JP3133256B2 - Modified polyvinyl alcohol-based copolymer, method for producing the same, and coating composition for plasticized vinyl chloride-based resin molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl alcohol (hereinafter simply referred to as PVA) copolymer and a coating composition for a plasticized vinyl chloride resin (hereinafter simply referred to as PVC) molded article. Prevents plasticizer bleed-out (surface migration) of the product to prevent contamination of the molded product surface, and provides excellent surface properties such as blocking resistance, mold release, water repellency, printability, and weather resistance. The present invention relates to a modified PVA-based copolymer suitable for providing a plasticized PVC molded article having excellent flexibility, adhesiveness and the like, and a coating composition for the plasticized PVC molded article comprising the copolymer.

[0002]

2. Description of the Related Art Conventionally, PVC is a resin which is inexpensive and has excellent chemical stability, and can be used for manufacturing a wide range of molded products from hard to soft by changing the amount of plasticizer added. For example, wallpaper, interior materials such as floor and ceiling materials, agricultural sheets, tents, sheets such as canvas, hoses,
It is used in many applications as various molded products such as tubes.

However, a plasticized PVC molded article contains a large amount of a plasticizer, and has a drawback such that the plasticizer bleeds out to the surface thereof with the passage of time, causing dirt to adhere to the surface and blocking. Various methods have been conventionally studied to prevent the plasticizer in the plasticized PVC molded article from bleeding out to the surface thereof.

Japanese Patent Publication No. 47-28740 proposes providing a resin coating layer on the surface of a plasticized PVC molded article in order to suppress the migration of a plasticizer. As a resin for forming such a resin coating layer, a homopolymer of an acrylate ester or a methacrylate ester, a copolymer of these monomers, and the like are known, and these polymers or copolymers are known. In the film made of the coalesced product, the plasticizer does not completely prevent the bleach-out, and the molded product cannot satisfy various properties such as stain resistance, blocking resistance, and bending resistance.

[0005] JP-A-2-29938 discloses PV
It has been shown that by forming a coating film containing a fluorinated copolymer having a crosslinked site and an acrylic copolymer as a main component on a C sheet, a sheet having excellent adhesion of the coating film is provided. However, the coating film has a low ability to prevent the plasticizer from bleeding out.

[0006] PVA is a resin excellent in solvent resistance, coating strength, abrasion resistance, gas barrier properties, and the like, and is a preferable material from the viewpoint of preventing bleed-out of a plasticizer. Due to lack of flexibility, PV
Satisfactory, such as cracking and whitening of the film when bending such as a sheet having a film composed of A, and poor sheet blocking resistance, stain resistance, etc. under high humidity due to the high water solubility of the film. It cannot be done.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent bleed-out of a plasticizer in a plasticized PVC molded article to prevent contamination of the molded article surface, and to prevent blocking, release, and repellency. A modified PVA-based copolymer and a copolymer comprising water and excellent surface properties such as printability and suitable for providing a plasticized PVC molded article having excellent weather resistance, flexibility and adhesiveness. An object of the present invention is to provide a coating composition for a plasticized PVC molded article.

[0008]

The above object is achieved by the present invention described below. That is, the present invention relates to PVA 90 to 4
0 parts by weight and 10 to 60 parts by weight of a lactone compound capable of forming an aliphatic polyester by ring-opening polymerization.
To the OH group and the ester group to form a grafted P
No graft reaction in PVA in VA copolymer
An OH group and a terminal OH group of the above aliphatic polyester are reacted with a monoisocyanate compound having an aliphatic group having 12 or more carbon atoms, and have a number average molecular weight of 10.0 or less.
Modified PV characterized in that the number is from 500 to 500,000
An A-based copolymer, a method for producing the same, and a coating composition for a plasticized PVC molded article comprising the copolymer.

In particular, the PVA includes vinyl acetate.
Those having a saponification degree of 60 mol% or more are preferable.
As the aliphatic polyester, an aliphatic polyester composed of polycaprolactone or polyvalerolactone is preferable. Conventionally, an ester compound and a polyester-based resin have been used for plasticizing a PVC molded product, and it is apparent that ester bonds generally contribute to plasticization and compatibility of PVC.

