JPS59189121A - Hydrophilic graft polymer - Google Patents

Abstract

PURPOSE:A hydrophilic graft polymer suitable for use as a water-swellable sealing material or the like, prepared by bonding a polyalkylene oxide to an epichlorohydrin elastomer as a trunk polymer through carboxylate ester linkages. CONSTITUTION:A polyethylene oxide dicarboxylic acid of an MW>=several thousands (e.g., PEO acid #4,000, a product of Kawaken Chemical Ltd.) is dissolved in an organic solvent (e.g., dimethylformamide or dimethyl sulfoxide). The carboxyl groups are neutralized by an alkali metal hydroxide (e.g., sodium hydroxide or potassium hydroxide) to form a solution of a carboxyl group-terminated polyalkylene oxide salt. This solution is mixed with an organic solvent solution of an epichlorohydrin elastomer (e.g., Hydrin 100, a product of Goodrich Chemical Co.), and the mixture is reacted at about 40-100 deg.C in an inert gas atmosphere to obtain a graft copolymer.

Description

Detailed Description of the Invention The present invention provides a shrimp chlorohydrin elastomer obtained by reacting the shrimp chlorohydrin elastomer with an alkali metal salt of a polyalkylene oxide having at least one terminal carboxyl group in a solution. This invention relates to a graft polymer in which the main polymer is a polyalkylene oxide bonded to the main polymer by a carboxylic acid ester bond, and the branch polymers are polyalkylene oxides.

The graft polymer of the present invention has unique properties as a hydrophilic elastomer.

In the present invention, "epichlorohydrin elastomer" refers to a single shrimp chlorohydrin elastomer that has a molecular weight high enough to be processed and molded into a vulcanized rubber product using ordinary rubber processing machinery. and copolymers based on shrimp chlorohydrin and alkylene oxide and/or small amounts of other epoxide monomers (E, J).

VtmdcnAhcg, ”)(=J-Q,tJbrv
* En, Cy, JCLyn, 'pac&-nlr evening, 11 3~%Bshi9, WJL et al. 2. N, Y
, 1979. (See 8ItdL 8゜P, 568).

These shrimp chlorohydrin elastomers are typically produced by solution polymerization using coordination polymerization catalysts.

In particular, shrimp chlorohydrin homopolymers and copolymers of shrimp chlorohydrin and ethylene oxide with a molar ratio of approximately 1:1 are synthetic materials that have excellent properties such as heat resistance, aging resistance, and flame retardancy. It is manufactured industrially as rubber.

These elastomers can be used as vulcanizing agents such as diamines, imidacillin, thiourea, etc. with chloromethyl groups.
Vulcanized rubber can be obtained by using compounds that are sensually reactive and heating at temperatures usually above 150°C.

On the other hand, we attempted to modify shrimp chlorohydrin elastomer by utilizing the reactivity of the chloromethyl group to introduce various other substituents.

Many attempts have been made to do so (E, J, V
antl, e, nlr<hgnior Fl'J Document P,
579).

Furthermore, attempts have also been made to modify shrimp chlorohydrin elastomer by grafting reactions.

Some are being done. Namely, styrene.

The grafting of methyl methacrylate, acrylonitrile, and vinyl chloride monomers has been carried out by a radical polymerization mechanism using a divine polymerization initiator (US 14-
Patent No. 3,546,321, No. 3,627.839, German Patent Publication No. 3,632,84.0, German Patent Publication No. 2,
No. 147, 290). Also, living polystyrene
By the camping reaction between the anion and the chloromethyl group
,1゜fcvy! ? L+, J, A, h'+"',
■]σJ-f---23,57(1,982);
Y, M,'n,, -4. ．． H1I(i-yy<
Pox a, T, Kaba&a.

Y, U"", J, PJy--n ScL, A-1,6,
2773 (]9'68)), or by reaction of polystyrene carboxylic acid obtained by quenching the pink polystyrene anion with CO2 and chloromethyl groups (M, A,, MtLLI-If,
H, 9uhf, J, A.

Bw-9-, PJy-=-23,57 (1982)
) ,Each.

A granoid polymer consisting of a shrimp chlorohydrin elastomer trunk polymer and a polystyrene branch polymer has been synthesized. As described above, only epichloro is known, and these are structurally and in terms of properties different from the granodo-m combination of the present invention, which has a hydrophilic polyoquine algylene chain as a graft chain. It's completely turned into a dormitory.

In the production of the graft polymer of the present invention, the polyalkylene oxide (hereinafter referred to as PA, 0 acid) having a terminal carboxylic group used as another reaction component is ethylene oxide, propylene oxide, butylene oxide, etc. ring-opening homopolymerization or copolymerization (including block copolymerization) of alkylene oxides of
From polyalkylene glycols produced by
Known methods (e.g. K, 'i/<c&, E
, 13+, y, em, dedicationkeu'f3d沁Lnyu, 6
91 (1979)).

