JPH0352484B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Industrial Application] The present invention relates to a method for producing a graft-modified resin composition with excellent adhesive properties, and more specifically, the present invention relates to a method for producing a graft-modified resin composition with excellent adhesive properties. The present invention relates to a method for producing a graft-modified resin composition. [Prior art] Vinyl chloride resin, vinylidene chloride resin, polyamide resin, ethylene vinyl alcohol copolymer, polyethylene resin, etc. have excellent gas barrier properties and also have good oil resistance, chemical resistance, etc. Therefore, it is suitable for various packaging materials, especially food packaging materials. However, these resins generally have poor heat-sealing properties, so they are often used in laminates with resins that have good heat-sealing properties, such as polyolefin resins, and this laminate is an excellent product that combines the features of both. Used as packaging material. However, these resins are inherently difficult to adhesively laminate with polyolefin resins, and an adhesive must be interposed between the two materials. As such adhesives, various acid-grafted polyolefins have already been proposed and have actually been used as adhesive layers in laminates with polyamide resins and ethylene vinyl alcohol copolymers, but vinyl chloride resins and vinylidene chloride resins are particularly suitable. Adhesive properties with other materials are still insufficient, and there is a strong demand in the market for an even stronger adhesive. When vinyl chloride resin or vinylidene chloride resin is used as a packaging material, an appropriate amount of plasticizer is added to these resins in order to impart properties such as flexibility necessary for the film. Thermal adhesion between a soft vinyl chloride resin and a polyolefin resin is particularly difficult, and this tendency increases as the amount of plasticizer increases, that is, as the resin becomes softer. This is thought to be because the plasticizer bleeds onto the surface of the vinyl chloride resin and inhibits adhesion to the polyolefin. Naturally, if the adhesion between the layers is insufficient,
Not only does it have a negative effect on oil resistance and heat resistance, but it also
This greatly affects the sealing strength, resulting in insufficient sealing and is no longer of practical use. [Problems to be Solved by the Invention] Therefore, the object of the present invention is to produce an adhesive that overcomes the adhesion inhibition caused by the plasticizer and firmly adheres to vinyl chloride resin, vinylidene chloride resin, etc. [Means for Solving the Problem] The present inventor has arrived at the present invention as a result of intensive studies on this problem. Combined 1 to 99 parts by weight and acrylic ester content or methacrylic ester content
0.1~30wt% and maleic anhydride content 0.05~20wt
% of ethylene-acrylic acid ester-maleic anhydride ternary copolymer or ethylene-methacrylic acid ester-maleic anhydride ternary copolymer or ethylene-methacrylate ester-maleic anhydride ternary copolymer. The present invention provides a method for producing an adhesive composition in which a resin composition is graft-modified by adding an unsaturated carboxylic acid or anhydride thereof in the presence of 0.001 to 0.5 parts by weight. In the present invention, the ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVA) as one of the resins used for graft modification has a vinyl acetate content (hereinafter abbreviated as EVA).
Vinyl acetate content (abbreviated as vinyl acetate content) is 3 to 50wt%, preferably 10
~35wt%, melt flow rate (JIS
According to K6760, the same applies hereafter) is 0.5 to 300g/
The amount is preferably 1 to 30 g/10 min for 10 min, and 1 to 99 parts by weight, preferably 30 to 90 parts by weight, is used in the resin composition. In this EVA, the vinyl acetate content is
If it is less than 3wt%, the adhesion is insufficient, and 50wt%
%, extrusion moldability decreases, and melt flow rate is less than 0.5g/10min or 300g/10min.
Even if the time exceeds 10 min, extrusion moldability deteriorates. In addition, the ethylene-acrylic ester-maleic anhydride ternary copolymer or ethylene-methacrylic ester-maleic anhydride ternary copolymer as the other resin used for graft modification has an acrylic ester content or a methacrylic ester content. Content 0.1
It is a terpolymer with ethylene containing ~30wt%, preferably 5-20wt%, and a maleic anhydride content of 0.05-20wt%, preferably 0.1-10wt%, although the melt flow rate is not particularly specified.
0.5~150g/10min preferably 1~50g/10min
99 to 1 part by weight, preferably 30 to 10 parts by weight, is used in the resin composition. In this terpolymer, the ester content is less than 5wt%, and the maleic anhydride content is 0.05wt%.
If the ester content is less than 30 wt%, the adhesion will be insufficient, and if the maleic anhydride content is more than 20 wt%, the extrudability will be poor, and the melt flow rate will be 0.5 g. /
If it is less than 10 min or exceeds 150 g/10 min, extrusion moldability will deteriorate. Examples of acrylic esters include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc., and examples of methacrylic esters include methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc.
Particularly preferred are methyl acrylate, ethyl acrylate, and methyl methacrylate. In this resin composition, when the EVA content exceeds 99 parts by weight in the compounding ratio, the adhesion to vinyl chloride resin or vinylidene chloride resin decreases, and even when the terpolymer content exceeds 99 parts by weight, the adhesion property decreases. is in short supply.
Radical generator per 100 parts by weight of this resin composition
The resin composition is graft-modified by adding an unsaturated carboxylic acid or anhydride thereof in the presence of 0.001 to 0.5 parts by weight, preferably 0.05 to 0.3 parts by weight. If the amount of the radical generator is less than 0.001 part by weight, the adhesion will be insufficient, and if it exceeds 0.5 part by weight, gel will be generated due to crosslinking, which will not only reduce the commercial value but also have a negative effect on the adhesion and extrusion molding. Examples of radical generators used for graft modification include dicumyl peroxide, benzoyl peroxide, di-t-butyl peroxide, 2,
5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexene-3, lauroyl peroxide, t-butylperoxybenzoate Organic peroxides such as
A combination of two or more types may be used. The unsaturated carboxylic acid or its anhydride used as a monomer for graft modification includes acrylic acid,
Examples include maleic acid, fumaric acid, itaconic acid, highmic acid, and anhydrides thereof, and among them, acrylic acid, maleic acid, maleic anhydride, and highmicic anhydride are preferred. Of course, two or more of these may be used in combination. Graft modification is carried out by adding a monomer for graft modification and a radical generator to the above-mentioned resin composition suspended or dissolved in an appropriate solvent, and heating and stirring the mixture; There are methods such as pre-mixing and kneading with a solvent using an extruder, Banbury mixer, kneader, etc., but the latter method is preferred when graft modification is performed using maleic acid, maleic anhydride, hymic anhydride, etc. Adopted. The amount of graft modification is not particularly limited, but may be 0.0001 to 3 parts by weight per 100 parts by weight of the resin composition. The thus obtained graft-modified adhesive resin composition of the present invention exhibits particularly excellent adhesive properties in a laminate in which vinyl chloride resin layers or vinylidene chloride resin layers are bonded. For example, any method such as coextrusion molding, extrusion coating, dry lamination, or various heat welding methods can be employed, and it is also possible to obtain a desired laminate in which layers of different resins such as polyolefin resin layers are stacked. A method of melt-extruding each resin using separate extruders and joining each layer inside a circular die, T-die, etc. or immediately after extrusion to obtain a multilayer film, multilayer sheet, multilayer blow bottle, etc. in a desired shape, that is, coextrusion molding. is economically advantageous. Molding is possible if the molding temperature is higher than the softening temperature of each resin and lower than the decomposition temperature. In the case of coextrusion molding, it is desirable from the viewpoints of adhesiveness, moldability, and physical properties that the melt viscosities of the resins constituting each layer are not extremely different. The present invention will be explained in more detail by giving examples and comparative examples below. Examples 1-6, Comparative Examples 1-2 Melt flow rate 6.0g/10min, vinyl acetate content
19wt% ethylene-vinyl acetate copolymer (hereinafter referred to as
(abbreviated as EVA) and melt flow rate 3.2g/
10min, methyl acrylate (hereinafter abbreviated as MA) content 3wt%, maleic anhydride (hereinafter MAH)
) Ethylene-MA-MAH with a content of 0.4wt%
Table 1 shows the terpolymer (hereinafter abbreviated as EMAH).
Mix in a Henschel mixer and add ghee to this.
Add t-butyl peroxide to the above resin mixture 100%
After adding 0.012 parts by weight to the pellet surface to uniformly wet the pellet surface, 0.7 parts by weight of maleic anhydride was added to make a homogeneous mixture using a Henschel mixer, and this was mixed at 200°C using a 40 mmφ extruder. A graft modified adhesive resin composition was obtained by melt mixing and extrusion. Using a coextrusion film molding device, this graft-modified adhesive resin composition was heated at a cylinder temperature of 180°C.
At a die temperature of 180℃, polyvinyl chloride resin (hereinafter referred to as
PVC) was coextruded at a cylinder temperature of 170°C and a die temperature of 180°C to obtain a coextruded film of two types and two layers (adhesive resin composition layer 20μ thick, PVC layer 60μ thick). This coextruded film was cut into pieces of 15 mm in width and 15 cm in length, one end of which was forcibly peeled off, and the peeling temperature was measured using a Tensilon type tensile tester under conditions of a tensile speed of 100 mm/min and 180 degree peeling. The results are also shown in Table 1, and the peeling temperature was excellent in Examples 1 to 6.
Comparative Examples 1 and 2 with too much EVA or EMAH were weak.

[Table] Examples 7-11, Comparative Examples 3-4 Melt flow rate 15g/10min, vinyl acetate content
25wt% EVA and melt flow rate 3.8g/
10min, ethylene with ethyl methacrylate (hereinafter abbreviated as EMA) content 4.5wt%, MAH 1.3wt%
Graft-modified resin compositions were obtained in the same manner as in Examples 1 to 6, except that the EMA-MAH terpolymer (hereinafter abbreviated as EEMAH) was used in the proportions shown in Table 2, and exfoliated in the same manner. The strength was measured. The results are shown in Table 2, and the peel strength was excellent in Examples 7 to 11, while Comparative Example 3, which had too much EVA or EEMAH,
It was weak at 4.

[Table] Examples 12 to 15 Melt flow rate 7g/10min, methyl methacrylate (hereinafter abbreviated as MMA) content 8wt%,
A graft-modified resin composition was prepared in the same manner as in Examples 1 to 6, except that MAH2.9wt% of the ethylene-MMA-MAH terpolymer (hereinafter abbreviated as EMMAH) was used in the proportions shown in Table 3. The peel strength was measured using the same method. The results are shown in Table 3, and all showed excellent adhesion to PVC.

【table】

Claims (1)

[Claims] 1 1 to 99 parts by weight of ethylene-vinyl acetate copolymer with a vinyl acetate content of 3 to 50 wt% and an acrylic ester content or a methacrylic ester content
0.1~30wt% and maleic anhydride content 0.05~20wt
% of ethylene-acrylic acid ester-maleic anhydride ternary copolymer or ethylene-methacrylic acid ester-maleic anhydride ternary copolymer or ethylene-methacrylate ester-maleic anhydride ternary copolymer. A method for producing an adhesive resin composition, which comprises adding an unsaturated carboxylic acid or its anhydride in the presence of 0.001 to 0.5 parts by weight to graft-modify the resin composition.