Molded body and manufacturing method of the molded body

Abstract

The present invention provides a molded body and a method for manufacturing the molded body, which is a molded body of a prepreg containing a resin and reinforcing fibers, the molded body including a region B where reinforcing fibers A, among the reinforcing fibers, have a cross-sectional area a1 at the surface of the molded body, the cross-sectional area a1 of which is present on the surface of the molded body, and an average cross-sectional area a2 of the reinforcing fibers A, such that a1>a2, occupies 50% or more of the surface area of ​​the molded body, and the region B occupies 10% or more of the surface area of ​​the molded body.

Description

[Technical field]

[0001] The present invention relates to a molded article and a method for manufacturing the molded article, and more particularly to a molded article of a prepreg containing a resin and reinforcing fibers and a method for manufacturing the same. [Background technology]

[0002] Molded articles containing resin and reinforcing fibers have been developed as reinforced resin molded articles. For example, Patent Document 1 discloses a method for producing a composite molded article by forming a continuous fiber-reinforced thermoplastic resin sheet consisting of continuous fibers oriented in one direction and a thermoplastic resin composition B into a three-dimensional shape in an injection molding die and integrating it with a thermoplastic resin composition A, the method being characterized in that the continuous fiber-reinforced thermoplastic resin sheet has cuts. Meanwhile, in recent years, there has been an increasing demand for molded articles containing such resins and reinforcing fibers to have attractive external designs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-135981 A Summary of the Invention [Problem to be solved by the invention]

[0004] When applying patterns to molded products made of resin and reinforcing fibers, the mainstream method has been to leave the arrangement of the reinforcing fibers, such as weaving, knitting, or random scattering, on the exterior. In particular, there are some methods such as Nishijin-ori that have a complex and intricate appearance, but all of them have a continuous pattern. However, in order to give the molded product a unique look, there is a demand for molded products that have further design features using reinforcing fibers. Furthermore, even if a unique look is applied, if the surface is rough, with many reinforcing fibers protruding from the surface, the uniqueness is diminished. The present invention aims to solve such problems, and to provide a molded body containing a resin and reinforcing fibers, which has excellent designability and a smooth surface, and a method for manufacturing the molded body. [Means for solving the problem]

[0005] As a result of investigations conducted by the present inventors in light of the above problems, the above problems were solved by the following means. <1> A prepreg molding containing resin and reinforcing fibers, Among the reinforcing fibers, when a cross-sectional area a1 of the reinforcing fibers A, the cross-section of which is present on the surface of the molded body, is compared with an average cross-sectional area a2 of the reinforcing fibers A, a1>a2 is satisfied, and a region B is included in which the reinforcing fibers A occupy 50% or more; The region B occupies 10% or more of the surface area of ​​the molded article. <2> The resin includes a thermoplastic resin. <1> The molded article according to claim 1. <3> The resin satisfies at least one of a melting point of 150° C. or more and 330° C. or less and a glass transition temperature of 100° C. or more. <1> or <2> The molded article according to claim 1. <4> The molded body includes a metal film C, and a part of the metal film C is present on the surface of the molded body. <1> ~ <3> 13. The molded article according to claim 12 . <5> The molded body includes a colored resin film D, and a part of the colored resin film D is present on the surface of the molded body. <1> ~ <4> 13. The molded article according to claim 12 . <6> The proportion of reinforcing fibers in the prepreg is 40 to 80% by volume. <1> ~ <5> 13. The molded article according to claim 12 . <7> The difference between the refractive index of the resin and the refractive index of the reinforcing fiber at a wavelength of 589 nm is 0.05 or more. <1> ~ <6> 13. The molded article according to claim 12 . <8> The difference between the cross-sectional area a1 and the cross-sectional area a2 in the region B of the reinforcing fiber A is 5 μm 2 That's all. <1> ~ <7> 13. The molded article according to claim 12 . <9> The reinforcing fibers constituting the prepreg include tailored fiber placement processed materials and / or woven fabrics; <1> ~ <8> 13. The molded article according to claim 12 . <10> The region B is 20 to 80% of the surface area of ​​the molded body. <1> ~ <9> 13. The molded article according to claim 12 . <11> A method for producing a molded body, comprising cutting a heated and pressurized body obtained by stacking two or more plies of prepregs containing resin and reinforcing fibers, The cutting process is carried out in such a way that, when a cross-sectional area a1 of reinforcing fiber A, the cross-section of which is present on the surface of the molded body, on the surface of the molded body is compared with an average cross-sectional area a2 of the reinforcing fiber A, a1>a2 is satisfied, and the reinforcing fiber A occupies 50% or more of the surface area of ​​the molded body, and the region B occupies 10% or more of the surface area of ​​the molded body. <12> The cutting process is performed using a 5-axis machining center. <11> A method for producing the molded article according to claim 1. <13> The cutting angle θ when performing the cutting process is 3 to 40° with respect to the reference plane. <11> or <12> A method for producing the molded article according to claim 1. <14> The maximum cutting temperature during the cutting process is 50 to 100 ° C. <11> ~ <13> 13. A method for producing the molded article according to any one of the above items. <15> The molded body <1> ~ <10> The molded body according to any one of the above items. <11> ~ <14> 13. A method for producing the molded article according to any one of the above items. Effect of the Invention

[0006] According to the present invention, it is possible to provide a molded article containing a resin and reinforcing fibers, which has excellent designability and a smooth surface, and a method for manufacturing the molded article. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an example of a method for producing a molded article according to this embodiment. [Diagram 2]FIG. 2 is a schematic diagram illustrating reinforcing fiber A whose cross section is present on the surface of a molded article, a cross-sectional area a1 on the surface of the molded article, and an average cross-sectional area a2 of reinforcing fiber A in this embodiment. [Diagram 3] FIG. 3 is a schematic diagram of an example of a pattern on a molded body. [Figure 4] FIG. 4 is a schematic diagram of another example of the pattern of the molded body. [Diagram 5] FIG. 5 is a schematic diagram for explaining the cutting angle in this embodiment. [Figure 6] FIG. 6 is a photograph of the molded body molded in Example 1. [Figure 7] FIG. 7 is a photograph of the molded body molded in Example 2. [Figure 8] FIG. 8 is a photograph of the molded body molded in Example 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to the present embodiment. In this specification, the use of "to" means that the numerical values ​​before and after it are included as the lower limit and upper limit. In this specification, various physical properties and characteristic values ​​are those at 23° C. unless otherwise specified. In this specification, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended effect of the process is achieved. If the measurement methods, etc. described in the standards shown in this specification vary from year to year, they will be based on the standards as of January 1, 2023, unless otherwise stated. 1 to 4 are schematic diagrams or schematic illustrations, and the scales may not correspond to the actual scales.

