JPS62273241A - Adhesive polyolefin resin composition - Google Patents

Abstract

PURPOSE:To obtain an adhesive polyolefin resin composition having high adhesivity especially to metals, by using a polyolefin resin grafted with unsaturated carboxylic acid as a base and adding a metal salt of benzoic acid (derivative) to the base resin. CONSTITUTION:(A) 100pts.wt. of a resin composed mainly of a polyolefin resin, preferably polypropylene graft-polymerized with 0.01-10(wt)%, preferably 0.05-6% unsaturated carboxylic acid, preferably maleic acid (derivative) or acrylic acid (derivative) is compounded with (B) 0.01-2pts., preferably 0.02-1pt. of a metal salt of benzoic acid (derivative), preferably a compound of formula (R is H or aryl; M is metal atom; n is atomic valence of M), especially aluminum p-t-butylbenzoate and preferably further (C) a basic inorganic filler such as calcium carbonate, etc.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention particularly relates to a polyolefin resin composition that has good adhesion to metals.

[Prior art]

Polyolefin resins generally have mechanical properties.

It is used in a wide range of fields because of its excellent transparency, moldability, and chemical resistance. Particularly in recent years, many multi-layer materials have been used in automobile parts, building materials, packaging materials, etc. by bonding metals and polyolefins for the purpose of reducing weight and strengthening physical properties. However, polyolefins are non-polar, have poor reactivity, and have the drawbacks of poor adhesion to polar substances such as metals. Various proposals have been made to improve the adhesive properties of this polyolefin, including a method of grafting unsaturated carboxylic acids such as maleic anhydride, itaconic anhydride, and acrylic acid onto the polyolefin.

[Problem that the invention seeks to solve]

In polyolefins grafted with the above-mentioned unsaturated carboxylic acids, there is a limit to the improvement in adhesion even if the amount of grafting is increased.

Therefore, it is desired to develop an adhesive polyolefin, especially for metals, which is characterized by greater adhesive strength. Therefore, although it has been proposed to change the polyolefin composition or to use a filler in combination, it has not been possible to obtain the required sufficient improvement in adhesiveness.

[Means for solving problems]

In view of the above, the present inventors conducted intensive research to improve the adhesiveness of polyolefin resins grafted with unsaturated carboxylic acids, and as a result, added metal salts of benzoic acid or its derivatives. By doing so, they discovered that the adhesive strength, especially with metals, was significantly increased, leading to the completion of the present invention.

That is, the present invention provides unsaturated cardanic acids aO, O1-10ii
% of the metal salt of benzoic acid or its derivatives per 100 parts by weight of the grafted polyolefin resin.
This is an adhesive polyolefin resin composition containing 0 parts by weight.

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

In addition, the unsaturated carboxylic acids in the present invention include their derivatives, such as acrylic acid,
Methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, etc., and unsaturated carboxylic acid derivatives such as acid anhydrides, esters, amides, and imides.

There are metal salts, such as maleic anhydride, citraconic anhydride, itaconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, and 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-diethyl-amide,
maleic acid-N-monobutyramide, maleic acid-N,
N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monoethylamide, fumaric acid-
N,N-diethylamide.

Fumaric acid-N-monobutyramide, fumaric acid-N, N-
dibutylamide, maleimide, N-fubutymaleimide,
Examples include N-phenylmaleimide, sodium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate, and the like. Among these, it is most preferable to use maleic anhydride derivatives or acrylic acid derivatives.

The amount of unsaturated carboxylic acids grafted onto the polyolefin resin of the present invention is generally 0.01 to 10% by weight, particularly preferably 0.05 to 6% by weight. If the amount of graft polymerization of such unsaturated carboxylic acids is less than the above-mentioned lower limit, sufficient adhesive strength will not be obtained, and if it is more than the above-mentioned upper limit, graft polymerization will not only become difficult but also improve adhesive strength. Moreover, the unsaturated cargenic acids grafted during molding are liberated, resulting in unfavorable foaming.

The grafting method of unsaturated carboxylic acids to the polyolefin resin described above is not particularly limited, but generally, after dissolving the polyolefin resin in a solvent, unsaturated carboxylic acids and a radical initiator are added to graft polymerize the polyolefin resin. , a method of mixing unsaturated carboxylic acids and a radical initiator and melt-kneading the mixture using an extruder is adopted.

In the present invention, it is extremely important to blend a polyprimary nofin resin grafted with unsaturated carboxylic acids such as those described above, and a metal salt of benzoic acid or its derivative in order to improve the adhesiveness of the polyolefin resin. It is.

In general, metal salts of benzoic acid or its derivatives act as nucleating agents for polyolefins and increase the crystallization temperature of the polyolefins, thereby improving transparency, rigidity,
It is used for the purpose of improving dimensional stability of rings. However, it is a surprising effect that when used in combination with adhesive polyolefin, it contributes to improving adhesive strength.

As the metal salt of benzoic acid or its derivative in the present invention, any known metal salt can be used without any restriction. The metal salt of benzoic acid or its derivative which is generally suitably employed is the following formula (1
).

In the above general formula (1), the alkyl group represented by R is not particularly limited in number of carbon atoms, but preferably has 1 to 6 carbon atoms in view of easy availability. Specifically, methyl group, ethyl group, n-propyl group, 1-propyl group, n-
Butyl group, 1-butyl group, t-butyl group, pentyl group,
Examples include hexyl group. Further, the metal atom represented by M is not particularly limited as long as it forms a salt with benzoic acid or a derivative thereof. Suitable metal atoms in the present invention include alkali metals such as lithium, sodium, and potassium; alkaline earth metals such as magnesium, calcium, strontium, and barium; zinc metals such as zinc and cadmium; aluminum and gallium.

Examples include aluminum metals such as indium.

Specific examples of the metal salt of benzoic acid or its derivatives used in the present invention are as follows.

For example, benzoic acid metal salts such as sodium benzoate, potassium benzoate, lithium benzoate, magnesium benzoate, calcium benzoate, zinc benzoate, aluminum benzoate; para-t-butylbenzoate) IJum,
Potassium para-1-butylbenzoate, lithium para-t-butylbenzoate, magnesium para-t-butylbenzoate, calcium para-1-butylbenzoate, para-1
- Para-tert-butylbenzoic acid metal salts such as zinc butylbenzoate, aluminum para-1-butylbenzoate; sodium para-methylbenzoate, potassium para-methylbenzoate, lithium para-methylbenzoate, para-methyl Magnesium benzoate, calcium para-methylbenzoate.

Examples include para-methylbenzoic acid metal salts such as zinc para-methylbenzoate and aluminum para-methylbenzoate, with para-t-butylaluminum benzoate being particularly preferably used.

In the second aspect of the present invention, the amount of the metal salt of benzoic acid or its derivative added is 0.01 to 2.0 parts by weight, particularly 0.02 parts by weight, based on 100 parts by weight of the polyolefin resin grafted with unsaturated carboxylic acids. ~1.0 parts by weight is preferred. The blending ratio of the metal salt of benzoic acid or its derivatives mentioned above is 0.0
If the amount is less than 1 part by weight, sufficient improvement in adhesive strength cannot be obtained.

Regarding the method for obtaining the polyolefin resin composition of the present invention, the graft polymerization of unsaturated carboxylic acids of polyolefin and the graft polymerization of unsaturated carboxylic acids are carried out in advance without any particular limitation, such as the degree of addition of metal salts of benzoic acid or its derivatives. However, even if a metal salt of benzoic acid or its derivatives is added afterwards, the metal salt of benzoic acid or its derivatives is added,
The pelletized product may be further melt-kneaded to graft unsaturated carboxylic acids, or a metal salt of benzoic acid or its derivative and unsaturated carboxylic acids.

A radical initiator may be mixed at the same time for melt cross-wire grafting. The above-mentioned mixing method is also not particularly limited, and generally includes a tumbler set blender, a v-type blender, and a Henschel S*S+.

This is done using a ribbon mixer or the like.

