Method for manufacturing attached article for automobile interior

Abstract

To provide a method for manufacturing an attached article for automobile interior which can secure sufficient product quality when an attached article for automobile interior is manufactured using a one-pack aqueous adhesive.SOLUTION: A method for manufacturing an attached article for automobile interior includes: a coating step of coating a one-pack aqueous adhesive AD onto an adhesive coated surface RP1 of release paper RP; and a drying step of drying the one-pack aqueous adhesive AD coated onto the adhesive coated surface RP1 in a drying furnace 3. The drying furnace 3 has a conveyance path 35 of the release paper RP, and blowers 33A and 33B for blowing hot air to the adhesive coated surface RP1 of the release paper RP to be conveyed. Conveyance speed of the release paper RP in the conveyance path 35 is set to be lower than speed when release paper coated with a solvent type adhesive is conveyed through the conveyance path 35. The hot air temperature set by the blowers 33A and 33B is set to be higher than the hot air temperature blown by the blowers 33A and 33B when the solvent type adhesive is dried.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing an attachment item for automobile interiors using a one-component water-based pressure sensitive adhesive. [Background technology]

[0002] Conventionally, the method of applying liquid adhesives has been known to be the solvent-based method, in which the adhesive is dissolved in an organic solvent. Solvent-based adhesives have been widely used because they are easy to mix with a wide variety of additives and tend to exhibit high performance. However, in consideration of environmental friendliness, there is a movement to shift to the emulsion method, in which adhesives are emulsified in an aqueous medium instead of dissolved in an organic solvent.

[0003] For example, Patent Document 1 proposes an aqueous pressure-sensitive adhesive composition composed of a base polymer containing a tackifier resin emulsion. Patent Document 1 shows that the aqueous pressure-sensitive adhesive composition contains a tackifier resin emulsion, and thereby the aqueous pressure-sensitive adhesive composition has excellent moisture-resistant adhesion and heat resistance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-126546 A Summary of the Invention [Problem to be solved by the invention]

[0005] The applicant of the present application has investigated the production of an adhesive article for automobile interiors using a one-component water-based adhesive containing a large amount of solids.

[0006] However, the above-mentioned one-component water-based adhesive does not contain a solvent, so there is a problem that the adhesive layer becomes hard because the volatile component is small and the solid content is large. Therefore, even if an automobile interior application product using a one-component water-based adhesive is manufactured using the same manufacturing method as an automobile interior application product using a conventional solvent-based adhesive, it is difficult to ensure the same product quality.

[0007] Therefore, an object of the present invention is to provide a method for producing an automobile interior application article that can ensure sufficient product quality when producing an automobile interior application article using a one-component water-based pressure sensitive adhesive. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a method for manufacturing an adhesive for automotive interiors, the method comprising: a coating step of coating a one-component water-based adhesive onto an adhesive-coated surface of a release paper; and a drying step of drying the aqueous adhesive coated on the adhesive-coated surface in the coating step in a drying oven, the drying oven having a transport path for transporting the release paper, and an air blowing section for blowing hot air onto the adhesive-coated surface of the release paper transported via the transport path, the transport speed of the release paper on the transport path being set slower than the transport speed when the release paper coated with a solvent-based adhesive is transported via the transport path, and the temperature of the hot air blown by the air blowing section is set higher than the temperature of the hot air blown by the air blowing section when drying the solvent-based adhesive.

[0009] Here, it is preferable to further include a bonding step in which, after the drying step, the adhesive-coated surface and the back surface of the skin are passed through a pair of heat rollers while being in surface contact with each other, thereby bonding the back surface of the skin to the adhesive-coated surface.

[0010] It is preferable that the method further includes a humidifying step of humidifying the surface of the release paper opposite to the adhesive-coated surface after the drying step and before the pressure-bonding step.

