DE1629601A1 - Laminated, thermoplastic film with improved tear strength - Google Patents

Description

DR.-ING. WALTER ABITZ β Uftnoh · «27, Pl.nzenauerstrato 28

DR. DIETER MORF T.l.fon 483225 and 486415

Telegram·! Chemlndui Mündten Patent attorney

October 26, 1966 RC-37

FOKT OP CANADA LIMITKD Box 660 »Montreal 3 # Canada

Laminated, thermoplastic film with rerbeeserter Tearing fairness

The invention relates to laminated films and more particularly a process to improve the strength of laminated, oriented foils.

If a film made of a thermoplastic material sur Production of a uniaxially oriented film is only stretched in one direction, this will normally result in the Eugfeatigkeit in the stretching direction improved »while their resistance to a. Tear down in this direction will ο it will also be the resistance to onward travel sen usually markedly increased at right angles to the reverse. It has already been proposed to use technical foils

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thermoplastic materials with high strength thereby to create «, that ·· there are two mono-orientated foils laminated in such a way that the stretching directions are practically at right angles to each other. However, Ee was found that with this type of lamination of the two foils that polie with the high tensile strength in the tear direction as tear strips for the film with the high Resistance to onward travel works. As a result, the total tear strength is of the assembled structure less than the sum of the tear strengths of the individual foils.

Ss is therefore an aim of this invention "a method" for Her · »Division of a cross laminated film with improved Belssfestlgkelt to provide.

Another gate of the present invention is a ttftor Cross laminated structure made of mono-oriented films is made and has a high tear strength.

The invention now relates to a film structure with improved resistance to further travel which has at least two oriented, thermoplastic film contains »the in the way

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are laminated on top of each other that the orientation lines the one of its foils curl at a certain angle lie and that the peel off one film from the neighboring one Foil of the laminated structure, the force required is less than al3 394 g / cm width

The invention is illustrated by the following examples Practice illustrated, but not limited.

On an ethyl «η-ϊuten-Miechpolyaerieat an oriented film is produced duroh Reoken on about the 4p5-faohe in only one direction. The film produced in this catfish has a strength of 35 "4 g / yd" if it is torn across the stretching direction, and τ on 0 _t 59 g / ^ Ui if it is torn parallel to the stretching direction.

Cross laminates are made from two pieces of the film described above in such a way that the orientation rioh *. These are practically at a right angle m- puadsr. Laminates are produced under different conditions and with different interlayers that act as adhesives to join the films. A special laminate is obtained “by the surface of the oriented film

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treated with chlorine to create a tacky surface, and then pressed the laminate together two foils is produced.

Other laminates are made by extrusion, from melted Polyethylene made between "white sheets" Different Peel strengths are obtained by varying the temperature of the extrudate · If the temperature of the molten If the polyethylene is high, there will be a better connection between the sheets. This leads to a laminated Foil with higher resistance to absorption and thus lower Tear strength as shown in Table A.

Another group of laminates is made using various rubber interlayers. These Examples is the rubber composition in a suitable Dissolve carbon-hydrogen solvent and brush with a brush applied to the foil. The foils will then «wipe a pair of holding rollers and thereby united.

The two butyl rubber «and the polyisobutylene adhesive are identified by their Staudinger molecular weight » The "Stautiinger molecular weight" is a quick method

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to determine the Dttrohsobjaitts ^ Mölekulargtwiohte of Butyl chew chews and polyisobutylene that give bribes does not necessarily reflect the true molecular weight of the sample. In spite of this discrepancy, the beat tuning method delivers however, valuable information and is often used in place of the cumbersome methods «the are necessary to determine the true values.

To determine the Staudinger MolekulargewiohtB a portion of the sample in a prescribed Jjösungsaittel is dissolved in a known ratio, and the kinematic Viscοε ¹ el innovations of this solution, as well as the solvent without Zugatx the sample are measured. The intrineic viscosity (which represents a special relationship between the viscosities given above) results from these values according to the following equation

23.03 x log _in relative viscosity

Intrineie-ViscQSitü * «., ^^^^ JL-, ~~

ag polymer per ml of solution

The Staudinger molecular weight is then determined as follows! Molecular Weight «Intrins ^ e Viscosity

3.18 χ 10 ~ ⁵

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The two ethylene propylene SauteohulsHRebeBlttel are identified by their Mooney-Vieeosltttt.

This viscosity is determined according to ASSN D 927-491, by delimiting a serrated steel runner in the Eautsohuksaise, dl «too two intermeshing shapes; Bit is rotated at a speed of 2 Uadrehusigen per minute · The determination takes place at 10O ⁰ C. The depth is measured after 4 minutes ·

The tear resistance of the various samples is measured according to the method specified in ASfH D 1922-61T ₉ "Propagation feet resistance of plastic film and thin sheeting". Siege test is, Kuri said, carried out the following cases:

The sum of four tears of a film sample in the transverse direction necessary force in grams is measured with the help of a precisely calibrated pendulum device due to its weight the pendulum swings through an arc and turns the sample from a previously incised slab Sample is on one side of the pendulum and on the other Side held by a fixed link. The Snergieverluet

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the pendulum is indicated by a pointer »The scale value efine function of the sum of tearing the sample required

This method is for classifying the relative tear strengths various plastic films and thinner Pollen of comparable thickness valuable

The method used to measure peel strength is in ASTM D 903-49 "" Peel or Stripping Strength of Adhesives ". This test method can be summarized as follows will:

The peeling activity depends on the load the Varklebungslinie? which is necessary to dated an item others on the bonded surfaces at a separation angle of about 180 ° and at a separation speed of 15-2 cm increasingly su separate every minute «. It is expressed in grams per centimeter of width · The measurement of the eum peeling off the IiaminatB required force is carried out using a Claw Trermicaachine with constant speed The rehearsal is held in such a way that one track turns into a feat fixed claw clamped and the other track in one with a claw connected to a movable link is clamped "

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The force required to pull it off is indicated by a pointer. In this way, instead of the medium Abeo half strength determines the maximum peel strength.

You results of these various exams are in the Table A compiled.

Table A.

Peel resistance against bite resistance uus uniaxially oriented sample intermediate layer

compressed (no intermediate layer)

Polyethylene
Polyethylene
Polyethylene
Polyethylene "

Kautscthuk'gwlachenschl oh ten

6 butyl rubber (Staudinger molecular weight about 50,000)

7 butyl rubber (Staudinger molecular weight about 40,000)

8 polyisobutylene (Staudiager-Holo = gross weight about 9,000)

9 ethylene propylene rubber (Mooney-Viecosity about 40)

TO EthylenrPropylen-iCautachuk (Mooney viscosity around 70)

11 no intermediate layer

(pressed film treated with chlorine)

▼ on cross laminates
Polie
Peeling travel
firm-firm
speed in speed in
«/ Cm width κΑ \ ι 19.7 ) 0 but
<19s7 * 7.09 197 ... 5.12 256 4.73 374 4.13 394 7.09 295 8.86 169 7.9 193 7.9 108 12c2 79 13.6 59

BATH ORIGINAL

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Consideration of the above-mentioned rules makes it impossible that at very low half-strengths, such as those in the area of clay, just larger than a size of up to about 19.7 g / o * width, a maximum of about 19 " 7 % Jf. reach.

With a peel strength of 394 g / om width "Ban gets a much lower" but still acceptable dryness of 4t 13 Β / μ * The preferred peel strength "tlgJc © it" 1 "range from 19" 7 to about 158 g / c »width su lie.

This method to improve the onward journey 8f «etl £ fceit is presumably applicable to all theraoplastieohen? oli «a, it is particularly valuable for such foils, see below his «which is normally used for VerpaokungSBweeke are »and are made of the following materials

Polyäthylenι Copolymers of ethylene and butene} Polyesterι Polypropylene; Polyvinyl chloride? and

Polyamide.

The method by which the different layers sur Herat of the laminated structure are connected to one another

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den »does not seem to affect the results. Dae immediate Compressing one foil bit of the next by electrical treatment or ohior treatment of the surfaces can produce perfect results.

Also the immediate lamination of one full to the next duroh Hitee and pressure welding of the neighboring ones Laying at a temperature below the melting point of the film material, which is used for a bonding process to achieve without loss of organization »has see as Proven to be satisfactory. It was found that a modification of the pollen surface by electrical treatment or chlorine treatment, the welding at these temperatures Doors below the melting point supported · Various Binders that can also be used with the gate part, are for example:

Isobutylene-Isoprene-Misohpolymerlsat} Polyisobutylene! Ethylene propylene terpolymer ··, t j Ethylene «propylene ^ Hisohpolymerlsatι

a ie-1 ₉ 4 polybutadiene {

Styrene-butadlene copolymer

atactic polypropylene} and

Polybutene.

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It is obvious that the invention can be carried out in very different ways «and that none of the
Embodiments deviate from the nature of the invention and go beyond its scope. The invention is therefore intended to be limited only by the following claims and not by the preceding description.

VI

Claims (8)

Claims 1. Foil structure with improved tear resistance, thereby characterized in that it contains at least two oriented thermoplastic films that are interrelated in the manner are laminated so that the orientational lines of the said Sinssel foils are at a certain angle to one another and that the force required by the adjacent film of the laminated structure is less than 394 g / cm width » 2 * film structure according to claim 1 “characterized in that the individual foils are uniaxially oriented » 3 ' film structure according to claim 1 or 2 _P, characterized in that the orientation lines of adjacent film layers • te »lie at an angle of approximately 90 ° to each other. 4 = film structure according to claim 1 or 2, characterized in that the for peeling off one film from the adjacent Foil of the laminated structure required force in the range of about 19 »? up to 158 g / cm width is » 009886/1754 5 «film structure according to claim 1 or 2, characterized in that the thermoplastic material is a polyethylene; a copolymer of ethylene and butenej a polyester} a polypropylene; a polyvinyl chloride! or a polyamide. 6. Film structure according to claim 1 or 2, characterized in that the lamination bond by partial pressing together is achieved between the neighboring Foilsohiohten. 7. Foil structure naoh claim 1 or 2, characterized in that that the lamination bond by welding is more adjacent Foil layers is achieved by means of heat and bridge. 8. Foil structure according to claim 1 or 2, characterized in that since β s is the lamination bond through Yersohweiden of neighboring Foil soles by means of heat and pressure at a temperature below the melting point of the thermoplastic Material is achieved. 9 pollen structure according to claim 1 or 2, characterized in that that the lamellar bond through the use of an intermediate layer is obtained from one of the following binders? Isohutylene-isoprene misoh polymerizatef polyisobutylene; Xthylene * · - 13 - ■ -. 009885 / 17S4 Propylen-ferpolyaeriaatj Xthylen-Propylen-Miocbpolyaeriaat j cis-1 ^ -Polybutadiene / Styrene-Fatadiene-Miiohpolyaerieat; atactic polypropylene and polybutene. © AD ORIGINAL - 14 - 009885/1754