions as a main material, and an inorganic metal adsorbent that provides an adhesion function to a metal as an auxiliary material. (One or more of cerium hydroxide, cerium oxide, zeolite, and Schwertmannite) as an aqueous solution. Further, the solid content of the release agent is substantially free of graphite (graphite) and is substantially composed only of an inorganic substance.

  Moreover, it is preferable that solid content of a mold release agent contains a smectite group swelling layered clay mineral 75 to 98 weight%, and an inorganic type metal adsorbent 2 to 25 weight%. Since the smectite group-swelling layered clay mineral is a main material that provides lubricity and exfoliation functions, it is preferably included in a large amount. However, as described above, an inorganic metal adsorbent that provides an adhesion function with metals. If it does not contain (one or more of cerium hydroxide, cerium oxide, zeolite, and Schwertmannite), smectite group swellable layered clay on the metal surface such as a hot platen, backing plate, cushioning material (metal sheet) Since a release layer film having a uniform thickness of mineral cannot be formed with good adhesion, the inorganic metal adsorbent is contained in an amount of 2% by weight or more, and the smectite group swelling layered clay mineral is contained in an amount of 98% by weight or less. It is preferable to do so. If the content of the inorganic metal adsorbent exceeds 25% by weight, the inorganic metal adsorbent peels off and falls off during the drying process after attaching the mold release agent or hot press molding using the mold release agent. Is likely to occur, and an excessive amount exceeding the necessary amount as an auxiliary material for imparting adhesiveness is not preferable. For this reason, the content of the inorganic metal adsorbent is more preferably 3% by weight or more, and more preferably 10% by weight or less.

  The release agent is an aqueous solution containing a smectite group swellable layered clay mineral and an inorganic metal adsorbent (one or more of cerium hydroxide, cerium oxide, zeolite, and Schwertmannite). It is preferable to contain 0.3 to 3% by weight of the swellable lamellar clay mineral and 0.1 to 1% by weight of the inorganic metal adsorbent, and 0.4 to 4% by weight of the solid content. It is preferable to make it. If the content of the smectite swellable layered clay mineral is less than 0.3% by weight, the thixotropic property of the aqueous solution is low and the viscosity is low, and the inorganic metal adsorbent cannot be uniformly dispersed. If it exceeds, the viscosity of the aqueous solution becomes too high (several tens of Pa.s or more), the fluidity is deteriorated, and it is difficult to uniformly adhere, so this is not preferable. Therefore, the viscosity of the aqueous solution is 5 to 50 Pa.s. s, and further 10 to 50 Pa.s. It is preferable that it is s. In addition, if the content of the inorganic metal adsorbent is less than 0.1% by weight, wetting of the release agent with respect to the metal surface is worsened, and the adhesion of the release agent is reduced, which is not preferable. If it exceeds, the inorganic metal adsorbent will peel off easily during the drying process after attaching the mold release agent, or during hot press molding using the mold release agent, and the powder will fall off. As an auxiliary material, the excessive amount exceeds the necessary amount, which is not preferable.

  The cushion material of the present invention is a plate-like body in which a surface material of a metal sheet is arranged and used between a hot platen of a hot press molding apparatus and a molding, and on the outer surface of the surface material, The release agent of the present invention is attached to a film and dried to form a solid content film of the release agent.

  Since the cushion material of the present invention is used at a high temperature of 300 ° C. or higher, the main body is a sheet mainly composed of inorganic fibers, in particular, a non-woven sheet mainly composed of inorganic fibers, and in particular, a papermaking sheet mainly composed of inorganic fibers. As the inorganic fiber, rock wool fiber, slag fiber, glass fiber, basalt fiber, alumina fiber, silica fiber, carbon fiber and the like can be used, and glass fiber is preferable in that a fiber having a small fiber diameter can be easily obtained. The paper-making type sheet is a cushioning material that is required to have a function of uniformly applying a constant pressure and heat to the molding, and has an advantage in that a sheet with a more uniform thickness can be obtained. By using inorganic fibers of 4 μm or less (further 1.5 μm or less), the effect is further enhanced.

  The nonwoven fabric sheet mainly composed of inorganic fibers, in particular, the cushion material composed of the nonwoven sheet mainly composed of inorganic fibers having an average fiber diameter of 4 μm or less (more preferably 1.5 μm or less) is mainly due to breakage of the fibers themselves during hot press molding. In order to cause fiber scattering and contaminate the hot press molding apparatus and the molding object, a surface material is disposed on the cushion material body mainly composed of inorganic fibers to prevent this. As the surface material, a metal sheet such as a metal foil (usually a nonporous sheet having a uniform thickness of 10 to 100 μm) is used. Aluminum foil is usually used in consideration of cost, availability, and handleability. The surface material is disposed on the front and back surfaces of the cushion material body, which is a plate-like body, or on the entire surface, but is generally disposed on the entire surface in order to reliably prevent fiber scattering.

