JP2000086740A - Method for producing polyurethane urea resin for synthetic leather or elastic yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject low-hardness resin good in touch feeling, rich in recovery properties after stretching and excellent in chlorine resistance by reacting a specific isocyanate group-terminated prepolymer with a chain extender in a solvent, then further adding an isocyanate compound thereto and removing the solvent. SOLUTION: (A) An isocyanate group-terminated prepolymer obtained by reacting a high-molecular weight active hydrogen compound such as polyoxytetramethylenediol with (B) an isocyanate compound such as diphenylmethane diisocyanate is reacted with (B) a chain extender such as ethylenediamine in a solvent to thereby provide (C) a polymer. (D) An isocyanate compound is further added thereto and the solvent is then removed to produce the objective resin. The component D is preferably an isocyanate group- terminated prepolymer prepared by reacting a high-molecular weight active hydrogen compound having 2-8 active hydrogen-containing groups with a polyisocyanate compound in a ratio so as to provide an excess of the isocyanate groups over hydroxyl groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing a polyurethane urea resin for synthetic leather or elastic yarn, which comprises reacting a polymer of an isocyanate group-terminated prepolymer and a chain extender with an isocyanate compound. About.

[0002]

2. Description of the Related Art Hitherto, when producing a polyurethane urea resin for synthetic leather or elastic yarn, polyoxytetramethylene diol or polyester polyol having an average molecular weight of 3000 or less has been mainly used as a high molecular weight active hydrogen compound. . However, resins obtained by using these compounds have relatively hard properties, and therefore, resins having lower hardness and thus good texture are strongly demanded.

In order to lower the hardness of the resin, there are a method of increasing the molecular weight of the high molecular weight active hydrogen compound to relatively reduce the amount of the hard segment, and a method of adding a plasticizer or the like.

However, when the molecular weight of polyoxytetramethylene diol or polyester polyol is increased, the viscosity of the liquid increases greatly, so that there is a problem that processing and production become difficult. Further, polyurethane urea resin for synthetic leather or elastic yarn produced using high molecular weight polyoxytetramethylene diol or polyester polyol has a problem that the recoverability after elongation is poor. In addition, there is a similar problem even when a method of reducing the hardness by using a plasticizer is used.

Further, synthetic leather or elastic yarn using polyurethane urea resin has a problem that the chlorine resistance is poor and the durability to a bleaching agent or the like is poor.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a polyurethane for synthetic leather or elastic yarn which has a low hardness, therefore has a good texture, is rich in recovery after stretching, and has chlorine resistance. An object of the present invention is to provide a method for producing a urea resin.

[0007]

To achieve the above object, the present invention provides an isocyanate group-terminated prepolymer (A) and a chain extender (B) obtained by reacting a high molecular weight active hydrogen compound with an isocyanate compound. Is obtained in a solvent to obtain a polymer (C), an isocyanate compound (D) is further added, and then the solvent is removed, thereby producing a polyurethane urea resin for synthetic leather or elastic yarn. Is provided.

[0008] In the present invention, the isocyanate compound (D) is obtained by mixing a polymer active hydrogen compound (E) having active hydrogen-containing groups 2 to 8 and a polyisocyanate compound with an isocyanate group in excess of hydroxyl groups. The prepolymer is preferably an isocyanate group-terminated prepolymer obtained by reacting at the following ratio.

Further, in the above, at least a part of the high molecular active hydrogen compound (E) is a polyoxypropylene polyol, a polydiene polyol, a hydrogenated polydiene polyol, a polysiloxane polyol, a fluorinated polyol, and More preferably, it is at least one polymer polyol selected from castor oil-based polyols.

