JPH1191454A - Interior trim member for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interior trim member for an automobile which is excellent in lightness, rigidity, high productivity and sanitariness and has the excellent antibacterial action and antibacterial action maintaining performance by using a particularly small quantity of an antibacterial agent. SOLUTION: In an interior trim member for an automobile whose outermost layer is an antibacterial agent containing resin layer and which is molded by thermoplastic resin multilayer blow molding, it is formed of three layers or more, and both the outermost layer and the inmost layer can be formed as an antibacterial agent containing resin layer. In this case, the antibacterial agent containing resin layer contains an inorganic antibacterial agent by 0.1 to 15 wt.%, and a thickness of the antibacterial agent containing resin layer is desirably set to 1/50 to 3/4 of a thickness of the whole layers. It is suitable for an instrument panel by using a polyolefin resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automotive interior member formed by multi-layer blow molding provided with antibacterial properties. More specifically, the present invention relates to an interior member for automobiles which is excellent in lightness, rigidity, productivity, hygiene, and the like by blow molding, and particularly has excellent antibacterial action and sustained antibacterial action by using a small amount of an antibacterial agent.

[0002]

2. Description of the Related Art Conventionally, interior parts for automobiles such as instrument panels, door trims, rear board units, console boxes, etc. are made of polypropylene which is excellent in moldability due to requirements for lightness, design, corrosion resistance and productivity. Thermoplastic resins such as resins have been used. Conventionally, an injection molding method has been generally adopted for these automobile interior members. However, these automobile interior members are relatively large members, and have problems such as requiring a large injection molding machine, high mold clamping pressure, and a mold having high durability. As this improvement method, a gas assist injection molding method has been proposed, but the mold structure becomes complicated,
It is a combination of a plurality of parts, has a large number of parts, and has the essential problems of the injection molding method such as the necessity of a secondary assembly process. In particular, it is substantially impossible to mold a member having a multilayer structure.

[0003] On the other hand, there is an increasing demand for interior parts for automobiles to suppress contamination by bacteria and fungi, to suppress general dirt, and to reduce the time and labor for cleaning. To respond to this,
It is also conceivable to increase the antibacterial property by blending an antibacterial agent with the thermoplastic resin used. However, automotive interior components are generally relatively large products, and it is necessary to maintain antimicrobial performance over a long period of time. In fact, products having high antibacterial properties have not been put to practical use.

[0004]

SUMMARY OF THE INVENTION According to the present invention, under such circumstances, a small amount of resin is used even in automobile interior parts such as instrument panels, which have a problem of contamination by bacteria and fungi. Resource saving, lightweight,
High rigidity, high antibacterial performance, and long-lasting antibacterial performance.In addition, physical properties such as bending strength, impact strength, and rigidity and surface characteristics can be arbitrarily controlled, and multiple functions can be integrated. It is an object of the present invention to provide an interior member for an automobile having excellent antibacterial properties that is also excellent in economic efficiency.

[0005]

The present inventors have conducted intensive studies on the antibacterial performance and the form of use of the antibacterial agent in automobile interior members. As a result, the present inventors have adopted a multilayer blow molding method as a molding method, By selectively adding the compound only to the specific resin layer, it has been found that a sufficient antibacterial action can be maintained for a long time even with the use of a small amount of an antibacterial agent. The present invention has been completed based on such findings.

