A RESINOUS COMPOSITION, MOLDED ARTICLES AND CONTAINERS MADE THEREOF AND ITS USE

Abstract: A resinous composition which comprises (A) 95 to 50 parts by weight of a saponified product of ethylene-vinyl acetate copolymer and (B) 5 to 50 parts by weight of a product formed by modifying an ethylene-vinyl carboxylate ester copolymer or an ethylene-acrylate ester copolymer with an α,β-unsaturated carboxylic acid or anhydride thereof. This resinous composition can be made by melt extrusion to form a molded article which is superior in impact resistance as compared to that formed from the component (A) alone. The resinous composition can also be applied in an inner layer or interlayer of a laminated con­ tainer. This container is suitable for making bottles for food and agricultural chemicals because of its outstanding im­ pact resistance, organic solvent resistance, and oxygen barrier properties.

Description: The present invention relates to resinous compositions based on a saponified product of an ethylene-vinyl acetate copolymer (referred to as EVOH hereinafter) and to impact-resistant molded articles and containers made of said resinous compositions. EVOH is a thermoplastic resin which is incomparably superior to other resins in oil resistance, organic solvent resistance, stiffness, hardness, abrasion resistance, and oxygen barrier properties. However, it has a disadvantage of being poor in impact resistance and being hard and brittle. There are some known methods for improving the impact resistance of EVOH by blending it with a rubber-like material. For example, there is disclosed in Japanese Patent Publication No. 3185/1967 the improvement by blending it with an ethylene-vinyl carboxylate copolymer or ethylene-acrylate copolymer. These methods are still inadequate for achieving an improvement in impact resistance and moldability because of the poor dispersion of the resin to be blended. Another example of the blended EVOH is disclosed in Japanese Patent Laid-open No. 131033/1980. According to the disclosure, a resinous composition is produced by blending 50 to 97 parts by weight of EVOH and 50 to 3 parts by weight of a thermoplastic polyolefin copolymer having carbonyl groups(-C=O) derived from an unsaturated carboxylic acid or an anhydride thereof. (Examples of such copolymers include maleic anhydride-grafted polyethylene, ionomer resins, ethylene-vinyl acetate copolymers and ethylene-acrylate copolymers.) This resinous composition finds use as packaging material that can be easily cut with an edged tool. Even this resinous composition has no satisfactory impact resistance and gel forming occurs during molding. Further, Japanese Patent Laid-open No.86579/1975 discloses a composition composed of EVOH and a polyolefin (e.g., polyethylene) modified with an unsaturated polybasic oarboxylic acid. It also discloses a multi-layered blow-molded container made by coextrusion of the composition and a polyolefin. The composition still has the same disadvantages as mentioned above. This will be more clearly understood from the comparative examples mentioned later. In EP-A-0 152 180 a polymer alloy is disclosed which is a mixture of grafted and ungrafted polyvinyl alcohol polymers. A polymer alloy is prepared by reacting a polyvinyl alcohol polymer which has a degree of hydrolysis of less than 98 mole % with less than the stoichiometric amount of a functional olefin polymer containing functional groups which are reactive with the hydroxyl groups of the polyvinyl alcohol polymer. This polymer alloy exhibits excellent moisture resistance and good separation of the melting and decomposition points without a significant loss of gas barrier properties. Melt-blending of the polymer alloy with a compatible polyolefin blending resin further improves moisture resistance. The technical problem underlying the present invention is to provide resinous compositions based on EVOH which have improved impact resistance and which are comparable to unmodified EVOH in oil resistance, organic solvent resistance, and oxygen barrier properties and to provide molded articles produced by melt-processing of the resinous compositions and also containers of multilayered structure formed by coextrusion of the resinous compositions and a thermoplastic resin. It has been found that the impact resistance of EVOH is greatly improved when a product obtained by adding a C₃-C₁₀ α,β-unsaturated carboxylic acid or an anhydride thereof to an ethylene-vinyl carboxylate ester copolymer or an ethylene-acrylate ester copolymer is being incorporated