JP2019188648A - Precursor for wood flow-molding and molding method thereof - Google Patents

Abstract

To provide a precursor for wood flow-molding obtained by impregnating a woody material with thermosetting resin, which is capable of improving moldability due to decrease of deformation resistance of the woody material in wood flow-molding using the thermosetting resin, by modifying the woody material itself.SOLUTION: In a precursor for wood flow-molding obtained by impregnating a woody material with thermosetting resin, the woody material is impregnated with not only the thermosetting resin but also at least one of an oxidized polyalkylene wax and an acid-modified polyalkylene wax being a lubricant composition.SELECTED DRAWING: Figure 4-1

Description

  The present invention relates to a wood fluid molding precursor (prepreg) and a molding method thereof, and more particularly to a wood fluid molding precursor in which a wood material is impregnated with a thermosetting resin and a molding method thereof.

  In recent years, it has been proposed to use a wood-based material impregnated with a thermosetting resin or a thermoplastic resin as a molding material in place of plastic (for example, see Patent Document 1).

The present applicant has found a phenomenon in which massive wood impregnated with such a thermosetting resin or thermoplastic resin is fluidized under specific conditions, and fluid molding of wood-based materials as a molding technique using the same. Has been working on development.
In this processing method, macroscopic large deformation can be given at a relatively high speed by accumulating the relative positional change (slip deformation) of microscopic cells constituting the wood.
In addition, fluid molding using a thermosetting resin or thermoplastic resin as an additive to control slip deformation between cells and joining after deformation has been attempted so far, which is more complicated than compression technology, which is an existing technology. It has been shown that a product having a simple shape and a high strength product can be obtained with high productivity (for example, see Patent Documents 2 to 3).

JP 2012-206300 A JP 2014-166711 A JP2015-95819A

  By the way, as a problem for practical application of flow molding of such a wood-based material, improvement of moldability by reducing the deformation resistance of the wood-based material can be mentioned, but in particular, the wood flow using a thermosetting resin In molding, there are problems such as an increase in deformation resistance due to resin curing, an increase in molding load due to non-uniform deformation, molding defects, and an increase in mold load.

In order to improve this moldability, we have studied lubricants and mold release agents, and applied these materials to the mold, so that in wood flow molding using thermosetting resin, The results of reduction of friction coefficient and improvement of deformability in flat plate compression have been obtained.
However, when a greater degree of deformation is required, it has been found that a sufficient effect cannot be obtained only by applying a lubricant or a release agent to the mold.

  In view of the problems of the wood flow molding using the thermosetting resin, the present invention reduces the deformation resistance of the wood material in the wood fluid molding using the thermosetting resin by modifying the wood material itself. It is an object of the present invention to provide a wood fluid molding precursor obtained by impregnating a thermosetting resin into a wood-based material that can be improved in moldability and a molding method thereof.

  In order to achieve the above object, the wood fluid molding precursor of the present invention is a wood fluid molding precursor obtained by impregnating a wood-based material with a thermosetting resin, and a lubricant composition together with the thermosetting resin. A wood material is impregnated with at least one of a certain oxidized polyalkylene wax and acid-modified polyalkylene wax.

In this case, the lubricant composition can be filled mainly in the lumens of the cells of the woody material.
Here, “mainly filled in the lumen of the cell of the woody material” means that the lubricant composition is filled in the lumen of the cell of the woody material, and a part of the lubricant composition is on the surface of the cell wall. It means to adhere.

  Moreover, an oxidized polyethylene wax can be used for the oxidized polyalkylene wax.

  An acid-modified polypropylene wax can be used as the acid-modified polyalkylene wax.

In addition, a substance having a melting point that is the same as or lower than the curing temperature of the thermosetting resin can be used for the lubricant composition.
Here, “the same or lower temperature than the curing temperature of the thermosetting resin” is not particularly limited, but specifically, the melting point of the lubricant composition is the thermosetting resin. The temperature can be about 0 to 60 ° C., preferably about 1 to 30 ° C., more preferably about 1 to 10 ° C. lower than the curing temperature.

Further, the molding method of the wood fluid molding precursor of the present invention is a molding method of a wood fluid molding precursor in which the wood material is impregnated with a thermosetting resin, wherein the wood fluid molding precursor is The molding is performed at a temperature higher than the curing temperature of the thermosetting resin using a molding die.
Here, “higher than the curing temperature of the thermosetting resin” is not particularly limited, but specifically, about 1 to 20 ° C. from the curing temperature of the thermosetting resin, preferably, The temperature can be increased by about 1 to 10 ° C, more preferably about 1 to 5 ° C.

  According to the wood fluid molding precursor and molding method therefor of the present invention, the wood material is impregnated with the thermosetting resin and at least one of the oxidized polyalkylene wax and the acid-modified polyalkylene wax as the lubricant composition. Therefore, the lubricant composition added (internally added) to the wood-based material exudes from the interior of the wood-based material during molding, thereby functioning as a lubricant and in the wood fluid molding using a thermosetting resin. The formability can be improved by reducing the deformation resistance of the wood-based material.

