JPS6410549B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel aqueous dispersion solution of a urethane-modified vinyl polymer and a method for producing the same.
It has excellent stability and can form a film with excellent water resistance and weather resistance, and can be used for example in water-based paints, water-based inks, water-based coating agents, processing agents for paper and fibers, dispersants, etc. The present invention provides an aqueous dispersion solution that can be used as a dispersion solution.

Aqueous dispersion solutions of urethane polymers include polyurethane dispersed in water using an emulsifier or dispersant, or polyurethane with hydrophilic groups (including ionic groups) introduced into the polyurethane chain in advance. Although there are dispersed solutions, all of the conventionally used aqueous dispersions have the disadvantage that they have insufficient stability and the films formed have poor water resistance and weather resistance.

In contrast, the first invention comprises a vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom, and a urethane prepolymer having an average of 1 to 1.5 terminal isocyanate groups per molecule. A urethane-modified vinyl polymer consisting of a reaction product with a basic tertiary nitrogen atom content of 0.4
By creating an aqueous dispersion of a urethane-modified vinyl polymer in which a urethane-modified vinyl polymer of milliequivalents/g or more is dispersed in an aqueous solvent containing an acidic substance, the above-mentioned drawbacks can be avoided. This makes it possible to provide an aqueous dispersion solution of a urethane-modified vinyl polymer.

The second invention also provides the above-mentioned method of combining a vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom, and a urethane prepolymer having an average of 1 to 1.5 terminal isocyanate groups per molecule. By heating and reacting in an organic solvent that has a dissolving effect on both the vinyl polymer and the urethane prepolymer, but does not show reactivity with the functional groups of each polymer, A step of producing a urethane-modified vinyl polymer having a basic tertiary nitrogen atom content of 0.4 meq/g or more, and a step of producing a urethane-modified vinyl polymer obtained by the above step,
A step of obtaining an aqueous dispersion solution of a urethane-modified vinyl polymer by dispersing it in an aqueous solvent containing an acidic substance,
The present invention provides a method for efficiently, reliably, and easily obtaining the aqueous dispersion of the urethane-modified vinyl polymer of the invention.

In the present invention, the basic tertiary nitrogen atom content of the urethane-modified vinyl polymer used is
An essential constituent requirement is 0.4 milliequivalent/g or more. This means that when the basic tertiary nitrogen atom content of the urethane-modified vinyl polymer used is less than 0.4 milliequivalents/g, an aqueous dispersion solution with sufficient stability for the purpose of the present invention can be obtained. This is because it becomes impossible to do so. On the other hand, the upper limit of the basic tertiary nitrogen atom content of the polymer is not particularly limited, but if the basic tertiary nitrogen atom content is extremely large, There is a tendency for the water resistance of the coating film formed from the aqueous dispersion solution using to be reduced.

A vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom can be copolymerized with a monomer having a hydroxyl group, a monomer having a basic tertiary nitrogen atom, and these monomers. It can be easily produced by copolymerizing other monomers.

Examples of monomers having a hydroxyl group include hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, and allyl Alcohols, hydroxystyrenes, etc., and monomers having a basic tertiary nitrogen atom include, for example, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylamino Examples include propyl (meth)acrylate and vinylpyridine. Further, other monomers that can be copolymerized with these monomers include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate. ) Alkyl (meth)acrylates such as acrylates, vinyl esters such as vinyl acetate and vinyl propionate, aromatic monovinyl compounds such as styrene and vinyltoluene, vinyl ethers,
Allyl ethers etc. can be used.

Regarding each of the above monomers having a hydroxyl group, monomers having a basic tertiary nitrogen atom, and other monomers that can be copolymerized with these monomers, even if the respective single compounds are Of course, it is possible to use the compound in the form of a mixture of several kinds of compounds.

