KR20130058912A - Polyurethane composition for automobile interior material - Google Patents

Abstract

The present invention relates to a polyurethane foam composition for automotive interiors, and more particularly, to a polyurethane foam composition for automotive interiors that can be compression molded and improved sound absorption performance and heat resistance performance.
To this end, the present invention is a polyurethane foam composition for automobile interiors, characterized in that the composition is formed by mixing a thermoplastic polyurethane powder, calcium carbonate and / or expanded graphite powder, kraft pulp powder and / or short aluminum fibers in a foamable polyurethane raw material to provide.

Description

Polyurethane foam composition for automobile interiors {Polyurethane composition for automobile interior material}

The present invention relates to a polyurethane foam composition for automotive interiors, and more particularly, to a polyurethane foam composition for automotive interiors that can be compression molded and improved sound absorption performance and heat resistance performance.

Interior materials commonly used in automobiles include car seats, door trims, boards, trunk stands, package trims and headliners.

These automotive interior materials are mainly composed of a substrate formed of a material such as polyprophylene, wood fiber, wood stock, etc., and a skin of chemical fiber material fused to the surface of the substrate. Due to the different physical properties required, not one material but several materials are applied to form a multi-layered structure.

For example, in the case of the ceiling interior material, the first glass fiber mat layer and the second glass fiber mat layer for stiffness are bonded to both sides of the flexible polyurethane (PU) foam layer for the effect of sound insulation or sound absorption and the outer side thereof A white nonwoven fabric layer is hot-melt bonded to a surface to form a base layer, and a surface layer of a cloth, a woven fabric, a nonwoven fabric, or the like is hot-melt bonded to the surface of the base layer.

In the case of the interior material having such a laminated structure, the material constituting each layer must be separately manufactured and laminated again, and the molding process must be performed according to the shape of the interior material. There is.

In addition, since the interior material itself contains bending or irregularities, etc., it is very difficult to mold and has a disadvantage of costly molding.

1 is a schematic view showing a cross-sectional structure of a vehicle interior according to the prior art, the chemical bond non-woven fabric is laminated on both the upper and lower sides of the glass wool or resin felt.

However, the conventional automotive interior as shown in FIG. 1 has the problems as shown in Table 1 below.

On the other hand, although the conventional thermosetting rigid polyurethane foam used as a base material for automobile interior materials is a material having excellent heat insulating effect and strength, the properties that are restored to its original form after molding due to the thermosetting properties during compression molding (compression molding) There is a disadvantage that compression molding is impossible.

Therefore, conventional soft polyurethane foam that can be compression molded and excellent in sound absorption is used, but it is weak in strength and must be used together with a separate structural reinforcement material. The rigid polyurethane foam has excellent rigidity but low sound absorption, so that the interior material There was a problem that was difficult to use.

The present invention has been invented to solve the above problems, it is possible to compression molding to the shape according to the application area of the vehicle and at the same time can improve the sound absorption performance and heat resistance performance to meet the complex physical properties required as automotive interior materials It is an object to provide a polyurethane foam composition for automotive interior materials that can be.

In order to achieve the above object, the present invention is an automobile interior material characterized in that the thermoplastic polyurethane powder, calcium carbonate powder and / or expanded graphite powder, kraft pulp powder and / or short aluminum fibers are mixed with a foamed polyurethane raw material It provides a polyurethane foam composition for.

Preferably, the thermoplastic resin powder is polypropylene resin, epoxy resin, polyethylene resin, polyvinyl chloride, nylon, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polyoxymethylene, polystyrene, ABS resin, Teflon resin, phenol It is characterized in that the resin, melamine resin and one selected from the group consisting of a mixture thereof.

In addition, the thermoplastic resin powder is mixed in an amount ratio of 5 to 35 parts by weight based on 100 parts by weight of the expandable polyurethane.

The calcium carbonate powder and / or expanded graphite powder is added in an amount of 1 to 12 parts by weight based on 100 parts by weight of the expandable polyurethane, and the kraft pulp powder and / or the short aluminum fiber is 1 to 12 parts by weight based on 100 parts by weight of the expandable polyurethane. 12 parts by weight is added.

