JP6679860B2 - Fiber-reinforced polyimide resin molding and method for manufacturing the same - Google Patents

Description

  The present invention relates to a fiber-reinforced polyimide resin molded body and a method for producing the same, and more specifically, it has excellent sliding performance, and the functional fibers in the polyimide resin are dispersed, and the shape stability during molding is improved. And a method for producing the same.

Conventionally, molded products made of fiber-reinforced resin, which is made by mixing functional fibers such as carbon fiber with resin, have excellent properties such as weather resistance, mechanical strength, and durability. Widely used for equipment, civil engineering / construction materials, sports equipment, etc.
For example, the following Patent Document 1 describes a carbon fiber reinforced resin molded product composed of a specific pitch-based short carbon fiber mixture and a matrix resin, and describes that it is suitably used for various electronic parts.
Further, Patent Document 2 below proposes a friction material composed of a resin composition for a friction material, which uses a specific aromatic polyimide oligomer as a binder such as carbon fiber. It is described that the heat resistance and mechanical properties of the binder itself are excellent and the moldability is good as compared with the case of using a phenol resin which is preferably used as a binder.
Further, Patent Document 3 below proposes a rolling element made of a carbon fiber reinforced synthetic resin containing 10 to 70% by weight of carbon fiber having a specific thermal conductivity.

When such a fiber-reinforced resin molded product is used as a slidable member such as a bearing, it has high mechanical strength such as strength and rigidity, a small dynamic friction coefficient and a small amount of wear, and a high limit PV value. Such properties are required, and it is desired to use an addition reaction type polyimide resin having excellent mechanical strength, heat resistance and durability as well as resin impregnation property as a matrix resin.
As an addition reaction type polyimide resin, a high-performance addition reaction type polyimide resin capable of producing a carbon fiber reinforced composite by transfer molding (RTM) and resin press fitting (RI) has also been proposed (Patent Document 4).

Patent No. 4538502 JP, 2009-242656, A JP, 2011-127636, A Special Table 2003-526704

However, when the addition reaction type polyimide resin is used as the matrix resin of the fiber-reinforced resin molded product, even if excellent heat resistance, durability and mechanical strength are obtained, warpage occurs in the obtained molded product, There is a problem in that it cannot be put to practical use as a slidable member.
As a result of diligent research on the cause by the present inventors, the following facts were found. That is, since the addition reaction type polyimide resin that can be suitably used as a matrix resin for functional fibers such as carbon fibers has a low melt viscosity in a prepolymer state, when the prepolymer is mixed with the functional fibers, the functional fibers become As a result of sedimentation and uneven distribution in the prepolymer, the resin is cross-linked and cured in this state, and the amount of shrinkage of the molded product varies depending on the amount of functional fibers present. It was found that the molded body was warped.

Therefore, an object of the present invention is to provide a fiber-reinforced polyimide resin molded product which has excellent sliding performance, is free from warpage, and has excellent shape stability during molding.
Another object of the present invention is to provide a manufacturing method capable of molding a fiber-reinforced polyimide resin molding having excellent sliding performance with good shape stability.

According to the present invention, there is provided a resin molded product in which a functional fiber is dispersed in an addition reaction type polyimide resin, the resin molded product having a limit PV value of 3000 kPa · m / s or more. To be done.
In the resin molded product of the present invention,
1. The matrix of the composition constituting the resin molded body is an addition reaction type polyimide resin, the functional resin is impregnated with the polyimide resin,
2. The content of the functional fiber is 5 to 200 parts by weight with respect to 100 parts by weight of the addition reaction type polyimide,
3. The functional fiber is any one or more of carbon fiber, glass fiber, aramid fiber, and metal fiber,
4. The functional fiber is a carbon fiber having an average fiber length of 50 to 6000 μm and an average fiber diameter of 5 to 20 μm,
5. Further, at least one or more of graphite, molybdenum disulfide, PTFE (tetrafluoroethylene resin), fine carbonaceous material, and metal powder is contained at 5 to 40 parts by weight with respect to 100 parts by weight of the addition reaction type polyimide.
Is preferred.

