JP2010031064A - Manufacturing method for hard polyurethane foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a hard polyurethane foam capable of obtaining a hard polyurethane foam having sufficient dimension stability and sufficient heat insulation performance, being excellent in storage stability when a mixture of a used polymer dispersion polyol and a hard polyurethane foam polyol is stored, and capable of stably manufacturing the hard polyurethane foam. <P>SOLUTION: In the method for manufacturing the hard polyurethane foam by reacting a polyol component (Z) with a polyisocyanate component in the presence of a foaming agent, a bubble regulating agent and a catalyst, an average hydroxyl group value of the polyol component (Z) is 200-800 mgKOH/g. The manufacturing method for the hard polyurethane foam is characterized in that a polymer fine particle contains a polymer dispersion polyol (A) dispersed in the polyol by polymerizing a monomer having a polymerizable unsaturated group containing a fluorine-containing monomer in the polyol (X). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a rigid polyurethane foam.

A rigid foamed synthetic resin produced by reacting a polyol component and a polyisocyanate component in the presence of a foaming agent or the like (for example, rigid polyurethane foam or the like; hereinafter sometimes referred to as “rigid foam”) has closed cells. It is widely used as a heat insulating material.
As the foaming agent used for the rigid foam, a low-boiling point hydrofluorocarbon compound or hydrocarbon compound is mainly used.

In rigid foams typified by boards and the like, further reduction in density of foams is desired in order to reduce costs and reduce weight by reducing the amount of raw materials used. However, as the density of the foam is reduced, there is a problem that the foam strength is reduced and the rigid foam is likely to shrink.
In addition, in the case of foaming agents, considering the burden on the environment, reducing low-boiling hydrofluorocarbon compounds and increasing water, or considering flammability, reducing hydrocarbon compounds and increasing water In addition, a technique of using only water without using a low-boiling point hydrofluorocarbon compound or hydrocarbon compound has been studied.
However, when the density of the foam is reduced by water foaming, such as by using a hydrofluorocarbon compound or hydrocarbon compound in combination with water to reduce the density of the foam or by foaming only with water, the foam is prominent. The dimensional stability of the foam deteriorates.

As measures for the dimensional stability of the foam, usually, the foam density is increased to increase the foam strength, or the foam bubbles are made to be open cells.
However, measures to increase the density of the foam increase the cost because the amount of raw material used increases. In addition, the measures for making the foam cells into continuous cells improve the dimensional stability of the foam, but cannot provide sufficient heat insulation performance.
That is, in a rigid foam, when water is frequently used as a foaming agent or foamed with only water, a foam having good foam dimensional stability and sufficient heat insulating performance is desired.

  Conventionally, a method using a fluorine-containing compound such as polytetrafluoroethylene (PTFE) has been proposed as a known technique for preventing shrinkage of rigid polyurethane foam and improving dimensional stability (see Patent Documents 1 and 2). . According to the methods described in Patent Documents 1 and 2, by adding PTFE having a small particle size, dimensional stability is improved by opening fine pores in the foam, and good heat insulating performance is also obtained.

Moreover, the method of mix | blending polymer-dispersed polyol with a polyol component is proposed (refer patent document 3, 4).
The “polymer-dispersed polyol” is a polyol in which polymer fine particles are dispersed in a polyol such as polyether polyol or polyester polyol.
The polymer-dispersed polyol has been conventionally used to improve the dimensional stability of flexible foam or semi-rigid foam.

The following method is known as a typical example of a method for producing a polymer-dispersed polyol. That is, in a saturated polyol having no polymerizable unsaturated bond, in some cases, under the condition that an unsaturated polyol having a polymerizable unsaturated bond is also present, the monomer having a polymerizable unsaturated group is polymerized, and then This is a method for removing unreacted components. As the saturated polyol or the unsaturated polyol, various polyether polyols and polyester polyols are known.
European Patent Application No. 0224945 JP-T 8-503720 JP 57-25313 A JP-A-11-302340

However, for example, the fluorine-containing compounds used in the methods described in Patent Documents 1 and 2 generally have poor solubility in organic substances. Therefore, a fluorine-containing compound such as PTFE is added to the polyol compound for storage. In such a case, it was found that the storage stability was insufficient such as separation of the fluorine-containing compound and the polyol compound, and the rigid polyurethane foam could not be produced stably.
In addition, the polymer-dispersed polyol used in the methods described in Patent Documents 3 and 4 has insufficient storage stability when mixed with a polyol for a rigid polyurethane foam having a small molecular weight, so that the rigid polyurethane foam can be stably produced. In addition, it was found that it is difficult to achieve both heat insulation performance when used as a rigid polyurethane foam.

Therefore, the present invention provides a rigid polyurethane foam having good dimensional stability and sufficient thermal insulation performance, and also provides storage stability when a mixture of the polymer-dispersed polyol and polyol for rigid polyurethane foam is stored. Provided is a method for producing a rigid polyurethane foam, which is excellent and therefore can stably produce a rigid polyurethane foam.
The “storage stability” in the present invention means a characteristic capable of maintaining the uniformity of the mixture when the mixture of the polymer-dispersed polyol and the polyol for rigid polyurethane foam is stored. When the storage stability is poor, it is difficult to obtain a rigid polyurethane foam of stable quality, such as polymer fine particles are separated from the polyol compound, or the polymer-dispersed polyol migrates in the mixture and the composition becomes non-uniform. Become.

The present invention provides a process for producing a rigid polyurethane foam by reacting a polyol component (Z) with a polyisocyanate component in the presence of a foaming agent, a foam stabilizer and a catalyst, wherein the polyol component (Z) comprises an average hydroxyl group This is a method for producing a rigid polyurethane foam, characterized in that it has a value of 200 to 800 mg KOH / g and contains the following polymer-dispersed polyol (A).
However, the polymer-dispersed polyol (A) is a polymer in which polymer fine particles are dispersed in a polyol by polymerizing a monomer having a polymerizable unsaturated group in the polyol (X). The polyol (X) is a polyether. The monomer containing a polyol and having a polymerizable unsaturated group includes a fluorine-containing acrylate or a fluorine-containing methacrylate.

  In the method for producing a rigid polyurethane foam of the present invention, the fluorine-containing acrylate or the fluorine-containing methacrylate is preferably a monomer represented by the following formula (1).

ただし、式（１）中、Ｒ^ｆは炭素数１〜１８のポリフルオロアルキル基であり、Ｒは水素原子またはメチル基であり、Ｚは２価の連結基である。

However, in Formula (1), ^Rf is a C1-C18 polyfluoroalkyl group, R is a hydrogen atom or a methyl group, and Z is a bivalent coupling group.

Moreover, in the manufacturing method of the rigid polyurethane foam of this invention, it is preferable that the monomer which has the said polymerizable unsaturated group contains acrylonitrile further.
In the method for producing a rigid polyurethane foam of the present invention, the polyether polyol preferably has an oxyethylene group content of 10% by mass or more.
In the method for producing a rigid polyurethane foam of the present invention, the polyether polyol preferably has a hydroxyl value of 84 mgKOH / g or less.
In the method for producing a rigid polyurethane foam of the present invention, the polyether polyol is preferably a polyoxyalkylene polyol obtained by addition polymerization of propylene oxide and ethylene oxide to a polyhydric alcohol.
Moreover, in the manufacturing method of the rigid polyurethane foam of this invention, it is preferable that the ratio of the monomer represented by the said Formula (1) in all the monomers which have the said polymerizable unsaturated group is 30-100 mass%.
Moreover, in the manufacturing method of the rigid polyurethane foam of this invention, the ratio of the said polymer dispersion polyol (A) in the said polyol component (Z) is 0.8 mass% or more, and in the said polyol component (Z) The ratio of the polymer fine particles is preferably 0.1% by mass or more.
In the method for producing a rigid polyurethane foam according to the present invention, it is preferable to use water alone or at least one selected from a hydrofluorocarbon compound and a hydrocarbon compound as the foaming agent.

  According to the method for producing a rigid polyurethane foam of the present invention, a rigid polyurethane foam having good dimensional stability and sufficient heat insulating performance can be obtained. Moreover, since it is excellent in the storage stability at the time of storing the mixture of the polymer dispersion polyol to be used and the polyol for rigid polyurethane foam, a rigid polyurethane foam can be manufactured stably.

≪Method of manufacturing rigid polyurethane foam≫
The method for producing a rigid polyurethane foam of the present invention is a method for producing a rigid polyurethane foam by reacting a polyol component (Z) and a polyisocyanate component in the presence of a foaming agent, a foam stabilizer and a catalyst.
Details of each component will be described below.

[Polyol component (Z)]
The polyol component (Z) in the present invention contains the specific polymer-dispersed polyol (A).
As a component other than the polymer-dispersed polyol (A) of the polyol component (Z), for example, a polyol (for example, a polyether polyol, a polyester polyol, or a polyol used for producing a normal rigid polyurethane foam such as a hydrocarbon-based polymer having a hydroxyl group at the terminal ( In the present specification, "polyol for rigid polyurethane foam") can be used.
The polyol for rigid polyurethane foam preferably has an average functional group number of 2 to 8.
The number of functional groups means the number of functional groups (hydroxyl groups) of the polyol that reacts with the polyisocyanate component. For example, in the case of polyether polyol, the number of active hydrogens of the initiator used in producing the polyether polyol. be equivalent to.
Specific examples of the polyol for rigid polyurethane foam include the same ones as exemplified for the polyol (X) described in the polymer-dispersed polyol (A) described later.

The average hydroxyl value of the polyol component (Z) is 200 to 800 mgKOH / g, preferably 250 to 600 mgKOH / g, and more preferably 300 to 500 mgKOH / g. It is preferable that the average hydroxyl value is 200 mgKOH / g or more because the strength of the resulting rigid polyurethane foam is easily obtained. When the average hydroxyl value is 800 mgKOH / g or less, the resulting rigid polyurethane foam is difficult to be brittle, which is preferable.
In this invention, an average hydroxyl value means the average value of the hydroxyl value of all the polyol compounds which comprise a polyol component (Z).

(Polymer-dispersed polyol (A))
The polymer-dispersed polyol (A) in the present invention is a polymer fine particle dispersed in a polyol by polymerizing a monomer having a polymerizable unsaturated group in the polyol (X). The polyol (X) The monomer containing an ether polyol and having the polymerizable unsaturated group contains a fluorine-containing acrylate or a fluorine-containing methacrylate.
When the polyol component (Z) contains the polymer-dispersed polyol (A), a rigid polyurethane foam having good dimensional stability and sufficient heat insulating performance can be obtained. Further, the polymer-dispersed polyol (A) has high compatibility with the polyol for rigid polyurethane foam and is excellent in storage stability when a mixture thereof is stored, so that the rigid polyurethane foam can be stably produced.
In the present invention, “in the polyol (X)” may be in the polyol (X) alone, and the solvent exemplified in the description of the “method for producing the polymer-dispersed polyol (A)” described below, It may be in a mixture with polyol (X).

・ Polyol (X)
In the polymer-dispersed polyol (A), as the polyol (X), for example, a polyether polyol, a polyester polyol, or a hydrocarbon polymer having a hydroxyl group at the terminal can be used.
However, in the present invention, the polyol (X) contains at least a polyether polyol. By including the polyether polyol, the compatibility between the polyol for rigid polyurethane foam and the polymer-dispersed polyol (A) is increased, and the storage stability is improved.

As the polyether polyol, for example, those obtained by addition polymerization of cyclic ethers such as alkylene oxides with initiators such as polyhydroxy compounds such as polyhydric alcohols and polyhydric phenols and amines can be used.
Specific examples of the initiator include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,4-butanediol, 1,6-hexanediol, water , Polyglycerols such as glycerin, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, diglycerin, tetramethylolcyclohexane, methylglucoside, sorbitol, mannitol, dulcitol, sucrose, triethanolamine; bisphenol A, Polyhydric phenol such as phenol-formaldehyde initial condensate; piperazine, aniline, monoethanolamine, diethanolamine, isopropanolamine, aminoethylethanol Examples include amino compounds such as min, ammonia, aminomethylpiperazine, aminoethylpiperazine, ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, xylylenediamine, diphenylmethanediamine, diethylenetriamine, triethylenetetramine, and their cyclic ether adducts. It is done.
The said initiator can be used individually by 1 type or in combination of 2 or more types.

As the cyclic ether, for example, a 3- to 6-membered cyclic ether compound having one oxygen atom in the ring can be used.
Specific examples of cyclic ethers include ethylene oxide, propylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, trimethylethylene oxide, tetramethylethylene oxide, butadiene monooxide, styrene oxide, α-methylstyrene oxide, epichlorohydrin. , Epifluorohydrin, epibromohydrin, glycidol, butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether, 2-chloroethyl glycidyl ether, o-chlorophenyl glycidyl ether, ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, 3-membered cyclic esters such as cyclohexene oxide, dihydronaphthalene oxide, vinylcyclohexene monoxide Compounds having an ether group (monoepoxide); oxetane, tetrahydrofuran, a compound having a 4-6 membered cyclic ether group such as tetrahydrofuran and tetrahydropyran.
Among these, compounds having a 3-membered cyclic ether group (monoepoxide) are preferable, alkylene oxides having 2 to 4 carbon atoms are more preferable, and ethylene oxide, propylene oxide, isobutylene oxide, 1-butene oxide, and 2-butene oxide are preferable. Further preferred are ethylene oxide and propylene oxide.
The said cyclic ether can be used individually by 1 type or in combination of 2 or more types.
When using in combination of 2 or more types of cyclic ether, as a cyclic ether, a C2-C4 alkylene oxide is preferable and the combination of a propylene oxide and ethylene oxide is the most preferable. At that time, the initiator can be subjected to addition polymerization of a mixture of two or more kinds of cyclic ethers, or two or more kinds of cyclic ethers can be addition-polymerized sequentially.

In the polyether polyol, the oxyethylene group content in the polyether polyol is preferably 10% by mass or more, more preferably 30% by mass or more, further preferably 40% by mass or more, and 55 The content is particularly preferably at least mass%, and most preferably at least 60 mass%. On the other hand, the oxyethylene group content is preferably 90% by mass or less.
When the oxyethylene group content is 10% by mass or more, a polymer-dispersed polyol (A) in which polymer fine particles are stably dispersed is easily obtained, and storage stability is improved. In particular, when the oxyethylene group content is 60% by mass or more, the storage stability for a longer period (for example, about one month) becomes better.
In the present invention, “oxyethylene group content” means the proportion of oxyethylene groups in the polyol compound.

The polyether polyol preferably has a hydroxyl value of 84 mgKOH / g or less, more preferably 67 mgKOH / g or less, and particularly preferably 60 mgKOH / g or less. The lower limit of the hydroxyl value is preferably 5 mgKOH / g or more, more preferably 8 mgKOH / g or more, particularly preferably 20 mgKOH / g or more, and most preferably 30 mgKOH / g. . When the hydroxyl value is 84 mgKOH / g or less, the storage stability can be improved while the viscosity is low, and when the hydroxyl value is 5 mgKOH / g or more, the storage stability is improved.
When the hydroxyl value of the polyether polyol is 84 mgKOH / g or less, the oxyethylene group content in the polyether polyol is substantially equal to the oxyethylene group content relative to the entire OA groups in the polyether polyol.

In addition, the polyether polyol is preferably obtained by addition polymerization of ethylene oxide or ethylene oxide and another cyclic ether using a polyhydric alcohol as an initiator.
As the polyhydric alcohol, for example, glycerin, trimethylolpropane, and 1,2,6-hexanetriol are preferable.
As other cyclic ethers, for example, propylene oxide, isobutylene oxide, 1-butene oxide and 2-butene oxide are preferable, and propylene oxide is particularly preferable.
Among these, the polyether polyol is preferably a polyoxyalkylene polyol obtained by addition polymerization of propylene oxide and ethylene oxide to a polyhydric alcohol. When the polyoxyalkylene polyol is used, the polymer-dispersed polyol (A) in which polymer fine particles are more stably dispersed is more easily obtained, and the storage stability is further improved.

  As the polyester polyol, for example, a polyester polyol obtained by polycondensation of a polyhydric alcohol and a polyvalent carboxylic acid can be used. Other examples include polycondensation of hydroxycarboxylic acids, polymerization of cyclic esters (lactones), polyaddition of cyclic ethers to polycarboxylic anhydrides, polyester polyols obtained by transesterification of waste polyethylene terephthalate, and the like.

  As the hydrocarbon-based polymer having a hydroxyl group at the terminal, for example, polytetramethylene glycol (PTMG) or polybutadiene polyol can be used.

In the present invention, the polyol (X) contains at least the polyether polyol, and in addition to the polyether polyol, a polyester polyol, a hydrocarbon polymer having a hydroxyl group at the terminal, or the like may be used in combination.
The content of the polyether polyol is preferably 50% by mass or more in the polyol (X), more preferably 80% by mass or more, and most preferably 100% by mass. When the content is 50% by mass or more, most preferably 100% by mass, a polymer-dispersed polyol (A) in which polymer fine particles are stably dispersed is easily obtained, and storage stability is improved.

-Monomer having a polymerizable unsaturated group The monomer having a polymerizable unsaturated group in the present invention includes a fluorine-containing acrylate or a fluorine-containing methacrylate (hereinafter sometimes referred to as "fluorine-containing monomer").
By including the fluorine-containing monomer, the dispersion stability of the polymer fine particles in the polyol (X) is improved. Further, the compatibility between the polymer-dispersed polyol (A) to be used and the polyol for the rigid polyurethane foam is increased, the storage stability is improved, and the rigid polyurethane foam is easily produced stably. Furthermore, when a rigid polyurethane foam is used, the dimensional stability is improved, and at the same time, good thermal insulation performance is easily obtained.

In the present invention, the preferred fluorine-containing monomer includes a monomer represented by the formula (1) because it has high compatibility with the polyol (X).
In said formula (1), ^Rf is a C1-C18 polyfluoroalkyl group. In ^Rf , the number of carbon atoms is 1 to 18, preferably 1 to 10, and more preferably 3 to 8.
R ^f is preferably such that the proportion of fluorine atoms in the alkyl group (the proportion of the number of hydrogen atoms in the alkyl group substituted by fluorine atoms) is 80% or more, and all the hydrogen atoms are fluorine atoms. It is particularly preferred that it is substituted. When the number of carbon atoms is 18 or less, the foam stability is good when foaming in the production of rigid polyurethane foam, which is preferable.
R is a hydrogen atom or a methyl group. That is, the monomer represented by the formula (1) becomes an acrylate when R is a hydrogen atom, and becomes a methacrylate when R is a methyl group.
Z is a divalent linking group, and examples thereof include an alkylene group and an arylene group, and an alkylene group is preferable. The alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, particularly preferably an alkylene group having 1 to 5 carbon atoms, and may be linear or branched.
Specific examples of the monomer represented by the formula (1) are shown below.

The said fluorine-containing monomer can be used individually by 1 type or in combination of 2 or more types.
The amount of the fluorine-containing monomer used is preferably 10 to 100% by mass, and more preferably 30 to 100% by mass, based on the total monomer having the polymerizable unsaturated group.
In particular, the ratio of the monomer represented by the formula (1) in the total monomer having a polymerizable unsaturated group is preferably 30 to 100% by mass, and more preferably 40 to 100% by mass. 50% by mass is most preferable.
When the amount used is 10% by mass or more, particularly 30% by mass or more, the storage stability is further improved. In particular, better heat insulation performance can be obtained when a rigid polyurethane foam is used.
From the above, the polymer fine particles in the present invention may be a polymer composed solely of a fluorine-containing monomer, or may be a copolymer of a fluorine-containing monomer and another monomer having a polymerizable unsaturated group. Especially, since the dispersion stability of the polymer fine particle in the said polyol (X) is favorable, it is preferable that a polymer fine particle is a copolymer.

In the present invention, examples of the monomer having a polymerizable unsaturated group that may be used in combination with the fluorine-containing monomer include cyano group-containing monomers such as acrylonitrile, methacrylonitrile, 2,4-dicyanobutene-1, styrene, α- Styrene monomers such as methyl styrene and halogenated styrene; acrylic monomers such as acrylic acid, methacrylic acid or their alkyl esters, acrylamide and methacrylamide; vinyl ester monomers such as vinyl acetate and vinyl propionate; isoprene, butadiene and others Diene-based monomers; unsaturated fatty acid esters such as maleic acid diester and itaconic acid diester; vinyl halides such as vinyl chloride, vinyl bromide and vinyl fluoride; halo such as vinylidene chloride, vinylidene bromide and vinylidene fluoride Lanka vinylidene; methyl vinyl ether, ethyl vinyl ether, vinyl ether monomer such as isopropyl vinyl ether; or than those olefins, halogenated olefins, macromonomers, and the like.
The “macromonomer” refers to a low molecular weight polymer or oligomer having a radical polymerizable unsaturated group at one end.
Among these, acrylonitrile, vinyl acetate, and styrene are preferable, and acrylonitrile is particularly preferable because storage stability for a longer period (for example, about one month) is improved. Moreover, it is also preferable to use styrene because the foam breaking effect is high and the dimensional stability is good.
One or two or more monomers other than the fluorine-containing monomer can be used.

