JPS58206607A - Modified polyvinyl alcohol polymer and its production - Google Patents

Abstract

PURPOSE:The saponification of a copolymer of vinyl acetate and a specific hydroxyalkyl vinyl ether gives the titled polymer that has three different kinds of specific structural units and a specific viscosity and shows high water resistance, solubility and viscosity stability at low temperatures. CONSTITUTION:A polymerization catalyst such as benzoyl peroxide is added to vinyl acetate and hydroxyalkyl vinyl ether of formula I (R is 1-18C alkylene) to effect solution polymerization. The resultant copolymer is combined with a solvent such as methanol and a saponification catalyst such as potassium hydroxide to effect saponification, preferably at 20-50 deg.C for 0.1-5hr to produce the objective polymer that consists of structural units of formula II, III, IV [mol% of formula II is 0.2-10; formula IV/III+formula IV (mol%=0.9-0.995; R is 1-18 alkylene] and has a viscosity of more than 3 cps as 4wt% aqueous solution at 20 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified polyvinyl alcohol-based polymer and a method for producing the same.The present invention relates to a modified polyvinyl alcohol-based polymer and a method for producing the same. The present invention also relates to an easily soluble modified polyvinyl alcohol polymer and a method for producing the same.

Conventionally, polyvinyl alcohol (hereinafter abbreviated as PVA) has been used.

) is used as an aqueous solution in fields such as adhesives,
It has also been used as a protective colloid in emulsions. Both aqueous solutions and emulsions are often left to cool for a while, and in such cases, the viscosity of the aqueous solution or emulsion increases over time, and in extreme cases There was a problem that sometimes the amount of water discharged from the container was not uJ' i+L. Roughly.

PVA with a saponification rate of 90 mol/l or more has disadvantages in that the temperature required for dissolution is low and the dissolution rate is low.

A bath 1. What is the increase in the viscosity of an emulsion (vinyl acetate emulsion on the lips) over time when it is left in a cold place?

The higher the degree of oxidation and the higher the concentration of PVA used. Therefore, in order to produce a shoulder agent for PVA yarn that will be placed in a cold place, PVALI with a low degree of saponification is used, and PVA (7) 811L is used to minimize the change in viscosity over time. However, in such a case, the water resistance of the PVA film will be lowered due to the lower phosphor absorption, so it is necessary to request water resistance after completion of construction. However, it is still necessary to consider the water resistance after completion of the construction.Naito et al.

(1955) reported that even with PVk having the same degree of saponification, the low-temperature viscosity stability' differs depending on the intramolecular distribution of residual acetic acid groups. Therefore, the intramolecular distribution of residual acetic acid groups becomes more random than that of normal alkali-saponified PVA, such as vinegar-based PVA and acid-saponified PVAr, resulting in improved low-temperature viscosity stability. However, although acid saponification is an industrial LIJ' rudder, the reaction rate is slower than alkali saponification, and performing -Banko acetylation is disadvantageous for industrial VC because the operation is complicated.

Also, in Japanese Patent Application Laid-open No. 56-14544, C4 to C2
(1<D long-chain alkyl vinyl ether-modified PvA is listed as having good storage stability of an aqueous solution of this and raw starch, but hydroxyargyl vinyl ether as in the present invention There are no reports on needle-modified PVA.

The present inventors provide a PvA thread-heavy thread body that is water resistant and has improved disintegration properties and low-temperature viscosity stability, and provides an industrially advantageous method for producing the same. As a result of intensive research, we have arrived at 9 books @ Ming.