That is, the present invention provides (1) an automobile interior member formed by thermoplastic resin multilayer blow molding, wherein the outermost layer is an antibacterial agent-containing resin layer. (2)
The automotive interior member according to the above (1), wherein the innermost layer is also an antibacterial agent-containing resin layer, and the innermost layer includes three or more layers. (3) The antibacterial agent-containing resin layer contains 0.1 to 15 inorganic antibacterial agents.
The automotive interior member according to the above (1) or (2), which contains about 1% by weight. (4) The automotive interior member according to any one of (1) to (3), wherein the thickness of the antimicrobial agent-containing resin layer is 1/50 to 3/4 of the total thickness of each layer. (5) The automotive interior member according to any one of the above (1) to (4), wherein the thermoplastic resin is a polyolefin resin. (6) An automotive interior member according to any one of the above (1) to (5), wherein the automobile interior member is an instrument panel.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The resin used for the automotive interior member of the present invention is not particularly limited as long as it is a thermoplastic resin and can be blow-molded. For example, polypropylene, polypropylene-based resin such as ethylene-propylene block copolymer or random copolymer, polyolefin-based resin such as high-density polyethylene, rubber-modified polystyrene resin, AB
Examples include S resin, polyvinyl chloride resin, polyamide resin, polycarbonate resin, and polyester resin. Among these resins, polyolefin resins such as polypropylene resins and high-density polyethylene are preferably used. The polypropylene resin has a melt index (MI) of 0.05 to 2 g / 10 min, preferably 0.1 to 1 g / 10 min. Further, as a high-density polyethylene resin, the density is 940 to 970 kg / m ^3.
The melt index (MI) is 0.05 to 2 g /
10 minutes, preferably 0.1 to 1 g / 10 minutes. If the MI is outside this range, blow molding properties such as drawdown resistance may be reduced depending on the size and weight of the molded product, and it may be difficult to perform stable continuous molding. The measurement of MI was carried out according to JIS K7210.
Load: 2.16 kg, temperature: polypropylene: 230
° C, polyethylene: 190 ° C.

[0008] These resins may be used as impact modifiers such as ethylene-propylene copolymer rubber, polybutadiene rubber, styrene-butadiene-styrene block copolymer rubber (SBS), and styrene-ethylene-hydrogenated SBS. Butylene-styrene block copolymer rubber (SE
Rubbers such as BS) can also be added. In addition, if necessary, considering the required characteristics and the like depending on the type of automobile interior member, metal powder, carbon black, graphite, talc, mica, clay, calcium carbonate, silica, aluminum hydroxide, magnesium hydroxide, calcium sulfate, Inorganic fillers and reinforcing agents such as glass fiber, carbon fiber, calcium titanate whisker, fibrous magnesium oxysulfate, crystallization accelerator, antioxidants (phosphorous, phenolic, sulfuric, etc.), neutralizing agents, Foaming agents, lubricants, dispersants, peroxides, heat stabilizers, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, flame retardant aids, plasticizers, epoxy compounds, metal deactivators, pigments, Additives such as dyes can also be added.

In the present invention, a pellet obtained by blending a known additional additive with these thermoplastic resins, if necessary, and kneading them is used as a raw material. These raw materials are supplied to a multilayer blow molding apparatus provided with two or more extrusion molding machines, and a molten parison is extruded from a multilayer die. Supply and close the mold, or blow gas such as air into the parison while closing, transfer to the mold surface and shape it.After cooling as necessary, open the mold and take out the molded product. By performing the removing process, an interior member for an automobile can be obtained.

In the present invention, multi-layer blow molding is performed in two or more layers, and an antibacterial agent is selectively added to a thermoplastic resin for forming the outermost layer. More preferably, an antimicrobial agent is selectively added to the resin of the outermost layer and the innermost layer in a three-layer structure or more. The antibacterial agent to be used is not particularly limited, and known inorganic antibacterial agents and organic antibacterial agents can be used. As inorganic antibacterial agents, amorphous aluminosilicates, natural or synthetic zeolites (A type, Y type),
Antibacterial metals such as silver, copper, zinc, tin, bismuth, and cadmium are ion-exchanged on a carrier such as zirconium phosphate, apatite, and silica gel. Examples of the organic antibacterial agent include 2- (4-thiazolyl) benzimidazole, N- (fluorodichloromethylthio), oxybisphenoxyarsine, paradichlorobenzene, and parachlorometaxylol.
In addition, inorganic antibacterial agents exhibit excellent antibacterial performance against bacteria and microorganisms, while organic antibacterial agents exhibit excellent antibacterial performance against fungi. Therefore, it may be preferable to select and add one or a combination of two or more antibacterial agents in consideration of the type of interior parts for automobiles and the like. The content of the antibacterial agent, particularly the inorganic antibacterial agent, is set to be 0.1 to the outermost resin layer.
It is in the range of 1 to 15% by weight, preferably 0.2 to 5% by weight, particularly preferably 0.2 to 3% by weight. This content is appropriately determined in consideration of the amount of the active ingredient in the antibacterial agent, the thickness of the outermost layer or the innermost layer, the antibacterial performance required for an automobile interior member, and the like. The antibacterial agent used for the thermoplastic resin may be generally sold as a masterbatch resin containing about 10% by weight of the antibacterial agent, but here means the amount of the antibacterial agent itself excluding the resin.

