JP2003096312A - Composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite material which can give a molded article having good appearance and generating neither a flow mark and roughness on the surface nor dark brown coloration and discoloration caused by burning on the molded article obtained by injection molding and extrusion molding, and to provide the molded article. SOLUTION: The composite material and the molded article comprise a polyolefin wax in a composite material which contains a paper component obtained by heat-kneading a ground material of a laminate paper sheet obtained by grinding the laminate paper sheet having a synthetic resin layer on either the one side or the both sides of the paper sheet with a thermoplastic resin. The polyolefin wax is a modified polyolefin wax having from not less than 1,000 to not more than 20,000 of the average molecular weight. Further, the polyolefin wax is a maleic acid-modified polyolefin wax.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material obtained by heating and kneading a crushed laminated paper obtained by crushing a laminated paper having a synthetic resin layer on one side or both sides of the paper and a thermoplastic resin. In addition to having good moldability, a molded product using the composite material does not have a wavy flow pattern (hereinafter referred to as a flow mark), and particularly has a good appearance at the time of coloring. The present invention relates to a composite material which is free from burrs and which can shorten the molding cycle time and has good workability.

[0002]

2. Description of the Related Art A composite material obtained by kneading a vegetable fiber mainly containing cellulose in a thermoplastic resin is disclosed in JP-B-52-3613.
4, JP-B-56-9576, JP-B-61-225234
It is described in. However, although wood flour, rice husks, waste paper, etc. are mentioned as plant fibers described in any of the publications, laminated paper in which a synthetic resin layer is provided on one or both sides of the paper is not described. Laminated paper is described as a raw material in JP-A-10-13824.
There is only one. However, when an injection molding method or an extrusion molding method is used to produce a molded product from the paper-containing resin pellets described in the publication, the resin temperature is increased due to poor flowability of the resin during molding. The flowability of the resin had to be improved, and unless the temperature of the resin was adjusted properly, only a molded product in which the paper component was burnt and the whole color was changed to brown was obtained. In addition, the fluidity of the resin is limited.

Probably because of its fluidity limit, the composite materials described in any of the publications have flow marks or surface roughness on the surface of the molded product during injection molding. The flow mark becomes particularly prominent when the molded product is colored, which makes it less valuable as a product.

On the other hand, there is also a method of using a thermoplastic resin having a high fluidity in order to increase the fluidity of the composite material so as not to generate flow marks, but this causes remarkable burrs in the molded product, and also It becomes a low value product.

[0005]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to prevent the moldings produced by injection molding and extrusion from being browned or discolored due to the occurrence of charring, and not causing flow marks or surface roughness on the surface. To provide a composite material and a molded product capable of producing a molded product having a good appearance.

[0006]

The present inventors have made the following inventions as a result of earnest research to solve the above problems.

That is, in a composite material containing a paper component obtained by heating and kneading a crushed laminated paper obtained by crushing laminated paper having a synthetic resin layer provided on one or both sides of the paper and a thermoplastic resin, The invention of a composite material is characterized in that the composite material contains a polyolefin wax.

The polyolefin wax has an average molecular weight of 1
It is an invention of the above composite material, which is a modified polyolefin wax of 000 or more and 20,000 or less.

The modified polyolefin wax is a maleic acid-modified polyolefin wax, which is an invention of the above composite material.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A composite material comprising a pulverized laminated paper of the present invention and a thermoplastic resin is a pulverized laminated paper obtained by pulverizing a laminated paper having a synthetic resin layer on one or both sides of the paper and It is a composite material obtained by heating and kneading a plastic resin.

The polyolefin wax used in the present invention is not particularly limited, and general polymerization type, modified type, decomposition type and the like are generally used. As the general polymerization type, there are a high-density type and a low-density type, and as the modified type, there is a low-molecular-weight nonpolar polyolefin wax in which the terminal is substituted with an acid group or a hydroxyl group. As the acid group, carboxylic acid or its anhydride, maleic acid or its anhydride, etc. can be used. Preferably, the average molecular weight is 1000 or more and 200 or more.
A modified polyolefin wax of 00 or less can be used.

A flow mark does not occur on the surface of a molded product made of the composite material containing the paper component containing the polyolefin wax of the present invention, and a molded product having a good appearance can be obtained. Further, it has been found that when the polyolefin wax is a modified polyolefin wax having an average molecular weight of 1,000 or more and 20,000 or less, burrs, which are likely to occur in a molded product, hardly occur.

Further, by using maleic acid-modified polyolefin wax as the modified polyolefin wax, the fluidity of the composite material at the time of molding becomes good and the injection pressure is lowered, resulting in shortening of molding cycle or load of molding machine. It turned out that it can be reduced.

The preferred content of the polyolefin wax in the composite material is 1 to 30 parts, based on 100 parts of the total composite material. If the content of the polyolefin wax is less than 1 part, the effect of the present invention is difficult to obtain,
Even if it is more than the amount, the effect will be saturated, which is not economically preferable.

The laminated paper is not particularly limited as long as a synthetic resin layer, a so-called laminated layer, is provided on one surface or both surfaces of general paper such as high-quality paper and medium-quality paper. Moreover, the thickness of the laminate layer is not particularly limited. The synthetic resin forming the synthetic resin layer is not particularly limited, such as polyethylene and polypropylene, but a synthetic resin layer formed of a polyolefin resin is preferable.

The basis weight and thickness of the laminated paper are not particularly limited. Specifically, laminar paper used for photographic paper base paper, kraft wrapping paper, magazine cover, etc. is used, but preferably, waste material generated during the production of the laminated paper, or the production of these laminated papers, or It is preferable to use trimming loss that occurs during processing because it has an effect of reducing waste.

The paper constituting the laminated paper used in the present invention is mainly composed of wood pulp and pigment.
Wood pulp includes chemical pulp such as LBKP and NBKP, GP, PGW, RMP, TMP, CTMP, CM
P, CGP and other mechanical pulps, DIP and other waste paper pulps and other pulps are included, and if necessary, conventionally known pigments, binders and sizing agents, fixing agents, yield improving agents, cationizing agents, paper strengthening agents, etc. The support can be manufactured by mixing various additives with one or more kinds and using various devices such as a fourdrinier paper machine, a cylinder paper machine, and a twin wire paper machine, and paper can be made acidic, neutral or alkaline.

The content of the pulverized laminated paper in the composite material of the present invention is preferably adjusted so that the paper component constituting the laminated paper is 10 to 85% by mass in the composite material. By setting the paper content to 10 to 85% by mass, it is possible to reduce the amount of heat generated when the composite material and the molded product of the present invention are incinerated, and it is effective without damaging the incinerator. If the paper content is less than 10% by mass, the amount of heat generated during incineration increases and the meltdown of the thermoplastic resin becomes visible during incineration, again damaging the incinerator. Further, if the paper content is more than 85% by mass, molding becomes difficult, which causes a problem in practical use.

The thermoplastic resin used in the composite material of the present invention is not particularly limited and a general one can be used. Examples of the thermoplastic resin include the following substances. High density polyethylene, low density polyethylene,
Polyethylene such as medium density polyethylene, linear low density polyethylene and metallocene polyethylene; polypropylene such as isotactic, syndiotactic and atactic polypropylene, a mixture thereof, polypropylene such as random copolymer or block copolymer with ethylene; Other poly-3-methylpentene-1, polystyrene, impact-resistant polystyrene, styrene copolymer, polyvinyl chloride, acrylonitrile-butadiene-styrene resin (ABS resin), styrene-acrylonitrile resin (AS resin),
Polyamide, polyacetal, polycarbonate, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), modified polyphenylene ether,
The thermoplastic elastomer and the like can be used alone or in combination.

The means for producing the pulverized laminate paper used in the present invention is not particularly limited, and a general pulverizer can be used. Examples of the crusher include a ball mill type, an impact crush type, a cutter type, a pin mill type, a stone mill type, a friction crush type and a crusher type. It is preferable to use the one crushed in two steps of coarse pulverization and fine pulverization, because the kneadability with the thermoplastic resin is good and the fluidity at the time of molding is good.

The heating and kneading for obtaining the composite material of the present invention means a step of uniformly dispersing a pulverized product of laminated paper, a thermoplastic resin, a polyolefin wax and various additives, specifically, by heating. The process of uniformly kneading various materials in a molten or semi-molten state with a mixer or a screw. There is no particular limitation on the heating temperature, even if the heating temperature is set below the softening temperature of the material,
By increasing the shearing force applied to the material, shearing heat insulation occurs, and as a result, a composite material that can be uniformly kneaded can be obtained. However, since the composite material of the present invention contains a pulverized product of laminated paper, the heating temperature must be limited to a range in which the pulverized product of laminated paper does not burn by heat. At that time, it is preferable to heat and knead the material to be heated within a range where the temperature can be limited to 190 ° C. or lower.

In order to obtain the composite material of the present invention, a pulverized product of laminated paper, a thermoplastic resin and a polyolefin wax are weighed in a specified amount and then melt-mixed with a high-speed stirrer such as a Henschel mixer to granulate. Good, or you can knead with a batch type kneader such as a Banbury mixer,
A single-screw or twin-screw extruder is preferably used to improve the kneading property, and more preferably a twin-screw extruder is used because the kneading property is further improved. Kneading with an extruder
During granulation, the strand discharged from the die head may be hot-cut, or may be drawn into a water tank for cooling and then cut to a desired length with a pelletizer. Also, when kneading and granulating with an extruder, pulverized laminate paper, thermoplastic resin and modified polyolefin wax may be mixed in advance with a mixer, and the three members may be charged into the extruder at the same time. After feeding into the extruder, the remaining material may be fed into the extruder using a side feeder.

Various additives may be added to the composite material of the present invention as long as the object of the present invention is not impaired. As additives, inorganic pigments, organic pigments, colorants such as dyes,
Examples include flame retardants, antistatic agents, antioxidants, ultraviolet absorbers, lubricants, cross-linking agents, conductive agents, antibacterial / antifungal agents, plasticizers, silicones, compatibilizers, reinforcing agents, and fillers.

A molded product can be produced using the composite material of the present invention. As a means for producing a molded product, various extrusion molding methods such as an injection molding method, a T-die extrusion molding method, a modified molding method and an inflation molding method, and a compression molding method are preferably used.

Since the composite material of the present invention is composed of pulverized laminated paper, thermoplastic resin and polyolefin wax, it does not damage the incinerator during incineration. Further, since the polyolefin wax is contained, a molded product having a good appearance can be obtained without causing flow marks or surface roughness on the surface of the molded product.

Further, when the polyolefin wax is a modified polyolefin wax having an average molecular weight of 1,000 or more and 20,000 or less, burrs do not occur in the molded product. Moreover, by using a maleic acid-modified polyolefin wax as the modified polyolefin wax, the molding cycle time during injection molding can be shortened.

[0027]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. Further, in Examples and Comparative Examples, “part” and “%” are
Unless otherwise specified, parts by mass and% by mass are shown.

Example 1 Kraft wrapping paper having a polypropylene laminated layer on one side (20% by mass of the laminated layer) was prepared as laminated paper, and a cutter type crusher (Turbo Cutter C- manufactured by Turbo Kogyo Co., Ltd.) was used. 300 3 mm mesh was mounted) to grind into a scale of about 3 mm to obtain a crushed laminated paper. Linear low-density polyethylene (NUCG-5361, Nippon Unicar Co., Ltd.) as a thermoplastic resin
Is a general polymerization type polyethylene wax (High Wax 100 manufactured by Mitsui Chemicals, Inc.)
P average molecular weight 900) was prepared, weighed in the following blending ratio, charged into a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) and granulated to obtain a composite material of the present invention. Laminated paper crushed product 64 parts Thermoplastic resin 31 parts Polyolefin wax 5 parts

Example 2 A composite material of the present invention was obtained in the same manner as in Example 1 except that the polyolefin wax was changed to a general polymerization type polypropylene wax having an average molecular weight of 30,000 (Umex 1010 manufactured by Sanyo Chemical Industry Co., Ltd.).

Example 3 A composite material of the present invention was obtained in the same manner as in Example 1 except that the modified polypropylene wax (Umex 100TS manufactured by Sanyo Chemical Industry Co., Ltd.) having an average molecular weight of 10,000 was used instead of the polyolefin wax.

Example 4 A composite material of the present invention was obtained in the same manner as in Example 1 except that the polyolefin wax was changed to a special monomer modified type wax having an average molecular weight of 1200 (High Wax 1120H manufactured by Mitsui Chemicals, Inc.). .

Example 5 A composite material of the present invention was obtained in the same manner as in Example 1 except that the polyolefin wax was changed to an oxidation-modified polypropylene wax having an average molecular weight of 20,000 (Umex 1003 manufactured by Sanyo Kasei Co., Ltd.).

Example 6 A composite material of the present invention was obtained in the same manner as in Example 1 except that the polyolefin wax was changed to a maleic acid-modified polyethylene wax having an average molecular weight of 1500 (High Wax 1105A manufactured by Mitsui Chemicals, Inc.).

Example 7 A composite of the present invention was prepared in the same manner as in Example 6 except that the crushed laminated paper was changed to a crushed laminated paper of photographic polyethylene resin coated paper having polyethylene laminated layers on both sides of the paper. Got the material.

Comparative Example 1 Kraft wrapping paper having a polypropylene laminated layer provided on one side of the paper was prepared as laminated paper (laminating layer mass ratio 20% by mass), and a cutter type crusher (Turbo Cutter C- manufactured by Turbo Kogyo Co., Ltd.) was prepared. 300 3 mm mesh was mounted) to grind into a scale of about 3 mm to obtain a crushed laminated paper. As the thermoplastic resin, a linear low-density polyethylene (Nippon Unicar Co., Ltd. NUCG-5361) was prepared, weighed in the following mixing ratio, and then charged into a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) to granulate, A composite material containing paper was obtained. Laminated paper crushed product 64 parts Thermoplastic resin 36 parts

Comparative Example 2 Fine paper (laminate layer mass ratio 0 mass%) was used as a cutter type crusher (manufactured by Turbo Kogyo Co., Ltd., Turbo Cutter C-3).
(3) with a 3 mm mesh) and crushed into scales of about 3 mm to obtain a fine paper crushed product. As a thermoplastic resin, linear low-density polyethylene (Nippon Unicar Co., Ltd. NUCG
As a polyolefin wax, a general polymerization type polyethylene wax (Mitsui Chemicals High Wax 100P average molecular weight 900) was prepared, weighed at the following compounding ratio, and then a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.)
And granulated to obtain a composite material containing paper. Fine paper pulverized product 51 parts Thermoplastic resin 44 parts Polyolefin wax 5 parts

<Test Method> 1) Evaluation of Appearance of Molded Articles 1 The composite materials obtained in Examples and Comparative Examples were dried for 3 hours in a dryer set at 90 ° C., and then an injection molding machine (Japan Steel Works, Ltd.) Made of J55ELIII) with 2mm thick plate (8
20 mm (0 mm × 50 mm) was molded, the appearance was visually evaluated, and the number of sheets having a good appearance without generation of flow marks and surface roughness was taken as the evaluation result. The larger the number, the better.

2) Appearance evaluation 2 of molded product Same as the external appearance evaluation 1 of molded product except that a black masterbatch (pigment content 20%) was mixed in 0.5% by weight ratio when the molded product was prepared. 2mm thick plate (80
mm × 50 mm) was prepared and evaluated in the same manner as the appearance evaluation 1 of the molded product.

3) Burr Molded Product The appearance of burrs on the 2 mm-thick plate produced in Appearance Evaluation 1 was observed, and the number of plates having no burrs and having a good appearance was used as the evaluation result. The larger the number, the better.

4) Molding cycle The evaluation result was the average value of the molding cycle time when a 2 mm-thick plate was prepared in the appearance evaluation 1 and 2 of the molded product. The smaller the value, the shorter the molding cycle time, which is preferable.

[0041]

[Table 1]

Evaluation: As is clear from Table 1, the composite material of the present invention has a good appearance of the molded product. In Comparative Example 2 in which the crushed fine paper is used in place of the crushed laminated paper, the flow mark is not noticeable and the appearance is good in the molded product which is not particularly colored, but when colored black, the flow mark becomes noticeable. It was clearly found that the appearance was inferior to that of the molded product using the composite material.

In the composite material of the present invention, it was found that burrs did not occur at all in the molded product by changing the polyolefin wax to a modified polyolefin wax having an average molecular weight of 1,000 or more and 20,000 or less. Further, it is also clear that the molding cycle time can be shortened by using the maleic acid-modified polyolefin wax as the polyolefin wax.

[0044]

EFFECTS OF THE INVENTION When a molding material is produced by using the composite material of the present invention, it is effective that a molded product having a good appearance can be obtained without generation of flow marks and burrs.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08J 5/00 CER C08L 1/00 CEZ 23/00 C08L 1/00 B29K 23:00 23/00 B09B 3/00 Z / / B29K 23:00 ZAB (72) Inventor Masakazu Kimura 135 Kashiwazaki, Iwatsuki-shi, Saitama F-Term (reference) within Polycol Co., Ltd. (reference) 4D004 AA07 AA12 BA07 CA04 CA14 CA22 CB12 4F071 AA01 AA14 AA71 AA73 AA74 AA78 AA81 AG21 AG28 AG AG34 BB05 BC01 BC03 4F206 AA03 AA50 AM33 AM36 JA07 JF51 JQ81 4J002 AB01Z AH00W BB03X BB03Y BB12X BB13X BB15X BB21Y BC03X BC06X BD03X BN14X BN15X BP02X CF06X CF07X CL00X CH07X CH07X CG00X CH07

Claims (4)

[Claims] 1. A composite material obtained by heating and kneading a pulverized product of a laminated paper obtained by pulverizing a laminated paper having a synthetic resin layer provided on one or both sides of the paper and a thermoplastic resin. A composite material comprising a polyolefin wax. 2. The composite material according to claim 1, wherein the polyolefin wax is a modified polyolefin wax having an average molecular weight of 1,000 or more and 20,000 or less. 3. The composite material according to claim 2, wherein the modified polyolefin wax is a maleic acid modified polyolefin wax. 4. A molded article made of the composite material according to claim 1.