A COMPOSITION FOR MANUFACTURING A POLYURETHANE FOAM

BACKGROUND OF THE INVENTION

Field of the Invention

[0001]

The present invention relates to a composition for manufacturing a polyurethane foam.

Background Art

[0002]

Rigid polyurethane foams have been used as heat insulation materials for a construction material, a cold storage warehouse, a bathtub, a piping, and the like, owing to its good heat insulation properties. When rigid polyurethane foams are used for, for example a heat insulation material of a construction material for a house or a building, the rigid polyurethane foam is manufactured by a method which involves mixing a component mainly comprising a polyol with a component mainly comprising a polyisocyanate in the presence of a foaming agent, a catalyst, and other auxiliary agents if needed, and the mixture is sprayed onto the target site such as a wall surface or a ceiling at the construction site of the house or building by means of a spraying machine etc., and foaming and curing the mixture.

[0003]

There is proposed a method of manufacturing a polyurethane foam using only water as the foaming agent. However, since the reaction activity of foaming between water as the foaming agent and the isocyanate group is generally low, the adhesiveness of the obtained polyurethane foam to the adherend was sometimes reduced. Also when HCFO (hydrochlorofluoroolefin), HFO (hydrofluoroolefin), and the like were used as the foaming agent, the adhesiveness to the adherend was sometimes impaired due to contraction (impairment of dimensional stability) of the polyurethane foam. Especially in the case where a polyurethane foam and a face material was subjected to integral molding and adhesiveness between the polyurethane foam and the face material was low, the polyurethane foam sometimes separated from the adherend face.

[0004]

With respect to the above -described problem of adhesiveness, Patent Document 1 for example discloses the use of a catalyst containing an amine compound and a specific imidazole compound for the manufacture of polyurethanes as a method to improve the adhesiveness etc., even when water was used as the foaming agent. Also, Patent Document 2 discloses the use of red phosphorus as a flame retardant in order to improve the adhesiveness of the polyurethane foam to a steel substrate. Patent Document 3 further discloses the use of a specific microcapsule as the foaming agent in order to improve the adhesiveness to the adherend.

[0005] In the meantime, as means to improve the adhesiveness between an inorganic material such as metal and a resin-coated film, it is known to treat the surface of the inorganic material with a silane coupling agent or add a silane coupling agent to the resin-coated film. For example, Patent Document 4 discloses the addition of the silane coupling agent to the resin-coated film when the coated film by a resin such as an epoxy resin, an urethane resin, and the like, is formed on the surface of the inorganic material.

[Patent Documents]

[0006]

[Patent Document 1] JP2009-215386A

[Patent Document 2] JP2018-80328A

[Patent Document 3] JP2008-133395A

[Patent Document 4] JP2005-314449A

SUMMARY OF THE INVENTION

[Problems to be Solved by the Invention]

[0007]

However, when the silane coupling agent is added to the resin-coated film, the physicality of the coated film can alter. In fact, Patent Document 4 teaches that the addition of the silane coupling agent would excessively increase the elastic modulus of the resin. Thus, silicone microparticles are required to apply in addition to the silane coupling agent so as to lower the elastic modulus (see Patent Document 4, paragraphs 0006-0011).

[0008]

Further, as far as the inventors know, there has not yet been an attempt to improve the adhesiveness of the polyurethane foam itself to the adherend by using a silane coupling agent.

[0009]

Therefore, one object of the present invention is to provide a composition for manufacturing a polyurethane foam, from which a polyurethane foam is obtainable having excellent adhesiveness to an adherend, particularly an inorganic material such as metal.

[Means for Solving the Problem]

[0010]

The inventors have now found that it is possible to obtain a polyurethane foam having excellent adhesiveness to an adherend, particularly an inorganic material such as metal is obtained when using a specific silane coupling agent. The present invention is based on such findings.

[0011]

According to the present invention, the followings are provided:

(1) A composition for manufacturing a polyurethane foam, comprising

a polyol, a polyisocyanate,

a silane coupling agent having a functional group capable of interacting with either one or both of said polyol and said polyisocyanate.

(2) The composition according to (1), wherein said functional group is an organic group comprising at least one hetero atom selected from a nitrogen atom, an oxygen atom, and a sulfur atom.

(3) The composition according to (1) or (2), wherein said functional group is an epoxy group, an amino group, an ureido group, an isocyanate group, or a mercapto group.

(4) The composition according to any one of (1) to (3), which comprises said silane coupling agent in an amount from 0.001 to 10% by weight based on the total amount of the composition.

(4’) The composition according to any one of (1) to (3), which comprises said silane coupling agent in an amount from 0.001 to 1% by weight based on the total amount of the composition.

(5) A polyurethane foam formed from the composition according to any one of (1) to (4) or (4’).

(6) A heat insulation material comprising the polyurethane foam according to (5).

(7) A method for manufacturing a polyurethane foam, comprising the step of mixing a polyol,

a polyisocyanate, and

a silane coupling agent having a functional group capable of interacting with either one or both of said polyol and said polyisocyanate.

