KR101918651B1 - Synthetic Wood Article Having Enhanced Durability - Google Patents

Abstract

The present invention relates to a synthetic wood molded article having enhanced durability, and specifically, to a synthetic wood molded article including a synthetic wood composition comprising: a waste wood powder having an average particle size of 100 to 600 μm and a moisture content of 5 wt% or less, a chlorinated vinyl chloride resin having a chlorination content of 60 to 70 wt%, a crosslinked acrylic impact modifier having a butyl acrylate content of 80 wt% or more, and an acrylic polymer processing aid having a methyl methacrylate content of 80 wt% or more in a non-crosslinked linear structure.

Description

{Synthetic Wood Article Having Enhanced Durability}

More particularly, the present invention relates to a synthetic wood molded article, which is environmentally friendly, including a waste wood grain and a chlorinated vinyl chloride resin which is a harmless thermoplastic resin, and has improved durability without deterioration of external appearance or strength even when used for a long time in an external environment The present invention relates to a synthetic wood molding body which can be applied to various building materials such as deck material, railings, columns, and flooring.

Synthetic wood is used as exterior material for various construction materials for environment protection and resource recycling. These synthetic timbers have recently been suffering from global warming and urban fan phenomenon, and as a result, they are often twisted, torn, broken and cracked during long-term use. Technological developments related to synthetic wood are continuing to improve this.

A large number of synthetic wood compositions and their manufacturing methods have been known in the past to improve the durability by a method of making such synthetic wood.

Korean Patent Publication No. 10-1292301 discloses a method of improving the strength and durability of a molded article by adding glass fiber to a polyolefin resin which is a composite of polypropylene and polyethylene and then extruding it by re-mixing with wood. In addition, in Korean Patent Registration No. 10-1283502, acrylonitrile butadiene styrene (ABS) resin is added to improve the strength of vinyl chloride resin including horseshoe, and foam molding is performed during extrusion through a foaming agent, And the water content is lowered to improve the water resistance.

In addition, Korean Patent Registration No. 10-1189069 discloses a method for producing a thermoplastic resin composition containing calcium carbonate, a polyethylene / polypropylene mixed thermoplastic resin, a dispersant, an antioxidant, a heat stabilizer and an antimicrobial agent and has excellent strength, weatherability, dimensional stability, flame retardancy, And a fibrous plastic composite material which can be used for a long period of time without changing the product even in an external natural environment, and a manufacturing method thereof.

However, in the above prior art, the polyolefin resin used as a synthetic resin for synthetic wood has a coefficient of linear expansion of 100 ~ 130 × 10 ^-6 / ° C., which is higher than that of other thermoplastic resins. Therefore, contraction / There is a problem in that the synthetic wood of the previously applied synthetic wood is not only highly protuberant but also has various weathering properties due to the poor weatherability of the polyolefin resin. Therefore, various functional additives should be used to overcome the cracks and cracks caused by ultraviolet rays during outdoor use for a long time.

There is a limit to overcome the limitation of the material of the polyolefin resin by the method disclosed in this prior art.

On the other hand, in the case of vinyl chloride resin, the coefficient of linear expansion is 60 to 80 × 10 ^-6 / ° C., which is excellent not only in shrinkage / expansion ratio as compared with polyolefin resin, but also excellent in self-extinguishing property due to weatherability and non- Widely used. However, in the case of vinyl chloride resin, the impact resistance is weak and it is necessary to inject a reinforcing agent to reinforce it. The acrylonitrile butadiene styrene (ABS) butadiene impact modifier disclosed in Korean Patent Publication No. 10-1283502 is particularly vulnerable to weathering, and when exposed to ultraviolet rays for a long period of time, the impact strength, compressive strength and tensile strength of the resin Resulting in a decrease in the strength, and the long-term durability of the synthetic wood is rapidly lowered.

Korean Registered Patent No. 10-1292301 Korean Patent Publication No. 10-1283502 Korean Patent Publication No. 10-1189069

SUMMARY OF THE INVENTION It is an object of the present invention to provide a synthetic wood molding which is environmentally friendly by using waste wood and a harmless thermoplastic resin as main components.