The polyolefin resin composition of the present invention is basically composed of a polyolefin obtained by graft polymerization of unsaturated carboxylic acids and a metal salt of benzoic acid or a derivative thereof. Known stabilizers 1 Colorants, antistatic agents, lubricants.

A nucleating agent, a flame retardant, one each of organic and inorganic fillers, etc. may be added. In particular, the addition of inorganic fillers, particularly basic inorganic fillers such as calcium carbonate and calcium hydroxide, is preferred because it improves adhesion to metals.

[Action and effect]

The adhesive polyolefin resin composition of the present invention has particularly high adhesion to metals.

The reason why such high adhesion with metals is obtained is not clear, but the carbonyl group of the fatty acid grafted onto the polyolefin resin, the carbonyl group of the metal salt of benzoic acid or its derivatives, and the metal ion interact with each other. influence each other,
It is speculated that it may be able to form stronger bonds with metal atoms. It is possible that the metal salt of benzoic acid or its derivatives may contribute to the improvement of adhesive strength by acting as a nucleating agent, but other common nucleating agents, 1. 3.2.4-di(methylbenzylidene)
Since no effect was found with Nrubitone, it is thought that its action as a nucleating agent is small.

〔Example〕

EXAMPLES In order to explain the present invention more specifically, Examples and Comparative Examples will be given below, but the present invention is not limited to these Examples.

The adhesion tests shown in 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) to a thickness of 450μ, and the seal bar plate (top) and copper plate ( (lower) was used to heat seal for 3 minutes at a temperature of 200°C and a sealing pressure of 10 and 4/i.

(2) Method for measuring peel strength After fixing both ends of the metal plate heat-sealed in the above (1) with chucks, it was peeled upward and downward at a pulling speed of 20 @/min, and its strength was measured.

Example 1 100 parts by weight of a block copolymer with propylene containing 3.6% by weight of ethylene (manufactured by Tokuyama Soda Co., Ltd., PN810), 1 part of maleic anhydride, a radical initiator (trade name: Parkadox 14. Nouri Co., Ii 0.3ii
-51 copies.

2.6-tert-butyl-4-methylphenol 0.1 weight-Jim and 1 part by weight of calcium stearate were mixed in a super mixer, and then melt-kneaded using a 40X pent extruder to obtain a heret. Next, this pellet was heat-treated at 135° C. for 4 hours. When this pellet was made into a film and the infrared absorption spectrum was measured, it was found that 0.6% of the anhydrous malemono finished product had been graft-polymerized.

20 parts by weight of the above pellets, 80 parts of a block copolymer with propylene having an ethylene content of 2.7ii% (manufactured by Tokuyama Soda Co., Ltd., PN660), tris (2,4-jet),
0.1 part by weight of ert 4-butylphenyl) phosphite, 1 part by weight of calcium stearate Q, and the prescribed antioxidant and filler shown in Table 1 were blended and mixed in a super mixer. This was melt-kneaded using a 40% vent extruder to obtain the desired pellets.

Next, a 200 μ thick sheet of the above Beret was obtained using a hot press method (200°C, IQ sorting machine). At this time, Teflon sheets were installed on the top and bottom to create the sheet. This sheet was made into a size of 1100 x 25. Cut the pieces, place them between metal plates of the same size, and heat seal them using the prescribed adhesive method.Leave them for 48 hours (25 hours).
℃), the peel strength was measured by the peel strength test described above. These results are also listed in Table 1. The names and chemical structural formulas of each additive used in Table 1 are shown below.

(1) Additive-1 pt-butyl aluminum benzoate (trade name A4-PTBBA, Shell) (2) Additive-2 Benzoic acid IJum (Marubishi Yuka Co., Ltd.) (3) Additive -3 1,i2.4-di(methipanezylidene) rubitone (trade name: Gelol MD, Shinnichi Hs α) Additive -4 1,12,4-dibenzylidene rubitol (trade name: Gelol D, Shinnihon Chemical Co., Ltd.) Example 2 100 parts by weight of polypropylene (Tokuyama Soda Co., Ltd. gPN240), 2 parts by weight of maleic anhydride, 0.3 parts by weight of radical initiator (trade name Kayahexa AD-40C), 2,6-sheet tert-butyl-4 -0.1 part by weight of methylphenol and 0.1 part by weight of calcium stearate were mixed in a super mixer to obtain maleic anhydride grafted PP in the same manner as in Example 1. The amount of maleic anhydride grafted in this pellet was 0.4%.

Next, 15 parts by weight of the above pellet, the above ethylene-
85 parts by weight of propylene compound (P N 660 ), 0.1 part by weight of tris(2,4-di-t-butylphenyl)phosphite, 0.1 part by weight of calcium stearate
Additives and fillers shown in parts by weight and in Table 2 were blended in predetermined proportions and mixed in a tumbler blender.

After obtaining the desired pellet in the same manner as in Example 1,
Furthermore, peel strength was measured.

These results are also listed in Table 2.

Example 3 100 parts by weight of a random copolymer with propylene having an ethylene content of 2.3% by weight (Tokuyama Soda MpN5i), 5 parts by weight of anhydrous Itacone e, a radical initiator (Kayahexa A D
-4D C) 0.5M parts, Tris(2,4-di-
0.1 part by weight of t-butylphenyl) phosphite, 0.1 part by weight of calcium stearate, and each additive shown in Table 3 were blended in predetermined proportions and mixed in a super mixer. Next, this was melt-kneaded using a 40% vented extruder to obtain the desired pellets. Hereinafter, the peel strength was measured in the same manner as in Example 1. These results are also listed in Table 3.

In addition, after extracting these pellets with acetone to remove unreacted itaconic anhydride, the amount of grafted itaconic anhydride was measured by measuring an infrared spectrum, and it was found to be 1.1% by weight.

Table 3 Note) Kiguchi shows a comparative example.

Example 4 Each additive shown in Table 4 was added to 100 parts by weight of polypropylene Polycure 1001 (manufactured by Reichhold) grafted with 6% by weight of acrylic acid at a predetermined ratio and mixed in 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. These results are also listed in Table 4.

Table 4 Example 5 Polyethylene (manufactured by Toyo Soda Kogyo Co., Ltd., PE-1000) 1
00 parts by weight, 3 parts by weight of maleic anhydride, radical initiator (trade name Percadox 14) (Kayaku Nouri Co., Ltd.'s Ri0
．． 5 parts by weight.

0.1 part by weight of 2.6-tert-butyl-4-methylphenol and 0.1 part by weight of calcium stearate were melt-kneaded in a tumbler blender in the same manner as in Example 1, followed by heat treatment. The amount of maleic anhydride grafted in this pellet was 1.5%.

Next, 30 parts by weight of the above pellets, polyethylene (PE
-1000) 70 parts by weight, 0.1 part by weight of tris(2,4-di-t-butylphenyl) phosphite, 1 part by weight of calcium stearate Q, and each additive number shown in Table 5 in the prescribed proportions. The mixture was blended using a tumbler blender. After obtaining the desired pellets in the same manner as in Example 1, the peel strength was further measured. These results are also listed in Table 5.

Table 5 patent author Tokuyama Soda Co., Ltd.

Claims (5)

[Claims] (1) 0.01-2.0 parts by weight of a metal salt of benzoic acid or its derivatives per 100 parts by weight of a polyolefin resin grafted with 0.01-10% by weight of unsaturated carboxylic acids.
An adhesive polyolefin resin composition containing parts by weight. (2) The adhesive polyolefin resin composition according to claim 1, wherein the unsaturated carboxylic acid is maleic acid. (3) The adhesive polyolefin resin composition according to claim 1, wherein the unsaturated carboxylic acid is acrylic acid. (4) The adhesive polyolefin resin composition according to claim 1, wherein the polyolefin resin is polypropylene. (5) The adhesive polyolefin resin composition according to claim 1, wherein the metal salt of benzoic acid or its derivative is aluminum pt-butylbenzoate.