WO2021028256A1

WO2021028256A1 - A composition for manufacturing a polyurethane foam

Info

Publication number: WO2021028256A1
Application number: PCT/EP2020/071851
Authority: WO
Inventors: Tohru Matsumura; Yuudai Kashiwamoto
Original assignee: Covestro Intellectual Property Gmbh & Co. Kg
Priority date: 2019-08-09
Filing date: 2020-08-04
Publication date: 2021-02-18
Also published as: CN114174370A

Abstract

[Problem] Provided is a composition for manufacturing a polyurethane foam from which a polyurethane foam is obtainable having excellent adhesiveness to an adherend, particularly inorganic materials such as metal and olefinic resin materials such as polyethylene and polypropylene. [Solving means] To provide a composition for manufacturing a polyurethane foam, comprising a polyol and a polyisocyanate, wherein the polyol comprises at least two polyol compounds and one of said at least two polyol compounds is polycaprolactone, wherein the composition does not comprise 1-1dichloro-1-fluoroethane.

Description

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 containing a polyol with a component mainly containing 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]

Patent Document 1 reports 1.1-dichloro-l-fluoroethane as an alternative for a conventionally used foaming agent. However, when 1.1-dichloro-l-fluoroethane is used, there is a problem that dimension stability at lower temperatures and compression strength are significantly deteriorated.

[0005]

With respect to the above-described problem of adhesiveness, Patent Document 2 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 3 proposes 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 4 further proposes the use of a specific microcapsule as the foaming agent in order to improve the adhesiveness to the adherend.

[Patent Documents]

[0006]

[Patent Document 1] JPH3-86735A [Patent Document 2] JP2009-215386A [Patent Document 3] JP2018-80328A [Patent Document 4] JP2008-133395A

SUMMARY OF THE INVENTION [Problems to be Solved by the Invention]

[0007]

Although the methods proposed in the above-described Patent Documents 2 to 4 improve adherence to specific adherends, adherence to adherends comprising olefinic resin materials such as polyethylene or polypropylene is still low; and there is no polyurethane foams attained that has excellent adherence to such materials.

[0008]

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 or olefinic resin materials such as polyethylene and polypropylene.

[Means for Solving the Problem]

[0009]

According to the present invention, the followings are provided:

(1) A composition for manufacturing a polyurethane foam, comprising a polyol and a polyisocyanate, wherein said polyol comprises at least two polyol compounds and one of said at least two polyol compounds is polycaprolactone, wherein said composition does not comprise 1,1-dicholoro-l-fluoroethane.

(2) The composition according to (1), wherein said polycaprolactone has a functional number from 2 to 8.

(3) The composition according to (1) or (2), wherein said polycaprolactone has a number average molecular weight from 115 to 1500.

(4) The composition according to any one of (1) to (3), wherein said polycaprolactone is comprised from 0.1 to 30 % by weight based on the total amount of said polyols.

(5) A polyurethane foam formed from the composition according to any one of (1) to (4). (6) A heat insulation material comprising said polyurethane foam according to (5).

[Effect of the Invention]

[0010]

According to the present invention, there can be provided a composition for manufacturing a polyurethane foam from which a polyurethane foam is obtained having excellent adhesiveness to an adherend, particularly inorganic materials such as metal or olefinic resin materials such as polyethylene and polypropylene.

[Mode for Carrying out the Invention]

[0011]

The composition for manufacturing a polyurethane foam of the present invention comprises a polyol and a polyisocyanate as essential components. Hereinafter is explained each component which constitutes the composition for manufacturing a polyurethane foam of the present invention.

[0012]

The polyol comprised in the composition for manufacturing a polyurethane foam of the present invention comprises at least two polyol compounds, wherein one of the at least two polyol compounds is polycaprolactone. In the present invention, the incorporation of polycaprolactone in addition to a polyol conventionally used for the polyurethane foam as a polyol allows to obtain a polyurethane foam with excellent adhesiveness to adherends consisted of olefinic resin materials, let alone inorganic materials such as metal. The reason is unknown; however, it is assumed that when the polyols and the polyisocyanate are subjected to curing reaction, the polycaprolactone accelerates the crosslinking formation to retain the strength of the foam and the caprolactone skeleton is incorporated into the polyurethane chain, whereby compatibility with the polyolefin resin, let alone the inorganic material such as metal is improved.

[0013]

There is no particular limitation to the polyol other than the polycaprolactone (hereinafter can be referred to as a “non-polycaprolactone polyol”), 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 polyether polyols, polymer polyols, and Mannich polyols are preferable in view of hydrolysis resistance of the polyol itself and stability in reaction with the polyisocyanate component.

