JP2009114287A - Polyol composition for spray-foamed rigid polyurethane foam and process for manufacturing spray-foamed rigid polyurethane foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyol composition which uses water as a foaming agent, slightly affects a working environment, forms a rigid polyurethane foam having high flame retardancy and satisfactory friability, and prevents a foaming stock solution composition from sagging immediately after spray coating, and to provide a process for manufacturing the rigid polyurethane foam using the polyol composition. <P>SOLUTION: The polyol composition contains a polyol compound, water as a foaming agent, a foam stabilizer, a flame retardant, and a catalyst. The composition is mixed with a polyisocyanate component by using a spray apparatus and reacted with it to form a rigid polyurethane foam. The polyol compound consists of an aromatic ester polyol and a polyether polyol. The polyol composition also contains HFC-134a as an auxiliary foaming agent at a concentration of 0.5-5 wt.%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyol composition for spray foamed rigid polyurethane foam that forms a rigid polyurethane foam having high flame retardancy and good adhesion to a substrate, and a method for producing a rigid polyurethane foam using the polyol composition. Is.

  Rigid polyurethane foam is a well-known material as a heat insulating material, a lightweight structural material, and the like. Such a rigid polyurethane foam is formed by mixing a polyol composition containing a polyol compound and a foaming agent as essential components and a polyisocyanate component, and foaming and curing. One method for producing rigid polyurethane foam is a spray foaming method. In the spray foaming method, HCFC-141b is used in place of the CFC compound in applications that require high heat insulation (Patent Document 1).

  Although used in Patent Document 1, a spray-foamed rigid polyurethane foam using water as a foaming agent instead of HCFC-141b having an ozone layer depletion coefficient is also known (Patent Document 2).

  The rigid polyurethane foam disclosed in Patent Document 1 uses an aromatic ester polyol and a polyether polyol in combination as a polyol compound.

  In addition, the rigid polyurethane foam disclosed in Patent Document 2 aims to eliminate the skid phenomenon that occurs when the above HCFC-141b is used as a foaming agent. It is used as a component.

JP-A-8-53565 JP-A-10-87774

  However, in the invention disclosed in Patent Document 2, the polyol compound used together with the polyol compound having ethylenediamine as an initiator as the polyol compound is a polyether polyol compound, so that the flame retardancy is not sufficient and is required for a building. It does not clear flame retardant level 3.

  On the other hand, the rigid polyurethane foam disclosed in Patent Document 1 is excellent in flame retardancy because an aromatic ester polyol is used as the main component of the polyol compound. When water is used as a foaming agent in place of HCFC-141b, the viscosity of the polyol composition increases because water does not have the effect of lowering the viscosity as in HCFC-141b. This results in a phenomenon that water and isocyanate are not smoothly reacted. As a result, there is a problem that the flyability of the formed rigid polyurethane foam is reduced, or the foaming stock composition immediately after spray coating causes dripping and the adhesive strength between the construction target substrate and the rigid polyurethane foam is lowered. To do.

  As a technique for solving such a problem, there is a method of using a large amount of a foaming promotion catalyst such as an imidazole compound that accelerates the reaction between water and isocyanate as in Patent Document 2.

  However, a compound having a strong foaming catalytic action such as an imidazole compound has a strong odor and an eye irritation action, which is not preferable in terms of a working environment in spray construction.

  The present invention uses water as a foaming agent, has a small impact on the working environment, has high flame retardancy of the formed rigid polyurethane foam, has good flyability, and has a foaming stock solution composition immediately after spray coating. An object of the present invention is to provide a polyol composition for a rigid polyurethane foam in which the occurrence of dripping is prevented and a method for producing a rigid polyurethane foam using the polyol composition.

The polyol composition of the present invention is a composition containing a polyol compound, water as a foaming agent, a foam stabilizer, a flame retardant and a catalyst, mixed with a polyisocyanate component by a spray device, and reacted to form a rigid polyurethane foam. And
The polyol compound comprises an aromatic ester polyol and a polyether polyol,
It is characterized by containing HFC-134a as an auxiliary foaming agent so as to have a concentration of 0.5 to 5% by weight.

  By using such a polyol composition, water is used as a foaming agent, and it is not necessary to use a large amount of an imidazole catalyst as in Patent Document 2, so that the influence on the working environment is small, flame retardancy is high, and fly A rigid polyurethane foam with good ability can be formed, and the foamed stock solution composition immediately after spray coating can prevent dripping.

  When the concentration of HFC-134a (1,1,1,2-tetrafluoroethane) is less than 0.5% by weight, the dripping prevention effect of the foamed stock composition immediately after spray coating is insufficient, and 5% by weight On the other hand, if it exceeds 50%, the adhesion between the construction target base material and the rigid polyurethane foam is lowered. The concentration of HFC-134a is more preferably 0.5 to 2.0% by weight.

