Resin molding material and method for recycling thermosetting urethane

Abstract

This resin molding material is characterized in that (A) 5%-60% by weight of a recycled material in which thermosetting urethane, glass short fibers, and polyethylene terephthalate are mixed is mixed with (B) 40%-95% by weight of a thermoplastic resin (provided that the total amount of (A) and (B) is 100% by weight).

Description

Method for recycling resin molding materials and thermosetting urethane

[0001] The present invention relates to a method for recycling resin molding materials and thermosetting urethanes.

[0002] Patent Document 1 describes a recycling method for reusing rigid urethane foam produced from raw materials containing diphenylmethane diisocyanate as an essential component. This recycling method includes a recycling step for recycling polyurethane raw materials from the rigid urethane foam, an addition polymerization step for producing polyol by addition polymerization of alkylene oxide with the polyurethane raw material, and a foaming treatment step for adding isocyanate and other auxiliary agents to the polyol to regenerate rigid urethane foam.

[0003] Japanese Patent Application Laid-Open No. 2003-012759

[0004] Thermosetting urethane does not melt even when heated, so a chemical recycling step (chemical recycling) is required to return the thermosetting urethane to its raw urethane form, as in the recycling method of Patent Document 1.

[0005] However, chemical recycling requires huge facilities, which increases the cost of recycling and poses a barrier to practical use. Also, while urethane alone can be recycled by chemical recycling, it is difficult to recycle urethane composites.

[0006] Therefore, an object of the present invention is to recycle composite materials containing thermosetting urethane using relatively simple equipment.

[0007] In order to achieve the above object, a first aspect of the present invention is a resin molding material characterized by mixing 5 to 60% by weight of (A) recycled material, which is a mixture of thermosetting urethane, short glass fibers, and polyethylene terephthalate, with 40 to 95% by weight of (B) thermoplastic resin (however, the total amount of (A) and (B) is 100% by weight).

[0008] A second aspect of the present invention is a resin molding material characterized by mixing 5 to 60% by weight of (A) recycled material, which is a mixture of thermosetting urethane, short glass fibers, and polyethylene terephthalate, and 0 to 30% by weight (excluding 0% by weight) of (C) additives with 10 to 95% by weight of (B) thermoplastic resin (wherein the total amount of (A), (B), and (C) is 100% by weight).

[0009] A third aspect of the present invention is a method for recycling thermosetting urethane, comprising: a recycled material production step of producing a recycled material containing a mixture of thermosetting urethane, short glass fibers, and polyethylene terephthalate by pulverizing and granulating a composite material containing thermosetting urethane, glass fibers, and polyethylene terephthalate; and a resin molding material production step of producing a resin molding material by mixing the recycled material with a thermoplastic resin.

[0010] The resin molding materials of the first and second aspects, and the resin molding material produced in the resin molding material production step of the third aspect, may contain 1.5 to 29 wt% thermosetting urethane, 1.15 to 24.6 wt% short glass fiber, and 1.0 to 13.8 wt% polyethylene terephthalate.

[0011] According to the present invention, composite materials containing thermosetting urethane can be recycled using relatively simple equipment.

[0012] 1 is a diagram illustrating a recycled material production process according to a first embodiment of the present invention; FIG. 2 is a diagram illustrating a resin molding material production process according to a first embodiment of the present invention; FIG. 3 is a diagram schematically illustrating an example of the configuration of a composite material; FIG. 4 is a diagram illustrating an example of using a resin molding material in injection molding; FIG. 5 is a diagram illustrating an example of the relationship between the blending rate of recycled material and the density of a resin molded product; FIG. 6 is a diagram illustrating an example of the relationship between the blending rate of recycled material and the deflection temperature under load of a resin molded product; FIG. 7 is a diagram illustrating an example of the relationship between the blending rate of recycled material and the flexural modulus of elasticity of a resin molded product; FIG. 8 is a diagram illustrating an example of the relationship between the blending rate of recycled material and the flexural strength of a resin molded product; FIG. 9 is a diagram illustrating an example of the relationship between the blending rate of recycled material and the tensile elongation at break of a resin molded product; FIG. 10 is a diagram illustrating an example of the relationship between the blending rate of recycled material and the tensile yield strength of a resin molded product; FIG. 11 is a diagram illustrating an example of the relationship between the blending rate of recycled material and the Izod impact value (23°C) of a resin molded product; and FIG. 12 is a diagram illustrating an example of the relationship between the blending rate of recycled material and the Izod impact value (-30°C) of a resin molded product.

