JPS5817135A - Modification of low-density polyethylene resin - Google Patents

Abstract

PURPOSE:To improve transparency, surface gloss, molding speed, etc. of moldings without causing faults such as bleedout, etc., by blending a specified sorbitol derivative as a nucleating agent with a low-density polyethylene resin. CONSTITUTION:0.03-3wt% compd. of the formula (wherein X is halogen, 1- 3C lower alkyl; n is 1-3 when X is halogen and n is 2-5 when X is lower alkyl; p is 0-1) as a nucleating agent is blended with (linear) low-density polyethylene to modify the same. The compd. of the formula can be obtd. by condensing sorbitol or xylitol with a substd. benzaldehyde. Examples of the compd. of the formula are di(2,4-dimethylbenzylidene) sorbitol and di(p-chlorobenzylidene)sorbitol.

Description

Detailed Description of the Invention: A nucleating agent is blended with the IjlFl low-density polyethylene resin of the present invention, specifically, a bell-shaped low-density polyethylene resin or a low-texture polyethylene resin, to obtain a second grade resin molded product with transparency, gloss on both surfaces, and molding. Concerning how to improve speed etc.
・It is known that addition of a nucleating agent such as dipendylidan solpitol or methyl-substituted dibenzylidesi solpitol O is effective for improving the transparency of low-visibility polyethylene resins (41 Kosho 45-22008%, 021
No. 1023190).

However, there is room for improvement in the various effects of conventional nucleating agents, including the effect of improving transparency. Although nine methyl-substituted dibecidiliden salts have excellent improvement effects, they are incorporated into low-density polyethylene resins and suffer from the drawbacks of sibly lead-out.

The present inventors have conducted various studies on a new nucleating agent that can exhibit a more effective modification effect than the above-mentioned known nucleating agent and eliminate drawbacks such as bleed-out.

As a result, we discovered that a compound represented by the following general formula (DK) exhibits an extremely excellent nucleating effect on low-density polyethylene, and that this effect is also exhibited in the same way on linear low-density polyethylene. The present invention was finally completed.

That is, the present invention is directed to linear low-density polyethylene resin or
For polyethylene, the general formula [wherein X represents a hexagen atom or a 1-io lower alkyl group], when X is a halogen atom, the tortoise represents an integer of t-S, and X represents a lower alkyl group indicates an integer between 2 and 5. 2 companies 0 and #ii are shown. The present invention relates to a method for modifying a low-density polyethylene resin, which comprises blending a compound represented by the following.

According to Honji'@, the manufacturing process of low-density poly-I resin molded products O is based on the conventionally used precedent (1%/-h of the above general formula C).
Based on the fact that the specific metal compound represented by I) is blended, the compound functions as a nucleating agent for linear low density polyethylene or low density polyethylene 2/, and improves the original transparency, surface gloss, etc. In this way, a resin is obtained which exhibits an improvement effect, an effect of shortening the molding speed, etc., and has extremely excellent elastic properties without causing defects such as bleed-out.

In the compound represented by the above general formula (I) used in the present invention, the hegen atom defined by X includes chlorine, bromine,
Examples of the iodine or fluorine atom and lower alkyl groups having 1 to 5 carbon atoms include methyl, ethyl, propyl, and isopropyl groups, respectively. α).

Preferred substituents represented by are, for example, diethyl, diethyl, trimethyl, pentamethyl, traethyl,
0, jig 00. Examples include ``Pot'' and ``Full 1 Rokigin''. It can be easily prepared by condensing the compound of general formula (I), turditol or medium silitol, with a substituted benzaldoxide having the above substituent group in accordance with a conventional method.

The desired effects of the present invention can be achieved by blending the above compounds into low-density polyethylene resin;
The following ethylene copolymers or ethylene copolymers having an ethylene content of 5011 or more are included. Any of the various materials that can be copolymerized with Kotsumar Echireshi, which can constitute the above-mentioned copolymer, can be used. Typical copolymers include x9shin/vinyl acetate, ethylene/methacrylate,
Ethylene/acrylate, ethylene/--olefin (
(Latin, propylene, hexose, octyl, etc.) can be exemplified. The polyethylene resin of the present invention also includes linear low-density polyethylene resin. The amount of the compound represented by the general formula (I) in the low-density polyethylene resin is not particularly limited, but is usually about 0. .03-3% by weight
, preferably about 0.05 to 2 weight, and ζ
The intended effects of the present invention can be sufficiently exhibited by blending within 0[1M.

