JP2014169357A - Polyurethane foam manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a hard polyurethane foam enabling a long-term storage of urethane raw ingredients and capable, even in a case where the addition of a third component has become problematic, of prompting the progress of an application work.SOLUTION: In a manufacturing method of a hard polyurethane foam for mixing and expanding: an isocyanate component including a polyisocyanate as a main component; and a polyol component including at least a polyester polyol, a foaming agent, a foam stabilizer, and a metallic catalyst, the polyol component comprises a weak amine catalyst having a pH value lower than 10.5. A third component liquid including at least a strong amine catalyst having a pH value higher than that of the weak amine catalyst is added during the transport of the isocyanate component and/or polyol component.

Description

  The present invention relates to a method for producing a rigid polyurethane foam, and more particularly to a method for producing a rigid polyurethane foam by using water as a foaming agent.

  A rigid polyurethane foam is produced by reacting an active hydrogen-containing compound containing two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group and a polyisocyanate compound in the presence of a foam stabilizer, a catalyst and a foaming agent. Things are widely done.

  The rigid polyurethane-based foam has excellent low-temperature insulation properties, moldability, self-adhesiveness, cushioning properties, etc., such as structures such as houses, refrigerator / freezer warehouses, tanks for LPG tankers, vending machines, refrigerators, automobile parts, etc. Widely used in applications.

  In the production of these rigid polyurethane foams, hydrochlorofluorocarbon (HCFC) has been used as a main foaming agent, but since this has an action of destroying the ozone layer, in recent years, hydrofluorocarbon (HFC) has been used. Is currently used, but this also acts as a greenhouse gas due to the problem of global warming, and it is obliged to reduce it.

  In order to reduce hydrofluorocarbons (HFCs), the technology that uses water as a blowing agent is regarded as important. However, since it is difficult to achieve the desired performance with water alone, the proportion of water is increased to increase hydrofluorocarbons (HFCs). ) To minimize environmental and economic burdens.

  In addition, when water is used as a blowing agent, in order to improve combustion performance, ester-based materials such as ester polyols and flame-retardant phosphates are generally used in combination to increase flame retardancy. These have the problem that ester hydrolysis proceeds in the presence of water and an amine catalyst, resulting in degradation.

  In order to solve this problem, various methods are known. For example, Patent Document 1 uses a method in which an amine-based catalyst is post-added, and Patent Document 2 employs a method in which water is post-added, thereby suppressing decomposition of the ester-based material.

JP 2009-35628 A JP 2005-105157 A

  However, the amine-based catalyst has a property that the decomposition period of the ester varies depending on the component. In general, when the pH value of the amine catalyst is high, the catalytic effect is strong and the decomposition period of the ester material is shortened, and when it is low, the catalytic effect is weak and the decomposition period of the ester material is extended. For this reason, by using an amine catalyst having a low pH value, it is possible to extend the material, but the catalytic effect is small, and it is necessary to increase the addition amount of the catalyst. In addition, the amine-based catalyst is a relatively expensive material, and there is a problem that the use of a large amount leads to an increase in cost.

  In addition, the third component addition equipment has a smaller capacity and parts are considerably smaller than the equipment for the two-component main raw material, and the equipment using the urethane stock solution performs spray spraying at a high pressure of 5 to 10 MPa. When the failure of the third component addition equipment occurs, there is a problem that urethane cannot be sprayed. Urethane insulation work is usually required to be completed and completed immediately after the deadline is reached, and there is an environment where equipment must be repaired and dealt with immediately even if the equipment breaks down. However, it is actually difficult to repair the equipment failure during the day and complete the construction process, and there is a problem that it often affects the post-process, such as a delay in construction.

  Therefore, the technical problem to be solved by the present invention is a rigid polyurethane foam that enables long-term storage stability of the urethane raw material and can proceed with the construction process even when there is a problem with the addition of the third component. It is to provide a manufacturing method.

  In order to solve the above technical problem, the present invention provides a method for producing a rigid polyurethane foam having the following constitution.

