Molded composite articles and methods for producing them

Abstract

This disclosure relates to molded transport components or structural components, including composite materials and surface treatment agents, and methods for producing them. The composite materials include polymer resins and fibrous reinforcing materials. The surface treatment agents include microporous sheets bonded to the composite materials, comprising a polyolefin polymer matrix, a finely pulverized particulate inorganic filler distributed throughout the matrix, and an interconnected pore network communicating throughout the microporous sheet. Methods for producing molded transport components are also provided.

Description

Technical Field

[0001] The present disclosure is directed to formed composite articles, particularly transportation vehicle components, comprising a composite material and a surface treatment agent comprising a microporous sheet.

Background Art

[0002] Composite materials can provide desired mechanical properties at a lower weight than metals or other materials. Their use has become widespread in many industries. Reinforced composite materials provide particularly strong substrates. Composite materials can be formed in numerous ways, including molding. Because composite materials combine two or more constituent materials, the surface of the composite material may be rough and may require additional treatment before the material can be used, painted, etc. Improvement of the surface smoothness on formed composites is desired.

Summary of the Invention

[0003] The present disclosure is directed to formed transportation vehicle components or structural components comprising a composite material and a surface treatment agent, and methods of making them. The composite material includes a polymer resin and a fibrous reinforcing material. The fibrous material can include fibers having a length of 0.5 to 12 mm, or 0.5 to 6 mm, or 0.5 to 3 mm, or 3 to 6 mm, or 3 to 12 mm, distributed throughout the polymer resin. Additionally or alternatively, the fibers can have a tensile strength of 300 to 7000 MPa, or 300 to 5000 MPa, or 300 to 2000 MPa, or 500 to 7000 MPa, or 500 to 5000 MPa, or 500 to 2000 MPa, or 1000 to 7000 MPa, or 1000 to 5000 MPa, or 1000 to 2000 MPa. The surface treatment agent is a microporous sheet adhered to the composite material, the microporous sheet adhered to the composite material including a polyolefin-based polymer matrix, micronized particulate inorganic fillers distributed throughout the matrix, and an interconnected pore network communicating throughout the microporous sheet.

[0004] This disclosure further relates to a method for producing a molded transport component, wherein a microporous sheet is stretched over at least a portion of the inside of a mold, a composite material is added on top of the microporous sheet of the mold, the mold is closed, and the composite material is cured. [Modes for carrying out the invention]

[0005] This disclosure relates to molded articles, particularly those that are components of transportation systems or structures, comprising composite materials and surface treatment agents, wherein the surface treatment agent includes a microporous sheet bonded to the composite material.

[0006] According to this disclosure, any composite material can be used. Particularly preferred are reinforced composite materials, such as composite materials comprising a polymer resin, often acting as a matrix, and reinforcing fillers. The composite material may include a suitable inorganic and / or organic resin or matrix, such as a natural and / or synthetic material such as a resinous component, and / or fillers, concentration modifiers, and / or other fillers or performance modifiers, such as reinforcing or strengthening components.

[0007] The composite materials according to this disclosure may comprise any suitable crystalline, semicrystalline, or amorphous, thermoplastic, and / or thermosetting resins, compounded compositions, and / or curing agents. Examples of suitable resins and / or matrix components include polyurethane, amines, amides, acrylonitrile-butadiene-styrene (ABS), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polycarbonate (PC), polyamide (e.g., nylon), high-impact polystyrene (HIPS), polypropylene (PP), polyether ether ketone (PEEK), sheet molding compounds, bulk molding compounds, thermoplastic or thermosetting molding compounds, epoxy resins, phenolic resins, melamine resins, urea resins, polyether ketone ketone (PEKK), polyaryl ether ketone (PAEK), polymer matrix composites (PMC), metal matrix composites (MMC), ceramic matrix composites (CMC), polyethylene (PE), polyoxymethylene (POM), polystyrene (PS), polyester (e.g., polyethylene terephthalate (PET) and polyethylene naphthium). Examples include talates (PEN), polyimides, polyacetals, polyphenylene oxides, polyphenylene sulfides, polyethersulfones, cyclic polyolefins (such as homopolymers of norbornene monomers (addition polymers and ring-opening polymers), copolymers of norbornene monomers and olefin monomers (such as addition polymers and ring-opening polymers, and derivatives thereof), vinyl polymers (e.g., acrylic resins such as polymethacrylate (PMMA)), polystyrene, polyvinyl chloride, vinylidene polymers (e.g., polyvinylidene chloride), cellulose resins (e.g., triacetylcellulose (TAC)), maleimide resins, halogenated resins (e.g., fluoropolymers or chlorinated compounds), silicones, inorganic resins, organic / inorganic hybrids, combinations, and / or derivatives thereof.

[0008] Composite materials may include fillers. For example, a composite material may include a polymer resin acting as a matrix in a continuous phase and fillers, such as reinforcing fibers, dispersed in the resin matrix and distributed throughout the resin matrix. As used herein, “filler” or “filler material” refers to a material that can be used to fill or increase the volume of a composition. If necessary, fillers may impart or modify properties such as color, opacity, thermal stability, and / or conductivity, electrical conductivity, and / or insulation, tensile strength, modulus of elasticity, impact strength, shatter resistance, and flame retardancy. Any suitable filler, including inorganic or organic materials, may be used. Fillers may be surface-treated or otherwise modified by any machining or chemical process. Fillers may include natural materials, modified natural materials that have been mined and sized, compounded, separated, and / or treated, and / or synthetic materials, and may include inorganic and / or organic components, and combinations thereof. The surface roughness (Ra) of the composite material alone (i.e., the composite material formed and cured without the microporous sheets of this disclosure) may vary depending on the type of materials combined in the composite and the manner in which the composite material is formed and cured. The Ra of the composite material alone may be 3.0 microns or greater than 3.0 microns, such as 3.5, 4.0, 4.5, 5.0, 5.5 microns or greater than 3.5, 4.0, 4.5, 5.0, 5.5 microns. The Ra values ​​reported herein were determined as described in the Examples section.

