JP2006328172A - Polyol composition for spray foamed rigid polyurethane foam and method for producing spray foamed rigid polyurethane foam - Google Patents

Abstract

[PROBLEMS] To provide a polyol composition for a rigid polyurethane foam having water as a foaming agent and having a low density and no problem in work, and a method for producing a rigid polyurethane foam using the polyol composition.
SOLUTION: A polyol compound, water as a foaming agent, a foam stabilizer, and a catalyst are mixed with a polyisocyanate component by a spray device and reacted to form a rigid polyurethane foam. - dialkyl alkanolamines and N, and N- dimethyl propylene diamine _{((CH 3) 2 N (} CH 2) 3 NH 2) is intended to include a spray foamed rigid polyurethane foam polyol composition.
[Selection figure] None

Description

  The present invention relates to a polyol composition for spray foamed rigid polyurethane foam using water as a foaming agent, and a method for producing a rigid polyurethane foam using the polyol composition.

  Conventionally, glass wool has been the most commonly used heat insulating material for buildings mainly in detached houses, but glass wool installed in the wall gradually sinks downward over the years, and the heat insulation of the wall In addition, there is a problem that the construction thickness becomes thick in order to satisfy the heat insulation performance of the heat insulation grade 4 grade.

  Rigid polyurethane foam is a well-known material as a heat insulating material, a lightweight structural material, etc., and is also used as a heat insulating material for a detached house. Conventionally, the rigid polyurethane foam used as a heat insulating material for a detached house has been manufactured as a panel, and has a high density and a high cost. Therefore, it has been necessary to cut the construction.

As a rigid polyurethane foam that does not require cutting, a water-foamed spray-type rigid polyurethane foam that is often applied to an outdoor structure is known (for example, Patent Document 1). However, the spray-type water-foamed rigid polyurethane foam disclosed in Patent Document 1 has a density of 25 kg / m ³ or more and does not satisfy the demand for low density and low cost. Further, in the technique disclosed in Patent Document 1, when the density is reduced by simply increasing the amount of the foaming agent, there arises a problem that the foam shrinks.

  As a low-density rigid polyurethane foam, a technique in which a polyether polyol having a hydroxyl value of 200 to 300 and a polyether polyol having a hydroxyl value of 400 to 900 are used in combination and an isocyanate index is set to 30 to 65 is known (Patent Document 2). ).

Japanese Patent Laid-Open No. 2001-40054 JP 2004-91643 A

  However, the technique described in Patent Document 2 is not suitable for spray foaming that requires a quick reaction, and is a rigid polyurethane foam such as tetramethylhexamethylenediamine as used in the Examples of Patent Document 1. If the reaction rate is increased by means such as diverting the catalyst for use or increasing the amount of the catalyst used in Patent Document 2, the spraying is applied to the inner surface of the outer wall of a detached house. When construction is performed in a closed space, the worker may develop a temporary eye disorder called so-called amine rainbow, which is not preferable in terms of the work environment and needs to be improved.

  The present invention has been made in view of the above-mentioned problems of the known art. A polyol composition for rigid polyurethane foam, which uses water as a foaming agent and has a low density and has no operational problems, and a method for producing a rigid polyurethane foam using the polyol composition Is intended to provide.

The polyol composition for spray foamed rigid polyurethane foam of the present invention contains a polyol compound, water as a foaming agent, a foam stabilizer and a catalyst, and is mixed with a polyisocyanate component by a spray device and reacted to form a rigid polyurethane foam. Is,
The catalyst includes N, N-dialkylalkanolamine and N, N-dimethylpropylenediamine ((CH ₃ ) ₂ N (CH ₂ ) ₃ NH ₂ ).

  The polyol composition using the catalyst having the above constitution is a polyol composition for rigid polyurethane foam which uses water as a foaming agent and has a low density and has no operational problems in spraying.

N, N-dialkylalkanolamines have the general formula R ₁ R ₂ N—X—OH
It is a compound represented by these. R ₁ and R ₂ are the same or different C1-C4 alkyl groups, and X is a C2-C4 alkylene group. R ₁ and R ₂ are preferably a methyl group or an ethyl group, X is preferably an ethylene group, and use of dimethylethanolamine is particularly preferable.

