Flame-retardant polyolefin-based reinforcing screen material

Abstract

The flame-retardant polyolefin-reinforced curtain material of the present invention comprises a flame-retardant layer comprising a polyolefin resin and a flame retardant, and a reinforcing layer composed of polyolefin fibers. Regarding the recycled resin obtained by recycling the flame-retardant polyolefin-reinforced curtain material, the melt flow rate at 230°C and a load of 2.16 kg is 10 g / 10 min or more and 50 g / 10 min or less.

Description

Technical Field

[0001] This disclosure relates to flame-retardant polyolefin-based reinforced curtain materials. Background Technology

[0002] Large-scale curtain materials used in advertising or construction site maintenance have traditionally been waterproof curtain materials made by laminating a layer of vinyl chloride resin onto a polyester fiber substrate. However, while these waterproof curtain materials offer excellent strength and flame retardancy, their inclusion of vinyl chloride resin results in a significant environmental impact upon disposal.

[0003] Therefore, a curtain material consisting of a polyolefin resin layer containing a flame retardant laminated on a polyolefin fiber substrate has been proposed (see, for example, Patent Documents 1 and 2). Such a curtain material, in addition to having good properties such as strength and flame retardancy, can also be recycled, thus reducing the load upon disposal.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2021-109345 Patent Document 2: Japanese Patent Application Publication No. 2023-11232 Summary of the Invention

[0005] The problem that the invention aims to solve However, with the growing global awareness of sustainable development, the importance of recycling resin products has further increased. Therefore, for the aforementioned curtain materials, the goal is not merely to achieve recycling, but also to obtain higher quality resins through recycling, considering factors such as processing adaptability.

[0006] Methods for solving problems This document describes various methods for using flame-retardant polyolefin-based reinforced curtain materials to solve the aforementioned problems.

[0007] [Method 1] A flame-retardant polyolefin-based reinforced curtain material, comprising a flame-retardant layer containing a polyolefin resin and a flame retardant, and a reinforcing layer composed of polyolefin fibers, wherein the melt flow rate of the recycled resin obtained by recycling the above-mentioned reinforced curtain material is 10 g / 10 min or more and 50 g / 10 min or less at 230°C and 2.16 kg load.

[0008] Based on the above composition, the regenerated resin can be well adapted to injection molding and extrusion molding processes.

[0009] [Method 2] According to [Method 1], the flame-retardant polyolefin-based reinforced curtain material, wherein the flame-retardant layer comprises a bromine compound as the flame retardant and a white pigment, and the mass ratio of the materials contained in the flame-retardant layer is: the polyolefin resin is 40% or more and 80% or less, the bromine compound is 10% or more and 20% or less, and the white pigment is 3% or more and 20% or less.

[0010] Based on the above composition, the flame retardancy of the flame-retardant layer can be reliably ensured, and the concealment properties based on the white pigment can be appropriately obtained. Furthermore, the recycled resin used to reinforce the curtain material readily exhibits good physical properties.

[0011] [Method 3] The flame-retardant polyolefin-based reinforced curtain material according to [Method 1] or [Method 2], wherein the flame-retardant layer is composed of a resin composition having a melt flow rate of 8 g / 10 min or more and 30 g / 10 min or less at 230°C and 2.16 kg load.

[0012] Based on the above composition, the resin composition exhibits high adaptability to T-die extrusion molding. By forming the flame-retardant layer using T-die extrusion molding, the flame-retardant layer can be made thinner, resulting in the lightweighting of the reinforced curtain material.

[0013] [Method 4] The flame-retardant polyolefin-based reinforced curtain material according to any one of [Method 1] to [Method 3], wherein the thickness of the flame-retardant layer is 30 μm or more and 200 μm or less.

[0014] Based on the above composition, it is possible to achieve lightweight reinforcement of the curtain material.

[0015] [Method 5] The flame-retardant polyolefin-based reinforced curtain material according to any one of [Method 1] to [Method 4], wherein the dry heat dimensional change rate of the above-mentioned polyolefin fibers at 150°C is in the range of -5% to -50%.

[0016] Based on the above configuration, the reinforcing layer undergoes thermal shrinkage upon ignition, causing the reinforced curtain material to move away from the fire source, and enabling the self-extinguishing of the residual flame in the molten part.

[0017] [Method 6] A flame-retardant polyolefin-based reinforced curtain material according to any one of [Method 1] to [Method 5], wherein the flame-retardant layer is composed of a resin composition having a melt flow rate smaller than that of the resin constituting the polyolefin-based fiber.

[0018] [Method 7] A flame-retardant polyolefin-based reinforced curtain material according to any one of [Method 1] to [Method 6], wherein the flame-retardant layer is composed of a resin composition having a flexural modulus of elasticity smaller than that of the resin constituting the polyolefin-based fiber.

[0019] Based on the above components, the reinforcing function of the reinforcing layer can be reliably ensured, and the resin of the flame-retardant layer will compensate for the physical properties of the resin of the reinforcing layer. As a result, deviations in the characteristics of the recycled resin of the reinforced curtain material can be suppressed, and high-quality recycled resin can be obtained.

[0020] [Method 8] The flame-retardant polyolefin-based reinforced curtain material according to any one of [Method 1] to [Method 7] comprises one of the above-mentioned reinforcing layers and two of the above-mentioned flame-retardant layers sandwiching the reinforcing layer.

[0021] Based on the above configuration, the strength is increased compared to the two-layer structure. Furthermore, since the rigidity of the reinforced curtain material is also increased, processing the reinforced curtain material in printing and other processes becomes easier. Additionally, the reinforced curtain material is less prone to warping.

[0022] [Method 9] The flame-retardant polyolefin-based reinforced curtain material according to any one of [Method 1] to [Method 7] comprises one flame-retardant layer and two reinforcing layers sandwiching the flame-retardant layer.

[0023] Based on the above structure, the strength is improved compared to the two-layer structure. Furthermore, since the rigidity of the reinforced curtain material is also increased, its processing in printing and other processes becomes easier. Additionally, the unique texture of the fabric is reflected in the appearance of the reinforced curtain material, thus enhancing its design appeal. Moreover, wrinkles on the surface of the reinforced curtain material are also suppressed.

[0024] [Method 10] A flame-retardant polyolefin-based reinforced curtain material according to any one of [Method 1] to [Method 9], wherein the reinforced curtain material has a printable surface.

[0025] Based on the above composition, reinforced curtain materials can be appropriately used as decorative materials.

[0026] [Method 11] The flame-retardant polyolefin-based reinforced curtain material according to [Method 10], wherein the polyolefin-based fibers contain pigments.

[0027] Based on the above structure, the concealment can be improved by the reinforcing layer, and print-through can be suppressed when printing is applied to the surface of the reinforced curtain material. Therefore, the reinforced curtain material can be appropriately used as a decorative material.

[0028] Invention Effects According to this disclosure, a recycled resin with high processing adaptability can be obtained. Attached Figure Description

[0029] Figure 1 This is a diagram showing the cross-sectional structure of a first example of a flame-retardant polyolefin-reinforced curtain material according to one embodiment.

[0030] Figure 2This is a diagram showing the cross-sectional structure of a second example of a flame-retardant polyolefin-reinforced curtain material according to one embodiment.

[0031] Figure 3 This is a diagram showing the cross-sectional structure of a third example of a flame-retardant polyolefin-reinforced curtain material according to one embodiment.

[0032] Figure 4 This is a diagram showing the cross-sectional structure of a modified example of the flame-retardant polyolefin-reinforced curtain material described in the first example above.

