JPH0443929B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a granular masterbatch containing, for example, 5% by weight or more of a fragrance. Conventionally, colored master batches of polyolefin containing a high concentration of inorganic pigments have been manufactured using extruders, etc. because the inorganic pigments are powders, so they can be easily dispersed into polyolefin powders, and they do not decompose or dissipate due to heat. could be pelletized relatively easily.

However, when manufacturing a liquid composition, for example, a pellet masterbatch containing a fragrance in polyolefin powder at a high concentration, the fragrance has difficulty dispersing into the polyolefin powder due to its liquid state, and furthermore, when pelletizing with an extruder, etc. ,
This method could not be adopted because the boiling point of the fragrance is lower than the softening temperature of the polyolefin, and therefore the heat dissipation rate is high.

As a method for solving the above problem, a method is known in which a fragrance is adsorbed onto an inorganic filler such as fine silica powder, blended with polyolefin powder, and pelletized using an extruder or the like to obtain the desired substance.
However, when inorganic fillers such as silica are added to polyolefins, they generally reduce the transparency, gloss, etc. of the molded products obtained, and since inorganic fillers themselves contain several percent water, they cannot be used in extrusion or injection molding. The reality is that foaming sometimes occurs, making it impossible to obtain a satisfactory molded product.

On the other hand, there is a method in which a large amount of fragrance is contained in a porous polyolefin pellet having a high porosity. The masterbatch obtained by this method can be blended in a few percent with polyolefin impellets and then extruded or injection molded, and it is possible to obtain fragrant plastic molded articles with less fragrance loss.

However, since special techniques are required for the manufacturing process of the porous polyolefin and the process of incorporating the fragrance, high costs are unavoidable.

In view of the above-mentioned circumstances, the inventors of the present invention have deeply studied the production of inexpensive granular masterbatches that have a high fragrance content, less fragrance escape during molding, and have decided to use a specific ethylene copolymer powder. The inventors have discovered that this object can be achieved by the following methods and have arrived at the present invention.

That is, the present invention provides a granular fragrance-containing masterbatch obtained by adding 50 parts by weight or more of a fragrance to 100 parts by weight of ethylene-vinyl acetate copolymer powder, kneading with high speed stirring, and then adding polyolefin powder and stirring at high speed. It is.

According to the present invention, it is possible to provide a granular masterbatch containing a fragrance at a high concentration at a low cost, and since this masterbatch has a granular shape, it can be easily blended with general polyolefin pellets.

Furthermore, fragrance is less likely to escape during thermoforming such as extrusion or injection molding, and fragrant plastic products can be easily provided without deterioration of appearance and physical properties.

The ethylene-vinyl acetate copolymer powder (hereinafter abbreviated as EVA powder) used in the present invention is:
It usually contains 5 to 45% by weight of vinyl acetate, and also includes modified resins thereof.

In addition, polyolefin powders include polypropylene, polypropylene-ethylene copolymer,
Examples include porous powders of low density polyethylene, medium density polyethylene, high density polyethylene, and the aforementioned polyolefins, but materials other than polyolefin powders can also be used as long as they are compatible with EVA. Further, as for fragrances, generally commercially available ones can be used, and there are no particular limitations. For example, lemon oil,
Natural fragrances such as lavender oil and menthol, synthetic fragrances such as α-pinene, camphene, limonene, and methyl salicylate, and blended fragrances of these fragrances can be used.

Conditions for producing a good granular masterbatch depend on the blending ratio of EVA powder and fragrance and the amount of polyolefin powder added. That is, it is important to impregnate 100 parts by weight of EVA powder with 50 parts by weight or more, preferably 100 parts by weight or more, of fragrance to form a gel. If it is less than 50 parts by weight, it will not become gel-like, and even if polyolefin powder is added later, it will be difficult to form granules.

The amount of polyolefin powder to be added is preferably as small as possible so that the masterbatch has a high concentration of fragrance content under granular conditions. i.e.
It is usually preferable to add 100 parts by weight or more to 100 parts by weight of a gel composition consisting of EVA powder and fragrance. If the amount of polyolefin powder added is less than 100 parts by weight, a sticky granular masterbatch will be produced, which is not preferable. At this time, this tendency can be slightly improved by adding a small amount of a lubricant such as stearic acid or calcium stearate, but it is preferable to add at least 100 parts by weight or more, preferably 150 parts by weight or more. However, when porous polyolefin powder is used, the bulk specific gravity is smaller than that of general polyolefin powder, so a granular masterbatch without stickiness can be obtained even with less than 100 parts by weight. In this case, the porous polyolefin powder is
Examples include Accurel powder manufactured by Armak. The fragrance content of the fragrance-containing granular masterbatch obtained by the above method is usually in the range of 5 to 30% by weight when a general polyolefin powder is added, and 5 to 60% by weight in the case of a porous polyolefin powder.

The fragrance content defined here is the weight of the fragrance divided by the total weight of the fragrance, polyolefin powder, and EVA powder, multiplied by 100. Furthermore, masterbatches usually consist mainly of granules with a diameter of 1 to 5 mm, and are generally about the same size as resin pellets, so blending is easy.

As the conditions for high-speed stirring used in the present invention, a high-speed stirring capacity easily obtained by using a commonly used Henschel mixer is sufficient, and no special conditions are required. Nor is it limited to the use of shell mixers.

The granular fragrance-containing masterbatch obtained according to the present invention is useful when a fragrance-containing molded article is obtained by incorporating a fragrance into a polyolefin-based molded article molded by extrusion molding, injection molding, or the like.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 10 Put 60 g of EVA powder (manufactured by Tokyo Ink Co., Ltd., trade name Thermotatsu 8050c) into Henschel (manufactured by Tokyo Ink Co., Ltd., product name: Thermotatsu 8050c), and add fragrance (manufactured by Hasegawa Fragrance Co., Ltd., product name: Mis −1333) 90g per minute
A gel composition was obtained by stirring at 1000 rpm for 30 seconds. Furthermore, 250 g of polypropylene powder (manufactured by Mitsui Toatsu Chemical Co., Ltd.) was added and stirred at 1000 revolutions per minute for 30 seconds to obtain a granular masterbatch. 6 parts by weight of the masterbatch with a fragrance content of 22% was blended with 100 parts by weight of propylene-ethylene copolymer (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name: Mitsui Noblen MJS-G), and a 0.5 mm thick sheet was produced using an extruder. Manufactured.

A sheet with a lasting aroma was obtained. There was no foaming, the appearance of the sheet was good, and there was no deterioration in the physical properties of the transparent sheet.

Example 2 In Example 1, porous powder manufactured by Armak (trade name) was used instead of polyolefin powder.
Add 30g of Accurel (empty rate 80%) and fragrance content 50
% granular masterbatch was obtained. 2 parts by weight of the above masterbatch was blended with 100 parts by weight of polypropylene (Mitsui Noblen JH-G, manufactured by Mitsui Toatsu Chemical Co., Ltd.), and a pen plate was molded using an injection molding machine. This molded product maintained its aromatic properties to the extent that almost no change was observed even after 6 months.

Example 3 In the same manner as in Example 1, 20 g of stearic acid, 150 g of polypropylene powder (manufactured by Mitsui Toatsu Chemical Co., Ltd.) was added to obtain a masterbatch with a fragrance content of 28%. 4 parts by weight of the above master batch was blended with 100 parts by weight of polypropylene (manufactured by Mitsui Toatsu Chemical Co., Ltd., Mitsui Noblen FL-100) to produce an inflation film with a thickness of 30 μm. The film was aromatic and had a good appearance.

Comparative Example 1 In Example 1, 90 g of fragrance was added to 60 g of polypropylene powder without using EVA powder, but a gel-like composition was not obtained but a suspension, and even when polypropylene powder was further added, it did not become granular. .

Comparative Example 2 In Example 1, 60g of EVA powder and 90g of fragrance
250 g of polypropylene powder was added at once and stirred at 1000 revolutions per minute, but the masterbatch did not become granular and a powder-like masterbatch was obtained.

Claims (1)

[Claims] 1 Ethylene-vinyl acetate copolymer powder 100
A granular fragrance-containing masterbatch obtained by adding 50 parts by weight or more of a fragrance to the parts by weight, stirring and kneading at high speed, and then adding polyolefin powder and stirring at high speed.