When obtaining this vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom, a monomer having a hydroxyl group, a monomer having a basic tertiary nitrogen atom,
And as each of the other monomers copolymerizable with these monomers, (meth)acrylic monomers are selected and used, and vinyl having a hydroxyl group and a basic tertiary nitrogen atom is selected and used. When an acrylic polymer is obtained as a system polymer, the urethane-modified vinyl polymer obtained by reacting it with a urethane prepolymer having terminal isocyanate groups has the characteristic of having particularly excellent weather resistance. have

The vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom is composed of each of the above-mentioned monomers, that is, a monomer having a hydroxyl group, a monomer having a basic tertiary nitrogen atom, and a monomer having a basic tertiary nitrogen atom. Other monomers that can be copolymerized with the monomer are subjected to conventional polymerization operations such as bulk polymerization,
A urethane prepolymer having a terminal isocyanate group that is easily produced by subjecting it to a polymerization operation such as suspension polymerization, emulsion polymerization, or solution polymerization, and which is particularly reacted with the obtained vinyl polymer at a later stage. ester solvents such as acetate esters and formate esters; ketone solvents such as acetone and methyl ethyl ketone; Utilizing a solution polymerization reaction using a solvent such as dimethylformamide or dimethyl sulfoxide is a step in which the obtained vinyl polymer is reacted with another reaction component, a urethane prepolymer having terminal isocyanate groups. This is convenient in terms of operational steps, since the solution of the vinyl polymer can be used as it is.

Vinyl type obtained by copolymerization of a monomer having a hydroxyl group, a monomer having a basic tertiary nitrogen atom, and another monomer copolymerizable with these monomers according to the present invention Regarding the polymer, the amount of hydroxyl groups contained in the vinyl polymer is not particularly limited, but due to the reactivity with the urethane prepolymer having terminal isocyanate groups, which is another reactive component. , that is,
If the hydroxyl value is small, the amount of urethane prepolymer that reacts with the vinyl polymer will be relatively small, making it impossible to obtain an aqueous dispersion solution having the ability to form a film with the properties targeted by the present invention. Therefore, it is desirable that the hydroxyl value is 30 mgKOH/g or more. On the other hand, if the hydroxyl value contained in the vinyl polymer is high, the urethane prepolymer can be reacted with only a portion of the hydroxyl groups in the vinyl polymer, so the resulting urethane-modified vinyl polymer can be reacted with the urethane prepolymer. The unreacted hydroxyl groups in the combination have the effect of further improving the stability of the aqueous dispersion of the polymer. However, if the hydroxyl value is high, for example 200mgKOH/g or more, the water resistance of the coating film formed from the aqueous dispersion solution will decrease.
It is desirable that it is 200mgKOH/g or less.

On the other hand, the basic tertiary nitrogen atom contained in the vinyl polymer having the hydroxyl group and the basic tertiary nitrogen atom
The amount of tertiary nitrogen atoms is directly related to the content of basic tertiary nitrogen atoms in the urethane-modified vinyl polymer, which is the reaction product with the urethane prepolymer having terminal isocyanate groups, which is another reaction component mentioned above. Therefore, the content of basic tertiary nitrogen atoms is such that the content of basic tertiary nitrogen atoms in the resulting urethane-modified vinyl polymer is 0.4 milliequivalents/g or more, that is, the content of basic tertiary nitrogen atoms. It is desirable that the amount is 0.5 milliequivalent/g or more.

The urethane prepolymer reacted with the vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom is a urethane prepolymer having an average of 1 to 1.5 terminal isocyanate groups per molecule. Preference is given to using urethane prepolymers obtained by reaction of compounds with polyisocyanate compounds.

Specific examples of polyhydroxy compounds include:
Polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide block copolymer, polyether polyols such as poly(tetramethylene ether) polyol, polyester polyols, ethylene glycol, 1,4-butanediol, 1,
Alkylene glycols such as 6-hexanediol can be used alone or in mixtures. Further, specific examples of polyisocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate,
Isophorone diisocyanate or prepolymers thereof can be used alone or in mixtures.

