Glass fiber-reinforced recycled thermoplastic resin composition, molded article, and method for producing glass fiber-reinforced recycled thermoplastic resin composition

Abstract

To obtain a glass fiber-reinforced regenerated thermoplastic resin composition which develops excellent mechanical characteristics by apparently regenerating the breakage of glass fibers when the glass fiber-reinforced thermoplastic resin composition is recycled and has excellent moldability.SOLUTION: A glass fiber-reinforced recycled thermoplastic resin composition containing 40 to 90% by mass of a thermoplastic resin and 10 to 60% by mass of a glass fiber, in which the thermoplastic resin contains a thermoplastic resin derived from at least any one selected from a process offcut of a glass fiber-reinforced thermoplastic resin composition obtained by blending a thermoplastic resin and a glass fiber, and a recovered molded article recovered after using a molded article made of the glass fiber-reinforced thermoplastic resin composition as a product, and the glass fiber contains a glass fiber Bl having a magnesium element content of less than 3% by mass and a glass fiber Bh having a magnesium element content of 3% by mass or more and 15% by mass or less, A mass ratio Bl / Bh of the glass fiber Bl to the glass fiber Bh contained in the glass fiber-reinforced recycled thermoplastic resin composition is 0.1 or more and 10.0 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to the recycling of waste plastics, and to a glass fiber-reinforced recycled thermoplastic resin composition that exhibits extremely little deterioration in mechanical properties and excellent moldability compared to non-recycled glass fiber-reinforced thermoplastic resin compositions. [Background technology]

[0002] In recent years, there has been an increasing demand for recycling thermoplastic resins in order to realize a circular economy.

[0003] Thermoplastic resins are blended with glass fibers to form glass fiber reinforced resin compositions. However, because the glass fibers in glass fiber reinforced resin compositions are damaged during the molding and recycling processes, recycled resin compositions (hereafter referred to as recycled materials) have the problem of having lower mechanical properties than non-recycled resin compositions (hereafter referred to as virgin materials). Therefore, it has been common practice to recycle virgin materials by mixing about 10 to 30% recycled materials with them.

[0004] In response to these problems, a method for improving the strength of recycled glass fiber reinforced resin compositions has been proposed in which crushed process offcuts are not pelletized but are instead melt-kneaded into a mixture containing raw resin and resin additives, resulting in a recycled resin composition (see, for example, Patent Document 1). Also proposed is a manufacturing method in which glass fiber reinforced resin composition pellets having a specific average diameter are mixed and injection-molded (see, for example, Patent Document 2). Furthermore, a method for improving the strength of recycled resin compositions has been proposed in which a thermoplastic resin or a long fiber reinforced thermoplastic resin composition having a specific weight-average molecular weight is mixed (see, for example, Patent Document 3).

[0005] Furthermore, a method of using glass fibers having a specific element composition has been proposed as a method of improving the moist heat resistance, acid resistance, alkali resistance, and mechanical properties of glass fiber reinforced resin compositions (see, for example, Patent Document 4). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-26719 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-291986 [Patent Document 3] International Publication No. 2023 / 2903 [Patent Document 4] International Publication No. 2022 / 44482 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the manufacturing method described in Patent Document 1 is a technique for reducing the thermal history of recovered molded products, and while it can prevent further breakage of the glass fibers in the recycled resin composition, it cannot be said to be a technology for recycling glass fibers that have already been broken and have reduced mechanical properties. Furthermore, the manufacturing method described in Patent Document 2 cannot be said to be a technology for recycling glass fibers that have been broken and have reduced mechanical properties, and it was difficult to further increase the recycled material ratio to 30% or more. Furthermore, Patent Document 3 does not disclose the property recovery effect of glass fibers having a specific element composition. Patent Document 4 does not have a technical idea for improving the mechanical properties of recycled materials, and there is also the issue of reduced fluidity of the resin composition due to the glass fibers having a specific element composition.

[0008] The present invention aims to obtain a glass fiber-reinforced recycled thermoplastic resin composition that exhibits excellent mechanical properties by apparently recovering broken glass fibers during recycling of the glass fiber-reinforced thermoplastic resin composition, and that has both mechanical properties and moldability. [Means for solving the problem]

[0009] Therefore, the inventors conducted extensive research to solve the above problems, and discovered that the above problems can be solved by mixing glass fibers having a specific element composition with recycled materials containing a thermoplastic resin and glass fibers, thereby arriving at the present invention.

[0010] That is, the present invention has the following configuration. 1. A glass fiber reinforced recycled thermoplastic resin composition containing (A) 40 to 90% by mass of a thermoplastic resin and (B) 10 to 60% by mass of glass fiber, wherein the (A) thermoplastic resin contains a thermoplastic resin derived from at least one selected from process waste materials of a glass fiber reinforced thermoplastic resin composition obtained by blending a thermoplastic resin and glass fiber, and recovered molded products recovered after a molded product made of the glass fiber reinforced thermoplastic resin composition has been used as a product, and the (B) glass fiber contains glass fiber Bl having a magnesium element content of less than 3% by mass (hereinafter sometimes referred to as glass fiber Bl) and glass fiber Bh having a magnesium element content of 3% to 15% by mass (hereinafter sometimes referred to as high modulus glass fiber Bh), and the mass ratio Bl / Bh of the glass fiber Bl to the high modulus glass fiber Bh contained in the glass fiber reinforced recycled thermoplastic resin composition is 0.1 to 10.0, 2. (B) The glass fiber reinforced recycled thermoplastic resin composition according to item 1, wherein the ratio (Lw / Ln) of the weight average fiber length (Lw) to the number average fiber length (Ln) of the glass fibers is 1.30 or more and 3.00 or less. 3. The glass fiber reinforced recycled thermoplastic resin composition according to item 1 or 2, wherein (A) the thermoplastic resin comprises at least one selected from the group consisting of polyphenylene sulfide, polyamide, polybutylene terephthalate, and liquid crystal polyester; 4. A molded article made of the glass fiber reinforced recycled thermoplastic resin composition according to any one of items 1 to 3. 5. The molded product according to item 4, having a thickness of 2 mm or more and 15 mm or less. 6. A method for producing a glass fiber reinforced recycled thermoplastic resin composition, comprising crushing at least one selected from process waste of a glass fiber reinforced thermoplastic resin composition obtained by blending a thermoplastic resin and glass fibers, and recovered molded articles recovered after the use of a molded article made of the glass fiber reinforced thermoplastic resin composition as a product, to obtain (X) crushed molded article, and mixing (X) crushed molded article, (Y) a thermoplastic resin substantially the same as the thermoplastic resin constituting the (X) crushed molded article (hereinafter, sometimes referred to as (Y) substantially the same thermoplastic resin), and (Z) glass fiber Bh having a magnesium element content of 3% by mass or more and 15% by mass or less (hereinafter, sometimes referred to as high-elasticity glass fiber Bh); 7. A method for producing a glass fiber reinforced recycled thermoplastic resin composition according to item 6, comprising mixing (Y) substantially the same thermoplastic resin and (Z) high-modulus glass fiber Bh to obtain a (YZ) glass fiber reinforced thermoplastic resin composition, and then mixing the (YZ) glass fiber reinforced thermoplastic resin composition with (X) crushed molded articles; 8. (YZ) The method for producing a glass fiber-reinforced recycled thermoplastic resin composition according to item 7, wherein the glass fiber-reinforced thermoplastic resin composition is a long glass fiber-reinforced thermoplastic resin composition. 9. A method for producing a fiber-reinforced recycled thermoplastic resin composition according to any one of items 6 to 8, wherein the thermoplastic resin comprises at least one selected from the group consisting of polyphenylene sulfide, polyamide, polybutylene terephthalate, and liquid crystal polyester. [Effects of the Invention]

[0011] The glass fiber-reinforced recycled thermoplastic resin composition obtained by the method of the present invention retains the same mechanical strength and moldability as virgin materials, even after recycling, and can be used in a wide range of fields such as injection molding. A glass fiber-reinforced recycled thermoplastic resin composition with these properties will be a material that contributes to the realization of a circular economy. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will now be described in further detail.

