JPS6239618B2 - - 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 of adding a rubbery substance has been proposed (e.g., Japanese Patent Publication No. 40112/1983, Japanese Patent Application Laid-open No. 80334/1983). . However, since a large amount of unreacted monomer remains in the modified polypropylene produced by the melt-kneading method, simply adding a rubber-like substance to the modified polypropylene will hardly improve the adhesion. On the other hand, the grafting rate of modified polypropylene produced by the melt-kneading method is generally low, and in order to increase the grafting rate and improve adhesion, a method has been proposed in which a rubber-like substance is added in advance and a melt-kneading reaction is carried out. (For example, Special Publication No. 55-5766, Special Publication No. 55-55-
No. 18251). However, the modified polypropylene produced by this method also has the disadvantage that not only does it have insufficient adhesion due to the large amount of unreacted monomer remaining, but it also generates bubbles when molded into films, sheets, blow molding, etc. be. In addition, modified polypropylene obtained by melt-kneading with a rubber-like substance added in advance has poor adhesion to polar substances unless the amount of unsaturated carboxylic acid grafted is about 0.15 mol% or more even after sufficient heat degassing. is not sufficient. If the amount of unsaturated carboxylic acid grafted is approximately 0.15 mol% or more, heating and deaeration can suppress foaming due to unreacted monomers during molding immediately after heating, but unsaturated carboxylic acid has strong hygroscopicity and may last for a long time. If left untreated, it absorbs moisture from the air and foams due to moisture during molding. Therefore, with a low grafting amount of unsaturated carboxylic acid, no foaming occurs during molding due to moisture absorption.
Moreover, a modified polypropylene with good adhesion to polar substances has been desired. The present inventors 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 an easy-to-operate and low-cost melt-kneading method. Surprisingly, after heat-treating the modified polypropylene obtained by the melt-kneading method at a temperature of 60°C or higher, by mixing 10-50 parts by weight of a propylene oxide polymer with 90-50 parts by weight of the modified polypropylene, The inventors have discovered that it is possible to produce a modified polypropylene composition with a low amount of unsaturated carboxylic acid grafted and yet with good adhesive properties, and have arrived at the present invention. The present invention uses modified polypropylene obtained by melt-kneading a mixture of polypropylene, an unsaturated carboxylic acid or its derivative, and an organic peroxide.
This is a method for producing a modified polypropylene composition, which comprises mixing 10 to 50 parts by weight of a propylene oxide polymer to 90 to 50 parts by weight of the modified polypropylene after heat treatment at a temperature of 60° C. or higher. The modified polypropylene composition obtained by the production method of the present invention can be prepared by simply adding 60% of modified polypropylene to the modified polypropylene composition.
Adhesive properties are significantly improved compared to those heat-treated at temperatures above ℃. Although the mechanism of action of the effect of improving adhesion in the present invention is not clear, it is because the modified polypropylene undergoes some structural changes as well as a decrease in unreacted monomers by heat treatment at 60°C or higher. It is assumed that. 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. 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 and 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, and acrylic acid. Glycidyl, glycidyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, monomethyl itaconate, diethyl itaconate,
Acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, maleic acid-
N-monoethylamide, maleic acid-N・N-diethylamide, maleic acid-N-monobutyramide, maleic acid-N・N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-
N-monoethylamide, fumaric acid-N・N-diethylamide, fumaric acid-N-monobutylamide,
Examples include fumaric acid-N.N-dibutylamide, maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate, and the like. Among these, it is most preferable to use maleic anhydride. The amount of the unsaturated carboxylic acid or its derivative added is not particularly limited, but is determined depending on the amount of the unsaturated carboxylic acid grafted onto the polypropylene and, ultimately, the amount of the unsaturated carboxylic acid in the modified polypropylene composition. Usually 0.01 to 20 parts by weight, preferably 0.1 parts by weight per 100 parts by weight of polypropylene
Add 5 parts by weight. 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 added to the organic peroxide is not particularly limited, but it 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, 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 antiblocking 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 of melt-kneading is not particularly limited, but for example, a screw extruder,
This can be done using a Banbury mixer, mixing roll, etc. The temperature and time of melt-kneading vary depending on the decomposition temperature of the organic peroxide used, but generally 160 to 280°C for 0.3 to 30 minutes, preferably 170 to 250°C for 1 to 10 minutes is appropriate. Note that the melt-kneading may be performed in an inert gas stream. In the present invention, the modified polypropylene produced as described above is heated at a temperature of 60°C or higher, preferably 100°C.
