DE2609266C2 - Method for the adhesive connection of surfaces, in particular for the adhesive connection of shoe soles with shoe uppers - Google Patents

Description

2. The method according to claim 1, characterized in that in step a) the prepolymer through Heating to a temperature above its crystalline melting point in a flowable state

20 has been convicted.

3. The method according to claim 1, characterized in that in step a) the prepolymer through Dissolving in a volatile organic solvent has been rendered flowable.

4. The method according to any one of claims 1 to 3, characterized in that in step a) as a polymer Polyol is a hydroxyl-terminated polyester from the group of polycaprolactones and aliphatic Polyesters of dicarboxylic acids having 6 to 12 carbon atoms and glycols having 2 to 6 carbon atoms a molecular weight of 2000 to 4000 and a crystalline melting point of 40 to 60 ° C is used is, wherein the diisocyanate and the polyol are reacted with one another in proportions such as that an NCO / OH ratio is obtained which is within the range from 1.5: 1 to 2.5: 1.

5. The method according to any one of claims 1 to 4, characterized in that one is active in step b) Hydrogen atoms supplying compound used water, in the form of a gas or in the form of

Water vapor is present.

6. The method according to any one of claims 1 to 5, characterized in that in step c) with the the chain extender treated prepolymer by heating to a temperature around is at least 5 ° C above its crystalline melting point before the adhesive bond is made in

35 transferred a viscoelastic state.

7. The method according to any one of claims 1 to 6, characterized in that in step a) as Shaped body (object) a shoe sole part is used and that in step c) as a second shaped body (Object) a shoe upper is used, whereby the cover is put on before the chain is extended a temperature below the crystalline melting point of the prepolymer cools and for the chain

40 extension water vapor with a temperature of 32 to 95 ° C is used.

8. The method according to any one of claims 1 to 6, characterized in that in step a) as Shaped body (object) a shoe sole part is used and that in step c) as a second shaped body (Item) a shoe upper used, whereby before the chain extension the volatile organic Liquid is evaporated from the coating and water vapor with a chain extension

45 temperature of 32 to 95 ° C is used.

9. The method according to any one of claims 1 to 8, characterized in that one in step a) Prepolymer used, which is a catalyst for the reaction between the prepolymer and the contains active hydrogen atom-donating compound.

10. The method according to any one of claims 1 to 9, characterized in that on both surfaces a prepolymer of the same class is applied to the molded bodies (objects) to be bonded to one another.

The invention relates to a method for the adhesive connection of surfaces, in particular to the adhesive Connection of shoe soles (treads) with shoe uppers.

When fastening shoe soles (treads) such. B. outsoles, on shoe uppers must Adhesive can be applied in a flowable state so that it can join the surfaces to be joined wet and can penetrate into this limited. It is also true that the adhesive should then be tough and strong will. The initial flowability has so far been through the use of solutions of adhesives in volatile organic solvents that reduce strength and toughness after application Evaporation of the solvent developed, achieved. However, these solvent adhesives need a certain amount Time for the adhesive to dry and are flammable because of the solvent vapors that are generated and harmful to health.

Hot melt adhesives have also been used; H. hot melt adhesives. However, since a relatively high temperature is required to reduce the viscosity of the adhesive to one for the This creates a sufficiently low level of wetting of the surfaces with the adhesive

Problems both from the degradation (decomposition) of the adhesive and, in some cases, from the Damage to the surfaces to be connected. It also provides the relatively short processing time undesirably high time requirements for the union of the surfaces with the still flowable Glue in between.

The aim of the present invention is therefore to provide a method for adhesively connecting surfaces under Specify the use of a prepolymer or adhesive that works at relatively low temperatures is initially flowable so that it is easier to make a wetting adhesive bond to a surface can, and that through a relatively mild treatment into a tough, firm, but through heat softenable state can be converted, so that a virtually instant solid adhesive bond with a compatible (compatible) adhesive or resin surface.

This object is achieved according to a method according to claim 1. Preferred embodiments can be found in the subclaims.

