JP2023146656A - Resin foam sheet and resin composite body manufacturing method - Google Patents

Abstract

To provide a resin foam sheet which facilitates manufacture of a resin composite body having a three-dimensional shape.SOLUTION: A resin foam sheet is used as a core material of a resin composite body in which a core material composed of a resin foam sheet, and a fiber-reinforced resin layer composed of a sheet-like fiber-reinforced resin material containing a resin and fibers are stacked, wherein 50% or more of volume increase is enabled by secondary foaming by heating at 130°C, a slit line is provided on at least one surface, and a plurality of regions partitioned by the slit line is formed thereon.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a resin foam sheet and a resin composite, and more specifically, to a resin foam sheet used to constitute a core material of a resin composite, and a resin composite using such a resin foam sheet. and a manufacturing method.

Conventionally, fiber-reinforced resin materials called FRP and the like have been widely used because they have both excellent lightness and strength. In recent years, the use of resin composites in which a surface material including a fiber-reinforced resin layer is laminated on a resin foam core material has been expanding. This type of resin composite exhibits excellent lightness by having a resin foam as a core material. Furthermore, since the fiber-reinforced resin layer is made of a fiber-reinforced resin material containing fibers and resin, a resin composite including the fiber-reinforced resin layer as a surface material is also excellent in terms of strength. As the core material of this type of resin composite, in addition to three-dimensional molded products such as bead foam molded products, flat molded products such as resin foam sheets are used. In addition, when a resin foam sheet is used as the core material, a three-dimensional resin composite is produced by hot-pressing a sheet-like laminate of the resin foam sheet and fiber-reinforced resin material with a mold. (See Patent Document 1 (FIG. 7, etc.)).

JP2014-208417A

When bending a laminate using a hot press to form a three-dimensional resin composite, if the resin foam sheet remains cold, buckling or cracking may occur at unintended locations. Such a problem can be solved by performing preheating, as is done before the forming process in a production line for sheet molded bodies. However, in that case, a device equivalent to a preheating furnace in the sheet molded product production line is required, resulting in a large-scale equipment.

For example, a cut line is provided on the resin foam sheet constituting the laminate in a manner that separates the outer surface during bending, and the cut line is provided at a location where bending is planned. By providing this, the resin foam sheet can be easily bent even at room temperature, and unintentional buckling and cracking can be prevented. However, in that case, the cut line widens on the outer surface during bending, resulting in a V-groove-like gap being formed. In this case, even if this outer surface is covered with a fiber-reinforced resin material, dents may appear on the surface of the resin composite. Moreover, in that case, as a result of the resin of the fiber-reinforced resin material flowing into the gap, there is a possibility that voids may be generated in the fiber-reinforced resin layer or fibers may be exposed due to resin breakage.

For the reasons described above, it is difficult to easily manufacture a three-dimensional resin composite whose core material is a resin foam sheet. Therefore, an object of the present invention is to provide a resin foam sheet that can easily produce a resin composite having a three-dimensional shape, and also to provide a method for manufacturing a resin composite that can produce a resin composite in a simple manner. It is said that

In order to solve the above problems, the inventors of the present invention have conducted intensive studies and found that if the resin foam sheet has high secondary foaming properties, the V-groove gap can be narrowed by increasing the volume due to secondary foaming when molding a resin composite. The present invention was completed based on the discovery that it is possible to suppress the appearance of depressions and voids on the surface of a resin composite.

The present invention aims to solve the above problems.
A core material made of resin foam sheet,
A resin foam sheet used to constitute the core material of a resin composite in which a fiber-reinforced resin layer made of a sheet-like fiber-reinforced resin material containing resin and fibers is laminated,
It is possible to increase the volume by more than 50% through secondary foaming by heating at 130℃.
To provide a resin foam sheet in which at least one surface is provided with score lines and a plurality of regions divided by the score lines are formed.

The present invention aims to solve the above problems.
A core material made of resin foam sheet,
A method for producing a resin composite in which a resin and a fiber-reinforced resin layer containing fibers are laminated,
a laminating step of laminating a sheet-like fiber-reinforced resin material containing resin and fibers on the resin foam sheet to produce a laminate;
The core material is made of the resin foam sheet formed by applying pressure in the thickness direction to the heated laminate, and the fiber-reinforced resin layer is made of the fiber-reinforced resin material. A molding process is carried out to produce a resin composite.
In the lamination step,
The laminate is produced using the resin foam sheet that has secondary foamability and has a score line provided on at least one surface to form a plurality of regions divided by the score line. death,
In the molding process,
Performing the molding on the laminate that is bent in a direction in which the width of the score line is widened to form a V-groove-shaped gap at the location where the score line is provided, and foaming the resin. The molding is carried out under temperature conditions such that the sheet increases in volume by 50% or more due to secondary foaming,
producing the resin composite in which the gap is narrowed by increasing the volume of the resin foam sheet;
A method for producing a resin composite is provided.

