WO2013068238A1

WO2013068238A1 - Silicone rubber on hotmelt adhesive

Info

Publication number: WO2013068238A1
Application number: PCT/EP2012/071157
Authority: WO
Inventors: Johann Müller
Original assignee: Wacker Chemie Ag
Priority date: 2011-11-10
Filing date: 2012-10-25
Publication date: 2013-05-16
Also published as: DE102011086103A1

Abstract

Shaped 2-layer article consisting of: (A) a first layer comprising a silicone rubber, and (B) a sheet comprising a hotmelt adhesive, with the provisos that (i) the adhesion between (A) and (B) is at least 50 N/5 cm, measured in accordance with ISO 53530, and (ii) the softening temperature of (B) is between 80 and 200°C, and (iii) the elasticity of the shaped 2-layer article exhibits at least 150% elongation at break.

Description

Silicone rubber on hot melt adhesive

Silicone rubbers are known in the art

Coating process or screen printing on

Surfaces of any kind applied and vulcanized, for example, by applying elevated temperature.

EP 2 117 366 B1 describes a process for coating garments with silicone rubber. With

Silicone rubber-coated clothing pieces are intended

prevent, for example, the slipping of the garment on the body. The coating, for example, on the underside of socks is used for accident prevention because the silicone rubber leads to a slip resistance on substrates. The coating process described in EP 2 117 366 B1 requires complex, mechanical devices which are not available everywhere and for everyone.

It was therefore an object to provide silicone rubbers in a readily processable form, so that they by means of simple methods and without the need

complex production systems on various surfaces

can be applied and fixed.

This object is achieved by the novel 2-layer molded body consisting of:

(A) a first layer of a silicone rubber,

(B) a film of a hot melt adhesive with the proviso that

(i) the adhesion between (A) and (B) is at least 50 N / 5 cm, measured according to ISO 53530, and (ii) the softening temperature of (B) is between 80 and 200 ° C, and

(iii) the elasticity of the 2-layer shaped body (A) + (B) has at least 150% elongation at break.

The silicone rubbers (A) are

commercial silicone rubbers known in the art. They are prepared by crosslinking crosslinkable silicone compositions. Such

Silicone compositions are preferably selected from the group comprising condensation-crosslinking,

addition-curing and peroxide-curing

Silicone compositions. Also the use of through

Radiation crosslinking (for example by means of UV)

Silicone compositions is possible. It can be both thermosetting and room temperature curing

Silicone compositions are used according to the invention.

The layer thickness of (A) is preferably 0.01 to 5 mm in order to ensure sufficient heat transfer to the layer (B).

The elongation at break of (A) is at least 150% measured according to DIN 53504. Preferably, it is 150 to 500%. The elongation at break of the 2-layer shaped body (A) + (B) is at least 150% measured according to DIN 53504. Preferably, it is 150 to 500%.

Examples of peroxide crosslinking HTV rubbers are silicone rubbers of the ELASTOSIL ^® R series of Wacker Chemie AG. Examples of addition-HTV rubbers are silicone rubbers of the series ELASTOSIL ^® R plus Wacker Chemie AG.

Examples of liquid silicone rubbers are silicone rubbers from the series ELASTOSIL ^® LR Wacker Chemie AG.

Examples of room-temperature-curing 2K silicone rubbers are silicone rubbers of the ELASTOSIL ^® RT series from Wacker Chemie AG.

Examples of room-temperature-1 K silicone rubbers are silicone rubbers of the ELASTOSIL ^® Type E, or ELASTOSIL ^® N, Wacker Chemie AG.

Examples of silicone rubbers which can be screen printed on the foils are silicone rubbers of the series ELASTOSIL ^® SP from Wacker Chemie AG.

Examples of thin-layer silicone rubbers are silicones of the series DEHESIVE ^® of Wacker Chemie AG.

The hotmelt adhesive (B) is usually a film of at least one thermoplastic material. Such

Plastics have long been known in the art. However, it is also possible to use films having two or more layers of different thermoplastically processable plastics. The thickness of the film (B) is preferably 5 μΐϊΐ to 1000 μιη to ensure good adhesion of the layer composite (A) and (B) on a substrate.

If the film (B) consists of several layers of thermoplastic materials, the layer thicknesses can be in any ratio. The softening temperature of the thermoplastic polymers used for (B) is in the range from +80 ° C to +200 ° C.

Examples of such thermoplastic polymers from which the films (B) can be made are:

Polyurethanes, polyester urethanes, polyether urethanes, all types of thermoplastic polyurethanes.

Polyester, copolyester, polyetherester, all kinds of

thermoplastic polyesters.

Polyamides, copolyamides, polyetheramides, all types of

thermoplastic polyamides.

Polyethylene, polyolefins, polyalphaolefins, all types of thermoplastic polyolefins.

Ethylene vinyl acetate copolymers.

However, the usable films (B) are not limited to the examples mentioned above. Rather, all types of thermoplastic polymers or plastics with a

Softening temperature of 80 to 200 ° C as films (B)

be used. The softening temperature for (B) is determined according to DIN EN ISO 11357-1.

For the production of the 2-layer shaped body according to the invention, all methods known in the prior art can be used.

A possible embodiment of the manufacturing method is that the films (B) with a

Silicone composition is coated,

and the silicone composition subsequently to a

Silicone rubber layer (B) hardens. The coating can be, for example, by doctor blade method, dipping method, extrusion method, spray or

Spray method, all kinds of roller coatings, such as

Gravure rolls, patting or order on multi-roll systems and screen printing done. Silicone compositions with high viscosities can also be applied to the films (B) in the calendering process.

The coating (A) can be over the entire surface but also in

Structures partially applied to (B).

The amount of silicone composition applied to the film (B) is usually 3 g / m ² to 5,000 g / m ² . Preferably 10 g / m ² up to 3,000 g / m ² The vulcanization of the applied silicone composition can be carried out in a temperature range from room temperature, ie about 20 to 25 ° C, up to the softening temperature of the film (B) used. Should it for vulcanization a certain temperature

they may be prepared by conventional methods such as e.g.

Hot air oven, IR radiation, contact heat and heat transfer can be applied by contact media. In the case of radiation-curing silicone compositions, the curing takes place by appropriate irradiation before or after the application of the silicone composition to the film (B).

Another object of the present invention is a 3-layer molded body consisting of:

(A) a first layer of a silicone rubber, (B) a film intermediate layer of a hot melt adhesive,

(C) a substrate, with the provisos that

(i) the adhesion between (A) and (B) is at least 50 N / 5 cm, measured according to ISO 53530, and

(ii) the softening temperature of (B) is between 80 and 200 ° C, and

(iii) the elasticity of the layers (A) and (B) is at least 150% elongation at break, and

(iv) the adhesion between (B) and (C) is at least 50 N / 5 cm, measured according to ISO 53530, and

(v) (C) is insensitive to the temperature of (ii). The process for producing the 3-layer shaped body is characterized in that

the 2-layer shaped body according to the invention is applied to a substrate (C),

it is subjected to a temperature which is at least 10 ° C higher than the softening point of (B),

with simultaneous slight contact pressure,

and thereafter cooled below the softening temperature of (B),

with the proviso that the substrate (C) is opposite to this

Temperature is insensitive, and

the effect of temperature only takes place until the film (B) softens.

The slight contact pressure takes place for example via a

Iron or a printing press. Especially when using Printing presses, a pressure of preferably at least 2 bar based on 100 cm ^{2 should be} used up.

Since (A) is insensitive to this heating, its functions are retained, for example as anti-snore.

The substrates used are preferably textile fabrics (C).

The inventive method thus represents an extreme

simple process for coating textiles with

Silicone rubbers. Another advantage is that even very open substrates or substrates with very

irregular surfaces, which can not be coated with other methods or only with great effort, with this

Method can be easily coated.

The described 2-layer moldings can also be used as

Repair materials are used, for example, for the repair of cracks or holes in textiles.

The described method is also suitable for simple

Application of logos, pictures, graphics, as well as any

Structures on different substrates / substrates.

Examples

Based on the following examples becomes the principal

Execution of the present invention explained in more detail, but without limiting to the contents disclosed therein. In the examples below, unless stated otherwise, a) all quantities are by weight;

b) all pressures at a pressure of the surrounding atmosphere, that is about 0.1 MPa

c) all temperatures at room temperature, ie 20 ° C to 25 ° C.

example 1

On a sheet of polyester urethane with a

Softening temperature of 140 ° C was a commercially available addition-crosslinking silicone composition with a

Viscosity of 300,000 mpas (ELASTOSIL ^® SP 200 from Wacker

Chemie AG) in a screen printing process in knob shape. At 135 ° C was vulcanized in 5 minutes.

The adhesion according to ISO 53530 between the layers was 320 N / 5 cm.

The elasticity of the 2-layer shaped article was: 180%

Elongation at break.

The obtained 2-layer molded body was pressed in a printing press at 180 ° C and 3 bar pressure on socks made of cotton knit. After 2 minutes, the socks were removed from the press and allowed to cool.

The knobs made of silicone rubber are fixed on the textile and show very good adhesion of more than 300 N / 5 cm to ISO 53530 After 20 washes at 60 ° C in a washing machine was none

To detect damage to the composite.

Example 2

On a film of copolyamide having a softening temperature of 150 ° C was a commercial addition-curing

Silicone rubber with a viscosity of 120,000 mpas

(ELASTOSIL LR 6250 F from Wacker Chemie AG) with a squeegee in a layer thickness of 200 μτη applied. The layer was vulcanized in 3 minutes at 140 ° C.

The adhesion according to ISO 53530 between the layers was 410 N / 5 cm.

The elasticity of the 2-layer shaped article was: 240%

Elongation at break.

The obtained 2-layer-shaped body was with a

Household iron ironed on a polyester felt with light pressure by hand. The temperature of the iron was about 200 ° C.

After cooling, a layer of silicone rubber was firmly bonded to the polyester felt. The adhesion was 360 N / 5 cm according to ISO 53530. Example 3

On a sheet of polyetheramide with a

Softening temperature of 145 ° C was coated with a commercial addition-crosslinking silicone coating agent having a viscosity of 500 mpas (DEHESIVE ^® 920 Wacker Chemie AG) with a roll applicator and vulcanized in 20 seconds at 140 ° C. The layer thickness was 10 μπι.

The adhesion according to ISO 53530 between the layers was: 190 N / 5cm.

The elasticity of the 2-layer shaped article was: 180%

Elongation at break.

The obtained 2-layer molded body was pressed after cooling to a polyamide fabric with a printing press at 170 ° C and 3 bar pressure for 30 seconds.

After cooling, a closed silicone film was fixed on the polyamide fabric. The adhesion was 180 N / 5 cm according to ISO 53530. Example 4

On a sheet of polyester urethane with a

Softening temperature of 130 ° C was a commercial condensation-curing silicone rubber with a viscosity of 50,000 mpas (ELASTOSIL ^® E 50 Wacker Chemie AG) screen-printed in the form of a knob. Overnight was stored in the air, wherein the silicone rubber hardens. The adhesion according to ISO 53530 between the layers was: 240 N / 5 cm.

The elasticity of the 2-layer shaped article was: 210%

Elongation at break.

The obtained 2-layer molded body was pressed in a printing press at 150 ° C and 3 bar pressure on a polyamide knitted fabric. The knobs made of silicone rubber are fixed on the embroidery and show very good adhesion. The adhesion was 230 N / 5 cm according to ISO 53530.

After 20 washes at 60 ° C in a washing machine, no damage to the composite was detected.

Claims

1. 2-layer molded body consisting of:

(A) a first layer of a silicone rubber,

(B) a film of a hot melt adhesive with the proviso that

(ii) the softening temperature of (B) is between 80 and 200 ° C, and

(iii) the elasticity of the 2-layer molding has at least 150% elongation at break.

2. A process for the preparation of 2-layer moldings according to claim 1, characterized in that the films (B) is coated with a silicone composition, and the

Silicone composition subsequently to a

Silicone rubber layer (B) hardens.

3. 3-layer shaped body consisting of:

(A) a first layer of a silicone rubber,

(B) a film intermediate layer of a hot melt adhesive,

(C) a substrate, with the provisos that

(v) (C) is insensitive to the temperature of (ii).

4. A process for producing the 3-layer shaped body according to claim 3, characterized in that

the 2-layer shaped body according to claim 1 is applied to a substrate (C),

with simultaneous slight contact pressure,

and thereafter cooled below the softening temperature of (B),

with the proviso that the substrate (C) is opposite to this

Temperature is insensitive, and

the effect of temperature only takes place until the film (B) softens.