GB2290045A

GB2290045A - Deformed fiber reinforced plastic

Info

Publication number: GB2290045A
Application number: GB9510762A
Authority: GB
Inventors: Keiko Tanaka; Morihiko Sugino; Tomokazu Nakagawa
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 1994-05-26
Filing date: 1995-05-26
Publication date: 1995-12-13
Also published as: GB9510762D0; DE19519241C2; DE19519241A1

Description

2290045 DEFORMED FIBER REINFORCED PLASTIC The present invention relates to

a deformed fiber reinforced plastic, and specifically to a deformed fiber reinforced plastic containing carbon fibers as a reinforcing material in a matrix made of thermosetting resin (hereinafter, referred to as Meformed CFRP"). In particular, the present invention concerns a deformed URP suitable as a housing material for electronic equipment and electric equipment (hereinafteri referred to as "electronic equipment and the like") such as notetype personal computers, CD players, and headphone stereos.

Housing members for electronic equipment and the like have been formed of pressed metal products; however, recently, due to a desire for machinability and lightweightness, they are now made of plastics, for example. deformed CFRPs. In particular, it is strongly desired that portable electronic equipment such as notetype personal computers are reduced in size and weight, and to meet such a requirement.

deformed URPs have been practically used for housings of the portable electronic equipment.

The deformed MP and its manufacturing method are disclosed, for example in Examined Japanese Patent Publication No. HEI 5-58371. The deformed URP disclosed in this reference (hereinafter, referred to as "prior art deformed URP") is characterized in that carbon'fibers having fiber lengths ranging from 10 to 100 mm are two-dimensionally and irregularly distributed in a matrix made of thermosetting resin as a reinforcing material, and the thickness of a flat plate portion is 1 mm or less. With this construction, particularly, with the two-dimensional and irregular distribution of carbon fibers having the fiber lengths ranging from 10 to 100 mm. the deformed URP exhibits excellent and uniform mechanical properties such as a tensile strength and elastic modulus.

The prior art deformed URP is manufactured by a method wherein unwoven fabric made of carbon fibers having a tensile strength of 300 kgf/mm2 (2942 MPa) or more is impregnated with thermosetting resin and is dried, to form a prepreg; and these prepregs are placed between forming dies having a specified deformed cavity and are hot-pressed at a pressure of 100 kgf/CM2 (9.8 - 2 1 1 f-L MPa) or more for allowing the thermosetting resin and carbon fibers in the prepregs to flow in the cavity, to thereby form prepregs in a deformed URP. With this construction, particularly, with the flow of carbon fibers together with thermosetting resinr carbon fibers are uniformly distributed in a matrix, so that the deformed URP exhibits excellent and uniform mechanical properties such as a tensile strength and elastic modulus.

Since the prior art deformed URP has the excellent and uniform mechanical properties such as a tensile strength and elastic modulus as described above, they are effective to reduce the weight of housing members of electronic equipment and the like, and hence to reduce the weight of the electronic equipment and the like.

The prior art deformed MP, however, has disadvantages in that the cai;bon fibers present on and near the surface are visible to the naked eye, and thereby the appearance is poor; in the case where the deformed URP is thin, for exampler it has a thickness of 1 mm or less, the surface rolling is generated on the surface because of the waviness of the carbon fibers and therefore the shaping accuracy and the appearance are poor; and in the case where the deformed CMP has a projecting deformed portion such as a boss or rib, a shrinkage-like recessed portion is generated on the back surface side of the deformed portion and therefore the appearance is poor.

Incidentally. in the field of electronic equipment and the like, there is a tendency toward compactness and high capacity. With this tendencyr the amount of heat generated from electronic circuits and electric circuits (hereinafter, referred to as "electronic circuits") and the electronic parts and electric parts (hereinafter, referred to as "electronic parts") is liable to be significantly increased, and further the heat thus generated has difficulty escaping, increasing the temperature of the equipment. As a consequence, the reliability of the electronic parts and the equipment is reduced. Alternativelyr the temperature of a housing (case) is locally increased due to the heat from the electronic parts, which possibly causes problems such as low temperature heat injury when the housing is contacted with the body of a user, thus giving discomfort to the user. For this reason, the prior art MP has a limitation in making compact electronic equipment and the like and in increasing the capacities thereof.

On the other hand, with respect to the waste disposal of fiber reinforced plastics such as deformed URPs. the waste disposal technique has not been established, and accordingly, at present, the waste tends to be reclamated or simply burned. However, from considering the serious environmental problems and ef f ective use of a resource, f iber reinforced plastics are required to be recycled.

In view of the foregoingy the present invention has solved the above-described problems of the prior art deformed URP. Accordingly, an object of the present invention is to provide a deformed fiber reinforced plastic capable of ensuring excellent mechanical properties comparative to those of the prior art deformed URP; improving the appearance by eliminating the generation of surface rolling even for a improving the shaping accuracy and appearance by eliminating generation of surface rolling even for a thin product having a thickness of 1 mm or less; and improving the appearance by eliminating a shrinkage-like recessed portion even for a deformed product having a projecting deformed portion such as a boss or rib.

rIA Another object of the present invention is to provide a deformed fiber reinforced plastic having the above-described characteristicsi which furthermore. has improved thermal conductivity for suppressing a local temperature rise due to local heating and for allowing the heat to easily escape.

A further object of the present invention is to provide a deformed fiber reinforced plastic capable of effectively utilizing carbon fibers recovered by decomposition of carbon fiber reinforced plastics (recycled carbon fibers) thereby contributing to the use of fiber reinforced plastics in recycling.

To achieve the above object, a deformed fiber reinforced plastic (referred to as "deformed CFRP") of the present invention is constructed as follows.

Accordingly, the present invention provides a deformed fiber reinforced plastic comprising:

a matrix made of thermosetting resin in which carbon fibers having fiber lengths ranging from 10 to 100 mm are two-dimensionally and irregularly distributed as a reinforcing material, and a flat plate portion having a thickness of 1 mm or less, wherein the outer surface of the flat plate portion has an irregular pattern transferred from a die, and the surface layer of each projecting portion of the irregular pattern is substantially made of resin.

Accordingly, a preferred embodiment of the present invention provides a deformed fiber reinforced plastic as described hereinbefore, wherein the pitch of the irregular pattern is 5 mm or less and the height thereof is 10 um or more.

Accordinglyr a preferred embodiment of the present invention, provides a deformed fiber reinforced piastic comprising:

a matrix made of thermosetting resin in which carbon fibers having fiber lengths ranging from 10 to 100 mm are two-dimensionally and irregularly distributed as a reinforcing material, and a flat plate portion having a thickness of 1 mm or lessi, wherein the surface layer of the deformed fiberreinforced plastic is integrated with a metal thin plate by pressing, which is preferably provided with a deformed fiber reinforced plastic - 7 wherein the thickness of the metal thin plate is 0.5 mm or less. According to this embodiment of the present invention it is preferred that there is provided a deformed fiber reinforced plastic wherein the metal thin plate is made of Al, Al alloy, Cu or Cu alloy.

