JPH0456846B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a modified olefinic polymer and a method for producing the same. "Modified olefinic polymer" refers to an olefinic polymer containing several free carboxylic acid groups along the chain, which confer properties typical of olefinic polymers, particularly high adhesion to metals. say. Polypropylene with predominantly crystalline polymers prepared using stereospecific catalysts and the like;
Similarly, random and block type ethylene-propylene crystalline copolymers consisting primarily of propylene have been found to be suitable as modified polyolefins according to the invention. Technological and patent documents describe methods for grafting unsaturated acids onto polypropylene, methods by forming free radicals with radiation (beta rays, gamma rays, electric discharges, electron beams), oxygen, ozone, peroxides, azo compounds, etc. A method using a free radical reaction initiator, a method using high temperature heat treatment in a gas phase, etc. are described. U.S. Pat. No. 3,987,122 describes a grafting reaction of an unsaturated acid onto an olefinic polymer by a method in which an organic peroxide is allowed to act on a mixture of the olefinic polymer and an unsaturated acid at high temperatures. . The resulting product has adhesion properties to metals and is suitable as a hot melt. According to this method, organic peroxides with a half-life of 10 hours at high temperatures of 80°C or higher, such as dicumyl peroxide, butyl tertiary peroxide benzoate, 2,5-dimethyl-2,5-
di-tert-butyl-peroxy-3-hexyne, a,
Using a-bis(tert-butyl-peroxy)-diisopropyl-benzene or the like as an initiator, direct grafting is achieved in the extrusion process of the mixed olefinic polymer with an unsaturated acid. However, now, granular polymers are put into a rapid-mixing powder mixer, and the maximum and minimum temperatures are 10 to 100 minutes, respectively, in a temperature range of 70 to 120℃, and the 100℃ half-life time is 30 minutes or less. The olefinic polymer is treated with an organic peroxide, which mainly consists of a pre-peroxidation treatment of the olefinic polymer.
A method of grafting onto the same copolymer has now been discovered, which is the object of the present invention. Subsequently, the peroxidized olefinic polymer is mixed with an unsaturated carboxylic acid and an organic peroxide having a half-life time of 200°C≦30 seconds at a temperature of 220°C or lower. The grafting reaction of unsaturated acids onto preperoxidized poly-olefin chains is carried out using the mixture obtained above.
This is achieved by heating to a temperature of around 180 to 220 degrees Celsius for a few seconds. The second type of peroxide used in the grafting reaction step may be added to the starting polymer together with the first type of peroxide. This embodiment is advantageous in practice, since the incorporation of the second type of peroxide into the polymeric material takes place more homogeneously and completely. Examples of the peroxide used in the first step include lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, and decanoyl peroxide. The amount of peroxide used ranges from 0.1 to 0.5 g per 100 g of polymer. The half-life time of the peroxide used in the first step is shown in the table below.

[Table] Peroxides introduced in the second step and subsequently used for grafting unsaturated acids include, for example:
2,5-dimethyl-2,5-bis(tert-butyl-
Useful are tertiary-butyl peroxide, dicumyl peroxide, di-tert-butyl benzoate peroxide, and the like. The amount of peroxide used is 100g of olefin polymer.
It ranges from 0.11 to 0.1 g per serving. The half-life time of the peroxide used in the second step is shown in the table below.

[Table] Examples of unsaturated acids grafted onto polyolefin chains include acrylic acid, maleic acid, fumaric acid, itaconic acid, methacrylic acid, and derivatives of these acids. Acrylic acid and methacrylic acid are particularly suitable. The amount of unsaturated acid used is the amount generally used in the production of modified olefin polymers by the graft reaction of the above-mentioned acids.
