JPH07206966A - Method for producing rigid polyurethane foam - Google Patents

Abstract

PURPOSE:To obtain a rigid polyurethane foam excellent in liquid flowability and resin strength and useful for heat-insulating materials, etc., by reacting a polyol with a polyfsocyanate in the presence of a foaming agent comprising a hydrogen atomcontaining halogenated hydrocarbon, etc. CONSTITUTION:(A) A polyol component is reacted with (B) a polyisocyanate such as tolylene diisocyanate in the presence of (C) a foaming agent comprising a hydrogen atom-containing halogenated hydrocarbon and/or water to obtain the objective polyurethane foam. The polyol component contains as essential components (i) a polyol produced by addition-reacting 1-10 moles of propylene to a bisphenol compound preferably in an amount of 8-28wt.% (based on the component A), (ii) the alkylene oxide adduct of an ethylenediamine compound preferably in an amount of 24-56wt.%, and (iii) the alkylene oxide adduct of an ethylenediamine compound preferably in an amount of 2-16wt.%, and has an average functional group number of 3-5 and a hydroxyl group value of 300-550.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing rigid urethane foam. More specifically, it relates to a method for producing a rigid urethane foam having excellent liquid flowability.

[0002]

2. Description of the Related Art Rigid urethane foam uses trichloromonofluoromethane (CFC-11) as a foaming agent, and therefore has excellent dimensional stability and heat insulating properties, and is widely used as a heat insulating material for refrigerators, freezers, buildings, etc. It is used.
However, in recent years, in order to protect the earth's ozone layer, regulations such as halogenated hydrocarbon blowing agents containing no hydrogen atom have been started. CFC-11 is included in this regulation target, and the foaming agent of rigid urethane foam is shifting to hydrogen element-containing halogenated hydrocarbon or water having a small ozone depletion potential. However, since these newly used foaming agents have hydrogen atoms in the molecule, they have a higher solubility and swelling in the generated urethane resin component than the current CFC-11. Therefore, the resulting urethane resin has a problem in that the foaming agent is unlikely to turn into a gas during curing, resulting in poor liquid flowability.

As a method for improving liquid flowability when CFC-11 is used as a foaming agent, 2,4-diaminotoluene and / or 2,6 diaminotoluene, 2,3 diaminotoluene and / or polyether polyol are used. A method using a polyol obtained by addition-polymerizing alkylene oxide to 3,4 diaminotoluene and a compound having 2 to 4 active hydrogens (for example, Japanese Patent Publication No. 4-5
Japanese Patent No. 4688) has been proposed.

[0004]

However, the above method is not sufficiently effective in improving the liquid flow property when the above-mentioned blowing agent having a small ozone depletion potential (hydrogen atom-containing halogenated hydrocarbon or water) is used. . The purpose of the present invention is to
When producing rigid polyurethane foams using hydrogen atom-containing halogenated hydrocarbons and water as blowing agents, conventional C
It is to provide a method for producing a rigid polyurethane foam having the same resin strength and liquid flowability as when FC-11 is used.

[0005]

The present inventors have proposed a method for producing a rigid polyurethane foam having a high resin strength and excellent liquid flowability by using a hydrogen atom-containing halogenated hydrocarbon or water as a foaming agent. As a result of intensive studies, the inventors have found that the above problems can be solved by using a polyol having a specific structure as a raw material for a rigid polyurethane foam, and have reached the present invention.

That is, according to the present invention, a rigid polyurethane foam is produced by reacting a polyol (A) and a polyisocyanate (B) in the presence of a blowing agent (C) comprising a hydrogen atom-containing halogenated hydrocarbon and / or water. In the method, as the polyol (A), a propylene oxide adduct of bisphenol, an alkylene oxide adduct of toluenediamine, and an alkylene oxide adduct of ethylenediamine are contained as essential components, and the average number of functional groups is 3 to 5 and a hydroxyl group. A method for producing a rigid urethane foam, characterized in that a polyol having a value of 300 to 550 is used.