[0009] The molded article of this embodiment is a molded article of a prepreg containing a resin and reinforcing fibers, and is characterized in that, when the cross-sectional area a1 of the reinforcing fibers A, the cross-section of which is present on the surface of the molded article, on the surface of the molded article is compared with the average cross-sectional area a2 of the reinforcing fibers A, the reinforcing fibers A satisfying a1>a2 occupy 50% or more of the molded article, and the region B occupies 10% or more of the surface area of ​​the molded article. A molded article having such a configuration has excellent design and a smooth surface.

[0010] First, the configuration of the molded body will be described while explaining the manufacturing method of the molded body of the present embodiment with reference to Figures 1 to 4. It goes without saying that the manufacturing method of the molded body and the molded body of the present embodiment are not limited to Figures 1 to 4. FIG. 1 is a schematic diagram showing an example of a method for producing a molded body of this embodiment. In FIG. 1(a), 1 is a prepreg containing a resin and a reinforcing fiber, and 2 is another film. In FIG. 1(a), the multiple prepregs 1 may be the same or different. The number of laminated prepregs is determined by the size of the desired molded body, etc., but is preferably 2 plies or more, more preferably 25 plies or more, and preferably 100 plies or less, more preferably 75 plies or less. Furthermore, in this embodiment, as shown in FIG. 1(a), another film 2 may be included between the prepregs 1. The other film 2 is a metal film C or a colored resin layer D, which further imparts design to the obtained molded body. The number of the other films 2 is appropriately determined depending on the pattern, but may be one sheet or two or more sheets. In addition, only one type of the other film 2 may be used, or two or more types may be used.

[0011] Next, the material (1, 2) shown in FIG. 1(a) is heated and pressed to form a heated and pressed body 3 (b). The heated and pressed body is usually in a rectangular parallelepiped shape (block shape). The heating temperature when forming the heated and pressed body is preferably the glass transition temperature of the resin + (40 to 200)°C or the melting point of the resin + (10 to 100)°C. The pressure when forming the heated and pressed body is preferably 0.1 to 10 MPa. It is preferable that the heated and pressed body 3 is molded so as to include as few voids as possible.

[0012] In this embodiment, the heated and pressed body 3 is cut (FIG. 1(c)). The heated and pressed body is preferably cut while rotating the cutting machine 4. In particular, when the heated and pressed body 3 is cut, the cutting angle is adjusted so that the cross section of the reinforcing fiber is cut into various shapes on the surface of the cut surface, resulting in beautiful patterns. The cutting is preferably performed using a 5-axis machine. A 5-axis machine is a machine that adds two rotational and tilting axes to the three linear axes XYZ. 5-axis machines are broadly classified into three types: table type, main shaft type, and mixed type. Note that 5 shown in FIG. 1(c) is a reference plane when cutting. For example, when cutting with a table-type 5-axis machine, the reference plane during cutting is the table surface, and when cutting with a main shaft type 5-axis machine, the reference plane is the surface including the main shaft that has the largest area of ​​the molded body to be obtained. In the case of a mixed type, the reference plane is the table surface. When a processing machine other than the above-mentioned processing machines is used, the horizontal plane is used as the reference plane in the most stable state when the obtained molded body is placed on the horizontal plane.

[0013] In this embodiment, the cutting process is performed so that, when comparing the cross-sectional area a1 of the reinforcing fiber A on the surface of the molded body with the average cross-sectional area a2 of the reinforcing fiber A, a1>a2 is satisfied, the reinforcing fiber A occupies 50% or more of the surface area of ​​the molded body, and the area B is 10% or more of the surface area of ​​the molded body. Here, the reinforcing fiber A whose cross-section is on the surface of the molded body, the cross-sectional area a1 of the reinforcing fiber A on the surface of the molded body, and the average cross-sectional area a2 of the reinforcing fiber A will be described with reference to FIG. 2. 2 is an enlarged schematic diagram showing a part of the molded body (machined molded body) of this embodiment, in which 6 indicates the molded body and A indicates the reinforcing fiber whose cross section is present on the surface of the molded body. In other words, the reinforcing fiber included in the molded body 6 but whose cross section is not present on the surface of the molded body does not correspond to the reinforcing fiber A. When the heated and pressurized body is cut, the cross section of the reinforcing fiber A appears on the surface of the molded body. When the cut cross section is cut at an angle, the cross section a1 becomes larger than the cross section a2 (usually the average cross section of the reinforcing fiber A) of the cross section cut in a direction perpendicular to the fiber length direction (a1>a2). By cutting the cross section of the reinforcing fiber A in this way, the cross section a1 of the reinforcing fiber A can impart various patterns to the surface of the molded body 6. Such patterns cannot be imparted to molded bodies such as injection molded bodies, and it becomes possible to impart the added value of rarity to the molded body 6. Here, cutting at an angle generally means that cutting is performed at an angle other than 90° with respect to a reference plane during cutting processing. Furthermore, if the cut surface is polished using an extremely fine abrasive after cutting, the reinforcing fibers A will not break and the cross-sectional area a1 of the reinforcing fibers A can be increased. Examples of the particle size of the abrasive include those with a D50 of 0.1 μm to 2 μm.

