JPH07214735A - Translucent polypropylene laminated sheet and method for producing the same - Google Patents

Abstract

(57) [Summary] [Structure] 20% to 80% by weight of crystalline polypropylene having a syndiotactic pentad fraction of 0.6 or more on at least one side of a base layer made of isotactic polypropylene, and propylene and both A translucent polypropylene laminate sheet obtained by laminating a laminate layer made of a syndiotactic polypropylene resin composition containing 80% to 20% by weight of a copolymer with an α-ω diene having a vinyl group at the terminal, and the laminate. A method for producing a translucent polypropylene laminated sheet in which material layers are laminated. [Effect] It becomes possible to provide a translucent sheet that does not have a turbid feeling as compared with conventionally known matte polypropylene sheets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a translucent polypropylene laminated sheet and a method for producing the same, and more particularly to a translucent polypropylene laminated sheet obtained by laminating a syndiotactic polypropylene resin composition on at least one side and a method for producing the same.

[0002]

Polypropylene is used for various purposes because it is inexpensive, has excellent mechanical properties, moisture resistance, heat resistance, and relatively good transparency. Further, it has a good surface gloss and is used in fields where a glossy feeling is required. On the other hand, some products do not have a glossy surface, and in such applications, a method of adding translucent polyethylene or thermoplastic resin, which is poorly compatible with polypropylene, is used to deluster the surface. There is. Isotactic polypropylene is used as the raw material for the translucent polypropylene film and sheet with a matte surface, and although it is translucent, the transparency of the resin itself is low, and it is compatible with polypropylene to make it translucent. Only a whitish and turbid sheet was obtained because it was made semi-transparent by adding polyethylene or a thermoplastic resin, which has a poor quality. In order to improve such a defect, it has been studied to process only the surface of the sheet by a special processing method, but a sheet having sufficient performance has not been obtained. Also known is a method of laminating sheets and using a resin composition in which polyethylene or a thermoplastic resin having poor compatibility with polypropylene is added only to the surface layer, but the performance is not sufficient.

On the other hand, a highly stereoregular syndiotactic polypropylene is synthesized by using a kind of metallocene catalyst called Kaminsky catalyst (Japanese Patent Laid-Open No. 41303/1990).
It is known that the molded product has excellent transparency and is relatively soft polypropylene. The molding and processing characteristics of the syndiotactic polypropylene synthesized by this method are not yet fully understood, and studies have been conducted to produce the desired transparency and glossiness. For example, transparency and softness excellent in surface gloss Its use as a film or sheet is expected. Further, JP-A-4-25514 discloses a propylene / diene copolymer in which a propylene unit has a substantially syndiotactic structure, and a method for producing the same by the present applicant.

[0004]

The method of processing only the surface of the sheet by a special processing method is not only costly, but also does not provide a product having sufficient performance. In addition, a sheet having good properties cannot be obtained even by a method of laminating sheets and using a resin composition in which polyethylene having a poor compatibility with polypropylene or a thermoplastic resin is added only to the surface layer. Syndiotactic polypropylene has a very good transparency of the resin itself, and a sheet having excellent surface gloss can be obtained. On the contrary, it is useful if the translucent sheet can be formed by reducing the gloss. It is desired to produce a translucent film or sheet having a matte surface without impairing the transparency of the resin itself.

[0005]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above problems and obtain a translucent polypropylene laminated sheet. As a result, a specific syndiotactic polypropylene resin composition is added to at least one polypropylene laminated sheet. It was found that a matte sheet having excellent mechanical properties can be obtained by laminating and molding on one surface without impairing the transparency of the resin itself, thus completing the present invention.

