JPH04366136A - Watermarked stretched molding - Google Patents

Abstract

PURPOSE:To prepare an opaque, watermarked, stretched molding which has a pearl gloss and is useful as a decorative packaging material by treating a stretched molding made from a compsn. contg. specified amts. of a specific petroleum resin and a crystalline PP resin with a solvent. CONSTITUTION:A stretched molding made from a compsn. contg. 100 pts.wt. crystalline PP resin (e.g. crystalline PP) and 20-40 pts.wt. cyclopentadiene-based petroleum resin having a softening point (ring and ball method) of 160 deg.C or higher (e.g. Arkon P125, a product of Arakawa Chemical Industry Co.,Ltd.) is treated with a solvent (e.g. toluene).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch-molded opaque film with a pearlescent luster and an openwork pattern. More specifically, the present invention relates to a stretch-molded product made by blending a petroleum resin and a polypropylene resin.

0002

BACKGROUND OF THE INVENTION Highly filled inorganic films with pearlescent luster are generally used for packaging confectionery, but it has been difficult to create transparent patterns with partial transparency. Furthermore, JP-A-61-203140 discloses a film containing polypropylene and petroleum resin, but it relates to a moisture-proof film with low water vapor permeability, that is, excellent water vapor barrier properties, and has pearl luster and transparency. There are no issues raised regarding the pattern.

0003

OBJECTS OF THE INVENTION An object of the present invention is to provide an opaque stretch-molded product with a pearlescent luster and an openwork pattern.

0004

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors have made extensive studies and have developed a molded product obtained by blending a specific amount of a specific petroleum resin into a crystalline polypropylene resin and stretching it using a specific solvent. The present inventors have discovered that a stretched molded product with a partially transparent openwork pattern can be obtained by this treatment, and the present invention has been completed.

[0005] The openwork patterned stretched molded product of the present invention contains more than 20 parts by weight to 40 parts by weight of a cyclopentadiene petroleum resin with a softening point (ring and ball method) of 160°C or higher, and 100 parts by weight of a crystalline polypropylene resin. Stretch and mold the composition,
It is characterized by an opaque stretch molded product having a pearlescent luster that is obtained by solvent treatment and having an openwork pattern with excellent transparency.

[0006] The stretching ratio in this stretching process is preferably 2 times or more in one direction at a temperature below the softening point of the cyclopentadiene petroleum resin. Further, the solvent treatment is preferably a painting treatment such as applying an aromatic or aliphatic organic solvent or an organic halogen compound solvent with a brush.

[0007] The crystalline polypropylene resin used in the transparent patterned stretched molded product of the present invention is a propylene homopolymer, a polymer containing propylene as a main component with ethylene or other α-olefin, or a polymer thereof. It is a mixture, specifically crystalline polypropylene, crystalline ethylene/propylene copolymer, crystalline ethylene/butene-1
Copolymer, crystalline propylene-hexene-1 copolymer,
Examples include crystalline ethylene/propylene/α-olefin terpolymers. Of these, it contains 70% by weight or more of a portion insoluble in n-heptane, and 70% by weight of a propylene component.
A crystalline polypropylene or copolymer containing at least % by weight is preferred.

The cyclopentadiene-based petroleum resin used in the openwork patterned stretched product of the present invention is a petroleum resin obtained by polymerizing a fraction containing a cyclopentadiene component obtained from steam cracking of petroleum naphtha, or the like. The petroleum resin hydride or a mixture thereof must have a softening point (ring and ball method) of 160° C. or higher. If the softening point does not reach 160°C, the pearlescent luster tone is insufficient, and if the softening point is low, below 150°C, it is impossible to obtain a stretched molded product with pearlescent luster. The fraction containing the above cyclopentadiene component is
It is a fraction whose main components are cyclopentadiene, dicyclopentadiene, cyclopentadiene polymers, alkyl substituted products thereof, or mixtures thereof. In addition, the above petroleum resin hydride can be obtained by hydrogenating the petroleum resin obtained by polymerizing the fraction using a catalyst such as a metal such as palladium, nickel, or cobalt or an oxide thereof in the presence of a solvent. can.

[0009] The blending composition of the transparent patterned stretch molded product of the present invention is such that cyclopentadiene petroleum resin with a softening point (ring and ball method) of 160°C or higher is added to 100 parts by weight of crystalline polypropylene resin in excess of 20 to 40 parts by weight. It can be obtained by blending in the range of parts by weight, preferably in the range of 25 to 35 parts by weight, which is optimal for achieving the purpose of the present invention. If the amount of the petroleum resin is less than 20 parts by weight, the pearlescent luster tone will be insufficient, and if it exceeds 40 parts by weight, the transparency of the film in the solvent-treated area will decrease.

[0010] In addition, in blending the crystalline polypropylene resin and the cyclopentadiene petroleum resin as described above, various additives known to be added to the polypropylene, such as known phenol-based, phosphorus-based, or thioether-based additives, may be added as necessary to the polypropylene. processing stabilizers and antioxidants such as higher fatty acids or metal salts of higher fatty acids such as calcium stearate, lubricants and slip agents such as fatty acid amide, antistatic agents, inorganic fillers such as calcium carbonate and talc, pigments, and ultraviolet rays. Absorbents, various polymers, etc. can be used in combination as long as the purpose is not impaired.

[0011] This formulation can be easily obtained by mixing a predetermined amount of the above-mentioned resin and additives as necessary using an ordinary blender or mixer. It is particularly preferable to melt-mix and obtain pellets.

[0012] The stretched molded product with a transparent pattern of the present invention is produced by melt-extruding the pellets obtained in this way to form a raw sheet, and then uniaxially or biaxially stretching the stretched molded product. It can be obtained by processing with

The stretching method may be any of the known methods such as uniaxial stretching methods such as roll stretching, oven stretching, and hot plate stretching, or simultaneous or sequential biaxial stretching such as tubular stretching and tenter stretching. By keeping the temperature of the original film at the time of stretching below the softening point of the petroleum resin in the composition and by stretching it twice or more in at least one direction, a pearlescent film, which is one of the objects of the present invention, can be obtained. Although a stretched product can be obtained, stretching is preferably performed at an area magnification of 4 times or more. Simultaneous or sequential biaxial stretching at an area magnification of about 10 to 60 times is more suitable.

[0014] In the solvent treatment method, a transparent pattern with excellent transparency can be obtained by applying a solvent with a brush or the like to the stretched product obtained by the above-mentioned stretching, but this method is not suitable for industrial use. For example, an openwork pattern with excellent transparency can be produced by stamping with a solvent holding plate molded into a desired shape.

[0015] The solvent used in the solvent treatment of the stretch molded article with a transparent pattern of the present invention is an aromatic or aliphatic organic solvent or an organic halogen compound solvent, such as benzene, toluene, xylene, cyclohexane, trichloroethylene, and chlorform. , n-hexane, etc. are suitable, and among them, toluene is most suitable.

[0016] The stretched molded product with an openwork pattern of the present invention before solvent treatment, that is, the portion of the stretched stretched molded product with a openwork pattern that is not subjected to solvent treatment, has many fine voids inside thereof, and all of them are It is characterized by a light transmittance of 40% or less, and if the total light transmittance exceeds 40%, the opacity is insufficient and a stretched molded product with a unique pearly feel cannot be obtained. Total light transmittance is 30% or less, apparent density is 0.
Stretched products with a diameter of 75 or less are particularly preferred since they have excellent opacity and pearl-like luster.

[0017] The openwork patterned stretched molded product obtained in the present invention may be subjected to surface treatment such as corona treatment or plasma treatment in an atmosphere of air, oxygen, or nitrogen, if necessary.

[0018] The stretched molded product with a transparent pattern of the present invention is an opaque pearlescent molded product processed with a highly transparent transparent pattern, and can be used for markings and contents that are effective when displaying products. You can obtain film-processed products that can be used to promote sales of products, such as packaging materials with viewing windows that allow you to clearly see things.

(Examples and Comparative Examples) The present invention will be explained in more detail below using Examples and Comparative Examples, but the present invention is not limited by these Examples. The cyclopentadiene petroleum resins used in the following Examples and Comparative Examples and evaluation of their characteristic values are shown below.

Cyclopentadiene petroleum resin (DCPD)
It is abbreviated as ) A fraction consisting of 75% by weight of dicyclopentadiene and saturated hydrocarbons obtained by steam cracking of petroleum naphtha is thermally polymerized in xylene in a nitrogen atmosphere by a known method, unreacted materials and solvent are removed, and In the second stage of polymerization, the polymer was maintained at a temperature of 200° C. or higher for a certain period of time under reduced pressure, and then cooled and solidified. Cyclopentadiene petroleum resin hydride (abbreviated as DCPD hydride)
A hydrogenated resin obtained by hydrogenating the above DCPD by a known method described in this article was used. Alicyclic resin: “Alcon P1” manufactured by Arakawa Chemical Industry Co., Ltd.
25" was used.

The softening point, melt flow rate, and total light transmittance shown in Examples and Comparative Examples were measured by the following methods. (1). Softening point (°C; ball sensitivity method): JIS K2207
Compliant with. (2). Melt flow rate (MFR; g/10): J
Compliant with IS K7210-1776. (3). Total light transmittance (%): JIS K-6714
Compliant with.

(Example) 100 parts by weight of crystalline polypropylene powder with MFR 2.1 containing 96% of components insoluble in n-heptane, phenolic antioxidant BHT
0.2 parts by weight, 0.1 parts by weight of calcium stearate,
30 parts by weight of DCPD hydride with a softening point (ring and ball method) of 176°C and 0.1 part by weight of glycerin monostearate were mixed in a Henschel mixer, then passed through an extruder and melt-mixed at 230°C, cooled and mixed. A pellet-like composition was obtained by cutting. The resulting composition was made into a T with a diameter of 40 mm.
Melt extrusion was performed at a temperature of 270°C using a T die of an extruder for die, and quenched with a mirror cooling roll kept at 50°C to a thickness of 1.
．． An unstretched raw sheet of mm was obtained. Next, this original fabric sheet was cut into squares, and using a Pandagraph type biaxial stretching machine, at a temperature of 152°C, the original fabric was stretched 5 times simultaneously in the vertical direction (resin flow direction) and the perpendicular (horizontal) direction thereof. It was stretched and heat treated under tension at the same temperature for 10 seconds to obtain a biaxially stretched molded product. Next, this biaxially stretched molded product was painted with a brush impregnated with toluene solvent as a solvent treatment to obtain a stretched molded product with an openwork pattern. Table 1 shows the total light transmittance of the solvent-untreated portion (the biaxially stretched molded product before solvent treatment) and the solvent-treated portion (the transparent portion) of the stretch molded product with a transparent pattern having pearl luster.

(Comparative Example 1) A stretched molded product was prepared in accordance with the example except that the amount of cyclopentadiene petroleum resin added was 10 parts by weight. This stretched molded product had a small difference in total light transmittance between the solvent-untreated part and the solvent-treated part, lacked pearlescent luster, and the transparency did not appear clear. (Comparative Example 2) A stretched molded product was prepared in accordance with Example 1 except that an alicyclic resin having a softening point of 125° C. was used instead of the cyclopentadiene petroleum resin. This stretched product had no pearlescent luster and was entirely transparent, with no transparent pattern.

[0024]

[Table 1]

As is clear from the total light transmittance values in Table 1, the stretched molded product according to the present invention of Example 1 has a small total light transmittance value in the solvent-untreated portion, is opaque, and has a pearlescent tone. However, the solvent-treated part is transparent and is a stretch-molded product with a pearlescent luster with a transparent pattern. On the other hand, in Comparative Example 1, the solvent-treated portion was transparent, but the untreated portion lacked opacity and had no pearlescent luster, and the transparent pattern was not substantially clear. Comparative Example 3 has no opacity or pearlescent luster, is entirely transparent, and has no transparent pattern.

[0026]

Effects of the Invention The stretched molded product with a transparent pattern of the present invention is an opaque pearlescent film having a highly transparent transparent pattern. That is, by adding a watermark pattern with excellent transparency to a pearlescent film in a desired shape, a dramatic sense of luxury can be obtained. for example,
This makes it possible to provide packaging materials that were previously unavailable, such as the ability to add a peep window to give a sense of luxury to various decorative packaging materials such as confectionery packaging and to show off the contents.

Claims (2)

[Claims] Claim 1: A stretched and molded product having a blend composition of more than 20 parts by weight of a cyclopentadiene petroleum resin with a softening point (ring and ball method) of 160° C. or higher and 40 parts by weight and 100 parts by weight of a crystalline polypropylene resin is treated with a solvent. A stretch molded product with a transparent pattern that has a pearlescent luster. 2. The openwork patterned stretched molded product according to claim 1, wherein the stretching is at least twice as long in at least one direction at a temperature below the softening point of the cyclopentadiene petroleum resin.