KR100205637B1 - Manufacturing method of asphalt blended polyurethane foam - Google Patents

Abstract

The present invention relates to an asphalt-dispersed polyurethane foam and a method of manufacturing the same, and more particularly, to a dispersion liquid in which asphalt is uniformly dispersed even at room temperature by emulsifying and dispersing asphalt in a polyol having a specific molecular weight and containing an additive of a specific component thereto. The present invention relates to a polyurethane foam and a method for producing the same, which are used as a soundproofing and sealing material as well as a vibration damping and shock absorbing material because the asphalt is uniformly dispersed in the polyurethane foam by preparing and foaming it together with an isocyanate component.

Description

Asphalt-dispersed polyurethane foam and its manufacturing method

The present invention relates to an asphalt-dispersed polyurethane foam and a method of manufacturing the same, and more particularly, to a dispersion liquid in which asphalt is uniformly dispersed even at room temperature by emulsifying and dispersing asphalt in a polyol having a specific molecular weight and containing an additive of a specific component thereto. The present invention relates to a polyurethane foam and a method for producing the same, which are used as a soundproofing and sealing material as well as a vibration damping and shock absorbing material because the asphalt is uniformly dispersed in the polyurethane foam by preparing and foaming it together with an isocyanate component.

In the automotive and construction fields, materials having excellent energy absorption effects such as impact and sound insulation are required. Although the felt made by the resin treatment of the recycled surface and the synthetic fiber as an energy absorbing material, the felt has a disadvantage of high manufacturing cost. In addition, polyurethane foams, which have advantages of excellent energy absorption, molding to complex parts, low specific gravity and low processing cost, have been used as energy absorbing materials such as shock absorption and sound insulation.

Particularly, in the case of automobiles, it has been used simply as a means of transportation in the past, but in recent years, it is used not only as a means of transportation but also as a living space. Doing.

The ride comfort of the vehicle is determined by the noise and vibration damping characteristics in the low and medium frequency ranges, but the polyurethane foams, especially the flexible polyurethane foams, exhibit excellent sound absorption characteristics in the high frequency region but low sound absorption characteristics in the low frequency region. Therefore, studies have been conducted to improve sound absorption and vibration damping characteristics, heat resistance, and cold resistance in the low frequency region for materials applied to the automotive field.

As a result of this study, asphalt blended polyurethane foam, which is a mixture of polyurethane and viscous asphalt, was used, which has been found to be effective in removing vibrations, ie, structural propagation noises generated from automobile engines and road surfaces. Accordingly, asphalt blended polyurethane foam has been applied to various applications such as sealing materials, sound absorbing materials, vibration damping materials, and the like in the automobile and construction fields.

Representative conventional manufacturing methods for asphalt blended polyurethane foams include impregnation and foaming.

The impregnation method is a method of impregnating a soft polyurethane foam having a continuous bubble with an asphalt aqueous emulsion or an asphalt solution dissolved in a solvent. This impregnation method is expensive to manufacture because it requires additional equipment for impregnating the asphalt solution to the polyurethane foam secondaryly, and the asphalt attached to the bubble wall of the foam by impregnation is relatively easy to fall off and is also impregnated. Asphalt is lost by the compression process, there is a problem such as deterioration in quality.

The foaming method is a method of preparing a polyurethane prepolymer by polymerizing a polyol component and an isocyanate component, and then foaming it with an aqueous asphalt emulsion [Japanese Patent Laid-Open No. 59-15433], and integrally foaming a polyol component, an isocyanate component, asphalt, and the like. Japanese Patent Application Laid-Open No. 54-77696. In the former foaming process, the latter process is more industrially mass-produced than the former method because the manufacturing process is complicated and the manufacturing cost is high, such as additional processing process that requires separate preparation of asphalt aqueous emulsion and additional manufacturing process of prepolymer. Is beneficial. In Japanese Laid-Open Patent Publication No. 54-77696, which adopts the latter method, an expensive polybutadiene polyol (Poly BD R-45HT; manufactured by Arco Chemical Co., Ltd.) is used as a polyol component in order to increase compatibility with asphalt when mixing and foaming. There is a problem that the manufacturing cost is high.

In European Patent No. 0,272,856, asphalt is dispersed in a polyol using an emulsifier, and then an isocyanate, a blowing agent, a catalyst, and a foaming agent are mixed with the mixture to prepare a polyurethane foam in which asphalt is dispersed. However, this method is cumbersome to add the additives used in the foam production separately and has a lot of difficulties in using a foaming machine.

Therefore, the conventional production method of the polyurethane foam dispersed in asphalt is required to improve the method to simplify the manufacturing process to reduce the manufacturing cost, and to further improve the asphalt dispersibility in the foam.

The inventors of the present invention endeavored to solve the problems of the manufacturing process, high manufacturing cost, etc. in the conventional single-foaming method, as a result of emulsifying and dispersing polyol, asphalt and other additives at a specific component and composition ratio even at room temperature The present invention has been completed by preparing a dispersion in which asphalt is uniformly dispersed, to facilitate handling of the dispersion, and by reducing a manufacturing cost by using a general-purpose polyol.

Accordingly, an object of the present invention is to provide a polyurethane foam in which asphalt is evenly dispersed in a foam and a simple manufacturing method for manufacturing the same.

1 is a graph showing a comparison of the sound absorption rate for the polyurethane foam prepared in Example 8 of the present invention and a conventional sound absorbing material.

In the method for producing a polyurethane foam containing asphalt, a process of preparing a dispersion by emulsifying and dispersing 40 to 150 parts by weight of asphalt (infiltration degree 30 to 120) to 100 parts by weight of a polyol component having a molecular weight of 2000 to 6000, in the dispersion 1.0 to 30 parts by weight of foaming agent, 0.5 to 3.0 parts by weight of amine catalyst to form a foaming system, and asphalt dispersed poly, including the process of foaming by adding 20 to 40 parts by weight of isocyanate component to 100 parts by weight of the foaming system. It is characterized by a method for producing a urethane foam.

Referring to the present invention in more detail as follows.

The present invention is prepared by emulsifying and dispersing asphalt in a polyol component having a specific molecular weight and dispersing a catalyst, a foaming agent, a foaming agent, etc. in the isocyanate component, and foaming it integrally so as to uniformly disperse the asphalt into fine particles. The manufacturing cost reduction effect by the simplification of the process, ease of handling the emulsion dispersion even at room temperature, and the problem that the asphalt has been a problem in the conventional impregnation method at once solved.

Referring to the manufacturing process of the asphalt foam dispersed polyurethane foam according to the present invention in more detail.

In the present invention, as the polyol component, a polyol having a molecular weight in the range of 2000 to 6000, which is cheaper than the polybutadiene polyol, is used. As a result, the asphalt in the dispersion serves as an emulsifier that can be uniformly dispersed without solidifying even at room temperature. More preferably, as a polyol component, a mixture of 70 to 90% by weight of polypropylene glycol having a molecular weight of 4000 to 6000 and 10 to 30% by weight of polypropylene glycol having a molecular weight of 2000 to 3000 is used.

Asphalt is a final residue obtained by distillation under reduced pressure from crude oil. This mixture (Straight run Asphalt) is adhesive, water resistant, has high viscosity and elongation, and has excellent temperature sensitivity. In addition, there is a difference in the softening point according to the Penetration of the asphalt, in the present invention, when the asphalt dispersion polyol is prepared using asphalt of 30 to 120 range, preferably 40 to 80 range of penetration. Asphalt handling was easy. The amount of dispersion of the asphalt may vary depending on the required density of the product or its characteristic value, and is preferably dispersed in the range of 40 to 150 parts by weight based on 100 parts by weight of polypropylene glycol. If the amount of asphalt is less than 40 parts by weight, the asphalt content is low, so that the sound absorption and vibration damping properties are low. If the content is more than 150 parts by weight, the content is high, the asphalt may not be uniformly dispersed and some aggregates may occur. In addition, the process of emulsifying and dispersing asphalt in the polyol component is carried out while stirring at 200 ~ 300 rpm in the range of 90 ~ 120 ℃. If the dispersion temperature is less than 90 ℃, the viscosity of the asphalt is high, it becomes difficult to agitate the asphalt, and the dispersion of the asphalt is poor. If it exceeds 120 ℃, a lot of energy is consumed to melt the asphalt and the dispersion of the asphalt is poor. .

Since the dispersion prepared by the above method can be handled at room temperature, a foaming agent, a catalyst, a crosslinking agent, a foaming agent, and the like are added to the dispersion and mixed to prepare an asphalt blend pre-mixing polyol system in which asphalt is uniformly dispersed. If necessary, an asphalt blend pre-mixing polyol system in which asphalt is uniformly dispersed may be prepared by adding and mixing a blowing agent, a catalyst, a crosslinking agent, a foam stabilizer, etc. while maintaining the dispersion in a temperature range of from room temperature to less than 90 ° C. have.

As the blowing agent, water, an organic solvent or a mixed solvent thereof can be used. In this case, hydrocarbons, haloalkanes and the like are used as the organic solvent, and methylene chloride (CH ₂ Cl ₂ ) and dichlorofluoroethane (C ₂ H ₃ Cl ₂ F) are particularly preferable. The amount of blowing agent may vary depending on the required foam density. Preferably, the foaming agent contains 1.0 to 4.0 parts by weight of water, and 20 to 30 parts by weight of organic solvent, based on 100 parts by weight of the polyol component. When using a mixture of organic solvents, 2.5 to 3.5 parts by weight of water and 15 to 25 parts by weight of the mixture are used. If the content of the foaming agent is less than the above range, the asphalt particles are not uniformly dispersed in the polyurethane foam, but exhibit a property of solidifying even at room temperature. collapse occurs.

It is preferable to use an amine compound as a catalyst in terms of foaming reactivity control in foam production. As the amine catalyst, 1,4-diazabicyclo [2.2.2] octane (Dabco), N, N, N'- Trimethylaminoethylmorpholine bis (2-dimethylaminoethyl) ether and the like can be used. It is preferable to contain 0.5-3.0 weight part of catalysts with respect to 100 weight part of polyol components from a reactive and mold moldability viewpoint.

Ethylene glycol, dipropylene glycol, 1,4-butanediol, etc. are used as a crosslinking agent, and 1.0-7.0 weight part is used with respect to 100 weight part of polyol components.

As the foam stabilizer, a silicone-based surfactant is used, which is 0.3 to 0.7 parts by weight based on 100 parts by weight of the polyol component.

The polyurethane foam in which the asphalt of the present invention is dispersed is obtained by adding the isocyanate component to a foaming system containing an additive including a polyol component, asphalt, and a foaming agent as described above and foaming.

At this time, as an isocyanate component, aliphatic isocyanate compounds, such as 4,4'- diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, or aromatic diisocyanate are used. Particular preference is given to using those having an isocyanate content (NCO%) in the range of 25-50%. The isocyanate component is preferably used in the range of 20 to 40 parts by weight based on 100 parts by weight of the foaming system in view of foam formability.

As described above, the method for producing the polyurethane foam in which the asphalt is dispersed according to the present invention has the following advantages as compared to the impregnation method and the foaming method described in the prior art: (1) It is possible to mold without limitation in shape. (2) moderate elasticity retention, (3) vibration damping, sound absorption, suitable for soundproofing materials, (4) less leakage of asphalt components due to heat, (5) less contamination of parts in contact, (6) various foaming Magnification can be adjusted.

The present invention as described above will be described in more detail based on the following embodiments, but the present invention is not limited thereto.

Examples 1-9

Asphalt dispersion polyurethane foam was prepared under the same conditions as in Table 1 below.

To the polyol (Polyfunctional Polyether Polyol, Dongsung Chemical Co., Ltd.), straight asphalt (straight asphalt, penetration rate of 50-120, manufactured by Korea Petrochemical Co., Ltd.) was introduced into a mixed reactor at 110 ° C. and stirred at 200-300 rpm for 10 minutes at medium speed. After the temperature of the reactor was lowered to 80 ° C., additives including a blowing agent and an amine catalyst were added thereto, followed by medium speed stirring at 200 to 300 rpm for 10 minutes.

4,4'-diphenylmethane diisocyanate (Polymeric MDI, Suprasec 2027, manufactured by ICI, UK) was introduced into the foaming system prepared above, and stirred at 5000 rpm for 5 seconds at high speed. Was injected into the foam. At this time, the temperature of the raw material was maintained at 25 ~ 60 ℃, the temperature of the mold was 40 ~ 50 ℃, demolding after injection was opened and closed in 10-15 minutes.

TABLE 1

Example One 2 3 4 5 6 7 8 9 Polyol 1 ^a) 70 g 80 g 90 g 50 g 40 g 20 g 80 g 90 g 100 g Polyol 2 ^b) 30 g 20 g 10 g 50 g 60 g 80 g 20 g 10 g - asphalt 40 g 80 g 150 g 40 g 80 g 150 g 40 g 80 g 150 g blowing agent water 3.0 g 3.5 g 4.0g 2.5g 3.0 g 3.5 g 3.0 g 3.2 g 3.5 g CH ₂ Cl ₂ - - - 20 g 25 g 30 g - - - C ₂ H ₃ Cl ₂ F - - - - - - 15 g 20 g 25 g Amine catalyst ^c) 1.0 g 1.5 g 2.0 g 1.0 g 1.5 g 2.0 g 2.5g 3.0 g 3.5 g Foam stabilizers ^d) - - - 0.3 g 0.5g 0.7 g - - - Crosslinker ^e) - - - 3.0 g 5.0 g 7.0 g - - - Isocyanate 25 g 25 g 25 g 30 g 30 g 30 g 35 g 35 g 35 g a) Polyol 1: Molecular weight 4000 ~ 6000b) Polyol 2: Molecular weight 2000 ~ 3000 c) Amine Catalyst: Dabco, manufactured by Air Product of USA d) Foaming Agent: Silicone Surfactant, B-4113, Product of Goldschmidt, Germany e) Crosslinking Agent: Ethylene Glycol

Experimental Example 1 Measurement of Physical Properties of Polyurethane Foam

Physical properties of the polyurethane foam prepared in Examples 1 to 9 are shown in Table 2 below.

TABLE 2

Foam density ¹⁾ (g / cm 3) Tensile strength ²⁾ (㎏ / ㎠) Elongation ³⁾ (%) Tear strength ⁴⁾ (㎏ / ㎝) Foam shrinkage rate ⁵⁾ (mm) Example 1 0.18 4.5 110 1.25 0.70 Example 2 0.20 4.6 110 1.30 0.70 Example 3 0.22 4.6 115 1.30 0.65 Example 4 0.25 4.6 115 1.32 0.68 Example 5 0.28 4.7 120 1.35 0.68 Example 6 0.30 4.8 120 1.35 0.65 Comparative Example 1 0.30 3.1 90 - - Comparative Example 2 0.085 2.8 95 - - 1) According to JIS-K-6401 Clause 5.3) 2) According to JIS-K-6401 Clause 5.3) 3) According to JIS-K-6401 Clause 5.3) 4) According to JIS-K-6401 Clause 5.3) 5) Test condition: Poly Urethane foam thickness 10 ± 0.1 mm, after 24 hours at 70 ° C. Comparative Example 1: Japanese Patent Application No. 62-248628 Comparative Example 2 Comparative Example 2: Japanese Patent Application No. 62-248628 As Comparative Example 2 Asphalt Does not contain

Experimental Example 2 Measurement of Sound Absorption of Polyurem Foam

In order to compare the sound absorption rate of the polyurethane foam prepared in Example 8 and the conventional sound absorbing material, the following experiment was performed.