Another aspect of the present invention is a rigid polyurethane foam for spray foaming, which is prepared by mixing a polyol composition containing a polyol compound, water as a foaming agent, a foam stabilizer and a catalyst with a polyisocyanate component, and reacting them to form a rigid polyurethane foam. A manufacturing method of
The catalyst includes N, N-dialkylalkanolamine and N, N-dimethylpropylenediamine ((CH ₃ ) ₂ N (CH ₂ ) ₃ NH ₂ ).

  With the above configuration, water can be used as a foaming agent, and the rigid polyurethane foam can be applied to the inner surface of the outer wall of a detached house by spraying without causing problems such as amine rainbow.

In the method for producing the spray foamed rigid polyurethane foam, the foam density is preferably 15 kg / m ³ or less.

By setting the foam density to 15 kg / m ³ or less, a low-cost rigid polyurethane foam suitable for heat insulation of a detached house can be produced. The foam density can be adjusted mainly by the amount of water, which is a foaming agent. The amount of water added to achieve the foam density is 10 to 40 parts by weight, more preferably 15 to 30 parts by weight, based on 100 parts by weight of the total amount of the polyol compound. Rigid polyurethane foam with a foam density of less than 10 is difficult to manufacture.

  In the method for producing the spray foamed rigid polyurethane foam, it is preferable that the closed cell ratio of the foam is 15% or less.

  By setting the closed cell ratio of the foam to 15% or less, the shrinkage of the foam can be effectively prevented. The closed cell ratio of the foam can be adjusted mainly by selecting the type of polyol compound and the type of foam stabilizer used.

  The polyol composition of the present invention contains a polyol compound, water as a foaming agent, a foam stabilizer and a catalyst. The viscosity of the polyol composition of the present invention is preferably 1000 mPa · s (20 ° C.) or less, and preferably 500 mPa · s (20 ° C.) or less, from the viewpoint of easily producing a rigid polyurethane foam by a spray method. More preferably, it is more preferably 400 mPa · s or less.

  The polyol compound which comprises the polyol composition of this invention can use the well-known polyol compound for spray foaming rigid polyurethane foams without limitation. Specific examples include polyether polyols, aromatic ester polyols and Mannich polyols having a hydroxyl value of 200 to 600 mgKOH / g. Examples of polyether polyols include aliphatic polyether polyols, aromatic polyether polyols, aromatic amine polyols, and aliphatic amine polyols.

  The aliphatic polyether polyol is a polyol compound obtained by ring-opening addition of propylene oxide and ethylene oxide, preferably a cyclic ether compound such as ethylene oxide, propylene oxide, butylene oxide or the like, using low molecular weight polyhydric alcohol as an initiator. It is.

  Examples of the low molecular weight polyhydric alcohol that is an initiator include glycols such as ethylene glycol and 1,4-butanediol, triols such as trimethylolpropane and glycerin, tetrafunctional alcohols such as pentaerythritol, sorbitol, sucrose, etc. Hexafunctional or higher polyhydric alcohols, water and the like are exemplified. Examples of polyether polyol compounds using glycerin as an initiator include commercially available products such as EX-880 and EX-813 (Asahi Glass).

  The aromatic polyether polyol is produced in the same manner as the above aliphatic polyether polyol using an aromatic compound such as hydroquinone, bisphenol A, and xylylene glycol as an initiator.

  Examples of the aliphatic amine polyol include alkylene diamine polyols and alkanol amine polyols. These polyol compounds are polyfunctional polyol compounds having a terminal hydroxyl group obtained by ring-opening addition of at least one of ethylene oxide and propylene oxide using alkylene diamine or alkanol amine as an initiator. As the alkylene diamine, known compounds can be used without limitation. Specifically, use of alkylene diamine having 2 to 8 carbon atoms such as ethylene diamine, propylene diamine, butylene diamine, hexamethylene diamine, and neopentyl diamine is preferable. Among these, the use of alkylenediamine having a small number of carbon atoms is more preferable, and the use of a polyol compound having ethylenediamine or propylenediamine as an initiator is particularly preferable. In the alkylene diamine-based polyol, the alkylene diamine as the initiator may be used alone or in combination of two or more. Examples of the alkanolamine include monoethanolamine, diethanolamine, and triethanolamine. The number of functional groups of the polyol compound using alkylene diamine as the initiator is 4, and the number of functional groups of the polyol compound using alkanolamine as the initiator is 3.

