KR102249763B1 - A floor carpet for automobile having excellent sound-absorbing and sound-blocking properties - Google Patents

Abstract

The present invention relates to a floor carpet for automobiles, and more particularly, by applying a low-density polyurethane foam to the sound-absorbing material and applying a thermoplastic elastomer having a low surface density to the sound-absorbing material, it is lightened to improve vehicle fuel economy, and the physical properties are equivalent. The present invention relates to a floor carpet for automobiles having excellent sound absorption and sound insulation performance while maintaining the above.

Description

A FLOOR CARPET FOR AUTOMOBILE HAVING EXCELLENT SOUND-ABSORBING AND SOUND-BLOCKING PROPERTIES}

The present invention relates to a floor carpet for automobiles, and more particularly, by applying a low-density polyurethane foam to the sound-absorbing material and applying a thermoplastic elastomer having a low surface density to the sound-absorbing material, it is lightened to improve vehicle fuel economy, and the physical properties are equivalent. The present invention relates to a floor carpet for automobiles having excellent sound absorption and sound insulation performance while maintaining the above.

In order to reduce the driving noise of the vehicle, the floor carpet applied to the lower part of the vehicle fills the outer space that can provide comfort to the customer, the sound insulation part that blocks noise and vibration, and the empty space under the vehicle body, secures stepping properties, and absorbs high frequencies. It is composed of a sound-absorbing material part.

The thicker the sound insulation unit, the more effective it is to reduce road noise, making the sound insulation unit thicker, which has been the cause of increasing the weight and price of the vehicle. In addition, the sound-absorbing material part mainly uses felts, but the felts have a high density, so there is a problem of increasing the weight of the parts.

In addition, the sound-absorbing material part is separately foamed and then attached to the fabric part and the sound-insulating material part to form a carpet shape, and the process is complicated and time-consuming.

Conventionally, Korean Patent Registration No. 10-1317819 discloses a floor carpet in which a sound-absorbing layer obtained by mixing a low-melting-point polyester fiber and a hollow polyester fiber as a sound-absorbing layer is applied among carpet fabrics, base papers, and non-woven fabrics. All improvements are not considered, and there is a limit to weight reduction because it is made of felt.

Therefore, in order to improve the problems of the existing floor carpet, research and development of a floor carpet made of a new material capable of simultaneously realizing improved sound absorption and sound insulation performance while reducing weight is required.

Korean Patent Registration No. 10-1317819

In order to solve the above problems, the object of the present invention is to improve NVH (Noise, Vibration, Hardness) performance and reduce weight by applying a low-density polyurethane foam to the sound absorbing material and applying a thermoplastic elastomer with a low surface density to the sound insulating material. Accordingly, it is intended to provide a floor carpet for automobiles that can improve vehicle fuel economy and provide a quietness when driving a vehicle due to excellent sound-absorbing and sound-insulating performance while maintaining equal or higher physical properties.

The present invention relates to a floor carpet for a vehicle including a carpet fabric, a sound-insulating material, and a sound-absorbing material part, wherein the sound-absorbing material is a polyol having a weight average molecular weight of 7000 to 8000 g/mol, a polyol having a weight average molecular weight of 5500 to 6500 g/mol, Polyurethane prepared by directly foaming a raw material composition in which 45 to 55 parts by weight of isocyanate is mixed with 100 parts by weight of a polyol mixture containing an acrylic-styrene copolymer having a weight average molecular weight of 4500 to 5500 g/mol and a foaming agent on the sound insulating material part It is made of foam, and the sound insulation part is made ^{of a thermoplastic elastomer (TPE) having an area density of 500 to 1200 g/m 2} , and the carpet fabric part is made of a nylon film.It provides a floor carpet for automobiles.

The automotive floor carpet according to the present invention improves NVH (Noise, Vibration, Hardness) performance by applying low-density polyurethane foam to the sound-absorbing material and a thermoplastic elastomer with low surface density to the sound-absorbing material, and reducing vehicle fuel efficiency by reducing weight. Can be improved.

In addition, the automotive floor carpet of the present invention has reduced the weight of the parts as a whole, but the physical properties such as hardness, permanent compression reduction ratio, average sound absorption rate, etc. are maintained at the same level or higher, and at the same time, it has excellent sound absorption and sound insulation performance, providing quietness when driving a vehicle. can do.

1 is a rear view of a floor carpet for a vehicle according to the present invention.
2 is a side view of a floor carpet for a vehicle according to the present invention.
3 is a graph showing the results of measuring the sound insulation coefficient of floor carpets for automobiles manufactured in Examples and Comparative Examples of the present invention using an intraluminal method.
4 is a graph showing the results of measuring the sound absorption coefficient of floor carpets for automobiles manufactured in Examples and Comparative Examples of the present invention by using an intraluminal method.
5 is a graph showing the results of measuring the hardness of floor carpets for automobiles manufactured in Examples and Comparative Examples of the present invention.
6 is a graph showing the results of measuring the permanent compression reduction rate of floor carpets for automobiles manufactured in Examples and Comparative Examples of the present invention.
7 is a graph showing the results of measuring the average sound absorption coefficient of floor carpets for automobiles manufactured in Examples and Comparative Examples of the present invention.

