HU194298B - Polimer-based composition applicaple as glueing-pin - Google Patents

Abstract

The composition according to the invention is characterized in that a mixture of sorbitol, benzaldehyde, acetone or ethyl methyl ketone in a ratio of 1: 0.5 to 2.5 /: / 0.5 to 150 / molar ratio of 40 to 70 ° C for 1 mol of sorbitol From 0.5 to 2 moles of washed and dried, then milled sorbitol acetal isomeric mixture, obtained in the presence of inorganic acid for 8 to 20 hours, from 1 to 20% by weight, 15 to 50% by weight of an adhesive polymer having a molecular weight between 10000 and 70000, preferably vinyl pyrrolidone homo or copolymer, methacrylate copolymer, 5-60% by weight solvent, preferably aliphatic mono- or polyalcohol, dimethylformamide or a mixture thereof, or water, 0-50% filler, preferably talc, titanium dioxide and 0-1% by weight of other additives such as coloring and / or fragrance. -1-

Description

BACKGROUND OF THE INVENTION The present invention relates to a glassy adhesive composition having a good shelf life and excellent adhesive properties in the form of an adhesive stick.

There are many methods known in the art for preparing adhesive typefaces. These glue sticks are well suited for bonding paper, leather, textiles, polystyrene foam, wood surfaces. The condition of good bonding is that one of the surfaces to be bonded must be vapor-permeable. The advantage of adhesive sticks over conventional liquid adhesives, primarily in tubular form, is its easy, clean handling and quick drying time.

The sticks are made by suitable selection of a generally polymer based adhesive such as polyvinylpyrrolidone, N-alkyl polyvinylpyrrolidone, vinyl acetate vinyl pyrrolidone copolymer, polyvinyl alcohol, 1,4-dichlohexane-dimethanol and sebadic acid polyester, maleic anhydride-vinyl methyl copolymer, hydrolyzed crontonic acid-vinyl acetate copolymer, etc. are dissolved in a solvent such as water, an organic solvent, and mixed with water and a water-miscible organic solvent, , a thickener is added and the hot melt is molded, and after cooling, the composition is removed from the mold to receive a shape-holding pin.

As gelling agents thickening agents include metal stearates, small molecule and macromolecular esters, pL benzal sorbitol and dibenzal sorbitol, tribenzal sorbitol and waxes, e.g. mont resin esters, etc. - used most often

One type of glue sticks uses a benzal sorbitol gelling agent.

Such compositions are disclosed in Japanese Patent Publication No. 74557332. European Patent Publication No. 24864 also discloses the use of dibenzal sorbitol in the manufacture of an adhesive stick. Japanese Patent Application Laid-Open No. 2636332 also uses this type of compound.

The disadvantage of these gelling agents is that they do not practically gel in aqueous compositions because they have very poor water resistance and precipitate upon exposure to water.

Monobenzal sorbitol alone can be used as a gelling agent in an aqueous solvent medium, but is not industrially synthesized and is therefore not used in the manufacture of adhesive sticks. In practice, the preparation of benzal sorbitol is difficult because the monobenzal sorbitol formed during the synthesis of the compounds gives the starting material a gel with benzaldehyde, and at the same time, only poor dibenzal yield can be obtained. The disadvantage of the adhesive sticks containing the benzal sorbitol type gelling agent (dibenzal and tribenzal sorbitol) is that they are poorly stored, i.e. their good properties are degraded during storage and that it is very difficult to obtain a stick having compositions of this type having a sufficient hardness.

One of the major failures of commercially available stearates containing stearate or other thickener is that the stin becomes soft and sticky during storage and long-term use.

Attempts have been made to produce an adhesive, composition, or adhesive stick that is free of the disadvantages listed.

Such an adhesive composition can be obtained using only a special gelling agent

It has now been found that if the gelling agent used in the composition is a mixed condensation product of acetone or ethylmethyl ketone, benzaldehyde and sorbitol, i.e. a mixture of condensed compounds, an adhesive stick with high storage capacity and good strength can be prepared.

In the preparation of the gelling agent, sorbitol is used in a molar ratio of benzaldehyde to aliphatic ketone of 1: (0.5-2) to 0.5-150).

The gelling agent used in the present invention consists mainly of a mixture of the compounds of formula (I) (H) or (III) wherein R is methyl, R1 is methyl or ethyl.

The gelling agent in the composition of the present invention has the advantage that while the di- and tribenzal sorbitols are soluble in organic solvents only, the compounds used in our invention are also highly soluble in water-organic solvents.

