KR19980034312A - Manufacturing method of synthetic resin which preserves fragrance long - Google Patents

Abstract

The present invention relates to a method for producing a synthetic resin that preserves fragrance for a long time.

The present invention has a technical problem that the fragrance is added to the synthetic resin as much as possible while minimizing the deformation of the synthetic resin during molding, and to meet the various conditions that the fragrance divergence amount should be maintained for an appropriate period.

That is, the present invention is 20 ~ 30% by weight impregnated liquid ethylene vinyl acetate (EVA) resin (vinyl acetate 20 ~ 30%), low density polyethylene (LDPE) resin and high density polyethylene (HDPE) resin 20 ~ 30: 50 ~ 60: 10: 20 is a method of producing a long-lasting synthetic resin, characterized by melting and molding by mixing in a weight ratio of.

The synthetic resin molded article according to the present invention is suitable for molding an outer frame of an automobile interior directional ornament or an automobile air filter.

Description

Manufacturing method of synthetic resin which preserves fragrance long

The present invention relates to a method for producing a synthetic resin that preserves fragrance for a long time.

Synthetic resins with aromatic properties can be widely used in various indoor props, accessories, and grippers of air filters, and are very useful in that they can emit scent without a separate fragrance box.

In particular, when molding the decoration provided in the interior of the car with such a material, it is not necessary to consider the flavor box will have the advantage that the design of the decoration can be changed more and more diversely.

However, the problem is that the duration of the fragrance should be maintained for a considerable period of time. In order to maintain this persistence, a very effective fragrance injection method must be followed, and the surface of the synthetic resin formation becomes coarse or deformed during the molding process due to the addition or mixing of the fragrance. Should be considered together.

Although this type of synthetic resin has been known in the past, they are either a method of mixing together a synthetic resin and then dissolving together before forming a small amount of powder fragrance, or a method of forming a small amount of liquid fragrance mixed with the synthetic resin so that the fragrance may be emitted from the synthetic resin. However, since the fragrance could not be added enough to prevent moldability deteriorated temporarily, the fragrance is temporarily divergent enough, but only a small amount of fragrance is not emitted, so it is not utilized for various purposes.

The present invention has a technical problem to meet the various conditions that the fragrance is added to the synthetic resin as much as possible while minimizing the deformation of the synthetic resin during molding and maintaining an appropriate degree for a considerable amount of perfume.

In order to solve this problem, to select a fragrance having affinity for synthetic resin and physical properties, to select a synthetic resin that can contain a large amount of fragrance and the fragrance can be effectively and long-term, the fragrance and the synthetic resin can be effectively combined. The choice of specific conditions, the formulation and the ratio of the formulation to minimize the change and the physical properties of the plastic molding should be presented.

The present invention will contribute to providing excellent synthetic resin moldings in which strong fragrances are long preserved by addressing these various conditions.

The configuration of the present invention will be described in detail according to the manufacturing process.

[First step (impregnation step)]

Ethylene Vinyl Acetate (hereinafter referred to as soft EVA) particles having a content of 20 to 30% of vinyl acetate in liquid perfume is stirred for 3-4 hours under a temperature condition of 20 to 30 ° C. The liquid perfume is allowed to impregnate the soft EVA particles with a weight ratio of 20-30%. It is important to choose a type of soft EVA that can be easily and sufficiently impregnated with liquid fragrances.

Solvents in liquid fragrances are easily vaporized by heat, so vaporization is faster than impregnation at temperatures above 25-35 ℃, and impregnation is less effective at lower temperatures than molecular activities of liquid fragrances.

The impregnation time is slightly different depending on the type of fragrance and EVA, but it is optimal to impregnate about 20-30g of liquid fragrance with 100g of soft EVA. This is because if the impregnation ratio of the liquid perfume exceeds 30% (w / w), bubbles are formed in the moldings or deformations are made on the surfaces of the moldings during molding in the next step, and thus the desired moldings cannot be obtained. The maximum impregnation rate of the liquid perfume is up to 80% (w / w). In addition, if the impregnation ratio of the liquid perfume is 20% (w / w) or less, there is a problem in maintaining the persistence of the fragrance.

EVA having a content of vinyl acetate of 30 to 60% (hereinafter referred to as hard EVA) has a dense physical property, so the impregnating effect of liquid perfume is low, so that the liquid impregnation weight ratio does not exceed 20%.

However, some of the low density polyethylene (hereinafter referred to as LDPE) with a high density of 0.91 to 0.93 g / cm 2 have a high liquid impregnation ratio, so that LDPE can be replaced with EVA. However, PVC (Polyvinyl chloride) is excluded from the selection because it is unsuitable for impregnation of liquid perfume.

Second Process (Mixed Process)

Soft EVA impregnated with liquid fragrance of 20-30% by weight, LDPE, and High Density Polyethylene (hereinafter referred to as HDPE) having a density of 0.95-0.97 g / ㎠ (hereinafter referred to as HDPE) by weight ratio 20-30: 50-60 : Mix in proportion of 10-20.

It is complimentary that soft EVA impregnated with liquid perfume is degraded due to impregnation of liquid perfume.

HDPE is necessary for the purpose of increasing the tensile strength of the entire molding and improving the moldability during injection.

EVA and PE (polyethylene) are various types, but when mixing and dissolving, it is necessary to select ones that are excellent in fusion with each other in terms of physical properties, and EVA and PE of various liquid flavoring solvents and physical properties without rejection should be selected.

[3rd process (molding and injection process)

After mixing liquid EVA impregnated soft EVA, LDPE, and HDPE in the above-mentioned mixing ratio, they are melted under the temperature of 140-150 ℃ as in the case of general injection, and then injected into the injection machine.

In the following Examples the present invention will be described in detail. However, the present invention is not limited only to these examples.

Example 1

100 g of soft EVA (vinyl acetate content 25%) particles were immersed in 30 g of liquid perfume (containing 9.6% of ester), followed by stirring for 3 to 4 hours at a temperature of 30 ° C.

Resin mixture 145 ° C. mixed with soft EVA, LDPE (density: 0.918 g / cm 2), and HDPE (density: 0.968 g / cm 2) impregnated with 25% by weight of liquid perfume in a weight ratio of 25: 55: 20. After fusing at, it was put into an injection molding machine to prepare a synthetic resin molded product having a homogeneous, glossy and directional surface having a diameter of 35 mm and a height of 8 mm.

Example 2

In order to test the fragrance persistence of the synthetic resin molded product (hereinafter referred to as the present product) prepared in Example 1 and the commercial liquid air freshener, the present product and the commercial product were left in a well-ventilated and ventilated room at 25 ° C. to 30 ° C. For 10 days, panelists, who had no sense of product development and well developed sense of smell, were subjected to sensory evaluation on a 5-point scale, and the results are shown in Table 1.

[Table 1] Sensory test results

Note 1). Commercial product 1: Oxy, Inc.

Note 2). Commercial product 2: Oxy, Green Inc.

Note 3). The above figures are average values based on a five-point scale method (1: very bad, 2: bad, 3: normal, 4: good; 5: very good).

Example 3

In order to find out the proper resin compounding ratio of the synthetic resin product according to the present invention, by controlling the compounding ratio of soft EVA, LDPE and HDPE, the moldability (surface homogeneity, glossiness) and the orientation of the synthetic resin molding were investigated. Star formability and orientation are shown in Tables 2 and 3.

[Table 2] Resin Mixing Ratio

[Table 3] Moldability and aromaticity by resin blending ratio

Note) +++: Very good, ++: Good, +: Normal,-: Poor

The resin molded article of the present invention molded through each of the above steps has soft physical properties as a whole, but has sufficient moldability and glossy surface required for synthetic resin molded articles.

When manufacturing a disc shaped molding having a diameter of 35 mm and a height of 8 mm using the synthetic resin of the present invention, as shown in Table 1, the fragrance sufficient to feel a normal smell in the interior of a car lasted for 20 days or more, and after 25 days, the directionality Although it was lowered, it was confirmed that it emits a mild fragrance for more than two months.

To increase the directionality, the volume of the molding must be increased, in particular the surface area of the molding must be increased. Therefore, if the molded article for the car interior is enough to replace the fragrance, the volume of up to three times the disk shape and the surface area of up to two times can retain the proper fragrance for two months or more.

The aromatic synthetic resin according to the present invention can be widely used in aromatic moldings close to consumables, and can be reused by being easily recovered by being impregnated with liquid perfume even after the fragrance is exhausted.

Claims (2)

Ethylene vinyl acetate (EVA) resin, low density polyethylene (LDPE) resin, and high density polyethylene (HDPE) resin with 20-30% vinyl acetate impregnated with liquid fragrance at a weight ratio of 20-30: 50-60: 10-20. A method for producing a long-lasting synthetic resin, characterized by melting and molding by mixing. The resin of claim 1, wherein the ethylene vinyl acetate resin is immersed in the liquid perfume for 3-4 hours at a temperature of 25-35 ° C. so that the liquid perfume is impregnated in a 20-30% weight ratio. Manufacturing method.