JPS60115616A - Production of thermoplastic polyurethane resin - Google Patents

Abstract

PURPOSE:To obtain the titled soluble in general-purpose organic solvents and useful as a coating agent, binder, adhesive, or the like, by reacting a long-chain diol with an organic diisocyanate and an ester group-containing diol. CONSTITUTION:A long-chain diol, an organic diisocyanate, and an ester group- containing diol, MW<500, as a short-chain diol are reacted together to obtain a thermoplastic polyurethane resin. Examples of said ester group-containing dils include esters of glycols with hydroxyl group-containing monocarboxylic acids (molar ratio of 1:1) and esrers of compounds containing three hydroxyl groups in the molecule with monocarboxylic acids (molar ratio of 1:1). In producing the resin, a reaction catalyst such as stannous octoate or dibutyltin dilaurate can be used.

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 soluble in general-purpose organic solvents useful as coating agents, various binders, adhesives, and the like.

Polyurethane resin has excellent physical properties such as toughness and abrasion resistance, which are unique to polyurethane resin, due to intermolecular hydrogen bonds formed by urethane bonds.

Increasing the urethane group concentration lowers the solubility in organic solvents. Conventional thermoplastic polyurethane resins are either insoluble in organic solvents, or dimethylformamide, N-methy/l/
Many of them are soluble only in highly polar, high-boiling solvents such as pyrrolidone, dimethylsulfamide, and cyclohexanone, and cyclic ethers such as tetrahydrofuran and dioxane.When using conventional thermoplastic polyurethane resins dissolved in organic solvents.

There are problems such as decreased workability and swelling or dissolution of the material to be coated.

In addition, even if the dissolved product is soluble in general-purpose organic solvents, if the dissolved product is stored for a long period of time, insoluble low-molecular-weight compounds will precipitate and the solution will become cloudy, causing many practical problems.For example, when used as a coating agent, When this happens, the smoothness of the coated surface is greatly impaired, and when used as ink or various binders, it may impede the dispersibility of pigments or cause agglomeration of pigments in uniformly dispersed ink paints. If an insoluble low-molecular compound migrates to the surface, or if a transparent adherend is adhered, the transparency may be reduced.

Furthermore, when conventional thermoplastic polyurethane resins are dissolved in organic solvents, the viscosity of the solution is high, and there are economic problems such as the need to use a large amount of solvent to achieve a viscosity suitable for coating work.

In view of the above circumstances, the present inventors developed a coating agent.

Can be widely used in inks, paints, adhesives, etc., has excellent solubility in general-purpose organic solvents, long-term solution stability, and low solution viscosity.
Furthermore, this is the result of extensive research into thermoplastic polyurethane resins that have excellent pigment dispersibility.

We have arrived at the present invention.

That is, the present invention relates to a method for producing a thermoplastic polyurethane resin by reacting a long chain diol, an organic diisocyanate, and a short chain diol.

This is a method for producing a thermoplastic polyurethane resin, characterized in that an ester group-containing diol having a molecular weight of less than 500 is used as the short chain diol.

In the present invention, since the thermoplastic polyurethane resin contains a diol having an ester mit of less than 500 molecular caps as a short chain diol, the solubility in a general-purpose 1fm solvent is improved, and the dissolved amount can be stored for a long time. Therefore, when the thermoplastic polyurethane resin of the present invention is used as a coating agent, ink, paint, or adhesive, the smoothness of the coating film, the dispersibility of pigments, etc. are excellent.

The thermoplastic polyurethane resin of the present invention has a long chain diopter
It is made from a diisocyanate and a short chain diol.

Examples of the long-chain di-ol used in the present invention include polyester di-p1 polyether diol with a molecular weight of 500 or more, polycarbonate di-μ, etc., but polyester di-
is desirable.

The carboxylic acid component of the polyester diol includes aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and 1,5-naphthalic acid.

Aromatic substances such as p-oxybenzoic acid and p-(hydroxyethoxy)benzoic acid! Examples include dicarboxylic acids, ring group carboxylic acids such as 1,4-cyclohexanedicarboxylic acid, aliphatic dicarboxylic acids such as succinic acid, adipic acid, azefinic acid, sebacic acid, and dodecanedicarboxylic acid.