The origins of the polymers e and 8 in these six examples, (B) and ((?
) It is a graded PVA type W combination consisting of ↑14 building units, and the viscosity of 4 x 1 x 1 water i = 11 IV at 20C is at least 3 centiboise.

f C112-CA13 (A) ■ O-R-OH f C112-Chi U
(B) 0- CO-Cl13 + ct■2- CI 'j (C
)OH (Tatashi, the molar value of the +s sho unit prison is 0.2 to 1o, and the molar value of the structural unit (B) and the structural unit (mol of Q -〇〇 dth C to Sakaki m * b7. (The molar ratio of C'l is 0.9 to 0995, and 1ζ represents an alkylene group having a carbon number of 1 to 18.) R2 in the structure γ(5), that is, the number of carbon atoms in the alkylene group is the LIT capacity for one history from 1 to 18.If the a゛k of the structural unit (4) in the polymer is constant, and the molar concentration of the structural unit (B) and the fermentation threat b'tl (C) When the molar ratio is constant, as the number of carbon atoms in the alkylene group increases, the viscosity of the aqueous solution becomes lower and the water solubility becomes lower. In the case of PVA, the viscosity does not become very high, the rate of decrease in water solubility is small, and the compatibility with unmodified PVA does not decrease. In order to maintain the relationship between It is most desirable that the number of carbon atoms is 4. If the content of the structural unit (4) is less than 0.2 mol, the effect of low temperature stability and easy solubility will not be significant, while if it exceeds 10 mol, the viscosity will increase.

Although the easy solubility is improved, the water resistance of the film is significantly reduced. Therefore, in order to improve the low-temperature viscosity stability of the aqueous solution without causing a significant decrease in the water resistance of the film, and to bring about the effect of easy solubility, its content should be 0.2 to 10 mol, preferably 0.5 to 5 mol. . The sum of the molar forces of the structural unit ω) and the molar forces of the structural unit ■ is '60 of the molar force of the Sakaki position (C), which is 09 to 0.995. Nanoha is over 0.95-Hi-Gr'Ce
Rir. And two polymers of the present invention.

The viscosity of the water bath liquid at 20C is at least 3 centimeters. .

The blood combination of vinyl acetate and the general formula % formula % (T i'c, R represents an alkylene group of 1 to 18). "l Lukyl Vinyl Edel (for LAVE and approximately 0 self'noru. N and ≠±yob-Shashu #Kiki co-rumor "Shi, prepared by saponifying the Communist East union that was used by the audience and others) can do.

31, the method C can be either a bath solution polymerization method or a turbid polymerization method, but solution polymerization is preferable from an engineering point of view.

For solvent binding that can be used for bathing liquids, methanol, alcohols such as ethyl alcohol, ethyl acetate, and varnishes such as methyl acetate and ethyl acetate.
Examples include aromatic hydrocarbons such as /l/m + be/zene and toluene, but methanol is particularly desirable from an industrial standpoint. HAVE can be used from hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxyglobin vinyl ether, hydroxybutyl vinyl ether to hydroxystearyl vinyl ether with an alkylene/group having 18 carbon atoms. But that's fine.

Further, the -C may be added in portions or continuously during the blood flow. The polymerization machine may be of either a batch type or a continuous type, and one that is used for polymerization of vinyl acetate can be used. As the catalyst, for example, a peracid spinning catalyst such as per-#R1hibenzoyl, or an azo catalyst such as rzobisisobutyronitrile can be used. I of unreacted monoplants after polymerization! The removal is done by a conventional method such as evaporating the monomer in a bath medium.
A known method can be used to prepare vinyl acetate (g).

In this case, *the hardware is dissolved in the saponification bath medium, and the evaporated m medium and unreacted single substance are recovered and circulated P) 1 History J+J
- No matter what, Ushio Xc will do it.

Examples of solvents used in the saponification reaction include alcohols such as methanol, ethanol, and isopropanol;
Examples include a mixed solvent of esters such as methyl acetate and ethyl acetate and alcohol, a mixed solvent of water and alcohol, and methanol is preferably used. A suitable concentration of the polymer during saponification is usually selected from the range of 20 to 70 tS.

Examples of saponification catalysts include potassium hydroxide.

Alkaline catalysts such as alkali metal hydroxides such as sodium hydroxide, sodium methylate, sodium ethylate, and alcosheets, or sulfuric acid.

*An acid catalyst such as es is used. The amount of catalyst to be used is usually 0.1 to 5.0 moles relative to vinyl acetate. A suitable saponification temperature is usually selected from a range of 20 to 50°C, and a suitable reaction time is 0.1 to 5 hours. Conveyor method (continuous) for saponification reaction wax.

Either one kneader type (batch type) can be used.

In addition, solid-liquid separation, drying, and pulverization after saponification are performed using conventional PVA.
equipment can be used, and it can be produced industrially advantageously.

Among the polymers of the present invention, HAVE modification degree [structural unit (4
) represents the morchi. ] is 0.5 to 5 mol, ken mole [structural unit (represents the number obtained by multiplying the ratio of mol of O by 100) to the sum of mol of structural unit (6) and mol of structural unit C] is 98 to The dissolution time required to make a 99.5% modified PVA-based polymer into a 10% by weight aqueous solution was within 40 minutes at 50°C.

On the other hand, in the case of unmodified PVA with the same degree of saponification, it took more than 40 minutes to dissolve even at 90C. Furthermore, the water resistance of the film was almost the same as that of unmodified PVA. Furthermore, when a 10 weight aqueous solution of the above modified PVA-based polymer was maintained at 0°C, the viscosity after 1 hour (A) and the viscosity after 10 hours (
The ratio (b)/(a) of (b) was less than 5, but the unmodified P
The ratio in the case of VA was 10 or more. In addition, the degree of HAVE denaturation is 0.5 to 5 mol★, and the degree of denaturation is 95.5 to 95.5.
The dissolution time required to prepare a 97.5% modified PVA-based polymer into an aqueous solution containing 10 quintillion amounts was within 40 minutes at 40°C. On the other hand, in the case of unmodified PVA having the same degree of saponification, it took more than 40 minutes to dissolve even at 80'C. Furthermore, the water resistance of the film was almost the same as that of unmodified PVA. Furthermore, l of the above modified PvA polymer
When a water bath solution with a heavy lid is maintained at oC, the ratio of the viscosity (c) after 1 hour to the viscosity after 24 hours (c)/(c) is 3.
However, the ratio in the case of unmodified PVA was 5 or more.

As described above, the modified PVA polymer of the present invention is easily soluble and has an excellent energy saving effect upon dissolution. In addition, it exhibits a property in which the viscosity does not increase over time in a cold place, that is, good low-temperature viscosity stability, and also shows a desirable property in that the water resistance of the coated film is not lost.

In addition, HAVE denatured products have alkali resistance and crushability 11 degrees, and because of the hydroxyl group at the end of the alkyl group of HAVE, it has the ability to be easily injected intravenously with Yuzu's unmodified PVA. On top of having.

It has various features such as superior shelf temperature properties compared to starch.

From the point E-1, the polymer of the present invention can be used as an aqueous solution for paper, wood, commercial adhesives, cement, mortar, etc. 11! ! Static binders such as inorganic materials, emulsion stabilizers and suspending agents such as vinyl acetate.

It is particularly suitable for applications such as films, molded products, and fiber sizing agents.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In addition, in the following examples, the molarity of the structural unit (4) in the polymer, that is, the degree of HA VE modification, was determined by the following method.

Polymer 2II was collected and dissolved in 200 N of aqueous acetone with a water-containing cap of 100% IA. After dissolving, add 1N sodium hydroxide bath solution 6o- to this bath solution and heat at 55°C.
Saponification reaction is carried out for 60 minutes. Due to the saponification reaction, the acetate group in the vinyl acetate unit becomes a hydroxyl group, so the saponification reaction ec
*Hydrogenation) The number of moles of IJium was added to 1 of the above reaction solution.
゛Determine from K by back titration with specified sulfuric acid water bath solution, and from the result, ? The density and HAVE modification degree of vinyl acetate units in the polymer were determined using the X formula.

Weight of vinyl acetate unit t %OO = 43a x 100
[However, a represents the number of moles of sodium hydroxide required for the saponification reaction, 2M, and the molecular weight of the structural unit (4). ] Also, "part" in the 9 examples means "1 part by weight".

Example 1 6,650 parts of vinyl acetate, 350 parts of hydroxybutylhinyl ether, and 300 parts of methanol were charged into a polymerization reactor, and the temperature was raised while stirring the system under nitrogen.

When the temperature reached 60°C, a solution of 4.2 parts of azobisisobutyronitrile dissolved in 200 parts of methanol was added,
Started mixing. When the solid content concentration reached 6 parts, the mixture was cooled to complete the polymerization.

Methanol vapor was blown into the obtained polymer m solution to remove unreacted vinyl acetate, thereby obtaining a methanol solution of polymer 1. Next, methanol was added to this bath solution to adjust the concentration of the polymer to 35%, and then 60% of the bath solution was added.
The electrolyte solution was gelled in about 8 minutes after mixing with a solution of 12 parts of IJium dissolved in aqueous methanol without stirring. This gel-like material was crushed after 60 minutes and thoroughly washed with methanol.

It was dried under a nitrogen stream at 100C to obtain 1100 parts of a modified PVA polymer in the form of white granules. This polymer is HA
VE modification degree is 3.4 molti, saponification degree is 98.5
The viscosity of a water solution with a 4-coulometric S concentration at 20° C. was measured with a rotational viscometer and was 15 CPS.

100 g of the obtained polymer was mixed with 900 g of ion-exchanged water at 50°C.
The mixture was added to a portion under stirring at 15 rpm.

The time required for the polymer to completely dissolve was 35 minutes. In addition, when measuring the low-temperature viscosity stability of an aqueous solution using 10 layers of the relevant aqueous solution at 0°C, the viscosity after 1 hour and 10 hours after being placed at 0°C was 100%.
0 and 3500 CPS. Moreover, a width of 10 m, l! was prepared from an aqueous solution of this polymer. ii After heat treatment of a film with a length of 0.1 cm at 120°C for 10 minutes.

When the film was immersed in water at 30°C and a load of 31 was applied, the time required for the film to break was measured, and it was 500 seconds.

Comparative Example 1 A polymer was obtained by polymerization and saponification in the same manner as in Example 1, except that 7000 parts of vinyl acetate was used instead of hydroxybutyl vinyl ether. The degree of saponification of the obtained polymer was 98.5 mol.
The viscosity at 200 of an aqueous solution with a concentration of 4% by weight is 15CP
It was S.

When this polymer was subjected to a dissolution test in the same manner as in Example 1, the dissolution rate was about 50 ts in 30 minutes,
Even after 90 minutes, 65SL did not dissolve.

Also, the viscosity of the 10-tqIb aqueous solution at 0°C is:

After being placed at 0° C., the PS was 12,000 1 hour later, and gelatinized after 3 hours. Further, when the time required for the film to break in water was measured in the same manner as in Example 1, it was 700 seconds. Further, in the case of a polymer having a saponification degree of 96.5 molt obtained during the saponification reaction to obtain the polymer, the time until cutting was 100 seconds.

Example 2 6000 parts of the polymer obtained in Example 1 in a methanol bath d with a concentration of 35% was maintained at 40°C and instantaneously mixed with a solution of 9910 parts of sodium hydroxide dissolved in water-containing methanol while stirring. Mixed. The polymer solution gelled approximately 10 minutes after mixing. This gel-like material was crushed after 60 minutes, thoroughly washed with methanol, and then dried under a nitrogen stream at 100° C. to obtain 1130 parts of a white granular polymer. This polymer has a saponification degree of 965 mol-f6, a HAVE modification degree of 3.4 mol-1, and a viscosity of an aqueous solution with a 4-mlte concentration at 20°C of 1.
It was 4CPS.

100 parts of the obtained bundle was mixed with 900 parts of ion-exchanged water at 40°C.
When the mixture was stirred at 150 rpm, it took 30 minutes for the mixture to completely dissolve.

