JPH11116656A - Production of polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyurethane foam excellent in compression strength and dimensional stability, and especially effectively used in the uses such as a heat insulator, a building material and a structural material without using a fluorocarbon or an alternative fluorocarbon. SOLUTION: This method for producing a polyurethane foam by carrying out the reaction and foaming of a polyol with a polyisocyanate and water comprises formulating at least (a) 10-80 pts.wt. polyether polyol obtained by the addition of an alkylene oxide by using an alkylenediamine as an initiator, and having 100-800 mgKOH/g hydroxyl value, (b) 5-80 pts.wt. polyether polyol having two functional groups and >=100 mgKOH/g hydroxyl value, and (c) 5-80 pts.wt. polyether polyol having >=2 functional groups and <80 mgKOH/g hydroxyl value, with 100 pts.wt. polyol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyurethane foam, and more particularly, does not use a specific chlorofluorocarbon such as trichlorofluoromethane or an alternative fluorocarbon.
The present invention relates to a method for producing a polyurethane foam.

[0002]

2. Description of the Related Art Polyurethane foams are widely used for heat insulating materials, building materials, structural materials, etc. because of their excellent heat insulating performance, lightweight structural properties and the like. . Heretofore, as a method for producing this polyurethane foam, a method has been used in which a polyol and a polyisocyanate are foamed by adding a foaming agent such as specific CFC-11 and CFC-12. According to this method, a specific fluorocarbon used as a foaming agent is sealed in a closed cell structure, so that a material having high heat insulating performance can be obtained.

However, in recent years, there has been a risk that these chlorofluorocarbon gases may destroy the earth's ozone layer, and the Montreal Protocol has been adopted to pursue the elimination of specific chlorofluorocarbons (CFCs) by the end of this century. For this reason, attention has been paid to a method of foaming using carbon dioxide gas generated by the reaction of water and isocyanate using water as a foaming agent instead of all or some of these specific fluorocarbons as a foaming agent for a polyurethane foam. .

[0004] However, in the method of producing water only as a foaming agent without using any specific fluorocarbon, the reaction heat due to the chemical reaction between water and isocyanate cannot be sufficiently cooled, so that cracks, scorch and the like are easily generated. There were drawbacks. In addition, since carbon dioxide gas easily permeates the cell membrane, there is a problem in dimensional stability such that the foam shrinks due to a change with time, particularly at high temperatures, and particularly low density products (2
(3 kg / m ³ or less) has a particularly large tendency. Further, the reaction between water and isocyanate increases the urea bond, increases the flyability (brittleness) of the foam, and impairs the adhesion to the face material such as panels and boards. In addition, due to the thickening of the polyol component itself, machine moldability,
Mixing and foam flow are significantly reduced.

[0005] In order to solve these problems, it has been proposed to use a mixture of various polyols having different numbers of functional groups. For example, Japanese Patent Application Laid-Open No. 6-25375 discloses specific polyol compounds as specific polyol compounds. A method for producing an open-celled rigid polyurethane foam using water, which is a mixture of three kinds of polyols having a functional group number and a hydroxyl value, as a foaming agent is described. JP-A-7-10952 discloses an organic polyamine. A process for producing an open-celled rigid polyurethane foam using water as a foaming agent, which is a mixture of three polyols each having a specific number of functional groups and a hydroxyl value, each containing a polyoxyalkylene polyol as an initiator, is described. JP-A-7-109
No. 53 describes a method for producing an open-celled rigid polyurethane foam using water, which is a mixture of three polyols each having a specific number of functional groups and a hydroxyl value, as a foaming agent. No satisfactory performance has yet been obtained.

Accordingly, an object of the present invention is to produce a polyurethane foam which is excellent in compressive strength and dimensional stability without using chlorofluorocarbon or a substitute chlorofluorocarbon and which can be effectively utilized particularly in applications such as heat insulating materials, building materials and structural materials. It is to provide a way to do it.

[0007]

As a result of various studies, the present inventors have found that a specific polyether polyol compound is used in combination as a polyol component in a method for producing a polyurethane foam using only water as a foaming agent. It has been found that the above can achieve the above object.

