CS253128B1 - Adhesive composition based on aqueous dispersions - Google Patents

Abstract

The invention relates to adhesive compositions capable of bonding a wide range of materials including polyethylene and polypropylene. They consist of a 40 to 65% aqueous dispersion of an acrylic copolymer prepared by emulsion copolymerization of 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, acrylic acid, methacrylamide, and optionally hydroxyethyl methacrylate. This copolymer may optionally be modified with dodecyl mercaptan. Mixtures of the dispersion of the acrylic copolymer mentioned above with a dispersion of a copolymer of acrylic and vinyl monomers, from the group including vinyl acetate, styrene, methyl methacrylate, methacrylamide and glycidyl methacrylate, in a weight ratio of 1:2 to 10 may also be used. Furthermore, optionally, the composition contains additives from the group including fillers, modified or unmodified natural and/or synthetic resins, wetting and dispersing additives, defoamers, thickeners, coalescing agents, antifungal additives, pigments and dyes.

Description

The invention relates to adhesive compositions based on aqueous dispersions, optionally of mercaptan-modified acrylic copolymers or mixtures thereof with aqueous dispersions of copolymers of acrylic and vinyl monomers and optionally containing additives.

Previously known compositions based on aqueous dispersions use acrylic or methacrylic copolymers as binders, such as methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate and acrylic acid in combinations with styrene, vinyl acetate, acrylonitrile, etc. Compositions prepared from these dispersions have limited applicability only for some applications, have low adhesion to plastics, lower heat resistance, lose adhesive properties in a humid environment, or are made from monomers that are harmful to health, such as acrylonitrile.

The above-mentioned shortcomings are eliminated by the present invention, the subject of which are adhesive compositions based on aqueous dispersions, optionally mercaptans of modified acrylic copolymers or their mixtures with aqueous dispersions of copolymers of acrylic and vinyl monomers and optionally containing additives.

The essence of this invention lies in the fact that the composition consists of a 40 to 65% aqueous dispersion of an acrylic copolymer prepared by emulsion copolymerization of 25 to 60 parts by weight of 2-ethylhexyl acrylate, 10 to 60 parts by weight of butyl acrylate, 5 to 40 parts by weight of ethyl acrylate, 2 to 7 parts by weight of acrylic acid and 0.5 to 5 parts by weight of methacrylamide, optionally 0.5 to 8 parts by weight of hydroxyethyl acrylate and optionally modified with 0.01 to 1 part by weight of dodecyl mercaptan or a mixture of a dispersion of the said acrylic copolymer with a dispersion of copolymers of acrylic and vinyl monomers, especially from the group comprising vinyl acetate, styrene, methyl methacrylate, methacrylamide and glycidyl methacrylate, in a weight ratio of 1:2 to 10 and optionally up to 400 parts by weight of parts of additives from the group including fillers, modified or unmodified natural and/or synthetic resins, wetting and dispersing agents, defoamers, thickeners, coalescents, antifungal additives, pigments and dyes.

The advantage of the adhesive compositions according to the present invention is the ability to bond a wide range of materials, including polyethylene and polypropylene. This ability is given by the low glass transition value of the basic copolymers and, in addition, by the partial crosslinking of the functional groups contained in the system. This partial crosslinking is both physical in the case of compositions without hydroxyethyl methacrylate and chemical in the case of compositions containing hydroxyethyl methacrylate. In this way, heat resistances of up to 150 °C are achieved while maintaining resistance to low sub-zero temperatures. Another significant advantage is the elastomeric behavior of the compositions, i.e. plastic flow occurs under load only at higher application temperatures.

Filled systems are preferably applied as self-adhesive, i.e. those that form a permanently adhesive film after drying (especially suitable for laminations of polyethylene and polypropylene).

Filled systems are used for bonding absorbent materials. As fillers, chalk, kaolin, mining stone, feldspar, limestone, slate flour, colloidal silicon dioxide, talc, mineral fibers, etc. can be used. Due to the high filling capacity of the presented acrylic copolymers, it is possible to prepare flexible sealants from them, e.g. for leveling, jointing, etc. Less filled systems are preferably used for bonding tiles.

The present copolymers are viscosity-dependent on pH change, with increasing pH value the viscosity increases. To adjust it, ammonia, solutions of alkali hydroxides or preferably primary, secondary and tertiary amines, e.g. butylamine, morpholine and amino alcohols, such as monoethanolamine, diethanolamine, triethanolamine etc. can be used.

The adhesive properties can be adjusted by adding unmodified or modified natural and/or synthetic resins, such as rosin, modified rosin-based resins, copal resins, shellacs, balsams, phenol-formaldehyde resins, epoxy, epoxyester, polyester, coumarone and coumaroneindene, polyterpene and terpenephenolic resins, etc. Resin products are preferably added in the form of dispersions containing surfactants.

To facilitate dispersion in multi-filled compositions and for stabilization, dispersing and wetting additives such as ethoxy alcohols, ethoxylated alkylphenol, sulfonated alcohols or oils, etc. are added.

To thicken the compositions, thickeners such as polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, starch, etc. can be used.

To reduce the foaming of compositions, especially during production, defoamers are added, such as ester alcohols, high molecular weight fatty alcohols, polyglycolamides, etc.

To ensure resistance to mold, antifungal additives such as chlorinated phenols, bis(tributyltin) oxide, triazines, etc. are added.

Ethoxyethylene glycol acetate, hexylene glycol, butoxyethylene glycol, 1,4-butanediol, etc. can be used as coalescents.

The compositions mentioned are suitable for bonding foil and board materials based on plasticized polyvinyl chloride, polyethylene, polypropylene, etc., to absorbent and non-absorbent substrates, for bonding floor coverings, ceramic, glass and wooden tiles, thermal and sound insulating materials, as well as in packaging technology and printing, upholstery and footwear, and in combinations with hard dispersions for bonding wood, building tiles, etc. Due to the nature of the copolymers, the aforementioned compositions can be used as sealants or protective coatings with the ability to withstand weather conditions and expansion.

The subject matter of the invention is further illustrated by the following exemplary embodiments:

Example

The composition suitable for adhesive tapes, for lamination of polyethylene and polypropylene on paper and cardboard consists of 55% aqueous copolymer prepared by emulsion copolymerization.

25 mass parts 2-ethylhexyl|acrylate 60 mass parts butyl acrylate 8 mass parts ethyl acrylate 2 mass parts acrylic acids 5 mass parts methacrylamide and of 2 mass parts ammonia 0.02 mass parts polyglycolamine. P h o r k harmony 2

Adhesive composition for bonding floor coverings contains 50 parts by weight of 40% copolymers prepared by emulsion copolymerization

60 mass parts 2-ethylhexyl acrylate 20 mass parts butyl acrylate 12 mass parts ethyl acrylate 7 mass parts acrylic acids 1 mass work methacrylate,

modified

0.02 mass work dodecyl mercaptan and and 23 mass parts VJM limestone 20 mass parts chalk 3 mass parts morpholine 3.6 mass parts coumarone resins 0.4 mass parts bis(tributyltin)oxide

Example 3

Adhesive composition for bonding thermal and sound insulating materials in the automotive industry, usable in the temperature range of -40 to +150 °C, contains a copolymer prepared by emulsion copolymerization

40 wt. parts of 2-ethylhexyl acrylate 30 wt. 20 wt. parts butyl acrylate parts ethyl acrylate 5 wt. parts of acrylic acid 2 wt. parts of methacrylamide 3 wt. parts of hydroxyethyl methacrylate 3 wt. parts 26% ammonia

Example 4

The adhesive composition for gluing wood consists of 10 parts by weight of a 50% aqueous copolymer prepared by emulsion copolymerization.

25 wt. parts of 2-ethylhexyl acrylate 40 wt. parts of butyl acrylate 20 wt. parts of ethyl acrylate 6 wt. parts of acrylic acid 4 wt. parts of methacrylamide 5 wt. parts of hydroxyethyl methacrylate and from 75 wt. parts of copolymer prepared by emulsion copolymerization 50 wt. parts of methyl methacrylate 44 wt. parts of butyl acrylate 4 wt. parts of methacrylamide 2 wt. parts of acrylic acid and from 10 wt. pieces of feldspar dust 5 wt. parts of colloidal silicon dioxide

Example5

Adhesive composition for bonding building cladding consists of 10 parts by weight of 55% copolymer prepared by emulsion copolymerization

40 wt. parts of 2-ethylhexyl acrylate 22 wt. parts of butyl acrylate 30 wt. 3.5 wt. parts ethyl acrylate part acrylic acid 3 wt. parts of methacrylamide

0.5 parts by weight of hydroxyethyl methacrylate modified by parts by weight of dodecyl mercaptan. and from 30 parts by weight of a 50% copolymer containing parts by weight of vinyl acetate 10 parts by weight of butyl acrylate the composition further comprises

49.5 wt. 5 wt. parts limestone VJM parts modified rosin 5 wt. parts of colloidal silicon dioxide 0.5 wt. parts of bis(tributyloin)oxide

Example 6

Adhesive composition having the character of an adhesive sealant usable for jointing consists of 25 parts by weight of a 65% copolymer prepared by emulsion copolymerization

26 mass parts 2-ethylhexyl acrylate 26 mass parts butyl acrylate 40 mass parts ethyl acrylate 2 mass parts acrylic acids 3 mass parts methacrylamide 3 mass parts hydroxyethyl methacrylate 75 mass parts mining workers 15 mass parts limestone 3 mass parts colloidal silicon dioxide 5 mass parts dibutyl phthalate 2 mass parts triethanolamine to harmony 7

Adhesive composition suitable as a protective coating for roofs consists of 50 parts by weight of 60% copolymer

prepared emulsion copolymerization 30 wt. , parts 2-ethylhexyl acrylate 24 wt. . parts butyl acrylate 40 wt. , parts ethyl acrylate 2 wt. , parts acrylic acid 4 wt. , parts of methacrylamide and from 45 wt. pieces of feldspar 2.5 wt. , parts colloidal silicon dioxide 2 wt. , parts propylene glycol 0.3 wt. parts of ester alcohol 0.2 wt. parts of ethoxylated alkylphenol.

SUBJECT OF THE INVENTION

Claims (2)

SUBJECT OF THE INVENTION Adhesive composition based on aqueous dispersions or mercaptans of modified acrylic copolymers or mixtures thereof with aqueous dispersions of copolymers of acrylic and vinyl monomers, optionally containing additives, characterized in that it consists of 40 to 65% of an aqueous dispersion of acrylic copolymer prepared by emulsion copolymerization of 25 to 60% by weight parts of 2-ethylhexyl acrylate, 10 to 60 parts by weight of butyl acrylate, 5 to 40 parts by weight of ethyl acrylate, 2 to 7 parts by weight of acrylic acid and 0.5 to 5 parts by weight of methacrylamide, optionally 0.5 to 8 parts by weight of hydroxyethyl methacrylate and optionally modified with 0.01 to 1 part by weight of dodecylmercaptan or a mixture of said acrylic copolymer dispersion with acrylic / vinyl monomer copolymer dispersion especially from the group comprising vinyl acetate, styrene, methyl methacrylate, methacrylamide and glycidyl methacrylate, in a weight ratio of 1: 2 to 10 and optionally up to 400 parts by weight of additives from the group comprising fillers, modified or unmodified natural and / or synthetic resins, wetting and dispersing additives , defoamers, thickeners, coalescents, antifungal additives, pigments and dyes.