JPH0447902A - Manufacture of laminated material - Google Patents

Abstract

PURPOSE:To enhance the utilization of culm and obtain the laminated material concerned having arbitrary specific gravity, thickness, dimensions and extremely high mechanical strength by a method wherein culm layers, each of which is prepared by densely arranging culms in linear portion parallel to one another, are laminated to one another and, after that, formed under pressure through adhesive, which is prepared from the waste culms, leaves sheaths of true grasses. CONSTITUTION:Adhesive is prepared by dissolving the leaves or sheaths cut off the culms of true grasses, odds, which are left behind the cutting of the culms for linear portion, waste culms or cores developed at the removal of core in phenols and adding aldehyde compound and acid catalyst or alkali catalyst to the resultant solution. A plurality of linear culms are flattened without being cut off in the direction of fiber so as to form a plurality of flattened culms 2. By densely arranging a plurality of the flattened culms 2 parallel to one another, a flattened culm layer 3 is formed. After being applied with the adhesive, the flattened culm layers 3 are laminated to one another and then formed under pressure. When the adhesive, which is made from raw material consisting of the same culm and the like as the culm to be bonded, is used, the affinity at bonding becomes higher, resulting in obtaining laminated material 10 having much higher strength and allowing to produce laminated material 10 having arbitrary specific gravity, thickness and dimensions out of culms.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a laminated material whose main raw material is stems of plants belonging to the Poaceae family, such as corn, corn, and sugar cane.

More specifically, the present invention relates to a method for manufacturing laminated materials used for construction materials, furniture materials, heat insulating materials, sound absorbing materials, display materials, and various construction materials.

[Conventional technology] Conventionally, wood-based construction materials, furniture materials, display materials,
In addition to plywood and laminated wood, particle board and fiberboard are used as sound-absorbing materials and various construction materials, and polystyrene, polyurethane, polyethylene, phenolic resin, urea resin, etc. are used as display materials, sound-absorbing materials, and heat-insulating materials. A synthetic resin solid body or foam is used.

The materials used for these purposes all depend on wood resources and petroleum resources. Plywood and sawn wood are wood itself, and particle board is a board material obtained by mixing thin pieces of wood with a synthetic resin adhesive and curing it under heat and pressure. Fiberboard is a board material made of wood or other vegetable fibers as is, or by mixing a synthetic resin adhesive and curing the mixture under heat and pressure.

Particle boards and fiberboards have already been made using sugar cane, etc., cut into pieces or fibers, but they do not have a satisfactory level of mechanical strength or dimensional stability. Plywood, particle board, fiberboard, etc. have less anisotropy than sawn wood from natural wood, and have fewer defects such as knots and decayed parts.
It has the characteristic of not easily warping or deforming, and the desired specific gravity, thickness, and dimensions can be selected depending on the application.

However, plywood, laminated wood, which is used in large quantities for construction materials, etc.
Wooden materials such as particleboard and fiberboard are
Since both of them are made from natural wood as their main raw material, as wood resources have become increasingly depleted in recent years, there has been a limit to their supply.In the future, it will be impossible to fully meet demand, and prices will rise significantly. Fear is arising.

In addition, synthetic resin foams such as polystyrene, polyethylene, polyurethane, and phenolic resin, which are dependent on petroleum resources, are lightweight, easy to process, and have excellent heat insulation properties, so they are used in a wide range of applications as display materials and heat insulation materials. ing. However, due to the limited availability of petroleum resources, the prices of these petroleum products have soared significantly, and securing their quantity is becoming a problem in the future.

In order to respond to this situation, the present applicant has developed the use of grass stems such as grass, corn, and sugar cane, which are abundant worldwide and are reproduced every year and are difficult to dispose of. A patent application was filed for a laminated material using straight sections and a method for manufacturing the same (Japanese Patent Application Laid-Open No. 107505/1983.
-280538).

The method described in Japanese Patent Application Laid-open No. 63-107505 involves cutting the stems of plants of the Poaceae family, such as corn, corn, and sugar cane, in the direction of the fibers, removing the core if necessary, and cutting the stems in the cut state. In this method, a plurality of rolled stalks are arranged in parallel to each other to form a sheet-like product, a known adhesive is applied to the plurality of sheet-like products, and then these are laminated and pressure-molded.

In addition, the method described in Japanese Patent Application Laid-Open No. 1-280538 involves forming a flattened stem by leaving the stem of a tall lily without incising it or by compressing it to form a flattened stem, and arranging a plurality of flattened stems to form a flattened stem layer. , a method in which a known adhesive is applied to a plurality of flat stem layers, and then these are laminated and pressure molded.

