JPH07500357A - Copolymers of maleic anhydride and acrylic acid useful in denture adhesives - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Copolymers of maleic anhydride and acrylic acid useful in denture adhesives Conventionally, regarding providing copolymers of maleic anhydride and acrylic acid, ( 1) without the need for excessive agitation; (2) copolymerization using non-toxic solvents; (3) from which a predetermined high molecular weight copolymer; (4) in the form of a uniform, fine white powder; (5) with most of the monomer remaining; (6) During the process, protective colloids are (7) The # agent can be easily recycled; Furthermore, this copolymer can be used for dentures. Completely inadequate in that it can be used effectively in adhesive compositions Met.

Therefore, the slurry polymerization process of the present invention uses ethyl acetate and aliphatic or fatty acids. A predetermined amount of maleic anhydride and acrylic anhydride in a co-solvent system containing a cyclic hydrocarbon. By copolymerizing lylic acid or methacrylic acid, maleic anhydride and acrylic Provides a uniform, fine, white copolymer powder of acid or methacrylic acid. present invention The copolymer powder of is particularly useful in denture adhesive compositions.

In the process of the invention, about 10-70 mol%, preferably 20-60 mol% maleic anhydride, 30-90 mol%, preferably 20-80 mol% acrylic acid or methacrylic acid and optionally up to about 25 mole % 01-C4 alkylbi methyl vinyl ether, preferably methyl vinyl ether, in the co-solvent system of the present invention. Copolymerization is carried out in the presence of a polymerization initiator under appropriate temperature and reaction time conditions.

Furthermore, the addition sequence of these monomers ensures that the polymerization mixture remains in accordance with the present invention throughout the reaction. Ensures retention of slurry form in the same solvent system.

The co-solvent system of the present invention has a boiling point less than (and more than 10°C) above the reaction temperature. about 20-95% by weight of aliphatic or cycloaliphatic hydrocarbons and about ethyl acetate. Contains 5 to 80% by weight. Suitable aliphatic and cycloaliphatic hydrocarbons for use herein include These include heptane, octane, cyclohexane, etc. Cyclohexane is preferred Delicious. More preferably, the co-solvent system of the present invention contains ethyl acetate from about 10 to 75% by weight and about 25-90% by weight of aliphatic or cycloaliphatic hydrocarbons. Even better Preferably, the co-solvent system contains approximately 25% by weight ethyl acetate and cyclohexane. Contains about 75% by weight.

The co-solvent system of the present invention has a synergistic effect on polymerization compared to each solvent alone. Tarasu. In particular, ethyl acetate itself is an unsuitable solvent for polymerization; This is because the copolymer dissolves in the solvent. In addition, it is produced in ethyl acetate. The molecular weight of the copolymer produced is very low, resulting in a semi-solid product. Similarly, Lohexane alone is inadequate as it forms an insoluble precipitate and is easily This is because it cannot be pumped. Furthermore, polymer powder isolated from cyclohexane The powder is heterogeneous and contains agglomerated particles. Conversely, ethyl acetate and cyclohexane Co-solvent systems allow copolymerization without the need for excessive agitation or protective colloids. provides a pumpable slurry. Additionally, such co-solvent systems are useful for copolymer formation. It is possible to eliminate trace amounts of residual maleic anhydride monomer from products.

The use of predetermined ratios of each solvent in a co-solvent allows for a wide range of molecular weights. A copolymer is provided. Therefore, the ethyl acetate contained in the co-solvent system of the present invention The amount of tate must be tightly controlled, as ethyl acetate is copolymerized. This is because it has the effect of reducing the molecular weight of the remer and further solubilizing the copolymer. . For example, the use of 66% by weight ethyl acetate in the co-solvent system is approximately 3% by weight of ethyl acetate. produced a polymer with a weight average molecular weight of 0,000, while under similar reaction conditions, The use of 10% by weight ethyl acetate results in a weight average molecular weight of approximately 400,000. Produce copolymers.

A co-solvent system containing ethyl acetate and cyclohexane is particularly good; , because their boiling points are very similar (76°C and 80°C, respectively).

This allows the co-solvent system to be easily recycled by distillation. . Mixtures of solvents with widely different boiling points are undesirable; This is because low-boiling point solvents become more abundant.

