JPH0120165B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a thermoplastic polyurethane resin. More specifically, the present invention relates to a method for producing a thermoplastic polyurethane resin that is soluble in an acyclic ketone solvent and/or a ketone-aromatic hydrocarbon mixed solvent and has a high Young's modulus. Thermoplastic polyurethane resin (hereinafter simply TPU)
There is a field in which it is used by dissolving it in a solvent. In other words, coating is performed using various methods using TPU solution alone or mixed with other resins, inorganic materials, etc. In this case, it is preferable to be able to freely select the solvent depending on the application, combination of materials, coating conditions, etc. . However, conventional TPU is insoluble in solvents or dimethylformamide (amide type),
Dimethyl sulfoxide (sulfoxide type),
Most of them were soluble only in solvents such as tetrahydrofuran (cyclic ether type) and cyclohexanone (cyclic ketone type). On the other hand, in the paint field, acyclic ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and aromatic hydrocarbon solvents such as toluene are used to improve workability and
It is preferred because of its low cost, but it is not the same as the conventional
TPUs soluble in these solvents were limited to extremely low modulus. Therefore, we investigated various methods for manufacturing TPU that is easily soluble in acyclic ketone solvents and/or ketone-aromatic hydrocarbon mixed solvents and has a higher Young's modulus than conventional solvent-soluble TPUs. As a result, the present invention was achieved. That is, the present invention provides a method for producing a thermoplastic polyurethane resin by reacting a high molecular diol (A) with an average molecular weight of 500 to 5000, a low molecular diol (B) with an average molecular weight of 500 or less, and an organic diisocyanate (C). 1) Using an organic solvent, (2) The weight of A is 1 to 30 of the total weight of A, B, and C.
(3) All or part of B is an alkylene oxide addition polymer of bisphenol A, (4) The ratio of the total number of hydroxyl groups in A and B to the number of isocyanate groups in C is 1:1.0 to 1. :1.1, and (5) A method for producing a thermoplastic polyurethane resin, characterized by using a reaction terminator having one or more active hydrogen groups. The solvents used in the present invention include one or more of amide, sulfoxide, cyclic ether, cyclic ketone, and acyclic ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, as well as the above solvents and ethyl acetate. , a mixed solvent with an ester solvent such as butyl acetate, an aromatic hydrocarbon solvent such as benzene, toluene, or xylene, or a chlorine solvent such as methylene chloride or perchlorethylene. The polymer diol (A) used in the present invention is a known polyether diol, polyester diol,
Polycarbonate diol, etc. Examples of polyether diols include water, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol,
1,3- or 1,4-butylene glycol,
It is obtained by adding one or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide, etc. to 1,6-hexamethylene glycol or the like. Examples of polyester diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol,
One or more of 1,3- or 1,4-butylene glycol, neopentyl glycol, 1,6-hexamethylene glycol, decamethylene glycol, and malonic acid, maleic acid, succinic acid,
Polyester diol from one or more of adipic acid, glutaric acid, pimelic acid, sebacic acid, oxalic acid, phthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid, etc., or propiolactone, butyrolactone, caprolactone, etc. It is a diol obtained by ring-opening polymerization of a cyclic ester. Polycarbonate diol is a compound represented by the general formula H[-O-R-OCO]- _o ROH (n≧1), where R is glycol or 2
phenols such as trimethylene glycol, diethylene glycol, 1,3- or 1,4
-Butylene glycol, 1,6-hexamethylene glycol, decamethylene glycol, p-xylylene glycol, bisphenol A [2,2-
bis(4'-hydroxyphenyl)propane], bisphenol F (4,4'-dihydroxydiphenylmethane), and the like. 1,2-polybutadiene glycol, 1,4-polybutadiene glycol, etc. are also used as the polymer diol of the present invention. Two or more of these various polymer diols may be used as a mixture. The polymer diol (A) used in the present invention has an average molecular weight of 500 to 5,000. Among the low molecular diols (B) with an average molecular weight of 500 or less used in the present invention, the alkylene oxide addition polymer of bisphenol A is
It is obtained by adding one or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, etc. to Low molecular weight diol used in combination with alkylene oxide adduct of bisphenol A in the present invention
(B) is a branched aliphatic low molecular diol such as propylene glycol, neopentyl glycol, 1,
3-butylene glycol, 2-ethyl-1,3-
Hexanediol, 2,2,4-trimethyl-
1,3-pentanediol, 2,2,4- or 2,4,4-trimethyl-1,6-hexanediol, etc., and linear aliphatic low molecular weight diols such as ethylene glycol, trimethylene glycol, 1, 4-butanediol, 1,5-pentanediol, 1,6-hexamethylene glycol,
decamethylene glycol, etc.; low molecular weight diols having an aromatic ring and alcoholic hydroxyl group, such as p-xylylene glycol;
These include alicyclic low-molecular-weight diols, such as 1,4-cyclohexanediol, or methyldiethanolamine, and a mixture of two or more of these may also be used. High molecular diol (A) and low molecular diol of the present invention
(B), organic diisocyanate C, (1) The weight of A is 1 to 1 of the total weight of A, B, and C.
