JP2000327741A - Production of urethane-modified polyisocyanurate foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing the subject foam low in shrinkage after expanded even in the case of using water singly as foaming agent and good in adhesion to work objects. SOLUTION: The subject urethane-modified polyisocyanurate foam is such one as to have a polyol component composed of 20-80 wt.% of a glycerol-based polyether polyol and 20-80 wt.% of a ethylenediamine-based polyether polyol based on the total polyol. This method for producing the above polyisocyanurate foam comprises using water as foaming agent and a catalyst containing at least one selected from N,N,N',N',N"-pentamethyldiethylenetriamine, N,N,N',N', N",N'''-hexamethyltriethylenetetramine, bis(2-dimethylaminoethyl)ether, 2-(2- dimethylaminoethoxy)ethanol and N,N,N'-trimethylaminoethylethanolamine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed-cell urethane-modified polyisocyanurate foam which can be used as a heat insulating material for architectural insulation or other articles or a joint material thereof, and more particularly, to foaming water. The present invention relates to a method for producing a urethane-modified polyisocyanurate foam which does not have abnormal shrinkage even when used as an agent and has excellent adhesion to a construction object.

[0002]

2. Description of the Related Art Rigid polyurethane foams and urethane-modified polyisocyanurate foams obtained by reacting and foaming a polyol having an active hydroxyl value with a polyisocyanate in the presence of a catalyst, a foaming agent, a foam stabilizer and other compounding agents. Has excellent heat insulation properties, making use of the features that can be sprayed at construction sites, and has been widely used as a heat insulating material for buildings and as a heat insulating and cooling material for various plants. Polyisocyanurate foams are characterized by having flame retardancy and are more preferably used.

In these rigid polyurethane foams and urethane-modified polyisocyanurate foams, hydrochlorofluorocarbons are usually used as a foaming agent. In recent years, for environmental protection, a method for producing a rigid polyurethane foam or polyisocyanurate foam that does not use hydrochlorofluorocarbons having the ability to destroy the earth's ozone layer has been desired. One known solution is to use water as a blowing agent. However, a urethane-modified polyisocyanurate foam using a large amount of water as a foaming agent has a problem that abnormal shrinkage occurs after foaming and that the adhesiveness to an object to be processed is significantly reduced due to brittleness.

[0004] To solve the problems of adhesiveness and shrinkage of rigid polyurethane foams and urethane-modified polyisocyanurate foams using water as a foaming agent, aromatic polyamine-based polyols having a polyol value of 300 to 500 as a polyol component have been proposed. Ethylenediamine polyol having a hydroxyl value of 400 to 500, aromatic polyester polyol having a hydroxyl value of 200 to 500, and a hydroxyl value of 300 to 450
Containing sorbitol-based polyols
JP-A-351620), a mixture using five kinds of specific polyols each having tolylenediamine, triethanolamine, glycerin and ethylenediamine as initiators (JP-A-6-316621), tolylenediamine, ethylenediamine and The use of a mixture of three types of specific polyols and dipropylene glycol each having glycerin as an initiator and a specific silicone foam stabilizer (JP-A-10-45862) is disclosed.

[0005]

However, these conventional rigid polyurethane foams and urethane-modified polyisocyanurate foams, although exhibiting a certain effect, are not yet satisfactory and show further excellent adhesiveness.
In addition, a rigid polyurethane foam or a urethane-modified polyisocyanurate foam that minimizes shrinkage after foaming has been desired.

Accordingly, an object of the present invention is to provide a method for producing a urethane-modified polyisocyanurate foam which has a small shrinkage after foaming even when water is used alone as a foaming agent and has good adhesion to an object to be processed. To provide.

[0007]

Under such circumstances, the present inventors have conducted intensive studies, and as a result, as a polyol component, a specific polyol having glycerin and ethylenediamine as initiators is mixed at a specific compounding ratio, Furthermore, by using a specific tertiary amine catalyst in combination, it is possible to provide a urethane-modified polyisocyanurate foam having no abnormal shrinkage even when only water is used as a foaming agent, and having excellent adhesion to an object to be processed. As a result, the present invention has been completed.

That is, the present invention relates to a method for producing a urethane-modified polyisocyanurate foam using at least a polyol component, a polyisocyanate component, a catalyst and a blowing agent, wherein the polyol component comprises glycerin as an initiator based on all polyols. 20 to 80% by weight of a polyether polyol having ethylene-diamine as an initiator and 20 to 80% by weight of a polyether polyol having ethylenediamine as an initiator, wherein the catalyst comprises N, N, N ', N', N "-pentamethyldiethylenetriamine, N, N, N ', N', N "
, N "'-hexamethyltriethylenetetraamine, bis (2-dimethylaminoethyl) ether, 2- (2-dimethylaminoethoxy) ethanol and N, N, N'-trimethylaminoethylethanolamine An object of the present invention is to provide a method for producing a urethane-modified polyisocyanurate foam, comprising at least one or more tertiary amine catalysts, and wherein the blowing agent is water.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, among the polyol components, examples of the polyether polyol having glycerin as an initiator include a polyether polyol obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to glycerin. Price is 50-7
Those having a hydroxyl value of 100 mgKOH / g are preferably used, and more preferably those having a hydroxyl value of 100 to 500 mgKOH / g. When the hydroxyl value is less than the above range, the strength and dimensional stability of the foam are significantly reduced. On the other hand, if the hydroxyl value exceeds the above range, the foam becomes brittle and rigid, resulting in poor adhesion.
Further, the blending ratio of the polyether polyol having glycerin as an initiator is 20 to 80% by weight, preferably 30 to 50% by weight based on all polyols. Mixing ratio is 2
If the amount is less than 0% by weight, sufficient adhesiveness cannot be obtained.
If it exceeds 0% by weight, the strength and dimensional stability of the foam decrease, and the reactivity during spray foaming decreases,
Sufficient curing cannot be obtained.

The polyether polyol having ethylenediamine as an initiator in the present invention includes polyether polyols obtained by adding one or more alkylene oxides such as ethylene oxide and propylene oxide to ethylenediamine, and the hydroxyl value thereof is preferably 2
00-600 mgKOH / g, more preferably 300-hydroxyl value
500 mgKOH / g can be used. When the hydroxyl value is less than the above range, the strength and dimensional stability of the foam are significantly reduced. On the other hand, if the hydroxyl value exceeds the above range, the foam becomes brittle and rigid, resulting in poor adhesion. The mixing ratio of the polyether polyol having ethylenediamine as an initiator is 20 to 80% by weight, preferably 30 to 50% by weight, based on the total polyol. Mixing ratio is 2
If the amount is less than 0% by weight, sufficient adhesiveness cannot be obtained as in the case of the polyether polyol using glycerin as an initiator. If the amount exceeds 80% by weight, the strength and dimensional stability of the foam decrease. In addition, when spray foaming is performed, the reactivity decreases, and sufficient curing cannot be obtained. The blending ratio of the polyether polyol having glycerin as an initiator and the polyether polyol having ethylene diamine as an initiator is not particularly limited, but is a polyether polyol having glycerin as an initiator / a polyether polyol having ethylene diamine as an initiator. Is 1/3 to 2/1,
In particular, 1/2 to 1/1 is preferable in that sufficient adhesiveness and foam strength can be obtained. It is particularly preferable that the total blending amount of both is 80 to 100% by weight based on all the polyol components.

In the present invention, known polyether polyols and polyester polyols which are usually used as raw materials for rigid polyurethane foams or urethane-modified polyisocyanurate foams can be used as a part of the polyol component. Examples of these polyols include trimethylolpropane, pentaerythritol, tolylenediamine, sorbitol, polyether polyols to which alkylene oxides are added as initiators, and aromatic carboxylic acids such as phthalic acid and polyhydric alcohols. And aromatic polyester polyols obtained by esterification with the compounds. The amount of these polyols is the balance of the essential polyether polyol blended with respect to all polyols, and is specifically 0 to 60% by weight, preferably 0 to 50% by weight.

In the present invention, the polyisocyanate component is not particularly limited, and is a known polyfunctional polyisocyanate, for example, an aromatic, aliphatic or alicyclic polyisocyanate or a mixture thereof, or a mixture thereof. Can be used. Of these, aromatic polyisocyanates such as 2,4 tolylene diisocyanate, 2,6 tolylene diisocyanate, 4,4 ′ diphenylmethane diisocyanate (MDI), and polymethylene polyphenyl isocyanate (crude MDI) are preferred, and polymethylene polyisocyanate is particularly preferred. Phenyl isocyanate can be suitably used.

In the present invention, the equivalent ratio (NCO / OH) of the isocyanate group in the polyisocyanate component to the hydroxyl group in the polyol component is preferably in the range of 1.5 to 4. If the NCO / OH exceeds 4, the adhesiveness of the foam is significantly reduced.

In the present invention, at least N, N, N ', N', N "-pentamethyldiethylenetriamine, N, N, N ', N is used as a catalyst for accelerating the reaction between the polyol component and the polyisocyanate component. ', N ",
N "'-hexamethyltriethylenetetraamine, bis (
At least one selected from 2-dimethylaminoethyl) ether, 2- (2-dimethylaminoethoxy) ethanol, and N, N, N'-trimethylaminoethylethanolamine is used.

[0015] In addition to the above, known catalysts usually used for the production of rigid polyurethane foams can be used in combination. Examples of the catalyst that can be used in combination include, for example, triethylamine, N, N′-dimethylcyclohexylamine, N, N, N ′, N′-tetramethyl1,
Tertiary amine compounds such as 3-propanediamine, N, N, N ', N'-tetramethylhexanediamine, triethylenediamine, 1-isobutyl-2-methylimidazole, dibutyltin dilaurate, stannasoctoate, etc. Metal-based catalysts are exemplified.

As the catalyst, a trimerization catalyst known as a catalyst used in the production of polyisocyanurate foam can be used in combination. Usable trimerization catalysts include, for example, hydroxyl quaternary ammonium salts and alkali metal salts of aliphatic monocarboxylic acids.

In the present invention, water is contained in the polyol component as a blowing agent, preferably in the range of 3 to 8% by weight based on the total polyol. In addition, a foam stabilizer, a flame retardant, and, if necessary, a viscosity reducing agent can be added to the polyol component.

In the present invention, the urethane-modified polyisocyanurate foam is produced by a conventional means. That is, a polyol composition in which an additive other than isocyanate is mixed with a polyol component is prepared in advance, and isocyanate is added thereto, and the mixture is well stirred and foamed and cured. Specifically, using a spray foaming machine, etc., mix the polyol component with additives such as curing catalyst, foam stabilizer, flame retardant, foaming agent, etc., and thoroughly mix the polyisocyanate with the liquid polyol composition. It is manufactured by spraying and foaming the object.

[0019]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but these are merely examples and do not limit the present invention.

Example A polyol composition containing a polyol component, water, a foam stabilizer, a flame retardant, a catalyst and a trimerization catalyst, and a polyisocyanate component were separately prepared according to the formulations shown in Tables 1 and 2. Next, the mixture was sprayed on an aluminum plate having dimensions of 1 m in length, 1 m in width and 5 mm in thickness maintained at room temperature while mixing using a Binks Model G spray foaming machine to form a polyisocyanurate foam. . At this time, spraying was performed so that the thickness of the foam was about 30 mm. Then, the surface of the foam is ground flat, and the diameter,
Glue a cylindrical metal jig with a height of 25 mm, cut along the periphery of the metal jig into the foam,
A portion corresponding to the cross-sectional area of the jig in a planar shape was pulled by a spring balance, the load when the foam was peeled from the aluminum plate was measured, and this was divided by the cross-sectional area of the jig to calculate the adhesive strength.

[0021]

[Table 1]

[0022]

[Table 2]

In Tables 1 and 2, 1) to 13) are as follows. 1) Glycerin-based polyether polyol (MN-1500, manufactured by Mitsui Chemicals) 2) Glycerin-based polyether polyol (MN-400, manufactured by Mitsui Chemicals) 3) Ethylenediamine-based polyether polyol (M420, manufactured by Sumitomo Bayer Urethane) 4) Ethylenediamine-based polyether polyol (Sumitomo Bayer Urethane, H309) 5) Tolylenediamine-based polyether polyol (Sumitomo Bayer Urethane, 0485) 6) Sorbitol-based polyether polyol (Sumitomo Bayer Urethane, M441) 7) Silicone surfactant (L5420, manufactured by Nippon Unicar) 8) Tris (2-chloropropyl) phosphate (Fyrol PCF, manufactured by Akzo Kashima) 9) N, N, N ', N', N "-pentamethyldiethylenetriamine (TOYOCAT DT) 10) Bis (2-dimethylaminoethyl) ether (TOYOCAT ET) 1 1) 1-isobutyl-2-methylimidazole (manufactured by Sankyo Air Products, NC-IM) 12) Quaternary ammonium salts (manufactured by Sankyo Air Products, DABCO TMR) 13) Crude MDI (manufactured by Mitsui Chemicals), M200 )

Examples 1 to 3 are polyether polyols using glycerin as an initiator (glycerin-based polyols).
And a polyether polyol (ethylenediamine-based polyol) using ethylenediamine as an initiator within the range of the present invention, and a strong adhesiveness to an aluminum plate was obtained. In Examples 4 and 5, other polyether polyols were blended in addition to the glycerin-based polyol and the ethylenediamine-based polyol. In the sixth embodiment, N
The CO / OH equivalent was increased to 3.5, and sufficient adhesiveness was also obtained.

As shown in Table 2, in Comparative Examples 1 to 3, one of the glycerin-based polyol and the ethylenediamine-based polyol was missing or the amount was too small. In Comparative Example 4, the polyol was prepared according to the scope of the present invention, but the adhesion was poor because the catalyst was inappropriate. In Comparative Example 5, a glycerin-based polyol and an ethylenediamine-based polyol were used in combination. However, since the mixing ratio was inappropriate, the foam shrank significantly even if the adhesiveness was obtained. In Comparative Example 6, the NCO / OH equivalent was too large, and the adhesiveness was poor.

[0026]

According to the present invention, even when only water is used as a foaming agent, a urethane-modified polyisocyanurate foam which does not have abnormal shrinkage after foaming and has good adhesiveness to an object to be processed is produced. be able to.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasunori Hattori 1-70, Ogurocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Nichiasu Corporation Tsurumi Research Laboratory F-term (reference) 4F074 AA80 BA34 BB08 CA12 CA21 CA26 CC22X DA02 DA32 4J034 BA03 DA01 DB03 DB07 DC50 DF01 DF15 DF22 DG03 DG04 DG14 DG23 HA01 HA02 HA07 HA11 HC12 HC67 HC73 KA01 KB02 KC17 KD02 KD12 KE02 NA03 QA02 QA03 QC01 RA08 RA10

Claims (2)

[Claims] 1. A method for producing a urethane-modified polyisocyanurate foam using at least a polyol component, a polyisocyanate component, a catalyst and a blowing agent.
The polyol component contains, based on all polyols, 20 to 80% by weight of a polyether polyol having glycerin as an initiator and 20 to 80% by weight of a polyether polyol having ethylene diamine as an initiator.
N, N, N ', N', N "-pentamethyldiethylenetriamine, N, N, N ', N', N", N "'-hexamethyltriethylenetetraamine, bis (2-dimethylaminoethyl) ether And at least one tertiary amine catalyst selected from 2,2- (2-dimethylaminoethoxy) ethanol and N, N, N'-trimethylaminoethylethanolamine, wherein the blowing agent is water. A method for producing a urethane-modified polyisocyanurate foam, comprising: 2. An equivalent ratio NC between an isocyanate group in the polyisocyanate and a hydroxyl group in the polyol component.
O / OH is 1.5-4.
A method for producing the urethane-modified polyisocyanurate foam described above.