JP6714373B2 - Manufacturing method of laminated sheet for vehicle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a vehicle laminated sheet including a long sheet in which a backing fabric layer is formed on the back surface of a buffer layer.

Conventionally, a skin material that covers the surface of a seat cushion of a vehicle is created by pasting a skin layer on the surface of a laminated sheet in which a back base cloth layer is formed on the back surface of a cushioning layer made of foam, and then sewing. ing. The back base fabric layer is provided for improving slipperiness for improving the work at the time of sewing and the work at the time of mounting on the seat cushion after sewing, and for protecting the back surface of the buffer layer.

As the skin layer attached to the surface of the buffer layer, genuine leather or synthetic leather may be used in order to enhance the texture and feel of the skin material.
Genuine leather and synthetic leather are limited in usable size and range, unlike fabrics and the like that are continuously and uniformly produced. Therefore, when using genuine leather or synthetic leather as the skin layer, first, a laminated sheet having a back base fabric layer attached to the back surface of the buffer layer is manufactured, and a laminated sheet having a predetermined size is formed by punching or the like, After that, a skin layer made of genuine leather or synthetic leather is attached to the surface of the laminated sheet.

In addition, a laminated sheet having a surface layer made of genuine leather or synthetic leather stuck on the surface of the cushioning layer made of foam and the backing cloth layer is frame laminated (flame-welded). Since the adhesive surface with the backing base layer is heated and melted by a high temperature flame, the manufactured laminated sheet is apt to warp or shrink, and the subsequent adhesion of the skin layer cannot be performed well or the skin layer is stuck. It may cause problems with the subsequent skin material. Therefore, the laminated sheet on which the surface layer made of genuine leather or synthetic leather is attached on the surface is one in which the back base fabric layer is attached to the back side of the buffer layer made of foam with an emulsion adhesive. There is.

However, if an emulsion adhesive is used for adhering the buffer layer made of the foam and the backing cloth layer, there is a problem in that productivity is deteriorated because a drying step of the adhesive is required. Furthermore, when a coarse material such as tricot is used as the back base fabric layer, when the laminated sheets are stacked after bonding, the insufficiently dried emulsion adhesive exudes from the back base fabric layer and the laminated sheets are separated from each other. May cause blocking to adhere. In order to prevent the blocking, it is necessary to reduce the amount of the emulsion adhesive used and increase the drying time. However, when the amount of the emulsion adhesive used is reduced, the adhesive strength between the buffer layer and the backing fabric layer is reduced, while when the drying time is lengthened, the productivity is further reduced.

JP, 2003-113569, A JP 2012-217801 A

The present invention has been made in view of the above points, and has a high adhesive strength between a buffer layer and a backing cloth layer, and is free from warpage and shrinkage, and provides a method for producing a vehicle laminated sheet with good productivity. To aim.

The invention of claim 1 is a method for producing a laminated sheet for a vehicle, in which a backing fabric layer is laminated via an adhesive on a buffer layer made of a soft polyurethane foam having open cells, wherein the buffer layer is a long sheet. Is rewound and conveyed, the reaction type hot melt adhesive in a molten state is extruded on the conveyed buffer layer in a high temperature and high pressure state, and is sprayed and laminated in a filament shape, and then the backing base layer is sprayed and laminated in the filament shape. A laminated sheet for vehicles consisting of a long continuous sheet is manufactured by laminating and pressurizing on the adhered adhesive, and curing the adhesive during the conveying , and the reactive hot melt melt adhesive is a polyurethane reactive type. The composition is a hot melt and is a composition containing a crystalline polyester polyol having a melting point of 45° C. or higher.

According to the present invention, the buffer layer and the backing cloth layer are bonded together by the reactive hot melt adhesive to form the vehicle laminated sheet, so that unlike the frame laminate bonding, the laminated sheet has no warp or shrinkage. In addition, unlike the emulsion-based adhesive, there is no problem due to the seepage of the adhesive, the adhesive strength between the buffer layer and the backing base layer is high, and a laminated sheet for vehicles with good productivity can be obtained.

