JPH08157527A - Modified high-nitrile copolymer and its laminate - Google Patents

Abstract

PURPOSE: To obtain a modified high-nitrile copolymer capable of firm melt bonding with a modified polyolefin such as a carboxyl-modified polyolefin, an acid-anhydride-modified polyolefin or an epoxy-modified polyolefin in molding. CONSTITUTION: This copolymer is obtained by treating a high-nitrile copolymer essentially consisting of a vinyl cyanide monomer and an unsaturated carboxylic acid ester monomer and having a content of the vinyl cyanide monomer of 50-95wt.% with an amino alcohol.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention has excellent gas barrier properties against oxygen, nitrogen, carbon dioxide, etc. and liquid barrier properties against water, gasoline, alcohols, etc., and also includes a carboxyl group-containing polyolefin, an acid anhydride-containing polyolefin, The present invention relates to a modified high nitrile copolymer having excellent melt adhesion with a modified polyolefin such as an epoxy group-containing polyolefin. Such a modified high nitrile copolymer is useful as a material for a large-scale multi-layer container for gasoline and the like, a material for a multi-layer container for foods, cosmetics and the like, a packaging material and the like.

[0002]

2. Description of the Prior Art High nitrile copolymers are excellent in gas barrier property and liquid barrier property, but have a drawback that they are inferior in adhesiveness to polyolefin.

For this reason, various studies have been made to improve the adhesion between the high nitrile copolymer and the polyolefin. For example, (1) a high nitrile copolymer having an acrylic ester monomer is used and an acid is used as an adhesive layer. Method using polyolefin containing anhydride graft-modified polyolefin (Japanese Patent Publication No. 54-41634), (2) Method using elastomer such as styrene-butadiene copolymer as adhesive layer between high nitrile resin and polyolefin (JP 62-220436) and (3) a method of using a mixture of an elastomer and a modified polyolefin as an adhesive layer (Japanese Patent Publication No. 1-52180). However, since these laminates have insufficient adhesive force between resins, mechanical strength such as impact resistance cannot be sufficiently obtained, and there is a practical problem when they are used for containers.

There is also known a method of imparting adhesiveness to a polyolefin by applying an adhesive containing a compound capable of dissolving a high nitrile resin (Japanese Patent Laid-Open No. 63-20378). It is not possible to obtain the adhesiveness in the state.

[0005]

Modified polyolefins such as carboxyl group-containing polyolefins, acid anhydride-containing polyolefins and epoxy group-containing polyolefins have good adhesion to polyolefins, and high nitrile copolymers can bond to modified polyolefins. If so, it is possible to bond the high nitrile copolymer and the polyolefin. Therefore,
An object of the present invention is to provide a modified high nitrile copolymer capable of performing strong melt adhesion with a modified polyolefin during molding and capable of molding a multilayer thick plate, a large container and the like, and a laminate thereof.

[0006]

Means for Solving the Problems The present inventor has conducted extensive studies in order to solve the above problems. As a result, the above-mentioned problem includes at least a vinyl monomer containing a nitrile group and an unsaturated carboxylic acid ester monomer, and the vinyl monomer content containing the nitrile group is 50 to 95% by weight.
It was found that the modified high nitrile copolymer obtained by treating the above high nitrile copolymer with an alcohol having an amino group can solve the problem. The present invention will be described in detail below.

The high nitrile copolymer used in the present invention contains at least a vinyl monomer having a nitrile group and an unsaturated carboxylic acid ester monomer, and has a vinyl monomer content of 50 to 95 containing a nitrile group.
% By weight.

Vinyl monomers having a nitrile group are
It is shown by (I).

Embedded image However, R ¹ is a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, or halogen. As the vinyl monomer having a nitrile group, acrylonitrile, methacrylonitrile,
Ethacrylonitrile, α-chloroacrylonitrile, α
-Fluoroacrylonitrile and the like can be mentioned.

