CA1270613A - Shoe having a midsole of polyurethane and a walking sole of elastomer - Google Patents
Shoe having a midsole of polyurethane and a walking sole of elastomerInfo
- Publication number
- CA1270613A CA1270613A CA000525880A CA525880A CA1270613A CA 1270613 A CA1270613 A CA 1270613A CA 000525880 A CA000525880 A CA 000525880A CA 525880 A CA525880 A CA 525880A CA 1270613 A CA1270613 A CA 1270613A
- Authority
- CA
- Canada
- Prior art keywords
- walking
- moulding
- die
- injection
- midsole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D35/00—Producing footwear
- B29D35/06—Producing footwear having soles or heels formed and joined on to preformed uppers using a moulding technique, e.g. by injection moulding, pressing and vulcanising
- B29D35/08—Producing footwear having soles or heels formed and joined on to preformed uppers using a moulding technique, e.g. by injection moulding, pressing and vulcanising having multilayered parts
- B29D35/081—Producing footwear having soles or heels formed and joined on to preformed uppers using a moulding technique, e.g. by injection moulding, pressing and vulcanising having multilayered parts by injection moulding
- B29D35/082—Producing footwear having soles or heels formed and joined on to preformed uppers using a moulding technique, e.g. by injection moulding, pressing and vulcanising having multilayered parts by injection moulding injecting first the outer sole part
-
- A—HUMAN NECESSITIES
- A43—FOOTWEAR
- A43B—CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR
- A43B13/00—Soles; Sole-and-heel integral units
- A43B13/02—Soles; Sole-and-heel integral units characterised by the material
- A43B13/12—Soles with several layers of different materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D35/00—Producing footwear
- B29D35/0009—Producing footwear by injection moulding; Apparatus therefor
- B29D35/0018—Moulds
- B29D35/0045—Sealing means for the mould cavity
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)
Abstract
ABSTRACT
A shoe has an injection-moulded midsole of polyurethane and an injection-moulded walking sole of elastomer. The midsole and walking sole are connected by chemical bonds between the isocyanate and reactive terminal groups of substances added to the elastomer.
In order to make the shoe, a catalyst is added to the polyol and isocyanate mixture which reacts to form polyurethane to influence the speed of reaction and substances having reactive terminal groups are added to the elastomer. The walking sole is formed and the mixture for the midsole is introduced into a space between the walking sole and an upper. The reaction speed of the mixture and the temperature of the elastomer are controlled so that the chemical bonds are formed. An apparatus for making the shoe has separate appliances for moulding the walking sole and the midsole.
A shoe has an injection-moulded midsole of polyurethane and an injection-moulded walking sole of elastomer. The midsole and walking sole are connected by chemical bonds between the isocyanate and reactive terminal groups of substances added to the elastomer.
In order to make the shoe, a catalyst is added to the polyol and isocyanate mixture which reacts to form polyurethane to influence the speed of reaction and substances having reactive terminal groups are added to the elastomer. The walking sole is formed and the mixture for the midsole is introduced into a space between the walking sole and an upper. The reaction speed of the mixture and the temperature of the elastomer are controlled so that the chemical bonds are formed. An apparatus for making the shoe has separate appliances for moulding the walking sole and the midsole.
Description
~27~
SHOE HAVING A MIDSOLE OF POLYURETHANE AND A WALKING
-SOLE OF ELASTOMER
The invention relates to a shoe having a midsole of polyurethane and a walking sole of elastomer, to a process for moulding such soles onto shoe uppers, and to an apparatus, including moulds for performing the process.
Shoes having a midsole of polyurethane and a walking sole likewise consisting of polyurethane are known (DE-PS 22 41 493). For their manufacture turntable arrangements are generally used which have a plurality of working stations having moulds.
Moulds comprise two lateral mould parts, a base die, a counter-die and a last.
Owing to the low viscosity of the polyurethane, it is necessary, in a first injection stage, to injection-mould the walking sole using the lateral mould parts, the base die and the counter-die in the following manner. The lateral mould parts, the base die and the counter-die initially define a mould cavity, the volume of which is larger than the volume of the walking sole. After the introduction of a mixture that reacts to form the walking sole, this defined volume is reduced to the volume of the walking sole.
. ~
;13 The counter-die is then replaced by the last having an attached upper to form a further mould cavity, the volume of which is larger than the volume of the midsole. After the introduction of the mixture to form the midsole, this volume is reduced to the volume of the midsole. The mixture for the walking sole and the mixture for the midsole are introduced, in this case, at two different working stations.
The mixtures for the walking sole and for the midsole that react to form polyurethane comprise substantially polyol and isocyanate and also chain extenders and catalysts and are adjusted by appropriate additives depending on the material properties required for the walking sole or midsole. A
walking sole should be scuff resistant, and a midsole should be flexible and have a porous structure.
The chemical reactions commence while the components for these mixtures are being mixed. The mixtures react in the injection-moulding dies to form the walking sole or midsole. During the reaction of the mixture for the midsole, simultaneously the midsole is moulded and the connection is formed with the shoe upper and the walking sole.
Owing to the chemical reactions occurring during mixing, precautions must be taken at these working stations in order that the appropriate amount of the mixtures can regularly be supplied to the appropriate ~L27C36~3 mould cavities without disrupting the operation (see, for example, DE-PS 20 62 008)~
In addition, owing to the very low viscosity of the mixtures that react to form polyurethane, special precautions must be taken, for there is a danger that material introduced directly may come out of the mould. For this purpose it is known so to design the injection moulding dies that a controlled ejection of the material is achieved (see DE-PS 20 22 118, DE-AS 2 048 596).
Shoes having a midsole of polyurethane and a walking sole of elastomer are known and are manufactured as follows:-1. Unit soles The elastomer sole is provided with an adhesive layer and glued to a foamed midsole.
SHOE HAVING A MIDSOLE OF POLYURETHANE AND A WALKING
-SOLE OF ELASTOMER
The invention relates to a shoe having a midsole of polyurethane and a walking sole of elastomer, to a process for moulding such soles onto shoe uppers, and to an apparatus, including moulds for performing the process.
Shoes having a midsole of polyurethane and a walking sole likewise consisting of polyurethane are known (DE-PS 22 41 493). For their manufacture turntable arrangements are generally used which have a plurality of working stations having moulds.
Moulds comprise two lateral mould parts, a base die, a counter-die and a last.
Owing to the low viscosity of the polyurethane, it is necessary, in a first injection stage, to injection-mould the walking sole using the lateral mould parts, the base die and the counter-die in the following manner. The lateral mould parts, the base die and the counter-die initially define a mould cavity, the volume of which is larger than the volume of the walking sole. After the introduction of a mixture that reacts to form the walking sole, this defined volume is reduced to the volume of the walking sole.
. ~
;13 The counter-die is then replaced by the last having an attached upper to form a further mould cavity, the volume of which is larger than the volume of the midsole. After the introduction of the mixture to form the midsole, this volume is reduced to the volume of the midsole. The mixture for the walking sole and the mixture for the midsole are introduced, in this case, at two different working stations.
The mixtures for the walking sole and for the midsole that react to form polyurethane comprise substantially polyol and isocyanate and also chain extenders and catalysts and are adjusted by appropriate additives depending on the material properties required for the walking sole or midsole. A
walking sole should be scuff resistant, and a midsole should be flexible and have a porous structure.
The chemical reactions commence while the components for these mixtures are being mixed. The mixtures react in the injection-moulding dies to form the walking sole or midsole. During the reaction of the mixture for the midsole, simultaneously the midsole is moulded and the connection is formed with the shoe upper and the walking sole.
Owing to the chemical reactions occurring during mixing, precautions must be taken at these working stations in order that the appropriate amount of the mixtures can regularly be supplied to the appropriate ~L27C36~3 mould cavities without disrupting the operation (see, for example, DE-PS 20 62 008)~
In addition, owing to the very low viscosity of the mixtures that react to form polyurethane, special precautions must be taken, for there is a danger that material introduced directly may come out of the mould. For this purpose it is known so to design the injection moulding dies that a controlled ejection of the material is achieved (see DE-PS 20 22 118, DE-AS 2 048 596).
Shoes having a midsole of polyurethane and a walking sole of elastomer are known and are manufactured as follows:-1. Unit soles The elastomer sole is provided with an adhesive layer and glued to a foamed midsole.
2. Direct soles The elastomer sole coated with adhesive isactivated by, for example, infrared light and then the midsole, is introduced as a connection between the upper and the elastomer sole.
These processes involve a high labour content and are time-consuming. The problems with regard to Q~
production technology are serious, however, since, for example, it is not possible to ensure that this adhesive layer is kept to a layer thickness of from 20 to 30 micrometers.