The boiling point of the solvent used here is usually at least 10° above the polymerization temperature to be carried out. Preferably 20" or more (preferably at about 65°C). Such a difference aids in controlling the effects of exothermic polymerization reactions using chemical agents and further eliminates the need for pressure reactors. vinegar.

The total monomer content in the co-solvent systems of the present invention is typically about 10-30% by weight, preferably or about 20 to 25% by weight. At the darning concentration, the slurry is heated at approximately 50° It is also possible to pump the reactants under normal agitation at a reaction temperature of between 150'C. It is possible.

The polymerization initiator used in the process of the present invention is, for example, t-butylperoxybiber or L-amyl peroxy esters, such as L-amyl peroxypivalate, or , consisting of a dialkyl peroxide, e.g. di-decanoyl peroxide selected from the group, but also other traditionally known initiators for free radical polymerization. Can be used similarly.

In carrying out the polymerization process of the present invention, the maleic anhydride reactant, the initiator and A solution containing a co-solvent is pre-charged into a suitable reactor and acrylic acid or methacrylic acid is added. Continuously feed the acid into the pre-filled solution over a period of about 0.3 to 10 hours, and Hold at 0° to 80°C. Optionally add the alkyl after adding the acrylic acid reactant. Add vinyl ether monomer. Then, this polymerization mixture was further heated for 15 to 90 Hold at reaction temperature for a minute to complete addition of all monomers. Several types of initiator booths It is possible to introduce the ester after or during the feeding of the comonomer.

The invention is illustrated by the following example.

■−Soil Ethyl ace-cylohexane Ox 12 resin reaction kettles, sealed with stirrer, reflux condenser, Nt inlet tube and rubber septum. equipped with an inlet for initiator injection. This reaction kettle contained 49.0 g (0.50 mol) ) of maleic anhydride (MA), 275 g (75% by weight) of ethyl acetate ( EA) and 92 g (25% by weight) of cyclohexane (CH). This mixture Stirring of the mixture was started and the system was purged by bubbling in N2 for 30 minutes. this During this time, the maleic anhydride was completely dissolved.

The reaction mixture was then warmed to 65°C and 0.3 mj! Luperso l) injecting 11 (Pennwalt) through the septum; Polymerization started.

At the same time, 73.0 g (1.0 mol) of acrylic acid (AA) was started dropping, and at 3 o'clock It continued over time. During this time, Lupersol l1 was added to A A was added at a rate of 0.3 tal of initiator every 30 minutes of addition. all additions After completion, the resulting mixture was held at 65°C for 2 hours.

After 15 minutes, the reaction mixture becomes white and thus forms a creamy slurry of uniform thickness. was formed and was pumped from the reaction kettle to a filtration unit. filter the slurry , the polymer product was dried in a forced circulation oven at 65°C for about 12 hours. This weight The combined product is a uniform, fine white powder with a weight average molecular weight (G) of approximately 47,000. (determined by PC). The Ig polymer was dissolved in 5+wf acetone. When treated with triphenylphosphine, the maleic anhydride becomes a polymer. It was shown that there was a complete conversion to

5l 2 earth The method of Example 1 was carried out to provide copolymers of various compositions and molecular weights.

The results of Examples 1-11 are shown in Table 1 below. In examples 9 and 10 therein, the third The monomer butyl vinyl ether or methyl vinyl ether is mixed with acrylic acid. was introduced after the addition was complete.

Kitakami 11” Reni LL The method of Example 1 was carried out using different solvents. You will get the following result, which can be downloaded below. It is shown in Table 2 below. Among them, ethyl acetate, cyclohexane, toluene, L - A single solvent containing methyl butyl ether and xylene will result in a non-uniform slurry and and polymer powder, which compared to that obtained in the co-solvent system of the present invention. It was difficult to process and very little useful product was obtained.

The figure shows the lbs vs sa A graph of the number of cycles is shown.

Maleic anhydride and acrylic acid (or methacrylic acid), optionally C8-C4 alkyl A mixed partial salt of a copolymer containing rubinyl ether whose weight average molecular weight is about 30,000 to 400,000, preferably about 50,000 to 350,000 To provide a denture adhesive that is

The copolymer suitably comprises about 10 to 70 mol%, preferably 20 to 60 mol%. of maleic anhydride, about 30 to 90 mol%, preferably 40 to 80 mol% of acrylic methacrylic acid, and 0 to 25 moles of C, -C, alkyl vinyl ether. Including le%.