In addition, when the low-temperature viscosity stability of the aqueous solution was measured using the same method as in Example 1, the viscosity after 1 hour and 24 hours after being placed on top of the OC was 900 gL and 2000CP.
It was S.

Comparative Example 2 A saponified polymer having a saponification of 1196.5 mol was obtained in the same manner as in Example 2 except that 7000 parts of vinyl acetate was used instead of hydroxybutyl vinyl ether. An aqueous solution of this polymer with a concentration of 4 to 20
The viscosity at C was 14 CPS.

When a dissolution test was conducted on this electric combination in the same manner as in Example 2, the dissolution rate was about 60 cm in 30 minutes, and 9
Even at 0 minutes, only 70 parts were dissolved.

In addition, when the low-temperature viscosity stability of the 10-fold aqueous solution was measured using the same method as in Example 2, it was found that the 11-fold aqueous solution was
．． After 1 hour and 24 hours, the viscosity was 1000 and 5000 CPS, respectively.

7,722 parts of vinyl acetate, 78 parts of hydroxybutyl vinyl ether, and 2,000 M of methanol were put into a 113 fL tank, and the temperature was raised under Muroki while stirring the system.

When the temperature reached 60℃, azobisisobutyronitrile 2
A solution prepared by dissolving 5 parts in 200 m of methanol was added to start polymerization. The polymerization reaction was terminated when the solid content I# degree reached 55 degrees. This polymer was subjected to a saponification reaction, pulverization, washing, and drying in the same manner as in Example 1 to remove unreacted vinyl acetate. The physical properties of the obtained modified PVA-based electrolyte are shown in Table 1.

Example 4 A polymer was obtained in the same manner as in Example 3 except that hydroxyethyl vinyl ether was used instead of hydroxybutyl vinyl ether. The physical properties of the obtained modified PVA polymer are shown in Table 11/C.

Example 5 This composite was obtained in the same manner as in Example 3 except that hydroxyoctyl vinyl ether was used instead of hydroxybutyl vinyl ether. The physical properties of the modified PVA polymer were shown to person 1.

Comparative Example 3 A polymer was obtained in the same manner as in Example 3 except that 7,800 parts of vinyl acetate was used instead of hydroxybutyl vinyl ether. Table 1 shows the physical properties of the excellent polymers.

Table 1 note)

Claims (1)

[Scope of Claims] (1) A modified polyvinyl alcohol consisting of the following constituents, (B) and the structural unit shown in the figure, and having a viscosity of at least 3 centivoise in a 4-coulometric water bath at 20C.
Thread polymer. + (lL2- CH”j (A)0-
R-OH e CH2-CH
(B) "0- CO-CH3 (CH2-CH) (C) OH (However, the molar value of the structural unit (J3) is 0.2~1O (゛), and the molar value of the structural unit (J3) and the structural unit ( The structural unit for the sum of the moles of Q (the angle of the moles of Q is 0.9
~0.995, and R represents an alkylene group having 1-18 carbon atoms. ) +21 it is an alkylene group having 4 carbon atoms, the lk aggregate (,1) of claim 1, wherein it is an alkylene group having 4 carbon atoms. , , R represents the layer system u1-181) Archilev foundation. The hydroxyalkyl vinyl ether is reduced by the following and 4
4% tlj and the resulting co-mid keku/comparison is the following cause, (B) warping (
A method for producing a modified polyvinyl alcohol polymer which is composed of the structural unit represented by Q7 and whose viscosity of a 4!L4M% water bath solution at 20C (ζ) is at least 3 senna. 0
11 (Cfi2-Cl(8)0-CO
-C113 (C+t) - C)f
(C)H (7'c, the molar value of the structural unit prisoner is 0.2~10-(
'Yes, the ratio of the molar range of the structural unit (Q) to the total molar range of the structural unit (Q) is 0.
9 to 0.995 TEL represents the alkylene group of R&i carbon Xal-18. ) (4) The manufacturing method according to claim 3, wherein R is an alkylene group having 4 carbon atoms.