Therefore, the present inventor has proposed that by introducing an ester bond into PVA, the plasticized PVC molding having the gas barrier properties of PVA and having the adhesion to the plasticized PVC molded article and the flexibility of the coating film can be obtained. The present inventors have conducted intensive studies on coating compositions for products and have completed the present invention.

A urethane-modified PVA-based copolymer obtained by reacting a PVA-based copolymer obtained by grafting an aliphatic polyester onto PVA with a monoisocyanate compound having an aliphatic group having 12 or more carbon atoms is obtained by plasticizing. Prevents bleed-out of plasticizer in vinyl chloride resin molded products, and imparts excellent surface properties such as blocking resistance, release properties, water repellency, printability, and weather resistance, flexibility,
A coating composition for a plasticized PVC molded article having excellent adhesiveness and the like can be provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to embodiments. The urethane-modified PVA-based copolymer of the present invention comprises a P on which an aliphatic polyester is grafted.
It is obtained by reacting a hydroxyl group in a VA copolymer with a monoisocyanate compound having an aliphatic group having 12 or more carbon atoms.

First, a PVA-based copolymer is obtained by adding ε to PVA.
It can be obtained by ring-opening graft copolymerization of a lactone compound capable of forming an aliphatic polyester by lactone ring-opening polymerization, such as a caprolactone compound and a δ-valerolactone compound. The PVA used in the present invention has a saponification degree of vinyl acetate unit of 60 mol% or more and a weight average polymerization degree of 20 to 20,000, preferably 200 to 3,000.
0 PVA.

In the present invention, the caprolactone compound to be reacted with PVA includes various compounds such as ε-caprolactone, monomethyl-ε-caprolactone, monoethyl-ε-caprolactone, monopropyl-ε-caprolactone, and monododecyl-ε-caprolactone. Monoalkyl-ε-caprolactones or dialkyl-ε-caprolactones or ε of a lactone ring in which both of the two alkyl groups are not bonded to the carbon atom at the ε-position but are each substituted on a similar separate carbon atom -The carbon atom at the position is di-
Unsubstituted trialkyl-ε-, in which two or three other carbon atoms are replaced by three alkyl groups
Alkoxy-ε-caprolactones such as caprolactone and ethoxy-ε-caprolactone or cycloalkyl-ε-caprolactone such as cyclohexyl, phenyl- and benzyl-ε-caprolactone, aryl-ε-caprolactone and aralkyl-ε-caprolactone, etc. Is mentioned.

The δ-valerolactone compound preferably used in the present invention includes 5-valerolactone, 3
-Methyl-5-valerolactone, 3,3, -dimethyl-
5-valerolactone, 2-methyl-5-valerolactone, 3-ethyl-5-valerolactone, and the like.

The reaction between PVA and the lactone compound is as follows:
Were mixed together, preferably using an appropriate catalyst under a nitrogen gas stream, is carried out by reacting for several hours to several tens hours at a temperature of from 10 to 220 ° C., the PVA, the OH group and d
A PVA-based copolymer in which a ster group is formed and an aliphatic polyester having a terminal OH group is grafted is obtained. In the above grafting reaction, by changing the molecular weight of the aliphatic polyester to be grafted onto the PVA, that is, by changing the weight ratio of the PVA and the aliphatic polyester used in the reaction, the PVA having the characteristics of the PVA and the aliphatic polyester is obtained.
A system copolymer is obtained.

The weight ratio of PVA to aliphatic polyester in the copolymer is preferably in the range of 90 to 60 parts by weight of PVA and 10 to 40 parts by weight of aliphatic polyester. PVA-based copolymer in which PVA exceeds 90 parts by weight and aliphatic polyester is less than 10 parts by weight, since the performance from PVA is dominant, the adhesion of the obtained copolymer to a plasticized PVC molded article, The effect of improving the flexibility of the coating and the solubility in the solvent is small.