Specific examples of bisphenols constituting the propylene oxide adduct (a1) of bisfluenol contained in the polyol (A) used in the present invention include, for example, bisphenol A, bisphenol F, bisphenol S, 4, 4'-dihydroxybiphenyl and 2,2'-bis (4-hydroxyphenyl) hexafluoropropane. Of these, preferred are bisphenol A and bisphenol F. The number of moles of propylene oxide added to these bisphenols is usually 1 to 12 moles, preferably 1 to 10 moles.

Specific examples of toluenediamine constituting the alkylene oxide adduct (a2) of toluenediamine contained in the polyol (A) used in the present invention include, for example, 2,4-toluenediamine and 2,6-toluenediamine. , 2,3-toluenediamine and 3,4-
Examples include toluene diamine. Among these, preferred are 2,4-toluenediamine, 2,6-toluenediamine and mixtures thereof. Examples of alkylene oxides to be added to these toluenediamines include ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), butylene oxide, and a combination of two or more thereof (block and / or random addition). . Of these, preferred is P
O, EO and combinations of these. The addition mole number of the alkylene oxide is usually 1 to 20 moles, preferably 2 to 11 moles.

Specific examples of the ethylenediamines constituting the alkylene oxide adduct (a3) of ethylenediamines contained in the polyol (A) used in the present invention include ethylenediamine, diethylenetriamine, pentamethylenehexamine and the like. Among these, ethylenediamine is preferable. Examples of the alkylene oxide to be added to these ethylenediamines include EO, PO, butylene oxide, and a combination of two or more thereof (block and / or random addition). Of these, the preferred one is P
O, EO and combinations of these. The number of moles of the alkylene oxide added is usually 1 to 15 moles, preferably 2 to 10 moles.

The polyol (A) in the present invention contains the above-mentioned (a1), (a2) and (a3) as essential components. The amount of (a1) is usually based on the weight of (A). It is 8 to 28% by weight, preferably 10 to 20% by weight. If the amount of (a1) is less than 8% by weight, the liquid flowability will be insufficient, and if it exceeds 28% by weight, the strength of the foam will decrease and the foam will easily contract. The amount of (a2) is usually 24-56% by weight, preferably 35, based on the weight of (A).
~ 50% by weight. When the amount of (a2) is less than 24% by weight, the strength of the foam is lowered and the foam easily shrinks, and when it exceeds 54% by weight, liquid flowability is deteriorated. The amount of (a3) is
It is usually 2 to 16% by weight, preferably 5 to 12% by weight, based on the weight of (A). When the amount of (a3) is less than 2% by weight, the liquid flowability becomes insufficient, and when it exceeds 16% by weight, the strength of the foam decreases.

(A) is (a1), (a2) and (a)
A known polyol (a4) used together with 3) in an ordinary rigid polyurethane foam as required (for example, a polyhydric alcohol or an alkylene oxide adduct thereof, a polyester polyol, a polybutadiene polyol, an acrylic polyol, an ethylenically unsaturated monomer). Polymer polyols modified with body polymers). Specific examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, glycerin, trimethylolpropane, pentaerythritol,
Examples include methyl glycolide, diglycerin, sorbitol, sucrose and the like.

The average number of functional groups of (A) is usually 3 to 5, preferably 3.3 to 4.7, and the hydroxyl value is usually 300.
˜550, preferably 330 to 520. If the average number of functional groups is less than 3, the strength of the foam is reduced and the foam tends to shrink, and if it exceeds 5, liquid flowability deteriorates. Further, when the hydroxyl value is less than 300, the foam strength is lowered and the foam tends to shrink, and when it exceeds 550, the liquid flowability is deteriorated.

As the polyisocyanate (B) used in the present invention, those conventionally used for rigid polyurethane foams can be used. Examples of such isocyanates include aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, and modified products thereof (for example, carbodiimide-modified, allophanate-modified, urea-modified, burette-modified, isosinurate-modified, oxazolidone-modified). , Isocyanate group-terminated prepolymers and mixtures of two or more thereof.

