JP3296126B2 - Polypropylene film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene film having an excellent balance of impact resistance, flexibility and heat sealability, and having good moldability.
The present invention relates to a polypropylene film comprising polypropylene and a specific hydrogenated diene copolymer and having characteristics suitable for various uses.

[0002]

2. Description of the Related Art A polypropylene film is suitably used for various applications because it is inexpensive and has excellent heat resistance and mechanical properties. However, impact resistance, especially at low temperatures, is not sufficient, and the balance between impact resistance, flexibility and heat sealability is limited, and molding workability is not sufficient. Is receiving. The present invention has been developed on the background of such technical problems, and has a good low-temperature impact resistance, an excellent balance of impact resistance, flexibility and heat sealability, and excellent moldability. And completed the present invention.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical problems, and has an excellent low-temperature impact resistance, a good balance of impact resistance, flexibility and heat sealability. Another object of the present invention is to provide a novel polypropylene film having good moldability.

[0004]

SUMMARY OF THE INVENTION The present invention relates to (a) a polybutadiene polymer block (A) having a polypropylene content of 1 to 98% by weight and (b) a 1,2-vinyl bond content of 25% or less; A conjugated diene moiety having a 1,2- and 3,4-bond content of 50%
A block copolymer comprising the above polymer block (B), wherein (A)-(B) a block copolymer,
(A)-(B)-(A) a block copolymer comprising at least one of a block copolymer or a block copolymer in which the block copolymer unit is extended or branched via a coupling agent residue. The polymer was hydrogenated, the double bond of the conjugated diene portion was saturated by 70% or more, and the number average molecular weight was 4 to 7
1 to 98% by weight of a hydrogenated diene copolymer which is 100,000, and (C) 1 to 98% by weight of an ethylene-1-butene copolymer
[Provided that (a) + (b) + (c) = 100% by weight] is provided.

[0005] First, the polypropylene (a) used in the present invention is a crystalline polypropylene, which contains a propylene homopolymer or an α-olefin such as ethylene, 1-butene or 1-hexene in an amount of 15 mol% or less, preferably 15 mol% or less. Is a polymer containing 0.5 to 10 mol%. The copolymer may be a random copolymer, a blend with a homopolymer obtained by multi-stage polymerization, or an ordinary blend. The density of polypropylene is 0.885
0.915 g / cm ³ and a melt flow rate (MFR) of 0.1 to 50 g / 10 min, and preferably 0.1 to 50 g / 10 min.
2 to 40 g / 10 min. As a method for obtaining these polypropylenes, there are a method using a Ziegler-Natta catalyst, a method using a Kaminsky catalyst, and the like. As the component (A) of the present invention, polypropylene using any polymerization catalyst is also suitable. Used for However, the stereoregularity of the propylene unit is preferably isotactic or syndiotactic as the component (A) of the present invention.

The (ii) hydrogenated diene copolymer used in the present invention is basically composed of a conjugated diene. Examples of the conjugated diene used here include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, and 1,3-hexadiene. , 4,5-diethyl-
Examples thereof include 1,3-octadiene, 3-butyl-1,3-octadiene, and chloroprene. However, in order to obtain a hydrogenated diene-based copolymer that is industrially usable and has excellent physical properties, Butadiene, isoprene and 1,3-pentadiene are preferred, and 1,3-butadiene and isoprene are particularly preferred. The hydrogenated diene copolymer (b) of the present invention comprises a polybutadiene polymer block (A) having a vinyl bond content of 25% or less and a polymer block mainly composed of a conjugated diene. (A)-(B) and / or (A)-(B)-(A) comprising a polymer block (B) having a 1,2-bond content of 50% or more.
It consists of a block copolymer.