[0014] 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.

[0015]

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.

[0016]

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.

[0017]

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

[0018]

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.

[0019]

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. [0020]

The hydroxyl value of the above-described non-polycaprolactone 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 preferably from 220 to 500 mg KOH/g. A hydroxyl value is the value measured in accordance with JIS K1557-1.

[0021]

In view of viscosity when handling and imparting physicality to the polyurethane foam, the functional number of the non-polycaprolactone polyol is generally from 2 to 8, preferably from 2 to 6, more preferably from 2 to 4, and further more preferably from 2 to 3.

[0022]

The polycaprolactone which can be used is not particularly limited, as long as it is one obtained from ring-opening polymerization reaction of e-caprolactone on a polyhydric alcohol, and it is possible to use various polycaprolactone oligomers or polycaprolactone polymers having different types or different levels of polymerization of the polyhydric alcohols.

[0023]

The polyhydric alcohol used for obtaining a polycaprolactone is not particularly limited, as long as it is divalent to octavalent alcohols having 2 to 10 carbons. Specific examples thereof include, without being limited to those listed herein, aliphatic glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1 ,2- butanediol, 1,3-butanediol, 1 ,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 3-methyl-l,5- pentanediol, neopentyl glycol, 2-methyl-l, 3-propanediol, 2-methyl -2 -propyl-1, 3-propanediol, 2- butyl-2 -ethyl-1, 3-propanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-l,3- pentanediol, 2-ethyl- 1, 3 -hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,8-octanediol, 2-methyl-l, 8- octanediol, and 1,9-nonanediol; alicyclic glycols such as bishydroxymethyl cyclohexane; glycols having an aromatic ring such as xylene glycol, bishydroxy ethoxy benzene; triols such as glycerin, trimethylol propane, trimethylol ethane, 1,2,6-hexane triol, and 1,2,4-butane triol; tetraols such as pentaerythritol; and sugar polyols with a functional number of 8 such as lactose. Preferred amongst these are aliphatic glycols and especially preferred are aliphatic glycols having 6 carbons or less. One of these can be used singularly or two or more of these in combination.

[0024]

The number average molecular weight of the polycaprolactone is, in view of viscosity when handling and imparting physicalities to the polyurethane foam, preferably from 115 to 1500 and more preferably from 250 to 1300. The number average molecular weight is, as used herein, means the number average molecular weight converted into standard polystyrene measured in accordance with gel permeation chromatography method (hereinafter abbreviated as “GPC method”). [0025]

The hydroxyl value of polycaprolactone can be within the range from 50 to 1000 mgKOH/g, and in view of retaining the properties as a rigid polyurethane foam, preferred range is from 70 to 700 mgKOH/g and more preferred from 80 to 550 mgKOH/g.

[0026]

In view of viscosity when handling and imparting physicalities to the polyurethane foam, the functional number of the polycaprolactone (the number of hydroxyl group in one molecule) is normally from 2 to 8, preferably from 2 to 4, and more preferably from 2 to 3.

[0027]

The polycaprolactone as described above can have a desirable molecular amount and a functional number by appropriate adjustment of the kind of polyhydric alcohol used as a raw material and its feed amount, the feed amount of e-caprolactone against them, the kind of catalyst for the ring-opening reaction and the kind of ring-opening reaction catalyst and its feed amount. [0028]

The content of polycaprolactone in the composition for manufacturing a polyurethane foam is, in view of adherence and mechanical strength, etc., from 0.1 to 30 % by weight, preferably from 0.1 to 20 % by weight, and more preferably from 5 to 15 % by weight, based on the total amount of polyol.

[0029]

The amount of polycaprolactone added in the composition for manufacturing a polyurethane foam is, for example, from 0.001 to 15 % by weight, preferably from 0.1 to 10 % by weight, and more preferably from 0.1 to 8 % by weight, based on the total amount of the composition for manufacturing a polyurethane foam.

[0030]

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.

[0031]

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, poly aryl polyisocyanate (PAPI), and the like.

[0032]

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

[0033]

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.

[0034]

In view of imparting strength to the polyurethane foam and improving heat resistance, preferred among the polyisocyanates are aromatic polyisocyanates such as polymethylene polyphenylene polyisocyanate.

[0035]

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

[0036]

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 (HCFO-1233zd) or cis-1, 1, 1, 4, 4, 4- hexafluoro-2-butene (HFO-1336mzz (Z)). It is clear that this also means, that the composition for manufacturing a polyurethane foam may comprise a foaming agent comprising water and a physical foaming agent, preferably wherein the physical foaming agent is selected from the group consisting of cyclopentane, hydrochlorofluoroolefins, hydrofluoroolefins and mixtures thereof, more preferably wherein the physical foaming agent is selected from the group consisting of cyclopentane, chlorotrifluoro propene, hexafluoro-2 -butene and mixtures thereof, most preferably wherein the physical foaming agent is selected from the group consisting of cyclopentane, trans-1- chloro-3,3,3-trifluoropropene (HCFO-1233zd), cis-1, 1,1, 4, 4, 4-hexafluoro-2 -butene (HFO-1336mzz (Z)) and mixtures thereof.

[0037]

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.

[0038]

According to one embodiment of the present invention, the foaming agent preferably 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.

[0039]

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

[0040]

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- di methyl am inopiopyl jamine, 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- dimethylaminopropyl)isopropanolamine, 1-methylimidazole, l-isobutyl-2-methylimidazole, 1,2- dimethylimidazole, derivatives thereof, and salts from these with acids such as carboxylic acid and carbonic acid, which each may be used singularly, or two or more can be mixed for use.

[0041]

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; organometallic catalysts represented by di(2-ethylhexanoic acid) lead, di(2-ethylhexanoic acid)bismuth; and potassium salts such as such as potassium acetate, 2-ethylhexanoic acid potassium, and isocyanuration catalysts such as quarternary ammonium salts may be used.

[0042]

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.

[0043] 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-polydimethyl 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.

[0044]

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.

[0045]

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.

[0046]

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.

[0047]

Apart from those described above, an auxiliary 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 to the extent as long as the object of the present invention is not disturbed.

[0048]

According to one embodiment of the present invention, the composition for manufacturing a 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 inorganic materials such as metal and organic materials such as a resin, and the polyurethane foam can be applied to the adherend especially consisted of metal materials such as aluminum and an alloy thereof, stainless steel and an alloy thereof, iron and an alloy thereof, and copper and an alloy thereof; and olefinic resin materials such as polyethylene and polypropylene. 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.

[0049]

The above-described composition for manufacturing a polyurethane foam may be a composition consisted of two components which are a polyol-containing component and a polyisocyanate -containing component. In such case, the polycaprolactone is preferably contained in the polyol-containing component. According to a preferred embodiment of the present invention, the composition for manufacturing a polyurethane foam is obtainable by mixing a polyol- containing component and a polyisocyanate -containing component.

[0050]

In addition, either one or both of the polyol-containing component and the polyisocyanate -containing component can comprise at least one of the above -described auxiliary agent, or else an auxiliary agent-containing component may be prepared apart from the polyol- containing component and the polyisocyanate -containing component.

[0051]

The polyol-containing component preferably contains polyol in an amount of 80 % by weight or more, more preferably of 90 % by weight or more, and further preferably of 95 % by weight or more, in view of reaction stability of the polyol itself with the polyisocyanate.

[0052]

The proportion of polyisocyanate contained in the polyisocyanate-containing component is preferably normally adjusted such that the polyisocyanate index will be from 20 to 300, preferably from 70 to 140, and more preferably from 90 to 120. As used herein, the “isocyanate index” is the value obtained by dividing the total number of the isocyanate groups in the polyisocyanate by the total number of active hydrogen which may react with the isocyanate group and multiplying by 100. That is, when the number of active hydrogens which may react with the isocyanate group is stoichiometrically equal to the isocyanate groups in the polyisocyanate, the isocyanate index will be 100. When water is used as part or the whole foaming agent, the amount of water and its number of active hydrogens shall be taken into consideration in calculation of the isocyanate index. [0053]

The weight proportion of the polyol-containing component and the polyisocyanate- containing component (polyol-containing component / polyisocyanate-containing component) is generally from 100/170 to 100/85, preferably from 100/150 to 100/90, and further preferably from 100/140 to 100/95.

[0054]

< 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.

[0055]

Adhesion strength (also called "tension shear adhesion strength") of the polyurethane foam vary depending on the type of adherend, and is usually from 40 to 400 N/cm², preferably from 40 to 380 N/cm², and more preferably from 40 to 350 N/cm². More specifically, the adhesion strength to a stainless steel material is preferably from 110 to 400 N/cm², more preferably from 110 to 380 N/cm², and further preferably from 140 to 340 N/cm². The adhesion strength to the aluminum material optionally coated is preferably from 100 to 300 N/cm², more preferably from 110 to 280 N/cm², and further preferably from 110 to 260 N/cm². The adhesion strength to the polypropylene material is preferably from 40 to 170 N/cm², more preferably from 45 to 150 N/cm², and further preferably from 45 to 120 N/cm². The adhesion strength to the polyethylene material is preferably from 40 to 130 N/cm², more preferably from 40 to 120 N/cm², and further preferably from 40 to 110 N/cm².The adhesion strength can be measured in accordance with JIS K 6850. [0056]

The density of the polyurethane foam may be set up suitably depending on purpose, and for example, may have a density from about 45 to 60 kg/m³. The density of the polyurethane foam can be obtained by measuring the weight of any polyurethane foam and dividing the value by its volume.

[0057]

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.

[0058]

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/m³.

[0059] 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.

[0060]

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.

[0061]

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 A 9526 (2015).

[0062]

< Method for manufacturing polyurethane foam>

A polyurethane foam can be manufactured using the above-mentioned composition for manufacturing a polyurethane foam. Specifically, a polyol and a polyisocyanate constituting the composition for manufacturing a polyurethane foam are mixed and by reaction between the two, a polyurethane foam can be formed. That is, according to another embodiment of the present invention, there is provided a method for manufacturing a polyurethane foam, comprising the step of mixing a polyol and a polyisocyanate, wherein the polyol comprises at least two polyol compounds, wherein one of the at least two polyol compounds is polycaprolactone.

[0063]

The aspect of mixing the polyol and the polyisocyanate may be performed, without particular limitation, by mixing the polyol-containing component and the polyisocyanate- containing component as mentioned above, or else may be by mixing the the polyol-containing, the polyisocyanate -containing component, and the an auxiliary agent-containing component. Further, a polycaprolactone and a non-polycaprolactone polyol may be simultaneously reacted with a polyisocyanate, or a polycaprolactone may be reacted with a polyisocyanate beforehand to prepare a prepolymer and carry out reaction of the prepolymer and a non-polycaprolactone polyol.

[0064] 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 to a container and mixed simultaneously or individually.

[0065] 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. [0066]

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

[0067]

In the manufacturing method of the present invention, the mixture of the polyol and the polyisocyanate (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 mixing is started, which is regarded as zero second, to the time when the obtained mixture started to generate a thread 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.

[0068]

The above-mentioned gel time is preferably from 50 to 200 seconds, more preferably from 90 to 150 seconds, and even more preferably from 90 to 120 seconds.

EXAMPLES

[0069]

Hereinafter, the present invention will be explained in more details by the aid of the Examples without being limited thereby. 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.

[0070]

According to the raw materials and the test procedures explained below, a polyol- containing component and a polyisocyanate were mixed in a given blending ratio to give mixed liquids from which test samples of Test Example A and Test Groups 1 to 16 were obtained to be measured for adhesion strength.

[0071]

Raw materials of the test samples of Test Example A and Test Groups 1 to 16 are as shown in the component information in the following Tables 1 and 2. As shown in Tables 1 and 2, the raw materials used for the polyol-containing components in each test group were selected from polyols A to L, a foam stabilizer, catalysts A or 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 calculation of the mixing weight ratio (polyol-containing component/polyisocyanate) so as to calculate isocyanate index. The hydroxyl value in the polyol is the value measured in accordance with JIS K 1557-1 (2007).

[0072]

< Testing procedure: Evaluation of adhesiveness>

According to the following procedures of 1) to 8), the adhesive strength of the test samples of Test Example A and Test Groups 1 to 16 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 (inner dimension: 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).

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.

[0073]

The results were as shown in Tables 1 and 2.

According to Tables 1 and 2, as a result of adding the composition on a face material, the polyurethane foams of Test Groups 1 to 16 comprising the polycaprolactone showed high adhesiveness against all of the face materials (aluminum, stainless, polystyrene, and polyethylene) as compared with Test Example A in which no polycaprolactone was used. Specifically, polyurethane foams produced with a foaming agent comprising water and a physical foaming agent showed highest adhesiveness against all of the face materials.

[Table 1]

Table 2]

Claims

1. A composition for manufacturing a polyurethane foam, comprising a polyol and a polyisocyanate, wherein said polyol comprises at least two polyol compounds and one of said at least two polyol compounds is polycaprolactone, wherein said composition does not comprise 1,1-dicholoro-l-fluoroethane, wherein said composition comprises a foaming agent comprising water and a physical foaming agent.

2. The composition according to claim 1, wherein said polycaprolactone has a functional number from 2 to 8.

3. The composition according to claim 1 or 2, wherein said polycaprolactone has a number average molecular weight from 115 to 1500.

4. The composition according to any one of claims 1 to 3, wherein said polycaprolactone is comprised from 0.1 to 30 % by weight based on the total amount of the polyols.

5. A polyurethane foam formed from the composition according to any one of claims 1 to 4.

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