Thermosetting resin composition, method for producing thermosetting resin composition, molded article, and method for producing molded article

Abstract

To provide a thermosetting resin composition that is less likely to impair the appearance and impact strength of a molding.SOLUTION: A thermosetting resin composition contains a first thermosetting resin material (A1) and further contains a pulverized product (B) of a second thermosetting resin material (A2) that has been cured. The pulverized product (B) has a 90% particle size of 300 μm or less, and the percentage of the pulverized product (B) to the thermosetting resin composition is 10.0 mass% or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure generally relates to a thermosetting resin composition, a method for producing a thermosetting resin composition, a molded article, and a method for producing a molded article, and more particularly, to a thermosetting resin composition containing a thermosetting resin material, a method for producing the thermosetting resin composition, a molded article produced by thermally curing the thermosetting resin composition, and a method for producing the molded article. [Background technology]

[0002] Patent Document 1 discloses a thermosetting resin molding material produced by crushing sprues, runners, or molding defects that are generated when molding a thermosetting resin molding material, adding the crushed material to a molding material raw material, and kneading without heating. Patent Document 1 further describes that sprues, runners, and molding defects have traditionally been discarded as unnecessary material, but by powdering and blending them, a molding material with the desired flow characteristics can be obtained without kneading while heating as in roll kneading, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-124949 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the inventor's research, when a molded article is produced from a material containing pulverized thermosetting resin material as disclosed in Patent Document 1, the appearance and impact strength of the molded article may be impaired.

[0005] An object of the present disclosure is to provide a thermosetting resin composition that can be used to produce a molded article and that contains a cured product of a thermosetting resin material while not impairing the appearance and impact strength of the molded article; a method for producing this thermosetting resin composition; a molded article produced by thermally curing this thermosetting resin composition; and a method for producing this molded article. [Means for solving the problem]

[0006] The thermosetting resin composition according to one embodiment of the present disclosure is a thermosetting resin composition containing a first thermosetting resin material (A1) and further containing a pulverized product (B) of a cured product of a second thermosetting resin material (A2). The 90% particle size of the pulverized product (B) is 300 μm or less. The percentage of the pulverized product (B) relative to the thermosetting resin composition is 10.0 mass% or less.

[0007] A method for producing a thermosetting resin composition according to one embodiment of the present disclosure is a method for producing the thermosetting resin composition, and includes a mixing step of mixing the first thermosetting resin material (A1) and the pulverized material (B).

[0008] A molded article according to one embodiment of the present disclosure contains a cured product of the thermosetting resin composition.

[0009] In the method for producing a molded article according to one embodiment of the present disclosure, the thermosetting resin composition is thermally cured to produce a molded article. Effect of the Invention

[0010] According to one aspect of the present disclosure, it is possible to provide a thermosetting resin composition that can be used to produce a molded article and that contains a cured product of a thermosetting resin material while not impairing the appearance and impact strength of the molded article; a method for producing this thermosetting resin composition; a molded article produced by thermally curing this thermosetting resin composition; and a method for producing this molded article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described. Note that the present disclosure is not limited to the following embodiments. The following embodiments are merely a part of various embodiments of the present disclosure, and various modifications are possible depending on the design as long as the object of the present disclosure can be achieved.

[0012] The thermosetting resin composition according to one embodiment of the present disclosure includes a first thermosetting resin material (A1) and further includes a pulverized product (B) of a cured product of a second thermosetting resin material (A2). The 90% particle size of the pulverized product (B) is 300 μm or less. The percentage of the pulverized product (B) relative to the thermosetting resin composition is 10.0 mass% or less.

[0013] According to this embodiment, even though the thermosetting resin composition contains the pulverized material (B), the appearance and impact strength of a molded article produced by curing the thermosetting resin composition are unlikely to be impaired.

[0014] A more specific configuration of the thermosetting resin composition according to this embodiment will be described.

[0015] As described above, the thermosetting resin composition contains the pulverized product (B) of the first thermosetting resin material (A1) and the cured product of the second thermosetting resin material (A2).

[0016] The first thermosetting resin material (A1) contains, for example, a thermosetting resin (a1) (hereinafter also referred to as the first thermosetting resin (a1)).

[0017] The first thermosetting resin (a1) contains at least one selected from the group consisting of a monomer, an oligomer, and a prepolymer. The first thermosetting resin (a1) may contain a base agent and a curing agent that reacts with the base agent.

[0018] The first thermosetting resin (a1) will be described in detail later.

[0019] The first thermosetting resin (a1) may be partially crosslinked. In this case, the appearance and impact strength of the molded product made from the thermosetting resin composition are less likely to be impaired. It is presumed that this is because the first thermosetting resin material (A1) containing the partially crosslinked first thermosetting resin (a1) can prevent the dispersibility of the pulverized material (B) of the cured product of the second thermosetting resin material (A2) in the thermosetting resin composition from decreasing when the thermosetting resin composition is molded. The reason why the dispersibility of the pulverized material (B) is less likely to decrease is that if the first thermosetting resin (a1) contained in the first thermosetting resin material (A1) is partially crosslinked, the melt viscosity of the thermosetting resin composition is less likely to decrease excessively when the thermosetting resin composition is heated and molded, and therefore, the thermosetting resin composition becomes more likely to flow while maintaining the state in which the pulverized material (B) is uniformly dispersed and incorporated in the thermosetting resin composition.

