JPS5820635A - Plastic vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plastic container, and more particularly to a plastic container that has a high-grade carnivorous appearance, excellent heat shrinkage resistance, and 1a mechanical strength.

Plastic containers, e.g. PVC.

Containers made of thermoplastic resins such as polycarbonate, polystyrene, poly(7-critonitrile), polyester, and polyolefin resins are widely used as containers for foods, cosmetics, cosmetics, and pharmaceuticals. In particular, polyethylene terephthalate (represented by polyester resin containers) has transparency, gas permeability resistance, safety, and mechanical properties. In recent years, its use has been expanded dramatically as containers for foods, medicines, cosmetics, alcoholic beverages, etc.

Although most of such plastic containers have excellent transparency, they are unsatisfactory in terms of the high-class appearance of the container.

In general, the ways to make the appearance of a container more luxurious are as follows:
For example, there are methods to give the outer surface of the container a so-called frosted glass appearance by adding fine irregularities as seen on glass containers, or methods to add many striped patterns to the outer surface. As a method for imparting a similar appearance, a method is generally used in which a blow molding mold is processed to produce a similar pattern. However, in the transfer method using a mold, the pattern is transferred only to the outer surface of the container, resulting in a lack of depth in terms of appearance (4), and the presence of air between the mold surface and the outer surface of the container during molding. The pattern of the mold may not be fully transferred to the container because the mold cannot be completely removed, the container may stick to the surface of the mold, which may cause molding problems, and the finely engraved parts of the mold may contain low polymers, etc. Disadvantages include the accumulation of solids that are transferred to the outer surface of the container, resulting in visual defects.

In addition, as a method for manufacturing a 7P stay-like container using polyester resin, there is a method in which a polyester container or a bottomed parison, which is an intermediate hollow material, is subjected to Zanodzlast processing to roughen its surface, or a method in which the bottomed parison, which is an intermediate hollow material, is roughened. Methods have been proposed in which the parison is crystallized by solvent treatment and then biaxially oriented, but these intermediate or post-processing involve chemical or physical changes during or after container manufacturing. Therefore, productivity is poor (and it is difficult to always obtain containers for floss buoys under constant conditions).

Alternatively, a parison with a bottom, which is an intermediate material, is crystallized by heating and then blow molded, or a parison with a bottom is crystallized by slow cooling during injection molding, and then blow molded. However, it is difficult to check the degree of crystallization of the bottomed parison, and if the parison is too crystallized throughout, the blow mold It is difficult to stretch into the shape of a street,
It has the disadvantage that complete shaping is not possible.

Furthermore, attempts have been made to obtain frosty-like containers by blow molding by adding inorganic inert particles such as kuruk or clay into polyester resin, but the containers obtained by blow molding are The thick part of the bottomed parison may cause crystallization because the inert particles added from the outside act as a so-called crystallization nucleating agent, which promotes the crystallization of polyester. , during injection molding, if the injection part becomes significantly white, or if the injection port becomes the bottom of the container, the whitened part will significantly reduce the drop impact strength of the container. Satisfactory 70-stay containers have not been obtained with the addition of inert particles.

The present inventor has discovered a method to obtain a container that has improved heat shrinkage resistance and mechanical strength and has an excellent frosty appearance compared to containers obtained by conventional methods. By stretch-molding a thermoplastic resin containing particles, especially glass spheres, in a specific proportion, it has a high-grade appearance, heat shrinkage resistance,
The inventors have discovered that it is possible to obtain a plastic container with excellent mechanical strength such as buckling strength, pressure resistant shape, and deformation resistance under reduced pressure, and have arrived at the present invention.

That is, the present invention is a thermoplastic resin container having a stretched portion in at least one direction. This is a plastic container characterized by containing 01 to 30% by weight of particles.

Thermoplastic resin melting and blow molding referred to in the present invention.

It is a thermoplastic resin that can be molded into containers by a molding method that involves vacuum forming, air pressure forming and stretching. 'Preferable thermoplastic resins are shown in Table 1. Among these, those having a light transparency of 70 inches or more are more preferable because they form a good frosty appearance, and polyester resins are particularly preferable because the effects of the present invention are particularly exhibited.

Note) 1) A: Good transparency, B: Slightly cloudy C:
Translucent, D: Opaque z) Measured by A8TM D-1003 Particularly preferred among the thermoplastic resins mentioned above are polyester resins obtained by the reaction of terephthalic acid or its lower alkyl ester with ethylene glycol. The main target is polyethylene terephthalate, but -all of 711 minutes of terephthalate (usually 20 mole or less) is used as inphthalic acid.

Naphthalene dicarboxylic acid, dipheni! dicarboxylic acid,
Aromatic dicarphonic acids such as diphenoxyekundicalphone I1M, diphenyl ether dicarpone N, and siphenylsulfone dicarphone 11%; alicyclic dicarphonic acids such as hexahyp-terephthalic acid, hexahyphthalate, etc.; adipine; Brewing 1. with one or more of the other difunctional hydroxycarphonic acids such as cepatine, azelaic acid, etc.; p-β-hydroxyethoxybenzoic acid-ε-oxycabonic acid, /
Or, a part of the ethylene glycol component (usually 20 mol or less) can be added to, for example, triethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, 1,1-cyclohexane dimethylol. , 1,4-cyclo-,xanedimethylol, 2,2-his(4'-β-human p-oxyethoxyphenyl)furopane, bis(4'-β-hydroxyethyl)
It may also be substituted and copolymerized with one or more polyfunctional compounds such as other glycols such as toxyphenyl sulfonic acid and functional derivatives thereof.

Among such polyester resins, a homopolymer of polyethylene terephthalate is most preferred, and the polyethylene terephthalate preferably has an intrinsic viscosity of 0.5 or more, and more preferably has an intrinsic viscosity of 0.60 or more. Furthermore, the softening point of polyethylene prephthalate is 220°C to 27°C.
0°C is preferred, particularly 250°C to 265°C. It is desirable that other polyester resins also have physical properties similar to those described above. The polyester resin may also be produced by any method known to those of ordinary skill in the art.

The inorganic particles used in the present invention are particles having an average particle diameter of 41 mm smaller than the wall thickness of the stretched portion of the container.

. If the average particle size is larger than the wall thickness, the thickness of the thermoplastic resin portion may become too thin and KMIIi may occur during elongation. The preferred particle size range is 1/2 or less of the wall thickness of the extended portion. There is no particular restriction on the lower limit of the average particle size, but if it becomes too fine, the full-stay appearance that is a feature of the present invention will be lost, and the appearance will become a mere cloudy one. It is desirable that there be.

The shape of the particles may be spherical, cylindrical, or irregularly shaped, and the particle size of each shape is defined by the following formula.

Particle size - (, LA + Lm) / 2 where LA,
LB are the maximum and minimum lengths of the grains in the projection plane at various angles.

Further, in the present invention, the LA/LB ratio is preferably less than 3, and the most preferable shape is spherical. A spherical shape is preferable because the container has a uniform appearance.

If LA/LB is larger than 3, the vAK mold traceability for forming the container is not good, the elongation is small, and the appearance is different from the flexible shape of the present invention. This is not desirable or undesirable because it gives a bad appearance.

The material of the inorganic particles used in the present invention may be any material that is thermally stable at the melting temperature of the thermoplastic resin, and transparent materials are preferred as they exhibit a high-grade appearance when the particle size becomes large. , for example crow particles are particularly preferred.

The proportion of inorganic particles, particularly glass particles, contained in the thermoplastic resin is in the range of 01 to 30%. This ratio is O
If the amount is less than 1-1, the high-grade appearance that is a feature of the present invention will be lacking, and if it is more than 301 L, it will be difficult to form a container by stretching.

The preferred blending ratio of the glass particles varies depending on the container molding method, stretching ratio, stretching temperature, and other molding conditions, but for example, polyethylene terephthalate resin, 02 to 10 m1i% when molded by the axial stretch blow molding method, o to things
, s to 5% by weight is preferable because the container has a good appearance and the molding operation is easier.

Examples of the plastic container of the present invention include a bottle.

An example is a container obtained by a molding method that involves stretching. By stretching during the molding process, the present invention! l! A full-stay appearance, which is one of the f-characters, develops, and such an appearance cannot be obtained, for example, if the container is simply formed by injection molding.

For example, in the case of bottles, methods for obtaining containers having the features of the present invention include conventionally known injection blow molding methods 1, extrusion blow molding methods,
A biaxially oriented blow molding regime is advantageously used. In injection blow molding, an expandable geometric shape is directly injection molded to form a closed-ended parison, which is then transferred into a bottle mold and blow expanded. At this time, when injection molding the parison, it is preferable to cool the core mold and the injection mold with a water-cooled or air-cooled refrigerant. In addition, when molding a container by extrusion blow molding, first extrude heated and melted thermoplastic resin into a pipe shape, and then cut the pipe-shaped extrudate into a desired length and cut out the bottom to create a bottomed container. A parison is made, the shell parison is transferred to a mold that has the shape of a desired container, and a pressure-fluid such as compressed air is blown into the parison to expand it to the shape of the container.

