WO2008035458A1

WO2008035458A1 - Process for producing rigid polyurethane slab foam, rigid polyurethane slab foam, and heat-insulating material for piping

Info

Publication number: WO2008035458A1
Application number: PCT/JP2007/000998
Authority: WO
Inventors: Hideki Inohara
Original assignee: Nippon Polyurethane Industry Co., Ltd.
Priority date: 2006-09-19
Filing date: 2007-09-13
Publication date: 2008-03-27
Also published as: CN101516946A; JP2008074880A; CN101516946B

Abstract

[PROBLEMS] To provide a process for producing a rigid polyurethane slab foam which does not scorch inside, has a low thermal conductivity, retains excellent flame retardancy over long, and has excellent dimensional stability. [MEANS FOR SOLVING PROBLEMS] A foam-forming composition comprising [A] a modified polyisocyanate which is obtained by modifying at least part of a polymeric MDI having an MDI content of 30-80 mass% with a modifier comprising a polyester polyol having a hydroxy value of 150-300 mg-KOH/g and which has an NCO content of 24.0-28.0%, [B] a polyol ingredient comprising at least 50 mass% at least one member selected among (B1) a polyether polyol made with toluenediamine as an initiator, (B2) a polyether polyol made with sorbitol as an initiator, and (B3) a polyether polyol made with sucrose as an initiator, and [C] a blowing agent comprising water is reacted to cause it to freely foam, with the top kept open.

Description

Specification

Manufacturing method of rigid polyurethane slab foam, rigid polyurethane slab foam, and heat insulating material for piping

Technical field

[0001] The present invention relates to a method for producing a rigid polyurethane slab foam, a rigid polyurethane slab foam, and a heat insulating material for piping. More specifically, the invention does not generate a scoring inside, has low thermal conductivity, and is flame retardant. The present invention relates to a method for producing an excellent rigid polyurethane slab foam, a rigid polyurethane slab foam produced by this method, and a heat insulating material for piping obtained by cutting the rigid polyurethane slab foam.

[0002] The rigid polyurethane slab foam according to the present invention is not foamed into a specific shape such as various panels, pods, and refrigerators, and is foamed by spray application like in-situ foaming. It is produced by free-foaming the composition injected into the mold with the top surface open, or by free-foaming the composition continuously discharged into the continuous line with the top surface open. It is a hard “slab foam”.

Background art

Conventionally, chlorofluorocarbons and hydrofluorocarbons have been used as foaming agents for forming rigid polyurethane foams. However, due to the recent demand for de-fluorocarbons, water-based foamed rigid polyurethane foam that uses water as a foaming agent has attracted attention.

[0004] A composition for forming a rigid polyurethane foam by a water foaming formulation contains a polyisocyanate, a polyol component, and water as a foaming agent. Here, as the “polyisocyanate”, polymethylene polyphenylpolysocyanate containing diphenylmethane diisocyanate is usually used. In addition, as a part of the “polyol component”, a polyether formed by adding ethylene oxide or propylene oxide to toluenediamine. Terpolyol is used (for example, see Patent Documents 1 to 5).

[0005] However, when a rigid polyurethane slab foam is produced by a conventionally known water foaming composition including the compositions disclosed in Patent Documents 1 to 5, the slab foam is formed inside the formed slab foam. There is a problem that (burn) occurs. This is because in the formation of slab foam of water foaming formula, the amount of heat generated is large, and it is difficult to dissipate internal heat due to the thick shape (slab) (the amount of internal heat storage is large) It depends on things. The scorch generated inside the slab foam leads to poor appearance and poor strength of the final product obtained by cutting the slab foam. Thus, the internal scorch, which is not particularly problematic in thin mold forms, is a serious problem in the production of slab foam, and its solution is strongly desired.

[0006] Further, none of the rigid polyurethane foams produced by the compositions disclosed in Patent Documents 1 to 5 have high heat conductivity and sufficient heat insulation effect ■ heat insulation effect. Furthermore, flame retardancy and dimensional stability are not satisfactory.

Patent Document 1: Japanese Patent Application Laid-Open No. 5-186059

Patent Document 2: Japanese Patent Laid-Open No. 6-2 2 8 2 60

Patent Document 3: Japanese Patent Laid-Open No. 6-2 3 9 9 5 6

Patent Document 4: Japanese Patent Laid-Open No. 7_1 0 9 5 5

Patent Document 5: Japanese Patent Laid-Open No. 9-1 3 2 6 3 1

Disclosure of the invention

Problems to be solved by the invention

[0007] The present invention has been made based on the above situation. The first object of the present invention is to produce a rigid polyurethane slab foam that does not generate scorch inside, has low thermal conductivity, maintains excellent flame retardance over time, and has excellent dimensional stability. It is to provide a method. The second object of the present invention is to make a rigid polyurethane slab that does not generate a scorch inside, has low thermal conductivity, can maintain excellent flame retardance over time, and has excellent dimensional stability. Provide a form There is. A third object of the present invention is a heat insulating material obtained by cutting a rigid polyurethane slab foam, which has no appearance defect or strength defect due to scorch, has a low thermal conductivity, and has a sufficient heat insulating effect. An object of the present invention is to provide a heat insulating material for piping which has a heat retaining effect, can maintain excellent flame retardance with time, and has excellent dimensional stability.

Means for solving the problem

[0008] The production method of the present invention comprises a polymethylene polyphenyl polyisocyanate containing [A] diphenylmethane diisocyanate (hereinafter abbreviated as “MDI”) in a proportion of 30 to 80% by mass. Nate (hereinafter also referred to as “polymeric MD I (a)”) is composed of a modifying agent comprising a polyester polyol having a hydroxyl value of 150 to 30 Omg KO H / g (hereinafter referred to as “specific modification”). And a modified polyisocyanate having an NCO content of 24.0 to 28.0% obtained by modification in (1); and [B] a polyether polyol (in which toluenediamine is used as an initiator). B 1), a polyether polyol (B2) having sorbitol as an initiator, and a polyether polyol (B 3) having sucrose as an initiator in a proportion of 50% by mass or more in total A foam-forming composition containing an all component and [C] a foaming agent made of water is reacted to cause free foaming in a state where the top surface is open.

In the production method of the present invention, the following modes are preferred. (1) The hydroxyl value of the specific modifying agent used to obtain the [A] component is 200 to 300 mg KO H / g, and the NCO content of the [A] component is 24.5 to 27.5. Must be%. (2) The specific modifier is at least one polyhydric alcohol selected from ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and 3-methyl-1,5-pentanediol. And a polyester polyol obtained from at least one polybasic acid selected from orthophthalic acid, isophthalic acid, terephthalic acid and adipic acid. (3) The specific modifier is diethylene glycol It must be a polyester polyol obtained from coal and orthophthalic acid and / or adipic acid. (4) The component [A] is obtained by modifying a part (a 1) of the polymeric MDI (a) with a specific denaturing agent and then mixing it with the remainder (a 2) of the polymer MD I (a). To be obtained. (5) A part (a 1) of the polymeric MD I (a) subjected to the denaturation treatment is MD I (binuclear). (6) The component [B] is a polyether polyol.

(B 1), polyether polyol (B 2), and polyether polyol

(B 3). (7) Polyether polyol (B 1) can be obtained by adding ethylene oxide and / or propylene oxide to toluenediamine, in particular, ethylene oxide and propylene oxide added to toluenediamine. And the mass ratio ([EO]: [PO]) is 0 to 50: 100 to 50. (8) Polyetherpolyol (B 2) is obtained by adding ethylene oxide and / or propylene oxide to sorbitol, and in particular, ethylene oxide and propylene oxide added to toluenediamine. The mass ratio ([EO]: [PO]) to the door is 0 to 50: 100 to 50. (9) Polyether polyol

(B 3) is obtained by adding ethylene oxide and / or propylene oxide to sucrose, and in particular, the mass ratio of ethylene oxide to propylene oxide added to toluenediamine ( [EO]:

[PO]) is 0 to 50: 100 to 50.