When obtaining a urethane prepolymer, a urethane prepolymer having isocyanate groups at both ends can be obtained by reacting a dihydroxy compound and a diisocyanate compound with an appropriate excess proportion of isocyanate groups, or a trifunctional or higher functional polyhydroxy compound or polyisocyanate compound. By reacting, a urethane prepolymer having three or more terminal isocyanate groups can be obtained, but if these urethane prepolymers are reacted with the above-mentioned vinyl polymer, there is a disadvantage that gelation occurs due to crosslinking reaction. In such cases, the number of terminal isocyanate groups in the urethane prepolymer must be kept within the range of 1 to 1.5 on average by using a blocking agent. This blocking agent can be used at any stage when reacting a polyhydroxy compound and a polyisocyanate compound to obtain a urethane prepolymer, or when reacting the obtained urethane prepolymer with a vinyl polymer. . This blocking agent can be one having one functional group reactive with isocyanate groups, such as alcohols, phenols, thiols, amines, etc. When used to obtain a urethane prepolymer, It is preferable to obtain a urethane prepolymer by using a suitable solvent and a suitable urethanization reaction catalyst and performing a normal polyurethane synthesis reaction.

The urethane-modified vinyl polymer used in the present invention is a vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom as described above, and an average of 1 to 1.5 terminal isocyanate groups per molecule. It consists of a reaction product obtained by reacting a urethane prepolymer with
Basic tertiary nitrogen atom content is 0.4 meq/g
The vinyl polymer and urethane prepolymer are mixed at a desired mixing ratio, preferably, the terminal isocyanate group in the urethane prepolymer is 1 equivalent or less per 1 equivalent of hydroxyl group in the vinyl polymer, particularly, It can be easily obtained by mixing the two at an equivalent ratio of 1 to 1/5 and subjecting the resulting mixture to a heating reaction.

In this reaction between the vinyl polymer and the urethane prepolymer, the terminal isocyanate group of the urethane prepolymer preferentially reacts with the hydroxyl group of the vinyl polymer, and the urethane modified with a basic tertiary nitrogen atom in the present invention A vinyl polymer is obtained, but the reaction between the vinyl polymer and the urethane prepolymer is such that both of these reaction components are uniformly dissolved, and the functional groups of each reaction component are reactive. It is preferable to carry out the reaction in a solvent that does not exhibit , since the reaction can proceed smoothly. The end point of the reaction is the point at which the free isocyanate groups contained in the reaction mixture are substantially exhausted, but the presence of small amounts of free isocyanate groups in the reaction product does not pose any particular hindrance. In addition, the above-mentioned blocking agent can be added if necessary.

The aqueous dispersion solution of the urethane-modified vinyl polymer of the present invention is such that the urethane-modified vinyl polymer having a basic tertiary nitrogen atom content of 0.4 meq/g or more as explained above is It is dispersed in an aqueous solvent, ie, water or a mixture of water and a hydrophilic solvent, containing an amount of an acidic substance capable of at least partially neutralizing the basic tertiary nitrogen atoms in the coalescence.

An aqueous dispersion solution in which the above-mentioned urethane-modified vinyl polymer is dispersed in water containing an acidic substance or an aqueous solvent consisting of water and a hydrophilic solvent is a mixture of the urethane-modified vinyl polymer in an aqueous solvent. However, it can be obtained by adding an acidic substance to this, or by mixing the urethane-modified vinyl polymer in an aqueous solvent to which an acidic substance has been added in advance. In addition, as a urethane-modified vinyl polymer,
When using a solvent solution of the polymer, similarly, this solvent solution is mixed as it is in an aqueous solvent, and then an acidic substance is added to this mixed solution, or
Alternatively, a solvent solution of a urethane-modified vinyl polymer is mixed in an aqueous solvent to which an acidic substance has been added in advance, and the resulting mixed solution is then subjected to vacuum distillation to remove the organic solvent in the mixed solution. However, especially in the former method, in which the solvent solution of the urethane-modified vinyl polymer is mixed directly into the aqueous solvent, the vacuum distillation operation for removing the organic solvent is performed by adding the solvent to the mixed solution. The step may be carried out before adding the acidic substance, or separately in both steps before and after adding the acidic substance.

