CH626393A5 - Methods for the adhesive bonding of a polyurethane film or a polyurethane layer to vulcanised or unvulcanised rubber - Google Patents

Description

The present invention relates to a method for gluing a polyurethane film or a polyurethane coating to vulcanized or non-vulcanized rubber. In this process, a primer is applied to the vulcanized or unvulcanized rubber, which contains an ethylene-propylene copolymer or terpolymer, which will be explained in more detail below and which must contain certain groups, and so on treated surface is then first applied to the film or the polyurethane coating. The present invention further relates to a method for adhering a material to a mass of thermoplastic synthetic resin and unvulcanized rubber, which contains an ethylene-propylene copolymer or a terpolymer. In this method, too, first the abovementioned primer is applied to the surface of the mass of unvulcanized rubber and thermoplastic synthetic resin, and then a layer of polyurethane cement is applied, and the material to be bonded is then applied under pressure and the curing takes place under the action of pressure of the polyurethane cement.

The present invention thus relates to the connection of vulcanized or non-vulcanized rubber with other materials, it being imperative that either these other materials are connected with the aid of a polyurethane binder, or that they themselves are a polyurethane film or a polyurethane coating.

The previously usual methods for painting or painting rubber, for example molded articles made of rubber, existed either

1) in a complex surface treatment of vulcanized rubber (e.g. with UV light or ozone) and subsequent application of the paint or

2) in the use of certain hardening systems such as Resin or Vultac 5 hardener to achieve good adhesion between paint and rubber.

A much simpler and cheaper adhesive process has now been developed, which makes it possible to permanently bond polyurethane foils or coatings or even a polyurethane adhesive to a surface of vulcanized or non-vulcanized rubber by treating the surface with a primer beforehand . In no way could it have been foreseen that a very good adhesion between rubber and polyurethane could be achieved simply and inexpensively by this novel process.

An object of the present invention is therefore a method for gluing a polyurethane film or a polyurethane coating to vulcanized or non-vulcanized

s

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gated rubber, which is characterized in that the surface of the vulcanized or unvulcanized rubber containing an ethylene-propylene copolymer or terpolymer is treated with a primer containing an organic compound containing one or more groups of the formula

_> N-X

has, in these groups X denotes a halogen atom, and that a polyurethane film or a polyurethane coating is applied to the surface treated in this way.

A preferred rubber used in this process according to the invention is one which contains an ethylene-propylene copolymer or an ethylene-propylene-diene terpolymer and a further rubber, the amount of ethylene-propylene copolymer or ethylene-propylene -Diene terpolymer accounts for 30-50 wt .-%, based on the total weight of the polymer materials.

Another object of the present invention is a method for adhering a material to a mass of thermoplastic resin and unvulcanized rubber which contains an ethylene-propylene copolymer or terpolymer and rubber, which is characterized in that the surface of the mass made of thermoplastic resin and rubber treated with a primer containing an organic compound having one or more groups of the formula

> N-X

has, in this formula X is a halogen atom, and applies a layer of a polyurethane adhesive to the surface treated in this way, to the layer of polyurethane adhesive applies the material to be bonded, allows pressure to act and the polyurethane adhesive cures under the action of pressure leaves.

In this last-mentioned method, it is also advantageous to provide the material which is to be glued to the mass of thermoplastic resin and uncured rubber with a layer of polyurethane adhesive, preferably after the material has been treated with a primer. In this process, the mass of thermoplastic resin and unvulcanized rubber may contain 10-30% by weight of another rubber in addition to the ethylene-propylene copolymer or ethylene-propylene-diene terpolymer, the percentages being based on the total weight made of rubber and thermoplastic resin in bulk.

According to a particularly preferred embodiment of the last-mentioned method, the mass made of thermoplastic synthetic resin and unvulcanized rubber is a shaped body which has the shape of a shoe sole, and the material which is to be glued to it is a shoe upper.

In the processes according to the invention, a halogenated hydantoin is advantageously used as the primer which contains an organic compound which has one or more of the stated nitrogen-containing groups. Particularly preferred such halogenated hydantoins are the I ^ N'-dibromo-S, 5-dimethylhydantoin or the N, N'-dichloro-5, 5-dimethylhydantoin.