According to the production method of the present invention, the polymer (C)
It has been found that the strength of the obtained polyurethane urea resin is improved by adding the isocyanate compound (D) to the resin. This is probably because the isocyanate reacts with the urea bond of the polymer (C) to form a burette bond. Since the polymer (C) is cross-linked by the isocyanate compound (D) in this way, it has low hardness, good texture, rich recovery after stretching, and excellent chlorine resistance or synthetic leather or elasticity. A polyurethane urea resin for yarn can be obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a high-molecular-weight active hydrogen compound used to obtain an isocyanate group-terminated prepolymer (hereinafter, also simply referred to as "prepolymer") (A) has an active hydrogen-containing group, It preferably has one or more, more preferably 1.8 to 8, and still more preferably 1.8 to 4.
Have. Most preferably, it is 1.8-2. As the high molecular weight active hydrogen compound, a high molecular weight polyol having two or more hydroxyl groups as active hydrogen-containing groups, or a high molecular weight polyol and a small amount of a high molecular weight monol are preferable. The hydroxyl value of the high molecular weight polyol is preferably 70 or less. Further, the hydroxyl value is preferably 5 or more, particularly preferably 20 or more. Specific examples include polyoxyalkylene polyol, polyester polyol, polylactone polyol, polycarbonate polyol, and the like.

As the polyoxyalkylene polyol, polyoxypropylene polyol, polyoxyethylene polyol, polyoxyethylene oxypropylene polyol, polyoxytetramethylene polyol and the like are preferable. Among these, polyoxytetramethylene polyol is particularly preferred, and polyoxytetramethylenediol is most preferred.

As the polyester polyol, one or a mixture of two or more selected from dibasic acids such as oxalic acid, succinic acid, glutaric acid, fumaric acid, sebacic acid, maleic acid, itaconic acid, adipic acid and malonic acid; One or a mixture of two or more selected from low molecular weight diols such as ethylene glycol, propylene glycol, butane glycol, neopentyl glycol, hexamethylene glycol, and cyclohexanemethanol, and optionally trifunctional such as trimethylolpropane, glycerin, and pentaerythritol One obtained by reacting one or a mixture of two or more kinds selected from the above alcohol compounds at a ratio of an excess of hydroxyl groups to carboxyl groups is preferable. Further, a polyester having a carboxyl group at the terminal obtained by reacting the carboxyl group in an excess ratio with respect to the hydroxyl group, for example, polyoxyethylene diol, polyoxypropylene diol, polyoxytetramethylene diol, polyoxypentamethylene It is also possible to use a polyester-polyoxyalkylene polyol obtained by further reacting a polyoxyalkylene diol such as a diol.

As the polylactone polyol, those obtained by ring-opening polymerization of ε-caprolactone, γ-butyrolactone and the like are preferable.

As the polycarbonate polyol, alkylene carbonates and 1,4-butanediol,
Poly (butane-1,4-carbonatediol), poly (pentane-1,5) obtained by reaction with a low molecular weight diol such as 1,3-pentanediol, 1,5-pentanediol, 1,6-hexanediol -Carbonate diol), poly (hexane-1,6-carbonate diol) and their copolymers and polycarbonate diols obtained from mixtures thereof are preferred.

Further, as high molecular weight active hydrogen compounds,
Monools such as polyoxyalkylene monools may be used in combination.

In the present invention, a diisocyanate compound is preferable as the isocyanate compound used for obtaining the prepolymer (A). Specifically, 1,6-
Propane diisocyanate, 1,4-butane diisocyanate, 1,5-pentane diisocyanate, 1,6-
Hexane diisocyanate, 3-methylhexane-1,
Aliphatic diisocyanates such as 6-diisocyanate and 3,3-dimethylpentane-1,5-diisocyanate, isophorone diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, 1,3- and 1,
Alicyclic diisocyanates such as 4-cyclohexylene diisocyanate, m- and p-xylylene diisocyanate, α, α, α ′, α′-tetramethyl-p-xylylene diisocyanate, 1,4-phenylene diisocyanate, 4, Aromatic diisocyanates such as 4'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 1,5-naphthalene diisocyanate, 2,6-naphthalene diisocyanate, and tolidine diisocyanate.

In the present invention, when the high molecular weight active hydrogen compound is reacted with the isocyanate compound to produce the isocyanate group-terminated prepolymer (A), the reaction ratio of the high molecular weight active hydrogen compound to the isocyanate compound (the molar ratio of the isocyanate group) Number / mol number of hydroxyl group) is 1.2 to
The range of 3 is preferable, and the range of 1.4 to 1.8 is more preferable. When the value of the above ratio is less than 1.2, the prepolymer becomes extremely high in viscosity, and handling becomes difficult. If it exceeds 3, the strength and elongation properties of the polyurethane urea resin to be formed become insufficient, which is not preferable.

