JPH06212038A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition, comprising a thermoplastic resin such as a polyamide-based resin, a specific saponified ethylene-vinyl acetate copolymer and a specified salt of a fatty acid in a prescribed amount, excellent in compatibility, appearance and gas shielding properties and useful as a film, a sheet, etc. CONSTITUTION:This resin composition comprises (A) one or more thermoplastic resins selected from the group consisting of polyamide-based, polyester-based, PS-based, PVC-based, acrylic, polyvinylidene chloride-based, polyurethane-based, polyvinyl acetate-based, polyacetal-based and polycarbonate-based resins, (B) a saponified ethylene-vinyl acetate copolymer having 20-50mol% ethylene unit and >=96% saponification degree of the vinyl acetate unit and (C) one or more salts of metals selected from groups I, II and III of the periodic table with fatty acids in an amount of 0.00001-10 pts.wt. based on 100 pts.wt. total amount of the components (A) and (B). Furthermore, the blending ratio of the components (A) and (B) is within the range of (70/30) to (99.7/0.3).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition having a remarkably improved compatibility between a thermoplastic resin such as a polyamide resin and a saponified ethylene-vinyl acetate copolymer.

[0002]

2. Description of the Related Art Saponified ethylene-vinyl acetate copolymer (hereinafter sometimes abbreviated as EVOH) and other thermoplastic resins (excluding polyolefin, but thermoplastic resins excluding polyolefin are simply It may be called a plastic resin.) The blend composition has a characteristic physical property. In particular, a blend composition may be used in place of the thermoplastic resin layer or the EVOH layer during multi-layer coextrusion molding of various thermoplastic resins and EVOH, or a layer of the blend composition may be formed between the thermoplastic resin and the EVOH layer. It is possible to improve the interlayer adhesive force by providing the. Molded products such as films, sheets and bottles obtained by melt-extruding the blend composition alone and, if necessary, stretching and / or heat-treating have excellent gas barrier properties and mechanical properties. The characteristics of such blended compositions of various thermoplastic resins and EVOH have been known in the past, but these compositions generally have poor compatibility, and when films, sheets, bottles, etc. are formed by extrusion molding, they are non-uniform. It is known that phase-separated foreign matter is liable to be generated, and especially when operated for a long time, the foreign matter is increased and the appearance is significantly impaired. Thus, in reality, the blend composition of various thermoplastic resins and EVOH cannot be extruded practically at all, or can be operated only for a short period of time, despite its excellent characteristics.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve such poor compatibility, and an object thereof is to obtain a molded article having a beautiful appearance.

[0004]

The above object is to provide a thermoplastic resin (A) and EVOH (B) with a fatty acid salt (C) of at least one metal selected from Group I, Group II and Group III of the periodic table. Is achieved by containing an appropriate amount of.
When molded using this composition, a thermoplastic resin and E
The VOH compatibility is remarkably improved, and a coextruded product having a beautiful appearance and a high interlayer adhesive force, or a molded product having excellent gas barrier properties and mechanical properties can be obtained.

The thermoplastic resin (A) referred to in the present invention means polyamide resin, polyester resin, polystyrene resin, polyvinyl chloride resin, acrylic resin, polyvinylidene chloride resin, polyurethane resin, polyacetic acid. At least one thermoplastic resin selected from the group consisting of vinyl-based resins, polyacetal-based resins and polycarbonate-based resins, of which polyamide-based resins and polyester-based resins are particularly important for the present invention in terms of their effects and practical performance. Then, polyvinyl chloride resin and polystyrene resin are also important.

Polyamide-based resins include polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7) and poly-ω-aminononanoic acid (nylon-).
9), polyundecane amide (nylon-11), polylaurinlactam (nylon-12), polyethylenediamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethylene adiba Mido (nylon-6,6), polyhexamethylene sebacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), poly Decamethylene adipamide (nylon-10,6), polydodecamethylene sebacamide (nylon-10,8), or caprolactam / laurinlactam copolymer, caprolactam / hexamethylene diammonium adipate copolymer, laurinlactam / Hexamethylene diammonium adipate Polymer, hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer, ethylene diammonium adipate / hexamethylene diammonium adipate copolymer, caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer ,
And so on. Among them, the caprolactam / hexamethylene diammonium adipate copolymer (nylon-6 / 66) has a particularly excellent physical property in the blend with EVOH and is particularly important for practical use.