The present invention has been made on the basis of the above findings. In a method for producing a polyurethane foam in which a polyol, a polyisocyanate and water are reacted and foamed, an alkylene diamine as an initiator (a) is added to 100 parts by weight of the polyol. Used, 10 to 80 parts by weight of a polyether polyol having a hydroxyl value of 100 to 800 mgKOH / g obtained by adding an alkylene oxide, (b) 5 to 80 parts by weight of a polyether polyol having a functional group number of 2 and a hydroxyl value of 100 mgKOH / g or more; (C) Functional group number 2
As described above, the present invention provides a method for producing a polyurethane foam, which comprises at least 5 to 80 parts by weight of a polyether polyol having a hydroxyl value of less than 80 mgKOH / g.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for producing a polyurethane foam of the present invention will be described in detail.

The polyether polyol (a) used in the present invention is a polyether polyol having a hydroxyl value of 100 to 800 mgKOH / g obtained by using an alkylene diamine as an initiator and adding an alkylene oxide. Examples of the alkylene diamine used herein include, for example, ethylene diamine, propylene diamine, butylene diamine, hexylene diamine, octylene diamine, and decylene diamine.Examples of the alkylene oxide include ethylene oxide and propylene oxide. Butylene oxide and the like.

Among the polyether polyols of the above-mentioned component (a), they are obtained by using ethylenediamine as an initiator and adding ethylene oxide and / or propylene oxide, and have a hydroxyl value of 200 to 600 mm.
A polyether polyol that is KOHg is preferable because a material having excellent properties such as strength can be obtained.

The amount of the polyether polyol (a) used is 10 to 80 parts by weight, preferably 25 to 80 parts by weight, more preferably 40 to 70 parts by weight, per 100 parts by weight of the polyol (all polyol components). It is. 10-8
If the amount is outside the range of 0 parts by weight, good open-celled urethane foam cannot be obtained.

The polyether polyol having a functional group number of 2 and a hydroxyl value of not less than 100 mgKOH / g of the component (b) used in the present invention includes ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3 -Propylene glycol, 1,
Low molecular weight polyols such as 2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, hexamethylene glycol, and (hydrogenated) bisphenol A ethylene oxide and / or propylene oxide adducts; Polyethylene obtained by using ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, water, hydroquinone, resorcinol, hydrogenated bisphenol A, bisphenol A, bisphenol F, etc., and adding an alkylene oxide such as ethylene oxide or propylene oxide thereto. Ether polyols and the like.

Among the polyether polyols of the above-mentioned component (b), bisphenol compounds represented by the following general formula (I) of the following [Chemical formula 2] (the same as the above [Chemical formula 1]) may be added to ethylene oxide and / or propylene. Polyether polyol obtained by adding an oxide, especially,
It is particularly preferable to use the polyether polyol having a hydroxyl value of 100 to 200 mgKOH / g, since a more excellent open-cell polyurethane foam can be obtained.

[0015]

Embedded image

The amount of the polyether polyol (b) used is 5 to 8 per 100 parts by weight of the total polyol component.
0 parts by weight, preferably 5 to 60 parts by weight, more preferably 8 to 40 parts by weight. If the amount is outside the range of 5 to 80 parts by weight, good open-celled urethane foam cannot be obtained.

The polyether polyol having a functional group number of 2 or more and a hydroxyl value of less than 80 mgKOH / g of the component (c) used in the present invention includes, for example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol as an initiator. Water, hydroquinone, resorcinol, hydrogenated bisphenol A, bisphenol A, bisphenol F, glycerin, trimethylolpropane, 1,2,6-hexanetriol, triethanolamine, pentaerythritol, ethylenediamine, tolylenediamine, diphenylmethanediamine, tetramethylol Cyclohexane, methyl glucoside,
Using 2,2,6,6-tetrakis (hydroxymethyl) cyclohexanol, diethylenetriamine, sorbitol, mannitol, dulcitol, sucrose, monoethanolamine, diethanolamine, etc., and adding an alkylene oxide such as ethylene oxide, propylene oxide, etc. And the resulting high molecular polyether polyols.

Among the polyether polyols of the component (c), polyether polyols obtained by adding ethylene oxide and / or propylene oxide to the bisphenol compound represented by the above general formula (I), especially hydroxyl groups The value is 30-70 mmKOH /
The use of the polyether polyol having a range of g is particularly preferable because a more excellent open-celled polyurethane foam can be obtained.

The amount of the polyether polyol (c) used is 5 to 8 per 100 parts by weight of the total polyol component.
0 parts by weight, preferably 5 to 60 parts by weight, more preferably 8 to 40 parts by weight. If the amount is outside the range of 5 to 80 parts by weight, good open-celled urethane foam cannot be obtained.

