KR102575776B1 - Sound absorbing and insulating material for automobile engine encapsulation - Google Patents

Abstract

It relates to a sound-absorbing insulation material for automobile engine encapsulation. Specifically, it is formed of multiple layers including a polymer resin layer, a polyurethane foam layer, a silica airgel layer, and an aluminum sheet layer, but its volume is not large, which improves adhesion and generates high temperatures. It relates to a sound-absorbing insulation material for car engine encapsulation that can also be applied to engines and exhibits improved insulation and sound absorption effects by applying closely to the engine to more efficiently reduce heat energy and noise emitted to the outside of the engine.

Description

Sound absorbing and insulating material for automobile engine encapsulation}

The present invention relates to a sound-absorbing insulation material for automobile engine encapsulation, which effectively reduces noise and heat energy generated from the automobile engine, exhibits improved insulation and sound absorption effects, and can be applied closely to the engine. It relates to sound-absorbing insulation materials for encapsulation.

In general, in the engine room of a car, not only noise caused by the operation of the engine for driving or the operation of the air conditioning system, but also noise flowing into the engine room from the outside of the car occurs. The noise generated in this way is transmitted to the interior of the car and acts as a factor in deteriorating ride comfort.

Therefore, engine encapsulation technology, a structure that surrounds the engine and reduces noise, is being developed. Figure 1 is a reference diagram for explaining the engine encapsulation concept. Car body shaped encapsulation is a concept of encapsulating the entire engine room by attaching members to the surface of the car body according to the shape of the car body within the engine room. Mid-field encapsulation is a concept of encapsulating the engine (including attached exhaust system parts) and transmission in the middle of the powertrain and vehicle body. This is a concept that improves performance, layout, cost, and weight. Near-field encapsulation is a complex encapsulation concept for optimization, and near-field encapsulation is a concept of encapsulation by attaching the encapsulation member directly to the surface of the engine and transmission. Because it is attached, noise generated from the engine can be absorbed more efficiently.

However, in the case of near-field encapsulation, there are difficulties in configuring the layout and adhesion due to the various structures and arrangements of the engine, transmission, and its accessory parts, and furthermore, the closer it is to the noise source of the engine, the closer it is to the heat source, so it can be used in a high temperature environment of over 200℃. Since it is possible to maintain its shape, the heat resistance required increases due to its function as a sound absorbing material, and the requirement for flame retardancy increases due to the risk of fire, so sound absorption as well as insulation performance are required.

In addition, when the weight of the encapsulated sound-absorbing insulation material is increased to implement the sound-absorbing insulation performance, the fuel efficiency of the vehicle decreases due to the increase in the weight of the vehicle, and there is a limit to the sound absorption and insulation performance that can be improved.

Therefore, sound-absorbing insulators containing polyurethane foam with soundproofing properties and fine glass fibers with heat-insulating properties are being used as sound-absorbing insulators that can be attached in close contact with the engine and are lightweight.

Korean Patent No. 10-0238549 (announced on January 15, 2000) relates to a method of manufacturing soundproofing and heat insulating materials for automobiles. Polyurethane and glass fiber, each of which is thin but molded at high density, are overlapped and the top and bottom of them are It is disclosed that noise and high heat generated from a car engine can be blocked by overlapping flame retardant materials such as non-woven fabric or aluminum foil.

However, in the case of glass fiber, the tissue bond is weak, so it is easily torn, and the radiation of the glass fiber exposed to the outside during use is very harmful to health and causes industrial pollution. In the case of polyurethane, there are limitations in physical properties and sound absorption, so polyurethane is glass. It is difficult to obtain a satisfactory sound absorption and insulation effect simply by overlapping with fibers, and in particular, it is difficult to achieve a satisfactory sound absorption rate for airborne noise, which accounts for the largest proportion of automobile noise in the high range.

Therefore, the present invention seeks to improve these problems and provide a sound-absorbing insulation material for automobile engine encapsulation that can be closely applied to automobile engines.

Korean Patent No. 10-0238549 (announcement date: January 15, 2000)

The problem of the present invention is to provide a sound-absorbing insulation material for car engine encapsulation that can be closely applied to the car engine and can more effectively reduce heat energy and noise emitted outside the engine, thereby providing improved insulation and sound absorption effects. .

The present invention relates to a polymer resin layer made of a polymer resin; A polyurethane foam layer laminated on top of the polymer resin layer; A silica airgel layer laminated on top of the polyurethane foam layer; and an aluminum sheet layer laminated on top of the silica airgel layer. It provides a sound-absorbing insulation material for automobile engine encapsulation, characterized in that it is made of multiple layers, including.

In one embodiment, a binder layer may be further included between each layer.

In one embodiment, the silica airgel may form a layer in the form of a monolith.

In one embodiment, the polyurethane foam may have a density of 10 to 100 kg/m ³ .

The sound-absorbing insulation material for automobile engine encapsulation of the present invention is formed of multiple layers and is not large in volume, so adhesion is improved and it can be applied to engines that generate high temperatures. It is applied closely to the engine to reduce heat energy and noise emitted to the outside of the engine. It is reduced more efficiently, resulting in improved insulation and sound absorption effects, and fuel efficiency can be improved due to these improved insulation characteristics.

1 is a reference diagram for explaining the engine encapsulation concept of the present invention.
Figure 2 is a diagram illustrating a sound-absorbing insulation material for automobile engine encapsulation according to an embodiment of the present invention.

Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. In general, the nomenclature used herein is well known and commonly used in the art.

Throughout this specification, when a part “includes” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary.

In one aspect, the present invention includes a polymer resin layer made of a polymer resin; A polyurethane foam layer laminated on top of the polymer resin layer; A silica airgel layer laminated on top of the polyurethane foam layer; and an aluminum sheet layer laminated on top of the silica airgel layer. It provides a sound-absorbing insulation material for automobile engine encapsulation, characterized in that it is made of multiple layers, including.

Figure 2 is a diagram illustrating an embodiment of a sound-absorbing insulation material for automobile engine encapsulation according to the present invention, and the present invention will be described in detail with reference to this.

In the present invention, the polymer resin layer 10 may be a polymer resin that can be generally used as a sound-absorbing insulation material for automobile interiors, but is preferably made of polyester nonwoven fabric with an area density of 50 to 300 g/m ² . . If the areal density is less than 50 g/m ² , the product rigidity may be reduced below a certain range and there is a risk of losing the product protection effect, and if it is more than 300 g/m ² , the weight of the composite will increase, making it lighter to improve fuel efficiency. This is because the effectiveness decreases.

In the present invention, the polyurethane foam layer 30 is laminated on the polymer resin layer, has a density of 10 to 100 kg/m ³ , and pores include 10 to 90% of open cells.

If the density of the polyurethane foam is less than 10 kg/m ³ , the density is excessively low and the polyurethane foam layer needs to be thick in order to have sound absorption by the polyurethane foam. In this case, the adhesion of the sound-absorbing insulator may decrease, If the density of polyurethane foam exceeds 100 kg/m ³ , the density is high and the thickness of the polyurethane foam layer may become thin, but there is a risk that sound absorption may be reduced. Accordingly, the polyurethane foam layer has a density of 10 to 100 kg/m ³ .

In addition, the pores of the polyurethane foam layer include open cells and closed cells to have elasticity, sound absorption, durability, and insulation. In particular, open cells, which refer to all cells with at least part of the cell open, It is included in a ratio of 10 to 90% to improve insulation, elasticity and sound absorption. Specifically, if the open cell of polyurethane foam is less than 10%, the surface area is reduced, which reduces the thermal and soundproofing effects. If it exceeds 90%, the foam has a high recovery rate, making it impossible to mold it into the intended shape after the press molding process. , containing 10 to 90% open cells.

Additionally, the polyurethane foam layer is laminated in an amount of 50 to 200 parts by weight compared to 100 parts by weight of the silica airgel layer laminated on top of the polyurethane foam layer. This is to strengthen the low mechanical properties of the silica airgel layer and efficiently improve the insulation and sound absorption rate while complementing the low insulation characteristics of the polyurethane foam. Specifically, the polyurethane foam layer is less than 50 parts by weight compared to 100 parts by weight of the silica airgel layer. This is because the sound absorption performance decreases, and if it is more than 200 parts by weight, the insulation effect due to the silica airgel is reduced due to the weight limit of the multilayer sound-absorbing insulation material, which is limited in accordance with the purpose of reducing the weight of the material considering the fuel efficiency of the vehicle.

In the present invention, the silica airgel layer 50 is a layer laminated on the polyurethane foam layer, and the silica airgel has a high porosity and a mesoporous pore structure of about 50 nm, thereby facilitating Knudsen diffusion. ) shows the effect. The Knudsen diffusion effect refers to the gas diffusion that occurs when gas passes through a pore and the probability of gas molecules colliding with the walls of the pore is greater than the probability of the gas molecules colliding with each other. Silica airgel has the Knudsen diffusion effect. This results in excellent insulation effect and sound absorption rate.

Moreover, in the present invention, the silica airgel is layered in the form of a monolith, so dust is not generated when the silica airgel is laminated, improving the process and working environment, and using a mold to perform the sol-gel method. It can be manufactured as a single piece.

In one embodiment, the silica airgel monolith is a mixture of 6 to 30 moles of solvent, 5 to 20 moles of water, 0.001 to 1 mole of acid catalyst, and 0.01 to 5 mole of base catalyst based on 1 mole of silica precursor on a molar ratio basis. After stirring at room temperature for 1 hour to 24 hours, the prepared sol is poured into a mold, dried for 10 hours to 3 days, aged in an oven at 30 to 50 degrees Celsius, and the solvent is dried to form a sol-gel. ) A monolithic silica airgel can be produced through reaction, wherein the solvent is one or more selected from methanol, ethanol, isopropyl alcohol, and butanol, and the solvent is contained in an amount of 6 to 30 moles based on 1 mole of the silica precursor. do. If the solvent content is less than 6 moles, the volume of the silica airgel is reduced, resulting in low insulation properties, and if it exceeds 30 moles, cracks are generated during the drying process due to an increase in the volume of the gel, resulting in a monolithic product. This is because manufacturing is impossible.

The water includes 5 to 20 moles of water based on 1 mole of the silica precursor. If the water content is less than 5 mol, mechanical performance deteriorates due to a low reaction rate, and if the water content exceeds 20 mol, cracks are generated during the drying process due to an increase in the volume of the gel.

The acid catalyst is one or more selected from sulfuric acid, hydrochloric acid, acetic acid, and oxalic acid, and is included in an amount of 0.001 to 1 mole based on 1 mole of the silica precursor. If the content of the acid catalyst is less than 0.001 mole, the particle formation rate of the silica precursor slows down, and if it is more than 1 mole, the particle size increases and precipitation occurs.

The base catalyst uses aqueous ammonia and contains 0.01 to 5 moles based on 1 mole of silica precursor. If the content of the base catalyst is less than 0.01 mol, the condensation reaction rate is reduced and gel formation is delayed, and if the content of the base catalyst is more than 5 mol, a non-uniform gel is formed.

In addition, at this time, the silica precursor may be any one or more selected from the group consisting of MTMS (Methyltrimethoxysilane), MTES (Methyltriethoxysilane), PTMS (Phenyltrimethoxysilane), PTES (Phenyltriethoxysilane), DMDMS (Dimethyldimethoxysilane), and DMDES (Dimethyldiethoxysilane). It is not limited.

In the present invention, the aluminum sheet layer 70 is applied as the skin layer of a sound-absorbing insulating material, and blocks the movement of radiant heat and provides flexibility to enable close contact with areas with complex surface shapes. To achieve this effect, the aluminum sheet layer has a thickness of 50 to 250 ㎛. Specifically, if the thickness of the aluminum sheet layer is less than 50 ㎛, the radiant heat blocking effect is insignificant, and if it is more than 250 ㎛, there is difficulty in forming and adhering the composite, so the aluminum sheet layer has a thickness of 50 to 250 ㎛. It can be needle punched.

In the present invention, the sound-absorbing insulation material may further include a binder layer (20, 40, 60) between each layer.

The binder layer is included between each layer to bond one layer to another layer. In general, any binder that can be used as a sound-absorbing insulating material for automobile interiors can be used, so the type is not limited, but preferably an inorganic binder, More preferably, an inorganic binder using liquid sodium silicate is used, and the binder layer is formed with a thickness of 0.1 to 2 mm between each layer to provide adhesion while preventing an increase in the weight of the material due to unnecessary thickness.

The sound-absorbing insulation material for automobile engine encapsulation of the present invention can be closely applied to the encapsulation engine, thereby more efficiently reducing heat energy and noise emitted to the outside of the engine, resulting in improved insulation and sound absorption effects. The sound-absorbing insulation material is each It can be manufactured by hot forming, cold forming, and trimming in multi-layers using layered members.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited by the examples.

Example

1. Manufacture of sound-absorbing insulation material

Example 1

(1) Production of monolithic silica airgel

A mixture was prepared by mixing 10 moles of methanol, 10 moles of water, 0.003 moles of sulfuric acid, and 0.05 moles of aqueous ammonia based on 1 mole ratio of the silica precursor Tetraethoxysilane (TMOS). Next, the mixture was stirred at room temperature for 20 hours to prepare a sol, then the sol was poured into a mold and aged at 25°C for 1 day at atmospheric pressure, and the solvent was dried to form a sol-gel (sol-gel). Silica airgel in the form of a monolith with mesopores was prepared through a gel reaction.

(2) Manufacture of sound-absorbing insulation materials

As shown in Figure 2, a sound-absorbing insulation material was manufactured. First, the polymer resin layer 10 is manufactured, then a binder layer 20 is formed on the upper surface of the polymer resin layer 10, and a polyurethane foam layer 30 is formed on the upper surface of the binder layer 20. A binder layer 40 is formed on the upper surface of the polyurethane foam layer 30, and the prepared silica airgel is laminated on the upper surface of the binder layer 40 to form a silica airgel layer 50, and the silica airgel layer ( 50) A binder layer 60 was formed on the upper surface, and an aluminum sheet layer 70 was formed on the upper surface of the binder layer 60 to manufacture a multi-layered sound-absorbing insulation material with a multi-layered structure.

Comparative Example 1

A multilayer sound-absorbing insulation material was manufactured in the same manner as Example 1, except that it did not include a silica airgel layer.

2. Comparison of physical properties

In order to compare and confirm the thermal conductivity and sound absorption coefficient of the multilayer sound-absorbing insulation material according to the present invention, the thermal conductivity (insulating performance) and sound absorption coefficient of the multilayer sound-absorbing insulation material prepared through Example 1 and Comparative Example 1 were measured using ASTM C518 hot plate method and MS 200- It was measured using the 39 analysis method and shown in Table 1 below. The sound absorption performance in Table 1 specifies the average sound absorption coefficient values in the frequency bands 1, 2, 3.15, and 5 kHz.

In addition, in order to confirm the effect of reducing fuel consumption due to such improvement in insulation characteristics, CO ₂ emissions were measured using FTP-75 (HWFET) after installing the sound-absorbing insulation material of the present invention on an actual vehicle engine, and the results are shown in Table 1.

division Thermal conductivity (mW/mK) average sound absorption rate
(1, 2, 3,15, 5 kHz) _CO2 emissions
(g/km) Example 1 35.8 0.69 182.93 Comparative Example 1 40.1 0.53 187.96

Through Table 1, the thermal conductivity of Example 1 is 35.8 mW/mK, which is a decrease of 4.3 mW/mK compared to 40.1 mW/mK of Comparative Example 1. The sound-absorbing insulation material of Example 1 is obtained by separating polyurethane foam and monolithic silica airgel. It can be seen that by including each layer, the monolith can exhibit improved insulation properties due to the silica airgel.

In addition, it can be seen that the average sound absorption coefficient of Example 1 is 0.69, which is about 30% improved compared to 0.53 of Comparative Example 1.

In addition, it was confirmed that the CO ₂ emissions of Example 1 were 182.93 g/km, which was reduced by about 2.7% compared to 187.96 g/km of Comparative Example 1.

Accordingly, by applying the sound-absorbing insulation material for engine encapsulation of the present invention to the engine, it is possible to provide improved insulation characteristics for heat consumed by the engine and high sound absorption performance for noise generated, and further reduced CO2 emissions. ₂ Fuel efficiency can be improved due to improved insulation characteristics through emissions.

10: Polymer resin layer
20: Binder layer
30: Polyurethane foam layer
40: Binder layer
50: Silica airgel layer
60: Binder layer
70: Aluminum sheet layer

Claims (4)

A polymer resin layer made of a polyester nonwoven fabric and a polymer resin having an area density of 50 to 300 g/m ² ;
A polyurethane foam layer laminated on top of the polymer resin layer and having a density of 10 to 100 kg/m ³ and pores having 10 to 90% open cells;
A silica airgel layer laminated on top of the polyurethane foam layer; and
It is composed of multiple layers, including an aluminum sheet layer laminated on top of the silica airgel layer,
The polyurethane foam layer is included in an amount of 50 to 200 parts by weight based on 100 parts by weight of the silica airgel layer,
The silica airgel is a monolith ( It forms layers in the form of a monolith and has a mesoporous structure,
The silica precursor is an automobile engine encapsule, characterized in that at least one selected from the group consisting of MTMS (Methyltrimethoxysilane), MTES (Methyltriethoxysilane), PTMS (Phenyltrimethoxysilane), PTES (Phenyltriethoxysilane), DMDMS (Dimethyldimethoxysilane), and DMDES (Dimethyldiethoxysilane) Sound-absorbing insulation for insulation.
According to claim 1,
A sound-absorbing insulation material for automobile engine encapsulation, characterized in that a binder layer is further included between each layer.
delete delete