JP4765033B2 - Method for producing composite granular material - Google Patents

Description

The present invention relates to a composite granule used as a material for various molded products such as building materials and furniture materials, a method for producing the composite granule, and a molded body using the composite granule.

Particle boards, hard boards, MDF, OSB, etc. are provided as wooden boards that are thermo-press-molded by adding thermosetting resin to woody materials such as wood flour, wood chips, etc., but none of them has sufficient water resistance There was a problem.

As a result of various studies to improve the water resistance of this wood-based board, the present inventor, a building material board integrally molded with a wood chip and fine inorganic particles with a thermosetting resin, It has been found that the water resistance is greatly improved as compared with a simple wooden construction material board.

As a general method of forming a wooden board, a wood chip coated with adhesive is sprinkled and deposited on a steel belt or duralumin thin plate with a forming device with a scraping roll to create a mat, which is used for hot pressing. A method of carrying and hot pressing is adopted.

However, with this method, it is easy to handle a relatively homogeneous raw material such as a single wood chip, but a relatively rough and low density wood chip, and an inorganic powder that is narrower and denser than wood chips. Handling a mixture of raw materials, such as granules and thermosetting resins, that have remarkably different properties, easily separates and segregates into the respective fractions during the forming operation, in the hopper or in the transporter, etc. Therefore, there is a problem that it is extremely difficult.

Therefore, in order to obtain a uniform building material board, it is necessary to use a special production facility equipped with a mechanism for solving the above problems, and there is a problem that a general wood board production facility cannot be used. .

The present invention has been made in view of the above technical problem, and even when using general board manufacturing equipment, a composite granule that can form a uniform and excellent water-resistant building material plate, It aims at providing the manufacturing method of a composite granular material, and the molded object using this composite granular material.

A method for producing a composite granule according to the first aspect of the present invention is a method for producing a composite granule that is a material of a molded body, wherein a self-setting phenol resin is added to a wood chip and an inorganic powder, and the phenol Heat kneading at a temperature equal to or higher than the melting temperature of the resin and below the temperature at which the curing reaction reaches a peak, agglomerating and adhering the wood chips and the inorganic powder particles with the molten phenol resin, and then cooling and grinding. Features.
As the phenolic resin, a self-curing phenolic resin that is cured by starting condensation between molecules when a predetermined curing temperature is reached without requiring addition of a new curing agent is employed.
The method for producing a composite granule according to the second aspect of the present invention is a method for producing a composite granule as a material of a molded body, wherein a phenol resin is added to a wood chip and an inorganic powder, and the melting temperature of the phenol resin The wood chips and the inorganic powder particles are heated to the above predetermined temperature to be agglomerated and adhered by the molten phenol resin, and then the phenol resin is B-staged below the predetermined temperature. The phenol resin curing agent is added.

According to the present invention, it is possible to produce a composite granule formed by integrating a wood chip and an inorganic powder granule with a thermosetting resin even when using a general board production facility. By using the hot-pressure molding, a wood chip, an inorganic powder and the like can be uniformly dispersed in the resin, and a molded body having excellent water resistance can be produced.

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

Examples of the wood raw material used for the wood chip according to the present invention include conifers such as cedar, cypress, spruce, fur, and pine, and broad-leaved trees such as hippopotamus, apton, and aspen. Examples of these wood raw materials include logs of the above tree species, raw materials such as thinned wood, scrap wood generated at factories and residential construction sites, waste pallet materials, recycled wood such as building demolition waste materials, etc. It is preferable in terms of effective use of resources. Of these, one or more can be selected and used in combination.

Examples of a processing method using these wooden raw materials as a wooden chip include cutting and crushing, and a shape used in a general particle board is preferably used.

Examples of the inorganic powder particles used in the present invention include solid particles such as calcium carbonate, silica, mica, talc, clay, fly ash, diatomaceous earth, glass powder, and shirasu, and perlite, vermiculite, and shirasu balloon. And foamed particles such as fly ash balloons. Solid particles having a particle size of about several tens to several microns are preferably used, and foamed particles having a size of about several millimeters to several tens of microns are preferably used. Of these, one or more can be selected and used in combination.

In the present invention, the phenolic resin is not particularly limited, but a novolac type phenolic resin is preferably used. Further, as the novolac type phenolic resin, it is desirable to use a powdery, flaky or pellety resin having a melting point of about 70 to 110 ° C. and containing no curing agent (for example, a crosslinking agent).
The curing agent is not particularly limited, and examples thereof include a crosslinking agent. Moreover, as a crosslinking agent, common hexamethylenetetramine, paraformaldehyde, etc. can be used. Below, the case where a crosslinking agent is used as a hardening | curing agent is demonstrated.
In addition, there is a phenol resin that has a self-curing property that cures when heated to a predetermined temperature without the addition of a curing agent, and such a self-curing phenolic resin is employed in the present invention. Of course you can.

Examples of methods for adjusting the composite granular material (hereinafter referred to as “premixed body”) include the following methods. However, the adjustment method is not limited to the following examples.

The wood chip and the inorganic granular material are, for example, about 100 to 150 ° C. when using a phenol resin having a melting point of 70 ° C., for example, at a temperature higher than the melting point of the phenol resin used in advance by an air flow heating device, a heating kneader, a heating burner or the like. Heat to.

This raw material is put into a stirrer, a kneader or the like, and further, a phenol resin is added, and the resin is melted and stirred and kneaded, whereby the wood chips and the inorganic powder particles are melted through the melted resin. Aggregate and adhere.

During this premixing kneading operation, some of the wood chips are crushed and broken into pieces, but by adjusting the shearing force applied during the kneading operation, the aggregates are prepared sufficiently stably under the conditions that the wood chips do not crush excessively. can do.

At this time, if necessary, it is also effective to heat the kneading apparatus in the vicinity of the melting point of the resin in advance to promote the melting of the resin. Moreover, a part of raw material granular material can be previously kneaded, and a new raw material granular material can be added sequentially, and an aggregation state can also be adjusted.

Next, wait until the temperature of these kneaded materials drops below the decomposition temperature (machine temperature) of the cross-linking agent to be used, add the cross-linking agents hexamethylenetetramine and paraformaldehyde, and continue kneading. After the agent is dispersed in the resin, it is taken out from the stirring / kneading apparatus and cooled to prepare a premixed body.
In addition, when a phenol resin in which a curing agent has already been added or a self-curing property by heating is employed, the temperature is equal to or higher than the melting temperature of the phenol resin and the curing reaction does not proceed significantly. It is possible to prepare a composite granule by heating and kneading in the same manner. In general, it is known that a self-curing phenol resin has a peak at 148 ° C. in the reaction between reactive functional groups and methylol phenol, and a peak at 164 ° C. in the formation reaction of dibenzyl ether. Even when other functional groups that react at a lower temperature are introduced, a reaction temperature peak generally exists, but in fact, the reaction proceeds slowly even below such peak temperature. Therefore, the temperature at which the curing reaction here does not proceed remarkably means below the temperature at which the reaction reaches a peak. In the present invention, “remarkably” of “temperature at which the curing reaction does not proceed remarkably” does not necessarily mean a temperature at which the curing rate becomes absolutely slow. The temperature at which the curing reaction does not proceed further on the basis of the reaction temperature peak corresponds to a temperature at which the curing reaction does not proceed significantly.

The premixed body obtained by this operation is compared with a composite granular body in which relatively fine wood chips and inorganic powder bodies are bonded and integrated with a B-stage (hereinafter referred to as uncured) novolac-type phenolic resin. It is obtained as a mixture of uncured phenol resin and a composite granule in a state where inorganic powder particles and / or fine wood chips are attached via the phenol resin on the surface of the rough wood chip. The mixture obtained in this way is the former composite granule when the particle size composition of the wood chip is large, and the latter composite granule when the particle composition of the wood chip is large and the ratio of coarse particles is large. Becomes the main mixture.

The premix body can also be said to be an agglomerate using an uncured novolac phenolic resin as a thermoplastic binder. Those solidified by cooling after melting maintain their state stably, so that this premix is stable under normal conditions, and this agglomerated state can be maintained over a long period of time.

In order to agglomerate these raw materials, it is conceivable to use a liquid resin, but in this case, although there is an advantage that the kneading can be performed without heating, the liquid evaporates or the wood Since the agglomerated state is destroyed and partly returns to the original powder particle state due to absorption by the chip and the like, a stable premix cannot be obtained. This method is therefore undesirable.

The premixed raw material composition is stocked in a storage tank such as a silo or a hopper in that state, and supplied to a spraying device represented by particleboard wood chips by a rotary feeder or screw feeder in multiple times. Then, a mat in which the premixed body is layered is prepared.
Next, the mat is compressed by a high-temperature and high-pressure press, and at the same time, the thermosetting resin is cured. Then, it can be used as a building material through polishing and cutting processes.

The present invention will be described in more detail with reference to the following examples. However, the embodiments of the present invention are not limited to these examples.

[Example 1]
Preparation of premixed body 700 g of dry wood chips obtained from building waste material heated to 120 ° C. in a hot air dryer and prepared to a particle size passing through a 6 mm sieve, and powdered silica with a brane value of 3,800 cm ² / g 223 g, fly ash balloon having a bulk density of 0.45 and an average particle size of about 150 microns (Keiwa Furnace), novolak-type phenolic resin chip (SP-600PB made by Asahi Organic Materials, melting point 80) containing no crosslinking agent 135 g) was charged into a 10 L RCS preparation mixer (manufactured by Enshu Tekko Co., Ltd.) that had been heated to 120 ° C., and stirred at 60 rpm for 120 seconds. When the temperature dropped to 100 ° C. after stirring, 60 g of an aqueous hexamethylenetetramine solution adjusted to a concentration of 40% by weight was added, and the mixture was further stirred for 30 seconds and then discharged from the mixer to prepare a premixed body.

[Comparative Example 1]
Without heating the raw material having the same composition as in Example 1, as a novolak type phenolic resin, powdered SA-100 (Asahi Organic Chemicals, average particle size of about 20 microns, hexamethylenetetramine 15% above SP-600PB) The mixture was added into a 10-liter RCS preparation mixer without stirring and stirred at 60 rpm for 150 seconds and then removed from the mixer to simply prepare a mixture of these raw materials.

The particle size distribution of the obtained primics was measured. The results are shown in Table 1.
As is apparent from Table 1, the fine particle fraction is clearly reduced in the measurement results of the particle size distribution and those obtained as primics. Moreover, when these preparations were put into a beaker and lightly shaken, in the preparation of Comparative Example 1, a phenomenon was observed in which powdered silica and fly ash balloons settled at the bottom and a wooden chip floated at the top. On the other hand, in the preparation of Example 1, although a small amount of fine particles settled on the bottom, the stable dispersion state was maintained as a whole.

For this reason, it is considered that separation / segregation during handling of the raw material composition is greatly reduced by premixing.

When this premixed body is used, since there is little separation and segregation when handling the raw material composition, a molded body can be manufactured by a general molded body manufacturing method. Although the following can be illustrated as a manufacturing method of a molded object, it is not limited to this illustration.

[Example 2]
Production of a molded body by a laboratory premix alone A frame with an inner dimension of 300 mm × 240 mm is placed on an aluminum plate coated with a release agent, and prepared in Example 1 in that frame and stored in an aluminum bat. The premixed body 720 g was spread by hand so as to have a uniform thickness. The frame was removed while lightly pressing with a push lid, and a mat on which the premixed body was laminated in a layered manner was prepared.

An aluminum plate coated with a release agent was placed thereon, inserted into a heat press at 160 ° C., and hot-pressed for 15 minutes at a pressure of about 10 kgf / cm ² . At this time, a 15 mm thickness regulating bar was placed on both sides of the mat to adjust the tightening depth. After hot pressing, the molded body was produced by taking it out of the press and allowing it to cool in the chamber.

[Comparative Example 2]
Production of molded body by dry mixture of raw materials In the same manner as in Example 2, the raw material mixture prepared in Comparative Example 1 was sprayed and laminated to produce a molded body. In this case, the mixture was separated into an inorganic fraction and wooden chips in the aluminum vat during the spraying operation of the raw material mixture. Made a layer.

Comparing the workability between Example 2 and Comparative Example 2, as a result of the spraying test by hand, the premix body did not feel poor sprayability due to segregation and segregation between raw materials during operation, but the raw materials were simply mixed However, the segregation and segregation between the raw materials is severe, and it is considered that there is a problem in applying to a practical production method.

Practically, it is required that it can be sprayed by a mechanism similar to that of a general particleboard sprayer. However, the separation and segregation between raw materials occurs in the hopper of the sprayer, so that uniform and uniform spraying is possible. It will be difficult. On the other hand, the premixed product is considered to be sufficiently dispersible with a general particle board spraying device.

[Example 3] Manufacturing method of a sandwich-shaped molded body in which a premix layer is a core layer and reinforcing layers are arranged on both surfaces A frame having an inner size of 300 mm x 240 mm is placed on an aluminum plate coated with a release agent. First, 70 g of fly ash balloon mixed with 30% by weight of novolak type phenolic resin (SA-100) and 25 g of chopped strand obtained by cutting glass roving (manufactured by Nittobo Co., Ltd., RS-240PR) into 40 mm. One layer is formed, and the 720 g of the premixed body prepared in Example 1 is dispersed and stratified in the same manner as in Example 2 to form a second layer. Further thereon, a third layer was formed in the same manner as the first layer, the frame was removed while lightly pressing with a push lid, and a mat in which the premixed body was sandwiched between glass fiber reinforcing layers was prepared.
An aluminum plate coated with a release agent was placed thereon, inserted into a heat press at 160 ° C., and hot-pressed for 15 minutes at a pressure of about 10 kgf / cm ² . At this time, a 15 mm thickness regulating bar was placed on both sides of the mat to adjust the tightening depth. After hot pressing, the molded body was produced by taking it out of the press and allowing it to cool in the chamber.
An aluminum plate coated with a release agent was placed on the mat, inserted into a hot press at 160 ° C., and hot-pressed for 15 minutes at a pressure of about 10 kgf / cm ² . At this time, an 18 mm thickness regulating bar was placed on both sides of the mat to adjust the tightening depth. After hot pressing, the molded body was produced by taking it out of the press and allowing it to cool in the chamber.
A physical property test of the obtained specimen was performed in accordance with JIS A 5908 (Particle Board). The results are shown in Table 2. It was found that by using the premixed body, almost the same performance as that of the test body by powder mixing can be obtained. Moreover, it turned out that manufacture of the molded object which uses a premix body as a part of structural layer is also attained.

From these results, it became possible to more easily obtain a phenol resin molded article composed of a wood chip and an inorganic powder by premixing.

Claims (2)

A method for producing a composite granular material as a material of a molded body,
A self-curing phenol resin is added to the wood chips and the inorganic powder granules, and the mixture is heated and kneaded at a temperature equal to or higher than the melting temperature of the phenol resin and a temperature at which the curing reaction reaches a peak, and the wood chips and the inorganic powder granules A method for producing a composite granule comprising: agglomerating and adhering to a molten state with the phenol resin in a molten state, and then cooling and pulverizing. A method for producing a composite granular material as a material of a molded body,
A phenol resin is added to the wood chip and the inorganic powder, and the wood chip and the inorganic powder are agglomerated and adhered by heating to a predetermined temperature equal to or higher than the melting temperature of the phenol resin. And then adding a curing agent for the phenol resin so that the phenol resin is B-staged at or below the predetermined temperature.