CZ325998A3 - Polyolefin film, composition and resin for its preparation as well as corresponding processes for making such film - Google Patents

Abstract

Polyolefin-based compositions for the production of vigorous follors include low abrasive anti-sticking agent formed by the composition the first component of the selected grease and the second component selected from the feldspar nepheline or nepheline syenites.

Description

The present invention relates to polyolefin-based resins, the starting materials used for their production, and films made therefrom. In particular, the invention relates to the use of talc, feldspar, nepheline and / or nepheline syenite.

BACKGROUND OF THE INVENTION

The invention relates to polyolefin-based resins which are intended for the production of clear films which are sufficiently resistant to sticking and wherein the sticking agent exhibits low abrasiveness. These films can be used in a wide variety of packaging and roofing applications.

Polyolefin films are used as packaging around the world, increasingly replacing traditional materials such as paper. The high transparency of polyolefin films allows inspection and identification of packaging contents. However, during the production of a plastic film, two or more layers of film are sometimes joined together or “stuck together”, making it difficult to separate the film, open the package or find the end of the roll.

Commercially, it is desired to reduce this sticking by adding inorganic mineral fillers to the polyefin film. It has been found that films made of resin containing anti-sticking agents have a coarser surface that worsens

- 2 close contact between the film layers and reduces sticking, therefore the term "sticking agents" is used for these fillers.

Not all inorganic fillers are effective as anti-sticking agents and some effective anti-sticking agents have other problems (such as high cost, abrasiveness, optical quality impact, health risks) that limit their commercial use. The aim is to add as little anti-sticking agent as possible to reduce sticking to the desired level while minimizing the adverse effect on the optical properties of the film and other requirements arising from the manufacturing equipment.

Kieselguhr is used as a reasonably effective anti-sticking agent but has the following unsuitable properties: light film opacity, poor film clarity, very high abrasiveness, and kieselguhr is relatively expensive. For certain polyolefin resins, talc is often also used as a relatively effective anti-sticking agent. Its advantage over diatomaceous earth is lower price, excellent film clarity and very low abrasiveness. However, the haze of the film is usually light and is not suitable for use in packaging with high film clarity requirements. Other anti-sticking agents were considered to be nepheline syenite or feldspar because the films containing them had a high clarity (since the optical refractive index was closer to polyethylene), but these substances are relatively poor as anti-sticking agents and have a very high abrasivity.

The abrasiveness of inorganic anti-sticking agents has to be addressed for several reasons. High ♦ ♦ · · · * * * * * * * *

- 3 abrasive anti-sticking agents can contribute to rapid wear of production equipment. When the wear reaches values where the dimensions of the equipment change in the critical area, both the dispersion of the additives in the resin and the rate of exit of the product can be negatively affected. In these cases, the quality of the product may suffer and the cost of the manufacturing process may increase, especially when the equipment has to be shut down and damaged parts replaced with new ones. In addition, abrasion of the device can cause metal contamination of the product, which has an adverse effect on the stability of the product or its color, or both. For these reasons, anti-sticking agents with low abrasiveness are preferred.

Many authors have attempted to solve the haze of polyolefin films and their anti-stick properties, but none of them have also paid attention to the clarity of the film and the abrasiveness of the anti-sticking agent and the overall cost (which are necessary conditions for a successful commercial product). In the current situation, it has to be stated that financially attractive anti-sticking agents for high-purity polyolefin films have not yet been produced.

SUMMARY OF THE INVENTION

The present invention relates to a composition wherein the first component is selected from talc and the second component is selected from feldspar, nephelins and nepheline syenites, wherein the ratio of the first component to the second provides abrasive properties significantly lower, can be expected according to the prior art. The invention further relates to an anti-sticking composition comprising a mixture of a first component selected from talc and a second component selected from among the talc;

Feldspar, nepheline and nepheline syenites, the ratio of the first component to the second providing anti-sticking efficacy significantly higher than would be the case with the individual components. This composition does not significantly affect the loss of optical properties when used in a polyolefin film.

The present invention also relates to a mixture of a first component selected between talc and a second component selected between feldspar, nepheline and nepheline syenites, wherein the ratio of the first component to the second component provides abrasive properties significantly lower than those predicted by the state of the art. techniques, and further, wherein the ratio of the first component to the second provides a sticking resistance significantly higher than would be expected with the individual components used alone.

The present invention also relates to polyolefin-based resins and compositions thereof, wherein the ratio of the first component to the second component provides anti-sticking performance considerably higher than would be expected for the components used alone, and the abrasive properties of the first and second component blends are at about 80% of the abrasiveness expected in the prior art.

The present invention further relates to polyolefin films comprising polyolefin-based resins, and these films can be made from the above ingredients having abrasive properties significantly lower than would be expected by the prior art, and the film has anti-sticking properties significantly higher than if it were made of individual components separately.

• ·

- 5 (, · · · ·

It is a benefit of the present invention that polyolefin-based blends and resins can be used to produce films having satisfactory anti-sticking and optical properties (haze and clarity). The starting mixture also has low abrasiveness. The combination produces a synergistic effect, wherein the degree of anti-sticking performance is unexpectedly higher than when used alone, while maintaining optical properties and low abrasiveness.

Japanese Kokai No. 60 (1985) - 49,047, Matsumoto et al., Method for the Production of Antifog Polyolefin Film, a method of using polyolefin-based compositions containing polyolefin resins, two types of powdered inorganic filler and an unsaturated fatty acid amide mixed with polyester unsaturated fatty acid has been described. .

U.S. Pat. Patent No. No. 5,346,944 to Hayashida et al., Polyolefin Resin Composition discloses polyolefin resin compositions comprising an anti-sticking agent and optionally an antistatic agent, an anti-turbidity agent, and an antioxidant.

Examples

One embodiment of the invention is a mixture of a first component selected between talc and a second component selected between feldspar, nepheline and nepheline syenites, wherein the ratio of the first component to the second component provides abrasive properties significantly lower than those predicted by the state of the art. techniques.

Preferably, the abrasion value is about 80% or less than expected in the prior art, more preferably it is

- about 50% or less of the predicted value of the prior art.

This mixture is used as a starting material in the manufacture of polyolefin-based resins and in films and other product types, such as sheets, molds and cast products, made from these polyolefin-based resins. Polyolefins suitable for practicing the present invention are any polyolefins that are clear, crystalline and capable of forming a self-supporting film. Examples which are not intended to be limiting include crystalline α-olefin homopolymers having a carbon number ranging from 2 to 12 or a mixture of two or more crystalline copolymers or copolymers of ethylene vinyl acetate with other resins. The polyolefin resin may also be high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymers, poly-1-butene, ethylene vinyl acetate copolymers, etc., and low and medium density polyethylenes. Other examples are irregular or block copolymers of polyethylene, polypropylene, poly-r-methylpent-1-ene, ethylene propylene, and copolymers. ethylene-propylene-hexene. Among these, ethylene-propylene copolymers and copolymers containing 1 or 2 substances selected from 1-butene, hexane-1,4-methylpentene-1, and 1-octene (so-called LLDPE) are particularly suitable. The processes for producing the polyolefin resins of the present invention are not particularly limited. For example, they can be made by ionic or radical polymerization. Examples of ionic polymerization polyolefin resins include homopolymers such as polyethylene, polypropylene, polybutene-1, and poly-4-methylpentene and ethylene copolymers obtained by copolymerizing ethylene and α-olefins, wherein the α-olefins have from 3 to 18 carbons such as propylene, butene-1,4-methylpent-1-ene, 1-hexene, 1-octene,

1-decene, and 1-octadecene. These α-olefins can be used alone or in one or two species. Other examples include propylene copolymers such as propylene and 1-butene copolymers. Examples of polyolefin resins obtained by radical polymerization include separate ethylene or copolymers of ethylene obtained by copolymerizing ethylene and radically polymerizable monomers. Examples of radically polymerizable monomers include unsaturated carboxylic acids such as acrylic acid, methyl acrylic acid and malonic esters and their acid anhydrides, and vinyl esters such as vinyl acetate. Specific examples of unsaturated carboxylic acid esters include methyl acrylate, methyl methacrylate and glycidyl methacrylate. These radically polymerizable monomers can be used alone or in one or two kinds.

The talc according to the invention is selected from those suitable for the production of polyolefin materials. A typical talc has a monoclinic crystal system, a specific gravity of 2.6 to 2.8, and its empirical formula is Mg ₃ Si ₄ O 10 (OH) 2.

The average particle size of the talc is preferably from 0.1 to 10 microns.

The second component is selected from feldspars, nepheline and nepheline syenites, or mixtures thereof. These materials are known in the art and are defined in the Minerals book. and Rocks, The New Encyclopedic Britannica, Vol. 24, s. 151157, 175-179, Encyclopedia-Britannica, Inc. (Chicago,

1986), where they are also described in their entirety.

• * • · · · · · · · ·

- 8 · · · 8 8 8 8

The average particle size of the second component is from 0.1 to 10 microns.

The mixture is prepared by conventional mixing which does not affect the reduction or agglomeration of the component. This mixing may or may not be part of the milling of the component, if any.

Abrasive properties are determined using an Einlehner AT 1000 Abrazion Tester. The recommended methodology, such as the use of equipment and procedures, is generally known. A manual called Einlehner Abrazion Tester AT 1000 is recommended for implementation.

Another embodiment of the invention is an anti-sticking composition comprising a mixture of a first component selected from talc and a second component selected from feldspar, nepheline and nepheline syenites, wherein the ratio of the first component to the second provides anti-sticking efficacy significantly higher than that achieved with the components. independently.

In a preferred embodiment, the ratio of both components is from 1/3 to about 3/1; that is, the composition has from about 25% to 75% talc relative to the other component. More preferably, the ratio is from about 45/55 to 75/15.

The anti-sticking performance of the composition achieves 85% or less of the effect that the ingredients would achieve alone. More preferably, the efficacy is 75% or less, even more preferably, the efficacy is about 50% or less of the value that the component would achieve in a single action.

• · • ·

- 10 «· ·

The anti-sticking agent may be used in the manufacture of polyolefin films, and in this use it is preferred that the mixture of the first and second components does not affect optical properties such as clarity and haze.

Another embodiment of the invention is a mixture of a first component selected from talc and a second component selected from feldspar, nepheline and nepheline syenites, wherein the ratio of the first to the second component provides abrasive properties significantly lower than would be expected according to the prior art; it ensures anti-sticking performance significantly higher than when using separate components.

The ratio of the first and second components is preferably from 1/3 to 3/1 and the abrasive properties of the first and second component mixtures are about 50% or less than would be expected in the art, and the anti-sticking agent provides a degree of sticking of 50% and less.

The blend of the first and second components may be made as a starting blend that is added to the polyolefin-based resin or prepared in situ in a polyolefin resin or as part of a polyolefin film production. The order of adding individual components is not a critical issue. When the substance is prepared in situ, the ingredients may be added separately in a specific order or simultaneously, or as separate batches that are subsequently mixed.

Another embodiment of the invention is a polyolefin resin comprising a mixture of a first component selected from talc and a second component selected from feldspar, nepheline and nepheline syenites.

Wherein the ratio of the first to the second component provides abrasive properties significantly lower than would be expected according to the prior art.

Another embodiment of the present invention is a polyolefin film comprising a polyolefin-based resin having a ratio of the first component to the second such that the abrasive properties are significantly lower than would be expected in the prior art, and further has anti-sticking performance significantly higher than if each component were used alone.

In polyolefin-based resins, mixtures of the first and second components are preferably wherein the ratio of the first and second components is from about 1/3 to 3/1 and the abrasive properties of the first and second components in the mixture are at a level of about 80% and below and the combination of the first and second components provides an anti-sticking efficiency of 50% or less.

Another embodiment of the invention is a polyolefin film comprising a first component selected from talc and a second component selected from feldspar, nepheline and nepheline syenites, wherein the ratio of the first to the second component provides abrasive properties significantly lower than expected in the art.

The polyolefin film preferably comprises a first component selected from talc and a second component selected from feldspar, nepheline and nepheline syenites, wherein the ratio of the first component to the second provides abrasive properties significantly lower than would be expected in the art and wherein the ratio of the first component to the second provides anti-sticking performance significantly higher than when used separately.

• ·

The invention is also described in the following examples, which are not intended to limit the scope of the invention.

Example 1

Laboratory measurements and anti-sticking measurements were performed using an Einlehner Abrazion Tester. The abrasiveness of the minerals and their mixtures was measured compared to the abrasiveness of diatomaceous earth as a control. Talc A (PolyTalc AG609), Talc B (Polybloc), nepheline syenite (Minex 7), and diatomaceous earth (Super Floss) were tested. Samples and mixtures are described below:

Test 1 = 50/50 * mixture of talc A and nepheline syenite

Test 2 = 50/50 mixture of talc B and nepheline syenite

Test 3 = 75/25 mixture of talc A and nepheline syenite

Test 4 = 25/75 mixture of talc A and nepheline syenite

Test 5 = 100% Talc

Test 6 = 100% nepheline syenite

Test 7 = 100% diatomaceous earth * 50/50 means 50% by weight to 50% by weight.

All samples were tested on the Einlehner Model AT-1000 Tester as 10% dry mineral solid sludge. A bronze wire target was ground. The test lasted 100 minutes and / or 174,000 abrasion cycles. The result was a milligram (mg) weight loss of the abraded target. The results are shown in Table 1.

- 12 Table 1

Test # Anti-Gluing Minerals Abrasion (mg) (Einlehner)

50/50 mixture of talc A and nepheline syenite 24

50/50 mixture of talc B and nepheline syenite 26

75/25 mixture of talc A and nepheline syenite 14

25/75 mixture of talc B and nepheline syenite 49

100% Talc A 1.3

100% nepheline syenite 131

100% diatomaceous earth 144

Example 2

In this experiment, talc and nepheline syenite, both substantially and in combination with kieselguhr as a control, were incorporated into LDPE (low density polyethylene) resin using a Leistritz twin screw extruder with a 50% total charge to produce starting samples with anti-sticking performance. The ratio of talc to nepheline syenite ranged from 0/100 to 100/0. The starting samples were then mixed with LDPE and the erucamide starting sample as a glidant and extruded to a one millimeter thick film using a screw and one blown slit so that the final film contained 2000 parts per million of total mineral anti-sticking agent and 750 ppm erucamide glidant. The product was then tested for sticking and optical properties (haze and clarity) using the following procedures:

- 13 Tests:

(1) Degree of gluing

ASTM D3354-74 parallel plate method was used to measure the degree of bonding. Samples of 8 x 8 dimensions were cut out from the unfolded tube. The two layers of films were separated and slowly passed through a grounded rod to remove static charge, and then recombined so that the inner surfaces initially separated by the bubble were in contact with each other. All films were subjected to a pressure of 1.0 psi (6.9 kPa) for 24 hours in an air recirculating oven at 40 ° C. The force required to separate the two layers was then determined and expressed in grams.

(2) Haze

This test was performed according to the ASTM-D 1003 methodology. Haze is the percentage of transmitted light that dissipates when passing through a film sample. The lower the haze value, the better the optical ability of the film to pass through the light.

(3) Clarity

For this test, a clarity meter with the company name Zebedee CL-100 was used, operating according to the manufacturer's specifications. Optical clarity is defined as the distance of detail that an object can see through a film. The higher the clarity of the film, the better the resolution of the film object.

• ·

- 14 • · · · · · · · · · · · · ·

Special anti-sticking agents were used in the samples: _T

Talc A (PolyTalc AG609), Talc B (Polybloc), nepheline syenite (Minex 7), and diatomaceous earth (Super Floss). The results of the anti-stick haze and clarity tests for the samples of Example 2 are shown in Table 2.

Table 2

2000 ppm anti-sticking agent and 750 ppm glidant in LDPE film

Sample number Antislepovací means (2000 ppm) Degree gluing Haze Clarity 1 50/50 talc mixture and nepheline syenite 33.9 5.5 51 2 50/50 mixture of talc B and nepheline syenite 34.1 5.6 47 3 75/25 talc mixture and nepheline syenite 35.5 5.5 55 4 25/75 talc B mixture and nepheline syenite 3I.5 5.4 51 5 100% talc 42.7 5.8 ⁵⁷ 6 100% nepheline syenite 43.5 4.9 50 7 100% diatomaceous earth 35.6 5.6 33

Example 15 of Example 2 mixed with

Example 3

In another experiment, the antifoam described in LDPE resin was pressed into a one millimeter thick film using a screw with a single blown extrusion slot such that the final film contained 5500 ppm total mineral antifoam. The films were then tested for sticking and optical properties (haze and clarity) using the same methods as described in Example 2. The results of the samples of Example 3 are shown in Table 3.

Table 3

5500 ppm anti-sticking agent and no glidant in LDPE film.

Sample Antislepovací Degree Haze Clarity number means 5500 ppm gluing 1 50/50 talc mixture AND and nephelin.syenite 32 7.3 38 2 100% talc 56 8.4 47 3 1 00% Nefel. syenite 58 6.5 28 4 100% diatomaceous earth 39 8.8 10 5 100% talc C 39 8.2 29

Talc C is talc ABT 2500 • ·

Claims (10)

PATENT CLAIMS A mixture of a first component selected from talc and a second component selected from feldspar, nepheline and nepheline syenites, characterized in that the ratio of the first to the second component provides abrasive properties significantly lower than would be expected in the art. A composition according to claim 1, wherein the ratio of said first and second components ranges from 3: 1 to 1: 3. The composition of claim 2, wherein said ratio is from 45:55 to 3: 1. 4. The composition of claim 1 wherein the abrasivity is about 50% lower than would be expected in the art. An anti-sticking composition comprising a composition as described in any one of the preceding claims selected from talc and a second component selected from feldspar, characterized in that the ratio of the first to the second component provides anti-sticking performance significantly higher than each component could provide separately. The composition of claim 5, wherein the anti-sticking performance provides a degree of sticking of about 75% and less than each component alone. - 17 · · · · · · · · · · · · · · · · Composition according to claim 5, characterized in that the mixture of the first component and the second component does not affect the significant loss of optical properties when used in a polyolefin film. A polyolefin resin composition comprising a mixture of a first component selected from talc and a second component selected from feldspar, nepheline and nepheline syenites as set forth in any of the preceding claims. The polyolefin resin composition of claim 8, wherein the ratio of the first component to the second component is from about 1/3 to 3/1 and the abrasive properties of the first and second components in the mixture are about 80% and less than would be expected according to the prior art and the first and second components in combination reduce the degree of sticking to 50% or less. A polyolefin film comprising the polyolefin resin composition of claims 8 and 9.