JP2007253782A - Interior article for automobile and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interior article for an automobile furnished with a skin made of inexpensive thermoplastic urethane and hard to turn yellow. <P>SOLUTION: The interior article is furnished with at least a base material and the skin 12. The skin 12 has a first skin 13 which is a cabin surface designed-skin and a second skin 14 laminated on the first skin 13. The composition of the first skin 13 is non-yellow-turn urethane. The composition of the second skin 14 is foam yellow-turn urethane. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automobile interior product including a foamed resin and a method for manufacturing the same.

An automotive interior product is configured to include at least a base material and a skin. This skin is made of powder slush. For this powder slush molding skin, it was the mainstream to use vinyl chloride material before. However, since it is environmentally friendly and resistant to environmental aging, in recent years, many skins made of thermoplastic urethane have been used (see paragraph 35 of Patent Document 1).
JP 2000-185356 A

  However, since urethane usually turns yellow due to sunlight, when used as the skin of automobile interior parts, yellow aromatics such as MDI and TDI that are prone to yellowing cannot be used. Expensive aliphatic isocyanates such as hydrogenated MDI must be used. As a result, the powder slush molding skin is about 3 to 5 times more expensive than the previous vinyl chloride, and there is a problem that such non-yellowing urethane can only be used in advanced models. is there.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an interior product for an automobile using a cheap thermoplastic urethane and having a skin that does not easily yellow, or a method for producing the same. There is to do.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  The present invention is an automotive interior comprising at least a base material and an outer skin, and has a first skin that is a vehicle interior surface design skin, and a second skin laminated on the first skin. The first skin composition is non-yellowing urethane, and the second skin composition is foamed yellow urethane.

  According to said structure, since the composition of a 1st skin is a non-yellowing urethane, a vehicle interior surface design skin does not yellow with sunlight. On the other hand, since the composition of the 2nd skin laminated | stacked on this 1st skin is a non-yellowing urethane, the required thickness for skin molding can be ensured using an inexpensive material. In addition, the thickness unevenness of the second skin that occurs when the second skin is laminated on the first skin is alleviated by foaming of the second skin, and the occurrence of thickness unevenness of the entire skin is suppressed.

  Moreover, the isocyanate which comprises the said non-yellowing urethane in this invention may be one chosen from aliphatic isocyanate or alicyclic isocyanate. According to this structure, the yellowing by sunlight of a vehicle interior surface design skin can be prevented reliably.

  In addition, the present invention provides an automobile interior having at least a base material and a skin, the skin having a first skin that is a vehicle compartment surface design skin, and a second skin laminated on the first skin. In the method, a non-yellowing thermoplastic polyurethane powder obtained by polymerizing an isocyanate selected from an aliphatic isocyanate or an alicyclic isocyanate and a polyol in a solvent is charged into a heated mold and heat-sealed. A first step of forming the first skin having a predetermined thickness, and a yellowing thermoplastic polyurethane powder obtained by polymerizing aromatic isocyanate and polyol in a solvent and then adding and mixing a foaming agent, A second step of forming the second skin having a predetermined thickness by being put into the formed mold and heat-sealing; and by reheating the mold, the first skin and And a third step of foaming the foaming agent of the second skin with melt molding the second skin.

  In the above method, in the powder slush molding method, after adding non-yellowing thermoplastic polyurethane powder to the same heated mold, subsequently adding yellowing thermoplastic polyurethane powder mixed with additives. In the mold, two layers of a first skin composed of non-yellowing urethane and a second skin composed of yellowed urethane are formed in a state containing powder in a semi-molten state. Therefore, it is possible to form two layers by simply performing powder adhesion to the mold twice. Also, in order to cause the second skin to foam at the same time when reheating to completely melt the semi-molten powder, the first and second skins can be melted without any special process for foaming. In addition, the second skin can be foamed. Thereby, the lamination | stacking of the 1st skin and 2nd skin by a powder slush molding method can be obtained, without raising a shaping | molding cost.

