JP3297836B2 - Aqueous release agent composition for polyurethane foam molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In a method for producing a polyurethane foam by a cold curing process, an object of the present invention is to provide a urethane foam having excellent cell openness on the surface of a molded product.

[0002] The reason why the surface of a molded article is required to be cell-open is not only to improve the appearance of the molded article, but also in the case of a sheet in which the skin such as a cloth wrapping the molded article is adhered with an adhesive. This is to improve the adhesiveness between the skin and the skin.

For example, in the case of a sheet for bonding a molded product having a concave center portion and a skin surrounding the molded product, such as a bucket sheet,
If a skin is formed on the surface of the molded product, (a) the adhesive force of the adhesive becomes weak due to the effect of the release agent attached to the skin layer, and the urethane foam and the skin become kinked when used for practical use. Even if peeling (interfacial destruction) or (b) the adhesion between the skin and the skin layer is sufficient, in this case, the anchor effect of the adhesive obtained when the cell is opened cannot be obtained due to the effect of the skin layer, and the skin layer Only peeling (material destruction)
Problem. However, when the surface is cell open, the adhesive enters the cells of the urethane foam, and the molded body adheres firmly to the skin. In addition, the cell-open foam does not rupture the molded product in the crushing process (a process for improving the continuity of the molded foam and reducing the shrinkage of the molded product).

[0004]

2. Description of the Related Art In a cold cure process, a polyurethane foam molded product is prepared by applying a release agent to the inner surface of a mold at 40 to 80 ° C., injecting a urethane raw material, curing, and then removing the molded product from the mold. It is obtained by demolding. The so-called solvent-based mold release agent, which is mainly composed of various types of waxes and dispersed in a hydrocarbon solvent, is generally used as the mold release agent. Was relatively easy. However, recently, various types of aqueous release agents have been proposed because of problems such as flammable explosiveness, danger and working environment of the solvent.

[0005]

However, polyurethane foams using these aqueous release agents are unlikely to have cell open properties. In addition, the releasability may be insufficient. Even if the constituent solvent of the conventional solvent-based mold release agent is simply replaced with water and molded using an emulsified aqueous mold release agent, no cell openness is imparted to the mold release surface of the molded article. As a reference example, Table 1 shows an example in which the cell-opening property is not obtained only by replacing the solvent in the solvent-based release agent with water, and the releasability decreases.
In addition, the performance evaluation test method followed the method described on page (0030). Although morpholine stearate is not required as a component in the solvent-based release agent, the same amount as that in the aqueous release agent was added to the solvent-based release agent in order to clarify the difference between the solvent and water.

[0006]

[Table 1]

[0007]

In the present invention, as a result of studying various factors that give cell openness, a hydrophobicity improver represented by an organic solvent in a state where a mold releasing substance is applied to a mold is shown. If an appropriate amount of Note 1) is present, this will molecularly orient the release material regularly, and as a result will significantly improve the hydrophobicity of the release material application surface, and will have excellent cell openness on the release surface of molded products. Found to give sex.

Note 1: The hydrophobicity improver corresponds to an organic compound having an organic property of 100 or more and an inorganic property of 50 or less in an organic conceptual diagram. The organic or inorganic value of the organic compound can be determined by the following formula based on the number of atoms or the number of functional groups contained in the compound, the bonding mode of the elements, and the like.

Organic value = number of carbon atoms × 20 + number of chlorine atoms × 80 + number of bromine atoms × 60−number of iso bonds of carbon atoms ×
10-number of tertiary bonds of carbon atoms x 20 inorganic value = number of aromatic rings x 15 + number of cyclo rings x 10 + number of carbon double bonds x 2 + number of chlorine atoms x 10 + number of bromine atoms x 1
0 + OH number × 100 + ether number × 20 Reference book: Yoshio Koda, “Organic Conceptual Diagram-Basics and Applications”, Sankyo Publishing (1984)

[0010] Further, in applying the hydrophobicity improver, an aqueous release agent is applied to a mold, and conditions in each step from formation of a film; Step 1: from the applied aqueous release agent composition First, it is necessary to evaporate the water and then the hydrophobic improver, and the hydrophobic improver must have a certain high boiling point. Step 2: Since the hydrophobicity improver evaporates from the coexistence state with the release material to promote the orientation of the release material, an appropriate amount of the hydrophobicity improver is required. Step 3: When the hydrophobicity improver remains in the formed film, the film itself has low hydrophobicity and does not have a sufficient hydrophobic surface. Therefore, the boiling point must be such that the hydrophobicity improver does not remain. And other requirements must be met. For this purpose, the amount and preferably the boiling point of the hydrophobicity improver used must be determined appropriately. As a result of studying to satisfy these conditions, an invention of an aqueous release agent composition for cell-opening polyurethane foam molding was completed.

[0011] Several aqueous release agents have been proposed in place of solvent-based release agents, which give cell-opening properties to polyurethane foam molded products. For example, an aqueous release agent obtained by emulsifying a mixture of a wax containing an ethylene / propylene copolymer wax and a small amount of an organic solvent with a mixture of an amine salt of stearic acid and an adduct of a secondary fatty acid alcohol and ethylene oxide (Japanese Patent Laid-Open No. No. 2,226,752) aims at cell openness by adding a nonionic surfactant to improve the emulsion stability of the composition. However, although the effect of improvement is recognized, the degree of cell open is still insufficient. In addition, the surface of the molded product is rough.

For example, an aqueous release agent obtained by dispersing a mixture of specific waxes in water using an emulsifier (Japanese Patent Publication No. Hei 6-28865) improves cell openability by compounding a wax having a specific melting point. However, the cell openness of molded products is still insufficient.

[0013]

DISCLOSURE OF THE INVENTION The present invention provides an aqueous emulsion comprising a mold for urethane molding heated to a temperature of 40 to 80 ° C. and a releasable substance used at the time of conventional urethane foam molding, to which a hydrophobicity improver is added. Is sprayed or brushed, and after 30 seconds to 2 minutes, the urethane raw material is poured into a mold, and cured at a temperature of 40 to 80 ° C. for 5 to 15 minutes, and the molded product is released from the mold.

[0014] Hydrophobic improver: The amount of the hydrophobic improver is preferably 150 to 5 parts by weight per 100 parts by weight of the release material.
00 parts by weight. If the addition amount is less than 150 parts by weight, the regular molecular arrangement of the release material cannot be sufficiently performed, and the cell-opening property of the molded product deteriorates. If the addition amount exceeds 500 parts by weight, an additional emulsifier required for emulsification is required, which adversely affects the emulsifier and lowers the cell openness of the molded product.

As the hydrophobicity improver used in the present invention, an organic compound having a boiling point of 150 to 250 ° C. is suitable.
For example, (a) hydrocarbons include nonane, decane,
(B) halides such as unbenzene, tetralin, isopropylbenzene, cyclohexylbenzene, paraffin-based hydrocarbon mixtures (10 to 13 carbon atoms), and naphthenic hydrocarbon mixtures (11 to 13 carbon atoms);
(C) ethers such as chlorotoluene, hexachloroethane, trichlorobenzene, bromobenzene, octyl bromide and the like include anisole, phenetole, cresyl methyl ether, ethyl benzyl ether, butyl phenyl ether and the like; These compounds may be used in a mixture. More preferred are (a) hydrocarbons, and among them, naphthenic hydrocarbons, and mixtures of paraffinic and naphthenic hydrocarbons are even more preferred.

When the boiling point of the hydrophobicity improver is less than 150 ° C., the hydrophobicity improver evaporates faster than water in the process of forming the release agent film, and the hydrophobicity of the release agent film becomes insufficient. If the boiling point of the hydrophobicity improver exceeds 250 ° C., the hydrophobicity improver remains in the release agent film, and the cell is roughened, voids are generated, and the release property is deteriorated.

Releasable substance: The releasable substance referred to in the present invention includes, for example, linear polyethylene wax, high-purity purified paraffin wax, Fischer-Tropsch wax and the like. The average molecular weight of the linear wax is preferably from 500 to 1,000. More preferably, the content is 50% or more based on the whole release material. Carnauba wax, montan wax, microcrystalline wax, branched polyethylene wax,
Silicone and the like can be used, but their mixing ratio is 50
% Is preferred.

Emulsifier: The emulsifier used in the present invention may be any one which usually emulsifies waxes. That is, an anionic activator, a cationic activator, a nonionic activator and the like are used.

Other components: Further, the aqueous release agent according to the present invention may contain a small amount of a conventional additive such as a bactericide, a foam stabilizer, a wetting agent, a leveling agent, an antifoaming agent and the like.