The chain extender (B) in the present invention includes:
Diamine compounds are preferred. Specifically, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-butylenediamine, 1,3-butylenediamine, 1,4-butylenediamine, 1,5-hexanediamine, , 6-hexanediamine, isophoronediamine, piperazine, 2-methylpiperazine, tolylenediamine, isobutylenediamine, hydrazine,
3,3′-dichloro-4,4′-biphenyldiamine,
2,6-diaminopyridine, 4,4'-diaminodiphenylmethane, m- and p-phenylenediamine, m-
And p-xylylenediamine, 1,3- and 1,4
-Cyclohexanediamine and the like, particularly preferably ethylenediamine and 1,2-propylenediamine.

On the other hand, in the present invention, as the isocyanate compound (D) to be added to the polymer (C), an isocyanate group-terminated prepolymer is preferable, and the high molecular weight active hydrogen compound (E) and the polyisocyanate compound are used in excess of the isocyanate group. What is obtained by making it react with is preferable.
(Mole number of isocyanate group) / (mol number of hydroxyl group) is preferably in the range of 1.2 to 3, more preferably 1.4 to 3.
It is in the range of 1.8. When the value of the above ratio is less than 1.2, the prepolymer has a very high viscosity, and handling becomes difficult. The strength of the urethane urea resin to be generated when it exceeds 3,
It is not preferable because elongation characteristics and the like become insufficient.

Such a high molecular weight active hydrogen compound (E)
As active hydrogen-containing groups, preferably 2 to 8, preferably 2 to 4
Is preferred. High molecular weight polyols having two or more hydroxyl groups as active hydrogen-containing groups are particularly preferred. The hydroxyl value of the high molecular weight polyol is preferably 60 or less. Further, the hydroxyl value is preferably 5 or more, particularly preferably 8 or more.

Such a high molecular weight active hydrogen compound (E)
Is preferably a highly hydrophobic polyol selected from a polyoxypropylene-based polyol, a polydiene-based polyol, a hydrogenated polydiene-based polyol, a polysiloxane-based polyol, a fluorinated polyol, and a castor oil-based polyol. By using such a polymer polyol, the chlorine resistance of the obtained polyurethane urea resin can be greatly improved.

The polyoxypropylene-based polyol preferably has an average of 2 to 4 hydroxyl groups. If the average number of hydroxyl groups is less than 2, the cross-linking effect due to the addition of the prepolymer is lost, and the reinforcing effect on the strength and durability properties is lost, which is not preferable. Further, the polyoxypropylene-based polyol referred to in the present invention refers to a polyol in which 75% by weight or more of oxyalkylene groups are oxypropylene groups. It may contain less than 25% by weight of oxyethylene groups, but preferably does not substantially contain it. Further, the hydroxyl value is preferably 5 to 60.
When the hydroxyl value is more than 60, the obtained resin becomes hard,
It has an adverse effect on properties such as elongation. On the other hand, if the hydroxyl value is less than 5, the viscosity of the prepolymer becomes extremely high, and processing becomes difficult.

The polyoxypropylene polyol is produced by a ring-opening addition reaction between propylene oxide and another cyclic ether in the presence of a catalyst using a polyhydric alcohol, a saccharide, an alkanolamine, a polyhydric phenol or the like as an initiator. Is preferably performed. Examples of the cyclic ether other than propylene oxide include alkylene oxides such as ethylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide. Propylene oxide or propylene oxide and ethylene oxide are preferred, and propylene oxide alone is particularly preferred.

The catalyst is preferably a general-purpose alkali catalyst such as potassium hydroxide or sodium hydroxide, a cesium catalyst such as cesium hydroxide, a double metal cyanide complex catalyst, or a porphyrin catalyst.

