KR20170133720A - Manufacturing method of wood-plastic composites without carbonization and wood-plastic composites manufactured thereby - Google Patents

Abstract

The present invention relates to a method of producing a wood-plastic composite without carbonization, and a wood-plastic composite produced thereby, wherein the method comprises: mixing thermoplastic resin chips and silicone oils without wood flour; adding wood flour having a water content of 0.05% or less thereto; and performing injection molding or extrusion molding below 220C. Specifically, by mixing the thermoplastic resin chips and the silicone oils first, and then adding the wood flour having a water content of 0.05% or less to the mixture to be mixed therein prior to kneading, the present invention induces a uniform dispersion of the components, and thus prevents carbonization. Accordingly, the wood-plastic composite produced by the method of the present invention exhibits excellent moldability, impact resistance, and color development by comprising the thermoplastic resin, the wood flour, and the silicone oils in an appropriate ratio.

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a wood-plastic composite material free from carbonization, and a wood-plastic composite material produced by the method and a wood-

The present invention relates to a method for producing a wood-plastic composite material free from carbonization and a re-plastic composite material produced thereby. More specifically, the present invention relates to a method for producing a wood- Plastic composite material which is free from carbonization and which is subjected to injection molding or extrusion molding at a temperature lower than 220 ° C by adding wood powder to wood-plastic composites.

Wood-plastic composite (WPC), which is made by adding wood powder to thermoplastic synthetic resin, is recyclable and environmentally friendly. Such a wood-plastic composite material is required to uniformly disperse the wood powder and the synthetic resin so as to be closely adhered to each other to obtain sufficient physical properties.

However, since the surface of wood powder is hydrophilic and the synthetic resin is hydrophobic, the combination of wood and synthetic resin is difficult, and various additives are added. At this time, when the moisture content of the wood powder is high, the performance of the additive is deteriorated. Since the carbonization phenomenon and the gas (bubble) are generated in the manufacturing process, it is necessary to strictly control the water content (water content) of the wood powder.

In order to solve this inconvenience, Korean Patent No. 10-1175308 discloses an invention in which the amount of water contained in wood flour is not precisely controlled by adding an alkaline earth metal nano-oxide, but the alkaline earth metal oxide has a nano-scale size It is cumbersome and costly to prepare.

Therefore, it is necessary to develop a method capable of improving the physical properties of a wood-plastic composite material without the need to add materials such as alkaline earth metal nano-oxides.

Korean Patent No. 10-1175308

The present inventors have found that when the water content of wood flour is made to be lower than a specific value and the silicone oil which is an active agent in the manufacturing process is first stirred with the thermoplastic resin chip and then the wood flour having a water content of 0.05% And that the physical properties of the wood-plastic composite material are improved, thereby completing the present invention.

Accordingly, an object of the present invention is to provide a method for producing a wood-plastic composite material having excellent physical properties.

Another object of the present invention is to provide a wood-plastic composite material produced by the above-mentioned production method.

In order to accomplish the object of the present invention, the present invention provides a method for producing a kneaded product, comprising the steps of: a) stirring a thermoplastic resin chip and a silicone oil; b) mixing the kneaded mixture having a water content of 0.05% And c) injecting or extruding the mixture, which has been stirred in step b), at a temperature of less than 220 캜. The present invention also provides a method for producing a wood-plastic composite material.

In the step a), 100 parts by weight of the thermoplastic resin chip and 0.3 to 1 part by weight of the silicone oil are stirred.

The wood powder in the step b) is 2 to 20 parts by weight based on 100 parts by weight of the thermoplastic resin chip.

The wood powder in step b) may be selected from the group consisting of combs, sawdust, paper powder, pulp, coffee sludge, wood chips, and combinations thereof.

The particle size of the wood powder in the step b) may be 10-100 mesh.

The thermoplastic resin in step a) may be selected from the group consisting of polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyamide (PA), polystyrene (PS), cellulose acetate (CA), cellulose acetate propionate May be selected from the group consisting of thermoplastic elastomers (TPE), thermoplastic polyurethanes (TPU), thermoplastic silicon vulcanates (TPSiV), and combinations thereof.

The wood flour in step b) may be a dyed dye.

According to another aspect of the present invention, there is provided a wood-plastic composite material produced by the above-described method, which comprises 100 parts by weight of a thermoplastic resin, 0.3 to 1 part by weight of a silicone oil and 2 to 20 parts by weight of wood powder .

The present invention relates to a method for producing a thermoplastic resin composition, which comprises first mixing a thermoplastic resin chip with a silicone oil and then adding wood powder having a water content of 0.05% or less, stirring the mixture, and kneading the same to induce uniform dispersion of components to prevent carbonization and gas The wood-plastic composite material having excellent moldability, impact resistance and color developing ability can be provided by including wood powder and silicone oil in an appropriate amount.

Hereinafter, the present invention will be described in detail.

The present invention relates to a method for producing a resin composition, comprising the steps of: a) stirring a thermoplastic resin chip and a silicone oil; b) mixing and agitating wood powder having a moisture content of 0.05% or less in the mixture stirred in step a) Molding the mixture at a temperature lower than 220 deg. C, and extruding the mixture.

a) stirring the thermoplastic resin chips and the silicone oil is a step of uniformly coating the silicone oil on the surface of the thermoplastic resin chip by stirring only the thermoplastic resin chips and the silicone oil without wood powder.

The silicone oil is an external lubricant and has an effect of reducing the frictional force generated on the contact surface with the thermoplastic resin and the processing machine to improve the releasability of the molded product and the fluidity of the resin in the molding process. The carbonization phenomenon may occur due to frictional force. If the content of the silicone oil is sufficient, even if the content of the silicone oil is not uniformly distributed on the surface of the thermoplastic resin chip, the carbonization phenomenon occurs when the injection molding or extrusion molding is carried out. Therefore, the thermoplastic resin and the silicone oil must be stirred evenly, .

In addition to silicone oil, external lubricants include higher fatty acids, fatty acid amide compounds, and waxes. However, when these materials are included as external activators, their color development ability is much worse than silicone oil.

The amount of the silicone oil is preferably 0.3 to 1 part by weight based on 100 parts by weight of the thermoplastic resin chip. If the content of the silicone oil is less than 0.3 part by weight, the resin does not function properly as a lubricant, so that the releasability of the wood-plastic composite material and the fluidity of the resin in the molding process are reduced. As a result, Not only the impact strength is deteriorated, the impact resistance is remarkably deteriorated, but also carbonization phenomenon occurs. When the content of the silicone oil is more than 1 part by weight, it is inefficient because there is not a large difference in effect from the addition of 1 part by weight.

The thermoplastic resin may be, but not limited to, polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyamide (PA), polystyrene (PS), cellulose acetate (CA), cellulose acetate propionate CAP), thermoplastic elastomer (TPE), thermoplastic polyurethane (TPU), thermoplastic silicon vulcanate (TPSiV), and combinations thereof.

b) mixing the wood mixture having a moisture content of 0.05% or less with the mixture stirred in the step a), stirring the mixture, and kneading the mixture, wherein the water content of the wood powder is 0.05% or less is injection molding or extrusion molding in step c) As a technical element to prevent carbonization and gas (bubbles) from occurring, it has very important critical significance. The water content of the wood powder may be 0.01% or less.

In exterior grade woods, the term "DRY" means a rule that reduces the moisture content of wood of the highest grade or near zero, ie Clears, Industrial Clears, Selects & Finish grades to a maximum of 15% or less. Timber processed to this standard is usually stamped with MC15, but may also be labeled S-DRY. In the case of Board, Merchantable & Common grades with apparent knots, the maximum water content up to 19% is acceptable as "DRY".

Considering this, the water content of 0.05% is extremely extreme, and many trials and errors have been made since it was impossible to imagine at the initial stage of technology development. However, through many experiments, it is impossible to prevent the carbonization phenomenon unless it is ultimately dried to less than 0.05%. If wood powder having a water content of less than 0.05% is used, it is completely bonded with the synthetic resin, I found that I could make a product with almost the same properties, and finally I could complete the invention.

In summary, the present invention relates to a technique in which a thermoplastic resin chip and a silicone oil are first stirred so as to be sufficiently uniformly mixed, and then wood powder is separately added and stirred, as described in the above a) and b) By the combination of the techniques set to below% by weight, the occurrence of carbonization and bubbles is completely blocked.

The carbonization phenomenon not only causes deterioration of properties but also causes a problem that molding is not performed properly, so prevention of carbonization is a very important technical problem in the related art. Particularly, since the wood-plastic composite material is often used as an accessory part, the formability is very important, and thus it is particularly important to prevent the carbonization phenomenon when manufacturing the wood-plastic composite material for accessory parts. At the same time, it is very significant that it has been implemented with synthetic resin products that do not mix wood flour in terms of physical properties.

As such, the present invention finds the 'moisture content of wood flour' which has a threshold value of 0.05% which is difficult to imagine by those skilled in the art, without any additional substances, and precisely applies it simultaneously, We have developed a technology that can be maintained. This invention has been tried by those skilled in the art, but no one has actually added wood that can be applied to handicrafts, so that it is possible to use wood plastic that has no carburization and no deterioration in properties, It is a very breakthrough invention in that it could be solved.

The content of wood flour in the step b) is preferably 2 to 20 parts by weight based on 100 parts by weight of the thermoplastic resin chip. When the content is less than 2 parts by weight, the color of the original color or the color of the dye is not properly developed. When the content of the wood powder is more than 20 parts by weight There is a defect on the surface, the impact resistance is extremely weakened, the wood is not properly dispersed in the thermoplastic resin, and the color rendering power also deteriorates. When the content of wood flour exceeds 20 parts by weight, this phenomenon occurs because the surface of the wood flour is hydrophilic and the property of the thermoplastic resin is hydrophobic. If the content of wood flour exceeds the content of wood flour, the bonding between the wood flour and the thermoplastic resin becomes weak. Therefore, in order to produce a wood-plastic composite material without a binder, it is preferable that the wood powder content is 20 parts by weight or less based on 100 parts by weight of the thermoplastic resin chip.

The wood flour may be selected from the group consisting of gypsum, sawdust, paper powder, pulp, coffee sludge, wood chips, and combinations thereof, and preferably it may be sawdust. In addition, the size of the wood powder particle is not limited thereto, but it may be 10-100 mesh, and preferably 20-70 mesh. If the particle size is less than 100 mesh, the particles may be too fine to express the color when dyed wood is colored. If the particle size is larger than 10 mesh, it is difficult to pass through the extruder or the extruder. It can not be done properly.

In addition, if the size is more than 10 mesh, the mixture of the synthetic resin and the wood powder can not be integrated, and a region having the texture of the wood powder itself can be formed on the surface of the molded product, which causes a defect in which the wood powder portion is preferentially eroded do.

The wood powder may be a dye-dyed wood, and the wood-plastic composite material may be imparted with various colors through dyeing. The dye may be, for example, a direct dye, a metal complex acid dye, a useful dye, a basic dye, a mordant fuel, a reactive dye, a natural dye, and the like, as long as it includes a component capable of dyeing wood powder. From the viewpoint of environment friendliness, it may preferably be a natural dye. Examples of the natural dyes include black, brown, yellow, purple, cochinil, red, Lac, and Indigo.

On the other hand, in the kneading step of the step b), the gel state mixture in which the wood particles are uniformly distributed in the thermoplastic resin can be made by heating. The temperature of the warming step can be appropriately selected and set by the user depending on the type of the thermoplastic resin used, and may be specifically 70 to 120 ° C.

c) In the step of injection molding or extrusion molding at a temperature lower than 220 캜, the temperature of injection molding or extrusion molding is preferably less than 220 캜, and when the temperature is more than 220 캜, Carbonization phenomenon may occur. The molding temperature may preferably be 120 ° C or more to less than 220 ° C, more preferably 150 ° C to 215 ° C or 150 ° C to 200 ° C.

Combinations of the methods of steps a), b) and c) described above can completely prevent carbonization and gas evolution. Even if the wood flour is added after the thermoplastic resin chips and the silicone oil are first stirred, carbonization phenomenon and gas are generated when the water content of the wood flour exceeds 0.05%. Even if the water content of the wood flour is less than 0.05%, the thermoplastic resin chips and the silicone oil are stirred first Carbonization phenomenon occurs when injection molding or extrusion molding is carried out after stirring at the same time with the wood. In addition, the molding temperature must be less than 220 占 폚.

The present invention provides a wood-plastic composite material produced by the manufacturing method according to the present invention and comprising 100 parts by weight of a thermoplastic resin, 0.3 to 1 part by weight of a silicone oil and 2 to 20 parts by weight of wood powder. The technical significance of the above components and their contents is the same as described for the above production method, and a description thereof will be omitted.

Although the wood-plastic composite material according to the present invention is not limited in the field of use, it can be preferably used for the production of accessories, and specifically, can be used for manufacturing eyeglass frames, watch frames, automobile parts, shoes, toys and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood that the scope of the present invention is not limited by these examples in accordance with the gist of the present invention, and it is to be understood by those skilled in the art that the present invention is not limited thereto It will be obvious.

≪ Preparation of Examples and Comparative Examples >

Examples and Comparative Examples in Tables 1 to 3 below were prepared using thermoplastic resin (polyethylene) chips, silicone oil and sawdust (size: 20 to 50 mesh).

In order to prepare Examples and Comparative Examples having the structures shown in Tables 1 and 2, a thermoplastic resin chip and a silicone oil were first stirred to coat the surface of the thermoplastic resin chip with silicone oil, followed by addition of sawdust Lt; / RTI > Thereafter, the mixture was kneaded at 100 占 폚 and injection molded at 180 占 폚.

Production of Examples and Comparative Examples in which water content of wood flour was set differently (unit: parts by weight) ingredient Example Comparative Example One 2 One 2 3 4 sawdust content 10 10 10 10 10 10 Moisture content (%) 0.01 0.05 0.1 0.5 0.6% 0.7% Silicone oil 0.65 0.65 0.65 0.65 0.65 0.65 Thermoplastic resin 100 100 100 100 100 100

(Unit: parts by weight) of the examples and comparative examples in which the contents of the components were set differently. ingredient Example Comparative Example 3 4 5 6 5 6 7 8 9 sawdust content 2 20 10 10 One 25 10 10 10 Moisture content (%) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Silicone oil 0.65 0.65 0.3 One 0.65 0.65 0.1 1.5 - Thermoplastic resin 100 100 100 100 100 100 100 100 100

Further, Examples and Comparative Examples were prepared by changing the production method as shown in Table 3 below. Example 7 and Comparative Example 10 in Table 3 are the same in composition as Example 2 in Table 1 above.

Production of examples and comparative examples in which the production method was performed differently Manufacturing method Example 7 a) premixing the thermoplastic resin chip with silicone oil and stirring for 30 minutes
b) adding sawdust and stirring for 30 minutes, followed by injection molding at 180 < RTI ID = 0.0 > Comparative Example 10 a) adding all the thermoplastic resin chips, silicone oil and sawdust, stirring for 1 hour, and injection molding at 180 캜

<Experimental Example>

Experimental Example 1. Carbonization and bubble generation observation

The above Examples and Comparative Examples were observed to see if carbonization occurred during injection molding. The results are shown in Table 4 below.

Carbonization phenomenon occurred (occurred: ○, not generated: ×) Example Comparative Example One 2 7 One 2 3 4 7 9 10 × × × ○ ○ ○ ○ ○ ○ ○

In Table 4, it can be seen from the results of Examples 1 and 2 and Comparative Examples 1 to 4 that the moisture content of sawdust (wood powder) is preferably 0.05% or less in order to prevent carbonization, and Comparative Examples 7 and 9 , It can be seen that the carbonization phenomenon occurs when the silicone oil is not added or only 0.1 part by weight is added.

The results of Example 7 and Comparative Example 10 show that, instead of stirring the thermoplastic resin chip with the silicone oil and the sawdust at once, the method of mixing the thermoplastic resin chip with the silicone oil and then adding the sawdust prevents the carbonization As shown in Fig. That is, if thermoplastic resin chips, silicone oil, and sawdust are put in one time and stirred and then injected at a high temperature, carbonization phenomenon occurs because the components are not mixed uniformly.

In addition, it was observed whether or not &quot; bubbles &quot; were formed in the injection molded article, and the results are shown in Table 5 below.

Bubble occurrence (occurrence: ○, not occurring: ×) Example Comparative Example One 2 One 2 3 4 × × ○ ○ ○ ○

From the results shown in Table 5, it can be seen that bubbles are not formed in the molded article when the water content of the wood powder is 0.05% or less.

Experimental Example 2. Measurement of physical properties

The physical properties of the examples and comparative examples in Table 2 were measured, and the results are shown in Table 6 below. As shown in Table 6 below, when the amount of sawdust is 1 part by weight (Comparative Example 5), the amount of sawdust is too small to exhibit color development, so that it can not function as a design. When the amount of the sawdust is 25 parts by weight (Comparative Example 6), defects are formed on the surface and the impact resistance becomes very weak. As a result of defects on the surface, color development can not be performed properly. The thermoplastic resin is hydrophobic, because the amount of sawdust is too large to properly bond the sawdust and the thermoplastic resin.

In Comparative Example 9, in which no silicone oil was added at all, and Comparative Example 7, in which 1 part by weight of silicone oil was added, the content of silicone oil was too low and kneading was not properly performed. The impact resistance was remarkably weakened, and the color development remarkably deteriorated.

On the other hand, in Comparative Example 8 in which 1.5 parts by weight of silicone oil was added, there was no significant difference in physical properties from Example 6 in which 1 part by weight of silicone oil was added. Therefore, it is understood that the upper limit of the silicone oil is 1 part by weight.

Physical property measurement result Property evaluation items Example Comparative Example 3 4 5 6 5 6 7 8 9 Surface defect Good Good Good Good Good Bad Bad Good Bad Impact resistance 0 0 0 0 0 4 4 0 5 Sensory Evaluation of Color Expression 4.3 4.6 4.1 4.2 1.9 3.1 2.5 4.1 2.3

1. Surface defects (moldability) : 'poor' when the surface is not smooth, 'good' when the surface is smooth,

2. Impact resistance : After making the examples and the comparative examples, they were dropped at a height of 1.5 m at a height of 5,

3. Evaluation of sensory evaluation of color: The average value (1 point: very poor / 2 points: poor / 3 points) of the result of sensory evaluation of 23 panelists to see whether sawdust was uniformly dispersed in the thermoplastic resin, : Normal / 4 points: Good / 5 points: Very good)

Claims (8)

a) stirring a thermoplastic resin chip and a silicone oil;
b) mixing and stirring the wood powder having a water content of 0.05% or less in the mixture stirred in the step a), and then kneading; And
c) injection molding or extrusion molding the mixture stirred in step b) at a temperature of less than 220 캜.
The method according to claim 1,
Wherein the step a) stirs 100 parts by weight of the thermoplastic resin chip and 0.3 to 1 part by weight of the silicone oil.
The method according to claim 1,
Wherein the wood in step b) is 2 to 20 parts by weight based on 100 parts by weight of the thermoplastic resin chip.
The method according to claim 1,
Wherein the wood in step b) is selected from the group consisting of combs, sawdust, paper powder, pulp, coffee sludge, wood chips, and combinations thereof.
The method according to claim 1,
Wherein the particle size of the wood powder in step b) is 10 to 100 mesh.
The method according to claim 1,
Wherein the thermoplastic resin in step a) is selected from the group consisting of polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyamide (PA), polystyrene (PS), cellulose acetate (CA), cellulose acetate propionate Wherein the thermoplastic elastomer is selected from the group consisting of a thermoplastic elastomer (TPE), a thermoplastic polyurethane (TPU), a thermoplastic silicon vulcanate (TPSiV), and combinations thereof.
The method according to claim 1,
Wherein the wood in step b) is wood powder dyed with a dye.
A wood-plastic composite produced by the manufacturing method of claim 1, comprising 100 parts by weight of a thermoplastic resin, 0.3 to 1 part by weight of a silicone oil and 2 to 20 parts by weight of wood flour.