KR20210052669A - Composite material for vehicle interior - Google Patents

Abstract

The present invention relates to a composite material for automobile interior material which can achieve weight reduction. The composite material includes: a core layer made of a polypropylene-based foam sheet; and a reinforcing layer laminated on one or both sides of the core layer and impregnated with wood powder and polyolefin-based resin. With this configuration, it is possible to achieve weight reduction to reduce exhaust gas through improved fuel efficiency, to have excellent rigidity, to increase recyclability during disposal, and to provide the composite material which is harmless to a human body.

Description

Composite material for automobile interior materials{COMPOSITE MATERIAL FOR VEHICLE INTERIOR}

The present invention relates to a composite material for automobile interior materials, and more particularly, it is possible to reduce exhaust gas through improved fuel efficiency by achieving light weight, excellent rigidity, and improved recyclability during disposal, and to the human body. It relates to a harmless composite material for automobile interior materials.

Conventionally, resin felt, wood powder reinforced board, paper board, and the like were used as a material for a covering self-structure for automobile interior materials.

The resin felt and the paper board are manufactured by impregnating a phenol resin or the like. Phenol resin, a curing agent, is a kind of thermosetting resin produced by the condensation reaction of phenols and aldehydes. Phenol and aldehyde released due to unreacted or incomplete combustion during incineration of phenolic resin are living environment including working environment. It acts as a pollutant of pollution, and there is a problem in that toxic gases are discharged during disposal incineration.

In addition, in the case of a substrate for automobile interior materials containing conventional glass fiber or glass chop, the problem of having a harmful effect on workers due to glass dust that may be generated during the manufacturing process and transportation process There is. In addition, an adhesive containing a volatile organic solvent for bonding the above materials must be used, and in this case, there is a problem that is harmful to the working environment and the human body.

On the other hand, the material of the conventional covering self-structure for automobile interiors is not excellent in sound insulation and heat insulation, has a high unit cost, is relatively high in weight, is easily deformed when used for a long time, is harmful to the human body, and is difficult to recycle.

The present invention is invented to solve the above problems, and achieves weight reduction to reduce exhaust gas through improved fuel economy, has excellent rigidity, and can increase recyclability during disposal, and is harmless to the human body. Its purpose is to provide a composite material for automobile interior materials.

In order to achieve the above object, a composite material for automobile interior materials according to a preferred embodiment of the present invention includes a core layer formed of a polypropylene-based foam sheet; And a reinforcing layer laminated on one or both sides of the core layer and provided by impregnating wood powder and polyolefin-based resin.

Here, the core layer may be provided with a polypropylene-based foam sheet having a foaming ratio of 10 to 50 times.

In addition, the core layer may be provided with a polypropylene-based foam sheet having a thickness of 1 mm to 5 mm.

In addition, the core layer may be provided with any one of a PVC foam sheet, a PE foam sheet, a PP foam sheet, a PET foam sheet, a PS foam sheet, and an EPS foam sheet.

The reinforcing layer may be prepared by mixing wood powder and a polyolefin-based resin in a ratio of 40:60 to 60:40% by weight.

In addition, the reinforcing layer may have a thickness of 1 mm to 2 mm.

Here, the wood powder may be provided with wood powder having an average particle size of 100 μm to 400 μm.

In addition, the wood powder may be provided with bamboo wood powder having an average particle size of 200 μm to 500 μm.

The polyolefin-based resin may be provided with at least one of polypropylene resin, polyethylene resin, and ABS resin, or a combination thereof.

Further, it may further include a skin layer laminated on the reinforcing layer and formed of a polypropylene-based nonwoven fabric or a polyester-based nonwoven fabric.

According to the composite material for automobile interior materials according to the present invention, it is possible to achieve weight reduction and reduce exhaust gas through improved fuel efficiency, excellent rigidity, and increase recyclability during disposal, and a composite material that is harmless to the human body is used. You can get the effect it provides.

