KR100351036B1 - Modified Polyolefin Compositions and Laminated Structures Using the Same - Google Patents

Abstract

(A) High pressure low density polyethylene having a melt flow rate of 0.1-10 g / 10 minutes and a density of 0.915-0.935 g / cm 3, and (B) Substantially having a melt flow rate of 0.1-30 g / 10 minutes and a density of 0.910-0965 g / cm 3. Ethylene homopolymers and / or ethylene / alpha olefin copolymers prepared using linear and transition metal catalysts, and (C) amorphous or low crystalline ethylene / with a melt flow rate of 0.1-10 g / 10 min and a density of 0.900 g / cm 3 or less. Alpha olefin copolymers, wherein the amounts of components (A), (B) and (C) are 50-70%, 20-45% and 5-30% by weight based on their total weight, respectively; A modified polyolefin composition in which at least a part of (A), (B) and (C) is modified as an unsaturated carbonic acid or derivative thereof, a composition layer made of this modified polyolefin composition, and a resin layer present on at least one side of the composition layer Laminate structure and an outer layer constituted by coextrusion and cooling as the modified polyolefin composition It has no corrugated tube laminate structure.

Description

Pathological polyolefin composition and laminated structure using the same

The present invention relates to a modified polyolefin composition and a laminated structure using the same. In particular, a modified polyolefin composition capable of preventing the generation of concave convex long wave shapes (wavy wave) in the circumferential direction of the tube when the tubular laminated structure is formed by co-extrusion and cooling, and a red worm structure which is prevented from forming a wave by using the same. It is about.

Laminates are known in which the intermediate layer is made of a polyamide or ethylene / vinyl alcohol copolymer and the outer layer is made of a composition of high pressure low density polyethylene and an amorphous or low crystalline ethylene / alpha olefin copolymer. However, this laminate has a disadvantage of poor appearance. This is because, after the co-extrusion of the composition and the resins into a tubular laminate, a wave form occurs in the outer layer in the water cooling step. Another disadvantage is that the composition in the molten state in the mandrel is poorly slid and the productivity is lowered.

It is an object of the present invention to provide a modified polyolefin composition.

It is a further object of the present invention to provide a modified polyolefin composition suitable for the outer layer of the laminate, in particular the outer layer of the laminate, of the laminate of polyamide or ethylene / vinyl alcohol copolymer.

It is another object of the present invention to provide a modified polyolefin composition which exhibits excellent adhesion to polyamide or ethylene / vinyl alcohol copolymer and which does not form wavy when used as the outer layer of the laminate.

It is still another object of the present invention to provide a modified polyolefin composition which exhibits excellent sliding property in a molten state in a mandrel during manufacture of a laminate, that is, has excellent productivity for producing a laminate.

Another object of the present invention to provide a laminate structure using the modified polyolefin composition.

Other objects and advantages of the present invention are apparent from the following description.

According to the present invention, the object and advantages of the present invention are (A) high pressure low density polyethylene having a melt flow rate of 0.1-10 g / 10 minutes and a density of 0.915-0.935 g / cm 3, and (B) a melt flow rate of 0.1-30 g / 10. Min, a substantially linear, ethylene homopolymer and / or ethylene / alpha olefin copolymer prepared using a transition metal catalyst having a density of 0.910-0.965 g / cm 3, and (C) a melt flow rate of 0.1-10 g / 10 min, An amorphous or low crystalline ethylene / alpha olefin copolymer having a density of not more than 0.900 g / cm 3, wherein the amounts of components (A), (B) and (C) are 50-70% by weight and 20-45 based on their total weight, respectively. Wt% and 5-30 wt%, at least some of these components, (A), (B) and (C), are achieved by a polyolefin composition modified as unsaturated carbonic acid or derivatives thereof.

The modified polyolefin composition of the present invention comprises components (A), (B) and (C), as described above,

At least some of these components are graft modified as unsaturated carboxylic acids or derivatives thereof.

Component (A) is a high pressure method low density polyethylene having a melt rate of 0.1-10 g / 10 min and a density of 0.915-0.935 g / cm 3 measured at 190 ° C. under a load of 2.16 Kg according to ASTM D1238. Preferred melt flow rates are 0.2-5 g / 10 min and preferred densities are 0.910-0.935 g / cm 3.

Component (B) is prepared using a transition metal catalyst such as a Ziegler catalyst having a melt flow rate of 0.1-300 g / 10 min and a density of 0.910-0.965 g / cm 3 measured at 190 ° C. under a load of 2.16 Kg according to ASTM D1238. Ethylene homopolymer and ethylene / alpha olefin copolymer. Preferred ethylene / alpha olefin copolymers as component (B) are linear random copolymers of ethylene and alpha olefins having 3-20 carbon atoms. Preferred alpha olefins are alpha olefins having 4-10 carbon atoms. Examples of alpha olefins are preferably propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, particularly preferably 1-butene and 4-methyl-1 -Pentene is good.

Examples of ethylene / alpha olefin copolymers prepared with transition metal catalysts include ethylene / propylene random copolymers, ethylene / 1-butene random copolymers and ethylene / 4-methyl-pentene random copolymers.

As component (B) the ethylene polymer preferably comprises 100-80% by weight, more preferably 100-90% by weight of repeating units derived from ethylene.

Component (B) may be a combination of ethylene homopolymer and ethylene / alpha olefin copolymer. For example, it may be a combination of 0.5-40% by weight of ethylene homopolymer and 60-99.5% by weight of ethylene / alpha olefin copolymer, based on 100% by weight of the total dipolymer.

As the component (B), the melt flow rate of the ethylene polymer is preferably 0.2-5 g / 10 minutes, preferably 0.920-0.950 g / cm3, and more preferably 0.930-0.950 g / cm3.

Component (C) is an amorphous or low crystalline ethylene / alphaolefin copolymer having a melt flow rate of 0.1-10 g / 10 min and a density of 0.900 g / cm 3 or less, measured at 190 ° C. under a load of 2.16 Kg according to ASTM D1238.

The ethylene / alpha olefin copolymer (C) is preferably a random copolymer of ethylene and an alpha olefin having 3-20 carbon atoms. Examples of alpha olefins include those interposed with respect to component (B). Among them, alpha olefins having 3-4 carbon atoms are preferred. Preferred examples of the ethylene / alpha olefin copolymer (C) include ethylene / propylene random copolymers and ethylene / 1-butene random copolymers.

The ethylene / alpha olefin copolymer (C) preferably comprises repeating units derived from 50-90 mol%, more preferably 60-80 mol% of ethylene.

It is preferable that the melt flow rate of the ethylene / alpha olefin co-polymer (C) is 0.1-10 g 10 minutes and the density is 0.85-0.89 g / cm 3.

Ethylene / alpha olefin copolymers (C) having such physical properties are generally amorphous or low crystalline copolymers having a degree of crystallinity of 40% or less, as measured by the X-ray method.

The modified polyolefin composition of the present invention is 50-70% by weight of component (A), 20-45% by weight of component (B), based on the total weight of components (A), (B) and (C) C) 5-30% by weight. Preferably it contains 52-60 weight% of component (A), 25-40 weight% of component (B), and 10-20 weight% of component (C).

In the composition of the present invention, at least some of the components (A), (B) and (C) are graft-modified as unsaturated carboxylic acids or derivatives thereof. Components. Some or all of one of (A), (B) and (C) may be graft-modified, or some or all of their mixtures may be graft-modified.

In other words, the graft modification may be performed on one component or a mixture of plural components. Preferably, the component (B) is graft-modified.

Examples of unsaturated carboxylic acids and derivatives thereof include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, trotonic acid, isocrotonic acid and nadic acid (endocys-bicyclo [2,1,1] hept). Unsaturated carbon acids such as -5-ene-2,3-dicarboxylic acid) and derivatives thereof, such as halides, amides, imides, anhydrides and esters.

Specific examples of such derivatives include incidental maleyl, monomethyl maleate, dimethyl maleate, glycidyl maleate and the like.

Among them, unsaturated dicarboxylic acid or anhydride thereof is preferable, and maleic acid, nadic acid and anhydride thereof are particularly preferable. They are used alone or in combination, and the graft ratio is preferably 0.001-5% by weight, more preferably 0.01-3% by weight.

Various methods known in the art can be used to perform the graft reaction.

For example, the polymer is melted and a graft monomer (unsaturated carboxylic acid or a derivative thereof) is added thereto to perform a graphitic reaction, and the polymer is dissolved in a solvent to form a solution, and then a graft monomer is added thereto. And how to do the reaction. In any case, in order to efficiently perform the graft reaction, it is preferable to perform the graft reaction in the presence of a radical initiator. The graft reaction is generally carried out at 60-350 ° C. The radical initiator is generally used in 0.001-1 parts by weight per 100 parts by weight of the polymer.

As radical initiator, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl pioxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxide benzoate) hexine-3, 1,4- Bis (tert-butylperoxyisopropyl) benzene, lauroyl coated side, tert-butyl peracetate, 2,5-dimethyl-2,5-bi (butylperoxy) hexane-3, 2,5-dimethyl- 2,5-di (tert-butylperoxy) hexane, tert-butylperbenzoate, tert-butylperphenyl acetate, tert-butylperisobutylate, tert-butylper-sec-octoate, tert-butylpupy Organic peroxides and organic polyesters such as valate, cumyl perpivalate, and tert-butyl perdiethyl acetate, and other azo compounds such as azobiscibutyronitrile and dimethyl azoisobutylate can be used. Among them, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane-3, 2,5-diethyl-2,5-di ( dialkyl peroxides such as tert-butylperoxy) hexane and 1,4, -bis (tert-butylperoxyisopropyl) benzene are preferred.

The graft reaction can be carried out on a mixture of components (A), (B) and (C) to obtain the modified polyolefin composition of the present invention. Alternatively, one or more of the components (A), (B) and (C) may be graft-modified and then the resulting modified material may be melt kneaded with the unmodified components to obtain the composition of the present invention. It is preferable to melt knead the component (B) together with component (A) and component (C) after graft modification of component (B) to obtain the composition. The unmodified component (s) and the modified components by the extruder. Methods of melt kneading (A), (A) and (C) are preferably used in industry.

The graft ratio here is defined as the weight percent of unsaturated carboxylic acid or derivative thereof grafted based on the total weight of components (A), (B) and (C) prior to grafting.

The modified polyolefin composition of the present invention is suitably used as an outer layer of the laminate structure, in particular as a laminate structure using ethylene / vinyl alcohol copolymer or polyamide as an intermediate layer.

Therefore, the present invention relates to a composition layer composed of the modified polyolefin composition according to the present invention (hereinafter, the composition layer composed of the modified polyolefin composition according to the present invention is abbreviated as "composition layer") and the number present on at least one side of the composition layer. Provide a layered laminate structure.

As the resin of the resin layer constituting the laminate structure, various thermoplastic resins such as polyolefin, polyester, polyamide and ethylene / vinyl alcohol copolymer can be used. Among them, polyamide and ethylene / vinyl alcohol copolymer can be preferably used.

As polyamides for example nylon 6, nylon 66, and MXD nylon (methaxylylene diamine copolymer polyamide) are used.

The ethylene / vinyl alcohol copolymer contains 20-50 mol%, preferably 25-48 mol% of units derived from ethylene.

They can be prepared by saponifying the corresponding ethylene / vinyl acetate copolymers by conventional methods.

In the laminate structure of the present invention, it is preferable that the resin layer present on at least one side of the composition layer is a resin selected from polyamide and ethylene / vinyl alcohol copolymer.

Moreover, the laminated structure of this invention has a composition layer, a resin layer, and a composition layer in order.

By forming the outer layer of the locust structure as a composition layer, it is possible to obtain a wave-free product in the cooling step when producing the laminate structure.

The laminate structure according to the present invention can be produced by melting the modified polyolefin composition and the resin and then laminating them in a molten state.

The double-layered structure can be molded into a desired shape by extrusion molding, casting molding, expansion molding, or the like. The laminate structure of the present invention is preferably formed into a tubular shape by coextrusion. The laminate structure formed in a tubular shape can be processed into a tubular container such as a food packaging film or cosmetics, for example.

Example

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these embodiments.

Example 1

The layers of the following structure were coextruded under the following conditions to form a three-layer tube.

Outer and inner layers

As component (A), 52% by weight of high pressure low density polyethylene (HPLDPE-1) having a melt flow rate of 4 g / 10 minutes and a density of 0.918 g / cm 3, and a melt flow rate of component (B-1) of 1 g / 10 minutes and a density of 0.953 g / cm 3, 25% by weight of an ethylene / propylene copolymer (LLDPE-1) prepared using a transition metal catalyst, a melt flow rate of 4 g / 10 min density 0.965 g / cm 3 as component (B-2), 8% by weight of graft modified polyethylene (MAH-PE) grafted with 2% by weight maleic anhydride as a substantially linear ethylene monopolymer prepared using a transition metal catalyst and a melt flow rate of 3.5 g / 10 minutes as component (C). 15 weight% of the ethylene / 1-butene copolymer (EBR-1) having a density of 0.885 g / cm 3 and a crystallinity of 5% or less was melt kneaded at 200 ° C. by a sunrise extruder to obtain a modified polyolefin composition. This composition had a melt flow rate of 1.7 g / 10 minutes and a density of 0.921 g / cm 3. The modified polyolefin composition thus obtained was coextruded with an extruder having a screw having a diameter of 40 mm and an effective length of 1000 mm.

Mezzanine

Eval EP-F (trademark melt flow rate; 1.3 g / 10 min) manufactured by Guraray as ethylene / vinyl alcohol copolymer (hereinafter referred to as EVOH) was transferred to an extruder having a screw having a diameter of 30 mm and an effective length of 750 mm. Coextruded at 225 ° C.

The temperature of the dice was 220 ° C., and each of the coextruded resin was taken at a rate of 5 m / min, cooled in a water bath 50 cm behind the die, and formed into a tube. The thickness of each layer was manufactured as outer layer / intermediate layer / inner layer = 150/50 / 250μm, and the adhesion strength, dynamic friction coefficient and presence of wave shape between the outer layer and the middle layer of the tube are shown in Table 1.

Adhesion strength was measured by 180 ° peeling method. The dynamic friction coefficient is measured after opening the tube, applying a 200g load on it, and pulling it at a speed of 50mm / min on a stainless steel plate.

The presence or absence of a wave shape was evaluated by visually observing the occurrence of rib-shaped concave-convex shape on the outer surface of the tube after water cooling. In Table 1, ○ means no wave and X means there is.

Example 2-4

The procedure of Example 1 was repeated except that the composition of the modified polyolefin composition constituting the outer and inner layers was changed to the composition shown in Table 1 to obtain the results shown in Table 1.

Comparative Example 1-2

Except for changing the composition of the modified polyolefin composition constituting the outer layer and the inner layer to the composition shown in Table 1, the procedure of Example 1 was repeated to obtain the results shown in Table 1.

The abbreviations in Table 1 are as follows:

HPLDPE-1: high pressure low density polyethylene (melt flow rate 4g / 10min, density 0.918g / cm3)

HPLDPE-2: high pressure low density polyethylene (melting flow rate 2.5g / 10min, density 0.932g / cm 3)

HPLDPE-3: high pressure low density polyethylene (melt flow rate 3g / 10min, density 0.927g / cm 3)

HPLDPE-4: high pressure low density polyethylene (melt flow rate 1g / 10min, density 0.918g / cm 3)

LLDPE-1: substantially linear ethylene / propylene copolymer (melting flow rate 1g / 10min, density 0.953g / cm 3)

LLDPE-2: substantially linear ethylene / butene-1 copolymer (melting flow rate 1g / 10min, density 0.935g / cm 3)

MAH-PE: Modified polyethylene in which substantially linear ethylene homopolymer is grafted with 2% by weight of maleic anhydride (melting flow rate 4g / 10min, density 0.965g / cm 3)

EBR-1: Ethylene / butene-1 copolymer (melting flow rate 3.5 g / 10 min, density 0.885 g / cm 3)

EPR-2: ethylene / propylene copolymer (melt flow rate 3g / 10min, density 0.870g / cm 3)

Example 5

Extruded by an extruder having a screw having a diameter of 30 mm and an effective length of 750 mm in the same manner as in Example 1 at 250 ° C. using Amiran ™ CM1021 XF manufactured by Toray Corporation as polyamide.

The temperature of the dice was 250 ° C., each of the coextruded resin was taken at a rate of 5 m / min, cooled in a water bath 50 cm behind the die, and formed into a tube. The thickness of each layer was made of outer layer / intermediate layer / inner layer = 150/50 / 250μm, and the adhesion strength, dynamic friction coefficient and wave shape between the outer layer and the middle layer of the tube are shown in Table 2.

Example 6 and Comparative Example 3-4

The procedure of Example 5 was repeated except that the modified polyolefin composition constituting the outer and inner layers was changed to the composition shown in Table 2 to obtain the results shown in Table 2.

The abbreviations in Table 2 are as follows:

HPLDPE-1: high pressure low density polyethylene (melt flow rate 4g / 10min, density 0.918g / cm3)

HLDPE-2: high pressure low density polyethylene (melting flow rate 2.5g / 10min, density 0.932g / cm 3)

HPLDPE-3: high pressure low density polyethylene (melt flow rate 3g / 10min, density 0.927g / cm 3)

LLDPE-1: substantially linear ethylene / propylene copolymer (melt flow rate 1g / 10min, density 0.935g / cm 3)

LLDPE-2: substantially linear ethylene / butene-1 copolymer (melting flow rate 1g / 10min, density 0.935g / cm 3)

MAH-PE: A substantially modified ethylene homopolymer is a modified polyethylene in which 2% by weight of maleic anhydride is grafted (melting flow rate 4g / 10min, density 0.965g / cm 3)

EBR-1: Ethylene / butene-1 copolymer (melting flow rate 3.5 g / 10 min, density 0.885 g / cm 3)

EPR-2: ethylene / propylene copolymer (melt flow rate 3g / 10min, density 0.870g / cm 3)

Claims (8)

(A) High pressure low density polyethylene having a melt flow rate of 0.1-10 g / 10 minutes and a density of 0.915-0.935 g / cm 3, and (B) Substantially having a melt flow rate of 0.1-30 g / 10 minutes and a density of 0.910-0.965 g / cm 3. Ethylene homopolymer and / or ethylene / alpha olefin copolymer prepared using a transition metal catalyst, and (C) amorphous or low crystalline ethylene having a melt flow rate of 0.1-10 g / 10 min and a density of 0.900 g / cm 3 or less. / Alpha olefin copolymers, wherein the amounts of components (A), (B) and (C) are 50-70%, 20-45% and 5-30% by weight based on their total weight, respectively Modified polyolefin composition, characterized in that at least a part of (A), (B) and (C) is graft-modified with unsaturated carbonic acid or derivatives thereof. The modified polyolefin composition according to claim 1, wherein the component (B) is a combination of an ethylene homopolymer and an ethylene / alpha olefin copolymer. 3. The modified polyolefin composition according to claim 2, wherein the ethylene homopolymer is graft modified. The modified polyolefin composition according to claim 1, wherein the graft ratio of the unsaturated carboxylic acid or derivative thereof is 0.001-5% by weight based on the total weight of components (A), (B) and (C). A laminate structure comprising a composition layer of the modified polyolefin composition of claim 1 and a resin layer present on at least one side of the composition layer. The laminate structure according to claim 5, wherein the resin layer present on at least one side of the composition layer is a layer of a resin selected from polyamide and ethylene / vinyl alcohol copolymer. The laminate structure according to claim 5, wherein the composition layer, the resin layer, and the composition layer are stacked in the order listed. The laminate structure of claim 5 having a tubular shape.