Hereinafter, the present invention will be described in more detail with one embodiment.

The present invention relates to a floor carpet for a vehicle including a carpet distal portion, a sound insulation material portion, and a sound absorbing material portion focusing on reduction of driving noise and weight reduction.

More specifically, the sound absorbing material of the floor carpet for automobiles of the present invention is a polyol having a weight average molecular weight of 7000 to 8000 g/mol, a polyol having a weight average molecular weight of 5500 to 6500 g/mol, and a weight average molecular weight of 4500 to 5500 g/mol A raw material composition in which 45 to 55 parts by weight of isocyanate are mixed in 100 parts by weight of a polyol mixture containing a phosphorus acrylic-styrene copolymer and a foaming agent is formed of a polyurethane foam prepared by direct foaming on the sound insulating material part, and the sound insulating material part has an areal density. It is made of a thermoplastic elastomer (TPE) of 500 to 1200 g/m ² , and the carpet fabric is made of a nylon film.

The polyol mixture of the sound-absorbing material part is 37 to 54% by weight of polyol having a weight average molecular weight of 7000 to 8000 g/mol, 10 to 17% by weight of polyol having a weight average molecular weight of 5500 to 6500 g/mol, and 4500 to 5500 g of a weight average molecular weight /mol of the acrylic-styrene copolymer may contain 35 to 40% by weight and 1 to 6% by weight of a blowing agent.

In the polyol mixture, the polyol may be a mixture of polyols having different weight average molecular weights, and the polyol may be polyester-based as its kind.

Specifically, the polyol is a mixture of 37 to 54 wt% of a polyol having a weight average molecular weight of 7000 to 8000 g/mol and 10 to 17 wt% of a polyol having a weight average molecular weight of 5500 to 6500 g/mol to reinforce the resilience of the polyurethane foam. When used, there is an advantage of maintaining high elasticity.

At this time, if the amount of the polyol having a weight average molecular weight of 7000 to 8000 g/mol is less than 37% by weight, elasticity may decrease, and if it exceeds 54% by weight, the foam may become too hard.

In the polyol having a weight average molecular weight of 7000 to 8000 g/mol, hardness may be weakened if the weight average molecular weight is less than 7000 g/mol, and mixing may be difficult if it exceeds 8000 g/mol. Preferably, a polyol having a weight average molecular weight of 7200 to 7800 g/mol, more preferably 7500 g/mol may be used.

In addition, when the weight average molecular weight of the polyol having a weight average molecular weight of 5500 to 6500 g/mol is less than 5500 g/mol, the elasticity may be weakened, and when the weight average molecular weight exceeds 6500 g/mol, a high viscosity mixture may be formed and thus not properly stirred. . Preferably, a polyol having a weight average molecular weight of 5700 to 6200 g/mol, more preferably 6000 g/mol may be used.

The weight average molecular weight of the acrylic-styrene copolymer having a weight average molecular weight of 4500 to 5500 g/mol is added to prevent the hardness of the polyurethane foam from weakening due to the low density, and hardness due to an increase in the hard segment of the benzene structure contained in styrene. It has reinforcing properties and can improve the hardness of polyurethane foam. The acrylic-styrene copolymer may be obtained by copolymerization of 10 to 90% by weight of acrylic and 90 to 10% by weight of styrene. The acrylic-styrene copolymer may be used in an amount of 35 to 40% by weight based on the total polyol mixture, and if the content is less than 35% by weight, there is a problem that the hardness is weakened, and if it exceeds 40% by weight, it is more than the target. It can be cured.

In addition, when the weight average molecular weight of the acrylic-styrene copolymer is less than 4500 g/mol, there is a problem in that the hardness is lowered, and when it is more than 5500 g/mol, the viscosity increases, and thus stirring may be difficult. Preferably, a weight average molecular weight of 4700 to 5300 g/mol, more preferably 5000 g/mol of an acrylic-styrene copolymer may be used.

This sound-absorbing material has the effect of significantly reducing the weight of the carpet and improving the sound-absorbing performance compared to conventional high-density felts by mixing an acrylic-styrene copolymer with polyols having different weight average molecular weights to produce a low-density polyurethane foam. have. In addition, instead of attaching the conventional raw material composition for sound-absorbing material to the sound-insulating material part after separate foaming, the raw material composition can be directly foamed on the sound-insulating material part, thereby reducing the process step and reducing the manufacturing cost.

