JPS624050B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyolefin composition, and generally relates to a polyolefin composition that has good adhesion to resins, inorganic fillers, glass, metals, and the like. In particular, the present invention relates to a polyolefin composition having good adhesion to both polar resins such as saponified ethylene-vinyl acetate copolymer nylon and polyvinyl alcohol, and polyolefin. Conventionally, polyolefins have good mechanical properties, transparency, moldability, hygiene, etc., but on the other hand,
Since it is non-polar, it has the disadvantage of poor adhesion to polar resins, glass, inorganic fillers, etc. In order to compensate for these drawbacks, attempts have been made to blend polar substances into polyolefins or to graft-react polar monomers. The present inventors have also previously developed an alternating copolymer of 0.5 to 10% by weight of an α-olefin having 2 to 4 carbon atoms and an unsaturated carboxylic acid anhydride and a polyolefin of 99.5 to 99.5% by weight.
We discovered that a polyolefin composition consisting of 90% by weight had excellent adhesion to polar resins and polyolefins, and made a proposal earlier (Japanese Patent Application No. 147654/1984 (Japanese Unexamined Patent Publication No. 147654)). (See publication 072033)). However, the compositions proposed above have disadvantages during the production of alternating copolymers. That is, the alternating copolymer adheres strongly to the inner wall of the container during polymerization, which takes time and effort to remove, the post-treatment is poor, and the dispersibility in polyolefins is poor. As a result of repeated research on this point, the inventors found that
The inventors have discovered that the above-mentioned drawbacks can be overcome by pre-existing a polyolefin during polymerization, and have thus come to provide the present invention. The present invention is a method for producing a modified polyolefin, which comprises polymerizing an α-olefin having 2 to 4 carbon atoms and an unsaturated carboxylic acid anhydride in the presence of the polyolefin. In the present invention, the polyolefin to be present during polymerization includes a homopolymer of polyethylene, polypropylene, polybutene-1, an ethylene-propylene copolymer copolymerized with other α-olefins, such as an ethylene-propylene copolymer copolymerized with a small amount of ethylene, or A polyolefin mixture blended with other polyolefins is used. In particular, it is preferable to use a polymer consisting of the same α-olefin as the α-olefin having 2 to 4 carbon atoms used in the alternating copolymer. These polyolefins are preferably used in powder form, and generally have a particle size of 200 to 1000μ,
Preferably, those having a diameter of 300 to 500μ are used. Further, as the unsaturated carboxylic acid anhydride used in the present invention, any compound that can be copolymerized with an α-olefin having 2 to 4 carbon atoms in the presence of a radical generator catalyst described below can be used without any restriction. Generally has one polymerizable double bond and two
It is a compound in which two carboxyl groups are dehydrated, and includes not only an anhydride of one dicarboxylic acid such as maleic anhydride, but also a monocarboxylic acid with a double bond and a monocarboxylic acid without a double bond. It may also be a mixed carboxylic acid anhydride consisting of.
Examples of unsaturated carboxylic anhydrides include cis-4
-Cyclohexene-1,2-dicarboxylic anhydride (commonly known as tetrahydrophthalic anhydride), endo-bicyclo[2.2.1]-5-heptene-2,3-dicarboxylic anhydride (commonly known as hymic anhydride), endo-
Bicyclo[2.2.1]-1.2.3.4.7.7-hexachloro-
2-heptene-5.6-dicarboxylic anhydride (commonly known as chlordic anhydride), maleic anhydride, itaconic anhydride, succinic anhydride, phthalic anhydride, pyromellitic anhydride, glutaric anhydride, thiodipropionic anhydride, acrylic Examples include acid-acetic anhydride. Among these, dicarboxylic acid anhydrides are preferred, and among these, maleic anhydride is most preferably used. Further, as the radical generator, organic peroxides such as dicumyl peroxide, benzoyl peroxide, and azobisisobutyronitrile are preferably used. Polymerization is generally carried out in a solvent. The solvent used is one in which the copolymer and polyolefin are insoluble, such as benzene, chlorobenzene, heptane, toluene, xylene, and the like. Polymerization conditions vary somewhat depending on the type of radical generator, but the temperature is 40 to 80°C, preferably 55 to 65°C.
℃, and the pressure is 2-20Kg/cm ² , preferably 3-20Kg/cm 2 .
It is 15Kg/ ^cm2 . Polymerization is usually carried out under stirring, generally
It is carried out under 300-700 rpm. In addition, the ratio of polyolefin present during polymerization is 5 to 5 to
20% by weight, preferably 5-10% by weight. The polymerization product is a white powder and smooth.
If it adheres to the inner wall of the polymerization container, it will never get wet.
In addition, separation from the solvent is extremely simple and easy. After filtering, washing and drying, the modified polyolefin of the present invention is obtained. The modified polyolefin obtained by the method of the present invention includes polyolefin [A], an alternating copolymer of an α-olefin having 2 to 4 carbon atoms and an unsaturated carboxylic acid anhydride [B], and [A] containing [B ] consists of a graft copolymer [C] grafted with. [B]
The ratio of component and unsaturated carboxylic acid anhydride contained in component [C] is generally 9:1.
If the content of unsaturated carboxylic acid anhydride in the modified polyolefin is adjusted to 0.35 to 7.0% by weight, good adhesion to both the polar resin and the polyolefin can be achieved. If the content of unsaturated carboxylic acid anhydride is less than 0.35% by weight, the adhesion with polar substances will not be good, and if it exceeds 7.0% by weight, the adhesion with polyolefin will be poor, and the adhesive strength will not be sufficient for practical use. I can't get it. Incidentally, if the composition ratio of the modified polyolefin obtained by adjusting the content of unsaturated carboxylic acid anhydride to 0.35 to 7.0% by weight during polymerization is shown, the [A] component is
90.0 to 99.0% by weight, [B] component is 0.10 to 1.0% by weight, and [C] component is 0.90 to 9.0% by weight. Also,
If the content of unsaturated carboxylic acid anhydride exceeds 7% by weight, modified polyolefin may be blended with polyolefin, but in this case, if the concentration of unsaturated carboxylic acid anhydride is adjusted to 0.35 to 7.0% by weight, As shown in the Examples below, generally the [A] component is 90.5 to 99.5% by weight, and the [B] component is 0.45% by weight.
8.35% by weight, and the [C] component is 0.05 to 1.15% by weight. Methods for obtaining a modified polyolefin having an unsaturated carboxylic acid anhydride content within the above range include a method in which the amount of polyolefin present during polymerization is adjusted, a method in which a polyolefin is blended with the obtained modified polyolefin, and the like. Blending of polyolefins is generally carried out using a tumbler type blender, a Henschel mixer, a Banbury mixer, an extruder, or the like. The modified polyolefin of the present invention has good dispersibility in polyolefins, so blending is easy. Among the modified polyolefins of the present invention, the modified polyolefins with an unsaturated carboxylic acid anhydride content of 0.35 to 7.0% by weight have good adhesive properties with saponified ethylene-vinyl acetate copolymers, polyvinyl alcohol, nylon, polyolefins, etc. shows. Therefore, for example, saponified ethylene-vinyl acetate copolymer/modified polyolefin, polyvinyl alcohol/modified polyolefin, two-layer laminates such as nylon/polyolefin compositions, saponified ethylene-vinyl acetate copolymer/modified polyolefin/polyolefin, It is possible to provide a three-layer laminate of nylon/modified polyolefin/polyolefin, or a five-layer laminate in which another polymer layer is laminated on the three-layer laminate via a modified polyolefin. In these multilayer laminates, it is preferable that the polyolefin used in the composition and the polyolefins in other layers are of the same type. For example, saponified ethylene-vinyl acetate copolymer, polyvinyl alcohol, or nylon/(polypropylene [A] + propylene-maleic anhydride alternating copolymer [B] + graft copolymer in which [B] is grafted onto [A]). [C]) It is like a three-layer laminate made of modified polypropylene/polypropylene. The stretched film obtained from this three-layer laminate has excellent gas barrier properties, oil resistance, water impermeability, and high strength, so it is suitable as a food packaging material. In addition, saponified ethylene-vinyl acetate copolymer, polyvinyl alcohol or nylon/
(Modified polypropylene consisting of polypropylene [A] + propylene-maleic anhydride alternating copolymer [B] + graft copolymer [C] in which [B] is grafted to [A]) / polypropylene / the above polypropylene composition / ethylene The stretched film obtained by laminating five layers of ethylene-propylene random copolymer with a content of 0.3 to 3.0% by weight has excellent gas barrier properties, oil resistance, water impermeability, and heat sealability, making it an excellent material for food packaging. It is suitable as The saponified ethylene-vinyl acetate copolymer has an ethylene content of 20 to 60 mol%, preferably 25 to 50 mol%, and a degree of saponification of 93% or more, preferably 96
% or more is used. Further, as the nylon, nylon 6, nylon 66, nylon 610, nylon 11, nylon 12, etc. are used. As a method for obtaining the above-mentioned multilayer laminate, a lamination method such as an in-die lamination method, an outside-die lamination method, or thermocompression bonding using a press is employed. In the multilayer laminate, each layer may be unstretched, uniaxially stretched, or biaxially stretched, or uniaxially or biaxially stretched after lamination. The modified polyolefin of the present invention may contain a heat-resistant stabilizer, a weather-resistant stabilizer, a lubricant, an antistatic agent, a nucleating agent, a filler, a pigment, a flame retardant, an antiblocking agent, etc. in the amounts commonly used. As mentioned above, in the present invention, polar resin,
Modified polyolefins that have adhesive properties to glass, metals, inorganic fillers, etc. can be easily produced. In particular, the content of unsaturated carboxylic acid anhydrides
The modified polyolefin adjusted to have a content of 0.35 to 7.0% by weight is an ethylene-vinyl acetate copolymer,
It has high adhesion to both polar resins such as nylon and polyolefins. Therefore, it is suitably used as an adhesive between these resins. The present invention will be described below with reference to Examples, but the present invention is not limited thereto. In the Examples, adhesiveness was evaluated using peel strength. Saponified ethylene-vinyl acetate copolymer biaxially stretched film (30μ)/modified polyolefin sheet of the present invention/polyolefin sheet were stacked in the order of 70kg/230℃ for 3 minutes in a hydraulic press.
After press molding under a pressure of cm ² , the two layers, saponified ethylene-vinyl acetate copolymer and modified polyolefin, which are in contact with the surface on which the adhesive peel strength is to be measured, are held in the chuck of an Autograph manufactured by Shimadzu Corporation, and a 20 mm/
The stress detected at a peeling speed of 100 min was measured and was defined as the peel strength. Furthermore, as an evaluation of the superior adhesion of the modified polyolefin of the present invention to glass fibers, ASTM D-
Flexural modulus (×10 ⁴ Kg/cm ² ) based on 790,
In addition, Izot impact strength (Kg-cm/cm) was measured based on ASTM D-256. Example 1 Benzene 1 and polypropylene powder (average particle size 300μ, MFI = 10
g/10 minutes) and dissolved 98 g of maleic anhydride. Then 150ml of propylene monomer
Azobisisobutyronitrile catalyst by injecting 1.26
After adding 5 g of
Polymerized for hours. The polymerization product was in the form of a smooth slurry, and no adhesion to the inner wall of the polymerization container was observed, and it was easy to clean. After washing with ether and drying, a white powdery polymer was obtained with a yield of about 50%. The maleic anhydride content was 28.9% by weight according to infrared absorption spectrum.
Furthermore, when we investigated the composition of the white powdery polymer, we found that it was 58.7% by weight of polypropylene (component A) and 58.7% by weight of propylene-maleic anhydride alternating copolymer (component B).
It was a modified polypropylene consisting of 37.2% by weight and 4.13% by weight of a graft copolymer (component C) grafted with a propylene-maleic anhydride alternating copolymer. This modified polypropylene was kneaded with polypropylene powder in the proportions shown in Table 1 using a Henschel mixer and an extruder to form pellets. Glass fibers (manufactured by Unitika, monofilament) were added to the pellets in an amount of 20% by weight and kneaded using an extruder to form a composition. The flexural modulus and Izot impact strength of this product were as shown in Table 1.

[Table] Example 2 Benzene 1 and polypropylene powder (average particle size 300 μ, MFI = 10
g/10 minutes) and dissolved 15 g of maleic anhydride. Then, 20ml of propylene monomer was injected and 1.0g of azobisisobutyronitrile catalyst was added.
After addition, polymerization was carried out for 5 hours while stirring at a temperature of 60° C., and purified and dried to obtain 110 g of a polymerized product. The yield was about 50% and the maleic anhydride content was 6.5% by weight. Further investigation of the composition of the white polymerization product revealed that it was polypropylene (component A).
Modified polypropylene consisting of 90.9% by weight, 8.2% by weight of a propylene-maleic anhydride alternating copolymer (component B), and 0.9% by weight of a graft copolymer grafted with a propylene-maleic anhydride alternating copolymer (component C). It was hot. Example 3 1 part benzene in an autoclave with an internal volume of 2,
Polybutene-1 (“WITRON0 100” manufactured by Adeka Argus Chemical Co., Ltd., MFI = 0.4) was crushed with a rotary blade type crusher (Rotoplex) to obtain an average particle size of 2000.
After adding 100g of μ powder, maleic anhydride 98
g was dissolved. Then, butene-1 monomer
After injecting 150 ml and adding 2 g of azobisisobutyronitrile (AIBN) catalyst, polymerization was carried out at 60°C for 5 hours while stirring with a stirrer. The polymerization product is a smooth slurry,
No adhesion to the inner wall of the polymerization vessel was observed, and the overheating was easy. After washing with ether and drying, 154 g of a white powdery polymer was obtained. The yield was about 35%. The maleic anhydride content was 22.3% by weight. When we investigated the composition, we found that polybutene-1 (A
Component) 65.0% by weight, butene-1-maleic anhydride alternating copolymer (component B) 31.8% by weight, butene-1
-Maleic anhydride alternating copolymer is polybutene-1
Graft copolymer (C component) grafted to 3.3
It was modified polybutene-1 consisting of % by weight. Example 4 1 part benzene in an autoclave with an internal volume of 2,
Polypropylene powder (average particle size 450μ, MFI=10
After dissolving 25 g of phthalic anhydride, 20 ml of propylene monomer was injected, and 1 g of azobisisobutyronitrile catalyst was added, followed by polymerization at 60 DEG C. with stirring for 5 hours. Example 1
A white powdery polymer was obtained in the same manner as above. The yield is
40%, and the content of phthalic anhydride was 9% by weight. Example 5 The modified polypropylene obtained in Example 1 and the polypropylene powder used in Example 1 were kneaded using a Henschel mixer and an extruder at the blending ratios shown in Table 2 to obtain a polypropylene composition. Using this composition, the peel strength against a polypropylene sheet and a saponified ethylene-vinyl acetate copolymer was measured. The results are also listed in Table 2.

[Table] Example 6 The modified polybutene-1 obtained in Example 3 and the polybutene-1 used in Example 3 were kneaded using a Henschel mixer and an extruder in the proportions shown in Table 3. It was made into a composition. Using this composition, the peel strength against saponified ethylene-vinyl acetate copolymer and polybutene-1 ("WITRON" manufactured by Adeka Argus Chemical Co., Ltd. MFI = 2.0) was measured. The results are also listed in Table 3.

[Table] Example 7 Using the modified polypropylene obtained in Example 4, the peel strength was measured in the same manner as in Example 5. Both the polypropylene sheet and the saponified ethylene-vinyl acetate copolymer film had a peel strength of 1500.
g/10mm width or more. Additionally, 20% by weight of the same glass fiber as used in Example 1 was added to the polypropylene composition used in Example 4.
When the flexural modulus and Izot impact strength of a sample prepared by adding and melt-mixing were measured, the flexural modulus was 5.5×10 ⁴ Kg/cm ² and the Izot impact strength was 14.8.
The value of Kg-cm/cm is shown. Application example 1 Isotactic polypropylene (MFI=2.0
g/10 minutes) using an extruder with a T-die set at 290°C to obtain a sheet with a thickness of 1.5 mm.Then, this sheet was stretched in the longitudinal direction using a roll-type stretching machine with a roll surface temperature of 155°C. A uniaxially stretched sheet with a thickness of 0.3 mm was produced by stretching 5 times. This sheet air temperature 155
axially using an oven-type stretching machine set at °C.
A biaxially stretched polypropylene film having a thickness of 30 μm was obtained by stretching 10 times. Next, the polypropylene composition No. 7 of Example 5 and the saponified ethylene-vinyl acetate copolymer were each put into a coextrusion laminator set at 250°C, and the thickness of the polypropylene composition was placed on the biaxially stretched polypropylene film. The saponified ethylene-vinyl acetate copolymer was extruded and laminated to a thickness of 15μ and a saponified ethylene-vinyl acetate copolymer to obtain a three-layer laminated film of biaxially oriented polypropylene/polypropylene composition/saponified ethylene-vinyl acetate copolymer. Ta. The oxygen permeability of this laminated film is 6c.c./
^m2・24hr・atm, haze was 3.8%. Application example 2 Biaxially oriented polypropylene used in application example 1/
Polypropylene composition/ethylene-vinyl acetate copolymer saponified three-layer laminate film
No. 5 of Example 5 was added to the saponified vinyl acetate copolymer side.
Polypropylene composition of 8 15μ and MFI=8.0
g/10 minutes, 20μ of propylene-ethylene random copolymer with an ethylene content of 2.5% by weight was coextruded and laminated so that the polypropylene composition was on the side of the saponified ethylene-vinyl acetate copolymer to form a biaxially oriented polypropylene/polypropylene composition. A five-layer laminate film of a product/saponified ethylene-vinyl acetate copolymer/polypropylene composition/propylene-ethylene random copolymer was obtained. The oxygen permeability of this film was 7 c.c./m ² ·24 hr · atm, the heat sealing temperature was 133°C, and the haze was 3.2%.

Claims (1)

[Claims] 1. In the presence of polyolefin, the number of carbon atoms is 2 to 4.
1. A method for producing a modified polyolefin, which comprises polymerizing α-olefin and an unsaturated carboxylic acid anhydride. 2. The method according to claim 1, wherein the polyolefin is polypropylene. 3. The method according to claim 1, wherein the polyolefin has a particle size of 300 to 500 microns. 4. The method according to claim 1, wherein the α-olefin is propylene. 5. The method according to claim 1, wherein the unsaturated carboxylic acid anhydride is maleic anhydride. 6. The method according to claim 1, wherein the polyolefin is the same α-olefin polymer as the α-olefin constituting the copolymer.