According to JIS A 1405 (Method for measuring vertical incidence absorbance by the in-tube method), the low frequency region was measured from 100 Hz to 1.6 KHz using the A tube using the BK equipment, and the high frequency region was 1 KHz to 6.2 using the B tube. Measured up to KHz. The results are shown in FIG.

According to Figure 1, the felt sound absorbing material (product of Chilsung Co., Ltd.) produced by the resin treatment of the recycled surface and synthetic fibers is superior in the overall frequency range compared to Aspitch Sheet ™ (product of TQ-1, Japan) manufactured by the impregnation method. Although the sound absorption rate is shown, it shows a low sound absorption rate compared with the integral foam asphalt foam. Calmphalt ™ (made by Bridgestone, Japan) is a polyurethane foam in which a polyol component dispersed in an asphalt and an isocyanate component is integrally foamed, and exhibits excellent sound absorption in the overall frequency range compared to Aspitch Sheet ™ and felt absorbents. There is a problem in that the additives to be used must be added separately. In addition, Aspitch Sheet ™ is an asphalt-impregnated polyurethane foam that exhibits a low defect rate of less than 0.1 sound absorption coefficient over the entire frequency range. On the other hand, the polyurethane foam in which the asphalt foam of Example 8 according to the present invention is dispersed exhibits excellent sound absorption in comparison with other products in the low and medium frequency range of 1,000 ㎐ or less.

As described above, in the case of the manufacturing method according to the present invention, asphalt is uniformly dispersed in the dispersion even at room temperature, so that the handling of the dispersion is easy, as well as the produced polyurethane foam has excellent sound absorption and viscoelasticity, thereby generating noise and vibration. Its use is not limited to soundproofing materials and sealing materials in automobiles and general industrial fields, and is particularly useful for engine parts of automobiles due to its excellent heat resistance, cold resistance, and water resistance.

Claims (9)

In the method for producing a polyurethane foam containing asphalt, Preparing a dispersion by emulsifying and dispersing 40 to 150 parts by weight of asphalt (penetration degree 30 to 120) to 100 parts by weight of a polyol component having a molecular weight in the range of 2000 to 6000, Adding 1.0 to 30 parts by weight of blowing agent and 0.5 to 3.0 parts by weight of amine catalyst to the dispersion to form a foaming system, and Method for producing an asphalt dispersed polyurethane foam, comprising the step of foaming by adding 20 to 40 parts by weight of the isocyanate component to 100 parts by weight of the foaming system. The method of claim 1, wherein the asphalt has a penetration degree in the range of 40 to 80. The method of claim 1 wherein the polyol component is asphalt dispersed poly, characterized in that the mixture of 70 to 90% by weight of polypropylene glycol in the range of 4000 to 6000 molecular weight and 10 to 30% by weight of polypropylene glycol in the range of 2000 to 3000 molecular weight. Method of producing urethane foam. The method of claim 1, wherein the blowing agent is water, an organic solvent or a mixture thereof. The method of claim 4 wherein the blowing agent is water, methylene chloride, dichlorofluoroethane or mixtures thereof. The method of claim 1, wherein the asphalt is emulsified and dispersed in the polyol component in the range of 90 ~ 120 ℃ asphalt production method of the dispersed polyurethane foam. The method of claim 1, wherein the foaming system forming process is carried out at room temperature to 90 ℃ range. 8. The method of claim 1, wherein ethylene glycol, silicone-based surfactants, or mixtures thereof are added during the foaming system formation process. Asphalt-dispersed polyurethane foam, characterized in that produced by the method of claim 1.

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