Accordingly. a preferred embodiment of the present invention provides a deformed fiber reinforced plastic as described hereinbefore, wherein the metal thin plate has slit-like voids; the total area of the voids is 500 mm2 or less, and a porosity, that is. the area ratio of the voids to the metal thin plate is 50% or less.

Accordingly, a further preferred embodiment of the present invention provides a deformed fiber reinforced plastic as described hereinbefore wherein part or all of the carbon fibers comprise recycle carbon fibers recovered by thermal decomposition of carbon fiber reinforced plastics as a raw material.

Accordingly. a preferred embodiment of the present invention provides a deformed fiber reinforced plastic comprising:

r"ll a matrix made of thermosetting resin in which carbon fibers are distributed as a reinforcing material, wherein part or all of the carbon fibers comprise recycle carbon fibers recovered by thermal decomposition of carbon fiber reinforced plastics as a raw material, wherein preferably, the mixing ratio of the recycled carbon fibers based on the weight of the total carbon fibers is in the range from 5 to 100 wt%. Accordingly. it is preferred that deformed fiber reinforced plastic is provided, wherein the fiber lengths of the recycle carbon fibers in the carbon fiber reinforced plastic as the raw material in the state before thermal decomposition is in the range from 10 to 100 mm. it is additionally preferred that there is provided a deformed fiber reinforced plastic wherein the amount of resin carbonate in the recycle carbon fibers is in the range from 0 to 60 wt%.

According to a preferred embodiment of the present invention there is provided a deformed fiber reinforced plastic as described hereinbefore wherein the thermosetting resin contains phenol resin in an amount of 30 wt% or more.

According to a further preferred embodiment of the present invention there is provided a deformed fiber reinforced plastic as described hereinbefore wherein the f iber lengths of the carbon f ibers is in the range from 20 to 30 mm, wherein, preferably, the volume ratio of the carbon f ibers to the matrix is in the range from 15 to 35%.

According to a preferred embodiment of the present invention there is provided a deformed f iber reinforced plastic as described hereinbefore wherein the bending strength is 147 MPa or more, the bending elastic modulus is 12 GPa or more, and the Izod impact value of 98 i/m or more.

According to a preferred embodiment of the present invention there is provided a deformed f!her reinforced plastic as described hereinbefore 10 wherein the plastic is formed in a deformed integral body having a flat plate portion and a projecting deformed portion, and carbon fibers at the root portion of the deformed portion are oriented in the direction of joining the flat plate portion to the deformed portion.

The invention will now be described in more detail by reference to the accompanying drawings.

Fig. 1 is a schematic sectional side view showing the formation of lower and upper dies according to Examples 1 to 3; Fig. 2 is a schematic sectional side view showing the forming state of a deformed URP according to Examples 1 to 3; Fig. 3 is a schematic perspective view showing a deformed URP according to Examples 1 to 2; Figs. 4(A) and 4(B) are front and side views for loading and fixing states upon fatigue testing of a liquid crystal display cover according to Example 3; Fig. 5 is a schematic view showing the breakage state upon fatigue test (load case 1) for the MP made liquid crystal display cover according to Example 3; Fig. 6 is a schematic view showing the breakage state upon fatigue test for an ABS URP made liquid crystal display cover; Fig. 7 is a schematic sectional side view showing the arrangement of a deformed MP forming material between forming dies according to Example 4; Fig. 8 is a schematic sectional side view showing the forming state of a deformed MP according to Example 4; Figs. 9(A) and 9(B) are schematic perspective views showing the deformed MP product according to Example 4r wherein Fig. 9(A) shows the outside of the productr and Fig. 9(B) shows the inside of the product; Fig. 10 is a schematic sectional side view showing a test of locally heating a product according to Example 5; Fig. 11 is a schematic sectional side view showing a test of locally heating a lower case of a note-type personal computer which is formed of a deformed MP according to Example 6; and Figs. 12(A) and 12(B) are schematic perspective views showing a deformed MP product according to Example 7y wherein Fig. 12(A) shows the outside of the product and Fig. 12(B) shows the inside of the product.

12 - 1 According to the invention as described above, a deformed fiber reinforced plastic includes a matrix made of thermosetting resin, in which carbon fibers having fiber lengths ranging from 10 to 100 mm are two-dimensionally and irregularly distributed as a reinforcing material, and a flat plate portion having a thickness of 1 mm or less, wherein the outer surface of the flat plate portion has an irregular pattern transferred from a dier and the surface layer of each projecting portion of the irregular pattern is substantially made only of resin. Eerei the wording "the surface layer of each projecting portion is substantially made of resin" does not mean that the carbon fibers are not perfectly contained but means that the long carbon fibers do not project outwardly from the resin matrix on the surface of the projecting portion. The outer surface side of the flat plate portion in the deformed URP is equivalent to the outer surface side of a flat plate portion of a deformed URP product used as a housing.

In the deformed URP of the invention, the outer surface of the flat plate portion (hereinafter, 0 1 referred to as "flat plate surface") has an irregular pattern transferred from a die, and carbon fibers are present on and near the surface of each recessed portion of the irregular pattern and which are difficult for the naked eye to see; while carbon fibers do not project outwardly from the resin matrix on the surface of each projecting portion (more visible to the naked eye) of the irregular patternf that isf carbon fibers are not substantially present on the surface layer of each projecting portion. Accordingly, in this deformed WRPf the irregular pattern is visible as a whole and carbon fibers are not visible to the naked eyer thus improving the appearance.

Moreover, since carbon fibers are not substantially present on the surface layer of each projecting portion, even in the case where the deformed C M is thin (thickness: 1 mm or less)f the surface rolling is not generated and thereby the appearance is improved. Specifically, the waviness of carbon fibers causing the surface rolling is generated upon formation of CEW due to a difference in the rate of shrinkage between the thermosetting resin constituting the matrix and carbon fibersf and consequently, it is not generated in the projecting portion because carbon fibers are not substantially present therein. Thust the deformed MP is difficult to wave as a whole, and thereby it is less susceptible to surface rollingy thus improving the shaping accuracy and the appearance.

In addition, since the flat plate surface has an irregular pattern and is poor in surface smoothness, even in the case where the deformed MP has a projecting deformed portion such as a boss or rib, a shrinkage-like recessed portion is softenedr and thereby the appearance is improved.