Particularly, those produced using a double metal cyanide complex catalyst are preferred. Such a polyoxypropylene-based polyol has a narrow molecular weight distribution and is a relatively uniform molecular weight polyoxypropylene-based polyol,
When such a polyol is used, the resulting resin has excellent elasticity. In addition, as a double metal cyanide complex catalyst, a zinc hexacyanocobaltate complex is preferable.

Examples of the polydiene-based polyol include polybutadiene polyol, and examples of the hydrogenated polydiene-based polyol include hydrogenated polybutadiene polyol. As the castor oil-based polyol, castor oil or a modified castor oil can be used.

Of the above high molecular weight polyols, polyoxypropylene-based polyols are particularly preferred.

Further, in the present invention, as the high molecular weight active hydrogen compound (E), the above high molecular weight polyol and another high molecular weight polyol may be used in combination. As the high molecular weight polyol that can be used in combination, a polyoxytetramethylene polyol having 5 to 70 hydroxyl groups is preferable. The hydroxyl value is particularly preferably from 30 to 60.

The mixing ratio of the above high molecular weight polyol to another high molecular weight polyol is 10 to 100/9 by weight.
0-10 are preferable, and 30-80 / 70-20 are more preferable. Thereby, the obtained polyurethane urea resin becomes rich in elasticity.

Further, the high molecular weight active hydrogen compound (E) is preferably a high molecular weight polyol having an average number of functional groups of more than 2. In particular, the average number of functional groups of the high molecular weight active hydrogen compound as the raw material of the prepolymer (A) is 1.8 to 2, and the average number of functional groups of the high molecular weight active hydrogen compound (E) exceeds 2, especially It is preferably 2.1 to 3.

The polyurethane urea resin for synthetic leather or elastic yarn of the present invention is prepared by first reacting a high molecular weight active hydrogen compound with an isocyanate compound to synthesize a prepolymer (A). It is dissolved in an organic solvent such as dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide and the like to obtain a prepolymer solution. Then, a chain extender (B) is added to this prepolymer solution.
And a polymerization reaction is carried out to obtain a polymer (C) solution having a concentration of 15 to 40%.

The amount of the chain extender (B) used is
The amount is preferably such that the molar ratio between the isocyanate groups in the prepolymer solution and the amino groups in the amine compound is in the range of 1.4 to 1.02. Outside of this range, the polymer molecular weight becomes too large or too small, so that it is difficult to mold the resin and the resin strength is not sufficiently obtained.

When the polymerization reaction is carried out, a terminal terminator such as diethylamine, dibutylamine, diethanolamine or the like may be used to adjust the molecular weight of the polymer.

Further, the temperature at which the polymerization reaction is carried out is from 0 to 3
0 ° C. is preferred. If the temperature is lower than 0 ° C., the solubility of the prepolymer decreases, and the reaction system becomes non-uniform. If the temperature is higher than 30 ° C., the reaction between the isocyanate group and the amino group becomes abnormally fast and the reaction becomes difficult to control. Absent.

Next, an isocyanate compound (D) is added to the obtained polymer (C) solution and reacted. In this case, the proportion of the isocyanate compound (D) added to the polymer (C) is preferably 5 to 40% by weight.

Thereafter, by curing while removing the solvent, the polyurethaneurea resin for synthetic leather or elastic yarn of the present invention can be produced.

The polyurethane urea resin for synthetic leather or elastic yarn in the present invention may contain various additives such as an antioxidant and an ultraviolet absorber.

The thus obtained polyurethane urea resin for synthetic leather or elastic yarn of the present invention is, in addition to synthetic leather,
It can be used as an elastic yarn. The elastic yarn can be used for stockings, underwear, disposable diapers, rubber parts of pants, socks and the like.

[0040]

The present invention will be described below in more detail with reference to examples. Hereinafter, “parts” means “parts by weight”.
That is.

