JP2005307004A - Sheet for tonneau cover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a sheet for a tonneau cover, which uses neither an antimony composition nor an organophosphorus compound, provides flame retardance passing flame-retardant standards for vehicles by a nitrogen-based flame retardant, is soft and has excellent roll-like winding properties. <P>SOLUTION: The sheet for a tonneau cover comprises a flame-retardant synthetic resin sheet mainly composed of 100 parts by mass of a mixture of 10-70 mass % of a copolyamide resin having 100-180°C melting point and 90-30 mass % of a urethane-based thermoplastic elastomer and 20-80 parts by mass of a nitrogen-based flame retardant. The sheet for a tonneau cover is obtained by laminating a knitted or woven fabric to at least one side of the flame-retardant synthetic resin sheet. The sheet for tonneau cover is obtained by laminating the flame-retardant synthetic resin sheets to both sides of a knitted or woven fabric. Preferably the nitrogen-based flame retardant is a mixture of melamine cyanurate and hydrazodicarbonamide. Preferably the flame-retardant synthetic resin sheet is a sheet by calender molding. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet used for a tonneau cover of an automobile interior material.

  Cargo rooms such as wagon-type cars are provided with partition sheets for blindfolding luggage stored in the cargo room. This partition sheet is called a tonneau cover and is installed in a winding type. Therefore, the tonneau cover is required to be relatively thin, easy to roll up and rewind, not to be bulky when rolled up, and to meet strength and flame retardant standards for vehicles. Sex is required.

Conventionally, the material of the tonneau cover was generally soft polyvinyl chloride, but an alternative to soft polyvinyl chloride has been proposed for environmental measures. The present applicant has previously proposed that synthetic resin leather, in which a mixed resin layer of a thermoplastic urethane resin and an acrylic soft resin is provided on at least one side of a knitted fabric, is used for a tonneau cover (Patent Document 1). Vehicle interior materials are required to be flame retardant to pass vehicle flame retardant standards. Conventionally, antimony compound-based flame retardants such as antimony oxide and organic phosphorus compound-based flame retardants such as phosphate esters and phosphite esters However, in recent years, specifications for antimony compounds and organophosphorus compounds have been regulated.
JP 2003-155181 A

  The present invention provides a tonneau cover sheet that can impart flame retardancy that passes a flame retardant standard for a vehicle with a nitrogen-based flame retardant without using an antimony compound or an organic phosphorus compound, and is flexible and excellent in roll-up winding properties. The purpose is to do.

  The present invention mainly includes 100 parts by mass of a mixture of 10 to 70% by mass of a copolymerized polyamide resin having a melting point of 100 to 180 ° C. and 90 to 30% by mass of a urethane-based thermoplastic elastomer, and 20 to 80 parts by mass of a nitrogen-based flame retardant. A tonneau cover sheet made of a flame-retardant synthetic resin sheet. Moreover, this invention is a sheet | seat for tonneau covers formed by laminating a knitted fabric on at least one side of said flame-retardant synthetic resin sheet. Furthermore, this invention is a sheet | seat for tonneau covers formed by laminating | stacking said flame-retardant synthetic resin sheet on both surfaces of a knitted fabric. The nitrogen-based flame retardant is preferably a mixture of melamine cyanurate and hydrazodicarbonamide. The flame-retardant synthetic resin sheet is preferably a calendered sheet.

  The tonneau cover sheet of the present invention has flame retardancy that passes the flame retardant standard for vehicles with the incorporation of a nitrogen-based flame retardant, even if an antimony compound or an organic phosphorus compound is not blended. Moreover, it is flexible and has excellent roll-up properties.

The copolymerized polyamide resin used in the present invention has a melting point of 100 to 180 ° C. The polyamide resin is produced by polycondensation of a dibasic acid HOOC (CH ₂ ) _n COOH and a diamine NH ₂ (CH ₂ ) _n NH ₂ . In this polycondensation, a copolymerized polyamide resin can be produced by using two or more dibasic acids as raw materials or using two or more diamines as raw materials. The polyamide resin can also be produced by polycondensation or polymerization of ω-amino acid HOOC (CH ₂ ) _n NH ₂ or lactam. In this polycondensation or polymerization, a copolymerized polyamide resin can be produced by using two or more ω-amino acids or lactams as raw materials. And by selecting a copolymer component, copolymer polyamide resins having various melting points can be produced. In the above formula, n is an integer.

  As the copolymer component, an aliphatic compound is preferable to an aromatic compound because a copolymerized polyamide resin having a lower softening temperature can be obtained. Further, it is preferable to use a copolymer having a carboxylic acid group and an amino group at both ends of a long-chain aliphatic hydrocarbon such as ω-lauramide as a copolymer component, and a copolymer component that minimizes crystallinity and its component A melting point of 100 to 180 ° C. can be obtained by selecting a copolymerization ratio and carrying out random polymerization. For example, nylon 6 has a melting point of about 225 ° C. and nylon 66 has a melting point of about 265 ° C., whereas nylon 6 and nylon 66 in a ratio of 50:50 copolymer nylon (copolymer polyamide) has a melting point of about 135 ° C. is there.

  The urethane-based thermoplastic elastomer (TPU) used in the present invention can be obtained by reacting a diisocyanate compound with a compound having two or more hydroxyl groups, and is composed of a long-chain polyol, a diisocyanate, and a chain extender. A polyurethane-based thermoplastic elastomer composed of so-called soft segments and hard segments can be preferably used. These preferably have a Shore A hardness of 65 to 90 resin hardness, particularly 70 to 80 resin hardness. In addition, the Shore A hardness in this invention is the value (measurement temperature 23 degreeC) measured by ASTMD2240.

  Diisocyanate compounds for the synthesis of urethane thermoplastic elastomers include tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated dicyclohexylmethane diisocyanate, isophorone diisocyanate. Isoianate and the like are used.

  Examples of the compound having two or more hydroxyl groups include polyester polyols which are condensation reaction products of dibasic acids such as adipic acid and phthalic acid and glycols such as ethylene glycol and 1,4-butanediol; ethylene carbonate and the like Polycarbonate polyol which is a reaction product of carbonate and glycol; polyether polyol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol-polypropylene glycol, etc. are used. Examples of chain extenders include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butane 1,2 diol, butane 1,3 diol, butane 1,4 diol, butane 2,3 diol, hexane diol, and the like. The low molecular weight polyhydric alcohol, diamine, or water is used.

  The urethane thermoplastic elastomer used in the present invention preferably has a softening point in the range of 60 to 120 ° C. If it is less than 60 ° C., for example, in the case of calendar molding, it tends to adhere to the roll surface, which is not preferable. Examples of urethane-based thermoplastic elastomers include T-8375N and T-1180N manufactured by DCI Bayer Polymer, P-22SRNAT and P-25MRNAT manufactured by Nippon Polyurethane, and P manufactured by Dainichi Seika Kogyo Co., Ltd. -2283, BASF Japan 1180A-10, etc. are mentioned.

  The tonneau cover sheet is required to have flexibility, strength, and flame retardancy so that roll winding and rewinding can be performed smoothly. Polyamide resin has good flame retardancy but high hardness. The present invention secures flexibility and flame retardancy by combining a copolymerized polyamide resin having a melting point of 100 to 180 ° C. and a urethane-based thermoplastic elastomer. In order to keep the tonneau cover sheet flexible so that winding and rewinding can be performed smoothly, it is necessary to blend 30 mass% or more of a urethane-based thermoplastic elastomer. Moreover, when the mixing ratio of the copolymer nylon is 10% by mass or less, it becomes difficult to obtain flame retardancy that passes the flame retardant standard for vehicles even if a nitrogen-based flame retardant is blended. Therefore, in the present invention, the mixing ratio is 10 to 70% by mass of a copolymerized polyamide resin having a melting point of 100 to 180 ° C. and 90 to 30% by mass of a urethane-based thermoplastic elastomer.

  The sheet having the above mixing ratio has flexibility preferable for the tonneau cover, but is inferior in flame retardancy. Therefore, in the present invention, a nitrogen-based flame retardant is blended in order to impart flame retardancy to this mixture. The nitrogen-based flame retardant is blended in an amount of 20 to 80% by mass with respect to 100 parts by mass of the mixture of the copolymerized polyamide resin and the urethane-based thermoplastic elastomer. Since the nitrogen-based flame retardant is familiar with the copolymerized nylon and the urethane-based thermoplastic elastomer, the tonneau cover sheet can be manufactured satisfactorily. Nitrogen-based flame retardants include melamine cyanurate, mono (β-cyanoethyl) isocyanurate, bis (β-cyanoethyl) isocyanurate, tris (β-cyanoethyl) isocyanurate, hydrazodicarbonamide, dicyandiamide and the like. A mixture of melamine cyanurate and hydrazodicarbonamide is preferred. When a mixture of melamine cyanurate and hydrazodicarbonamide is used, a mixture of 95 to 50% by mass of melamine cyanurate and 5 to 50% by mass of hydrazodicarbonamide is preferable.

  Resin mainly comprising 100 parts by mass of a mixture of 10 to 70% by mass of a copolymerized polyamide resin having a melting point of 100 to 180 ° C. and 90 to 30% by mass of a urethane-based thermoplastic elastomer and 20 to 80 parts by mass of a nitrogen-based flame retardant. The composition may contain a soft resin containing an oxygen atom such as an ethylene-vinyl acetate copolymer or an ethylene- (meth) acrylate copolymer, if necessary. These components are blended and mixed well using a blender such as a ribbon blender or a hexchel mixer, then kneaded with a Banbury mixer or continuous kneader, and further kneaded with a mixing roll, warming roll and strainer, A sheet for tonneau cover is manufactured by forming into a sheet shape with a calendar rolled by a calendar roll. Moreover, you may shape | mold into a sheet form by T-die shaping | molding which puts into an extruder after said mixing and extrudes from T-die. Moreover, it can also shape | mold into a sheet form with other existing molding machines, such as inflation molding.

