Composite cloth for convertible top of convertible and preparation method thereof

Abstract

The present application relates to a kind of composite cloth for soft top of open roof car and its preparation method, it is characterized in that: the composite cloth includes outer surface, bonding layer, intermediate layer, bonding layer, inner surface in turn from outside to inside, the intermediate layer is thermoplastic elastomer, the thermoplastic elastomer raw material includes the following mass parts of component: thermoplastic resin 40-60 parts, elastomer 25-50 parts, foaming agent 0.5-2 parts, flame-retardant master batch 8-25 parts, antibacterial powder 1-5 parts, coupling agent 1-3 parts, crosslinking agent 0.5-1 part;Wherein, antibacterial powder is the compound of far infrared ceramic powder and silver ion antibacterial powder;Flame-retardant master batch is the compound of phosphorus-nitrogen composite halogen-free flame retardant, golds rare earth flame-retardant synergist and microcapsule coated red phosphorus.The composite cloth for soft top of open roof car of the present application is foldable, aging-resistant, with excellent flame-retardant, mildew-proof, formaldehyde removal performance.

Description

Technical Field

[0001] The invention belongs to the technical field of multi-layer hot-melt composites, and in particular relates to a composite fabric for a convertible car soft top and a preparation method thereof. Background Art

[0002] Convertibles can be divided into hardtops and softtops based on their roof structure. Softtops are more common, usually made of canvas, vinyl, or PVC leather, and equipped with foldable brackets that allow the roof to be folded open and closed.

[0003] However, the convertible car soft top made of the simple materials mentioned above has poor flame retardancy, poor aging resistance, insufficient softness, and a short service life. In addition, when folded and stored after rain or humidity, the ordinary cloth surface is prone to mold and mildew, resulting in visible mold spots, which cannot meet consumers' requirements for the various performance of convertible car soft top materials.

[0004] During the car assembly or subsequent decoration process, colloid adhesives containing a large amount of formaldehyde are also used in the soft top of convertible cars. Formaldehyde has a relatively strong irritating effect on human skin and mucous membranes. Long-term inhalation of formaldehyde can lead to the occurrence of cancers such as leukemia.

[0005] Chinese patent CN202210262874.9 discloses a convertible soft top composite material and a preparation method thereof. The convertible soft top composite material includes an outer surface, an intermediate layer, and an inner surface; the outer surface is one of a woven fabric, an imitation leather material, and a genuine leather material; the raw material component of the intermediate layer is butyl rubber or halogenated butyl rubber; the inner surface is one of a woven fabric, an imitation leather material, and a genuine leather material; the convertible soft top composite material has excellent waterproof and weather resistance, bonding performance, air tightness, sound insulation effect, light aging resistance, and chemical resistance, but its softness, mildew resistance, and flame retardancy are poor. Summary of the Invention

[0006] The present invention aims to provide a composite fabric for a convertible car soft top and a preparation method thereof. The composite fabric is resistant to bending and aging and has excellent flame retardancy, mildew resistance and formaldehyde removal properties.

[0007] The technical solution adopted by the present invention to solve the above-mentioned problem is: a composite fabric for a convertible car soft top, the composite fabric comprising, from the outside to the inside, an outer facing, an adhesive layer, an intermediate layer, an adhesive layer, and an inner facing, the intermediate layer being a thermoplastic elastomer, and the raw material of the thermoplastic elastomer comprising the following components in parts by weight:

[0008] 40-60 parts of thermoplastic resin,

[0009] 25-50 parts of elastomer

[0010] 0.5-2 parts of foaming agent

[0011] Flame retardant masterbatch 8-25 parts

[0012] 1-5 parts antibacterial powder

[0013] 1-3 parts coupling agent

[0014] 0.5-1 part crosslinking agent

[0015] The flame retardant masterbatch is a compound of a phosphorus-nitrogen composite halogen-free flame retardant, a lanthanum-based rare earth flame retardant synergist, and microcapsule-coated red phosphorus.