[0010] The rigid polyurethane slab foam of the present invention is obtained by the production method of the present invention. The rigid polyurethane slab foam of the present invention is preferably formed by free-foaming the foam-forming composition in a mold having an open top surface having a bottom area of 0.25 m ² or more. Further, the rigid polyurethane slab foam of the present invention is preferably formed by freely foaming the foam-forming composition continuously discharged at a width of 0.5 m or more on a continuous line in a state where the top surface is open. .

[0011] The heat insulating material for piping of the present invention cuts the rigid polyurethane slab foam of the present invention. It is obtained by processing.

The invention's effect

[0012] According to the production method of the present invention, a rigid polyurethane that does not generate scorch inside the slab, has low thermal conductivity, maintains excellent flame retardancy over time, and has excellent dimensional stability.

Slab foam can be manufactured. The rigid polyurethane slab foam of the present invention does not generate scorch inside, has low thermal conductivity, can maintain excellent flame retardance over time, and has excellent dimensional stability. The heat insulating material for piping according to the present invention has no poor appearance or poor strength due to scorch, has a low heat conductivity, has a sufficient heat insulating effect, and has a heat retaining effect, and maintains excellent flame retardance over time. It can be held and has excellent dimensional stability.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. <Production Method of the Present Invention> The production method of the present invention is selected from the component [A] comprising a modified polyisocyanate; and polyether polyol (B 1), polyether polyol (B 2) and polyether polyol (B 3). A foam-forming composition containing a polyol component containing at least one of the above components in a total proportion of 50% by mass or more and a water (foaming agent) [C] component is reacted, and the top surface is open. It is characterized by free foaming.

[0014] <[A] component> [A] component is polymeric MD containing MD I (binuclear body)

It is a modified polyisocyanate obtained by modifying at least a part of I (a) with a specific modifying agent. The MD I (binuclear) that constitutes the polymeric MD I (a) includes isomers of 4, 4 '— MD I, 2, 4' — MD I, 2, 2 '— MD I, and MD The ratio of 4, 4 ′ —MD I to I is preferably 50% or more.

[0015] The ratio of MD I (binuclear body) to polymeric MD I (a) is 30 ~

80% by mass, and preferably 35 to 75% by mass.

[0016] When the ratio of MD I (binuclear) is less than 30% by mass, the polymer The viscosity of the modified polyisocyanate obtained by MD I becomes excessive and adversely affects the miscibility with the [B] component. On the other hand, when the ratio of MD I (binuclear) exceeds 80% by mass, the composition containing the modified polyisocyanate obtained by the polymeric MD I is insufficient in strength and the foam does not start up normally. The desired rigid polyurethane slab foam may not be formed. In addition, the rigid polyurethane slab foam formed by the composition exhibits brittleness and does not have sufficient strength. In addition, the storage stability of polymeric MDI (a), particularly the storage stability of liquids in a low-temperature atmosphere at 0 ° C or below, deteriorates (eg, precipitation of crystals).

[0017] The component [A] is obtained by modifying at least part of the polymeric MD I (a) with a specific modifying agent. A specific modifier for modifying polymeric MD I is a polyester polyol having a hydroxyl value of 150 to 300 mg KOH / g.

[0018] The polyester polyol constituting the specific modifier can be obtained by esterifying a polyhydric alcohol and a polybasic acid according to a conventional method.

Here, as the polyhydric alcohol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol and 3_methyl_1,5_pentanediol are preferable, and ethylene glycol is particularly preferable. .

[0020] As the polybasic acid, orthophthalic acid, isophthalic acid, terephthalic acid and adipic acid are preferable, and orthophthalic acid and adipic acid are particularly preferable.

[0021] Examples of suitable polyester polyols that constitute the specific modifier include polyester polyols obtained from polyethylene glycol and orthophthalic acid and / or adipic acid. By using such a polyester polyol as a specific modifier, the resulting modified polyisocyanate has a good appearance (no turbidity of the liquid) and is obtained. It is excellent in combustion performance after aging and dimensional stability in rigid polyurethane slab foam.

[0022] The hydroxyl value of the polyester polyol constituting the specific modifier is 150 to 30 Omg KOH / g, preferably 200 to 30 Omg KOH / g, and more preferably 230 to 270 mg KOH / g. When a polyester polyol having a hydroxyl value of less than 150 mg KOH / g is used as a modifier for polymeric MD I, the strength of the rigid polyurethane slab foam formed by the resulting composition is reduced. Therefore, it is not preferable because the dimensional stability is lowered (see Comparative Examples 1 and 2 described later). On the other hand, when a polyester polyol having a hydroxyl value of more than 300 mg KOH / g is used as a modifier for polymeric MDI, turbidity occurs in the resulting modified polyisocyanate (Preparation Examples 13 and 1 described later). 4), such a modified polyisocyanate is not preferred because of poor storage stability, such as phase separation of the liquid over time (becomes a non-uniform liquid).

[0023] The number of functional groups of the polyester polyol constituting the specific modifier is preferably 2 to 4, particularly preferably 2. When a monofunctional polyester (monool) is used as a modifier for polymeric MD I (a), the compressive strength and dimensional stability of the rigid polyurethane slab foam formed from the resulting composition Decreases. On the other hand, when a polyester polyol having 5 or more functional groups is used as a modifier for polymeric MD I (a), the resulting modified isocyanate has an excessively high viscosity, for example, causing poor mixing. A malfunction occurs.

[0024] The number average molecular weight of the polyester polyol constituting the specific modifier is preferably 370 to 750, more preferably 370 to 550.

[0025] As a modification method using a specific denaturing agent, pre-warmed polymeric MD I

Examples of the method (a) include adding a specific modifier and stirring and mixing the system. The heating temperature during stirring is, for example, 50 to 100 ° C The temperature is preferably 60 to 80 ° C.

[0026] As a method of preparing the component [A] by modifying a part of the polymeric MD I (a), for example, (i) Polymeric MD I (a) and a part (a 1), The remainder (a 2) is divided into (mouth) “Part of Polymeric MDI (a 1)” by modifying with a specific denaturing agent, “Modified (Polymeric) MD I (A 1)” And (c) “modified (polymeric) MD I (A 1)” and “unmodified“ residue of polymeric MD I (a 2) ”can be mixed. By preparing the [A] component by such a method, an increase in the viscosity of the obtained [A] component can be suppressed.

[0027] Here, the "polymeric MD I part (a 1)" to be denatured and the "polymeric MD I remaining part (a 2)" to be added later do not have to have the same composition. For example, each nucleus distribution may be different. Alternatively, two types of polymeric MDIs with different nuclear distributions may be prepared, and one of them may be the (a 1) component and the other may be the (a 2) component. Here, from the standpoint of excellent viscosity-inhibiting effect in the obtained [A] component, the modified “part of polymeric MD I (a 1)” is only MD I (binuclear). Preferably it consists of.

[0028] In this case, (i) Polymeric MD I (a) is part of MD I

(a 1) and the remainder (a 2) consisting of polymeric MDI (or preparing (a 1) component consisting of MDI and (a 2) component consisting of polymeric MDI) , (Mouth) “Part of MD I (a 1)” is modified with a specific denaturing agent to obtain “modified MD I (A 1)”, and (c) “modified MD [A] component can be obtained by mixing “I (A 1)” and “residue (a 2) of polymeric MD I”. In this case, MD I (binuclear body) may be included in the “residue (a 2) of polymeric MDI”.

[0029] It should be noted that as described above, it is not divided, and “all” in Polymeric MD I (a) is attached. Modification treatment may be performed. Even if the polymer MD I (a) is modified “all”, the “modified polyisocyanate” constituting the component [A] is not modified with the unmodified polymer MD I molecule. Polymeric MD I molecules coexist. That is, the polyester polyol molecules constituting the specific modifier are not prepolymerized by bonding to all of the molecules constituting the polymeric MD I (a).

[0030] For example, in the “modified polyisocyanate” modified with a polyester polyol represented by the formula: HO_R ¹ _OH (wherein R ¹ is a group containing a polyester structure), the formula: R ² (NCO ) _m (wherein R ² is a polymethylene polyphenyl structural unit and m is an integer greater than or equal to 2.) “Unmodified polymeric MD I molecule” represented by the formula: (OCIS m ^ Rz— N HCOO— R ¹ — 0— CON H— R ² (NCO) “Modified polymeric MD I molecule” exists.

