JP6742941B2 - Cushion material for hot pressing and method for manufacturing cushion material for hot pressing - Google Patents

Description

The present invention relates to a hot-press cushion material and a method for manufacturing the hot-press cushion material.

Generally, in the production of printed wiring, electric components having a laminated structure such as a liquid crystal display board, and laminated materials, decorative boards, building materials having a laminated structure such as laminated wood, for the purpose of press molding or thermocompression bonding of a laminated body, Heat pressing is performed.

For example, a printed wiring board is manufactured by laminating a resin prepreg and a copper foil or the like, and then applying pressure and heat by a hot platen, that is, hot pressing. In the hot press, the prepreg is once heated to lower its viscosity and returns to a liquid state, and then gradually hardened. In such a hot press, it is required that the distribution of pressure and temperature applied to the laminate is uniform.

For this reason, a cushioning material for hot pressing is generally used in hot pressing. The cushioning pad for hot press is arranged between the hot platen and the laminated body, and the pressure and temperature applied from the hot platen are dispersed in the plane direction to make the pressure distribution and the temperature distribution in the hot press uniform. You can Therefore, in order to make pressure distribution and temperature distribution uniform, the cushioning material for hot press has proper deformation followability, cushioning property, thermal conductivity, high durability (eg, heat resistance), etc. as basic performance. It has been demanded.

In Patent Document 1, a cover layer made of unstretched meta-aromatic polyamide fibers or a web containing the fibers is provided on one or all surfaces of a substrate in which all or main fibers are made of meta-aromatic polyamide. A heat-resistant cushion material which is heat-treated at a temperature not lower than the glass transition point of aromatic polyamide fiber is disclosed.
Patent Document 2 discloses a heat-resistant cushion material in which an airtight layer made of heat-resistant fibers is formed on the surface of a main body made of heat-resistant fibers.

Patent Document 3 includes a first non-woven fabric that constitutes an inner layer and a second non-woven fabric that is disposed on both surface sides of the first non-woven fabric and constitutes an outer layer, and the second non-woven fabric is As a constituent material, a copolymer para-aramid fiber having a basis weight of 80 to 400 g/m ² is used, and the first non-woven fabric is more rigid than the copolymer para-aramid fiber as the constituent material. There is disclosed a cushioning pad for hot pressing, in which highly resistant fibers are used, and the heat resistant temperatures of the first nonwoven fabric and the second nonwoven fabric are respectively 270° C. or higher.

JP-A-6-91780 JP-A-8-169074 JP, 2014-37654, A

By the way, in order to smoothly perform the hot pressing step, the hot pressing cushion material is generally required to have good peelability from the hot platen. Furthermore, when the cushioning pad for hot pressing is used, it is necessary to suppress the fluffing of the constituent fiber material and the subsequent detachment (hair removal). When hair loss occurs, the detached fibrous material may be mixed into the laminate and adversely affect the final product.

On the other hand, for the purpose of automating the hot pressing process, a cushioning pad for hot pressing may be automatically loaded. In such automatic loading, the cushioning pad for hot press is sucked and held to lift, convey, and place the cushioning pad for heat press. Here, the hot-press cushion material has tended to be lighter in weight in recent years, and therefore, even in the automatic loading apparatus, there is a tendency to perform suction with a weaker suction force than in the conventional case. Therefore, the hot-press cushioning material is required to have good transportability such that it can be automatically loaded even with a weaker suction force than the conventional one.

Here, the hot-press cushion material having the fiber layer and the non-woven fabric layer as the surface layer as described in Patent Document 1 and Patent Document 3 has sufficient transportability corresponding to such recent tendency of automatic transport. I don't have it. On the other hand, when the airtight layer is provided as described in Patent Document 2, the releasability from the hot platen is not sufficient. As described above, the hot-press cushion materials described in Patent Documents 1 to 3 described above do not simultaneously satisfy the above-described performance.
Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to have excellent transportability in automatic loading, excellent releasability from a heating plate, and fluffing during use is suppressed. It is to provide a new and improved cushioning material for hot pressing and a method for manufacturing a cushioning material for hot pressing.

In order to solve the above problems, according to an aspect of the present invention, a base material, a batt fiber layer disposed on a first main surface of the base material, and having an outer surface softened and smoothed, and the base material. And an airtight sheet layer disposed on the second main surface side of the above.

The batt fiber layer may include batt fibers, and may be softened and smoothed at a temperature equal to or higher than the glass transition temperature of the batt fibers.

In order to solve the above problems, according to another aspect of the present invention, a base material, a batt fiber layer disposed on a first main surface of the base material, and a second main surface of the base material. An airtight sheet layer arranged on the surface side, and the outer surface of the batt fiber layer is composed of at least a portion of a fiber having a flat shape along the outer surface, a cushioning pad for hot press, Provided.

