JP2006335810A - 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 excellent flame retardancy and excellent adhesion to a face material using an HFC compound as a foaming agent, and a method for producing a rigid polyurethane foam using the polyol composition I will provide a.
A polyol compound, 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. The polyol compound contains an ester polyol. The foaming agent contains 1,1,1,3,3-pentafluoropropane (HFC-245fa) and 1,1,1,3,3-pentafluorobutane (HFC365mfc), and the catalyst is 1 , 8-diazabicyclo [5,4,0] undecene (DBU) polyol composition for spray foamed rigid polyurethane foam containing a phenol compound salt.
[Selection figure] None

Description

  The present invention relates to a spray-foamed polyol composition for rigid polyurethane foam that forms a highly heat-insulating rigid polyurethane foam, and a method for producing a rigid polyurethane foam using the polyol composition.

  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. In the past, fluorocarbon compounds such as CFC-11 have been used as foaming agents, but CFC compounds are prohibited because they cause the destruction of the ozone layer. At present, rigid polyurethane foams are roughly divided into three types of foaming agents. Is manufactured and used.

  The first blowing agent is water, and a foam is formed by carbon dioxide gas generated by the reaction between water and an isocyanate group. The rigid polyurethane foam obtained by water foaming contains carbon dioxide in the bubbles immediately after production, but the carbon dioxide diffuses into the atmosphere over time, and nitrogen and the like are present in the bubbles. It becomes like this. As a result, it is difficult to lower the thermal conductivity of water-foamed rigid polyurethane foam as much as other foaming agents, and it cannot be used for applications requiring high heat insulation.

  The second blowing agent is pentanes such as cyclopentane and iso-pentane, and foams using such pentanes are excellent in heat insulating properties, but the pentane is highly flammable. Has a problem that a facility for preventing fire is necessary, and a conventional apparatus for producing rigid polyurethane foam cannot be used as it is, and remodeling or new installation is very expensive. In particular, in the case of spray foaming, if pentane is used as a foaming agent, it is volatilized during the spraying operation, so that it is substantially impossible to use.

  As the third blowing agent, an HFC compound having an ozone layer depletion coefficient of zero is known, and volatilization of the blowing agent in the polyol composition when using HFC-245fa having a boiling point of 15 ° C. is prevented. A technique for adding a compatibilizing agent such as ε-caprolactone to prevent swelling of a container such as a drum can or a petroleum can containing a polyol composition is known (for example, Patent Document 1).

JP 2004-107439 A

  However, since HFC compounds such as HFC-245fa and HFC-365mfa do not contain chlorine or bromine, they do not have the effect of improving the flame retardancy of the foam. This improves the compatibility of the foaming agent in the polyol composition contained as the agent with the polyol compound and lowers the vapor pressure, and does not give consideration to flame retardancy. For this reason, improvement in the flame retardance of the rigid polyurethane foam obtained with the polyol composition is demanded particularly for architectural use.

  As a means for enhancing the flame retardancy of a rigid polyurethane foam using an HFC compound as a foaming agent, an aromatic ester polyol is used as a polyol compound constituting the raw material polyol composition, and at the same time, the amount of the isocyanate component is increased. It is conceivable to increase the NCO / OH reaction ratio (NCO index) by increasing the blending amount of the isocyanurate ring concentration in the foam-constituting resin.

  However, it has been found that when the amount of the aromatic ester polyol is increased as described above and the NCO index is increased and the rigid polyurethane foam is produced by the spray foaming method, the adhesiveness to the face material and the substrate is lowered.

  The present invention relates to a polyol composition for rigid polyurethane foam having excellent flame retardancy and excellent adhesion to a face material while using an HFC compound such as HFC-245fa and HFC-365mfa as a foaming agent, and the polyol composition An object of the present invention is to provide a method for producing a rigid polyurethane foam using a product.

The polyol composition for spray foamed rigid polyurethane foam of the present invention comprises a polyol compound, 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. And
The polyol compound contains an ester polyol,
The foaming agent contains 1,1,1,3,3-pentafluoropropane (HFC-245fa) and 1,1,1,3,3-pentafluorobutane (HFC365mfc),
The catalyst includes a phenol compound salt of 1,8-diazabicyclo [5,4,0] undecene (DBU).

  Rigid polyurethane foam formed using a polyol composition with such a structure has high heat insulating properties due to the use of an HFC compound, and also has excellent flame retardancy and excellent adhesion to a face material. It is.

Another aspect of the present invention is a method for producing a spray foamed rigid polyurethane foam in which a polyol composition containing a polyol compound, a foaming agent, a foam stabilizer and a catalyst is mixed with a polyisocyanate component and reacted to form a rigid polyurethane foam. There,
The polyol compound contains an ester polyol,
The blowing agent comprises HFC-245fa and HFC365mfc;
The catalyst includes a phenol compound salt of 1,8-diazabicyclo [5,4,0] undecene (DBU).

  Due to the manufacturing method having such a configuration, since the HFC compound is used, it is possible to manufacture a rigid polyurethane foam having high heat insulation, excellent flame retardancy, and excellent adhesion to the face material by the spray method. .

  In the method for producing a polyol composition and a rigid polyurethane foam of the present invention, an ester polyol having a functional group number of 1.8 to 2.5 and a hydroxyl value of 200 to 600 mgKOH / g is used as the polyol compound.

  In the polyol composition for spray-foamed rigid polyurethane foam of the present invention, the Mannich polyol having a hydroxyl value of 250 to 550 mgKOH / g and a functional group number of 2 to 4 is more than ester polyol / Mannich polyol = 40/60 (weight ratio). It is more preferable to contain it.

  With such a configuration, it is possible to produce a rigid polyurethane foam having more excellent flame retardancy. The ester polyol may be 100. The weight ratio of ester polyol / Mannich polyol is more preferably 80/20 to 50/50. If the ratio of Mannich polyol is too large, the flame retardancy is lowered.

  The ester polyol preferably contains an aromatic dicarboxylic acid glycol ester and a fatty acid compound having 8 to 22 carbon atoms.

  By using a fatty acid compound having 8 to 22 carbon atoms as the polyol compound, the compatibility of the HFC compound as a foaming agent as the polyol composition is improved.

  Examples of the aromatic dicarboxylic acid glycol ester include terephthalic acid, phthalic acid, isophthalic acid and the like, ethylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, polyoxyethylene glycol having an average molecular weight of 300 to 500, and the like. Examples thereof include ester polyols having a hydroxyl group terminal based on glycol. Among these, use of an ester polyol of terephthalic acid is preferable because a rigid polyurethane foam excellent in flame retardancy can be formed.

  As the fatty acid compound having 8 to 22 carbon atoms, a fatty acid compound having 8 to 22 carbon atoms or a reaction product of oil and fat containing the fatty acid and glycol can be used. As fatty acids having 8 to 22 carbon atoms, as fatty acids obtained from nature, caprylic acid, capric acid, linoleic acid, linolenic acid, oleic acid, stearic acid, palmitic acid, lauric acid, myristic acid, ricinoleic acid, tall oil fatty acid Etc. are exemplified.

  Examples of the synthetic fatty acid having 8 to 22 carbon atoms include isocaprilic acid, 2-ethylhexanoic acid, isononanoic acid, isocapriic acid, isolauric acid, isopalmitic acid, and isostearic acid.

  Fats and oils containing the above fatty acids include corn oil, cottonseed oil, olive oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, coconut oil, palm oil, linseed oil, tall oil, and other vegetable oils, beef fat, pork Animal fats and oils such as fat and whale oil are exemplified.

  The ester polyol of the present invention may be an alkyl ester such as the above fatty acid or its methyl ester, and an oil or fat mainly composed of the above fatty acid may be allowed to react with a glycol in the presence of the ester polyol in the presence of an aromatic dicarboxylic acid. The fatty acid compound obtained by reacting glycol in advance may be added to an aromatic ester polyol composed of an aromatic dicarboxylic acid and glycol. The above naturally-derived fatty acids and synthetic fatty acids may be used alone or in combination of two or more.

  The ester polyol containing a fatty acid compound can be produced by a known method. Presence of a known esterification reaction catalyst such as a titanium compound obtained by mixing an aromatic dicarboxylic acid such as terephthalic acid and a fatty acid having 8 to 22 carbon atoms or a fat or oil of the fatty acid in a predetermined amount and adding glycol. It can manufacture by heating to 200 to 230 degreeC under nitrogen stream below.

  The content of the fatty acid compound in the ester polyol is preferably 1 to 20% by weight, and more preferably 1 to 10% by weight. If the amount is less than 1% by weight, the effect of improving the compatibility of the HFC compound is small, and if it is too much, the flame retardancy of the resulting foam is lowered.

  Mannich polyol is obtained by ring-opening addition polymerization of at least one of ethylene oxide and propylene oxide on an active hydrogen compound obtained by the Mannich reaction of phenol and / or its alkyl-substituted derivative, formaldehyde and alkanolamine. 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, DK-3810, 3773 (Daiichi Kogyo Seiyaku) and the like can be used.

  The polyol composition of the present invention may further contain at least one polyol compound (amine polyol) having a hydroxyl value of 200 to 500 mgKOH / g selected from aliphatic amine polyols and aromatic amine polyols. 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.

  When the amine polyol is used in combination, the weight ratio of (ester polyol + Mannich polyol) / amine polyol is preferably 40/60 or more, and more preferably 90/10 to 60/40. If the amount of amine polyol used is too large, the flame retardancy of the resulting foam will be reduced.

  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 blowing agent used in the method for producing the polyol composition and the rigid polyurethane foam of the present invention contains HFC-245fa and HFC-365mfc. By using such a foaming agent, a rigid polyurethane foam having excellent heat insulation can be obtained. The ratio of HFC-245fa / HFC-365mfc is preferably 95/5 to 60/40. The addition amount of the HFC compound is preferably 20 to 50 parts by weight with respect to 100 parts by weight of the total polyol compounds.

  Further, it is preferable to add water as a foaming agent. By adding water, the vapor pressure of the blowing agent of the polyol composition can be reduced. The amount of water added is preferably 0.5 to 5 parts by weight relative to 100 parts by weight of the total polyol compound.

  As the phenol compound constituting the phenol compound salt of 1,8-diazabicyclo [5,4,0] undecene (DBU) which is a catalyst component, a highly volatile compound having a phenol group can be used without limitation. Specifically, phenol, cresol, an alkyl group-substituted phenol such as an ethyl group, and the like are exemplified.

  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 foam stabilizer, a known foam stabilizer 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.

  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), tertiary amines such as N, N-dimethylcyclohexylamine (polycat-8), triethylenediamine, N-methylmorpholine Is preferably used.

  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.

  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 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, etc. (manufactured by Sumika Bayer Urethane Co., Ltd.), Millionate MR-200 (Nippon Polyurethane Industry)), uretonimine-containing MDI (Millionate) MTL (manufactured by Nippon Polyurethane Industry) or the like is 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 1.5. It is -3.5, More preferably, it is 1.5-2.0. More preferably, the NCO index is 1.5 or more, and the catalyst contains a trimerization catalyst.

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. The density of the rigid polyurethane foam produced according to the present invention is preferably 25 kg / m ^{3 to} 50 kg / m ³ .

(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
DK-3810 (Daiichi Kogyo Seiyaku);
Hydroxyl value = 315 mgKOH / g, viscosity = 1300 mPa · sec (25 ° C.)
c) Polyol C
Polyether polyol compound (made by Asahi Glass Urethane) using ethylenediamine as an initiator;
Hydroxyl value = 500 mgKOH / g, Viscosity = 6000 mPa · sec (25 ° C.)
d) TMCPP: Phosphorus flame retardant (plasticizer) (Daihachi Chemical Industry)
e) Catalyst kaolinizer No. 1 (Kao-No.1) (Kao)
(The amount added is expressed in parts by weight relative to 100 parts by weight of the total amount of polyol compound)
DBU phenol salt (SA No.1: San Apro)
(The amount added is expressed as a percentage by weight with respect to the total amount of polyol compound)
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, a polyol composition was prepared by blending a polyol compound described in the upper part of Table 1. The compound other than the polyol compound and the catalyst is 100 parts by weight of the total amount of the polyol compound, 20 parts by weight of the flame retardant TMCPP (Daihachi Chemical Industry), and the blowing agent is HFC-245fa / HFC-365mfc = 80/20 (weight ratio) 37.5 parts by weight and 1.0 part by weight of water. In the production of rigid polyurethane foam, a polyol composition and a polyisocyanate component are mixed with a laboratory stirrer so that the isocyanate index (NCO / OH equivalent ratio) is a ratio described in Table 1, and is a face material. A foam was manufactured by casting into a 200 mm × 200 mm × 200 mm mold laid with kraft paper. The evaluation described below was performed, and the results are shown in the lower part of Table 1.

(Evaluation)
1) Residual NCO group Using an IR spectrum measurement apparatus 1600FT-IR (Perkin Elmer), the residual NCO group concentration was determined from the intensity of the peak based on the NCO group of 2250 cm -1 for the rigid polyurethane foam 24 hours after the production. (Please also disclose the calculation method.)

2) 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.

3) Flammability (flame retardant evaluation)
Flame retardant evaluation was performed in accordance with JIS A 1321. The evaluation results are indicated as “◯” when the classification is flame retardant level 2 and conforming to the determination of the surface test, and “X” when not conforming.

4) Adhesiveness to the face material As shown in FIG. 1, a notch with a width of 5 cm is formed in the face material, and the face material from which the end has been peeled is pulled in the arrow (W) direction with a spring balance to increase the peel strength. It was measured.

5) Thermal conductivity A thermal conductivity measuring device AUTO-Λ HC-074 (manufactured by Eihiro Seiki Co., Ltd.) was used, and the measurement conditions were measured according to JIS A 9511.

  From the results in Table 1, the spray foamed rigid polyurethane foam using the polyol composition of the present invention was excellent in flame retardancy according to the evaluation of JIS A 1321 regulations. On the other hand, the foam of Comparative Example 1 in which no ester polyol was used was insufficient in flame retardancy, and the foam of Comparative Example 2 in which the ratio of the ester polyol was 35 parts by weight in the total amount of the polyol compound and no DBU phenol salt was used. The residual NCO group concentration was high, and the flame retardancy, adhesion to the substrate and heat insulation were also insufficient. Further, the foam of Comparative Example 3 which uses the same polyol composition as in Example 2 and does not use the DBU phenol salt has a high foam hardness but a high residual NCO group concentration, and adhesion to a flame retardant substrate. It was not satisfactory in heat insulation.

The figure which showed the measuring method of the adhesive strength of the face material and foam of rigid polyurethane spray foam

Claims (6)

A polyol composition comprising a polyol compound, a foaming 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 compound contains an ester polyol,
The foaming agent contains 1,1,1,3,3-pentafluoropropane (HFC-245fa) and 1,1,1,3,3-pentafluorobutane (HFC365mfc),
A polyol composition for spray foamed rigid polyurethane foam, wherein the catalyst contains a phenol compound salt of 1,8-diazabicyclo [5,4,0] undecene (DBU).   2. The spray foamed rigid polyurethane according to claim 1, further comprising Mannich polyol having a hydroxyl value of 250 to 550 mgKOH / g and a functional group number of 2 to 4 so that the ester polyol / Mannich polyol is 40/60 or more. Polyol composition for foam.   The polyol composition for spray foamed rigid polyurethane foam according to claim 1 or 2, wherein the ester polyol contains an aromatic dicarboxylic acid glycol ester and a fatty acid compound having 8 to 22 carbon atoms. A method for producing a rigid polyurethane foam comprising mixing a polyol composition containing a polyol compound, a foaming agent, a foam stabilizer and a catalyst with a polyisocyanate component, and reacting the mixture to react to form a rigid polyurethane foam,
The polyol compound contains an ester polyol,
The blowing agent comprises HFC-245fa and HFC365mfc;
A process for producing a spray foamed rigid polyurethane foam, wherein the catalyst contains a phenol compound salt of 1,8-diazabicyclo [5,4,0] undecene (DBU).   5. The polyol composition further comprises Mannich polyol having a hydroxyl value of 250 to 550 mg KOH / g and a functional group number of 2 to 4 so that ester polyol / Mannich polyol = 40/60 or more. A method for producing the spray foamed rigid polyurethane foam described.   The method for producing a spray foamed rigid polyurethane foam according to claim 4 or 5, wherein the ester polyol contains an aromatic dicarboxylic acid glycol ester and a fatty acid compound having 8 to 22 carbon atoms.

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