In those cases in which the adhesive layer is thicker, after the shoe has been subjected to some stress, adhesive tears occur in the adhesive layer which result in detachment of the walking sole from the midsoleO Corresponding problems occur if the adhesive layer is applied too thinly, since then a continous adhesive connection is not achieved, as a result of which the useful life of such shoes is also reduced.
In general, moulding a walking sole of elastomer onto a midsole moulded from polyurethane in the mould also fails. The pressures used during the processing of elastomers range from 200 to 500 bar. Under these pressures the midsoles would be so highly compressed that it would no longer be possible to achieve flexible midsoles (comfort soles). Such soles are generally manufactured from mixtures containing foaming agents.
Spraying on plasticised elastomer is also not possible because its processing temperatures lie in the range of from 140 to 230C and at these temperatures the structure of the previously moulded polyurethane midsoles would be destroyed.
The mixture which reacts to form polyurethane forms a matrix in which crystallites are embedded, the 6~3 temperature resistance being determined substantially by the chain extenders used. When using diamines as chain extenders, the melting temperature of the polyurethane is approximately 150C, while when using butanediols as chain extenders the melting temperature is approximately 130C.
If any of these melting points exceeded, the polyurethane softens and develops a greasy consistency so that it is not possible to achieve dimensional stability of the moulded sole of polyurethane. In addition, the moulded sole would still be exposed to the high processing pressures of the elastomer.
For these reasons, the known process which use mixtures that react to form polyurethane also fail if first the walking sole and then the midsole is manufactured (DE-PS 22 41 493).
It is an object of this invention to provide a shoe having a midsole of polyurethane and a walking sole of elastomer in which a durable connection is ensured between the midsole and the walking sole even under extreme conditions and a relatively long period of use.
Another object of this invention is to provide a process for moulding these soles onto shoe uppers.
~27a6~3 According to one apsect of this invention, there is provided a shoe having an injection-moulded midsole formed from polyurethane and an injection-moulded walking sole formed from elastomer, in which the midsole and the walking sole are connected to each other in the region of their interface by chemical bonds between isocyanate and reactive terminal groups of substances added to the elatomer.
In contrast to the prior art, an adhesive layer - is not used. On the contrary, during manufacture, an interface is produced between the elastomer and the mixture that reacts to form polyurethane, and the chemical bonds are formed between the isocyanate and the elastomer in this interface. Surprisingly, it has been shown that in this manner a very durable connection is produced between the walking sole and the midsole which resists extreme stresses.
According to another apsect of this invention, there is provided a process for moulding soles onto shoe uppers, the soles comprising a midsole formed from polyurethane and a walking sole formed from elastomer, said process comprising adding at least one catalyst to the mixture which reacts to form polyurethane and contains polyol and isocyanate in order to influence the reaction speed of the mixture, adding to the elastomer substances which have reactive terminal groups forming chemical bonds with the isocyanate, forming the walking sole, introducing the mixture for ~27~613 the midsole into an intermediate space between the walking sole and the shoe upper~ and controlling the reaction speed for the formation of the polyurethane and the temperature of the elastomer so that chemical bonds are formed in the region of the interface between the elastomer and the reacting mixture.
AS mixtures of polyol and isocyanate which react to form polyurethane, there may be used mixtures based on ether and ester polyols, and containing per 100 parts by weight of polyol:
30 to 100 parts by weight of isocyanate 0.1 to 10 parts by weight of catalyst with the remainder comprising chain extenders and other customary additives.
As catalyst there may be used any catalyst commercially available under the tradename of the firm AIR PRODUCTS, such as, for example, DABCO-SB, or any other catalyst, for example, dibutyltin dilaurate.
As elastomers there may be used elastomers which are known for rubber soles and these can be mixed with the chemical compounds or chemical substances listed below in a proportion of from 0 to 20 parts for each 100 parts of rubber.
Examples of these elastomers are acrylonitrile rubber, styrene-butadiene rubber, natural rubber, and 7C~6~3 chloroprene rubber.
For the manufacture of a rubber walking sole by this process, all rubber qualities known as suitable for such a sole may be used when mixed with appropriate substances. The substances are mixed with the rubber in an amount of from 0 to 20 parts per 100 parts of rubber used.
The following substances are listed by way of example:
phenolformaldehyde resins, for example those supplied under the trademarks Vulkadur A (Bayer AG), Coretack ~BASF); methylolised phenolformaldehyde resins, for example those supplied under the trademarks ~P 1045 (Krahn), Korever (BASF~; resorcin in combination with a formaldehyde dispenser for example those supplied under the trademarks Cohedur A, Cohedur RS or RK (Bayer A~); silica fillers, for example those supplied under the trademarks Vulkasil S (Bayer AG); Ultrasil (Degussa); an amino-alcohol, for example 3-aminopropanol; a primary or secondary amine, for example stearylamine; polyvinyl alcohol, for example those supplied under the trademarks Mowiwol (Hoechst) or VSH 72 or VSH 73 having a viscosity in the range of from 1000 to 10000 CP 10~ aqueous mixture at 25C from the firm AIR PRODUCTS; a polyol containing a high number of hydro~y groups, for example those supplied under the trademarks Formrez ~Witco), acrylats rubber (ACM), Hydrin (Polysar), Herclor (Hercules); a combination of the above-mentioned substances.
Conveniently, a walking sole is formed by injection-moulding at the customary processing temperatures from these plasticised elastomers using an in~ection-moulding machine.
Desirably, the temperature of the elastomer is controlled so that the temperature of the in;ection-moulded walking sole is cooled to below the decomposition temperature of the polyurethane of the midsole to be formed and only then is the mixture that reacts to ~Z7(~613 form polyurethane brought into contact with the moulded walking sole. The isocyanate then reacts with reactive terminal groups in an interface layer at the parting plane and interface of the elastomer and polyurethane.
When controlling the temperature of the elastomer use may be made of the fact that a temperature increase or reduction of 10C
results in a shortening or lengthening, respectively, of the vulcanisation time, that is to say the time until the elastomer has completely reacted, of 50%.
In theory, the precess may be so carried out that the entire in~ection-moulded walking sole is cooled to a temperature below the decomposition 6~3 temperature of the polyurethane and then the midsole is moulded. A prerequisite is that this cooling period is sufficiently short so that the elastomer is still not vulcanised in order that the isocyanate can react with the reactive terminal groups to form a durable connection of the walking sole with the midsole.
Disregarding relatively long cooling times, only a limited selection of elastomers could be used to achieve this.
A further problem can occur during the processing of mixtures which, when reacting, foam considerably and create a relatively high pressure owing to a high proportion of foaming agent. In these cases, it is not readily possible to ensure that when the mixture is introduced it does not at least partially penetrate the walking sole that is not yet vulcanised.
Advantageously therefore, before the introduction of the mixture that reacts to form polyurethane, the walking sole is cooled in the region of the interface to be formed with the polyurethane and is heated in the region of the walking surface, the average temperature of the walking sole during and after the introduction of the mixture being maintained at a temperature below the decomposition temperature of the polyurethane.
Since the working temperatures and working pressures for processing elastomers to be plasticised and for processing the mixtures that react to form polyurethane are different, known apparatus cannot be used for moulding soles according to the process of the invention.
~7~613 A further object of this invention is therefore to provide an apparatus for moulding soles onto shoe uppers according to the process of the invention as set out above, that is for manufacturing a shoe according to this process.
According to a further aspect of this invention, there is provided an apparatus for performing the process set out above, said apparatus including at least one appliance which operates as an injection-moulding machine for plasticising the polymer andforming walking soles by injection-moulding, and at least one appliance which operates as a shoe-soling machine for processing polyurethane for moulding midsoles and for connecting the midsoles to walking soles and shoe uppers.
This apparatus permits a shoe to be manufactured and the process to be performed while taking account of these different processing temperatures and different working pressures.
Conveniently, the or each appliance for forming the walking sole includes at least one injection-moulding die, one half of the die being arranged as a plate and having a feed bore and the other half of the die having a cavity for forming a walking sole, the appliance being arranged so that the half of the die having the cavity for the walking sole can be moved pivotally after forming a walking sole by injection moulding and opening the injection-moulding die, and the or each appliance for moulding the midsole includes two lateral mould parts and a last for attaching shoe uppers, the appliance being arranged so that the two lateral mould parts can be brought into engagement with the pivoted die half having the walking sole cavity and the last together with an attached upper in order to form a mould cavity for moulding a midsole.