As mentioned above, the acidic substance present in the aqueous dispersion of the urethane-modified vinyl polymer of the present invention is the basic tertiary substance in the urethane-modified vinyl polymer.
The urethane-modified vinyl polymer is made to have dispersibility in an aqueous solvent by at least partially neutralizing nitrogen atoms.
As this acidic substance, inorganic and organic acidic substances such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, propionic acid, etc. can be used.
In particular, when a volatile acidic substance such as hydrochloric acid, formic acid, or acetic acid is used, the resulting aqueous dispersion has the characteristic that when it is made into a film, the acidic substance evaporates, resulting in a film with excellent water resistance. is obtained.

The aqueous dispersion of the urethane-modified vinyl polymer of the present invention having the above-mentioned structure can also be used by further quaternizing the urethane-modified vinyl polymer with a suitable quaternizing agent.

As mentioned above, the aqueous dispersion of the urethane-modified vinyl polymer of the first invention includes a vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom,
A urethane-modified vinyl polymer having a basic tertiary nitrogen atom content of 0.4 milliequivalents/g or more, which is a reaction product with a urethane prepolymer having an average of 1 to 1.5 terminal isocyanate groups per molecule,
It is dispersed in an aqueous solvent containing an acidic substance.

Therefore, in the aqueous dispersion solution of the urethane-modified vinyl polymer of the first invention, a polymer in which a urethane prepolymer chain is graft-polymerized to a vinyl polymer, that is, a base contained in the polymer is used. The polymer has excellent self-dispersibility in water due to the tertiary nitrogen atom, and stability in water due to the polyurethane segment being protected by a stable vinyl polymer. A water-soluble or water-dispersible polymer with It has extremely excellent effects in terms of sex.

Furthermore, the aqueous dispersion solution of the urethane-modified vinyl polymer of the first invention has excellent water resistance and weather resistance because the acidic substance in the dispersion solution is volatilized when a film is formed by the dispersion solution. This results in a film that has additional effects.

Note that the film exhibits a special effect of being able to be redispersed in water using an aqueous solvent containing an acidic substance.

Further, the method for producing an aqueous dispersion solution of a urethane-modified vinyl polymer according to the second invention includes: a vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom;
A urethane prepolymer having an average of 1 to 1.5 terminal isocyanate groups per molecule has a dissolving effect on both the vinyl polymer and the urethane prepolymer, but it has a dissolving effect on the functional groups of each polymer. A urethane-modified vinyl polymer having a basic tertiary nitrogen atom content of 0.4 milliequivalents/g or more is produced by carrying out a heating reaction in an organic solvent that does not show reactivity, and then , the urethane-modified vinyl polymer obtained above is dispersed in an aqueous medium containing an acidic substance.

Therefore, since the method for producing an aqueous dispersion of a urethane-modified vinyl polymer according to the second aspect of the present invention utilizes a polymerization reaction in which the reaction is carried out in a solvent, the polymerization reaction proceeds smoothly. The aqueous dispersion solution of the first invention has the effect that it can be obtained reliably and easily.

Hereinafter, the aqueous dispersion of the urethane-modified vinyl polymer of the present invention, the functions and effects of the solution, and examples of the method for producing the solution will be described based on Examples and Comparative Examples.

Example 1 (i) Production of a vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom 200 g of ethyl acetate was placed in a 500 ml four-necked flask.
The temperature is raised and maintained at reflux temperature. While passing nitrogen gas, add 40 g of dimethylaminoethyl methacrylate, 40 g of 2-hydroxyethyl acrylate, and 2-ethylhexyl acrylate.
20g, methyl methacrylate 60g, styrene 40g
206 g of a mixed monomer solution consisting of 1.5 g, 2 g of lauryl mercaptan, and 4 g of azobisisobutyronitrile was added dropwise over 3 hours. After the dropwise addition was completed, the temperature was maintained for an additional 4 hours to obtain 393 g of an ethyl acetate solution of vinyl polymer A.