[0009] The filler may have any size, particle shape, or geometric shape. For example, the filler may include nano, submicron, and / or micron particles or compounded materials. The filler may include separate particles or components, or any other suitable structures such as shredded or continuous strands, webs, or woven mats. The filler may have a regular or irregular shape. The filler may be spherical, elliptical, cubic, plate-like or planar, needle-like (elongated or fibrous), rod-like, disc-like, prismatic, flake-like, irregular, rock-like, aggregates thereof, and any combination thereof. For example, the filler may include planar materials such as phyllosilicate materials containing sheets of silicate. Non-limiting examples of phyllosilicate fillers include mica, chlorite, serpentine, talc, and clays such as kaolin clay and smectite clay. The filler may be amorphous. The filler may be hollow, such as glass or plastic microspheres, and / or gas-filled, such as expandable plastics that expand upon exposure to heat. The filler may be treated or otherwise modified by corona discharge, mechanical or chemical treatment, or by other means, such as with silane or other coupling agents, or otherwise functionalized to modify bonding, dispersion, or reaction with the composite resin matrix.

[0010] Non-limiting examples of reinforcing fillers include fibrous reinforcing materials (such as short glass fibers) and non-fibrous fillers (such as graphite, kaolin, talc, silica, mica, or wollastonite). Other non-limiting examples of reinforcing fillers include shredded fibers, continuous fibers, filaments, hemp waste, bundles, and combinations thereof. Additionally, reinforcing fibers can be oriented unidirectionally (i.e., aligned in one direction), multidirectionally (i.e., aligned in different directions relative to each other, such as 45 degrees, 90 degrees, etc.), or randomly, and reinforcing fibers can form a variety of structures, including, but not limited to, sheets, layers (ply), fabrics, cloths, unwoven, woven, knitted, sewn, wound, and braided structures, as well as swirl mats, bales, felt mats, and shredded mat structures. Woven structures may include multiple woven hemp wastes, each consisting of multiple filaments containing thousands of filaments.

[0011] Non-limiting examples of fillers include glass, glass fibers, glass cloth fibers, glass bales, carbon fibers, carbon fiber cloth, carbon fiber bales, graphite, aramid, polyamide, high modulus polyethylene (PE), polyester, poly-p-phenylene-benzoxazole (PBO), boron, quartz, basalt, ceramics, organic synthetic materials (such as KEVLAR), ceramics, metals (including copper), thermoplastic polymer resins, thermoplastic polymer fibers, thermoplastic polymer bales, natural cellulose fibers such as flax, hemp, jute, and cotton, and combinations thereof. Glass fibers may include electrolytic or E-glass fibers, A-glass fibers, C-glass fibers, E-CR-glass fibers, D-glass fibers, R-glass fibers, S-glass fibers, or combinations thereof. Carbon fibers may include carbon fibers formed from polyacrylonitrile (PAN) polymer, polyethylene, pitch-based carbon fibers, and combinations thereof. When producing high-strength composite materials, reinforcing fibers can have tensile strengths exceeding 3500 MPa.

[0012] In certain examples, the fibrous reinforcing material is distributed throughout the polymer resin, containing fibers having a length of at least 0.5 mm, or at least 3 mm, and up to 12 mm, or up to 6 mm, or up to 3 mm. For example, the fibers may be shorter, having a length of 0.5–12 mm, or 0.5–6 mm, or 0.5–3 mm, or longer, having a length of 3–6 mm or 3–12 mm.

[0013] Depending on the fiber composition, they typically have a width of at least 5 microns or at least 6 microns, and up to 20 microns, or up to 10 microns, or up to 7 microns. For example, fibers may have a width of 5–20 microns, or 5–10 microns, or 5–7 microns, or 6–20 microns, or 6–10 microns, or 6–7 microns.

[0014] Additionally or alternatively, the fibers may have a tensile strength of at least 300 MPa, or at least 500 MPa, or at least 1000 MPa, and up to 7000 MPa, or up to 5000 MPa, or up to 2000 MPa. For example, the fibers may have a tensile strength of 300-7000 MPa, or 300-5000 MPa, or 300-2000 MPa, or 500-7000 MPa, or 500-5000 MPa, or 500-2000 MPa, or 1000-7000 MPa, or 1000-5000 MPa, or 1000-2000 MPa. The fibrous reinforcing material may include woven sheets, nonwoven sheets, or sewn fabric sheets that can be impregnated with a polymer resin of the composite material.

[0015] The tensile strength of a fiber can be determined using ASTM D4018-17 or ASTM D2343-17 (for glass and carbon fibers), depending on the fiber's composition. Often, a single value or range of tensile strength for a fiber is reported by the supplier and relied upon.

[0016] The composite material may further include colorants, plasticizers, antioxidants, biocides, UV light absorbers and stabilizers or accelerators (thermal and electrical stabilizers or conductivity enhancers), flame retardants, hindered amine light stabilizers, defoamers, fungicides, dispersing aids, flow control agents, surfactants, wetting agents, release agents, or combinations thereof. As used herein, “colorant” means any substance that imparts color and / or other opacity and / or other visual effects to the composition.