[0016] Preferably, the outer surface is one of woven fabric, imitation leather material, and genuine leather material; the inner surface is one of woven fabric, imitation leather material, and genuine leather material; the outer surface and the inner surface are both treated with waterproof silicon and UV level 4 treatment.

[0017] Preferably, the thermoplastic resin is a polyolefin thermoplastic elastomer TPO, and the PP resin in the raw material is a ternary copolymer PP, which and EPDM act as base resins, and are a blend with PP as a hard segment and EPDM as a soft segment.

[0018] Preferably, the elastomer is composed of ethylene propylene diene monomer (EPDM) and styrene-butadiene-styrene (SEBS) block copolymer; the elastomer SBS has excellent room temperature impact strength and low temperature impact strength for PP, and SEBS, as a hydrogenated product of SBS, makes the temperature resistance and aging resistance even better, and when EPDM and SEBS are used together to toughen PP, there is a significant synergistic effect, and the toughening effect is significantly better than that of a single EPDM or SEBS.

[0019] Preferably, the foaming agent is a core-shell structure foaming agent, wherein the shell is a thermoplastic acrylic polymer and the core is spherical plastic particles composed of alkane gas, which can effectively reduce the weight of the product, produce a uniform and stable closed microporous structure, and play a role in heat insulation.

[0020] Preferably, the antibacterial powder is a combination of far-infrared ceramic powder and silver ion antibacterial powder. The far-infrared ceramic powder emits more far-infrared rays than normal objects and has a catalytic oxidation function. Under sunlight (especially ultraviolet light), it generates monovalent hydroxide ions, effectively removing benzene, formaldehyde, sulfide, ammonia, and odorous substances indoors, while also having a bactericidal effect. The metal ions in the silver ion antibacterial powder react with bacteria, destroying the microorganism's inherent components or causing functional impairment. Once the bacteria lose activity, the metal ions are released and continue to perform their bactericidal activity, resulting in a long-lasting antibacterial effect. Furthermore, under the influence of light, the metal ions act as catalytic active centers, activating oxygen in water and air to generate hydroxyl radicals and reactive oxygen ions. The reactive oxygen ions have strong oxidizing power, quickly destroying bacterial reproduction and causing cell death, thereby achieving the antibacterial effect.

[0021] Preferably, the coupling agent is a powder coupling agent, which has active and polar groups and combines the properties of multiple processing aids such as dispersion, coupling, internal and external lubrication. Compared with general liquid coupling agents, it has good performance and durability and does not precipitate.

[0022] Preferably, the flame retardant masterbatch is prepared by the following preparation method: a phosphorus-nitrogen composite halogen-free flame retardant, a Jinshilan rare earth flame retardant and microcapsule-coated red phosphorus (microencapsulated red phosphorus) in a mass ratio of 7:1:2 are fully mixed in a high-speed mixer at room temperature.

[0023] Preferably, the composite fabric for the convertible car soft top has a thickness of 0.8-2 mm.

[0024] A method for preparing a composite fabric for a convertible car soft top comprises the following steps:

[0025] Step 1: Put the thermoplastic elastomer raw materials into a kneader according to the ratio and knead them. During the kneading process, the temperature of the kneader is kept constant. After the raw materials are evenly dispersed, they are conveyed to a twin-screw granulator using a single screw for granulation. After drying, thermoplastic elastomer particles are obtained.

[0026] Step 2: The thermoplastic elastomer particles obtained in step 1 are formed into a thermoplastic elastomer sheet using a calendering laminating machine under high temperature conditions, and both sides of the thermoplastic elastomer sheet are hot-melt-bonded to the outer surface and the inner surface via an adhesive layer formed by a hot-melt adhesive film of a high-temperature resistant release film to obtain a composite cloth;

[0027] Step three, baking the composite cloth obtained in step two at a high temperature to heat-seal and reinforce the composite cloth, and then cooling and shaping the composite cloth to obtain a finished product.