[0031] The NCO content of the modified polyisocyanate constituting the component (A) is usually 24.

It is 0 to 28.0%, preferably 24.5 to 27.5%. As a result, the calorific value is reduced, the reaction during foam formation is mild, and the occurrence of scorch inside can be reliably prevented even for thick slab foam. The NCO content of the modified polyisocyanate can be controlled by adjusting the amount of specific denaturant used (ratio of use relative to polymeric MD I (a)).

[0032] The modified polyisocyanate having an NCO content of less than 24.0% cannot be circulated in the piping or the hose of the foaming machine because its viscosity is excessive. [B] In some cases, it cannot be uniformly mixed with a polyol mixture containing (see Comparative Example 7 described later).

[0033] —On the other hand, when the NCO content of the modified polyisocyanate exceeds 28.0%, in the slab foam formed by the composition obtained, it is possible to prevent the occurrence of internal scoring. Not possible (see Comparative Example 5 below).

[0034] <[B] component> [B] component constituting the foam-forming composition is toluene At least one selected from polyether polyol (B 1) using diamine as an initiator, polyether polyol (B2) using sorbitol as an initiator, and polyether polyol (B3) using sucrose as an initiator Preferably, it consists of a polyol component containing 2 types, more preferably 3 types, in such a proportion that the total of these is 50% by mass or more.

The polyether polyol (B 1) is obtained by adding toluene oxide and / or propylene oxide to toluenediamine as an initiator.

[0036] The component [B] containing the toluenediamine-based polyether polyol (B 1) in a certain ratio can reduce the size of the cell in the hard polyurethane slab foam to be formed, and has low thermal conductivity. (Insulation and heat insulation) can be achieved. In addition, excellent flame retardancy can be imparted to the formed rigid polyurethane slab foam. Furthermore, the [B] component containing the polyether polyol (B 1) is excellent in compatibility with the [A] component.

[0037] As the toluene diamine, 2,4_toluene diamine and 2,6_toluene diamine can be used alone or a mixture of both.

[0038] Here, the mass ratio of ethylene oxide to propylene oxide added to toluenediamine ([EO]: [0]) is preferably 0 to 50: 100 to 50, and more preferably. 0 to 35: 1 00 to 65. Thereby, the dimensional stability of the obtained rigid polyurethane slab foam can be improved.

[0039] The hydroxyl value of the polyether polyol (B 1) is preferably 200 to 700 mg KOH / g, more preferably 300

~ 50 Om g KO H / g. The number average molecular weight of the polyether polyol (B 1) is preferably 320 to 1,200, more preferably 450 to 750.

[0040] The polyether polyol (B2) has sorbitol (glucitol) as an initiator and ethylene oxide and / or propylene oxide. It is obtained by adding.

[0041] Here, the mass ratio of ethylene oxide to propylene oxide ([EO]: [PO]) added to sorbitol is preferably 0-50: 100-50.

[0042] The hydroxyl value of the polyether polyol (B2) is preferably 200 to 680 mg KOH / g, more preferably 350 to 500 mg KOH / g. The number average molecular weight of the polyether polyol (B 2) is preferably 500 to 1 700, more preferably 670 to 1 000.

[0043] The polyether polyol (B 3) is obtained by adding ethylene oxide and / or propylene oxide to schucrose as an initiator.

[0044] Here, the mass ratio ([EO]: [PO]) of ethylene oxide and propylene oxide added to sucrose is preferably 0-50: 100-50.

[0045] The hydroxyl value of the polyether polyol (B3) is preferably 300 to 600 mg KOH / g, more preferably 380 to 450 mg KOH / g. The number average molecular weight of the polyether polyol (B 3) is preferably 700 to 1,500, and more preferably 1,000 to 1,200.

[0046] The component [B] is composed of only “at least one selected from polyether polyol (B 1), polyether polyol (B 2) and polyether polyol (B 3)”. However, other polyols may be contained within a range not exceeding 50% by mass.

[0047] Examples of such polyols include polyether polyols [excluding those corresponding to the above (B 1), (B 2) and (B 3). ] Polyester polyol, Polycarbonate polyol, Polyolefin polyol, Animal and plant polyol, Low molecular weight polyol with a molecular weight of 300 or less that functions as a chain extender And polymer polyols, halogen-containing polyols, phosphorus-containing polyols, and phenol-based polyols. Of these, polyether polyols are preferred.

[0048] The total proportion of the polyether polyol (B 1), the polyether polyol (B 2) and the polyether polyol (B 3) in the component (B) is usually 50% by mass or more, preferably 7 5% by mass or more, particularly preferably 100% by mass. When the total proportion is less than 50% by mass, the formed rigid polyurethane slab foam is inferior in flame retardancy and dimensional stability (see Comparative Example 4 described later).

<[C] Component> The foam-forming composition used in the present invention is a water foaming composition containing water ([C] component) as a foaming agent. The content of water as the component [C] is preferably 2 to 10 parts by mass, more preferably 3 to 7 parts by mass with respect to 100 parts by mass of the component [B]. If this content is excessive, the density of the hard polyurethane slab foam formed will be lower than the desired density (weight reduction), leading to insufficient strength and reduced dimensional stability. Will cause the rigid polyurethane slab foam to be brittle. On the other hand, if the content is too small, foaming becomes insufficient and the density increases, resulting in an increase in cost.

<Optional Components> The foam-forming composition used in the present invention may contain components other than the essential components as long as the effects of the present invention are not impaired. Examples of such optional components include flame retardants, foam stabilizers, antioxidants, catalysts, fillers, stabilizers, and colorants.

[0051] "Flame retardants" that can be used as optional components include organic halogen compounds, phosphorus compounds, (iso) cyanuric acid derivative compounds (halogen-free nitrogen-containing compounds), and (iso) cyanuric acid derivative compounds And nitrogen-containing compounds (halogen-free nitrogen-containing compounds) and inorganic compounds.

[0052] Here, "organic halogen compounds" include tetrabromobisphenol A (TBBA), dibromoneopentyl glycol, decabromodiphenyl. Oxide (DBDPO), Hexasuboromocyclododecane (HBCD), Tribromophenol (TBP), Ethylene bistetrabromophthalimide, Brominated polystyrene, TBBP A epoxy oligomer, TBBPA bisdibromopropyl ether, Ethylene bis pentapromo Diphenyl and the like can be exemplified.

[0053] The "phosphorus compounds" include ammonium polyphosphate compounds such as the condensation product of ammonium orthophosphate and urea, trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate, trioctyl phosphate. , Phosphate esters such as triphenyl phosphate, tricresyl phosphate and octyl diphenyl phosphate, condensed phosphate esters such as high molecular weight polyphosphate, tris (chloropropyl) phosphate (TCP P), Examples thereof include halogen-containing phosphate esters such as tris (diclonal propyl) phosphate and tris (dibromoneopentyl) phosphate.

[0054] In addition, "(iso) cyanuric acid derivative compound (non-halogen-containing nitrogen-containing compound)" includes melamine, melamine sulfate, melamine phosphate, melamine polyphosphate, methylol melamine, trian ester of cyanuric acid, triane of cyanuric acid. Cyanuric acid derivatives such as ethyl ester, ammelin, ammelide, 2,4,6_trioxycyanidine and melamine cyanurate; Can be illustrated.

[0055] Further, as "nitrogen-containing compounds other than (iso) cyanuric acid derivative compounds (halogen-free nitrogen-containing compounds)", dicyandiamide, dicyandiamididine, guanidine, guanidine sulfamate, and diguanide, etc. Examples include cyanamide derivatives; and urea derivatives such as urea, dimethylol urea, diacetyl urea, trimethyl urea, and N-benzoyl urea. [0056] As the "inorganic compound", magnesium hydroxide, aluminum hydroxide, sodium tetraborate, magnesium phosphate, sodium diphosphate, zinc phosphate, antimony trioxide, antimony pentoxide, and guanidine nitrogenated, Examples include red phosphorus.

[0057] Examples of the “foam stabilizer” used as an optional component include “S Z — 1 1 7 1”, “S Z — 1 649”, “S Z — 1 666”, “S Z — 1 694”, “ `` S Z_ 1 67 1 '', `` S Z_ 1 7 1 1 '', `` S Z_ 1 1 27 '', `` S Z_ 1 9 1 9 '', `` S Z_ 1 7 1 8 '', `` S Z_ 1 692 '', `` S F_2936 F, SF-2937 F, SF 2938 F, SH-1 92 (above, manufactured by Toray Dow Corning Co., Ltd.), B-8444, B-8460 , "B_8465", "B_8870", "B_887 1", "B_823 2", "B_8466", "B_8467" (Gold Schmidt) "F_373" , "X20_1748 S", "X20_1874", "X20_5042", "X20_5051", "X20_5043" (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0058] "Antioxidants" that can be used as optional components include phenolic antioxidants, phosphorus antioxidants, and phenolic antioxidants.

[0059] Here, as the "phenolic antioxidant", pentaerythrityl 1-tetrakis [methylene_3_ (3,5-di-t_butyl_4-hydroxyphenyl) propionate], 3, 9_bis {2_ [3-(3_C_Butyl_4 —Hydroxy-5-methylphenyl) propionyloxy] — 1, 1, 1-dimethylethyl} -2, 4, 8, 1 0-tetraoxapyro [5, 5] undecane, 1,3,5-tris (2,6-dimethyl_3-hydroxy_4_t-butylbenzyl) isocyanurate, 1,3,5-tris (3,5_di_ce_butyl_4-hydroxybenzyl) , 4, 6_trimethylbenzene, 1,3,5-tris (3,5-di-t_butyl_4-hydroxybenzyl) iso Cyanurate, bis (3,5-di-t_butyl_4-hydroxybenzylethyl phosphonate) calcium, 2,6-di-t_butyl_p_cresol, ptyrylated hydroxyanisole, 2 , 6-di _ t _ butyl _ 4 _ethyl phenyl, steryl — β _ (3, 5—di _ t _ butyl _ 4-hydroxyphenyl) propionate, 2, 2 '—methylene bis (4 _methyl_ 6_C_Butylphenol), 2, 2'-Methylenebis (4-Ethyl_6_t_Butylphenol), 4, 4'-Chobis (3_Methyl_6_t_Butylphenol), 4, 4 '—Butylidenebis (3 _ methyl _ 6 _ t _ butylphenol), 3, 9-bis [1, 1 — dimethyl 1 2— ίβ— (3 — t — butyl 1 -4-hydroxy 1 5 _ methyl phenyl) propionyloxy ] Ethyl] 2, 4, 8, 1 0—Tetraoxaspiro [5.5] undecane, 1, 3— Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-1,2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene , Tetrakis [Methylene _ 3 _ (3,, 5 '— Di _ t _ butyl 1 4' — Hydroxyphenyl) propionate] Methane, bis [3, 3 '— Bis (4' — Hydroxy 1 ' (t-Ptylphenyl) Petite Lick Acid] Glycol ester, 1, 3, 5—Tris (3 ′, 5′-di_t_butyl-1-4′-hydroxybenzyl) S-triazine-1,2,4,6- (1 H, 3 H, 5 H) trions, tocopherols and the like can be exemplified.

Examples of “phosphorus antioxidants” include phosphorus stabilizers such as alkyl phosphites, alkyl allylic phosphates, allylic phosphites, alkyl phosphonates, allylic phosphonates. (Tridecyl) Pentaerysuri! Rudiphosphite, tris (2,4-di-t_butylphenyl) phosphite, distearyl pentaerythritol! Didiphosphite, tetrakis (2,4-di-t_butylphenyl) 1,4'-biphenylene phosphonate, bis (2,4-di-t_butylphenyl) pentaerythri! Rudiphosphite, bis (2,6-di-t-butyl) 4_methylphenyl) Pentaerythri! Rudiphosphite, 1, 1, 3_ Tris (2_Methyl_4_Ditridecyl Phosphate_5_t-Phenylphenyl) Butane, Triphenylphosphite, Diphenylisodecyl Phosphate, 4, 4'-Butylidene Bis (3_methyl_6_t_butylphenyl ditridecyl) phosphite, cyclic neopentanetetraylbis (octadecyl phosphite), tris (nonylphenyl) phosphite, tris (monononylphenyl) phosphite Tris (dinonyl phenyl) phosphate, diisodecyl pentaerythri! Rudiphosphite, 9, 1 0—Dihydro_ 9—Oxa 1 0_ Phosphaphenanthrene 1 0_ Oxide, 1 0— (3,5—Di_t_butyl_ 4-hydroxybenzyl) 1 9, 1 0—Dihydro_ 9—Oxa 1 0_ Phosphaphenanthrene 1 0—Oxide, 1 0—Desyloxy 9, 10 0—Dihydro 9_Oxa _ 1 0_ Phosphaphenanthrene, Tris (2,4-di-t_butylphenyl) phosphate, cyclic neopentanetetraylbis (2,

4-di-t_butylphenyl) phosphite, cyclic neopentante trilebis (2,6-di-t_butyl_4_methylphenyl) phosphite, 2,2-methylenebis (4,6-di-t_butylphenyl) An example is octyl phosphate.

[0061] In addition, as "io antioxidant", distearyl 1, 3, 3'-thiodipropionate, pentaeryth! Lutetrakis (3-laurylthiopropionate), dilauryl-1,3'-thiodipropionate, dimyristyl-1,3'-thiodipropionate, ditridecyl-1,3'-thiodibu oral pionate, thiodipropion Dilauryl acid etc. can be illustrated

[0062] “Catalysts” that can be used as optional components include triethylenediamine (TEDA), tetramethylhexamethylenediamine (TMHMDA), pentamethyljetylenetriamine (PMD E TA), dimethylcyclohexylamino (DMCHA), Bisdimethylaminoethyl ether (BDMA EA), Amine compounds such as N-methylimidazole, trimethylaminoethylpiperazine, tripropylamine, triethylamine, N-methylmorpholine, tin compounds such as dibutyltin diacetate and dibutyltin dilaurate, acetylethylacetone metal salt, etc. Urethanes typified by metal complex compounds, reactive amine catalysts such as dimethylethanolamine (DMEA), N, N, N'-trimethylaminoethylethanolamine, N, N-dimethylaminoethoxyethanol A catalyst can be mentioned. The content of the catalyst is preferably 2.5 parts by mass or less, more preferably 1.0 part by mass or less with respect to 100 parts by mass of the [B] component.

<Production Method> The production method of the present invention is a method for producing a rigid polyurethane slab foam by reacting a foam-forming composition and free-foaming in a state where the top surface is open. The foam-forming composition is, for example, a two-part curable composition composed of a first liquid composed of the component [A] and a second liquid obtained by mixing the component [B], the component [C] and an optional component. Used as a composition. The foam-forming composition is also a three-part liquid composed of a first liquid composed of the component [A], a second liquid composed of the component [B], and a third liquid composed of the component [C] and an optional component. It may be used as a curable composition.

[0064] An example of a specific production method is as follows. The first liquid ([A] component) and the second liquid ([B] component, [C] component and polyol mixture containing the optional component) are publicly known. A foam-forming composition (foamable mixture) is prepared by mixing with an agitating mixer (foaming machine), which is poured into a mold with the top surface open to allow free foaming, and a slab (block) ) Can be mentioned as a method of curing and molding (discontinuous method).

[0065] Here, the bottom area inside the mold for determining the size of the slab formed by the discontinuous method is usually 0.25 m ² (for example, 0.5 m X O. 5 m) or more, preferably Is defined as 0.25 m ^{2 to} 6. Om ² (eg, 2. OmX 3. Om). In addition, the height inside the mold that determines the size (thickness) of the slab is usually 0.3 m or more, preferably 0.3 to 1. Om. According to the manufacturing method (discontinuous method) of the present invention, a large size formed using such a mold [(0.25 to 6. Om ² ) X (0.3 to 1. Om) ] Even if it is a slab form, scorch is not generated inside.

