JP2005289125A - Automobile fiber mat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automobile fiber mat capable of damping sound energy by consuming that as frictional heat when sound passes through open-cell while colliding, and having excellent sound absorbing performance. <P>SOLUTION: The automobile fiber mat is equipped with a foam sound absorbing material made from a foam forming element, backings having polyethylene as the main ingredient formed on both sides of the foam sound absorbing material; and a skin layer formed on the surfaces of the backings on both surfaces. As the foam forming element, an additive having activating components for increasing dipole moment amount in a base resin is combined by a ratio of 10 to 200 pts.wt. for the base resin 100 pts.wt. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an automotive fiber mat laid in a vehicle interior of an automobile, and more particularly, to an automotive fiber mat that can effectively absorb sound generated from inside and outside the vehicle.

  As a constituent material of a conventional automobile mat, it has been produced by providing a fiber sheet on one surface of a resin sheet such as a thermoplastic resin, a thermoplastic elastomer, a thermosetting resin, or natural rubber or synthetic rubber.

  Examples of the resin sheet include thermoplastic resins (eg, polyvinyl chloride, ethylene-vinyl acetate copolymer, polyethylene, etc.), thermoplastic elastomers (eg, styrene thermoplastic elastomer, polyolefin thermoplastic elastomer, polyvinyl chloride). Elastomers), thermosetting resins (eg, phenol resins, polyurethane, unsaturated polyester resins, etc.), or natural rubber or synthetic rubber (eg, styrene-butadiene rubber, butadiene rubber, isoprene rubber, nitrile-butadiene rubber, etc.) Can be mentioned.

  Examples of the fiber sheet include tufted carpet, needle punched carpet, stepping, hook carpet, Wilton carpet, and Akisminster carpet (see Patent Document 1).

  As apparent from the fact that such a fiber mat for automobiles uses a resin sheet in its configuration, the category as the sound damping performance is the sound insulation performance. Therefore, this fiber mat for automobiles can effectively block the sound in the vehicle transmitted through the floor steel plate of the automobile.

  However, this automobile fiber mat has the following problems with respect to the sound that directly enters the vehicle from the outside. In other words, the sound insulation performance basically prevents sound from passing through to the opposite side of the sound insulation material by reflecting the sound. In other words, no mitigating means is provided for the sound source side. Therefore, for example, when sound enters the vehicle directly, such as wind noise generated when a car window is slightly opened, the sound is reflected by the fiber mat for the car and becomes noisy.

In addition, since the conventional fiber mat for automobiles uses a sheet made of a lump of resin as described above, there is a disadvantage that it is very heavy.
JP 2002-356124 A

  Therefore, the present invention has been made in view of the above problems, and when sound energy is applied, the sound is consumed as frictional heat when passing through the inside of the open cell while colliding with the sound. An object of the present invention is to provide an automotive fiber mat excellent in sound absorbing performance.

  The present invention includes a foamed sound absorbing material made of a foamed molded article and skin layers formed on both surfaces of the foamed sound absorbing material.

  The skin layer is not limited and may be a woven fabric, a non-woven fabric, or a tufted tone in which pile fibers are planted. This skin layer may be provided with a backing layer for stabilizing the shape of a nonwoven fabric or the like. For the backing layer, a thermoplastic resin mainly composed of polyethylene is preferably used. This backing may be formed by softening a polyethylene sheet previously formed into a sheet shape by heat, or the melted polyethylene may be directly molded into a sheet shape.

  The foamed sound-absorbing material of the present invention comprises a foamed molded product, and the foamed molded product contains 10 to 200 parts by weight of an active ingredient that increases the amount of dipole moment in the foamed molded product. It is characterized by being blended at a ratio of parts.