It is explanatory drawing which shows the metal mold | die used by the moldability evaluation of the precursor for woody fluid molding of this invention. It is explanatory drawing which shows the addition amount-weight increase rate of the oxidation polyethylene wax of the phenol resin impregnation wood prepared by the 30% density | concentration used by the same moldability evaluation, and a tangential T direction swelling rate. It is a cross-sectional enlarged photograph of the prepared wood used for the same formability evaluation. It is explanatory drawing which shows the outline and result of a thermal analysis of the prepared wood used by the same moldability evaluation. It is explanatory drawing which shows the punch load F-punch stroke S diagram in the side extrusion experiment of the phenol resin impregnation wood prepared by the 30% density | concentration used by the same moldability evaluation. It is explanatory drawing which shows the punch load F-punch stroke S diagram in the side extrusion experiment of the phenol resin impregnation wood prepared by the 30% density | concentration used by the same moldability evaluation. It is explanatory drawing which shows the result of the same moldability evaluation. It is explanatory drawing which shows the result of the same moldability evaluation. It is explanatory drawing which shows the result of the same moldability evaluation. It is explanatory drawing which shows the result of the same moldability evaluation. It is explanatory drawing which shows the result of the same moldability evaluation. It is explanatory drawing which shows the addition amount-weight increase rate of the oxidized polyethylene wax of the melamine resin impregnation wood prepared by 30% density | concentration used by the same moldability evaluation, and a tangential T direction swelling rate. It is explanatory drawing which shows the addition amount-weight increase rate of the melamine resin impregnation wood prepared by the 30% density | concentration used by the same moldability evaluation-weight increase rate, and a tangential T direction swelling rate. It is explanatory drawing which shows the outline and result of a thermal analysis of the prepared wood used by the same moldability evaluation. It is explanatory drawing which shows the outline and result of a thermal analysis of the prepared wood used by the same moldability evaluation. It is explanatory drawing which shows the punch load F-punch stroke S diagram in the side extrusion experiment of the melamine resin impregnation wood prepared by the 30% density | concentration used by the same moldability evaluation. It is explanatory drawing which shows the punch load F-punch stroke S diagram in the side extrusion experiment of the melamine resin impregnation wood prepared by the 30% density | concentration used by the same moldability evaluation. It is explanatory drawing which shows the result of the same moldability evaluation. It is explanatory drawing which shows the addition amount-weight increase rate of the acid-modified polypropylene wax of the phenol resin impregnation wood prepared by the 30% density | concentration used by the same moldability evaluation, and a tangential T direction swelling rate. It is explanatory drawing which shows the punch load F-punch stroke S diagram in the side extrusion experiment of the phenol resin impregnation wood prepared by the 30% density | concentration used by the same moldability evaluation. It is explanatory drawing which shows the result of the same moldability evaluation. It is explanatory drawing which shows the outline and result of a thermal analysis of the prepared wood used by the same moldability evaluation.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a wood fluid molding precursor and a molding method thereof according to the present invention will be described with reference to the drawings.

  When a wood fluid molding precursor is produced by diffusing a synthetic resin in a wood material, in particular, it is possible to diffuse the synthetic resin in the tissue of the wood material, more specifically, in the cell wall. It has been found to be extremely important for imparting fluid formability to wood based materials.

Therefore, the wood fluid molding precursor of the present invention is based on impregnating a wood-based material with a thermosetting resin, and further impregnating the wood-based material with a lubricant composition together with the thermosetting resin. ing.
Thereby, the thermosetting resin can be filled in the cell wall of the wood material, and the lubricant composition can be filled mainly in the lumen of the cell of the wood material. In addition, the lubricant composition fills the cell lumen of the wood-based material, and a part thereof adheres to the cell wall surface.
Here, the addition amount of the thermosetting resin and the lubricant composition impregnated and added (internally added) to the wood-based material is not particularly limited, but specifically, the wood-based material (raw material). 1 to 100 parts by weight of a thermosetting resin, 1 to 50 parts by weight of a lubricant composition, preferably 5 to 80 parts by weight of a thermosetting resin, and 5 to 40 parts of a lubricant composition. Part by weight, more preferably 10 to 50 parts by weight of the thermosetting resin and 10 to 30 parts by weight of the lubricant composition.

  In the present invention, the woody material refers to a lignocellulosic material containing lignin, hemicellulose, and cellulose, and herbs can be used in addition to wood. Specifically, wood such as cedar, hinoki and beech, and herbs such as kenaf, corn, sugar cane, hemp, rush and rice can be used. In addition to new materials, waste materials such as house demolition, furniture demolition, wood chips, thinned wood, rice husk, wood flour, waste paper, pruned branches, cut grass, fallen leaves, sugarcane pressed bagasse Can be used. Further, it is possible to use a mixture of high-quality waste paper having a low lignin content and lignin discharged as waste in the pulping process. Also, two or more of the above materials can be used in combination.

In addition, as the thermosetting resin, a thermosetting resin conventionally used as an impregnation material of a wood material in a fluid molding process of a wood material, for example, a resol type phenol resin (hereinafter simply referred to as “phenol resin”). And various resins such as a melamine resin, a urea resin, an epoxy resin, and a polyurethane resin can be used.
Here, for these thermosetting resins, it is preferable to use a substance having a curing temperature higher than or equal to the melting point of the lubricant composition used together.
These thermosetting resins are usually composed of a combination of a main resin and an auxiliary agent, and are used by impregnating the wood-based material in fluid molding processing of the wood-based material, so that they are dissolved in water. It is also desirable to have a dispersed form.
Further, the combination of the main resin and the auxiliary agent is not particularly limited as long as the thermosetting reaction of the main resin proceeds, but the affinity with cellulose, hemicellulose, lignin, etc., which are the main components of the woody material. It is preferable to use a compound having a property, and it is particularly preferable to use a compound having affinity with an OH group.
As the thermosetting resin, not only one kind of the above-mentioned ones but also a plurality of them can be used in combination.

  As the lubricant composition, an oxidized polyalkylene wax or an acid-modified polyalkylene wax can be used.

  Here, the oxidized polyalkylene wax includes those in which a carboxyl group or a hydroxyl group is added to the polyalkylene wax skeleton by a method such as air oxidation, and the acid-modified polyalkylene wax includes, for example, polyalkylene wax, , Modified products such as maleic acid modified, fumaric acid modified, itaconic acid modified and the like. Further, the polyalkylene skeleton of the oxidized polyalkylene wax or the acid-modified polyalkylene wax is not particularly limited, but the polyalkylene having a repeating unit of 2 to 6 carbon atoms, particularly 2 to 3 carbon atoms as alkylene. Examples thereof include polyethylene, polypropylene, and ethylene-propylene copolymer.

  The essential component of the oxidized polyalkylene wax and the acid-modified polyalkylene wax are not particularly limited, but preferred examples include oxidized polyethylene wax and acid-modified polypropylene wax.

  By the way, these lubricant compositions, that is, the oxidized polyalkylene wax and the acid-modified polyalkylene wax, can be used in combination of not only one type but also a plurality thereof.

Of these oxidized polyalkylene waxes and acid-modified polyalkylene waxes, those having a number average molecular weight of about 1,000 to 200,000 and a melting point of 70 to 180 ° C. are desirable, and more preferably, the number average molecular weight is 1500 to 16000. Those having a melting point of 80 to 170 ° C. are desirable. If the molecular weight of the wax is extremely small, a sufficient viscosity effect (load supporting effect) may not be exhibited. Conversely, if the molecular weight is extremely large, friction may increase due to viscous resistance. Further, the melting point of the lubricant composition is preferably the same as or lower than the curing temperature of the thermosetting resin so that the lubricant composition functions sufficiently as a lubricant.
Here, “the same temperature as or lower than the curing temperature of the thermosetting resin” is not particularly limited, but specifically, the melting point of the lubricant composition is the thermosetting resin. The temperature can be lower by about 0 to 60 ° C, preferably about 1 to 30 ° C, more preferably about 1 to 10 ° C.

  In one embodiment of the lubricant composition to be used, among the oxidized polyalkylene wax or the acid-modified polyalkylene wax, the oxidized polyalkylene wax further has a melting point of 80 to 150 ° C., an acid value of 5 to 40 mgKOH / g, several An oxidized polyethylene wax having an average molecular weight of about 1500 to 5500, particularly about 2500 to 5500, and an acid-modified polyalkylene wax having a melting point of 105 to 180 ° C., an acid value of 1 to 90 mgKOH / g, a number average molecular weight of about 5000 to 200000, Particularly preferred are acid-modified polypropylene waxes of about 10,000 to 60,000.

  In the lubricant composition, the wax component as described above is usually blended in a form dissolved or dispersed in an organic solvent and / or water. In the present invention, the lubricant composition is a wood-based material. In this fluid molding process, it is desirable to use a form dissolved or dispersed in water since it is used by impregnating a woody material.

The solvent or dispersion medium of the lubricant composition is not particularly limited, and various types can be used, but sufficient solubility or uniform dispersibility with respect to the wax component can be exhibited. Furthermore, it is preferable that it can be evaporated or volatilized and removed at least under the processing conditions (temperature, pressure) during fluid molding, and specifically water or an aqueous dispersion medium mainly composed of water can be preferably used.
In this way, in the embodiment in the form of a dispersion in which wax is dispersed using water or an aqueous dispersion medium mainly composed of water, the organic solvent volatilizes in the atmosphere during fluid molding. It is desirable because it does not pollute the work environment.

  The concentration (at the time of impregnation) of the oxidized polyalkylene wax or acid-modified polyalkylene wax in the lubricant composition in the form of a dispersion is particularly sufficient if it has sufficient fluidity to be used by impregnating the woody material. Although not limited, in general, for example, 0.1% by mass to 20% by mass, preferably 0.2% by mass to 15% by mass, and more preferably 0.5% by mass to 10% by mass. %. If the concentration is low, sufficient effects cannot be exhibited. If the concentration is high, the impregnation property to the wood-based material may be lowered.

  The lubricant composition used in the present invention comprises, as described above, an oxidized polyalkylene wax and / or an acid-modified polyalkylene wax as an essential component, and an embodiment in which the wax is incorporated alone in the composition. However, as a matter of course, in another embodiment, other general lubricating additives can be blended as optional components in the lubricant composition. Other typical lubricating additives typically include fats and oils such as animal and vegetable oils, fatty acids, fatty acid salts, esters, amines, sulfur compounds, phosphorus compounds, silicone compounds, and the like. Other than that, it doesn't matter. Examples of silicone compounds include silicone oils, silicone waxes, organopolysiloxanes partially or wholly modified with alkyl groups, aralkyl groups, carboxyl alkyl groups or carboxylic acid alkyl groups, hydroxyalkyl groups, aminoalkyl groups, etc. Can be used.

  The blending amount of these other lubricants in the lubricant composition used in the present invention is such that fluidity and release properties are improved by the oxidized polyalkylene wax and / or acid-modified polyalkylene wax as essential components. There is no particular limitation as long as the properties are not impaired.

  Furthermore, in the embodiment in which the lubricant composition used in the present invention is an aqueous dispersion, that is, an emulsion system, other additives such as various surfactants, dispersion stabilizers, and rust inhibitors are included in the composition. It is also possible to blend. The addition amount of these other additives in the embodiment of the emulsion system is not particularly limited.

And the shaping | molding method of the precursor for wood fluid shaping | molding of this invention shape | molds the said precursor for wood fluid shaping | molding using a shaping | molding die under high temperature rather than the curing temperature of thermosetting resin.
Here, “higher than the curing temperature of the thermosetting resin” is not particularly limited, but specifically, about 1 to 20 ° C. from the curing temperature of the thermosetting resin, preferably, The temperature can be increased by about 1 to 10 ° C, more preferably about 1 to 5 ° C.

  As a result, the lubricant composition added (internally added) to the wood-based material exudes from the interior of the wood-based material during molding by impregnating the wood-based material with the lubricant composition together with the thermosetting resin. Therefore, it functions as a lubricant and decreases the deformation resistance of the wood-based material in the wood flow molding using a thermosetting resin, thereby increasing the deformation resistance due to resin curing and increasing the molding load due to uneven deformation, molding failure, It is possible to eliminate or reduce problems such as an increase in mold load and improve moldability.

  Hereinafter, regarding the woody fluid molding precursor of the present invention and the molding method thereof, a phenol resin (hereinafter sometimes referred to as “PF resin”) as a thermosetting resin, and an oxidized polyethylene wax (hereinafter referred to as “PF resin”) as a lubricant composition. Examples that are performed using “PEOwax” may be described.

1. 1. Material and Experimental Method 1.1 Woody Material and Preparation Conditions As woody material (raw material), a cedar veneer having a thickness of about 3.0 mm (fiber L direction: 160 mm × tangential T direction: 100 mm, bulk density 0.35) 0.41 g / cm ³ ) was used.
30% by weight phenol resin (PF resin) (“Aikane Resin PX341” manufactured by Aika Kogyo Co., Ltd., weight average molecular weight of about 380) aqueous solution (this aqueous solution is also expressed as “30% PF” or “PF (30%)”) PEOwax (emulsion system) in a predetermined amount (0, 0.01, 0.05, 0.1, 0.5, 0.9, 1.5, 3, 6, 9% by weight) An aqueous solution of PF resin and PEOwax added with A was prepared and impregnated into a cedar veneer.
Here, the used PEOwax is as follows.
<Oxidized polyethylene wax>
Melting point: 138 ° C
Acid value: 30 mg KOH / g
Number average molecular weight: 2900
In addition to the simple mixing and stirring method, the aqueous solution is prepared by adding ultrasonic vibration (40 kHz, 10 minutes), for example, if necessary, to increase dispersibility when the amount of PEOwax added is large. To. Ultrasonic vibration was applied using a BRANSON 8500 series.
In addition, the impregnation treatment is performed at room temperature by the reduced pressure pressurization impregnation method. As shown in Table 1, the degree of treatment is the ratio of weight increase to dry weight (WPG), the amount of change in post-treatment dimensions relative to dry dimensions Organized by ratio (BR).
In addition, with the addition conditions of PEOwax 1.5, 3, 6, and 9%, the addition amount of the PEOwax to the woody material is 6.5 parts by weight with respect to 100 parts by weight of the dry weight of the woody material (raw material), It became 11.1 weight part, 19.1 weight part, and 29.4 weight part.

WPG and BR varied under the influence of the material density, but the correlation with the density was the determination coefficient R ² = 0.97 and 0.69, respectively.

1.2 Differential scanning calorimetry and dynamic viscoelasticity measurement Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) are performed to change the thermal properties of wood-based materials. I investigated.
Here, differential scanning calorimetry (DSC) uses Q200 made by TA instrument, and dynamic viscoelasticity measurement (Dynamic mechanical analysis (DMA)) makes thermomechanical device TMA made by Seiko Instruments. / SS-6000 Viscoelastic mode was used.
The effect of PEOwax on the softening and hardening behavior of PF resin-impregnated wood was examined.
The sample was taken from the inside of about 1 mm from the end.

1.3 Side Extrusion Mold and Formability Evaluation An outline of the mold used in the formability evaluation is shown in FIG.
This mold is composed of a square-head punch, a die, and a base plate (all made of SKD11).
The die has a gap between the 26 × 26 mm ² container portion into which the material is charged and the mirror surface portion where the wooden material is extruded sideways after compression (t = 1.2 mm: extrusion ratio 21.7, CrN coating) ) Is provided.
The side extrusion mold was heated by heat conduction from a hot platen, and the temperature at the place where the base plate and the material were in contact was set to 150 ° C. In the evaluation, the test was performed without applying a lubricant or the like.
About 5 g of wood-based material prepared as described in 1.1 (equivalent to 4 pieces: humidity control with a relative humidity of 65%) is cut and put into a mold heated to a predetermined temperature in advance, and a punch is immediately inserted. Pressure was applied up to a load of 100 N, and the state was maintained for 2 minutes (material preheating). The punch stroke S at this time was set as the start point (S = 0). It arranged so that the tangential direction of the woody material with high fluidity could be the extrusion direction. After heating the material, pressurization was performed to a target load of 50 kN at a punch speed of 2.0 mm / min, and a load F-punch stroke S diagram at that time was obtained.
Since the side extrusion behavior changes depending on the preparation conditions of the wood-based material, the extrusion start load F (punch surface pressure P = F / 26 ² ), the extrusion length le, and the like were evaluated as moldability evaluation items.

2. 2. Experimental results and discussion 2.1 Interaction between PEOwax and PF resin-impregnated wood Figure 2-1 shows the addition amount of oxidized polyethylene wax to phenol resin-impregnated wood prepared at a concentration of 30% -weight increase rate and tangential T-direction swelling rate ( Hereinafter, it may be simply referred to as “swelling ratio”).
As shown in FIG. 2-1, when a phenol resin prepared at a concentration of 30% is used as the thermosetting resin and the amount of PEOwax added is increased to 1.5 to 9.0%, the weight increase rate increases. It was confirmed that the tangential T direction swelling rate decreased.

Here, the tangential T direction swelling rate will be described.
Since wood is an orthotropic material, it is necessary to define the direction (surface) of interest when discussing physical properties. In general, the direction in which an annual ring is formed on the end surface of the tree with the tree extending direction as the fiber direction (L) and the L direction as a perpendicular is defined as the radial direction (R), and the tangential direction (T) with respect to the annual ring is defined. Surfaces formed by the main shafts (L, R, T) are referred to as plate (LT) surfaces, grids (LR), and throat (RT) surfaces, and the swelling rate of the single plate (plate) sample in the direction of the main axis The change occurs at a ratio of L: R: T≈1: 5: 10. This rate of change is derived from the cell structure, and since the rate of change is greatest in the tangential T direction, it is convenient to discuss the state of entry of substances into the cell wall.

The experimental method is to measure the tangential length (T0) of a cedar veneer that has been dried to a constant weight at 105 ° C., and prepare it by depressurization and pressure impregnation treatment in the preparation solution (solute + wax insoluble content + solvent). The liquid was injected and impregnated. Thereafter, the cedar veneer was taken out from the preparation solution, dried (finally dried at room temperature under reduced pressure (not heated)), and the length T when the mass became a constant weight was measured. At this time, if the solute is infiltrated into the cell wall during the impregnation and drying, the cell wall is swollen, while the wax-insoluble matter cannot be infiltrated into the cell wall and is deposited on the cell wall surface.
The weight increase rate is a value indicating the mass ratio of the introduced substance regardless of the inside or outside of the cell wall, and the swelling ratio is a value indicating the ratio of the introduced substance to the cell wall.
Accordingly, it is confirmed that PEOwax is filled only in the lumen of the cell and does not enter the cell wall (the phenol resin tends to inhibit PEOwax from entering and filling the cell wall). did. That is, the mass increase rate is increased (the substance is introduced), but the swelling rate is not increased (rather, the swelling rate decreases with increasing the amount of added wax) into the cell wall. Means that there is no intrusion (decrease). If the addition of the wax increases the viscosity of the aqueous phenol resin solution, or if the phenols aggregate together to increase the apparent molecular size, penetration into the cell wall will be inhibited.

FIG. 2-2 shows a cross-sectional enlarged photograph of the prepared impregnated wood.
Although the PF resin is contained in the same amount in all the prepared woods, the complete filling of the cell lumen is hardly confirmed, and it appears that it is deposited on the surface of the cell wall lumen as indicated by the arrow in the figure.
On the other hand, it was confirmed that the PEOwax was filled in the entire lumen as in the cell lumen surrounded by the broken line in FIG. Moreover, the abundance ratio clearly increased as the PEOwax concentration increased.
From this, it was suggested that PF resin is mainly present in the cell wall and on the cell wall surface, and PEOwax is present in the woody material mainly in a form of filling the lumen.

FIG. 3 and Table 1 show the outline and results of thermal analysis of the prepared wood-based material.
DSC and DMA in FIG. 3 show the results of a PEOwax simple substance having a melting point near 125 ° C. and a wood-based material impregnated with PF resin and PEOwax.
At the 1st temperature increase of the DSC of the phenol resin-impregnated wood, the glass transition temperature Tgh and the curing peak temperature Tp (▼) of the PF resin are detected. At a 2nd temperature increase, the heat of fusion Qpeo that can grasp the content of PEOwax was quantified in the vicinity of Tm. According to the DSC results, in addition to confirming the softening temperature Tge and the curing start temperature Tce even at the first temperature rise of DMA, the relative ratio of the storage elastic modulus E ′ at 30 ° C. before and after curing was quantified.
From the DSC results of the phenol resin-impregnated wood, the Wax melting heat Q that can be converted into the amount of added wax was detected at the 1st temperature increase, the glass transition temperature Tgh, the curing peak temperature Tp, and the 2nd temperature increase. From the first temperature increase, the DMA evaluates the curing degree ΔEc ′ from the comparison of the curing start temperature Tce, the first temperature increase, and the 2nd temperature increase. Regarding the heat softening and heat curing behavior of impregnated wood, there is no significant change in their temperature range due to an increase in the addition rate of wax, so the interaction between phenol resin and wax is small, and may adversely affect fluid molding Was confirmed to be low.
Thus, by setting the melting point Tm of PEOwax to a lower temperature side than the curing temperature of the PF resin (Tm <Tp (142 ± 3 ° C.), Tce (135 ± 2 ° C.)) Lubricant can be leached to improve moldability.

2.2 Formability evaluation by side extrusion experiment Fig. 4-1 and Fig. 4-2 show the punch load F-punch in the side extrusion experiment of wood impregnated with 30% PF resin and PEOwax aqueous solution. A stroke S diagram is shown.
In Fig. 4-1, under the condition (0%) without the addition of PEOwax indicated by the bold line, a load peak (▽) appears when F is about 30kN (S is about 7mm), and the material to the side at this point The flow started. After reaching the peak, the load once decreased, but then began to increase and continued to increase. This was resistance due to sliding of the extruded material with the inner wall of the mold gap, and occurred because the contact surface increased as the extrusion length increased.

As for the amount of PEOwax added, the load peak value decreased at 0.9 or more, particularly 1.5%, and the load value at Se further decreased. This has shown that an easy moldability effect is acquired by addition of PEOwax, and extrusion length le increased as the photograph in FIGS. 4-1 and FIGS. 4-2.
As described above, it was found that the extrusion start load is remarkably reduced particularly when the addition amount of PEOwax is 1.5% or more. However, as shown in FIG. As a result, bleeding at the time of extrusion occurred, and an increase in the punch stroke S was recognized as an effect of reducing the load. The extrusion length le also increased due to these effects.

When these results are summarized in FIG. 5, when the addition amount of PEOwax is 0.5% or more, the effect of reducing the punch surface pressure P is recognized. At 1.5%, the punch surface pressure P is 0% of the addition amount of PEOwax. From about 40 MPa at this time to about 25 MPa, at 9.0%, it decreased to about 10 MPa. At the same time, as the extrusion stroke amount (Sf-Se) increased, the extrusion length le increased, and all the phenol resin-impregnated wood charged in the mold could be extruded.
Here, “Se” is a stroke after the start of extrusion (corresponding to a punch stroke region after exceeding the load peak), and “Sf” is a final stroke in the extrusion experiment (a stroke at a load of 50 kN (final)). ).
Thus, it was confirmed that PEOwax can impart easy moldability because it exerts a lubricating effect at a temperature lower than the resin curing temperature and does not inhibit curing in the fluid molding of thermosetting resin-impregnated wood.

3. Other Experimental Results Using Oxidized Polyethylene Wax FIG. 6 shows experimental results obtained by applying PEOwax (indicated as “PEw” in FIG. 6) to a mold and molding.
By applying PEOwax to a mold and performing molding, it is effective in improving moldability (effective compared to general-purpose laminate release additive (alkyl phosphate ester compound (AE)), A synergistic effect with the addition of PEOwax is obtained.)

FIG. 7 and FIG. 8 show the experimental results of molding using beech and bamboo as the wood-based material (raw material).
Although there is a difference in the degree of influence depending on the tree species of the woody material, it was confirmed that the moldability improved as the addition amount increased. Beech has a higher density (less voids) than cedar and a lower resin impregnation rate, so the extrusion length is shorter than cedar. Furthermore, bamboo has higher density, higher fiber rate, and less phenol resin impregnation, so extrusion hardly proceeds at 50 kN, but PEOwax (indicated as “PEW” in FIGS. 7 and 8). )) Was added.

FIG. 9 shows the experimental results of molding using a phenol resin and a melamine resin prepared at a concentration of 30% as thermosetting resins.
Compared with phenol resin, the effect of adding PEOwax (indicated as “PEW” in FIG. 9) when impregnated with melamine resin is small (melamine resin + PEOwax 1.5% is almost equivalent to phenol resin + PEOwax 0.01%) Shows the effect.)

4). Experimental Results Using Melamine Resin as Thermosetting Resin Therefore, melamine resin (hereinafter sometimes referred to as “MF”) is used as the thermosetting resin, and the amount of PEOwax added is increased. 10 to 13 show the results of experiments conducted using acid-modified polypropylene wax (hereinafter sometimes referred to as “PPwax” or “PPW”) as the lubricant composition.
Here, the acid-modified polypropylene wax used is as follows.
<Acid-modified polypropylene wax>
Melting point: 167 ° C
Acid value: 41 mg KOH / g
Number average molecular weight: 36000
Moreover, a cedar veneer having a thickness of about 3.0 mm (fiber L direction: 160 mm × tangential T direction: 100 mm, bulk density of 0.35 to 0.41 g / cm ³ ) was used as the wood-based material (raw material).
In addition, in the case of melamine resin and oxidized polyethylene wax (PEOwax), the addition amount of PEOwax to the woody material under the addition conditions of PEOwax 1.5%, 3.0%, 6.0% ), And 4.8 parts by weight, 7.6 parts by weight, and 12.0 parts by weight.
In addition, in the case of melamine resin and acid-modified polypropylene wax (PPwax), the addition amount of PPwax to the woody material under the addition conditions of PPwax 1.5%, 3.0%, 6.0% is the woody material ( 12.9 parts by weight, 14.8 parts by weight, and 23.0 parts by weight with respect to 100 parts by weight of the dry weight of the material.

As shown in FIG. 10-1, when a melamine resin prepared at a concentration of 30% is used as a thermosetting resin and the amount of PEOwax added is increased to 1.5, 3.0, and 6.0%, the weight increase rate It was confirmed that the tangential T-direction swelling rate decreased.
FIG. 10-1 shows a cross-sectional enlarged photograph of the prepared impregnated wood.

Further, as shown in FIG. 10-2, when a melamine resin prepared at a concentration of 30% is used as a thermosetting resin, and the addition amount of PPwax is increased to 1.5, 3.0, and 6.0%, the weight It was confirmed that the increase rate increased and the tangential T-direction swelling rate decreased.
Thereby, PEOwax and PPwax are filled only in the lumen of the cell, and no penetration into the cell wall occurs (the melamine resin tends to inhibit the penetration and filling of the PEOwax into the cell wall). It was confirmed. That is, the mass increase rate is increased (the substance is introduced), but the swelling rate is not increased (rather, the swelling rate decreases with increasing the amount of added wax) into the cell wall. Means that there is no intrusion (decrease). When the viscosity of the aqueous melamine resin solution increases or the apparent molecular size increases due to aggregation of the melamines due to the addition of the wax, penetration into the cell wall is inhibited.

11-1 and 11-2, and Table 2-1 and Table 2-2 show the outline and results of thermal analysis of wood-based materials prepared using PEOwax and PPwax as the lubricant composition, respectively.
The DSC and DMA shown in FIGS. 11A and 11B are the results of the PEOwax simple substance having a melting point near 125 ° C. and the wood-based material impregnated with MF resin and PEOwax, and the PPwax simple substance having a melting point near 156 ° C. The results of the wood-based material impregnated with MF resin and PPwax are shown.
From the DSC result of the melamine resin-impregnated wood, the softening / curing behavior could not be detected, and only the wax heat of fusion Q that could be converted into the amount of added wax was detected. From the DMA results, the degree of cure ΔEc ′ was evaluated from the comparison of the 1st temperature rise to the softening temperature Tge, the curing start temperature Tce1, the curing end temperature Tce2, the 1st temperature rise and the 2nd temperature rise.
The melamine resin has a slower curing reaction than the phenol resin, and the storage elastic modulus increases over a wide range. Regarding the thermal softening and thermal curing behavior of the impregnated wood, although the high temperature side shift of the curing temperature is slightly seen with respect to the increase of the wax addition rate, the degree of curing has definitely risen to 1 or more, which has an adverse effect on fluid molding. It was confirmed that the effect was low.

12-1 and 12-2 impregnated with melamine resin prepared at 30% concentration and aqueous solution of PEOwax or PPwax, conducted in the same manner as in “1.3 Lateral Extrusion Mold and Formability Evaluation” The punch load F-punch stroke S diagram in the side extrusion experiment of the made wood is shown.
Regarding the addition amount of PEOwax, as shown in FIG. 12A, the reduction of the extrusion load and the increase of the extrusion length due to the increase of the addition amount of PEOwax are less effective than those of the PF resin. This is because the softening and curing behavior of the MF resin-impregnated wood is significantly different from that of the PF resin, and it is considered that the melting point of PEOwax is too low compared to the MF curing temperature. In addition, use of PEOwax as a mold release agent is effective for improving moldability.
On the other hand, regarding the addition amount of PPwax, as shown in FIG. 12-2, a decrease in the extrusion load and an increase in the extrusion length due to an increase in the addition amount of PPwax were observed even when no release agent was used. It was. This is presumably because the balance between the melting point of PPwax and the curing temperature of the melamine resin-impregnated wood was in a good temperature range.
When these results are summarized in FIG. 13, PEOwax has little effect on improving molding (reduction of extrusion start surface pressure and increase of extrusion length) with respect to melamine resin-impregnated wood, but PPwax is impregnated with melamine resin. It turns out that it acts very effectively on the improvement of the molding of wood.

5. Experimental Results Using Phenol Resin and Acid-Modified Polyalkylene Wax Hereinafter, experimental results performed using phenol resin as the thermosetting resin and acid-modified polyalkylene wax as the lubricant composition are shown in FIGS. Shown in
Here, a cedar veneer having a thickness of about 3.0 mm (fiber L direction: 160 mm × tangential T direction: 100 mm, bulk density 0.35 to 0.41 g / cm ³ ) was used as the wood-based material (raw material). .
In addition, under the addition conditions of PEOwax 1.5%, 3.0%, and 6.0%, the amount of PEOwax added to the woody material is 4 parts by weight with respect to 100 parts by weight of the dry weight of the woody material (raw material). 0 parts by weight, 6.0 parts by weight, and 4.5 parts by weight (Here, the amount of addition does not increase under the 6.0% addition condition is due to variations in the density of the wood-based material (raw material). Possible cause.)

As shown in FIG. 14, when a phenol resin prepared at a concentration of 30% is used as the thermosetting resin and the addition amount of PPW is increased to 1.5, 3.0, and 6.0%, the weight increase rate increases. It was confirmed that the tangential T-direction swelling rate decreased (similar to PEOwax). Here, for comparison, PEOwax (indicated as “PEW” in FIG. 14) (added amount: 6.0%) is shown in parallel (the same applies hereinafter).
As a result, it is confirmed that PPW is filled only in the lumen of the cell and does not enter the cell wall (the PP resin tends to inhibit the penetration and filling of the PPW into the cell wall). did.
FIG. 15 shows a side extrusion test of wood impregnated with an aqueous solution of phenol resin and PPW prepared at a concentration of 30%, which was performed in the same manner as in “1.3 Side extrusion mold and moldability evaluation”. The punch load F-punch stroke S diagram is shown.
It can be seen that the reduction of the extrusion load and the increase of the extrusion length due to the internal addition of PPW are not as effective as PEOwax. However, there is some fluidity improvement effect compared with the case where it is not added. Note that with 6.0% PEW, the push-in amount increased, and as shown in FIG. 16, the extrusion length le increased as shown in the photograph in FIG. 15.
FIG. 17 and Table 3 show an outline and results of thermal analysis of the prepared wood-based material.
DSC and DMA in FIG. 17 show the results of PPwax alone having a melting point near 156 ° C. and a wood-based material impregnated with PF resin and PPwax.

As in the case of PEOwax shown in FIG. 3, for PPW, the amount of added wax can be converted at 1st temperature rise, glass transition temperature Tgh, curing peak temperature Tp, and 2nd temperature rise from the DSC result of phenol resin-impregnated wood. Wax heat of fusion Q was detected. From the first temperature increase, the DMA evaluates the curing degree ΔEc ′ from the comparison of the curing start temperature Tce, the first temperature increase, and the 2nd temperature increase. As the heat softening and heat curing behavior of the impregnated wood does not show any significant change in the temperature range due to the increase in the wax addition rate, the interaction between the phenolic resin and the wax is small, and may adversely affect fluid molding Was confirmed to be low.
Thus, it was confirmed that PPW can impart easy moldability because it achieves a lubrication effect and does not inhibit curing in fluid molding of wood impregnated with a phenol resin as a thermosetting resin.
Here, comparing the experimental results of oxidized polyethylene wax and acid-modified polypropylene wax, it was found that oxidized polyethylene wax was more effective in improving moldability.
One reason for this is considered to be due to the difference in melting point (PPW Tm = 156 ° C.> phenolic resin curing temperature> PEW Tm = 125 ° C.). The melting point of the lubricant composition is determined by the lubricant composition being lubricated. In order to function sufficiently as an agent, it may be preferable to use a substance having a melting point lower than the curing temperature of the thermosetting resin. However, the melting point of the lubricant composition is about the same as the curing temperature of the thermosetting resin (the curing temperature of the thermosetting resin + about 10 ° C.), and the molding is performed by raising the temperature to the melting point of the lubricant composition at the time of molding. In this case, it was confirmed that the lubricant composition sufficiently functions as a lubricant.

  As described above, the woody fluid molding precursor of the present invention and the molding method thereof have been described based on the embodiments thereof, but the present invention is not limited to the examples described in the above embodiments, and the gist thereof is The configuration can be changed as appropriate without departing from the scope.

  The wood fluid molding precursor and the molding method thereof according to the present invention improve the moldability by reducing the deformation resistance of the wood material in the wood fluid molding using the thermosetting resin by modifying the wood material itself. Because it can be used, it is suitable for a wide range of applications such as interior and exterior building materials, vehicle (aircraft, car, train) interior, vehicle parts, toys, musical instruments, home appliance exteriors, home appliance parts, furniture, tableware, etc. Can do.

Claims (6)

  In a wood fluid molding precursor in which a thermosetting resin is impregnated with a wood material, together with the thermosetting resin, at least one of an oxidized polyalkylene wax and an acid-modified polyalkylene wax as a lubricant composition is used. A wood fluid molding precursor characterized by being impregnated with a material.   2. The wood fluid molding precursor according to claim 1, wherein the lubricant composition is mainly filled in a lumen of a wood material material cell.   3. The woody fluid molding precursor according to claim 1 or 2, wherein the oxidized polyalkylene wax is an oxidized polyethylene wax.   The wood fluid molding precursor according to claim 1 or 2, wherein the acid-modified polyalkylene wax is an acid-modified polypropylene wax.   The wood fluid molding according to any one of claims 1 to 4, wherein the lubricant composition is made of a substance having a melting point equal to or lower than a curing temperature of the thermosetting resin. Precursor.   A method for forming a wood fluid molding precursor obtained by impregnating a wood-based material according to any one of claims 1 to 5 with a thermosetting resin, wherein the wood fluid molding precursor is formed using a molding die. A molding method for a wood fluid molding precursor, wherein the molding is performed at a temperature higher than a curing temperature of a thermosetting resin.

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