  The aromatic amine-based polyol is a polyfunctional polyether polyol compound having a terminal hydroxyl group obtained by ring-opening addition of at least one of ethylene oxide and propylene oxide using an aromatic diamine as an initiator. As the initiator, known aromatic diamines can be used without limitation. Specific examples include 2,4-toluenediamine, 2,6-toluenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane, p-phenylenediamine, o-phenylenediamine, naphthalenediamine and the like. Of these, the use of toluenediamine (2,4-toluenediamine, 2,6-toluenediamine or a mixture thereof) is particularly preferred in that the obtained rigid polyurethane foam has excellent properties such as heat insulation and strength.

  The aromatic ester polyol is an ester polyol of a glycol such as ethylene glycol, diethylene glycol, 1,6-hexanediol and an aromatic dicarboxylic acid.

  Mannich polyol is obtained by subjecting an active hydrogen compound obtained by the Mannich reaction of phenol and / or its alkyl-substituted derivative, formaldehyde and alkanolamine, or ring-opening addition polymerization of at least one of ethylene oxide and propylene oxide to this compound. Active hydrogen chemical. Examples of such a commercially available polyol compound include DK-3773 and 3810 (Daiichi Kogyo Seiyaku), which can be used.

  You may use a crosslinking agent as a component which comprises the polyol composition for rigid polyurethane foams of this invention. As the crosslinking agent, low molecular weight polyhydric alcohols used in the technical field of polyurethane can be used. Specifically, trimethylolpropane, glycerin, pentaerythritol, triethanolamine and the like are exemplified.

  The polyisocyanate compound that forms a rigid polyurethane foam by mixing and reacting with the polyol composition is easy to handle, fast in reaction, excellent in the physical properties of the resulting rigid polyurethane foam, and low in cost. For this reason, liquid MDI is used. As liquid MDI, Crude MDI (c-MDI) (Sumijoule 44V-10, Sumijoule 44V-20, Sumijoule H-420, etc. (manufactured by Sumika Bayer Urethane Co., Ltd.), Millionate MR-200 (Nippon Polyurethane Industry)) Uretonimine-containing MDI (Millionate MTL; manufactured by Nippon Polyurethane Industry) and the like are used. In addition to liquid MDI, other polyisocyanate compounds may be used in combination. As the polyisocyanate compound used in combination, a polyisocyanate compound known in the technical field of polyurethane can be used without limitation.

  In the production of the rigid polyurethane foam of the present invention, in addition to the above components, catalysts, flame retardants, colorants, antioxidants and the like well known to those skilled in the art can be used.

  As the catalyst, in addition to the above-mentioned two kinds of catalysts, the reactivity may be adjusted by adding another catalyst for rigid polyurethane foam to an extent that does not cause a problem in operation. Specifically, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine (Kaorizer No. 1), N, N, N ′, N ′, N-alkylpolyalkylenepolyamines such as N ″ -pentamethyldiethylenetriamine (Kaorizer No. 3), diazabicycloundecene (DBU), bis (β-dimethylaminoethyl) ether (NIAX-A1; Union Carbide Japan), etc. It is preferable to use a tertiary amine catalyst.

  In the present invention, addition of a flame retardant is also a preferred embodiment, and examples of suitable flame retardants include metal compounds such as halogen-containing compounds, organophosphates, antimony trioxide, and aluminum hydroxide. .

  Organophosphates are suitable additives because they also have an action as a plasticizer and thus have an effect of improving the brittleness of rigid polyurethane foam. It also has the effect of reducing the viscosity of the polyol composition. Examples of the organic phosphate esters include halogenated alkyl esters of phosphoric acid, alkyl phosphate esters, aryl phosphate esters, phosphonate esters, and the like. Specifically, tris (β-chloroethyl) phosphate (CLP, Daihachi Chemical), Tris (β-chloropropyl) phosphate (TMCPP, Daihachi Chemical), Tributoxyethyl phosphate (TBXP, Daihachi Chemical), Tributyl phosphate, Triethyl phosphate, Cresyl phenyl phosphate, Dimethyl methylphosphonate Etc., and one or more of these can be used. The addition amount of the organic phosphates is 50 parts by weight or less, preferably 10 to 50 parts by weight, based on 100 parts by weight of the total polyol compound. If this range is exceeded, problems such as insufficient plasticization and flame retardant effects and deterioration of the mechanical properties of the foam may occur.