Partially mixed salts contain calcium/sodium salts, in which calcium and sodium The equivalent ratio of lithium cations is 2:1 to 10:1, preferably 3:1 to 7:1. , the degree of initial neutralization of carboxyl groups is from 0.5 to 0.95, preferably from 0.7 to It is 0.9.

The adhesive copolymer of the present invention is converted into its mixed partial salt, which is less than 250μ Used as a dry powder with a particle size, more preferably from about 5 to about 200 microns. Preferably.

The denture adhesive here is a liquid containing the dry powder of the above adhesive copolymer as a mixed salt. A homogeneous or creamy paste suspension or colloidal dispersion is obtained in a body-based carrier. Provided by incorporation by mixing until mixed, usually about 20 minutes to about 5 hours. It will be done.

The resulting composition has an effective adhesion amount of the adhesive copolymer mixed salt that is consistent with the final composition. Usually about 5% to about 50% by weight, preferably about 10% to about 35% by weight.

Here, suitable mixed partial salts can be obtained by reacting the copolymer with a suitable base. Calcium/sodium mixed partial salts prepared by Preferably mixed The equivalent ratio of calcium cations and sodium cations in the partial salt is 2:1 to 10. :l, more preferably in the range of 3:1 to 7:l (based on molar ratio, calcium The ratio of sodium cation to sodium cation ranges from 1:1 to 5:1, more preferably 1.5: 1 to 3.5:1). The sum of cations in the mixed partial salt is the total of all cations in the copolymer. The degree of neutralization of the first carboxyl group in the part is 0.5 to 0.95, preferably 0.7. It should be sufficient to show that ~0.9. All maximum in the copolymer In determining the first carboxyl group, the anhydride group has two first carboxyl groups. It is assumed that the compound contains a ru group.

The base carrier portion of the composition typically includes a water-soluble or partially water-soluble hydrophilic carrier; It has the ability to swell when exposed to moisture, forming a sticky mass. Kakaruru Responsibility Body materials include natural and synthetic rubbers, viscous liquids, gels and powders. in the composition Among the suitable ones used as base carriers are karaya gum, gelatin, traga Gum canth, gum arabic (acacia), gum shiraz, algin, sodium alginate A mixture of thorium, tragacanth, methylcellulose, petrolatum and mineral oil, Glycerin, polyvinylpyrrolidone, K-30 and Ni-90, carboxymethyl These include cellulose, ethylene oxide polymers, of which the preferred are Loratum and mineral oil in a ratio of 40:60 to 60:40.

The adhesive copolymer of the present invention can be used as a single adhesive composition in a denture adhesive composition. , or as a joint adhesive with other adhesive materials. Adhesion When present, additives usually comprise about 5-20% by weight of the composition.

Suitable adhesive additives include natural or synthetic polymers, such as cellulose , gum karaya, gum tragacanth, gum arabic (acacia), carboxymethi cellulose or their salts, polymethacrylate, polyvinylpyrrolidone, polymer ribinyl acetate, or a mixture of any of the above.

The compositions of the present invention are particularly useful for attaching dentures and are also useful for attaching dentures to tissues. It can also be used in surgical processes (methods) that require temporary replacement of. denture fitting As an adhesive, it takes less than over a sufficient temperature range, e.g. 5° to 50°C, the compositions of the present invention Stability is particularly desirable. Increased adhesive strength and thermal stability make this composition It retains its adhesive properties for hours, ie up to 24 hours.

Some representative formulations in which adhesive copolymers are added in effective amounts up to about 50% are as follows: Shown below.

Sodium carboxymethyl cellulose (adhesive additive) 20 Colorant 1 Flavoring agent 0.5 Product of the present invention X 2a, 5 Paste Ostomy-Os to Lock-1 U Mineral Oil (Heavy) 35 Glycerin 5 Polyvinylpyrrolidone 2゜ Carboxymethyl cellulose 5 Tosylate 0.5 Substance of the present invention 34,5 ゛ - Heavy JLt Tragacanth rubber 40 Arabia (Acacia) Gum 20 Spearmint (Dutch mint) oil 0.05 Substance of the present invention 39.05 -T The copolymer was converted to its mixed partial salt as follows. 250 g of copolymer mjl! Fill a round-bottomed, three-bottle flask with 90 g of isopropyl alcohol. Filled. Stir the contents to prepare a slurry and add 9.59 g of calcium hydroxide. was added slowly over 15 minutes with stirring. Then 2.08 g of water Sodium oxide dissolved in 38 g of water was added with stirring. This mixture The mixture was heated at 45°C for 1-1/2 hours without stirring. The pH of the liquid phase is 4.8 It was 9. The mixture was filtered and the precipitate was placed in an oven at 65°C overnight. Dry.

Instron's Nohe 11 A dry mixed salt of MA/AA copolymer was added to a number 60 mesh sieve (250μ ) and the resulting powder is then machined into a petrolatum base. Disperse at a temperature of 55-65 °C with mechanical stirring, then cool to 20-25 °C. Rejected. The ratio of copolymer to base was 1:2 by weight. obtained chestnut The foam dispersant was collected as the desired adhesive composition.

Additionally, adhesive compositions of dry mixed salts of copolymers, maleic anhydride and methylvinyl GANTREZ MS-9 is a mixed salt copolymer available in the ether market. No. 55 was prepared for testing in a manner similar to that described above.

A 2g sample of each of the above prepared compositions was subjected to the Instron test by the following method. The adhesive properties were evaluated using: In the first step, the upper plate of the Instron device was and the lower plate were both set to the zero position. Then remove the upper plate by 0.06 inches. and set the upper cycle limit of the Instron indicator to this position.

The upper plate was then lowered and the lower cycle limit was set. its lowest lower position In this case, the top plate was located 0.03 inches above the bottom plate.

Using the Instron set determined in this way, then lift the upper plate. , 2g of the test sample was placed on the surface of the lower plate to a thickness of 1/16 to 1/8 inch. Spread it homogeneously; then coat the artificial saliva on the sample, just this Applied as possible.

Set the Instron crosshead forward at a crosshead speed of 0.2 in/min. was cycled between the set limits. Instron chart at a speed of 2 inches/minute Set in 1 degree concatenation mode, compress and compress every 5 to 100 cycles. Adhesion strength was recorded.

After completing 100 cycles, stop the upper plate and start the next adhesive test. Before lifting the surface high enough to clean it.

Analyze each record, 1st, 5th, 10th, 20th, 40th, etc. 10 The adhesion force (lbs) for the 0th cycle is shown and then plotted on the drawing. .

The results of this study are shown in the figure. This data is based on the corresponding components useful as denture adhesives. containing the copolymer composition of the present invention compared to the polymer composition (MS-955). The adhesive formulation has excellent initial adhesive strength and long-term adhesive strength. It is shown.

I! ]1 'S'g7ullt international search report Continuation of front page (81) Designated countries EP (AT, BE, CH, DE.

DK, ES, FR, GB, GR, IT, LU, NL, SE), AU, BR, CA , FI, J.P., K.R., N.

(72) Inventor: Rosin Ropart Bee, New Chassis, United States of America 07436 Oakland Payne Drive (72) Inventor Prochocca Christina New Chassis, United States 07076 Scotch Plains Mountain Avenue 2305 (72) Inventor: Halder Rama Kay, New Chassis, United States of America 07869 Randolph Sweetwood Drive 8 (72) Inventor Gangadharan Balgopal Newshire, USA sea state 07006 Caldwell Westville Avenue 87 (72) Inventor Brogyse William E Newshire, United States of America sea state 07446 Ramsey East Oak Street 16

Claims (3)

[Claims] 1. About 5-80% by weight ethyl acetate and about 20-95% by weight aliphatic or fat. A co-solvent system containing a cyclic hydrocarbon whose boiling point is at least 10°C higher than the reaction temperature. In the system, about 10-70 mol% maleic anhydride, about 30-90 mol% Acrylic acid or methacrylic acid and 0 to 25 mol% C1-C4 alkylvinyl The ether is copolymerized at about 50°C to 150°C in the presence of a free radical initiator. The pumped slurry of the copolymer is allowed to live in the co-solvent system, and from this The copolymer is recovered as a uniform, fine powder with almost no residual maleic anhydride. Ru A predetermined weight average of about 10,000 to 1,000,000 Optionally containing Cl-C4 alkyl vinyl ether suitable for denture adhesives having a molecular weight of Copolymers of maleic anhydride and acrylic or methacrylic acid. 2. A denture adhesive composition comprising the copolymer of claim 1. 3. 3. The denture adhesive of claim 2 comprising a mixed partial salt of the copolymer of claim 1.