In Examples and Comparative Examples, the measurement of physical properties such as elongation (%), 100% modulus (kg / cm ² ), and tensile strength (kg / cm ² ) was performed according to JIS-K.
The test was carried out in accordance with the test method for polyurethane thermoplastic elastomer of No. 7311.
A test was performed using dumbbell pieces used in JIS-K 7311, and after elongating 300% at a speed of 300 cm / min,
When returning to the extension start position at the same speed, the position where the stress becomes zero was measured. If the elongation start position is the same as the position where the stress becomes zero, the recoverability is set to 100%. Further, the retention rate (%) of the tensile strength was obtained by immersing a sample formed into a film having a thickness of 100 μm in a 1% by weight aqueous solution of sodium hypochlorite and retaining the tensile strength after 6 hours at 50 ° C. Was measured and determined.

Production Example 1 (Preparation of Polyurethane Urea Polymer Solution) Polyoxytetramethylenediol having a molecular weight of 2,000 (trade name: PTG-2000SN)
833 parts of diphenylmethane diisocyanate (manufactured by Hodogaya Chemical) and 167 parts of diphenylmethane diisocyanate (trade name "Millionate MT" manufactured by Nippon Polyurethane Industry, the same applies to diphenylmethane diisocyanate used in the following production examples) are reacted at 80 ° C. for 6 hours in a nitrogen atmosphere. Thus, a prepolymer having an isocyanate group content of 2.1% by weight was obtained.

Next, this prepolymer was dissolved in N, N'-dimethylacetamide (hereinafter referred to as DMAc) to obtain a urethane prepolymer solution having a solid content of 30% by weight. Further, a DMAc solution containing 17.5 parts of ethylenediamine and 1.3 parts of diethylamine was added to a vigorously stirred urethane prepolymer solution, and a polymerization reaction was carried out to obtain a polyurethaneurea polymer solution.

Production Example 2 (Preparation of Polyurethane Prepolymer) The following polyoxyalkylene polyol (hereinafter referred to as polyol) was used as a raw material of the polyurethane prepolymer.
Was used. The polyols A, B, C, E, F and G were prepared by adding propylene oxide using a polyoxypropylene polyol having a molecular weight of 400 to 600 as an initiator and adding a zinc hexacyanocobaltate complex as a catalyst, and then removing a catalyst component by purification. The polyols D and H were prepared by adding propylene oxide using a polyoxypropylene polyol having a molecular weight of 400 to 600 as an initiator, a zinc hexacyanocobaltate complex as a catalyst, and then deactivating the catalyst. It is manufactured by adding ethylene oxide using an alkali catalyst and then purifying to remove the catalyst component.

For each of the polyols A to H thus obtained, the number of hydroxyl groups (N) and the oxyethylene group content (E
O) and the hydroxyl value (X) are shown in Table 1.

[0046]

[Table 1]

Next, the kinds and parts by weight of the polyol shown in Table 2 and the parts by weight of diphenylmethane diisocyanate shown in Table 2 were reacted at 80 ° C. for 6 hours in a nitrogen atmosphere to obtain prepolymers (No. 1 to No. 1). 4) was synthesized. Table 2 shows the isocyanate group content of each prepolymer.

[0048]

[Table 2]

Example 1 Prepolymer N was added to 80 parts of the polymer solution obtained in Production Example 1.
DMAc was evaporated from a polymer solution obtained by adding 20 parts of a 30% by weight DMAc solution of o.1 and the polymer was dried to obtain a film-shaped sample having a thickness of 100 μm. This was cured at room temperature for 10 days, and the physical properties were measured. Table 3 shows the results.

Example 2 A 100 μm thick film sample was prepared in the same manner as in Example 1 except that Prepolymer No. 2 was used instead of Prepolymer No. 1. This was cured at room temperature for 10 days, and the physical properties were measured. Table 3 shows the results.

Example 3 A 100 μm thick film sample was prepared in the same manner as in Example 1 except that Prepolymer No. 3 was used instead of Prepolymer No. 1. This was cured at room temperature for 10 days, and the physical properties were measured. Table 3 shows the results.

Example 4 A 100-μm-thick film sample was prepared in the same manner as in Example 1 except that Prepolymer No. 4 was used instead of Prepolymer No. 1. This was cured at room temperature for 10 days, and the physical properties were measured. Table 3 shows the results.

