KR20060003276A - Sound-absorbing material for interior of automobile - Google Patents

Abstract

The present invention relates to a sound absorbing material for automobile interior, comprising: a felt in which at least one of natural fibers, recycled fibers, polyolefin-based virgin fibers, and inorganic fibers is mixed in a predetermined ratio; It is made of at least one of hexaprephenol, melamine, epoxy, unsaturated polyester, epoxy-polyester, phenol and epoxy-polyester, characterized in that it comprises a powdery curing agent mixed with the felt to bind and cure the felt . Accordingly, there is provided a sound absorbing material for automobile interiors that can improve the moldability and workability of the sound absorbing material, improve the working environment, and reduce the sensory discomfort caused by the odor and harmful components generated in the sound absorbing material.

Description

Sound absorbing material for automobile interiors {SOUND-ABSORBING MATERIAL FOR INTERIOR OF AUTOMOBILE}

The present invention relates to a sound absorbing material for automobile interiors.

Background Art Conventionally, resin felts, urethane foams, PET felts, etc., made of a phenol resin as a curing agent have been used as sound absorbing materials for automobile interiors.

On the other hand, resin felt containing phenolic resin as curing agent is decomposed by amine amine when it is cured, and by-products of amine and ammonia are generated, which is harmful to human body. There is a problem that causes the sensual discomfort of the consumer by the ingredients.

In the case of urethane foam, the weight is heavier and more expensive than other materials, and it is difficult to generate and recycle dioxin during combustion.

In the case of PET felt, combustibility and sound absorption are poor as a single material, and in the case of felt using recycled fibers, the felt is manufactured by mixing wool in recycled fiber felt to improve the combustibility. Due to the rise, the competitiveness is inferior.

In addition, epoxy and unsaturated polyester, which are thermosetting resins, which are used as conventional curing agents, are formed in a liquid phase, and there is a problem in that moldability and workability are deteriorated.

Accordingly, the present applicant improves the moldability and workability of the sound absorption, improves the working environment by suppressing the generation of scattering dust and harmful substances in the manufacturing process, and reduce the sensory discomfort caused by the smell and harmful components generated in the sound absorbing material The company has developed a sound absorbing material for automobile interiors.

Accordingly, it is an object of the present invention to improve the moldability and workability of the sound absorbing material, to improve the working environment, and to provide a sound absorbing material for automobile interiors which can reduce the sensory discomfort caused by the odor and harmful components generated in the sound absorbing material. .

In order to achieve the above object, the present invention, in the sound absorbing material for automobile interior, at least any one of natural fibers, recycled fibers, polyolefin-based virgin fibers, inorganic fibers and the like; It is made of at least one of hexaprephenol, melamine, epoxy, unsaturated polyester, epoxy-polyester, phenol and epoxy-polyester, characterized in that it comprises a powdery curing agent mixed with the felt to bind and cure the felt It provides a sound absorbing material for automobile interior.

Here, it is preferable that it consists of 80 to 90 weight% of the said felts, and 10 to 20 weight% of the said hardening | curing agents.

It is more effective that the mixing ratio of the felt consists of 80 to 90% by weight of recycled fibers and virgin fibers, which are cotton and chemical fibers, and 10 to 20% by weight of hemp and inorganic fibers.

The particle size distribution of the curing agent is 10 to 200 μm, and the average particle size is 20 to 80 μm, thereby improving dispersibility when mixing the curing agent with the felt, thereby increasing the binding force of the felt.

It is preferable that the hexaprephenol of the said hardening | curing agent is 0.2% or less of an ammonia component.

On the other hand, it is preferable that the molding thickness of the said felt is 5-30 mm.

It is more effective that the surface density of the said felt is 350-2000 g / m <^2> .

Hereinafter, the present invention will be described in detail with reference to preferred embodiments.

The sound absorbing material for automobile interiors according to the present invention includes a felt and a powdery curing agent mixed with the felt to bind and cure the felt. Here, it is preferable that the sound absorbing material for automobile interiors is mixed in the ratio of 80 to 90 weight% of felt, and 10 to 20 weight% of hardening | curing agents.

Felt is made of a mixture of at least one of natural fibers, recycled fibers, polyolefin-based virgin fibers, inorganic fibers.

As the natural fiber, cotton, wool, jute, flax, low hemp, hemp, sisal hemp, coconut or the like is preferably used.

