JPH07109369A - Production of water-shielding polyurethane foam - Google Patents

Abstract

PURPOSE:To obtain a water-shielding polyurethane foam having water-shielding performance and low gas-permeability by using a specific polyol and a foam stabilizer consisting of a specific silicone. CONSTITUTION:The urethane foam is composed of (A) a polyhydroxyl compound, (B) an isocyanate, (C) a foaming agent, (D) a catalyst and (E) a foam stabilizer. The component A is a polyolefin polyol and the component E is a carboxy-modified organosilicone such as a compound of the formula I [R1 is group of the formula II or the formula III (R' is H, 1-5C alkyl, aminocarbonylalkyl, halogenocarbonylalkyl or alkoxycarbonyl; (n) is 1-10; (n') is 1-20; (a) and (b) are 1-50; the molar ratio of a/b is 3/1 to 1/3); (x) is l-300; (y) is 1-25]. The amount of the component E is preferably 0.3-5 pts.wt. based on 100 pts.wt. of the component A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has low air permeability and
The present invention relates to a method for producing a flexible or semi-rigid open-cell polyurethane foam having a water blocking property.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
As a method for producing a soft or semi-rigid open-cell polyurethane foam having low air permeability and waterproofness, (1) a method of impregnating a soft or semi-hard open-cell polyurethane foam with a volatile solution of asphalt and drying, (2)
Sealing of soft or semi-rigid open-cell polyurethane foam by combining at least one of polydiene-based polyol, dimer acid polyol, and polyol in which 90% mol or more of alkylene oxide having 3 or more carbon atoms is added and polymerized with a hydroxyl group-containing organosilicone. For producing a material (Japanese Patent Publication No. 2-55470),
(3) A method for producing a polyurethane foam sealing material having a polyolefin skeleton as a polyol (Japanese Patent Laid-Open Publication No. 6-58242).
3-27583), and (4) a method for producing a saturated hydrocarbon resin skeleton polyurethane foam sealing agent using a hydroxyl group-containing reactive silicone (JP-A-2-298574).
No. gazette) is known.

However, in these methods, as for (1), the problems of environmental pollution by the solvent even in the drying step, productivity of foam and the phenomenon of thinning of meat after foaming, and (2) high density of foam (40 kg) / M ³ ), there is no problem in appearance, but in the low density region, void-like pinholes occur in the foam or cracks occur,
The problems (3) and (4) are not economical.

Further, conventionally, in the case of producing a flexible or semi-rigid open-cell polyurethane foam, generally, a polyether or polymer polyol mainly composed of propylene oxide having a molecular weight of 450 to 8000 is tolylene diisocyanate and a blowing agent. Although foaming is performed using a foam stabilizer, it is relatively easy to produce a foam having low air permeability depending on the type of polyol or the type or amount of amine catalyst selected at this time, No water blocking effect can be expected.

Further, Japanese Patent Application Laid-Open No. 60-245623 discloses a method of obtaining a flexible polyurethane foam having a low air permeability from a mixture containing a polyether polyol and a carboxyl-modified organosilicone. Is still insufficient.

Further, Japanese Patent Publication No. 1-38152 discloses the use of an organosilicone compound based on a polydialkylsiloxane having a primary or secondary amino group as a foam stabilizer. However, the water-stopping property of this is also insufficient.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a polyurethane foam having a low air permeability and a water blocking effect by using a specific polyol and a foam stabilizer. To do.

[0008]

Means and Actions for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that a polyolefin polyol is used as a polyhydroxyl compound (polyol) and a carboxy-modified organosilicone is used as a foam stabilizer. When used, a soft or semi-rigid polyurethane foam with low air permeability and sufficient water blocking effect can be obtained, and by using the above silicone, for example, in the case of a molded product that is foamed in a mold, Since the liquid easily spreads even in the mold, it also has the effect of preventing voids and cracks.In the foaming process of the soft block, the time from the reaction start to the end can be controlled, so the rise pattern can be changed.
The inventors have found that the present invention has excellent effects on shape control and squareness, and have completed the present invention.