(2) The ratio of the total number of hydroxyl groups in A and B to the number of isocyanate groups in C is 1:1.0 to 1:1.1. In (1) above, if A is used in an amount less than 1% or more than 30%, physical properties will deteriorate. In addition, in (2) above, in order to obtain TPU with good solubility in a solvent, it is preferable to carry out chain extension with an excess of isocyanate groups and to terminate the reaction with a reaction terminator described below. However, if the ratio exceeds 1:1.1 and there are many isocyanate groups, chain extension will be insufficient, the molecular weight of the polymer will not increase, and the physical properties will deteriorate. In the present invention, a conventionally known urethanization catalyst is used as necessary at any stage of the reaction. The reaction terminator used in the present invention is isopropanol, n-butanol, sec-butanol, t
- Monoalcohols such as butanol, glycols such as ethylene glycol and propylene glycol, triols such as glycerin and trimethylolpropane, amines such as dimethylamine, ethylpropylamine, and dibutylamine, and alkanols such as diethanolamine and triethanolamine. Amines, oximes such as acetoxime and methyl ethyl ketoxime, γ-butyrolactam, ε
- Lactams such as caprolactam, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, γ - Silane coupling agents such as mercaptopropyltrimethoxysilane. The amount of reaction terminator used is, per 1 mole of C,
It is 0.01-0.2 mole. In the present invention, additives such as antioxidants, ultraviolet absorbers, and carbodiimides are used as necessary. To outline the production of TPU of the present invention, a polymer diol (A), an organic diisocyanate (C), and if necessary a urethanization catalyst are mixed in a solvent at a solid content of 20 to 80% at 50 to 90°C for 1 hour. Allow to react for ~3hr. To the resulting NCO-terminated prepolymer solution, add 50 to
The low-molecular-weight diol (B) is reacted at 90°C either all at once or by dividing the charge. As the viscosity of the reaction solution increases, a solvent and a catalyst are added as necessary to carry out the reaction. When a predetermined viscosity is reached, a reaction terminator is added to stop the reaction. (The above conditions are normal conditions.
It is not necessarily limited to this. ) The resulting TPU solution preferably has a solids content of 10-40%, and preferably has a viscosity at 25° C. of 1000 centipoise or higher for an approximately 30% solution. If the viscosity is lower than this, good physical properties cannot be obtained. The TPU in the present invention is easily soluble in an acyclic ketone solvent and/or a ketone (meaning a cyclic and acyclic ketone in the present invention)-aromatic hydrocarbon mixed solvent, and moreover, compared to conventional solvent-soluble types. It has a high Young's modulus. In the present invention, TPU can be used in the form of a solution or in the form from which the solvent has been removed by a conventional method, and can be used in resins, films, various coatings, impregnation agents, adhesives, paints, etc.
Used in binders, magnetic tape binders, etc. Next, the present invention will be specifically explained with reference to Examples. Note that parts indicate parts by weight. Example 1 After replacing the reactor with a stirrer and a reflux condenser with nitrogen gas, methyl isobutyl ketone (hereinafter referred to as MIBK
It is abbreviated as ) and then add polytetramethylene ether glycol (average molecular weight 1000).
100 parts of diphenylmethane-4,4'-diisocyanate and 0.05 parts of dibutyltin dilaurate were added and reacted at 80°C for 2 hours to obtain an NCO group-terminated prepolymer solution. A propylene oxide adduct of bisphenol A (OH group 316 mgKOH/g, average molecular weight 355) was added to this prepolymer solution.
221.5 parts and 500 parts of MIBK were added and reacted at 80°C. After the viscosity of the solution reached approximately 50,000 centipoise at 80°C, 9.0 parts of isopropanol and 200 parts of MIBK were added to stop the reaction. The obtained TPU solution is
Solid content 30.7%, viscosity 16000 centipoise (25℃)
The resin obtained from this solution has Ys (stress at yield) of 570 Kg/cm ² , elongation at yield of 4.0%, and Young's modulus of
It was 2.03×10 ⁴ Kg/cm ² . Ys, elongation at yield, and Young's modulus were measured on a rectangular sample with a width of 5 mm at a distance between gauge lines of 50 mm and a tensile rate of 5 mm/min. Example 2 The resin of Example 2 was produced in the same manner as in Example 1. The composition and properties of the resin are shown in Table 1. Comparative Examples 1 to 2 Comparative Examples 1 and 2 were prepared in the same manner as in Example 1.
The company was engaged in the production of resins. The composition and properties of the resin are shown in Table 1. 【table】

Claims (1)

[Claims] 1. A polymeric diol (A) having an average molecular weight of 500 to 5000,
In a method for producing a thermoplastic polyurethane resin by reacting a low molecular diol (B) with an average molecular weight of 500 or less and an organic diisocyanate (C), (1) an organic solvent is used, (2) the weight of A is equal to that of A, B, and 1 to 30 of the total weight of C
(3) All or part of B is an alkylene oxide addition polymer of bisphenol A, (4) The ratio of the total number of hydroxyl groups in A and B to the number of isocyanate groups in C is 1:1.0 to 1. : 1.1, and (5) A method for producing a thermoplastic polyurethane resin, characterized by using a reaction terminator having one or more active hydrogen groups.