[0028] Preferably, the kneading temperature in step 1 is 130-140°C, the kneading time is 10-20 min, and the temperature of the twin-screw granulator is 150-160°C; the high temperature in step 2 is 130-150°C, and the thickness of the thermoplastic elastomer sheet is 0.3 mm-0.8 mm; the high temperature baking temperature in step 3 is 180-200°C, and the baking time is 1-2 min.

[0029] During the kneading process, the temperature of the kneader should be kept constant at 130-140°C. If the temperature is too high, the thermoplastic resin, elastomer and cross-linking agent will cross-link prematurely, and the dispersion effect in the twin-screw granulator will deteriorate in the next process. In addition, if the temperature is too high, reaching 180-200°C, the foaming agent will also react and foam, making it impossible to smoothly calender the sheet.

[0030] When calendered into sheets, the surface of the thermoplastic elastomer produced has a certain degree of stickiness, and is soft and elastic. It is clamped with a hot-melt adhesive film lined with a high-temperature resistant release film to maintain the size of the sheet without direct contact with the machine's rollers. While peeling off the two layers of high-temperature resistant release film, it is hot-melt bonded to the exterior and interior surfaces that have been treated with waterproof silicone and UV level 4. It then passes through an oven at 180-200 degrees Celsius, controlling the production speed to ensure that the composite cloth stays in the oven for 1-2 minutes. If the time is too short, the foaming will be incomplete, and if the time is too long, the foaming will be over-excessive, which will lead to foam rupture.

[0031] Compared with the prior art, the advantages of the present invention are:

[0032] The composite fabric for the convertible car soft top is resistant to bending and aging and has excellent flame retardancy, mildew resistance and formaldehyde removal properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a process flow chart of the composite cloth for convertible car soft top.

[0034] Among them: 1 and 2 are hot melt adhesive films for high temperature resistant release films, 3 is the winding route for peeling off the high temperature resistant release film, 4 is the unwinding route for the exterior surface, 5 is the winding route for peeling off the high temperature resistant release film, and 6 is the unwinding route for the interior surface.

[0035] Figure 2 This is a schematic structural diagram of the composite fabric for a convertible car soft top according to the present invention. DETAILED DESCRIPTION

[0036] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0037] A method for preparing a composite fabric for a convertible car soft top comprises the following steps:

[0038] Step 1: Put the thermoplastic elastomer raw materials into a kneader according to the ratio and knead them. The kneader is kept at a constant temperature of 135°C. After kneading for 15 minutes, the raw materials are evenly dispersed and conveyed to a twin-screw granulator using a single screw for granulation. After drying, thermoplastic elastomer particles are obtained. The temperature of the twin-screw granulator is 150°C.

[0039] Step 2: The thermoplastic elastomer particles obtained in step 1 are formed into a thermoplastic elastomer sheet using a calendering laminating machine at a temperature of 140°C. The thermoplastic elastomer sheet has a thickness of 0.5 mm. Both sides of the thermoplastic elastomer sheet are sandwiched with hot melt adhesive films with high-temperature resistant release films. While the two layers of high-temperature resistant release films are peeled off, the outer surface (woven fabric with waterproof treatment) and the inner surface (woven fabric with waterproof treatment) are hot melt bonded to the two sides of the thermoplastic elastomer sheet to obtain a composite fabric.

[0040] Step 3: bake the composite cloth obtained in step 2 at 200°C for 2 minutes to heat-seal and reinforce the composite cloth, and then cool and shape it to obtain the finished product.

[0041] The mass proportions of the raw materials in Examples 1-5 are shown in Table 1.

[0042] Among them, the thermoplastic resin is British INEOS KV329; the elastomer is a compound of SEBS YH-688 (Yueyang Petrochemical) and EPDM311PM (Sinopec), with a mass ratio of 1:1; the foaming agent is Guangdong Benqi NS-1530C; the antibacterial powder is silver ion antibacterial powder KF136 (Huizhou Mingkai) and 1250 mesh far-infrared ceramic powder (Tianjin Hongyan), with a mass ratio of 3:2; the coupling agent is Guangzhou Yuantai YY5021; the cross-linking agent is Jiangsu Huaxing TAIC.

[0043] The flame retardant masterbatch is prepared by the following preparation method:

[0044] (1) Preparation of phosphorus-nitrogen composite halogen-free flame retardant: Phosphorus-based flame retardant (phosphate ester) and nitrogen-based flame retardant (melamine) are stirred and mixed evenly in a mass ratio of 1:1. Water is added during the mixing process to ensure uniform mixing. After mixing, the powdered phosphorus-nitrogen composite halogen-free flame retardant is obtained by spray drying.

[0045] (2) The nitrogen-phosphorus compound flame retardant, the Jinshilan rare earth flame retardant synergist, and the microcapsule-coated red phosphorus with a mass ratio of 7:1:2 were fully mixed in a high-speed mixer at room temperature.

[0046] Table 1:

[0047]

[0048] Comparative Example 1:

[0049] The only difference between Comparative Example 1 and Example 1 is that the thermoplastic resin used is injection molding grade Sinopec Maoming HT9025M.

[0050] Comparative Example 2:

[0051] The only difference between Comparative Example 2 and Example 1 is that the flame retardant masterbatch used is the polypropylene halogen-free flame retardant masterbatch HB115 produced by Huabiao Plastics.

[0052] Comparative Example 3:

[0053] The only difference between Comparative Example 3 and Example 1 is that KF136 is used alone as the antibacterial powder, that is, silver ion antibacterial agents are used entirely.

[0054] Comparative Example 4:

[0055] The only difference between Comparative Example 4 and Example 1 is that the antibacterial powder is solely 1250 mesh far-infrared ceramic powder, that is, all far-infrared ceramic powder is used.

[0056] Comparative Example 5:

[0057] The only difference between Comparative Example 5 and Example 1 is that the temperature of the kneader is 160 degrees.

[0058] Comparative Example 6:

[0059] The only difference between Comparative Example 6 and Example 1 is that after being calendered into a sheet, only a high-temperature release film is used for backing, without a hot-melt adhesive film.

[0060] The composite fabrics of Examples 1-5 and Comparative Examples 1-6 were subjected to performance tests, wherein the performance test results of Examples 1-5 are shown in Table 2, and the performance test results of Comparative Examples 1-6 are shown in Table 3.

[0061] Table 2 Performance test results of Examples 1-5

[0062]

[0063] Table 2 Performance test results of comparative examples 1-5

[0064]

[0065] As can be seen from the above table, compared with Example 1, the injection molding grade PP HT9025M used in Comparative Example 1 had poor dispersion effect due to the kneading process at 135 degrees; Comparative Example 2 used Huabiao Plastic's polypropylene halogen-free flame retardant masterbatch - HB115, which had a general flame retardant effect; Comparative Example 3 used Huizhou Mingkai KF136 throughout, and Comparative Example 4 used Tianjin Hongyan 1250 mesh far-infrared ceramic powder throughout. It can be seen that the silver ion antibacterial powder and the far-infrared ceramic powder have a synergistic effect, especially in removing formaldehyde; Comparative Example 5 had excessively high kneading machine and twin-screw temperatures, resulting in uneven dispersion and foaming of the thermoplastic elastomer, leading to large fluctuations in product testing; Comparative Example 6 had no hot melt adhesive film, and the base fabric and thermoplastic elastomer sheet did not stick together, resulting in a failed trial production, and the experimental data was marked as NG.

[0066] In addition to the above embodiments, the present invention also includes other implementation methods. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the scope of protection of the claims of the present invention.

