JP3193400B2 - Method for producing aqueous polyurethane polyurea dispersion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aqueous polyurethane polyurea dispersion having excellent heat resistance, oil resistance and storage stability.

[0002]

2. Description of the Related Art A conventional aqueous polyurethane polyurea dispersion is self-emulsifying by, for example, introducing a hydrophilic group into a polyurethane prepolymer skeleton, dispersing in water while neutralizing, and then elongating a chain with a polyamine. Polyurea, or forcibly dispersing hydrophobic polyurethane polyurea in water in the presence of a large amount of emulsifier.

[0003]

In the former aqueous dispersion of polyurethane polyurea, when a urethane prepolymer is neutralized and dispersed in water and then chain-extended with a polyamine compound,
When aromatic polyisocyanate is used as the organic polyisocyanate, the reactivity of the isocyanate group is so strong that the polymerization due to the reaction with water occurs at a not negligible rate. It was difficult to obtain a polymer dispersion. In order to solve this problem, aliphatic and alicyclic polyisocyanates having low reactivity are conventionally used as organic polyisocyanates. Therefore, the conventional polyurethane polyurea aqueous dispersion is expensive and has not been sufficiently satisfactory in performance. In addition, the latter polyurethane polyurea aqueous dispersion had disadvantages such as poor water resistance and solvent resistance of the obtained resin film because the large amount of emulsifier remained, and also the poor stability of the dispersion. . The present inventors have conducted intensive studies with the aim of resolving the above-mentioned deficiencies of the prior art, and as a result, used an aromatic polyisocyanate as an organic polyisocyanate and reacted a polyhydroxy compound and a compound containing a carboxyl group with the aromatic polyisocyanate. The aqueous dispersion of polyurethane polyurea obtained by adding water, a polyamine and a basic compound as a neutralizing agent to the carboxyl group-containing terminal NCO-type urethane prepolymer obtained as described above and emulsifying the chain at the same time as the chain elongation is extremely excellent in long-term storage stability. The present invention was found to be excellent and found that the resin film obtained from this aqueous dispersion was also excellent in water resistance and solvent resistance.

[0004]

That is, the present invention relates to (1) stirring a carboxyl group-containing terminal NCO-type urethane prepolymer obtained from an aromatic polyisocyanate, a polyhydroxy compound and a compound having a carboxyl group while stirring. A method for producing an aqueous polyurethane polyurea dispersion, wherein a mixed solution of water, a polyamine and a basic compound as a neutralizing agent is added thereto, and emulsion is formed simultaneously with chain elongation; 2. The method according to claim 1, wherein at least mol% is hydrazine.

More specifically, the carboxyl-containing NCO-terminated urethane prepolymer used in the present invention is prepared by converting a carboxyl-containing polyol and an aromatic polyisocyanate compound into NCO / O
Reaction at an H ratio of 1.1 or more, desirably 1.5 to 2.0,
Alternatively, a polyol, an aromatic polyisocyanate, and a chain extender containing a carboxyl group are combined in an NCO / OH ratio of 1.1.
As described above, it can be desirably obtained by reacting at 1.5 to 2.0. At this time, an organic solvent that does not react with the isocyanate may be added during the reaction or after the reaction is completed.

The polyol used in the present invention is:
A compound having at least two hydroxyl groups in the compound, and a conventionally known polyol which can be conventionally used for producing a polyurethane-based resin alone or
A mixture of more than one species can be used. Preferred examples of such conventionally known polyols include, for example,
Polyethylene adipate having a molecular weight of 300 to 4000,
Polyethylene propylene adipate, polyethylene butylene adipate, polydiethylene adipate, polybutylene adipate, polyethylene succinate, polybutylene succinate, polyethylene sebacate, polybutylene sebacate, polytetramethylene ether glycol, polyε-caprolactoneol, polyhexamethylene adipate , Polycarbonate all, polyethylene glycol, polypropylene glycol and the like.

The aromatic polyisocyanate used in the present invention includes tolylene diisocyanate, 4,4
-Methylenebis (phenylisocyanate), 1,5-
A compound in which at least two isocyanate groups are directly bonded to an aromatic ring such as naphthalene diisocyanate,
And burettes and isocyanurates thereof. The carboxyl group may be contained by a half ester copolymerization method using a half ester synthesized from a triol (for example, polycaprolactone triol) and an acid anhydride (for example, phthalic anhydride). A compound having one hydroxyl group and one or more carboxyl groups (for example, dimethylolpropionic acid) may be copolymerized.

[0008] The polyamine used in the present invention is:
Compounds containing two or more primary or secondary amino groups, such as hydrazine, ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, xylylenediamine, metaphenylenediamine, piperazine, maleic hydrazide and the like. However, a stable dispersion cannot be obtained unless 60 mol% or more of the polyamine is hydrazine. Although the reason why the range is limited is not necessarily clear, it is considered that the reason is due to the reaction speed with the prepolymer and the hydrophilicity of the resulting polyurethane polyurea.