Another invention is a rigid polyurethane foam in which a polyol composition containing a polyol compound, water as a foaming agent, a foam stabilizer, a flame retardant, and a catalyst is mixed with a polyisocyanate component and reacted to form a rigid polyurethane foam. A manufacturing method of
The polyol compound comprises an aromatic ester polyol and a polyether polyol,
The polyol composition is characterized in that it contains HFC134a as an auxiliary blowing agent in a concentration of 0.5 to 5% by weight.

  According to the production method having such a configuration, water is used as a foaming agent constituting the polyol composition, and it is not necessary to use a large amount of an imidazole catalyst as in Patent Document 2, so that the influence on the working environment is small and flame retardant. And a rigid polyurethane foam having high flyability can be formed, and the foamed stock solution composition immediately after spray coating can prevent dripping.

  In the polyol composition for rigid polyurethane foam and the method for producing the rigid polyurethane foam of the present invention, it is preferable to use an aromatic ester polyol and a polyether polyol as the polyol compound constituting the polyol composition. The ratio of aromatic ester polyol / polyether polyol is preferably 40/60 to 90/10 (weight ratio), more preferably 45/55 to 85/15, and 55/45 to 85/15. More preferably.

  When the blending ratio of the aromatic ester polyol is small, the flame retardancy of the formed foam decreases, and when it is too large, dripping of the foamed stock composition immediately after spray coating occurs, and the foam flyability decreases. Problems occur.

  The aromatic ester polyol is an aromatic dicarboxylic acid glycol ester, and at least one selected from terephthalic acid, phthalic acid, and isophthalic acid, and ethylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, Examples include ester polyols having a hydroxyl group terminal based on glycol with glycol such as polyoxyethylene glycol having an average molecular weight of 150 to 500. The aromatic ester polyol preferably has a functional group number of 2 to 2.5 and a hydroxyl value of 100 to 600 mgKOH / g.

  As the polyether polyol, it is preferable to use a polyether polyol containing an aliphatic amine polyol.

  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. 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. Among these, use of a polyether polyol having ethylenediamine as an initiator is particularly preferable.

  As the polyether polyol used together with the aliphatic amine polyol, an aromatic polyether polyol such as glycerol, pentaerythritol, sorbitol, sucrose or the like, an aliphatic polyether polyol or toluene diamine as an initiator. Examples thereof include aromatic amine polyols and Mannich polyols that use amine as an initiator. Among these, the use of Mannich polyol is preferable because the strength and flame retardancy of the resulting rigid polyurethane foam are excellent.

  Mannich polyol is obtained by ring-opening addition polymerization of at least one of ethylene oxide and propylene oxide to an active hydrogen compound obtained by the Mannich reaction of phenol and / or its alkyl-substituted derivative, formaldehyde and alkanolamine, or this compound. It is a polyol compound having a hydroxyl value of 250 to 550 mgKOH / g and having 2 to 4 functional groups. As a commercial item of such a polyol compound, for example, there is DK-3810 (Daiichi Kogyo Seiyaku) and 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. Specific examples include trimethylolpropane, glycerin, pentaerythritol, triethanolamine, methyldiethanolamine and the like.

The density of the rigid polyurethane foam of the present invention is preferably 15 to 45 kg / m ³ .

  Water is used as the blowing agent. The addition amount of water is appropriately set according to the density of the foam to be formed, but the addition amount with respect to 100 parts by weight of the polyol compound is preferably 2 to 10 parts by weight, and more preferably 2 to 7 parts by weight. .

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

  Examples of the catalyst include 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), N, N-dimethylcyclohexylamine (Polycat-8), triethylenediamine, N— It is preferable to use tertiary amines such as methylmorpholine.

  It is also preferable to use a catalyst that forms an isocyanurate bond that contributes to an improvement in flame retardancy in the structure of the polyurethane molecule. For example, potassium acetate, potassium octylate, a quaternary ammonium salt catalyst (disclosed in JP-A-9-104734) is used. It can be illustrated. Some of the above-mentioned tertiary amine catalysts also promote the isocyanurate ring formation reaction. A catalyst that promotes the formation of isocyanurate bonds and a catalyst that promotes the formation of urethane bonds may be used in combination.

  As the foam stabilizer, known foam stabilizers used in the technical field of rigid polyurethane foam can be used without limitation. Specifically, foam stabilizers such as B-8465 (Gold Schmidt), SH-193, S-824-02, SZ-1704 (Toray Dow Corning Silicon) can be used. Two or more foam stabilizers may be used.

  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 40 parts by weight or less, preferably 5 to 40 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.

  The viscosity of the polyol composition of the present invention is preferably 1000 mPa · s (20 ° C.) or less, and preferably 800 mPa · s (20 ° C.) or less, from the viewpoint of easily producing a rigid polyurethane foam by a spray method. More preferred.

