DE1086374B - Adhesive mixture based on diisocyanates or reaction products of polyesters and diisocyanates for bonding shoe parts - Google Patents

Description

It is known that shoe soles are produced by a simple and inexpensive process the shoes are glued. Here, nitrocellulose solutions have been used as the adhesive. But there shoe soles As substitute materials have increasingly been used, adhesives have been used on the Rubber base largely used in place of nitrocellulose solutions. Usually included these adhesives are a mixture of a natural or synthetic rubber with a resinous, modifying one or reinforcing additive. Such adhesives are used for gluing rather thin soles Women's shoes are satisfactory, but their adhesive strength for gluing heavy, e.g. B. in work shoes Soles used are not sufficient. That is, these adhesives are unable to work within the restricted, An adhesive bond of sufficient time available for the adhesive pressing of soles Form strength to hold the stiff and heavy soles to the bottom of the shoe. Also are the final bond of these adhesives is too weak to peel off under unfavorable conditions to prevent such soles from shoes.

Self-hardening or maturing or setting rubber-like adhesives for shoe parts, which are caused by the reaction a polyisocyanate with a polymeric polymer having a plurality of effective hydrogen groups Material, particularly polyester, obtained are known and have recently come to the fore since they have exceptional strength and toughness. However, their strength and toughness only develop afterwards a considerable amount of time in which the ripening or setting of such materials occurs. When using such materials would have to increase the duration of the press-glueing to an intolerable extent will. Furthermore, the property of self-hardening or tires means that the constituents of these materials are immediate must be mixed together before use. As a result of these disadvantages, polyisocyanate adhesives are so far little has been used in practice for gluing shoe soles.

In contrast, the invention aims to provide a self-curing To create isocyanate adhesive mixture that is stable for a fairly long period of time, which forms a strong adhesive bond in a short time during adhesive pressing and the final one. Adhesive connection is extraordinarily strong and resilient.

It has been found that a self-curing adhesive can be made that has a strong initial Forms an adhesive bond during adhesive pressing and its properties when it is applied to the soles of shoes and the like by adding a special blend of reinforcing fillers with one containing polyisocyanate reacted polyester, with a polyisocyanate and with an adhesive mixture based on

Diisocyanates]! or reaction products of polyesters and diisocyanates

for gluing shoe parts

Applicant:

B. B. Chemical Co.,

Boston, Mass. (V. St. A.)

Representative: Dipl.-Ing. A. Bohr, Dipl.-Ing, H. Bohr,

Dipl.-Ing. S. Staeger, Munich 5 _r Müllerstr. 31,

and Dr.-Ing. H. Fincke, Berlin-Liehterfelde,

Patent attorneys

Claimed priority:
V. St. v. America June 19, 1958

John Lincoln Perkins, Hingham, Mass.,
and Dewey Martin Holmberg, Canton, Mass.

(V. St. A.),
have been named as inventors

a tackiness enhancing resin is mixed. It was also found that the during storage the reinforcing fillers have difficulties in segregating the fillers and that caused by them Gelation of the adhesive through the addition of certain proportions of mineral known per se Fillers with different properties can be overcome.

The new adhesive is a two-part adhesive Adhesive the first part of which is manufactured to overcome resistance difficulties which cling to this first part. After mixing the first part of the adhesive with the second part results the adhesive is a very strong initial bond and an extremely tough, strong final one Adhesive connection, so that the adhesive is particularly suitable for gluing soles to shoes.

The basis of the first part of the adhesive is a polymer solution. Besides this polymer solution contains the first part of the adhesive is a mixture of one another coordinated mineral fillers that interact with the components of the polymer solution and as a result bring about special advantages.

The polymer solution contains the reaction product of a polyester and a polyisocyanate and a die Tackiness-increasing resin, which is preferably self-