As the recycled fiber, polypropylene such as industrial waste or scrap generated in the process, polyester, nylon, vinylon fiber and the like are preferably used. Thus, waste resources can be used to prevent environmental pollution due to incineration or landfill, saving resources and achieving economic effects.

As the inorganic fiber, glass fiber, carbon fiber, or the like can be used.

Here, it is more effective that the felt is mixed at a ratio of 80 to 90% by weight of cotton, which is a natural fiber, recycled and virgin fibers, and 10 to 20% by weight of hemp and inorganic fibers. And the felt may consist of a single fiber.

On the other hand, the molding thickness of the felt is preferably 5 to 30 mm. If the molding thickness of the felt is less than 5mm, the strength and sound absorption performance is inferior, and if the molding thickness of the felt exceeds 30mm, the strength and sound absorption performance for the thickness is good, but it is not preferable because the dimensional and shape stability at the time of attachment. Therefore, the molding thickness of the felt used as the sound absorbing material for automobile interior is preferably in the range of 5 to 30 mm, more particularly in the range of 10 to 25 mm.

And it is preferable that the surface density of a felt is 350-2000 g / m <^2> . If the surface density of the felt is less than 350g / m ² , the sound absorption performance, strength, stability of the form is inferior, if more than 2000g / m ² , the sound absorption performance is improved, but the weight per unit area is not preferable because the weight of the product is deteriorated. Therefore, the surface density of the felt is preferably in the range of 350 to 2000 g / m ² , and more particularly in the range of 400 to 1500 g / m ² .

A hardening | curing agent consists of a powder form and improves the moldability and workability of a sound absorption material. The curing agent preferably consists of at least one of hexa free phenol, melamine, epoxy, unsaturated polyester, epoxy-polyester, phenol and epoxy-polyester, and especially hexaprephenol has ammonia content of 0.2% or less. Is more effective. Here, the curing agent may be made of a single resin.

Moreover, it is preferable that a hardening | curing agent melts and hardens at 50-200 degreeC, and when it is 95%, it is more effective that a pyrolysis start temperature is 170 degreeC.

On the other hand, in order to improve the kneading property between the curing agent and the felt, the particle size distribution of the curing agent is preferably distributed within the range of 1 to 250 μm, the particle size distribution is 10 to 200 μm, and the average particle size is more preferably 20 to 80 μm. effective. When the particle size distribution of the curing agent is 200 µm or more and the average particle size is 80 µm or more, it is not preferable because dispersibility is poor due to specific gravity difference when kneading with the felt.

Therefore, the curing agent has the ability to adhere to the surface of the fibers constituting the felt when kneading with the felt to improve the dispersibility, and to improve the bonding between the fibers during molding, generation of scattering dust and harmful substances during the manufacturing process of the sound absorbing material This can be reduced, and the working environment can be improved.

Hereinafter will be described a method of manufacturing a sound absorbing material for automobile interior according to the present invention.

First, natural fibers, recycled fibers, virgin fibers, inorganic fibers and the like are mixed in a predetermined ratio to prepare a felt.

Next, the powdery curing agent is mixed with the felt and opened.

The opened felt is then cured in an oven at a constant temperature and then cooled to maintain the shape of the felt.

After the cooled felt is cut to fit the product shape, the cut felt is heated and press-molded according to the shape to complete manufacture of the sound absorbing material for automobile interior according to the present invention.

On the other hand, the following shows the results of the various tests for the sound absorbing material for automobile interior according to the present invention.

First, through the quantitative analysis of the curing agent, phenols that are used in the past and phenols having reduced harmfulness, that is, hexaprephenol (0.2% or less of ammonia), were tested through the quantitative analysis of Table 1 below.

Table 1 Quantitative Analysis Results

Table 2 shows the test results for determining the optimum powder resin size when mixed with the felt through the particle size analysis of the curing agent.

[Table 2] particle size analysis results of the curing agent

On the other hand, Table 3 shows a test method for the sound absorbing material for automobile interior.

[Table 3] Test Method for Sound Absorbing Materials for Automobile Interiors

Example One

Table 4 shows the test results for the types of curing agents mixed in the felt according to the test method in Table 3. The test piece in Table 4 was molded at a surface density of 750 g / m ² with a molding thickness of 10 mm, preheating temperature of 280 to 350 ° C, and preheating time of 10 to 45 sec.