[0033] Figure 5 This is a diagram showing the cross-sectional structure of a modified example of the flame-retardant polyolefin-reinforced curtain material described in the second example above.

[0034] Figure 6 This is a diagram showing the cross-sectional structure of a modified example of the flame-retardant polyolefin-reinforced curtain material described in the third example above. Detailed Implementation

[0035] Referring to the accompanying drawings, one embodiment of the flame-retardant polyolefin-reinforced curtain material will be described. This embodiment of the flame-retardant polyolefin-reinforced curtain material can be used as a decorative material or as a maintenance material in construction sites, etc. When using the flame-retardant polyolefin-reinforced curtain material as a decorative material, printing can be applied to the surface of the curtain material, making it suitable for use as advertising sheets, banner curtains, vertical curtains, etc.

[0036] [Layer Composition of Flame-Retardant Polyolefin Reinforced Curtain Material] Flame-retardant polyolefin-reinforced curtain materials have a flame-retardant layer comprising polyolefin resin and flame retardant, and a reinforcing layer as a substrate made of polyolefin fibers.

[0037] Figure 1 This is the first example of the layer composition of a flame-retardant polyolefin-based reinforced curtain material 10. The first example, the flame-retardant polyolefin-based reinforced curtain material 10A, has one flame-retardant layer 11 and one reinforcing layer 12. The flame-retardant layer 11 is supported by the reinforcing layer 12.

[0038] According to the first example, since the reinforced curtain material has a two-layer structure, it is possible to achieve a lightweight reinforced curtain material.

[0039] Figure 2 This is a second example of the layer composition of the flame-retardant polyolefin-reinforced curtain material 10. The second example, the flame-retardant polyolefin-reinforced curtain material 10B, has two flame-retardant layers 11 and one reinforcing layer 12. The reinforcing layer 12 is sandwiched between the two flame-retardant layers 11.

[0040] According to the second example, since the reinforced curtain material has a three-layer structure, its strength is increased compared to the two-layer structure. Furthermore, because the rigidity of the reinforced curtain material is also increased, its processing in printing and other processes becomes easier. Additionally, since both sides of the reinforcing layer 12 are covered by the flame-retardant layer 11, warping is less likely to occur due to differences in the materials of the front and back of the reinforced curtain material.

[0041] Figure 3 This is a third example of the layer composition of a flame-retardant polyolefin-reinforced curtain material 10. The third example, the flame-retardant polyolefin-reinforced curtain material 10C, has one flame-retardant layer 11 and two reinforcing layers 12. The flame-retardant layer 11 is sandwiched between the two reinforcing layers 12.

[0042] According to the third example, similar to the second example, the effects of a three-layer structure for reinforcing the curtain material can be achieved. Furthermore, since the reinforcing layer 12, which serves as the fiber substrate, is located on the surface of the reinforcing curtain material, the unique texture of the fabric is evident in its appearance. This also improves the aesthetic design of the reinforcing curtain material. Additionally, wrinkles on the surface of the reinforcing curtain material can be suppressed.

[0043] In the above methods, the flame-retardant layer 11 is formed using T-die extrusion molding, calendering molding, blow molding, etc. When the flame-retardant layer 11 is formed into a thin layer of about 30μm to 200μm, T-die extrusion molding, which offers a high degree of freedom in adjusting manufacturing conditions such as resin ejection rate, die lip width, and traction speed, is suitable. On the other hand, when forming a flame-retardant layer 11 with a thickness exceeding 200μm, calendering molding, which easily increases resin ejection rate and has high productivity, is suitable.

[0044] If T-die extrusion molding is used, the flame-retardant layer 11 can be formed to be thinner, thus achieving a lighter weight for the flame-retardant polyolefin-based reinforced curtain material 10. As a result, the implementability of the reinforced curtain material 10 is improved, and the workload is reduced. The thickness of the flame-retardant layer 11 is preferably 30 μm or more and 200 μm or less.

[0045] In addition, the flame-retardant layer 11 can also be stretched. The stretching ratio is preferably 0.5 times or more and 5 times or less. Even if the flame-retardant layer 11 is stretched, thermal shrinkage will occur when the flame-retardant layer 11 melts during ignition, releasing residual stress and moving the flame-retardant layer 11 away from the fire source. At the same time, the residual flame in the molten part can be self-extinguished by the effect of thermal shrinkage.

[0046] The flame-retardant layer 11 and the reinforcing layer 12 can be bonded together using an adhesive, or the flame-retardant layer 11 can be fused to the reinforcing layer 12 without using an adhesive. In the lamination of the flame-retardant layer 11 and the reinforcing layer 12, lamination processing such as extrusion lamination or hot melt lamination is preferred.

[0047] The flame-retardant polyolefin-based reinforced curtain material 10 may also have a printable side. At least one of the two sides of the reinforced curtain material 10 is printable.

[0048] Specifically, the flame-retardant polyolefin-based reinforced curtain material 10 has a printing substrate on its surface. The surface of the printing substrate is the outermost printable surface of the reinforced curtain material 10.

[0049] Figure 4 The first example of the reinforced curtain material 10A is shown in a manner in which a printing layer 13 is provided. The printing layer 13 is laminated onto the flame-retardant layer 11. Figure 4 In the example shown, one of the two sides of the reinforced curtain material 10A is printable. Figure 5 The second example shows the reinforced curtain material 10B having a printing layer 13. Figure 6 The third example shows a reinforced curtain material 10C having a printing layer 13. Figure 5 , 6 In the example shown, the reinforcing materials 10B and 10C each have a printing substrate 13 on the front and back sides, and both sides of the reinforcing materials 10B and 10C are printable.

[0050] The printing substrate 13 contains an anchoring agent that enhances the adhesion of printing ink to the polyolefin resin. The anchoring agent is, for example, an acrylic or urethane resin.

[0051] In the reinforced curtain material 10, the surface of the laminated substrate 13, which serves as the lower layer of the flame retardant layer 11, may also be subjected to surface treatments such as corona discharge treatment, chromic acid oxidation treatment (wet), flame treatment, hot air treatment, ozone / plasma irradiation treatment, and easy-to-adhere treatment.

[0052] These surface treatments improve the wettability of the coating liquid used to form the substrate layer 13 on the underlying surface, thus improving the adhesion of the substrate layer 13 to the underlying layer. The surface treatment method can be selected according to the type of the underlying layer. From the viewpoints of adhesion effect with the substrate layer 13 and operability of the treatment device, corona discharge treatment and ozone / plasma irradiation treatment are preferred.

[0053] Alternatively, the adhesion of the substrate 13 to the substrate can be improved by forming an anchoring layer and a primer layer between the lower layer and the substrate 13. The materials for the anchoring layer and primer layer can be appropriately selected. When using water-based materials such as alcohol-based materials with high surface tension, it is preferable to increase the surface tension to approximately 50 dyn / cm. Furthermore, when using solvent-based materials or urethane materials with low surface tension, even a surface tension of approximately 45 dyn / cm can sometimes provide good coating compatibility.

[0054] In addition, for applications with a very short service life, printing can be performed on the surface of the reinforcing screen 10, which does not have a printing layer 13. Furthermore, when the reinforcing screen 10 is used as a health care material, the reinforcing screen 10 may not have a printing layer 13, and printing on the reinforcing screen 10 may not be performed.

[0055] [Characteristics of Flame-Retardant Polyolefin Reinforced Curtain Materials] The melt flow rate (MFR) of the recycled resin obtained by recycling the flame-retardant polyolefin-based reinforced curtain material 10 is above 10 g / 10 min and below 50 g / 10 min.