[0017] The surface treatment agents according to this disclosure are in the form of microporous sheets. A material is “porous” (including “microporous”) if it contains spaces, holes, or pores through which a liquid or gas can pass. As microporous sheets, the surface treatment agents of the present invention differ from surface treatment agents composed of curable thermosetting or thermoplastic films, which are not porous and may release volatile organic compounds (VOCs) when cured. In addition, microporous sheets can often “bond” with composite materials during molding due to the penetration of polymer resins into the pores of the microporous sheet.

[0018] The calculated air volume percentage of the microporous sheet may be greater than 50% or 50%, such as 55%, 60%, or 65%, or 50–75%, 55–70%, or 60–65%. The microporous sheet may be a single layer of material, or it may contain two or more layers of material, with or without interlayers of different materials between them. Non-limiting examples of suitable surface treatment agents for the microporous sheet include TESLIN products, all available from PPG, such as TESLIN SP, TESLIN HD, TESLIN TS, TESLIN SPID, TESLIN Digital, TESLIN IJWP, TESLIN Security-Grade, TESLIN Food-Grade, TESLIN Bio, TESLIN BLUE, and / or TESLIN EMI / RF.

[0019] The microporous sheets according to this disclosure typically include a polyolefin polymer matrix, a finely pulverized particulate inorganic filler distributed throughout the matrix, and an interconnected pore network that communicates throughout the microporous sheet.

[0020] As used herein, “microporous material,” “microporous membrane,” “microporous sheet,” and similar terms are used interchangeably and mean a material having an interconnected pore network, in its untreated, uncoated, unprinted, unimpregnated, and pre-bonded state, with pores having a volume-average diameter in the range of 0.001 to 1.0 micrometers and constituting at least 5 volume percent of the microporous material.

[0021] The polyolefin polymer matrix may include any of the numerous polyolefin materials known in the art. In some cases, different polymers derived from ethylenically unsaturated monomers may be used in combination with the polyolefin polymer. Preferred examples of such polyolefin polymers include polymers derived from ethylene, propylene, and / or butene, such as polyethylene, polypropylene, and polybutene. High-density and / or ultra-high molecular weight (UHMW) polyolefins, such as high-density polyethylene, are also preferred. The polyolefin matrix may also include copolymers, for example, copolymers of ethylene and butene, or copolymers of ethylene and propylene.

[0022] If desired, other thermoplastic organic polymers may also be present in the matrix of the microporous material, provided that their presence does not substantially affect the properties of the microporous material substrate in an unfavorable manner. The amount of other thermoplastic polymers that may be present depends on the properties of such polymers. Non-limiting examples of thermoplastic organic polymers that may be present in the matrix of the microporous material include low-density polyethylene, high-density polyethylene, poly(tetrafluoroethylene), polypropylene, copolymers of ethylene and propylene, copolymers of ethylene and acrylic acid, and copolymers of ethylene and methacrylic acid. If desired, all or part of the carboxyl groups of carboxyl-containing copolymers can be neutralized with sodium, zinc, etc.

[0023] The microporous sheet of this disclosure may further include finely pulverized particulate inorganic fillers distributed throughout the matrix.

[0024] Inorganic fillers may include any of the numerous inorganic fillers known in the art. The fillers may be pulverized and substantially water-insoluble to allow for uniform distribution throughout the polyolefin polymer matrix during the production of microporous materials. Generally, inorganic fillers include silica, alumina, calcium oxide, zinc oxide, magnesium oxide, titanium oxide, zirconium oxide, and mixtures thereof.

[0025] The filler can be in the form of ultimate particles, aggregates of ultimate particles, or a combination of both. At least about 90 weight percent of the filler used in preparing the microporous material can have a total particle diameter in the range of 5 to about 40 micrometers as determined by use of a Beckman Coulton laser diffraction particle size instrument LS230. Typically, at least 90 weight percent of the filler has a total particle diameter in the range of 10 to 30 micrometers as determined by use of a Beckman Coulton laser diffraction particle size instrument LS230. The size of the filler aggregates can be reduced during processing of the components used to prepare the microporous material. Thus, the distribution of the total particle diameter in the microporous material may be smaller than that of the raw filler itself.

[0026] In addition to the filler, other micronized particulate materials can also be employed. Non-limiting examples of such optional materials can include carbon black, charcoal, graphite, iron oxide, copper oxide, antimony oxide, molybdenum disulfide, zinc sulfide, barium sulfate, strontium sulfate, calcium carbonate, and magnesium carbonate. Silica alone or in combination with one or more additional filler materials is particularly suitable.

[0027] The filler typically has a large surface area and is capable of supporting most of the processing plasticizer used for the filler to form the microporous material, as defined below. The filler with a large surface area is a material with a small particle diameter, a material with high porosity, or a material exhibiting both characteristics. The surface area of the filler particles is in the range of 20 to 900 square meters per gram, for example, 25 to 850 square meters per gram, as determined by the Brunauer, Emmett, Teller (BET) method according to ASTM C819-77, using nitrogen as the adsorbate and adjusting the system and sample by degassing at 130 °C for 1 hour. Before nitrogen adsorption, the filler sample is dried by heating to 160 °C in flowing nitrogen (PS) for 1 hour.

[0028] The inorganic filler may include silica, such as precipitated silica, silica gel, or fumed silica.

[0029] Different precipitated silicas can be employed as fillers used to prepare the microporous material. Precipitated silicas are well-known commercial materials, and the processes for producing them are described in detail in many U.S. patents, including U.S. Patent Nos. 2,940,830, 2,940,830, and 4,681,750. The average ultimate particle size of the precipitated silica used (regardless of whether the ultimate particle sizes are aggregated or not) is generally less than 0.1 micrometer, such as less than 0.05 micrometer, or less than 0.03 micrometer when determined by transmission electron microscopy. Non-limiting examples of suitable precipitated silicas include those sold under the trade name Hi-Sil® available from PPG.