In one arrangement, the appliance for injection-moulding the walking sole has a plurality of die halveshaving a cavity for a walking sole and a support member that can be pivoted about an axis, on each of the side faces of which parallel to the axis there is arranged one of the die halves.
With this arrangement, it is possible after starting the apparatus to manufacture at each working station at any one time both a walking sole and a midsole.
The invention will now be described, in more detail, by way of example with reference to the drawings in which:
Figure 1 is a diagrammatic cross-sectional view of part of an apparatus according to one embodiment of this invention;
Figure la is a cross-sectional view, in a plane at 90 to the plane of Figure 1, showing a modification to a mould-clamping plate of the apparatus of Figure l;
Figure 2 is a diagrammatic cross-sectional view of the apparatus of Figure l;
Figure 3 is a diagrammatic cross-sectional view of the apparatus of Figure 1 with the injection-moulding die in an open position;
Figure 4a is a cross-sectional view of an injection moulding die forming part of an apparatus according to a second embodiment of this invention;
Figure 4b i5 a cross-sectional view of part of the apparatus according to said second embodiment;
Figure 5 shows an injection-moulding installation for performing the process according to this invention; and Figure 6 is a perspective view of a shoe embodying this invention.
Referring now to Figure 1 and 2, there is shown an apparatus embodying this invention. In Figure 1, only part of the apparatus is shown and the apparatus is shown more completely in Figure 2.. The same reference numerals are used in Figures 1 and 2.
Referring now especially to Figure 1, the apparatus includes a mould-clamping plate 1. As shown in Figure 2, the plate 1 is displaceably mounted on rails 17. One die half 2 of a die 3 for the manufacture of elastomer soles is clamped onto the mould-clamping plate 1. The die half 2 is plate shaped. The die 3 is shown in its closed position in Figure 1.
The second die half 4 of the injection-moulding die 3 is clamped on a displaceable and pivotable mould-clamping plate or support member 5. The mould-clamping plate 5 is shown in greater detail in Figure 2. As shown in Figure 2, the plate 5 is also guided on rails 17 and can be pivotal about an axis which is perpendicular to the rails 17. Referring back to Figure 1, the displaceable and pivotable mould-clamping plate 5 has a further die half 4 on i~s side remote from the die 3. After pivoting the plate 5 through 1~0, this further die half 4 forms with the die half 2, with the two die halves in their closed ~.27(~613 position, an injection moulding die 3 for the manufacture of a walking sole.
Each of the die halves 4 has a mould cavity 6 which together with the die half 2 defines, in the closed position of the injection-moulding die 3, the mould cavity for the walking sole.
The die half 2 has a discharge channel 9 having an injection bore 8. The injection bore 8 runs perpendicular to the direction of movement of the displaceable mould-clamping plate 1, while the discharge channel 9 runs parallel to the direction of movement of the displaceable mould-clamping plate 1 and emerges from the surface of the die half 2 in such a manner that the aperture opens into the mould cavity of the die half 4.
In the closed position of the injection-moulding die 3, the injection bore 8 engages with a plasticising and injection unit for elastomers (not shown) and plasticised elastomer material having the composition according to the invention is injected for moulding the walking sole vla the discharge channel 9. The die half 2 has cooling channels 10 and the die half 4 has heatiny channels 11. A coolant flows through the cooling channels 10 and a heated medium flows through the heating channels 11. The operating temperatures can be so selected that in the plane of contact of the two ~7~
die halves the walking sole vulcanises more 510wly than in the region of the walking surface.
By adjusting the flow rate and the temperature for the coolant and the heating medium it is possible to achieve an appropriate temperature distribution in the closed injection-moulding die 3 so that the plasticisd elastomer in the die half 4 in the region of the walking surface of the walking sole vulcanises rapidly while the interface layer of the walking sole which is in contact with the die half 2 vulcanises only after the injection of the material for the midsole.
After the injection of the elastomer material for the walking sole, the injection-moulding die 3 is opened, as described below. The displaceable and pivotable mould-clamping plate 5 is then pivoted through 180 so that, together with the injection-moulded walking sole designated 6', it adopts the position shown in Fig. 1, while the die half 4, which was in the upper position, is pivoted downwards.
The die half 4 that is now in the upper positlon cooperates with two lateral mould parts 12 and 13 and a last 14 having an attached shoe upper 15 to mould the midsole 16' from a mixture that reacts to form polyurethane and has the composition according to the invention.
In the closed position, the lateral mould parts 12, 13 define in a manner known Per se a feed 3L;~7~J~
channel that is symmetrical with respect of their plane of contact for injecting the mixture that foams to form polyurethane and has the composition according to the invention.
The lateral mould parts 12, 13, the last 14 having the attached upper 15 and the die half 4 define the mould cavity 16 which has the volume of the midsole 16'. When processing mixtures that react to form polyurethane, the known problem occurs that the mixture, owing to its low viscosity, prevents the moulding of separate layers, unless a controlled injection of material occurs. For this purpose, the lateral moulding parts 12 and 13 have an undercut 18 directed in each case towards the walking sole.
When introducing the mixture, to which a foaming agent is added for the formation of a flexible midsole, the mixture reacts and foams, thereby expanding into the region of the undercuts 18. After the finished shoe has been removed from the mould, the sole is cut to size perpendicular to the undercuts so that a clean parting line is formed between the midso e 16' and the walking sole 6'.
Referring to Figure la, there is shown a modification in which the mould-clamping plate 5 takes the form of a support member 5 having a four-sided, specifically square, cross-section. An individual die half 4 is mounted on each side of support member 5.
Referring now to Figure 2, the apparatus has four rails 17 l Z~6~3 which with two column plates 30 and 19 form a machine framework. There is guided on the rails 17, of which only two are visible, the displaceable mould-clamping plate 1. On its side remote from the die half 2 it has a locking unit known E~ se and designated 20 which in the simplest case is, for example, a knee lever joint that can be actuated by a cylinder or has at least one driving cylinder and at least one mould-locking cylinder of known design.
The displaceable mould-clamping plate 1 guides two displaceable rails 21 at the free ends of which there is pivotally mounted the displaceable and pivotable mould-clamping plate 5.
The mould-clamping plate 5 is arranged on the rails 21 so that it can be displaced in the direction towards the mould-clamping plate 1 by means of cylinders (not shown) .
In Fig. 2 the injection-moulding die 3 is shown in its closed position.
In this closed position of the injection-moulding die 3, the displaceable and pivotable support member 5 rests against the column plate 19.
The column plate 19 has an aperture 22, into which the die half 4 having a walking sole extends and cooperates with the lateral mould parts 12 and 13 and with the last 14 having the attached upper 15.
In Fig. 2 the two lateral mould parts 12, 13 6~3 are, corresponding to Fig. 1, in their closed position and de~ine with the last 14 having the attached upper 15 the mould cavity 16 for moulding the midsole 16'.
In the position shown in Fig. 2, when the mould
These processes involve a high labour content and are time-consuming. The problems with regard to Q~
production technology are serious, however, since, for example, it is not possible to ensure that this adhesive layer is kept to a layer thickness of from 20 to 30 micrometers.
In those cases in which the adhesive layer is thicker, after the shoe has been subjected to some stress, adhesive tears occur in the adhesive layer which result in detachment of the walking sole from the midsoleO Corresponding problems occur if the adhesive layer is applied too thinly, since then a continous adhesive connection is not achieved, as a result of which the useful life of such shoes is also reduced.
In general, moulding a walking sole of elastomer onto a midsole moulded from polyurethane in the mould also fails. The pressures used during the processing of elastomers range from 200 to 500 bar. Under these pressures the midsoles would be so highly compressed that it would no longer be possible to achieve flexible midsoles (comfort soles). Such soles are generally manufactured from mixtures containing foaming agents.
Spraying on plasticised elastomer is also not possible because its processing temperatures lie in the range of from 140 to 230C and at these temperatures the structure of the previously moulded polyurethane midsoles would be destroyed.
The mixture which reacts to form polyurethane forms a matrix in which crystallites are embedded, the 6~3 temperature resistance being determined substantially by the chain extenders used. When using diamines as chain extenders, the melting temperature of the polyurethane is approximately 150C, while when using butanediols as chain extenders the melting temperature is approximately 130C.
If any of these melting points exceeded, the polyurethane softens and develops a greasy consistency so that it is not possible to achieve dimensional stability of the moulded sole of polyurethane. In addition, the moulded sole would still be exposed to the high processing pressures of the elastomer.
For these reasons, the known process which use mixtures that react to form polyurethane also fail if first the walking sole and then the midsole is manufactured (DE-PS 22 41 493).
