JP4647265B2 - Water repellent polyurethane resin foam - Google Patents

Description

  The present invention relates to a lightweight water-repellent polyurethane resin foam.

  Water-repellent polyurethane resin foams are widely used in various fields such as automobiles, home appliances, and houses. Conventionally, as a water-repellent polyurethane resin foam, one impregnated with a fluorine-based water repellent or one prepared by adjusting the raw material composition of the blend is known. Further, the water-repellent polyurethane resin foam is required to be lightweight depending on the application.

  As a conventional lightweight water-repellent polyurethane resin foam, 60 parts by weight or more of MDI-based isocyanate is used as isocyanate with respect to 100 parts by weight of PPG-based polyol as polyol, and isocyanate or polyol and reactive groups are used as foam stabilizers. There are those having an organometallic catalyst as a catalyst, those having an active hydrogen that reacts with an isocyanate group as a crosslinking agent, and those using 3 parts by weight or more of water as a blowing agent.

However, the conventional lightweight water-repellent polyurethane resin foam has a high density of 35 kg / m ³ or more, and further lightness is required depending on the use of the water-repellent polyurethane resin foam.
JP 2002-338944 A JP-A-10-176074

  This invention is made | formed in view of the said point, Comprising: The water-repellent polyurethane resin foam which is excellent in lightweight property and exhibits favorable water repellency is provided.

The invention of claim 1 is a water-repellent polyurethane resin foam obtained by foaming a blend containing a polyol, a foaming agent, a catalyst, a water repellent and an isocyanate, and the polyester includes a polyester polyol and a polyester polyether polyol. see, water comprises 2.5 to 6 parts by weight as the foaming agent when the polyol is 100 parts by weight, the density of the water-repellent polyurethane resin foam is 10 to 30 kg / ^{m 3,} the water repellent Is an ester comprising a conjugate of a monoalcohol having 14 to 36 carbon atoms and an aliphatic or alicyclic dicarboxylic acid having 15 to 36 carbon atoms,
When the polyol is 100 parts by weight, the polyester polyol is 3 to 60 parts by weight, the polyester polyether polyol is 40 to 97 parts by weight, and the water repellent is 25 to 80 parts by weight. .

  According to the present invention, by using a polyester polyol, the dispersibility of the water repellent is excellent, the viscosity of the compound can be adjusted, the foam becomes low density, and the polyester polyether copolymer polyol is used. By doing so, the strength of the foam is increased, the hydrolysis resistance is improved, and good water repellency is exhibited.

  In the present invention, as the polyol, a polyester polyol and a polyester polyether polyol are used in combination.

  As the polyester polyol, those known for polyurethane resin foams are used. For example, aliphatic carboxylic acids such as malonic acid, succinic acid and adipic acid, and aromatic carboxylic acids such as phthalic acid, ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,6-hexanediol, 2,5-hexane Obtained by polycondensation with polyols such as diol, 3-methyl-1,5-pentanediol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, diglycerin, sorbitol, sucrose And lactone polyols. In the present invention, by using the polyester polyol, the dispersibility of the water repellent is improved, the viscosity of the blend can be adjusted, and the foam can be made to have a low density.

  Known polyester polyether polyols can be used. For example, an esterification reaction or transesterification reaction is performed using an aliphatic dicarboxylic acid or an ester-forming derivative thereof and a low-molecular diol, and a polycondensation reaction is performed, or a polyester polyol and polytetramethylene glycol are transesterified. What was obtained by making it to be mentioned can be mentioned. In the present invention, the use of the polyester polyether polyol increases the strength of the foam, improves the hydrolysis resistance, and exhibits good water repellency.

  When the polyol is 100 parts by weight, the polyester polyol and the polyester polyether polyol are 3 to 60 parts by weight, more preferably 15 to 35 parts by weight for the polyester polyol, and 40 for the polyester polyether polyol. It is made into -97 weight part, More preferably, it is 65-85 weight part. When the amount of the polyol is 100 parts by weight, when the amount of the polyester polyol is more than 60 parts by weight, the number of ether chains in the polyurethane crosslinked body is reduced, and the strength and hydrolyzability of the foam are deteriorated. On the other hand, when the amount of the polyester polyol is less than 3 parts by weight, the compatibility between the water repellent and the polyester polyol is deteriorated and a good foam cannot be obtained.

  As the foaming agent, water is suitable. The amount of water is preferably 2.5 to 6 parts by weight when the polyol is 100 parts by weight. In the present invention, it is not necessary to use a foaming aid such as methylene chloride.

  As the catalyst, an amine catalyst such as triethylamine or tetramethylguanidine, a tin catalyst such as stannous octoate, or a metal catalyst (also referred to as an organometallic catalyst) such as phenylmercurypropionate or lead octenoate is used. be able to. The general amount of the catalyst is 0.01 to 2.0 parts by weight when the polyol is 100 parts by weight.

  As the water repellent, an ester is used. The ester is preferably a conjugate of a monoalcohol having 14 to 36 carbon atoms and an aliphatic or alicyclic dicarboxylic acid having 15 to 36 carbon atoms. Examples of the C14-36 monoalcohol include myristyl alcohol, cetyl alcohol, stearyl alcohol, eicosyl alcohol, saturated monoalcohol such as seryl alcohol and isostearyl alcohol, and unsaturated monoalcohol such as oleyl alcohol. Examples of the aliphatic or alicyclic dicarboxylic acid having 15 to 36 carbon atoms include aliphatic dicarboxylic acids such as tabic acid and alicyclic dicarboxylic acids such as dimer acid. By setting the carbon number of the monoalcohol to 14 to 36 and the aliphatic or alicyclic dicarboxylic acid to a carbon number of 15 to 36, the water repellency of the obtained foam is further improved. The amount of the water repellent is 25 to 80 parts by weight, more preferably 30 to 50 parts by weight when the polyol is 100 parts by weight. If the amount of water repellent is less than 25 parts by weight per 100 parts by weight of polyol, sufficient water repellent effect cannot be obtained, and if the amount of water repellent exceeds 80 parts by weight, the water repellent is a plasticizer. It becomes difficult to form a foam.

  As a particularly preferable ester as the water repellent in the present invention, dimer acid distearyl can be mentioned. The dimer acid distearyl is synthesized as follows. First, dimer acid and stearyl alcohol are mixed at a molar ratio of 1: 2, stirred while introducing nitrogen gas into the reaction vessel, the temperature is raised to 150 to 180 ° C., and the mixture is left in that state. At that time, the inside of the reaction vessel is depressurized to 20 mmHg to remove moisture. After one and a half hours, 0.2 to 0.8 g of a catalyst selected from p-toluenesulfonic acid, calcium acetate, calcium octylate, dibutyltin dilaurate and stannous octylate is added per mole of dimer acid. About 2 hours after the standing, when the acid value of the reaction product becomes 5.0 or less, the reaction is completed, and then the temperature is lowered to room temperature, thereby obtaining distearyl dimer acid.

  As the polyisocyanate, aliphatic or aromatic polyisocyanates having two or more isocyanate groups, mixtures thereof, and modified polyisocyanates obtained by modifying them can be used. Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexamethane diisocyanate. Examples of the aromatic polyisocyanate include toluene diisocyanate (TDI), diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, Examples thereof include polymeric polyisocyanate (crude MDI). Other prepolymers can also be used. In addition, auxiliary agents such as foam stabilizers, colorants, flame retardants and the like may be added as appropriate.

The water-repellent polyurethane resin foam is produced by a known foaming method in which a mixture containing the required amounts of the respective raw materials is mixed and reacted with a stirrer. The density of the water repellent polyurethane resin foam is 10 to ³⁰ kg / m ³ .

  Examples of the present invention will be specifically described below. The water repellent polyurethane resin foams of Examples 1 to 5 were produced by stirring and mixing the blends composed of the blends shown in Table 1 according to a conventional method and foaming. In Table 1, polyester polyol is Sanyo Chemical Industries, AH-405, polyester polyether polyol is Mitsui Takeda Chemical Co., Ltd., L-50, water repellent is distearyl dimer acid, amine catalyst is Japan Emulsifier Stock N, N-dimethylaminoethanol (DMAE) manufactured by company, metal catalyst is organic acid metal tin salt (stannas octoate), foam stabilizer is manufactured by Torre Silicone Co., Ltd., SH-193, polyisocyanate is Nippon Polyurethane Co., Ltd. Company-made T-80 was used.

For comparison, as shown in Table 2, Comparative Example 1 and Comparative Example 2 in which the amounts of the polyester polyol and the polyester polyether polyol deviate from those of Claim 1, and the amount of the water repellent deviates from the amount of Claim 1. Comparative Example 3 and Comparative Example 5 and Comparative Example 4 in which the amount of water deviates from the amount of Claim 1 were produced in the same manner as the Example. In Comparative Example 3, foaming did not occur normally and a foam was not obtained.

  The foams of Examples 1 to 5 and Comparative Examples 1, 2, 4, and 5 thus produced were measured for density, 25% hardness, tensile strength, and elongation according to JIS K 6400. The water repellency test was conducted as follows. First, a 300 × 70 × 30 (thickness) mm test piece was cut from the foams of Examples and Comparative Examples, and the weight (a) of the test piece was measured. Next, as shown in FIG. 1, the test piece is placed on the bottom of the water tank, and a metal mesh having an opening at the bottom is covered from above the test piece, and a weight is placed on the metal mesh. It was injected so that After leaving in this state for 24 hours, remove the test piece from the water tank, place it on a wire mesh, drain the test piece, measure the weight of the test piece when the water contained in the test piece stops flowing down, and repel the water. When the difference from the weight (a) of the test piece before the water test was equal to or less than the value (a), the water repellency was evaluated as good (O). Tables 1 and 2 show the measurement results. Further, whether or not a good foam was obtained and whether or not streaks due to poor stirring were observed on the foam surface were also shown in Tables 1 and 2.

  In each of Examples 1 to 5, the moldability and stirring and mixing properties were good, and the lightness and water repellency were also good. On the other hand, Comparative Example 1 and Comparative Example 2 were inferior in water repellency due to the small amount of polyester polyol and a large amount of polyester polyether polyol, and poor stirring occurred. In Comparative Example 3, since the amount of the water repellent was large, molding failure occurred and a foam was not obtained. Moreover, since the comparative example 4 had little quantity of water, its density was high and it was inferior to the lightweight property. Comparative Example 5 was inferior in water repellency due to the small amount of water repellent.

It is the schematic which shows the state at the time of a water repellency test.

Claims (1)

Polyols, blowing agent, catalyst, a water repellent polyurethane foam obtained by foaming a formulation comprising a water repellent agent and a polyisocyanate, seen including a polyester polyol and a polyester polyether polyol as the polyol,
When the polyol is 100 parts by weight, the foaming agent contains 2.5 to 6 parts by weight of water, and the density of the water-repellent polyurethane resin foam is 10 to ³⁰ kg / m ³ ,
The water repellent is an ester composed of a combination of a monoalcohol having 14 to 36 carbon atoms and an aliphatic or alicyclic dicarboxylic acid having 15 to 36 carbon atoms,
When the polyol is 100 parts by weight, the polyester polyol is 3 to 60 parts by weight, the polyester polyether polyol is 40 to 97 parts by weight, and the water repellent is 25 to 80 parts by weight. Water repellent polyurethane resin foam.

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