Further, as the polyol used in the present invention, other polyols can be used in combination with the essential polyether polyol described above. As the other polyol, for example, as an acid component, for example, succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid,
Isophthalic acid, terephthalic acid, tetrahydrophthalic acid,
As a polybasic acid or carbonic acid such as endomethylenetetrahydrophthalic acid, hexahydrophthalic acid or the like and a polyhydric alcohol component, glycerin, trimethylolpropane,
Trimethylolethane, pentaerythritol, etc., glycol products such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, pentanediol, cyclohexane dimethanol, etc. Polyester polyols, polycarbonate polyols, and polycaprolactone. The other polyol is used in an amount of preferably not more than 50 parts by weight, more preferably not more than 20 parts by weight, based on 100 parts by weight of all the polyol components.

The average hydroxyl value of the polyol (all polyol components) used in the present invention is 150 to 650 (mgK
OH / g), particularly preferably from 200 to 500. If the average hydroxyl value is less than 150, the dimensional stability is unfavorably reduced, and if it is more than 650, flyability is liable to occur, which is not preferred.

The polyisocyanate used for producing the polyurethane foam by the production method of the present invention includes aliphatic, alicyclic and aromatic polyisocyanates. Isocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4′-diphenylmethane diisocyanate (4,4′-MDI), 2,
4'-diphenylmethane diisocyanate (2,4'-
MDI), 2,2′-diphenylmethane diisocyanate (2,2′-MDI), polyphenylenepolymethylene polyisocyanate (polymeric MDI), 1,6-
Hexamethylene diisocyanate (HDI), 2,2
4-trimethylhexamethylene diisocyanate (TM
DI), p-phenylene diisocyanate (PPD)
I), 4,4'-dicyclohexylmethane diisocyanate (HMDI), 3,3'-dimethyldiphenyl-
4,4'-diisocyanate (TODI), dianisidine diisocyanate (DADI), m-xylene diisocyanate (XDI), tetramethylxylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), 1,5-naphthalene diisocyanate (NDI) , Trans-1,4-cyclohexyl diisocyanate (CHDI), lysine diisocyanate (L
DI), or a urethane-modified product, an allophanate-modified product, a biuret-modified product or a mixture thereof.

When the above polyurethane foam is produced by the production method of the present invention, the isocyanate group / hydroxyl group is preferably in the range of 0.8 to 1.5 (equivalent ratio, NCO index), particularly 0.9 to 1.2. It is preferable to carry out reaction foaming.

When the above polyurethane foam is produced by the production method of the present invention, water is used as a blowing agent,
The amount of water used depends on the amount of the polyol (all polyol components) 1
The amount is preferably 5 to 15 parts by weight, more preferably 7 to 12 parts by weight, based on 00 parts by weight. By using water in this range, the foam density becomes 17-25 kg / m.
³ is preferred because a polyurethane foam of ³ is obtained.

In the production of the polyurethane foam according to the production method of the present invention, an amine compound can be added as a catalyst.
N, N-dimethylcyclohexylamine, N, N-dicyclohexylmethylamine, N, N-dimethylbenzylamine, N, N-dimethylcetylamine, triethylamine, N, N-dimethyldodecylamine, pyridine, N
-Methylmorpholine, N-ethylmorpholine, N, N,
N'N'-tetramethylethylenediamine, N, N,
N′N′-tetramethyl-1,3-propanediamine,
N, N, N'N'-tetramethyl-1,3-butanediamine, N, N, N'N'-tetramethyl-hexanediamine, methylenebis (dimethylcyclohexylamine), 3-dimethylamino-N, N- Dimethylpropionamide, N, N, N ', N'-tetraethylmethylenediamine, bis-2-dimethylaminoethylether, 2- (N, N-dimethylamino) ethyl-3-
(N, N-dimethylamino) propyl ether, 4,
4′-oxydiethylene dimorpholine, ethylene glycol bis (3-dimethylaminopropyl) ether,
N, N, N ', N', N "-pentamethyldiethylenetriamine, N, N, N ', N', N" -pentamethyldipropylenetriamine, N, N, N ', N'-tetra (3- Dimethylaminopropyl) methanediamine, triethylenediamine, N, N'-dimethylpiperazine,
N, N'-diethylpiperazine, N-methyl-N'-dimethylaminoethylpiperazine, N- (2-dimethylaminoethyl) morpholine, 1,2-dimethylimidazole, 1,8-diazabicyclo (5,4,0) Undecene-7 (DBU), DBU phenolate, DBU carboxylate, DBU octylate, N, N'-dimethylaminoethanol, ethoxylated hydroxyamine, N, N
-Tetramethyl-1,3-diamino-2-propanol, N, N, N'-trimethylaminoethylethanolamine, N, N, N'-trimethylaminopropylethanolamine, N-methyl-N '-(2- (Hydroxyethyl) piperazine, N- (2-hydroxyethyl) morpholine, 1- (2-hydroxypropyl) imidazole, 2,4,6-tris (dimethylaminomethyl) phenol, 1,4-bis (2-hydroxypropyl) -2
-Methylpiperazine, triethanolamine, 3,3-
Diamino-N-methyldipropylamine, bis (dimethylaminopropyl) amine, morpholine, and the like can be used.

