JPH115499A - Sound insulating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound insulating material of a surface integrated polyurethane foam moldings, which has the excellent vibration characteristic in a low and a middle frequency areas and which has high productivity, by setting air permeability of a foam layer at a specified value or more, and setting hardness thereof at a specified value or less. SOLUTION: In a molding, air permeability of a foam layer is usually set at 3.0 ft<3> /minute or more, and desirably at 3.0-8.0 ft<3> /minute, and hardness of the foam layer is usually set at 8 kg/314 cm<2> or less (25% ILD), and desirably at 3-8 kg/314 cm<2> . In the case of the air permeability less than 3.0 ft<3> /minute or in the case where the foam hardness exceeds 8 kg/314 cm<2> , vibration characteristic is deteriorated, and the sound insulating effect in relation to the solid propagation sound is remarkably deteriorated. This surface integrated polyurethane foam molding has excellent sound insulating property in relation to the solid propagation sound in a low and a middle frequency areas. A method for molding surface integrated moldings has excellent productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded molded product of a skin-integrated polyurethane foam having excellent vibration characteristics (sound insulation performance) at low and medium frequencies and a method for producing the same.

[0002]

2. Description of the Related Art As a polyurethane foam molded product having a vibration characteristic (soundproofing performance), a polyurethane foam molded product containing a viscous substance such as asphalt or urethane oligomer has been known. (For example, JP-A-62-205115).

[0003]

However, the above-mentioned ones have the following disadvantages. When the raw material is injected into a mold due to its high viscosity, the flowability of the raw material in the mold is poor, and the formability of the foam is poor. Form removal time is long and productivity is poor. Since the air permeability of the foam is poor, the trapped air acts as a spring, and the vibration characteristics (sound-proof performance of solid-borne sound) in the low and medium frequency regions are reduced.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have found a polyurethane foam molded molded product having excellent skin characteristics in low and medium frequency regions (sound insulation performance) and high productivity, and a method for producing the same. As a result of the study, the present invention has been reached.

That is, the present invention relates to a molded polyurethane foam molded product having an integral skin, wherein the air permeability of the foam layer is 3.0 ft ³ / min or more and the hardness of the foam layer is 8 kg.
/ 314 cm ² or less (25% ILD); molded product characterized by being active hydrogen-containing compound component (a) and aromatic polyisocyanate (b) in a mold in which skin is set Is reacted in the presence of a blowing agent (c), a tertiary amine catalyst (d) and, if necessary, other additives (e) to produce a skin-integrated polyurethane foam molded article, The weight ratio between the high molecular weight polyol (a1) and the monool (a2) is 1).
Using a component consisting of 00: 0 to 50:50 and NCO
React with an index of 80 or less to form
And a soundproofing material for a vehicle dash silencer or a backing of a car floor carpet made of the molded product; and a vehicle dash incorporating the soundproofing material. Fig. 2 shows a silencer and a floor carpet of an automobile backed by the above soundproofing material.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The skin constituting the molded molded article of the present invention is not particularly limited, and a material for a skin which is usually used for an integral polyurethane foam molded molded article,
For example, a sheet formed by adding various fillers to a resin such as a vinyl chloride resin or an ethylene vinyl acetate resin as necessary can be used. The molded article of the present invention has a structure in which a skin and a foam layer are integrated by molding in a mold. Examples of the shape of the molded product of the present invention include a flat plate having one surface covered with a skin or a plate with irregularities.

In the molded molded article of the present invention,
The air permeability of the foam layer is usually 3.0 ft ³ / min or more, preferably 3.0 to 8.0 ft ³ / min, and the hardness of the foam layer is usually 8 kg / 314 cm ² or less (25% ILD). Preferably, it is 3 to 8 kg / 314 cm ² . 2. breathability.
0 ft ³ / min or foam hardness of 8 kg / min.
If it exceeds 314 cm ² , the vibration characteristics (reducing the spring constant) aimed at by the present invention are deteriorated, and the sound insulation effect of the sound propagating through the solid is significantly impaired. In the above, the measured value of the air permeability was measured using a Dow-type air flow meter,
It is a value measured under the condition of a square shape of 50 × 50 × 25 mm. The hardness of the foam layer was measured according to JIS K-63.
2 cm thick, 25% ILD (kg / 31
This is a value measured under the condition of 4 cm ² ). The dow air flow meter is a device for measuring the permeability of urethane foam, and is measured by the following procedure. Vertical 50 mm horizontal 50 mm depth 2 provided at the center of the front of the device
A test piece of the same size is loaded into a recess of 5 mm in which the back is partitioned by a lattice. A vacuum is drawn from behind the test piece, and the amount of air per unit time which passes through the inside from the exposed surface side of the test piece and is sucked behind is measured.