According to the present invention, there is provided a resin foam sheet that allows easy production of a resin composite having a three-dimensional shape, and a method for producing a resin composite that allows the production of a resin composite using a simple method. .

FIG. 1 is a schematic perspective view showing a resin composite of one embodiment. FIG. 2 is a schematic perspective view showing the resin composite shown in FIG. 1 in an exploded state. FIG. 3 is a schematic perspective view showing a resin foam sheet used as a core material of a resin composite. FIG. 4A is a schematic plan view showing an example of a score line provided in a resin composite. FIG. 4B is a schematic plan view showing an example of a score line provided in the resin composite. FIG. 5 is a schematic perspective view showing the state of the resin foam sheet at the time of manufacturing the resin composite. FIG. 6 is a schematic perspective view of the first mold used for manufacturing the resin composite in the example. FIG. 7 is a schematic perspective view of the second mold used for manufacturing the resin composite in the example.

A resin composite according to an embodiment of the present invention will be described below. The resin composite of this embodiment has a curved plate shape as shown in FIGS. 1 and 2, and has a semi-cylindrical shape in which a cylinder is divided in half along a plane parallel to the central axis. More specifically, the resin composite of this embodiment has a shape similar to an upside-down rain gutter. The resin composite 100 of this embodiment has a longitudinal direction X and a lateral direction Y perpendicular to the longitudinal direction It is curved to . That is, the resin composite 100 has an arch-like cross-sectional shape in a plane perpendicular to the longitudinal direction X.

The resin composite 100 shown in FIGS. 1 and 2 has a rectangular shape in plan view. The rectangle has a long side along the longitudinal direction X and a short side along the short side direction Y. The resin composite 100 has a thickness direction Z that is perpendicular to the longitudinal direction X and the transverse direction Y.

In the resin composite 100 according to the present embodiment, surface materials having fiber-reinforced resin layers 2 are laminated on both sides of a plate-shaped core material 1 . In the resin composite 100 of this embodiment, the surface material is comprised only of the fiber-reinforced resin layer 2. The surface material may be provided with a film layer, a coating layer, or the like. In this embodiment, these may be provided outside the fiber-reinforced resin layer 2 to improve the aesthetic appearance of the resin composite 100. The resin composite 100 according to the present embodiment has a structure in which a core material 1 is sandwiched between two fiber-reinforced resin layers 2. That is, the resin composite 100 includes a first fiber-reinforced resin layer (first fiber-reinforced resin layer 2a) that constitutes one surface 100a, and a second fiber-reinforced resin layer (second fiber-reinforced resin layer) that constitutes the other surface 100b. The fiber-reinforced resin layer 2b) is provided.

The core material 1 includes a first surface (first surface 1a) and a second surface (second surface 1b) opposite to the first surface. The core material 1 has one or more sheet-like fiber-reinforced resin materials laminated on the first surface 1a side, and one or more sheet-like fiber reinforced resin materials are laminated on the second surface 1b side opposite to the first surface 1a. A plurality of fiber reinforced resin materials are laminated. The two fiber-reinforced resin layers 2a and 2b in this embodiment, which are composed of a plurality of fiber-reinforced resin materials, may have the same or different structures.

The two fiber-reinforced resin layers 2a and 2b in this embodiment have a common structure. Each fiber-reinforced resin layer 2a, 2b includes a first surface and a second surface opposite to the first surface, and the first surface of each fiber-reinforced resin layer 2a, 2b is The inner surface is the adhesive surface to the core material 1. The second surfaces of the fiber-reinforced resin layers 2a, 2b are the outer surfaces of the fiber-reinforced resin layers 2a, 2b, and are one surface 100a and the other surface 100b of the resin composite 100.

The core material 1 in this embodiment is made of a resin foam sheet. The resin foam sheet in this embodiment can increase in volume by 50% or more through secondary foaming by heating. It is more preferable that the foamed resin sheet can increase in volume by 60% or more by secondary foaming by heating, and even more preferably by 70% or more. The resin foam sheet in this embodiment has a rectangular shape as shown in FIGS. 3 and 4A, and more specifically, the long side parallel to the longitudinal direction X and the short side parallel to the transverse direction Y of the resin composite 100. It is a rectangle with sides.

The resin foam sheet 10 in this embodiment has a first surface 10a on which a fiber-reinforced resin material forming the first fiber-reinforced resin layer 2a is laminated, and a fiber-reinforced resin forming the second fiber-reinforced resin layer 2b. and a second surface 10b on which materials are laminated. The resin foam sheet 10 is provided with a score line 11 on at least one of the first surface 10a and the second surface 10b. The cut lines 11 are provided so as to divide the surface of the resin foam sheet 10 into a plurality of regions.

In the resin foam sheet 10 of this embodiment, a score line 11 is provided on the first surface 10a, which is the outer surface of the resin composite 100 having an arch-like cross-sectional shape. That is, the resin foam sheet 10 is provided with the cut lines 11 on the outer surface of the bent or curved shape provided in the resin composite 100.

