JP2001219516A - Highly visualizing composite resin molded article excellent in low temperature impact resistance and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly visualizing composite resin molded article having not only excellent low temperature impact resistance bur also appearance good in surface gloss and excellent in deep design effect. SOLUTION: The highly visualizing composite resin molded article excellent in low temperature impact resistance has a composite resin layer containing organic fibers modified by an optic nerve stimulating substance such as a color substance, a reflective substance, a fluolescent substance or a luminous substance and a polyolefinic resin. The center portion in the thickness direction of the resin layer comprises a composite layer wherein organic fibers are uniformly dispersed in a polyolefinic resin. The surface layer portion thereof only comprises a substantially transparent thermoplastic resin same to or different from the polyolefinic resin and having a softening point lower than that of the polyolefinic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite resin molded article having excellent low-temperature impact resistance, good surface gloss, deep appearance and excellent design, and a method for producing the same. Resin molded products include, for example, home appliance parts such as air conditioners, refrigerators, vacuum cleaners, desk lamps, electronic devices such as computers, monitors, and mobile phones, light electric device parts, office base materials, office base materials such as cabinets, furniture parts, It can be effectively used as a material for various parts that require aesthetic design, such as household accessories such as buckets, washbasins, pencil cases, and letter cases, and stationery.

[0002]

2. Description of the Related Art Many composite resin materials have been proposed as composite resin materials applicable to the above-mentioned various articles requiring an aesthetic design feeling, and some of them have been put to practical use. As one of them, there is a technique for enhancing the aesthetics of a molded product by combining a colored fiber with a thermoplastic resin.

[0003] Among them, the one that has recently attracted attention is a thermoplastic resin having a matrix component, in which colored fibers are dispersed to give a marble-like (stone-grained) appearance. Japanese Patent Application Laid-Open No. 51-123248 discloses a thermoplastic resin in which 0.05 to 5% by mass of a colored cellulose fiber is blended in a thermoplastic resin to give a fine spot pattern.
Japanese Patent Application Laid-Open No. H11-150003 discloses a method in which a different color thermosetting resin is mixed and used, and about 0.01 to 1% by mass of a coloring fiber is dispersed therein to give a natural stone-like appearance pattern. Japanese Patent Application Laid-Open No. 3-52942 discloses that a colored synthetic fiber having a specified fiber diameter and fiber length is blended in an amount of 0.1 to 10% by mass to give a stone-like tone. Japanese Patent Application Laid-Open (JP-A) No. 4-348155
In the publication, a coloring fiber having an identified aspect ratio is blended into SMC (sheet molding compound),
Japanese Patent Application Laid-Open No. 7-242, in which a molded product is provided with a marble pattern.
No. 832 discloses a surface-treated colored organic fiber 0.1.
There has been proposed a composition in which a molded product having a stone-like pattern is obtained by blending 10 to 10% by mass with a thermoplastic resin.

Japanese Patent Laid-Open Publication No. Sho 60-139876 discloses a technique in which a colored fiber woven fabric is compounded as a reinforcing material with a transparent rubber and used as a belt or hose material with an improved appearance.

[0005] In addition, a number of methods are known in which various synthetic organic fibers such as polyester, nylon, vinylon, and aramid are combined with a synthetic resin as a reinforcing material for improving impact resistance (Japanese Patent Application Laid-Open No. 62-146945). JP-A 1-2
No. 79974, JP-A-1-207357, JP-A-3-207
290453, JP-A-4-202545 and JP-A-6
-306216, JP-B-6-25288, etc.).

The present inventors have been developing composite molded articles which effectively utilize colored organic fibers as components for improving aesthetics and physical properties. Particularly, polyolefins having excellent moldability and a good balance between physical properties and cost. Research is being carried out with the aim of developing a technique that uses a system resin as a matrix material, strengthens it with organic fibers, and colors it to give it an aesthetic appearance.

A method widely used to enhance the aesthetic design by coloring a polyolefin resin such as polypropylene is to knead the polyolefin resin with a pigment or a dye. Is merely kneaded with a polyolefin resin, the color tone becomes dull (matte), and a high-quality transparent color cannot be obtained. Further, a method of coloring by adding a dye to a translucent to transparent polyolefin resin is also known, but those having high transparency generally have low impact resistance, low elastic modulus and low heat resistance. Physical properties are not enough. It is conceivable to add a rubber component to enhance low-temperature impact resistance. However, since rubber generally has low compatibility with a polyolefin-based resin, transparency is impaired and color development becomes dull, so that a high-grade feeling cannot be obtained.

