JP2001114857A - Thermoplastic water-soluble resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic water-soluble resin with high preservation stability in the presence of water. SOLUTION: This thermoplastic water-soluble resin is composed of recurring unit of general formula (I) (R1 and R2 are each a 2-6C straight-chain or branched alkylene; R3 is a 2-6C straight-chain or branched single or mixed alkylene; Y is a polyisocyanate residue; and n and m are each an integer).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic water-soluble resin, and more particularly, to a thermoplastic water-soluble resin having a urea bond and a high hydrolysis resistance.

[0002]

2. Description of the Related Art Conventionally, water-soluble resins have been used in various fields, particularly in the field of paints. As one of such water-soluble resins, an ester compound obtained by reacting a polyol obtained by adding an alkylene oxide to a polyol and a polyvalent carboxylic acid is known (Japanese Patent Publication No.
No. 41511). This ester compound has a high molecular weight while being water-soluble, and is suitable for the above-mentioned applications.

However, the above-mentioned esterified water-soluble resin has a structure in which alkylene oxide having hydrophilicity is linked by an ester bond, so that it is susceptible to hydrolysis, and the viscosity decreases when it is blended in a paint or the like. For example, the stability upon storage in the presence of water may cause a problem.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art. It is an object of the present invention to provide a water-soluble and storage-stable storage medium in the presence of water. It is to provide a thermoplastic water-soluble resin having excellent heat resistance.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a diamine having amino groups at both ends of alkylene oxide is reacted with polyisocyanate to produce urea. It has been found that the above object can be achieved by forming a bond.

That is, it has been found that a urea bond formed by the reaction between an amino group and an isocyanate group is more excellent in hydrolysis resistance than an ester bond formed by a reaction between a hydroxyl group and a carboxyl group. Thus, the present invention has been completed. When the thermoplastic water-soluble resin of the present invention is used for a fiber sizing agent, a paint or the like, a product having excellent storage stability in the presence of water can be obtained without a decrease in viscosity or the like.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic water-soluble resin of the present invention comprises
It is a thermoplastic water-soluble resin having a repeating unit represented by the general formula (I).

[0008]

Embedded image

Here, R ¹ and R ² each have 2 carbon atoms.
To 6 linear or branched alkylene groups which may be the same or different from each other. R ³ is a straight-chain or branched C1-C6 or C2-C6 mixed alkylene group. Y is a polyisocyanate residue, that is, a portion other than the isocyanate group of the polyisocyanate. Also,
n and m are integers.

The thermoplastic water-soluble resin having a urea bond represented by Chemical Formula 2 is composed of a polyalkylenediamine represented by Chemical Formula (II) and a polyalkylene diamine represented by Chemical Formula (III). It is obtained by reacting with isocyanate.

[0011]

Embedded image

[0012]

Embedded image

Here, R ¹ , R ² ,
R ³ and Y are the same as in Chemical formula 2, and the polyalkylenediamine of Chemical formula 3 is obtained by addition-polymerizing an alkylene oxide to a compound having two hydroxyl groups, and further introducing amino groups at both ends. Specific examples of the compound having two hydroxyl groups include, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol,
6-hexanediol, neopentyl glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

The introduction of an amino group into the polyalkylene diamine of the formula (3) can be carried out by a known method. When this amino group is introduced, R ¹ and R ² are introduced.

The number n of the alkylene oxide in the chemical formula 3
Is preferably 10 to 1,000, more preferably 50 to 500, and still more preferably 90 to 500.
３５０350. If the number n of the alkylene oxide is smaller than 10, a sufficient amount of a hydrophilic group is not introduced, and the obtained resin is not water-soluble, which is not preferable. Further, those in which n is larger than 1,000 are not preferred because synthesis becomes difficult.