A method for producing an aqueous emulsion ; an example of a method for producing an aqueous emulsion of the present invention will be described below. First, a release material, a hydrophobicity improver, and other components are added.
Heat and mix at 10-120 ° C. This is gradually added to an emulsifier aqueous solution heated to 90 ° C. or higher while stirring with a homomixer to form an emulsion. Subsequently, this is treated with a homogenizer to form an emulsion of finer particles. The resulting emulsion is cooled to room temperature to make a stable emulsion composition. In the above method, the releasable substance, the hydrophobicity improver, and other components may be separately emulsified and then mixed.

[0021]

EXAMPLES In order to clarify the present invention, examples are shown in Tables 2, 3, 4, 5 and 6, and comparative examples are listed in Tables 7, 8 and 9. However, the following examples are a part of the present invention and do not limit the present invention in any way. In addition, the part in an Example shows a weight part.

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

[0025]

[Table 5]

[0026]

[Table 6]

[0027]

[Table 7]

[0028]

[Table 8]

[0029]

[Table 9]

Performance Test Method In order to clarify the performance effects of the present invention, the following performance tests were performed on Examples and Comparative Examples. (1) Application of release agent An iron box-shaped mold (inner dimensions: 15 cm long, 20 cm wide,
(5 cm deep, with lid with handle) was heated to 60 ° C., and the release agent composition was uniformly sprayed with an air gun (about 5 cm ² per m ^2).
0 g) and dry for 1 minute. (2) Polyurethane foam molding A polyol (MS-300 manufactured by Mitsui Toatsu) was used as raw material.
0 parts and 20 parts of TDI / MDI = 1/1 at room temperature 200
Stir and mix at 0 rpm for 5 seconds, immediately pour into a mold, close the lid and react at 60 ° C. The mold is placed in a thermostat at 60 ° C. and left for 10 minutes including the curing time. (3) Evaluation of mold releasability Set a spring scale on the handle of the mold lid and open the lid. Measure the load applied at that time. Evaluation criteria: は is 5 kg or less; は is 5 to 10 kg;
0 to 15 kg; × is 15 kg or more. (4) Evaluation of Cell Openness of Molded Foam The number of all cells within a 5 cm × 5 cm square of the surface of the molded urethane foam and the presence or absence of cell breakage are visually measured. The cell open ratio is defined as the ratio of the number of foam cells to the total number of cells. The cell openness is preferably 60% or more. Evaluation criteria: Cell open ratio: ◎ is 80% or more; は is 6
0 to 80%; Δ is 40 to 60%; X is 40% or less, or the cell is not open. (5) Evaluation of Finish of Molded Foam Surface The surface roughness of the molded foam is visually evaluated. Evaluation criteria: ○: no cell roughness; Δ: cell roughness; ×: severe cell roughness. Table 10 (Example) and Table 11 (Comparative Example)
Shown in

[0031]

[Table 10]

[0032]

[Table 11]

[0033]

The method using the aqueous release agent for cell-opening polyurethane foam molding of the present invention, compared with the method using the conventional aqueous release agent, has not only the cell-opening property but also the releasability and the surface. Both skin roughness properties were significantly improved.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 33/00-33/76

Claims (5)

(57) [Claims] Per 100 parts by weight of 1. A mold release material, Na
Futenic hydrocarbon mixtures or paraffinic hydrocarbons
An aqueous release agent composition for cell-opening polyurethane foam molding, comprising adding 150 to 500 parts by weight of a hydrophobicity improver composed of a mixture of styrene and a naphthenic hydrocarbon and emulsifying and dispersing the mixture. 2. The aqueous release agent composition for cell-opening polyurethane foam molding according to claim 1, wherein the naphthenic hydrocarbon mixture has 11 to 13 carbon atoms. 3. The cell open according to claim 1, wherein the paraffinic hydrocarbon mixture has 10 to 13 carbon atoms, and the naphthenic hydrocarbon mixture has 11 to 13 carbon atoms. Aqueous release agent composition for molding polyurethane foam. 4. The boiling point of the hydrophobicity improver is 150 to 25.
Being an organic compound in the range of 0 ° C.,
The aqueous release agent composition for molding a cell-open polyurethane foam according to any one of claims 1 to 3. 5. The cell openness according to claim 1, wherein the hydrophobicity improver is an organic compound having an organic property of 100 or more and an inorganic property of 50 or less. An aqueous release agent composition for molding polyurethane foam.