The method of the present invention employs conventional Ki
The method of compounding the above-mentioned compounds can also be carried out in the same manner as the compounding of known nucleating agents.

For example, the 7O apricot may be directly blended into powdered resin pellets, or may be blended with the resin in advance and made into pellets. In blending these, it is no different from the conventional method that a conventional vacuum cleaner, extruder, and 0-5-1110fls combiner can be used.

The molding operation after compounding can be carried out by heating under temperature conditions that melt the resin, according to a conventional method.

When molding the above resin, commonly used stabilizers, lubricants, antioxidants, antistatic agents, fillers, dispersants, pigments, foaming agents, etc., and the addition of high-density polyethylene, polypropylene, etc. There is no problem with the addition of O such as pyrene, polybutene, polybutene, liptadiene, etc. Examples and comparative examples of the present invention will be described below.

Note that the middle part or - on each side is based on weight.

Example· ! 70 parts of a linear low-density polyethylene resin containing BHTo and 1- as an antioxidant (manufactured by U.S. LiI Tauke! Cal's, ethylene plastic polymer with a content of about 9511 II, 0.955 f/d per degree) or to 80 parts, di(2,4-dimethylbensyridasi)tsurue)-L
ol*? 25-batch (LDPK 99 phr and di(2,4-dimethylbensyridasi) tulpitoh tph
30 or 20 parts of molten hardware) were added, melted and mixed at 220°C, and the resulting mixture was molded by an air cooling method using an inflation molding machine to create a blown film with a film thickness of 50 μm.

Examples 2 to 7 Films were prepared in the same manner using the following compounds in place of the dimethyl-substituted dibecizal sorbitol used as the nucleating agent in Example tVc above.

Example Comparative example of nucleating agent used 1 A film was prepared in the same manner as in Example IKTh, in which a compound to be used as a nucleating agent was blended.

Comparative Example 2 The same procedure as in Example 1 was carried out using the same amount of di(P-methylbesidylidene) sorbitol as a nucleating agent.

The haze of the nine films obtained in the above six examples was determined by ASTM D-10.
Measured according to 03-52. The results are below! Show IK.

Table 1 The blank mark in Comparative Example 2 in Table 1 indicates that lead was observed.

Examples 8 to 14 Low density polyethylene containing BHlo, 1- as an antioxidant (Nippon Unica I1.d-0,923, MI=3.
2>, a predetermined amount of each of the same compounds used in Examples 1 to 7 as a nucleating agent was added thereto, and heated at 11K to a thickness of 5.
Create a blown film of 0μ凰.

Comparative Example 3 In Examples 8 to 14 above, without using a nucleating agent,
A film was made in the same way.

The haze degree of each film obtained was measured in the same manner as described above, and the results are shown in Section 21 Ik below.

Table 2 Examples 15 to 19 Predetermined amounts of each of the compounds shown in Table 3 below were added as a nucleating agent to the same linear low-density polyethylene resin as in Example 1, and each compound was milled in a twin-screw mill at 220°C. The mixture was melt-mixed and press-formed at 170°C for 5 minutes at 50Kt/ai, then cooled to room temperature to produce a sheet of one thickness.

Comparative Examples 4 and 5 In each of the above Examples, either no nucleating agent was added (Comparative Example 4) or 1. Sheets were prepared in the same manner using the prescribed amounts of - and (F-methylbesidylidecyl)turjitol O.

The degree of haze of each sheet obtained was measured in the same manner and the results are shown in Table 3 below.

Table 3 From Tables 1 to 3 above, it can be seen that according to the present invention, a resin product having superior transparency compared to the case without additives can be obtained, and there is no possibility of bleeding occurring. On the other hand, as shown in Comparative Examples 2 and 5 using the known di-(P-methylbenzyridushi)sorbitol, the haze improvement effect is still insufficient or bleeding occurs, which is undesirable. I understand (more than that)

Claims (1)

[Scope of Claims] ■ A bell-shaped low-texture polyethylene resin or a low-texture polyethylene resin having a general formula [wherein X represents an Of atom or a lower alkyl group having 1 to 5 carbon atoms, and 〇When the atom atom O is an integer of 1 to 30, and when the atom X is a lower alkyl group O, an integer of 2 to 50 is shown. P represents 0 or l. ] A method for modifying a low-strength polyethylene resin, which comprises blending a compound represented by the following.