It is a sectional view of a laminated sheet for vehicles of one embodiment of the present invention. It is a figure which shows an example of the manufacturing method of the laminated sheet for vehicles. It is a perspective view of an example of a spray application device. It is a disassembled perspective view of the spray coating device of FIG.

A vehicle laminated sheet 10 according to an embodiment of the present invention shown in FIG. 1 will be described. The vehicle laminated sheet 10 is used as a part of a component of a skin material that covers the surface of a vehicle seat cushion, and includes a cushioning layer 11 and a back base cloth layer 21 attached to the back surface thereof. It is a long sheet. After the vehicle laminated sheet 10 is formed into a predetermined shape, a skin layer 41 made of genuine leather or synthetic leather is attached to the surface of the buffer layer 11 with a solvent-based adhesive or the like to form a skin material. After that, it is sewn into a shape that covers the cushion.

The buffer layer 11 imparts cushioning property to the skin material, and in order to ensure air permeability, a soft polyurethane foam having open cells is suitable. The thickness of the buffer layer 11 varies depending on the material of the surface skin layer 41 attached to the front surface and the back base cloth layer 21 attached to the back surface, and the like, but is, for example, about 2.0 to 15 mm.

The back base fabric layer 21 is provided to enhance the slipperiness of the back surface of the skin material and to protect the back surface of the buffer layer 11 and the like. The backing base layer 21 is preferably a non-woven fabric, a woven fabric or a knitted fabric. Especially when used as the backing cloth layer 21, tricot is particularly elastic and stretchable among the knitted fabrics, so that when the seat cushion is covered with the skin material, the tricot is easily deformed along the cushion surface, and wrinkles are formed on the skin material surface. It can be hard to occur. Examples of the material when the back base fabric layer 21 is tricot include nylon and polyester, and examples of the material when the back base fabric layer 21 is nonwoven fabric include nylon and polyester.

The backing base layer 21 is attached to the back surface of the buffer layer 11 with a reactive hot melt adhesive.
The reactive hot-melt adhesive has a urethane prepolymer as a main component and is also referred to as a moisture-curable urethane hot-melt adhesive. The reactive hot melt adhesive is obtained by reacting a polyester polyol with an isocyanate compound and has an isocyanate group (NCO) at the terminal. Particularly, those having a terminal NCO% of 1 to 3% are preferable. Examples of the polyester polyol include aliphatic carboxylic acids such as malonic acid, succinic acid and adipic acid, aromatic carboxylic acids such as phthalic acid, and aliphatic glycols such as ethylene glycol, diethylene glycol and propylene glycol. The polyester polyol obtained by condensation can be mentioned. The polyester polyol is preferably composed of a dicarboxylic acid having 6 or more carbon atoms (adipic acid, sebacic acid, etc.), and further, a crystalline ester polyol having a melting point of 45° C. or higher in an amount of 80% by weight or more as a polyol component. It is more preferable to use. The glycol constituting the polyester polyol may be an alcohol having 4 or more carbon atoms (1,4-butanediol, 1,6-hexanediol, etc.). As the isocyanate compound, aromatic isocyanate is preferable, and diphenylmethane diisocyanate (MDI) is particularly preferable.
The reactive hot-melt adhesive contains additives such as tackifier, wax, crystal nucleating agent and antioxidant, if necessary.

The reactive hot melt adhesive is applied to the back surface of the buffer layer 11 by spray application. As the spray application, a curtain spray method is particularly preferable in which the adhesive is discharged from a plurality of nozzles arranged in a line in a heated and pressurized state, sprayed while being spun into a filament shape, and laminated. The curtain spray method is a method in which a filamentous molten resin is spun by a high-temperature and high-speed air stream, stretched, and directly sprayed on a skin material to be laminated.

In order to easily and favorably perform the spray coating, the reactive hot melt adhesive is a solid at room temperature, and is in a molten state in the range of 100 to 160°C, and has a melt viscosity of 140°C ( It is preferably JIS K 6862) of 5 to 15 Pa·s. The room temperature solid means a solid at 20°C. Furthermore, the adhesive is preferably a urethane prepolymer containing a crystalline ester polyol, and the crystalline polyester polyol has (1) a room temperature solid and a melting point of 45° C. or higher, (2) The solidification time at room temperature after melt coating is preferably 1 to 5 minutes. That is, in order to apply the adhesive to a long sheet while being rewound and to quickly dry and cure the adhesive in a predetermined equipment length at room temperature, the adhesive contains a crystalline ester polyol and the urethane prepolymer has an NCO content of 1 to 1. It is 3% and the number average molecular weight is preferably 1000 to 4000, and more preferably 1500 to 2500.

If the melting temperature of the reactive hot-melt adhesive is too high, the sprayability will deteriorate, resulting in poor appearance. If the viscosity of the reactive hot melt adhesive is too low, it tends to drip when applied to the back surface of the buffer layer 11 and easily exudes from the backing base fabric layer 21. On the other hand, if the viscosity of the reactive hot melt adhesive is too high, it becomes impossible to uniformly apply the spray to the back surface of the buffer layer 11 and the back base cloth layer 21 is likely to be stuck poorly. ..

An embodiment of a method for continuously manufacturing the vehicle laminated sheet 10 will be described with reference to the apparatus shown in FIG.
The buffer layer 11 is unwound from the buffer layer roll 11A on which the buffer layer 11 of a long sheet is wound, and continuously supplied onto the conveyor 51. The transfer conveyor 51 transfers the buffer layer 11 forward at a predetermined speed, for example, a transfer speed of 30 to 50 m/min. The upper surface of the buffer layer 11 transported by the transport conveyor 51 constitutes the back surface.

A spray coating device 52 is provided above the transfer conveyor 51. In the spray coating device 52, the nozzle is provided downward, and the reactive hot melt adhesive 31 in a molten state supplied from the reactive hot melt adhesive accommodating tank 70 is supplied to the upper surface of the buffer layer 11 on the conveyor 51. Apply by curtain spray method. The coating amount for the buffer layer 11 is, for example, 10 to 30 g/m ² .

An example of the spray coating device 52 for coating by the curtain spray method will be described with reference to FIGS. 3 and 4.
In the spray coating device 52, a pair of base plates 522 and 523 are fixed to the lower surface of a support plate 521. A base 524 is formed on the base plates 522 and 523, and an adhesive supply port 525 and air supply ports 526 and 527 are formed on the facing surface of the base 524. The support plate 521 and the mouth plate 522, 523 have a plurality of adhesive injection holes 528 communicating with the adhesive supply port 525 and a plurality of air introducing holes 529, 530 communicating with the air supply ports 526, 527. Are formed. A nozzle plate 531 is arranged between the facing surfaces of the base 524. A plurality of nozzle grooves 532 are formed in the nozzle plate 531 at predetermined intervals so as to correspond to the adhesive supply port 525 and the air supply ports 526 and 527. The nozzle groove 532 is formed vertically with a groove width of about 0.4 mm.

In the spray coating device 52, the molten adhesive contained in the adhesive container 70 is pressure-fed, discharged from the nozzle groove 532 having a plurality of small holes arranged in a line, and stretched by a high-temperature high-pressure air stream. A layer of the reactive hot melt adhesive 31 is formed on the upper surface of the buffer layer 11 by being blown into a filament shape and laminated while being stretched.

After the reactive hot melt adhesive 31 is applied by spraying, from the back base cloth layer roll 21A in which the back base cloth layer 21 is wound on the upper surface of the buffer layer 11 coated with the reactive hot melt adhesive 31. The back base cloth layer 21 is rewound and laminated, and is passed between the pressure bonding rollers 53 and 54. Then, while being conveyed by the plurality of rollers 57 to 64 over a predetermined time, the reaction type hot melt adhesive 31 is reacted and cured, and the back surface layer of the buffer layer 11 is coated with the reaction type hot melt adhesive 31. The laminated sheet 10 for vehicles which consists of a long continuous sheet which stuck 21 is formed, and it winds up with the winding roll 10A. The time from the spray application to the winding of the vehicle laminated sheet 10, that is, the solidification time of the reactive hot melt adhesive 31 is, for example, 1 to 5 minutes.

In the present invention, the backing cloth layer 21 is bonded to the buffer layer 11 by a reactive hot melt adhesive. However, as another embodiment, the buffer layer 11 has a skin layer as a reactive hot melt adhesive. It may be joined by.

Examples 1 to 3 shown in Table 1 were manufactured by the apparatus shown in FIG. As the buffer layer 11, a soft urethane foam sheet having a thickness of 5 mm, product number: EL-45, manufactured by Inoac Corporation was used. The transport speed of the transport conveyor 51 was 40 m/min, the reactive hot melt adhesive 31 was in a molten state, and was spray-coated on the upper surface of the buffer layer 11 by the spray coating device 52 together with hot air at 130° C.

The reactive hot melt adhesive 31 of Example 1 has a terminal NCO of 1.8%, an isocyanate of MDI, an acid component of polyester polyol of adipic acid, a glycol component of butanediol, and a melt viscosity of 7 Pa·s (140° C.). ).
The reactive hot melt adhesive 31 of Example 1 is solid at room temperature and is formed from crystalline polyester polyol having a melting point of 45° C. or higher.
The reactive hot melt adhesive 31 of Example 2 is 1.8% in terminal NCO, MDI in isocyanate, sebacic acid in acid component of polyester polyol, and hexanediol in glycol component, is solid at room temperature, and has melt viscosity of 6 Pa. -S (140°C).
The reactive hot melt adhesive 31 of Example 3 is 1.4% in terminal NCO, MDI in isocyanate, adipic acid in acid component of polyester polyol, butanediol in glycol component, is solid at room temperature, and has melt viscosity of 15 Pa.・There is s (140°C).
The solidification time is 3 min in Example 1, 1 min in Example 2, and 3 min in Example 3.

In addition, Comparative Examples 1 to 3 shown in Table 1 were manufactured using the same buffer layer 11 and back base fabric layer 21 as in Examples 1 to 3.
In Comparative Example 1, as the reactive hot melt adhesive 31, the terminal NCO is 1.4%, the isocyanate is MDI, the acid component of the polyester polyol is succinic acid, the glycol component is ethylene glycol, and the melt viscosity is 7 Pa·s (140° C.). A liquid at room temperature (20° C.) and amorphous were used. The solidification time is 20 min.
In Comparative Example 2, water-based EVA was applied as an adhesive by a roll coater using the apparatus shown in FIG. 2 (excluding the spray coating apparatus 52 and a drying step further added).
In Comparative Example 3, the buffer layer and the backing cloth layer were adhered by frame lamination.

The sprayability of the adhesive used in Examples 1 to 3 and Comparative Example 1, blocking in the laminated sheets of Examples 1 to 3 and Comparative Examples 1 to 3, appearance, peel strength, productivity, warpage, and shrinkage were evaluated, A comprehensive judgment was made. The results are shown in Table 2.

The method of evaluating sprayability is as follows, when the adhesive of Examples 1 to 3 and Comparative Example 1 is applied to a PET film by using the spray coating device 52, the presence or absence of lumps of φ3 mm or more in a 300 mm square is determined as follows. Confirmed by the standard. The evaluation of sprayability was performed only for the adhesives of Examples 1 to 3 and Comparative Example 1.
⊚: 2 or less lumps, ◯: 3 to 5 lumps, ×: more than 5 lumps.

As a blocking evaluation method, the laminated sheets of Examples 1 to 3 and Comparative Examples 1 to 3 were wound at the time of production, and then rewound after 24 hours, and the presence or absence of sticking of the laminated sheets was confirmed.
◎: Can be rewound without peeling sound when rewinding, ○: Can be rewound although peeling sound occurs when rewinding, ×: Sticking and rewinding are impossible.

As for the appearance evaluation method, presence or absence of lumps of φ3 mm or more was confirmed in a 300 mm square range on the surface of the backing base fabric layer in the laminated sheets of Examples 1 to 3 and Comparative Examples 1 to 3.
⊚: 2 or less lumps, ◯: 3 to 5 lumps, ×: 5 or more lumps.

The evaluation method of the peeling strength was such that the laminated sheets of Examples 1 to 3 and Comparative Examples 1 to 3 were allowed to stand for 24 hours in an environment of 25° C., and then a T-type peeling test was carried out according to JIS K 6854-3. evaluated. The peel strength was evaluated according to the following criteria.
⊚: Peel strength value of 2 N/25 mm or more, ◯: Peel strength value of 1 to 2 N/25 mm, ×: Peel strength value of 1 N/25 mm or less.

As for the productivity evaluation method, whether or not production is possible according to the transport speed of the transport conveyor 51 is determined by the production line speed. The production line speed according to the present invention and the frame laminate can be 30 m/min or more, whereas the water-based EVA bonding method requires a drying step, and therefore it is required to be 10 m/min or less.
⊚: 30 m/min or more, ◯: 10 to 30 m/min, x: 10 m/min or less.

The warpage evaluation method was as follows. The laminated sheets of Examples 1 to 3 and Comparative Examples 1 to 3 wound at the time of production were cut at a length of 1 m in the winding direction, and a test body was allowed to stand on a flat surface. After 7, 14, 21, and 28 days, the height at which the edge of the test piece turned up was measured and evaluated.
⊚: Height of turning up is 10 mm or less, ◯: Height of turning up is 10 to 20 mm, ×: Height of turning up is 20 mm or more.

The evaluation method of shrinkage was 0, 7, 14, 21, with respect to the test body obtained by cutting the laminated sheets of Examples 1 to 3 and Comparative Examples 1 to 3 wound at the time of manufacture in a length of 1 m in the winding direction. The length and width dimensions of the test piece after 28 days were measured, and the shrinkage ratio with respect to the dimension on day 0 was calculated as the average value of the length and width.
⊚: Shrinkage is 1% or less, ◯: Shrinkage is 1 to 5%, ×: Shrinkage is 5% or more.

The overall evaluation was made on all evaluation items. ⊚: All evaluation items are “⊚”, ◯: There is one or more evaluation items with “◯”, and there is no evaluation item with “x”, x: There is one or more evaluation items with “x”.

As shown in Table 2, in Examples 1 to 3, all of the evaluation items were “⊚” or “◯” or higher, and the overall judgment was also “⊚” or “◯”. On the other hand, Comparative Example 1 in which the adhesive is a room temperature liquid reactive hot melt adhesive has blocking “×”, and Comparative Example 2 in which the adhesive is water-based EVA has blocking and productivity “×”, and is of frame laminate type. In Comparative Example 3, warpage and shrinkage were [x], and in Comparative Examples 1 to 3, the overall judgment was "x".

As described above, the vehicle laminated sheet and the manufacturing method of the present invention are different from the adhesion by the frame laminate, and the vehicle laminated sheet made of the long sheet has no warp or shrinkage, and the adhesive sheet is made of an adhesive such as an emulsion adhesive. It does not cause problems due to bleeding, has a high adhesive strength between the buffer layer and the backing cloth layer, and has good productivity.

10 Vehicle laminated sheet 11 Buffer layer 21 Back base fabric layer

Claims (1)

In a method for producing a laminated sheet for a vehicle in which a backing fabric layer is laminated via an adhesive to a buffer layer made of a flexible polyurethane foam having open cells,
The buffer layer of the long sheet is unwound and conveyed, and the reaction type hot melt adhesive in a molten state is extruded in a high temperature and high pressure state on the conveyed buffer layer, sprayed in a filament shape and laminated, and then the backing base fabric. A layer is laminated on the adhesive which is sprayed and laminated in the form of filaments, pressure is applied, and a vehicular laminated sheet consisting of a long continuous sheet is produced by reacting and curing the adhesive during the transportation ,
The method for producing a laminated sheet for vehicles, wherein the reactive hot melt melt adhesive is a polyurethane reactive hot melt and is a composition containing a crystalline polyester polyol having a melting point of 45° C. or higher .

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