In addition, latex and a surfactant are added to the expandable polyurethane raw material in order to increase dispersibility.

By manufacturing automobile interior materials using the polyurethane foam composition for automobile interiors according to the present invention, it has sound absorption performance equivalent to that of conventional flexible polyurethane foams and at the same time has excellent heat resistance and strength as compared to conventional flexible polyurethane foams. Excellent physical properties and easy compression molding enables the molding of the interior materials according to the shape of the application portion of the vehicle by using a mold.

1 is an exemplary view schematically showing a cross-sectional structure of a vehicle interior according to the prior art
Figure 2 is an exemplary view schematically showing a cross-sectional structure of the interior material for automobiles manufactured using the polyurethane foam composition according to the present invention
3 is a view showing a sound absorption performance measurement results according to Experimental Example 2 of the present invention.
4 is a view showing the heat resistance performance measurement results according to Experimental Example 2 of the present invention.

Hereinafter, the polyurethane foam composition according to the present invention will be described in detail.

The present invention relates to a polyurethane foam composition which can be compression molded as an interior material for automobiles and can improve sound absorption and heat resistance, according to an application site, and an epoxy resin powder which is cured at a high temperature of 170 ° C. or higher on a foamable polyurethane raw material. Or by mixing the thermoplastic resin polypropylene resin powder to enable compression molding, by mixing the powdered calcium carbonate and / or expanded graphite to improve the heat resistance performance, kraft pulp powder and / or short aluminum fibers to absorb sound Provided is a polyurethane foam composition with improved performance.

The polyurethane foam composition is a foam composition which is formed by sheet molding to produce a foam sheet, and compression molding is possible with a surface protective material such as a nonwoven fabric according to the use, and excellent physical properties as a vehicle interior material.

More specifically, the polyurethane foam composition according to the present invention is a semi-hard polyurethane foam material that can be molded as a base material for automobile interior materials through compression molding.

The polyurethane foam composition of the present invention is a thermoplastic resin powder that improves compression molding and shape retention performance on a foamable polyurethane material (or polyurethane foam) as a raw material, and calcium carbonate powder and / or expansion that improves heat resistance and flame resistance. The composition is prepared by mixing and adding graphite powder and kraft pulp powder and / or short aluminum fiber to improve sound absorption performance.

The thermoplastic resin powder may be a powdery thermoplastic resin powder or a high temperature curable resin powder, and specifically, polypropylene resin, epoxy resin, polyethylene resin, polyvinyl chloride, nylon, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, It is possible to use one selected from the group consisting of polyoxymethylene, polystyrene, ABS resin, Teflon resin, phenol resin, melamine resin and mixtures thereof.

The thermoplastic resin powder is added to the expandable polyurethane to act as a binder that binds to the expandable polyurethane, which is cured during compression molding of the polyurethane foam composition, and must be a material that can be powdered into a solid phase, and the content of the expandable polyurethane 5 to 35 parts by weight based on 100 parts by weight.

If the content of the thermoplastic resin powder is less than 5 parts by weight, the polyurethane foam (or foamable polyurethane) may not be sufficiently supported after compression molding to maintain the shape of the automotive interior after molding and cause deformation, and exceed 35 parts by weight. This reduces the relative content ratio of the polyurethane material, which makes the polyurethane foam so hard that it lowers the sound absorption and thermal insulation performance.

Since the resin powder is added to the foamable polyurethane material, the resin powder is cured at a high temperature around 170 ° C., which is a general compression molding temperature during compression molding of the polyurethane foam composition, and thus, physically squeezed between the urethane polymer chains forming the foam structure during molding. It acts like an entangled adhesive, thereby enabling compression molding of polyurethane foams.

The short aluminum fiber, kraft pulp, calcium carbonate, and expanded graphite are easily available additives on the market, and the short aluminum fiber is a product of Dazheng Metal Fiber Co., Ltd. of China, which forms metal aluminum into a fiber to wool. It is a fibrous particle that is crushed and made into 5 mm or less in length. Each of these additives may be used in an amount of 1 to 12 parts by weight.

