INVENTION
Patent of the Russian Federation RU2287001
TERMOKLAY FOR GLINING AND SEALING

TERMOKLAY FOR GLINING AND SEALING. GLUE. ADHESIVE COMPOSITION. KNOW HOW. INTRODUCTION. PATENT. TECHNOLOGIES.

INVENTION. TERMOKLAY FOR GLINING AND SEALING. Patent of the Russian Federation RU2287001

Applicant's name: Closed Joint-Stock Company Stroypolimer Scientific and Production Association (RU)
The name of the inventor: Hayrullin Ilnur Ilyasovich (RU); Ustyugova Olga Vladimirovna (RU); Hayrullin Ilyas Karipovich (RU); Pomanskaya Marina Pavlovna (RU); Kutyrkin Igor Vyacheslavovich (RU); Mischenko Elena O. (RU); Pluzhnov Stanislav Konstantinovich (RU)
The name of the patent holder: Closed Joint-Stock Company Stroypolimer Scientific and Production Association (RU)
Address for correspondence: 140093, Moscow Region, Dzerzhinsky, ul. Tomilinskaya, 23, apt.28, I.I. Khayrullinu
Date of commencement of the patent: 2005.07.20

The invention relates to hot melt adhesives or hot melt adhesives used for gluing or sealing pipelines from polyolefins, gas and oil pipelines, docking assemblies of an electric cable in the cable industry, for gluing polymer roofing materials, in household and other industries. The technical task is to provide the necessary physical and mechanical characteristics when gluing hard-to-stick products from polyolefins, polymer roll materials to various substrates in a wide range of temperatures and reliable operation of products under conditions of alternating cyclic stresses. The problem is solved by the fact that the adhesive contains an ethylene vinyl acetate copolymer, a mixture of an ethylene vinyl acetate copolymer with vinyl acetate units of 10-14 wt% and an ethylene vinyl acetate copolymer having a vinyl acetate unit content of 21-24 wt% or an ethylene vinyl acetate copolymer containing vinyl acetate 26-30% by weight, with a ratio of respectively 1: 2 to 1: 4, tackifier is a mixture of rosin or its derivatives with a hydrocarbon resin at a ratio of 1: 0.5 to 1: 2.0, respectively, a plasticizer , And additionally a stabilizer and a filler.

DESCRIPTION OF THE INVENTION

The invention relates to hot melt adhesives or hot melt adhesives used for bonding various surfaces (polymeric materials and articles, metals, glass, wood products, textiles, paper, etc.) and specifically relates to tape melt adhesives used for bonding and sealing pipelines From polyolefins for their manufacture and assembly, for gluing of polymeric roofing materials, for gluing and sealing the docking assembly of the electric cable in the cable industry, for the anticorrosion protection of gas, water, oil pipelines, etc.

Adhesives-melts are usually called thermoplastics, which turn into a viscous-flowing state when heated and again solidify upon cooling. Most widely found are hot melt adhesives based on copolymers of ethylene with vinyl acetate with a vinyl acetate content of 15 to 40% by weight. They have good adhesion to many substrates, are well compatible with other components of adhesives, have the greatest stickiness and frost resistance. In order to increase the adhesion characteristics, rosin is introduced into the melt adhesives in amounts of 35-45% by weight. Melt adhesives based on EVA copolymers well bond aluminum foil, kraft paper, polyethylene, but most of them do not have increased heat resistance, stiffness and adhesion to most substrates under severe conditions of bonded materials and products (DA Kardashov, A. P. Petrova, "Polymer Glues", Moscow, Chemistry, 1983, p.95-96).

To improve the technological and operational properties, various additives are introduced into the hot melt adhesive based on EVA copolymers.

From RU 665701, 10.01.1996, a hot melt adhesive based on an ethylene-vinyl acetate copolymer with vinyl acetate groups of 10-30%, with the addition of an adhesive additive (roughening agent-rosin, glycerol ester of rosin), plasticizer (dibutyl phthalate, dioctyl phthalate, dioctyl sebacate, Paraffin), and in which, to increase the adhesion to various materials and reduce the thermal activation temperature, polyethylene oxide with M.M. 750000-1000000.

The obtained glue can be applied to a paper substrate at a temperature of 130-150 ° C. When producing heat-sensitive tapes with an adhesive layer, the surface of the layer is subjected to treatment with a wool sealant; The heat-sensitive paper tape was activated at 80-100 ° C and adhered to the surface of various substrates. The adhesive provides resistance to peeling of the paper tape from steel 0.35-0.55 kgf / cm, aluminum 0.39-0.45 kgf / cm, polyethylene 0.35-0.41 kgf / cm. However, this known adhesive can only be used to glue polymer film materials in furniture production, paper and cardboard in the printing industry and to produce heat-sensitive packaging and labeling tapes.

From RU 2112005, May 27, 1998, another adhesive melt containing an ethylene vinyl acetate copolymer with a vinyl acetate content of 5-24% by weight, butadiene-styrene thermoplastic elastomer, glycerin rosin ester (tackifier), stabilizer (e.g. 2,2-methylene - (6-t-butyl-4-methylphenol)), in which paraffin and terpene oil are additionally added. As EVA copolymer, it contains an EVA copolymer with a vinyl acetate content of 10-14%, or an EVA copolymer with a vinyl acetate content of 21-24%. This glue, however, is intended for use in the printing industry for the manufacture of books by the method of seamless binding and ensures the durability of the glued joint of the book blocks.

Melt adhesives are also used to make sticky tapes. As a rule, in this case, they contain the following components: binder (in most cases elastomers), tackifier (rosin derivatives and terpenic resins), plasticizer, stabilizer, antioxidant; Copolymers of ethylene with vinyl acetate are most often used for such adhesives. Adhesive tapes are materials consisting of a base and a sticky adhesive layer. Various film materials (polyethylene, cellophane, polyvinyl chloride, foil, paper, fabric, rubber, plastic) are used as the basis. The surface of the substrate before the application of the adhesive can be activated by chemical means, by mechanical treatment, etc .; When obtaining adhesive tapes in order to avoid tape sticking when winding in a roll, the adhesive layer is duplicated with a polymer film or paper. Melt adhesives are applied to the substrate by extrusion, melting and rolling method, spraying through a nozzle, squeezing monofilaments of glue onto the substrate (DA Kardashov, AP Petrova, "Polymer Glues", M., Chemistry, 1983, p.97,145 -146).

From SU 1147732, 30.03.1985 is known glue-melt for the production of adhesive tapes, containing butadiene-styrene thermoplastic elastomer, liquid carboxyl-containing butadiene nitrile rubber, low molecular weight polyisobutylene with M.M. 10000-20000, ethylene vinyl acetate copolymer with vinyl acetate content of 17-33%, tackifying agent (rosin, ethers, polyterpene, phenol formaldehyde resins, coumaronindene resins), plasticizer (phthalic and sebacic acid esters). This adhesive has an increased resistance to steam, salt mist and polymer varnishes, and high adhesion values, but it is mainly used for the marking and packaging of instruments, products and equipment. The adhesive is applied uniformly onto paper or other substrates by extrusion at 200 ± 10 ° C and protected with antiadhesive paper.

From SU 523925, November 30, 1976, a temperature- sensitive roll gluing material consisting of a reinforcing support coated with a vinyl acetate-dibutyl maleate copolymer layer is known and, on one or both sides, is additionally coated with a layer of water-insoluble polyvinyl alcohol to prevent self-adhesion of the material in the roll, This gluing material is intended only in the printing industry for bonding clichés and stereotypes.

From SU 747870, 15.07.1980 adhesive for sticky tapes with a polyethylene substrate, intended for insulation of gas and oil pipelines and in everyday life, is known. The adhesive contains low molecular weight polyisobutylene, high molecular weight polyisobutylene, butyl rubber, an adhesive additive (tackifying agent-glycerol ester of rosin, polyterpene resin, PBS, resin 101K), condensation product of methylsilantriol and phenylsilanetriol and a solvent (a mixture of gasoline and toluene). The adhesive has good adhesion and cohesive properties, but belongs to toxic and fire-dangerous products because of the presence of a sufficiently large amount of solvent in its composition, i.e. Does not apply to hot melt adhesives, which limits its use.

From SU 861380, 09.09.1981, a glue-melt adhesive is known for the production of adhesive tapes on paper and polymer substrates containing an ethylene vinyl acetate copolymer with a vinyl acetate content of 11-45% by weight, an adhesive additive (tackifier) ​​is a mixture of extraction rosin and glycerol ester Rosin, plasticizer - dioctyl phthalate and, possibly, an antioxidant (neozone A or D, hydroquinone, pyragallol). The adhesive has good adhesion and cohesive properties, but is mainly intended for labeling, marking, gluing of roll material in processing, gluing containers.

According to the technical essence and the result achieved, the above-described known adhesive melt for producing adhesive tapes (roll bonding material) according to SU 1147732 is closest to the claimed invention.

The technical problem of the claimed invention is to provide the required physico-mechanical characteristics when gluing difficult-to-attach articles from polyolefins, polymer roll materials to various substrates in a wide temperature range and reliable operation of products under alternating cyclic stresses.

The stated technical problem is achieved by the fact that the hot melt adhesive comprising an ethylene-vinyl acetate copolymer, a tackifier and a plasticizer contains as a polymer binder a mixture of an ethylene vinyl acetate copolymer with a content of vinyl acetate units of 10-14% by weight with an ethylene vinyl acetate copolymer containing vinyl acetate units 21-24% by weight or with a copolymer of ethylene with vinyl acetate having a content of vinyl acetate units of 26-30% by weight, with a ratio of respectively 1: 2 to 1: 4, as sticking agent, a mixture of rosin or its derivatives with a hydrocarbon resin From 1: 0.5 to 1: 2.0, respectively, and in addition a plasticizer, filler and stabilizer with the following ratio of components in mass%:

TERMOKLAY FOR GLINING AND SEALING

The hot melt adhesive of the invention contains various rosin derivatives (cavernophyte esters, hydrogenated or disproportionated rosin) as rosin esters, for example, glycerol rosin ester; As a hydrocarbon resin, for example, indene-coumarone resin, polyterpene resin, various aliphatic and aromatic petroleum-polymer resins, as plasticizer, oligomeric (low molecular weight) rubbers, for example, polyisobutylene with M.M. 5000-20,000, paraffin, dibutyl phthalate, dioctyl phthalate, dioctyl sebacate; As a filler - chalk, soot, titanium dioxide, zinc oxide, aerosil; As a stabilizer, for example phenolic type stabilizers, in particular 2,2'-methylene- (6-tert-butyl-4-methylphenol, various gerganoxes-4,4'-butylidenbis (2-tert-butyl-5-methylphenol), N-phenyl -N-isopropyl-p-phenylenediamine and others.

Hotmelt is prepared, for example, according to the following technology. A mixture of rosin or its ester with a hydrocarbon resin, a plasticizer and a stabilizer is charged into a mixer with a Z-stirrer preheated to 135-150 ° C. At the end of melting of the tack agents, a mixture of ethylene-vinyl acetate copolymers is charged to the mixer and mixed for 40-50 minutes until a homogeneous mixture is obtained. Fillers are then added to the mixer and the contents of the mixer are further stirred for 20-30 minutes. Table 1 shows examples of the hot melt adhesive compositions of the invention, and Table 2 shows the basic physico-technical and operational properties.

TERMOKLAY FOR GLINING AND SEALING

TERMOKLAY FOR GLINING AND SEALING

The high degree of reliability of bonding using the hot melt according to the invention and sealing of the pipeline junction assembly was confirmed during the rapid assessment of the serviceability of the couplings under alternating cyclic loads for compliance with the requirements of the European standard EN 489.

The load test is carried out in a sandbox simulating a pipeline under the ground at a depth of 2.5 meters when the clutch moves cyclically in a layer of sand with an amplitude of 50 mm / min.

The clutch samples survived at least 1000 test cycles, which corresponds to the required 30 years of service of the heat conductor. Further tests showed that the clutch maintains its integrity for more than 5000 cycles.

The following is an example of the use of hot melt adhesive according to the invention in the form of a tape bonding material for insulation of the heat pipe joint.

The pipeline consists of a steel pipe - a core and an outer shell of linear polyethylene, the space between which is insulated with polyurethane foam.

The heat-shrinkable coupling made of radiation-cross-linked polyethylene is installed on an external polyethylene sheath before welding the steel pipe. Insulation work begins after quality control of the welded steel pipe.

On the surface of the outer polyethylene sheath, on both sides of the joint, the tape hotmelt according to the invention is glued by residual tack. The edges of the coupling are seated with a soft flame of a gas burner at a temperature of 115-130 ° C. At the same time, due to the melting of the hot glue, a simultaneous gluing and sealing of the joint occurs. Checking the tightness is made by pressing the joint with compressed air.

At the end of shrinkage of the coupling, gluing and sealing of the docking assembly, the joint is heat-insulated by pouring a mixture of polyurethane components into the space under the coupling. The filling hole is closed by a drain plug. After the foam has hardened, the drain plug is removed and the filling hole is closed with a plastic stopper. The finished insulated joint is barrel-shaped.

CLAIM

A hot melt adhesive for gluing and sealing, comprising an ethylene vinyl acetate copolymer, a tackifier, a plasticizer, characterized in that it comprises a mixture of an ethylene vinyl acetate copolymer having a vinyl acetate unit content of 10-14% by weight and an ethylene vinyl acetate copolymer containing vinyl acetate units 21-24 Wt% or copolymer of ethylene with vinyl acetate with a content of vinyl acetate units of 26-30% by weight, with a ratio of respectively 1: 2 to 1: 4, as sticking agent, a mixture of rosin or its derivatives with a hydrocarbon resin at a ratio of 1: 0.5 to 1: 2.0, respectively, and additionally a stabilizer and a filler with the following component ratio, by weight:

print version
Date of publication 18.12.2006гг