On the other hand, a PVA-based copolymer containing less than 60 parts by weight of PVA and more than 40 parts by weight of aliphatic polyester is superior in performance from aliphatic polyester, so that the plasticizer has an effect of preventing bleed out. Inferior and insufficient as the coating composition for the plasticized PVC molded article of the present invention. In the present invention, graft polymerization of a lactone compound onto PVA is performed by mixing the two, preferably adding a catalyst under a nitrogen stream, and stirring at a temperature of 80 to 220 ° C. for several hours. It is also possible to carry out graft polymerization in a molten and heated state using a kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader or a Brabender.
The molecular weight of the copolymer thus obtained is about 1 as a number average molecular weight (standard polystyrene conversion) measured by GPC.
10000-50 is a man, the range of about 10,000 to 200,000 are preferred.
When the molecular weight exceeds the above range, the copolymer has insufficient moldability, while when the molecular weight is less than the above range, the copolymer has insufficient mechanical properties.

Next, the PVA-based copolymer obtained as described above is reacted with a monoisocyanate compound having an aliphatic group having 12 or more carbon atoms to thereby form the urethane-modified PVA-based copolymer of the present invention. Is obtained. The monoisocyanate compound having an aliphatic group used in the present invention can be represented by the general formula R-NCO. R in the formula is an aliphatic group having 12 or more carbon atoms, and includes an alkyl group and an alkenyl group. Examples of these monoisocyanate compounds having an aliphatic group include lauryl isocyanate (carbon number 12), myristyl isocyanate (carbon number 14), cetyl isocyanate (carbon number 16), stearyl isocyanate (carbon number 18), and oleyl isocyanate (carbon number). Formula 18), eicosanyl isocyanate (carbon number 20), docosanyl isocyanate (carbon number 2)
2), tetracosanyl isocyanate (24 carbon atoms),
Hexacosanyl isocyanate (carbon number 26), octacosanyl isocyanate (carbon number 28) and the like can be mentioned.

As the monoisocyanate compound having an aliphatic group, a monoisocyanate compound which is a reaction product of an aliphatic alcohol having 12 or more carbon atoms and a diisocyanate compound in an equimolar ratio can also be used. Examples of the aliphatic alcohol having 12 or more carbon atoms include lauryl alcohol (12 carbon atoms), myristyl alcohol (14 carbon atoms), cetyl alcohol (16 carbon atoms), and stearyl alcohol (1 carbon atom).
8), oleyl alcohol (18 carbon atoms), eicosanol (20 carbon atoms), docosanol (22 carbon atoms), tetracosanol (24 carbon atoms), hexacosanol (26 carbon atoms), octacanol (28 carbon atoms), etc. Is mentioned. Further, as the above diisocyanate compound,
Various diisocyanate compounds used as a raw material of the polyurethane resin, for example, tolylene diisocyanate and the like can be mentioned.

Next, the PVA-based copolymer and the carbon number of 1
The reaction with a monoisocyanate compound having two or more aliphatic groups will be described. After dissolving or dispersing the PVA copolymer in a molten state or in a solvent, 60 to 15
A monoisocyanate compound having an aliphatic group having 12 or more carbon atoms is reacted at a temperature of 0 ° C. At this time, the reaction ratio of the monoisocyanate compound having an aliphatic group having 12 or more carbon atoms is preferably in the range of 0.2 to 1.1 equivalents to the hydroxyl group in the PVA-based copolymer. In terms of weight ratio, it is preferable to use the monoisocyanate compound at a ratio of about 50 to 500 parts by weight reacting and binding per 100 parts by weight of the PVA-based copolymer. When the amount of the monoisocyanate compound exceeds the above-mentioned equivalent range, it is insufficient in that an excessive amount of the monoisocyanate compound remains in the reaction mixture, while the amount of the monoisocyanate compound is less than the above-mentioned equivalent range. Is insufficient in terms of water repellency and releasability of the obtained copolymer.

The reaction is completed when the absorption peak in the infrared absorption spectrum based on isocyanate groups in the reaction mixture disappears. The obtained reaction mixture is poured into a poor solvent such as alcohol 2 to 5 times to precipitate a urethane-modified product, and the precipitate is separated by filtration, and then dried and dried to obtain the urethane-modified PVA copolymer of the present invention. Get. The urethane-modified PVA copolymer thus obtained exhibits excellent solubility in solvents such as toluene and xylene, and prevents bleeding out of a plasticizer of a plasticized PVC molded product, blocking resistance, releasability, and repellency. It has excellent properties such as aqueous properties, printability, light resistance, flexibility and adhesiveness.