(8) The method according to (7), wherein said mixing step is carried out by

mixing a component comprising said polyol and said silane coupling agent with a component comprising said polyisocyanate,

mixing a component comprising said polyol with a component comprising said polyisocyanate and said silane coupling agent,

mixing a component comprising said polyol and said silane coupling agent with a component comprising said polyisocyanate and said silane coupling agent, or

mixing a component comprising said polyol, a component comprising said polyisocyanate, and a component comprising said silane coupling agent.

[Effect of the Invention]

[0012]

According to the present invention, there can be provided a composition from which a polyurethane foam is obtained having excellent adhesiveness to an adherend, particularly an inorganic material such as metal. [Mode for Carrying out the Invention]

[0013]

<Composition for manufacturing a polyurethane foam>

The composition for manufacturing a polyurethane foam of the present invention comprises a polyol, a polyisocyanate, and a silane coupling agent. Hereinafter is explained each component which constitutes the composition for manufacturing a polyurethane foam of the present invention.

[0014]

< Polyol >

There is no particular limitation to the compound used as the polyol contained in the composition for manufacturing a polyurethane foam of the present invention, as long as it is a compound having two or more hydroxyl groups in one molecule, examples of which including polyester polyols, polyether polyols, polymer polyols, phenol resin based polyols, Mannich polyols, etc. which are described in "Handbook of Polyurethane Resin" edited by Keiji Iwata (September 25, Showa 62, issued by Nikkan Kogyo Shimbun, LTD.). Each of these may be used singularly, or two or more can be mixed for use. Amongst these polyols, polyether based polyols such as poly ether polyols, polymer polyols, and Mannich polyols is preferable in view of hydrolysis resistance of the polyol itself and stability in reaction with the polyisocyanate component.

[0015]

As the polyether polyol, firstly mentioned is a polyoxyalkylene based polyol which can be manufactured by using a starting material including a compound having two or more active hydrogen-containing groups such as hydroxyl groups, primary amino groups, secondary amino groups, and the like and subjecting alkylene oxide to ring-opening addition reaction.

[0016]

The starting material of the polyoxyalkylene based polyol includes polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropyrene glycol, 1 ,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, diglycerine, sugar, sucrose, dextrose, and sorbitol, alkanolamines such as ethanolamine, diethanolamine, triethanolamine, and methyldiethanolamine, polyamines such as ethylenediamine, tolylenediamine, diethyltoluenediamine, 1,3-propanediamine, 1, 6-hexanediamine, isophorone diamine, diethylenetriamine and triethylene pentamine, polyphenols such as bisphenol A, bisphenol F, resorcinol, and hydroquinone, and modifications thereof, which each of these may be used singularly, or two or more can be mixed for use.

[0017]

When manufacturing the polyoxyalkylene based polyol, alkylene oxide which is subjected to the ring-opening addition reaction includes ethylene oxide, propylene oxide, 1,2- butylene oxide, 2,3- butylene oxide, styrene oxide, and the like, which each of these may be used singularly, or two or more can be mixed for use.

[0018]

Polymer polyols include those having polymer microparticles such as polyacrylonitrile microparticles and polystyrene microparticles dispersed in the polyoxyalkylene based polyol.

[0019]

Mannich polyols can be manufactured by condensation reaction of phenols, aldehydes, alkanol amines, and the like and further subjecting alkylene oxide such as ethylene oxide and propylene oxide to the ring-opening addition reaction if necessary.

[0020]

Examples of a suitable polyether based polyol include polyoxyalkylene based polyols such as (di) ethylene glycol based polyether polyol, (di)propylene glycol based polyether polyol, (di)glycerin based polyether polyol, trimethylolpropane based polyether polyol, pentaerythritol based polyether polyol, sugar based polyether polyol, sucrose based polyether polyol, dextrose based polyether polyol, sorbitol based polyether polyol, mono-(di,tri)ethanol amine based polyether polyol, ethylenediamine based polyether polyol, tolylenediamine based polyether polyol, bisphenol A based polyether polyol, obtainable by the addition reaction of ethylene oxide and/or propylene oxide, polymer polyols obtainable by dispersing polymer microparticles in the polyoxyalkylene based polyol, Mannich polyols, and the like, which each of these may be used singularly, or two or more can be mixed for use.

[0021]

The hydroxyl value of the polyol can be, for example from 10 to 1900 mg KOH/g; however, in view of retaining the properties as a rigid polyurethane foam, it is usually from 200 to 500 mg KOH/g and preferebly from 220 to 500 mg KOH/g. More preferably, said polyol has a hydroxyl value of >300 mg KOH/g, especially preferably > 320 mg KOH/g or > 350 mg KOH/g, even more preferably >300 mg KOH/g and <500 mg KOH/g, >320 mg KOHg and <500 mg KOH/g or >350 mg KOHg and <500 mg KOHg. A hydroxyl value is the value measured in accordance with JIS K1557-1.