Representative examples of the polyester resin include poly (ethylene terephthalate), poly (butylene terephthalate), poly (ethylene terephthalate / isophthalate), poly (ethylene glycol / cyclohexanedimethanol / terephthalate), and the like. As a copolymerization component of these polymers, diols such as ethylene glycol, butylene glycol, cyclohexanedimethanol, neopentyl glycol and pentanediol, or isophthalic acid, benzophenone dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenylmethane dicarboxylic acid, propylene bis ( Phenyl carboxylic acid), diphenyl oxide dicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid,
Adipic acid, pimelic acid, suberic acid, azelaic acid,
Those containing dicarboxylic acids such as sebacic acid and diethylsuccinic acid are also included.

Examples of polyvinyl chloride resins include homopolymers of vinyl chloride, and copolymers with vinyl acetate, maleic acid derivatives, higher alkyl vinyl ethers and the like.

Examples of the polystyrene resin include styrene homopolymer, polystyrene obtained by graft-copolymerizing butadiene, a mixture of styrene-butadiene rubber and a styrene-maleic anhydride copolymer.

Further, the saponified product of ethylene-vinyl acetate copolymer (EVOH) (B) referred to in the present invention is any as long as it is obtained by hydrolyzing a vinyl acetate unit in a copolymer of ethylene and vinyl acetate. However, those having poor compatibility with the thermoplastic resin have relatively few ethylene units and a high degree of saponification (hydrolysis) of vinyl acetate units. In particular, the content of ethylene units is 20-50 mol%
And the degree of saponification of vinyl acetate units is 96% or more, especially 9
If 9% or more, the gas barrier property against gases such as oxygen is at the highest level in the thermoplastic resin, and excellent containers can be obtained by using it in combination with polyolifin, so that the present invention is applied. It is especially important as a target.

Further, as the fatty acid salt (C) of at least one metal selected from Group I, Group II and Group III of the Periodic Table, which constitutes the composition of the present invention, many compounds can be mentioned. It has been found that fatty acid salts of metals of Group II of the periodic table such as magnesium, calcium and zinc act particularly effectively. Examples of the fatty acid constituting the metal (group I, group II or group III) salt of fatty acid include lower fatty acids such as acetic acid, propionic acid, butyric acid, caproic acid and caprylic acid, and higher fatty acids such as lauric acid, stearic acid and myristic acid. Is mentioned. Among these, metal salts of higher fatty acids having 8 to 22 carbon atoms, especially calcium salts,
Magnesium salts and zinc salts are particularly suitable for the purpose of the present invention. These (C) components are used alone or in admixture of two or more.

(A), (B) constituting the composition of the present invention
The amount of each component of (C) and (C) is not particularly limited and can be arbitrarily selected according to the purpose. However, from a practical point of view, as the composition ratio of the thermoplastic resin (A) and EVOH (B), a composition having a large amount of either one of the resins exhibits mechanical properties or characteristic properties such as gas barrier property. It is especially important in terms of As a composition containing a large amount of thermoplastic resin, the weight ratio of thermoplastic resin (A): EVOH (B) is 60: 40-9.
9.9: 0.1, especially 70:30 to 99.7: 0.
In the case of a composition containing a large amount of EVOH, the weight ratio of thermoplastic resin (A) to EVOH (B) is 1:99 to 40:60, and particularly 5:95 to 3
It can be said that the range of 0:70 is particularly important in terms of the effect of the present invention. Further, the amount of the fatty acid salt (C) added to improve the compatibility has the effect of improving the compatibility depending on the types of the components (A), (B) and (C), and the mechanical properties of the composition, It is adjusted within a range that does not impair various physical properties such as transparency and gas barrier property, but in most cases, the amount is the sum of the weights of the thermoplastic resin (A) and EVOH (B) (A + B) 1.
0.00001 to 10 parts, especially 0.
Used in the range of 0001 to 1 part. When it exceeds 10 parts, physical properties other than compatibility are liable to be impaired, and this is not preferable in many cases. Further, when the component (C) is blended in advance with the thermoplastic resin and / or EVOH, the use effect tends to be high. As an example of blending with EVOH, 0.002 to 0.5 of the (C) component is added to 100 parts of EVOH.
Partly mixed. The effect of improving the compatibility in melt molding of a composition obtained by adding 0.5 parts of this compound and 99.5 parts of a thermoplastic resin is remarkable. In this case, the amount of the component (C) is 0.00001 to 0.0025 part with respect to 100 parts by weight of the thermoplastic resin and EVOH. (C)
When the amount of the component is less than 0.00001 part, the effect is generally small. Thus, it can be said that when the component (C) is blended with EVOH, the effect is great even when the addition amount is apparently small.