At the same time, in the deformed MP according to the invention, the construction in which carbon fibers having fiber lengths ranging from 10 to 100 mm are twodimensionally and irregularly distributed in a matrix made of thermosetting resin and a flat plate portion has a thickness of 1 mm or less, is the same as that in the prior art deformed MP. In other words, the construction except for the flat plate surface is the same as that in the prior art MP, and consequently, the deformed CFRP of the present invention has excellent mechanical properties similar to those in the prior art MP. The presence of the irregular pattern transferred to the flat plate surface from a die (carbon fibers are not substantially present on the surface of each projecting portion of the irregular pattern) does not harm or reduce the excellent mechanical properties of the deformed MP.

Accordingly, the deformed C M of the invention has excellent mechanical properties similar to those of the prior art deformed MP (described in Examined

Japanese Patent Publication No. REI 5-58371), and also it exhibits the following excellent characteristics:

namely, carbon fibers are not visible to the naked eye and therefore the appearance is improved; in the case where the deformed URP is thin (thickness: 1 mm or less)r the surface rolling is not generated and therefore the shaping accuracy and the appearance are improved; and in the case where the deformed MP has a projecting deformed portion such as a boss or rib, a shrinkage-like recessed portion is eliminated (or softened), thereby improving the appearance.

With respect to the fiber lengths of carbon fibers specified to be in the range from 10 to 100 mm, when it is less than 10 mm, the entanglement of carbon fibers is insufficient and the carbon fibers tend not to be uniformly distributed, thereby reducing the strength and elastic modulus; when it is more than 100 mm, the 1 carbon fibers are curled, thus reducing the strength and elastic modulus.

With respect to the irregular pattern, the pitch is preferably 5 mm or less and the height is preferably 10 pm or more. With this construction. it is ensured that carbon fibers are not substantially present on the surface layer of each projecting portion, and therefore the appearance is improved. When the pitch is more than 5 mm, or the height is less than 10 um, carbon fibers are slightly present on the surface layer of each projecting portion, tending to deteriorate the appearance. Heref the pitch of the irregular pattern means a distance between the vertexes of a projecting portion and the adjacent projecting portion. The height of the irregular pattern means a distance between the bottom and the vertex of a projecting portion, and it is equal to the height of a projecting portion relative to the bottom of a recessed portion and it is equal to the depth of the recessed portion relative to the vertex of the projecting portion.

As described above, in the deformed CrRP according to a preferred embodiment. carbon fibers having fiber lengths ranging from 10 to 100 mm are two-dimensionally and irregularly - 1 7 - distributed in a matrix made of thermosetting resin as a reinforcing material, and a metal thin plate is integrated with the surface layer of the deformed URP. Accordingly, as compared with the prior art deformed URP, heat conduct-ivity is improved by the presence of the metal thin plate, so that a local temperature rise due to local heating is reduced and the heat easily escapes.

In the prior art deformed URP, since URP is very inferior to metal in thermal conductivity (thermal conductivity is small), then when the deformed URP is locally heated. the heat has difficulty in being diffused along the surface of the URP plater so that the temperature of a locally heated portion is easier to increase, tending to increase the local temperature rise Moreover, the heat is transmitted in the thickness direction of the URP plate at the locally heated portion and escapes to the outside with the reached surface of the WRP plate taken as a radiation surface.

However, the area of the radiation surface is substantially equal to that of the locally heated portion, that is, it is small. As a result, the amount of radiation from the radiation surface is small and therefore the heat has great difficulty escaping.

On the contrary, in the deformed URP according to an embodiment of the invention which has a metal thin plate formed on the surface layer, since metal is very superior to URP in thermal conductivity (thermal conductivity is large). when the deformed URP is locally heated, the heat is diffused more easily along the surface of the metal thin plate. The temperature at the locally heated portion increases with more difficulty and therefore the local temperature rise is easier to reduce. The heat diffused along the surface of the metal thin plate is transmitted to a deformed CFRP portion, and escapes to the outside with the reached surface of the URP plate taken as the radiation surface. At this time, the area of the radiation surface is substantially equal to the surface area of the metal thin plate, that is, it is large. As a result, the amount of radiation from the radiation surface is large and therefore the heat escapes more easily.

In the deformed CFRP according to this embodiment of the invention the metal thin plate is integrated with the surface layer by pressing, even in the case where the deformed URP is thin (thickness: 1 mm or less), the surface rolling is not generated and therefore the shaping accuracy and the appearance are improved. in the prior art deformed WRP, the surface rolling is generated due to the waviness of carbon fibers caused by a difference in rate of contraction between the thermosetting resin constituting the matrix and carbon fibers upon formation of the WRP. However, in the deformed CPRP according to an embodiment of the invention since the surf ace layer is covered with the metal thin plate, the surface rolling is not generated. thus improving the shaping accuracy and the appearance.

Moreover, since the WRP is not exposed to the appearance by the presence of the metal thin plate formed on the surface layer. carbon fibers are not visible to the naked eyer thereby improving the appearance.

At the same time, in the deformed URP according to this embodiment, the CFRP portion as a base member formed with the metal thin plate is so constructed that carbon fibers having fiber lengths ranging from 10 to 100 mm are two-dimensionally and irregularly distributed in a matrix made of thermosetting resin as a reinforcing material. This construction is the same as that of the prior art deformed WRPr and thereby it exhibits excellent mechanical properties similar to those of the prior art deformed WRP. Moreover, since the metal thin

1 plate is thin, it does not harm or reduce the excellent mechanical properties.

Accordingly, the deformed URP has excellent mechanical properties comparative to those of the prior art deformed URP, and also it exhibits the following characteristics: namely, excellent thermal conductivity and therefore the local temperature rise due to local heating is small and the heat escapes more easily; carbon fibers are not visible to the naked eye and therefore the appearance is improved; and even in the case where the deformed URP is thin (thickness: 1 mm or less), surface rolling is not generatedp thereby enhancing shaping accuracy and appearance.

The reason why the fiber lengths of carbon fibers are specified to be in the range from 10 to 100 mm is the same as in the deformed URP described in claim 1.

The metal thin plate is preferably small in specific gravity in terms of lightweightness and is excellent in machinability. In this regard, the metal thin plate is preferably made of Al, Al alloy, Cu or Cu alloy. The surface of the metal thin plate may be subjected to surface treatment such as alumite treatment, plating or painting.

The thickness of the metal thin plate is preferably 0.5 mm or less. When it is more than 0.5 mm, the thickness of the URP portion is relatively thinned, thereby reducing the strength and obstructing the lightweightness. On the contraryr when it is 0.5 mm or lessr a high level of strength and lightweightness can be ensured. A different metal thin plate may be provided in the URPr in addition to the metal thin plate formed on the surface layer. In this case, the formability is reduced but the radiation characteristic is further improved.