According to the present invention, the addition reaction type polyimide resin prepolymer and the functional fiber are kneaded at a temperature not lower than the melting point of the addition reaction type polyimide resin and not higher than the thermosetting start temperature, and the dispersion kneading step is obtained through the dispersion kneading step. The obtained mixture has a melt viscosity of 10 to 5000 Pa · s under a temperature condition of 300 to 320 ° C., and a shaping step of shaping the mixture under a temperature condition of the thermosetting initiation temperature of the addition reaction type polyimide resin or higher. A method for producing a resin molded body is provided, which comprises:
In the method for producing a resin molded body of the present invention,
1. Between the dispersion and kneading step and the shaping step, the kneaded material obtained in the dispersion and kneading step has a viscosity of 300 to 300 by holding the kneaded material at a temperature not lower than the thermosetting start temperature of the addition reaction type polyimide resin for a certain period of time. Having a thickening step of adjusting the melt viscosity to 10 to 5000 Pa · s under the temperature condition of 320 ° C. ,
2. The content of the functional fiber is 5 to 200 parts by weight with respect to 100 parts by weight of the addition reaction type polyimide,
3. After the mixture obtained through the dispersion kneading step was mixed cooling and pulverized, to pressure圧賦form,
4 . It pre-SL addition reaction type polyimide resin is a polyimide resin having a phenyl ethynyl group as an additional reactive group,
5 . When the addition reaction type polyimide resin is a polyimide resin having a phenylethynyl group as an addition reaction group, in the thickening step, it is maintained at a temperature of 310 ± 10 ° C. for 30 to 60 minutes,
6 . The shaping step is performed by compression molding,
Is preferred.

In the fiber-reinforced polyimide resin molded product of the present invention, an addition reaction type polyimide resin excellent in heat resistance, durability and mechanical strength is used as a matrix resin, and 5 to 200 parts by weight relative to 100 parts by weight of this addition reaction type polyimide. It becomes possible to express excellent sliding performance with a limit PV value of 3000 kPa · m / s or more by blending in the amount of. Moreover, since the functional fiber is molded by being crosslinked and cured in a state where the functional fiber is uniformly dispersed in the molded product, there is no distortion such as warpage and it can be suitably used as a slidable member. The limit PV value is a value obtained by the product of the surface pressure P and the velocity V when the frictional force sharply rises, and the limit PV value is calculated as an index for determining whether the sliding member is suitable for the usage environment. It is common to Under conditions close to the limit PV value, dynamic friction coefficient and sample temperature rise due to melting and seizure of resin due to frictional heat of sliding surface, abnormal wear of material, etc. are observed. High value indicates high sliding performance. Means that.
Further, the fiber-reinforced polyimide resin molded product of the present invention, the functional fiber is impregnated with the addition reaction type polyimide, and contains a predetermined amount of the functional fiber, excellent sliding, when used as a sliding member In addition, not only stable performance can be maintained for a long period of time, but also deformation due to warpage can be prevented, so that it is excellent in productivity and can reduce the change in PV value due to abrasion during long-term use. Easy to manage devices.

  Further, in the molding method of the fiber-reinforced polyimide resin molding of the present invention, after the dispersion kneading step of the addition reaction type polyimide resin and the functional fiber, the viscosity of the prepolymer (imide oligomer) of the polyimide resin in a molten state is increased. By providing the viscous step, it becomes possible to maintain the state in which the functional fibers are uniformly dispersed in the prepolymer, and warp the fiber-reinforced polyimide resin molded body in which the functional fibers do not settle and are not unevenly distributed. It becomes possible to mold without causing deformation.

It is a figure for demonstrating the measuring method of the limit PV value in an Example. It is a figure for demonstrating the measuring method of the amount of curvature in an Example.