That is, powdered calcium carbonate or expanded graphite is added in an amount of 1 to 12 parts by weight based on 100 parts by weight of the expandable polyurethane, and kraft pulp powder or short aluminum fiber is also added in an amount of 1 to 12 parts by weight based on 100 parts by weight of the expandable polyurethane.

Alternatively, the total amount of powdered calcium carbonate and expanded graphite is added in 1 to 12 parts by weight based on 100 parts by weight of the expandable polyurethane, and the total amount of kraft pulp powder and short aluminum fiber is 1 to 12 parts by weight based on 100 parts by weight of the expandable polyurethane. Part is added.

In other words, the mixed additives for improving the heat resistance and flame retardancy of the expandable polyurethane and the mixed additives for increasing the sound absorption performance are each added in an amount of 1 to 12 parts by weight based on 100 parts by weight of the expandable polyurethane.

As is well known, polyurethane foam (foamable polyurethane) is a material belonging to the porous by classification, and has excellent foaming effect in the mid-to-high range because it has bubbles of countless cells due to its structural characteristics. It is approximately 30-80 pieces / 25mm.

As is known, when the generated sound is incident on the polyurethane foam, the sound wave enters the polyurethane foam through the fine pores in the bubble, and when the sound wave is transmitted in the bubble, the sound wave touches the membrane surface by touching the bubble membrane wall. And some of the negative energy is consumed due to the vibrational movement or the heat generated by the vibration, and the factors which dominate the sound absorption performance of the polyurethane foam include the thickness of the foam inside the foam, the negative frequency, and the air permeability. Resistance to flow), the number of bubbles, the conditions behind the sound absorbing material, and the like.

Accordingly, the polyurethane foam composition of the present invention improves sound absorption performance by adding kraft pulp powder and / or short aluminum fiber to a foamable polyurethane (polyurethane foam) material.

The kraft pulp and aluminum short fibers are partially fixed in the bubbles of the polyurethane foam to vibrate as sound to assist sound absorption performance.

The semi-rigid polyurethane foam according to the present invention has a relatively stronger chain structure of the polymer than the conventional soft polyurethane foam, thereby providing excellent rigidity and heat resistance, and adding kraft pulp powder and / or short aluminum fiber. As a result, the sound absorption performance can be improved to the same level as that of the conventional soft polyurethane foam.

The expandable polyurethane used as the main material of the polyurethane foam composition according to the present invention uses a conventional expandable polyurethane raw material which can be used as an automotive interior material, and for example, a diisocyanate compound, a polyol, a foaming agent, a catalyst and a surfactant. It can be used a mixed material containing.

Typically, the diisocyanate compound may use methylene diphenyl diisocyanate (MDI) and polymeric methylene diphenyl diisocyanate, and the polyol may be a polypropylene glycol-based material of various kinds. It may be used, but the present invention is not limited thereto.

The polyurethane foam composition according to the present invention may further include foam stabilizers, cell regulators, fillers, pigments or dyes, hydrolysis inhibitors, antistatic agents, colorants, and antifungal agents within a range that does not impair the physical properties, such foamability Additives of polyurethanes are conventional raw materials.

Polyurethane foam composition (or polyurethane foam) of the present invention can be prepared by the above materials and content ratios, and a foam sheet is prepared by mixing a general foam additive with such a polyurethane foam composition and injecting it into a sheet-shaped mold. can do.

Hereinafter, the process of molding the base material of the foam sheet, for example, a vehicle interior material.

First, a resin powder (powder additives such as polypropylene resin) serving as a binder in polypropylene polyol, which is a main raw material of the expandable polyurethane material, and powdered calcium carbonate, expanded graphite, kraft pulp, and short aluminum fibers are mixed in a predetermined amount, respectively. Prepare urethane foam composition.

Mixing of the polyurethane foam composition is carried out using a conventional stirrer (homo mixer), a trace amount of latex and surfactant may be added to increase the dispersibility of the composition.