[0066] Further, as another example of the production method, the first liquid (the component [A]) and the second liquid (the polyol mixture containing the component [B], the component [C] and an optional component) are publicly known. A foam-forming composition (foamable mixture) is prepared by mixing with a stirring mixer (foaming machine), and this is continuously discharged into a continuous line with the top surface open to allow free foaming. A method of continuous molding (continuous method) can be mentioned.

[0067] Here, the width of the continuous line that determines the size of the slab formed by the continuous method is usually 0.5 m or more, and preferably 0.5 to 3. Om. And according to the manufacturing method (continuous method) of this invention, even if it is a slab foam of the big size formed by such a continuous line, a scorch is not generated in the inside.

<Rigid polyurethane slab foam of the present invention> The rigid polyurethane slab foam of the present invention is obtained by the production method of the present invention. The rigid polyurethane slab foam of the present invention is a slab of a large size [for example, a slab of (0.25 to 6. Om ² ) X (0.3 to 1. Om) formed by a discontinuous method, Or long slabs with a width of 0.5 to 3. Om and a thickness of 0.3 to 1. Om formed by a continuous method], no scorch is generated inside. Moreover, this rigid polyurethane slab foam has low thermal conductivity, can maintain excellent flame retardance over time, and is excellent in dimensional stability. The rigid polyurethane slab foam of the present invention has a closed cell structure, specifically, a closed cell ratio measured in accordance with ASTM D 2856 exceeds 75%. When the closed cell ratio exceeds 75%, the rigid polyurethane slab foam has excellent thermal conductivity (excellent thermal insulation).

<Insulating material for piping> The insulating material for piping of the present invention is obtained by cutting the rigid polyurethane slab foam of the present invention. Figure 1 shows the heat insulating material for piping according to the present invention. FIG. 2 is a perspective view showing an example in which a state in which the heat insulating material shown in FIG. 1 is attached to a pipe is partially broken. The heat insulating materials 1 A and 1 B shown in FIG. 1 have a shape formed by dividing (halving) a cylindrical body in the vertical direction. The heat insulating materials 1 A and 1 B are formed by cutting a hard slab foam formed by the manufacturing method of the present invention. “Cutting” includes “cutting”. As shown in FIG. 2, the heat insulating materials 1 A and 1 B are arranged so as to cover the surface of the pipe P, and are fixed by the securing means 3 in this state. The outer surfaces of the heat insulating materials 1 A and 1 B may be covered with a gas impermeable sheet or film. This prevents the gas (carbon dioxide) in the bubbles that make up the foam from being replaced by air (having a higher thermal conductivity than carbon dioxide). As a result, the initial thermal insulation can be maintained. . As such a “gas-impermeable sheet or film”, a laminating film having an aluminum layer as one layer can be exemplified.

[0070] Since the heat insulating materials 1 A and 1 B are formed from a hard slab foam formed from the foam-forming composition, there are defects in appearance and strength due to scorch inside the slab. Absent. In addition, it has low thermal conductivity and excellent heat insulation and heat retention, as well as excellent flame retardancy and dimensional stability.

[0071] The shape of the heat insulating material for piping according to the present invention and the method of mounting the piping on the piping are not limited to those described above.

Example

Examples of the present invention will be described below, but the present invention is not limited to these. In the following, “%” and “part” mean “% by mass” and “part by mass”, respectively, unless otherwise specified. The modifying agents used in the following preparation examples are the following compounds.

[0073] (1) Specific modifier (d 1): polyester polyol obtained by reacting diethylene glycol and orthophthalic acid (functional group number = 2, hydroxyl value = 2 7 O mg KOH / g, number average molecular weight = 4 1 6). (2) Specific modifier (d 2): Reacts diethylene glycol with orthophthalic acid and adipic acid. Polyester polyol obtained by the above (functional group number = 2, hydroxyl value = 230 mg KOH / g, number average molecular weight = 488). (3) Specific modifier (d 3): Polyester polyol obtained by reacting diethylene glycol and orthophthalic acid (functional group number = 2, hydroxyl value = 255 mg KOH / g, number average molecular weight = 440).

[0074] (4) Comparative modifier (d 4): polyester polyol obtained by reacting 3-methyl_1,5_pentanediol with S-methyl mono (5-valerolactone ( Number of functional groups = 2, hydroxyl value = 1 1 2 mg KOH / g, number average molecular weight = 1 000) (5) Comparative modifier (d 5): 3-methyl-1,5-pentanediol; _ (Polyester polyol obtained by reacting with 5-valerolactone (functional group number = 2, hydroxyl value = 56 mg KOH / g, number average molecular weight = 2000) (6) Comparative modifier (d6 ): Polypropylene glycol (functional number = 2, hydroxyl value = 281 mg KOH / g, number average molecular weight = 400) (7) Comparative modifier (d 7): Reaction of diethylene glycol with orthophthalic acid Polyester polyol obtained by mixing (number of functional groups = 2, hydroxyl value = 31 5 mg KOH / g, number average molecular weight = 356) (8) Modification for comparison Agent (d8): Polyester polyol obtained by reacting diethylene glycol and orthophthalic acid (functional group number = 2, hydroxyl value = 400 _§0 H / g, number average molecular weight = 281) (9) Comparative modifier (D9): Polyester polyol obtained by reacting 1,4-butanediol with adipic acid (functional number = 2, hydroxyl value = 1 1 2 mg KOH / g, number average molecular weight = 1 00 00) .

[Preparation Example 1] In a reaction vessel equipped with a stirrer, a thermometer, a cooler, and a nitrogen introducing tube, MD I (a 1) (4, 4 '_MD I is 70 according to the formulation shown in Table 1 below. 2) 4 parts are charged and heated to 60 ° C, then a specific modifier (d 1) 1 2. 4 parts are added, and the system is heated to 60 ° C. MD I was denatured by stirring at C for about 2 hours. Next, 55.2 parts of polymeric MDI (a 2) was added to and mixed with the reaction product [modified MDI]. Thus, 10.00 parts of [A] component (hereinafter referred to as “[A_1] component”) composed of a modified polyisocyanate having an NCO content of 25.4% was obtained.

[0076] The obtained [A_1] component exhibited a clear liquid without turbidity, and its viscosity (25 ° C) was 1, 05 OmPa · s. this ! : A _ 1] The proportion of dinuclear substances (unmodified MDI molecules) contained in the component was 40%. In addition, the ratio of the binuclear substance in the total amount (87.6 parts) of M D I (a 1) subjected to denaturation treatment and polymeric M D I (a 2) mixed after denaturation is 62%.

[0077] [Preparation Example 2] According to the formulation shown in Table 1 below, the amount of MDI (a 1) charged was changed to 36.3 parts, and the amount of specific modifier (d 1) added was 8.5 parts. [A] component (hereinafter referred to as “[A_2] component”) consisting of a modified polyisocyanate having an NCO content of 27.5%, except that MD I was modified and modified. I got 1 00. 0 parts.

[0078] The obtained [A_2] component exhibited a clear liquid without turbidity, and its viscosity (25 ° C) was 284 mPa · s. The content of dinuclear (unmodified MDI molecule) in this [A_2] component was 48%. In addition, the ratio of dinuclear body in the total amount (91.5 parts) of M D I (a 1) subjected to denaturation treatment and polymeric M D I (a 2) mixed after denaturation is 64%.

[0079] [Preparation Example 3] According to the formulation shown in Table 1 below, the amount of MDI (a 1) charged was changed to 31.6 parts, and a specific denaturing agent (d 1) was used instead of the specific denaturing agent (d 1). d 2) Consisting of Preparation Example 1 except that MDI was modified by adding 13.2 parts, 1 \ 100 content of 25.4% modified polyisocyanate [A] Ingredient (hereinafter referred to as “[A_3] ingredient”) 1 00. 0 parts were obtained.