  In the case of calendering, a lubricant is used to adjust the adhesion to the roll. Examples of the lubricant include aliphatic metal salts of stearic acid such as calcium, magnesium, zinc, and barium, polyethylene wax, stearic acid, alkylenebisfatty acid amide, montanic acid, montanic acid partially saponified ester, and montanic acid ester. Particularly preferred lubricants are montanic acid, montanic acid partially saponified ester, and montanic acid ester. The lubricant is preferably blended in an amount of 0.1 to 1.5 parts by weight with respect to 100 parts by weight of the resin mixture. The calendering temperature is preferably 120 ° C to 180 ° C. When the temperature is 120 ° C. or lower, the thermoplastic urethane resin is not softened, and a sheet having a uniform appearance cannot be obtained. If it is 180 ° C. or higher, the adhesiveness becomes high and the workability deteriorates. Moreover, in this invention, it is preferable to mix | blend calcium carbonate 5-30 mass parts with respect to 100 weight part of resin mixtures. Thereby, calendar workability improves. If it is 5% by mass or less, calender workability is not improved, and if it is 30% by mass or more, the strength of the tape is lowered and the wear resistance is lowered.

  If necessary, the resin mixture may further contain an ultraviolet absorber, a light stabilizer, a pigment, an antibacterial agent and the like that are usually used for blending synthetic resins. As the ultraviolet absorber, a benzotriazole-based ultraviolet absorber such as 2- (2'-hydroxy-5'-methylphenyl) benzotriazole is used. As the light stabilizer, hindered amine light stabilizers such as bis- (2,2,6,6-tetramethyl-4-piperidyl) sebacate are used. As the antibacterial agent, a silver-based inorganic antibacterial agent or the like is used.

  The molded flame retardant synthetic resin sheet can be used as it is for a tonneau cover. A knitted fabric may be laminated on at least one side of the sheet to form a tonneau cover sheet. Further, the above flame-retardant synthetic resin sheet may be laminated on both sides of the knitted fabric to form a tonneau cover sheet. As the knitted fabric, a woven fabric, a knitted fabric or a non-woven fabric is used. The materials of these knitted fabrics are polyamide fiber, polyester fiber, acrylic fiber, polypropylene fiber, cotton, rayon, and blended yarns thereof. Examples of the knitted fabric include a double-sided knitted fabric and a tentacle knitted fabric. Examples of the woven fabric include a plain woven fabric, a twill woven fabric, and a satin woven fabric.

  Lamination of the flame retardant synthetic resin sheet and the knitted fabric is performed by adhesion. For bonding, a two-component polyurethane adhesive or the like is used. This adhesive may be applied to the flame retardant synthetic resin sheet surface or the knitted fabric surface. When a flame-retardant synthetic resin sheet is laminated on both sides of a knitted fabric, a coarse fabric may be used as the knitted fabric to make a tarpaulin.

Examples 1-4 and Comparative Examples 1-3
Ingredients shown in Table 1 were mixed at a ratio in a ribbon blender and kneaded with a Banbury mixer. Further, the kneaded material was kneaded with a mixing roll, a warming roll, and a strainer, and the kneaded product was rolled with an inverted L-type calendar (set temperature: 150 to 160 ° C.) to obtain a sheet having a thickness of 0.25 mm.
In Table 1, the thermoplastic polyurethane elastomer is “T-8375” (hardness: Shore A80) manufactured by DCI Bayer Polymer. The copolymer nylon is “CM-6541X3” (ε-caproamide / ω-lauramide copolymer: melting point 133 ° C.) manufactured by Toray Industries, Inc. The montanic acid ester lubricant is “LICOWAX OP” manufactured by Clariant Japan.

  An acrylic resin-based gloss adjusting agent was applied to one side of the obtained sheet. A urethane-based adhesive was applied to the other surface, a polyester fabric (30th spun yarn, 27 × 27 stitches / inch) was laminated, and embossing was performed to produce a tonneau cover sheet. The tonneau cover sheet was evaluated for flame retardancy and texture (flexibility). The combustion test was based on JIS D1201 (1998). The texture was evaluated by touch and winding properties. The results are also shown in Table 1. Regarding flame retardancy, a burning rate of 100 mm / min or less is a necessary condition as a vehicle interior material in the above test method, and it is more preferable that it is self-extinguishing.

Claims (5)

  Flame retardancy mainly composed of 100 parts by mass of a mixture of 10 to 70% by mass of a copolymerized polyamide resin having a melting point of 100 to 180 ° C. and 90 to 30% by mass of a urethane-based thermoplastic elastomer and 20 to 80 parts by mass of a nitrogen-based flame retardant. Tonneau cover sheet made of synthetic resin sheet.   A tonneau cover sheet comprising a knitted fabric laminated on at least one side of the flame-retardant synthetic resin sheet according to claim 1.   A sheet for a tonneau cover obtained by laminating the flame-retardant synthetic resin sheet according to claim 1 on both sides of a knitted fabric.   The sheet for tonneau covers according to any one of claims 1 to 3, wherein the nitrogen-based flame retardant is a mixture of melamine cyanurate and hydrazodicarbonamide. The tonneau cover sheet according to any one of claims 1 to 4, wherein the flame-retardant synthetic resin sheet is a calendered sheet.