Therefore, a method of applying a clear coating to the surface of a molded article made of the above-mentioned material or laminating a transparent film to give surface gloss and give depth to color development is also conceivable. However, polyolefin resins generally have poor adhesion to paints, so it is difficult to form a strong clear coating film, and it is difficult to obtain satisfactory film adhesion even when a method of attaching a transparent film is used.
In addition, the shape of a molded product that can be applied is naturally limited due to the necessity of laminating the film so that the film is not wrinkled.

On the other hand, it is considered effective to add a colored organic fiber as a coloring component to the polyolefin resin, and if this method is used, the effect of reinforcing the organic fiber is also effectively exhibited, so that a modification to the low-temperature impact resistance is required. It is considered that the quality effect is also exhibited. However, in this method, a part of the colored organic fiber is exposed on the surface of the molded article, so that it is difficult to obtain a surface gloss,
In addition, it is not possible to obtain a deep, high-grade color tone.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to use a polyolefin resin which is inexpensive and has excellent moldability and physical properties as a main matrix material. It is an object of the present invention to provide a molded article which is effectively utilized and has a high glossiness and a deep, high-grade appearance while improving the color tone which is a disadvantage thereof, and also has excellent low-temperature impact resistance.

[0011]

Means for Solving the Problems The composite resin molded article according to the present invention, which can solve the above-mentioned problems, comprises a composite resin layer containing an organic fiber modified with a visual nerve stimulating substance and a polyolefin resin. The resin layer has a composite layer in which organic fibers are uniformly dispersed in a polyolefin-based resin on the center side in the thickness direction, and a surface layer is a thermoplastic resin of the same or different type as the polyolefin-based resin. It has a gist in a place made of a transparent thermoplastic resin having a lower softening point than that of the base resin.

The above-mentioned visual nerve stimulating substance is a general term for a substance which appeals to the sight and gives an aesthetic appearance. The most common one is a coloring material (pigment or dye). The term generically refers to metal plating, sputtering, metal deposition, and the like applied to the surface of particles, metal strips, or organic fibers. In the following description, these may be referred to as “colorants”.

As the organic fibers, any organic fibers can be used as long as they have heat resistance enough to withstand heat molding. However, cost, heat resistance (yellowing resistance), low-temperature impact resistance improvement effect, or modification by a coloring material can be used. Polyester fibers having good quality are preferable. These organic fibers can give a stable coloring state and low-temperature impact resistance by being blended in the range of 3 to 40% by mass in the total amount of the molded article. It is preferable because it is possible. Further, the thickness of the surface layer is preferably in the range of 5 to 100 μm, whereby the appearance and impact resistance of the composite resin molded product can be more reliably improved.

When the thermoplastic resin is a polyolefin resin, that is, when the thermoplastic resin is of the same type as the polyolefin resin constituting the central layer, the MFR of the molten mixture at 230 ° C. and 2.16 kgf is used. Is 15 g / 10 min to 200 g / 10 min, more preferably 3 g / 10 min.
0 g / 10 min to 150 g / 10 min, more preferably 40 g / 10 min
It is preferably from g / 10 minutes to 100 g / 10 minutes.
Further, when the surface transparent resin layer is a polyolefin resin, the molecular weight by GPC is preferably 50,000 or less. On the other hand, when the surface transparent resin layer is a thermoplastic resin other than the polyolefin resin, the molecular weight is preferably less than 50,000. It is preferable that the thermoplastic resin has a softening point lower by 10 ° C. or more than the softening point of the polyolefin resin.

Further, the production method according to the present invention is positioned as a method capable of easily and reliably producing the above-mentioned composite resin molded product having excellent low-temperature impact resistance and visual characteristics.
The first method is to heat-mold a mixture of an organic fiber modified with a visual nerve stimulating substance and a polyolefin resin at a temperature lower than the melting point of the organic fiber and higher than the melting point of the polyolefin resin. By having the polyolefin resin melt and flow toward the inner wall surface of the mold in the mold, the gist is that a transparent coating layer made of the polyolefin resin is formed on the surface layer side, and the polyolefin resin used here is used. The resin has a molecular weight of 5 according to GPC.
A polyolefin-based resin containing 5 to 40% by mass of 000 or less is preferably used.

[0016] In the second production method, a mixture of an organic fiber modified with a visual nerve stimulating substance, a polyolefin resin, and a thermoplastic resin having a softening point lower than that of the polyolefin resin is used. Heat molding at a temperature lower than the melting point and higher than the melting point of the polyolefin resin and the thermoplastic resin, and the thermoplastic resin is melted and flown to the inner wall surface of the mold in the mold, thereby forming the thermoplastic resin on the surface layer side. It has a gist in forming the main transparent coating layer, as the thermoplastic resin used at this time,
The softening point is 10 times higher than the softening point of the polyolefin resin.
It is desirable to use a material having a temperature lower than or equal to ° C.

In carrying out these manufacturing methods, the visual nerve stimulating substance may be a coloring substance, a reflective substance, a fluorescent substance, a luminous substance, etc., alone or in combination of two or more as necessary. The organic fibers are preferably polyester fibers, and the preferable content of the organic fibers is in the range of 3 to 40% by mass.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Under the above-mentioned problems, the present inventors have proposed a method for coloring a polyolefin resin,
Research was conducted in the direction of blending colored organic fibers. That is, in the method in which colored organic fibers are blended into the originally colorless and transparent polyolefin resin, the dull appearance is reduced as compared with the method in which the content and the dye are kneaded with the resin and colored. However, in the case where the colored organic fiber is blended, as described above, it is inevitable that a part of the colored fiber is exposed on the surface of the molded article, so that the surface gloss is lowered and the appearance of the matte appearance is not small. It is becoming.

Therefore, even if the colored organic fiber is blended, if all of the colored organic fiber can be held at a position deep from the surface layer without exposing a part of the colored organic fiber to the surface. The inventors considered that the matte feeling due to the exposed fibers could be eliminated and excellent surface gloss and deep color could be obtained, and the research was conducted to obtain a molded product having such a layer structure.

As a result, if a specific amount of colored organic fiber is blended as a colorant with the polyolefin resin and this is heat-molded (injection molding, heat compression molding, etc.) under a predetermined temperature condition, the heat-molding step can be carried out. The low melt viscosity component (low softening point component) contained in the polyolefin resin melts and flows to the surface layer, and a transparent coating layer of the polyolefin resin alone is formed on the inner wall surface of the mold. As a result, the surface layer is transparent. It was found that a uniform dispersion layer of a polyolefin-based resin and colored organic fibers was formed at the center in the thickness direction, consisting of a coating layer composed of only the polyolefin-based resin.

The reason is considered as follows. That is, in the heat molding process such as injection molding, the polyolefin resin constituting the matrix is initially all melted, but in the cooling and solidifying process, the high molecular weight component in the polyolefin resin solidifies relatively quickly. On the other hand, the cooling and solidification of the low molecular weight component is relatively delayed. That is, since the low molecular weight component maintains the molten fluid state until relatively late, only the low molecular weight component maintaining the molten state at the end of solidification of the molded article is cast on the surface side and then solidified. Finally, a transparent resin layer of a relatively low softening point polyolefin resin alone is formed on the surface side, and a uniform mixed layer of a relatively high molecular weight polyolefin resin and organic fibers is formed on the center side. Believe in things.

Therefore, when the composite resin molded article of the present invention is subjected to heat molding, a polyolefin resin containing a low molecular weight material having a relatively low softening point in the final solidification step should be used, and preferably all polyolefin resin is used. Use a resin whose molecular weight (measured by GPC: the same applies hereinafter) contained in the base resin has a content of a low molecular weight material of 50,000 or less of 5 to 40% by mass, more preferably 10 to 30% by mass. It is desirable, when using such a polyolefin resin,
A transparent coating layer mainly composed of the low molecular weight polyolefin resin is formed on the surface layer side of the obtained composite resin molded article, and a relatively high molecular weight (high softening point) polyolefin resin is colored on the center side. A uniform mixed layer with the organic fibers will be formed.

If the molding conditions are appropriately controlled so that the thickness of the transparent polyolefin resin layer formed in the heat molding step is in the range of 5 to 100 μm, the surface gloss is excellent and the sense of quality is deep. Thus, a molded article having an aesthetic appearance having the following characteristics can be obtained. The preferable thickness of the transparent resin layer is in the range of 5 to 100 μm,
When it is less than 1, the effect of providing a color with depth as a transparent coating layer is not only poor, but also the effect of improving the surface gloss is insufficient.
This is because if the thickness exceeds 00 μm, the mechanical properties (such as impact resistance) of the molded article tend to decrease.

In the above description, the case where both the resin constituting the surface layer and the center layer is a polyolefin resin has been described. However, a polyolefin resin is used as a matrix resin and has compatibility with the polyolefin resin. And when the other thermoplastic resin having a softening point lower than that of the polyolefin-based resin by 10 ° C. or more is used in combination, and a mixture of these and a colored organic fiber is heat-molded, a relatively high softening point is obtained when the mixture is cooled and solidified. As a result, the polyolefin-based resin solidifies first in a mixed state with the organic fiber, and the other thermoplastic resin, which maintains a molten state at the time of the solidification, finally casts and solidifies on the surface layer side of the molded product, resulting in In the composite resin molded product, the center layer becomes a composite reinforced layer in which the polyolefin resin and the colored organic fibers are uniformly mixed, and the surface layer has Finally will be transparent coating layer of other thermoplastic resin principal cast and solidified the low softening point flow on the surface layer side is formed.

Therefore, in this case, the surface layer is made of the other transparent resin layer mainly composed of the thermoplastic resin, and the center side has a composite reinforcing layer made of a uniform mixture of a polyolefin resin and colored organic fibers. In this case, in order to form a transparent surface layer having an appropriate thickness that does not contain organic fibers by casting at the end of heat molding, the amount of the other thermoplastic resin should be about 5% by mass or more based on the total amount. , More preferably 10 to 30
It is desirable that the thickness be adjusted to the range of 5% by mass.
It can be adjusted to a range of １００100 μm.

As described above, in the present invention, when a mixture of a polyolefin resin or a mixture of the same with another thermoplastic resin having a low softening point and a colored organic fiber is subjected to heat molding, a low temperature is obtained at the end of the heat molding. It is characterized by utilizing the phenomenon that the softening point component is cast on the surface side to form a transparent surface layer.However, the resulting molded product has a polyolefin-based resin and a colored organic material at the center in the thickness direction. It is unique in that it has a color reinforcement layer consisting of a homogeneous mixture with fibers, and has a three-layer structure consisting essentially of a polyolefin resin or other transparent resin layer mainly composed of a thermoplastic resin with a low softening point, in the surface layer portion. It has a simple composite structure and can be said to be a novel composite molded product by itself.

Therefore, the present invention is not limited to those obtained by the heat molding method described later in detail, but all those having the same layer structure are considered to be included in the technical scope of the present invention. Should.

The colored organic fiber used in the present invention is a component that functions as a coloring component and also functions as a reinforcing material for improving the low-temperature impact resistance. Among the fibers, polyester fibers are most suitable. By the way, among general purpose synthetic fibers,
There is a concern that the vinylon fiber has a slightly poor heat resistance and may cause yellowing under molding temperature conditions, or the effect of improving the low-temperature impact resistance may be insufficient due to thermal degradation. Although the heat resistance of the polyamide fiber is good, the polyamide fiber may be yellowed depending on the heat molding conditions and adversely affect the colored state. Polyolefin fibers have good heat resistance, but
Because the melting temperature is close to the matrix resin, depending on the heat molding temperature, the fibers may also melt,
Since the allowable range of the molding temperature is very narrow, it is difficult to control the temperature during processing.

On the other hand, polyester fibers maintain sufficient heat resistance in the melting temperature range of ordinary polyolefin resins such as polypropylene resins, do not cause discoloration or thermal deterioration, and are within the allowable range of heat molding conditions. This is because wide and stable molding processability can be easily obtained. Particularly preferred among the polyester fibers are polyethylene terephthalate (PET) fibers, polyethylene naphthalate (PEN) fibers, and copolymer fibers thereof, which have good heat resistance and are easily colored.

The preferred fiber diameter of the organic fibers is 0.5 to
100 μm, more preferably in the range of 1 to 50 μm, the fiber length is 0.5 to 50 mm, more preferably 2 to 24 mm
In the case of short fibers having a fiber length of less than 0.5 mm, the impact resistance, in particular, the effect of improving the impact resistance in a low temperature range tends to be inadequate, while if it is excessively longer than 50 mm, the molten polyolefin resin and , The fluidity in the mixed state is deteriorated, the uniform dispersion in the polyolefin resin becomes difficult, and it becomes difficult to obtain a uniform molded article.

The compounding amount of the colored organic fibers in the total amount of the molded article is preferably in the range of 3 to 40% by mass, and more preferably 3% by mass.
If it is less than 40%, the effect of improving the low-temperature impact resistance expected from the colored fiber cannot be effectively exerted. On the other hand, if it is more than 40% by mass, the flowability at the time of melting the polyolefin resin as a molding material becomes poor. In addition to the tendency that poor molding defects due to insufficient ductility tend to occur, a part of the colored fibers easily emerges on the surface, and the color and the surface gloss may be reduced. In view of these points, the blending amount of the colored organic fiber is more preferably in the range of 5 to 35% by mass, and still more preferably 10 to 30% by mass.

The most common optic nerve stimulating substance used for modifying the organic fibers is a coloring material (pigment, dye, etc.). In addition, the metallic material is brilliant due to a reflecting material such as metal particles or metal flakes. It is also possible to give a feeling, to give a fluorescent color by using a fluorescent material, or to give a deeper color by adding a phosphorescent material. Most commonly, these optic nerve stimulating substances are kneaded in an organic fiber material and contained in the fiber.However, for example, it should be attached to the fiber surface by physical / chemical plating. Is also possible.

It is, of course, possible to use monochromatic ones of these colored organic fibers.
It is also possible to realize an arbitrary pattern such as a marble pattern by using organic fibers colored more than the color or by mixing and using organic fibers colored different colors.

On the other hand, examples of the polyolefin resin used as the matrix resin include homo- or copolymers (random or block copolymers) such as ethylene, propylene, and butene. Particularly preferred from the viewpoint of melt fluidity at the time of heat molding is a polypropylene homopolymer, or propylene and ethylene, butene-1, hexene-.
1, α-olefins such as octene-1 and copolymers thereof (random or block copolymers).

In the selection of the polyolefin resin, an appropriate MFR is used so as to exhibit sufficient fluidity when heated and melted in a mixed state with a colored organic fiber during heat molding.
(Melt flow ratio) is preferably used. Preferably, the MFR under the condition of 230 ° C. × 2.16 Kgf is 10 g / 10 min to 200 g / 10 min, more preferably 30 g / 10 min. It is desirable to use one with 150 g / 10 min, more preferably 40 g / 10 min to 100 g / 10 min. By the way, if the MFR is too low, the moldability is deteriorated due to insufficient fluidity at the time of heat molding, which causes a molding process defect. Conversely, if the MFR is too high, the strength as a matrix resin is insufficient. It becomes difficult to obtain a molded product having strength characteristics.

The polyolefin resin has a molecular weight of 50,000 to facilitate formation of a transparent surface layer by casting a low molecular weight material at the end of heat molding as described above.
It is desirable to use one containing 5 to 40% by mass, more preferably about 10 to 30% by mass of a low molecular weight substance of 0 or less.

When a thermoplastic resin other than the polyolefin resin is used as the resin constituting the surface layer, the selection criterion is that the resin has compatibility with the polyolefin resin and has a lower softening property than the polyolefin resin. At the end, the melt-casting property is maintained to the end, and the softening point is at least about 10 ° C. or more, more preferably 1 or more than that of the polyolefin-based resin, so that it can be cast and solidified on the surface layer at the end of heat molding.
It is desirable to use one that is lower by 5 ° C. or more. However,
If the softening point is too low, the surface layer becomes insufficient in strength and lacks scratch resistance. Therefore, it is preferable to use an absolute value of the softening point of 100 ° C or higher, more preferably 105 ° C or higher. . The type of the thermoplastic resin is not particularly limited as long as it satisfies the selection criteria described above, but particularly preferred in combination with the polyolefin-based resin are polyolefin-based random copolymers such as polypropylene-ethylene, ethylene- Examples include vinyl acetate copolymers and chlorinated polyethylene resins.
The preferred blending amount of these other thermoplastic resins is in the range of 5 to 40% by mass, more preferably 10 to 30% by mass, based on the total matrix resin. 5 which is preferable as a smooth surface layer
It is possible to easily obtain a thickness of 得 る 100 μm.

It is also extremely possible to use a small amount of a modified polyolefin, which has been subjected to a modification treatment to enhance the affinity with the colored organic resin used in combination therewith and promote the dispersion of the fiber, with the polyolefin resin. Effective modified polyolefins are exemplified by modified polyolefins modified with various modifiers such as oxazoline and unsaturated carboxylic acids (or their derivatives). Examples of the unsaturated carboxylic acids and derivatives thereof used for these modifications include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, and the like, and acid esters and anhydrides thereof. Is maleic anhydride or glycidyl methacrylate.

The modified polyolefin is preferably used in an amount of 0.1 to 15% by mass, more preferably 0.2 to 12% by mass, and still more preferably 0.5 to 10% by mass based on the polyolefin resin. is there.

The above-mentioned polyolefin resin may contain a small amount of an antioxidant, an antistatic agent, a light stabilizer, an ultraviolet absorber or the like as long as the transparency and the fluidity during heating are not impaired. If necessary, those colored with a dye can be used as long as the transparency is not impaired. However, the use of a coloring material that impairs transparency, such as a coloring pigment, should be avoided.

As described above, in the present invention, a transparent coating layer consisting essentially of only a resin layer is formed on a surface layer portion by utilizing the casting of a low softening point component at the end of cooling and solidification in heat molding to the surface layer side. However, in order to perform such a final casting more reliably, it is necessary to set the mold temperature at the time of heat molding to be higher to facilitate the casting of the low softening point component. desirable. Since the temperature of the mold also varies depending on the softening temperature of the polyolefin resin to be used and the other thermoplastic resin used in combination with the resin, it cannot be determined uniformly, but the use of the polyolefin resin is essential. The preferred standard mold temperature in the present invention is in the range of 60 to 95 ° C, more preferably 65 to 80 ° C, and the mold temperature is lower than about 60 ° C at a low softening point component at the end of solidification. The casting does not occur sufficiently, the formation of the transparent resin layer becomes insufficient, and the colored fibers easily float to the surface layer portion, and the deep surface appearance intended in the present invention cannot be obtained. On the other hand, when the mold temperature exceeds 95 ° C. and becomes excessively high, the solidification of the entire molded body is slowed down, and in particular, the solidification of the surface layer takes a long time, and not only does the productivity significantly decrease, Depending on the difference in the thickness of the product, there is a possibility that a large undesired portion is formed in a part of the molded product and a pocked pattern is formed.

The composite resin molded product of the present invention thus obtained is reinforced only at the central portion with colored organic fibers, and the surface layer side is made of a transparent polyolefin resin, or the transparent coating layer mainly composed of the other thermoplastic resin is used. While being formed, the center side layer containing the colored organic fiber is provided with excellent low-temperature impact resistance, and the colored organic fiber layer on the center side is covered by the transparent coating layer on the surface side to give a deep color, It becomes a resin molded product with extremely excellent aesthetic feeling.

Further, according to the present invention, not only coloring by so-called coloring, but also giving a fluorescent color or a metallic color by changing the type of the visual nerve stimulating substance, or giving a unique appearance having a luminous property can be performed. It is possible and gives a molded article with excellent appearance characteristics combined with excellent surface gloss.
Therefore, this composite resin molded product is used for, for example, parts of home appliances such as air conditioners, refrigerators, vacuum cleaners, desk lamps, electronic devices such as computers, monitors, and mobile phones, parts of light electric devices, office base materials such as office desks and cabinets, and the like. It can be widely and effectively used for various parts that require aesthetic design, such as furniture, buckets, washbasins, pencil cases, letter cases, and other household goods and stationery.

According to the present invention, in addition to molding into an arbitrary shape by injection molding or the like, the sheet is processed into a sheet shape by, for example, a melt extrusion method, and then subjected to secondary processing into an arbitrary shape by heating and pressure molding. Or can be laminated with other materials, so that its application range is extremely wide.

[0045]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, and the present invention is not limited thereto. Modifications can be made and implemented, all of which are included in the technical scope of the present invention.

Example 1 A density of 0.91 g / cm ³ , MFR (230 ° C., 2.16 k
gf) is 60 g / 10 min, and the melting point is 165 ° C. Homopolypropylene resin (a component having a molecular weight of 50,000 or less according to the GPC method is 15% by mass, and the others are high-molecular-weight substances having a higher molecular weight).
0 parts by mass of a maleic anhydride-modified polypropylene resin [“UMEX 1001” manufactured by Sanyo Chemical Industries, Ltd., acid value 6 mgKOH / g, density 0.95 g / cm ³ , molecular weight 4
000 (weight average molecular weight by GPC method)] A resin pellet blended with 3 parts by mass is used as a matrix resin, and this is heated and melted at 230 ° C in a molten resin bath, and polyethylene terephthalate fiber (red melting point: 255 ℃, fiber diameter 15μm · 300 rovings, strength 8g / denier) impregnated by passing while twisting (impregnation time is about 5 seconds), withdrawn, cooled and solidified, then cut into 8mm length and colored Long fiber pellets having a diameter of 3 mm and a length of 8 mm containing 30% by mass of polyester fibers were produced.

The long fiber pellets were mixed with the same polypropylene resin pellets used in the production of the above-mentioned pellets so that the polyester fiber content of the molded product became 30% by mass, 15% by mass and 5% by mass. And an injection molding machine (trade name “JS manufactured by Nippon Steel Works, Ltd.”)
Injection molding was performed at a resin temperature of 200 ° C. and a mold temperature of 70 ° C. according to “WJ200SA”).

The obtained molded product has a total thickness of 3 mm.
In the surface layer, a transparent coating layer made of a polypropylene-based resin is formed, the thickness of the surface layer measured by SEM observation is about 20 μm, and 10 portions of the surface layer are scraped off to reduce the molecular weight by GPC. Upon measurement, the molecular weight was about 40,000.

The physical properties of the obtained injection molded product were evaluated by the following methods, and the results shown in Table 1 were obtained. Gloss: Suga tester Handy gloss meter, measurement angle 60 degrees Visual judgment: The surface of the molded product is visually observed with the naked eye, and the organic fiber that does not float up to the surface is ○, and the organic fiber even partially rises The three-point bending test: conforming to ASTM D790 Izod impact value: conforming to ASTM D256.

Example 2 A density of 0.91 g / cm ³ , MFR (230 ° C., 2.16 k
gf) is 45 g / 10 min, and the melting point is about 165 ° C. Homopolypropylene resin (9% by mass of a component having a molecular weight of 50,000 or less according to the GPC method;
MFR (230 ° C, 2.16 kgf) is 30 parts by mass
g / 10 minutes, 10 parts by mass of an ethylene-propylene random copolymer resin having a melting point of about 150 ° C., a maleic anhydride-modified polypropylene resin [“UMEX 1001” manufactured by Sanyo Chemical Industries, Ltd., acid value 6 mgKOH / g, density 0.95 g. /
cm ³ , molecular weight 40,000 (weight average molecular weight by GPC method)] A resin pellet blended with 3 parts by mass was used as a matrix resin, and this was applied to a molten resin bath heated and melted at 230 ° C in Example 1 above. Polyethylene terephthalate fiber (melting point 25
5 ° C, fiber diameter 15μm, 300 rovings, strength 8
g / denier) while impregnating by twisting (impregnation time is about 5 seconds), withdrawn, cooled and solidified, cut to a length of 8 mm, a diameter of 3 mm containing 30% by mass of colored polyester fiber, and a length of 3 mm. 8 mm long fiber pellets were produced.

This long fiber pellet is mixed with the same polypropylene resin pellet used in the production of the pellet so that the polyester fiber content of the molded product is 15% by mass, and the mixed pellet is used. Example 1 above
Injection molding was performed in the same manner as described above.

The obtained molded product had a total thickness of 3 mm.
In the surface layer, a transparent coating layer is formed, and the SEM
The thickness of the surface layer confirmed by observation was about 25 μm. Ten parts of the surface layer were scraped off and analyzed for their components. As a result, the main component was an ethylene-propylene random copolymer. This is evaluated and tested in the same manner as above,
The results are shown in Table 1.

Example 3 The same long fiber pellets as used in Example 1 were blended with the above homopolypropylene resin so that the organic fiber content in the total amount was 10% by mass, and this blend was extruded. It was extruded through a T-die into a sheet having a thickness of about 2 mm.

The obtained sheet was heated and melted, and compression molded using a mold at 80 ° C. to obtain a flat molded product. This molded product has a total thickness of 2 mm, and a transparent coating layer made of a polypropylene resin is formed on the surface layer.
The thickness of the surface layer portion measured by M observation was about 15 μm, and the average molecular weight was measured by shaving 10 portions of the surface layer portion and was confirmed to be about 40,000.

An evaluation test was carried out in the same manner as described above, and the results shown in Table 1 were obtained.

Comparative Example 1 The same polypropylene resin as used in Example 1 was used,
A colored dye was produced by adding a red dye, and injection molding was performed in the same manner as in Example 1 using only the colored pellet, and the physical properties of the molded product were evaluated in the same manner.
Table 1 shows the results.

Comparative Example 2 Colored pellets were prepared by adding a red dye to the ethylene-propylene copolymer resin used in Example 2 and injection molding was performed in the same manner as in Example 2 using only the pellets. An evaluation test was performed in the same manner. Table 1 shows the results.

Comparative Example 3 An injection-molded article having a colored fiber content of 10% by mass was produced in exactly the same manner as in Example 1 except that the mold temperature was lowered to 40 ° C. This molded product, because the mold temperature at the time of injection molding is too low, probably because the low molecular weight component in the polypropylene resin did not sufficiently cast at the end of solidification, the transparent resin layer is hardly formed on the surface, In addition, some of the colored fibers were exposed on the surface, and the gloss and appearance were poor. Table 1 shows the performance evaluation results of the molded article.

Comparative Example 4 Density: 0.91 g / cm ³ , MFR (230 ° C., 2.16 k
gf) 10 g / 10 min, melting point: 165 ° C. Homopropylene resin (4% by mass for components having a molecular weight of 50,000 or less according to the GPC method, other high molecular weight materials) A molten resin bath heated and melted at 230 ° C. A polyethylene terephthalate fiber (melting point: 255 ° C., fiber diameter: 15 μm) colored red
Impregnation by impregnating 300 rovings with a strength of 8 g / denier while twisting (impregnation time is about 5
Sec), pulled out, cooled and solidified, cut into 8 mm length, 3 m in diameter containing 30% by mass of colored polyester fiber
m, 8 mm long fiber pellets were produced.

This long fiber pellet is mixed with the same polypropylene resin pellet used in the production of the pellet so that the polyester fiber content of the molded article becomes 15% by mass, and the mixed pellet is used. Injection molding was performed at a resin temperature of 200 ° C. and a mold temperature of 70 ° C. using an injection molding machine (trade name “JSW J200SA” manufactured by Japan Steel Works, Ltd.).

The obtained molded product has a total thickness of 3 mm.
In the surface layer, a transparent coating layer is hardly formed,
Some of the colored fibers were exposed to the surface layer, and a fluffy appearance was not obtained. Also the performance evaluation results of the molded product,
The results are shown in Table 1.

[0062]

[Table 1]

[0063]

The present invention is constituted as described above, and has a colored layer containing colored organic fibers on the center side in the thickness direction and a coating layer made of only a transparent resin containing no colored fibers on the surface side. By forming, it provides a composite resin molded product which is deep in color, has excellent aesthetics, and also has excellent low-temperature impact resistance, and has such excellent properties according to the production method of the present invention. Thus, the composite resin molded article can be efficiently manufactured by a simple method.

Continued on the front page (72) Inventor Teruhiko Yamada 4-7-23 Meieki Station, Nakamura-ku, Nagoya F-Term in Toyota Tsusho Corporation (reference) 4F100 AK01B AK03A AK03B AK07 AK41A AK42 AL05B AL07 BA02 DG01A EH362 EJ422 GB16 GB48 GB71 GB81 HB00A JA04B JA07B JA20B JB16B JJ04 JK10 JL10A JN01B JN06A JN13A JN21 YY00A YY00B 4F206 AA00 AA03A AB01 AB12 AB25 AF00 AG03 AH33 AH49 AH51 AH53 AR06 JA03 JB11 JB22 JF01F

Claims (15)

[Claims] 1. A composite resin layer containing an organic fiber modified with a visual nerve stimulating substance and a polyolefin resin, and the organic fiber is uniformly dispersed in the polyolefin resin on the center side in the thickness direction of the resin layer. It is composed of a composite layer, and the surface layer side is a thermoplastic resin of the same or different kind as the polyolefin-based resin, and is characterized by being made of a substantially transparent thermoplastic resin having a softening point lower than that of the polyolefin-based resin. High-visibility composite resin molded product with excellent low-temperature impact resistance. 2. The composite resin molded article according to claim 1, wherein the optic nerve stimulating substance is at least one selected from the group consisting of a coloring substance, a reflective substance, a fluorescent substance, and a luminous substance. 3. The composite resin molded article according to claim 1, wherein the organic fiber is a polyester fiber. 4. The content of the organic fiber is 3 to 40% by mass.
The composite resin molded product according to any one of claims 1 to 3, wherein 5. The composite molded article according to claim 1, wherein said surface layer has a thickness of 5 to 100 μm. 6. The thermoplastic resin is a polyolefin resin, and has a MFR of 15 ° C. at 230 ° C. and 2.16 kgf of a molten mixture with the polyolefin resin of the central layer.
The composite resin molded product according to any one of claims 1 to 5, which has a g / 10 minute to 200 g / 10 minute. 7. The composite resin molded article according to claim 1, wherein the thermoplastic resin of the surface layer is mainly composed of a polyolefin resin having a molecular weight of 50,000 or less by GPC. 8. The composite according to claim 1, wherein the thermoplastic resin on the surface layer has a softening point lower than the softening point of the polyolefin resin in the central layer by 10 ° C. or more. Resin molded products. 9. A mixture of an organic fiber modified with an optic nerve stimulating substance and a polyolefin-based resin is heated and molded at a temperature lower than the melting point of the organic fiber and higher than the melting point of the polyolefin-based resin. Forming a transparent coating layer made of the polyolefin resin on the surface layer by melting and flowing the polyolefin resin to the inner wall surface of the mold, thereby forming a high-visibility composite resin excellent in low-temperature impact resistance. Product manufacturing method. 10. The polyolefin-based resin is a GPC
The method according to claim 9, which comprises 5 to 40% by mass of a polyolefin resin having a molecular weight of 50,000 or less. 11. A mixture of an organic fiber modified by an optic nerve stimulating substance, a polyolefin-based resin, and a thermoplastic resin having a lower softening point than the polyolefin-based resin,
Heat molding at a temperature lower than the melting point of the organic fiber and higher than the melting point of the polyolefin resin and the thermoplastic resin,
A high-visuality excellent in low-temperature impact resistance, characterized in that a transparent coating layer made of the thermoplastic resin is formed on the surface layer side by melting and flowing the thermoplastic resin toward the inner wall surface of the mold in the mold. For producing composite resin molded products. 12. The method according to claim 11, wherein the thermoplastic resin has a softening point lower than that of the polyolefin-based resin by 10 ° C. or more. 13. The optic nerve stimulating substance according to claim 9, wherein the optic nerve stimulating substance is at least one selected from the group consisting of a coloring substance, a reflective substance, a fluorescent substance, and a luminous substance. Manufacturing method. 14. The method according to claim 9, wherein the organic fiber is a polyester fiber. 15. The method according to claim 9, wherein the content of the organic fiber is 3 to 40% by mass.