The airtight sheet layer may be composed of a fiber sheet or a resin film.
The surface roughness Ra of the outer surface of the batt fiber layer may be 2.5 to 11 μm.
The air permeability according to the Frazier-type method specified in JIS L 1096 may be 0.2 cm ³ /cm ² /sec or less.

The batt fiber layer may include unstretched meta-aromatic polyamide fiber.
The batt fiber constituting the batt fiber layer may have a fineness of 0.8 to 11 dtex.
The hot-press cushion material may further include a batt fiber layer disposed between the base material and the airtight sheet layer.
The substrate may include aromatic polyamide fibers.

Further, in order to solve the above problems, according to another aspect of the present invention, the batt fibers are arranged on at least one main surface of the base material to perform needling, and at least one main surface of the base material is provided. A step of forming a batt fiber layer to obtain a laminate,
A cushion material for hot-pressing, comprising: a step of performing a pressing at a temperature not lower than the glass transition temperature of the bat fiber in a state where an airtight sheet is arranged on the other main surface side of the base material in the laminate. A method is provided.

As described above, according to the present invention, a new and improved hot-press cushion material and hot-press cushion having excellent transportability in automatic loading, excellent peelability from a hot platen, and suppressed fuzzing during use. A method for manufacturing a material can be provided.

It is a schematic diagram which shows an example of the use condition of the cushion material for hot presses which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the use condition of the cushion material for hot presses which concerns on one Embodiment of this invention. It is sectional drawing of the cushioning material for hot presses which concerns on one Embodiment of this invention. It is sectional drawing of the cushion material for hot presses which concerns on the modification of this invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 are schematic views showing an example of a usage state of a cushioning pad for hot pressing according to an embodiment of the present invention, and FIG. 3 is a sectional view of the cushioning pad for hot pressing according to an embodiment of the present invention. Is. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, and duplicate description will be omitted. Further, the members in each drawing are appropriately emphasized for ease of explanation, and the dimensions in the drawings do not show actual dimensions.

<1. Heat press>
First, prior to the description of the hot-press cushion material, an example of the hot-press using the hot-press cushion material according to the embodiment of the present invention will be described. In addition, in this embodiment, it is assumed that the object to be hot-pressed is the laminated board 300 as a precursor of the printed wiring board.

As shown in FIG. 1, the hot pressing is performed by pressing the laminated plate 300 with a pair of heated heating plates 100 that are heated. Further, as shown in FIG. 1, hot pressing can be performed on a plurality of laminated plates 300 at the same time.

As shown in FIG. 2, in the laminated board 300, metal foils 302 such as copper foils are arranged on both surfaces of a prepreg 301. The prepreg 301 is configured by stacking a plurality of plate materials in which glass cloth is impregnated with a curable resin and is in a semi-cured state.

A mirror surface plate 200 such as a stainless plate is arranged between the plurality of laminated plates 300 so as not to come into direct contact with each other and for surface molding. In addition, in order to avoid direct contact with the hot-press cushion material 1 and the hot platen 100 as well as above the laminated plate 300 existing at the upper end and below the laminated plate 300 existing at the lower end, the surface is formed. Therefore, the mirror plate 200 is arranged.

The object to be pressed, in which the laminated plate 300 and the mirror surface plate 200 are laminated, is pressed by the hot platen 100 via the cushioning materials 1 for hot pressing arranged above and below the pressed object. Here, the hot-press cushion material 1 has appropriate thermal conductivity, deformation followability, and cushioning property, and the pressure and heat from the hot platen 100 are evenly laminated on the laminated plate 300 and the mirror surface plate 200 to be pressed. It has the function of transmitting it to the object.

The conventional hot-press cushion material has problems in transportability in automatic loading, releasability from a heating plate, and fluffing during use, but in the hot-press cushion material 1 according to the present embodiment, As shown, these problems are prevented.

<2. Cushion material for heat press>
Next, the cushioning pad for hot pressing according to this embodiment will be described.

The hot-press cushion material 1 shown in FIG. 3 is used, for example, for manufacturing an electric component having a laminated structure such as a printed wiring board, and more specifically for a molding press. The hot-press cushion material 1 includes a base material 10, a first batt fiber layer 20 arranged on one main surface (first main surface) of the base material 10, and the other main surface of the base material 10 ( The second batt fiber layer 30 is disposed on the second main surface), and the airtight sheet layer 40 is disposed on the surface of the second batt fiber layer 30 opposite to the base material 10 side.

The base material 10 is a main component of the hot-press cushion material 1, and is a layer for exhibiting basic performance as the hot-press cushion material 1, such as thermal conductivity, deformation followability, and cushioning property. The base material 10 has a base cloth 12 and a felt layer 14.