  As the foam stabilizer, a known foam stabilizer for rigid polyurethane foam having a closed cell ratio of 15% or less, more preferably 10% or less is selected and used. In the present invention, use of SH190, SH-192, SH-193, SH-194 (Toray Dow Corning Silicon) is preferable.

  In the method for producing a rigid polyurethane foam, the isocyanate group / active hydrogen group equivalent ratio (NCO index) in the mixing of the polyol composition and the polyisocyanate component is 0.4 to 0.8, more preferably 0.5. ~ 0.6.

  With such a configuration, it is possible to produce a rigid polyurethane foam in which many isocyanurate bonds are formed in the resin constituting the rigid polyurethane foam and the flame retardancy is further improved.

(Polyol composition)
A polyol composition was prepared with the composition described in the upper part of Table 1. The contents and characteristics of the raw materials used are as follows.
a) Polyol compound Polyether polyol using glycerin as an initiator, hydroxyl value = 235 mgKOH / g, viscosity = 750 mPa · sec (25 ° C .; Asahi Glass)
b) TMCPP: Phosphorus flame retardant (plasticizer) (Daihachi Chemical Industry)
c) Catalyst / Dimethylaminoethanol (Catalyst A)
・ N, N dimethylaminoethoxyethanol (Catalyst B)
Bis (β-dimethylaminoethyl) ether (NIAX-A1; Union Carbide Japan)
d) Foam stabilizer SH-192 (Toray Dow Corning Silicon)
e) Polyisocyanate component: Sumidur H-420 (Suika Bayer Urethane).

(Examples and comparative examples)
In Examples and Comparative Examples, a polyol composition was prepared by a conventional method with the formulation described in the upper part of Table 1. In the production of the rigid polyurethane foam, the polyol composition and the polyisocyanate component were mixed with a laboratory stirrer so that the isocyanate index (NCO / OH equivalent ratio) was 0.55. The evaluation described below was performed, and the results are shown in the lower part of Table 1.

(Evaluation)
1) Foam density (kg / m ³ )
A foam sample of 100 mm × 100 mm and thickness 100 mm was cut out from the core layer excluding the skin layer from the rigid polyurethane foam obtained by free foaming using a mold of 200 mm × 200 mm, depth 200 mm, and weighed. The density (kg / m ³ ) was calculated.

2) Workability evaluation Rigid polyurethane foam was applied to the wall surface of a space corresponding to one room of a detached house by the spray method, and sensory evaluation was performed by a panelist. The evaluation results were performed according to the following criteria.
A: There is no problem in work.
○: Some workers feel eye irritation.
Δ: Amine rainbow is generated during construction at high temperature and high humidity.
X: The working environment is poor.

  From the results in Table 1, it is clear that working problems are reduced when producing low density spray foamed rigid polyurethane foams using the polyol composition of the present invention.

Claims (4)

A polyol composition comprising a polyol compound, water as a blowing agent, a foam stabilizer and a catalyst, mixed with a polyisocyanate component by a spray device, and reacted to form a rigid polyurethane foam,
The polyol for spray foamed rigid polyurethane foam, characterized in that the catalyst contains N, N-dialkylalkanolamine and N, N-dimethylpropylenediamine ((CH ₃ ) ₂ N (CH ₂ ) ₃ NH ₂ ). Composition. A method for producing a rigid polyurethane foam comprising mixing a polyol composition containing a polyol compound, water as a foaming agent, a foam stabilizer and a catalyst with a polyisocyanate component and reacting the mixture to form a rigid polyurethane foam,
The catalyst comprises N, N-dialkylalkanolamine and N, N-dimethylpropylenediamine ((CH ₃ ) ₂ N (CH ₂ ) ₃ NH ₂ ). Method. The method for producing a spray-foamed rigid polyurethane foam according to claim 2, wherein the foam density is 15 kg / m ³ or less.   The method for producing a spray foamed rigid polyurethane foam according to claim 2 or 3, wherein the foam has a closed cell ratio of 15% or less.