In the present invention, as described above, after the aliphatic polyester is graft-polymerized to PVA, the monoisocyanate compound can be easily bonded to the graft copolymer by a conventional method. It has been difficult to directly and efficiently react and bond monoisocyanate compounds having 12 or more carbon atoms. That is, PV
When A is heated to a temperature of 100 ° C. or higher, it gradually undergoes thermal decomposition, and since the softening point of PVA is high, it is difficult to efficiently react with the monoisocyanate compound in a substantially anhydrous or non-plasticized state. Met.

On the other hand, in the present invention, at the time of the initial graft polymerization reaction, when the PVA and the lactone compound are in a mixed state, the white powdered PVA and the liquid lactone compound are in an inhomogeneous state. With white powder P
VA changes to a uniform reaction product, and despite the high temperature, no thermal decomposition of unreacted PVA is observed. In the subsequent reaction with the monoisocyanate compound, the same applies to PVA (aliphatic polyester). Modified product) has a low melting point and is easily dissolved in an organic solvent, so that PVA was easily modified with a monoisocyanate compound without thermal decomposition of PVA.

The coating composition for a plasticized PVC molded article comprising the urethane-modified PVA-based copolymer of the present invention can be used in a solid state or a solution state. Further, various additives are blended as required. Additives include coloring pigments, extenders, ultraviolet absorbers, ultraviolet stabilizers, colloidal silica, dispersants, fungicides, matting agents, and the like. The coating composition for a plasticized PVC molded article of the present invention comprises the urethane-modified P
It is preferable to use the VA copolymer dissolved in a general-purpose solvent such as toluene, xylene, and methyl ethyl ketone at a concentration of about 5 to 50% by weight, and to use the solution to obtain a solid content of 0.01 to 1.0 g. / M ² , preferably 0.05 to
Various plasticized PVC molded articles can be coated in an amount of 0.5 g / m ² .

In forming a coating with the coating composition for plasticized PVC molded articles, a hydroxyl group is intentionally left in the PVA copolymer, and the hydroxyl group is used to crosslink with various crosslinking agents, so that the heat resistance is improved. Properties, mechanical strength, water resistance,
A film excellent in solvent resistance and the like can be obtained. As the crosslinking agent, any polyfunctional compound that reacts with a hydroxyl group can be used. Specifically, for example, phenol,
Polyfunctional compounds such as melamine, epoxy and polyisocyanate compounds are suitable.

As a method for coating a plasticized PVC molded article with the urethane-modified PVA-based copolymer of the present invention, a urethane-modified PVA-based copolymer is dissolved in various solvents, and a gravure coater, knife coater, reverse coater, dipping,
It can be performed by a coating method such as brush coating, air spray, and airless spray. Alternatively, the coating composition for a plasticized PVC molded article of the present invention may be directly melt-molded into a film or a sheet, and then laminated on the plasticized PVC molded article. Lamination may be performed directly by thermal lamination, or may be performed via various adhesives.

The plasticized PVC molded article coated with the coating composition for a plasticized PVC molded article of the present invention is very useful as wallpaper, sheet, desk mat, leather, film, hose, tube and the like.

[0029]

EXAMPLES Next, more detailed explanation of the present invention by way of actual施例and comparative examples. In addition, in the texts and tables, "parts" or "%" is based on weight unless otherwise specified. As the described in Examples 1-3 Table 1, a degree of saponification of 98.5 mol% of PVA
(Polymerization degree 550), ε-caprolactone and a catalytic amount of tetrabutyl titanate are charged into a reaction vessel and heated at a rate of 1 ° C./2 to 3 minutes with stirring under a nitrogen stream. At 150 to 160 ° C., the reaction mixture which had been a heterogeneous system until then becomes gradually uniform, and at 180 to 200 ° C., it becomes a completely homogeneous system. The reaction is continued at 200 to 220 ° C. for 6 hours to obtain a PVA-based copolymer to which the aliphatic polyester used in the present invention is grafted.

[0030]

[Table 1]

Test Methods Tests of each physical property described in Table 1 were conducted by the following methods. * 1) Molecular weight: N of the copolymers obtained in Examples 1 to 3,
GPC measurement in N-dimethylformamide solution (5%). * 2) Hardness: The copolymer obtained in Examples 1 to 3 160
Press molding at a temperature of ℃ C.
It measured with the A type hardness meter based on -6301. * 3) 100% modulus (MPa), tensile strength (MP
a), elongation (%): The same press-formed sheet as used in the above hardness measurement was punched out with a JIS K-7311 No. 3 dumbbell, and the physical properties were measured. * 4) Vicat softening point: JIS K-
7206.