In the method of the present invention, the high molecular weight polyol (a1) constituting the active hydrogen-containing compound (a) is, for example, a low molecular weight compound having two or more active hydrogen atoms (polyhydric alcohols, amines) And the like, and a polymer polyol obtained by polymerizing an ethylenically unsaturated monomer (acrylonitrile, styrene, etc.) in the product (Japanese Patent Application Laid-Open No. Sho 54). -10899, JP-A-54-122
396). Examples of the polyhydric alcohols include dihydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol and neopentyl glycol;
And trivalent to octavalent polyhydric alcohols (glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose, etc.). Examples of the amines include ammonia; mono- -, di -, and triethanolamine, isopropanolamine, alkanolamines such as aminoethylethanolamine; alkylamines C ₁ -C _20; ethylenediamine, such as hexamethylene diamine C ₂ -C ₆ alkylene diamine; diethylenetriamine, polyalkylene polyamines such as triethylenetetramine; aniline, phenylenediamine, diaminotoluene, xylylenediamine, aromatic amines such as methylene dianiline, diphenyl ether diamine; isophoronediamine, cyclohexylenediamine And alicyclic amines such as aminoethylpiperazine and heterocyclic amines described in JP-B-55-21044. These low molecular compounds having two or more active hydrogen atoms may be used in combination of two or more. Of these, polyhydric alcohols are preferred.

The alkylene oxide to be added to the low molecular compound having two or more active hydrogens includes ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-, 1,3-, , 4-,
Examples thereof include 2,3-butylene oxide and the like, and a combination of two or more thereof, and a combination of EO and PO is preferable. When EO and PO are used together, the addition format is to add EO to the end after adding PO (EO chip type),
Alternatively, those in which PO and EO are added randomly (random type), or those in which EO is added to the terminal after block addition or random addition of EO inside the molecular chain (balance type), etc. A balance type of 10 to 20% by weight is preferred.

The average number of functional groups of the high molecular weight polyol (a1) is usually 2.0 to 8.0, preferably 2.0 to 4.0,
More preferably, it is 2.0 to 2.5, and the OH equivalent is usually 800 or more, preferably 1,000 to 2,000. If the average number of functional groups is less than 2 or the OH equivalent exceeds 2,000, the curing time will be long and the productivity will be poor. If the average number of functional groups is more than 8 or the OH equivalent is less than 800, the foam has poor air permeability and poor vibration characteristics.

In the method of the present invention, the monool (a)
Examples of 2) include monovalent alcohols having 1 to 30 carbon atoms and monovalent phenols described in JP-A-62-205115.
And alkylene oxide adducts of low molecular weight compounds having one active hydrogen atom such as phenols (eg, phenol and cresol). As the alkylene oxide to be added to the low molecular weight compound, EO, PO, 1,2-,
Examples include 1,3-, 1,4-, 2,3-butylene oxide and the like, and a combination of two or more thereof. The added mole number of the alkylene oxide is usually 2 to 40 moles, preferably 5 to 30 moles. Preferred monools (a2) are those obtained by adding PO to monovalent alcohol and then adding EO to the terminal. The amount of terminal EO is 10% by weight or less and the OH equivalent is 500 to 2000. It is not limited.

The weight ratio of the polymer polyol (a1) to the monool (a2) is from 100: 0 to 50:50,
Preferably it is 90:10 to 70:30. When the content of the mono-ol (a2) exceeds 50, a remarkable decrease in foam strength, poor adhesion to a skin material, and the like occur. Mono-ol (a
The use of 2) is preferable in terms of contributing to the increase in the air permeability that is the object of the present invention, but the desired air permeability can be ensured even with the high molecular weight polyol (a1) alone.

As the aromatic polyisocyanate (b) used in the method of the present invention, an aromatic polyisocyanate conventionally used for producing urethane foam can be used. For example,
TDI; MDI; Crude TDI; Crude MDI; Modified liquid M
DI (carbodiimide modified, trihydrocarbyl phosphate modified, etc.); prepolymers containing free isocyanate groups from these and the above-mentioned polyetherpolyols; and combinations of two or more of these. Can be Of these, preferred are TDI and TDI and crude M
The combination of DI and particularly preferred is TDI and crude MD.
I.

The foaming agent (c) includes water and / or other foaming agents (trichloromonofluoromethane, methylene chloride, etc.). (C)
The amount used for foaming a general urethane foam (for example, 1 to 20% by weight based on the active hydrogen-containing compound component (a)) may be used.

The tertiary amine catalyst (d) includes triethylamine, N, N'-dimethylaminodiethyl ether, tetramethylhexamethylenediamine, tetramethylethylenediamine, dimethylethanolamine, N-
Methyl-N ′-(2-dimethylamino) ethylpiperazine, 1,2-dimethylimidazole, triethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, N, N, N ′, N ", N" -pentamethyldipropylenetriamine, tetramethylguanidine and the like. These may be used in combination of two or more. Among them, preferred are tertiary amine catalysts (d) having a gelation reaction constant of 6.0 or less when TDI-100 and diethylene glycol are reacted in the presence of this catalyst.
1). Here, the gelation reaction constant is a reaction constant by a gelation reaction when equimolar amounts of TDI-100 and diethylene glycol are reacted in the presence of a catalyst in a benzene solution, It shows the reaction activity. Specific examples of (d1) include, among those exemplified above, triethylamine, N, N′-dimethylaminodiethylether, tetramethylhexamethylenediamine, tetramethylethylenediamine, dimethylethanolamine, N-methyl-N '-(2-dimethylamino) ethylpiperazine, 1,2-dimethylimidazo-
Le. More preferred of these are N,
N'-dimethylaminodiethyl ether and tetramethylethylenediamine. If necessary, other catalysts may be used together with (d). As these catalysts, for example, known catalysts described in JP-A-1-203420 can be used. Specific examples include metal salts of carboxylic acids, alkoxides and phenoxides of alkali and alkaline earth metals, quaternary ammonium salts, imidazoles, and organometallic compounds such as tin and antimony.
When (d1) is used in combination with a tertiary amine catalyst other than (d1) or the above-mentioned other catalysts, it can be used as a preferable catalyst.

Other additives (e) used as required include surfactants (such as silicone surfactants), pigments,
Fillers, asphalts, flame retardants, solvents, thixotropic agents, and the like.

The NCO index for producing a polyurethane foam by the method of the present invention is usually 80 or less, preferably 80 to 40. When the NCO index exceeds 80, the foam hardness increases and the resonance frequency shifts to a higher frequency side. As a result, the spring constant increases, and the sound insulation effect of the solid-borne sound is reduced.

In the method of the present invention, the method of mold forming may be the same as the conventional one, and any one-shot method or prepolymer method (semi-prepolymer method) can be applied, but the one-shot method is preferred. Molding conditions are usually as follows:
5-45 ° C, mold temperature and skin temperature 25-80 ° C
Then, using a high-pressure or low-pressure foaming machine, two raw materials (isocyanate component and other components) are mixed and injected into a mold, and demolded in a cure time of 1 to 10 minutes.

[0019]

The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. Hereinafter, "part" indicates "part by weight". The abbreviations in the examples have the following meanings.

Polyol A: PO and E added to glycerin
Primary OH content 80%, molecular weight 50 obtained by sequential addition of O
00 polyether polyol. Polyol B: PO, EO, P in propylene glycol
A polyetherpolyol having a primary OH content of 75% and a molecular weight of 4000 obtained by sequentially adding O and EO. Polyol C: Polyetherpolyol having a primary OH content of 75% and a molecular weight of 7000 obtained by sequentially adding PO and EO to glycerin. Polyol D: Two acrylonitriles in Polyol A
A polymer polyol obtained by polymerizing 0%. Monool A: Monool having a molecular weight of 1200 obtained by adding PO to butanol.

TDI-80: toluene diisocyanate (weight ratio of 2,4 / 2,6 isomers = 80/20) Crude MDI: crude diphenylmethane diisocyanate TM80: TDI-80 / crude MDI = 80 / 20
Blend products

U1000: Tetramethylhexamethylenediamine manufactured by San Apro Co., Ltd., gelation reaction constant
08 33LV: DABCO 33LV (dipropylene glycol solution of triethylenediamine manufactured by Sankyo Air Products), gelation reaction constant of triethylenediamine 1
2.2 TMED: tetramethylethylenediamine, gelation reaction constant 4.86

L5309: Silicone foam stabilizer manufactured by Nippon Unicar Co., Ltd. SRX274C: Silicone foam stabilizer manufactured by Toray Dow Corning Silicone Co., Ltd.

Examples 1-4, Comparative Example 1 According to the foaming formulation (parts) shown in Table 1 below, (a1)
After premixing each of the components (a2) and (c) to (e), the component (b) was added, and the mixture was vigorously stirred for 8 seconds, followed by 3k
g / m ² of vinyl chloride resin mat set in the lower mold 5
Aluminum mold of 0-60 ° C (85X85X2cm)
And foamed. After curing at 60 ° C. for a predetermined time, demolding was performed to obtain a molded product of Examples 1 to 4 and Comparative Example 1.

[0025]

[Table 1]

Next, the results of a foam physical property test of the foam molded products of Examples 1 to 4 and Comparative Example 1 are shown in Table 2 and FIG.

[0027]

[Table 2]

Note 1) Form physical property test methods and units in Table 2 and FIG. 1 are as follows. Total density (kg / m ³ ): Foam weight / apparent volume of foam Tensile strength (kg / cm ² ): JIS K-6301 Elongation (%): JIS K-6301 Tear strength (kg / cm): JIS K-6382 25% ILD (kg / 314cm ² ): JIS K-6382 Compression set (%): JIS K-6382 Breathability (ft ³ / min): Dow type air flow meter Measurement. (The test piece is 50 × 50 × 2 mm.) Resonance frequency: The frequency at the position where the vibration transmissibility becomes maximum in the following vibration characteristic test. Vibration characteristics: Vibration frequency 0-500Hz Vibration level 0.1-0.2G, 0.2-0.3mm Form and vinyl chloride resin mat on aluminum plate of vibration source Calculate the acceleration displacement between vinyl resin mats. Note 2) In FIGS. 1A and 1B, Examples 1 and 4 are selected as representative examples of the examples, and the vibration characteristics are shown together with Comparative Example 1. FIG.
Indicates that the lower the resonance frequency and the lower the transmissibility of vibration, the better the sound insulation performance.

[0029]

Industrial Applicability The molded polyurethane foam molded product of the present invention is excellent in vibration characteristics (soundproofing performance), particularly, sound insulation of solid-borne sound in low and medium frequency regions. Further, the method of the present invention is excellent in productivity and economical because it is an integral skin mold molding method. Because of the above-mentioned effects, the form mold molded article of the present invention obtained by the method of the present invention is useful as a sound insulation (sound insulation) material used for dash silencers of automobiles, backing of floor carpets, and the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing the vibration characteristics of the foams obtained in Examples 1, 4 and Comparative Example.

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[Procedure amendment]

[Submission date] May 25, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

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[Correction method] Change

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[0003]

However, the above-mentioned ones have the following disadvantages. Since the air permeability of the foam is poor (less than 1.0 ft ³ / min), the trapped air acts as a spring, and the vibration characteristics (sound-proof performance of solid-borne sound) in the low and medium frequency regions are reduced. During molding, if the raw material has high viscosity and is injected into the mold,
Poor flowability of raw materials in the mold and poor formability of foam. The demolding time of the foam becomes longer and the productivity is poor. Further, in the case of a conventionally known general skin-integrated polyurethane foam molded product, the foam layer generally has a high hardness, and when the NCO index is lowered and the foam layer is softened, the air permeability decreases, and in all cases, the sound insulation performance is reduced. There was a problem that was insufficient. In the conventional method, air permeability (3.0 ft ³ / min or more) sufficient to exhibit sufficient soundproof performance against solid-borne sound and the hardness of the foam layer (25%
However, it was difficult to obtain a molded article of a polyurethane foam molded integral with the skin, which simultaneously satisfies an ILD of 8 kg / 314 cm ² or less.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction contents]

Note 1) The foam physical property test methods and units in Table 2 and FIG. 1 are as follows. Total density (kg / m ³ ): Foam weight / apparent volume of foam Tensile strength (kg / cm ² ): JIS K-6301 Elongation (%): JIS K-6301 Tear strength (kg / cm): JIS K-6382 25% ILD (kg / 314 cm ² ): JIS K-6382 Compression set (%): JIS K-6382 Air permeability (ft ³ / min): Measured with a Dow airflow meter. (The test specimen is 50 × 50 × 25 mm.) Resonance frequency: The frequency at the position where the vibration transmissibility is maximized in the following vibration characteristic test. Vibration characteristics: Vibration frequency 0-500Hz Vibration level 0.1-0.2G, 0.2-0.3mm Foam, vinyl chloride resin mat placed on aluminum plate of vibration source in order of aluminum plate and vinyl chloride resin The acceleration displacement between mats is obtained. Note 2) In FIGS. 1A and 1B, Examples 1 and 4 are selected as representative examples of the examples, and the vibration characteristics are shown together with Comparative Example 1. FIG.
Indicates that the lower the resonance frequency and the lower the transmissibility of vibration, the better the sound insulation performance. ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 25, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

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[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

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[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproofing material comprising a molded product of a skin-integrated polyurethane foam having excellent vibration characteristics (soundproofing performance) at low and medium frequencies.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

[0004]

Means for Solving the Problems The present inventors have studied to find a soundproofing material made of a skin-integrated polyurethane foam molded article having excellent vibration characteristics (soundproofing performance) in low and medium frequency regions and high productivity. As a result, the present invention has been achieved.

[Procedure amendment 4]

[Document name to be amended] Statement

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[Correction method] Change

[Correction contents]

That is, according to the present invention, the air permeability of the foam layer is not less than 3.0 ft ³ / min, and the hardness of the foam layer is 8 k.
g / 314 cm ² or less (25% ILD), a sound insulating material for an automobile dash silencer or a backing of a floor carpet of an automobile, which is made of a polyurethane foam molded article having an integral skin; Car dash silencer,
And a car floor carpet lined with the soundproofing material.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

In the method of the present invention (the method for producing the soundproofing material of the present invention, the same applies hereinafter), as the polymer polyol (a1) constituting the active hydrogen-containing compound (a), for example, two or more active hydrogen atoms are used. A polyether polyol having a structure in which an alkylene oxide is added to a low-molecular compound (polyhydric alcohols, amines, etc.) or a polymer obtained by polymerizing an ethylenically unsaturated monomer (acrylonitrile, styrene, etc.) in these compounds. And polymer polyols (described in JP-A-54-10899 and JP-A-54-122396). Examples of the polyhydric alcohols include ethylene glycol, propylene glycol,
1,4-butanediol, 1,6-hexanediol,
Dihydric alcohols such as diethylene glycol and neopentyl glycol; 3 alcohols described in JP-A-62-205115
And -8-valent polyhydric alcohols (such as glycerin, trimethylolpropane, pentaerythritol, sorbitol, and souce). Examples of the amines include ammonia; mono-, di-, and triethanolamine, isopropanolamine, alkanolamines such as aminoethylethanolamine; C ₁ ~
Alkyl amines C _20; ethylenediamine, C ₂ -C ₆ alkylene diamines, such as hexamethylenediamine; diethylenetriamine, polyalkylene polyamines such as triethylenetetramine; aniline, phenylenediamine, diaminotoluene, xylylenediamine, methylenedianiline, diphenyl ether Aromatic amines such as diamine; alicyclic amines such as isophoronediamine and cyclohexylenediamine; aminoethylpiperazine; and heterocyclic amines described in JP-B-55-21044. These low molecular compounds having two or more active hydrogen atoms may be used in combination of two or more. Of these, polyhydric alcohols are preferred.

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Claims (5)

[Claims] 1. The air permeability of the foam layer is 3.0 ft ³ / min or more, and the hardness of the foam layer is 8 kg / 314 cm ^2.
A sound insulating material for an automobile dash silencer or a backing of an automobile floor carpet, comprising a skin-integrated polyurethane foam molded article characterized by the following (25% ILD). 2. An active hydrogen-containing compound component (a) and an aromatic polyisocyanate (b) are mixed with a foaming agent (c), a tertiary amine catalyst (d) and, if necessary, in a mold in which a skin is set. (E) reacting in the presence of the additive (e) to produce a molded polyurethane foam molded product with an integral skin, wherein (a) is a polymer polyol (a1) and a monool (a2). The soundproofing material according to claim 1, wherein the soundproofing material is a molded product obtained by using a component having a weight ratio of 100: 0 to 50:50 and reacting at an NCO index of 80 or less. 3. A tertiary amine catalyst (d1) having a gelation reaction constant of 6.0 or less when TDI-100 and diethylene glycol are reacted in the presence of the catalyst as (d). The soundproofing material according to claim 2, which is used. 4. A vehicle dash silencer incorporating the soundproofing material according to claim 1. 5. A floor carpet for an automobile, which is lined with the soundproofing material according to claim 1.