Preferably, the metal thin plate has slit-like voids, wherein the total area of the voids 15 500 MM2 or less and the porosity. that is. the area ratio of the voids to the metal thin plate is 50% or less.

With this construction, it is possible to suppress the generation of a camber due to a difference in linear expansion coefficient between the metal thin plate and URP portion. The linear expansion coefficient is deDendent on the kinds of metals and CFRPs; however, in general, metal is significantly different from CFRP in their linear expansion coefficients. Accordingly, for the metal thin plate having no voids, the contraction of the metal thin plate is different 1 from that of the URP in a cooling process after heating upon manufacture (formation), and consequently, a formed product has a possibility in generating a camber. Alternatively, the formed product has a possibility in generating a camber by the effect of heat received during use. On the contrary, for the metal thin plate having slit-like voids, although metal is different from URP in linear expansion coefficient, the contraction of the metal thin plate is not different from (equal or nearly equal to) that of the URP in a cooling process after heating upon manufacture (formation). As a result, the above-described camber is difficult to generate or is suppressed at an extremely slight amount. At this time, as the porosity is increased, the degree of the camber can be reduced but the radiation characteristic tends to be lowered. Specifically, when the porosity is more than 50%, the radiation characteristic is largely reduced. The porosity is thus specified to be 50% or less. Moreover, the total area of the voids also exerts the effect similar to that of the porosity to the radiation characteristic. When the total area of the voids is more than 500 MM2, the radiation characteristic is largely reduced. The total - 23 area of the voids is thus specified to be 500 MM2 or less.

In the deformed CFRP of the present invention, part or all of carbon fibers can be replaced with recycled carbon f ibers recovered by thermal decomposition of carbon fiber reinforced plastics. In this case, the recycled carbon fibers can be used without any reduction in the characteristics of the deformed URP, thus contributing to the effective use of recycle carbon fibers.

The same is true for the deformed CMP characterized in that carbon fibers are distributed in a matrix made of thermosetting resin, wherein part or all of the carbon f ibers are replaced with recycled carbon fibers recovered by thermal decomposition of carbon fiber reinforced plastics. In this caser the recycled carbon fibers can be used without any reduction in the characteristics of the deformed CFRP, thus contributing to the effective use of recycled carbon fibers.

with regard to recycled carbon f ibers recovered by thermal decomposition of carbon fiber reinforced plastics, at the time when being recovered, they contain carbon fibers near mono-filaments, and are entangled with each other in a cottony shape. The carbon fibers are left as being entangled with each other even at the time when they are processed in nonwoven fabric and the nonwoven fabric is impregnated with thermosetting resin and dried to form a prepreg. Accordingly, when the prepregs are hot-pressed to form a deformed URP, the carbon fibers are entangled with each other, that is, they are uniformly present in the matrix made of thermosetting resin. Moreover, in the case where the recycled carbon fibers are mixed with common non-recycled carbon fibers (new carbon fibers)r the mixed carbon fibers are also uniformly present in the matrix made of thermosetting resin.

In the above-described deformed URP, therefore, carbon fibers (recycled carbon fibers or recycled carbon fibers mixed with new carbon fibers) are uniformly distributed in a matrix made of thermosetting resin as a reinforcing material. Thus, the deformed CFRP has various characteristics (tensile strength, elastic modulus and the like) similar to those of thedeformed WRP using only new carbon fibers as a reinforcing material. As a 1 - resultr recycled carbon fibers can be replaced with part or all of new carbon fibers without any reduction in the characteristics of the deformed URPr thus contributing to the effective use Of recycled carbon fibers.

The mixing ratio of recycled carbon f ibers to the total carbon fibers is not particularly limited. However, when it is less than 5%, the significance of using recycled carbon fibers becomes poor. On the other hand, when the mixing ratio becomes 100%, the deformed URP can obtain sufficient characteristics. Accordinglyr the mixing ratio is preferably in the range from 5 to 100%.

In the case of using the above-described recycled carbon fibersr the fiber lengths of the recycledcarbon fibers are dependent on those of carbon fibers contained in carbon fiber reinforced plastics before thermal decomposition, so that to obtain 10-100 mm of the fiber lengths of carbon fibers in a deformed URPr the fiber lengths of carbon fibers in carbon fiber reinforced plastics before thermal decomposition may be specified in the range from 10 to 100 mm.

The recycled carbon f lbers recovered by thermal decomposition of carbon fiber reinforced plastics often 26 1 contain resin carbonate. However, when the amount of the resin carbonate is 60% or less, the resin carbonate exerts no effect on the properties of carbon fibers. Accordingly, the resin carbonate may be contained in the recycle carbon fibers in an amount of 60% or less.

In the deformed URP of the present invention, the above-described thermosetting resin may include phenol resin, epoxy resin, polyimide resin and the mixture thereof, and preferably, it contains phenol resin in an amount of 30% or more.

The thermosetting resin containing 30% or more of phenol resin satisfies the mechanical properties necessary for the deformed C M, for examplef a bending strength: 147 MPa (15 kgf/mm2) or more, bending elastic modulus: 12 GPa (1200 kgf/MM2) or more and Izod impact value: 98 j/M (10 kgf.=/i:iit2) or =rep and also it satisfies the burning resistance necessary for the deformed MP.

The above-described fiber lengths of carbon fibers are more preferably in the range from 20 to 30 mm for ensuring a high strength and elastic modulus.

27 - The volume ratio of the carbon fibers to the matrix is preferably in the range from 15 to 35% for ensuring a high strength and elastic modulus. When it is less than 15%, the strength and elastic modulus are reduced; while when it is more than.35%, portions unfamiliar with matrix resin are generated, thereby reducing the strength.

The deformed URP of the present invention has excellent mechanical properties, for example, a bending strength: 147 MPa (15 kgf/MM2) or more, bending elastic modulus: 12 GPa (1200 kgf/mm2) or more and Izod impact value: 98 J/m (10 kgf-CM/=2) or morer which are dependent on the volume ratio of carbon fibers to the matrix and the kind of the thermosetting resin In the case where the deformed URP of the present invention has a flat plate portion and a projecting deformed portion, carbon fibers at the root portion of the projecting deformed portion are preferably oriented in the direction of joining the flat plate portion to the projecting deformed portion With this construction, the projecting deformed portion is excellent in strength and a - 28 9 difference in strength between the projecting deformed portion and the flat plate portion is made small.

The deformed URP of the invention can be manufactured as follows. Namely, nonwoven fabric made of carbon fibers is impregnated with thermosetting resin and dried to form a prepreg; the prepregs are placed in a forming die having a different cavity and an irregular pattern on the inner surface and are hot-pressed to allow the thermosetting resin and the carbon fibers in the prepregs to flow in the cavity, thus forming a deformed URP and transferring the irregular pattern on the surface of a flat plate portion from the forming die..

