JPH0137405B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyether polyol composition (hereinafter simply referred to as polyether) for producing rigid polyurethane foams. Conventionally, rigid polyurethane foam has been foamed by mixing and reacting a liquid mainly consisting of a polyol component and a liquid mainly consisting of an organic polyisocyanate component. Because it can be foamed relatively easily and has relatively good physical properties, it can be used to make slabs or inject into molds to make mold forms for electric refrigerators, freezers, cold storage boxes, and construction. It is widely used for cold and heat insulation materials, sound absorbing materials, synthetic wood, etc. The polyether polyols used in these rigid polyurethane foams were synthesized by adding propylene oxide to sucrose, mainly glycerin and/or water (e.g.
USP2990376), but these materials have poor compatibility with organic polyisocyanates, and when tolylene diisocyanate-based organic polyisocyanates are used, the surface of the foam becomes brittle, so when injected into a mold. However, the disadvantage was that demolding time was long. Furthermore, if measures were taken to shorten demolding time by increasing the curing speed of the foam, the amount of catalyst used would be extremely large, which would be very disadvantageous in terms of raw material cost. had the disadvantage that it acts as a plasticizer and significantly impairs the physical properties of the foam. In terms of compatibility with organic polyisocyanates,
Propylene oxide adducts such as ethylene diamine, tolylene diamine, and methylene dianiline are good, but they have the disadvantage of high viscosity. Forms based on polyethers from sucrose and aliphatic amines (Japanese Patent Publication No. 48-3720) required a considerably larger amount of catalyst to be used. In addition, the brittleness of the foam surface is due to the polyether polyol.
This can be improved by lowering the OH value and the number of functional groups, but in this case, the physical properties of the foam, especially the dimensional stability at low temperatures, deteriorated significantly, making it impossible to obtain a foam with a low specific gravity. The present inventors conducted various studies based on the technical idea that by improving the polyether polyol and reducing the cell diameter of the foam, the heat insulating properties (thermal conductivity) could be improved. We have arrived at the present invention. That is, the present invention includes 80 to 50 parts by weight of sucrose (the following parts indicate parts by weight), 10 to 30 parts of ethylenediamine,
This is a polyether polyol composition for producing a rigid polyurethane foam, which is prepared by adding 3 to 30 parts of ethylene oxide and 97 to 70 parts of an alkylene oxide other than ethylene oxide to a mixture of 10 to 40 parts of triethanolamine. If the amount of sucrose is less than 50 parts, the average number of functional groups in the resulting polyether will be low, resulting in poor physical properties when a low-density rigid polyurethane foam is produced. If the amount exceeds 80 parts, synthesis of polyether becomes difficult, and the compatibility and reactivity with organic polyisocyanate deteriorates. If the amount of ethylenediamine is less than 10 parts, the resulting polyether will have poor compatibility with the organic polyisocyanate and will also have poor reactivity, resulting in poor cell structure of the resulting foam. Moreover, if the amount exceeds 30 parts, the reactivity of the polyether becomes rapid, resulting in processing difficulties when producing a practical injection foam. If the amount of triethanolamine is less than 10 parts, it will be impossible to reduce the viscosity of the polyether, and the reactivity will be poor, resulting in poor cell structure of the foam. If the amount exceeds 40 parts, the reactivity of the polyether with the organic polyisocyanate becomes extremely rapid, so that it can only be used for special purposes. The alkylene oxide other than ethylene oxide in the present invention includes propylene oxide, butylene oxide, styrene oxide, etc. alone or as a mixture, and the amount used is 97 to 70 parts. Ethylene oxide in the present invention is used in the form of a block (there is no restriction on the order of addition), a random shape, or a terminal cap shape together with the above-mentioned alkylene oxide, and the amount used is 3 to 30 parts. When the amount of ethylene oxide is less than 3 parts, there is no effect of reducing the viscosity of the polyether, and the reactivity does not become rapid, resulting in poor cell structure of the foam. or
If it exceeds 30 parts, the compatibility with Freon becomes poor, which is not preferable. The average OH value of polyether in the present invention is
It is preferably 350 to 600, more preferably
It is 400-550. If the average OH number is less than 350, the physical properties of the foam will deteriorate, and if it exceeds 600, the compatibility with Freon and with organic polyisocyanate will be poor. The polyether in the present invention is produced by a conventionally known method. Usually, alkylene oxide and ethylene oxide are added to a mixture of sucrose, ethylenediamine, and triethanolamine by the method of the present invention, but if necessary, alkylene oxide and ethylene oxide are added to the mixture of sucrose and ethylenediamine by the method of the present invention. A method of blending a product obtained by adding alkylene oxide and ethylene oxide to a mixture of sucrose and triethanolamine by the method of the present invention, and a method of adding a similar addition to ethylenediamine to a mixture of sucrose and triethanolamine. It is also possible to use a method of blending those that have been performed. Furthermore, a method of blending sucrose, ethylenediamine, and triethanolamine to which alkylene oxide and ethylene oxide are added by the method of the present invention, respectively, can also be used. The organic polyisocyanates used in producing the rigid polyurethane foam from the polyether polyol composition of the present invention are conventionally known ones and are not limited, but include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate,
The isomer ratio of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate is 80/20,
65/35 mixture, crude tolylene diisocyanate,
4,4'-diphenylmethane diisocyanate, conventionally known 4,4'-diphenylmethane diisocyanate modified with carbodiimide, crude diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, o-, m- or p- Xylene diisocyanate, hexamethylene diisocyanate, etc., dimers and trimers of these organic polyisocyanates, and some of these organic polyisocyanates modified with known low-molecular polyols or polyether polyols, etc., which may be used alone or in combination. used. The amount of organic polyisocyanate used is NCO/H
(Active hydrogen) = 0.70 to 1.40 (equivalent ratio). As the foaming aid, a foaming catalyst, a foaming agent, a foam stabilizer, etc. are used. As the blowing catalyst, conventionally known amine compounds, organic tin compounds, etc. are used, and as the blowing agent, water, trichloromonofluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethane, monochlorodifluoromethane, methylene chloride, etc. are used. It will be done. The foam stabilizer is a silicone-based or liquid paraffin-based foam stabilizer having a polysiloxane skeleton. Foaming can be carried out by a one-shot foaming method, a prepolymer method, or a semi-prepolymer method. By combining specific amounts of sucrose and ethylenediamine in the polyether of the present invention,
The poor compatibility of polyether made from sucrose with organic polyisocyanate was improved, and by adding a specific amount of triethanolamine, the viscosity of the resulting polyether could be lowered. Due to the high reactivity of polyether polyols such as ethylenediamine and triethanolamine with organic polyisocyanates, it is possible to reduce the amount of catalyst during foam production, and furthermore, by speeding up the initial reaction with organic polyisocyanates, It was discovered that it became possible to make the cells uniform and fine, and that the heat insulation properties could be significantly improved. Further, by adding ethylene oxide, it is possible to lower the viscosity of polyether without lowering the functional groups of polyether, and a foam with good physical properties can be obtained. In addition, by adding ethylene oxide, the surface tension becomes closer to that of organic polyisocyanate than polyether polyols added with propylene oxide such as ethylenediamine and tolylene diamine, which improves the miscibility with organic polyisocyanate. ,
Furthermore, the effect of using ethylenediamine and triethanolamine and the effect of adding ethylene oxide work synergistically, making the initial reaction with the organic polyisocyanate even faster, making the cells of the foam even finer, and improving the insulation properties. could be significantly improved. The rigid polyurethane foam according to the present invention can be used in a wide range of fields such as electric refrigerators, freezers, cold storages, insulation materials for cold and heat insulation for buildings, sound absorbing materials, synthetic wood, etc. EXAMPLES Next, the present invention will be specifically explained using Examples, Reference Examples, and Comparative Examples, but the present invention is not limited by these in any way. Example 1 70 parts of sucrose, 10 parts of ethylenediamine, and 20 parts of triethanolamine were placed in an autoclave.
After adding 0.17 parts of caustic soda and replacing with nitrogen,
While maintaining the reaction temperature at 100° C., 214 parts of propylene oxide was introduced, and after the reaction was completed, an additional 23 parts of ethylene oxide was introduced at the same temperature. The reaction-completed product was neutralized with theoretical hydrochloric acid and treated under reduced pressure to remove volatile parts to obtain 330 parts of polyether (A). The obtained polyether had an OH value of 450, a viscosity of 19,400 cps (25°C), and an ethylene oxide content (same below the theoretical weight % based on the sum of alkylene oxide and ethylene oxide) of 9.7% by weight (hereinafter % indicates weight%). ), theoretical number of functional groups
It was 5.36. Example 2 50 parts of sucrose, 10 parts of ethylenediamine, and 40 parts of triethanolamine were placed in an autoclave, 0.15 parts of caustic soda was added, and after purging with nitrogen, 10 parts of ethylene oxide was introduced while maintaining the reaction temperature at 100°C. After that, 200 parts of propylene oxide was introduced and the reaction was carried out at the same temperature. This reaction product was treated in the same manner as in Example 1 to remove volatiles to obtain 290 parts of polyether (B). The obtained polyether has an OH value of 480 and a viscosity of 6000 cps (25℃)
The theoretical ethylene oxide content was 5% and the theoretical number of functional groups was 4.5. Example 3 65 parts of sucrose, 20 parts of ethylenediamine and 15 parts of triethanolamine were charged into an autoclave,
After adding 0.16 parts of caustic potash and purging with nitrogen, 264 parts of propylene oxide was introduced while maintaining the reaction temperature at 100°C. After the reaction was completed, 29 parts of ethylene oxide was introduced at the same temperature to carry out the reaction. The obtained reaction product was treated in the same manner as in Example 1 to obtain 354 parts of polyether (C). The obtained polyether is
OH value 450, viscosity 11000 cps (25℃), theoretical ethylene oxide content 9.9%, theoretical number of functional groups
It was 5.06. Example 4 80 parts of sucrose, 10 parts of ethylenediamine and 10 parts of triethanolamine were placed in an autoclave,
After adding 0.13 parts of caustic soda and replacing with nitrogen,
A mixture of 80% propylene oxide and 20% ethylene oxide 219 while keeping the reaction temperature at 100°C.
The reaction was carried out. The reaction product obtained was treated in the same manner as in Example 1, and 297 parts of polyether
I got (D). The obtained polyether has an OH value of 485,
The viscosity was 18,500 cps (25°C) and the theoretical number of functional groups was 5.86. Reference Examples 1 to 16, Comparative Examples 1 to 3 Table 1 shows the foaming results using the polyethers synthesized in Examples 1 to 4. For foaming, add a specified amount of catalyst, blowing agent, and foam stabilizer to each polyether, mix with a stirrer, adjust the temperature to 20℃, add a specified amount of organic polyisocyanate whose temperature has been adjusted to 20℃, and stir. The mixture was forcibly stirred in a machine and poured into a vertical aluminum mold with a thickness of 3.5 cm, a width of 30 cm, and a height of 30 cm. As shown in Table 1, it can be seen that the physical properties of the rigid polyurethane foam using the polyether of the present invention are extremely excellent. The raw materials used in the reference example were as follows. (1) Freon F-11: Mitsui Fluorochemical product. Trichlormonofluoromethane (2) L-5420: Nippon Unicar product. Silicone foam stabilizer (3) MINICO-4010: Mitsui Nisso urethane product. Urethane catalyst (4) Kaolizer No. 1: Kao soap product. Urethane catalyst (5) PMDETA: N, N, N′, N″, N-petanemethyldiethylenetriamine (6) TRC-90A: Mitsui Toatsu Chemicals. Crude tolylene diisocyanate (NCO=39%) (7) MDI -CR: Mitsui Toatsu Chemicals. Crude diphenylmethane diisocyanate (NCO = 31%) (8) TRC-90A pre: Polyisocyanate in which a part of TRC-30A is prepolymer modified with polyether polyol (NCO = 31%) ) (9) Polyether (E): 70 parts of sucrose, 30 parts of glycerin
OH value with propylene oxide added to
460, viscosity 17000 (25℃), theoretical functional group number 4.93. (10) Polyether (F): Propylene oxide added to 90 parts of sucrose and 10 parts of ethylenediamine
OH number 450, viscosity 80000cps (250℃). The test method used in the reference example is as follows. (1) Form status during demolding When using TRC-90A, demolding takes 7 minutes, TRC-90A/MDI-CR and
TRC-90A pre/MDI-CR is 4 minute demolding, MDI
-CR was evaluated based on the following evaluation criteria based on the observation of flyability after 3 minutes of demolding. 〓: Very good ◎: Good 〇: Fairly good ×: Poor (2) Low-temperature dimensional stability (%) Rate of change in volume after being left at -30℃ for 48 hours (3) Cell diameter (mm) Depends on the electron microscope environment measurement

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Claims (1)

[Claims] 1 80-50 parts by weight of sucrose, 10-50 parts by weight of ethylenediamine
A polyether polyol composition for manufacturing a rigid polyurethane foam, which is obtained by adding 3 to 30 parts by weight of ethylene oxide and 97 to 70 parts by weight of an alkylene oxide other than ethylene oxide to a mixture consisting of 30 parts by weight and 10 to 40 parts by weight of triethanolamine. thing.