  One embodiment of the hot press molding method of the present invention includes a plate-like cushion material in which a surface material of a metal sheet is disposed between a hot platen of a hot press molding apparatus and an object to be molded, and a backing plate as necessary. The cushioning material is used in which the release agent of the present invention is attached to the outer surface of the surface material in the form of a film and dried to form a solid film of the release agent. The release agent adhering surface is brought into contact with the heating plate and / or the backing plate.

  Another embodiment of the hot press molding method of the present invention includes a plate-like cushion material in which a surface material of a metal sheet is disposed between a hot plate of a hot press molding device and a molding, and a backing plate as necessary. The release agent of the present invention is attached in the form of a film to the contact surface of the surface material with the heating plate and / or the backing plate, so that a solid content coating of the release agent is formed. It is designed to be formed.

  Another embodiment of the hot press molding method of the present invention includes a plate-like cushion material in which a surface material of a metal sheet is disposed between a hot plate of a hot press molding device and a molding, and a backing plate as necessary. The release agent of the present invention is attached in the form of a film to the contact surface with the surface material of the heating plate and / or the backing plate, and a solid coating of the release agent is formed. It is designed to be formed.

An example is given about the manufacturing method of the mold release agent of this invention, and the method of applying the mold release agent of this invention to a cushioning material or a hot press molding apparatus.
(1) A smectite group swelling layered clay mineral powder (main material) is weighed to a specified concentration.
(2) Using an pulverizer, measure an inorganic metal adsorbent powder (auxiliary material) such as cerium hydroxide having an average particle diameter of 1 μm or less so as to have a specified concentration.
(3) Add the above two types of powder to water (pure water or ion-exchanged water), put into a stirrer (homogenizer), stir for 5 minutes to uniformly disperse, and thixotropic smectite group swelling layer A mixed aqueous solution (release agent) of clay mineral and inorganic metal adsorbent is obtained.
(4) Applying the above mold release agent by spraying, roll coater, doctor coater, or other dipping method using a dipping tank or the like, a hot platen of a hot press molding device, a backing plate, a cushioning material surface material, etc. A solid coating of the mold release agent is applied to a part or the whole of the outer surface (a contact surface between a hot plate or a backing plate of a hot press molding apparatus and a cushioning material) and dried. To form.

Next, examples of the present invention will be described in detail together with comparative examples and conventional examples. Table 1 shows the evaluation results of Examples, Comparative Examples 1-2 and Conventional Examples 1-2. Moreover, the photograph of the hot press test result of an Example, the comparative example 1, and the prior art examples 1-2 is shown to FIGS.
(Example)
<Production of cushion material>
After dispersing and mixing 100% by weight of C glass short fibers having an average fiber diameter of 1.0 μm in water, wet-making with a normal paper machine, drying at 105 ° C., thickness 3.0 mm, basis weight 420 g / m A glass fiber papermaking sheet ² (cushion material body) was obtained. This glass fiber papermaking sheet was cut into a size of 40 mm × 40 mm and encapsulated (covered entirely) with a surface material of aluminum foil having a thickness of 40 μm to obtain a plate-like cushion material.
<Preparation of mold release agent>
25 g of synthetic smectite powder (Lucentite SWN manufactured by Coop Chemical Co., Ltd.) and 1 g of cerium hydroxide powder ground to an average particle size of 1 μm or less were collected, put into a stainless steel tank, 974 g of water was added, and a homogenizer (silver) (L4R, manufactured by Son Co., Ltd.) was stirred and dispersed uniformly for 5 minutes to obtain a 2.6 wt% aqueous solution (release agent) having thixotropic properties.
<Formation of release layer>
Two commercially available stainless steel plates (smooth plates) with a thickness of 0.2 mm are prepared, and a release agent is uniformly applied to each side with a doctor coater, and dried to form a solid film (release agent) of the release agent. Mold layer) was formed. The coating (release layer) had an average thickness of 36.0 μm and a standard deviation of 2.7 μm.
<Heat press test>
The cushion material was sandwiched between the two stainless steel plates so that the front and back surfaces of the cushion material were in contact with the release agent application surface (release layer) of the stainless steel plate and installed in a hot press testing machine. Next, the temperature of the hot press tester was raised to 300 ° C., 20 MPa pressure and 300 ° C. were applied to the cushion material, and hot pressing was performed for 1 hour. As the hot press tester, one having specifications of a hot plate size of 200 mm × 150 mm, a heating temperature of room temperature to 300 ° C., and a pressure of 0 to 15 t (manufactured by ASONE) was used. The surface condition, image sticking condition, appearance change, etc. of the stainless steel plate after the hot press test were observed.

(Comparative Example 1)
<Production of cushion material>
In the same manner as in Example, a cushion material similar to that in Example was obtained.
<Preparation of mold release agent>
No release agent was prepared.
<Formation of release layer, hot press test>
The hot press test was performed in the same manner as in the examples except that the stainless steel plate was used as it was without applying a release agent. The surface condition, image sticking condition, appearance change, etc. of the stainless steel plate after the hot press test were observed.

(Comparative Example 2)
<Production of cushion material>
In the same manner as in Example, a cushion material similar to that in Example was obtained.
<Preparation of mold release agent>
25 g of synthetic smectite powder (Lucentite SWN manufactured by Coop Chemical Co., Ltd.) is collected, put into a stainless steel tank, 974 g of water is added, and the mixture is uniformly dispersed by stirring for 5 minutes using a homogenizer (Silverson L4R). An aqueous solution (release agent) having a concentration of 2.5% by weight having thixotropy was obtained.
<Formation of release layer>
In the same manner as in the example, a release agent was applied to one side of two stainless steel plates and dried to form a release layer. The release layer had an average thickness of 41.5 μm and a standard deviation of 11.5 μm.
<Heat press test>
A hot press test was conducted in the same manner as in the example. The surface condition, image sticking condition, appearance change, etc. of the stainless steel plate after the hot press test were observed.

(Conventional example 1)
<Production of cushion material>
In the same manner as in Example, a cushion material similar to that in Example was obtained.
<Preparation of mold release agent>
A commercially available dry molybdenum disulfide lubricant (Aerolex Plus manufactured by Nippon NCH) was used.
<Formation of release layer>
In the same manner as in the example, a release agent (lubricant) was applied to one side of two stainless steel plates and dried to form a release layer. The release layer had an average thickness of 4.6 μm and a standard deviation of 3.2 μm.
<Heat press test>
A hot press test was conducted in the same manner as in the example. The surface condition, image sticking condition, appearance change, etc. of the stainless steel plate after the hot press test were observed.

(Conventional example 2)
<Production of cushion material>
In the same manner as in Example, a cushion material similar to that in Example was obtained.
<Preparation of mold release agent>
A commercially available boron nitride lubricant (Boron nitride spray manufactured by Shin-Etsu Chemical Co., Ltd.) was used.
<Formation of release layer>
In the same manner as in the example, a release agent (lubricant) was applied to one side of two stainless steel plates and dried to form a release layer. The release layer had an average thickness of 27.2 μm and a standard deviation of 6.3 μm.
<Heat press test>
A hot press test was conducted in the same manner as in the example. The surface condition, image sticking condition, appearance change, etc. of the stainless steel plate after the hot press test were observed.

1 and 2 show photographs of the hot press test results of Examples, Comparative Example 1, and Conventional Examples 1-2. FIG. 1 is a photograph of the state of the cushion material surface (contact surface with the stainless steel plate) after the hot press test, and FIG. 2 shows the surface after washing the stainless steel plate after the hot press test (with the cushion material). It is a photograph of a contact surface state.
<Figure 1>
(1) Upper left: In Comparative Example 1 (release agent: none), a seizure phenomenon occurred, and it was forcibly removed from the stainless steel plate.
(2) Lower left: In the example (release agent: aqueous solution of synthetic smectite and cerium hydroxide), the seizure phenomenon does not occur and it can be easily peeled off from the stainless steel plate, and the release agent is peeled off. Absent.
(3) Upper right: Conventional example 2 (release agent: commercially available boron nitride lubricant) has no seizure phenomenon and can be peeled off from the stainless steel plate, but peeling of the release agent is observed. .
(4) Lower right: Conventional Example 1 (release agent: commercially available molybdenum disulfide lubricant) has no seizure phenomenon and can be peeled off from the stainless steel plate, but the release agent is peeled off. It can be seen.

