JPH0781052B2 - Adhesive polyolefin resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyolefin-based resin composition having particularly good adhesion to a metal.

[Prior art]

Polyolefin resins are generally used in a wide range of fields because they are excellent in mechanical properties, transparency, moldability, chemical resistance and the like. In particular, in recent years, for example, automobile parts, building materials, packaging materials, and the like have been subjected to many multilayers by adhering a metal and a polyolefin for the purpose of weight reduction and enhancement of physical properties.
However, since polyolefin is non-polar and has poor reactivity, it has the drawback of poor adhesion to polar substances such as metals. Various proposals have been made to improve the adhesiveness of this polyolefin, for example, maleic anhydride,
One method is to graft unsaturated carboxylic acids such as itaconic anhydride and acrylic acid onto the polyolefin.

[Problems to be solved by the invention]

In the above-mentioned polyolefins grafted with unsaturated carboxylic acids, there is a limit to the improvement of adhesiveness even if the grafting amount is increased. Therefore, there is a demand for the development of adhesive polyolefins, especially for metals, which require greater adhesive strength. Therefore, changing the polyolefin composition,
Although the use of fillers in combination has been proposed, it is not possible to obtain the required sufficient improvement in adhesiveness.

[Means for solving problems]

In view of the above, the present inventors have conducted earnest research to improve adhesiveness based on a polyolefin resin grafted with an unsaturated carboxylic acid, and as a result, by adding the two specified antioxidants, In particular, the present invention has been completed by finding an unexpected effect that the adhesive strength with metal is remarkably increased. That is, the present invention is a total of 0.01 to 2.0 parts by weight of a phenolic antioxidant and a dithioether antioxidant with respect to 100 parts by weight of a polyolefin resin grafted with 0.01 to 10% by weight of unsaturated carboxylic acids. An adhesive polyolefin resin composition, characterized in that the content of the phenolic antioxidant in the total amount of the antioxidant is 10 to 90% by weight.

Examples of the polyolefin resin in the present invention include homopolymers of α-olefins such as ethylene, propylene and butylene, random copolymers of the α-olefins with other α-olefins, block copolymers, or mixtures thereof. Etc., and a polyolefin containing polypropylene as a main component is preferably used.

Further, the unsaturated carboxylic acids in the present invention are collectively referred to as derivatives thereof, for example, acrylic acid,
Methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid and the like, and derivatives of unsaturated carboxylic acids include acid anhydrides, esters, amides, imides, metal salts and the like, for example, maleic anhydride, citraconic acid anhydride, Itaconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, glycidyl methacrylate, maleic acid monoethyl ester,
Maleic acid diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, itaconic acid monomethyl ester, itaconic acid diethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, maleic acid-N-monoethylamide,
Maleic acid-N, N-diethylamide, maleic acid-N-
Monobutylamide, maleic acid-N, N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monoethylamide, fumaric acid-N, N-diethylamide, fumaric acid-N-monobutylamide, fumaric acid Acid-N,
N-dibutylamide, maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate,
Examples thereof include sodium methacrylate, potassium acrylate, potassium methacrylate and the like. Of these, it is most preferable to use a maleic anhydride derivative or an acrylic acid derivative.

The graft amount of the unsaturated carboxylic acid to the polyolefin resin of the present invention is generally 0.01 to 10% by weight, particularly 0.05.
~ 6 wt% is preferred. When the graft polymerization amount of such unsaturated carboxylic acids is less than the above lower limit value, sufficient adhesiveness cannot be obtained, and when it is more than the above upper limit value, not only the graft polymerization becomes difficult, but also the adhesiveness It is not preferable because there is no improvement, and further, unsaturated carboxylic acids grafted at the time of molding are released and foaming easily occurs.

The grafting method of the unsaturated carboxylic acids to the above-mentioned polyolefin resin is not particularly limited, but generally, after dissolving the polyolefin-based resin in a solvent, the unsaturated carboxylic acids and a radical initiator are charged, and a method of graft polymerization, or polyolefin A method in which unsaturated carboxylic acids and a radical initiator are mixed and melt-kneaded with an extruder is used.

In the present invention, it is extremely important to blend the specified two kinds of antioxidants into the polyolefin resin grafted with the unsaturated carboxylic acids as described above in order to improve the adhesiveness of the polyolefin resin. . Conventionally, when melt-kneading an adhesive polyolefin, in order to maintain stability during heating and after molding, for example, 2,6-di-tert-butylphenol, tetrakis [methylene-3 (3,5- Di-tert-butyl-4-hydroxyphenyl) propionate comethane,
In most cases, general phenol-based and thioether-based antioxidants such as dimyristyl thiodipropionate were used, and the specified phenol-based antioxidant of the present invention was selectively used. There is no example.

