JPS5973948A - Laminated inflation film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated blown film that is characterized by good transparency, gloss, and transparency, excellent impact strength, and strong stiffness.

Conventional melt index 01,! i' / 1omI
Inflation films made from high-molecular-weight polyethylene, such as those with a molecular weight of less than However, since it is opaque, there is a problem that its use is restricted in parts such as vegetable bags, which require transparency.

As a result of various studies aimed at improving the shortcomings of conventional techniques, the present inventors discovered a laminated blown film that has good transparency, gloss, and transparency, has excellent impact strength, and is flexible. It's arrived.

The gist of the present invention is that the middle layer has a tart index of 0.1.9.
/10 degrees or less and a density [1,940 g/cff1 or more high density ethylene polymer or ethylene-α olefin copolymer C or less referred to as resin-containing] 40 to 95 weight 5 J%,
Melt index 5g/10mm or less Te density Fff-0
930/cnt or less low bud degree ethylene-α olefin copolymer (hereinafter referred to as resin B) mixture of 5 to 60% of old amount is fine t13! l? , inner and outer layers are more transparent and glossy than resin A, 'JyJiIi! Ethylene polymer with good properties,
Copolymer or mixture thereof (hereinafter referred to as resin C)
This is a laminated blown film characterized by a three-layer sandwich structure consisting of:

In the present invention, the resin A is typically an ethylene polymer or a mono-α-olefin copolymer.
Examples include 1,4-methyl-1-pentene and octene-1. Resin A has a melt index of 0-1 g/
1 rJmm or less, preferably 0.07 g/10 or less, and if it exceeds 9/I D mm, sufficient impact collapse and elasticity cannot be obtained, and considering moldability, the melt index is 0. 0.02g/10mvr or more is preferable, and if it is less than 0.02g/10mvr, uneven thickness or flow tends to occur.On the other hand, the high road melt index/melt index is preferably 100 or more and 250 or less.

If the high road melt index is less than 100, the fluidity will be poor and uneven thickness or flow will occur.
If it exceeds 0, it is difficult to improve transparency.

If the density is less than o and q 409/c1, the strength of the waist will be insufficient. The melt index is JIS K6.
760 with a load of 2.16 kg, the High Road Melt Index means a load of 21.6 kg in the same standard.
This means the case of g.

Further, resin B is an ethylene-α-olefin copolymer or a mixture thereof, and the α-olefin has carbon atoms of 6 to 12, such as propylene, butene-1, hexene-1,4-methyl-
Examples include 1-pentene and octene-1. Resin B has a melt index of 5g/10m* or less, preferably 2g/
Under l a hearing, melt index 5g/109
Exceeding this will reduce impact strength and lower back strength. Density is 09
30.9/afl or less, preferably 0.925g/cn
It is less than or equal to t, o, 93o,! If it exceeds 7/cnt
R Clarity, transparency! 1′! Transparency decreases to r. On the other hand, if it is less than c1.915,9/Cff1, the sacrum of the lower back will decrease, so it is preferably 0.915~"925 El /c
A good film is obtained with I'lt.

Further, it is preferable that the resin B is a straight-chain polyethylene having carbon atoms of 10 or less and a short chain branching degree (alkyl group/1000C) of 15 or more, since transparency, gloss, and transparency are excellent, and the branching degree is less than 15. The transparency is poor.

The mixing ratio of resin A and resin B is based on resin A + B.
is 40 to 95% by weight, and if it is less than 40% by weight, the strength of the waist will decrease, and if it exceeds 95% by weight, the transparency, especially the visibility will be decreased.

Resin C is an ethylene polymer, copolymer, or a mixture thereof, which has the same thickness as resin A and has good transparency, gloss, and see-through, and the representative color copolymer is an ethylene-α-olefin copolymer. α-olefin has 6 to 6 carbon atoms.
12 such as propylene, butene-1, hexene-1,
Examples include 4-methyl-1-pentene and octene-1.

Further, the resin C is an ethylene-α-olefin copolymer, and preferably has a melt index of 0.1 to 2 g/10 mm, and AO-'I 9 / 10 mm or more can suppress uneven thickness, flow, and unevenness of 2 g/10 mm. If it is less than lomm, impact strength and stiffness will be improved, and the high road melt index/melt index is preferably 100 or less, thereby improving transparency and the density is 0.935.
A score of 9/C♂ or higher is preferable, which improves the strength of the lower back.

The laminated blown film of the present invention exhibits high impact strength and stiffness by being blown, and can be molded using a plurality of extrusion blocks and a co-extrusion inflation die. Furthermore, it has excellent transparency, gloss, and visibility. The reason why the transparency (haze) and gloss (gloss) are good is that resin C exists in the inner and outer layers, and transparency (clarity) depends on resin B, which reduces internal diffuse reflection in the intermediate layer. It is thought that this process can be made quickly.

1. The resin CG of the inner and outer layers does not necessarily have to be the same resin. The laminated blown film of the present invention thus obtained has a thickness of 10 to 50μ.
250 kgcrrv'mm or more, haze of 15% or less for transparency, gloss of 60% or more for gloss, and clarity of 20% or more for transparency.

The present invention will be further elaborated and explained in detail by giving Examples and Comparative Examples below. In Table 1, ↓ means the same as above, - means not present, and the characteristics of each side were measured under the following conditions. Further, in Table 1, HDPE means high-density polyethylene, and L-LDPE means linear low-density polyethylene.

1) Density: JIS K6760 4) Gloss: ASTM D523. 6) Film impact: 1 inch hemisphere, temperature 23°C 7) Film Young's modulus: AST, M D8B2 Examples 1 to 9
, Comparative Examples 1 to 6 Each resin shown in Table 1 was used as the raw material resin for the intermediate layer and the inner and outer layers. It was melt extruded and air cooled to a blow-up ratio of 4. O, Frist line: 900 Fight 1, Pick up speed: 25 m
The thickness of each layer is 0.02 mIn5 for the middle layer under the condition of /7'a.
Product y or thickness of inner and outer layers 0.005m* is 0.06mm
A single-layer blown film was formed and the physical properties of the film were measured.

Physical property measurement results for each side of Examples q) It can be seen that he has strong hips.

On the other hand, if resin B is not added to the intermediate layer as in Comparative Examples 1 and 6, the transparency (clarity) deteriorates and the ratio i1+i
>In the middle layer made only of resin C as in Example 2, the Young's modulus is rJ
! i<, and the iJt layer made of only resin A, as in Comparative Example B, has poor gloss. Further, even if resins ASB and C are used as in Comparative Examples 4 and 5, the impact will be reduced if the melt index of resin A or B is larger than a predetermined value.

Claims (1)

[Claims] 1) The intermediate layer has a melt index of 0.1.51/1om.
40 to 95% by weight of high-density ethylene polymer or ethylene copolymer with a density of 0.9409/a♂ or higher at x or less
and melt index 5g/10mff1 or less is dense 1
1f Mixture with 5 to 60% ethylene-α olefin copolymer with low density of 0.930 fJ / cJ or less, inner and outer layers are upper surfaces, 1 melt index 0=, F/1omH
An ethylene polymer, copolymer, or mixture thereof that has better transparency, gloss, and visibility than a high-density ethylene polymer or ethylene copolymer with a density of 0.940 fJ/c or rR at a temperature of 8° or less. A laminated blown film characterized by having a three-layer sandwich structure. 2) Melt index in middle layer 5g/10mr
Short chain branching of a low-density ethylene-α olefin copolymer with a density o93 og/cJ or less and a density o93 og/cJ or less
2. The laminated blown film according to claim 1, wherein the number of alkyl groups in C is 15 or more. 3) High-density ethylene polymer or ethylene-α olefin copolymer with a melt index of 01 to 2 g/mm, a high load melt index/melt index value of 100 or less, and a density of 0.935 fJ/cnY or more for the inner and outer layers. A laminated blown film according to item 1 of the scope of the patent δh, characterized in that the laminated blown film uses the following.