JP2003128853A - Polypropylene resin composition and polypropylene resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an injection-molded product which is the one obtained by using a polypropylene resin composition and which has improved physical properties such as impact property, weld property, and heat resistance while maintaining decorative feelings (appearance patterns), e.g. appearances like cloth, stone and the like. SOLUTION: The polypropylene resin composition contains, to 100 parts by weight of a polypropylene type resin (A), 0.1-0.8 part by weight of a pigment (B) and 0.45-0.9 part by weight of a colored viscose rayon fiber (C) having a size of 1-10 deniers (diameter 10-31 μm) and a fiber length of 0.2-1.0 mm. The polypropylene resin molding therefrom is also provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection-molded article of a polypropylene resin composition having appearances such as texture and stone tones, impact resistance, weldability and heat resistance.

[0002]

2. Description of the Related Art Heretofore, as a material for automobile parts or home electric appliances, there has been a method in which a polypropylene resin composition contains a pigment and fibers so that an appearance pattern such as a texture or a stone tone is exhibited. Among them, a method of increasing the fiber concentration in the polypropylene resin composition has been taken in order to enhance the decorative feeling such as texture and stone. However, increasing the fiber concentration not only leads to an economically disadvantageous situation, but also has a problem that the impact property as a mechanical property value is lowered.

As a countermeasure, there has been adopted a method of giving a decorative feeling such as a cloth tone or a stone tone by decreasing the pigment concentration in the polypropylene resin composition to increase the transparency and make the presence of the fibers more noticeable. However, in this method, the weld line became conspicuous due to the effect of increasing the transparency by lowering the pigment concentration, which caused a problem in the appearance of the product.

As the fibers used to make appearance patterns such as texture and stone tones, colored viscose rayon fibers are often used. this is,
The reason is that viscose rayon fibers can be colored relatively easily by a method such as undiluted solution coloring or post-dyeing with dyes and pigments, and that they are economical. However,
These colored viscose rayon fibers have a problem in heat resistance, and there have been problems such as discoloration in high temperature molding and molding after retention. Although there is almost no problem in normal molding of a polypropylene resin composition, high temperature molding may be performed in order to increase the fluidity of the resin when it is required to make the molded product thinner or more complicated. In addition, the molding resin may be retained in a molten state in the molding machine cylinder when the mold is exchanged during the molding operation, the molding conditions are adjusted, or during breaks. Under these circumstances, heat resistance is required, but generally colored viscose rayon fibers are easily discolored, and when the pigment concentration is lowered to make the decorative feeling of the fibers noticeable as described above, it is particularly There is a problem that apparent heat resistance is poor because discoloration is noticeable.

[0005]

[Problems to be Solved by the Invention] Under these circumstances,
A polypropylene resin composition and a polypropylene resin molded product are desired, in which the impact resistance of injection molded products, the visibility of weld lines, and the deterioration of apparent heat resistance are suppressed as much as possible, while maintaining the decorative feeling such as texture and stone tone. Was there.

[0006]

Means for Solving the Problems The present invention provides a polypropylene resin composition containing a pigment and a fiber when injection-molded.
It is a method of making appearance patterns such as cloth tone and stone tone appear on a molded product, and particularly, by limiting the pigment concentration, the type of fiber, the size and the concentration in the polypropylene resin composition, the appearance pattern is impaired. The present invention relates to a means for obtaining a molded article which improves the quality of impact resistance, weldability and apparent heat resistance without any damage.

That is, the first aspect of the present invention is to provide a polypropylene resin (A), a pigment (B), a fineness of 1 to 10 denier (diameter of 10 to 31 μm) and a fiber length of 0.2 to 1.
A polypropylene resin composition comprising 0 mm of colored viscose rayon fiber (C), wherein 0.1 parts of the pigment (B) is added to 100 parts by weight of the polypropylene resin (A).
~ 0.8 parts by weight, viscose rayon fiber (C) 0.4
The polypropylene resin composition contains 5 to 0.9 parts by weight.

A second invention is a polypropylene resin (A), a pigment (B), and a fineness of 1 to 10 denier (diameter 1
A polypropylene resin molded article comprising colored viscose rayon fibers (C) having a fiber length of 0 to 31 μm) and a fiber length of 0.2 to 1.0 mm, wherein the polypropylene resin (A)
A polypropylene resin molded product characterized by containing 0.1 to 0.8 parts by weight of a pigment (B) and 0.45 to 0.9 parts by weight of a viscose rayon fiber (C) with respect to 100 parts by weight.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The polypropylene resin (A) used in the present invention includes crystalline or amorphous homopolypropylene, ethylene-propylene random copolymer,
Examples thereof include an ethylene-propylene block copolymer and a copolymer of α-olefin and ethylene or propylene. These may be used alone or in combination of two or more. Further, it may contain talc, calcium carbonate, barium sulfate, a rubber component, an elastomer component and the like.

