JPH07103283B2 - Modified polyolefin composition for adhesion - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a modified polyolefin composition for adhesion, and more particularly to a modified polyolefin composition for adhesion which can reduce the neck-in phenomenon during extrusion lamination. .

Technical Background of the Invention and Problems Thereof In order to impart gas barrier property, water vapor barrier property and oil resistance to packaging materials, ethylene vinyl acetate copolymer saponified product (EVOH), polyamide (Ny), polyester (PET) is used. ), Polypropylene (PP), and other multi-layer films made of resin. As a method of multilayering,
Co-extrusion molding is generally used, but as a film for packaging materials, it is more excellent in barrier properties, and is a biaxially or uniaxially stretched film with elasticity, or aluminum foil (for use in which light shielding properties and high barrier properties are required. Al foil) or Al vapor deposition film may be used. These two axes or one
When an axially stretched film, an Al foil, or an Al vapor deposition film is added to a multilayer film, it is common practice to bond a preformed film or foil with a dry laminating adhesive. However, dry laminating adhesion has problems such as toxicity of residual solvent and complicated process. As a method for avoiding such problems, multilayering is performed by extrusion laminating or sand laminating, but treatment with an anchor agent or the like is required to obtain a strong adhesive force with the base film.

The applicant of the present invention discloses that (A) in Japanese Patent Application Laid-Open No. 61-241144.
It has been proposed to use, as an adhesive layer, a modified polyolefin composition for adhesion comprising a graft-modified ethylene / α-olefin random copolymer partially or wholly graft-modified and (B) a tackifier.

This modified polyolefin composition for adhesion was also found to be effective as an adhesive resin when extrusion laminating on various substrates, but when laminating various substrates by the extrusion laminating method, a film of It has been found by the present inventor that a problem that a so-called neck-in phenomenon is considerably recognized in which the width becomes narrower and the edge portion becomes thicker occurs.

OBJECT OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, and exhibits excellent adhesiveness to various substrates, and particularly, a neck-in phenomenon that occurs during extrusion lamination. It is an object of the present invention to provide a modified polyolefin composition for adhesion that can reduce

SUMMARY OF THE INVENTION The modified polyolefin composition for adhesion according to the present invention comprises (A) a graft amount: 0.01 to 10% by weight, a melt flow rate: 0.1 to 50 g / 10 minutes, a density: 0.850 to 0.900 g / cm ^{3 an} ethylene content: 30 -95 mol% X-ray crystallinity: 40% or less, Graft-modified ethylene partially or wholly graft-modified with unsaturated carboxylic acid or its derivative
α-olefin random copolymer: 98 to 50% by weight, (B) tackifier: 1 to 50% by weight, (C) melt flow rate: 0.1 to 20 g / 10 minutes, density: 0.905 to 0.940 g / cm ³ A high-pressure low-density polyethylene is characterized by being composed of 1 to 40% by weight.

The modified polyolefin composition for adhesion according to the present invention,
In addition to (A) graft-modified ethylene / α-olefin random copolymer, (B) tackifier, and (C) specific high-pressure low-density polyethylene, it is excellent for various substrates. In addition to exhibiting adhesiveness, the neck-in phenomenon that occurs particularly during extrusion lamination can be reduced.

Detailed Description of the Invention Each component constituting the modified polyolefin composition for adhesion according to the present invention will be specifically described below.

(A) Graft-modified ethylene / α-olefin random copolymer The graft-modified ethylene / α-olefin random copolymer used in the present invention has an unsaturated carboxylic acid or derivative thereof in an amount of 0.01 to 10% by weight, preferably Is 0.1
Up to 5% by weight and the melt flow rate (MFR ₂ : ASTM D1
238, E) is 0.1 to 50 g / 10 min, preferably 0.2 to 20 g / 10 min, and the density is 0.850 to 0.900 g / cm ³ , preferably 0.855 to
0.895 g / cm ³ , an ethylene content of 30 to 95 mol%, preferably 40 to 95 mol%, and a crystallinity of 40 by X-ray.
% Or less, preferably 30% or less. A partially or wholly graft-modified ethylene / α-olefin random copolymer graft-modified with an unsaturated carboxylic acid or a derivative thereof.

Grafting amount of unsaturated carboxylic acid or its derivative is 0.01
If it is less than 10% by weight, the adhesion to the substrate such as EVOH is not sufficient, while if it exceeds 10% by weight, some crosslinking occurs,
It is not preferable because the dispersibility of the (B) tackifier or (C) high-pressure low-density polyethylene decreases, and also the adhesiveness with the substrate decreases.

When the melt flow rate (MFR ₂ ) is outside the above range,
Since the melt viscosity is too high or too low, moldability and adhesive strength are inferior, which is not preferable. When the density exceeds 0.900 g / cm ³ , the adhesive strength with a substrate such as EVOH becomes poor, which is not preferable. Further, if the crystallinity by X-ray exceeds 40%, the adhesive strength with a substrate such as EVOH is deteriorated, which is not preferable.

The α-olefin constituting the graft-modified ethylene / α-olefin random copolymer of the present invention is usually an α-olefin having 3 to 20 carbon atoms, specifically, for example, propylene, 1-butene, 1-hexene, 4 -Methyl-1-pentene, 1-octene, 1-decene, 1-tetradecene,
1-octadecene, etc., which are used alone or in combination of two or more.

The graft-modified ethylene / α-olefin random copolymer of the present invention is, as described above, a low crystalline or amorphous polyolefin, and the low crystalline copolymer usually has a melting point (ASTM D 3418). It is below 100 ℃.

The ethylene / α-olefin random copolymer used as the base material of the modified random copolymer used in the present invention has a melt flow rate (MFR ₂ ) of 0.1 to 50 g / 10 minutes,
Density of 0.850~0.900g / cm ^3, ethylene content 30
A random copolymer of ethylene and α-olefin having a crystallinity of 40% or less by X-ray is used.

The ethylene / α-olefin random copolymer is
The unsaturated carboxylic acid or derivative thereof
Acrylic acid, maleic acid, fumaric acid, tetrahydrofuran
Talic acid, itaconic acid, citraconic acid, crotonic acid, iso
Crotonic acid, nadic acid (Endocis-bicyclo [2,
2,1] Hept-5-ene-2,3-dicarboxylic acid), etc.
Unsaturated carboxylic acids, or their derivatives, such as acid
Ride, amide, imide, anhydride, ester, etc.
Specifically, maleenyl chloride, maleimide, anhydrous male
Maleic acid, citraconic anhydride, monomethyl maleate,
Examples include dimethyl maleate and glycidyl maleate.
To be done. Among these, unsaturated dicarboxylic acids or
Acid anhydrides are preferred, especially maleic acid, nadic
acid Alternatively, these acid anhydrides are suitable.

In order to produce a modified product by graft-copolymerizing a graft monomer selected from the unsaturated carboxylic acid or its derivative with the ethylene / α-olefin random copolymer, various conventionally known methods may be adopted. it can. For example, there is a method in which an ethylene / α-olefin random copolymer is melted and a graft monomer is added to perform graft copolymerization, or a method in which the ethylene / α-olefin random copolymer is dissolved and dissolved in a solvent and a graft monomer is added to perform graft copolymerization. In any case, it is preferable to carry out the reaction in the presence of a radical initiator in order to efficiently graft-copolymerize the graft monomer. Grafting reaction is usually 60-350 ℃
Performed at the temperature of. The use ratio of the radical initiator is usually in the range of 0.001 to 1 part by weight with respect to 100 parts by weight of the random copolymer. 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 (tert-butylperoxy) hexane, tert-butylperbenzoate, tert-butylperphenylacetate, tert-butylperisobutyrate, tert-butylper-sec-octoate, tert-butylperpivalate, cumylperpyrate Valates and tert-butyl perdiethyl acetate, as well as other azo compounds such as azobisisobutyronitrile, dimethylazoisobutyrate. Among these, dicumyl peroxide, di-tert
-Butyl peroxide, 2,5-dimethyl-2,5-di (tert
-Butylperoxy) hexyne-3,2,5-dimethyl-
Dialkyl peroxides such as 2,5-di (tert-butylperoxy) hexane and 1,4-bis (tert-butylperoxyisopropyl) benzene are preferably used.

The graft-modified ethylene / α-olefin random copolymer used in the present invention may be partially diluted with the ethylene / α-olefin random copolymer,
In that case, the graft amount of unsaturated carboxylic acid or the like must be within the above range as a whole.

Such a graft-modified ethylene / α-olefin random copolymer has a composition of 98 to 100% in the adhesive composition according to the present invention.
It is used in an amount of 50% by weight, preferably 90-60% by weight. If the amount of the random copolymer is less than 50% by weight, the fluidity of the composition becomes too high, the moldability is lowered, and the adhesiveness is lowered, which is not preferable. On the other hand, when it exceeds 98% by weight, the adhesiveness to the substrate is deteriorated, which is not preferable.