The blending method for obtaining the composition of the present invention is not particularly limited, and a method of dry blending the three is
Alternatively, the component (C) is preliminarily blended with all or part of the thermoplastic resin or EVOH, and then it is blended with the thermoplastic resin and / or EVOH, and the components (A), (B) and (C) are added. The method for obtaining the composition is arbitrarily selected according to the purpose. Generally, in addition to the method of blending with EVOH as described above, a method of dry blending or a method of blending with a thermoplastic resin in advance can be combined to obtain a particularly remarkable effect of improving compatibility. .

In the present invention, the mechanism by which the fatty acid salt (C) of a metal of group I, group II or group III of the periodic table significantly improves the compatibility of the thermoplastic resin and EVOH in melt molding is sufficiently clear. Not a thermoplastic resin and E
In the state where the rheological effect in the molten system of VOH and the chemical action of impurities are complicatedly combined (C)
It is presumed that the components are working effectively.

Other conventional additives may be added to the thermoplastic resin for the composition of the present invention. Examples of such additives include antioxidants, ultraviolet absorbers, plasticizers, antistatic agents, lubricants, colorants, fillers, and other polymer compounds, which are used in the present invention. It is possible to blend within a range in which the action and effect are not impaired. The following are specific examples of the additive.

Antioxidants: 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-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, 4,4'-thiobis- (6-t-butylphenol) and the like. UV absorber: Ethyl-2-cyano-3,3
-Diphenyl acrylate, 2- (2'-hydroxy-
5'-methylphenyl) benzotriazole, 2- (2
'Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotrial, 2-hydroxy-
4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-
Octoxybenzophenone etc. Plasticizer: dimethyl phthalate, dimethyl phthalate, dioctyl phthalate, wax, liquid paraffin, phosphate ester, etc. Antistatic agent:
Pentaerythritol monostearate, sorbitan monopalmitate, sulfated oleic acid, polyethylene oxide, carbowax, etc. Lubricants: ethylene bis stearamide, butyl stearate, etc. Coloring agents: carbon black, phthalocyanine, quinacridone, indoline, azo pigments, titanium oxide, red iron oxide, etc. Filler: Glass fiber, asbestos, mica, ballastonite, calcium silicate, aluminum silicate, calcium carbonate, etc.

Examples of means for blending the respective components for obtaining the composition of the present invention include a ribbon blender, a high speed mixer co-kneader, a mixing roll, an extruder and an intensive mixer.

The resin composition of the present invention is a well-known melt extrusion molding machine, compression molding machine, transfer molding machine, injection molding machine,
A blow molding machine, a thermoforming machine, a rotary molding machine, a dip molding machine or the like can be used to mold any desired molded article such as a film, a sheet, a tube or a bottle. The extrusion temperature at the time of molding is appropriately selected depending on the type of resin, the molecular weight, the compounding ratio of the composition, the properties of the extruder and the like, but in most cases, it is in the range of 170 to 350 ° C.

As described above, the resin composition of the present invention exerts unique characteristics in terms of adhesiveness when it is used as one layer of a multi-layer material. However, the thermoplastic resin layer is used as a P or EVOH layer. Is E, the adhesive resin layer is D, and the layer of the composition of the present invention is F, E / F / E, F / E / F, F / F
/ F (F in the intermediate layer has a high content of EVOH), F / D /
E, F / D / E / D / F, P / E / P / F, P / F / D
When a layered structure such as / E / D / F / P or P / F / D / E / D / P is used, a beautiful molded product having high interlayer adhesion and excellent compatibility can be obtained. In such a multilayer molding material, the blend composition of the present invention can be substituted by scrap of the multilayer molding material.

As a multilayer molding method, generally, the number of extruders corresponding to the type of resin layer is used, and the coextrusion molding is carried out in a layered state in which the flows of the resin melted in the extruder are superposed. It is carried out by so-called coextrusion molding. As another method, a multilayer molding method such as extrusion coating or dry lamination can be adopted.
Further, a single molded product of the composition of the present invention, or a multilayer molded product containing the composition of the present invention is subjected to stretching such as uniaxial stretching, biaxial stretching or blow stretching,
It is possible to obtain a molded product having physical properties having further characteristics such as mechanical properties and gas barrier properties. Thus, the molded product obtained from the composition of the present invention has many excellent properties such as strength physical properties and gas barrier properties because not only the blend composition is uniform and the appearance is beautiful, but also the compatibility is good and uniform. It has the following features and its industrial significance is great. Hereinafter, the present invention will be described more specifically by way of examples. The parts mean parts by weight.