The base fabric 12 is a fiber-reinforced base material that contributes to maintaining the tensile strength and stabilizing the shape of the hot-press cushion material 1. The base cloth 12 is not particularly limited, but can be made of, for example, a woven cloth or a lattice material. When the base fabric 12 is a woven fabric, the structure of the woven fabric is not particularly limited, and any of plain weave, twill weave, satin weave, or multiple weave using these can be used. As the lattice material, for example, a material in which warp yarns and weft yarns are overlapped can be used. As the constituent material of the base cloth 12, for example, meta-aromatic polyamide, para-aromatic polyamide, wholly aromatic polyester fiber, polyparaphenylene benzobisoxazole (PBO) fiber, stainless fiber and the like can be appropriately adopted. Is. The base fabric 12 may be omitted as appropriate according to the specifications of the hot-press cushion material 1.

The felt layers 14 are arranged on both sides of the base fabric 12. The felt layer 14 is a fiber assembly layer formed by intertwining short fibers, and is basically used as the hot-press cushion material 1 such as thermal conductivity, deformation followability, and cushioning property in the hot-press cushion material 1. Exhibits the desired performance.

The felt layer 14 is formed, for example, by arranging a fibrous web made of batt fibers as short fibers on the base fabric 12, entangled with each other by needle punching, and entangled with the base fabric 12.

The material forming the felt layer 14 is not particularly limited, but it is preferable that the felt layer 14 is formed of a heat-resistant resin material, for example, an aromatic polyamide. For example, a meta-aromatic polyamide and/or a para-aromatic polyamide is used. Can be used. Specifically, as the batt fiber, a staple fiber composed of the above materials can be used. That is, the felt layer 14 of the base material 10 preferably contains aromatic polyamide fibers. More specifically, meta-aromatic polyamide fibers mainly composed of polymetaphenylene isophthalamide (conex (trade name/made by Teijin) or Nomex (trade name/made by Dupont)), polyparaphenylene terephthalamide, etc. Para-aromatic polyamide fibers (Kevlar (trade name/Dupont) and Technora (trade name/Teijin)), PPS fibers (torquer (trade name/Toray)), etc., which are the main components, or a combination of two or more thereof. Can be used.

The fiber length of the short fibers constituting the felt layer 14 is not particularly limited, but may be, for example, 38 to 130 mm. The fineness of the short fibers constituting the felt layer 14 is not particularly limited, but may be 0.8 to 11 dtex, for example.

The basis weight of the felt layer 14 can be selected according to the application of the hot-press cushion material 1, and is not particularly limited, but for example, the total of each layer on both sides of the base fabric 12 is 300 to 2700 g/m ² , preferably Is 1000 to 2200 g/m ² . This makes it possible to obtain appropriate heat conductivity and deformation followability.

The first batt fiber layer 20 is arranged on one main surface of the base material 10 and constitutes a surface layer of the hot-press cushion material 1. In addition, the first batt fiber layer 20 is arranged on the side that normally contacts the hot platen when the hot-press cushion material 1 is used.

The first batt fiber layer 20 is formed by entangling batt fibers by needle punching and softening and smoothing the outer surface of the formed batt fiber layer. As a result, the outer surface 21 of the first batt fiber layer 20 is composed of at least a portion of the fiber having a flat shape along the outer surface 21.

Such softening and smoothing can be performed by treating the batt fibers constituting the first batt fiber layer 20 at a temperature equal to or higher than the glass transition temperature. In softening and smoothing, it is preferable to press the outer surface 21 of the first batt fiber layer 20 with a hot platen or the like while maintaining the above temperature.

By softening and smoothing the outer surface 21 in this way, the batt fibers in the vicinity of the outer surface 21 are in close contact with each other and self-adhere, or are inserted into a space formed by another fiber and adhered. This prevents fuzzing of the batt fibers on the outer surface 21. Consequently, hair loss from the first batt fiber layer 20 is prevented.

Further, the outer surface 21 of the first batt fiber layer 20 is softened and smoothed to be appropriately densified, and the air permeability of the hot-press cushion material 1 is reduced. Thereby, the air permeability of the hot-press cushion material 1 becomes sufficiently low together with the airtight sheet layer 40 described later, and the transportability in the automatic loading of the hot-press cushion material 1 is improved. Further, since the outer surface 21 is densified, it is also possible to suck and hold the hot-press cushion material 1 from the side of the first batt fiber layer 20 by the suction device of the automatic stacking device and carry it. ..

On the other hand, the outer surface 21 of the first batt fiber layer 20 has an appropriate surface roughness because it is made of batt fibers, even though it is smoothed, The peelability between 20 and the hot platen is excellent. Therefore, the hot-press cushion material 1 is excellent in peelability from the hot platen.

The surface roughness Ra of the outer surface 21 of the first batt fiber layer 20 is not particularly limited, but is, for example, 2.5 to 11 μm, preferably 3 to 8 μm, and more preferably 4 to 7 μm. When the surface roughness Ra of the outer surface 21 of the first batt fiber layer 20 is equal to or more than the lower limit value, the releasability of the hot-press cushion material 1 from the hot platen can be further improved. Further, when the surface roughness Ra of the outer surface 21 of the first batt fiber layer 20 is not more than the above upper limit value, the transportability in the automatic loading of the hot-press cushion material 1 can be further improved. .. In addition, in this specification, surface roughness Ra can be measured based on JIS-B0633.

Further, as described above, at least a part of the outer surface 21 of the first batt fiber layer 20 is composed of the batt fiber having a flat shape along the outer surface 21.
Here, the degree of the flat shape of the batt fibers can be defined by the aspect ratio of the cross section of the batt fibers forming the outer surface 21. Specifically, the aspect ratio of the batt fibers when observing the cross section in the thickness direction of the first batt fiber layer 20 (diameter in the plane direction of the cushion material 1 for hot press/thickness of the cushion material 1 for hot press) Direction diameter).
The aspect ratio is not particularly limited, but is, for example, 1.2 to 3.0, preferably 1.5 to 2.5.

The batt fibers constituting the first batt fiber layer 20 are not particularly limited as long as they can be softened and smoothed as described above, but for example, unstretched fibers, preferably unstretched aromatic polyamide fibers, and more preferably Unstretched meta-aromatic polyamide fibers can be used. Such unstretched fibers are relatively easily deformed by the softening/smoothing treatment as compared with the fibers subjected to the stretching treatment, and are advantageous in forming the outer surface 21 as described above.
As the batt fiber, in addition to the undrawn fiber described above, a fiber that has been subjected to a drawing treatment may be used. Examples of such fibers include various fibers that can be used for the felt layer 14 described above. In this case, the weight ratio of the unstretched fibers in the first batt fiber layer 20 is, for example, 70% by mass or more, preferably 80% by mass or more, and more preferably 100% by mass.

The fineness (average) of the batt fibers constituting the first batt fiber layer 20 is not particularly limited, but is, for example, 0.8 to 11 dtex, preferably 2 to 6 dtex. When the fineness of the batt fiber is at least the above lower limit value, the outer surface 21 after the softening/smoothing treatment can be further smoothed. On the other hand, when the fineness of the batt fibers is equal to or less than the above upper limit value, the number of fibers can be increased and the outer surface 21 can be made dense.

The basis weight of the first batt fiber layer 20 is not particularly limited, but is, for example, 80 to 200 g/m ² , preferably 100 to 150 g/m ² . When the basis weight of the first batt fiber layer 20 is less than or equal to the lower limit value, the first batt fiber layer 20 is easily affected by the surface shape of the base material 10, depending on the material configuration of the hot-press cushion material 1. As a result, the surface smoothness of the first batt fiber layer 20 may decrease. On the other hand, when the basis weight of the first batt fiber layer 20 exceeds the upper limit value, the first batt fiber layer 20 hardly contributes to the cushioning property. The cushioning property may be reduced as compared with the case where the first batt fiber layer 20 is not provided.

As shown in FIG. 2, the hot-press cushion material 1 is normally arranged on the hot platen 100 side such that the outer surface 21 of the first batt fiber layer 20 faces the hot platen 100. Thereby, the releasability between the hot platen 100 and the hot-press cushion material 1 can be made excellent.

The second batt fiber layer 30 is arranged on the main surface of the base material 10 opposite to the first batt fiber layer 20 side. The second batt fiber layer 30 is formed by entangling batt fibers by needle punching.

The batt fibers constituting the second batt fiber layer 30 are not particularly limited, but the unstretched fibers described above and various fibers that can be used for the felt layer 14 described above can be used. Among them, when the second batt fiber layer 30 contains unstretched fibers as batt fibers, preferably unstretched aromatic polyamide fibers, more preferably unstretched meta-aromatic polyamide fibers, adhesion of the airtight sheet layer described later Sex becomes even higher.

The fineness (average) of the batt fibers forming the second batt fiber layer 30 is not particularly limited, but is, for example, 0.8 to 11 dtex, preferably 2 to 6 dtex.

The basis weight of the second batt fiber layer 30 is not particularly limited, but is, for example, 80 to 200 g/m ² , and preferably 100 to 150 g/m ² .

One of the reasons for disposing the second batt fiber layer 30 is to prevent the occurrence of warpage during repeated use of the hot-press cushion material 1. That is, in the hot-press cushion material 1, a difference in shrinkage occurs between the first batt fiber layer 20 side and the second batt fiber layer 30 side of the hot-press cushion material 1 due to heat of repeated press molding during use. Warpage may occur in the hot-press cushion material 1. From the viewpoint of preventing the warp of the hot-press cushion material 1, the second batt fiber layer 30 preferably has the same configuration as the first batt fiber layer 20.

The airtight sheet layer 40 is arranged on the surface of the second batt fiber layer 30 opposite to the base material 10 side. By forming the airtight sheet layer 40 from a fiber sheet or a resin film, the airtight sheet layer 40 adheres to the second batt fiber layer 30 and maintains high airtightness, which contributes to lowering the air permeability of the hot-press cushion material 1. To do. Therefore, in combination with the airtightness of the outer surface 21 of the first batt fiber layer 20 described above, the hot-press cushion material 1 is sucked and held by the suction device even with a relatively weak suction force during automatic loading. To be done. That is, the hot-press cushion material 1 has excellent transportability during automatic loading.

The airtight sheet layer 40 is formed by thermocompression-bonding or heat-sealing a fiber sheet or a resin film to the second batt fiber layer 30. The fibrous sheet may be, for example, a paper-like sheet made by paper making, that is, a wet non-woven fabric. Further, the material of the fibers constituting the fiber sheet is not particularly limited, but it is preferable to be composed of a resin material having heat resistance, for example, aromatic polyamide, for example, meta-aromatic polyamide and/or para-aromatic. Group polyamides can be used. The resin film is not particularly limited, but is, for example, a fluorine-based resin film, specifically, ethylene/tetrafluoroethylene copolymer, tetrafluoroethylene/hexafluoropropylene copolymer, polytetrafluoroethylene, polyfluoride. Vinylidene fluoride, polyvinyl fluoride, perfluoroalkoxy fluororesin and the like can be used.

The surface roughness Ra of the airtight sheet layer 40 is not particularly limited, but is, for example, 2 to 7 μm, preferably 4 to 6 μm. Accordingly, in the automatic stacking device, when the outer surface 41 of the fiber sheet layer 40 is sucked by the suction device as the suction surface, the vacuum state between the suction device and the outer surface 41 can be favorably maintained.

The basis weight of the airtight sheet layer 40 is not particularly limited, for example, 40 and 80 g / ^{m 2,} preferably 50 to 70 g / ^{m 2.}
The thickness of the airtight sheet layer 40 is not particularly limited, but is, for example, 25 to 200 μm, preferably 50 to 100 μm.

The air permeability of the hot-press cushion material 1 having the above-mentioned configuration according to the Frazier method defined in JIS L 1096 is not particularly limited, but is, for example, 1.0 cm ³ /cm ² /sec or less, preferably 0.2 cm ³ /Cm ² /sec or less, more preferably 0.0 cm ³ /cm ² /sec. This makes it possible to further improve the transportability in the automatic loading of the hot-press cushion material 1. The lower limit of the air permeability is not particularly limited, but may be 0 cm ³ /cm ² /sec, for example. When the cushioning pad for hot press has an air permeability of 0.3 cm ³ /cm ² /sec or more, a problem may occur in automatic transportation depending on the configuration of the automatic loading machine used.

The density of the hot-press cushion material 1 is not particularly limited, but is, for example, 0.3 to 0.7 g/cm ³ , preferably 0.4 to 0.6 g/cm ³ . As a result, the thermal conductivity of the hot-press cushioning material 1 during the hot pressing is stable (the variation of the thermal conductivity change is small) and the excellent cushioning property is maintained from the initial use to the final use.

The thickness of the hot-press cushion material 1 is not particularly limited, but is, for example, 1 to 8 mm, preferably 2 to 6 mm.
The dimensions of the hot-press cushion material 1 are not particularly limited and can be appropriately set depending on the application and the hot platen used. For example, each length in the longitudinal direction and the width direction is 3.6×1.3 m. Can be

In the above-described hot-press cushion material 1, since the outer surface of the first batt fiber layer 20 is softened and smoothed, fuzz of the batt fiber on the outer surface 21 is prevented. On the other hand, since the first batt fiber layer 20 is composed of batt fibers, the hot-press cushion material 1 has excellent releasability from the hot platen.

Furthermore, since the hot-press cushion material 1 has the airtight sheet layer 40, the air-permeability of the hot-press cushion material 1 is low, and the airtightness of the outer surface 21 of the first batt fiber layer 20 is low. Together with this, the hot-press cushion material 1 is sucked and held by the suction device even when the suction force is relatively weak during automatic loading. That is, the hot-press cushion material 1 has excellent transportability during automatic loading. Further, the hot-press cushion material 1 has excellent transportability not only from the outer surface 41 side but also from the outer surface 21 side for automatic transport by suction. In particular, in recent years, the cushioning material for hot press generally tends to be lighter in weight, and therefore, even in the automatic loading apparatus, there is a tendency to perform suction with a weaker suction force than in the conventional case. For example, Patent Document 1 discloses that suction is performed under the condition of 500 mmH ₂ O, but at present, suction is performed at a vacuum degree of, for example, about 50 to 100 inches of water column. Further, depending on the suction device, suction is stopped after reaching a predetermined degree of vacuum. Even in such a case, the hot-press cushion material 1 can be easily sucked and held by the suction device of the automatic stacking device.

As described above, the hot-press cushion material 1 is used, for example, for manufacturing an electric component (laminated product) having a laminated structure such as a printed wiring board, and more specifically for a molding press. For example, an example of a laminated product is as follows. There are various kinds of laminated products other than the examples shown below.

(1) Laminate that serves as a substrate for a printed wiring board:
Examples of the laminated plate include a paper phenol laminated plate made of kraft paper and phenol resin, a glass epoxy laminated plate made of woven glass fiber and epoxy resin, and the like.
(2) Printed wiring board:
As this printed wiring board, a single-sided printed wiring board with a conductor pattern formed on one side of the board, a double-sided printed wiring board with conductor patterns formed on both sides of the board, and a conductor pattern formed not only on the outer surface of the board but also inside Examples of the multilayer printed wiring board include:
(3) Flat panel display:
Examples of flat panel displays include liquid crystal displays and electroluminescence.
(4) Semiconductor package:
As the semiconductor package, for example, a chip size package (Chip Size Package (CSP)) having almost the same size as the chip can be cited.

The cushioning pad for hot pressing according to the present invention can be used not only for the above-mentioned applications but also for producing a building material having a laminated structure such as a laminated material, a decorative board, and a laminated material. In this case, the cushioning pad for hot pressing according to the present invention can be appropriately modified in structure depending on the application.

<3. Manufacturing method of cushion material for hot press>
Next, a method for manufacturing the cushioning pad for hot pressing according to the present invention will be described by taking the method for manufacturing the cushioning pad 1 for hot pressing described above as an example.

The method for manufacturing a hot-press cushioning material according to the present invention, the batt fibers are arranged on at least one main surface of the base material to perform needling, and a batt fiber layer is formed on at least one main surface of the base material. A step of obtaining a laminate, and a step of pressing at a temperature equal to or higher than the glass transition temperature of the bat fiber in a state where an airtight sheet is arranged on the other main surface side of the base material in the laminate. ..

In this embodiment, first, the base material 10 is prepared prior to the step of obtaining the above-mentioned laminated body. The base material 10 is a felt layer formed by arranging a fibrous web made of batt fibers as short fibers on the base cloth 12 on the base cloth 12 and intertwining them with each other by needle punching as well as entangling with the base cloth 12. 14 can be obtained by forming.

In the next step, batt fibers are arranged on both surfaces of the base material 10 and needling is performed to form batt fiber layers 20 and 30 on both surfaces of the base material 10 to obtain a laminate. Specifically, the batt fibers are arranged on one main surface of the base material 10 to perform needling, and then the batt fibers are arranged on the other main surface of the base material 10 to perform needling. The first batt fiber layer 20 and the second batt fiber layer 30 are obtained. Either the first batt fiber layer 20 or the second batt fiber layer 30 may be formed first.

In the next step, with respect to the obtained laminate, the first batt fiber layer 20 is provided with the airtight sheet on the main surface on the opposite side, that is, the second batt fiber layer 30. Pressing is performed at a temperature not lower than the glass transition temperature of the batt fibers constituting the batt fiber layer 20. Thereby, the airtight sheet is brought into close contact with the second fiber layer 30 to form the airtight sheet layer 40, and the outer surface 21 of the first batt fiber layer 20 is softened and smoothed.

The pressing temperature is not particularly limited as long as it is the glass transition temperature of the batt fibers constituting the first batt fiber layer 20 or more, but is preferably the glass transition temperature of the batt fibers constituting the first batt fiber layer 20 or more. It is below the decomposition temperature or the melting temperature. Specifically, the pressing temperature is, for example, 270 to 330°C, preferably 280 to 300°C.

The pressing pressure is not particularly limited, from the viewpoint of thermal conductivity of stability and cushioning sustained during use of the hot-press cushion material 1, for example 5~40kg / cm ^2, preferably 10-20 kg / cm ² is there.
The pressing time is not particularly limited and can be appropriately set, but is, for example, 10 to 40 minutes, preferably 15 to 25 minutes.

Through the above steps, the hot-press cushion material 1 can be obtained. The obtained hot-press cushion material 1 may be appropriately cut according to the application, or may be subjected to post-treatment such as washing.

<4. Modification>
Next, a modified example of the above-described hot-press cushion material 1 will be described. FIG. 4 is a cross-sectional view of a hot-press cushion material according to a modification of the present invention. In the hot-press cushion material 1A shown in FIG. 4, the second batt fiber layer 30 is omitted, and the airtight sheet layer 40 is directly arranged on the main surface of the base material 10 opposite to the first batt fiber layer 20 side. This is different from the hot press cushion material 1.

Also in this modification, since the hot-press cushion material 1A includes the first batt fiber layer 20 as described above, fluffing of the batt fibers is prevented and the hot platen is excellent in peelability. Since the hot-press cushion material 1 includes the airtight sheet layer 40, the hot-press cushion material 1 has excellent airtightness on the outer surface 21 of the first batt fiber layer 20 and is excellent in transportability during automatic loading.

Note that, as described above, the second batt fiber layer 30 is arranged mainly for suppressing warpage during use of the hot-press cushion material 1. Therefore, the hot-press cushion material 1A is suitable when the occurrence of warpage is not a problem, or when the second batt fiber layer has a structure in which warpage is suppressed by the material configuration of each layer even if the second batt fiber layer is omitted. There is.

The hot-press cushion material 1A can be manufactured in the same manner as the hot-press cushion material 1 except that the formation of the second batt fiber layer 30 is omitted in the step of obtaining the above-mentioned laminated body. That is, at the time of pressing, the airtight sheet is arranged on the main surface of the laminated body opposite to the first batt fiber layer 20. In this case, in order to strengthen the bond between the base material 10 and the airtight sheet layer 40, an adhesive may be placed between the base material 10 and the airtight sheet layer 40 to bond them together.

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.

<1. Manufacture of cushion materials for hot press>
(1) Preparation of Base Material First, as a base cloth of the base material, a woven cloth in which warp threads and weft threads are made of a meta-aromatic polyamide fiber (m-aramid fiber) (yarn fineness: 2/20S (2 yarns of 20 count spun yarn). Twist), texture: 1/1 plain weave, and basis weight: 100 g/m ² ) were prepared. Then, m-aramid fibers (fineness: 2.2 dtex, fiber length: 51 mm) were laminated at a total basis weight of 900 g/m ² on both sides to produce a base material having a felt layer on both sides of the woven fabric.

(2) Formation of Bat Fiber Layer Next, as the batt fibers of the first and second batt fiber layers, unstretched m-aramid fibers having the fineness shown in Table 1 (fiber length: 51 mm, glass transition temperature: 270° C.) To prepare a first and a second batt fiber layers having a basis weight of 150 g/m ² per side on both sides of the base material, and obtaining a laminate having the first and second batt fiber layers on both sides. It was In addition, in Example 5, the second batt fiber layer was not formed.
The formation of the first and second batt fiber layers is carried out by arranging the above batt fibers as a prebat fiber layer on a base material and performing needling to integrate the base material and the prebat fiber layer. It was

(3) Press Next, pressing is performed in a state where aramid paper (m-aramid paper, thickness: 178 μm) is arranged on the second batt fiber layer to form an airtight sheet layer on the second batt fiber layer. Aramid paper was adhered and the outer surface of the first batt fiber layer was softened and smoothed. The press conditions were as shown in Table 1. In Example 5, instead of the aramid paper, an ethylene/tetrafluoroethylene copolymer film (ETFE film, thickness: 50 μm) was formed on the surface of the base material opposite to the first batt fiber layer. Placed and pressed. Further, in Comparative Example 1, pressing was performed without disposing the aramid paper on the second batt fiber layer. In Comparative Example 3, aramid paper was placed on both sides of the laminate and pressed. As described above, hot-press cushion materials according to Examples 1 to 5 and Comparative Examples 1 to 3 were obtained.

<2. Evaluation>
(1) Surface Roughness Regarding the cushioning material for hot press of each example and each comparative example, the surface roughness profile measuring device (Surfcom 480A: manufactured by Tokyo Seimitsu Co., Ltd.) was used, and the first The surface roughness Ra of the outer surface of the batt fiber layer was measured. The results are shown in Table 1. In the table, the surface roughness of the airtight sheet provided on the first batt fiber layer is shown for the hot-press cushion material according to Comparative Example 3.

(2) Air permeability With respect to the cushioning material for hot press of each example and each comparative example, using a gas permeability meter (Fragile Permeameter: manufactured by Toyo Seimitsu Co., Ltd.), aeration was performed by the Frazier type method specified in JIS L 1096. The degree was measured. In the measurement of air permeability, the suction surface was the first batt fiber layer side. The results are shown in Table 1. Numerical values in parentheses in the table are the actually measured air permeability, and numerical values without parentheses are the numerical values in which the actually measured air permeability is displayed by the display method specified in JIS L 1096. Is.

(3) Aspect Ratio of Bat Fibers The cross section of the outer surface of the first batt fiber layer is observed by a scanning electron microscope, and the aspect ratio of the batt fibers constituting the outer surface of the first batt fiber layer (cushion for hot press is used. The diameter in the plane direction of the material/the diameter in the thickness direction of the cushioning pad for hot press) was measured. The results are shown in Table 1.

(4) Fluffing About the cushioning material for hot press of each Example and each comparative example, the short fibers protruding from the surface of the first batt fiber layer using a microscope (Digital Microscope VHX-900: manufactured by Keyence Corporation). Was observed. At this time, from the surface of the first batt fiber layer, the one in which the short fibers are projected with a length of 0.5 mm or more, or the one in which the short fibers are projected in a loop shape is evaluated as “x”, and other than that. The item was evaluated as “◯”. The results are shown in Table 1.

(5) Peelability Regarding the cushioning material for hot press of each Example and each comparative example, it has an upper heating plate having a stainless steel plate (SUS plate) attached to the upper heating plate and a lower heating plate. In a hot platen press apparatus that is pressed by vertical movement, the hot press cushion material is arranged between the SUS plate and the lower hot platen so that the surface of the first batt fiber layer of the hot press cushion material contacts the SUS plate. Then, hot plate pressing was performed (press condition: 220° C.-40 kg/cm ² -60 minutes), and then the press was released. At this time, the time until each cushion material spontaneously peeled off from the SUS plate was measured, and those having a time of 3 seconds or less were evaluated as “◯”, and those exceeding 3 seconds were evaluated as “x”. The results are shown in Table 1.

(6) Transportability The hot-press cushion materials of Examples and Comparative Examples were sampled at a diameter of 100 mm, and a silicone rubber sucker having a diameter of 50 mm was centered on the surface of the first bat fiber layer of each hot-press cushion material. Was adsorbed. Next, each hot-press cushion material was lifted up through a suction cup. At this time, the lifted cushion material for hot press was evaluated as “◯”, and the one that was not lifted was evaluated as “x”. The results are shown in Table 1.

As shown in Table 1, the hot-press cushion materials according to Examples 1 to 5 were excellent in peelability and transportability while suppressing fuzzing of the batt fiber layer. On the other hand, the hot-press cushioning material according to Comparative Example 1 did not have the airtight sheet layer, and thus was not sufficiently transportable. Further, as for the hot-press cushion material according to Comparative Example 2, the press treatment was performed at a temperature lower than the glass transition temperature of the batt fiber, and as a result, the softening and smoothing treatment was not sufficiently performed. For this reason, the hot-press cushion material according to Comparative Example 2 could not suppress the fluffing of the batt fibers, and also had a large air permeability, resulting in poor transportability.

Further, in the hot-press cushion material according to Comparative Example 3, as a result of disposing the airtight sheet layer on the first batt fiber layer, the outer surface of the first batt fiber layer is not softened and smoothed, and No batt fiber layer was exposed on the outer surface. As a result, the cushioning pad for hot pressing according to Comparative Example 3 could not have appropriate outer surface irregularities derived from the first batt fiber layer, and was inferior in peelability.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to these examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

1, 1A Cushion material for hot pressing 10 Base material 12 Base cloth 14 Felt layer 20 First batt fiber layer 21 Outer surface 30 Second batt fiber layer 40, 40A Airtight sheet layer 41 Outer surface 100 Hot plate 200 Mirror plate 300 Laminated board 301 Prepreg 302 Metal foil

Claims (11)

Base material,
A batt fiber layer disposed on the first main surface of the base material, the outer surface of which is softened and smoothed;
A cushion material for hot pressing, comprising: an airtight sheet layer arranged on the second main surface side of the base material. The cushioning pad for hot pressing according to claim 1, wherein the batt fiber layer contains batt fibers and is softened and smoothed at a temperature equal to or higher than the glass transition temperature of the batt fibers. Base material,
A batt fiber layer disposed on the first main surface of the substrate,
An airtight sheet layer arranged on the second main surface side of the base material,
A cushioning material for hot pressing, wherein at least a part of the outer surface of the batt fiber layer is made of a fiber having a flat shape along the outer surface. The cushion material for hot press according to any one of claims 1 to 3, wherein the airtight sheet layer is composed of a fiber sheet or a resin film. The hot-press cushion material according to any one of claims 1 to 4, wherein the outer surface of the batt fiber layer has a surface roughness Ra of 2.5 to 11 µm. The cushioning material for hot press according to any one of claims 1 to 5, which has an air permeability of 0.2 cm ³ /cm ² /sec or less according to the Frazier type method specified in JIS L 1096. The cushion material for hot press according to any one of claims 1 to 6, wherein the batt fiber layer contains unstretched meta-aromatic polyamide fiber. The hot press cushioning material according to any one of claims 1 to 7, wherein the batt fibers constituting the batt fiber layer have a fineness of 0.8 to 11 dtex. The cushioning pad for hot press according to claim 1, further comprising a batt fiber layer arranged between the base material and the airtight sheet layer. The hot press cushion material according to any one of claims 1 to 9, wherein the base material includes an aromatic polyamide fiber. Performing needling by disposing batt fibers on at least one main surface of the base material, forming a batt fiber layer on at least one main surface of the base material, and obtaining a laminate,
A cushion material for hot-pressing, comprising: a step of performing a pressing at a temperature not lower than the glass transition temperature of the bat fiber in a state where an airtight sheet is arranged on the other main surface side of the base material in the laminate. Method.

Images