JPH0730157B2 - Polyurethane foam manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyurethane.

[Prior Art] Conventionally, as a method for producing a polyurethane foam, when a urethane foam is produced using an organic polyisocyanate and an active hydrogen atom-containing compound, styrene and acrylonitrile are used as at least a part of the active hydrogen atom-containing compound in a polyether polyol. A method of using a polymer polyol obtained by polymerizing is known.

[Problems to be Solved by the Invention] However, this method for producing a polyurethane foam has a problem that the viscosity of the polymer polyol becomes high if the foam hardness is intended.

[Means for Solving Problems] The present inventors have arrived at the present invention as a result of extensive studies on a method of producing a polyurethane having high hardness by using a modified polyol having low viscosity.

That is, the present invention is a method for producing a polyurethane foam by reacting a polyisocyanate and an active hydrogen atom-containing compound in the presence of a foaming agent and, if necessary, a catalyst and other additives, in which the active hydrogen atom-containing compound is,
A polymer obtained by polymerizing 0.5 to 50% by weight of an α-olefin having 8 to 20 carbon atoms and 95.5 to 50% by weight of another ethylenically unsaturated monomer (ii) in a polyether polyol (i). A method for producing a polyurethane foam is characterized by containing at least 5% by weight of a polyol.

The α-olefin used in the present invention has 8 to 20 carbon atoms, preferably 11 to 18 carbon atoms. If the carbon number of the α-olefin is less than 5, the boiling point is too low, and if it exceeds 30, it is crystallized.

Specific examples of the α-olefin include octene, decene, dodecene, tetradecene, hexadecene, octadecene, eicosene, heneicosene, docosene, tricosene, tetracocene, pentacocene, hexacocene and a mixture of two or more thereof.

As the other ethylenically unsaturated monomer (ii) in the present invention, aromatic hydrocarbon monomers, unsaturated nitriles and (meth) acrylic acid esters are preferable.

Examples of the aromatic hydrocarbon monomers include styrene and α-methylstyrene.

Examples of unsaturated nitriles include (meth) acrylonitrile.

As (meth) acrylic acid esters, (meth) acrylic acid alkyl ester (alkyl group having 1 to 30 carbon atoms)
Specifically, methyl (meth) acrylate, butyl (meth) acrylate, nonyl (meth) acrylate,
Decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, eicosyl (meth) Examples thereof include (meth) acrylate and docosyl (meth) acrylate.

In addition to the above, other monomers can be used if necessary. Examples of this monomer include ethylenically unsaturated carboxylic acids and their derivatives [(meth) acrylic acid, (meth) acrylamide, etc.], aliphatic hydrocarbon monomers [ethylene,
Propylene, etc., fluorine-containing vinyl monomers [perfluorooctylethyl methacrylate, perfluorooctylethyl acrylate, etc.], nitrogen-containing vinyl monomers [dimethylaminoethyl methacrylate, morpholinoethyl methacrylate, etc.], vinyl-modified silicone at both ends, etc. can give.

The content of α-olefin in the ethylenically unsaturated monomer (ii) is usually 0.5 to 50% by weight, preferably 1 to 20% by weight. If the content of α-olefin is less than 0.5% by weight, the viscosity becomes high, and if it exceeds 50% by weight, foaming of the foam becomes difficult.

The content of aromatic hydrocarbon monomers in the ethylenically unsaturated monomer (ii) is usually 0 to 90% by weight, preferably 0 to 80% by weight. When the content of aromatic hydrocarbon monomers exceeds 90% by weight, it becomes soft.

The content of unsaturated nitriles in the ethylenically unsaturated monomer (ii) is usually 0 to 99.5% by weight, preferably 20 to 99.5% by weight.
Is. When the content of unsaturated nitriles exceeds 99.5% by weight, the viscosity becomes high.

The (meth) acrylic acid ester is 0 to 50% by weight, preferably 0 to 20% by weight. When the content of (meth) acrylic acid ester exceeds 50% by weight, the viscosity becomes high.

The weight ratio of aromatic hydrocarbon monomers to unsaturated nitriles is usually 0: 100 to 80:20, preferably 0: 100 to 70:30.

The polyether polyol (i) used in the production of the polymer polyol used in the present invention is a compound having at least 2 (preferably 2 to 8) active hydrogen atoms (for example, polyhydric alcohol, polyhydric phenol, amine). Compounds, polycarboxylic acids, phosphoric acids, etc.) having a structure in which an alkylene oxide is added, and mixtures thereof.