<Figure 2>
(1) Upper left: In Comparative Example 1 (release agent: none), an aluminum foil burn-in trace remains. The burn-in trace cannot be removed by washing with water, and the stainless steel plate cannot be reused.
(2) Bottom left: Example (release agent: aqueous solution of synthetic smectite and cerium hydroxide) has no aluminum foil seizure traces, release agent adhesion traces, or imprint traces, and stainless steel plates can be reused It is a state.
(3) Upper right: In Conventional Example 2 (release agent: commercially available boron nitride lubricant), a release trace of the release agent remains. The trace of peeling cannot be removed by washing with water, and the stainless steel plate cannot be reused.
(4) Lower right: In Example 1 (release agent: commercially available molybdenum disulfide lubricant), a trace remains. The stamp marks cannot be removed by washing with water, and the stainless steel plate cannot be reused.

From the results in Table 1, the following was found.
(1) The mold release agent of the example is an aqueous dispersion solution containing only an inorganic substance without containing graphite of a smectite group-swelling layered clay mineral as a main material and a cerium hydroxide inorganic metal adsorbent as an auxiliary material as a solid content. is there. Therefore, the average coating thickness was 36.0 μm and the standard deviation was 2.7 μm, and a coating film (release layer) of a solid part of the release agent could be formed with a uniform thickness. In the heat press test, neither discoloration, ignition, or gas generation was observed, and the cushioning material encapsulated with the aluminum foil surface material and the stainless steel plate were not seized, and both were easily peeled off. Moreover, although the stainless steel plate after the hot press test was observed, there were no press marks or scratches, and it was in a state where it could be reused.

(2) In Comparative Example 1, no release agent is used, and the constituent materials pressed in the hot press test are all inorganic. Therefore, in the hot press test, there was no discoloration, ignition, or gas generation, but a seizure phenomenon occurred between the cushion material encapsulated with the aluminum foil surface material and the stainless steel plate. When both were forcibly peeled off, the aluminum foil adhesion marks remained clearly on the stainless steel plate and could not be removed by washing with water, and the stainless steel plate could not be reused. When the seizure phenomenon occurs, workability and productivity are remarkably lowered, and in the case of a large press-formed product, there is a risk of dropping the upper stainless steel plate, which is a serious problem in terms of safety.

(3) The mold release agent of Comparative Example 2 is a water-dispersed solution made of only inorganic substances without containing only the smectite group-swelling layered clay mineral as a solid content. Therefore, the average coating thickness was 41.5 μm and the standard deviation was 11.5 μm, and the thickness uniformity was greatly reduced as compared with the examples. This is because the mold release agent does not contain the inorganic metal adsorbent (adhesion auxiliary material) as in the examples, so that the wettability with the stainless steel plate is poor and coating unevenness occurs. Also, in the hot press test, there was no discoloration, ignition, or gas generation, but the seizure phenomenon between the cushion material encapsulated with the aluminum foil surface material and the stainless steel plate occurred in part, and both could be easily peeled off. There wasn't. Moreover, adhesion marks remained on the stainless steel plate after the hot press test, and it was impossible to reuse the stainless steel plate.

(4) The mold release agent of Conventional Example 1 is a commercially available dry molybdenum disulfide lubricant. Since the solvent is isopropanol and xylene and there is a risk of ignition or explosion, drying at room temperature rather than heat drying was performed. However, when the weather is bad, it takes time, and it is considered that there is a problem in coating workability. Moreover, since it will have anesthesia if it inhales in large quantities, it is thought that there exists a problem which requires the hot press molding apparatus provided with the mask or suction apparatus which prevents inhalation. The average coating thickness is 4.6 μm and the standard deviation is 3.2 μm. There are variations in thickness, but it adheres to the entire surface of the stainless steel plate, and has high adhesion and the dry coating is strong and difficult to peel off. Met. In the hot press test, there was no ignition, and there was no seizure phenomenon between the cushioning material encapsulated with the aluminum foil surface material and the stainless steel plate, and both could be peeled off. However, a portion of the molybdenum disulfide was discolored, and a portion that changed from dark brown to white gray was seen, and this portion was peeled off when touched, leaving a trace on the stainless steel plate. This imprint could not be removed by washing with water, and the stainless steel plate could not be reused. This white gray component is the one that oxygen in the air reacts with molybdenum disulfide and changes to molybdenum trioxide. Since sulfur gas generated by decomposition may sulfidize nearby metals, Use with caution. Thus, molybdenum disulfide lubricant is considered impractical.