According to the first aspect of the present invention, a rigid polyurethane foam in which an isocyanate-based component mainly composed of polyisocyanate and a polyol-based component containing at least a polyester-based polyol, a foaming agent, a foam stabilizer, and a metal-based catalyst are mixed and foamed. A manufacturing method of
The polyol component contains a weak amine catalyst having a pH value lower than 10.5,
A polyurethane foam production characterized by mixing a third component liquid containing at least a strong amine catalyst having a pH value larger than that of the weak amine catalyst during feeding of the isocyanate component and / or polyol component. Provide a method.

  Each said structure WHEREIN: It is preferable that the said foaming agent contains water at least.

  In each of the above configurations, the strong amine catalyst contained in the third component liquid preferably has a pH of 10.5 or more.

  In each of the above configurations, it is preferable that the third component includes at least a flame retardant together with the strong amine catalyst.

  According to the present invention, by using a weak amine catalyst having a pH value of less than 10.5 in the polyol component, the progress of degradation of the polyol component can be delayed, and a strong amine compound is used as the third component. By post-adding the catalyst, the reactivity with the isocyanate component and the workability can be improved. In addition, since a weak amine catalyst is blended in advance in the polyol component, the reactivity of the urethane can be promoted even when the strong amine catalyst cannot be added after any reason. Can proceed.

  Therefore, the long-term storage stability of the urethane raw material is made possible, and the construction process can proceed even when a problem occurs in the addition of the third component.

It is a figure which shows typically the structure of the manufacturing apparatus used for the polyurethane foam manufacturing method concerning embodiment of this invention.

  Hereinafter, the manufacturing method of the rigid polyurethane foam which concerns on one Embodiment of this invention is demonstrated, referring drawings. The method for producing a rigid polyurethane foam according to an embodiment of the present invention relates to the production of a rigid polyurethane-based foam. For the purpose of solving the problem of long-term storage stability of a urethane raw material, particularly a polyol component, at that time. Yes.

  The method for producing a rigid polyurethane foam according to this embodiment is a method for producing a rigid polyurethane foam in which an isocyanate-based component containing polyisocyanate and a polyol-based component containing a polyester polyol are mixed and foamed, and the polyol-based component Includes a weak amine catalyst having a pH value of less than 10.5, and a strong amine having at least a pH value higher than that of the weak amine catalyst during the feeding of the isocyanate component and / or the polyol component. A third component liquid containing an amine-based catalyst including a system catalyst is mixed.

  In the manufacturing method of the rigid polyurethane foam according to the present embodiment, since the manufacturing method of spray foam mainly based on in-situ foaming is used as a basis, a spray machine suitable for in-situ use is used. However, ester compounds such as ester polyols blended by using water as a foaming agent have a problem that ester hydrolysis proceeds in the presence of an amine catalyst and the quality deteriorates. On the other hand, when an amine-based catalyst is added later as the third component, there is a problem that the construction process is stagnant when equipment such as a spray machine breaks down.

  Furthermore, the on-site foaming concentrate is used outdoors in the seasonal environment throughout Japan, and the amount of amine is adjusted at the manufacturing plant in accordance with changes in the environment (temperature). The timing is difficult, and it is not economical, such as “the number of product numbers increases, the number of inventory increases, and the past seasons cannot be used”.

  However, this rigid polyurethane foam manufacturing method uses a method in which a third component containing a strong amine is added in accordance with the on-site environment, so that a polyol component containing a weak amine is fixed and added in the field. On the other hand, even if the equipment breaks down, the polyol component contains weak amine, so the workability is reduced, but it is possible to proceed with the work. Become.

  The isocyanate component is mainly composed of polyisocyanate, and as polyisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or these polyisocyanates are reacted with polyol. Alternatively, carbodiimidized modified products and mixtures thereof are used. Diphenylmethane diisocyanate (crude MDI, C-MDI, polymeric MDI, etc.) is preferable.

  In addition to the polyester-based polyol, the polyol-based component usually includes water as a foaming agent, a foam stabilizer, a metal-based catalyst, a flame retardant, and the like. Moreover, the weak amine catalyst whose pH value is smaller than 10.5 is mix | blended.