[0013] The method for producing a glass fiber-reinforced recycled thermoplastic resin composition of the present invention is characterized by crushing at least one selected from process offcuts of a glass fiber-reinforced thermoplastic resin composition formed by blending a thermoplastic resin and glass fibers, and recovered molded products recovered after a molded product made of the glass fiber-reinforced thermoplastic resin composition has been used as a product, to obtain (X) crushed molded product, and mixing the (X) crushed molded product with (Y) a thermoplastic resin substantially the same as the thermoplastic resin constituting the (X) crushed molded product (hereinafter sometimes referred to as (Y) substantially the same thermoplastic resin), and (Z) glass fiber Bh having a magnesium element content of 3% by mass or more and 15% by mass or less (hereinafter sometimes referred to as high-modulus glass fiber Bh).

[0014] In the present invention, "mixing" refers to melt-kneading each component using an extruder or the like. Typical examples of melt-kneading include feeding raw materials into a commonly known melt-kneading machine, such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll, and melt-kneading the raw materials. However, to prevent breakage of the glass fiber and thermal degradation of the thermoplastic resin, it is preferable to use a single-screw extruder or a twin-screw extruder with a screw configuration that can prevent breakage of the glass fiber. This method produces a glass fiber-reinforced recycled thermoplastic resin composition with minimal variation in properties. Another method is to pellet-mix the components (hereinafter sometimes referred to as "dry blending") without melt-kneading. This method can prevent breakage of the glass fiber in the crushed (X) molded product, and produce a glass fiber-reinforced recycled thermoplastic resin composition with excellent properties.

[0015] The process waste materials used for (X) crushed molded products are, for example, process waste materials generated in at least one process selected from the process for producing a glass fiber-reinforced thermoplastic resin composition containing a thermoplastic resin and glass fibers, and the process for molding a molded product from the glass fiber-reinforced thermoplastic resin composition. Examples of such process waste materials include crushed molded products molded by injection molding or the like from glass fiber-reinforced thermoplastic resins, and crushed sprues, runners, and other materials recovered during injection molding. The glass fiber-reinforced thermoplastic resin may contain two or more types of glass fiber-reinforced thermoplastic resins. Furthermore, (X) crushed molded product materials include crushed recycled molded products that have been collected after commercial use as molded products made from glass fiber-reinforced thermoplastic resin compositions. From the viewpoint of realizing a circular economy, (X) crushed molded products are preferably crushed molded products made from a glass fiber reinforced thermoplastic resin composition that have been recovered after being used in the market as a finished product, and such molded products are more preferably made from the glass fiber reinforced recycled thermoplastic resin composition obtained by the manufacturing method of the present invention, and are particularly preferably crushed molded products that have been recycled multiple times.

[0016] (X) When the crushed molded products are crushed from recovered molded products that have been used in the market as products, it is preferable to wash the crushed molded products with water or an organic solvent either before or after crushing to remove any attached matter, in order to prevent deterioration of mechanical properties and odors due to contaminants.

[0017] (X) Crushed molded product fragments are easy to handle if they are products made only of resin material, but in the present invention, insert molded products made of resin and metal can also be used as long as the metal is removed. They may also contain small amounts of metal components. In such cases, removing the metal components during recovery reduces productivity, so it is preferable to use a metal removal device in the manufacturing process for crushed molded product fragments. Specific examples of metal removal devices include a method in which metal is attached to a magnet and removed, and magnetic or eddy current separation devices.

[0018] (X) The crushed molded product is preferably a crushed molded product pellet obtained by crushing a molded product and then melt-kneading the crushed product, from the viewpoint of improving classification during mixing and feedability to an extruder or molding machine.

[0019] (X) The crushed molded product is preferably of a size that can be fed into an extruder or molding machine, and the major axis dimension of the fragments is more preferably 1 to 10 mm or less.

[0020] The thermoplastic resins constituting the (X) crushed molded product are resins that can reversibly melt and solidify upon heating and cooling. Specific examples include vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, polyvinyl alcohol, polyvinyl acetal, polystyrene, AS resin, ABS resin, methacrylic resin, polyethylene, polypropylene, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, liquid crystal polyester resin, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, polyether sulfone, polyether imide, polyether ether ketone, fluororesin, thermoplastic elastomer, and copolymers thereof, as well as polymer alloys composed of multiple resins. Crystalline resins are preferred to enhance fluidity during processing and prevent breakage of glass fibers. More preferably, the resins include at least one selected from the group consisting of polyphenylene sulfide, polyamide, polybutylene terephthalate, and liquid crystal polyester, which are engineering plastics that are resistant to degradation during the thermal history associated with recycling.

[0021] The glass fibers constituting the (X) crushed molded product are selected from known glass fibers, and in many cases, E-glass, which is widely available on the market, is selected. E-glass corresponds to glass fiber Bl, which has a magnesium content of less than 3% by mass. It is also acceptable for the glass fibers constituting the (X) crushed molded product to contain high-elasticity glass fiber Bh.

[0022] Also preferred are glass fibers whose surfaces have been pre-treated with a coupling agent such as an epoxy compound, an isocyanate compound, an organic silane compound, an organic titanate compound, or an organic borane compound to improve the bundling ability of the glass fibers and the dispersibility of the glass fibers when blended with a resin. Such glass fibers have improved interfacial adhesion and dispersibility with thermoplastic resins, and can achieve a high strength improvement effect, heat resistance, and chemical resistance.

[0023] Furthermore, the glass fiber diameter is preferably 1 to 50 μm, more preferably 3 to 30 μm, and particularly preferably 5 to 20 μm. The smaller the glass fiber diameter, the more improved the tensile strength and flexural strength can be obtained, and the larger the fiber diameter, the less likely the fiber is to break during molding processing, and the more improved the mechanical properties can be obtained.

[0024] The glass fiber may also be a glass fiber having a flat cross section, and in the cross section obtained by cutting the glass fiber perpendicular to the length direction, the ratio of the major axis (the longest linear distance in the cross section) to the minor axis (the longest linear distance perpendicular to the major axis) (hereinafter sometimes referred to as the flattening ratio) is preferably 2.0 or more, more preferably 2.5 or more, and particularly preferably 3.0 or more. The upper limit of the flattening ratio is preferably 8.0 or less, more preferably 6.0 or less, and particularly preferably 4.5 or less. The major axis of the cross section is preferably 10 μm or more, more preferably 20 μm or more. The upper limit of the major axis is preferably 80 μm or less, more preferably 45 μm or less. The minor axis of the cross section is preferably 2 μm or more, more preferably 5 μm or more. The upper limit of the minor axis is preferably 20 μm or less, and more preferably 15 μm or less.

[0025] In the present invention, "(Y) substantially the same thermoplastic resin" refers to a thermoplastic resin having the same repeating unit as the thermoplastic resin constituting the crushed molded article (X), and it is effective to identify it by known spectroscopic analysis, elemental analysis, or thermal analysis. Furthermore, a combination of compatible thermoplastic resins is also substantially the same thermoplastic resin. "Compatible" refers to the behavior of forming a single phase when different thermoplastic resins are polymer-blended, and it is effective to identify it by known phase structure observation, etc. Furthermore, when the thermoplastic resin constituting the crushed molded article (X) is a polymer alloy, it is preferable that "(Y) substantially the same thermoplastic resin" is also a polymer alloy composed of the same thermoplastic resin as the polymer alloy of the crushed molded article (X).