[0056] In the material recycling process, after the reinforced curtain material 10 is crushed and melted, it is molded into granules to generate recycled resin.

[0057] The MFR of the recycled resin was determined according to JIS K7210-1:2014 (ISO 1133-1:2011). The temperature conditions were 230°C and the load was 2.16 kg. By keeping the MFR of the recycled resin within the above range, good processing adaptability to versatile processing methods such as injection molding and extrusion molding can be obtained. Therefore, these processing methods can be used in the processing of recycled resin, thus increasing the freedom of application of recycled resin.

[0058] The MFR of the recycled resin can be controlled by adjusting the MFR of the constituent layers of the flame-retardant polyolefin-reinforced curtain material 10. In addition, since the proportion of the substrate layer 13 in the flame-retardant polyolefin-reinforced curtain material 10 is at most about 2% by mass, the substrate layer 13 has a minimal impact on the MFR of the recycled resin.

[0059] The following is a detailed description of the constituent layers of the flame-retardant polyolefin-reinforced curtain material 10.

[0060] [Flame-retardant layer] The flame-retardant layer 11 comprises a polyolefin resin and a flame retardant. Preferably, the flame-retardant layer 11 further contains a white pigment and various additives. Details of each material and the physical properties of the flame-retardant layer 11 are described below.

[0061] (Polyolefin resin) Examples of polyolefin resins include syndiotactic polypropylene, isotactic polypropylene, atactic polypropylene, homopolymer polypropylene, atactic polypropylene, block polypropylene, ethylene-α-olefin copolymer, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylate copolymer, ethylene-methylmethacrylic acid copolymer, ethylene-methylmethacrylate copolymer, ethylene-ethylacrylic acid copolymer, ethylene-ethylacrylate copolymer, etc. The flame-retardant layer 11 may contain one type of polyolefin resin or two or more types of resin.

[0062] Polyolefin resins can be manufactured by free radical polymerization or ionic polymerization. Polyethylene resins manufactured by free radical polymerization contain homopolymers of ethylene and copolymers of ethylene with monomers that can undergo free radical polymerization with the ethylene.

[0063] Polypropylene resin is preferably used as the polyolefin resin. When the flame retardant layer 11 is formed by calendering, the lamination temperature of the reinforcing layer 12 is lower, so the proportion of polyethylene resin in the flame retardant layer 11 can be increased to improve the lamination-based bonding strength of the flame retardant layer 11 to the reinforcing layer 12.

[0064] Polyolefin resins can include biomass resins. Examples of biomass resins are biomass polyethylene resin and biomass polypropylene resin. Biomass resins are resins produced using renewable biological resources derived from plants, etc. For example, biomass resins are produced by polymerizing monomers derived from plants. Known methods can be used to manufacture biomass resins. By including biomass resins in polyolefin resins, flame-retardant polyolefin-reinforced curtain materials 10 that contribute to carbon neutrality can be achieved.

[0065] Polyolefin resins can comprise both fossil fuel-derived resins and biomass resins. For example, polyolefin resins can comprise fossil fuel-derived polypropylene resins and biomass-derived polyethylene resins. The proportion of biomass resin in the polyolefin resin is preferably less than 50% by mass. With such a composition, the properties of the flame-retardant layer 11 can be well maintained, and carbon neutrality can be facilitated.

[0066] By measuring the radioactive carbon (C14) in polyolefin resins, the proportion of biomaterials derived from the resins, i.e., the biomass content, can be calculated. Since atmospheric carbon dioxide contains C14 at a constant proportion (105.5 pMC), the C14 concentration in plants that grow by ingesting atmospheric carbon dioxide is also approximately 105.5 pMC. On the other hand, fossil fuels contain almost no C14.

[0067] Therefore, the biomass fraction can be calculated by determining the proportion of C14 in all carbon atoms of the polyolefin resin. The biomass fraction Pbio (%) can be calculated by setting the C14 concentration in the polyolefin resin as Pc (pMC) and using the following formula (1).

[0068] Pbio=(Pc / 105.5)×100 (1) When all the polyolefin resins contained in the flame-retardant layer 11 are bio-derived resins, the biomass content is theoretically 100%. When all the polyolefin resins are derived from fossil fuels, the biomass content is theoretically 0%. Based on this, the presence of biomass resins in the polyolefin resins can be confirmed by measuring the C14 content in the resin composition constituting the flame-retardant layer 11.

[0069] (Flame retardant) As a flame retardant, it is preferable to use both bromine-based compounds and inorganic compounds.

[0070] Bromine-based flame retardants include dripping and non-drip types. Drip-type flame retardants inhibit combustion by dripping liquid. Non-drip-type flame retardants act on the gas phase, inhibiting combustion through the capture of OH radicals, the dilution and blocking of oxygen by the generation of non-flammable gases, etc. In cases where flame retardant layer 11 is formed by T-die extrusion molding, drip-type flame retardants decompose when the film formation of flame retardant layer 11 is carried out at high temperatures; therefore, non-drip-type flame retardants are preferred. Furthermore, decomposition of drip-type flame retardants also occurs when recycled resin is produced in granular form by extrusion molding during recycling processes. Therefore, using non-drip-type flame retardants yields high-quality recycled resin.

[0071] Examples of inorganic compounds include antimony oxide compounds such as antimony trioxide and antimony pentoxide, hydrated metal compounds such as magnesium hydroxide and aluminum hydroxide, and zinc borate. Antimony oxide compounds are particularly preferred. By using antimony oxide compounds in conjunction with bromine compounds, a heavier, non-flammable gas containing antimony is produced upon ignition, thus synergistically improving the oxygen dilution and oxygen blocking effects.

[0072] To ensure flame retardancy, the polyolefin resin is set to 100 by weight, and the flame retardant content in the flame retardant layer 11 is preferably 7 or more. Furthermore, to prevent the MFR of the resin composition used to form the flame retardant layer 11 from becoming too high, the polyolefin resin is set to 100 by weight, and the flame retardant content in the flame retardant layer 11 is preferably 30 or less.

[0073] (White pigment) When using flame-retardant polyolefin-reinforced curtain material 10 as a decorative material, it is particularly important to suppress color changes such as yellowing caused by ultraviolet radiation.

[0074] Furthermore, when the flame-retardant layer 11 is formed by T-die extrusion as described above, the flame-retardant layer 11 becomes thinner. Therefore, in the reinforced curtain material 10 of the first and second examples, the color of the reinforcing layer 12 overlapping with the flame-retardant layer 11 becomes more transparent. Therefore, it is preferable to improve the light-shielding properties and whiteness of the flame-retardant layer 11.

[0075] Therefore, in order to improve the whiteness of the flame-retardant layer 11 and thus block light, the flame-retardant layer 11 preferably contains a white pigment. Examples of white pigments are titanium dioxide and barium sulfate. In particular, titanium dioxide is preferred due to its small particle size and high concealing effect.

[0076] There are two main types of titanium dioxide used in industrial applications: rutile and anatase. Rutile, with its higher refractive index, is preferred. Specifically, rutile titanium dioxide has a refractive index of 2.72, while anatase titanium dioxide has a refractive index of 2.52. The refractive index is the primary factor determining the optical properties of inorganic pigments; a higher refractive index results in greater surface reflection, thus increasing light scattering in the resin and consequently increasing its opacity. Therefore, using titanium dioxide with a higher refractive index can mitigate the yellowing of resins caused by ultraviolet radiation.

[0077] Furthermore, titanium dioxide strongly absorbs light with wavelengths shorter than 400 nm, but it does not absorb visible light. Therefore, it exerts a similar effect to light stabilizers and ultraviolet absorbers, and by including titanium dioxide, the content of these additives can be reduced.

[0078] Furthermore, titanium dioxide exhibits photocatalytic activity, exerting a strong oxidizing force on its surface when exposed to light. This property is used industrially for the decomposition of recalcitrant substances; however, if it exerts its oxidizing force in resins or on the surface of flame-retardant polyolefin-reinforced screen material 10, it may lead to resin degradation and deterioration of the printed surface quality. Therefore, it is preferable to surface-treat titanium dioxide to suppress its oxidizing force before use. Examples of surface treatment agents / dispersants include silica, aluminum hydroxide, polydimethylsiloxane, cyclopentasiloxane, triethoxyoctanoylsilane, hydrogenated polydimethylsiloxane, isostearic acid, stearic acid, alumina, sodium polyacrylate, etc.

[0079] In addition, inorganic fillers can improve light-blocking properties, and antimony oxide compounds, magnesium hydroxide, aluminum hydroxide, etc., used as flame retardants can also improve light-blocking properties and whiteness.

[0080] To reliably achieve light-shielding and whitening effects, the polyolefin resin is set to 100 by mass, and the functional components for light-shielding and whitening contained in the flame-retardant layer 11 are preferably 10 or more. Furthermore, the aforementioned functional components are preferably 30 or less by mass, with the polyolefin resin set to 100. If the mass ratio of functional components is 30 or less, the inorganic filler content will not be excessive, thus suppressing resin degradation caused by shear heat during the manufacturing process of the flame-retardant layer 11. Additionally, since the specific gravity will not become excessively high, the reduction in processing adaptability to T-die extrusion molding can also be suppressed.

[0081] (additive) Additives can improve processing stability, weather resistance, and strength. Specific examples of additives include lubricants, antioxidants, light stabilizers, antistatic agents, and ultraviolet absorbers.

[0082] When a large amount of hydrated metal compounds are used as flame retardants, resin degradation caused by shear heat is likely to occur during the manufacturing process of the flame-retardant layer 11. Therefore, it is preferable to add a lubricant. By adding a lubricant to the resin composition used to form the flame-retardant layer 11, friction between the resin and the molding machine, as well as friction between resin particles, can be reduced. For example, hydrocarbon-based, fatty acid-based, aliphatic alcohol-based, aliphatic amide-based, and metal soap-based lubricants can be used. Considering the balance between external and internal lubricity, it is preferable to use a combination of multiple lubricants.

[0083] In addition, to suppress resin degradation caused by shear heat and improve weather resistance intended for outdoor use, it is preferable to add antioxidants. Antioxidants include primary antioxidants that act as free radical scavengers and secondary antioxidants that act as peroxide decomposers.

[0084] As primary antioxidants, phenolic antioxidants are typically found in the form of free radicals. Phenolic antioxidants stabilize free radicals generated by ultraviolet light and heat, as well as alkoxy radicals formed from oxygen. There are three types of phenolic antioxidants with different chemical structures: hindered, semi-hindered, and unhindered. Their free radical capture numbers and reaction rates differ from each other. Generally, polyolefin resins are relatively stable resins, and their oxidation reactions proceed slowly; therefore, slow-acting hindered antioxidants are effective. Representative commercially available phenolic antioxidants include BASF's Irganox series and ADEKA's AO series.

[0085] As secondary antioxidants, sulfur-based or phosphorus-based antioxidants can be used. These antioxidants inhibit oxidation caused by the chain reaction of free radicals generated from hydroperoxides by decomposing hydroperoxides (ROOH), which are reactants that capture free radicals as phenol-based antioxidants, into stable substances.

[0086] However, sulfur-based antioxidants produce an odor at high temperatures and have defects in coloring. Therefore, when manufacturing white reinforced curtain material 10, phosphorus-based antioxidants are preferred. Representative commercially available phosphorus-based antioxidants include BASF's Irgafos 168 and ADEKA's PEP series 2112.

[0087] To suppress resin degradation of the flame-retardant layer 11 caused by ultraviolet exposure, it is preferable to add an ultraviolet absorber.

[0088] Benzotriazole and benzophenone-based UV absorbers can be used as UV absorbers. These absorbers will absorb UV light in the wavelength range of approximately 320nm to 350nm, which is the region most susceptible to UV radiation from the resin.

[0089] Furthermore, even higher light stability can be achieved by using hindered amine light stabilizers (HALS) in conjunction with UV absorbers. HALS capture free radicals generated by UV radiation, thus preventing staining and maintaining gloss. However, when used with brominated compounds as flame retardants, trace amounts of acidic substances are generated in the resin composition under the influence of the brominated compounds. If the HALS is alkaline, neutralization will occur, antagonizing the reaction. Therefore, NOR-type HALS, which are less likely to form salts with acidic substances, are preferred.

[0090] Representative commercially available UV absorbers include BASF's Tinuvin and Uvinul series. The Tinuvin series contains HALS. Representative commercially available HALS products include ADEKA's LA series.

[0091] (Material mixing ratio) The mass ratio of the materials contained in the flame retardant layer 11 is as follows: relative to the total mass of the flame retardant layer 11, preferably, the polyolefin resin is 40% or more and 80% or less, the bromine compound is 10% or more and 20% or less, and the white pigment is 3% or more and 20% or less.

[0092] To obtain good physical properties from the recycled resin, the proportion of polyolefin resin in the flame-retardant layer 11 is preferably 50% by mass or more. However, even if the proportion of polyolefin resin is less than 50% by mass, the recycled resin can still be used sufficiently as a material for molded articles such as those produced by injection molding.

[0093] (MFR) Regarding the resin composition used to form the flame retardant layer 11, the MFR at 230°C and 2.16 kg load is preferably 8 g / 10 min or more and 30 g / 10 min or less.

[0094] As described above, in order to reduce the weight of the flame-retardant polyolefin-reinforced curtain material 10, T-die extrusion molding is preferred. Furthermore, if the MFR of the resin composition is 8 g / 10 min or more and 30 g / 10 min or less, high adaptability to T-die extrusion molding can be obtained.

[0095] If the MFR of the resin composition is as low as approximately 0.5 g / 10 min to 7 g / 10 min, the resin's flowability is too low, making it difficult to increase the extrusion volume using an extrusion molding machine, thus reducing productivity. Increasing the resin temperature can improve the flowability in the molding machine, but it is difficult to significantly improve the flowability. Increasing the extrusion volume will produce a pulsating phenomenon known as tensile resonance, making stable production difficult. Further increasing the resin temperature will improve the tensile resonance, but if the resin temperature is too high, it will cause problems such as degradation due to the resin's thermal history, dissolution or thermal shrinkage of the reinforcing layer 12 during the lamination process of the flame retardant layer 11 onto the reinforcing layer 12, and adhesion due to insufficient cooling after the recycling process of the manufactured curtain material. If the MFR of the resin composition is 8 g / 10 min or higher, these problems can be suppressed.

[0096] On the other hand, if the molecular weight flow rate (MFR) of the resin composition exceeds 30 g / 10 min, the flowability will be greatly improved. However, in order to achieve an MFR greater than 30 g / 10 min, it is necessary to use a resin with a low average molecular weight. If a resin with a low average molecular weight is used, pores are easily formed during the film formation of the flame retardant layer 11, resulting in a significant reduction in formability. If the MFR of the resin composition is below 30 g / 10 min, such problems can be suppressed.