Accordingly, the present invention uses a polyolefin polyol as the polyhydroxyl compound in a method of making a flexible or semi-rigid polyurethane foam from a formulation containing a polyhydroxyl compound, an isocyanate, a blowing agent, a catalyst and a foam stabilizer. At the same time, there is provided a method for producing a water-proof polyurethane foam, which comprises using a carboxy-modified organosilicone as a foam stabilizer.

The present invention will be described in more detail below.

The method for producing the water-proof polyurethane foam of the present invention uses a blend comprising a polyhydroxy compound (polyol), an isocyanate, a foaming agent, a catalyst, a foam stabilizer and other additives which are optionally added. When producing an open-celled flexible or semi-rigid polyurethane foam, a polyolefin polyol is used as the polyol and a silicone modified with a carboxylic acid is used as the foam stabilizer to obtain a soft or semi-rigid open-celled polyurethane foam. It is about the method.

Here, the polyolefin polyol is a hydrogenated product such as polyisoprene or polybutadiene having at least two or more hydroxyl groups in one molecule and has a saturated hydrocarbon skeleton in the molecular skeleton and a number average molecular weight of 1000-5000, especially 2000-4000 polyols are preferably used.

In this case, in addition to the polyolefin polyol, a polyether polyol or a polyester polyol usually used for producing a flexible or semi-rigid polyurethane foam can be used in combination within a range not impairing the object of the present invention. The amount of the polyolefin polyol used is preferably 20 to 100% by weight, more preferably 50 to 100% by weight, based on the entire polyhydroxyl compound (polyol).

As the carboxy-modified organosilicone, those represented by the following formulas (1) to (4) are preferably used.

[0015]

[Chemical 1](However, R ₁Is C_nH_2nO (C₂H_FourO)_a(C₃H₆O)_bC
_{n '}H_{2n '}COOR 'or C_nH_2nO (C₂H_FourO)_a(C₃
H₆O)_bOC_{n '}H_{2n '}COOR ', R'is hydrogen source
Child, alkyl group having 1 to 5 carbon atoms, amino having 1 to 5 carbon atoms
Carbonylalkyl group, halogen carbo having 1 to 5 carbon atoms
Nylalkyl group, alkoxycarbonyl having 1 to 5 carbon atoms
An alkyl group or salt is shown. Also, x is 1 to 300 and y is
1 to 25, n is 1 to 10, n'is 1 to 20, and a and b are 1
˜50 and a and b are in a molar ratio of 3/1 to 1/3
Respectively. )

[0016]

[Chemical 2](However, R₂Is C _nH_2nO (C₂H_FourO)_a(C₃H₆O)_bC
_{n '}H_{2n '+ 1}And R ', x, y, n, n', a, b are
It has the same meaning as above. )

[0017]

[Chemical 3] (However, R ₁ , R ₂ , x, and y are the same as described above.)

[0018]

[Chemical 4] (However, R ₃ represents C _n H _2n , and the others are the same as the above.)

The amount of the silicone (foam stabilizer) blended is preferably 0.3 to 5 parts, and more preferably 0.5 to 2 parts, relative to 100 parts (parts by weight, the same applies hereinafter) of the polyhydroxyl compound. 5 copies. If the amount of the silicone compounded is less than 0.3 part, the foam regulation ability is lowered, and it is difficult to obtain a foam having a good appearance. If it is more than 5 parts, the proportion of closed cells in the foam is increased, and a good foam cannot be obtained. There are cases.

In the present invention, as the components other than the above polyhydroxyl compound and silicone (foam stabilizer), known compounds used for the production of flexible polyurethane foam or semi-rigid polyurethane foam can be used.

Specific examples of the isocyanate compound include tolylene diisocyanate, polymethylene polyethylene polydiisocyanate, hexamethylene diisocyanate, 1,5-naphthalene diisocyanate, xylene diisocyanate and isophorone diisocyanate. Is used.

