JPS5993710A - Preparation of polypropylene resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin having high impact resistance and giving an injection molded article free from flow mark and unevenness of luster, by reacting a polypropylene resin with specific amounts of a vinylpyridine compound (derivative) and an organic peroxide. CONSTITUTION:100pts.wt. of a polypropylene resin is mixed thoroughly with 0.1-5pts.wt., preferably 0.5-3pts.wt. of a vinylpyridine compound (preferably 2-vinylpyridine, 4-vinylpyridine or 3-vinylpyridine) or its derivative [preferably 2- methyl-5-vinylpyridine or 5-ethyl-2-(methyl)vinylpyridine], and 0.05-0.5pt.wt., preferably 0.1pt.wt. of an organic peroxide [preferably dicumyl peroxide, 2.5- dimethyl-2.5-di(t-butylperoxy)-hexane, or azobisisobutyronitrile]. The mixture is kneaded under melting preferably at 170-250 deg.C for 1-10min to effect the grafting reaction and obtain the objective resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polypropylene resin with improved impact resistance.

In general, bittern propylene resin has mechanical properties.

Although it is used in a wide range of fields because it has excellent moldability and is relatively inexpensive, it is not necessarily satisfactory in terms of impact resistance. As a method for improving the impact resistance of polypropylene resins, polyethylene, ethylene-propylene copolymer rubber, ethylene-propylene-diene ternary copolymer, ft-combined rubber, Z-Lz7-acid-resistant vinyl copolymer, styrene-based resin, etc. It has been proposed to mix butadiene plotter copolymer rubber and the like. Although such polypropylene compositions have improved impact resistance, they have the disadvantage that rigidity and heat resistance are greatly reduced, and flow marks and uneven gloss occur in injection molded products.

In view of the above, the present inventors have conducted intensive research and have found that impact resistance can be improved by reacting a vinylpyridine compound with polypropylene, thereby providing the present invention.

That is, the present invention provides a polypropylene having impact resistance characterized by melt-kneading 01 to 5 parts by weight of a vinylpyridine compound or its derivative and 0.05 to 05 parts by weight of an organic peroxide to 100 parts by weight of a polypropylene resin. This is a method for producing a resin.

Conventionally, in order to improve adhesion, paintability, printability, etc., which are disadvantages of polypropylene and polyolefin resins, it has been necessary to graft-react various polar polymers to the polyolefin resin to introduce polar groups into the molecule. is being attempted. For example, there is a method of grafting polypropylene with maleic anhydride or acrylic acid. However, in general, when a polar monomer is grafted onto polypropylene, the mechanical properties such as impact resistance and rigidity decrease. By grafting a selected vinylpyridine compound or its derivative onto polypropylene, it is surprisingly possible to produce injection molded products without any loss in rigidity or heat resistance, and without the occurrence of flow marks or uneven gloss on injection molded products. Impact resistance can be significantly improved.

The present invention provides a method for improving the resistance of polypropylene resins.

The polypropylene resin used in the present invention is one that is commonly used and is not particularly limited. For example, there are copolymers of propylene and other α-primary/fins, such as propylene homopolymers, ethylene-propylene block copolymers, or random copolymers.

Examples of vinylpyridine compounds used in the present invention include 2-vinylpyridine, 4-vinylpyridine, and 3-vinylpyridine, and derivatives thereof such as 2-vinylpyridine, 4-vinylpyridine, and 3-vinylpyridine.
Examples include methyl-5-vinylpyridine, 5-ethyl-2-vinylpyridine, and 5-ethyl-2-methylpyridine. The above compounds may be used alone or in combination of two or more. The amount used is polypropylene resin 100%
The amount is preferably 0.1 to 5 parts by weight, and most preferably 0.5 to 3 parts by weight. If it is less than 0.01 parts by weight, there is no effect of improving impact resistance, and if it is more than 5 parts by weight or 11 parts by weight, the vinylpyridine compound and its derivatives are in a liquid state and mixing is difficult.

Moreover, it is not sufficiently effective.

Furthermore, the organic peroxide used in the present invention is:

Any material that promotes the grafting reaction between polypropylene resin and vinylpyridine compound or its derivatives is acceptable.
For example, penzoyl peroxide, dicumyl peroxide, lauryl peroxide, azobisin butyronitrile, α, α1-bis(t-y'tilveroxydiimpyl)benzene, 2,5-dimethyl- 2,5
-di(t-butylperoxy)hexane, 25-dimethyl-25-di(1-butylperoxy)hexane-
3, di-t-butyl peroxide, t-butyl hydroperoxide, etc. are used. The above organic peroxides may be used alone or in combination of two or more. The amount used is 1 to 5 parts by weight of polypropylene resin and 0.05 parts by weight.
~0.5 part by weight is preferred. In particular, the effect of improving impact resistance is most exhibited at around 081 parts by weight. If the amount is less than 0.05 parts by weight, the grafting rate of beer pyridine or its rust conductor will be low and there will be no effect. o, if it is over the s weight it part, it will melt 7
0-index increases, mechanical properties (impact resistance,
(rigidity, etc.) decreases.

The present invention may also contain commonly used fillers (for example, calcium carbonate,
Talc, mica, clay, wollastonite, silica,
alumina.

Glass powder, glass fiber 7 carbon fiber, wood powder.

Aluminum hydroxide, water (blinded magnesium.

+i%j acid barium, sulfite, aluminum powder, titanium oxide, etc. are used. These charges
These agents may be used alone or in combination of two or more.

In addition, antioxidants, ultraviolet hilt absorbers, lubricants, nucleating agents, pigments, etc. may be included as necessary.

In the present invention, it is essential and important to carry out the grafting reaction by melt mixing in order to achieve the desired impact resistance. That is, the above-mentioned polypropylene resin, vinylpyridine compound or its derivative, and organic peroxide are thoroughly mixed in a tumbler-two-shell mixer or the like, and the mixture is heated to a temperature above the melting point of the polypropylene resin, generally above the melting point and below 280"C. The grafting reaction is carried out by melting and kneading at a certain temperature.

The method of melt-kneading is not particularly limited, but it can be carried out using, for example, a screw extruder, a Banbury mixer, a mixing roll, or the like. The temperature and time of melt cross-talk vary depending on the decomposition temperature of the organic peroxide used, but are generally 160-280°C for 0.3-30 minutes, preferably 170-250''C for 1-10 minutes. Note that melt-kneading may be performed in an inert gas stream.

Next, the present invention will be explained in detail by way of examples. In the Examples, each measurement item was measured based on the following method.

,' /l-) 7 ry-index: JIS
Izot impact strength according to K6758: JIS K71101c standard/
Base (with hatch) Bending test: JIS K7203 (C compliant) Appearance (flow mark, gloss unevenness) Evaluation by second sight Example Example: Edylenub P Pyrene Block Copolymer Tokuyama Polypro+ M S 6201M I-1,77! / 10 minutes ,
100 parts by weight of 2-vinylpyridine (ethylene content 25% by weight), 1 part by weight of 2-vinylpyridine, and 0.1 parts by weight of Ncumilva Oxide were mixed for 2 minutes in a Hesoshell mixer and melt-kneaded at 220°C using a 65-fin extrusion rock to form pellets. It was created.

A test piece was prepared from the obtained pellet using an 80z injection molding machine, and its physical properties were measured. The results are shown in Table 1.

Example 2 The same procedure as in Example 1 was carried out except that 4-vinylpyridine was used instead of 2-vinylpyridine. The results are shown in Table 1.

Example 3 The same procedure as Example 1 was carried out except that 2-methyl-5-vinylpyridine was used instead of 2-vinylpyridine. The results are shown in Table 1.

Example 4 In the ethylene-propylene block, polypropylene (Tokuyama Polypro; PN120.MI=1. Table 1 shows the results.

Comparative Example 1 A test piece of the ethylene/-bukpyrene noroc co-polymer used in MKN1 was prepared using an 80z injection molding machine, and its physical properties were measured. The results are shown in Table IVC.

Comparative Example 2 The same procedure as Example 1 was carried out except that 2-vinylpyridine was not used. The results are shown in Table 1.

Comparative Example 3 Example 1 except that dicumyl peroxide was not used.
I did the same thing. The results are shown in Table 1.

Comparative Example 4 Using IC maleic anhydride instead of 2-vinylpyridine
・The garden was the same as in Example 1 except for the garden.

The results are shown in Table IK.

Comparative example 5 80 y of polypropylene used in Example 4.

Test pieces were prepared using an injection molding machine, and physical properties were measured. The results are shown in Table IVC.

Margin below

Claims (1)

[Scope of Claims] (1) 100 parts by weight of a polypropylene resin, 0.1 to 5 parts by weight of a vinylpyridine compound or its derivative, and 0.05 to 0.5 parts by weight of an organic peroxide are melt-kneaded, and a graft reaction is carried out. (2) A method for producing a polypropylene resin, characterized in that the pyridine compound is 2-vinylpyridine, 4-vinylpyridine, or 3-vinylpyridine (3)
The manufacturing method (4) according to claim 1, wherein the vinylpyridine derivative is 2-methyl-5-vinylpyridine, 5-ethyl-2-vinylpyridine or 5-ethyl-2-methylpyridine. The thing is dicumyl peroxide. 2.5-Dimethyl-25-di(t-butylperoxy)-hexane or azobisisoduthyronitrile, the manufacturing method according to claim 1.