JPS603097B2 - Polyolefin composition with excellent adhesive properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyolefin composition with excellent adhesive properties.

More specifically, the present invention relates to a composition with improved adhesive properties of a modified polyolefin obtained by graft polymerizing an unsaturated carboxylic acid or its anhydride to a polyolefin. While polyolefin has excellent properties such as cold resistance, weather resistance, mechanical properties, and moldability, its molecular structure is nonpolar and highly crystalline, making it difficult to bond with dissimilar materials such as synthetic resins, metals, and paper. inferior to sex.

These drawbacks have been significantly improved by graft polymerizing polyolefin with unsaturated carboxylic acid or its anhydride, and it has become extremely important as a hot-melt adhesive. However, since the melting point of this modified polyolefin is not much different from that of the basic resin, it cannot be used below the melting point of the poly-IJ olefin. Therefore, for example, modified polyolefins cannot be used as adhesives between vinyl chloride and steel pipes, steel plates, and aluminum, between polypropylene, and between biaxially oriented films and cellophane because the adherends are deformed by heat. Furthermore, modified polyolefins produced by the melt-kneading method could not be used in film adhesives due to gel-like substances and off-odor caused by unreacted monomers. On the other hand, hot melt adhesives whose main component is ethylene monoacetate pinyl copolymer, which has a lower melting point than polyolefin, contain rosin, modified rosin, aromatic petroleum resin, etc. as tackifiers to provide adhesive strength. There are many things.

However, with this method, there is a limit to the adhesive strength and strong adhesive strength cannot be obtained, and it is necessary to increase the amount of tackifier blended in order to improve the twilling strength. In this case, the film formability of the ethylene monovinyl acetate copolymer is lost. Taking the above into consideration, the present inventors conducted intensive studies to improve the drawbacks of modified polyolefins, and as a result, they discovered a polyolefin composition useful as a film adhesive with adhesive properties at low temperatures, and achieved the present invention. . That is, the gist of the present invention is as follows: [a1] Vinyl acetate content relative to parts by weight of modified polyolefin 10 obtained by graft polymerizing 0.01 to 0.5% by weight of an unsaturated carboxylic acid or its anhydride to polyolefin; 10 to 4% by weight of ethylene-vinyl acetate copolymer and 50 to 20 parts by weight of {c' aliphatic petroleum resin
-5 parts by weight of the polyolefin composition with excellent adhesive properties.

To explain the present invention in detail below, a modified polyolefin (hereinafter simply referred to as "modified polyolefin") is a modified polyolefin obtained by graft polymerizing 0.01 to 0.5% by weight of an unsaturated carboxylic acid or its anhydride to the polyolefin used in the present invention. That's what it means.

) is a polyolefin in which a monomer or polymer of an unsaturated carboxylic acid or its anhydride is chemically bonded, and the amount of bonding is 0 to the polyolefin in terms of the monomer of the unsaturated carboxylic acid or its anhydride. .01~0
．． 5% by weight. Binding amount is 0.01
If it is less than 0.5% by weight, the saddle adhesion strength will be low, and if it is more than 0.5% by weight, the smelly gel will increase, which is not preferable. Within this range, preferably 0.03 to 0.3% by weight, most preferably 0.
．． 0.03 to 0.0 mass% by weight. The polyolefins used include high density polyethylene, low density polyethylene, medium density polyethylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, polypropylene,
Examples include propylene-butene-1 copolymer, polybutene-1, poly-4-methylbentene-1, and the like.

Preferred polyolefins vary depending on the mode in which the composition of the present invention is used, and for example, when the composition of the present invention is used as an adhesive between polyvinyl chloride and metal, the density is preferably 0.910 to 0.910. Low-density polyethylene or elastomeric ethylene-propylene copolymer with 5 spots is preferable.
On the other hand, as the unsaturated carboxylic acid or its anhydride to be graft-polymerized, acrylic acid, maleic acid, itaconic acid, fumaric acid, /imic acid, citraconic acid, or anhydride thereof is used.

