JPH05156096A - Adhesive composition and laminate produced by using the same - Google Patents

Abstract

PURPOSE:To provide an adhesive composition having improved adhesiveness especially to paper and exhibiting extrusion moldability with remarkably improved necking and edge fluctuation in the case of extrusion, e.g. a coextrusion with a saponified ethylene-vinyl acetate copolymer and to provide a laminate produced by using the composition. CONSTITUTION:The objective adhesive composition (and laminate containing the composition) is composed of (A) an essentially linear low-density polyethylene, (B) a low-density high-pressure polyethylene, (C) an ethylenic polymer modified with an unsaturated carboxylic acid or its derivative (the ethylenic polymer is ethylene homopolymer or a random copolymer of ethylene and other alpha-olefin accounting for <=10mol% based on the sum of the ethylene and the other alpha-olefin) and (D) a tackifier. The amounts of the components A, B, C and D are independently 30-80wt.%, 1-50wt.%, 1-30wt.% and 1-30wt.% based on the sum of A to D, respectively.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an adhesive composition and a laminate using the same. More specifically, it relates to an adhesive composition which exhibits good moldability and adhesiveness when a saponified product of ethylene and vinyl acetate copolymer is laminated on paper, and a laminate using the same.

[0002]

2. Description of the Related Art Conventionally, a composition containing a substantially linear low density polyethylene and a modified ethylene polymer as an adhesive for laminating a saponified product of ethylene and vinyl acetate copolymer on paper. Is used.

However, such a composition does not have sufficient adhesiveness to paper, and it is desired to improve the adhesiveness.

Also, when laminating, the adhesive composition is generally coextruded with, for example, a saponified product of ethylene and a vinyl acetate polymer, and brought together with the paper so that the layer of adhesive composition is in contact with the paper. The method is industrially implemented advantageously. However, the above-mentioned conventional compositions are apt to cause necking and wiggle during coextrusion, and in particular, when the extrusion speed is increased, it becomes more remarkable, and there is a problem to be improved.

[0005]

An object of the present invention is to provide an adhesive composition. Another object of the invention is to provide an adhesive composition with enhanced adhesion, especially to paper.

Yet another object of the present invention is an improved extrusion which, when extruded, for example with a saponified product of ethylene and vinyl acetate copolymer, has a markedly improved degree of necking and waving. An object is to provide an adhesive composition exhibiting moldability. Still another object of the present invention is to provide a laminate using the adhesive composition of the present invention. Further objects and advantages of the present invention will be apparent from the following description.

[0007]

According to the present invention, the above objects and advantages of the present invention are as follows: (A) substantially linear low density polyethylene; (B) high pressure low density polyethylene; (C) an ethylene-based polymer modified with an unsaturated carboxylic acid or a derivative thereof, wherein the ethylene-based polymer is an ethylene homopolymer, or based on the total number of moles of ethylene and other α-olefins. It is a random copolymer of ethylene and an α-olefin other than ethylene in which the α-olefin other than ethylene accounts for 10 mol% or less, and (D) contains a tackifier, and (E) above (A). ) Component, (B) component, (C) component, and (D) component based on the total weight of component (A) component 30 ~.
80% by weight, 1 to 50% by weight of the component (B), and 1 to 30 independently of the components (C) and (D).
Achieved by an adhesive composition, characterized in that it accounts for% by weight.

The adhesive composition of the present invention is as described above.
It contains four components of (A), (B), (C) and (D). The component (A), which is a substantially linear low density polyethylene, preferably has a density of 0.94 g / cm ³ or less and a density of 1 or less.
It has a melt index value of -50 g / 10 min. This linear low-density polyethylene is a copolymer of ethylene and α-olefin, and the content of α-olefin is 10 mol% or less. Further, as the α-olefin, one having 3 to 20 carbon atoms is usually used. Examples of such olefins include propylene, 1-butene, 1-hexene,
4-methyl-1-pentene, 1-octene, 1-decene and the like can be mentioned.

The high-pressure low-density polyethylene as the component (B) preferably has a density of 0.93 g / cm ³ or less and a density of 0.93 g / cm ³ or less.
It has a melt index value of 1 to 50 g / 10 minutes.

The component (C) is obtained by modifying an ethylene homopolymer with an unsaturated carboxylic acid or a derivative thereof, or based on the total number of moles of ethylene and other α-olefins, the amount of ethylene A random copolymer in which α-olefin accounts for 10 mol% or less, preferably 5 mol% or less is modified with an unsaturated carboxylic acid or its derivative.

Examples of unsaturated carboxylic acids or derivatives thereof include acrylic acid, maleic acid, fumaric acid,
Tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, nadic acid (endocis-
Unsaturated carboxylic acids such as bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid); or derivatives thereof such as acid halides, amides, imides, anhydrides and esters.

Specific examples of such derivatives include, for example:
Maleny chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate and the like can be mentioned. Of these, unsaturated dicarboxylic acids or acid anhydrides thereof are preferable, and maleic acid, nadic acid or acid anhydrides thereof are particularly preferably used.

The α-olefin random copolymer before modification includes ethylene and other α-olefins in which the amount of α-olefins other than ethylene is 10 mol% or less based on the total number of moles of ethylene and other α-olefins. Is a random copolymer of.

As α-olefins other than ethylene,
An α-olefin having 3 to 20 carbon atoms is preferably used. Examples of the α-olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-tetradecene,
1-octadecene etc. are mentioned. These α-olefins are used alone or in combination of two or more.

The α-olefin accounts for 10 mol% or less, preferably 5 mol% or less, based on the total number of moles of ethylene constituting the random copolymer. If the content of α-olefin exceeds 10 mol%, blocking due to stickiness is likely to occur and handling becomes difficult, which is not preferable.

The ethylene polymer (C) modified with an unsaturated carboxylic acid or its derivative is preferably 0.05 to 15% by weight, more preferably 0.1% by weight, based on the ethylene polymer before modification. Graft-modified with 10% by weight of unsaturated carboxylic acid or its derivative.

The modified ethylene polymer (C)
Preferably has a melt flow rate (MFR) of 0.1 to
50 g / 10 minutes, more preferably MFR 0.3-30 g
/ 10 minutes. Melt flow rate is ASTM D1
It measured according to 238 (190 degreeC, load 2160g).

The tackifier as the component (D) is preferably a solid amorphous polymer and is usually used as a tackifying resin in the fields of adhesive tapes, paints and hot melt adhesives.

The following resins can be exemplified by the difference in the sources of monomers to be polymerized. For example, C ₄ fraction, C ₅ fraction obtained by cracking petroleum, naphtha, etc., a mixture thereof or any fraction thereof, for example, isoprene and 1,3-pentadiene in the C ₅ fraction as main raw materials. Aromatic hydrocarbon resin containing; Aromatic hydrocarbon resin containing styrene derivative and indene as main raw materials in C ₉ fraction obtained by decomposition of petroleum, naphtha, etc .; C ₄ and C ₅
Aliphatic / Aromatic Copolymerized Hydrocarbon Resin Copolymerized with Any Fraction of Fraction and C ₉ Fraction; Alicyclic Hydrocarbon Resin Hydrogenated with Aromatic Hydrocarbon Resin; Aliphatic and Alicyclic Synthetic terpene hydrocarbon resin having structure containing aromatic group and aromatic group; Terpene hydrocarbon resin derived from α, β-pinene in turpentine oil; Indene and styrene derived from coal tar naphtha Malon indene type hydrocarbon resin; low molecular weight styrene type resin and rosin type hydrocarbon resin can be mentioned.

The adhesive composition of the present invention contains 30 to 80% by weight of the component (A), based on the total weight of the components (A), (B), (C) and (D). (B)
Ingredients make up 1-50% by weight, and both components (C) and (D) independently make up 1-30% by weight.

If the amount of the component (B) is less than 1% by weight, no necking or swaying effect is obtained, and if it exceeds 50% by weight, the heat-resistant adhesive property is deteriorated. The preferable ratio of the component (B) is 1 to
It is 30% by weight. If the content of the component (C) is less than 1% by weight, the adhesiveness will not be exhibited, and if it exceeds 30% by weight, the adhesiveness will not be enhanced and the economic efficiency will be lowered. If the content of the component (D) is less than 1% by weight, the adhesiveness will not be exhibited, and if it exceeds 30% by weight, blocking tends to occur, which causes a problem in handling.

The adhesive composition of the present invention may further contain a random copolymer (F) of ethylene and α-olefin, in addition to the above components. The component (F) preferably accounts for 30% by weight or less based on the total weight of the components (A) to (D) and the component (F).

The random copolymer (F) of ethylene and α-olefin exhibits a crystallinity of preferably 30% by weight or less, more preferably 25% by weight or less.

As the α-olefin, an α-olefin having 3 to 20 carbon atoms is preferably used. Examples of the α-olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1
-Decene, 1-tetradecene, 1-octadecene and the like. These α-olefins may be used alone or
Can be used in combination with more than one species.

The above α-olefin preferably accounts for 5 to 55 mol%, more preferably 10 to 55 mol%, based on the total number of moles of ethylene constituting the random copolymer.

As the random copolymer of ethylene and α-olefin, for example, a random copolymer of ethylene and propylene and a random copolymer of ethylene and 1-butene are particularly preferably used.

The adhesive composition of the present invention adheres to, for example, high-pressure low-density polyethylene (HPLDP) and the like, and particularly exhibits excellent adhesion to saponified ethylene / vinyl acetate copolymer and paper. Therefore, according to the present invention, a laminate is advantageously provided in which a layer of saponified ethylene / vinyl acetate copolymer, a layer of the adhesive composition of the present invention and paper are present in this order.

The above-mentioned laminate of the present invention is industrially advantageous, for example, by co-extruding a saponified ethylene / vinyl acetate copolymer and the adhesive composition of the present invention, and then co-extruding it with paper. Can be manufactured. The adhesive composition of the present invention has a good extrudability, and therefore, the degree of necking and wiggle is remarkably improved during the coextrusion as described above.

[0029]

The present invention will be described in more detail with reference to the following examples.
The present invention is not limited to these. Example 1 (1). Substantially linear low-density polyethylene (Urutox ^(R) 20100J manufactured by Mitsui Petrochemical Co., Ltd.) 7
5 parts by weight, high-pressure low-density polyethylene (Mirason ^(R) 11P manufactured by Mitsui Petrochemical Co., Ltd.) 10 parts by weight, tackifier (Arcon P125 manufactured by Arakawa Chemical Co., Ltd., petroleum resin) 1
0 parts by weight and high-density polyethylene graft-modified with maleic anhydride (density = 0.96 g / cm ³ , MFR =
5 g by weight of 4 g / 10 minutes and a graft ratio of 2% by weight were melt-mixed at 200 ° C. using an extruder to obtain pellets.

(2). The obtained pellets (hereinafter referred to as MPE) and saponified ethylene / vinyl acetate copolymer (Kuraray Co., Ltd., Eval EP-E105B, hereinafter referred to as EVOH) are used in the following apparatus: 2 layers Extrusion Laminator Extruder made by Sumitomo Heavy Industries Extruder: MPE 65mmφ, L / D = 32 EVOH 65mmφ, L / D = 32 Black box: rectangular pipe confluence method confluence angle 30 ° MPE side straight, EVOH side side converging Die: straight Using a tear drop type manifold, the following molding conditions: Thickness composition MPE / EVOH (EP-E105B)
= 10/30 μ, adherend kraft paper, basis weight 50 g / m ^2, molding temperature 230 ° C., take-up speed 80 m / min, and coextrusion and lamination were performed.

The following items were evaluated for the obtained laminate. Lamination suitability: Degree of neck-in Adhesion: Paper / MPE T-Peel strength (30
0 mm / min) MPE / EVOH T-Peel strength (300 mm / m
in) The results are shown in Table 1.

Example 2 An experiment was conducted in the same manner as in Example 1 except that the addition amount of the substantially linear low density polyethylene was changed to 65 parts by weight and the addition amount of the tackifier was changed to 20 parts by weight. .. The results are shown in Table 1.

Example 3 An experiment was conducted in the same manner as in Example 1 except that the addition amount of the substantially linear low density polyethylene was 55 parts by weight and the high pressure method low density polyethylene was 30 parts by weight. The results are shown in Table 1.
It was shown to.

Comparative Example 1 An experiment was conducted in the same manner as in Example 1 except that the addition amount of the substantially linear low density polyethylene was changed to 85 parts by weight and no high pressure method low density polyethylene was used. The results are shown in Table 1.

Comparative Example 2 An experiment was conducted in the same manner as in Example 1 except that the addition amount of the substantially linear low density polyethylene was 85 parts by weight and no tackifier was used. The results are shown in Table 1.

[0036]

[Table 1]

Example 4 (1). Substantially linear low density polyethylene (Urutox ^(R) 25100J manufactured by Mitsui Petrochemical Co., Ltd.) 6
5 parts by weight, 10 parts by weight of a random copolymer of ethylene and propylene (Tufmer P0280 manufactured by Mitsui Petrochemical Co., Ltd., 80 mol% ethylene, 20 mol% propylene),
High-pressure method low-density polyethylene (Mitsui Petrochemical Industry Co., Ltd., Mirason ^(R) 11P) 10 parts by weight, tackifier (Arakawa Chemical Co., Ltd. Alcon P125, petroleum resin) 10 parts by weight, and graft modification with maleic anhydride. High density polyethylene (density = 0.96 g / cm ³ , MFR = 4 g / 10
5 parts by weight of graft fraction (2% by weight) was melt-mixed at 200 ° C. using an extruder to obtain pellets. (2). The same operation as in Example 1. (2) was performed on the obtained pellets. The results are shown in Table 2.

Examples 5 to 8 and Comparative Examples 3 to 5 Adhesive compositions having the compositions shown in Table 1 were prepared in the same manner as in Example 1. (1), and were prepared as Example 1. (2). A laminate was prepared in the same manner. The results are shown in Table 2.

[0039]

[Table 2]

[0040]

Claims (4)

[Claims] 1. An ethylene-based polymer modified by (A) a substantially linear low-density polyethylene, (B) a high-pressure low-density polyethylene, (C) an unsaturated carboxylic acid or a derivative thereof, wherein the ethylene is used. The system polymer is an ethylene homopolymer, or ethylene and the other α-olefin in which the α-olefin other than ethylene accounts for 10 mol% or less based on the total number of moles of ethylene and the other α-olefin. Is a random copolymer of, and (D)
30% to 80% by weight of the component (A) based on the total weight of the component (A), the component (B), the component (C) and the component (D). , (B)
1 to 50% by weight of components, and (C) component and (D)
An adhesive composition characterized in that each component independently accounts for 1 to 30% by weight. 2. The adhesive composition comprises (F) ethylene and α
-The composition further comprises a random copolymer of olefin, and the component (F) accounts for 30% by weight or less based on the total weight of the components (A) to (D) and the component (F). The adhesive composition described. 3. A laminate in which a layer of saponified ethylene / vinyl acetate copolymer, a layer of the adhesive composition of claim 1 and paper are present in this order. 4. A laminate in which a layer of saponified ethylene / vinyl acetate copolymer, a layer of the adhesive composition of claim 2 and paper are present in this order.