[0011] Furthermore, it is preferable that the water-based adhesive is continuously stirred in a state stored in an adhesive storage tank prior to the coating step. Effect of the Invention

[0012] According to the manufacturing method of the automobile interior application product of the present invention, the one-component aqueous adhesive applied to the adhesive-coated surface of the release paper in the application step is dried in a drying oven. The drying oven has a conveying path for conveying the release paper and an air blowing section for blowing hot air to the adhesive-coated surface of the release paper conveyed through the conveying path. The conveying speed of the release paper in the conveying path is set slower than the conveying speed when the release paper coated with the solvent-based adhesive is conveyed through the conveying path. The temperature of the hot air blown by the air blowing section is set higher than the temperature of the hot air blown by the air blowing section when drying the solvent-based adhesive. This allows the surface layer to be reliably pressed against the release paper using the one-component aqueous adhesive. Therefore, it is possible to ensure sufficient product quality when manufacturing an automobile interior application product using the one-component aqueous adhesive.

[0013] Incidentally, the above-mentioned Patent Document 1 does not disclose at all any specific configuration for ensuring sufficient product quality in the production of automobile interior application items using a one-component water-based pressure sensitive adhesive. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing a production line for implementing a method for producing an automobile interior application item according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing a drying oven including a heat source and a blower. [Diagram 3] FIG. 4 is a graph showing the conveying speed of the release paper and the temperature of the heat source in a drying furnace. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] <1. Embodiment> A manufacturing method of an automobile interior application article according to an embodiment of the present invention will be described with reference to Figures 1 to 3. In the following, a manufacturing line 1 shown in Figure 1 will be exemplified as a manufacturing line for realizing a manufacturing method of an automobile interior application article using a one-component water-based adhesive AD. Note that one-component water-based adhesive AD refers to an adhesive that does not contain a solvent, has a relatively high solids concentration (about 52% in this embodiment), and has the property of easily solidifying.

[0016] The manufacturing line 1 manufactures automotive interior application products through five main processes. Specifically, the manufacturing line 1 manufactures automotive interior application products through a coating process, a drying process, a humidifying process, a pressing process, and a cutting process.

[0017] As shown in Fig. 1, the production line 1 is configured to include an adhesive applicator 2, a drying furnace 3, a humidifier 4, a pressing machine 5, and a cutting machine 6. Although not shown, the production line 1 also includes a conveying means (conveying rollers, etc.) for conveying the release paper RP. In the manufacturing process of the automobile interior application item, the release paper RP is conveyed by the conveying means at a constant speed from the upstream side to the downstream side in the conveying direction DR.

[0018] The adhesive applicator 2 is a device for carrying out a coating process in which a one-component water-based adhesive AD is applied to an adhesive coating surface RP1 (the upper surface when the release paper RP is transported) of the release paper RP. Specifically, the adhesive applicator 2 is configured with an adhesive storage pool 21 that stores the one-component water-based adhesive AD, and a pair of coating rollers 23A, 23B that coat the one-component water-based adhesive AD stored in the adhesive storage pool 21 onto the adhesive coating surface RP1 of the release paper RP.

[0019] The adhesive storage pool 21 is provided integrally with the pair of application rollers 23A, 23B on the upstream side in the conveying direction DR of the release paper RP. The one-component water-based adhesive AD stored in the adhesive storage pool 21 is continuously stirred by an agitator (not shown). In other words, the one-component water-based adhesive AD before being applied to the adhesive application surface RP1 of the release paper RP is continuously stirred in the adhesive storage pool 21.

[0020] The pair of application rollers 23A, 23B rotate in a predetermined direction to transport the release paper RP in a transport direction DR, while applying the one-component water-based adhesive AD supplied from the adhesive storage pool 21 onto the adhesive application surface RP1 of the release paper RP.

[0021] The pair of application rollers 23A, 23B are arranged so that a gap of a predetermined width is formed between the upper application roller 23A and the lower application roller 23B. The relative positioning of the pair of application rollers 23A, 23B is adjustable, and the gap can be narrowed by moving the two rollers closer to each other, or widened by moving them farther apart.

[0022] The one-component water-based adhesive AD is successively supplied from the adhesive storage pool 21 and applied to the adhesive-coated surface RP1 of the release paper RP through the gap between the pair of application rollers 23A, 23B. The amount of one-component water-based adhesive AD applied to the adhesive-coated surface RP1 of the release paper RP is adjusted by the size of the gap between the pair of application rollers 23A, 23B.

[0023] The drying oven 3 is a drying oven that performs a drying step of drying the one-component water-based adhesive AD applied by the adhesive applicator 2 to the adhesive application surface RP1 of the release paper RP.

