CS244989B1 - A method of producing a shoe melt adhesive - Google Patents

Abstract

The invention relates to a method of producing footwear hot melt adhesive. It solves the problem of the method of polymerization of fatty acid dimers with the aim of obtaining an adhesive with a short open time. The essence of the invention is that the polymerization takes place in three stages, where in the first stage the reaction temperature is not higher than the boiling point of the amine with the lowest numerical value by more than 20 °C at a pressure of up to 0.1 MPa for 1 to 3 hours, in the second stage the reaction temperature is increased to 160 to 170 °C at a pressure of up to 0.25 MPa for 3 to 5 hours, in the third stage the reaction takes place at a temperature of 200 to 220 °C at a pressure of up to 0.5 MPa for 1 to 5 hours and then the water of reaction is removed.

Description

The present invention relates to a process for producing a shoe melt adhesive by fatty acid polymerization containing 70 to 95 wt. % of fatty acid dimers, up to 30 wt. parts of fatty acid trimers per 100 wt. parts of a mixture of fatty acids in the presence of a dicarboxylic acid having a carbon number of 2 to 8 and monocarboxylic aliphatic acids having a terminated polymeric chain having a carbon number of 3 to 20.

In the shoemaking industry, in the manufacture of lined stretch insoles, in the shoe sides, in the manufacture of thermo-binders, hot-melt adhesives are used, which are characterized by a sharp melting point. The properties of adhesives are influenced by the way they are produced. A process for the production of a hot melt adhesive consisting of fatty acid dimers having a dimer content of 80 wt. d. per 100 wt. d. fatty acids, further comprising dibasic acids and 1,2-diaminoethane. The reaction is carried out at 150 to 300 ^° C for 5 hours, followed by distilling off the water. Also known is a hot melt adhesive prepared from dimers of fatty acids, dibasic acids, ethylenediamine at an initiation temperature of not more than 160 ° C for at least 1 hour and subsequent condensing at 175-225 ° C to give a product which is soluble in butyl alcohol. A hotmelt adhesive is known which comprises a polyamide resin obtained by polycondensation of an aliphatic diamine with a mixture of unsaturated monomers and polymers of fatty acid and aliphatic dicarboxylic acid and / or ester. The content of natural or synthetic wax is also preferred. Furthermore, a hot-melt adhesive is known which is prepared by polycondensation of diamines with polymeric fatty acids or their esters, wherein the acid dimer content is 90 to 100% by weight. parts. The polycondensation is carried out at a temperature of 180 to 250 ° C. The disadvantages of the adhesives produced by the above method are their longer setting time and lower bond strength of the glued materials.

The above-mentioned disadvantages are overcome by the process according to the invention, which consists in that the polymerization is carried out in three stages, in which in the first stage the reaction temperature is not higher than the boiling point of the amine with the numerical value below 0.1 MPa for 1 to 3 hours, in the second step the reaction temperature is raised to 160 to 170 ° C under a pressure of up to 0.25 MPa for 3 to 5 hours, in the third step the reaction is carried out at 200 to 220 ° C at a pressure up to 0.5 MPa for 3-5 hours, then remove the water of reaction.

The technical effect of the process according to the invention is to provide a hot-melt adhesive which has an open time of at most 10 seconds, during which the final bond strength of the materials to be bonded is reached. This shortens the bonding time.

The adhesive manufacturing process is illustrated by the following examples, wherein the amounts of the components are given in parts by weight.

Example 1

A mixture containing 190 wt. d. % palmitic acid dimer and 10 wt. d. palmitic acid, 2 wt. d. adipic acid, 26 wt. d, ethylenediamine and 3 wt. parts of oleic acid. The mixture was polymerized in three stages. In the first stage, it was heated to 110 ° C at a pressure of up to 1 bar for 2 hours. In the second step, the temperature was raised to 170 ^° C at a pressure of up to 50 psi for 5 hours. In the third step, the temperature was raised to 200 ° C at a pressure of up to 0.5 MPa for 4 hours. The reaction water was then removed by means of a vacuum pump. The adhesive thus prepared was discharged and granulated. The adhesive · was brittle with the following physico-mechanical properties:

milling temperature acid number amine number viscosity at 165 ° C

110 ° C max. 10 max. 7 2,500 mPa. with

Example 2

A mixture containing 160 wt. d. oleic acid dimer, 30 wt. d. oleic acid trimer and 10 wt. d. oleic acid, 10 wt. d. aselaic acid, 28 wt. parts of ethylenediamine and 4 wt. d. palmitic acid. The mixture was polymerized in three stages. In the first step, it was heated to 120 ° C at a pressure of up to 1 bar for 1 hour. In the second stage, the temperature was raised to 160 ° C at a pressure of up to 50 psi for 5 hours. In the third stage, the temperature was raised to 220 ° C under a pressure of up to 0.5 MPa for 3 hours. The reaction water was then removed by means of a vacuum pump. The adhesive thus prepared was drained and granulated. The adhesive was brittle with the following physico-mechanical properties:

milling temperature acid number amine number viscosity at 210 ° C

170 ^C C max. 10 max. 7 3000 mPa. 3

Example 3

A mixture containing 160 wt. d. stearic acid and 40 wt. d. stearic acid trimer, 23 wt. d. sebacic acid, 26 wt. d. ethylenediamine, 13 wt. d. hexamethylenediamine and 8 wt. d. stearic acid. The mixture was polymerized in three stages. In the first stage, it was heated to 115 ° C at a pressure of up to 1 bar for 1.5 hours.

In the second stage, the temperature was raised to 165 ° C at a pressure of up to 0.25 MPa for 4 hours. In the third stage, the temperature was raised to 210 ° C at a pressure of up to 0.5 MPa for 3.5 hours. The reaction water was then removed using a vacuum pump. The adhesive thus prepared was drained and granulated. The adhesive was elastic with the following physico-mechanical properties:

softening point acid number amine Viscosity number at 200 ° C

170 ° C max. 10 max. 7 2,500 mPa. with

Claims (1)

A process for the manufacture of a shoe-type hot melt adhesive by fatty acid polymerization containing 70 to 95 wt. % of fatty acid dimers, up to 30 wt. parts of fatty acid trimers per 100 wt. parts of a mixture of fatty acids in the presence of a dicarboxylic acid having a carbon number of 2 to 8 and monocarboxylic aliphatic acids having a terminated polymer chain having a carbon number of 3 to 20, characterized in that the polymerization risk is carried out in three stages the reaction is not higher than the boiling point of the lowest numbered amine by more than 20 ° C at a pressure of up to 0.1 MPa for 1 to 3 hours, in the second step the reaction temperature is increased to 160-170 ° C at a pressure of 0 25 MPa for 3-5 hours, in the third step, the reaction is carried out at a temperature of 200-220 ° C at a pressure of up to 0.5 MPa for 1-5 hours and then the reaction water is removed.