DE2112030A1 - Paper-like polymeric films and processes for their manufacture - Google Patents

Description

Dl MOLLEIt-BORC DtPL-PHYtDLMANITZ DIPL-CHCM. Dl. DEUFEL DIPL-INQ. PINSTEKWALD DiPL-INQ. GRXMKQW

PATENT LAWYERS «.

2112030 Dek / th - α? 1090

TOYO BOSEKI KABUSIiIKI KAISHA

3 _t Do ^ ima Hamadori 2-chome, Kita ~ ku, Osaka,

Japan

Paper-like polymeric films and processes for their

Manufacturing

Priorities: Japan from I3. March 1970, No. 21 823/70

Japan vcia September 16, 1970, No. 81405/70 Japan of September 18, 1970, No. 82074/70 Japan of December 26, 1970, No. 125389/70

The invention relates to paper-like, thermoplastic, polymeric films and a process for their manufacture. In particular, the invention relates to paper-like products Film, which is a mixture of a polypropylene resin and Polyethylene resin and, if necessary, polyethylene resin comprises, for which a finely divided, inorganic substance is added, the film in at least one direction is oriented and inner, small empty spaces and a finely fibred, has a rough surface, the invention relates to the production of such a paper-like one Foil.

It is known to use a polymeric Forsak body, which has internal, contains small voids or pores by incorporating a foaming agent into an organic polymer and allowing it to take effect foaming during the molding process

"f * fa * ti: r

to manufacture. However, a molded body obtained by such a procedure is not uniform in terms of pore size ντΛ has poor mechanical properties. Further, from Japanese published patent application Mr. 15560/1969 a mode of operation for the production of stretched film containing hollow spaces or forums is known, in which a film made from a mixture of a chewing school-like substance is stretched from a thermoplastic material so that inside the film f there are cavities baw . Pores are formed. lia rubber-like substance is used is the

The resulting porous film, although good in terms of resilience, has defects, namely that it tends to shrink and that it is poor in terms of dimensional stability. Also, it is known to manufacture a paper-like polymeric film by stretching a film made of a mixture of an inorganic substance and a polypropylene into a plastic state and then rapidly quenching this film, see Japanese Known Patent Application No. 11825/1963 · However it is difficult with this procedure to stretch the film evenly. In addition, the resulting paper-like film is only roughened on the surface and has no internal, small cavities or pores. Therefore, this paper-like film is poor in terms of strength, has no elasticity and does not have sufficient characteristics with regard to the ability to be touched, ie the ease of making markings with conventional writing instruments such as pencil and pen .

Ee is therefore an object of the invention to provide a paper-like ©., Polymeric film containing the desired, papierKhnlidbja

- c -

Properties, ζ. B. excellent dimensional stability, Opacity (poor permeability compared to natural ones Light rays), writability and printability.

It is also an object of the invention to expire Production of such paper-like, polymeric films au deliver.

Further objects of the invention will be apparent from the following Description.

The invention provides a paper-like, polymeric film, soft one-composition containing at least 5 wt. of a propylene or ethylene / propylene copolymer with an XtLyIen content of 0-1.5 Hol.?*, b -? O view.Jt one Polyethylene or ethylene-propylene copolyceiasates with a Frcpylengetoalt of O - JO Kcl «% and 5-50 wt.% It divides a solid, inorganic substance with a Average particle diameter of Q, 1 - 1b iua, the 3Ji the Pclie is dispersed, comprises, wherein the "film in at least Oriented towards one direction is the internal, small one Cavities bsv. Pores and a smoothly filtered, rough surface having, the content of cavities or pores or voids is 40 - JQO ecu / 100 g and the permeability; of natural rays of light is not higher than $ 70.

If necessary, the addition can be 5> - 60 Ew.% Of a styrenic resin.

According to the invention, the above "described, paper-like, polymeric film produced by "ine SusamaeasttS" uae

is made, plural marriage at least 5% by weight of a polypropylene or ethylene / propylene copolymers with an ithylengeha.lt from 0 · - 15 mol.%, 5-70% by weight of a polyethylene or ethylene-propylene copolymer with a propylene content from 0-30% by weight (and optionally 5-60% by weight of a styrenic resin) and 5-50 wt.% of a finely divided, solid, inorganic substance with an average particle diameter from 0.1 - 15 mm contains, ._ ,. the Z composition or the mass is formed into a film and then the film is stretched in at least one direction.

The thickness of the film according to the invention is 20-1500yuta. As used herein, the term "fibrilates" means that the surface of the film is in such a state on microscopic observation that continuous, fine threads have grown together to form a rough surface.

