JPS6220889B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a colored polyester cosmetic bottle with a pearl-like surface luster and a flow pattern on the surface, and a method for manufacturing the same. Polyester resin is hygienic, strong, chemical resistant,
Because of their excellent fragrance retention, transparency, and surface gloss, they are being used in a wide range of applications such as cosmetics, pharmaceuticals, and food containers. However, in certain application fields, such as cosmetic containers, the appearance of the container is a key factor in its product value. There is also a demand for containers that have a unique appearance with excellent decorative properties, such as pearl-like surface luster, which is also an important element. By the way, examples of resin compositions having pearl-like surface gloss include mixed resin compositions of polycarbonate and polymethyl methacrylate, and acrylonitrile.
Mixed resin compositions of styrene copolymers and methacrylic resins are well known, and are often used because they produce molded products with strong pearl-like surface gloss, but they also have good chemical resistance, strength, and fragrance retention. Currently, it cannot be used as a molding material for cosmetic bottles because of its poor properties and limited range of use. On the other hand, a mixed resin composition of a polyester resin and a methacrylic resin could be used to make cosmetic bottles with a pearl-like surface gloss that was excellent in chemical resistance, strength, and fragrance retention. To obtain a polyester cosmetic bottle that is free from coloring spots and has excellent color stability without impairing the properties of the resin, has a pearl-like surface gloss with a strong pearly feel, and has a flowing pattern on the surface. As a result of extensive research, we mixed organic pigments and organic dye colorants with methacrylic resin to prepare colored methacrylic resin pellets, which were then mixed with a specific polyester resin within a specific composition range and molded. The present inventors have discovered that the above object can be achieved by obtaining pellets of a mixed resin composition, and then forming preforms and blow molding them, thereby achieving the present invention. That is, the gist of the present invention is that the intrinsic viscosity is
Made of colored polyester with a pearl-like surface gloss obtained by blow molding using a resin composition consisting of 60 to 99.5% by weight of a polyester resin of 0.6 or higher and 40 to 0.5% by weight of a colored methacrylic resin. The first invention of a cosmetic bottle and its inherent viscosity
60 to 99.5% by weight of a polyester resin of 0.6 or higher and 40 to 0.5% by weight of colored methacrylic resin pellets, which are extrusion-molded by adding organic pigments and/or organic dyes to methacrylic resin, are mixed and extruded. Production of a polyester cosmetic bottle having a colored pearl-like surface luster and a surface flow pattern, which comprises pelletizing a mixed resin composition, injection molding the pellets to form a preform, and then blow molding the preform. The second invention is a method. The polyester cosmetic bottle according to the present invention is composed of a mixed resin composition of a specific polyester resin and a methacrylic resin, and the methacrylic resin has been pretreated with a coloring agent such as an organic pigment or an organic dye. Since it is obtained by blow molding using a colored material, it has a pearly surface gloss with a strong pearly feel, and also has a stable color tone without color spots. The method for producing such a polyester cosmetic bottle is as described above, in which at least one colorant such as an organic pigment or an organic dye is mixed in advance with a methacrylic resin, and colored methacrylic resin pellets are formed by extrusion molding. An important requirement is to prepare mixed resin composition pellets by mixing this with a polyester resin having an intrinsic viscosity of 0.6 or more within the above composition range and extrusion molding. Thereafter, a preform was created by injection molding the mixed resin composition pellets,
This can then be obtained by blow molding. Conventional methods for coloring polymers include a method in which dyes and pigments are directly dry-blended to polymer pellets, and a so-called masterbatch method in which dyes and pigments are added at high concentrations and dry-blended colored pellets and uncolored polymer. A colored preform was molded by injection molding from a mixed resin composition of a polyester resin and a methacrylic resin, and then a hollow container like a bottle was produced by stretch blowing, etc. As a result, pearl-like surface gloss and surface Although it is possible to obtain a container that is colored with a flowing pattern and has an elegant feel, the above-mentioned mixed resin compositions of polycarbonate and polymethyl methacrylate or mixed resin compositions of acrylonitrile-styrene copolymer and methacrylic resin can be used. It is difficult to produce a container with a stable appearance because it is difficult to obtain a strong pearly appearance, and it also suffers from color spots and lacks stability in color tone. However, the present invention solves the disadvantages of the conventional method by mixing pellets previously colored only with methacrylic resin as described above with polyester resin within a specific composition range and extrusion molding to obtain pellets with a mixed resin composition. It has the great feature of being able to The polyester resin used in the present invention is one in which 60 mol% or more of the repeating units that constitute it consist of ethylene terephthalate, and the copolymerized components include isophthalic acid, adipic acid, sebacic acid, and P-β-oxyethoxybenzoic acid. , dicarboxylic acid components such as diphenyl ether-4,4'-dicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, etc. or their alkyl ester derivatives, glycols such as propylene glycol, butanediol, cyclohexanedimethanol, etc. type is used. Polyester resins can be produced by any of the following methods: polycondensation via transesterification, direct esterification and polycondensation, or solid phase polymerization of the polymers obtained by these methods. The resulting polymer can be used, but its intrinsic viscosity [η] is
Must be 0.6 or higher, preferably
It ranges from 0.65 to 1.4. It is preferable to use a polyester resin with a large [η] because it tends to have good pearl-like surface gloss and luster. If [η] is less than 0.6, it is not preferable because the mechanical strength of the final bottle will be significantly lowered, and the surface of the body will lose its luster, impairing its beauty. On the other hand, if [η] exceeds, for example, 1.4, the molding processability becomes poor, which is not preferable. Note that [η] is phenol/
25 in tetrachloroethane = 50/50 (weight ratio) solution
This value was determined from the solution viscosity measured at °C. The methacrylic resin in the present invention is a homopolymer of methyl methacrylate, a copolymer of 50 mol% or more of methyl methacrylate and another vinyl monomer that can be copolymerized with it, or a mixture of these polymers. . Other vinyl monomers that can be copolymerized with methyl methacrylate include acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, butyl acrylate, acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, etc. It will be done. In the present invention, it is preferable to use a homopolymer of methyl methacrylate or a copolymer with methyl acrylate or ethyl acrylate because a bottle having particularly excellent pearl-like surface gloss can be obtained. As the colorant used to color the methacrylic resin, known organic pigments or organic dyes may be used alone or in combination. Specific examples include soluble azo pigments such as Lake Red C and Prilliant Carmine 6B, phthalocyanine pigments such as Phthalocyanine Blue, insoluble azo pigments such as Diazo Yellow and Fast Yellow, isoindoline pigments, quinacridone pigments, and perylene pigments. Examples include organic pigments such as pigments and disperse dyes used for dyeing polyester fibers. These colorants are added in desired amounts within a range that does not impair the properties of the methacrylic resin. In this case, it is more preferable to use an appropriate amount of a dispersion aid. In this way, the colorant and the dispersion aid are added to the methacrylic resin, mixed, and then extruded into pellets. The higher the transparency of the colored methacrylic resin pellets obtained, the stronger the pearl-like surface gloss of the final bottle will appear, so it is desirable that the pellets have a high transparency. As a relative evaluation standard for the strength of the pearly surface gloss of this pellet, for example, a flat plate with a thickness of 1 mm is formed from the pellet, and the light transmittance of the plate is measured by a method according to JISK6717, and the value of the final bottle is measured. Comparing the strength of the pearl-like surface gloss, the light transmittance is 50.
% or more, a strong pearl-like surface gloss appears, and when the light transmittance is in the range of 10 to 50%, a moderate pearl-like surface gloss appears. Moreover, when the light transmittance is in the range of 1 to 10%, a weak pearl-like surface luster is obtained. Furthermore, if the light transmittance is 1% or less, a very weak pearl-like surface gloss will result. In carrying out the present invention, a suitable method for mixing the polyester resin and the colored methacrylic resin pellets and forming them into pellets is a method in which the respective resins are mixed in a blender and then pelletized using a conventional melt extruder. The polyester cosmetic bottle of the present invention needs to have a composition of 60 to 99.5% by weight of the above-mentioned polyester resin and 40 to 0.5% by weight of colored methacrylic resin. If the content of the colored methacrylic resin is less than 0.5% by weight, the entire bottle will have a strong sense of transparency, and the pearly surface gloss will almost disappear. On the other hand, the content of the methacrylic resin is 40% by weight.
Exceeding this is not preferable because although the whiteness of the bottle increases, the pearly feel becomes weaker. Furthermore, lotion,
It is not preferable to fill hair styling products, fragrances, etc. for a long period of time because cracks may occur, the drop strength during filling may be significantly reduced, and the fragrance retention characteristic of polyester resins may deteriorate. The colored bottles of the present invention with a strong pearl-like surface gloss and a strong surface flow pattern cannot be obtained by so-called direct blow molding, in which bottles are manufactured directly from extrusion molding, but are made by first forming a preform by injection molding. Next, the preform is transferred to a blow mold and molded using the injection blow molding method, or by injection molding, the preform is once molded, cooled, taken out from the mold, reheated to within the stretching temperature range, and then biaxially stretched and blown. It can only be obtained by the so-called biaxial stretch blow molding method. In the present invention, when manufacturing preforms by injection molding, it is important to keep the mold temperature at 50°C.
In addition, the injection speed of the resin into the mold, that is, the injection speed should be increased. If the mold temperature during preform molding exceeds 50℃, it will take a long time for the preform to cool and solidify, resulting in a longer molding cycle.Moreover, if molded under such conditions, the preform will crystallize and lose its pearly surface luster. Therefore, it is undesirable. On the other hand, injection speed has a large effect on the pearly surface gloss and surface flow pattern.
As the injection speed increases, the surface flow pattern becomes more pronounced. However, if the injection speed is extremely high, the luster around the gate will disappear, stains will appear, and the flow pattern on the top surface will lose its elegance, and even if it is blow-molded, a desirable cosmetic bottle cannot be obtained. On the other hand, if the injection speed is decreased, the surface flow pattern becomes weaker and the pearly surface gloss decreases, so a moderate injection speed is required. The wall thickness of the preform can be changed arbitrarily depending on the shape of the intended cosmetic bottle and conditions during blow molding, but from the viewpoint of moldability, it is desirable to be in the range of 1 to 12 mm. In the case of a polyethylene terephthalate homopolymer, it is preferably in the range of 1 to 5 mm, and in the case of a copolymer, it is preferably in the range of 1 to 12 mm. The cosmetic bottle of the present invention is manufactured by using the above-mentioned in-die extension blow molding method or the biaxial stretch blow molding method, but it is better to use the preform when it is blow molded by the biaxial stretch blow molding method. Has superior pearl-like surface gloss. That is, by biaxially stretch blow molding the preform at a stretching temperature of 80 to 160°C and a total stretching ratio of 1.3 to 20, it is possible to not only improve the appearance of the resulting bottle but also further improve its mechanical strength. Therefore, it is particularly preferable. Hereinafter, a manufacturing method example of the present invention using the above-mentioned biaxial stretch blow molding method will be specifically explained. The stretching temperature is defined by the outer surface temperature of the preform immediately before biaxial stretch blow molding, and it is necessary that the inner surface temperature of the preform also fall within the above temperature range. If blow molding is performed at a temperature below 80°C, stretching will occur partially, resulting in uneven wall thickness and a molded product with poor mold reproducibility. Further, blow molding at a temperature exceeding 160° C. is not preferred because it is difficult to achieve sufficient orientation and the resulting molded product has extremely low mechanical strength such as drop strength. In order to maintain the preform within the above stretching temperature range, the preform in a high temperature state obtained by injection molding may be left to cool, or the preform in this high temperature state may be cooled to about room temperature and then heated using a far infrared heater or the like. A method may be used as appropriate, such as a method of heating uniformly while rotating. The above-mentioned total stretching ratio is defined as follows. That is, R ₁ is the ratio of the stretch-oriented longitudinal size of the biaxially stretch blow-molded bottle to the substantially unoriented longitudinal size of the preform corresponding to this longitudinal direction; If the ratio of the lateral size of the stretched bottle to the substantially unoriented lateral size of the preform corresponding to this lateral direction is R ₂ , then the total stretching ratio is expressed as R ₁ × R ₂ It is something that can be done. The cosmetic bottles obtained by the method of the present invention have extremely excellent appearance, chemical resistance, fragrance retention, mechanical strength, etc., and are suitable for basic lotion bottles, men's cosmetic bottles, cream containers, cologne containers, and shampoo containers. It is suitable for various cosmetic bottles such as bottles and rinse bottles. The present invention will be specifically explained below using Examples. Example 1 An acrylic resin molding material manufactured by Mitsubishi Rayon Co., Ltd. A mixture of Acrypet VH, 0.1% by weight of RAKERED C and 0.005% by weight of a nonionic surfactant, L/D = 24, supply zone 11D,
Compression zone 6D, metal ring zone 7D, pitch
The mixture was fed to a 40 mmφ extruder manufactured by Toshiba Machine Co., Ltd. equipped with a 1D screw with a compression ratio of 2.5, and extrusion molded to obtain red pellets. This red pellet was heated at 80℃ for 20 minutes.
Polyethylene terephthalate with [η] of 1.1 and the first
The mixtures were mixed in the proportions shown in Table Test Nos. 1 to 5 and Comparative Examples 1 to 2, and fed to the 40 mmφ extruder, and extrusion molded to obtain colored mixed resin composition pellets. Next, the obtained mixed resin composition pellets were vacuum dried at 150°C for 5 hours, and then L/D = 17, supply zone 8.5D, compression zone 5.3D, metering zone 3.2D, pitch.
The weight is 35g, the average wall thickness of the body is 3mm, the outer diameter of the screw part is 28mm, and the average diameter of the body is 26mm using a Meiki Seisakusho SJ-40C injection molding machine equipped with a screw of 0.9D and a compression ratio of 1.8.
A preform with a length of 135 mm was molded using a single direct gate mold. The molding conditions were as follows. Cylinder temperature is C ₁ 270℃, C ₂ 280
℃, C ₃ 290℃, nozzle 290℃, primary injection pressure (gauge pressure) 30Kg/cm ² , secondary injection pressure (gauge pressure) 20Kg/cm 2
cm ² , injection speed 20 g/s, molding cycle 35 seconds,
The mold temperature was 10°C. The obtained preform was set in a biaxial stretch blow molding machine, heated until the temperature of the preform reached 105℃, and then 20Kg/
Blow with a blow pressure of cm ² 54mmφ, height 170
A cylindrical pink colored cosmetic bottle of mm was molded. Pearl-like surface gloss of the resulting cosmetic bottle,
The surface flow pattern, the appearance after being left at 40°C for one month after being filled with ethanol, and the drop test were evaluated. The results are shown in Table 1. In Table 1, the evaluation display of pearl-like surface gloss, surface flow pattern, and drop test is as follows (these display methods are common to the following Examples and Comparative Examples). Pearl-like surface gloss ◎: Extremely strong pearl-like surface gloss ○: Fairly strong pearl-like surface gloss △: Weak pearl-like surface gloss ×: No pearl-like surface gloss, surface flow pattern ◎: Very strong surface flow pattern 〇: Very strong surface flow pattern △: Weak surface flow pattern ×: Drop test with no surface flow pattern Fill a bottle with ethanol, leave it at 40℃ for 1 month, then extract the ethanol, then fill it with 0℃ water for 1m
The number of times a bottle was dropped from a height of 200 meters to a concrete floor with its bottom facing up was determined to determine the number of times the bottle would break.

[Table] The above-mentioned uncolored acrylic PET VH as a comparative example
Polyethylene terephthalate with [η] of 1.1 was dried, mixed and extruded in the same manner as in Test Nos. 4 and 5 to obtain mixed resin composition pellets. Next, [η] including rake lead C is 1.1
A masterbatch of polyethylene terephthalate was diluted 10 times and added to the same amount of Lake Red C as in Test Nos. 4 and 5, and after sufficiently drying, injection molding was performed in the same manner as above to obtain a pink preform.
Then, biaxial stretching blowing was performed in the same manner to obtain a pink bottle. The evaluation results of the obtained bottles are shown in Table 2.

[Table] Example 2 Phthalocyanine blue for acrylic resin molding material Acrypet MD manufactured by Mitsubishi Rayon Co., Ltd.
0.15% by weight and 0.005% by weight of a nonionic surfactant were added and mixed well, and the mixture was fed to the 40 mmφ extruder manufactured by Toshiba Machine Co., Ltd. used in Example 1 and extruded to obtain greenish-blue pellets. The colored pellets were dried under vacuum at 80°C for 2 hours, and then at 150°C for 5 hours.
Mix at a ratio of MD/polyethylene terephthalate = 13/87 (weight% ratio), and
The mixture was fed into an extruder and extrusion-molded to obtain colored mixed resin composition pellets having a shape of 3 mmφ x 3 mm.
Next, the obtained mixed resin composition pellets were heated at 150°C.
After vacuum drying for 5 hours, injection molding was performed using the injection molding machine used in Example 1 under the same conditions to obtain a similar preform. Next, biaxial stretching blowing was performed in the same manner as in Example 1 to obtain a pale blue-green cosmetic bottle of the same shape. Similar evaluations were performed on the obtained cosmetic bottles. The results are shown in Table 3.

【table】

Claims (1)

[Claims] 1. Polyester resin 60 having an intrinsic viscosity of 0.6 or more
~99.5% by weight and colored methacrylic resin 40~
A polyester cosmetic bottle having a colored pearl-like surface gloss and a surface flow pattern obtained by blow molding a resin composition comprising 0.5% by weight. 2 Polyester resin 60 with an intrinsic viscosity of 0.6 or more
~99.5% by weight and 40-0.5% by weight of colored methacrylic resin pellets extruded from methacrylic resin with organic pigments and/or organic dyes.
A colored pearl-like surface gloss and surface flow pattern characterized by mixing and extrusion molding to form a mixed resin composition pellet, injection molding the pellet to form a preform, and then blow molding the preform. A method for manufacturing a polyester cosmetic bottle having the following.