The known phenolic antioxidant used in the present invention is not particularly limited, and examples thereof include 2,2-di-t-butyl-
4-methylphenol; tris- (2-methyl-4-hydroxy-5-t-butylphenyl) butane; tris-
(3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate; n-octadecyl-3- (4'-hydroxy-3 ', 5'-di-t-butylphenol) propionate; tetrakis [methylene-3 (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane; 1,3,5-trimethyl-2,4,6-tris- (3,5-di-t
-Butyl-4-hydroxybenzyl) benzene; 1,3,5-
Tris (4-t-butyl-3-hydroxy-2,6-dimethyl) isocyanurate; bis [3,3-bis (4'-
Hydroxy-3-t-butylphenyl) butanoic acid] glycol ester; 6- (4hydroxy-3,5-di-t-butylanilino) 2,4-bisoctyl-thio-1,3,5-triazine; Tris [β -(3,5-di-t-butyl-4-hydroxy-phenyl) propionyl-oxyethyl] isocyanurate; dl-α-tocopherol; triethylene-glycol-bis [3- (3-t-butyl-5-methyl) -4-Hydroxyphenyl) propionate]; 1,6
-Hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]; N, N '
-Hexamethylene-bis (3,5'-di-t-butyl-4
-Hydroxy-hydrocinamid; 2-t-butyl-6-
(3'-t-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate; 2,2'-
Ethylidene-bis (4,6-di-t-butylphenol):
2,2'-methylene bis- (4-methyl-6-t-butylphenol); 4,4'-butylidene-bis. (3-methyl-6-t-butylphenol): 4,4'-thio-bis −
(3-Methyl-6-t-butylphenol); 4,4'-methylene-bis (2,6-di-t-butylphenol); 2,2
-Thio [diethyl-bis-3 (3,5-di-t-butyl-
4-hydroxyphenol) propionate]; 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-di-ethyl ester; bis (3,5-di-t-butyl-4-hydroxybenzylphosphonic acid Ethyl) calcium; 10 · (2,6-di-t-butyl-P-cresol) 9,10
-Dihydro-9-oxa-10-phospha-phenanthrene; 2,2'-methylenebis- (4-ethyl-6-t-butylphenol; (2,6-di-t-butyl-4-ethylphenol; styrenated phenol Bis (3-methyl-4-hydroxy-5-t-butylbenzyl) sulfide and the like are used.

Examples of dithioether-based antioxidants include distearyl-di-thioether-dilauryl-dithioether; dimyristyl-di-thioether; dilauryl-
Examples thereof include dithio-dipropionate; dimyristyl dithiodipropionate; distearyl dithiodipropionate and the like, and distearyl-di-thioether is particularly preferably used.

The blending amount of the phenolic antioxidant and the dithioether antioxidant used in the present invention is 0.01 to 2.0 parts by weight, particularly 0.02 to 100 parts by weight of the unsaturated carboxylic acid-grafted polyolefin resin. 1.0 part by weight is preferred. That is, when the amount of the above-mentioned antioxidant is less than the above lower limit, a sufficient improvement in the adhesive force cannot be obtained, and even when it is more than the above upper limit, the effect of improving the adhesive force does not change, and it is a prank. It is uneconomical and meaningless, which is not preferable.

Further, the proportion of the dithioether-based antioxidant in the total amount of the above two kinds of antioxidants is 10 to 90% by weight, and particularly 20%.
% To 80% by weight is preferred. That is, when the proportion of the dithioether-based antioxidant is less than the above lower limit value, sufficient improvement of the adhesive force cannot be obtained, and when it exceeds the above upper limit value, the improvement of the adhesive force cannot be obtained, which is not preferable.

The method for producing the adhesive polyolefin resin composition in the present invention is not particularly limited, but is generally a method of adding a predetermined phenolic antioxidant and dithioether antioxidant to a polyolefin resin grafted with unsaturated carboxylic acids. A method of grafting the unsaturated carboxylic acids by adding an unsaturated carboxylic acid and a predetermined phenolic antioxidant and a dithioether antioxidant and further melting and kneading the pelletized polyolefin resin, or a polyolefin resin. This is a method in which unsaturated carboxylic acids, a predetermined phenolic antioxidant, a dithioether antioxidant and a radical initiator are simultaneously mixed and melt-kneaded to graft the unsaturated carboxylic acids. The above-mentioned mixing method is not particularly limited, and generally, a tumbler type blender, a V-type blender, a Henschel mixer or a ribbon mixer is used.

Incidentally, the adhesive polyolefin resin composition of the present invention,
It is based on a component consisting of a polyolefin resin grafted with an unsaturated carboxylic acid and a phenolic antioxidant and a dithioether antioxidant, but other than these components, a conventionally known stabilizer may be added if necessary. , Colorants, antistatic agents, lubricants, nucleating agents, flame retardants, various organic and inorganic fillers and the like may be added. In particular, the addition of an inorganic filler, more specifically, a basic inorganic filler such as calcium carbonate or calcium hydroxide is preferable because it improves the adhesion to a metal.

[Action and effect]

The adhesive polyolefin resin composition for metal of the present invention has a high degree of adhesiveness particularly to metal.

The reason why such a high degree of adhesion with a metal is obtained is not clear, but the carbonyl group of the fatty acid grafted to the polyolefin resin and the hydroxyl group of the phenolic antioxidant, and the dithioether group have a delicate hydrogen bond or the like. It is presumed that the bond may form a stronger bond with the metal atom.

〔Example〕

In order to describe the present invention more specifically, examples and comparative examples will be described below, but the present invention is not limited to these examples.

The adhesiveness tests shown in the examples and comparative examples were conducted in the following manner.

(1) Adhesion method A predetermined adhesive resin composition is sandwiched between two stainless steel (SUS 304) or aluminum metal plates (thickness 200μ) with a thickness of 450μ, and a seal bar plate (upper) and a copper plate (lower) )
And were heat-sealed at a temperature of 200 ° C. and a sealing pressure of 10 kg / cm ² for 3 minutes.

(2) Method of measuring peeling strength After fixing both ends of the metal plate heat-sealed in the above (1) with chucks, peeling speed of 20 mm / min was vertically peeled, and the strength was measured.

Example 1 100 parts by weight of a block copolymer with propylene having an ethylene content of 3.6% by weight (PN 810 manufactured by Tokuyama Soda Co., Ltd.), 1 part by weight of maleic anhydride, a radical initiator (trade name Perkadox 14, Kayaku Nouri). 0.3 parts by weight of tris (2,4-di-t-butylphenyl) phosphite 0.1 parts by weight of calcium stearate and 0.1 parts by weight of calcium stearate are mixed in a super mixer, and then melt-kneaded using a 40 m / m vented extruder. And pellets were obtained. Then, the pellets were heat-treated at 135 ° C. for 4 hours. When the pellets were formed into a film and the infrared absorption spectrum was measured, it was found that 0.6% of maleic anhydride was graft-polymerized.

20 parts by weight of the above pellets, a block copolymer with propylene having an ethylene content of 2.7% by weight (manufactured by Tokuyama Soda Co., PN
660) 80 parts by weight, calcium stearate 0.1 parts by weight,
And the predetermined antioxidant and filler shown in Table 1 were mixed and mixed with a super mixer. This was melt-kneaded using a 40 m / m vent type extruder to obtain target pellets.

Next, a sheet having a thickness of 200 μ was obtained from the above pellets by a hot pressing method (200 ° C., 10 minutes). At this time, Teflon sheets were installed at the top and bottom to create the sheet. This sheet was cut into a size of 100 × 25 mm, and sandwiched between metal plates of the same size, and heat-sealed by a specified adhesive method. After heat sealing and leaving at 23 ° C for 48 hours,
The peel strength was measured by a predetermined peel strength test. The results are also shown in Table 1.

In addition, dithioether-based thioether-based compounds which are additives of the antioxidants [I] and [II] used in Table 1,
The names and chemical structural formulas of [I] of the phenolic antioxidant and the phenolic antioxidant are shown below. Further, in Table 1, the dithioether type is classified as A and the thioether type is classified as B.

(1) Additives -1 distearyl - di - sulfide (aka: distearyl - di - thioether) (trade name Hoechst Knox SE-10, manufactured by Hoechst _{AG) CH 3 - (CH 2)} 17 -S-S- ( CH ₂ ) _17- CH ₃ (2) Additive-2 Dilauryl thiopropionate (trade name: Yoshitomi DLTP, manufactured by Yoshitomi Pharmaceutical Co., Ltd.) (3) Additive-3 Dimyristylthiodipropionate (trade name: Yoshitomi DMTP, manufactured by Yoshitomi Pharmaceutical Co., Ltd.) (4) Additive-4 distearyl thiodipropionate (trade name: Yoshitomi DSTP, manufactured by Yoshitomi Pharmaceutical Co., Ltd.) (5) Additive-5 tetrakis [methylene-3 (3,5-di-t-butyl-4
-Hydroxyphenyl) pyropionate] methane (trade name Irganox 1010, manufactured by Ciba Geigy) (6) Additive-6 1,1,3-tris (2-methyl-4-hydroxy-5-t)
-Butylphenyl) butane (Brand name Topanol CA, manufactured by ICI) (7) Additive-7 Bis [3,3-bis (4'hydroxy-3-t-butylphenyl) butanoic acid] glycol ester (Brand name TM -03, manufactured by Hoechst) Example 2 100 parts by weight of polypropylene (PN240 manufactured by Tokuyama Soda Co., Ltd.), 2 parts by weight of maleic anhydride, 0.3 parts by weight of radical initiator (trade name Kayahexa AD-40C), tris (2,4-di-t-butylphenyl) ) 0.1 part by weight of phosphite and 0.1 part by weight of calcium stearate were mixed in a supermixer, and maleic anhydride grafted PP was obtained in the same manner as in Example 1. The amount of maleic anhydride grafted on the pellets was 0.4%.

Next, 15 parts by weight of the above pellets, 85 parts by weight of the above-mentioned ethylene-propylene copolymer (PN660), 0.1 part by weight of trin (2,4-di-t-butylphenyl) phosphite, 0.1 part by weight of calcium stearate and The additives shown in Table 2 were blended in the proportions shown in Table 2 and mixed in a tumbler blender. After obtaining the target pellets in the same manner as in Example 1, the peel strength was further measured. The results are also shown in Table 2.

Example 3 100 parts by weight of a random copolymer with propylene having an ethylene content of 2.3% by weight (PN560 manufactured by Tokuyama Soda Co., Ltd.), 5 parts by weight of itaconic anhydride, a radical initiator, (Kayahexa AD-40C) 0.5.
Parts by weight, tris (2,4-di-t-butylphenyl) phosphite 0.1 parts by weight, calcium stearate 0.1 parts by weight and the additives shown in Table 3 were blended in predetermined proportions and mixed in a super mixer. Next, this was melt-kneaded by an extruder with a vent of 40 m / m to obtain target pellets. Hereinafter, the peel strength was measured in the same manner as in Example 1. These results are also shown in Table 3.

The pellets were extracted with acetone to remove unreacted itaconic anhydride, and then the amount of grafted itaconic anhydride was measured by measuring an infrared spectrum to find that it was 1.1% by weight.

Example 4 100 parts by weight of polypropylene (Polycure 1001, manufactured by Reichhold) grafted with 6% by weight of acrylic acid was mixed with the additives shown in Table 4 at a predetermined ratio and mixed by a tumbler blender. This was melt-kneaded in the same manner as in Example 1, and the peel strength in metal adhesion was measured in the same manner. The results are also shown in Table 4.

Example 5 100 parts by weight of polyethylene (PE-1000 manufactured by Toyo Soda Kogyo Co., Ltd.), 3 parts by weight of maleic anhydride, 0.5 parts by weight of a radical initiator (trade name Percadox 14) (manufactured by Kayaku Nouri Co., Ltd.),
Tris (2,4-di-t-butylphenyl) phosphite
After 0.1 part by weight and 0.1 part by weight of calcium stearate were mixed in a tumbler blender, they were melt-kneaded and heat-treated in the same manner as in Example 1. The amount of maleic anhydride grafted on the pellets was 1.5%.

Next, 30 parts by weight of the above pellets, polyethylene (PE100
0) 70 parts by weight, tris (2,4-di-t-butylphenyl)
0.1 parts by weight of phosphite, 0.1 part by weight of calcium stearate and the additives shown in Table 5 are mixed in a predetermined ratio,
Mixed with a tumbler blender. Hereinafter, in the same manner as in Example 1, after obtaining the intended pellet, the peel strength was further measured. These results are also shown in Table 5.

Claims (4)

[Claims] 1. A total of 0.01 to 2.0 parts by weight of a phenolic antioxidant and a dithioether antioxidant relative to 100 parts by weight of a polyolefin resin grafted with 0.01 to 10% by weight of unsaturated carboxylic acids. An adhesive polyolefin resin composition for metals, characterized in that the content of the dithioether antioxidant in the total amount of the antioxidant is 10 to 90% by weight. 2. The adhesive polyolefin resin composition according to claim 1, wherein the unsaturated carboxylic acid is maleic acid or acrylic acid. 3. The adhesive polyolefin resin composition according to claim 1, wherein the polyolefin resin is polypropylene. 4. The adhesive resin polyolefin composition according to claim 1, wherein the dithioether antioxidant is distearyl-dithioether.