with the EVOH. The present invention is based on these findings. The resinous compositions of this invention are comparable to unmodified EVOH in oil resistance, organic solvent resistance, and oxygen barrier properties. The present invention provides resinous compositions which comprise (A) 95 to 50 parts by weight of EVOH and (B) 5 to 50 parts by weight of modified ethylene-vinyl carboxylate ester copolymer or a modified ethylene-acrylate ester copolymer comprising ethylene, a vinyl carboxylate ester or an acrylate ester, and an C₃-C₁₀ α,β-unsaturated carboxylic acid or acid anhydride, wherein said modified ethylene-vinyl carboxylate ester copolymer or modified ethylene-acrylate ester copolymer contains 60 to 95 mol% of ethylene and X mol% of an α,β-unsaturated carboxylic acid or acid anhydride and has a melt index of Y g/10 min (190°C, 2160 g), where X and Y are those values that satisfy the following equations [I] and [II]. 0.01 < x < 3 [I] 0.01·Z < Y < 100 (Z + 10·X) [II] where Z is the melt index (Z g/10 min (190°C, 2160 g)) of EVOH. The EVOH used in the present invention contains 20 to 60 mol%, preferably 25 to 60 mol% of ethylene and has a degree of saponification greater than 95 mol%. If the ethylene content in EVOH is lower than 20 mol%, the resulting composition has a high molding temperature which is close to the decomposition temperature, which makes molding difficult. If the ethylene content in EVOH is higher than 60 mol%, the resulting composition is poor in oil resistance and stiffness. If the degree of saponification is lower than 95 mol%, the resulting composition loses its oil resistance and heat stability. The modified ethylene-vinyl carboxylate ester or modified ethylene-acrylate ester copolymer used in this invention contains 60 to 95 mol% of ethylene and X mol% of an α,β-unsaturated carboxylic acid or acid anhydride and has a melt index of Y g/10 min (190°C, 2160 g), where X and Y are those values that satisfy the following equations [I] and [II]. 0.01 < X < 3 [I] 0.01·Z < Y < 100 (Z + 10·X) [II] where Z is the melt index (Z g/10 min (190°C, 2160 g)) of EVOH. If the content (X) of the α,β-unsaturated carboxylic acid or acid anhydride is less than 0.01 mol%, the modified ethylene-vinyl carboxylate ester or modified ethylene-acrylate ester copolymer has a poor dispersion at the time of blending and is consequently poor in impact resistance. If it exceeds 3 mol%, the modified ethylene-vinyl carboxylate ester or modified ethylene-acrylate ester copolymer becomes excessively viscous during the blending operation and the resulting composition exhibits a poor moldability and other physical properties. In addition, it is necessary that X, Y, and Z satisfy the above-mentioned formula [II], where X is the amount (mol%) of an α,β-unsaturated carboxylic acid or acid anhydride, Y is the melt index of the modified ethylene-vinyl carboxylate ester or modified ethylene-acrylate ester copolymer, and Z is the melt index of the EVOH. If they are outside the values specified by the equation [II], the α,β-unsaturated carboxylic acid or its anhydride do not exhibit a good effect and no great improvement is made with respect to dispersion and to impact resistance. The modified ethylene-vinyl carboxylate ester copolymer used in this invention contains a vinyl carboxylate ester component represented by the formula (where R is a linear or branched alkyl group having 1 to 20 carbon atoms.) Typical examples of the vinyl carboxylate ester include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl octanoate, vinyl dodecanoate, vinyl stearate, and vinyl arachinate. Preferable among them is vinyl acetate. The modified ethylene-acrylate ester copolymer used in this invention contains one acrylate ester component represented by the formula (where R' is a linear or branched alkyl group having 1 to 20 carbon atoms.) Typical examples of the acrylate ester include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexylacrylate, dodecyl acrylate, octadecyl acrylate, and eicosyl acrylate. Among them methyl acrylate and ethyl acrylate are preferred. The above-mentioned vinyl carboxylate ester and acrylate ester lead to the same effect of improving the impact resistance of the resinous composition. The former permits the resinous composition to keep its impact strength even after immersion in a surfactant solution or an organic solvent for a long time. Therefore, the resinous compositions of the invention are very suitable for bottles for cosmetics, liquid detergents, and agricultural chemicals. On the