009 569/415

3 4

is hardening. Many resin is acceptable for reaction with polyisocyanate. The word "epoxy-equivalent polyesters are known and commercially available" refers to the weight in grams of the borrowed. These polyesters are made by esterification and resin, which contains 1 g of epoxy. The polyepoxy resins polymerizing a dibasic or polybasic are glycidyl polyethers of a phenol with a variety of carboxylic acids or by esterifying and polymerizing 5 O Η groups, an alcohol with a variety of mixtures of these acids with a complementary OH group, or both substances. The polyepoxy resins most effective in the bi- or polyfunctional compound containing more than one adhesive mixture are alcoholic hydroxyl groups, or with mixtures made of such compounds which have a fairly low molecular weight. Suitable acids and a fairly large proportion of effective epoxy for the polyester-forming reaction are adipic acid containing io groups. The polyepoxides are complex, succinic acid, sebacic acid, maleic acid and azelaic resin-like materials and can acidic through the reaction. It is preferred here that the acids, on the one hand, are mostly or entirely truncated acids, which have a large number of OH groups. Phenols with a polyfunctional chlorohydrin, such as alcohols with a large number of OH groups, are e.g. B. epichlorohydrin and glycerol dichlorohydrin, her-ethylene glycol, propylene glycol, diethylene glycol, tri-15 are made. The amount of ethylene glycol, trimethylolpropane and butylene glycol in this reaction. The chlorohydrin used exceeds the molecular equiva- A preferred mixture of alcohols with a multiple of the phenolic material and can contain up to two numbers of OH groups for reaction with adipic acid times as many as the molecular equivalent of the contains from 95 to 99% of one two OH -Groups on- phenolic material. For example, 2 moles of epi-containing alcohol, e.g. B. butanediol or an ethylene 20 chlorohydrin with 1 mole of diphenylolpropane in the anglycol. From 1 to 5% of an alcohol with three OH entities of caustic alkalis are reacted, the groups such. B. trimethylolpropane, the two amounts of caustic material exceeding the amount, alcohols containing O Η groups can be added. which is necessary for the connection of the halogen of the epichlorohydrin to the production of polyester. When these substances are heated by heating the materials in a vacuum for a few hours at about 100 ° C., a resinous, complex, poly-long structure is formed, so that the meric material obtained during the reaction, both terminal epoxy and water, is removed. The final water content should be group and terminal primary hydroxyl groups as low as possible and preferably no more. A large number of O Η groups containing than 0.1 ° / ₀ . The acid and alcohols are phenols used to form these resins mixed together in proportions such that there is one other than diphenylolpropane, bisphenol, hydroquinone, substantial excess of hydroxyl groups over resorcinol and other materials. Complex epoxy acid groups exist, and the reaction can also be produced to the extent that phenols are continued with one until a product is formed whose hydroxyl multitude of OH groups are preferably formed with simpler polyepoxy groups and one of which is reacted. For example, glycerol or tri-hydroxyl number from about 30 to 140, preferably from 50 to 35, methylolpropane reacts to a simple polyepoxide up to 60, and has an acid number of 0 to 12. The fact that polyesters with two OH groups are then stolen are liquid or phenols that are easily retained by heat and are reacted with fairly low molecular plexer polyepoxy resins for the purpose of forming suitable softenable resins,
weight, which is preferably in the range of about 2500 to about 4000 Other tackiness enhancing resins are chlorinated. 40 polyphenyls including chlorinated biphenyl, chlorinated

The reaction of polyesters with the polyisocyanates terphenyls, and alkali-catalyzed, para-substituted ones

is carried out by mixing one or more poly-phenol aldehyde resins, such as. B. the resinous condensate

isocyanates with one or more polyesters and by a paratertiary butylphenol with at least one

heating the mixture until the reaction takes about an equivalent amount of formaldehyde,

is complete. The reacting material is then removed. The polyepoxy resins and the phenol-formaldehyde resins

chilled and chopped up. Arylene diisocyanates, such as 2,4-To- react with the isocyanates. However, it turned out-

luylene diisocyanate, 1,5-naphthalene diisocyanate, m-Phe- made that significantly better results with polyepoxy resins

nylene diisocyanate, ditolylene diisocyanate and diphenyl results can be achieved than with others that

methane-p, p'-diisocyanate, are preferred because of tackiness-increasing resins. Result in polyepoxy resins

aliphatic isocyanates difficulties due to not only better stickiness, but also greater

persist in their toxicity. However, there can be an aliphatic period of time during which the tackiness of the adhesive

Isocyanates, such as. B. hexamethylene diisocyanate or persists before the tire or setting or

Pentamethylene diisocyanate, takes place together with or in place of curing. After that, the polyepoxy resins strengthen

of arylene diisocyanate can be used if the adhesive bond is significant,

speaking caution is exercised. Suitable for the reaction of the 55 For the first part of the adhesive mixture

Isocyanate with the polyester are from about 0.9 to solvents are anhydrous, volatile, organic

about 1.4 moles of diisocyanate per mole of polyester are used. Solvents that do not work with the polyisocyanates

The stickiness-increasing component of the first react. Preferred solvents are ester and part of the adhesive is a resinous, with the polyester ketone solvent, such as. B. ethyl acetate, dewas-polyisocyanate reaction product compatible material, 60 sertes ethylene glycol monoethyl ether acetate, acetone and the ability to stick a film of the mixture he methyl ethyl ketone, and this solvent can increase, so that the adhesive in a short time one is over either depending on Solvents are used on their own or in a mixture with other adhesive bonding agents that extend over the entire surface,
forms. The preferred, the tackiness of the adhesive.It has been found that finely divided, mine-increasing resins are polyepoxy resins with hot melt fillers, which have a reinforcing effect, score in the range of about 20 to 110 ° C and with one such as calcium silicate, the initial bond strength substantially increase the epoxy equivalent weight of preferably about 225 to adhesive. An adhesive with 1025; however, resins with epoxy equivalent - a suitable proportion of reinforcing fillers by weight values up to about 2400 can be used if even stiff soles are adhered to the shoe floor without the incomplete setting or tire of the epoxy sole lifting off the shoe floor during the

Get the same result with the same adhesive, however, which does not contain this filler, increases the glue-pressing time by ten times must become. When calcium silicate is used as the sole filler, it causes the first part to gel of the adhesive within a fairly short period of time, so that the first part of the adhesive then does not can be mixed with the second part.

Surprisingly, gelling can be prevented by adding a very fine, fibrous, mineral Filler added to the first part of the adhesive together with the filler exerting the reinforcing effect will. Fibrous mineral fillers known per se, such as. B. fibrous magnesium silicate cause also that the adhesive can be spread out easier and better, although this filler, if it is used alone tends to secrete.

Additional, finely divided, known per se mineral Filler such as B. Kieselerdeaerogel or iron-free, flaky silica, caused together with the other fillers that the adhesive becomes liquid when shaken and then coagulates again. This effect is used to prevent a coating of adhesive from dripping off a surface, e.g. B. a shoe sole, especially desirable and does not cause any difficulties in pumping or spreading the adhesive. About that In addition, silica helps add strength to the adhesive.

The shelf life of the first part of the adhesive is ^{significantly increased by the addition of about 1} ₄ to about 5 percent by weight, preferably about 1 percent by weight, based on the weight of the polyester-polyisocyanate reaction product, of maleic acid or maleic anhydride. Maleic acid or maleic anhydride tends to prevent the viscosity from increasing and appears to improve the adhesion of the adhesive to materials that are difficult to bond.

The desired interaction of the polymers and the mineral fillers depends on the proportion correct use of the materials. The level of the tackiness enhancing resin should be are within the range of 5 to 25 parts, and preferably 7 to 15 parts per IQO parts of the reaction product of polyester and polyisocyanate, while the mineral filler from 30 to Make up 60 parts by weight per 100 parts of the reaction product of polyester and polyisocyanate should. In order to coordinate the above-described effects of the mineral fillers with one another, it is It is important that the proportions of these materials be within a fairly narrow range. The above mentioned 30 to 60 parts by weight of mineral fillers are composed of 15 to 35, preferably 25 parts by weight of finely divided Calcium silicate, from 10 to 25, preferably about 15 parts by weight of fibrous magnesium silicate and from 5 to 20, preferably 10 parts by weight of iron-free silica.

The second part of the adhesive is a solution in a non-reactive, volatile, organic solvent one or more polyisocyanates. A preferred polyisocyanate is polymethylene polyphenyl isocyanate from following formula:

NCO

NCO

CH, -

NCO

In this formula, η averages 3. Other polyisocyanates or diisocyanates can be used together with or in place of this material. Suitable isocyanates are triphenyl methane triisocyanate, bis (4-phenyl isocyanate-methylene), diphenyl methane diisocyanate and set isocyanates, such as. B. Tiiphenylurethan. Very desirable results are obtained including an improvement in the ability of tacking with blends in which the effective isocyanate is comprised of from 50 to 70 percent by weight polymethylene polyphenyl isocyanate and from 30 to 50 percent by weight bis (4-phenyl isocyanate) methylene or a set

ίο isocyanate.

The adhesive is mixed according to a known mixing process. The polyester-polyisocyanate reaction product is treated on a cold roller until it forms streaks, whereupon the reinforcing mineral Filler and the fibrous mineral filler are added and carefully rolled in. The rolled Mixture is then poured into a churning device containing a solvent, which is operated for so long until the rolled mixture is dissolved. Then the silica, the polyepoxy resin and the dibasic organic acid was added to the solution and carefully mixed into it. So that the glue itself suitable for gluing soles to shoes, the viscosity of the mixture is brought to a suitable value, which is preferably from about 10,000 to 11,650 centipoises.

The manufacture of the second part of the adhesive consists of dissolving the polyisocyanate in one Solvent. Usually the polyisocyanate is used with so much solvent that 10 percent by volume of the second part, based on the volume of the first part of the adhesive, are sufficient to achieve a maturation or. Trigger the setting process.

In the finished adhesive, a sufficient amount of the second part of the adhesive will mix with the first part mixed so that the adhesive is from about 5 to about 15 percent by weight, preferably from about 8 to about 12 percent by weight, based on the weight of the polyester-polyisocyanate reaction product of the first adhesive part, Contains polyisocyanate. Mixing causes the polyisocyanate of the second adhesive part to react triggered with the polyester-polyisocyanate reaction product of the first adhesive part. Further it appears that the polyisocyanate of the second part of the adhesive is on the reactive hydroxyl groups of the polyepoxide acts if polyepoxide has been used as the tackiness-increasing resin and brings about a ripening or setting or hardening of the polyepoxide. The reactions work at room temperature so slowly that the application and use of the adhesive within a period of 24 hours is not affected.

The mixture of both adhesive parts is applied to the sole and to the bottom of the shoe. The mixture is allowed to dry at room temperature for 2 to 24 hours and at a temperature of 37.8 ° C. for a maximum of 8 hours. Thereafter, the adhesive coating on the shoe bottom and the shoe sole to a temperature of about 65.6 are heated to 82.2 C ⁰ if the soles to be bonded within 2 to 4 hours after application of the adhesive. After the adhesive has dried for 24 hours, the temperature of the adhesive coating is brought to the sole and to the shoe bottom at from about 90.6 to about 115.6 ⁰ C. The sole is then pressed against the bottom of the shoe and held in engagement therewith under pressure for about 10 to 30 seconds. The pressing time depends on the stiffness of the sole and on the degree of curvature that the sole glued to the shoe must have.

Claims (6)