The amount of the isocyanate compound blended is preferably 20 to 75 parts with respect to 100 parts of the polyhydroxyl compound, but is not limited thereto.

As the foaming agent, water, methylene chloride and the like are used, but the foaming agent is not limited to these.

As the catalyst, a tertiary amine, a tertiary amine complex salt, an organic tin compound, etc. are used. For example, triethylenediamine, triethylenediamine complex salt, triethylamine, bisdimethylaminoethylether complex salt, bisdimethylamino. N-methylmorpholine of ethyl ether, stannous octylate, stannous dibutyl laurate and the like are preferable.

In addition, additives such as ultraviolet absorbers, antioxidants and pigments are used as necessary.

The amount of the foaming agent and the catalyst is not particularly limited, but generally, the amount of the foaming agent is 1 to 6 parts based on 100 parts of the polyhydroxyl compound, and the amount of the catalyst is 0.1 to 3 parts. It is preferably part.

The present invention is to obtain a flexible or semi-rigid polyurethane foam by mixing the above components to obtain a blend and foaming the blend according to a conventional method.

In this case, the carboxy-modified organosilicone reacts with an isocyanate to generate carbon dioxide gas as shown in the following formula, and gives a foam having a good appearance, low air permeability and water blocking effect.

~ NCO + HOOC ~ → ~ NHCOOCO
~ → ~ NHCO ~ + CO ₂ ~ NCO + H ₂ O → ~ NHCOOH → ~ NH ₂ + CO ₂ ~ NH ₂ + R'OOC → ~ NHCO ~ + R'OH ~ NCO + R'OH → ~ NHCOOR '(R' is a hydrogen atom or an alkyl group. Or indicates salt.)

In general, urethane forms bubbles by using carbon dioxide gas generated by the reaction of water and isocyanate as cell nuclei, and the density is determined by the foaming pressure. Carbon dioxide generated by the reaction between carboxy-modified silicone and isocyanate is generated. The gas further functions as a cell nucleus, which makes the cell finer than that of the conventional alkyl-cap type silicon and stably forms the cell. Moreover, the foam density can be reduced by the addition amount. In addition, the carboxy-modified silicone acts as a reaction delay catalyst.

It is considered that the carboxy-modified organosilicone acts as a retarding catalyst because it first forms a salt with an amine catalyst and then reacts with an isocyanate, as shown in the following formula.

[0032]

[Chemical 5]

In the present invention, the foaming conditions are appropriately selected, but the foaming time (rise time) is usually about 30 seconds to 3 minutes.

The reaction rate can be generally controlled with an amine catalyst, but the amine-tin catalyst has a strong activity and cannot be delicately controlled.

Further, by using the carboxy-modified silicone, for example, in the case of a molded product which is foamed in the mold, it is easy to spread the liquid in the mold after the raw material is discharged, and the void
It also has the effect of preventing cracks. In the foaming step of the soft block, the rise pattern can be changed by controlling the time from the start to the end of the reaction, which is effective for shape control and squareness.

[0036]

EFFECTS OF THE INVENTION According to the present invention, a flexible or semi-rigid polyurethane foam having a low air permeability and a water blocking effect can be obtained by using the above-mentioned polyolefin polyol and a specific silicone.

[0037]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

In the present invention, breathability means J
According to the Frazier type of IS L1004, the foam thickness was measured at 10 mm.

As for the water stopping property, as shown in FIGS. 1 and 2, a foam sample 1 having a thickness of 10 mm was punched out in a U shape (see FIG. 2) to obtain a 50% strength between two acrylic plates 2 and 2. It was sandwiched in a compressed state, water 3 was put into this U-shaped body at a predetermined height H, and the leakage time due to water pressure was measured to evaluate. In the figure, 4 is a spacer and 5 is a bolt.