  This foam molded article is made of polyurethane, polyvinyl alcohol, polyvinyl chloride, chlorinated polyethylene, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polymethyl methacrylate, polystyrene, styrene-butadiene-acrylonitrile copolymer, polyvinyl formal, Polymers such as epoxy, phenol, urea, silicon, or acrylic rubber (ACR), acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), butadiene rubber (BR), natural rubber (NR), isoprene rubber ( IR), rubber polymers such as chloroprene rubber (CR) are used as the base resin, and these are conventionally known bubble generation means, that is, bubble generation means using a pyrolytic foaming agent, bubble generation using a volatile solvent Means, or under high pressure The active gas is absorbed in a polymer obtained by foam molding using a bubble generating means and the like to foam at atmospheric pressure.

Moreover, a thermoplastic engineering plastic can also be used as a foaming molding. For example, polyacetal (POM), polyamide (PA), ethylene vinyl acetate (EVA), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), syndiotactic polystyrene (SPS),
Polyphenylene sulfide (PPS), polyether ether ketone (PEEK), liquid crystal polymer (LCP), fluororesin, polyether nitrile (PEN), polycarbonate (PC), modified polyphenyl ether (mPPE), polysulfone (PSF), polyether Examples thereof include one or more selected from the group consisting of sulfone (PES), polyarylate (PAR), polyamideimide (PI), polyetherimide (PEI), and thermoplastic polyimide (PI).

  In selecting the polymer constituting the foamed molded product, in addition to the amount of dipole moment inside the molecule described later, handleability, availability, temperature performance (heat resistance and cold resistance), price, and the like are also considered. Is desirable.

  The foaming ratio of the foamed molded product is arbitrary, and may be appropriately determined depending on the use and application location of the foamed sound absorbing material, the level of performance for which countermeasures are required, and preferably 5 to 50 times, more preferably 10 to 30 times. This is because when the expansion ratio is less than 5 times, energy consumption in the bubbles inside the foam described later is reduced, and the sound absorption performance is remarkably deteriorated. When the expansion ratio is more than 50 times, the foam is expanded. This is because the mechanical strength as a sound-absorbing material is reduced, making it difficult to use as a fiber mat for automobiles.

  Also, regarding the number of cells and bulk density in the foam molded article, the larger these values, the greater the energy consumption and the sound absorption performance. It is good to decide appropriately according to.

  The structure of the foamed molded product is, in principle, an open-cell type, but it is independent depending on the use and application location of the foamed sound-absorbing material and the type of sound (high-frequency sound or low-frequency sound) that requires sound absorption performance There may be a bubble type.

  The foamed sound-absorbing material of the present invention is obtained by blending an additive composed of an active ingredient that increases the amount of dipole moment in the foamed molded article. The first sound absorbing mechanism in the foamed sound absorbing material in the present invention is that when sound is transmitted to the foamed sound absorbing material, the air vibration is transmitted to the air in the bubble part inside the sound absorbing material, and viscous friction of air occurs in this bubble part, The sound absorption performance is obtained by returning part of the sound energy to heat energy.

  The second sound absorption mechanism focuses on the dipole in the foamed molded body that constitutes the foam sound absorbing material, and the sound energy is consumed due to the displacement of the dipole and the restoring action of the dipole, resulting in sound absorption performance. It is.

  This second mechanism will be described in further detail. It can be said that the arrangement of the dipoles inside the foamed molded product is in a stable state at the beginning. However, when air-borne sound (sound energy) is transmitted, each dipole in the foamed molded body is placed in an unstable state, and each dipole attempts to return to the initial stable state. At this time, sound energy is consumed. It is considered that sound absorption performance is produced through the energy consumption of sound due to the displacement of the dipole inside the foamed molded body and the restoring action of the dipole. In the foamed molded product, the sound energy consumption due to the viscous friction of air in the above-mentioned bubble part, the displacement of the dipole inside the foamed molded product, and the sound energy consumption due to the restoring action of the dipole cooperated, and excellent Sound absorption performance is considered to be demonstrated.

  The active ingredient blended in the additive is a component that dramatically increases the amount of dipole moment in the foamed molded article, and the active ingredient itself has a large amount of dipole moment, or the active ingredient itself. Although the amount of dipole moment is small, it refers to a component that can dramatically increase the amount of dipole moment in the foamed molded product by blending the active ingredient.

  Examples of active ingredients having such effects include N, N-dicyclohexylbenzothiazyl-2-sulfenamide (DCHBSA), 2-mercaptobenzothiazole (MBT), dibenzothiazyl sulfide (MBTS), N- Cyclohexylbenzothiazyl-2-sulfenamide (CBS), N-tert-butylbenzothiazyl-2-sulfenamide (BBS), N-oxydiethylenebenzothiazyl-2-sulfenamide (OBS), N , N-diisopropylbenzothiazyl-2-sulfenamide (DPBS) and the like, which are composed of one or more selected from compounds containing a benzothiazyl group.

  2- {2'-Hydroxy-3 '-(3 ", 4", 5 ", 6" tetrahydrophthalimide in which a benzotriazole having an azole group bonded to a benzene ring is used as a mother nucleus and a phenyl group is bonded thereto. Methyl) -5'-methylphenyl} -benzotriazole (2HPMMB), 2- {2'-hydroxy-5'-methylphenyl} -benzotriazole (2HMPB), 2- {2'-hydroxy-3'-t- Such as butyl-5'-methylphenyl} -5-chlorobenzotriazole (2HBMPCB), 2- {2'-hydroxy-3 ', 5'-di-t-butylphenyl} -5-chlorobenzotriazole (2HDBPCB) There are one or more selected from compounds having a benzotriazole group.

  There are those composed of one or more selected from compounds containing a diphenyl acrylate group such as ethyl-2-cyano-3,3-di-phenyl acrylate.

  Alternatively, one or more selected from compounds having a benzophenone group such as 2-hydroxy-4-methoxybenzophenone (HMBP) and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (HMBPS) is there.

  As a compounding quantity of the above-mentioned active ingredient, the ratio of 10-200 weight part is preferable with respect to 100 weight part of foaming moldings. For example, when the amount of the active ingredient is less than 10 parts by weight, a sufficient effect of blending the active ingredient to increase the amount of dipole moment cannot be obtained, and the amount of the active ingredient is 200 parts by weight. This is because the polymer constituting the foamed molded product and the active ingredient may not be sufficiently compatible with each other.

  In determining the active ingredient contained in the foam molded article, considering the ease of compatibility of the active ingredient and the polymer constituting the foam molded article, that is, the SP value, and selecting the one with a close value good.

  The amount of dipole moment varies depending on the type of polymer and active component constituting the foamed molded article. Even if the same component is used, the amount of dipole moment varies depending on the temperature at which energy is transmitted. The amount of dipole moment varies depending on the magnitude of energy. For this reason, in consideration of the temperature and energy level when applied as a foam sound absorbing material, the polymer and active components that make up the foamed molded product are selected so that the maximum dipole moment is obtained. It is desirable to use.

  According to the fiber mat for automobiles of the present invention, in addition to the sound absorption performance due to the consumption of sound energy due to the viscous friction of air in the bubble portion, which is the conventional sound absorption mechanism, the displacement of the dipole and the restoration of the dipole inside the foamed molded product The energy consumption of the sound due to the action cooperates, and an excellent sound absorbing performance can be exhibited.

  Further, since the sound absorbing performance is excellent, the noise transmitted from the outside of the vehicle to the inside of the vehicle can be effectively absorbed by the mat, and it can be prevented from reverberating inside the vehicle.

  Furthermore, since a heavy sheet material such as PVC is not disposed, the vehicle mat can be very light.

  Next, examples of the present invention will be described.

  FIG. 1 shows a side sectional view of an embodiment of the present invention.

The base fabric is a 1330-tex polyethylene terephthalate fiber, a needle punched nonwoven fabric is obtained with a basis weight of 110 g / m ² , and a 1330-tex polypropylene fiber having a length of 30 mm is used as the pile fiber. Ted carpet. As the foamed sound absorbing material, a foamed molded article having a continuous pore size of 10 mm was obtained by adding 3 parts by weight of DCHBSA as an additive to ethylene vinyl acetate as a base resin and 100 parts by weight of the base resin, and foaming 30 times. . And the base fabric was lined up on both surfaces of the foam sound-absorbing material, and the fiber mat for cars was obtained.

    In Comparative Examples 1 and 2, a base cloth is formed on only one side of a foamable sound absorbing material as shown in FIG.

  Table 1 shows the measurement results of the normal incidence sound absorption coefficient in each frequency band of Example 1, Comparative Example 1, and Comparative Example 2. In Comparative Example 1, the sound source was measured on the base fabric side and measured, and in Comparative Example 2, the sound source was provided on the foamed sound absorbing material side. The test conditions were JIS-A-1405.

表１より、周波数２０００以上において、比較例１と比較して垂直入射吸音率が低下し、８００〜１６００Ｈｚの間においては、比較例２より劣るものの、その他の領域では、実施例が高い垂直入射吸音率を示しており、また、全体的に安定して高い吸音率を示していることがわかる。

From Table 1, the normal incident sound absorption coefficient is lower than that of Comparative Example 1 at a frequency of 2000 or higher, and is inferior to that of Comparative Example 2 between 800 and 1600 Hz. The sound absorption coefficient is shown, and it can be seen that the sound absorption coefficient is stable and high overall.

It is a figure which shows the cross section of the fiber mat for motor vehicles based on Example 1. FIG. It is a figure which shows the cross section of the fiber mat for motor vehicles which concerns on the comparative examples 1 and 2. FIG.

Claims (7)

A foam sound-absorbing material comprising a foamed molded article, and a skin layer formed on both surfaces of the foam sound-absorbing material,
The foamed molded article is characterized in that an additive having an active ingredient that increases the amount of dipole moment is blended in the base resin at a ratio of 10 to 200 parts by weight with respect to 100 parts by weight of the base resin. Fiber mat for automobiles. The base resin constituting the foamed molded article is polyurethane, polyvinyl alcohol, polyvinyl chloride, chlorinated polyethylene, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polymethyl methacrylate, polystyrene, styrene-butadiene-acrylonitrile copolymer. , Polyvinyl formal, epoxy, phenol, urea, silicone, acrylic rubber (ACR), acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), butadiene rubber (BR), natural rubber (NR), isoprene rubber (IR) 2) A fiber mat for automobiles according to claim 1, which is one or a mixture of two or more selected from chloroprene rubber (CR). The base resin of the foam molded article is polyacetal (POM), polyamide (PA), ethylene vinyl acetate (EVA), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), syndiotactic polystyrene (SPS),
Polyphenylene sulfide (PPS), polyether ether ketone (PEEK), liquid crystal polymer (LCP), fluororesin, polyether nitrile (PEN), polycarbonate (PC), modified polyphenyl ether (mPPE), polysulfone (PSF), polyether It is characterized by comprising one or more selected from the group of sulfone (PES), polyarylate (PAR), polyamideimide (PI), polyetherimide (PEI), and thermoplastic polyimide (PI). The fiber mat for automobiles according to claim 1. The fiber mat for automobiles according to any one of claims 1 to 3, wherein the additive is one or more selected from compounds containing a benzothiazyl group. The automotive fiber mat according to any one of claims 1 to 3, wherein the additive is one or more selected from compounds having a benzotriazole group. The automotive fiber mat according to any one of claims 1 to 3, wherein the additive is one or more selected from compounds having a diphenyl acrylate group. The automotive fiber mat according to any one of claims 1 to 3, wherein the additive is one or more selected from compounds having a benzophenone group.

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