JPH09111069A - Adhesive polypropylene resin composition and multilayer laminated structure - Google Patents

Abstract

(57) Abstract: Adhesive polypropylene resin composition showing excellent adhesion to polyolefin such as polypropylene and polyamide resin and / or ethylene / vinyl alcohol copolymer, and polyolefin layer and polyamide resin layer and / or Alternatively, there is provided a multilayer laminated structure having an adhesive layer made of the above adhesive polypropylene resin composition between the ethylene / vinyl alcohol copolymer layer. SOLUTION: (a) Modified polypropylene or a resin composition containing the modified polypropylene grafted with at least one monomer selected from unsaturated carboxylic acids or derivatives thereof, 50 to 90 parts by weight and (b) unsaturated carboxylic acid. Modified polyolefin other than the above (a) grafted with at least one monomer selected from acids or derivatives thereof, an adhesive polypropylene resin composition comprising 10 to 50 parts by weight, a polyolefin layer, and the above adhesive polypropylene resin composition. A multi-layer laminated structure of three or more layers, wherein an adhesive layer consisting of, a layer of polyamide resin and / or a layer of ethylene-vinyl alcohol copolymer are laminated in this order.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adhesive polypropylene resin composition and a multilayer laminated structure. More specifically, an adhesive polypropylene resin composition suitable for adhering a polyolefin layer such as a polypropylene layer and a layer of a polyamide resin and / or an ethylene / vinyl alcohol copolymer, and a multilayer laminated structure using the same as an adhesive layer Regarding

[0002]

2. Description of the Related Art Conventionally, a laminated film of a polyolefin such as polypropylene and a polyamide resin and a laminated film of a polyolefin such as polypropylene and an ethylene / vinyl alcohol copolymer are known, and various materials for an adhesive layer therefor are known. Proposed. However, these materials do not always show a sufficiently satisfactory adhesive strength because the adhesive strength is greatly reduced in the stretching process in manufacturing the shrink film.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an adhesive polypropylene resin composition which exhibits excellent adhesion to a polyolefin such as polypropylene and a polyamide resin and / or an ethylene / vinyl alcohol copolymer. It is in. Another object of the present invention is a multilayer laminated structure having an adhesive layer comprising the above adhesive polypropylene resin composition of the present invention between a polyolefin layer and a polyamide resin layer and / or an ethylene / vinyl alcohol copolymer layer. To provide.

Still another object of the present invention is to provide a multi-layer laminated structure having an adhesive layer made of the above adhesive polypropylene resin composition of the present invention, which exhibits excellent adhesive force in both unstretched and stretched state. Especially.

[0005]

According to the present invention, (a)
Modified polypropylene or resin composition containing the modified polypropylene grafted with at least one monomer selected from unsaturated carboxylic acids or derivatives thereof, 50-
Modified polyolefin other than the above (a) grafted with 90 parts by weight and (b) at least one monomer selected from unsaturated carboxylic acids or derivatives thereof, 10 to 50
An adhesive polypropylene resin composition comprising parts by weight is provided. Further, according to the present invention, a three-layer structure comprising a polyolefin layer, an adhesive layer comprising the adhesive polypropylene resin composition and a layer of a polyamide resin and / or an ethylene / vinyl alcohol copolymer are laminated in this order. The above multilayer laminated structure is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the adhesive polypropylene resin composition of the present invention, the polypropylene as the raw material resin for the modified polypropylene of the component (a) has a melting point of 13
A propylene homopolymer having a temperature of more than 0 ° C. and 170 ° C. or less or a copolymer of propylene having a propylene content of 93 mol% or more and another α-olefin is preferably used. When a copolymer is used, other α-
Examples of the olefin include ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene. The melt flow rate of polypropylene or copolymer (value measured at 230 ° C. according to ASTM D1238) is preferably 0.1 to 1.
00, more preferably 0.5 to 50 g / 10 minutes.

An unsaturated carboxylic acid or a derivative thereof is used as the grafting monomer (hereinafter referred to as "graft monomer"), and specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, Examples include fumaric acid and itaconic acid. Examples of the derivative of the unsaturated carboxylic acid include acid anhydrides, esters, amides, imides, and metal salts. Specifically, maleic anhydride, hymic acid anhydride (5-norbornene-2,3-dicarboxylic acid anhydride), itaconic anhydride, citraconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, acrylic acid Glycidyl, maleic acid monoethyl ester, maleic acid diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, itaconic acid monomethyl ester, itaconic acid diethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide,
Maleic acid-N-monoethylamide, maleic acid-N,
N-diethylamide, maleic acid-N-monobutylamide, maleic acid-N, N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monobutylamide, fumaric acid-N, N-dibutylamide, Maleimide, N-butyl maleimide, N-phenyl maleimide, sodium acrylate, sodium methacrylate,
Examples thereof include potassium acrylate and potassium methacrylate. Of these grafting monomers, it is most preferable to use maleic anhydride or hymic acid anhydride.