[0021]

【Example】

Example 1 6/66 copolymerized polyamide (66 components 15%, melting point 19)
8 ° C.) 10 parts, EVOH [ethylene unit content 33 mol%, saponification degree 99.9%, melt index (190
90 ° C., 2160 g) 1.5 g / 10 min], and 0.03 part of magnesium stearate are dry-blended, and then have a full flight type screw having a diameter of 40 mm, L / D = 24, and a compression ratio of 3.8. It was charged in an extruder and a film was formed using a flat die having a width of 550 mm.
The film forming temperature is 190 ° to 240 ° C. for the extruder and 225 for the die.
The film having a temperature of 100 ° C. and a thickness of 100 μ was wound by a take-up machine and continuously operated for 6 hours. The obtained film was uniform and showed good compatibility, and a few phase-separated foreign matters with poor compatibility were observed. A 90 mm square test piece of the obtained film was heated at 85 ° C. for 1 minute by using a biaxial stretching tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and then tripled in length and width at a stretching speed of 5 m / min. It was stretched. Stretching was carried out uniformly, and when this stretched film was fixed to a wooden frame and heat-treated at 110 ° C. in a hot air dryer, a good film having excellent strength and gas barrier properties was obtained.

Comparative Example 1 A film of a mixture of polyamide and EVOH was formed in the same manner as in Example 1 except that magnesium stearate was not mixed. Around 30 minutes after the start of operation, a large number of non-uniform phase-separated foreign matters which were not found in Example 1 were observed, the number increased with the passage of time, and the appearance of the obtained film was extremely poor.

Examples 2 to 4 6/66 copolymerized polyamide (PA) shown in Example 1,
EVOH and various (C) components were dry-blended in the ratios shown in Table 1, and then extrusion film formation was carried out in the same manner as in Example 1. The evaluation of the film surface state of the obtained film is also shown in Table 1.

[0024]

[Table 1]

Note 1) The film surface condition was evaluated according to the following criteria. Excellent: Uniform and good compatibility with no phase-separated foreign matter. Excellent: A uniform and good compatibility is shown, but a small amount of phase-separated foreign matter is slightly observed in molding for a long time. Good: The compatibility is good, but a slight amount of phase-separated foreign matter is observed. Acceptable: The effect of improving compatibility is observed, but a slight amount of phase-separated foreign matter is observed.

Example 5 10 parts of polyethylene terephthalate (PET), 90 parts of the EVOH resin used in Example 1 and 0.03 part of magnesium stearate were dry blended, and then the diameter was 40 mm, L / D = 24, compression ratio. It was charged in an extruder having a full flight type screw of 3.8, and film formation was carried out using a flat die having a width of 550 mm. The film forming temperature was set to 200 to 275 ° C. for the extruder, 265 ° C. for the die, a film having a thickness of 100 μ was wound up by a take-up machine, and continuously operated for 6 hours. The obtained film was uniform and showed good compatibility, and a few phase-separated foreign matters with poor compatibility were observed. A 90 mm square test piece of the obtained film was used at 85 ° C. using a biaxial stretching tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.).
After heating for 1 minute, the film was stretched 3 times in both length and width at a stretching speed of 5 m / min. Stretching was carried out uniformly, and when this stretched film was fixed to a wooden frame and heat-treated at 160 ° C. in a hot air dryer, a good film having excellent strength and gas barrier properties was obtained.

Comparative Example 2 A film of a mixture of PET and EVOH was formed in the same manner as in Example 5 except that magnesium stearate was not mixed. Immediately after the start of the operation, a large number of non-uniform phase-separated foreign matters which were not found in Example 5 were observed, the number increased with the passage of time, and the appearance of the obtained film was extremely poor.

Examples 6 to 8 After PET and EVOH shown in Example 5 and various (C) components were dry-blended in the proportions shown in Table 2, Example 5 was obtained.
Extrusion film formation was carried out in the same manner as in. The evaluation of the film surface state of the obtained film is also shown in Table 2.

