JPH08176265A - Composition for rigid polyurethane foam - Google Patents

Abstract

PURPOSE: To obtain a rigid polyurethane foam excellent in compression strength and dimensional stability while greatly improving the workability even when an HCFC as a substitute for CFC-11 is used as the blowing agent. CONSTITUTION: In preparing the compsn. contg. an org. diisocyanate, a polyol component, an HCFC as a substitute for CFC-11 as the blowing agent, a catalyst, a surfactant, and other auxiliaries, the polyol component contains an aliph. polyester polyol which has an average functionality of 2.1 or higher and is produced from an aliph. polyhydric alcohol component contg. a trihydric or higher alcohol, a 2C or higher linear aliph. polycarboxylic acid, and an arom. polycarboxylic acid.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a CFC-containing foaming agent.
The present invention relates to a composition for rigid polyurethane foam which is excellent in workability when using CFC substitutes, and is excellent in compression strength and dimensional stability.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a rigid polyurethane foam having excellent heat insulating properties, a method using trichlorofluoromethane (hereinafter abbreviated as CFC-11) as a foaming agent is known. However, in recent years, reduction and elimination of CFC-11, which is one of the causes of ozone layer depletion, have been implemented from the viewpoint of environmental protection.

Therefore, as a foaming agent to replace CFC-11, 1,1-dichloro-1-fluoroethane (HCFC-141b), 2,2-dichloro-1,1, which is called an alternative CFC from the viewpoint of various physical properties, is used. 1-trifluoroethane (HCFC-123),
Monochlorodifluoromethane (HCFC-22), 1, 1, 1,
2-tetrafluoroethane (HFC-134a), 1-chloro-
1,1-Difluoroethane (HCFC-142b) and the like are being used.

However, the rigid polyurethane foam obtained by using these alternative CFCs as a foaming agent has a higher thermal conductivity, a compressive strength and a dimensional stability as compared with a foam foamed using the conventional CFC-11. Markedly reduced. In order to improve this drawback, polyester polyol is used as a polyol component in an amount of 1 to 60% in the polyol.
There is a method of use (JP-A-3-86735).
However, with this method, a foam having satisfactory physical properties and workability cannot be obtained.

There is also a method of using a polyfunctionalized aromatic polyester polyol. For example, a polyfunctional aromatic polyester polyol having an average number of functional groups of 2.1 or more obtained from a polyol containing a polyfunctional alcohol having two or more functional groups and an aromatic polyfunctional carboxylic acid having three or more functional groups may be used. (Kaihei 4-154846), a method of using a polyol containing a trifunctional or higher polyhydric alcohol and a polyfunctional aromatic polyester polyol having an average number of functional groups of 2 or more, which is obtained from an aromatic dicarboxylic acid component (Japanese Patent Application Laid-Open No. Hei 04 (1999) -242945). No. 5-125141).

However, polyfunctional aromatic polyester polyols generally have high viscosity and poor workability. When a foam is produced, it is often the case that non-reactive substances other than polyisocyanate are mixed in advance (premix), but if the viscosity of the polyfunctional aromatic polyester polyol is high, the workability of this step decreases. Further, even when actually producing a foam, the viscosity of the premixed polyol as a whole increases and the workability deteriorates.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to CFC-1.
(1) An object of the present invention is to provide a rigid polyurethane foam composition having a low viscosity, excellent workability, and excellent compressive strength and dimensional stability in the case of a rigid urethane foam composition using an alternative CFC foaming agent.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that when CFC-11 alternative CFCs are used as a blowing agent for rigid polyurethane foams, the number of functional groups is We have found a composition for rigid polyurethane foams that has low viscosity and excellent workability, and has excellent compressive strength and dimensional stability even when a polyester polyol is polyfunctionalized using a polyhydric alcohol of 3 or more. The invention was completed.

That is, the present invention provides (a) an organic diisocyanate, (b) a polyol, (c) a foaming agent comprising CFC-11 surrogate freon, (d) a catalyst, (e) a surfactant and (f) other In a composition for rigid polyurethane foam comprising an auxiliary, the polyol (b) comprises an aliphatic polyhydric alcohol (b-1) containing a polyhydric alcohol having a functional group of 3 or more and a straight chain aliphatic having 2 or more carbon atoms. The present invention relates to a composition for rigid polyurethane foams, which is an aliphatic polyester polyol composed of a polycarboxylic acid (b-2) and having an average number of functional groups of 2.1 or more.