The content of the vinyl monomer having a nitrile group in the high nitrile copolymer is 50 to 95% by weight,
60 to 80% by weight is preferable, and 65 to 75% by weight is particularly preferable. If the content of the vinyl monomer having a nitrile group is less than 50% by weight, the barrier property is insufficient, and 9
If it exceeds 5% by weight, the thermal decomposition temperature and the melting temperature are close to each other, which makes molding process difficult.

The unsaturated carboxylic acid ester monomer is a carboxylic acid ester having one or more carbon-carbon double bonds in the molecule, and specifically, methyl acrylate, ethyl acrylate, propyl acrylate, Methyl methacrylate, ethyl methacrylate, propyl methacrylate and the like can be mentioned.

The high nitrile copolymer may contain a third component in addition to the vinyl monomer having a nitrile group and the unsaturated carboxylic acid ester monomer. As the third component, an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, an epoxy group-containing unsaturated ester, an aromatic vinyl, a homopolymer of a conjugated diene, or a copolymer of a conjugated diene and a comonomer is used. Particularly, it is preferable to copolymerize a conjugated diene homopolymer or a copolymer of a conjugated diene and a comonomer as the third component because the impact resistance is improved.

As the third component, specifically, acrylic acid, methacrylic acid, maleic anhydride, oleic acid, itaconic acid, glycidyl methacrylate, allyl glycidyl ether, styrene, polybutadiene, butadiene-acrylonitrile copolymer, butadiene- Examples thereof include styrene copolymers.

The modified high nitrile copolymer of the present invention can be obtained by treating the high nitrile copolymer and an alcohol having an amino group.

The alcohol having an amino group means a monohydric or polyhydric alcohol having at least one amino group (-NH ₂ ) in the molecule, and among them, one amino group and one hydroxyl group are present in the molecule. Monoaminoalcohols having one by one are preferred.

Specific examples of the alcohol having an amino group include aminoethylethanolamine, ethanolamine, hydroxylamine, β-aminoisobutanol, 4-aminophenethyl alcohol, 2- (2-aminoethylamino) ethanol and 2 -Amino-2-ethyl-1,3-propanediol, aminopropanol, aminohexanol, aminomethylphenol, aminomethylbutanol, aminomethylpropanol and the like can be mentioned.

When the high nitrile copolymer is treated with an alcohol having an amino group, a part of the ester group and a part of the nitrile group of the high nitrile copolymer are removed under a basic atmosphere due to the presence of the alcohol having an amino group. It is considered that a carboxyl group is generated by hydrolysis and a dehydrated amide bond is formed by the reaction with an amino group of an alcohol having an amino group to form a modified high nitrile copolymer having a hydroxyl group in the molecule.

In the treatment, the alcohol having an amino group may be added in a molten state which is higher than the melting point of the high nitrile copolymer, or the high nitrile copolymer may be immersed in an aqueous alcohol solution having an amino group. Good.

When the treatment is carried out in the molten state, the alcohol having an amino group is generally within a concentration range of 0.01 to 10% by weight, preferably 0.05 to 4% by weight, based on the high nitrile copolymer. Added. Below 0.01% by weight,
The modified high nitrile copolymer has insufficient adhesion. On the other hand, if it exceeds 10% by weight, the heat resistance and barrier properties of the modified high nitrile copolymer will be deteriorated. This is due to an acid amide group (-CON
It seems that H ₂ ) is generated.

In an alcohol aqueous solution having an amino group,
When performing the treatment reaction by immersing the high nitrile copolymer,
The aqueous solution concentration of the alcohol having an amino group is generally 0.01 to 10% by weight, preferably 0.05 to 4% by weight. When it is less than 0.01% by weight, the adhesive strength of the modified high nitrile copolymer becomes insufficient. On the other hand, 10
If the content is more than wt%, the heat resistance and barrier properties of the modified high nitrile copolymer will deteriorate. This is also considered to be due to the formation of an acid amide group due to a side reaction of hydrolysis of the nitrile group.

The treatment temperature is generally 30 to 95 ° C., and
0-90 degreeC is preferable. If the temperature is lower than 30 ° C., the modification treatment is insufficient, and if the temperature exceeds 95 ° C., a temperature change occurs, which is not preferable.

Further, the high nitrile copolymer is preferably in a shape having a large surface area, that is, in the form of powder in order to enhance the reactivity.

The hydroxyl group in the modified high nitrile copolymer obtained by the above treatment reaction is chemically combined with the functional group of the modified polyolefin such as the carboxyl group-containing polyolefin, the acid anhydride-containing polyolefin and the epoxy group-containing polyolefin during the molding process. It is considered to react and enables strong melt adhesion. As a result, it is possible to obtain a laminate using the adhesion with the modified polyolefin, and it is possible to form a multi-layer thick plate, a large container, or the like.

[0023]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. First, the high nitrile copolymer used, the modified polyolefin as the adhesive material, and the peel strength will be described.

(A) High nitrile copolymer 70 parts by weight of acrylonitrile, 30 parts of methyl acrylate
Parts by weight, 1.0 part by weight of lauryl peroxide as a catalyst, and 1.8 of a chain transfer agent, n-dodecyl mercaptan.
Polymerization was carried out at a ratio of 70 parts by weight of water to 30 parts by weight of a mixture of parts by weight. At this time, 1.2 parts by weight of tricalcium phosphate and 0.24 parts by weight of sodium dodecylbenzenesulfonate were used as a dispersant and dispersed. By this suspension polymerization, a high nitrile copolymer (N-1) having a composition ratio of acrylonitrile of 76% by weight and methyl acrylate of 24% by weight was obtained.

(B) Acid anhydride-containing polyolefin Melt flow rate is 1.0 g / 10 min (JIS-
According to K-6760. The load is 2.16 kg,
0.3 parts by weight of maleic anhydride and 2,5-dimethyl-2,5-di (tertiary-butylperoxine) per 100 parts by weight of linear high-density polyethylene having a density of 0.945 g / cm ^3. 0.01 parts by weight of hexane was previously mixed using a Henschel mixer, and the resulting mixture was 40 mmφ.
Modified polyethylene (GPE-1) grafted with maleic anhydride obtained by melt-kneading at a resin temperature of 270 ° C. using a single-screw extruder.

(C) Epoxy group-containing polyolefin Melt flow rate is 5.0 g / 10 min (JIS-
According to K-6760. The load is 2.16 kg,
0.6 part by weight of glycidyl methacrylate and 2,5-dimethyl-2,5-di (tertiary-butylperoxine) hexane per 100 parts by weight of linear high-density polyethylene having a density of 0.945 g / cm ^3. 0.04 parts by weight was previously mixed using a Henschel mixer, and the resulting mixture was melt-kneaded at a resin temperature of 250 ° C. using a 40 mmφ single screw extruder, and then unreacted and homopolymerized glycidyl methacrylate was mixed with acetone. Modified polyethylene (GPE-2) grafted with glycidyl methacrylate obtained by washing and removal.

(Peeling Strength) The test pieces for the adhesion peeling test used in the following Examples and Comparative Examples were the modified high nitrile copolymer, which was heated at 200 ° C. for 5 minutes under heating and under pressure 6
A press plate having a thickness of 1 mm was prepared under a molding condition of 0 kg / cm ² , and a modified polyolefin press plate as an adherend was prepared by the same operation. The above two press plates were melt-bonded by a hot press molding machine under various conditions and then cut into a width of 10 mm to obtain a laminated test piece. The peel strength was measured by T-type peeling of the laminated test piece having a width of 10 mm at a speed of 50 mm / min using a tensile tester.

(Example 1) High nitrile copolymer (N-
1) 0.1% by weight of monoethanolamine was added to 99.9% by weight, and this mixture was melt-kneaded by a Brabender at 140 ° C., 30 rpm for 2 minutes to give a modified high nitrile copolymer (A -1) was obtained. 1. Using an acid anhydride-containing polyolefin (GPE-1) as an adherend, laminate test pieces were heated by a hot press molding machine at 160 ° C.
It was prepared under the conditions of 5 minutes and a pressure of 10 kg / cm ² . The results of measuring the peel strength are shown in Table 1.

Example 2 A hot press molding temperature was set to 2
The same operation as in Example 1 was carried out except that the operation was carried out at 00 ° C. The results are shown in Table 1.

Example 3 The modified high nitrile copolymer (A-2) was prepared in the same manner as in Example 1 except that 0.2% by weight of monoethanolamine was added to the high nitrile copolymer. ) Got. Using an acid anhydride-containing polyolefin as an adherend, a laminated test piece was prepared by a hot press molding machine under the conditions of 200 ° C., heating for 2.5 minutes, and pressure of 10 kg / cm ² , and the peel strength was measured. The results are shown in Table 1.

Example 4 The peel strength was measured in the same manner as in Example 2 except that the epoxy group-containing polyolefin (GPE-2) was used as the adherend. The results are shown in Table 1.

Example 5 90% of high nitrile copolymer was added to 5% by weight aqueous solution of monoethanolamine.
Immerse at 60 ° C. for 60 minutes to make a modified high nitrile copolymer (A-
3) was obtained. Using an acid anhydride-containing polyolefin (GPE-1) as an adherend, a laminated test piece was prepared at a hot pressing temperature of 200 ° C, and the peel strength was measured.

Example 6 The peel strength was measured under the same conditions as in Example 5 except that the epoxy group-containing polyolefin (GPE-2) was used as the adherend.

Comparative Example 1 15% by weight of monoethanolamine based on the high nitrile copolymer (N-1)
Was added and the mixture was added to 140 by Brabender.
Melt kneading was performed at 30 ° C. for 2 minutes at 30 ° C. to obtain a modified high nitrile copolymer (A-4). The peel strength was measured using an acid anhydride-containing polyolefin (GPE-1) as the adherend.

(Comparative Example 2) The peel strength was measured under the same conditions as in Comparative Example 1 except that an epoxy group-containing polyolefin (GPE-2) was used as the adherend.

(Comparative Example 3) High nitrile copolymer (N-
A laminated test piece was prepared from 1) and an acid anhydride-containing polyolefin (GPE-1) at a hot pressing temperature of 200 ° C., and the peel strength was measured. The results are shown in Table 1.

Comparative Example 4 Comparative Example 3 except that an epoxy group-containing polyolefin (GPE-2) was used as the adherend.
The peel strength was measured under the same conditions as in. The results are shown in Table 1. Table 1 shows the results of the peel strengths of Examples 1 to 6 and Comparative Examples 1 to 4.

[0038]

[Table 1]

[0039]

The modified high nitrile copolymer having excellent melt adhesion of the present invention has excellent barrier properties against gas and liquid, and also has a carboxyl group-containing polyolefin, an acid anhydride-containing polyolefin, and an epoxy group-containing polyolefin during molding. Since it has a tough melt adhesiveness with modified polyolefins such as the above, it is useful as a multi-layer sheet and a multi-layer container utilizing the adhesion with the modified polyolefins. It is considered that the modified high nitrile copolymer of the present invention has a strong melt adhesiveness to the modified polyolefin because of the chemical reaction with the functional group in the modified polyolefin.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Mogi 3-2 Chidoricho, Kawasaki-ku, Kawasaki-shi, Kanagawa Akira Kawasaki Plastic Research Laboratory

Claims (4)

[Claims] 1. A vinyl monomer containing at least a vinyl monomer having a nitrile group and an unsaturated carboxylic acid ester monomer and having a vinyl monomer content having a nitrile group of 5
A modified high nitrile copolymer obtained by treating a high nitrile copolymer in an amount of 0 to 95% by weight with an alcohol having an amino group. 2. The modified high nitrile copolymer according to claim 1, wherein the alcohol having an amino group is a monoamino alcohol. 3. A laminate comprising a layer comprising the modified high nitrile copolymer according to claim 1 and a layer comprising a modified polyolefin. 4. The laminate according to claim 3, wherein the modified polyolefin is any of a carboxyl group-containing polyolefin, an acid anhydride-containing polyolefin and an epoxy group-containing polyolefin.