[0029]

[Table 2]

Example 9 Impact-resistant polystyrene resin (melt flow index 2.2 g / 10 min) (A), ethylene unit content 32.5 mol%, saponification degree 99.9 mol%, melt index 1.4 g / 96 min of EVOH (B), calcium stearate (C), and modified ethylene-vinyl acetate copolymer-based adhesive resin (D) 96: 3: 1: 0.
A blended product (F) having a ratio of 2 was prepared. The blended product (F), the above EVOH (B) and the adhesive resin (D) were charged into separate extruders, and F / D / B / D / F
Coextrusion molding of 5 layers of 3 types having a structure of (thickness ratio 15: 1: 2: 1: 15) was carried out to obtain a sheet. For extrusion molding, B and D had a diameter of 50 mm and an extruder equipped with a single screw L / D = 25 was used at a temperature of 180 to 215 ° C.
Is a co-rotating intermeshing twin-screw extruder equipped with two screws with a diameter of 100 mm and L / D = 22 of 150 to 220.
Feed block die (width 1000m
m) was set to 225 ° C., and a sheet having a thickness of 1000 μ was obtained. A good sheet was obtained even after continuous operation for 24 hours, and no phase-separated foreign matter with poor compatibility was observed.

Comparative Example 3 A sheet was obtained by carrying out coextrusion molding in the same manner as in Example 9 except that calcium stearate (C) was not used. Around 1 hour after the start of operation, non-uniform phase-separated foreign matter that was not seen in Example 9 was observed, and the number increased with the lapse of time.

Examples 10 to 13 Polystyrene resin (PS) and EVO shown in Example 9
H, the adhesive resin (AD) and various components (C) are dry blended in the proportions shown in Table 3, and the blended product (F) and the above EVOH (B) and the adhesive resin (D) are separately extruded. Co-extrusion molding was carried out in the same manner as in Example 9 after charging into the machine. The evaluation of the film surface state of the obtained sheet is also shown in Table 3.

[0033]

[Table 3]

Examples 14 to 17 Polyvinyl chloride (PVC) (A) having an average degree of polymerization of 1300
EVOH (B) and (C) having an ethylene content of 44 mol%, a saponification degree of 99 mol% and a melt index of 5 g / 10 min may be blended with 38 parts of dioctyl phthalate at a ratio shown in Table 4. Mix and use 28-inch inverted L-type calender roll to a thickness of 1 at 215 ° C.
It was formed into a film of 00μ. The obtained film had a good appearance and no phase-separated foreign matter with poor compatibility was observed. Table 4 shows the evaluation of the film surface state of the obtained film.

Comparative Example 4 A polyvinyl chloride / EVOH blend film was formed in the same manner as in Example 14 except that the component (C) was not used. On the film surface of the obtained film, inhomogeneous phase-separated foreign matter not found in Example 14 was observed, and the appearance of the film was poor.

[0036]

[Table 4]

[0037]

The compatibility between the thermoplastic resin and EVOH is remarkably improved, and the resulting molded article has a beautiful appearance.
It also has excellent gas barrier properties.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location C08L 27/06 LET 9166-4J 29/04 67/00 LPA 8933-4J LPB 8933-4J 77/00 LQS 9286- 4J 101/00 LSZ 7242-4J // B32B 27/28 102 8413-4F

Claims (5)

[Claims] 1. (A) Polyamide resin, polyester resin, polystyrene resin, polyvinyl chloride resin, acrylic resin, polyvinylidene chloride resin, polyurethane resin, polyvinyl acetate resin, polyacetal resin, and At least one thermoplastic resin selected from the group consisting of polycarbonate resins; (B) an ethylene-vinyl acetate copolymer saponified product having 20 to 50 mol% of ethylene units and a saponification degree of 96% or more of vinyl acetate units; ) It consists of a fatty acid salt of at least one metal selected from Group I, Group II and Group III of the periodic table, and the component (C) is 0 relative to 100 parts by weight of the resins (A) and (B). A resin composition containing 0.0001 to 10 parts. 2. The resin composition according to claim 1, wherein the thermoplastic resin (A) is a polyamide resin. 3. The resin composition according to claim 1, wherein the thermoplastic resin (A) is a polyester resin. 4. The resin composition according to claim 1, wherein the thermoplastic resin (A) is a polystyrene resin. 5. The resin composition according to claim 1, which is a polyvinyl chloride resin of the thermoplastic resin (A).