In this case, it goes without saying that a product having carboxyl groups at both ends is produced, but if one starts from a polyalkylene glycol with one end blocked in advance with an ether bond, etc., it will have a carboxyl group only at the -terminus. Polyalkylene oxide can be obtained. In particular, polyethylene oxide dicarboxylic acid synthesized from polyethylene glycol is
Products with various molecular weights up to nearly 1,000,000 can be obtained as ready-made products (ω1 chemical PEO acid). These PAO
Any acid can be used, but for its sufficient modifying effect on the shrimp chlorohydrin elastomer, especially its high water absorption properties (- is from polyethylene oxide with a molecular weight of several thousand or more). Preference is given to using carboxylic acids consisting of:

When producing the graft polymer of the present invention, in order to facilitate the reaction between the chloromethyl group in the shrimp chlorohydrin elastomer and the carboxyl group 1 in the PAO acid, the carboxyl group in the PAO acid must be It is necessary to neutralize it with an alkali metal hydroxide to form a carboxylate salt.

The PAO acid is dissolved in an organic solvent, preferably the solvent used in the subsequent reaction with the epichlorohydrin elastomer, and dissolved in a solution of an alkali metal hydroxide, particularly in an aliphatic alcohol such as methanol, ethanol, etc. This can be done by determining r'+Mi using a 6 dilute solution. The neutralization point can be easily determined by using a suitable indicator, a PH meter, an automatic potentiometric lG'il meter, and the like.

The graft polymer of the present invention can be prepared by dissolving shrimp chlorohydrin elastomer in a solvent, and adding thereto a solution of the PAO salt prepared as described above.

It can be produced by stirring at a suitable temperature for a suitable period of time.

The solvent used must dissolve both reactants and be inert to the reaction. For example, ordinary hydrocarbon-based organic solvents such as aromatic hydrocarbons or halogenated hydrocarbons can be used, but in order for the two reactions to proceed sufficiently, considerably high temperatures and extremely long reaction times are required. do. Therefore, it is generally known to promote nucleophilic substitution reactions. Preference is given to using aprotic polar organic solvents, such as dimethylformamide or dimethylsulfoxide. The amount of solvent used goes without saying.

The amount must be such as to provide sufficient stirring of the reaction mixture under the reaction conditions.

The reaction temperature can be from room temperature to the boiling point of the solvent used, but in order to prevent excessive decomposition of one reactant and to achieve sufficient reaction in a reasonable time,
A temperature of °C is preferred. For similar reasons, it is desirable to conduct the reaction under an inert atmosphere such as nitrogen gas.

Recovery of the reaction product from the reaction mixture can be readily accomplished by conventional methods used for recovery of solid polymers from polymer solutions. Additionally, residual unreacted PAO acid in the reaction product can be removed by washing the product with water.

The presence of polyoxyalkylene graft chains in the reaction product can be confirmed by measurement of infrared absorption and nuclear magnetic resonance absorption (NMR), and the bonded chain is NIV.
It can be easily quantified by IR or elemental analysis.

Since the graft polymer of the present invention is produced based on a bonding reaction between polymers and earth, theoretically, the molecule l is the bonded shrimp chlorohydrin elastomer and P.
It can be considered that it corresponds to the sum of 14t molecules of AO acid, but in reality, some cleavage of the molecular chain of shrimp chlorohydrin elastomer may occur during the two reactions, resulting in a slight decrease in the overall molecular weight. There is. However, industrially produced shrimp chlorohydrin elastomer generally has a high molecular weight of several hundred thousand, and as long as such a high molecular weight polymer is used as a raw material and appropriate reaction conditions are selected, .

Graft polymers can be obtained with molecular weights that are high enough, eg, even higher, to be suitable for many applications.

The grafting rate expressed as a weight percentage of polyalkylene oxide as a branch polymer to shrimp chlorohydrin elastomer as a trunk polymer depends on the type of shrimp chlorohydrin elastomer and PAO acid used, especially the molecular weight of the two components, and the ratio of the two components used. By changing the reaction conditions such as the reaction temperature and reaction time, the solvent can be varied over a wide range from a few percent to more than 100%, but from the point of view of the physical properties of the product and the mechanical properties of the lees, Preferably it is less than 50%.

In the process of producing the graft polymer of the present invention, only a small number of chloromethyl groups in the shrimp chlorohydrin elastomer are converted into carboxylic acid ester bonds by reaction with PAO acid, and most of the chloromethyl groups are It remains unreacted. Therefore, the graft polymer of the present invention is exactly the same as in the conventional shrimp chlorohydrin elastomer (2).

Vulcanization using the various vulcanizing agents mentioned above is possible. Processing such as mixing, molding, and vulcanization of these vulcanizing agents, as well as various compounding agents such as vulcanization aids, fillers, and anti-aging agents, is a general rubber processing method that uses ordinary rubber processing equipment. You can follow the instructions.

The graft polymer of the present invention has two highly hydrophilic polyoquine alkylene chains,
In particular, it has interesting properties as a water-absorbing elastomer due to the grafting of polyoxyethylene chains.

Various applications, e.g. water-swellable sealing materials.

It has potential applications in a wide range of fields, including hygroscopic coatings, medical polymer products, adhesives, feed, and two-separation membrane materials.

Next, the present invention will be explained in more detail based on examples.

Example 1 Approximately 3. Polyethylene oxide dicarboxylic acid with an average molecular weight of 500 (PEO acid #40 manufactured by Yoken Chemical ■)
00)0.50f was dissolved in 25 mg of DMF and the solution was neutralized by titration with 02IN methanol solution of potassium hydroxide using phenolphthalene as indicator. On the other hand, t,ooy shrimp chlorohydrin elastomer (manufactured by Goodlynch Chemical, I-1$m
IOO, shrimp chlorohydrin homopolymer) to DM'F
The solution dissolved in 2 Sml was placed in a four-way flask equipped with a thermometer, nitrogen inlet tube, stirrer, and reflux condenser, and the above neutralized solution was added, followed by 6 hours under a nitrogen stream.
Heated at 0°C for 20 hours. The reaction mixture was poured into water to precipitate the reaction product, and the separated precipitate was thoroughly washed with water and then dried in a vacuum dryer at 40°C to a constant weight. The weight of the rubbery product thus obtained was 110y. This product was purified by reprecipitation with a THF-water system, and then NMR
The grafting rate determined from the spectrum was 79%. This value corresponds to 166 mole % expressed as a mole percentage of ethylene oxide units in the branch polymer to shrimp chlorohydrin units in the trunk polymer.

Example 2 Polyethylene oxide dicarboxylic acid with an average molecular weight of about 8.500 (PEO acid $6000) 0507
was dissolved in 20 nte of dimethylnulphoxide and neutralized as in Example 1.

1007 shrimp chlorohydrin elastomer (above)
ri”-”n100) 25m/? Add the neutralizing solution described in "2," and add the neutralizing solution described in "2.
Stirred at °C for 24 hours. After treatment in the same manner as in Example 1, 2 reaction product 1157 was obtained. The grafting rate determined by NMR spectrum of the purified product was 22
It was 8% by weight (478% by mole).

Example 3 Same as Example 2 except that the reaction temperature was 80°C and the reaction time was 6 hours, but the reaction time was 1.20! A rubbery reaction product of i' was obtained. The product was insoluble in the solvent, but became soluble after several minutes of rolling at room temperature using a small laboratory roll machine. The grafting rate of the purified product was 3 [7% by weight (666 mol%). The THF solution was poured onto a glass plate to obtain a transparent cast film with rubber-like elasticity. This was immersed in water at 25°C for 7 days, and the water absorption rate was determined as the weight increase rate relative to the weight before immersion, which was 53.
%Met.

Example 4 Product [117] was obtained in the same manner as in Example 3, except that the reaction conditions were 60°C and 8 hours. The grafting rate after solubilization by wiping was 152% by weight (31.9% by mole), and the water absorption rate of the cast film was 31%.

Example 5 Shrimp chlorohydrin As an elastomer, a 1:1 copolymer of shrimp chlorohydrin and ethylene oxide (manufactured by Gutdrich Chemical, If, 7it+, 20
A rubbery product []32 was obtained in the same manner as in Example 3 except that Q) was used. This /:1゛composition is also.

It was insoluble as it was, but after hanging, it became 'iTJ soluble. The grafting ratio of the purified product was 18% for C, which was 456% when expressed as a molar percentage of the total ethylene oxide units of the trunk polymer and branch polymers to the shrimp chlorohydrin units. The water absorption rate of the Gas I film obtained from the THF solution was 123%.

Example 6 Same conditions as Example 3 except that shrimp chlorohydrin Elas L.mer (Nippon Zeon Gbk3 LQQ, estimated to contain allyl glycidyl ether as a comonomer) with 29% chlorine content was used. The reaction was carried out below to obtain 123 g of a rubbery product. This product remained insoluble in the solvent even after rolling. The grafting rate determined from the chlorine analysis value was 284% by weight. The water absorption rate determined for the rolled sheet was 65%.

125-

Claims (1)

[Claims] 1) Shrimp chlorohydrin elastomer is obtained by reacting shrimp chlorohydrin elastomer with an alkali metal salt of polyalkylene oxide having at least one carboxyl group at one end in a solution. A graft polymer whose branched polymers are polyalkylene oxides linked by acid ester bonds.