[0080] The obtained [A_3] component was not turbid and exhibited a transparent liquid, and its viscosity (25 ° C) was 76 OmPa · s. In this [A_3] component, the content of dinuclear body (unmodified MDI molecule) was 40%. In addition, the ratio of dinuclear body in the total amount (86.8 parts) of M D I (a 1) subjected to denaturation treatment and polymeric M D I (a 2) mixed after denaturation is 62%.

[Preparation Example 4] According to the formulation shown in Table 1 below, the amount of MD I (a 1) charged was adjusted. 32. Changed to 0 part, and instead of the specific modifier (d 1), the specific modifier (d 3) 1 2. 8 咅 | 5

In the same manner as in Preparation Example 1, except that MDI was modified by adding [A] component (hereinafter referred to as “[A_4] component”) composed of a modified polyisocyanate having an NCO content of 25.4%. 1 00. 0 parts were obtained.

[0082] The obtained [A_4] component was not turbid and exhibited a transparent liquid, and its viscosity (25 ° C) was 91 OmPa · s. The content of dinuclear (unmodified MDI molecule) in this [A_4] component was 40%. In addition, the ratio of the binuclear substance in the total amount (87.2 parts) of M D I (a 1) subjected to denaturation treatment and polymeric M D I (a 2) mixed after denaturation is 62%.

[0083] [Preparation Example 5] According to the formulation shown in Table 1 below, the amount of MDI (a 1) charged was changed to 32.0 parts, and the amount of specific modifier (d 1) added was 12.8. The modified reaction product [modified MD I] was changed to 5 parts with polymeric MD I (a 2) 55.2 parts and triethyl phosphate (TEP) 3.0 [A] component (hereinafter referred to as “[A_5] component”) 1 consisting of a modified polyisocyanate having a NCO content of 24.5%, except that part was added and mixed. 03. 0 parts were obtained.

[0084] The obtained [A_5] component was not turbid and exhibited a transparent liquid, and its viscosity (25 ° C) was 1, 02 OmPa · s. this ! : A_5] The content of dinuclear (unmodified MDI molecule) in the component was 38%. In addition, the ratio of dinuclear body in the total amount (87.2 parts) of M D I (a 1) subjected to denaturation treatment and polymeric M D I (a 2) mixed after denaturation is 62%.

[0085] [Preparation Example 6] According to the formulation shown in Table 1 below, the amount of MDI (a 1) charged was changed to 31.0 parts, and the amount of specific modifier (d 1) added was 13.8. [A] component (hereinafter referred to as “[A_6] component”) consisting of a modified polyisocyanate having an NCO content of 24.7%, except that MD I was modified by changing to the same part. ) 1 00. 0 parts were obtained.

[0086] The obtained [A_6] component is a clear liquid with no turbidity, and its viscosity (25 ° C) was 1, 90 OmP a ■ s. this ! : A _ 6] The content of dinuclear (unmodified MDI molecule) in the component was 36%. In addition, the ratio of the binuclear substance in the total amount (86.2 parts) of MDI (a 1) subjected to denaturation treatment and polymeric MDI (a 2) mixed after denaturation is 62%.

[0087] [Preparation Example 7] According to the formulation shown in Table 1 below, the amount of MD I (a 1) charged was changed to 28.9 parts, and a comparative modifier (d 1) was used instead of the specific modifier (d 1). d 4) 1 5. Modified polyisocyanate with an NCO content of 25.4% (hereinafter referred to as “[a_7] component”) in the same manner as in Preparation Example 1 except that MDI was modified by adding 9.59 parts. I got 1 00. 0 parts.

[0088] The obtained [a_7] component was not turbid and exhibited a transparent liquid, and its viscosity (25 ° C) was 45 OmPa · s. The content of dinuclear substance (unmodified MDI molecule) in this [a_7] component was 43%. In addition, the ratio of the binuclear body in the total amount (84.1 parts) of M D I (a 1) subjected to denaturation treatment and polymeric M D I (a 2) mixed after denaturation is 61%.

[Preparation Example 8] According to the formulation shown in Table 1 below, the amount of MD I (a 1) charged was adjusted.

27. Change to 1 part and replace with the specific denaturant (d 1). Comparative denaturant (d 5) 1 As in Preparation Example 1, except that MDI was denatured by adding 7 parts. Thus, a modified polyisocyanate having an NCO content of 25.4% (hereinafter referred to as “[a_8] component”) 10.00 parts was obtained.

[0090] The obtained [a_8] component was not turbid and exhibited a transparent liquid, and its viscosity (25 ° C) was 49 OmPa · s. The content of dinuclear (unmodified MDI molecule) in this [a_8] component was 45%. In addition, the ratio of binuclear substances in the total amount (82.3 parts) of M D I (a 1) subjected to denaturation treatment and polymeric M D I (a 2) mixed after denaturation is 60%.

[0091] [Preparation Example 9] According to the formulation shown in Table 1 below, the amount of MD I (a 1) charged was

34. Changed to 3 parts, instead of the specific modifier (d 1), comparative modifier (d 6)

1 Modified polyisocyanate with 25.4% NCO content (hereinafter referred to as “[a_9]”) in the same manner as in Preparation Example 1 except that 0.5 part was added to modify MDI. Ingredient ". 1 00. 0 parts were obtained.

[0092] The obtained [a_9] component was not turbid and exhibited a transparent liquid, and its viscosity (25 ° C) was 780 mPa · s. The content of dinuclear (unmodified MDI molecule) in this [a_9] component was 38%. In addition, the ratio of dinuclear bodies in the total amount (89.5 parts) of M D I (a 1) subjected to denaturation treatment and polymeric M D I (a 2) mixed after denaturation is 63%.

[0093] [Preparation Example 1 0] According to the formulation shown in Table 1 below, the amount of MDI (a 1) charged was changed to 39.0 parts, and the amount of specific modifier (d 1) added was 5.8. The modified polyisocyanate (hereinafter referred to as “[a — 1 0] component”) having an NCO content of 29.0 <½, in the same manner as in Preparation Example 1, except that MDI was modified by changing to a part. 1 00. 0 parts were obtained.

[0094] The obtained [a_10] component exhibited a clear liquid without turbidity, and its viscosity (25 ° C) was 138 mPa · s. The content of dinuclear (unmodified MDI molecule) in this [a_10] component was 54%. In addition, the ratio of dinuclear bodies to the total amount (94.2 parts) of M D I (a 1) subjected to denaturation treatment and polymeric M D I (a 2) mixed after denaturation is 65%.

[0095] [Preparation Example 1 1] Polymeric MDI (a 2) used in Preparation Examples 1 to 10 (binuclear = 40%, trinuclear = 27%, tetranuclear = 9%, pentanuclear or Hexanuclear = 5%, polynuclear over 7 nuclei = 19%: NCO content = 30.9%, viscosity (25 ° C) = 1 70 m Pa ■ s). This is hereinafter referred to as “[a_ 1 1] component”.

[0096] [Preparation Example 1 2] In accordance with the formulation shown in Table 1 below, the amount of MDI (a 1) charged was changed to 30.2 parts, and the amount of specific modifier (d 1) added was 1 4. A modified polyisocyanate having an NCO content of 23.8 <½ (hereinafter referred to as “[a — 12] component”) was prepared in the same manner as in Preparation Example 1, except that MDI was modified by changing to 6 parts. ) 1 00. 0 parts were obtained.

[0097] The obtained [a_12] component was not turbid and exhibited a transparent liquid, but its viscosity (25 ° C) was as high as 3,70 OmPa-s. This [a -1 2] The content of dinuclear (unmodified MDI molecule) in the component was 35%. In addition, the ratio of dinuclear body in the total amount (85.4 parts) of MD I (a 1) subjected to denaturation treatment and polymeric MD I (a 2) mixed after denaturation is 61%.

[0098] [Preparation Example 1 3] According to the formulation shown in Table 1 below, the amount of MDI (a 1) charged was changed to 33.0 parts, and a comparative denaturant was used instead of the specific denaturant (d 1). (D7) 11.0 part by weight of a modified polyisocyanate having an NCO content of 25.4% in the same manner as in Preparation Example 1, except that MDI was modified by adding 1.18 parts. Got.