The present invention further provides a polyurethane film or a polyurethane coating bonded to a vulcanized or non-vulcanized rubber by the process according to the invention.

Furthermore, the present invention relates to a composition of a thermoplastic synthetic resin and unvulcanized rubber, which contains an ethylene-propylene copolymer or an ethylene-propylene-diene terpolymer. This composition is characterized in that it is coated on at least part of its surface with a primer which contains an organic compound which has one or more groups of the formula

^ N-X

has, in these groups X is a halogen atom, and that there is a layer of a polyurethane cement over this layer of the primer.

As a result, the ethylene-propylene copolymer is also abbreviated as "EP" and the ethylene-propylene-diene terpolymer is referred to as "EPDM".

As already mentioned, the surfaces to be glued using the method according to the invention must consist of a vulcanized or non-vulcanized rubber which contains EP or EPDM. The rubber can consist of 100% EP or EPDM, or it can consist of a rubber mixture, provided that one or more mixture components consist of EP or EPDM.

EP copolymer is usually made by copolymerizing the monomers ethylene or propylene in the presence of a Ziegler catalyst at relatively low temperatures and pressures.

EP can be used; however, EPDM is preferably used as the ethylene / propylene rubber. These terpolymers are usually made by adding a feed stream containing ethylene, propylene and polymerizable diolefin in the presence of an inert saturated C5 to C8 hydrocarbon diluent, e.g. an alkane or cycloalkane such as n-pentane, isopentane, n-hexane, isohexane or n-octane, in contact with a Ziegler catalyst. The copolymerization is usually carried out at a pressure of 1 to 5 atmospheres. The third monomer usually consists of a Cé to C16 non-conjugated diolefin, e.g. 1,5-hexadiene, 1,5-octadiene or a 2-alkyl-norbornadiene such as methylidene-norbornene or ethylidene-norbornene. The preferred EPDM has a high ethylene content of 50 to 75, e.g. 55% by weight in the copolymer.

Other rubbers that can be incorporated into the EP or EPDM rubber are e.g. Butyl rubber, halogenated butyl rubber, polyisobutene rubber, styrene / butadiene rubber (SBR), polyisoprene rubber (IR), polybutadiene rubber (BR) or natural rubber (NR).

Butyl rubber contains a copolymer of a major proportion, e.g. 85 to 99, and preferably 95 to 99% by weight of a C4-C8 isoolefin such as isobutene and a minor proportion, e.g. 0.1 to 15, and preferably 0.5 to 5% by weight of a C4-Cw multiolefin, preferably a C4-Cs diolefin such as butadiene, dimethylbutadiene, piperylene or isoprene.

In the manufacture of halogenated butyl rubber, unmodified, non-vulcanized butyl rubber is halogenated, e.g. chlorinated or brominated such that it contains about 1 atom of chlorine or bromine per molecule or multiolefin in the polymer. Halogenated butyl rubber usually has an average molecular weight (viscosity measurement) between 150,000 and 1,500,000 and an unsaturation between 0.5 and 15 mol%.

The preferred polyisobutylene rubber (made by polymerizing isobutylene) has a Staudinger molecular weight of 45,000 to 150,000.

Styrene / butadiene rubber is obtained by copolymerizing styrene and butadiene in emulsion or solution polymerization.

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The preferred isoprene rubber has a molecular weight. weight of more than 1 million and a cis-1,4-polymer content of more than 85 and preferably more than 90%.

If the rubber part is vulcanized and contains a rubber other than EP or EPDM, the mixture of EP or EPDM and other rubber contains 30 to 50% by weight of EP or EPDM, based on the total weight of the polymers.

The thermoplastic rubber mixture may also contain a thermoplastic resin, e.g. a thermoplastic polyolefin, polystyrene or ethyl / vinyl acetate copolymer (EVA). A mixture of thermoplastic resin can also be used.

The thermoplastic polyolefin can e.g. be a low or high density polyethylene or polypropylene. Low density polyethylene (LDPE) is usually made by mixing ethylene at high pressures, e.g. from 30 to 2500 atmospheres, in the presence of a polymerization catalyst, e.g. an organic peroxide such as lauroyl peroxide polymerized.

Another suitable polyolefin is low pressure polyethylene, which usually has a density of 0.94 to 0.96 and a molecular weight of 30,000 to 500,000 (determination by the intrinsic viscosity). The low-pressure polyethylene is produced by the known polymerization processes with a Ziegler catalyst (e.g. ÄlCb and TiCk). Another suitable polyolefin is low pressure isotactic polypropylene, which usually has a density of 0.86 to 0.91 and a molecular weight of 50,000 to 500,000 (determination by the intrinsic viscosity). This low pressure polypropylene is made in a similar manner to the low pressure polyethylene.

The ethylene / vinyl acetate copolymers which can be used in the composition according to the invention can be produced by a polymerization process under high pressure and using a free-radical catalyst. Ethylene / vinyl acetate copolymers with a copolymerized vinyl acetate content in the range of 5 to 45% by weight are useful, and those with a vinyl acetate content of 13 to 15% by weight are preferred. High molecular weight copolymers are best suited. These ethylene / vinyl acetate copolymers have an intrinsic viscosity of 0.5 to 1.1 in toluene at 30 ° C. when 0.25 g copolymer is dissolved in 100 ml toluene. Copolymers with an intrinsic viscosity of 0.7 to 1.0 are preferred. The melt index of the ethylene / vinyl acetate copolymers is usually 1 to 500, and copolymers having a melting point of 2 to 150 g / 10 min are preferred.

If another rubber is added in addition to ED or EPDM, the thermoplastic unvulcanized rubber mixture preferably contains 10 to 30% by weight of the further rubber, the percentage being based on the total weight of the polymers (i.e. rubber plus thermoplastic resin) in the mixture. Preferably, the thermoplastic unvulcanized rubber mixture contains 30 to 50 parts of EP or EPDM, 10 to 30 parts of another rubber, e.g. B. SBR, and 15 to 60 parts of thermoplastic resin, e.g. 15 to 60 parts of ethylene / vinyl acetate copolymer and 0 to 25 parts of high density polyethylene, the total amount of the parts being 100 and parts by weight based on the total weight of rubber plus thermoplastic resin. The preferred total amount of rubber is thus between 40 and 60% by weight of the total amount of rubber and thermoplastic resin in the mixture.

The thermoplastic rubber mixture can contain a blowing agent, so that the mass expands during injection molding or blow molding. This is particularly useful in the production of shoe soles with micro cells. The blowing agent decomposes into a gas at the working temperature of, for example, 150 to 170 ° C or more, and the gas developed leads to the formation of numerous cells in the mass.

Suitable blowing agents include azodicarbonamide, azo-bis-isobutyronitrile, p.p'-oxy-bis-benzenesulfonylhydrazide, benzenesulfohydrazide, N, N'-dinitrosopentamethylenetetramine, N, N'-dimethyl-N, N'-dinitrosoterephthalamide, urea , Methyl formate, ammonium carbonate, ammonium bicarbonate and sodium carbonate. Azodicarbonamide is preferred. The amount of blowing agent is between 0 and 5.0 parts by weight per 100 parts by weight of the total polymers.

The rubber part made of thermoplastic rubber mixture can also contain other components, e.g. Reinforcing agents, tackifying agents, fillers, plasticizers, antioxidants, coloring pigments and activators for the blowing agent. Reinforcing agents and fillers such as carbon black, hydrated aluminum silicate, finely divided silica, magnesium silicate, calcium carbonate and aluminum hydroxide can be used. In general, any plasticizer commonly found in rubber can be used, provided that it is compatible with the rubbery copolymer. Examples of such plasticizers are naphthenic oils, paraffin oils and esters such as tributoxyethyl phosphate or amines such as triethanolamine. Zinc oxide serves as an example of a useful activator. These additives can be used in amounts of 0 to 15% by weight, based on the total weight of the thermoplastic rubber mixture.

It is very expedient to use an adhesion promoter which is mixed into the rubber part or the thermoplastic rubber mixture. Suitable adhesion promoters are multifunctional compounds with at least one amino group, e.g. B. polyamines such as the polyalkylamines such as tetraethylene pentamine, arylamines such as 4-isopropylamino-diphenylamine, octamine (reaction product of diphenylamine and diisobutylene) and N, N-diphenyl-p-phenylendiamine or hexamethylenetetramine. Further examples of multifunctional compounds are the alkanolamines, in particular dialkanolamines, or trialkanolamines such as triethanolamine.

The thermoplastic rubber seal is typically made by mixing all of the ingredients in a Banbury mixer, e.g. 3 minutes at 120 ° C. The mass is then removed from the mixer, poured onto a cold roller and passed through a granulating machine. The granules can be fed to a sod making machine, which is typically an injection molding or compression molding machine. In this injection molding or press injection machine, the cylinder temperature is 150 to 210 ° C, the molds are cold or have room temperature.

Pre-shaped or pre-cut sod units are combined on the assembly line with other parts of the shoe.

According to a preferred embodiment of the invention, the mass of thermoplastic rubber mixture forms a shoe sole. Of course, it can also be of any other form, e.g. it can be automobile bumpers, the lining of automobile tire sidewalls, bicycle tire sidewalls or decorative parts of the automobile.

Before the application of the polyurethane adhesive, a primer is applied to the surface of the vulcanized rubber part or the thermoplastic uncured rubber mixture. This primer preferably consists of a halogenated hydantoin such as N, N'-dibromo-5,5-dimethylhydantoin or N, N'-dichloro-5,5-dimethylhydantoin of the formula s

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626393

CEb CHs o - C

N- /

X

N-X

\

O

where X denotes chlorine or bromine. However, the invention is not restricted to hydantoin derivatives, but any organic compounds with one or more can generally be used

^ • N-X groups,

where X is a halogen, e.g. Denotes chlorine or bromine, ver-1. CH3-CO — NHBr

2. CHî-CO-

"^ NBr

CH2-CO-

^ \ / CQ

r 'lc> 81

be applied. Instead of the halogenated hydantoins you can use:

1. N-haloamides, e.g. B. N-bromoacetamide see

2. N-haloimides, e.g. B. N-Bromosuccinimide

3. N-halophthalimides, e.g. B. N-chlorophthalimide

10 4. Halogenated melamines, e.g. B. Trichloromelamine

5. N-halosulfonamides, e.g. B. N, N, N ', N'-tetrachloroxy-bis- (benzenesulfonamide)

is 6. N-halogen urea derivatives, e.g. B. Carbon tetrachloride

7. N-halogenoisocyanuric acids, e.g. B. trichloroisocyanuric acid

N-bromoacetamide

N-bromosuccinimide

N-chlorophthalimide

4- C1HN

-ri

NHC-1

"NHC1

Trichloromelamine

5.

Cl

N ~ S02 Q- ° -0 "S02 -

Cl

Cl

/

\

Cl

TCOBS

Tetrachloroxy-bis- (benzenesulfonamide)

6. Cl

Cl

1

- N

0

II

-0-

O

II

-O-

N

1

N

Carbon tetrachloride

Cl

XC1

7. Cl

I.

0 / V

Cl-N N-Cl

Trichloroisocyanuric acid

O

626393

6

The primer is conveniently applied to the surface of the vulcanized rubber part or the mass of thermoplastic rubber mixture by placing it in a solvent, e.g. Benzene, toluene or acetone dissolves, preferably in 5 to 20% by weight solution in dry acetone.

After application of the primer to the mass, e.g. a shoe sole, the polyurethane adhesive is overlaid on the treated surface. The polyurethane adhesive is an adhesive containing polyurethane and catalyst. Examples of polyurethane adhesives are as follows:

Adhesive

"BU 8300" (British United Shoe Machinery Co.)

"Lambiotte Agostick 105 M"

Isocyanates / catalysts «SDP 102» (BUSM)

«Lambiotte catalyst» (colorless)

Combination adhesive / catalyst «Tivoli 3616»

You can also wipe the surface with catalyst before applying the polyurethane adhesive (which in this case contains no catalyst). Common catalysts are isocyanate solutions. Examples are "PU Adhesive BU 8300", plus wiping with isocyanate "SDP 102".

The part to be bonded to the mass is then connected to the layer of polyurethane adhesive. If necessary, it can also be treated with both primer and polyurethane adhesive or with polyurethane adhesive alone. Before the solidification, the adhesive is activated by radiant heat or IR or UV lamps. If it is a question of shoe manufacture, the part consists of the upper part of the shoe, e.g. is made of polyvinyl chloride or leather. Another embodiment of the invention can be a thin sheet or film that forms the white sidewalls of automobile or bicycle tires.

After the part has been bonded to the treated surface with the polyurethane adhesive, the thermoplastic mass solidifies under pressure.

The adhesive is activated, for example, by heating or by using an infrared or ultraviolet lamp. Immediately after activation, pressure is applied to ensure adhesion. When manufacturing shoes, the pressure should only be so great that the sole is brought into contact with the upper.

If the invention is used to apply a film or a coating of polyurethane to a surface of a vulcanized rubber part, the coating has good adhesion to hardened EPDM or EPDM mixture, with the possibility of sulfur hardening and the properties of the vulcanized rubber part not being impaired . The invention can therefore be used in the manufacture of safety bumpers, visor shields, side decorations and white or colored side walls of automobile tires.

In the following examples, various ingredients were conventionally mixed in a mixer, discharged at 150 ° C, finished in a second pass, and discharged at 90 ° C. The mixture was cured in a press at 160 ° C for 5 minutes. The press hardened pieces were cleaned with xylene, then brushed with a solution of 10% N, N'-dibromo-5,5-dimethylhydantoin in acetone. After 2 hours, the polyurethane coatings were applied.

The adhesion test followed a quality test on paints, which is harder than the usual test with adhesive tape. A 30 ° "X" cut was made with a knife on the coated surface and an attempt was made to pull the coated film off the surface. The rating "good adhesion" was given if no peeling of the film could be observed.

example 1

The following compounds were mixed together and treated as described above:

Vistalon 5600 (EPDM)

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GPR (SBR1502)

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70

Russ FEF

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150

Oil Flexon 876

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50

ZnO

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5

Stearic acid

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1

Caloxol "1"

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S

1.8

1.8

MBTS (benzothiazyl disulfide)

0.7

0.7

TMTDS (tetramethylthiuram disulfide)

0.2

0.2

DOTG (di-o-tolylguanidine)

1.2

1.2

Adhesive surface: brominated good good non-brominated none none

+ Caloxol is calcium oxide, then hydrolyzed to calcium hydroxide.

Example 2

The following compounds were mixed, discharged at 150 ° C., finished in a second pass (discharged at 90 ° C.) and hardened in a press for 15 minutes at 160 ° C., the pressure-hardened pieces were cleaned as described in Example 1 with primer treated and tested.

Formulations and results:

Vistalon 5600/2504 50/50 50/50

Russ FEF

50

0

Argirec KN15

100

150

Oil Flexon 876

50

50

ZnO

5

5

Stearic acid

1

1

S

1.2

1.2

MBT (mercaptobenzthiazole)

1.5

1.5

MBTS

1.5

1.5

Vocol S (vulcanizing agent)

2nd

2nd

ZDBDC (zinc dibutyldithiocarbamate)

0.8

0.8

Adhesive surface: brominated good good non-brominated none none

Example 3

Three thermoplastic unvulcanized rubber compounds were made from the following components:

Mixture A parts by weight

Mixture B

Vistalon 3708 (EPDM)

35

35

SBR 1509

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15

EVA 28-24

25th

-

EVA 30-120

-

30th

LDPE H-701

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Hisil 233 (silica filler)

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9

Amberol ST 149

(Phenol / formaldehyde resin)

6

8th

N600 Oü (mineral oil)

6

6

Triethanolamine

-

3rd

Nonox ZA (4-isopropylamine

diphenylamine)

-

0.1

BHT (trialkylated hydroxytoouol

Antioxidant)

0.1

-

Zinc oxide

5

2nd

Genitron AC2 (propellant)

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Mixture C consisted of a 50:50 (weight) mixture which (sole / heel) was fed to a shoe manufacturing machine. Blends A and B. The properties of the resulting sole / heel were

Each mixture was separately injection molded as follows:

Mixture A

Mixture B

Mixture C

Target area

Shore A hardness (30 sec.)

72

66

65-70

65-70

MFI (9/10 min.)

0.15

2.4

1.0

> 1.0

Adhesion (kg / cm)

4.0-6.0 +

+

+

> 6+

+ Pulling or tearing of the material

Each sole / heel was visually inspected and treated with the hydantoin primer used in Examples 1 and 2 and then dried for about 2 hours. Then the parts were fed to the band for shoe production and combined with the prefabricated upper. The tops were also treated with hydantoin primer, although this treatment is optional. They were then dried on the belt for about 30 minutes. Then polyurethane adhesive was applied to each sole / heel and the upper, followed by drying for about 30 minutes.

15 The polyurethane adhesive was then activated using IR radiant heat. The sole / heel and uppers were solidified in a semi-automatic press, and the shoes produced in this way were checked and packed.

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Claims (10)

626393 2nd PATENT CLAIMS 1. A method for gluing a polyurethane film or a polyurethane coating to vulcanized or unvulcanized rubber, characterized in that the surface of the vulcanized or unvulcanized rubber which contains an ethylene-propylene copolymer or terpolymer, is treated with a primer which contains an organic compound which has one or more groups of the formula _ ^> N-X has, in these groups X denotes a halogen atom, and that a polyurethane film or a polyurethane coating is applied to the surface treated in this way. 2. The method according to claim 1, characterized in that the rubber comprises an ethylene-propylene copolymer or an ethylene-propylene-diene terpolymer and another rubber and 30 to 50 wt .-% ethylene-propylene copolymer or ethylene-propylene -Diene terpolymer, based on the total weight of the polymer, contains. 3. The method according to claim 1 or 2, characterized in that a halogenated hydantoin, preferably N, N'-dibromo-5,5-dimethylhydantoin or N, NM3ichloro-5,5-dimethylhydantoin, is used as the primer. 4. A method for adhering a material to a mass of thermoplastic resin and unvulcanized rubber which contains an ethylene-propylene copolymer or terpolymer and rubber, characterized in that the surface of the mass of thermoplastic resin and rubber with treated with a primer containing an organic compound having one or more groups of the formula ^ asr-x, where in this formula X is a halogen atom, and a layer of a polyurethane adhesive is applied to the surface treated in this way, the material to be adhered is applied to the layer of polyurethane adhesive, pressure is applied and the polyurethane adhesive is allowed to harden under the action of pressure. 5. The method according to claim 4, characterized in that the material to be glued to the mass of thermoplastic resin and unvulcanized rubber is also provided with a layer of polyurethane adhesive, preferably after the material with a primer was treated. 6. The method according to claim 4 or 5, characterized in that the mass of thermoplastic resin and unvulcanized rubber 10 to 30 wt .-% of another rubber, in addition to the ethylene-propylene copolymer or ethylene-propylene-diene terpolymer contains, the percentages refer to the total weight of rubber + thermoplastic resin in the mixture. 7. The method according to any one of claims 4 to 6, characterized in that the mass of thermoplastic synthetic resin and unvulcanized rubber is in the form of a shoe sole and that the material to be glued to it is a shoe upper. 8. The method according to any one of claims 4 to 7, characterized in that a halogenated hydantoin, preferably N, N'-dibromo-5,5-dimethy] hydantoin or N, N'-dichloro-5,5-dimethylhydantoin, is used as the primer , used. 9. According to the method of claim 1, with a vulcanized or non-vulcanized rubber glued polyurethane film or glued polyurethane coating. 10. Composition from a thermoplastic synthetic resin and unvulcanized rubber, which contains an ethylene-propylene copolymer or an ethylene-propylene-diene terpolymer, characterized in that the composition is coated on at least part of its surface with a primer which contains an organic compound containing one or more groups of the formula ^> N-X has, in these groups X is a halogen atom, and that there is a layer of a polyurethane cement over this layer of the primer.