DE1494187A1 - Synthetic paper and process for its manufacture - Google Patents

Description

PATENT LAWYERS 1 A Q Λ 1 ß?

DR.-ING. BY KREISLER DR.-ING. SCHÖNWALD DR.-ING. TH. MEYER DR. FUES DIPL-CHEM. ÄLEK VON KREISLER DIPL-CHEM. CAROLA KELLER DR.-ING. KLOPSCH

COLOGNE 1, DEICHMANNHAUS

September 10, 1968 Ke / Br.

(M 49 351 IVb / 39b)

Montecatinl Societa Generale per I ¹ Indus tr ia I-iineraria e Chimica, 1-2 Largo Guido Donegani, Hailand (Italy) .

Synthetic paper and process for its manufacture

The invention relates to synthetic paper based on it of crystalline polyolefins, in particular of isotactic polypropylene, made with the help of stereospecific catalysts have been manufactured.

In the Italian patent specification 564 919 is a method described for the production of synthetic paper from crystalline polypropylene, after which at a temperature below I70 C solutions of polypropylene in a suitable solvent, which are spread out in thin layers, are evaporated, with the polypropylene solution on ground supports or sprayed onto polypropylene films.

It has now been found that it is possible to obtain a printable paper which is particularly suitable as a drawing paper is when one uses mixtures of crystalline polyolefins, especially polypropylene, with the addition of inorganic substances pressed into films in the presence or absence of additives such as stabilizers, dyes and the like.

809901/0791

Ν · υβ documents (Art 7, Section I, Paragraph 2, No. 1, Clause 3 of Andwunom ··. V. 4.9. 1.967)

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The invention accordingly provides a synthetic one Paper which is characterized in that it is essentially made of crystalline, especially isotactic, polypropylene and calcium carbonate, kieselguhr or sodium silicate consists.

It is made by taking the crystalline, in particular isotactic polypropylene and calcium carbonate, kieselguhr or sodium silicate-containing mixtures Temperatures between 200 ° and 35O ° C, preferably between 210 ° and 260 ° C, pressed into films and stretched in a manner known per se.

In order to obtain a drawing paper having the desired transparent properties, the inorganic compounds must be in the form of granules which are insoluble in the molten polypropylene. The calcium carbonate and sodium silicate granules have a diameter between 1 and 100 / U. Since, s pre-pressing of the mixtures is carried out at the temperatures mentioned in a screw press, the ¹ and 3 now, preferably, provides a layer thickness of the film is between 0, J 'between 1 and 2 mm. the pressed film is subjected to stretching in the plastic phase (stretching ratio of 1: 2 to 1: 6) and then preferably quenched in a water bath at 0 ° to 30 ° C. at a distance of 2 to 10 cm from the press head .

The synthetic paper according to the invention is useful not only as drawing paper but also for manufacture of nautical maps, geographical maps, maps for military purposes and for documents, books or notebooks, also for packaging purposes, home furnishings, coatings on electrical cables and the like. It is special resistant to abrasion, bending and erasure.

It is possible to draw on the new paper and'the Drawings by, for example, cyanography or Elio-

8099D1 / 0796

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to reproduce graphics; on paper can also be with various types of inks, such as iron gall inks or tint inks, indelible inks, security inks, Copier inks, typewriter inks, printing inks, stamp inks, metallic inks, diplomatic inks and inks, obtained from dye solutions and polypropylene derivatives according to the applicant's earlier patents prints or writes.

example 1

It is a mixture of oO kg of polypropylene obtained by means of stereospecific catalysts, and an intrinsic viscosity / hJ7 - 2.55, measured in tetrahydronaphthalene at 1J55 ° C an ash content of 0.079% and a residue after heptane extraction of 92.5 '/ ■ has produced 20 kg of powdered calcium carbonate with a particle diameter between 1 and 7 / rev. 500 g of 4, ^ 1'-thiobis-J-methyl-o-tert-butylphenol are added to this mixture as a heat stabilizer.

The mixture is powdered and pressed in a screw press with a maximum screw end temperature of 230 ° C and a temperature of the extruder head of 240 ° C. The opening of the extruder gap is 1.5 mm and the compressed film, stretched in the plastic phase, has a thickness of 200 / rev. The compressed film is cooled in a water bath which has a temperature of 15 ° C. and is arranged at a distance of approximately k cm from the extruder head.

In this way, a film which is very suitable as a drawing paper is obtained.

Example 2

Ea is a solution of 95 kg of polypropylene, which was obtained with the aid of stereospecific catalysts and an OrenzvlskOBität £ fy_7 = 2.50, measured in tetrahydrofuran

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naphthalene at 135 ° C, an ash content of 0.0 29 fo and a residue after the heptane extraction of 95 * 5 % , and prepared 5 kg of powdered sodium silicate with a particle diameter between 1 and 7 yu. 500 g of lauryl thio-di-propionate are added to this mixture as a stabilizer. The mixture is then pulverized and pressed in a screw press with a maximum Schneckenendtemperatur of 230 ⁰ C and a temperature of the extruder head 240 ° C. The opening of the extruder gap is 1.5 mm, and the compressed film, stretched in the plastic phase, has a thickness of 200 μm. The compressed film is cooled in a water bath which has a temperature of 15 ° C. and is arranged at a distance of approximately 4 cm from the extruder head.

A film is obtained which is very suitable as drawing paper.

Example 3

There is a mixture of 95 kg of polypropylene, which was obtained with the help of a stereospecific catalyst and an intrinsic viscosity £ jnj = 2.5, measured in tetrahydronaphthalene at 135 ° C, an ash content of 0.0 29 % and a residue after the heptane extraction of 95 * 5 % and produced 5 kg of powdered diatomaceous earth with a particle diameter between 0.015 and 0.020 ai . 500 g of lauryl thio-di-propionate are added to this mixture as a stabilizer.

The mixture is then pulverized and pressed in a screw press with a maximum Schneckenendtemperatur of 230 ⁰ C and a temperature of the extruder Kopies of 240 ° C. The opening of the extruder gap is 1.5 mm, and the compressed film, stretched in the plastic phase, has one

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Thickness of 200yu. The compressed film is placed in a water

ο cooled bath that has a temperature of 15 C and is in a distance of about 4 cm from the extruder head is.

In this way, a film that can be used as a drawing paper is obtained suitable is.

809901/0796

Claims (1)

P a t e η t a η s ρ r ti c h e 1.) Synthetic Pqier, characterized in that it is ira essentially of crystalline, in particular of isotactic polypropylene and calcium carbonate or kieselguhr Consists of sodium silicate. 2.) Synthetic paper according to claim 1, characterized in that that it is the anorganic clien pullst of fe in the form of grains with a diameter between 1 and 100 / U. 5.) Process for the production of the synthetic paper according to Claim 1 or 2, by compression of the mixtures containing the polyolefin and the fillers and then Stretching, characterized in that the crystalline, in particular isotactic polypropylene and Mixtures containing calcium carbonate, kieselguhr or sodium silicate at temperatures between 200 ° and p50 ° C, preferably between 210 ° and 26o ° C, pressed into films and stretched in a known manner. 809901/0796 Documents (A _11. > _S ι Paragraph 2 NM ORIGINAL INSPECTED