(B) Tackifier The tackifier used in the present invention is a solid amorphous polymer, which is usually used as a tackifier resin in the fields of adhesive tapes, paints, and hot melt adhesives, and is polymerized. The following resins can be listed according to the difference in the monomer source. For example, C ₄ fraction, C ₅ fraction obtained by cracking petroleum, naphtha and the like, a mixture thereof or any fraction thereof, for example, isoprene and 1,3-pentadiene in the C ₅ fraction are main raw materials. Obtained by decomposing aliphatic hydrocarbon resin, petroleum, naphtha, etc.
Aromatic hydrocarbon resin whose main raw material is styrene derivative and indene in C ₉ fraction, and any fraction of C ₄ and C ₅ fractions
C ₉ fraction obtained by copolymerizing aliphatic aromatic copolymer hydrocarbon resins, aromatic alicyclic hydrocarbon resins hydrocarbon resins obtained by hydrogenating aliphatic, a structure containing an alicyclic pre aromatic Synthetic terpenic hydrocarbon resin, terpenic hydrocarbon resin derived from turpentine oil α, β-pinene, indene in coal tar naphtha and coumarone indene hydrocarbon resin derived from styrene, low molecular weight Examples thereof include styrene resin and rosin hydrocarbon resin.

Among these tackifiers (B), an aliphatic hydrocarbon resin obtained by hydrogenating an aliphatic hydrocarbon resin and an aromatic hydrocarbon resin has good dispersibility such as ethylene / α-olefin random copolymer. More preferably, the softening point (ring and ball method) is 70 to 150 ° C., preferably 80 to 140 ° C., and the hydrogenation rate to the aromatic nucleus is 80% or more, preferably 85% or more. Particularly preferred.

Such a tackifier is used in the adhesive composition according to the present invention in an amount of 1 to 50% by weight, preferably 5 to 40% by weight. If the amount of this tackifier is less than 1% by weight, the adhesiveness to a substrate such as polystyrene is deteriorated, which is not preferable. On the other hand, if it exceeds 50% by weight, the fluidity becomes too high and the moldability tends to decrease. Is not preferable.

(C) High Pressure Low Density Polyethylene The high pressure low density polyethylene used in the present invention has a melt flow rate MFR ₂ of 0.1 to 50 g / 10 minutes, preferably 1 to 20 g.
/ 10 minutes, the density 0.905 ~ 0.940 g / cm ³ preferably 0.91
It is 0 to 0.935 g / cm ³ . If the MFR ₂ exceeds 50 g / 10 minutes, the neck-in improvement effect tends to be small, while the MFR ₂
If it is less than 0.1 g / 10 minutes, the moldability may be deteriorated.

By including the high-pressure low-density polyethylene as described above in the modified polyolefin composition for adhesion according to the present invention, it is possible to significantly reduce the neck-in phenomenon when the composition is used during lamination. become.

Such high-pressure low-density polyethylene is used in the adhesive composition of the present invention in an amount of 1 to 40% by weight, preferably 5 to 30% by weight. The amount of this low density polyethylene is 1
If it is less than 10% by weight, the neck-in phenomenon at the time of lamination cannot be sufficiently reduced, and if it exceeds 40% by weight, the adhesion to the substrate is deteriorated, which is not preferable.

To obtain the composition of the present invention, the above-mentioned (A) ethylene.α-
An olefin random copolymer, (B) a tackifier,
(C) Modified polyethylene and (D) High-pressure low-density polyethylene are mixed within the above range by various known methods, for example, a method of mixing with a Henschel mixer, a V-blender, a ribbon blender, a tumbler blender, or after mixing, uniaxial extrusion A method of melt-kneading with a machine, a twin-screw extruder, a kneader, a Banbury mixer, etc., and then granulating or pulverizing may be adopted.

In the composition of the present invention, in addition to the above components, if necessary, a heat resistance stabilizer, a weather resistance stabilizer, an antistatic agent, a pigment, a dye, a rust inhibitor and the like within a range not impairing the object of the present invention. It may be mixed in.

As a method for obtaining a laminate using the composition of the present invention,
For example, a uniaxially or biaxially stretched film of EVOH, Ny, PET, PP or the like which has been preformed, or an Al foil, an Al vapor deposition film or the like is used as a base material and the composition of the present invention, and another One or two or more kinds of resins are melted by separate extruders, and after melting, they are separately supplied to a die having a structure of two layers or three or more layers, and the composition of the present invention is used as a base material on the base material. A method of performing co-extrusion laminating so as to come to the material side, or a so-called sandwich laminating method of melt-extruding the composition between the two layers of the preformed base material may be mentioned. The die used here is a so-called flat die, and either a single manifold type using a black box or a multi manifold type may be used.

When the modified polyolefin composition for adhesion according to the present invention is used to laminate substrates to produce a laminate, the adhesive layer preferably has a thickness of 0.005 to 1 mm.

As the base material used in the present invention, any polymer having a film forming ability or paper, aluminum foil, cellophane, etc. can be used.

Examples of such a polymer include high density polyethylene, medium and low density polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid ester copolymer, ionomer, polypropylene, poly-1-butene, poly-4. -Olefin polymers such as methyl-1-pentene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate, vinyl polymers such as polyacrylonitrile, nylon 6, nylon 66, nylon 7,
Nylon 10, Nylon 1, Nylon 12, Nylon 610,
Examples thereof include polyamides such as polymethaxylylene adipamide, polyesters such as polyethylene terephthalate, polyethylene terephthalate / isophthalate and polybutylene terephthalate, polyvinyl alcohol, ethylene, vinyl alcohol copolymers and polycarbonates. These base materials can be appropriately selected depending on the purpose and the article to be packaged. For example, when the food to be packaged is easily corroded, a resin excellent in transparency, rigidity and gas permeation resistance such as polyamide, polyvinylidene chloride, ethylene / vinyl alcohol copolymer, polyvinyl alcohol and polyester can be used. To be selected. For confectionery, fiber packaging, etc., polypropylene, which has good transparency, rigidity, and water permeation resistance, can be selected as the outer layer. If the substrate is a polymer, it may be uniaxially or biaxially stretched.

Effects of the Invention The modified polyolefin composition for adhesion according to the present invention,
(A) ethylene / α-olefin random copolymer,
Since it contains (B) a tackifier and (C) a specific high-pressure low-density polyethylene, it exhibits excellent adhesiveness to various substrates, and particularly reduces the neck-in phenomenon that occurs during extrusion lamination. You can

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Examples 1-2 and Comparative Examples 1-2 Maleic anhydride-grafted ethylene / propylene random copolymer (MAH-EPR-I; MFR ₂ 0.5 g / 10 minutes, maleic anhydride graft ratio 0.5 g / 100 g polymer, containing ethylene Amount 80 mol%, density 0.865 g / cm ³ , crystallinity 4%) and alicyclic hydrogenated petroleum resin (trade name Alcon P125, softening point 125 ° C, bromine number 2, manufactured by Arakawa Chemical Co., Ltd.) And high-pressure process low-density polyethylene (LDPE-1MFR ₂ 9.5 g / 10 min, density 0.917 g / cm ³ ) were mixed in a tumbler at the ratio shown in Table 1, and a 40 mmφ uniaxial extruder (200 ° C. was set ( The mixture was kneaded and granulated with a dullage screw) to obtain an adhesive resin composition.

Then, on a 9 μm thick Al foil with kraft paper attached,
30 μm through the adhesive resin composition obtained as described above
A thick polyethylene terephthalate film for extrusion lamination (trade name: Mitsui PET J 125, IV = 0.79, manufactured by Mitsui Pet Resins Co., Ltd.) was two-layer extrusion laminated under the following conditions.

Extruder: For PET: 65 mmφ, 310 ° C. For adhesive resin composition: 65 mmφ, 310 ° C. Die width: 500 mm Laminating speed: 150 m / min The neck-in width (mm) of the obtained laminate was measured. The results are shown in Table 1.

The interface adhesive force [Fa] g / 15 mm width between the PET layer and the adhesive resin composition layer of the obtained laminate was determined by T-type peeling at a peeling speed of 300 mm / min.

Similarly, the interfacial adhesive force [Fb] g / 15 mm width between the Al foil layer and the adhesive resin composition layer of the obtained laminate was determined.

The results are shown in Table 1.

Example 3 Example 1 LDPE-2 instead of LDPE-1 was used (MFR ₂ 3.
Example 1 was repeated except that 7 g / 10 minutes and a density of 0.923 g / cm ³ ) were used and mixed at the ratios shown in Table 1.

The results are shown in Table 1.

Example 4 Instead of MAH-EPR-1 used in Example 1, LDPE-1 was replaced with maleic anhydride graft-modified ethylene / 1-butene random copolymer (ethylene content: 90 mol%, MFR
₂ 7.0 g / 10 minutes, maleic anhydride graft ratio 0.5 g /: 100 g polymer, density 0.887 g / cm ³ , crystallinity: 15%)
The same procedure as in Example 1 was carried out except that the mixing ratios shown in Table 1 were used.

The results are shown in Table 1.

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Claims (1)

[Claims] (A) Graft amount: 0.01 to 10% by weight Melt flow rate: 0.1 to 50 g / 10 min Density: 0.850 to 0.900 g / cm ³ Ethylene content: 30 to 95 mol% Crystallinity by X-ray : 40% or less, Graft-modified ethylene partially or wholly graft-modified with unsaturated carboxylic acid or its derivative
α-Olefin random copolymer ········································································································ 1-50 to 10% by weight. A modified polyolefin composition for adhesion, characterized in that it comprises 0.940 g / cm ³ of high-pressure low-density polyethylene ... 1-40% by weight.