CS240497B1 - High-gloss or medium-crystalline or polychlsulfate rubber footwear adhesive - Google Patents

Abstract

The invention relates to a shoe adhesive based on polychloroprene rubber, suitable in particular for gluing auxiliary joints in the production of footwear. It solves the problem of the optimal composition of the adhesive for gluing auxiliary joints. The essence of the adhesive according to the invention lies in the fact that it contains 10 to 20 parts by weight of highly crystalline polychloroprene rubber, with a viscosity of 5% rubber solution in toluene from 35 to 50 mPa. s, 5 to 10 parts by weight of medium crystalline polychloroprene rubber, with a viscosity of 5lO/o rubber solution in toluene from 10 to 25 mPa. s, 3 to 10 parts by weight of phenol formaldehyde condensate, 0.1 to 5 parts by weight of chlorinated natural rubber with a chlorine content of 70 parts by weight, 0.1 to 2 parts by weight of parts of zinc oxide, 0.1 to 2 parts by weight of magnesium oxide and 60 to 80 parts by weight of organic solvents.

Description

The present invention relates to a shoe adhesive based on polychleroprene rubber, suitable in particular for bonding auxiliary cords in the manufacture of footwear.

A wide variety of adhesives based on synthetic and natural rubber modified for the needs of a particular shoe application is currently known in shoe production. An adhesive comprising polychloroprene, butylphenol formaldehyde resin, zinc oxide, magnesium oxide, ethyl acetate and gasoline is known. To increase the resistance to acidic compositions, said adhesive is modified by the addition of an adduct of an epoxy resin with an aliphatic amine.

The adhesive is suitable for bonding plastics to metals. Another type of shoe adhesive consists of polychloroprene rubber, an adduct containing polyisocyanate, in the form of a butyl acrylate / afcrylonitrile copolymer, a glycerin ester, a filler and a solvent.

Furthermore, adhesives suitable for application in the manufacture of footwear are known, such as an adhesive comprising polychloroprene, zinc oxide, magnesium oxide, butylphenyl formaldehyde resin, rosin, thiuram and a solvent.

Phenylenediamine is added to the mixture to increase strength and thermal stability. Known is an adhesive composition comprising chloroprene rubber prepared by low temperature polymerization controlled by sulfur and thiuram, chloroprene rubber prepared by low temperature polymerization controlled by mercaptans, further comprising rosin, zinc oxide, isobutylformaldehyde resin and.

Cyclopentadiene or derivatives thereof are added to the adhesive to increase strength and water resistance. A good adhesive effect is characterized by a non-crosslinking polychloroprene adhesive comprising a chloroprene polymer or copolymer, a modified thermoreactive alkylphenol formaldehyde resin prepared by the action of an alkylphenol, for example cresol, aminophenol, or arylphenol, for example % copolymer by condensation with an aliphatic olefin or a diolefin containing from 4 to 5 carbon atoms in an amount of 90% by weight; with the corresponding amount of alkylphenol or arylphenol.

The resin may also form a complex with magnesium. The prepared adhesive composition does not separate into two layers, even after prolonged storage, and also in those cases where methyl ethyl ketone, cyclohexane and the like are used as solvents. The adhesive has good adhesive properties and is heat resistant.

A mixture of chloroprene polymer based adhesives prepared by emulsion polymerization of chloroprene or a mixture of chloroprene and copolymer, in the presence of an aliphatic substituted benzoic acid salt or in the presence of a nonionic surfactant of the single or compound polyoxiethylene ester type is known.

In shoe production, in many cases, replacements for polyurethane glue are used with an adhesive consisting of 10% by weight. parts of highly crystalline polychloroprene rubber, which may be up to 50 wt. % replaced by medium crystalline polychloroprene rubber, 8 to 10 wt. 0.1 parts by weight of acid acceptors and vulcanizing agents in the form of zinc oxide and magnesium oxide; parts by weight of an alpha-methylstyrene-based resin polymer; parts by weight of an alkylphenol formaldehyde-based reactive bitumen condensate, with the addition of di-, tri-, or tetraisocyanate-based crosslinking agents, in 300 to 500 wt. parts of a mixture of organic solvents, in particular toluene, ethyl acetate, gasoline, ketone or cyclohexanone.

Said glue forms strong mainly the joints between the sole and the upper. However, the adhesive is economically disadvantageous to be used for an adhesive bonding application; since it is expensive and made from a scarce raw material, especially alpha-methylstyrene-based resins.

A disadvantage of these adhesives is, in part, that they have a high viscosity and relatively low bond strength values for a given dry matter of rubbers. During handling there is a flow of viscous adhesive and uneven application on the materials to be bonded.

The above-mentioned disadvantages are overcome by the adhesive according to the invention, which comprises 10 to 20 wt. parts of a high polycrystalline polychloroprene rubber having a viscosity of a 5% solution of rubber in toluene from 36 to 50 mPa · s. 5 to 10 wt. parts of a mid-crystalline polychloroprene rubber having a viscosity of a 5% rubber solution in toluene of 10 to 25 mPa. 3 to 10 wt. parts by weight of phenol-formaldehyde condensate, 0.1 to 5 wt. parts by weight of chlorinated natural rubber with a chlorine content of 70 wt. 0.1 to 2 wt. 0.1 parts by weight of zinc oxide; % of magnesium oxide and 60 to 80 wt. parts of organic solvents.

The technical effect of the adhesive according to the invention is that by combining medium and high crystalline polychloroprene rubber, inter- and intramolecular polymer structures are formed to form a new structure with increased cohesive strength of the dried adhesive bond.

In solution, the formation of a new structure results in a lower viscosity with the same dry matter content of the rubber. The initial and final strength of the auxiliary joints will be increased. Reducing the viscosity increases the diffusion of the adhesive into the materials to be bonded, allowing good spreadability and handling.

The adhesive according to the invention is illustrated by the following examples. All amounts of the components are given in parts by weight.

Example 1 is a reference.

EXAMPLE

22 wt. d. of a highly crystalline polychloroprene rubber having a viscosity of 5% solution of rubber in toluene of 40 mPa. s, 6 wt. d. phenol-formaldehyde condensate, 2 wt. d. chlorinated natural rubber, 1 wt. d. % zinc oxide, 1 wt. d. of magnesium oxide, 24 wt. d. toluene, 12 wt. d. ethyl acetate and the mixture was thoroughly homogenized and then diluted with 30 wt. d. petrol.

An adhesive having a viscosity of 45 mPa was prepared. . and the initial bond strength of the rubber vulcanizate to leather was 35 N / 25 mm.

Example 2

Into the homogenizer, 12 wt. d. a high-crystalline polychloroprene rubber having a viscosity of a 5% solution of rubber in toluene of 35 mPa.s. s, 10 wt. d. An intermediate crystalline polychloroiprene rubber having a viscosity of a 5% solution of rubber in toluene of 15 mPa.s. s, 6 wt. d. phenol-formaldehyde condensate, 2 wt. d. chlorinated natural rubber, 1 wt. d. % zinc oxide, 1 wt. d. of magnesium oxide, 24 wt. d. toluene, 12 wt. d. ethyl acetate. The mixture is perfectly homogenized and then diluted to 34 wt. d. petrol. An adhesive having a viscosity of 3000 mPa.s was prepared. and the initial bond strength of the rubber vulcanizate to leather was 45 N / 25 mm.

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EXAMPLE 1 a d 3

17 masses were gradually fed into the homogenizer. d. of highly crystalline polychloroprene. of a rubber having a viscosity of 5 ¹⁰ / a solution of rubber in toluene of 45 mPa.s. s, 5 wt. d. An intermediate crystalline polychloroprene rubber having a viscosity of a 5% solution of rubber in toluene of 20 mPa.s. s, 8 wt. d. phenol-formaldehyde condensate, 1 wt. d. of chlorinated natural rubber, 0.1 wt. d. zinc oxide and 1.5 wt., d. of magnesium oxide, 20 wt. d. toluene, 10 wt. d. ethyl acetate. The mixture is homogenized and diluted to 30 wt. d. and 10 wt. d. acetone. An adhesive having a viscosity of 2800 mPa was prepared. the initial bond strength of the rubber vulcanizate to leather was 40 N / 25 · mm.

Example 4

Into the homogenizer, 15 wt. d. of a highly crystalline polychloroprene rubber having a viscosity of a 5% rubber solution in toluene of 35 mPa.s. s, 7 wt. d. Medium crystalline polychloroprene rubber, having a viscosity of a 5% solution of rubber in toluene 25 mPa. s, 4 wt. d. phenol-formaldehyde condensate, 3 wt. d. chlorinated natural rubber, 1.5 wt. d. % zinc oxide, 0.1 wt. d. of magnesium oxide, 25 wt. d. toluene and 10 wt. d. ethyl acetate. The mixture is perfectly homogenized and diluted to 40 wt. parts of gasoline. An adhesive having a viscosity of 2 750 mPa was prepared. and the initial bond strength of the rubber vulcanizate to leather was 39 N / 25 mm.

Claims (4)

SUBJECT Shoe adhesive based on high-crystalline and medium-crystalline polychloroprene rubber, phenol-formaldehyde condensate, zinc oxide, magnesium oxide, chlorinated natural rubber and organic solvents, suitable in particular for bonding auxiliary joints in footwear production, characterized in that it contains 10-20 parts by weight rubber, having a viscosity of 5% / a solution of rubber in toluene of 35 to 50 mPa. 5 to 10% by weight of the inventive parts of a medium crystalline polychloroprene rubber having a viscosity of a 5% solution of rubber in toluene of from 10 to 25 mPa.s. s, 3 to 10 parts by weight of phenol-formaldehyde condensate, 0.1 to 5 parts by weight of chlorinated natural rubber with a chlorine content of 70 parts by weight, 0.1 to 2 parts by weight of zinc oxide, 0.1 to 2 parts by weight of magnesium oxide and 60 up to 80 parts by weight of organic solvents.