Alternatively, (a) an organic diisocyanate, (b)
A rigid polyurethane foam composition comprising a polyol, (c) a foaming agent composed of CFC-11 alternative CFCs, (d) a catalyst, (e) a surfactant and (f) other auxiliaries, wherein the polyol (b) is An aliphatic polyhydric alcohol (b-1) containing a polyhydric alcohol having 3 or more functional groups, a linear aliphatic polycarboxylic acid (b-2) having 2 or more carbon atoms and an aromatic polycarboxylic acid (b -
The present invention relates to a composition for rigid polyurethane foam, which is an aliphatic polyester polyol having an average number of functional groups of 2.1 or more, which is composed of 3). The average number of functional groups of the polyol (b) is preferably 2.2 to 3.8, and the hydroxyl value of the polyol (b) is preferably 200.
To 600, preferably the polyhydric alcohol (b-1) having 3 or more functional groups is glycerin, and the polyol (b) is an aliphatic polyester polyol (a) and a polyether polyol (b). A composition for rigid polyurethane foam, characterized in that the aliphatic polyester polyol (a) and the polyether polyol (b) have a mixing ratio of 5 to 70% by weight: 30 to 95% by weight. It is provided.

(Structure) The organic isocyanate (a) used in the present invention is not particularly limited,
4-tolylene diisocyanate or 2,6-tolylene diisocyanate or a mixture thereof, m- or p-phenylene diisocyanate, p-xylene diisocyanate, ethylene diisocyanate, tetramethylene-1,4-diisocyanate, hexamethylene-
1,6-diisocyanate, diphenylmethane-4,
4'-diisocyanate, 3,3 'dimethyl-diphenylmethane-4,4'-diisocyanate, 3,3'dimethyl-4,4'-biphenylene diisocyanate, 3,
Various derivatives of 3'dichloro-4,4 'biphenylene diisocyanate, 4,4'-biphenylene diisocyanate or 1,5 naphthalene diisocyanate, crude diphenylmethane diisocyanate (crude MDI) and diphenylmethane diisocyanate can be used. Diphenylmethane diisocyanate is preferred.

Polyol (b) used in the present invention
Is an aliphatic polyester polyol, which is an aliphatic polyhydric alcohol (b) containing a polyhydric alcohol having 3 or more functional groups.
-1) and a linear aliphatic polycarboxylic acid having 2 or more carbon atoms (b-2)
An aliphatic polyhydric alcohol (b-1) having an average number of functional groups of 2.1 or more or containing a polyhydric alcohol of 3 or more functional groups, and a linear aliphatic polycarboxylic acid having 2 or more carbon atoms. An aliphatic polyester polyol having an average number of functional groups of 2.1 or more, which comprises an acid (b-2) and an aromatic polycarboxylic acid (b-3), and preferably has an average number of functional groups of 2.2 to 3.8. Is. The hydroxyl value is preferably 200 to 60.
It is 0, more preferably 300 to 500.

When the average number of functional groups of the aliphatic polyester polyol (a) exceeds 3.8, the viscosity becomes so high that handling is difficult and the workability becomes poor. If the average number of functional groups is less than 2.1, the physical properties of the obtained rigid polyurethane foam will be deteriorated, which is not preferable. If the hydroxyl value of the polyol (a) is less than 200, the viscosity will increase and the handling will be poor. If it exceeds 600, the physical properties of the obtained rigid polyurethane foam are deteriorated, which is not preferable.

One or a mixture of two or more of these aliphatic polyester polyols (a) is a polyol.
The amount added to (b) is not particularly specified, but it is preferable to add and use it in a general polyether polyol (b). The mixing ratio of the aliphatic polyester polyol (a) and the polyether polyol (b) is
(A): (b) = 5-70 wt%: 30-95 wt% is preferable, more preferably 10-55 wt%: 45-9
It is 0% by weight. When the CFC-11 alternative CFC is used, it is possible to obtain a rigid polyurethane foam composition having excellent workability, and having excellent compressive strength and dimensional stability.

Aliphatic polyester polyol (a)
However, when the amount is less than 5% by weight with respect to the polyol (b), the dimensional stability of the foam decreases and the shrinkage increases. On the other hand, when the amount of the aliphatic polyester polyol (a) is more than 70% by weight, the foam strength is lowered, which is not preferable.

The trifunctional or higher polyhydric alcohol (b-
Examples of 1) include glycerin, trimethylolpropane, pentaerythritol, and sorbitol. Especially preferred is glycerin.

Examples of other alcohols to be mixed with these polyhydric alcohols (b-1) include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1, 4-butanediol, 1,3-butanediol, neopentyl glycol, hexamethylene glycol, dipropylene glycol, 3-methyl-
Bifunctional alcohols such as 1,5-pentanediol and 1,9-nonanediol may be mentioned.