It is an object of this invention to provide a shoe having a midsole of polyurethane and a walking sole of elastomer in which a durable connection is ensured between the midsole and the walking sole even under extreme conditions and a relatively long period of use.
Another object of this invention is to provide a process for moulding these soles onto shoe uppers.
~27a6~3 According to one apsect of this invention, there is provided a shoe having an injection-moulded midsole formed from polyurethane and an injection-moulded walking sole formed from elastomer, in which the midsole and the walking sole are connected to each other in the region of their interface by chemical bonds between isocyanate and reactive terminal groups of substances added to the elatomer.
In contrast to the prior art, an adhesive layer - is not used. On the contrary, during manufacture, an interface is produced between the elastomer and the mixture that reacts to form polyurethane, and the chemical bonds are formed between the isocyanate and the elastomer in this interface. Surprisingly, it has been shown that in this manner a very durable connection is produced between the walking sole and the midsole which resists extreme stresses.
According to another apsect of this invention, there is provided a process for moulding soles onto shoe uppers, the soles comprising a midsole formed from polyurethane and a walking sole formed from elastomer, said process comprising adding at least one catalyst to the mixture which reacts to form polyurethane and contains polyol and isocyanate in order to influence the reaction speed of the mixture, adding to the elastomer substances which have reactive terminal groups forming chemical bonds with the isocyanate, forming the walking sole, introducing the mixture for ~27~613 the midsole into an intermediate space between the walking sole and the shoe upper~ and controlling the reaction speed for the formation of the polyurethane and the temperature of the elastomer so that chemical bonds are formed in the region of the interface between the elastomer and the reacting mixture.
AS mixtures of polyol and isocyanate which react to form polyurethane, there may be used mixtures based on ether and ester polyols, and containing per 100 parts by weight of polyol:
30 to 100 parts by weight of isocyanate 0.1 to 10 parts by weight of catalyst with the remainder comprising chain extenders and other customary additives.
As catalyst there may be used any catalyst commercially available under the tradename of the firm AIR PRODUCTS, such as, for example, DABCO-SB, or any other catalyst, for example, dibutyltin dilaurate.
As elastomers there may be used elastomers which are known for rubber soles and these can be mixed with the chemical compounds or chemical substances listed below in a proportion of from 0 to 20 parts for each 100 parts of rubber.
Examples of these elastomers are acrylonitrile rubber, styrene-butadiene rubber, natural rubber, and 7C~6~3 chloroprene rubber.
For the manufacture of a rubber walking sole by this process, all rubber qualities known as suitable for such a sole may be used when mixed with appropriate substances. The substances are mixed with the rubber in an amount of from 0 to 20 parts per 100 parts of rubber used.
The following substances are listed by way of example:
phenolformaldehyde resins, for example those supplied under the trademarks Vulkadur A (Bayer AG), Coretack ~BASF); methylolised phenolformaldehyde resins, for example those supplied under the trademarks ~P 1045 (Krahn), Korever (BASF~; resorcin in combination with a formaldehyde dispenser for example those supplied under the trademarks Cohedur A, Cohedur RS or RK (Bayer A~); silica fillers, for example those supplied under the trademarks Vulkasil S (Bayer AG); Ultrasil (Degussa); an amino-alcohol, for example 3-aminopropanol; a primary or secondary amine, for example stearylamine; polyvinyl alcohol, for example those supplied under the trademarks Mowiwol (Hoechst) or VSH 72 or VSH 73 having a viscosity in the range of from 1000 to 10000 CP 10~ aqueous mixture at 25C from the firm AIR PRODUCTS; a polyol containing a high number of hydro~y groups, for example those supplied under the trademarks Formrez ~Witco), acrylats rubber (ACM), Hydrin (Polysar), Herclor (Hercules); a combination of the above-mentioned substances.
Conveniently, a walking sole is formed by injection-moulding at the customary processing temperatures from these plasticised elastomers using an in~ection-moulding machine.
Desirably, the temperature of the elastomer is controlled so that the temperature of the in;ection-moulded walking sole is cooled to below the decomposition temperature of the polyurethane of the midsole to be formed and only then is the mixture that reacts to ~Z7(~613 form polyurethane brought into contact with the moulded walking sole. The isocyanate then reacts with reactive terminal groups in an interface layer at the parting plane and interface of the elastomer and polyurethane.
When controlling the temperature of the elastomer use may be made of the fact that a temperature increase or reduction of 10C
results in a shortening or lengthening, respectively, of the vulcanisation time, that is to say the time until the elastomer has completely reacted, of 50%.
In theory, the precess may be so carried out that the entire in~ection-moulded walking sole is cooled to a temperature below the decomposition 6~3 temperature of the polyurethane and then the midsole is moulded. A prerequisite is that this cooling period is sufficiently short so that the elastomer is still not vulcanised in order that the isocyanate can react with the reactive terminal groups to form a durable connection of the walking sole with the midsole.
Disregarding relatively long cooling times, only a limited selection of elastomers could be used to achieve this.
A further problem can occur during the processing of mixtures which, when reacting, foam considerably and create a relatively high pressure owing to a high proportion of foaming agent. In these cases, it is not readily possible to ensure that when the mixture is introduced it does not at least partially penetrate the walking sole that is not yet vulcanised.
Advantageously therefore, before the introduction of the mixture that reacts to form polyurethane, the walking sole is cooled in the region of the interface to be formed with the polyurethane and is heated in the region of the walking surface, the average temperature of the walking sole during and after the introduction of the mixture being maintained at a temperature below the decomposition temperature of the polyurethane.
Since the working temperatures and working pressures for processing elastomers to be plasticised and for processing the mixtures that react to form polyurethane are different, known apparatus cannot be used for moulding soles according to the process of the invention.
~7~613 A further object of this invention is therefore to provide an apparatus for moulding soles onto shoe uppers according to the process of the invention as set out above, that is for manufacturing a shoe according to this process.
According to a further aspect of this invention, there is provided an apparatus for performing the process set out above, said apparatus including at least one appliance which operates as an injection-moulding machine for plasticising the polymer andforming walking soles by injection-moulding, and at least one appliance which operates as a shoe-soling machine for processing polyurethane for moulding midsoles and for connecting the midsoles to walking soles and shoe uppers.
This apparatus permits a shoe to be manufactured and the process to be performed while taking account of these different processing temperatures and different working pressures.
Conveniently, the or each appliance for forming the walking sole includes at least one injection-moulding die, one half of the die being arranged as a plate and having a feed bore and the other half of the die having a cavity for forming a walking sole, the appliance being arranged so that the half of the die having the cavity for the walking sole can be moved pivotally after forming a walking sole by injection moulding and opening the injection-moulding die, and the or each appliance for moulding the midsole includes two lateral mould parts and a last for attaching shoe uppers, the appliance being arranged so that the two lateral mould parts can be brought into engagement with the pivoted die half having the walking sole cavity and the last together with an attached upper in order to form a mould cavity for moulding a midsole.
In one arrangement, the appliance for injection-moulding the walking sole has a plurality of die halveshaving a cavity for a walking sole and a support member that can be pivoted about an axis, on each of the side faces of which parallel to the axis there is arranged one of the die halves.
With this arrangement, it is possible after starting the apparatus to manufacture at each working station at any one time both a walking sole and a midsole.
The invention will now be described, in more detail, by way of example with reference to the drawings in which:
Figure 1 is a diagrammatic cross-sectional view of part of an apparatus according to one embodiment of this invention;
Figure la is a cross-sectional view, in a plane at 90 to the plane of Figure 1, showing a modification to a mould-clamping plate of the apparatus of Figure l;
Figure 2 is a diagrammatic cross-sectional view of the apparatus of Figure l;
Figure 3 is a diagrammatic cross-sectional view of the apparatus of Figure 1 with the injection-moulding die in an open position;
Figure 4a is a cross-sectional view of an injection moulding die forming part of an apparatus according to a second embodiment of this invention;
Figure 4b i5 a cross-sectional view of part of the apparatus according to said second embodiment;
Figure 5 shows an injection-moulding installation for performing the process according to this invention; and Figure 6 is a perspective view of a shoe embodying this invention.
Referring now to Figure 1 and 2, there is shown an apparatus embodying this invention. In Figure 1, only part of the apparatus is shown and the apparatus is shown more completely in Figure 2.. The same reference numerals are used in Figures 1 and 2.
Referring now especially to Figure 1, the apparatus includes a mould-clamping plate 1. As shown in Figure 2, the plate 1 is displaceably mounted on rails 17. One die half 2 of a die 3 for the manufacture of elastomer soles is clamped onto the mould-clamping plate 1. The die half 2 is plate shaped. The die 3 is shown in its closed position in Figure 1.
The second die half 4 of the injection-moulding die 3 is clamped on a displaceable and pivotable mould-clamping plate or support member 5. The mould-clamping plate 5 is shown in greater detail in Figure 2. As shown in Figure 2, the plate 5 is also guided on rails 17 and can be pivotal about an axis which is perpendicular to the rails 17. Referring back to Figure 1, the displaceable and pivotable mould-clamping plate 5 has a further die half 4 on i~s side remote from the die 3. After pivoting the plate 5 through 1~0, this further die half 4 forms with the die half 2, with the two die halves in their closed ~.27(~613 position, an injection moulding die 3 for the manufacture of a walking sole.
Each of the die halves 4 has a mould cavity 6 which together with the die half 2 defines, in the closed position of the injection-moulding die 3, the mould cavity for the walking sole.
The die half 2 has a discharge channel 9 having an injection bore 8. The injection bore 8 runs perpendicular to the direction of movement of the displaceable mould-clamping plate 1, while the discharge channel 9 runs parallel to the direction of movement of the displaceable mould-clamping plate 1 and emerges from the surface of the die half 2 in such a manner that the aperture opens into the mould cavity of the die half 4.
In the closed position of the injection-moulding die 3, the injection bore 8 engages with a plasticising and injection unit for elastomers (not shown) and plasticised elastomer material having the composition according to the invention is injected for moulding the walking sole vla the discharge channel 9. The die half 2 has cooling channels 10 and the die half 4 has heatiny channels 11. A coolant flows through the cooling channels 10 and a heated medium flows through the heating channels 11. The operating temperatures can be so selected that in the plane of contact of the two ~7~
die halves the walking sole vulcanises more 510wly than in the region of the walking surface.
By adjusting the flow rate and the temperature for the coolant and the heating medium it is possible to achieve an appropriate temperature distribution in the closed injection-moulding die 3 so that the plasticisd elastomer in the die half 4 in the region of the walking surface of the walking sole vulcanises rapidly while the interface layer of the walking sole which is in contact with the die half 2 vulcanises only after the injection of the material for the midsole.
After the injection of the elastomer material for the walking sole, the injection-moulding die 3 is opened, as described below. The displaceable and pivotable mould-clamping plate 5 is then pivoted through 180 so that, together with the injection-moulded walking sole designated 6', it adopts the position shown in Fig. 1, while the die half 4, which was in the upper position, is pivoted downwards.
The die half 4 that is now in the upper positlon cooperates with two lateral mould parts 12 and 13 and a last 14 having an attached shoe upper 15 to mould the midsole 16' from a mixture that reacts to form polyurethane and has the composition according to the invention.
In the closed position, the lateral mould parts 12, 13 define in a manner known Per se a feed 3L;~7~J~
channel that is symmetrical with respect of their plane of contact for injecting the mixture that foams to form polyurethane and has the composition according to the invention.
The lateral mould parts 12, 13, the last 14 having the attached upper 15 and the die half 4 define the mould cavity 16 which has the volume of the midsole 16'. When processing mixtures that react to form polyurethane, the known problem occurs that the mixture, owing to its low viscosity, prevents the moulding of separate layers, unless a controlled injection of material occurs. For this purpose, the lateral moulding parts 12 and 13 have an undercut 18 directed in each case towards the walking sole.
When introducing the mixture, to which a foaming agent is added for the formation of a flexible midsole, the mixture reacts and foams, thereby expanding into the region of the undercuts 18. After the finished shoe has been removed from the mould, the sole is cut to size perpendicular to the undercuts so that a clean parting line is formed between the midso e 16' and the walking sole 6'.
Referring to Figure la, there is shown a modification in which the mould-clamping plate 5 takes the form of a support member 5 having a four-sided, specifically square, cross-section. An individual die half 4 is mounted on each side of support member 5.
Referring now to Figure 2, the apparatus has four rails 17 l Z~6~3 which with two column plates 30 and 19 form a machine framework. There is guided on the rails 17, of which only two are visible, the displaceable mould-clamping plate 1. On its side remote from the die half 2 it has a locking unit known E~ se and designated 20 which in the simplest case is, for example, a knee lever joint that can be actuated by a cylinder or has at least one driving cylinder and at least one mould-locking cylinder of known design.
The displaceable mould-clamping plate 1 guides two displaceable rails 21 at the free ends of which there is pivotally mounted the displaceable and pivotable mould-clamping plate 5.
The mould-clamping plate 5 is arranged on the rails 21 so that it can be displaced in the direction towards the mould-clamping plate 1 by means of cylinders (not shown) .
In Fig. 2 the injection-moulding die 3 is shown in its closed position.
In this closed position of the injection-moulding die 3, the displaceable and pivotable support member 5 rests against the column plate 19.
The column plate 19 has an aperture 22, into which the die half 4 having a walking sole extends and cooperates with the lateral mould parts 12 and 13 and with the last 14 having the attached upper 15.
In Fig. 2 the two lateral mould parts 12, 13 6~3 are, corresponding to Fig. 1, in their closed position and de~ine with the last 14 having the attached upper 15 the mould cavity 16 for moulding the midsole 16'.
In the position shown in Fig. 2, when the mould
3 is closed and after the mould cavity 6 has been formed, plasticised elastomer is injected into the closed mould 3 to form a walking sole 6' and there is fed into the mould cavity 16 a mixture that reacts to form polyuretnane while forming the midsole 16'. At the same time~isocyanate enters into chemical bonds with the reactive terminal groups of the, as yet unvulcanised, interface layer of the already moulded walking sole 6' (Fig. 1) to form a durable connection of the walking sole with the midsole 16'.
The closed position is then acted upon in such a manner that in the representation of Fig~ 2 the displaceable mould-clamping plate 1 moves downwards . At the same time,the cylinders (not shown) for the guide rails 21 are also actuated. As a result the injection-moulding die 3 is opened, that is to say the two die halves 2 and 4 disengage and at the same time the upper die half 4 disengages from the column plate 19. Fig. 3 shows the appar~u~ in ~his position. In this opened position, the mould-clamping plate 5 is pivoted so that now the lower die half 4 adopts the position of the upp~r die half 4. By appropriately actuating the working cylinder and the locking unit 20, ~2~06~3 the injection-moulding die 3 is closed. At the same time, a last 14 having an attached upper 15, on which the walking sole 6' and the midsole 16' are to be moulded, is arranged on the lateral mould parts brou~ht into their closed position. Subsequently, as explained above, the midsole 16' is moulded and simultaneously connected to the walking sole 6' and the shoe upper.
For the manufacture of walking soles, the known elastomers used hitherto can be used which, with appropriate substances, contain the reactive terminal groups and are mixed before the plasticisation.
Especially good results were obtained with the following mixture for the elastomers:
Embodiment 1 Perbunanan 2807 ~a Trademark) Bayer 100.0 stearic acid 1.0 cumarone resin 6.5 Vulkasil S (a Trademark) sayer 35.0 Ti2 5.0 MT carbon Black 0.5 triethanolamine 1.0 sulphur 1.5 MBT 0.4 DPG 0.20 Vulkalent E (a Trademark) Bayer 1.00 Cohedur RS (a Trademark) Bayer 2.25 Cohedur A (a Trademark) Bayer 4.00 Embodiment2 SBR 1712 (a Trademark) Chemie Huls 14.00 lf~71~613 CB 10 (a Trademark) Chemie Huls 43.30 Shenectady, SP 1045 (a Trademark) Shenectady6.33 SMR 5 L (a Trademark) 6.33 Aflux 42 (a Trademark) Rheinchemie 2.00 Ultrasil VN3 (a trademark) Degussa 20.00 Aktivator X 50 S (a Trademark) Degussa 2.00 ZnO 2.65 sulpher 1.73 DOTG 1.73 Embodiment 3 SBR 1500 (a Trademark) Chemie Huls 100.00 stearic acid 1.00 cumarone resin 5.00 Vulkasil S (a Trademark) Bayer 35.00 TiO2 5.00 MT carbon black 0.50 triethanolamine 1.00 sulphur 0.35 Rhenocure S (a Trademark) Rheinchemie 1.50 MOZ 1.30 MBT 0.60 TMTD 0.20 Cohedur RS (a Trademark) Bayer 3.30 Cohedur A (a Trademark) Bayer 2.20 In general manner, the known elastomers can be used for the walking soles if one or more of the following substances are mixed with them.
12706~3 For the manufacture of a rubber walking sole by this process, all rubber qualities known as suitable for such a sole may be used, if they are mixed with particular substances.
These substances are added in an amount from 0 to 20 parts per hundred parts of rubber.
The following substances are mentioned by way of example:
phenolformaldehyde resins, for example those supplied under the trademark Vulkadur A (Bayer AG), Coretack (BASF), methyloslised phenoloformaldehyde resins, for example those supplied under the trademark SP 1045 (Krahn), Korever (BASF); resorcin in combination with a formaldehyde dispenser, for example those supplied under the trademark Cohedur A, Cohedur RS or RK (Bayer AG); silica fillers, for exarnple those supplied under the trademark Vulkasil S (Bayer AG), Ultrasil (Degussa); an amino alcohol, for example 3-aminopropanol a primary or secondary amine, for example stearylamine; polyvinyl alcohol, for example those supplied under the trademark Mowiwol (Hoechst) or VSH 72 or VSH 73 having a viscosi-ty in the range of from 1000 to 10000 cP
10~ aqueous mixture at 25C from the firm AIR PRODUCTS; a polyol containing a high number of hydroxy groups, for example those supplied under the trademark Formrez (Witco), acrylate rubber (ACM), Hydrin (Polysar), Hercolor (Hercules); a combination of the above-mentioned substances.
For the mixtures that react to form polyurethane, there was used ether or ester polyols (B component) which are mixed with corresponding proportions of isocyanate (A component).
AS catalyst for the manufacture of the polyurethane DABCO-SB of AIR PRODUCTS was used in proportions of from 0.1 to 10% by weight and as a foam stabiliser LK 221 of AIR PRODUCTS was added.
127(~613 For the manufacture of shoes having a walking sole of an elastomer having the composition given according to one of the above mentioned embodiments 1 to 3, a mixture that reacts to form polyurethane having the following composition was used:
B component:
Bayer Polyol BS 708 100 parts composition: ester 100 parts glycol 14 parts H20 0.5 part ~;~7~6~3 DABCO-SB 25~ strength in 1.4-butanediol 1.5 parts cell stabiliser Si-free LK 221 0.6 part A component:
Prepolymer PM53 NCO 18.5% approx 74.5 parts Mixture ratio A component- B component 100 73 to 77 The elastomer was injected into a mould as shown in Fig. 1 at a processing temperature of approximately 150C. Before the injection, the die half 4 had a temperature of approximately 150C. After approximately 2 minutes the injection-moulding die 3 was opened and the die half 4 having the walking sole 6' was brought into the upper position (see Fig. 1), the mould cavity 16 was formed and the mixture was introduced into the mould cavity 16. After 3 minutes the finished shoe was removed from the mould.
A particular advantage resides in the fact that the amount of metal cataylst, for example organotin compounds, can be considerably reduced, as a result of which the known formation of skin in the polyurethane at the interface layer polyurethane/elastomer can be avoided.
lZ7~6~
Fig. 4a shows a further embodiment for an injection-moulding die for the manufacture of the walking sole 6'.
According to Fig. 4a, the injection-moulding die 25 comprises a die half 2 and a die half 26 which has an undercut 27 of slight depth and an undercut 28 contiguous therewith of greater depth and in the shape of a bead.
Fig. 4b shows a mould cavity 29 for moulding the midsole 16' using the die half 26 and the lateral mould parts 12, 13 and the last 14 having the attached upper lS from Fig. 1.
The controlled injection of elastomer and the controlled injection of the polyurethane form a surrounding bead which after finishing can be cut off perpendicular to the sole of the shoe, a perfect parting line being achieved between the elastomer and the polyurethane.
Fig. 4a shows the details of the die halves in this further embodiments. In the die half 26 having a cavity, the undercut 27 is in the form of a slot and the undercut 28 provides a flood groove. These undercuts result in the formation of a closed sealing lip 27' having an edge bead 28' on the walking sole.
The lateral mould parts 1 overlap this sealing lip so 127~613 -25=
that a sealing closure is provided for the mixture that reacts to form polyurethane.
Fig. 4b shows the details for the lateral mould parts 12, 13. ~ach of these lateral mould parts has a surrounding undercut 31 which in the closed position of the lateral mould parts overlaps the sealing lip 27' and edge bead 28. The undercut 31 forms a channel 31' for controlling injection of materal. This channel 31' together with the sealing lip 27' and bead 28' form a wide zone which ensures that in the finished shoe the connection according to the invention of the midsole with the walking sole is reliably formed even at the lateral edge.
Fig. S shows a side view of an installation 32 having an appliance 33 for injecting walking soles and an appliance 34 for processing the mixture that reacts to form polyurethane and for moulding the midsoles.
The installation has a so-called turntable 19 which is generally known in shoe-soling machines for moulding shoe soles that have a walking sole and a midsole and are manufactured from a mixture of isocyanate and polyol (see Desma Brochure p 581-5a6).
Whereas these known shoe-soling machines have two appliances 34 for processing the mixture that reacts to form polyurethane, in place of the one appliance there is the appliance 33 which is an injection machine and plasticises the elastomer from which the walking sole is injection-moulded.
lZ71~613 -2.6-Fig. 6 shows a perspective view of a shoe manufactured according to the invention having a cross-section through the sole, the tip of the shoe being cut away. 6' designates the walking sole and 16' S designates the midsole. The double-headed arrows represent symbolically the bonds achieved according to the invention, while the length of the double-headed arrows shows diagrammatically the thickness of the interface layer.
The closed position is then acted upon in such a manner that in the representation of Fig~ 2 the displaceable mould-clamping plate 1 moves downwards . At the same time,the cylinders (not shown) for the guide rails 21 are also actuated. As a result the injection-moulding die 3 is opened, that is to say the two die halves 2 and 4 disengage and at the same time the upper die half 4 disengages from the column plate 19. Fig. 3 shows the appar~u~ in ~his position. In this opened position, the mould-clamping plate 5 is pivoted so that now the lower die half 4 adopts the position of the upp~r die half 4. By appropriately actuating the working cylinder and the locking unit 20, ~2~06~3 the injection-moulding die 3 is closed. At the same time, a last 14 having an attached upper 15, on which the walking sole 6' and the midsole 16' are to be moulded, is arranged on the lateral mould parts brou~ht into their closed position. Subsequently, as explained above, the midsole 16' is moulded and simultaneously connected to the walking sole 6' and the shoe upper.
For the manufacture of walking soles, the known elastomers used hitherto can be used which, with appropriate substances, contain the reactive terminal groups and are mixed before the plasticisation.
Especially good results were obtained with the following mixture for the elastomers:
Embodiment 1 Perbunanan 2807 ~a Trademark) Bayer 100.0 stearic acid 1.0 cumarone resin 6.5 Vulkasil S (a Trademark) sayer 35.0 Ti2 5.0 MT carbon Black 0.5 triethanolamine 1.0 sulphur 1.5 MBT 0.4 DPG 0.20 Vulkalent E (a Trademark) Bayer 1.00 Cohedur RS (a Trademark) Bayer 2.25 Cohedur A (a Trademark) Bayer 4.00 Embodiment2 SBR 1712 (a Trademark) Chemie Huls 14.00 lf~71~613 CB 10 (a Trademark) Chemie Huls 43.30 Shenectady, SP 1045 (a Trademark) Shenectady6.33 SMR 5 L (a Trademark) 6.33 Aflux 42 (a Trademark) Rheinchemie 2.00 Ultrasil VN3 (a trademark) Degussa 20.00 Aktivator X 50 S (a Trademark) Degussa 2.00 ZnO 2.65 sulpher 1.73 DOTG 1.73 Embodiment 3 SBR 1500 (a Trademark) Chemie Huls 100.00 stearic acid 1.00 cumarone resin 5.00 Vulkasil S (a Trademark) Bayer 35.00 TiO2 5.00 MT carbon black 0.50 triethanolamine 1.00 sulphur 0.35 Rhenocure S (a Trademark) Rheinchemie 1.50 MOZ 1.30 MBT 0.60 TMTD 0.20 Cohedur RS (a Trademark) Bayer 3.30 Cohedur A (a Trademark) Bayer 2.20 In general manner, the known elastomers can be used for the walking soles if one or more of the following substances are mixed with them.
12706~3 For the manufacture of a rubber walking sole by this process, all rubber qualities known as suitable for such a sole may be used, if they are mixed with particular substances.
These substances are added in an amount from 0 to 20 parts per hundred parts of rubber.
The following substances are mentioned by way of example:
phenolformaldehyde resins, for example those supplied under the trademark Vulkadur A (Bayer AG), Coretack (BASF), methyloslised phenoloformaldehyde resins, for example those supplied under the trademark SP 1045 (Krahn), Korever (BASF); resorcin in combination with a formaldehyde dispenser, for example those supplied under the trademark Cohedur A, Cohedur RS or RK (Bayer AG); silica fillers, for exarnple those supplied under the trademark Vulkasil S (Bayer AG), Ultrasil (Degussa); an amino alcohol, for example 3-aminopropanol a primary or secondary amine, for example stearylamine; polyvinyl alcohol, for example those supplied under the trademark Mowiwol (Hoechst) or VSH 72 or VSH 73 having a viscosi-ty in the range of from 1000 to 10000 cP
10~ aqueous mixture at 25C from the firm AIR PRODUCTS; a polyol containing a high number of hydroxy groups, for example those supplied under the trademark Formrez (Witco), acrylate rubber (ACM), Hydrin (Polysar), Hercolor (Hercules); a combination of the above-mentioned substances.
For the mixtures that react to form polyurethane, there was used ether or ester polyols (B component) which are mixed with corresponding proportions of isocyanate (A component).
AS catalyst for the manufacture of the polyurethane DABCO-SB of AIR PRODUCTS was used in proportions of from 0.1 to 10% by weight and as a foam stabiliser LK 221 of AIR PRODUCTS was added.
127(~613 For the manufacture of shoes having a walking sole of an elastomer having the composition given according to one of the above mentioned embodiments 1 to 3, a mixture that reacts to form polyurethane having the following composition was used:
B component:
Bayer Polyol BS 708 100 parts composition: ester 100 parts glycol 14 parts H20 0.5 part ~;~7~6~3 DABCO-SB 25~ strength in 1.4-butanediol 1.5 parts cell stabiliser Si-free LK 221 0.6 part A component:
Prepolymer PM53 NCO 18.5% approx 74.5 parts Mixture ratio A component- B component 100 73 to 77 The elastomer was injected into a mould as shown in Fig. 1 at a processing temperature of approximately 150C. Before the injection, the die half 4 had a temperature of approximately 150C. After approximately 2 minutes the injection-moulding die 3 was opened and the die half 4 having the walking sole 6' was brought into the upper position (see Fig. 1), the mould cavity 16 was formed and the mixture was introduced into the mould cavity 16. After 3 minutes the finished shoe was removed from the mould.
A particular advantage resides in the fact that the amount of metal cataylst, for example organotin compounds, can be considerably reduced, as a result of which the known formation of skin in the polyurethane at the interface layer polyurethane/elastomer can be avoided.
lZ7~6~
Fig. 4a shows a further embodiment for an injection-moulding die for the manufacture of the walking sole 6'.
According to Fig. 4a, the injection-moulding die 25 comprises a die half 2 and a die half 26 which has an undercut 27 of slight depth and an undercut 28 contiguous therewith of greater depth and in the shape of a bead.
Fig. 4b shows a mould cavity 29 for moulding the midsole 16' using the die half 26 and the lateral mould parts 12, 13 and the last 14 having the attached upper lS from Fig. 1.
The controlled injection of elastomer and the controlled injection of the polyurethane form a surrounding bead which after finishing can be cut off perpendicular to the sole of the shoe, a perfect parting line being achieved between the elastomer and the polyurethane.
Fig. 4a shows the details of the die halves in this further embodiments. In the die half 26 having a cavity, the undercut 27 is in the form of a slot and the undercut 28 provides a flood groove. These undercuts result in the formation of a closed sealing lip 27' having an edge bead 28' on the walking sole.
The lateral mould parts 1 overlap this sealing lip so 127~613 -25=
that a sealing closure is provided for the mixture that reacts to form polyurethane.
Fig. 4b shows the details for the lateral mould parts 12, 13. ~ach of these lateral mould parts has a surrounding undercut 31 which in the closed position of the lateral mould parts overlaps the sealing lip 27' and edge bead 28. The undercut 31 forms a channel 31' for controlling injection of materal. This channel 31' together with the sealing lip 27' and bead 28' form a wide zone which ensures that in the finished shoe the connection according to the invention of the midsole with the walking sole is reliably formed even at the lateral edge.
Fig. S shows a side view of an installation 32 having an appliance 33 for injecting walking soles and an appliance 34 for processing the mixture that reacts to form polyurethane and for moulding the midsoles.
The installation has a so-called turntable 19 which is generally known in shoe-soling machines for moulding shoe soles that have a walking sole and a midsole and are manufactured from a mixture of isocyanate and polyol (see Desma Brochure p 581-5a6).
Whereas these known shoe-soling machines have two appliances 34 for processing the mixture that reacts to form polyurethane, in place of the one appliance there is the appliance 33 which is an injection machine and plasticises the elastomer from which the walking sole is injection-moulded.
lZ71~613 -2.6-Fig. 6 shows a perspective view of a shoe manufactured according to the invention having a cross-section through the sole, the tip of the shoe being cut away. 6' designates the walking sole and 16' S designates the midsole. The double-headed arrows represent symbolically the bonds achieved according to the invention, while the length of the double-headed arrows shows diagrammatically the thickness of the interface layer.
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A shoe having an injection-moulded midsole formed from polyurethane and an injection-moulded walking sole formed from elastomer, in which the midsole and the walking sole are connected to each other in the region of their interface by chem-ical bonds formed between isocyanate groups of the polyurethane and reactive terminal groups of substances added to the elas-tomer.
2. A process for moulding soles onto shoe uppers, the soles comprising a midsole formed from polyurethane and a walking sole formed from elastomer, said process comprising adding at least one catalyst to the mixture which reacts to form polyurethane and contains polyol and isocyanate in order to influence the reaction speed of the mixture, adding to the elas-tomer substances which have reactive terminal groups forming chemical bonds with the isocyanate, forming the walking sole, introducing the mixture for the midsole into an intermediate space between the walking sole and the shoe upper, and control-ling the reaction speed for the formation of the polyurethane and the temperature of the elastomer so that chemical bonds are formed in the region of the interface between the elastomer and the reacting mixture.
3. A process as claimed in claim 2 further comprising cooling the walking sole in the region of the interface to be formed with the polyurethane and heating the walking sole in the region of the walking surface before introducing the mixture which reacts to form polyurethane, and maintaining the average temperature of the walking sole during and after the introduction of the mixture at a temperature the decomposition temperature of the polyurethane.
4. An apparatus constructed and adapted to perform the process according to claim 2, said apparatus including at least one appliance which operates as an injection-moulding machine for plasticizing the elastomer and forming walking soles by injec-tion-moulding, and at least one appliance which operates as a shoe-soling machine for processing polyurethane for moulding mid-soles and for connecting the midsoles to walking soles and shoe uppers, wherein said at least one appliance which operates as an injection moulding machine includes an injection moulding die for forming the walking soles, channels for coolant and heating medium are provided in the injection moulding die, and means are provided for adjusting the flow rate and temperature for the coolant and heating medium so that, in use, the elastomer is vul-canized rapidly except in the region of the interface whereby vulcanization of the interface layer occurs only after introduc-tion of the mixture for the mid-sole.
5. An apparatus as claimed in claim 4 in which the or each appliance for forming the walking sole includes at least one injection-moulding die, one half of the die being arranged as a plate and having a feed bore and the other half of the die having a cavity for forming a walking sole, the appliance being arranged so that the half of the die having the cavity for the walking sole can be moved pivotally after forming a walking sole by injection moulding and opening the injection-moulding die, and the or each appliance for moulding the midsole includes two lat-eral mould parts and a last for attaching shoe uppers, the appli-ance being arranged so that the two lateral mould parts can be brought into engagement with the pivoted die half having the walking sole cavity and the last together with an attached upper in order to form a mould cavity for moulding a midsole.
6. An apparatus as claimed in claim 5 in which an appliance for injection-moulding walking soles and an appliance for moulding midsoles form one working station.
7. An apparatus as claimed in claim 6 in which the die half arranged as a plate is mounted on a displaceable mould-clamping plate guided on rails, the die half having the cavity for the walking sole is mounted on a pivotable mould-clamping plate which is mounted on a frame guided by said rails, said rails together with column plates form a machine framework, and the column plate adjacent the frame has an aperture through which the die half having the cavity can be engaged with the lateral mould parts.
8. An apparatus as claimed in claim 7 in which the pivotable mould-clamping plate (a) is a prismatic member, (b) has, perpendicular to its axis, the profile of an N-sided figure, and (c) has die halves having cavities for walking soles arranged on its side faces parallel to its axis.
9. An apparatus as claimed in claim 8 in which operat-ing cylinders are arranged between the frame and the displaceable mould-clamping plate for opening and closing injection-moulding die.
