Hot-Melt Adhesive

Abstract

An adhesive sheet composed of a thermoplastic and optionally one or more resins, wherein

Description

EXAMPLES

Test Methods:

Rheology A)

The measurement was carried out using a rheometer from Rheometrics Dynamic Systems (RDA II).

The Rheomatics Dynamical Analyser (RDA II) measures the torque which occurs when an oscillating shear is applied to a stripped sample (deformation control).

The sample diameter was 8 mm, the sample thickness between 1 and 2 mm. Measurement was carried out using the plate-on-plate configuration (parallel plates). The temperature sweep was recorded from 0 to 150° C. with a frequency of 10 rad/s.

Iso-Bending B)

The Iso-bending test is carried out in analogy to the Iso/IEC standard 10373:1993 (E)—section 6.1. The test is passed if a total of more than 4000 bends is attained.

Extreme Flexural Test C)

In the extreme flexural test a cutout 3 cm wide, with the electrical module lying in the center, is cut from the chip card and then pressed together 10×from a width of 3 cm to a width of 2.5 cm. The test is passed is the electrical module does not become detached.

Hand Test D)

In the hand test the chip card is bent by hand over one of the two corners lying closer to the electrical module, to an extent such that the card breaks or the module breaks. The test in that case is passed. If the electrical module becomes detached or springs out, the test is failed.

MFI E)

The melt flow index, MFI, was carried out in analogy to ISO 1133 (Procedure B, volume flow rate MVR). The test was carried out at 150° C. at 2.16 kg.

Other Test Methods

Molar masses were determined by GPC (gel permeation chromatography) measurements. (Preparation of a solution of the sample in tetrahydrofuran with a concentration of 3 g/l; dissolution at room temperature for 12 hours; subsequently, filtration of the solution through a 1 μm disposable filter, addition of approximately 200 ppm of toluene as internal standard.

Using an autosampler, 20 μl of the solution are chromatographed as follows: a 10³⊕ column 50 mm long is followed by one 10⁶⊕, one 10⁴⊕, and one 10³⊕ column, each with a length of 300 mm. The eluent used is tetrahydrofuran, which is pumped at a flow rate of 1.0 ml/min. The columns are calibrated with polystyrene standards, detection taking place by the measurement of the change in refractive index with the aid of a Shodex differential refractometer RI 71).

The softening temperatures are determined preferably by way of differential scanning calorimetry (DSC).

INVESTIGATIONS

Reference 1)

Polyamide film XAF 34.408 from Collano-Xiro

Reference 2)

PU film XAF 36.304 from Collano Xiro

Example 1

Griltex 9 E (copolyester) from EMS-Grilltech+25% by weight EPR 0191 (epoxy resin, bisphenol A resin with 60° C. softening range) from Bakelite were blended in a recording compounder from Haake at approximately 130° C. for 15 minutes at 25 rpm. The heat-activable adhesive was subsequently extruded at 140° C. between two plies of siliconized glassine release paper to 60 μm.

According to test method E) the MFI was 30 cm³/10 minutes.

Example 2

Griltex 9 E (copolyester) from EMS-Grilltech was extruded at 140° C. between two plies of siliconized glassine release paper to 60 μm. According to test method E) the MFI was 18 cm³/10 minutes.

Example 3

Platamid 2395 (copolyamide) from Atofina+20% by weight EPR 0191 (epoxy resin, bisphenol A resin with 60° C. softening range) from Bakelite were blended in a recording compounder from Haake at approximately 130° C. for 15 minutes at 25 rpm. The heat-activable adhesive was subsequently extruded at 140° C. between two plies of siliconized glassine release paper to 60 μm.

According to test method E) the MFI was 16 cm³/10 minutes.

Implantation of Electrical Modules

The electrical modules were implanted in the card body using an implanter from Ruhlamat.

The materials employed were as follows:

Electrical modules: Nedcard Dummy N4C-25C, Tape-Type: 0232-10 PVC card: CCD ABS card: ORGA

In a first step examples 1 to 3 are laminated at 2 bar onto the module belt from Nedcard, using a two-roll laminator from Storck GmbH.

The electrical modules are then implanted in the appropriate cavity in the card body.

The parameters employed were as follows for all the examples:

• Heating step: 1
• Die temperature: 150° C.
• Time: 1×2 s
• Cooling step: 1×800 ms, 25° C.
• Pressure: 70 N per module

RESULTS

The chip cards produced using the inventive adhesives were tested by methods B, C, and D. The results are set out in Table 1.

TABLE 1
Examples	Test method B	Test method C	Test method D
1	passed	passed	passed
2	passed	passed	passed
3	passed	passed	passed

From table 1 it is apparent that all of the inventive examples met the principal criteria for a chip card and hence are very suitable for adhesively bonding electrical modules to card bodies.

The rheological properties are listed in table 2 below.

TABLE 2
Examples	G′ in [Pa] at 23° C.	G″ in [Pa] at 23° C.	Crossover
1	1 × 107	2.5 × 106	110° C.
2	1.3 × 108	2.9 × 107	120° C.
3	1 × 107	2.1 × 106	108° C.

Claims

1. An adhesive sheet of an adhesive system composed of a thermoplastic and optionally one or more resins, having a) a softening temperature of greater than 65° C. and less than 125° C.,b) a melt flow index (ISO 1133) of greater than 3 and less than 100 cm3/10 minutes,c) a storage modulus G′ at 23° C., as measured by test method A, of greater than 107 Pas,d) a loss modulus G″ at 23° C., as measured by test method A, of greater than 106 Pas,e) and a crossover, as measured by test method A, of less than 125° C.

2. The adhesive sheet of claim 1, wherein the layer thickness is between 10 and 100 μm.

3. The adhesive sheet of claim 1, wherein said thermoplastic is selected from the group consisting of copolyamides, polyethyl-vinyl acetates, polyvinyl acetates, polyolefins, polyurethanes, and copolyesters.

4. The adhesive sheet of claim 1, wherein said resins are reactive resins comprising one or more members of the group consisting of epoxy resins, phenolic resins and novolak resins.

5. A method for bonding chip modules in card bodies which comprises bonding said chip modules in said card bodies with the adhesive sheet of claim 1.

6. The method of claim 5, wherein said chip modules are polyimide-, polyester or epoxy-based chip modules and said card bodies are PVC, ABS, PET, PC, PP or PE card bodies.

7. A method for producing a heat-activable adhesive tape, which comprises coating an adhesive system composed of a thermoplastic and optionally one or more resins, having a) a softening temperature of greater than 65° C. and less than 125° C.b) a melt flow index (ISO 1133) of greater than 3 and less than 100 cm3/10 minutes,f) a storage modulus G′ at 23° C., as measured by test method A, of greater than 107 Pas,g) a loss modulus G″ at 23° C., as measured by test method A, of greater than 106 Pas,h) and a crossover, as measured by test method A, of less than 125° C. onto a release paper or a release film.

8. The adhesive sheet of claim 2, wherein said layer thickness is between 30 and 80 μm.