  Next, embodiments of the invention will be described. FIG. 1 is a partial cross-sectional view of an automobile interior product according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view for particularly showing the structure of the epidermis.

(Composition of automobile interior parts)
As shown in FIG. 1, an automotive interior part 1 is used as an interior part such as an instrument panel, a door trim, or a ceiling material, and is formed by integrally forming a skin 12 on a base material 11. ing. An automobile shown in the drawing is provided by mounting a pre-formed skin 12 on one of a pair of molds for molding an interior product, and injecting a resin forming a base material into a cavity formed on the opposite side of the skin 12. Interior product 1 is obtained. The automobile interior part 1 may be an automobile interior part having a three-layer structure in which a foam layer is formed between the base material 11 and the skin 12. In this case, a pre-formed skin 12 is attached to one of a pair of molds for molding an interior product, and a pre-formed base material 11 is attached to the other metal mold. By injecting the foamed resin into the cavity formed between the two, a three-layer automobile interior part 1 is obtained.

  For the base material 11, a general-purpose resin such as PP (polypropylene) is used. The skin 12 is formed by powder slush molding so as to have a thickness of about 0.9 to 1.2 mm, and is laminated on the first skin 13 which is a casing surface design skin, and is laminated on the first skin 13. 2nd skin 14 which was made.

  The first skin 13 has a non-yellowing urethane formed in a thickness of about 0.4 to 0.5 mm as a composition. The isocyanate constituting the yellowed urethane of the first skin 13 is one selected from aliphatic isocyanate or alicyclic isocyanate. These isocyanates are referred to as “non-yellowing polyisocyanates”, and are a general term for polyisocyanates that do not have a resonance structure such as a benzene ring or a naphthalene ring in the molecular skeleton. The non-yellowing polyisocyanate is preferably selected from uretdione-modified products, isocyanurate-modified products, allophanate-modified products, biuret-modified products derived from non-yellowing organic diisocyanates, such as adhesive strength and durability. In view of the above, polyisocyanates selected from isocyanurate-modified products, allophanate-modified products, and biuret-modified products derived from non-yellowing organic diisocyanates are particularly preferred. Non-yellowing urethane may be added with various known additives and auxiliaries such as antioxidants, UV absorbers, flame retardants, plasticizers, pigments / dyes, antibacterial agents / antifungal agents, etc. May be.

  On the other hand, as shown in FIG. 2, the 2nd skin 14 has yellowing urethane formed in the thickness of about 0.5-0.7 mm as a composition. The second skin 14 is formed by foaming yellowed urethane so that the thickness of the skin 12 does not partially become extremely thin. The reason why the skin 12 becomes partially extremely thin is that the mold for forming the slash is heated to 240 ° C. and the like, and the powder for the first skin 13 is charged. Then, due to the nature of the powder slush molding process in which the powder for the second skin 14 which is the second layer is introduced and formed, the second skin 14 is melted by the heat transmitted from the mold to the first skin 13. Therefore, in addition to the variation in the original mold temperature, the variation in the heat conduction with respect to the second skin 14 increases due to the variation in the thickness of the first skin 13.

  Foaming of yellowed urethane is performed by foaming a chemical foaming agent mixed with yellowed urethane with heat during powder slush molding. As the chemical foaming agent, azodicarbonamide, NN′-dinitrosopentamethylenetetramine, or the like can be used. The expansion ratio of the chemical foaming agent is set to 2 to 3 times. The foam 15 of the second skin 14 may be a closed cell or an open cell.

  The relationship between the material price per weight of the first skin 13 and the second skin 14 and the vinyl chloride is 4 (3 to 5) when the vinyl chloride is 1, and the non-yellowing urethane is 4 (3 to 5). Is 1.5 (1.3 to 1.7). Thereby, the skin 12 formed by the 1st skin 13 and the 2nd skin 14 is 4 material costs when the whole is formed with non-yellowing urethane, when compared with the skin formed entirely with non-yellowing urethane. However, the material cost can be reduced to 2.8.