The obtained vinyl polymer A had a hydroxyl value of 94 mg.
KOH/g, basic tertiary nitrogen atom content 1.24
milliequivalent/g.

(ii) Production of urethane prepolymer having terminal isocyanate groups: Add 100 ml of ethyl acetate to a 500 ml four-necked flask.
g, polyethylene glycol (molecular weight 200)
46.6 g of tolylene diisocyanate (TDI) was added dropwise at room temperature. After the exotherm stopped, the reaction was carried out at 40 to 50°C for 1 hour, and then 2.7 g of ethanol was added and the reaction was carried out at the same temperature for an additional 1 hour. Followed by dibutyltin dilaurate 0.06
After the heat generation has stopped, the reaction is carried out at 50 to 60°C for about 1 hour to form an ethyl acetate solution of urethane prepolymer B having terminal isocyanate groups.
Got 200g. The reaction component ratio of this urethane prepolymer B is polyethylene glycol:
TDI:ethanol=4:5:1 (molar ratio), and has one terminal isocyanate group on average.

(iii) Production of urethane-modified vinyl polymer In a 500 ml four-necked flask, add 71.5 g of the ethyl acetate solution of vinyl polymer A obtained in section (i) above and the terminals obtained in section (ii) above. A solution of urethane prepolymer B having an isocyanate group (75 g) in ethyl acetate was charged and reacted at 40 to 50°C for 1 hour, and then heated to 70 to 80°C for 2 hours. Then, add 4g of ethanol and
The reaction was carried out for 30 minutes to obtain an ethyl acetate solution of urethane-modified vinyl polymer C.

The reaction ratio of urethane prepolymer/vinyl polymer in this reaction is approximately 1/1 by weight,
The equivalent ratio of NCO/OH was approximately 1/2.87, and the basic tertiary nitrogen atom content of the obtained urethane-modified vinyl polymer C was 0.62 meq/g.

(iv) Preparation of aqueous dispersion solution of urethane-modified vinyl polymer The ethyl acetate solution of urethane-modified vinyl polymer C obtained in the above (iii) was subjected to a distillation operation to distill off a portion of the ethyl acetate. did. Next, 3.6 g of acetic acid with a concentration of 90% and 171 g of water were added, thoroughly stirred and dispersed, and then distilled under reduced pressure at about 70°C for 1 hour.
The remaining ethyl acetate was distilled off, further diluted with water,
An aqueous dispersion solution (PH4.65) of a urethane-modified vinyl polymer with a polymer concentration of 30% was obtained.

The stability of the obtained aqueous dispersion of the urethane-modified vinyl polymer is very good, and the film obtained by coating this dispersion on a glass plate and drying it is colorless and transparent, and has water resistance and It had excellent weather resistance.

Example 2 (i) Production of a vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom The ethyl acetate solution of the vinyl polymer A in item (i) of Example 1 is used.

(ii) Production of urethane prepolymer having terminal isocyanate groups The ethyl acetate solution of urethane prepolymer B in section (ii) of Example 1 was used.

(iii) Production of urethane-modified vinyl polymer 47.7 g of an ethyl acetate solution of vinyl polymer A in item (i) above, 100 g of an ethyl acetate solution of urethane prepolymer B in item (ii) above, and 5.4 g of ethanol. Using the same procedure as in section (iii) of Example 1, an ethyl acetate solution of urethane-modified vinyl polymer D was obtained.

The reaction ratio of urethane prepolymer/vinyl polymer in this reaction is approximately 2/1 by weight,
The equivalent ratio of NCO/OH was approximately 1/1.44, and the basic tertiary nitrogen atom content of the obtained urethane-modified vinyl polymer D was 0.41 meq/g.

(iv) Preparation of an aqueous dispersion solution of urethane-modified vinyl polymer Using 2.4 g of acetic acid with a concentration of 90% and 173 g of water, an ethyl acetate solution of urethane-modified vinyl polymer D obtained in section (iii) above was prepared. The same procedure as described in Section (iv) of Example 1 was carried out to obtain an aqueous dispersion solution (PH4.6) of a urethane-modified vinyl polymer having a polymer concentration of 30%.