  Polyols can be used alone or in combination of polyester polyols and polyether polyols. Examples of polyester polyols include polyhydric alcohol-polycarboxylic acid condensation polyester polyols and cyclic ester ring-opening polymer polyester polyols. In this case, polyhydric alcohols include ethylene glycol and propylene glycol. , Diethylene glycol, dipropylene glycol, butanediol, hexanediol, trimethylolpropane, methylpropanediol, etc., and carboxylic acids include succinic acid, adipic acid, sebacic acid, maleic acid, phthalic anhydride, isophthalic acid, terephthalic acid Examples of the ring-opening system include polyester-based polyols obtained by ring-opening addition polymerization of ε-caprolactone to glycol.

  Further, it contains 2 to 8 hydroxyl groups obtained by adding an alkylene oxide such as ethylene oxide and propylene oxide to a polyfunctional amino group-containing compound such as ethylenediamine, tolylenediamine, and diaminotoluene, and an average hydroxyl value is about 20 to 4000. Polyether polyols obtained by polymerizing vinyl polyether-containing compounds with these polyether polyols or the like are mainly used for in-situ foaming, so that it is desired to instantly foam and cure. In addition to the above, it is also possible to include a polyether-based polyol using a highly active compound such as ethylenediamine as an initiator.

  As the foaming agent, at least water is used as the foaming agent. However, since it may be difficult to achieve desired performance with water alone, it is preferable to use a foaming agent other than water as the foaming agent. Examples of the blowing agent used in combination include hydrocarbons such as pentane and hexane, carbon dioxide (liquefied carbon dioxide), fluorine-based compounds such as HFC-245fa, HFC-365mfc, and HFC-134a. In addition, about a fluorine-type compound, what is called a fluorine-type compound with a low global warming potential (GWP) is preferable, and even if it is a fluorine-type compound with a low GWP even if it is other than the fluorine-type compound illustrated above, it is preferably used together with water. can do. This is very useful in terms of environment. Moreover, these foaming agents can be used individually or in combination of 2 or more.

  As foam stabilizers, silicone surfactants such as organopolysiloxanes, organopolysiloxane / polyalkylene copolymers, and polyalkenylsiloxanes having polyalkylene side chains are generally used for soft slabs, soft molds and rigid foams. An agent is preferably used.

  As the metal catalyst, a tin catalyst or a lead catalyst can be used. Examples of the tin-based catalyst include dibutyltin dilaurate and stannous octate. Examples of the lead-based catalyst include lead octylate. Examples of the potassium salt catalyst include potassium acetate and potassium octylate.

  Examples of the flame retardant include trischloropropyl phosphate. Furthermore, auxiliary agents such as a thickener, an antioxidant, and a colorant can be used for the polyol component.

  Examples of the weak amine catalyst include N, N-dicyclohexylmethylamine. The amount of the weak amine catalyst is preferably an amount that allows spraying treatment without the third component, assuming that a problem occurs in the addition of the third component. The specific blending amount varies depending on the use environment and the like, but is generally 1 to 6 parts by weight, particularly preferably 2 to 5 parts by weight with respect to 100 parts by weight of the polyol component.

  The third component is mixed during the feeding of the isocyanate component and / or the polyol component, and contains a strong amine catalyst.

  The strong amine catalyst is a catalyst having a pH value larger than that of the weak amine catalyst. Specifically, the strong amine catalyst is an amine catalyst having a pH value of 10.5 or more.

  Examples of the strong amine catalyst include triethylenediamine, N, N-dimethylcyclohexylamine (DMCHA), N, N ′, N ″ -dimethylaminopropylhexahydrotriazine, N, N, N′-trimethylaminoethylethanolamine, N, N, N ′, N ′, N ″ -pentamethyldiethylenetriamine (PMDETA), N, N, N ′, N′-tetramethyl-1,6-hexanediamine (TMHDA) and the like can be mentioned.

  Since a strong amine catalyst has a low viscosity when added as it is, it is preferably diluted to adjust the viscosity. Examples of the diluent include a low viscosity (300 to 700 mPa · s: temperature 25 ° C.) polyether polyol and an organic phosphorus compound in which an addition error does not greatly affect the reaction. In particular, “trischloropropyl phosphate (TCPP), which is used as a flame retardant or a plasticizer, is most preferable as a diluent. The diluent is, for example, a blending amount enough to dilute a strong amine catalyst to about 2 times. It is preferable.