When the fluorine-containing monomer and acrylonitrile are used in combination, the mixing ratio of the fluorine-containing monomer and acrylonitrile is preferably 10:90 to 90:10, and preferably 30:70 to 70:30. Is more preferable. Within this range, long-term storage stability is improved. Moreover, especially when it is set as a rigid polyurethane foam, heat insulation performance improves.
When the fluorinated monomer and acrylonitrile are used in combination, and a polyether polyol having an oxyethylene group content of 60% by mass or more is used as the polyol (X), the storage stability is particularly excellent, and a rigid polyurethane foam is obtained. Sufficient thermal insulation performance can be obtained.

Furthermore, when using together the said fluorine-containing monomer, acrylonitrile, and styrene, it is preferable that the mixing ratio of the said fluorine-containing monomer and other monomers is 10: 90-90: 10 by mass ratio, 30: More preferably, it is 70-70: 30.
Further, the mixing ratio of acrylonitrile and styrene is preferably 0: 100 to 100: 0, more preferably 90:10 to 10:90, in terms of mass ratio.
When it is the mixing ratio, storage stability when a mixture of a polymer-dispersed polyol and a polyol for rigid polyurethane foam to be used is stored, and dimensional stability and heat insulation performance when a rigid polyurethane foam is obtained are improved. Those characteristics can be obtained in a well-balanced manner.

[Polyisocyanate component]
The polyisocyanate component in the present invention is not particularly limited. For example, aromatic, alicyclic and aliphatic polyisocyanates having two or more isocyanate groups; mixtures of two or more of the polyisocyanates; Examples thereof include modified polyisocyanates obtained by modification. Specific examples include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (common name: crude MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HMDI), and the like. Polyisocyanates or their prepolymer-modified products; isocyanurate-modified products, urea-modified products, carbodiimide-modified products, and the like. Of these, TDI, MDI, crude MDI or a modified product thereof is preferable.
A polyisocyanate component can be used individually by 1 type or in combination of 2 or more types.

[Foaming agent]
As the foaming agent in the present invention, water is mainly used. As a foaming agent other than water, for example, a hydrofluorocarbon compound, a hydrocarbon compound, or an inert gas can be used in combination.
Specific examples of the hydrofluorocarbon compound include 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1, 1,3,3-pentafluorobutane (HFC-365mfc), 1,1,2,2-tetrafluoroethyl difluoromethyl ether (HFE-236pc), 1,1,2,2-tetrafluoroethyl methyl ether (HFE) -254 pc), 1,1,1,2,2,3,3-heptafluoropropyl methyl ether (HFE-347mcc) and the like.
Specific examples of the hydrocarbon compound include butane, normal pentane, isopentane, cyclopentane, hexane, and cyclohexane.
Examples of the inert gas include air, nitrogen, carbon dioxide gas, and the like. Of these, carbon dioxide is preferable. The addition state of the inert gas may be any of a liquid state, a supercritical state, and a subcritical state.

A foaming agent can be used individually by 1 type or in combination of 2 or more types.
In the present invention, it is preferable to use water alone or at least one selected from hydrofluorocarbon compounds and hydrocarbon compounds and water as the blowing agent. Thereby, a foaming effect improves and it can aim at the weight reduction of a rigid polyurethane foam.

[Foam stabilizer]
There is no restriction | limiting in particular as a foam stabilizer in this invention, For example, a silicone type foam stabilizer is mentioned as a suitable thing. Among these, in order to provide the heat insulation performance of the rigid polyurethane foam, a silicone type foam stabilizer having a high foam regulating effect capable of reducing the cell diameter is particularly preferable.
A foam stabilizer can be used individually by 1 type or in combination of 2 or more types.

[catalyst]
The catalyst in the present invention is not particularly limited as long as it is a catalyst that promotes the urethanization reaction.
Examples of the catalyst for promoting the urethanization reaction include tertiary amines such as triethylenediamine, bis (2-dimethylaminoethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine; and dibutyltin dilaurate. An organometallic compound is mentioned.
Moreover, you may use together the catalyst which accelerates | stimulates the trimerization reaction of an isocyanate group, and carboxylic acid metal salts, such as potassium acetate and potassium 2-ethylhexanoate, etc. are mentioned.
When spray foaming is employed as a method for producing a rigid foam, it is preferable to use an organometallic catalyst such as lead 2-ethylhexanoate in order to complete the reaction in a short time.

[Other ingredients]
In the present invention, any compounding agent may be used as necessary.
Compounding agents include fillers such as calcium carbonate and barium sulfate; anti-aging agents such as antioxidants and UV absorbers; flame retardants, plasticizers, colorants, anti-fungal agents, foam breakers, dispersants, discoloration prevention Agents and the like.

<Method for producing rigid polyurethane foam>
The present invention is a method for producing a rigid polyurethane foam by reacting a polyol component (Z) and a polyisocyanate component in the presence of a foaming agent, a foam stabilizer and a catalyst.
In production, the polyol component (Z) is prepared in advance, and a mixture of the polyol component (Z) and a part or all of the components other than the polyisocyanate component (hereinafter referred to as a polyol system liquid) is prepared. Is preferred.
The blowing agent may be blended in advance in the polyol system liquid, or may be blended after mixing the polyisocyanate component in the polyol system liquid, and in particular, it is preferably blended in advance in the polyol system liquid. .

The polyol component (Z) can be prepared, for example, by mixing the polymer-dispersed polyol (A) and the polyol for rigid polyurethane foam.
The polymer-dispersed polyol (A) is produced by polymerizing a monomer having a polymerizable unsaturated group in the polyol (X) to produce a polymer-dispersed polyol in which polymer fine particles obtained by polymerizing the monomer are dispersed in the polyol. If it is a method, it will not specifically limit. For example, since the dispersion stability of the polymer fine particles in the polyol (X) is good, a monomer having a polymerizable unsaturated group is polymerized in the polyol (X) in the presence of a solvent as necessary to directly polymerize the polymer. A suitable method is a production method in which fine particles are precipitated to obtain a polymer-dispersed polyol.

