KR101854866B1 - synthetic wood composition with discoloration-resistance and preparing method thereof - Google Patents

Abstract

The present invention relates to a synthetic wood composition used as a structural material such as a bench or a stairway such as a park or a hiking trail, and a method for producing synthetic wood using the synthetic wood composition. More particularly, the present invention relates to a wood powder composition comprising wood powder, UV absorber and wood preservative ; A raw material composition comprising a thermoplastic resin and a UV stabilizer; An additive composition comprising a lubricant, a colorant, a binder and a reinforcing agent, wherein the colorant comprises copper oxide (Cu ₂ O) and iron oxide (Fe ₃ O ₄ ).
According to the present invention, there is an advantage that discoloration of synthetic wood can be prevented, and excellent appearance quality can be maintained for a long period of time.

Description

[0001] The present invention relates to a synthetic wood composition resistant to discoloration,

The present invention relates to a synthetic wood composition used as a structural material such as a bench or a stairway such as a park or a hiking trail, and a method for producing synthetic wood using the synthetic wood composition. More particularly, To a strong synthetic wood composition and a method of manufacturing the same.

Wood is widely used as eco-friendly building interior and exterior materials such as flooring of buildings, interior doors, window frames and the like. Most of these woods are made of wood preservatives, which are processed by penetrating preservatives into natural wood.

However, such natural wood or wood preservative is excellent in workability, but is extremely weak in strength, easily deformed by external temperature change, moisture, impact, etc., and is not semi-permanent, There are disadvantages. In addition, in the case of the anticorrosive material, a large amount of environmentally harmful substances were released, thereby limiting the use thereof. Further, when the wood is exposed to ultraviolet rays for a long time over time, the wood is whitened or the oil stain is evaporated to discolor, which loses its function as a landscape gardening material.

Therefore, synthetic wood which is formed by mixing synthetic resin and wood instead of natural wood or anticorrosive material as described above is widely used for outdoor stairs or decks.

The synthetic wood is produced by uniformly blending raw wood pulverized wood, thermoplastic synthetic resin and other additives, extruding and molding the mixture through a certain mold according to the use, and cutting and cutting the wood to suit the application such as the user's surface treatment not slipping It completes. Such synthetic wood has a texture similar to that of natural wood, and has advantages of high durability and abrasion resistance.

However, although the synthetic wood is considered to be relatively resistant to discoloration compared to natural wood or wood preservative, there is a problem that the original color frequently changes after 3 to 5 years.

The prior art for preventing discoloration of the synthetic wood is disclosed as follows.

In Korean Patent Laid-Open No. 10-2012-0009093, iron oxide powder and ocher powder were used as a colorant to prevent discoloration, but this also prevented discoloration from occurring during long-term use.

KR 10-2012-0009093A

Therefore, an object of the present invention is to solve the problems of the conventional synthetic wood described above, and it is an object of the present invention to provide a wood-based composite material which is obtained by mixing a wood stabilizer, a UV absorber, a colorant including copper oxide and iron oxide, And a synthetic wood is formed by using the composition to prevent discoloration of the synthetic wood so that it can be used for a long time as a landscape gardening material.

According to an aspect of the present invention, there is provided a wood-based synthetic wood composition comprising wood flour, a UV absorber, and a wood preservative; A raw material composition comprising a thermoplastic resin and a UV stabilizer; An additive composition comprising a lubricant, a colorant, a binder and a reinforcing agent, wherein the colorant comprises copper oxide (Cu ₂ O) and iron oxide (Fe ₃ O ₄ ).

Wherein the wood preservative is 3-iodo-2-propynylbutyl carbamate (IPBC), wherein the lubricant comprises copper oxide and pyridione zinc in a weight ratio of 1: 1 to 1.2, The coloring agent is characterized by comprising copper oxide (Cu ₂ O) and iron oxide (Fe ₃ O ₄ ) in a weight ratio of 1: 2.5 to 3.5.

The lubricant is contained in a proportion of 50 to 65 wt%, the raw material composition is 25 to 35 wt%, the lubricant is 3 to 5 wt%, the colorant is 3 to 7 wt%, the binder is 1 to 3 wt%, and the reinforcing agent is 3 to 5 wt% Said wood flour composition comprising 97 to 99.89% by weight of wood powder, 0.1 to 2% by weight of UV absorber and 0.01 to 1% by weight of wood preservative, said raw composition comprising 99 to 99.5% by weight of thermoplastic resin and 0.5 to 1% .

The method for producing a synthetic wood composition resistant to discoloration according to the present invention comprises a wood flour composition comprising wood powder, UV absorbent and wood preservative; A raw material composition comprising a thermoplastic resin and a UV stabilizer; And a binder; and extruding the mixture to prepare a composition in the form of a pellet; a raw material composition comprising a thermoplastic resin and a UV stabilizer; slush; coloring agent; Binder; And a reinforcing agent are mixed and extruded to prepare a pellet-like composition, heating and stirring the two pellet-shaped compositions at a temperature of 150 to 200 ° C, molding the heated and stirred composition Wherein the colorant comprises copper oxide (Cu ₂ O) and iron oxide (Fe ₃ O ₄ ).

According to the present invention, there is an advantage that discoloration of synthetic wood can be prevented, and excellent appearance quality can be maintained for a long period of time.

1 and 2 are test reports showing the results of Example 1 according to Test Example 1. Fig.
Figs. 3 and 4 are test reports showing the results of Comparative Example 1 according to Test Example 1. Fig.

Hereinafter, the present invention will be described in detail.

Conventional synthetic wood has excellent physical properties and durability, so it is being applied to trails, deck roads, ecological parks and observation decks in place of natural wood or barrier wood. However, such synthetic wood also has a disadvantage in that it is discolored over time, and its value as a landscape material is deteriorated when it is used for a long time.

Therefore, the present invention prevents the discoloration of synthetic wood, thereby enhancing the value as a landscape gardening material. To this end, the present invention is characterized in that powder obtained by mixing copper oxide (Cu ₂ O) and iron oxide (Fe ₃ O ₄ ) is used as an inorganic coloring agent.

That is, conventionally, only iron oxide is used as a coloring agent. However, the present invention is to produce a synthetic wood which is resistant to discoloration by mixing copper (O ₂ O) oxide and iron oxide (Fe ₃ O ₄ ) as a coloring agent.

Hereinafter, the synthetic wood composition according to the present invention will be described.

The discoloration-resistant synthetic wood composition of the present invention comprises a wood flour composition comprising wood powder, UV absorber and wood preservative; A raw material composition comprising a thermoplastic resin and a UV stabilizer; Wherein the additive composition comprises a lubricant, a colorant, a binder and a reinforcing agent, wherein the colorant is a mixture of copper oxide (Cu ₂ O) and iron oxide (Fe ₃ O ₄ ).

First, the wood flour composition of the present invention is composed of wood powder, UV absorbent and wood preservative.

The wood flour may be produced by shredding recycled materials such as chips, shaving, and sawdust, or may be manufactured by shredding new wood that is not a recycled product. In the present invention, the woodywood having a fiber length of 1.0 to 1.2 mm is preferably pulverized to a size of 30 to 100 meshes. The reason for using the above-mentioned softwood logs is that coniferous trees such as pine trees have relatively higher specific gravity than the broad-leaved trees and can produce particles uniformly. This is because broad-leaved trees have a relatively larger fibrous structure than conifers, and the interstitials have a negative impact on the strength of the synthetic wood because of the more sex-friendly nature compared to the conifers. When the particle size of the wood powder is more than 30 mesh, the dimensional stability and elastic modulus of the synthetic wood are lowered. When the particle size of the wood powder is less than 100 mesh, the wood particles may become difficult to be mixed together due to too small wood powder. The wood powder preferably has a length to diameter ratio of 3: 1 to 5: 1. If the wood powder is out of this ratio, the physical properties of the synthetic wood may not be good.

The wood powder should be dried to a moisture content of 1 to 2% by weight, because moisture affects the surface properties of the synthetic wood, the defect rate, and the like. That is, when the moisture content of the wood powder exceeds 2%, moisture is evaporated during the molding of the synthetic wood, causing air bubbles and the like, adversely affecting the surface properties of the synthetic wood, weakening the bonding force with the resin, And the like. The wood powder is dried at room temperature, that is, through natural drying to have a water content of about 6 to 10%, and dried again using a drier, preferably a hot air drier to lower the water content of the wood powder to 1 to 2% . This is so as not to increase the manufacturing cost in the production of wood flour but to sufficiently reduce the moisture content of the wood flour so as not to affect the surface properties and defective rate of the synthetic wood.

The UV absorbers prevent degradation of the mechanical properties of wood flour by ultraviolet rays, discoloration and the like. The UV absorber may be selected from a variety of products known in the art to which the UV absorber is exemplified by 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy- (2-hydroxy-3,5-ditertiary-butylphenyl) -5-chlorobenzotriazole may be used. .

The wood preservative inhibits the occurrence of contamination of wood flour by microorganisms and the like, thereby enhancing the mold resistance of the synthetic wood. As the wood preservative, 3-iodo-2-propynylbutyl carbamate (IPBC) is preferably used. That is, conventional wood preservatives do not use a wood preservative, which causes disadvantages in that the wood is brittle. Accordingly, the present invention overcomes these disadvantages through the wood preservative IPBC.

It is also preferable that the ratio of the wood powder 97 to 99.89 wt%, the UV absorbent 0.1 to 2 wt%, and the wood preservative 0.01 to 1 wt%.

If the content of the wood flour composition is too low, the function as a wood is deteriorated and the plasticity becomes too strong. Conversely, when the content of the wood flour composition is too high, the thermoplastic resin The content of the water-soluble polymer is reduced.

The raw material composition includes a thermoplastic resin and a UV stabilizer. The thermoplastic resin may be at least one selected from the group consisting of polyethylene (PE), polyvinyl chloride (PVC), and polypropylene (PP) as a plastic raw material for producing synthetic wood.

The UV stabilizer enhances stability by ultraviolet rays and blocks ultraviolet rays from the sunlight to prevent discoloration of the thermoplastic resin. In the present invention, the type of the UV stabilizer is not limited. Various types of UV stabilizers known in the art can be used. For example, salicylate, benzophenone, benzotriazole, cyanoacrylate , Benzoate-based, triazine-based, and amine-based ultraviolet stabilizers.

The raw material composition is preferably composed of 99 to 99.5% by weight of a thermoplastic resin and 0.5 to 1% by weight of a UV stabilizer.

The raw material composition is preferably contained in the synthetic wood composition in an amount of 25 to 35% by weight. When the content is less than 25% by weight, durability and the like are poor. When the content is more than 35% by weight, characteristics of the wood are decreased.

The synthetic wood compositions of the present invention use lubricants, reinforcing agents, colorants and binders as additives.

The lubricant includes an antifouling agent and an antifouling agent to prevent the growth of vegetable fungi and animal fungi. As such an antifouling agent, it is preferable to use a powder obtained by mixing copper oxide (Cu ₂ O), which is an antifouling agent, and Zinc prithione, an organic antifouling agent, in a weight ratio of 1: 1 to 1.2. At this time, the particle size of the powder is not limited. The lubricant not only serves to increase the mold resistance of the synthetic wood but also serves to increase the dispersion of the wood powder during the processing of the synthetic wood. It is possible to further include a general lubricant such as antifouling agent and paraffin wax, Do.

The lubricant is preferably contained in the synthetic wood composition in an amount of 3 to 5% by weight. When the amount of the lubricant is less than 3% by weight, it is difficult to improve mold resistance and function as a lubricant. to be. Most preferably, the organic antifouling agent and the antifouling agent are used in an amount of 1 to 3% by weight in the composition, and the remaining lubricant is used in an amount of about 2% by weight.

The colorant is used for imparting color stability and preventing discoloration, and is used for enhancing the appearance such as wood and resistance to ultraviolet rays. In the present invention, the type of the colorant is limited so that coloration does not occur for a long period of time. As the colorant, copper oxide (Cu ₂ O) and iron oxide (Fe ₃ O ₄ ) are mixed at a ratio of 1: 2.5 to 3.5 Powder. That is, conventionally, when coloring only using iron oxide, coloring easily occurs due to ultraviolet rays. However, when copper oxide and iron oxide are used together, the problem of discoloration is solved.

If the amount of the coloring agent is less than 3% by weight, the function as a coloring agent is weak so that discoloration from the wood can not be prevented. When the amount of the coloring agent is more than 7% by weight It is possible to reduce the physical properties of the synthetic wood.

The binder is used to improve the bonding force between plastics, i.e., thermoplastic resin and wood. In principle, wood flakes exhibit a hydrophilic polarity, and plastics have a hydrophobic non-polarity, so the binding strength of the two substances is weak. Thus, the interaction of wood with plastics is greatly improved by the addition of a binder, with new chemical bonds at the interface between the two materials. As such a binder, maleated poly-propylene (MAPP) or the like can be used. The binder enhances the modulus of rupture (MOR) and modulus of elasticity (MOE) of the synthetic deck and assists in dimensional stability, impact strength and dispersal of wood flour. When the amount of the binder is less than 1% by weight, the bonding strength can not be improved. When the amount of the binder is more than 3% by weight, the amount of the binder is excessive, Can be reduced.

The reinforcing agent is used for improving long-term deformation by impact strength, bending strength, thermal deformation temperature and load, and is also used for improvement of lubricity and moisture absorption of wood powder. In the present invention, such a reinforcing agent may be a mixture of titanium dioxide and calcium carbonate, more preferably a mixture thereof in a weight ratio of 1: 1. At this time, the particle size of the reinforcing agent is not limited, and it is sufficient if it is about 10 nm to 30 탆. It is preferable that the reinforcing agent is contained in the synthetic wood composition in an amount of 3 to 5% by weight. If the reinforcing agent is less than 3% by weight, improvement of physical properties and water absorption of the wood fiber are difficult, and if it exceeds 5% by weight, It is because.

In addition to the above-mentioned additives, the synthetic wood composition of the present invention may further contain an antioxidant, a salt resistance, a heat stabilizer, and the like used in the production of general synthetic wood. It can be used irrespective of its kind.

The synthetic wood composition having the above-described structure has an advantage that it can maintain its appearance for a long period of time without being discolored due to an inorganic coloring agent for a long period of time.

In addition, although not mentioned separately in the description of the composition, when the additive is mixed with the wood flour composition and the raw material composition, the additive is prepared by master batch using the raw material composition and then mixed therewith. And therefore, a description thereof has been omitted.

Hereinafter, a method for producing a synthetic wood according to the present invention will be described. In the following description of the production process, the description of the synthetic wood composition is omitted.

The method for producing a synthetic wood according to the present invention comprises: a wood flour composition comprising wood powder, a UV absorber and a wood preservative; A raw material composition comprising a thermoplastic resin and a UV stabilizer; And a binder; and extruding the mixture to prepare a composition in the form of a pellet; a raw material composition comprising a thermoplastic resin and a UV stabilizer; slush; coloring agent; Binder; And a reinforcing agent are mixed and extruded to prepare a pellet-like composition, heating and stirring the two pellet-shaped compositions at a temperature of 150 to 200 ° C, molding the heated and stirred composition .

Wood powder compositions, raw material compositions, binders, lubricants, Reinforcing agent Weighed  step.

First, each material is mixed in a ratio of 50 to 65 wt% of a wood-based composition, 25 to 35 wt% of a raw material composition, 3 to 5 wt% of a lubricant, 3 to 7 wt% of a colorant, 1 to 3 wt% of a binder and 3 to 5 wt% . At this time, a part of the raw material composition is mixed with a lubricant, a colorant, a binder and a reinforcing agent to prepare a pellet-shaped masterbatch, and the remainder is mixed with a wood flour composition and a binder to prepare a pellet- . Since the binder is also used for both master batches, it is appropriately distributed and used.

Wood flour compositions including wood flour, UV absorbers and wood preservatives; A raw material composition comprising a thermoplastic resin and a UV stabilizer; And Binder  Mixing, and extruding to prepare a composition in the form of pellets.

Next, as described above, wood flour compositions comprising wood powder, UV absorbers and wood preservatives; A raw material composition comprising a thermoplastic resin and a UV stabilizer; And a binder are mixed and extruded to prepare a composition in the form of pellets. At this time, the size of the pellet may be about 0.5 to 7 mm, but it is not limited thereto. Here, extrusion conditions and methods of the pellets are in accordance with known methods.

A raw material composition comprising a thermoplastic resin and a UV stabilizer; slush; coloring agent; Binder; And Reinforcing agent;  Mixing, and extruding to prepare a composition in the form of pellets.

Next, a lubricant, a coloring agent, a binder and a reinforcing agent, which are additives, are mixed with a raw material composition and extruded to prepare a composition in the form of a pellet. Here, it is a matter of course that the raw material composition is the same as that used above. The preparation of the pellets in this step also follows a known method, and the size of the pellets may be about 0.1 to 5 mm, but is not limited thereto.

In the present invention, the two steps of preparing the pellet-like composition are separate steps, the order of which is irrelevant, and any step may be performed first.

The two pellet-shaped compositions are heated to a temperature of from 150 to 200 DEG C, Stirring  step.

Next, the two pellet-shaped compositions are sufficiently stirred in an extruder. At this time, the temperature is preferably 150 to 200 DEG C, and the synthetic wood composition, which is gradually unified through the screw in the extrusion molding machine, is transferred to the die. At this time, if the temperature exceeds 200 ° C, discoloration, odor and deterioration of woody components are caused, and volatile substances are released. Therefore, the melting temperature should be lower than 200 ° C.

The heating and stirring time are not limited, and are subject to conditions for molding with a conventional extrusion molding machine.

The heating, Stirred  Molding the composition.

Next, the synthetic wood composition, which is gradually unified through the screw, is transferred to a mold such as a floor material, a railing material, a column material, etc., according to the use as described above. Such a molding method is well known in the field to which this technique belongs, and thus a detailed description thereof will be omitted.

That is, when the synthetic wood composition of the present invention is sufficiently melted and agitated and molded, the UV absorber and UV stabilizer in the composition block ultraviolet rays and prevent discoloration through copper oxide and iron oxide which are inorganic coloring agents.

Hereinafter, specific examples of the present invention will be described in detail.

(Example)

A synthetic wood having a composition ratio of 60% by weight of a wood-based powder composition, 30% by weight of a raw material composition, 3% by weight of a lubricant, 3% by weight of a reinforcing agent, 3% by weight of a colorant and 1%

Here, as the wood powder composition, 99% by weight of wood powder and 0.8% by weight of a UV absorber and 0.1% by weight of a wood preservative were used. As the raw material composition, 99% by weight of PP as a thermoplastic resin was mixed with 1% by weight of a UV stabilizer Respectively.

At this time, the wood powder used was a woody wood powder having a fiber length of 1.0 to 1.2 mm, a size of 30-100 mesh, a length-to-diameter ratio of 3: 1 to 5: 1, and a water content of 2% , 2- (2-hydroxy-5-methylphenyl) benzotriazole as a UV absorber, an amine stabilizer as a UV stabilizer, and IPBC as a wood preservative. As the lubricant, 1% by weight of a mixture of copper oxide and pyridione zinc in a ratio of 1: 1.2 by weight and 2% by weight of paraffin wax were used. As the colorant, copper oxide and iron oxide were mixed in a weight ratio of 1: 3 And titanium dioxide and calcium carbonate as a reinforcing agent in a weight ratio of 1: 1, and as the binder, maleic polypropylene was used.

A part of the lubricant, the reinforcing agent, the coloring agent, and the binder is prepared by using a raw material composition to prepare a pellet-shaped master batch having a size of 0.1 to 5 mm. The master batch is then mixed with a wood powder, And the mixture was heated at 150 to 200 ° C for 30 minutes and stirred. The mixture was extruded into an extruder to produce a continuous plate-type synthetic wood. After cooling the synthetic wood, the surface of the synthetic wood was smoothly processed.

(Comparative Example 1)

As Comparative Example 1, a synthetic wood was produced in the same manner as in Example 1 except that a mixture of 0.5% by weight of a UV stabilizer and 99.5% by weight of PP as a thermoplastic resin was used, and only iron oxide was used as a colorant.

(Test Example 1)

The synthetic wood of Example 1 and the synthetic wood of Comparative Example 1 were subjected to accelerated weathering (Xenon Arc) tests. The accelerated weathering test was conducted by the Korean Institute of Construction & Life Testing and tested according to ASTM G 155: 2013.

At this time, the test conditions of ASTM G 155: 2013 were as shown in Table 1 below.

ASTM G 155 Test Conditions division Operating condition filter Inner filter Type S Borosilicate Outer filter Type S Borosilicate Irradiance Control 0.55 W / m2 at 340 nm Cycle configuration
Light irradiation 102 minutes Light irradiation and water spray 18 minutes Black panel temperature 65 ℃ Relative humidity 50%

The results are shown in Table 2 and Figs. 1 to 4 below.

Results of Test Example 1. Test Items Example 1 Comparative Example 1 Test Methods Accelerated weatherability 200 hours after color difference (ΔE * ab) 2.7 5.8 ASTM G 155

As can be seen from Table 1 and FIGS. 1 to 4, Example 1 according to the present invention had a color difference of 2.7 after 200 hours and Comparative Example 1 had a color difference of 5.8. Respectively.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention.

Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (5)

A wood powder composition comprising wood powder, UV absorber and wood preservative;
A raw material composition comprising a thermoplastic resin and a UV stabilizer;
An additive composition comprising a lubricant, a colorant, a binder and a reinforcing agent,
The wood preservative is 3-iodo-2-propynyl butylcarbamic acid (IPBC)
Wherein the lubricant comprises copper oxide and pyridione zinc in a weight ratio of 1: 1 to 1.2,
Wherein the colorant comprises copper oxide (Cu ₂ O) and iron oxide (Fe ₃ O ₄ ) in a weight ratio of 1: 2.5 to 3.5,
The lubricant is contained in a proportion of 50 to 65 wt%, the raw material composition is 25 to 35 wt%, the lubricant is 3 to 5 wt%, the colorant is 3 to 7 wt%, the binder is 1 to 3 wt%, and the reinforcing agent is 3 to 5 wt%
Said wood flour composition comprising 97 to 99.89% by weight of wood powder, 0.1 to 2% by weight of UV absorber and 0.01 to 1% by weight of wood preservative,
Wherein said raw material composition comprises 99 to 99.5% by weight of a thermoplastic resin and 0.5 to 1% by weight of a UV stabilizer.
delete delete Wood flour compositions including wood flour, UV absorbers and wood preservatives; A raw material composition comprising a thermoplastic resin and a UV stabilizer; And a binder; and extruding the mixture to prepare a composition in the form of a pellet;
A raw material composition comprising a thermoplastic resin and a UV stabilizer; slush; coloring agent; Binder; And a reinforcing agent, and extruding them to prepare a composition in the form of pellets,
Heating and stirring the two pelletized compositions at a temperature of 150 to 200 DEG C,
And molding the heated, stirred composition,
The wood preservative is 3-iodo-2-propynyl butylcarbamic acid (IPBC)
Wherein the lubricant comprises copper oxide and pyridione zinc in a weight ratio of 1: 1 to 1.2,
Wherein the colorant comprises copper oxide (Cu ₂ O) and iron oxide (Fe ₃ O ₄ ) in a weight ratio of 1: 2.5 to 3.5,
Is used in a proportion of from 50 to 65% by weight of the wood-based composition, from 25 to 35% by weight of the raw material composition, from 3 to 5% by weight of the lubricant, from 3 to 7% by weight of the colorant, from 1 to 3% by weight of the binder and from 3 to 5%
Said wood flour composition comprising 97 to 99.89% by weight of wood powder, 0.1 to 2% by weight of UV absorber and 0.01 to 1% by weight of wood preservative,
Wherein the raw material composition comprises 99 to 99.5% by weight of a thermoplastic resin and 0.5 to 1% by weight of a UV stabilizer. delete

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