Due to their high solubility, the mixture of sorbitol acetate in the adhesive composition of the present invention can be used in a higher weight ratio and thereby achieve better internal annealing.

The composition or stick of the present invention, as a result of the foregoing, does not pull fibers, even on thin paper, it can be applied in a very thin layer - without waving or tearing the paper.

In the adhesive composition, the gelling agent is used in an amount of 1 to 20%, preferably 4 to 8% by weight.

The basic component of the adhesive composition is the adhesive polymer. This is added at 5 to 50% by weight to the composition.

As adhesive polymers, vinyl homo- and copolymers such as polyvinyl alcohol, polyvinyl acetate, polyvinylpinnolidone, polyvinyl ether, vinylidene chloride or vinyl chloride are homo- and copolymer, polyvinyl ether, acrylate or methacrylate copolymer, copolymer of vinylpyrrolidone and styrene, copolymer of vinyl acetate and acrylate or methacrylate, and artificial and natural rubbers, polyacrylic acid or polymethacrylic acid, their esters, copolymers of poly (acrylonitrile), polyurethane, polyvinyl ether and maleic acid, cellulose esters, ketone resins, natural polymers such as gum rhodophane, carrageenan, alginate, and the like. It can be used. However, a mixture of these homo- and copolymers can also be used.

The adhesive polymer used may have a molecular weight in the range of 10,000 to 70,000, preferably 30,000.

The third mandatory component of the composition is the solvent. The amount may be in the range of 5 to 60% by weight.

A solvent may be a mixture of water and an organic solvent. In the latter case, it is preferable to choose a solvent having an evaporation index close to that of water.

An additional requirement for organic solvents is that they should not be harmful to health or odorous. A mixture of organic solvents may also be used.

Preferred solvents include butyl glycol, dimethylformamide, toluene, xylene, and the like.

Optionally, a filler, coloring agent, preservative, and perfume may be added to the composition.

Suitable fillers include barium sulphate, chalk or dolomite powder, bentonite, talcum, kaolin, alumina or - hydroxide, dnk-oxide, magnesium oxide or - hydroxide,

194.298 Aluminum sulphate, calcium sulphate, zeolite, etc.

Dyes and pigments can be used to color the adhesive composition.

Accordingly, the present invention relates to a polymer based adhesive composition, preferably in the form of an adhesive stick, characterized in that the compounds obtained by condensation of benzaldehyde, acetone and sorbitol are from 15 to 50% by weight of 10,000 to 70,000 5 to 60% by weight of a solvent, preferably an aliphatic mono- or poly or alcohol, dimethylformamide, a mixture of water and, if desired, additives such as 0 to 50% by weight. filler and 0-1 weight /? contains coloring and / or perfume.

According to the invention, the adhesive composition is prepared by condensing sorbitol, benzaldehyde and acetone or ethylmethyl ketone in a molar ratio of 1: (0.5-2.5) (0.5-150) to 40-70 ° C. Per mole of sorbitol in the presence of 0.5 to 2 moles of inorganic acid catalyst for 20-40 minutes with constant stirring and cooling, the resulting mixture is washed with water, bases, sodium bisulfite and water again, dried and ground.

The reaction was initiated by stirring a concentrated aqueous solution of sorbitol with a mixture of benzaldehyde and acetone. To this mixture was added sulfuric acid with constant stirring and cooling. The condensation was continued at 40-70 ° C until the mixture thickened. The mixing is stopped and the mass is allowed to cool to room temperature. After standing at room temperature for 8 to 20 hours, preferably 10 to 12 hours, the reaction is continued and the presence of excess aliphatic ketone is prevented from aggregating into the crude product. Upon completion of the reaction, a soft gelatinous material is obtained, from which the benzaldehyde and the acid can be washed off with copious amounts of water and alkali or sodium bisulfite. The acid and benzladehyde-free material thus obtained is preferably dried at 50-100 ° C. The powder product thus produced retains its gelling properties over a very long period of one year, even after storage.

The material thus obtained contains a mixture of monobenzal and dibenzal alkylidene sorbitol.

Using the gelling agent, the adhesive elevator of the present invention is prepared as follows.

A) The gelling agent is dissolved in an organic solvent, preferably butyl glycol and / or dimethylformamide, at a temperature not exceeding boiling point of the solvent at 2-5 ° C, and 30 to 70% by weight of the adhesive polymer is added. dry solids solution at 40-90 ° C, homogenize the mixture, optionally add the additives, fill the mixture and cool,

B) To a solution of the adhesive polymer in an organic solvent solution containing 30-70% by weight of dry solids, the fine powder gelling agent is mixed in small portions at 40-90 ° C, the mixture is homogenized, optionally mixed and the mixture is filled and cooled.

C) Dissolve the adhesive polymer in a mixture of water and organic solvent, add a fine powder gelling agent to the 30-70 wt.% Dry solids solution, reflux to 30-70 wt.% Of the organic solvent. then, if desired, an additive and an organic solvent or aqueous mixture are added thereto, followed by filling and cooling.

The adhesive composition of the present invention has the following advantageous properties:

- easy to produce economically; - storing longer than known compositions without changing the properties and consistency of the adhesive; - being applied on very thin paper in a thin layer without wrinkling or tearing the paper; - aesthetically pleasing than other similar compositions.

The invention is illustrated by the following examples.

Example 1

Weigh 48 ml of water into a 500 ml flask fitted with a thermometer, a water bath and a mechanical stirrer, and dissolve 144 g of sorbitol in it while heating at 40 ° C.

Then, 146 ml of acetone and 80 ml of benzaldehyde were added to the solution with vigorous stirring. Two phases were observed, which were 40 ml cc. the sulfuric acid disappears even after the addition is added during cooling and the reaction mixture is homogeneous.

A slight heat build-up was observed during the addition, but the temperature of the reaction mixture was maintained at 50 ° C. Stirring is continued until the reaction mixture begins to thicken. The stirrer was then stopped, removed and the material covered for 10 hours. The activated, solidified gel phase is sliced and mixed with 1500 ml of water to form a thick paste. The solid was collected by filtration and stirred again at pH 8-9 after addition of NH ₄ O. In this way, the acid can be completely removed.

After washing several times with water, the remaining benzladehyde solution of sodium bisulfite was removed by filtration. The crude product, which was washed again with water, was then dried at 100 ° C in vacuo and ground to a fine powder. Yield: 108 g. Melting point: 168 ° C.

Example 2

The procedure of Example 1 is repeated, except that the reactants are reacted with 56 cm ^{3 of} dry hydrochloric acid catalyst instead of sulfuric acid.

With the continuous introduction of hydrochloric acid gas, the reaction mixture becomes homogeneous, then begins to thicken gradually, eventually forming a soft gel block.

The precipitated gel phase was worked up as described in Example 1.

Yield: 98 g. Melting point: 169 ° C.

Example 3

Weigh 48 g of water into a 500 cm ³ flask fitted with a thermometer, a water bath and a mechanical stirrer and dissolve 144 g of sorbitol at 40 ° C. 160 ml of benzaldehyde and 160 ml of ethyl methyl ketone are then added to the syrup with vigorous stirring.

The two phases disappear after 60 ml of 98 wt% sulfuric acid are added dropwise with cooling, and the reaction mixture is homogenous. The temperature is maintained at 50 vol. Stirring is continued until

194,298 reaction mixture thickens. The material was then allowed to stand at room temperature for 24 hours. The precipitated gel phase was worked up as described in Example 1.

Yield: 140 g. Melting point: 175 C.

Example 4

The procedure of Example 1 was repeated, except that 160 ml of ethyl methyl ketone was used as the reactive solvent instead of acetone.

The reaction mixture was worked up as in Example 1.

Yield: 77 g. Mp 162 ° C.

Example 5

The procedure of Example 3 was repeated, except that 160 ml of acetone was used instead of 160 ml of ethyl methyl ketone. The reaction is carried out and the reaction mixture is worked up as described in Example 3.

Yield: 132 g. Melting point: 182 ° C.

Example 6

In the apparatus of Example 1, 183 g of sorbitol are dissolved in 65 ml of water at 40 ° C.

600 g of acetone and 53.06 g of benzaldehyde are then added with vigorous stirring. Two phases were observed, 60 ml cc. after the addition of sulfuric acid during cooling, it disappears and the reaction mixture is homogeneous.

In the following, all the procedures of Example 1 are followed.

Yield: 270 g. Melting point: 172 ° C.

Example 7

All proceed as in Example 6, but using 900 g of acetone instead of 600 g of acetone.

Yield: 350 g. Melting point: 174 ° C.

Example 8

All proceed as in Example 1, but using 40 ml of acetone instead of 146 ml of acetone.

Yield: 80 g. Melting point: 167 ° C.

Example 9

8 cm ^{3 of} butyl glycol, 18 cm ^{3 of} water, 70 cm ^{3 of} isopropyl alcohol are charged into a apparatus equipped with heating, a reflux condenser and a distillation apparatus, and then 22 g of vinylpyrrolidone (vinyl acetate copolymer monomer ratio 60-40% by weight) are added cold under vigorous stirring. %, molecular weight 30,000). After dissolution, 4.2 g of the gelling agent (Example 1) is added under cold stirring under reflux and vigorous stirring, the gelling agent is dissolved and then the solvent is distilled off. 60 cnr of solvent mixture was distilled off. .

To the resulting polymeric solution containing the gelling agent is added 2.0 cm ^{3 of} dimethylformamide, and the warm solution is then poured into a stick and allowed to cool.

The stick produced in this way is used to glue sheets of paper. Drying time of paper-paper surfaces at 20 ° C: 1.5-2.0 minutes.

The adhesive film is flexible, adheres well to the surface of the paper and does not break after several months.

The pin can be stored for one year in closed condition, without any changes, and retains its good properties for one year in use.

Example 10

The procedure of Example 9 is repeated, except that the copolymer of vinyl pinrolidone (dimethylaminoaminoethyl methacrylate) is used instead of vinyl acetate copolymer.

(The monomer weight ratio in the copolymer is 30:70 and the molecular weight is 90,000)

To the mixture was added 1% by weight of Brillantgrün dye based on dry matter and 0.1% by weight of pine scent to cover the odor of the organic solvent.

Example 11

Mixing apparatus was dissolved 7.1 g of poly (vinyl pirroKdon) -t (MW 30,000), 6 cm ³ of water with vigorous stirring and heating, and 4 cm ³ of butyl glycol 140 dissolved in 1.4 g of gellant (4th Example 1) is added.

After stirring for 10 minutes, when homogeneous, 10 g of talc are added, after mixing, poured into a warm mold and cooled. We get a transparent pin.

Example 12

All. The procedure of Example 1b is repeated, except that the same amount of N-methylvinylpimolidone polymer having a molecular weight of 25,000 is used in place of polyvinylpyrrolidone.

The stick retains its adhesive properties for 1 year.

Example 13

All. Example 4, except that 4 cm ^{3 of} dimethylformamide was used in place of butyl glycol.

Example 14

50 g of vinylpyrrolidone (vinyl acetate copolymer, molar weight: 30,000, monomer ratio 60-40% by weight) in a stirred gauze were dissolved at 100 ° C in a mixture of 10 cm ^{3 of} water and 17.9 cm ^{3 of} dimethylformamide, followed by 20 g of gelling agent. Example 1) is added and the suspension is stirred for 10 hours at 100 ° C until the system is homogeneous.

Dissolution of the gelling agent is facilitated by the addition of 1 cm ^{3 of} isopropanol. The warm solution was mixed with 1 g of methylene blue dye, 0.1 g of lily of the valley fragrance and 3 g of TiO 2 filler, and then poured into a tube. After cooling, a hard white stick is obtained which retains its good adhesive properties for 1 year.

Example 15

Example 9 is repeated, but as a gelling agent instead of a condensation product of sorbitol benzaldehyde acetone

194,298 monobenzal sorbitol is used.

The glue stick thus obtained is subjected to a storage test.

After 6 months, the prepared stick becomes sticky, soft, and unusable, while the product of the present invention can be stored for 1 year without damage.

The adhesive stick and control stick according to the invention were subjected to an adhesive test.

Two 30 x 60 mm writing papers were glued together using two different glue sticks.

Measure the average bond strength of 5 to 5 sample adhesives. The results are as follows:

Sample Bonding strength (cN) Example 9 pin 190 control 175

The comparative example shows that the product of the present invention, which can be stored for longer periods without damage, has the same or slightly better adhesive bond strength than the known product shown as a control.

Example 16

All proceed as in Example 11, but using 0.4 g of the gel form of Example 4.

Claims (2)

CLAIMS 1. A polymer-based composition for use as an adhesive stick, characterized in that a 1: (0.5-2.5): (0.5-150) molar ratio of sorbitol, benzaldehyde, acetone or ethylmethylketone is 40-70 °. C, washed and dried and then milled from sorbitol acetal isomeric mixture obtained by condensation at 0.5 ° C to 2 molar inorganic acid for 1 to 20 moles, 1 to 20% by weight, 15 to 50% by weight 10% to 70,000% by weight of an adhesive polymer preferably vinylpyrrolidone homo- or copolymer, methylcrylate copolymer, 5 to 60% by weight of an organic solvent in water, preferably an aliphatic mono- or polyalcohol, 0-50% by weight of organic solvent, a filler, preferably talc, titanium dioxide, and 0 to 1 weight percent of coloring and / or perfume. Composition according to claim 1, characterized in that the adhesive polymer comprises a vinylpyrrolidone / vinyl acetate copolymer.