Specific examples of the method for producing the polymer-dispersed polyol (A) include the following methods (a) and (b).
(1) A part of the polyol (X) is charged into the reactor, and while stirring, a mixture of the remaining polyol (X), a monomer having a polymerizable unsaturated group, a polymerization initiator and the like is gradually added to the reactor. A batch method in which polymerization is carried out by feeding to a catalyst.
(2) A mixture of polyol (X), a monomer having a polymerizable unsaturated group, a polymerization initiator, etc. is continuously fed into the reactor under stirring to conduct polymerization, and at the same time, the produced polymer-dispersed polyol is Continuous process that continuously discharges from the reactor.
In the present invention, any of the production methods (1) and (2) can be used.

  In the present invention, the amount of use of all the monomers having a polymerizable unsaturated group is not particularly limited, but it is preferable that the concentration of the polymer fine particles in the polymer-dispersed polyol (A) is 50% by mass or less. The amount is more preferably 1 to 50% by mass, particularly preferably 2 to 45% by mass, and most preferably 5 to 30% by mass. When the concentration of the polymer fine particles is 50% by mass or less, the polymer-dispersed polyol (A) in which the polymer fine particles are stably dispersed in the polyol (X) is further easily obtained, and the storage stability is further improved. Moreover, moderate viscosity is obtained and the liquid stability of the polymer-dispersed polyol (A) is improved.

In the method for producing the polymer-dispersed polyol (A), as the polymerization initiator, one that generates a free radical and initiates polymerization of a monomer having a polymerizable unsaturated group is usually used.
Specifically, for example, 2,2-azobis-isobutyronitrile (hereinafter abbreviated as “AIBN”), 2,2-azobis-2-methylbutyronitrile, 2,2-azobis-2,4- Examples thereof include dimethylvaleronitrile, benzoyl peroxide, diisopropyl peroxydicarbonate, acetyl peroxide, di-tert-butyl peroxide, persulfate and the like. Of these, AIBN and 2,2-azobis-2-methylbutyronitrile are preferable.
These polymerization initiators can be used singly or in combination of two or more.
The amount of the polymerization initiator used is a total of 100 masses of the polyol (X), all monomers having a polymerizable unsaturated group including a fluorine-containing monomer, and a stabilizer or grafting agent (described later) used as necessary. It is preferable that it is 0.01-10 mass parts with respect to a part.

Examples of the solvent include alcohols such as methanol, ethanol, isopropanol, butanol, cyclohexanol and benzyl alcohol; aliphatic hydrocarbons such as pentane, hexane, cyclohexane and hexene; aromatic hydrocarbons such as benzene, toluene and xylene; acetone Ketones such as methyl ethyl ketone and acetophenone; esters such as ethyl acetate and butyl acetate; ethers such as isopropyl ether, tetrahydrofuran, benzyl ethyl ether, acetal, anisole and methyl tert-butyl ether; chlorobenzene, chloroform, dichloroethane, 1, Halogenated hydrocarbons such as 1,2-trichlorotrifluoroethane; nitro compounds such as nitrobenzene; nitriles such as acetonitrile and benzonitrile; Trimethylamine, triethylamine, tributylamine, amines such as dimethylaniline; N, N- dimethylformamide, amides such as N- methyl pyrrolidone; dimethyl sulfoxide, sulfur compounds such as sulfolane.
The said solvent can be used individually by 1 type or in combination of 2 or more type.
In the production of the polymer-dispersed polyol (A), when a solvent is used, the mixing ratio of the solvent and the polyol (X) is preferably 0: 100 to 60:40, and 0: 100 to More preferably, it is 40:60. When the mixing ratio is within the range, aggregation of polymer particles is suppressed, and a polymer-dispersed polyol (A) in which polymer fine particles are stably dispersed is easily obtained.
After the polymerization of the monomer having a polymerizable unsaturated group is completed, the solvent is removed. The method for removing the solvent is usually performed by heating under reduced pressure. It can also be carried out under normal pressure heating or reduced pressure at room temperature. At this time, unreacted monomers are also removed together with the solvent.

  The polymerization reaction of the monomer having a polymerizable unsaturated group in the polyol (X) is carried out at a temperature equal to or higher than the decomposition temperature of the polymerization initiator, usually 80 to 160 ° C., preferably 90 to 150 ° C., It is particularly preferred to be carried out at ˜130 ° C.

In the present invention, a stabilizer or a grafting agent can be used to improve the dispersion stability of the polymer fine particles in the polymer-dispersed polyol (A).
Preferable examples of the stabilizer or grafting agent include compounds having an unsaturated bond in the molecule. Specifically, a high molecular weight polyol or monool obtained by reacting an alkylene oxide with an active hydrogen compound having an unsaturated bond-containing group such as a vinyl group, an allyl group, or an isopropyl group as an initiator; After reacting with an unsaturated carboxylic acid such as maleic anhydride, itaconic anhydride, maleic acid, fumaric acid, acrylic acid, methacrylic acid, or its anhydride, an alkylene oxide such as propylene oxide or ethylene oxide is added as necessary. High-molecular-weight polyols or monools obtained as above; reaction products of unsaturated alcohols such as 2-hydroxyethyl acrylate and butenediol with other polyols and polyisocyanates; unsaturated epoxy compounds such as allyl glycidyl ether and polyols And the like.
These stabilizers or grafting agents may have a hydroxyl group or may not have a hydroxyl group, but preferably have a hydroxyl group.
The stabilizer or grafting agent can be mixed and blended with the polyol (X), a monomer having a polymerizable unsaturated group, a polymerization initiator, and the like.

  After the completion of the polymerization reaction, the obtained polymer-dispersed polyol (A) may be used as it is as a raw material for the rigid polyurethane foam, and the obtained polymer-dispersed polyol (A) is subjected to reduced pressure treatment to remove unreacted monomers. It may be used later, and the latter is preferred.

In the preparation of the polyol component (Z), the mixing ratio of the polymer-dispersed polyol (A) and the polyol for rigid polyurethane foam is such that the ratio of the polymer-dispersed polyol (A) in the polyol component (Z) is 0.1% by mass or more. Preferably, it is 0.8% by mass or more, more preferably 1% by mass or more. On the other hand, the ratio of the polymer-dispersed polyol (A) is preferably 10% by mass or less, and more preferably 7% by mass or less.
The proportion of the polymer fine particles in the polyol component (Z) is preferably 0.005% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.3% by mass or more. preferable. On the other hand, the ratio of the polymer fine particles is preferably 5% by mass or less, and more preferably 1% by mass or less.
When the ratio of the polymer-dispersed polyol (A) and the polymer fine particles in the polyol component (Z) is at least the lower limit value, both the dimensional stability and the heat insulation performance are improved when a rigid polyurethane foam is obtained. On the other hand, storage stability improves that it is below an upper limit, and a rigid polyurethane foam can be manufactured stably. Moreover, an appropriate viscosity is easily obtained as the polyol component (Z), and the liquid stability is improved.

The amount of water used as the blowing agent is preferably 1 to 15 parts by mass, more preferably 2 to 13 parts by mass, and still more preferably 4 to 12 parts by mass with respect to 100 parts by mass of the polyol component (Z). If the usage-amount of water is 1 mass part or more, it is preferable at the point of weight reduction of the rigid polyurethane foam obtained. On the other hand, if the amount of water used is 15 parts by mass or less, it is preferable because the miscibility of water and the polyol component (Z) becomes better.
When using a thing other than water as a foaming agent, the usage-amount in the case of using a hydrofluorocarbon compound as a thing other than water is 1-50 mass parts with respect to 100 mass parts of polyol components (Z), and 20-20 are preferable. More preferred is 40 parts by weight.
1-40 mass parts is preferable with respect to 100 mass parts of polyol components (Z), and, as for the usage-amount in the case of using a hydrocarbon compound, 10-20 mass parts is more preferable.
1-100 mass parts is preferable with respect to 100 mass parts of polyol components (Z), and, as for the usage-amount in using an inert gas, 1-20 mass parts is more preferable.

Although the usage-amount of a foam stabilizer needs to be selected suitably, 0.1-10 mass parts is preferable with respect to 100 mass parts of polyol components (Z).
The amount of the catalyst used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polyol component (Z).

The use amount of the polyisocyanate component is preferably 50 to 300 in terms of isocyanate index (INDEX).
In addition, an isocyanate index (INDEX) shows the value represented by multiplying the ratio of the number of isocyanate groups to the total number of active hydrogens of the polyol component (Z) and other active hydrogen compounds by 100.
In a polyurethane formulation that mainly uses a urethanization catalyst as the catalyst, the amount of the polyisocyanate component used is preferably 50 to 140, more preferably 60 to 130, in terms of isocyanate index.
In addition, in a polyisocyanurate formulation (urethane-modified polyisocyanurate formulation) mainly using a catalyst that promotes a trimerization reaction of an isocyanate group as a catalyst, the use amount of the polyisocyanate component is preferably 120 to 300 in terms of isocyanate index, 150-250 is more preferable.

The method for producing a rigid polyurethane foam in the present invention can be applied to various molding methods.
Examples of the molding method include pouring, continuous production board, and spray foaming foam.
Injection is a method of injecting a rigid polyurethane foam raw material into a frame such as a mold and foaming. The continuous production board is a laminate in which a rigid polyurethane foam is sandwiched between two face materials, and is used as a heat insulating material for architectural purposes. The spray foaming foam is a construction in which a rigid polyurethane foam is sprayed and applied.
Among the above, the method for producing a rigid polyurethane foam according to the present invention can be suitably applied to the production of an injecting urethane foam, a continuous production board, a spray foam foam and the like.

  As described above, according to the method for producing a rigid polyurethane foam of the present invention, a rigid polyurethane foam having good dimensional stability and sufficient heat insulation performance can be obtained. Moreover, since it is excellent in the storage stability at the time of storing the mixture of the polymer dispersion polyol to be used and the polyol for rigid polyurethane foam, a rigid polyurethane foam can be manufactured stably.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by these examples.
In the following examples, the hydroxyl value was measured according to JIS K1557 (1970 edition). The viscosity was measured according to JIS K1557 (1970 edition). The concentration of polymer fine particles (solid content) was defined as the concentration of monomers having a polymerizable unsaturated group as the fine particle concentration (solid content).
The monomer reaction rate in the production of the polymer-dispersed polyol (Production Examples 1 to 8) was calculated from a calibration curve created by gas chromatography (manufactured by Shimadzu Corporation).

≪Evaluation of polymer-dispersed polyol≫
According to the blending ratio shown in Table 1, polymer-dispersed polyols F1 to F8 were produced by the following Production Examples 1 to 8.
Table 1 shows the blend composition at the time of production of the polymer-dispersed polyol, the hydroxyl value (mgKOH / g), the viscosity (mPa · s), and the concentration (solid content: mass%) of the polymer fine particles of the obtained polymer-dispersed polyols F1 to F8. Show.
In the compounding composition of Table 1, polyols D to G and the monomer having a polymerizable unsaturated group are “g”; the polymerization initiator is 100 parts by mass in total of polyols D to G and all monomers having a polymerizable unsaturated group Is the value of “parts by mass” relative to

(Raw materials used).
Polyether polyol Polyol D: Glycerol was used as an initiator, and a mixture of propylene oxide (PO) and ethylene oxide (EO) [PO / EO = 33/67 (mass ratio)] was added to the glycerin by polymerization. A polyoxyalkylene polyol having an oxyethylene group content of 65% by mass and a hydroxyl value of 50 mgKOH / g in polyol D.
Polyol E: Polyol E in which glycerin is used as an initiator, PO is added to the glycerin by PO so that PO / EO = 85.5 / 14.5 (mass ratio), and then EO is added. A polyoxyalkylene polyol having an oxyethylene group content of 14.2% by mass and a hydroxyl value of 34 mgKOH / g.

Polyol F: A polyoxyalkylene polyol having an oxyethylene group content of 0% by mass and a hydroxyl value of 760 mgKOH / g in polyol F, in which ethylenediamine is used as an initiator and PO is added to the ethylenediamine.
Polyol G: Polyoxyalkylene polyol having an oxyethylene group content of 0 mass% and a hydroxyl value of 650 mgKOH / g in polyol G, in which glycerin is used as an initiator and PO is added to the glycerin.

Fluorine-containing monomer Fluorine-containing monomer (f): A monomer (manufactured by Asahi Glass Co., Ltd.) represented by the following chemical formula (1-1) was used.

・ Monomers with other polymerizable unsaturated groups Acrylonitrile (manufactured by Pure Chemical).
Styrene (made by Gordo solvent).
Vinyl acetate (made by Pure Chemical).
Polymerization initiator 2,2-azobis-2-methylbutyronitrile (trade name: ABN-E, manufactured by Nippon Hydrazine; hereinafter abbreviated as “AMBN”).

<Production of polymer-dispersed polyol>
Production Example 1: Production of polymer-dispersed polyol F1 70 mass% of polyol D was charged into a 5 L pressure reaction tank and maintained at 120 ° C., while remaining 30 mass% of polyol D, acrylonitrile, fluorine-containing monomer (f) And a mixture of the polymerization initiator (AMBN) were fed over 2 hours with stirring, and stirring was continued for about 0.5 hours at the same temperature after the completion of all feeds. At that time, it was confirmed that the monomer reaction rate measured by the above method was 80% or more, and the reaction was terminated. Then, the polymer-dispersed polyol F1 was manufactured by removing the unreacted monomer by heating and degassing at 120 ° C. and 20 Pa for 8 hours. The results are shown in Table 1.

Production Example 2: Production of polymer-dispersed polyol F2 70 mass% of polyol D was charged into a 5 L pressure reaction tank and maintained at 120 ° C., while the remaining 30 mass% of polyol D, acrylonitrile, styrene, fluorine-containing monomer ( The mixture of f) and the polymerization initiator (AMBN) was fed over 1 hour with stirring, and stirring was continued at the same temperature for about 0.5 hours after the completion of all the feeds. At that time, it was confirmed that the monomer reaction rate measured by the above method was 80% or more, and the reaction was terminated. Then, the polymer-dispersed polyol F2 was manufactured by removing the unreacted monomer by heating under reduced pressure at 120 ° C. and 20 Pa for 6 hours. The results are shown in Table 1.

Production Examples 3 to 7: Production of polymer-dispersed polyols F3 to F7 Polymer-dispersed polyols F3 to F7 were produced in the same manner as in Production Example 1 except that the monomer having a polymerizable unsaturated group shown in Table 1 was used. The results are shown in Table 1.

Production Example 8: Production of polymer-dispersed polyol F8 After all of polyol D, polyol F, polyol G, acrylonitrile, vinyl acetate and polymerization initiator (AMBN) were charged into a 5 L pressure reactor, the temperature was increased while stirring. The reaction solution was allowed to react for 10 hours while maintaining the temperature at 80 ° C. At that time, it was confirmed that the monomer reaction rate measured by the above method was 80% or more, and the reaction was terminated. Then, the polymer-dispersed polyol F8 was manufactured by removing the unreacted monomer by heating under reduced pressure at 110 ° C. and 20 Pa for 2 hours. The results are shown in Table 1.

<Evaluation of storage stability>
According to the mixing ratios of Test Examples 1 to 8 shown in Table 2, the polymer-dispersed polyols F1 to F7 produced in Production Examples 1 to 7 and the following polytetrafluoroethylene (PTFE) powder were mixed with the following polyols A to C. An evaluation sample was prepared by adding each to the polyol.
And this evaluation sample was stored at 23 degreeC for 1 week, the external appearance (separation state) of the evaluation sample after storage was observed visually, and the storage stability (1 week) was evaluated by the following evaluation criteria.
Evaluation criteria ○: It was a uniform dispersion solution.
X: The polymer fine particles or PTFE powder and the polyol were separated.

(Raw materials used)
Polytetrafluoroethylene (PTFE) powder (trade name: polytetrafluoroethylene resin powder fluon L-173, manufactured by Asahi Glass Co., Ltd.).

Polyol for rigid polyurethane foam Polyol A: Tolylenediamine is used as an initiator, and EO, PO, and EO are added and polymerized in this order to the tolylenediamine, the hydroxyl value is 350 mgKOH / g, and EO A polyether polyol in which the ratio of EO to the total of PO and PO is 25% by mass.
Polyol B: A polyether polyol having a hydroxyl value of 350 mgKOH / g, in which N- (2-aminoethyl) piperazine is used as an initiator and only EO is addition-polymerized to the N- (2-aminoethyl) piperazine.
Polyol C: A polyether polyol having a hydroxyl value of 380 mg KOH / g, in which a mixture of sucrose and glycerin (mass ratio of 5: 4) is used as an initiator, and only PO is subjected to addition polymerization.

From the results shown in Table 2, it was confirmed that Test Examples 1 to 7 using the polymer-dispersed polyols F1 to F7 had good storage stability.
On the other hand, Test Example 8 using PTFE powder was confirmed to have poor storage stability.
Therefore, it was confirmed that the polymer-dispersed polyols F1 to F7 according to the present invention are highly compatible with the polyol for rigid polyurethane foam and have excellent storage stability when a mixture thereof is stored.

≪Evaluation of rigid polyurethane foam≫
According to the blending ratios of Production Examples 11 to 18 shown in Table 3, rigid polyurethane foams were produced by the following production method.
In the composition of Table 3, the unit of the amount of each raw material used is “part by mass”.

(Raw materials used).
-Polyol component Polyol A to C, PTFE powder: the same as those described in Table 2.
Polyol D, F1-F4, F6, F8: Same as those described in Table 1.

Flame retardant: Tris (2-chloropropyl) phosphate (trade name: TMCPP, manufactured by Daihachi Chemical Co., Ltd.).
-Foaming agent: water.
-Foam stabilizer: Silicone foam stabilizer (trade name: SZ-1671, manufactured by Toray Dow Corning).
Catalyst: N, N, N ′, N′-tetramethylhexamethylenediamine (trade name: TOYOCAT MR, manufactured by Tosoh Corporation).
Polyisocyanate: Polymethylene polyphenyl polyisocyanate (crude MDI) (trade name: MR-200, manufactured by Nippon Polyurethane Industry Co., Ltd.).

<Manufacture of rigid polyurethane foam>
Into a 1 L poly beaker, 100 parts by mass of a polyol component shown in Table 3, 6 parts by mass of a foaming agent, 1 part by mass of a foam stabilizer, 0.5 part by mass of a catalyst and 10 parts by mass of a flame retardant were respectively added. Mix well to obtain a polyol system solution.
The amount of polyisocyanate used was 110 in terms of isocyanate index (INDEX).
After keeping the liquid temperature of both the polyol system liquid and the raw material of the polyisocyanate component at 20 ° C., the mixture was stirred and mixed at a rotational speed of 3000 rpm for 5 seconds. Then, it put into the wooden box of length 200x width 200x height 200mm, free foaming was performed, and the rigid polyurethane foam was manufactured.

<Evaluation of rigid polyurethane foam>
In the obtained rigid polyurethane foam of each production example, gel time (second), box free density (unit: kg / m ³ ) as total density, compressive strength (unit: MPa), high temperature shrinkage (unit:%) as dimensional stability ) And the thermal conductivity (unit: mW / m · K) at 24 ° C. were measured as the heat insulation performance. Moreover, the following evaluation was performed as storage stability. The results are shown in Table 3.

The gel time was measured by inserting a wire into a foam in the middle of foaming and measuring the time (seconds) until stringing occurred when the foam was pulled up.
The total density (box-free density) was measured from the mass and volume according to JIS K7222 (1998 edition).
The compressive strength was measured according to JIS A9511. The size of the sample piece was 5 cm × 5 cm × 5 cm. Further, the compressive strength in the direction parallel to (//) and the direction perpendicular to the gravity direction (⊥) was measured. In Table 3, “// + ⊥” represents the compressive strength obtained by adding the compressive strength in the parallel direction (//) and the compressive strength in the vertical direction (⊥).

(Evaluation of dimensional stability)
High temperature shrinkage was measured by a method according to ASTM D 2126-75, and high temperature dimensional stability and wet heat dimensional stability were evaluated.
As a sample, the length (Z) 100 mm × width (X) 150 mm × thickness (Y) 75 mm of the rigid polyurethane foam of each example was cut out and used.
Specimens were stored for 24 hours in an atmosphere of high temperature dimensional stability of 70 ° C., wet heat dimensional stability of 70 ° C. and relative humidity of 95%, and the increased length (thickness) is the length before storage. It was expressed as a dimensional change rate (unit:%) with respect to (thickness). That is, the dimensional change rate was measured for all six directions in each of the three directions (X, Y, Z) under two conditions.
However, in the dimensional change rate, a negative value means shrinkage; a large absolute value means a large dimensional change. The dimensional change was evaluated according to the following evaluation criteria.
Evaluation criteria A: The maximum absolute value among the dimensional change rates in the six directions was less than 1%.
A: The maximum absolute value among the dimensional change rates in 6 directions was 1% or more and less than 5%.
Δ: The maximum absolute value among the dimensional change rates in 6 directions was 5% or more and less than 10%.
X: The maximum absolute value among the dimensional change rates in the six directions was 10% or more.

(Evaluation of thermal insulation)
The thermal conductivity (unit: mW / m · K) was measured using a thermal conductivity measuring device (product name: Auto Lambda HC-074, manufactured by Eiko Seiki Co., Ltd.) in accordance with JIS A1412.
The heat insulation was evaluated according to the following evaluation criteria.
Evaluation criteria ○: Thermal conductivity was 27 or less.
X: Thermal conductivity was more than 27.

(Evaluation of storage stability)
According to the blending ratios of Production Examples 11 to 18 shown in Table 3, after mixing polyol A, polyol B and polyol C, F1 to F4, F6, F8, PTFE powder and polyol D were added and mixed, respectively, and mixed polyol 300 g Was prepared and placed in a glass bottle with a lid. Then, it is stored at 23 ° C. for 1 week or at 23 ° C. for 1 month, and 100 g of the upper layer liquid is extracted from the upper layer of the mixed polyol after storage with a syringe, and the liquid is discarded so that 100 g of the lower layer liquid can be taken from the lower layer. A mixed polyol of 100 g of the lower layer solution was collected.
Next, in the above <Manufacture of rigid polyurethane foam>, in the same manner as in <Manufacture of rigid polyurethane foam> except that 100 parts by mass of the upper layer liquid or 100 parts by mass of the lower layer liquid was used instead of 100 parts by mass of the polyol component. A polyurethane foam was produced.
And the storage stability was evaluated based on the following evaluation criteria from the characteristic of the obtained rigid polyurethane foam.
When the storage stability is poor, the polymer-dispersed polyol migrates to the upper layer or the lower layer during storage, and the upper and lower compositions of the mixed polyol are different, which affects the characteristics of the rigid polyurethane foam produced using this. Therefore, the storage stability can be evaluated from the foamed state when each of the upper layer liquid and the lower layer liquid is used, or the dimensional change rate of the obtained rigid polyurethane foam.
Evaluation criteria (circle): The foaming defect was not seen in any which foamed the upper layer liquid and the lower layer liquid, and the absolute value of the dimensional change rate of the rigid polyurethane foam was all less than 5%.
X: Foaming failure was observed in any of the foamed upper layer liquid and lower layer liquid, or the absolute value of the dimensional change rate of any of the rigid polyurethane foams was 5% or more.

As is clear from the results shown in Table 3, the rigid polyurethane foams of Production Examples 11 to 15 according to the present invention produced using the polymer-dispersed polyols F1 to F4 and F6 have good dimensional stability and are sufficient. It was confirmed that it had a good heat insulation performance.
Moreover, when the mixture (mixed polyol) of polymer dispersion polyol F1-F4, F6 and the polyol for rigid polyurethane foams was stored, it turned out that each mixture is excellent in storage stability (1 week). Therefore, it has confirmed that the rigid polyurethane foam of the manufacture examples 11-15 concerning this invention can be manufactured stably.

Moreover, when the mixture (mixed polyol) of polymer dispersion polyol F1-F3 and the polyol for rigid polyurethane foams was stored, it has confirmed that each mixture was further excellent also in storage stability (for one month).
As a result, the oxyethylene group content in the polyether polyol is 60% by mass or more, and the use of the polymer-dispersed polyol containing acrylonitrile as the monomer having a polymerizable unsaturated group further improves the storage stability. It was found that the effect was obtained and the rigid polyurethane foam could be produced more stably.

On the other hand, when PTFE powder was used, it was confirmed that the storage stability (1 week, 1 month) was poor.
It was confirmed that the rigid polyurethane foam of Production Example 16 produced using the polymer-dispersed polyol F8 not using the fluorine-containing monomer (f) has poor heat insulation performance.
It was confirmed that the rigid polyurethane foam of Production Example 18 produced using Polyol D containing no polymer fine particles had poor dimensional stability.

  By the production method of the present invention, it is possible to obtain a rigid polyurethane foam that is reduced in weight and excellent in both heat insulation and dimensional stability. In addition, the polymer-dispersed polyol used in the present invention has good storage stability even when mixed with a low molecular weight polyol for rigid polyurethane foam. The manufacturing method of the rigid polyurethane foam of this invention can be utilized suitably for manufacture of an injection | pouring urethane foam, a continuous production board, spray foaming foam, etc.

Claims (9)

In a method for producing a rigid polyurethane foam by reacting a polyol component (Z) and a polyisocyanate component in the presence of a foaming agent, a foam stabilizer and a catalyst,
The polyol component (Z) has an average hydroxyl value of 200 to 800 mgKOH / g, and contains the following polymer-dispersed polyol (A).
However, the polymer-dispersed polyol (A) is a polymer in which polymer fine particles are dispersed in a polyol by polymerizing a monomer having a polymerizable unsaturated group in the polyol (X). The polyol (X) is a polyether. The monomer containing a polyol and having a polymerizable unsaturated group includes a fluorine-containing acrylate or a fluorine-containing methacrylate. The method for producing a rigid polyurethane foam according to claim 1, wherein the fluorine-containing acrylate or the fluorine-containing methacrylate is a monomer represented by the following formula (1).

However, in Formula (1), ^Rf is a C1-C18 polyfluoroalkyl group, R is a hydrogen atom or a methyl group, and Z is a bivalent coupling group.   The method for producing a rigid polyurethane foam according to claim 1 or 2, wherein the monomer having a polymerizable unsaturated group further contains acrylonitrile.   The method for producing a rigid polyurethane foam according to any one of claims 1 to 3, wherein the polyether polyol has an oxyethylene group content of 10% by mass or more.   The method for producing a rigid polyurethane foam according to any one of claims 1 to 4, wherein the polyether polyol has a hydroxyl value of 84 mgKOH / g or less.   The method for producing a rigid polyurethane foam according to any one of claims 1 to 5, wherein the polyether polyol is a polyoxyalkylene polyol obtained by addition polymerization of propylene oxide and ethylene oxide to a polyhydric alcohol.   The manufacturing method of the rigid polyurethane foam in any one of Claims 2-6 whose ratio of the monomer represented by the said Formula (1) in all the monomers which have the said polymerizable unsaturated group is 30-100 mass%.   The ratio of the polymer-dispersed polyol (A) in the polyol component (Z) is 0.8% by mass or more, and the ratio of the polymer fine particles in the polyol component (Z) is 0.1% by mass or more. The manufacturing method of the rigid polyurethane foam in any one of Claims 1-7.   The method for producing a rigid polyurethane foam according to any one of claims 1 to 8, wherein water is used alone or at least one selected from a hydrofluorocarbon compound and a hydrocarbon compound and water as the foaming agent.