[0026] The (Z) high-modulus glass fiber Bh of the present invention, having a magnesium element content of 3% by mass or more and 15% by mass or less, is a glass fiber that exhibits excellent elastic modulus and specific elastic modulus due to its specific element composition. By mixing the high-modulus glass fiber Bh with (X) crushed molded product material in which the glass fiber has been broken during recycling, the high-modulus glass fiber Bh's resistance to breakage can be utilized to seemingly regenerate the glass fiber, thereby exhibiting excellent mechanical properties, and a glass fiber-reinforced recycled thermoplastic resin composition that exhibits both mechanical properties and moldability can be obtained.

[0027] Examples of the elemental composition of the high-modulus glass fiber Bh include those disclosed in International Publication No. 2021 / 256217. From the viewpoint of increasing the elastic modulus of the high-modulus glass fiber Bh, the magnesium element content is preferably 5% by mass or more, more preferably 7% by mass or more, and particularly preferably 9% by mass or more. The upper limit is preferably 13% by mass or less, more preferably 11% by mass or less, from the viewpoint of increasing the fluidity of the glass fiber-reinforced recycled thermoplastic resin material. Furthermore, the magnesium element content / calcium element content ratio (hereinafter sometimes referred to as Mg / Ca) in the high-modulus glass fiber Bh is preferably 0.5 or more, from the viewpoint of increasing the elastic modulus of the high-modulus glass fiber Bh. The upper limit is preferably 20% by mass or less, more preferably 15% by mass or less. Furthermore, the aluminum element content in the high-modulus glass fiber Bh also has the effect of adjusting the crystallinity of the high-modulus glass fiber Bh and increasing the elastic modulus. The lower limit is preferably 3% by mass or more, more preferably 5% by mass or more, particularly preferably 7% by mass or more, and particularly preferably 9% by mass or more. The upper limit is preferably 30% by mass or less, and more preferably 15% by mass or less.

[0028] The content of the specific element is a value obtained by observing the glass fiber using scanning electron microscope energy dispersive X-ray spectroscopy (SEM-EDX), measuring the mass fraction of the specific element in five randomly selected glass fibers, and calculating the number average.

[0029] It is preferable that the surface of the (Z) high-modulus glass fiber Bh is preliminarily treated with a coupling agent such as an epoxy compound, an isocyanate compound, an organic silane compound, an organic titanate compound, or an organic borane compound to improve the bundling ability of the glass fiber and the dispersibility when blended with a resin. Such glass fiber has improved interfacial adhesion and dispersibility with a thermoplastic resin, and can achieve a high strength improvement effect, heat resistance, and chemical resistance.

[0030] The glass fiber diameter of the (Z) high-modulus glass fiber Bh is preferably 1 to 50 μm, more preferably 3 to 30 μm, and particularly preferably 5 to 20 μm. The smaller the glass fiber diameter, the more improved the tensile strength and flexural strength can be obtained, and the larger the fiber diameter, the less likely the fiber is to break during molding, and the more improved the mechanical properties can be obtained.

[0031] The (Z) high-modulus glass fibers Bh may be in the form of chopped strands or continuous fiber bundles (rovings).

[0032] The method for producing a glass fiber-reinforced recycled thermoplastic resin composition in the present invention may involve pre-mixing (Y) substantially the same thermoplastic resin with (Z) high-modulus glass fibers Bh to obtain (YZ) a glass fiber-reinforced thermoplastic resin composition, and then mixing the (YZ) glass fiber-reinforced thermoplastic resin composition with (X) crushed molded article. Such a method is preferred because it produces a glass fiber-reinforced recycled thermoplastic resin composition with little variation in each property.

[0033] When the (YZ) glass fiber reinforced thermoplastic resin composition is produced by melt-kneading (Y) substantially the same thermoplastic resin with (Z) high-modulus glass fibers Bh, a typical example is a method in which raw materials are supplied to a commonly known melt-kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll and melt-kneaded. From the viewpoint of increasing the number-average fiber length (Ln) of the glass fibers in the (YZ) glass fiber reinforced thermoplastic resin composition and efficiently regenerating the apparent glass fiber length in the glass fiber reinforced recycled thermoplastic resin composition, it is preferable to use a single-screw extruder or a twin-screw extruder with a screw configuration that can suppress breakage of the glass fibers.

[0034] Furthermore, from the viewpoint of further increasing the Ln of the glass fibers in the (YZ) glass fiber reinforced thermoplastic resin composition and obtaining a glass fiber reinforced recycled thermoplastic resin composition that surpasses the properties of virgin material, it is more preferable that the (YZ) long glass fiber reinforced thermoplastic resin composition contains glass fiber bundles aligned in the length direction of the pellets in the thermoplastic resin, and the length of the pellets is substantially the fiber length of the glass fiber bundles.

[0035] The length of the pellets of the (YZ) long glass fiber reinforced thermoplastic resin composition, i.e., Ln of the glass fibers, is preferably 3.0 to 50 mm from the viewpoints of strength improvement effect and handleability, and is preferably 20 mm or less, more preferably 10 mm or less, from the viewpoint of mixability with the (X) crushed molded article, and particularly preferably 7.0 mm or less from the viewpoint of suppressing classification.

[0036] (YZ) Long glass fiber reinforced thermoplastic resin compositions can be obtained by a direct roving method in which continuous glass fiber bundles are directly fed into an extruder, a pultrusion method in which continuous glass fiber bundles are impregnated with resin, or a known method in which continuous reinforcing fiber bundles are coated with resin. However, from the viewpoint of obtaining (Y) long glass fiber reinforced thermoplastic resin compositions using substantially the same thermoplastic resin, it is preferable to produce them as a core-sheath structure in which the thermoplastic resin is arranged so as to cover the periphery of the reinforcing fiber bundles, as exemplified in WO 2023 / 2903, for example, so as to reduce limitations on the matrix resin.

[0037] The amount of (X) crushed molded articles mixed in the glass fiber reinforced recycled thermoplastic resin composition of the present invention is preferably 20% by mass or more, more preferably 30% by mass or more, and from the viewpoint of contributing to a circular economy, is even more preferably 40% by mass or more, particularly preferably 50% by mass or more, and especially preferably 70% by mass or more. Also, from the viewpoint of obtaining a glass fiber reinforced recycled thermoplastic resin composition with excellent properties, the amount of (X) crushed molded articles mixed is preferably 90% by mass or less.

[0038] In addition, the amount of (Y) substantially the same thermoplastic resin and (Z) high-modulus glass fiber Bh mixed with (X) crushed molded article is preferably such that the difference between the ash content of the glass fiber reinforced recycled thermoplastic resin composition and the ash content of (X) crushed molded article divided by the ash content of (X) crushed molded article is -35% or more and 35% or less, from the viewpoint of stabilizing quality. Furthermore, from the viewpoint of stabilizing the moldability of the glass fiber reinforced recycled thermoplastic resin composition, the lower limit is preferably -20% or more, more preferably -15% or more, and particularly preferably -10% or more, and the upper limit is preferably 20% or less, more preferably 15% or less, and particularly preferably 10% or less. In particular, from the viewpoint of realizing closed recycling, the lower limit is particularly preferably -5% or more, and the upper limit is particularly preferably 5% or less.