That is, the amount used is 0.1 to 10 g per 100 g of the olefinic polymer. The grafting reaction step involves, in particular, charging the product mixture of preperoxidized olefinic polymer with an unsaturated acid and an organic peroxide into an extrusion granulator operating at the temperatures and polymer residence times described above. conduct. Unlike previous methods in which an olefinic polymer and an unsaturated acid were reacted in the presence of a peroxide in a single step, the method of the present invention relies on the organic peroxide selected for the method. It is characterized by a pre-peroxidation step of the olefinic polymer using an oxide and a subsequent grafting step in the presence of the peroxide selected for the process. Due to the operational features of the method according to the invention,
An olefinic graft polymer is obtained which has improved properties, in particular high adhesion to metals, and high peel test values according to American Society for Testing and Materials Standard A STM D-903/65. The peel strength of a sample composed of a metal plate and modified polyolefin was measured after being immersed in water at 25°C for 30 days. That is, the peel test value of the modified polyolefin according to the present invention remained unchanged. The improved properties of this product can be attributed to the specific conditions under which the unsaturated acid grafting reaction is achieved. Depending on the grafting reaction conditions, the homogeneous polymerization reaction of the unsaturated acid is kept to a minimum, and the grafting reaction of the same acid is carried out at multiple locations on the polyolefin chain, resulting in a polyolefin with only a few acid side chains and an extremely short chain. A structure like this is obtained. In carrying out the present invention, a wide range of changes or modifications may be made to the details of the present invention, but such changes or modifications will not depart from the original spirit or scope of the present invention. The following examples are illustrative of the invention, but are not intended to limit the scope of the invention. Example 1 Into a high-speed mixer made of stainless steel and having an internal volume of 10, 2 kg of flaky polypropylene, 6 g of lauroyl peroxide, and 1 g of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane were introduced. The polypropylene had an intrinsic viscosity of 2.28 dl/g and a heptane extraction residue of 97.9%. Mix at 110°C for 1 hour. After mixing treatment, the same polymer is -
OOH=0.07%±0.01% (weight), intrinsic viscosity 1.5dl/
g. The temperature was lowered to 30°C, and 40 g of acrylic acid was introduced. After mixing at 30 °C for 20 min, the polymer was removed and heated to 45 °C.
It was granulated at 200°C using a mmφ 1-screw extruder. Residence time in the extruder was 30 seconds. The resulting granulated product is −COOH=1.2
The percentage by weight is shown, which was equal to 1.92% acrylic acid. Starting from two aluminum plates (100 microns thick), prepared in a compressor at 200℃ for 5 minutes.
The plate with the graft polymer in the middle showed a peel strength (peel test) of 2 Kg/cm±0.2. Peel test measurements remained unchanged after immersion in water for 30 days at 25°C. Example 2 Into a high-speed mixer made of stainless steel and having an internal volume of 10, 2 kg of propylene-ethylene copolymer, 6 g of lauroyl peroxide, and 1 g of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-hexane were introduced. . The propylene-ethylene random copolymer exhibited: intrinsic viscosity 3.6 dl/g ethylene content 5.0% by weight. The above copolymer was mixed at 90°C for 1 hour. After mixing, the polymer showed -OOH=0.04% by weight. The temperature was lowered to 30℃ and 4.0g of acrylic acid was introduced. 30℃,
Mix for 20 minutes, release the polymer, and granulate at 200℃ using a 45mmφ single screw extruder. The resulting granulated molded product showed -COOH = 1.0% by weight, corresponding to 1.6% acrylic acid. Starting from two aluminum plates (thickness 100μ), a plate prepared in a compressor at 200°C for 5 minutes with a graft polymer placed in the middle showed a peel strength (peel test) of 2 Kg/cm ± 0.2. Ta. The peel test values did not change after being immersed in water at 25°C for 30 days. Example 3 Into a high-speed type mixing machine made of stainless steel and having an internal volume of 10, 2 kg of flaky polypropylene, 6 g of lauroyl peroxide, and 1 g of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane were introduced. The above polypropylene exhibited: Intrinsic viscosity 2.28 dl/g Heptane extraction residue 97.9%. Mix for 1 hour at 110℃. After mixing treatment, the same polymer is -
OOH=0.07%±0.01, [η]=1.5. The temperature was brought to 30° C. and 80 g of acrylic acid was introduced. After mixing for 20 minutes at 30 °C, the polymer was released and
It was granulated using a 45mmφ single screw extruder. The granulated molded product corresponds to 3.5% of acrylic acid.
It showed a COOH value of 2.2% by weight. Starting from two aluminum plates (thickness 100μ), the plate prepared in a compressor at 200°C for 5 minutes and with a graft polymer in the middle showed a peel strength (peel test) of 2 Kg/cm ± 0.2. . Although it was immersed in water at 25°C for 30 days, the peel test values did not change after that. Example 4 Into a fast-running mixer made of stainless steel and having an internal volume of 10, the following were introduced: 2 kg of flaky polypropylene, 6 g of lauroyl peroxide, and 1 g of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane. The above polypropylene exhibited: Intrinsic viscosity 2.28 dl/g Heptane extraction residue 97.9%. Mix it for 1 hour at 110°C. After mixing process,
The same polymer had -OOH=0.07%±0.01 and [η]=1.5. The temperature is lowered to 30° C. and 10 g of acrylic acid is introduced. Mix at 30 °C for 20 min to release the polymer.
Pelletize and mold at 200℃ using a 45mmφ single screw extruder. The resulting granulated molded product is made of acrylic acid.
0.48% equivalent value - COOH = 0.3% by weight. Starting from an aluminum plate (100μ thick)
Peel strength (peel test) of molded plate with graft polymer inserted in it prepared in a compressor at 200℃ for 5 minutes
It showed 1.6Kg/cm±0.2. After immersion in water at 25°C for 30 days, the peel test values remained unchanged. Example 5 Into a high-speed mixing machine made of stainless steel and having an inner volume of 10 mm, 2 kg of polypropylene flakes, 6 g of benzoyl peroxide, and 1 g of 2,5-dimethyl-2,5-bis(tert-butylperoxy)-hexane are placed. The above polypropylene exhibited: Intrinsic viscosity 2.28 dl/g Heptane extraction residue 97.9%. Mix for 1 hour at 110°C. After the mixing treatment, the same polymer exhibited -OOH=0.072 and intrinsic viscosity of 1.6 dl/g. The temperature was lowered to 30°C and 40g of acrylic acid was introduced. Mix at 30℃ for 20 minutes to release the polymer, 45mmφ
Granulate and mold at 200℃ using a single screw extruder. The granulated molded product corresponds to 2% of acrylic acid.
It showed a COOH value of 1.25% by weight. Starting from an aluminum plate (100μ thick),
A molded plate prepared in a compressor at 200°C for 5 minutes and containing a graft polymer in the middle showed a peel strength (peel test) of 2.2 kg/cm. Even after 30 days of immersion in 25°C water, the peel test values remained unchanged. Example 6 Into a fast-running mixer made of stainless steel and having an internal volume of 10: 2 kg of polypropylene flakes, 6 g of lauroyl peroxide, and 0.6 g of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-hexane are introduced. The above polypropylene exhibited: Intrinsic viscosity 2.28 dl/g Heptane extraction residue 97.9%. The mixture was mixed at 110°C for 1 hour, and the polymer after the mixing treatment showed -OOH=0.07%±0.01% and [η]1.5. The temperature is lowered to 30° C. and 40 g of acrylic acid are introduced. Mix at 30℃ for 20 minutes, release the polymer, and perform granulation molding at 200℃ using a 45mmφ single screw extruder. The granulated molded product contains - equivalent to 1.6% acrylic acid.
It showed a COOH value of 1.0% by weight. The molded plate was prepared using two aluminum plates (thickness 100μ) at 200℃ for 5 minutes using a compressor, and the graft polymer was inserted into both plates. Value) 1.4Kg/cm±0.2. After 30 days of immersion in 25°C water, the measured values of the peel test remained unchanged. Example 7 Into a high-speed mixing machine made of stainless steel and having an internal volume of 10, 2 kg of flaky polypropylene, 6 g of lauroyl peroxide, and 1 g of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-hexane were introduced. The above polypropylene exhibited: Intrinsic viscosity 2.28 dl/g Heptane extraction residue 97.9%. This was mixed at 110°C for 1 hour, and the -OOH value of the polymer after the mixing treatment was 0.07%±0.01, and the [η] value was 1.5. The temperature is lowered to 30°C and 10 g of acrylic acid is introduced. Mixing was carried out at 30° C. for 20 minutes, the polymer was released, and then granulation was carried out at 190° C. in a 45 mmφ single screw extruder. The resulting granulated molded product exhibited a -COOH value of 0.37% by weight, corresponding to 0.59% acrylic acid. A molded plate prepared using two aluminum plates (thickness 100μ) at 200℃ for 5 minutes in a compressor, with a graft polymer inserted between the two plates, has a peel strength (measured value of peel test) of 1.7 kg. /cm±0.2. No change was observed in the peel test values after immersion in water at 25°C for 30 days. Example 8 Into a high-speed mixing machine made of stainless steel and having an internal volume of 10, 2 kg of flaky polypropylene, 6 g of lauroyl peroxide, and 1 g of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-hexane were introduced. The above polypropylene had an intrinsic viscosity of 2.28 dl/g and a heptane extraction residue of 97.9%. Mix it for 1 hour at 110°C. After the mixing treatment, the -OOH value was 0.07%±0.01, and the [η] value was 1.5. The temperature was lowered to 30°C, and 10 g of acrylic acid was introduced. Mix at 30℃ for 20 minutes to release the polymer, 45mmφ
Granulation is carried out at 220°C in a single screw extruder. The obtained granulated molded product showed a -COOH value of 0.60% by weight, which corresponds to 0.96% of acrylic acid. The peel strength (measured value in peel test) of a molded plate made from two aluminum plates (thickness 100μ) in a compressor at 200℃ for 5 minutes with graft polymer inserted in both plates is 1.8 Kg/cm. It was ±0.2. There was no change in peel test measurements after immersion in water at 25°C for 30 days. Comparative Example 1 Into a low-speed operation mixer made of stainless steel and having an internal volume of 30 mm, 2 kg of flaky polypropylene, 6 g of lauroyl peroxide, and 1 g of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-hexane were introduced. The above polypropylene had an intrinsic viscosity of 2.28 dl/g and a heptane extraction residue of 97.9%. Mix this at 30℃ for 1 hour. Add 40 g of acrylic acid to the mixed polymer. Mix for 20 minutes at 30°C, release the polymer, and granulate at 200°C in a 45mmφ single screw extruder. The obtained granulated molded product showed a -COOH value of 0.9% by weight, which is equivalent to 1.44% of acrylic acid. The peel strength of the molded plate with the graft polymer inserted, which was prepared by preparing two aluminum plates (thickness 100μ) at 200℃ for 5 minutes in a compressor (measured value of peel test)
It showed 0.0Kg/cm. Even after immersion in water at 25°C for 30 days, the peel test measurements remained unchanged. Comparative Example 2 Into a high-speed operation mixer made of stainless steel and having an internal volume of 10, 2 kg of flaky polypropylene and 6 g of lauroyl peroxide were introduced. The above polypropylene had an intrinsic viscosity of 2.28 dl/g and a heptane extraction residue of 97.9%. Mix this at 110℃ for 10 hours. The -OOH value of the polymer after the mixing treatment was 0.07%±0.01, and the [η] value was 1.5. Lower the temperature to 30°C and add 40g of acrylic acid. Mix at 30°C for 20 minutes, release the polymer, and granulate at 200°C in a 45 mmφ single screw extruder. The granulated molded product corresponds to 0.96% of acrylic acid.
It showed a COOH value of 0.6% by weight. A molded plate made of two aluminum plates (thickness 100μ) prepared in a compressor at 200℃ for 5 minutes and a graft polymer inserted between the two plates has a peel strength (peeling test measured value) of 0.4 Kg/cm± It showed 0.2. Even after immersion in water at 25°C for 30 days, the peel test measurements remained unchanged. Comparative Example 3 Into a high-speed operation mixer made of stainless steel and having an internal volume of 10, 2 kg of flaky polypropylene and 2 g of 2,5-dimethyl-2,5-bis(tert-butyl peroxide)-hexane were introduced. The above polypropylene had an intrinsic viscosity of 2.28 dl/g and a heptane extraction residue of 97.9%. Mix for 1 hour at 110℃. Polymer after mixing treatment
The OOH value was 0.02% by weight. The temperature is lowered to 30° C. and 40 g of acrylic acid are introduced. After mixing for 20 minutes at 30°C, the polymer was released and
Granulate and mold at 200℃ in a 45mmφ single screw extruder. The granulated molded product corresponds to 1.6% of acrylic acid.
It showed a COOH value of 1.0% by weight. Using two aluminum plates (thickness 100μ),
A molded plate prepared at 200° C. for 5 minutes in a compressor with the graft polymer interposed between the plates had a peel strength (measured value in a peel test) of 0.5 Kg/cm±0.2. Even after 30 days of immersion in water at 25°C, the measured values of the peel test remained unchanged.

Claims (1)

[Scope of Claims] 1. A method for producing a modified olefin-based polymer which is composed of an unsaturated carboxylic acid grafted olefin-based polymer and has high adhesion to metals, using an organic peroxide whose half-life time at 100°C is <30 minutes. , 70 to 120
A preliminary step of peroxidation treatment of the olefinic polymer at ℃, followed by mixing with an unsaturated carboxylic acid and a grafting reaction with the unsaturated carboxylic acid in the absence of a solvent at a temperature range of 180 to 220℃. in
A method for producing a modified olefin polymer comprising carrying out the process in the presence of an organic peroxide with a half-life time of 200°C of 30 seconds. 2. The grafting reaction is carried out by passing the olefinic polymer-organic peroxide mixture through a mixer operated at 180 to 220°C, and the residence time of the mixture in the mixer is 20 to 30 seconds. The manufacturing method according to item 1. 3. The method according to claim 1 or 2, wherein the preliminary step of peroxidation treatment of the olefin polymer is carried out by mixing the olefin polymer with peroxide in a powder mixer for 10 to 100 minutes. Production method. 4. The organic peroxide used in the graft reaction step is added to the starting olefinic polymer together with the peroxide used in the peroxidation preliminary step. Production method. 5 The peroxides used in the preliminary peroxidation step are lauroyl peroxide, benzoyl peroxide, and p-peroxide.
Claim 1 selected from chlorobenzoyl, decanoyl peroxide, and other similar compounds;
The manufacturing method according to item 2 or 3. 6 The peroxides used in the grafting reaction step are tert-butyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-hexane, dicumyl peroxide, di-tert-butyl benzoate peroxide. , and other similar compounds. 7. A patent claim that uses as the starting olefinic polymer a predominantly isotact polymeric crystalline polypropylene prepared by the use of a stereospecific catalyst, or a predominantly propylene-containing random or block propylene-ethylene crystalline copolymer. The manufacturing method according to item 1.