JPS6213907B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molded soundproofing material installed in a vehicle, particularly from a dash panel to a floor of an automobile, and a manufacturing method. More specifically, the present invention relates to an interior soundproofing material for automobile floors having excellent soundproofing properties and a manufacturing method.

Conventionally, a bituminous sheet-like material for the purpose of vibration damping and sound insulation is heat-fused to the floor surface of automobiles using the furnace temperature of the body coating drying oven, and then a carpet is applied on the outfitting line. A laminate has been mounted and used.

From the perspective of resource and energy conservation, there is an urgent need to reduce the weight of vehicles in order to reduce their fuel consumption.
As part of the countermeasures, front engine/front drive systems and the use of aluminum for driving parts are beginning to be adopted, and measures are urgently needed to deal with the noise and transmitted sound that enters the passenger compartment from the front floor area caused by these. It has been demanded. The simplest method to respond to these demands is to increase the thickness of the bituminous damping material that has been used in the past to obtain a sound insulation effect due to the weight effect. This is not desirable in terms of vehicle weight reduction measures.

On the other hand, another method is to replace the backing layer of a tufted carpet with a thin polyethylene layer, which is placed on an automobile floor in combination with a cushioning material, by manufacturing a carpet with a composition consisting of an ethylene-vinyl acetate copolymer and a filler. Attempts have been made to use thicker coatings than conventional ones in the process to ensure a sound insulation effect. However, with this method, the ethylene-vinyl acetate composition will "snake" the pile.
Since it is applied to the back surface of the carpet as a backing material to prevent (falling off), it has many problems as described below. First, the composition must be applied to the entire surface of the carpet in order to prevent "sneak", but in this case, from the standpoint of sound insulation for automobiles, it is not necessarily desirable to have the same film thickness over the entire surface. This is because the thickness of the composition must be matched to the thickness required at the location where sound insulation is required, which only unnecessarily increases the weight of the vehicle. Further, the composition is intended to prevent "sneak", and there is a limit to the amount of filler that can be mixed in, making it difficult to obtain high sound insulation properties, and it is uneconomical due to the large amount of resin. Furthermore, there are problems such as the inability to reuse the cut scraps after cutting them into the required shape, and there is a strong demand for an efficient and economical soundproofing material that satisfies both vehicle weight reduction and high soundproofing properties. There is.

In view of these circumstances, the inventors of the present invention have arrived at the present invention as a result of intensive research. One of the objectives is to satisfy both the weight reduction and high sound insulation properties of a vehicle, and to create an interior floor structure. The object of the present invention is to provide a molded soundproofing material for a vehicle that has excellent moldability, economical efficiency, and fitability as a material, and a second object is to provide a method for producing the molded soundproofing material for a vehicle.

Therefore, the gist of the present invention is (a) thermoplastic resin film lining carpet (b) one or two selected from rubbery materials, bituminous materials, and thermofusible resins. Sound insulating sheet-like material (c) comprising the above and a filler as main components A molded sound insulating material for vehicles made by sequentially laminating and molding cushioning materials such as bulky non-woven fabric or needle felt. c) On the cushion material such as bulky non-woven fabric or needle felt, (b) one or two selected from rubber materials, bituminous materials and thermoplastic resins.
A sound insulating sheet material mainly composed of seeds and a filler is preheated and placed on the sheet material, and (a) a thermofusible resin film lining carpet is placed as a lining of the carpet. A method for manufacturing a molded soundproofing material for a vehicle in which the surface is sequentially placed with or without preheating and then compression molded, further comprising (a) a backing surface of a thermofusible resin film-backed carpet; (c) A filler and one or more selected from rubbery substances, bituminous substances, and thermoplastic resins, which are interposed between a cushion material such as a bulky nonwoven fabric or needle felt. A method for manufacturing a synthetic sound insulating material for a vehicle according to claim 2, wherein the total area of a sound insulating sheet material comprising as a main component is cut in advance into a desired shape that is 30% or more of the carpet area. Exists.

The present invention provides a molded sound insulation material for a vehicle, which is obtained by compression molding a laminate having (a) a carpet as an upper layer, (b) a sound insulating sheet material as an intermediate layer, and (c) a cushion material with sound absorbing properties as a lower layer. It is. (a) The thermoplastic resin film-backed carpet used as the upper layer may be, for example, a polyethylene resin-backed tufted carpet. Synthetic fiber piles are flocked (tacted) onto a coarse base fabric using a flocking machine, and then a thin layer of heat-fused polyethylene is laminated, or polyethylene resin powder is sprinkled and heat-fused to prevent the pile from falling off. It may be a material that is used for automobile floors.

The sound-insulating sheet material used as the intermediate layer of the molded sound-insulating material of the present invention is essential for the structure of the present invention, and not only has high sound-insulating performance, but also has good moldability, flexibility, heat resistance, cold resistance, and stability. It is necessary to have various physical properties such as physical properties. As long as these physical properties are satisfied, natural rubber, various synthetic rubbers,
Selected from rubbery materials such as various recycled rubbers, bituminous materials such as straight asphalt and blown asphalt, and polyethylene, polypropylene, vinyl chloride, vinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, etc. One type or a mixture of two or more types can be used. The fillers to be added to the binder component include calcium carbonate, magnesium carbonate, clay, talc, barium sulfate,
Asbestos etc. can be used. Furthermore, additives such as anti-aging agents, dispersants, and softeners may be added.

The blending ratio of binder and filler is 17:83~
The ratio is 50:50, preferably 25:75 to 35:65. The additives added to the main component, which is a binder and a filler, are added in an amount of 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the main component.

The sound insulating sheet material that can be preferably used as the intermediate layer of the molded sound insulating material of the present invention includes 5 to 30 parts by weight of a thermoplastic resin and a filler based on 100 parts by weight of the rubbery material.
A mixture of 150 to 500 parts by weight, 5 to 20 parts by weight of a tackifying agent, and additives is kneaded and then sheeted. As the tackifying agent, rosin, ester gum, polyterpene resin, petroleum resin, tackifier, etc. can be used.

Other additives that may be mixed include softeners, softeners such as oils, anti-aging agents such as 2.6 tertsyabutyl-di-methylphenol, and stabilizers.

The blending amount of the thermoplastic resin per 100 parts by weight of the rubbery material is preferably 5 to 30 parts by weight; if it is less than 5 parts by weight, moldability and shape retention are poor, and if it is more than 30 parts by weight, problems such as poor restorability will occur. Similarly, rubbery material
The amount of filler added to 100 parts by weight is 150 to 500.
Parts by weight are preferable; less than 150 parts by weight will result in poor sound insulation performance, and more than 500 parts by weight will result in poor flexibility.
This is undesirable because it causes a problem of reduced cold resistance and restorability. The blending amount of the tackifying agent is preferably 2 to 20 parts by weight; if it is less than 2 parts by weight, an adhesive or adhesive film will be required between each laminate, and if it is more than 20 parts by weight, problems will occur in the lamination operation, which is not preferable. The amount of other various additives to be blended is preferably about 2 to 20 parts by weight.

The raw materials are mixed using a kneading machine such as a mixing roll, a Banbury mixer, a kneader, or a co-kneader, then pressed to a desired thickness using a calendar roll, and further cut into a desired shape. The cut waste is recycled.

A sound insulating sheet material having a thickness of about 0.5 to 8 mm and an areal density of about 1 to 10 kg/m ² is preferably used.

It is efficient and preferable that the sound insulating sheet material of the present invention is cut into a shape that corresponds to the shape of the area to which it is applied, with the main focus being on the transmission path for noise from within the engine room. The total area of the sound insulating sheet material to be cut is 30% or more of the area of each part, preferably 60 to 95%.
%. If it is less than 30%, the sound insulation effect cannot be realized.

The cushion material used in the present invention may be a bulky nonwoven fabric or needle felt, and the bulky nonwoven fabric is a mixture of one or more of animal, vegetable, and mineral discontinuous fiber materials and a thermosetting resin. It is mainly composed of a binder consisting of
Although it can be obtained by a method for manufacturing a bulky nonwoven fabric that is known per se, it is important that the binder is almost cured so that it has sound absorbing properties and cushioning properties. The needle felt may be obtained by needle punching a fleece made of one or a mixture of animal, vegetable and mineral discontinuous fiber materials. The thickness of the bulky nonwoven fabric and needle felt in the induced state is 8
~50 mm, and the areal density is preferably in the range of 0.4 to 4 Kg/ ^m2 .

Next, the manufacturing method of the present invention will be explained.

A cushion material such as the above-mentioned bulky nonwoven fabric or needle felt is placed on the bottom surface of a molding die, and then both sides of the sound-insulating sheet are heated with heating means such as a preheating plate (heated iron plate) or a far-infrared lamp. using 80
Preheat at ~200℃ for approximately 15 to 180 seconds and place it on the cushion material, then preheat the carpet backing surface in the same way, or preheat if the shape is small. After placing the sheet so that the backing surface and the sound insulating sheet surface are in contact with each other, the upper mold of the molding mold is immediately lowered, and the cold mold is placed in a zero press state with a pressing force of approximately 1 to 50 kg/cm ² . Hold for 20 seconds to 180 seconds and perform compression molding. After being removed from the mold, the molded soundproofing material for vehicles of the present invention is obtained through final cutting.

The sound insulating sheet material used as the intermediate layer of the present invention may have shredded pieces placed narrowly in a focused manner according to the noise transmission path, or the sound insulating sheet material may be placed narrowly over the entire surface of the component and then placed in a more focused manner. A plurality of shredded pieces may be placed close together.

The molded soundproofing material of the present invention can exhibit excellent soundproofing performance due to the mutually exclusive effect of the soundproofing function of the sheet material and the absorption function of the cushion material. It can be handled efficiently and economically, contributing to the weight reduction of vehicles,
Furthermore, it is possible to use it as it is as a molded interior material. The molded soundproofing material of the present invention can be suitably used for everything from the dash to the front floor.

Examples will be given below to provide a detailed understanding of the present invention. It goes without saying that the present invention is not limited to the following examples.

Example 1 90 parts by weight of vinyl chloride-vinyl acetate copolymer resin,
20 parts by weight of styrene-butadiene rubber, talc
After kneading 270 parts by weight and 30 parts by weight of DOP with a mixing roll, it is passed through a calender roll for about 3 m/min.
A sound insulating sheet material with a thickness of m and an areal density of 43 kg/m ² was obtained.

30 parts by weight of recycled wool and 50 parts by weight of fallen cotton are mixed, sprinkled and mixed with 20 parts by weight of novolak-type powdered phenolic resin with a melting point of 150°C and a curing temperature of 180°C, and after forming into fleece with a fleece forming machine, the mixture is heated to 190°C. A bulky nonwoven fabric having a thickness of 22 m/m and an areal density of 940 g/m ² was obtained through a heating furnace.

A bulky nonwoven fabric is placed on the lower mold of the molding machine, which corresponds to the shape of the car from the front floor to the dash panel.Then, the bulky nonwoven fabric is placed on the lower mold of the molding machine, which corresponds to the shape of the car from the front floor light to the dash panel (corresponding to the area of 76% of the area of the molded product). ) A sound insulating sheet material cut in advance according to the above method is preheated at 110℃ for 2 minutes using an infrared lamp, and then placed on a bulky nonwoven fabric, which is then lined with polyethylene to form a tufted carpet. Immediately after loading, the upper mold was lowered and pressure molding was carried out under a zero press state for 2 minutes at a pressure of 10 kg/cm ² . After taking it out from the mold, it was cut according to the shape from the front floor to the dash panel to obtain a molded soundproofing material for a vehicle according to the present invention.

When the molded soundproofing material for vehicles obtained according to the present invention was installed in a position from the front floor to the dash panel of a front-wheel drive vehicle and the degree of reduction in noise was measured by driving the vehicle, a reduction of approximately 3 dB was observed, indicating that the molded soundproofing material of the present invention is extremely effective. It became clear that it was excellent.

Example 2 100 parts by weight of recycled tire rubber, 18 parts by weight of low density polyethylene powder, 320 parts by weight of heavy calcium carbonate, 13 parts by weight of rosin and 10 parts by weight of process oil were kneaded using a mixing roll, and then passed through a calender roll for about 2 m. A sound insulating sheet material with a thickness of 3.3 kg/m ² and an areal density of 3.3 kg/m 2 was obtained.

30 parts by weight of recycled wool and 50 parts by weight of fallen cotton are mixed, sprinkled and mixed with 20 parts by weight of novolak-type powdered phenolic resin with a melting point of 150°C and a curing temperature of 180°C, and after forming into fleece with a fleece forming machine, the mixture is heated to 190°C. A bulky nonwoven fabric having a thickness of 22 m/m and an areal density of 940 g/m ² was obtained through a heating furnace.

The bulky nonwoven fabric was placed on the lower mold of the molding machine, and then a sound-insulating sheet material cut in advance to match the shape of the car from the front floor to the dash panel was heated at 110°C for 2 hours using an infrared lamp.
After preheating for a few minutes, it was placed on a bulky nonwoven fabric, and then a tufted carpet lined with polyethylene was placed on it, and then the upper mold was immediately lowered to zero with a pressure of 10 kg/cm ² . Pressure molding was performed by maintaining the pressed state for 2 minutes. After taking it out from the mold, it was cut according to the shape from the front floor to the dash panel to obtain a molded soundproofing material for a vehicle according to the present invention.

When the molded soundproofing material for a vehicle obtained according to the present invention was installed in a position from the front floor to the dash panel of a front-wheel drive vehicle and the degree of noise reduction was measured by driving the vehicle, a reduction of approximately 5 dB was observed, indicating that the molded soundproofing material of the present invention is extremely effective. It became clear that it was excellent.

Claims (1)

[Scope of Claims] 1 (a) Thermofusible resin film-backed carpet (b) Mainly comprises one or more selected from rubbery substances, bituminous substances, and thermofusible resins and a filler. Sound-insulating sheet-like material as a component (c) A molded sound-insulating material for vehicles made by sequentially laminating and molding cushioning materials such as bulky nonwoven fabric or needle felt. (c) On a cushion material such as a bulky nonwoven fabric or needle felt, (b) one or more selected from rubbery substances, bituminous substances, and thermoplastic resins and a filler are mainly used. A sound insulating sheet material as a component is preheated and placed on the sheet material, and (a) a thermofusible resin film lining carpet is preheated on the backing surface of the carpet, or A method for manufacturing a molded soundproofing material for a vehicle, characterized in that the molded soundproofing material for a vehicle is sequentially placed without being added, and then compression molding is added. 3. Rubbery substances, bituminous substances, and thermoplastic materials interposed between (a) the backing surface of the thermoplastic resin film-backed carpet and (c) cushion materials such as bulky nonwoven fabrics or needle felts. A sound insulating sheet material mainly composed of one or more resins selected from resins and a filler is preliminarily cut into a desired shape with a total area of 30% or more of the carpet area. A method for manufacturing a molded soundproofing material for a vehicle according to claim 2.