[0097] In addition, if the MFR of the resin composition is 8 g / 10 min or more and 30 g / 10 min or less, it is also easy to control the MFR of the recycled resin of the flame-retardant polyolefin-based reinforced curtain material 10 to be 10 g / 10 min or more and 50 g / 10 min or less.

[0098] To obtain the desired MFR of the resin composition, it is preferable to use a polyolefin resin with an MFR that is about 5 g / 10 min to 10 g / 10 min lower than the desired MFR. Therefore, even if the MFR increases due to the presence of flame retardants, it is easy to control the MFR of the resin composition to the desired value of 30 g / 10 min or less.

[0099] [Reinforcement Layer] (Polyolefin fibers) The polyolefin fibers constituting the reinforcing layer 12 can be made of polyethylene or polypropylene. As an example, the composition of polypropylene fibers is described below.

[0100] The polypropylene resin used to form the fiber is a known resin. The polypropylene resin can be any polymer obtained from monomers with propylene as the main component. For example, the polypropylene resin can be a homopolymer of propylene or a copolymer of propylene with one or more other comonomers. Examples of comonomers are olefinic hydrocarbons such as ethylene and 1-butene.

[0101] Specific examples of copolymers include propylene-ethylene random copolymers, propylene-ethylene-1-butene copolymers, and other propylene-ethylene-α-olefin random copolymers, propylene-1-butene copolymers, propylene-1-pentene copolymers, propylene-1-hexene copolymers, propylene-1-octene copolymers, and other propylene-α-olefin random copolymers. The α-olefin used for copolymerization preferably has 4 to 10 carbon atoms.

[0102] The polypropylene resin constituting the fiber can be a single resin or a mixture of two or more resins. For example, the polypropylene resin can be a mixture of propylene homopolymers with different average molecular weights, or a mixture of propylene homopolymers and the random copolymers exemplified above. In one example, the polypropylene resin can be a mixture of propylene homopolymers and low-crystallinity or amorphous propylene-ethylene random copolymers.

[0103] In addition, when using polypropylene resin that is a homopolymer, isotactic polymers are usually used, but the use of syndiotactic or atactic polymers, or the presence of these polymers in the resin that constitutes the fiber, is also permitted.

[0104] As with the case where the flame-retardant polyolefin-based reinforced curtain material 10 is used as a decorative material, when printing on the surface of the reinforced curtain material 10, a masking pigment can be added to the resin of the fiber material to suppress light penetration. Examples of pigments include black pigments, white pigments, and opaque pigments. For example, when using black pigments, by adding about 3% by mass of black pigment to the polyolefin-based resin, sufficient light-blocking performance can be obtained using the reinforcing layer 12 made of fibers formed from this resin material.

[0105] The dry heat dimensional change rate of the polyolefin fiber at 150°C is preferably within the range of -5% to -50%. The dry heat dimensional change rate is determined according to JIS L1013 B method. The heat treatment time is 30 minutes. If the dry heat dimensional change rate is within the above range, the polyolefin fiber will undergo thermal shrinkage upon ignition, thereby moving the reinforcing layer 12 away from the ignition source and enabling the self-extinguishing of the afterflame in the molten part.

[0106] (Methods for manufacturing fibers) The polyolefin fibers constituting the reinforcing layer 12 can be multifilaments or flat yarns.

[0107] Multifilament yarns are manufactured using melt spinning. Specifically, molten resin is extruded from a spinning nozzle and cooled to obtain undrawn yarn. This undrawn yarn is then heated and drawn again to obtain drawn yarn. Multifilament yarns are then constructed from these drawn yarns. The draw ratio is approximately 3 to 10 times.

[0108] Flat yarn is obtained by forming molten resin into a film through methods such as T-die extrusion or blow molding, cutting the film into strips, and stretching it. The stretching ratio is preferably 3 times or more and 15 times or less, more preferably 5 times or more and 10 times or less. This ensures sufficient strength. To suppress uneven stretching, it is preferable to perform the stretching in multiple segments.

[0109] By finely tearing flat yarn, split-film yarn can be obtained. Flat yarn is a flat, strip-shaped coarse filament; by tearing flat yarn, fine filaments similar to multifilaments can be obtained.

[0110] There is no particular limitation on the thickness of polyolefin fibers. However, when using multifilaments, if the yarns are too thin, they will melt due to frictional heat during the weaving process, reducing productivity. Therefore, the preferred thickness of polyolefin fibers is 100 denier or higher, and the preferred filament count in the multifilament is 48 or higher.

[0111] In addition, polyolefin fibers can also be FTY (Filament Twisted Yarn) and DTY (Draw Textured Yarn).

[0112] Regarding the resin constituting the polyolefin fiber of the reinforcing layer 12, the mean filtration rate (MFR) at 230°C and 2.16 kg load is preferably 20 g / 10 min or more and 50 g / 10 min or less. Generally, the resin constituting the polyolefin fiber is a resin with a fiber manufacturing method, a fiber application, and an MFR corresponding to the desired function. For example, there are fibers made of resins with an MFR of around 5 g / 10 min, and there are fibers made of resins with an MFR exceeding 50 g / 10 min. By varying the properties of the resin, the polyolefin fiber can exhibit various functions, and the substrate made of the polyolefin fiber can be used for various applications.

[0113] As an example, Table 1 shows the characteristics of polyolefin fibers corresponding to their applications. The properties of the yarns for each application are described in the book "Basic Knowledge of Mild Industrial Fibers" published by Nikkan Kogyo Shimbun.

[0114] Thus, the properties of polyolefin fibers vary depending on the physical properties of the resin. Furthermore, the polyolefin fibers of the reinforcing layer 12 preferably use resins that enhance the reinforcing function of the reinforcing layer 12; in other words, resins that increase fiber strength are preferred. Strength can be increased by using resins with a high average molecular weight, i.e., a low molecular weight ratio (MFR). On the other hand, if the MFR is too low, formability decreases, and yarn productivity decreases. From this perspective, the fibers of the reinforcing layer 12 preferably use resins with an MFR of 20 g / 10 min or more and 50 g / 10 min or less.

[0115] Resins with an MFR range of this magnitude are suitable for manufacturing yarns using melt spinning. Therefore, the polyolefin fibers constituting the reinforcing layer 12 are preferably multifilaments.

[0116] In addition, if the MFR of the resin of the reinforcing layer 12 is within the above range, it is also easy to control the MFR of the recycled resin of the flame-retardant polyolefin-based reinforced curtain material 10 to be above 10 g / 10 min and below 50 g / 10 min.

[0117] (Manufacturing method of the reinforcing layer) The reinforcing layer 12 can be a textile, a woven fabric, or a non-woven fabric.

[0118] Textiles have a structure in which warp and weft yarns intersect in an orthogonal manner. They are manufactured by interlacing the weft yarns relative to the parallel warp yarns in a certain regular pattern. The weave structure of textiles, that is, the way the warp and weft yarns interlace, includes plain weave, twill weave, satin weave, leno weave, ribbing, and gauze weave, among others.

[0119] The strength and hand feel of the textile vary depending on the number of warp and weft yarns and the weave structure, but there are no particular limitations in this embodiment. For example, the warp and weft yarn densities are 5 yarns / 2.54cm or more and 40 yarns / 2.54cm or less, preferably 10 yarns / 2.54cm or more and 30 yarns / 2.54cm or less. Examples of commercially available woven fabrics include TarpeeCloth (manufactured by Hagiwara Industrial Co., Ltd.).

[0120] Examples of woven fabrics include Raschel warp knitting, Trico warp knitting, Milanese warp knitting, and other woven materials.

[0121] Alternatively, the reinforcing layer 12 can also be a mesh nonwoven fabric. A mesh nonwoven fabric has a structure in which layers of flat yarns arranged side-by-side are overlapped in a mutually orthogonal manner, and these layers are heated and fused together. Representative commercially available examples of mesh nonwoven fabrics include Warifu (registered trademark, manufactured by JX ANCI), CLAF (registered trademark, manufactured by JX ANCI), and Sof (manufactured by Sekisui Film).

[0122] [Differences in physical properties between flame-retardant layer and reinforcing layer] In the recycled resin of the flame-retardant polyolefin-reinforced curtain material 10, the resin of the flame-retardant layer 11 and the resin of the reinforcing layer 12 are mixed. Therefore, in order to obtain a recycled resin with good properties, it is necessary to consider the balance of the physical properties of the resins of the flame-retardant layer 11 and the reinforcing layer 12.

[0123] Specifically, from the viewpoint of strength and rigidity, it is preferable to use polypropylene resin as an isotactic stereopolymer in the fibers of the reinforcing layer 12. However, the characteristics of a homopolymer are reflected in the resin obtained through the recycling of such a reinforcing layer 12. As a result, the recycled resin of the reinforcing layer 12 has the characteristics of high flexural elasticity and hardness but low impact strength.

[0124] Therefore, polypropylene resin, which is a random polymer, is preferably used as the resin for the flame retardant layer 11. Polypropylene resin, as a random polymer, has a structure in which a small amount of comonomers such as ethylene are randomly incorporated into the propylene chain. As a result, the regular propylene chain is disrupted, thus reducing the crystallinity of the polymer, but making the polymer softer and more viscous, thereby improving its impact resistance.

[0125] Therefore, by using a random polymer as the resin for the flame-retardant layer 11 and utilizing the recycled resin of the flame-retardant polyolefin-reinforced curtain material 10 to compensate for the impact strength, good impact resistance can be obtained.

[0126] Therefore, in order to obtain a recycled resin with good properties, it is preferable to use a viscous resin that is softer and more easily stretched than the resin of the reinforcing layer 12 as the flame retardant layer 11. Specifically, compared with the resin of the polyolefin fibers constituting the reinforcing layer 12, the resin composition constituting the flame retardant layer 11 has a lower flexural modulus, a higher nominal strain at tensile break, and a higher Charpy impact strength. In addition, the MFR of the resin composition of the flame retardant layer 11 is lower than that of the resin of the reinforcing layer 12.

[0127] Therefore, the reinforcing function of the reinforced curtain material 10 in the reinforcing layer 12 can be reliably obtained. On the other hand, deviations in the properties of the recycled resin can be suppressed, resulting in a recycled resin that can be applied to a wide range of uses. In other words, both the reinforced curtain material 10 and the recycled resin can obtain good properties.

[0128] [Example] The above-mentioned flame-retardant polyolefin-based reinforced curtain materials are explained using specific examples and comparative examples.

[0129] (Composition of the flame-retardant polyolefin-reinforced curtain material in Example 1) <Manufacturing Method> The following materials are mixed to generate a resin composition for forming a flame-retardant layer.

[0130] Polyolefin resin: Polypropylene resin (random polymer) 100 parts by weight Flame retardant: 11-21 parts by weight of bromine compound 3-7 parts by weight of antimony oxide compound White pigment: 10-11 parts by weight of titanium dioxide Additives: 0-2 parts by weight of antioxidants, HALS, UVA, lubricants, etc. A flame-retardant layer formed from the above-mentioned resin composition is laminated onto a reinforcing layer via T-die extrusion and lamination to obtain a laminate containing a reinforcing layer sandwiched between two flame-retardant layers. The thickness of the flame-retardant layer is 80 μm. As the reinforcing layer, a plain-weave fabric composed of multifilament yarns is used. The multifilament is polypropylene fiber formed from isotactic homopolymer.

[0131] Both sides of the above-mentioned laminate were subjected to corona discharge treatment to improve the surface wettability to approximately 48 dyn / cm. On the corona-treated surface, a urethane-based anchoring agent was applied using gravure printing, and the coating was allowed to dry and cure, thus forming the substrate layer. The solid content of the anchoring agent in the coating reached 4.0 g / m³. 2 The thickness is approximately [value missing]. Thus, the flame-retardant polyolefin-based reinforced curtain material of Example 1 is obtained.

[0132] <Dry heat dimensional change rate of the reinforcing fiber> For the polypropylene fibers constituting the reinforcing layer of Example 1, the shrinkage rate during heating was determined according to JIS L1013 B method. The results are shown in Table 2. In Condition 1, the treatment temperature was set to 120°C and the treatment time was set to 30 minutes. In Condition 2, the treatment temperature was set to 150°C and the treatment time was set to 30 minutes.

[0133] Table 2 shows that the polypropylene fibers shrink due to heat. By using a reinforcing layer composed of such fibers, when the flame-retardant polyolefin-reinforced curtain material catches fire, it exhibits the ability to keep the reinforced curtain material away from the fire source through thermal shrinkage, and the afterflame of the molten part self-extinguishes.

[0134] Comparison of the physical properties of flame-retardant layers and reinforcing layers MFR, tensile yield stress, tensile fracture stress, tensile fracture nominal strain, flexural strength, flexural modulus, and Charpy impact strength were measured for the resin composition used to form the flame retardant layer of Example 1 and the resin obtained by recycling the reinforcing layer.

[0135] MFR was determined according to ISO 1133 at a temperature of 230°C and a load of 2.16 kg. Tensile yield stress, tensile fracture stress, and nominal strain at fracture were determined according to ISO 527-1 at a tensile speed of 50 mm / min. Flexural strength and flexural modulus were determined according to ISO 178. Charpy impact strength was determined according to ISO 179 using notched test specimens. The results of each property are shown in Table 3.

[0136] As shown in Table 3, compared to the recycled resin of the reinforcing layer, the resin composition of the flame-retardant layer has a lower MFR and a lower flexural modulus, thus it can be described as flexible. Furthermore, compared to the recycled resin of the reinforcing layer, the resin composition of the flame-retardant layer has a higher nominal strain at tensile break, exceeding 435%, thus it can be described as easily elongated. Additionally, compared to the recycled resin of the reinforcing layer, the resin composition of the flame-retardant layer has a higher Charpy impact strength, thus it can be described as viscous.

[0137] (Physical properties of flame-retardant polyolefin-based reinforced curtain materials) For the flame-retardant polyolefin-reinforced curtain materials of Example 1 and the comparative example, the mass, thickness, tensile strength, and tear strength were measured respectively. In the flame-retardant polyolefin-reinforced curtain material of the comparative example, the flame-retardant layer was manufactured by calendering. Calendering emphasizes the viscosity of the resin during the molding process; therefore, in the comparative example, a resin composition with a lower MFR than that of Example 1 was used to form the flame-retardant layer.

[0138] The quality was determined according to JIS L1096 8.3.2. Thickness was determined according to JIS L1096 8.4. Tensile strength was determined according to JIS L1096 8.14.1 Method A (strip method), with a test piece width of 30 mm. Tear strength was determined according to JIS L1096 8.17.4 Method D (pendulum method). The results of each property test are shown in Table 4.

[0139] As shown in Table 4, the flame-retardant polyolefin-reinforced curtain material of Example 1 has a smaller thickness and a mass reduction of less than 50% compared to the comparative example. This is because the flame-retardant layer is formed thinner using extrusion molding. As shown in Table 3, such a molding method and thickness can be achieved by making the MFR of the resin composition of the flame-retardant layer 8 g / 10 min or more and 30 g / 10 min or less.

[0140] In Example 1, as the thickness was reduced, the tensile strength was slightly lower than that of the comparative example, but sufficient strength for practical use was still ensured.

[0141] (Flame retardancy evaluation) For the flame-retardant polyolefin-reinforced curtain material of Example 1, the fire resistance test was conducted using the 45° micro-burner method specified in the fire resistance performance test method of the Ministry of Internal Affairs and Communications Ordinance. In the pretreatment, the reinforced curtain material was immersed in warm water at 50°C for 30 minutes. The test results are shown in Table 5. Furthermore, in this test method, three samples are required for evaluation in the 1-minute heating test and two samples are required for evaluation in the 3-second heating test after ignition. Samples 1-3 used for the 1-minute heating test and samples 1 and 2 used for the 3-second heating test after ignition are different samples.

[0142] As shown in Table 5, the flame-retardant polyolefin-reinforced curtain material of Example 1 was confirmed to exhibit good fire resistance. Therefore, the flame-retardant polyolefin-reinforced curtain material of Example 1 was confirmed to have sufficient flame retardancy.

[0143] (Printability evaluation) For the flame-retardant polyolefin-based reinforced curtain material of Example 1, a pattern was printed on the surface of the substrate using a UV inkjet printer. Then, as an evaluation of printability, the coating adhesion and rubbing fastness were evaluated. The coating adhesion was evaluated according to JIS K5600-5-6 (cross-cut test), with a cut interval of 2 mm. The rubbing fastness was evaluated according to JIS L0849, by observing the color staining of the rubbing cloth and the appearance of the rubbing object. The evaluation results are shown in Table 6.

[0144] As shown in Table 6, the following results were obtained in the evaluation of coating adhesion: it was confirmed as Category 1, i.e., small peeling of the printed coating at the intersection of the cuts, but the affected portion in the gridded area was less than 5%. Furthermore, in the evaluation of rubbing fastness, using a grayscale chart for contamination, a rubbing fastness of approximately level 4-5 was confirmed.

[0145] Therefore, it was confirmed that the flame-retardant polyolefin-reinforced curtain material of Example 1 has good printability, making it difficult for printed coatings to peel off.

[0146] (Recycling Adaptability Evaluation) <Physical Properties of Regenerated Resin> For the flame-retardant polyolefin-based reinforced curtain material of Example 1, a pattern was printed on the surface of the substrate using a UV inkjet printer. Recycled resin was obtained by recycling the reinforced curtain material. The recycling process was carried out using three methods, A through C, and recycled resin was obtained for each method.

[0147] Method A: Using a waste plastic volume reduction machine (Mingnongzhi), volume-reduced sheet material is produced from reinforced curtain material. This volume-reduced sheet material is then granulated using a short-shaft extruder to obtain recycled resin. The volume reduction machine's processing temperature is 200℃. The short-shaft extruder's processing temperature is also 200℃, and impurities are removed using an 80-mesh sieve.

[0148] Method B: Using a one-stop recycling processing machine (100 million units), granular recycled resin is obtained from the reinforced curtain material. The processing temperature is 200℃, and impurities are removed using a 200-mesh sieve.

[0149] Method C: Using a waste plastic volume reduction machine (Mingnong Manufacturing), volume-reduced sheet material is generated from reinforced curtain material. This volume-reduced sheet material is then sieved for sorting, thereby homogenizing its shape and obtaining recycled resin. The processing temperature of the volume reduction machine is 200℃. A 5mm mesh screen is used as the sieve.

[0150] For the regenerated resins obtained by each method, the MFR, tensile yield stress, tensile fracture stress, nominal tensile fracture strain, flexural strength, flexural modulus, and Charpy impact strength were measured respectively.

[0151] MFR was determined according to ISO 1133 at a temperature of 230°C and a load of 2.16 kg. Tensile yield stress, tensile fracture stress, and nominal strain at fracture were determined according to ISO 527-1 at a tensile speed of 50 mm / min. Flexural strength and flexural modulus were determined according to ISO 178. Charpy impact strength was determined according to ISO 179 using notched test specimens. The results of each property are shown in Table 7.

[0152] As shown in Table 7, regardless of which method (A-C) is used, the MFR (Mean Free Rate) of the recycled resin is in the range of 21 g / 10 min to 24 g / 10 min, which is suitable for injection molding and extrusion molding. Furthermore, compared to Table 3, the MFR and flexural modulus are higher than those of the resin composition in the flame-retardant layer, but lower than those of the recycled resin in the reinforcing layer. Moreover, the nominal tensile strain at break is over 435%, and the Charpy impact strength is lower than that of the resin composition in the flame-retardant layer, but higher than that of the recycled resin in the reinforcing layer. Therefore, the properties of the reinforcing layer resin are compensated for by the properties of the flame-retardant layer resin, resulting in a recycled resin with good flexibility, elongation, and viscosity.

[0153] <Processing adaptability of recycled resin> Two molding tests were conducted on each of the recycled resins obtained by methods A to C above.

[0154] [Single-layer film formation experiment using a small T-mold] The recycled resin is molded into sheets according to the following apparatus and manufacturing conditions.

[0155] Equipment used: T-die extrusion molding machine (manufactured by the Institute of Plastics Engineering) Mold width: 150mm Molding temperature: 230℃ Traction speed: 2.9 m / min Film thickness: 80μm Pre-treatment of granules: Hot air drying at 80℃ for more than 8 hours to remove moisture. Moisture content of the granules: 349.00 ppm (Karl Fischer process, heating temperature: 220℃, endpoint drift value: below 0.1 μg / s) The results of the experiment showed that very clean sheets could be produced for each type of recycled resin.

[0156] [Extrusion lamination test using a small T-die] Equipment used: T-die extrusion sandwich laminating machine Mold width: 400mm Molding temperature: 250℃ Traction speeds of 10 m / min, 20 m / min, 25 m / min, 30 m / min, and 40 m / min were implemented respectively. Supply of white cloth: Polypropylene woven fabric Film thickness: 80μm Pre-treatment of granules: Hot air drying at 80℃ for more than 8 hours to remove moisture. Moisture content of the granules: 349.00 ppm (Karl Fischer process, heating temperature: 220℃, endpoint drift value: below 0.1 μg / s) The results of the experiment showed that, from a low traction speed of 10 m / min to a high speed of 40 m / min, very clean sheets could be produced for each type of recycled resin.

[0157] Based on the above results, it is confirmed that the flame-retardant polyolefin-reinforced curtain material of Example 1 can be used to obtain a recycled resin with high processing adaptability for sheet processing.

[0158] (Composition of the flame-retardant polyolefin-reinforced curtain material in Example 2) In the resin composition used to form the flame-retardant layer, a portion of the polyolefin resin was replaced with biomass polyethylene resin (SBC818, manufactured by Braskem). Otherwise, using the same materials and method as in Example 1, a flame-retardant polyolefin-reinforced curtain material of Example 2, comprising a flame-retardant layer, a reinforcing layer, and a printing layer, was obtained. The biomass polyethylene resin was incorporated at a rate of 10% of the total mass of the flame-retardant layer. The reinforced curtain material of Example 2, like that of Example 1, has a structure in which a printing layer is formed on both sides of a laminate containing a reinforcing layer sandwiched between two flame-retardant layers.

[0159] (Flame retardancy evaluation) For the flame-retardant polyolefin-reinforced curtain material of Example 2, fire resistance tests were conducted using the 45° microburner method and the 45° coil method as specified in the fire resistance performance test methods stipulated by the Ministry of Internal Affairs and Communications Ordinance. In the pretreatment, the reinforced curtain material was immersed in warm water at 50°C for 30 minutes. The test results using the 45° microburner method are shown in Table 8, and the test results using the 45° coil method are shown in Table 9. Furthermore, the samples used for the 45° microburner method and the samples used for the 45° coil method were different samples.

[0160] As shown in Tables 8 and 9, the flame-retardant polyolefin-reinforced curtain material of Example 2 was confirmed to exhibit good fire resistance. Therefore, it was confirmed that sufficient flame retardancy can be obtained even when the polyolefin resin contains biomass resin.

[0161] (Recycling Adaptability Evaluation) The flame-retardant polyolefin-reinforced curtain material of Example 2 was recycled using a small-scale re-granulator (Nippon Yugi) at a processing temperature of 210°C to obtain recycled resin. For the recycled resin, the medium-rebound ratio (MFR) was measured according to ISO 1133, with the temperature set at 230°C and the load at 2.16 kg. The MFR of the recycled resin was 21.25 g / 10 min. Therefore, it was confirmed that a recycled resin with high processing adaptability can be obtained from the reinforced curtain material of Example 2.

[0162] As described in the above embodiments and examples, the following effects can be obtained from the flame-retardant polyolefin-reinforced curtain material 10.

[0163] (1) The MFR of the recycled resin of the flame-retardant polyolefin-based reinforced curtain material 10 is more than 10 g / 10 min and less than 50 g / 10 min. Therefore, the recycled resin can be well adapted to injection molding and extrusion molding.

[0164] (2) The mass ratio of the materials contained in the flame-retardant layer 11 is: 40% to 80% polyolefin resin, 10% to 20% bromine compound, and 3% to 20% white pigment. With this composition, the flame retardancy of the flame-retardant layer 11 can be ensured, and the concealment based on the white pigment can be appropriately obtained. In addition, the recycled resin of the reinforcing curtain material 10 is easy to obtain with good physical properties.

[0165] (3) The flame retardant layer 11 is composed of a resin composition having an MFR of 8 g / 10 min or more and 30 g / 10 min or less. With this composition, the resin composition has high adaptability to T-die extrusion molding. By forming the flame retardant layer 11 using T-die extrusion molding, the flame retardant layer 11 can be made thinner, and as a result, the weight reduction of the reinforced curtain material 10 can be achieved.

[0166] (4) If the thickness of the flame retardant layer 11 is more than 30 μm and less than 200 μm, the lightweighting of the reinforced curtain material 10 can be achieved.

[0167] (5) The dry heat dimensional change rate of the polyolefin fibers constituting the reinforcing layer 12 at 150°C is in the range of -5% to -50%. As a result, the reinforcing layer 12 undergoes thermal shrinkage during ignition, which moves the reinforced curtain material 10 away from the fire source and enables the self-extinguishing of the afterflame of the molten part.

[0168] (6) The flame-retardant layer 11 is composed of a resin composition having a lower MFR than the resin constituting the polyolefin fibers of the reinforcing layer 12. Furthermore, the flame-retardant layer 11 is composed of a resin composition having a lower flexural modulus than the resin constituting the polyolefin fibers of the reinforcing layer 12. With this configuration, the reinforcing function of the reinforcing layer 12 can be reliably ensured, and the resin of the flame-retardant layer 11 compensates for the physical properties of the resin of the reinforcing layer 12. As a result, deviations in the characteristics of the recycled resin in the reinforcing curtain material 10 can be suppressed, and high-quality recycled resin can be obtained.

[0169] (7) If the reinforcing layer 12 is sandwiched between two flame-retardant layers 11, the strength is increased compared to the case of a two-layer structure. Furthermore, since the rigidity of the reinforcing curtain material 10 is also increased, the processing of the reinforcing curtain material 10 in printing processes and the like becomes easier. In addition, the reinforcing curtain material 10 is less prone to warping.

[0170] (8) If the flame-retardant layer 11 is sandwiched between two reinforcing layers 12, the strength is increased compared to the two-layer structure. Furthermore, since the rigidity of the reinforced curtain material 10 is also increased, processing of the reinforced curtain material 10 in printing processes becomes easier. In addition, since the unique texture of the fabric is reflected in the appearance of the reinforced curtain material 10, the aesthetic design of the reinforced curtain material 10 can be improved. Furthermore, wrinkles on the surface of the reinforced curtain material 10 can be suppressed.

[0171] (9) By having a printable surface, the reinforced curtain material 10 can be appropriately used as a decorative material.

[0172] (10) If the polyolefin fibers of the reinforcing layer 12 contain pigments, the concealment can be improved by the reinforcing layer 12, and the printing can be suppressed when the surface of the reinforced curtain material 10 is printed. Therefore, the reinforced curtain material 10 can be used appropriately as a decorative material.

[0173] Explanation of reference numerals in the attached figures 10, 10A, 10B, 10C Flame-retardant polyolefin reinforced curtain wall materials 11 Flame-retardant layer 12 Reinforcing Layers 13 Printing substrate

Claims

1. A flame-retardant polyolefin-based reinforcing screen material having a flame-retardant layer containing a polyolefin-based resin and a flame retardant, and a reinforcing layer composed of a polyolefin-based fiber, wherein, a melt flow rate at 230°C under a load of 2.16 kg of a recycled resin obtained by subjecting the reinforcing screen material to a material recycling treatment is 10 g / 10 min or more and 50 g / 10 min or less.

2. The flame-retardant polyolefin-based reinforcing screen material according to claim 1, wherein, the flame-retardant layer contains a bromine-based compound and a white pigment as the flame retardant, a mass ratio of the materials contained in the flame-retardant layer is: the polyolefin-based resin is 40% or more and 80% or less, the bromine-based compound is 10% or more and 20% or less, and the white pigment is 3% or more and 20% or less.

3. The flame-retardant polyolefin-based reinforcing screen material according to claim 1, wherein, the flame-retardant layer is composed of a resin composition having a melt flow rate at 230°C under a load of 2.16 kg of 8 g / 10 min or more and 30 g / 10 min or less.

4. The flame-retardant polyolefin-based reinforcing screen material according to claim 1, wherein, a thickness of the flame-retardant layer is 30 μm or more and 200 μm or less.

5. The flame-retardant polyolefin-based reinforcing screen material according to claim 1, wherein, a dry heat dimensional change rate at 150°C of the polyolefin-based fiber is in a range of -5% to -50%.

6. The flame-retardant polyolefin-based reinforcing screen material according to claim 1, wherein, the flame-retardant layer is composed of a resin composition having a melt flow rate smaller than a resin composing the polyolefin-based fiber.

7. The flame-retardant polyolefin-based reinforcing screen material according to claim 1, wherein, the flame-retardant layer is composed of a resin composition having a flexural modulus of elasticity smaller than a resin composing the polyolefin-based fiber.

8. The flame-retardant polyolefin-based reinforcing screen material according to claim 1, having one reinforcing layer and two flame-retardant layers sandwiching the reinforcing layer.

9. The flame-retardant polyolefin-based reinforcing screen material according to claim 1, having one flame-retardant layer and two reinforcing layers sandwiching the flame-retardant layer.

10. The flame-retardant polyolefin-based reinforcing screen material according to claim 1, wherein, the reinforcing screen material has a surface capable of being printed.

11. The flame-retardant polyolefin-based reinforcing screen material according to claim 10, wherein, the polyolefin-based fiber contains a pigment.

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