(Resin molding)
The fiber-reinforced polyimide resin molded body of the present invention is a resin molded body in which functional fibers are dispersed in an addition reaction type polyimide resin described later, and it is important that the limit PV value is 3000 kPa · m / s or more. In addition to having heat resistance, durability and mechanical strength, it has a large limit PV value and excellent sliding performance.

[Addition reaction type polyimide resin]
In the present invention, it is an important feature that an addition reaction type polyimide resin is used as the polyimide resin which becomes a matrix of the composition constituting the fiber reinforced polyimide resin molded body.
The addition reaction type polyimide resin used in the present invention is composed of an aromatic polyimide oligomer having an addition reaction group at the terminal, and the one prepared by a conventionally known production method can be used. For example, aromatic tetracarboxylic dianhydride, aromatic diamine, and a compound having an anhydride group or an amino group together with an addition reaction group in the molecule, the total of the equivalent of each acid group and the total of each amino group It can be easily obtained by using the same amount and preferably reacting in a solvent. As a method of the reaction, a method of polymerizing at a temperature of 100 ° C. or lower, preferably 80 ° C. or lower for 0.1 to 50 hours to form an oligomer having an amic acid bond, and then chemically imidizing with an imidizing agent, , A method comprising two steps of heating at a high temperature of about 140 to 270 ° C. for thermal imidization, or from the first step of performing a polymerization / imidization reaction at a high temperature of 140 to 270 ° C. for 0.1 to 50 hours. Can be exemplified.
The solvent used in these reactions is not limited to this, but is N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, γ-butyl lactone, N- An organic polar solvent such as methylcaprolactam can be preferably used.

In the present invention, the addition reaction group at the terminal of the aromatic imide oligomer is not particularly limited as long as it is a group that undergoes a curing reaction (addition polymerization reaction) by heating when producing a resin molded product, but a curing reaction is preferably performed. Considering that it can be carried out, and that the obtained cured product has good heat resistance, preferably any reactive group selected from the group consisting of a phenylethynyl group, an acetylene group, a nadic acid group, and a maleimide group. In particular, a phenylethynyl group is preferable because it does not generate a gas component due to a curing reaction, and the resulting resin molded article has excellent heat resistance and mechanical strength. is there.
These addition reaction groups are a reaction in which a compound having an anhydride group or an amino group together with an addition reaction group in the molecule forms an imide ring, preferably with an amino group or an acid anhydride group at the terminal of an aromatic imide oligomer. Is introduced at the end of the aromatic imide oligomer.
The compound having an anhydride group or an amino group together with an addition reaction group in the molecule is, for example, 4- (2-phenylethynyl) phthalic anhydride, 4- (2-phenylethynyl) aniline, 4-ethynyl-phthalic anhydride, 4 -Ethynylaniline, nadic acid anhydride, maleic acid anhydride and the like can be preferably used.

  Examples of the tetracarboxylic acid component forming the aromatic imide oligomer having an addition reaction group at the terminal include 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride and 2,2 ′, 3,3′-biphenyl. At least selected from the group consisting of tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, and 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride. One tetracarboxylic dianhydride can be illustrated, and in particular, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride can be preferably used.

  The diamine component forming the aromatic imide oligomer having an addition reactive group at the terminal is not limited to this, but is 1,4-diaminobenzene, 1,3-diaminobenzene, 1,2-diaminobenzene, 2,6- Diethyl-1,3-diaminobenzene, 4,6-diethyl-2-methyl-1,3-diaminobenzene, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6- Diamines such as diamines having one benzene ring, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone , 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, bis (2,6-diamino) Tyl-4-aminophenoxy) methane, bis (2-ethyl-6-methyl-4-aminophenyl) methane, 4,4′-methylene-bis (2,6-diethylaniline), 4,4′-methylene- Bis (2-ethyl, 6-methylaniline), 2,2-bis (3-aminophenyl) propane, 2,2-bis (4-aminophenyl) propane, benzidine, 2,2'-bis (trifluoromethyl) ) Benzidine, 3,3'-dimethylbenzidine, 2,2-bis (4-aminophenyl) propane, 2,2-bis (3-aminophenyl) propane, and the like, diamine having two benzene rings, 1,3- Bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) ) Such as diamine 2,2-bis [4- [4-aminophenoxy] phenyl] propane and 2,2-bis [4- [4-aminophenoxy] phenyl] hexafluoropropane having three benzene rings such as benzene. A diamine having four benzene rings and the like can be used alone or in combination of two or more.