[0014] Returning to Fig. 1 again, in this embodiment, as described above, another film 2 may be included between the prepregs 1 (Fig. 1(a)). By including another film 2, a pattern derived from the other film 2 can also be imparted to the surface of the molded body 6 after cutting processing shown in Fig. 1(d). As a result, a molded body with even better design can be obtained.

[0015] In this embodiment, as described above, when the cross-sectional area a1 of the reinforcing fiber A present on the surface of the molded body is compared with the average cross-sectional area a2 of the reinforcing fiber A, it is preferable that the molded body includes a region B in which the reinforcing fiber A, where a1>a2, occupies 50% or more, and that region B occupies 10% or more of the surface area of ​​the molded body. Here, region B is determined by the following method, more specifically, according to the description of the examples described later. First, the surface of the molded body 6 is 2 The cross-sectional area of ​​the reinforcing fiber A observed on the surface is measured every 10,000 μm of the surface area of ​​the molded product. 2The cross-sectional areas of 100 reinforcing fibers A are measured every 100 minutes. The region where 50% or more of the measured cross-sectional area a1 of the reinforcing fibers A is larger than the average cross-sectional area a2 of the reinforcing fibers A is recognized as region B. In the molded body 6 in FIG. 1(d), the dome-shaped portion of the molded body 6 placed on the reference plane 5 of the cutting machine (not shown) corresponds to region B. Region B is usually a portion that has been cut at an angle.

[0016] Region B is preferably 20% or more of the surface area of ​​the molded body, more preferably 30% or more, more preferably 40% or more, and still more preferably 80%. This is because a molded body is usually used by joining or bonding with some other member, so it is economical to provide region B only in a visible portion. In addition, by making the proportion of region B a certain amount or more, the design can be further improved. In region B, ideally, all cross-sectional areas of the reinforcing fibers A are larger than the average cross-sectional area a2 of the reinforcing fibers A, but there may be some cross-sectional areas smaller than the average cross-sectional area a2 of the reinforcing fibers A. In this embodiment, the proportion of the reinforcing fibers A in region B where a1>a2 is preferably 60% or more, and more preferably 70% or more, of the cross-sections of the reinforcing fibers A in region B, and it is preferable that the cross-sections of all the reinforcing fibers A satisfy a1>a2 (100% or less).

[0017] The cross-sectional area a1 of the reinforcing fiber A on the surface of the molded body is the average value of the cross-sectional area a1 included in the region B, and is 51 μm 2 It is preferable that the thickness is 55 μm or more. 2 More preferably, it is 60 μm or more. 2 More preferably, it is 200 μm or more. 2 It is preferable that the thickness is less than 100 μm. 2 More preferably, it is 70 μm or less. 2 It may be the following. On the other hand, the average cross-sectional area a2 of the reinforcing fiber A is 20 μm 2 It is preferable that the thickness is 30 μm or more.2 More preferably, it is 40 μm or more. 2 More preferably, it is 100 μm or more. 2 Preferably, it is 60 μm or less. 2 It is more preferable that: Furthermore, the difference between the cross-sectional area a1 (average value) and the cross-sectional area a2 of the reinforcing fiber A in region B is 5 μm 2 It is preferable that the thickness is 7 μm or more. 2 More preferably, it is 10 μm or more. 2 More preferably, it is 200 μm or more. 2 It is preferable that the thickness is less than 150 μm. 2 It is more preferable that the thickness is less than 100 μm depending on the application. 2 Below, 80μm 2 Below, 50μm 2 Below, 20μm 2 It may be the following.

[0018] Fig. 3 shows a schematic diagram of an example of a pattern of the molded body of this embodiment. Fig. 3 is a view of the cut surface of the molded body viewed from a direction perpendicular to the reference plane. In Fig. 3, 6 is the molded body, and the concentric circles A is a cross section 2a derived from reinforcing fiber A, and 2 is a cross section derived from another film 2. As shown in Fig. 3, by appropriately adjusting the cutting angle, a complex pattern can be expressed by the cross section 2a derived from reinforcing fiber A, the part derived from the resin, and the part derived from the other film 2. Fig. 4 is a schematic diagram of another example of the pattern of the molded body of this embodiment. Fig. 4 is a diagram of the cut surface of the molded body viewed from a direction perpendicular to the reference plane. In Fig. 4, two concentric circles of the molded body 6 are drawn by the cross section originating from the reinforcing fiber A.

[0019] The size of the molded body of this embodiment can be appropriately set depending on the application. 3 It is preferable that the thickness is more than 1 cm. 3 More preferably, it should be 10 cm or more. 3 Preferably less than 5cm 3 It is more preferable that: Furthermore, the thickness of the thinnest part of the molded body of this embodiment is preferably 0.05 cm or more, more preferably 0.1 cm or more, and is preferably 10 cm or less, more preferably 5 cm or less, and even more preferably 1 cm or less.

[0020] Next, the cutting process will be described in detail. As shown in FIG. 1(c), the cutting step is a step of cutting the heated and pressurized body 3. The average cutting angle at this time is preferably 3° or more, more preferably 4° or more, even more preferably 6° or more, even more preferably 8° or more, and even more preferably 10° or more, relative to the reference plane. By setting the angle to the lower limit or more, it is possible to form a more finely patterned surface of the molded body. Furthermore, the average cutting angle is preferably 40° or less, more preferably 38° or less, even more preferably 36° or less, even more preferably 34° or less, and even more preferably 32° or less, relative to the reference plane. By setting the angle to the upper limit or less, it is possible to form a more vivid pattern on the surface of the molded body. The average cutting angle can be determined according to the description in the Examples section below.

