JPH07188482A - Polypropylene resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition excellent in extrusion moldability in e.g. laminate molding, blow molding, film molding and sheet molding, especially in laminate molding. CONSTITUTION:This composition comprises 30-99wt.% polypropylene, 0.5-69.5wt.% polypropylene modified by grafting of an unsaturated carboxylic acid or its derivative and 0.5-69.5wt.% polypropylene modified by grafting of a compound reactive with the unsaturated carboxylic acid or its derivative.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene resin composition excellent in extrusion molding of polypropylene resin laminates, films, blows, sheets and the like, particularly laminate molding.

[0002]

2. Description of the Related Art Polypropylene is widely used because it has excellent properties such as heat resistance, rigidity, scratch resistance, moisture resistance and water resistance, and is inexpensive. For example, by injection molding, it is often used for various industrial parts such as automobiles and home appliances, and general sundries. Also, by extrusion lamination molding, by laminating on paper, release paper, printing paper,
It is used for thermal transfer paper, process paper for manufacturing artificial leather, and the like. It is also used as a packaging material for food packaging materials by laminating it on a biaxially oriented polypropylene film, polyester film, polyamide film, aluminum foil, or the like. Further, by blow molding, it is often used for industrial parts such as hollow containers and automobile seats. In addition, after being formed into a sheet, it is used for various containers and industrial parts by secondary forming processing such as vacuum forming, pressure forming and vacuum pressure forming.

Polypropylene having such characteristics generally has low viscosity or tension when melted and has excellent suitability for injection molding and the like, but does not have sufficient suitability for extrusion molding such as lamination and blow. There is a drawback that. For example, in the case of laminate molding, it is generally necessary to carry out molding at a high temperature of about 270 ° C. to 300 ° C. in order to have adhesiveness with paper, polypropylene, polyester, polyamide or the like. However, since the melt tension of polypropylene is small, the melt film becomes unstable at such a temperature, and the width and the thickness are likely to change, and thus extrusion-molding with polypropylene alone was very difficult.

Various methods have been proposed to solve this problem. For example, Japanese Examined Patent Publication No. 47-30614 discloses a method of blending low-density polyethylene to improve the moldability of polypropylene. According to this method, the melt film is stable, and extrusion laminate molding can be stably performed in a wide range of molding conditions. However, in this method, since polyethylene, which has lower heat resistance than propylene, is blended, there is a problem that the heat resistance of the laminated film is lowered. Further, since the polyethylene has low scratch resistance, the laminate film also has low scratch resistance. Furthermore, polyethylene and polypropylene are basically not compatible with each other, which causes problems such as deterioration of transparency and adhesiveness. Moreover, the drawbacks that the high-speed moldability is not sufficient and the neck-in is significantly larger than that of low-density polyethylene cannot be solved. Further, JP-A-62-121704 discloses that a propylene homopolymer having a long chain branch has good suitability for extrusion lamination. But,
Although such a method can improve moldability such as neck-in, it has a drawback that defects such as gel and fish eyes are likely to occur, which is not sufficient.

On the other hand, even in blow molding, since the melt tension is small, the parison is unstable and it is difficult to obtain a large molded product. Polypropylene, which has low fluidity, is used to improve this, but the fact is that it is not a fundamental improvement in moldability due to the drawbacks such as uneven thickness of the molded product.

[0006]

As described above, polypropylene resin has excellent properties such as heat resistance, scratch resistance, hardness and rigidity, but on the other hand, it has a low melt viscosity or melt tension. There is a drawback that extrusion moldability in molding, blow molding and the like is not sufficient. The present invention is
In view of such a situation, it is an object to provide a polypropylene resin composition that does not impair the excellent properties of polypropylene and has excellent extrusion moldability.

When random copolymerized polypropylene among polypropylenes is to be used for extrusion lamination, the transparency, high-speed moldability, low temperature heat sealability, etc. which the random copolymerized polypropylene originally has are sufficiently utilized by conventional techniques. It wasn't clean. Another object of the present invention is to provide a polypropylene composition for extrusion lamination, which has a moldability suitable for extrusion lamination and maintains the excellent properties of random copolymerized polypropylene.

[0008]

Means for Solving the Problems As a result of investigations by the present inventors in order to solve the above-mentioned problems, as a result of using the modified polypropylene obtained by grafting polypropylene with a compound having a specific functional group, The inventors have found that the above can be achieved, and have completed the present invention based on this finding. That is, the present invention relates to (A) polypropylene 30 to 9
9% by weight, (B) modified polypropylene graft-modified with unsaturated carboxylic acid or its derivative 0.5 to
A polypropylene resin composition comprising 69.5% by weight and (C) 0.5 to 69.5% by weight of modified polypropylene graft-modified with a compound capable of chemically reacting with an unsaturated carboxylic acid or a derivative thereof. Is.
Hereinafter, the present invention will be specifically described.

The polypropylene which is the component (A) used in the present invention is a propylene homopolymer or a propylene copolymer. The propylene copolymer is a copolymer of propylene and α-olefin, and a block or random copolymer is used. The α-olefin is an unsaturated hydrocarbon having a double bond at the molecular end and having a carbon number of 2 to 20, and ethylene, 1-butene, 1-pentene, 1-hexene and the like are exemplified, but in this case Absent. These α-olefins can be copolymerized alone or in combination of two or more with propylene. Examples of the propylene copolymer include a propylene-ethylene copolymer, a propylene-1-butene copolymer, a terpolymer of propylene, ethylene and 1-butene. The copolymerization ratio of these copolymerization components is usually 1 to 20.
%, Preferably 2 to 10% by weight. In addition, these copolymers contain a small amount of polyfunctional olefins during polymerization,
For example, a copolymer obtained by adding 1,9-decadiene, 1,4-hexadiene, isoprene, 1,3-butadiene and the like can also be used. The melt flow rate of polypropylene (according to JIS K6758, hereinafter referred to as MFR) is generally 0.01 to 200 g / 10 minutes, and 0.
05-100 g / 10 minutes is preferable, and 0.5-50 g /
10 minutes is particularly preferred. These polypropylenes may be used alone or in combination of two or more.

The modified polypropylene used as the component (B) in the present invention is a polypropylene grafted with a carboxylic acid or a derivative thereof. As polypropylene, a propylene homopolymer or a propylene copolymer is used. Like the component (A), the propylene copolymer is a block or random copolymer of propylene and α-olefin. Further, these copolymers contain a small amount of polyfunctional olefins such as 1,9-decadiene, 1,4-hexadiene, isoprene and 1,3 at the time of polymerization.
-A copolymer obtained by adding butadiene or the like can also be used. These modified polypropylenes may be used alone or in combination of two or more.

Specific examples of the unsaturated carboxylic acid or its derivative include acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid and the like, or their acid anhydrides and ester metal salts. To be The graft amount of the unsaturated carboxylic acid or its derivative is usually 0.01 to 10% by weight, and 0.0
3 to 5% by weight is preferable, and 0.05 to 1.0% by weight is particularly preferable. If the graft amount of the unsaturated carboxylic acid or its derivative is less than 0.01% by weight, the extrusion moldability, which is the object of the present invention, cannot be improved. On the other hand, if it exceeds 10% by weight, a large amount of gel component is generated to cause a problem in appearance, and in the case of laminate molding, for example, high-speed moldability is deteriorated, which is not preferable.

Various known methods can be adopted as the grafting method. For example, a method of adding an unsaturated carboxylic acid or its derivative and an organic peroxide to polypropylene, dry-blending in advance and then melt-kneading, or dissolving polypropylene in a solvent to form an unsaturated carboxylic acid or its derivative and an organic peroxide. There is a method of adding and reacting.

M of the modified polypropylene which is the component (B)
FR is usually 0.01 to 2 although it varies depending on the grafting ratio.
00 g / 10 minutes, preferably 0.1 to 150 g / 10 minutes, particularly preferably 0.5 to 50 g / 10 minutes.

Modified polypropylene (C) used in the present invention
Is a compound modified with a compound capable of chemically reacting with an unsaturated carboxylic acid or a derivative thereof, and in particular, is a product obtained by grafting an unsaturated hydroxy compound, an unsaturated epoxy compound or an unsaturated isocyanate compound on the polypropylene.

Examples of unsaturated hydroxy compounds include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, glycerol mono- or di (meth) acrylate, trimethylolpropane or di- or tri ( (Meth) acrylate, ethylene glycol monoallyl ether, propylene glycol monoallyl ether, polyethylene glycol monoallyl ether, o-, m- or p-hydroxymethylstyrene and mixtures thereof.

Examples of unsaturated epoxy compounds include glycidyl (meth) acrylate, allyl glycidyl ether, allyl glycidyl phthalate, vinyl cyclohexene oxide, allyl glycidyl succinate, allyl glycidyl maleate and the like.

Examples of unsaturated isocyanate compounds include (meth) acryloxyethyl isocyanate, (meth) acryloxypropyl isocyanate, and (meth) acryloxyhexyl isocyanate.

A graft reaction is generally used for modifying a compound capable of chemically reacting with an unsaturated carboxylic acid or its derivative. The graft amount is usually 0.01 to 10% by weight,
0.03 to 5% by weight is preferable, and 0.05 to 1.0% by weight is particularly preferable. If the graft amount is less than 0.01% by weight, the extrusion moldability, which is the object of the present invention, cannot be improved. On the other hand, if it exceeds 10% by weight, a large amount of gel component is generated, causing not only a problem in appearance but also, for example, in the case of laminate molding, high-speed moldability is deteriorated, which is not preferable.