  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 method for producing the 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 1.0 to 4.0, more preferably 1.0. It is -3.0, More preferably, it is 1.0-2.0.

(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 A
Ester polyol (Toho Rika) produced by a known method using terephthalic acid and 5% by weight of ricinoleic acid based on terephthalic acid and diethylene glycol as a glycol component;
Hydroxyl value = 250 mgKOH / g, Viscosity = 3000 mPa · sec (25 ° C.)
b) Polyol B
Polyether polyol compound (made by Asahi Glass Urethane) using ethylenediamine as an initiator;
Hydroxyl value = 500 mgKOH / g, Viscosity = 6000 mPa · sec (25 ° C.)
c) Polyol C
DK-3810 (Daiichi Kogyo Seiyaku);
Hydroxyl value = 315 mgKOH / g, viscosity = 1300 mPa · sec (25 ° C.)
d) TMCPP: Phosphorus flame retardant (plasticizer) (Daihachi Chemical Industry)
e) Catalyst A: Kaolinizer No. 1 (Kao-No.1) (Kao)
B: Imidazole catalyst f) Foam stabilizer SZ-1704 (Toray Dow Corning Silicon)
g) Polyisocyanate component: Sumidur 44V-20 (Sumika Bayer Urethane).

(Examples and comparative examples)
In Examples and Comparative Examples, the polyol compound A is 70 parts by weight, the polyol compound B is 20 parts by weight, and the polyol compound C is 10 parts by weight ((polyol compound A) / (polyol compound B + polyol compound C) = 70/30). , 40 parts by weight of flame retardant TMCPP (Daihachi Chemical Industry), 4.0 parts by weight of water as a foaming agent, Kaolinizer No. 1 was 5.0 parts by weight and the foam stabilizer was 1.5 parts by weight. The polyol composition was prepared by changing the amount of auxiliary foaming agent HFC-134a as shown in Table 1. . In Comparative Example 2, 4.0 parts by weight of an imidazole catalyst was added as a foaming catalyst without adding HFC-134a. The obtained polyol composition and the polyisocyanate component were used at a volume ratio of 1: 1 (NCO / OH equivalent ratio of 1.0 (calculated excluding 2 equivalent of NCO groups consumed per 1 mol of water)). Spray foaming was applied to make a rigid polyurethane foam with spray foaming, and the spray foaming test was performed on a plywood sheet placed almost vertically and placed on it.

(Evaluation)
1) Spray evaluation While performing the above-mentioned spray foaming construction test, odor and dripping were observed.

2) Flammability (flame retardant evaluation)
A predetermined sample was cut out from the formed rigid polyurethane foam, and flame retardancy was evaluated in accordance with JIS A 1321. The evaluation results are indicated as good if the classification is flame retardant class 3 and suitable for the surface test, and non-conforming as defective.

3) Adhesiveness to the face material The face material is peeled by hand from the hard polyurethane foam to which the face material is adhered, and the face material is adhered to such an extent that the material breaks down. If it can be easily peeled off, it was regarded as defective.

  From the results shown in Table 1, the spray foamed rigid polyurethane foam using the polyol composition of the present invention has little odor generation and no dripping at the time of construction, and the formed rigid polyurethane foam is evaluated according to JIS A 1321 regulations. It was excellent in flame retardancy and had good adhesion to the substrate. On the other hand, in Comparative Example 1 in which HFC-134a was not added, dripping occurred and the adhesion to the substrate was poor. In Comparative Example 3 in which the amount of HFC-134a added exceeds 5% by weight, the adhesion to the base material was lowered, and in Comparative Example 2, no dripping occurred even without adding HFC-134a. The odor during construction was strong and not satisfactory.

Claims (2)

A polyol composition comprising water, a foam stabilizer, a flame retardant and a catalyst as a foaming agent, mixed with a polyisocyanate component by a spray device, and reacted to form a rigid polyurethane foam,
The polyol compound comprises an aromatic ester polyol and a polyether polyol,
A polyol composition for spray-foamed rigid polyurethane foam, comprising HFC134a as an auxiliary foaming agent in a concentration of 0.5 to 5% by weight. A method for producing a rigid polyurethane foam comprising mixing a polyol composition containing a polyol compound, water as a foaming agent, a flame retardant, a flame retardant and a catalyst with a polyisocyanate component and reacting them to form a rigid polyurethane foam. ,
The polyol compound comprises an aromatic ester polyol and a polyether polyol,
The said polyol composition contains HFC134a as an auxiliary | assistant foaming agent so that it may become a density | concentration of 0.5-5 weight%, The manufacturing method of the spray foaming rigid polyurethane foam characterized by the above-mentioned.