  Among these, 1,3-diaminobenzene, 1,3-bis (4-aminophenoxy) benzene, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, and 2,2′-bis (trifluoro It is preferable to use a mixed diamine composed of at least two aromatic diamines selected from the group consisting of methyl) benzidine, and particularly 1,3-diaminobenzene and 1,3-bis (4-aminophenoxy) benzene. , A mixed diamine consisting of a combination of 3,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl ether, a mixed diamine consisting of a combination of 3,4'-diaminodiphenyl ether and 1,3-bis (4-aminophenoxy) Mixed diamines in combination with benzene, 4,4'- Mixed diamine consisting of a combination of aminodiphenyl ether and 1,3-bis (4-aminophenoxy) benzene, and 2,2′-bis (trifluoromethyl) benzidine and 1,3-bis (4-aminophenoxy) benzene It is preferable to use a mixed diamine composed of a combination of the above from the viewpoints of heat resistance and moldability.

The aromatic imide oligomer having an addition reaction group at the terminal used in the present invention preferably has a repeating unit of the imide oligomer of 0 to 20, particularly 1 to 5, and has a styrene-equivalent number average molecular weight by GPC. Is preferably 10,000 or less, and particularly preferably 3,000 or less. When the number of repeating units is within the above range, the melt viscosity can be adjusted to an appropriate range and the functional fibers can be mixed. Further, it is not necessary to mold at a high temperature, and it is possible to provide a resin molded product having excellent moldability, heat resistance, and mechanical strength.
The adjustment of the repeating number of the repeating unit can be performed by changing the ratio of the compound having an anhydride group or an amino group with an addition reaction group in the molecule, aromatic tetracarboxylic dianhydride, aromatic diamine, By increasing the proportion of the compound having an anhydride group or an amino group together with an addition reaction group in the molecule, the molecular weight is lowered and the number of repeating units is decreased, and when the proportion of this compound is decreased, the molecular weight is increased and the repeating number is increased. The number of repetitions of a unit becomes large.

  For the addition reaction type polyimide resin, a known resin additive such as a flame retardant, a colorant, a lubricant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, a filler, etc., depending on the intended use of the resin molded product. It can be blended according to the prescription.

[Functional fiber]
In the present invention, as the functional fiber to be dispersed in the above-mentioned addition reaction type polyimide resin, a conventionally known substance can be used, such as a carbon fiber, an aramid fiber, a glass fiber, and a metal fiber, a conventionally known functionality. Although fibers can be used, carbon fibers can be particularly preferably used.
Among them, carbon fibers having an average fiber length of 50 to 6000 μm and an average fiber diameter of 5 to 20 μm can be preferably used. If the average fiber length is shorter than the above range, the effect of the carbon fiber as a reinforcing material cannot be sufficiently obtained, while if it is longer than the above range, the dispersibility in the polyimide resin becomes poor. . Further, when the average fiber diameter is smaller than the above range, it is inferior in handleability and is expensive, while when the average fiber diameter is larger than the above range, the sedimentation rate of the functional fiber is increased, and the functional fiber is Is likely to be unevenly distributed, and the strength of the fiber tends to be lowered, so that the effect as a reinforcing material may not be sufficiently obtained.