[0013] First Embodiment A first embodiment of the present invention will be described below with reference to the drawings. The recycling method of this embodiment includes a recycled material production step (see FIG. 1) and a resin molding material production step (see FIG. 2).

[0014] The composite material 1 to be recycled contains thermosetting urethane, glass fiber, and PET (polyethylene terephthalate). In this embodiment, a case where urethane ceiling scraps (ceiling scraps) that form the ceiling interior of an automobile will be described, but the object to be recycled is not limited to automobile ceiling scraps, and any composite material 1 containing thermosetting urethane, glass fiber, and PET will do.

[0015] The composite material 1 of this embodiment is a member in which multiple layers (six layers in the illustrated example) are stacked one on top of the other and bonded together as an integrated unit, as shown in Fig. 3. The multiple layers include a urethane layer 11, upper and lower glass mat layers 12 that overlap the upper and lower surfaces of the urethane layer 11, a film layer 13 that overlaps the upper surface of the upper glass mat layer 12, an upper surface layer 14 that overlaps the upper surface of the film layer 13, and a lower surface layer 14 that overlaps the lower surface of the lower glass mat layer 12.

[0016] The urethane layer 11 is composed of semi-rigid urethane foam (thermosetting urethane). The glass mat layer 12 is composed of glass fiber (long glass fiber) and isocyanate. The film layer 13 is composed of CPP (non-oriented polypropylene) film and PP (polypropylene) film. The surface layer 14 is composed of a nonwoven fabric or cloth made of PET fiber. That is, among the components of the composite material 1, the thermosetting urethane is contained in the urethane layer 11, the glass fiber is contained in the glass mat layer 12, and the PET is contained in the surface layer 14 as PET fiber.

[0017] The content of each component in the composite material 1 is, for example, 30 to 49% by weight of thermosetting urethane, 23 to 41% by weight of glass fiber, 20 to 23% by weight of PET, and 6 to 11% by weight of other components (however, the total amount of thermosetting urethane, glass fiber, PET, and other components is 100% by weight). The other components include the CPP film and PP film of the film layer 13, as well as adhesives that bond the layers together.

[0018] As shown in FIG. 1, the recycled material production process includes a crushing process and a recycled material pellet production process.

[0019] In the pulverization process, a composite material 1 containing thermosetting urethane, glass fiber, and PET is pulverized and granulated to produce a recycled material 3 containing a mixture of thermosetting urethane, short glass fiber, and PET. In this embodiment, the composite material 1 is fed into a pulverizer 20, pulverized to particles of approximately 5 mm in diameter, and then mixed to produce the recycled material 3. The recycled material 3 is a collection of particles 2 (composite particles) of the composite material 1 pulverized into granules. Each composite particle 2 contains at least one of the components of the composite material 1, and the recycled material 3 as a whole contains all of the components of the composite material 1. The long glass fibers of the composite material 1 are cut into short fibers (short glass fibers) of approximately 1 mm to 6 mm by pulverization and contained in the composite particles 2.

[0020] In the recycled material pellet production step, the recycled material 3 is processed into recycled material pellets 4. In this embodiment, the recycled material 3 is fed into a disk die granulator 30 and compressed into pellets to produce the recycled material pellets 4.