The polypropylene modified with an unsaturated carboxylic acid or a derivative thereof is preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight of the unsaturated carboxylic acid or polypropylene based on the polypropylene before modification. The derivative is graft-modified. The component (a) of the present invention may be composed only of graft-modified polypropylene, or may be a composition of unmodified polypropylene and graft-modified polypropylene.

As the modified polyrefin of (b), polyethylene, polybutene, ethylene / α-olefin copolymer (however, excluding ethylene / propylene copolymer having an ethylene content of 7 mol% or less) is used as a base resin and is unsaturated. Graft-modified with carboxylic acid or its derivative, and preferably (i) has a density of 0.860 to 0.9.
30 g / cm ³ , more preferably 0.860-0.90
5 g / cm ³ , (ii) melt flow rate (MFR) at 190 ° C. and 2.16 kg load is 0.1 to 50 g /
10 minutes, more preferably 0.1 to 10 g / 10 minutes, and (iii) modified polyethylene or modified ethylene.α- with a graft ratio of 0.01 to 5% by weight, more preferably 0.3 to 3% by weight. It is an olefin copolymer. More preferred is a modified polyolefin having a substantially amorphous or low crystalline ethylene / α-olefin copolymer as a base resin.

The base resin before modification of the graft-modified ethylene / α-olefin copolymer (b) is more preferably a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. Among these, the α-olefin is preferably an α-olefin having 3 to 10 carbon atoms. α
Preferred examples of the olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene. The ethylene / α-olefin copolymer (b) before modification is a titanium (Ti) -based, vanadium (V) -based,
It can be produced by a conventionally known method using a catalyst such as zirconium (Zr).

The ethylene / α-olefin copolymer (b) preferably contains ethylene-derived polymerized units in an amount of 95 to 70 mol%, more preferably 90 to 75 mol%. Further, the ethylene / α-olefin copolymer (b) is substantially amorphous or low crystalline, and preferably has a crystallinity (measured by an X-ray diffraction method) of less than 40%.

Various known methods can be employed to produce a modified product by graft-copolymerizing a graft monomer with a polyolefin. For example, there is a melt modification method in which a polyolefin is melted using an extruder and a graft monomer is added to perform graft copolymerization, or a solution modification method in which a polyolefin is dissolved and a graft monomer is added to perform graft copolymerization. In either case, it is preferable to initiate the reaction in the presence of a radical initiator in order to efficiently graft-copolymerize the graft monomer. The graft reaction is usually performed at a temperature of 60 to 350 ° C. The proportion of the radical initiator used is usually in the range of 0.001 to 1 part by weight based on 100 parts by weight of the polyolefin. Radical initiators include organic peroxides, organic peresters such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxide benzoate) hexyne- 3,1,4-bis (tert-butylperoxyisopropyl) benzene, lauroyl peroxide, tert-butyl peracetate,
2,5-Dimethyl-2,5-di (tert-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (te
rt-butylperoxy) hexane, tert-butylperbenzoate, tert-butylperphenylacetate, te
rt-butyl perisobutyrate, tert-butyl per-se
c-Octoate, tert-butyl perpivalate, cumyl perpivalate and tert-butyl perdiethyl acetate, and other azo compounds such as azoisobutyronitrile and dimethylazoisobutyrate are used. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoate) hexyne-3,2,5-dimethyl-
2,5-di (tert-butylperoxy) hexane, 1,
Dialkyl peroxides such as 4-bis (tert-butylperoxyisopropyl) benzene are preferred. During the reaction, other monomers such as styrene may coexist.

The grafting amount of the grafting monomer onto the polyolefin (hereinafter referred to as "grafting rate") is preferably adjusted so that the grafting rate of the entire composition is in the range of 10 ^{-4 to} 5% by weight. From the viewpoint of industrial production, a method in which a modified polyolefin having a graft ratio of 10 ^{-2 to} 6% by weight is manufactured in advance, and then the modified polyolefin is mixed with an unmodified polyolefin to adjust the graft ratio is
This is a preferable method because the amount of the grafting monomer in the composition can be adjusted appropriately, but a predetermined amount of the grafting monomer may be added to the polyolefin from the beginning.

In the case of polyethylene or an ethylene / α-olefin copolymer, the melt modification method and the solution modification method can be adopted, but in the case of polypropylene, the solution modification method is preferable from the viewpoint of graft reaction efficiency and suppression of molecular weight reduction. .

The above components (a) and (b) contain 5 parts of the component (a) based on 100 parts by weight of these components in total.
0 to 90 parts by weight, preferably 50 to 80 parts by weight, and 10 to 50 parts by weight of component (b), preferably 20 to 5 parts by weight.
It is contained in 0 parts by weight. The composition of the present invention containing the components (a) and (b) has a melt flow rate (ASTM) of
D1238, 230 ° C.) is preferably 0.5 to 30 g / 10 minutes, more preferably 1 to 10 g / 10 minutes.

The above-mentioned adhesive polypropylene resin composition of the present invention exhibits excellent adhesion to polyolefin resins such as polypropylene resin, polyamide resins and ethylene / vinyl alcohol copolymers. Therefore, according to the present invention, secondly, a multilayer structure in which a polyolefin layer such as polypropylene, an adhesive layer and a layer of a polyamide resin and / or an ethylene / vinyl alcohol copolymer are laminated in this order, There is also provided a multilayer laminated structure in which the adhesive layer comprises the adhesive polypropylene resin composition of the present invention.

The multi-layer laminate structure of the present invention comprises at least 3 layers.
The first layer is a polyolefin layer (A), the second layer is an adhesive layer (B), and the third layer is a layer made of a polyamide resin and / or an ethylene / vinyl alcohol copolymer (C). For example, A / B / C, A / B / C / B, A /
It is a combination of B / C / B / A and the like.

A typical example of the first polyolefin layer is a polypropylene resin layer. The polypropylene resin constituting the layer is a propylene homopolymer or propylene having a propylene content of 93 mol% or more. And other α-olefins. Other α-olefins include, for example, ethylene,
1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene and the like can be mentioned.

The second adhesive layer of the multilayer laminated structure of the present invention comprises the above-mentioned adhesive polypropylene resin composition of the present invention.

The third layer of the multilayer laminated structure of the present invention comprises a polyamide resin layer and / or an ethylene / vinyl alcohol copolymer. As the polyamide resin, for example, nylon 6, nylon 66, nylon 610, nylon 1
2, Nylon 11, MXD nylon, amorphous nylon, terephthalic acid / adipic acid / hexamethylenediamine copolymer and the like can be preferably used. Also,
The ethylene / vinyl alcohol copolymer is preferably 2
It has an ethylene content of 0 to 50 mol%. ethylene·
The vinyl alcohol copolymer can be prepared by saponifying ethylene and vinyl acetate copolymer.

The multilayer laminated structure of the present invention can be produced by laminating a polypropylene layer, an adhesive layer and a layer of polyamide resin and / or ethylene / vinyl alcohol copolymer in a molten state. The multilayer laminated structure can be produced by, for example, coextrusion molding, cast film molding, blown film molding and tenter method or tubular method biaxial stretching. Usually, the stretching conditions for producing the shrink film include a stretching temperature of 70 to 130 ° C. and a stretching ratio (longitudinal x
The width) is 2 × 2 to 5 × 5 times, and the obtained film thickness is 10 to 200 μm.

The multilayer laminated structure of the present invention can be used in an unstretched state as it is after molding, or can be stretched in at least uniaxial direction, preferably biaxial direction after molding. When the third layer is a polyamide resin layer, it is preferably stretched before use.
When the layer is a vinyl alcohol copolymer, it can be used in either unstretched or stretched state. Since high strength can be obtained by stretching, it is preferable to stretch before use when high strength is required. However, by stretching, the adhesive strength of the adhesive layer is generally slightly reduced. Even if the multilayer laminated structure of the present invention is stretched,
Adhesive strength is not significantly reduced and sufficient practical adhesive strength is maintained. Stretching is preferably carried out in a uniaxial direction at a stretch ratio of 1.5 to 6 times. In the biaxial stretching, it is preferable to stretch in the biaxial directions at a stretching ratio of 1.5 to 6 times.

When the multilayer laminated structure of the present invention is cast by the T-die method, the molding speed is, for example, 20 m.
By molding at a relatively high speed of not less than / min, preferably 20 to 150 m / min, it is possible to obtain a multi-layer laminated structure exhibiting film strength and adhesive force having the same tendency as the above-mentioned stretched product. INDUSTRIAL APPLICABILITY The multilayer laminated structure of the present invention is excellent in strength, heat resistance, gas barrier properties, and can impart shrinkability, and thus can be suitably used for packaging meat such as ham.

[0024]

The present invention will be described in more detail with reference to the following examples. The present invention is in no way limited by these examples. Incidentally, in the present invention, including the following examples, the graft-modified polypropylene (a), "graft ratio" of a graft-modified polyolefin (b), by infrared spectroscopic measurement device, 1792Cm ^-1 or 1860 cm ^-1
And the absorbance at 4335 cm ⁻¹ were measured, and (17
Absorbance measurements of 92cm ^-1 or 1860 cm ^-1) /
(Absorbance measurement value at 4335 cm ⁻¹ ) was obtained, and the graft ratio was obtained from the value of this ratio using a calibration curve chart prepared in advance.

Example 1 Propylene / ethylene random copolymer (r-PP; ethylene content: 3.6 mol%, melting point: 139 ° C., MFR (230 ° C.) = 6 g / 10
Min) 85 parts by weight and maleic anhydride graft-modified polypropylene (MAH-PP; maleic anhydride graft amount: 3)
% By weight, 5 parts by weight of intrinsic viscosity [η] in decalin solvent at 135 ° C. = 0.4 dl / g, melting point of 160 ° C. and maleic anhydride graft-modified ethylene / butene copolymer (MAH-EBR; manufactured by V-type catalyst) , Butene content: 1
0 mol%, maleic anhydride graft amount: 0.5 wt%,
MFR (190 ° C) = 5g / 10 minutes, melting point 70 ° C) 10
After mixing parts by weight with a Henschel mixer, the mixture was melt-kneaded with a single-screw extruder (set temperature: 230 ° C., special Dalmage screw) to obtain a modified polypropylene resin composition. Then, using this composition, the adhesive strength with the ethylene / vinyl alcohol copolymer and the polyamide resin was measured by the following methods.

(I) Method for evaluating adhesive strength between ethylene / vinyl alcohol copolymer and ethylene / vinyl alcohol copolymer (EVOH; trade name Eval EP-E105, manufactured by Kuraray Co., Ltd., MFR:
5.5 g / 10 minutes, ethylene content: 44 mol%),
The modified polypropylene resin composition and the r-PP
Was used to mold a three-layer cast film under the following conditions. Film layer structure: EVOH (outer layer) / composition (middle layer) / r-PP = 40
/ 40 / 160μ (II) Adhesive strength evaluation method with polyamide resin Polyamide resin (PA; trade name Amilan, Toray Industries, Inc.)
Manufactured), the modified polypropylene resin composition and the r
A three-layer cast film was molded using -PP under the following conditions. Film layer structure: PA (outer layer) / composition (middle layer) / r-PP = 40/4
0 / 160μ

The obtained three-layer film of each of (I) and (II) above was heated at 80 ° C. using a biaxial stretching device manufactured by Toyo Seiki Co., Ltd.
After heating for 10 minutes, at that temperature 3 times in the vertical direction and 3 in the horizontal direction.
Double and simultaneous biaxial stretching was performed to prepare a three-layer stretched film. Then, after cooling to room temperature, the interfacial adhesive strength between the EVOH layer or polyamide layer of each three-layer stretched film and the composition was measured at a peeling speed of
It was determined by T-type peeling at 00 mm / min. Table 1 shows the results.

[Examples 2 and 3] The mixing ratio of the propylene / ethylene random copolymer (r-PP) blended in the modified polypropylene resin composition in Example 1 was 7 each.
5 parts by weight (Example 2) and 65 parts by weight (Example 3),
Treatment was carried out in the same manner as in Example 1 except that the amount of the maleic anhydride graft-modified ethylene / butene copolymer (MAH-EBR) was 20 parts by weight (Example 2) and 30 parts by weight (Example 3), respectively. A modified polypropylene resin composition was prepared in this manner, and the adhesive strength thereof was evaluated in the same manner as in Example 1.
Table 1 shows the results.

Example 4 MAH-E used in Example 2
Maleic anhydride graft-modified ethylene in place of BR
Propylene copolymer (MAH-EPR; manufactured with V-based catalyst, propylene content: 20 mol%, maleic anhydride graft amount: 0.5 wt%, MFR (190 ° C) = 3 g /
The same procedure as in Example 2 was performed except that 10 minutes was used and the melting point was 40 ° C.). Table 1 shows the results.