Further, it is necessary to select mainly the type and polymerization type of the alkylene oxide of R ³ so that the thermoplastic water-soluble resin of the present invention becomes water-soluble. Here, a case where a mixture of ethylene oxide and propylene oxide is used as R ³ will be described as an example. When a block type is used as the polymerization type, the ratio of (ethylene oxide / propylene oxide) is 6%.
It is necessary that the ratio be 0/40 or more, and when a random type is used as the polymerization type, the ratio of (ethylene oxide / propylene oxide) must be 50/50 or more. When a mixture of ethylene oxide and butylene oxide is used as R ³ , and a block type is used as the polymerization type, the ratio of (ethylene oxide / butylene oxide) is 85/1.
When the polymerization type is a random type, the ratio of (ethylene oxide / butylene oxide) needs to be 80/20 or more. Further, when a mixture of ethylene oxide and α-olefin oxide is used as R ³ ,
When the block type is used as the polymerization type, the ratio of (ethylene oxide / α-olefin oxide) is 90%.
/ 10 or more, and when a random type is used as the polymerization type, (ethylene oxide / α-
(Olefin oxide) is required to be 85/15 or more.

As the polyisocyanate shown in Chemical formula 4 used for preparing the thermoplastic water-soluble resin of the present invention, preferred are hexamethylene diisocyanate, 2,4-
Tolylene diisocyanate, 2,4-chlorophenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate,
and diisocyanates such as ω, ω '-(ditrimethylenethiol) diisocyanate. These polyisocyanates are used in the form of a reactant with a blocking agent.
Examples of the blocking agent include phenols such as phenol, cresol and thiophenol, lactams such as ε-caprolactam and valerolactam, and oximes such as acetoxime, 2-butanone oxime and cyclohexanone oxime. These blocking agents form a reactant with the polyisocyanate, and easily release the polyisocyanate when heated. The reaction product of the polyisocyanate and the blocking agent is added to the polyalkylenediamine of the above formula 3, and the polyisocyanate is released by heating in the polyalkylenediamine,
The liberated polyisocyanate immediately reacts with the polyalkylenediamine to form a urea bond.

Among the above reactants of the polyisocyanate and the blocking agent, more preferred are 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2-butanone oxime, t-butylphenol, nonylphenol, ε A reaction product in combination with caprolactam. These polyisocyanate reactants decompose at relatively low temperature into polyisocyanate and blocking agent by heating, and the released blocking agent is released outside the reaction system or partially remains in the reaction product. become.

In the reaction between the polyalkylene diamine of the formula (3) and the polyisocyanate of the formula (4), a predetermined amount of a reaction product of the polyisocyanate and the blocking agent is previously mixed with the polyalkylene diamine at a temperature lower than the decomposition temperature of the reaction product. The reaction is performed by gradually raising the temperature of the mixed reaction solution to the decomposition temperature of the reaction product. In this way, the polyisocyanate is preliminarily mixed in the form of a reaction product with the blocking agent and then heated, whereby the polyisocyanate is gradually and uniformly released into the reaction system, and the polyalkylene diamine and the polyisocyanate are mixed with each other. The local reaction is suppressed, and it is possible to avoid gelation of the reaction system.

The thermoplastic water-soluble resin of the present invention can be used by adding various additives such as an antioxidant, an antistatic agent, an inorganic filler and a colorant, if necessary.

[0021]

The present invention will be described below with reference to examples and comparative examples.

Example 1 200 parts by weight of polyoxyethylene dipropylamine (Kawaken Fine Chemical, trade name: PEO amine 6000, weight average molecular weight: about 800)
0, amine value 13.5) and HDI (hexamethylene diisocyanate, molecular weight 255) blocked with 6.9 parts by weight of 2-butanone oxime were placed in a flask.
The mixture was dissolved with stirring in an oil bath adjusted to 90 ° C.

Thereafter, the temperature of the oil bath was gradually raised to 140 ° C. while stirring, and then the reaction was carried out at this temperature for 3 hours to obtain a water-soluble resin having a 10% by weight aqueous solution having a viscosity of 150 mPs · S. When a film was produced using this water-soluble resin, it was tough and flexible.

(Example 2) 200 parts by weight of polyoxyethylene dipropylamine (Kawaken Fine Chemical, trade name: PEO amine 6000, weight average molecular weight: about 800)
0 and an amine value of 13.5) were placed in a flask and dissolved in an oil bath adjusted to 90 ° C. while stirring.

Thereafter, MDI (diphenylmethane diisocyanate, molecular weight: 337) blocked with 7.4 parts by weight of 2-butanone oxime was added, and the mixture was stirred for 4 hours while gradually increasing the temperature of the oil bath to 130 ° C. And the viscosity of the 10% by weight aqueous solution becomes 100
mPs · S water-soluble resin was obtained. When a film was produced using this water-soluble resin, it was tough and flexible.

Example 3 200 parts by weight of polyoxyethylene dipropylamine (Kawaken Fine Chemical, trade name: PEO amine 6000, weight average molecular weight: about 800)
0 and an amine value of 13.5) were placed in a flask and dissolved in an oil bath adjusted to 90 ° C. while stirring.

Thereafter, hydrogenated MDI (dicyclohexylmethane diisocyanate, molecular weight 691) blocked with 17.3 parts by weight of nonylphenol was added, and the temperature of the oil bath was gradually increased to 140 ° C. with stirring, and the reaction was carried out for 3 hours. The viscosity of a 10 wt% aqueous solution is 200 mPs
A water-soluble resin of S was obtained. When a film was produced using this water-soluble resin, it was tough and flexible.

Example 4 200 parts by weight of polyoxyethylenedipropylamine (Kawaken Fine Chemical, trade name: PEO amine 6000, weight average molecular weight: about 800)
IPDI (isophorone diisocyanate, molecular weight 516) blocked with 0, an amine value of 13.5) and 9 parts by weight of t-butylphenol were put into a flask and dissolved while stirring in an oil bath adjusted to 90 ° C.

Thereafter, the temperature of the oil bath was gradually increased to 160 ° C. while stirring, and the reaction was carried out for 3 hours.
A water-soluble resin having a 0 wt% aqueous solution viscosity of 50 mPs · S was obtained. When a film was produced using this water-soluble resin, it was tough and flexible.

Example 5 Mixed alkylene oxide of ethylene oxide and propylene oxide
Polyoxyalkylenedipropylamine (weight average molecular weight 5000, amine value 22) modified with propylamine at both ends of a diol having 15% by weight of a propylene oxide component in the chain was obtained by a conventional method. 200 parts by weight of this polyoxyalkylenedipropylamine was placed in a flask and dissolved in an oil bath adjusted to 90 ° C. while stirring.

Thereafter, TDI (tolylene diisocyanate, molecular weight 348.4) blocked with 18.2 parts by weight of 2-butanone oxime was added, and the temperature of the oil bath was gradually raised to 150 ° C. while stirring. For 3 hours to obtain a water-soluble resin having a 10% by weight aqueous solution having a viscosity of 180 mPs · S. When a film was produced using this water-soluble resin, it was tough and flexible.

Example 6 Mixture of Ethylene Oxide and Butylene Oxide Both ends of a diol having alkylene oxide and a 7% by weight of butylene oxide component in the chain were modified with propylamine in a conventional manner. The obtained polyoxyalkylene dipropylamine (weight average molecular weight 20,000, amine value 5.5) was obtained. XDI (xylylene diisocyanate, molecular weight 3) blocked with 200 parts by weight of this polyoxyalkylenedipropylamine and 3.5 parts by weight of 2-butanone oxime
66.2) was placed in a flask and dissolved in an oil bath adjusted to 90 ° C. while stirring.

Thereafter, the temperature of the oil bath was gradually increased to 150 ° C. with stirring, and the reaction was carried out for 3 hours.
A water-soluble resin having a 0% by weight aqueous solution viscosity of 160 mPs · S was obtained. When a film was produced using this water-soluble resin, it was tough and flexible.

Comparative Example 1 200 parts by weight of polyethylene oxide (weight average molecular weight: about 8,000) was placed in a flask, and dissolved and dehydrated for 90 minutes using an oil rotary pump while stirring in an oil bath adjusted to 110 ° C. Was.

Thereafter, 4.9 parts by weight of dimethyl terephthalate was added, and the mixture was stirred while gradually raising the temperature of the oil bath to 170 ° C., and subjected to a reduced pressure reaction for 4 hours to 0.1 Torr or less. Has a viscosity of 80
mPs · S water-soluble resin was obtained.

(Comparative Example 2) 200 parts by weight of polyethylene oxide (weight average molecular weight: about 8,000) was placed in a flask, and dissolved and dehydrated for 90 minutes using an oil rotary pump while stirring in an oil bath adjusted to 110 ° C. .

Thereafter, 6.2 parts by weight of dimethyl sebacate was added, and the mixture was stirred while the temperature of the oil bath was gradually raised to 170 ° C., and the reaction was carried out under reduced pressure for 4 hours to 0.1 Torr or less. The viscosity of the aqueous solution is 100mP
An s · S water-soluble resin was obtained.

(Comparative Example 3) 200 parts by weight of polyethylene oxide (Kawaken Fine Chemical, trade name: PEO amine 6000, weight average molecular weight: about 8,000, amine value: 1)
3.5) was placed in a flask, and dissolved in an oil bath adjusted to 110 ° C. while stirring.

Thereafter, 59.4 parts by weight of MDI (diphenylmethane diisocyanate, molecular weight 250) was added,
When stirring was performed while gradually raising the temperature of the oil bath to 140 ° C., the entire reaction solution was thickened and gelled.

(Initial Performance Test) With respect to the water-soluble resins obtained in the respective Examples and Comparative Examples, the viscosity of the aqueous solution, the melt viscosity, and the film strength (elongation / tensile strength) were examined. The test method is as follows.

<Aqueous Solution Viscosity> According to JIS K 7117 (viscosity test method of liquid resin by rotational viscometer), a 10% by weight aqueous solution of the resin of each example and each comparative example was prepared, and a B-type rotational viscometer was prepared. The viscosity was measured at 30.degree.

<Melt Viscosity> 1.5 g of the resin of each example and each comparative example was heated and melted at 100 ° C., and at this temperature, a flow tester (model number CFT-50 manufactured by Shimadzu Corporation) was used.
The viscosity was measured using OA).

<Film strength> JIS K 7113
According to (Plastic tensile test method), the resin of each Example and each Comparative Example was hot pressed at 100 ° C. to prepare a sample having a film thickness of 50 μm. The elongation and tensile strength of this film were determined using an autograph (manufactured by Shimadzu Corporation).

Table 1 shows the test results.

[0045]

[Table 1]

(Aging Test) With respect to the water-soluble resins obtained in the respective Examples and Comparative Examples obtained above, a viscosity aging test in an aqueous solution state was performed. The test method is JIS K7
117 (viscosity test method of liquid resin by rotational viscometer)
And the viscosity was measured at 30 ° C. using a B-type rotational viscometer at an aqueous solution concentration of 10% by weight. The storage temperature is room temperature. For each water-soluble resin, the viscosity of the aqueous solution at the start of the measurement was taken as 100%, and the extent to which the viscosity decreased with the passage of storage days was measured. The results are shown in Table 2. Also,
FIG. 1 shows the change in viscosity for Examples 1 and 2 and Comparative Example 1.

[0047]

[Table 2]

From the results shown in Table 1, the test results of the water-soluble resins of Examples 1 to 6 and Comparative Examples 1 and 2 are almost the same. However, as is clear from Table 2 and FIG.
6 is very small, while Comparative Examples 1 and 2 are very large.

[0049]

As described above, since the thermoplastic water-soluble resin of the present invention has a structure in which alkylene oxides, which are hydrophilic groups, are linked by urea bonds, the stability in the presence of water is low. Very good. Therefore, when a product such as an aqueous paint is prepared using the thermoplastic water-soluble resin of the present invention, a product that can be stored for a long time can be obtained. Also, good moldability can be obtained in resin processing methods such as film formation and injection molding.

[Brief description of the drawings]

FIG. 1 is a graph showing changes in viscosity for Examples 1 and 2 and Comparative Example 1.

Claims (4)

[Claims] 1. A thermoplastic water-soluble resin having a repeating unit represented by the general formula (I). Embedded image Here, R ¹ and R ² are each a straight-chain or branched alkylene group having 2 to 6 carbon atoms and may be the same or different from each other, and R ³ is a straight-chain or branched alkyl group having 2 to 6 carbon atoms. Single or two or more mixed alkylene groups, Y is a polyisocyanate residue, and n and m are integers. 2. The thermoplastic water-soluble resin according to claim 1, wherein the weight-average molecular weight of the thermoplastic water-soluble resin is 30,000 to 300,000. 3. In the general formula (I) of the above formula 1, n is 1.
3. The thermoplastic water-soluble resin according to claim 1, which is in a range of 0 to 1,000. 4. In the above general formula (I), m is 3
The thermoplastic water-soluble resin according to any one of claims 1 to 3, wherein the range is from 60 to 60.