It is important to perform the heat treatment at a temperature of ℃ or higher.
If the heating temperature is below 60°C, degassing takes a long time and 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 heating degassing means may be a conventionally known method, such as a ventilation band type dryer, material agitation type dryer, fluidized bed dryer, flash dryer, spray dryer, rotary dryer, drum type dryer, or 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 if heat drying is performed under reduced pressure, the deaeration effect will be further improved. 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; if the heating temperature is high and there is little unreacted monomer, it will take a long time. good. Generally, it is preferable to heat and degas for 10 minutes to 10 hours so that the amount of unreacted monomer is 0.05 mol% or less. However, in order to improve the adhesion of the obtained modified polyolefin composition, it is also preferable to perform a heat treatment beyond removing the unreacted monomers. The modified polypropylene composition of the present invention obtained by such heat treatment has significantly improved adhesive properties. In particular, the modified polypropylene composition of the present invention has an amount of unsaturated carboxylic acid of about 0.15 mol% or less;
In particular, it shows good adhesion even at 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. Next, in the present invention, a propylene oxide polymer is mixed with the modified polypropylene produced as described above. The propylene oxide polymer used in the present invention is not particularly limited, and in addition to those obtained by polymerizing propylene oxide monomer alone, propylene oxide and other epoxy compounds such as ethylene oxide, butene oxide, allyl glycidyl ether, butane A copolymer with diene monoxide or the like can be used. The molecular weight thereof, expressed as the intrinsic viscosity at 35° C. when dissolved in benzene, is preferably in the range of 0.5 to 15. In the present invention, the amount of propylene oxide polymer added is 10 to 50 parts by weight per 90 to 50 parts by weight of modified polypropylene, preferably 15 to 40 parts by weight per 85 to 60 parts by weight. Addition amount is 10
If the amount is less than part by weight, the effect of improving adhesion is small;
Moreover, if it exceeds 50 parts by weight, it is not preferable because not only the adhesive property but also the mechanical strength decreases. In addition to the modified polypropylene and propylene oxide polymer, unmodified polypropylene can also be mixed. The proportion of unmodified polypropylene added is 0 to 100 to 20 parts by weight of modified polypropylene.
80 parts by weight, preferably 90 parts by weight of modified polypropylene
It is 10 to 70 parts by weight relative to 30 parts by weight. Mixing of modified polypropylene, propylene oxide polymer, or if necessary unmodified polypropylene can be carried out using a tumbler, a Henschel mixer, or the like. Further, it is more preferable to melt-knead these mixtures using, for example, a screw extruder, a Banbury mixer, or a mixing roll. The modified polypropylene obtained by the present invention not only has good adhesion to unmodified polypropylene, but also has good adhesion to metals, glass, nylon, polyester, etc.
Shows good adhesion to polar substances such as saponified ethylene-vinyl acetate copolymer. Therefore, for example (1)
Adhesion of polar resin/modified polypropylene composition/polypropylene, (2) modified polypropylene composition/polar resin/modified polypropylene composition/polypropylene, (3) polypropylene/modified polypropylene composition/polar resin/modified polypropylene composition/polypropylene, etc. A laminate with good properties can be provided. Further, when these laminates are stretched, a composite stretched polypropylene film having excellent gas barrier properties, oil resistance, water impermeability and heat sealability 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 For adhesion between saponified ethylene-vinyl acetate copolymer, nylon, and polyethylene terephthalate, both were coextruded, cooled and solidified, and then cut into 2 cm width pieces in the longitudinal direction, 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 mm 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 -40℃) 0.1 part by weight,
Butylated hydroxytoluene (trade name 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 = 24.
Melt-kneading pelletization was performed at 220°C using a 40mmφ extruder. MFI of the obtained modified polypropylene
was 33.1 g/10 minutes, the total amount of maleic anhydride was 0.205 mol%, the amount of graft-reacted maleic anhydride was 0.085 mol%, and the amount of unreacted maleic anhydride was 0.120 mol%. This modified polypropylene was heat-treated at 150° C. for 3 hours using a constant temperature hot air dryer. The MFI of the obtained modified polypropylene was 19.5 g/10 min, the total amount of maleic anhydride was 0.101 mol%, the amount of graft-reacted maleic anhydride was 0.081 mol%, and the amount of unreacted maleic anhydride was 0.020 mol%. Next, this modified polypropylene was homopolymerized with propylene in the proportions shown in Table 1 to obtain a product with an intrinsic viscosity of 5.0.
of polypropylene oxide are mixed, L/D=
Melt-kneading pelletization was performed at 220°C using a 40mmφ extruder. Table 1 shows the MFI, maleic anhydride content, adhesive strength with saponified ethylene-vinyl acetate copolymer, and tensile modulus of the obtained modified polypropylene composition. The adhesive strength with the saponified ethylene-vinyl acetate copolymer was determined as follows. That is, the modified polypropylene composition was
A saponified ethylene-vinyl acetate copolymer (MFI = 19.5 g/10 min, ethylene content 4.5 mol%, saponification degree of 99% or more, or less
(also abbreviated as EVA saponified product) is L/D=24 of 30
The modified polypropylene composition was extruded through a coextrusion T-die at 200°C from a mmφ extruder, and the saponified ethylene-vinyl acetate copolymer was extruded into coextrusion sheets with a thickness of 0.5 mm and a saponified ethylene-vinyl acetate copolymer sheet with a thickness of 0.2 mm. Peel strength was measured. Note that these modified polypropylene compositions did not foam during molding even when left for a long period of time.

[Table] Comparative Example 3 The same procedure as in Example 2 was carried out except that modified polypropylene which was not heat-treated was used in Example 2. MFI of the obtained modified polypropylene composition
= 23.1 g/10 min, total maleic anhydride amount is 0.162 mol%, graft reaction maleic anhydride amount is 0.064 mol%, unreacted maleic anhydride amount is 0.098 mol%, adhesive strength with saponified EVA is 0 It was hot.
It also foamed during molding. Comparative Example 4 80 parts by weight of homopolypropylene with MFI = 1.3 g/10 minutes, 20 parts by weight of polypropylene oxide with specific gravity 0.919 and intrinsic viscosity 5.0, 0.3 parts by weight of maleic anhydride, 0.1 part by weight of Kayahexa AD-40C, 0.1 part by weight of BHT. 1 part and 0.1 part by weight of calcium stearate were mixed in a Henschel mixer for 5 minutes, and L/D = 24 40
Melt kneading pelletization was performed at 220℃ using a mmφ extruder, MFI = 12.5g/10 minutes, total amount of maleic anhydride.
0.171 mol%, graft reaction maleic anhydride amount
A modified polypropylene composition containing 0.118 mol% and an amount of unreacted maleic anhydride of 0.053 mol% was obtained. Next, this modified polypropylene composition was heat-treated at 150°C for 3 hours using a constant temperature air dryer, and MFI=
A modified polypropylene composition was obtained at a rate of 10.3 g/10 minutes, with a total amount of maleic anhydride of 0.135 mol%, an amount of graft-reacted maleic anhydride of 0.110 mol%, and an amount of unreacted maleic anhydride of 0.025 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 MFI = 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 dicumyl 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 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%. This modified polypropylene was heat-treated at 145° C. for 3 hours using a constant temperature hot air dryer. MFI of the obtained heat-treated modified polypropylene = 2.1g/10
The total amount of maleic anhydride was 0.110 mol%, the amount of graft-reacted maleic anhydride was 0.075 mol%, and the amount of unreacted maleic anhydride was 0.035 mol%. Next, this heat-treated modified polypropylene 80
20 parts by weight of polypropylene oxide having an intrinsic viscosity of 2.5 was mixed with the weight part, 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 composition = 3.1
g/10 min, total maleic anhydride amount is 0.079 mol%,
The amount of maleic anhydride in the graft reaction is 0.062 mol%,
The amount of unreacted maleic anhydride was 0.017 mol%. This modified polypropylene composition L/D=20
Nylon 6 was coextruded through a coextrusion T-die from a 40 mmφ extruder with L/D=24 at 200°C and nylon 6 was coextruded from a 30 mmφ extruder with L/D=24 at 250°C, and the modified polypropylene composition layer had a thickness of 0.5 mm and nylon 6 A coextruded sheet with a layer thickness of 0.2 mm was formed. The adhesive strength was 1700 g/2 cm. Comparative Example 5 The same procedure as in Example 6 was conducted except that modified polypropylene that was not heat-treated was used. MFI of the obtained modified polypropylene composition
= 3.9 g/10 min, the total amount of maleic anhydride was 0.159 mol%, the amount of graft-reacted maleic anhydride was 0.065 mol%, the amount of unreacted maleic anhydride was 0.094 mol%, and the adhesive strength with nylon 6 was 0. It was hot. Comparative Example 6 MFI=0.5g/10min, 80 parts by weight of propylene-ethylene random copolymer with ethylene content of 1.0% by weight, polypropylene oxide 20 with intrinsic viscosity of 2.5
Parts by weight, 0.3 parts by weight of maleic anhydride, 0.1 parts by weight of dicumyl 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 melted in a 40 mmφ extruder with L/D = 24. Perform kneading and pelletizing, MFI = 2.5
g/10 minutes, a modified polypropylene composition having a total amount of maleic anhydride of 0.173 mol%, an amount of graft-reacted maleic anhydride of 0.118 mol%, and an amount of unreacted maleic anhydride of 0.055 mol% was obtained. 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 = 2.2 g/10 minutes.
0.125 mol, graft reaction maleic anhydride amount 0.110
A modified polypropylene composition with an amount of unreacted maleic anhydride of 0.015 mol% was obtained. The adhesive strength between this modified polypropylene composition and nylon 6 is 0.
It was hot. 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 melt-kneaded and pelletized using a 40 mmφ extruder with L/D=24 at 190°C. MFI of the obtained modified polypropylene = 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 0.141 mol%. This modified polypropylene was heat-treated at 150℃ for 3 hours using a constant temperature hot air dryer, and MFI = 18.5g/10
A modified polypropylene was obtained in which the total amount of maleic anhydride was 0.110 mol %, the amount of graft-reacted maleic anhydride was 0.080 mol %, and the amount of unreacted maleic anhydride was 0.030 mol %. Next, 20 parts by weight of a propylene oxide copolymer having an allyl glycidyl ether content of 5.2% by weight and an intrinsic viscosity of 8.7 was mixed with 80 parts by weight of this heat-treated modified polypropylene, and the mixture was heated at 220°C using a 40 mmφ extruder with L/D=24. Melt-kneading pelletization was performed.
MFI of the obtained modified polypropylene composition = 9.5
g/10 min, total maleic anhydride amount is 0.082 mol%,
The amount of maleic anhydride in the graft reaction is 0.063 mol%,
The amount of unreacted maleic anhydride was 0.019 mol%. This modified polypropylene composition was
At 200℃ from a 40mmφ extruder, and polyethylene terephthalate from a 30mmφ extruder with L/D=24.
Each was extruded through a coextrusion T-die at 270°C to produce a coextruded sheet with a modified polypropylene composition of 0.5 mm thickness and a polyethylene terephthalate layer of 0.2 mm thickness, and the adhesive strength was measured.
It was 300g/2cm. Comparative Example 7 The same procedure as in Example 7 was conducted except that modified polypropylene that was not heat-treated was used. MFI of the obtained modified polypropylene composition
= 17.2 g/10 minutes, the total amount of maleic anhydride was 0.171 mol%, the amount of graft-reacted maleic anhydride was 0.069 mol%, the amount of unreacted maleic anhydride was 0.102 mol%, and the adhesive strength with polyethylene terephthalate was 0. Ta. Comparative Example 8 MFI = 1.2 g/10 min, 80 parts by weight of propylene-ethylene block copolymer with ethylene content of 2.6%, allyl glycidyl ether content of 5.2% by weight, 20 parts by weight of propylene oxide copolymer with intrinsic viscosity of 8.7, anhydrous. 0.3 parts by weight of maleic acid, 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 for 5 minutes using a Henschel mixer, and then melt-kneaded and pelletized at 190°C using a 40 mmφ extruder with L/D=24. MFI=
9.2 g/10 minutes, total maleic anhydride amount 0.195 mol%,
A modified polypropylene composition containing a graft-reacted maleic anhydride amount of 0.138 mol% and an unreacted maleic anhydride amount of 0.057 mol% was obtained. Next, this modified polypropylene composition was heat-treated at 150°C for 3 hours using a constant temperature hot air dryer, and MFI = 7.1 g/10 minutes, total maleic anhydride amount.