[0020] The first thermosetting resin material (A1) may contain at least one selected from the group consisting of a filler and other additives.

[0021] The filler is contained to satisfy the required characteristics of the molded article. The filler may contain at least one selected from the group consisting of organic substances such as wood flour, walnut shell powder, pulp, cotton flock, and soybean flour, and inorganic substances such as talc, mica, barium sulfate, diatomaceous earth, calcium carbonate, clay, and glass fiber. The filler can be appropriately blended in an optimal amount according to the required performance of the molded article, such as impact strength or linear expansion coefficient, and is not limited to a certain value.

[0022] The additive contains at least one selected from the group consisting of, for example, a plasticizer, a lubricant, a colorant, and the like.

[0023] The melt viscosity of the first thermosetting resin material (A1) is preferably 100 Pa·s or more and 5000 Pa·s or less. If the melt viscosity of the first thermosetting resin material (A1) is 100 Pa·s or more, the appearance and impact strength of the molded product made from the thermosetting resin composition are not easily impaired. This is presumably because, if the melt viscosity of the first thermosetting resin material (A1) is 100 Pa·s or more, the dispersibility of the pulverized material (B) of the cured product of the second thermosetting resin material (A2) in the thermosetting resin composition is not easily reduced when the thermosetting resin composition is molded. The reason why the dispersibility of the pulverized material (B) is not easily reduced is thought to be because, when the melt viscosity of the first thermosetting resin material (A1) is adjusted to 100 Pa·s or more, the thermosetting resin composition is easily flowable while maintaining the state in which the pulverized material (B) is uniformly dispersed and incorporated in the thermosetting resin composition when the thermosetting resin composition is heated and molded. The melt viscosity of the first thermosetting resin material (A1) is adjusted, for example, by the degree of partial crosslinking of the first thermosetting resin (a1). If the melt viscosity of the first thermosetting resin material (A1) is 5000 Pa·s or less, the flowability of the thermosetting resin composition is improved when the thermosetting resin composition is molded, so that moldability is less likely to be impaired. The melt viscosity of the first thermosetting resin material (A1) is adjusted, for example, by the degree of partial crosslinking of the thermosetting resin (a1). The melt viscosity of the first thermosetting resin material (A1) is more preferably 200 Pa·s or more. The melt viscosity of the first thermosetting resin material (A1) is more preferably 2000 Pa·s or less.

[0024] The melt viscosity of the first thermosetting resin material (A1) is measured using a flow tester (manufactured by Shimadzu Corporation). The measurement conditions for the melt viscosity of the first thermosetting resin material (A1) are a temperature of 150° C. and a load of 450 kgf, and the melt viscosity is measured when passing through a nozzle of Φ1.0×10 mm.

[0025] The second thermosetting resin material (A2) contains, for example, a thermosetting resin (a2) (hereinafter also referred to as a second thermosetting resin (a1)).

[0026] The second thermosetting resin (a2) contains at least one selected from the group consisting of a monomer, an oligomer, and a prepolymer. The second thermosetting resin (a2) may contain a base agent and a curing agent that reacts with the base agent.

[0027] The second thermosetting resin (a2) will be described in detail later.

[0028] The second thermosetting resin material (A2) may contain at least one selected from a filler and other additives.

[0029] The filler is contained to satisfy the required properties of the molded article. The filler may contain at least one selected from the group consisting of organic substances such as wood flour, walnut shell powder, pulp, cotton flock, and soybean flour, and inorganic substances such as talc, mica, barium sulfate, diatomaceous earth, calcium carbonate, clay, and glass fiber. The filler can be appropriately blended in an optimal amount according to the required performance of the molded article, such as impact strength or linear expansion coefficient, and is not limited to a certain value.

[0030] The additive contains at least one selected from the group consisting of, for example, a plasticizer, a lubricant, a colorant, and the like.

[0031] As described above, the 90% particle size (D90) of the pulverized material (B) is 300 μm or less. When the 90% particle size (D90) of the pulverized material (B) is 300 μm or less, the appearance and impact strength of a molded article made from the thermosetting resin composition are less likely to be impaired. The 90% particle size (D90) is the particle size at an integrated fraction of 90% in a particle size distribution obtained from a particle size distribution measurement result by a laser diffraction / scattering method, with the ordinate representing the integrated fraction and the abscissa representing the particle size. The 90% particle size (D90) of the pulverized material (B) is preferably 190 μm or less. The 90% particle size (D90) of the pulverized material (B) is preferably 90 μm or more. In this case, it is preferable from the viewpoint of productivity when producing a molded article.

