JP2008189882A - Polyol composition for spray-foamed rigid polyurethane foam and manufacturing process for spray-foamed rigid polyurethane foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyol composition for spray-foamed rigid polyurethane foams which uses an HFC compound such as HFC-245fa and HFC-365mfa as a foaming agent, has an excellent heat insulation, meets the grade 3 flame retardancy and has restricted lateral expansion, and a manufacturing process for the rigid polyurethane foam using the polyol composition. <P>SOLUTION: The polyol composition contains a polyol compound, a foaming agent composed of an HFC compound, a foam stabilizer and a catalyst. forms a rigid polyurethane foam by being mixed and reacted with a polyisocyanate component using a spray apparatus. The catalyst comprises a catalyst for forming an isocyanurate group. The polyol compound of 100 pts.wt. contains 40-80 pts.wt. of an aromatic ester polyol with a hydroxyl value of 150-450 mgKOH/g and 10-40 pts.wt. of an aliphatic amine polyol with a hydroxyl value of 350-800 mgKOH/g. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spray-foamed polyol composition for rigid polyurethane foam that forms a highly heat-insulating and flame-retardant 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. 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.

  The rigid polyurethane foam disclosed in Patent Document 2 aims to eliminate the side slip phenomenon that occurs when the above HCFC-141b is used as a foaming agent, and a polyol compound using ethylenediamine as an initiator is one of the polyol compounds. It is used as a component.

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

  However, the rigid polyurethane foam disclosed in Patent Document 2 uses water as a foaming agent, and 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. It does not clear the flame retardant level 3 required for buildings. In addition, since water is used as a foaming agent, there is a problem that the foam shrinks due to a change with time and a heat insulation performance is not sufficient.

  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. If an HFC compound having a small ozone layer depletion coefficient is used in place of HCFC-141b, a phenomenon called side slip (also referred to as lateral elongation) described in Patent Document 2 occurs.

  The present invention uses a polyol for rigid polyurethane foam that uses an HFC compound such as HFC-245fa and HFC-365mfa as a foaming agent, has excellent heat insulation properties, is compatible with flame retardant grade 3 and prevents the occurrence of lateral elongation. An object of the present invention is to provide a composition and a method for producing a rigid polyurethane foam using the polyol composition.

The polyol composition of the present invention comprises a polyol compound, a foaming agent comprising an HFC compound, a foam stabilizer and a catalyst, mixed with a polyisocyanate component by a spray device, and reacted to form a rigid polyurethane foam,
The catalyst contains an isocyanurate group-forming catalyst,
100 parts by weight of the polyol compound includes 40 to 80 parts by weight of an aromatic ester polyol having a hydroxyl value of 150 to 450 mgKOH / g and 10 to 40 parts by weight of an aliphatic amine polyol having a hydroxyl value of 350 to 800 mgKOH / g. It is characterized by.

  Rigid polyurethane foam formed by spray foaming using a polyol composition with such a structure uses an HFC compound as a foaming agent, has excellent heat insulation properties, conforms to flame retardant grade 3, and prevents the occurrence of lateral elongation phenomenon It has been done.

  When the blending ratio of the aromatic ester polyol is too large, the lateral stretchability is lowered and the strength of the foam is lowered, and when it is too little, the flame retardancy is lowered and the flame retardancy is not suitable. The aromatic ester polyol is more preferably 40 to 65 parts by weight. The hydroxyl value of the aromatic ester polyol is more preferably 400 or less. Moreover, when there are too many aliphatic amine polyols, a flame retardance will fall, and when too few, the reactivity with a polyisocyanate component will fall. The aliphatic amine polyol is more preferably 15 to 30 parts by weight.

  In the polyol composition for spray-foamed rigid polyurethane foam, a Mannich polyol having a hydroxyl value of 250 to 550 mgKOH / g and a functional group number of 2 to 4 may further contain 10 to 40 parts by weight in 100 parts by weight of the polyol compound. preferable.

  The rigid polyurethane foam formed by spray foaming using the polyol composition having such a configuration has good adhesion to the face material and the base material to be sprayed, and has excellent strength.

Another aspect of the present invention is the production of a rigid polyurethane foam in which a polyol composition comprising a polyol compound, an HFC compound, a foam stabilizer, a foam stabilizer and a catalyst is mixed with a polyisocyanate component and reacted to form a rigid polyurethane foam. A method,
The catalyst contains an isocyanurate group-forming catalyst,
100 parts by weight of the polyol compound includes 40 to 80 parts by weight of an aromatic ester polyol having a hydroxyl value of 150 to 450 mgKOH / g and 10 to 40 parts by weight of an aliphatic amine polyol having a hydroxyl value of 350 to 800 mgKOH / g. It is characterized by.

  According to the manufacturing method having such a configuration, it is possible to form a rigid polyurethane foam that uses an HFC compound as a foaming agent and has excellent heat insulation properties and does not cause a lateral elongation phenomenon and is suitable for flame retardant grade 3.

  In the method for producing the spray foamed rigid polyurethane foam, the polyol composition further comprises 10 to 40 parts by weight of Mannich polyol having a hydroxyl value of 250 to 550 mgKOH / g and a functional group number of 2 to 4 in 100 parts by weight of the polyol compound. It is preferable to contain.

  According to the method for producing a rigid polyurethane foam having such a configuration, it is possible to produce a rigid polyurethane foam having excellent adhesion with a face material or a base material to be sprayed and having excellent strength.

  In the above-mentioned method for producing a spray foamed rigid polyurethane foam, the equivalent ratio of NCO groups / OH groups in the mixing of the polyol composition and the polyisocyanate component is preferably 1.0 to 3.5, 1.2 More preferably, it is -2.5.

  According to the manufacturing method having such a configuration, an isocyanurate bond is formed in the molecule of the hard polyurethane to be formed, and the flame retardancy of the foam is improved.

  In the polyol composition for rigid polyurethane foam and the method for producing the rigid polyurethane foam of the present invention, an aromatic ester polyol and an aliphatic amine polyol are used as the polyol compound constituting the polyol composition, preferably Mannich polyol is further used. .

  The aromatic ester polyol having a hydroxyl value of 100 to 600 mgKOH / g is an aromatic dicarboxylic acid glycol ester, ethylene glycol, diethylene glycol, 1,4-butane and at least one selected from terephthalic acid, phthalic acid, and isophthalic acid. Examples include ester polyols having a hydroxyl end based on glycols such as diol, 1,6-hexanediol, and glycols such as polyoxyethylene glycol having an average molecular weight of 150 to 500.

  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.

  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-3776 (Daiichi Kogyo Seiyaku), which can be used. The hydroxyl value of Mannich polyol is more preferably 250 to 450 mgKOH / g.

  In the present invention, it is a preferred embodiment that a part of the Mannich polyol is replaced with a polyol containing resin fine particles. According to such a configuration, the mechanical strength of the rigid polyurethane foam to be formed becomes more excellent. The compounding amount of the resin fine particle-containing polyol is 20 parts by weight or less, and more preferably 15 parts by weight or less.

  The polyol compound containing the resin fine particles can be produced by a known method, but the method of polymerizing in the polyol compound to form the resin fine particles is a stable polyol composition in which the particles hardly settle even if left for a long time. Since a thing is obtained, it is the most preferable. It is also preferable to use a commercially available product as the polyol compound in which the resin fine particles of the monomer are dispersed. Specifically, XRAG-7102 produced by a polymerization method of a monomer containing acrylonitrile in the above-described polyol compound, WB-918 (Asahi Glass) is available.

  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 is an HFC compound. As the HFC compound, at least one of HFC-245fa and HFC-365mfc can be used. By using such a foaming agent, a rigid polyurethane foam having excellent heat insulation can be obtained. It is also preferable to use HFC-245fa and HFC-365mfc in combination. In the case of using HFC-245fa and HFC-365mfc together, 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 catalyst, at least an isocyanurate group forming catalyst is used. Examples of the isocyanurate group-forming catalyst (trimerization catalyst) include alkali metal salts of organic carboxylic acids having 1 to 20 carbon atoms such as potassium acetate, potassium propionate, potassium 2-ethylhexanoate (potassium octylate), and N- (2-Hydroxypropyl) -N- (2-hydroxyethyl) -N, N-dimethylammonium octylate, N-hydroxyalkyl-N, N, N-trialkylammonium salt, etc. JP-A-9-104734 At least one compound selected from quaternary ammonium salt catalysts such as the compounds disclosed in the publication is used.

  In the polyol composition for rigid polyurethane foam and the method for producing the rigid polyurethane foam of the present invention, a tertiary amine catalyst is used in addition to the isocyanurate bond-forming catalyst. The tertiary amine catalyst is a urethane bond forming catalyst or a foaming catalyst. Specifically, N, N, N ′, N′-tetramethylethylenediamine or N, N, N ′, N′-tetramethylhexamethylene is used. N-alkyl polyalkylene polyamines such as diamine (kaolyzer No. 1), N, N, N ′, N ′, N ″ -pentamethyldiethylenetriamine (kaolyzer No. 3), diazabicycloundecene (DBU), N , N-dimethylcyclohexylamine (Polycat-8), triethylenediamine, N-methylmorpholine, and the like can be used.

  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.

  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.

  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 above-mentioned 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 1.0 to 4.0, more preferably 1.2. It is -3.5, More preferably, it is 1.5-2.5. More preferably, the NCO index is 1.2 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.
<Polyol compound>
Polyol A
Aromatic ester polyol composed of benzenedicarboxylic acid and diethylene glycol (Hitachi Chemical);
Hydroxyl value = 260 mgKOH / g, viscosity = 2500 mPa · sec (25 ° C.)
Polyol B
Polyether polyol compound (made by Asahi Glass Urethane) using ethylenediamine as an initiator;
Hydroxyl value = 760 mgKOH / g, Viscosity = 45000 mPa · sec (25 ° C.)
Polyol C
Polyether polyol compound (made by Asahi Glass Urethane) using ethylenediamine as an initiator;
Hydroxyl value = 600 mgKOH / g, viscosity = 8000 mPa · sec (25 ° C.)
Polyol D
Polyether polyol compound (made by Asahi Glass Urethane) using ethylenediamine as an initiator;
Hydroxyl value = 450 mgKOH / g, Viscosity = 6000 mPa · sec (25 ° C.)
Polyol E
Mannich polyol (Daiichi Kogyo Seiyaku);
Hydroxyl value = 350 mgKOH / g, Viscosity = 2600 mPa · sec (25 ° C.)
Polyol F
A resin fine particle-containing polyol obtained by polymerizing a monomer containing acrylonitrile in a Mannich polyol;
Hydroxyl value = 320 mgKOH / g, Viscosity = 1500 mPa · sec (25 ° C.)
<Crosslinking agent>
A mixture of glycol and ethylenediamine obtained by adding 2.5 mol of propylene oxide to bisphenol A: hydroxyl value = 800 mgKOH / g
<Flame Retardant>
TMCPP (Daihachi Chemical Industry)
<Catalyst>
Kaulizer No. 1 (Kao-No.1) (Kao)
Potassium octylate lead octenoate
<Foam stabilizer>
SZ-1704 (Toray Dow Corning Silicon)
<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 (including this when a crosslinking agent is used), 20 parts by weight of the flame retardant TMCPP (Daihachi Chemical Industry), and the blowing agent is HFC. A mixture of −245fa / HFC-365mfc = 80/20 (weight ratio) and water were used. In the production of rigid polyurethane foam, the polyol composition and the polyisocyanate component are mixed so that the isocyanate index (NCO / OH equivalent ratio) is the ratio described in Table 1 to obtain a foamed stock solution composition, which is foam-cured. To produce a rigid polyurethane foam. The evaluation described below was performed, and the results are shown in the lower part of Table 1. The isocyanate index is calculated for other OH groups, with 2 equivalents of NCO groups consumed by 1 mol of water.

(Evaluation)
1) Foam density (kg / m ³ )
A foaming stock solution composition is prepared by stirring with a mixer, freely foamed using a mold of 200 mm × 200 mm, depth of 200 mm, and 100 mm × 100 mm in thickness from the core layer obtained by removing the skin layer from the obtained rigid polyurethane foam. A 100 mm foam sample was cut out and weighed to calculate the density (kg / m ³ ).

2) Reactivity The polyol composition and the polyisocyanate component are sprayed and foamed and cured at room temperature on a kraft paper face material which is attached to a plywood installed vertically using a commercially available spray foaming device, and the thickness is 20 A rigid polyurethane foam of ˜25 mm was formed. The occurrence of dripping at the time of spray foaming was visually observed to evaluate the reactivity. The results are shown as “Good” for those with no dripping, “Δ” for those with little reactivity, “B” for those with little occurrence, and “x” for those with large dripping and low reactivity, which are impractical.

3) Flammability (flame retardant evaluation)
A sample was cut out from the rigid polyurethane foam formed by spray foaming in the above 2) and evaluated for flame retardancy in accordance with JIS A 1321. The evaluation results are indicated as “◯” when the classification is flame retardant class 3 and conforming to the determination of the surface test, and “X” is not conforming.

4) Lateral stretchability The rigid polyurethane foam formed by spray foaming of 2) above is cut in the horizontal direction after completion of foam curing and foamed in the lateral direction from the coating position of the foamed stock solution composition. The distance was measured. The measurement was performed at 10 locations, and the average value was obtained.

5) Adhesiveness to the face material As shown in FIG. 1, the foam produced in the evaluation of the lateral stretchability was formed by forming a notch having a width of 5 cm on the face material and peeling off the end portion from the spring. The peel strength was measured by pulling in the arrow (W) direction with a scale. The adhesion was evaluated for spray foaming at room temperature (about 25 ° C.) and for Example 7, spray foaming at a low temperature of 0 ° C. The case where the adhesive strength was high and the adhesiveness was good was rated as “◯”, the case where the adhesive strength was slightly low but practical, and the case where the adhesive strength was low and impractical.

  From the results shown in Table 1, the spray-foamed rigid polyurethane foam using the polyol composition of the present invention is excellent in flame retardancy, physical properties and adhesion to a face material, has good reactivity, and has little occurrence of lateral elongation. It was a thing. Especially Example 7 showed favorable adhesiveness also in the spray foaming in the environment which assumed the winter season of 0 degreeC. On the other hand, when the polyol composition deviated from the scope of the present invention, the performance was generally inferior to that of the present invention. Further, Comparative Examples 1 and 2 had poor adhesion at low temperatures.

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

Claims (5)

A polyol composition comprising a polyol compound, a foaming agent comprising an HFC compound, a foam stabilizer and a catalyst, mixed with a polyisocyanate component by a spray device and reacted to form a rigid polyurethane foam,
The catalyst contains an isocyanurate group-forming catalyst,
100 parts by weight of the polyol compound includes 40 to 80 parts by weight of an aromatic ester polyol having a hydroxyl value of 150 to 450 mgKOH / g and 10 to 40 parts by weight of an aliphatic amine polyol having a hydroxyl value of 350 to 800 mgKOH / g. A polyol composition for spray foamed rigid polyurethane foam.   The spray foamed rigid polyurethane foam according to claim 1, further comprising 10 to 40 parts by weight of Mannich polyol having a hydroxyl value of 250 to 550 mgKOH / g and a functional group number of 2 to 4 in 100 parts by weight of the polyol compound. Polyol composition. A method for producing a rigid polyurethane foam comprising mixing a polyol composition containing a polyol compound, a foaming agent comprising an HFC compound, a foam stabilizer, and a catalyst with a polyisocyanate component and reacting them to form a rigid polyurethane foam,
The catalyst contains an isocyanurate group-forming catalyst,
100 parts by weight of the polyol compound contains 45 to 80 parts by weight of an aromatic ester polyol having a hydroxyl value of 150 to 450 mgKOH / g and 10 to 40 parts by weight of an aliphatic amine polyol having a hydroxyl value of 350 to 800 mgKOH / g. A method for producing a spray foamed rigid polyurethane foam characterized by the following:   The polyol composition further comprises 10 to 40 parts by weight of a Mannich polyol having a hydroxyl value of 250 to 550 mgKOH / g and a functional group number of 2 to 4 in 100 parts by weight of the polyol compound. Manufacturing method of spray foam rigid polyurethane foam.   The spray foamed rigid polyurethane foam according to claim 3 or 4, wherein an equivalent ratio of NCO group / OH group in mixing of the polyol composition and the polyisocyanate component is 1.5 to 2.5. Method.

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