JPH0511029B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multilayer molded soundproofing material, and more specifically, it is used for wall materials, ceiling materials, partitions, etc. that have sound absorption properties on the sound source side and exhibit overall soundproofing properties. The present invention relates to a multilayer molded soundproofing material useful in the field.

Although gypsum boards, asbestos slate boards, and the like have been used as soundproof boards in buildings, factories, and the like, it is difficult to obtain effective soundproofing effects using only these board materials. In addition, concrete structures with a predetermined air layer are known as sound insulation structures, and although such structures have a certain degree of sound insulation effect, construction of the structure is complicated and the construction period and costs are still low. It's not satisfying.

While significant noise is regarded as pollution, there are examples where even noise that was not a problem in the past has developed into a social problem as social life improves, so soundproofing and noise countermeasures are important in general buildings, factories, etc. It's becoming a problem.

In order to solve this problem, the present applicant previously proposed a noise treatment method (Japanese Patent Publication No. 54-19094) in which a molded body having a rear air layer with a limited air flow resistance value and height at the top of the overhang was proposed. A sound absorbing body made by joining two pieces of a molded body having a back air layer with a limited air flow resistance value at the top (Special Publication Publication No. 1983-2008) and a molded body with a back air layer with a limited air flow resistance value at the top of the overhanging part He contributed to soundproofing and noise countermeasures by proposing soundproofing plates (Special Publication No. 1989-8975) that were attached to metal plates, etc. However, in the case of soundproofing materials for vehicles, for example, it has become necessary to reduce the weight of vehicles in order to save energy, and weight reduction has been required. In view of the current situation, the present inventors were able to reduce the weight of the molded article by reducing the basis weight of the bulky nonwoven fabric without reducing the soundproofing effect at all, and further, to make the base material bulkier without increasing the weight of the molded article. As a result of intensive research into soundproofing materials that can achieve even better soundproofing effects, we have discovered that this can be achieved by using a material with a specific air flow resistance value as the skin layer, leading to the present invention. In other words, the gist of the present invention is at least a skin layer 1, a bulky nonwoven fabric layer 2 containing a thermosetting synthetic resin as a binder, and in which the thermosetting synthetic resin is scattered in an uncured state. The air flow resistance value at the top of the overhanging part of the molded sound insulation material is 20 to 20 at the skin layer.
100c.gsrayls, bulky nonwoven fabric layer: 5~
200c.gsrayls and molded soundproofing material as a whole, 30
Multilayer molded soundproofing material with overhang top air flow resistance value of ~300c.gsrayls.

The bulky nonwoven fabric used in the present invention is subjected to heat molding, and since it requires shape retention after heat molding, it contains a thermosetting synthetic resin as a binder, and the thermosetting synthetic resin has a bulky property. It is essential that they are scattered in the non-woven fabric in an uncured state. If this requirement is met, the main discontinuous fiber material may be one or a combination of two or more selected from animal, vegetable, mineral, synthetic resin, etc., and as a binder. There is no problem in using a thermoplastic synthetic resin in combination.

Generally, the thickness is 8 to 50m/m, the areal density is 400 to
Preferably, it is a bulky nonwoven fabric of 4000 g/m ² .

Non-flammable and flame retardant treatment is applied to bulky non-woven fabrics as necessary.
Waterproofing treatment, water repellent treatment, fuzz prevention treatment, etc. can be optionally applied. Moreover, there is no problem even if these treatments are performed after heat molding. For example, sodium silicate aqueous solution, silicone-based, fluorine-based water repellents, organic phosphorus compounds, organic sulfur halogen compounds,
Examples include spraying flame retardants such as inorganic antimony amide compounds and sodium fluorosilicate.

However, even when such a treatment is applied, the treated bulky nonwoven fabric molded article must have an air flow resistance value of 5 to 200 c.gsrayls at the top of the overhanging portion. Within this range, by adjusting the air flow resistance value of the skin layer at the top of the overhang after molding, a desired air flow resistance value can be achieved as a molded soundproofing material, and the moldability and strength are also satisfied.

Although the skin layer needs to be decorative, the material must be selected with due consideration to the sound absorption effect.
In other words, the air flow resistance value of the skin layer at the top of the overhang after molding must be between 20 and 100c.gsrayls, and if it is not within this range, it will not be possible to achieve satisfactory soundproofing and weight reduction at the same time as a molded soundproofing material. Therefore, when using a non-breathable material, such as a relatively thick vinyl chloride resin sheet (commonly referred to as vinyl chloride leather), it is necessary to provide openings.

Preferably, it is a thin nonwoven fabric or cloth, and when using a resin film, the thickness is preferably about 0.01 m/m when no openings are provided.

The air flow resistance value at the top of the overhanging part of the molded soundproofing material consisting of the skin layer and the bulky nonwoven fabric layer is 30~
300 c. If the angle is acute, substantially the entire area of the overhang should have such an air flow resistance value.

Air flow resistance value at the top of the overhang is 30c.gs
rayls, it is difficult to obtain a satisfactory sound absorption effect, and the shape retention and rigidity are insufficient, making it difficult to use as a practical soundproofing material. Moreover, if it exceeds 300c.gsrayls, it is inconvenient because it may lose its properties as a porous sound absorbing material and become impractical as a sound insulating material.

For flat areas, the range of air flow resistance is not particularly limited, and there is no problem in exceeding 300c.gsrayls in terms of rigidity as a soundproofing material, shape retention, etc. If the shape retention, rigidity, etc. are within a practical range, the air flow resistance value of the flat part should also be 30.
~300c.gsrayls are preferred in terms of soundproofing.

The shape and arrangement of the overhanging portion of the molded body used in the present invention may be arbitrary, and the molded body used to carry out the present invention can be used in large quantities without considering the shape of the base wall to which the molded body is attached. In the case of production, etc., it is convenient to arrange protruding parts of a predetermined shape, such as a hemisphere or a truncated pyramid shape, regularly or irregularly. It is practically preferable to provide an overhanging portion in a specific pattern or picture shape, since it can also provide a decorative effect as an interior material without reducing the noise control effect.

In carrying out the present invention, the molded body may be attached with its flat portion in direct contact with the base wall, or it may be attached to the base wall via a support or the like.

As a method for attaching, an adhesive method, a screw fixing method, etc. can be arbitrarily selected.

The distance between the base wall surface and the top inner surface of the overhanging part of the molded body, that is, the thickness 3 of the air layer formed between the base wall and the molded body, varies depending on the frequency of the noise to be treated, but is 5. A range of ~200 m/m is preferred.
If it is less than 5m/m, it will be difficult to form a back air layer, so the sound absorption properties will be significantly reduced and there is a risk that the noise treatment effect will not be obtained.If it is more than 200m/m, the increase in the sound absorption effect will not be noticeable, and , the space occupancy becomes large, making it impractical.

According to the present invention, the method for integrating the multilayer molded soundproofing material is to place a skin on a bulky nonwoven fabric, and
Heat and pressure molding is performed at 250° C. and 2 to 20 kg/cm ² to form a bulky nonwoven fabric layer with a thickness of 2 to 15 m/m. that time,
It is also preferable to interpose a thermoplastic resin film between the bulky nonwoven fabric and the skin, and providing holes in the thermoplastic resin film prevents the sound absorption effect from deteriorating.

Examples are given below to provide a more detailed understanding of the present invention. Naturally, the present invention is not limited to the following examples.

Example 1 20 parts by weight of phenol resin powder was sprinkled and mixed with 55 parts by weight of fallen cotton and 25 parts by weight of recycled wool to form a fleece, heated to 180°C in a heating furnace, and made into a fleece with a thickness of 24 m/m.
A bulky nonwoven fabric with an areal density of 880 g/m ² was obtained.

A thin nonwoven fabric having a top air flow resistance of 80 c.gsrayls after molding and an areal density of 100 g/m ² was attached to this bulky nonwoven fabric to form a molding material.

Comparative Example 1 20 parts by weight of phenolic resin powder was sprinkled and mixed with 55 parts by weight of fallen cotton and 25 parts by weight of waste wool to form a fleece, heated to 180°C in a heating furnace, and made into a fleece with a thickness of 35 m/m.
A bulky nonwoven fabric with an areal density of 1320 g/m ² was obtained.

Saran cloth having substantially zero air flow resistance at the top after molding was adhered onto this bulky nonwoven fabric to form a molding material.

Example 2 20 parts by weight of phenol resin powder was sprinkled and mixed with 55 parts by weight of fallen cotton and 25 parts by weight of recycled wool to form a fleece, heated to 180°C in a heating furnace, and made into a fleece with a thickness of 24 m/m.
A bulky nonwoven fabric with an areal density of 880 g/m ² was obtained.

A thin nonwoven fabric having a top air flow resistance of 80 c.gsrayls after molding and an areal density of 100 g/m ² was attached to this bulky nonwoven fabric to form a molding material.

Comparative Example 2 20 parts by weight of phenolic resin powder was sprinkled and mixed with 55 parts by weight of fallen cotton and 25 parts by weight of waste wool to form a fleece, which was heated to 180°C in a heating furnace to produce the same bulky nonwoven fabric as in Example 1. Top air flow resistance on top is 10c.gs
Rayls' cloth was attached and used as a molding material.

Results The air flow resistance after molding of the molding materials of Example 1 and Comparative Example ¹ was 100 c. Each weight is
They were 1180g and 1580g, a reduction of 400g.

The air flow resistance after molding of the molding materials for Example 2 and Comparative Example 2 is 100c.gsrayls and 40c.gs, respectively.
rayls, the weight of each hood insulator, which is a 1.2 m ² molded product, was 1180 g. Below is a comparison of the soundproofing effects (sound absorption coefficient measured using the reverberation room method, unit: %).

Example 2 Comparative Example 250Hz 40 50 500Hz 70 55 1000Hz 100 80 2000Hz 100 95 4000Hz 100 100 As described above, the multilayer molded soundproofing material of the present invention exhibited weight reduction and improved soundproofing effect.

Claims (1)

[Claims] 1 A molded soundproofing material comprising at least a skin layer 1 and a bulky nonwoven fabric layer 2 containing a thermosetting synthetic resin as a binder and in which the thermosetting synthetic resin is scattered in an uncured state, The air flow resistance value at the top of the overhanging part of the molded soundproofing material is 20 at the skin layer.
~100c.gsrayls, 5 for bulky nonwoven fabric layer
~200c.gsrayls and molded soundproofing material as a whole,
A multilayer molded soundproofing material characterized by having an air flow resistance value at the top of the overhang of 30 to 300c.gsrayls.