In addition, as glycol components of polyester diol, ethylene glycol/I/, propylene glycol, 1
,3-propanedio-/I/,1,4-butanedio-/
L/, 1.5-pentanedio-/I/, 116-hexanedio-)v, neopentyl glycol, neopentyl glycol hydroxypivalate, diethylene glycol, dipropylene glycol-/I/12,2゜4-trimethyl- 1,3-bentanediol, V chlorohexane dimetatool, bispheno-)VA ethylene oxide and propylene oxide adducts, hydrogenated bispheno-/l/A ethylene oxide and propylene oxide adducts, polyethylene Glyco-μ,
Examples include polypropylene glycol and polytetramethylene glycol.

Polyester diols suitable for the purpose of the present invention include:
The glycol component is (A) neopentyl glycol, (B
) cyclohexane dimetatool and (C) the above (A)
, consists of an aliphatic glycol having 2 to 13 carbon atoms other than (B), and the carboxylic acid component is (D) isophthalic acid, (
E) orthophthalic acid and/or p-oxybenzoic acid, and (F) dicarboxylic acids other than the above (D) and (E) are preferable, and in particular, the molar ratio of the above (A) to (F) components is as follows. Those within the range of formula are most desirable.

90/10〉(A)/(B)〉20/8040/100
〉(C)/(A)+(B) 10(C)〉099/1 〉■
) ICE)>5015040/100 〉(F)/ω)
+ (E) + (F) Raw materials for polyester diol other than the above include dicarboxylic acids containing sulfonic acid metal bases such as 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, and sodium sulfoterephthalic acid; Powder-containing dicarboxylic acid and succinic acid represented by the following general formulas [■] and [■].

Aliphatic dicarboxylic acids such as adipine, sebacic acid, and dodacanedionic acid can be mentioned.

(In the formula, +RI is a monovalent ester-forming functional group.

R2+R8 are the same or different groups, and include a monovalent hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, and 1
selected from the group consisting of valent ester-forming functional groups. A
indicates a divalent or trivalent residual residue. Further, nl represents 1 or 2*nzrns each represents an integer of 0 to 4. ) (In the formula, R4 is a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms that may contain an ester-forming functional group, or M2゜R5 is a divalent or trivalent hydrocarbon group having 1 to 6 carbon atoms. .RaFi hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms that may contain a hydroxyl group, or Ms; Mt + M2
, Ms is an alkali metal atom. m is O or 1. J is 1
or an integer of 2. ) A polyester diol containing a sulfonic acid metal base, a polyester diol obtained by using a phosphorus-containing compound represented by the general formula (I) or (II) as at least one component of the raw material, is used as a component of the raw material of a thermoplastic polyurethane resin. In this case, it is effective in greatly overcoming the disadvantage of low dispersibility of inorganic pigments and fillers found in conventional thermoplastic polyurethane resins.

Other examples of polyester diols include lactone-based polyester di-/L's obtained by ring-opening polymerization of lactones such as ε-caprolactone.

Examples of polyether diols include polyalkylene glycols such as polyethylene glycol, polypropylene glycol/L/, and polytetramethylene glycol.

As polycarbonate diol, the general formula H+O-R
It is a long chain diol represented by -OCO-)nROH, and R is diethylene glyco-/9.116-hexanedio-/L/1 bispheno-/I/A.

The long chain di-/l' used in the present invention has a molecular weight of 500
~5,000 is preferably used.

When the molecular weight is less than 500, the urethane base degree becomes large,
The flexibility and solvent solubility of the resin decrease. Furthermore, if the number of needles per molecule exceeds 5,000, the urethane group concentration becomes low F, and the toughness, abrasion resistance, etc., which are unique to polyurethane resins, decrease.

The residual diisocyanate used in the present invention is 2.4-
) lylene diisocyanate, 2,6-dolylene diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, 3,3'-dimethoxy-4,
4'-biphenylene diisocyanate, 2,4-naphthalene diisocyanate, 3,3'-dimethy A'-C4
'-biphenylene diisocyanate, 4.4'-diphenylene diisocyanate), 4.4'-diisocyanate diphenylnyxylylene diisocyanate, m-
Examples include xylylene diisocyanate, 1,3-diisocyanatemethylcyclohexane, 1,4-diisocyanatemethylcyclohexane, 4,4'-diisocyanatedicyclohexane, 4,4/-diisocyanatedicyclohexylmethane, and inphorone diisocyanate.

The short chain di-/l/ used in the present invention is an ester group-containing diol e [mu] having less than 500 molecular needles as an essential component. The ester group-containing diol includes a 1:1 (mole ratio) of a glycol and a hydroxy group-containing monocarboxylic acid, and a 1:1 (mole ratio) of a compound having three hydroxy groups in one molecule and a monocarboxylic acid. ratio) ester compounds.

