JPH0372093B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyurethane. Conventional methods for producing polyurethane include producing urethane resins using either or a combination of polyalkylene ether glycols such as polytetramethylene ether glycol and polypropylene ether glycol, or polyester glycols as polymeric diols. However, the resin obtained by this manufacturing method does not have sufficient wet film forming properties or has insufficient hydrolysis resistance when making sheet materials, for example. The present inventors have conducted intensive studies to find a method for producing polyurethane that does not have such problems, and have finally arrived at the present invention. That is, the present invention provides organic diisocyanate (A),
The weight ratio of oxyethylene units and oxytetramethylene units is 5:95 to 70:30, and the average molecular weight is 500.
~5000 ethylene oxide/tetrahydrofuran copolymerized ether diol (b ₁ ) [hereinafter referred to as polyethylene/tetramethylene ether diol (b ₁ )], a low molecular diol and a molecular weight
A condensation polyester of a diol selected from the group consisting of polyalkylene ether glycols of 1000 or less and a dicarboxylic acid selected from the group consisting of aliphatic dicarboxylic acids or aromatic dicarboxylic acids, or a polyester obtained by ring-opening polymerization of lactone, with an average molecular weight Consisting of 500 to 5000 polyester diol (b ₂ ), the weight ratio of (b ₁ ):(b ₂ ) is 90:
This is a method for producing polyurethane, characterized by reacting a polymer diol (B) with a ratio of 10 to 10:90 and, if necessary, a chain extender (C). In the polyethylene/tetramethylene ether diol (b ₁ ) used in the present invention, the weight ratio of oxyethylene groups to oxytetramethylene groups is usually 5:95 to 70:30, preferably 10:90 to 50:50. . When the proportion of oxytetramethylene groups exceeds the above range, wet film forming properties become poor, and when the proportion of oxyethylene groups exceeds the above range,
Wet film forming properties and polyurethane hydrolysis resistance become poor. (b ₁ ) includes block copolymers and random copolymers of tetrahydrofuran (hereinafter abbreviated as THF) and ethylene oxide (hereinafter abbreviated as EO). (b ₁ ) can be produced by various methods. For example, block copolymers are polytetramethylene ether glycol (hereinafter referred to as polytetramethylene ether glycol).
It can be obtained by adding EO to (abbreviated as PTMG) or by adding THF to polyoxyethylene glycol. The above-mentioned PTMG can be a conventional one, such as the PTMG described in Japanese Unexamined Patent Publication No. 58-29816. The method of adding EO may be a method of adding under pressure in the presence of a usual alkaline catalyst (KOH, NaOH, etc.). Further, the THF addition may be carried out in the presence of a catalyst (such as a Lewis acid). Random copolymers can also be obtained by reacting THF and EO in the presence of an initiator (water, ethylene glycol, 1,4-butanediol, etc.) and a catalyst (Lewis acid, etc.). The average molecular weight of (b ₁ ) is usually 500 to 5000, preferably 1000 to 3000. The polyester diol (b ₂ ) used in the present invention is, for example, a condensed polyester diol obtained by reacting a low molecular diol or a polyalkylene ether glycol with a molecular weight of 1000 or less with a dicarboxylic acid, or a condensed polyester diol obtained by ring-opening polymerization of a lactone. Examples include polyester diol. The above-mentioned low molecular diols include ethylene glycol, propylene glycol, 1.3-butanediol, 1.4-butanediol, 1.6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, bis(hydroxymethyl)cyclohexane, bis(hydroxyethyl)benzene. and mixtures of two or more of these. Polyalkylene ether glycols with a molecular weight of 1000 or less include PTMG,
Examples include polypropylene ether glycol, polyethylene ether glycol, and mixtures of two or more thereof. Examples of dicarboxylic acids include aliphatic dicarboxylic acids (succinic acid, adipic acid, azelaic acid, sebacic acid, etc.), aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, etc.), and mixtures of two or more of these. . The condensed polyester diol can be obtained by the same conventional method, in which a low molecular diol or a polyalkylene ether glycol with a molecular weight of 1000 or less and a dicarboxylic acid are reacted under normal reaction conditions so as to form terminal hydroxyl groups. Bye. Further, the method for obtaining polyester diol obtained by ring-opening polymerization of lactone may be the same as conventional methods, for example, by addition polymerizing a lactone (e.g., ε-caprolactone, etc.) to an initiator (e.g., glycols). Preferred among these polyester diols are polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyneopentyl adipate, polyethylene propylene adipate, polyethylene butylene adipate, polybutylene hexamethylene adipate, polydiethylene adipate, and poly(polytetramethylene ether). ) adipate, polyethylene azelate, polyethylene sebacate, polybutylene azelate,
It is a polycaprolactone diol obtained by ring-opening polymerization of polybutylene sebacate and ε-caprolactone. The average molecular weight of the polyester diol is usually 500-5000, preferably 1000-5000.
It is 3000. The weight ratio of (b ₁ ) and (b ₂ ) in the polymer diol (B) used in the present invention is usually 90:10 to 10:
90, preferably 80:20 to 20:80. If (b ₁ ) is more than the above range, the wet film forming properties of the polyurethane will be poor, while if (b ₂ ) is more than the above range, the hydrolysis resistance of the polyurethane will be poor. The average molecular weight of (B) is usually 500 to 5000, preferably 1000 to
It is 3000. The organic diisocyanates (A) used in the present invention include aromatic diisocyanates (44'-diphenylmethane diisocyanate, tolylene diisocyanate, etc.), araliphatic diisocyanates (xylylene diisocyanate, etc.), and aliphatic diisocyanates (hexamethylene diisocyanate, etc.). , lysine diisocyanate, etc.), and alicyclic diisocyanates (isophorone diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, etc.). For details, please refer to JP-A No. 53-42294.
It is stated in the No. Of these, in practical terms,
Aromatic diisocyanates are preferred, and 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI) is particularly preferred. Chain extenders (C) used as necessary in the present invention include those described in JP-A-53-42294, such as low molecular weight diols (ethylene glycol, propylene glycol, 1.4-butanediol, 1.6-
hexanediol, etc.), aliphatic diamines (e.g. ethylene diamine), cycloaliphatic diamines (e.g. isophorone diamine), aromatic diamines (e.g. 4,4′-diaminodiphenylmethane), araliphatic diamines (e.g. xylene diamine), alkanolamines (e.g. ethanolamine, etc.), hydrazine, dihydrazides (adipate dihydrazide, etc.), and mixtures of two or more of these. Preferred among these are low molecular weight glycols, and particularly preferred are ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and mixtures of two or more thereof.
The molar ratio of the polymeric diol (B) to the chain extender (C) is usually 1:0 to 10, preferably 1:2 to 5. (B) and
The average molecular weight of the diol combined with (C) is usually 300
~800. If the average molecular weight of the diol is larger than 800, the wet film forming properties of polyurethane will be poor, and if it is smaller than 300, the wet film forming property of polyurethane will be good, but a hard polyurethane will be obtained, and the bending resistance, especially at low temperatures will be poor. The bending resistance becomes poor. In producing polyurethane according to the production method of the present invention, organic diisocyanate (A), polymeric diol (B) and chain extender (C) used as necessary
The ratio of isocyanate group to active hydrogen-containing group is usually from 0.9 to 1.1:1 (equivalent ratio), preferably substantially 1. When the ratio is outside the above-mentioned normal range, it is difficult to produce polyurethane with a high degree of polymerization. The method for producing polyurethane may be any known method, and a one-shot method is particularly preferred, for example, a method in which the organic diisocyanate (A), the polymeric diol (B), and if necessary, the chain extender (C) are reacted simultaneously. The above production can be carried out in the presence or absence of a solvent inert to isocyanate groups. When carrying out the reaction in the presence of a solvent, suitable solvents include amide solvents [dimethylformamide (hereinafter referred to as
(abbreviated as DMF), dimethylacetamide, etc.], sulfoxide-based solvents (dimethyl sulfoxide (abbreviated as “DMF”),
DMSO, etc.], ether solvents (dioxane, tetrahydrofuran, etc.), ketone solvents (cyclohexanone, methyl ethyl ketone, etc.),
Examples include ester solvents (such as ethyl acetate), aromatic hydrocarbon solvents (such as toluene), and two or more of these solvents. Practically preferred are amide-based solvents and sulfoxide-based solvents, and particularly preferred are is DMF. In the production of urethane according to the present invention, the reaction temperature may be the same as that normally employed in the urethanization reaction in the industry, and when a solvent is used, it is usually 20 to 100°C. Yes, usually 20-220℃, preferably 150-200℃ if no solvent is used
It is. In order to accelerate the reaction, amine catalysts (triethylamine, N-ethylmorpholine, triethylenediamine, etc.) and tin-based catalysts (trimethyltin laurate, dibutyltin dilaurate, etc.) used in normal urethane reactions may be used. . If necessary, a polymerization terminator such as a monohydric alcohol (methanol, butanol,
cyclohexanol, etc.), monovalent amines (methylamine, butylamine, cyclohexylamine, etc.), etc. can also be used. The production of polyurethane in the present invention can be carried out using production equipment normally employed in the industry. Further, when a solvent is not used, a manufacturing device such as a kneader or an extruder can be used. It is practically preferable for the polyurethane produced in this manner to have a solution viscosity of 2,000 to 1,000,000 cps/20°C measured as a 30% by weight (solid content) DMF solution. The polyurethane obtained by the present invention is different from that of the conventional polyurethane.
It has the advantage of superior wet film formability compared to PTMG/polyester diol combination polyurethane. In addition, the bending resistance and hydrolysis resistance are
It has the characteristics of both polyurethanes, such as being as good as PTMG polyurethane, and having weather resistance and abrasion resistance as good as polyester diol polyurethane. From the above, the polyurethane obtained by the present invention can be used for sheet materials, artificial leather, synthetic leather (shoes,
Other microporous coatings (coverings, clothing, bags, furniture, car seats, etc.), vehicles for printing inks, binders for magnetic tapes, paints, adhesives,
It can also be used for elastomers. Regarding the manufacturing method of the sheet material, conventional wet processing methods, such as (a), (b), and
This can be done using methods (c) and (d). Liquids (nonsolvents) used in wet processing include water, ethylene glycol, glycerin, ethylene glycol monoethyl ether, hydroxyethyl acetate, and mixtures thereof. Preferred is water. As the coagulation solution, only the above-mentioned non-solvent may be used, or a mixed bath of this and a solvent (DMF, DMSO, etc.) may be used. Alternatively, a method of coagulating with water or steam, or a method of partially coagulating with water vapor and then immersing in a coagulation bath may be used. A non-solvent may be added to the elastomer solution and applied to the substrate as a colloidal dispersion and immersed in a coagulation bath. After wet processing, remove solvent and wash (water,
dried with methanol, etc.). Anionic, nonionic or cationic or amphoteric surfactants can also be used to promote solvent removal. Further, crosslinking treatment can also be carried out by the method described in British Patent No. 1168872. The obtained sheet material may be used for various purposes, either as it is or after being peeled off from the substrate (if release paper, glass plate, etc. is used). The obtained sheet material has excellent wet film formability and hydrolysis resistance. It also has excellent air permeability, and is also excellent in terms of hygroscopicity, texture, flexibility, and physical properties (tensile strength, elongation, abrasion resistance, bending resistance, etc.). Furthermore, the structure can be such that the surface is dense and has high strength, and the interior has excellent air permeability and flexibility. The present invention will be further explained below with reference to Examples.
The present invention is not limited to these. Production example 1 400 g (0.2 mol) of PTMG with a molecular weight of 2000 and 0.4 g (0.007 mol) of potassium hydroxide are placed in an autoclave with an internal volume of 1, and after uniformly mixing, EO106
g (2.4 mol) at a pressure of 5 Kg/cm ² and a temperature of 140-160°C.
The reaction was carried out while maintaining the After the reaction, about 500 g of alkali is neutralized, separated, and dehydrated.
An EO adduct of PTMG (block copolymer of THF and EO, EO content 20%) was obtained. This product was a white solid at 20°C and had a hydroxyl number of 45. Production example 2 280 g (0.2 mol) of PTMG with a molecular weight of 1400 and 0.3 g (0.005 mol) of potassium hydroxide in an internal volume of 1
Put it in an autoclave and mix it evenly.
EO124g (2.8mol) at a pressure of 5Kg/cm ³ and a temperature of 140-
The reaction was carried out while maintaining the temperature at 160°C. After the reaction, approximately 400g of
An EO adduct of PTMG (block copolymer of THF and EO, EO content 30%) was obtained. This product was a white solid at 20°C and had a hydroxyl number of 56. Production example 3 THF216g (3 moles) and ethylene glycol
9.3g (0.15mol) and _BF3・THF21g (0.15mol)
was placed in an autoclave with an internal volume of 1, and after uniformly mixing, 54 g (1.23 mol) of EO was placed at a pressure of 1 Kg/cm ² ,
The reaction was carried out while maintaining the temperature at 20-30°C. After the reaction,
After neutralizing the acidic catalyst, separating it, and dehydrating it, approximately
270 g THF/EO random copolymer (EO content
20%). This product was a colorless and transparent liquid at 20°C and had a hydroxyl number of 62. Production example 4 THF 216g (3 moles), water 2g and BF ₃ .
8.4 g (0.06 mol) of THF was placed in an autoclave having an internal volume of 1, and after uniformly mixing, 93 g (2.11 mol) of EO was reacted while maintaining the pressure at 1 Kg/cm ² and the temperature at 20-30°C. After the reaction, the acidic catalyst was neutralized, separated, and dehydrated to obtain about 300 g of a THF/EO random copolymer (EO content: 30%). This one is 20
It was a colorless and transparent liquid at ℃ and had a hydroxyl number of 56. Example 1 EO of PTMG with a molecular weight of 2500 obtained in Production Example 1
250 g (0.1 mol) of the adduct, 200 g (0.1 mol) of polybutylene adipate with a molecular weight of 200, and 30 g (0.48 mol) of ethylene glycol were placed in a colben in step 3, and 1615 g of DMF was added and dissolved uniformly. Add 204g (0.82 mol) of MDI, 60-70℃
I reacted with 8 hours after the start of the reaction, the viscosity was 80,000
A transparent homogeneous polyurethane solution at cps/20°C was obtained. Example 2 EO of PTMG with a molecular weight of 2000 obtained in Production Example 2
200 g (0.1 mol) of the adduct, 100 g (0.1 mol) of polyethylene adipate with a molecular weight of 1000, and 44 g (0.49 mol) of 1.4-butanediol were placed in a colben in step 3, and 1204 g of DMF was added and dissolved uniformly. Add 172g (0.69 mol) of MDI and 60-70℃
I reacted with 8 hours after the start of the reaction, the viscosity was 100,000
A transparent homogeneous polyurethane solution at cps/20°C was obtained. Example 3 180 g (0.1 mol) of the THF/EO random copolymer with a molecular weight of 1800 obtained in Production Example 3 and
2500 polybutylene adipate 250g (0.1 mol)
and 35.7 g (0.58 mol) of ethylene glycol
into a kolben, add 1540g of DMF,
After uniformly dissolving, 194 g (0.78 mol) of MDI was added and reacted at 60-70°C. 12 hours after the start of the reaction, a transparent and uniform polyurethane solution with a viscosity of 100,000 cps/20°C was obtained. Example 4 200 g (0.1 mol) of the THF/EO random copolymer with a molecular weight of 2000 obtained in Production Example 4 and
2000 polyethylene adipate 200g (0.1 mol)
and 93 g (1.03 mol) of 1.4-butanediol in 3
into a kolben, add 1631g of DMF,
After uniformly dissolving, 233 g (0.93 mol) of MDI was added and reacted at 60-70°C. Eleven hours after the start of the reaction, a transparent and uniform polyurethane solution with a viscosity of 90,000 cps/20°C was obtained. Comparative Example 1 200g (0.1 mol) of PTMG with a molecular weight of 2000 and 200g (0.1 mol) of polyethylene adipate with a molecular weight of 2000.
mol) and 1.4-butanediol 93g (1.03 mol)
and 1,631 g of DMF were added to it, and after uniformly dissolving it, 233 g of MDI (0.93 mol) was added.
was added and reacted at 60-70°C. Eight hours after the start of the reaction, a transparent and uniform polyurethane solution with a viscosity of 100,000 cps/20°C was obtained. Comparative Example 2 400 g (0.2 mol) of PTMG with a molecular weight of 2000 and 42.4 g (0.68 mol) of ethylene glycol were put into a colben in step 3, 1548 g of DMF was added, and after uniformly dissolving, 221.3 g (0.89 mol) of MDI was added. was added and reacted at 60-70°C. Ten hours after the start of the reaction, a transparent and uniform polyurethane solution with a viscosity of 100,000 cps/20°C was obtained. Comparative example 3 400g of polyethylene adipate with a molecular weight of 2000
(0.2 mol) and 49.4 g (0.55 mol) of 1.4-butanediol were put into a No. 3 colben, and 1486 g of
After adding DMF and dissolving it uniformly, MDI187.3g
(0.75 mol) was added and reacted at 60-70°C. Ten hours after the start of the reaction, a transparent and uniform polyurethane solution with a viscosity of 90,000 cps/20°C was obtained. Test Example 1: Evaluation of Wet Film Formability For 100 parts of the 20% DMF solution of the polyurethane solutions obtained in Examples 1 to 4 and Comparative Examples 1 to 3,
A 1% coagulation regulator (MDI modified product of polyether-modified silicone) was added to each layer and applied to a thickness of 1.0 mm on a polyester film, and immersed in a 20% DMF water bath adjusted to 20°C for 10 minutes. This porous sheet was then peeled off from the polyester film and further coated for 20-20 minutes.
After washing by soaking in warm water at 30℃ for 90 minutes,
It was dried with hot air at 100°C for 20 minutes. The appearance and properties of the obtained porous sheet were as shown in Table 1.

【table】

[Table] Test Example 2: Evaluation of hydrolysis resistance The porous sheet obtained above was heated at 70℃ and 95%RH.
It was left for two weeks in a constant temperature and humidity chamber adjusted to . We measured the tensile strength of the porous sheet before and after this test.
The retention rate was determined. The results were as shown in Table-2.

[Table] Tensile strength before hydrolysis resistance test The porous sheet obtained by the method of the present invention has excellent surface smoothness, a uniform microporous layer with no curling phenomenon, and high However, in the polyurethane solutions of Comparative Examples 1 to 3, those that yielded good porous sheets had poor hydrolysis resistance, and those that had good hydrolysis resistance did not yield good porous sheets. Therefore, it did not have both excellent wet film formability and hydrolysis resistance.

Claims (1)

[Scope of Claims] 1 Organic diisocyanate (A), the weight ratio of oxyethylene units and oxytetramethylene units is 5:95
~70:30, an ethylene oxide/tetrahydrofuran copolymerized ether diol (b ₁ ) with an average molecular weight of 500 to 5000, a diol selected from the group consisting of low molecular weight diols and polyalkylene ether glycols with a molecular weight of 1000 or less, and aliphatic A polyester obtained by ring-opening polymerization of condensation polyester or lactone with a dicarboxylic acid selected from the group consisting of dicarboxylic acids or aromatic dicarboxylic acids, consisting of polyester diol (b ₂ ) with an average molecular weight of 500 to 5000, (b ₁ ) :(b ₂ ) weight ratio is
A method for producing polyurethane, which comprises reacting a polymer diol (B) with a ratio of 90:10 to 10:90 and, if necessary, a chain extender (C). 2 The amount of (C) is 0 to 1 mole of polymer diol (B).
The manufacturing method according to claim 1, wherein the amount is 10 mol.