other hand, the acrylate ester, which has a higher decomposition temperature than the vinyl carboxylate ester, imparts improved characteristics concerning the moldability at high temperatures and impact resistance at low temperatures to the resinous compositions. The modified ethylene-vinyl carboxylate ester copolymers and modified ethylene-acrylate ester copolymers used in this invention contain an α,β-unsaturated carboxylic acid or acid anhydride having 3 to 10 carbon atoms. It includes, for example, acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, itaconic acid, maleic anhydride, and itaconic anhydride. Maleic anhydride and itaconic anhydride are preferred. The resinous oompositions of this invention comprise 95 to 50 parts by weight, preferably 95 to 60 parts by weight, of EVOH and 5 to 50 parts by weight, preferably 5 to 40 parts by weight of the modified ethylene-vinyl carboxylate ester copolymer or modified ethylene acrylate ester copolymer. The preferred amount of modified ethylene-vinyl carboxylate ester copolymer is 5 to 40 parts by weight, and the preferred amount of modified ethylene-acrylate ester copolymer is 5 to 30 parts by weight. If the amount of modified ethylene-vinyl carboxylate ester copolymer or modified ethylene-acrylate ester copolymer is less than 5 parts by weight, the resulting resinous composition is not sufficiently improved in impact resistance, and if the amount is in excess of 50 parts by weight, the superior oil resistance and stiffness of EVOH is impaired. The modified ethylene-vinyl carboxylate ester copolymer or modified ethylene-acrylate ester copolymer used in this invention may be produced in a per se known manner. It should preferably be produced by grafting an α,β-Unsaturated carboxylic acid or an anhydride thereof on an ethylene-vinyl carboxylate ester copolymer or an ethylene-acrylate ester copolymer. In the process of producing the modified ethylene-vinyl carboxylate ester copolymer or modified ethylene-vinyl carboxylate ester copolymer, a vinyl monomer may be copolymerized in an amount less than 5 mol% without any adverse effect on the resinous composition of this invention. Also, in the process of producing the modified ethylene-vinyl carboxylate ester copolymer or modified ethylene-vinyl carboxylate ester copolymer, the former may be incorporated with an unmodified ethylene-vinyl carboxylate ester copolymer, or the latter may be incorporated with an unmodified ethylene-acrylate ester copolymer. In the process of blending EVOH with other components, the modified ethylene-vinyl carboxylate ester copolymer and an unmodified ethylene-vinyl carboxylate ester copolymer may be blended simultaneously, or the modified ethylene-acrylate ester copolymer and an unmodified ethylene-acrylate ester copolymer may be blended simultaneously. The blending of EVOH with the modified ethylene-vinyl carboxylate ester copolymer or a modified ethylene-acrylate ester copolymer may be accomplished by the use of a Banbury mixer or a single- or twin-screw extruder. In the process of blending, other additives may be added in such an amount that the action and effect of this invention are not impaired. Examples of such additives include one or many of the following compounds:antioxidants, ultraviolet light absorbers, plasticizers, antistatic agents, slip agents, coloring agents, fillers, and other polymeric compounds. Specific examples of the additives are as follows: Antioxidant: 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-cresol, 4,4'-thiobis-(6-t-butylphenol), 2,2'-methylene-bis(4-methyl-6-t-butylphenol, octadecyl-3-(3'-5'-di-t-butyl-4-hydroxyphenyl)propionate, and 4,4'-thiobis-(6-t-butylphenol). Ultraviolet light absorber: Ethyl-2-cyano-3,3'-2-diphenylacrylate, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, and 2-hydroxy-4-octoxybenzophenone. Plasticizer: Dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, and phosphate ester. Antistatic agent: Pentaerythritol monostearate, sorbitan monopalmitate, sulfonated oleic acid, polyethylene oxide, and carbowax. Slip agent: Ethylene bis-stearamide and butyl stearate. Coloring agent: Carbon black, phthalocyanine, quinacridone, indoline, azo-pigment, titanium oxide, and red oxide. Filler: Glass fiber, asbestos, mica, wollastonite, calcium silicate, aluminum silicate, and calcium carbonate. The resinous compositions of this invention can be molded to form a film, sheet, tube, and bottle and any other desired shape by using a known melt extrusion molding machine, compression molding machine, transfer