Specific examples of aromatic polyisocyanates include 1,3- and 1,4-phenylene diisocyanate, 2,4- and 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4′- and 4,4 '
-Diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (crude MDI),
Examples thereof include naphthylene-1,5-diisocyanate, triphenylmethane-4,4 ′, 4 ″ -triisocyanate, xylylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate.
Specific examples of the aliphatic isocyanate include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate and xylylene diisocyanate. Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate and 1,4-cyclohexane diisocyanate. Specific examples of the modified polyisocyanate include carbodiimide modified MDI, sucrose modified TDI, and castor oil modified MDI.
Preferred of these are MDI, crude MDI,
Sucrose modified TDI and carbodiimide modified MDI.

The ratio of the polyol (A) to the polyisocyanate (B) can be variously changed, but the equivalent ratio of the hydroxyl group of the polyol (A) and the isocyanate group of the polyisocyanate (B) is usually 1.0: (0 .5-
1.5), preferably 1.0: (0.9 to 1.2).

Specific examples of the hydrogen atom-containing halogenated hydrocarbon blowing agent used as the blowing agent (C) in the present invention include those of HCFC type (for example, HCFC-12).
3, HCFC-141b, HCFC-22, HCFC-
142b); HFC type (eg HFC-13
4a, HFC-152a, HFC-356) and the like. Among these, preferable one is HCFC-14
1b, HFC-134a, HFC-356 and mixtures of two or more thereof. If necessary, water or a low boiling point hydrocarbon may be used in combination with these hydrogen atom-containing halogenated hydrocarbon blowing agents. Further, water can be used alone without using a halogenated hydrocarbon blowing agent or a low boiling point hydrocarbon. Low boiling hydrocarbons usually have a boiling point of 0 to
It is a hydrocarbon at 50 ° C., and specific examples thereof include propane, butane, pentane and a mixture thereof. The amount of the hydrogen atom-containing halogenated hydrocarbon-based blowing agent used in the method of the present invention is usually 0 to 50 parts by weight, preferably 0 to 45 parts by weight, per 100 parts by weight of the polyol component. The amount of water used is usually 0 to 10 parts by weight, preferably 0.5 to 8 parts by weight, per 100 parts by weight of polyol. The amount of low boiling point hydrocarbons used is Polyol 1
It is usually 0 to 40 parts by weight, preferably 0, per 100 parts by weight.
~ 30 parts by weight.

In the present invention, if necessary, a catalyst usually used for polyurethane reaction, for example, an amine-based catalyst (triethylenediamine, N-ethylmonophorine, diethylethanolamine, 1,8 diazabicyclo (5.4.
0) undecene 7 and the like) and metal catalysts (stannous octylate, stannic dibutyl dilaurate, lead octylate, etc.) can be used. The amount of catalyst used is (A)
It is usually 0.001 to 5% by weight with respect to the weight of.

Further, if necessary, a foam stabilizer and a coloring agent (dye,
Known additives such as pigments), plasticizers, fillers, flame retardants, antioxidants and antioxidants can also be used.

An example of the method for producing a rigid polyurethane foam is shown below. First, a predetermined amount of a polyol component, a foaming agent, a foam stabilizer, a catalyst and other additives are mixed. A polyurethane foamer or stirrer is then used to rapidly mix the mixture with the polyisocyanate component. The obtained mixed liquid is poured into a mold. After curing, the mold is removed to obtain a rigid polyurethane foam.

The rigid polyurethane foam obtained by the method of the present invention has high strength and good heat insulating property, and particularly has excellent liquid flowability, and therefore can be widely used as a heat insulating material for refrigerators, freezers, constructions and the like.

[0021]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. "Parts" in the examples indicate parts by weight.