  The content of the functional fiber has a significant influence on the sliding performance of the resin molded product and the occurrence of warpage during molding, and in the present invention, the functional fiber is 100 parts by weight of the addition reaction type polyimide. 5 to 200 parts by weight, and particularly 10 to 150 parts by weight, is suitable for obtaining a molded product having excellent sliding performance, warpage, and excellent shape stability. is there. If the amount of the functional fiber is less than the above range, the limit PV value may be less than the above value and the slidability may be deteriorated. Further, the warp of the resin molded body may increase. On the other hand, when the amount of the functional fiber is larger than the above range, the limit PV value may be lower than that in the above range. In addition, excessive thickening may occur, and it may not be possible to mold.

  In the present invention, at least one kind of fine carbonaceous material such as graphite, PTFE, molybdenum disulfide and carbon black, and inorganic material such as metal powder such as aluminum powder and copper powder may be further contained together with the functional fiber. it can. The above inorganic material is preferably contained in an amount of 5 to 40 parts by weight, particularly 5 to 30 parts by weight, based on 100 parts by weight of the addition reaction type polyimide. If the amount of the inorganic material is less than the above range, the effect obtained by blending the inorganic material cannot be sufficiently obtained, while if the amount of the inorganic material is more than the above range, the friction coefficient increases and the wear resistance decreases, etc. On the contrary, the sliding performance may be impaired.

(Method for manufacturing resin molded body)
The method for producing a resin molded product of the present invention is a dispersion in which at least a prepolymer (imide oligomer) of an addition reaction type polyimide resin and a functional fiber are kneaded at a temperature not lower than the melting point of the addition reaction type polyimide resin and not higher than a thermosetting start temperature. A kneading step (A), a shaping step (C) of shaping the mixture that has undergone the dispersion kneading step under a temperature condition of the thermosetting initiation temperature of the reactive polyimide resin or higher, and, if necessary, the dispersion kneading step. Between (A) and the shaping step (C), the viscosity of the kneaded product is required by holding the kneaded product obtained by the dispersion kneading process at a temperature not lower than the thermosetting start temperature of the reactive polyimide resin for a certain period of time. It is characterized by having a thickening step (B) of increasing the viscosity of the kneaded product in an appropriate range.
As described above, the addition reaction type polyimide resin used for molding the resin molded body of the present invention has a low viscosity in the state of the prepolymer before the crosslinking and curing, so that it is precipitated when the functional fiber is contained, As a result, the functional fibers are ubiquitous and warp occurs in the molded body. In the present invention, after the dispersion kneading step (A), the viscosity of the prepolymer is increased by the thickening step (B) to prevent the functional fibers from settling, and the shaping step while maintaining the state. Since it is shaped in (C), the functional fibers are uniformly dispersed and evenly contracted during heating and curing, so that a molded body having no warp can be formed.

[Dispersion and kneading process]
The prepolymer and the functional fiber are mixed by heating the prepolymer (imide oligomer) of the addition reaction type polyimide resin and the functional fiber at a temperature higher than the melting point of the addition reaction type polyimide resin and kneading the prepolymer while melting. . At this time, as described above, the functional fiber is used in an amount of 5 to 200 parts by weight, particularly 10 to 150 parts by weight, based on 100 parts by weight of the addition reaction type polyimide. Further, the above-mentioned inorganic materials can be blended in the above-mentioned amounts.
For the kneading of the prepolymer and the functional fiber, a conventionally known mixer such as a Henschel mixer, a tumbler mixer, a ribbon blender can be used, but it is important to suppress the breakage of the functional fiber and disperse it. Therefore, it is particularly preferable to use a batch type pressure kneader (kneader).

[Thickening process]
Then, when the melt viscosity of the melt-kneaded mixture of the prepolymer and the functional fiber under the temperature condition of 300 to 320 ° C. is 10 or less, the temperature of the polyimide resin used in the mixture is around 310 ± 10 ° C. By holding the temperature for 30 to 60 minutes, the melt viscosity under the temperature condition of 300 to 320 ° C. is adjusted to the range of 10 to 5000 Pa · s.
That is, by holding the mixture of the prepolymer and the functional fiber at a temperature of 310 ± 10 ° C. for 30 to 60 minutes using an electric furnace or the like, the prepolymer gradually starts to be crosslinked and the viscosity increases. Furthermore, the functional fiber impregnated in the prepolymer by the dispersion kneading step can maintain the dispersed state without settling in the prepolymer due to this increase in viscosity. Further, by setting the heating temperature and the holding time in the above range, it becomes possible to raise only the viscosity to the above range without completely crosslinking and curing the prepolymer. Therefore, the thickening step is performed at a temperature equal to or higher than the thermal curing start temperature of the prepolymer and lower than the temperature at which the prepolymer is completely crosslinked and cured.
Incidentally, in the addition reaction type polyimide resin, the reaction start temperature depends on the addition reaction group, and in the polyimide resin having a phenylethynyl group suitable as the addition reaction group in the present invention, the temperature is 310 ± 10 which is near the thermosetting start temperature. It is desirable to heat at a temperature of 30 ° C. for 30 to 60 minutes. If the functional fiber also falls within the above viscosity range, this step is not necessary.

  In the present invention, it is desirable that the mixture of the prepolymer and the functional fiber that has been subjected to the dispersion and kneading step is cooled and solidified, and then formed into a lump of a predetermined size. As a result, the mixture in which the functional fibers are dispersed in the prepolymer can be stored with time, and the handleability is also improved.

[Shaping process]
The mixture of the prepolymer and the functional fiber whose melt viscosity is adjusted to the above range through the thickening step is shaped under a temperature condition of the thermosetting start temperature or higher of the polyimide resin to be used, and as a resin molded body having a desired shape. Molded.
When performing the shaping step continuously with the thickening step, a mixture of the thickened polyimide prepolymer in the molten state and the functional fiber is introduced into a mold and heated at a temperature higher than the thermosetting start temperature. The resin molded product is molded by curing by doing so, as described above, when using a mixture obtained by cooling and solidifying the mixture of the prepolymer and the functional fiber after the thickening step and pulverizing and mixing, use an electric furnace or the like. By heating at a temperature higher than the melting point of the addition reaction type polyimide resin to melt the mixture and then introducing it into the molding die to heat-cure it, or by melting the mixture in the molding die and heat-curing the resin molding. It can be molded.
The shaping is preferably performed by compression molding or transfer molding in which the mixture introduced into the molding die is compressed and compressed, but it can also be molded by injection molding or extrusion molding.

(Measurement of limit PV value)
Using a thrust-type wear tester conforming to JIS K 7218 (plastic sliding wear test method), the ring-on-disk type as shown in FIG. 1 was used to measure the surface pressure every 5 to 10 minutes under constant speed conditions. A limit PV value is defined as the product of the surface pressure (P) and the velocity (V) immediately before the limit when the frictional force is rapidly increased or a significant deformation and abrasion powder are generated.
Limit PV value measurement conditions Test speed; 0.5 m / s, initial surface pressure; 0.5 MPa
Surface pressure step 0.5 MPa / 10 min (-10 MPa)
1 MPa / 10 min (10 MPa-)
Counterpart material: S45C ring Surface roughness Ra 0.8 μm
Outer diameter 25.6 mm, inner diameter 20 mm (contact area 2 cm ² )
Test environment: 23 ± 2 ℃, 50% ± 5% RH
Testing machine: A & D company friction wear testing machine EMF-III-F

(Fiber dispersion)
The cross section of the molded body was observed, and the presence or absence of uneven distribution of fibers was confirmed visually or by a scanning electron microscope (S-3400N manufactured by Hitachi High-Tech Technology Co., Ltd.). The one in which the fibers were dispersed was evaluated as ◯, and the one in which the fiber sedimentation was observed was evaluated as x.