molding machine, injection molding machine, blow molding machine, thermoforming machine, rotational molding machine, or dip molding machine. The extrusion temperature for molding should be properly selected according to the type and molecular weight of the resins, the formulation of the composition, and the performance of the extruder. It is usually in the range of 180 to 260 °C. The resinous compositions of this invention can be molded by coextrusion with a proper thermoplastic resin (e.g., polyethylene terephthalate, polyamide, polypropylene, polyethylene, polycarbonate, polystyrene, and polyvinyl chloride). The coextrusion provides laminated moldings which are superior in impact resistance. The resinous compositions of this invention is also useful as the inner layer or interlayer of a container (bottle) made of one of the above-mentioned thermoplastic resins. The multilayered bottles can be produced by the direct blow molding (in which bottles are made from a coextruded multilayered parison), by cold parison technique (in which multilayered pipes (parisons) are made by coextrusion and subsequently the parisons are processed into bottles by biaxial orientation), or by injection blow molding with multiple layers. The bottles produced as mentioned above are superior in resistance to chemicals and organic solvents contained in the case where the inner layer is made of a resinous composition of this invention. Therefore, the bottles are suitable as containers for organic liquids, cosmetics and agricultural chemicals. The application of the resinous compositions of this invention is not limited to bottles and containers. They can be processed to a laminated film or sheet by coextrusion with one of the above-mentioned thermo-plastic resins. In this case, a resinous composition may be used as the interlayer. The laminate (sheet) containing an interlayer of a resinous composition of the invention can be processed into cups or similar containers by deep draw forming. The laminate (film) with the interlayer of the resinous composition will find use e.g. as packaging material for wine and photograph developing solutions. In the production of the above-mentioned laminates (e.g. bottles, tubes, sheets, and films), it is possible to use an adhesive to bond the layer of the resinous composition of this invention to the layer of the thermoplastic resin. The choice of this interlaminar adhesive is not specifically restricted as long as it firmly bonds the two layers together. A preferred product is obtained by modifiying (e.g. grafting) a thermoplastic resin (e.g. polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and ethylene-acrylate ester copolymer) with 0.005 to 5 wt% of an unsaturated carboxylic acid or acid anhydride (e.g. maleic anhydride). The invention is now described in more detail with reference to the following examples. The test methods and evaluation methods used in the examples and comparative examples are as follows: Melt index (MI) : Expressed in terms of the amount of resin which emerges from the melt indexer for 10 minutes when a load of 2160 g is applied at 190°C according ASTM D-1238. Izod impact strength : Measured for bone-dry notched specimens according to ASTM D-256 at 20°C. Falling ball impact test: A 3.3 kg weight is being dropped on a flat specimen measuring 100 mm x 100 mm x 2 mm according to JIS K7211, and the falling height is increased gradually to a point where 50% of the specimens tested are broken. This height is recorded. Dropping test: A blow-molded bottle filled with water and immediately stoppered thereafter is being dropped in the vertical position from various heights onto a concrete floor at 20°C and 65%RH (relative humidity). The same bottle is being dropped ten times at maximum or as many times as can be repeated until the bottle is broken. The falling height and the number of repetition are recorded. This test is performed by using ten bottles and the result is indicated by the average value (integer). Loss of content : A 500 ml blow-molded bottle is filled with 500 ml of xylene, and the filled bottle is allowed to stand at 50°C for one month. The change in weight is recorded. Drop bursting test : A 10-liter blow-molded container filled with 10 liters of water and immediately stoppered thereafter is being dropped in the vertical position from various heights onto a concrete floor at 20°C and 65%RH. The same container is being dropped ten times at maximum or as many times as can be repeated until the container is broken. The falling height and the number of repetition are recorded. This test is performed by using ten containers and the result is indicated by the average value (integer). EXAMPLE 1 EVOH specified below (1) and a modified ethylene-vinyl carboxylate ester copolymer specified below (2) were blended with each other at different blending ratios at 220°C for 5 minutes by using a laboratory plast mill made by Toyo Seiki Co., Ltd. (1) Content of ethylene: 31 mol% Degree of saponification: 99.6% Melt index: 1.3 g/10 min (190°C and 2160 g) (2) Modified copolymer prepared by grafting maleic anhydride onto an ethylene-vinyl acetate copolymer. Content of ethylene: 90 mol% Content of vinyl acetate: 9.3 mol% Content of maleic anhydride: 0.7 mol% Melt index: 6 g/10 min (190°C, 2160 g) The resulting blend was compression molded at 220 °C by using a standard mold. The molded article measuring 63,5 mm x 12,7 mm x 3,18 mm was examined for Izod impact strength. The results are shown in Table 1. COMPARATIVE EXAMPLE 1 The molded test piece was prepared from the EVOH alone which was used in Example 1. The Izod impact strength of this test piece (with notch) was 1.1 kg·cm/cm. COMPARATIVE EXAMPLE 2 90 parts by weight of the same EVOH as used in Example 1 and 10 parts by weight of ethylene-vinyl acetate copolymer containing 88 mol% of ethylene and having a melt index of 6 g/10 min (at 190°C, 2160 g) were blended and the resulting blend was examined in the same manner as in Example 1. The Izod impact strength of the test piece was 4.7 kg·cm/cm. COMPARATIVE EXAMPLE 3 The same test as in Example 1 was performed except that the blending ratio was changed. The amount of EVOH was 97 parts by weight and the amount of modified ethylene-vinyl carboxylate ester copolymer was 3 parts by weight. The Izod impact strength of the test piece (with notch) was 3.0 kg·cm/cm. EXAMPLE 2 The same EVOH as used in Example 1 and a modified ethylene-vinyl carboxylate ester copolymer specified below were dry-blended with each other at a blending ratio of 90 parts by weight to 10 parts by weight, followed by mixing and pelletizing by a 40 mm extruder. Modified copolymer obtained by grafting maleic anhydride onto an ethylene-vinyl acetate copolymer. Content of ethylene: 88 mol% Content of vinyl acetate: 11.3 mol% Content of maleic acid: 0.7 mol% Melt index: 0.8 g/10 min (190°C, 2160 g) The resulting pellets were injection molded at 220°C to prepare test pieces for Izod impact strength, each measuring 63.5 mm x 12.7 mm x 3.18 mm and test pieces for falling ball impact test, each measuring 10 mm x 10 mm x 2 mm. The results are shown in Table 2. COMPARATIVE EXAMPLE 4 The test pieces for Izod impact strength, each measuring as in example 2 and test pieces for falling ball impact test, each measuring 10 mm x 10 mm x 2 mm, were prepared by injection molding at 220°C from the EVOH alone which was used in Example 1. The results are shown in Table 2. COMPARATIVE EXAMPLE 5 A blend was made from 90 parts by weight of the same EVOH as used in Example 1 and 10 parts by weight of modified low-density polyethylene (containing 0.1 mol% of maleic anhydride and having a melt index of 1.3 g/10 min) produced by grafting maleic anhydride onto low-density polyethylene. The resulting blend was examined in the same manner as in Example 2. The results are shown in Table 3. COMPARATIVE EXAMPLE 6 A blend was made from 90 parts by weight of the same EVOH as used in Example 1 and 10 parts by weight of ionomer resin ("Surlyn® 1707" made by duPont). The resulting blend was examined in the same manner as in Example 2. The results are shown in Table 3. EXAMPLE 3 EVOH specified below (1) and a modified ethylene-acrylate ester copolymer specified below (2) were blended with each other at a blending ratio of 90 parts by weight to 10 parts by weight. (1) Content of ethylene: 44 mol% Degree of saponification: 99.6% Melt index: 6.0 g/10 min (190°C and 2160 g) (2) Modified copolymer obtained by grafting maleic anhydride onto an ethylene-ethyl acrylate copolymer. Content of ethylene: 85 mol% Content of ethyl acrylate: 14.9 to 13 mol% Content of maleic anhydride: 0.1 to 2 mol% Melt index: 0.7 g/10 min (190°C, 2160 g) The resulting blend was examined in the same manner as in Example 1. The results are shown in Table 4. COMPARATIVE EXAMPLE 7 Example 3 was repeated except that the modified ethylene-acrylate ester copolymer was replaced by the one containing 0 mol%, 0.005 mol%, or 3.5 mol% of maleic anhydride. The results are shown in Table 4. In the case of modified ethylene-acrylate ester copolymer containing 3.0 mol% of maleic