[0021] The cutting temperature is preferably 50°C or higher, more preferably 55°C or higher, even more preferably 60°C or higher, even more preferably 65°C or higher, and even more preferably 70°C or higher. By setting the temperature at or above the lower limit, it is possible to improve the surface accuracy without impairing the cutting efficiency. In addition, the cutting temperature is preferably 100°C or lower, more preferably 95°C or lower, even more preferably 93°C or lower, even more preferably 91°C or lower, and even more preferably 88°C or lower. By setting the temperature at or below the upper limit, there is a tendency to more effectively suppress the resin from entangling with the tool during cutting. The cutting temperature here means the temperature of the cutting part (the actual blade, etc.) of the cutting machine after it has reached a steady state, and therefore does not include the temperature during the initial heating up or final cooling down of the cutting machine. The cutting process is preferably carried out in an atmosphere of 10 to 45° C. and a relative humidity of 5 to 50% or less.

[0022] Next, the prepreg and the heated and pressurized body used in this embodiment will be described in detail. As the prepreg used in this embodiment, any known prepreg can be used as long as it contains a resin and reinforcing fibers.

[0023] The prepreg in the present embodiment contains a resin. The resin may be a thermoplastic resin, a thermosetting resin, or a mixture of both, but is preferably a thermoplastic resin. An example of the resin of the prepreg in this embodiment is a resin containing a thermoplastic resin, and 90% by mass or more of the resin is a thermoplastic resin. Another example of the resin is a resin containing a thermosetting resin, and 90% by mass or more of the resin is a thermosetting resin. By using thermoplastic resins (and even crystalline thermoplastic resins), cutting work tends to be possible at higher temperatures. In addition, when using thermosetting resins, curing time is required, and the molding cycle tends to be longer.

[0024] The resin preferably has at least one of a melting point of 150°C to 330°C and a glass transition temperature of 100°C or higher. By setting the melting point and / or glass transition temperature to the above lower limit or higher, cutting tends to be easier. In particular, when cutting is performed vigorously, frictional heat is likely to be generated, so if the glass transition temperature is low, the resin becomes soft and cutting workability may be poor. Furthermore, by setting the melting point and / or glass transition temperature to be equal to or lower than the upper limit, the moldability of the heated and pressed body tends to become easier. The melting point of the resin (usually a thermoplastic resin) is preferably 150° C. or higher, more preferably 180° C. or higher, and preferably 360° C. or lower, more preferably 345° C. or lower, even more preferably 330° C. or lower, even more preferably 310° C. or lower, even more preferably 290° C. or lower, even more preferably 270° C. or lower, and particularly preferably 250° C. or lower. In particular, by using a resin having a melting point (a crystalline thermoplastic resin), cutting can be performed at a higher processing temperature. The glass transition temperature of the resin is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 100°C or higher, and is preferably 210°C or lower, more preferably 200°C or lower, even more preferably 190°C or lower, and even more preferably 185°C or lower.

[0025] The melting point (Tm) and glass transition temperature (Tg) of a resin are values ​​measured by differential scanning calorimetry (DSC) in accordance with ISO 11357. Measurements are performed using a differential scanning calorimeter, with the resin placed in the measurement pan of the differential scanning calorimeter and heated in a nitrogen atmosphere at a heating rate of 10°C / min to the melting point + 40°C for crystalline resins and to the glass transition temperature + 100°C for amorphous resins, to determine the glass transition temperature (Tg) and melting point (Tm). As the differential scanning calorimeter, a "DSC-60" manufactured by SHIMADZU CORPORATION is used.

[0026] The thermoplastic resin is not particularly limited, and preferred examples thereof include polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate resin, and polybutylene terephthalate resin; polyamide resin; polycarbonate resin; styrene-based resin; polyolefin resins such as polyethylene resin, polypropylene resin, and cyclic cycloolefin resin; polyacetal resin; polyimide resin; polyphenylene sulfide resin, polyether ether ketone resin (PEEK), polytetrafluoroethylene resin, polyvinyl chloride resin, polyetherimide resin; polyurethane resin; polyphenylene ether resin; polysulfone resin; polymethacrylate resin; and the like. It is preferable for the resin to contain at least one of polyamide resin, polycarbonate resin, polyimide resin, and polyether ether ketone resin, and it is more preferable for the resin to contain a polyamide resin.

[0027] The type of polyamide resin used in this embodiment is not particularly limited, and may be either an aliphatic polyamide resin or a semi-aromatic polyamide resin. Examples of the aliphatic polyamide resin include polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 610, polyamide 612, and polyamide 6 / 66, with polyamide 66 being preferred. The polyamide resin used in the present embodiment preferably contains a semi-aromatic polyamide resin. The semi-aromatic polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 20 to 80 mol % of the total structural units of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit are structural units containing an aromatic ring. By using such a semi-aromatic polyamide resin, the mechanical strength of the obtained molded article can be increased. Examples of the semi-aromatic polyamide resin include terephthalic acid-based polyamide resins (polyamide 6T, polyamide 9T, polyamide 10T) and xylylenediamine-based polyamide resins described later.

[0028] At least one of the polyamide resins used in the present embodiment contains diamine-derived structural units and dicarboxylic acid-derived structural units, and it is preferred that 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine, and 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. Hereinafter, such a polyamide resin may be referred to as a xylylenediamine-based polyamide resin. The diamine-derived constituent units of the xylylenediamine-based polyamide resin are more preferably 75 mol% or more, even more preferably 80 mol% or more, even more preferably 85 mol% or more, still more preferably 90 mol% or more, and even more preferably 95 mol% or more derived from xylylenediamine. The dicarboxylic acid-derived constituent units of the xylylenediamine-based polyamide resin are more preferably 75 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more derived from α,ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms.

[0029] Diamines other than metaxylylenediamine and paraxylylenediamine that can be used as the raw diamine component of the xylylenediamine-based polyamide resin include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine, 1,3-bis( Examples of the diamines include alicyclic diamines such as bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane; and diamines having an aromatic ring such as bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. These can be used alone or in combination of two or more.

[0030] Examples of α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms that are suitable for use as the raw dicarboxylic acid component of the xylylenediamine-based polyamide resin include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. One or a mixture of two or more of these can be used. Among these, adipic acid or sebacic acid are more preferred, and adipic acid is even more preferred, since the melting point of the polyamide resin falls within a range suitable for molding.

