JP4461417B2 - Polyisocyanate composition and method for producing rigid polyurethane foam - Google Patents

Description

The present invention relates to a polyisocyanate composition, a method for preparing the same, and a method for producing a rigid polyurethane foam. More specifically, a polyisocyanate composition capable of producing a rigid polyurethane foam having high adhesion to an adherend, a method for preparing such a polyisocyanate composition, and a rigid polyurethane foam produced using such a polyisocyanate composition. It relates to a manufacturing method.
In the present invention, “rigid polyurethane foam” is a concept including “isocyanurate-modified polyurethane foam” unless otherwise specified.

Conventionally, rigid polyurethane foam has been widely used as a heat insulating material for refrigerators, refrigerated warehouses, building materials and the like, and for spray applications.
Polymeric MDI (polyphenylene polymethylene polyisocyanate) including MDI (diphenylmethane diisocyanate) is used as the polyisocyanate in producing the rigid polyurethane foam.

On the other hand, as a foaming agent for producing a rigid polyurethane foam, (hydro) chlorofluorocarbons such as 1,1-dichloro-1-fluoroethane, which has been widely used in the past, from the viewpoint of preventing destruction of the ozone layer, etc. Instead, 1,1,1,3,3-pentafluoropropane (hereinafter abbreviated as “HFC-245fa”), 1,1,1,3,3-pentafluorobutane (hereinafter, “HFC-365mfc”). Hydrofluorocarbons such as “.” Are being used.
In addition, a rigid polyurethane foam having a (complete) water foaming formulation that uses only water as a foaming agent has also been introduced (see, for example, Patent Document 1).

However, hydrofluorocarbons and water used as blowing agents are more homogeneously mixed (compatible and dispersible) with urethane raw materials (isocyanate composition and polyol composition) than conventional (hydro) chlorofluorocarbons. There is a problem of being inferior. If the uniform mixing property (compatibility / dispersibility) between the foaming agent and the urethane raw material is low, the reactivity and foaming efficiency (densification) will decrease, resulting in poor surface finish, reduced strength, In addition to a decrease in dimensional stability and a decrease in heat insulation due to cell roughness, there is a problem in that the adhesive force of the foam to the adherend (casing) decreases.
Moreover, the rigid polyurethane foam by a water foaming prescription | regulation does not have sufficient adhesive force with respect to a to-be-adhered body.
Here, the decrease in the adhesive force to the adherend becomes a problem particularly in spraying construction (spraying construction) performed in a low temperature environment.

The following methods have been introduced as methods for improving the adhesion of rigid polyurethane foam to an adherend.
(1) As a polyol component, ethylene oxide (EO) and propylene oxide (PO) adducts of tolylenediamine, PO adducts of triethanolamine, PO adducts of glycerin, EO and PO adducts of ethylenediamine, EO of glycerin and A method of using a polyol mixture obtained by mixing a PO adduct (see Patent Document 2).
(2) Method of using polymeric MDI with a high ratio of isomers (isomers of MDI other than 4,4′-MDI) as a polyisocyanate component while adding imidazoles to the polyol composition (see Patent Document 3) ).
(3) A method in which a polyol having a low functional group number and a low hydroxyl value is used as the polyol component, and polymeric MDI having a high isomer ratio is used as the polyisocyanate component (see Patent Document 4).

However, conventionally known methods, including the above methods (1) to (3), cannot produce a rigid polyurethane foam having a sufficiently high adhesion to various adherends.
JP-A-3-91522 JP-A-6-316621 JP-A-6-172485 JP-A-10-204149

The present invention has been made based on the above situation.
The first object of the present invention is to provide a polyisocyanate composition capable of producing a rigid polyurethane foam having good adhesion to various adherends and having a low shrinkage ratio and excellent shape stability. To provide things.
The second object of the present invention is to provide a polyisocyanate composition excellent in uniform mixing properties (compatibility / dispersibility) with hydrofluorocarbons and / or water.
The third object of the present invention is to produce a rigid polyurethane foam having high foam strength, excellent adhesion and dimensional stability, etc., by a foaming formulation using hydrofluorocarbons and / or water as a foaming agent. The object is to provide a polyisocyanate composition.
The fourth object of the present invention is to provide a method for preparing a polyisocyanate composition having excellent performance as described above.
A fifth object of the present invention is to provide a method for producing a rigid polyurethane foam having good adhesion to various adherends and having a low shrinkage ratio and excellent shape stability. . A sixth object of the present invention is to provide a method for producing a rigid polyurethane foam having high foam strength and excellent adhesion and dimensional stability.

The polyisocyanate composition of the present invention is a polyisocyanate composition used for producing a rigid polyurethane foam formed on an adherend by a spray method by a foaming formulation using hydrofluorocarbons and water as a foaming agent. There,
(A0) Polymeric MDI in which the proportion of MDI is 20.0-80.0% ,
(A1) Polyester polyol (a1) having a sulfo group or a sulfonate group in the molecular structure of polymeric MDI having a MDI ratio of 20.0 to 80.0% [hereinafter referred to as “specific polyester polyol (a1)” . A first isocyanate group-terminated prepolymer obtained by reacting
(A2) a second isocyanate group-terminated prepolymer obtained by reacting a polyether monool (a2) with a polymeric MDI having a MDI content of 20.0 to 80.0% ,
(A3) a silicone-based foam stabilizer , and
(A4) a liquid ester compound that is liquid at room temperature ,
The ratio of the first isocyanate group-terminated prepolymer (A1) to the total amount of the isocyanate compound is 0.05 to 5.0% by mass .

The production method of the present invention is a method of producing a rigid polyurethane foam formed on an adherend by a spray method using the polyisocyanate composition of the present invention, the polymer MDI (A0), 1 is a hydrofluorocarbon as a blowing agent (C) comprising a polyisocyanate mixture (A) containing the isocyanate group-terminated prepolymer (A1) and the second isocyanate group-terminated prepolymer (A2), and a polyol (B). And water , the catalyst (D) , the foam stabilizer (E) , and the silicone foam stabilizer (A3) and the liquid ester compound (A4) which are components of the polyisocyanate composition. It is characterized by that .

(1) According to the polyisocyanate composition of the present invention, a rigid polyurethane foam having good adhesion to various adherends and having a low shrinkage ratio and excellent shape stability is produced. be able to.
(2) The polyisocyanate composition of the present invention is excellent in uniform mixing properties (compatibility / dispersibility) with hydrofluorocarbons and / or water. Thereby, even if it uses hydrofluorocarbons and / or water as a foaming agent, the problem resulting from poor mixing with these foaming agents does not arise.
(3) According to the polyisocyanate composition of the present invention, a homogeneous rigid polyurethane having high foam strength, excellent adhesiveness and dimensional stability, etc., by a foaming formulation using hydrofluorocarbons and / or water as a foaming agent. A foam can be produced.
(4) According to the preparation method of the present invention, a polyisocyanate composition having excellent performance as shown in the above (1) to (3) can be reliably prepared.
(5) According to the production method of the present invention, it is possible to reliably produce a rigid polyurethane foam having good adhesion to various adherends and having a low shrinkage ratio and excellent shape stability. Can do.
(6) According to the production method of the present invention, it is possible to reliably produce a rigid polyurethane foam having high foam strength and excellent adhesion and dimensional stability.