[0022]

The number of functional groups of the polyol component is usually from 2 to 8, preferably from 2 to 6, more preferably from 2 to 4, and more preferably from 2 to 3, in view of viscosity at the time of handling and imparting physical properties to the polyurethane foam.

[0023]

<Polyisocyanate>

As for the polyisocyanate, it is possible to use those usually used in the manufacture of polyurethane resins. Examples of such polyisocyanate include aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, and modifications thereof (e.g. modifications which have an urethane group, a carbodiimide group, an allophanate group, an urea group, a biuret group, an isocyanurate group, or an oxazolidone group), and a mixture of two or more of these.

[0024]

The aromatic polyisocyanate includes phenylene diisocyanate, tolylene diisocyanate (TDI), polymeric TDI (also called crude TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (also called crude MDI or polymeric MDI), xylylene diisocyanate (XDI), naphthylene diisocyanate, polyaryl polyisocyanate (PAPI), and the like. According to a preferred embodiment, the polyisocyanate consists of at least one of MDI, polymeric MDI, prepolymers or modifications of MDI, prepolymers or modifications of polymeric MDI, and mixtures thereof. According to a further preferred embodiment, the polyisocyanate does not comprise l,4-bis(isocyanatomethyl)cyclohexane.

[0025]

The aliphatic polyisocyanate includes, for example, an aliphatic diisocyanate having 2 to 18 carbons. A particular example includes hexamethylene diisocyanate (HMDI), and the like.

[0026]

The alicyclic polyisocyanate includes, for example, an alicyclic diisocyanate having 4 to 16 carbons. Particular examples include isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (dicyclohexylmethane diisocyanate, etc.), hydrogenated tolylene diisocyanate, norbornane diisocyanate, and the like.

[0027]

Amongst the polyisocyanates, the aromatic polyisocyanate, for example, polymethylene polyphenylene polyisocyanate is preferred, in view of imparting intensity to the polyurethane foam and improving heat resistance.

[0028]

< Silane coupling agent>

The composition for manufacturing a polyurethane foam of the present invention comprises a silane coupling agent as an essential component. According to the present invention, by using a silane coupling agent having a functional group capable of interacting with either one or both of the above-described polyol and polyisocyanate, which are the raw materials of the polyurethane foam, the adhesiveness of the polyurethane foam obtained to the adherend is improved. In the present invention, an interaction may either be a chemical interaction or a physical interaction, encompassing the idea of, for example, the case where a functional group of the silane coupling agent is chemically reacted to either one or both of the polyol and the polyisocyanate to form a chemical bond and the case where the silane coupling agent forms a physical bond with either one or both of the polyol and the polyisocyanate via Van der Waals' forces.

[0029] As a silane coupling agent, those which have a silyl group having a hydrolyzable group and a functional group capable of interacting with either one or both of the polyol and the polyisocyanate may be suitably used. A silyl group, reacted with fluid, forms a silanol group and strongly interacts with an inorganic material such as metal, or forms a chemical bond through reaction. As a result, the polyurethane foam can be firmly adhered to the adherend formed of an inorganic material such as metal.

[0030]

The silane coupling agent which can be suitably used in the present invention includes a compound represented by the following formula (1).

[0031]

[Formula 1]

(ROn

( 1 )

X— R ₂ Si Y ₍ 3-n ₎ wherein

Ri represents a monovalent organic group,

R2 represents a divalent organic group,

X represents a functional group capable of interacting with either one or both of the polyol or polyisocyanate,

Y each independently represents a hydrolyzable group, and

n represents an integer from 0 to 2.

[0032]

The monovalent organic group represented by Ri includes an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, and the like.

[0033]

Examples of the alkyl group include one having 1 to 10 carbons and preferably one having 1 to 5 carbons. The alkyl group may be chained, cyclic, or a combination thereof. Particular examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, a neopentyl group, 1-methylbutyl group, 2- methylbutyl group, a hexyl group, an isohexyl group, and the like.

[0034]

Examples of the alkenyl group include one having 2 to 10 carbons and preferably one having 2 to 5 carbons. The alkenyl group has at least one carbon-carbon double bond. The alkenyl group may be chained, cyclic, or a combination thereof. Particular examples of the alkenyl group include a vinyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, cyclopropenyl, and the like. [0035]

Examples of the alkynyl group include one having 2 to 10 carbons and preferably one having 2 to 5 carbons. The alkynyl group has at least one carbon-carbon triple bond. The alkynyl group may be chained, cyclic, or a combination thereof. Particular examples of the alkynyl group include a propynyl group, a butynyl group, a pentynyl group, a hexynyl group, a heptynyl group, cyclobutynyl group, and the like.

[0036]

An example of the aryl group includes a monocyclic or polycyclic (for example, bicyclic or tricyclic) aromatic carbon hydrogen ring group. Particular examples of the aryl group include a phenyl group, a naphthyl group, and the like.

[0037]

An example of the aralkyl group includes one having 7 to 15 carbons. Particular examples of the aralkyl group include a benzyl group, a diphenyl methyl group, naphtylmethyl group, and the like.

[0038]

Amongst those described above, Ri is preferably an alkyl group.

[0039]

The divalent organic group represented by R includes, for example, an alkylene group, an alkenylene group, alkynylene group, and the like, and is preferably alkylene group. Here, the divalent organic group represented by R may contain one or two or more of hetero atoms in a chain. Examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, and the like.

[0040]

An alkylene group means a divalent functional group generated by removing one hydrogen atom from an alkyl group. The explanation on the alkyl group is the same with what has been given in the above description.

[0041]

An alkenylene group means a divalent functional group generated by removing one hydrogen atom from an alkenyl group. The explanation on the alkenyl group is the same with what has been given in the above description.

[0042]

An alkynylene group means a divalent functional group generated by removing one hydrogen atom from an alkynyl group. The explanation on the alkynyl group is the same with what has been given in the above description.

[0043]

An example of the functional group represented by X includes an organic group containing at least one hetero atom selected from a nitrogen atom, an oxygen atom, and a sulfur atom, and is preferably an organic group having 1 to 10 carbons in total. More specifically, the functional group represented by X is preferably an epoxy group, a hydroxyl group, an amino group, an ureido group, an isocyanate group, or a mercapto group, and more preferably, an epoxy group, an amino group, or an isocyanate group. It is unexpected fact that the adhesiveness to the adherend of the polyurethane foam usable as a heat insulation material may be significantly improved when a silane coupling agent having such functional groups are used.

[0044]

The total number of carbons of the silane coupling agent having an epoxy group is, for example, 2 to 30, preferably 2 to 20, and more preferably 2 to 15. Examples of the silane coupling agent having an epoxy group include silane-containing organic compounds such as 2-(3,4- epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyl methyldimethoxy silane, 3- glycidoxypropyl trimethoxy silane, 3-glycidoxypropyl methyldiethoxysilane, 3-glycidoxypropyl triethoxysilane, and the like, and is preferably 3-glycidoxypropyl trimethoxysilane, 3- glycidoxypropyl triethoxysilane.

[0045]

The total number of carbons of the silane coupling agent having an amino group is, for example, 2 to 30, preferably 2 to 20, and more preferably 2 to 15. Examples of the silane coupling agent having an amino group include N-2(aminoethyl)-3-aminopropylmethyldimethoxy silane, N- 2(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- aminopropyltriethoxysilane, 3-triethoxysilyl-N-(l, 3 -dimethyl -butylidene) propylamine, N-phenyl- 3-aminopropyltrimethoxysilane, N-vinylbenzyl-2-aminoethyl-3-aminopropyltrimethoxysilane, and the like, and is preferably 3-aminopropyltriethoxysilane.

[0046]

The total number of carbons of the silane coupling agent having an ureido group is, for example, 2 to 30, preferably 2 to 20, and more preferably 2 to 10. An example of the silane coupling agent having an ureido group includes 3-ureidopropyltrialkoxysilane, and the like.

[0047]

The total number of carbons of the silane coupling agent having a mercapto group is, for example, 2 to 30, preferably 2 to 20, and more preferably 2 to 15. Examples of the silane coupling agent having a mercapto group include 3-mercaptopropylmethyldimethoxysilane, 3- mercaptopropyltrimethoxysilane.

[0048]

The hydrolyzable group represented by Y includes an alkyloxy group, an alkenyloxy group, an alkynyloxy group, and the like, and is preferably an alkyloxy group in view of the ease of hydrolysis. The explanation on the alkyl group, alkenyl group, and alkynyl group is the same with what has been given in the above description.

[0049] n denotes an integer from 0 to 2, preferably 0.

[0050]

The total number of carbons of the silane coupling agent having an isocyanate group is, for example, 3 to 30, preferably 3 to 20, and more preferably 3 to 15. Examples of the silane coupling agent having an isocyanate group include silane -containing organic compounds such as 3- isocyanatepropyltriethoxysilane, 3-isocyanatepropyltrimethoxy- silane, and is preferably 3- isocyanatepropyltriethoxysilane.

[0051]

The molecular weight of the silane coupling agent is not particularly limited, examples being from 85 to 1,000, preferably from 100 to 1,000, more preferably from 100 to 750, and even more preferably from 150 to 750.

[0052]

The content of the silane coupling agent is, for example, from 0.001 to 10 % by weight, preferably from 0.001 to 5 % by weight, more preferably from 0.001 to 2.5 % by weight, and even more preferably from 0.001 to 1 % by weight, based on the total amount of the composition for manufacturing a polyurethane foam.

[0053]

According to one embodiment of the present invention, the composition for manufacturing a polyurethane foam preferably comprises a foaming agent.

[0054]

According to one embodiment of the present invention, the foaming agent includes water, air, carbon dioxide, and (liquefied) gas such as nitrogen, carbon hydride, hydrochlorofluorocarbon, hydrofluorocarbon, and the like, and preferably includes water, cyclopentane, hydrochlorofluoroolefin, or hydrofluoroolefin, and the like, and more preferably includes water, cyclopentane, chlorotrifluoro propene or hexafluoro-2-butene, and even more preferably includes water, cyclopentane, trans-l-chloro-3,3,3-trifluoropropene or cis-1, 1, 1, 4, 4, 4-hexafluoro-2- butene.

