JPH0784528B2 - Plastic molded body having transparent portion and opaque portion - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic molding having a transparent portion and an opaque portion.

[0002]

2. Description of the Related Art Conventionally, as a method of making a part of a molded article transparent, for example, in a bottle-shaped container, there is a method utilizing a multi-layer blow molding method. That is, in the multi-layer extrusion blow molding method, when molding a bottle with a two-layer structure in which an opaque resin is placed in the outer layer and a transparent resin is placed in the inner layer, the outer layer is designed by devising the shape of the mandrel of the multi-layer head part of the molding machine. There is a method of blocking a part of the cylindrical flow of resin and making a part where the outer layer resin of the two-layer parison extruded from the die does not exist in a slit shape, and this slit part is a transparent resin of the inner layer. There is proposed a container provided with a transparent portion, which is so-called a liquid level window, which is formed only by itself.

As another method, in the multi-layer extrusion blow molding method, a parison having a transparent portion and an opaque portion at the top and bottom is obtained by blocking the flow of the opaque outer layer resin from the extruder in a timely manner. It is conceivable to obtain a bottle that is molded and gradations up and down, or a bottle that is transparent only at the bottom or top. In addition to this, it is possible to obtain a bottle in which the upper part or the lower part is partially transparent by adjusting the injection timing of the inner and outer layer resin and the intermediate layer resin by using the multi-layer injection blow molding method.

Also, in a sheet-shaped or film-shaped molded product, it is possible to form a slit-shaped transparent portion by using a multilayer die head.

[0005]

However, the above-mentioned technique for obtaining a plastic molding having a transparent portion and an opaque portion requires a very complicated molding machine,
It also requires a very complicated molding technique. Furthermore, the pattern of the transparent part of the obtained molded body is limited. That is, the transparent part can be molded in a rough range such as a vertical slit shape or only the upper part or the lower part of the molded body, and the transparent part can be finely controlled to obtain a desired design. It was impossible to get. For example, it has been said that it is impossible to make a picture or a character part transparent.

Therefore, a first object of the present invention is to provide a technique capable of easily providing a plastic molding having a transparent portion and an opaque portion. The second aspect of the present invention
The purpose of is to provide a technique capable of making the pattern of the transparent portion as desired.

[0007]

The above-mentioned object of the present invention is as follows.
The thermoplastic resin A having transparency and the thermoplastic resin B having transparency are used so that the difference in the refractive index in the non-oriented state at 0 ° C. is about 0.05 or less.
The thermoplastic resin B constitutes a disperse phase, and the thermoplastic resin A matrix phase has a substantial difference in the degree of molecular orientation depending on the location. This is achieved by a plastic molding having a characteristic transparent part and an opaque part.

It is more preferable that the difference in the refractive index in the non-oriented state at 25 ° C. is about 0.04 or less.
Here, “transparent” and “opaque” do not mean completely transparent or completely opaque, but are relative ones. Therefore, even if it is the same semi-transparency, if the other part is more opaque, that part can be regarded as transparent, and conversely if the other part is more transparent, that part is opaque. Consider.

The present invention will be described in detail below. As a result of earnest push by the present inventors on a plastic molded article having a transparent portion and an opaque portion, for example, in the stage before stretch molding, the thermoplastic resin A
As shown in FIG. 1, the resin composition of
Although it has a sea-island structure in which the dispersed phase 2 floats in the matrix phase 1, at the stage after stretch molding, as shown in FIG. 2, the system is stretched uniaxially or biaxially by stretch molding. At this time, although the matrix phase 1 is stretched, molecular orientation occurs, but the dispersed phases 2 are independent of each other, and since tensile force is not applied, the molecular orientation does not substantially occur, and the matrix phase 1 is refracted. It has been found that the system becomes opaque because only the rate changes.

As a result of further research, it was found that, even when stretch molding was performed, it was possible to prevent molecular orientation in the matrix phase 1 at this time.
That is, for example, it is found that when the temperature is controlled to be 125 ° C. or higher and stretch-molding is performed, the matrix phase 1 becomes substantially free of molecular orientation (no molecular orientation or little molecular orientation). Then, it has been found that there is substantially no change in the refractive index between the matrix phase 1 and the dispersed phase 2 and the transparency is not impaired.

The present invention has been achieved based on such knowledge. Thermoplastic resin A in the present invention
It is preferable that the main repeating unit is a thermoplastic polyester resin composed of ethylene terephthalate. For example, polyethylene terephthalate, copolymerized polyester of terephthalic acid, isophthalic acid and ethylene glycol, terephthalic acid and ethylene glycol 1,
Examples thereof include copolymerized polyesters with 4-cyclohexanedimethanol and copolymerized polyesters with terephthalic acid, isophthalic acid, ethylene glycol and propylene glycol. These may contain a small amount of other copolymerization components as described below. For example, as the dicarboxylic acid component, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid, p-oxybenzoic acid,
A small amount of diethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, neopentyl glycol, polyethylene glycol, polytetramethylene glycol or the like may be copolymerized as a glycol component.

The intrinsic viscosity of the thermoplastic polyester resin is preferably in the range of 0.5 to 1.4. That is, if the intrinsic viscosity is less than 0.5, which is too low, the impact resistance of the molded article tends to be impaired, and conversely, if it exceeds 1.4 and is too high, the moldability tends to be extremely poor. Because there was. The thermoplastic resin B in the present invention is preferably selected from the group of styrene resins and polycarbonate resins. Examples of styrene resins include polystyrene, impact-resistant polystyrene, and poly-
Examples thereof include styrene resins such as α-methylstyrene, poly-o-methylstyrene, poly-o-chlorostyrene, and poly-o-methoxystyrene, which do not impair transparency and have a refractive index referred to in the present invention. Other monomers may be copolymerized within a range not departing from the range.
For example, methyl (meth) acrylate, ethyl (meth)
(Meth) such as acrylate and (meth) acrylonitrile
Acrylic monomers and the like may be used. Polycarbonate resins include poly (oxycarbonyloxybis (1,4- (3,5-dichlorophenylene)),
Poly (oxycarbonyloxy-1,4-phenylene butylidene-1,4-phenylene), poly (oxycarbonyloxy-1,4-phenylene cyclohexylidene-
1,4-phenylene), poly (oxycarbonyloxy-1,4-phenylene-1,3-dimethyl-butylidene-1,4-phenylene), poly (oxycarbonyloxy-1,4-phenylenediphenyl-methylene-1) , 4
-Phenylene), poly (oxycarbonyloxy-1,
4-phenyleneethylidene-1,4-phenylene), poly (oxycarbonyloxy-1,4-phenyleneisobutylidene-1,4-phenylene), poly (oxycarbonyloxy-1,4-phenyleneisopropylidene)
1,4-phenylene), poly (oxycarbonyloxy-1,4-phenylene-1-methyl-butylidene-1,
4-phenylene), poly (oxycarbonyloxy-
1,4-phenylene-1-propyl-butylidene-1,
Bisphenol-based polycarbonate resins such as 4-phenylene).

It is most preferable to use a combination of polyethylene terephthalate as the thermoplastic resin A and polystyrene as the thermoplastic resin B. And, preferably 50 to 98 parts by weight of the thermoplastic resin A and 50 to 2 parts by weight of the thermoplastic resin B, more preferably the thermoplastic resin A70.
˜95 parts by weight and thermoplastic resin B30 to 5 parts by weight are melted and kneaded to obtain a resin composition, and the resin composition is stretch-molded. When a container such as a bottle is obtained, it can be molded using a stretch blow molding machine. The stretch blow molding machine can be either a hot parison injection blow molding machine or a cold parison injection blow molding machine.
A so-called extrusion stretch blow molding machine may be used as long as it has a stretching effect during molding and can stretch at least 1.1 times in at least one uniaxial direction. In order to obtain a container in which the wall surface has both a transparent portion and an opaque portion as in the present invention, for example, in the hot parison method of the injection blow molding method, in the preform immediately before the stretch blowing step, the surface temperature of the preform is in the temperature range. A temperature distribution is formed so as to have a portion of 90 to 125 ° C. and a portion of a temperature range of 125 to 160 ° C. (and preferably, a temperature difference between them is 5 ° C. or more), and then the temperature distribution state. It can be obtained by stretch blow molding a preform having at least 1.1 times in at least one axial direction. Any method may be used for imparting a temperature distribution to the preform in this manner. For example, the entire preform immediately before stretch-blowing is controlled to have a temperature range of 90 to 125 ° C. Infrared laser etc. may be applied to adjust any part to a temperature range of 125 to 160 ° C, or it may be heated by using a jig engraved with desired characters or patterns such as a branding mark. Then, only the characters or pattern portions may be operated so as to be in the temperature range of 125 to 160 ° C. by bringing them into contact with the preform. The temperature range on the preform is 125
The part controlled to ˜160 ° C. becomes a transparent region after stretching and blowing, and the part controlled to a temperature range of 90 to 125 ° C. becomes an opaque region.

In addition, also in the injection blow or extrusion stretch blow molding method by the cold parison method, a molded article having both a transparent portion and an opaque portion if the preform temperature immediately before the stretch blowing step is temperature controlled as described above. Is obtained. Also, when a molded product such as a sheet or a film is obtained, the temperature range is controlled to 125 to 150 ° C. and 90 to 90 ° C. in the same manner as described above.
A part having a transparent part and an opaque part can be obtained by forming a part controlled at 125 ° C. and uniaxially or biaxially stretching it.

The molded product of the present invention includes various skin lotions such as moisture lotion, massage lotion, skin lotion, cleansing lotion, emollient lotion, baby oil, cosmetic cream, vanishing cream, skin cream such as emollient cream, liquid foundation, Various face care such as creamy foundation, skin care, body care, makeup cosmetics, shampoo, conditioner, hair conditioner, perm blow agent, hair care products such as hair color, whole body cleaning, body care such as liquid hand soap, hand care products, liquid Clothing detergents, mildew removers, glass cleaners, bleaches, softeners, glues, tableware detergents, cleansers, household detergents, and other unique items such as food products and pharmaceuticals. Containers or packaging film that requires, is used in the seat.

[0016]

[Example 1]

Transparent polyethylene terephthalate [Mitsui PET J125, manufactured by Mitsui PET Resins Co., Ltd.] having an intrinsic viscosity of 0.77 and a refractive index of 1.575, and transparent polystyrene having a refractive index of 1.59 [Dialex HH102, Mitsubishi]. Kasei Polytec Co., Ltd.] was dried under reduced pressure at 70 ° C. and 760 mmHg overnight, and then mixed in a weight ratio of polyethylene terephthalate: polystyrene = 90: 10, and the mixture was mixed at a resin temperature of 250 ° C. for 2 hours. The shaft was kneaded, extruded into a strand, cooled, and cut with a cutter to obtain pellets.

The pellets are hot-parison type stretch blow molding machine (ASB50M manufactured by Nissei ASB Machine Co., Ltd.).
H) is used to first perform injection molding to form a test tubular preform. And this whole preform 11
The temperature is maintained at 3 ° C, and the temperature of the portion corresponding to the portion to be made transparent is 140 ° C. In this temperature raising operation, only a desired portion can be partly heated to a high temperature by contacting a non-contact means such as irradiation of infrared rays or a jig whose temperature is controlled with hot water or hot oil. . For example, when it is desired to make the characters of Kao transparent on the wall of the container, a jig such as a trowel trowel with a Kao stamp is brought into contact with the portion at the corresponding position, and only that portion is heated to 140 ° C.

After that, the film is transferred to a stretching and blowing step and stretched at least 1.1 times or more to be molded,
A cylindrical bottle according to the present invention was obtained in which only the part of the character "Kao" was transparent and the other parts were white and opaque. [Example 2] In Example 1, the entire preform was
While keeping the temperature at 33 ° C, cooling the part corresponding to the letters "Kao" to 113 ° C, and doing the same as above, only the portion of the letters "Kao" is white and opaque, and the other portions are A transparent cylindrical bottle according to the invention was obtained.

[Example 3] In Example 1, after the entire preform was kept at 133 ° C, the temperature was gradually lowered as it moved upward, and the lower end of the preform was set to 13 ° C.
The same stretch blow molding was performed on the preform at 3 ° C, the upper end of the preform at 113 ° C, and the middle part at this temperature. The lower end was transparent, the upper end was white opaque, and the intermediate part was A cylindrical bottle according to the present invention was obtained, which was rich in decorativeness and gradually changed between.

[Embodiment 4] In Embodiment 1, instead of transparent polystyrene having a refractive index of 1.59, a refractive index of 1.
585 transparent polycarbonate [Panlite L-12
50, manufactured by Teijin Ltd.]
When the same procedure as in Example 1 was carried out except that the temperature was 50 ° C., a cylindrical bottle according to the present invention was obtained in which only the part of the letters “Kao” was transparent and the other parts were white and opaque.

Comparative Example 1 In Example 1, instead of transparent polystyrene having a refractive index of 1.59, the refractive index was 1.
The same procedure was performed using 490 transparent polymethylmethacrylate [Delpet 560F, manufactured by Asahi Kasei Corporation].
A cylindrical bottle having a transparent portion was not obtained.

[Comparative Example 2] In Example 1, instead of transparent polystyrene having a refractive index of 1.59, the refractive index was 1.
The same procedure was performed using 510 transparent low-density polyethylene [Mirason 50, manufactured by Mitsui Petrochemical Industry Co., Ltd.], but a cylindrical bottle having a transparent portion was not obtained.

[0023]

According to the present invention, a molded product having a transparent pattern with a complicated pattern can be easily obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing a structure of a resin composition before being stretched.

FIG. 2 is a schematic view showing a structure of a resin composition at a stage after stretching.

[Explanation of symbols]

 1 matrix phase 2 dispersed phase

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C08L 69/00 LPR 101/00 LSY

Claims (4)

[Claims] 1. A thermoplastic resin A having transparency and a thermoplastic resin B having transparency are used so that a difference in refractive index in a non-oriented state at 25 ° C. is about 0.05 or less,
The thermoplastic resin A constitutes a matrix phase, and the thermoplastic resin B constitutes a dispersed phase, and the matrix phase of the thermoplastic resin A has a substantial difference in the degree of molecular orientation depending on the location. A plastic molded product having a transparent part and an opaque part. 2. The plastic molding having a transparent portion and an opaque portion according to claim 1, wherein the thermoplastic resin A and the thermoplastic resin B have a weight ratio of 50 to 98/50 to 2. body. 3. The thermoplastic resin A comprises ethylene terephthalate as a main repeating unit and has an intrinsic viscosity of about 0.
50 to 1.40. 1.
Alternatively, a plastic molding having the transparent portion and the opaque portion according to claim 2. 4. The thermoplastic resin B has a transparent portion and an opaque portion according to claim 1 or 2, wherein the thermoplastic resin B is selected from the group consisting of a styrene resin and a polycarbonate resin. Plastic molding.