(Measurement of warp amount)
The warp amount t (mm) and the product diameter dimension D (mm) shown in FIG. 2 were measured, and the warp / diameter ratio was calculated by the following formula (1).
Warp / diameter ratio (%) = t / D × 100
t: test piece warp amount (mm), T: product thickness (mm)
The warp / diameter ratio was judged as good or bad by less than 1.5% and as bad by 1.5% or more.

(Measurement of melt viscosity)
The melt viscosity at 310 ° C. was measured by a rheometer (ARES manufactured by TA instrument). The measurement mode was dynamic frequency dispersion, the angular frequency was 0.1 to 500 rad / s, and the melt viscosity under the condition of 0.1 rad / s was the measured value.

(Example 1)
11.1 parts by weight of pitch-based carbon fiber (K223HM manufactured by Mitsubishi Plastics Co., Ltd.) having an average single fiber length of 200 μm was mixed with 100 parts by weight of addition polymerization type polyimide (PETI-330 manufactured by Ube Industries, Ltd.), and the mixture was increased by a kneader. Melt kneading was carried out at 280 ° C. for 30 minutes under atmospheric pressure. Then, a mixture (bulk molding compound, hereinafter BMC) cooled to room temperature was obtained. The obtained BMC is divided into a size that is easy to handle, then held in an electric furnace at 310 ° C. for 30 minutes, rapidly cooled and re-crushed, and the resin mixture (thickened BMC) is 280 in a mold for a compression molding machine. After melting and soaking by holding at a temperature of ℃ to 320 ℃ for a certain period of time, while pressurizing to 2.4 MPa, raise the temperature to 371 ℃ at a temperature rising rate of 3 ℃ / min, hold for 60 minutes, slowly cool and φ40 mm thickness. A 3 mm thick plate was obtained. The obtained plate material was subjected to a curing treatment at 357 ° C. for 6 hours and then processed into a desired size to obtain a test piece.

(Example 2)
42.9 parts by weight of a pitch-based carbon fiber (K223HM manufactured by Mitsubishi Plastics Co., Ltd.) having an average single fiber length of 200 μm was mixed with 100 parts by weight of an addition polymerization type polyimide (PETI-330 manufactured by Ube Industries, Ltd.), and a large amount was obtained by a kneader. Melt kneading was carried out at 280 ° C. for 30 minutes under atmospheric pressure. Then, BMC cooled to room temperature was obtained. After dividing the obtained BMC into a size that fits in the mold, the BMC is melted and soaked in the mold for the compression molding machine by holding it at 280 ° C. to 320 ° C. for a certain time, and then to 11 MPa. While pressurizing, the temperature was raised to 371 ° C. at a temperature rising rate of 3 ° C./min, held for 1 hour, and gradually cooled to obtain a plate having a diameter of 100 mm and a thickness of 3 mm. The obtained plate material was subjected to a curing treatment at 357 ° C. for 6 hours and then processed into a desired size to obtain a test piece.

(Example 3)
Same as Example 2 except that the blending amount of carbon fiber was changed to 100 parts by weight.

(Example 4)
Same as Example 1 except that the temperature was not kept at 310 ° C. in the electric furnace. Since the obtained resin molded body had warpage, the front and back layers were shaved to have a predetermined parallelism, and the limit PV value was measured. Although the limit PV value of the surface before shaving was not measured, when the measured surface was observed, it was apparent that a large amount of carbon fibers were present compared with the surface before shaving. From this, too, it is understood that a predetermined amount of carbon fiber is required on the surface.

(Comparative Example 1)
Same as Example 2 except that no carbon fiber was blended.

(Comparative example 2)
Same as Example 2 except that the amount of carbon fiber was changed to 233 parts by weight. The viscosity of BMC obtained after melt-kneading was high, and inadequate stretching was observed in the mold during the shaping step, and the PV limit value could not be measured.

  Table 1 shows the results of measuring the limit PV value of the test pieces obtained in Examples 1 to 4 and Comparative Examples 1 and 2, the presence / absence of a thickening process, the quality of fiber dispersion, and the presence / absence of defects in molded articles.