1 is a view schematically showing a laminated structure of a composite material for a vehicle interior according to an embodiment of the present invention,
2 is a view schematically showing a structure in which a skin layer is further laminated on a composite material for automobile interior material according to an embodiment of the present invention.

In order to help understand the features of the present invention, the following will be described in more detail with respect to the composite material for automobile interior material related to an embodiment of the present invention.

In adding reference numerals to the components of the accompanying drawings to aid in understanding the embodiments described below, it should be noted that the same components are to have the same reference numerals as much as possible, even if they are indicated on different drawings. . In addition, in describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a diagram schematically showing a laminated structure of a composite material for automobile interiors according to an embodiment of the present invention, and FIG. 2 is a diagram schematically showing a structure in which a skin layer is further laminated on the composite material for automobile interiors. to be.

1 and 2, the composite material for automobile interior material 100 according to an embodiment of the present invention includes a core layer 110 made of a polypropylene-based foam sheet, and on one or both sides of the core layer 110. It includes a reinforcing layer 120 that is laminated and impregnated with wood powder and polyolefin-based resin.

Such, the composite material for automobile interior material 100 of the present invention is made of an eco-friendly material that can be recycled, and has excellent sound absorbing and insulating properties and thermal insulation properties.

The core layer 110 is provided with a polypropylene-based foam sheet, and the polypropylene-based foam sheet is a foam manufactured by using an extruder, that is, a foam extrusion method, and has a foam cell having a fine cell shape and has strength , It has excellent features of shape stability, heat insulation, and sound absorption.

In addition, the polypropylene-based foam sheet includes the steps of charging a mixture of essential components such as a pyrolytic foaming agent and polypropylene resin into a hopper, decomposing the resin melt and the foaming agent, and mixing and dispersing the resin and the foaming agent in the extruder. And cooling the mixture to a temperature suitable for foaming, extruding the mixture from a die so that the mixture is foamed, and cooling and molding the extrudate. Alternatively, it may be foamed using a gas such as carbon dioxide, butane, or propane instead of the pyrolytic foaming agent. In addition, the polypropylene resin, which is a material constituting the polypropylene foam sheet, may be a polypropylene homopolymer, a high melt strength polypropylene (HMS-PP), a copolymer, or the like. The method of manufacturing the polypropylene-based foam sheet is a known technique, and may be manufactured by any method other than the above-described method.

The polypropylene-based foam sheet prepared by the above method is not physically and chemically crosslinked, so it is excellent in recyclability. In addition, it has a fine foaming cell structure, is light in weight as it can apply a foam sheet of 5 to 30 times, and can be produced in a simpler process compared to the conventional crosslinked foam manufacturing process. Can be saved.

The polypropylene-based foam sheet, which is the core layer 110, may have a foaming ratio of 10 to 50 times, and it is more preferable to use a foaming ratio of 25 to 35 times. That is, when the expansion ratio is less than 10 times, it does not affect the improvement of the sound-absorbing property of the polypropylene-based foam sheet, and there is a problem in that the weight is relatively high. In addition, when the expansion ratio exceeds 30 times, the sound-absorbing property and light weight are improved, but there is a problem that strength and shape stability are deteriorated.

In addition, since the polypropylene-based foam sheet, which is the core layer 110, is used in a covering self-structure for automobile interiors, it must be formed in a certain dimension. That is, the thickness of the core layer 110 is preferably 1mm to 5mm, more preferably 2.5mm to 3.5mm. That is, if the thickness is less than 1 mm, there is a problem in that the strength is lowered, easily cracking, and the shape stability is deteriorated, and if the thickness exceeds 5 mm, there is a problem that light weight cannot be achieved.

The core layer 110 may be provided with any one of a PVC foam sheet, a PE foam sheet, a PP foam sheet, a PET foam sheet, a PS foam sheet, and an EPS foam sheet.

The reinforcing layer 120 is laminated on one or both surfaces of the core layer 110 and is provided by impregnating wood powder and polyolefin-based resin. That is, the reinforcing layer 120 is prepared in the form of a sheet by impregnating wood powder and a polyolefin-based resin, and laminated on the core layer 110.