[0030] The inorganic filler particles can constitute at least 10 weight percent, or at least 25 weight percent, or at least 30 weight percent, or at least 40 weight percent, or at least 50 weight percent, or at least 60 weight percent, and up to 90 weight percent, or up to 85 weight percent, or up to 70 weight percent of the microporous membrane. For example, a microporous sheet may contain 10–90 weight percent, or 25–90 weight percent, or 30–90 weight percent, or 40–90 weight percent, or 50–90 weight percent, or 60–90 weight percent, or 10–85 weight percent, or 25–85 weight percent, or 30–85 weight percent, or 40–85 weight percent, or 50–85 weight percent, or 60–85 weight percent, or 10–70 weight percent, or 25–70 weight percent, or 30–70 weight percent, or 40–70 weight percent, or 50–70 weight percent, or 60–70 weight percent, based on the total weight of the microporous sheet. The filler is typically present in the microporous sheet in amounts ranging from 50 weight percent to about 85 weight percent of the microporous sheet. The weight ratio of filler to polyolefin in the microporous sheet may range from 0.5:1 to 10:1, such as 1.7:1 to 3.5:1. Alternatively, the weight ratio of filler to polyolefin in the microporous sheet may be greater than 4:1. It is intended that higher levels of filler may be used because they provide a larger surface area available for condensation reactions with the treatment composition.

[0031] The microporous material used in the molded transport component of this disclosure further includes an interconnected network of pores that are in communication throughout the microporous material.

[0032] In the untreated, uncoated, or unimpregnated state, such pores can account for at least 5 volume percent of the porous material, for example, at least 5–95 volume percent, or at least 15–90 volume percent, or at least 20–85 volume percent, or at least 25–80 volume percent, or 35–75 volume percent. Often, pores account for at least 35 volume percent, or even more than 45 volume percent, of the microporous material.

[0033] Where used herein, the porosity (also known as void volume) of a microporous material, expressed as a volume percentage, may be determined according to the following formula: Formula I: Porosity=100[1-d1 / d2] In the formula, d1 is the density of the sample, and d2 is the density of the solid portion of the sample.

[0034] Porosity can be measured using a Gurley densometer, Model 4340, manufactured by GPI Gurley Precision Instruments (Troy, NY). The reported porosity value is a measure of the velocity of airflow through the sample or the resistance to airflow through the sample. The unit of measurement for this method is the "Gurley second," which represents the time in seconds for 100 cc of air to pass through a 1-inch square area, using a 4.88-inch water pressure difference. A lower value corresponds to less airflow resistance (more air is allowed to pass through freely). For the purposes of this disclosure, the measurement is completed using the procedure enumerated in the instruction manual for the Model 4340 automatic densometer.

[0035] The volume-average pore diameter of microporous materials can be determined by mercury porosimetry using an Autopore III porosimeter (Micromeretics, Inc.) according to the accompanying operating instructions. The volume-average pore radius in a single scan is automatically determined by the porosimeter. When operating the porosimeter, scans should be performed in the high-pressure range (absolute pressure 138 kilopascals to absolute pressure 227 megapascals). If approximately 2 percent or less of the total penetration volume occurs at the lower end of the high-pressure range (absolute pressure 138 to 250 kilopascals), the volume-average pore diameter should be twice the volume-average pore radius measured by the porosimeter. Otherwise, perform an additional scan in the low-pressure range (absolute pressure 7 to 165 kilopascals) and calculate the volume-average pore diameter using the following formula: Formula II: d=2[v1r1 / w1+v2r2 / w2] / [v1 / w1+v2 / w2] In the formula, d represents the volume-average pore diameter, v1 is the total volume of mercury that penetrated in the high-pressure range, v2 is the total volume of mercury that penetrated in the low-pressure range, r1 is the volume-average pore radius determined from the high-pressure scan, r2 is the volume-average pore radius determined from the low-pressure scan, w1 is the weight of the sample subjected to the high-pressure scan, and w2 is the weight of the sample subjected to the low-pressure scan.

[0036] When determining the volume-average pore diameter using Equation II, the detected maximum pore radius may be taken from high-pressure or low-pressure range scans. The maximum pore diameter is twice the maximum pore radius. Since several generation or processing steps, e.g., coating processes, printing processes, impregnation processes, and / or bonding processes, can result in filling at least some of the pores in a microporous material, and some of these processes irreversibly compress the microporous material, the parameters relating to porosity, volume-average pore diameter, and maximum pore diameter are determined for the microporous material before the application of one or more of such generation or processing steps.

[0037] Microporous materials can be prepared by mixing a filler, a polyolefin polymer (typically in solid form such as powder or pellets), a processing plasticizer, and small amounts of lubricants and antioxidants until a substantially homogeneous mixture is obtained. The weight ratio of filler to polymer used in forming the mixture is essentially the same as the weight ratio of the resulting microporous material substrate. The mixture, along with additional processing plasticizers, can be introduced into a heated barrel of a screw extruder. Dies, such as seating dies, can be attached to the extruder to form the desired final shape.

[0038] When the material is formed into a sheet or film, the continuous sheet or film formed by the die may be fed to a pair of heated calender rolls that work together to form a continuous sheet thinner than the continuous sheet coming out of the die.

[0039] If necessary, the sheet exiting the calender roll may then be stretched in at least one stretching direction above the elastic limit. Stretching may also be performed multiple times during or immediately after exiting the sheeting die, during calendering, or during the manufacturing process. Stretching may be performed before extraction, after extraction, or both. Additionally, stretching may be performed during the application of the first and / or second treatment compositions, which are described in more detail below. Stretched microporous material substrates may be produced by stretching the intermediate product in at least one stretching direction above the elastic limit. The stretch ratio may be in the range of at least 1.2, e.g., at least 1.5 or at least 2, e.g., 1.2–15, 1.5–10, or 2–6.