Example 1 8 parts of a polyol (a1-1) having a hydroxyl value of 392 in which PO (1 mol) was added to bisphenol A (1 mol), and a hydroxyl group in which PO (4 mol) was added to toluenediamine (1 mol) 32 parts of a polyol (a2-1) having a valency of 633, and a polyol having a hydroxyl value of 450 (a3−) obtained by adding EO (1 mol) and PO (1 mol) to ethylenediamine (1 mol).
1) 5 parts and 55 parts of polyol (a4) having a hydroxyl value of 450 obtained by adding PO to a mixture of glycerin (1 mol) and sugar (1 mol) (average number of functional groups of all polyols: 4.6)
7, hydroxyl value 504), "Silicone SH-193"
(Tore Silicone Co., foam stabilizer) 1.5 parts, water 2 parts,
"Phiroll CEF" (manufactured by Akzo Japan, flame retardant) 10 parts, "U-CAT1000" (manufactured by San-Apro, amine catalyst) 0.8 parts and "HCFC-141"
b ”29.1 parts were pre-blended and temperature-controlled at 25 ° C., and therein,“ Millionate MR-10 ”was temperature-controlled at 25 ° C.
0 "(manufactured by Nippon Polyurethane Co., Ltd., crude MDI) and added 177 parts, and homodisper (stirrer made by special machine) 3000 rp
After stirring for 10 seconds at m, the temperature was adjusted to 25 ° C, 1000 mm
(Length) x 100 mm (width) x 50 (height) mm, the end opposite to the open mouth of the mold whose vertical direction is an open system to the floor surface is injected, and after 10 minutes demolding, hard urethane foam Got

Example 2 16 parts of polyol (a1-2) having a hydroxyl value of 162 in which PO (8 mol) was added to bisphenol A (1 mol), and hydroxyl group in which PO (6 mol) was added to toluenediamine (1 mol) 24 parts of polyol (a2-2) having a valence of 477, 8 parts of polyol (a3-1) and 52 of polyol (a4)
Parts (average number of functional groups of all polyols: 4.46, hydroxyl value: 4
10), 1.5 parts of "Silicone SH-193", water 2
Part, "Phiroll CEF" 10 parts, "U-CAT10
00 "0.7 part and" HCFC-141b "26.7
Parts are pre-blended and the temperature is adjusted to 25 ° C.
Then, 153 parts of "Millionate MR-100" whose temperature was adjusted was added and the same operation as in Example 1 was carried out to obtain a rigid urethane foam.

Example 3 17 parts of polyol (a1-3) having a hydroxyl value of 279 in which PO (3 mol) was added to bisphenol A (1 mol), and hydroxyl group in which PO (5 mol) was added to toluenediamine (1 mol) 38 parts of polyol (a2-3) having a valency of 544 and 10 parts of polyol (a3-1), polyol (a4) 3
5 parts (average number of functional groups of all polyols: 4.19, hydroxyl value: 457), 1.5 parts of "Silicone SH-193", 2 parts of water, 10 parts of "Phiroll CEF", "U-CAT1"
000 "0.9 parts and" HCFC-141b "27.
Preliminarily mix 8 parts and adjust the temperature to 25 ° C.
"Millionate MR-100" 164 temperature-controlled to ℃
The same operation as in Example 1 was performed with the addition of parts to obtain a rigid urethane foam.

Example 4 28 parts of polyol (a1-4) having a hydroxyl value of 243 obtained by adding PO (4 mol) to bisphenol A (1 mol) and hydroxyl group obtained by adding PO (9 mol) to toluenediamine (1 mol) 42 parts of polyol (a2-4) having a valency of 348, 12 parts of polyol (a3-1) and 1 of polyol (a4)
8 parts (average number of functional groups of all polyols 3.71, hydroxyl value 349), "Silicone SH-193" 1.5 parts, water 2
Part, "Phiroll CEF" 10 parts, "U-CAT10
00 "0.9 parts and" HCFC-141b "24.8.
Parts are pre-blended and the temperature is adjusted to 25 ° C.
In the same manner as in Example 1 was added 134 parts of "Millionate MR-100", the temperature of which was adjusted, to obtain a rigid urethane foam.

