DE1094457B - Process for the production of modified polyvinyl alcohols - Google Patents

Description

GERMAN

The patent 1 081 229 relates to a process for the production of water-soluble modified polyvinyl alcohols, characterized in that a graft polymer of one or more vinyl esters and optionally other compounds capable of copolymerization with vinyl esters on polyalkylene glycols of an acidic or subjected to alkaline, complete or partial saponification or transesterification.

Modified polyvinyl alcohols in the sense of the main patent are water-soluble polymeric compounds understood that at least 50 percent by weight from the units

-CH ₂ -CH- OH

exist.

The products obtained in this way, in which the graft structure is used as the starting material Graft polymer is completely retained, have a whole range of new, technically very valuable properties.

It has now been found that high-quality, water-soluble saponification or transesterification products are obtained, if less than 50 percent by weight of the modified polyvinyl alcohols from the units

-CH ₂ -CH- OH

exist.

These products are preferably used in the partial saponification or transesterification of such graft polymers obtained, which were prepared by polymerization of vinyl esters in the presence of polyethylene glycols, but also of those that are in the presence of oxethylated polypropylene glycols and higher homologues of the Polypropylene glycol.

The saponification or transesterification is carried out according to the known processes in the presence of solvents or solvent mixtures, e.g. B. methanol or methanol-water, batchwise or continuously, optionally in an inert atmosphere, e.g. B. in the present of nitrogen.

In the alkaline saponification or transesterification z. B. sodium or potassium hydroxide dissolved in methanol as a catalyst. It is generally sufficient to add an alkali in catalytic amounts. You can do the saponification at room temperature or at higher temperatures.

The determination of a desired degree of saponification can usually once by varying the catalytic Alkali quantities take place, on the other hand, by interrupting the saponification reaction at the desired stage by adding small amounts of acids to neutralize the alkali catalyst.

However, it is also possible to obtain correspondingly partially saponified products by using the different production methods
modified polyvinyl alcohols

Addendum to patent 1,081,229

Applicant:

Farbwerke Hoechst Aktiengesellschaft

formerly Master Lucius & Brüning,

Frankfurt / M., Brüningstr. 45

Dr. Karl-Heinz Kahrs, Frankfurt / M.,
and Dr. J. Wolfgang Zimmermann,

Frankfurt / M. -Unterliederbach,
have been named as inventors

lent saponification rate of different copolymerized Exploits vinyl ester. One goes to it

z. B. from a graft copolymer vinyl formate Vinyl stearate made in the presence of polyalkylene glycol.

Furthermore, the known methods of saponification or transesterification in an acidic medium, eg. Am Presence of sulfuric acid, apply to the production of modified polyvinyl alcohols claimed here, optionally in combination with a simultaneous or subsequent partial acetalization of the saponification product.

The present invention deals with the preparation of such modified polyvinyl alcohols based on its graft structure units of polyalkylene glycol and also hydrophobic organic radicals, e.g. B. Polyvinylacetatreste, incorporated, both components in such weight ratios that the The proportion of polyvinyl alcohol units in the macromolecule formed by saponification is less than 50 percent by weight amounts to.

The lower limit of this content of polyvinyl alcohol units is characterized in that the modified polyvinyl alcohols obtained are at least in cold water, e.g. B. water of 10 ⁰ C should be soluble.

This condition is largely dependent on the type and amount of that contained in the starting graft polymer Polyalkylene glycol and the content of hydrophobic residues in the saponification product.

The presence of chemically bound polyalkylene glycol in the starting graft polymer allows im produced therefrom by saponification or transesterification

009 677/467

3 4

modified polyvinyl alcohol leaving or allowing the feed of the polymerization mixture 1 to

Incorporation of unusually large amounts of hydro- increased for 2 hours to 90 ⁰ C, with the reflux

phobic organic residues without the water solubility ceasing. Subsequently, at this temperature is not

is lost. converted monomer by applying a pulsating

Surprisingly, the water solubility of the 5 vacuum is removed.