[0040] The microporous sheet may have a final thickness of at least 4 mils (101.6 microns), or at least 5 mils (127 microns), or at least 6 mils (152 microns), and up to 25 mils (635 microns), or up to 18 mils (457 microns), or up to 14 mils (356 microns). For example, a microporous sheet may have a thickness ranging from 4 to 25 mils (101.6 to 635 microns), or 5 to 25 mils (127 to 635 microns), or 6 to 25 mils (152 to 635 microns), or 4 to 18 mils (101.6 to 457 microns), or 5 to 18 mils (127 to 457 microns), or 6 to 18 mils (152 to 457 microns), or 4 to 14 mils (101.6 to 356 microns), or 5 to 14 mils (127 to 356 microns), or 6 to 14 mils (152 to 356 microns).

[0041] Microporous sheets may further include any organic or inorganic surface treatments, tie coats, additives, functional groups, resins, plasticizers, processing aids, colorants, pigments, additives, coatings, inks, corrosion modifiers, compounds or materials for protection against lightning strikes (such as metal foil, conductive coatings, or conductive woven sheets bonded to the microporous sheet), or other performance-enhancing modifiers, which may be incorporated during any stage of the manufacture of the microporous sheet or applied to the microporous sheet by any means known in the art. Microporous sheet surface treatment agents may include thermally stable coatings for improving transport and release properties, higher or lower densities, components for increasing or decreasing stiffness, fracture resistance, gouging resistance, and / or tear resistance, biodegradability, electromagnetic interference / radio frequency shielding, etc. In addition, surface treatment agents may be treated as described in U.S. Patent No. 10,888,824 B2, which is incorporated herein by reference in whole. As used herein, “colorant” means any substance that imparts color and / or other opacity and / or other visual effects to a composition.

[0042] According to this disclosure, microporous sheets may be adaptable to the needs of the user. For example, a microporous sheet may be adapted to increase adhesion to any subsequent layers applied to the sheet, such as composite materials and / or coating layers. A microporous sheet may be adapted to have a selectively peelable surface, for example, during surface repair, so that subsequent coating layers can be easily removed / peeled. The sheet may be formulated to have functional groups, for example, silica particles used as inorganic fillers may be surface-functionalized before or after their incorporation into a polyolefin polymer matrix. The sheet may be formulated to include reinforcing materials and / or materials that impart lightning protection to a molded article, such as metal foil, both of which are described in U.S. Patent Application Publications 2010 / 103582 and 2018 / 257790, both of which are incorporated by reference in the relevant parts of this Spec. The sheet may be adapted to increase the UV resistance of a molded article, for example, by incorporating UV absorbers into the microporous sheet.

[0043] Molded articles such as components of transport systems can be manufactured using molding methods known in the art, including compression molding such as high-pressure transfer molding, casting, blow molding, compression resin transfer molding or melt molding; extrusion molding, transfer molding, injection molding, for example, gas-assisted injection molding and injection overmolding, structural foam molding, lamination and / or reaction injection molding, matrix molding, rotational molding, spin casting, transfer molding, thermoforming such as twin-sheet thermoforming and vacuum forming; FRP (glass fiber reinforced plastic) molding such as hydroforming and hand lay-up molding; resin transfer molding, vacuum bag molding, bladder molding, spray-up molding, reaction injection molding, pultrusion, and combinations and variations thereof.

[0044] The molded article can be produced using a molding method that includes, but is not limited to, external or internal release agents, and other additional components known in the art.

[0045] The present disclosure provides a method for producing a molded transport component, comprising: 1) lining at least a portion of the inside of a mold with a microporous sheet; 2) adding a composite material on top of the microporous sheet of the mold; 3) closing the mold; and 4) curing or otherwise hardening the composite material.

[0046] The microporous sheet is typically positioned within the mold so that it covers at least a portion of the mold's interior before the composite material is added. During the molding process, the sheet adheres to the composite material. Thus, the adhesion of the sheet to the composite material occurs during the molding process. Importantly, adhesion can be achieved without any additional steps, such as applying chemical treatment to either the sheet or the composite material, or performing physical treatment, and / or process steps to increase adhesion. The deformability of the sheet allows it to be stretched, lengthened, etc., as needed to conform to the composite material. If desired, one or more additional components, such as the lightning foil described above, can be positioned between the microporous sheet and the composite material. Applying two microporous sheets having foil or any other desired material between "sandwich" formations is also within this disclosure.

[0047] While microporous sheets are compatible with composite materials, they are not compatible with the surface roughness of the composite material. This can be achieved, though not necessarily, by filling defects, dry fibers, pinholes, etc., in the composite material, and the inventors do not wish to be constrained by the mechanism. Therefore, the molded transport mechanism components according to this disclosure have a surface roughness less than that of an equivalent composite material without the microporous sheet acting as a surface treatment agent. As demonstrated in the following examples, Ra can be reduced by half or more using the surface treatment agent according to this disclosure. For example, a molded composite material containing a microporous sheet has a surface roughness that is at least 10% lower, e.g., at least 20% lower, or at least 30% lower, or at least 40% lower, or at least 50% lower, or at least 60% lower, or at least 70% lower than an equivalent molded composite material without a microporous sheet. Ra can be further reduced by applying one or more coating layers. For example, a coated molded composite material containing a microporous sheet has a surface roughness that is at least 40% lower, e.g., at least 50% lower, or at least 60% lower, or at least 70% lower, or at least 80% lower, or at least 90% lower, or at least 95% lower than an equivalent coated molded composite material without a microporous sheet.

[0048] The molded articles of this disclosure can often be coated after molding without post-curing sanding, due to the smoothness of the surface treatment agent. One or more coating layers may be applied to the surface of the molded article. For example, one or more coating layers may be applied following an adhesive layer, such as a base coat layer and a clear coat layer, a monocoat layer, or two base coat layers. The coating layers may include tie layers, printed designs such as logos or decorative designs, or selectively peelable layers such as labels, as disclosed in US2006 / 004139, US2006 / 106157, and US2006 / 106161, all of which are incorporated by reference in the relevant parts of this specification. The coating layers may be in any form such as liquid, paste, powder, or sheet, and may be applied by any means known to those skilled in the art when removing the molded article of this disclosure from the mold cavity. If necessary, the coating layer may be applied as part of one or more molding steps, such as, but not limited to, the injection of the coating into the mold between the microporous sheet layer and the mold cavity.

[0049] Microporous sheets may be coated with solvent-based coatings or the like before insertion into a mold. Before insertion into the mold, the coating may be applied to the microporous sheet by any means known to those skilled in the art. If necessary, the microporous sheet may come into contact with a surface layer, such as a coating layer, such as a film, such as a liquid coating layer or laminate, such as an organic or inorganic polymer or coating sheet, with or without backing support material, before or during the process of insertion into the mold. Microporous sheets do not need to be coated before insertion into the mold.

[0050] The molded articles of this disclosure may result in lighter components than conventional molded transport components. The molded articles of this disclosure may also be achieved through more streamlined procedures compared to conventional molded articles. For example, sanding steps may be eliminated or reduced. The use of microporous sheets may provide additional stress and strain resistance to the molded articles, depending on the thickness of the sheet and the strength of the composite material; for example, relatively thick sheets (e.g., greater than 10 mils) may provide greater structural stability. Microporous sheets may provide barrier properties to the molded articles, including corrosion resistance, such as protection against galvanic corrosion in areas where metal fasteners are used to attach the articles to other components.

[0051] The molded articles of this disclosure can be used in any manufactured articles such as transport vehicles or structures. As used herein, “structures” means buildings, bridges, transport infrastructure, oil drilling rigs, oil platforms, water towers, power transmission towers, support structures, wind turbine blades, walls, piers, docks, dikes, dams, shipping containers, trailers, and any part of any metal structure exposed to a corrosive environment. As used herein, “transport vehicles” means, in its broadest sense, all types of transport vehicles, including but not limited to automobiles, trucks, buses, tractors, harvesters, heavy machinery, vans, golf carts, motorcycles, bicycles, railcars, subway cars, airplanes, helicopters, and boats of all sizes.

[0052] Any numerical range described herein is intended to include all partial ranges contained therein. The singular form encompasses the plural form, and vice versa. For example, this specification refers to “a” molded articles, “a” composite materials, “a” microporous sheets, etc., but one or more of each of these and any other components may be used. As used herein, the term “polymer” refers to both prepolymers, oligomers, and homopolymers and copolymers, and the prefix “poly” refers to two or more. “Polymer” and “resin” may be used interchangeably herein. “Including,” “such as,” “for example,” and similar terms mean “including / such as / for example, but not limited to.” This disclosure is described in terms of “comprising,” but the terms “essentially consisting of” and “consisting of” are also within the scope of this disclosure.

[0053] The following examples are intended to illustrate the disclosure and should not be construed as limiting it. It should be understood that the disclosures herein are not necessarily limited to the examples described in this section. Components that are mentioned elsewhere herein as suitable alternative materials for use but not demonstrated in the following examples are expected to provide results comparable to their demonstrated counterparts. [Examples]

[0054] Flat, compression-molded, fiber-reinforced polyurethane composite panels were prepared with or without the use of standard external release agents and / or with or without microporous membrane sheets as surface treatment agents. Microporous sheets were lined to at least a portion of the inside of the mold, a curable composite material was added on top of the microporous sheets in the mold, the mold was closed, and the composite material was cured to form a polyurethane composite.

[0055] The molded composite panels were coated using standard sealer / colored basecoat / clearcoat processes as described in Table 1, or using processes including adhesion promoters as described in Table 2. All products listed in Tables 1 and 2 are available from PPG Industries, Inc. and were applied according to the manufacturer's instructions. [Table 1]

[0056] Coated panels were tested for cross-hatch adhesion after 1 and 7 days using ASTM D3359-23 standard test method B for rating adhesion by tape test, as follows: Eleven parallel cuts were made at 2 mm intervals using a cutting device. The length of the cuts was approximately 35 mm. Cuts were made through the coating and surface treatment agent into the fiber-reinforced polyurethane composite. After making the eleven parallel cuts, the surface was gently cleaned with a soft brush or towel. Eleven additional cuts were made at 90° to the original cuts and centered on them. Tape was positioned in the grid of cuts and quickly removed after 5 seconds. The eleven parallel lines at both 0° and 90° created a grid with 100 squares. After removing the tape, the number of detached squares in the grid (if any) was counted and the edges of the squares were checked for smoothness. The adhesion test result was graded based on the area of ​​detachment. For example, if the edges of the cut were smooth and there were no peeled squares, the grade was 5B (highest performance). If less than 5% of the area was affected, the grade was 4B.