The above polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, 1,3- and
Dihydric alcohols such as 1,4-butanediol, 1,6-hexanediol, alkylene glycols such as neopentyl glycol, and diols having a cyclic group (for example, those described in Japanese Patent Publication No. 45-1474); Trihydric alcohols such as glycerin, trimethylolpropane, trimethylolethane, hexanetriol, and triethanolamine; tetrahydric alcohols such as pentaerythritol, methylglycoside, diglycerin; and sugar alcohols with higher functional groups such as adonitol, arabitol, Pentitol, such as xylitol,
Hexitols such as sorbitol, mannitol, iditol, talitol, dulcitol; sugars, for example
Monosaccharides such as glucose, mannose, fructose and sorbose; oligosaccharides such as sucrose, crehalose, lactose and raffinose; glycosides such as polyols (eg glycols such as ethylene glycol and propylene glycol, glycerin, trimethylolpropane and hexanetriol). Alkane polyol)
Glucoside; Poly (alkane polyol) Polyglycerin such as triglycerin and tetraglycerin. And polypentaerythritol such as dipentaerythritol and tripentaerythritol; and cycloalkane polyols such as tetrakis (hydroxymethyl) cyclohexanol.

Examples of the polyphenols include monocyclic polyphenols such as pyrogallol, hydroquinone, and phloroglucin; bisphenols such as bisphenol A and bisphenol sulfone; condensates of phenol and formaldehyde (novolak), for example, described in US Pat. No. 3,265,641. Examples include polyphenols.

Also, as amines, ammonia; mono-, di-, and tri-ethanolamine, isopropanolamine,
Alkanolamines such as aminoethylethanolamine; C1-C20 alkylamines; C2-C6 alkylenediamines such as ethylenediamine, propylenediamine,
Hexamethylenediamine, polyalkylenepolyamines Aliphatic amines such as diethylenetriamine, triethylenetetramine; aniline, phenylenediamine, diaminotoluene, xylylenediamine, methylenedianiline, diphenyletherdiamine, other aromatic amines; isophoronediamine, cyclohexene Alicyclic amines such as cilendiamine and dicyclohexylmethanediamine; aminoethylpiperazine, and other heterocyclic amines described in JP-B-55-21044.

Two or more kinds of these active hydrogen atom-containing compounds may be used in combination. Of these, polyhydric alcohols are preferable.

Examples of the alkylene oxide added to the active hydrogen atom-containing compound include ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-,
1,3-, 1,4-, 2,3-butylene oxide, styrene oxide and the like, and a combination of two or more of these (block and / or random addition) can be mentioned.

Among the polyether polyols (i), those having a polyoxypropylene chain and those having a polyoxypropylene chain and a polyoxyethylene chain (EO content of 25% by weight or less) are preferable.

As the above polyether polyol, propylene oxide (hereinafter abbreviated as PO) is added to the above active hydrogen atom-containing compound.
And PO and other alkylene oxides (hereinafter abbreviated as AO) were added in the order of (1) PO-AO (chipped), (2) PO-AO-PO-AO. Block addition products such as (balanced), (3) AO-PO-AO added in order, (4) PO-AO-PO added (active secondary), etc .; (5) Random adducts of mixed addition of PO and AO; and (6) those added in the order described in JP-A-57-209920, (7)
Examples thereof include random / block addition products such as those added in the order described in JP-A-53-13700. You may use these together.

The hydroxyl value (average) of the polyether polyol (i) is
Usually 200 or less, preferably 15 to 100, particularly preferably 20
~ 70. If it exceeds 200, foaming is difficult.

The molecular weight of the polyether polyol (i) is usually 2000-
It is 30,000 or more, preferably 2500 to 10000.
If the molecular weight is less than 2000, foaming is difficult. When it exceeds 30,000, the viscosity of the obtained polymer polyether increases. In the present invention, the amount of the ethylenically unsaturated monomer (ii) used in the production of the polymer polyol is 100 parts in total of the polyether polyols (i) and (ii) (parts by weight, the same applies hereinafter).
The amount is usually 1 to 80 parts, preferably 5 to 60 parts. (I
When i) exceeds 80 parts, the polyether layer and the polymer layer are separated. If it is less than 1 part, the hardness is not high.

The polymer polyol can be produced by an ordinary method for producing a polymer polyol. For example, a method of polymerizing an ethylenically unsaturated monomer (ii) in a polyether polyol (i) in the presence of a polymerization initiator (radical generator, etc.) (US Pat. No. 3,383,351), JP-B-39-24737. (Japanese Patent Publication No. 47-47999, Japanese Patent Laid-Open No. 50-15894, etc.) and (ii)
There is a method of graft-polymerizing the polymer obtained by preliminarily polymerizing (i) and (i) in the presence of a radical generator, and the former method is preferable.

A polymerization initiator is usually used for these polymerizations. The polymerization initiator is of a type that generates free radicals to initiate polymerization, such as 2,2′-azobisisobutyronitrile (A
IBN), 2,2'-azobis- (2,4-dimethylvaleronitrile) (AVN) and other azo compounds; dibenzoyl peroxide, dicumyl peroxide, bis (4-t-butylcyclohexyl) peroxydicarbonate , Benzoyl peroxide, lauroyl peroxide, and other peroxides, and peroxides other than those described above in Japanese Patent Application No. 59-199160, or persulfates, perborates, persuccinic acids, and the like can be used. Of these, AIBN and bis (4-t-butylcyclohexyl) peroxydicarbonate are preferred.

The amount of the polymerization initiator used is usually 0.1 to 15%, preferably 0.2 to 10% based on the weight of the ethylenically unsaturated monomer.

The above-mentioned polymerization reaction can be carried out without a solvent, but it can also be carried out in the presence of an organic solvent (particularly when the polymer concentration is high). Examples of the organic solvent include benzene, toluene, xylene, acetonitrile, ethyl acetate, hexane, heptane, dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, isopropyl alcohol, n-butanol and the like.

If necessary, a chain transfer agent such as alkyl mercaptans (dodecyl mercaptan, mercaptoethanol, etc.), alcohols (isopropyl alcohol), methanol, 2-butanol, allyl alcohol, etc.,
Polymerization can be carried out in the presence of halogenated hydrocarbons (carbon tetrachloride, carbon tetrabromide, chloroform, etc.) and enol ethers described in JP-A-55-31880.

The polymerization can be carried out batchwise or continuously. The polymerization reaction can be carried out at a temperature not lower than the decomposition temperature of the polymerization initiator, usually 60 to 180 ° C., preferably 90 to 160 ° C., particularly preferably 100 to 150 ° C., and can be carried out under atmospheric pressure or under pressure, or even under reduced pressure. You can

After the completion of the polymerization reaction, the modified polyol obtained can be used as it is for the production of polyurethane without any post-treatment, but after the completion of the reaction, impurities such as organic solvents, decomposition products of polymerization initiators and unreacted monomers are commonly used. It is desirable to remove by means.

The hydroxyl value of the polymer polyol in the present invention is usually 5 to
It is 100, preferably 7 to 80, more preferably 10 to 60.

In the method for producing a polyurethane of the present invention, the polymer polyol can be used in combination with other active hydrogen atom-containing compound, if necessary. In addition to the polymer polyol, the other active hydrogen atom-containing compound optionally used may be a polymer polyol and / or a low molecular weight active hydrogen atom-containing compound which are commonly used in polyurethane production.

Other high molecular weight polyols that may be optionally used include
Polyether polyol and polyester polyol can be used. Examples of the polyether polyol include those described as the starting material polyether polyol (i) for the polymer polyol.

Examples of the polyester polyol include the polyhydric alcohols (ethylene glycol, diethylene glycol, propylene glycol, 1,3- or 1,4-butanediol, 1,6
-Hexanediol, neopentyl glycol, etc. 2
A polyhydric alcohol or a mixture thereof with a trihydric or higher alcohol such as glycerin or trimethylolpropane), a polycarboxylic acid or an anhydride thereof, an ester-forming derivative such as a lower ester (eg adipic acid, sebacic acid, anhydrous By reacting (condensing) maleic acid, phthalic anhydride, dimethyl terephthalate, etc.) or its anhydride and alkyleonoxide (EO, PO, etc.), or by ring-opening polymerization of a lactone (ε-caprolactone, etc.) You can get what you get.

In addition, polybutadiene polyols, hydroxyl group-containing vinyl polymers (acrylic polyols) such as JP-A-58-57413.
Nos. 55741 and natural oil-based polyols such as castor oil and modified polyols can also be used.

These polyols usually have 2 to 8 hydroxyl groups and 200 to 40
OH equivalent of 00, preferably 3-8 hydroxyl groups and 400-3,000
Has an OH equivalent of.

Of these, polyether polyols are preferred.

The low molecular weight active hydrogen atom-containing compound used as necessary has at least 2 (preferably 2 to 3 and particularly preferably 2) active hydrogen atoms (hydroxyl group, amino group, mercapto group, etc., preferably hydroxyl group). Having a molecular weight of 50
Compounds of 0 or less (preferably 60 to 400) such as low molecular weight polyols and amino alcohols can be used.
As the low molecular weight polyol, dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, neopentyl glycol and hexanediol; glycerin, trimethylolpropane, pentaerythritol, diglycerin, α -Trihydric or higher polyhydric alcohols such as methyl glucoside, sorbitol, xylitol, mannitol, dipentaerythritol, glucose, fructose, sucrose; low molecular weight (eg molecular weight 200-40)
0) polyhydric alcohol AO adducts (polyethylene glycol, polypropylene glycol, etc.); low-molecular diols having a cyclic group [for example, those described in JP-B-45-1474 (such as propylene oxide adducts of bisphenol A)]; Low molecular weight polyols containing tertiary or quaternary nitrogen atoms [for example, those described in JP-A-54-130699 (N
-N-alkyl dialkanolamines such as methyldiethanolamine, N-butyldiethanolamine and the like and their quaternary compounds); trialkanolamines (triethanolamine, tripropanolamine etc.)]; thiodiethylene glycol and the like. Amino alcohols include mono- or di-alkanolamines such as monoethanolamine, diethanolamine,
Monopropanolamine etc.) can be mentioned. Of these, preferred are low molecular weight polyols (especially diols), specifically ethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol and mixtures of two or more thereof. Is.

The amount of the polymer polyol in the whole active hydrogen atom-containing compound is usually 5% by weight or more, preferably 10 to 80% by weight.
If (a) is less than 5% by weight, the foam hardness is not good.

The amount of the other polymer polyol is usually 0 to 95% by weight, preferably 0 to 80% by weight. 95% by weight of high molecular weight polyol
If it exceeds, the foam hardness is not high.

The amount of the low molecular weight active hydrogen-containing compound is usually 0 to 30% by weight, preferably 0 to 10% by weight. If the amount of the low molecular weight active hydrogen atom-containing compound exceeds 30% by weight, the exothermic temperature during the reaction becomes high and scorch is generated.

As the organic polyisocyanate used in the present invention, those conventionally used for polyurethane production can be used. Examples of such polyisocyanates include aromatic polyisocyanates having 6 to 20 carbon atoms (excluding carbons in the NCO group) (for example, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4'- and /
Or 4,4'-diphenylmethane diisocyanate (MD
I), crude MDI [crude diaminophenylmethane {condensation product of formaldehyde and aromatic amine (aniline) or mixture thereof: product: mixture of diaminodiphenylmethane and a small amount (for example, 5 to 20% by weight) of trifunctional or more polyamines } Phosgene compound: polyallyl polyisocyanate (PAPI) and the like]; aliphatic polyisocyanate having 2 to 18 carbon atoms (eg hexamethylene diisocyanate,
Lysine diisocyanate): alicyclic polyisocyanate having 4 to 15 carbon atoms (eg isophorone diisocyanate, dicyclohexylmethane diisocyanate); araliphatic polyisocyanate having 8 to 15 carbon atoms (eg xylylene diisocyanate); and these polyisocyanates Modified products (urethane group, carbodiimide group, allophanate group, urea group, buret group,
Uretdione group, uretonimine group, isocyanurate group, oxazolidone group-containing modified product, etc.);
Other polyisocyanates described in JP-A-59-199160; and mixtures of two or more thereof. Of these, commercially readily available polyisocyanates, such as 2,4- and / or 2,6-TDI, and mixtures of these isomers, crude TDI, 4,4'- and 2,
Contains 4'-MDI and mixtures of these isomers, PAPI also called crude MDI, and urethane group, carbodiimide group, allophanate group, urea group, buret group, isocyanurate group derived from these polyisocyanates Modified polyisocyanates.

In the present invention, the isocyanate index [NCO / active hydrogen atom-containing group equivalent ratio × 100] during polyurethane production
Is usually 80 to 140, preferably 85 to 120, particularly preferably
95-115. It is also possible to introduce the polyisocyanurate into the polyurethane with an isocyanate index much higher than the above range (eg 300 to 1,000 or more).

In the present invention, in order to accelerate the reaction, catalysts usually used in polyurethane reactions [for example, amine-based catalysts (tertiary amines such as triethyleneamine and N-ethylmorpholine), tin-based catalysts (stannous octylate, dibutyl). Tindilaurate), and other metal catalysts (such as lead octylate)] can be used. The amount of catalyst is used, for example, from about 0.001 to about 5%, based on the weight of the reaction mixture.

Further, in the present invention, a foaming agent (for example, methylene chloride, monofluorotrichloromethane, water, etc.) can be optionally used in the production of polyurethane. The amount of blowing agent used can vary depending on the desired density of the polyurethane.

A foam stabilizer can be used as at least a part of other additives which can be used as necessary in the present invention. Examples of the foam stabilizer include a silicone surfactant (polysiloxane-polyoxyalkylene copolymer).

Other additives that can be used in the present invention include flame retardants, reaction retarders, colorants, internal mold release agents, antioxidants, antioxidants, plasticizers, bactericides, carbon black and other known fillers. Examples include additives.

The polyurethane can be produced by a usual method, and can be performed by a known method such as a one-shot method, a semi-prepolymer method or a prepolymer method. A commonly used manufacturing apparatus can be used for polyurethane production. In the case of using no solvent, an apparatus such as a kneader or an extruder can be used. A variety of non-foamed or foamed polyurethanes can be produced in closed or open molds. Polyurethane is usually produced by mixing and reacting raw materials using a low-pressure or high-pressure mechanical device. Furthermore, before and after mixing the raw materials (particularly before mixing the raw materials), a gas such as dissolved air in the raw materials or air mixed during mixing can be removed by a vacuum method to produce polyurethane. The method of the present invention is useful for making flexible mold foams and slab foams. It can also be used for molding by the RIM (reaction injection molding) method.

[Examples] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Parts and% represent parts by weight and% by weight, respectively.

The compositions of the raw materials used in Examples and Comparative Examples are as follows.

(1) Polyol A: A polyol having a hydroxyl value of 34 in which PO is added to glycerin.

(2) Polyol B: hydroxyl value obtained by adding PO to glycerin and sucrose (30/70% by weight), and then adding EO.
The polyol.EO additive is 10% by weight.

(3) Polyol C: PO is added to glycerin, and then EO
A polyol having a hydroxyl value of 45 to which is added PO, and then PO. The EO additive is 4% by weight.

(4) Polyol D: A polyol having a hydroxyl value of 55 in which PO is added to glycerin.

(5) α-Olefin: D124 (weight ratio of C12: C14 = 56: 44) [manufactured by Mitsubishi Kasei Co., Ltd.] (6) Polyisocyanate: TDI-80 [manufactured by Nippon Polyurethane Industry Co., Ltd.] (7) Catalyst: DABCO33LV (33% dipropylene glycol solution of triethynediamine) Neostan U-28 (tin catalyst)
[Nitto Kasei Co., Ltd.] (8) Foam stabilizer: L-520 (polyether siloxane polymer)
[Nippon Unicar Co., Ltd.] Reference Examples 1 to 4 Polymer polyols I to IV were synthesized under the conditions shown in Table 1.

Reference Examples 5 to 8 Polymer polyols V to VIII were synthesized under the conditions shown in Table 2.

Reference Examples 9 to 12 Polymer polyols IX to XII were synthesized under the conditions shown in Table 3.

Comparative Example 1 and Examples 1 to 2 Polyurethanes were produced by the foaming formulations shown in Table 4 by using some of the polymer polyols prepared by the synthetic methods shown in Tables 1 to 3.

The physical properties are measured as follows.

Density (kg / m ³ ): JIS K630 1,25% ILD (kg / 314 cm ² ): JIS K6
382, Tensile strength (kg / cm ² ): JIS K6301, Tear strength (kg / c
m): JIS K6301, cutting elongation (%): JIS K6301, rebound resilience (%): JIS K6382, compression set (%): JIS K6382 [Effect of the invention] The polymer polyol composition of the present invention is a conventional one. In the method for producing a polyurethane of the present invention, which has a lower viscosity than the above, a foam having high hardness can be produced by using a polymer polyol composition (modified polyol) having such a low viscosity. In the molded foam, the viscosity of the polyether is lowered, so that the mold flow is improved and the moldability of the foam can be improved.

Because of the above effects, the polyurethane foam obtained according to the present invention is extremely useful in applications such as interior furnishings for automobiles and interior furnishings of furniture.

Claims (1)

[Claims] 1. A method for producing a polyurethane foam by reacting a polyisocyanate and an active hydrogen atom-containing compound in the presence of a foaming agent and, if necessary, a catalyst and other additives, wherein the active hydrogen atom-containing compound is: 0.5 to 50% by weight of carbon number 8 in polyether polyol (i)
Of .about.20 .alpha.-olefin and 95.5 to 50% by weight of another ethylenically unsaturated monomer (ii), which is a polymer foam obtained by polymerizing 10 to 80% by weight of a polyurethane foam. Manufacturing method.