[0024] As shown in FIG. 2, the drying furnace 3 includes heat sources 31A and 31B, fans 33A and 33B, and a transport path .

[0025] Heat sources 31A and 31B are heaters that generate heat at a set temperature. Fans 33A and 33B are provided next to heat sources 31A and 31B, respectively. Fans 33A and 33B blow the heat generated by heat sources 31A and 31B as hot air to transport path 35. Although not shown in the figures, the hot air blown from fans 33A and 33B is actually supplied to transport path 35 from 40 outlets via separate ducts.

[0026] 3, when a one-component aqueous adhesive AD is used as the adhesive, the conveying speed of the release paper RP in the conveying path 35 is set to 10 m / min. The set temperatures of the heat sources 31A and 31B, i.e., the temperature of the hot air blown by the fans 33A and 33B, are set to 100° C.

[0027] That is, when the one-component water-based adhesive AD is used as the adhesive, the conveying speed (10 m / min) of the release paper RP on the conveying path 35 is slower than the conveying speed (15 m / min) when the release paper RP coated with a conventional solvent-based adhesive is conveyed through the conveying path 35. In other words, when the one-component water-based adhesive AD is used as the adhesive, the release paper RP is conveyed through the conveying path 35 at a slower speed than when a conventional solvent-based adhesive is used.

[0028] In addition, when one-component water-based adhesive AD is used as the adhesive, the temperature of the hot air (100°C) blown by the fans 33A and 33B is higher than the temperature of the hot air (70°C) blown by the fans 33A and 33B when drying a conventional solvent-based adhesive.

[0029] In this way, when the one-component water-based adhesive AD is used as the adhesive, the release paper coated with the one-component water-based adhesive AD is transported in the drying furnace 3 at a slower speed than before, while the one-component water-based adhesive AD is dried with hot air at a higher temperature than before.

[0030] The humidifier 4 is a device that performs a humidification process to humidify the surface of the release paper RP opposite to the adhesive-coated surface RP1 (the lower surface when the release paper RP is transported). The release paper RP contains moisture because it is made from pulp. When it passes through the drying furnace 3, the moisture content of the release paper RP decreases. Therefore, by humidifying the surface of the release paper RP opposite to the adhesive-coated surface RP1, the moisture content of the release paper RP is increased by about 2%.

[0031] The pressing machine 5 is a device that performs a pressing process in which the back surface of the skin SK (processing material) is pressed against the adhesive-coated surface RP1 of the release paper RP. Specifically, the pressing machine 5 is configured with a pair of heat rollers 51A, 51B. The adhesive-coated surface RP1 of the release paper RP and the back surface of the skin SK are brought into surface contact with each other and passed through the pair of heat rollers 51A, 51B, whereby the back surface of the skin SK is pressed against the adhesive-coated surface RP1.

[0032] The cutter 6 is a device that performs a cutting process in which the release paper RP with the back surface of the skin SK pressed against it is cut to a predetermined width.

[0033] According to the above-mentioned embodiment, the one-component water-based adhesive AD applied to the adhesive-coated surface RP1 of the release paper RP in the application step is dried in the drying furnace 3. The drying furnace 3 has a conveying path 35 for conveying the release paper RP, and air blowers 33A, 33B for blowing hot air to the adhesive-coated surface RP1 of the release paper RP conveyed through the conveying path 35. The conveying speed (10 m / min) of the release paper RP in the conveying path 35 is set slower than the conveying speed (15 m / min) when the release paper RP coated with the solvent-based adhesive is conveyed through the conveying path 35. The temperature of the hot air (100°C) blown by the air blowers 33A, 33B is set higher than the temperature of the hot air (70°C) blown by the air blowers 33A, 33B when drying the solvent-based adhesive. This allows the surface layer to be reliably pressure-bonded to the release paper RP using the one-component water-based adhesive AD. Therefore, when using the one-component water-based pressure sensitive adhesive AD to manufacture automotive interior application products, it is possible to ensure sufficient product quality.