According to a preferred embodiment of the present invention, the sound insulating material part may be made of a thermoplastic elastomer (TPE) having an ^{area density of 500 to 1200 g/m 2 instead of forming a conventional thick sound insulating material layer.} Since the thermoplastic elastomer is composed of a closed cell and has a characteristic of blocking sound, it has an advantage of excellent sound insulation performance. In particular, the thermoplastic elastomer is used having an areal density of 500 to 1200 g/m ² , and if the areal density is ^{less than 500 g/m 2,} it is formed thin when the distal end is laminated and cannot play a sound insulation role, and 1200 g/m ² If it is exceeded, it may be formed thick and may cause an increase in vehicle weight. The thermoplastic elastomer may be a polyolefin elastomer, an ethylene octane-butane polymer, or a mixture thereof and magnesium hydroxide.

The sound-absorbing material part is made of a thermoplastic elastomer having an area density of 500 to 1200 g/m ² , and the low-density polyurethane foam is applied to the sound-absorbing part to reduce weight while simultaneously improving sound-absorbing and sound-absorbing performance.

According to a preferred embodiment of the present invention, the carpet fabric portion may be made of a nylon film. Due to the foaming pressure in the mold that occurs when the polyurethane foam is fully foamed, there may be a problem in that the polyurethane foam leaks in the fabric with a weak sound insulation part. In the present invention, in order to solve the problem that the polyurethane foam leaks in the direction of the carpet end, a nylon film may be used as the carpet end instead of the base paper. The nylon film is lightweight and has excellent airtightness instead of the existing base fabric used as a finishing material under the fabric, so that when the polyurethane foam liquid is foamed, the polyurethane foam liquid can be prevented from leaking into the fabric.

According to a preferred embodiment of the present invention, the blowing agent may be distilled water.

According to a preferred embodiment of the present invention, the isocyanate may be methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), or a mixture thereof. The sound-absorbing material may be a mixture of 45 to 55 parts by weight of isocyanate to 100 parts by weight of the polyol mixture. At this time, if the content of the isocyanate is less than 45 parts by weight, gelation due to the crosslinking reaction does not occur smoothly, so foam formation may not occur, and if it exceeds 55 parts by weight, the crosslinking is also excessively increased, and cracking of the sound absorbing material may be formed.

According to a preferred embodiment of the present invention, the polyurethane foam of the sound-absorbing material part may implement a low- ^{density polyurethane foam with an apparent density of 70 to 80 kg/m 3.}

According to a preferred embodiment of the present invention, the tunnel portion in which the console is mounted in the floor carpet for an automobile may be sound-absorbed by the sound-absorbing material portion. Since the tunnel part of the existing carpet is finished only with sound-insulating material in consideration of assembly properties, there is a problem that the sound absorption performance is weak. In the present invention, in order to compensate for such a problem, the sound-absorbing performance may be improved by performing a sound-absorbing treatment of the tunnel part of the floor carpet, which is a part where the console is mounted, with a sound-absorbing material part.

According to a preferred embodiment of the present invention, the sound insulating material part is made of a thermoplastic elastomer (TPE), and the carpet end part is made of a nylon film.

1 is a rear view of a floor carpet for a vehicle according to the present invention, and FIG. 2 is a side view of a floor carpet for a vehicle according to the present invention.

Therefore, the floor carpet for automobiles according to the present invention improves NVH (Noise, Vibration, Hardness) performance by applying a low-density polyurethane foam to the sound absorbing material and a thermoplastic elastomer with low surface density to the sound insulating material, and reducing the weight of the vehicle. Fuel economy can be improved.

In addition, the automotive floor carpet of the present invention has reduced the weight of the parts as a whole, but the physical properties such as hardness, permanent compression reduction ratio, average sound absorption rate, etc. are maintained equal or higher, and at the same time, it has excellent sound absorption and sound insulation performance, providing quietness when driving a vehicle. can do.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited by the following examples.

Examples and Comparative Examples

A polyurethane foam was prepared with the components and composition ratios shown in Table 1 below. The density of the prepared polyurethane foam is shown in Table 1. In addition, a thermoplastic elastomer (a mixture of 40% ethylene polymer and 60% magnesium hydroxide) having an area density of 500 g/m ^{2 was prepared as the sound insulation part, and a nylon film was prepared for the carpet fabric part.}

Specifically, a thermoplastic elastomer was thermally pressed to the carpet fabric portion to form a sound insulating material portion. Then, a raw material composition in which the constituents of Table 1 were mixed on the sound-absorbing part was directly foamed at room temperature to prepare a floor carpet for an automobile in which the sound-absorbing part was formed.