The cut line 11 of this embodiment is provided so as to extend along the longitudinal direction X. The resin foam sheet 10 of this embodiment has a plurality of score lines 11 on the first surface 10a, which are arranged parallel to each other at intervals in the transverse direction Y. Therefore, the shapes of the individual regions 12 divided by the score lines 11 on the first surface 10a are such that the dimension in the longitudinal direction X is the same as that of the resin foam sheet 10, and the dimension in the transverse direction Y is the same as that of the resin foam sheet 10. It is a long and narrow rectangle (band-shaped) that is a fraction of the size of the original. On the first surface 10a of this embodiment, these strip-shaped regions 12 are lined up in the transverse direction Y.

When a bent or curved shape is formed in the resin composite 100, tensile stress is applied to the outer surface of the core material 1. The score line 11 in this embodiment extends in a direction that is approximately perpendicular to the direction in which stress is applied. Therefore, when rolling the flat resin foam sheet 10 into a semi-cylindrical shape similar to the shape of the resin composite 100, a gap is provided between adjacent regions 12 so that the width of the score line 11 is widened. It will be done. The resin foam sheet 10 of this embodiment can be changed into a semi-cylindrical shape without applying an excessively large force, and can be deformed without buckling or cracking even at room temperature. can.

The score line 11 of this embodiment may be formed by scanning the surface of the resin foam sheet 10 with a blade such as a razor or a cutter knife, or may be formed using a mold such as a Thomson blade type. good.

The score lines 11 of this embodiment may be provided along a plurality of directions that intersect with each other. For example, as shown in FIG. 4B, there are many small triangular areas 12 surrounded by the score lines 11. may be formed. The resin foam sheet 10 having such score lines 11 is suitable for forming not only a simple shape such as a semi-cylindrical shape but also a resin composite having a complicated shape.

It is preferable that the cut lines 11 of this embodiment are provided so that the shape of the region 12 is either a polygon such as a triangle, a quadrangle, or a hexagon, or a circle. When the shape of the region 12 is a polygon, the polygon does not have to be a regular polygon. When the shape of the region 12 is circular, the circle does not have to be a perfect circle and may be an ellipse or the like. The cut line 11 does not need to be formed linearly, and may be curved, such as a circular arc or a wavy line.

In the resin foam sheet 10 of this embodiment, the score lines 11 may be provided on both sides. When the score lines 11 are provided on both sides, the pattern of the score lines 11 on one side and the pattern of the score lines 11 on the other side may be different. For example, the cut lines 11 may be provided in a pattern as shown in FIG. 4A on one side, and the cut lines 11 may be provided in a pattern as shown in FIG. 4B on the other side.

The distance (L) between adjacent score lines 11 can be, for example, 5 mm or more. The distance (L) may be 6 mm or more, or 7 mm or more. The distance (L) can be, for example, 100 mm or less. The distance (L) may be 80 mm or less, or may be 60 mm or less. The distance (L) may be 50 mm or less, or 30 mm or less. When the score lines 11 extend in three directions like the resin foam sheet 10 illustrated in FIG. 4B, the distance between the score lines 11 in each direction can also be set in the same manner as described above. In that case, the distance (L1) between the score lines 11 at the score lines 11 extending in the first direction and the distance between the score lines 11 at the score lines 11 extending in the second direction. (L2) and the distance (L3) between the score lines 11 extending in the third direction may be the same or different.

The average cutting depth at the cutting line 11 is preferably 0.3 times (0.3 t) or more, and 0.4 times (0.4 t) the average thickness (t) of the resin foam sheet 10. More preferably, it is 0.5 times (0.5 t) or more. If the depth of cut at the cut line 11 is too deep, the resin foam sheet 10 must be handled carefully to prevent it from being cut. In order to make the resin foam sheet 10 easy to handle, the average cutting depth at the score line 11 should be 0.9 times (0.9 t) or less the average thickness (t) of the resin foam sheet 10. It is preferably 0.8 times (0.8 t) or less.

The thickness of the resin foam sheet 10 can be 0.5 mm or more. The thickness of the resin foam sheet may be 0.6 mm or more, or 0.8 mm or more. The thickness of the resin foam sheet 10 can be 5 mm or less. The thickness of the resin foam sheet 10 may be 4 mm or less, or 3 mm or less.

The resin foam sheet 10 can be made of, for example, polyester resin foam, polystyrene resin foam, polycarbonate resin foam, acrylic resin foam, or the like. The core material 1 may be an extruded foam sheet obtained by an extrusion foaming method. The core material 1 may be a sheet-shaped foam obtained by in-mold foam molding, or a resin foam sheet produced by slicing a block-shaped foam obtained by in-mold foam molding. .

