CS247770B1 - Thixotropic contact adhesives based on aqueous dispersions of acrylic copolymers - Google Patents

Abstract

Thixotropic contact adhesives based on aqueous dispersions of acrylic copolymers • consist of 40 to 65% aqueous dispersion of butyl acrylate-ethyl acrylate-acrylic acid copolymer in mass ratios of 1:0.05 to 2:0.007 to 0.06, alkylene glycols with a number of carbon atoms of 2 to 15, 20 to 30% aqueous dispersion of ethyl acrylate-acrylic acid and/or methacrylic acid copolymer in mass ratios of 2.3 to 4:1, further pH-adjusting additives, possibly powdered inert fillers, water and other additives.

Description

The invention relates to dispersion thixotropic acrylic contact adhesives, particularly suitable for bonding PVC floor coverings, textile coverings, ceramic, glass and wood cladding, plastic films, thermal and acoustic insulation materials. They are characterized by a thixtropic chatacter and, after forming an adhesive bond, exhibit consistently high adhesion to the bonded substrates and retain high elasticity during aging of the bond,

The prior art dispersion adhesives which can be applied in the above-mentioned application examples are not sufficiently thixotropic, swell with water and thus lose adhesion properties, anchoring on the PVC surface is achieved by disruption of the surface by aggressive solvents (e.g. toluene (optionally containing health-damaging monomers, such as acrylonitrile). These dispersion adhesives are predominantly based on vinyl acetate, vinyl acetate-acrylate copolymers, vinyl acetate-ethylene, vinyl acetate-dibutyl maleate, and exhibit a lower peel resistance, especially for PVC joints,

These drawbacks overcome the thixotropic contact adhesives based on the aqueous dispersions of acrylic copolymers of the present invention. Its essence is that the adhesives consist of 100 wt. % of a 40 to 65% aqueous dispersion of butyl acrylate-ethyl acrylate-acrylic acid copolymer in wt. ratios of 1: 0.05 to 2: 0.007 to 0.06, 1 to 7 wt. % of alkylene glycols having a carbon number of 2 to 15.1 to 20 wt. % of a 20 to 30% aqueous dispersion of an ethyl acrylate-acrylic acid and / or methacrylic acid copolymer in a weight ratio of 2.3 to 4: 1, 0.1 to 10 wt. parts of pH adjusting additives and optionally up to 150 wt. parts of inert powder fillers, up to 50 wt. and up to 30 wt. parts of additives from the group consisting of resin products, consistency-adjusting additives, defoamers, antifungal additives, plasticizers, wetting and dispersing additives, coalescents, pigments and dyes.

The advantage of the present dispersion thixotropic acrylic contact adhesives is, in particular, that they contain a copolymer having a monomer weight composition which ensures high elasticity of the system over a wide range of application temperatures. The monomer composition chosen in this way causes high adhesion, in particular to the surfaces of the PVC-based substrates, particularly floor coverings. The high elasticity of the present adhesives makes it possible to compensate for dilatations of the substrate without the risk of loss of adhesion. Another advantage of the present adhesives resides in thixotropy, which ensures optimum processing and application conditions, especially in industrial applications. The thixotropic properties are achieved by a suitable combination of fillers and an acrylic copolymer having a dry weight of 20 to 30% by weight. Another advantage of the present adhesives is the possibility of high filling while maintaining sufficient adhesive properties.

Some of the properties of said adhesives can be improved or modified by the addition of organic and / or inorganic additives. Adhesion and cohesive properties, heat resistance and plasticizer resistance are adjusted by the addition of unmodified or modified natural and / or synthetic resins such as rosin, modified rosin-based, copal resin, shellac, balsam, phenol-formaldehyde resin, epoxy, epoxy-epoxy , polyester, coumarone and coumaronindene resins, polyterpene and terpene and terpene phenol resins, etc.

The resin products are preferably added in the form of dispersions containing surfactants. Resins having a temperature of up to 100 ° C, preferably in the range of 50 to 75 ° C, are added to increase the tack time. Among the internal powder fillers, limestone, kaolin, chalk, quartz, slate meal, blanc-fixe, feldspar dust, talc, precipitated calcium carbonate, colloidal silica and the like can be used.

Thickeners such as polyvinyl alcohol, carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, methylhydroxypropylcellulose, casein, starch and the like can be used to further adjust the consistency of the present adhesives.

Antifoams such as polyglycolamines, alkylaryl ether alcohols, ester alcohols, high molecular weight fatty alcohols, oxyethylene polypropylene glycols, and the like are added to prevent foaming of the adhesives, especially when dispersing fillers. To provide mold resistance, antifungal additives such as bis / triazinyl phenol, etc. are added.

Dispersing and wetting additives such as ethoxyalcohols, ethoxylated alkylphenol, sulfonated alcohols or oils, alkylarenepolyethylene glycol ether sulfate, alkylpolyethylene glycol ether sulfate and the like are added to facilitate dispersion and stabilization. Substances such as ammonia, primary, secondary, tertiary, etc. are added to adjust the pH. butylamine, morpholine, aminoalcohols such as monoethanolamine, diethanolamine, triethanolamine, alkali metal hydroxide solutions and the like.

Plasticizers such as dibutyl phthalate, tricresyl phosphate, diisoctyl phthalate, dicyclohexyl phthalate and the like are added to increase the initial tack and optionally plasticity. Coalescents such as ethoxyethylene glycol acetate, butoxyethylene glycol acetate, butoxyethylene glycol acetate, butoxyethylene glycol acetate, butoxyethylene glycol acetate are added. , hexylene glycol and the like. For clarification, the adhesive layer may be colored with inorganic pigments of the group of iron, zinc, titanium, chromium and the like and / or organic pigments, especially versal, phthalocyanine and the like.

The composition of the dispersion thixotropic acrylic adhesives is further exemplified. Parts and percentages given herein are by weight.

Example 1

Dispersion thixotropic adhesive suitable especially for bonding PVC floor coverings:

100 parts of a 45% aqueous dispersion of butyl acrylate-ethyl acrylate-acrylic acid copolymer in wt. ratio of 1: 0.05: 0.06 parts propylene glycol parts of a 23% aqueous dispersion of ethyl acrylate-methacrylic acid copolymer in wt. ratio

73:27 parts limestone grain 0.04 mm 8 parts ammonia

Example2

Dispersion thixotropic acrylic contact adhesive suitable especially for gluing wood cladding and insulating materials:

100 parts of a 63% aqueous dispersion of butyl acrylate-ethyl acrylate-acrylic acid copolymer in wt.

130

0.5 ratio 1: 1.9: 0.009 parts ethylene glycol parts 28% aqueous dispersion ethyl acrylate-acrylic acid copolymer in wt. 22 parts of the fodder parts of hydroxyethylcellulose part of the triethanolamine ratio

Example 3

Dispersion thixotropic acrylic contact adhesive suitable especially for gluing of PVC wallpaper and textile coverings:

100 parts of a 50% aqueous dispersion of butyl acrylate-ethyl acrylate-acrylic acid copolymer in wt. ratio of 1: 1: 0.02

3 ,. parts by weight of polyethylene glycol having a molecular weight of 300 parts by weight of a 26% aqueous dispersion of an ethyl acrylate-methacrylic acid copolymer in wt. ratio of 76:24 parts of kaolin parts of ammonia

Example 4

Strongly thixotropic acrylic contact adhesive with increased initial tack:

100 parts of a 55% aqueous dispersion of butyl acrylate-ethyl acrylate-acrylic acid copolymer in wt. ratio 1: 0.07: 0.04 parts propylene glycol parts 25% aqueous dispersion ethyl acrylate-acrylic acid copolymer in wt. ratio 75:25 parts diethanolamine parts limestone grain 0.04 mm 2 parts colloidal silica

0.5 parts of ethoxylated alkylphenol 0.4 parts of bistributyltin oxide parts of alkylphenolic resin with a softening point of 65 ° C

Example 5

Dispersion thixotropic acrylic contact adhesive suitable especially for gluing glass tiles:

100 parts of a 48% aqueous dispersion of butyl acrylate-ethyl acrylate-acrylic acid copolymer in wt. ratio of 1: 1.5: 0.018 parts of ethylene glycol parts of a 27% aqueous dispersion of ethyl acrylate-methacrylic acid copolymer in wt. ratio 73:27 ·

2.3 parts morpholine parts chalk parts blanc-fixe parts colloidal silica parts dibutyl phthalate parts iron oxide red parts butoxyethylene glycol parts

Claims (1)

Thixotropic contact adhesives based on aqueous dispersions of acrylic copolymers, additives and optionally fillers, characterized in that they consist of 100 wt. % of a 40 to 65% aqueous dispersion of butyl acrylate-ethyl acrylate-acrylic acid copolymer in wt. ratios of 1: 0.05 to 2: 0.007 to 0.06, 1 to 7 wt. parts of alkylene glycols having a carbon number of 2 to 15, 1 to 20 wt. % of a 20 to 30% aqueous dispersion of ethyl acrylate-acrylic acid and / or methacrylic acid copolymer in wt. a ratio of 2.3 to 4: 1, 0.1 to 10 wt. parts of pH adjusting additives and optionally up to 150 wt. parts of powdered inert fillers, up to 50 wt. parts of water and up to 30 wt. parts of additives from the group consisting of resin products, antifoams, antifungal additives, consistency adjusting additives, plasticizers, wetting and dispersing additives, coalescents, pigments and dyes.