[0031] Examples of dicarboxylic acid components other than the above-mentioned α,ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, and isomers of naphthalenedicarboxylic acids such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. These can be used alone or in combination of two or more kinds.

[0032] In the xylylenediamine-based polyamide resin of this embodiment, it is preferable that 0 to 100 mol% of the diamine-derived structural units are derived from paraxylylenediamine and 100 to 0 mol% are derived from metaxylylenediamine, it is more preferable that 0 to 70 mol% are derived from paraxylylenediamine and 100 to 30 mol% are derived from metaxylylenediamine, it is even more preferable that 0 to 50 mol% are derived from paraxylylenediamine and 100 to 50 mol% are derived from metaxylylenediamine, and it is even more preferable that 0 to 20 mol% are derived from paraxylylenediamine and 100 to 80 mol% are derived from metaxylylenediamine. In addition, in the xylylenediamine-based polyamide resin of this embodiment, 70 mol % or more (preferably 80 mol % or more, more preferably 90 mol % or more) of the dicarboxylic acid-derived structural units are preferably derived from sebacic acid and / or adipic acid (preferably adipic acid). In any of the above embodiments, the total amount of constitutional units derived from diamines does not exceed 100 mol %, and the total amount of constitutional units derived from dicarboxylic acids does not exceed 100 mol %.

[0033] The xylylenediamine-based polyamide resin is mainly composed of diamine-derived structural units and dicarboxylic acid-derived structural units, but does not completely exclude other structural units, and may contain lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acid-derived structural units such as aminocaproic acid and aminoundecanoic acid. Here, the main component means that the total number of diamine-derived structural units and dicarboxylic acid-derived structural units is the largest among all structural units among the structural units constituting the xylylenediamine-based polyamide resin. In this embodiment, the total of diamine-derived structural units and dicarboxylic acid-derived structural units in the xylylenediamine-based polyamide resin preferably accounts for 90% by mass or more of all structural units, more preferably accounts for 95% by mass or more, and even more preferably accounts for 98% by mass or more.

[0034] Examples of the thermosetting resin include epoxy resin, phenol resin, (meth)acrylate resin, unsaturated polyester resin, diallyl dilate resin, cyanate resin, and maleimide resin, and epoxy resin is preferable.

[0035] The prepreg used in this embodiment may contain a resin additive within the scope of the present invention. Specifically, examples of the resin additive include additives such as coupling agents, reactive diluents, solvents, reactive diluents other than solvents, curing accelerators, wetting agents, tackifiers, defoamers, matting agents, rust inhibitors, lubricants, colorants, oxygen scavengers, ultraviolet absorbers, antioxidants, plasticizers, dispersants, flame retardants, antistatic agents, color inhibitors, and gelling inhibitors. The total amount of these is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less of the resin. These resin additives are usually mixed with the resin and then impregnated into the reinforcing fibers together with the resin.

[0036] The prepreg used in the present embodiment contains reinforcing fibers, which are preferably continuous reinforcing fibers. The shape of the reinforcing fiber includes flat reinforcing fibers called sheets, tapes, etc. Examples of flat reinforcing fibers that can be used in this embodiment include unidirectional materials (UD materials), woven fabrics, knitted fabrics, nonwoven fabrics, tailored fiber placement processed materials (TFP materials, meaning materials processed by tailored fiber placement), etc., and preferably include TFP materials and / or woven fabrics. Examples of woven fabrics include twill weave, plain weave, blind weave, and satin weave. In the flat reinforcing fiber used in this embodiment, the number of reinforcing fibers present per 1 inch x 1 inch area is 1 x 10 8 More than 1×10 is preferable. 9 More preferably, it should be 2×10 10 It is preferable that the number of strands is less than 1.7 × 10 10 By increasing the number of reinforcing fibers, the proportion of the reinforcing fibers on the surface of the molded article increases, making it possible to form a more complex and beautiful pattern.

[0037] In addition, when producing the above TFP material and / or flat reinforcing fibers such as woven fabric, a mixed fiber yarn may be used. The mixed yarn is, for example, a yarn containing continuous thermoplastic resin fibers and continuous reinforcing fibers, and the degree of dispersion of the continuous thermoplastic resin fibers and the continuous reinforcing fibers is 70% or more. By using such a mixed yarn, it is possible to more easily produce a regular pattern. The continuous thermoplastic resin fiber used in the mixed yarn is exemplified by the thermoplastic resin used in the prepreg described above in a fibrous form, and the range of preferred resins is also the same. The continuous thermoplastic resin fiber and the continuous reinforcing fiber used in the mixed yarn are preferably formed into a tape shape using a surface treatment agent and / or a sizing agent. For details of the mixed yarn, refer to the descriptions in JP 2015-98669 A and WO 2020 / 050156 A, the contents of which are incorporated herein by reference. The degree of dispersion of the mixed yarn is measured according to the description in paragraph 0073 of WO 2020 / 050156 A.

[0038] There is no particular restriction on the average fiber length of the reinforcing fibers, but from the viewpoint of molding processability, it is preferably 1 cm or more, more preferably 3 cm or more, and is preferably 1 m or less.

[0039] Examples of materials for the reinforcing fibers include inorganic fibers such as glass fibers, carbon fibers, metal fibers, boron fibers, basalt fibers, and ceramic fibers, and organic fibers such as aramid fibers, polyoxymethylene fibers, aromatic polyamide fibers, polyparaphenylene benzobisoxazole fibers, and ultra-high molecular weight polyethylene fibers. Among these, inorganic fibers are preferred from the viewpoint of obtaining high strength, and at least one selected from the group consisting of glass fibers, carbon fibers, and basalt fibers is more preferred because of its light weight, high strength, and high elastic modulus, and carbon fibers are even more preferred. Examples of carbon fibers include polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, etc. Carbon fibers made from plant-derived raw materials such as lignin and cellulose can also be used.

[0040] The reinforcing fibers used in this embodiment may be treated with a treatment agent. Examples of the treatment agent include a surface treatment agent and a sizing agent. The surface treatment agent is preferably a silane coupling agent, such as a silane coupling agent having a vinyl group, a silane coupling agent having an amino group, a silane coupling agent having an epoxy group, a silane coupling agent having a (meth)acrylic group, or a silane coupling agent having a mercapto group.

[0041] Examples of the sizing agent include urethane-based sizing agents, epoxy-based sizing agents, acrylic-based sizing agents, polyester-based sizing agents, vinyl ester-based sizing agents, polyolefin-based sizing agents, polyether-based sizing agents, and carboxylic acid-based sizing agents, and among these, one or more of them can be used in combination. Examples of the sizing agent that combines two or more kinds include urethane / epoxy-based sizing agents, urethane / acrylic-based sizing agents, and urethane / carboxylic acid-based sizing agents.

[0042] Among the above, from the viewpoint of improving the interfacial adhesion with the resin, it is preferable that the reinforcing fibers are treated with one or more selected from the group consisting of a urethane-based sizing agent, an epoxy-based sizing agent, and a urethane / epoxy-based sizing agent, and it is more preferable that the reinforcing fibers are treated with an epoxy-based sizing agent.

[0043] Commercially available reinforcing fibers can also be used. Examples of commercially available reinforcing fibers include Toray Industries, Inc.'s Torayca yarns "T300", "T300B", "T400HB", "T700SC", "T800SC", "T800HB", "T830HB", "T1000GB", "T100GC", "M35JB", "M40JB", "M46JB", "M50JB", "M55J", "M55JB", "M60JB", "M30SC", and "Z600" series, Torayca cloths "CO6142", "CO6151B", "CO6343", "CO6343B", "CO6347B", "CO6644B", "CK6244C", "CK6273C", "CK6261C", "UT70" series, "UM46" series, and "BT70" series.

[0044] The proportion of reinforcing fibers in the prepreg used in this embodiment is preferably 40% by volume or more, more preferably 42% by volume or more, even more preferably 43% by volume or more, even more preferably 44% by volume or more, and even more preferably 45% by volume or more. By making it equal to or more than the lower limit, it tends to be easier to achieve both excellent mechanical properties and maintaining a preferable temperature during cutting. In addition, the proportion of reinforcing fibers in the prepreg used in this embodiment is preferably 80% by volume or less, more preferably 78% by volume or less, even more preferably 76% by volume or less, even more preferably 74% by volume or less, and even more preferably 72% by volume or less. By making it equal to or less than the upper limit, a molded body with fewer voids can be obtained, and the falling off of reinforcing fibers during cutting tends to be more effectively suppressed. The prepreg used in the present embodiment may contain only one type of reinforcing fiber, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0045] The total amount of resin and reinforcing fibers in the prepreg used in this embodiment is preferably 90 mass % or more, more preferably 95 mass % or more, and even more preferably 99 mass % or more, with the upper limit being 100 mass %.

[0046] In this embodiment, the difference between the refractive index of the resin and the refractive index of the reinforcing fiber at a wavelength of 589 nm is preferably 0.05 or more, more preferably 0.06 or more, even more preferably 0.07 or more, even more preferably 0.08 or more, and even more preferably 0.1 or more. By making it equal to or greater than the lower limit, it is possible to express a more vivid and beautiful pattern. In addition, the difference in refractive index may be, for example, 1 or less, or even 0.9 or less, 0.8 or less, 0.7 or less, or 0.6 or less. The difference in refractive index is particularly effective when the resin is an amorphous resin. The refractive index is measured in accordance with JIS K7142:2014.

[0047] The prepreg can be produced according to a known method, for example, by impregnating a mixture of a resin and a resin additive added as required into a reinforcing fiber (usually a reinforcing fiber substrate) and solidifying or semi-curing the resin. It is preferable that the prepreg contains as few voids as possible, because by preventing the inclusion of voids, a molded article with a better appearance can be obtained.

[0048] The heated and pressed body in this embodiment is a molded body obtained by heating and pressing two or more plies of the prepreg. The molded body in this embodiment is usually formed by cutting such a heated and pressed body. The thickness of the hot and pressed body is preferably 1 mm or more, more preferably 3 mm or more, even more preferably 5 mm or more, even more preferably 8 mm or more, and even more preferably 9 mm or more. By making it equal to or more than the lower limit, the cutting temperature tends to be stable. In addition, the thickness of the hot and pressed body is preferably 30 mm or less, more preferably 25 mm or less, even more preferably 20 mm or less, even more preferably 18 mm or less, and even more preferably 16 mm or less. By making it equal to or less than the upper limit, it is easier to express a pattern with excellent appearance. In this embodiment, the thickness of the hot and pressed body may be the same in all parts, or may have some thick parts or thin parts. In this embodiment, it is preferable that the thickness of the hot and pressed body at the part having the largest volume of the part to be cut is within the above range.

[0049] The molded body of this embodiment may include other films, and a part of the other films may be present on the surface of the molded body. Examples of the other films include a metal film C and / or a colored resin layer D. By providing such other films, the design of the molded body can be further improved. As described above, the other films can be sandwiched between prepregs to mold the heated and pressurized body, and then cut to give the surface a design. An example of the metal film C is a gold foil. The colored resin film D may be a film formed by mixing a dye and / or pigment with a resin, or a resin film colored with a dye and / or pigment. The glass transition temperature of the colored resin film D is preferably within ±20°C of the glass transition temperature of the resin contained in the prepreg. Examples of the resin used for the colored resin film D include polyester resin, polycarbonate resin, and acrylic resin, with polyester resin being preferred. The thickness of the other films is not particularly limited, but is preferably 10 μm or more and 10 μm or less. When other films are provided, the number thereof is preferably one or less for two plies of prepregs, and more preferably one or less for three plies of prepregs.

[0050] The molded article of the present embodiment has excellent design properties, and furthermore, can be made into a resin molded article that is lightweight and has excellent strength, and therefore can be used for various decorative items, automobile interiors, aircraft interiors, portable electrical and electronic devices, wearable electrical and electronic devices, accessories, watches, glasses, shoes, bags, cases, helmets, kitchen utensils, furniture, etc. EXAMPLES

[0051] The present invention will be described in more detail below with reference to examples. The materials, amounts, ratios, processing contents, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0052] raw material Thermoplastic resin 1: Polyamide resin (MXD6) synthesized from metaxylylenediamine and adipic acid, manufactured by Mitsubishi Gas Chemical Company, Inc., product number: 6001, melting point: 237°C, glass transition temperature: 85°C, refractive index at wavelength 589 nm: 1.58 Thermoplastic resin 2: polycarbonate resin, manufactured by Mitsubishi Engineering Plastics Corporation, product number: S-3000FN, glass transition temperature: 146°C, refractive index at wavelength 589 nm: 1.59 Thermoplastic resin 3: Thermoplastic polyimide resin (TPI). A thermoplastic polyimide resin was synthesized according to Example 1 of paragraph 0128 of WO 2016 / 147996. The physical properties of the obtained resin were as follows: melting point: 323°C, glass transition temperature: 185°C, refractive index at a wavelength of 589 nm: 1.52 Thermoplastic resin 4: Polyetheretherketone (PEEK), manufactured by Victrex, product number: 150G, melting point: 343°C, refractive index at wavelength 589 nm: 1.53 Thermosetting resin 1: Epoxy resin, manufactured by Nitto Denko Corporation, product number: NT-8500P, glass transition temperature: 130°C, refractive index at wavelength 589 nm: 1.56

[0053] Reinforced fiber 1 (CF1, for manufacturing TFP tow): Carbon fiber, manufactured by Toyo Rayon Co., Ltd., product number: T700SC-12000, refractive index at wavelength 589 nm: 2.01 Reinforced fiber 2 (CF2, twill weave): Carbon fiber, manufactured by Toyo Rayon Co., Ltd., product number: CO6347B 3K, refractive index at wavelength 589 nm: 2.01 Reinforced fiber 3 (CF3, cord weave): Carbon fiber, manufactured by Mitsubishi Chemical Corporation, product number: TRK979PQRW, refractive index at wavelength 589 nm: 2.01

[0054] Colored resin film 1: Polyester film adhesive tape, manufactured by Teraoka Seisakusho Co., Ltd., product number: No. 631S #25 Red

[0055] The average cross-sectional area a2 of the reinforcing fiber was calculated by measuring the cross-sectional area at 100 points on the cross section of the reinforcing fiber, and excluding the top 10% and bottom 10% of the values. The unit is μm 2 As shown in.

[0056] Example 1 <Production of base prepreg (fiber reinforced plastic (TFP))> Using the above thermoplastic resin 1 and reinforcing fiber 1, a mixed yarn was produced so that Vf was 46% according to the description in paragraphs 0089 and 0090 of JP 2015-98669 A. Thermoplastic resin 1 was melt-extruded to produce a film having a thickness of 50 μm. The mixed yarn obtained above was aligned in one direction on the film using a Tailored Fiber Placement device (manufactured by TISM) to obtain a prepreg. The stop yarn used in the placement was a multifilament of thermoplastic resin 1 obtained by the method described in paragraph 0089 of JP2015-98669A.

[0057] <Production of Molded Body by Heat and Pressurization> The prepregs obtained above were laminated alternately at 0° / 90° to the desired thickness, and then hot-pressed in a mold to produce a heated and pressed body before cutting. The pressing conditions were as follows: Thermoplastic resin 1: maximum temperature 260°C, pressing pressure 3.0MPa, Thermoplastic resin 2: maximum temperature 280°C, pressing pressure 3.0MPa, Thermoplastic resin 3: 345°C, pressing pressure 3.0MPa, Thermoplastic resin 4: 380°C, pressing pressure 3.0MPa, Thermosetting resin 1: 130°C, pressing pressure 0.1MPa. Here, 0° means the direction of the warp yarns.

[0058] <Cutting method> The heated and pressed body obtained above was cut using a 5-axis cutting machine (Hitachi Seiko, product number: 2MF-V) at the cutting angle and cutting temperature shown in Table 1 or Table 2. The cutting machine was used in an atmosphere of 23°C and a relative humidity of 30%. The total cutting area was 2500 mm 2 The rotation speed of the 5-axis machining center was set to 645 rpm. The cutting angle θ was set for the five-axis machining center as shown in Table 1.

[0059] FIG. 5 shows a schematic diagram for explaining the definition of the cutting angle θ. FIG. 5(a) is a view of the hot and pressurized body 3 as seen from the side with the reference surface 5 (table surface) facing downward. FIG. 5(b) is a view of the hot and pressurized body 3 as seen from 90° away from FIG. 5(a) with the reference surface 5 facing downward. FIG. 5(c) is a view of the hot and pressurized body 3 as seen from directly above (as seen from the direction opposite the reference surface). In FIG. 5, the shaded parts of the hot and pressurized body 3 are the parts to be cut, and the remaining parts are the parts that remain as the molded body 6. Point p in FIGS. 5(a) to (c) 1 , p 2 , p 3 Based on this, θ 1 , θ 2 was calculated, and the average value was taken as the cutting angle θ.

[0060] <Measurement of the proportion of area B> The cross-sectional area of ​​the reinforcing fibers observed on the surface of the obtained cut molded body was measured. 2 The cross-sectional areas of 100 reinforcing fibers were measured every 100 seconds. A region in which 50% or more of the measured cross-sectional area a1 of the reinforcing fibers was larger than the average cross-sectional area a2 of the reinforcing fibers was identified as region B. The average value of the cross-sectional area a1 in region B was calculated. Moreover, the ratio of the area of ​​region B to the surface area of ​​the molded article was calculated (unit: %).

[0061] <Design> The cut surface of the obtained molded body was visually evaluated for design. The evaluation was based on a comprehensive assessment of the clarity and sophistication of the pattern, with Example 8 being rated as B (standard), those that were clearer and more sophisticated than Example 8 being rated as A, and those that were less clear and less sophisticated than Example 8 being rated as C. Additionally, those that had no pattern were rated as D. The evaluation was carried out by 10 experts, and judged by majority vote.

[0062] <Workability> The ease of machining during the above cutting process was evaluated. A:Good B: Other than A and C above (machining is possible, but resin tends to get tangled in the end mill, etc.) C: Processing is not possible

[0063] <Molding cycle> The time required for cutting was measured. The shorter the time required for cutting, the better the molding cycle. A: Less than 1 hour B: 1 hour or more but less than 3 hours C: More than 3 hours

[0064] Example 2 Using the thermoplastic resin shown in Table 1, a film shown in Table 1 was obtained using an extrusion molding machine at a melting point of +30°C. This was laminated with reinforcing fiber 2, one colored resin film 1 was sandwiched every 5 ply, and a prepreg was obtained by hot press molding. The rest was the same as in Example 1.

[0065] Example 3 Using the thermoplastic resin shown in Table 1, a film shown in Table 1 was obtained using an extrusion molding machine at a melting point of +30°C. This was laminated with reinforcing fiber 3, one colored resin film 1 was sandwiched every 5 ply, and a prepreg was obtained by hot press molding. The rest was the same as in Example 1.

[0066] Example 4 The same procedure as in Example 1 was carried out except that the conditions shown in Table 1 were changed.

[0067] Example 5 The same procedure as in Example 1 was carried out except that the conditions shown in Table 1 were changed.

[0068] Example 6 The same procedure as in Example 1 was carried out except that the conditions shown in Table 2 were changed.

[0069] Example 7 A prepreg was obtained by impregnating a suitable amount of the thermosetting resin 1 into the reinforcing fiber 2 by a hand lay-up method at 40° C. The same procedure as in Example 1 was carried out except that the obtained prepreg was used and the conditions shown in Table 2 were changed.

[0070] Example 8 The same procedure as in Example 1 was carried out except that the conditions shown in Table 2 were changed.

[0071] Example 9 The same procedure as in Example 1 was carried out except that the conditions shown in Table 2 were changed.

[0072] Comparative Example 1 A mold was prepared to directly mold the molded article obtained in Example 1. The prepreg was cut to fit the dimensions of the mold, placed in the mold, and molded at 260°C and a press pressure of 3.0 MPa. A molded article of the desired shape was obtained without cutting. The average value of the cross-sectional area a1 in the region B is the ratio of the reinforcing fibers A at both ends of the heated and pressed body.

[0073] The results are shown in the following Tables 1 and 2. For Examples 1 to 3, photographs after cutting are shown in Figures 6 to 8, respectively.

[0074] [Table 1]

[0075] [Table 2]

[0076] As is clear from the above results, the present invention provides a molded article containing a resin and reinforcing fibers, which has excellent design and a smooth surface. It also has excellent processability and molding cycle. [Explanation of symbols]

[0077] 1 Prepreg 2. Other membranes 3. Heat and pressure 4 Cutting machine 5 Reference plane 6 Molded body

Claims

1. A prepreg molding containing resin and reinforcing fibers, Among the reinforcing fibers, when the cross-sectional area a1 of the reinforcing fiber A, the cross-section of which is present on the surface of the molded body, is compared with the average cross-sectional area a2 of the reinforcing fiber A, a1>a2 is satisfied, and a region B is included in which the reinforcing fiber A occupies 50% or more, The region B occupies 10% or more of the surface area of ​​the molded body.

2. The molded article according to claim 1 , wherein the resin comprises a thermoplastic resin.

3. The molded article according to claim 1 or 2, wherein the resin satisfies at least one of a melting point of 150° C. or more and 330° C. or less and a glass transition temperature of 100° C. or more.

4. The molded body according to claim 1 or 2, wherein the molded body includes a metal film C, and a portion of the metal film C is present on a surface of the molded body.

5. The molded article according to claim 1 or 2, wherein the molded article includes a colored resin film D, and a part of the colored resin film D is present on a surface of the molded article.

6. The molded body according to claim 1 or 2, wherein the proportion of reinforcing fibers in the prepreg is 40 to 80% by volume.

7. The molded article according to claim 1 or 2, wherein a difference between a refractive index of the resin and a refractive index of the reinforcing fiber at a wavelength of 589 nm is 0.05 or more.

8. The difference between the cross-sectional area a1 and the cross-sectional area a2 in the region B of the reinforcing fiber A is 5 μm ２ The molded article according to claim 1 or 2.

9. The molded article according to claim 1 or 2, wherein the reinforcing fibers constituting the prepreg include a tailored fiber placement processed material and / or a woven fabric.

10. The molded article according to claim 1 or 2, wherein the region B is 20 to 80% of the surface area of ​​the molded article.

11. A method for producing a molded body, comprising cutting a heated and pressurized body obtained by stacking two or more plies of prepregs containing resin and reinforcing fibers, The cutting process is carried out in such a way that, when a cross-sectional area a1 of reinforcing fiber A, the cross-section of which is present on the surface of the molded body, on the surface of the molded body is compared with an average cross-sectional area a2 of the reinforcing fiber A, a1>a2 is satisfied, and the reinforcing fiber A occupies 50% or more of the surface area of ​​the molded body, and the region B is 10% or more of the surface area of ​​the molded body.

12. The method for producing a molded product according to claim 11, wherein the cutting process is performed using a five-axis machining center.

13. The method for producing a molded product according to claim 11 or 12, wherein a cutting angle θ when performing the cutting process is 3 to 40° with respect to a reference plane.

14. The method for producing a molded product according to claim 11 or 12, wherein the cutting temperature during the cutting process is 50 to 100° C.

15. The method for producing a molded article according to claim 11 or 12, wherein the molded article is the molded article according to claim 1 or 2.

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