A straight-chain aliphatic dicarboxylic acid having 2 or more carbon atoms (b
As -2), those having 2 to 20 carbon atoms such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and the like are preferable, and one kind or a mixture thereof may be used.

Examples of the aromatic polyvalent carboxylic acid (b-3) used as a mixture with these linear aliphatic dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid and their anhydrides. . The aromatic polycarboxylic acid is
Used together to improve the physical strength of the foam. However, the ratio of the aromatic polycarboxylic acid (b-3) in the acid component is
Good workability, preferably 70% by weight
The following is more preferable and 50% by weight or less is more preferable.

The synthesis of these polyester polyols is carried out according to the usual known methods.

Further, in addition to the above-mentioned specific polyol, an ordinary polyol can be used in combination, and various known polyols for rigid urethane foam can be used as the polyol.

As the polyether polyol (b),
For example, ethylene glycol, propylene glycol,
Diethylene glycol, triethylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, pentaerythritol, sorbitol, shoe cloth, bisphenol A, polyhydric alcohols such as novolac, and / or polys thereof. Examples thereof include those obtained by addition-polymerizing an alkylene oxide with a hydroxy compound, preferably a hydroxyl value of 20.
There are 0 to 800 mg KOH / g polyether polyol.

In addition, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, active hydrogen such as ethylenediamine, diethylenetriamine, triethylenetetramine and toluenediamine are used as 2
One or more compounds and / or amines obtained by addition-polymerizing ethylene oxide, propylene oxide, butylene oxide, styrene oxide, or the like are also included, and the hydroxyl value is preferably 200 to 800.
mgKOH / g polyether polyol and polytetramethylene glycol can also be used.

For producing the rigid polyurethane foam of the present invention, a foaming agent (c) comprising CFC-11 alternative CFC.
To use. Examples of the foaming agent (c) include hydrochlorofluorocarbons and hydrofluorocarbons.

Examples of hydrochlorofluorocarbons include 1,1-dichloro-1-fluoroethane (HCF)
C-141b), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), monodichlorofluoromethane (HCF
C-22), 1-chloro-1,1-difluoroethane (HCFC-1
42b) and the like. Further, as hydrofluorocarbons, 1,1,1,2-tetrafluoroethane (H
FC-134a). These may be used alone or in combination of two or more.

As the catalyst (d) which can be used in the present invention, all the catalysts usually used in the production of polyurethane foam can be used. For example, N, N, N ', N'-tetramethylhexamethylenediamine, pentamethyldiethylenetriamine, triethylamine, N, N, N', N '
Examples include -1,3-butanediamine and the like.

The surfactant (e) of the present invention is not particularly limited. Conventionally known organosilicon surfactants can be used. For example, L-501, L-520, L manufactured by Nihon Unicar
-532, L-540, L-544, L-3550, L-5302, L-5305, L-532
0, L-5340, L-5410, L-5420, L-5710L-5720 etc., SH-190, SH-192, SH-19 manufactured by Torre Silicone
4, SH-195, SH-200, SRX-253, and Shin-Etsu Silicone F-114, F-121, F-122, F-220, F-230, F-25
8, F-260, F-305, F-306, F-341, etc., and FTA-4200, THA-4202, etc. made by Toshiba Silicone.

Next, in the present invention, in addition to the above-mentioned components, a foam stabilizer, a flame retardant, a plasticizer, a filler, a stabilizer, a colorant and the like can be added as other auxiliary agents as required.

The rigid polyurethane foam of the present invention can be produced by a generally known method.

[0030]

EXAMPLES The present invention will now be specifically described with reference to examples, but the invention is not limited thereto. In addition, “part” and “%” in the text are based on weight.

The respective raw materials used in the examples are shown below.

<Polyester polyol>"PolyolA" Polyester polyol synthesized from glycerin / diethylene glycol and adipic acid, hydroxyl value 450 mgKOH / g, average number of functional groups 3.0 "Polyol B" Polyester polyol synthesized from glycerin / diethylene glycol and adipic acid , Hydroxyl value 450mgKOH / g, average number of functional groups 2.5

"Polyol C" Polyester polyol synthesized from glycerin / diethylene glycol and adipic acid, hydroxyl value 450 mgKOH / g, average number of functional groups 3.5 "Polyol D" Glycerin / diethylene glycol, polyester polyester synthesized from adipic acid and phthalic anhydride , Hydroxyl value 450mgKOH / g, average number of functional groups 3.0

"Polyol E" polyester polyol synthesized from trimethylolpropane / diethylene glycol and adipic acid, hydroxyl value 450 mg KOH / g, average number of functional groups 3.0 "Polyol F" glycerin / diethylene glycol and polyester polyol synthesized from phthalic anhydride,
Hydroxyl value 450 mg KOH / g, average number of functional groups 3.0