anhydride, there was a tendency that the torque of the blender increases during mixing and the composition is slightly colored. The improvement in impact strength was almost the same as that in the case where maleic anhydride is not used. EXAMPLE 4 The same EVOH as used in Example 1 and a modified ethylene-vinyl carboxylate ester copolymer specified below were blended with each other at a blending ratio of 90 parts by weight to 10 parts by weight in the same manner as in Example 1. Modified copolymer obtained by grafting maleic anhydride onto an ethylene-vinyl acetate copolymer. Content of ethylene: 88 mol% Content of vinyl acetate: 19.6 mol% Content of maleic acid: 0.4 mol% Melt index: 1.3 g/10 min (190°C, 2160 g) The same test as in Example 1 was performed. The Izod impact strength (with notch) was 7.8 kg·cm/cm. EXAMPLE 5 50 parts by weight of a modified ethylene-vinyl carboxylate ester copolymer specified below (1) and 50 parts by weight of an ethylene-vinyl acetate copolymer specified below (2) were blended and pelletized by using a 40-mm extruder to give a modified ethylene-vinyl carboxylate ester copolymer. (1) Modified copolymer obtained by grafting maleic anhydride onto an ethylene-vinyl acetate copolymer. Content of ethylene: 80 mol% Content of maleic anhydride: 0.8 mol% Melt index: 1.3 g/10 min (2) Ethylene-vinyl acetate copolymer. Content of ethylene: 80 mol% Melt index: 1.3 g/10 min The same EVOH as used in Example 1 and the modified ethylene-vinyl carboxylate ester copolymer prepared as mentioned above were blended at a blending ratio of 90 parts by weight to 10 parts by weight. The resulting blend was examined in the same manner as in Example 1. The Izod impact strength (with notch) was 8.0 kg·cm/cm. EXAMPLE 6 A blend was made from 90 parts by weight of the same EVOH as used in Example 1, 5 parts by weight of a modified ethylene-vinyl carboxylate ester copolymer specified below (1), and 5 parts by weight of an ethylene-vinyl acetate copolymer specified below (2). (1) Modified copolymer obtained by grafting maleic anhydride onto an ethylene-vinyl acetate copolymer. Content of ethylene: 80 mol% Content of vinyl acetate: 19.2 mol% Content of maleic acid: 0.8 mol% Melt index: 1.3 g/10 min (190°C, 2160 g) (2) Ethylene-vinyl acetate copolymer content of ethylene: 80 mol% Melt index: 1.3 g/10 min. The same test as in Example 1 was performed. The Izod impact strength (with notch) was 7.8 kg·cm/cm. EXAMPLE 7 The Izod impact strength of the test pieces prepared in Example 2 was measured at 0°C, -20°C, -40°C. and -70°C. The results are shown in Table 5. EXAMPLE 8 A blend was prepared in the same manner as in Example 2 from 90 parts by weight of the same EVOH as used in Example 1 and 10 parts by weight of the same modified ethylene-acrylate ester copolymer as used in Example 3. The blend was made into test pieces for Izod impact strength test in the same manner as in Example 2. Izod impact strength was measured at 0°C, -20°C, -40°C. and -70°C. The results are shown in Table 6. COMPARATIVE EXAMPLE 8 The Izod impact strength of the test pieces prepared in Comparative Example 4 was measured at 0°C, -20°C, -40°C. and -70°C. The results are shown in Table 7. EXAMPLE 9 The test pieces for Izod impact strength test prepared in Example 2 were immersed in a xylene solution (containing a surfactant) of DDVP (dimethyldichlorovinyl phosphate), which is an agricultural chemical, at 40°C for 30 days. The Izod impact strength measured after immersion was 8.0 kg·cm/cm. EXAMPLE 10 The test pieces for Izod impact strength test prepared in Example 8 were treated in the same manner as in Example 9. The Izod impact strength measured after immersion was 6.1 kg·cm/cm. EXAMPLE 11 Three-layered bottles (500 ml in volume) were produced by direct blow molding from three resins coextruded at 220°C from three 40-mm extruders. Each extruder was fed with the blend pellets as prepared in Example 2, a high-density polyethylene having a melt index of 0.8 g/10 min, and a maleic anhydride-modified low-density polyethylene containing 0.004 mol% of maleic anhydride and having a melt index of 1.1 g/10 min. The outer layer (high-density polyethylene) was about 800 µm thick; the interlayer (maleic anhydride-modified low-density polyethylene) was about 100 µm thick; and the inner layer (composition prepared in Example 2) was about 100 µm thick. The bottles were examined with the "dropping test" (see page 11) and for a loss of content. The results are shown in Table 8. COMPARATIVE EXAMPLE 9 Example 11 was repeated except that the inner layer was produced from the EVOH alone which was used in Comparative Example 1. The results are shown in Table 8. COMPARATIVE EXAMPLE 10 Monolayered bottles (500 ml in volume) having a wall thickness of 1 mm were produced from the same high-density polyethylene as used in Example 11. The bottles were examined with the "dropping test" and the "loss of content" test. The results are shown in Table 8. EXAMPLE 12 Three-layered bottles (10 liters in volume) were produced by direct blow molding from two resins coextruded at 220°C from three 40-mm extruders. One of the extruders was fed with the blend pellets prepared in Example 2, and each of the remaining two extruders was fed with a 50:50 mixture of the maleic anhydride-modified low-density polyethylene as used in Example 11 and a low-density polyethylene having a melt index of 0.3 g/10 min. Each of the outer layer and inner layer (mixture of maleic anhydride-modified low-density polyethylene) was about 200 µm thick, and the interlayer (composition prepared in Example 2) was about 50 µm thick. The bottles were examined with the "drop bursting test" and for their oxygen permeability. The results are shown in Table 9. COMPARATIVE EXAMPLE 11 Example 12 was repeated except that the inner layer was produced from the EVOH alone which was used in Comparative Example 1. The results are shown in Table 9. COMPARATIVE EXAMPLE 12 Monolayered bottles (10 litres in volume) having a wall thickness of 450 µm were produced from the same low-density polyethylene as used in Example 12. The bottles were examined with the "drop bursting test" and for their oxygen permeability. The results are shown in Table 9.

Claims: Resinous compositions which comprise (A) 95 to 50 parts by weight of a saponified product of an ethylene-vinyl acetate copolymer containing 20 to 60 mol% of ethylene and having a degree of saponification greater than 95% and (B) 5 to 50 parts by weight of a modified ethylene-vinyl carboxylate ester copolymer or a modified ethylene-acrylate ester copolymer comprising ethylene, a vinyl carboxylate ester or an acrylate ester, both modified with an C₃-C₁₀ α,β-unsaturated carboxylic acid or acid anhydride, wherein said modified ethylene-vinyl carboxylate ester copolymer or modified ethylene-acrylate ester copolymer contains 60 to 95 mol% of ethylene and X mol% of an α,β-unsaturated carboxylic acid or acid anhydride and has a melt index of Y g/10 min (190°C, 2160 g), where X and Y are those values that satisfy the following equations [I] and [II]. 0.01 < X < 3 [I] 0.01·Z < Y < 100 (Z + 10·X) [II] where Z is the melt index (Z g/10 min (190°C, 2160 g)) of the saponified product of the ethylene-vinyl acetate copolymer. Resinous compositions as claimed in Claim 1, wherein the vinyl carboxylate ester component is represented by the formula (where R is a linear or branched alkyl group having 1 to 20 carbon atoms.) resinous compositions as claimed in Claim 1, wherein the acrylate ester component is represented by the formula (where R' is a linear or branched alkyl group having 1 to 20 carbon atoms.) A molded article having improved impact resistance produced by melt-molding a resinous composition according to any of Claims 1, 2 and 3. A molded article as claimed in Claim 4, which is produced by coextrusion with a thermoplastic resin. A molded article as claimed in Claim 5, wherein said thermoplastic resin is selected from polyethylene terephthalate, polyamide, polypropylene, polyethylene, polycarbonate, polystyrene, and polyvinyl chloride. An impact resistant container of laminated structure formed by coextrusion of a resinous composition according to any of Claims 1, 2 and 3 and a thermoplastic resin. A container as claimed in Claim 7, wherein the inner layer is made of a resinous composition of Claim 1 and the outer layer is made of a thermoplastic resin. A container as claimed in Claim 7, wherein the interlayer is made of a resinous composition of Claim 1 and the inner and outer layers are made of a thermoplastic resin. A container as claimed in Claim 7, wherein said thermoplastic resin is selected from polyethylene terephthalate, polyamide, polypropylene, polyethylene, polycarbonate, polystyrene, and polyvinyl chloride. Use of the resinous compositions according to any of Claims 1, 2 and 3 for the preparation of impact resistant molded articles.

Inventors: IKARI, KYOICHIRO, KAWASAKI, AKIHIKO, NEGI, TAICHI
Applicants: KURARAY CO., LTD.
Application year: 1985
Main classification: C08L23
IPC codes: C08L33, B32B27, C08L23, C08L51, C08L29, C08L31, C08L101