JP2006291124A - Polyol composition for rigid polyurethane foam and method for producing rigid polyurethane foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polyol composition that contains water alone as a blowing agent and produces a rigid polyurethane foam having excellent strength and dimensional stability and to provide a method for producing a rigid polyurethane foam using the polyol composition. <P>SOLUTION: In the polyol composition for a rigid polyurethane foam, which comprises a polyol compound, a blowing agent and a foam stabilizer and is mixed with a polyisocyanate component to form a rigid polyurethane foam, the blowing agent is water and the polyol compound comprises 5-20 wt.% of an adduct of an alkylene oxide to bisphenol A in which 1-3 moles of the total of ethylene oxide and propylene oxide in the molar ratio of 5/5-1/9 (the former/the latter) are added to 1 mol of bisphenol A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyol composition for rigid polyurethane foam for water foaming (hereinafter also simply referred to as a polyol composition) and a method for producing a water foaming rigid polyurethane foam.

  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, chlorofluorocarbon compounds such as CFC-11 were used as foaming agents, but CFC compounds were prohibited because they caused destruction of the ozone layer, and switched to HCFC-141b. Although switching to an HFC compound having a coefficient of zero has been performed, the HFC compound has a problem that it has a large GWP (global warming potential) and is currently expensive.

  Although a technique using pentane such as n-pentane, iso-pentane, cyclopentane or the like as a low-cost blowing agent instead of halogenated hydrocarbon compounds such as HFC compounds is known, pentanes are highly flammable. In addition, there is a problem that a large amount of cost is required for the equipment for fire prevention.

  There is no problem in the working environment and the global environment, and water is known as a low-cost foaming agent, and rigid polyurethane foams using water as a foaming agent are known (Patent Documents 1 to 3).

  The polyol compound which comprises the polyol composition for manufacturing the rigid polyurethane foam disclosed by patent document 1 contains 5 to 40 weight% of polyester polyols. However, since the polyol composition disclosed in Patent Document 1 uses water as a blowing agent, the organotin catalyst cannot be used for hydrolysis, and a tertiary amine catalyst is used. As a result, the polyol composition described in Patent Document 1 containing a polyester polyol as an essential component has a problem that due to the basicity of the amine, the polyester is hydrolyzed and the storage stability is insufficient.

  In addition, the polyol compound constituting the polyol composition for producing the rigid polyurethane foam disclosed in Patent Document 2 is composed of 10 to 50% by weight of polyoxypropylene polyol using sorbitol and propylene glycol as initiators and an aromatic amine polyol. It contains 20 to 30% by weight. However, the rigid polyurethane foam produced by using the polyol composition described in Patent Document 2 is not sufficient in strength and heat insulation properties, and is required to be improved.

  In addition, the polyol compound constituting the polyol composition for producing the rigid polyurethane foam disclosed in Patent Document 3 includes a propylene oxide adduct of bisphenol, an alkylene oxide adduct of toluenediamine, and an alkylene oxide adduct of ethylenediamine. Is contained as an essential component. However, since the rigid polyurethane foam produced using the polyol composition described in Patent Document 3 has insufficient strength, the dimensional change of the product is large immediately after molding or over time, resulting in surface irregularities. The appearance of the foam is inferior.

JP 2003-292560 A Japanese Patent Laid-Open No. 6-239956 JP-A-7-206966

  The present invention provides a polyol composition capable of producing a rigid polyurethane foam containing only water as a foaming agent and having excellent strength and dimensional stability, and a method for producing a rigid polyurethane foam using the polyol composition. For the purpose.

The present invention includes a polyol composition for a rigid polyurethane foam comprising a polyol compound, a foaming agent and a foam stabilizer, and mixed with a polyisocyanate component to form a rigid polyurethane foam.
The blowing agent is water;
The polyol compound is an alkylene oxide adduct of bisphenol A obtained by adding 1 to 3 moles of ethylene oxide and propylene oxide in a molar ratio of 5/5 to 1/9 (the former / the latter) with respect to 1 mole of bisphenol A. The present invention relates to a polyol composition for rigid polyurethane foam, characterized by containing 20% by weight.

  Such a polyol composition uses only water as a foaming agent, and is a polyol composition capable of producing a rigid polyurethane foam excellent in strength and dimensional stability.