The manufacturing method of the reinforcing layer 120 is a mixture of fine wood powder and a polyolefin resin in a ratio of 40:60 to 60:40% by weight, extruding at a temperature of 170 to 200°C, and then using a pair of hot pressing rollers. It is molded into a shape.

Here, when the wood powder is contained in an amount of less than 40% by weight, there is a problem of thermal deformation, cold impact resistance, and dimensional stability, and when it is contained in more than 60% by weight, there is a problem of reducing odor and VOC, productivity, and strength of the substrate.

More specifically, if the wood powder is contained in an amount of less than 40% by weight, the content of the filler, which is wood powder, is lowered, so there is a problem in that the product is broken due to insufficient absorption power to absorb external shocks, resulting in lower impact resistance. In addition, since the content of the polyolefin-based resin increases, deformation due to heat increases, so there is a problem in dimensional stability.

In addition, when the wood powder is contained in an amount exceeding 60% by weight, there is a problem that odor and VOC (volatile organic compounds) are generated because the content of the filler is increased, and the content of the polyolefin resin decreases, so that the strength of the substrate is reduced. There is a problem that the basic physical properties required for automobile interior materials are not satisfied because it is significantly lowered.

Such, the reinforcing layer 120 is preferably 1mm to 2mm in thickness, more preferably 1.3mm to 1.5mm in thickness. That is, if the thickness is less than 1 mm, there is a problem in that the strength is lowered, which is easily broken and the shape stability is deteriorated. If the thickness exceeds 2 mm, there is a problem in that light weight cannot be achieved.

Here, the wood powder may be prepared as wood having an average particle size of 100 μm to 400 μm. At this time, if a tree wood having an average particle size of less than 100 μm is used, there is a problem in that productivity is deteriorated due to insufficient cohesion during extrusion molding, resulting in a phenomenon of being cut off during product production. In addition, when a wood tree having an average particle size of the wood powder exceeding 400 μm is used, the mixing power with the polyolefin-based resin decreases and the dispersion is uneven, resulting in a problem in that the physical properties of the base material are uneven.

Alternatively, the wood powder is provided with bamboo wood having an average particle size of 200 µm to 500 µm. At this time, if the average particle size of the wood powder is less than 200 μm, the bamboo powder particles in the form of powder are insufficient in aggregating power during extrusion molding, resulting in a phenomenon of being cut off during product production, thereby reducing productivity. In addition, when bamboo wood having an average particle size of the wood powder exceeding 500 μm is used, the mixing power with the polyolefin resin decreases, and the dispersion is uneven, resulting in uneven physical properties of the base material.

In addition, the polyolefin-based resin may be formed of at least one of polypropylene (PP) resin, polyethylene (PE) resin, and ABS resin, or a combination thereof.

The stacking method of the core layer 110 and the reinforcing layer 120 prepared in this way may be stacked by a heat lamination molding method. That is, the reinforcing layer 120 and the core layer 110 are laminated by the thermal bonding method, rather than using an additional adhesive layer having adhesive strength such as an adhesive or hot melt.

When the composite material 100 for automobile interior material of the present invention is formed in a mold for producing a product in a state in which the reinforcing layer 120 made of wood powder and polyolefin resin is stacked on the core layer 110, Because the releasability with the mold is improved, workability is improved.

In addition, the composite material for automobile interior material 100 according to the present invention further includes a skin layer 130 laminated on the reinforcing layer 120 and provided with a polypropylene-based nonwoven fabric or a polyester-based nonwoven fabric.

The method of laminating the skin layer 130 and the reinforcing layer 120 may be laminated by a heat lamination molding method. That is, the skin layer 130 is laminated on the reinforcing layer 120 by the heat bonding method, rather than using an additional adhesive layer having adhesive strength such as an adhesive or hot melt.

Through this, since melt bonding is possible only by heat without using an adhesive, not only the operation is very simple, but also problems such as odors that have occurred when using the conventional adhesive can be solved.

