JPH11106447A - Polymer-dispersed polyol, method for producing the same, and method for producing rigid polyurethane foam - Google Patents

Abstract

(57) [Summary] [Problem] To provide a low-density rigid foam excellent in dimensional stability. The polyether polyol has a hydroxyl value of 84 or less and an oxyethylene group content of 40% by weight or more.
Amine polyol having a hydroxyl value of 250 to 900 obtained by adding a cyclic ether to an amine compound in an amount of at least
A method for producing a polymer-dispersed polyol in which polymer fine particles are stably dispersed by polymerizing a monomer having a polymerizable unsaturated group in a polyol having an average hydroxyl value of 200 to 800, which contains at least% by weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polymer-dispersed polyol, a method for producing the same, and a method for producing a rigid polyurethane foam using the polymer-dispersed polyol.
In particular, it relates to a method for producing a rigid polyurethane foam having improved dimensional stability.

[0002]

2. Description of the Related Art A rigid polyurethane foam is obtained by reacting a polyol having a relatively high hydroxyl value and a polyisocyanate in the presence of additives such as a catalyst, a foaming agent and a foam stabilizer. Although CFC-11 has been mainly used as the blowing agent, the elimination of chlorofluorocarbon has been determined, and in recent years, hydrochlorofluorocarbon represented by HCFC-141b, water and low-boiling hydrocarbons have been widely adopted as blowing agents. ing.

[0003] Furthermore, to reduce the cost and weight by reducing the amount of raw materials used, it is desired to reduce the density of the foam. By switching from CFC-11 to the above foaming agent, the resin strength of the foam decreases, and the ,freezer,
There is a problem that a rigid polyurethane foam used in an insulated container or other low-temperature atmosphere shrinks. In order to prevent the foam from shrinking at a low temperature, a method of producing a rigid polyurethane foam by adding a polymer-dispersed polyol to a polyol having a high hydroxyl value is known (Japanese Patent Laid-Open No. 57-25313).

[0004] The polymer-dispersed polyol is a compound in which polymer fine particles obtained by polymerizing a monomer having a polymerizable unsaturated group are dispersed in a polyol such as a polyether polyol or a polyester polyol. And has been used to improve the physical properties of these polyurethane compositions. In the above technology for producing a rigid polyurethane foam having good dimensional stability by adding a polymer-dispersed polyol to a polyol having a high hydroxyl value,
It is considered that the polymer particles exert some action.

[0005] A method for producing a polymer-dispersed polyol is to prepare a polymerizable unsaturated group in a saturated polyol having no polymerizable unsaturated group, optionally under the condition that an unsaturated polyol having a polymerizable unsaturated group is present. It is known to carry out polymerization of a monomer having the compound and then remove unreacted components. As the polyol, various polyether polyols and polyester polyols are known.

[0006]

The above-mentioned conventional polymer-dispersed polyols have a low hydroxyl value (50 m), which is used as a raw material for flexible or semi-rigid polyurethane foams.
gKOH / g or less).
Therefore, the conventional low-hydroxyl value polymer-dispersed polyol has poor compatibility with the polyol for high rigidity polyurethane foam having a high hydroxyl value, and when used in combination, the low-hydroxyl value polyol or polymer fine particles are separated, or the polyol mixture thickens. It has been difficult to use a conventional low-hydroxyl value polymer-dispersed polyol as a raw material for a rigid polyurethane foam.

In general, when a monomer having a polymerizable unsaturated group is polymerized in a polyol to synthesize a polymer-dispersed polyol, the higher the hydroxyl value of the polyol (the lower the molecular weight of the polyol), the more stable the particle stability of the polyol. Therefore, aggregation of the particles during the process of growing the particles during polymerization is extremely likely to occur, and aggregates are generated.

JP-A-2-240125, JP-B-7-80
986 describes a polymer-dispersed polyol having a high hydroxyl value, but the method proposed here also did not provide sufficient dispersion stability of polymer fine particles.

In order to solve the problems described above, the present invention provides a hard polyurethane having excellent compatibility with polyols for rigid polyurethane foams, good dispersion stability, low viscosity, and high dimensional stability at low temperatures. An object of the present invention is to provide a polymer-dispersed polyol having a high hydroxyl value capable of producing a polyurethane foam.

[0010]

Means for Solving the Problems The present invention is the following invention. In a polymer-dispersed polyol in which polymer particles obtained by polymerizing a monomer having a polymerizable unsaturated group are stably dispersed in a polyol (W) having an average hydroxyl value of 200 to 800 mgKOH / g, the polyol (W)
Is a polyether polyol (X) having a hydroxyl value of 84 mgKOH / g or less and an oxyethylene group content of 40% by weight or more, 5% by weight or more, and a hydroxyl value 250 to 900 mgKOH obtained by adding a cyclic ether to an amine compound.
/ G of amine-based polyol (Y) 3% by weight or more, and
A polymer-dispersed polyol, which is a polyol mixture optionally comprising another polyol (Z).

Average hydroxyl value 200 to 800 mg KOH
/ G polyol (W) in a method for producing a polymer-dispersed polyol in which polymer particles are stably dispersed by polymerizing a monomer having a polymerizable unsaturated group, the polyol (W) has a hydroxyl value of 84 mgKOH / g A polyether polyol (X) having an oxyethylene group content of 40% by weight or more and a hydroxyl value of 250 to 90 obtained by adding a cyclic ether to an amine compound.
0 mgKOH / g amine-based polyol (Y) 3% by weight
A method for producing a polymer-dispersed polyol, which is a polyol mixture comprising the above and, optionally, another polyol (Z).

In a method for producing a rigid polyurethane foam by reacting a polyol (V) and a polyisocyanate in the presence of a foam stabilizer, a catalyst and a foaming agent, at least 0.1% by weight of the polyol (V) is claimed. Item 4. A method for producing a rigid polyurethane foam, which is the polymer-dispersed polyol according to Item 1, wherein the proportion of polymer fine particles in the polymer-dispersed polyol is 0.01% by weight or more based on the total weight of the polyol (V).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

[Polyol] In the present invention, a polyol used as a raw material of a polymer-dispersed polyol or a raw material of a rigid polyurethane foam will be described. Examples of such polyols include polyether polyols, polyester polyols, hydrocarbon polymers having a hydroxyl group at a terminal, and the like.Especially, only a polyether polyol is used, or a small amount of a polyester polyol containing the polyether polyol as a main component or a hydroxyl group at a terminal. Is preferably used in combination with a small amount of a hydrocarbon-based polymer or the like.

Examples of the polyether polyol include polyether polyols obtained by adding a cyclic ether such as an alkylene oxide to an initiator such as a polyhydroxy compound such as a polyhydric alcohol or a polyhydric phenol or an amine. Specific examples of the initiator include the following compounds, their cyclic ether adducts, and mixtures of two or more of them.

Water, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylol Propane, 1,2,6-hexanetriol, pentaerythritol, diglycerin, tetramethylolcyclohexane, methylglucoside, sorbitol, mannitol,
Polyhydric alcohols such as dulcitol and sucrose. Polyphenols such as bisphenol A and phenol-formaldehyde precondensate. Piperazine, aniline, monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, aminoethylethanolamine, ammonia, N-aminomethylpiperazine, N- (2-aminoethyl) piperazine, ethylenediamine, propylenediamine, hexamethylenediamine, Amines such as tolylenediamine, xylylenediamine, diphenylmethanediamine, diethylenetriamine and triethylenetetramine.

The cyclic ether used in the present invention includes a 3- to 6-membered cyclic ether compound having one oxygen atom in the ring, and specific examples thereof include the following compounds.

Ethylene oxide, propylene oxide,
Isobutylene oxide, 1-butylene oxide, 2-butylene oxide, trimethylethylene oxide, tetramethylethylene oxide, butadiene monoxide, 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, cyclohexene oxide, dihydronaphthalene oxide, vinylcyclohexene monoxide, etc. Compounds having a 3-membered cyclic ether group; oxetane, tetrahydrofuran, tetrahydrid Compounds having a 4- to 6-membered cyclic ether group such as ropyran.

Preferred are compounds having one 3-membered cyclic ether group (monoepoxides), and particularly preferred compounds are alkylene oxides having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, isobutylene oxide and 1-butene oxide. , 2-butene oxide.

Two or more of these cyclic ethers can be used in combination. In this case, they can be mixed and reacted, or can be sequentially reacted. Particularly preferred cyclic ethers are alkylene oxides having 2 to 4 carbon atoms, especially propylene oxide, or a combination of propylene oxide and ethylene oxide.

Examples of the polyester polyol include a polyester polyol obtained by polycondensation of a polyhydric alcohol and a polycarboxylic acid. In addition, polycondensation of hydroxycarboxylic acid, cyclic ester (lactone)
, Polyaddition of cyclic ether to polycarboxylic anhydride, and polyester polyol obtained by transesterification of waste polyethylene terephthalate.

[Polyol (W)] The polyol (W) used in the polymer-dispersed polyol of the present invention is a combination of the following specific polyols among the above polyols.

That is, a polyether polyol (X) having a hydroxyl value of 84 mg KOH / g or less and an oxyethylene group content of 40% by weight or more, 5% by weight or more, and a hydroxyl value 250 obtained by adding a cyclic ether to an amine compound.
-900 mgKOH / g amine-based polyol (Y) 3
% Or more, and optionally a polyol mixture consisting of another polyol (Z).

The polyol (W) is particularly preferably a polyol mixture comprising a polyether polyol (X), an amine polyol (Y), and another polyol (Z).

The polyol (W) comprises 10 to 60% by weight of a polyether polyol (X), 5 to 35% by weight of an amine-based polyol (Y), and 10% by weight of another polyol.
Preferably it is a mixture of up to 85% by weight. 25-50% by weight of polyether polyol (X), 8-30% by weight of amine-based polyol (Y) and other polyol 2
Particularly preferred is a mixture of 5 to 67% by weight.

The average hydroxyl value of the polyol (W) is 20
0 to 800 mgKOH / g, preferably 250 to
750 mg KOH / g. When the average hydroxyl value of the polyol (W) is lower than this range, the produced polymer-dispersed polyol has poor compatibility with the polyol for a rigid polyurethane foam having a high hydroxyl value, and when used in combination, the polyol (polymer fine particles) is separated or thickened. Therefore, it becomes difficult to use as a raw material for a rigid polyurethane foam. When the average hydroxyl value of the polyol (W) used for producing the polymer-dispersed polyol is high, it is difficult to obtain a polymer-dispersed polyol in which polymer fine particles are stably dispersed. Hereinafter, (X), (Y), and (Z) will be described.

[Polyether polyol (X)] The polyether polyol (X) in the present invention is preferably a polyether polyol having three or more functional groups among the polyether polyols described in the above section of "Polyol". Further, a polyether polyol described below is preferable.

That is, those obtained by using a polyhydric alcohol as an initiator and adding ethylene oxide or ethylene oxide to another cyclic ether are preferable. As the polyhydric alcohol, trihydric alcohols such as glycerin, trimethylolpropane and 1,2,6-hexanetriol are preferred. As the other cyclic ether used in combination with ethylene oxide, propylene oxide, isobutylene oxide, 1-butylene oxide, and 2-butylene oxide are preferable, and propylene oxide is particularly preferable.

The polyether polyol (X) is a polyether polyol having a hydroxyl value of 84 mgKOH / g or less. When the hydroxyl value exceeds 84 mgKOH / g, the dispersion stability of the particles in the polymer-dispersed polyol decreases. A polyether polyol having a hydroxyl value of 67 mgKOH / g or less is preferable. Hydroxyl value 60mgKO
It is particularly preferred that it is H / g or less. Although the lower limit of the hydroxyl value of the polyether polyol (X) is not particularly limited, 5 mg
KOH / g or more, preferably 8 mg KOH / g.
g or more is more preferable. 20mgKOH / g
It is particularly preferable that the amount is at least 30 mgKOH / g.

The polyether polyol (X) must have an oxyethylene group content of at least 40% by weight. If the oxyethylene group content is lower than this, it is difficult to obtain a polymer-dispersed polyol in which polymer fine particles are stably dispersed. It is particularly preferred that the oxyethylene group content is 50% by weight or more. Most preferably, the oxyethylene group content is 55% by weight or more. The upper limit of the oxyethylene group content is preferably about 100% by weight,
More preferably, it is 90% by weight.

The content of the polyether polyol (X) is
It is 5% by weight to 97% by weight of the polyol (W).
When the amount of the polyether polyol (X) is lower than 5% by weight, it is difficult to obtain a polymer-dispersed polyol having good dispersibility. It is preferably from 10 to 60% by weight, and
Particularly preferred is 50% by weight.

[Amine-based polyol (Y)] The amine-based polyol (Y) is a polyol having a hydroxyl value of from 250 to 250 obtained by adding a cyclic ether to an amine compound as an initiator among the polyols described in the above section "Polyol". 900mg
It is a KOH / g polyol. Hydroxyl value 300-80
0 mgKOH / g, and a hydroxyl value of 35 mgKOH / g.
It is particularly preferred that it is 0 to 800 mgKOH / g.

As the amine compound, an aliphatic amine compound or a saturated cyclic amine compound is preferable. As the aliphatic amine compound, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine,
Triethylenetetramine and the like. As the saturated cyclic amine compound, N-aminomethylpiperazine, N-
(2-aminoethyl) piperazine and the like.

The content of the amine polyol (Y) is at least 3% by weight of the polyol (W). When the content of the amine polyol (Y) is lower than 3% by weight, the effect of improving the dimensional stability of the rigid polyurethane foam produced using the polymer-dispersed polyol is low. The upper limit is preferably 35% by weight. If it is higher than 35% by weight, it is difficult to obtain a polymer-dispersed polyol having low viscosity and good dispersibility. The content of the amine polyol (Y) is preferably from 5 to 30% by weight, most preferably from 8 to 25% by weight.

[Polyol (Z)] Polyol (W)
May optionally contain another polyol (Z) in addition to the polyether polyol (X) and the amine-based polyol (Y). It is particularly preferable that the polyol (W) optionally contains other polyol (Z) in addition to the polyether polyol (X) and the amine-based polyol (Y).

As the polyol (Z), a hydroxyl value of 20
Those having a hydroxyl value of from 400 to 850 mgKOH / g are particularly preferred. As the polyol (Z), polyols other than the polyether polyol (X) and the amine-based polyol (Y) among the polyols described in the section of “Polyol” can be used.

The content of the polyol (Z) in the polyol (W) is from 0 to 92% by weight. It is preferably from 10 to 85% by weight, particularly preferably from 25 to 68% by weight.

[Polymer-dispersed polyol] There are, for example, two methods for producing a polymer-dispersed polyol using the polyol (W). The first method is a method in which a monomer having a polymerizable unsaturated group in a polyol (W) is polymerized in the presence of a solvent, if necessary, to directly precipitate particles. A method in which a monomer having a polymerizable unsaturated group is polymerized in a solvent in the presence of a grafting agent to be stabilized to precipitate particles, and then the polyol (W) and the solvent are replaced to obtain a stable dispersion. . In the present invention, either method can be adopted, and the first method is particularly preferable.

As the monomer having a polymerizable unsaturated group used in the present invention, a monomer having one polymerizable double bond is usually used, but is not limited thereto. Specific monomers include acrylic acid, methacrylic acid or an alkyl ester thereof, acrylic monomers such as acrylonitrile, methacrylonitrile, acrylamide, and methacrylamide; cyano group-containing olefin monomers such as 2,4-dicyanobutene-1; Styrene monomers such as styrene, α-methylstyrene and halogenated styrene; vinyl carboxylate monomers such as vinyl acetate and vinyl propionate; isoprene, butadiene, and other diene monomers; non-esters such as maleic diester and itaconic diester Saturated fatty acid esters; vinyl halides such as vinyl chloride, vinyl bromide and vinyl fluoride; vinylidene halides such as vinylidene chloride, vinylidene bromide and vinylidene fluoride; methyl vinyl ether, ethyl Vinyl ether, alkyl vinyl ether monomer such as isopropyl vinyl ether and olefins other than these, and the like halogenated olefin.

Preferably, a combination of 20 to 90% by weight of acrylonitrile and 10 to 80% by weight of another monomer is used, and as the other monomer, styrene, alkyl acrylate, alkyl methacrylate and vinyl acetate are preferred. These other monomers may be used in combination of two or more kinds.

The amount of the monomer used is not particularly limited, but is preferably such that the polymer concentration of the finally obtained polymer-dispersed polyol is about 1 to 50% by weight, particularly preferably 2 to 45% by weight. And most preferably 15 to 40% by weight.

In the polymerization of a monomer having a polymerizable unsaturated group, a polymerization initiator of the type which generates free radicals and initiates polymerization is usually used. Specifically, for example, 2,2-azobis-isobutyronitrile (AIBN), 2,2-azobis-2-methylbutyronitrile, 2,2-azobis-
Examples include 2,4-dimethylvaleronitrile, benzoyl peroxide, diisopropyl peroxydicarbonate, diacetyl peroxide, di-t-butyl peroxide, persulfate and the like. In particular, AIBN, 2,2-azobis-2
-Methylbutyronitrile is preferred.

The polymerization reaction is carried out at a temperature higher than the decomposition temperature of the polymerization initiator, usually at 80 to 160 ° C., preferably 90 to 150 ° C.
° C, particularly preferably in the range of 100 to 135 ° C.

Conventionally, in a method for producing a polymer-dispersed polyol, a part of the polyol is charged into a reactor and stirred under stirring.
A batch method in which a mixture of the remaining polyol, a monomer having a polymerizable unsaturated group, a polymerization initiator, and the like is gradually fed into the reactor to perform polymerization, a polyol, a monomer having a polymerizable unsaturated group, a polymerization initiator There is a continuous method in which the mixture is continuously fed to the reactor with stirring, and the polymer composition produced at the same time is continuously discharged from the reactor. The present invention can be produced by either of these methods.

In general, the higher the polymer concentration, the more the particles aggregate during the process of growing the particles during monomer polymerization, and the more easily aggregates are formed. In order to prevent this, the polymer-dispersed polyol can be produced in the presence of a solvent.

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. Hydrogen; ketones such as acetone, 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-t-butyl ether; chlorobenzene, chloroform and dichloroethane Halogenated hydrocarbons such as 1,1,1,2-trichlorotrifluoroethane; nitro compounds such as nitrobenzene; nitriles such as acetonitrile and benzonitrile S; trimethylamine, triethylamine, tributylamine, amines dimethylaniline; N, N- dimethylformamide, amides such as N- methyl pyrrolidone; dimethyl sulfoxide, and the like sulfur compounds such as sulfolane.

In the present invention, these solvents can be used alone or as a mixture. After the polymerization of the monomer having a polymerizable unsaturated group is completed, the solvent is removed. The solvent is usually removed by heating under reduced pressure. However, it can also be carried out under normal pressure heating or reduced pressure at normal temperature. At this time, unreacted monomers are removed together with the solvent.

Although a polymer-dispersed polyol in which polymer particles are stably dispersed can be obtained by the above-mentioned production method, a stable dispersion may be difficult to obtain depending on the monomer used. In order to further improve the dispersion stability of the particles, a compound having a polyether chain or a polyester chain and a polymerizable compound having a double bond in the molecule can be used as a stabilizer or a grafting agent.

Such a stabilizer or grafting agent is obtained by reacting an alkylene oxide with an active hydrogen compound having a double bond-containing group such as a vinyl group, an allyl group or an isopropenyl group as an initiator. High molecular weight polyol or monool; required to react with polyether polyol with unsaturated carboxylic acid such as maleic anhydride, itaconic anhydride, maleic acid, fumaric acid, acrylic acid, methacrylic acid or its anhydride. A high molecular weight polyol or monool obtained by adding an alkylene oxide such as propylene oxide or ethylene oxide accordingly;
A reaction product of an unsaturated group-containing alcohol such as 2-hydroxyethyl acrylate and butenediol with another polyol and a polyisocyanate; and a reaction product of an unsaturated group-containing epoxy compound such as allyl glycidyl ether and a polyol. These compounds preferably have a hydroxyl group, but are not limited thereto.

The hydroxyl value of the polymer-dispersed polyol is 20
0 to 800 mgKOH / g, preferably 20 to
It is more preferably 0 to 750 mgKOH / g,
It is particularly preferred that it is 250 to 750 mgKOH / g. It is usually lower than the polyol used as the base.

The polymer-dispersed polyol of the present invention obtained as described above is preferably one which does not cause separation in a stationary state for 1 month or more, particularly 2 months or more, but is not limited thereto. The reason why the polymer-dispersed polyol of the present invention has such excellent dispersion stability is presumed to be that the size of polymer fine particles obtained by polymerizing a monomer having a polymerizable unsaturated group is fine and uniform.

Hereinafter, the polymer-dispersed polyol in the present invention is referred to as polymer-dispersed polyol (T).

[Rigid Polyurethane Foam] The present invention is also a method for producing a rigid polyurethane foam in which a polyol (V) containing the above-mentioned polymer-dispersed polyol (T) is reacted with a polyisocyanate compound. That is,
In a method for producing a rigid polyurethane foam by reacting a polyol (V) and a polyisocyanate in the presence of a foam stabilizer, a catalyst and a foaming agent, 0.1% by weight or more of the polyol (V) is a polymer-dispersed polyol ( T)
And the proportion of polymer fine particles in the polymer-dispersed polyol (T) is at least 0.01% by weight based on the total weight of the polyol (V).

The polymer-dispersed polyol (T) can be used alone as a raw material for a rigid polyurethane foam. That is, 100% by weight of the polyol (V) may be the polymer-dispersed polyol (T), but it is preferable that the polyol (V) is used by mixing with a polyol which is usually used as a raw material of a rigid polyurethane foam.

The average hydroxyl value of the polyol (V) is 2
The average hydroxyl value is preferably from 50 to 800 mgKOH / g, more preferably from 300 to 750 mgKOH / g.
/ G. 0.1% by weight of the polyol (V)
The above is the polymer-dispersed polyol (T).
It is preferable that 3% by weight or more is the polymer-dispersed polyol (T).

Further, the polymer fine particles in the polymer-dispersed polyol (T) must be at least 0.01% by weight based on the total weight of the polyol (V). If the proportion of the polymer fine particles is smaller than this, a rigid polyurethane foam having excellent low-temperature dimensional stability is difficult to obtain.
It is particularly preferred that the content be 0.05% by weight or more. Also 5
It is preferably at most 0% by weight, particularly preferably at most 30% by weight. More preferably it is less than 5% by weight, most preferably less than 2% by weight.

Polyols other than the polymer-dispersed polyol (T) and which can be used as the polyol (V) include polyether polyols, polyester polyols, and carbonized terminals having hydroxyl groups at the terminals as described in the section of “Polyol” above. Hydrogen polymers and the like can be mentioned. Also, phenols, alkanolamines,
A polyether polyol obtained by adding a cyclic ether to a reaction product obtained by reacting an aldehyde by a Mannich reaction, and the like can also be used. The above (W),
(X), (Y), and (Z) can also be used.

Further, compounds having a relatively low molecular weight, such as a chain extender and a crosslinking agent, can also be used as a part of the polyol (V). For example, there are polyhydric alcohols, alkanolamines, saccharides, polyamines, monoamines, polyhydric phenols and the like, and low molecular weight polyether polyols obtained by adding a small amount of alkylene oxide thereto.
Furthermore, low molecular weight polyester-based polyols and the like can also be used.

Preferably, polyhydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol and glycerin; alkanolamines such as diethanolamine and triethanolamine; polyamines such as hexamethylenediamine and 4,4-diaminodiphenylmethane; And a polyether polyol having a hydroxyl value of 300 mgKOH / g or more is used.

Examples of the polyisocyanate compound include aromatic, alicyclic and aliphatic polyisocyanates having two or more isocyanate groups, mixtures of two or more thereof, and modified polyisocyanates obtained by modifying them. There is. Specifically, for example, tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate (commonly known as Crude M)
DI), xylylene diisocyanate, isophorone diisocyanate, polyisocyanates such as hexamethylene diisocyanate and their prepolymer-modified products,
Nurate-modified, urea-modified, carbodiimide-modified and the like.

As the catalyst, those usually used for producing rigid polyurethane foam can be used, and amine catalysts such as tertiary amines and organometallic compounds such as organotin compounds are suitable. As the foam stabilizer, those usually used when producing a rigid polyurethane foam can be used,
Organosilicon surfactants are suitable.

Examples of the blowing agent include water, halogenated hydrocarbons, low-boiling hydrocarbons, and monochlorofluoromethane (H
CFC-22), 1,1-dichloro-1-fluoroethane (HCFC-141b), 1-chloro-1,1-difluoroethane (HCFC-142b), 1,1-dichloro-2,2,2-trifluoro Ethane (HCFC-12
3), 1,1,1,2-tetrafluoroethane (HFC
-134a), 1,1,1,3,3-pentafluoropropane (HFC-245fa), methylene chloride and other halogenated hydrocarbons are suitable. Two or more foaming agents may be used in combination. Particularly preferred blowing agents are water, HCFC-1
41b, HFC-134a, HFC-245fa and combinations thereof.

The amount of the halogenated hydrocarbon blowing agent to be used is preferably from 1 to 70 parts by weight, particularly preferably from 10 to 60 parts by weight, per 100 parts by weight of the polyol (V). When water is used, the amount is 0.1 to 10 parts by weight per 100 parts by weight of the polyol (V) (water is not calculated as a polyol).
Part by weight is preferred, and 1.0 to 10 parts by weight is particularly preferred.

Further, a stabilizer, a coloring agent, a filler, a flame retardant,
Other additives may be added. The rigid polyurethane foam in the present invention is produced by using the above-mentioned raw materials by various known methods for producing this type of foam.
For example, it can be manufactured by a one-shot method, a spray method, a prepolymer method, a quasi-prepolymer method, an RIM method, or the like.

The rigid polyurethane foam of the present invention is particularly suitable for a relatively low-density rigid polyurethane foam. That is, a high-density rigid polyurethane foam is inherently excellent in dimensional stability, and little improvement is required. The rigid polyurethane foam according to the present invention has a density of 40 kg / m ³ or less, especially 1 kg / m ³ or less.
0~40kg / m ^3, more preferably 15~35kg / m ^3.

[0065]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. In the table, AN
Represents acrylonitrile, St represents styrene, Vac represents vinyl acetate, and MMA represents methyl methacrylate. The numbers without units in the table represent parts by weight.

The polyols shown in the examples and comparative examples are as follows. Polyol A: a polyether polyol having a hydroxyl value of 450 mgKOH / g obtained by adding propylene oxide to glycerin. Polyol B: a polyether polyol having a hydroxyl value of 650 mgKOH / g obtained by adding propylene oxide to glycerin.

Polyol C: a polyether polyol having a hydroxyl value of 50 mgKOH / g and an oxyethylene group content of 25% by weight obtained by randomly adding propylene oxide and ethylene oxide to glycerin. Polyol D: a polyether polyol having a hydroxyl value of 50 mgKOH / g and an oxyethylene group content of 55% by weight obtained by randomly adding propylene oxide and ethylene oxide to glycerin. Polyol E: a polyether polyol having a hydroxyl value of 50 mgKOH / g and an oxyethylene group content of 75% by weight obtained by randomly adding propylene oxide and ethylene oxide to glycerin.

Polyol F: Hydroxyl value obtained by adding propylene oxide to ethylenediamine 760 mgK
OH / g polyether polyol. Polyol G: a polyether polyol having a hydroxyl value of 500 mgKOH / g obtained by adding propylene oxide to ethylenediamine. Polyol H: hydroxyl value obtained by adding propylene oxide to aminomethylpiperazine 550 mgKOH /
g of polyether polyol.

Polyol I: Hydroxyl value 450 obtained by adding propylene oxide to m-toluylenediamine
mg KOH / g polyether polyol. Polyol J: sucrose / glycerin weight ratio 2
A polyether polyol having a hydroxyl value of 550 mgKOH / g, obtained by adding propylene oxide to the mixture of / 1. Polyol K: hydroxyl value obtained by adding propylene oxide to Mannich reaction condensate of phenol / formaldehyde / diethanolamine 540 mgKOH / g
Polyether polyol.

Polyol L: hydroxyl value 500 mg KOH obtained by adding propylene oxide to sorbitol
/ G of polyether polyol. Polyol M: 450 mg of hydroxyl value obtained by adding propylene oxide to a Mannich reaction condensate of phenol / aniline / formaldehyde / diethanolamine
KOH / g polyether polyol.

Polyol N: A polyether polyol having a hydroxyl value of 26 mgKOH / g and an oxyethylene group content of 30% by weight obtained by adding propylene oxide and ethylene oxide in this order to glycerin. Polyol O: hydroxyl value 56 obtained by adding propylene oxide and ethylene oxide in this order to glycerin
mgKOH / g, polyether polyol having an oxyethylene group content of 10% by weight. Polyol P: In polyol K, acrylonitrile /
A polymer-dispersed polyol having a hydroxyl value of 45 mgKOH / g obtained by reacting a styrene monomer (= 3/1 weight ratio).

(Examples 1 to 11: Production Examples of Polymer-Dispersed Polyol) 70% by weight of the mixture of polyols shown in Tables 1 and 2 was charged into a 5 L pressure reactor and the remaining mixture of polyols was maintained at 120 ° C. The mixture of the monomer and AIBN shown in Tables 1 and 2 was fed over 4 hours with stirring, and after the completion of all feeds, stirring was continued at the same temperature for about 0.5 hour. In all cases, the conversion of the monomer was 90% or more. After the reaction, remove unreacted monomer
The polymer was removed by heating and degassing under reduced pressure at 0.1 mmHg for 2 hours at 20 ° C. to produce a polymer dispersed polyol. Tables 1 and 2 show the respective hydroxyl value (unit: mgKOH / g), viscosity at 25 ° C (unit: cP) and dispersion stability.

Examples 1 to 5 are examples. In each of Examples 1 to 5, a completely stable dispersion was obtained for 2 months or more.
The polymer-dispersed polyols obtained in Examples 1 to 5 are referred to as polyols a to e, respectively.

Examples 6 to 11 are comparative examples in which a polymer-dispersed polyol was produced without using the amine-based polyol (Y) in the present invention. When the particles settled or violently aggregated, the entire polymer-dispersed polyol coagulated or phase-separated. In each case, a uniform dispersion was not obtained, and the viscosity could not be measured.

(Examples 12 to 27: Production Examples of Rigid Polyurethane Foams) Total 100 parts by weight of polyol (or mixture) shown in Tables 3 to 5, 3.0 parts by weight of water, HCFC-14
1b in the table, N, N-dimethylcyclohexylamine (DMCHA) in the table, and a silicone foam stabilizer (manufactured by Toray Dow Corning Silicone Co., Ltd.
SH-193) and 1.5 parts by weight of tris (2-chloropropyl) phosphate as a flame retardant (manufactured by Daihachi Chemical Co., Ltd.)
A mixture of 10 parts by weight of TMCPP) and polymethylene polyphenylisocyanate (Millionate MR-200, manufactured by Nippon Polyurethane Co., Ltd.) were stirred and mixed so as to have an index of 110 (liquid temperature: 20 ° C.).
It was put into a wooden box of mm × 200 mm and foamed.

Core density (unit: kg / m ³ ), compressive strength (unit: kg / cm ² ), thermal conductivity (unit: kcal /
m · hr · ° C.) and low-temperature dimensional stability (in the table, dimensional stability, unit:%) are shown in Tables 3 to 5. The compressive strength indicates a compressive strength in a direction parallel to the foaming direction. The dimensional stability indicates a dimensional change rate in the direction perpendicular to the foaming direction after 24 hours at −30 ° C.

Examples 12 to 21 are examples in which rigid polyurethane foams were produced using the polyols a to e produced in Examples 1 to 5. Unlike Examples 22 to 27, the dimensional stability at low temperature was significantly improved without deteriorating other physical properties.

Example 22 is a comparative example in which polyurethane foaming was performed without using the polymer-dispersed polyol, and Examples 23 to 27 were performed without using the polymer-dispersed polyol of the present invention. After 24 hours at −30 ° C., all of the foams shrank significantly.

[0079]

[Table 1]

[0080]

[Table 2]

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[Table 3]

[0082]

[Table 4]

[0083]

[Table 5]

[0084]

According to the present invention, the polymer-dispersed polyol having a high hydroxyl value, which has a good dispersion stability and a low viscosity, remarkably improves the dimensional stability at low temperature of a rigid polyurethane foam produced using the polyol. Therefore,
The present invention exerts an excellent effect on lowering the density of the rigid polyurethane foam.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Minako Okamura 3-474-2 Tsukakoshi, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Asahi Glass Co., Ltd. Inside the corporation

Claims (4)

[Claims] 1. An average hydroxyl value of 200 to 800 mg KOH.
/ G of polyol (W) in which polymer fine particles obtained by polymerizing a monomer having a polymerizable unsaturated group are stably dispersed, wherein the polyol (W) has a hydroxyl value of 84 mgKOH / g or less. A polyether polyol (X) having an oxyethylene group content of 40% by weight or more and a hydroxyl value of 250 to 900 mg obtained by adding a cyclic ether to an amine compound.
KOH / g amine-based polyol (Y) 3% by weight or more,
And a polymer-dispersed polyol characterized by being a polyol mixture optionally comprising another polyol (Z). 2. An average hydroxyl value of 200 to 800 mg KOH.
/ G polyol (W) in a method for producing a polymer-dispersed polyol in which polymer particles are stably dispersed by polymerizing a monomer having a polymerizable unsaturated group, the polyol (W) has a hydroxyl value of 84 mgKOH / g A polyether polyol (X) having an oxyethylene group content of 40% by weight or more and a hydroxyl value of 250 to 90 obtained by adding a cyclic ether to an amine compound.
0 mgKOH / g amine-based polyol (Y) 3% by weight
A method for producing a polymer-dispersed polyol, which is a polyol mixture comprising the above and, optionally, another polyol (Z). 3. A method for producing a rigid polyurethane foam by reacting a polyol (V) and a polyisocyanate in the presence of a foam stabilizer, a catalyst and a foaming agent, wherein at least 0.1% by weight of the polyol (V) is contained. Is a polymer-dispersed polyol according to claim 1, wherein the proportion of polymer fine particles in the polymer-dispersed polyol is at least 0.01% by weight based on the total weight of the polyol (V). Method. 4. The rigid polyurethane foam has a density of 40 k.
The method for producing a rigid polyurethane foam according to claim ^3, which is not more than g / m3.