It is another object of the present invention to provide a synthetic wood formed body having excellent durability and improved durability over a long period of time without deterioration of appearance or strength due to long-term use in an external environment.

In order to solve the above-mentioned problems, the synthetic wood molding according to the present invention comprises a wood pulp having an average particle size of 100 to 600 μm and a moisture content of 5% by weight or less and a chlorinated vinyl chloride resin having a chlorination content of 60 to 70% by weight, A crosslinked acrylic impact modifier having a content of 80 wt% or more, and an acrylic polymer processing aid having a methyl methacrylate content of 80 wt% or more in a non-crosslinked linear structure, at 120 to 160 캜 And a synthetic wood composition.

In this case, the degree of polymerization of the chlorinated vinyl chloride resin may be 700 to 1,300.

The acrylic impact modifier may be any one of ethyl acrylate (EA), methyl methacrylate (MMA), styrene (ST), alphamethylstyrene (α-ST), and acrylonitrile .

The acrylic polymer processing aid may be any one selected from the group consisting of ethyl acrylate (EA), butyl acrylate (BA), styrene (ST), alphamethylstyrene (α-ST), and acrylonitrile And may have a weight average molecular weight of 1,000,000 or more.

The synthetic wood molding according to the present invention can provide an environmentally friendly synthetic wood molding by using waste wood and a harmless thermoplastic resin as main components.

It is also an object of the present invention to provide a synthetic wood formed body having excellent durability of synthetic wood and improved durability over a long period of time in an external environment due to no change in external shape or strength and a reduction in strength.

1 is a process drawing showing a process for producing a synthetic wood according to the present invention.

Hereinafter, the present invention will be described in more detail. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

The synthetic wood molding according to the present invention is characterized in that the synthetic wood molding has an average particle size of 100 to 600 탆 and a wood pulp content of 5% by weight or less and a chlorinated vinyl chloride resin having a chlorination content of 60 to 70% by weight, a crosslinking agent having a butyl acrylate content of 80% And a synthetic wood composition comprising an acrylic polymeric impact modifier and an acrylic polymer processing aid having a methyl methacrylate content of 80 wt% or more in a non-crosslinked linear structure at 120 to 160 캜 .

The above-mentioned synthetic wood composition can be used to produce a molded article, which is the same as that shown in Fig.

That is, a synthetic wood composition is prepared by mixing the raw materials of the synthetic wood composition at 120 to 160 ° C, a molded article extruded at 180 to 260 ° C for the synthetic wood composition, a cooling step for cooling the molded article, And a step of surface sanding and cutting the molded product to produce a synthetic wood molded body.

In the present invention, by using waste wood powder as the wood powder, resource recycling and environmentally friendly products can be manufactured. That is, the wood flour can be used after being directly used as pellets, chips, etc. obtained by processing pieces of recycled wood, sawdust, and wood, or may be pulverized and pulverized. The waste wood powder has a particle size of 100 to 600 mu m, preferably 200 to 400 mu m. When the particle size is less than 100 탆, mixing with the raw material is not easy, and when the particle size is 600 탆 or more, the tensile strength and compressive strength of the extrudate are lowered. Therefore, .

The pulverized wood powder is preferably dried and used in a water content of 5 wt% or less. If the moisture content is too high, the moisture content of the wood pulp powder may deteriorate the physical properties of the synthetic wood composition, .

In the present invention, the synthetic resin to be applied to the synthetic wood composition is a chlorinated vinyl chloride resin having a chlorinated content of 60 to 70% by weight. Since the chlorinated vinyl chloride has a linear expansion coefficient of 50 to 60 占^0-6 / 占 폚, it is lower than that of the conventional resin, so that the shrinkage / expansion ratio according to the change in the external temperature can be improved. In addition, it has excellent weatherability and compressive strength, and it has been shown to maintain high flexural strength, tensile strength and impact strength in accelerated weathering quality evaluation.

In order to achieve the object of the present invention, the chlorinated vinyl chloride resin preferably has a chlorine content of 60 to 70% by weight, more preferably 65 to 69% by weight. When the content of chlorine is less than 60 wt%, excellent tensile strength and compressive strength are difficult to expect. When the chlorine content exceeds 75 wt%, high tensile strength and compressive strength can be expected. However, There are difficulties in mass production of products.

In addition, it is preferable that the chlorinated vinyl chloride resin has a degree of polymerization of 700 to 1,300, and it has been found that the excellent bending load strength, tensile strength and impact strength of the synthetic wood can be obtained within the above polymerization degree range. Further, the lower the degree of polymerization in terms of processability in producing synthetic wood, the better the degree of polymerization should not exceed 1,300.

The synthetic wood composition may include an acrylic impact modifier and an acrylic polymer processing aid for improving the physical properties of the waste wood powder and the chlorinated polyvinyl chloride resin as main components, and may further include a composite stabilizer including a lubricant, a stabilizer, and a colorant have. More specifically, the composite stabilizer may be composed of an olefin-based lubricant, a calcium stearate-based lubricant, a calcium / zinc stabilizer, and a colorant as a lubricant.

In one embodiment, the synthetic wood composition comprises 50 to 60% by weight of waste wood, 26 to 34% by weight of chlorinated vinyl chloride resin, 5 to 10% by weight of acrylic impact modifier, 2 to 8% by weight of acrylic polymer processing aid, To 10% by weight.

Wherein the acryl-based impact modifier has a butyl acrylate (BA) content of 80% by weight or more and is selected from the group consisting of ethyl acrylate (EA), methyl methacrylate (MMA), styrene (ST) -ST), and acrylonitrile (AN), or a combination thereof. The acrylic impact modifier can form a core-shell structure of BA and other multimers through crosslinking.

The acrylic impact modifier is preferably used in an amount of 5 to 10 wt%, more preferably 6 to 8 wt% in the synthetic wood composition. When the content of the acrylic impact modifier is less than 5 wt%, desired impact strength and compressive strength can not be obtained. When the content of the acrylic impact modifier is more than 10 wt%, the tensile strength is lowered without further improvement in impact strength.

It is also possible to use acrylonitrile-butadiene-styrene (ABS) resins containing butadiene (BD), acrylonitrile butadiene rubber (NBR), methyl methacrylate-butadiene-styrene ) Resin, styrene-butadiene-styrene (SBS) resin, and chlorinated polyethylene (CPE), or a combination thereof. However, in the case of containing butadiene in the modifier resin, there is a limitation in the use of an external agent due to a decrease in weatherability due to ultraviolet rays, so that it is preferable to use an acrylic impact modifier resin to ensure quality with long-term durability.

In addition, the acrylic polymer processing aid is a resin having a methyl methacrylate content of a non-crosslinked linear structure of 80% by weight or more, and is selected from the group consisting of ethyl acryl lake (EA), butyl acrylate (BA), styrene (ST) (? -ST), and acrylonitrile (AN), or a combination thereof, and has a weight average molecular weight of 1,000,000 or more.

The acrylic polymer processing aid is preferably used in an amount of 2 to 8% by weight, more preferably 4 to 6% by weight, based on the synthetic wood composition. When the content of the processing aid is less than 2% by weight, a desired tensile strength can not be obtained. When the amount exceeds 8% by weight, excellent tensile strength and compressive strength can be obtained, but an increase in manufacturing cost ratio and an increase in extrusion load during melt molding extrusion.

The composite stabilizer may be used in an amount of 5 to 10% by weight. When the amount of the composite stabilizer is less than 5% by weight, discoloration may occur due to resin carbonization during melt molding extrusion, Is not more than 10% by weight, it is not possible to produce a desired synthetic wood molding appearance due to a decrease in extrusion load factor due to an increase in production cost and excessive activity.

The extrusion molding of the composition containing the waste wood powder and the chlorinated vinyl chloride resin causes the reaction of the surface treating compound in the molding step, so that the adhesive strength is improved and the durability is prolonged. Therefore, the synthetic wood molding material of the present invention can be used as a material for a deck material, a railing material, a column material, or a floor material.

In addition, the use of waste wood pulp and chlorinated vinyl chloride resin compound improves the durability by improving adhesion and workability between wood and resin.

For this purpose, the waste wood powder is surface-treated with acryl silane. When the resin compound is prepared by mixing the chlorinated vinyl chloride resin and the alkyl acrylate, the adhesion and the compatibility are greatly increased by injection or extrusion molding. Therefore, Adhesion is maintained with use, and long-term durability is increased. At this time, the content of the waste wood powder in the synthetic wood composition is 50 to 60% by weight, and is quantified based on the wood pulp treated with the acryl silane.

The surface treatment of the waste wood powder may be made in the form of a core-shell by coating the surface of the waste wood powder, but it is not necessary to form a core-shell-like structure particularly if it achieves the object of improving the adhesive strength of the two components , The desired effect can be achieved by the chemical bonding of the surface treatment compound to the entire surface or a part of the surface of the waste wood powder.

Examples of the acrylic silane for surface treatment of the waste wood powder include 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane , 3-methacryloyloxypropyl methyldiethoxy silane, 3-methacryloyloxypropyl dimethoxy silane, and 3-methacryloyloxypropyl diethoxy silane. Further, the surface treatment of the waste wood powder may be carried out by injecting wood powder into an aqueous solution of acrylic silane, mixing and drying.

At this time, the acryl silane is preferably blended in an amount of 10 to 30% by weight based on the total weight of the waste wood powder, and may be appropriately changed depending on the type and density of the waste wood powder. If the content of the acryl silane is too small, the surface treatment is insufficient and the adhesive strength can not be sufficiently secured. If the content of the acryl silane is too large, the acrylic silane remaining unreacted on the surface of the waste wood powder remains, .

In addition, the resin compound to be compounded with the surface treated waste wood component may be composed of the chlorinated vinyl chloride resin and the alkyl acrylate. Preferably, the resin compound is melted in the extrusion or injection molding process and mixed with the waste wood powder, but is homogeneously mixed and molded. Therefore, it is preferable to use a resin compound prepared by mixing a chlorinated vinyl chloride resin and an alkyl acrylate and then heat-treating the resin at a temperature of 100 ° C or less to obtain a semi-cured state and drying the resin.

In the semi-cured state, the chlorinated vinyl chloride resin and the alkyl acrylate partially chemically bond to each other to maintain a certain degree of bonding strength, but not in a polymerized state. Therefore, when heat is supplied in the molding step, And have a state capable of reacting and bonding with the bonded acryl silane.

The alkyl acrylate is preferably one of ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate and ethyl methacrylate. In order to prepare the resin compound, It is preferable to mix the resin and the alkyl acrylate in a weight ratio of 10: 2 to 10: 5. That is, if the content of the alkyl acrylate is too small, the reactivity of the wood powder with the surface-treated acryl silane is not sufficient and the long-term durability can not be secured. If the content of the alkyl acrylate is too high, The adhesive force between the wood powders can not be sufficiently obtained, and the physical properties are deteriorated rapidly.

In addition, the content of the resin compound in the synthetic wood composition may be in the range of 26 to 34% by weight as in the case of using the chlorinated vinyl chloride resin.

In addition, when the surface treated waste wood powder and the resin compound are applied, the remaining components and the content are preferably the same as in the synthetic wood composition.

The surface treated waste wood powder and the resin compound are combined to cause the reaction of the surface treatment compound in the step of extrusion molding, so that the adhesive strength is improved and the durability is prolonged.

In order to confirm the effect of the synthetic wood molding of the present invention, a sample was prepared and evaluated for its physical properties.

The pulverized wood powder was pulverized with an average particle size of 250 mu m into a dryer at 75 DEG C to dry the pulverized wood powder to a moisture content of 2 wt% or less. As the vinyl chloride resin, Hanwha Petrochemical (HC-17) was used as a vinyl chloride (C-PVC) resin having a chlorine content of 67% by weight. A vinyl chloride (PVC) resin having a chlorine content of 57% by weight was an LG Chemical product (LS100H). A polypropylene (PP) resin containing 20% by weight of glass fiber was an LG Chemical product (LUPOL GP2200). The acrylic reinforcing agent (AIM) was an LG Chemical product (IM-812N) and the processing aid was LG Chemical product (PA-950). The butadiene impact modifier (ABS) was a product of KKPC (HR181). The composite stabilizer was a pre-hardening product (SK-1000).

[Example 1]

51% by weight of waste wood particles having an average particle diameter of 250 mu m, 30% by weight of chlorinated vinyl chloride resin, 6% by weight of an acrylic impact modifier, 4% by weight of an acrylic processing aid and 9% by weight of a composite stabilizer were added to a mixer, While maintaining the compounding state for 30 minutes. The compounding composition was melted in an extruder while being temperature-controlled stepwise from 240 DEG C to 180 DEG C, and molded extrusion was performed.

The molded extruded synthetic wood product was cooled step by step through a cooler from 80 ° C to 20 ° C, the surface was sanded to prevent slipping of the synthetic wood, and cut to a required length to produce a deck type synthetic wood product .

[Example 2]

Except that 53% by weight of waste wood particles having an average particle diameter of 250 μm, 32% by weight of chlorinated vinyl chloride resin, 2% by weight of acrylic impact modifier, 4% by weight of acrylic type processing aid and 9% 1.

[Example 3]

Except that 52% by weight of waste wood particles having an average particle size of 250 μm, 31% by weight of chlorinated vinyl chloride resin, 6% by weight of acrylic impact modifier, 2% by weight of acrylic processing auxiliary agent and 9% 1.

[Example 4]

Except that 51% by weight of waste wood particles having an average particle diameter of 250 μm, 28% by weight of chlorinated vinyl chloride resin, 10% by weight of acrylic impact modifier, 2% by weight of acrylic processing auxiliary agent and 9% 1.

[Comparative Example 1]

Except that 51% by weight of waste wood particles having an average particle diameter of 250 占 퐉, 30% by weight of chlorinated vinyl chloride resin, 6% by weight of butadiene impact modifier, 4% by weight of acrylic type processing aid and 9% by weight of composite stabilizer were added to the compounding machine The same procedure as in Example 1 was carried out.

[Comparative Example 2]

Except that 51% by weight of waste wood particles having an average particle diameter of 250 μm, 30% by weight of vinyl chloride resin, 6% by weight of butadiene impact modifier, 4% by weight of acrylic processing auxiliary agent and 9% 1.

[Comparative Example 3]

Except that 51 weight% of waste wood particles having an average particle diameter of 250 占 퐉, 35 weight% of polypropylene resin containing glass fibers, 10 weight% of a butadiene impact modifier, and 4 weight% of an acrylic processing aid were added to a blender, And the same process was used.

[Comparative Example 4]

Except that 53% by weight of waste wood particles having an average particle diameter of 250 μm, 33% by weight of chlorinated vinyl chloride resin, 6% by weight of acrylic impact modifier, 4% by weight of acrylic processing auxiliary agent and 4% 1.

[Comparative Example 5]

Except that 51% by weight of waste wood particles having an average particle diameter of 250 μm, 30% by weight of chlorinated vinyl chloride resin, 2% by weight of acrylic impact modifier, 8% by weight of acrylic type processing aid and 9% 1.

The properties of the synthetic wood prepared in the above Examples and Comparative Examples were measured by the following methods.

The impact strength (kg-fcm / ㎠) was measured using the impact strength measurement method by KS F 3230: 2011 (Impact strength test method for wooden composite composite floor slab).

Tensile strength (kg / ㎠) was measured by tensile strength measurement method by KS F 3006 (Impact strength test method for wooden composite composite floor slab).

The flexural maximum load strength (kg / ㎠) was measured using the flexural strength measurement method by KS F 3230: 2013 (Impact strength test method for wooden composite composite floor slab).

The weather resistance [impact strength] (kg-fcm / ㎠) of the sample was measured by the accelerated weathering method by KS F 3026: 2011 (experimental condition: Xenon Lamp (340 nm) Light 102 min × 63 ° C./cycle, 3,000 hours) Respectively.

The coefficient of linear thermal expansion (1 × 10 -3 / ° C) was measured using the method of measuring the coefficient of linear thermal expansion according to KS F 3126 (Test Method of Stacked Wooden Floor Length Linear Thermal Expansion Coefficient).

Table 1 summarizes the composition ratios of Examples 1 to 4 and Comparative Examples 1 to 5, and Table 2 is a table showing the test results of Examples 1 to 4 and Comparative Examples 1 to 5.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Pulpwood powder 51 53 52 51 51 51 51 53 51 Synthetic resin CPVC 30 32 31 28 30 - - 33 30 PVC - - - - - 30 - - - PP + GF - - - - - - 35 - - Shock
Reinforcing agent AIM 6 2 6 10 - 0 - 6 2 ABS - - - - 6 6 10 - - Processing aid 4 4 2 2 4 4 4 4 8 stabilizator 9 9 9 9 9 9 - 4 9

division unit Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Impact strength Room temperature kg-cm / cm < 2 > 35 18 34 39 40 28 25 20 20 Weatherability kg-cm / cm < 2 > 33 17 32 37 8 7 5 28 19 The tensile strength kg / cm2 1100 1200 380 350 1000 800 670 200 250 Flexural Maximum Load Strength kg / cm2 8200 7800 1600 2800 7500 6700 4200 1600 3500 Coefficient of linear thermal expansion 1 × 10 -3 / ° C. 0.7 0.8 2.3 2.9 1.1 1.8 2.8 4.9 2.7

From the results of Table 2, it was confirmed that the physical properties were improved in Examples 1 to 4 using chlorinated vinyl chloride resin as compared with Comparative Examples 1 to 5 in terms of impact strength, tensile strength, flexural maximum load strength and linear thermal expansion coefficient .

In addition, according to the results of Examples 1, 3 and 4 and Comparative Example 5, when the reinforcing agent is not mixed with 5 to 7% by weight of the total weight of the reinforcing filler according to the embodiment of the present invention, And the coefficient of linear thermal expansion was decreased. In addition, when the butadiene impact modifier was used through Comparative Examples 1, 2 and 3, it was confirmed that the impact strength after the accelerated weatherability test was rapidly lowered. On the other hand, it was confirmed that the impact strength decrease and the ductility were increased even after the accelerated weatherability evaluation by the addition of the acrylic type septic reinforcement.

Comparing Examples 3 and 4 and Comparative Example 5, it was found that the impact strength, flexural strength and coefficient of linear thermal expansion were decreased unless 4 to 6 wt% of the processing aid was mixed with the total weight.

Accordingly, it has been confirmed that a synthetic wood molding improved in durability can be obtained by applying the synthetic wood composition according to the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments and that various changes and modifications may be made therein without departing from the spirit and scope of the invention. Change is possible. Such variations and modifications are to be considered as falling within the scope of the invention and the appended claims.

Claims (4)

26 to 34% by weight of a chlorinated vinyl chloride resin having an average particle size of 100 to 600 占 퐉, 50 to 60% by weight of waste wood particles having a moisture content of 5% by weight or less and a chlorinated content of 60 to 70% by weight, a butyl acrylate content of 80% 5 to 10% by weight of a crosslinked acrylic impact modifier, 2 to 8% by weight of an acrylic polymer processing aid having a methyl methacrylate content of 80% by weight or more of a non-crosslinked linear structure, and 5 to 10% by weight of a composite stabilizer Characterized in that it comprises a synthetic wood composition which is obtained by mixing the raw materials of the synthetic wood composition at 120 to < RTI ID = 0.0 > 160 C. < / RTI >
The method according to claim 1,
Wherein the polymerization degree of the chlorinated vinyl chloride resin is 700 to 1,300.
The method according to claim 1,
The acrylic impact modifier may include one or a combination of ethyl acryl lake (EA), methyl methacrylate (MMA), styrene (ST), alpha methyl styrene (? ST), acrylonitrile Wherein the synthetic wood product is a wood product.
The method according to claim 1,
The acrylic polymer processing aid may include any one or combination of ethyl acrylate (EA), butyl acrylate (BA), styrene (ST), alphamethylstyrene (? ST), and acrylonitrile , And a weight average molecular weight of 1,000,000 or more.

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