  In the polyisocyanate composition of the present invention, polymeric MDI (A0), first isocyanate group-terminated prepolymer (A1), second isocyanate group-terminated prepolymer (A2) and silicone-based foam stabilizer (A3) are essential. It is contained as a component.

<Polymeric MDI (A0)>
The polymeric MDI (A0) constituting the polyisocyanate composition of the present invention is a mixture (polyphenylene polymethylene poly) of binuclear MDI (diphenylmethane diisocyanate) and a trinuclear or higher polynuclear (MDI condensate). Isocyanate).
Polymeric MDI (A0) can be obtained by converting the amino group of a condensation mixture (polyamine) obtained by the condensation reaction of aniline and formalin to an isocyanate group by phosgenation or the like. By changing the reaction conditions, the composition (nuclear distribution and isomer composition ratio) of the finally obtained polymeric MDI can be controlled.
The polymeric MDI (A0) used in the present invention is a reaction solution such as a reaction solution after conversion to an isocyanate group, removal of the solvent from the reaction solution, a bottom solution obtained by partially distilling and separating MDI, and the like. It may be a mixture of several different types. Moreover, what mixed MDI with the commercially available polymeric MDI may be used.

The proportion of MDI (binuclear body) in the polymeric MDI (A0) is preferably 20.0 to 80.0%, more preferably 25.0 to 75.0%.
Here, the ratio of MDI is a ratio determined from the peak area ratio of MDI by GPC (gel permeation chromatography).
When the proportion of MDI in the polymeric MDI (A0) exceeds 80.0%, the adhesive strength and strength of the rigid polyurethane foam to be finally formed on the adherend tend to be lowered.
On the other hand, when this ratio is less than 20.0%, the viscosity of the obtained polyisocyanate composition is increased, and for example, spray operation in spraying is likely to be difficult.

MDI, which is a binuclear body, is composed of three isomers of 4,4′-MDI, 2,2′-MDI, and 2,4′-MDI.
The constitutional ratio of these isomers is not particularly limited, but the content ratio of 4,4′-MDI is 50.0 to 99.5 mass from the viewpoint of forming a rigid polyurethane foam having high adhesion and strength to the adherend. It is preferable that
The composition ratio of isomers can be determined from a calibration curve based on the area percentage of each peak obtained by GPC or GC (gas chromatography).

The average number of functional groups of the polymeric MDI (A0) is preferably 2.2 or more, and more preferably 2.2 to 3.1.
The isocyanate content of the polymeric MDI (A0) is preferably 28 to 33% by mass, more preferably 28.5 to 32.5% by mass.
The acidity of the polymeric MDI (A0) is preferably 0.001 to 0.2% by mass, and more preferably 0.003 to 0.15% by mass. Thereby, the storage stability and suitable reactivity of the polyisocyanate composition obtained are ensured.
The “acidity” means a value obtained by converting an acid component that reacts with alcohol at room temperature and liberated into hydrogen chloride, and is measured according to JIS K-1603.

<First isocyanate group-terminated prepolymer (A1)>
The first isocyanate group-terminated prepolymer (A1) constituting the polyisocyanate composition of the present invention imparts or improves good adhesion to various adherends to the finally formed rigid polyurethane foam. It is a component to be made.

The first isocyanate group-terminated prepolymer (A1) can be obtained by reacting a specific polyester polyol (a1) with polymeric MDI.
The “polymeric MDI” subjected to the reaction for obtaining the first isocyanate group-terminated prepolymer (A1) is the “polymeric MDI (A0)” (binuclear compound) described above as a constituent of the polyisocyanate composition. A mixture with a trinuclear or higher polynuclear body), and the description thereof is omitted.

<Specific polyester polyol (a1)>
The “specific polyester polyol (a1)” subjected to the reaction for obtaining the first isocyanate group-terminated prepolymer (A1) has a sulfo group (—SO ₃ H) or a sulfonate group (—SO ₃ ⁻ ) as a molecule. This is a polyester polyol in the structure.

  The specific polyester polyol (a1) is a polybasic acid (hereinafter referred to as “specific polybasic acid”) or a polybasic acid ester (hereinafter referred to as “specific polybasic acid ester”) having a sulfo group or a sulfonate group in the molecular structure. Can be obtained by esterification (or transesterification) according to a conventional method.

  Examples of the “specific polybasic acid” include 2-sodium sulfoterephthalic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, and 5-lithium sulfoisophthalic acid. can do.

  Examples of the “specific polybasic acid ester” include esterified products of these specific polybasic acids (esters having 1 or more carbon atoms such as methyl ester, ethyl ester, propyl ester, butyl ester).

  Polybasic acids other than specific polybasic acids include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, peric acid, sebacic acid, azelaic acid, dodecanoic acid, fumaric acid. Examples of the acid, maleic acid, malic acid, tartaric acid and the like, and examples of the aromatic dicarboxylic acid include orthophthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid.

  Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, hydrogenated bisphenol A, and 1,2-propanediol. 1,2-butanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,6-hexanediol, 2-ethyl-1,3-hexane Diol, 2-ethyl-2-butyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 3,3-dimethyl-1,5-pentanediol, 2-methyl-2-ethyl -1,3-propanediol, 3-methyl-3-ethyl-1,5-pentanediol, 2-methyl-2 Propyl-1,3-propanediol, 3-methyl-3-propyl-1,5-pentanediol, 2-methyl-2-butyl-1,3-propanediol, 3-methyl-3-butyl-1,5 -Pentanediol, 3,3-diethyl-1,5-pentanediol, 3-ethyl-3-butyl-1,5-pentanediol, 2-ethyl-2-propyl-1,3-propanediol, 3-ethyl -3-propyl-1,5-pentanediol, 2,2-dibutyl-1,3-propanediol, 3,3-dibutyl-1,5-pentanediol, 2,2-dipropyl-1,3-propanediol 3,3-dipropyl-1,5-pentanediol, 2-butyl-2-propyl-1,3-propanediol, 3-butyl-3-propyl-1,5-pentanedio 2-ethyl-1,3-propanediol, 2-propyl-1,3-propanediol, 2-butyl-1,3-propanediol, 3-ethyl-1,5-pentanediol, 3-propyl- 1,5-pentanediol, 3-butyl-1,5-pentanediol, 2-ethyl-1,6-hexanediol, 2-propyl-1,6-hexanediol, 2-butyl-1,6-hexanediol 5-ethyl-1,9-nonanediol, 5-propyl-1,9-nonanediol, 5-butyl-1,9-nonanediol, dipropylene glycol, triethylene glycol, tetramethylene glycol, hexamethylene glycol, Decamethylene glycol, glycerin, trimethylolpropane, pentaerythlit, sorbit, etc. be able to.

  The number average molecular weight of the specific polyester polyol (a1) is preferably 500 to 3000, more preferably 800 to 2500.

  If the number average molecular weight is too small, the resulting polyurethane foam itself becomes brittle. On the other hand, when the number average molecular weight is excessive, the compatibility with polymeric MDI (isocyanate compound) is deteriorated.

  The ratio of the sulfo group or sulfonate group contained in the specific polyester polyol (a1) is preferably 0.1 to 2.0 mmol / g, more preferably 0.1 to 1.5 mmol / g. The

  When the ratio of the sulfo group or the sulfonate group is too small, the adhesive effect as desired in the present invention is not exhibited. On the other hand, when this ratio is excessive, compatibility with polymeric MDI (isocyanate compound) is deteriorated. This ratio can be controlled by adjusting the ratio of the specific polybasic acid (ester) in the polybasic acids subjected to the reaction.