(Example 5)
Same as Example 1 except that BMC was placed in an electric furnace at 310 ° C. for 45 minutes.

(Example 6)
Same as Example 1 except that BMC was placed in an electric furnace at 310 ° C. for 60 minutes.

(Comparative Example 3)
Same as Example 1 except that BMC was placed in an electric furnace at 310 ° C. for 15 minutes. It should be noted that BMC leaked from inside the mold and warped deformation due to uneven distribution of fibers occurred.

(Comparative example 4)
Same as Example 1 except that BMC was placed in an electric furnace at 310 ° C. for 75 minutes. The resin viscosity was so high that it could not be molded without stretching.

Table 2 shows the measurement results of the shapeability of the test pieces obtained in Examples 1, 5, 6 and Comparative Examples 3 and 4, the quality of dispersion of fibers, the warp / diameter ratio, and the melt viscosity.

  INDUSTRIAL APPLICABILITY The resin molded product of the present invention is excellent in sliding performance with a limit PV value of 3000 kPa · m / s or more, and therefore can be used in various applications as a slidable member in the fields of automobiles, electric / electronics and the like.

Claims (13)

  A resin molded body comprising functional reaction fibers dispersed in an addition reaction type polyimide resin, wherein the resin molded body has a limit PV value of 3000 kPa · m / s or more.   The resin molded body according to claim 1, wherein the matrix of the composition forming the resin molded body is an addition reaction type polyimide resin, and the functional fiber is impregnated with the polyimide resin.   The resin molded product according to claim 1, wherein the content of the functional fiber is 5 to 200 parts by weight with respect to 100 parts by weight of the addition reaction type polyimide.   The resin molding according to claim 1, wherein the functional fiber is at least one selected from carbon fiber, glass fiber, aramid fiber, and metal fiber.   The resin molding according to any one of claims 1 to 4, wherein the functional fiber is a carbon fiber having an average fiber length of 50 to 6000 µm and an average fiber diameter of 5 to 20 µm.   Furthermore, 5 to 40 parts by weight of at least one or more of graphite, molybdenum disulfide, PTFE (tetrafluoroethylene resin), fine carbonaceous material and metal powder is contained with respect to 100 parts by weight of addition reaction type polyimide. The resin molding according to any one of 1 to 5. Dispersion and kneading step of kneading the prepolymer of the addition reaction type polyimide resin and the functional fiber at a temperature not lower than the melting point of the addition reaction type polyimide resin and not higher than the thermosetting start temperature,
The mixture obtained through the dispersion-kneading step has a melt viscosity of 10 to 5000 Pa · s under a temperature condition of 300 to 320 ° C., and the mixture is subjected to a temperature condition of the thermosetting initiation temperature of the addition reaction type polyimide resin or higher. The method for producing a resin molded product, which comprises at least a shaping step of shaping. Between the dispersion and kneading step and the shaping step, the kneaded material obtained in the dispersion and kneading step has a viscosity of 300 to 300 by holding the kneaded material at a temperature not lower than the thermosetting start temperature of the addition reaction type polyimide resin for a certain period of time. The manufacturing method according to claim 7, further comprising a thickening step of adjusting the melt viscosity to 10 to 5000 Pa · s under a temperature condition of 320 ° C.   The method for producing a resin molded product according to claim 7, wherein the content of the functional fiber is 5 to 200 parts by weight with respect to 100 parts by weight of the addition reaction type polyimide. After the mixture obtained through the dispersion kneading step was mixed cooling and pulverizing method according to claim 7 or 9, wherein for pressurizing圧賦form. The method according to any one of claims 7-10 is a polyimide resin having the addition reaction type polyimide resin, phenylethynyl group as an additional reactive group. The manufacturing method according to claim 11 , wherein in the thickening step, the temperature is held at 310 ± 10 ° C for 30 to 60 minutes. Said shaping step, the manufacturing method according to any one of claims 7-12 which is carried out by compression molding.