[0099] The obtained modified polyisocyanate exhibited a cloudy liquid and was unsuitable as a component of the foam-forming composition. The modified polyisocyanate had a viscosity (25 ° C) of 450 mPa · s. The content of dinuclear body (unmodified MDI molecule) in this modified polyisocyanate was 39%. In addition, the ratio of dinuclear body in the total amount (88.2 parts) of MD I (a 1) subjected to denaturation treatment and polymeric MD I (a 2) mixed after denaturation is 62 <½.

[0100] [Preparation Example 1 4] According to the formulation shown in Table 1 below, the amount of MDI (a 1) charged was changed to 34.3 parts, and a comparative denaturant was used instead of the specific denaturant (d 1). (D8) 10.5 parts of modified polyisocyanate having a NCO content of 25.4% in the same manner as in Preparation Example 1 except that MDI was modified by adding 10.5 parts. Got.

[0101] The resulting modified polyisocyanate was in the form of a cloudy liquid and was unsuitable as a component of the foam-forming composition. The viscosity (25 ° C) of this modified polyisocyanate was 1, 05 OmPa-s. The content of dinuclear (unmodified MDI molecule) in this modified polyisocyanate was 38%. In addition, the ratio of dinuclear body in the total amount (89.5 parts) of MD I (a 1) subjected to denaturation treatment and polymeric MD I (a 2) mixed after denaturation is 63%. [0102] [Preparation Example 15] According to the formulation shown in Table 1 below, the amount of MDI (a 1) charged was changed to 28.9 parts, and a comparative denaturant was used instead of the specific denaturant (d 1). (D9) 15.9 parts, modified polyisocyanate having a NCO content of 25.4%, in the same manner as in Preparation Example 1, except that MDI was modified by adding 5.99 parts. Got.

[0103] The obtained modified polyisocyanate was in the form of a turbid liquid and was unsuitable as a component of the foam-forming composition. The modified polyisocyanate had a viscosity (25 ° C) of 400 mPa · s. The content of dinuclear (unmodified MDI molecule) in this modified polyisocyanate was 43%. In addition, the ratio of dinuclear body in the total amount (84.1 parts) of MD I (a 1) subjected to denaturation treatment and polymeric MD I (a 2) mixed after denaturation is 61%.

[0104]

1

* 1) MD I (a 1): M D I (binuclear body) containing 4, 4 '_ M D I in a proportion of 70% or more. * 2) Polymeric MD I (a 2): Polymeric MDI for post-addition (dinuclear = 40%, trinuclear = 27%, tetranuclear = 9%, pentanuclear or hexanuclear = 5% Heteronuclear polynuclear = 1 9%: NCO content = 30.9

%) <Example 1> According to the formulation shown in Table 2 below, a polyol mixture containing (B) component, (C) component and optional component (liquid temperature = 30 ° C) 1 33. [A_ 1] obtained in Preparation Example 1 (liquid temperature = 20 ° C) 1 91.0 parts (N CO index = 100) were mixed using a high-pressure foaming machine. The composition was prepared. The composition discharged from the low-pressure foaming machine was poured into a wooden mold with an open top surface with internal dimensions of 600 mm x 600 mm x 60 Omm, and the reaction time (cream time and rise time) in the foaming and curing process was measured. . The results are also shown in Table 2. After 1 hour from the start of the stirring and mixing operation, the demolding operation was performed to obtain a rigid polyurethane slab foam.

<Examples 2 to 6> [0107] According to the formulation shown in Table 2 below, the polyol mixture containing the component [B], the component [C] and the optional component, and the component [A] In the same manner as in Example 1 except that the blending ratio (amount) shown in Table 2 was used, stirring and mixing operation of the polyol mixture and the component [A] (preparation of foamable composition) The composition was injected, the reaction time was measured (results are shown in Table 2 below), and demolding was performed to obtain each of the rigid polyurethane slab foams.

[0108]

2

[Notes on Table 2 (same in Table 3 below)] * 3) Polyol (B 1 _ 1): Polyterpolyol (B 1) obtained by adding EO and PO to toluenediamine, Number of functional groups = 4 Number average molecular weight = 561, Hydroxyl value = 40 Omg KOH / g, Viscosity (25 ° C.) = 20:00 OmPas [EO]: [PO] = 20: 80 (mass ratio). * 4) Polyol (B 2 _ 1): Polyether polyol (B2) made by adding PO to sorbitol — Functional group number = 6, Number average molecular weight = 874, Hydroxyl value = 385 mg KOH / g, Viscosity (25 ° C) = 8, 400 mPa's. * 5) Polyol (B 3 _ 1): Polyether polyol made by adding PO to sucrose, number of functional groups = 8, number average molecular weight = 1069, hydroxyl value = 420mg KOH / g, viscosity (25 ° C) = 28, OO OmP a 's. * 6) Flame retardant (TCP P): Tris (black mouth) Propyl) phosphate. * 7) Foam stabilizer (B— 8 4 6 0): “B_ 8 4 6 0” (Gold Schmidt). * 8) Antioxidant (1): Tetrakis [Methylene _ 3 _ (3,, 5 '— Di-tert-B

Chill-4'-hydroxyphenyl) propionate] Methane "Ilganox 1 0 1 0" (Ciba Specialty Specialty Chemicals). * 9) Antioxidant (2): Bis (tridecyl) pentaerythritol diphosphite “JP P — 13 R” (manufactured by Johoku Chemical Co., Ltd.).

[0110] <Comparative Example 1> In accordance with the formulation shown in Table 3 below, instead of the [A_1] component, the [a_7] component obtained in Preparation Example 7 1 9 1.0 part (NCO index = 1 0 0) was used in the same manner as in Example 1, except that the polyol mixture and [a 17] component were stirred and mixed (preparation of foamable composition), the composition injection operation, the reaction time Measurement (results are shown in Table 3 below) and demolding operation were performed to obtain a rigid polyurethane slab foam. This example is a comparative example using a modified polyisocyanate modified with a polyester polyol having a hydroxyl value of less than 1550 mg KOH / g.

[0111] <Comparative Example 2> According to the formulation shown in Table 3 below, instead of the [A_ 1] component, the [a _ 8] component obtained in Preparation Example 8 1 6 7.0 (NCO index = 1 In the same manner as in Example 1 except that 0) was used, the stirring and mixing operation (preparation of a foamable composition) of the polyol mixture and the [a 1 8] component, the injection operation of the composition, the reaction time Measurement (results are shown in Table 3 below) and demolding operation were performed to obtain a rigid polyurethane slab foam. This example is a comparative example using a modified polyisocyanate modified with a polyester polyol having a hydroxyl value of less than 1550 mg KOH / g.

[0112] <Comparative Example 3> In accordance with the formulation shown in Table 3 below, instead of the [A_1] component, the [a_9] component 1 91.0 parts obtained in Preparation Example 9 (NCO index = 1 0 0) was used in the same manner as in Example 1 except that the polyol mixture and the [a 1 9] component were stirred and mixed (preparation of a foamable composition), the composition injection operation, the reaction time Rigid (results are shown in Table 3 below) and demolding operation A polyurethane slab foam was obtained. This is a comparative example using a modified polyisocyanate modified with a polyether polyol.

[0113] <Comparative Example 4> In accordance with the formulation shown in Table 3 below, 33.4 parts of a polyol mixture containing a polyol component, a [C] component and an optional component, and [A_1] component 1 99.0 parts ( NCO index = 1 00), and the same procedure as in Example 1, except that the polyol mixture and the [A_ 1] component were stirred and mixed (preparation of a foamable composition), and the composition was injected. Operation and measurement of reaction time (results are shown in Table 3 below) and demolding operation were performed to obtain a rigid polyurethane slab foam. This is a comparative example in which the total proportion of polyether polyol (B 1), polyether polyol (B2) and polyether polyol (B3) in the entire polyol component is less than 50%.