  An example of a preferable compound as the specific polyester polyol (a1) is a polybasic acid composed of 5-sodium sulfoisophthalic acid (or dimethyl 5-sodium sulfoisophthalate) and adipic acid, and 1,6-hexanediol. Mention may be made of sodium sulfonate group-containing adipate polyester polyols having a number average molecular weight of 1000 to 2000, which are obtained by esterification reaction (transesterification reaction and ester reaction).

<Second isocyanate group-terminated prepolymer (A2)>
The second isocyanate group-terminated prepolymer (A2) is a component that imparts to the polyisocyanate composition of the present invention uniform mixing with a foaming agent (particularly, a foaming agent composed of hydrofluorocarbons and / or water). .

A 2nd isocyanate group terminal prepolymer (A2) is obtained by making polyether monool (a2) react with polymeric MDI.
The “polymeric MDI” subjected to the reaction for obtaining the second isocyanate group-terminated prepolymer (A2) is the “polymeric MDI (A0)” (binuclear compound) described above as a constituent of the polyisocyanate composition. A mixture with a trinuclear or higher polynuclear body), and the description thereof is omitted.

<Polyether monool (a2)>
The “polyether monool (a2)” subjected to the reaction for obtaining the second isocyanate group-terminated prepolymer (A2) can be represented by the following chemical formula.

Chemical formula: R ¹ O— (R ² O) _n —H

In the above chemical formula, R ¹ represents a monovalent organic group, — (R ² O) — represents an alkylene oxide group, and n represents a number of 2 or more.
The organic group (R ¹ ) may have an atom other than a carbon atom and a hydrogen atom, and it does not matter whether a side chain is present. In addition, a plurality of alkylene oxide groups — (R ² O) — may be the same or different.

The polyether monool (a2) can be obtained by adding a cyclic ether such as alkylene oxide to a compound having one hydroxyl group (R ¹ OH) as an initiator.

Examples of the compound represented by R ¹ OH used as an initiator include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2-ethylhexyl alcohol, phenol, benzyl alcohol, N-methyl- Examples thereof include N-ethylamino alcohol and N, N-diethylamino alcohol.
Examples of the alkylene oxide added to the initiator include ethylene oxide, propylene oxide, and butylene oxide.

The number average molecular weight of the polyether monool (a2) is preferably 150 to 10,000, and more preferably 150 to 8,000.
When the number average molecular weight of the polyether monool (a2) is excessively small, the effect of improving uniform mixing with a foaming agent (particularly, a foaming agent comprising hydrofluorocarbons and / or water) should be sufficiently exerted. I can't. On the other hand, when the number average molecular weight is excessive, the viscosity of the resulting polyisocyanate composition increases, resulting in a decrease in workability.

One example of a preferred compound as a polyether monol (a2), have a alkoxy group having 1 to 20 carbon atoms as terminal groups (R ¹ O-), repeating units as [- - (R ² O) _n] Poly (oxyethylene) monool, poly (oxypropylene) monool, poly (oxyethylene-oxypropylene) copolymer mono having an oxyethylene group and / or an oxypropylene group and having a number average molecular weight of 500 to 1,000 All can be mentioned.

<Silicone-based foam stabilizer (A3)>
The silicone-based foam stabilizer (A3) constituting the polyisocyanate composition of the present invention is not particularly limited, and conventionally known foam stabilizers for rigid polyurethane foams (dimethylpolysiloxane and polysiloxane- Polyether copolymers) can all be used.

As part or all of the silicone-based foam stabilizer (A3), a polysiloxane-polyether copolymer containing active hydrogen groups (hereinafter referred to as “active hydrogen group-containing silicone”) may be used.
According to the polyisocyanate composition of the present invention containing an active hydrogen group-containing silicone-based foam stabilizer, uniform mixing with a foaming agent (particularly, compatibility with a foaming agent composed of hydrofluorocarbons and / or water). , Dispersibility of the foaming agent in the composition) can be further improved.

The active hydrogen group-containing silicone is a block copolymer comprising a dimethylpolysiloxane structure and a polyoxyalkylene structure (polyether structure), and is a compound having an active hydrogen group in the molecular structure.
Preferred examples of the active hydrogen group include a hydroxyl group, an amino group, a carboxyl group, and a mercapto group. A hydroxyl group is most preferred from the viewpoint of viscosity, compatibility, dispersibility, and the like of the resulting polyisocyanate composition.

  The average number of functional groups (average number of active hydrogen groups in one molecule) of the active hydrogen group-containing silicone is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 2. When the average number of functional groups is too large, the resulting polyisocyanate composition has a high viscosity, and the workability during foaming tends to decrease.

  The number average molecular weight of the active hydrogen group-containing silicone is preferably 500 to 20,000, and more preferably 1,000 to 18,000. Those having an excessive number average molecular weight have high viscosity and poor handleability.

  The hydroxyl value of the active hydrogen group-containing silicone is preferably 3 to 300 mgKOH / g, more preferably 5 to 150 mgKOH / g. When the hydroxyl value is excessively low, the viscosity is high and the handleability is poor, and the formed foam does not have sufficient strength. On the other hand, when the hydroxyl value is excessive, the resulting polyisocyanate composition cannot sufficiently improve the uniform mixing property with the foaming agent.

  The following general formulas (1) to (9) show specific structures of the active hydrogen group-containing silicone.

(In the formula, A represents an active hydrogen group, R ³ represents a divalent organic group having a polyether structure, R ⁴ represents a monovalent organic group, and m is an integer of 2 or more.)

(In the formula, A represents an active hydrogen group, R ³ represents a divalent organic group having a polyether structure. M is an integer of 2 or more.)

(In the formula, A represents an active hydrogen group, R ³ represents a divalent organic group having a polyether structure, R ⁴ represents a monovalent organic group, and R ⁵ represents a trivalent organic group. m is an integer of 2 or more.)

(In the formula, A represents an active hydrogen group, R ³ represents a divalent organic group having a polyether structure, R ⁴ represents a monovalent organic group, and R ⁵ represents a trivalent organic group. m is an integer of 2 or more.)

(The above formula represents a block copolymer or a random copolymer. In the formula, A represents an active hydrogen group, R ³ represents a divalent organic group having a polyether structure, and R ⁴ represents a monovalent group.) Represents an organic group, m and n are integers of 1 or more.)

(The above formula represents a block copolymer or a random copolymer. In the formula, A represents an active hydrogen group, R ³ represents a divalent organic group having a polyether structure, and R ⁴ represents a monovalent group.) Represents an organic group, m and n are integers of 1 or more.)

(Above formula in. Formula showing a block copolymer or random copolymer, A is shows the active hydrogen group, R ³ is .m showing a divalent organic group having a polyether structure, n represents 1 or more Is an integer.)

(The above formula represents a block copolymer or a random copolymer. In the formula, A represents an active hydrogen group, R ³ represents a divalent organic group having a polyether structure. R ⁴ represents a monovalent group.) An organic group, R ⁵ represents a trivalent organic group, and m and n are integers of 1 or more.)

