JP2002249167A - Film for heat-shrinkable polypropylene base shrink label - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heating shrinkage characteristics, in particular, the low temperature shrink characteristics and accomplish the low specific gravity. To provide a film for heat-shrinkable polypropylene for shrink label is excellent in balancing of shrink packing property and recycling efficiency and the elastic modulus in tension. SOLUTION: In this film for heat shrinkage polypropylene shrink label, a film for shrink label is characterized in consisting of plastic film for polypropylene shrink label, preferably crystalline propylene α-olefin random copolymer having the special properties, the shrinkage percentage of the main shrinkage direction satisfies equations 1 to 3, and the specific gravity is not greater than 0.94 and the shrinkage percentage in the main shrinkage direction for seven days at 40 deg.C is less than 3%. 1.Equation 1: S80 >251d-215 2.Equation 2: S90 >531d-462 3.Equation 3: S100 >627d-541 Where S80 , S90 and S100 indicate the shrinkage percentages (%) in the main shrinkage direction when in water bath for 10 seconds at 80 deg.C, 90 deg.C, and 100 deg.C respectively, and d the film specific gravity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-shrinkable polypropylene shrink label film. More specifically, the present invention relates to a heat-shrinkable polypropylene shrink label film having an improved heat shrinkage, particularly an improved low-temperature shrinkage.

[0002]

2. Description of the Related Art In recent years, the purpose of packaging articles is to improve the appearance, to prevent the contents from being directly impacted, to tightly package them, to protect glass bottles or plastic bottles, and to label products that combine the display of goods. Shrink labels are widely used. As plastic materials used for these purposes, polyvinyl chloride, polystyrene, polyethylene terephthalate, polypropylene and the like are known. However, although the polyvinyl chloride label has excellent shrink properties, it has a problem of environmental pollution such as generation of chlorine gas at the time of incineration. Further, polystyrene and polyethylene terephthalate labels have good heat shrinkage but have a small difference in specific gravity from polyethylene terephthalate bottles, so that they are difficult to float and separate, and hinder the recycling of polyethylene terephthalate bottles. Furthermore, in order to obtain sufficient heat shrinkability, a resin having poor heat resistance is used, and there is a problem that when retort sterilization is performed, a printing ink flow occurs due to a molten resin. As described in JP-A-60-135233, a method of adding polybutene-1 or a low-melting-point polyolefin resin to a propylene / α-olefin random copolymer is also known, but the heat shrinkage is improved. However, the rigidity of the film tends to decrease, secondary processing characteristics such as printing deteriorate, and productivity in the step of attaching a label to a PET bottle tends to decrease.

[0003] Polypropylene has a large difference in specific gravity from polyethylene terephthalate bottles, is easily floated and separated, and has excellent heat resistance, but has insufficient low-temperature shrinkage.
In order to improve the low-temperature shrinkability, a method of adding a propylene-butene-1 copolymer to polypropylene and a method of adding a petroleum resin or a terpene resin (Japanese Patent Laid-Open No. 62-62)
846) is known, but there is a problem that increasing the shrinkage increases the specific gravity. When the specific gravity of the shrink label increases, the efficiency of the floating separation due to the difference in specific gravity between the bottle and the label decreases in the recycling process of the PET bottle. Therefore, further improvement in the shrinkage performance of the polypropylene resin as a base is desired.

[0004]

It is an object of the present invention to improve the heat shrinkage, especially the low temperature shrinkage, and achieve a low specific gravity under such circumstances. Another object of the present invention is to provide a polypropylene-based heat-shrinkable shrink label film having an improved balance between shrink packaging suitability and recycling efficiency. Furthermore, it is also an object of the present invention to secure sufficient film stiffness for secondary processing and a label mounting process.

[0005]

The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, have found that a specific crystalline propylene / α-olefin random copolymer and a specific alicyclic carbon The present inventors have found that a heat-shrinkable polypropylene shrink label film having improved low-temperature shrinkage can be obtained by using a resin composition containing a hydrogen resin in a specific ratio, and have completed the present invention.

That is, the present invention (Claim 1) is a film comprising a polypropylene resin composition, wherein the shrinkage in the main shrinkage direction satisfies the following expression, and the specific gravity is 0.1.
The heat shrinkable polypropylene shrink label film has a shrinkage ratio in the main shrinkage direction at 94 ° C. or less at 40 ° C. for 7 days of less than 3%. S ₈₀ > 251d-215 S ₉₀ > 531d-462 S ₁₀₀ > 627d-541 (however, S ₈₀ , S ₉₀ , and S ₁₀₀ each have a film thickness of 80
The shrinkage (%) in the main shrinkage direction when water bathed in water at 90 ° C., 90 ° C., and 100 ° C. for 10 seconds, and d represents the specific gravity of the film. The present invention (Claim 2) is a film comprising a polypropylene resin composition, wherein the shrinkage in the main shrinkage direction satisfies the formula (1) and the specific gravity is 0.94 or less, and
C, the shrinkage in the main shrinkage direction for 7 days is less than 3%,
Film flow direction (MD) or orthogonal direction (TD)
The heat-shrinkable polypropylene shrink label film, wherein the lower one has a tensile modulus of 1000 MPa or more. S ₈₀ > 251d-215 S ₉₀ > 531d-462 S ₁₀₀ > 627d-541 (however, S ₈₀ , S ₉₀ , and S ₁₀₀ each have a film thickness of 80
The shrinkage (%) in the main shrinkage direction when water bathed in water at 90 ° C., 90 ° C., and 100 ° C. for 10 seconds, and d represents the specific gravity of the film. )

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-shrinkable polypropylene shrink label film of the present invention will be described in detail below.

[I] Film Properties The heat shrinkable polypropylene shrink label film of the present invention needs to satisfy the following formulas with respect to the shrinkage in the main shrinkage direction. S ₈₀ > 251d-215 S ₉₀ > 531d-462 S ₁₀₀ > 627d-541 (however, S ₈₀ , S ₉₀ , and S ₁₀₀ each have a film thickness of 80
The shrinkage (%) in the main shrinkage direction when water bathed in water at 90 ° C., 90 ° C., and 100 ° C. for 10 seconds, and d represents the specific gravity of the film. Those not satisfying the formulas (1) to (4) have a poor balance between the shrinkage ratio and the specific gravity, and deteriorate either the suitability for packaging or the suitability for recycling.

The specific gravity of the heat-shrinkable polypropylene shrink label film of the present invention is 0.94 or less. If the ratio is greater than 0.94, the specific gravity increases when the film is subjected to secondary processing such as printing.
The efficiency of the floating separation with the bottle becomes poor. Furthermore, at 40 ° C,
The shrinkage in the main shrinkage direction for 7 days is less than 3%, preferably less than 2%, particularly preferably less than 1%. 3
%, The film is liable to shrink during transportation and storage of the film, and the film is tightly tightened, thinned, etc., and the commercial value is significantly reduced. Furthermore, the film for a heat-shrinkable polypropylene shrink label of the present invention preferably has a lower tensile elastic modulus of 1000 MPa or more in either the machine direction (MD) or the orthogonal direction (TD). If it is less than 1000 MPa, the suitability for printing and the productivity in the label mounting step may decrease.

[II] Resin Composition The heat-shrinkable polypropylene shrink label film of the present invention comprises a polypropylene resin composition. Preferably, it is composed of a resin composition mainly composed of a crystalline polypropylene resin, particularly a crystalline propylene / α-olefin random copolymer (hereinafter, may be simply abbreviated as a random copolymer). Examples of the α-olefin constituting the random copolymer include ethylene and α-olefins having 4 to 20 carbon atoms, and it is preferable to use ethylene, butene-1, hexene-1, octene-1, and the like. Is preferred. The content of α-olefin is usually 2.0 to 30% by weight,
In particular, when the α-olefin is ethylene, 2.0 to
It is 10% by weight, preferably 2.0 to 6.0% by weight.
Two or more random copolymers having different monomer compositions may be mixed and used. The main component is a random copolymer,
The random copolymer itself may be used at 100%,
Furthermore, it means that other resins or general resin additives may be contained in a small amount. The case where an alicyclic hydrocarbon resin or the like is used in combination will be described later.

<Characteristics of Random Copolymer> The random copolymer preferably satisfies the following characteristics. Characteristics: Melt flow rate (MFR) MFR (230 ° C, 2.16 kg load) is 0.5 to 1
0 g / 10 min, preferably 1.0 to 10 g / 10 min. If the MFR is less than 0.5 g / 10 minutes, the extrusion characteristics may be deteriorated and the productivity may be reduced.
If the time is longer than 10 minutes, the shrinkage characteristics are deteriorated and the thickness becomes uneven.

[0012] Characteristics: The melting peak temperature (T _P) T _P obtained differential scanning calorimeter (DSC), 100~140 ℃, preferably 100-130
° C, more preferably 100 to 125 ° C. The T _P is less than 100 ° C., unstretched sheet is not easily cooled and solidified,
Film formation becomes difficult, while if it exceeds 140 ° C., shrinkage properties become insufficient.