Examples of glycols include aliphatic glycols, alicyclic glycols, and aromatic glycols having a fi char count of 2 to 1o, especially ethylene glycol.

Propylene glyco-/', 114-butanediol.

Neopentyl glyco-/l/, 116-hexanedioh is preferred.

The hydroxy group-containing carboxylic acid is a hydroxy group-containing aliphatic monocarboxylic acid having 2 to 20 carbon atoms.

Examples include aromatic monocarboxylic acids containing a hydroxy group or alicyclic monocarboxylic acids containing a hydroxy group having 7 to 20 carbon atoms, particularly glycolic acid and lactic acid.

Hydroxy group-containing aliphatic monocarboxylic acids such as hydroxycaproic acid and hydroxypivalic acid are preferred. Examples of compounds having three hydroxy groups in the molecule include glycerin and trimethylo-p-propane.

As monocarboxylic acids, aliphatic monocarboxylic acids having 2 to 20 carbon atoms, aromatic monocarboxylic acids having 7 to 20 carbon atoms,
Examples include alicyclic monocarboxylic acids, and aliphatic monocarboxylic acids such as caproic acid and stearic acid are particularly preferred.

Examples of ester group-containing diols with a molecular ff of less than 1500 include fc, such as ester of ethylene glyco- and glyco-acid/L/, ester of ethylene glyco-μ and lactic acid/L7
．． Examples include ester /I/ of ethylene glycol and I-hydroxycaproic acid, ester of neopentyl glycol and hydroxypivalic acid, ester μ of neopentyl glycol and lactic acid, caproic acid monoglyceride, stearic acid monoglyceride, and the like. W In the present invention, an ester compound of neopentyl glycol and hydroxypivalic acid is particularly desirable.

Other than ester group-containing diols having a molecular weight of less than 500, shortened diols include ethylene glyco-/l/, propylene glyco-1v-L4-tetramethylene glyco-/'+
L6-hexanedio-/I/, cyclohexanedimethanol-1v, xylylene glycol, neopentyl glycol, ethylene oxide adduct of bispheno-A/A,
Low molecular weight diols such as propylene oxide adducts of bispheno-A/A.

Monoethanolamine, N-methylethanolamine,
Amino alcohols such as N-phenylethanolamine,
Diamines such as 4.4'-methylenebis2-chloroaniline and inphoronediamine, or water can be mentioned.

Examples of short-chain diols other than those mentioned above include crow-containing compounds represented by the following general formula (I[).

(In the formula, +RIIR2 represents a monovalent hydrocarbon group.

May be the same or different. R3+ R4 Alkylene group, oxyalkylene group or polio? T-V alkylene group, which may be the same or different. X.

When R3+R4 is an alkylene group, id: represents a hydroxyl group, and when R81R4 is an oxyalkylene group or polyoxyal, it represents hydrogen. ) When a phosphorus-containing compound represented by the general formula [2] is used as a raw material for thermoplastic polyurethane resin, it is particularly effective in improving the low dividing ability of inorganic pigments and fillers, which is a drawback of conventional polyurethane resins. .

Ester group-containing diols with a molecular weight of less than 500 are used in the range of 50 to 100-v:/L/% of the total short chain diols +1
1- If the molecular weight of the ester group-containing diol exceeds 500,
This is not preferred because the excellent mechanical strength characteristic of polyurethane resins is reduced.

The method for producing thermoplastic polyurethane resin is a one-shot method in which all reaction components are reacted at the same time.

An isocyanate group-terminated prepolymer obtained by reacting a long-chain diol with an incyanate component is converted into an i-benzene diol (
There is a prepolymer method in which the polymer is made into a polymer using (extending agent). The thermoplastic polyurethane resin of the present invention can be produced by either a one-shot method or a prepolymer method.

Thermoplastic polyurethane resins can be produced by using raw materials in a molten state or by dissolving them in a solution.In the case of the present invention, the entire reaction is carried out using methyl ethyl ketone, toluene,
A method in which the prepolymer is prepared in a melt state using ethyl acetate or the like or in a mixture of Vi and #extended anti-F3.
It is preferable to carry out the method in a solvent.
As the fused-11, stannous octylate, diptyltin dilaurate, triethylamine, etc. may be used.

Further, ultraviolet absorbers, hydrolysis inhibitors, antioxidants, etc. may be added before, during or after the production of the thermoplastic polyurethane resin.

In the present invention, an ester-based diol having a molecular weight of less than 500 is used as the short-chain diol.

A thermoplastic polyurethane resin having excellent solubility in general-purpose solvents, long-term solution stability, low solution viscosity, and excellent pigment dispersibility can be obtained. The polyurethane resin obtained in the present invention is a coating agent.

Can be widely used in inks, paints, adhesives, etc.

Hereinafter, the present invention will be specifically explained with reference to Examples.

In the examples, parts simply indicate parts by weight.

Examples 1-6. Comparative Examples 1 to 5 In a reaction vessel equipped with a thermometer, a stirrer, and an A-flow cooler, 181 parts of toluene, 181 parts of methyl ethyl ketone, 100 parts of the polyester resin (A) listed in Table 1, and neobenchi-hydroxypylene were added. Charge 20 parts of Barate, and after dissolving, add 35.5 parts of diphenylmethane diisocyanate and 0.05 parts of dibutyv tin dilaurate.
The reaction was carried out at 80°C for 10 hours. The resulting polyurethane resin (1) solution was a pale yellow, transparent solution with a solution viscosity of 41 poise/25° C. and a solid content concentration of 40 poise. When this solution was left in an atmosphere at 4° C. for 6 months, no changes such as gelation or cloudiness were observed, and it had excellent storage stability. In addition, the number average molecular weight of the polyurethane resin (1) is
As measured by gel permeation chromatography, it was 25,000 in terms of standard polystyrene.

Polyurethane resins of Examples 2 to 6 and Comparative Examples 1 to 5 were obtained in the same manner. Each raw material component, solution characteristics, storage stability,
The resin properties are shown in Table-1. The comparative example uses a diol that does not contain an ester group as a short chain diol,
The transparency and storage stability of polyurethane resin solutions are poor, and the solution viscosity is high.

Table 1 Polyester resin (A): Isophtha A/acid/15-sodium orthophthalic acid sulfoisophthalic acid/neopentyl glyco/I//ethylene glycol/L//cyclohexanedimethanol/I/Tomi 60/38/2150 /15/35 (molar ratio) Molecular weight 2.100 Polyester resin (B): 2-Hydroxyethoxy Vbenzo M acid/Isophthalic acid/Neobenchi ρClicor ILL/Ethylene glyco/L//Cyclohexane dimetatool=20/80 /60/30/
10 (mole ratio) molecular weight 2.000 Polyester resin (C): Isophthalic acid/adipic acid/neopentyl glyco-/I
//Ethylene glycol = 70/30/65/35 (
Molar ratio) Molecular weight 2,000 Polyester resin (D): Adipic acid/1,4-butanedio-y=100/100
(Mole ratio) Molecular weight 2,000 Polyester resin (E): Terephthalic acid/Adipic acid/Neopentyl glyco-/I
//Ethylene glycol = 70/30/65/35
(Mole ratio) Molecular weight 2,100 MDI: 4.4'-diphenylmethane diisocyanate HDI: Hexamethylene diisocyanate HPN
:Neopentyl glycol-hydroxypinoclate H
CPN: Neobentyl glycol-I-caproic acid ester NPG: Neobentyl glycol PG: Propylene glycol HD: L6-hexanedio-A' Table 2 (preservability) in the margin below ○: No abnormality Δ: Slightly Yes ×: Cloudy or precipitated Patent applicant Toyobo Co., Ltd. Procedural amendment (voluntary) Commissioner of the Patent Office Kazuo Wakasugi Patent application dated November 26, 1981 2 Name of the invention Method for producing thermoplastic polyurethane resin 8 Relationship with the case of the person making the amendment Patent applicant 2-2 Dojimahama, Kita-ku, Osaka @ No. 8 4 Column 5 of “Detailed description of the invention” of the specification subject to the amendment Contents of the amendment “Manufacturing thermoplastic polyurethane” The amount of organic diisocyanate varies depending on the molecular weight of the target polyurethane resin, but in general, the amount of organic diisocyanate is preferably within the following range, especially from the storage stability of the resin (influenced by humidity), where the pine resin has a hydroxyl group at the end. It is particularly desirable that

Claims (1)

[Claims] A method for producing a thermoplastic polyurethane resin by reacting a long chain diol, a double diisocyanate, and a short chain diol, characterized in that an ester group-containing diol with a molecular size of less than 500 is used as the short chain diol. manufacturing method.