JP2011213854A - Method for manufacturing rigid polyurethane foam and composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method in which: even if water is contained in a polyol component beforehand, hydrolysis of the polyol component is controlled, the reactivity with polyisocyanate falls off is suppressed, and normal rigid polyurethane foam is formed; and to provide a composition.SOLUTION: The method of manufacturing rigid polyurethane foam comprises the following. As a foaming agent, carbon dioxide generated by a reaction of water and a polyisocyanate component, and carbon dioxide of at least one state of a supercritical state, a subcritical state, and a liquid state are used together; and water is beforehand contained in a polyol component, carbon dioxide of a liquid state is added to a polyol component under transfer in a passage to a mixing head before mixing a polyisocyanate component and a polyol component in the mixing head, and then the rigid polyurethane foam is manufactured. At least four of an alkylation polyalkylene polyamine, a quaternary ammonium salt, dimethylimidazole, and triethylenediamine are contained as a catalyst in the polyol component.

Description

  The present invention relates to a method and a composition for producing a rigid polyurethane foam.

  Rigid polyurethane foam is excellent in heat insulation, moldability and the like, and is widely used as a heat insulating material and a structural material for houses, refrigerated warehouses and the like. At present, in the production of this rigid polyurethane foam, a method of utilizing carbon dioxide generated by the reaction of water and polyisocyanate as a foaming agent is common.

  However, when a rigid polyurethane foam is produced using only such carbon dioxide, the rate at which carbon dioxide in the bubbles (cells) formed in the foam diffuses out of the bubbles is the speed of the air flowing into the bubbles. Since it is faster than the speed, there is a drawback that the internal pressure of the bubble is lowered and the bubble is easily contracted.

  In order to solve this problem, the present inventor previously used carbon dioxide in a supercritical state, subcritical state, or liquid state as a blowing agent in addition to carbon dioxide generated by the reaction of conventional water and polyisocyanate. A technique of improving the dimensional stability by bringing the cell shape closer to a sphere by using the combination is proposed (see Patent Document 1).

JP 2004-107376 A

  However, the water of Patent Document 1 is added to the polyol component being transferred in the flow path leading to the mixing head before mixing of the polyisocyanate component and the polyol component at the mixing head. That is, since the water is added as a component different from the polyol component and the polyisocyanate component, ancillary equipment such as a meter is required.

  On the other hand, when water is previously contained in the polyol component, when the polyol at that time is particularly a polyester polyol, it has a property of being easily hydrolyzed, so the polyol component containing water has poor stability over time, It changes in a relatively short time. For this reason, the reactivity with the polyisocyanate is lowered, and there is a possibility that a normal rigid polyurethane foam cannot be formed.

  Accordingly, the present invention provides a rigid polyurethane foam that forms a normal rigid polyurethane foam by suppressing hydrolysis of the polyol component and suppressing a decrease in reactivity with the polyisocyanate even if water is previously contained in the polyol component. An object of the present invention is to provide a production method and a composition.

  As a result of diligent research and various studies, the present inventor, as a foaming agent, carbon dioxide generated by the reaction of water and a polyisocyanate component, and carbon dioxide in at least one of a supercritical state, a subcritical state, and a liquid state. And the water is contained in the polyol component in advance, and the carbon dioxide in the liquid state is transferred through the flow path to the mixing head before mixing the polyisocyanate component and the polyol component in the mixing head. A method for producing a rigid polyurethane foam by adding to the polyol component therein, wherein the polyol component contains at least four kinds of alkylated polyalkylene polyamine, quaternary ammonium salt, dimethylimidazole, and triethylenediamine as a catalyst. The water is pre-polyol Be contained in the minute, to suppress the hydrolysis of the polyol component, suppress the reactivity with the polyisocyanate is decreased, they found that the resulting normal rigid polyurethane foam, and completed the present invention.

  According to the production method and composition of the present invention, even if water is previously contained in the polyol component, the hydrolysis of the polyol component is suppressed, and the decrease in reactivity with the polyisocyanate is suppressed. A form is obtained. In addition, there is no need for incidental facilities for adding water.

It is a figure which shows the one aspect | mode of the manufacturing apparatus of a rigid polyurethane foam.

  The production method of the present invention uses, as a foaming agent, carbon dioxide generated by the reaction of water and a polyisocyanate component and carbon dioxide in at least one of a supercritical state, a subcritical state, and a liquid state. And the water previously contained in the polyol component, and before the mixing of the polyisocyanate component and the polyol component in the mixing head, the liquid carbon dioxide is transferred to the polyol component being transferred in the flow path to the mixing head. A method of producing a rigid polyurethane foam by adding, wherein the polyol component contains at least four kinds of alkylated polyalkylene polyamine, quaternary ammonium salt, dimethylimidazole, and triethylenediamine as a catalyst. And

  The apparatus used in the production method of the present invention contains water and a catalyst in the polyol component in advance, and the liquid carbon dioxide is added to the polyol component before mixing the polyisocyanate component and the polyol component at the mixing head. 1 is set to the polyol component being transferred in the flow path leading to the mixing head. For example, an apparatus as shown in FIG. 1 can be used.

  In FIG. 1, a polyisocyanate component 1 is measured by a metering pump 3 connected from a tank 2 via a pipe 4, passes through a heater unit 5 for heating to a set temperature, and a heating hose 6, and then a mixing head 10. It is transferred to. On the other hand, the polyol component 11 is measured from a tank 12 by a metering pump 13 connected via a pipe 14 and transferred to a mixing head 10 via a heater unit 15 and a heating hose 16 for heating to a set temperature. The

  The carbon dioxide in the carbon dioxide cylinder 7 is measured by a metering pump 8 that operates in conjunction with each pump, is introduced into the polyol component through a pipe 9 connected to the pipe 14, and is being transferred through a flow path to the mixing head 10. In the polyol component. At this time, the mixing efficiency may be further increased by providing a static mixer between the carbon dioxide input position and the mixing head.

  In the mixing head 10, the polyisocyanate component and the polyol component (mixed with carbon dioxide and water) are impinged and mixed and ejected into the atmosphere with a liquid or foam mist, and then reacted and cured to form a rigid polyurethane foam. It is formed.

  As the blowing agent of the present invention, carbon dioxide generated in a reaction between water and a polyisocyanate component is used together with carbon dioxide in a supercritical state, a subcritical state, or a liquid state. Disadvantages of using only carbon dioxide generated by the reaction of water and polyisocyanate by using carbon dioxide in the supercritical state, subcritical state, or liquid state: α) To prevent shrinkage It is necessary to increase the density and increase the cost. Β) On the other hand, a large amount of water is required to decrease the density, excessive urea bonds occur, and the resulting foam tends to become brittle. A foam having excellent workability and dimensional stability can be obtained.

  And since this invention contains water in a polyol component previously, it can manufacture a rigid polyurethane foam without an incidental installation. The amount of water previously contained in the polyol component is preferably 4 to 8 parts by weight with respect to 100 parts by weight of the polyol in the polyol component. If it is less than 4 parts by weight, foaming is insufficient and the density of the hard polyurethane foam to be produced becomes high, and it becomes difficult to pass the flame retardant material by the exothermic test. On the other hand, when the amount exceeds 8 parts by weight, excessive urea bonds are formed, and the resulting rigid polyurethane foam tends to be brittle and the adhesiveness tends to decrease.

  The amount of liquid carbon dioxide added to the polyol component of the present invention depends on the density of the rigid polyurethane foam to be produced, the polyisocyanate component, and the viscosity of the polyol component. Is preferably 0.5 to 3% by weight, and more preferably 1 to 2% by weight.

  In the present invention, liquid carbon dioxide is added to the polyol component, and the polyol component is heated to 45-50 ° C. and 6 MPa or more (preferably 7-7.5 MPa) before mixing with the polyisocyanate component. By pressurizing, the carbon dioxide in the liquid state can be brought into a supercritical state and a subcritical state. In the case of using an apparatus configured as shown in FIG. 1, the polyisocyanate component and the polyol component in which liquid carbon dioxide and water are mixed are mixed as described above in the flow path leading to the mixing head 10. The carbon dioxide in the above state can be appropriately prepared by appropriately setting the temperature and pressure within the above range.

  Carbon dioxide has a high diffusion coefficient in the supercritical state or the subcritical state, and exhibits a remarkable effect of making the bubbles of the rigid polyurethane foam fine. Further, the action of three kinds of catalysts described later is added, and the workability can be improved by accelerating the reaction rate between the polyol component and the polyisocyanate component without using a heavy metal catalyst.

  In the present invention, “subcritical carbon dioxide” means carbon dioxide in a liquid state in which the pressure is not less than the critical pressure of carbon dioxide and the temperature is lower than the critical temperature, or the critical pressure of carbon dioxide. In a liquid state in which the temperature is lower than the critical temperature or higher than the critical temperature, or the temperature and pressure are both lower than the critical point but close to this, specifically, the temperature is around 20 ° C. and the pressure Refers to carbon dioxide around 5 Mpa. In addition, “supercritical carbon dioxide” refers to carbon dioxide whose pressure is higher than the critical pressure of carbon dioxide and whose temperature is higher than the critical temperature.

  As the catalyst contained in the polyol component of the present invention, four types of alkylated polyalkylene polyamine, quaternary ammonium salt, dimethylimidazole and triethylenediamine are used. By containing these four types of catalysts in the polyol component, even if water is previously contained in the polyol component, hydrolysis of the polyol component is suppressed, and the decrease in reactivity with the polyisocyanate is suppressed. A rigid polyurethane foam can be obtained.

  In the present invention, 1 to 6 parts by weight of alkylated polyalkylene polyamine, 2 to 5 parts by weight of quaternary ammonium salt, 2 to 6 parts by weight of dimethylimidazole, and triethylenediamine with respect to 100 parts by weight of polyol in the polyol component. Is preferably 2 to 6 parts by weight.

  In the present invention, as the catalyst, only the above four types of compounds may be used, or other catalysts may be used in combination as long as the above-described effects are not inhibited.

  The polyol component used in the present invention may be an aromatic polyester polyol alone or a combination of an aromatic polyester polyol and a polyether polyol. Examples of aromatic polyester polyols include polyols derived from phthalic anhydride, polyethylene terephthalate scrap, dimethyl terephthalate process residues, and the like. As the polyether polyol, for example, an amino polyol obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to ethylenediamine, tolylenediamine, triethanolamine, a Mannich condensation product, or the like is preferable.

  When an aromatic polyester polyol and a polyether polyol are used in combination, 60 to 90 parts by weight of the aromatic polyester polyol and 40 to 10 parts by weight of the polyether polyol are contained with respect to 100 parts by weight of the total polyol component. It is preferable to do. If the content of the aromatic polyester polyol is less than 60 parts by weight, the flame retardant material in the exothermic test may fail, and if it exceeds 90 parts by weight, the tendency of the foam to be hardened is increased. The particularly preferred content of the aromatic polyester polyol is 70 to 80 parts by weight.

  Examples of the polyisocyanate component used in the present invention include polymethylene polyphenyl isocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,6-dimethyl-1, Examples include 3-phenylene diisocyanate, 4,4′-dibenzyl diisocyanate, 9,10-anthracene diisocyanate, 4,3′-dimethyl-4,4′-diphenyl diisocyanate, xylylene diphenylmethane diisocyanate, and the like. You may use individually or in combination of 2 or more types. The amount used is suitably 1.0 to 2.0 in terms of an NCO / OH equivalent ratio.

  In the method for producing a rigid polyurethane foam of the present invention, for example, a polyoxyalkylene-based foam stabilizer such as polyoxyalkylene alkyl ether, a silicone-based foam stabilizer such as organosiloxane, a compatibilizer such as oxyethylene alkylphenol, Additives commonly used in the production of rigid polyurethane foams such as flame retardants, thickeners, colorants, stabilizers, etc. may be used.

  Examples of the flame retardant include phosphoric esters such as trimethyl phosphate, triethyl phosphate, trischloropropyl phosphate, and the addition amount is preferably 20 to 40 parts by weight with respect to 100 parts by weight of the polyol. If it is less than 20 parts by weight, the flame retardant material by the exothermic test may be rejected. Phosphoric acid esters and the like have the effect of improving brittleness, which is a drawback of rigid polyurethane foams containing water as a foaming agent in order to impart plasticity to the urethane resin, and improving adhesion. The strength tends to decrease due to the conversion.

  The density of the rigid polyurethane foam obtained by the production method and composition of the present invention is preferably 20 to 40 kg / m 3. Such a low density is economical as a product.

The raw materials used in Examples 1 to 9 and Comparative Example 1 are shown below.
(Raw materials used)
[Polyol component]
Polyol A: Polyethylene terephthalate polyester polyol (hydroxyl value 110)
Polyol B: Mannich polyether polyol (hydroxyl value 315)
・ Foam stabilizer: Silicone foam stabilizer (trade name “L-5420” manufactured by Toray Dow Corning Co., Ltd.)
Catalyst 1: alkylated polyalkylene polyamine (trade name “TOYOCAT TT” manufactured by Tosoh Corporation)
Catalyst 2: quaternary ammonium salt (trade name “TOYOCAT TRX” manufactured by Tosoh Corporation)
Catalyst 3: Dimethylimidazole (trade name “TOYOCAT DMI” manufactured by Tosoh Corporation)
Catalyst 4: Triethylenediamine (trade name “TOYOCAT L33” manufactured by Tosoh Corporation)
Catalyst 5: N, N ′, N ″ -dimethylaminopropylhexahydrotriazine (trade name “Polycat 41” manufactured by Air Products Japan Co., Ltd.)
Flame retardant: Trischloropropyl phosphate (trade name “TMCPP” manufactured by Daihachi Chemical Co., Ltd.)
[Polyisocyanate component]
・ Polyisocyanate: Polymethylene polyphenyl isocyanate (NCO content 30%)

  In accordance with the formulation shown in Table 1, using a Graco Model FFF1600 foaming machine as the apparatus shown in FIG. 1, a polyol component, a polyisocyanate component, and carbon dioxide (with respect to the total of the polyol component and the polyisocyanate component, 1 0.5 wt.%) Was mixed and spray foamed onto a 12 mm thick plywood and a calcium plate to obtain a rigid polyurethane foam. The temperature and pressure in the heating hoses 6 and 16 of the polyol component and isocyanate component at this time were 50 ° C. and 7 MPa, respectively. Moreover, the unit of each numerical value of the polyol component of Table 1, and a polyisocyanate component is a weight part.

  About each obtained foam, density (kg / m3), closed cell rate (%), moisture permeability ng / (msPa), reactivity, workability, dimensional stability, adhesiveness are measured, The results are also shown in Table 1.

※１：フォームの収縮が起きたため、透湿率は測定不能。

* 1: Moisture permeability cannot be measured due to foam shrinkage.

Regarding density (kg / m3), closed cell rate (%), moisture permeability ng / (msPa), reactivity, workability, dimensional stability, adhesiveness, and storage stability, Measurement was made on a rigid polyurethane foam spray foamed to a thickness of 30 mm.
-The density (kg / m3) was measured by weighing a test piece of 70 mm x 70 mm x 20 mm.
-The closed cell ratio (%) was measured based on ASTM D2856.
-Moisture permeability (ng / (msPa)) was measured based on JIS A9526-2006.
-Reactivity is the foaming finish time (rise time) (seconds) after foaming after spray foaming, and spray foaming according to the formulation shown in Table 1 (immediately after blending), and Table 1. The polyol components blended according to the blending recipe described above were spray foamed after being left for 72 hours (after the acceleration test) in an environment of 60 ° C., and the rise time of each was measured. The rise time (seconds) after the acceleration test was set to “◯” when the delay time was less than 30%, and “X” when the delay time was 30% or more with respect to the rise time immediately after blending.
-The workability ("horizontal spread" and "stickiness") was observed during spray foaming.
・ ・ When horizontal foam was sprayed on the plywood, it was judged as “O” if there was no foam protruding on all four sides of the plywood board, and “X” if there was lateral foam.
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The dimensional stability at high temperature was determined by leaving a test piece of 70 mm × 70 mm × 20 mm at 100 ° C. for 48 hours, and then examining whether or not there was any deformation.
-Dimensional stability at low temperature was determined by leaving a 70 mm × 70 mm × 20 mm test piece at −20 ° C. for 48 hours, and then checking for deformation, “no good”, and “no”.
-Adhesiveness was measured based on JIS A9526-2006, and peel strength of 80 kpa or more was "◯", and less than 80 kpa was "x".

  The method and composition for producing a rigid polyurethane foam of the present invention can be widely used as a method and composition for producing a heat insulating material for a house, a refrigerator, or the like.

DESCRIPTION OF SYMBOLS 1 Polyisocyanate component 2 Polyisocyanate component tank 3 Metering pump 4 Piping 5 Heater 6 Heating hose 7 Carbon dioxide cylinder in liquid state 8 Metering pump 9 Piping 10 Mixing head 11 Polyol component 12 Polyol component tank 13 Metering pump 14 Piping 15 Heater 16 Heating hose

Claims (4)

As a blowing agent, carbon dioxide generated by the reaction of water and a polyisocyanate component and carbon dioxide in at least one of a supercritical state, a subcritical state, and a liquid state are used in combination, and the water is preliminarily polyol. A rigid polyurethane foam can be obtained by adding carbon dioxide in a liquid state to the polyol component being transferred in a flow path leading to the mixing head before mixing the polyisocyanate component and the polyol component in the mixing head. A method of manufacturing comprising:
The method for producing a rigid polyurethane foam, wherein the polyol component contains at least four kinds of alkylated polyalkylene polyamine, quaternary ammonium salt, dimethylimidazole, and triethylenediamine as a catalyst.   1 to 6 parts by weight of alkylated polyalkylene polyamine, 2 to 5 parts by weight of quaternary ammonium salt, 2 to 6 parts by weight of dimethylimidazole, and 2 to 6 of triethylenediamine with respect to 100 parts by weight of polyol in the polyol component. 2. The method for producing a rigid polyurethane foam according to claim 1, further comprising parts by weight. As a blowing agent, carbon dioxide generated by the reaction of water and a polyisocyanate component and carbon dioxide in at least one of a supercritical state, a subcritical state, and a liquid state are used in combination, and the water is preliminarily polyol. A rigid polyurethane foam can be obtained by adding carbon dioxide in a liquid state to the polyol component being transferred in a flow path leading to the mixing head before mixing the polyisocyanate component and the polyol component in the mixing head. A rigid polyurethane foam composition for obtaining
A rigid polyurethane foam composition comprising at least four alkylated polyalkylene polyamines, quaternary ammonium salts, dimethylimidazole, and triethylenediamine as a catalyst in the polyol component.   1 to 6 parts by weight of alkylated polyalkylene polyamine, 2 to 5 parts by weight of quaternary ammonium salt, 2 to 6 parts by weight of dimethylimidazole, and 2 to 6 of triethylenediamine with respect to 100 parts by weight of polyol in the polyol component. The rigid polyurethane foam composition according to claim 3, wherein the rigid polyurethane foam composition is contained in parts by weight.

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