Assuming that there is a problem with the addition of the third component, the diluent may be blended with the polyol component or the isocyanate component in an amount of a flame retardant that can maintain flammability even without the third component. preferable. Specifically, even in the absence of the third component, in the exothermic test (ISO 5660 Part1 exothermic test method: corn calorimeter method) required as a flame retardant material in the fire prevention material category, (1) heating (heating (5 minutes) The total calorific value after the end is 8 MJ / m ² or less, (2) The maximum heat generation rate does not exceed 200 kW / m ² continuously for 10 seconds or more until the end of heating, (3) Until the end of heating, it is preferable to add a flame retardant satisfying the condition that there are no cracks and holes penetrating to the back side, which is harmful to fire prevention, in the polyol component or the isocyanate component.

  The third component may be mixed with an adipic acid-based or phthalic acid-based plasticizer in addition to the above materials.

  Next, an apparatus for producing a rigid polyurethane foam will be described with reference to FIG.

  Drawing 1 is a figure showing typically composition of a manufacturing device used for a polyurethane foam manufacturing method concerning an embodiment of the present invention. The polyurethane foam manufacturing apparatus 1 according to the present embodiment shown in FIG. 1 shows a case where the third component is supplied to the polyol-based component, and the third component liquid stored in the third component container 10 and It is a device that conveys the isocyanate component while heating it using the heater 3 and the hose heater 4, and mixes and discharges it within the spray gun 5.

  As shown in FIG. 1, the polyurethane foam manufacturing apparatus 1 includes a third component container 10, a polyol component storage container 20 that stores a polyol-based component, and a polyisocyanate component storage container 30 that stores an isocyanate-based component, The third component pipe L11 that conveys the third component, the polyol pipe L12 that conveys the polyol-based component, and the isocyanate pipe L13 that conveys the isocyanate-based component communicate with the discharge device 2.

  The third component pipe L11 for conveying the third component is connected to the connector 12 of the third component container 10, and a third component pump 11 is provided in the middle, and the mixing provided in the polyol pipe L12. Connected to the device 22. The third component pipe L11 may be provided with a needle valve (not shown) for adjusting the flow rate of the third component. The third component pipe L11 has a check valve that regulates the flow direction of liquefied carbon dioxide so that the polyol component in the polyol pipe L12 communicating with the mixer 22 does not flow into the third component pipe L11. Can also be provided.

  The polyol pipe L12 includes a polyol pump 21 and a mixer 22, and communicates with the spray gun 5 of the discharge device. The isocyanate pipe L13 includes an isocyanate pump 31 and communicates with the spray gun 5 of the discharge device. The polyol-based component and the isocyanate-based component are fed to the spray gun 5 through the polyol piping L12 and the isocyanate piping L13 at pressures pressurized by the pumps 21, 31, respectively. The spray gun 5 mixes the isocyanate-based component fed by the isocyanate piping L13 and the polyol piping L12 and the polyol-based component mixed with the third component, and discharges them from the discharge port.

  The isocyanate pipe L13 and the polyol pipe L12 are provided with a heater 3 and a hose heater 4, and the reaction conditions are stabilized by heating the supplied liquid and keeping the temperature constant. In addition, the reactivity at the time of discharge from the spray gun 5 can be enhanced.

  In the example of FIG. 1, the third component is configured to be mixed with the polyol-based component, but may be configured to be mixed with the isocyanate-based component or configured to be mixed with both. It may be.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and the like. Evaluation using the following isocyanate-based components and polyol-based components and the addition of an amine-based catalyst or the polyol component was performed using Examples and Comparative Examples shown in Table 1 below. The raw materials used in these examples and comparative examples are as follows.

(1) Isocyanate component Isocyanate: Polymethylene polyphenyl polyisocyanate (2) Polyol component Polyol A: Polyester polyol (OHV = 250)
Polyol B: Polyether polyol (OHV = 450)
Flame retardant: Trischloropropyl phosphate (TCPP)
Foam stabilizer: Silicone foam stabilizer Metal-based catalyst: Potassium octylate Metal-based catalyst: Lead octylate Foaming agent: Water (3) Amine-based catalyst Catalyst A (weak amine-based catalyst): Dimethylaminoethoxyethanolamine Catalyst B (strong) Amine-based catalyst): Tris (dimethylaminopropyl) hexahydro-S-triazine Catalyst C (strong amine-based catalyst): Triethylenediamine 33% DPG solution

  In addition, the composition of catalyst B and catalyst C (each diluted with TCPP) blended in Examples 1 and 2 shown in parentheses of the blend shown in Table 1 is the third component immediately before foaming using the production apparatus shown in FIG. As a polyol component.