[0032] The 50% particle size (D50) of the pulverized material (B) is preferably 250 μm or less. If the 50% particle size (D50) of the pulverized material (B) is 250 μm or less, the appearance and impact strength of a molded article made from the thermosetting resin composition are less likely to be impaired. The 50% particle size (D50) is the particle size at an integrated fraction of 50%, i.e., the median diameter, in a particle size distribution obtained from a particle size distribution measurement result by a laser diffraction / scattering method, in which the vertical axis is the integrated fraction and the horizontal axis is the particle size. The 50% particle size (D50) of the pulverized material (B) is preferably 115 μm or less. The 50% particle size (D50) of the pulverized material (B) is preferably 60 μm or more. In this case, it is preferable from the viewpoint of productivity when producing a molded article.

[0033] As described above, the percentage of the pulverized product (B) of the cured product of the second thermosetting resin material (A2) relative to the thermosetting resin composition is 10.0% by mass or less. Therefore, the appearance and impact strength of a molded product made from the thermosetting resin composition are less likely to be impaired. The percentage of the pulverized product (B) of the cured product of the second thermosetting resin material (A2) is preferably 5.0% by mass or less. The percentage of the pulverized product (B) of the cured product of the second thermosetting resin material (A2) is preferably 0.1% by mass or more in order to promote the reuse of waste materials.

[0034] Each of the first thermosetting resin (a1) and the second thermosetting resin (a2) preferably contains at least one resin selected from the group consisting of, for example, urea resin, melamine resin, phenol resin, melamine phenol resin, unsaturated polyester resin, urethane resin, and epoxy resin. In this case, the appearance and impact strength of a molded product made from the thermosetting resin composition are less likely to be impaired. The types of resins contained in each of the first thermosetting resin (a1) and the second thermosetting resin (a2) are not limited to those mentioned above.

[0035] As described above, each of the first thermosetting resin (a1) and the second thermosetting resin (a2) contains at least one selected from the group consisting of a monomer, an oligomer, and a prepolymer. For example, the epoxy resin contains at least one selected from the group consisting of a monomer, an oligomer, and a prepolymer having an epoxy group. The urea resin contains at least one selected from the group consisting of a monomer containing urea and formaldehyde, and an oligomer and a prepolymer formed by polymerization of this monomer. The melamine resin contains at least one selected from the group consisting of a monomer containing melamine and formaldehyde, and an oligomer and a prepolymer formed by polymerization of this monomer.

[0036] The type of resin contained in the first thermosetting resin (a1) and the type of resin contained in the second thermosetting resin (a2) may be the same or different. It is preferable that the type of resin contained in the first thermosetting resin (a1) and the type of resin contained in the second thermosetting resin (a2) are the same. In this case, the appearance and impact strength of the molded product made from the thermosetting resin composition are less likely to be impaired.

[0037] Each of the thermosetting resins (a1) and (a2) preferably contains an amino resin. That is, each of the thermosetting resins (a1) and (a2) preferably contains at least one of a melamine resin and a urea resin. In this case, the mechanical strength, electrical properties, water resistance, chemical resistance, and other properties of the molded product tend to be good.

[0038] It is particularly preferred that the thermosetting resin (a1) contains at least one of a urea resin and a melamine resin, and the first thermosetting resin (a1) is partially crosslinked. In this case, the effect of the first thermosetting resin (a1) being partially crosslinked is particularly likely to be exhibited. That is, the appearance and impact strength of the molded product are particularly unlikely to be impaired. This is presumably because, when the first thermosetting resin material (A1) contains at least one of a non-crosslinked urea resin and a melamine resin, the first thermosetting resin material (A1) contains unreacted monomers such as formaldehyde, and therefore the melt viscosity of the first thermosetting resin material (A1) is low, but when the first thermosetting resin material (A1) contains at least one of a partially crosslinked urea resin and a melamine resin, the melt viscosity of the first thermosetting resin material (A1) is increased, and the pulverized material (B) is significantly more likely to be dispersed in the thermosetting resin composition.

[0039] The components and the mixing ratios of the components contained in the first thermosetting resin material (A1) and the components and the mixing ratios of the components contained in the second thermosetting resin material (A2) may be the same, in which case the appearance and impact strength of a molded article made from the thermosetting resin composition are less likely to be impaired.

[0040] The method for producing the thermosetting resin composition will now be described in detail.

[0041] In this embodiment, the method for producing a thermosetting resin composition includes a mixing step of mixing the first thermosetting resin material (A1) with the pulverized material (B). Therefore, even if the thermosetting resin composition contains the pulverized material (B), the appearance and impact strength of the molded product produced by thermally curing the thermosetting resin composition are not easily impaired.

[0042] To produce the thermosetting resin composition, for example, first, a first thermosetting resin material (A1) and a pulverized product (B) of a cured product of the second thermosetting resin material (A2) are prepared.

[0043] As described above, the first thermosetting resin material (A1) contains, for example, a thermosetting resin (a1).

[0044] As described above, the thermosetting resin (a1) may be partially crosslinked. For example, by mixing the thermosetting compound, which is the raw material of the thermosetting resin (a1), while heating, the thermosetting compound is partially reacted to obtain the partially crosslinked thermosetting resin (a1). Not all of the thermosetting compounds may be reacted, that is, the thermosetting resin (a1) may contain unreacted thermosetting compounds. The thermosetting compound contains, for example, a base agent and a curing agent that reacts with the base agent. For example, when the thermosetting resin (a1) contains a urea resin, the thermosetting compound contains urea as a base agent and contains formaldehyde as a curing agent. The conditions of the heating and mixing are appropriately adjusted so that the first thermosetting resin material (A1) has a desired melt viscosity. When the thermosetting resin (a1) contains a melamine resin, the thermosetting compound contains melamine as a base agent and contains formaldehyde as a curing agent. The conditions for heating and mixing are appropriately adjusted so that the first thermosetting resin material (A1) has a desired melt viscosity.