[Example 5] MAH-E used in Example 2
Maleic anhydride graft-modified ethylene in place of BR
Octene copolymer (MAH-EOR; manufactured with Zr-based catalyst, octene content: 15 mol%, maleic anhydride graft amount: 0.5 wt%, MFR (190 ° C) 3 g / 10
Min, melting point 55 ° C.) was used. Table 2 shows the results.

Example 6 Instead of r-PP used in Example 3, propylene homopolymer (h-PP; melting point: 16)
The same procedure as in Example 3 was performed except that 5 ° C. and MFR (230 ° C.) = 6 g / 10 minutes) were used. Table 2 shows the results.

[Example 7] MAH-E used in Example 3
Instead of 30 parts by weight of BR, maleic anhydride graft modified polyethylene (MAH-PE; 0.92 g / cm ³ , T
Manufactured with i-based catalyst, grafted amount of maleic anhydride: 1.0% by weight, MFR (190 ° C.) = 0.5 g / 10 minutes, melting point 1
22 ° C.) 10 parts by weight and unmodified ethylene / propylene copolymer (EPR; manufactured with V-based catalyst, propylene content: 2
0 mol%, MFR (190 ° C.) = 3 g / 10 min, melting point 4
The same procedure as in Example 3 was performed except that 20 parts by weight (0 ° C.) was used. Table 2 shows the results.

[Embodiment 8] MAH-E used in Embodiment 3
MAH-EBR1 of Example 3 in place of 30 parts by weight of BR
Example 3 was repeated except that 5 parts by weight and 15 parts by weight of EPR used in Example 7 were used. Table 2 shows the results.

[0034]

[Table 1]

[0035]

[Table 2]

Comparative Example 1 r-PP and MAH-PP used in Example 1 were used in the proportions shown in Table 3, and MAH
The same procedure as in Example 1 was carried out except that EBR was not added. Table 3 shows the results.

(Comparative Examples 2 and 3) r used in Example 1
-PP and MAH-PP in the amounts shown in Table 3 (parts by weight)
20 parts by weight of EPR (unmodified ethylene-propylene copolymer) of Example 7 were used instead of 10 parts by weight of MAH-EBR prepared in Example 1 (Comparative Example 2) and 30 parts by weight, respectively. (Comparative Example 3) Example 1 except that compounded
The same was done. Table 3 shows the results.

[0038]

[Table 3]

[0039]

According to the present invention, polyolefin resin such as polypropylene resin, polyamide resin and ethylene
It is possible to provide an adhesive resin composition that exhibits excellent adhesion to a vinyl alcohol resin and a multilayer laminated structure having the adhesive layer as an adhesive layer.

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Claims (9)

[Claims] 1. A modified polypropylene or a resin composition containing the modified polypropylene, which is grafted with at least one monomer selected from unsaturated carboxylic acids or derivatives thereof (a), 50 to 90 parts by weight, and (b) unsaturated. An adhesive polypropylene resin composition comprising 10 to 50 parts by weight of a modified polyolefin other than the above (a) grafted with at least one monomer selected from carboxylic acids or derivatives thereof. 2. The modified polyolefin (b) is
(I) density, 0.860 to 0.930 g / cm ³ , (ii)
Melt flow rate (MFR) at 190 ° C. under a load of 2.16 kg, 0.1 to 50 g / 10 minutes, (iii) graft ratio, 0.01 to 5% by weight, modified polyethylene or modified ethylene / α-olefin copolymer weight. The adhesive polypropylene resin composition according to claim 1, which is a united body. 3. A polyolefin layer, an adhesive layer comprising the adhesive polypropylene resin composition according to claim 1, and a layer of a polyamide resin and / or an ethylene / vinyl alcohol copolymer are laminated in this order. A multilayer laminated structure having three or more layers. 4. The multilayer laminated structure according to claim 3, which is stretched in at least a uniaxial direction. 5. The multilayer laminated structure according to claim 4, which is stretched in at least one axial direction at a stretch ratio of 1.5 to 6 times. 6. The multilayer laminated structure according to claim 4, which is biaxially stretched. 7. The multilayer laminated structure according to claim 6, which is stretched in each axial direction at a stretch ratio of 1.5 to 6 times. 8. The multilayer laminated structure according to claim 3, which is molded at a high speed by a tubular biaxially stretched film molding method. 9. The multilayer laminated structure according to claim 3, wherein the polyolefin layer is an ethylene / α-olefin copolymer having a melt flow rate of 0.1 to 50 g / 10 min.