Example 5 14 parts of polyol (a1-5) having a hydroxyl value of 216 obtained by adding PO (5 mol) to bisphenol A (1 mol) and hydroxyl group obtained by adding PO (11 mol) to toluenediamine (1 mol) 56 parts of polyol (a2-5) having a valency of 295, 15 parts of polyol (a3-1) and polyol (a4)
1.5 parts of "Silicone SH-193" in 15 parts (average number of functional groups of all polyols: 3.95, hydroxyl value: 330)
2 parts water, 10 parts "Phiroll CEF", "U-CAT"
1000 "1.0 part and" HCFC-141b "2
"Millionate MR-100" 1 in which 4.3 parts was preliminarily blended and the temperature was adjusted to 25 ° C, and the temperature thereof was adjusted to 25 ° C 1
The same operation as in Example 1 was carried out by adding 28 parts to obtain a rigid urethane foam.

Example 6 28 parts of polyol (a1-4), polyol (a2-
4) 56 parts and polyol (a3-1) 16 parts (average number of functional groups of all polyols: 3.44, hydroxyl value: 335)
"Silicone SH-193" 1.5 parts, water 2 parts,
"Phiroll CEF" 10 copies, "U-CAT100
0 "1.0 part and" HCFC-141b "23.4 parts were pre-blended and temperature-controlled at 25 ° C, and 119 parts of" Millionate MR-100 "temperature-controlled at 25 ° C were added thereto. The same operation as in 1 was performed to obtain a rigid urethane foam.

Example 7 17 parts of polyol (a1-3) and polyol (a2-
3) 38 parts, 10 parts of polyol (a3-1) and 35 parts of polyol (a4) (average number of functional groups of all polyols: 4.19, hydroxyl value: 457) were added to "Silicone SH-1.
93 "1.5 parts, water 2 parts," Phiroll CEF "10
Part, "U-CAT1000" 0.9 part and "HFC-"
134a "25.1 parts in advance in a pressure resistant container
The temperature was adjusted to ℃, 164 parts of "Millionate MR-100" whose temperature was adjusted to 25 ℃ was added thereto, and the same operation as in Example 1 was performed to obtain a rigid urethane foam.

Comparative Example 1 7 parts of polyol (a1-3), polyol (a2-3)
To 38 parts and 55 parts of polyol (a4) (average number of functional groups of all polyols: 4.69, hydroxyl value: 474), 1.5 parts of "Silicone SH-193", 2 parts of water, 10 parts of "Phiroll CEF", " U-CAT1000 "1.0 part and" HCFC-141b "28.4 parts were pre-blended and the temperature was adjusted to 25 [deg.] C., and" Millionate MR-100 "169 parts whose temperature was adjusted to 25 [deg.] C. was added thereto. The same operation as in Example 1 was performed to obtain a rigid urethane foam.

Comparative Example 2 28 parts of polyol (a1-4), polyol (a3-
1) to 12 parts and 60 parts of polyol (a4) (average number of functional groups of all polyols: 4.34, hydroxyl value: 392),
"Silicone SH-193" 1.5 parts, water 2 parts, "Phiroll CEF" 10 parts, "U-CAT1000" 0.
9 parts and 26.0 parts of "HCFC-141b" were pre-blended, and the temperature was adjusted to 25 ° C, and 146 parts of "Millionate MR-100" whose temperature was adjusted to 25 ° C was added thereto, and the same procedure as in Example 1 was performed. The operation was performed to obtain a rigid urethane foam.

Comparative Example 3 6 parts of polyol (a2-5), polyol (a3-1)
To 15 parts and 79 parts of polyol (a4) (average number of functional groups of all polyols: 5.18, hydroxyl value 441), 1.5 parts of "Silicone SH-193", 2 parts of water, 10 parts of "Phiroll CEF", " U-CAT1000 "1.0 part and" HCFC-141b "27.5 parts were pre-blended and the temperature was adjusted to 25 [deg.] C., to which was added 160 parts" Millionate MR-100 "adjusted to 25 [deg.] C. The same operation as in Example 1 was performed to obtain a rigid urethane foam.