At this time, the composition content ratio of the polyurethane foam composition and the kind of the mixed material, etc. can be appropriately adjusted according to the automotive interior materials used.

Next, the polyurethane foam composition prepared above is chemically and physically foamed to prepare a foam sheet.

To this end, an additive is further mixed with the polyurethane foam composition, and then it is filled into a moldable mold in a sheet form and the foaming process is performed at 10 to 50 ° C.

As the additive, an additive commonly used in a polyurethane foam such as a curing agent, a curing accelerator, a foaming agent, a flame retardant, a catalyst, a surfactant, and a filler may be used. For example, a curing agent and a foaming agent may be used. The specific composition and content of such additives are not particularly limited in the present invention, and are known to those skilled in the art, and preferably 0.1 to 5 parts by weight based on 100 parts by weight of the expandable polyurethane raw material. do.

Through this process it is possible to obtain a polyurethane foam sheet, wherein the thickness of the foam sheet can be adjusted according to the shape (ie depth) of the mold.

In addition, the foaming process in the mold may be carried out under pressure or vacuum conditions as necessary.

The semi-rigid polyurethane foam sheets prepared as described above are compression molded together with surface protection sheets (e.g. non-woven fabrics) of various materials depending on the use, such as automotive interior materials or interior components, such as automotive seats, door trims, boards, trunk rests, packages Trim, headliner, carpet floor, undercover, hood insulation sound absorbing material, sound absorbing pad for trunk inner cover, engine cover or room insulation or sound absorbing pad, insulation material for automobile engine compartment, dash panel sound absorbing material (Insulation Dash) Panel) can be applied to various parts, such as insulation for sound absorbing material, may have a cross-sectional structure similar to FIG.

Hereinafter, preferred examples are provided to aid in understanding the present invention, but the following examples are provided only for better understanding of the present invention, and the present invention is not limited thereto.

(Example 1)

Methylene diphenyl diisocyanate (4,4'-diphenylmethane diisocyanate, MDI), polypropylene glycol (PPG) in a mixer, polypropylene (PP) powder having a particle diameter of 30 μm with a thermoplastic additive, Then, a foam composition was prepared by mixing calcium carbonate powder and short aluminum fiber, and water was added thereto as a foaming agent to prepare a foam sheet (150 mm thick).

The foam sheet was heated at 200 ° C. for 1 minute before inserting into the mold, and then inserted between upper and lower molds to perform a cold compression process at a pressure of 100 kg / cm 2 at room temperature, and then at room temperature without removing the upper and lower molds. Car interior was prepared by holding for 2 minutes.

(Example 2)

Prepared in the same manner as in Example 1, but was used to prepare a car interior material using polyethylene terephthalate (PET) short fibers of 1.5 denier instead of polypropylene (polypropylene, PP) powder having a particle diameter of 30㎛.

(Example 3)

In the mixer, a foam composition was prepared by mixing polyethylene (PE) powder (particle diameter of 100 μm) with MDI, PPG, and thermoplastic additives, calcium carbonate powder and short aluminum fiber, and adding water as a foaming agent to the foam sheet ( Thickness 200 mm).

The foam sheet was subjected to a compression process by applying a pressure of 100 kg / cm 2 to the upper and lower molds at 200 ° C., and then maintained for 2 minutes without removing the upper and lower molds, and then again subjected to 100 kg / cm 2 at room temperature. After performing the cold compression process, it was maintained for 1 minute to prepare a car interior.

(Example 4)

Prepared in the same manner as in Example 3, but using a PET fiber (2.5 denier) as a thermoplastic additive to prepare a vehicle interior.

(Example 5)

In a mixer, a polycarbonate (polycarbonate, PC) powder (particle diameter 50㎛) was mixed with MDI, PPG, and thermoplastic additives to prepare a foam composition, and water was added thereto as a foaming agent to prepare a foam sheet (thickness 150 mm).

Before the foam sheet is inserted into a mold, it is heated at 100 ° C. for 1 minute, and then inserted between upper and lower molds, and subjected to a compression process by applying a pressure of 100 kg / cm 2 at 200 ° C., and then again 100 kg / After applying a pressure of cm 2 to perform a cold compression process, and maintained for 2 minutes to prepare a car interior.

(Example 6)

Prepared in the same manner as in Example 5, using a PE short fiber (2.5 denier) as a thermoplastic additive to prepare a vehicle interior.

(Comparative Example 1)

Prepared in the same manner as in Example 1, to prepare a car interior without using a thermoplastic additive.

(Comparative Example 2)

Prepared in the same manner as in Example 3, to prepare a vehicle interior without using a thermoplastic additive.

(Comparative Example 3)

Prepared in the same manner as in Example 5, to prepare a car interior without using a thermoplastic additive.

The composition contents used in Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 2 below:

(Experimental Example 1)

The physical properties of the interior specimens obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were measured, and the results are shown in Table 3 below.

(1) Overall Density:

Product weight including skin (surface material) divided by total volume. (Evaluation method: JIS K-6301, unit: kg / ㎥)

(2) Tear Strength

The force required to pull the specimen at a constant speed to break it, typically 0.5 or more. (Evaluation method: JIS K-6301, unit: kg / ㎠)

(3) Hardness

For hardness test, measure 5 places with Type E durometer hardness tester according to KS M 6784 (Verification Test Method for Vulcanized Rubber and Thermoplastic Rubber) and mark it as the median of measured value.

(5) Compression set

Compress the foam sheet at a constant rate and store it for a certain time at a certain temperature and humidity to measure the height of deformation. Commonly used as a measure of the durability of foam sheets. (Evaluation method: JIS K-6301, unit:%)

Referring to Table 3, it can be seen that the interior specimens of Examples 1 to 6 prepared according to the present invention exhibited excellent physical properties in terms of tear strength, hardness, and permanent compression strain compared to the specimens of Comparative Examples 1 to 3. there was.

(Experimental Example 2)

In order to compare the excellent performance of the products prepared in Examples 1 to 6 according to the present invention, the sound absorption and heat resistance were measured, respectively, and compared with Comparative Examples 4 and 5 (the existing products in the market). To this end, the sound absorption and heat resistance performance of each interior specimen were measured by the MS341-12 alpha cabin method, and the results are shown in Tables 5 and 3 and 4 below.

For each interior specimen, sound absorption performance was calculated by measuring the sound absorption coefficient, and heat resistance was measured by thermogravimetric analysis (TGA), and the results are shown in FIGS. 4 and 5, respectively.

Referring to Table 5 and FIGS. 3 and 4, it was confirmed that the interior material specimens of Example 3 prepared according to the present invention were superior in sound absorption and heat resistance performance compared to the specimens of Comparative Examples 4 and 5.

Claims (5)

A polyurethane foam composition for automobile interiors, comprising a mixture of thermoplastic resin powder, calcium carbonate powder and / or expanded graphite powder, kraft pulp powder, and / or short aluminum fibers in an expandable polyurethane raw material.
The method according to claim 1,
The thermoplastic resin powder may be polypropylene resin, epoxy resin, polyethylene resin, polyvinyl chloride, nylon, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polyoxymethylene, polystyrene, ABS resin, teflon resin, phenol resin, melamine Polyurethane foam composition for automobile interior, characterized in that the resin selected from the group consisting of a mixture thereof.
The method according to claim 1,
The thermoplastic resin powder is a polyurethane foam composition for automobile interior, characterized in that mixed in an amount ratio of 5 to 35 parts by weight with respect to 100 parts by weight of the expandable polyurethane.
The method according to claim 1,
The calcium carbonate powder and / or expanded graphite powder is added in an amount of 1 to 12 parts by weight based on 100 parts by weight of the expandable polyurethane, and the kraft pulp powder and / or the short aluminum fiber is 1 to 12 parts by weight based on 100 parts by weight of the expandable polyurethane. Polyurethane foam composition for automobile interior, characterized in that added by part.
The interior material for automobiles, which is manufactured using the polyurethane foam composition according to any one of claims 1 to 4.

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