Mitsui Chemicals, Inc.

Ikuo Akai

Koji Matsunaga

Tomohiro Abe

Masayoshi Yamaguchi

Shinya Tanaka

Koya Yoshimoto

Makoto Egawa

Hiroshi Hoya

Takayuki Kuroki

Yoji Hayakawa

An object of the invention is to provide compositions which have low-temperature heat sealing properties, are free from stickiness, may achieve a heat seal strength controlled within a certain definite range when heat sealing takes place at low temperatures, have small changes in heat seal strength with time, and are such that in the packaging applications, the strength required to open the packages may be easily controlled within a certain definite range, and high-performance packages may be designed. The invention resides in a 1-butene.&#x3b1;-olefin copolymer composition including 99 to 1 parts by mass of at least one olefin polymer (X) selected from propylene polymers (X-1) and ethylene polymers (X-2), and 1 to 99 parts by mass of a 1-butene.&#x3b1;-olefin copolymer (Y) containing 0.1 to 30 mol % of one or more &#x3b1;-olefins selected from &#x3b1;-olefins and having a molecular weight distribution (Mw/Mn) of 1.0 to 3.5 [wherein the total of (X) and (Y) in the composition is 100 parts by mass].

1-butane-&#x3b1;-olefin copolymer composition

The polyolefin composite film is excellent in low-temperature heat sealability, heat-sealing strength and transparency, and at least has surface layer [i]//intermediate layer [iii]//core layer[i], wherein the surface layer[i]includes a propylene resin composition including 0-50 wt % of a specific propylene&#x3b1;-olefin random copolymer (A) and/or a specific 1-butene&#x3b1;-olefin copolymer (E), and 50-100 wt % of a propylene polymer (B) having a melting point of 120-170&#xb0; C. ((A), (E) and (B) in the surface layer totals 100 wt %); the core layer [ii]includes a propylene resin composition including 70-100 wt % of a crystalline polypropylene (C) having a melting point of 150-170&#xb0; C., and 0-30 wt % of the copolymer (A) ((C) and (A) in the core layer totals 100 wt %); and the intermediate layer[iii]includes a propylene resin composition including 50-95 wt % of the crystalline polypropylene (C) and 50-5 % of the polymer (B), the copolymer (A), andor the copolymer (E) ((C), (B), (A) and (E) in the intermediate layer totals 100 wt %).

Polyolefin composite film

1-butene &#x3b1;-olefin copolymer composition

Propylene-based polymers (A) are provided which, when used as pressure-sensitive adhesives to various adherends, show a desired initial adhesion and will not contaminate the adherends and which have excellent pellet handling properties. Pellets of the invention contain the propylene-based polymers (A). Pressure-sensitive adhesives of the invention contain the propylene-based polymers (A). The propylene-based polymer (A) includes 65 to 80 mol % of a structural unit derived from propylene, 5 to 10 mol % of a structural unit derived from ethylene and 15 to 25 mol % of a structural unit derived from a C4-20 &#x3b1;-olefin (wherein these percentages are calculated based on 100 mol % of the total of the structural unit derived from propylene, the structural unit derived from ethylene and the structural unit derived from a C4-20 &#x3b1;-olefin) and has a heat of crystal fusion of 5 to 45 (J/g) as measured by DSC. Compositions of the invention contain the propylene-based polymers (A).

Propylene-based polymer, propylene-based polymer composition, pellet and pressure-sensitive adhesive

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Narashino, Japan

Ikuo Akai