Claims

1. A composite fabric for a convertible car soft top, characterized by: The composite cloth comprises, from the outside to the inside, an outer facing, a bonding layer, an intermediate layer, a bonding layer, and an inner facing, wherein the intermediate layer is a thermoplastic elastomer, and the raw material of the thermoplastic elastomer comprises the following components in parts by weight: 40-60 parts of thermoplastic resin, 25-50 parts of elastomer 0.5-2 parts of foaming agent Flame retardant masterbatch 8-25 parts 1-5 parts antibacterial powder 1-3 parts coupling agent 0.5-1 part crosslinking agent The antibacterial powder is a compound of far-infrared ceramic powder and silver ion antibacterial powder; the flame retardant masterbatch is a compound of phosphorus-nitrogen composite halogen-free flame retardant, Jinshilanthanum rare earth flame retardant synergist and microcapsule-coated red phosphorus; the mass ratio of the phosphorus-nitrogen composite halogen-free flame retardant, Jinshilanthanum rare earth flame retardant synergist and microcapsule-coated red phosphorus is 7:1:2; The thermoplastic resin is KV329; the elastomer is composed of EPDM and SEBS; The thermoplastic elastomer is specifically a thermoplastic elastomer sheet, which is made of thermoplastic elastomer particles. The thermoplastic elastomer particles are prepared by the following preparation method: thermoplastic elastomer raw materials are placed in a kneader according to a ratio and kneaded, during which the kneader maintains a constant temperature. After the raw materials are evenly dispersed, they are conveyed to a twin-screw granulator using a single screw for granulation, and then dried to obtain thermoplastic elastomer particles, wherein the kneading temperature is 130-140°C and the kneading time is 10-20 minutes.

2. The composite fabric for a convertible car soft top according to claim 1, characterized in that: The exterior finish is one of woven fabric, imitation leather material, and genuine leather material; the interior finish is one of woven fabric, imitation leather material, and genuine leather material; the exterior finish and interior finish are both treated with waterproof silicon and UV level 4 treatment.

3. The composite fabric for a convertible car soft top according to claim 1, characterized in that: The foaming agent is a core-shell structure foaming agent, wherein the shell is a thermoplastic acrylic polymer and the core is an alkane gas.

4. The composite fabric for a convertible car soft top according to claim 1, characterized in that: The thickness of the composite fabric for the convertible car soft top is 0.8-2 mm.

5. A method for preparing a composite fabric for a convertible car soft top according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Put the thermoplastic elastomer raw materials into a kneader according to the ratio and knead them. During the kneading process, the temperature of the kneader is kept constant. After the raw materials are evenly dispersed, they are conveyed to a twin-screw granulator using a single screw for granulation. After drying, thermoplastic elastomer particles are obtained. Step 2: The thermoplastic elastomer particles obtained in step 1 are formed into a thermoplastic elastomer sheet using a calendering laminating machine under high temperature conditions. Hot melt adhesive films with high temperature resistant release films are applied to both sides of the thermoplastic elastomer sheet. The high temperature resistant release films are then peeled off, and the formed adhesive layers are successively hot melt bonded to the outer and inner surfaces to obtain a composite fabric. Step 3: baking the composite fabric obtained in step 2 at a high temperature to heat-seal and reinforce the composite fabric, and then cooling and shaping the composite fabric to obtain a finished product; The high temperature in step 2 is 130-150°C, and the high temperature baking temperature in step 3 is 180-200°C.

6. The method for preparing a composite fabric for a convertible car soft top according to claim 5, characterized in that: In step 1, the kneading temperature is 130-140°C, the kneading time is 10-20 min, and the temperature of the twin-screw granulator is 150-160°C; in step 2, the thickness of the thermoplastic elastomer sheet is 0.3 mm-0.8 mm; and in step 3, the high-temperature baking time is 1-2 min.

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