Products according to the invention due to the hydrophobic one receives 198 parts by weight of a clear, colorless

Residues are not impaired, but are actually considerably reduced.

promotes; However, if the weight percentage of hydro- Cellulosechemie, Vol. 13, p. 58 [1932]) 45 (1% in ethyl

phobic organic residues in the macromolecule of certain acetate measured).

Exceeds values, the formation of io _,. ,, _, ... _.

Turbidity phenomena when the aqueous partial saponification or transesterification is heated

Solutions. 350 parts by weight of the graft polymer obtained above

The starting materials used in the process according to the invention are dissolved in 641 parts by weight of methanol and

material used graft polymers are according to 9 parts by weight of water.

Method of the German patent application F 25494 IVb / 15 37 Ge

39c (now German Auslegeschrift 1 077 430) produced parts by weight of a 5 weight percent methanolic

given by polymerization in a homogeneous phase of vinyl sodium hydroxide solution.

esters, such as vinyl acetate, propionate, butyrate, stearate, the mixture is at 30 ⁰ C for about 1 hour until

stirred alone or in mixtures with one another with or without the start of thickening. After that the stirrer will

mischpolymerisationsfähige more compounds forward ao stopped and the gel formed overall for 4 hours at 30 ⁰ C.

preferably of vinyl acetate, hold in the presence of poly.

Ethylene glycols and its derivatives, if necessary, then pure water vapor is added to the gel with the use of solvents. As polyblown, the stirrer started up again and ethylene glycols can be used, preferably steam distilled, until all organic solvent-water-soluble types with a molecular weight of 10,000 to 25 have been removed from the reaction vessel and several million, still water-soluble Derivatives aqueous solution of the saponification product of about these polyethylene glycols, for. B. has arisen on both sides or simply 25 percent by weight.
etherified or esterified at the terminal hydroxyl groups "," ,,.,
Polyethylene glycols, including particularly oxyethylated composition of the saponification product:
Polypropylene glycols and corresponding homologs. Also 30 polyvinyl acetate units

Derivatives in which one or both hydroxyl groups ™ macromolecule 25 percent by weight

are substituted by mono- or polyfunctional polyvinyl alcohol units

Amines or amides, also water-soluble conversion in the macromolecule 43 percent by weight

Products with mono- or polyisocyanates come in polyethylene glycol units

F _ra g _{e- 35} in the macromolecule 32 percent by weight

The amounts of polyethylene glycol or polyethylene bound in the starting graft polymer. Example 2
Glycol derivative remain completely in the saponification product According to that described in Example 1 and not retained here. claimed mode of operation is a graft polymer

The new modified polyvinyl alcohols have tech- 40 made from

nisch very valuable properties: _rn “. _,,, . , ΛΤ. ,

They are excellently suited as a surface and border JO 9 ^ TT ■ f * ^ w *? _D,,

Surface-active substances, e.g. as a protective cover for the 49 parts by weight of oxy-hydrogenated polypropylene oxide

Dispersion polymerization and as a starting material for the following key figures:

Manufacture of foams such as sponges. 45 η IMhI 23

The new modified _ . ', - ^ _{,,, 7no /}

Polyvinyl alcohol as a material for the manufacture of soft, uxatnyigenalt about / u / ₀

slightly water soluble, clear transparent films comparable _{Ο χ} d in 2000 polypropylene used

that turn out of solution as well as thermo- _Λ „. J, '., _ ..,,

can be processed plastically. ₅ ο 1 part by weight of dibenzoyl peroxide

Further areas of application arise on the This graft polymer is cleaned by

A textile auxiliary sector as sizing and finishing agents, a 10 ° / ₀ aqueous solution thereof to about 7O ⁰ C heated

also in cosmetics. separates the product which is deposited, with hot

Example 1 Water washes and at room temperature in vacuo

TT _A 17 j ι_ · · 1. i_! .J. 55 dries.
Manufacture of what is not claimed here

Starting graft polymer saponification or transesterification

In a glass bottle with an attached reflux condenser 100 parts by weight of the above product are in

and dropping funnel, 5 to 10 parts by weight of 180 parts by weight of methanol are dissolved, 2.6 parts by weight