[0021] By thoroughly mixing the granular recycled material 3 (composite particles 2) and processing it into recycled pellets 4, the content ratio of each component in the single recycled pellet 4 can be made closer to the content ratio of each component in the composite 1. Furthermore, because the granular recycled material 3 is processed into recycled pellets 4, the recycled material 3 can be easily stored and supplied to the next process (resin molding material production process).

[0022] As shown in FIG. 2, the resin molding material producing process includes a mixing process and a molding material pellet producing process.

[0023] In the mixing step, recycled material 3 (see FIG. 1 ) is mixed with thermoplastic resin to produce a resin molding material 6. In this embodiment, recycled material pellets 4 produced in the recycled material pellet production step are mixed with base resin pellets 5 at a predetermined blending ratio to produce the resin molding material 6. The base resin pellets 5 are base resins made of thermoplastic resins that have been processed into pellets. The resin molding material 6 is a mixture of solid recycled material 3 and solid base resin at a predetermined blending ratio, and the resin molding material 6 in this embodiment is an aggregate of two types of pellets obtained by mixing recycled material pellets 4 and base resin pellets 5 at a predetermined blending ratio.

[0024] The blending ratio of the recycled material 3 (recycled material pellets 4) and the base resin (base resin pellets 5) is set to 5 to 60% by weight of the recycled material 3 and 40 to 95% by weight of the base resin (however, the total amount of the recycled material 3 and the base resin is 100% by weight).

[0025] In this embodiment, a case where PP (polypropylene) is used as the base resin will be described, but other thermoplastic resins (such as ABS resin (acrylonitrile butadiene styrene resin)) may also be used. The shape of the base resin is not limited to pellets and may be other shapes. Furthermore, the base resin may be virgin material or recycled material.

[0026] In the molding material pellet production step, the resin molding material 6 is processed into molding material pellets 7. In this embodiment, the resin molding material 6 is fed into a hopper 41 of a kneader (twin-screw extruder) 40, and the recycled material 3 (recycled material pellets 4) and base resin (base resin pellets 5) are mixed and compressed into pellets to produce molding material pellets 7. Because the resin molding material 6 is processed into molding material pellets 7, the blending ratio of the recycled material 3 and the base resin can be stabilized.

[0027] The respective contents of the base resin (PP), thermosetting urethane, short glass fibers, PET, and other components in the resin molding material 6 (molding material pellets 7) are preferably 10 to 95% by weight of the base resin, 1.5 to 29% by weight of the thermosetting urethane, 1.15 to 24.6% by weight of the short glass fibers, 1.0 to 13.8% by weight of PET, and 0.3 to 6.6% by weight of the other components (however, the total amount of the base resin, thermosetting urethane, short glass fibers, PET, and other components is 100% by weight).

[0028] The molding material pellets 7 produced in the resin molding material production step can be used to manufacture a resin molded product 60 by injection molding, extrusion molding, press molding, etc. For example, in the case of injection molding, as shown in Figure 4, the molding material pellets 7 are placed in a hopper 51 of an injection molding machine 50, heated to melt, and injected into a mold 52, and the resulting resin molded product 60 obtained by cooling and solidifying is removed from the mold 52.

[0029] Next, the relationship between the physical properties of a resin molded product 60 manufactured using the resin molding material 6 (molding material pellets 7) of this embodiment and the blending ratio (wt%) of recycled material 3 in the resin molding material 6 will be described with reference to FIGS. 5 to 12. FIGS. 5 to 12 show an example of the results of producing 10 types of resin molding materials 6 using PP as the base resin and increasing the blending ratio of recycled material 3 in increments of 5 wt% from 0 wt% to 30 wt% and increments of 10 wt% from 30 wt% to 60 wt%, and then manufacturing 10 types of resin molded products 60 by injection molding using each resin molding material 6. In each figure, the horizontal axis represents the blending ratio of recycled material 3, and the vertical axis represents physical property values.