(5) The mold release agent of Conventional Example 2 is a commercially available boron nitride lubricant. Since the solvent was methylene chloride and the ignition point was a flame retardant organic solvent having a temperature of 556 ° C., it could be dried by heating and the coating workability was good. However, methylene chloride has an environmental impact of ozone depletion, and its carcinogenic risk is 2B (possibly carcinogenic to humans) in the IARC evaluation, so there is a concern about toxicity. Mass users are obliged to report the amount purchased, the amount discarded, and the environmental release, which is the difference between them, and the amount released to the atmosphere is required to be reduced. Therefore, it is considered impractical to use a large amount of boron nitride lubricant for industrial use. Although the average coating thickness was 27.2 μm and the standard deviation was 6.3 μm, there was variation in thickness, but it was attached to the entire surface of the stainless steel plate. However, the adhesiveness was weak, and the dried coating film was peeled off with slight contact, and the surroundings were contaminated with white powder of boron nitride. In the hot press test, there was no ignition, and there was no seizure phenomenon between the cushioning material encapsulated with the aluminum foil surface material and the stainless steel plate, and both could be peeled off. However, a substance that appears to be due to the oxidation of the boron nitride lubricant solvent remains as a stamp on the stainless steel plate, which cannot be removed by washing with water, and the stainless steel plate cannot be reused. .

(6) In this example (comparative example, conventional example), as a hot press test, a release agent was attached to the surface of the stainless steel plate to provide a release layer, and then the entire surface of the aluminum foil was coated. The cushioning material is sandwiched between two stainless steel plates so that the release agent adhering surface (release layer) of the stainless steel plate is in contact with the front and back surfaces of the cushioning material placed on the plate, and hot press is performed to evaluate the performance of the release agent. However, apart from this, the mold release agent is not attached to the surface of the stainless steel plate, but is attached to the front and back surfaces of the cushioning material in which the surface material of the aluminum foil is arranged over the entire surface, and then the surface of the aluminum foil is provided. The cushioning material is sandwiched between two stainless steel plates so that the stainless steel plate is in contact with the front and back surfaces (release agent adhering surface, release layer) of the cushion material with the entire surface of the material, and the performance of the release agent is performed by hot pressing. After evaluation, this example (comparison) Was the same result as the conventional example).

Claims (8)

  In the hot press molding performed by interposing a plate-like cushion material with a surface material of a metal sheet between the hot plate of the hot press molding apparatus and the object to be molded, and a backing plate as necessary, A mold release agent for preventing seizure of the hot plate or the contact plate in contact with the metal sheet, a smectite group-swelling layered clay mineral as a main material, cerium hydroxide, cerium oxide as an auxiliary material, Zeolite and an aqueous solution containing an inorganic metal adsorbent selected from Schwertmannite as a solid content, wherein the solid content is substantially free of graphite and consists essentially of an inorganic material. A mold release agent.   The mold release agent according to claim 1, wherein the smectite group-swelling layered clay mineral is a synthetic smectite.   The mold release agent according to claim 1 or 2, wherein the inorganic metal adsorbent is cerium hydroxide.   The aqueous solution contains 0.4 to 4% by weight of the solid content, and the solid content is 75 to 98% by weight of the smectite swellable layered clay mineral and 2 to 25% by weight of the inorganic metal adsorbent. The mold release agent according to any one of claims 1 to 3, characterized by comprising:   A plate-like cushioning material provided with a surface material of a metal sheet, which is interposed between a hot platen of a hot press molding apparatus and a workpiece, and the outer surface of the surface material has A cushioning material, wherein the release agent according to any one of claims 1 and 2 is attached in a film form and dried to form a solid film of the release agent.   It is a hot press molding method that is performed by interposing a plate-like cushion material with a metal sheet surface material between the hot plate of the hot press molding device and the object to be molded, and a backing plate as necessary. Further, the cushion material is the cushion material according to claim 5, wherein the release agent adhering surface is brought into contact with the hot plate and / or the backing plate. .   It is a hot press molding method that is performed by interposing a plate-like cushion material with a metal sheet surface material between the hot plate of the hot press molding device and the object to be molded, and a backing plate as necessary. The release agent according to any one of claims 1 to 4 is attached to the contact surface of the surface material with the heating plate and / or the contact plate in the form of a film. A hot press molding method characterized in that a solid film of is formed.   It is a hot press molding method that is performed by interposing a plate-like cushion material with a metal sheet surface material between the hot plate of the hot press molding device and the object to be molded, and a backing plate as necessary. The release agent according to any one of claims 1 to 4, wherein the release agent according to any one of claims 1 to 4 is attached to the contact surface of the hot plate and / or the contact plate with the surface material, and the release agent. A hot press molding method characterized in that a solid film of is formed.