0.147 mol%, graft reaction maleic anhydride amount
A modified polypropylene composition containing 0.130 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 zero. 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 9 When the modified propylene composition used in Comparative Example 3 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 10 When the same experiment as in Example 9 was conducted on the modified polypropylene composition used in Comparative Example 3,
It was easily peeled off by hand. Comparative Example 11 The modified polypropylene obtained in Example 2 was dissolved in xylene by boiling, and after cooling, it was precipitated with a large amount of acetone, filtered, and then dried under reduced pressure at 50° C. for 24 hours. The MFI of this modified polypropylene (A) was 21.5 g/10 min, the total amount of maleic anhydride was 0.108 mol%, the amount of graft-reacted maleic anhydride was 0.081 mol%, and the amount of unreacted maleic anhydride was 0.027 mol%. . Next, 80 parts by weight of modified polypropylene (A), 20 parts by weight of polypropylene oxide with an intrinsic viscosity of 5.0, 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 a 40 mm
Pelletize at 220℃ using a φ extruder and MFI
= 18.5 g/10 minutes, a modified polypropylene composition having a total amount of maleic anhydride of 0.080 mol%, an amount of graft-reacted maleic anhydride of 0.065 mol%, and an amount of unreacted maleic anhydride of 0.015 mol% was obtained. It was determined in the same manner as in Example 2. The adhesive strength between this composition and saponified EVA was 100 g/2 cm. Comparative Example 12 The modified polypropylene (A) obtained in Comparative Example 11 was extracted with acetone for 8 hours using a Soxhlet extractor, and
Modified polypropylene (B) was dried under reduced pressure at ℃ for 24 hours to obtain a modified polypropylene (B) with MFI = 19.0 g/10 min, total maleic anhydride amount of 0.082 mol%, graft reaction maleic anhydride amount of 0.079 mol%, and unreacted maleic anhydride amount of 0.003 mol%. I got it. Next, 80 parts by weight of modified polypropylene (B), 20 parts by weight of polypropylene oxide with an intrinsic viscosity of 50, 0.05 parts by weight of maleic anhydride, 0.1 part by weight of BHT, and 0.1 part by weight of calcium stearate were mixed for 5 minutes in a Henschel mixer. Pelletization was performed at 220℃ using a 40mmφ extruder with /D=24, and MFI=19.1
A modified polypropylene composition was obtained with a total amount of maleic anhydride of 0.080 mol %, an amount of graft-reacted maleic anhydride of 0.064 mol %, and an amount of unreacted maleic anhydride of 0.016 mol %. It was determined in the same manner as in Example 2. The adhesive strength between this composition and saponified EVA is 100
g/2cm. Comparative Example 13 The same procedure as Comparative Example 12 was conducted except that maleic anhydride was not added. MFI of the obtained modified polypropylene composition = 18.0g/10
The total amount of maleic anhydride was 0.065 mol%, the amount of graft-reacted maleic anhydride was 0.063 mol%, and the amount of unreacted maleic anhydride was 0.002 mol%, which were determined in the same manner as in Example 2. This composition and saponification
The adhesive strength with EVA was 1100 g/2 cm. Table 2 below shows Example 2 and Comparative Examples 11, 12 and 13.
The results are also shown.

【table】

【table】

Claims (1)

[Claims] 1. Modified polypropylene obtained by melt-kneading a mixture of polypropylene, an unsaturated carboxylic acid or its derivative, and an organic peroxide is heated at a temperature of 60°C or higher, and then the modified polypropylene 90 ~50 parts by weight of propylene oxide polymer 10
A method for producing a modified polypropylene composition, characterized by mixing ~50 parts by weight. 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 is heated and degassed so that the residual unreacted monomer in the modified polypropylene is 0.05 mol% or less. 5 Propylene oxide polymer has an intrinsic viscosity of 0.5
-15 polypropylene oxide. 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.