7 8 The following examples serve to facilitate the isocyanate, 25 parts by weight of a finely divided calcium Understanding of the invention, which does not, however, apply to the silicates, 15 parts by weight of a fibrous magnesium the examples given conditions, proportions or silicates, 10 parts by weight of iron-free silica and Materials is limited. 10 parts by weight of chlorinated terphenyl with an er- _. 5 softening point (ball and ring method) from 37.8 to Example 1 ₄₁₁ o _{c> a} refractive index of 1.663, a chlorine 100 parts by weight of a commercially available pro content of 60 ° / ₀ and a specific weight of duktes obtained by reacting 1.13 mol of 1.665 g, being the solvent for the mixture Toluylene diisocyanate with one mole of a terminal Hy- 240 parts by weight of ethyl acetate, polyester containing hydroxyl groups from adipic acid ίο 1 part by volume of the polymethylene mentioned in Example I and butylene glycol, which is a hydroxyl number polyphenyl isocyanate solution to 16 parts by volume of the of about 55 and whose acid number is 2, add the above solution, and the mixture is are rolled into strips in a roller. 25 Weight sticking of rubber soles on shoe uppers or on parts of finely divided calcium silicate are the shoe bottom made of leather according to the in Example I The reaction product located on the roller was slowly used as described in the procedure described. Here it turned out added, and the mixture is treated so long that the adhesive makes a strong bond until the calcium silicate is evenly distributed in it. formed. After a period of 48 hours were Then 15 pieces of fibrous magnesium are used to pull the shoe sole off the shoe upper silicate added slowly to the mixture and required in the 27.216 to 36.288 kg, with the leather des mixed in the same way. After a rolling time of 20 shoe upper and the shoe sole tore,
The mixture on the roller has about 10 minutes Temperature of about 79.4 to 87.8 ° C, whereupon Example III Mixture spread and for the purpose of dissolving same according to the procedure described in Example I is is cut into strips in a Kirnvoirichtung. a solution from the one used in this example 240 parts by weight of ethyl acetate are used in the reaction product, the fillers, the polyepoxy resin Device filled. For this purpose, 10 parts by weight and the solvent are prepared, namely are finely divided, flaky iron-free silica given. these ingredients mixed in the same proportions, Then the strips of the rolled mixture are long as indicated in Example I. sam in the In. a solvent mixture that is 51 parts by weight Liquid poured into the churning device and made up of 30 ethyl acetate and 5.5 parts by weight of orthodichlorobenzene solved. 7 parts by weight of polymethylene poly- a powdery glycidyl polyether polyepoxy resin, phenyl isocyanate and 3 parts by weight of diphenyl methane adds, which has a melting point of about 40 to 76 ° C, 4,4'-diisocyanate dissolved. 1 part by volume of this solution an epoxy equivalent weight value of about 450 up to 16 parts by volume of the solution of the isocyanate reaction 525 and an average molecular weight of 35 tion product added and carefully mixed, has about 900 to 1000. Then the mixture is applied 1 The mixture is applied to the surfaces to be glued added maleic acid and the mixing in a rubber sole and a leather shoe upper The churning device continued until a uniform spread and was allowed to stir for 3 hours at room temperature. Lump-free solution is created. Furthermore, the were dried. The adhesive coatings are then applied to a Mixture 25 parts by weight of ethyl acetate added to the 40 temperature of 82.2 ° C. The glue eiwies Viscosity of the mixture to about 10,000 centipoises makes an excellent tack adhesive. The upper part bring. with the sole is inserted in a sole glue press, 10 parts by weight of the polymethylene polyphenyliso- and the sole is pressed firmly against the upper, Cyanats are in a 51 parts by weight of ethyl acetone so that they adapt to the shape of the shoe upper. and 45 containing 5.5 parts by weight of orthodichlorobenzene. The one exerted on the sole when pressing the glue Solvent mixture dissolved. Pressure is held for 20 seconds. To 1 volume part of the solution of the polymethylene-poly- during this period the sole is already firmly attached to the shoe- phenyl isocyanate is linked to 16 parts by volume of the iso-shaft. After a waiting time of 48 hours The solution containing the cyanate reaction product was added and a force of 36.288 kg was used to pull off the sole carefully mixed. 50 of the shoe upper he required, and here it tore The mixture is applied to the surfaces to be bonded sole material,
a shoe sole made of polychloroprene and a shoe bottom made of leather painted on and for 4 hours with patent claims
Dried at room temperature. The adhesive coatings are then heated so that their temperature rises to 82.2 ° C. Adhesive mixture based on diisocyanates, and the shoe sole is pressed firmly against the polyester or reaction products with Diiso shoe bottom, so that it becomes one of the shoe bottom cyanates for gluing shoe parts, thereby taking on the appropriate shape. The shoe sole is characterized in that it is kept in engagement with the product of an acid number from 0 to 12 and a shoe bottom for 20 seconds under pressure in addition to the reaction. After this period of time, the polyester with a hydroxyl number of 30 to 140 remains in its position on the bottom of the shoe in firmly bonded resin with a diisocyanate in a ratio of approximately three. 0.9 to 1.4 moles of diisocyanate per mole of polyester resin, After 48 hours, about 5 to about 25% of the shoe sole was peeled off based on weight a force of 38.556 kg was required, namely the reaction product entered with the reaction in the event of a tearing of the shoe sole. 65 product compatible, increases stickiness . . Resin with a melting point of 20 to HO ⁰ C and Example 11 _{to about 5} <y _{o to 15} oy _oj based on the weight of the An adhesive is according to the reaction product in Example I, a polyisocyanate and about written process, namely from 100 parts 30 to about 60 ° / ₀ , based on the weight of the reac the reaction product of a polyester and a poly- 70 tion product, a mixture of minerals Contains fillers containing solution in a volatile organic solvent, wherein the mixture of fillers from about 10 to about 25 ° / _0, based on the weight of the reaction product, fibrous magnesium silicate, from about 15 to 35%, based on the weight of the reaction product, of finely divided calcium silicate and about 15 to 20%, based on the weight of the reaction product, of essentially iron-free silica. 2. Adhesive mixture according to claim 1, characterized in that the solution of the volatile organic solvent contains about ^x / ₄ to about 5%, based on the weight of the reaction product, a dibasic organic acid, such as maleic acid and maleic anhydride, and that it is used as Polyisocyanate contains an arylene polyisocyanate. 3. Adhesive mixture according to claim 1 and 2, characterized in that it is used as a polyisocyanate contains a polymethylene polyphenyl isocyanate. 4. Adhesive mixture according to claim 1, 2 and 3, characterized in that it is a glycidyl ether-polyepoxy resin as the resin or contains a resinous, chlorinated polyphenyl. 5. Adhesive mixture according to claim 1, 2 and 3, characterized in that it is an alkali-catalyzed resin as the resin Condensation product of one mole of a para-substituted phenol and about one mole contains a formaldehyde. 6 .. adhesive mixture according to claim 1 to 5, characterized in that it is a mixture of Arylene diisocyanate and polymethylene polyphenyl isocyanate contains in a weight ratio of about 50:50 to 30:70. Considered publications:
German Patent Nos. 853 483, 887 856,878 827; Lüttgen, "Die Technologie der Klebstoffe", 1953, pp. 22/23, 39; 1957, Teü 2, p. 109.