The block (A) in the component (b) of the present invention
Is converted into a crystalline polymer block having a structure similar to that of ordinary low-density polyethylene by hydrogenation. Preferred polybutadiene 1 before hydrogenation in block (A)
The 2-vinyl bond content is usually 25% or less, preferably 20% or less, and more preferably 15% or less. When the 1,2-vinyl bond content of the polybutadiene before hydrogenation in the block (A) exceeds 25%,
The drop in crystal melting point after hydrogenation is remarkable, and the impact resistance is poor.

The block (B) in the component (b) includes:
A conjugated diene homopolymer or a vinyl aromatic compound-conjugated diene copolymer is preferred. That is, as a structure after hydrogenation, for example, when the conjugated diene is butadiene,
A rubber-like ethylene-1-butene copolymer block or a polymer block having a structure similar to that of a vinyl aromatic compound-ethylene-1-butene copolymer is a block (B).
Is preferable.

The vinyl aromatic compound used in the block (B) includes styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene, divinylbenzene, N, N-dimethyl-p-aminoethyl Styrene, N, N-diethyl-p-aminoethylstyrene,
Vinyl pyridine and the like can be mentioned, among which styrene and α-methyl styrene are preferable, and styrene is particularly preferable. The preferred amount of the vinyl aromatic compound used in the block (B) is 3% of the monomer constituting the block (B).
The content is 5% by weight or less, more preferably 30% by weight or less, and most preferably 25% by weight or less. When it exceeds 35% by weight, the glass transition temperature of the block (B) increases, and the impact resistance and flexibility are poor. Instead, the transparency also decreases.
The preferred 1,2-bond content of the conjugated diene portion of the block (B) before hydrogenation is 50 to 95%, more preferably 60 to 95%, and is less than 50% or 95%.
When the conjugated diene is more than 3, for example, when the conjugated diene is butadiene, the conjugated diene shows a crystal structure derived from a polyethylene chain and a polybutene-1 chain, respectively, becomes a resinous property, and has poor flexibility.

In the component (b) of the present invention, the block (A) is preferably 5 to 90% by weight, more preferably 1 to 90% by weight.
0 to 80% by weight, and the block (B) is preferably 10 to 9%.
It is 5% by weight, more preferably 20 to 90% by weight. When the content of the block (A) is less than 5% by weight and / or the content of the block (B) exceeds 95% by weight, the crystalline polymer block is insufficient, and the mechanical strength is poor. And the block (B) is less than 10% by weight and / or the block (A)
Exceeds 90% by weight, the flexibility is poor.

The hydrogenated diene-based copolymer used as the component (b) in the present invention can have a polymer molecular chain extended or branched as represented by the following general formula by adding a coupling agent. Block copolymer may be used. [(A)-(B)] _n -Z or [(A)-(B)-(A)] _n -Z [wherein (A) and (B) are the same as above. n represents an integer of 2 to 4, and Z represents a coupling agent residue. As the coupling agent at this time, for example, diethyl adipate, divinylbenzene, methyldichlorosilane, tetrachlorosilane, butyltrichlorosilane, tetrachlorotin, butyltrichlorotin, dimethylchlorosilane, tetrachlorogermanium, 1,2-dibromoethane , 1,4-chloromethylbenzene, bis (trichlorosilyl) ethane, epoxidized linseed oil, tolylene diisocyanate, 1,2,4-benzene triisocyanate, and the like. Further, the hydrogenated diene polymer used as the component (b) in the present invention may be modified with a functional group,
Using an unsaturated compound having at least one functional group selected from an acid anhydride group, a carboxyl group, a hydroxyl group, an amino group, an isocyanate group and an epoxy group,
It can be modified with a kneader, a mixer, an extruder or the like.

The hydrogenated diene copolymer (b) used in the present invention contains at least 70%, preferably at least 80%, of the double bonds of the conjugated diene moiety in the blocks (A) and (B). More preferably, 90% or more needs to be hydrogenated and saturated, and if it is less than 70%, the transparency, heat sealability, and moldability of the obtained film are insufficient, which is not preferable.

The (b) hydrogenated diene copolymer of the present invention has a preferred number average molecular weight of 40,000 to 700,000, more preferably 1 to 700,000.
If it is from 0,000 to 600,000, and if it is less than 40,000, the impact resistance of the obtained film is inferior, while if it exceeds 700,000, the molding processability is inferior. Also, a blend of two or more hydrogenated diene polymers is suitably used as the component (b) of the present invention. The (ii) hydrogenated diene copolymer used in the present invention can be obtained by a method disclosed in, for example, JP-A-3-74409 and JP-A-3-128957.

[0014]

[0015]

[0016]

[0017]

The component (c) used in the present invention is ethyl
1-butene copolymer. Addition of this (c) component
Excellent low-temperature impact resistance, flexibility, impact resistance and heat resistance
It is possible to obtain a film with good balance of sealability
It works . In the film of the present invention, the component (a) comprises 1
To 98% by weight, preferably 10 to 98% by weight, more preferably 30 to 98% by weight, and still more preferably 40 to 98% by weight.
% By weight, particularly preferably 50 to 98% by weight, the component (b) 1 to 98% by weight, preferably 1 to 90% by weight, more preferably 1 to 70% by weight, further preferably 1 to 60% by weight, particularly Preferably, the content is 1 to 50% by weight, and the component (c) is 1
To 98% by weight, preferably 1 to 90% by weight, more preferably 1 to 70% by weight, still more preferably 1 to 60% by weight, particularly preferably 1 to 50% by weight [where (A) +
(B) + (c) = 100% by weight]. When the amount of the component (a) is less than 1% by weight and / or when the amount of the component (B) or the component (C) exceeds 98% by weight, moldability deteriorates. When the component (b) or the component (c) is less than 1% by weight and / or the component (a) exceeds 98% by weight, transparency and impact resistance are poor.

Additives used for ordinary thermoplastic materials can be added to the polypropylene-based flexible film of the present invention as needed. For example, plasticizers or reinforcing agents such as phthalic acid esters, rubber fillers such as paraffinic oil, fillers such as silica, talc and calcium carbonate, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, antibacterial agents, Flame retardants, foaming agents, coloring agents, pigments, carbon fibers, metal fibers, glass beads, crosslinking agents, crosslinking aids, etc.
Alternatively, a mixture thereof can be added.

As the components constituting the film of the present invention, thermoplastic materials and rubber-like polymers other than the above-mentioned components (a) to (c), such as low-density polyethylene, high-density polyethylene, and ethylene-propylene copolymer rubber , Ethylene-propylene-non-conjugated diene copolymer, ethylene-1
-Butene copolymer, ethylene-1-hexene copolymer,
Ethylene-α- such as ethylene-1-octene copolymer
Olefin copolymers, polybutene, propylene-1
-Butene copolymer, polymethylpentenes such as poly-4-methyl-1-pentene, ethylene-cyclic olefin copolymers such as ethylene-norbornene copolymer, hydrogenated terpene resin, petroleum resin, polyisobutylene, Poly (alkyl acrylate) such as polystyrene, poly (methyl acrylate) and poly (ethyl acrylate); poly (methyl methacrylate) such as poly (methyl methacrylate) and poly (ethyl methacrylate); polybutadiene polymer and / or hydrogenated product thereof; styrene-butadiene Copolymer,
Styrene-isoprene copolymer, butadiene-isoprene copolymer and / or hydrogenated product thereof, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer A polymer, an ethylene-methyl acrylate copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-ethyl acrylate copolymer, an acrylic rubber, an ethylene ionomer, and the like can be blended. A thermosetting polymer, for example, an epoxy resin, a phenol resin, a silicone resin, or the like can be blended as long as the properties are not impaired.

The film of the present invention can be easily formed by a conventionally known method such as T-die molding, inflation molding, and calendar molding. The film of the present invention also includes
It is also possible to carry out a stretching treatment. As a method of performing the stretching treatment, a known uniaxial stretching method such as roll stretching, roll rolling, and tenter horizontal uniaxial stretching, and a known biaxial stretching method such as tenter biaxial stretching or tubular biaxial stretching can be employed. . The stretching temperature in the stretching treatment is preferably from room temperature to the melting point of polypropylene, and the stretching ratio is preferably 2 to 10 times. However, the MD and TD stretching ratios do not necessarily need to be balanced, and can be arbitrarily selected according to each application. Incidentally, depending on the purpose of the film of the present invention, by laminating a film of the present invention and a film of a polyolefin-based resin or ethylene-α-olefin-based resin or a mixture thereof, a film having more excellent properties. It is possible to get. It is also possible to laminate with such materials as an ethylene-vinyl acetate copolymer, an ethylene-unsaturated carboxylic acid copolymer or a derivative thereof copolymer, and an ethylene-vinyl alcohol copolymer. By laminating with the film of the invention, it is possible to obtain films suitable for various purposes. In addition, examples of a method of obtaining these laminates include a co-extrusion T-die molding method and a co-extrusion inflation molding method, but are not particularly limited.

Since the film of the present invention is excellent in transparency, flexibility and impact resistance, it can be used for packaging various clothes such as shirts and stockings, packaging for beddings such as futons and pillows, etc.
Used for various food packaging, daily goods packaging, industrial material packaging, lamination of various rubber products, resin products, leather products, etc., elastic tape used for disposable diapers, industrial goods such as dicing film, protection of building materials and steel sheets. Protective films, trays for fresh fish, sheets for fruits and vegetables, frozen dessert food containers, etc., household appliances such as TVs, stereos, vacuum cleaners, etc., automotive interior and exterior parts such as bumper parts, body panels, side seals, road paving materials ,
It can be used for a wide range of applications such as waterproof / waterproof sheets, civil engineering packing, other daily necessities, leisure goods, toys, industrial goods, furniture supplies, writing utensils, medical utensils, etc.

[0023]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention. In the examples, parts and% are by weight unless otherwise specified. The evaluation of various physical properties in the examples was performed by the following methods. The vinyl bond content of the conjugated diene was calculated by the Hampton method using infrared analysis. Using hydrogenated ethylene tetrachloride as a solvent, 100 MHz, ¹ H-N
It was calculated from the MR spectrum. The number-average molecular weight of the hydrogenated diene copolymer was determined in terms of polystyrene by gel permeation chromatography (GPC) at 135 ° C. using trichlorobenzene as a solvent. Formability The workability during film formation was evaluated as follows. ：: Good workability at the time of molding ×: Poor workability at the time of molding such as poor extrusion and poor take-off Impact resistance Measured according to JIS Z1707. did. Flexibility The Young's modulus was measured in accordance with JIS K7127 and used as an index of flexibility. Heat sealability The peel strength of the heat seal portion was measured in accordance with JIS Z1707 and used as an index of the heat sealability. Transparency All hazes were measured in accordance with JIS K6782 and used as an index of transparency.

Reference Examples Various components used in the formulations shown in Examples and Comparative Examples are as follows. Polypropylene PP-1 [FM821 manufactured by Chisso Petrochemical Co., Ltd.] Density 0.9 g / cm ³ , MFR 7 g / 10 min PP-2 [EFL-200 manufactured by Mitsui Toatsu Chemicals, Inc.] Density 0.9 g / cm ³ , MFR 6 g / 10 min PP- 3 [FM831-B manufactured by Chisso Petrochemical Co., Ltd.] Density 0.9 g / cm ³ , MFR 6.5 g / 10 min Hydrogenated diene copolymer Microstructure shown in Table 1, A hydrogenated diene copolymer having a number average molecular weight and a degree of hydrogenation (Q-1 to Q- 6 ).

[0025]

[Table 1]

Olefinic polymer mainly composed of ethylene R-1 [1-butene content: 20%, MFR: 6.6 g /
Ethylene-1-butene copolymer for 10 minutes] R-2 [1-butene content is 20%, MFR is 0.9 g /
Ethylene-1-butene copolymer for 10 minutes] R-3 [1-butene content 21%, MFR 6.5 g /
Ethylene-1-butene copolymer for 10 minutes] R-4 [Propylene content: 22%, MFR: 3.5 g /
Ethylene-propylene copolymer for 10 minutes]

Examples 1 to 4 and Comparative Examples 1 to 7 The compositions having the compositions shown in Tables 2 to 3 were prepared by using a composition having a diameter of 50 mm and L / D
6, using an extruder, kneading at 180-240 ° C., supplying the mixture to a T-die, die temperature 210-230 ° C., thickness 50 μm
Was produced. Tables 2 and 3 also show the molding processability at the time of film production and the evaluation results of the physical properties of the obtained film.

[0028]

[Table 2]

[0029]

[Table 3]

As is evident from the results of Examples 1 to 4 , the film of the present invention has excellent low-temperature impact resistance, good flexibility and heat sealability, and further has good moldability and transparency.
It can be seen that is also excellent in sex. On the other hand, Comparative Example 1 is an example using only the component (A), but is inferior in transparency and impact resistance, and has flexibility, heat sealability, and moldability as compared with the film of the present invention. Is also insufficient. Comparative Examples 2 to 4 are examples in which the structure of the hydrogenated diene copolymer is out of the range of the present invention and does not include the component (c). Among these, Comparative Examples 2 and 4
Shows that both transparency and impact resistance are inferior, and that Comparative Example 2 is inferior in flexibility and Comparative Example 4 is inferior in moldability. Comparative Example 3 has good transparency and flexibility, but has insufficient heat sealability, and further has poor impact resistance. In Comparative Examples 5 to 7, the component (b) was not used, and only the component (a) and the component (c) were used. It can be seen that in all cases, the low-temperature impact resistance and the molding processability are inferior, and the flexibility and the heat sealability are insufficient.

[0031]

The present invention provides a film comprising polypropylene, a specific hydrogenated diene copolymer, and an ethylene-1-butene copolymer, and has a lower temperature than conventional films. It is possible to provide a film having excellent properties such as impact resistance and flexibility. The film of the present invention can meet a wide variety of demands from the industry due to the above excellent properties. Specifically, packaging of various clothing such as shirts and stockings, packaging of bedding such as futons and pillows, packaging of various foods, daily miscellaneous goods packaging, industrial material packaging, various rubber products, resin products, leather products, etc. Film applications such as elastic tape used for laminating and disposable diapers, dancing films, etc., sheet applications such as meat and fresh fish trays, fruit and vegetable packs, frozen dessert food containers, home appliances, automotive interior / exterior parts, waterproof sheets, leisure goods, toys It can be used for a wide range of applications such as industrial supplies, furniture supplies, writing utensils, medical utensils and the like.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Fujimaki required 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (72) Inventor Toru Shibata 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (72) Inventor Yoichi Kamoshida 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-3-128957 (JP, A) JP-A-3- 74409 (JP, A) JP-A-6-306220 (JP, A) JP-A-7-252390 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 23/00-23 / 36 C08L 53/00-53/02 C08J 5/18

Claims (1)

(57) [Claims] 1. A polybutadiene polymer block (A) having (a) 1 to 98% by weight of polypropylene and (b) a 1,2-vinyl bond content of 25% or less, and a polymer mainly composed of a conjugated diene. A block copolymer comprising a conjugated diene moiety having a 1,2- and 3,4-bond content of 50% or more, and a polymer block (B), wherein (A)-
(B) a block copolymer, (A)-(B)-(A) a block copolymer, or a block copolymer in which the block copolymer unit is extended or branched via a coupling agent residue; A hydrogenated diene copolymer having a number average molecular weight of 40,000 to 700,000 wherein the double bond of the conjugated diene portion is saturated by 70% or more. (C) 1 to 98% by weight of an ethylene-1-butene copolymer
[However, (a) + (b) + (c) = 100% by weight].