By specifying the irregular pattern on the inner surface of the forming die such that the pitch is 5 mm or less and the height is 10 am or more. deformed CFRP according to a further embodiment of the invention can he obtained.

A deformed MP according to a further embodiment can manufactured by placing a metal thin plate and the abovedescribed prepregs in the abovedescribed forming die, which are hot-pressed to allow the thermosetting resin and the carbon fibers in the prepregs to flow in the cavity, thus forming a deformed URP and integrally joining the metal thin plate on the surface layer of the deformed C. By coating the surface, contacted with the prepregs, of the metal thin plate with resin, it becomes possible to enhance the adhesiveness between the metal thin plate and the URP of the deformed MP. Epoxy resin is preferable for enhancing the adhesiveness.

In each of the above-described manufacturing methods, the tensile strength of the deformed MP can be increased up to 49 MPa (500 kgf/CM2) using carbon fibers having a tensile strength of 2450 MPa (300 kgf/MM2). When the forming pressure is less than 9.8 MPa, the flow of thermosetting resin and carbon fibers is made difficult. to reduce the uniformity of the distribution of carbon fibers in the matrix. which makes uneven the mechanical properties. Accordingly, the forming pressure is preferably 9. 8 MPa or more. When the forming temperature is less than 1400C, it takes 10 min or more to harden the resiny thereby reducing productivity. On the other hand, if it is more than 2200C, the hardening time is excessively shortened, thereby making it difficult to form the deformed CPRP. Accordingly, the forming temperature is preferably in the range from 140 to 2200C. Moreover, as compared with the case where a single prepreg is formed, by forming prepregs laminated in a forming die, the orientation of 1 carbon fibers is relaxedr thus equalizing the strength of a product.

The present invention will be more clearly understood with reference to the following examples: Example 1 Nonwoven fabric made of carbon fibers (fiber length: 25 mm, and tensile strength: 2942 MPa (300 kgf/mM2)) was impregnated with phenol resin (one kind of thermosetting resins) and heated/dried in a drying furnace for 10 min at 1200C, to form a prepreg 1 (thickness: 1.0 mm). Five pieces of the prepregs 1 were laminated on a lower die 3 as shown in Fig. 1. and an upper die 2 having an irregular pattern (pitch: 3 mm, and height: 30 pm) formed on the inner surface was put on the lower die 3 as shown in Fig. 2. Subsequently, the prepregs 1 were hot-pressed at a pressure of 39 MPa (400 kgf/Cm2) and at a temperature of 1500C, thus forming a deformed URP 4 with the surface of a flat plate portion transferred with the irregular pattern from the upper die 2. Specifically, the deformed URP 4 in this example has a shape shown in Fig. 3. The thickness of the flat plate portion of the deformed URP 4 was 0.7 mm. The volume ratio of the carbon fibers to the resin constituting the matrix was 25%. In Fig. 3, reference numeral 5 indicates a rib, and 6 is a boss portion.

The deformed URP 4 in this example was subjected to visual inspection and to cross-sectional observation. It was then subjected to the bending test and to the impact test using a bending test piece and an Izod impact test piece prepared by cutting the deformed URP 4. From the visual observation, it was revealed that the deformed WRP 4 has excellent appearance and surface properties. Specificallyr no carbon fiber is identified on the surface of the flat plate portion which has the irregular pattern transferred from the upper die; no surface rolling is generated on the surface of the flat portion; and no shrinkage-like recessed portion is identified at all. From the cross sectional observation, it was revealed that no internal defects such as cracks and cavities are recognized; and no carbon fibers are seen in eacb projecting portion of the irregular pattern transferred from the upper die (carbon fibers are substantially absent in. the surface layer of the projecting portion) and the projecting portion is substantially made of only resin. From the impact test and bending test, it was revealed that the deformed URP 4 exhibits an 1zod 32 - impact value of 291 J/m (29 kgf.cm/cm2), a bending elastic modulus of 16 GPa (1600 kgf/MM2), and a bending strength of 246 MPa (25 kgf/mm2), which are similar to those in a deformed URP 4 of Comparative Example 1A (one of the prior art deformed CFRPs) described later. Accordingly, the deformed URP in this example has the excellent mechanical properties comparative to those of the prior art deformed CM.

A deformed URP 4 according to Comparative Example 1A was prepared in the same manner as in Example 1 except that an upper die 2 having a smooth inner surface (without any irregular pattern) is used, that is, the irregular pattern is not transferred. The deformed URP 4 thus obtained was tested in the same manner as Example 1. As a result, carbon. f ibers were visually observed on the surface of the flat plate portion (the carbon fibers project outwardly from the resin matrix on the surface of each projecting portion); surface rolling was recognized; and shrinkage- like recessed portions were recognized. Howevert internal defects such as cracks and cavities were not recognized. The deformed URP exhibited mechanical properties, for example, Izod impact value: 250 J/m (26 kgfcm/cm2), bending elastic modulus: 15 GPa (1530 kgf/M2), and bending strength: 240 MPa (24.5 kgf/MM2).

In Example 1, the thickness of the prepreg 1 was changed and the number of the laminated prepregs 1 disposed on the lower die 3 (the thickness of the deformed URP 4 was made constant (0.7 mm)). As a result, as compared with the case where a thick prepreg was laminated, in the case where a plurality of thin prepregs were laminated, the random (irregular) distribution of carbon fibers was ensured, and it was increased nearly with the number of the prepregs. Next, the pitch and the height of the irregular pattern on the inner surface of the upper die 2 were changed. As a result, as the pitch was made smaller and the height was made larger, the carbon fibers become difficult to be visual on the surface of the flat portion having the irregular pattern transferred from the upper die. ExamDle 2 Chops of carbon fibers (fiber length: 20 to 30 mm) were subjected to paper-making, to form nonwoven fabric having a Metsuke of 100 g/M2. The nonwoven fabric was dipped in a resin solution containing phenol resin of 30 wt% and impregnated with resin at an amount (after drying) of 200%. It was then dried, to form a prepreg 1 (-thickness: 1.0 mm). The prepreg was cut in a size of 80% of the area of the outside diameter of the lower die 3 (horizontal cross-section of the inside of the upper die 2). The prepregs thus cut were laminated on the lower die 3 as shown in Fig. 1, and the upper die 2 was put on the lower die 3 as shown in Fig. 2. The prepregs were hot-pressed at a pressure of 39 MPa (400 kgf/CM2) and at a temperature of 1600C, to form a deformed URP with the surface of each flat plate portion transferred with the irregular pattern from the upper die 2. The upper die 2 was then opened, and thus a deformed URP 4 having a shape shown in Fig. 3 was obtained. At this time. the pressing time. that isr hardening time was set at one minute. The thickness of each flat plate portion of the deformed URP 4 was 0.7 mm.