[0057] Table 3 shows the cross-hatch bonding results of molded composite panels coated using coating process C or coating process A with an adhesion promoter applied before coating. All coated panels, including molded composites surface-treated with Teslin, showed an adhesion grade of 5B. [Table 2]

[0058] Surface roughness was measured on molded composite panels using a Mitutoyo Profilometer (Surftest SJ-210). Line scans were used at three locations on the panel (top, middle, and bottom), and the average of the three measurements was reported as Ra. Surface roughness was measured on molded composite panels with and without the coating systems described in Table 1. The surface roughness is shown in Table 4. [Table 3]

[0059] As shown in Table 4, the molded composite articles of this disclosure (Examples 1, 1C, 3, and 3C) demonstrated improved smoothness compared to the corresponding articles without surface treatment agents. Specifically, the average surface roughness (Ra) of uncoated molded composite panels with the surface treatment agents Teslin SP 700 and Teslin 1400 (Examples 1 and 3) was lower than that of uncoated molded composite panels without Teslin (Example X), and the examples with coatings provided similar results. Examples 1C and 3C had lower average surface roughness than Example XC.

[0060] While certain aspects of this disclosure are described in detail, it will be understood by those skilled in the art that various modifications and alternatives to those details can be developed in light of the overall teachings of this disclosure. Therefore, the specific configurations disclosed are illustrative and not limiting to the scope of this disclosure, which gives the entire scope of the appended claims and any and all equivalents thereof.

Claims

1. A molded transport system component, １） a) Polymer resins, and b) A composite material comprising a fibrous reinforcing material containing fibers having lengths of 0.5 to 12 mm, 0.5 to 6 mm, 0.5 to 3 mm, 3 to 6 mm, or 3 to 12 mm distributed throughout the polymer resin, 2) A molded transport mechanism component comprising a microporous sheet bonded to the composite material, the microporous sheet comprising a polyolefin polymer matrix, a finely pulverized particulate inorganic filler distributed throughout the matrix, and an interconnected pore network communicating throughout the microporous sheet, and a surface treatment agent including the microporous sheet.

2. The molded transport component according to claim 1, wherein the composite material includes a sheet-molded compound, a bulk-molded compound, a thermoplastic or thermosetting molded compound, a polymer matrix composite, a metal matrix composite, a ceramic matrix composite, or a combination thereof.

3. The molded transport component according to claim 1 or 2, wherein the polymer resin comprises polyurethane, polyamine, acrylonitrile-butadiene-styrene, low-density polyethylene, high-density polyethylene, polycarbonate, polyamide, high-impact polystyrene, polypropylene, polyether ketone, epoxy resin, phenolic resin, melamine resin, urea resin, polyaryl ether ketone, polyoxymethylene, polystyrene, polyester, polyimide, polyacetal, polyphenylene oxide, polyphenylene sulfide, polyether sulfone, cyclic polyolefin, copolymer of norbornene monomer and olefin monomer, vinyl polymer, cellulose resin, maleimide resin, halogenated resin, silicone, inorganic resin, organic / inorganic hybrid resin, or a combination thereof.

4. The molded transport mechanism component according to any one of the prior claims, wherein the fibers have a width of 5 to 20 microns, or 5 to 10 microns, or 5 to 7 microns, or 6 to 20 microns, or 6 to 10 microns, or 6 to 7 microns.

5. A molded transport component according to any one of the prior claims, wherein the microporous sheet comprises 10 to 90 weight percent, or 25 to 90 weight percent, or 30 to 90 weight percent, or 40 to 90 weight percent, or 50 to 90 weight percent, or 60 to 90 weight percent, or 10 to 85 weight percent, or 25 to 85 weight percent, or 30 to 85 weight percent, or 40 to 85 weight percent, or 50 to 85 weight percent, or 60 to 85 weight percent, or 10 to 70 weight percent, or 25 to 70 weight percent, or 30 to 70 weight percent, or 40 to 70 weight percent, or 50 to 70 weight percent, or 60 to 70 weight percent, based on the total weight of the microporous sheet.

6. The molded transport mechanism component according to any one of the prior claims, wherein the microporous sheet has a thickness of 4 to 25 mils (101.6 to 635 microns), or 5 to 25 mils (127 to 635 microns), or 6 to 25 mils (152 to 635 microns), or 4 to 18 mils (101.6 to 457 microns), or 5 to 18 mils (127 to 457 microns), or 6 to 18 mils (152 to 457 microns), or 4 to 14 mils (101.6 to 356 microns), or 5 to 14 mils (127 to 356 microns), or 6 to 14 mils (152 to 356 microns).

7. A molded transport component according to any one of the prior claims, wherein the microporous sheet (i) has a selectively peelable surface, (ii) contains functional groups, (iii) contains a reinforcing material and / or a material that provides lightning protection to the molded transport component, and / or (iv) increases the UV resistance of the molded transport component.

8. A molded transport mechanism component according to any one of the prior claims, further comprising (i) one or more coating layers including an adhesive layer, a base coat layer, a clear coat layer, a monocoat layer, a tie layer, a printed design, and / or a selectively peelable layer; (ii) one or more lightning foils; and / or (iii) one or more additional microporous sheets.

9. The molded transport component according to any one of the prior claims, wherein the average surface roughness of the molded transport component is at least 10% lower, or at least 20% lower, than the average surface roughness of a molded transport component that includes a composite material but to which the surface treatment agent is not adhered.

10. A molded transport system component, １） a) Polymer resins, and b) A composite material comprising a fibrous reinforcing material containing fibers having a tensile strength of 300 to 7000 MPa, or 300 to 5000 MPa, or 300 to 2000 MPa, or 500 to 7000 MPa, or 500 to 5000 MPa, or 500 to 2000 MPa, 2) A molded transport mechanism component comprising a microporous sheet bonded to the composite material, the microporous sheet comprising a polyolefin polymer matrix, a finely pulverized particulate inorganic filler distributed throughout the matrix, and an interconnected pore network communicating throughout the microporous sheet, and a surface treatment agent including the microporous sheet.