"Polyol G" Polyester polyol synthesized from trimethylolpropane / diethylene glycol and phthalic anhydride, hydroxyl value 450 mg KOH / g, average number of functional groups 3.0 "Polyol H" glycerin / diethylene glycol polyester polyol synthesized from adipic acid, Hydroxyl value 450 mg KOH / g, average number of functional groups 4.0

"Polyol I" Polyester polyol synthesized from diethylene glycol and adipic acid, hydroxyl value 315 mgKOH / g, average number of functional groups 2.0 "Polyol J" Polyethylene polyol having hydroxyl value 450 mgKOH / g added with propylene oxide to ethylenediamine

C-MDI: made of Nippon Polyurethane, crude diphenylmethane diisocyanate coronate 1110

◎ Flame retardant: Tri-chloropropyl phosphate manufactured by Daihachi Chemical Co., Ltd. ◎ Foam stabilizer: SH-193 manufactured by Toray Silicon Co., Ltd. ◎ Catalyst: Tetramethylhexamethylenediamine manufactured by Tosoh Co., Ltd. ◎ Foaming agent : Central Glass Co., Ltd. HCFC-141b dichlorofluoroethane

Examples 1 to 5 and Comparative Examples 1 to 4 Table 1 shows the evaluation of the viscosity (25 ° C.) and workability of each polyester polyol. A rigid polyurethane foam was obtained by using the components shown in Table 2.

That is, first, each raw material other than the polyisocyanate shown in Table 2 was premixed, crude diphenylmethane diisocyanate was added thereto, and the mixture was vigorously stirred.
It was poured into a mold of × 200 × 100 mm and allowed to freely foam to obtain a rigid polyurethane foam.

The NCO / OH equivalent ratio was 1.15. The dimensional stability was measured by the volume change rate when stored at 25 ° C. for 48 hours.

The workability was evaluated as follows: the polyester polyol having a viscosity (25 ° C.) lower than 4000 cps is ◯, 4000
〜8000cps is △, and 8000cps is ×.

[0043]

[Table 1]

[0044]

[Table 2]

[0045]

EFFECTS OF THE INVENTION The composition for rigid polyurethane foam of the present invention is excellent in compressive strength and dimensional stability even when CFC-11 alternative CFC is used as a foaming agent, and can greatly improve workability. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 75:04

Claims (7)

[Claims] 1. A foaming agent comprising (a) an organic diisocyanate, (b) a polyol, (c) CFC-11 alternative CFCs, and (d).
In the composition for rigid polyurethane foam, which comprises a catalyst, (e) a surfactant, and (f) other auxiliaries, the polyol
(b) is an average number of functional groups consisting of an aliphatic polyhydric alcohol (b-1) containing a polyhydric alcohol having 3 or more functional groups and a linear aliphatic polycarboxylic acid (b-2) having 2 or more carbon atoms. A composition for rigid polyurethane foams, which comprises an aliphatic polyester polyol (a) of 2.1 or more. 2. A foaming agent comprising (a) an organic diisocyanate, (b) a polyol, (c) a CFC-11 alternative CFC, and (d).
In the composition for rigid polyurethane foam, which comprises a catalyst, (e) a surfactant, and (f) other auxiliaries, the polyol
(b) is an aliphatic polyhydric alcohol containing a polyhydric alcohol having 3 or more functional groups (b-1), a linear aliphatic polycarboxylic acid having 2 or more carbon atoms (b-2), and an aromatic polyhydric alcohol. A composition for a rigid polyurethane foam, which comprises an aliphatic polyester polyol (a) having an average number of functional groups of 2.1 or more and composed of a carboxylic acid (b-3). 3. The average number of functional groups of the polyol (b) is 2.
The composition for rigid polyurethane foams according to claim 1 or 2, wherein the composition is 2 to 3.8. 4. The hydroxyl value of the polyol (b) is from 200 to 200.
The composition for rigid polyurethane foams according to claim 1, wherein the composition is 600 mgKOH / g. 5. A polyhydric alcohol (b-1) having 3 or more functional groups
Is glycerin, The composition for rigid polyurethane foams according to claim 1, wherein 6. The composition for rigid polyurethane foams according to claim 1, wherein the polyol (b) comprises an aliphatic polyester polyol (a) and a polyether polyol (b). 7. Aliphatic polyester polyol (a)
The composition for rigid polyurethane foam according to claim 6, characterized in that: and the polyether polyol (b) have a mixing ratio of 5 to 70% by weight: 30 to 95% by weight.