On the other hand, a deformed URP according to Comparative Example 2A was prepared as follows: First, the chops of the same carbon fibers as described above were fiber-loosened by a carding machine, to form a web. The webs in a specified amount were overlapped and needle-punched. to form nonwoven fabric having a Metsuke of 500 g/M2. The nonwoven fabric was impregnated with the same resin as described above in the same manner as in Example 2 and dried, to form a prepreg (thickness:

g..

1.0 mm). Next, the prepreg was cut in the same manner as Example 2. The prepregs thus cut were laminated on the lower die 3 and hot-pressed in the same manner as in Example 2r to obtain a product (deformed URP 4 according to Comparative Example 2A) having the same shape as that in Example 2.

The deformed CFRPs 4 according to Example 2 and Comparative Example 2A thus obtained were subjected to the same inspection and tests as in Example 1. As a resultp in Comparative Example 2Ar formability is poor and the material does not uniformly flow up to the rib portions 5 and the boss portions 6. On the contraryy in Example 2, the material uniformly flows up to the rib portions 5 and the boss portions 6. Moreover, the deformed URP 4 according to Comparative Example 2A exhibits a bending strength of 245 MPa (25 kgf/MM2), bending elastic modulus of 147 GPa (1500 kgf/mm2)y and 1zod impact value of 78 J/m (8 kgf. =/CM2). On the contrary, the deformed URP 4 according to Example 2 exhibits a bending strength of 255 MPa (26 kgf/MM2), bending elastic modulus of 157 GPa (1600 kgf/MM2) and 1zod impact value of 245 J/m (25 kgf-CM/CM2). As a result, the deformed UW 4 according to Example 2 is superior to the deformed URP 4 according to Comparative i --- Example 2A in the bending characteristics and impact value. ExamDle 3 A cover for a liquid crystal display (hereinafter, referred to as 11LCD cover") was manufactured using a deformed URP 4 prepared by laminating the same prepregs as in Example 1 (different in dimensions), and hotpressing them in the same condition as in Example 1. The LCD cover made of the deformed URP was subjected to f atigue testing. An LCD cover made of ABS resin having the same dimensions was also subjected to fatigue testing for a comparison. The f atigue test and the result thereof will he described below.

As shown in Fig. 4. the fatigue test was carried out by a method wherein, of hinge fixture fixing bosses 8 and 9, each two pieces on the right and left sides are fixed and a center 10 of the LCD cover 7 was applied with a one-point concentrated load. As a fatigue tester. a servo-pulser sold by Shimazu Seisakusho (trade name: ERF-FG1OKN-4LA), and the load was repeatedly applied at 0.2 Ez. The load was measured using a load cell of 1 KN (100 kgf). The loading condition is shown in Table 1. In this table, the maximum moment means a moment applied to each boss, and was calculated assuming that the distance between the loading point 10 and the center of the boss was taken as 15 cm.

The results of the fatigue test are summarized in Table 2. The displacement directly after the fatigue test is shown in Table 3. The breakage state of the URP made LCD cover 7 by the fatigue test (the repeated number at load case 1: 20,000 times) is shown in Fig. 5, and the breakage state of the ABS made LCD cover 7 (the repeated number at load case 1: 16,000 times) is shown in Fig. 6. As is apparent from these figures, in the URP made LCD cover, no crack is generated and the rigidity is not lowered so much as a whole. In casm.

for the ABS made LCD cover, in the case of the load case 2, after the repeated number of 16t000 timesy the root portion of the boss is broken nearly along the half circumference (for example, as shown in Fig. 6)y and thereby the displacement is abruptly increased to the extent that the boss cannot receive the hinge load; while in the case of load case lr after the repeated number of 16,000 times, the same phenomenon appears.

Accordingly, the URP made LCD cover (inventive deformed URP) is superior to the ABS made LCD cover (comparative deformed MP) in fatigue strength.

Table 1

Load Minimum Maximum Maximum case load load moment 1 0.49 N 6.96 N 0.52 N.m (0.05 kgf) (0.71 kgf) (5.33 kgf.cm) 0.49 N 10.00 N 0.75 N.m (0.05 kgf) (1.02 kgf) (7.65 kgf.cm) Table 2

Repeated Displace- Breakage state (see Fig. 5) number ment mm Load URP 10,000 7.4 No crack case 1 20,000 7.7 No crack ABS 10,000 6.7 No crack 16,000 8.2 Test is interrupted because the root portion of a boss is broken and a load cannot be supported.

Load URP 10,000 13.2 No crack case 2 ABS 1,600 No data Testis interrupted because the root portion of a boss is broken and a load cannot be supported.

The displacement is expressed by the vertical displacement of a load point, which means a difference between the cases applied with the maximum load and minimum load.

Table 3

Displacement= Load case 1 URP 7.4 ABS 6.0 Load case 2 URP 11.0 ABS No data ExamDle 4 The same prepreg as that in Example 1 was obtained in the same manner as in Example 1. in comparison.

the upper surface of a metal thin plate made of pure A1 (thickness: 0.3 mm) was coated with epoxy resin. Next, as shown in Fig. 7, the metal thin plate 10 was placed in a lower die 13 and five pieces of prepregs 11 were laminated thereon, and an upper die 12 was put on the lower die 13 as shown in Fig. 8. Thus, the prepregs 11 and the metal thin plate 10 were hot-pressed at a pressure of 39 MPa and at a temperature of 1500Cr to form a deformed URP having a metal thin plate integrated on the surface layer thereof. The deformed URP 14 according to Example 4 thus obtained has a shape shown in Fig. 9. in addition, the thickness of a flat plate portion of the deformed URP 14 (total thickness of the metal thin plate and the URP portion) is 0.9 mm. The volume ratio of the carbon fibers to the matrix resin of the MP is 25%. In Fig. 9, reference numeral 16 indicates a boss portion.

The deformed URP 14 according to Example 4 was subjected to clear paintingr followed by a visual inspection, and was subjected to a local heating test. The deformed URP 14 was then subjected to a bending test and an impact test using a bending test piece and an Izod impact test piece. The local heating test was carried out by a method wherein the deformed MP was locally heated under such a simulated condition that the deformed MP used as a housing was locally heated from the heat from electronic parts, and the temperature of the surface (opposed to the heated surface) of the deformed MP was measured. As a result, in the deformed WRP, carbon fibers were not visually observed on the surface, to thus improve the appearance, and any surface rolling is not generated, to thus improve the shaping accuracy and appearance. It exhibited excellent mechanical properties comparative to those of - 41 A '- 1 Comparative Example 4A described later, for exampler Izod impact value: 291 i/m, bending elastic modulus: 16 GPa. and bending strength: 246 MPa. The maximum temperature on the surface of the deformed URP 14 in the local heating test was 600C, which was significantly lower than that in Comparative Example 4A.

A deformed URP according to Comparative Example 4A was manufactured in the same manner as in Example 4 except that the metal thin plate 10 was not used. The deformed URP thus obtained was subjected to the same inspection and testing as in Example 4. As a result, in the deformed CPRP, carbon fibers were visually observed on the surface and the surface rolling was also recognized. In addition, the rolling was larger in the state after clear painting than in the state before clear painting. It exhibited an Izod impact value of 250 J/mr bending elastic modulus of 15 GPar and a bending strength of 240 MPa. The maximum temperature on the surface by the local heating test was as extremely high as 950C. Example 5 In this example, a local heating test was carried out to obtain the basic data regarding the effect of suppressing a local temperature rise due to local heating with respect to a deformed MP using a Cu thin plate as the metal thin plate. Specifically, as shown in Fig. 10, a MP plate 17 having a pure Cu thin plate 18 formed on the surface layer (that is, a complex plate having the pure Cu. thin plate 18 formed on the surface layer of the MP plate 17) was formed by pressing, and was subjected to local heating test. In this MP plate 17# phenol resin was used as the matrix resin of the CFRP, and carbon fibers (fiber length: 30 mm) was used as a reinforcing material. The complex plate has a width of 90 mm, a length of 140 mm, and a total thickness of 0.83 mm. The thickness of the MP plate portion 17 is 0.63 mm, and the thickness of the pure Cu thin plate 18 is 0.2 mm. The local heating test was carried out by a method wherein a square plate-like (side length: 48 mm) heat generator 19 of 4.81 W was placed as a heating source on the complex plate (on the pure Cu thin plate 18) through a carbon series resin spacer. On the other hand, a CC (Cu-Constantan) thermocouple was stuck on a temperature measurement point 20 on the lower side of the complex plate (surface of the MP plate 17). These were covered with a paper box (not shown), and a current is applied to the heat generator 19 for heating the complex plate, thus measuring the temperature at the temperature measurement point 20.

The maximum temperature at the temperature measurement point 20 (surface opposed to the side on which the heat generator 19 is present) after an elapse of one hour since start of heating was 64.20C. For comparison, the same local heating test was carried out using a M9 alloy plate or a single URP plate having the same dimensions as those of the complex plate. The maximum temperature at the temperature measurement point 20 after an elapse of one hour since start of heating was 62.00C for the Mg alloy plate and was 95.70C for the URP single plate. As a resulty it was revealed that the CM single plate was higher than the Mg alloy plate in the local maximum temperature by 300C or more; howeverp, the complex plate having the pure Cu thin plate formed on the surface layer of the URP was similar to the Mg alloy plate in the local maximum temperature. Consequently, the complex plate was significantly improved in the heat radiation characteristics. Example 6 In this example, a lower case of a note-type personal computer was manufactured using the deformed URP of the present invention. The essential portion o A the lower case is shown in Fig. 11. In CFRPs 22 and 23P phenol resin was used as the matrix resin, and carbon fibers (fiber length: 30. mm) was used as a reinforcing material. A Cu thin plate (thickness: 0.20 mm) was used as a metal thin plate 25 on the surface layer. The total thickness of the case (deformed MP) 21 is 0.83 mm. and the thickness of the MP portion 23 at the position where the metal thin plate 25 is present on the surface layer is 0.63 mm.

A heat generator (central processing unit) 24 was disposed inside the case 21 as shown in Fig. 11, and the case 21 was placed on a base 27 through a spacer. After that, the temperature rise on the outer surface of the case 21 was measured by operation of the heat generator 24. As a result, the temperature rise on the outer surface of the case 21 was maximized at the central position on the lower portion of the heat generator 24; however, it was increased only to 46.5C, and was smaller than that at the temperature measurement point 20 in Example 5. The reason for this is as follows. Namely, since the metal thin plate 25 was provided to extend to a upright wall 26 of the case 21. the heat from the heat generator 24 was diffused up to the metal thin plate 25 of the upright wall 26 of the case 21 and - 45 transmitted along the URP plate portion 23, and accordingly, the radiation surface area (outer surface of the case 21) is large and thereby the radiation amount is increased.

In particular, for the lower caser since it is usually contacted with a desk or knee, it is difficult for heat to escape from the surface as compared with the portion contacting the outside air such as the upper case. Accordingly, by provision of the metal thin plate 25 so as to extend up to the upright wall 26 of the case 21 as in this exampler it becomes possible to improve the radiation characteristic and hence to effectively suppress the temperature rise on the outer surface of the case. Example 7 A deformed URP 29 was manufactured in the same manner as in Example 4, except that the pure A1 thin plate (thickness: 0.3 mm) in Example 4 was replaced with a metal thin plate 28 which was obtained by providing crossing slits (width: 2 mm. and length: 20 mm) in a pure A1 plate (thickness: 0.2 mm, width: 100 mm and length: 150 mm) and applying a surface oxidizing treatment for roughening the surface layer. The deformed URP 29 has a shape shown in Fig. 12. In R d P addition, the thickness of a flat plate portion is the same as that in Example 4, that is, 0.9 mm. The deformed MP 29 was placed on a level block and measured in terms of camber while being fixed by spacers at four corners. The camber was 1.0 mm or less.

For comparison, a deformed URP in which the metal thin plate having the slits was replaced with a metal thin plate with no slit was measured in the same manner as in this example. As a result, the camber was 3 mm. Example 8 A URP plate 17 (complex plate) having the same shape as that shown in Fig. 10 in which the following Cu thin plate 18A, 18B or 18C was disposed on the surface layer was formed in the same manner as that in Example 5. In addition, phenol resin was used as the matrix resin and carbon fibers (fiber length: 25 mm) were used as a reinforcing material. The complex plate has a width of 100 mm, and a length of 140 mm. In addition, a thickness of the URP plate portion 17 is 0.7 mm and the thickness of metal thin plate is 0.2 mm.

Metal thin plate 18A: no slit Metal thin plate 18B; slits each having a width (1 mm) and a length (10 mm) (porosity: 10%) Metal thin plate 18C: slits each having a width (2 mm) and a length (20 mm) (porosity: 10%) The above complex plate was subjected to local heating test in the same manner as in Example 5. The maximum temperature at the temperature measurement point 20 after an elapse of one hour since the start of heating was 64.00C for the complex plate A using the metal thin plate 18A as the pure Cu thin plate; 67.20C for the complex plate B using the metal thin plate 18B; and 70.40C for the complex plate C using the metal thin plate 18C. In addition. for comparison, a single URP (thickness: 0.9 mm) was tested. As a result. the maximum temperature of the single C M is 95. 70C.

