JPH0448321B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for manufacturing particle board,
In particular, the present invention relates to a technique for obtaining a particle board that is entirely flexible, has rubber elasticity, and is highly durable. [Prior art] Particle board, which is obtained by hot-pressing wood chips with adhesive, has the characteristics of high utilization of wood resources and the ability to obtain uniform long products.
In recent years, it has been widely used for building materials, furniture materials, automobile interior materials, etc. Conventionally, resin-based adhesives such as urea-based, phenol-based, melamine-based, and isocyanate-based resins have been used as adhesives for manufacturing particle boards (Japanese Patent Laid-Open No. 57-207058).
In some cases, a curing agent may be added to accelerate curing, and when applying the adhesive, it is necessary to apply the adhesive to the entire surface of the small piece so that a layer of minimum thickness is applied. One of the requirements for coating was to apply the product evenly [June 30, 1981, published by Maruzen Co., Ltd., "Wood Industry Handbook", pages 665-701]. Therefore, particle board has completely different properties such as flexibility, elasticity, cushioning properties, and durability, and has almost no application in fields requiring such properties. [Problems to be Solved by the Invention] The present invention is a particle board, in particular, a rubber-like particle board that is flexible, has excellent bending resistance, and has rebound elasticity,
The aim is to provide products with excellent durability. The above and other objects and novel features of the present invention will become apparent from the description herein. [Means to be Solved by the Invention] and [Operation] The present invention provides an adhesive that is copolymerized or copolymerized by an emulsion polymerization method using a monomer having a conjugated double bond as the main composition when manufacturing a particle board made of wood material. A mixed latex obtained by mixing one or more types of synthetic rubber latex obtained by homopolymerization or by replacing a part of the synthetic rubber latex with natural rubber latex is used as the main material, and at least the rubber component in the latex is added to the main material. An adhesive (latex adhesive) containing additives necessary for sulfurization is used, and the latex adhesive is applied in excess of the amount required for adhesion between particle board raw materials. The present invention relates to a method for producing particle board, which comprises applying a latex adhesive to a raw material, and then hot-pressing the raw material coated with a latex adhesive after homing. The effects of the present invention will be briefly explained as follows along with an overview of typical features of the present invention.
That is, in the present invention, when manufacturing particle board, a latex-based adhesive made of synthetic rubber latex or the like having a composition of 70% or more of monomers having conjugated double bonds, which has flexibility and elasticity, is used.
By applying an excessive amount of coating to the wood chips, which are the raw material for particle board, in excess of the amount required to bond between the chips, the necessary adhesive layer is formed between the chips, and the excess amount is The adhesive penetrates into the inside of the chips through a heat-pressing process, making the wood of the chips flexible, and a particle board with rubber elasticity with resilience is obtained.In addition, the vulcanization treatment of the latex adhesive makes it durable. It can also be used to produce particle board similar to rubber products. Next, the structure and operation according to the present invention will be explained in further detail along with preferred embodiments. As the particle board raw material used in the present invention, various materials used for general particle boards can be used. The raw material for particle board is generally referred to as wood chips or particles. In the present invention, it is preferable to use wood chips obtained by cutting or crushing wood as the raw material. The wood chips contain water.
It is preferable to dry it to 10% or less. The latex adhesive used in the present invention is mainly composed of synthetic rubber latex. Examples of the synthetic rubber latex include latexes of butadiene rubber, isoprene rubber, chloroprene rubber, styrene-butadiene rubber (SBR), and acrylonitrile-butadiene rubber. Synthetic rubber latex has a composition of 70% or more of monomers with conjugated double bonds (also called diene bonds), and is obtained by copolymerization or homopolymerization using emulsion polymerization. When used, it imparts flexibility and rubber elasticity to particle board. It turns out that it can be granted. Synthetic rubber latexes have different latex properties and rubber component characteristics depending on the type of monomer having a conjugated double bond or the properties of other copolymerized monomers. Therefore, it has appropriate flexibility to suit the purpose of use, has excellent rebound resilience, and has improved durability, water resistance, heat resistance, and oil resistance, as well as workability and price. It is more preferable to use a mixture of two or more types of rubber latex. A portion of the synthetic rubber latex may be replaced with natural rubber latex. In the present invention, synthetic rubber latex or a mixed latex obtained by mixing this with natural rubber latex as described above is used as the main ingredient, and various additives are added thereto as necessary. In the present invention, a latex adhesive is used, and in order to vulcanize the rubber component in the latex, obtain the necessary vulcanization effect, and give the board durability,
It is preferable to disperse a vulcanizing agent with a vulcanizing effect in the latex. As the vulcanizing agent, commercially available sulfur powder for rubber vulcanization and the like can be used. A vulcanization accelerator or vulcanization aid may be used in combination. Depending on the type of synthetic rubber latex, etc., these alone can have a vulcanizing effect. For example, a vulcanizing aid such as zinc white powder acts as a vulcanizing agent for carboxy group-modified SBR, nitrile rubber, chloroprene rubber latex, and the like. Various types of vulcanization accelerators can be used; for example, thiazole-based commercial products with the product symbol MZ, or dithiocarbamate-based commercial products with the product symbols EZ and PX can be used. I can do it. In the present invention, it is preferable to use an antiaging agent to prevent aging of the latex. Specific examples include phenolic anti-aging agents. In the present invention, when it is necessary to stabilize the latex, it is preferable to use a stabilizer. Examples of this stabilizer include metal soaps, specific examples of which include potassium oleate and potassium rosin acid.
When mixing more than one species, it is effective to add potassium oleate. It is preferable that the vulcanizing agent, vulcanization accelerator, vulcanization aid, and anti-aging agent be well dispersed in water before use. Next, an example of a method for producing a latex adhesive and a preferred range of the amount of the additive used will be shown. The manufacturing order is to put the required latex into a mixer. When preparing a mixed latex, if necessary, 0.5 to 1% of potassium oleate is added to the latex and mixed by stirring. While operating the mixer, add each additive: 1-2% anti-aging agent, 1-5% vulcanization accelerator, 2-3% sulfur, 2-6% zinc white.
Add in the order of % and stir to mix. (The % value indicates the usage ratio (wt) to latex). By completing stirring and mixing, a latex adhesive is obtained. To apply the latex adhesive to particle board raw materials (hereinafter referred to as chips), the chips may be placed in a coating machine called a blender and applied by a spray method. In general, in particle board manufacturing methods, adhesive is applied at a ratio of 15% (wt or less) of the adhesive relative to the chip weight, but in the present invention, the solid content is It is effective to apply 20% or more, and if 30% or more is applied, the particle board can be made even more flexible and has excellent bending resistance and repulsion elasticity. The chips coated with the adhesive are hominated using a general particle board manufacturing method.
This mat of chips is inserted into a hot press and hot pressed. The conditions for hot pressing will vary depending on the shape of the raw material chips, the thickness of the product, etc., but a hot pressing temperature of 120 to 150°C and a pressure of 10 to 30 kg/cm ² are suitable. A portion of the adhesive applied to the chip under hot pressure penetrates into the chip through the many cracks and fissures present in the wood piece, and the amount of penetration becomes particularly large when it is applied in excess. Further, since rubber is thermoplastic, the higher the temperature and the higher the pressing force, the more the amount of penetration increases. The wood quality of the chips changes into soft properties due to the penetration of the rubber component. The rubber component of the adhesive is heated to complete appropriate vulcanization by continuous heating using hot pressure, or by placing it in a separate heating chamber or passing it through a heating device, thereby maintaining the required rubber elasticity and durability. improve. The particle board obtained by the above manufacturing method can be made into a durable particle board product that is flexible and has excellent rubber elasticity and resilience. Also, in order to make this particle board flame retardant,
The manufacturing method of the present invention uses a latex adhesive in which one or more flame retardants such as antimony oxide, halogen compound, and phosphoric acid compound flame retardants are added and dispersed in the above-mentioned adhesive. in accordance with
Particle board can be used as a building material that is flame retardant. It is also effective to add preservatives, waterproofing agents, termiticides, and peeling agents for metal plates. [Example] Next, the present invention will be described based on an example. Example 1 The chips used were wood chips obtained by crushing wood used in the manufacture of general particle boards. Its shape is rod-like, length 4~15m/m, thickness 0.5~
1m/m Both ends are thin wood chips. The adhesive used as a main ingredient was SBR latex copolymerized with a monomer composition of about 75% phthalene and about 25% sterene, with a solid content of 60%, and the additives were in the following formulation.

[Table] The method of manufacturing the adhesive is to first put the entire amount of the main ingredient, SBR latex, into a high-speed stirring mixer, continue stirring, and gradually add the additives in the order shown in the recipe list, uniformly mixing and dispersing them to make the adhesive. Apply adhesive to the chips using a blender.
Spray while rotating the tip. The amount of coating was applied in excess at the following ratio. Wood chips 100 parts Adhesive 75 parts (solid content approximately 45% based on the chips) The applied chips are hommed onto a metal plate and then hot pressed using a hot press. Heat pressure condition is temperature
130℃ pressurizing force 15Kg/cm ² , heat pressure time is product thickness 1
Hot pressure was applied at a rate of 40 seconds per m/m. The product obtained above was a particle board similar to a rubber product that was flexible and had rebound elasticity. Example 2 The same wood chips as in Example 1 were used. The main ingredient of the adhesive, latex, was a mixture of two types, and mixing was performed using a mixer. The proportions were as follows. Polybutadiene latex (solid content 57%) 60 parts Natural rubber latex (solid content 60%) 40 parts Potassium oleate (latex stabilizer) 1 part The above mixture was used as the main ingredient, and additives were mixed therewith. The composition of the drug is as follows.

[Table] The method of mixing each drug was as in Example 1. The adhesive was applied to the chips using a blender, and the adhesive was applied by spraying while rotating the chips. The coating ratio was as follows, and an excessive amount was applied. Wood chips 100 parts Adhesive 83 parts (solid content approximately 48% based on the chips) The applied chips are hommed onto a metal plate and then hot pressed using a hot press. Heat pressure condition is temperature
125℃ pressurizing force 15Kg/cm ² , heat pressure time is product thickness 1
Hot pressure was applied at a rate of 40 seconds per m/m. The resulting product was a particle board that was more flexible and resilient than in Example 1. Example 3 The same wood chips as in Example 1 were used, and the base latex of the adhesive was a mixture of two types, and mixing was performed using a mixer. The proportions were as follows. Chloroprene latex (solid content 60%) 60 parts Polybutadiene latex (solid content 57%) 40 parts Potassium oleate (latex stabilizer) 1 part The above mixture is used as the main ingredient, and additives are mixed therewith. The composition of the drug is as follows.

[Table] Since chloroprene has a vulcanizing effect on zinc white, sulfur was not used.The anti-aging agent and zinc white were used in advance as a 50% aqueous dispersion using the dispersant Demol N. Mix the chemicals to make an adhesive using a mixer. The adhesive was applied to the chips using a blender. Spray application while rotating the chip. The coating ratio was as follows: excessive coating was applied. Wood chips 100 parts Adhesive 65 parts (solid part about 37% of the chips) The applied chips were homed onto a metal plate and then hot pressed using a hot press. Heat pressure condition is temperature
130℃ pressurizing force 15Kg/cm ² , heat pressure time is product thickness 1
Hot pressure was applied at a rate of 40 seconds per m/m. The obtained product was a particle board having almost the same flexibility as in Example 1, but strong repulsion elasticity. Example 4 The same wood chips as in Example 1 were used. The main ingredient of the adhesive, latex, was a mixture of two types, and mixing was performed using a mixer. The proportions were as follows. SBR latex (67% solids) 65 parts (SBR is a copolymer of about 30% styrene and 70% butadiene) NBR latex (48% solids) 35 parts (NBR is about 14% acrylonitrile and about 70% butadiene)
(86% copolymer) The above mixture was used as the main ingredient, and the additive agent was mixed therewith. The composition of the drug is as follows.

[Table] Each agent was mixed according to the method of Example 1, and an adhesive was prepared after mixing was completed. The adhesive was applied to the chips using a blender, and the adhesive was applied by spraying while rotating the chips. The coating amount was applied in excess as shown below. Wood chips 100 parts Adhesive 60 parts (solids content about 36% based on the chips) The applied chips were homed onto a metal plate and then hot pressed using a hot press. Heat pressure condition is temperature
140℃ pressurizing force 15Kg/cm ² , heat pressure time 1m/m thickness
Hot pressure was applied at a rate of 40 seconds per turn. The resulting product had good flexibility and resilience, and a particle board similar to that of Example 1 was obtained. [Effect of the invention] According to the present invention, in the particle board,
In particular, it was possible to obtain a particle board product that is flexible, has rubber elasticity with resilience, and is durable.

Claims (1)

[Scope of Claims] 1. In the production of particle board made of wood chips as raw materials for particle board, copolymerization or copolymerization by emulsion polymerization with a composition of 70% by weight or more of monomers having conjugated double bonds as an adhesive. A mixed latex obtained by mixing one or more types of synthetic rubber latex obtained by homopolymerization or by replacing a part of the synthetic rubber latex with natural rubber latex is used as the main material, and at least the rubber component in the latex is added to the main material. Using an adhesive (hereinafter referred to as a latex adhesive) containing one or more selected from the group consisting of a vulcanizing agent, a vulcanization accelerator, and a vulcanization aid necessary for curing, and applying the latex adhesive to the raw material in excess of the amount required for adhesion between the raw materials of the particle board, and then hot-pressing the raw material coated with the latex adhesive after homing. A unique manufacturing method for particle board. 2. The manufacturing method according to claim 1, wherein the partail board raw material is wood chips obtained by cutting or crushing wood. 3 Synthetic rubber is a monomer with conjugated double bonds70
Claim 1, which has a composition of % or more.
Manufacturing method described in section. 4 The latex adhesive is one or two selected from the group consisting of a vulcanizing agent, a vulcanization accelerator, and a vulcanization aid.
The manufacturing method according to claim 1, which comprises adding one or more kinds of additives. 5 The latex adhesive contains anti-aging agents, stabilizers,
Claim 1, wherein one or more additives selected from the group consisting of a flame retardant, a preservative, a peeling agent for metal plates, a waterproofing agent, and a termiticide are added. manufacturing method. 6. The manufacturing method as set forth in claim 1, wherein the adhesive is applied in excess of 20% by weight or more in terms of solid content based on the weight of the wood chip raw material. . 7. The manufacturing method as set forth in claim 1, wherein the heating operation is continued during hot pressing to complete the vulcanization of the rubber component in the latex adhesive. . 8. The manufacturing method according to claim 1, wherein a finishing operation is performed after hot pressing.