[0032] The copolymer 30 parts Example 4 Example 1 was dispersed in 60 parts of xylene, the reaction is carried out by adding stearyl isocyanate 166 parts at reflux temperature. The reaction mixture becomes homogeneous as the reaction proceeds. After the reaction mixture was completely homogeneous, the reaction was continued for another hour, and after cooling, the reaction product was poured into three times the amount of methanol to obtain a white precipitate. The white precipitate was washed, dried, and pulverized to obtain a urethane-modified PVA copolymer of the present invention. This copolymer was dissolved in xylene to a solid concentration of 10% to obtain a coating composition of the present invention.

[0033] Copolymer 30 parts of Example 5 Example 2, using 60 parts of xylene and docosanyl isocyanate 185 parts, others to obtain a urethane-modified PVA copolymer of the present invention in the same manner as in Example 4 . This copolymer was dissolved in xylene to a solid concentration of 10% to obtain a coating composition of the present invention.

[0034] Copolymer 40 parts of Example 6 Example 3, using 70 parts of xylene and hexa Conil isocyanate 200 parts, other Example 4
In the same manner as in the above, a urethane-modified PVA copolymer of the present invention was obtained. This copolymer was dissolved in xylene to a solid concentration of 10% to obtain a coating composition of the present invention.

The coating composition of the present invention obtained in Examples 4 to 6 was applied to a soft vinyl chloride sheet (3 mm thick) with a bar coater so that the film thickness after drying was 10 to 20 μm on both surfaces. This was dried at 80 ° C. for 30 seconds, and the following test was performed.

1. Test of plasticizer bleed-out amount A soft vinyl chloride sheet was cut into 50 mm x 50 mm, sandwiched between polyethylene sheets, and further sandwiched between glass plates. In this state, a load of 5 kg was applied, and the sheet was placed in a thermostat kept at 70 ° C.
Leave for 4 hours. Next, the polyethylene sheet is taken out from the thermostat, the polyethylene sheet is peeled off, and the amount of increase or decrease of the polyethylene sheet is measured. The smaller the value of the increase in the polyethylene sheet, the smaller the amount of bleed-out of the plasticizer from the soft vinyl chloride sheet.

2. Stain resistance A soft vinyl chloride sheet is cut into 50 mm x 50 mm, adhered to copy paper exposed in advance, sandwiched between glass plates,
In this state, a load of 3 kg is applied, and the resultant is left in a thermostat kept at 50 ° C. for 24 hours and 72 hours, respectively. Next, the sheet is taken out of the thermostat, each sheet is peeled off from the copy paper, and the degree of contamination of each sheet is observed.・ ・ ・: No contamination. Δ: Partial contamination. ×: Overall contamination.

3. Adhesiveness The coating film was cut into 100 squares of 1 mm square with a knife and subjected to a peeling test with cellophane tape. 4. Flexibility A flexible vinyl chloride sheet was bent 20 times at room temperature, and the state of the coating film was observed.・ ・ ・: No change. Δ: whitening. ×: Cracked.

5. Water resistance The soft vinyl chloride sheet was immersed in water at room temperature for one day, taken out, and dried at room temperature. The state of the coating film immediately after removal and after drying was observed.・ ・ ・: Although slightly cloudy immediately after removal, no swelling or the like was observed, and after drying, it was the same as before immersion. Δ: Cloudiness or swelling was observed immediately after the removal, but after drying, it was not different from the state before immersion. C: Cloudiness and swelling were remarkable immediately after taking out, and did not return to the state before immersion even after drying. 6. Water repellency The contact angle of the coated surface of the soft vinyl chloride sheet with a water drop was measured.

Examples 7 to 9 As Examples 7 to 9 , 100 parts of each of the coating compositions of Examples 4 to 6 were added to 0.5 part of a curing agent (manufactured by Nippon Polyurethane Co., Ltd.).
The solution to which coronate HX) was added was applied to a soft vinyl chloride sheet in the same manner as in Examples 4 to 6, and the coating was performed at 80 ° C. for 30 minutes.
The same test as in Examples 4 to 6 was performed on the sample dried for 2 seconds and left at room temperature for 1 day.