The amount of the polyamine used is 50 to 150% (preferably 7%) of the isocyanate groups of the urethane prepolymer.
(0-100%). Examples of the basic compound as a neutralizing agent include inorganic bases such as sodium hydroxide, potassium hydroxide, and sodium carbonate; aqueous ammonia, trimethylamine, triethylamine, triethylenediamine, dimethylaminoethanol, and N-methylmorpholine. Tertiary amines are exemplified. The use amount of the neutralizing agent is preferably 50 to 100% of the equivalent of the carboxyl group of the NCO-terminated urethane prepolymer having a carboxyl group. As the amount used increases, the transparency increases and the viscosity increases. Therefore, an appropriate amount is selected according to the application and usage.

In order to carry out the method of the present invention, an NCO-terminated urethane prepolymer containing a carboxyl group may be added to a mixture of water, a polyamine and a neutralizing agent while stirring. A method may be employed in which water, a polyamine, and a neutralizing agent are added to the urethane prepolymer while stirring it. A polyurethane polyurea aqueous dispersion having a nonvolatile content of 10 to 60% can be easily obtained. However, if an organic solvent is used and a method of removing the dispersion after manufacturing the dispersion is employed, the nonvolatile content can be increased to about 80%. .

[0011]

According to the present invention, an aromatic polyisocyanate is used by taking a production method of adding a mixture of water, a polyamine mainly composed of hydrazine, and a neutralizing agent to a carboxyl group-containing terminal NCO type urethane prepolymer. Thus, a polyurethane polyurea was synthesized while suppressing a side reaction between water and isocyanate, and it was possible to stably disperse it in water. This makes it possible to supply a stable polyurethane polyurea aqueous dispersion which is inexpensive and has excellent properties such as heat resistance and oil resistance. Hereinafter, the present invention will be specifically described with reference to examples.

[0012]

【Example】

Example 1 500 parts by weight of PPG diol 1000 [trade name: Diol 1000, manufactured by Mitsui Toatsu Chemicals, Inc.], 40 parts by weight of dimethylolpropionic acid, and 208 parts by weight of TDI were mixed at 80 ° C. with 5 parts by weight.
Urethane prepolymer [1] having a NCO content of 3.81% and a carboxyl group content of 0.4 meq.
I got 748 parts by weight of the urethane prepolymer [1] is cooled to 50 ° C. and, with stirring, 1104 parts by weight of water, 24.1 parts by weight of triethylamine, 20.2 parts by weight of hydrazine hydrated with 60%, 4.61 parts of isophoronediamine. A part by weight of the mixture is added dropwise. After the completion of the dropwise addition, the mixture was reacted at 60 ° C. for 1 hour to obtain an aqueous polyurethane polyurea dispersion having a nonvolatile content of 40%.

Example 2 500 parts by weight of polycaprolactone diol 2000 (trade name: Praxel 220 manufactured by Daicel Chemical Industries), 100 parts by weight of Praxel 305 (polycaprolactone triol 500: Daicel Chemical Industries) and 27 parts by weight of phthalic anhydride Were reacted at 120 ° C. for 3 hours, and 129 parts by weight of a half ester and 117 parts by weight of TDI were reacted at 70 ° C. for 8 hours in the presence of 187 parts by weight of acetone to obtain an NCO content of 2.06% and a carboxyl group. 0.24 content
A urethane prepolymer [2] having an mm equivalent was obtained. 933 parts by weight of this urethane prepolymer [2] is cooled to 50 ° C., and while stirring, 894 parts by weight of water, 15.4 parts by weight of dimethylaminoethanol, and 19.5 parts of hydrazine hydrated with 60% water.
A part by weight of the mixture is added dropwise. After completion of the dropwise addition, the mixture was reacted at 60 ° C. for 1 hour, and further treated at the same temperature for 1 hour under reduced pressure at 100 mmHg to remove acetone, thereby obtaining an aqueous polyurethane polyurea dispersion having a nonvolatile content of 45%.

Example 3 Polyvalerolactone diol 2000 [Clapol L-
2010: Kuraray] 500 parts by weight, 33.4 parts by weight of dimethylolpropionic acid, and 156 parts by weight of TDI are reacted at 80 ° C. for 5 hours in the presence of 77 parts by weight of acetone to form NC.
A urethane prepolymer [3] having an O content of 3.93% and a carboxyl group content of 0.33 mm equivalent was obtained. 766 parts by weight of the urethane prepolymer [3] was cooled to 50 ° C.
While stirring, 1250 parts by weight of water, 34.8 parts by weight of 25% ammonium hydroxide water, 23.6 parts by weight of hydrazine hydrated 60%,
A mixture of 2.2 parts by weight of ethylenediamine is added dropwise. After completion of the dropwise addition, the mixture was reacted at 60 ° C. for 1 hour, and further subjected to a reduced pressure treatment at 100 mmHg at the same temperature for 1 hour to remove acetone, thereby obtaining an aqueous polyurethane polyurea having a nonvolatile content of 35%.

Comparative Example 1 The urethane prepolymer [1] 748 obtained in Example 1
1104 parts by weight of water, 24 parts by weight of triethylamine.
The mixture was added dropwise to 1 part by weight of the mixed solution while stirring to form an aqueous dispersion, and 20.2 parts by weight of 60% hydrated hydrazine and 4.61 parts by weight of isophoronediamine were added thereto.
The reaction was carried out at 1 ° C. for 1 hour to obtain an aqueous polyurethane polyurea dispersion having a nonvolatile content of 40%.

Comparative Example 2 The urethane prepolymer [1] 748 obtained in Example 1
1104 parts by weight of water, 24 parts by weight of triethylamine.
1 part by weight and 46.1 parts by weight of isophoronediamine were added dropwise with stirring to obtain a polyurethane polyurea aqueous dispersion having a non-volatile content of 40%. Did not.

Comparative Example 3 The urethane prepolymer [2] 933 obtained in Example 2
The mixture was cooled to room temperature, and a mixed solution of 894 parts by weight of water and 15.4 parts by weight of dimethylaminoethanol was added dropwise with stirring. After dispersing in water, 19.5 parts by weight of 60% hydrazine hydrate was added. . The reaction was carried out at 60 ° C. for 1 hour, and the pressure was reduced to 100 mmHg at the same temperature for 1 hour to remove acetone to obtain an aqueous polyurethane polyurea dispersion having a nonvolatile content of 45%.

Comparative Example 4 Urethane prepolymer [2] 933 obtained in Example 2
The mixture was cooled down to room temperature, and a mixture of 897 parts by weight of water, 15.4 parts by weight of dimethylaminoether and 11 parts by weight of ethylenediamine was added dropwise with stirring, reacted at 60 ° C. for 1 hour, and further reacted at the same temperature for 1 hour. The acetone was removed by reducing the pressure to 100 mmHg to obtain an aqueous polyurethane polyurea dispersion having a nonvolatile content of 45%.

Comparative Example 5 The urethane prepolymer [3] 766 obtained in Example 3
1250 parts by weight of water, 25% ammonia water 3
The mixture was added dropwise to 4.8 parts by weight of the mixed solution with stirring to obtain an aqueous dispersion, and 23.6 parts by weight of 60% hydrazine hydrate and 2.2 parts by weight of ethylenediamine were added thereto.
After reacting for an hour, the pressure was reduced to 100 mmHg at the same temperature for 1 hour to remove acetone to obtain an aqueous polyurethane polyurea having a nonvolatile content of 35%. Example 1 and Example 2 described above,
The aqueous polyurethane polyurea dispersions obtained in Example 3 and Comparative Examples 1, 2, 3, 4 and 5 were each 50 mm in diameter and 300 mm in height.
Table 1 shows the results of testing the stability of the aqueous dispersion.

Table 1 (Stability of aqueous polyurethane polyurea dispersion)sample State after leaving for 2 months  Example 1 No abnormality Example 2 No abnormality Example 3 No abnormality Comparative Example 1 Separation / sedimentationComparative Example 2 Without a dispersionComparative Example 3 Separation / sedimentationComparative Example 4 GelationComparative Example 5 Separation / sedimentation

[0021]

According to the present invention, polyurethane polyurea can be stably dispersed in water for a long period of time while using an aromatic polyisocyanate. The polyurethane polyurea aqueous dispersion obtained by the present invention is a coating,
Used for printing inks, adhesives, fiber coating agents, etc., it can form a resin film having excellent water resistance and oil resistance.

────────────────────────────────────────────────── (5) References JP-A-62-109813 (JP, A) JP-A-52-19799 (JP, A) JP-A-3-19538 (JP, A) (58) Field (Int. Cl. ⁷ , DB name) C08G 18/00-18/87

Claims (2)

(57) [Claims] 1. A carboxyl group-terminated NCO type urethane prepolymer obtained from an aromatic polyisocyanate, a polyhydroxy compound and a carboxyl group-containing compound is stirred with water, polyamine and a neutralizing agent. A method for producing an aqueous polyurethane polyurea dispersion, comprising adding a mixed solution of a basic compound and emulsifying simultaneously with chain elongation. 2. The method according to claim 1, wherein 60% by mole or more of the polyamine is hydrazine.