JP2007196420A - Woody resin molding and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a woody resin molding which is formed from a thermoplastic resin and a woody filler and has excellent flame retardation. <P>SOLUTION: In the woody resin molding containing the thermoplastic resin and the woody filler, the woody filler is impregnated with a flame retarder to prepare a flame retardant filler. The specific gravity of the flame retardant filler impregnated with the flame retarder is 1.2-4.0 times as large as the specific gravity of the woody filler before being impregnated with the flame retarder. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wood resin molded article made of a thermoplastic resin and a wood filler, and is used for a wall material, a partition board, a ceiling material, etc. that require flame retardancy, a building material, a surface material of home appliances, etc. It relates to the resin molded body used and cosmetics using the same, and is particularly suitable for applications such as rental apartments, apartments, office buildings, stores, student dormitories, etc., which have a short recycle cycle by renovation, The present invention relates to a decorative material having excellent dimensional accuracy and excellent flame retardancy.

  At present, wood flooring materials are most prevalent as floor materials for indoor floors in buildings such as detached houses. However, it has been pointed out that when it gets wet, it easily swells, cracks, warps and corrodes, and there is a problem in using it in watery places such as bathroom dressing rooms and bathrooms. It has also been pointed out that there are scratch-resistant problems such as dents in office buildings and stores. Therefore, in recent years, a wood resin molded article excellent in water resistance, weather resistance, corrosion resistance, scratch resistance, and strength using a thermoplastic resin and a wood filler as main raw materials has been proposed (for example, Patent Document 1). .

JP-A-9-286880

  However, conventional wood flooring materials and wood resin moldings having excellent durability have a problem of poor flame retardancy. For example, there is a polyolefin resin as a thermoplastic resin used in a wood resin molded body, but the polyolefin resin has low flame retardancy, and therefore the wood resin molded body using the polyolefin resin has low flame retardancy. There was a trend.

  Accordingly, an object of the present invention is to provide a wood resin molded body having excellent flame retardancy in a wood resin molded body comprising a thermoplastic resin and a wood filler.

  The present inventors injected a flame retardant into a wood filler of a wood resin molded article comprising a thermoplastic resin and a wood filler to form a flame retardant wood resin filler, and a flame retardant at that time Intensive study was conducted on the amount of injection.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a wood resin molded article containing a thermoplastic resin and a wood filler, and a flame retardant is injected into the wood filler. The specific gravity of the flame retardant wooden filler after injection of the flame retardant is 1 relative to the specific gravity of the wooden filler before injection of the flame retardant. It was set as the wood resin molding characterized by being 2 times or more and 4.0 times or less.

According to a second aspect of the present invention, a wood resin molded product is characterized in that the flame retardant is a phosphorus flame retardant or a boron flame retardant.

According to a third aspect of the present invention, there is provided a woody resin molded body characterized in that the thermoplastic resin contains a phosphorus flame retardant.

  The invention according to claim 4 is the woody resin molded article according to any one of claims 1 to 3, wherein the thermoplastic resin is a polypropylene resin.

  The invention according to claim 5 is the method for producing a woody resin molded article according to any one of claims 1 to 4, wherein a flame retardant is injected into the wood-based filler material to make it flame retardant. A method for producing a wood resin molded body comprising a step of forming a wood filler material and a step of pulverizing the flame retardant wood filler material to obtain a flame retardant wood filler material.

  The invention according to claim 6 is a method for producing a woody resin molded article according to any one of claims 1 to 4, wherein the wood-based filler material is pulverized into a wood-based filler. Then, a method for producing a wood resin molded article comprising a step of injecting a flame retardant into the wood-based filler to form a flame-retardant wood filler is provided.

  In a wood resin molded article containing a thermoplastic resin and a wood filler, the specific gravity of the flame retardant wood filler after injecting the flame retardant is such that the wood filler before injecting the flame retardant For example, even if the thermoplastic resin used is a polyolefin resin having poor flame retardancy, the wood resin molded product is characterized by being 1.2 times to 4.0 times the specific gravity of Thus, a wood resin molding having excellent flame retardancy can be obtained, and it becomes possible to impart flame retardancy to a wood resin molding such as a wood resin building material having excellent productivity. In addition, it is possible to obtain a wood resin molded body having flame retardancy at a low cost because it is superior in surface hardness and dimensional accuracy than wood building materials having flame retardancy and is excellent in productivity.

  In addition, by making the flame retardant used in the wood-based filler a phosphorus flame retardant or a boron flame retardant, these flame retardants can be added to water or alcohol, or a water / alcohol mixture. Easily dissolves into solutions, and these solutions are excellent in impregnation and permeability, so that the flame retardant can penetrate into the wood-based filler to obtain a wood resin molded article with excellent flame resistance. I was able to.

  Further, since the thermoplastic resin contains a phosphorus-based flame retardant, the thermoplastic resin can be provided with excellent flame retardancy, and is used in combination with the above-described flame-retardant treated wood-based filler. As a result, a wood resin molded article excellent in flame retardancy could be obtained.

  In addition, the thermoplastic resin used is a polypropylene resin, and the water vapor barrier property of the polypropylene resin is excellent, so that the flame retardant agent injected into the wooden filler repeatedly absorbs and releases moisture. It was possible to suppress the elution and precipitation of the flame retardant due to the above, and to maintain the flame retardant performance for a long time.

  In addition, by pulverizing the flame retardant wooden filler after injecting the flame retardant, and making it a flame retardant wooden filler, a method for producing a wood resin molded article, Flame retardant can be placed inside the wood filler by the press-impregnation method, etc. Furthermore, the flame retardant is dried and cured, and at the same time, the wood material is dried. It was possible to easily crush and pulverize the material and the fiber inside it, and it was possible to obtain a uniform wooden filler with a small particle size.

  In addition, by injecting a flame retardant after the flame-retardant wood-based filler is pulverized, and making a flame-retardant wood-based filler, a method for producing a wood resin molded article, The flame retardant agent could easily penetrate into the wooden filler by spraying, and the surface of the wooden filler could be coated with the flame retardant agent.

  Below, the woody resin molding of this invention and its manufacturing method are demonstrated in detail. First, it shows about the injection method of the flame retardant with respect to a wood type filler and a wood type filler. The wood resin molded body in the present invention is a wood resin molded body containing a thermoplastic resin and a wood filler, and is composed of a flame retardant wood filler in which a flame retardant is previously injected. Excellent in properties.

  The wood-based filler material used for the wood-based filler in the present invention may be any general wood, but includes all wood-based fiber structures, and the use of the wood resin molded body Depending on the purpose, for example, kenaf, bagasse, bamboo, or waste paper may be selected.

  These woody resin filler materials are broken by a cutter mill or the like, and this is pulverized by a ball mill or an impeller mill to make a fine powder. Thereby, the drip suppression effect at the time of combustion of a wood resin molding can also be acquired.

  The average particle size of the wooden filler is preferably 10 to 300 μm, and more preferably 50 to 250 μm. Those having an average particle size of less than 10 μm are difficult to handle, and especially when the amount of the wood-based filler is large, if the dispersion in the thermoplastic resin is poor, the machine of the wood-resin molded product to be produced Strength decreases. Moreover, even if larger than 300 micrometers, it is inferior to the homogeneity of a molded article and mechanical strength falls. Furthermore, it is difficult to obtain flatness even in the surface state of the molded product.

  In addition, the wood-based filler referred to here is not limited to the above-mentioned wood flour, but includes all wood-based fiber structures, depending on the purpose of use of the wood resin molded body, For example, you may select kenaf, bagasse, bamboo, or waste paper.

  In the present invention, the type of the thermoplastic resin, the type of the wood-based filler, and the additive added to the thermoplastic resin and the wood-based filler are not limited without departing from the spirit of the present invention.

As the flame retardant previously injected into the wood filler in the present invention, a boron flame retardant and a phosphorus flame retardant can be used. Examples of the boron-based flame retardant include boric acid, borate, borax, and anhydrous boric acid. In particular, borate and borax are preferable because of their excellent solubility in water and alcohol. Can be used. In addition, as the phosphorus flame retardant, red phosphorus, phosphate, polyphosphate, phosphate ester, and the like can be used, and in particular, phosphate is excellent in solubility in water and alcohol. Polyphosphate can be preferably used.

  Boric acid, borax, phosphate, and polyphosphate, of course, have excellent flame retardant effects on wood, but are soluble in water, such as rainwater, moisture, condensation, and water vapor. Depending on the location and place where the treated wood is used, the warranty period cannot be set in the case of residential building materials. was there. Therefore, these flame retardants are not only flame retardant but also have ant and antiseptic properties, and even if they are known to be low toxic to humans, they should be used as wood houses. There was a problem that was difficult.

  However, when acting as a flame retardant for the wood-based filler of the wood resin molded product of the present invention, the wood-based filler containing a flame retardant such as boric acid, borax, phosphate, polyphosphate The flame retardant of the wood resin molding is difficult because it is difficult to elute into water even if there is moisture around the wood resin molding. It is also possible to suppress a decrease in sex.

  The flame retardant injected in advance into the wooden filler is injected into the wooden material as an aqueous solution or an alcohol solution. The amount of injection of the flame retardant into the wood resin molding is relative to the specific gravity of the wooden filler before injection of the flame retardant, relative to the specific gravity of the flame retardant wooden filler after injection of the flame retardant. However, it is necessary to be 1.2 times or more and 4.0 times or less. When the specific gravity of the flame retardant wood-based filler after the injection of the flame retardant is less than 1.2 times the specific gravity before the injection, the wood resin molded product cannot obtain sufficient flame retardancy. In addition, even if the flame retardant is injected into the wood filler so that the specific gravity of the flame retardant wood filler after injection of the flame retardant exceeds 4.0 times, the flame retardant further exceeds this. Can't get. Therefore, it is necessary to make it 10 times or less from the viewpoint of manufacturing cost. In addition, the specific gravity of the wood-based filler in the present invention needs to be measured after sufficiently drying and removing the solvent.

  Next, an injection method for injecting the flame retardant into the wooden filler will be described. The injection method for injecting the flame retardant into the wood filler is to add a flame retardant to the wood filler material before crushing when the wood filler material is crushed into a wood filler. There are a method of injecting and a method of injecting a flame retardant into the wooden filler after crushing.

  In the method of injecting a flame retardant into the flame retardant wood-based filler material before crushing, the flame retardant is injected into a piece of wood molded into a plate shape or crushed into chips. At this time, injection processing can be performed by an arbitrary method such as impregnation or spray coating using an aqueous solution or alcohol solution obtained by dissolving a flame retardant in water or alcohol. Moreover, you may pressurize at this time. Moreover, in order to improve the chemical | medical agent injection | pouring efficiency to a wooden material, after drying a wooden material, the above-mentioned chemical | medical solution is inject | poured and it can dry again after that and the method of fixing a flame retardant chemical | medical agent inside can be used.

  The moisture content of the wood in which the flame retardant has been injected by these methods has decreased, and the moisture content is approximately 2 to 5%, depending on the size of the wood before the impregnation treatment. The wood material infused with a flame retardant having a significantly reduced moisture content has a significantly reduced strength, and is easily pulverized and pulverized. Therefore, the particle size of the wood filler impregnated with the flame retardant can be made smaller and uniform, and a wood resin molded article having excellent flame retardancy and moldability can be obtained.

In the method of injecting a flame retardant into the flame retardant wooden filler material before crushing, the flame retardant is injected after the flame retardant wooden filler is pulverized. A wood filler, such as wood powder or cellulose powder, previously ground to a desired particle size can be arbitrarily selected. These pre-pulverized wood-based fillers have a large surface area, and the flame retardant can be easily injected into the wood filler by spray-coating or mist-coating an aqueous solution or alcohol solution of the flame retardant. Can do.

  Furthermore, not only can the flame retardant agent be easily injected into the wood-based filler by spraying or the like, but flame retardant properties can be efficiently obtained with a smaller amount of agent addition. Furthermore, the surface of the wooden filler can be coated with a flame retardant, a flame retardant leaching inhibitor, a compatibilizer with a thermoplastic resin during molding, or the like. As a result, a woody resin molded body having further excellent flame retardancy and moldability can be obtained.

  Next, a wood resin molded article using a flame retardant wood filler will be described.

  Examples of the thermoplastic resin used for the woody resin molded body in the present invention include polyolefin, polystyrene, polyester, polyamide, polyvinyl alcohol, polycarbonate, polyacryl, polypinyl chloride, polylactic acid and other biodegradable resins. Appropriate selection from resin is possible. These resins may be used alone or in a mixture of several kinds. In particular, polyolefin resins and polylactic acid resins can be preferably used in consideration of performance such as generation of dioxins during incineration, outflow of environmental hormone substances during landfilling, and durability.

  Examples of the polyolefin include polyethylene, polypropylene, polybutene, polyisoprene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-α olefin copolymer, propylene-α olefin copolymer, ethylene-ethyl acrylate copolymer. Polymers, those obtained by acid modification for the purpose of improving adhesiveness, ionomers and the like can be selected as appropriate, and they may be single or mixed.

  Examples of the biodegradable resin include polyhydroxybutyrate, polybutylene succinate, polybutylene succinate, polycaprolactone, cellulose acetate, polyesteramide, vinyl acetate, copolyester, polylactic acid, A starch-based one can be appropriately selected, and a single type or a mixture of plural types may be used.

  These thermoplastic resins can be selected as appropriate, but in order to satisfy performance such as generation of dioxins during incineration, outflow of environmental hormones during landfilling, weather resistance and heat resistance as members, resistance to chemicals and solvents, etc. It is desirable that the thermoplastic resin is a polypropylene resin.

  In addition to being excellent in dimensional stability and material recyclability, polypropylene is free of environmental hormones during incineration, such as vinyl chloride resin, and the polypropylene resin has excellent water vapor barrier properties. The flame retardant injected into the system filler can suppress elution and precipitation of the flame retardant due to repeated moisture absorption and release, and the flame retardant performance can be maintained for a long period of time. That is, it can be set as the wooden resin molding which can maintain a flame retardance performance for a long term.

  Also, it is preferable to add a flame retardant to the thermoplastic resin. Flame retardants for thermoplastic resins include inorganic compounds such as aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, etc., but these are relatively inexpensive materials that can be used as fillers. There is no particular limitation. However, if halogen-containing resins such as vinyl chloride resin are not used in consideration of the environment, use of flame retardants containing halogenated flame retardants and heavy metals such as antimony compounds is not recommended. It is necessary to consider.

  Moreover, you may use a phosphorus-type flame retardant as a flame retardant contained in a thermoplastic resin. Examples of phosphorus flame retardants include phosphates, phosphate esters, red phosphorus, and melamine phosphate. Among these, phosphates and phosphates are preferable because they have flame retardancy by forming a foam heat insulating layer with respect to various thermoplastic resins. In particular, when polyolefin resins such as polyethylene and polypropylene, which are generally flammable, are used as the thermoplastic resin, it is extremely difficult to add 3 to 5% by weight of a flame retardant with respect to these polyolefin resins. A flame effect is obtained. Therefore, a wood resin molded article having excellent flame retardancy can be obtained by using together with the wood filler that has been flame-treated with the flame retardant injected into the wood filler.

Furthermore, in terms of recyclability, wood recycling building materials such as MDF and particle board often use thermosetting resins, so it is difficult to recycle materials again, but resins made of thermoplastic resin and wood fillers. In building materials, it is easy to recycle the raw materials again as a raw material of the woody resin molding of the present invention or to a press board of recycled materials.

  The kneading of the wood filler and the thermoplastic resin is not particularly limited, but a method of kneading with a Banbury mixer and pelletizing with a pelletizer or a method of mixing and pelletizing with a twin screw extrusion kneader are common. Further, if the wood-based filler has a high moisture content, foaming may be caused during pelletization. Therefore, the moisture content is preferably suppressed to 8% or less in advance by a dryer or a hopper dryer before kneading.

  The wood filler and the thermoplastic resin are kneaded and then extruded to form a wood resin molded body. In the present invention, since a flame retardant for wood is contained inside the wood-based filler, so-called filler bulk can be reduced with respect to the thermoplastic resin, and the moldability can also be improved. It is also possible to improve the degree of freedom of product shape and productivity.

  After the wood chips are dried in an oven to a specific gravity of about 0.3, a flame retardant containing an aqueous solution of sodium borate as a main component is injected and impregnated and dried. This impregnation and drying was repeated three times to produce a flame retardant wood chip having a specific gravity of about 0.5. This flame retardant impregnated wood chip was pulverized to a particle size of 200 μm to produce flame retardant wood flour. Moreover, the wood resin molded product of the present invention having a plate shape of 900 mm in length, 150 mm in width, and 5 mm in thickness was formed by a profile extrusion molding method according to the following composition.

<Composition of wood resin molding>
Polypropylene resin 49 parts by weight Flame retardant impregnated wood powder (average particle size 200 μm) 25 parts by weight Talc 10 parts by weight Baking soda-citric acid chemical foaming agent 3 parts by weight Condensed phosphate ester flame retardant 13 parts by weight

  The wood is dried to a specific gravity of about 0.3 and then pulverized to a particle size of about 200 μm. The wood flour is impregnated with an aqueous flame retardant containing ammonium phosphate as a main component and then dried again. 5 flame retardant impregnated wood powder was produced. From this, the wood resin molded product of the present invention having a plate shape of 900 mm in length, 150 mm in width, and 5 mm in thickness was molded in the same manner as in Example 1 by the profile extrusion molding method.

<Composition of wood resin molding>
Polypropylene resin 49 parts by weight Flame retardant impregnated wood powder (average particle size 200 μm) 25 parts by weight Talc 10 parts by weight Baking soda-citric acid chemical foaming agent 3 parts by weight Condensed phosphate ester flame retardant 13 parts by weight

<Comparative Example 1>
In place of the flame retardant impregnated wood powder of the blend of the wood resin molded body of Example 1, a wood part that has not been impregnated with the flame retardant is used, and the wood resin molded body is molded in the same manner as in Example 1. did. The raw material wood of wood flour and the particle size of wood flour are the same as in Example 1.

<Composition of wood resin molding>
Polypropylene resin 49 parts by weight Wood flour (average particle size 200 μm) 25 parts by weight Talc 10 parts by weight Baking soda-citric acid chemical foaming agent 3 parts by weight Condensed phosphate ester flame retardant 13 parts by weight <Comparative Example 2>

  The same wood powder as in Comparative Example 1 was used, and 25 parts by weight of boric anhydride was added to the wood as a wood flame retardant, and a wood resin molded article was molded in the same manner as in Example 1.

<Composition of wood resin molding>
Polypropylene resin 49 parts by weight Wood flour (average particle size 200 μm) 20 parts by weight Talc 10 parts by weight Sodium bicarbonate-citric acid chemical foaming agent 3 parts by weight Condensed phosphate ester flame retardant 13 parts by weight Boric anhydride 5 parts by weight A resin molded body was molded.

<Performance comparison>
About the said Example 1 thru | or Example 3 and the comparative example 1 thru | or the comparative example 3, the flame retardance was evaluated. The flame retardancy was evaluated by the 45 ° Meckel burner method of JIS A1322. The results are shown below.

Example 1 Flameproof Class 1 Example 2 Flameproof Class 1 Comparative Example 1 Less than Flame Class 3 Comparative Example 2 Flame Class 3

Claims (6)

In a wood resin molded article containing a thermoplastic resin and a wood filler, a flame retardant wood filler in which a flame retardant is injected into the wood filler,
The specific gravity of the flame retardant wooden filler after injecting the flame retardant is from 1.2 times to 4.0 times the specific gravity of the wooden filler before injecting the flame retardant. Characteristic wood resin molding.   The wood resin molded article, wherein the flame retardant is a phosphorus flame retardant or a boron flame retardant.   The woody resin molded article, wherein the thermoplastic resin contains a phosphorus flame retardant.   The woody resin molded article according to any one of claims 1 to 3, wherein the thermoplastic resin is a polypropylene resin.   A method for producing a woody resin molded article according to any one of claims 1 to 4, comprising a step of injecting a flame retardant into a wood-based filler material to form a flame-retardant wood filler material, and the flame retardant And a process of pulverizing a porous wood filler material to form a flame retardant wood filler material.   A method for producing a woody resin molded body according to any one of claims 1 to 4, wherein the wood-based filler material is pulverized into a wood-based filler, and the wood-based filler is made flame-retardant. A method for producing a wood resin molded article, comprising a step of injecting an agent to form a flame retardant wood filler.