[0114] <Comparative Example 5> In accordance with the formulation shown in Table 3 below, instead of the [A_ 1] component, the [a 1 0] component obtained in Preparation Example 10 1 9 11.0 parts (N CO index = 1 00), except that a polyol mixture and [a-10] component were stirred and mixed (preparation of foamable composition), composition injection operation, reaction time (The results are shown in Table 3 below) and demolding operation were performed to obtain a rigid polyurethane slab foam. This example is a comparative example using a modified polyisocyanate having an NCO content exceeding 28.0%.

[0115] <Comparative Example 6> According to the formulation shown in Table 3 below, instead of the [A_ 1] component, [a _ 1 1] obtained in Preparation Example 11 1 Ingredient 1 577.0 parts (N CO index = 1 00), and the same procedure as in Example 1 except that the polyol mixture and Ca-1 1] component were stirred and mixed (preparation of a foamable composition), the composition was poured, and the reaction Time measurement (results are shown in Table 3 below) and demolding operation were performed to obtain a rigid polyurethane slab foam. This example is a comparative example using unmodified polymeric MDI (NCO content = 30.9%).

[0116] <Comparative Example 7> According to the formulation shown in Table 3 below, instead of the [A_ 1] component, the [a_ 1 2] component obtained in Preparation Example 1 2 204.0 parts (N CO index = In the same manner as in Example 1 except that 100) was used, an agitation and mixing operation (preparation of foamable composition) of the polyol mixture and the [a-12] component was attempted. -1 2] The operation was stopped because the components could not be circulated in the piping and hoses of the foaming machine at the specified flow rate. This is a comparative example using a modified polyisocyanate (3, 70 OmPa-s) with an NCO content of less than 24.0%.

[Table 3]

* 1 1) Poly tal (b _ 1): Polyter polyol made by adding PO to glycerin, number of functional groups = 3, number average molecular weight = 600, hydroxyl value = 281 mg KOH / g, Viscosity (25 ° C) = 270 mP a 's. * 1 2) Polio

—L (b_2): Polyether polyol made by adding EO and PO to glycerin, number of functional groups = 3, number average molecular weight = 6000, hydroxyl value = 28 mg KOH / g, viscosity (25 ° C) = 1, 1 00mP a's. * 1 3) Polio

—Role (b_3): Polyetherpolyol obtained by adding PO to glycerin, number of functional groups = 3, number average molecular weight = 250, hydroxyl value = 673 mg KOH / g, viscosity (25 ° C) = 950 mPa's . * 1 0) Catalyst (T o yo o c a t

L 33): “TOYOCAT L 33” (manufactured by Tosohichi Corporation).

<Evaluation of Slab Form> Each of the rigid polyurethane slab foams (60 OmmX 60 OmmX 60 Omm) obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were removed from room temperature and then at room temperature. After standing for 24 hours, the following items (1) to (7) were measured and evaluated. For the slab foams of Comparative Example 5 and Comparative Example 6 in which the evaluation of (2) below is “X”, the following measurements (3) to (7) were not performed. The results are shown in Table 4 below.

[0120] (1) Density: In accordance with JIS K7222, the dimensions and mass of a test piece (20 OmmX 20 OmmX 20 Omm) cut out from a slab foam were measured to determine the density (kg / m ³ ).

[0121] (2) Presence / absence of internal scorch: The slab foam was cut and the inside was observed, and the occurrence of scorch was evaluated based on the following criteria. ■ “0”: No scorch is observed. ■ “△”: Scorch is slightly generated (the center of the foam is slightly browned). ■ “X”: The occurrence of a scorch is clearly recognized (the center of the foam has turned brown)

[0122] (3) Closed cell ratio: Using a test piece [3 OmmX 3 OmmX 1 3 Omm (foaming direction)] cut from the slab foam, the closed cell ratio (%) was measured according to AS TM D 2856. .

[0123] (4) Thermal conductivity: A slab foam was cut (sliced) parallel to the foaming direction to produce a test piece of 2 O Omm (foaming direction) X 200 mm X 25 mm. Then, it was measured using a thermal conductivity measuring device (to auto) according to JISA 1 4 1 2.

[0124] (5) Combustion test (initial value): The combustion distance and the combustion time were measured according to JI S A 95 111 and the flame retardancy of the slab foam was evaluated based on these.

[0125] (6) Combustion test (after time): Specimens cut from slab foam (1 3mmX 50mmX l 50m m) are left in an environment of temperature 23 ° C and relative humidity 50% for 30 days. In the same manner as 5), the burning distance and burning time were measured, and the flame retardancy of the slab foam after aging was evaluated based on these.

[0126] (7) Dimensional stability (measurement of volume change rate): The volume change when a test piece (5 Omm X 5 Omm X 5 Omm) cut out from a slab foam was allowed to stand in the following atmosphere for a certain period of time. Measurements were made to evaluate dimensional stability. ■ 80 ° CX for 2 days. ■ _20 ° CX for 2 days.

[0127]

4

Industrial applicability

[0128] The rigid polyurethane slab foam according to the present invention is suitably used as a raw material for producing products (particularly, heat insulating materials for various pipes) that are required for heat insulation and heat insulation. Is done.

Brief Description of Drawings

FIG. 1 is a perspective view showing an example of a heat insulating material for piping according to the present invention.

[FIG. 2] Explanatory drawing showing a state in which the heat insulating material shown in FIG. It is.

Explanation of symbols

1 A insulation. 1 B insulation. 3 Tightening means.

Claims

The scope of the claims

[1] [A] At least a part of a polymethylene polyphenyl isocyanate containing 30 to 80% by mass of diphenylmethane diisocyanate has a hydroxyl value of 150 to 300 mg K OH / a modified polyisocyanate having an NCO content of 24.0 to 28.0% obtained by modification with a modifying agent comprising g of polyester polyol; and [B] a polyol having toluenediamine as an initiator. 50 mass% or more in total of at least one selected from the polyether polyol (B 1), the polyether polyol (B2) using sorbitol as an initiator, and the polyether polyol (B3) using sucrose as an initiator A rigid polyurethane characterized by reacting a foam-forming composition containing a polyol component contained in a proportion; and [c] a foaming agent comprising water to allow free foaming with the top surface open. Method of manufacturing the emission slab form.

[2] The hydroxyl value of the modifier used to obtain the [A] component is 200 to 30 Omg KOH / g, and the NCO content of the [A] component is 24.5 to 27.5%. The method for producing a rigid polyurethane slab foam according to claim 1, wherein:

[3] The modifier used to obtain the component [A] is at least selected from ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and 3-methyl-1,5-pentanediol. The polyester polyol obtained from one polyhydric alcohol and at least one polybasic acid selected from orthophthalic acid, isophthalic acid, terephthalic acid and adipic acid. 2. A method for producing a rigid polyurethane slab foam according to 2.

[4] The polyester polyol obtained from diethylene glycol and orthophthalic acid and / or adipic acid is used as the modifier used to obtain the component [A]. The manufacturing method of the rigid polyurethane slab foam of description.

[5] The component [A] is a part of polymethylene polyphenyl polyisocyanate. The rigid polyurethane slab foam according to any one of claims 1 to 4, wherein the rigid polyurethane slab foam is obtained by mixing with the remainder of a polymethylene polypolysiloxane after being modified with the modifier. Manufacturing method.

[6] The rigid polyurethane slab according to claim 5, wherein a part of the polymethylene poly (polyisocyanate) subjected to the modification treatment is diphenylmethane diisocyanate (binuclear). Form manufacturing method.

[7] The component [B] includes polyether polyol (B 1), polyether polyol (B 2), and polyether polyol (B 3). 7. The method for producing a rigid polyurethane slab foam according to any one of 6 above.

[8] A rigid polyurethane slab foam obtained by the production method according to any one of claims 1 to 7.

[9] The polyurethane slab foam according to claim 8, wherein the foam-forming composition is formed by free foaming in a mold having an open top surface having a bottom area of 0.25 m ² or more.

[10] The polyurethane slab foam according to claim 8, wherein the foam-forming composition is formed by free-foaming the foam-forming composition continuously discharged at a width of 0.5 m or more on a continuous line with the top surface open.

[1 1] A heat insulating material for piping obtained by cutting the rigid polyurethane slab foam according to any one of claims 8 to 10.