That is, according to the present invention, crystalline polypropylene having a syndiotactic pentad fraction of 0.6 or more is 20% by weight to 80% by weight on at least one side of a base material layer made of isotactic polypropylene, and propylene and both ends thereof. A semi-transparent polypropylene laminate characterized by being formed by laminating a stacking layer made of a syndiotactic polypropylene resin composition containing 80% to 20% by weight of a copolymer with an α-ω diene having a vinyl group. It is a sheet. Further, the present invention provides that, on at least one surface of a base material layer made of isotactic polypropylene, 20% by weight of crystalline polypropylene having a syndiotactic pentad fraction of 0.6 or more is used.
Or 80% by weight, and a laminate layer made of a syndiotactic polypropylene resin composition comprising 80% by weight to 20% by weight of a copolymer of propylene and α-ω diene having vinyl groups at both ends. And a method for producing a translucent polypropylene laminated sheet.

As the isotactic polypropylene used as the base layer in the present invention, known propylene homopolymers or other olefins such as ethylene-propylene block copolymers and crystalline ethylene-propylene random copolymers are used. The random copolymer or block copolymer may be used without any problem by the method of industrially producing polyolefin or those widely available in the market. The molecular weight of this isotactic polypropylene is about 0.1 to 20 dl / g as the intrinsic viscosity [η] measured with a tetralin solution at 135 ° C., and the content of other olefins is 0 to 50% by weight.

In the method for producing these isotactic polypropylenes, the catalyst used for polymerization is, for example,
As a catalyst component in which a titanium compound such as titanium trichloride or titanium tetrachloride is supported on a titanium trichloride catalyst or a magnesium compound, a carrier catalyst containing alkylaluminum as a cocatalyst component is used. Further, metal complexes of Group 3, 4 and 5 of the periodic table having a cyclopentadienyl compound represented by a combination of dicyclopentadienyl zirconium dichloride and aluminoxane as a ligand and an aluminoxane compound. Or a homogeneous catalyst using a metal cation complex of Group 3, 4 or 5 of the periodic table having a cyclopentadienyl compound as a ligand can be used.

As the polymerization method, a conventional method such as a solvent polymerization method, a bulk polymerization method in which substantially no solvent is present, or a gas phase polymerization method can be used, and the polymerization conditions are not particularly limited, and the reaction temperature is usually room temperature. ~ 200 ℃, normal pressure ~ 50kg
/ Is carried out in cm ^2.

The crystalline polypropylene used in the present invention having a syndiotactic pentad fraction of 0.6 or more (hereinafter referred to as syndiotactic polypropylene).
As long as it is crystalline, not only a propylene homopolymer but also propylene and ethylene, butene-1, hexene-1
It may be a random copolymer or a block copolymer with other olefins such as. The syndiotactic polypropylene has a molecular weight of about 0.1 to 20 dl / g as an intrinsic viscosity [η] measured with a tetralin solution at 135 ° C.
The content of other olefins is 0 to 50% by weight.

As a method for producing these syndiotactic polypropylenes, there is known a method of polymerizing propylene using a catalyst composed of a transition metal compound having an asymmetric ligand and an aluminoxane (JP-A-2-41303). However, even if the catalysts are different, any method may be used as long as it is a method for producing syndiotactic polypropylene having a syndiotactic pentad fraction of more than 0.6, and those synthesized by any method can be used.

The copolymer of propylene and an α-ω diene having vinyl groups at both terminals (hereinafter referred to as propylene / diene copolymer) used in the present invention is 1,2,4-
In ¹³ C-NMR measured with a trichlorobenzene solution, the peak intensity observed at about 20.2 ppm based on tetramethoxysilane is 0.6 or more of the total peak intensity assigned to the methyl group of propylene, and it has such a structure. The copolymer is produced by a method similar to the method for producing syndiotactic polypropylene as described in JP-A-4-25514, in which propylene and α-ω dienes having vinyl groups at both ends are used. It is obtained by copolymerizing. As this polymerization method, a conventional method such as a solvent polymerization method or a bulk polymerization method in which substantially no solvent is present, a gas phase polymerization method can be used, and the polymerization conditions are not particularly limited, and the reaction temperature is usually from room temperature to 200. ℃, pressure is normal pressure ~ 50kg /
done in cm ² .

The α-ω diene used here may be linear or branched as long as it is a diene compound having a vinyl group at both ends, and may contain a hetero atom or atomic group such as oxygen, sulfur or boron. You can leave. For example, 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, 1,11- dodecadiene,
Examples include 1,13-tetradecadiene and divinylbenzene.

The propylene / diene copolymer thus obtained may be a random copolymer or a block copolymer. The molecular weight of this copolymer is 13
The intrinsic viscosity [η] measured with a tetralin solution at 5 ° C is preferably about 0.1 to 10 dl / g. In addition, the peak intensity observed at about 20.2 ppm on the basis of tetramethoxysilane in ¹³ C-NMR measured with a 1,2,4-trichlorobenzene solution of the propylene chain portion in the copolymer was assigned to the methyl group of propylene. The total peak intensity is 0.6 or more. The copolymer whose peak intensity observed at about 20.2 ppm is less than the total peak intensity of 0.6 attributed to the methyl group of propylene has low stereoregularity in the polypropylene unit, and the rigidity and impact resistance of the polyolefin are low. It is not preferable because the balance becomes poor and the crystallization speed becomes slow, resulting in poor moldability.

The syndiotactic polypropylene resin composition of the present invention is characterized by using a propylene / diene copolymer having a boiling paraxylene insoluble content of 1% by weight or less. If the boiling para-xylene insoluble content exceeds 1% by weight, that is, if the crosslinked gel content is more than 1% by weight, not only the mixing with syndiotactic polypropylene cannot be performed uniformly but the appearance becomes poor, Since the gel is present in the molded product, as a result, a uniform surface matting effect is not exhibited, which is not preferable.

In the syndiotactic polypropylene resin composition, the mixing ratio of syndiotactic polypropylene and propylene / diene copolymer is 20 to 80% by weight of syndiotactic polypropylene and 80% by weight of propylene / diene copolymer. To 20% by weight. If the mixing ratio of syndiotactic polypropylene is less than 20% by weight, the delustering effect on the surface is small, and even if it is used in excess of 80% by weight, further improvement of the effect cannot be expected.

There is no particular limitation on the method of mixing the above-mentioned respective components or the mixing method with known additives such as antioxidants, ultraviolet absorbers, lubricants, antistatic agents, and other nucleating agents which are added as necessary. It is preferable that the respective components are mixed with a Henschel mixer, a V-type blender, etc., and then melt-mixed with an extruder, roll, Banbury mixer, kneader, etc., and once granulated into pellets.

A translucent polypropylene laminated sheet can be produced by laminating the laminate layer made of the syndiotactic polypropylene resin composition obtained as described above on at least one side of the base layer made of isotactic polypropylene. The object of the present invention can be achieved.

Since the laminated sheet thus obtained has a total haze of 50% or more, it can be used as the translucent polypropylene laminated sheet of the present invention. Also,
The center surface average roughness of the laminated material layer surface laminated with the syndiotactic polypropylene resin composition is 0.1 μm to 1.0 μ.
The fact that m is also one of the characteristics of the present invention. If the center surface average roughness of the laminate layer surface is less than 0.1 μm, the haze value is small and there is no translucency, and if it exceeds 1.0 μm, the haze value is large but the laminate layer surface is uneven. It is not preferable.

As a method for producing the laminated sheet of the present invention, known methods are used. For example, the syndiotactic polypropylene resin composition (laminating material layer) and the isotactic polypropylene (base material layer) are combined by die heads by independent extruders and simultaneously extruded and laminated. As the die used here, a die for a multilayer film or a die for a multilayer sheet is used, and it is also possible to extrude with a separate die and laminate it outside the die. Further, a laminate having three or more layers can be manufactured. In the case where the laminated sheet of the present invention is further provided with resistance to permeation of gas such as oxygen and aroma components, vinyl alcohol copolymer, nylon and the like can be further laminated.

[0021]

The present invention will be further described with reference to the following examples.

Example 1 [Synthesis of propylene / diene copolymer] 1 liter of toluene was placed in a stainless steel autoclave having an internal volume of 2 liters, and 0.64 g of methylaluminoxane (manufactured by Tosoh Akzo Co., degree of polymerization 16.2) and 1, 5.3 g of 9-decadiene were charged. Furthermore, propylene gas is introduced at 20 ° C and 3 kg /
cm ² -G, a solution prepared by dissolving 2 mg of isopropyl (cyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride synthesized according to a conventional method in 10 ml of toluene was added, and the temperature was 20 ° C. It was polymerized for 2 hours.

After completion of the polymerization, unreacted propylene was purged and the polymer was taken out by filtration, vacuum dried at 80 ° C. for 8 hours, and weighed. As a result, 145.6 g of propylene / 1,9-decadiene copolymer (hereinafter, It is referred to as a copolymer a).
The composition of the reaction solution before and after the polymerization was analyzed by gas chromatography and the reaction amount of 1,9-decadiene was calculated to be 2.1 g. The content of boiling para-xylene solubles was 99.5%, and no gel was formed.

In ¹ H-NMR, the signal of the terminal vinyl group is 6 pp
It is observed around m and its amount is about 0.2% by weight, and it is considered that most of the double bonds are reacted. Also
In ¹³ C-NMR measured with 1,2,4-trichlorobenzene solution, the peak intensity observed at about 20.2 ppm based on tetramethoxysilane is the ratio of all peak intensities attributed to the methyl group of propylene (hereinafter synd It is 0.92, and the intrinsic viscosity number (hereinafter referred to as [η]) measured with a 135 ° C. tetralin solution is 1.
The ratio of the weight average molecular weight to the number average molecular weight measured with 36,1,2,4-trichlorobenzene (hereinafter referred to as MW / MN) is 8.6.
Met.

[Production of syndiotactic polypropylene] 100 liters of toluene was placed in a stainless steel autoclave having an internal volume of 200 liters, and 64 g of methylaluminoxane (manufactured by Tosoh Akzo, degree of polymerization 16.2) was charged. Furthermore, propylene gas is introduced at 20 ° C and 3 kg / cm
A solution of 0.2 g of isopropyl (cyclopentadienyl) (fluorenyl) zirconium dichloride as ^2- G was dissolved in 1 liter of toluene, and the mixture was polymerized at 20 ° C. for 2 hours. After completion of the polymerization, unreacted propylene was purged and the polymer was taken out by filtration, vacuum dried at 80 ° C. for 8 hours and weighed to obtain 15.6 kg of syndiotactic polypropylene. Syndiotactic pentad fraction is 0.
91, [η] was 1.05, and MW / MN was 2.2.

[Production of Syndiotactic Polypropylene Resin Composition and Laminated Sheet] Copolymer a is added to 100 parts by weight of the syndiotactic polypropylene obtained above.
Add 40 parts by weight, then add 0.1 parts by weight of antioxidant and mix with a Henschel mixer, then at 230 ℃ with an extruder.
The mixture was heated and mixed with to obtain a syndiotactic polypropylene resin composition. This composition and isotactic polypropylene (manufactured by Mitsui Toatsu Chemicals, Inc., JS-G, [η] are
2.1 dl / g) was supplied to each independent 20 mmφ extruder and extruded by a two-layer T die at 210 ° C. and 230 ° C. to obtain a laminated sheet at a roll temperature of 30 ° C. and a take-up speed of 3 m / min. The thickness of this sheet was 10 μm for the syndiotactic polypropylene resin composition layer and 30 μm for the isotactic polypropylene layer. The formability of the sheet was good, and the results are shown in (Table 1). Seat haze is ASTM
D1003, the surface roughness was determined by using a roughness measuring device (Kosaka Laboratory RA-40A) according to JIS B0601 to determine the center surface average roughness.

Example 2 Syndiotactic polypropylene 10 in Example 1
A laminated sheet was formed in the same manner as in Example 1 except that 100 parts by weight of the copolymer a was added to 0 parts by weight. The moldability was good and the results are shown in (Table 1).

Comparative Example 1 Isotactic polypropylene (Mitsui Toatsu Chemicals, Inc., JS-G, [η] is 2.1 dl / g) was used as a single layer at an extrusion temperature of 230 ° C. and a take-up speed of 3 m / min. The sheet was molded to obtain a sheet having a thickness of 40 μm. The results of measuring the physical properties are shown in (Table 1).

Example 3 In the synthesis of a propylene / diene copolymer, isopropyl (cyclopentadienyl) (2,7-di-t-butylfluorenyl) zirconium dichloride was replaced with 2 mg of isopropylidene (cyclopentadienyl fullerene). Copolymerization was carried out in the same manner as in Example 1 except that 5 mg of oleenyl) zirconium dichloride was used, 3.2 g of 1,7-octadiene was used instead of 5.3 g of 1,9-decadiene, and the amount of methylaluminoxane was 1.44 g. As a result, 114.5 g of a propylene / 1,7-octadiene copolymer (hereinafter referred to as a copolymer b) was obtained. The composition of the reaction solution before and after polymerization was analyzed by gas chromatography.
The calculated reaction amount of 1,7-octadiene was 1.85 g. The content of boiling para-xylene solubles was 99.5%, and no gel was formed.

In ¹ H-NMR, the signal of the terminal vinyl group is 6 pp.
It is observed around m and its amount is about 0.3% by weight, and it is considered that most of the double bonds are reacted. The syndiotactic pentad fraction is 0.86, and [η]
Was 1.38 and MW / MN was 8.4. Further, this copolymer b
To the syndiotactic polypropylene 10 obtained in Example 1.
The same procedure as in Example 1 was carried out except that 100 parts by weight was used with respect to 0 parts by weight. The results are shown in (Table 1).

[0031]

[Table 1]

[0032]

INDUSTRIAL APPLICABILITY The present invention is capable of providing a semitransparent sheet having no turbidity, as compared with conventionally known matte polypropylene sheets, and is industrially extremely valuable.

Claims (4)

[Claims] 1. A crystalline polypropylene having a syndiotactic pentad fraction of 0.6 or more is 20% by weight on at least one side of a base material layer made of isotactic polypropylene.
Or 80% by weight, and a laminate layer made of a syndiotactic polypropylene resin composition comprising 80% by weight to 20% by weight of a copolymer of propylene and an α-ω diene having vinyl groups at both ends is laminated. A translucent polypropylene laminated sheet characterized in that. 2. The total haze of the polypropylene laminated sheet is 50.
% Or more and the center surface average roughness of the laminated material layer surface laminated with the syndiotactic polypropylene resin composition is 0.1 μ.
The translucent polypropylene laminated sheet according to claim 1, which has a thickness of m to 1.0 μm. 3. Propylene and α having vinyl groups at both ends
For the copolymer with −ωdiene, the peak intensity observed at about 20.2 ppm on the basis of tetramethoxysilane in ¹³ C-NMR measured with 1,2,4-trichlorobenzene solution was assigned to the propylene methyl group. The total peak intensity is 0.6 or more, and boiling para-xylene insoluble content is 1% by weight or less, 1
The intrinsic viscosity [η] measured with a tetralin solution at 35 ° C is 0.
The translucent polypropylene laminated sheet according to claim 1, which is a propylene / diene copolymer in the range of 1 to 10 dl / g. 4. A crystalline polypropylene having a syndiotactic pentad fraction of 0.6 or more is 20% by weight on at least one side of a base material layer made of isotactic polypropylene.
Or 80% by weight, and a laminate layer made of a syndiotactic polypropylene resin composition comprising 80% by weight to 20% by weight of a copolymer of propylene and α-ω diene having vinyl groups at both ends. A method for producing a translucent polypropylene laminated sheet, comprising: