KR19990080603A - Films, sheets, molded articles and the like, which are molded from a mixture of polyolefin and polyvinyl alcohol, and the like are used. - Google Patents

Abstract

The present invention is a mixture of 1 to 80% by weight of polyethylene and 20 to 99% by weight of polyvinyl alcohol, based on 100% by weight of polyethylene 3 to 40% by weight and / or 0.1 to 5% by weight of low molecular weight compatibilizer And 0.01 to 0.5 wt% of an initiator, 3 to 50 wt% of a plasticizer, 1 to 10 wt% of a processing aid, and 0.01 to 5 wt% of an antioxidant based on 100 wt% of polyvinyl alcohol by melting and molding. The present invention relates to a gas and organic solvent barrier film, a sheet, a molded article, and a multilayer structure product using the same. These films, sheets, and molded products exhibit excellent physical properties of both polymers due to the unique morphology of polyethylene and polyvinyl alcohol, and can be thermally fused with other resins without the need for separate adhesives. It has advantages.

Description

Films, sheets, molded articles formed from mixed compositions of polyolefin and polyvinyl alcohol, and multi-layered products using them

The present invention relates to a film, a sheet, a molded article and a multilayer structure product using the same having excellent gas and organic solvent barrier properties. Specifically, a polyolefin and a polyvinyl alcohol are used as a compatibilizer, an initiator, a plasticizer, a processing aid and an antioxidant. The present invention relates to a film, a sheet, a molded article, and a multi-layered product made by melting a mixed composition made by addition.

The gas refers to a gaseous state of an organic solvent such as oxygen, nitrogen, and the like, and the organic solvent means hydrocarbons such as benzene, toluene, xylene, ketones, alcohols, esters, ethers, and the like. It is interpreted as above.

Conventionally, a mixture of polyolefin and polyvinyl alcohol has been mainly used in the field using the hydrophilicity of polyvinyl alcohol rather than a multilayer structure product having barrier properties. The contents of this are as follows through related patents and patent application publications.

In U.S. Patent No. 4,529,539 and Japanese Patent No. 60147473, a mixture of polyolefin and polyvinyl alcohol was used in an electrically conductive plastic product. In Japanese Patent Nos. 77024976 and 54020057, a mixture of polyolefin and polyvinyl alcohol in a battery was used as a desiccant. Japanese Patent No. 70001747 was used to improve the dyeability of polyolefin fibers, and Japanese Patent No. 79036095 was used as a reinforcing fiber for cement to increase the strength of cement.

In addition, although there are a number of patents showing examples of using polyvinyl alcohol as a film to enable melting, each case has a different configuration from the present invention, the contents are as follows.

U.S. Patent No. 3,365,413 discloses an invention for use in blown extrusion by lowering the melting point of the resin by retaining the acetate content at 25 to 40% by weight during the polymerization of polyvinyl alcohol to act as a plasticizer.

U.S. Patent No. 3,997,489 discloses a method of improving melt processing properties by adding low molecular weight oils or waxes, and U.S. Patent No. 4,206,101 uses 5-20 wt% polyethylene glycol to melt-extrude A water soluble film that melts quickly and completely is disclosed.

U.S. Patent No. 4,244,914 discloses a method of plasticizing polyvinyl alcohol with water and then removing water with an extruder vent while coextrusion in a liquid state, and U.S. Patent No. 4,611,019 adds polyvinylamide or polyester Disclosed is a melt extrusion process by plasticizing polyvinyl alcohol.

US Pat. No. 4,672,082 provides a method for enabling the production of polyvinyl alcohol in the absence of water, but has a problem of cooling at a sufficiently slow rate to improve barrier properties.

U.S. Patent No. 5,317,052 discloses the addition of a metal compound to polyvinyl alcohol to enable melting by raising the temperature of pyrolysis. European Patent No. 0 417 357 converts an extruder to provide sufficient energy for polyvinyl alcohol. The present invention provides a method for producing gel-free thermoplastic polyvinyl alcohol by melting polyvinyl alcohol at high speed.

EP 0 187 040 discloses a process for preparing a film by preparing olefin / vinyl alcohol segment copolymers in which polyvinyl alcohol is introduced into polyethylene using silane, but using a plasticizer, a processing aid and an antioxidant, By using a very limited type of compatibilizer without improving vinyl alcohol, there is a problem that the oxygen barrier property is greatly reduced despite using the same amount of polyvinyl alcohol compared to the present invention. Since this allows only the blending of polyolefin and polyvinyl alcohol through modification by silane without improving the melting characteristics of polyvinyl alcohol, it does not have a morphology of the polyolefin and polyvinyl alcohol mixture resin of the present invention. There is a limit to the blocking ability of the.

European Patent No. 0 152 180 discloses a method of grafting polyvinyl alcohol by introducing a functional group into polyolefin, but mainly deals with the characteristics of the compatibilizer and the graft reaction accordingly, and gel generation, which is a fundamental problem in melt processing of polyvinyl alcohol. The problem of yellowing and yellowing is not solved.

Although polyvinyl alcohol is the polymer having the best gas and organic solvent barrier properties among the existing polymers, the melting point and the thermal decomposition temperature are close to each other, and the gel is easily generated. Particularly, since polyvinyl alcohol is very sensitive to heat, it is easily pyrolyzed even at a relatively low temperature, so that the gel is increased, and yellowing phenomenon occurs severely, so it is very difficult to mold the product into a commercial product. Therefore, in the prior art, the polyvinyl alcohol was modified or added with a plasticizer to enable melting, but it did not completely solve the gel and yellowing phenomenon, which is a fundamental problem of polyvinyl alcohol. Although the molding method was used, the manufacturing cost of the film was greatly increased due to long drying.

In recent years, efforts have been made to utilize polyvinyl alcohol's excellent gas and organic solvent barrier properties by improving the reforming method and processing equipment through blending polyolefin and polyvinyl alcohol.

However, not all of these methods completely melt polyvinyl alcohol to enable molding processing freely, and the method using the excellent gas and organic solvent barrier properties of polyvinyl alcohol to the extent of having a commercial property is not much more.

Accordingly, an object of the present invention is to add a specific amount of a plasticizer, an initiator, a compatibilizer, a processing aid, and an antioxidant to a mixture of polyolefin and polyvinyl alcohol to enable melt molding by a conventional processing method and to form a unique morphology. It is to obtain films, sheets and shaped articles having high barrier properties to gases and organic solvents.

Another object of the present invention is to obtain a multilayer structure product having excellent gas and organic solvent barrier properties through the combination of the thus obtained films, sheets and shaped bodies with other resins.

1 is an electron micrograph at 34 times the cross section of a pellet;

FIG. 2 is an electron micrograph at 1500 times the cross section of the film.

The present invention,

(A) 1 to 80% by weight of polyolefin and 20 to 99% by weight of polyvinyl alcohol,

(B) 3 to 40% by weight of the polymeric compatibilizer, or 0.1 to 5% by weight of the low molecular compatibilizer and 0.01 to 0.5% by weight of the initiator that causes the reaction of the compatibilizer with the polyolefin, based on 100% by weight of the polyolefin, or the polymer A mixture of a system compatibilizer and a low molecular compatibilizer and an initiator,

(C) 3 to 50% by weight of plasticizer, based on 100% by weight of polyvinyl alcohol,

(D) 1 to 10% by weight of the processing aid, based on 100% by weight of polyvinyl alcohol, and

(E) relates to a film, sheet, molded article, and a multilayer structure product using the same by melting a mixed composition composed of 0.01 to 5% by weight of an antioxidant based on 100% by weight of polyvinyl alcohol.

Polyolefin has excellent processability and is cheaper than general-purpose resins and polyvinyl alcohol, which have different price, so it has superior advantages in price competition of final molded resin, while its barrier property to gas and organic solvents is inferior. In order to be used as a combination with a resin that can compensate for this is required. In the present invention, polyvinyl alcohol is selected as a material capable of ideally supplementing the disadvantages while maximizing the advantages of the polyolefin, thereby solving the mutual problem. Polyolefins used in the present invention include polyethylene (HDPE, LDPE, LLDPE, MDPE, VLDPE), polypropylene, polybutene, ethylene-propylene rubber (EP rubber), ethylene-propylene diene rubber (EPD rubber), poly-4- One or two or more polymers or copolymers selected from the group consisting of methyl-1-pentene (TPX), propylene, butene, hexene and / or octene and ethylene, and olefinic thermoplastic elastomers.

Polyvinyl alcohol is a polymer having excellent gas and organic solvent barrier properties among existing polymer resins, but the melting point and the pyrolysis temperature are close to each other, so that a conventional hot melt processing method cannot be applied. Polyvinyl alcohol may be used in various kinds, of which the degree of hydrolysis is 99.5 mol% or less, the degree of polymerization is preferably 300 to 3000, the degree of saponification is 85 to 90 mol% and the degree of polymerization 400 to It is more preferable that it is 2000.

The plasticizer lowers the melting point of the polyvinyl alcohol to enable thermal melting, lowers the crystallinity of the polyvinyl alcohol, and lowers rigidity and brittleness and solves the problem of gel formation. Plasticizers used in the present invention include glycerin, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, a mixture of glycerin and water, polyethylene glycol, polypropylene glycol, trimetholpropane, triethylene glycol, isopropanol There is one or more mixtures selected, and in particular, glycerin or a mixture of glycerin and water and trimetholpropane with a purity of at least 99% are preferred. As the content of the plasticizer increases, the processability of the polyvinyl alcohol is improved, but the barrier property is inferior. If the content is less than 5% by weight, the barrier property is very good, but the processability is remarkably inferior, more preferably 5 to 30% by weight.

The polyvinyl alcohol starts to be thermally decomposed gradually from 100 ° C., and the decomposition rate increases more than 150 ° C., and then rapidly decomposes beyond 200 ° C., which can be observed from a phenomenon in which the color gradually changes to yellow. Therefore, a processing aid and an antioxidant to prevent yellowing of polyvinyl alcohol are required, and processing aids used in the present invention include an acrylic oligomer, phosphate, calcium stearate, zinc stearate and magnesium stearate. One or two or more mixtures selected from the group consisting of stearic acid, paraffin wax, and polyethylene wax may be used, and the addition amount is more preferably 2 to 7% by weight based on 100% by weight of polyvinyl alcohol.

Antioxidants prevent yellowing and at the same time act as a stabilizer against heat during processing and / or prolonged use of polyvinyl alcohol. The antioxidant used in the present invention includes a phenolic antioxidant, a phosphate antioxidant, a calcium-zinc-tin organic mixture antioxidant, a dioctyltin malate-based antioxidant, and a dioctyltin-merhitide-based antioxidant. And one or more mixtures selected from the group, and the amount is more preferably 0.05 to 3% by weight based on 100% by weight of polyvinyl alcohol.

Since polyolefins are inherently incompatible with polyvinyl alcohol, when mixed with resins, polyolefins form a separate interface, thereby preventing the molded products from properly exhibiting barrier properties and mechanical properties. Therefore, a polymer compatibilizer having a non-polar segment compatible with polyolefin and a polar segment compatible with polyvinyl alcohol simultaneously in one molecular unit, or by reacting and attaching to some molecular chains of polyolefin through the reaction, A low molecular weight compatibilizer for modifying the above and an initiator for inducing such a reaction are attached. In some cases, a high molecular compatibilizer, a low molecular compatibilizer and an initiator may be used together.

Polymeric compatibilizers include ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-alkyl acrylate-acrylic acid copolymer, ethylene-alkyl meta One or more mixtures selected from the group consisting of an acrylate-methacrylic acid copolymer, an ethylene-butylacrylate copolymer (EBA), an ethylene-vinylacetate copolymer (EVA), or a modified product thereof may be used, and Of these, maleic anhydride modified products of the ethylene-ethyl acrylate copolymer are particularly preferable. The addition amount is more preferably 5 to 20% by weight based on 100% by weight of polyolefin.

As the low molecular system compatibilizer, monomers or unsaturated silane compounds having a carboxylic acid group in a molecular unit are used. For example, acrylic acid, methacrylic acid, maleic acid, fmaric acid, itaconic acid, crotonic acid, sorbic acid, or these Anhydrides of; Or vinyltrimethoxy silane, vinyltrimethoxymethoxyethoxy silane, vinyltriethoxy silane, gamma- (meth) acryloxypropyltrimethoxy silane, gamma- (meth) acryloxypropyltriethoxy silane, vinyl-tris One or more mixtures selected from the group consisting of (beta-methoxyethoxy) silane and vinyltriacetoxy silane are used. The addition amount of the low molecular weight compatibilizer is more preferably 0.5 to 3% by weight based on 100% by weight of the polyolefin.

As the initiator, one or more mixtures selected from the group consisting of acyl peroxide based, dialkyl or dialkyl peroxide based, peroxy ester based, hydroperoxide based, ketone peroxide based and azo compound based initiators are used, For example, benzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, cumylbutyl peroxide, 1,1-di-tert-butyl peroxy-3,5,5-trimethylcyclohexane, 2, 5-Methyl-2,5-2,5-di-tert-butyl peroxy isopropylbenzene, tert-butyl peroxy pivalate, tert-butyl di (perphthalate) dialkyl peroxy monocarbonate, pe One or two selected from the group consisting of oxydicarbonate, tertiary butyl hydroperoxide, p-methane hydroperoxide, cumene hydroxide, cyclohexano peroxide, methylethylketone peroxide, azobisisobutylonitrile Mixtures of the above may be used. The addition amount of the initiator is more preferably 0.05 to 0.3% by weight based on 100% by weight of the polyolefin.

These polyolefin / polyvinyl alcohol mixed composition resins form a unique morphology, which is one of the features of the present invention.

The polyolefin / polyvinyl alcohol mixed composition resin may be classified into a case in which the polyvinyl alcohol content is 30 to 50 wt% and the case of 50 to 70 wt% according to the change of the morphology. When the content of the polyvinyl alcohol is 30 to 50% by weight, the polyolefin forms a matrix phase, and when the content of the polyvinyl alcohol is 50 to 70% by weight, the polyvinyl alcohol forms a matrix phase.

When the polyolefin forms a matrix, that is, when the polyvinyl alcohol is 30 to 50% by weight, the polyvinyl alcohol is formed to be covered by the polyolefin, so the property of dissolving the polyvinyl alcohol in water disappears. This shape can be confirmed in FIGS. 1 and 2 in which the mixed composition of polyolefin / polyvinyl alcohol is formed into pellets and films, respectively, and its cross section is taken by electron micrographs. Referring to FIG. 1 showing the cross section of the pellet, it can be seen that the polyolefin (polyethylene) forms a circular matrix and the polyvinyl alcohol forms a continuous layer of circular arcs (“onions”) in the matrix. . Looking at the cross section of the film, it can be seen that the outer polyolefin has a shape surrounding the polyvinyl alcohol of the middle face up and down. In FIG. 2, white projections can be observed in the middle of the film, which is a polyvinyl alcohol resin separated during the cutting of the film, in which a polyvinyl alcohol in the matrix of the polyolefin has a continuous plate shape ("plate"). Form ") to make sure it exists.

In particular, the morphology shown in the pellet is a very unique structure that does not appear in general pellet production, and in order to obtain such a continuous morphology, it is a structure obtained by forcibly biaxially stretching after forming into pellets and molding into a film or the like. The continuous onion-shaped structure appeared in the pellet is a structure that can maximize the barrier properties when forming into a film, sheet, container, etc., in particular, even in a thin film can significantly improve the barrier effect. In particular, with regard to the manufacture of films, conventional methods cannot use conventional molding machines and can only mold products through special modifications to the machine, but when using the composition pellets of the present invention, a conventional screw-like machine Even in the molding process, the ability of forming a continuous plate-shaped morphology is excellent, so that the barrier property of the film is much better.

As such, the resin of the mixed composition of the present invention exhibits a unique morphology not found in the resin of the conventional polyvinyl alcohol composition, and the morphology thereof maximizes the water resistance of the polyolefin while maximizing the gas and organic solvent barrier properties of the polyvinyl alcohol. It is a structure that can be expressed at the same time. In addition, the polyolefin forming the outer surface of the molded article can be hot melt adhesion without other adhesives with other polyolefin molded article and can form a molded article that is very stable to moisture in the air, so the barrier property of polyvinyl alcohol is not affected by the moisture at all. Do not. Therefore, the pellet of the polyolefin / polyvinyl alcohol mixture composition is extruded in a twin extruder, and then immediately subjected to a long drying process such as polyamide or ethylene vinyl alcohol copolymer (EVOH), which is a conventional barrier material, without being required. It may be extruded alone or co-extruded with other polyolefins to form a film, sheet, container, or the like.

On the other hand, when the polyvinyl alcohol forms a matrix, that is, when the content of the polyvinyl alcohol is 50 to 70% by weight, the outer surface of the molding resin becomes a polyvinyl alcohol sensitive to moisture, so that it is used as a packaging multilayer structure product. The adhesive should be coextruded or laminated with other polyolefin resins that are water resistant using adhesives. The final molded product co-extruded or laminated with polyolefin has excellent barrier properties and can be manufactured by the same manufacturing method as conventional molding processes such as polyamide and EVOH, which are other barrier multilayer products. This barrier multilayer product is the same as other multilayer products in that it uses an adhesive, but the polyolefin / polyvinyl alcohol mixed composition resin is not only cheaper than polyamide, but also has much better barrier property, and has about 1 price of EVOH. It has the advantage of having a barrier of EVOH levels of only 3 levels. In addition, the existing polyamide has to be biaxially stretched the film to increase the barrier properties, there is a problem such as requiring a special extruder to make a biaxially stretched film.

An example of the process of making the mixture composition of the present invention into pellets before producing the film, sheet or other molded article is as follows.

First, a plasticizer, a processing aid and an antioxidant are added to polyvinyl alcohol and kneaded at 100 rpm or more in a super mixer or Hansel mixer for at least 5 minutes. The kneaded polyvinyl alcohol composition is dried in a dehumidifying dryer at 80 to 120 ° C. for at least 3 hours. On the other hand, an initiator, a polymer compatibilizer and a low molecular weight use agent are added to the polyolefin and kneaded at 100 rpm or more in a super mixer or a Hancell mixer for 5 minutes. Each separately kneaded polyvinyl alcohol composition and polyolefin composition are kneaded again in a super mixer or one-cell mixer, extruded in a twin extruder, and then cut into pellets.

The film of the present invention may be obtained by first preparing in the form of pellets as described above and then melt processing or directly melting the mixed composition. The film of the present invention can be produced into a film by a general melt film forming method such as a blowing film forming method or a T-die melt molding method (or casting molding method). The resulting film can be used both in the stretched or unstretched state. In the blow molding method, biaxial stretching is possible directly by the tubular method. In the T-die melt molding method, the biaxial stretching is performed simultaneously or sequentially after the production of the unstretched film. Preferably, the polyolefin and polyvinyl alcohol mixed composition is made by a T-die melt molding method, and the film is biaxially stretched sequentially or simultaneously.

The content of vinyl alcohol units in the polyvinyl alcohol resin is an important variable for the barrier properties of oxygen and organic solvents. That is, the crystal structure is present as a monoclinic crystal structure only when the content (saponification degree) of the vinyl alcohol unit is 60 mol% or more to have a blocking effect. Polyvinyl alcohol is usually a crystalline polymer having a monoclinic structure because the degree of saponification is 85 mol% or more. However, the degree of crystallinity depends on the degree of saponification. For example, when the saponification degree of polyvinyl alcohol is 87 to 89 mol%, the crystallinity is 12 to 18%, and when the saponification degree is 98 to 99 mol%, the crystallinity is 30 to 40%. Therefore, the barrier property of polyvinyl alcohol with saponification degree of 98 to 99 mol% is more excellent. Unlike metals, polymers generally have low crystallinity, and many polymers contain a mixture of crystalline and amorphous portions. The polymer becomes amorphous (amorphous) by free thermal motion in the molten state, and as the temperature decreases, the molecular motion is relaxed to form a second crystal structure, and the degree of crystallinity varies depending on the processing conditions. Therefore, the degree of saponification and content of polyvinyl alcohol is also important for improving barrier properties, but in the same kind of polyvinyl alcohol, it is more important to increase the crystallinity. Stretching of the film plays an important role in increasing the degree of crystallinity, the greater the draw ratio, the higher the degree of crystallinity, preferably stretched to 3 or more.

When the polyolefin forms a matrix, the moisture permeability can be maintained at the level of the polyolefin, so that the film's barrier property can be easily hot melt adhered to the polyolefin without being affected by moisture, so that only the barrier effect can meet the commercially required level. If satisfied, the unit price of the product can be innovatively lowered with excellent physical properties. For example, in the case of a multilayer film made of polyethylene on both sides, conventionally, five layers of [polyethylene layer / adhesive layer / blocking layer / adhesive layer / polyethylene layer] were required, but according to the present invention, [polyethylene layer / blocking layer / Polyethylene layer] is required only two layers can be omitted, not only can reduce the number of manufacturing process, but also because the expensive adhesive is not used, there is a significant difference in cost. Conventional barrier layers are polyamide and EVOH, and the barrier layer of the present invention means a molten film layer of a polyolefin / polyvinyl alcohol mixed composition. In the case of using polypropylene instead of polyethylene in the above example, since the T-die melt molding method which can maximize the draw ratio which is important for increasing the crystallinity can be applied, biaxial stretching can be performed to maximize the blocking effect.

Therefore, preferably, a plasticizer, a processing aid, an antioxidant, a compatibilizer and an initiator are added to the mixture of 40 to 50% by weight of polyvinyl alcohol and 60 to 50% by weight of polypropylene to knead and knead these, and extruded in a twin extruder to pellet And extruded into a casting film by tee-die melt molding in a single extruder, and then stretched biaxially at the softening point of the film at 140 to 160 ° C. At this time, the greater the draw ratio, the greater the physical properties such as transparency, mechanical properties, barrier properties. After biaxial stretching, heat treatment at 80 to 140 ° C. for several minutes to several tens minutes yields a film that is more resistant to humidity, in which gas and organic solvent barrier properties do not change for a long time even at high humidity. The film thus produced shows superior barrier performance than the conventional barrier film biaxially stretched polyamide film, and may reach a level equivalent to the EVOH level depending on processing conditions. The increase in crystallinity and the improvement in blocking performance and general properties according to the draw ratio are also applied to the blown film.

When polyvinyl alcohol forms a matrix (when the content of polyvinyl alcohol is 50 to 70% by weight), polyvinyl alcohol is positioned on the outer surface of the molten film layer of the polyolefin / polyvinyl alcohol mixed composition, and The moisture absorption rate of vinyl alcohol is up to 20%, which is very high, so it is sensitive to moisture, and the direct contact with moisture in the air during extrusion causes the gas and organic solvent barrier properties to drop dramatically. The form of the multilayer film adhere | attached on both surfaces of is preferable. In order to bond the polyvinyl alcohol of the barrier layer and the polyolefin of the water resistant film layer, an adhesive material is used between the two, or a carboxylic acid group or a silane group is introduced directly into the polyolefin of the water resistant film layer, It is preferable to produce a multilayer film by coextrusion using a compatibilizer. Such multilayer films also have much the same gas and organic solvent barrier properties as EVOH, and are much more cost effective. On the other hand, the film produced by co-extrusion is proportional to the blocking performance of the film according to the draw ratio, the smaller the content of polyvinyl alcohol, the proportional relationship is apparent. When the content of polyvinyl alcohol exceeds 60 to 70% by weight, the blocking performance according to the draw ratio does not show a big difference, while the general physical properties still increase proportionally. Therefore, the draw ratio is preferably 3 X 3 to 5 X 5. This property also applies to both biaxial stretching and blow molding methods.

The present invention also relates to a multilayer film in which a film of another polymer is adhered to one or both sides of a molten film (“blocking layer”) of a polyolefin / polyvinyl alcohol mixed composition.

Examples of the material that adheres to one or both surfaces of the barrier layer include polyolefins, modified polymers or copolymers of polyolefins, or blending resins of polyolefins and other resins. The purpose of introducing other polymers on one or both sides of the barrier layer is to increase the price competitiveness for the same volume or weight by imparting new functionality or by adhering polymers with low resin costs.

When the polyolefin forms a matrix, as described above, in the conventional multilayer film, since the adhesion is possible by heat fusion without the necessary adhesive, the unit cost of the final product is greatly lowered. When the polyvinyl alcohol forms the matrix, the triple co-extrusion is preferable from the first time of manufacturing the barrier film as described above, and lamination may be added as necessary. Such molded products are mainly used for food and medicine, and also for industrial use.

To the multilayer film, a paper layer may be separately attached as necessary. The paper layer is located between the barrier layer and the other film layer, and a separate adhesive layer may be added if necessary. As an example, an adhesive is applied on the barrier layer of the two-layer film made by co-extrusion of the polyolefin / polyvinyl alcohol barrier layer and the polyolefin layer, and the paper layer is adhered by dry lamination and finally The polyethylene is melted and coated on a paper layer. In this case, since it is composed of five layers of [polyolefin layer / blocking layer / adhesive / paper layer / polyethylene layer], it is conventionally made of six layers of [polyolefin layer / adhesive / blocking layer / adhesive / paper layer / polyethylene layer]. Compared to the paper container multilayer film of the one layer has a structure that has the advantage that can shorten the work process. Such molded articles may be used as barrier paper containers such as milk, juices, alcoholic beverages (soju, sake, etc.).

The present invention also relates to a molded article in which the polyolefin / polyvinyl alcohol mixed composition is melt-molded in the form of a sheet or a container rather than in the form of a film. They may be a single melt of a polyolefin / polyvinyl alcohol mixed composition, and may be a multilayer sheet and a multilayer container in which resins composed of other components or polymers, etc., are continuous on one side, both sides or multilayer sides, as in the case of a multilayer film. In the case of sheets, the molding is produced by a triple or five coextrusion method and then commercialized into a container or a tray by thermoforming.

Since the molded article is produced by thermoforming as described above, polypropylene is preferable for the polyolefin of the barrier layer, and polypropylene is also preferable for the polymer introduced on both surfaces. On the other hand, polystyrene excellent in thermoforming can also be bonded to both surfaces of the barrier layer. When used for food, a barrier layer having a polyvinyl alcohol content of 50% by weight or more is preferred, particularly, a barrier layer of 60 to 70% by weight is more preferred, and five-co-extrusion is preferred.

In the case of a container, it is manufactured by blow molding method, and when used for industrial use (pesticide container, paint container, fuel tank, organic solvent container, etc.), a barrier layer having a polyvinyl alcohol content of 30 to 50% by weight is preferable. A barrier layer of 50% by weight is more preferred, and double coextrusion is preferred over barrier layer single extrusion or triple coextrusion or quadruple coextrusion.

Double co-extrusion of the barrier layer and HDPE reduces the cost of the product while eliminating the adhesive layer compared to the conventional HDPE / adhesive / blocking layer (polyamide or EVOH) triple coextrusion, and compared with the triple coextruder. Significantly lower prices for dual coextruders result in lower initial investment and lower floor composition, resulting in higher productivity. In the case of food and pharmaceutical containers, a barrier layer having a polyvinyl alcohol content of 50% by weight or more is preferable, in particular, a barrier layer of 60 to 70% by weight is more preferable, and five co-extrusion is preferable.

When the polyolefin of the barrier layer and the polyolefin of the coating layer are each made of polypropylene, a packaging film, a sheet or a packaging container which can be used in boiling water or a microwave oven may be produced.

Hereinafter, the content of the present invention will be described in more detail with reference to Examples, but the content of the present invention is not limited by the following Examples.

Example 1

30% by weight of polyvinyl alcohol was 20% by weight of plasticizer, 2% by weight of processing aid, 0.05% by weight of antioxidant and super mixer (Super) based on 100% by weight of polyvinyl alcohol with different degrees of saponification and polymerization degree as shown in Table 1 below. 70% by weight of low density polyethylene (LDPE; melt index (MI) = 1, density (ρ) = 0.918) to 1 weight of maleic anhydride, a low molecular weight compatibilizer, based on 100% by weight of LDPE. % And 0.1 wt% of initiator dicumyl peroxide were coated on LDPE and dry blended with a mixture of the polyvinyl alcohol / plasticizer / processing aid / antioxidant in a supermixer. The mixture was dried in a drier at 80 ° C. for 12 hours and then extruded in a twin extruder (Φ40, Dae-A Zinc Co., Ltd.). At this time, the temperature gradient of the extruder is 170 ℃-190 ℃-200 ℃-210 ℃-220 ℃-200 ℃, extruded at 40rpm to make a pellet and then produced in blown film of 600mm width and 45㎛ thickness in a single compressor It was. At this time, the temperature of the extruder was maintained at 220 to 230 ℃, a screw with a compression ratio of 3: 1 was used. Melting point, melting index, yellow index, haze and gas permeability of the resulting film were measured and shown in Table 1 below. The lower the values of yellow index, haze (transparency measurement) and gas permeability, the better the physical properties of the film.

Table 1

Experiment number PVA Plasticizer (phr) Processing aid (phr) Antioxidant (phr) Melt index Yellow index Haze Gas permeability Safflower Degree of polymerization #One 99 2000 Glycerol AX-38 PEP-36 One 5.2 92 154 #2 99 1000 Glycerol AX-38 PEP-36 5 3.1 71 126 # 3 99 1700 Glycerol AX-38 PEP-36 2 3.5 80 133 #4 88 1700 Glycerol AX-38 PEP-36 2 2.6 57 145 # 5 88 600 Glycerol AX-38 PEP-36 10 2.4 58 97

Degree of safflower: mol%

AX-38: Phosphate Processing Aid (Hanong Adeka), Liquid, Viscosity 700cps

PEP-36: phosphate antioxidant (Hanong Adeka), white powder, melting point (237 ℃),

Molecular Weight (663)

Melt Index: Unit (g / 10min, 210 ℃)

Gas permeability: unit (cc / ㎡, atm, 24 hours, 20 ° C, 65% RH)

phr: part per hundred raw material

Example 2

Polyvinyl alcohol (V1) having a degree of saponification of 99 mol% and a polymerization degree of 1,700, polyvinyl alcohol (V2) having a degree of polymerization of 88 mol% and a degree of polymerization of 1,700, and polyvinyl alcohol having a degree of polymerization of 88 mol% and a degree of polymerization of 600 (V3) was dry blended at different ratios to prepare a blown film in the same manner as in Example 1, and the melting point, melt index, yellow index, haze and gas permeability were measured.

TABLE 2

Experiment number Blending ratio Melt index Yellow index Haze Gas permeability V1 V2 V3 # 6 70 - 30 2 3.9 70 149 # 7 50 - 50 4 3.4 67 112 #8 30 - 70 7 3.0 63 106 # 9 - 50 50 5 2.9 59 118

Blending ratio: unit (weight ratio)

Example 3

A polyvinyl alcohol mixture having a molecular weight of 99 mol% and having a polymerization degree of 1,700 and a polyvinyl alcohol mixture having a molecular weight of 88 mol% and a polymerization ratio of 600 with a polymerization ratio of 50 to 50 in a weight ratio of 50 to 50 After dry blending 70% by weight of LDPE in the same manner as in Example 1, it was casted using Bravender's plasti-coder single extruder while maintaining the temperature at 230 ° C. ) Was prepared. At this time, the gap of the T-die was fixed to 1 mm, the screw to 10 rpm, and the take-off speed to 0.8 m / min, respectively. The molecular weight change of LDPE is expressed as melt index (MI).

TABLE 3

Experiment number LDPE (MI) Melt index Yellow index Haze Gas permeability # 10 1.6 7 5.3 87 92 # 11 2 9 4.2 89 91 # 12 3 10 3.5 92 89

Melt Index of LDPE: Unit (g / 10min, 190 ℃)

Example 4

Polyvinyl alcohol mixture of polyvinyl alcohol having a degree of saponification of 99 mol% and a polymerization degree of 1,700 and polyvinyl alcohol having a degree of polymerization of 88 mol% and a polymerization degree of 600 at a weight ratio of 50 to 50 and LDPE (MI = 1, ρ) = 0.918), the casting film was prepared in the same manner as in Example 3, and the yellow index, the haze, and the gas permeability were measured.

Table 4

Experiment number LDPE (% by weight) PVA (% by weight) Melt index Yellow index Haze Gas permeability # 13 50 50 10 4.3 92 85 # 14 30 70 15 5.2 97 95

Example 5

Change the type of plasticizer to 30% by weight of polyvinyl alcohol having a degree of saponification of 88% and polymerization degree of 600 and 70% by weight of LDPE, and add 20phr of plasticizer, 20phr of processing aid, and 0.05phr of antioxidant in the same manner as in Example 1. To a pellet, and a casting film was prepared in the same manner as in Example 3 to measure yellow index, haze and gas permeability.

Table 5

Experiment number LDPE: PVA (wt%) Plasticizer (phr) Melt index Yellow index Haze Gas permeability # 15 70:30 Glycerol / Water (85/15) 8 2.8 64 77 # 16 70:30 Triethylene glycol 9 3.2 75 81 # 17 70:30 Trimethylolpropane 9 3.1 73 79

Example 6

A casting film was prepared in the same manner as in Example 5 while varying the amount of plasticizer glycerol added to 30% by weight of polyvinyl alcohol having a degree of saponification of 88 and a polymerization degree of 600 and 70% by weight of LDPE, and thus yellow index, haze and gas permeability. Was measured.

Table 6

Experiment number LDPE: PVA (wt%) Added amount of glycerol Melting Point (℃) Melt index Yellow index Haze Gas permeability # 18 70:30 30 156 12 1.8 51 122 # 19 70:30 10 173 4 5.1 84 63

Addition amount of glycerol: unit (phr)

Example 7

Blown films were prepared in the same manner as in Example 1 by changing the type and amount of the processing aid and the antioxidant to 30% by weight of polyvinyl alcohol having a degree of saponification of 88% by weight and 1,700 degree of polymerization and 70% by weight of LDPE. Processing aids and antioxidants did not affect gas permeability, so only yellow index and haze were measured.

TABLE 7

Experiment number Processing aid Antioxidant Plasticizer Yellow index Haze Kinds Amount Kinds Amount # 20 FC-113 2 PEP-24G 0.05 Glycerol 1.8 42 # 21 FC-113 2 P 0.05 Glycerol 2.3 49 # 22 AX-38 2 PEP-24G 0.05 Glycerol 2.1 53 # 23 FC-113 4 P 0.1 Glycerol 2.0 45 # 24 MG-ST 4 PEP-36 0.1 Glycerol 2.5 59

FC-113: Acrylic Oligomer Processing Aid (Hanong Adeka), White Powder, Softening Point (110 ℃)

MG-ST: magnesium stearate (Hannong Adeka), white powder, melting point (130 ℃)

PEP-24G: (Hande Deca), White Particles, Melting Point (165 ℃), Molecular Weight (604)

P: (Hande Deca), liquid, viscosity 2500cps

Example 8

The blown film was prepared in the same manner as in Example 1 by changing the type and amount of compatibilizer to 30% by weight of polyvinyl alcohol having a degree of saponification of 88 and a polymerization degree of 600 and 70% by weight of LDPE. And gas permeability.

Table 8

Experiment number Compatibilizer Melt index Yellow index Haze Gas permeability Kinds Amount # 25 EVA 20 7 5.4 95 540 # 26 A-1600 20 14 2.5 62 91 # 27 A-1600 10 16 3.1 69 105 # 28 A-1600 5 17 3.4 72 130 # 29 VTMO + DCP (1) + (0.05) 10 2.3 57 83 # 30 A-1600 + DCP (10) + (0.05) 15 2.9 63 77 # 31 A-1600 + DCP (5) + (0.05) 17 3.2 67 85

Plasticizer: Glycerol (20 phr)

Processing aid: AX-38 (2phr)

Antioxidant: PEP-36 (0.05phr)

A-1600: Maleic anhydride modified product of ethylene-ethyl acrylate copolymer (Japanese oil company)

VTMO: Vinyltrimethoxy-silane

DCP: Dicumyl Peroxide

Example 9

Polyvinyl alcohol was prepared using a mixture containing polyvinyl alcohol having a degree of saponification of 88 mol% and a polymerization degree of 1,700 and polyvinyl alcohol having a degree of polymerization of 88 mol% and a degree of polymerization of 600 in a 50:50 weight ratio. The casting film was manufactured by the same method as 3, and yellow index, haze, and gas permeability were measured. The difference between the examples is that the casting film was molded by varying the extrusion temperature.

Table 9

Experiment number Plasticizer (phr) Processing aid (phr) Antioxidant (phr) Film thickness Melt index Extruder temperature Yellow index Haze Gas permeability # 32 Glycerol AX-38 PEP-36 135 2 210 2.9 94 96 # 33 Glycerol AX-38 PEP-36 130 4 190 2.5 91 174

Thickness of film: unit (μm)

Extruder temperature: unit (℃)

Example 10

Polyvinyl alcohol having a degree of saponification of 88 mol% and a polymerization degree of 600 was melt-extruded in an LDPE and a twin extruder in the same formulation as in Example 1, followed by LDPE (MI = 3, ρ) in a three-layer extruder. = 0.918) and the double cast film was coated to measure the yellow index, haze and gas permeability. At this time, the conditions of the triple extruder are the same as those of Example 3.

Table 10

Experiment number Content (% by weight) Film thickness (㎛) Yellow index Haze Gas permeability PVA LDPE # 34 30 70 141 1.5 26.4 74 # 35 40 60 143 1.9 28.6 55

Example 11

Example 10 was repeated with 70 wt% polyvinyl alcohol and 30 wt% LDPE (MI = 1, p = 0.918). The difference from Example 10 is that 1 phr of low molecular compatibilizer and 0.1 phr of initiator dicumyl peroxide are coated on LDPE before co-extrusion of LDPE (MI = 3, ρ = 0.918) used to coat both sides. The reaction was carried out in a twin extruder to introduce carboxylic acid functional groups into the LDPE, and then extruded in triplicate to enable the adhesion of the LDPE / polyvinyl alcohol layer without the use of an adhesive.

Table 11

Experiment number Content (% by weight) Film thickness (㎛) Yellow index Haze Gas permeability PVA LDPE # 36 70 30 154 2.1 43 15

Example 12

Examples 10 and 11 were repeated except that triple extrusion blown films were prepared. At this time, the extrusion conditions of the triple extrusion blower is the same as in Example 1.

Table 12

Experiment number Content (% by weight) Film thickness (㎛) Yellow index Haze Gas permeability PVA LDPE # 37 30 70 43 1.3 14.1 44 # 38 40 60 49 1.6 15.1 29 # 39 70 30 57 1.9 22 9

Example 13

Examples 10 and 11 were repeated to prepare the casting film. The difference from Examples 10 and 11 is that LDPE (MI = 1, p = 0.918), which forms a mixed composition of the barrier layer, and LDPE resin (MI = 3, p = 0.918), which forms a coating layer, are PP (MI = 2, homopoly). Propylene) and PP resin (MI = 4, homo polypropylene). In the following # 42, VTMO was introduced into the PP (MI = 4, homopolypropylene) of the coating layer to facilitate extrusion with the PP / polyvinyl alcohol layer and triple extrusion.

Table 13

Experiment number Content (% by weight) Film thickness (㎛) Yellow index Haze Gas permeability PVA PP # 40 30 70 208 1.8 27.5 75 # 41 40 60 209 1.9 28.9 52 # 42 70 30 213 2.1 41 16

Example 14

40 wt% of the polyvinyl alcohol content and 60 wt% of the PP content obtained in Example 13 were laminated in a press with a thickness of 1 mm, and then biaxially stretched in a 150 ° C. atmosphere to measure gas permeability.

Table 14

Experiment number Drawing ratio (MD X TD) Film thickness (㎛) Yellow index Haze Gas permeability # 43 5 X 5 32 0.8 3.3 3.7 # 44 5 X 9 24 0.7 3.1 1.4 # 45 7 X 9 21 0.5 2.5 0.8

Example 15

88% by weight of saponification degree and 40% by weight of polyvinyl alcohol having a degree of polymerization of 600 and the same kind of plasticizer, processing aid, and antioxidant as in Example 1, were mixed into A-1600 (10 phr) and DCP (0.05 phr). 60 hours by weight of coated HDPE (MI = 0.3, p = 0.958) was dried in an 80 ° C. dryer for 12 hours and then extruded in a twin extruder to prepare pellets. In a double-layer blow molding extruder (Daechang Machinery Φ60, Φ35), HDPE (MI = 0.3, ρ = 0.958) was injected into the Φ60 extruder, and HDPE / polyvinyl alcohol was added to the Φ35 extruder, thereby forming a 500 ml container. The thickness of the vessel is 0.8 mm, the outer layer of HDPE is 0.72 mm and the barrier layer of inner layer HDPE / polyvinyl alcohol is 0.08 mm. The toluene is contained in this container and the inlet is sealed with aluminum and left for 2 weeks in an oven at 50 ° C., and then cycled for 3 weeks in a low temperature chamber at -10 ° C., followed by measuring the reduced weight with respect to the initial weight. % Loss was calculated. The weight loss was 0.3% and there was no change in container appearance.

As described above, the present invention, due to the unique morphology of the polyolefin / polyvinyl alcohol mixed composition resin, has a gas and organic solvent barrier properties, and also has a water resistance and can be melt processed in a conventional molding machine and low price As such, it provides an excellent barrier film comparable to expensive EVOH. In addition, when using such a film as part of a multi-layered product does not require a separate adhesive can reduce the number of manufacturing processes. On the other hand, the principle of the multi-layer film can be applied to a multi-layer sheet or a multi-layer container, it is possible to obtain excellent physical properties and cost reduction effect in the field requiring the barrier properties. Such a film, a multilayer film, a sheet, a container, etc. may be used in various fields such as packaging for food, pharmaceuticals, pesticides, or paint storage, fuel tanks or large-scale chemical storage of automobiles.

Claims (18)

(A) 1 to 80% by weight of polyolefin and 20 to 99% by weight of polyvinyl alcohol, (B) 3 to 40% by weight of a polymeric compatibilizer, or 0.1 to 5% by weight of a low molecular compatibilizer and 0.01 to 0.5% by weight of an initiator causing a reaction of the compatibilizer with a polyolefin, based on 100% by weight of polyolefin, or the polymer A mixture of a system compatibilizer and a low molecular compatibilizer and an initiator, (C) 3 to 50% by weight of plasticizer based on 100% by weight of polyvinyl alcohol, (D) 1 to 10% by weight of the processing aid, based on 100% by weight of polyvinyl alcohol, and (E) A gas and organic solvent barrier film made by melting a mixed composition containing 0.01 to 5 wt% of an antioxidant based on 100 wt% of polyvinyl alcohol. The gas and organic solvent barrier film of claim 1, wherein the polyolefin is 50 to 60 wt% and the polyvinyl alcohol is 50 to 40 wt%. The method according to claim 1 or 2, wherein the plasticizer is glycerin, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, a mixture of glycerin and water, polyethylene glycol, polypropylene glycol, trimetholpropane, triethylene glycol, Gas and organic solvent barrier film which is a mixture of one or two or more selected from the group consisting of isopropanol. The process aid according to claim 1 or 2, wherein the processing aid is selected from the group consisting of acryl oligomers, phosphates, calcium stearate, zinc stearate, magnesium stearate, stearic acid, paraffin wax, and polyethylene wax. Gas and organic solvent barrier film which is a mixture of the above. The phenolic antioxidant, the phosphate antioxidant, the calcium-zinc-tin organic mixture antioxidant, the dioctyltin malate type antioxidant, and the dioctyltin mergentide of Claim 1 or 2, Gas and organic solvent barrier film, which is a mixture of one or two or more selected from the group consisting of antioxidants. 3. The polymer compatibilizer according to claim 1 or 2, wherein the polymer compatibilizer is ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-ethylacrylate copolymer, ethylene-alkylacrylate-acrylic acid copolymer, ethylene-alkylmetha. Gas and organic solvent barrier films, which are one or two or more mixtures selected from the group consisting of acrylate-methacrylic acid copolymers, ethylene-butylacrylate copolymers, ethylene-vinylacetate copolymers, or modifications thereof. The gas and organic solvent barrier film according to claim 6, wherein the polymeric compatibilizer is a maleic anhydride modified product of an ethylene-ethyl acrylate copolymer. The low molecular weight compatibilizer according to claim 1 or 2, wherein the low molecular weight compatibilizer is acrylic acid, methacrylic acid, maleic acid, fmaric acid, itaconic acid, crotonic acid, sorbic acid, or anhydrides thereof; Or vinyltrimethoxy silane, vinyltrimethoxymethoxyethoxy silane, vinyltriethoxy silane, gamma- (meth) acryloxypropyltrimethoxy silane, gamma- (meth) acryloxypropyltriethoxy silane, vinyl-tris A gas and organic solvent barrier film that is one or more mixtures selected from the group consisting of (beta-methoxyethoxy) silane and vinyltriacetoxy silane. 3. The method according to claim 1 or 2, wherein the initiator is selected from the group consisting of acyl peroxide, dialkyl or dialkyl peroxide, peroxy ester, hydroperoxide, ketone peroxide and azo compound initiators. A gas and organic solvent barrier film that is one or a mixture of two or more selected. A cast film or blow-molded blown film obtained by extruding the barrier film of claim 1. The stretched film which biaxially stretched the film of Claim 10. The stretched film according to claim 11, wherein the polyolefin component of the barrier film is 50 to 60% by weight of polypropylene. A multilayer film in which one or more layers of polyolefins, modified polymers of polyolefins, or blending resins of polyolefins and other polymers are bonded to one or both surfaces of the film of claims 1 to 12. The multilayer film according to claim 13, wherein the film is biaxially stretched. The multilayer film of claim 13, further comprising a paper layer attached to one or both surfaces of the barrier film. A molded article having the same structure as the barrier film of claim 1. A multilayer molded article wherein one or more of the molded article of claim 16 is adhered to at least one polyolefin, a modified polymer of polyolefin, or a blending resin of polyolefin and another polymer. 18. The multilayer molded article according to claim 17, wherein the adhesion is performed by thermal fusion.