KR20020018913A - Components and preparation method of artificial wood - Google Patents

Abstract

PURPOSE: An artificial wood composition and its preparation method are provided, to obtain an artificial wood having similar appearance and texture to that of natural wood by extrusion and to improve the biodegradability by increasing the content of wood meal. CONSTITUTION: The artificial wood composition comprises a first mixture comprising a relatively low molecular weight synthetic resin, 1-3 wt% of a dispersant, 1-8 wt% of a modifier, and wood meal; and a second mixture comprising a relatively high molecular weight synthetic resin, 0.05-0.5 wt% of a cross-linking agent and wood meal, based on the total amount of the composition. The ratio of the synthetic resin and wood meal is 3:7 to 7:3 by weight in the first and second mixture; and the ratio of the first mixture and the second mixture is 6:4 to 9:1 by weight. Preferably the wood meal comprises 60-80 wt% of wood meal with a size of 80-150 mesh, and 20-40 wt% of wood meal with a size of 30-60 mesh. Preferably the relatively low molecular weight synthetic resin is polypropylene with a melt index of 5-6, and the relatively high molecular weight synthetic resin is polypropylene with a melt index of 0.1 or less.

Description

Artificial wood composition and manufacturing method of artificial wood {Components and preparation method of artificial wood}

The present invention relates to artificial wood, and more particularly, to a new artificial wood composition using a mixture of wood powder and synthetic resin and to a method for producing artificial wood using the same.

Wood is used for various facilities such as leisure, sports, and landscaping, as a flooring material for vans and containers, but it is pointed out that problems such as frequent deformation due to moisture and corrosion occur.

Artificial wood was developed to solve this problem. In general, artificial wood is produced by kneading and extruding a synthetic resin such as polyethylene, polyvinyl chloride, polypropylene, polyester, and fillers such as wood powder, inorganic powder and the like.

For example, in the prior art related to artificial wood, Korean Patent No. 163076 has a pulverized cellulose powder as a raw material to increase the specific gravity of the powder, and to fix the surface grains of smaller diameter and harder than that A method for producing artificial wood, which is to form a high granule, mix and melt a resin and a pigment with the high granule, or simultaneously form the molten granule, has been proposed, and Korean Patent Publication No. 95-24847 discloses a water content of 15 wt% or less. 20 to 75% by weight of cellulose-based crushed matter having an average particle diameter of 20 mesh or less, 25 to 80% by weight of thermoplastic resin molding material is mixed, gelled and kneaded, cooled and pulverized and granulated wood granules of which particle size is within 10 mm are extruded. A method of preparing is provided. Artificial wood produced by this method is superior in terms of durability compared to natural wood, but has the disadvantages such as poor appearance and poor biodegradability.

In order to give the appearance of natural wood like the appearance of natural wood, the coating of wood grain pattern or coating is used, but this method not only raises the production cost due to the addition of the process, but also damages the beauty when the coating is peeled off. There are disadvantages such as greatly deteriorating the quality of the facility using the same.

In addition, it is necessary to increase the content of wood flour to increase the biodegradability of artificial wood, but it is practically impossible to increase the wood powder content by more than 40% by the known method, because the conventional method is the wood flour and synthetic resin from the hopper to the extruder This is because it is impossible to obtain a product of uniform physical properties when more than 40% of wood flour is added because it does not enter uniformly due to the difference in bulk density.

Therefore, the present invention can not only impart a separate pattern giving process but also give the same appearance and texture as natural wood, and can increase the content of wood powder, thereby improving the biodegradability, and the new artificial wood composition and artificial using the same. It is an object to provide a method for producing wood.

In the study of the present inventors to solve the above problems, by using two kinds of synthetic resins having different molecular weights as a synthetic resin, by mixing a specific additive and wood powder in each synthetic resin, and by mixing each mixture obtained thereby and extruding It has been found that it is possible to increase the content of wood flour, have good physical properties, and in particular, to produce artificial wood having the same appearance as natural wood.

1 is a block diagram schematically showing a manufacturing process of artificial wood according to the present invention.

Therefore, according to the present invention, an artificial wood composition mainly composed of synthetic resin and wood powder includes: a first mixture containing a relatively low molecular weight low molecular weight synthetic resin, a dispersant, a modifier, and wood powder; There is provided an artificial wood composition comprising a relatively high molecular weight high molecular weight synthetic resin and a second mixture containing a crosslinking agent and wood powder.

In addition, according to the present invention, the preparation of the artificial wood, characterized in that it comprises the steps of preparing a first mixture and a second mixture, kneading the first mixture and the second mixture, and extruding the resulting mixture A method is provided.

Hereinafter, the present invention will be described in more detail by way of preferred embodiment.

The artificial wood composition of the present invention is composed of a low molecular weight synthetic resin, a dispersant, a modifier and a first mixture containing wood powder and a second mixture containing high molecular weight synthetic resin, a crosslinking agent and wood powder. According to the present invention, when the first mixture and the second mixture are formed as described above, each mixture can be easily granulated to achieve uniform kneading of the first mixture and the second mixture easily, and in particular, the first mixture during extrusion. Due to the fluidity of the second mixture and the second mixture, the external appearance such as grain of natural wood is formed in the extrudate. The low molecular weight synthetic resin and the high molecular weight synthetic resin may be homogeneous or heterogeneous. That kind is well known in the art. For example, high density polyethylene, polyvinyl chloride, polypropylene, polyester and the like can be used. For example, when polypropylene having different molecular weights is used as the synthetic resin, it is preferable to use a low molecular weight synthetic resin having a melt index (MI) of 5 to 6 and a high molecular weight synthetic resin having a melt index of 0.1 or less. Do.

The mixing ratio of the low molecular weight synthetic resin and the wood powder in the first mixture of the present composition, and the mixing ratio of the high molecular weight synthetic resin and the wood powder in the second mixture are 3: 7-7: 3, preferably 6: 4-4: 6 in weight ratio, respectively. The degree is adequate. It is preferable to use a wood powder having a particle size of 30 to 150 mesh, in particular 60 to 80% by weight of wood powder having a particle size of 80 to 150 mesh and 40 to 20% by weight of a wood powder having a particle size of 30 to 60 mesh When used, it is effective because excellent texture and physical properties can be obtained. As the content of wood flour in the composition increases, the wood texture is maintained and the flexural strength is increased.

In the description of each component, first, the crosslinking agent is contained only in the second mixture. The main reason is that when the crosslinking agent is mixed with a low molecular weight synthetic resin, which is a low molecular weight resin, a crosslinking (curing) reaction occurs due to the heat generated during mixing. This is because large aggregates are formed and as a result it is difficult to achieve uniform kneading. In addition, the crosslinking agent also serves to prevent the degradation of properties even if a large amount of wood flour is added to obtain the texture of the wood. The content of the crosslinking agent is preferably about 0.05 to 0.5% by weight based on the total weight of the composition. If the content of the crosslinking agent is less than this, the effect of addition is insufficient, and in many cases, the physical properties increase, but processing becomes difficult. The type of crosslinking agent is not particularly limited and may be a conventional one known in the art.

On the other hand, the dispersant is contained only in the first mixture, the main reason is to make the melt flow of the first mixture higher than the melt flow of the second mixture to form a pattern such as natural wood in the extrudate.

Dispersants are suitably 1 to 3% by weight, based on the total weight of the composition. If the amount of the dispersant is excessive, kneading becomes difficult. Although not particularly limited, a dispersant is preferably a carboxyl dispersant.

The modifier is suitably from 1 to 8% by weight, based on the total weight of the artificial wood composition. If the amount of the modifier in the composition is contained in less than the above range, the modification effect is insufficient, and when excessively, the further modification effect is not improved and only the cost is increased. The type of the modifier is not particularly limited and may be a conventional one known in the art, but it is preferable to use a maleic anhydride as the modifier, because it may show excellent modifying effects.

The blending ratio of the first mixture to the second mixture in the composition is 6: 4-9: 1, preferably 7: 3-8: 2 by weight.

Moreover, a coupling agent can also be mix | blended with this composition. When combining a coupling agent, it is preferable to mix | blend at the time of manufacture of a 2nd mixture, and the addition amount is 0.05-0.5 weight% based on the composition total weight. If desired, a flocculant such as melamine or paraffin may be used to promote the aggregation of the small particles in the preparation of the first mixture or in the preparation of the second mixture. In addition, the present composition may be blended with other conventional additives well known in the art.

Hereinafter, the artificial wood manufacturing method of the present invention will be described.

The manufacturing method includes preparing a first mixture and a second mixture separately, kneading the obtained first mixture and the second mixture together, and extruding the obtained mixture.

The preparation of the first mixture consists of preparing a granular first mixture by putting a low molecular weight synthetic resin, a dispersant, a modifier and a wood powder into a mixer capable of high speed rotation at a predetermined ratio and rotating at high speed.

The preparation step of the second mixture consists of high molecular weight synthetic resin, crosslinking agent and wood flour in a mixer capable of high speed rotation at a predetermined ratio and rotating at high speed to produce a granular first mixture.

A preferred example of the high speed mixer that can be used in the preparation of the first mixture and the second mixture is a Henschel mixer. Of course, the present invention is not limited thereto, and it is also possible to use a conventional high speed mixer. When the mixture is mixed under high speed using a high speed mixer, the mixture is granulated due to the internal heat of 60 to 80 ° C., which is usually generated by the mixing.

The first mixture and the second mixture thus prepared are kneaded in a predetermined container, and then extruded in an extruder to form artificial wood. As such, when the first mixture and the second mixture are prepared, kneaded and extruded, the second mixture is slower in fluidity than the first mixture in the extruder, thereby forming a pattern such as natural wood in the extrudate.

Hereinafter, the present invention will be described by way of examples. Features and other advantages of the present invention as described above will become more apparent from the following examples.

EXAMPLE

Into the Henschel mixer, polypropylene (MI 5.5) and 80-150 mesh wood flour were added at a weight ratio of 5: 5, and an appropriate amount of maleic anhydride was added thereto as a carboxyl dispersant and a modifier, followed by mixing at 800 rpm for agitation. The first mixture in a state was prepared. Separately, polypropylene (MI 0.5) and 30-60 mesh wood flour were added to a Henschel mixer at a weight ratio of 4: 6, and an appropriate amount of dicumyl peroxide as a silane coupling agent and a crosslinking agent was added thereto, followed by mixing at 800 rpm. A granular second mixture was prepared. The obtained first and second mixtures were introduced into the kneader at various ratios shown in Table 1 below, and kneaded at a stirring speed of 40 rpm (in the mixture, the content of the dispersant was 2% by weight, the content of the modifier was 5%, The content of the crosslinking agent was 0.2% by weight, the content of the coupling agent was 0.2%. The flexural strength of the obtained artificial wood was measured by the method of ASTMD790, and the appearance was observed. The evaluation results are shown in Table 1.

From the above results, it can be seen that as the content of the first mixture increases, the physical properties become better, but the texture of the pattern is inferior.

As described above, the artificial wood of the present invention has the same appearance and texture as the natural wood by extrusion, and also has the advantage of greatly improving biodegradability since it can increase the content of wood flour.

Claims (8)

An artificial wood mainly comprising synthetic resin and wood powder, comprising: a first mixture containing a relatively low molecular weight low molecular weight synthetic resin, a dispersant, a modifier, and wood powder; An artificial wood composition comprising a second mixture containing a relatively high molecular weight high molecular weight synthetic resin, a crosslinking agent, and wood flour. The method of claim 1, wherein the mixing ratio of the low molecular weight synthetic resin and wood flour in the first mixture is 3: 7 to 7: 3 by weight, and the mixing ratio of the high molecular weight synthetic resin and wood powder in the second mixture is 3: 7 to 7 by weight. : 3, the content of the crosslinking agent is 0.05 to 0.5% by weight based on the total weight of the composition, the dispersant is 1 to 3% by weight based on the total weight of the composition, the modifying agent is 1 to 8% by weight based on the total weight of the composition, the first mixture The blending ratio of the two mixtures is 6: 4 to 9: 1 by weight ratio artificial wood composition. The artificial wood composition according to claim 1, wherein the wood powder consists of 60 to 80% by weight of wood powder having a particle size of 80 to 150 mesh and 40 to 20% by weight of wood powder having a particle size of 30 to 60 mesh. The artificial wood composition according to claim 1, wherein the low molecular weight synthetic resin is polypropylene having a melt index of 5 to 6, and the high molecular weight synthetic resin is a polypropylene having a melt index of 0.1 or less. CLAIMS 1. A method for producing artificial wood, mainly comprising synthetic resin and wood powder, comprising: a first mixture containing a relatively low molecular weight low molecular weight synthetic resin, a dispersant, a modifier, and wood powder; Preparing second mixtures each containing a relatively high molecular weight high molecular weight synthetic resin, a crosslinking agent, and wood flour; A method of manufacturing artificial wood, comprising the steps of kneading the first mixture and the second mixture, and extruding the obtained mixture. The mixing ratio of the low molecular weight synthetic resin and wood flour in the first mixture is 3: 7 to 7: 3 by weight, and the mixing ratio of the high molecular weight synthetic resin and wood flour in the second mixture is 3: 7 to 7 by weight. : 3, the content of the crosslinking agent is 0.05 to 0.5% by weight based on the total weight of the composition, the dispersant is 1 to 3% by weight based on the total weight of the composition, the modifying agent is 1 to 8% by weight based on the total weight of the composition, the first mixture The blending ratio of the mixture 2 is a weight ratio of 6: 4 to 9: 1 manufacturing method of artificial wood. The method for manufacturing artificial wood according to claim 5, wherein the wood powder consists of 60 to 80% by weight of wood powder having a particle size of 80 to 150 mesh and 40 to 20% by weight of wood powder having a particle size of 30 to 60 mesh. . The method of claim 5, wherein the low molecular weight synthetic resin is a polypropylene having a melt index of 5 to 6, and the high molecular weight synthetic resin is a polypropylene having a melt index of 0.1 or less.