JP2005199504A - Aqueous mold release agent for polyurethane molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous mold release agent excellent in economical efficiency, safety, environmental properties and demolding properties and capable of enhancing the aesthetic appearance of the surface of a polyurethane foam. <P>SOLUTION: In the aqueous mold release agent for polyurethane molding containing at least a mold release active substance, a hydrocarbon solvent and an emulsifier, the total content of the hydrocarbon solvent component is set to 500-4,000 mass% of the total content of the mold release active substance and a dispersion form is set to an oil-in-water type. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

    The present invention relates to an aqueous release agent used for producing a polyurethane foam molded article.

  When manufacturing polyurethane foam molded products, a mold release agent is applied to the mold to prevent adhesion between the foam and the mold and to improve the appearance of the foam surface (skinless and free of roughness). There is a need to. Currently, a mold release agent used industrially contains a mold release active material such as wax or oil dispersed or dissolved in a medium. Depending on the medium, the release active is diluted to the optimum concentration for application to the mold. An organic solvent or water is used as the medium. However, since the medium affects the aesthetics of the foam surface, it is necessary to consider this point when selecting the medium.

  Currently, a mold release agent whose medium is mainly composed of an organic solvent is used. When the medium is only an organic solvent, it is not necessary to add an emulsifier, and the release active substance dissolves, so that a release film surface that is smooth and rich in water repellency is formed. Such a release film surface facilitates the demolding of the foam and further enhances the appearance of the foam surface. However, the use of a medium consisting only of an organic solvent is not preferable from the viewpoints of economy, safety and environmental protection.

  In particular, in recent years, interest in environmental protection has increased, and regulations on chemical substances have become stricter. Therefore, even in mold release agents, there is an increasing trend to reduce the use of volatile organic solvents as much as possible and to use water. However, if the release agent medium is only water, an emulsifier is required to disperse the release active substance, and the emulsifier density on the surface of the release film formed after coating becomes high. Therefore, there is a drawback that the surface of the foam is likely to be rough, and further, it is difficult to demold.

As a countermeasure, a water-in-oil dispersion system as disclosed in Patent Document 1 has been proposed. However, this method has a small water content and is insufficient from the viewpoint of economic efficiency and environmental protection. In addition, since the continuous layer is an organic solvent, there is a danger of ignition by fire, which is not preferable from the viewpoint of safety. Patent Document 2 proposes that the hydrophobicity improver is contained in an amount of 150 to 500% with respect to the releasable substance. However, with this amount, the ability to dissolve the emulsifier and the release active substance is insufficient, and the effect of improving the aesthetics of the foam surface is small.
Special Table 2002-516193 Japanese Patent No. 3297836

  Accordingly, an object of the present invention is to provide an aqueous release agent that is excellent in economic efficiency, safety, environmental suitability, and releasability, and that can improve the appearance of the polyurethane foam surface.

  As a result of intensive studies, the present inventors have solved the above problem by using a release agent as a specific component.

  According to the first aspect of the present invention, there is provided an aqueous mold release agent for polyurethane molding containing at least one release active substance, a hydrocarbon solvent, and an emulsifier, and the total of the hydrocarbon solvent components. Providing an aqueous mold release agent for polyurethane molding characterized in that the content is 500 to 4000 mass% of the total content of the release active substance and the dispersion form is an oil-in-water type. Solve.

  This release agent is in a form in which a high-concentration solvent-type release agent is dispersed in water with a small amount of emulsifier. When this is applied to the mold, the water first evaporates, and then the release active substance and a small amount of emulsifier dissolved in the organic solvent form a release film. Therefore, it is possible to form a release film surface with extremely low emulsifier density and high water repellency, and to provide an aqueous release agent that has performance equivalent to that of a solvent-type release agent in terms of release properties and aesthetics. It becomes possible to do. Further, since the amount of the organic solvent is set to the minimum amount capable of dissolving the release active substance and the emulsifier, it is advantageous in terms of economy and environmental suitability. Furthermore, since the dispersion form is an oil-in-water type, the organic solvent is surrounded by water, and there is little danger of fire and it is safe.

  Moreover, when the boiling point of the hydrocarbon solvent is 140 ° C. to 250 ° C., it is possible to provide a release agent excellent in the drying property of the release film and the dispersion stability of the release active substance. Thereby, the beauty | look of the shape | molded polyurethane foam surface can be improved more.

  Furthermore, since at least one emulsifier is an amine soap and the content of the fatty acid is set to a constant ratio with respect to the amount of the organic solvent, a smoother release film can be formed. And the aesthetics of the surface of the molded polyurethane foam can be improved.

  Furthermore, when a tertiary amine is added to the release agent, the curing speed of the surface of the polyurethane foam is improved, so that the surface roughness of the polyurethane foam can be improved and the appearance can be further improved.

  In addition, the amount of emulsifier can be further optimized to form a smoother release film by making the total content of fatty acids constituting the amine soap a certain ratio with respect to the release active substance amount. Can do.

  As described above, according to the first aspect of the present invention, there is provided an aqueous mold release agent for polyurethane molding containing at least one or more release active substances, hydrocarbon solvents, and emulsifiers. An aqueous mold release agent for polyurethane molding, wherein the total content of the hydrocarbon solvent component is 500 to 4000% by mass of the total content of the release active substance, and the dispersion form is an oil-in-water type To solve the above problems.

  This release agent is in a form in which a high-concentration solvent-type release agent is dispersed in water with a small amount of emulsifier. When this is applied to a mold, water is first evaporated, and then a release active substance and a small amount of emulsifier dissolved in an organic solvent form a release film. Therefore, it is possible to form a release film surface with extremely low emulsifier density and high water repellency, and to provide an aqueous release agent that has the same performance as a solvent-type release agent in terms of release properties and aesthetics. It becomes possible to do. Further, since the amount of the organic solvent is set to the minimum amount capable of dissolving the release active substance and the emulsifier, it is advantageous in terms of economy and environmental suitability. Furthermore, since the dispersion form is an oil-in-water type, the organic solvent is surrounded by water, and there is little danger of fire and it is safe.

  Moreover, when the boiling point of the hydrocarbon solvent is 140 ° C. to 250 ° C., it is possible to provide a release agent excellent in the drying property of the release film and the dispersion stability of the release active substance. Thereby, the beauty | look of the shape | molded polyurethane surface can be improved more.

  Furthermore, since at least one emulsifier is an amine soap and the content of fatty acid is set to a constant ratio with respect to the amount of organic solvent, a smoother release film can be formed. And the aesthetics of the surface of the molded polyurethane foam can be improved.

  Furthermore, when a tertiary amine is added to the release agent, the curing speed of the surface of the polyurethane foam is improved, so that the surface roughness of the polyurethane foam can be improved and the appearance can be further improved.

  In addition, the amount of emulsifier is further optimized to form a smoother release film by making the total content of fatty acids constituting the amine soap a certain ratio with respect to the release active substance amount. Can do.

  Such an effect of the present invention will become apparent from the best mode for carrying out the invention described below.

  The aqueous mold release agent for polyurethane molding of the present invention contains at least one release active substance, a hydrocarbon solvent and an emulsifier.

(A) Release active substance The release active substance of the present invention has low water solubility and forms a water-repellent surface (release film) at the interface between the mold and the polyurethane foam in the mold. It is a substance that makes it easy to release the foam. Examples of the release active substance include wax and oil, but the use of wax is preferable in that the foam surface is less rough and a skinless surface is easily formed. As the wax, natural and synthetic hydrocarbon waxes, modified products and oxides thereof, mineral and animal and plant waxes, modified products thereof and the like can be used. Specifically, examples of the hydrocarbon wax include paraffin wax, microstalline wax, ceresin wax, Fischer-Tropsch wax, polyethylene wax, and polyethylene polypropylene copolymer wax. Examples of the mineral wax include montan wax, and examples of the animal and plant wax include carnauba wax, candelilla wax, beeswax, wood wax, rice wax, hardened whale wax, hydrogenated castor oil wax, and hardened beef tallow. Among these, it is particularly preferable to use hydrocarbon waxes such as polyethylene wax and polyethylene polypropylene copolymer wax because a skinless surface with less roughness of the foam surface can be formed.

(B) Hydrocarbon solvents Examples of hydrocarbon solvents include aliphatic hydrocarbons such as octane, nonane, dodecane, and undecane, aromatic hydrocarbons such as tetralin, naphthalene, butylbenzene, and tetramethylbenzene, or mineral terpenes. And mixtures such as solvent naphtha. Among these hydrocarbon solvents, those having a boiling point in the range of 140 ° C. to 250 ° C. are preferably used. Use of a solvent having a boiling point of 250 ° C. or higher is not preferable because the drying property is inferior, and if it is 140 ° C. or lower, the solvent evaporates prior to water and the solubility of the release active substance is lowered. It is essential that the amount of the hydrocarbon-based solvent is 500 to 4000% by mass with respect to the release active substance. If it is 500% by mass or less, the release active substance is not sufficiently dissolved, a release film rich in water repellency cannot be formed, and the appearance of the foam surface is impaired, and if it is 4000% by mass or more, the release active substance is lost. On the other hand, the amount of emulsifier component required is too large, which impairs the appearance of the foam surface and is not preferable from the viewpoint of safety and environmental protection. In particular, 1000 to 3000 mass% is preferable from the viewpoint of improving the aesthetics of the foam surface and protecting the environment.

(C) Emulsifier Any emulsifier can be used as long as it can emulsify a release active substance or a hydrocarbon solvent in water as a medium, but an amine soap of a fatty acid composed of a fatty acid and an amine is preferably used. The fatty acid is particularly preferably a higher fatty acid. The higher fatty acid herein is a saturated or unsaturated fatty acid having 10 to 24 carbon atoms, and may be linear or branched. In this invention, it is preferable that the total content of a fatty acid is 0.5-5 mass% of the total content of a hydrocarbon solvent, and it is further more preferable that it is 2-4%. In addition, the total content is preferably 10 to 100% by mass of the total content of the release active substance. If the amount of the fatty acid is small, the emulsifying action is inferior, and if the amount of the fatty acid is too large, problems such as roughening of the foam surface and difficulty in demolding occur. Preferred amines that form amine soaps with fatty acids are secondary or tertiary amines. When there are two or more hydrogen atoms on the amine nitrogen atom as in the case of a primary amine, it is not preferable because it may react with the isocyanate of the polyurethane raw material to form a polymer. Specifically, dialkylamine, trialkylamine, morpholine and derivatives thereof, dialkylalkanolamine and the like are preferable. Also, triethylenediamine, N, N-dimethylcyclohexylamine, N, N-dimethyl-2-phenylamine, N, N, N ′, N′-tetramethylbutanediamine, N, N, N ′, N′-tetra Among tertiary amines such as methyl-1,6-hexanediamine, N-hexamethyltriethylenetetramine, N, N′-dimethylpiperazine, and ethylmorpholine, those used as urethane curing catalysts are foams. This is particularly preferable since the surface curing rate can be increased and surface roughness can be prevented. However, urethane curing catalysts are generally expensive and are preferably added in the minimum amount necessary as part of the amine. As the other emulsifier, an emulsifier having a low HLB value (hydrophile-lipophile ba1ance) can be used. Examples of the emulsifier having a low HLB value include polyhydric alcohol esters of higher fatty acids and ethylene oxide adducts of higher alcohols.
(D) Other

  In addition to the above main components, various additives can be added to the mold release agent of the present invention as needed within a range that does not impair the performance. Specific examples of the additive include antioxidants, preservatives, rust preventives, wetting agents and the like.

<1> Preparation of sample for evaluation (Example 1)
30 parts of mineral terpene (boiling point 151 to 178 ° C.), 2.7 parts of polyethylene wax (melting point 99 ° C.) and 0.2 part of stearic acid diglyceride are mixed and heated to 120 ° C. to dissolve the wax. This was mixed with a previously prepared amine soap solution (1.1 parts of stearic acid, 0.6 parts of morpholine and 0.2 parts of triethylenediamine in 65.2 parts of water heated to 95 ° C., and stirred uniformly. The pre-emulsified liquid is prepared by adding dropwise to the liquid dispersed in the solution. Furthermore, this was emulsified using a homogenizer and rapidly cooled to 40 ° C. to obtain a uniform emulsion composition.

(Example 2)
The following composition was prepared by the same production method as in Example 1.
Stearic acid 1.1 parts Morpholine 0.6 parts Triethylenediamine 0.2 parts Water 56.2 parts Mineral terpene (boiling point 141-172 ° C) 39.0 parts polyethylene wax (melting point 107 ° C) 1.7 parts ethylene propylene copolymer Combined wax (melting point 96 ° C.) 1.0 part stearic acid diglyceride 0.2 part

(Example 3)
The following composition was prepared by the same production method as in Example 1.
Stearic acid 1.1 parts Aminoethylethanolamine 0.6 parts Triethylenediamine 0.2 parts Water 36.2 parts Mineral terpenes (boiling point 154-197 ° C) 60.0 parts Polyethylene wax (boiling point 107 ° C) 1.8 parts stearin Acid diglyceride 0.1 parts

Example 4
The following composition was prepared by the same production method as in Example 1.
Stearic acid 0.7 parts Morpholine 0.4 parts Triethylenediamine 0.1 part Water 57.5 parts Mineral terpene (boiling point 151-178 ° C) 40.0 parts Polyethylene wax (melting point 107 ° C) 1.2 parts Stearic acid diglyceride 0 .1 part

(Comparative Example 1)
The following composition was prepared by the same production method as in Example 1.
Stearic acid 1.1 parts Morpholine 0.6 parts Triethylenediamine 0.2 parts Water 82.2 parts Mineral terpenes (boiling point 151-178 ° C) 13.0 parts Polyethylene wax (melting point 107 ° C) 2.7 parts Stearic acid diglyceride 0 .2 parts

(Comparative Example 2)
The following composition was prepared by the same production method as in Example 1.
Stearic acid 1.6 parts Morpholine 0.6 parts Triethylenediamine 0.2 parts Water 66.2 parts Mineral terpenes (boiling point 151-178 ° C) 30.0 parts Polyethylene wax (melting point 107 ° C) 1.3 parts Stearic acid diglyceride 0 .1 part

<2> Performance Evaluation The aqueous emulsion prepared above was applied to a polyurethane foam production mold heated to 70 ° C. by spraying so as to be 30 g / m ² . Thereafter, the polyurethane foam raw material was poured into the mold at a mold temperature of 65 ° C., covered, and cured in an oven at 100 ° C. for 10 minutes. Then, it took out and evaluated the surface roughness of a foam, mold release property, and cell open property (skinless state). The results are shown in Table 1.

As shown in Table 1, in the examples of the present invention, the surface roughness of the foam was small, and the releasability and cell openability were excellent. On the other hand, the amount of fatty acid is too much relative to the amount of organic solvent (Comparative Example 1), the amount of organic solvent is too small relative to the amount of release active substance (Comparative Example 1), and the amount of organic solvent is the amount of release active substance When the amount of fatty acid is too much (Comparative Example 2) and the amount of fatty acid is too much relative to the amount of the release active substance (Comparative Example 2), the surface of the foam is roughened and the releasability is poor It was.

Claims (6)

An aqueous mold release agent for polyurethane molding containing at least one release active substance, a hydrocarbon solvent, and an emulsifier, wherein the total content of the hydrocarbon solvent components is the total of the release active substances. An aqueous mold release agent for polyurethane molding, characterized in that the content is 500 to 4000% by mass and the dispersion form is an oil-in-water type. The aqueous mold release agent for polyurethane molding according to claim 1, wherein the boiling point of the hydrocarbon solvent is 140 to 250 ° C. At least one of the emulsifiers is an amine soap composed of a fatty acid and an amine, and the total content of the fatty acid is 0.5 to 5% by mass of the total content of the hydrocarbon solvent. Item 3. An aqueous mold release agent for polyurethane molding according to Item 1 or 2. The aqueous mold release agent for polyurethane molding according to claim 3, wherein the total content of the fatty acids constituting the amine soap is 2 to 4% by mass of the total content of the hydrocarbon solvent. The aqueous mold release for polyurethane molding according to claim 3 or 4, wherein the total content of the fatty acids constituting the amine soap is 10 to 100% by mass of the total content of the release active substance. Agent. The water-based mold release agent for polyurethane molding according to any one of claims 1 to 5, wherein the water-based mold release agent for polyurethane molding contains a tertiary amine.