In particular, it is preferable to use maleic anhydride. Thus, the modified polyolefin of the present invention can be produced by adding an unsaturated carboxylic acid or its anhydride to a polyolefin and causing a graft polymerization reaction according to a conventional method. The process for causing the graft polymerization reaction may be a solution method or a slurry method, but a melt-concentration method is preferable in terms of cost. In the case of fused crosstalk method,
0.01 to 0.5% by weight of an unsaturated carboxylic acid or its anhydride and 0.05% by weight or less, preferably 0.001 to 0.05% by weight of an organic peroxide are blended into a polyolefin, and 12% by weight is added. Melting and kneading at a temperature of C to 300C is advantageous because a modified polyolefin with high grafting efficiency, no fish eyes or gel-like substances, good color, and no odor can be obtained. To further explain the above melt-kneading method, if the amount of unsaturated carboxylic acid or its anhydride added to the polyolefin is less than 0.01% by weight, the adhesive strength will be low;
If it exceeds 5% by weight, it is not preferable because it produces a smelly gel-like substance.

Within the above range, 0.03 to 0. Marugame weight % is preferable, and 0.03 to 0.09 weight % is most preferable. If the amount of organic peroxide used is 0.05% by weight or more, gel-like substances and fish eyes in the film will increase, and the molecular weight will decrease, which is not preferable. The lower limit is not particularly limited and may be 0 for high-density polyethylene, but if it is less than 0.001% by weight, the grafting efficiency will decrease and problems such as a decrease in adhesive strength or the odor of unreacted monomers will likely occur, so 0.001
It is preferable that it is at least % by weight. Examples of organic peroxides include benzoyl/di-oxide, acetyl peroxide, di-t-butyl peroxide, di-t-butyl peroxide, t-butyl peroxylaurate, dicumyl/gu oxide, and Q.Q'-bis-t. -butylperoxy-p-diisoprobenzene, 2,5-dimethyl-2,5-d-t-butylperoxyhexane, t-butylperoxybenzoate, n-butyl-4,4-bis-t-butylperoxyvalate , octa/yl peroxide, 2,5 dimethyl 2,5-di(pesozoylperoxy)hexane, vinyltris(t-butylperoxy)silane, vinyltris(cumylperoxy)
Examples include silane, methylvinyldi(t-butylperoxy)silane, and methylpinyl(cumylperoxy)silane. The melt-kneading method involves dry-blending polyolefin powder or pellets with an unsaturated carboxylic acid or its anhydride and, if necessary, an organic peroxide in a predetermined mixing ratio using a Henschel mixer or the like, or by dry-blending polyolefin powder or pellets with an unsaturated carboxylic acid or its anhydride and, if necessary, an organic peroxide in a Henschel mixer. Dissolve a saturated carboxylic acid or its anhydride and an organic peroxide if necessary, and apply it to a polyolefin powder or pellet,
Blend further using a Henschel mixer. In the present invention, the unsaturated carboxylic acid or its trout hydrate as a graft monomer is used in a smaller amount than in the conventional method, so when kneading it with the polyolefin, an organic solvent is used as described above to uniformly mix it with the polyolefin. It is preferable to mix them. Such organic solvents include acetone, methyl ethyl ketone, cyclohexanone, and the like. The blended polyolefin powder or pellet is put into a moat machine, such as a Banbury mixer, a double screw mixer, an extruder, etc. whose system is purged with nitrogen gas, and the temperature is 120.
Melt and mix wires at ℃~300℃ for 0.1~30 minutes. Melt kneading state (1/sec to Shearra) x time s
ec), this value is 1500 to 15
0000 is preferred. If this value is less than 1,500, the polyolefin powder or pellet containing the unsaturated carboxylic acid or its anhydride and the organic peroxide will not be uniformly kneaded*, and the graft reaction will not proceed well. On the other hand, if it is larger than 150,000, the polymer tends to deteriorate and is not practical. In order to control the melt-kneading state, the mixing temperature, the rotation speed of the mixer, the preparation schedule, etc. may be appropriately selected. Among these, the kneading temperature is particularly important. 1
Below 20℃, the grafting reaction rate is too slow;
This is because the thermal decomposition of the polymer becomes significant if the temperature exceeds this value.

Among these, 18 to 250°C is preferable. 10 to 4% by weight of ethylene-containing groups used in the invention
Vinyl acetate copolymer (hereinafter simply referred to as "ethylene-vinyl acetate copolymer").

) is obtained by radical copolymerization under high pressure, and those having a melt index (according to ASTM D-12) of 0.1 to 400 are usually used. If a polymer containing vinyl acetate is 4% or more, the adhesion of the blended composition with the modified polyolefin will be greatly reduced, and when molded into a film, blocking between the films will be large, resulting in poor workability. It is bad and cannot be used. Furthermore, if a vinyl acetate content is less than 1% by weight, it is not preferable because the adhesion temperature of the blend composition will be lowered less. Commercially available products include Ebaflex (Shohori,
(manufactured by Mitsui Petrochemical Co., Ltd.), Cucaloneva (trademark, manufactured by Mitsubishi Oil Industry Co., Ltd.), Ultrasen (trademark, manufactured by Toyo Soda Co., Ltd.), and Evatate (trademark, manufactured by Sumitomo Chemical Company). Next, the aliphatic petroleum resin used in the present invention is a carbonized thermoplastic resin that is produced by polymerizing reactive olefins and/or diolefins obtained by decomposing petroleum at high temperatures, and is substantially free of polymerized aromatic substances. It is a hydrogen resin, and also includes hydrides thereof.

As reactive olefins and diolefins, widely used products such as bentene, isobrene, and piberylene from petroleum naphtha cracking are mainly used. Such aliphatic petroleum resins usually have a molecular weight of 600 to 2000 and a ring and ball softening point (A
STMD-36) is 50°C to 140°C, and the iodine value is 30 to 150. Commercially available products include Escoret (trademark, manufactured by Esso Chemical Co., Ltd.), Hiret (trademark, manufactured by Mitsui Petrochemical Co., Ltd.), and Clayton (trademark, manufactured by Mitsui Petrochemical Co., Ltd.). Trademark, Nippon Zeon Co., Ltd.)
, Picovert (trademark, manufactured by Pico), and the like. Therefore, the aliphatic petroleum resin has a role as a tackifier in the composition of the present invention, maintains the adhesive properties of the composition of the present invention, and imparts functions such as improving hot tack properties and shortening adhesive time. On the other hand, other tackifiers are not necessarily effective; for example, when aromatic petroleum resins are used, compatibility is poor and adhesion, hot-tack properties, and film processability are reduced, and when waxes are used, The compatibility is extremely good, but the adhesive strength is low. The blending ratio of each component in the present invention is 50 to 20 parts by weight of the ethylene monoacetate pinyl copolymer and 5 to 5 parts by weight of the aliphatic petroleum resin to 100 parts by weight of the modified polyolefin. If the amount of the ethylene monovinyl acetate copolymer is less than 5 parts by weight, the adhesive performance in a low temperature range will decrease. If it exceeds 20 parts by weight, the adhesive strength of the modified polyolefin will be significantly reduced, which is not preferable.

Similarly, if the amount of aliphatic petroleum resin is less than 5 parts by weight, the adhesion performance in a low-temperature castle will decrease, and if the amount exceeds the 5th pupil, the adhesive strength of the modified polyolefin will decrease significantly. Preferred ranges are 60 to 17 parts by weight of the ethylene-vinyl acetate copolymer and 10 to 3 parts by weight of the aliphatic petroleum resin. The method for preparing the composition of the present invention is to mix modified polyolefin, ethylene monovinyl acetate copolymer, and aliphatic petroleum resin using a hexhell mixer, V-shaped blender, etc., and then to form a pellet using an extruder, double screw mixer, etc. or a method in which the modified polyolefin, ethylene monovinyl acetate copolymer, and aliphatic petroleum resin are blended in a Banbury mixer or a single roll mixer, and then cut into pellets by a sheet cutter.

Thus, the composition of the present invention can be used as an adhesive as described above.

For example, the composition of the present invention can be melt-extruded into a film or sheet using an extruder and laminated onto an adherend, or it can be sandwiched between adherends and then pressure-bonded. In particular, it can be used for adhesion of steel pipes and polyvinyl chloride pipes, adhesion of steel plates and polyvinyl chloride plates, adhesion of aluminum plates and polyvinyl chloride plates, and double-stretched film laminating agents.
When the composition of the present invention is used as an adhesive, it has the advantage of having good adhesive action even in a low temperature range from the melting point of the modified polyolefin to 4000 psi. The present invention will be explained below with reference to Examples and Comparative Examples.

In addition, "MI" in the examples is ASTM D-12 total 57
Melt index by T, “MFI” is ASTM
Melt flow index with D-12 spots 70 is shown.

Examples 1 to 5 and Comparative Examples 1 to 5 Low density polyethylene [Novatec-L (manufactured by Mitsubishi Chemical Corporation,
Trademark) F-150, skin = 2.0] Q dissolved in 100 parts by weight and a small amount of acetone.

0.025 parts by weight of Q'-t-butylperoxy-p-diisopropylbenzene, 0.025 parts by weight of maleic anhydride. Female weight part. Blend in a Henschel mixer. This mixed pellet was extruded into a pellet by using an extruder with an inner diameter of 40/m and L/D=28 at 23:0. After pulverizing a portion of this pellet, unreacted maleic anhydride was extracted with acetone using a Soxhlet extractor for 1 hour, and then maleic anhydride was quantified using infrared spectroscopy.
75% by weight of maleic anhydride was graft polymerized.
The thus obtained maleic anhydride-modified low-density polyethylene pellets, ethylene-vinyl acetate copolymers with different amounts of vinyl acetate, and aliphatic petroleum resin as a tackifier were mixed in a Banbury mixer in the proportions shown in Table 1. - It was blended at -. This blend was ground. A brofilm die was attached to a small extruder having a diameter of 20 mm and a L/D of 21, and the blend was charged therein to produce an blown film having a thickness of 0.1 mm/skin at 180°C. Use this film as an adhesive to attach a galvanized steel plate (25 skin width, 2 shelf thickness) and a hard polyvinyl chloride board [Nica Vinyl SG-1100 (trademark), manufactured by Ryoichi Co., Ltd., 25 side width, 3 rib thickness]. A piece for measuring adhesive strength was prepared by inserting it into several pieces according to JISK Total 50, and the adhesive strength was measured. The bonding conditions were 105° C., pressure 0.5k9/ground gauge, and 2 minutes in a hot air dryer without child heat. Under these conditions, the temperature of the bonded portion of the polyvinyl chloride plate was 1000 psi at the final time, and there was no deformation of the polyvinyl chloride plate. The results are shown in Table 1. Table 1 *1 Manufactured by Esso Kagakusha (trademark) *2 Manufactured by Nippon Zeon Takugata (trademark) *3 Esso Chemical. Example 6 100 parts by weight of polypropylene powder (MFI = 2.0, homopolymer) and Q.
0.04 part by weight of Q'-bis-t-butylbaroxy-p-diisopropylbenzene and 0.1 part by weight of rice bran maleic acid are blended in a Henschel mixer.

This mixed powder was extruded into a pellet by using an extruder with an inner diameter of 4 mm and L/O = 28 at 23 mm. Example 1
When the amount of maleic anhydride grafted was measured according to
It was 0.05% by weight. This modified polypropylene 10
12 parts by weight of 28% by weight ethylene vinyl acetate copolymer (MI=12) containing vinyl acetate, 12 parts by weight of aliphatic petroleum resin Escorets spheres 00 (same as in Example 1).
) were blended for 3 minutes using a Banbury mixer, and the blend was formed into a sheet with a thickness of 0.2 mm. Bonding conditions are 120℃, 0 pressure in a hot air dryer without child heat.
．． 5k9/enemy gauge, 2 minutes.

Under this condition, there is no deformation of the polyvinyl chloride board. When the rock support strength was measured using the same method as in Example 1, it was found to be 35
It was k9/ground. Examples 7 to 9, Comparative Example 6 Modified in the same manner as in Example 1 except that the amount of organic peroxide and the base of maleic anhydride were changed as shown in Table 2,
Parts by weight of this modified polyolefin 10, parts by weight of ethylene-vinyl acetate copolymer 15 (pinyl acetate content = 2% by weight, skin = 12), and Escolets 5300 (same as in Example 1).

) 2 parts by weight were blended to produce an adhesive film. Table 2 shows the results of measuring the carp cutting adhesive strength using the same method as in Example 1.

In addition, the number of fish eyes was counted during blow film molding, the thickness and width of the film were measured, and the results were converted to the number per unit volume, which is shown in Table 2. Example 10 Modification was performed in the same manner as in Example 1 except that maleic acid was used instead of maleic anhydride, and the obtained modified polyethylene was blended in the same machine as in Example 1.
An adhesive film was produced.

Claims (1)

[Scope of Claims] 1 (a) 100 parts by weight of a modified polyolefin obtained by graft polymerizing 0.01 to 0.5% by weight of an unsaturated carboxylic acid or its anhydride to a polyolefin, (b) a vinyl acetate content of 10 A polyolefin composition with excellent adhesive properties, which contains 50 to 200 parts by weight of an ethylene-vinyl acetate copolymer containing up to 40% by weight and 5 to 50 parts by weight of (C) an aliphatic petroleum resin. 2 Modified polyolefin is 0.01% polyolefin
-0.5% by weight of unsaturated carboxylic acid or its anhydride and 0.001-0.05% by weight of organic peroxide are blended,
The polyolefin composition with excellent adhesive properties according to claim 1, which is obtained by graft polymerization by melt-kneading.