From Examples 7 and 8, it is revealed that by provision of voids such as slits in a metal thin plate provided on a URP surface layer, the radiation characteristic is slightly lowered but the camber of the product can be reduced. Examz)le 9 A carbon fiber reinforced plastic having a thickness of 1 mm was thermally decomposed at 5000C, in order to recover recycled carbon fibers. In the carbon fiberst the fiber diameter was 6.8 um, the fiber length 1 It p was in the range from 10 to 100 mm, and the tensile strength was 3578 MPa (365 k9f/MM2).

The recycled carbon f ibers were processed in nonwoven fabric. The nonwoven fabric was impregnated with phenol resin and was heated/dried in a drying furnace for 10 min at 1200C, to form a prepreg. The prepregs were hot-pressed in the same manner as in Example 1, thus forming a deformed URP 4 according to Example 9-1 having the same dimensions as those in Example 1.

New carbon fibers (fiber length: 10 to 100 mm, and tensile strength: 3430 MPa (350 kgf/mm2)) were mixed with the same recycled carbon f ibers as those in Example 9-1 at a weight ratio of 4:1, to form unwoven fabric. A deformed URP according to Example 9-2 having the same dimensions as those in Example 9-1 was manufactured in the same manner as in Example 9-1 except that the carbon fibers in Example 9-1 were replaced with the abovedescribed mixed carbon fibers.

A deformed URP according to Comparative Example 9A having the same dimensions as those in Example 9-1 was manufactured in the same manner as that in Example 9-1 except that the nonwoven fabric in Example 9-1 was replaced with unwoven fabric using new carbon fibers (fiber diameter: 7.2 um, fiber length: 10-100 mm, tensile strength: 3430 MPa (350 kgf/MM2)).

The deformed CFRPs according to Examples 9-1 and 9 2. and Comparative Example 9A were examined in terms of specific gravity, bending strength, bending elastic modulus, and EMI (electromagnetic wave) shield performance. The results are shown in Table 4. As is apparent from Table 4y the deformed URP according to Example 9-1 is substantially comparativeto the deformed URP according to Comparative Example 9A in terms of the bending strength, bending elastic modulus and EMI shielding performance. On the contrary, the deformed URP according to Example 9-2 is superior to those in Example 9-1 and Comparative Example 9A, particularly, in the terms of EMI shielding performance. The reason for this is that by mixing the recycled carbon f ibers with the new carbon fibers, the carbon fibers can be distributed in the deformed URP more uniformly than in the case of using only new carbon fibers.

P g.

Table 4

Items Characteristic value Inventive Inventive Comparative example 1 example 2 example 1 Specific gravity 1.50 1.50 1.51 Bending strength 240 245 240 (MPa) Bending elastic 14994 14700 14994 modulus (MPa) EMI shield 60 65 60 performance (dB) Note)... Shield value at 100 MEz d M I- 1

Claims

1. A deformed fiber reinforced plastic comprising: a matrix made of thermosetting resin in which carbon fibers having fiber lengths ranging from 10 to 100 mm are two-dimensionally and irregularly distributed as a reinforcing material, and a flat plate portion having a thickness of 1 mm or less,, wherein the outer surface of said flat plate portion has an irregular pattern transferred from a die, and the surface layer of each projecting portion of said irregular pattern is substantially made of resin.

2. A deformed fiber reinforced plastic according to claim 1, wherein the pitch of said irregular pattern is 5 mm or less and the height thereof is 10 um or more.

3. A deformed fiber reinforced plastic comprising: a matrix made of thermosetting resin in which carbon fibers having fiber lengths ranging from 10 to 100 mm are two-dimensionally and irregularly distributed as a reinforcing material, and a flat plate portion having a thickness of 1 mm or less, z i wherein the surface layer of said deformed fiberreinforced plastic is integrated with a metal thin plate by pressing.

4. A deformed fiber reinforced plastic according to claim 3, wherein the thickness of said metal thin plate is 0.5 mm or less.

5. A deformed fiber reinforced plastic according to claim 3 or 4P wherein said metal thin plate is made of Al, A1 alloy, Cu or Cu alloy.

6. A deformed fiber reinforced plastic according to any of claims 3 to 5, wherein said metal thin plate has slit-like voids; the total area of said voids is 500 MM2 or lessr and a porosity, that is, the area ratio of said voids to said metal thin plate, of 50% or less.

7. A deformed fiber reinforced plastic according to any of claims 1 to 6, wherein part or all of said carbon fibers comprise recycled carbon fibers recovered by thermal decomposition of carbon fiber reinforced plastics as a raw material.

1 p i

8. A deformed fiber reinforced plastic comprising: a matrix made of thermosetting resin in which carbon fibers are distributed as a reinforcing material, wherein part or all of said carbon fibers comprise recycled carbon f ibers recovered by thermal decomposition of carbon fiber reinforced plastics as a raw material.

9. A deformed fiber reinforced plastic according to claim 7 or 8P wherein the mixing ratio of said recycled carbon fibers based on the weight of the total carbon f ibers is in the range of from 5 to 100 wt%.

10. A deformed fiber reinforced plastic according to any of claims 7 to 9p wherein the fiber lengths of said recycled carbon f ibers in the carbon f iber reinf orced plastic as the raw material in the state before thermal decomposition is in the range of from 10 to 100 mm.

11. A deformed '-4ber reinforced plastic according to any of claims 7 to 10, wherein the amount of resin carbonate in said recycled carbon f ibers is in the range of from 0 to 60 wt%.

- 54 X 1

12. A deformed fiber reinforced plastic according to any of claims 1 to 11, wherein said thermosetting resin contains phenol resin in an amount of 30 wt% or more.

13. A deformed fiber reinforced plastic according to any of claims 1 to 12, wherein the fiber lengths of said carbon fibers is in the range of from 20 to 30 mm.

14. A deformed fiber reinforced plastic according to any of claims 1 to 13t wherein the volume ratio of said carbon fibers to said matrix is in the range of from 15 to 35%.

15. A deformed fiber reinforced plastic according to any of claims 1 to 14, wherein the bending strength is 147 MPa or more, the bending elastic modulus is 12 GPa or more, and the 1zod impact value of 98 i/m or more.

16. A deformed fiber reinforced plastic according to any of claims 1 to 15, wherein said plastic is formed in a deformed integral body having a flat plate portion and a projecting deformed portion, and carbon fibers at the root portion of said deformed portion are oriented in A IL 1 the direction of joining said flat plate portion to said deformed portion.

f