Comparative Example 4 17 parts of a polyol (a1-6) having a hydroxyl value of 280 obtained by adding EO (3 mol) to bisphenol A (1 mol), 38 parts of a polyol (a2-3), and a polyol (a3-1).
In 10 parts and 35 parts of polyol (a4) (average number of functional groups of all polyols: 4.19, hydroxyl value: 457), 1.5 parts of "Silicone SH-193", 2 parts of water, 10 parts of "Phiroll CEF", " U-CAT1000 "1.0 part and" HCFC-141b "27.9 parts were pre-blended and the temperature was adjusted to 25 [deg.] C., and" Millionate MR-100 "164 parts whose temperature was adjusted to 25 [deg.] C. was added thereto. A hard urethane foam was obtained by the same method as in Example 1.

Comparative Example 5 28 parts of polyol (a1-4), polyol (a2-
4) 42 parts, polyol (a3-1) 12 parts and polyol (a4) 18 parts (average number of functional groups of polyol 3.
71, hydroxyl value 349), "Silicone SH-19
3 "1.5 parts, water 2 parts," Phiroll CEF "10
Part, tolylenediamine 5 parts and "HCFC-141
b ”24.9 parts was pre-blended and the temperature was adjusted to 25 ° C, and the temperature was adjusted to 25 ° C in the" Millionate MR-10 ".
The same operation as in Example 1 was carried out by adding 134 parts of "0" to obtain a rigid urethane foam.

The liquid flowability was evaluated by a value (unit: cm / g) obtained by dividing the length (cm) in the long axis direction of the foam by the weight (g), and the compressive strength was measured according to JIS A 9514. It carried out based on the test method (unit: kg / cm ² ). Table 1 shows the liquid flow properties of Examples 1 to 7 and the foam compression strength measurement results, and Table 2 shows the liquid flow properties and foam compression strength measurement results of Comparative Examples 1 to 5.

[0035]

[Table 1] ------------------------------------------ Example NO | 1 2 3 4 5 6 7- −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Liquid Flowability ｜ 0.61 0.62 0.65 0.62 0.63 0.62 0.63 Compressive Strength ｜ 3.2 3.0 3.1 3.0 3.1 3.0 3.0 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

[0036]

[Table 2]

As is clear from Tables 1 and 2, the liquid flow properties of Examples 1 to 7 are clearly higher than the liquid flow properties of Comparative Examples 1 to 5, and the compressive strength of the foam is also high. .

[0038]

EFFECTS OF THE INVENTION By using the rigid urethane foam manufacturing method of the present invention, even if a hydrogen atom-containing halogenated hydrocarbon or water is used as a foaming agent, a resin strength equivalent to that of the conventional CFC-11 is used. And liquid flowability can be realized. The polyurethane foam obtained by the method of the present invention is extremely useful as a heat insulating material for refrigerators, freezers and building materials.

Claims (3)

[Claims] 1. A method for producing a rigid polyurethane foam by reacting a polyol (A) and a polyisocyanate (B) in the presence of a blowing agent (C) comprising a hydrogen atom-containing halogenated hydrocarbon and / or water, As the polyol (A), a propylene oxide adduct (a1) of bisphenol, an alkylene oxide adduct (a2) of toluenediamine, and an alkylene oxide adduct (a3) of ethylenediamine are contained as essential components, and the average functional group number thereof Is 3 to 5 and the hydroxyl value is 300 to
A method for producing a rigid urethane foam, which comprises using a polyol of 550. 2. Based on the weight of polyol (A),
The production method according to claim 1, wherein (a1) is 8 to 28%, (a2) is 24 to 56%, and (a3) is 2 to 16%. 3. The method according to claim 1, wherein (a1) is a polyol obtained by adding 1 to 10 mol of propylene oxide to bisphenols.