(Method for manufacturing automobile interior parts)
In the above configuration, a method for manufacturing the automobile interior part 1 will be described. The interior 1 for automobiles is prepared by introducing a non-yellowing thermoplastic polyurethane powder obtained by polymerizing an isocyanate selected from an aliphatic isocyanate or an alicyclic isocyanate and a polyol in a solvent into a heated mold. A first step of forming a first skin having a predetermined thickness by wearing, a yellowing thermoplastic polyurethane powder obtained by polymerizing an aromatic isocyanate and a polyol in a solvent and then adding and mixing a foaming agent; A second step of forming a second skin having a predetermined thickness by being put into a mold on which the skin is formed and heat-sealing, and by reheating the mold, the first skin and the second skin are melt-molded. And a third step of foaming the foaming agent of the second skin.

(First step)
The first step includes a preheating step (FIG. 3), a first charging step (FIG. 4), and a first fusion step (FIG. 5). The first step may include the mold opening step of FIG. Specifically, as shown in FIG. 3, first, a nickel electroforming mold 21 provided on the inner surface that forms the casing surface design skin is prepared, and the inner surface of the nickel electroforming mold 21 is heated by hot air from the heating device 22. By heating, the temperature is raised to about 245 ° C. (preheating step). Then, as shown in FIG. 4, the non-yellowing thermoplastic polyurethane powder 24 for the 1st skin 13 which is the 1st layer is thrown in. That is, a first powder container 23 formed so as to be fitted to the opening surface of the nickel electroforming mold 21 is prepared, and a predetermined amount of non-yellowing thermoplastic polyurethane powder 24 is accommodated in the first powder container 23. . Then, the first powder container 23 is moved (raised) toward the opening of the nickel electroforming mold 21 and the upper surface of the first powder container 23 is fitted into the opening of the nickel electroforming mold 21 to clamp the mold. (First charging step).

  Here, as the non-yellowing thermoplastic polyurethane powder 24, HDI (hexamethylene diisocyanate) is used as an isocyanate and polymerized in a solvent with a polyether polyol. The average powder particle size is set to about 120 μm.

  Next, as shown in FIG. 5, the nickel electroforming mold 21 and the first powder container 23 are rotated in a clamped state. As a result, the non-yellowing thermoplastic polyurethane powder 24 comes into contact with the heated nickel electroforming mold 21, and the non-yellowing thermoplastic polyurethane powder 24 to which the amount of heat is transferred from the nickel electroforming mold 21 is heated and liquefied. It will be fused to the inner surface of the mold 21. Then, a first skin 13 having a predetermined thickness of about 0.4 to 0.5 mm is formed on the inner surface of the nickel electroforming mold 21 (first fusion process).

(Second step)
Next, the second step is performed. The second process includes a mold opening process (FIG. 6), a second charging process (FIG. 6), a second fusion process (FIG. 7), and a mold opening process (FIG. 8). Specifically, as shown in FIG. 6, the posture of the nickel electroforming mold 21 is set so that the first powder container 23 is positioned on the lower side, and the non-yellowing thermoplastic polyurethane powder 24 in the powder state is set to the first. By dropping and accommodating in the powder container 23, only the first skin 13 remains on the inner surface of the nickel electroforming mold 21. Then, the first powder container 23 is lowered and separated from the nickel electroforming mold 21 to perform mold opening (mold opening process).

  Thereafter, the yellowish thermoplastic polyurethane powder 27 for the second skin 14 as the second layer is introduced. That is, a second powder container 26 formed so as to be fitted to the opening surface of the nickel electroforming mold 21 is prepared, and a predetermined amount of yellowed thermoplastic polyurethane powder 27 is accommodated in the second powder container 26. Then, the second powder container 26 is moved toward the opening of the nickel electroforming mold 21, and the upper surface of the second powder container 26 is fitted to the opening of the nickel electroforming mold 21 to perform clamping ( Second charging step).

  Here, the yellowing thermoplastic polyurethane powder 27 is obtained by using MDI (diphenylmethane diisocyanate) as an isocyanate and polymerizing it in a polyether polyol and a solvent, and then chemical blowing agent (manufactured by Eiwa Kasei Kogyo: Azodicarbonamide AC9-50W). ) Can be added and mixed. The average particle diameter is set to about 140 μm.

  Next, as shown in FIG. 7, the nickel electroforming mold 21 and the second powder container 26 are rotated in a clamped state. As a result, the yellowed thermoplastic polyurethane powder 27 comes into contact with the heated first skin 13, and the yellowed thermoplastic polyurethane powder 27 to which heat is transferred from the nickel electroforming mold 21 and the first skin 13 is heated and liquefied. The first skin 13 is fused. Then, a second skin 14 having a predetermined thickness of about 0.5 to 0.7 mm is formed in a laminated state on the first skin 13 (second fusion process).

  Thereafter, as shown in FIG. 8, the posture of the nickel electroforming mold 21 is set so that the second powder container 26 is positioned on the lower side, and the yellow thermoplastic thermoplastic powder 27 in the powder state is replaced with the first powder container. The first skin 13 and the second skin 14 are left only on the inner surface of the nickel electroforming mold 21 by being dropped and housed in 23. Then, the second powder container 26 is lowered and separated from the nickel electroforming mold 21 to perform mold opening (mold opening process).

(Third step)
Next, the third step is performed. The third step includes a curing / foaming step (FIG. 9), a cooling step (FIG. 10), and a demolding step (FIG. 11). Specifically, as shown in FIG. 9, the first skin 13 and the second skin 14 are reheated with hot air from a heating device 22 to the nickel electroforming mold 21 in which the first skin 13 and the second skin 14 are fused in a laminated state, thereby By curing the skin 13 and the second skin 14 and foaming the chemical foaming agent contained in the second skin 14 to form a large number of foams 15, the second skin 14 is 0.8 to 1.6 mm. (Cure and foaming process). In addition, since a foaming process is performed simultaneously with a curing process, a foaming process does not increase in a manufacturing process as a new process.

  Next, as shown in FIG. 10, the nickel electroforming mold 21 is cooled (cooling process), and as shown in FIG. 11, the skin 12 made up of the first skin 13 and the second skin 14 is peeled off from the nickel electroforming mold 21. Thus, the epidermis 12 is formed (demolding step).

  Thereafter, as shown in FIG. 1, the skin 12 made as described above is attached to a mold for molding an interior product, and a resin that forms a base material in a cavity formed on the opposite side of the skin 12 is added. The automobile interior product 1 is manufactured by injection.

(Outline of this embodiment)
As described above, as shown in FIGS. 1 and 2, the automobile interior article 1 of the present embodiment includes at least the base material 11 and the skin 12, and the skin 12 is a vehicle interior surface design skin. The first skin 13 and the second skin 14 laminated on the first skin 13, the composition of the first skin 13 is non-yellowing urethane, and the yellowing of the composition of the second skin 14 is foamed The configuration is urethane.

  According to said structure, since the composition of the 1st skin 13 is non-yellowing urethane, a vehicle interior surface design skin does not yellow with sunlight. On the other hand, since the composition of the 2nd skin 14 laminated | stacked on this 1st skin 13 is a non-yellowing urethane, the required thickness for skin shaping | molding can be ensured using an inexpensive material. In addition, the thickness unevenness of the first skin 13 generated when the second skin 14 is laminated on the first skin 13 is alleviated by the foaming of the second skin 14, and the occurrence of the thickness unevenness of the entire skin 12 is suppressed.

  Moreover, the isocyanate which comprises the non-yellowing urethane in this embodiment is one selected from aliphatic isocyanate or alicyclic isocyanate. According to this structure, the yellowing by sunlight of a vehicle interior surface design skin can be prevented reliably.

  Moreover, as shown in FIGS. 3-11, the manufacturing method of the automotive interior goods 1 of this embodiment polymerized the isocyanate and polyol selected from aliphatic isocyanate or alicyclic isocyanate in a solvent. A first process (preheating process, first charging process, first process) in which a non-yellowing thermoplastic polyurethane powder 24 is charged into a heated nickel electroforming mold 21 and heat-sealed to form a first skin 13 having a predetermined thickness. Fusing step), a yellowing thermoplastic polyurethane powder 27 obtained by polymerizing an aromatic isocyanate and a polyol in a solvent and then adding a foaming agent and mixing the resulting mixture with a nickel electroforming mold 21 on which the first skin 13 is formed. A second process (mold opening process, second charging process, second fusion process, mold opening process) for forming a second skin 14 having a predetermined thickness by heating and fusing to nickel, nickel A third step (curing / foaming step, cooling step, demolding step) of melting and molding the first skin 13 and the second skin 14 and foaming the foaming agent of the second skin 14 by reheating the mold 21; It has the composition which has.

  According to the above configuration, in the powder slush molding method, after the non-yellowing thermoplastic polyurethane powder 24 is charged into the same heated nickel electroforming mold 21, the yellowing thermoplastic is subsequently mixed with an additive. Polyurethane powder 27 was introduced, and the two layers of the first skin 13 composed of non-yellowing urethane and the second skin 14 composed of yellowing urethane were contained in the nickel electroforming mold 21 in a semi-molten state. Form in state. Therefore, it is possible to form two layers by simply performing powder adhesion to the nickel electroforming mold 21 twice. In addition, since the second skin 14 is foamed at the same time during reheating to completely melt the semi-molten powder, the first and second skins can be melted without providing a special process for foaming. In addition, the second skin 14 can be foamed. Thereby, the lamination | stacking of the 1st skin 13 and the 2nd skin 14 by a powder slush molding method can be obtained, without raising a shaping | molding cost.

It is principal part sectional drawing of the interior goods for motor vehicles. It is explanatory drawing which shows the foaming state of the interior goods for motor vehicles. It is explanatory drawing of a preheating process. It is explanatory drawing of a 1st injection | throwing-in process. It is explanatory drawing of a 1st melt | fusion process. It is explanatory drawing of a mold opening process and a 2nd injection | throwing-in process. It is explanatory drawing of a 2nd melt | fusion process. It is explanatory drawing of a mold opening process. It is explanatory drawing of a curing and foaming process. It is explanatory drawing of a cooling process. It is explanatory drawing of a demolding process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automotive interior part 11 Base material 12 Skin 13 1st skin 14 2nd skin 21 Nickel electroforming mold 22 Heating device 23 First powder container 24 Non-yellowing thermoplastic polyurethane powder 26 Second powder container 27 Yellowing thermoplastic Polyurethane powder

Claims (3)

In automotive interior parts with at least a base material and a skin,
The skin has a first skin that is a vehicle interior design skin, and a second skin laminated on the first skin,
An automotive interior product, wherein the first skin composition is non-yellowing urethane and the second skin composition is foamed yellow urethane.   The automobile interior product according to claim 1, wherein the isocyanate constituting the non-yellowing urethane is one selected from aliphatic isocyanates or alicyclic isocyanates. In a method for producing an interior product for an automobile, comprising at least a base material and a skin, wherein the skin has a first skin that is a vehicle compartment surface design skin, and a second skin laminated on the first skin.
A non-yellowing thermoplastic polyurethane powder obtained by polymerizing an isocyanate selected from an aliphatic isocyanate or an alicyclic isocyanate and a polyol in a solvent is put into a heated mold and heat-fused to obtain a predetermined thickness. A first step of forming the first skin;
Putting a yellowing thermoplastic polyurethane powder obtained by polymerizing aromatic isocyanate and polyol in a solvent and then adding a foaming agent and mixing them into the mold having the first skin formed thereon, and heat-sealing. A second step of forming the second skin of a predetermined thickness by:
And a third step of melt-molding the first skin and the second skin and foaming the foaming agent of the second skin by reheating the mold.

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