The resin foam sheet 10 is preferably a polyester resin foam such as a polyethylene terephthalate resin foam, or a polycarbonate resin foam in terms of its excellent strength. It is particularly preferable that the resin foam sheet 10 is a polyethylene terephthalate resin foam. Polyester resin foam sheets and polycarbonate resin foam sheets do not soften to a state where they can be easily molded unless heated to high temperatures, so the advantage obtained by using them as the resin foam sheet 10 in this embodiment is that they can be easily deformed at room temperature. big. Furthermore, since polyester resin foam sheets and polycarbonate resin foam sheets are less susceptible to compressive deformation, it is easy to maintain a constant depth of the blade when providing the cut line 11.

As the resin foam sheet 10 of this embodiment, for example, a resin foam sheet containing a polyester resin can be adopted. Examples of the polyester resin contained in the resin foam sheet include polyethylene terephthalate resin, polybutylene terephthalate resin, polytrimethylene terephthalate resin, polyethylene naphthalate resin, and polybutylene naphthalate resin. The polyester resin does not need to be an aromatic polyester resin as described above, and may be, for example, an aliphatic polyester resin such as a polylactic acid resin or a polybutylene succinate resin.

The apparent density of the resin foam sheet 10 is preferably 100 kg/m ³ or more. The resin foam sheet may have an apparent density of 200 kg/m ³ or more. The apparent density of the resin foam sheet is preferably 700 kg/m ³ or less. The resin foam sheet may have an apparent density of 500 kg/m ³ or less.

The apparent density (D) of the resin foam sheet 10 can be determined as the arithmetic mean value of the apparent densities of samples cut out from multiple locations (for example, 4 or 5 locations) on the resin foam sheet 10. Each sample can be measured, for example, based on the method described in JIS K7222-2005 "Foamed plastics and rubber - How to determine apparent density." Specifically, the volume (V (m ³ )) and mass (M (kg)) of a test piece of 100 cm ³ or more that was cut without changing the original cell structure were measured, and the volume (V) The apparent density can be calculated by determining the ratio (M/V) of the mass (M) to the mass (M). If it is difficult to collect a test piece of 100 cm ³ or more, the apparent density may be calculated by collecting a sample as large as possible.

The resin foam sheet 10 has secondary foaming properties as described above. The secondary foamability of the resin foam sheet 10 is measured without the score lines 11 being provided. Note that the secondary foamability appears to be lower after the score line 11 is provided, so when checking whether the desired secondary foamability is achieved, it is necessary to The secondary foamability may be measured using the resin foam sheet 10.

The secondary foamability of the resin foam sheet 10 can be determined by the volume increase rate of the resin foam sheet 10 before and after heating. The volume increase rate can be determined from the ratio of the thickness of the resin foam sheet 10 before and after heating. The volume increase rate (thickness increase rate) of the resin foam sheet 10 due to secondary foaming can be determined by the method described in the Examples.

It is preferable that the resin foam sheet 10 exhibits a volume increase rate (thickness increase rate) of at least 50% (more preferably 60% or more, even more preferably 70% or more) at a heating temperature of 180°C. The temperature exhibiting a volume increase rate (thickness increase rate) of 50% or more (more preferably 60% or more, even more preferably 70% or more) is more preferably 170°C or less, and preferably 160°C or less. More preferably, the temperature is particularly preferably 150°C or lower. The temperature at which the resin foam sheet 10 exhibits a volume increase rate (thickness increase rate) of 50% or more (more preferably 60% or more, even more preferably 70% or more) is preferably 100° C. or higher. As the resin foam sheet 10, for example, one that can increase in volume by 50% or more by secondary foaming by heating at 130° C. can be used.

In order to produce good secondary foaming, the resin foam sheet 10 may contain a foaming agent. Examples of the blowing agent include inorganic physical blowing agents such as carbon dioxide and nitrogen gas, organic physical blowing agents such as hydrocarbons and their halides, and chemical blowing agents such as ADCA and OBSH. Among these, the blowing agent is preferably an organic physical blowing agent because it is advantageous in exhibiting a plasticizing function for the resin and exhibiting good secondary foamability. As the organic physical blowing agent, propane, butane (n-butane, i-butane, mixtures thereof, etc.), pentane (n-pentane, i-pentane, cyclopentane, mixtures thereof, etc.), etc. can be used. .

The foaming agent content of the resin foam sheet 10 is usually at most 10% by mass, preferably 0.15% to 5% by mass, and 0.25% to 3.0% by mass. is more preferable.

The foaming agent content of the resin foam sheet 10 can be determined as follows.
(Blowing agent content)
First, the mass W1 of a sample of the resin foam sheet 10 is measured.
Next, the mass W2 of the foaming agent contained in the resin foam sheet 10 is measured.
The mass (W2) of the blowing agent can be measured using a gas chromatograph, and specifically, can be measured in the following manner.

Collect 10 to 30 mg of sample from the resin foam sheet, place it in a 20 mL vial, weigh it accurately, seal the vial, set it on a gas chromatograph equipped with an autosampler, and heat the vial at 210°C for 20 minutes. After that, the gas in the upper space of the vial is quantitatively analyzed by the MHE (Multiple Headspace Extraction) method, and the mass W2 of the foaming agent contained in the foaming layer is measured.

The MHE method referred to herein is a quantitative method that utilizes the attenuation of the peak area obtained by repeatedly releasing a gas phase gas in gas-solid equilibrium.
[GC measurement conditions]
Measuring device: Gas chromatograph Clarus500 (manufactured by Perkin-Elmer)
Column: DB-1 (1.0 μm x 0.25 mmφ x 60 m: manufactured by J&W)
Detector: FID
GC oven heating conditions: initial temperature 50°C (6 minutes)
Heating rate: 40℃/min (up to 250℃)
Final temperature: 250℃ (1.5 minutes)
Carrier gas (He), inlet temperature: 230°C, detection temperature: 310°C
Range: 20
Vent gas 30mL/min (He), additional gas 5mL/min (He)
Gas pressure: initial pressure 18psi (10 minutes), pressure increase rate: 0.5psi/min (up to 24psi)

[HS measurement conditions]
Measuring device: HS autosampler TurboMatrix HS40 (manufactured by Perkin-Elmer)
Heating temperature: 210°C, heating time: 20 minutes, pressurized gas pressure: 25 psi, pressurizing time: 1 minute,
Needle temperature: 210℃, Transfer line temperature: 210℃, Sample introduction time: 0.08 minutes

[Calculation conditions]
(butane)
Standard gas for calibration curve: Mixed gas (manufactured by GL Sciences)
Mixed gas content: i-butane approximately 1% by mass, n-butane approximately 1% by mass, balance nitrogen Calculation method: Calculate the amount of blowing agent in the sample using the MHE method. All results are expressed as i-butane equivalent.
(pentane)
Standard gas for calibration curve: Mixed gas (manufactured by GL Sciences)
Mixed gas content: i-pentane approximately 1% by mass, n-pentane approximately 1% by mass, balance nitrogen Calculation method: Calculate the amount of blowing agent in the sample using the MHE method. All results are expressed as i-pentane equivalent.

The foaming agent content in the resin foam sheet 10 can be calculated based on the following formula.
Foaming agent content (mass%) = 100 x W2/W1

At the location where the cut line 11 is formed, a cut surface is formed in the resin foam sheet 10 halfway to the opposite surface of the resin foam sheet 10, and the cut surfaces are in contact with each other. There is. When the resin foam sheet 10 of this embodiment is rolled into a semi-cylindrical shape similar to the shape of the resin composite 100 as described above, the adjacent regions 12 are arranged such that the width of the score line 11 is widened. A gap is provided between them. Then, the cut surfaces spread out in a V-shape, and a groove (V groove) having a V-shaped cross section in a plane perpendicular to the score line 11 is formed on the first surface 10a side of the resin foam sheet 10. be done. If the V-groove-shaped gap 13 formed in this way is left as it is, the fiber-reinforced resin material will enter during the manufacture of the resin composite 100, resulting in streak-like formation on the surface of the first fiber-reinforced resin layer 2a. It can also cause dents. Moreover, this gap 13 may also cause voids or areas where fibers are exposed to be generated on the surface of the fiber-reinforced resin layer 2.

Since the resin foam sheet 10 of this embodiment has excellent secondary foaming properties as described above, the gap 13 can be narrowed by increasing the volume of the resin foam sheet 10 when manufacturing the resin composite 100. That is, the expansion force in the secondary foaming of the resin foam sheet 10 acts to cause adjacent cut surfaces to approach each other via the gap 13, and acts as a force that narrows the gap 13. Accordingly, in this embodiment, it is possible to suppress appearance defects from occurring in the resin composite 100. At this time, the gap 13 may be narrowed until the gap 13 is completely closed, or it may be narrowed while leaving a portion of the gap 13. That is, in this embodiment, a portion of the gap 13 may be left to allow a small amount of resin to flow in, thereby exerting an excellent anchoring effect between the fiber-reinforced resin layer 2 and the core material 1. .

By using the resin foam sheet 10 having secondary foamability as described above, it is possible to form the core material 1 with a high expansion ratio, and it is possible to form the resin composite 100 with excellent lightness.

The apparent density (D') of the core material 1 may be 200 kg/m ³ or less, or 150 kg/m ³ or less. The apparent density (D') of the core material 1 is preferably 110 kg/m ³ or less. The apparent density (D') of the core material 1 is more preferably 100 kg/m ³ or less, and even more preferably 80 kg/m ³ or less. The apparent density (D') of the core material 1 is preferably 30 kg/m ³ or more. The apparent density (D') of the core material 1 can be measured in the same manner as the apparent density of the resin foam sheet 10.

The ratio (D'/D) of the apparent density (D') of the core material 1 to the apparent density (D) of the resin foam sheet 10 is 0.9 in order to form the resin composite 100 with excellent lightness. It is preferable that it is below. The ratio may be 0.8 or less, 0.7 or less, or 0.6 or less. The ratio (D'/D) is, for example, 0.1 or more.