[0045] As described above, the first thermosetting resin material (A1) may contain at least one of a filler and other additives. In this case, the mixture obtained by mixing the thermosetting compound with at least one of the filler and other additives may be heated and kneaded. Also, at least one of the filler and other additives may be mixed into the thermosetting resin (a1) obtained by heating and kneading the thermosetting compound.

[0046] The first thermosetting resin material (A1) is preferably granular. That is, it is preferable to prepare a granular first thermosetting resin material (A1). Therefore, it is preferable to pulverize the first thermosetting resin material (A1) into granular form before the mixing step. When pulverizing the first thermosetting resin material (A1), a pulverizer or the like is used. The pulverizer is, for example, selected from the group consisting of a roller mill, a jet mill, a hammer mill, and the like.

[0047] As described above, the second thermosetting resin material (A2) contains, for example, the thermosetting resin (a2), and further contains at least one of a filler and other additives, as necessary.

[0048] The second thermosetting resin material (A2) can be prepared, for example, by the same method as the first thermosetting resin material (A1).

[0049] The cured product of the second thermosetting resin material (A2) can be produced by thermally curing the second thermosetting resin material (A2). The pulverized product (B) is produced by pulverizing the cured product produced at this time. The cured product is, for example, at least one selected from the group consisting of sprues, runners, culls, burrs, and molding defects that are generated when producing a molded product by thermally curing the second thermosetting resin material (A2), and molded products produced by thermally curing the second thermosetting resin material (A2).

[0050] The pulverized material (B) can be obtained by pulverizing the cured material using a pulverizer, etc. The pulverizer is, for example, selected from the group consisting of a roller mill, a jet mill, a hammer mill, etc.

[0051] After pulverizing the cured product, the particle size may be adjusted by sieving to produce the pulverized product (B). In this case, the particle size of the pulverized product (B) can be adjusted to have a desired 90% particle size, or further to have a desired 50% particle size.

[0052] The mixing step included in the method for producing the thermosetting resin composition will now be described in detail.

[0053] In this embodiment, the mixing step involves mixing the first thermosetting resin material (A1) and the pulverized material (B).

[0054] In the thermosetting resin composition of the present disclosure, it is preferable to mix the first thermosetting resin material (A1) and the pulverized material (B) without heating in the mixing step. In this case, the appearance and impact strength of the molded product are less likely to be impaired. The reason for this is presumed to be as follows. By mixing without heating, the thermosetting reaction of the thermosetting resin (a1) is less likely to proceed in the mixing step, and the melt viscosity of the first thermosetting resin material (A1) is less likely to become excessively high. Therefore, the moldability of the thermosetting resin composition is maintained. As a result, it is considered that the appearance and impact strength of the molded product are less likely to be impaired. In particular, when the thermosetting resin (a1) is partially crosslinked in advance, the degree of crosslinking of the thermosetting resin (a1) is maintained, so that the melt viscosity of the first thermosetting resin material (A1) adjusted by the degree of crosslinking of the thermosetting resin (a1) is less likely to fluctuate, and it is considered that the moldability of the thermosetting resin composition is maintained and the pulverized material (B) is easily dispersed in the thermosetting resin composition. As a result, it is believed that the appearance and impact strength of the molded article are particularly unlikely to be impaired.

[0055] For example, the thermosetting resin composition is produced by mixing the first thermosetting resin material (A1) and the pulverized material (B) using a mixer or a mixer without heating.

[0056] When the first thermosetting resin material (A1) is pulverized and in granular form, the first thermosetting resin material (A1) and the pulverized material (B) can be mixed without heating to obtain a granular thermosetting resin composition containing the granular first thermosetting resin material (A1) and the pulverized material (B).

[0057] A method for producing a molded article by thermally curing a thermosetting resin composition will now be described in detail.

[0058] The molded article of the present disclosure is produced by thermally curing the thermosetting resin composition of the present disclosure. That is, the molded article of the present disclosure is produced by thermally curing a thermosetting resin composition that contains a first thermosetting resin material (A1) and further contains a pulverized product (B) of a cured product of a second thermosetting resin material (A2).

[0059] The molded article can be obtained, for example, by molding the thermosetting resin composition while applying heat and pressure by a known molding method such as injection molding, casting molding, or compression molding.

[0060] The molding temperature when molding the thermosetting resin composition can be appropriately set according to the type of thermosetting resin (a1) contained in the thermosetting resin composition. For example, the molding temperature is 130°C or higher and 180°C or lower. If the molding temperature is 130°C or higher and 180°C or lower, the appearance and impact strength of the molded product made from the thermosetting resin composition are less likely to be impaired. In particular, when the thermosetting resin (a1) contains at least one of a urea resin and a melamine resin, the molding temperature is preferably 130°C or higher and 180°C or lower.

[0061] The molding pressure when molding the thermosetting resin composition is preferably 5 MPa or more and 800 MPa or less.

[0062] In this embodiment, when the heated thermosetting resin composition flows during molding, the dispersibility of the pulverized material (B) in the thermosetting resin composition is easily maintained, and the pulverized material (B) is less likely to have a coarse or dense structure. As described above, when the thermosetting resin (a1) is partially crosslinked in the thermosetting resin composition, and when the first thermosetting resin material (A1) and the pulverized material (B) are mixed without heating in the mixing step, the dispersibility of the pulverized material (B) in the thermosetting resin composition is particularly easily maintained.

[0063] The thermosetting resin composition according to this embodiment is regarded as the second thermosetting resin material (A2), and the pulverized product of the cured product of the thermosetting resin composition is used as the pulverized product (B) of the cured product of the second thermosetting resin material (A2) to produce a new thermosetting resin composition. That is, the thermosetting resin composition can be recycled. For example, at least one selected from the group consisting of sprues, runners, culls, burrs, and molding defects generated when producing a molded product by thermally curing the thermosetting resin composition, and molded products produced by thermally curing the thermosetting resin composition, is regarded as the cured product of the second thermosetting resin material (A2). The pulverized product (B) obtained by pulverizing this cured product can be used to produce a new thermosetting resin composition. EXAMPLES

[0064] Specific examples of the present embodiment will be described below. Note that the present embodiment is not limited to the following examples.

[0065] Example 1 As the first thermosetting resin material (A1), a thermosetting resin composition containing a partially crosslinked urea resin (melt viscosity at 150° C.: 290 Pa·s) was used.

[0066] The pulverized material (B) of the cured product of the second thermosetting resin material (A2) was pulverized material 1 prepared as follows. A thermosetting resin composition (melt viscosity at 150°C: 290 Pa s) containing a partially crosslinked urea resin was thermally cured at 150°C to obtain a cured product. The obtained cured product was pulverized using a pulverizer and sieved to produce pulverized material 1. The pulverized material 1 obtained at this time had a 90% particle size of 190 μm and a 50% particle size of 110 μm.

[0067] The first thermosetting resin material (A1) and the pulverized product (B) of the cured product of the second thermosetting resin material (A2) were mixed without heating using a powder mixer to prepare a thermosetting resin composition. The percentage of the pulverized product 1 to the thermosetting resin composition was 5.0% by mass.

[0068] The thermosetting resin composition thus obtained was then compression molded to obtain a molded product measuring 4.2 cm in length × 7.4 cm in width × 0.2 cm in height. The compression molding conditions were a mold temperature of 150°C and a molding time of 50 seconds.

[0069] Example 2 A molded product was produced in the same manner as in Example 1, except that pulverized material 2 having a 90% particle size of 85 μm and a 50% particle size of 60 μm was used as the pulverized material (B) of the cured material of the second thermosetting resin material (A2).

[0070] Example 3 A molded article was produced in the same manner as in Example 1, except that the percentage of the pulverized material (B) of the cured product of the second thermosetting resin material (A2) relative to the thermosetting resin composition was 7.0 mass %.

[0071] Example 4 A molded article was produced in the same manner as in Example 1, except that the percentage of the pulverized material (B) of the cured product of the second thermosetting resin material (A2) relative to the thermosetting resin composition was 10.0 mass %.

[0072] Example 5 A molded product was produced in the same manner as in Example 1, except that pulverized material (B) of the cured product of the second thermosetting resin material (A2) was used as pulverized material 2 having a 90% particle size of 85 μm and a 50% particle size of 60 μm, and the percentage of pulverized material (B) of the cured product of the second thermosetting resin material (A2) to the thermosetting resin composition was 10.0 mass %.

[0073] Example 6 As the first thermosetting resin material (A1), a thermosetting resin composition (melt viscosity at 150° C.: 1288 Pa·s) containing a partially crosslinked melamine resin was used.

[0074] The pulverized material (B) of the cured product of the second thermosetting resin material (A2) was pulverized material 1 prepared as follows. A thermosetting resin composition (melt viscosity at 150°C: 290 Pa s) containing a partially crosslinked urea resin was thermally cured at 150°C to obtain a cured product. The obtained cured product was pulverized using a pulverizer and sieved to produce pulverized material 1. The pulverized material 1 obtained at this time had a 90% particle size of 190 μm and a 50% particle size of 110 μm.

[0075] The first thermosetting resin material (A1) and the pulverized product (B) of the cured product of the second thermosetting resin material (A2) were mixed without heating using a powder mixer to prepare a thermosetting resin composition. The percentage of the pulverized product 1 to the thermosetting resin composition was 5.0% by mass.

[0076] The thermosetting resin composition was then compression molded to obtain a molded product measuring 3.4 cm in length × 6.2 cm in width × 1.6 cm in height. The compression molding conditions were a mold temperature of 150°C and a molding time of 50 seconds.

[0077] Example 7 A molded product was produced in the same manner as in Example 6, except that pulverized material 2 having a 90% particle size of 85 μm and a 50% particle size of 60 μm was used as the pulverized material (B) of the cured material of the second thermosetting resin material (A2).

[0078] Example 8 A molded article was produced in the same manner as in Example 6, except that the percentage of the pulverized material (B) of the cured product of the second thermosetting resin material (A2) relative to the thermosetting resin composition was 10.0 mass %.

[0079] Example 9 A molded product was produced in the same manner as in Example 6, except that pulverized material (B) of the cured product of the second thermosetting resin material (A2) was used as pulverized material 2 having a 90% particle size of 85 μm and a 50% particle size of 60 μm, and the percentage of pulverized material (B) of the cured product of the second thermosetting resin material (A2) to the thermosetting resin composition was 10.0 mass %.

[0080] Example 10 A molded product was produced in the same manner as in Example 1, except that pulverized material 4 having a 90% particle size of 299 μm and a 50% particle size of 217 μm was used as the pulverized material (B) of the cured material of the second thermosetting resin material (A2).

[0081] Example 11 A molded product was produced in the same manner as in Example 1, except that pulverized material 5 having a 90% particle size of 300 μm and a 50% particle size of 220 μm was used as the pulverized material (B) of the cured material of the second thermosetting resin material (A2).

[0082] Comparative Example 1 As the first thermosetting resin material (A1), a thermosetting resin composition containing a partially crosslinked urea resin (melt viscosity at 150° C.: 290 Pa·s) was used.

[0083] The pulverized product (B) of the cured product of the second thermosetting resin material (A2) was not mixed, and the first thermosetting resin material (A1) was used as it was as the thermosetting resin composition.

[0084] The thermosetting resin composition thus obtained was then compression molded to obtain a molded product measuring 4.2 cm in length × 7.4 cm in width × 0.2 cm in height. The compression molding conditions were a mold temperature of 150°C and a molding time of 50 seconds.

[0085] Comparative Example 2 A molded product was produced in the same manner as in Example 1, except that pulverized material 3 having a 90% particle size of 420 μm and a 50% particle size of 260 μm was used as the pulverized material (B) of the cured material of the second thermosetting resin material (A2).

[0086] Comparative Example 3 A molded product was produced in the same manner as in Example 1, except that pulverized material (B) of the cured product of the second thermosetting resin material (A2) was used as pulverized material 3 having a 90% particle size of 420 μm and a 50% particle size of 260 μm, and the percentage of pulverized material (B) of the cured product of the second thermosetting resin material (A2) relative to the thermosetting resin composition was 10.0 mass %.

[0087] Comparative Example 4 A molded article was produced in the same manner as in Example 1, except that the percentage of the pulverized material (B) of the cured product of the second thermosetting resin material (A2) relative to the thermosetting resin composition was 20.0 mass %.

[0088] Comparative Example 5 As the first thermosetting resin material (A1), a thermosetting resin composition (melt viscosity at 150° C.: 1288 Pa·s) containing a partially crosslinked melamine resin was used.

[0089] The pulverized product (B) of the cured product of the second thermosetting resin material (A2) was not mixed, and the first thermosetting resin material (A1) was used as it was as the thermosetting resin composition.

[0090] The thermosetting resin composition was then compression molded to obtain a molded product measuring 3.4 cm in length × 6.2 cm in width × 1.6 cm in height. The compression molding conditions were a mold temperature of 150°C and a molding time of 50 seconds.

[0091] Comparative Example 6 A molded product was produced in the same manner as in Example 6, except that pulverized material 3 having a 90% particle size of 420 μm and a 50% particle size of 260 μm was used as the pulverized material (B) of the cured material of the second thermosetting resin material (A2).

[0092] Comparative Example 7 A molded article was produced in the same manner as in Example 6, except that the percentage of the pulverized material (B) of the cured product of the second thermosetting resin material (A2) relative to the thermosetting resin composition was 20.0 mass %.

[0093] Comparative Example 8 A molded product was produced in the same manner as in Example 1, except that pulverized material 6 having a 90% particle size of 303 μm and a 50% particle size of 224 μm was used as the pulverized material (B) of the cured material of the second thermosetting resin material (A2).

[0094] (Results of checking uneven distribution of crushed material (B)) Whether or not the pulverized material (B) was unevenly distributed in the molded product was confirmed by the following method. As the first thermosetting resin material (A1), a thermosetting resin composition containing a partially crosslinked urea resin (melt viscosity at 150° C.: 112 Pa·s) was used.

[0095] The pulverized product (B) of the cured product of the second thermosetting resin material (A2) was prepared as follows. A thermosetting resin composition (melt viscosity at 150°C: 290 Pa·s) containing a partially crosslinked urea resin was thermally cured at 150°C to obtain a cured product. The obtained cured product was pulverized using a pulverizer and sieved to produce the pulverized product (B). The pulverized product (B) obtained at this time had a 90% particle size of 190 μm and a 50% particle size of 110 μm.

[0096] The first thermosetting resin material (A1) and the pulverized product (B) of the cured product of the second thermosetting resin material (A2) were mixed without heating using a powder mixer to prepare a thermosetting resin composition. The percentage of the pulverized product (B) relative to the thermosetting resin composition was 5.0% by mass.

[0097] The thermosetting resin composition thus obtained was then compression molded to obtain a molded product measuring 6.9 cm in length × 4.2 cm in width × 1.8 cm in height. The compression molding conditions were a mold temperature of 150°C and a molding time of 50 seconds.

[0098] Photographs were taken of the top surface and side surface of the molded product produced, and image data of the photographs were obtained. The image data was binarized so that the parts that were green due to the crushed material (B) were converted to black (0) and the other parts were converted to white (1). The ratio of the black parts was calculated using the binarized image data. The ratio of the black parts was found by calculating the percentage of the area occupied by the crushed material (B) relative to the area of ​​the molded product. For the molded product produced, the ratio of the black parts on the top surface of the molded product was 60%, and the ratio of the black parts on the side surfaces of the molded product was 60%.

[0099] The results are shown in Table 1. When the difference in the area ratio of the black parts between the top surface and the side surfaces is small, it can be determined that the dispersibility is good.

[0100] (Visual inspection and impact strength test results) (1) Visual inspection The molded articles obtained in each of the Examples and Comparative Examples were visually inspected to see whether particles were visible on the surface of the molded articles. The results are shown in the following notation method. "A": No grains are visible on the surface of the molded product "B": If you look closely at the surface of the molded product, you can see the grains. "C": Grains are clearly visible on the surface of the molded product. (2) Impact strength The Charpy impact strength of the molded articles obtained in each of the Examples and Comparative Examples was measured using a digital impact tester DG-UB (manufactured by Toyo Seiki Seisakusho Co., Ltd.) The test conditions were based on JIS K7111-1.

[0101] The results are shown in Table 2. In Examples 1 to 5, 10, and 11, which contain urea resin and have a 90% particle size of the pulverized material (B) of the cured product of the second thermosetting resin material (A2) of 300 μm or less, and the percentage of the pulverized material (B) relative to the thermosetting resin composition of 10.0% by mass or less, the appearance and impact strength are not impaired compared to Comparative Examples 2 and 3, in which the 90% particle size of the pulverized material (B) in the thermosetting resin composition exceeds 300 μm, or Comparative Example 4, in which the percentage of the pulverized material (B) relative to the thermosetting resin composition exceeds 10.0% by mass, and the evaluation was similar to that of Comparative Example 1, in which the pulverized material (B) is not contained in the thermosetting resin composition.

[0102] Furthermore, in Examples 6 to 9, which contain melamine resin and in which the 90% particle size of the pulverized material (B) of the cured product of the second thermosetting resin material (A2) is 300 μm or less and the percentage of the pulverized material (B) to the thermosetting resin composition is 10.0 mass% or less, the appearance and impact strength are not impaired when compared to Comparative Example 6 in which the 90% particle size of the pulverized material (B) in the thermosetting resin composition exceeds 300 μm, or Comparative Example 7 in which the percentage of the pulverized material (B) to the thermosetting resin composition exceeds 10.0 mass%, and the thermosetting resin composition was evaluated to be similar to Comparative Example 5 in which the thermosetting resin composition does not contain pulverized material (B).

[0103] [Table 1]

[0104] [Table 2]

[0105] As is apparent from the above embodiments and examples, the thermosetting resin composition according to the first aspect of the present disclosure is a thermosetting resin composition containing a first thermosetting resin material (A1), and further containing a pulverized product (B) of a cured product of a second thermosetting resin material (A2), the 90% particle size of the pulverized product (B) being 300 μm or less, and the percentage of the pulverized product (B) relative to the thermosetting resin composition being 10.0 mass% or less.

[0106] According to the first aspect, the appearance and impact strength of a molded article produced by curing the thermosetting resin composition are less likely to be impaired.

[0107] In the thermosetting resin composition according to the second aspect of the present disclosure, in a first aspect, the 50% particle size of the pulverized material (B) is 250 μm or less.

[0108] According to the second embodiment, the ground material (B) becomes more easily dispersible in the thermosetting resin composition.

[0109] In the thermosetting resin composition according to the third aspect of the present disclosure, in the first or second aspect, the cured product of the second thermosetting resin material (A2) is at least one selected from the group consisting of sprues, runners, culls, burrs, and molding defects that are generated when the second thermosetting resin material (A2) is thermally cured to produce a molded product, and molded products produced by thermally curing the second thermosetting resin material (A2).

[0110] According to the third aspect, waste materials can be reused.

[0111] In the thermosetting resin composition according to the fourth aspect of the present disclosure, in any one of the first to third aspects, the percentage of the pulverized material (B) relative to the thermosetting resin composition is 5.0 mass % or less.

[0112] According to the fourth aspect, the appearance and impact strength of a molded article produced by curing the thermosetting resin composition are less likely to be impaired.

[0113] In the thermosetting resin composition according to the fifth aspect of the present disclosure, in any one of the first to fourth aspects, the first thermosetting resin material (A1) contains a thermosetting resin (a1), the second thermosetting resin material (A2) contains a thermosetting resin (a2), and each of the thermosetting resin (a1) and the thermosetting resin (a2) contains at least one resin selected from the group consisting of a urea resin, a melamine resin, a phenol resin, a melamine phenol resin, an unsaturated polyester resin, a urethane resin, and an epoxy resin.

[0114] According to the fifth aspect, the appearance and impact strength of a molded article produced by curing the thermosetting resin composition are less likely to be impaired.

[0115] In the thermosetting resin composition according to the sixth aspect of the present disclosure, in any one of the first to fifth aspects, the first thermosetting resin material (A1) contains a thermosetting resin (a1), and the thermosetting resin (a1) is partially crosslinked.

[0116] According to the sixth embodiment, the melt viscosity of the first thermosetting resin material (A1) is adjusted to a preferred value.

[0117] A method for producing a thermosetting resin composition according to a seventh aspect of the present disclosure is a method for producing a thermosetting resin composition according to any one of the first to sixth aspects, and includes a mixing step of mixing a first thermosetting resin material (A1) and a pulverized material (B).

[0118] According to the seventh aspect, the appearance and impact strength of a molded article produced by curing the thermosetting resin composition are less likely to be impaired.

[0119] In the method for producing a thermosetting resin composition according to an eighth aspect of the present disclosure, in the seventh aspect, the first thermosetting resin material (A1) and the pulverized material (B) are mixed without heating in the mixing step.

[0120] According to the eighth aspect, the melt viscosity of the first thermosetting resin material (A1) is unlikely to become excessively high.

[0121] The method for producing a thermosetting resin composition according to the ninth aspect of the present disclosure, in the seventh or eighth aspect, further includes a step of preparing a first thermosetting resin material (A1) by heating and kneading a material containing a thermosetting resin (a1).

[0122] According to the ninth embodiment, the melt viscosity of the first thermosetting resin material (A1) is adjusted to a preferred value.

[0123] A molded article according to a tenth aspect of the present disclosure contains a cured product of the thermosetting resin composition according to any one of the first to sixth aspects.

[0124] According to the tenth aspect, the appearance and impact strength of a molded article produced by curing the thermosetting resin composition are less likely to be impaired.

[0125] A method for producing a molded article according to an eleventh aspect of the present disclosure produces a molded article by thermally curing the thermosetting resin composition according to any one of the first to sixth aspects.

[0126] According to the eleventh aspect, the appearance and impact strength of a molded article produced by curing the thermosetting resin composition are less likely to be impaired.

[0127] The method for producing a molded article according to a twelfth aspect of the present disclosure is the eleventh aspect, in which the temperature when thermally curing the thermosetting resin composition is 130° C. or higher and 180° C. or lower.

[0128] According to the twelfth aspect, the appearance and impact strength of a molded article produced by curing the thermosetting resin composition are less likely to be impaired.

Claims

1. A thermosetting resin composition comprising a first thermosetting resin material (A1), Further comprising a pulverized product (B) of the cured product of the second thermosetting resin material (A2), The 90% particle size of the pulverized material (B) is 300 μm or less, The 50% particle size of the pulverized product (B) is 110 μm or more and 250 μm or less, The percentage of the pulverized material (B) relative to the thermosetting resin composition is 10.0 mass% or less; Thermosetting resin composition.

2. The cured product of the second thermosetting resin material (A2) is at least one selected from the group consisting of sprues, runners, culls, burrs and defective moldings which are generated when the second thermosetting resin material (A2) is thermally cured to produce a molded product, and molded products produced by thermally curing the second thermosetting resin material (A2). The thermosetting resin composition according to claim 1 .

3. The percentage of the pulverized material (B) relative to the thermosetting resin composition is 5.0 mass% or less, The thermosetting resin composition according to claim 1 or 2.

4. The first thermosetting resin material (A1) contains a thermosetting resin (a1), The second thermosetting resin material (A2) contains a thermosetting resin (a2), Each of the thermosetting resin (a1) and the thermosetting resin (a2) contains at least one resin selected from the group consisting of a urea resin, a melamine resin, a phenol resin, a melamine phenol resin, an unsaturated polyester resin, a urethane resin, and an epoxy resin. The thermosetting resin composition according to claim 1 .

5. The first thermosetting resin material (A1) contains a thermosetting resin (a1), and the thermosetting resin (a1) is partially crosslinked. The thermosetting resin composition according to claim 1 .

6. A method for producing a thermosetting resin composition according to any one of claims 1 to 5, comprising: The method includes a mixing step of mixing the first thermosetting resin material (A1) and the pulverized material (B); A method for producing a thermosetting resin composition.

7. In the mixing step, the first thermosetting resin material (A1) and the pulverized material (B) are mixed without heating. A method for producing the thermosetting resin composition according to claim 6.

8. The method further comprises the step of preparing the first thermosetting resin material (A1) by heating and kneading a material containing a thermosetting resin (a1), A method for producing the thermosetting resin composition according to claim 6 or 7.

9. A cured product of the thermosetting resin composition according to any one of claims 1 to 5. Molded products.

10. A molded article is produced by thermally curing the thermosetting resin composition according to any one of claims 1 to 5. Manufacturing method of molded products.

11. A method for manufacturing a molded product described in claim 10, wherein the temperature when heat-curing the thermosetting resin composition is 130°C or higher and 180°C or lower.

Images