Conditions for foaming are mixing with all additives except isocyanate compound and mixing using a mechanical stirrer at 5000 rpm for 20 minutes based on 1500 g, and then adding isocyanate compound and final mixing at 8000 rpm to set a floor carpet fabric. It was poured into a metal mold in the form of a floor carpet set at a temperature of about 50 to 70 °C, sealed, reacted for about 10 minutes, and then demolded after completion of the reaction.

[Ingredients]

(a) Polyol-1: Polyester-based polyol having a weight average molecular weight of 7500 g/mol

(b) Polyol-2: Polyester-based polyol having a weight average molecular weight of 6000 g/mol

(c) acrylic-styrene copolymer: the weight average molecular weight is 5000 g/mol, acrylic

40% by weight and 60% by weight of styrene copolymerized acrylic-styrene copolymer

(d) blowing agent: water (DI-water)

(e) Isocyanate: KW5029, BASF

division Comparative example (mass production PU foam) Example (development PU form) Polyol mixture
(Unit: g) (a) polyol-1 - 35 (b) polyol-2 46 11 (c) acrylic-styrene copolymer 10 30 (d) blowing agent 3.3 3.6 (e) isocyanate BASF_KW5029 Polyol mixture: isocyanate
(Part by weight) 100: 45 100: 48 Apparent density
(kg/m ³ ) 85 75 Measured density
(kg/m ³ ) 89.9 77.7

As can be seen in Table 1, in the case of the Example compared to the Comparative Example, the apparent density ^{was reduced to 75 kg / m 3 It} was confirmed that the polyurethane foam was reduced in weight.

Experimental Example 1

For the floor carpets for automobiles manufactured in the above Examples and Comparative Examples, the sound insulation and sound absorption rates were measured using the in-tube method. The results are shown in Figs. 3 and 4.

3 and 4 are graphs showing the results of measuring sound insulation and sound absorption coefficients of floor carpets for automobiles manufactured in Examples and Comparative Examples of the present invention by using an intraluminal method. 3 and 4, it was confirmed that compared to the comparative example (mass production of SKC PU foam 85K), the Example (development of SKC PU 75K) showed improved values in both sound insulation and sound absorption coefficient.

Experimental Example 2

The hardness, permanent compression reduction rate, and average sound absorption rate of the floor carpets for automobiles manufactured in the above Examples and Comparative Examples were measured using the in-tube method. The results are shown in Figs. 5-7.

5 to 7 are graphs showing results of measuring hardness, permanent compression reduction rate, and average sound absorption rate of floor carpets for automobiles manufactured in Examples and Comparative Examples of the present invention. 5-7, it was found that both the hardness (bearing capacity) and the average sound absorption rate characteristics were improved, and the permanent compression reduction rate was decreased, indicating that the recovery power of the polyurethane foam was reinforced.

Through this, it was confirmed that by applying a low-density polyurethane foam to the sound absorbing material and applying a thermoplastic elastomer with a low surface density, the sound insulation and sound-absorbing performance were improved while maintaining the level of physical properties equivalent to or improved from the existing floor carpet.

Claims (6)

In the floor carpet for automobiles comprising a carpet distal portion, a sound insulating material portion, and a sound absorbing material portion,
The sound-absorbing material includes a polyol having a weight average molecular weight of 7000 to 8000 g/mol, a polyol having a weight average molecular weight of 5500 to 6500 g/mol, an acrylic-styrene copolymer having a weight average molecular weight of 4500 to 5500 g/mol, and a foaming agent. A raw material composition in which 45 to 55 parts by weight of isocyanate are mixed in 100 parts by weight of a polyol mixture is formed of a polyurethane foam prepared by direct foaming on the sound insulating material part,
The sound insulation part is made of a thermoplastic elastomer (TPE) having an area density of 500 to 1200 g/m ^2,
A floor carpet for automobiles having excellent sound absorption and sound insulation performance, characterized in that the carpet fabric portion is made of a nylon film.
The method of claim 1,
The polyol mixture of the sound-absorbing material part is 37 to 54% by weight of polyol having a weight average molecular weight of 7000 to 8000 g/mol, 10 to 17% by weight of polyol having a weight average molecular weight of 5500 to 6500 g/mol, and 4500 to 5500 g of a weight average molecular weight Floor carpet for automobiles comprising 35 to 40% by weight of an acrylic-styrene copolymer of /mol and 1 to 6% by weight of a foaming agent.
The method of claim 1,
Floor carpet for automobiles, characterized in that the foaming agent is distilled water.
The method of claim 1,
The isocyanate is methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), or a mixture thereof, characterized in that the floor carpet for automobiles.
The method of claim 1,
The polyurethane foam of the sound-absorbing material part is a floor carpet for automobiles, characterized in that the ^{apparent density is 70 to 80 kg/m 3.}
The method of claim 1,
A floor carpet for a vehicle, characterized in that the tunnel part on which the console is mounted in the floor carpet for automobiles is sound-absorbed by the sound-absorbing material part.

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