In order to form a resin composite 100 with a beautiful appearance and excellent strength, the thickness of the fiber reinforced resin layer 2 is preferably 0.40 mm or more. The thickness of the fiber reinforced resin layer 2 may be 0.50 mm or more, 0.60 mm or more, or 0.70 mm or more. The thickness of the fiber-reinforced resin layer 2 is, for example, 3.00 mm or less in order to form the resin composite 100 with excellent lightness. The thickness of the fiber reinforced resin layer 2 is preferably 2.00 mm or less.

The dimensions of the resin composite 100, the core material 1, and the fiber-reinforced resin layer 2 can be determined as an average value obtained by arithmetic averaging of measured values at multiple locations (for example, 4 or 5 locations). For example, the thicknesses of the resin composite 100, the core material 1, and the fiber-reinforced resin layer 2 can be determined as the arithmetic mean value of four measured values measured at the center of four sides of a rectangle.

The fiber-reinforced resin material constituting the fiber-reinforced resin layer 2 in this embodiment includes a base sheet made of fibers and a resin impregnated into the base sheet. The base sheet of this embodiment may be a nonwoven fabric or a woven fabric. The base sheet may be a sheet (UD material) in which fibers are simply aligned in one direction. When the base sheet is a woven fabric, the weave of the woven fabric may be a plain weave, a twill weave, or a satin weave. Examples of the fibers constituting the base sheet include alumina fibers, basalt fibers, rock wool, metal fibers, glass fibers, and carbon fibers. The fibers constituting the base sheet may be, for example, resin fibers such as aramid fibers and polyetheretherketone fibers.

The base sheet of this embodiment is preferably made of either glass fiber or carbon fiber. The carbon fibers may be pitch-based carbon fibers or PAN-based carbon fibers.

The fiber content in the fiber-reinforced resin material and the fiber-reinforced resin layers 2a and 2b is usually 50% by mass or more. The fiber content may be 55% by mass or more, or 60% by mass or more. The fiber content is, for example, 80% by mass or less. The fiber content may be 75% by mass or less, or 70% by mass or less.

The resin constituting the fiber-reinforced resin material together with the base sheet may be a thermoplastic resin or a thermosetting resin. The resin is preferably a thermosetting resin since it is advantageous for the fiber-reinforced resin material to exhibit excellent strength. That is, it is preferable that the fiber-reinforced resin layers 2a and 2b of this embodiment are composed of prepreg sheets containing a base sheet and an uncured thermosetting resin impregnated into the base sheet. Examples of the thermosetting resin include epoxy resin and unsaturated polyester resin.

The resin composite of this embodiment can be manufactured, for example, by using the prepreg sheet as a fiber-reinforced resin material and integrating the prepreg sheet and the resin foam sheet 10 by a hot press method.

The resin composite of this embodiment may be manufactured, for example, after confirming the secondary foamability of the resin foam sheet 10. In the manufacturing method of the resin composite 100, it is confirmed at what temperature and what volume increase rate the resin foam sheet 10 exhibits, and the flow start temperature and curing temperature of the resin contained in the prepreg sheet are taken into consideration. The heat press conditions may also be set using the following methods. In addition, in order to narrow the gap 13 and obtain a resin composite 100 with a good appearance, heat pressing is performed so that the resin foam sheet 10 is 50% or more (more preferably 60% or more, still more preferably 70% or more) by secondary foaming. Preferably, it is carried out under temperature conditions that increase the volume.

In the method for manufacturing a resin composite of this embodiment, as described above, a preliminary examination step is first performed in which the secondary foamability of the resin foam sheet 10 is confirmed and hot press conditions are determined. In the method for manufacturing a resin composite of this embodiment, a cutting step of providing score lines 11 in the resin foam sheet 10 may be further carried out. In the method for manufacturing a resin composite of this embodiment, a lamination step may be carried out in which a fiber-reinforced resin material is laminated on one or both sides of the resin foam sheet 10 provided with the score lines 11 to produce a laminate. In the method for manufacturing a resin composite of this embodiment, a molding step is further performed in which the laminate is molded using a mold to produce a resin composite 100 having a three-dimensional shape. In addition, in the method for manufacturing a resin composite of this embodiment, since excess resin may adhere around the resin composite 100 after the molding process, a finishing process may be performed to remove it. .

The cutting step can be performed using a blade mold as described above, or a cutting tool such as a razor or a cutter knife.

In the lamination step, the resin foam sheet is used which has secondary foamability and has a score line provided on at least one surface to form a plurality of regions separated by the score line. The laminate is produced. In the lamination step, the fiber-reinforced resin material may be laminated on the resin foam sheet 10 bent into the same shape as the core material 1 in the resin composite 100, or the fiber-reinforced resin material may be laminated on the resin foam sheet 10 in a flat state. may be laminated. That is, the three-dimensional shape of the resin composite 100 may be provided in the laminate in the lamination process, or a flat laminate is formed in the lamination process, and then the three-dimensional shape is provided to the laminate in the molding process. You can also do this.

In the molding step, heat pressing is performed to apply pressure in the thickness direction to the heated laminate to form the core material made of the resin foam sheet and the core material made of the fiber reinforced resin material. Any method may be used as long as it can produce a resin composite including a fiber-reinforced resin layer.

The hot pressing may be performed by pressing a mold between hot plates or by using an autoclave. Therefore, the mold used in the molding step may be male or female, or may be only one of the male and female molds.

In the forming step, the heat pressing is performed on the laminate which is bent in a direction in which the width of the score line is widened and a V-groove-shaped gap is formed at the location where the score line is provided. , by performing the heat pressing under temperature conditions such that the resin foam sheet increases in volume by 50% or more (more preferably 60% or more, even more preferably 70% or more) due to secondary foaming, thereby increasing the volume of the resin foam sheet. The resin composite in which the gap is narrowed can be produced. As mentioned above, in the molding process, the gap is not completely filled, and a gap narrower than before secondary foaming is left, resulting in resin breakage (exposure of fibers) on the surface of the fiber-reinforced resin layer. A small amount of resin from the fiber-reinforced resin material can be allowed to flow into this narrow gap to the extent that it does not occur.

Due to the above, the molding process of this embodiment not only makes it possible to produce a resin composite with a good appearance, but also exhibits strong adhesive force between the core material and the fiber-reinforced resin layer due to the anchor effect. It is possible to produce a resin composite. Further, in this embodiment, by using a resin foam sheet provided with score lines as a constituent material of the core material, even a resin composite having a complicated shape can be easily manufactured.

The above-mentioned examples of the resin foam sheet, the resin composite, and the method for manufacturing the resin composite in the present embodiment are merely for explaining specific examples, and the resin foam sheet, the resin composite, and the resin composite of the present embodiment The method for producing the body and the resin composite is not limited to the above-mentioned examples. Therefore, the resin foam sheet, the resin composite, and the method for manufacturing the resin composite of this embodiment are not limited to the above-mentioned exemplary embodiments, and various changes may be made. That is, the present invention is not limited to the above-mentioned examples.

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

First, two molds as shown in FIGS. 6 and 7 were prepared as molds for use in manufacturing a resin composite. The first mold M1 shown in FIG. 6 is a mold having a size of 200 mm x 200 mm and has a spherically recessed molding surface MP1 with a radius of curvature of 200 mm. The second mold M2 shown in FIG. 7 is a mold having a size of 200 mm x 200 mm and has a molding surface MP2 recessed into a semi-cylindrical shape with a radius of curvature of 100 mm.

As materials for forming the fiber-reinforced resin layer, two types of prepreg sheets shown in Table 1 below were prepared.

As a material for forming the core material, a resin foam sheet (polyethylene terephthalate resin foam sheet) containing two types of polyester resins shown in Table 2 below was prepared.

(Measurement of volume increase rate)
The volume increase rate of the resin foam sheet was measured as follows.
The size of the test piece was 200 x 200 x original thickness (mm).
Two straight lines perpendicular to each other in the vertical and horizontal directions were drawn in the center of the test piece.
Straight lines were drawn connecting the midpoints of each of the opposing sides, the length of each straight line was measured, and the measured value was taken as the initial length (L01, L02: mm).
Further, the thickness at four points at the midpoint of each side was measured with a digital caliper, and the average value of the measured values at the four points was taken as the initial thickness (t0: mm).
The test piece was placed in a hot air circulation dryer at 130°C for 1 hour.
Take out the test piece and leave it in a place under standard conditions (JIS K7100:1999 symbol "23/50" (temperature 23°C, relative humidity 50%), class 2 standard atmosphere) for 1 hour, and then place it in the same place as before heating. The length (L11, L12: mm) and thickness (t1: mm) were measured, and the volume increase rate (thickness increase rate) was calculated using the following formula.

V0=(L01×L02×t0)
V1=(L11×L12×t1)
S=(V1-V0)/V0×100
S=: Volume increase rate (%)
V1: Volume after heating (mm ³ )
V0: Initial volume (mm ³ )

(Example 1)
(Preparation of laminate)
Fiber-reinforced resin material (thickness: 0.22 mm, fiber basis weight: 200 g/m ² , Mitsubishi Chemical Corporation), in which a base sheet made of woven carbon fiber in a twill weave is impregnated with 45% by mass of uncured epoxy resin. ``Pyrophil Prepreg TR3523-381GMX'' manufactured by Manufacturer Co., Ltd.) was cut out to 140 mm x 140 mm, and four sheets were prepared. Resin foam sheet 1 (thickness: 2.0 mm, basis weight: 600 g/m ² , resin: polyester resin) was cut into a size of 140 mm x 140 mm, and cut was performed using a plotter cutter according to the specifications listed in Table 3. Ta.

Next, a mold release agent ("Chemlease 2166" manufactured by Chemlease Japan Co., Ltd.) was applied to the three-dimensional aluminum mold shown in Fig. 6 (dimensions: 200 mm x 200 mm, spherical shape, spherical R100) and left for one day. A mold release treatment was performed.
Next, the prepared fiber-reinforced resin material and the resin foam sheet were laminated in the mold according to the order listed in Table 3, aligning the outer peripheral edges to produce a laminate, and the sheet was laminated so as to follow the shape of the molding surface. Preforming was carried out.

After that, the mold and the preformed laminate are completely wrapped with a release film ("Toray Fan YM17S" manufactured by Toray Industries, Inc.) and a breather cloth ("AIRWEAVE N4" manufactured by AIRTECH Inc.), and further wrapped in cylindrical bagging. After wrapping with film, the edges of the bagging film were joined with sealant tape, and the mold and preliminary laminate were sealed with the bagging film to produce a laminate structure.In addition, a bag valve was attached to a part of the bagging film. Placed.

Next, the laminated structure was supplied into an autoclave, the bag valve of the laminated structure was connected to a vacuum line, and the space sealed with the bagging film was reduced to a degree of vacuum of 0.10 MPa. Note that the pressure reduction in the space was continued thereafter. Thereafter, the laminate was heated to a surface temperature of 90°C.

Next, the laminate was heated to 130° C. and hot pressed for 60 minutes, and the laminate was pressed in the thickness direction at a pressure of 0.13 MPa. The epoxy resin was then cured by this heating. Thereafter, the laminate was cooled to 30° C. to produce a resin composite in which fiber-reinforced resin layers were laminated on both sides of the core material.

Table 3 below shows whether or not a laminate can be preformed in the production of a resin composite.
In addition, the produced resin composite was evaluated as follows.

(Appearance quality)
The appearance of the obtained resin composite was visually observed, and the surface quality of the fiber-reinforced resin layer was evaluated in five grades according to the following criteria. The results are also shown in Table 3.

Judgment 1: When the number of voids within an area of 50 mm x 50 mm is 101 or more.
Judgment 2: When the number of voids within the 50 mm x 50 mm area is 71-100.
Judgment 3: When the number of voids within the 50 mm x 50 mm area is 51-70.
Judgment 4: When the number of voids within the 50 mm x 50 mm area is 6-50.
Judgment 5: When the number of voids within the 50 mm x 50 mm area is 0-5.

(Examples 2-4, Comparative Examples 1-2)
A resin composite was produced in the same manner as in Example 1, except that the type of resin foam sheet and the structure of the fiber-reinforced resin layer were changed as shown in Table 3, and evaluated in the same manner as in Example 1.
The results are also shown in Table 3.

From the above, it can be seen that according to the present invention, a resin composite having a three-dimensional shape can be easily produced.

1: core material, 1a: first surface, 1b: second surface,
2: fiber reinforced resin layer, 2a: first fiber reinforced resin layer, 2b: second fiber reinforced resin layer,
10: resin foam sheet, 11: score line, 12: area (divided by score line),
100: Resin composite X: Longitudinal direction Y: Short direction Z: Thickness direction

Claims (5)

A core material made of resin foam sheet,
A resin foam sheet used to constitute the core material of a resin composite in which a fiber-reinforced resin layer made of a sheet-like fiber-reinforced resin material containing resin and fibers is laminated,
It is possible to increase the volume by more than 50% through secondary foaming by heating at 130℃.
On at least one surface,
A resin foam sheet that is provided with score lines and has a plurality of regions separated by the score lines. The resin foam sheet according to claim 1, containing a polyester resin. The resin foam sheet according to claim 1 or 2, containing a hydrocarbon foaming agent. On the one surface,
The score lines are provided in a plurality of directions along the surface, and a plurality of regions surrounded by the score lines are formed,
The resin foam sheet according to any one of claims 1 to 3, wherein the shape of the region is polygonal or circular. A core material made of resin foam sheet,
A method for producing a resin composite in which a resin and a fiber-reinforced resin layer containing fibers are laminated,
a laminating step of laminating a sheet-like fiber-reinforced resin material containing resin and fibers on the resin foam sheet to produce a laminate;
The core material is made of the resin foam sheet formed by applying pressure in the thickness direction to the heated laminate, and the fiber-reinforced resin layer is made of the fiber-reinforced resin material. A molding process is carried out to produce a resin composite.
In the lamination step,
The laminate is produced using the resin foam sheet that has secondary foamability and has a score line provided on at least one surface to form a plurality of regions divided by the score line. death,
In the molding process,
Performing the molding on the laminate that is bent in a direction in which the width of the score line is widened to form a V-groove-shaped gap at the location where the score line is provided, and foaming the resin. The molding is carried out under temperature conditions such that the sheet increases in volume by 50% or more due to secondary foaming,
producing the resin composite in which the gap is narrowed by increasing the volume of the resin foam sheet;
Method for manufacturing resin composite.