[0039] The ash content is a percentage obtained by dividing the mass of the residue obtained by firing the glass fiber reinforced recycled thermoplastic resin composition or crushed (X) molded product at 550°C for 3 hours by the mass before firing.

[0040] The glass fiber reinforced recycled thermoplastic resin composition of the present invention comprises 40 to 90 mass% of (A) thermoplastic resin and 10 to 60 mass% of (B) glass fiber. The amount of (B) glass fiber is preferably 20 mass% or more, more preferably 30 mass% or more, and even more preferably 40 mass% or more to obtain excellent strength.

[0041] The thermoplastic resin (A) in the present invention is a resin that melts and solidifies reversibly upon heating and cooling. Specific examples include vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, polyvinyl alcohol, polyvinyl acetal, polystyrene, AS resin, ABS resin, methacrylic resin, polyethylene, polypropylene, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, liquid crystal polyester resin, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, polyether sulfone, polyether imide, polyether ether ketone, fluororesin, thermoplastic elastomer, and copolymers thereof, as well as polymer alloys composed of multiple resins. Crystalline resins are preferred to reduce the melt viscosity during processing and prevent breakage of the reinforcing fibers. More preferably, the resin is at least one selected from the group consisting of polyphenylene sulfide, polyamide, polybutylene terephthalate, and liquid crystal polyester, which are engineering plastics that are resistant to degradation due to the thermal history associated with recycling.

[0042] The (A) thermoplastic resin of the present invention contains a thermoplastic resin derived from at least one selected from process waste of a glass fiber-reinforced thermoplastic resin composition containing a thermoplastic resin and glass fibers, and a recovered molded product recovered after the use of a molded product made from the glass fiber-reinforced thermoplastic resin composition. These thermoplastic resins are preferably derived from the (X) crushed molded product. The (A) thermoplastic resin of the present invention preferably contains the (Y) thermoplastic resin derived from the (Y) substantially the same thermoplastic resin.

[0043] It is preferable that the thermoplastic resin (A) of the present invention has traceability that proves its recycled origin, which may be certified by a certification body or may be traceability using a blockchain system.

[0044] The glass fiber-reinforced recycled thermoplastic resin composition of the present invention is characterized by containing (B) glass fibers, glass fibers Bl having a magnesium element content of less than 3 mass% (hereinafter sometimes referred to as glass fibers Bl), and high-modulus glass fibers Bh. Note that although the magnesium element content in glass fibers Bl is less than 3 mass%, glass fibers Bl also include those with a content of 0 mass%, i.e., those containing no magnesium element at all.

[0045] The glass fiber-reinforced recycled thermoplastic resin composition of the present invention utilizes the mechanical strength due to the fiber strength of the high-modulus glass fiber Bh and its tendency to remain long and resistant to breakage due to stress during molding, thereby restoring the properties of the glass fiber-reinforced thermoplastic resin composition when the reinforcing effect is lost due to breakage of the glass fiber during recycling. In particular, the fiber strength of the high-modulus glass fiber Bh can restore tensile properties that are difficult to recover due to the influence of glass fiber orientation. Therefore, the glass fiber-reinforced recycled thermoplastic resin composition of the present invention can exhibit properties that surpass those of virgin materials. On the other hand, because the high-modulus glass fiber Bh is resistant to breakage due to stress during molding due to its fiber strength, it has the problem of reduced fluidity. Therefore, in order to achieve both mechanical properties and moldability, the glass fiber-reinforced recycled thermoplastic resin composition of the present invention must have a mass ratio Bl / Bh of 0.1 to 10.0. The lower limit is preferably 0.3 or more, more preferably 0.5 or more. From the viewpoint of obtaining excellent fluidity, 0.7 or more is particularly preferred, and 1.0 or more is even more preferred. The upper limit is preferably 9.0 or less, more preferably 7.0 or less, from the viewpoint of improving mechanical properties, and is further preferably 5.0 or less, particularly preferably 4.0 or less, from the viewpoint of closed recycling of virgin materials for equivalent uses. (B) Glass fiber is derived from glass fiber contained in (X) crushed molded product material or (Z) high-modulus glass fiber Bh. Therefore, Bl / Bh can be adjusted by changing the type and mixing amount of (X) crushed molded product material and (Z) high-modulus glass fiber Bh when producing a glass fiber-reinforced recycled thermoplastic resin composition.

[0046] The Bl / Bh can be determined from the blending amounts of glass fiber Bl and high-modulus glass fiber Bh blended in the glass fiber-reinforced recycled thermoplastic resin composition. To calculate these blending amounts, the glass fiber-reinforced recycled thermoplastic resin composition may be baked to extract the glass fibers, which may then be observed using a scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDX), and 100 randomly selected glass fibers may be subjected to elemental analysis. Then, the blending amounts may be calculated from the number of glass fibers Bl having a magnesium element content of less than 3% by mass and high-modulus glass fibers Bh having a (Z) magnesium element content of 3% to 15% by mass.

[0047] The glass fiber reinforced recycled thermoplastic resin composition of the present invention and molded articles made from the glass fiber reinforced recycled thermoplastic resin composition contain (X) broken short glass fibers derived from crushed molded articles and (Z) long glass fibers derived from high-modulus glass fibers Bh. This results in a broad fiber length distribution, and the fiber length distribution (Lw / Ln), which is the ratio of the weight average fiber length (Lw) to the number average fiber length (Ln), is preferably 1.30 to 3.00. As a result, while maintaining the fluidity derived from short glass fibers, it is easy to express the properties derived from long glass fibers, and it is also possible to favorably change the orientation of the glass fibers. This not only improves the moldability and properties of the glass fiber reinforced recycled thermoplastic resin composition, but also makes it possible to express properties that surpass those of virgin materials.

[0048] In the present invention, Lw / Ln is preferably 1.40 or more, more preferably 1.50 or more, from the viewpoint of achieving both mechanical properties and fluidity. From the viewpoint of the quality stability of molded products, Lw / Ln is preferably 2.50 or less, more preferably 2.00 or less. Lw / Ln can be adjusted when producing a glass fiber-reinforced recycled thermoplastic resin composition by changing the types and amounts of (X) crushed molded product and (Z) high-modulus glass fiber Bh, or by mixing (YZ) long glass fiber-reinforced thermoplastic resin composition with (X) crushed molded product.

[0049] The weight-average fiber length (Lw) of the (B) glass fibers in the glass fiber-reinforced recycled thermoplastic resin composition of the present invention and in molded articles made from the glass fiber-reinforced recycled thermoplastic resin composition is preferably 50 to 5,000 μm from the viewpoint of ensuring excellent mechanical properties and fluidity. From the viewpoint of obtaining excellent mechanical properties, it is preferably 100 μm or more, more preferably 200 μm or more, and from the viewpoint of use as a metal replacement, it is even more preferably 300 μm or more. Furthermore, when Lw / Ln is within a preferred range, it is more preferably 400 μm or more, and particularly preferably 500 μm or more, since it is possible to achieve both mechanical properties and fluidity. Furthermore, from the viewpoint of obtaining excellent fluidity, it is preferably 4,000 μm or less, more preferably 3,000 μm or less, and particularly preferably 2,000 μm or less.

[0050] The glass fiber-reinforced recycled thermoplastic resin composition of the present invention has the fluidity resulting from the fiber strength of the high-modulus glass fiber Bh, and the characteristics of being less susceptible to breakage and tending to retain a long fiber length. This means that when the glass fiber-reinforced recycled thermoplastic resin composition is molded to obtain a molded product, breakage of the high-modulus glass fiber Bh is suppressed, making it possible to obtain a molded product with the above-mentioned preferred Lw and Lw / Ln.

[0051] Here, the weight-average fiber length (Lw) and number-average fiber length (Ln) of (B) glass fiber are values ​​calculated based on the following formula using the measured values ​​(μm) obtained by baking glass fiber-reinforced recycled thermoplastic resin composition pellets or a molded product of the glass fiber-reinforced recycled thermoplastic resin composition to extract the glass fibers, observing the image magnified 50 to 100 times with an optical microscope, and measuring the lengths of 1,000 randomly selected glass fibers. Number average fiber length (Ln) = Σ(Li × ni) / Σni Weight average fiber length (Lw)=Σ(Li 2 ×ni) / Σ(Li×ni) Li: Fiber length of glass fiber ni: Number of glass fibers of fiber length Li.

[0052] The glass fiber-reinforced recycled thermoplastic resin composition of the present invention exhibits excellent heat cycle resistance due to the improved physical properties of the high-modulus glass fiber Bh. Heat cycle resistance is a property determined by the number of treatment cycles until cracks are observed in an insert-molded article obtained by insert-molding a thermoplastic resin into a metal block, in which the insert-molded article is exposed to high-temperature conditions (e.g., 130°C for 1 hour) and then to low-temperature conditions (e.g., -40°C for 1 hour). This is an important characteristic value for automotive applications, which require resistance to severe temperature changes.

[0053] By adjusting the weight ratio Br / Bf, it is possible to adjust the moldability and heat cycle resistance, and it is possible to perform closed recycling for the same applications as virgin materials, or to develop properties that surpass those of virgin materials, allowing for upcycling.

[0054] The glass fiber-reinforced recycled thermoplastic resin composition of the present invention may contain non-fibrous fillers such as fullerene, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, asbestos, silicates such as alumina silicate, metal compounds such as silicon oxide, magnesium oxide, alumina, zirconium oxide, titanium oxide, and iron oxide, carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide, glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon carbide, carbon black, silica, and graphite. These inorganic fillers may be hollow, and two or more types may be used in combination. These inorganic fillers may also be pretreated with coupling agents such as isocyanate compounds, organosilane compounds, organotitanate compounds, organoborane compounds, and epoxy compounds. Among these, magnesium hydroxide, calcium carbonate, silica, and carbon black are preferred in terms of electrical properties, corrosion prevention, lubricating properties, and conductivity-imparting effects.

[0055] The glass fiber-reinforced recycled thermoplastic resin composition of the present invention can be blended with conventional additives such as phenolic antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, plasticizers such as organophosphorus compounds, nucleating agents such as organophosphorus compounds and polyether ether ketone, metal soaps such as Montan acid waxes, lithium stearate and aluminum stearate, mold release agents such as ethylenediamine-stearic acid-sebacic acid polycondensates and silicone compounds, as well as water, lubricants, UV inhibitors, colorants, and foaming agents. These additives are preferably blended in an amount of 0.01 to 5% by mass relative to the resin composition, so long as they do not impair the effects of the invention.

[0056] The glass fiber reinforced recycled thermoplastic resin composition of the present invention can be applied to various molding methods, such as extrusion molding, injection molding, blow molding, calendar molding, compression molding, vacuum molding, foam molding, blow molding, and rotational molding. In particular, it is preferably applied to injection molding because of its excellent balance of mechanical properties and fluidity.

[0057] The glass fiber-reinforced recycled thermoplastic resin composition of the present invention can be used for many purposes, but is particularly preferably used in molded articles with a thickness of 2 mm to 15 mm, in which the above-mentioned specific fiber length distribution is easily obtained, and is particularly preferably used for automotive components, where demand for a circular economy is increasing. [Example]

[0058] The effects of the present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples. Evaluations in each example and comparative example were carried out by the following methods.

[0059] (1) Ash content The resin compositions obtained in each of the Reference Examples, Examples, and Comparative Examples were weighed, placed in a crucible, and fired for 3 hours in an electric furnace set at 550°C to obtain an inorganic residue containing glass fibers. This residue was weighed, and the mass ratio of the inorganic residue containing glass fibers to the mass of the sample before firing was calculated to determine the ash content.

[0060] (2) Measurement of the flow length of resin compositions The resin compositions obtained in each of the Reference Examples, Examples, and Comparative Examples were dried in a hot air dryer at 130°C for 3 hours, and then molded using a Sumitomo Heavy Industries SE-30D injection molding machine and a 1mm thick (1mmt) spiral flow mold under the following conditions: cylinder temperature 320°C, mold temperature 140°C, injection speed 230mm / sec, injection pressure 98MPa, injection time 5sec, and cooling time 15sec, and the flow length (unit: mm) was measured. The larger this value, the better the flowability.

[0061] (3) Test piece preparation by injection molding The resin compositions obtained in each of the Reference Examples, Examples, and Comparative Examples were dried in a hot air dryer at 130°C for 3 hours, and then injection-molded into 4 mm thick ISO (1A) dumbbell test pieces using an injection molding machine SE75-DUZ manufactured by Sumitomo Heavy Industries under conditions of a cylinder temperature of 310°C, a mold temperature of 140°C, and a screw rotation speed of 100 rpm.

[0062] (4) Mechanical properties The tensile properties of the ISO (1A) dumbbell test specimens obtained in (3) above were evaluated at 23°C using an Autograph AG-Xplus 20kN testing machine in accordance with ISO 527-1, -2 (2012), with a support distance of 114 mm and a tensile speed of 5 mm / min.

[0063] Next, the bending properties were evaluated according to ISO178 (2010) at a support distance of 64 mm and a speed of 2 mm / min.

[0064] Next, the ISO (1A) dumbbell obtained in the above item (4) was cut to obtain a test piece, and the Charpy impact strength (with notch) was evaluated in accordance with ISO179 (2010).

[0065] (5) Fiber length analysis of glass fibers Samples of the resin compositions obtained in each of the Reference Examples, Examples, and Comparative Examples, and the ISO (1A) dumbbell test specimens obtained in (4) above were cut to remove 1 cm square pieces from the center, weighed as samples, placed in a crucible, and fired for 3 hours in an electric furnace set at 550°C to obtain glass fiber residue. Images of this residue magnified 50 to 100 times were observed with an optical microscope, and the lengths of 1,000 randomly selected glass fibers were measured, and the measured values ​​(μm) were used to perform calculations based on the following formula. Number average fiber length (Ln) = Σ(Li × ni) / Σni Weight average fiber length (Lw)=Σ(Li 2 ×ni) / Σ(Li×ni) Li: Fiber length of glass fiber ni: Number of glass fibers of fiber length Li.

[0066] (6) Elemental analysis of glass fibers When the blending amounts of glass fiber Bl and high-modulus glass fiber Bh were known, the mass ratio of glass fiber Bl / Bh in the resin composition obtained in each Reference Example, Example, and Comparative Example was calculated using that mass ratio. When the blending amount was unknown, the resin composition and the ISO (1A) dumbbell test specimen obtained in (4) above were cut to obtain a 1 cm square piece from the center, weighed, placed in a crucible, and fired for 3 hours in an electric furnace set at 550°C to obtain a glass fiber residue. Images of this residue were observed at 50-100x magnification using a scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDX), and 100 randomly selected glass fibers were subjected to elemental analysis. The blending amounts of glass fiber Bl and high-modulus glass fiber Bh were calculated from the number of fibers.

[0067] (7) Heat cycle resistance Using the resin compositions obtained in each Reference Example, Example, and Comparative Example, a metal insert molded product was obtained by insert molding a metal block (SUS430) using a Sumitomo Heavy Industries SE75-DUZ injection molding machine under conditions of a cylinder temperature of 320°C and a mold temperature of 140°C. The obtained metal insert molded product was subjected to thermal shock treatment, with one treatment cycle consisting of exposing it to 130°C for 1 hour and then to -40°C for 1 hour, and the presence or absence of cracks was confirmed visually every five treatment cycles. The average value (n3) of the number of thermal shock treatments at which cracks were observed was taken as the heat cycle resistance. The more treatments performed until cracks occurred, the better the heat cycle resistance (thermal shock resistance) and the more preferable it was.

[0068] The raw materials used in each of the Reference Examples, Examples, and Comparative Examples are shown below.

[0069] (A-PPS-1) Polyphenylene sulfide resin An autoclave equipped with a stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.94 kg (70.63 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), 0.513 kg (6.25 mol) of sodium acetate, and 3.82 kg of ion-exchanged water. The mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through. After distilling off 8.09 kg of water and 0.28 kg of NMP, the reaction vessel was cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0070] The mixture was then cooled to 200°C, and 10.34 kg (70.32 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen gas and heated from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. The reaction was continued at 270°C for 140 minutes. 2.67 kg (148.4 mol) of water was then injected while the mixture was cooled from 270°C to 250°C over 15 minutes. The mixture was then gradually cooled from 250°C to 220°C over 75 minutes, after which it was rapidly cooled to near room temperature and the contents were removed.

[0071] The contents were diluted with approximately 35 L of NMP, stirred at 85°C for 30 minutes, and filtered through an 80-mesh wire mesh (0.175 mm mesh size) to obtain a solid. The resulting solid was similarly washed and filtered with approximately 35 L of NMP. The resulting solid was diluted with 70 L of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. This procedure was repeated three times. The resulting solid and 32 g of acetic acid were diluted with 70 L of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh. The resulting solid was further diluted with 70 L of ion-exchanged water, stirred at 70°C for 30 minutes, and then filtered through an 80-mesh wire mesh to recover the solid. The resulting solid was dried at 120°C under a nitrogen stream to obtain dried PPS.

[0072] The obtained PPS resin (A-PPS-1) was held at 310°C for 5 minutes using a Toyo Seiki "Capilograph" (registered trademark), and the melt viscosity was measured under the conditions of a temperature of 310°C, a shear rate of 1216 / s, a capillary length of 10 mm, and a capillary diameter of 1 mm. The melt viscosity was found to be 60 Pa s.

[0073] (A-PPS-2) Polyphenylene sulfide resin An autoclave equipped with a stirrer and a bottom stop valve was charged with 8.27 kg (70.00 mol) of 47.5% sodium hydrosulfide, 2.91 kg (69.80 mol) of 96% sodium hydroxide, 11.45 kg (115.50 mol) of N-methyl-2-pyrrolidone (NMP), and 10.5 kg of ion-exchanged water. The mixture was gradually heated to 245°C over approximately 3 hours under atmospheric pressure while passing nitrogen through it. After distilling off 14.78 kg of water and 0.28 kg of NMP, the reaction vessel was cooled to 200°C. The amount of water remaining in the system per mole of charged alkali metal sulfide was 1.06 mol, including the water consumed in the hydrolysis of NMP. The amount of hydrogen sulfide released was 0.02 mol per mole of charged alkali metal sulfide.

[0074] The mixture was then cooled to 200°C, and 10.48 kg (71.27 mol) of p-dichlorobenzene and 9.37 kg (94.50 mol) of NMP were added. The reaction vessel was sealed under nitrogen gas and heated from 200°C to 270°C at a rate of 0.6°C / min while stirring at 240 rpm. After reacting at 270°C for 100 minutes, the bottom stopper valve of the autoclave was opened, and the contents were flushed into a vessel equipped with a stirrer over 15 minutes while pressurizing with nitrogen. The mixture was then stirred at 250°C for a while to remove most of the NMP.

[0075] The obtained cake and 90 liters of ion-exchanged water were placed in an autoclave equipped with a stirrer, and acetic acid was added to adjust the pH to 7. After the inside of the autoclave was purged with nitrogen, the temperature was raised to 192°C and maintained at that temperature for 30 minutes. The autoclave was then cooled, and the contents were removed.

[0076] The contents were filtered with a glass filter under suction, and then 76 liters of ion-exchanged water at 70°C was poured into the filter and filtered under suction to obtain a cake. The cake was dried at 120°C under a nitrogen stream to obtain a dried PPS.

[0077] The resulting PPS resin (A-PPS-2) was held at 310°C for 5 minutes using a Toyo Seiki "Capilograph" (registered trademark), and the melt viscosity was measured under the following conditions: temperature 310°C, shear rate 1216 / s, capillary length 10 mm, and capillary diameter 1 mm. The melt viscosity was 20 Pa s.

[0078] (A-Ole-1) Epoxy group-containing olefin copolymer: Ethylene-glycidyl methacrylate copolymer (Sumitomo Chemical's "Bondfast"® E) (A-Ole-2) Unmodified olefin copolymer: An ethylene-1-butene copolymer was used ("Tafmer" (registered trademark) A4085, manufactured by Mitsui Chemicals).

[0079] (Bl-1) Glass fiber: Chopped glass of E-glass (magnesium content determined by SEM-EDX was 1.3 mass%, calcium content 16.2 mass%, aluminum content 7.4 mass%, silicon content 26.0 mass%, sodium content 0.5 mass%, and oxygen content 48.6 mass%) was used, having a fiber length of 3 mm and a fiber diameter of 11 μm.

[0080] (Bl-2) Glass fiber bundle: A glass roving with a fiber diameter of 17 μm and E-glass (the magnesium content determined by SEM-EDX was 1.3 mass%, calcium content 16.2 mass%, aluminum content 7.4 mass%, silicon content 26.0 mass%, sodium content 0.5 mass%, and oxygen content 48.6 mass%) was used.

[0081] (Bh-1) High-elasticity glass fiber: Chopped glass was used, with a fiber length of 3 mm, a fiber diameter of 11 μm, and a magnesium content of 6.5 mass%, calcium content of 6.5 mass%, aluminum content of 10.5 mass%, silicon content of 27.5 mass%, and oxygen content of 49.0 mass%, as determined by SEM-EDX.

[0082] (Bh-2) High-elasticity glass fiber bundle: A glass roving was used, with a fiber diameter of 17 μm and a magnesium element content of 6.5 mass%, calcium element content of 6.5 mass%, aluminum element content of 10.5 mass%, silicon element content of 27.5 mass%, and oxygen element content of 49.0 mass%, as determined by SEM-EDX.

[0083] (Bh-3) High-elasticity glass fiber: Chopped glass was used, with a fiber length of 3 mm, a fiber diameter of 11 μm, and a magnesium content of 10.7 mass%, calcium content of 0.8 mass%, aluminum content of 11.2 mass%, silicon content of 29.8 mass%, and oxygen content of 47.5 mass%, as determined by SEM-EDX.

[0084] (C-1) Calcium carbonate was used as a non-fibrous filler (KSS-1000, manufactured by Kalfin Co., Ltd.). (d-1) Organic silane compound containing an epoxy group: 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane was used (manufactured by Shin-Etsu Silicones: KBM303).

[0085] [Reference Example 1] (X'-1) Glass fiber reinforced PPS resin composition (unused material) A mixture of 65% by weight of PPS resin (A-PPS-1), 30% by weight of glass fiber (Bl-1), 2.5% by weight of olefin polymer (A-Ole-1), and 2.5% by weight of olefin polymer (A-Ole-2) was melt-kneaded with 0.3 parts by weight of organosilane compound (d-1) using a vacuum-vented TEX30α twin-screw extruder (L / D=45, 3 kneading zones) manufactured by The Japan Steel Works, Ltd. (JSW) with a side feed of glass fiber. The extruder was melt-kneaded at a cylinder temperature of 300°C and a screw rotation speed of 200 rpm to obtain PPS resin composition (X'-1). The ash content was 30% by weight.

[0086] [Reference Example 2] (X-1) Crushed molded product pellets The (X'-1) PPS resin composition was dried in a hot air dryer at 130°C for 3 hours and then injection-molded into ISO (1A) dumbbell test specimens using a Sumitomo Heavy Industries SE75-DUZ injection molding machine at a cylinder temperature of 310°C, a mold temperature of 140°C, and a screw rotation speed of 100 rpm. The resulting sprue / runner (corresponding to the molded product) was crushed in a crusher to obtain crushed molded product fragments with a major axis dimension of 10 mm or less. The crushed molded product fragments were then melt-kneaded in a Japan Steel Works TEX30α twin-screw extruder (L / D = 45, one kneading section) equipped with a vacuum vent at a cylinder temperature of 300°C and a screw rotation speed of 150 rpm to obtain crushed molded product pellets (X-1). The ash content was 30% by mass.

[0087] Reference Example 3: (YZ-1) Glass fiber reinforced PPS resin composition Except for using the glass fiber (Bh-1), melt-kneading was carried out under the same conditions as in Reference Example 1 to obtain a glass fiber-reinforced PPS resin composition (YZ-1). The ash content was 30 mass%.

[0088] [Reference Examples 1 to 3, Examples 1 to 5, Comparative Examples 1 to 3] The virgin material, (X) crushed molded product, and (YZ) glass fiber reinforced resin composition were dry blended in the proportions shown in Table 1. The resulting resin composition was then subjected to the evaluations of the above items (1) to (6) and each property was measured.

[0089] [Table 1]

[0090] Comparison of the Reference Examples, Examples, and Comparative Examples in Table 1 above reveals the following.

[0091] Compared to Reference Example 1 (virgin material), the glass fiber reinforced recycled thermoplastic resin composition obtained from the crushed molded product (X) in Reference Example 2 exhibited reduced mechanical properties due to a decrease in glass fiber length caused by recycling.

[0092] In Comparative Examples 1 to 3, by mixing virgin material with crushed (X) molded product, glass fiber reinforced recycled thermoplastic resin compositions were obtained that had improved glass fiber length and various properties compared to Reference Example 2, but they were not equivalent to Reference Example 1 (virgin material), and the property recovery effect was insufficient.

[0093] In Examples 1 to 5, by mixing (X) crushed molded article material with (YZ) glass fiber reinforced thermoplastic resin composition, the mass ratio Bl / Bh of (B) glass fiber in the resulting glass fiber reinforced recycled thermoplastic resin composition was increased, and glass fiber reinforced recycled thermoplastic resin compositions with a higher property recovery effect were obtained compared to Comparative Examples 1 to 3. In particular, glass fiber reinforced recycled thermoplastic resin compositions with excellent tensile strength derived from the high modulus glass fiber Bh were obtained. Furthermore, as Bl / Bh increased, the properties became closer to those of virgin material, making them suitable for closed recycling in which virgin material is molded in the same mold.

[0094] Furthermore, Reference Example 3, which was composed only of high-modulus glass fiber Bh, was excellent in mechanical properties but poor in fluidity, while Examples 1 to 5 were found to have an excellent balance between mechanical properties and fluidity.

[0095] [Reference Example 4] (X'-2) Long glass fiber reinforced PPS resin composition (unused material) PPS resin composition pellets were obtained by melt-kneading 93% by weight of PPS resin (A-PPS-1), 3.5% by weight of olefin polymer (A-Ole-1), 3.5% by weight of olefin polymer (A-Ole-2), and 0.4 parts by weight of organosilane compound (d-1) per 100 parts by weight of the PPS resin and olefin polymer combined in a vacuum-vented TEX30α twin-screw extruder (L / D = 45, 3 kneading zones) manufactured by The Japan Steel Works, Ltd. at a cylinder temperature of 300°C and a screw rotation speed of 200 rpm. The resulting pellets were then melt-kneaded in a single-screw extruder at 300°C to a molten state and extruded into a crosshead die attached to the tip of the extruder. Continuous glass fiber bundles (Bl-2) were simultaneously fed into the crosshead die, yielding strands in which a fixed amount of PPS resin composition was coated around the glass fiber bundle per unit length, in a manner similar to that of an electric wire coating method. The coated strand was cooled in a water-cooled bath and cut into 7 mm lengths to obtain pellets of a core-sheath long glass fiber reinforced PPS resin composition (X'-2). The ash content was 30 mass %.

[0096] Reference Example 5 (YZ-2) Long Glass Fiber Reinforced PPS Resin Composition A glass fiber-reinforced PPS resin composition (YZ-2) was obtained under the same production conditions as in Reference Example 4, except that the glass fiber (Bh-2) was used as the glass fiber. The ash content was 30 mass%.

[0097] [Reference Examples 4 to 5, Examples 6 to 8, Comparative Examples 4 to 6] The virgin material, (X) crushed molded product, and (YZ) glass fiber reinforced resin composition were dry blended in the proportions shown in Table 2. The resulting resin composition was then subjected to the evaluations of the above items (1) to (6) and each property was measured.

[0098] [Table 2]

[0099] Comparison of the Reference Examples, Examples, and Comparative Examples in Table 2 above reveals that even when a long glass fiber reinforced resin composition is used as the (YZ) glass fiber reinforced resin composition, the property recovery effect of the high elasticity glass fiber Bh is recognized, and that a fiber length and impact strength exceeding those of Reference Example 1 (unused material) can be obtained.

[0100] [Reference Example 6] (X'-3) PPS resin composition (unused material) A glass fiber-reinforced PPS resin composition (X'-3) was obtained in the same manner as in Reference Example 1, except that 45 mass% of PPS resin (A-PPS-2), 30 mass% of glass fiber (Bl-1), 2.5 mass% of olefin polymer (A-Ole-1), 2.5 mass% of olefin polymer (A-Ole-2), 20 mass% of calcium carbonate (C-1), and 0.3 mass parts of organosilane compound (d-1) were used per 100 mass parts combined of PPS resin, glass fiber, olefin polymer, and calcium carbonate. The ash content was 50 mass%.

[0101] [Reference Example 7] (X-2) Crushed molded product pellets Pellets (X-2) of crushed molded articles were obtained in the same manner as in Reference Example 2, except that the (X'-3) PPS resin composition was used instead of the (X'-1) PPS resin composition. The ash content was 50% by mass.

[0102] Reference Example 8: (YZ-3) Glass fiber reinforced PPS resin composition A glass fiber reinforced PPS resin composition (YZ-2) was obtained by melt-kneading under the same conditions as in Reference Example 6, except that the glass fiber (Bh-1) was used as the glass fiber. The ash content was 50 mass%.

[0103] [Reference Examples 6 to 8, Examples 9 to 11, Comparative Examples 7 to 9] The virgin material, (X) crushed molded product, and (YZ) glass fiber reinforced resin composition were dry blended in the proportions shown in Table 3. The resulting resin composition was then subjected to the evaluations of the above items (1) to (7) and each property was measured.

[0104] [Table 3]

[0105] Comparison of the Reference Examples, Examples, and Comparative Examples in Table 3 above clearly demonstrates that the effects of the present invention can be achieved even when the melt viscosity of the PPS resin is different or when a non-fibrous filler is blended. Furthermore, blending high-elasticity glass fiber Bh improved heat cycle resistance, making it possible to upcycle the material compared to virgin materials.

[0106] [Reference Example 9] (X'-4) PPS resin composition (unused material) A glass fiber-reinforced PPS resin composition (X'-4) was obtained in the same manner as in Reference Example 1, except that 60 mass% of PPS resin (A-PPS-1), 40 mass% of glass fiber (Bl-1), and 0.3 mass parts of organosilane compound (d-1) were used per 100 mass parts of the PPS resin and glass fiber combined. The ash content was 40 mass%.

[0107] [Reference Example 10] (X-3) Crushed molded product pellets Pellets (X-3) of crushed molded articles were obtained in the same manner as in Reference Example 2, except that the (X'-4) PPS resin composition was used instead of the (X'-1) PPS resin composition. The ash content was 40% by mass.

[0108] Reference Example 11: (YZ-4) Glass fiber reinforced PPS resin composition A glass fiber reinforced PPS resin composition (YZ-4) was obtained by melt-kneading under the same conditions as in Reference Example 6, except that the glass fiber (Bh-1) was used as the glass fiber. The ash content was 40 mass%.

[0109] [Reference Examples 9 to 11, Examples 12 to 14, Comparative Examples 10 to 12] The virgin material, (X) crushed molded product, and (YZ) glass fiber reinforced resin composition were dry blended in the proportions shown in Table 4. The resulting resin composition was then subjected to the evaluations of the above items (1) to (6) and each property was measured.

[0110] [Table 4]

[0111] Comparison of the Reference Examples, Examples and Comparative Examples in Table 4 above makes it clear that the effects of the present invention can be obtained even when the blending amount of glass fiber is different or when no olefin copolymer is blended.

[0112] [Example 15] Glass fiber reinforced PPS resin composition A PPS resin composition was obtained by melt-kneading 50% by weight of (X-1) crushed molded product, 32.5% by weight of (A-PPS-1) PPS resin, 15% by weight of (Bh-1) high-modulus glass fiber, 1.25% by weight of (A-Ole-1) olefin polymer, 1.25% by weight of (A-Ole-2) olefin polymer, and 0.3 parts by weight of (d-1) organosilane compound per 100 parts by weight of PPS resin, glass fiber, and olefin polymer, using a vacuum-vented TEX30α twin-screw extruder (L / D=45, 3 kneading zones) manufactured by The Japan Steel Works, Ltd. (JSW) at a cylinder temperature of 300°C and a screw rotation speed of 200 rpm. The glass fiber was added via side feed. The ash content was 30% by weight.

[0113] [Comparative Example 13] Glass fiber reinforced PPS resin composition A PPS resin composition was obtained under the same production conditions as in Example 15, except that (Bl-1) glass fiber was used as the glass fiber. The ash content was 30 mass %.

[0114] [Table 5]

[0115] From a comparison of the Reference Examples, Examples, and Comparative Examples in Table 5 above, it is clear that the effects of the present invention can be obtained even when a glass fiber reinforced recycled thermoplastic resin composition is produced by melt kneading.

[0116] Reference Example 12: (YZ-5) Glass fiber reinforced PPS resin composition Except for using the (Bh-3) glass fiber as the glass fiber, melt-kneading was carried out under the same conditions as in Reference Example 1 to obtain a (YZ-5) glass fiber-reinforced PPS resin composition, which had an ash content of 30 mass%.

[0117] [Reference Examples 1 to 3 and 12, Examples 2 and 16, Comparative Example 2] The virgin material, (X) crushed molded product, and (YZ) glass fiber reinforced resin composition were dry blended in the proportions shown in Table 6. The resulting resin composition was then subjected to the evaluations of the above items (1) to (6) and each property was measured.

[0118] [Table 6]

[0119] Comparisons between Reference Examples 3 and 12, and between Examples 2 and 16 and Comparative Example 2, confirmed that the use of high-modulus glass fibers with a higher magnesium element content had a further effect on restoring the properties of the glass fiber-reinforced recycled PPS resin composition.

[0120] The effects of the present invention specifically explained in these examples are the property recovery effects derived from the high-elasticity glass fiber, and therefore it is clear that the effects of the present invention can be obtained regardless of the type or amount of thermoplastic resin blended.

Claims

1. A glass fiber-reinforced recycled thermoplastic resin composition containing 40 to 90% by mass of (A) a thermoplastic resin and 10 to 60% by mass of (B) glass fiber, wherein the (A) thermoplastic resin contains a thermoplastic resin derived from at least one selected from process waste materials of a glass fiber-reinforced thermoplastic resin composition obtained by blending a thermoplastic resin and glass fiber, and recovered molded products recovered after a molded product made of the glass fiber-reinforced thermoplastic resin composition has been used as a product, and the (B) glass fiber contains glass fiber Bl (hereinafter sometimes referred to as glass fiber Bl) having a magnesium element content of less than 3% by mass and glass fiber Bh (hereinafter sometimes referred to as high-modulus glass fiber Bh) having a magnesium element content of 3% to 15% by mass, and the mass ratio Bl / Bh of the glass fiber Bl to the high-modulus glass fiber Bh contained in the glass fiber-reinforced recycled thermoplastic resin composition is 0.1 to 10.

0.

2. (B) The glass fiber reinforced recycled thermoplastic resin composition according to claim 1, wherein the ratio (Lw / Ln) of the weight average fiber length (Lw) to the number average fiber length (Ln) of the glass fiber is 1.30 or more and 3.00 or less.

3. 3. The glass fiber reinforced recycled thermoplastic resin composition according to claim 1, wherein the thermoplastic resin (A) comprises at least one selected from the group consisting of polyphenylene sulfide, polyamide, polybutylene terephthalate, and liquid crystal polyester.

4. A molded article made from the glass fiber reinforced recycled thermoplastic resin composition according to claim 1 or 2.

5. 5. The molded article according to claim 4, having a thickness of 2 mm or more and 15 mm or less.

6. A method for producing a glass fiber-reinforced recycled thermoplastic resin composition, comprising crushing at least one selected from process waste of a glass fiber-reinforced thermoplastic resin composition obtained by blending a thermoplastic resin and glass fibers, and recovered molded products recovered after a molded product made of the glass fiber-reinforced thermoplastic resin composition has been used as a product, to obtain (X) crushed molded product, and mixing the crushed molded product with (X), (Y) a thermoplastic resin that is substantially the same as the thermoplastic resin constituting the (X) crushed molded product (hereinafter sometimes referred to as (Y) substantially the same thermoplastic resin), and (Z) glass fiber Bh having a magnesium element content of 3% by mass or more and 15% by mass or less (hereinafter sometimes referred to as high-modulus glass fiber Bh).

7. 7. The method for producing a glass fiber-reinforced recycled thermoplastic resin composition according to claim 6, wherein (Y) substantially the same thermoplastic resin and (Z) high-modulus glass fiber Bh are mixed to obtain a glass fiber-reinforced thermoplastic resin composition (YZ), and then the glass fiber-reinforced thermoplastic resin composition (YZ) and crushed molded product (X) are mixed.

8. 8. The method for producing a glass fiber-reinforced recycled thermoplastic resin composition according to claim 7, wherein the glass fiber-reinforced thermoplastic resin composition (YZ) is a long glass fiber-reinforced thermoplastic resin composition.

9. The method for producing a fiber-reinforced recycled thermoplastic resin composition according to claim 6 or 7, wherein the thermoplastic resin comprises at least one selected from the group consisting of polyphenylene sulfide, polyamide, polybutylene terephthalate, and liquid crystal polyester.

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