[0055]

The content of the foaming agent is, for example, from 1 to 30 % by weight, preferably from 1 to 25 % by weight, and more preferably from 1 to 22 % by weight, based on the total amount of the composition for manufacturing a polyurethane foam.

[0056]

According to one embodiment of the present invention, preferably the foaming agent comprises water. In view of imparting physical properties to the polyurethane foam and lowering of the density, the water content is, for example, from 0.1 to 10 % by weight, preferably from 0.5 to 5 % by the weight, based on the total amount of the composition.

[0057] According to one embodiment of the present invention, the composition for manufacturing a polyurethane foam may further comprise a catalyst for manufacturing polyurethanes or a foam stabilizer, if needed.

[0058]

A known catalyst can be used as for the catalyst for manufacturing polyurethanes, as long as the object of the present invention is not disturbed, and amongst them, preference is made to the use of a basic nitrogen-containing organic catalyst. The basic nitrogen-containing organic catalysts include organic amine based catalysts such as 2-(2-dimethylaminoethoxy) ethanol, 2-[2-(2- dimethylaminoethoxy) ethoxy] ethanol, N-(2- dimethylaminoethyl)-N- methylethanol amine, N-[2- (2-dimethylaminoethoxy)ethyl]-N- methylethanol amine, and N,N,N', N"-tetramethyl-N"- isopropanol-diethylenetriamine, 1 ,4-diazabicyclo [2.2.2] octane, 2-methyl- 1 ,4-diazabicyclo [2.2.2] octane, N-methyl morpholine, N-ethyl morpholine, N-(2-dimethylaminoethyl) morpholine, dimorpholino diethylether, N,N,N',N'- tetramethylethylene diamine, N,N,N',N'-tetramethyl propylene diamine, N,N,N',N'-tetramethyl-l,6-hexanediamine, N,N'-dimethylpiperazine, N,N',N'- trimethylaminoethyl piperazine, tris (3-dimethylaminopropyl) amine, bis(3- dimethylaminopropyljamine, N,N-dimethylcyclohexylamine, N,N-dimethylbenzyl amine, 1,8- diazabicyclo[5.4.0]undecene-7, N,N',N"-tris(3- dimethylaminopropyl) hexahydro-s-triazine, 6- dimethylamino-l-hexanol, 5-dimethylamino-3-methyl-l-pentanol, dimethylethanolamine, dimethylisopropanolamine, N-(3- dimethylaminopropyl)-N-methylamino ethanol, N,N-dimethyl- N,N'-bis(2-hydroxypropyl)-l,3-propanediamine, N,N-bis(3- dimethylaminopropyljisopropanolamine, 1-methylimidazole, l-isobutyl-2-methylimidazole, 1,2- dimethylimidazole, derivatives thereof, and salts of those with acids such as carboxylic acid and carbonic acid, which each may be used singularly, or two or more can be mixed for use.

[0059]

As long as the object of the invention is not disturbed, organotin compounds such as dibutyltin dilaurate, di(2-ethylhexyl)tin dilaurate, and di(2-ethylhexanoic acid) tin, organometahic catalysts represented by di(2-ethylhexanoic acid) lead, di(2-ethylhexanoic acid)bismuth, and isocyanuration catalysts, potassium salts such as such as potassium acetate, 2- ethylhexanoic acid potassium, and quarternary ammonium salts may be used.

[0060]

The content of the catalyst for manufacturing polyurethanes is, for example, from 0.01 to 5 % by weight, preferably from 0.01 to 3 % by weight, and more preferably from 0.1 to 2.5 % by weight, based on the total amount of the composition.

[0061]

According to one embodiment of the present invention, the composition for manufacturing a polyurethane foam may comprise a foam stabilizer in view of controlling the form of a cell of the polyurethane foam. As the foam stabilizer, a known foam stabilizer used for the polyurethane foam can be used without limitation, examples including silicone based foam stabilizers such as a polyoxyalkylene-poly dimethyl siloxane copolymer, polydialkylsiloxane, and polyoxyalkylene polyol modified dimethylpolysiloxane, and anionic surfactants such as fatty acid salt, sulfate ester salt, phosphate ester salt, and sulfonate salt, which each of these may be used singularly, or two or more can be mixed for use. Amongst these, polyoxyalkylene- polydimethylsiloxane copolymer is preferred in view of strong foam stabilizing ability and dimensional stability.

[0062]

The content of the foam stabilizer is, for example, from 0.01 to 5 % by weight, preferably from 0.01 to 3 % by weight, and more preferably from 0.1 to 2.5 % by weight, based on the total amount of the composition.