Example 1 Hydrogenated terminal hydroxylated polyisoprene polyol (OH number 40) and dimer acid type polyester polyol (OH number 72) were blended at a weight ratio of 4: 1 and 100 parts of this was mixed with water. 2.0 parts, TDI80
30 parts, 0.3 part of triethylenediamine and 0.5 part of stannas octoate as a catalyst, and 1 part of a carboxy-modified organosilicone represented by the following formula as a foam stabilizer are foamed to obtain a flexible polyurethane foam. Obtained. The physical properties are shown in Table 1.

[0041]

[Chemical 6] (R is C ₃ H ₆ (C ₂ H ₄ O) _a (C ₃ H ₆ O) _b C ₃ H ₆ COO
H and a / b are in a molar ratio of 50/50, x is 150 and y is 15
Are shown respectively. )

[Comparative Examples 1 to 3] Addition polymerization of propylene oxide to glycerin, molecular weight 3000 (OH value 5
6) 100 parts of polyether polyol, 42.8 parts of TDI80, 3.0 parts of water, 0.9 part of tolylenediamine as a catalyst and 0.11 part of stannas octoate, the same as Example 1 as a foam stabilizer. Using 1 part of the carboxy-modified organosilicone, a flexible polyurethane foam was obtained in the same manner as in Example 1 (Comparative Example 1).

Flexible polyurethane foams were obtained in the same manner as in Comparative Example 1 except that the terminal alkyl cap type silicone and the terminal hydroxyl group type silicone were used as the foam stabilizer (Comparative Examples 2 and 3). The physical properties are also shown in Table 1.

[0044]

[Table 1]

* (1) Above block height of 500 m / m
The lower breathability range is shown. * (2) The hydroxyl-type silicone used in Comparative Example 3 was difficult to commercialize because voids were generated in the foam as the density became lower. It is presumed that this is because the lower the density, the more water and isocyanate, and the terminal hydroxyl groups react immediately with the isocyanate to lower the foam stabilizing ability.

[Example 2, Comparative Example 4] In the formulation of Example 1, foaming was performed by changing the amount of silicone, and as shown in FIG. 3, the creamy time (foaming time) and the foaming time (foaming time) during foaming Rise time) was measured. The results are shown in Table 2. In addition, as a comparative example, the same measurement was performed in the same composition as in Example 2 except that a terminal alkyl cap type silicone was used. The results are also shown in Table 2.

Here, in FIG. 3, 6 is a mixing head, 7 is a discharge nozzle, A is an example and B is a comparative example.

[0048]

[Table 2]

As can be seen from Table 2 and FIG. 3, the two types of silicones used as comparative examples tend to show a slightly faster reaction when the amounts thereof are increased, but they are not so remarkable as in the present invention. However, in the case of carboxy-modified silicone, the reaction is obviously slow. Therefore, in the conventional method (comparative example), when foaming is rapidly performed in the production line, when the foaming is rapidly performed, a crack is generated due to clogging of the reaction zone. Further, when the side is pulled up with a film to make it square, handling is very difficult. However, in the case of the present invention, it is recognized that the gradual operability is improved because the reaction becomes gradual.

[Brief description of drawings]

FIG. 1 is a view showing an apparatus for a water stop test.

FIG. 2 is a diagram showing a foam sample.

FIG. 3 is a diagram showing a foamed state of the present invention.

[Explanation of symbols]

 1 Foam Sample 2 Acrylic Plate 3 Spacer 4 Bolt 5 Water 6 Mixing Head 7 Discharge Nozzle A Example B Comparative Example

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area // (C08G 18/06 101: 00) C08L 75:04

Claims (2)

[Claims] 1. A method of making a flexible or semi-rigid polyurethane foam from a formulation containing a polyhydroxyl compound, an isocyanate, a blowing agent, a catalyst and a foam stabilizer, said method comprising:
A method for producing a water-proof polyurethane foam, which comprises using a polyolefin polyol as a polyhydroxyl compound and a carboxy-modified organosilicone as a foam stabilizer. 2. A polyhydroxyl compound 100 as a foam stabilizer.
The method for producing a waterproof polyurethane foam according to claim 1, wherein 0.3 to 5 parts by weight is used with respect to parts by weight.