According to a feature of the present invention, a prepolymer with terminal - NCO groups, which has been prepared by reacting a diisocyanate with a polymeric polyol in proportions such that an NCO / OH ratio which is within the range of 1.25: 1 to 3.0: 1, which has a crystalline melting point within the range of 40 to 90 ^° C., and a molecular weight within the range of 1,000 to 10,000, and which has been put in a flowable state, onto the surface of a Molded body (article) applied This prepolymer is also referred to below as an adhesive

The prepolymer is made by reacting with a chain extender, which is a compound with active hydrogen atoms, which react with the - NCO groups of the urethane, are contained in a tough, solid Transferred state. The prepolymer treated with the chain extender is then after Softening by heat treatment against a surface compatible with it, the first with the said surface is to be connected, pressed to produce an adhesive bond, and this The compound is then cooled so that it turns into a hard, solid state. That the subject The method forming the invention is primarily suitable for the production of adhesive bonds, especially for gluing shoe soles (treads) with shoe uppers, and is referred to below under Reference to this preferred use described in more detail. The method according to the invention is suitable however, it is also suitable for the adhesive bonding of other surfaces, such as B. those made of wood, resin or Rubber materials, metal and fabrics as well as in reinforcing and stiffening sheet materials such as / .. B. to stiffen the toes or heels of shoes.

The invention is explained below with reference to the accompanying drawing. It shows

F i g. 1 is a perspective view of an outsole fastening device incorporating a strip of adhesive applies to the attachment edge of an outsole;

Fig. 2 is a schematic elevational view showing the activation of the adhesive on an outsole and shows the shoe upper by radiant heating, and

Figure 3 is a schematic elevational view showing the bonding (gluing) of an outsole to a Shows shoe upper (shoe upper leather) in a sole fastening press.

As shown in FIG. 1, a strip 10 made of the prepolymer is used to glue the outsole (Adhesive) in the flowable state on the fastening edge of an outsole 12, preferably by means of a Outsole fastening device 14, applied. The outsole fastening device 14 consists of a nozzle 16 for applying and distributing the adhesive, a drive wheel 18 for transporting the outsole 12 at the desired speed past the nozzle 16, and a guide device 20 to the To hold the edge of the outer shell 12 in the desired position opposite the nozzle 16. As in Fig. 1 shown a strip 10 is applied by means of the fastening device, which extends at least around the front Section of the outsole 12 extends, but the strip 10 can also extend around the entire edge of the Outsole extend, depending on the structure of the shoe to be manufactured. It can be the same or a different one Compatible (compatible) adhesive also on the bonding surface of the bottom of a shoe upper (Shoe upper leather) are applied. The applied adhesive is then exposed to moisture, expediently in a steam chamber or in another device for generating moisture, and preferably the applied adhesive is heated in order to bring about chain extension.

After the chain extension of the adhesive, the outsole 12 and a shoe upper 72 are on one Frame 26, which is arranged at a distance from a radiation heating unit 28, applied to the Heat the adhesive to a temperature above its crystalline melting point and turn it into a Bring viscoelastic state, the adhesive on the bond surface 24 on the Lower part of the upper part of the shoe is located. After heating the glue on the underside of the shoe upper leather 22 and on the outsole 12, the outsole 12 is placed on the underside of the shoe upper 22 and the composite of the outsole 12 and the shoe upper 22 is placed in a sole bonding press 30 (see FIG. 3) and glued under pressure

The method according to the invention offers the advantage of the ordered sequence of development of physical Properties resulting from the effects of temperature and chemicals on the adhesive with the crystalline properties of the segments of the resin and the relatively low molecular weight of the adhesive. The adhesive is applied. Application converted into a flowable form, preferably by heating it to melt or by adding a solvent.

If the adhesive is applied in molten form, a temperature above b5 the crystalline melting point of the prepolymer applied to this for the crosslinking adhesive bond with a surface that is to be glued therewith to impart required flowability. This here The term "crystalline melting point" used stands for the temperature at which the crystalline segments

of the prepolymer melt and it is determined as the temperature of the main endothermic maximum in a differential thermal analysis. If the prepolymer when activated to a temperature is brought above this temperature, the crystalline segments melt and cause the Coating or film becomes soft. After application, the adhesive is preferably brought to a temperature brought below the crystalline melting point and allowed to crystallize in order to achieve sufficient stability against flow (creep) and deformation at the temperatures used in the subsequent stage to develop.

According to a further preferred embodiment, the adhesive is by dissolving the same in one inert volatile solvent! for application at room temperature or at slightly elevated temperatures brought into a liquid form. Examples of such solvents are volatile organic liquids, the does not contain active hydrogen. Such solvents include e.g. B. ByIoI, Tuluol, Dimethylformamide, Acetone, methyl ethyl ketone, ethyl acetate, cellulose acetate, methylene chloride and mixtures thereof. Particularly advantageous solvents are mixtures of tuluene with up to about 85% by weight (based on the weight of the Solvent mixture) methylene chloride or methyl ethyl ketone. Due to the nature of the in the invention Process used prepolymers have solutions with a relatively high solids content, For example, from 60 wt .-% and more, viscosities that are necessary for the order to achieve a Adhesive bond with surfaces are sufficiently low. Lower percentages of solvents can also be used if desired, the prepolymer can be used at moderately elevated temperatures apply that are below the temperatures required to melt the prepolymer in the absence of solvents are required. If the applied adhesive is in the form of a solution, that will Solvent preferably evaporated before the subsequent treatment

In step (b) of the process according to the invention, the active isocyanate groups of the adhesive are in the heat or at moderately elevated temperatures with a chain extender that contains at least two provides active hydrogen atoms, such as water vapor, or similar chain extenders converted to the adhesive in a tough, flow (creep) resistant, but heat softenable state bring to. In the state treated with the chain extender, it is the crystalline melting point compared to that of the original prepolymer practically unchanged, so that when this on heating to a temperature above the crystalline melting point associated with the chain extender treated prepolymer becomes viscoelastic (flowable), namely somewhat rubber-like, but deformable and flowable under pressure; the prepolymer treated in this way is sticky and able to come into contact with a compatible (compatible) surface, such as B. made of wood, metal or a fabric with the same or a compatible adhesive (prepolymer) or with a resin, such as. B. a vinyl resin, is coated to be adhesively bonded. Due to the visco-elastic state and somewhat rubber-like physical state of the adhesive treated with the chain extender at temperatures Above its crystalline melting point, due to the contact of the adhesive surface with a other surface bonds produced a very high initial bond strength, so that for example at Gluing a shoe sole to a shoe upper, the tendency of the sole to move away from the upper due to to separate the resilience of the sole, is turned off.

The adhesive, which develops the successive advantageous physical states in the successive physical and chemical treatments, is based on a prepolymer with terminal - NCO, which is produced in the reaction of a polyol with a relatively low molecular weight and a crystalline melting point within the range from 40 to 90 ^° C. , preferably from 40 to 65 ° C, is obtained with excess diisocyanate.

Preferred polyol materials are the hydroxyl terminated polycaprolactones and polyesters aliphatic dicarboxylic acids having 6 to 12 carbon atoms, such as. B. sebacic acid, adipic acid, azelaic acid, Suberic acid and dodecanedioic acid with preferably even-numbered glycols with chains of 2 to 6 Carbon atoms such as 1,4-butanediol. The acid component of the polyester polyol can be about 5 to about 25% (on a molar basis) a cycloaliphatic acid such as 1,4-cyclohexanedicarboxylic acid or 1,2-cyclohexanedicarboxylic acid, to promote adhesion, especially to resin-rubber surfaces, and about 5 to about 25% so (based on Moi) an aromatic dicarboxylic acid, such as terephthalic acid or isophthalic acid, for improvement the resistance to plasticizers included. The glycol component can be about 5 to about 15% (based on molar basis) diethylene glycol or a cycloaliphatic glycol such as 1,4-cyclohexanedimethanol included to improve the adhesive and wetting properties and better reactivity to give with steam. These polyols have a molecular weight within the range of 1,000 to 10,000, preferably from 2,000 to 4,000.

The prepolymer which is applied to the surface to be bonded is produced by reacting one or more of the polyols given above with a diisocyanate in proportions such that an NCO / OH ratio is achieved within the range from 1.25 to about 3 , 0, preferably in the range from 1.5: 1 to 2.5: 1. Any diisocyanate can be used, such as. B. tolylene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate. B. to incorporate an acid chloride such as benzoyl chloride, acetyl chloride or sebacoyl chloride in an amount of about 0.05 to about 02 wt .-%, based on the prepolymer.

It has been found that the prepolymers prepared using diphenylmethane diisocyanate react with water much faster than prepolymers made using tolylene diisocyanate have been produced, but on the other hand the last-mentioned prepolymers during storage are more stable An improved shelf life combined with a faster reaction rate can be achieved by a combination of both diisocyanates. Because of the differences in terms of the

It is preferred to add the tolylene diisocyanate first and use it for a limited reaction rate Allow time to react so that the NCO group in the p-position can react with the polyol, after which the Diphenylmethane diisocyanate can be added. Diphenylmethane diisocyanate and tolylene diisocyanate are preferred used in a molar ratio in the range from 50:50 to 80:20.

The rate of the ketiene extension reaction of the prepolymer can be adjusted by using Catalysts are increased. Preferably, therefore, in stage (a) of the process according to the invention, a Prepolymer used, which is a catalyst for the reaction of the prepolymer with the active hydrogen atoms supplying compound. If a chain extension is caused by moisture, tertiary amines such as N-methylmorpholine, triethylenediamine and other known catalysts such as Dibutyltin dilaurate and tin (II) octoate, are incorporated into the prepolymer. Amounts of catalyst are preferred from 0.05 to 1% by weight, based on the weight of the prepolymer, is used.

Although the prepolymer itself makes an excellent adhesive, it may be useful to incorporate other materials such as plasticizers, fillers, and tackifiers. Plasticizers, in particular normally solid plasticizers, serve both to reduce the viscosity of the prepolymer when it is in the melted state and to modify the properties of the finished film. Plasticizers that are valuable in connection with the prepolymer include dicyclohexyl phthalate, triphenyl phosphate, diphenyl phthalate and cycloaliphatic epoxides or epoxy monomers of the bisphenol Α type. Tackifiers that improve adhesive bond include hydrocarbon-type tackifiers such as terpenes, e.g. B. x- and / 7-pinene polymers, styrenes with low molecular weight, such as poly - «- methylstyrene and rosins. Inert fillers, such as. B. clays, carbonates, titanium dioxide and others are incorporated.

It was found that the crystalline melting point due to the reaction of the diisocyanate with the polyol rises only a few degrees above the crystalline melting point of the polyol itself. if for example a butanediol sebacate polyol with a crystalline melting point of 49 ° C with diphenylmethane diisocyanate is reacted in an NCO / OH ratio of 1.5: 1, so the prepolymer obtained has a crystalline melting point of only 54 ° C.

The prepolymer can be applied in the flowable state to a surface, for example to the sole bonding surface on the underside of a shoe part or on the bonding surface of an outsole using a conventional application device or even by hand. It has been found that relatively low application temperatures, e.g. B. Temperatures of 80 to 100 ⁰ C, with solvent-free prepolymers (polyurethane materials) with crystalline melting points of up to about 70 ⁰ C are suitable. Solvent-containing prepolymers can be applied at room temperature or at slightly elevated temperatures.

It is useful that the thickness of the films from the prepolymer is uniform so that the effect of the Chain extender is uniform over the entire extension of the thickness of the film. Preferably the film has a thickness of 0.025 to 0.125 mm (1 to 5 mils) for most satisfactory results and uniform chain elongation throughout the thickness of the film. Relatively thin films whose Thickness is only 0.025 mm, are on relatively regular surfaces, such as. B. the bonding surface an outsole, effective, while films a thickness of 0.075 mm on more irregular surfaces, such as z. B. the sole bonding surface on the underside of a shoe upper can be applied. After the prepolymer has been applied, the material of the film is preferably allowed to crystallize before it is subjected to chain lengthening. The crystallization serves to prevent the material from being deformed Flow of the applied material under the higher temperatures experienced by the film in the chain extension stage exposed to make permanent.

In order to bring the applied prepolymer into the state desired to achieve a bond, it is subjected to a chain extension treatment in which the surface of the film or adhesive a compound with two active hydrogen atoms for the reaction with the NCO groups of the Exposing prepolymer. A preferred chain extender is water, preferably in the form of Water vapor or gaseous water, e.g. B. in a room with high humidity or near one Water vapor queue. Other chain extenders such as diamines or glycols can also be used will. Temperatures slightly above are preferably used in the chain extension stage Room temperature, and with a relative humidity of about 50 to 95%, temperatures of 32 to 95 ° C has been shown to be beneficial in order to achieve chain extension at an acceptable rate, for example within about 10 to about 30 minutes, without deformation of the Film or adhesive occurs The chain extension reaction should be carried out until the film at the Heat activation is elastoplastic, but not noticeably crosslinked, d. H. the film is still soluble or from active solvents such as dimethylformamide or tetrahydrofuran is attacked.

After chain extension and after removal of the free water or other chain extenders from the surface of the coating, the film can be heated to bring it into an active adhesive state. Radiant heating is preferably used, but other forms of heating, such as, for. B. convection heating can be used. The heating should be carried out in such a way that at least the surface of the prepolymer film is brought to a temperature above the crystalline melting point, preferably to a temperature within the range from about 49 to about 82.degree. C., quickly, preferably within 15 to 30 seconds is, so that at least the surface is in a viscoelastic state that is compatible with a compatible surface, such as. B. a vinyl resin or adhesive layer on the object to be bonded to the coated surface, can create an adhesive bond. When using Präpoiymerisaten having crystalline melting points of up to 70 ⁰ C bonds excellent at bonding temperatures of only 5 ⁰ C above the crystalline were

Melting point achieved.

To complete the adhesive bond the surfaces are used with the one in between heat-activated prepolymer brought together and the resulting composite is a print exposed to ensure good overall bonding. It was found that after the initial Put the surfaces together before applying pressure because of the visco-elastic state of the adhesive can still be moved against each other to a limited extent, but that after the application of pressure a bond with a high initial strength is achieved on the composite. The finished binding (after the Cooling the adhesive) has excellent toughness and flexibility, so that the adhesive with Success can withstand the stresses involved in using a shoe with the means of the invention Occurrence of adhesive attached to the sole.

The joining method according to the invention has been described above with reference to the application of the adhesive in the flowable molten state or in the form of a solution describes the process but can also be carried out in such a way that the treated with the chain extender Adhesive used in the form of a film applied to a carrier or in the form of a self-supporting film and connects it in the heat-activated form with a compatible surface as a film or arranged between compatible surfaces as an adhesive bond between the surfaces.

The invention is illustrated in more detail by the following examples.

example 1

A prepolymer with terminal NCO was made by reacting a butanediol adipate polyester with terminal hydroxyl and a molecular weight of 2600 and a crystalline melting point of 49 ° C with diphenylmethane diisocyanate in proportions such that an NCO / OH ratio of 1.5 was obtained. The prepolymer obtained in this way had a melting point of 54 ° C. and was at a viscosity of 8000 cP at 100 ° C flowable. In those above and in those below Melting points given in the examples were crystalline melting points, which were used as endothermic maxima determined by differential thermal analysis.

The prepolymer was melted and brought to a temperature of 100 ° C and in the form of a 0.075 mm thick film on the previously roughened sole bonding surface of a shoe upper leather as well as on the Bonding surface of an outsole made from a vulcanized synthetic butadiene-styrene mixed polymer rubber applied. The applied films were left at 70 "C for 15 minutes High humidity atmosphere in a warming cabinet exposed to through a reaction between the moisture and the NCO groups of the prepolymer to achieve chain extension. After this Treatment, the material of the films was tough, it adhered firmly to the bond surface and was able to withstand Temperatures from 65 ° C to a tacky state that adhered to similar adhesive surfaces, soft be made. The films on the bond surfaces were subjected to infrared heat activation for 30 seconds in a radiant heat activator with the thermal unit set to 60% power. The sole was pressed against the bonded surfaces of the underside of the shoe upper and the point bonded was excellent The entire assembly was pressed to order in a sole paste-up press to complete the bond. A strong initial bond was created without any separation or "wrinkling" occurred and the bond strength was satisfactory for the use of the shoe.

Example 2

2.54 cm χ 17.78 cm wide test strips of the enumerated in the further Table I below were materials with the molten prepolymer of Example 1 at 80 to 90 ° C to obtain a layer thickness of 0.075 mm coated after 15 minutes, measured from After applying the coatings, the strips were placed in a high humidity atmosphere in a heat cabinet at 70 ° C or in a room of about 36 ° C and a relative humidity of 68% for chain extension for the periods of time shown in the table below reach. The strips were then activated by infrared heating in a conventional Radiant Heating Activator (RHA) for 30 seconds with the activator heating unit set at 60% power. Activation increased the temperature of the coatings on the strip to about 68 to 75 ° C. The strips are then activated, indicated as ** in the following Table I, together in pairs and to complete the

j 55 bonds are pressed together, after which the combined strips are cooled to room temperature and

* the bonds achieved were subjected to a test. The results of these tests are also in the

given in the following table.

Tabel

Prepoly test Substrate Curing Activation conditions Point- Peel strength Peel strength Dead load merisat No. conditions time after d. d. RHA- bonding at the start (Peel strength) at No. Harden Setting (Initial binding) the 16 day old 65.56 ° C N / cm Bond N / cm

SBR sole material

the same
the same
the same

leather

SBR-Sole-Stick-Mnteriul
the same

the same

Vinyl top material
leather

15 min. 7O ⁰ C water vapor

10 min. 7O ⁰ C water vapor for 15 min. 70 ° C water vapor 10 70 ⁰ C water vapor min.

the same

Min.

the same
Hours.
the same

30 seconds at 60%

like. like. like.

the same.

bad

the same very good the same

the same

small amount

the same

77.85

RF

48.44 RF

39.79 RF

34.60 VF

128.02

LF

5.08 cm per hour

0 cm per hour

1 6th SBR sole SBR sole 15min 70 ° C 16 days the same out very high 60.55 RF K) material material Steam draws Oi 1 7th the same Vinyl- the same the same the same the same the same 62.28 RF - Top part material I. 8th the same leather the same the same the same the same the same 48.44 - 1 9 the same the same 22 hours 35.6 ° C 60 min. the same very good 32.89 38.06 5.08 cm 68% RH 1 10 SBR sole Vinyl- 22 hours 35.6 ° C 25 hours 30 sec. out 27.70 41.52 material Upper part 68% RH at 60% draws material RF = Rubber breakage VF = Vinyl breakage LF - Leather breakage

Example 3

A prepolymer with terminal NCO was made by reacting a butanediol adipate polyester with

terminal hydroxyl groups with a molecular weight of 3000 and a melting point of 50 ⁰ C with a mixed diisocyanate in a molar ratio of 2 parts of diphenyl methane diisocyanate to 1 part of tolylene diisocyanate in amounts such that an NCO / OH ratio was obtained of 2.0, manufactured Dabei The prepolymer obtained had a melting point of 54 ° C. and a viscosity of 11,000 cP

100 ⁰ C flowable.

There were 234 cm by 17.78 cm test strips of an outsole sheet material that was a

ίο styrene / butadiene block copolymer, the surface of which has been chlorinated, cut from a polyvinyl chloride outsole sheet material and a styrene / butadiene copolymer outsole material. Similar strips were also cut from the upper part material (upper leather material), which contained the polyvinyl chloride applied to a backing, and leather
The strips of the outsole material were coated with the molten prepolymer at 80 to 90 ^° C. to achieve a film thickness of 0.075 mm, and after the films had been applied and cooled, the strips were placed in an atmosphere with a high humidity of 90 for 1/4 hour % relative humidity (RH) placed in a heating cabinet of 70 ^° C. The strips of the upper material (upper leather material) were each coated with a polyurethane adhesive of the solvent type on the polyvinyl chloride upper material provided with the underlay and with a phenolic resin-polychloroprene sole bonding agent of the solvent type coated on the upper leather material. In each case the applied adhesive film was allowed to dry to remove the solvent.

The surfaces of the outsole material and upper material test strips coated with the adhesive were placed in a radiant heat activator for 10 seconds with the radiant heat unit was set to an output of 55%. The surface temperature of the adhesive on the

25 surfaces of the strips was 80 ° C

Strips of the adhesive coated, backed polyvinyl chloride upper material were made with strips of the adhesive-coated Bolck polymer outsole material and combined with the styrene / butadiene copolymer outsole material and strips from the Leather coated with the adhesive was combined with the polyvinyl chloride outsole material and the composite assemblies were pressed to complete the bonds. When tested after 7 days the peel strengths (peel bond strengths) were 44.71 N / cm between the polyvinyl chloride material and the block copolymer 36.8 N cm- 'between the leather and the polyvinyl chloride outsole material and 67.60 N / cm between the polyvinyl chloride material and the styrene / butadiene copolymer outsole material.

³⁵ Example 4

A prepolymer with terminal NCO was prepared by reacting diphenylmethane diisocyanate with a polycaprolactone with a molecular weight of about 2860 and a melting point of 54 ° C., the prepolymer having a content of free NCO groups of 2.18%. The prepolymer was melted and brought to a temperature of 100 ⁰ C and in the form of a 0.075 mm thick film on a previously roughened surface of an outsole material consisting of a styrene / isoprene / styrene block copolymer is applied. The applied coating was exposed to a humid atmosphere of 95% RH (relative humidity) in a heating cabinet at 70 ^° C. for 30 minutes in order to react the mixture with the NCO groups of the prepolymer for chain extension.

A viscous adhesive was made by dissolving a thermoplastic linear polyester urethane elastomer in a solvent mixture of approximately equal parts of tetrahydrofuran and methyl ethyl ketone, the Solids content of this solution was 20%. The urethane elastomer was a practically crosslinking-free commercial product, which by reacting 1 mole of a polyester with a terminal OH, an aliphatic glycol and a diphenyl diisocyanate prepared in such proportions became that virtually no unreacted isocyanate or hydroxyl groups remained. The one with it The solution obtained had a viscosity at room temperature of 2000 to 3000 cP, determined with a Brookfield viscometer.

The above solvent type adhesive was applied to the previously roughened surface a polyvinyl chloride shoe upper material painted on a fabric backing. 24 hours after The coating 30 was applied to the polyvinyl chloride material provided with the backing Seconds exposed to an infrared heat activation in a radiant heat activator, the thermal unit has been set to an output of 60%. The activated by heat, on a pad applied polyvinyl chloride material was with its adhesive-coated surface against the in correspondingly heat-activated adhesive coating pressed onto the block copolymer sole material. The point bonding was good. The resulting arrangement was used to complete the bond compressed. The peel strength (initial bond), determined by the peel test, was 25.97 to 34.65 N / cm. When the bond was tested after 7 days, the peel strength (peel binding wedge) was 78.27 N / cm and the break occurred in the block copolymer.

65 Example5

The procedure of Example 4 was repeated, this time instead of the block copolymer material a styrene / butadiene block copolymer rubber outsole material was used. The arrangement

tion had good initial tack, very good initial bond strength and a peel strength (peel bond strength) after 7 days of 67.60 N cm ^-1 . In this case, the break occurred in the polyvinyl chloride shoe upper placed on a pad.

Example 6

The prepolymers with terminal NCO indicated below were prepared by reaction of polyols with diphenylmethane diisocyanate in those given in Table II below NCO / OH ratios. The polyol for prepolymer 2 was a polycaprolactone a molecular weight of 2890 and a melting point of 56 ° C and the prepolymer was prepared by reacting the polyol with diphenylmethane diisocyanate in proportions such that an NCO / OH ratio of 1.75 was achieved. The polyol for prepolymer 3 was one OH terminated butanediol sebacate polyester having a molecular weight of 2000 and a melting point of 64 ° C and the prepolymer was prepared by reacting the polyol with diphenylmethane diisocyanate in such proportions that an NCO / OH ratio of 1.75 was achieved.

Test strips measuring 2.54 cm × 17.76 cm made from the materials given in Table II below were coated with the molten prepolymer at 80 to 90 ° C. to achieve a film thickness of 0.075 mm. After 15 minutes, measured from the order of the films, the strips were 15 minutes placed in an oven of 7O ⁰ C with an atmosphere of high humidity in order by the reaction of the NCO groups in the material of the film with the water chain extension to achieve. The strips were then activated by infrared heating in a conventional radiant heat activator (RHA) for a period of 30 seconds, with the heat unit of the activator set at 60% power.

Upon activation, the temperature of the films on the strips rose to 68-75 ° C. The activated strips were then paired as indicated in the table below and to complete of the bonds pressed, after which the joined strips cooled to room temperature and the achieved Bindings were tested. The results obtained in the tests are summarized in the table below.

Table II

Prepoly test Substrate Curing Activation conditions Point- Shear strength Peel strength Dead load merisat No. conditions time after d. d. RHA- bonding at the start (Peel strength) at No. Harden Setting (Initial binding) the! 6 day old 65.56 ⁰ C N / cm Bond N / cm

1 SBR sole SBR sole 15 minutes. 70 min. 30 sec. out 39.84 material material Steam at 60% draws 70 ° C 2 the same the same the same 5 hours the same the same 31.17 3 the same Vinyl- the same the same the same the same - Top part material 4th the same the same the same 23 hours the same the same 15.59 5 surfaces Vinyl- 15 min. 7O ⁰ C 0 min., 30 sec. the same 12.15 chlorinated Top part Steam at 60% Styrene, material Butadiene Styrene Block mixing polymer 6th the same the same the same 3 hours. the same the same 34.65 7th SBR sole SBR sole the same the same the same the same 31.17 material material 8th the same Vinyl- the same the same the same the same 20.78 WDerien-
material 9 Vinyl sole Vinyl- 15 minutes. 30 min. 30 sec. out 39.84 Top part 70 ° C at draws material Steam 60% 10 Styrene the same the same the same the same the same 31.17 Isopropyl Block mixing polymer 11th SBR sole SBR sole the same 5 days the same the same 43.32 material material

Rubber breakage

Vinyl breakage

Binder strips from Pattina

Styrene / butadiene / styrene block copolymer fraction

Break in the vinyl upper part

65.74

77.85 46.71

50.17

RF

0 cm per hour

RF CSP -

RF

60.55
115.91 RF
Theatrical Version 0 cm
per hour K) 103.80
41.52 Theatrical Version
RF 2.54 cm
per hour δ 09 266 38.06 RF - 34.60 PF - 86.50 Theatrical Version 2.54 cm
Per
Hours.

Example 7

A prepolymer with terminal NCO was made by reacting a butanediolariipate polyester with Terminal hydroxyl with a molecular weight of 2600 and a crystalline melting point of 49 ° C with diphenylmethane diisocyanate in proportions such that an NCO / OH ratio of 1.5 is achieved was produced. The prepolymer obtained in this way had a melting point of 54 ° C. and was at one Viscosity of 8000 cP at 100 ° C flowable. The prepolymer was mixed in a solvent from 4 Parts of methylene chloride and 1 part of toluene dissolved to form a solution having 60% by weight of solids Solution has a viscosity of 1500 cP.

The solution was in the form of 0.127 mm thick films on the previously roughened surface of a Shoe leather upper and on the surface of an outsole material made from a vulcanized synthetic butadiene / styrene copolymer rubber, and the coatings were dried The films were in an oven for 15 minutes at 70 ° C in a high atmosphere Exposed to moisture by reacting the moisture with the NCO groups of the polymer, a To achieve chain extension. After this treatment, the material of the films became tough and adhered firmly the surfaces and could be softened to a sticky state at temperatures of 65 ° C by adhering to similar adhesive surfaces. The films became one for 20 seconds Infrared heat activation in a Radiant Heat Activator subjected, the thermal unit on a Power of 55% has been set. The surfaces have been merged together and to complete the bond pressed. In the test after 7 days, the peel strength (peel bond strength) was 70.06 N / cm.

Example 8

A prepolymer solution was prepared as in Example 7, but based on 0.25% dimethylpiperazine on the weight of the prepolymer, contained The solution was in the form of a layer on leather and on one vulcanized synthetic butadiene / styrene copolymer rubber applied and the coatings were dried as in Example 7. Chain extension was accomplished by standing the films for 15 minutes at 85 ° C in an atmosphere with a relative humidity of only 18 to 20% to transform the films into a tough, firmly adhering state. Then the films were heat activated and the leather and the synthetic rubbers were combined and pressed as in Example 7. The peel strength (peel strength) after 7 days was 70.06 N / cm.

Example 9

A prepolymer with terminal NCO was prepared by reacting a polycaprolactone with a molecular weight of 2860 and a crystalline melting point of 54 ^° C. with diphenylmethane diisocyanate in proportions such that a free NCO content of 2.18% was achieved. The prepolymer was dissolved in toluene to form a solution with a solids content of 60% by weight. The solution had a viscosity of 1600 cP.

The solution was applied in the form of 0.127 mm thick films onto the previously roughened surface of a Underlayed polyvinyl chloride shoe upper material and on the surface of an outsole material, consisting of a styrene / butadiene / styrene block copolymer, applied. The applied films were in an oven for 30 minutes at 70 ° C in an atmosphere with a relative humidity 90% exposed to the reaction of moisture with the NCO groups of the prepolymer, To effect chain extension. After this treatment, the material of the coatings was tough and adhered firmly on the surfaces and could be made sticky at temperatures of 65 ° C Condition in which it adhered to similar adhesive bar surfaces. The coatings were placed in a radiant heat activator Subjected to infrared heat activation for 20 seconds with the thermal unit at a Power of 55% has been set. The surfaces have been merged together and to complete pressed into the binding. The test after 7 days showed that the peel strength (peel bond strength) was 73.96 N / cm fraud.

1 sheet of drawings

Claims (1)

Patent claims: 1. Process for the adhesive bonding of surfaces, in which one a) a prepolymer with terminal NCO is applied to the surface of a molded body (object), which prepolymer has been prepared by reacting a diisocyanate with a polymeric polyol in proportions such that an NCO / OH ratio is obtained that is within the range of 1, 25: 1 to 3.0: 1, which has a crystalline melting point within the range from 40 to 90 ⁰ C and a molecular weight within the range from 1000 to 10,000 and which has been converted into a flowable state, b) brings an active hydrogen atom-supplying compound with the prepolymer in contact to a To effect chain extension, and c) the upper layer treated with the chain lengthening agent is then softened by means of heat State against a compatible (compatible) surface with the first-mentioned Surface should be joined to create an adhesive bond, and this bond then cools, so that it changes into a hard, solid state