JPS58196247A - Polyolefin composition - Google Patents

Abstract

PURPOSE:To prepare the titled composition having improved moldability and giving a molded article with good surface appearance, by adding a specific fluoroalkyl group-containing compound as a lubricant to a polyolefin. CONSTITUTION:The objective polyolefin composition is prepared by mixing (A) 100pts.wt. of a polyolefin (e.g. ethylene polymer) with (B) 0.05-2.0pts.wt. of the compound of formula (R is alkyl or metal; n and Z are integer; m is 0 or integer). The mixing is carried out either by mixing the components by a Henschel mixer, and kneading by an extruder under melting, or by dissolving the compound in a hydrocarbon or aromatic solvent and mixing the solution with a polymer solution. EFFECT:A good moldability and the prevention of the surface roughening of molded article can be attained even in a polyolefin having high molecular weight and narrow molecular weight distribution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyolefin composition with improved moldability and a good surface condition of molded articles. Furthermore, it relates to a polyolefin composition containing a novel lubricant.

It is known to add a lubricant to improve the moldability of polyolefins when they are melted. In particular, recently, in order to improve the mechanical strength of polyolefins, such as impact strength, drop strength, stress cracking resistance, linear strength, and knot strength, polyolefins have been made to have higher molecular weights and narrower molecular weight distributions. ing. But on the other hand,
Such high molecular weight and narrow molecular weight distribution lead to an increase in melt viscosity, and in the case of extrusion molding such as film molding, monofila molding, blow molding, and pipes, molding may become impossible2 or even if molding is possible, molding may be difficult. There are problems such as an increase in torque and roughening of the surface of the molded product. Furthermore, in the case of injection molding, short shots and uneven gloss of the molded product may occur. For this reason, proposals have been made to improve moldability by adding various lubricants. However, even if commonly used alkaline earth metal salts of higher fatty acids, such as calcium stearate, 12- and calcium distearate, etc., are blended, especially in the case of polyolefins with high molecular weight and narrow molecular weight distribution as mentioned above, However, there is a problem in that the molding processability and the skin condition of the molded product are not significantly improved, and if a large amount is added to increase the lubricant effect, bleed-out occurs.

Other compositions containing alkali metal salts of higher fatty acids have also been proposed, but they have not yet achieved sufficient moldability and surface condition of molded articles.

In view of the current situation, the present inventors have conducted extensive research into lubricants that can provide good molding processability for polyolefins, particularly polyolefins with high molecular weight and narrow molecular weight distribution, and can prevent surface roughness of molded products. The general formula (CnHmF2n+1-mC
00) It has been discovered that the above-mentioned problems can be solved by using the compound (A) represented by zR as a lubricant, and the present invention has been achieved.

That is, the present invention relates to polyolefins and the general formula %) (wherein R is an alkyl group or a metal group, "SZ is an integer, m
is a polyolefin composition characterized by comprising a compound (A) represented by R (0 or an integer when R is an alkyl group, and an integer when R is a metal group).

It is known that the 70-roalkyl group is used to improve water and oil repellency, improve mold release properties, and improve antistatic properties due to its low surface energy. For example, it is shown in JP-A-54-14457 that fluoroalkyl polyoxyethylene ethanol is effective in preventing static electricity on vinyl chloride resin. Furthermore, it was shown in Japanese Patent Publication No. 55-23271 that a phosphoric acid ester containing a per-70-roalkyl group is effective as a mold release agent for highly adhesive urethane resins and epoxy resins, that is, as a coating agent that makes it easier to release polymer solids from molds. has been done. Further, Japanese Patent Publication No. 43-4503 discloses water and oil repellency. However, the general formula (OHP (!00
) It is true that the compound (A) represented by R maintains compatibility with polymers and thermal stability that are not found in mold release agents, and improves fluidity during melting. This was revealed for the first time by the inventors.

The compound used as a lubricant in the present invention has the general formula % (% formula %) (wherein R is an alkyl group or a metal group, nSz is an integer, m
is a compound represented by 0 or an integer when R is an alkyl group, and an integer when it is a metal group.

Here, n is preferably 4 to 17. R is, for example, an alkyl group such as a methyl group, ethyl group, propyl group, butyl group, or isopropyl group, or a group IA group such as lithium, sodium, and potassium, a group IA group such as magnesium, calcium, and strontium, and a group IB group such as zinc and cadmium. , a group A metal group such as aluminum. m is 0 or an integer when R is an alkyl group, and is an integer when R is a metal group.

If m is an integer, the upper limit is 2n.

In the present invention, the polyolefins to be blended with the compound (shu) include ethylene, propylene, 1-butene, 1-hexene,
It is a homopolymer of 4-methyl-1-pentene, 3-methyl-1-pentene, etc., or a copolymer consisting of two or more types of comonomers. In the case of a copolymer, it may contain a polyunsaturated compound such as a conjugated diene or a non-conjugated diene as a copolymer component. Alternatively, any polyolefin may be used, such as a mixture of these polymers. Among these, those with high molecular weight and narrow molecular weight distribution exhibit particularly remarkable effects of the present invention, but of course, those with low molecular weight and wide molecular weight distribution also exhibit good effects.

The blending ratio of the polyolefin and the compound (4) is 5 to 2.0 parts by weight of the compound (4) per 100 parts by weight of the polyolefin. If it is less than 0.05 parts by weight, the effect of improving molding processability or the surface condition of the molded product will be small, and if it exceeds 2.0 parts by weight, it will not only be economically disadvantageous, but also cause damage to some parts of the extruder screw. Slip property increases, molding processability decreases, and bleed-out also tends to occur. The compound (A) to be blended may be used alone or in combination of two or more.

Various known methods can be used to blend the polyolefin and compound (A). For example, each component is mixed using a ribbon blender, tumbler blender, Henschel mixer, etc., and then melt-mixed using an extruder, Banbury mixer (1/2 rolls), etc., or dissolved in a hydrocarbon or aromatic solvent to form a polymer solution. An example is a method of mixing.

In addition, the polyolefin composition of the present invention includes weathering stabilizers, heat stabilizers, antistatic agents, antifogging agents, antiblocking agents, slip agents, pigments, dyes, etc., which are commonly added to polyolefins. Various compounding agents may be blended within the range that does not impair the purpose of the present invention.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way unless the gist of the invention is exceeded.

Examples 1 to 5 and Comparative Example 1 Dilauryl thiodipropinate and 6,5-di-propionate as stabilizers were added to 100 parts by weight of polyethylene having a density g O-954 g/c1R' and a melt index of 1.0 g710 m1H measured at 190°C. 0.3 parts by weight and 0.1 parts by weight of t-butyl-4-hydroxytoluene, respectively, and 1 part by weight of the compounds shown in Table 1 were added to an extruder with a screw diameter of 20111111φ and L/D=26. The mixture was granulated at 200°C. Granulated polyethylene was attached to an extruder with a screw diameter of 20 mmφ and a nozzle of L/D = 15 with a nozzle diameter of 1 mmφ and L/D = 15, and the screw rotation speed was changed at a resin temperature of 260°C using a full flight type screw. Extrusion molding was carried out with the extrusion amount (8
Measure the extrusion pressure CkQ/noodles 2) for 7mln),
At the same time, the surface smoothness of the extruded product was observed. Results first
It is shown in the table and FIG.

In addition, the surface smoothness referred to here means that the molded product has a smooth and glossy surface when visually inspected, ○, and the melt index measured at 230°C for Surface Examples 6 to 7 and Comparative Example 2 is 1-2 g/
100 parts by weight of polypropylene at 10 min, Irganox 1010 and 3,5-di-t-
The same procedure as in Example 1 was carried out by adding 0.1 part by weight of butyl-4-hydroxytoluene and further adding 1 part by weight of the compounds shown in Table 2. results

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the present invention and a comparative example. Applicant: Mitsui Petrochemical Industries, Ltd. Agent Yamaguchi Kazu

Claims (2)

[Claims] (1) Polyolefin and general formula % formula %) (wherein, R is an alkyl group or a metal group, n%2 is an integer,
m is 0 or an integer when R is an alkyl group, and an integer when R is a metal group. (2) Compound (A) per 100 parts by weight of polyolefin
) in an amount of 0.05 to 2.0 parts by weight.