[0063]

The composition for manufacturing a polyurethane foam may also comprise a flame retardant if needed. The flame retardant includes halogen based flame retardants such as tricresyl phosphate, tris(2- chloroethyl)phosphate, tris(2-chloroisopropyl)phosphate, tris(l,3- dichloropropyl) phosphate, tris(2,3-dibromopropyl)phosphate, which each of these may be used singularly, or two or more can be mixed for use. Amongst these, tris(2-chloroisopropyl)phosphate is preferred in view of stability over time and economical efficiency.

[0064]

The content of the flame retardant is, for example, from 1 to 60 % by weight, preferably from 1 to 30 % by weight, and more preferably from 1 to 15 % by weight, based on the total amount of the composition for manufacturing a polyurethane foam, in view of imparting flame retardancy to the polyurethane foam and retaining the properties as the polyurethane foam.

[0065]

In view of controlling the volume change of the polyurethane foam due to the temperature change, the composition for manufacturing a polyurethane foam may comprise a swelling agent. The swelling agent includes perlite, expanded perlite, glass, phonolite, calcium silicate, fumed silica, precipitated silica, silica gel, foamed polyurethane, polysaccharide, expanded vermiculite, a clay mineral, a fumed metal oxide, zeolite, diatomaceous earth, and the like.

[0066]

When the swelling agent is comprised, the swelling agent may be subjected to surface treatment by a coupling agent in order to improve dispersibility. The usable coupling agent is not particularly limited, and may be a conventionally known coupling agent. The usable coupling agent is, for example, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and the like. These coupling agents are used in view of dispersion stability of the swelling agent in the polyurethane foam. Thus, the purpose and embodiment of use of these coupling agents are different from those of the silane coupling agent of the present invention which is used in view of improving adhesiveness between the polyurethane foam and the adherend.

[0067]

Apart from those described above, an auxiliary agent other than the above-described swelling agent can be used as necessary in the manufacture of a polyurethane foam. As the auxiliary agent, those which are generally used in the manufacture of a polyurethane foam may be used. Apart from the catalyst, foaming agent, flame retardant, and foam stabilizer as mentioned above, the auxiliary agent includes a compatibilizer, a crosslinking agent, a stabilizer, a pigment, a filler, a viscosity-reducing agent, and the like. These auxiliary agents can be used as long as the object of the present invention is not disturbed.

[0068]

According to one embodiment of the present invention, the composition for manufacturing polyurethane foam can be used in order to attach the polyurethane foam to an adherend composed of various materials. A suitable example of the adherend includes an inorganic material such as metal, and the polyurethane foam can be applied to the adherend especially consisted of aluminum and an alloy thereof, stainless steel and an alloy thereof, iron and an alloy thereof, and copper and an alloy thereof. The shape of the adherend is not particularly limited, and preference is made to a face material. Optionally, a coating may be applied to the surface to which the composition is attached, as long as the adhesion with the polyurethane foam is not disturbed. The coating includes organic polymeric coating agents such as a polyester resin.

[0069]

According to one embodiment of the present invention, the isocyanate index when manufacturing the composition for manufacturing a polyurethane foam is usually from 80 to 350, preferably from 80 to 300, more preferably from 80 to 150. Herein, the isocyanate index is a numerical value obtained by multiplying 100 to the value obtained by dividing the total number of isocyanate groups in the polyisocyanate by the total number of the active hydrogens that is reactive with the isocyanate groups. That is to say, when the number of active hydrogens that is reactive with the isocyanate groups and the number of the isocyanate groups in the polyisocyanate are stoichiometrically equal, the isocyanate index is 100. In addition, in the case where water is used as part or all of a foaming agent, the isocyanate index is calculated in taking the amount and the number of the active hydrogens of water into account.

[0070]

< Polyurethane foam>

According to one embodiment of the present invention, there is provided a polyurethane foam formed from the composition for manufacturing a polyurethane foam. According to a preferable embodiment, the polyurethane foam is a rigid polyurethane foam.

[0071]

Preferably, the polyurethane foam usually have an adhesion strength (also called "tension shear adhesion strength") from 110 to 400 N/cm ² , preferably from 110 to 300 N/cm ² , and more preferably from 110 to 250 N/cm ² . More specifically, the adhesion strength to a stainless steel material is preferably from 120 to 350 N/cm ² , preferably from 120 to 300 N/cm ² , and more preferably from 120 to 250 N/cm ² . The adhesion strength to the aluminum material optionally coated is preferably from 110 to 300 N/cm ² , preferably from 110 to 250 N/cm ² , and more preferably from 110 to 220 N/cm ² . The adhesion strength can be measured in accordance with JIS K 6850.

[0072]

The density of the polyurethane foam may be set up suitably depending on use, and for example, may have a density from about 45 to 60 kg/m ³ . The density of the polyurethane foam can be obtained by measuring the weight of any polyurethane foam and dividing the value by its volume.

[0073]

The closed cell proportion of the polyurethane foam may be set up suitably, without particular limitation, to 90 % or more for example. The closed cell proportion can be measured based on the method as prescribed in ASTM D 2856.

[0074]

The compression strength of the polyurethane foam of the present invention can be suitably adjusted depending on the density. The compression strength of the polyurethane foam measured in conformity with JIS K 7220 is, for example, preferably 300 KPa or more when the density is 60 kg/m ³ .

[0075]

The polyurethane foam obtainable by using the composition for manufacturing a polyurethane foam of the present invention can be suitably used as for example, a heat insulation material for a construction material, a cold storage warehouse, a bathtub, a piping, and the like, a material for preventing dew formation for a single house, an apartment, an industrial piping, and the like, and a lightweight core material to be filled inside a construction material part such as a bay window and a sash in order to retain the shape of a product.

[0076]

According to a preferred embodiment of the present invention, there is provided a heat insulation material or a construction material comprising the polyurethane foam. According to another mode of the present invention, use of the polyurethane foam in the manufacture of the heat insulation material or the construction material is provided. According to another embodiment of the present invention, use of the polyurethane foam of the present invention as the heat insulation material or the construction material is provided.

[0077]

The polyurethane foam of the present invention can also be used when manufacturing an on-site construction type heat insulation material and a material for preventing dew formation by a spray method, and a construction material of a panel, a board, and the like in the factory line. Therefore, according to one embodiment of the present invention, the polyurethane foam is a spray rigid urethane foam for heat insulation in buildings as prescribed in JIS 9526 (2015).

[0078]

< Method for manufacturing polyurethane foam>

A polyurethane foam can be manufactured using the above-mentioned composition for manufacturing a polyurethane foam. Specifically, a polyol, a polyisocyanate, and a silane coupling agent are mixed, and the reaction between the polyol and the polyisocyanate allows to form a polyurethane foam, and also at the time of the reaction between the polyol and the polyisocyanate, the functional group of the silane coupling agent interacts with either one or both of the polyol and the polyisocyanate, and as a result, the adhesiveness between the polyurethane foam as obtained and the adherend is improved.

[0079]

Therefore, according to one embodiment of the present invention, there is provided a method for manufacturing a polyurethane foam comprising the step of mixing the polyol and the polyisocyanate and the silane coupling agent which has a functional group capable of interacting with either one or both of the polyol or the polyisocyanate.

[0080]

The method for manufacturing the polyurethane foam of the present invention may be carried out by using two components, a component comprising the polyol and a component comprising the polyisocyanate, in view of storage stability. In such case, the silane coupling agent may be comprised in either one or both of the component comprising the polyol and the component comprising the polyisocyanate. According to a preferred embodiment, the polyurethane foam can be manufactured by mixing the component comprising the polyol and the silane coupling agent with the component comprising the polyisocyanate, or mixing the component comprising the polyol with the component comprising the polyisocyanate and the silane coupling agent, or mixing the component comprising the polyol and the silane coupling agent with the component comprising the polyisocyanate and the silane coupling agent.

[0081]

Also, according to another preferred embodiment, the polyurethane foam may be manufactured by mixing three components, a component comprising the polyol, a component comprising the polyisocyanate, and a component comprising the silane coupling agent.

[0082]

In the above-described method, each of the component comprising the polyol, the component comprising the polyisocyanate, the component comprising the silane coupling agent, the component comprising the polyol and the silane coupling agent, and the component comprising the polyisocyanate and the silane coupling agent may independently comprise an auxiliary agent such as a catalyst for manufacturing polyurethanes, a foaming agent, a foam stabilizer, a flame retardant, a compatibilizer, a crosslinking agent, a stabilizer, a pigment, a filler, and a viscosity- reducing agent.

[0083]

In the method for manufacturing the polyurethane foam, the above-mentioned mixing process is not particularly limited, and each of the component may be added and mixed simultaneously or individually; however, when the component comprising the silane coupling agent is added after mixing the component comprising the polyol and the component comprising the polyisocyanate, the reaction between the silane coupling agent can be unsatisfactory due to excessive progress of urethane reaction.

[0084]

A more specific embodiment of the mixing step is, for example, a method by mixing and stirring while injecting each of the above-described component in a forming mold or a mixing method by spraying and colliding each component by means of a spraying machine, and the like.

[0085]

The above-mentioned mixing step can be performed at a temperature from about 15 to 35 °C for example.

[0086]

In the manufacturing method of the present invention, the mixture of the polyol, the polyisocyanate, and the silane coupling agent (a composition for manufacturing a polyurethane foam) may contain a solid content. However, in view of effective formation of the foam, liquid or semi-solid form is preferred. The gel time of the above-mentioned mixture is preferably short, in view of rapid adherence to the adherend and formation of the polyurethane foam. Here, the gel time refers to the time (seconds) from the time when the mixing is started, which is regarded as zero second, to the time when the obtained mixture started to generate a string when touched with a stick-form solid. In the present invention, the gel time is specified by the average value of the time measured by visual judgment as the examples mentioned below.

[0087]

The above-mentioned gel time is preferably from 5 to 200 seconds, more preferably from 8 to 150 seconds, and even more preferably from 15 to 120 seconds. EXAMPLES

[0088]

Hereinafter, the present invention will be explained in more details by the aid of the Examples without being limited to those Examples. Unless specifically stated otherwise, the unit and the measuring method according to the present invention is in accordance with the prescription of Japanese Industrial Standards (JIS). “Part(s)” and“%” mean“part(s) by weight” and“% by weight”, respectively.

[0089]

<Test for evaluating adhesion strength >

According to the raw materials and the test procedures explained below, the polyol- containing component (1st component) and the polyisocyanate (2nd component) were mixed in a given blending ratio to give mixed liquids from which test samples of Test Group A and Test Groups 1-1 to 7-2 were obtained to be measured for adhesion strength.

[0090]

<Raw materials >

Raw materials of the test samples of Test Group A and Test Groups 1-1 to 7-2 are as shown in the component information in the following Tables 1 and 2. In accordance with Tables 1 and 2, each raw materials for the polyol-containing component are selected from polyols A to C, a foam stabilizer, a silane coupling agent, catalysts A and B, foaming agents A to D. Further, in Tables 1 and 2, among the foaming agents, only the weight of foaming agent A (water) is included in the weight of the polyol-containing component which is the basis of the caliculation of the mixing weight ratio (polyol-containing component/polyisocianate) so as to calculate isocianate index. The hydroxyl value in the polyol is the value measured in accordance with JIS K 1557-1 (2007).

[0091]

The details of the silane coupling agents as shown in Tables 1 and 2 are as follows.

[0092]

3-glycidoxypropyltrimethoxysilane: a compound represented by the following formula (2).

[Formula 2]

o

(CH30)3SiC3H ₆ 0CH ₂ CH-CH2 ⁽²⁾

[0093]

3-glycidoxypropyltriethoxysilane: a compound represented by the following formula (3).

[Formula 3] [0094]

3-isocyanatepropyltriethoxysilane: a compound represented by the following formula (4).

[Formula 4]

[0095]

3-aminopropyltriethoxysilane: a compound represented by the following formula (5).

[Formula 5]

(C2H50)3SiC3HgNH2 (5)

[0096]

The details of the foaming agents shown in Tables 1 and 2 are as follows.

Foaming agent A - water

Foaming agent B - cyclopentane

Foaming agent C - HCFO-1233zd: trans- 1 -chloro-3,3,3-tnfluoiopio pene ((E)CHC1=CHCF ₃ , molecular weight 130)

Foaming agent D - HFO-1336mzz (Z) : cis- 1 , 1 , 1 ,4,4,4-hcxafluoro-2-butcnc((Z)CF;CH=CHF;, molecular weight 164)

[0097]

< Testing procedure: Evaluation of adhesiveness>

According to the following procedures of 1) to 8), the adhesive strength of the test samples of Test Group A and Test Groups 1-1 to 7-2 were measured. Further details for measuring the adhesive strength shall be in accordance with JIS K6850:1999.

1) Each component of the polyol-containing component other than a foaming agent in a given amount was added to a disposable beaker (500 cc).

2) To the disposable beaker of 1), a foaming agent was added until it reached the given amount and mixed at a given temperature (20 ± 0.5 °C).

3) At a given temperature (20 ± 0.5 °C), isocyanate in a given amount was added to the disposable beaker (500 cc) of 2) to obtain a mixed solution.

4) The mixed solution of 3) was added in a homomixer (from PRIMIX Corporation), and stirred for 8 seconds at about 4000 rpm to obtain a reaction mixture. Here, the time until the mixed solution started to generate a string was determined as the gel time (seconds) when the mixed solution in the disposable beaker was touched with disposable chopsticks.

5) The reaction mixture of 4) was poured into an openable and closable mold (its inner dimension is 400 mm in length, 300 mm in width, and 50 mm in thickness) heated to 40 °C beforehand, the top and the bottom sides of which were arranged with a face material for measuring adhesiveness (size - 50 mm in length, and 50 mm in width; a pore having a diameter of 1 mm was provided at the end beforehand).

6) The above-described mold was opened after 30 minutes had passed, and the composition adhered to the face material was removed.

7) After 12 hours or more had passed, the circumference of the face material was cut off with a cutter knife, and the face material to which the composition was adhered and a jig (50 mm in length and 50 mm in width) were adhered using a two-part epoxy adhesive. The test specimen to which the jig was attached was left to cure for 12 hours or more, a screw suited for the screw hole arranged on the jig was installed, and then the screw was installed in a tensile testing machine (Autograph AG-lONXplus, from Shimadzu Corporation) to apply a load at a constant speed of 10 mm/min, whereby the maximum load until the test specimen was destroyed was determined as the adhesion strength.

[0098]

The results were as shown in Tables 1 and 2.

As it is apparent from Tables 1 and 2, Test Groups 1-1 to 7-2 in which the silane coupling agents were used in the cases where the polyurethane foams were formed on the face materials made of aluminum or stainless steel, they showed higher adhesiveness compared to Test Group A in which no silane coupling agent was used.

099] able 1]

100] able 2]