JPS6239617B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing modified polypropylene that has good adhesion to polar substances such as polyolefins, nylon, polyester, saponified ethylene-vinyl acetate copolymers, glass, and metals. In general, polypropylene has mechanical properties, transparency,
It is used in a wide range of fields because of its excellent moldability and sanitary properties, but it has the disadvantage of poor adhesion to polar substances because it is nonpolar. Various proposals have been made to improve this adhesiveness, one of which is a method of grafting a monomer consisting of an unsaturated carboxylic acid or a derivative thereof to polypropylene. The method of grafting is to react in a solution state (for example,
-15422), a method of reacting in a slurry state (for example, Japanese Patent Publication No. 43-18144), and a method of reacting in a molten state (for example, Japanese Patent Publication No. 43-27421). Among these methods, the method of reacting in a molten state using an extruder is advantageous because it is easy to operate, but unreacted monomer remains in the obtained modified polypropylene, and if there is a large amount of it, it may cause adhesion. There are disadvantages such as insufficient properties and the generation of bubbles during molding of sheets, films, blow molding, etc. Therefore, methods for removing unreacted monomers include the dissolution-reprecipitation method and the solvent extraction method (Japanese Patent Application Laid-Open No. 1983-99193).
However, these methods require the use of large amounts of solvents and poor solvents, are complicated to operate, and have the drawbacks of high costs. The present inventors previously conducted various studies on methods for removing unreacted monomers remaining in modified polypropylene obtained by a melt-kneading method using unsaturated carboxylic acids or derivatives thereof, and found that By heating modified polypropylene at 60°C or higher, unreacted monomers are significantly reduced, foaming phenomenon during sheet, film, blow molding, etc. is suppressed, and adhesion with polar substances is improved. I found it (patent application 1972-170896)
issue). On the other hand, in order to improve the adhesion of modified polypropylene grafted with unsaturated carboxylic acids, a method has been proposed in which atactic polypropylene is added to the modified polypropylene (Japanese Unexamined Patent Application Publication No. 1989-1982).
No. 90346). However, since a large amount of unreacted monomer remains in the modified polypropylene produced by the melt-kneading method, simply adding attic polypropylene to the modified polypropylene will hardly improve the adhesion. On the other hand, since modified polypropylene produced by the melt-kneading method generally has a low grafting rate, a method has been proposed in which a rubber-like substance is added in advance to improve the grafting rate by the melt-kneading reaction to improve adhesion (for example, Publication No. 55-5766, Special Publication No. 55-
No. 18251). However, modified polypropylene produced by the above-mentioned melt-kneading method by adding attic polypropylene in advance also has a large amount of unreacted monomers, so not only does it have insufficient adhesive properties, but it can also be used in films, sheets, and blow molding. It has the disadvantage of generating air bubbles during molding.
Furthermore, even if the modified polypropylene obtained by adding atactic polypropylene in advance and melt-kneading it is sufficiently heated and degassed, if the amount of unsaturated carboxylic acid grafted is not about 0.15 mol% or more, it will not react with polar substances. Adhesion is not sufficient. In the case of modified polypropylene with an unsaturated carboxylic acid grafting amount of approximately 0.15 mol% or more, heating and degassing can suppress foaming due to unreacted monomers during molding immediately after heating, but unsaturated carboxylic acids are highly hygroscopic. Therefore, if left for a long period of time, it will absorb moisture from the air, causing foaming due to the moisture during molding. Therefore, there has been a desire for a modified polypropylene that does not cause foaming during molding due to moisture absorption, has a low grafting amount of unsaturated carboxylic acid, and has good adhesion to polar substances. In view of the above, the present inventors have conducted various studies on a method for producing modified polypropylene that has a low grafting amount of unsaturated carboxylic acid and has good adhesion to polar substances using a melt-kneading method that is easy to operate and inexpensive. Surprisingly, it was found that 90 to 50 parts by weight of modified polypropylene obtained by the melt-kneading method was mixed with 10 to 50 parts by weight of an atactic propylene-ethylene block copolymer, and the mixture was heat-treated at a temperature of 60°C or higher. We have discovered that by doing so, it is possible to produce a modified polypropylene composition with a low amount of unsaturated carboxylic acid grafted and also with good adhesive properties,
We have arrived at the present invention. The present invention is a modified polypropylene 90 obtained by melt-kneading a mixture of polypropylene, an unsaturated carboxylic acid or its derivative, and an organic peroxide.
After mixing 10 to 50 parts by weight of atactic propylene-ethylene block copolymer with ~50 parts by weight, 60 parts by weight
This is a method for producing a modified polypropylene composition, which is characterized by heat treatment at a temperature of .degree. C. or higher. The modified polypropylene composition obtained by the production method of the present invention can be prepared by simply adding 60% of the modified polypropylene.
Adhesive properties are significantly improved compared to compositions that have been heat treated at temperatures above .degree. C. or compositions that have been melt-kneaded by simply adding an atactic propylene-ethylene block copolymer to modified polypropylene. The mechanism of action of the adhesion-improving effect of the present invention is not clear, but it is believed that the modified polypropylene composition in particular undergoes some structural changes as well as a decrease in unreacted monomers by heat treatment at 60°C or higher. Guessed. Therefore, it is also effective to perform heat treatment at 60° C. or higher for more than just reducing unreacted monomers. The polypropylene used in the present invention is not particularly limited, and includes homopolypropylene, propylene-ethylene random copolymer, propylene-ethylene block copolymer, copolymer of propylene and α-olefin, and mixtures thereof. used. In addition, examples of the unsaturated carboxylic acids used in the present invention include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid, and examples of unsaturated carboxylic acid derivatives include acid anhydrides, There are esters, amides, imides, metal salts, etc., such as maleic anhydride, citraconic anhydride, itaconic anhydride, methyl acrylate,
Methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, glycidyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, Itacon 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-N/N-dibutylamide, maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate, etc. can be mentioned. Of these,
Most preferably maleic anhydride is used. The amount of unsaturated carboxylic acid or its derivative added is not particularly limited, but may be determined depending on the amount of graft reaction of unsaturated carboxylic acid to polypropylene and the amount of unsaturated carboxylic acid in the modified polypropylene composition. It is usually added in an amount of 0.01 to 20 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight of polypropylene. Further, in the present invention, an organic peroxide is used to promote the reaction between polypropylene and an unsaturated carboxylic acid or a derivative thereof. Examples of organic peroxides include benzoyl peroxide, lauroyl peroxide, azobisisobutyronitrile, dicumyl peroxide, α・α′-bis(t-butylperoxydiisopropyl)benzene, 2・5-dimethyl-2・5-di(t-butylperoxy)hexane, 2,5-dimethyl-
2,5-di(t-butylperoxy)hexyne-
3, di-t-butyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, and the like. The amount of organic peroxide added is not particularly limited, but is usually 0.005 to 5 parts by weight,
Preferably it is 0.01 to 1 part by weight. Furthermore, in the present invention, fillers such as talc, calcium carbonate, gypsum, and magnesium oxide; butylated hydroxytoluene, butylated hydroxyanisole, tetrakis[methylene-3(3.5
-di-t-butyl-4-hydroxy-fumanyl)
[propionate] heat stabilizers such as methane; weather stabilizers; lubricants; antistatic agents; nucleating agents; pigments; dyes;
It may also contain an anti-fogging agent. In the present invention, the above-mentioned polypropylene, unsaturated carboxylic acid or its derivative, and organic peroxide are sufficiently mixed in a tumbler, Henschel mixer, etc. The grafting reaction is carried out by melt-kneading at a certain temperature. The method for melt-kneading is not particularly limited, but it can be carried out using, for example, a screw extruder, a Banbury mixer, a mixing roll, or the like. The melt-kneading temperature and time vary depending on the decomposition temperature of the organic peroxide used, but in general, it is appropriate to do it at 160 to 280°C for 0.3 to 30 minutes, preferably at 170 to 250°C for 1 to 10 minutes. Note that the melt-kneading may be performed in an inert gas stream. Next, in the present invention, it is necessary to mix an atactic propylene-ethylene block copolymer with the modified polypropylene produced as described above. Atactic propylene-ethylene block copolymers are generally propylene-ethylene block copolymers.
It is separated as a by-product by solvent extraction as an atactic part in the manufacturing process of ethylene block copolymer.
The weight average molecular weight is in the range of 10,000 to 500,000, mainly consisting of the part soluble in heptane at 60 to 100℃,
And those having an ethylene content in the range of 5 to 50% by weight are preferably used. Generally propylene
The method for producing ethylene block copolymers is a two-step process in which propylene is polymerized in the presence of a catalyst containing titanium trichloride and an organoaluminum compound, and then ethylene and propylene are copolymerized in the presence of the resulting polymer containing the catalyst. There are polymerization methods, etc. The atactic propylene-ethylene block copolymer is a soluble polymer portion obtained by extracting the polymer obtained by these methods with an aliphatic hydrocarbon solvent in the next step. In the present invention, it is important to use an atactic propylene-ethylene block copolymer as the atactic polypropylene; even if atactic homopolypropylene or atactic propylene-ethylene random copolymer is used, the adhesion will not be improved. The amount of the atactic propylene-ethylene block copolymer added is 90% to 50% of the modified polypropylene.
The amount is 10 to 50 parts by weight, preferably 15 to 40 parts by weight to 85 to 60 parts by weight. If the amount added is less than 10 parts by weight, the effect of improving adhesion is small, and if it exceeds 50 parts by weight, not only the adhesion but also the mechanical strength will decrease, which is not preferable. In addition to modified polypropylene and atactic propylene-ethylene block copolymer, unmodified polypropylene can also be mixed. Addition ratio of unmodified polypropylene to modified polypropylene
0 to 80 parts by weight per 100 to 20 parts by weight, preferably 10 to 80 parts by weight per 90 to 30 parts by weight of modified polypropylene
It is 70 parts by weight. Mixing of modified polypropylene, atactic propylene-ethylene block copolymer, or unmodified polypropylene as required can be carried out using a tumbler, a Henschel mixer, or the like. Next, these mixtures are melt-kneaded using, for example, a screw extruder, a Banbury mixer, or a mixing roll. Such melt-kneading corresponds to the heat treatment at 60° C. or higher in the present invention, and unreacted monomers may be removed simultaneously with the kneading. Furthermore, in the present invention, it is extremely important to heat and degas the modified polypropylene composition produced as described above at a temperature of 60°C or higher, preferably 100°C or higher. That is, by such heat treatment, the adhesiveness of the modified polypropylene composition of the present invention is significantly improved compared to conventional modified polypropylene compositions. In particular, the modified polypropylene composition of the present invention exhibits good adhesion even when the amount of unsaturated carboxylic acid grafted is, for example, about 0.15 mol % or less, particularly 0.12 mol % or less, which does not cause foaming during molding. Therefore, according to the present invention, there is provided a modified polyolefin composition that does not cause foaming during molding and has good adhesive properties. When the heating temperature is 60°C or lower, it takes a long time to degas the monomer, which is not practical. Although the upper limit of the heating temperature is not particularly limited, it is preferably below the melting point of the modified polypropylene in order to prevent fusion of the modified polypropylene. The heat treatment can be carried out by conventionally known methods, such as a ventilation band type dryer, material agitation type dryer, fluidized bed dryer, flash dryer, spray dryer, rotary dryer, drum type dryer, and reduced pressure dryer. , an infrared drying device, a far-infrared drying device, a microwave drying device, etc., but a hot air drying device is preferably used. Note that the degassing effect is further improved if heat drying is performed under reduced pressure. The heat treatment time is not particularly limited, but if the heating temperature is low and the modified polypropylene contains a large amount of unreacted monomers, it will take a long time, and if the heating temperature is high and there are few unreacted monomers, it will take a long time. That's fine. Generally, the time is 10 minutes to 10 hours, and it is preferable to heat and degas so that the amount of unreacted monomer is 0.05 mol% or less. The modified polypropylene composition obtained in the present invention not only has good adhesion to unmodified polypropylene, but also has good adhesion to polar substances such as metals, glass, nylon, polyester, and saponified ethylene-vinyl acetate copolymers. Shows adhesion. Therefore, for example, (1) polar resin/modified polypropylene composition/polypropylene, (2) modified polypropylene composition/polar resin/modified polypropylene composition/polypropylene, (3) polypropylene/modified polypropylene composition/polar resin/modified. It is possible to provide a laminate of polypropylene composition/polypropylene or the like with good adhesiveness. Further, when these laminates are stretched, a composite stretched polypropylene film having excellent gas barrier properties, oil resistance, water impermeability and heat sheet properties is obtained. EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples. Note that the various physical properties in this specification were measured by the following methods. ΓMFI 2160 at 230℃ by ASTM D1238−52T
It was measured by a load of g. Amount of Γ Maleic Anhydride A film with a thickness of about 0.1 mm was formed by hot pressing, the infrared absorption spectrum was measured, and the amount of maleic anhydride was determined from the absorption peak intensity of maleic anhydride at 1780 cm ^-1 . The amount of maleic anhydride in the graft reaction was defined as the amount of maleic anhydride in a sample obtained by extracting a film with a thickness of about 0.1 mm for 6 hours with acetone and then drying it under vacuum at a temperature of 50° C. for 24 hours. The amount of residual unreacted maleic anhydride was determined by subtracting the amount of graft-reacted maleic anhydride from the total amount of maleic anhydride. Γ Adhesive strength (T-peel strength) Adhesion between saponified ethylene-vinyl acetate copolymer, nylon and polyethylene terephthalate is achieved by co-extruding both, and after cooling and solidifying, the width is 2 mm in the longitudinal direction.
It was cut into cm pieces and the T-peel strength was measured. Adhesion to glass and aluminum was determined by wiping the glass plate and aluminum plate with xylene, sandwiching modified polypropylene between the two plates, melting at 250℃, pressing, cooling and solidifying, and peeling off by hand. The adhesive strength was measured by looking at the sample. A T-die is attached to a 40 mmφ extruder with Γ tensile modulus L/D = 20, and a sheet with a thickness of 0.5 cm is extruded at 200°C. The obtained sheet is cut into strips with a width of 1 cm in the MD direction, and then stretched A tensile test was conducted using a testing machine at a chuck distance of 5 cm and a tensile speed of 20 mm/min, and the tensile modulus was calculated from the initial slope. Examples 1 to 4, Comparative Examples 1 to 2 MFI = 1.3 g/10 min homopolypropylene 100 parts by weight, maleic anhydride 0.5 parts by weight, 2,5-dimethyl-2,5-di(t-butylperoxy) Hexane (trade name; Kayahexa AD-400) 0.1 part by weight, butylated hydroxytoluene (trade name;
BHT) 0.1 part by weight and calcium stearate 0.1 part by weight were mixed in a Henschel mixer for 5 minutes, and L/
Melt-kneading pelletization was carried out at 220° C. using a D=24 40 mmφ extruder. The MFI of the obtained modified polypropylene was 33.1 g/10 min, and the total amount of maleic anhydride was
0.205 mol%, the amount of maleic anhydride in the graft reaction is
The amount of unreacted maleic anhydride was 0.120 mol%. Next, this modified polypropylene was mixed with a weight average molecular weight of 95,000 and an ethylene content of 22.3 in the proportions shown in Table 1.
% by weight of an atactic propylene-ethylene block copolymer was mixed and melt-kneaded and pelletized at 220°C using a 40 mmφ extruder with L/D=24.
Thereafter, these modified polypropylene compositions were heat-treated at 150° C. for 3 hours using a constant temperature air dryer. MFI of the obtained modified polypropylene composition,
Table 1 shows the maleic anhydride content, the adhesive strength with saponified ethylene-vinyl acetate copolymer (hereinafter also abbreviated as saponified EVA), and the tensile modulus.
The adhesive strength with the saponified ethylene-vinyl acetate copolymer was determined as follows. That is, the modified polypropylene composition is L/D=20
A saponified ethylene-vinyl acetate copolymer (MFI=19.5g/10
minutes, ethylene content 45 mol%, saponification degree 99% or more,
(hereinafter simply abbreviated as saponified EVA) is L/D
= 24 30 mmφ extruders at 200°C through coextrusion T-dies to form coextruded sheets with a thickness of 0.5 mm of the modified polypropylene composition and a thickness of 0.2 mm of the saponified ethylene-vinyl acetate copolymer. , T-peel strength was measured. Note that these modified polypropylene compositions did not foam during molding even when left for a long time.

[Table] Comparative Example 3 The same procedure as in Example 2 was conducted except that attic homopolypropylene having a weight average molecular weight of 31,000 was used in place of the attic propylene-ethylene block copolymer. The MFI of the obtained modified polypropylene composition was 21.8g/10
minutes, the total maleic anhydride amount was 0.079 mol%, the graft reaction maleic anhydride amount was 0.066 mol%, the unreacted maleic anhydride amount was 0.013 mol%, and the saponification
The adhesive strength with EVA was 100 g/2 cm. Comparative Example 4 Same as Example 2 except that an atactic propylene-ethylene random copolymer having a weight average molecular weight of 45,000 and an ethylene content of 4.5% by weight was used in place of the atactic propylene-ethylene block copolymer in Example 2. I did the same thing. The MFI of the obtained modified polypropylene composition was 22.7 g/10 min.
The total amount of maleic anhydride was 0.082 mol%, the amount of graft-reacted maleic anhydride was 0.062 mol%, the amount of unreacted maleic anhydride was 0.020 mol%, and the adhesive strength with saponified EVA was 100 g/2 cm. Comparative Example 5 The same procedure as in Example 2 was carried out except that heating deaeration was not performed in Example 2. The MFI of the obtained modified polypropylene composition was 27.1 g/10 min, the total amount of maleic anhydride was 0.165 mol%, the amount of graft-reacted maleic anhydride was 0.073 mol%, and the amount of unreacted maleic anhydride was 0.092 mol%, The adhesive strength with saponified EVA was 0. It also foamed during molding. Comparative Example 6 MFI=1.3g/10min homopolypropylene 80 parts by weight, weight average molecular weight 95000, ethylene content
20 parts by weight of 22.3% by weight atactic propylene-ethylene block copolymer, 0.3 parts by weight of maleic anhydride
Part by weight, Kayahexa AD-40c0.1 Part by weight, BHT0.1
Part by weight and 0.1 part by weight of calcium stearate were mixed in a Henschel mixer for 5 minutes, and L/D = 24.
Melt kneading pelletization was performed at 220℃ using a 40mmφ extruder, MFI = 17.5g/10min, total maleic anhydride amount 0.179 mol%, graft reaction maleic anhydride amount
A modified polypropylene composition containing 0.127 mol% and an amount of unreacted maleic anhydride of 0.052 mol% was obtained. Then,
This modified polypropylene composition was heat-treated at 150°C for 3 hours using a constant temperature hot air dryer, and MFI=
A modified polypropylene composition was obtained at a rate of 13.1 g/10 minutes, with a total amount of maleic anhydride of 0.148 mol%, an amount of graft-reacted maleic anhydride of 0.125 mol%, and an amount of unreacted maleic anhydride of 0.023 mol%. The adhesive strength between this modified polypropylene composition and saponified EVA was 0. When this modified polypropylene was left for 5 months, small bubbles were generated during molding. Example 6 MF1=0.5 g/10 min, 100 parts by weight of propylene-ethylene random copolymer with ethylene content of 1.0% by weight, 0.5 parts by weight of maleic anhydride, 0.1 parts by weight of digyl peroxide, 0.1 parts by weight of BHT, and Stair. 0.1 part by weight of calcium phosphate was mixed in a Henschel mixer for 5 minutes, and the mixture was melt-kneaded and pelletized at 220°C using a 40 mmφ extruder with L/D=24. MFI of the obtained modified polypropylene = 3.2g/10
The total amount of maleic anhydride was 0.203 mol%, the amount of graft-reacted maleic anhydride was 0.086 mol%, and the amount of unreacted maleic anhydride was 0.117 mol%. 80 parts by weight of this modified polypropylene is combined with 20 parts by weight of propylene-ethylene block copolymer having a total average molecular weight of 53,000 and an ethylene content of 15.2% by weight.
Parts by weight were mixed and melt-kneaded and pelletized at 220°C using a 40 mmφ extruder with L/D=24. next,
This modified polypropylene composition was heat-treated at 145° C. for 3 hours using a constant temperature hot air dryer. MFI of the obtained modified polypropylene composition =
The total amount of maleic anhydride was 0.086 mol%, the amount of graft-reacted maleic anhydride was 0.068 mol%, and the amount of unreacted maleic anhydride was 0.018 mol%. This modified polypropylene composition is L/D=
At 200℃ from 20 40mmφ extruder, also nylon 6
were coextruded from a 30 mmφ extruder with L/D=24 at 250°C through a T=die to form a coextruded sheet with a modified polypropylene composition layer of 0.5 mm thickness and a nylon 6 layer of 0.2 mm thickness. did. The adhesive strength was 2900 g/2 cm. Comparative Example 7 The same procedure as in Example 6 was conducted except that the heat treatment was not performed. The MFI of the obtained modified polypropylene composition was 5.4 g/10 min, the total amount of maleic anhydride was 0.157 mol%, the amount of graft-reacted maleic anhydride was 0.064 mol%, and the amount of unreacted maleic anhydride was 0.093 mol%, The adhesive strength with nylon 6 was 0. Comparative Example 8 MFI=0.5g/10min, 80 parts by weight of propylene-ethylene random copolymer with ethylene content of 1.0% by weight, weight average molecular weight 53000, ethylene content 15.2
Atactic propylene-ethylene block copolymer 20 parts by weight, maleic anhydride 0.3 parts by weight, dicumyl peroxide 0.1 parts by weight, BHT 0.1
Part by weight and 0.1 part by weight of calcium stearate were mixed in a Henschel mixer for 5 minutes, and L/D=
Melt-knead and pelletize with 24 40mmφ extruders,
A modified polypropylene composition was obtained with an MFI of 4.2 g/10 minutes, a total amount of maleic anhydride of 0.205 mol%, an amount of graft-reacted maleic anhydride of 0.136 mol%, and an amount of unreacted maleic anhydride of 0.069 mol%. Next, this modified polypropylene composition was heat-treated at 145°C for 3 hours using a constant temperature hot air dryer to reduce the total amount of maleic anhydride at MFI = 3.7 g/10 minutes.
0.148 mol%, graft reaction maleic anhydride amount
A modified polypropylene composition containing 0.127 mol% and an amount of unreacted maleic anhydride of 0.021 mol% was obtained. The adhesive strength between this modified polypropylene composition and nylon 6 was 100 g/2 cm. Example 7 MFI = 1.2 g/10 min, 100 parts by weight of propylene-ethylene block copolymer with ethylene content of 2.6% by weight, 0.5 parts by weight of maleic anhydride, 0.2 parts by weight of benzoyl peroxide, 0.1 parts by weight of BHT, calcium stearate. 0.1 part by weight was mixed for 5 minutes using a Henschel mixer, and then mixed using a 40 mm extruder with L/D = 24.
Melt-kneading pelletization was performed at 190°C. The MFI of the obtained modified polypropylene was 30.5 g/10 minutes, the total amount of maleic anhydride was 0.233 mol%, the amount of graft-reacted maleic anhydride was 0.092 mol%, and the amount of unreacted maleic anhydride was 0.111 mol%. 80 parts by weight of this modified polypropylene is mixed with 20 parts by weight of an atactic propylene-ethylene block copolymer having a weight average molecular weight of 235,000 and an ethylene content of 30.5% by weight.
Parts by weight were mixed and melt-kneaded and pelletized at 220°C using a 40 mmφ extruder with L/D=24. next,
This modified polypropylene composition was heat-treated at 150°C for 3 hours using a constant temperature hot air dryer, and MFI = 13.1
g/10 minutes, a modified polypropylene composition having a total amount of maleic anhydride of 0.082 mol%, an amount of graft-reacted maleic anhydride of 0.068 mol%, and an amount of unreacted maleic anhydride of 0.014 mol% was obtained. This modified polypropylene composition was
At 200℃ from a 40mmφ extruder, and polyethylene terephthalate from a 30mmφ extruder with L/D=24.
Extruded through coextrusion T-die at 270℃, modified polypropylene composition layer thickness 0.5mm,
A coextruded sheet with a polyethylene terephthalate layer of 0.2 mm thickness was made and the adhesive strength was measured.
It was 500g/2cm. Comparative Example 9 The same procedure as in Example 7 was conducted except that the heat treatment was not performed. MFI of the obtained modified polypropylene composition was 22.5 g/10 min, the total amount of maleic anhydride was 0.179 mol%, the amount of graft-reacted maleic anhydride was 0.070 mol%, and the amount of unreacted maleic anhydride was 0.109 mol%, The adhesive strength with polyethylene terephthalate was zero. Comparative Example 10 MFI=1.2g/10min, 80 parts by weight of propylene-ethylene block copolymer with ethylene content of 2.6%, weight average molecular weight 235000, ethylene content 30.5% by weight
20 parts by weight of atactic propylene-ethylene block copolymer, 0.3 parts by weight of maleic anhydride, 0.2 parts by weight of benzoyl peroxide, 0.1 parts by weight of BHT, and 0.1 parts by weight of calcium stearate were mixed in a Henschel mixer for 5 minutes, and L /D=24 40mm
Melt kneading pelletization was performed at 190℃ using a φ extruder, MFI = 14.3g/10min, total amount of maleic anhydride.
0.203 mol%, graft reaction maleic anhydride amount
A modified polypropylene composition containing 0.148 mol% and an amount of unreacted maleic anhydride of 0.055 mol% was obtained. Next, this modified polypropylene composition was heat-treated at 150°C for 3 hours using a constant-temperature air dryer to reduce the total amount of maleic anhydride at MFI = 12.5 g/10 minutes.
0.152 mol%, graft reaction maleic anhydride amount
A modified polypropylene composition containing 0.135 mol% and an amount of unreacted maleic anhydride of 0.017 mol% was obtained. The adhesive strength between this modified polypropylene composition and polyethylene terephthalate was 100 g/2 cm. Example 8 The modified polypropylene composition used in Example 2 was sandwiched between two glass plates wiped with xylene, melted and pressed at 250°C, and cooled and solidified. This material could not be peeled off by hand. Comparative Example 11 When the modified polypropylene composition used in Comparative Example 5 was subjected to the same experiment as in Example 8, it was easily peeled off by hand. Example 9 The modified polypropylene composition used in Example 2 was sandwiched between two xylene-wiped aluminum plates, melted and pressed at 250°C, and cooled and solidified.
This material could not be peeled off by hand. Comparative Example 12 When the same experiment as in Example 9 was conducted on the modified polypropylene composition used in Comparative Example 5,
It was easily peeled off by hand. Comparative Example 13 The modified polypropylene composition obtained in Comparative Example 5 was dissolved in xylene by boiling, and after cooling, it was precipitated with a large amount of acetone, and then dried under reduced pressure at 50° C. for 24 hours. MFI of this modified polypropylene composition (A) = 22.1g/
After 10 minutes, the total amount of maleic anhydride was 0.083 mol%, the amount of graft-reacted maleic anhydride was 0.067 mol%, and the amount of unreacted maleic anhydride was 0.016 mol%. Next, 100 parts by weight of modified polypropylene composition (A),
0.1 part by weight of BHT and 0.1 part by weight of calcium stearate were mixed in a Henschel mixer for 5 minutes, and L/D
Pelletization was carried out at 220°C using a 40mmφ extruder of =24, but saponification was determined in the same manner as in Example 2.
The adhesive strength with EVA was 200 g/2 cm. Comparative Example 14 The modified polypropylene composition (A) obtained in Comparative Example 13 was extracted with acetone using a Soxhlet extractor for 8 hours, and dried under reduced pressure at 50°C for 24 hours to obtain an MFI of 21.7 g/10.
A modified polypropylene composition (B) having a total amount of maleic anhydride of 0.068 mol %, a graft reaction amount of maleic anhydride of 0.065 mol %, and an amount of unreacted maleic anhydride of 0.003 mol % was obtained. Next, the modified polypropylene composition
(B) 100 parts by weight, maleic anhydride 0.05 parts by weight,
0.1 parts by weight of BHT and 0.1 parts by weight of calcium stearate
Mix the weight parts in a Henschel mixer for 5 minutes,
Pelletization was performed at 220°C using a 40 mmφ extruder with L/D = 24, MFI = 22.5 g/10 minutes, total maleic anhydride amount 0.081 mol%, graft reaction maleic anhydride amount 0.066 mol%, unreacted maleic anhydride amount 0.015
A modified polypropylene composition of mol % was obtained. This composition and saponification obtained in the same manner as in Example 2
The adhesive strength with EVA was 100 g/2 cm. Comparative Example 15 The same procedure as Comparative Example 12 was conducted except that maleic anhydride was not added in Comparative Example 14. The adhesive strength between the obtained modified polypropylene composition and saponified EVA was 1400 g/2 cm. Table 2 below shows Example 2 and Comparative Examples 13, 14 and
15 results are also shown.

【table】

【table】

Claims (1)

[Scope of Claims] 1. Atactic propylene-ethylene block copolymer 10 to 90 to 50 parts by weight of modified polypropylene obtained by melt-kneading a mixture of polypropylene, an unsaturated carboxylic acid or its derivative, and an organic peroxide. A method for producing a modified polypropylene composition, which comprises mixing ~50 parts by weight and then heat-treating at a temperature of 60°C or higher. 2. The method according to claim 1, wherein the unsaturated carboxylic acid derivative is maleic anhydride. 3. The method according to claim 1, wherein the heating temperature is 100°C or higher and lower than the melting point of the modified polypropylene. 4. The method according to claim 1, wherein the modified polypropylene composition is heated and degassed so that the amount of residual end-reacted monomer in the modified polypropylene composition is 0.05 mol% or less. 5. The method according to claim 1, wherein the atactic propylene-ethylene block copolymer has a weight average molecular weight of 10,000 to 500,000 and an ethylene content of 5 to 50 parts by weight. 6 Modified polypropylene contains 100 parts by weight of polypropylene and 0.05 to 0.05 parts of unsaturated carboxylic acid or its derivative.
The method according to claim 1, wherein the modified polypropylene is obtained by melt-kneading a mixture consisting of 5 parts by weight and 0.01 to 1 part by weight of an organic peroxide.