(The above formula represents a block copolymer or a random copolymer. In the formula, A represents an active hydrogen group, R ³ represents a divalent organic group having a polyether structure, and R ⁴ represents a monovalent group.) an organic group, R ⁵ is .m showing a trivalent organic radical, n is an integer of 1 or more.)

<Other isocyanate compounds>
The polyisocyanate composition of the present invention contains polymeric MDI (A0), the first isocyanate group-terminated prepolymer (A1) and the second isocyanate group-terminated prepolymer (A2) as essential isocyanate compounds. The polyisocyanate composition may contain an isocyanate compound other than these essential isocyanate compounds.
As such an isocyanate compound, a urethanized product obtained by reacting a polymeric MDI (or only MDI) with an active hydrogen group-containing compound (the first isocyanate group-terminated prepolymer and the second isocyanate group-terminated prepolymer) Excludes applicable)), urea compound, allophanate compound, biuret compound, carbodiimide compound, ureton iminate compound, uretdione compound, isocyanurate compound; 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylene-1, Aromatic diisocyanates such as 4-diisocyanate, xylene-1,3-diisocyanate, tetramethylxylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate; tetramethylene diisocyanate Alicyclic diisocyanates such as isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. Can be mentioned. In addition, urethanized products, urea compounds, allophanate compounds, biuret compounds, carbodiimide compounds, uretoniminate compounds, uretdione compounds, isocyanurate compounds, etc. obtained by reacting these polymeric substances and these isocyanates with active hydrogen group-containing compounds. It can also be used. These isocyanate compounds can be used alone or in combination of two or more.

<Proportion of first isocyanate group-terminated prepolymer (A1)>
In the polyisocyanate composition of the present invention, the total amount of the isocyanate compound [polymeric MDI (A0), the essential isocyanate compound comprising the first isocyanate group-terminated prepolymer (A1) and the second isocyanate group-terminated prepolymer (A2), In addition, the ratio of the first isocyanate group-terminated prepolymer (A1) to the total amount of isocyanate compounds other than these essential isocyanate compounds is preferably 0.05 to 5.0% by mass.
Thereby, it is possible to reliably produce a rigid polyurethane foam having good adhesion to various adherends and having a low shrinkage ratio and excellent shape stability.

<Liquid ester compound (A4)>
The polyisocyanate composition of the present invention preferably contains a liquid ester compound (A4). The “liquid ester compound (A4)” is an ester compound that is liquid at room temperature.
Here, the “ester compound” includes all compounds having a molecular structure in which a hydrogen atom of an organic acid or an inorganic acid is substituted with an organic group (R).
The liquid ester compound (A4) has an action of reducing the viscosity of the polyisocyanate composition containing the liquid ester compound (A4), and can further improve the adhesive force of the rigid polyurethane foam formed thereby to the adherend.
Specific examples of the liquid ester compound (A4) include carboxylic acid ester compounds such as ethyl acetate, butyl acetate, dibutyl phthalate, dimethyl adipate, and ε-caprolactone; carbonates such as dimethyl carbonate, diethyl carbonate, and propylene carbonate ( Carbonate ester) compounds; phosphate (phosphate ester) compounds such as trimethyl phosphate and triethyl phosphate, and the like. Among these, cyclic carbonate compounds are preferred.

<Optional component>
The polyisocyanate composition of the present invention may contain various optional components as long as the effect is not impaired.
As such optional components, all conventionally known substances (such as additives) can be used as those contained in the polyisocyanate composition for producing a rigid polyurethane foam.

<Polyisocyanate composition>
The isocyanate content of the polyisocyanate composition of the present invention is preferably 25.0 to 32.0 mass%, more preferably 26.0 to 32.0 mass%.
The viscosity (25 ° C.) of the polyisocyanate composition of the present invention is preferably 50 to 400 mPa · s, more preferably 60 to 300 mPa · s.
Since the polyisocyanate composition of the present invention is excellent in homogeneous mixing with hydrofluorocarbons and water (compatibility / dispersibility of hydrofluorocarbons and water in the composition), a foaming formulation using these as a foaming agent It is preferably used to produce rigid polyurethane foams according to
According to the polyisocyanate composition of the present invention, the conventionally known polyisocyanate composition can be applied in spraying construction (spray construction) in a low-temperature environment that could not be applied from the viewpoint of adhesiveness. A rigid polyurethane foam having good adhesion to the body can be formed.
Here, the adherend to which the polyisocyanate composition of the present invention is applied is not particularly limited, and examples thereof include woods, concretes, various metals, papers, stones, various plastics, and ceramics. , Glass and various rubbers.
In addition, as a use aspect (construction method) of the polyisocyanate composition of this invention, of course, it is not limited to spray construction.

<Method for preparing polyisocyanate composition>
The preparation method of the present invention is a method for preparing the polyisocyanate composition of the present invention. In the presence or absence of the silicone foam stabilizer (A3), the polyester polyol (a1) specific to the polymeric MDI. To synthesize the first isocyanate group-terminated prepolymer (A1) and to synthesize the second isocyanate group-terminated prepolymer (A2) by reacting the polyether monool (a2) with the polymeric MDI. Including.

Here, the synthesis reaction of the first isocyanate group-terminated prepolymer (A1) and the synthesis reaction of the second isocyanate group-terminated prepolymer (A2) may be performed in advance, and these are performed simultaneously. May be.
Further, one and / or the other of these synthetic reactions is performed in the presence of the silicone-based foam stabilizer (A3) (that is, the silicone-based foam stabilizer (A3) and the reaction raw material are mixed and reacted). Can also be performed in the absence of the silicone-based foam stabilizer (A3) (that is, the silicone-based foam stabilizer (A3) is mixed in the system after the reaction).

  In the preparation method of the present invention, a specific polyester polyol (a1) and / or polyether monool (a2) and an excessive amount of polymeric MDI are usually charged into a reaction vessel, and the specific polyester polyol (a1) is prepared. ) And / or polyether monool (a2) is reacted with polymeric MDI (part of charge).

In the preparation method of the present invention, the mass ratio [polymeric MDI: (a1) :( a2)] of the polymeric MDI charged into the reaction vessel, the polyester polyol (a1), and the polyether monool (a2) is 90. It is preferably 0 to 99.98: 0.01 to 5.0: 0.01 to 5.0, more preferably 92.0 to 99.9: 0.05 to 4.0: 0.05. 4.0, particularly preferably 94.0-99.8: 0.10-3.0: 0.10-3.0.
In addition, when the synthesis reaction of the first isocyanate group-terminated prepolymer (A1) and the synthesis reaction of the second isocyanate group-terminated prepolymer (A2) are carried out separately, the amount “charged in the reaction vessel” Is the total amount of each charge.

The reaction temperature in the synthesis reaction (urethanization reaction) for obtaining the first isocyanate group-terminated prepolymer (A1) and the second isocyanate group-terminated prepolymer (A2) is preferably 20 to 120 ° C, more preferably. Is 40-100 ° C.
In the urethanization reaction, known urethanation catalysts such as organic metal compounds such as dibutyltin dilaurate and dioctyltin dilaurate, organic amines such as triethylenediamine and triethylamine, and salts thereof can be used as necessary.
In addition, it does not restrict | limit especially about the preparation time of an arbitrary component (additive).

  After the completion of the reaction, the system contains a polymeric MDI that was not involved in the reaction together with the first isocyanate group-terminated prepolymer (A1) and the second isocyanate group-terminated prepolymer (A2). Becomes the component [polymeric MDI (A0)] constituting the polyisocyanate composition of the present invention as it is.

<Method for producing rigid polyurethane foam>
The production method of the present invention is a method for producing a rigid polyurethane foam in which a polyisocyanate mixture (A) and a polyol (B) are reacted in the presence of a foaming agent (C), a catalyst (D) and a foam stabilizer (E). The polyisocyanate mixture (A) contains a polymeric MDI (A0), a first isocyanate group-terminated prepolymer (A1) and a second isocyanate group-terminated prepolymer (A2), The agent (C) is characterized in that hydrofluorocarbon and / or water is used.

<Polyisocyanate mixture (A)>
The “polyisocyanate mixture (A)” used in the production method of the present invention contains polymeric MDI (A0), a first isocyanate group-terminated prepolymer (A1) and a second isocyanate group-terminated prepolymer (A2). That is, a mixture constituting an essential isocyanate compound contained in the polyisocyanate composition of the present invention.
In the “polyisocyanate mixture (A)”, other isocyanate compounds may be contained as long as the effects of the present invention are not impaired.

<Polyol (B)>
The “polyol (B)” used in the production method of the present invention is not particularly limited, and examples thereof include conventionally known polyester polyols, polyether polyols, and polycarbonate polyols.
In consideration of the strength of the rigid polyurethane foam to be formed, a low molecular polyol, a low molecular polyamine, a low molecular amino alcohol, or the like may be used in combination.

As the polyol (B) used in the production method of the present invention, it is preferable to use at least one of the following three types of polyols [polyols (b1) to (b3)], and it is preferable to use two or more types. Further preferred.
When only one of polyol (b1) and polyol (b3) is used, the formed rigid polyurethane foam may not have sufficient mechanical strength. Moreover, the polyol (B) consisting only of the polyol (b2) has an excessive viscosity and tends to be inferior in workability.

[Polyol (b1)]
One or more amine compounds such as monoethanolamine, diethanolamine, alkanolamines such as triethanolamine, tolylenediamine, ethylenediamine, diethylenetriamine, ammonia, aniline, xylylenediamine, polyamines such as diaminodiphenylmethane, etc. A polyether polyol having a hydroxyl value of 50 to 1,000 mgKOH / g, preferably 100 to 900 mgKOH / g, obtained by addition reaction of alkylene oxides such as ethylene oxide and propylene oxide using the mixture as an initiator. Furthermore, a polyhydric alcohol used for obtaining the polyol (b2) and the polyol (b3) can be used in combination as an initiator.

[Polyol (b2)]
(1) Ethylene glycol, propanediol, butanediol, diethylene glycol, dipropylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, glycerin , A mixture of one or more polyhydric alcohols such as trimethylolpropane and pentaerythritol, and adipic acid, malonic acid, fumaric acid, succinic acid, tartaric acid, oxalic acid, phthalic anhydride, isophthalic acid, terephthalic acid , 1,4-cyclohexanedicarboxylic acid and the like, and a known method using one or a mixture of two or more compounds having at least two carboxyl groups (or groups derived from carboxyl groups) According Obtained by fabricating Te, hydroxyl value 50~800mgKOH / g, polyester polyols preferably 100~700mgKOH / g. (2) A polyester polyol obtained by ring-opening polymerization of lactones (for example, ε-caprolactone).
(3) A recovered polyester obtained by decomposing a polyester polyol and a polyester molded product.

[Polyol (b3)]
Ethylene glycol, propanediol, butanediol, diethylene glycol, dipropylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, glycerin, trimethylol Obtained by addition reaction of alkylene oxides such as ethylene oxide and propylene oxide using a polyhydric alcohol having 2 to 6, preferably 2 to 5 hydroxyl groups in one molecule such as propane and pentaerythritol as an initiator. A polyether polyol having a hydroxyl value of 50 to 1,000 mg KOH / g, preferably 100 to 900 mg KOH / g.

  In each of the polyols (b1) to (b3), when the hydroxyl value is not less than a certain value (lower limit value), sufficient mechanical strength can be imparted to the formed rigid polyurethane foam. Moreover, embrittlement of the hard polyurethane foam formed can be suppressed because a hydroxyl value is below a fixed value (upper limit).

The average number of functional groups of the polyol (b1) is preferably 2 to 8, more preferably 3 to 6.
The average number of functional groups of the polyol (b2) is preferably 2 to 4, more preferably 2 to 3.
The average number of functional groups of the polyol (b3) is preferably 3 to 6, more preferably 3 to 5.

  In each of the polyols (b1) to (b3), when the average number of functional groups is a certain number (lower limit) or more, sufficient mechanical strength can be imparted to the formed rigid polyurethane foam. Moreover, embrittlement of the rigid polyurethane foam formed can be suppressed because an average functional group number is below a fixed number (upper limit).

When using a polyol (b1), it is preferable that the ratio of the polyol (b1) to a polyol (B) is 40-70 mass%.
When using a polyol (b2), it is preferable that the ratio of the polyol (b2) to a polyol (B) is 10-90 mass%.
When using a polyol (b3), it is preferable that the ratio of the polyol (b3) to a polyol (B) is 10-70 mass%.
The total proportion of polyol (b1), polyol (b2), and polyol (b3) in the polyol (B) is preferably 80% by mass or more.

When the content ratio of the polyol (b1) is excessive, the activity becomes too high, and there is a risk of causing molding defects such as voids.
When the content ratio of the polyol (b2) is excessive, the viscosity of the polyol (B) increases, and the liquid flowability and filling property of the foam tend to deteriorate.
When the content ratio of the polyol (b3) is excessive, the mechanical strength of the formed rigid polyurethane foam tends to decrease.

Suitable polyols other than polyols (b1) to (b3) constituting the polyol (B) (hereinafter abbreviated as other polyols) are preferably ethylene glycol, diethylene glycol, and polypropylene glycol having a hydroxyl value of 50 to 150 mgKOH / g. Can be mentioned.
By using at least one selected from ethylene glycol, diethylene glycol, and polypropylene glycol having a hydroxyl value of 50 to 150 mgKOH / g, the viscosity of the polyol (B) can be lowered.

  Moreover, you may use a polymer polyol as another polyol which comprises a polyol (B). This polymer polyol is based on the above-described polyether polyol or polyester polyol, and is obtained by introducing a styrene or acrylonitrile vinyl polymer or a polymer obtained from an active hydrogen group-containing compound and polyisocyanate as graft polymerization or filler. The polymer content in the polymer polyol is preferably 1 to 20% by mass.

  The viscosity (25 ° C.) of the polyol (B) is preferably 2,000 mPa · s or less, more preferably 100 to 1,800 mPa · s. When the viscosity exceeds the upper limit, workability particularly in winter is reduced.

<Foaming agent (C)>
In the production method of the present invention, hydrofluorocarbon and / or water is used as the foaming agent (C).
As addition amount of a foaming agent (C), when using hydrofluorocarbons, such as HFC-245fa, HFC-365mfc, and HFC-134a, it is 1-50 mass% with respect to a polyol (B).
Moreover, the addition amount of water in the case where hydrofluorocarbon and water are used in combination is 0.5 to 5.0% by mass with respect to the polyol (B).
Moreover, in the complete water foaming formulation which uses only water, the addition amount of water is 2.0-20.0 mass% with respect to a polyol (B).

<Catalyst (D)>
As the “catalyst (D)” used in the production method of the present invention, a known catalyst usually used for urethane foaming can be used. For example, as a urethanization catalyst, N-methylimidazole, trimethylaminoethylpiperazine, tripropylamine, tetramethylhexamethylenediamine, triethylenediamine, triethylamine, N-methylmorpholine, dimethylcyclohexylamine, dibutyltin diacetate, dibutyltin dilaurate, etc. And metal complex compounds such as acetylacetone metal salts. Trimerization catalysts include 2,4,6-tris (dimethylaminomethyl) phenol, triazines such as 1,3,5-tris (dimethylaminopropyl) hexahydro-s-triazine, 2,4-bis (dimethylamino) Methyl) phenol, amine compounds such as potassium 2-ethylhexanoate, sodium 2-ethylhexanoate, potassium acetate, sodium acetate, 2-ethylaziridine and the like, and quaternary compounds such as tertiary amine carboxylates Examples include ammonium compounds, lead compounds such as diazabicycloundecene, lead naphthenate and lead octylate, alcoholate compounds such as sodium methoxide, phenolate compounds such as potassium phenoxide, and the like. These catalysts can be used alone or in combination of two or more.
The amount of the catalyst (D) used is suitably an amount of 0.01 to 15% by mass with respect to the polyol (B).
Furthermore, for example, carbonate compounds such as ethylene carbonate and propylene carbonate can be used as a cocatalyst for promoting the reaction.

  Examples of the foam stabilizer (E) used in the production method of the present invention include known silicone surfactants such as L-5340, L-5420, L-5421, L-5740, L, manufactured by Nippon Unicar. -580, SZ-1142, SZ-1642, SZ-1605, SZ-1649, SH-190, SH-192, SH-193, SF-2945F, SF-2940F, SF-2936F, manufactured by Toray Dow Corning Silicone, SF-2938F, SRX-294A, Shin-Etsu Chemical F-305, F-341, F-343, F-374, F-345, F-348, Goldschmitt B-8404, B-8407, B -8465, B-8444, B-8467, B-8433, B-8466, B-8870, B-8450, B-8460, etc. It is. The amount of (E) used is suitably 0.1 to 5% by weight based on the polyol (B).

  In the production method of the present invention, an additive can be used (the polyisocyanate mixture (A) and the polyol (B) are reacted in the presence of the additive). Examples of the additives include plasticizers, fillers, colorants, flame retardants, organic or inorganic fillers, antioxidants, ultraviolet absorbers, plasticizers, pigments / dyes, antibacterial agents / antifungal agents, and the like. . In the present invention, it is preferable to use a flame retardant. Examples of the flame retardant include phosphate esters such as triethyl phosphate and tris (β-chloropropyl) phosphate, and phosphate compounds such as phosphite esters such as ethyl phosphite and diethyl phosphite.

Specific steps of the production method of the present invention are as follows.
(1) A polyisocyanate composition containing a polymeric MDI (A0), a first isocyanate group-terminated prepolymer (A1), a second isocyanate group-terminated prepolymer (A2), and a silicone foam stabilizer (A3) “Liquid A” and the polyol (B) as “Liquid B”.

(2) Each of foaming agent (C), catalyst (D), foam stabilizer (E) and additive (optional component) is mixed in liquid A and / or liquid B. In addition, it is preferable to mix a foaming agent (C), a catalyst (D), and a foam stabilizer (E) in B liquid. Moreover, the silicone type foam stabilizer (A3) contained in A liquid from the beginning is handled as what comprises a foam stabilizer (E) in a subsequent process.

(3) A polyisocyanate mixture (A) comprising a mixture of liquid A and liquid B and containing polymeric MDI (A0), first isocyanate group-terminated prepolymer (A1) and second isocyanate group-terminated prepolymer (A2) And polyol (B) are reacted in the presence of a foaming agent (C), a catalyst (D) and a foam stabilizer (E) to foam and cure the reaction system.

  There is no particular limitation on the mixing apparatus for the liquid A and liquid B. For example, a small mixer, a low-pressure or high-pressure foaming machine for injection foaming, and a slab foaming used for producing general urethane foam. Low pressure or high pressure foaming machines, low pressure or high pressure foaming machines for continuous lines, spray foaming machines for spraying work, etc. can be used. In addition, it is preferable to adjust the temperature of the A liquid and B liquid mixed to 30-60 degreeC.

  The rigid polyurethane foam obtained by the production method of the present invention has a chemical bond such as a urethane bond or a urea bond (so-called urethane foam). Depending on the production conditions, an isocyanurate group can be generated at the time of foaming, and the isocyanurate-modified polyurethane foam (so-called isocyanurate foam) thus obtained is also included in the “rigid polyurethane foam”. The isocyanurate group is generated by trimerizing an isocyanate group with a trimerization catalyst, and can improve mechanical strength, heat resistance, and the like.

  In the production method of the present invention, the preferred isocyanate index [(number of moles of all isocyanate groups in polyisocyanate mixture (A) / number of moles of all active hydrogen groups in polyol (B)) × 100] is the so-called urethane foam. In some cases, it is preferably 50 to 140, more preferably 70 to 130. Moreover, in the case of what is called isocyanurate foam formed using a trimerization catalyst, it is preferable that it is 140-800, More preferably, it is 150-500. When the isocyanate index is less than 50 in the case of urethane foam and less than 140 in the case of isocyanurate foam, the obtained foam may not have sufficient strength and tends to shrink. On the other hand, if it exceeds 140 in the case of urethane foam and exceeds 800 in the case of isocyanurate foam, the brittleness of the resulting foam tends to increase and the adhesiveness tends to decrease.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In the following, “%” and “part” indicate “% by mass” and “part by mass”, respectively.

<Preparation Example 1>
According to the formulation shown in Table 1 below, 97.0 parts of polymeric MDI (1), 0.5 part of specific polyester polyol (a1-1), 0.5 part of polyether monool (a2-1), silicone-based foam stabilizer Using 0.5 parts of the agent (A3-1) and 1.5 parts of the liquid ester compound (A4-1), the polyisocyanate composition (NCO-1) of the present invention was prepared as follows. This polyisocyanate composition (NCO-1) had an isocyanate content of 30.0% and a viscosity (25 ° C.) of 180 mPa · s.

[Preparation method]
A reactor equipped with a stirrer, a cooling tube, a nitrogen introduction tube, and a thermometer: Polymer MDI (1) was charged into a reactor of 100 kg and heated to 60 ° C. while stirring. Next, the specific polyester polyol (a1-1), polyether monool (a2-1), silicone-based foam stabilizer (A3-1), and liquid ester-based compound (A4-1) are respectively charged into the reactor. Went. After completion of the preparation, the mixture was reacted at 60 ° C. for 2 hours with stirring to prepare a polyisocyanate composition (NCO-1) of the present invention.

<Preparation Examples 2-8>
In accordance with the formulation shown in Table 1 below, polymeric MDI (1) to (4), specific polyester polyols (a1-1) to (a1-3), polyether monools (a2-1) to (a2-2), The polyisocyanate composition (NCO-2) to (NCO) of the present invention was prepared in the same manner as in Preparation Example 1 except that each of the silicone foam stabilizer (A3-1) and the liquid ester compound (A4-1) was used. -8) was prepared.
The isocyanate content and viscosity (25 ° C.) of the resulting polyisocyanate composition are also shown in Table 1.

<Comparative Preparation Example 1>
Polymeric MDI (1) was prepared according to the formulation shown in Table 2 below. This is designated as “polyisocyanate (NCO-C1)”. This polyisocyanate (NCO-C1) had an isocyanate content of 31.0% and a viscosity (25 ° C.) of 180 mPa · s.

<Comparative Preparation Example 2>
Polymeric MDI (2) was prepared according to the formulation shown in Table 2 below. This is designated as “polyisocyanate (NCO-C2)”. This polyisocyanate (NCO-C1) had an isocyanate content of 31.0% and a viscosity (25 ° C.) of 180 mPa · s.

<Comparative Preparation Example 3>
A polyisocyanate composition for comparison in the same manner as in Preparation Example 1 except that a polyether monool (a2-2) was used instead of the specific polyester polyol (a1-1) according to the formulation shown in Table 2 below. (NCO-C3) was prepared. This polyisocyanate composition (NCO-C3) had an isocyanate content of 30.0% and a viscosity (25 ° C.) of 185 mPa · s.

<Preparation Example 9>
In accordance with the formulation shown in Table 2 below, 88.0 parts of polymeric MDI (1), 5.0 parts of specific polyester polyol (a1-1), 5.0 parts of polyether monool (a2-1), silicone-based foam stabilizer Polyisocyanate composition (NCO) of the present invention (for reference) in the same manner as in Preparation Example 1 except that 0.5 part of the agent (A3-1) and 1.5 part of the liquid ester compound (A4-1) were used. -9) was prepared. This polyisocyanate composition (NCO-9) had an isocyanate content of 26.6% and a viscosity (25 ° C.) of 320 mPa · s.

<Preparation Example 10>
In accordance with the formulation shown in Table 2 below, 99.9 parts of polymeric MDI (1), 0.01 part of specific polyester polyol (a1-1), 0.01 part of polyether monool (a2-1), silicone-based foam stabilizer Polyisocyanate composition (NCO) of the present invention (for reference) in the same manner as in Preparation Example 1 except that 0.01 part of the agent (A3-1) and 0.07 part of the liquid ester compound (A4-1) were used. -10) was prepared. This polyisocyanate composition (NCO-10) had an isocyanate content of 31.0% and a viscosity (25 ° C.) of 180 mPa · s.

<Uniform mixing with hydrofluorocarbons and water>
The polyisocyanate compositions (NCO-1) to (NCO-8) of the present invention obtained by the above Preparation Examples 1 to 8, and the polyisocyanate (NCO-C1) to (NCO--) prepared in Comparative Preparation Examples 1 and 2 C2), a comparative polyisocyanate composition (NCO-C3) obtained in Comparative Preparation Example 3, and a polyisocyanate composition (NCO-9) of the present invention (for reference) obtained in Preparation Examples 9-10 About each of thru | or (NCO-10), the uniform mixing property with hydrofluorocarbons and water was evaluated in accordance with the following method. The results are shown in Tables 1 and 2 below.

(Evaluation method for uniform mixing with hydrofluorocarbons)
A polyisocyanate (composition) 50 g and hydrofluorocarbon (HFC-365mfc) 20 g were charged into a laboratory mixer, mixed at 7,000 rpm for 3 seconds, and the appearance of the mixture was visually observed immediately after the operation and after 30 minutes. Observed and evaluated based on the following criteria.

(Evaluation method for uniform mixing with water)
A polyisocyanate (composition) 50 g and purified water 5 g were charged into a lab mixer, mixed at 7,000 rpm for 3 seconds, and the appearance of the mixture was observed visually and immediately after 30 minutes. Based on the evaluation.

(Evaluation criteria)
“◎”: A homogeneous emulsified state was obtained, and this state was maintained even after 30 minutes.
“◯”: An emulsified state was obtained, but phase separation occurred after 30 minutes.
“×”: Phase separation occurred immediately after the operation.

  In Tables 1 and 2 above, details of the compounds (components or reaction raw materials) indicated by reference numerals are as follows. The unit of these usage amounts is “parts”.

[1] Polymeric MDI (1):
(I) MPC peak area ratio by GPC = 40%
(Ii) 4,4′-MDI ratio in MDI = 99% (measured by GC)
(Iii) Isocyanate content = 31.0%
(Iv) Average number of functional groups = 2.3
(V) Acidity = 0.01%

[2] Polymeric MDI (2):
(I) MPC peak area ratio by GPC = 37%
(Ii) 4,4′-MDI ratio in MDI = 83% (measured by GC)
(Iii) Isocyanate content = 31.0%
(Iv) Average number of functional groups = 2.3
(V) Acidity = 0.01%

[3] Polymeric MDI (3):
(I) MDI (binuclear body)
(Ii) 4,4′-MDI ratio = 99% (measured by GC)
(Iii) Acidity = 0.001%

[4] Polymeric MDI (4):
(I) MDI (binuclear body)
(Ii) 4,4′-MDI ratio = 72% (measured by GC)
(Iii) Acidity = 0.001%

[5] Specific polyester polyols (a1-1) to (a1-3):
(I) Sulfonato group (sodium sulfonate residue) -containing adipate obtained by reacting dimethyl 5-sodium sulfoisophthalate, adipic acid and 1,6-hexanediol according to a conventional method (ester reaction and transesterification reaction) Polyester polyol. (Ii) (a1-1):
Number average molecular weight = 1,000, content ratio of sulfonate group = 0.4 mmol / g
(Iii) (a1-2):
Number average molecular weight = 2,000, content ratio of sulfonate group = 0.4 mmol / g
(Iv) (a1-3):
Number average molecular weight = 1,000, content ratio of sulfonate group = 0.2 mmol / g

[6] Polyether monool (a2-1):
(I) Initiator = 2-ethylhexanol (ii) Number average molecular weight = 800
(Iii) PO (oxypropylene) / EO (oxyethylene) = 100/0 (mass ratio)

[7] Polyether monool (a2-2):
(I) Initiator = methanol (ii) Number average molecular weight = 700
(Iii) PO / EO = 0/100 (mass ratio)

[8] Silicone foam stabilizer (A3-1):
Polysiloxane-polyether copolymer “B-8460” (manufactured by Goldschmidt) [9] Liquid ester compound (A4-1):
Propylene carbonate

<Preparation Examples 11-18>
Polyol compositions (OH-1) to (OH-8) were prepared by mixing the components according to the formulation shown in Table 3 below.

  In Table 3 above, details of the compounds (components) indicated by reference numerals are as follows. The unit of these usage amounts is “parts”.