Solution of 60 water and then 12 parts by weight of 5 ° / ^ εη methanolic

., ""., .. ·, τ? - 1 ^ 1. Sodium hydroxide added. At 30 ° C the reaction

^ GewMAtsteden vinyl cortation mixture stirred for 5 hours. This creates after

40 weight points of polyethylene glycol from _{γ gtunde} ^ _vigkose ^ _{which, however, is not so highly viscous}

ac · T _{1+ +} ·, molecular weight 25,000 j _that ^ _{Rüh ab U} J _{must be} _ _{When Ab} _

_Cool 4 parts by weight of dibenzoyl peroxide _{65 & u {Zimmert} ^S _emp | _ratur ^ _{a gel is given i} J _n

by heating on the water bath at 8O ⁰ C anpoly- the water vapor is blown in, with exhaust

merized. distill the methanol and methyl acetate a clear

After the start of the polymerization, the remaining aqueous solution will be formed. The product is made from the

Solution added dropwise over the course of about 2 hours. Isolated from the aqueous solution by evaporation and im

The bath temperature after termination is complete polymerization 70 vacuum at 40 ⁰ C to constant weight.

ι υ υ t ** ό ι

5 6

Content of the product of vinyl alcohol groups in the closing 6 hours at a bath temperature of 95 ⁰ C

Macromolecule = 27.3 percent by weight. and under a nitrogen atmosphere of 1.5 atü

. polymerized.

.Example ό The approach is then carried out with methanol on a

The here not claimed production of the starting 5 solids _{content of 40 ° / 0} diluted,
graft polymer is done as follows: -

Saponification or transesterification are carried out in a kettle with stirrer and reflux condenser
to 300 parts by weight of polyethylene glycol of molecular weight about 25 000 in the case 9O ⁰ C water bath temperature up to a boiler and melted with a thermometer. 50 to 100 parts by weight of a stirrer are added to this melt, and 1000 parts by weight of the 40 weight percent acetate and 16 parts by weight of dibenzoyl peroxide prepared as described above for a solution of 1700 parts by weight of vinyl are added. methanolic graft polymer solution and after a short time the polymerization begins, and the ^{above solution at 20 o} C with stirring 13.4 parts by weight of a 5 weight remainder is added dropwise over the course of 1 hour with constant slow stirring under a percent solution of sodium hydroxide in methanol. 15 added. Viscosity starts after about 30 minutes

5 minutes after the end of the monomer feed to increase sharply, and the stirrer is switched off,

be 600 parts by weight of methanol in the reaction slowly The reaction is carried out for 4 hours at 20 ⁰ C,

tion mixture added dropwise. The saponification is then terminated

Ventilation of the reaction kettle closed and in the kettle by adding 3.5 parts by weight of glacial acetic acid dissolved in

a pressure of 0.5 to 1.5 atmospheres is generated with nitrogen. At 20 110 parts by weight of methanol.

this pressure and a water bath temperature of 80 until the mixture is then in vacuo at 8O ⁰ C

90 ^° C., the polymerization is dried slowly for 6 hours, the modified according to the invention

Stirring to the end. After cooling and de-polyvinyl alcohol is obtained as a powder. The analytical

ventilation, the resulting polymer solution with examination of the reaction product shows that it is

2000 parts by weight of methanol diluted. 25 is composed as follows:

This solution is determined according to a solids content of polyvinyl acetate units 27%

mung with methanol to exactly 40 percent by weight of solid polyvinyl alcohol units 48%

substance content adjusted. Polyethylene glycol units 25%

Partial saponification or transesterification

478 parts by weight of the above 40% strength polymer P

solution are in a stirred tank with reflux condenser, in the apparatus described in Example 4 and after

which can be switched to distillation, while stirring the method described in Example 4, a graft

at 20 ° C. mixed with 5.92 parts by weight of a 14.45% polymer solution prepared from

Solution of sodium hydroxide in methanol, after about 35 620 parts by weight of polyethylene glycol from the molecular

40 minutes begins the "thick phase", i. that is, it weighs 25,000

The resulting saponification product is insoluble in methanol ₁₃₈₀ parts by weight of vinyl acetate

and temporarily forms a tough gel. _{Of these 14} parts by weight of dibenzoyl peroxide

Time can be determined accurately to ± 7 ₂ minute. 138 parts by weight of methanol

23 minutes after the start of this "thick phase", 40
the now crumbly reaction product one

Solution of 1.5 parts by weight of acetic acid in 35 parts by weight saponification or transesterification

share methanol stirred. , ",.", .. The, as described above, produced graft polymer

After 15 minutes, the radiator is _satlö overall on DesüUation ktionsgefäß _{is in balance} with _Rea 862 switched and m a vacuum of 40 Torr at 50 C 45 ™ _chtst 4 _n ^S _{methane ol verdünil} t ^ d at 2O ⁰ C under Rüh-

™ _chtst 4 _{n methanol diluted} t ^ d at 2OC with stirring

Water bath temperature with stirring AND ALL Losungs- _ren ^ _{gi Gewichtsteüen a 15} o _{/ o me} thanolischen medium enttemt sodium hydroxide are added.

There are no 120 parts by weight of a colorless fine- _{The re} 4 _tio / _{is finished in} ! Hours. Afterward

powdery modified polyvinyl alcohol, whose macro- ^ _{dag Reakti mix a} steam distillation molecules following average composition 50 _{subject fil) at d} | _{r the} purchased methanol-methyl-

acetate mixture is distilled off and an aqueous

Vinyl acetate units leave a 27% solution of the modified polyvinyl alcohols.

Vinyl alcohol units 47 ° / ₀ The resulting modified polyvinyl alcohol has

Ethylene glycol units 26 ° / _0,. the following composition:

Polyvinyl alcohol units 44.0%

Example 4 polyvinyl acetate units 8.0%

The production of the starting polyethylene glycol units not claimed here 48.0%

Graft polymer is done as follows:

In a boiler that can be heated by a water bath, the 60 B "" 1 6

with a stirrer, reflux condenser, thermometer and "

Is equipped with a nitrogen connection, 150 weight graft polymer

parts of polyethylene glycol, the _{M SSD} to the terminal hydroxyl groups _{in the Ap} ^ p ^ d _{Aratur described} after ₄

a nut Dnsocyanat is implemented and the method _described, a molecular _of ^ ^^ ₄ ^J is has a Pfropfkulargewicht of about 50 000 under a nitrogen 65! _risat ^F _lös prepared from
substance atmosphere melted. This melt becomes ^{r J} 00

then at 90 ⁰ C bath temperature and with stirring an 820 parts by weight of polyethylene oxide of the molecular

Solution of 850 parts by weight of vinyl acetate, 8 parts by weight 4000

parts of dibenzoyl peroxide and 250 parts by weight of methanol 1180 parts by weight of vinyl acetate

slowly admitted. The reaction mixture is an- 70 12 parts by weight of dibenzoyl peroxide

Claims (1)

7 8 Saponification or transesterification After 5 hours of kneading at 55 ° C, the alkali is with In the same reaction vessel in which the acetic acid production was neutralized and added to the reaction mixture of the graft polymer happens, the Hropfpoly- water vapor is blown in with simultaneous distillation merisate melt dissolved in 3700 parts by weight of methanol, the methanol and the methyl acetate formed. and by adding 78 parts by weight of a methano- 5 It is a 6% aqueous solution of the modified Lischen sodium hydroxide solution transesterified. The um- polyvinyl alcohol obtained. A result of this solution Esterification is finished in 5 hours. The processing of poured films is milky-cloudy, similar to a film from takes place as described in Example 5. The modified base polymer used in the starting product; Polyvinyl alcohol has the following composition: However, its tear strength is many times greater than ,. ,,,,.,. "_ _" Ίο that of a film made from the parent polymer with the same Polyvinyl alcohol units 35.7% elongation Polyvinyl acetate units 0.9% _{The 6Γ} ^ _β ηε modified polyvinyl alcohol contains, Polyethylene glycol units 63.4% built into _{the Makromo} i _e kül, 20.7 percent by weight of poly Example 7 vinyl alcohol and 2.1 percent by weight of polyvinyl acetate. The starting material ¹⁵ is used which, as Working Example 5 wrote, prepared graft polymer solution. Patent claims: Saponification or transesterification 1. Further development of the process for the production 1000 parts by weight of the graft polymer solution are modified polyvinyl alcohols from a graft diluted with 1692 parts by weight of methanol. so polymer of one or more vinyl esters and To this solution, 30 parts by weight of a 78%, optionally other with vinyl esters mixed poly- Sulfuric acid, the merizable compounds dissolved in 30 parts by weight of methanol on polyalkylene are given. glycols according to Patent 1,081,229, marked characterized The reaction is characterized at a water bath temperature of that the graft polymer loading in a per se 58 ° C carried out with constant stirring and has been saponified or transesterified according to the usual 25 finished about 15 hours. that the resulting modified polyvinyl alcohol Then the sulfuric acid with methanoli- is already cold water-soluble, but less than shear sodium hydroxide neutralized and in the reaction 50 percent by weight of polyvinyl alcohol units mixture water vapor introduced, one containing methanol. Methyl acetate mixture is distilled off and an aqueous 30 2. The method according to claim 1, characterized in that Solution of the modified polyvinyl alcohol remains. draws that the mentioned graft polymers alkali The modified polyvinyl alcohol has the following admixtures to be partially saponified: Composition: 3. The method according to claim 1 and 2, characterized in that Polyvinyl alcohol units 46.3% indicates that graft polymers on poly Polyvinyl acetate units 2.8% 35 ethylene glycols are saponified or transesterified. Polyethylene glycol units 50.9% 4. The method according to claim 1 and 2, characterized in that . . indicates that graft polymers on water Example 8 or soluble oxyethylated polypropylene glycols Production of the starting higher homologue of polypropylene glycol, which is not claimed here, saponified Graft polymer ₄₀ b _between . be transesterified. In a kneader with reflux condenser 174 Ge 5. The method according to claim 1 and 2, characterized by parts by weight of polyethylene glycol, the 1% aqueous indicates that graft polymer has a viscosity of 4000 cP ^{on both sides solution at 20 0 C, in or simply on the} Terminal hydroxyl groups etherified 1275 parts by weight of methanol at 7O ⁰ C under nitrogen or dissolved esterified water-soluble polyalkylene glycols. 45 or on water-soluble polyalkylene glycol derivatives, 177 parts by weight are gradually added to this solution in which one or both hydroxyl groups are sub-dissolved by vinyl acetate, which contains 1.8 parts by weight of dibenzoyl peroxide mono- or polyfunctional amines or amides, and the reaction mixture is substituted or water-soluble Reaction kneaded for 30 hours at reflux temperature. products of polyalkylene glycols are saponified or interesterified with mono- or _ 50 polyisocyanates.
Partial esterification or transesterification _{& processes according to address and 2} , thereby With further kneading 20 wt features are at 5O ⁰ C, that the graft polymers in organic parts of a 15 weight percent solution of sodium or inorganically substituted water-soluble poly- hydroxide in methanol mixed into the batch. alkylene glycols are saponified or transesterified. © 009 677/467 11.60