[0030] Density of the resin molded product 60 (g / cm ３) increases as the blending ratio of recycled material 3 increases, as shown in FIG. 5. The deflection temperature under load (°C) of the resin molded product 60 at a load of 0.45 MPa increases as the blending ratio of recycled material 3 increases, as shown in FIG. 6. The flexural modulus (MPa) of the resin molded product 60 increases as the blending ratio of recycled material 3 increases, as shown in FIG. 7. The flexural strength (MPa) of the resin molded product 60 decreases as the blending ratio of recycled material 3 increases, as shown in FIG. 8. The tensile breaking elongation (%) of the resin molded product 60 decreases as the blending ratio of recycled material 3 increases, as shown in FIG. 9. The tensile yield strength (MPa) of the resin molded product 60 decreases as the blending ratio of recycled material 3 increases, as shown in FIG. 10. The Izod impact values ​​(kJ / m) of the resin molded product 60 at 23°C and -30°C ２ ) are both reduced by blending recycled material 3, as shown in FIGS.

[0031] The blending ratio of the recycled material 3 (the content of thermosetting urethane, short glass fiber, and PET in the resin molding material 6) is determined taking into consideration the required performance of the resin molded product 60 and the above-mentioned characteristics. For example, since the density and flexural modulus of the resin molded product 60 both increase as the blending ratio of the recycled material 3 increases (see FIGS. 5 and 7), if a predetermined rigidity (flexural modulus) and weight reduction are required for the resin molded product 60, the recycled material 3 should be blended at the minimum blending ratio that achieves the required flexural modulus.

[0032] According to this embodiment, a composite material 1 containing thermosetting urethane is crushed to produce recycled material 3, and the recycled material 3 is mixed with a solid base resin to produce a resin molding material 6. Therefore, the composite material 1 containing heat exchanger-curing urethane can be recycled using relatively simple equipment, without requiring large-scale equipment such as that used in chemical recycling, and without separating the thermosetting urethane from the composite material 1.

[0033] Since the glass fiber of the composite material 1 is mixed into the resin molding material 6, the rigidity of the resin molded product 60 using the resin molding material 6 is improved. In other words, the strength of the resin molded product 60 can be improved by the glass fiber of the composite material 1.

[0034] The recycled material 3 also functions as a bulking agent for the resin molding material 6, so the amount of base resin to be blended can be reduced by the amount of recycled material 3 blended, thereby reducing the amount of base resin used.

[0035] Since the composite material 1, which is a waste material, can be recycled without being incinerated, CO ２ The occurrence of this can be significantly reduced.

[0036] Furthermore, if waste resin molded articles 60 are generated, the waste resin molded articles 60 can be crushed into granules and mixed with the resin molding material 6 for recycling. In this case, although the rigidity of the resin molded articles 60 is somewhat reduced by recycling the resin molded articles 60, the rigidity is not significantly reduced, unlike when the glass fibers contained in the resin molding material 6 are long fibers, because the glass fibers contained in the resin molding material 6 and the crushed resin molded articles 60 are both short fibers of about 1 to 6 mm. In other words, even when the resin molded articles 60 are recycled, the reduction in rigidity can be suppressed compared to when only the resin molding material 6 is used.

[0037] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 13. This embodiment differs from the first embodiment in the mixing step (see Figs. 2 and 13) of the resin molding material producing step, but the other steps are common, so detailed descriptions of the steps other than the mixing step will be omitted.

[0038] 13 , in the mixing step of this embodiment, recycled material pellets 4 and additives 8 are mixed with base resin pellets 5 at a predetermined blending ratio to produce a resin molding material 9. In the molding material pellet production step, the resin molding material 9 is fed into a hopper 41 of a kneader 40, and the recycled material 3 (recycled material pellets 4), additives 8, and base resin (base resin pellets 5) are kneaded and pressed into pellets to produce molding material pellets 10.

[0039] The blending ratio of the recycled material 3 (recycled material pellets 4), additive 8, and base resin (base resin pellets 5) is set to 5 to 60% by weight of recycled material 3, 0 to 30% by weight (excluding 0% by weight) of additive 8, and 10 to 95% by weight of base resin (however, the total amount of recycled material 3, additive 8, and base resin is 100% by weight).

[0040] The additive 8 is added to adjust the physical properties of the resin molded product 60. As the additive 8, an inorganic filler such as talc or a rubber component can be used. By adding talc as the additive 8, the rigidity of the resin molded product 60 can be improved. Furthermore, by adding a rubber component as the additive 8, the Izod impact value of the resin molded product 60 can be increased, and a decrease in the Izod impact value due to the blending of the recycled material 3 can be suppressed.

[0041] Although the present invention has been described above based on the above embodiment, the present invention is not limited to the content of the above embodiment, and can be modified as appropriate without departing from the scope of the present invention. In other words, all other embodiments, examples, operational techniques, etc. made by those skilled in the art based on this embodiment are naturally included in the scope of the present invention.

[0042] For example, in the first and second embodiments, the molding material pellet production step (see FIGS. 2 and 13) may be omitted. In this case, molding material pellets 7, 10 are not produced, and the resin molding material 6, 9 produced in the mixing step may be used to produce the resin molded product 60. For example, in the case of injection molding (see FIG. 4), the resin molding material 6, 9 is directly charged into a hopper 51 in an injection molding machine 50, heated and melted, and injected into a mold 52. The resin molded product 60 obtained by cooling and solidifying is then removed from the mold 52.

[0043] In the first and second embodiments, the recycled material pellet production step (see FIG. 1) may be omitted. In this case, in the mixing step (see FIGS. 2 and 13) of the resin molding material production step, the granular recycled material 3 produced in the crushing step and the solid base resin may be mixed at a predetermined blending ratio, or the granular recycled material 3, the additive 8, and the solid base resin may be mixed at a predetermined blending ratio to produce the resin molding materials 6 and 9.

[0044] Furthermore, in the second embodiment, recycled material pellets 4 and additives 8 are mixed with base resin pellets 5 to produce resin molding material 9, but instead, as in the first embodiment, recycled material pellets 4 and base resin pellets 5 may be kneaded and pressed together to produce pellet material (corresponding to molding material pellets 7 in the first embodiment), and additives 8 may be mixed with the produced pellet material to produce resin molding material.

[0045] The present invention is useful for recycling composites containing thermoset urethanes.

[0046] DESCRIPTION OF SYMBOLS 1: Composite material 2: Composite particles 3: Recycled material 4: Recycled material pellets 5: Base resin pellets 6, 9: Resin molding material 7, 10: Molding material pellets 8: Additive 11: Urethane layer 12: Glass mat layer 13: Film layer 20: Crusher 30: Disk die granulator 40: Kneader 41: Hopper 50: Injection molding machine 51: Hopper 52: Mold 60: Resin molded product

Claims

1. A resin molding material characterized in that 5 to 60% by weight of (A) recycled material, which is a mixture of thermosetting urethane, short glass fibers, and polyethylene terephthalate, is mixed with 40 to 95% by weight of (B) thermoplastic resin (the total amount of (A) and (B) is 100% by weight).

2. A resin molding material comprising (A) 5-60% by weight of recycled material, which is a mixture of thermosetting urethane, short glass fibers, and polyethylene terephthalate, (C) 0-30% by weight (excluding 0% by weight) of additives, and (B) 10-95% by weight of thermoplastic resin (wherein the total amount of (A), (B), and (C) is 100% by weight).

3. A method for recycling thermosetting urethane, comprising: a recycled material production step of producing a recycled material containing thermosetting urethane, short glass fibers, and polyethylene terephthalate by pulverizing and granulating a composite material containing thermosetting urethane, glass fibers, and polyethylene terephthalate; and a resin molding material production step of producing a resin molding material by mixing the recycled material with a thermoplastic resin.

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