[1] Polyol (B-1):
Polyester polyol “terol 250” having a hydroxyl value of 250 using phthalic anhydride / diethylene glycol as a raw material (manufactured by OXID, USA)
[2] Polyol (B-2):
Polyester polyol “terol 280” having a hydroxyl value of 110 using phthalic anhydride / diethylene glycol as a raw material (manufactured by OXID, USA)
[3] Polyol (B-3):
Mannich polyether polyol “DK polyol 3773” having a hydroxyl value of 450 (Daiichi Kogyo Seiyaku Co., Ltd.)
[4] Polyol (B-4):
Mannich polyether polyol “DK polyol 3776” having a hydroxyl value of 350 [5] Foaming agent (C-1): HFC-245fa (manufactured by Central Glass Co., Ltd.)
[6] Foaming agent (C-2): HFC-365mfc (manufactured by Solvay)
[7] Foaming agent (C-3): Purified water [8] Catalyst (D-1): Trimerization catalyst “DABCO K15” (manufactured by Air Products)
[9] Catalyst (D-2): Trimerization catalyst “DABCO P15” (manufactured by Air Products)
[10] Catalyst (D-3): Lead octylate [11] Foam stabilizer (E-1):
Polysiloxane-polyether copolymer “B-8460” (manufactured by Goldschmidt)
[12] Flame retardant (F-1): Tris (β-chloropropyl) phosphate “Philol PCF” (manufactured by Akzo Nobel)
[13] Specific polyester polyol (a1-1):
The same as described in Table 1 and Table 2.

<Examples 1 to 14>
In accordance with the combinations shown in Table 4 below, a mixed liquid (mixed mass ratio = 100: 100) of the polyisocyanate composition (liquid A) and the polyol composition (liquid B) was bonded to an adherend (50 mm × 50 mm). ) Is applied to a veneer plate (1000 mm × 1000 mm) to which a polyisocyanate mixture (A) and a polyol (B) are converted into a foaming agent (C), a catalyst (D) and a foam stabilizer (E ) To form a rigid polyurethane foam on the entire surface of the veneer plate (1000 mm × 1000 mm) to which the adherend was attached.
Here, the blowing and foaming conditions are as follows.
-Foaming machine: Gasmer spraying foaming machine "FF-1600 type"
・ Temperature of adherend: 5 ℃
・ Primary heater temperature: 45 ℃
-Foam thickness: 30-40mm

<Comparative Examples 1-5, Reference Examples 1-2>
In accordance with the combinations shown in Table 4 below, a mixed liquid (mixed mass ratio = 100: 100) of the polyisocyanate composition (liquid A) and the polyol composition (liquid B) was bonded to an adherend (50 mm × 50 mm). ) Was applied to the veneer plate (1000 mm × 1000 mm) to which the adherend was attached, thereby forming a rigid polyurethane foam on the entire surface of the veneer plate (1000 mm × 1000 mm) to which the adherend was attached.
Here, the foaming conditions and the like were the same as in Example 1.

<Adhesiveness to adherend>
Each of the rigid polyurethane foams formed on the adherend (50 mm × 50 mm plywood) according to Examples 1 to 14, Comparative Examples 1 to 5, and Reference Examples 1 to 2 was placed in a temperature environment of 5 ° C. for 2 hours. After leaving still, the peeling test was done and the adhesive strength with respect to the said adherend (plywood) was measured. The results are also shown in Table 4.

<Foam shrinkage at normal temperature (rate of volume change due to standing)>
From each of the rigid polyurethane foams formed on the plywood board (1000 mm × 1000 mm) according to Examples 1 to 14, Comparative Examples 1 to 5 and Reference Examples 1 to 2, the length = 100 mm, the width = 100 mm, and the height (foaming direction) ) = 25 mm sample was taken, and this sample was allowed to stand for 24 hours under a temperature condition of 25 ° C., and then the volume change rate of the foam was measured by measuring the vertical, horizontal, and height dimensions again. Based on the criteria of the evaluation. The results are also shown in Table 4.

(Evaluation criteria)
“◎”: Volume change rate = 2% or less “◯”: Volume change rate = 2% or more and less than 5% “×”: Volume change rate = 5% or more

<Examples 15 to 28, Comparative Examples 6 to 10, Reference Examples 3 to 4>
According to the combinations shown in Table 5 below, a mixed liquid (mixed mass ratio = 100: 100) of the polyisocyanate composition (liquid A) and the polyol composition (liquid B) was prepared from a coated hot-dip galvanized steel sheet based on JIS G3312. The veneer plate (1000 mm × 1000 mm) to which the adherend (galvanized steel plate) is affixed by spraying the veneer plate (1000 mm × 1000 mm) to which the adherend (50 mm × 50 mm × 0.27 mm) is attached A rigid polyurethane foam was formed on the entire surface. Here, the blowing and foaming conditions were the same as in Example 1. For each of the rigid polyurethane foams formed on the adherend (galvanized steel sheet), the adherend is produced in the same manner as in each of Examples 1 to 14, Comparative Examples 1 to 5, and Reference Examples 1 and 2. The adhesion strength to (galvanized steel sheet) was measured. The results are also shown in Table 5 below.

<Examples 29-42, Comparative Examples 11-15, Reference Examples 5-6>
According to the combinations shown in Table 6 below, a mixed liquid (mixing mass ratio = 100: 100) of the polyisocyanate composition (liquid A) and the polyol composition (liquid B) was bonded to an adherend (50 mm). A rigid polyurethane foam was formed on the entire surface of the veneer plate (1000 mm × 1000 mm) to which the adherend (aluminum liner paper) was attached by spraying the veneer plate (1000 mm × 1000 mm) to which the × 50 mm) was attached. Here, the blowing and foaming conditions were the same as in Example 1. For each of the rigid polyurethane foams formed on the adherend (aluminum liner paper), the adherends were prepared in the same manner as in Examples 1 to 14, Comparative Examples 1 to 5, and Reference Examples 1 and 2. The adhesion strength to (aluminum liner paper) was measured. The results are also shown in Table 6 below.

The polyisocyanate composition of the present invention is used for various heat insulating materials such as boards, panels, refrigerators, baskets, doors, shutters, sashes, concrete houses, bathtubs, cryogenic tank equipment, refrigerated warehouses, pipe covers, anti-condensation, slabs, etc. Applicable.
The polyisocyanate composition of the present invention is particularly suitable for use in spraying (spray foaming) on various adherends.

Claims (2)

A polyisocyanate composition used for producing a rigid polyurethane foam formed on an adherend by a spray method by a foaming formulation using hydrofluorocarbons and water as a foaming agent ,
(A0) Polymeric MDI in which the proportion of MDI is 20.0-80.0% ,
(A1) The first isocyanate group terminal obtained by reacting a polyester polyol (a1) having a sulfo group or a sulfonate group in the molecular structure with a polymeric MDI having a MDI ratio of 20.0 to 80.0% Prepolymer,
(A2) a second isocyanate group-terminated prepolymer obtained by reacting a polyether monool (a2) with a polymeric MDI having a MDI content of 20.0 to 80.0% ,
(A3) a silicone-based foam stabilizer , and
(A4) a liquid ester compound that is liquid at room temperature ,
The polyisocyanate composition, wherein the ratio of the first isocyanate group-terminated prepolymer (A1) to the total amount of the isocyanate compound is 0.05 to 5.0 mass% . A method for producing a rigid polyurethane foam formed on an adherend by a spray method using the polyisocyanate composition according to claim 1,
A polyisocyanate mixture (A) containing the polymeric MDI (A0), the first isocyanate group-terminated prepolymer (A1) and the second isocyanate group-terminated prepolymer (A2), and a polyol (B),
Hydrofluorocarbon and water as the foaming agent (C), catalyst (D) , foam stabilizer (E) , and the silicone foam stabilizer (A3) and the liquid ester compound which are components of the polyisocyanate composition The manufacturing method of the rigid polyurethane foam made to react in presence of (A4) .