In addition, since the polypropylene-based foam sheet used as the core layer 110 and the nonwoven fabric used as the skin layer 40 are materials of a similar series, defects occur during manufacturing or when the vehicle is scrapped, the skin layer 130 and the nonwoven fabric The core layer 110 can be pulverized and recycled as it is without separating, so that resources can be saved and an effect of providing an eco-friendly composite material can be obtained.

Example

Core layer Optimal range of foaming magnification

Hereinafter, the optimum range of the expansion ratio of the core layer in the composite material according to the embodiment of the present invention was selected.

Here, the composite material was prepared by laminating a core layer and a reinforcing layer on both sides of the core layer. In addition, the core layer was prepared by using a polypropylene (PP) foam sheet having a thickness of 2.5 mm at different expansion ratios, and the reinforcing layer was prepared by mixing wood wood powder and polyolefin resin in a ratio of 50:50 wt% and having a thickness of 1.3 mm. It was prepared as a sheet.

In the composite material thus prepared, the expansion ratio of the core layer was changed and the physical properties were measured, and are shown in Table 1 below.

Properties Core layer foaming ratio 35 times 30 times 25 times 20 times 15 times importance 0.698 0.702 0.706 0.711 0.712 Weight[g/m ² ] 2,750 2,775 2,800 2,825 2,850 Flexural strength [MPa] 46.6 59.2 70.3 70.3 70.3 Flexural modulus [MPa] 3,926 4,111 4,381 4,382 4,382 Bursting strength [MPa] 1.1 1.2 1.5 1.5 1.5 Falling impact
(-30℃ condition) Breakage occurs Breakage occurs no problem no problem no problem

As shown in Table 1, it can be seen that as the foaming ratio increases, the specific gravity and weight decrease at a constant rate.

In addition, it can be seen that the flexural strength and the rupture strength remain the same until the foaming ratio is increased to 25 times, and then rapidly decreased as they increase to 30 times or more. That is, it can be seen that the flexural strength decreases when the expansion ratio exceeds 25 times.

In addition, it can be seen that the flexural modulus remains almost the same until the expansion ratio becomes 25 times, but decreases constantly when the expansion ratio is 30 times or more. That is, it can be seen that the flexural modulus decreases when the expansion ratio exceeds 25 times.

Finally, it can be seen that the falling impact is broken when the foaming magnification is 30 times or more.

Therefore, it can be seen that the flexural strength, flexural modulus, and rupture strength decrease when the foaming ratio exceeds 25 times, and the falling ball impact property is also broken when the foaming ratio exceeds 25 times, so that the core layer of the present invention has a foaming ratio. It is preferable to use 15 times or more and 25 times or less.

Core layer Optimal range of thickness

Hereinafter, the optimum range of the thickness of the core layer in the composite material according to the embodiment of the present invention was selected.

Here, the composite material was prepared by laminating a core layer and a reinforcing layer on both sides of the core layer. In addition, the core layer was prepared by varying the thickness of a polypropylene (PP) foam sheet having a foaming ratio of 25 times, and the reinforcing layer was a sheet having a thickness of 1.3 mm prepared by mixing wood wood powder and polyolefin resin in a ratio of 50:50% by weight. Prepared as.

In the composite material thus prepared, the thickness of the core layer was changed and the physical properties were measured, and are shown in Table 2 below.

Properties Core layer thickness 1.5mm 2.0mm 2.5mm 3.0mm 3.5mm importance 0.668 0.675 0.706 0.735 0.752 Weight[g/m ² ] 2,720 2,765 2,800 2,845 2,868 Flexural strength [MPa] 46.6 59.2 70.3 69.1 68.5 Flexural modulus [MPa] 3,226 3,911 4,381 4,372 4,370 Bursting strength [MPa] 1.1 1.2 1.5 1.4 1.4 Falling impact
(-30℃ condition) Breakage occurs Breakage occurs no problem no problem no problem

As shown in Table 2, it can be seen that as the thickness of the core layer increases, the specific gravity and weight increase at a constant rate.

In addition, it can be seen that the flexural strength was rapidly improved as the thickness of the core layer became 2.5 mm, but was similar between 2.5 mm and 3.5 mm. That is, it can be seen that the flexural strength is almost similar without increasing significantly if the thickness of the core layer is 2.5 mm or more.

In addition, it can be seen that the flexural modulus increases until the thickness of the core layer becomes 2.5 mm, but does not increase any more when the thickness is 2.5 mm or more. That is, it can be seen that the flexural modulus is similar without significantly increasing when the thickness is 2.5 mm or more.

In addition, it can be seen that the bursting strength also increases rapidly when the thickness of the core layer becomes 2.5mm, and does not increase any more when the thickness is 2.5mm or more. That is, it can be seen that the rupture strength is similar without significantly increasing if the thickness is 2.5 mm or more.

Lastly, it can be seen that the fall impact does not cause cracking when the thickness of the core layer is 2.5mm or more.

Therefore, the flexural strength, flexural modulus, and rupture strength do not increase any more after a large increase as the thickness of the core layer becomes 2.5 mm, and the fall impact does not occur when the thickness of the core layer is 2.5 mm or more. It is preferable that the core layer has a thickness of 2.5 mm or more and 3.5 mm or less.

Reinforcement layer Optimal range of thickness

Hereinafter, the optimum range of the thickness of the reinforcing layer in the composite material according to the embodiment of the present invention was selected.

Here, the composite material was prepared by laminating a core layer and a reinforcing layer on both sides of the core layer. In addition, as the core layer, a polypropylene (PP) foam sheet having a foaming ratio of 25 times and a thickness of 2.5 mm was used, and the reinforcing layer was a sheet having a different thickness by mixing wood wood powder and polyolefin resin in a ratio of 50:50% by weight. Prepared as.

In the composite material thus prepared, the thickness of the reinforcing layer was changed, and the physical properties were measured, and are shown in Table 3 below.

Properties Reinforcement layer thickness 1.1mm 1.2mm 1.3mm 1.4mm 1.5mm importance 0.694 0.701 0.706 0.728 0.742 Weight[g/m ² ] 2,600 2,700 2,800 3,000 3,100 Flexural strength [MPa] 58.2 60.5 70.3 70.4 70.6 Flexural modulus [MPa] 2,740 3,490 4,381 4,388 4,389 Bursting strength [MPa] 1.1 1.3 1.5 1.5 1.6 Falling impact
(-30℃ condition) Breakage occurs Breakage occurs no problem no problem no problem

As shown in Table 3, it can be seen that as the thickness of the reinforcing layer increases, the specific gravity and weight increase at a constant rate.

In addition, it can be seen that the flexural strength and flexural modulus rapidly improved as the thickness of the reinforcing layer became 1.3 mm, but increased slightly from 1.3 mm to 1.5 mm. That is, it can be seen that the flexural strength is similar without significantly increasing when the thickness of the reinforcing layer is 1.3 mm or more.

In addition, it can be seen that the rupture strength increases at a constant rate until the thickness of the reinforcing layer becomes 1.3 mm, but does not increase any more when the thickness is 1.3 mm or more. That is, it can be seen that the rupture strength is similar without increasing significantly if the thickness is 1.3 mm or more.

Finally, it can be seen that the fall impact does not cause cracking when the thickness of the reinforcing layer is 1.3 mm or more.

Therefore, the flexural strength, flexural modulus, and rupture strength do not increase significantly after the reinforcing layer has a thickness of 1.3 mm, and then do not increase. Falling impact also does not occur when the thickness of the reinforcing layer is 1.3 mm or more, so that the reinforcing layer of the present invention is It is preferable that the thickness is provided with a thickness of 1.3 mm or more and 1.5 mm or less.

Comparison of conventional single material interior materials and composite materials of the present invention

[0003] A conventional covering shelf substrate for automobiles is made of a single material such as woodstock or bamboo stock.

Comparative Example 1 was prepared by mixing wood-wood powder and polyolefin resin in a ratio of 50:50% by weight using woodstock.

Comparative Example 2 was prepared by mixing bamboo fiber and a polyolefin resin in a ratio of 50:50% by weight using Bamboo Stark.

In addition, Example 1 was prepared by laminating a core layer and a reinforcing layer on both sides of the core layer. In addition, as the core layer, a polypropylene (PP) foam sheet having a foaming ratio of 25 and a thickness of 2.5 mm was used. In addition, the reinforcing layer was prepared by mixing wood wood powder and polyolefin resin in a ratio of 50:50% by weight, and a thickness of 1.3mm.

The materials for Comparative Examples 1 and 2 and Example 1 were prepared as specimens having the same weight, and physical properties were measured, and are shown in Table 4 below.

Properties Comparative Example 1 Comparative Example 2 Example 1 Weight[g/m ² ] 2,800 2,800 2,800 Flexural strength [MPa] 40.0 60.5 70.3 Flexural modulus [MPa] 3,772 3,961 4,381 Bursting strength [MPa] 1.6 1.6 1.5 Falling impact
(-30℃ condition) Breakage occurs no problem no problem

As shown in Table 4, it can be seen that the flexural strength of Example 1 is increased by about 75% compared to Comparative Example 1, and that the flexural strength is increased by about 16% compared to Comparative Example 2.

In addition, it can be seen that Example 1 increases the flexural modulus by about 16% compared to Comparative Example 1, and about 10% compared to Comparative Example 2.

In addition, it can be seen that the bursting strength of Example 1 is substantially similar to that of Comparative Examples 1 and 2.

In addition, it can be seen that only Comparative Example 1 is broken, and there is no abnormality in Example 1 and Comparative Example 2 in the falling impact.

Accordingly, it can be seen that the composite material of the present invention greatly increases the flexural strength and flexural modulus compared to the conventional single material, relative to the same weight.

In conclusion, if the composite material of the present invention is used, weight reduction can be achieved by minimizing the weight within a range that satisfies the basic physical properties required for automobile interior materials.

As described above, although the present invention has been described by the limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following by those of ordinary skill in the art to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equivalent range of the claims to be described.

100: composite material for automobile interior materials
110: core layer
120: reinforcement layer
130: epidermal layer

Claims (10)

A core layer made of a polypropylene-based foam sheet; And
A reinforcing layer laminated on one or both sides of the core layer, and impregnated with wood powder and a polyolefin-based resin;
Composite material for automobile interior materials comprising a.
The method of claim 1,
The core layer,
A composite material for automobile interiors, characterized in that it is a polypropylene-based foam sheet having a foaming ratio of 10 to 50 times.
The method of claim 1,
The core layer,
Composite material for automobile interiors, characterized in that the polypropylene-based foam sheet is provided with a thickness of 1mm to 5mm.
The method of claim 1,
The core layer,
PVC foam sheet, PE foam sheet, PP foam sheet, PET foam sheet, PS foam sheet, a composite material for automobile interiors, characterized in that provided in any one of the EPS foam sheet.
The method of claim 1,
The reinforcing layer,
A composite material for automobile interiors, characterized in that wood powder and polyolefin-based resin are mixed in a ratio of 40:60 to 60:40% by weight.
The method of claim 1,
The reinforcing layer,
Composite material for automobile interiors, characterized in that the thickness is provided in 1mm to 2mm.
The method of claim 1,
The wood flour,
A composite material for automobile interiors, characterized in that it is made of wood and wood powder having an average particle size of 100 μm to 400 μm.
The method of claim 1,
The wood flour,
Composite material for automobile interiors, characterized in that it is made of bamboo wood powder having an average particle size of 200 µm to 500 µm.
The method of claim 1,
The polyolefin resin,
Composite material for automobile interiors, characterized in that it is provided with at least one of polypropylene resin, polyethylene resin, and ABS resin, or a combination thereof.
The method of claim 1,
A skin layer laminated on the reinforcing layer and formed of a polypropylene-based nonwoven fabric or a polyester-based nonwoven fabric;
Composite material for automobile interiors, characterized in that it further comprises.

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