JPH02135166A - Plastic aerosol container - Google Patents

Abstract

PURPOSE:To obtain the title pressure container having excellent heat resistance by forming the container consisting of the cylindrical barrel, bottom, and shoulder and a part of which are integrally formed from specified polyester and reinforcing fiber material and orienting the reinforcing material in the height direction of the barrel in the barrel. CONSTITUTION:The container consists of the cylindrical barrel 1, bottom 2, and shoulder 3, one between the bottom 2 or shoulder 3 and the barrel 1 are integrally formed, and the other bottom 2 or shoulder 3 and the barrel 1 are sealed by fusion. The container is formed from the polyester made from an aromatic carboxylic acid and an alkylene glycol and the reinforcing fiber material mixed into the polyester. The reinforcing material is oriented mainly in the height direction of the barrel at least in the barrel 1. A nozzle mechanism 20 is then fixed to the container, and the pressure aerosol container having excellent heat resistance and a fine appearance is obtained. Further, polybutyleneterephthalate or polyethyleneterephthalate is preferable to use as polyester.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a plastic aerosol container, and more particularly to a plastic aerosol container with excellent heat and pressure resistance.

(Prior Art) It has been known for a long time that plastics are used to manufacture pressure-resistant containers such as aerosol containers.
Publication No. 6-2484 describes the production of containers that are impermeable to propellants and have excellent pressure resistance by molding plastic such as polyester within the thermoelastic temperature range below its melting point. There is.

Furthermore, small-capacity aerosol containers made of acrylonitrile-styrene resin are already in practical use.

(Problems to be Solved by the Invention) Although plastic aerosol containers may provide satisfactory results when used in ordinary homes, they have not yet been fully satisfactory in terms of heat and pressure resistance. for example,
Aerosol containers are sometimes left in the interior of a car, and in this case the temperature of the aerosol container can reach up to about 70°C. At such high temperatures, the pressure of the filled propellant increases significantly, and the plastic that makes up the container becomes soft, or even if not softened, becomes susceptible to thermal deformation, leading to cracking or rupture.

Therefore, an object of the present invention is to provide a plastic aerosol container with excellent heat and pressure resistance.

Another object of the invention is a plastic aerosol container which is resistant to propellants and filler contents and which exhibits excellent resistance to deformation and breakage even under storage conditions where heat and pressure act simultaneously. is to provide.

(Means for Solving Problems) According to the present invention, the cylindrical body includes a cylindrical body, a bottom, and a shoulder having a nozzle attachment opening, and one of the bottom and the shoulder is integral with the cylindrical body. a plastic aerosol container formed of a plastic aerosol container in which the other of the bottom and shoulder portions and the cylindrical body are melt-sealed; Provided is a plastic aerosol container comprising a fiber reinforcing agent blended into a cylindrical body, the fiber reinforcing agent being oriented primarily in the height direction of the body in at least the cylindrical body.

In the present invention, the polyester is 25 to 40%,
In particular, it is preferable to have a crystallinity of 30 to 40%, and the fiber reinforcing agent is preferably contained in an amount of 5 to 30% by weight, particularly 10 to 20% by weight, based on the total weight.

(Function) The plastic container of the present invention consists of a cylindrical body, a bottom, and a shoulder having a nozzle attachment opening, one of the bottom and the shoulder and the cylindrical body are integrally formed, and the bottom The other of the shoulders and the cylindrical body are melt-sealed, and each part of the container is made of polybutylene terephthalate or polyethylene terephthalate mixed with a fiber reinforcing agent, and at least the cylindrical body is made of fibers. A notable feature is that the reinforcing agent is oriented primarily in the height direction of the body.

The polyester formed from aromatic dicarboxylic acid and alkylene glycol used in the present invention can be used in various cosmetics based on propellants such as various freons (fluorocarbons), LPG (liquefied petroleum gas), dimethyl ether, alcohol, etc. It has the advantage of being resistant to kerosene-based insecticides, paints based on various solvents, etc. have

This is the reason why the polyester is selected as the plastic in the present invention.

Further, in the present invention, a fiber reinforcing agent is blended into the polyester, and the fiber reinforcing agent is oriented in the height direction of the body during molding of the container.

In other words, the orientation of such fiber reinforcing agents in the container structure provides satisfactory mechanical properties such as mechanical strength, rigidity, and impact resistance, and the container can be used under conditions where heat and pressure are applied simultaneously. Even when preserved, it shows excellent resistance to deformation and destruction, and the vessel wall surface becomes a smooth surface.
The appearance is also good.

In this case, if the fiber reinforcing agent is not blended and is dispersed in random directions, the molding shrinkage rate of the container wall (body) will be large, resulting in large shrinkage strain and reduced dimensional accuracy. However, the m contract characteristics also deteriorate. Furthermore, the wall surface of the container becomes rough, resulting in poor appearance characteristics.

(Preferred Embodiment of the Invention) The plastic used for the container material in the present invention is polyester formed from aromatic dicarboxylic acid and alkylene glycol.

Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, etc.
As alkylene glycol, ethylene glycol,
Propylene glycol, butylene gellicol and the like can be mentioned.

In the present invention, polybutylene terephthalate (hereinafter sometimes abbreviated as PBT) and polyethylene terephthalate (hereinafter sometimes abbreviated as PET) are most preferably used in terms of chemical resistance to propellants, contents, various solvents, etc. be done.

Blends with other polyesters can also be suitably used, provided that PBT or PET is contained in an amount of 50% by weight or more.

Further, in order to obtain good heat resistance, it is desirable that the crystallinity of the polyester is in the range of 20 to 40%, particularly 25 to 40%, as measured by the density method.

Further, in the present invention, glass fibers having a diameter of 12 to 15 μm and a length of 3 to 6 m +++ or more are preferably used as the fiber reinforcing agent to be blended into the polyester. In the molded state, the length is at least 0.2 m+n, especially 0.5 m.
It is desirable that it is greater than or equal to +s. That is, when the length of the glass fiber is shorter than 0.2 mm, its function as a reinforcing agent tends to deteriorate and the mechanical properties of the container tend to be unsatisfactory.

In the present invention, the glass fibers are, as already mentioned,
It is necessary that it be oriented in the height direction of the container body.

The degree of this orientation can be measured by observing the container body under a microscope as the percentage of fibers whose length direction is substantially oriented in the height direction of the body, and if this is 50% or more,
In particular, it is desirable that it be 70% or more.

If the degree of blending is less than 50%, it becomes difficult to obtain satisfactory heat and pressure resistance.

In the present invention, the above-mentioned glass fibers are blended in an amount of 5 to 30% by weight, particularly 10 to 20% by weight, based on the entire container material.

In the present invention, in addition to the above-mentioned polyester and glass fiber, other compounding agents known per se such as inorganic fillers, pigments, antioxidants, and antistatic agents may be used as necessary, as long as they do not impair the purpose of the present invention. can be blended.

In FIG. 1, which shows a side sectional view of the plastic aerosol container of the present invention, the container consists of a cylindrical body 1, a bottom 2, and a shoulder 3. Nozzle mounting opening 4
is formed.

The container of the present invention is constructed from the above-mentioned container material, but in order to give the glass fibers an orientation in the height direction of the body, the body 1 and the shoulder 3 are integrally molded by injection molding. Next, heat fusion is performed with the separately molded bottom part 2.

On the contrary, the body part 1 and the bottom part 2 may be integrally molded by injection molding, and then heat-sealed with the separately molded shoulder part 3.

Hereinafter, a case where the body part 1 and the shoulder part 3 are integrally molded by injection molding will be described as an example.

That is, in FIG.
0.10', and the glass fiber-containing resin, which is the container material mentioned above, is injected into the injection mold from this gate 10°10'.

In this case, it is necessary to use a plurality of pin gates and to arrange these pin gates to and to' symmetrically with respect to the molded container.

That is, when injection molding is performed using only one pin gate, the injected resin flow expands in a circumferential manner corresponding to the shoulder 3 and then falls in the height direction of the body. is in a random state, making it difficult to provide orientation in the height direction of the body, and for example, the above-mentioned degree of orientation cannot be increased to 50% or more.

However, if multiple pin gates are used, the circumferential spread of the injected resin flow can be minimized, so it is possible to give the blended glass fibers an orientation degree of 50% or more (in the body height direction). becomes possible.

In fact, as is clear from the examples described later, when two bin gates were used, the degree of orientation was 90%.

On the other hand, from the standpoint of imparting a degree of orientation of 50% or more (in the body height direction) to the glass fibers, the greater the number of bin gates, the better; however, if there are too many bin gates, there will be a large number of welds (junctions of resin flow). Therefore, it is undesirable.

From this point of view, the number of bin gates is preferably 2 to 4, particularly 2.

Also, during injection molding, the injection speed should be set to 50a+m/Se.
C or above, normal injection speed (40-50II1m/5
ec), and the injection nozzle exit temperature must be higher than the melting point of polyester +30°C, higher than the generally adopted temperature range (melting point +20 to 30°C).

That is, if the temperature near the exit of the injection nozzle is low or the injection speed is slow, the blended glass fibers will be broken more often, and the length of the glass fibers will become shorter than 0.2 mm, reducing the ability of the glass fibers to function as reinforcing agents. will no longer be shown.

Further, in the present invention, polyester is crystallized so that the degree of crystallinity is 25 to 40%.

This crystallization varies depending on the type of polyester used and the amount of glass fiber blended, but when the amount of glass fiber blended is 15 to 20% by weight, the injection mold is heated to 60 to 100 °C in the case of polybutylene terephthalate. Under the same conditions, in the case of polyethylene terephthalate, the injection mold is heated to 80 to 120 degrees Celsius, and the injection resin is heated to 5 to 15 seconds. Just hold it for a second.

In this way, the body portion 1 and the shoulder portion 3 are integrally molded.

The bottom portion 2 can be formed by injection molding under conditions known per se, except for crystallization.

This is done by heat-sealing these two members by means such as ultrasonic welding.

The thus obtained plastic aerosol container of the present invention is equipped with a nozzle mechanism 2o, filled with contents and a propellant, and is made into a final product as an aerosol container.

The filling of the contents is usually carried out before the bottom is melt-sealed, the nozzle is attached and sealed, and the bottom is finally melt-sealed to produce a product.

The container of the present invention described above has excellent heat and pressure resistance, and there is no need to provide a special reinforcing plate or the like on the inner wall of the body. However, when the shape of the container is oval or square, the above-mentioned It is also possible to provide a flexible reinforcing plate.

(Effects of the Invention) The aerosol container of the present invention has excellent heat and pressure resistance, and does not suffer from deformation or soft capping even when kept at a temperature of, for example, 70° C. for a long time.

Furthermore, although the container of the present invention contains glass fiber,
Since this is oriented in the height direction of the body, the vessel wall is smooth and smooth, resulting in extremely good appearance characteristics.Furthermore, shrinkage distortion is effectively suppressed, resulting in good dimensional accuracy. .

The invention is illustrated by the following example.

(Example) Example 1 Polybutylene terephthalate with a specific gravity of 1.31 was
Glass fiber-containing polybutylene terephthalate with a specific gravity of 1.41, which is a blend of 15 wt% of glass fibers of 5 μm and length of 6 m/m, was molded using a 5-ounce injection molding machine with a gate of 2 as shown in Figure 1 10.10'. Injection was carried out in a cold runner mold (mold temperature 80°C) with a set temperature of 255°C, a nozzle temperature of 265°C, an injection pressure of 600 g/cm', and an injection holding pressure time of 8 sec. In-mold cooling retention time 15s
An injection molded product with a wall thickness of 1.5 m/n+ and an internal volume of 20 cc as shown in Fig. 1 was obtained using EC.

Table 1 shows the evaluation results.

Example 2 Polyethylene terephthalate with a specific gravity of 1.34 was
Glass fiber-containing polyethylene phthalate with a specific gravity of 1.50, which is a blend of 20 wt% of glass fibers of 5μ and length 6a+/m, was molded in a 5-ounce injection molding machine at a set temperature of 260°C and a nozzle temperature in the same manner as in Example-1. 280℃, injection pressure 60
0 Kg/cm2, mold temperature 1 at injection holding time 10 seconds
Injected into a mold at 00°C, cooled in the mold for 15 seconds.
, the wall thickness is 1.511I/I11. as shown in FIG. An injection molded product with an internal volume of 20 cc was obtained.

The results are shown in Table-1.

In addition, 3 fluorocarbon gas was added to the injection molded products of Examples 1 and 2.
．． 4g and 3.4g of alcohol as contents, injection molded bottom lids (wall thickness 2m/l11) using the above materials were ultrasonically welded, an aerosol melting valve was attached, and the bicycle was heated in a 70℃ atmosphere. The container was left on a Dashboard for one day, but there were no problems such as leakage of contents or cracks in the container, and it could be used as an aerosol container.

Measurement method Crystallinity: Density gradient method Glass fiber orientation: Cut the container body into three pieces vertically and horizontally, and dye the cross section with ink. The direction of the fibers was counted by magnifying the fibers 10 times with a microscope and expressed as a percentage (average value) of the fibers in the same direction. With one direction as 1, 4
The slope of 51 is a percentage of that, and the slope of 90# is 0.

N and gas are pumped into a heat-resistant and pressure-resistant container, and elongation and cracks are observed when the set pressure is maintained for 120 seconds.

If there is no abnormality, increase the amount by 2 to 5 Kg/co+2up. (7) Ambient salinity was set at 50°C and 70°C. Judgment was made by visual appearance and tactile sensation.

The average value of the judgments made by 10 panelists on each floor is expressed by a sign. (◎-〇-low △-x) Comparative Example 1゜An injection molded product was obtained using the same material as in Example 1 using a single-gate mold as shown in Fig. 2 in the same manner as in Example 1. . The crystallinity was 32%, but the orientation rate of glass fiber was as low as 35%, and the heat-pressure resistance was 22Kg at 50℃ and 17K at 70℃.
It was a bad G, and the appearance was also a △.

Comparative Example 2 An injection molded product similar to Example 1 was obtained using only polybutylene terephthalate having a specific gravity of 1.31. Although the appearance was ○,
Heat and pressure resistance: 20kg at 50℃, 13kg at 70℃
It was kg.

Comparative Example 3 An injection molded product was obtained in the same manner as in Example 1 except that 40 wt % of the same glass fiber as in Example 1 was added to polybutylene terephthalate having a specific gravity of 1.31°.

The heat-pressure strength was good, 35 g at 50°C, and 29 g at 170°C, but the appearance was consistent with X, and the welding with the bottom lid was not stable.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an aerosol container of the present invention together with a nozzle mechanism. 1...Torso 2...Bottom 3...Shoulder 10.10'...Pin gate 20...
・Nozzle mechanism diagram 1

Claims (4)

[Claims] (1) Consisting of a cylindrical body, a bottom, and a shoulder with a nozzle attachment opening; one of the bottom and the shoulder is integrally formed with the cylindrical body, and the other of the bottom and shoulder is formed into a cylindrical The body is a plastic aerosol container that is melt-sealed, and each part of the container is made of polyester formed from aromatic dicarboxylic acid and alkylene glycol and a fiber reinforcing agent blended into the polyester, and at least the cylinder 1. A plastic aerosol container, wherein the fiber reinforcing agent is mainly oriented in the height direction of the body in the shaped body. (2) The container according to claim 1, wherein the polyester is polybutylene terephthalate or polyethylene terephthalate. (3) The aerosol container according to claim 2, wherein the polybutylene terephthalate or polyethylene terephthalate has a crystallinity of 25 to 40%. (4) The aerosol container according to claim 1, wherein the fiber reinforcing agent is contained in an amount of 5 to 30% by weight based on the total weight.