The polypropylene or ethylene / propylene copolymer to be used in the invention has an ethylene content of 0-15%; such a copolymer is also referred to below as propylene-like resin. A preferred propylene-like resin is a crystalline resin in which the non-extracted portion is at least 60% by weight and preferably more than 70% by weight and preferably more than 70% when 10 g of a powder of this polymer is extracted with 200 ecm of n-heptane for 6 Ii in a Soxhlet apparatus Weight% is. If the ethylea content in the propylene-like resin exceeds 15% by weight, the film would tend to shrink and become poor in terms of dimene ion stability. The heat index of the propylene-like resin should not exceed 15 g / min, since if this value is exceeded, the deformability and the stretchability of the film become poor. The melt index is measured according to the * »# of JI3-K6760 (Japanese industrial standard),

1C9839 / 181B

and it is represented by the extrusion length (weight) which is ^{pressed out of propylene-like resin melted to 2JO 0} C under a pressure of 2 160 g for 10 minutes through a nozzle with an opening diameter of 2.09 mm and a length of 168 mm. The content of the propylene type resin in the composition should be at least 5% by weight.

The polyethylene or ethylene-propylene copolymer, which is also referred to below as ethylene-like resin and is to be mixed into the propylene-like resin, has a propylene content of 0 to "30 Mol.56. A preferred ethylene-like resin is a crystalline resin , in which the non-extracted portion when extracting 10 g of the powdered polymer with 200 ecm n-heptane for 6 hours in a Soxhlet apparatus is at least 60 Qev% and preferably more than 70 Qev.% High density polyethylene If the propylene content in the ethylene type resin exceeds 30 vol% , the film is likely to shrink and tend to show poor dimensional stability.

This ethylene-like resin is used in an amount of 5 to 70 preferably 15 to 4-5% by weight, each based on the total composition, mixed in. Palis the narrowness of the ethylene-like Resin in the overall composition to form the If the film is less than 5 wt. #, It will be difficult to obtain the obtained film at high speed evenly stretch. If the amount of the ethylene-like resin is 70% by weight exceeds, the mechanical properties of the film become poor.

- 5 -

109839/1615

It is preferred that the melt index of the ethylene type The resin is lower than the melting index of the propylene-like resin. J · smaller the ratio, i.e. H. less than 1/10, the rougher the surface that has arisen Foil so that it tends to lose its sheen. The greater the ratio, i. H. is greater than 1/5, the smoother is the surface of the resulting oil, so that it is to it tends to maintain glans.

The composition may also contain a styrenic resin in addition to the above-described mixture of propylene-type resin and ethylene-type resin. "The addition of" a special styrene material improves the rigidity and workability of the film ". Examples of such styrenic resins are polystyrene, acrylic nitrile / butadiene / styrene copolymers, acarylnitrile / Btyrolcopolyaerisat and Butadiene / Styrenecopolymerisat · Busatyrene-like ears should have a melt index of 0.01 to 10 g / 10 "in, preferably 0.1 to 5" 0 g / 10 min, consumed at a temperature of 190 ⁰ O below one Load of 2.1 kg gontß lß35H-l> -1258-65T. In particular, a polystyrene with a density of 1.0 to 1.2 g / ca *, obtained according to JXS-X-6871, is preferred.

The styrenic resin is mixed in in an amount of 5 to 60 parts by weight, preferably 10 to 45 parts by weight, depending on the composition of the gel. If the slope of the styrenic ilaraea exceeds 60 % by volume, the aeohanic properties and the heat resistance of the film become poor, fine voids are no longer formed in the film, and the writability tends to deteriorate noticeably.

109839 / 161S

The composition or mass for forming the film according to the invention is intended to be an inorganic substance in the form of contain finely divided solid particles. Examples of such inorganic substances are calcium carbonate, calcium oxide, Silicon dioxide, titanium dioxide, aluminum oxide and aluminum sulfate. Calcium carbonate is particularly preferred. The mean pitch diameter the inorganic substance should be 0.1 to 15 µm, preferably 0.5 to 10 µm. If the The particle diameter of the inorganic substance is less than 0.1 µm, it would be difficult to find small voids to be formed distributed over the film, d. H. from the surface to the inside of the film. If the particle diameter If it exceeds 15 / um, the lockability of the humiliated.

Preferably 5 to 50 wt.%, Particularly preferably 10 up to 25 Gew.fr, in each case based on the total composition. such an inorganic substance is mixed into the film-forming composition. If this length is less than 5 Geu. ^, Voids or pores are not sufficient formed in the foil. On the other hand, if the content of such an inorganic substance exceeds 50% by weight, it would it will be difficult to stretch the film.

The resinous material (propylene-type resin and ethylene-type resin with or without styrene-type liars) and the inorganic substance can be any known ones. appropriately mixed. However, it is particularly preferred to mix them together in the form of powder.

The mixed composition is then preferably extruded aiii aui 220 200 to 350 ⁰ O, ⁰ to 280 C, and melted in the form of a film. Then the extruded, hot

10 9 8 3 9/1615

Cooled film on a chill roll or in a liquid at 0 to 150 ⁰ C, preferably 20 "to 110 ⁰ O. They method and apparatus for forming a film and the cooling thereof are inherently so well known that no further explanations on this required are.

Then, the film for orientation in, at least preferably, stretched one direction at a temperature of 40 to a 1? 0 ⁰ C, at a temperature of 70 to 150 ⁰ C. In the case of stretching in one direction, the film is stretched 3 to 20 times, preferably 5 to 10 times, the length. As a result of this stretching, small cavities or pores in the form of spindles, which have the long axis practically parallel to the direction of stretching, are formed in the film and are completely distributed over it. The length of the long axis of such a cavity or ' Pore is 2 to 150yU.ni, as measured on the micro * photograph. The amount of formation of such voids tends to increase with the increase in the stretching factor or ratio and with the decrease in the stretching temperature be in a fibrillated state. The average depth of such a fibrillated, rough surface layer is 0.3 to 5 µm.

In the case of biaxial stretching of the film, it is preferred to stretch it 8 to 45 times, preferably 10 to 35 times, cte: r to stretch the original area. In this Trap, the formation of cavities or pores tends to increase as the factor or ratio of stretching increases. the formed cavities or pores are practically spherical

1 09839 / 161S

and have an average diameter of 4 to 250 Aim. Sometimes and in some places the voids or pores mm4 * * are continuous and not independent. About that in addition, the fibrillation on the film surface is promoted more by the biaxial stretching than by the monoaxial stretching Hedges so that the average depth of such a fibrillated layer is 0.5 "to 10 µm.

The biaxial stretching can be carried out simultaneously or sequentially. The above-mentioned stretching temperature and the above-mentioned stretching ratio are generally applied to simultaneous biaxial stretching. In the stepwise execution of the biaxial stretching the film first at 40 to a 1? 0 ⁰ G to 4 to 6 times the original length in one direction and then at a higher temperature than the first stretching but below 220 ⁰ C and is the 5 "to 7 ~ area of the original length is stretched in a different direction, which is practically at right angles to the above-mentioned first stretching direction. In this case, it would be necessary to carry out the second stretching in such a way that the already during voids or pores formed during the first stretching are not destroyed and the film is not torn.

The stretched film can furthermore be ^{heat-treated at 150 to 210 °} C. for 1 second to 3 minutes in order to reduce the thermal shrinkage of the film and to improve the dimensional stability.

Optionally, a surface activation treatment, e.g. B. a corona discharge or a flame treatment the film can be applied so that the writability with an aqueous ink and the adhesion with any, other substance can be improved. Furthermore

10903.9 / 1018

the foil can be embossed on the surface or they can "be coated.

, The composition for the production of the film can also contain a small amount of additives such as a stabilizer, antistatic agent, dye, or pigment.

The paper-like film obtained in this way contains small or fine, internal cavities or forums with a diameter of 4 to 250 μm. The void content is 30 to 300 ccm / 100 g. W The film has a fibrous, rough surface portion, the depth of which is 0.5 to 10 λιτά . The film is oriented, has a high elasticity and the permeability to natural light rays is not higher than 70%. If the transmittance ^{exceeds 70 c} / a , the gloss is very high and the writability is not so good. The film has excellent dimensional stability

xst
and / evenly fibrilated on the surface. The foil

is just as opaque as paper and has excellent writability and printability. In particular it's one Biaxially oriented film is preferred, since the difference in mechanical and physical properties is long and cross direction is small. In addition, a film made from a composition in which styrenic resin is mixed, the property of so-called "rigidity" and therefore it is in feeding to a machine (the ability to be introduced into a Machine) better than a film lacking such a styrenic resin, and it can with clear outlines be printed without being swollen by the color γλι.

The film according to the invention can be printed as a film, film for writing on, as a peel-off film and protective film for plywood

- 10 -

109339/1615

as decoration etc., film wrappings, for colored, printed film, insulating material, underlay material for deposits from the vapor phase, J? ⁵ olie suitable for printed layers of plywood or as packaging or wrapping material.

The paper-like film according to the invention can be coated on at least one surface with a biaxially oriented layer of polypropylene. Such a coated film is particularly excellent in overall glossiness, that is, a gloss of more than 3Ο ^ ό measured at 45 °, and it has practical value as a packaging film for high quality articles of manufacture, high quality cosmetic articles, etc. In addition, the adhesion is useful between the base layer and the top layer (made of polypropylene) is very high, so that no such peeling occurs even when attempting to peel off the surface layer with an adhesive tape (Scotch tape Ho. 59, manufactured by Minnesota Hining and Manufacturing Company, USA) In addition, a polie coated in this way has mechanical properties which are essentially comparable to those of a conventional, transparent, biaxially stretched polypropylene film.

In the production of such a coated sheet or such a coated film, the extruded and cooled film (in front of the basin), if it has been manufactured according to the procedure described above, is coated with a polypropylene layer on one or both surfaces. For example, polypropylene is heated above the melting point and melted onto one or both surfaces of the above-mentioned plastic film. Alternatively, an unstretched polypropylene film is heated and applied to one or both surfaces of the base film

under a pressure of at least 3 kg / cm and preferably

- 11 -

109839/1615

from $ to 20 kg / cm, with one roller, ζ. Β. laminated (stacked) on a rubber roller. In particular, the method of layering by melting is preferred. The polypropylene used here should have a degree of isotactic structure of more than 85 % and an intrinsic viscosity of 1.4 to 4 dl / g, measured in a tetralin solution at 135.degree.

Then, the coated or laminated film is consecutively or simultaneously biaxially times 7Ö-at a! Temperature of 80 to 170 ⁰ O, preferably from 110 to 160 ⁰ O, wherein a "ratio of 8 to and preferably multiple 55-by 10-bis When stretching, fine or small voids or pores are formed in the base sheet, and the covering layer film made of polypropylene is biaxially oriented, so that a sheet having excellent surface gloss is obtained.

The invention is explained below with the aid of examples, reference being made in part to the drawing; in the drawing are:

Fig. 1 is a graph showing the relationship between the amount of calcium carbonate and the void content and shows the light transmission of the resulting film; and

Fig. 2 is a graph showing the relationship between the amount of calcium carbonate and the vapor permeability and represents the oxygen permeability of the resulting film.

- 12 -

109839/1615

In these examples, various properties of the products, namely the paper-like films, were determined as follows Regulations determine:

(1) Transmission to natural light rays: JIS-K6714- (JIS β Japanese industrial standard)

(2) Tensile strength and elongation:
JIS-Z17O2

(3) Tear resistance of the film edge: JIS-K6732

(4) Average depth of rough surface:

The depth of the irregularities was measured with a ruler at 50 different points on the film surface measured and the average value thereof was calculated.

(5) Thermal shrinkage:

The rate of change in dimension when the film is immersed in a silicone oil at 100 ^° C. for 1 min

(6) Empty space or void or pore content: Calculated according to the following equation by measuring the apparent density d of the film:

Pore content * 100 (1 -

wherein

100

where J ,,, jρ »Jii and fu are the respective densities of propylene-like resin, ethylene-hard resin, styrene-like resin and inorganic substance and M,., M«,

- 13 -

109839/1615

M, and TL the respective proportions of the propylene-like Resin, ethylene-like resin, styrenic Hai'zes and the inorganic substance in the film-forming composition.

(7) Rigidity:

Measured at 20 ° at a curved angle and at 10 mm by changing the thickness with pressure; Foil rigidity tester No. 5S0 by Toyo Seiki KabusLiki Kaisha.

(8) Machine accessibility:

It became the number of errors that occurred when feeding of synthetic paper (paper-like, polymer film) at a speed of 4000 sheets / h of an automatic feeder for a printing machine were rated as follows:

A »less than 1 %
B. 1 to 10 %
0 »10 to 30%
DR more than 30 %,

(9) Gloss:
JIS-Z874

(10) Oxygen permeability:
ASüM-D-1436-63

(ASIM «American standard regulation)

(11) Vapor permeability
JIS-Z-0208

example 1

A mixture in which the content of polyethylene (melt index «■ 0.06 g / 10 min) on 20 wt, # was fixed, but the

- 14 109839/1615

Contents of polypropylene (melt index 2 g / 10 min) and calcium carbonate (average particle diameter 1.2 μm) were varied as shown in Table I, was ^{melted at 250 0} O and extruded in the form of a film, which was cooled on a chill roll at 90 G to get a film with a thickness of 900 jfim. This film was stretched 5 times its length in the longitudinal direction between rollers heated to 155 ° G at different peripheral speeds. Then, the film was ^{fed into a tenter at 160 °} G and stretched 8 times the width in the transverse direction to obtain a film having a thickness of 25 to 50 Aim. Moreover, the film was, while being kept in the tenter clips, 20 lake in a hot air oven at 150 ⁰ G heat treated.

The relationship between the pore content and the permeability of natural rays of light and the content of calcium carbonate In the resulting film, ″ is shown in FIG. 1. Curve I gives the void content and curve II gives the transmittance to natural light rays again. As can be seen from FIG. 1, the void content of the film increases as the content of calcium carbonate increases au, and the light transmittance is lowered. However, if the amount of calcium carbonate exceeds 30% by weight, the Light transmission not noticeably lowered. When the calcium carbonate content exceeded 50% by weight, the hedges became the slide difficult. Furthermore, it can be seen from Fig. 1 that with a calcium carbonate content of 0% the empty space content is 37 ecm / Was 100 g. This was a consequence of the ίτ TL regularities On the surface of the film and within the film, no voids or pores were formed.

- 15 -

109839/1615

Fig. 2 shows the relationship between the vapor permeability and the oxygen permeability and the amount of Calcium carbonate. Curve III shows the vapor permeability and curve IV shows the oxygen permeability. How yourself from Fig. 2, both the vapor permeability and the oxygen permeability increase as the ■ amount of calcium carbonate. However, if the amount of calcium carbonate is less than 20 wt%, the rate of increase is weak. If the calcium carbonate content is more than 20% by weight the rate of increase of these permeabilities becomes large.

The mechanical properties and the thermal properties of the obtained paper-like sheet using the composition with 25 wt.% calcium carbonate, 55 wt.% polypropylene and 20 wt.% polyethylene are in shown in Table IV.

Examples 2 to 7

A mixture in which the content of an ethylene / propylene copolymer (Molar ratio 90/10) with a melt index of 0.1 g / 10 min at 40% by weight, but the

of the content of a propylene (melt index 2 g / 10 min) and / calcium

carbonate (average particle diameter 1.2 Aim) were varied as shown in * Table I, was ^{melted at 250 0} C and extruded in the form of a film, which was ^{cooled on a chill roll at 90 0} C, to form a film with a thickness of 900 µm to obtain. The film was stretched five times its length in the longitudinal direction between rollers heated to 135 ° C. at different peripheral speeds. Then the film was inserted into a tenter at 155 ^° C. to make it 8 times the width in the transverse direction

- 16 -

109839/1815

Zru stretch and a IPoIie mn with a thickness of 30 to 50 to obtain. Furthermore, these I'olie was, while being kept cling in the tenter, 20 lake in a hot air oven at 150 ⁰ O heat treated.

The relationships between void content, average depth of rough surface and light transmission and the Calcium carbonate content in the resulting film shown in Table I.

Calcium-
carbonate
lot (%) Tabel I. Light transmission
nonchalance Average
depth of the rough
Surface (iim) at
game 0 Classroom
salary
ccm / 100 g 93 0.1 2 5. 28 69 0.5 3 10 41 39 0.7 4th 20th 70 24 1.0 5 30th 103 9 0.9 6th 40 162 5 1.1 7th 211

As can be seen from Table I, when the amount added increases. Calcium carbonate amount is the void content the film to and the light transmission of natural Light off. It should also be noted that the film with a calcium carbonate content of 55 wt. ^ O im The course of the stretching was torn. The mechanical properties and the thermal properties of paper-like i'olie in Example 5, in which the amount of calcium carbonate 20% by weight are shown in Table IY.

- 17 -

109839/1616

Comparative example 1

A mixture of 40% by weight of a polypropylene (melt index 2 g / 10 min), 40% by weight of an ethylene / propylene copolymer (ethylene content 40%) and 20% by weight of calcium carbonate (particle diameter 1.2 μm) is added 240 ⁰ C melted and extruded to obtain a film with a thickness of 900 iim. This film is stretched and heat-treated under the same conditions as in Example 2. The mechanical properties and the thermal properties of the resulting film are shown in Table IV.

Examples β to 13

A mixture in which the gel content of a polyethylene (melt index 0.06 g / 10 min) is held at 40% by weight, but the content of an ethylene / propylene copolymer (wood ratio> 5/95) with a melt index of 3 β / min and were (/ average particle diameter 1.2 microns) varies 10 of calcium carbonate as shown in Table II shown vnirde melted at 250 ⁰ C and extruded in the form of a film which vnirde cooled on a cooling roll at 90 ⁰ G, a film with a strength of 900 to obtain. This slide. was the stretched at different circumferential speeds 5-i'ache the length in the longitudinal direction between heated to 130 ⁰ C rollers. Then, the film was placed in a tenter at 155 ° C and stretched 8 times the width in the transverse direction to obtain a film having a thickness of 25 to 50 µm. Further, this film was was gehalben while the Spannrahmenklaminern, 20 lake in a hot air oven at I50 ⁰ C heat treated.

- 18 -

1098 3 9/1615

/ rs

The relationships between void content and light transmission and the content of calcium carbonate in the obtained films are shown in {Table II.

Table II Light through
nonchalance
(#) Calcium-
carbonate
men ^ e (%) Delivery room
salary
Cccm / ΙΟΟκ) 92 O 31 68 5 42 37 10 74- 21 20th 105 8th 30th 171 5 40 240

example

As can be seen from Table II, as the amount of calcium carbonate blended increases, the void content increases the resulting film and the transparency of natural radiation decreases. It should also be pointed out that the film with the addition of calcium carbonate in a henge of 55 wt / was torn in the course of stretching. the mechanical properties and the thermal properties of the film of Example 11, in which the mixed The amount of calcium carbonate was 20% by weight, are shown in Table IV shown.

Examples 14-19

A mixture, in relation to the content of an ethylene / propylene copolymer (hol ratio «= 90/10) with a smelting index

- 19 -

109839/1615

0.1 g / 10 min to 40 wt. Was held fa, however, the contents of an ethyl en / PxOpylencopolymerissbes (tiolverhältnis = 5/95) having a melt index of 2 g / 10 min, and calcium carbonate (Durchschnittsteilchendurchinesser 1.2 / um) were varied as shown in Table III, was ^{melted at 250 0} C and extruded in the form of a film, which was cooled on a cooling roll at 90 ° G in order to obtain a film with a thickness of 900 μm. Five times the length in the longitudinal direction was stretched into this film between rollers heated to 135 ° C. at different peripheral speeds. Then the film was introduced into a tenter frame at 155 ° C. and stretched aas o times the width in the Quex * direction to obtain a film with a thickness of 30 to 10 μm. to receive. Further, while the film was held in the tenter clamp, it was heat-treated in a hot air oven at 150 ° C for 20 seconds. The relationships between the void content and the light transmittance and the amount of calcium carbonate added to the film obtained are shown in table III.

table III

at
game Calcium-
carbonate
amount (^) White space
salary
Cccm / ΙΟΟκ) Light through
nonchalance
(%) 14- 0 26th 92 15th 5 41 70 16 10 55 4-9 17th 20th 77 26th 18th 30th 123 18th 19th 4O 180 12th

As can be seen from Table III, as the amount of calcium carbonate mixed in increases, the void content increases

- 20 -

109839/1616

the film increases and the light transmission decreases. It should also be noted that when calcium carbonate is mixed in in an amount of 55% by weight, the film in the course of the
Stretching broke. The mechanical properties and the
thermal properties of the resulting film des
Example 17 _} in which the amount of calcium carbonate blended was 20% by weight are shown in Table IV.

Comparative example 2

A mixture of 40% by weight of an ethylene / propylene copolymer (molar ratio = 5/95) with a melt index of
2 g / 10 min, 40% by weight of an ethylene / propylene copolymer (ethylene content 40 mol%) and 20% by weight calcium carbonate
(Particle diameter 1.2 do) was ^{melted at 240 °} C. and extruded to obtain a film with a thickness of 900 μm. The film was then introduced into a tenter frame at 140 ⁰ O and under the same conditions vr ± e in
Example Ί4 stretched and heat-treated. The mechanical
Properties and thermal properties of the obtained film are shown in Table IV.

trans
versal Table IV Examples
5 11 ' 623 17th Comparison
examples
1 2 105 longi
tudinal 1 640 385 570 151 86 properties trans--
versal 661 397 71 532 114 39 Tensile strength longi-
(kg / cm2) tudinal 405 65 59 80 59 31 80 71 38 48 Tensile elongation
(%) 88

- 21 -

109839/1815

Table IV continued

Features Examples Comparative

EXAMPLE 1 5 11 17 1 2

Edge _{tear Longi- ΛΛη}
strength tudinal ^{M /}
fi

verbal ^{1? 2 17} ° ^{181 257}

thermal

Shrinkage 2.2 2.1 2.4 2.9 23.0 21.4-

Examples 20 to 26

A mixture was prepared in which the content of a polyethylene (specific weight 0.96) with a melt index of 0.06 g / 10 min was fixed at 15% by weight, but the content of a polystyrene (melt index 0, b7 g / 10 Eixn) and of calcium carbonate (particle diameter 1.2 mm) as shown in Table V, the remainder being a polypropylene (intrinsic viscosity 2.1 dl / g) with a melt index of 2 g / 10 min. The mixture was melted at 250 ⁰ C, and extruded into 3? Orm a film which was cooled on a cooling roll at 80 ⁰ C to obtain a film having a thickness of 1000 to obtain lim. This film was stretched five times its length in the longitudinal direction between rollers heated to 135 ° C. at different peripheral speeds. Then, the film was stretched 8 times the width in the transverse direction to obtain a film having a thickness of 30-50 µm. Further, the film was wähx * end it was kept in tenter clips, 20 lake in a hot air oven at 150 ⁰ G hitziibehandelt. The parameters of the rigidity, the machine infiltration, the void content and the permeability of the film obtained

- 22 -

109839/1615

and the added amounts of polystyrene and calcium carbonate are shown in Table V

Table V

at
game End mixed (%)
Poly calcium
styrene carbonate 23 Stiff
speed Machine
to-
availability White space
salary
ccm / i00g Light through
nonchalance
(#) 20th ü 20th 0.51 G 101 24 21 30th 0.62 B. 61 29 22nd 10 50 ■ 0.71 A. 171 9 25th 10 20th 0.79 A. 270 .6 24 bO 20th 0.81 A. 43 50 25th 65 20th 0, GO A. 22nd 95 26th 20th 0.75 A. BO 28

As can be seen from Table V, as the Polystyrene narrows the stiffness higher and oils can be fed into the machine wiixi improved. If, however, the lOlystyrene content exceeds a certain value, the void content is nimrit j> .b. In fact, the film of Example 25 had a remarkably high quality low writability. The mechanical properties and the thermal properties of the film's Examples 26 are shown in Table VI.

Comparison example 3

A mixture of 15 wt. $ & A polyethylene (melt index 0.06 g / 10 min), 45 wt.% Of an ethylene / propylene copolymer (ethyl closely ehalt 40 Kol.%), 20 wt.% Of a polystyrene (melt index 0, 7 g / 10 min) and 20% by weight of calaium carbonate (partial diameter 1.2 μm) are melted at 240 ° C. and estruded to obtain a film with a thickness of 1000 μm. This film would be used under the same conditions

- 23 -

109839/1615

stretched and hit-treated as in Example 26. The mechanical Properties and thermal properties of the obtained film are shown in Table VI.

properties longitudinal
transversal example 26 comparative
example 3 Table VI Tensile strenght-
ο
(kg / cm) longitudinal 900
682 110
88 Tensile elongation (%) transversal 53 34 25th 38 thermal
Shrinkage (%) 5.5 19.0

As can be seen from Table VI, the film of the example according to the invention is better in mechanical properties and has a lower thermal shrinkage than that of Comparative Example 3

Example 27

A mixture obtained by mixing a polypropylene (melt index 2 g / 10 min), a polyethylene (melt index 0.06 g / 10 min) and titanium dioxide with different average particle diameters as shown in Table VII at a weight ratio of 60/20 was prepared _t 20 was melted at 250 ⁰ C and extruded in the form of a film which was cooled on a cooling roll at 90 ⁰ C to obtain a film having a thickness of 900 microns.

- 24 -

109833/1616

is

This film became p ~ times the length in the longitudinal direction stretched between rollers with different peripheral speeds. The slide was then placed in a tenter frame at 160 and stretched 8 times the width in the transverse direction to obtain a film having a thickness of 25 to 50 µm to obtain. The relationship between the white space content and the hackability of the film and the particle diameter of the titanium dioxide are shown in Table VII.

! Table VII

Particle diameter of [titanium dioxide (µm)

less than 0.1 0.1 to 10
10 to 15
more than 15

Empty space (ccm / iö0 ~ g)

less than 50 50 to 300
300

Eckbarlichkeit

excellent excellent good

Stretchable in the longitudinal direction, but not in the transverse direction

As SiOH results (Table VII, takes the void content or pore content of the film-to! When the Teibhendurchmesser of the titanium dioxide becomes greater, but if the particle diameter exceeds 10 in order, the void content reaches a practical equilibrium value and when it exceeds 15> in, is The film is difficult to stretch.

Ex everal 2 8 to 33

A sheet with a thickness of 900 µm was made from a mixture in which the content of calaium oxide (Average particle diameter 1.2yum) to 15 wt.? »

- 25 -

109839/1615

was recorded, but the contents of a polyethylene (Melt index 0.06 g / 10 min) and an ethylene-propylene copolymer (violet ratio = 5/95) with a melt index varied from 3 g / 10 min as shown in Table VIII vnirde. The film became 5 times the length in the longitudinal direction stretched between rollers with different peripheral speeds at 90 ° ö. Then the slide introduced into a tenter at 155 ° C and the G-x'ache the width in the transverse direction to obtain a S'olie stretched with a thickness of 35 to 50 lim. The relationships between the amount of polyethylene added and the void content, the transparency and the stretchability of the The times of correction are shown in Table VIII.

Polyäthjr 1 en-
lot (%) Tabel VIII Iieckbarl: eit at
game 0 White space
Cold
Cccm / 100 p;) Li rushes through
nonchalance
(G) uniaüglicii 2 B 5 6th 9o Well 29 10 4b 66 excellent 30th 30th 76 35 excellent 31 60 62 32 Well 32 ^r> 5 103 22nd not possible 33 - -

As can be seen from Table VIII, when the amount of polyethylene used becomes more than 1/10% , the transverse direction heckability remarkably decreases, and the mechanical properties of the obtained film become poor.

- 26 -

10 9 8 3 9/1615

Example ^ 4

A polypropylene with a melt index of 2 g / 10 min, calcium carbonate with an average particle diameter of 1.2 aiii and a polyethylene with a melt index of 0.06 g / 10 min were mixed in a weight ratio of 60:20:20. The hi coining vjurde melted at 250 ⁰ and G in! "Τ.rn a film is extruded which was gekülilt on a cooling roll at 90 ° C to form a iolie with a thickness of 500 to obtain üb. A molten at 240 ⁰ C polypropylene CIntrinsikviskosität 2.1 dl / g) was extruded and manufactured under a line pressure of GI ~ g / cm on a surface above the base film is laminated (coated). Then the same polypropylene was melt-laminated on the other surface of the base film under the same conditions. The strength o ^e d ^ei> ßberaugsschicht was 150 jam. Then, the laminated film was stretched 5 times the length in the longitudinal direction at """" and then it was stretched 8 times the width in the transverse direction at 155 ° C to form a biaxially stretched film having a To obtain strength of 35 pm. The mechanical and optical properties of this oil are given in Table IX.

In comparison, the properties of a biaxially stretched film with a thickness of 25 / im are also in the Table IX listed as comparative example 4, this film being produced by biaxial cornering of the base film (the uncoated 3? olie) with a thickness of 500 / um, as used in this example was obtained under the same conditions.

109839/1615

Table IX Example 34 .Comparative
example 4 properties 115
100
103 36
45 Shine (#) 45 °
60 °
₇₅ ο 1010 660 tensile strenght longitudinal 1980 410 (kg / cm) transversal 146 79 Tensile elongation (%) longitudinal 49 88 transversal

As can be seen from Table IX, the film of this example is in terms of surface gloss and Tensile strength noticeably better than the film of comparative example 4. If, in addition, the film of comparative example 4 is peeled off with an adhesive tape (Scotch tape ITo. 59) was, the coating of the film surface was peeled off, while none of the film of Example 4 Peeling occurred.

-Patent claims-

- 28 -

109839/1615

Claims (6)

Claims 1. Paper-like polymeric egg produced from a mixed composition which contains at least 5% of a polypropylene or ethylene / propylene-Oopolymeri'-sates with an ethyl content of 0 "to 15 Hol. α of a polyethylene or ethylene / propylene copolymer with a propylene content of 0 "to 30 Hol.% and 5-50% by weight of finely divided, solid, inorganic substance with a particle diameter of 0.1" to 15 W & contains, the Foil small, inner empty spaces "resp. Has pores, a rough surface with fine irregularities in a finely grooved state and is oriented in at least one direction, and wherein the void or pore content of the film is 4-0 - 300 ccm / 100 g and the permeability to light rays is higher than? Is 0 %. 2. Paper-like, polymeric film according to claim 1, characterized marked that the mixed composition xtfeiterhin 5-60 wt.% Of a styrenic resin contains. 3. Paper-like, polymeric film according to claim 1 or 2, marked by ich.net that at least a surface of the film with a biaxially oriented, transparent film layer is covered. 4. Paper-like, polymeric film according to claim 1 or 2, thereby g e 1; e η η ze i c h η e t that the inorganic Substance calcium carbonate, calcium oxide, titanium dioxide, Is silicon dioxide, aluminum oxide or aluminum sulfate. - 29 1 0983971615 3ο 5. Paper-like, polymeric egg according to claim 2, characterized g e Ic e η η s e i c Ii η e t that the styrene— like Hara a polystyrene, acrylonitrile-butadiene-styroloorpolymeris & t, Acrylonitrile-styrene copolymer or butadiene-styrene copolymer. 6. Paper-like, polymeric PiIm according to claim 1 oäer 2, marked by the fact that the Average diameter of the small empty spaces or Pores is 4 to 2 ^ 0 µm and the diameter of the irregularities aui the surface is 0.5 to 10 / ura. A method for producing a paper-like, polymeric film according to any one of the preceding claims, characterized in that the mixed composition is melted, the melt is extruded into an foil and the olie is stretched in at least one direction. 109839/1615