10. An apparatus as claimed in claim 5, 6 or 7 in which the die half having the cavity has an undercut opening into the cavity for the formation of a self-contained sealing lip which cooperates with the lateral mould parts during formation of a midsole.
11. An apparatus as claimed in claim 10 in which each of the lateral mould parts has an undercut which cooperates with the undercut in the die half having the cavity and which provides a controlled injection of mixture in the region of the sealing lip during processing of the polyol/isocyanate mixture.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3545750 | 1985-12-21 | ||
| DEP3545750.3 | 1985-12-21 | ||
| DEP3600682.3 | 1986-01-13 | ||
| DE19863600682 DE3600682A1 (en) | 1985-12-21 | 1986-01-13 | SHOE WITH A MIDSOLE MADE OF POLYURETHANE AND AN OUTSOLE MADE OF ELASTOMER |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1270613A true CA1270613A (en) | 1990-06-26 |
Family
ID=25839276
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000525880A Expired - Fee Related CA1270613A (en) | 1985-12-21 | 1986-12-19 | Shoe having a midsole of polyurethane and a walking sole of elastomer |
Country Status (6)
| Country | Link |
|---|---|
| CA (1) | CA1270613A (en) |
| DE (1) | DE3600682A1 (en) |
| ES (1) | ES2009212A6 (en) |
| FR (1) | FR2591868B1 (en) |
| GB (1) | GB2184638B (en) |
| IT (1) | IT1199758B (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3643821A1 (en) * | 1986-11-05 | 1988-05-19 | Kloeckner Ferromatik Desma | MOLDING STATIONS, ESPECIALLY FOR ROUND TABLE SYSTEMS, FOR MOLDING ON THE SHOE SOLE WITH AN ELASTOMER OUTSOLE AND A MIDSOLE MADE OF A MIXTURE OF ISOCYANATE AND POLYOL ON SHOE SHOES TO POLYURETHANE |
| DE3643822C1 (en) * | 1986-11-05 | 1988-03-24 | Kloeckner Ferromatik Desma | Molding stations, in particular for rotary table systems, for molding shoe soles with an outsole made of elastomer and a midsole made of a mixture of isocyanate and polyol that reacts to polyurethane onto shoe uppers |
| IT1201760B (en) * | 1986-12-05 | 1989-02-02 | Union Spa | PROCESS AND PLANT FOR THE REALIZATION OF FOOTWEAR WITH VULCANIZED RUBBER SOLE AND BICOMPONENT POLYURETHANE MIDSOLE |
| DE3643820A1 (en) * | 1986-12-20 | 1988-06-30 | Kloeckner Ferromatik Desma | SHOE WITH OUTSOLE, SIDE SOLE EDGE AND A MIDSOLE, AND METHOD AND MOLDING STATION FOR ITS PRODUCTION |
| DE3813993A1 (en) * | 1988-04-26 | 1989-11-09 | Kloeckner Ferromatik Desma | METHOD AND DEVICE FOR PRODUCING SHOE SOLES FROM THERMOPLASTIC MATERIAL AND FOR MOLDING ON SHOE SHOES |
| JPH0611243B2 (en) * | 1988-12-26 | 1994-02-16 | 青木安全靴製造株式会社 | Shoe sole manufacturing method |
| DE4233493A1 (en) * | 1992-10-06 | 1994-04-07 | Saar Gummiwerk Gmbh | Shoe esp. protective shoe with nitrile-based vulcanised moulded part - has polyurethane foam layer between moulding and upper |
| FR2710869B1 (en) * | 1993-10-08 | 1995-12-29 | M3B | Multilayer material and manufacture thereof by pouring the coating material onto the base layer. |
| ITPD20020051A1 (en) * | 2002-02-27 | 2003-08-27 | Main Group Spa | PROCEDURE FOR THE REALIZATION OF A SOLE FOR COMPOSTADA FOOTWEAR A VULCANIZED RUBBER SOLE SOLE COUPLED TO AN INT |
| DE10218239A1 (en) * | 2002-04-24 | 2003-11-13 | Kloeckner Desma Schuhmaschinen | Process for the production of particular soles in machine shoe production |
| CN110920116A (en) * | 2018-09-18 | 2020-03-27 | 德士马制鞋机械设备有限公司 | Multi-part clip base impression for direct injection into multi-layer shoe soles |
| IT202100005381A1 (en) * | 2021-03-08 | 2022-09-08 | Stemma S R L | METHOD FOR THE PRODUCTION OF FOOTWEAR BY STAMPING AND MOLD FOR THE IMPLEMENTATION OF THIS METHOD |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT230223B (en) * | 1959-08-01 | 1963-11-25 | Melangit Kunststoffabrik Ges M | Method for producing a trough bottom |
| DE1210548B (en) * | 1963-01-25 | 1966-02-10 | Phoenix Gummiwerke Ag | Device for manufacturing footwear from rubber or thermoplastic, elastic plastics |
| GB1292882A (en) * | 1970-02-27 | 1972-10-18 | Ici Ltd | Improvements in or relating to the production of laminates |
| CA977917A (en) * | 1971-09-29 | 1975-11-18 | Ladislav Hujik | Method of molding shoe soles |
| DE2241493C3 (en) * | 1972-08-23 | 1975-06-26 | Desma-Werke Gmbh, 2807 Uesen | Method and device for the production of multi-layer soles from materials of low viscosity, in particular polyurethane or rubber |
| US4018948A (en) * | 1975-09-04 | 1977-04-19 | The Goodyear Tire & Rubber Company | Method of compounding rubber |
| DE2616309C2 (en) * | 1976-04-12 | 1984-08-02 | Helmut Prof. Dr. 4020 Mettmann Käufer | Process for the manufacture of composite materials |
| JPS5814201B2 (en) * | 1976-09-27 | 1983-03-17 | 東洋ゴム工業株式会社 | Manufacturing method for shoe soles |
| US4247513A (en) * | 1979-03-14 | 1981-01-27 | Liu Chin Lien | Method of making laminated sole |
| FR2456488A3 (en) * | 1979-05-18 | 1980-12-12 | Lemaitre Securite | Shoe sole with cellular rubber or polyurethane body - over a rubber wear surface made by two=stage injection moulding |
| DE3102219A1 (en) * | 1981-01-23 | 1982-08-19 | Kurt Hegele GmbH Präzisions-Vorrichtungs- und Formenbau, 8000 München | Device for processing vulcanisable materials |
| CH661619A5 (en) * | 1982-08-16 | 1987-07-31 | Bbc Brown Boveri & Cie | METHOD AND DEVICE FOR CONTROLLING THE VOLTAGE BY AMOUNT AND / OR PHASE IN ELECTRICAL ENERGY TRANSMISSION DEVICES. |
| CH661472A5 (en) * | 1983-04-22 | 1987-07-31 | Theodor Schoettli | METHOD AND DEVICE FOR AT LEAST TWO-STAGE INJECTION MOLDING OF COMPOSED MOLDED BODIES MADE OF POLYMERS, AND USE OF THE METHOD. |
| DD235774A3 (en) * | 1984-04-05 | 1986-05-21 | Greiz Plasttechnik | DEVICE FOR PRODUCING MULTILAYER VISCOSIVE SOLES, PREFERABLY PLAST. MATERIALS |
| CH669500A5 (en) * | 1985-04-27 | 1989-03-31 | Sandoz Ag | |
| DE3516510A1 (en) * | 1985-05-08 | 1986-11-13 | Klöckner Ferromatik Desma GmbH, 7831 Malterdingen | DEVICE FOR DIRECT SOLELING ON SHOE SHOES |
-
1986
- 1986-01-13 DE DE19863600682 patent/DE3600682A1/en not_active Withdrawn
- 1986-12-10 ES ES8603347A patent/ES2009212A6/en not_active Expired
- 1986-12-15 GB GB8629885A patent/GB2184638B/en not_active Expired
- 1986-12-15 IT IT22681/86A patent/IT1199758B/en active
- 1986-12-15 FR FR868617505A patent/FR2591868B1/en not_active Expired - Fee Related
- 1986-12-19 CA CA000525880A patent/CA1270613A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| GB8629885D0 (en) | 1987-01-28 |
| ES2009212A6 (en) | 1989-09-16 |
| GB2184638B (en) | 1989-11-29 |
| GB2184638A (en) | 1987-07-01 |
| FR2591868A1 (en) | 1987-06-26 |
| IT1199758B (en) | 1988-12-30 |
| IT8622681A0 (en) | 1986-12-15 |
| DE3600682A1 (en) | 1987-06-25 |
| FR2591868B1 (en) | 1990-06-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |