JPS5928235B2 - adhesive composition - Google Patents

Description

[Detailed description of the invention] This invention relates to adhesive compositions containing gelling agents.

More particularly, this invention relates to self-supporting adhesive compositions and gelled liquid adhesives, the latter having little or no tendency to run or trail. In the composition of this invention, the gelling agent is a monoamide salt of terephthalic acid. Adhesive compositions are widely used in factories, homes and offices.

Due to their unique properties, they can be unpleasant and difficult to handle when used improperly. Particularly for home or office use, therefore, manufacturers of adhesives use adhesives to make their handling and use as simple as possible and to minimize the risk of accidental spillage or contact with surfaces other than the working surface. I have been trying to create a composition of The most widely used type of adhesive composition in homes and offices is adhesive polymer solutions or dispersions in volatile liquid vehicles.

Unfortunately, such compositions are liquid and therefore the most difficult to control in use. They tend to run when applied to sloped surfaces. That is, the applicator (
Bottles (usually with squeeze tubes or flexible dispensing nozzles) tend to pull strings or tails when removed from the work surface and may be left uncovered on the work surface or otherwise inadvertently left unattended. There is a tendency for such applicators to run off if left in place. Most of the aforementioned difficulties arise from the fact that the composition is a free-flowing liquid, and attempts have been made to overcome these problems by thickening or gelling the liquid to the point where it no longer flows freely. It has been done. However, the adhesion of polymers depends very precisely on the adhesion between the two surfaces to be joined and the intermediate polymer film. Excess material present in the film tends to have an anti-adhesive effect. Therefore, attempts to add gelling agents to simple basic systems of polymer and volatile solvent are always undertaken with caution and careful evaluation of the effect of the proposed gelling agent on the adhesive properties of the composition. Many gelling agents used in technical fields other than the adhesive field are unsuitable. This may be because, for example, they are inherently incompatible with the adhesive polymer or have to be used in very high concentrations, which impairs the adhesive properties.
This is because it has an adverse effect on the drying time or does not gel the solution system. Despite this basic problem in choosing the right gelling agent, it is possible to rub it onto a work surface and leave behind an effective adhesive film in the form of an adhesive stick or crayon. The composition has been proposed.

These proposed adhesive stakes are either waxy solid-based dispersions of adhesive polymers or gelled solutions or dispersions of adhesives in common liquid vehicles. In the latter case, usually at least 10%, more usually at least 15% gelling agent was required to achieve the desired stick consistency. In addition, previously proposed gelling agents, particularly fatty acid salts, have a small but significant anti-adhesion effect. This invention is based on the discovery that certain terephthalic acids can be used in relatively small amounts to gel solutions or dispersions of adhesive polymers without significant anti-adhesion effects.

According to the invention, therefore, at least one adhesive polymer, at least one non-toxic, volatile solvent or liquid dispersant for the adhesive polymer and a tendency for the solution or dispersion to flow under the influence of gravity. and a gelling agent in an amount sufficient to reduce the amount of the gelling agent represented by formula (1): An adhesive composition is provided, which is a salt of a compound represented by (representing a hydrogen group).

Preferably R is a hydrogen atom and R1 is a C4-16 alkyl group.

Suitable salts of the compound of formula (1) include alkali metal salts,
Includes alkaline earth metal salts, ammonium salts and substituted ammonium salts.

Particularly suitable salts include sodium, potassium and ammonium salts, with sodium salts being preferred. formula(
The compound 1) was published in Industrial and Engineering Chemistry Volume 49, No. 10, 1957.
October, pp. 1691-1694 and N.L.
Jiichi Spokesman, Volume 20, No. 11, 1
February 957, pages 10-15, their properties as gelling agents are mentioned. Nothing in these publications suggests the use of these compounds in adhesive compositions. The adhesive polymers in the compositions of this invention may be selected from those commonly used in the manufacture of adhesive stakes and liquid adhesives.

Suitable adhesive polymers include polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyvinylpyrrolidone, polyurethane, polyacrylic acid or polymethacrylic acid or their esters, polyacrylamide, methylcellulose, ethoxylated starch derivatives, and the like. The type of liquid base in the compositions of this invention depends in part on the adhesive polymer used and in part on whether the composition is a solid gelled stake or a gelled but flowable one. It will depend on whether it is a liquid or not.

In most cases, the liquid base will be a mixture of solvents selected to provide the required drying rate and the required solubility or dispersion properties. Water will normally be the major component of the stake composition. And mixtures of water and lower alcohols such as methanol, ethanol and glycerin are sometimes useful liquid bases for stocks. The liquid base for more fluid compositions will usually be a mixture of solvents of intermediate polarity. Solvents traditionally used in sticks and liquid adhesives include water, lower alcohols, and low molecular weight esters and ketones. Mixtures of two or more of the following are used: water, glycerin, methanol, ethanol, isopropanol,
Ethylene glycol, methyl acetate, ethyl acetate, butyl acetate, dibutyl phthalate, cyclohexanone, acetone, methyl ethyl ketone, and methyl isobutyl ketone. The choice of solvent will also depend on the gelling agent used.

Long-chain compounds of formula (1) (where R1 and/or R have 10 or more carbon atoms) tend to be relatively insoluble in water, so if a very hard stay is desired, non-aqueous compounds may be used. A solvent system may be required. Short chain compounds (
(R1 and/or R having 3 or less carbon atoms) are highly soluble in water and may be uneconomical in aqueous solvent systems. In some cases, small amounts of emulsifying or dispersing agents may be necessary to achieve a homogeneous mixture.

In general, the compositions of this invention contain 5-50% (by weight), usually 10-40% and often 15-30%.
% adhesive polymer. The concentration of gelling agent will be selected according to the degree of gelling required.

Usually a small amount, for example 0.1 to 2%, will be sufficient to gel to the point where the tendency of the liquid adhesive to run or trail is substantially eliminated. For the manufacture of adhesive stakes, a large mesh size, e.g. 2.5 to 10
%, often as much as 10-25%. We have found that in compositions of the invention containing large amounts of water, the inclusion of ionic compounds is advantageous as it increases the stability of the composition.

Although the mechanism is not completely understood, it is believed that ionic compounds create a type of salting-out effect that increases the gelation temperature. Suitable ionic compounds for inclusion in such compositions include sodium chloride, potassium chloride, ammonium chloride, sodium sulfate and other stable water-soluble ionic salts.

We believe it is beneficial to include sodium chloride in the self-supporting adhesive composition.

Usually such ionic compounds make up 2-15% of the final composition.
%, more typically 5-10%, preferably about 7-8%
Make it exist.

The self-supporting adhesive compositions of this invention can be prepared by mixing the ingredients and heating (usually 60-90°C) during or after mixing.

Optionally, or more conveniently, the free acid of formula (1) above can be made to act as a gelling agent by adding thereto a base such as sodium hydroxide, potassium hydroxide or ammonium hydroxide during blending. can be converted into the desired salt. Once a uniform melt is obtained,
Then leave it to cool. It is best to avoid substantial agitation of the mixture during cooling. Stakes can be made by cooling the mixture in a mold. On the other hand, if an ionic compound is to be included in the composition if desired, this can be added to the mixture already formed by mixing and heating the other components of the composition. . Often, the addition of this ionic compound changes the gel point of the composition and may aid in solidification. Once formed, the adhesive stake can be included in a conventional adhesive applicator, such as a rotary extruder lipstick type dispenser. On the other hand, the homogeneous melt may be added to an applicator or the like which can be used as a mold and in which the melt solidifies. For other adhesive compositions, the heated mixture may be filled into a collapsible tube and allowed to cool itself. Next, the present invention will be explained with reference to Examples.

Free standing example by pouring the mixture into a mold and cooling it
An adhesive of the following composition was prepared by blending the two warmed ingredients.

The mixture was filled into a collapsible aluminum tube and cooled.

An extrudable jelly-like composition was obtained, which was an effective adhesive with little tendency to run or trail. Example 3 An adhesive was manufactured according to the following formula.

The above ingredients were blended while heating to a temperature of about 80°C.

Although the free acid was not very soluble in water, it gradually reacted with sodium hydroxide to form a soluble sodium salt and a homogeneous mixture was obtained. The mixture was poured into molds and allowed to cool, resulting in self-adhesive stakes. Example 4 Sodium hydroxide (30%) 4.5%.

The 48.5% step is similar to Example 3.

Example 5 n-octyl terephthalic acid amide 5% Sodium hydroxide (30%) 5% 1,2-propylene glycol 7% Glycerin 10% Polyvinyl alcohol (partially saponified to 25%)
Water 48% The process is the same as in Example 3.

Example 6 n-decyl terephthalic acid amide 3% 1,2-propylene glycol 17% Polyvinylpyrrolidone 25% Sodium hydroxide (30%) 5% water 50% The steps are the same as in Example 3.

Claims (1)

[Scope of Claims] 1. at least one adhesive polymer, at least one non-toxic and volatile solvent or liquid dispersant for the adhesive polymer, and at least one non-toxic and volatile solvent or liquid dispersion agent for the adhesive polymer and for the solution or dispersion thereof which flows under the influence of gravity. a gelling agent in an amount sufficient to reduce the tendency, where the gelling agent has the formula (I): ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) (In the formula, R represents a hydrogen atom or an alkyl group of C_1 to_1_8,
An adhesive composition characterized in that it is a salt of a compound represented by (_1 represents a hydrocarbon group of C_1 to_1_8). 2 The gelling agent is of formula (I), R is a hydrogen atom, and R_
The adhesive composition according to claim 1, which is a salt of a compound in which 1 is a C_4 to_1_6 alkyl group. 3 the gelling agent is an alkali metal salt of the compound of formula (I);
3. The adhesive composition according to claim 1 or 2, which is an alkaline earth metal salt, an ammonium salt, or a substituted ammonium salt. 4. Claims in which the adhesive polymer is selected from polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyvinylpyrrolidone, polyurethane, polyacrylic acid or polymethacrylic acid or their esters, polyacrylamide, methylcellulose and ethoxylated starch derivatives The adhesive composition according to any one of the ranges 1 to 3. 5. The adhesive composition according to any one of claims 1 to 4, comprising 5 to 50% by weight of adhesive polymer. 6. Adhesive composition according to claim 5, in which from 10 to 40% by weight of adhesive polymer is present. 7. Adhesive composition according to claim 5, in which from 15 to 30% by weight of adhesive polymer is present. 8. The adhesive composition according to any one of claims 1 to 7, wherein the gelling agent is present in an amount of 0.1 to 2% by weight. 9. The adhesive composition according to any one of claims 1 to 7, wherein the gelling agent is present in an amount of 2.5 to 10% by weight. 10. The adhesive composition according to any one of claims 1 to 7, wherein the gelling agent is present in an amount of 10 to 25% by weight. 11. The adhesive composition according to any one of claims 1 to 10, which contains a water-soluble ionic salt. 12. The adhesive composition according to claim 11, wherein the ionic salt is sodium chloride, potassium chloride, ammonium chloride or sodium sulfate. 13. The adhesive composition according to claim 11 or 12, wherein the ionic salt is present in an amount of 2 to 15% by weight. 14. The adhesive composition according to claim 13, wherein the ionic salt is present in an amount of 5 to 10% by weight. 15. The adhesive composition according to claim 14, wherein the ionic salt is present in an amount of 7 to 8% by weight.