Comparative Example 1 The same tests as in Examples 4 to 6 were carried out without coating the coating composition on a soft vinyl chloride sheet. Comparative Example 2 An aqueous solution (solid content: 15%) of PVA (degree of polymerization: 550) having a saponification degree of 98.5% was applied to a soft vinyl chloride sheet, and the same tests as in Examples 4 to 6 were performed.

Comparative Example 3 A mixture of an acrylic resin (manufactured by Mitsubishi Rayon, acrylic polyol LR-620) and a curing agent (manufactured by Nippon Polyurethane, Coronate HX) was applied to a soft vinyl chloride sheet and the same as in Examples 4 to 6 Each test was performed. Comparative Example 4 A soft vinyl chloride sheet was coated with a fluorine resin for vinyl chloride (Fluorotop, manufactured by Asahi Glass Co., Ltd.) and a curing agent (Nippon Polyurethane,
The mixture containing Coronate HX) was applied, and Examples 4 to
Each test similar to 6 was performed. Table 2 shows the results of the above tests.
Show.

[0043]

[Table 2]

[0044]

As described above, the urethane-modified P of the present invention
When a coating composition comprising a VA copolymer is coated on a plasticized PVC molded article, the coating composition prevents bleed-out of a plasticizer contained in the plasticized PVC molded article, thereby preventing contamination of the molded article surface and water repellency. Gives a film having excellent release properties.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Katsumi Kuriyama Inventor Dainichi Seika Kogyo Co., Ltd. 1-7-6 Bakurocho, Nihonbashi, Chuo-ku, Tokyo (56) Reference JP-A 5-295332 (JP, A) JP-A-5-39342 (JP, A) JP-A-9-302074 (JP, A) JP-A-9-67414 (JP, A) JP-A-9-59326 (JP, A) JP-A-9-67430 (JP JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 16 / 06,116 / 06,216 / 06 C08G 18/06-18/26 C08G 63/08 C09D 129/04

Claims (6)

(57) [Claims] 1. An aliphatic polyester having a terminal OH group obtained by reacting 90 to 40 parts by weight of polyvinyl alcohol with 10 to 60 parts by weight of a lactone compound capable of forming an aliphatic polyester by ring-opening polymerization, to, polyvinyl polyvinyl alcohol copolymer obtained by grafting to form the OH group and an ester group
Non-grafted OH groups in alcohol and the above
It is obtained by reacting a terminal OH group of an aliphatic polyester with a monoisocyanate compound having an aliphatic group having 12 or more carbon atoms, and having a number average molecular weight of 10,000 to 500,0.
00. A modified polyvinyl alcohol-based copolymer characterized by being 00. 2. The method according to claim 1, wherein the polyvinyl alcohol is vinyl acetate
The modified polyvinyl alcohol copolymer according to claim 1, wherein the degree of saponification is 60 mol% or more. 3. The modified polyvinyl alcohol copolymer according to claim 1, wherein the aliphatic polyester comprises polycaprolactone or polyvalerolactone. 4. The amount of the monoisocyanate compound having an aliphatic group having 12 or more carbon atoms is 50 to 500 parts by weight per 100 parts by weight of the polyvinyl alcohol-based copolymer to which the aliphatic polyester is grafted . The modified polyvinyl alcohol-based copolymer according to claim 1, which is a ratio . 5. Polyvinyl alcohol 90 to 40 parts by weight
Which can form an aliphatic polyester by ring-opening polymerization
React with 10 to 60 parts by weight of
Of alcohol with aliphatic polyester grafted
OH in the obtained graft copolymer is formed.
Monoisocyanate having a group and an aliphatic group having 12 or more carbon atoms
Anate compound, 100 parts by weight of the graft copolymer
50-500 weight of the monoisocyanate compound per weight
Characterized in that it is reacted in the proportion of parts
A method for producing an alcohol-based copolymer. 6. The modified polyvinyl alcohol-based copolymer according to any one of claims 1 to 4, or the modified polyvinyl alcohol-based copolymer according to claim 5.
Modified polyvinyl alcohol copolymer obtained by the method described above
A coating composition for a plasticized vinyl chloride resin molded article, comprising a body.