JP2001302808A - Method for producing polyolefin-based resin molded article having grain pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a molded article comprising a wood-based material-containing polyolefin-based resin and having a grain pattern, is which production has been difficult, and to provide a grain pattern- forming pigment master batch used therefor. SOLUTION: This method for producing a polyolefin-based resin molded article having a grain pattern, comprising compounding a wood-based material- containing polyolefin-based resin composition comprising a wood-based material and a polyolefin-based resin with a grain pattern-forming pigment master batch and then molding the mixture, a characterized by using a thermoplastic polyester elastomer having a melting point of 170 to 220 deg.C [measured with a differential scanning calorimeter(DSC) according to JISK 7121] and a melt flow rate of 1 to 50 g/10 min (ASTM D 1238, a load of 2.16 kg, a temperature of 230 deg.C) as a base resin for the grain pattern-forming pigment master batch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a wood-based material-containing polyolefin resin molded article having a wood grain pattern, and a wood grain forming pigment master batch for the polyolefin resin.

[0002]

2. Description of the Related Art Conventionally, a composite material obtained by blending a woody material such as wood flour with a thermoplastic resin has been used for building materials, furniture, daily necessities,
Attempts have been made in various fields to use it for automobile parts, etc., and already vinyl chloride resin containing wood flour and ABS
Resin molded products have been put to practical use and used in large quantities. These attempts are to improve the mechanical strength, such as flexural modulus, by reducing the thermal expansion coefficient by blending a woody material with a thermoplastic resin, and to obtain a molded product that looks and feels like wood. Hereinafter, it will be referred to as a feeling of wood.) This makes it possible to effectively use wood waste, wood fiber, and the like discharged in large quantities from construction waste materials and various wood industries.

However, as the use of composite materials in which a wood-based material is blended with a thermoplastic resin has become widespread, a molded article having not only a woody appearance but also a high designability, that is, a wood grain pattern such as natural wood has been provided. Is being demanded.

[0004] As a molded article having a grain pattern, a molded article made of a vinyl chloride resin or an ABS resin having a grain pattern is known. This is a vinyl chloride resin or A
In the case of BS resin, even if compounds having different degrees of polymerization (molecular weight) are mixed by heating and melting, they are not completely mixed. That is, a predetermined pigment is added to resins having different degrees of polymerization to form a color compound. Are mixed and extruded, and the compounds having different colors are extruded in a streak-like pattern without being mixed with each other. However, in the case of molded products made of polyolefin-based resin, the compounds charged into the hopper of the molding machine are easily mixed even if there is a difference in the degree of polymerization, and the color of each compound becomes a single color with a mixed grain. It could not be granted.

Therefore, in order to impart a grain pattern to a molded article made of a polyolefin resin, it is necessary to feed the grain forming pigment master batch not in the hopper of the molding machine but in the middle of a die. However, it is extremely difficult to control the molten state so that the grain forming pigment masterbatch is in a semi-molten state and does not mix with each other and is extruded in a streak-like pattern. However, there was a problem that it was not possible to form any.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and has a wood grain pattern having a wood grain pattern, which has heretofore been difficult with a method of feeding a wood grain forming pigment master batch from a hopper portion of a molding machine. An object of the present invention is to provide an advantageous method for producing a polyolefin-based resin molded article containing a system material, and a masterbatch for forming a grain of wood used for the method.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above-mentioned object is achieved when a thermoplastic polyester elastomer having a specific melting point and a melt flow rate is used as a base resin of a grain forming pigment masterbatch. The inventors have found what can be achieved, and have reached the present invention.

That is, the present invention relates to a method for producing a polyolefin resin molded article having a grain pattern described below, and a grain forming pigment master batch used for the method. (1) A method for producing a polyolefin-based resin molded article having a wood-grain pattern formed by blending a wood-grain-forming pigment master batch with a wood-based material-containing polyolefin-based resin composition comprising a wood-based material and a polyolefin-based resin, The melting point (measured according to JIS K7121 using a differential scanning calorimeter (DSC)) of 170 to 220 ° C. and the melt flow rate of 1 to 50 g / 10 min (ASTM D1238, load 2. A method for producing a polyolefin resin molded article having a wood grain pattern, comprising using a thermoplastic polyester elastomer having a temperature of 16 kg and a temperature of 230 ° C.). (2) The method for producing a polyolefin resin molded article having a wood grain pattern according to (1), wherein the wood grain forming pigment master batch contains 3 to 70 wt% of the pigment. (3) Wood-based material-containing polyolefin-based resin composition 10
0 part by weight, the grain forming pigment master batch 0.5
The method for producing a polyolefin resin molded article having a grain pattern according to (1) or (2), wherein the molded article is blended with 10 to 10 parts by weight. (4) Melting point (according to JIS according to differential scanning calorimetry (DSC))
Measured according to K7121. ) At 170 to 220 ° C. and a melt flow rate of 1 to 50 g / 10 min (ASTM D
1238, a masterbatch forming pigment for a polyolefin resin, comprising as a base resin a thermoplastic polyester elastomer having a load of 2.16 kg and a temperature of 230 ° C).

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be specifically described below. The polyolefin resin molded article having a wood grain pattern of the present invention is formed by blending a wood grain forming pigment master batch with a wood based material-containing polyolefin resin composition comprising a wood based material and a polyolefin based resin. As the wood-based material-containing polyolefin-based resin composition, any wood-based material mixed with a polyolefin-based resin, which can be molded and used, can be used without any particular limitation. Here, the polyolefin resin is a homopolymer or a copolymer of an α-olefin having 2 to 20 carbon atoms. Examples of the polyolefin resin include, for example, homopolymers of α-olefins such as polyethylene, polypropylene, polybutene, and poly-4-methyl-1-pentene, ethylene-propylene copolymer, and ethylene-α-
Α-olefin copolymers such as olefin copolymers, propylene-α-olefin copolymers, ethylene-vinyl acetate copolymers, ethylene- (meth) acrylic acid alkyl ester copolymers, ethylene- (meth) Acrylic acid copolymers, ionomer resins obtained by neutralizing ethylene- (meth) acrylic acid copolymers with metal ions, and the like. In the present invention, one or more selected from these polyolefin-based resins may be appropriately used. You can choose.

The wood-based material is a substance containing lignocellulose, cellulose or a derivative thereof, and any material conventionally used as a filler for a resin can be used without limitation. For example, wood-based materials obtained from wood-based materials or unused wood-based materials as industrial waste in the wood industry, such as wood powder, sand pulp, and sander powder generated during polishing of particle board, may be mentioned. Those obtained by neutralizing wood acid (lepulinic acid, acetic acid, formic acid, etc.) with urea, sodium carbonate or the like can be used. Further, as the wood-based material, an esterified wood-based material obtained by addition esterifying a polybasic acid anhydride to the above-mentioned wood-based material can also be used. In particular, the esterified wood-based material is preferable because it has an excellent affinity for the polyolefin-based resin as compared with the untreated wood-based material. In addition, as polybasic acid anhydride, for example, maleic anhydride, phthalic anhydride, succinic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, itaconic anhydride,
Adipic anhydride is mentioned, but it is particularly preferred to use maleic anhydride. The ratio of polybasic acid anhydride introduced into the wood-based material by esterification is generally 0.5 to 20 wt%, preferably 1.0 to 1 wt.
0 wt%.

In the polyolefin-based resin composition containing a wood-based material used in the present invention, the mixing ratio of the wood-based material to the polyolefin-based resin is 10 to 70 wt%.
%, And the polyolefin-based resin is preferably blended so as to be 90 to 30 wt%. The mixing ratio of wood-based materials is 1
If it is less than 0 wt%, the woody feeling is poor and the coefficient of linear expansion becomes large. If it exceeds 70 wt%, the heat fluidity is lowered and molding processing becomes difficult, which is not preferable. Furthermore, when the polyolefin resin molded product having a wood grain pattern of the present invention is produced by an extrusion molding method, the melt flow rate (MFR: 190 ° C., 2.16 kg load) at 190 ° C. as the wood-based material-containing polyolefin resin composition is used. ASTM D1
(238-65T) is preferably 0.005 to 1.5 g / 10 min. MFR 0.005g / 1
If it is less than 0 minute, the heat fluidity is too poor to make the molding process difficult, and if it exceeds 1.5 g / 10 minutes, it becomes easy to draw down and it is not only difficult to mold into the desired shape,
It is not preferable because the holding power of the woody material in the resin is insufficient and the surface becomes fuzzy.

As a wood-based material-containing polyolefin resin composition satisfying such conditions, for example, a compound is obtained by heating and kneading a polyolefin resin and an esterified wood-based material in the presence or absence of an organic peroxide. Polyolefin-based resin, wood-based material, and those obtained by compounding by heating and kneading 1 to 10 parts by weight of a modified polyolefin resin with respect to 100 parts by weight of the total thereof, polyolefin-based resin, wood-based material, And a compound obtained by heating and kneading 0.5 to 20% by weight of a polybasic acid anhydride in the presence of an organic peroxide with respect to the wood-based material to form a compound. It is preferable because it can be blended and has excellent heat moldability.
In addition, when manufacturing the wood-based material-containing polyolefin-based resin composition, the heating and kneading may be performed using a device such as a blender, a kneader, a mixing roll, a Banbury mixer, a single-screw or a twin-screw granulation extruder. Can be. The modified polyolefin resin used in the above is a polyolefin resin modified with maleic anhydride, dimethyl maleate, diethyl maleate, acrylic acid, methacrylic acid, tetrahydrophthalic acid, glycidyl methacrylate, hydroxy methacrylate, etc. The amount is 0.1 to 20% by weight.

The polyolefin-based resin composition containing a wood-based material used in the present invention may contain, if necessary, an inorganic filler such as talc, calcium carbonate, mica, or glass fiber, or a polyester or polyamide fiber. Organic fillers, or various additives such as flame retardants, stabilizers, ultraviolet absorbers, antioxidants, plasticizers and lubricants. Further, it is of course possible to incorporate a coloring agent such as a dye or a pigment for the base.

On the other hand, the woodgrain-forming pigment masterbatch comprises a base resin containing a pigment and, if necessary, a dispersant, a flow lubricant, a stabilizer and the like. When forming the composition, the composition becomes a semi-molten state and is dispersed in a streak shape to form a grain pattern. In the present invention, a thermoplastic polyester elastomer having a specific melting point and melt flow rate is used as the base resin of the grain forming pigment masterbatch. The thermoplastic polyester elastomer as referred to in the present invention means a thermoplastic polyester resin having a hard portion and a soft portion in a molecule and exhibiting properties as an elastomer. A copolymer in which the hard component represented by the chemical formula (I) or (II) is composed of an aromatic polyester and the soft component is composed of an aliphatic polyether or an aliphatic polyester can be particularly preferably used.

[0015]

(Equation 1)

In the present invention, the melting point (differential scanning calorimeter (D
SC) according to JIS K7121. ) Is 170-220 ° C. and the melt flow rate is 1-50 g /
Use for 10 minutes (ASTM D1238, load 2.16 kg, temperature 230 ° C.). This melting point (ie,
The melting point of the base resin of the grain forming pigment masterbatch is 1
If the temperature is less than 70 ° C., the grain forming pigment masterbatch is completely melted at the molding processing temperature, so that the grain forming pigment masterbatch is not finely dispersed in the wood-based material-containing polyolefin-based resin composition and the grain is not formed. If the temperature exceeds 220 ° C., the grain forming pigment master batch does not soften and flow, which is not preferable. The melt flow rate (ASTM D1238, load 2.16 kg,
When the temperature is 230 ° C) is less than 1 g / 10 min, the wood-grain-forming pigment masterbatch does not emerge on the surface of the molded product, which is not preferable.

Further, a thermoplastic polyester elastomer having a large temperature range from the start temperature to the end temperature of the endothermic peak including the melting point temperature in the measurement by a differential scanning calorimeter (DSC) (hereinafter, referred to as a melt width) is used. Is preferred. A preferred melting width is 30 to 80 ° C.

In the present invention, the above-mentioned thermoplastic polyester elastomer is used as a base resin, but it is also possible to use a polyolefin resin as a part of the base resin. In that case, it is preferable to make the amount of the polyolefin resin smaller than the amount of the thermoplastic polyester elastomer.

Examples of pigments to be incorporated into the grain forming pigment master batch include, for example, carbon black, titanium oxide,
Organic or inorganic dyes and pigments that are commonly used for coloring synthetic resins such as titanium yellow and red iron can be used without any particular limitation. At that time, the content of the pigment is about 3 to 70% by weight, preferably 10 to 40% by weight, although it depends on the kind, color and color tone of the pigment used. As the dispersant, a usual dispersant such as magnesium stearate can be used without any particular limitation. At this time, the amount of the dispersant added is 0.05 to 1.5 wt% based on the total amount of the base resin and the pigment. The wood-grain-forming pigment masterbatch can be produced by mixing a base resin, a pigment, a dispersant, and the like at room temperature with a mixing device such as a Henschel mixer and kneading and granulating the mixture using a twin-screw extruder or the like.

The polyolefin-based resin molded article having a wood grain pattern according to the present invention comprises a wood-based material-containing polyolefin-based resin composition, a wood-grain-forming pigment masterbatch and, if necessary, the wood-based material-containing polyolefin, in a hopper of a molding machine. A pigment master batch for coloring the base resin composition itself or other additives is added, and the mixture is molded by the molding machine. Extrusion molding, injection molding, and other various molding methods can be applied as a molding method. Preferably, extrusion molding is used, and particularly preferably, modified extrusion molding is used. The molding temperature is
Since the woody material in the woody material-containing polyolefin-based resin composition begins to thermally decompose when the temperature exceeds 200 ° C.
The temperature may be appropriately selected in the range of 60 to 210 ° C. in consideration of the thermal fluidity of the wood-based material-containing polyolefin-based resin composition and the grain forming pigment master batch. Particularly, in the present invention, the thermoplastic polyester elastomer which is a base resin of the wood-grain-forming pigment master batch is used because the wood-grain-forming pigment master batch is in a semi-molten state and is dispersed in a streak shape during molding. Is preferably formed at a temperature at which it can take a semi-molten state. Therefore, a preferable forming temperature is not lower than the start temperature of the endothermic peak including the melting point temperature and not higher than the end temperature. It is more preferably (melting point−30 ° C.) or more and melting point or less.

The mixing ratio of the wood-based material-containing polyolefin-based resin composition and the wood-grain-forming pigment master batch is as follows:
The wood-grain-forming pigment master batch is 0.5 to 5 parts by weight per 100 parts by weight of the wood-based material-containing polyolefin-based resin composition.
It is preferred to use parts by weight. Furthermore, in order to adjust the color tone of the entire molded article, in the present invention, in order to color the wood-based material-containing polyolefin-based resin composition itself in addition to the wood-based material-containing polyolefin-based resin composition and the grain forming pigment master batch. To Shiraki, Light, Medium,
It is preferable to blend a coloring pigment master batch of a color such as dark. The preferred blending ratio of the pigment masterbatch for coloring is wood-based material-containing polyolefin-based resin composition 10.
It is 0.5 to 10 parts by weight with respect to 0 parts by weight.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. In this example, the following raw materials were used. <Polyolefin resin composition containing wood-based material> 40 parts by weight of polypropylene (homopolymer, melt flow rate at 230 ° C, 2.16 kg load: 0.5 g / 10 min, specific gravity: 0.91), high-density polyethylene (190
Melt flow rate at 2.degree.
01 g / 10 min, specific gravity 0.96) 30 parts by weight, esterified wood flour obtained by addition esterification of maleic anhydride to wood flour (the ratio of maleic anhydride introduced into wood flour is 2. 4 wt%) and 0.008 parts by weight of 1,3-bis (2-t-butylperoxyisopropyl) benzene as an organic peroxide were supplied to a twin-screw extruder, and the set temperature was set at 18.
The mixture was heated and kneaded at 0 ° C to obtain a wood-based material-containing polyolefin-based resin composition having a melt flow rate of 0.03 g / 10 minutes at 190 ° C and a load of 2.16 kg.

<Grain-forming pigment master batch> In a Henschel mixer, 70 parts by weight of the thermoplastic polyester elastomer shown in Table 1, 30 parts by weight of a reddish red pigment and 0.2 parts by weight of magnesium stearate as a dispersant were used. The mixture was mixed at room temperature, and then kneaded and granulated with a twin-screw extruder under the conditions of a barrel setting temperature of 200 ° C. and an extrusion kneading amount of 6 kg per hour to obtain a grain forming pigment master batch. Table 1 also shows the obtained grain forming pigment master batch.

[0024]

[Table 1]

Examples 1 to 6 100 parts by weight of a polyolefin resin composition containing a woody material, 5 parts by weight of a coloring pigment (white wood-like, base resin: low-density polyethylene), and a grain forming pigment master batch shown in Table 2 2 parts by weight were mixed with a blender, and an extruder (screw diameter = 50 mm, L / D = 32, 2 stages (first stage CR = 3.0, second stage C.I.
R = 2.3)), and at a resin temperature shown in Table 2, it was deformed and extruded from a die into a flat plate having a width of 150 mm × thickness of 3 mm to obtain a polyolefin resin molded product having a grain pattern. . Table 2 also shows the evaluation results for the texture and grain pattern of the obtained molded product.

[0026]

[Table 2]

Comparative Example 1 For comparison, the base resin of the grain forming pigment masterbatch was polypropylene (homopolymer, 230 ° C., 2.1
Melt flow rate at a load of 6 kg 0.5 g / 10
And a specific gravity of 0.91), except that the wood-based material-containing polyolefin resin composition was completely mixed with the coloring material master batch and the grain forming pigment master batch. No grain pattern was formed.

Comparative Example 2 Nylon 6 was used as the base resin of the grain forming pigment masterbatch.
Example 1 except that a / 12 copolymer (melting point: 155 ° C.) was used.
As a result, the pigment master batch for coloring and the wood grain forming pigment master batch were completely mixed in the polyolefin resin composition containing a wood-based material, and no wood grain pattern was formed.

Comparative Example 3 Ethylene propylene rubber (Mitsui Chemicals, Mitsui EPT X-3012P, manufactured by Mitsui Chemicals, Mooney viscosity: M) containing 0.2% of a crosslinking agent as a base resin of a grain forming pigment masterbatch
L (1 + 4) 100 ℃ is 15, ethylene content 75wt
%), Except that the wood-based material-containing polyolefin-based resin composition was completely mixed with the pigment masterbatch for coloring and the woodgrain-forming pigment masterbatch to form a woodgrain pattern. Was not done.

As is clear from the examples and comparative examples, when the wood-forming pigment masterbatch of the present invention, in which the base resin is a thermoplastic polyester elastomer having a specific melting point and melt flow rate, is used, the wood-based material is contained. The grain pattern was able to be given to the polyolefin resin molded article. On the other hand, in the case of a wood-based material-containing polyolefin resin molded product according to a comparative example using a wood-grain-forming pigment master batch made of polypropylene, nylon 6/12 copolymer, or ethylene-propylene rubber as a base resin, a wood-grain pattern is formed. Could not.

[0031]

According to the present invention, it is possible to impart a grain pattern to a molded article made of a polyolefin-based resin composition containing a wood-based material, which is suitable for various fields such as industrial parts materials and building materials. Can be used. In particular,
Housing materials, door materials as building materials, exterior wall materials, vanities, counter materials, window frames, wall materials, surrounding trees, handrails, structural materials, civil engineering timber, columns, floor columns, decorative columns, earthquake-resistant materials, ceiling fixtures Materials, shutter boards, sleeve boards, hip boards, side boards, base materials, flooring materials, large roofs, rolled roofs, upper and lower scroll boards, bus units (bus ceiling,
Bus wall, stool), pallet, concrete panel, scaffolding material, shielding plate, sound insulation plate, furniture box ceiling, door, front plate back plate,
It is useful for shelves, curtains, decks, backboards, seats, kitchen members, waterproofing materials, antifungal materials, antiseptic materials, home appliances (cabinet, stereo cabinet, amplifier cabinet, piano and organ master plates, etc.).

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C08L 97/02 C08L 97/02 // B29K 23:00 B29K 23:00 (72) Inventor Ken Watanabe Saitama 1813 Nishiyuuma, Omiya-shi 1-8 Nishiyuuma housing complex 8-403 F term (reference) 4F070 AA12 AB11 AC88 AC96 AE04 FA03 FA17 FB04 FC05 4F071 AA14 AA47 AA73 AA84 AA88 AE09 AH03 AH11 BB06 BC07 BC09 4F207 AA03 002A03 BB01 A002 BB051 BB061 BB071 BB081 BB121 BB151 BB171 CF033 CF103 DA036 DE116 DE136 FD096 GL00

Claims (4)

[Claims] 1. A method for producing a polyolefin resin molded article having a wood grain pattern, wherein a wood grain forming pigment master batch is blended with a wood based material-containing polyolefin resin composition comprising a wood based material and a polyolefin based resin, and molded.
Melting point (based on JIS K712 using a differential scanning calorimeter (DSC)) as the base resin of the wood-grain-forming pigment masterbatch
Measured according to 1. ) At 170 to 220 ° C. and a melt flow rate of 1 to 50 g / 10 min (ASTM D123
8. A method for producing a polyolefin-based resin molded article having a grain pattern, comprising using a thermoplastic polyester elastomer having a load of 2.16 kg and a temperature of 230 ° C.). 2. A wood grain-forming pigment master batch of 3 to 70 watts
The method for producing a polyolefin resin molded article having a wood grain pattern according to claim 1, comprising t% of a pigment. 3. The woodgrain pattern according to claim 1, wherein 0.5 to 10 parts by weight of a woodgrain-forming pigment masterbatch is added to 100 parts by weight of the woody material-containing polyolefin resin composition. A method for producing a polyolefin resin molded article having: 4. A melting point (measured according to JIS K7121 using a differential scanning calorimeter (DSC)) of 170 to 22.
0 ° C, melt flow rate 1-50 g / 10 min (AS
TM D1238, load 2.16 kg, temperature 230 ° C)
A wood batch-forming pigment masterbatch for a polyolefin resin, comprising a thermoplastic polyester elastomer as a base resin.