In addition, when molding a container by biaxially oriented blow molding using thermoplastic oil, the thermoplastic resin is first melted by heating to a temperature above the melting point using an injection molding machine, and then injected into a preform mold and cooled. A parison with a bottom is formed, and then the core parison is preheated to a temperature within the range of a thermoplastic +'l resin drawing section, and after the desired container shape is transferred into a mold, it is drawn using a drawing rond. While stretching in the axial direction, compressed fluid or compressed air is blown into the container to expand it to the shape of the container. Containers obtained by biaxially oriented blow molding have excellent mechanical strength and heat shrinkage resistance. In addition, a polyester container having even better heat shrinkage resistance can be obtained.

When the bottomed parison is stretched or expanded by blowing, the stretching ratio of the body of the bottle is at least 12 times, preferably at least 2 times, in terms of area ratio. Further, as a method for obtaining containers such as pots, for example, methods such as pressure forming and vacuum forming are applied.

When producing a container containing inorganic particles by the above-mentioned blow molding, pressure forming, vacuum forming, etc., the container may be made of a single layer of thermoplastic resin layer containing inorganic particles, or depending on the use, - It may also have a mono- or multi-structure with other resins.

When molding the above container, dyes, a-materials, ultraviolet absorbers,
Glass fibers, stabilizers, etc. may be added within a range that does not impair the purpose of the present invention.

In the present invention, any method can be selected as the method for adding the inorganic particles. For example, a method in which the heat t=J is added when polymerizing plastic resin, a method in which a master pellet containing a high concentration of inorganic particles is separately manufactured and blended with pellets without additives during molding, or a method in which the additive is not added. There are methods such as directly molding inorganic particles by punching them into pellets, but in order to tightly disperse inorganic particles in thermo-movable sesame, there is a method of adding thermoplastic resin to the polymerization vein, Alternatively, a method using a master pellet is preferred. If the glass fibers are poorly dispersed in the resin, not only will the commercial value of the hollow container be significantly impaired, but the effect of improving heat shrinkage resistance and q-mechanical strength will not be exhibited.

The frosty-like container produced by the method of the present invention only needs to contain inorganic particles in the thermoplastic resin, and does not require any post-processing such as sandblasting, and is economically superior. In addition, it has the advantage of being able to be manufactured under constant conditions and having excellent reproducibility. In addition, the addition of the inorganic particles does not impair the original excellent properties of the thermoplastic resin (it maintains excellent gas permeation resistance and mechanical strength). Since the bottomed parison has excellent slip properties, the productivity during manufacturing and filling containers is greatly improved.

The plastic container thus obtained has excellent heat shrinkage resistance and mechanical strength, and is useful as a variety of industrial containers, and also has a decorative appearance. 4. Useful as a beverage container. .

The present invention will be described below with reference to Examples, but the present invention is not limited to the following Examples unless it departs from the gist thereof. The methods for measuring the main characteristics measured in the examples are shown below.

After filling a bottle with hot water having a hot water shrinkage rate of 8.0°C, the bottle was tightly stoppered and left to stand. After 24 hours, the bottle was opened and the internal volume of the bottle was measured. The shrinkage rate was determined using Equation 1.

However, ■ o: Bottle volume V before hot water filling; Bottle volume buckling strength after hot water filling treatment; Toyo Sokki TgNsn, oN/UTM -1
11-so.

5 times vertically on the empty bottle. Apply the load at a head speed of 1/min. The load at which the bottle deforms was determined.

Pressure resistance strength: 10k by filling a bottle with water and using a water pressure machine
)/cdG/min, and the pressure at which the bottle burst was determined.

Light transmittance and haze: Measured using an integrating sphere type light transmittance 4 measuring device (measured at a thickness of 0.3 m/'m)J
According to ISK-6714. When this light transmittance is 2 degrees or more, a full-stay tone appears.

Examples 1 to 4 and Comparative Example 1 Glass pea f! having an average particle size shown in Table 2 below.
-2, using polyethylene terephthalate pellets with an intrinsic viscosity of 0.74, and using an injection molding machine with a cylinder temperature of 280°C, the weight was 499. length 176
m / m + wall thickness 3.5 + a / rough cylindrical ring-bottomed parison was molded.

At this time, the preform mold was cooled to 10° C. with cold water. Next, the patterned paper was reheated to an internal temperature of 90 to 105°C, and then biaxially stretched and blown to a height of 270°C.
A bottle was obtained having an internal volume II of m/m + body diameter of 80 to 90@/m and an average body wall thickness of 0.35 cm/den. Table 2 shows the shrinkage rate, buckling strength and pressure resistance of the obtained bottle when filled with 80°C hot water.

The glass beads were added using master pellets (dispersed in polyethylene terephthalate having an intrinsic viscosity of 070) containing 20% by weight of glass beads.

Examples 5 to 9 and Comparative Example 2! -2If (using glass beads as shown) p- Bottles with an internal volume of 1/2 were obtained in the same manner as in Examples 1 to 4, except that the mold temperature was 95 to 105°C. The measurement results of the obtained bottles are shown in Table 2.

In the case of Examples 8 and 9, a green coloring agent of phthalcyanine blue and chimephthalone was contained in the polyethylene terephthalate in high quality as a coloring agent, and the mixture was added by pressurizing a master pellet. As a result of using a colorant in combination with the present invention, the sense of luxury is further reduced.

From Table 2, it can be seen that glass beads 05 weight Q6 D) The container made of polyester containing horn beads contains 1. f [Hot water shrinkage rate and buckling 9 compared to ugly containers! It can be seen that the mechanical strength such as mechanical strength and pressure resistance strength was immediately 1, indicating that the improvement effect of the present invention is remarkable. In addition, the appearance of the obtained containers was of a deep floss 7-E tone in all cases except for the comparative example.

Example 10 Pellets of polyethylene terephthalate copolymerized with 12 neopentylene glyfur were used as the glycol component with an intrinsic viscosity of 075, the surface of which was sprinkled with glass peas 05-II with an average particle size of 80μ. Then, using an injection boo molding machine (injection blow molding machine), the cylinder temperature was 280°C, the injection mold temperature was 40°C, the injection core temperature was 60°C, the blowing mold temperature was 30°C, and the blow pressure was 9°C.
Injection blow molding was carried out under the conditions of CRLA and the outer diameter of the body was 34.
A bottle with a bottle height of s s vn/m r and a body wall thickness of 0.6 to 0.7 yr/@ was obtained. The resulting bottle had a transverse stretching ratio of about 2 times.

The resulting bottle had a light transmittance of 70% in the body (portion with a wall thickness of 0.61 n/y), and was a full-stay-like bottle with a unique decorative appearance.

Comparative Example 3 Injection blowing was carried out in the same manner as in Example 8 except that glass beads were not added. Although the obtained container had good transparency, it had an appearance that lacked a luxurious appearance. In addition, continuous operation was difficult due to poor chipping of the chips.

Example 11 Glass beads with an average particle size of 150 μm were mixed with polycarbonate resin (manufactured by Teijin Kasei ■/Kunrai)
L-1225) was used, and using injection blow molding @ (injection blow molding machine), the cylinder f' temperature was 280 to 300°C, and the injection mold temperature was 120°C.
Injection blow molding was carried out under the following conditions: injection core temperature 190℃, blow mold temperature 150℃, blow pressure 9kg/c-dG, body outer diameter 3'm/m *bottle height 88cm/m + A bottle with a body wall pressure of 06 to 0.7 m/m was obtained. The resulting f+ flask had a transverse stretching ratio of about 2 times.

The resulting bottle had a light transmittance of 70 cm in the body (portion with an internal thickness of 06 ml/m), and was a frosty-like bottle with a decorative external appearance.

2

Claims (1)

[Claims] 1. A thermoplastic resin container having a portion stretched in at least one direction, wherein the thermoplastic resin has an average particle size smaller than the wall thickness of the stretched portion of the container. A plastic container containing 01 to 30 tqb of inorganic particles. 2. The plastic container according to claim 1, wherein the inorganic particles are glass spheres. 3. The plastic container according to claim 1, wherein the thermoplastic resin is a thermoplastic resin having transparency with a light transmittance of 70% or more. 4. The plastic container according to claim 1 or 3'X)4, wherein the thermoplastic resin is a polyester resin containing ethylene terephthalate as a main component;