Example 5 100 parts of castor oil polyol having a hydroxyl value of 160 (trade name "Euric H-30" manufactured by Ito Oil Co., Ltd.) and 43 parts of diphenylmethane diisocyanate were mixed with 80 parts of nitrogen in a nitrogen atmosphere.
C. for 6 hours to give an isocyanate group content of 1.6.
% By weight of the prepolymer was obtained. A film-like sample having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the above prepolymer was used instead of prepolymer No. 1. This was cured at room temperature for 10 days, and the physical properties were measured. Table 3 shows the results.

Example 6 Polybutadiene polyol having a hydroxyl value of 45 (trade name "p
(poly-bd45HT, manufactured by Idemitsu Petroleum Co., Ltd.) and 100 parts of diphenylmethane diisocyanate were reacted at 80 ° C. for 6 hours in a nitrogen atmosphere to obtain a prepolymer having an isocyanate group content of 2.2% by weight. Prepolymer No.
Example 1 except that the above prepolymer was used instead of
In the same manner as in the above, a film-shaped sample having a thickness of 100 μm was prepared. This was cured at room temperature for 10 days, and the physical properties were measured. Table 3 shows the results.

Comparative Example 1 DMAc was evaporated from the polymer solution of Production Example 1, and the polymer was dried to obtain a film-like sample having a thickness of 100 μm. This was cured at room temperature for 10 days, and the physical properties were measured. Table 3 shows the results.

Comparative Example 2 After adding 6 parts of dioctyl phthalate to 100 parts of the polymer solution of Production Example 1, DMAc was evaporated and the polymer was dried to obtain a film-like sample having a thickness of 100 μm. . This was cured at room temperature for 10 days, and the physical properties were measured. Table 3 shows the results.

[0057]

[Table 3]

Further, the films of Examples 1 to 6 and Comparative Example 1 were immersed in a 1% by weight aqueous solution of sodium hypochlorite, and the results of comparison of the tensile strength retention after 6 hours at 50 ° C. were as follows. It is shown in Table 4.

[0059]

[Table 4]

[0060]

As described above, according to the production method of the present invention, a synthetic material having a low hardness, a good feeling, a good recovery after elongation, and an excellent chlorine resistance. A polyurethane urea resin for leather or elastic yarn can be obtained.

Continued on the front page F term (reference) 4J034 BA07 BA08 CA13 CA15 CB01 CB03 CB07 CC03 CC12 CC23 CC26 CC28 CC29 CC33 CC45 CC52 CC61 CC62 CC65 CC67 CD13 CE03 DA01 DB01 DB03 DB07 DF02 DF11 DF12 DF16 DF20 DF29 DG03 DG04 DG05 DG05 DG04 DG05 DH02 DH06 DM01 DP15 EA12 GA06 GA23 GA33 GA55 HA01 HA07 HA15 HC03 HC12 HC13 HC17 HC22 HC46 HC52 HC61 HC64 HC67 HC70 HC71 HC73 JA02 JA14 JA30 JA42 QB15 QC05 RA03 RA09

Claims (3)

[Claims] An isocyanate group-terminated prepolymer (A) obtained by reacting a high molecular weight active hydrogen compound with an isocyanate compound is reacted with a chain extender (B) in a solvent to obtain a polymer (C). A method for producing a polyurethane urea resin for synthetic leather or elastic yarn, wherein the solvent is removed after the isocyanate compound (D) is further added. 2. The isocyanate compound (D) is reacted with a polymer active hydrogen compound (E) having 2 to 8 active hydrogen-containing groups and a polyisocyanate compound in such a ratio that an isocyanate group is excessive relative to a hydroxyl group. The method for producing a polyurethane urea resin for synthetic leather or elastic yarn according to claim 1, which is an isocyanate group-terminated prepolymer obtained by the reaction. 3. The polymer active hydrogen compound (E) wherein at least a part thereof is a polyoxypropylene polyol, a polydiene polyol, a hydrogenated polydiene polyol, a polysiloxane polyol, a fluorinated polyol, and a castor oil polyol. The method for producing a polyurethane urea resin for synthetic leather or elastic yarn according to claim 2, which is at least one polymer polyol selected from the group consisting of: