Horizontal component for automobile and manufacturing method thereof

Abstract

Provided is a horizontal member for an automobile, which can be easily molded and has little resin drop after a combustion test. The automotive horizontal member contains reinforcing fibers having a weight-average fiber length of 5-100 mm, a resin, and a flame retardant, the flame retardant being 1-50 parts by mass per 100 parts by mass of the resin, and the automotive horizontal member satisfying the following (a)-(b). (a) The tensile strength retention rate represented by formula (1) is 0.04% or more. The tensile strength retention rate (%) = (tensile strength B after combustion / tensile strength A before combustion) * 100 formula (1) (b): in a test piece after a combustion test having a width of 25 mm, the amount of work per unit basis weight in a tensile test is 0.5 * 10 <-3 > [(N * mm) / (g / m2)] or more and 100 * 10 <-3 > [(N * mm) / (g / m2)] or less, and the maximum load per unit basis weight is 1.1 * 10 <-3 > [N / (g / m2)] or more.

Description

Technical Field

[0001] The present invention relates to a horizontal component for automobiles comprising reinforcing fibers having a weight-average fiber length of 5 mm to 100 mm, a resin, and a flame retardant, and a method for producing the same. Background Art

[0002] Molded materials using reinforcing fibers as reinforcement materials have high tensile strength and tensile elastic modulus, and a small linear expansion coefficient, so they have excellent dimensional stability, and further excellent heat resistance, chemical resistance, fatigue resistance, wear resistance, etc. Therefore, molded materials using reinforcing fibers are widely used in automobiles, sports and leisure, aerospace, general industrial uses, etc.

[0003] Patent Document 1 describes a pressable sheet and a pressable sheet molded product obtained by a papermaking method having excellent flame retardancy.

[0004] Patent Documents 2 and 3 describe flame-retardant resin compositions using a product obtained by needle-punching a spiral mat or sheet of continuous glass fibers.

[0005] Patent Document 4 describes a self-flame-extinguishing resin molded body obtained from a resin composition containing a phosphorus-based flame retardant and glass fibers in a polyolefin-based resin.

[0006] Patent Document 5 describes a carbon fiber composite material with a carbon fiber sheet as a reinforcing material and a thermoplastic resin as a matrix resin. The work per unit area weight of a 25 mm wide test piece of the carbon fiber sheet in a tensile test is 1×10 -3 ~30×10 -3 [(N·mm) / (g / m 2 )].

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 11-49869

[0010] Patent Document 2: Japanese Patent Application Laid-Open No. 63-183845

[0011] Patent Document 3: WO2022 / 220303

[0012] Patent Document 4: WO2020 / 071420

[0013] Patent Document 5: WO2013 / 179891 Summary of the invention

[0014] Technical problem that the invention aims to solve

[0015] However, in the invention described in Patent Document 1, since the papermaking method is used for manufacturing, the springback during forming becomes too large and the formability is poor. In addition, there is no research on the use as a horizontal component for automobiles. As further problems of the invention described in Patent Document 1, the following aspects can be listed:

[0016] (1) Too much flame retardant is added, so the formability is poor and the manufacturing cost is high;

[0017] (2) As a flame retardant, a large amount of metal hydrate is also contained, so the specific gravity of the obtained molded body is too large;

[0018] (3) When a halogen flame retardant is used as a flame retardant, there is a concern that harmful substances such as phosphine (phosphine) may be generated.

[0019] (4) In the case of a horizontal component for an automobile, it is necessary to prevent the component from sagging (sometimes referred to as resin dripping) during combustion. This problem becomes significant particularly when the horizontal component for an automobile is large in size.

[0020] In the inventions described in Patent Documents 2 and 3, since a product obtained by needle-punching a spiral mat or sheet of continuous glass fibers is utilized, there are problems such as the easy generation of surface fuzz, low fluidity and deterioration of formability, and an increased specific gravity of the obtained molded body when a metal hydrate is used.

[0021] In the invention described in Patent Document 4, injection molded bodies are mainly used, so the fiber length is too short. Therefore, there is little entanglement between the fibers, and large resin drips will occur when the molded body is subjected to a combustion test. When a molded body with large resin drips is used, for example, as a battery cover, there is a risk of battery explosion.

[0022] In the invention described in Patent Document 5, the value of the amount of work is too large. Therefore, the springback is too large, the formability is extremely deteriorated, and the flame retardant properties as a horizontal part for automobiles are not considered at all.

[0023] Technical solutions to the problem

[0024] In order to solve the above-mentioned problems, the present invention provides the following solutions.

[0025] 1. A horizontal component for an automobile, characterized in that:

[0026] Contains: reinforcing fibers with a weight-average fiber length of 5 mm or more and 100 mm or less, resin, and flame retardant,

[0027] The flame retardant is contained in an amount of 1 part by mass or more and 50 parts by mass or less relative to 100 parts by mass of the resin.

[0028] The above-mentioned horizontal component for automobiles satisfies the following (a) to (b):

[0029] (a): The tensile strength retention rate represented by the formula (1) is greater than 0.03%.

[0030] Tensile strength retention rate (%) = (tensile strength B after combustion ÷ tensile strength A before combustion) × 100 Formula (1)

[0031] (b): For the test piece with a width of 25 mm after the combustion test, the amount of work per unit area weight in the tensile test was 0.5×10 -3 [(N·mm) / (g / m 2 )] and above and 100×10 -3 [(N·mm) / (g / m 2 )] and the maximum load per unit area is 1.1×10 -3 [N / (g / m 2 )]above.

[0032] 2. The horizontal member for an automobile according to item 1 above, wherein:

[0033] In the tensile test of the test piece having a width of 25 mm after the combustion test, the maximum load per unit area weight was obtained in the range of strain greater than 0% and less than 2%.

[0034] 3. The horizontal member for automobile according to 1 or 2 above, wherein:

[0035] The above-mentioned horizontal component for automobiles satisfies the following (c),

[0036] (c): In the tensile test of the test piece with a width of 25 mm after the combustion test, the load [N / (g / m 2 The average change rate of )] is 0.1×10 -3 [N / (g / m 2 )] and less than 100×10 -3 [N / (g / m 2 )].

[0037] 4. The horizontal member for automobile according to item 3 above, wherein:

[0038] The above-mentioned horizontal component for automobiles satisfies the following (d),

[0039] (d): In the tensile test of the test piece with a width of 25 mm after the combustion test, the load [N / (g / m 2 The average change rate of )] is -1.0×10 -3 [N / (g / m 2)] and above -0.01×10 -3 [N / (g / m 2 )] below the range.

[0040] 5. The automotive horizontal member according to any one of 1 to 4 above, wherein:

[0041] The above resin is a thermoplastic resin.

[0042] 6. The automotive horizontal member according to any one of 1 to 5 above, wherein:

[0043] The above resin is polypropylene resin.

[0044] 7. The automotive horizontal member according to any one of 1 to 6 above, wherein:

[0045] The above-mentioned reinforcing fibers are glass fibers.

[0046] 8. The automotive horizontal member according to any one of 1 to 7 above, wherein:

[0047] The above-mentioned horizontal component for automobile is a battery cover or a battery bottom protection cover.

[0048] 9. The automotive horizontal member according to any one of 1 to 8 above, wherein:

[0049] The resin is a thermoplastic resin, and the automotive horizontal member has a rebound coefficient of 1.2 or more and 8.0 or less.

[0050] 10. A method for manufacturing a horizontal component for an automobile, characterized in that:

[0051] The horizontal component for automobiles described in any one of 1 to 9 is manufactured by cold pressing a molding material containing reinforcing fibers and a thermoplastic resin.

[0052] The molding material has a springback factor of 1.2 or more and 8.0 or less.

[0053] 11. The method for manufacturing a horizontal member for an automobile according to 10 above, wherein:

[0054] The reinforcing fibers are glass fibers, and the glass fibers GFs of single-end rovings and the glass fibers GFm of multi-end rovings are mixed at a volume ratio of GFm:GFs of 90:10 to 50:50 to prepare a molding material.

[0055] Effects of the Invention

[0056] In the automobile horizontal member of the present invention, since the following (a) and (b) are satisfied, the automobile horizontal member has excellent moldability and also has little resin dripping after a combustion test.

[0057] (a) The tensile strength retention rate represented by formula (1) is 3% or more.

[0058] Tensile strength retention rate (%) = (tensile strength B after combustion ÷ tensile strength A before combustion) × 100 Formula (1)

[0059] (b) The work per unit area weight of the test piece with a width of 25 mm after the combustion test in the tensile test is 0.5×10 -3 [(N·mm) / (g / m 2 )] and above and 100×10 -3 Below [(N·mm) / (g / m 2 )]. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a schematic diagram showing a state in which a combustion test is performed on a test piece.

[0061] Figure 2 This is a schematic diagram showing an example of a vehicle structure including a battery bottom protection cover under a battery box as an example in which the horizontal member of the present invention is used for a battery cover or a battery tray.

[0062] Figure 3 This is an example of a graph showing a load-strain curve in a tensile test of the test piece of Example 1.

[0063] Figure 4 This is an example of a graph showing a load-strain curve in a tensile test of Example 5. DETAILED DESCRIPTION

[0064] Hereinafter, the present invention will be described in detail.

[0065] [Reinforcement Fiber]

[0066] In the present specification, the reinforcing fiber is preferably at least one selected from carbon fiber, aramid fiber, and glass fiber. More preferably, the reinforcing fiber is carbon fiber or glass fiber.

[0067] [Carbon Fiber]

[0068] 1. All carbon fiber

[0069] As the carbon fiber used in the present invention, polyacrylonitrile (PAN) carbon fiber, petroleum coal tar carbon fiber, rayon carbon fiber, cellulose carbon fiber, lignin carbon fiber, phenolic carbon fiber, etc. are generally known, but in the present invention, any of these carbon fibers can be preferably used. Among them, in the present invention, polyacrylonitrile (PAN) carbon fiber is preferably used from the aspect of excellent tensile strength. As PAN carbon fiber, for example, carbon fiber "Tenax" (registered trademark) STS40-24KS (average fiber diameter 7 μm) manufactured by Teijin Co., Ltd. can be used.

[0070] 2. Carbon fiber sizing agent

[0071] The carbon fiber used in the present invention may have a sizing agent attached to the surface. When using carbon fiber with a sizing agent attached, the type of the sizing agent can be appropriately selected according to the type of carbon fiber and the type of resin used in the automotive horizontal member, and is not particularly limited.

[0072] [Fiberglass]

[0073] The case where the reinforcing fiber used in the present invention is glass fiber will be described.

[0074] 1. Glass fiber overall

[0075] The glass fiber used in the present invention may be any glass fiber as long as it is generally called glass fiber. The glass composition of A glass, C glass, E glass, etc. is not particularly limited, and may contain components such as TiO2, SO3, P2O5, etc. as appropriate. As the glass fiber, for example, RV P204-4800TEX manufactured by Owens Corning can be used.

[0076] 2. Sizing agent for glass fiber

[0077] The glass fiber used in the present invention may have a sizing agent attached to the surface. When using glass fibers with a sizing agent attached, the type of the sizing agent can be appropriately selected according to the type of glass fiber and the type of resin, and is not particularly limited. Glass fibers are preferably pretreated with conventionally known coupling agents such as organosilane compounds, organotitanium compounds, organoborane compounds, and epoxy compounds.

[0078] 3. In the preparation of the molding material of the present invention, it is preferred that the glass fiber GFs of the single-end roving and the glass fiber GFm of the multi-end roving be mixed in a ratio of GFm:GFs of 50:50 to 90:10 to prepare the molding material. If the ratio of GFm is 50% or more, it is easy to set the upper limit value of the work amount below. If GFm is 90% or less, it is easy to set the lower limit value of the work amount below.

[0079] Multi-end roving refers to roving in which the ends of the glass fibers are not aligned. In the glass fibers of multi-end roving, there are multiple (multi) ends. Single-end roving refers to roving in which the ends of the glass fibers are aligned to one. In the glass fibers of single-end roving, there is one (single) end.

[0080] [Dispersion in the in-plane direction]

[0081] The reinforcing fibers contained in the automotive horizontal member are preferably dispersed in the in-plane direction. In addition, the automotive horizontal member of the present invention is preferably manufactured by cold pressing a molding material containing reinforcing fibers and a thermoplastic resin. In this case, the reinforcing fibers contained in the molding material are more preferably dispersed in the in-plane direction.

[0082] Dispersing the reinforcing fibers in the in-plane direction means dispersing the reinforcing fibers so that the fiber axes of the reinforcing fibers face the in-plane direction. The angle formed between the fiber axes of the reinforcing fibers and the in-plane direction is preferably 45° or less.

[0083] 1. In-plane direction

[0084] The formed material used for manufacturing the horizontal member for automobiles is preferably a plate-shaped material. The in-plane direction refers to an indefinite direction of a parallel plane perpendicular to the plate thickness direction of the formed material.

[0085] 2. Randomly scattered in two dimensions

[0086] The reinforcing fibers are preferably randomly dispersed in the two-dimensional direction in the in-plane direction. In the case of press molding without flowing the molding material (non-flow molding), the morphology of the reinforcing fibers is roughly maintained before and after molding. In the case of non-flow molding, it is preferred that the reinforcing fibers contained in the molding material are randomly oriented in two dimensions, so that the reinforcing fibers contained in the horizontal component (molded body) for automobiles obtained by molding the molding material are also randomly dispersed in the two-dimensional direction in the in-plane direction.

[0087] Here, two-dimensional random dispersion means that the reinforcing fibers are not oriented in a specific direction such as one direction in the in-plane direction of the molding material, but are randomly oriented, and are arranged in the sheet surface in a manner that does not show specific directionality as a whole. The molding material (or molded body) obtained using the two-dimensionally randomly dispersed discontinuous fibers is a molding material (or molded body) that does not have anisotropy in the plane and is substantially isotropic.

[0088] The degree of orientation of two-dimensional randomness is evaluated by finding the ratio of the tensile modulus in two mutually orthogonal directions. For any direction of the forming material (or formed body) and the direction orthogonal thereto, if the ratio (Eδ) obtained by dividing the larger of the values ​​of the tensile modulus measured respectively by the smaller is 5 or less, more preferably 2 or less, and further preferably 1.5 or less, it can be evaluated as a two-dimensional random dispersion of reinforcing fibers. In the case where a horizontal component for an automobile includes a curved surface, as an evaluation method for two-dimensional random dispersion in the in-plane direction, it can be cured after being heated to a softening temperature or above and restored to a flat plate shape. Then, a test piece is cut out to find the tensile modulus, and the random dispersion state in the two-dimensional direction can be confirmed.

[0089] [Fiber length of reinforcing fibers]

[0090] The automobile horizontal member of the present invention has a weight average fiber length of 5 mm or more and 100 mm or less.

[0091] For the molding material and the horizontal component for automobiles (molded body), the weight average fiber length does not change before and after molding. Therefore, if the weight average fiber length of the reinforcing fibers contained in the horizontal component for automobiles (molded body) is investigated, the weight average fiber length Lw of the reinforcing fibers contained in the molding material can be known.

[0092] The lower limit of the weight average fiber length of the reinforcing fiber is preferably 7 mm or more, more preferably 10 mm or more. On the contrary, the upper limit of the weight average fiber length is preferably 80 mm or less, more preferably 70 mm or less. When the weight average fiber length is 5 mm or more, the mechanical strength of the obtained fiber reinforced resin part is not easy to decrease, so it is preferred. If the weight average fiber length is 100 mm or less, when the molding material is press-formed and manufactured, the fluidity of the material is not easy to decrease, and it is easy to make a fiber reinforced resin part in a desired shape.

[0093] The preferred range of the weight average fiber length of the reinforcing fibers is 5 mm to 80 mm, and more preferably 10 mm to 60 mm.

[0094] [Number average fiber length Ln and weight average fiber length Lw]

[0095] Generally, when the fiber length of each reinforcing fiber is defined as Li, the number average fiber length Ln and the weight average fiber length Lw can be obtained by the following formulas (X) and (Y). The units of the number average fiber length Ln and the weight average fiber length Lw are mm.

[0096] [Number 1]

[0097]

[0098]

[0099] Here, "I" represents the number of measured reinforcing fibers.

[0100] When the fiber length is constant, the number average fiber length and the weight average fiber length are the same value. The reinforcing fibers from the door inner panel can be extracted by, for example, performing a heating treatment at about 500° C. for 1 hour and removing the resin in a furnace.

[0101] The average fiber length can be determined based on the formula (X) by measuring the fiber lengths of 100 fibers randomly extracted from the door inner panel to 1 mm using a vernier caliper or the like, for example.

[0102] In the case of containing short fibers that cannot be measured with a vernier caliper, after removing the resin, the obtained reinforcing fibers are put into water containing a surfactant and stirred sufficiently by ultrasonic vibration. The stirred dispersion can be randomly collected with a measuring spoon to obtain a sample for evaluation, and the length of 3000 fibers can be measured using an image analyzer LuzexAP manufactured by Nireco. The measured value of the fiber length can be used to obtain the number average fiber length Ln and the weight average fiber length Lw in the same manner as the above formula (X) and formula (Y).

[0103] [Volume ratio of reinforcing fibers]

[0104] The reinforcing fiber volume ratio (Vf) of the reinforcing fibers contained in the horizontal member for an automobile can be calculated by the following formula (3).

[0105] Reinforcement fiber volume ratio (Vf) = 100 × reinforcement fiber volume / (reinforcement fiber volume + resin volume) Formula (3)

[0106] The volume ratio of the reinforcing fibers is not particularly limited, but the volume ratio (Vf) of the reinforcing fibers is preferably 10 to 60 Vol%, more preferably 20 to 50 Vol%, and still more preferably 25 to 45 Vol%.

[0107] [Analysis of reinforcing fiber volume ratio (Vf)]

[0108] The analysis of the reinforcing fiber volume ratio is not limited, and can be measured as follows.

[0109] A sample was cut out from a horizontal member for automobiles, and the resin was burned in a furnace at 500°C for 1 hour to remove the resin. The mass of the sample before and after the treatment was weighed to calculate the mass of the reinforcing fiber and the mass of the resin. Next, the volume of the reinforcing fiber was calculated by dividing the mass of the reinforcing fiber by the density of the reinforcing fiber, and the volume of the resin was calculated by dividing the mass of the resin by the density of the resin. Next, the ratio Vf of the volume of the reinforcing fiber to the total volume of the reinforcing fiber and the resin was calculated.

[0110] [Resin]

[0111] The resin contained in the automotive horizontal member may be a thermosetting resin or a thermoplastic resin.

[0112] 1. Thermoplastic resin

[0113] 1.1 Overview

[0114] When the resin used is a thermoplastic resin, its type is not particularly limited, and a resin having a desired softening point or melting point can be appropriately selected and used. As the above-mentioned thermoplastic resin, a thermoplastic resin having a softening point in the range of 80°C to 350°C, preferably 100°C to 350°C, and more preferably 180°C to 350°C is generally used, but it is not limited thereto.

[0115] Examples of the thermoplastic resin include polyolefin resins, polystyrene resins, polyamide resins, polyester resins, polyacetal resins (polyoxymethylene resins), polycarbonate resins, (meth)acrylic resins, polyarylate resins, polyphenylene ether resins, polyimide resins, polyether nitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyether ketone resins, thermoplastic polyurethane resins, fluorine-based resins, and thermoplastic polybenzimidazole resins.

[0116] The thermoplastic resin used in the door inner panel of the present invention may be only one kind or two or more kinds. As a method of using two or more thermoplastic resins together, for example, there can be cited: a method of using thermoplastic resins having different softening points or melting points together, a method of using thermoplastic resins having different average molecular weights together, etc., but it is not limited thereto.

[0117] When a thermoplastic resin is used, a polyolefin resin is more preferably used, and a polypropylene resin is further preferably used.

[0118] 2. Thermosetting resin

[0119] The resin of the present invention may also be a thermosetting resin. In this case, the molding material may also be a sheet molding compound (sometimes referred to as SMC) using reinforcing fibers. Since the sheet molding compound has good formability, it can be easily formed even into a complex shape. The flowability and shapeability of the sheet molding compound are higher than those of continuous fibers, and ribs and protrusions can be easily made.

[0120] [Flame retardant]

[0121] 1. The automotive horizontal member of the present invention contains a flame retardant. The flame retardant is not particularly limited, and examples thereof include phosphorus flame retardants, bromine flame retardants, antimony flame retardants, and the like. Among them, phosphorus flame retardants are preferred from the viewpoint of improving flame blocking properties. In addition, in the classification focusing on the action mechanism of the flame retardant, the flame retardant is preferably an intumescent flame retardant from the viewpoint of improving flame blocking properties.

[0122] 2. Phosphorus flame retardants

[0123] The phosphorus-based flame retardant is a phosphorus compound, that is, a compound containing a phosphorus atom in its molecule. The phosphorus-based flame retardant forms char when the resin composition is burned, thereby exhibiting a flame retardant effect.

[0124] The phosphorus flame retardant may be a known phosphorus flame retardant, for example, (poly)phosphates, (poly)phosphate esters, etc. Here, "(poly)phosphate" means phosphate or polyphosphate, and "(poly)phosphate ester" means phosphate ester or polyphosphate ester. It should be noted that the phosphorus flame retardant is preferably solid at 80°C.

[0125] As the phosphorus flame retardant, (poly)phosphates are preferred from the aspect of flame retardancy. Examples of (poly)phosphates include ammonium polyphosphate, melamine polyphosphate, piperazine polyphosphate, piperazine orthophosphate, melamine pyrophosphate, piperazine pyrophosphate, melamine orthophosphate, calcium phosphate, magnesium phosphate, and the like.

[0126] In addition, in the above examples, compounds obtained by replacing melamine or piperazine with other nitrogen compounds can also be used. Examples of other nitrogen compounds include N,N,N',N'-tetramethyldiaminomethane, ethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-diethylethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, tetramethylenediamine, pentaethylenediamine, and 1,2-propylenediamine. Methyldiamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, trans-2,5-dimethylpiperazine, 1,4-bis(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, acetoguanamine, benzoguanamine, propenylguanamine, 2,4-diamino-6-nonyl-1,3,5-triazine, 2,4-diamino- 6-Hydroxy-1,3,5-triazine, 2-amino-4,6-dihydroxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-ethoxy-1,3,5-triazine, 2,4-diamino-6-propoxy-1,3,5-triazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-mercapto-1, 3,5-triazine, 2-amino-4,6-dimercapto-1,3,5-triazine, ammeline, benzoguanamine, acetoguanamine, o-phthaloguanamine, melamine cyanurate, melamine pyrophosphate, butylene diguanamine, norbornene diguanamine, methylene diguanamine, ethylene bismelamine, trimethylene bismelamine, tetramethylene bismelamine, hexamethylene bismelamine, and 1,3-hexamethylene bismelamine. These (poly)phosphates may be used alone or in combination of two or more.

[0127] Examples of commercially available phosphorus flame retardants include ADEKA STABU (registered trademark) FP-2100J, FP-2200, and FP-2500S (manufactured by ADEKA Corporation), ADEKA STABU FP-2100JC, and Exolit (registered trademark) AP462 and Exolit OP1230 manufactured by Clariant.

[0128] 3. Intumescent flame retardant

[0129] Intumescent flame retardants are flame retardants that inhibit the combustion of materials by forming a surface intumescent layer that prevents radiant heat from the combustion source and prevents combustion gas, smoke, etc. from diffusing from the combustion product to the outside.

[0130] The intumescent flame retardant forms a surface expansion layer (expansion) when the resin composition burns, and the surface expansion layer (expansion) is a foamed char. By forming a surface expansion layer, the diffusion and heat transfer of decomposition products can be suppressed, showing excellent flame retardancy. As the intumescent flame retardant, the salts of the above-mentioned (poly)phosphoric acid and nitrogen compounds can be listed, specifically, ammonium salts and amine salts of (poly)phosphoric acid.

[0131] 4. Brominated flame retardants

[0132] Examples of the brominated flame retardant include decabromodiphenyl ether, tetrabromobisphenol A, tetrabromobisphenol S, 1,2-bis(2',3',4',5',6'-pentabromophenyl)ethane, 1,2-bis(2,4,6-tribromophenoxy)ethane, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, 2,6-dibromophenol, 2,4-dibromophenol, brominated polystyrene, ethylenebistetrabromophthalimide, hexabromocyclododecane, hexabromobenzene, pentabromobenzyl acrylate, 2,2-bis[4'(2",3"-dibromopropoxy)-3',5'-dibromophenyl]-propane, bis[3,5-dibromo-4-(2,3-dibromopropoxy)phenyl]sulfone, and tris(2,3-dibromopropyl)isocyanurate.

[0133] 5. Antimony flame retardants

[0134] Examples of the antimony-based flame retardant include antimony trioxide, antimony tetroxide, antimony pentoxide, sodium pyroantimonate, antimony trichloride, antimony trisulfide, antimony oxychloride, antimony dichloride pentachloropentane, and potassium antimonate. Antimony trioxide and antimony pentoxide are particularly preferred.

[0135] [Content of flame retardant]

[0136] In the automotive horizontal component of the present invention, the content of the flame retardant is 1 part by mass or more and 50 parts by mass or less relative to 100 parts by mass of the resin. It is preferably in the range of 1 part by mass or more and 30 parts by mass or less, and more preferably in the range of 5 parts by mass or more and 25 parts by mass. If it is 1 part by mass or more, good flame retardancy can be imparted to the automotive horizontal component, and good flame blocking properties can be obtained. On the other hand, when the flame retardant is 50 parts by mass or less, the molding processability becomes better.

[0137] [Dispersant]

[0138] 1. As a dispersant, there is no particular limitation as long as the flame retardant can be dispersed in the resin. From the perspective of compatibility with the resin, a polymer dispersant can be preferably used. Preferably, a substance that can disperse the flame retardant in the polypropylene resin can be used. As a polymer dispersant, a polymer dispersant having a functional group is preferred. From the perspective of dispersion stability, a polymer dispersant having a functional group such as a carboxyl group, a phosphoric acid group, a sulfonic acid group, a primary amino group, a secondary amino group or a tertiary amino group, a quaternary ammonium salt group, a group derived from a nitrogen-containing heterocyclic ring such as pyridine, pyrimidine, or pyrazine is preferred.

[0139] In the present invention, a polymer dispersant having a carboxyl group is preferred, and in particular, when a phosphorus-based flame retardant suitable as a flame retardant is used, a copolymer of an α-olefin and an unsaturated carboxylic acid is preferred. By using this dispersant, the dispersibility of the phosphorus-based flame retardant can be improved, and the content of the flame retardant can be reduced.

[0140] 2. Necessity of dispersant

[0141] The automotive horizontal member of the present invention does not necessarily need to contain a dispersant, and does not necessarily require a dispersant as long as flame retardancy can be ensured.

[0142] [Other reagents]

[0143] The automotive horizontal member of the present invention may contain additives such as various fibrous or non-fibrous fillers of organic or inorganic fibers, UV resistance agents, stabilizers, release agents, pigments, softeners, plasticizers, surfactants, etc., within the scope not impairing the purpose of the present invention.

[0144] [Method for producing a horizontal member for automobiles: When the resin is a thermoplastic resin]

[0145] Hereinafter, the production method when the resin is a thermoplastic resin will be described. When the resin is a thermoplastic resin, the molding material in the present invention is preferably in a flat plate shape.

[0146] 1. Cold pressing (forming) method

[0147] As a forming method for manufacturing the automotive horizontal member (molded body) of the present invention, press forming (sometimes also referred to as compression forming) is used, and press forming using cold pressing is particularly preferred. In the cold press forming method, for example, a forming material heated to a first predetermined temperature is placed in a forming mold set to a second predetermined temperature, and then pressurized and cooled.

[0148] Specifically, when the thermoplastic resin constituting the molding material is crystalline, the first predetermined temperature is equal to or higher than the melting point of the thermoplastic resin, and the second predetermined temperature is lower than the melting point. When the thermoplastic resin is amorphous, the first predetermined temperature is equal to or higher than the glass transition temperature of the thermoplastic resin, and the second predetermined temperature is lower than the glass transition temperature.

[0149] That is, the cold forming method includes at least the following steps A-1) to A-2).

[0150] Step A-1): When the thermoplastic resin is crystalline, the molding material is heated to a temperature not lower than the melting point of the thermoplastic resin and not higher than the decomposition temperature of the thermoplastic resin; when the thermoplastic resin is amorphous, the molding material is heated to a temperature not lower than the glass transition temperature and not higher than the decomposition temperature of the thermoplastic resin.

[0151] Step A-2): When the thermoplastic resin is crystalline, the molding material heated in the above step A-1) is placed in a molding die whose temperature is adjusted to below the melting point; when the thermoplastic resin is amorphous, the molding material heated in the above step A-1) is placed in a molding die whose temperature is adjusted to below the glass transition temperature, and then pressurized.

[0152] By performing these steps, the molding of the molding material can be completed.

[0153] The above-mentioned steps need to be performed in the above-mentioned order, but other steps may be included between the steps. For example, the other steps include a shaping step of pre-shaping the mold into the shape of the mold cavity of the forming mold using a shaping mold different from the forming mold used in step A-2) before step A-2).

[0154] 2. Hot pressing (forming) method

[0155] In the hot pressing (molding) method, for example, a molding material is put into a molding die, and the molding die is pressurized while the temperature is raised to a first predetermined temperature, and the molding die is cooled to a second predetermined temperature. Specifically, when the thermoplastic resin constituting the molding material is crystalline, the first predetermined temperature is above the melting point of the thermoplastic resin, and the second predetermined temperature is below the melting point. When the thermoplastic resin constituting the molding material is amorphous, the first predetermined temperature is above the glass transition temperature of the thermoplastic resin, and the second predetermined temperature is below the glass transition temperature.

[0156] The hot press forming method preferably includes at least the following steps B-1) to B-4).

[0157] B-1): A step of placing a molding material in a molding die (lower die).

[0158] B-2): A step of applying pressure while heating the molding die to a temperature not less than the melting point and not more than the thermal decomposition temperature of the thermoplastic resin when the thermoplastic resin is crystalline, or not less than the glass transition temperature and not more than the thermal decomposition temperature of the thermoplastic resin when the thermoplastic resin is amorphous (first pressing step).

[0159] B-3): A step of applying pressure in one or more stages and in a final stage so that the pressure is 1.2 to 100 times the pressure in the first pressing step (second pressing step).

[0160] B-4): A step of adjusting the mold temperature to be lower than the melting point when the thermoplastic resin is crystalline, and adjusting the mold temperature to be lower than the glass transition temperature when the thermoplastic resin is amorphous.

[0161] By performing these steps, the molding of the molding material can be completed.

[0162] 3. Common points between cold press forming and hot press forming

[0163] Process A-2) and B-3) are processes for applying pressure to the forming material to obtain a molded body of the desired shape. The forming pressure at this time is not particularly limited, but is preferably as low as possible within the range that can obtain the desired shape of the molded body. Specifically, relative to the projected area of ​​the forming mold cavity, it is preferably less than 30MPa, more preferably below 20MPa, and further preferably below 10MPa. When the forming pressure is lower than 30MPa, the equipment investment and maintenance costs of the press are not required, so it is preferred. In addition, of course, various processes can be placed between the above-mentioned processes during compression molding, for example, vacuum compression molding in which compression molding is performed while in a vacuum can also be used.

[0164] [Rebound]

[0165] Hereinafter, the springback in the case where the resin contained in the automobile horizontal member is a thermoplastic resin will be described.

[0166] 1. Springback of formed material

[0167] In order to use the forming material for cold press forming, the forming material needs to be preheated / heated to a specified temperature to soften / melt. If the thermoplastic resin becomes plastic when the forming material containing reinforcing fibers with a weight-average fiber length of more than 5mm and less than 100mm (especially the case of reinforcing fibers in a mat state with reinforcing fibers piled thereon) is preheated, the preheated forming material expands due to the rebound of the reinforcing fibers, and the volume density of the forming material changes. If the volume density changes during preheating, the forming material becomes porous, the surface area increases, and air flows into the inside of the forming material to promote the thermal decomposition of the thermoplastic resin. Here, the rebound amount refers to the value obtained by dividing the plate thickness of the forming material after preheating by the plate thickness of the forming material before preheating.

[0168] When the reinforcing fiber bundles included in the molding material become highly open (single filament-enriched) or the fiber length becomes longer, the springback amount tends to increase.

[0169] In the present invention, the springback amount of the forming material is preferably 1.2 or more and 8.0 or less. If the springback amount of the forming material is 8.0 or less, when the battery cover using the forming material burns, the battery cover can be prevented from excessively expanding and contacting the battery. On the contrary, if the springback amount is 1.2 or more, the horizontal component for automobiles using the forming material is easy to expand when heated, so that the effect of heat insulation can be obtained.

[0170] The springback amount of the molding material is preferably 3.0 or more and 8.0 or less, more preferably 4.0 or more and 7.0 or less, and still more preferably 4.0 or more and 6.0 or less.

[0171] 2. Springback of horizontal parts for automobiles

[0172] The automotive horizontal member (molded body) of the present invention preferably has a springback value of 1.2 or more and 8.0 or less, similarly to the molded material. The preferred springback value of the automotive horizontal member is 3.0 or more and 8.0 or less, the more preferred springback value of the automotive horizontal member is 4.0 or more and 7.0 or less, and the further preferred springback value is 4.0 or more and 6.0 or less. If the springback value of the automotive horizontal member is 1.2 or more, the automotive horizontal member easily expands when heated, and thus the heat insulating effect is easily obtained.

[0173] [Method for manufacturing a horizontal member for automobiles: When the resin is a thermosetting resin]

[0174] When the resin is a thermosetting resin, the automotive horizontal member of the present invention is preferably a member formed by molding a sheet molding compound (sometimes referred to as SMC) using reinforcing fibers. Since the sheet molding compound has high moldability, it can be easily molded even into complex shapes such as a battery tray or a battery top cover.

[0175] That is, the sheet molding compound can be molded to produce a fiber reinforced plastic molded product, and a battery tray with a concave and convex shape can be produced. The flowability and shapeability of the sheet molding compound are higher than those of continuous fibers, and ribs and protrusions can be easily produced.

[0176] As a sheet molding compound (SMC) used for a fiber-reinforced plastic molded product, a sheet molding compound manufactured by Teijin Automotive Technologies (sometimes referred to as TAT) can be used. In general, when a sheet molding compound is molded to produce a fiber-reinforced plastic molded product, compression molding is used.

[0177] [Horizontal parts for automobiles]

[0178] 1. Summary

[0179] The automotive horizontal component of the present invention refers to a horizontal component that is installed horizontally when it becomes an automotive component. The horizontal component does not necessarily need to be horizontal as a whole, and a part or most of it can be horizontal. Examples include a battery cover, a battery bottom protection cover, a roof, a hood, and a cover portion of a rear door. In order to improve the flame retardancy of the automotive horizontal component, it is necessary to prevent it from sagging during combustion.

[0180] 2. Battery tray, battery cover, battery bottom protection cover

[0181] The automotive horizontal member of the present invention is preferably a component of a battery box. The component of the battery box is preferably any one of a battery tray, a battery cover, and a battery bottom protection cover.

[0182] 2.1 Battery tray and battery cover

[0183] Figure 2 FIG. 1 is a cross-sectional view showing an example of a battery box. Figure 2 As shown, the battery 303 is housed in a battery box including a battery tray 305 and a battery cover 302. In addition, the components of the battery box are preferably for vehicles.

[0184] 2.2 Battery bottom protection cover 2.2.1

[0186] The automobile horizontal member in the present invention may also be a battery bottom protection cover. Figure 2 More specifically, it is preferred that at least one portion of the battery bottom protection cover 401 is fastened to the battery tray 305 by a fastening rod 402 , and that the fastening insertion hole 403 is integrally formed in the battery tray 305 .

[0187] 2.2.2 Insertion hole

[0188] Preferably, the battery tray 305 includes an insertion platform 404 protruding toward the battery bottom protection cover 401 , and the insertion hole 403 is disposed inside the insertion platform 404 .

[0189] 2.2.3 Buffer materials

[0190] It is preferable to arrange the cushioning material 405 between the battery tray 305 and the battery bottom protection cover 401. In addition, it is more preferable that the cushioning material 405 is a honeycomb structure. By providing such a cushioning material 405, the impact resistance against the impact from the lower part of the vehicle is improved.

[0191] 2.2.4 Rectifier

[0192] The battery bottom protection cover is preferably integrally formed with a rectifying plate, and the rectifying plate can be provided on the lower side of the battery bottom protection cover. By providing the rectifying plate, air resistance is reduced and the running stability of the vehicle is improved.

[0193] 2.2.5 Electromagnetic wave shielding layer

[0194] The electromagnetic wave shielding layer is preferably installed on the upper surface of the battery cover. In addition, the electromagnetic wave shielding layer can also be set between the battery bottom protective cover and the battery tray. In this case, the electromagnetic wave shielding layer is preferably set on the upper surface of the battery bottom protective cover, and the buffer material is more preferably arranged on the upper side of the electromagnetic wave shielding layer.

[0195] 3. Thickness of horizontal parts for automobiles

[0196] The thickness of the automobile horizontal member is preferably 1 mm or more, more preferably 3 mm or more, and even more preferably 5 mm or more.

[0197] [Tensile test before and after fire resistance]

[0198] The automotive horizontal member of the present invention satisfies the following (a).

[0199] (a): The tensile strength retention rate represented by formula (1) is greater than 0.03%. The preferred tensile strength retention rate is 0.05% or more, more preferably 0.06% or more, and further preferably 0.1% or more. In addition, the range of the tensile strength retention rate is preferably 0.04% or more and 50% or less, more preferably 0.05% or more and 40% or less, further preferably 0.06% or more and 30% or less, and further preferably 1% or more and 25% or less. If the tensile strength retention rate is greater than 0.03%, the shape of the horizontal component for automobiles can be maintained after combustion without resin dripping.

[0200] Tensile strength retention rate (%) = (tensile strength B after combustion ÷ tensile strength A before combustion) × 100 Formula (1)

[0201] 1. When the horizontal component for automobile is a battery cover

[0202] In the case where the horizontal component for automobiles of the present invention is a battery cover 302, fire resistance against flames from the batteries 303 present inside the battery box is required. Furthermore, in the event of an accident, if the leaked gasoline burns, the battery cover 302 may be exposed to a flame of 700 to 800°C. Therefore, compared with conventional battery covers, fire resistance under more stringent conditions is required. Therefore, fire resistance becomes very important for the interior of the battery box. At this time, if the tensile strength retention rate exceeds 0.03%, the battery cover will not drip resin after burning and contact the battery itself. In the case of a battery cover, the tensile strength retention rate is preferably not less than 0.05%, and more preferably not less than 0.07%.

[0203] The stress when the battery cover after combustion is pressed from the non-flame contact side (upper side) with a push-pull dynamometer is preferably 100 N or more, more preferably 150 N or more, and even more preferably 200 N or more.

[0204] 2. When the horizontal component for automobile is a battery tray

[0205] When the horizontal component for automobile of the present invention is a battery tray, the battery box needs to meet the fire resistance requirements against flames from outside the vehicle, so the fire resistance performance becomes important for the exterior of the battery box. In the case of a battery tray, the tensile strength retention rate is preferably 0.04% or more, more preferably 0.06% or more, and further preferably 0.1% or more.

[0206] [Collection of test pieces: residual tensile strength]

[0207] The method for measuring the tensile strength retention rate is described below. Ten test pieces with a width of 25 mm and a length of 150 mm are cut out from the horizontal member for automobiles. The tensile strength of five of the cut test pieces is measured, and the measurement results are referred to as the tensile strength A before the combustion test. The remaining five test pieces are subjected to a combustion test, and the tensile strength of the five test pieces after the combustion test is measured, and the measurement results are referred to as the tensile strength B after the combustion test.

[0208] [Work done]

[0209] The automotive horizontal member of the present invention satisfies the following (b).

[0210] (b): For the test piece with a width of 25 mm after the combustion test, the work per unit area weight in the tensile test is 0.5×10 -3 [(N·mm) / (g / m 2 )] and above and 100×10 -3 [(N·mm) / (g / m 2 )]the following.

[0211] Here, the work amount is a value obtained by integrating the tensile force in the tensile test with the strain amount. The work amount per unit area weight in the tensile test is a value obtained by integrating the load per unit area weight in the tensile test with the displacement value of the strain.

[0212] For example, in Figure 3 In the load-strain [mm] curve obtained by converting the displacement ratio [unit: %] of the strain on the horizontal axis of the load-strain [%] curve in the tensile test shown in the figure into the displacement amount (unit: mm), the amount of work done in the tensile test can be calculated by integrating the load per unit area weight with the strain amount [mm].

[0213] If the work amount is above the lower limit, the horizontal component for automobiles will not droop during combustion and the resin will droop. On the contrary, if it is below the upper limit, a large pressure is not required during press molding, so the horizontal component for automobiles can be easily molded. For the test piece with a width of 25 mm after the combustion test, the work amount per unit area weight in the tensile test is preferably 0.5×10 -3 [(N·mm) / (g / m 2 )] and less than 100×10 -3 [(N·mm) / (g / m 2 )], more preferably 0.5×10 -3 [(N·mm) / (g / m 2 )] and less than 50×10 -3 [(N·mm) / (g / m 2 )], and more preferably 1.0×10 -3 [(N·mm) / (g / m 2 )] and less than 30×10 -3 [(N·mm) / (g / m 2 )], and more preferably 1.5×10 -3 [(N·mm) / (g / m 2 )] and less than 20×10 -3 [(N·mm) / (g / m 2 )], and the most preferred value is 1.5×10 -3 [(N·mm) / (g / m 2 )] and less than 10×10 -3 [(N·mm) / (g / m 2 )].

[0214] [Average rate of change of load]

[0215] 1. The automotive horizontal member of the present invention preferably satisfies the following (c).

[0216] (c): In the tensile test of the test piece with a width of 25 mm after the combustion test, the load [N / (g / m 2 The average change rate of )] is 0.1×10 -3 [N / (g / m 2 )] and less than 100×10 -3 [N / (g / m 2 )] range. The load [N / (g / m 2 The more preferred average change rate of )] is 0.5×10 -3 [N / (g / m 2 )] and above and 9.0×10-3 [N / (g / m 2 )], and the more preferred average change rate is 1.5×10 -3 [N / (g / m 2 )] and above and 8.0×10 -3 The following range, the more preferred average change rate is 1.5×10 -3 Above and 7.0×10 -3 the following.

[0217] Strain 0.1% to 0.2% load [N / (g / m 2 The average change rate of )] is 0.1×10 -3 [N / (g / m 2 )] means that a certain degree of stress is required to deform the fiber. That is, if the load [N / (g / m 2 The average change rate of )] is 0.1×10 -3 [N / (g / m 2 )] or more, the fibers will not sag when the horizontal parts for automobiles burn, so it is preferred. If the strain is 0.1% to 0.2% load [N / (g / m 2 )] has an average change rate of less than 100×10 -3 [N / (g / m 2 )], it means that in the initial stage of applying the load, a large load is not required and the material can be easily formed. Here, the load with a strain of 0.1% to 0.2% [N / (g / m 2 )] refers to the average rate of change, for example Figure 3 Load [N / (g / m 2 )] is the slope of the arrow indicated by symbol 502 in the strain [%] curve.

[0218] 2. The automotive horizontal member of the present invention preferably satisfies the following (d).

[0219] (d): In the tensile test of the test piece with a width of 25 mm after the combustion test, the load [N / (g / m 2 The average change rate of )] is -1.0×10 -3 [N / (g / m 2 )] and above -0.01×10 -3 [N / (g / m 2 Here, the load [N / (g / m 2 )] refers to the average rate of change, for example Figure 3 Load [N / (g / m 2)] is the slope of the arrow indicated by symbol 503 in the strain [%] curve.

[0220] Load [N / (g / m 2 )] has an average rate of change of negative value. If it is within this range, it means that no large load is required except for the initial load during forming, and the material can be easily formed.

[0221] [Strain range when the load per unit area weight reaches the maximum value]

[0222] The automotive horizontal member of the present invention preferably satisfies the following (e).

[0223] (e) In a tensile test of a test piece after a 25 mm wide combustion test, the maximum load value is within a range of strain greater than 0% and less than 2%. Preferably, the maximum load value is within a range of strain greater than 0% and less than 1%, and more preferably, the maximum load value is within a range of strain greater than 0% and less than 0.5%.

[0224] The maximum load value in the range of strain greater than 0% and less than 2% means the load [N / (g / m 2 The load [N / (g / m 2 The )]-strain [%] curve preferably has a peak value of the maximum load in the range of strain greater than 0% and less than 1%, and more preferably has a peak value of the maximum load in the range of strain greater than 0% and less than 0.5%.

[0225] When the forming material is press-formed by the upper and lower forming dies, stress can be applied to the forming material immediately after the upper and lower forming dies are closed and clamped. By designing the maximum load value in the above range (the initial stage of strain increase), even the forming material (horizontal component for automobile) with the same amount of work can be formed more easily.

[0226] [Maximum value of load per unit area weight]

[0227] The automotive horizontal member of the present invention preferably satisfies the following (f).

[0228] (f): In the tensile test of the test piece with a width of 25 mm after the combustion test, the maximum load per unit area weight was 1.1×10 -3 [N / (g / m 2 The maximum load per unit area weight is more preferably 1.15×10 -3 [N / (g / m 2 )] or more, more preferably 1.5×10-3 [N / (g / m 2 )] or more, and more preferably 2.0×10 -3 [N / (g / m 2 )] or more, and most preferably 3.0×10 -3 [N / (g / m 2 )]above.

[0229] The maximum load per unit area is 1.1×10 -3 [N / (g / m 2 )] or more, the fibers will not droop when the horizontal parts for automobiles burn, so it is preferred. In addition, by setting the maximum load per unit area weight to 1.1×10 -3 [N / (g / m 2 )] or more, so that if a large load is applied at a specific forming stage, it can be easily formed with a smaller load in other stages, and there is no need to continue to apply a large load all the time before the forming is completed.

[0230] On the other hand, the maximum load per unit area weight is more preferably 10×10 -3 [N / (g / m 2 )] or less. If the maximum load per unit area weight is 10×10 -3 [N / (g / m 2 )] or less, no large load is required when forming horizontal parts for automobiles, and they can be easily formed.

[0231] [Air volume blown to the cut reinforcement fibers]

[0232] The method for manufacturing a horizontal member for an automobile in which the above-mentioned [amount of work], [average rate of change of load], [strain range when the load per unit weight is maximum], and [maximum value of the load per unit weight] are values ​​that satisfy the above-mentioned (b) to (f) is not particularly limited, but after cutting the reinforcing fibers, compressed air is supplied using a compressor just below the cutting device, and by adjusting the air volume of the compressed air, the values ​​of [amount of work], [average rate of change of the load-strain curve], and [maximum value of the load per unit weight] can be adjusted to be within the target range.

[0233] Example

[0234] [Production of molding materials]

[0235] [Material]

[0236] 1. Reinforced fiber

[0237] The following two types of reinforcing fibers were prepared.

[0238] (1) Glass fiber multi-end roving

[0239] (オーウェンスコーニング: OC Paneluxe (registered trademark) 2400Tex)

[0240] (2) Glass fiber single-end roving

[0241] (オーウェンスコーニング:SE2348 roving 2000Tex)

[0242] 2. Resin

[0243] Polypropylene resin: Novatech (registered trademark) PP BC03C produced by Polypro Co., Ltd. of Japan

[0244] 3. Flame retardant

[0245] ADEKA Corporation ADEKA STARTER (registered trademark) FP2100-J C

[0246] [Example 1]

[0247] As the thermoplastic resin, a thermoplastic resin prepared by adding 11 parts by mass of a flame retardant (Adica Stab FP2100-JC) to a polypropylene resin (Novatec PPBC03C manufactured by Nippon Polypro Co., Ltd.) was prepared.

[0248] A permeable support having a suction mechanism at the bottom and continuously moving in one direction is provided below the polypropylene resin supply machine. While the permeable support is moved at 2 m / min, the polypropylene resin is sprinkled on the permeable support from the supply machine to fix the polypropylene resin on the permeable support, thereby preparing a polypropylene resin assembly.

[0249] A rotary cutter was set above the air permeable support, and the single-end roving of (2) was cut into a fixed length of 20 mm using the rotary cutter. At this time, compressed air was supplied directly below the rotary cutter, and the negative pressure generated in the air flow was used to pull the glass fiber away from the roller. The air volume of the compressed air was 170 L / min.

[0250] The cut glass fibers are spread on a polypropylene resin assembly prefabricated on an air-permeable support and fixed to obtain a glass fiber assembly. The amount of glass fibers supplied is set so that the volume ratio of the glass fibers to the molding material reaches 40% and the average thickness of the molding material reaches 2.0 mm.

[0251] The composite material was cut into 20 mm lengths using a rotary cutter to produce a composite material of polypropylene resin aggregate and glass fiber aggregate with a width of 600 mm and a length of 3 m. The composite material was produced at a speed of 2 m / min.

[0252] The prepared composite composition including the glass fiber assembly and the polypropylene resin assembly is heated in a continuous impregnation device to impregnate the polypropylene resin into the glass fiber and then cooled to obtain a molding material.

[0253] The formed material is cold pressed to form a battery cover and a battery tray, which are horizontal parts for automobiles.

[0254] [Example 2]

[0255] The same method as in Example 1 was carried out except that the air volume during the feeding of the compressed air was set to 50 L / min.

[0256] [Example 3]

[0257] The same method as in Example 1 was carried out except that the air volume during the feeding of the compressed air was set to 230 L / min.

[0258] [Example 4]

[0259] The same method as in Example 1 was carried out except that the air volume during the feeding of the compressed air was set to 300 L / min.

[0260] [Example 5]

[0261] As the thermoplastic resin, a thermoplastic resin prepared by adding 11 parts by mass of a flame retardant (Adica Stab FP2100-JC) to a polypropylene resin (Novatec PPBC03C manufactured by Nippon Polypro Co., Ltd.) was prepared.

[0262] A permeable support having a suction mechanism at the bottom and continuously moving in one direction is provided below the polypropylene resin supply machine. While the permeable support is moved at 2 m / min, the polypropylene resin is sprinkled on the permeable support from the supply machine to fix the polypropylene resin on the permeable support, thereby preparing a polypropylene resin assembly.

[0263] The multi-end roving of (1) was slit and split into fibers with a fiber width of 1 mm using a slitting device (cutting by pressing with a rubber roller).

[0264] The multi-end roving (1) and the single-end roving (2) after slitting were supplied to a rotary cutter arranged above the air-permeable support in a volume ratio of 1:1, and cut into a fixed length of 20 mm using the rotary cutter. At this time, compressed air was supplied directly below the rotary cutter, and the negative pressure generated in the air flow was used to pull the glass fiber away from the roller. The air volume of the compressed air was 170 L / min.

[0265] The cut glass fibers were spread on a polypropylene resin assembly prefabricated on an air-permeable support and fixed to obtain a glass fiber assembly. The amount of glass fibers supplied was set so that the volume ratio of the glass fibers relative to the forming material was 38% and the average thickness of the forming material was 2.0 mm.

[0266] The composite material was cut into 20 mm lengths using a rotary cutter to produce a composite material of polypropylene resin aggregate and glass fiber aggregate with a width of 600 mm and a length of 3 m. The composite material was produced at a speed of 2 m / min.

[0267] The prepared composite composition including the glass fiber assembly and the polypropylene resin assembly is heated in a continuous impregnation device to impregnate the polypropylene resin into the glass fiber and then cooled to obtain a molding material.

[0268] The produced molded material is cold pressed to form a battery cover and a battery tray as horizontal parts for automobiles.

[0269] [Comparative Example 1]

[0270] The same method as in Example 1 was carried out except that the air volume during the feeding of the compressed air was set to 0 L / min.

[0271] [Evaluation method]

[0272] 1. Tensile strength retention rate

[0273] 1.1 Ten test pieces with a width of 25 mm and a length of 150 mm were cut out from a horizontal member for an automobile.

[0274] 1.2 Five of the obtained test pieces were subjected to a tensile test at a load speed of 1 mm / min. in accordance with ASTM D3039 (2019) to measure the tensile strength. The average value of the five tensile strengths was taken as the tensile strength A before the combustion test.

[0275] 1.3 Combustion test

[0276] Carry out combustion tests on the remaining 5 test pieces. Figure 1 As shown, aluminum plates 105 are used to clamp both ends of the test piece 101 at an interval of 40 mm in the longitudinal direction, and the flame 103 of a 1000°C gas burner is used to directly burn the resin in the 40 mm area (combustion area 102) in the longitudinal direction of the center of the test piece 101. The burner port 104 is set 60 mm away from the test piece 101 and the combustion is performed. Depending on the test piece, the temperature and time until the resin in the combustion area 102 is completely burned may vary. Therefore, the center of the test piece 101 is on the opposite side of the gas burner flame 103 ( Figure 1The back surface temperature was measured using a non-contact thermometer (Advanced Device AD-5611A, Co., Ltd.) at a distance of 30 cm from the back surface, and the back surface temperature was confirmed to be 350 degrees or more, and then the test piece 101 was burned for 5 minutes. It should be noted that after the flame 103 of the gas burner was extinguished after burning for 5 minutes, if the flame of the test piece 101 did not disappear, it was waited until it was completely digested without actively extinguishing the fire.

[0277] In addition, depending on the type of resin, even under the above conditions, the resin in the combustion region 102 may not be completely burned out. In this case, additional heating may be performed.

[0278] 1.4 The five test pieces after the combustion test were subjected to a tensile test at a load speed of 2 mm / min. in accordance with ASTM D3039 (2019) to measure the tensile strength. The average value of the five tensile strengths was taken as the tensile strength B after the combustion test.

[0279] 1.5 Based on the tensile strength A before the combustion test and the tensile strength B after the combustion test, the tensile strength retention rate was calculated using formula (1).

[0280] 2. Average rate of change of work done and initial load after loading

[0281] 2.1 Six test pieces with a width of 25 mm and a length of 150 mm were cut out from the horizontal member for automobiles.

[0282] 2.2 The test piece was burned under the same conditions as in the above-mentioned "1.3 Burning Test" of "1. Tensile Strength Retention Rate".

[0283] 2.3 According to the A method (strip method) of 8.14.1a) of JIS L 1096:2010, for each of the 6 test pieces after combustion, a constant-speed elongation type tensile testing machine was used with a clamping distance of 100 mm, and the test pieces were stretched at a tensile speed of 1 mm / min. The load in the tensile test was integrated with the strain amount [mm], and the amount of work was calculated respectively, and the average value of the 6 test pieces was obtained. In addition, the average rate of change from 0.1% to 0.2% of the strain was calculated by dividing the difference obtained by subtracting the load at a strain of 0.1% from the load at a strain of 0.2% by 0.001, and the average value of the 6 test pieces was calculated. Furthermore, the average rate of change from 0.5% to 3.0% of the strain was calculated by subtracting the difference obtained by subtracting the load at a strain of 0.5% from the load at a strain of 3.0% by 0.025, and the average value of the 6 test pieces was obtained.

[0284] 3. Rebound

[0285] The molding material was cut into 100 mm × 100 mm and two pieces were overlapped. A thermocouple was inserted in the center of the bonding surface, and then placed in a preheating furnace heated to 280°C for the upper and lower heaters, and heated until the thermocouple temperature reached 275°C. When the thermocouple temperature reached 210°C, it was taken out of the furnace, cooled and solidified, and the wall thickness after preheating was measured. The ratio of the wall thickness before preheating and the wall thickness after preheating expressed by the following formula was calculated as the springback amount.

[0286] Springback amount = wall thickness after preheating (mm) / wall thickness before preheating (mm)

[0287] 4. Formability

[0288] The flat sheet of forming material was cut into 205 mm long x 95 mm wide, and two sheets were stacked in a thickness of 2 mm. After drying in a hot air dryer at 120°C for 4 hours, the temperature was raised to 240°C using an infrared heater. Next, a flat sheet-shaped forming mold was prepared and set to 60°C. The cut and heated forming material was placed directly in the opening in a stacked state, and the forming mold was closed by a mechanical servo press (ZENFormer (registered trademark) MPS4200 manufactured by Discharge Precision Machining Research Institute Co., Ltd.). The thickness of the obtained formed body was observed, and the formability was evaluated based on the degree of reduction compared to the thickness of the forming material.

[0289] Perfect: Plate thickness reduction rate is more than 30%

[0290] Excellent: Plate thickness reduction rate is 20% or more and less than 30%

[0291] Good: Plate thickness reduction rate is 10% or more and less than 20%

[0292] Good: Plate thickness reduction rate is 5% or more and less than 10%

[0293] Poor: Plate thickness reduction rate is less than 5%

[0294] 5. Thermal insulation

[0295] Ten test pieces of 300 mm in width and 300 mm in length were cut from the horizontal parts for automobiles. The test pieces were placed on a frame test table capable of holding 300 mm square objects, and the center of the test pieces was directly burned using the flame of a 1000°C burner. The test pieces were 60 mm away from the burner port, and burned for 3 minutes. A non-contact thermometer (Advanced Device AD-5611A, Co., Ltd.) was used to measure the back temperature of the center of the test piece on the side opposite to the burner flame at a distance of 30 cm from the test piece.

[0296] Excellent: The back surface temperature during measurement was 200°C or less within 3 minutes from the start of combustion.

[0297] Very good: From the start of combustion, the back surface temperature exceeds 200°C within more than 70 seconds and less than 3 minutes.

[0298] Good: The back surface temperature exceeds 200°C within more than 10 seconds and less than 70 seconds from the start of combustion.

[0299] Failure: Within 10 seconds after the start of combustion, the back surface temperature exceeds 200°C.

[0300] Table 2 shows the evaluation results.

[0301] [Table 1]

[0302]

[0303] [Table 2]

[0304]

Claims

1. A horizontal component for an automobile, characterized in that: Contains: reinforcing fibers with a weight-average fiber length of 5 mm or more and 100 mm or less, resin, and flame retardant, The flame retardant is contained in an amount of 1 part by mass or more and 50 parts by mass or less relative to 100 parts by mass of the resin. The horizontal component for automobiles satisfies the following (a) to (b): (a): The tensile strength retention rate represented by formula (1) is greater than 0.03%, Tensile strength retention rate (%) = (tensile strength B after combustion ÷ tensile strength A before combustion) × 100 Formula (1) (b): For the test piece with a width of 25 mm after the combustion test, the amount of work per unit area weight in the tensile test was 0.5×10 -3 [(N·mm) / (g / m 2 )] and above and 100×10 -3 [(N·mm) / (g / m 2 )] and the maximum load per unit area is 1.1×10 -3 [N / (g / m 2 )]above.

2. The horizontal member for an automobile according to claim 1, wherein: In the tensile test of the test piece having a width of 25 mm after the combustion test, the maximum load per unit area weight was obtained in the range of strain greater than 0% and less than 2%.

3. The automotive horizontal member according to claim 1 or 2, wherein: The horizontal component for automobiles satisfies the following (c), (c): In the tensile test of the test piece with a width of 25 mm after the combustion test, the load [N / (g / m 2 The average change rate of )] is 0.1×10 -3 [N / (g / m 2 )] and less than 100×10 -3 [N / (g / m 2 )].

4. The horizontal member for an automobile according to claim 3, wherein: The horizontal component for automobiles satisfies the following (d), (d): In the tensile test of the test piece with a width of 25 mm after the combustion test, the load [N / (g / m 2 The average change rate of )] is -1.0×10 -3 [N / (g / m 2 )] and above -0.01×10 -3 [N / (g / m 2 )] below the range.

5. The automotive horizontal member according to any one of claims 1 to 4, wherein: The resin is a thermoplastic resin.

6. The automotive horizontal member according to any one of claims 1 to 5, wherein: The resin is polypropylene resin.

7. The automotive horizontal member according to any one of claims 1 to 6, wherein: The reinforcing fiber is glass fiber.

8. The automotive horizontal member according to any one of claims 1 to 7, wherein: The automobile horizontal component is a battery cover or a battery bottom protection cover.

9. The automotive horizontal member according to any one of claims 1 to 8, wherein: The resin is a thermoplastic resin, and the automotive horizontal member has a rebound coefficient of 1.2 or more and 8.0 or less.

10. A method for manufacturing a horizontal component for an automobile, characterized in that: The horizontal component for automobiles according to any one of claims 1 to 9 is manufactured by cold pressing a molding material containing reinforcing fibers and a thermoplastic resin. The molding material has a springback factor of 1.2 or more and 8.0 or less.

11. The method for manufacturing a horizontal member for an automobile according to claim 10, wherein: The reinforcing fibers are glass fibers, and the molding material is prepared by mixing glass fibers GFs of single-end rovings and glass fibers GFm of multi-end rovings at a volume ratio of GFm:GFs of 90:10 to 50:50.

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