Further, when a polyurethane foam is produced by the production method of the present invention, for example, dibutyltin dilaurate, dibutyltin diacetate, diethyltin diacetate, dihexyltin diacetate, Organic tin compounds such as di-2-ethylhexyltin oxide, dioctyltin dioxide, stannous octoate, stannous oleate, and metal compounds such as potassium acetate, sodium bicarbonate, and calcium carbonate can be used.

The polyurethane foam produced by the production method of the present invention has open cells. When a conventional polyurethane foam using water as a foaming agent has closed cells, it can be formed by the reaction between water and isocyanate. Various disadvantages due to the fact that carbon dioxide gas easily permeates the cell membrane are improved.

Further, by mixing a viscosity reducing agent (plasticizer) with the polyol (all polyol components) used in the present invention, the flowability of the foaming stock solution can be improved. Examples of the viscosity reducing agent include polyethylene glycol monomethyl ether, propylene glycol monoethyl ether, polyethylene glycol monomethyl ether acetate, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate and the like.

When a polyurethane foam is produced by the production method of the present invention, calcium carbonate, barium sulfate,
Silica, clay, talc, wollastonite, glass fibers can be used.

Further, when producing a polyurethane foam by the production method of the present invention, tris (2,3-dichloropropyl) phosphate, tris (2-chloropropyl) phosphate, tris (2-chloroethyl) phosphate, 2,2 -Bis (chloroethyl) propylenebis (2-chloroethyl) phosphate, tetrakis (2-
Chloroethyl) ethylene diphosphate, tetrakis (2-chloroethyl) -2,2-bis (chloromethyl)
-Propylene diphosphate, chlorinated organic polyphosphate, dimethylmethylphosphonate, chlorinated paraffin, chlorinated polyethylene, polyphosphite, brominated phosphite compound, dibromopropanol, dibromoneopentyl glycol, tetrabromobisphenol A, polyoxyethyltetra Bromobisphenol A,
Ammonium sulfate, ammonium polyphosphate, diammonium phosphate, antimony oxide, aluminum hydroxide, calcium carbonate, melamine, o, o-diethyl-
Flame retardants such as N, N-bis (2-hydroxyethyl) aminomethylphosphonate, tris (polyoxyalkylene) phosphonate, tris (polyoxyalkylene) phosphite ester and tris (chlorinated polyol) phosphonate can be used. .

When a polyurethane foam is produced by the production method of the present invention, an antioxidant, an ultraviolet absorber, a flame retardant, a coloring agent, a filler, a wax, a preservative, a silicone-based surfactant may be used according to the purpose. Conventional additives such as a foam stabilizer such as an agent, a plasticizer, a solvent, a film forming aid, a dispersant, and a fragrance can also be used.

The above-mentioned polyurethane foam according to the present invention can be produced by a one-shot method, a quasi-prepolymer method, a prepolymer method, a spray method and other various well-known methods, and is particularly preferably produced by a one-shot method.

The polyurethane foam according to the present invention thus obtained can be used for various uses such as a heat insulating material, a building material and a structural material.

[0034]

EXAMPLES The present invention will be described in more detail with reference to Production Examples and Examples, but the present invention is not limited by the following Examples.

Example 1 The amounts of polyol and polyphenylpolymethylpolyisocyanate (polymeric MDI) were adjusted to 400 parts by weight based on the composition ratios shown in Tables 1 and 2 below.
After stirring at 0 rpm for about 5 seconds (the liquid obtained at this time is hereinafter referred to as a urethane stock solution), a predetermined amount is 20 × 20 × 20.
The foam was poured into an upper open box of 3 cm, allowed to stand for 3 days, cut out of a foamed foam, and measured for foam density and dimensional stability according to JIS A9514.
The closed cell rate was measured in accordance with D2856, and JIS K7
The compressive strength was measured according to 220, and the surface hardness was measured using an Asker C surface hardness tester.