The stability of the obtained aqueous dispersion of the urethane-modified vinyl polymer was very good, and the film obtained by coating and drying this dispersion on a glass plate had excellent water resistance and weather resistance. It was hot.

Example 3 (i) Production of a vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom In the operation in item (i) of Example 1, 80 g of dimethylaminoethyl methacrylate, 2- Hydroxyethyl acrylate 40g, 2-ethylhexyl acrylate 20g
g, methyl methacrylate 60g, lauryl mercaptan 2g, azobisisobutyronitrile 4g
395 g of an ethyl acetate solution of vinyl polymer E was obtained by carrying out the same procedure as in section (i) of Example 1, except for using a mixed monomer solution consisting of 1.

The obtained vinyl polymer E had a hydroxyl value of 94 mg.
KOH/g, basic tertiary nitrogen atom content 2.47
milliequivalent/g.

(ii) Production of urethane prepolymer having terminal isocyanate groups In a 500 ml four-necked flask, add 100 ml of ethyl acetate.
g, polyethylene glycol (molecular weight 300)
After preparing 56.7g, mixing and dissolving it uniformly,
41.1g of TDI was added dropwise at room temperature, and (ii) of Example 1 was added below.
In the same manner as described above, 200 g of an ethyl acetate solution of urethane prepolymer F having terminal isocyanate groups was obtained using 2.2 g of ethanol and 0.06 g of dibutyltin dilaurate.

The reaction component ratio of the obtained urethane prepolymer F was polyethylene glycol:TDI:ethanol=4:5:1 (molar ratio), and it had one terminal isocyanate group on average.

(iii) Production of urethane-modified vinyl polymer 95.9 g of an ethyl acetate solution of vinyl polymer E obtained in section (i) above, and an ethyl acetate solution of urethane prepolymer F also obtained in section (ii) above. 50g
The same operation as in item (iii) in Example 1 was performed using 2.2 g of ethanol to obtain an ethyl acetate solution of urethane-modified vinyl polymer G.

The reaction ratio of urethane prepolymer/vinyl polymer in this reaction is approximately 1/2 by weight,
The equivalent ratio of NCO/OH was approximately 1/7.1, and the basic tertiary nitrogen atom content of the obtained urethane-modified vinyl polymer G was 1.65 meq/g.

(iv) Preparation of aqueous dispersion solution of urethane-modified vinyl polymer Using 9.5 g of acetic acid with a concentration of 90% and 216 g of water, an ethyl acetate solution of urethane-modified vinyl polymer G obtained in the above (iii) was prepared. The same procedure as described in Section (iv) of Example 1 was carried out to obtain an aqueous dispersion solution (PH5.2) of a urethane-modified vinyl polymer having a polymer concentration of 25%.

The stability of the obtained aqueous dispersion of the urethane-modified vinyl polymer is very good, and the dry film obtained by coating this dispersion on a glass plate is colorless and transparent, and has good water resistance and weather resistance. It was excellent.

Comparative Example (i) Production of a vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom In the operation in section (i) of Example 1, 20 g of dimethylaminoethyl methacrylate, 2-hydroxy 40g of ethyl acrylate, 20g of 2-ethylhexyl acrylate
g, methyl methacrylate 80g, styrene 40g
392 g of an ethyl acetate solution of vinyl polymer H was prepared by following the same procedure as in section (i) of Example 1, except for using a mixture consisting of
I got it.

The obtained vinyl polymer H had a hydroxyl value of 94 mg.
KOH/g, basic tertiary nitrogen atom content 0.62
milliequivalent/g.

(ii) Production of urethane prepolymer having terminal isocyanate groups The ethyl acetate solution of urethane prepolymer B in section (ii) of Example 1 was used.

(iii) Production of urethane-modified vinyl polymer 85.6 g of an ethyl acetate solution of vinyl polymer H obtained in the above (i), 60 g of an ethyl acetate solution of the urethane prepolymer B also obtained in the above (ii), and Using 3.2 g of ethanol, (iii) in Example 1
An ethyl acetate solution of urethane-modified vinyl polymer I was obtained by carrying out the same operation as in section 2.

The reaction ratio of urethane prepolymer/vinyl polymer in this reaction is approximately 1/1.5 by weight.
The equivalent ratio of NCO/OH is about 1/4.31, and the basic tertiary
The nitrogen atom content was 0.37 meq/g.

(iv) Preparation of an aqueous dispersion solution of urethane-modified vinyl polymer Using 2.2 g of acetic acid with a concentration of 90% and 173 g of water, an ethyl acetate solution of urethane-modified vinyl polymer I obtained in the above (iii) was prepared. The same procedure as described in Section (iv) of Example 1 was carried out to obtain an aqueous dispersion (PH4.35) of a urethane-modified vinyl polymer having a polymer concentration of 30%.

After leaving the obtained aqueous dispersion of the urethane-modified vinyl polymer for 24 hours, we observed its stability. As a result, a large amount of precipitated substances were generated in the dispersion, and its stability was poor. There was found. Further, the film obtained by applying this dispersion solution onto a glass plate and drying it was cloudy.

Claims (1)

[Scope of Claims] 1. A vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom, and an average of 1 to 1 per molecule.
A urethane-modified vinyl polymer, which is a reaction product with a urethane prepolymer having 1.5 terminal isocyanate groups and has a basic tertiary nitrogen atom content of 0.4 meq/g or more, is added to an aqueous solvent containing an acidic substance. An aqueous dispersion solution of a urethane-modified vinyl polymer. 2 The vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom has a hydroxyl value of 30 to 200 mgKOH/g.
An aqueous dispersion solution of a urethane-modified vinyl polymer according to claim 1, which is an acrylic polymer. 3. Claim 1, wherein the vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom is a vinyl polymer having a basic tertiary nitrogen atom content of 0.5 milliequivalent/g or more. Or an aqueous dispersion solution of the urethane-modified vinyl polymer according to item 2. 4 A vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom, and an average of 1 to 1 per molecule.
urethane prepolymer having a terminal isocyanate group of 1.5, has a dissolving effect on both the vinyl polymer and the urethane prepolymer, but does not show reactivity with the functional groups of each polymer. By carrying out a heating reaction in an organic solvent, a urethane-modified vinyl polymer having a basic tertiary nitrogen atom content of 0.4 milliequivalents/g or more is produced, and then the obtained urethane-modified vinyl is A method for producing an aqueous dispersion solution of a urethane-modified vinyl polymer, which comprises dispersing the polymer in an aqueous solvent containing an acidic substance. 5 The vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom has a hydroxyl value of 30 to 200 mgKOH/g.
A method for producing an aqueous dispersion of a urethane-modified vinyl polymer according to claim 4, which is a vinyl polymer. 6 Claim 4, wherein the vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom is a vinyl polymer having a basic tertiary nitrogen atom content of 0.5 milliequivalent/g or more. Alternatively, the method for producing an aqueous dispersion of a urethane-modified vinyl polymer according to item 5. 7 A vinyl polymer having a hydroxyl group and a basic tertiary nitrogen atom and a urethane prepolymer having a terminal isocyanate group are mixed in an organic solvent,
The urethane according to claim 4, 5, or 6, wherein the urethane is heated at a reaction ratio of 1 to 5 equivalents of hydroxyl groups in the vinyl polymer to 1 equivalent of terminal isocyanate groups in the urethane prepolymer. A method for producing an aqueous dispersion of a modified vinyl polymer. 8. An aqueous dispersion solution of a urethane-modified vinyl polymer according to claim 4, 5, 6, or 7, wherein the acidic substance in the aqueous solvent is formic acid, acetic acid, hydrochloric acid, or a mixture thereof. Production method.