JP3265222B2 - Wood-like material manufacturing method - Google Patents

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-like member used for building materials such as a periphery of a house, a skirting board, a rain gutter, and an interior member of a vehicle.

[0002]

2. Description of the Related Art In recent years, various attempts have been made to provide synthetic resin moldings with properties close to those of natural wood, thereby making them substitutes for wood. As one of the methods, there is a method of blending cellulose-based powder particles such as wood powder with a synthetic resin to obtain a molded product. Such wood substitute materials are used as interior materials, furniture materials, structural materials and the like of houses.

[0003] However, in the above method, the cellulose-based particles are poorly compatible with the resin in the molten resin and are liable to agglomerate, so that the dispersion in the resin becomes uneven and the strength and appearance of the molded product may be reduced. . In addition, the cellulose-based powder is caught on the inner surface of the molding machine, so-called "build-up".
And the inner surface of the molding machine is damaged. Further, since the cellulose-based particles generate an acidic gas upon heating, there is a problem that the molding machine is gradually corroded and the life thereof is shortened. Further, the acidic gas generated from the cellulosic powder promotes the degradation reaction of the resin, and sometimes the molded product is discolored.

[0004] As a method of solving these problems,
A method has been disclosed in which the generated acidic gas is neutralized with a urea-based resin to render the gas harmless (Japanese Patent Application Laid-Open Nos. 55-116752 and 61-2505). However,
This method is unsuitable especially for the production of interior materials for houses because the odor derived from the urea-based resin remains in the product. Also, a method of suppressing the generation of acidic gas by coating the surface of wood powder with a white inorganic pigment or the like using a ball mill has been disclosed (JP-A-5-177610). However, there was a disadvantage that the degree of occurrence was not sufficient.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned disadvantages caused by the addition of cellulosic powder, suppress the generation of acidic gas from cellulosic powder, and prevent the deterioration of moldability. Another object of the present invention is to provide a manufacturing method capable of manufacturing a woody member having excellent woody feel.

[0006]

The object of the present invention is to provide a water content of 10%.
Cellulose-based powder having a particle size of 50 to 200 μm or less by weight.
Aluminum hydroxide in simple or combined amount to 100 parts by weight
And / or magnesium hydroxide powder 0.5 to
20 parts by weight are mixed, stirred and mixed to obtain a cellulose-based powder.
Aluminum hydroxide and / or water on the surface of the particles
Spread the magnesium oxide powder evenly and
Aluminum hydroxide and / or water
Coating with magnesium oxide powder and the resulting coating
Mixing cellulose cellulose powder and polypropylene resin,
Next, it was extruded and the semi-solid extruded from the extrusion die
On the surface of the molded product in the molten state, a surface with a depth of 10 to 50 μm
Press the embossed roll with the unevenness to
Form wood-like members by forming fine irregularities on the surface
The problem can be solved by a method of manufacturing wood-like members. In addition, the above problems
Is a cell having a water content of 10% by weight or less and a particle size of 50 to 200 μm.
For 100 parts by weight of Lulose powder, in plain or combined amount
Aluminum hydroxide and / or magnesium hydroxide
Of 0.5 to 20 parts by weight of the powder of
Aluminum hydroxide and aluminum hydroxide
And / or magnesium hydroxide powder evenly
To adhere the cellulose powder to aluminum hydroxide and
And / or coated with magnesium hydroxide powder,
Obtained coated cellulose powder and polypropylene
Mix the resin and then mold at least
The surface of the molding die corresponding to the surface
Injection using fine irregularities of ~ 50μm
Molding and forming a fine uneven pattern on the surface of the molded product
A method for producing a wood-like member, characterized by forming the same.
Can be solved by

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
With the cellulose-based powder used in the present invention, wood, bacas, rice straw, pulp and the like are mechanically coarsely pulverized,
This is a granular product obtained by further grinding, and preferably has a particle size of about 50 to 200 μm, and is obtained from woods such as toga, pine, lauan, and hinoki. Are preferred. Particle size 200μm
If it exceeds, clogging is likely to occur in the molding machine at the time of molding, and if it is less than 50 µm, the feeling of wood becomes poor. Also,
It is preferable that the moisture content of the cellulosic powder is 10% by weight or less, preferably 2% by weight or less, because foaming during molding can be prevented.

[0008] Cellulose-based particles are first coated with aluminum hydroxide and / or magnesium hydroxide. As these aluminum hydroxide and magnesium hydroxide, those having at least an average particle size smaller than the average particle size of the cellulosic powder particles are used. In particular, those having an average particle size of 0.1 to 30 μm are preferably used. If the average particle size is less than 0.1 μm, handling becomes difficult, and if it exceeds 30 μm, the effect of suppressing the release of acidic gas from the cellulose-based powder during molding is insufficient. General-purpose aluminum hydroxide and magnesium hydroxide may be used. These may be used alone or in combination of two kinds. In the present specification, the average particle size refers to the 50% by weight passage diameter of the cumulative weight% distribution of the powdery material.

In this coating treatment, the cellulosic powder and aluminum hydroxide and / or magnesium hydroxide are charged into a high-speed mixing device such as a super mixer or a Henschel mixer, a ball mill, a shaker, a raikai machine, or the like, and the temperature is 25 to 25. The stirring and mixing are performed at 80 ° C. for 0.5 to 2 hours. The amount of the aluminum hydroxide and / or magnesium hydroxide used is 0.1 or less in a simple or combined amount with respect to 100 parts by weight of the cellulosic powder.
It is preferred to be 5 to 20 parts by weight. This usage amount is 0.
If the amount is less than 5 parts by weight, the coating treatment of the cellulosic powder particles is not sufficiently performed, and if the amount exceeds 20 parts by weight, the moldability of the molded article is reduced.

[0010] By this treatment, the powder of aluminum hydroxide and / or magnesium hydroxide adheres to the surface of the particles of the cellulosic powder, and the surface is uniformly covered. Then, the thin film of aluminum hydroxide and / or magnesium hydroxide formed on the surface of the cellulose-based powder completely prevents the acid gas from diffusing.

The coated cellulosic powder is
Then, it is mixed with a polypropylene resin. The polypropylene resin used here is a homopolymer of propylene or a copolymer obtained by subjecting a small amount (20 mol% or less of the whole) of other monomers to random polymerization, block polymerization, or graft polymerization with propylene. Coalescing may be used. The monomer to be copolymerized with propylene may be any monomer having a reactive double bond.
-Butene, 1-pentene, 3-methyl-1-butene, 3
-Methyl-1-pentene, 4-methyl-1-pentene,
Α-olefins such as 4,4-dimethyl-1-pentene; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as butyl vinyl ether and cetyl vinyl ether; and acrylic acid esters such as methyl acrylate and ethyl acrylate. Methacrylates such as methyl methacrylate, ethyl methacrylate, phenyl methacrylate, styrene, aromatic vinyls such as α-methylstyrene, vinylidene chloride, vinyl halides such as vinyl fluoride, and N- such as N-cyclohexylmaleimide. Substituted maleimides, butadiene,
1,5-hexadiene, 1,7-octadiene, 1,9
Dienes such as decadiene and allyltrialkylsilanes can also be used. These monomers may be used not only one kind but also two or more kinds.

The mixing of the coated cellulose powder and the polypropylene resin is carried out by a super mixer, a Henschel mixer, a Banbury mixer or the like. The amount of the cellulose-based powder added is preferably 5 to 80 parts by weight based on 100 parts by weight of the polypropylene-based resin. The amount of this addition
If the amount is less than 5 parts by weight, woody texture cannot be obtained,
Exceeding the weight parts makes molding difficult.

At this time, in addition to the above-mentioned components, an antioxidant, an ultraviolet absorber, a light stabilizer, a pigment, a flame retardant, a filler,
Further, an additive such as an antistatic agent may be added according to the purpose of use. As the antioxidant, 2,6-di-
t-butyl-4-methylphenol, tetrakis- [methylene-3- (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) propionate] methane, n-octadecyl-3- (3 ′, 5 ′) Phenolic antioxidants such as -di-t-butyl-4'-hydroxyphenyl) propionate; thio-based oxidations such as dilauryl-3,3'-thiodipropionate and dimyristyl-3,3'-thiodipropionate. An antioxidant, a phosphorus-based antioxidant such as trisnonylphenyl phosphite may be used. In addition, hydrazine-based antioxidants, heavy metal deactivators and the like can be used.

As the ultraviolet absorber, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl)-
5-chlorobenzotriazole, 2- (2'-hydroxy-3'-di-t-butylphenyl) -5-chlorobenzotriazole, 2-hydroxy-4-n-octoxybenzophenone, or the like may be used. As a light stabilizer,
A hindered amine light stabilizer such as bis- (2,2,6,6-tetramethyl-4-piperidyl sebacate) may be used.

As the pigment, a brown pigment such as iron oxide, a black pigment such as carbon, and a white pigment such as titanium oxide may be used. Further, as the flame retardant, for example,
Although inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide, and organic flame retardants such as polybromodiphenyl oxide and tetrabromobisphenol A can be used, inorganic flame retardants are preferred from the viewpoint of preventing generation of harmful gases during combustion. . As the filler, for example, barium titanate whiskers, calcium carbonate whiskers, magnesium sulfate whiskers, boron-based whiskers, carbon fibers, fibrous materials such as glass fibers, or calcium carbonate, magnesium carbonate, mica, montmorillonite, etc. May be.

The use amount of the above-mentioned additives is not particularly limited, and is appropriately selected within the range of the usual use amount. However, aluminum hydroxide and magnesium hydroxide which coat the cellulosic powder have a function of making them flame-retardant when added to a resin or the like, so that the amount of flame retardant used can be reduced accordingly. These additives are
The mixture may be added to the cellulose-based powder and the polypropylene-based resin at the time of mixing, or may be added to the cellulose-based powder or the polypropylene-based resin before mixing.

Then, the mixture is extruded or injection-molded to produce a desired wood-like member. For extrusion molding, a usual extruder such as a single screw extruder or a twin screw extruder is used. Extrusion conditions are as follows: die temperature is 22
The temperature is about 0 to 300 ° C., and a T-die, a round die, a modified die, a hollow modified die, or the like is used as the extrusion die. The shape of the extruded product is not limited, and may be any shape such as a plate, a pipe, and a hollow rectangular tube.

In the case of employing extrusion molding, an embossing roll may be pressed against a semi-molten molded product extruded from a die to transfer a fine uneven pattern provided on the surface of the embossed roll to the molded product surface. it can. In particular,
For example, in the form of a sheet extruded from a die, a temperature of 12
For example, a method in which a semi-molten molded product at about 0 to 180 ° C. is sandwiched between two rolls and one of the rolls is used as an emboss roll when cooling is employed. As the embossing roll, a metal roll or a rubber roll such as silicone rubber is used. Since the unevenness of the surface of the embossing roll is for enhancing the woody feeling of the woody member as a molded product, its depth is sufficient to be 10 to 50 μm, and the arrangement and arrangement of the unevenness are also necessarily regular. No need.

When the injection molding is employed, a usual injection molding machine, for example, an in-line screw type injection molding machine is used. As a molding die, a two-piece type, a three-piece type, a stack type or the like is used, and a hot runner or the like is used for a runner type. Molding conditions are: mold temperature 30 to 80
° C, resin temperature 200-300 ° C, injection time 10-60
The injection pressure is 600 to 1400 kg / cm ² per ^second , but other conditions may be used depending on the size and shape of the molded product. Further, it is also possible to obtain a molded product having a small internal stress by a low-pressure molding method in which the resin pressure in the molding die is reduced in the injection step and increased in the pressure-holding step.

Further, as a molding die, a die provided with fine irregularities on the surface of the molding die corresponding to at least the surface portion of the molded product is used. It is possible to form a rough uneven pattern and to further enhance the wooden texture. Since the unevenness of the molding die is also for enhancing the woody feeling of the molded product, the depth of the unevenness is set to 10 to 50 μm, and the arrangement and arrangement may be irregular.

In the method for producing such a wood-like member,
Since the surface of the cellulose-based powder is evenly coated with aluminum hydroxide and / or magnesium hydroxide, even when heated during molding, no acidic gas is radiated from the inside to the outside, and the deterioration of the polypropylene-based resin. Discoloration of the product due to the decomposition reaction and corrosion of the inner surface of the molding machine can be prevented.

Furthermore, by coating the cellulose-based particles, the cellulose-based particles are uniformly dispersed in the polypropylene-based resin, do not agglomerate, and clogging in the molding machine due to the blending of the cellulose-based particles. The strength and appearance of the obtained wood-like member can be improved. Also,
By pressing an embossing roll at the time of extrusion molding or using a molding die having fine irregularities formed at the time of injection molding, a natural texture similar to that of natural wood can be obtained on the wood-like member, and the wood texture can be further enhanced.

Further, by using aluminum hydroxide and / or magnesium hydroxide having a flame-retarding action, it is possible to impart high flame retardancy to the product. Further, since a polypropylene resin having high thermal stability and low viscosity at the time of melting is used, the mixture has excellent heat stability, fluidity at the time of melting, and good moldability. Therefore, a product having a complicated shape can be easily manufactured by extrusion molding or injection molding.

Further, since a polypropylene resin having high cold resistance and oil resistance is used, a product excellent in these characteristics can be obtained. In addition, since a polypropylene-based resin having a small specific gravity is used, the product can be made lightweight. In addition, the use of halogen-free polypropylene-based resin does not emit harmful gases such as halide gas during combustion, and is highly safe in the event of a fire and causes the generation of dioxin compounds during incineration. Therefore, it is possible to obtain a favorable product from the viewpoint of environmental protection. Further, since it does not contain a substance emitting an unpleasant odor, it is possible to obtain a product which can be used as an interior material of a house.

The wood-like member obtained by the above method is
For example, it is suitably used for a peripheral edge of a house, a baseboard, an exterior material, a floor material, a wall material, a door frame, a window frame, a decorative board such as furniture, an interior member of a vehicle, and the like.

The following is a specific example. (Coating treatment of cellulosic powder particles) Cellulose powder particles and aluminum hydroxide and magnesium hydroxide in the amounts shown in Table 1 were charged into a super mixer, and the temperature was 40 to 8
The mixture was mixed at 0 ° C. for about 1 hour to perform a coating treatment, thereby producing seven types of blends (Sample Nos. 1 to 7). At the same time, cellulosic powder particles not coated with aluminum hydroxide and magnesium hydroxide were prepared (Sample No. 8). As cellulosic powder, wood for building materials is dried and pulverized,
Further, the water content after grinding was 3.0% by weight, and the average particle size was 10%.
The thing of 0 μm was used.

[0027]

[Table 1]

(Mixing of Cellulose Particles and Polypropylene Resin) These eight kinds of cellulose particles are mixed with 100 parts by weight of a polypropylene resin (propylene homopolymer) and 0.2 parts by weight of a coloring pigment (iron oxide). 20 parts by weight of the mixture, and the mixture was stirred with a super mixer for 10 minutes and mixed to form a mixture.

(Extrusion molding) This mixture was supplied to a twin-screw extruder having the following specifications, and molded under the following molding conditions to obtain plate-like molded articles (Sample Nos. A to H). In addition, the embossing roll made of silicone rubber was used as the second roll of the cooling roll, and fine irregularities were formed on the surface of the molded body.

The surface condition of the obtained molded product was evaluated. A sample having a smooth and natural woody feeling was evaluated as ○, and a sample having unnatural roughness and rough skin was evaluated as ×.
Regarding the moldability, those having clogging in the extruder during molding were evaluated as x, and those not clogging were evaluated as o. Table 2 shows the results.

[0031]

[Table 2]

From the results shown in Table 2, it can be seen that an excellent woody member rich in woodiness can be produced satisfactorily and stably by the extrusion molding method.

(Injection molding) The above mixture was molded under the following molding conditions to obtain a box-shaped molded product (Sample Nos. I to C). As a molding die, one having an embossment having a depth of about 10 μm on its cavity surface was used. Molding condition Cylinder nozzle temperature: 230 ° C Mold temperature: 50 ° C Resin temperature: 230 ° C Injection time: 10 seconds Molding cycle: 35 seconds

The surface condition of the obtained molded product was evaluated. A sample having a smooth and natural woody texture was evaluated as ○, and a sample having unnatural roughness and rough skin was evaluated as ×.
Regarding the moldability, those with clogging in the cylinder during molding were evaluated as x, and those without clogging were evaluated as ○. Table 3 shows the results.

[0035]

[Table 3]

From the results shown in Table 3, it can be seen that, according to the present invention, an excellent wood-like member rich in woodiness was successfully and stably produced by injection molding.

[0037]

As described above, according to the manufacturing method of the present invention, a wood-like member having the natural texture of natural wood can be stably and efficiently manufactured.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI // B29K 23:00 B29K 23:00 105: 16 105: 16 B29L 31:10 B29L 31:10 (58) Fields surveyed (Int .Cl. ⁷ , DB name) B29C 47/00-47/96 B29C 45/00 B29C 59/00 B29C 59/04

Claims (2)

(57) [Claims] (1) a water content of 10% by weight or less and a particle size of 50 to 20;
For 100 parts by weight of 0 μm cellulose-based powder,
Or the combined amount of aluminum hydroxide and / or
Mixing 0.5 to 20 parts by weight of powder of gnesium and stirring,
Mix and add hydroxide hydroxide to the surface of the cellulose-based particles.
Minium and / or magnesium hydroxide powder
Adhere evenly and remove cellulose-based powder
Coated with minium and / or magnesium hydroxide powder
Coated and the resulting coated cellulose powder and polyp
The propylene-based resin is mixed, then extruded and extruded.
The surface of the molded product in the semi-molten state extruded from the chair
Embossed surface with unevenness of 10 to 50 μm depth
To form a fine uneven pattern on the surface of the molded product
Characterized by forming a wood-like member by forming
Recipe. 2. A water content of 10% by weight or less and a particle size of 50 to 20.
For 100 parts by weight of 0 μm cellulose-based powder,
Or the combined amount of aluminum hydroxide and / or
Mixing 0.5 to 20 parts by weight of powder of gnesium and stirring,
Mix and add hydroxide hydroxide to the surface of the cellulose-based particles.
Minium and / or magnesium hydroxide powder
Adhere evenly and remove cellulose-based powder
Coated with minium and / or magnesium hydroxide powder
Coated and the resulting coated cellulose powder and polyp
A propylene-based resin is mixed, and then a molding
Mold surface corresponding to at least the surface part of the mold
On which fine irregularities with a depth of 10 to 50 μm are formed
Injection molding using
Characterized by forming a wood-like member by forming
Manufacturing method for similar members.