  The above-mentioned polyol composition comprises 10 to 40% by weight of a propylene oxide (PO) adduct of ethylenediamine having a hydroxyl value of 500 to 820 mgKOH / g, and ethylene oxide of toluenediamine having a hydroxyl value of 200 to 500 mgKOH / g ( It is preferable to contain 20 to 80% by weight of EO) and propylene oxide (PO) adduct.

  Moreover, it is preferable that the above-mentioned polyol composition contains an amine catalyst and a trimerization catalyst. In particular, the amine catalyst is preferably N, N-dimethylcyclohexylamine, and the trimerization catalyst is preferably potassium octylate and / or a quaternary ammonium salt. By using these catalysts in combination, a high-strength rigid polyurethane foam can be obtained, so that the dimensional stability can be further improved.

Another aspect of the present invention is to produce a rigid polyurethane foam in which a polyol composition containing a polyol compound, a foaming agent and a foam stabilizer and a polyisocyanate component are mixed to form a foamed stock solution composition, and the foamed stock solution composition is foamed and cured. A method,
The blowing agent is water;
The polyol compound is an alkylene oxide adduct of bisphenol A obtained by adding 1 to 3 moles of ethylene oxide and propylene oxide in a molar ratio of 5/5 to 1/9 (the former / the latter) with respect to 1 mole of bisphenol A. It is related with the manufacturing method of the rigid polyurethane foam characterized by containing 20weight%.

  By the manufacturing method having such a configuration, it is possible to manufacture a rigid polyurethane foam having superior dimensional stability as compared with the conventional one using only water as a foaming agent.

  The alkylene oxide adduct of bisphenol A used in the present invention is obtained by adding 1 to 3 moles of EO and PO in a molar ratio of 5/5 to 1/9 (EO / PO) with respect to 1 mole of bisphenol A. is there. EO and PO to be added are preferably 2 to 3 mol in total with respect to 1 mol of bisphenol A. When the total amount of EO and PO to be added is less than 1 mole, the viscosity of the polyol composition becomes high and solids are generated, and it becomes difficult to prepare a uniform foaming stock solution composition. descend. On the other hand, when the total exceeds 3 mol, the strength of the foam becomes insufficient, so that the foam shrinks and deforms immediately after molding or over time. The molar ratio of EO and PO is preferably 4/6 to 2/8. When the molar ratio exceeds 5/5, the strength is insufficient, so that the dimensional change of the product immediately after molding or with time increases, resulting in surface irregularities and the like, and the appearance of the foam deteriorates. On the other hand, when the molar ratio is less than 1/9, since the viscosity is too high, it becomes difficult to prepare a uniform foamed stock solution composition, and the quality of the foam is lowered. In addition, the hydroxyl value of the alkylene oxide adduct of bisphenol A used in the present invention is about 280 to 400 mgKOH / g.

  Moreover, in this invention, the usage-amount of the alkylene oxide adduct of bisphenol A is 5 to 20 weight% in a polyol compound, Preferably it is 5 to 15 weight%. When the amount is less than 5% by weight, the strength of the foam becomes insufficient, and the foam shrinks and deforms immediately after molding or with time, resulting in surface irregularities. On the other hand, when it exceeds 20% by weight, the adhesive strength with the face material becomes low.

  As the polyol compound constituting the polyol composition of the present invention, in addition to the above-mentioned alkylene oxide adduct of bisphenol A, other polyether polyol compounds that do not impair the effects of the present invention are used. Examples of such other polyether polyol compounds include known polyether polyols such as aliphatic amine polyether polyols, aliphatic polyether polyols, aromatic amine polyether polyols, and aromatic polyether polyols.

  Examples of the aliphatic amine-based polyether polyol include alkylene diamine-based polyols and alkanolamine-based 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 and diethanolamine.

  The aliphatic polyether polyol is obtained by ring-opening addition polymerization of at least one of propylene oxide and ethylene oxide to a polyfunctional active hydrogen compound, that is, an aliphatic or alicyclic polyfunctional active hydrogen compound as a polyol initiator. Is a multifunctional oligomer. Examples of the polyol initiator include ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexylene glycol, cyclohexanedimethanol and other glycols, Examples include triols such as methylolpropane and glycerin, tetrafunctional alcohols such as pentaerythritol, polyhydric alcohols such as sorbitol and sucrose, and water.

  The aromatic amine-based polyether polyol is a polyol compound obtained by ring-opening addition of a cyclic ether compound such as ethylene oxide, propylene oxide, butylene oxide using an aromatic diamine as an initiator. As aromatic diamine which is an initiator, well-known aromatic diamine 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. Among these, use of toluenediamine (2,4-toluenediamine, 2,6-toluenediamine, or a mixture thereof) is preferable in that the obtained rigid polyurethane foam has excellent properties such as heat insulation and strength.

  The aromatic polyether polyol is produced by the same method as the above polyether polyol, using an aromatic compound such as hydroquinone or xylylene glycol as an initiator.

  In the present invention, as another polyether polyol compound, 10 to 40% by weight of an ethylenediamine PO adduct having a hydroxyl value of 500 to 820 mgKOH / g, and EO of toluenediamine having a hydroxyl value of 200 to 500 mgKOH / g It is preferable to use 20 to 80% by weight of the PO adduct. The amount of ethylenediamine PO adduct used is more preferably 10 to 30% by weight, and the amount of toluenediamine EO and PO adduct used is more preferably 30 to 80% by weight. The viscosity of the polyol composition can be adjusted to 1000 (mPa · s / 20 ° C.) or less by using the two kinds of polyether polyol compounds in combination at a specific ratio. Thereby, since a uniform foaming stock solution composition can be prepared, the quality deterioration of foam can be prevented.

  You may add a crosslinking agent to the polyol composition 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.

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

  As a catalyst, triethylenediamine, N-methylmorpholine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine, diazabicycloundecene (DBU) It is preferable to use tertiary amines such as N, N-dimethylcyclohexylamine. In particular, it is preferable to use N, N-dimethylcyclohexylamine.

  The use of a trimerization catalyst that forms an isocyanurate bond that contributes to improving the flame retardancy in the structure of the polyurethane molecule is also preferred, and examples include potassium acetate, potassium octylate, and quaternary ammonium salts. As the quaternary ammonium salt, conventionally known quaternary ammonium salts can be used without limitation. For example, tetraalkylammonium halides such as tetramethylammonium chloride, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, tetra Examples include tetraalkylammonium organic acid salts such as methylammonium 2-ethylhexanoate, 2-hydroxypropyltrimethylammonium formate, and 2-hydroxypropyltrimethylammonium 2-ethylhexanoate. Commercially available products can be used as the quaternary ammonium salt-containing catalyst. For example, Kaolizer No. Examples include 400, 410, 420 (manufactured by Kao). 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, it is preferable to use a trimerization catalyst that promotes isocyanurate bond formation and an amine catalyst that promotes urethane bond formation. In particular, it is preferable to use potassium octylate and / or a quaternary ammonium salt as the trimerization catalyst and N, N-dimethylcyclohexylamine as the amine catalyst. When potassium octylate and a quaternary ammonium salt are used in combination as a trimerization catalyst, the blending weight ratio is preferably the former / the latter = 1/2 to 2/1. Moreover, when using together an amine catalyst and a trimerization catalyst, it is preferable that the mixture weight ratio is an amine catalyst / trimerization catalyst = 6/1-2/1, More preferably, it is 5/1-3/1. is there.

  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. .

  However, when an excessive amount of powdery flame retardant such as antimony trioxide is added excessively, there may be a problem that the foaming behavior of the foam is affected.

  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 amount of the organic phosphate ester added is preferably 10 to 30 parts by weight with respect to 100 parts by weight of the total polyol compound. If it exceeds this range, the plasticizing effect and the flame retardant effect cannot be obtained sufficiently, and the mechanical properties of the foam tend to be lowered.

  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. Therefore, it is preferable to use liquid MDI. As liquid MDI, Crude MDI (c-MDI) (Sumijoule 44V-10, Sumijoule 44V-20, etc. (manufactured by Sumitomo Bayer Urethane Co., Ltd.), Millionate MR-200 (Nippon Polyurethane Industry)), uretonimine-containing MDI (Millionate MTL) Manufactured by Nippon Polyurethane Industry) or the like. In addition to liquid MDI, other polyisocyanate compounds may be used in combination. As the polyisocyanate compound to be used in combination, polyisocyanate compounds well known in the technical field of polyurethane can be used without limitation.

  In the production of the rigid polyurethane foam of the present invention, the equivalent ratio (NCO index) of isocyanate groups to active hydrogen groups is 1 to 2, more preferably 1.5 to 2.

  The polyol composition and rigid polyurethane foam production method of the present invention can be used for production of continuously produced foams such as slabstock foams and sandwich panels.

  The method for producing a rigid polyurethane foam of the present invention will be described by taking as an example the production of a heat insulating panel in which paper materials are laminated on both sides. In the method for producing a rigid polyurethane foam of the present invention, a face material supply device, a conveyor device, a polyol composition and a polyisocyanate component, which are generally used for producing a slab foam or a sandwich panel, are mixed on the bottom material. A known continuous foaming apparatus equipped with a foaming machine (mixer) to be fed to a heating oven, a heating oven, and a cutting machine for cutting a rigid polyurethane foam formed into a continuous shape into an appropriate length can be used.

The manufacturing process of the sandwich panel is generally composed of the following processes.
1) The lower sheet surface material is rewound from the original roll and supplied to the conveyor.
2) A foaming stock solution composition formed by mixing a polyol composition and a polyisocyanate component in a foaming machine on a lower paper surface material is uniformly supplied in the width direction of the paper surface material.
3) Supply the upper paper surface material. After supplying the top surface material, it passes through a nip device such as a nip roll to diffuse the foamed stock solution composition in the width direction, make the thickness of the solution uniform, and make the top and bottom surface material and the foamed stock solution composition compatible.
4) It is sent to a heating oven and heated to cause a foaming / curing reaction, thereby obtaining a rigid polyurethane foam having paper materials laminated on both sides. In order to obtain a predetermined thickness, a double conveyor that holds the upper and lower surfaces of the foam may be used.
5) The rigid polyurethane foam continuously coming out of the heating oven is cut into a predetermined length by a cutting machine.

<Evaluation / Measurement>
[Evaluation of compatibility (stirring property) of polyol composition and polyisocyanate component]
The state at the time of mixing and stirring was visually observed and judged according to the following criteria.
○: Stirring property is good (equivalent to or higher than when HFC compound is used).
Δ: Stirring property is slightly poor. The foam can be formed but the cells are rough.
X: Stirring property is poor. The foam can be formed, but the cells are very rough and charge occurs.

[Measurement of viscosity of polyol composition]
The viscosity (mPa · s / 20 ° C.) of a polyol composition not containing a blowing agent having a liquid temperature of 20 ° C. was measured with a B-type viscometer.

[Evaluation of dimensional stability]
A foam sample obtained by cutting a free-foam foam into 100 mm squares was stored for 24 hours under the condition of -20 ° C., and a rate of change in thickness was measured to obtain a dimensional change rate. The evaluation results are indicated by ◯ when the dimensional change rate is less than 1%, Δ when 1 to 3%, and x when more than 3%.

[Evaluation of flame retardancy]
A foam sample of 100 mm square was cut out from the free foamed foam, the tip of the sample was brought into contact with the tip of a propane gas Bunsen burner adjusted to 20 mm in inner flame height and 38 mm in outer flame for 10 seconds. Whether or not was burned was observed visually. The case where the foam did not burn was evaluated as ◯, the case where ignition was performed but the combustion was not sustained was evaluated as Δ, and the case where the foam was burned was evaluated as x.

[Measurement of adhesive strength with face material]
A notch with a width of 5 cm is formed on the face material of the produced rigid polyurethane foam panel, the face material from which the end has been peeled is pulled with a spring balance at a peel angle of 45 °, and the peel strength at that time (g / 5 cm width) is measured. did.

(Measurement of thermal conductivity)
The thermal conductivity (W / mk) of the rigid polyurethane foam was measured using a thermal conductivity measuring device AUTO-Λ HC-074 (manufactured by Eihiro Seiki Co., Ltd.), and the measurement conditions were measured according to JIS A 9511.

[Evaluation of foam strength]
The hardness of the cross section of the produced rigid polyurethane foam panel was evaluated according to the following criteria by tactile sensation.
○: Hardness equivalent to or higher than foam (current product) using HFC compound.
(Triangle | delta): It is a slightly low hardness compared with the foam (present product) using a HFC compound.
X: The hardness is considerably lower than that of the foam using the HFC compound (current product), and the shrinkage is large.
<Example of production of polyol composition and rigid polyurethane foam>
(Raw materials used)
[Polyol compound]
Polyol A: EO adduct of ethylenediamine (hydroxyl value 450 mgKOH / g)
Polyol B: PO adduct of ethylenediamine (hydroxyl value 760 mgKOH / g)
Polyol C: EO and PO adduct of toluenediamine (hydroxyl value 450 mgKOH / g)
Polyol D: Aromatic polyester (hydroxyl value 260 mgKOH / g)
Polyol E: PO adduct of sucrose (hydroxyl value 450 mgKOH / g)
Polyol F: EO (1 mol) adduct of bisphenol A (hydroxyl value 412 mgKOH / g)
Polyol H: bisphenol A EO and PO (EO / PO = 2/8, 3 mol in total) adduct (hydroxyl value 284 mgKOH / g)
Polyol I: PO (6 mol) adduct of bisphenol A (hydroxyl value 194 mg KOH / g)
Polyol J: PO (4 mol) adduct of bisphenol A (hydroxyl value 243 mg KOH / g)
Polyol K: EO (4 mol) adduct of bisphenol A (hydroxyl value 280 mgKOH / g)
Polyol L: Bisphenol A EO (3 mol) adduct (hydroxyl value 310 mgKOH / g)
[Flame retardants]
・ TMCPP: Phosphorus flame retardant (plasticizer) (Daihachi Chemical Industry)
[Foam stabilizer]
SH-193: Silicon-based surfactant (Toray Dow Corning Silicon)
[Amine catalyst]
・ N, N-dimethylcyclohexylamine (PC-8, manufactured by Sun Abbott)
[Trimerization catalyst]
・ Potassium octylate (Perlon 9540)
・ Quaternary ammonium salt (Kao No. 410, manufactured by Kao Corporation)
[Polyisocyanate]
・ C-MDI (MR-200, manufactured by Nippon Polyurethane)
(Examples and Comparative Examples)
According to a conventional method, the polyol composition is first adjusted based on the composition shown in Table 1 to adjust the temperature to 20 ° C., and then mixed with a polyisocyanate component that is also temperature adjusted to 20 ° C. to obtain a foamed stock solution composition. (Cure at 70 ° C. for 2 minutes) to prepare a rigid polyurethane foam panel having a thickness of 60 mm. The numerical values in Table 1 indicate parts by weight.

Claims (5)

In a polyol composition for a rigid polyurethane foam comprising a polyol compound, a foaming agent and a foam stabilizer, and mixed with a polyisocyanate component to form a rigid polyurethane foam,
The blowing agent is water;
The polyol compound is an alkylene oxide adduct of bisphenol A obtained by adding 1 to 3 moles of ethylene oxide and propylene oxide in a molar ratio of 5/5 to 1/9 (the former / the latter) with respect to 1 mole of bisphenol A. A polyol composition for rigid polyurethane foam, comprising 20% by weight.   The polyol compound comprises 10 to 40% by weight of a propylene oxide adduct of ethylenediamine having a hydroxyl value of 500 to 820 mgKOH / g, and an ethylene oxide and propylene oxide adduct of toluenediamine having a hydroxyl value of 200 to 500 mgKOH / g. The polyol composition for rigid polyurethane foam according to claim 1, which is contained in an amount of 20 to 80% by weight.   The polyol composition for rigid polyurethane foam according to claim 1 or 2, comprising an amine catalyst and a trimerization catalyst.   The polyol composition for rigid polyurethane foam according to claim 3, wherein the amine catalyst is N, N-dimethylcyclohexylamine, and the trimerization catalyst is potassium octylate and / or a quaternary ammonium salt. A method for producing a rigid polyurethane foam comprising mixing a polyol composition containing a polyol compound, a foaming agent and a foam stabilizer and a polyisocyanate component to form a foamed stock solution composition, and foaming and curing the foamed stock solution composition,
The blowing agent is water;
The polyol compound is an alkylene oxide adduct of bisphenol A obtained by adding 1 to 3 moles of ethylene oxide and propylene oxide in a molar ratio of 5/5 to 1/9 (the former / the latter) with respect to 1 mole of bisphenol A. A method for producing a rigid polyurethane foam, comprising 20% by weight.