Further, in order to evaluate the adhesiveness, a sandwich panel with a 20 mm thick steel plate face material was prepared using a predetermined amount of a urethane stock solution and zinc steel plates of 35 × 30 cm above and below, and a foam was cut out and subjected to JIS. K6851
A T-type peeling test was performed according to the test.

Further, in order to evaluate the fluidity, 2 × 4
A predetermined amount of a urethane stock solution is poured into an open aluminum mold at 0 × 40 cm, a lid is formed, molded, the spread of the foam after demolding is determined by area, and converted to an area per unit g for evaluation. did. Here, the larger the numerical value, the better the fluidity.

The results are shown in the following [Table 1] and [Table 2].

[0039]

[Table 1]

[0040]

[Table 2]

The details of the components and the like in the above [Table 1] and [Table 2] are as follows. In the table, parts by weight "→"
Means the same as the left. EDA-PO / EO: Propylene oxide / ethylene oxide mixed adduct of ethylenediamine (OHV = 39
0) PDA-PO / EO: Propylene oxide / ethylene oxide mixed adduct of ethylenediamine (OHV = 39
0) BDA-PO / EO: Propylene oxide / ethylene oxide mixed adduct of ethylenediamine (OHV = 39
0) SC-PO / EO: Propylene oxide / ethylene oxide mixed adduct of sucrose (OHV = 400) BA-PO-1: Propylene oxide adduct of bisphenol A (OHV = 56) BF-PO-1: Bisphenol A Propylene oxide adduct (OHV = 56) PG-PO-1: Propylene oxide adduct of propylene glycol (OHV = 50) BA-PO-2: Propylene oxide adduct of bisphenol A (OHV = 112) PG-PO-2 : Propylene oxide adduct of propylene glycol (OHV = 140) PPG: polypropylene glycol (OH
V = 300) Me-EO: ethylene glycol monomethyl ether (OHV = 131) #: NCO index = 1.05

As is apparent from the examples, among the polyether polyols of the components (a), (b) and (c) used in the present invention as the polyol component, the polyether polyol of the component (a) is sucrose. When used in place of the polyether polyol (Comparative Example No. 3),
Alternatively, when the polyether polyol of the component (c) is not used (Comparative Example No. 2), no open cells can be obtained,
When the polyether polyol of the component (b) is not used (Comparative Example No. 1), there are disadvantages such as a decrease in surface hardness and dimensional stability.

On the other hand, the above components (a), (b) and (c) used as the polyol component in the present invention
By using various kinds of polyether polyols in combination, the foam density is high, the dimensional stability is good,
Polyurethane foams having excellent adhesiveness and fluidity were obtained (Examples Nos. 1 to 11).

[0044]

According to the production method of the present invention, a polyurethane which is excellent in compressive strength and dimensional stability without using chlorofluorocarbon or a substitute chlorofluorocarbon, and which can be effectively utilized particularly in heat insulating materials, building materials, structural materials and the like. Forms can be manufactured.

Claims (3)

[Claims] 1. A method for producing a polyurethane foam in which a polyol, a polyisocyanate and water are reacted and foamed, wherein a hydroxyl group obtained by adding (a) an alkylene diamine as an initiator and adding an alkylene oxide to 100 parts by weight of the polyol. Value 100-800mgKOH / g
10 to 80 parts by weight of a polyether polyol, (b) 5 to 80 parts by weight of a polyether polyol having a functional group of 2 and a hydroxyl value of 100 mgKOH / g or more and (c) a polyether having a functional group of 2 or more and a hydroxyl value of less than 80 mgKOH / g A method for producing a polyurethane foam, comprising at least 5 to 80 parts by weight of a polyol. 2. A polyether obtained by adding ethylene oxide and / or propylene oxide to a bisphenol compound represented by the following general formula (I): The method for producing a polyurethane foam according to claim 1, wherein the polyurethane foam is a polyol. Embedded image 3. The polyether polyol as the component (c) is a polyether polyol obtained by adding ethylene oxide and / or propylene oxide to the bisphenol compound represented by the general formula (I). The method for producing a polyurethane foam according to claim 1 or 2, wherein: