JP2020138482A - Resin composite - Google Patents

Abstract

To provide a resin composite having excellent compressive resistance under high temperature environment as well as peel resistance.SOLUTION: A resin composite has a resin core material, and a fiber-reinforced resin layer that covers the external surface of the core material, wherein the core material contains a polycarbonate resin, the fiber-reinforced resin layer containing an epoxy resin.SELECTED DRAWING: Figure 1

Description

The present invention relates to a resin composite. More specifically, the present invention relates to a resin composite having excellent peel resistance and compression resistance in a high temperature environment.

Conventionally, a resin composite including a resin core material and a fiber-reinforced resin layer arranged on the outer surface of the resin core material is known (for example, Patent Document 1).

In the resin composite described in Patent Document 1, a polyolefin-based resin is used as the resin of the core material, a modified polyolefin-based resin layer is arranged between the core material and the fiber-reinforced resin layer, and the modified polyolefin-based resin layer is arranged. The core material and the fiber-reinforced resin layer are bonded to each other. As a result, the peel resistance between the core material and the fiber reinforced resin layer is enhanced. Such a resin composite is used for, for example, an automobile part such as a front-end module base material (a resin frame for collectively assembling a radiator, a shroud, a lamp, etc.).

Patent No. 5034502

By the way, since the thermal deformation temperature is generally relatively low, when the front-end module base material is produced by a resin composite using a polyolefin-based resin as the resin of the core material, the front-end module base material is in a high temperature environment. Compressibility may decrease when exposed to (for example, 120 ° C.).

Therefore, in the resin composite, it is desired that the core material and the fiber reinforced resin layer have excellent peel resistance and compressibility in a high temperature environment.

Therefore, an object of the present invention is to provide a resin composite having excellent compression resistance in a high temperature environment in addition to peeling resistance.

As a result of diligent studies by the present inventors, in a resin composite provided with a resin core material and a fiber-reinforced resin layer covering the outer surface of the core material, the core using a resin composition containing a polycarbonate resin is used. It was found that by constructing the material and constructing the fiber-reinforced resin layer using a resin composition containing an epoxy resin, not only peeling resistance but also compression resistance in a high temperature environment is excellent. This led to the idea of the present invention.

That is, the resin composite according to the present invention is
A resin core material and a fiber reinforced resin layer covering the outer surface of the core material are provided.
The core material contains a polycarbonate resin and contains
The fiber reinforced resin layer contains an epoxy resin.

According to such a configuration, a resin core material and a fiber reinforced resin layer covering the outer surface of the core material are provided, the core material contains a polycarbonate resin, and the fiber reinforced resin layer is: Since it contains an epoxy resin, the obtained resin composite has excellent compression resistance in a high temperature environment in addition to peeling resistance.

According to the present invention, it is possible to provide a resin composite having excellent compression resistance in a high temperature environment in addition to peeling resistance.

The figure which shows the resin composite which concerns on one Embodiment of this invention. (A) is a perspective view which shows the whole structure of a resin composite. (B) is a cross-sectional view showing a cut surface along the line I-I.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Hereinafter, an example in which the resin composite 1 has a flat plate structure will be described.

The resin composite 1 according to the present embodiment includes a resin core material 10 and a fiber reinforced resin layer 20 that covers the outer surface of the core material 10. The resin composite 1 according to the present embodiment is provided with a fiber-reinforced resin layer 20 on the outer surfaces of two surfaces of the core material 10 facing each other. That is, the resin composite 1 is provided with a sheet-shaped fiber reinforced resin layer 20 on one outer surface of the flat plate-shaped core material 10 and on the other outer surface facing the one outer surface.
In the resin composite 1, the foamed resin of the core material 10 contains a polycarbonate-based resin, and the resin of the fiber-reinforced resin layer 20 contains an epoxy resin.

In the present embodiment, the core material 10 is made of a beaded foam which is a foamed resin body.
The bead foam constituting the core material 10 is composed of foam particles obtained by secondary foaming pre-foam particles containing a foaming agent, and is formed by heat-sealing a plurality of foam particles to each other. is there. More specifically, the bead foam is prepared by adding a foaming agent to non-foamed resin particles (hereinafter, also referred to as “raw particles”) to prepare foamable particles, and the foamable particles are once foamed to obtain pre-foamed particles. Obtained, beads are foamed using pre-foamed particles. The raw grains are composed of a resin composition containing a polycarbonate-based resin as a main component.

The foamed particles include small bubbles having a bubble diameter of 10 μm or more and less than 200 μm and large cells having a bubble diameter of 300 μm or more and 1500 μm or less in a cross-sectional photograph taken at an area of 11.9 mm ^{2 at} a magnification of 30.
Further, the number of large bubbles per foamed particle is not particularly limited and may be a plurality of large cells, but if the number of large cells is too large, the bubble ratio becomes high and the mechanical properties of the foamed molded product are deteriorated. For this reason, although it depends on the bubble diameter of the large bubbles, it is preferable that only one large cell is present for each foamed particle.
Further, it is preferable that there is a difference of 300 μm or more between the average cell diameter of the small cells and the average cell diameter of the large cells. Due to this difference, it is possible to provide foamed particles that give a foamed molded product having improved mechanical properties. A more preferable difference is 300 μm to 600 μm. Here, the average cell diameter of the small cells is preferably in the range of 20 μm to 60 μm, and the average cell diameter of the large cells is preferably in the range of 400 μm to 1000 μm.

The average particle size of the foamed particles is preferably 2000 μm to 4000 μm, and more preferably 2500 μm to 3500 μm.
The outer shape of the foamed particles is not particularly limited as long as the foamed molded product can be produced, and examples thereof include a spherical shape, a substantially spherical shape, and a cylindrical shape. The foamed particles preferably have an outer shape represented by an average aspect ratio of 0.7 or more (upper limit is a true sphere of 1).
The foamed particles preferably have a bulk multiple of 30 to 2 times. When the bulk multiple is 30 to 2 times, it is possible to suppress an increase in the open cell ratio of the foamed particles, and it is possible to suppress a decrease in the foamability of the foamed particles during foaming of the foam molding. In addition, it is possible to prevent the bubbles of the foamed particles from becoming non-uniform, and it is possible to prevent the foamed particles from becoming insufficiently foamable during foam molding. The bulk multiple is more preferably 25 times to 3 times, and particularly preferably 20 times to 5 times.

The resin composition constituting the bead foam is the same as the resin composition of the foamed particles.
The bead foam has a plurality of foams having a small bubble having a bubble diameter of 10 μm or more and less than 200 μm and a large bubble having a bubble diameter of 300 μm or more and 1500 μm or less in a cross-sectional photograph taken at an area of 11.9 mm ^{2 at} a magnification of 30 times. It is composed of particles, and the foamed particles are fused to each other.
Further, the number of large bubbles per foamed particle is not particularly limited and may be a plurality of large cells, but if the number of large cells is too large, the bubble ratio becomes high and the mechanical properties of bead foaming are deteriorated. For this reason, although it depends on the bubble diameter of the large bubbles, it is preferable that only one large cell is present for each foamed particle.
Further, it is preferable that there is a difference of 300 μm or more between the average cell diameter of the small cells and the average cell diameter of the large cells. Due to this difference, it is possible to provide foamed particles that give beaded foams having improved mechanical properties. A more preferable difference is 300 μm to 600 μm. Here, the average cell diameter of the small cells is preferably in the range of 20 μm to 60 μm, and the average cell diameter of the large cells is preferably in the range of 400 μm to 1000 μm.

The average particle size of the fused foamed particles constituting the bead foam is preferably 2000 μm to 4000 μm, and more preferably 2500 μm to 3500 μm.
The outer shape of the fused foamed particles is not particularly limited as long as the beaded foam can be maintained.
The bead foam preferably has a multiple of 30 to 2 times. When the multiple is 30 to 2 times, it is possible to prevent the mechanical properties from becoming insufficient. In addition, it is possible to prevent the advantage of foaming from becoming smaller due to the increase in weight. The multiple is more preferably 25 times to 2 times, and particularly preferably 20 times to 5 times.
Accordingly, bead ^foam preferably has a density of ^{0.06g / cm 3 ~0.24g / cm 3} (60kg / m 3 ~240kg / m 3).
The maximum bending point stress per unit density of the bead foam is preferably 0.01 MPa / (kg / m ³ ) or more. Since the maximum bending point stress is 0.01 MPa / (kg / m ³ ), it is possible to prevent the bead foam from easily breaking.
The flexural modulus per unit density of the bead foam is preferably 0.2 MPa / (kg / m ³ ) or more. When the flexural modulus is 0.2 MPa / (kg / m ³ ) or more, the bead foam is deformed by the pressure applied when laminating and integrating a skin material such as fiber reinforced plastic on the surface of the bead foam. Can be suppressed.

The polycarbonate resin preferably has a polyester structure of carbonic acid and glycol or divalent phenol. From the viewpoint of further enhancing the heat resistance, the polycarbonate resin preferably has an aromatic skeleton. Specific examples of the polycarbonate resin include 2,2-bis (4-oxyphenyl) propane, 2,2-bis (4-oxyphenyl) butane, 1,1-bis (4-oxyphenyl) cyclohexane, and 1, Examples thereof include polycarbonate resins derived from bisphenols such as 1-bis (4-oxyphenyl) butane, 1,1-bis (4-oxyphenyl) isobutane, and 1,1-bis (4-oxyphenyl) ethane.
In addition, an aliphatic polycarbonate resin composed of carbonic acid and an aliphatic diol or an alicyclic diol can also be adopted. These may be copolymers containing a plurality of aliphatic diols or alicyclic diols, and the components derived from the aliphatic system represented by the aliphatic diol or the alicyclic diol in the molecular chain and the aromatic system. It may be a copolymer having a derived component.

Examples of the polycarbonate-based resin include a linear polycarbonate resin and a branched polycarbonate resin, and both of these may be blended. The polycarbonate-based resin may be a copolymer with an acrylic acid ester, but the proportion of components derived from the acrylic acid ester is preferably 50% by mass or less.
Further, the polycarbonate resin preferably has an MFR of 1 to 20 g / 10 minutes. Resins in this range are suitable for foaming and can be easily multiplied. A more preferred range of MFR is 2 to 15 g / 10 min.
Further, in the resin composition for obtaining a bead foam, the mass ratio of the polycarbonate resin to the total mass of the resin is preferably 70% by mass or more, more preferably 85% by mass or more, and 100%. It may be% by mass.

The resin composition for obtaining the bead foam may contain a resin other than the polycarbonate resin as a subcomponent. Examples of such resins include acrylic resins, saturated polyester resins, ABS resins, polystyrene resins, polyphenylene oxide resins, and the like. In the resin composition, the mass ratio of the other resin to the total weight of the resin is preferably 30% by mass or less, more preferably 15% by mass or less, and may be 0% by mass.
Further, the resin composition contains, as subcomponents other than the resin, a compatibilizer, a plasticizer, a flame retardant, a flame retardant aid, an antistatic agent, a spreading agent, a bubble modifier, a filler, a colorant, and a weather resistant agent. , Antistatic agent, lubricant, antifogging agent, fragrance and the like may be contained.

The bead foam preferably has a density (bulk density) of 0.6 g / cm ³ or less in order to make the resin composite 1 exhibit excellent lightness. The density of the bead foam is more preferably 0.4 g / cm ³ or less, and further preferably 0.2 g / cm ³ or less. The bead foam preferably has a density of 0.02 g / cm ³ or more in order to exert excellent strength in the resin composite 1. The density of the bead foam is more preferably 0.025 g / cm ³ or more, and more preferably 0.03 g / cm ³ or more.
The density of the beaded foam can be measured by the method described in Examples.

In general, gaps or the like are likely to be formed between adjacent foam particles on the surface or inside of the bead foam. In addition, some of the gaps are open on the surface of the bead foam, so that the resin of the fiber reinforced resin material can enter when the fiber reinforced resin layer 20 is formed. If there are gaps between the foamed particles or openings on the surface of the beaded foam, the resin composite 1 which is the final resin molded product may have a resin shortage in the fiber reinforced resin layer 20 or an unnecessary mass increase. It can be a thing.
Therefore, it is preferable not to form such a gap in the bead foam. The bead foam is a bead foam in which foam particles are densely packed due to its high air permeation resistance, and the bead foam is densely packed with foam particles. From this, the resin of the fiber-reinforced resin material does not permeate between the foamed particles in the bead foam, the resin shortage does not occur in the fiber-reinforced resin layer 20, and the resin composite 1 having a beautiful surface can be provided.

The bead foam preferably has an air permeation resistance of 30 s or more as measured by the cut out section. If it is less than 30 s, many gaps between the foamed particles inside the bead foam are formed. Therefore, the fiber reinforced resin layer 20 may be short of resin or may have an unnecessary mass increase. The permeation resistance is more preferably 40 s or more.
The air permeation resistance is obtained as an average value (average air permeation resistance) performed at a plurality of locations.
For the average air permeation resistance of the bead foam, 10 samples were taken from the bead foam, the air permeation resistance was measured for each sample in accordance with JIS P8117: 2009, and each air permeation resistance was measured. Can be obtained by arithmetically averaging.

When the bead foam has low heat-sealing properties between the foam particles, the resin of the fiber-reinforced resin material that has penetrated from the thin portion of the resin film travels through the interface between the foam particles and is deeper in the bead foam. May invade. Further, when the bead foam has a high open cell ratio, more resin of the fiber reinforced resin material that has invaded from the torn portion or the thin portion of the resin film easily invades into the foamed particles. Therefore, it is preferable that the bead foam has a high heat fusion rate and a high closed cell property.

Further, the bead foam preferably has a heat fusion rate (heat fusion rate between the foamed particles) of 50% or more. The heat fusion rate of the bead foam is more preferably 70% or more, and further preferably 80% or more.
The heat fusion rate of the beaded foam is determined by making a cut line with a depth of about 2 mm on the surface of the bead foam with a cutter knife, then dividing the bead foam into two along this cut line, and foaming in the fracture surface. For particles, the number of particles broken in the particles (a) and the number of particles broken at the interface between the particles (b) in an arbitrary range of 100 to 150 are counted, and the formula [( It can be obtained as a value obtained by substituting a) / ((a) + (b))] × 100.
The sample for measuring the fusion rate is basically a flat plate shape, with a thickness of about 30 mm, a width of about 300 mm, and a length of about 400 mm, and the cut line is directed toward the center of the measurement sample in the length direction in the width direction. It is formed so as to cross. When such a measurement sample cannot be collected from the bead foam, the fusion rate is determined by using a sample having a size that can be collected from the bead foam.

The bead foam preferably has an open cell ratio of 20% or less in order to make the resin composite 1 exhibit excellent strength. The open cell ratio of the bead foam is more preferably 15% or less, and further preferably 10% or less. The open cell ratio of the bead foam is usually 1% or more.
For the open cell ratio of the bead foam, 5 test pieces were cut out from the bead foam so as not to leave the epidermis, and each cut out test piece was used for 16 hours in a JIS K7100-1999 symbol 23/50, 2nd grade environment. After adjusting the state, the apparent volume (cm ³ ) was measured under the same environment, the volume was measured with an air comparison hydrometer, and the open cell ratio was calculated for each test piece using the following formula. It can be obtained by arithmetically averaging the bubble ratio.
-Open cell ratio (%) = 100 x (apparent volume-volume measured with an air comparison hydrometer) / apparent volume

In order to obtain a bead foam having excellent fusion properties between the foamed particles as described above, it is necessary to mold the pre-foamed particles using high-pressure steam. Specifically, in order to obtain the beaded foam of the present invention, it is preferable to mold the beaded foam at an absolute pressure of 0.8 MPa or more. Further, if the steam pressure is raised too much, the temperature at the time of molding rises too much and the foamed particles melt, making it difficult to obtain a molded product. Therefore, the steam pressure should be 1.2 MPa or less in absolute pressure. Is desirable, and molding at 1.1 MPa or less is more preferable.

However, when molding is performed with high-pressure steam, the pressure in the prefoamed particles may be defeated by the molding vapor pressure, causing shrinkage. If shrinkage occurs, even if the fusion rate is improved, gaps are generated between the foamed particles, which may result in a beaded foam having a low air permeation resistance. Therefore, in order to obtain a beaded foam having excellent fusion properties between foamed particles, high compression strength, and high air permeation resistance, the forming vapor pressure is set to 0.8 MPa or more in absolute pressure and is reserved. It is appropriate to give the foamed particles sufficient foaming power.

Specifically, it is appropriate to apply internal pressure to the prefoamed particles so as to satisfy the following formula.
And forming at the bubble internal pressure _{(P m)} steam pressure during ≧ molding _(P S)
Here _{P m} and _{P S} are both absolute pressure (MPa).
Further, the pressure inside the bubble (P _m ) at the time of molding is calculated by the following formula.
_{· P m = P f × (} T S +273) / 293 × V / V m
Here, _{P f} bubbles in the pressure in the pre-expanded particles (MPa), _{T S} is the saturated vapor temperature in the pressure (° C.), V is the volume of space within the pre-expanded particles ^(cm 3), _{V m} is It is the volume (cm ³ ) of the space in the pre-foamed particles after the pre-foamed particles are secondarily foamed by the molding steam and filled in the mold without gaps.
_{Furthermore, P f, T S, V} , V m is respectively calculated from the following equation.
P _f = 8.31 × 293 × (0.1 × V / 8.31/293 + W / M) / V
・ V = 100 × R / ρ _0-100 / ρ _s
・ V _m = 100 × R / ρ ₀ / R-100 / ρ _s
Here, W is the amount of internal pressure applied (mass%), M is the molecular weight of the internal pressure applied gas (g), R is the filling rate of the prefoamed particles, ρ ₀ is the bulk density of the prefoamed particles (g / cm ³ ), and ρ _S. Is the resin density (g / cm ³ ). The filling factor R of the prefoamed particles is 0.6.
Incidentally, _{T S} is calculated by the following equation from the value of _{P S.
· T S = 237.3 × Log (} P S × 10000 / 6.1078) / (7.5-Log (P S × 10000 / 6.1078))
Internal pressure can be applied to the pre-foamed particles by filling the pressurized container with the pre-foamed particles after producing the pre-foamed particles and then pressurizing and filling the pre-foamed particles with a gas such as air, nitrogen, or carbon dioxide. Further, the internal pressure application amount W can be calculated by measuring the mass of the pre-foamed particles before and after the internal pressure application is performed and using the following formula.
W (mass%) = (mass of prefoamed particles after applying internal pressure (g) -mass of prefoamed particles before applying internal pressure (g)) / mass of prefoamed particles before applying internal pressure (g) × 100
The bulk density of the pre-expanded particles, divided by the bulk volume of the pre-expanded particles obtained by reading the mass of pre-expanded particles from the measuring cylinder when weighed so that the pre-expanded particles to 800cm about ³ graduated cylinder 1000 cm ³ You can get it by doing.

In the present embodiment, the fiber reinforced resin layer 20 is made of a sheet-shaped fiber reinforced resin material containing a resin and fibers. The fiber reinforced resin layer 20 may be in direct contact with the outer surface of the core material 10. The fiber-reinforced resin material is made by impregnating fibers with resin. In the fiber reinforced resin material, the fibers are bound and integrated by the impregnated resin.
The method of impregnating the fiber with the resin is not particularly limited, and examples thereof include (1) a method of immersing the fiber in the resin, and (2) a method of applying the resin to the fiber.

As shown in FIG. 1B, the fiber-reinforced resin layer 20 according to the present embodiment has a two-layer structure formed by the first fiber-reinforced resin layer 20a and the second fiber-reinforced resin layer 20b. ing. The first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b may be composed of one sheet-shaped fiber reinforced resin material, or a plurality of sheet-shaped fiber reinforced resin materials are laminated. It may be configured. In the present embodiment, as shown in FIG. 1B, in the fiber-reinforced resin layer 20, the first fiber-reinforced resin layer 20a is in direct contact with the outer surface of the core material 10. The first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b do not have to have the same ratio of fibers and resins or the types of fibers and resins, and may be different from each other.
The fibers impregnated in the fiber-reinforced resin material may be in the state of short fibers or in the state of continuous fibers. When the fibers are continuous fibers, the fibers can be contained in the fiber reinforced resin layer 20 in the form of yarns such as drawn yarns and twisted yarns. The yarn can be woven or knitted and contained in the fiber reinforced resin material. The woven fabric may be a plain woven fabric, a twill woven fabric, a satin woven fabric, or the like. When the fiber is a short fiber, the fiber can be contained in the fiber reinforced resin material in a state like a non-woven fabric.

The fibers include glass fibers, carbon fibers, silicon carbide fibers, alumina fibers, tyranno fibers, genbuiwa fibers, stainless fibers, steel fibers and other inorganic fibers; aramid fibers, polyethylene fibers, polyester fibers, polyparaphenylene benzoxador (PBO). ) Organic fibers such as fibers; examples include boron fibers. The fibers may be used alone or in combination of two or more.

The resin constituting the fiber reinforced resin layer 20 together with the fibers contains an epoxy resin as a main component. The epoxy resin is preferably 70% by mass or more, more preferably 85% by mass or more, and may be 100% with respect to the total mass of the resins constituting the fiber reinforced resin layer 20.
The epoxy resin is a polymer or copolymer of epoxy compounds having a linear structure, or a copolymer of an epoxy compound and a monomer capable of polymerizing with the epoxy compound. Examples thereof include copolymers having a chain structure. Specifically, examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol fluorene type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, cyclic aliphatic type epoxy resin, and long chain aliphatic type epoxy resin. , Glysidyl ester type epoxy resin, glycidyl amine type epoxy resin and the like. As the epoxy resin, a bisphenol A type epoxy resin and a bisphenol fluorene type epoxy resin are preferable.

The fiber reinforced resin layer 20 may contain a resin other than the epoxy resin as a subcomponent of the resin. The resin other than the epoxy resin is preferably 30% by mass or less, more preferably 15% by mass or less, and 0% by mass, based on the total mass of the resins constituting the fiber reinforced resin layer 20. May be good.
The resin other than the epoxy resin may be a thermosetting resin or a thermoplastic resin. As the thermosetting resin, for example, unsaturated polyester resin, phenol resin, melamine resin, polyurethane resin, silicon resin, maleimide resin, vinyl ester resin, cyanate ester resin, maleimide resin and cyanate ester resin are prepolymerized. Examples include resin. Examples of the thermoplastic resin include an olefin resin, a polyester resin, a thermoplastic epoxy resin, an amide resin, a thermoplastic polyurethane resin, a sulfide resin, an acrylic resin and the like.

The fiber reinforced resin layer 20 is usually formed to have a thickness of 0.1 mm to 5 mm. Further, the fiber reinforced resin layer 20 is usually formed so as to contain fibers in a proportion of 10% by mass or more and 90% by mass or less. In addition to the above resins and fibers, various additives may be used to form the fiber reinforced resin layer 20.

By the way, the present inventor infers the reason why the resin composite 1 according to the present embodiment has excellent compression resistance in a high temperature environment in addition to peeling resistance as follows. ..

That is, as described above, in the resin composite 1, the core material 10 contains a polycarbonate-based resin as the main component of the resin, and the fiber-reinforced resin layer 20 contains an epoxy resin as the main component of the resin.
Here, since the polycarbonate resin and the epoxy resin have a relatively high thermal deformation temperature, the core material 10 containing the polycarbonate resin as the main component of the resin and the fiber reinforced resin layer 20 containing the epoxy resin as the main component of the resin are used. It is considered that even at a high temperature (for example, 120 ° C.), deformation during compression is relatively unlikely to occur, that is, the compression resistance is relatively high.
Further, the polycarbonate resin is generally obtained from bisphenol A and phosgene (or phenyl carbonate) as raw materials.
Since it is considered that the structural portion derived from bisphenol A contained in the polycarbonate resin and the epoxy resin have high affinity as a compound, the fiber reinforced resin layer 20 is arranged so as to cover the outer surface of the core material 10. Then, it is considered that the adhesion between the outer surface of the core material 10 and the fiber reinforced resin layer 20 becomes relatively high. As a result, it is considered that the peel resistance between the outer surface of the core material 10 and the fiber reinforced resin layer 20 is relatively high.
From the above, it is considered that the resin composite 1 according to the present embodiment has excellent compression resistance in a high temperature environment in addition to peeling resistance.

In the resin composite 1, for example, the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b are arranged in this order on each of the two outer surfaces of the bead foams previously prepared as the core material 10 facing each other. The preformed body manufacturing step for producing the preformed body and the preformed body that has been heated are pressed with a molding die to integrate the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b. Further, it can be produced by performing a pressing step of integrating the first fiber reinforced resin layer 20a and the bead foam.

In the preformed body manufacturing step, when the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b are arranged in this order on each of the two outer surfaces of the bead foam facing each other, the outside of the bead foam It is preferable that the surface and the first fiber reinforced resin layer 20a are temporarily adhered, and the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b are temporarily adhered.
Temporary adhesion between the outer surface of the bead foam and the first fiber reinforced resin layer 20a can be performed by a resin impregnated in the fiber reinforced resin material constituting the first fiber reinforced resin layer 20a, and the first fiber reinforced resin layer 20a can be temporarily bonded. Temporary bonding between the resin layer 20a and the second fiber-reinforced resin layer 20b is performed by impregnating the fiber-reinforced resin material constituting the first fiber-reinforced resin layer 20a with the resin and the fiber-reinforced resin layer 20b constituting the second fiber-reinforced resin layer 20b. This can be done with at least one of the resins impregnated in the resin material.

In the pressing step, for example, a male and female mold can be used as a molding die for pressing the preformed body. When a male and female mold is used as the molding mold, a mold release film made of synthetic resin is formed on the outer surface of the second fiber reinforced resin layer 20b of the premolded product in order to improve the mold releasability from the male and female mold. It may be laminated.
The synthetic resin constituting the release film is not particularly limited as long as it has releasability to the second fiber reinforced resin layer 20b and the male and female molds, and is not particularly limited, for example, a tetrafluoroethylene-ethylene copolymer. Examples thereof include fluororesins such as (tetrafluoroethylene-ethylene copolymer), polystyrene-based resins, and polyester-based resins.

In the premolded product manufacturing step, for example, a flat bead foam (core material 10) and a sheet-shaped first fiber-reinforced resin layer 20a and a second fiber-reinforced resin layer 20b having a width narrower than that of the bead foam. Two sets of the above are prepared, and one set of the first fiber reinforced resin layer 20a and one set of the second fiber reinforced resin layer 20b are arranged in this order on each of the two outer surfaces of the flat bead foam facing each other, and the width thereof is increased. A preformed body in which the bead foam extends outward from the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b at both ends in the direction is produced, and the pressing step is performed on the preformed body. It is preferable to carry out the operation in a state where at least one end of the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b is not gripped while gripping the end portion in the width direction of the bead foam.

By not gripping at least one end of the first fiber-reinforced resin layer 20a and the second fiber-reinforced resin layer 20b in this way, the first fiber-reinforced resin layer 20a is placed on the bead foam when the preformed body is pressed. And the second fiber reinforced resin layer 20b is made movable, and the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b are separated from the bead foam (so as not to follow the movement of the bead foam). Since the male and female dies can be smoothly press-molded, the first fiber-reinforced resin layer 20a and the second fiber-reinforced resin layer 20b, which are generally difficult to press-mold, can be easily and accurately pressed on the preformed body. Can be press-molded.

In the pressing step, the preformed body is heated to soften the resin impregnated in the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b.
When the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b contain an uncured thermosetting resin, the uncured thermosetting resin is softened and has fluidity without being cured. It is preferable to do so.
Since the thermosetting resin is in a state of having fluidity before being heat-cured by heating, the temperature is controlled so as to maintain this state of having fluidity.
When the first fiber reinforced resin layer 20a and the second fiber reinforced resin layer 20b contain a thermoplastic resin, the temperature is controlled so that the thermoplastic resin has fluidity.
As the heating means for the preformed body, various known heating devices such as an infrared heater can be used.

The resin composite 1 thus obtained is excellent in compression resistance in a high temperature environment in addition to peeling resistance. Therefore, it can be used in a wide range of applications such as transportation equipment fields such as automobiles, aircrafts, railroad vehicles, and ships, home appliances fields, and information terminal fields.
For example, the resin composite 1 is suitable for use as a material for constituting automobile parts, which are required to have peel resistance and compressibility in a high temperature environment. Specifically, the resin composite 1 is suitable for use as a material for forming a front-end module base material, a floor panel, a bonnet, an undercover, and the like.

As described above, the bead foam can be obtained from a resin composition containing a polycarbonate-based resin as a main component (hereinafter, also referred to as a polycarbonate-based resin composition).
For the bead foam, a step of producing effervescent particles in which the raw grains contain a foaming agent to produce effervescent particles, and the produced effervescent particles are heated and pre-foamed (primary effervescent) to produce pre-expanded particles. Pre-foaming step, internal pressure applying step of impregnating pre-foamed particles with gas to apply secondary foaming force, and secondary foaming of pre-foamed particles to which internal pressure is applied in the molding mold to form a cavity (molding space) ), It can be produced by carrying out a molding process for producing a molded product (bead foam) having a shape corresponding to).

The shape of the resin particles is not particularly limited. For example, spherical shape, columnar shape and the like can be mentioned. Of these, it is preferable that it is as close to a spherical shape as possible. That is, it is preferable that the ratio L / D of the minor axis D and the major axis L of the resin particles is as close to 1 as possible. L and D are preferably in the range of 0.5 to 10 mm. The average particle size is preferably in the range of 0.5 to 10 mm.
The method for producing the resin particles is not particularly limited, and for example, the base resin is supplied to an extruder and melt-kneaded, and the obtained strands are cut in air, cut in water, and cut while heating. Then, there is a method of granulating.

Foamable particles can be obtained by impregnating the resin particles obtained above with a foaming agent.
As the foaming agent impregnated in the resin particles, a known volatile foaming agent or inorganic foaming agent can be used. Examples of the volatile foaming agent include aliphatic hydrocarbons such as propane, butane, and pentane, aromatic hydrocarbons, alicyclic hydrocarbons, and aliphatic alcohols. Examples of the inorganic foaming agent include carbon dioxide gas, nitrogen gas, air (air), and an inert gas (helium, argon, etc.). Two or more of these foaming agents may be used in combination. Of these foaming agents, inorganic foaming agents are preferable, and carbon dioxide gas is more preferable.
The content (impregnation amount) of the foaming agent is preferably 3 to 15 parts by mass with respect to 100 parts by mass of the polycarbonate resin composition. When the content of the foaming agent is 3 to 15 parts by mass, the foaming power becomes relatively high and foaming becomes relatively good, and in addition, the plasticizing effect becomes relatively small and shrinkage occurs during foaming. It is relatively unlikely to occur, the productivity is improved, and it becomes easy to stably obtain the desired bulk density. A more preferable content of the foaming agent is 4 to 12 parts by mass.

As an impregnation method, a wet impregnation method in which resin particles are dispersed in an aqueous system and impregnated by press-fitting a foaming agent while stirring, or a practical impregnation method in which resin particles are put into a sealable container and the foaming agent is press-fitted to impregnate. Examples include a dry impregnation method (gas phase impregnation method) that does not use water. In particular, a dry impregnation method that can impregnate without using water is preferable. The impregnation pressure, impregnation time, and impregnation temperature when impregnating the resin particles by the dry impregnation method with the foaming agent are not particularly limited, but from the viewpoint of efficiently impregnating the resin particles and obtaining even better prefoamed particles and foamed molded product. The impregnation pressure is preferably 0.5 to 10 MPa (gauge pressure). It is more preferably 1 to 4.5 MPa (gauge pressure).

The impregnation time is preferably 0.5 to 200 hours. When the impregnation time is 0.5 to 200 hours, the amount of the foaming agent impregnated into the resin particles is relatively high, so that sufficient foaming power can be easily obtained and the productivity is relatively high. be able to. A more preferable impregnation time is 1 to 100 hours.
The impregnation temperature is preferably 0 to 60 ° C. When the impregnation temperature is 0 to 60 ° C., it is possible to suppress the solubility of the foaming agent in the resin from being excessively increased and excessively decreased, so that the foaming agent is prevented from being impregnated more than necessary. However, it is possible to suppress a decrease in the impregnation amount of the foaming agent. Further, since it is possible to prevent the diffusivity of the foaming agent in the resin from being excessively lowered and excessively increased, it becomes easy to obtain sufficient foaming power (primary foaming power) within a desired time. A more preferable impregnation temperature is 5 to 50 ° C.

A surface treatment agent such as a bond inhibitor, an antistatic agent, and a spreading agent may be added to the effervescent particles.
The binding inhibitor (coupling inhibitor) plays a role of preventing coalescence of the prefoamed particles in the prefoaming step. Here, coalescence means that a plurality of foamed particles are united and integrated. Examples of the bond inhibitor include inorganic powders such as talc, calcium carbonate and aluminum hydroxide, and organic powders such as fatty acid metal salts and fatty acid esters such as zinc stearate, magnesium stearate and ethylene bisstearic acid amide. Can be mentioned. The amount of the bond inhibitor added is preferably 0.01 to 1.0 parts by mass with respect to 100 parts by mass of the foamable particles.
Examples of the antistatic agent include polyoxyethylene alkylphenol ether and stearic acid monoglyceride.
Examples of the spreading agent include polybutene, polyethylene glycol, silicone oil and the like.

As a method of foaming the foamable particles to obtain pre-foamed particles, there is a method of heating the foamable particles with hot air, a heat medium such as oil, steam (steam), or the like to foam them. Steam is preferable for stable production.
It is preferable to use a closed pressure-resistant foam container for the foaming machine during pre-foaming. The steam pressure is preferably 0.10 to 0.80 MPa (gauge pressure), more preferably 0.25 to 0.45 MPa (gauge pressure). The foaming time may be any time required to obtain the desired bulk density. The preferred foaming time is 3 to 180 seconds. When it is 180 seconds or less, it is possible to suppress the start of shrinkage of the pre-foamed particles, so that the bead foam obtained from such pre-foamed particles has good physical properties.
The anti-coupling agent may be removed before molding. As a removal method, it can be washed with an acidic aqueous solution such as water or hydrochloric acid.

The prefoamed particles are filled with the prefoamed particles in a pressure vessel so as to have a predetermined internal pressure applied amount according to the molding vapor pressure so as to satisfy the above formula, and a foaming agent is press-fitted into the pressure vessel to apply the internal pressure.
As the foaming agent used for applying the internal pressure, the foaming agent used in the production of the preliminary foamed particles can be used. Among them, it is preferable to use an inorganic foaming agent. In particular, it is preferable to use one of nitrogen gas, air and carbon dioxide gas, or to use two or more in combination.
The pressure for applying the internal pressure is preferably in a range in which the required amount of internal pressure applied can be obtained, but if the pressure is high, the prefoamed particles may be crushed. In such a case, the pressure can be gradually increased to equalize the pressure inside the prefoamed particles and the pressure vessel, and then gradually increased to suppress the crushing of the prefoamed particles. Specifically, the internal pressure applied pressure can be 0.1 to 4 MPa (gauge pressure).
Although no further detailed description will be repeated here, the bead foam and the resin composite 1 are not limited to the above examples.

The resin composite according to the present invention is not limited to the above embodiment. Further, the resin composite according to the present invention is not limited by the above-mentioned action and effect. The resin composite according to the present invention can be variously modified without departing from the gist of the present invention.

Next, the present invention will be described in more detail with reference to examples. The following examples are for explaining the present invention in more detail, and do not limit the scope of the present invention.

[Example 1]
(Molding of bead foam)
Polycarbonate resin pelleted to a size of φ1.0 mm in diameter × 1.1 mm in length using an extruder (SABIC Innovative Plastics, Lexan® 153; hereinafter also referred to as PC) 2 kg of a pressure-resistant container of 10 L Contained inside.
Carbon dioxide gas was press-fitted into the pressure-resistant container, and the pellet was left to stand for 24 hours in an environment of 20 ° C. in a state of being pressurized to a pressure of 2.8 MPa (gauge pressure), and the pellets were impregnated with carbon dioxide gas to obtain effervescent particles.
Next, after decompressing the inside of the pressure vessel, the effervescent particles are taken out, 0.5 parts by mass of calcium carbonate is dry-blended as an anti-cohesion agent, and then heated with high-pressure steam of 0.34 MPa (gauge pressure) for about 13 seconds. Pre-foamed by doing. At this time, the amount of carbon dioxide impregnated into the effervescent particles immediately after being taken out from the pressure vessel was 6.6% by mass, and the bulk density of the prefoamed particles was 0.15 g / cm ³ .
Next, using dilute hydrochloric acid water, the obtained prefoamed particles were washed and removed from the calcium carbonate adhering to the surface and dried. After that, about 700 g of prefoamed particles were housed in a 10 L pressure-resistant container, and nitrogen gas was pressurized and filled until it reached 1.5 MPa (gauge pressure). It was left as it was at room temperature for 24 hours, and internal pressure was applied to the preliminary foamed particles.
Next, the pressure inside the pressure-resistant container was decompressed. After decompression, the prefoamed particles to which the internal pressure was applied in the pressure-resistant container were taken out. Using a high-pressure molding machine equipped with a molding mold of 300 mm × 400 mm × 30 mm, the pre-foamed particles are filled in the mold with 3 mm of mold cracking, and then 0.3 MPa ( High-pressure steam of 0.8 MPa (gauge pressure) was introduced for 3 seconds and exhausted, and then high-pressure steam of 0.8 MPa (gauge pressure) was introduced for 20 seconds for molding to obtain bead foam. At this time, the amount of internal pressure applied was 5% by mass. The thickness of the obtained bead foam was 29.94 mm. The thickness of the bead foam was the average value of the thickness measured at 5 points using "Digimatic Caliper" manufactured by Mitutoyo Co., Ltd., avoiding irregularities such as steam slit marks formed on the surface of the obtained bead foam. ..
Further, the internal bubble pressure (Pm) at the time of molding = 1.22 MPa> molding vapor pressure (Ps) = 0.9 MPa (absolute pressure).
Next, the obtained bead foam was dried in an oven at 60 ° C. for 24 hours, and then the air permeation resistance was measured. As a result, the average air permeation resistance was 69.72 s.

(Molding of resin composite)
A plate-shaped sample having a thickness of 30 mm and a size of 150 mm × 150 mm was cut out from the bead foam and used as a core material. 20 carbon FRP prepregs (trade name "UD prepreg TR395G100S" manufactured by Mitsubishi Rayon Co., Ltd., hereinafter also simply referred to as CFRP) cut into 150 mm x 150 mm and glass FRP prepregs (trade name "EGP-87 LA18BR" manufactured by Nippon Rika Co., Ltd.) Two sheets (hereinafter, also simply referred to as GFRP) were prepared, and after stacking 10 CRFPs so that the outer peripheral edges were aligned on the upper surface side of the core material, one GFRP was stacked on the outermost surface of the CRFPs. .. Similarly, after stacking 10 CRFPs on the lower surface side of the core material, one GFRP was stacked on the outermost surface of the CRFPs to prepare a preformed body. In addition, each prepreg contained an epoxy resin as a resin. The configurations of CRFP and GFRP are as shown in Table 1 below. This preformed body is pressed with a male and female mold under a heated state, and 10 CFRP (first fiber reinforced plastic layer) and one GFRP (second fiber reinforced resin layer) are placed on the upper and lower surfaces of the core material. A resin composite in which a fiber-reinforced resin layer made of the above was formed was produced. Specifically, in the male and female dies, the preformed body is pressed and heated at a temperature of 100 to 110 ° C. for 20 minutes to completely cure the epoxy resin in CFRP and the epoxy resin in GFRP (curing). Step) to prepare a resin composite.
As a result of measuring the thickness of the resin composite, the residual thickness of the core material after the production of the resin composite was 89.2% as compared with the thickness of the original core material. The thickness of the resin composite was determined by sandwiching both sides with smooth metal plates of 200 mm × 200 mm and measuring the gap between the metal plates. The gap between the metal plates was measured with an accuracy of 1/100 mm at the center of the four sides of the resin composite using a "Digimatic Caliper" manufactured by Mitutoyo, and the arithmetic mean of the four side gaps was taken as the thickness of the composite. Further, the thickness of the fiber-reinforced resin layer is set to 1.00 mm, the value subtracted from the thickness of the resin composite is used as the thickness of the core material after the resin composite is manufactured, and the thickness of the core material is divided by the original thickness of the core material. The survival rate was used.

[Comparative Example 1]
Polycarbonate resin is a styrene-methyl methacrylate-maleic anhydride copolymer. Hereinafter, the resin composite according to Comparative Example 1 was produced in the same manner as in Example 1 except that it was simply referred to as SMM).

[Comparative Example 2]
A resin composite according to Comparative Example 2 was produced in the same manner as in Example 1 except that the polycarbonate resin was a polyethylene terephthalate resin (hereinafter, also simply referred to as PET).
The composition of the resin composite according to each example is shown in Table 2 below.

Table 3 below shows various physical properties of the resin composite according to each example. The methods for measuring various physical properties shown in Table 3 below are described below.

(Density of bead foam and resin composite)
The density (apparent density) of the beaded foam was measured according to JIS K7222: 2005 "Foam plastics and rubber-How to determine the apparent density".
The density (apparent density) of the resin composite (hereinafter, also referred to as a molded product) was measured according to JIS K7222: 2005 “Foam Plastic and Rubber-How to Obtain the Apparent Density”. That is, the density of the resin composite was obtained by dividing the total mass of the resin composite by the apparent volume of the resin composite.

(Compressive strength of resin composite)
Measured by the method described in JIS K6767: 1999 "Foam plastic-polyethylene-test method". That is, using the "Tensilon UCT-10T" universal tester manufactured by Orientec and the "UTPS-458X" universal tester data processing manufactured by Softbrain, a test piece having a size of 50 mm in length × 50 mm in width × 26 mm in thickness was formed. The measurement was performed under the condition of a compression speed of 13 mm / min. The compression strength was measured at 5%, 10%, 25% and 50% of the thickness when compressed. The number of test specimens was three. In addition, after adjusting the state of the test piece under the JIS K 7100: 1999 symbol "23/50" (temperature 23 ° C., relative humidity 50%) for 24 hours or more under a second-class standard atmosphere, the same standard atmosphere. The measurement was performed below and in a high temperature environment atmosphere. When measuring the compression strength in a high-temperature environment, the test piece is left at a temperature of 23 ° C. and a relative humidity of 50% for 24 hours or more, and then measured in a constant temperature bath attached to the device at 120 ° C. (n). ) I put in a minute. This was left to stand for 20 minutes and then set in the testing machine, and the test was performed 3 minutes later (for the measurement after n = 2, the next test piece was immediately set in the testing machine after the end of the immediately preceding measurement and 3 minutes. I did the test later). The compression strength was calculated with the origin of displacement as the regression point.
(Compression strength)
The compression strength σm (kPa) was calculated by the following formula.
・ Σm = 103 × Fm / A0
Fm is the maximum force (N) reached when the deformation rate is m%, and A0 is the initial cross section (mm ² ) of the test piece.

(Peeling strength of resin composite)
When laminating the first and second fiber reinforced plastic layers (CFRP and GFRP) when preparing the resin composite, an edge is formed between the first fiber reinforced resin layer (CFRP) and the core material due to the introduction of initial cracks. One polyolefin-based film was inserted so as to be perpendicular to the fiber arrangement direction (90 ° ± 1 °) to provide film cracks. The crack length of the film was 40 to 45 mm, and the total thickness of the film to be inserted was 30 μm or less. A flat rectangular test piece measuring 150 mm in length and 25 mm in width was cut out from the resin composite. The number of test specimens was five. By opening the film insertion portion with a sharp blade such as a knife, a pre-crack of 2 mm to 5 mm was introduced to obtain an initial crack. Use the jig (A) to grasp the end where the initial crack is introduced in the fiber reinforced resin layer and the core material, and use the jig (B) to grasp the end where the initial crack is not introduced. I grasped it. The jigs (A) and (B) are moved along the surface direction of the fiber reinforced resin layer in a direction away from each other at a test speed of 2 mm / min to pull the test piece, and the maximum peel strength measured in this process is obtained. The peel strength was determined by measuring and calculating the average value of the number of tests.

From Table 3, it was found that the resin composite (molded product) according to Comparative Example 1 was excellent in compressive strength (compressibility) in a high temperature environment, but inferior in peel strength.
Further, it was found that the resin composite (molded product) according to Comparative Example 2 was excellent in peel strength, but inferior in compressive strength (compressibility) in a high temperature environment.
On the other hand, it was found that the resin composite (molded product) according to Example 1 was excellent in both peeling resistance and compressive strength (compressibility) in a high temperature environment.
From this, the core material is prepared from the resin containing the polycarbonate resin, the fiber reinforced resin layer is prepared from the resin containing the epoxy resin, and the fiber reinforced resin layer is arranged so as to cover the outer surface of the core material. Therefore, it was found that a resin composite having excellent peeling resistance and compression resistance in a high temperature environment can be obtained.

1 resin composite, 10 cores, 20 fiber reinforced resin layer, 20a first fiber reinforced resin layer, 20b second fiber reinforced resin layer.

Claims (1)

A resin core material and a fiber reinforced resin layer covering the outer surface of the core material are provided.
The core material contains a polycarbonate resin and contains
The fiber-reinforced resin layer is a resin composite containing an epoxy resin.