Next, the ratio of the outermost layer or the innermost layer of the antibacterial agent-containing resin to the total thickness is from 1/50 to 3 /
4, preferably in the range of 1/10 to 1/5, which is related to the overall thickness due to the strength and the like of the automobile interior member. Therefore, the thickness of the antimicrobial-containing resin layer can be defined as an absolute thickness, usually 0.1 to 10 m
m, preferably 0.2 to 3 mm. In the present invention, in order to enhance the antibacterial effect, the thickness of the antibacterial agent-containing resin layer is reduced and its concentration is increased, so that even when the same amount of the antibacterial agent is used, the antibacterial agent particles are molded. It is a major feature that the antibacterial agent is extruded on the surface of the material and can be used efficiently and effectively. In the case where the interior of the hollow portion of the automobile interior member is used as a duct portion or the like, as described above, a multilayer structure having three or more layers is preferably used in which an antibacterial agent is added to the innermost resin. May be preferred.

As described above, the present invention has a multilayer thermoplastic resin structure. Therefore, a significant feature of the present invention is that the thermoplastic resin used for each layer, and further, the compounding and additives of the resin-modified rubber can be freely selected. Specifically, the antibacterial agent-containing resin layer as the outermost layer is a resin with high scratch resistance and high hardness, a resin with good surface characteristics, and a resin with excellent impact resistance as a resin of the inner layer or the intermediate layer, and a high rigidity. And the like. For example, by using homopolypropylene having high stereoregularity as the outermost layer resin, and using a propylene-ethylene block copolymer or a resin in which rubbers are blended with the propylene-ethylene block copolymer as the inner layer or intermediate layer resin, impact strength and scratch resistance are improved. Thus, it is possible to obtain an automobile interior member satisfying both. Further, in order to provide a soft touch feeling as the outermost layer, a polyolefin-based thermoplastic elastomer can be used. Furthermore, the choice of resin includes the size of the interior member for automobiles,
Drawdown resistance during blow molding is required due to weight and other factors.In this case as well, select a resin with excellent drawdown resistance as the main resin independently of the outermost resin or innermost resin. it can. Also, additives required only on the surface, such as a colorant and an antistatic agent, can be added only to the outermost layer.

As described above, as the multilayer structure of the present invention, the type of resin can be freely selected in accordance with the required characteristics.
An adhesive resin layer of an unsaturated carboxylic acid or a derivative thereof modified polyolefin can also be used. Also, if necessary for heat insulation, sound insulation, etc., provide a foaming agent addition layer,
A multilayer structure having a foamed structure layer may be used. Furthermore, in the case of a duct integral structure in blow molding, for example, it is preferable to provide an antibacterial performance to both the inner and outer layers as a three or more layer structure in which an antibacterial agent is added as the innermost layer in the same manner as the outermost layer. This is as described above.

FIG. 1 is a front view of an instrument panel formed by a blow molding method, which is an example of an inner layer member for an automobile of the present invention, FIG. 2 is a rear view thereof, and FIGS. 1 shows cross-sectional views of A, B, C, and D, respectively. FIGS. 7A and 7B show a blow molding step, in which FIG. 7A is a sectional view of a molding die before air blowing, and FIG. In FIGS. 3 to 7, each layer actually has a two- to three-layer structure, but the outer layer is very thin, and thus the illustration of the outer layer is omitted in the drawings.

In the drawing, 1 is a front member, 2 is a back member, E is a junction between the front member and the back member, 3 is a duct for air conditioning in the vehicle, 4 is a duct for defrosting the windshield, and 5 is an opening for air conditioning in the vehicle. , 6 is a defrost opening, 7 is an air-conditioning air inlet, 8 is a defrost air inlet, 9 is the outermost layer,
0 is an inner layer, 30 is a parison, 31.32 is a mold, 35 is a blow air blow-in pipe, 36 is a blow air discharge pipe,
37 is a burr.

An example of an interior member for a vehicle according to the present invention,
FIGS. 7A and 7B show a method of forming an instrument panel.
This will be described below. With the molds 31.32 open, the multilayer parison 30 is extruded in a tubular form from a multilayer die, suspended between the molds 31.32, the tip of the parison is closed, and air provided on the die (not shown) is provided. After a suitable amount of air is blown from the injection pipe to obtain the state shown in FIG. 7A, the mold is completely closed. During or after the closing of the mold, a plurality of blow-air blowing pipes 35 are pierced into the parison wall to blow air, and the mold surface 31A. A parison is closely attached to 32A and shaped (FIG. 7 (B)). At this time, the front member 2 and the back member 3 are formed by the parison, and the convex portion formed by the two dies has a structure illustrated in which a portion E where the front member and the back member are joined is formed. . With this structure, even if it is a relatively thin molded product, it becomes a composite structure of the joint portion and the hollow portion, and the interior member has high strength and rigidity. Further, the hollow portion may be a plurality of hollow portions. In this case, it is preferable from the viewpoint of mold transfer to blow air independently. In general, blow air is discharged from a discharge pipe while maintaining a certain pressure after blow molding, thereby cooling the molded product from the inside of the hollow part, shortening the molding cycle and improving productivity. Improvement can be achieved. After cooling so that the mold can be taken out, the mold is opened, the molded product is taken out, and the burr 13 is removed to obtain a final automobile interior member.

According to the present invention, as described above, the instrument panel main body and the duct portion can be integrally formed by a single molding, which is compared with the conventional case where each part is formed by injection molding and then assembled. As a result, the overall weight can be reduced and the rigidity can be increased, and the secondary processing is not required, thereby improving the productivity. The automotive interior member of the present invention is not particularly limited, and examples thereof include an instrument panel, a door trim, a rear board unit, a console box, and a seat.

[0018]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Example 1 Molding of a two-layer instrument panel (see FIG. 1) Molding machine: Large multilayer blow molding machine [Ishikawajima-Harima Heavy Industries, IPB-EPML-90S, 5-layer forming machine (2 types 2
Use as layer device] 2. Instrument panel: The shape shown is a schematic shape with a width of 1400 mm and a height of 400 mm. 3. Resin layer (1) Outermost layer resin: Polypropylene resin [Idemitsu Petrochemical, IDEMITSU PP E-185G, MI: 0.5 g / 10 min] = 95
weight%. Antibacterial agent [Toa Gosei, Novalon MZP7100 (silver /
Zirconium phosphate-based 10% masterbatch] = 5% by weight. (2) Inner layer resin: polypropylene resin of (1): 100
%. (3) Average thickness of resin layer: outermost layer = 0.3 mm, inner layer =
2 mm. 4. Based on the above conditions, each resin was supplied to an extruder, melt-kneaded at a temperature of 210 ° C., two layers of parison were extruded between dies from a die, and after closing the dies, a pressure of 0.4 MPa was applied. The air is blown into the mold and transferred, and after cooling,
The mold was opened to form an instrument panel. 5. Evaluation of antibacterial activity The rate of bacterial reduction on the outer surface after 24 hours by a film adhesion method using a cut-out piece at the front was 99.9% or more. The inner surface was 0%. In addition, JIS Z2911
The occupied area when the black mold was cultured according to the above was 1/3 of the entire surface on the outer surface. In addition, it proliferated in the whole surface on the inner surface.

Example 2 Molding of a three-layer instrument panel (see FIG. 1) Molding machine: Large multilayer blow molding machine [Ishikawajima-Harima Heavy Industries, IPB-EPML-90S, 5-layer forming machine (3 types, 3
1. Used as layer device) Instrument panel: As a general shape, width 1
The shape shown is 400 mm, 400 mm high. 3. Resin layer (1) Outermost layer resin: Polypropylene resin [Idemitsu Petrochemical, IDEMITSU PP E-185G, MI: 0.5 g / 10 min] = 95
weight%. Antibacterial agent A [manufactured by Kanebo, XM-DJ101 (silver / zeolite A system) bacterikiller 10% masterbatch. ] = 5
% By weight of the resin composition. (2) Intermediate layer resin: polypropylene resin of (1): 10
0%. (3) Innermost layer resin: polypropylene resin [IDEMITSUPP E-185G, manufactured by Idemitsu Petrochemical, MI: 0.
5 g / 10 min] = 92% by weight. Antibacterial agent A [manufactured by Kanebo, XM-DJ101 (silver / zeolite A system) bacterikiller 10% masterbatch. ] = 5
weight%. Antimicrobial agent B (manufactured by Dainichi Seika Co., Ltd., PE-M707 (Diekiller Masterbatch) = resin composition with 3% by weight) (2) Average thickness of resin layer: outermost layer = 0.3 mm, middle layer = 2 mm, Inner layer = 0.3 mm 4. Based on the above conditions, each resin is supplied to an extruder, melt-kneaded at a temperature of 210 ° C, three layers of parison are extruded between dies from a die, and the dies are closed. After that, air at a pressure of 0.4 Mpa was blown into the mold, and the mold was cooled.
The mold was opened to form an instrument panel. 5. Evaluation of antibacterial activity Both the outer surface and the inner surface after 24 hours of the cut-out piece of the front face by the film adhesion method had a bacteria reduction rate of 99.9% or more. Moreover, the occupied area when the black mold was cultured according to JIS Z 2911 was 1/3 of the total area on the outer surface and 1/5 of the total area on the inner surface.

Comparative Example 1 A single-layer instrument panel was formed in the same manner as in Example 1, except that a single layer consisting of only the antibacterial agent-containing resin layer was formed. In this case, the amount of the inorganic antibacterial agent used was about 7.7 times that of Example 1. 1. Evaluation of antibacterial activity The bacterial reduction rate after 24 hours by a film adhesion method using a cut-out piece of the front part was 99.9% or more. Also, JIS
The occupied area when cultivating black mold according to Z 2911 is one-third of the total area of both the outer surface and the outer surface, and the antibacterial property is substantially increased despite the remarkably large amount of the antibacterial agent used. It did not change.

[0021]

According to the present invention, the antibacterial performance is high, the durability is excellent, and the use efficiency of the antibacterial agent is high, so that the economic efficiency is high and the antibacterial level is high. An automotive interior member is obtained. further,
It is lightweight, has excellent strength and rigidity, and has a wide selection range of resins and additives for the outermost layer and other layers, making it possible to respond to a wide range of performance requirements depending on the type of automotive interior parts. It has excellent effects.

[Brief description of the drawings]

FIG. 1 is a front view of an instrument panel according to an embodiment of the present invention.

FIG. 2 is a rear view of the instrument panel according to the embodiment of the present invention.

FIG. 3 is an AA sectional view of FIG. 1, which is an instrument panel according to the embodiment of the present invention.

FIG. 4 is a sectional view taken along the line BB of FIG. 1, which is an instrument panel according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view of the instrument panel according to the embodiment of the present invention, taken along the line CC in FIG. 1;

FIG. 6 is a sectional view taken along line DD of FIG. 1, which is an instrument panel according to the embodiment of the present invention.

FIG. 7 is a sectional view of a metal mold showing a molding process of the instrument panel according to the embodiment of the present invention.

[Explanation of symbols]

 1: Front member 2: Back member E: Joint between front member and back member 3: In-vehicle air conditioning duct 4: Defrost duct in front glass 5: In-vehicle air conditioning opening 6: Defrosting opening 7: Air inlet 8: Air inlet for defrost 9: Outermost layer 10: Inner layer 30: Parison 31.32: Die 35: Blow air blowing pipe 36: Blow air discharge pipe 37: Burr

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B60K 37/00 B60R 21/045 D B60R 21/045 B60J 5/00 501A

Claims (6)

[Claims] 1. An automotive interior member formed by thermoplastic resin multilayer blow molding, wherein the outermost layer is an antimicrobial agent-containing resin layer. 2. The interior member for an automobile according to claim 1, wherein the innermost layer is also a resin layer containing an antibacterial agent and is composed of three or more layers. 3. The antibacterial agent-containing resin layer contains 0.1% of an inorganic antibacterial agent.
The automotive interior member according to claim 1, wherein the content of the interior component is from 15 to 15% by weight. 4. The automobile interior member according to claim 1, wherein the thickness of the resin layer containing the antibacterial agent is 1/50 to 3/4 of the total thickness of each layer. 5. The automotive interior member according to claim 1, wherein the thermoplastic resin is a polyolefin resin. 6. The vehicle interior member according to claim 1, wherein the vehicle interior member is an instrument panel.