(Reactivity evaluation)
After mixing and stirring the two liquids of the polyol component and the isocyanate component by hand foaming, the foaming rise start time (cream time) and the rise end time (rise time) were measured.

  Regarding Example 1 and Example 2, even after the material was left for one month, neither cream time nor rise time changed so much, and it was found that the degree of deterioration of the raw material was low. On the other hand, in Comparative Examples 1 and 2 in which a strong amine catalyst was blended in advance on the polyol side, the reactivity evaluation after standing for 1 month was low, and deterioration of the material was observed. In addition, in Comparative Example 3 in which the ratio of the metal catalyst was increased instead of the amine catalyst and in Comparative Example 4 in which the weak amine catalyst was preliminarily blended on the polyol side, the reactivity evaluation value was found not to deteriorate so much. did.

(Evaluation of workability)
In a F1600 type spray foaming machine, a layer of 30 mm was sprayed onto a concrete plate, and the surface condition and lateral elongation were evaluated. In the evaluation of the surface condition, “◯” was given when the reaction was fast and the surface was smooth, “x” was given when the reaction was slow and the surface was uneven, and “Δ” was the middle of these. In the evaluation of the lateral elongation, “×” indicates that the lateral elongation is largely peeled off, and “Δ” indicates an acceptable level although there is lateral elongation.

  Regarding Example 1 and Example 2, it was found that both the surface condition and the evaluation of the lateral elongation were good even when the aged raw material was used. On the other hand, for Comparative Examples 1 and 2, the workability when using an aged material deteriorated. Moreover, about the comparative example 3, it turned out that sufficient foaming was not confirmed but evaluation of lateral elongation was bad. In Comparative Example 4, the lateral elongation and the surface state were Δ levels. Although construction similar to the example cannot be performed, it has been found that construction efficiency is somehow possible, although the construction efficiency is extremely deteriorated by making the bottom blowing construction, making the thickness per layer thin, and the like. The urethane foam of Comparative Example 4 also satisfied the conditions (1) to (3) described above in the exothermic test (ISO 5660 Part 1 exothermic test method: corn calorimeter method).

  As described above, according to the method for producing polyurethane foam according to the present embodiment, by using a weak amine catalyst having a pH value smaller than 10.5 in the polyol component, the progress of deterioration of the polyol component is delayed. In addition to the addition of a strong amine catalyst as the third component, the reactivity with the isocyanate component and the workability can be improved. In addition, since a weak amine catalyst is blended in advance in the polyol component, the reactivity of the urethane can be promoted even when the strong amine catalyst cannot be added after any reason. Can proceed.

  In addition, this invention is not limited to the said embodiment, It can implement in another various aspect.

DESCRIPTION OF SYMBOLS 1 Polyurethane foam manufacturing apparatus 2 Discharge apparatus 3 Heating machine 4 Hose heater 5 Spray gun 10 3rd component container 11 3rd component pump 12 Connector 20 Polyol component storage container 21 Polyol pump 22 Mixer 30 Polyisocyanate component storage container 31 Isocyanate pump L11 Third component piping L12 Polyol piping L13 Isocyanate piping

Claims (4)

A method for producing a rigid polyurethane foam comprising mixing and foaming an isocyanate-based component containing polyisocyanate as a main component and a polyol-based component containing at least a polyester-based polyol, a foaming agent, a foam stabilizer, and a metal catalyst,
The polyol component contains a weak amine catalyst having a pH value lower than 10.5,
A polyurethane foam production characterized by mixing a third component liquid containing at least a strong amine catalyst having a pH value larger than that of the weak amine catalyst during feeding of the isocyanate component and / or polyol component. Method.   The method for producing a polyurethane foam according to claim 1, wherein the foaming agent contains at least water.   The method for producing a polyurethane foam according to claim 1 or 2, wherein the strong amine catalyst contained in the third component liquid has a pH of 10.5 or more.   The polyurethane foam production method according to any one of claims 1 to 3, wherein the third component includes at least a flame retardant together with the strong amine catalyst.

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