The grafting method is not particularly limited, and the same method as the grafting method of the unsaturated carboxylic acid and its derivative can be used. Unsaturated hydroxy compounds,
The unsaturated epoxy compound, the unsaturated isocyanate compound and the like can be used alone or in combination of two or more kinds.

M of the modified polypropylene which is the component (C)
FR is usually 0.01 to 2 although it depends on the grafting ratio and the like.
00 g / 10 minutes, preferably 0.1 to 150 g / 10 minutes, particularly preferably 0.5 to 50 g / 10 minutes.

The proportion of the component (A) in the polypropylene resin composition of the present invention is 30 to 99% by weight, preferably 40 to 95% by weight. If it is less than 30% by weight, defects such as gel and lumps occur in the molded product, and the hot tack property at a high temperature (130 ° C. or higher) is deteriorated in the laminate molding and it is not economical. If it exceeds 99% by weight, the extrusion moldability is not improved, and the neck-in is not improved in the case of laminate molding.

The proportion of the component (B) in the polypropylene resin composition of the present invention is 0.5 to 69.5% by weight,
It is preferably 1 to 50% by weight. If it is less than 0.5% by weight, the extrusion moldability cannot be improved, and the neck-in cannot be improved in the case of laminate molding. On the other hand, if it exceeds 69.5% by weight, defects such as gel will occur, and in the case of laminate molding, the hot tack property at high temperature will be deteriorated.

The proportion of the component (C) in the polypropylene resin composition of the present invention is 0.5 to 69.5% by weight,
It is preferably 1 to 50% by weight. If it is less than 0.5% by weight, the extrusion moldability cannot be improved, and the neck-in cannot be improved in the case of laminate molding. On the other hand, if it exceeds 69.5% by weight, defects such as gel will occur, and in the case of laminate molding, the hot tack property at high temperature will be deteriorated.

In order to obtain the polypropylene resin composition of the present invention, a conventionally known mixing method, for example, a method of kneading by using an open roll, a Banbury mixer, a kneader, an extruder or the like may be appropriately used. . The kneading temperature is usually 130 ° C to 350 ° C, preferably 1
It is 80 ° C to 300 ° C.

Further, the polypropylene resin composition of the present invention may optionally contain conventional additives such as plasticizers, lubricants,
Various stabilizers, antiblocking agents, antistatic agents, dyes,
Pigments and various fillers may be added.

The base material used for laminate molding using the polypropylene resin composition of the present invention is not particularly limited, but a biaxially stretched polypropylene film is preferable. Corona treatment for these base materials if necessary,
Anchor coat treatment, pretreatment such as preheat treatment, and posttreatment such as aging treatment and heat treatment can be performed.

[0027]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. The types of various polypropylenes used in Examples and Comparative Examples used below are shown below. (A) Component A-1: Propylene homopolymer having MFR of 18 g / 10 minutes A-2: Ethylene-propylene random copolymer having MFR of 5 g / 10 minutes and ethylene content of 4% by weight A-3 : MFR 19 g / 10 minutes, ethylene content 2% by weight, 1-butene content 8% by weight propylene-ethylene-1 butene random copolymer (B) component B-1: MFR 18 g / 10 minutes, Modified propylene homopolymer having a grafted amount of maleic anhydride of 0.5% by weight B-2: Modified propylene homopolymer having an MFR of 100 g / 10 minutes and a grafted amount of maleic anhydride of 2.5% by weight B -3: Propylene homopolymer having an MFR of 18 g / 10 minutes and a grafted amount of maleic anhydride of 0.02% by weight B-4: MFR of 110 g / 10 minutes, of a maleic anhydride Propylene homopolymer having a raft amount of 3.4 wt% B-5: MFR of 110 g / 10 minutes Propylene homopolymer having a graft amount of maleic anhydride of 0.005 wt% B-6: MFR of 18 g / Propylene-ethylene random copolymer (C) component C-1: MFR 15 g / 10 min, 2-hydroxyethyl, 10 minutes, grafted amount of maleic anhydride 0.4% by weight, ethylene content 4% by weight Propylene homopolymer having a graft amount of methacrylate of 1% by weight C-2: MFR of 28 g / 10 minutes, propylene homopolymer having a graft amount of glycidyl methacrylate of 1% by weight C-3: MFR of 40 g / 10 minutes , A propylene homopolymer having a graft amount of methacryloxyethyl isocyanate of 1.1% by weight C-4: MFR of 15 g / 1 Of ethylene-propylene copolymer having a graft amount of 2-hydroxyethyl methacrylate of 0.3% by weight and an ethylene content of 5% by weight, C-5: MFR of 15 g / 10 min, graft of 2-hydroxyethyl methacrylate. Propylene homopolymer having an amount of 0.005% by weight C-6: Propylene homopolymer having an MFR of 105 g / 10 min and a graft amount of glycidyl methacrylate of 3.6% by weight (D) component (A), ( The following high-pressure polyethylene was used as a resin other than the components B) and (C). D-1: Density 0.926 g / cm ³ , JIS K67
High-pressure polyethylene D-2 having a melt flow rate of 20 g / 10 min according to 60 D-2: Density 0.923 g / cm ³ , JIS K67
High-pressure process polyethylene having a melt flow rate of 2 g / 10 min according to 60

(Examples 1 to 14, Comparative Examples 1 to 9) Table 1,
Component (A) whose type and amount are shown in Table 2,
The components (B), (C), and (D) were mixed for 5 minutes using a Henschel mixer, and then melt-kneaded at a temperature of 240 ° C. by an extruder with a vent to form pellets. Using a φ90 mm extruder and a laminate molding machine, the obtained pellets were laminated using a biaxially oriented polypropylene film as a base material at a temperature of 280 ° C. and an air gap of 110 mm. The drawdown property (DD) was evaluated by the speed at which the film was broken by increasing the take-up speed (m / min) at a rotation speed of the extruder of 30 rpm. The neck-in (NI) was formed at a film thickness of 20 μ and a take-up speed of 200 m / min, the coat width on the substrate was measured, and the difference from the die width (mm) was evaluated.

In Examples 1 to 6 and Comparative Examples 1 to 3, the haze and hot tack of the molded films were also measured. The haze was measured according to JIS K6714. The hot tack property is that two samples with a width of 25 mm and a length of 800 mm are sealed, and immediately after that, 46 pieces are applied to each of the two ends.
A load of g was applied to cause peeling, and the peeled distance (mm) was evaluated. The sealing conditions were a seal width of 5 mm, a seal length of 300 mm, a temperature of 110 ° C., a pressure of 2 Kg / cm ² , and a time of 0.5 seconds.

[0030]

[Table 1]

[0031]

[Table 2]

(Example 15) Blow molding was performed using the resin composition of Example 7 shown in Table 1. Blow molding was performed at an extrusion temperature of 230 ° C and a mold temperature of 40 ° C to obtain a hollow molded product.
The resulting hollow molded article had a good appearance.

Comparative Example 10 Blow molding was performed using the resin composition of Comparative Example 9 shown in Table 1. However, the parison was caused to flow and fall, and a hollow molded product could not be obtained.

(Example 16) A film was formed using the resin composition of Example 14 shown in Table 1. Molding is 20
A film forming machine having a 0 mm wide T-die was used to form a film having a thickness of 50 μm at a resin temperature of 255 ° C. and a take-up speed of 3 m / min. The molding could be carried out without any problems. The obtained film had no gel and had a good appearance.

[0035]

EFFECT OF THE INVENTION A polypropylene resin composition having excellent extrusion moldability such as laminate, blow, film and sheet was obtained. Particularly when a random copolymer is used as the component (A), the laminate moldability such as drawdown and neck-in is improved without impairing the advantages of the propylene copolymer such as transparency and high temperature hot tack. . This improves productivity in extrusion lamination and further improves suitability for a packaging machine in a high-speed automatic filling machine.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noritaka Fujiwara 3-2 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Akira Kawasaki Resin Research Laboratory, Waseda Electric Works Co., Ltd. (72) Hiroshi Kasahara Chidori, Kawasaki-ku, Kawasaki-shi, Kanagawa Town No. 3-2 Showa Denko Co., Ltd. Kawasaki Plastics Research Laboratory (72) Inventor Minoru Suzuki Minami No. 2 in Oita City, Oita Prefecture Showa Denko Oita Research Center

Claims (4)

[Claims] 1. A modified polypropylene of (A) 30 to 99% by weight and a modified polypropylene (B) which is graft-modified with an unsaturated carboxylic acid or a derivative thereof.
A polypropylene resin composition comprising 5% by weight and (C) 0.5 to 69.5% by weight of modified polypropylene graft-modified with a compound capable of chemically reacting with an unsaturated carboxylic acid or a derivative thereof. 2. The polypropylene resin composition according to claim 1, wherein the compound (C) capable of chemically reacting with the unsaturated carboxylic acid or its derivative is an unsaturated hydroxy compound. 3. The polypropylene resin composition according to claim 1, wherein the compound (C) capable of chemically reacting with the unsaturated carboxylic acid or its derivative is an unsaturated epoxy compound. 4. The propylene resin composition according to claim 1, wherein the compound (C) capable of chemically reacting with the unsaturated carboxylic acid or its derivative is an unsaturated isocyanate.