[Table 4] Test results by type of curing agent at surface density of 750 g / m ² and thickness of 10 mm

Example 2

Graph 1 and Graph 2 show the results of testing the sound absorption rate using the improved phenol resin (hexaprephenol). This is a result of testing the sound absorption rate according to the thickness change and the surface density change when the resin content is 10 to 20% by weight of the curing agent.

[Graph 1]

Sound absorption test result according to surface density change when thickness is 18mm (surface density: 1500, 1800,2000g / m ² )

[Graph 2]

Sound absorption test results according to the thickness change when the surface density is 1500g / m ² (thickness: 8, 10, 12, 14, 16, 18, 20mm)

Graph 1 and Graph 2 show the results of the test according to the test method of ASTM E 1050 using a vertical incidence sound absorption tester (Two-microphone impedace measurement tube), the sample is a non-woven fabric (100g / m ² ) above and below the felt This is the result of laminating and testing.

Comparative example One

Table 5 shows the results of quantitative analysis of the existing phenols and phenols with reduced hazards, that is, hexaprephenol. As shown in Table 5, the content of phenol, phenol, formalin, and hexamethylenetetramine, which can be detected in phenol, is compared.

Table 5 Quantitative Analysis Results

Comparative example 2

Table 6 shows the results of the thermal analysis equipment DSC (Differential Scanning Calorimeter), TGA (Thermogravicmetric Analyzer) to determine the melting temperature and thermal properties of the curing agent. DSC was used to compare the melting temperature, crystallization temperature, and heat capacity of each curing agent. Table 6 shows the thermal decomposition initiation temperature and residues using TGA.

[Table 6] Thermal Analysis Test Results by Curing Agent Type

As shown in Table 6, crystallization was observed in the region of 150 ° C. in the case of the existing phenol, and crystallization temperature was not observed in the case of phenols having reduced harmfulness. Thermal stability was lower than that of conventional phenol at 95% of pyrolysis initiation, and it was observed that epoxy polyester melted at 70 ° C. TGA resulted in less residue and 95% of pyrolysis initiation temperature. Was significantly higher than the existing phenols, which showed excellent thermal stability.

Thus, hexaprephenol, melamine, epoxy, unsaturated polyester, epoxy-polyester, phenol and epoxy- in felt mixed with at least one of natural fiber, recycled fiber, polyolefin virgin fiber and inorganic fiber in a certain ratio. By including a powdery curing agent made of at least one of polyester, it is possible to improve the moldability and workability of the sound absorbing material, improve the working environment, and to reduce the sensory discomfort caused by the odor and harmful components generated in the sound absorbing material.

As described above, according to the present invention, there is provided a sound absorbing material for automobile interior which can improve the moldability and workability of the sound absorbing material, improve the working environment, and reduce the sensory discomfort caused by the odor and harmful components generated in the sound absorbing material. do.

Claims (7)

In the sound absorbing material for automobile interiors, A felt in which at least one of natural fibers, recycled fibers, polyolefin-based virgin fibers, and inorganic fibers is mixed at a predetermined ratio; It is made of at least one of hexaprephenol, melamine, epoxy, unsaturated polyester, epoxy-polyester, phenol and epoxy-polyester, characterized in that it comprises a powdery curing agent mixed with the felt to bind and cure the felt Sound absorbing material for automobile interior. The method of claim 1, A sound absorbing material for automobile interiors, comprising 80 to 90% by weight of the felt and 10 to 20% by weight of the curing agent. The method according to claim 1 or 2, The mixing ratio of the felt is 80 to 90% by weight of the recycled fibers and virgin fibers of cotton and chemical fibers, 10 to 20% by weight of hemp and inorganic fibers. The method according to claim 1 or 2, The particle size distribution of the said hardening | curing agent is 10-200 micrometers, and the average particle size size is 20-80 micrometers, The sound absorption material for automotive interiors. The method of claim 1, Hexaprephenol of the said hardening | curing agent is a sound absorption material for automobile interiors characterized by the ammonia component being 0.2% or less. The method of claim 1, The molding thickness of the felt is 5 to 30mm, interior sound absorbing material for automobiles. The method of claim 1, The surface density of the felt is 350 to 2000g / m ^{2 The} sound absorbing material for automobile interior.