[0034] However, since the one-component water-based adhesive AD does not contain a curing agent (heat-resistant material) like the two-component water-based adhesive, there are concerns about the heat resistance of the automobile interior application product using the one-component water-based adhesive AD. In this regard, in the above-mentioned embodiment, the temperature of the hot air blown by the blowers 33A and 33B is set to 100°C, and drying is performed at a temperature equivalent to the heat resistance specification of the parts in the automobile where it is used (doors, pillars, roof, etc.). Therefore, even if the inside of the automobile becomes hot, the one-component water-based adhesive AD is unlikely to deteriorate, such as softening or carbonization.

[0035] Furthermore, according to the embodiment described above, warm air is blown by the air blowers 33A and 33B onto the adhesive-coated surface RP1 of the release paper RP, so uneven drying is less likely to occur compared to when room temperature air is blown using an electric fan.

[0036] According to the embodiment described above, in the pressing step, the adhesive-coated surface RP1 of the release paper RP and the back surface of the skin SK are passed through a pair of heat rollers 51A, 51B in a state of surface contact with each other. Therefore, it is possible to more reliably press the back surface of the skin SK against the adhesive-coated surface RP1 compared to the case of passing through a pair of rollers that do not have a heating function.

[0037] Furthermore, according to the embodiment described above, in the humidifying step, the surface of the release paper RP opposite the adhesive-coated surface RP1 is humidified by the humidifier 4. Therefore, the moisture content of the release paper RP, which has been significantly reduced in the heating step, is restored, and deformation of the release paper RP can be suppressed.

[0038] Furthermore, according to the above-described embodiment, the one-component water-based adhesive AD stored in the adhesive storage pool 21 is continuously stirred by the stirrer. The one-component water-based adhesive AD has a high solid content concentration of approximately 52%, and therefore has the tendency to harden easily. Therefore, it is possible to prevent the one-component water-based adhesive AD from hardening before being applied to the adhesive application surface RP1 of the release paper RP.

[0039] <2. Modifications> The method for producing an automobile interior application item according to the present invention is not limited to the above-described embodiment, and various modifications and improvements are possible within the scope of the claims.

[0040] For example, in the above-described embodiment, the temperature of the heat source is constant at 100° C. regardless of the material of the skin, but the present invention is not limited to this. The temperature of the heat source may be set individually depending on the material of the skin (e.g., fabric, synthetic leather, urethane, etc.).

[0041] In the above embodiment, the surface of the release paper opposite to the adhesive-coated surface is moistened in the moistening step, but the present invention is not limited to this. Depending on the dryness of the release paper after the drying step, moistening in the moistening step may be omitted. [Explanation of symbols]

[0042] 1 Production Line 2. Adhesive applicator 3 Drying oven 4 Humidifier 5 Crimping machine 6 cutting machine 21 Adhesive Storage Pool 23A, 23B Application roller 31A,31B Heat source 33A,33B Blower 35 Transport Path 51A, 51B Heat roller DR Transport direction RP Release Paper RP1 Adhesive coated surface SK epidermis

Claims

1. A method for producing an automobile interior application product, comprising the steps of: A coating step of coating a one-component water-based adhesive on an adhesive-coated surface of the release paper; a drying step of drying the one-component aqueous adhesive applied to the adhesive-applied surface in the application step in a drying oven; Equipped with The drying oven has a conveying path for conveying the release paper, and a blowing unit that blows hot air onto the adhesive-coated surface of the release paper conveyed through the conveying path, a conveying speed of the release paper in the conveying path is set to be slower than a conveying speed of a release paper coated with a solvent-based adhesive conveyed through the conveying path, A method for manufacturing an adhesive item for automobile interiors, characterized in that the temperature of the hot air blown by the air blowing section is set higher than the temperature of the hot air blown by the air blowing section when drying the solvent-based adhesive.

2. 2. The method for manufacturing an adhesive item for automotive interiors according to claim 1, further comprising a bonding step of passing the adhesive-coated surface and the back surface of the skin in surface contact with each other through a pair of heat rollers after the drying step, thereby bonding the back surface of the skin to the adhesive-coated surface.

3. 3. The method for manufacturing an automobile interior application item according to claim 2, further comprising a humidifying step of humidifying a surface of the release paper opposite to the adhesive application surface thereof after the drying step and before the pressing step.

4. 4. The method for producing an automobile interior application item according to claim 1, wherein the one-component water-based adhesive is continuously stirred in a state stored in an adhesive storage tank prior to the coating step.

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