Properties: Relationship between heat of fusion (ΔH _m ) and temperature The total heat of fusion of the random copolymer determined by DSC is ΔH _m
Where, the heat of fusion calculated from the low temperature side is ΔH _m of 5
When 0% to become when the temperature (℃) is defined as T _50, T ₅₀ ≦
125 ° C. T ₅₀ is preferably 120 ° C. or lower, more preferably 115 ° C. or lower. If T ₅₀ exceeds 125 ° C., the shrinkage properties deteriorate.

<Production of Random Copolymer>
The method for producing a crystalline propylene-α-olefin random copolymer satisfying the above condition is not limited, but it is preferable to carry out polymerization using a metallocene catalyst. Examples of the metallocene catalyst include the following systems, and (i) is particularly preferable. (I) a system comprising component (A), component (B) and, if necessary, component (C); (ii) component (A), component (D) and, if necessary, component (C). System (iii) System comprising component (A), component (E) and, if necessary, component (C) Hereinafter, each component constituting the metallocene catalyst will be described.

<Metallocene catalyst (i)> Component (A) comprises:
A metallocene transition metal compound represented by the following general formula (1)
Or (2). _{Q (C 5 H 4-a} R 1 a) (C 5 H 4-b R 2 b) MeXY (1) (C 5 H 4-a R 1 a) (C 5 H 4-b R 2 b) MeXY (2) _{[wherein, C 5 H 4-a R} 1 a and ^{_{C 5 H 4-b R 2}} b each represent a conjugated five-membered ring ligands, Q is two conjugated five-membered ring ligand A divalent hydrocarbon group having 1 to 20 carbon atoms, a silylene group having a hydrocarbon group having 1 to 20 carbon atoms, or a germylene group having a hydrocarbon group having 1 to 20 carbon atoms And Me represents zirconium or hafnium; X and Y each independently represent hydrogen, a halogen group, a hydrocarbon group having 1 to 20 carbon atoms,
0 alkoxy group, C1-20 alkylamide group, trifluoromethanesulfonic acid group, C1-20
A phosphorus-containing hydrocarbon group or a silicon-containing hydrocarbon group having 1 to 20 carbon atoms.

R ¹ and R ² are substituents on the conjugated five-membered ring ligand, and each independently represents a hydrocarbon group having 1 to 20 carbon atoms, a halogen group, an alkoxy group, a silicon-containing hydrocarbon. Group, a phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group or a boron-containing hydrocarbon group. Two adjacent R ¹ or two R ² may be bonded to each other to form a ring. a and b are integers satisfying 0 ≦ a ≦ 4 and 0 ≦ b ≦ 4. With the proviso that the two 5-membered ring ligands having R ¹ and R ² are, in terms of relative position via the group Q,
It is asymmetric with respect to the plane containing Me. ]

[0017] Q is as described above, a bonding group for cross-linking two conjugated five-membered ring ligand ^{_{C 5 H 4-a R 1}} a and ^{_{C 5 H 4-b R 2}} b, specifically Specifically, for example, (A) carbon number 1-2
0, preferably 1 to 6 divalent hydrocarbon groups, specifically, for example, an alkylene group, a cycloalkylene group, an arylene and the like, a (II) hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. Having a silylene group, (c) having 1 to 2 carbon atoms
There are 0, preferably 1 to 12, germylene groups having hydrocarbon groups.

Regardless of the number of carbon atoms, the distance between the two bonds of the divalent Q group is about 4 atoms or less, especially 3 atoms or less when Q is chain-like. In the case of having a cyclic group, it is preferred that the cyclic group is not more than about +2 atoms, particularly, the cyclic group alone. Therefore, in the case of an alkylene group, ethylene and isopropylidene (the distance between bonds is 2 atoms and 1 atom), in the case of a cycloalkylene group, cyclohexylene (the distance between bonds is only a cyclohexylene group) and in the alkylsilylene group, In this case, dimethylsilylene (the distance between bonds is 1 atom) is preferable. Me is titanium, zirconium or hafnium, preferably zirconium or hafnium.

X and Y may be each independently, that is, they may be the same or different; (a) hydrogen, (b) halogen (fluorine, chlorine, bromine or iodine, preferably chlorine), (c) carbon number 1 A hydrocarbon group having 1 to 20 carbon atoms, (d) an alkoxy group having 1 to 20 carbon atoms, (e) an alkylamide group having 1 to 20 carbon atoms, (f) a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms, (g) It represents a silicon-containing hydrocarbon group having 1 to 20 carbon atoms or a (thi) trifluoromethanesulfonic acid group.

R ¹ and R ² are substituents on the conjugated five-membered ring ligand, and each independently represents a hydrocarbon group having 1 to 20 carbon atoms, a halogen group, an alkoxy group having 1 to 20 carbon atoms. Group, silicon-containing hydrocarbon group having 3 to 20 carbon atoms, 2 carbon atoms
A phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group having 2 to 20 carbon atoms, or a boron-containing hydrocarbon group having 2 to 20 carbon atoms. Further, two adjacent R ¹ or two R ² may be bonded at the ω-terminal to form a ring together with a part of the cyclopentadienyl group. As a typical example of such a case, two adjacent R ¹ (or R ² ) on the cyclopentadienyl group share a double bond of the cyclopentadienyl group to form a fused six-membered ring. (Ie, an indenyl group and a fluorenyl group) and those forming a fused seven-membered ring (ie, an azulenyl group). a and b are 0 ≦ a ≦ 4, 0 ≦ b
It is an integer satisfying ≦ 4.

Non-limiting examples of the metallocene compound represented by the general formula (1) include the following. In addition, these compounds are indicated by only chemical names, but needless to say, the three-dimensional structure has the asymmetry referred to in the present invention. Although only the case where zirconium is used as Me is exemplified, hafnium may be directly substituted instead.

A transition metal compound having two silylene-bridged five-membered ring ligands, for example, (1) dimethylsilylenebis (1
-Indenyl) zirconium dichloride, (2) dimethylsilylenebis {1- (2-methyl-4-phenyl-4)
H-azulenyl) {zirconium dichloride, (3) dimethylsilylenebis [1- {2-methyl-4- (1-naphthyl) indenyl}] zirconium dichloride,
(4) methylphenylsilylenebis {1- (2,4-dimethylindenyl)} zirconium dichloride, (5)
Methylphenylsilylenebis [1- {2-methyl-4-
(1-naphthyl) indenyl}] zirconium dichloride,

(6) Dimethylsilylenebis {1- (2-)
Methyl-4-phenylindenyl) zirconium dimethyl, (7) dimethylsilylene bis {1- (2-ethyl-4-phenyl-4H-azulenyl)} zirconium dichloride, (8) dimethylsilylene} 1- (2-ethyl -4-phenyl-4,5,6,7,8-pentahydroazulenyl) {1- (2,3,5-trimethylcyclopentadienyl)} zirconium dichloride, (9) dimethylsilylenebis {1- (2-ethyl-4- (pentafluorophenyl) indenyl)} zirconium dichloride and the like.

A five-membered ring ligand bridged with an alkylene group is
Transition metal compounds having, for example, (1) ethylene-
1,2-bis (1-indenyl) zirconium dichloride, (2) ethylene-1,2-bis {1- (2,4-dimethylindenyl)} zirconium dichloride, (3)
Ethylene-1,2-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, (4) ethylene-1,2-bis {1- (2-methyl-4,5-benzoindenyl) )} Zirconium dichloride, (5) ethylene-1,2-bis [1- {2-methyl-4- (4-
Chlorophenyl) -4H-azulenyl}] zirconium dichloride.

A transition metal compound having a five-membered ring ligand bridged by a hydrocarbon residue containing germanium, aluminum, boron, phosphorus or nitrogen, for example, (1) dimethylgermylene bis (1-indenyl) zirconium dichloride, (2) dimethylgermylenebis {1- (2-methyl-4-phenyl-4H-azulenyl)} zirconium dichloride, (3) dimethylgermylenebis {1- (2)
-Methyl-4,5-benzoindenyl) zirconium dichloride, (4) phenylphosphinobis (1-indenyl) zirconium dichloride, (5) phenylaminobis (1-indenyl) zirconium dichloride and the like. Among these complexes, particularly preferred are complexes having an azulene skeleton.

As the metallocene transition metal compound represented by the general formula (2), the following compounds can be exemplified. (1) bis (1-indenyl) zirconium dichloride, (2) bis {1- (2-methyl-4-phenyl-4)
H-azulenyl) {zirconium dichloride, (3) bis [1- {2-methyl-4- (1-naphthyl) indenyl}] zirconium dichloride, (4) bis {1-
(2,4-dimethylindenyl)} zirconium dichloride, (5) bis [1,1 ′-{2-methyl-4- (4
-Chlorophenyl) -4H-azulenyl}] zirconium dichloride

(6) Bis [1,1 '-{2-methyl-4 "
-(4-chloro-2-naphthyl) -4H-azulenyl}] zirconium dichloride (7) bis {1,1 '-(2-ethyl-4-phenyl-
4H-azulenyl) zirconium dichloride (8) bis {1,1 '-(2-methyl-4-phenylhexahydroazulenyl)} zirconium dichloride (9) bis [1,1'-{2-methyl-4- (4-chlorophenyl) hexahydroazulenyl}] zirconium dichloride (10) bis [1,1 ′-{2-methyl-4- (4-chloro-2-naphthyl) hexahydroazulenyl}] zirconium dichloride (11) Bis (1-fluorenyl) zirconium dichloride, (12) bis {1- (2-methyl-4-phenyl-4H-fluorenyl)} zirconium dichloride. Here, only the case of zirconium as Me has been exemplified, but instead, hafnium can be directly substituted and named.

Component (B) is an ion-exchangeable phyllosilicate. The ion-exchangeable phyllosilicate is a silicate compound having a crystal structure in which planes formed by ionic bonds and the like are stacked in parallel with a weak bonding force, and refers to a contained ion-exchangeable silicate. Most ion-exchanged phyllosilicates occur naturally mainly as a main component of clay minerals, but these ion-exchanged phyllosilicates are not limited to those of natural origin but are artificially synthesized. You may. Specific examples include kaolins such as dickite, nacrite, kaolinite, anorthite, metahalloysite, halloysite, serpentine groups such as chrysotile, risaludite, antigorite, montmorillonite, zaukonite, beidellite, nontronite, saponite, Smectites such as hectorite and stevensite, vermiculites such as vermiculite, mica, illite, sericite, mica such as sea green stone, attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, and chlorite. Can be These may form a mixed layer.

Among these, montmorillonite, zaukonite, beidellite, nontronite, saponite,
Smectites such as hectorite, stevensite, bentonite and teniolite, vermiculites and mica are preferred. When a compound having a radius of 20 angstroms or more and a pore volume of less than 0.1 cc / g measured by a mercury intrusion method is used as component B, a high polymerization activity tends to be difficult to obtain. / G or more,
In particular, those having 0.3 to 5 cc / g are preferable. Component B can be used as it is without any particular treatment, but it is also preferable to subject component B to a chemical treatment. Here, the chemical treatment may be any of a surface treatment for removing impurities adhering to the surface and a treatment that affects the structure of the clay.

Specific examples include acid treatment, alkali treatment, salt treatment, and organic substance treatment. The acid treatment increases the surface area by removing impurities on the surface and eluting cations such as Al, Fe, and Mg in the crystal structure.
Alkali treatment destroys the crystal structure of the clay, resulting in a change in the structure of the clay. In salt treatment and organic matter treatment,
An ion complex, a molecular complex, an organic derivative, or the like can be formed to change a surface area or an interlayer distance. By replacing the exchangeable ions between the layers with another large bulky ion by utilizing the ion exchange property, a layered material in which the layers are expanded can be obtained. That is, the bulky ions play a pillar-like role of supporting the layered structure, and are called pillars. Introducing another substance between layered substance layers is called intercalation.

As the guest compound to be intercalated, cationic inorganic compounds such as TiCl ₄ and ZrCl ₄ , Ti (OR) ₄ , Zr (OR) ₄ , PO (OR) ₃ ,
Metal alcoholates such as B (OR) ₃ [R is alkyl, aryl, etc.], [Al ₁₃ O ₄ (OH) ₂₄ ] ₇₊ , [Zr ₄ (O
H) ₁₄ ] ₂₊ , and metal hydroxide ions such as [Fe ₃ O (OCOCH ₃ ) ₆ ] ₊ . These compounds may be used alone or in combination of two or more.
When intercalating these compounds, Si
A polymer obtained by hydrolyzing a metal alcoholate such as (OR) ₄ , Al (OR) ₃ , Ge (OR) _{4, and} a colloidal inorganic compound such as SiO ₂ can also be present. Examples of pillars include oxides formed by intercalating the hydroxide ions between layers and then heating and dehydrating. Component B may be used as it is, or may be used after heat dehydration treatment. Further, they may be used alone or as a mixture of two or more of the above solids.

As the ion-exchange layered silicate, at least 40%, preferably 6%, of the exchangeable Group 1 metal cations contained in the ion-exchange layered silicate before being treated with salts.
0% or more of a cation dissociated from the following salts,
Preferably, ion exchange is performed. The salt used in the salt treatment for the purpose of ion exchange is a compound containing a cation containing at least one atom selected from the group consisting of Group 2 to 14 atoms,
A compound comprising a cation containing at least one atom selected from the group consisting of Group 14 atoms and at least one anion selected from the group consisting of halogen atoms, inorganic acids and organic acids, more preferably , A cation containing at least one atom selected from the group consisting of Group 2-14 atoms, Cl, Br, I, F, PO ₄ , SO ₄ , NO
₃ , CO ₃ , C ₂ O ₄ , OCOCH ₃ , CH ₃ COCHCOC
H ₃ , OCl ₃ , O (NO ₃ ) ₂ , O (ClO ₄ ) ₂ , O (S
O ₄ ), OH, O ₂ Cl ₂ , OCl ₃ , OCOH, OCOC
It is a compound comprising at least one anion selected from the group consisting of H ₂ CH ₃ , C ₂ H ₄ O ₄ and C ₆ H ₅ O ₇ .

Specifically, CaCl_Two, CaSO_Four, Ca
C_TwoO_Four, Ca (NO_Three)_Two, Ca_Three(C₆H_FiveO₇)_Two, Mg
Cl_Two, Sc (OCOCH_Three)_Two, ScF_Three, ScBr_Three,
Y (OCOCH_Three)_Three, LaPO_Four, La_Two(SO_Four)_Three, S
m (OCOCH_Three)_Three, SmCl_Three, Yb (NO_Three)_Three, Y
b (ClO_Four)_Three, Ti (OCOCH_Three)_Four, Ti (C
O_Three)_Two, Ti (SO_Four)_Two, TiF_Four, TiCl_Four, Zr
(OCOCH_Three)_Four, Zr (CO_Three)_Two, Zr (NO_Three)_Four,
ZrOCl_Two, Hf (SO_Four)_Two, HfBr_Four, HfI_Four,
V (CH_ThreeCOCHCOCH_Three)_Three, VOSO_Four, VC
l_Four, VBr_Three, Nb (CH _ThreeCOCHCOCH_Three)_Five, N
b_Two(CO_Three)_Five, Ta_Two(CO_Three)_Five, Ta (NO)_Five, T
aCl_Five, Cr (OOCH_Three)_TwoOH, Cr (NO_Three)_Three,
Cr (ClO_Four)_Three, MoOCl_Four, MoCl_Three, MoCl
_Four, MoCl_Five, MoF₆, WCl_Four, WBr_Five, Mn (C
H_ThreeCOCHCOCH_Three)_Two, Mn (NO_Three)_Two, Fe (O
COCH_Three)_Two, Fe (NO_Three)_Three, FeSO_Four, Co (O
COCH_Three)_Two, Co_Three(PO_Four)_Two, CoBr_Two, NiCO
_Three, NiC_TwoO_Four, Pb (OCOCH_Three)_Four, Pb (OOC
H_Three)_Two, PbCO_Three, Pb (NO_Three)_Two, CuI_Two, CuB
r_Two, CuC_TwoO_Four, Zn (OOCH_Three)_Two, Zn (CH_ThreeC
OCHCOCH_Three)_Two, Cd (OCOCH_TwoCH_Three)_Two, C
dF_Two,, AlCl_Three, Al_Two(C_TwoO_Four)_Three, Al (CH_Three
COCHCOCH_Three)_Three, GeCl_Four, GeBr_Four, Sn
(OCOCH_Three)_Four, Sn (SO_Four)_TwoAnd the like.

In addition to removing impurities on the surface, the acid treatment can elute a part or all of cations such as Al, Fe and Mg having a crystal structure. The acid used in the acid treatment is preferably selected from hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, phosphoric acid and acetic acid. The salt and the acid used for the treatment may be two or more. When combining the salt treatment and the acid treatment, after performing the salt treatment, a method of performing an acid treatment,
There is a method of performing a salt treatment after performing the acid treatment, and a method of simultaneously performing the salt treatment and the acid treatment.

The treatment conditions with salts and acids are not particularly limited, but usually, the concentration of salts and acids is 0.1 to 3
0% by weight, treatment temperature is from room temperature to boiling point, treatment time is from 5 minutes to
It is preferable to select the condition for 24 hours and to elute at least a part of at least one compound contained in the ion-exchange layered silicate. Further, salts and acids are generally used in an aqueous solution.

In the salt treatment and / or the acid treatment, the shape may be controlled by pulverization or granulation before, during, or after the treatment. Further, a chemical treatment such as an alkali treatment or an organic substance treatment may be used in combination. These ion-exchange layered silicates usually contain adsorbed water and interlayer water. In the present invention, it is preferable to remove these adsorbed water and interlayer water to use as component B.

Here, the adsorbed water is water adsorbed on the surface of the compound particles of the ion-exchangeable layered silicate or on the crystal fracture surface, and the interlayer water is water existing between the layers of the crystal. In the present invention, these adsorbed water and / or interlayer water can be removed by heat treatment before use. The method of heat treatment of the adsorbed water and interlayer water of the ion-exchanged layered silicate is not particularly limited, and methods such as heat dehydration, heat dehydration under gas flow, heat dehydration under reduced pressure, and azeotropic dehydration with an organic solvent are used. Can be The temperature at the time of heating cannot be specified unconditionally because it depends on the types of ion-exchanged layered silicate and interlayer ions. However, the temperature is 100 ° C. or higher, preferably 150 ° C. or higher, so that interlayer water does not remain. Is not preferable (for example, 800 ° C. or higher, depending on the heating time). Further, a heat dehydration method for forming a crosslinked structure such as heating under air flow is not preferable because the polymerization activity of the catalyst is reduced. The heating time is at least 0.5 hour, preferably at least 1 hour. At this time, component B after removal
Is preferably 3% by weight or less, more preferably 1% by weight or less, assuming that the moisture content when dehydrated for 2 hours at a temperature of 200 ° C. and a pressure of 1 mmHg is 0% by weight.

As the component B, it is preferable to use spherical particles having an average particle diameter of 5 μm or more. More preferably, spherical particles having an average particle size of 10 μm or more are used. More preferably, spherical particles having an average particle diameter of 10 μm or more and 100 μm or less are used. The average particle size here is represented by a number average particle size calculated by performing image processing on an optical microscope photograph (100 times magnification) of the particles. Component B may be a natural product or a commercially available product as long as the shape of the particles is spherical.
Particles in which the shape and particle size of the particles are controlled by a particle diameter, a separation, or the like may be used.

The granulation methods used here include, for example, stirring granulation, spray granulation, tumbling granulation, briquetting, compacting, extrusion granulation, fluidized bed granulation, and emulsion granulation. , A submerged granulation method, a compression molding granulation method and the like, but are not particularly limited as long as the component B can be granulated. The granulation method is preferably a stirring granulation method, a spray granulation method, a tumbling granulation method, or a fluidized bed granulation method, and particularly preferably a stirring granulation method or a spray granulation method. When spray granulation is performed, water or an organic solvent such as methanol, ethanol, chloroform, methylene chloride, pentane, hexane, heptane, toluene, or xylene is used as a dispersion medium for the raw material slurry. Preferably, water is used as the dispersion medium. The concentration of the component B in the raw slurry liquid for spray granulation to obtain spherical particles is 0.1 to 70%, preferably 1 to 50%.
%, Particularly preferably 5 to 30%. The temperature of the inlet of the hot air for spray granulation from which spherical particles can be obtained varies depending on the dispersion medium, but when water is used as an example, the temperature is 80 to 260 ° C., preferably 1 to 260 ° C.
Perform at 00-220 ° C.

At the time of granulation, an organic substance, an inorganic solvent, an inorganic salt, and various binders may be used. Examples of the binder used include sugar, dextrose, corn syrup, gelatin, glue, carboxymethyl celluloses, polyvinyl alcohol, water glass, magnesium chloride, aluminum sulfate, aluminum chloride, magnesium sulfate, alcohols, glycol, starch, casein,
Latex, polyethylene glycol, polyethylene oxide, tar, pitch, alumina sol, silica gel,
Gum arabic, sodium alginate and the like can be mentioned.

The spherical particles obtained as described above preferably have a compressive breaking strength of 0.2 MPa or more in order to suppress crushing and fine powder in the polymerization step. In the case of such a particle strength, the effect of improving the particle properties is effectively exhibited, particularly when prepolymerization is performed.

As the organoaluminum compound (component C) used as an optional component in addition to the components A and B, a compound represented by the following general formula (3) is suitable. The ^{_{(AlR 3 n X 3-n}} ) m (3) in the present invention compound represented by the formula alone, can be used in or in combination as a mixture of two or more. Also,
This use is possible not only at the time of catalyst preparation but also at the time of prepolymerization or polymerization. In this formula, R ³ has 1 to 20 carbon atoms.
X represents a halogen, hydrogen, an alkoxy group, or an amino group. n is an integer of 1-3 and m is an integer of 1-2. R ³ is preferably an alkyl group.
Is preferably chlorine when it is halogen, alkoxy group having 1 to 8 carbon atoms when it is an alkoxy group, and amino group having 1 to 8 carbon atoms when it is an amino group. Therefore, specific examples of preferred compounds include trimethylaluminum, triethylaluminum, trinormal propyl aluminum, trinormal butyl aluminum,
Triisobutyl aluminum, tri normal hexyl aluminum, tri normal octyl aluminum, tri normal decyl aluminum, diethyl aluminum chloride, diethyl aluminum sesquichloride, diethyl aluminum hydride, diethyl aluminum ethoxide, diethyl aluminum dimethyl amide, diisobutyl aluminum hydride, diisobutyl aluminum chloride, etc. Is mentioned. Of these, preferred are m = 1, n = 3 trialkylaluminum and dialkylaluminum hydride. More preferably, R ³ is a trialkyl aluminum having 1 to 8 carbon atoms.

<Metallocene Catalyst (ii)> Another example of the metallocene catalyst used in the present invention is a catalyst obtained by combining the above metallocene transition metal compound (component A) with an aluminum oxy compound (component D). Also in this case, as an optional component, an organoaluminum compound (component C)
Can be used in combination. Specific examples of the aluminum oxy compound (component D) include the following general formula (4):
Compounds represented by (5) and (6) are mentioned.

[0044]

Embedded image

In the above formulas, R ⁴ represents a hydrogen atom or a hydrocarbon residue, preferably a hydrocarbon residue having 1 to 10 carbon atoms, more preferably a hydrocarbon residue having 1 to 6 carbon atoms. In addition, a plurality of R ⁴
May be the same or different. Also, p is 0
And an integer of 2 to 30, preferably 2 to 30.

The compounds represented by the general formulas (4) and (5) are also called alumoxanes and are obtained by reacting one kind of trialkylaluminum or two or more kinds of trialkylaluminums with water. Specifically, (a) methylalumoxane, ethylalumoxane, propylalumoxane, butylalumoxane, isobutylalumoxane obtained from one type of trialkylaluminum and water, (b) two types of trialkylaluminum and Examples thereof include methylethylalumoxane, methylbutylalumoxane, and methylisobutylalumoxane obtained from water. Of these, methylalumoxane or methylisobutylalumoxane is preferred.

The compound represented by the general formula (6) can be prepared by mixing one kind of trialkylaluminum or two or more kinds of trialkylaluminums with an alkylboronic acid represented by the following general formula (7): It can be obtained by a 1: 1 (molar ratio) reaction. In the general formula (7), R ⁵ represents a hydrocarbon residue having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms or a halogenated hydrocarbon group. R ⁵ B (OH) ₂ (7) Specifically, the following reaction products can be exemplified. (A) Trimethylaluminum and methylboronic acid 2:
(B) 2: 1 reaction product of triisobutylaluminum and methylboronic acid (c) 1: 1: 1 reaction product of trimethylaluminum, triisobutylaluminum and methylboronic acid (d) 2: 2 reaction of trimethylaluminum and methylboronic acid
1 Reactant (e) Triethylaluminum and butylboronic acid 2:
1 reactant

<Metallocene Catalyst (iii)> As another example of the metallocene catalyst used in the present invention, the metallocene-based transition metal compound (component A) is reacted with component A to form stable ions. And a catalyst combined with a specific compound (component E). Also in this case, an organic aluminum compound (component C) can be used in combination as an optional component.

The specific compound (E) is an ionic compound formed from an ion pair of a cation and an anion, or an electrophilic compound, and reacts with a metallocene compound to form a stable ion to form a polymerization active species. To form. Among them, the ionic compound is represented by the general formula (8). [Q '] ^{m +} [Y] ^m- (m is an integer of 1 or more) (8) In the formula, Q ′ is a cation component of an ionic compound, and examples thereof include a carbonium cation, a tropylium cation, an ammonium cation, an oxonium cation, a sulfonium cation, and a phosphonium cation.
Metal cations and organic metal cations which are themselves easily reduced can also be mentioned. These cations
Not only a cation capable of giving a proton as disclosed in Japanese Patent Publication No.
A cation that does not give a proton may be used. Specific examples of these cations include triphenylcarbonium, diphenylcarbonium, cycloheptatrienium, indenium, triethylammonium, tripropylammonium, tributylammonium, NNdimethylammonium, dipropylammonium, dicyclohexylammonium, triphenylphosphonium, Trimethylphosphonium, tri (dimethylphenyl) phosphonium, tri (methylphenyl) phosphonium, triphenylsulfonium, triphenyloxonium, triethyloxonium, pyrylium, silver ion, gold ion, platinum ion, palladium ion, mercury ion, ferro A cerium ion and the like.

Y is an anionic component of an ionic compound, which is a component which reacts with a metallocene compound to form a stable anion, such as an organic boron compound anion, an organic aluminum compound anion, an organic gallium compound anion, and an organic phosphorus compound. Anions, organic arsenic compound anions, organic antimony compound anions and the like can be mentioned. Specifically, tetraphenylboron, tetrakis (3,
4,5-trifluorophenyl) boron, tetrakis (3,5-di (trifluoromethyl) phenyl) boron, tetrakis (3,5- (t-butyl) phenyl) boron, tetrakis (pentafluorophenyl) boron,
Tetraphenylaluminum, tetrakis (3,4,5
-Trifluorophenyl) aluminum, tetrakis (3,5-di (trifluoromethyl) phenyl) aluminum, tetrakis (3,5-di (t-butyl) phenyl) aluminum, tetrakis (pentafluorophenyl) aluminum, tetraphenylgallium , Tetrakis (3,4,5-trifluorophenyl) gallium, tetrakis (3,5-di (trifluoromethyl) phenyl) gallium, tetrakis (3,5-di (t-butyl)
Phenyl) gallium, tetrakis (pentafluorophenyl) gallium, tetraphenylphosphorus, tetrakis (pentafluorophenyl) phosphorus, tetraphenylarsenic, tetrakis (pentafluorophenyl) arsenic, tetraphenylantimony, tetrakis (pentafluorophenyl) antimony, decaborate, Undecaborate, carbado decaborate, decachloro decaborate and the like can be mentioned.

As the electrophilic compound, among compounds known as Lewis acid compounds, those which react with a metallocene compound to form stable ions to form polymerization active species, and include various metal halides Examples include compounds and metal oxides known as solid acids. Specific examples include magnesium halides and Lewis acidic inorganic compounds. These catalyst components can be used by being appropriately supported on an inorganic solid carrier, an organic solid carrier, or the like.
Examples of loading are described in JP-A-61-296008, JP-A-1-101315 and JP-A-5-301917.

<Formation of Catalyst> Component A, component B, and
It can be prepared by contacting the metallocene catalyst comprising component C, which is used if necessary, in a polymerization tank or outside the polymerization tank in the presence or absence of the monomer to be polymerized. Component A and component D or component E
The catalyst can be prepared in the same manner also in the case of combining. Further, the catalyst may be one obtained by performing prepolymerization in the presence of an olefin. As the olefin used for the prepolymerization, propylene, ethylene, 1-butene, 3-olefin
Methylbutene-1, styrene, divinylbenzene and the like are used.

<Polymerization> The polymerization of the crystalline propylene-α-olefin random copolymer used in the present invention is carried out by reacting the catalyst prepared as described above with propylene and ethylene or an α-olefin having 4 to 20 carbon atoms. It is performed by mixing and contacting. The amount ratio of each monomer in the reaction system does not need to be constant over time, and it is convenient to supply each monomer at a constant mixing ratio, and to change the mixing ratio of the supplied monomers over time. Is also possible. Further, any of the monomers can be dividedly added in consideration of the copolymerization reaction ratio.

As the polymerization mode, any method can be adopted as long as the catalyst component and each monomer are efficiently contacted. Specifically, a slurry method using an inert solvent, a bulk method using propylene as a solvent without substantially using an inert solvent, a solution method, or substantially converting each monomer into a substantially gaseous state without using a substantially liquid solvent A keeping gas phase method can be employed. Either continuous polymerization or batch polymerization may be used. In the case of slurry polymerization, a single or a mixture of saturated aliphatic or aromatic hydrocarbons such as hexane, heptane, pentane, cyclohexane, benzene, and toluene can be used as a polymerization solvent.

As the polymerization conditions, the polymerization temperature is -78 to 16
The temperature is 0 ° C., preferably 0 to 150 ° C., and hydrogen may be used as a molecular weight regulator at that time. The polymerization pressure is from 0 to 90 kg / cm ² · G, preferably from 0 to 60 kg / cm ² · G, particularly preferably from 1 to 50 k / cm ² · G.
g / cm ² · G.

[III] Combination of Random Copolymer and Other Resin A preferred alicyclic hydrocarbon resin to be used in combination with the crystalline propylene / α-olefin random copolymer is an alicyclic hydrocarbon resin. For example, petroleum resins, terpene resins, rosin-based resins, coumarone-indene resins, and hydrogenated derivatives thereof are suitable. Among them, those having no polar group, or 95
% Is preferred. More preferred resins are petroleum resins or hydrogenated derivatives of petroleum resins, such as Arakawa Chemical Industries, Ltd.
And commercially available products such as Alcon manufactured by Tonex Inc. and Escolets manufactured by Tonex.

The softening point of the alicyclic hydrocarbon resin is usually 1
The temperature is 10 ° C. or higher, preferably 115 ° C. or higher, and more preferably 125 ° C. or higher. If the softening point is lower than this, the film may be sticky or may become cloudy due to aging. .

The mixing ratio of the alicyclic hydrocarbon resin is such that the crystalline propylene / α-olefin random copolymer is 50 to 50%.
100% by weight, preferably 60 to 90% by weight, and the alicyclic hydrocarbon resin is 0 to 50% by weight, preferably 10 to 40% by weight. It is appropriately determined in consideration of the film stickiness, moldability, and the like.

As other components, there are various compounding modes as long as the effects of the present invention are not impaired. For example, antioxidants, antistatic agents, neutralizing agents, nucleating agents, antiblocking agents, slip agents, and the like can be added. Further, for the purpose of further improving the shrinkage characteristics, a known component for improving the shrinkage characteristics such as a propylene-butene-1 copolymer, polybutene-1, and a linear low-density polyethylene may be added.

[IV] Method of Forming Shrink Label Film The heat-shrinkable polypropylene shrink label film of the present invention can be obtained by subjecting the above polypropylene resin composition to a known forming method such as an inflation method or a flat stretching method. Although it can be molded using, in the present invention,
It is preferable to use a flat stretching method, particularly a tenter type uniaxial stretching method.

After being melt-extruded by the above-mentioned molding method, the film is stretched at least twice in at least one axial direction by a known method to produce the shrink label film of the present invention.
The stretching direction may be uniaxial or more, but it is preferable to uniaxially stretch only in a direction perpendicular to the flow direction of the label. On the other hand, if the stretching ratio is less than 2, a sufficient shrinkage cannot be obtained. Further, for the purpose of improving the shrinkage, it is preferable to perform stretching at a temperature as low as possible. In particular, when there is a step of applying preheating to the unstretched sheet, the preheating temperature is set as low as possible within a moldable range. This is preferable from the viewpoint of improving the shrinkage.

The thickness of the shrink label film of the present invention is not particularly limited, but is 100 μm or less, preferably 30 to 80 μm. Further, the film for shrink labels of the present invention can be used as a film for a single-layer label or as a film for a multilayer label having two or more layers. In the case of a multilayer label film, the label film from the resin composition of the present invention may have at least one layer. Examples of the laminating method include a multi-layer co-extrusion method and a dry lamination method, but a multi-layer co-extrusion method is particularly preferable.
The thickness of the substrate layer (I) composed of the resin composition of the present invention is 50 to 99% of the total film thickness, and the surface layer (II) is provided on one or both sides of the substrate layer (I) with a total film thickness of 1%. ~ 50%
It is preferable to laminate. If the thickness of the surface layer (II) exceeds 50% of the total film thickness, the rigidity of the film may decrease. Upon lamination, it is desirable to select a resin composition to be laminated on the surface layer (II) according to the purpose. For example, when the purpose is to improve the balance between transparency and antiblocking properties by lamination, a propylene / ethylene random copolymer or a propylene / ethylene / butene-1 random copolymer or a propylene homopolymer is mainly used, It is desirable to laminate a resin composition to which a blocking agent has been added. For the purpose of further improving the shrinkage characteristics, it is desirable to laminate a resin composition mainly composed of the resin of the following [A] group, and among the “A” group, a linear low density polyethylene (Nippon Polychem Co., Ltd.) Particularly, an amorphous olefin polymer (such as "Apel" manufactured by Mitsui Chemicals, Inc.) or the like is particularly desirable. In addition, the surface layer (I
It is desirable to add an anti-blocking agent to the resin composition used in I). When an antiblocking agent is added to the surface layer (II), it is desirable not to add the antiblocking agent to the substrate layer (I) from the viewpoint of improving transparency. [A] group linear low-density polyethylene, low-density polyethylene, polybutene-1, propylene / butene-1 random copolymer,
Ethylene / propylene random copolymer, ethylene / butene-1 random copolymer, ethylene / hexene-1 random copolymer, amorphous olefin polymer

[V] Use of heat-shrinkable film The heat-shrinkable polypropylene shrink label film of the present invention has a significantly improved heat shrinkage, and is therefore a material for a display label for PET bottles and a display label for bottle containers. It has practical characteristics as a material for use. Further, since the low-temperature shrinkage rate is improved, the high-speed label packaging property is excellent, and particularly, it can be suitably used for label packaging in PET bottles and bottle containers preliminarily filled at low temperature. In addition, since a low specific gravity of 0.94 or less is achieved, a polypropylene-based heat-shrinkable shrink label film having an improved balance between shrink packaging suitability and recycling efficiency can be provided.
Furthermore, the heat-shrinkable polypropylene shrink label film of the present invention has high mechanical strength (tensile elastic modulus), and thus can exhibit secondary workability and sufficient film rigidity in the label mounting step.

[0064]

EXAMPLES The present invention will be specifically described with reference to examples below, but the present invention is not limited to these examples. The method for producing the propylene / α-olefin random copolymer, the method for producing the label film, and the method for evaluating the film used in the examples and comparative examples are as follows.

[I] Production method of propylene / α-olefin random copolymer (1) Preparation of solid catalyst component (i) Dimethylsilylene bis [1- {2-methyl-4-
(4-Chlorophenyl) -4H-azulenyl}] Synthesis of Racemic Form of Zirconium Dichloride (a) Synthesis of Racemic / Meso Mixture 1.84 g of 1-bromo-4-chlorobenzene (9.6 m
mol) of n-hexane (10 ml) and diethyl ether (10 ml) at -78 ° C in 11.7 ml of a pentane solution of t-butyllithium (1.64 M) (19.
2 mmol) was added dropwise. The resulting solution was treated at -5 ° C with 1.
After stirring for 5 hours, 1.2 g of 2-methylazulene was added to the solution.
(8.6 mmol) was added to carry out the reaction. The reaction solution was stirred for 1.5 hours while gradually returning to room temperature.
Thereafter, the reaction solution was cooled to 0 ° C., and 15 μl (0.19 mmol) of 1-methylimidazole was added.
0.52 ml of dichlorodimethylsilane (4.3 mmo
l) was added. After stirring the reaction solution at room temperature for 1.5 hours,
The reaction was stopped by adding dilute hydrochloric acid, the separated organic phase was concentrated under reduced pressure, dichloromethane was added, and the mixture was dried over magnesium sulfate. After evaporating the solvent under reduced pressure, the residue was purified by silica gel column chromatography to obtain 2.1 g of an amorphous solid. Next, the reaction product 1.
27 g was dissolved in 15 ml of diethyl ether, and-
At 78 ° C., an n-hexane solution of n-butyllithium (1.
2.8 ml (4.5 mmol) of 66M) were added dropwise. After completion of the dropwise addition, the reaction solution was stirred for 12 hours while gradually returning to room temperature. After distilling off the solvent under reduced pressure, 5 ml of a mixed solvent of toluene and diethyl ether (40: 1) was added, and the mixture was cooled to -78 ° C.
3 g (2.3 mmol) were added. Thereafter, the temperature was immediately returned to room temperature, and the mixture was stirred at room temperature for 4 hours to carry out a reaction. The obtained reaction solution was filtered over celite, and the solid separated by filtration was washed with 3 ml of toluene and collected. The collected solid was extracted with dichloromethane, the solvent was distilled off from the extract, and 906 mg of a racemic / meso mixture of dimethylsilylenebis [1- {2-methyl-4- (4-chlorophenyl) -4H-azulenyl}] zirconium dichloride. (56% yield). (B) Purification of racemic body Further, 900 mg of the above-mentioned racemic / meso mixture was dissolved in 20 ml of dichloromethane, and a 100 W high-pressure mercury lamp was used.
By irradiating for 0 minutes, the ratio of the racemate was increased, and then the insoluble matter was removed by filtration, and the collected filtrate was concentrated to dryness. Then, the obtained solid component was stirred with 22 ml of toluene, and after standing, the supernatant was removed.
This was repeated twice, and the remaining solid component was dried to obtain 275 mg of a racemic dimethylsilylenebis [1- {2-methyl-4- (4-chlorophenyl) -4H-azulenyl}] zirconium dichloride. (Ii) Chemical treatment of clay mineral 218.1 g of sulfuric acid (96%) and magnesium sulfate 13
A commercially available montmorillonite (Kunimine Kogyo, Knipia F) 20 was added to an aqueous solution obtained by mixing 0.4 g of the mixture with 909 ml of demineralized water.
0.03 g was dispersed and stirred at 100 ° C. for 2 hours. This montmorillonite water slurry was used to obtain a solid concentration of 12%.
And subjected to spray granulation with a spray drier to obtain particles. Thereafter, the particles were dried under reduced pressure at 200 ° C. for 2 hours. (Iii) Preparation of catalyst component 230 ml of dehydrated and deoxygenated heptane after sufficiently replacing the inside of a 1-liter stirred autoclave with propylene.
Was introduced, and the temperature in the system was maintained at 40 ° C. Here, 10 g of chemically treated clay slurried with toluene was added. Further, in a separate container, 0.15 mmol of racemic dimethylsilylenebis [1- {2-methyl-4- (4-chlorophenyl) -4H-azulenyl}] zirconium dichloride and 1.5 mmol of triisobutylaluminum mixed under toluene. Was added. Where propylene is 1
Introduced at a rate of 0 g / h for 120 minutes, and then polymerization was continued for 120 minutes. Further, the solvent was removed and dried under nitrogen to obtain a solid catalyst component. This solid catalyst component is 1 g of a solid component.
Per 1.9 g of polypropylene.

(2) Polymerization After sufficiently replacing the inside of the stirred autoclave having an internal volume of 200 l with propylene, the liquefied propylene 4 was sufficiently dehydrated.
5 kg were introduced. To this were added 500 ml (0.12 mol) of a triisobutylaluminum / n-heptane solution, 2.0 kg of ethylene, and 3.5 l of hydrogen (as a standard state volume), and the internal temperature was maintained at 30 ° C. Then, 1.45 g of the solid catalyst component was injected with argon to start polymerization, and the temperature was raised to 70 ° C. over 30 minutes, and the temperature was maintained for 1 hour. Here, 100 ml of ethanol was added to stop the reaction. The residual gas was purged to obtain 13.7 kg of a propylene / ethylene random copolymer (PP). A required amount of a propylene-ethylene random copolymer was obtained in the same manner as a sample. The obtained propylene-ethylene random copolymer had the following physical properties. MFR: 2.58 g / 10 min, ethylene content: 3.
42 _{wt%, T p: 122.7 ℃,} T 50: 113 ℃.

[II] Production Method of Label Film (i) Formation of Unstretched Sheet The resin composition for the base material layer (I) was prepared from a 75 mm single screw extruder using a 30 mm single screw extruder and a 20 mm single screw extruder. Each of the resin compositions for both surface layers (II) at 240 ° C.
It is melt coextruded to a predetermined thickness by a T-die method, cooled and solidified by a cooling roll at 15 ° C.
An unstretched sheet of 0 μm was obtained. (Ii) Forming of a stretched film The unstretched sheet obtained above is introduced into a tenter furnace, and is preheated at a minimum moldable temperature for 30 seconds. 6.5 over seconds
And then 7.5 times in the width direction in the tenter furnace.
Annealing was performed at 87 ° C. for 30 seconds while being relaxed by 30% to obtain a heat-shrinkable shrink label film having a draw ratio of 6 and a thickness of 50 μm.

[III] Evaluation method for label film (1) Suitability for packaging A label film was cut out in a length of 22.5 cm in the main shrink direction and 20 cm in a direction perpendicular to the main shrink direction. A cylindrical label was obtained by rounding into a cylindrical shape with a circumferential length of 21.5 cm so that the main shrinkage direction was the circumferential direction, and heat-sealing the overlapping portion. One end of the obtained label and a commercially available plastic bottle (500 ml, Kirin Beverage Su
(for pli) so that the lower ends are aligned. Put 500 ml of water (25 ° C.) into the plastic bottle with the label attached,
After capping, it was immersed in a water bath adjusted to 90 ° C. for 5 seconds. Immediately after the elapse of 5 seconds, the label was packaged by taking it out of the 90 ° C. water bath and immersing it in a separately prepared 25 ° C. water bath for 1 minute or more. A 15.7 cm portion from the lower end of the plastic bottle after label packaging (upper label position of a commercially available plastic bottle. Perimeter: 18.0 cm, shrinkage ratio: 16.3%) Check the tightness of the label, and check the 15.7 cm from the lower end. A sample in which the part was completely adhered was evaluated as good, and a sample in which the adhesion was insufficient was evaluated as defective.

(2) Specific gravity In accordance with JIS K-7112-1980, the specific gravity was measured by a density gradient tube method on a sample after label packaging in a PET bottle. (3) Separability The label film after label packaging in a PET bottle was cut into a square having a side of 10 cm, and cut into a square having a side of 1 cm to obtain a film piece. The obtained film piece was previously filled with 800 ml of distilled water at 25 ° C.
Placed in a liter beaker. A rotor having a length of 3 cm was put into a beaker, and the mixture was stirred with a magnetic stirrer so that the film pieces were dispersed throughout the beaker. After rotating the magnetic stirrer for 20 seconds, the rotation was stopped, and after the stop, the time required for all the film pieces to rise to near the water surface was measured. This operation is performed 10 times per sample.
The repetition was repeated twice, and the average of eight points excluding the maximum value and the minimum value was used as a measure of separability. The shorter the time when the film piece floats up to the vicinity of the water surface, the better the separability. It can be said that there is no problem if it is within 30 seconds.

(4) Melt flow rate (MFR) For propylene resin, JIS K-7210-1
According to 995, at 230 ° C. under a load of 2.16 kg, JIS K-72 for linear low density polyethylene resin
Based on 10-1995, 190 ° C, load 2.16kg
Was measured. (5) Differential scanning calorimeter (DSC) A sample (propylene α
-Olefin random copolymer) 5.0 mg
After holding at 00 ° C. for 5 minutes, the mixture was cooled to 40 ° C. at a temperature decreasing rate of 10 ° C./min, and further melted at a temperature increasing rate of 10 ° C./min to obtain a heat of fusion curve. T _p and T ₅₀ were determined from the obtained heat of fusion curve. (6) Softening point temperature Measured in accordance with JIS K-2207.

(7) Heat Shrinkage After aging the stretched film at 40 ° C. for 24 hours,
A square having a size of 0 cm × 10 cm is cut out so that one side thereof is parallel to the flow direction of the film, and this is placed in a water tank heated to a predetermined temperature (80 ° C., 90 ° C. or 100 ° C.).
Soaked for seconds. 25 ° C separately prepared immediately after 10 seconds
After immersion in a water tank for 20 seconds, the lengths of the film in the flow direction and in the orthogonal direction were measured. (8) Natural shrinkage After aging the stretched film at 40 ° C. for 24 hours, 1
The film was cut into a square of 0 cm × 10 cm so that one side thereof was parallel to the flow direction of the film, and this was placed in a 40 ° C. gear oven and left for 7 days. The length of each of the film left in the direction of flow and the direction perpendicular thereto was measured for 7 days. (9) Tensile elastic modulus (unit: MPa) The tensile elastic modulus was measured in the flow direction (MD) and the orthogonal direction (TD) of the film under the following conditions. The calculation method of the tensile modulus was based on JIS K-7127-1989. Sample length: 150mm, sample width: 15m
m, distance between chucks: 100 mm, crosshead speed:
1 mm / min (10) Feeling of waist At the time of packaging suitability evaluation, the feeling of waist when the created cylindrical label was grasped by hand was evaluated according to the following criteria. Kirin “Namacha” 5
The waist feeling is almost the same as that of the label attached to the 00 ml plastic bottle: ○ The waist feeling is slightly weak: △ The waist feeling is weak: × The waist feeling is evaluated as a substitute for productivity when the label is attached to the PET bottle. It is.

Example 1 80 parts by weight of PP powder and an alicyclic hydrocarbon resin (Alcon P manufactured by Arakawa Chemical Industries, Ltd.)
125, softening point 125 ° C) 0.05 parts by weight of calcium stearate, 0.1 parts by weight of phenolic antioxidant (Ciba Geigy, trade name Ir1010), 100 parts by weight of resin mixture consisting of 20 parts by weight, phosphorus 0.1 part by weight of an antioxidant (Ciba Geigy Co., trade name Ir168) and 0.1 part by weight of synthetic silica having an average particle size of 2.5 μm as an antiblocking agent were mixed with a Henschel mixer.
Granulation was performed with a 0 mm single screw extruder to obtain a resin composition. The obtained resin composition was used as a raw material and formed into a label film by the method described above. The minimum preheatable temperature at the time of film formation was 60 ° C. Table 1 shows the evaluation results of the obtained label films.

Example 2 Alcon P125 of Example 1
Was replaced with an alicyclic hydrocarbon resin (ESCOLETS E5320 manufactured by Tonex Corporation, softening point temperature 125 ° C.) to obtain a label film in the same manner as in Example 1. The minimum preheatable temperature at the time of film formation was 60 ° C. Table 1 shows the evaluation results of the obtained films.

Example 3 75 parts by weight of PP powder and an alicyclic hydrocarbon resin (Alcon P. manufactured by Arakawa Chemical Industries, Ltd.)
140, softening point temperature 140 ° C.) 100 parts by weight of a resin mixture consisting of 25 parts by weight, 0.05 parts by weight of calcium stearate, 0.1 part by weight of a phenolic antioxidant (Ciba Geigy, trade name Ir1010), phosphorus 0.1 parts by weight of a synthetic antioxidant (Ciba Geigy, trade name Ir168) and synthetic silica having an average particle size of 2.5 μm as an antiblocking agent were mixed with a Henschel mixer, and then granulated with a 50 mm single screw extruder. A resin composition was obtained. The obtained resin composition was used as a raw material and formed into a label film by the above-described method. The minimum preheatable temperature at the time of film formation was 60 ° C. Table 1 shows the evaluation results of the obtained films.

Comparative Example 1 Propylene-ethylene random copolymer (PP) was prepared using a normal Ziegler catalyst.
Was manufactured. The obtained propylene-ethylene random copolymer had the following physical properties. MFR:
2.30 g / 10 min, ethylene content: 3.60% by weight,
_{T p: 138.3 ℃, T 50} : 130 ℃. 80 parts by weight of PP powder and alicyclic hydrocarbon resin (Arakawa Chemical Industry Co., Ltd.)
100 parts by weight of a resin mixture consisting of 20 parts by weight of Alcon P140, softening point temperature 140 ° C.), 0.05 parts by weight of calcium stearate, 0.1 part by weight of a phenolic antioxidant (Ciba Geigy Co., trade name Ir1010) Then, 0.1 part by weight of a phosphorus-based antioxidant (Ciba Geigy Co., trade name Ir168) and synthetic silica having an average particle size of 2.5 μm as an antiblocking agent were mixed with a Henschel mixer.
Granulation was performed with a 0 mm single screw extruder to obtain a resin composition. The obtained resin composition was used as a raw material and formed into a label film by the method described above. The minimum preheatable temperature during film formation was 80 ° C. Table 1 shows the evaluation results of the obtained films. Although the separability was good, Examples 1 to 3 were used.
The packaging suitability was inferior to that of.

[Comparative Example 2] 60 parts by weight of PP powder and an alicyclic hydrocarbon resin (Alcon P, manufactured by Arakawa Chemical Industries, Ltd.)
140, 40 parts by weight of a resin mixture consisting of 40 parts by weight) 0.05 part by weight of calcium stearate, 0.1 part by weight of a phenolic antioxidant (Ciba Geigy, trade name Ir1010), 100 parts by weight of phosphorus 0.1 parts by weight of a synthetic antioxidant (Ciba Geigy, trade name Ir168) and synthetic silica having an average particle size of 2.5 μm as an antiblocking agent were mixed with a Henschel mixer, and then granulated with a 50 mm single screw extruder. A resin composition was obtained. The obtained resin composition was used as a raw material and formed into a label film by the method described above. The minimum preheating temperature that can be formed during film formation is 60 ° C
Met. Table 1 shows the evaluation results of the obtained films. The suitability for packaging was good, but the separability was worse than in Examples 1-3.

Example 4 75 parts by weight of PP powder
Resin mixture 100 consisting of 25 parts by weight of Escolets E5320 (softening point temperature 125 ° C.) manufactured by Tonex Corporation
After mixing 0.05 parts by weight of calcium stearate, 0.1 parts by weight of Ir1010, and 0.1 parts by weight of Ir168 with respect to parts by weight with a Henschel mixer, the mixture was granulated with a 50 mm single screw extruder and the base material layer (I ) Was obtained. Calcium stearate 0.0 to 100 parts by weight of PP powder
5 parts by weight, Ir1010 0.1 parts by weight, Ir168 0.1 parts by weight, weight average particle size 2.5 μm as an antiblocking agent
0.2 parts by weight of synthetic silica with a Henschel mixer and then granulated with a 50 mm single screw extruder to form a surface layer (II)
A resin composition for use was obtained. The obtained resin composition was formed into a label film by the method described above. The total thickness of the obtained film was 50 μm, the thickness of the substrate layer (I) was 44 μm, and the thickness of the surface layer (II) was 3 μm on both sides. The minimum preheating temperature at which the film could be formed was 60 ° C. Table 2 shows the evaluation results of the obtained films.

Example 5 (i) Production of Linear Low-Density Polyethylene 2.0 mmol of complex ethylenebis (4,5,6,7-tetrahydroindenyl) zirconium dichloride
Methylalumoxane (manufactured by Toyo Stoffer Co., Ltd.) was added at 1,000 times the molar amount of the above complex, and diluted to 10 liters with toluene to obtain a catalyst solution. A mixture of ethylene and 1-hexene was supplied to a 1.5-liter stirred autoclave continuous reactor so that the composition of 1-hexene was 83% by weight, and the pressure in the reactor was 1,100 kg. / C
m ² to maintain the reaction temperature was adjusted to reaction the feed rate of the catalyst solution to a 140 ° C.. MFR is 3.5 g / 1
0 min, density 0.898 g / cm ³ , Q value 2.1, 1
-An ethylene / 1-hexene copolymer (LLDPE-1) having a hexene content of 19% by weight was obtained. (ii) Production of Multilayer Film A resin composition for a base material layer (I) was obtained in the same manner as in Example 4. Next, 1 part by weight of silica (Superfine Super Floss manufactured by Celite Corporation), 0.1 part by weight of calcium stearate, 0.13 part by weight of Irganox 1076, 0.07 part by weight of Irgafos 168 per 100 parts by weight of LLDPE-1 powder Parts, tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphonite (PEPQ) was added in an amount of 0.07 parts by weight, mixed with a Henschel mixer, and then formed with a 50 mm single screw extruder. This was granulated to obtain a resin composition for the surface layer (II).
The obtained resin composition was formed into a label film by the method described above. The total thickness of the obtained film is 50 μm, the thickness of the substrate layer (I) is 44 μm, and the thickness of the surface layer (II) is
It was 3 μm on each side. The minimum preheating temperature at which the film could be formed was 60 ° C. Table 2 shows the evaluation results of the obtained films.

Example 6 75 parts by weight of PP powder
20 parts by weight of Escolets E5320 (softening point temperature 125 ° C) manufactured by Tonex Corporation, polybutene (Polybutene-1 manufactured by Shell Japan, trade name: PB8340) 5
0.05 part by weight of calcium stearate, 0.1 part by weight of Ir1010, and 0.1 part by weight of Ir168 were mixed with 100 parts by weight of a resin mixture consisting of parts by weight with a Henschel mixer, and then granulated with a 50 mm single screw extruder. Thus, a resin composition for the base material layer (I) was obtained. Otherwise, the same operation as in Example 4 was performed. The minimum preheating temperature that can be formed during film formation is 60 ° C
Met. Table 2 shows the evaluation results of the obtained films. In Table 2, the above polybutene is abbreviated as "PB-1".

Comparative Example 3 75 parts by weight of PP powder
Escolets E5320 manufactured by Tonex Corporation (softening point temperature: 125 ° C) 10 parts by weight of resin mixture consisting of 10 parts by weight of PB-1 and 15 parts by weight of PB-1 0.05 part by weight of calcium stearate, 0.1 part by weight of Ir1010, Ir16
8 After mixing 0.1 parts by weight with a Henschel mixer,
Granulation was performed with a 0 mm single screw extruder to obtain a resin composition for the base material layer (I). Otherwise, the same operation as in Example 4 was performed. The minimum preheatable temperature at the time of film formation was 60 ° C. Table 3 shows the evaluation results of the obtained films. Although there was no problem with the separability and packaging suitability, since the tensile elasticity was out of the range of the present invention, the feeling of waist was inferior.

Comparative Example 4 75 parts by weight of PP powder
10 parts by weight of Escolets E5320 (softening point temperature 125 ° C) manufactured by Tonex Corporation, ethylene / propylene random copolymer rubber (manufactured by JSR Corporation, trade name: E
P961SP) 0.05 parts by weight of calcium stearate with respect to 100 parts by weight of the resin mixture consisting of 15 parts by weight,
After mixing 0.1 part by weight of Ir1010 and 0.1 part by weight of Ir168 with a Henschel mixer, the mixture was granulated with a 50 mm single screw extruder to obtain a resin composition for a base material layer (I). Otherwise, the same operation as in Example 4 was performed. The minimum preheatable temperature at the time of film formation was 60 ° C. Table 3 shows the evaluation results of the obtained films. Since the relationship between the heat shrinkage and the specific gravity was out of the range of the present invention, there was no problem in the separability, but the packaging suitability was poor. Further, since the tensile modulus was out of the range of the present invention, the feeling of waist was inferior. In addition,
In Table 3, the ethylene / propylene random copolymer rubber was abbreviated as “EPR-1”.

Comparative Example 5 The same operation as in Example 4 was performed, except that the thickness of the base material layer (I) was changed to 20 μm and the thickness of the surface layer (II) was changed to 15 μm on both sides. Was. Table 3 shows the evaluation results of the obtained films.
The thickness configuration of the shrink label film was inappropriate, the tensile modulus was out of the range of the present invention, and the feeling of waist was reduced.

Comparative Example 6 A shrink label film was obtained in the same manner as in Example 4, except that the PP powder was changed to PP powder in the production of the resin composition for the base material layer (I) in Example 4. Table 3 shows the evaluation results of the obtained films. The properties of the propylene / ethylene random copolymer were inappropriate, the relationship between the heat shrinkage and the specific gravity was out of the range of the present invention, and there was no problem with the separability, but the packaging suitability was poor. There was no problem with waist feeling.

[0084]

[Table 1]

[0085]

[Table 2]

[0086]

[Table 3]

[0087]

The resin composition for heat-shrinkable polypropylene shrink label of the present invention and the film using the same have a lower specific gravity and a significantly improved heat shrinkage ratio as compared with other conventional films. Since the low-temperature shrinkage and the tensile elasticity are also improved, it is suitable for use as a shrink label.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) C08J 5/18 CES C08J 5/18 CES G09F 3/04 G09F 3/04 C // B29K 23:00 B29K 23 : 00 105: 02 105: 02 B29L 7:00 B29L 7:00 C08L 23:10 C08L 23:10 F term (reference) 3E067 AA22 AB99 AC01 BA21A BA40A BB15A BB16A BB18A BB22A BB25A BC03A CA01 FA01 FB01 FC02 3E086 AB03 BA03 AD30 BA15 BA33 BB67 CA40 4F071 AA14X AA15X AA20 AA20X AA76 AA76X AA82 AA84 AA85 AA88 AC09 AC11 AC15 AE05 AE11 AF20Y AF43Y AF61Y AH04 AH06 BA01 BB06 BB07 BC01 BC12 4F100 AK07A AK07J AK09B AK63B AK64B AK66B AL03B BA01 BA02 JA03A JA06A JA11A JA13A JK07A 4F210 AA11 AA11H AE01 AG01 AG03 RA03 RC02 RG02 RG04 RG43

Claims (9)

[Claims] 1. A film comprising a polypropylene-based resin composition, wherein the shrinkage in the main shrinkage direction satisfies the following expression, and the specific gravity is 0.94 or less, the shrinkage ratio in the main shrinkage direction at 40 ° C. for 7 days. Is less than 3%. 3. A heat-shrinkable polypropylene shrink label film. S ₈₀ > 251d-215 S ₉₀ > 531d-462 S ₁₀₀ > 627d-541 (however, S ₈₀ , S ₉₀ , and S ₁₀₀ each have a film thickness of 80
The shrinkage (%) in the main shrinkage direction when water bathed in water at 90 ° C., 90 ° C., and 100 ° C. for 10 seconds, and d represents the specific gravity of the film. ) 2. A film comprising a polypropylene-based resin composition, wherein the shrinkage in the main shrinkage direction satisfies the formula (1), and the specific gravity is 0.94 or less, the shrinkage ratio in the main shrinkage direction at 40 ° C. for 7 days. A heat-shrinkable polypropylene shrink label film, wherein the tensile modulus in the lower of either the machine direction (MD) or the cross direction (TD) is 1000 MPa or more. S ₈₀ > 251d-215 S ₉₀ > 531d-462 S ₁₀₀ > 627d-541 (however, S ₈₀ , S ₉₀ , and S ₁₀₀ each have a film thickness of 80
The shrinkage (%) in the main shrinkage direction when water bathed in water at 90 ° C., 90 ° C., and 100 ° C. for 10 seconds, and d represents the specific gravity of the film. ) 3. The heat-shrinkable polypropylene shrink label according to claim 1, wherein the polypropylene resin composition is a resin composition mainly composed of a crystalline propylene / α-olefin random copolymer. For film. 4. The heat-shrinkable polypropylene shrink label film according to claim 3, wherein the crystalline propylene / α-olefin random copolymer satisfies characteristics (1) to (4). Melt flow rate (MFR) 0.5 to 10 g / 1
0 min using a differential scanning calorimeter (DSC) in the obtained melting peak temperature (T _{P) is, 100~140 ℃ T 50 ≦ 125 ℃} ( However, T ₅₀ is when the total heat of fusion as determined by DSC and [Delta] H _m The heat of fusion calculated from the low temperature side is 50% of ΔH _m
Represents the temperature (° C.) at which ) 5. The heat shrinkable polypropylene shrink label film according to claim 3, wherein the crystalline propylene / α-olefin random copolymer is a propylene / ethylene random copolymer. 6. The heat-shrinkable polypropylene shrink label film according to claim 3, wherein the crystalline propylene / α-olefin random copolymer is polymerized by a metallocene catalyst. 7. A polypropylene-based resin composition comprising a crystalline propylene / α-olefin random copolymer 50 to 10.
The heat-shrinkable polypropylene shrink label film according to any one of claims 1 to 6, comprising 0% by weight and 0 to 50% by weight of an alicyclic hydrocarbon resin having a softening point of 110 ° C or higher. 8. The heat-shrinkable polyolefin shrink label film is a multilayer film having two or more layers.
The heat-shrinkable polyolefin-based shrink label film according to any one of claims 7 to 7. 9. A base layer (I) comprising the polyolefin resin composition according to claim 7 and a surface layer (II) comprising a resin composition comprising one or more thermoplastic resins selected from the following group [A]: The film for a heat-shrinkable polyolefin-based shrink label according to any one of claims 1 to 8, wherein the thickness of the base material layer (I) is 50 to 99% of the total film thickness. -Ethylene random copolymer, linear low density polyethylene, polybutene-1, propylene-butene-1 random copolymer, ethylene-propylene random copolymer rubber, ethylene-butene-1 random copolymer, amorphous Olefin polymer