JPS61162539A - Modified polyolefin composition for adhesive use - Google Patents

Abstract

PURPOSE:To provide a composition composed of a specific ethylene-alpha-olefin random copolymer, a tackifier, and a specific modified polyethylene, having excellent adhesivity to PS and EVOH, extrusion moldability and color tone, and giving a film having uniform thickness. CONSTITUTION:The objective composition can be produced by compounding (A) 40-98(wt)% ethylene-alpha-olefin random copolymer having a melt flow rate of 0.1-50g/10min, a density of 0.850-0.900g/cm<3>, an ethylene content of 30-95mol% and a crystallinity of <=40% determined by X-ray, with (B) 1-50% tackifier and (C) 0.1-20% modified polyethylene having a density of 0.905-0.980g/cm<3> and a crystallinity of >=45% determined by X-ray and grafted with 0.01-10% unsaturated carboxylic acid or its derivative. It is laminated with PS (polystyrene resin) and EVOH (saponified olefin-vinyl acetate copolymer) and used suitably as a packaging material for foods, medicines, etc. having excellent gas-barrier property and moisture-proofing property.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a modified polyolefin composition with excellent adhesive properties. More specifically, polystyrene and/or ethylene.
A modified polyolefin composition comprising a low-crystalline or non-quality ethylene/α-olefin random copolymer that has excellent adhesion with a saponified vinyl acetate copolymer and extrusion processability, a tackifier, and modified polyethylene. .

[Conventional technology]

Olefin-vinyl acetate copolymer M products (hereinafter sometimes abbreviated as BVOH), such as saponified ethylene-vinyl acetate copolymers, have excellent gas barrier properties, oil resistance, mechanical strength, etc., but have low moisture permeability. Because of its high viscosity, it has the disadvantage that it cannot be used alone for food packaging films, hollow containers, etc. that contain moisture. As a method to improve this drawback, it has been proposed to laminate styrene-based resins (hereinafter sometimes abbreviated as PS) or polyolefin-based resins, which have excellent water resistance, but since these resins do not have polar groups, Direct E
Even when laminated with VOH, the interlayer adhesion strength is extremely low, making it impractical for practical use.

Therefore, various methods have been proposed to improve this drawback.
For example, a method using a composition of ethylene/vinyl acetate copolymer (hereinafter sometimes abbreviated as EV^) and a tackifier (
JP-A-53-129271, JP-A-53-147
No. 733, JP-A-54-10384, etc.), or a polyolefin composition prepared by blending EVA and an aliphatic petroleum resin with a modified polyolefin (JP-A-53-10384, etc.).
No. 127546 @) has been proposed. However, tackifiers such as rosin, ester gum, cyclopentadiene resin, terpene resin or β-pinene resin, which are specifically disclosed in JP-A-53-129271, etc., or tackifiers such as JP-A-53-127,546, etc. None of the disclosed adhesives made of compositions of aliphatic petroleum resin and EVA have a sufficient effect of improving the adhesion between PS and EVOH, color, and weather resistance.

Furthermore, it has been proposed to coextrude a composition prepared by adding an alicyclic or aromatic low-molecular polymer to an olefinic polymer with PS or EVO) I (Japanese Patent Publication No. 52-500).
52), but even in this method, the effect of improving adhesive strength is insufficient.

[Problem that the invention seeks to solve]

In view of this situation, the present inventors have developed a thermoplastic resin composition that has excellent adhesive properties, particularly between a styrene resin and a saponified olefin/vinyl acetate copolymer layer, extrusion moldability, hue, and uniform film thickness. As a result of various studies to obtain something,
It was found that a composition obtained by adding a modified polyethylene obtained by grafting a tackifier and an unsaturated carboxylic acid or its derivative to a low-crystalline or non-quality ethylene/α-olefin random copolymer has the above characteristics. , we have completed the present invention.

[Means for solving problems]

That is, the present invention has a melt flow rate of 0.1 to 50 g/10o+in, a density of 0.850 to 0.900 g/cffI, and an ethylene content of 30
Ethylene/α-olefin random copolymer (A) with a crystallinity of from 95 mol% to 40% by X-rays:
4o to 98M amount%, tackifier (B) l to 50
Weight % and amount of grafting of unsaturated carboxylic acid or its derivative: 0.01 to 10 weight %, density 0.905 to 0°980 g/cnl and crystallinity by X-ray: 4
The object of the present invention is to provide a modified polyolefin composition for adhesives having excellent adhesive properties and comprising 5% or more of modified polyethylene (C): 0.1 to 20% by weight.

[For production]

The ethylene/α-olefin random copolymer (A) used in the modified polyolefin composition for adhesives (hereinafter simply referred to as the composition) of the present invention has a melt flow rate (MFR2: ASTM D 123B, L). 0
．． 1 to 50 g/10 m1n, preferably 0
．． 2 to 20 g / 10 m1n, density 0.8
50 to 0.900g/a+1, preferably 0.900g/a+1.
855 to 0.895 g/cd.

Ethylene content: 30 to 95 mol%, preferably 4
It is an ethylene/α-olefin random copolymer with a crystallinity of 0 to 92 mol% and an X-ray crystallinity of 40% or less, preferably 30% or less.

If the MFR2 is outside the above range, the melt viscosity is either too high or too low, resulting in poor moldability and adhesive strength.

If the density exceeds 0.900 g/d, the adhesive strength with PS is poor. Moreover, those whose crystallinity by X-rays exceeds 40% have poor adhesive strength with PS.

Ethylene/α-olefin random copolymer of the present invention (
The α-olefin constituting A) usually has 2 to 2 carbon atoms.
0 α-olefins, specifically for example propylene, 1
-butene, 1-hexene, 4-methyl-1-pentene,
These include 1-octene, 1-decene, 1-tetradecene, 1-octadecene, etc., each of which may be used alone or as a mixture of two or more.

Ethylene/α-olefin random copolymer of the present invention (
A) is a polyolefin with low crystallinity or poor quality as described above, and the copolymer with low crystallinity has a melting point (AST
M D 3. H8> is usually 100°C or less.

The tackifier (B) used in the composition of the present invention is a solid, non-polymer polymer, which is usually used as a tackifier resin in the fields of adhesive tapes, paints, and hot melt adhesives, and is not polymerized. Depending on the monomer source used, the following resins can be enumerated. For example, C4 fractions, C5 fractions, mixtures thereof, or any fractions thereof obtained by cracking petroleum, naphtha, etc., such as fats whose main raw materials are isoprene and 1,3-pentadiene in the C5 fractions. Aromatic hydrocarbon resins whose main raw materials are styrene derivatives and indenes in the C9 fraction obtained by cracking petroleum, naphtha, etc.
Aliphatic/aromatic copolymerized hydrocarbon resin obtained by copolymerizing any fraction of the 5 fractions with C9 fraction, alicyclic hydrocarbon resin obtained by hydrogenating aromatic hydrocarbon resin, aliphatic, alicyclic Synthetic terpene-based hydrocarbon S resin with a structure containing groups and aromatics,
Terpene hydrocarbon resin made from α, -β-pinene in turpentine oil, coumaron indene hydrocarbon resin made from indene and styrene in coal tar naphtha, low molecular weight styrenic resin, and rosin. These include hydrocarbon resins.

Among these tackifiers (C), alicyclic hydrocarbon resins obtained by hydrogenating aliphatic hydrocarbon resins and aromatic hydrocarbon resins have good dispersibility with ethylene/α-olefin random copolymers, etc. Preferably, the softening point (ring and ball method) is 105 to 150°C, preferably 1) 0 to 1
Particularly preferred are alicyclic hydrocarbons having a temperature of 40° C. and a hydrogenation rate of 80% or more, preferably 85% or more.

The modified polyethylene (c) used in the composition of the present invention is:
The amount of grafting of unsaturated carboxylic acid or its derivative is 0.
01 to 10% by weight, preferably 0.1 Ishi5Mf
#%, density 0.905 naishi 0.980 g/cj
, preferably 0.920 to 0.970 g/(
The graft-modified polyethylene has a crystallinity of 45% or more, preferably 50 to 80%, according to JI and X-rays.

The amount of grafting of unsaturated carboxylic acid, etc. is 0. If 1% by weight of O is not added, the adhesion with EνOH is not improved, while if it exceeds 10% by weight, the dispersibility decreases due to crosslinking, and f? Adhesion with V(l)l decreases. Density is 0.9
Less than 0.05g/ct1 and X-ray crystallinity 4
If the amount is less than 5%, the adhesion is improved, but there is a drawback that the product pellet is susceptible to blocking.

The polyethylene (D) that is the base of the modified polyethylene (c) used in the present invention usually has a melt flow t, -) (
MFR3: ASTM D 1238, E) is 0.
01 to 100 g/10m1n, density 0.90
5 to 0.980 g/cri, an ethylene homopolymer with a crystallinity of 45% or more by X-rays, or ethylene and a small amount of one or more other α-olefins, specifically, for example, propylene, ■-butene, It is a copolymer with 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, etc.

Examples of unsaturated carboxylic acids or derivatives thereof to be grafted onto the polyethylene (D) include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, nadic acid (endocys-bicyclo (2,2,1)hept-5-
unsaturated carboxylic acids such as ene-2,3-dicarboxylic acid), or derivatives thereof, such as acid halides, amides, imides, anhydrides, esters, etc. Specifically, maleyl chloride, maleimide, maleic anhydride, etc. , citraconic anhydride, monomethyl maleate, dimethyl maleate,
Examples include glycidyl maleate. Among these, unsaturated dicarboxylic acids or their acid anhydrides are preferred, and maleic acid, nadic acid, or their acid anhydrides are particularly preferred.

In order to produce a modified product by graft copolymerizing the graft monomer selected from the unsaturated carboxylic acids or derivatives thereof to the polyethylene (D), various conventionally known methods can be employed. For example, polyethylene (D)
There is a method of melting the material and adding a graft monomer to carry out graft copolymerization, or a method of melting it in a solvent and adding a graft monomer to carry out graft copolymerization. In any case, in order to efficiently graft copolymerize the Kaiki graft monomer, it is preferable to carry out the reaction in the presence of a radical initiator. The grafting reaction is usually carried out at a temperature of 60 to 350°C. The ratio of radical initiator used is usually 0 to 100 parts by weight of polyethylene (D).
．． 001 to 1 part by weight. As radical initiators, organic peroxides, organic bersesters 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(t
t-butylperoxyisopropyl)benzene, lauroyl peroxide, tert-butylberacetate, 2.5. Dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5
-di(tert-butylperoxy)hexane, ter
tert-butylberbenzoate, tert-butylberphenylacetate, tert-butylberisobutyrate, tert-butylber-5ec-octoate, tert-7'tilberpivalate, cumylberpivalate and tert-butylber Diethyl acetate and other azo compounds such as azobisisobutyronitrile and dimethylazoisobutyrate. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butyl peroxide),
Dialkyl peroxides such as -butylperoxy)hexane-3,2,5-dimethyl-2,5-di(tert-7'tylperoxy)hexane and 1,4-bis(tart-butylperoxyisopropyl)benzene are preferred.

The modified polyethylene (C) used in the present invention may be partially diluted with the polyethylene (D), but in that case, the total amount of grafted unsaturated carboxylic acid, etc. must be within the above range.

The adhesive polyolefin composition of the present invention has the above-mentioned ethylene
α-olefin random copolymer (A) 40 to 98
% by weight, preferably 60 to 90% by weight, the tackifier (B) 1 to 50% by weight, preferably 5 to 4
and 0.1 to 20% by weight, preferably 1 to 15% by weight of the modified polyethylene (C). Ethylene/α-olefin random copolymer (
If the amount of A) is less than 40% by weight, the fluidity of the resin will be too high, moldability will be difficult, and adhesiveness will decrease. If the amount of the tackifier (B) is less than 1% by weight, the adhesiveness to PS will decrease. If the amount of the modified ethylene polymer (C) is less than 0.1% by weight, the adhesion to BVOH will decrease.

In order to obtain the composition of the present invention, the ethylene/α-olefin random copolymer (A), the tackifier (B), and the modified polyethylene (C) can be mixed within the above range using various known methods.
For example, mixing with a Henschel mixer, V-blender, ribbon blender, tampler blender, etc., or after mixing, melt-kneading with a -screw extruder, twin-screw extruder, Nigu, Banbury mixer, etc., followed by granulation or pulverization. You can adopt a method to do so.

In addition to the above-mentioned components, the composition of the present invention may contain heat-resistant stabilizers, weather-resistant stabilizers, antistatic agents, pigments, dyes, rust inhibitors, etc. within a range that does not impair the purpose of the present invention. Good too.

Using the composition of the present invention, PS and t! As a method for manufacturing a laminated structure made of VOH, for example, a composition, ps
and EVOH are each melted in separate extruders and then supplied to a die with a three-layer structure, and the composition is coextruded as an intermediate layer.The PS layer and the BVOH layer are molded in advance, and the ps layer and the HVOI (layer) are coextruded. Examples include a so-called sandwich lamination method in which the composition is melt-extruded in between.

Among these, it is preferable to use the coextrusion molding method from the viewpoint of interlayer adhesive strength. Examples of the coextrusion molding method include the T-die method using a flat die and the inflation method using a circular die.

The flat die may be either a single manifold type using a black box or a multi-manifold type, and any known die may be used as the die used in the inflation method.

Styrenic resins (PS) used in laminated structures using the composition of the present invention include polystyrene, high-impact polystyrene (rubber compounded polystyrene), As resin (SAN
'I, ABS, etc.

The saponified olefin/vinyl acetate copolymer (BVOH) used in the laminated structure using the composition of the present invention has an olefin content of 15 to 60 mol%, preferably 2
Examples include those obtained by saponifying 5 to 50 mol% of an olefin/vinyl acetate copolymer to a degree of saponification of 50% or more, preferably 90% or more. Those with an olefin content of less than 15 mol % are easily thermally decomposed, difficult to melt and mold, have poor stretchability, and easily absorb water and swell, resulting in poor water resistance.

On the other hand, if the olefin content exceeds 60 mol%, the gas permeation resistance will be poor. Also, those having a saponification degree of less than 50% have poor gas permeation resistance. Specific examples of olefins to be copolymerized include ethylene, propylene, 1-butene, ■-hexene, 4-methyl-1-pentene, ■-octene, 1-decene, l-tetradecene, and 1-octadecene. Among these, copolymers with ethylene are preferred from the viewpoint of mechanical strength and moldability.

The thickness of each laminated structure composed of PS and IIIVOH using the composition of the present invention is such that PS is 0.02 to 5.
day, EVOH is 0.01-1 Tsuru, adhesive layer is 0.01-1
It is desirable to be within the crane range.

〔Effect of the invention〕

The modified polyolefin composition for adhesives of the present invention is similar to the conventional E
Compared to compositions of vA and petroleum resin or compositions in which modified boolefin is added, it has excellent adhesion to PS and EVQH, and has excellent color, weather resistance, extrusion moldability, film uniformity, etc. P
When laminated with S and EVOH, it can be suitably used for film packaging materials for food and medicine, air pressure molded cups, hollow layers, etc. that have excellent gas permeability and moisture resistance.

〔Example〕

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way unless the gist of the invention is exceeded.

Examples 1 to 3, Comparative Example 1.2 Ethylene-propylene random copolymer (EPR-1:
Ethylene content 80 mol%, MFR 21.2g/10m
tn, density 0.88 g/cti, crystallinity 6%) and maleic anhydride grafted high-density polyethylene (M^H-HD
PE, maleic anhydride graft rate 2.1g/100g polymer, MFR, 2.4g/10mln, density 0.9
60 g/aj, crystallinity 76%) and alicyclic hydrogenated petroleum resin (trade name Alcon P125, softening point 125°C, bromine number 2, manufactured by Aurayo Kagaku ■) in the proportions shown in Table 1 in a tumbler. The mixture was kneaded and granulated using a 40 mmφ-screw extruder (Dulmage screw) set at 200° C. to obtain an adhesive resin composition.

Next, high-impact polystyrene (trade name TOBOLEX HI33O-05 Mitsui Toatsu Chemical Co., Ltd.
/10m1n, density 1.19g/ad, ethylene content 32n+o1%, product name Kuraray Eval BP-F @
(manufactured by Kuraray) and the above adhesive resin composition to form a three-layer water-cooled inflation film under the following conditions.

Film layer composition: polystyrene (outer)/adhesive resin composition (inner)/ethylene/vinyl alcohol copolymer (inner) = 100/20/20
μ extruder: 40flφ extruder 210℃ (for outer layer) 40flφ extruder 210℃ (for middle layer) 40wφ extruder 210℃ (for inner layer) Molding speed: 15m/win The polystyrene layer of the obtained three-layer film Interfacial adhesion force (Fl) of adhesive resin composition layer (3 g/15w width) and interfacial adhesion force of ethylene/vinyl alcohol copolymer layer and adhesive resin composition layer (Fvivos g/15w width)
was determined by T-peeling at a peeling speed of 300 mm/+++in. The results are shown in Table 1.

Example 4 Instead of EPR-I used in Example 3, ethylene 1-
Table 1 Using butene random copolymer (EBR-1i ethylene content 90 mol%, MFR 27.0 g/10 m1n, density 0.887 g/cm3, crystallinity 15%)
The ponds used in the proportions shown in were conducted in the same manner as in Example 1.

The results are shown in Table 1.

Example 5 Alicyclic hydrogenated petroleum resin (trade name Alcon P135, softening point 135) was used instead of Alcon P125 used in Example 2.
The same procedure as in Example 2 was carried out except that brominated 2 (brominated 2, manufactured by Arayo Kagaku ■) was used. The results are shown in Table 1.

Example 6 Instead of Alcon P125 used in Example 2, an alicyclic hydrogenated petroleum resin (trade name Alcon P90, softening point 90°C) was used.
The same procedure as in Example 2 was carried out except that brominated 2, manufactured by Arayo Kagaku ■) was used. The results are shown in Table 1.

Example 7 Maleic anhydride grafted ethylene-1-butene copolymer (1-butene content 3.2 mol%, density 0.930 g/ct) was used instead of MAR-HDPH used in Example 2.
A, crystallinity 55%) was used in the same manner as in Example 2. The results are shown in Table 1.

Comparative Example 3 Maleic anhydride grafted HDPR (maleic anhydride grafting rate 0.3 g/100 g, MFR24, 1 g
/ 10mln, density 0.96g1014, crystallinity 7
The same procedure as in Example 1 was conducted except that Alcon P125 (6%) and Alcon P125 used in Example 1 were used in the proportions shown in Table 1. Table 1 shows the results.
Shown below.

Comparative Example 4 Ethylene/vinyl acetate copolymer (EVA: MPR2
The same procedure as in Example 1 was carried out except that Alcon P125 (2.5 g/Login, vinyl acetate content: 19% by weight) and Alcon P125 used in Example 1 were used in the proportions shown in Table 1. Table 1 shows the results.
Shown below.

Comparative Example 5 Maleic anhydride graft EV^ (MFR24, 2g/1
The same procedure as in Example 1 was carried out except that Alcon P125 used in Example 1 was used in the proportions shown in Table 1. The results are shown in Table 1.

Comparative Example 6 EvA used in Comparative Example 4, MAR-H used in Example 1
DPE and aliphatic cyclic hydrocarbon resin (softening point 100℃,
The same procedure as in Example 1 was carried out except that brominated 40% and number average molecular weight 1200) were mixed in the proportions shown in Table 1.

The results are shown in Table 1.

Claims (1)

[Claims] (1) Melt flow rate: 0.1 to 50g/10
min, density: 0.850 to 0.900g/cm^
3. Ethylene content: 30 to 95 mol% and X-ray crystallinity: 40% or less Ethylene/α-olefin random copolymer (A): 40 to 98% by weight, tackifier (B): 1 50% by weight and amount of grafting of unsaturated carboxylic acid or its derivative: 0.01 to 10
Weight%, density 0.905 to 0.980g/cm^3
and 0.1 to 20% by weight of modified polyethylene (C) having a degree of crystallinity measured by X-rays of 45% or more.