The pigment (B) used in the present invention includes
Known organic pigments and inorganic pigments conventionally used for coloring polyolefin resins can be used. Examples include organic pigments such as azo, anthraquinone, phthalocyanine, quinacridone, isoindolinone, dioxane, perylene, quinophthalone, and perinone, titanium oxide, titanium yellow, ultramarine blue, cobalt blue, and rouge. ,
Inorganic pigments such as composite oxides and carbon black can be used. These may be used alone or in combination of two or more.

The amount of the pigment (B) blended is preferably 0.1 to 0.8 parts by weight with respect to 100 parts by weight of the polypropylene resin (A). If the amount is less than 0.1 parts by weight, the transparency of the polypropylene resin molded product will be improved and the viscose rayon fiber will have a good decorative feel, but the weld of the molded product will be extremely noticeable and the apparent heat resistance may be reduced. . If it exceeds 0.8 parts by weight, the weld and the apparent heat resistance are improved, but the pigment hides the fibers, and the decorative feeling may be deteriorated.

Further, the colored viscose rayon fiber (C) used in the present invention is prepared by using a dye or a pigment.
Pre-colored by a method such as undiluted coloring or post-dyeing. In addition, fineness 1-10 denier (diameter 10-31
μm) and a fiber length of 0.2 to 1 mm, particularly preferably a fineness of 2 to 5 denier (diameter 14 to 22 μm) or a fiber length of 0.3 to 0.7 mm. Since the unit of denier is influenced by the specific gravity of the fiber, the value of the diameter corresponding to the denier of the fiber used in the present invention is also shown. When the fineness is less than 1 denier, the fibers in the molded product are not conspicuous and the decorative feeling is poor. When the fineness is more than 10 denier, the fibers are too conspicuous and the decorative feeling is not good. Further, when the fiber length is less than 0.2 mm, the fibers in the molded product are not conspicuous and the decorative feeling is poor, the cost of cutting the fibers is high, and the economical efficiency is impaired. When the fiber length exceeds 1 mm, the fibers are too conspicuous, and a good decorative feeling cannot be obtained.

The blending amount of the colored viscose rayon fiber (C) with respect to 100 parts by weight of the polypropylene resin (A) is preferably 0.45 to 0.9 part by weight. If the amount is less than 0.45 parts by weight, the viscose rayon fiber may be inconspicuous and may not give a decorative feeling, and if the amount is more than 0.9 parts by weight, mechanical properties may be deteriorated.

The polypropylene resin composition of the present invention can be used as a masterbatch containing a high concentration of pigment and fiber and diluted with the resin to be colored during the production of a molded article, or the concentration of pigment and fiber can be increased. The composition is relatively low and has the same composition as that of the molded product, and can be used as a compound that is directly subjected to molding without being diluted with the resin to be colored.

The polypropylene resin composition of the present invention comprises
To the extent that the effects of the present invention are not impaired, low density polyethylene,
High density polyethylene, linear low density polyethylene, etc. Resin, polyethylene wax, polypropylene wax, etc. wax, carbon fiber, stainless steel fiber, synthetic fiber carbonized, etc. Do not melt or soften at the molding temperature of polypropylene resin composition Add various additives such as fiber, antioxidant, UV absorption, stabilizer, plasticizer, antistatic agent, flame retardant, filler, reinforcing agent, surfactant, coupling agent, nucleating agent, lubricant, etc. You can also

[0016]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples and has a wide range of applications. In the examples, “part” means “part by weight” and “%” means “% by weight”. Various properties of the polypropylene resin compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated by the methods described below, and the results are shown in Table 1.

(Evaluation of Decorative Feeling) Pellets of polypropylene resin composition were manufactured at a molding temperature of 220 ° C. using an injection molding machine (Toshiba IS75E) and a mold having a matte texture pattern. The formed plate was visually evaluated for decorative texture such as texture and stone texture. When the decorativeness was good, such as having a fibrous feeling and softness, the result was ◯; when the decorative feeling was poor, such as a poor fibrous feeling, the result was ×;

(Impactability evaluation) A test piece mold was used in accordance with ASTM Izod impact measurement (ASTM D-256), and the test piece was injection-molded in the same manner as the decorative feeling evaluation.
The evaluation was carried out according to the Izod impact measurement method of STM.

(Welding evaluation) The plate was injection-molded in the same manner as in the decorative evaluation except that a mold for injecting resin with a four-point gate from the center to inject a resin to mold a 150 x 350 x 2 tmm plate was used. The welds formed at four places were visually observed. When the weld was not conspicuous, it was rated as O, when the weld was conspicuous, it was rated as C, and when it was between the two, it was rated as Δ.

(Heat resistance) Except for the conditions that the molding temperature is 230 ° C., the residence time in the cylinder of the molding machine is 0 minutes, 30 minutes, and 60 minutes (0 minutes is continuous molding), the satin textured plate is used in the same manner as in the decorative evaluation. Injection molded. The color difference ΔE of the obtained plate was measured using a colorimeter (Aucara 10 system (manufactured by Kurabo), light source D65, 10 ° field of view. A standard color was a molded product having a molding temperature of 220 ° C and a residence time of 0 minutes. ). ΔE ≧ 1 was regarded as poor apparent heat resistance.

Example 1 Ethylene-propylene block copolymer 100 parts (containing 20% talc, MI30) Titanium oxide 0.5 parts Rouge 0.1 parts Carbon black 0.1 parts Viscose rayon fiber-A 0 0.7 parts (black, fineness 3 denier (diameter 18 μm), fiber length 0.5 mm) Polyethylene wax 0.5 parts The above composition was premixed with a high speed mixer, and then melt-kneaded with an extruder or the like to form a compound pellet. Was produced. The pellets were molded by an injection molding machine (Toshiba IS75E) into various molded articles for test evaluation and evaluated.

Example 2 Ethylene-Propylene Block Copolymer 100 Parts (Talc 20% Contained, MI30) Titanium Oxide 0.2 Parts Rouge 0.1 Parts Viscose Rayon Fiber-B 0.25 Parts (Black) , Fineness 3 denier (diameter 18 μm), fiber length 0.3 mm) Viscose rayon fiber-C 0.25 part (brown, fineness 3 denier (diameter 18 μm), fiber length 0.5 mm) magnesium stearate 0.2 parts Using the above composition, compound pellets were prepared in the same manner as in Example 1, and molded articles were molded and evaluated.

Comparative Example 1 100 parts of ethylene-propylene block copolymer (containing 20% talc, MI30) Titanium oxide 1.0 part Rouge 0.2 parts Carbon black 0.15 parts Viscose rayon fiber-A 1 .2 parts (black, fineness 3 denier (diameter 18 μm), fiber length 0.5 mm) polyethylene wax 0.5 parts Using the above composition, compound pellets were prepared in the same manner as in Example 1 to form a molded product. And evaluated.

Comparative Example 2 100 parts of ethylene-propylene block copolymer (containing 20% talc, MI30) Titanium oxide 0.05 parts Rouge 0.02 parts Viscose rayon fiber-B 0.15 parts (B: Black, fineness 3 denier (diameter 18 μm), fiber length 0.3 mm) Viscose rayon fiber-C 0.15 parts (C: brown, fineness 3 denier (diameter 18 μm), fiber length 0.5 mm) Magnesium stearate 0.2 parts Using the above composition, compound pellets were prepared in the same manner as in Example 2, and a molded product was molded and evaluated.

[Example 3] Ethylene-propylene block copolymer (MI45) 71.0 parts Titanium oxide 5.0 parts Carbon black 0.5 parts Phthalocyanine green 1.5 parts Viscose rayon fiber-A 12.0 parts (Black color, fineness 3 denier (diameter 18 μm), fiber length 0.5 mm) Polyethylene wax 10.0 parts The above composition is premixed with a high speed mixer, then melt-kneaded with an extruder to prepare pigment and viscose rayon. A masterbatch-A in which fibers were blended in a high concentration was prepared. Masterbatch-A 5.0 parts Polypropylene resin as a resin to be colored 100 parts (Talc 20% content, MI30) The above mixture (100 parts polypropylene resin, 0.35 parts pigment, 0 viscose rayon fiber) A molded product was molded in the same manner as in Example 1 using an injection molding machine (Toshiba IS75E), and the evaluation was performed.

[Example 4] Ethylene-propylene random copolymer (MI20) 40.0 parts Titanium oxide 3.0 parts Carbon black 0.3 parts Phthalocyanine green 1.0 parts Viscose rayon fiber-D 10.0 parts (D: black, fineness 3 denier (diameter 18 μm), fiber length 0.8 mm) polyethylene wax 8.0 parts low density polyethylene (MI20) 37.7 parts The above composition was premixed with a high speed mixer, and then an extruder was used. Was melt-kneaded to prepare a masterbatch-B in which a pigment and viscose rayon fiber were blended at a high concentration. Masterbatch-B 5.0 parts Polypropylene resin as a resin to be colored 100 parts (Talc 20% content, MI30) The above mixture (100 parts polypropylene resin, 0.215 parts pigment, 0 viscose rayon fiber) (Corresponding to 0.5 parts) is premixed with a high-speed mixer and then melt-kneaded with an extruder or the like to prepare pellets, and the pellets are molded with an injection molding machine (Toshiba IS75E) in the same manner as in Example 1. And evaluated.

Comparative Example 3 Ethylene-propylene block copolymer (MI45) 57.5 parts Titanium oxide 16.0 parts Carbon black 1.2 parts Phthalocyanine green 3.3 parts Viscose rayon fiber-A 12.0 parts (Black system, fineness 3 denier (diameter 18 μm), fiber length 0.5 mm) Polyethylene wax 10.0 parts Masterbatch-C using the above composition in the same manner as in Example 3.
To produce a molded product (polypropylene resin 100
1.025 parts of pigment and 0.6 parts of viscose rayon fiber were molded for each part) and evaluated.

Comparative Example 4 Ethylene-Propylene Random Copolymer (MI20) 40.0 parts Titanium oxide 3.0 parts Carbon black 0.3 parts Phthalocyanine green 1.0 parts Viscose rayon fiber-E 10.0 parts (E: Black, fineness 3 denier (diameter 18 μm), fiber length 1.5 mm) Polyethylene wax 8.0 parts Low density polyethylene (MI20) 37.7 parts Instead of the viscose rayon fiber-D of Example 4, D
And the above composition containing viscose rayon fiber-E different in fiber length from the above, using the same composition as in Example 4, masterbatch D, and a molded product (corresponding to 0.215 parts of pigment to 100 parts of polypropylene resin). ) Was molded and evaluated.

[0029]

[Table 1]

[0030]

The polypropylene resin composition of the present invention is
Since the pigment content and the fineness / fiber length and content of the viscose rayon fiber are limited, the injection-molded product obtained using this has reduced impact resistance, visibility of weld lines, and apparent heat resistance. The deterioration is suppressed and the decorative feeling such as texture and stone texture can be maintained. In particular, a molded product having a good apparent heat resistance can be obtained even when molded at a high temperature or when a residence time occurs. Further, since the polypropylene resin molded product of the present invention limits the content of the pigment and the fineness / fiber length and content of the viscose rayon fiber, the impact resistance is lowered, the weld line is easily noticeable, and the apparent heat resistance is reduced. It is possible to suppress the deterioration of the property and to maintain the decorative feeling such as texture and stone. In particular, a molded product having a good apparent heat resistance can be obtained even when molded at a high temperature or when a residence time occurs.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 1:24) F term (reference) 4F071 AA09 AA14 AA20 AD01 AE09 AE17 AF45 AH03 BB05 BC03 4J002 AB012 BB111 BB121 BB141 BB151 BP021 FA042 FD012 FD096 GL00 GL01 GL02

Claims (2)

[Claims] 1. A polypropylene resin (A), a pigment (B), and a fineness of 1 to 10 denier (diameter 10 to 31 μm).
m) and a polypropylene resin composition comprising colored viscose rayon fibers (C) having a fiber length of 0.2 to 1.0 mm, wherein the pigment (B) is 0 relative to 100 parts by weight of the polypropylene resin (A). 1 to 0.8 parts by weight, and 0.45 to 0.9 parts by weight of viscose rayon fiber (C), a polypropylene resin composition. 2. A polypropylene resin (A), a pigment (B), and a fineness of 1 to 10 denier (diameter 10 to 31 μm).
m) and a polypropylene resin molded article composed of colored viscose rayon fibers (C) having a fiber length of 0.2 to 1.0 mm, wherein the pigment (B) is 0 relative to 100 parts by weight of the polypropylene resin (A). 1 to 0.8 parts by weight, and 0.45 to 0.9 parts by weight of viscose rayon fiber (C), a polypropylene resin molded article.