JPH03160015A - Production of rigid polyurethane foam - Google Patents

Abstract

PURPOSE:To produce a foam of excellent heat insulation properties while reducing the amount of a fluorocarbon blowing agent used by using a specified amine catalyst in producing a rigid polyurethane foam by reacting a polyisocyanate with a polyol in the presence of a catalyst, a blowing agent, a foam stabilizer, etc. CONSTITUTION:A rigid polyurethane foam is obtained by reacting a polyisocyanate with a polyol in the presence of a catalyst selected between bis[2,2'(N-methylpiperazino)]-ethyl ether of formula l and 2,2'-dimorpholinoethyl ether of formula II, a blowing agent, a foam stabilizer and other adjuvants. The amount of the catalyst used is 0.5-20, preferably 1.0-15 pts.wt. per 100 pts.wt. polyol.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing rigid polyurethane foam with excellent heat insulation properties. [Conventional technology] Hard polyurethane foam has been used in houses, refrigerators,
It is widely used as a heat insulating material for piping, etc. Chlorofluorocarbon compounds are mainly used as blowing agents when manufacturing rigid urethane foams because of their low thermal conductivity. [Problem to be solved by the invention] Recently, it has become clear that chlorofluorocarbon compounds have an adverse effect on the atmospheric environment by destroying the ozone layer, and there is a social need to reduce their usage. As a countermeasure to this problem, the most economical method is to use carbon dioxide gas produced by the reaction between water and polyisocyanate compounds as an alternative blowing agent. However, the thermal conductivity of carbon dioxide gas is inferior to that of chlorofluorocarbon compounds, and furthermore, it diffuses from the rigid polyurethane foam into the atmosphere and replaces air, so there is a problem that the thermal insulation properties of the rigid polyurethane foam are inferior. ．． The present invention was made in view of the above circumstances, and is a method for producing a rigid polyurethane foam that has excellent heat insulation properties, that is, low thermal conductivity, while reducing the amount of chlorofluorocarbon compound used as a blowing agent. The purpose is to provide the following. [Means and effects for solving the problems] The present invention produces a rigid polyurethane foam by reacting a polyhydroxy compound and a polyisocyanate compound in the presence of a catalyst, a blowing agent, a foam stabilizer, and other auxiliaries. In this case, an amine compound represented by bis[2,2゜-(N-methylpiverazino)]ethyl ether (formula 1) and 2,2゛-dimorph-linoethyl ether (formula 2) was used as a catalyst to form a polyhydroxy compound 10.
0.5 to 20 parts by weight, preferably 1.0 parts by weight.
It is characterized by producing a rigid polyurethane film having excellent heat insulation properties, that is, low thermal conductivity, by using the polyurethane film in an amount of 0 to isl parts. That is, the present inventors have been considering substituting water with water in order to reduce the amount of chlorofluorocarbon compounds used as blowing agents, but the products are inevitably high due mainly to the difference in thermal conductivity of the blowing agents themselves Since it becomes a material with thermal conductivity, in order to solve this problem, form) IIj
As a result of intensive research focusing on the size of the cell that produces JiIi, by using amine compounds having specific molecular structures represented by the above formulas 1 and 2 as catalysts,
It was revealed that a rigid polyurethane foam with small cell size and low thermal conductivity could be obtained. The reason why the thermal conductivity of rigid polyurethane membranes decreases as the cell size decreases has traditionally been explained by the increased resistance to radiant heat conduction. Note that the amount of the amine compound used in the present invention is, as described above, based on 100 parts by weight of the polyhydroxy compound.
0.5 to 20 parts by weight, preferably 1.0 to 15 parts by weight, 0.5! l! If it is less than 20 parts by weight, the catalytic effect will be weak and the cell size will not be reduced, and if it exceeds 20 parts by weight, the strength will decrease, which is undesirable. Furthermore, the amine compound used in the present invention can be used alone or in combination with other catalysts as a catalyst for hard polyurethane foam. Catalysts used in combination include, for example, organometallic compounds such as dibutyltin dilaurate and stannous lactate, and amine compounds such as triethylenediamine and tetramethylhexamethylenediamine, which are used in the field of urethane foam production. If so, there are no particular restrictions. There are no particular limitations on the polyhydroxy compounds that can be used in the present invention, and examples include polyether polyols obtained by ring-opening addition polymerization of alkylene oxides such as ethylene oxide and propylene oxide to glycerin, ethylene diakine, etc., and adivic acid. , polyester polyols obtained by the polycondensation reaction of a polybasic acid such as succinic acid with a polyhydroxyl compound such as ethylene glycol or propylene glycol, or by ring-opening polymerization of lactones, etc. You can use a combination of the above. Further, as polyisocyanate compounds that can be used in the present invention, aromatic isocyanates such as diphenylmethane diisocyanate and tolylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, aliphatic isocyanates such as hexamethylene diisocyanate, etc. Their crude products can be used. The amount of the polyisocyanate compound used relative to the total amount of the polyhydroxy compound and other active hydrogen-containing compounds such as water, that is, the incyanate index is preferably in the range of 80 to 130. As blowing agents, water, trichlorofluoromethane, 1,
Chlorofluorocarbons such as 1.2-trichloro-1.2.2-}-lifluoroethane, hydrochlorofluorocarbons such as dichlorotrifluoroethane, dichlorotetrafluoroethane, and bitrochlorocarbons such as al-methylene Hydrocarbons such as , bentane, etc. can be used. The amount of water used is 1 polyhydroxy compound
It is preferably 0.5 to 10 parts by weight, and the others are 0 to 100 parts by weight. Any foam stabilizer that is effective for manufacturing rigid polyurethane foam can be used. For example, polyoxyalkylene-based materials such as polyoxyalkylene alkyl ether, silicone-based materials such as organoborisiloxane, etc. can be used. Furthermore, optional components other than those mentioned above, such as flame retardants, fillers, etc., can also be used within the range that does not interfere with the purpose of the present invention. When producing rigid polyurethane foam from the raw material 4 above, the same method as for ordinary polyurethane foam can be adopted. [Examples] Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples. Examples 1 to 5 According to the formulation shown in Table 1, 2. First, 150 g of polyol was weighed in a paper cup, and a predetermined amount of catalyst, silicone foam stabilizer, and water were added, and after stirring with a propeller type stirrer for about 10 seconds. Then, a predetermined amount of trichloromonofluoromethane was added and thoroughly mixed and stirred for about 30 seconds. Next, a predetermined amount of crude diphenylmethane diisocyanate was added to the homogeneous mixture and stirred at high speed for about 5 seconds at room temperature to dilute the reaction solution.
It was poured into a polyethylene bag set in a 50ms x 250mm x 250mm wooden mold and reacted and foamed at room temperature to obtain a hard polyurethane foam. The obtained rigid polyurethane foam was subjected to after-airing in an oven at 50°C for about 10 minutes. The time required from the start of high-speed stirring after addition of the crude diphenylmethane diisocyanate to the end of the apparent volume increase in the reaction solution was measured, and this time was taken as the foaming and curing time of each foam. Furthermore, the thermal conductivity, density, and cell number of the resulting foam were measured after the foam had been allowed to stand at room temperature for 3 days after the foam had been cured. These results are shown in Table 1. Comparative Example Triethylenediamine was used as an amine catalyst (Comparative Example 1)
, 3.4), and tetramethylhexadiamine (Comparative Example 2), rigid polyurethane foam was obtained in the same manner as in the example according to the recipe in Table 1. The curing time and foam physical properties of the resulting foams were measured in the same manner as in Examples 1 to 5 above, and the results are shown in Table 1. Figure l shows the "number of cells and thermal conductivity" of the example and comparative example.
The black circles (●) indicate Examples 1 to 3 of formulation systems that use a large amount of water, and the white circles (○) indicate Comparative Example 1 of the same type.
- 3, the black triangles (▲) represent Examples 4 and 5 that used a large amount of chlorofluorocarbon, and the white triangles (△> represent Comparative Example 4 of the same type).As shown in the evaluation z1 table and FIG. In the case of Examples 1 to 5 using the amine compound according to the present invention as a catalyst, Comparative Example 1
The cell size was significantly smaller than the Akin-based catalyst foam used in ~4, and as a result, the thermal conductivity was low and good heat insulation properties were exhibited. This effect can be achieved by using the amine catalyst of the present invention alone (Examples 1 and 2.5), in combination with a metal catalyst (Example 3.4), or by using a large amount of chlorofluorocarbon as a blowing agent (Example 4.5). , using a lot of water (Example 1
This is recognized in any of the combination disposals listed in 3) to 3) above. In particular, the low thermal conductivity and excellent insulation performance achieved by formulations that use a large amount of wood (Examples 1 to 3) will greatly contribute to the reduction of fluorocarbons, which is an urgent social need. Table 1] Bosoether boriol manufactured by Takeda Pharmaceutical Co., Ltd.: Gn:
lOc (Off value 425) 2) 3) 4) 5) 6) 7) 8) Silicone foam stabilizer manufactured by Nippon Unicar Kaga: L-5420 Trichlorosonofluoromethane manufactured by Asahi Glass: F-1
1 Dibutyltin dilaurate: Neostan U-100 manufactured by Nitto Kabo ■ Bis E2,2'-(N-methylpiverazino)]ethyl ether manufactured by San-Apro ■ Texaco Inc. Manufactured by 2,2゜-Dimonoleph-Linoethyl Ether Manufactured by Kao ■ 33% solution of triethylene diamine in dipropylene glycol: Kaolizer shame. 31 Tetramethylhexamethylene diamine manufactured by Kao ■ 9) Crude diphenylmethane diisocyanate manufactured by Mitsui Toatsu ■ CR-200 (NCO $ 31. (1) All 6 isocyanate indices are tOS. 10) Measured according to JISA-9514 I
t) Thermal conductivity Measured according to JISA-9514 12) Number of cells The number of cells per inch length is a + I1
[Effects of the Invention] The present invention is capable of increasing the number of cells per unit by using an effective catalyst even if the amount of chlorofluorocarbon compound used as a blowing agent is reduced in the production of rigid urethane foam. , it is possible to obtain a product with low thermal conductivity, and the purpose of head mounting is achieved.

[Brief explanation of the drawing]

Figure 1 is a graph of the relationship between the number of cells and thermal conductivity.

Claims (1)

[Claims] When manufacturing a rigid polyurethane foam by reacting a polyhydroxy compound and a polyisocyanate compound in the presence of a catalyst, a blowing agent, a foam stabilizer, and other auxiliaries, bis[2, 2'-(N-methylpiperazino)]ethyl ether (Formula 1) and 2,2'-dimorpholinoethyl ether (Formula 2) There is an amine compound represented by formula 2 as a polyhydroxy compound 10
A method for producing a rigid polyurethane foam, characterized in that the amount of polyurethane foam is used in a range of 0.5 to 20 parts by weight relative to 0 parts by weight.