11. The molded transport component according to claim 10, wherein the composite material includes a sheet-molded compound, a bulk-molded compound, a thermoplastic or thermosetting molded compound, a polymer matrix composite, a metal matrix composite, a ceramic matrix composite, or a combination thereof.

12. The molded transport component according to claim 10 or 11, wherein the polymer resin comprises polyurethane, polyamine, acrylonitrile-butadiene-styrene, low-density polyethylene, high-density polyethylene, polycarbonate, polyamide, high-impact polystyrene, polypropylene, polyether ketone, epoxy resin, phenolic resin, melamine resin, urea resin, polyaryl ether ketone, polyoxymethylene, polystyrene, polyester, polyimide, polyacetal, polyphenylene oxide, polyphenylene sulfide, polyether sulfone, cyclic polyolefin, copolymer of norbornene monomer and olefin monomer, vinyl polymer, cellulose resin, maleimide resin, halogenated resin, silicone, inorganic resin, organic / inorganic hybrid resin, or a combination thereof.

13. The molded transport mechanism component according to any one of claims 1 to 12, wherein the fibrous reinforcing material includes a woven sheet, a nonwoven sheet, or a sewn fabric sheet.

14. The molded transport component according to claim 13, wherein the polymer resin is impregnated into the fibrous reinforcing material.

15. A molded transport component according to any one of claims 10 to 14, wherein the microporous sheet comprises 10 to 90 weight percent, or 25 to 90 weight percent, or 30 to 90 weight percent, or 40 to 90 weight percent, or 50 to 90 weight percent, or 60 to 90 weight percent, or 10 to 85 weight percent, or 25 to 85 weight percent, or 30 to 85 weight percent, or 40 to 85 weight percent, or 50 to 85 weight percent, or 60 to 85 weight percent, or 10 to 70 weight percent, or 25 to 70 weight percent, or 30 to 70 weight percent, or 40 to 70 weight percent, or 50 to 70 weight percent, or 60 to 70 weight percent, based on the total weight of the microporous sheet.

16. The molded transport mechanism component according to any one of claims 10 to 15, wherein the microporous sheet has a thickness of 4 to 25 mils (101.6 to 635 microns), or 5 to 25 mils (127 to 635 microns), or 6 to 25 mils (152 to 635 microns), or 4 to 18 mils (101.6 to 457 microns), or 5 to 18 mils (127 to 457 microns), or 6 to 18 mils (152 to 457 microns), or 4 to 14 mils (101.6 to 356 microns), or 5 to 14 mils (127 to 356 microns), or 6 to 14 mils (152 to 356 microns).

17. A molded transport component according to any one of claims 10 to 16, wherein the microporous sheet (i) has a selectively peelable surface, (ii) contains functional groups, (iii) contains a reinforcing material and / or a material that provides lightning protection to the molded transport component, and / or (iv) increases the UV resistance of the molded transport component.

18. A molded transport component according to any one of claims 10 to 17, further comprising: (i) one or more coating layers including an adhesive layer, a base coat layer, a clear coat layer, a monocoat layer, a tie layer, a printed design, and / or a selectively peelable layer; (ii) one or more lightning foils; and / or (iii) one or more additional microporous sheets.

19. The molded transport component according to any one of claims 10 to 18, wherein the average surface roughness of the molded transport component is at least 10% lower, or at least 20% lower, than the average surface roughness of a molded transport component that includes a composite material but to which the surface treatment agent is not adhered.

20. The molded transport component according to any one of claims 1 to 19, wherein the transport is an automobile or an airplane.

21. A method for producing a molded transport component according to any one of the prior claims, comprising: stretching the microporous sheet over at least a portion of the inside of a mold; adding the composite material on the microporous sheet of the mold; closing the mold; and curing the composite material.

22. The method according to claim 21, wherein the method excludes any additional chemical or physical treatment steps to the microporous sheet or the composite material.

23. Use of a molded transport component according to any one of claims 1 to 19 in an automobile or an airplane.

24. A molded component of a structure, １） a) Polymer resins, and b) A composite material comprising a fibrous reinforcing material containing fibers having lengths of 0.5 to 12 mm, 0.5 to 6 mm, 0.5 to 3 mm, 3 to 6 mm, or 3 to 12 mm distributed throughout the polymer resin, 2) A surface treatment agent comprising a microporous sheet bonded to the composite material, the microporous sheet comprising a polyolefin polymer matrix, a finely pulverized particulate inorganic filler distributed throughout the matrix, and an interconnected pore network communicating throughout the microporous sheet, wherein the structure comprises a molded component of a structure including a building, a bridge, transportation infrastructure, an oil drilling rig, an oil platform, a water tower, a power transmission tower, a support structure, a wind turbine blade, a wall, a pier, a dock, a dike, a dam, or a shipping container.

25. A molded component of a structure, １） a) Polymer resins, and b) A composite material comprising a fibrous reinforcing material containing fibers having a tensile strength of 300 to 7000 MPa, or 300 to 5000 MPa, or 300 to 2000 MPa, or 500 to 7000 MPa, or 500 to 5000 MPa, or 500 to 2000 MPa, 2) A surface treatment agent comprising a microporous sheet bonded to the composite material, the microporous sheet comprising a polyolefin polymer matrix, a finely pulverized particulate inorganic filler distributed throughout the matrix, and an interconnected pore network communicating throughout the microporous sheet, wherein the structure comprises a molded component of a structure including a building, a bridge, transportation infrastructure, an oil drilling rig, an oil platform, a water tower, a power transmission tower, a support structure, a wind turbine blade, a wall, a pier, a dock, a dike, a dam, or a shipping container.

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