The laminated materials made by these methods can be made into plates of arbitrary specific gravity, thickness, and dimensions, and have extremely excellent mechanical strength.

[Problems to be Solved by the Invention] However, in the former method, if the pressure is increased during rolling or pressure forming, or if the thickness of each sheet is reduced by core removal, the number of laminated layers may be reduced. Due to the increase in the amount of raw material stems used, a large amount of adhesive is required.

In addition, although the latter method reduces the number of laminated layers and increases the proportion of raw material stems used compared to the case of core removal, the existence of a core with a low specific gravity increases the dimensional stability of the flat stem layer, which absorbs water easily. Therefore, a large amount of adhesive must be used. For this reason, all of the above conventional methods have the problem of requiring a large amount of relatively expensive adhesive.

Furthermore, the proportion of straight parts with a certain thickness in the stems of plants belonging to the Poaceae family, such as tall grass, corn, and sugar cane, is low. Many parts, such as leaves, hakama parts, and core parts when cored, had to be discarded, and there was a problem that the yield ratio of the usable part of the plant stem, that is, the yield, was extremely low.

The purpose of the present invention is to have a high utilization ratio of plant stems as raw materials,
The object of the present invention is to provide a method for manufacturing a laminate material that can be made into any specific gravity, thickness, and size and has extremely high mechanical strength.

[Means for Solving the Problems] In order to achieve the above object, the method for manufacturing a laminated material of the present invention uses felled stems of grasses, such as corn, corn, and sugar cane, as a raw material for the laminated material. Parts unsuitable for raw materials generated during processing, such as curved stems, leaves, and hakama, are effectively used as adhesives for laminated materials.

The first manufacturing method involves cutting off leaves or hakama parts from a plurality of grass family plant stems and cutting them off leaving straight parts of the stems, and fragments, stem waste, leaves or hakama produced by the cutting or cutting. After dissolving the parts in phenols, an aldehyde compound and an acid or alkali catalyst are added to this solution to prepare an adhesive, and the plant stems of the straight parts are arranged parallel to each other and closely in an intact state. In this method, a plant stem layer is formed, the adhesive is applied to the plant stem layer, and the plurality of plant stem layers are laminated and pressure-molded.

Further, in the second manufacturing method, a plurality of straight plant stems are flattened without being cut in the fiber direction to form a plurality of flat stems, and the plurality of flat stems are arranged in parallel and closely to each other to form a flat stem. In this method, a stem layer is formed, the adhesive is applied to the flat stem layer, and these layers are laminated and pressure-molded. 1st
The figure shows a laminate 10 made by this method. In the figure, a is the stem skin, b is the core, C is the node, 2 is the flat stem, and 3 is the flat stem layer.

In addition, the third manufacturing method involves cutting or dividing the straight portion of the plant stem in the fiber direction, flattening it to form a flat divided stem, and forming a flat divided backing layer in which a plurality of flat divided stems are arranged. This is a method of manufacturing a laminated material in the same manner as the first method by applying the adhesive to the flat stem layer obtained in the first method. FIG. 2 shows a laminate 20 made by this method. In the figure, 4 is a flat split backing layer.

Furthermore, in a fourth manufacturing method, the straight portion of the plant stem is cut or divided into two, then cored and rolled, and a plurality of rolled stems are arranged to form a sheet-like product, and the same as in the first method. This is a method of manufacturing laminated materials. Figure 3 shows the manufacturing process. In the figure, 1 is a plant stem, 5 is a knife, 6 is a rolling machine, 7 is a rolled stem, 8 is a sheet-like product, and 30 is a laminate made by this method.

In either method, 1. High corn,
The stems of plants belonging to the Poaceae family, such as sugar cane, are cut to a certain length in accordance with the dimensions of the desired laminated material. To prevent the plurality of arranged plant stems, flat stems, flat divided stems, or rolled stems from dispersing, all the arranged stems are temporarily fixed with adhesive tape, sutured with thread, or a thread-like adhesive is applied. be done.

As a result, a plant stem layer, flat sandals, flat split stem waste, or sheet-like material is formed. An adhesive tape 9 is shown in FIG. Drying is done after cutting the plant stems, or by drying the plant stem layer, flat sandals, etc.
This is done after the stem waste is flattened and formed into a sheet-like product.

It is preferable to intersect the plant stem layer, flat sandals, flat split stem waste or sheet-like material perpendicularly in each layer to increase strength.

After lamination, temporary compression is applied as necessary, and the temperature is 100 to 250℃.
At a temperature of 0.1 to 5 minutes per 11 laminate thickness, 5 to 30
The laminated material of the present invention is obtained by molding at a pressure of 100 kg/cm''.The surface of this laminated material is processed using a scraper, planer, sander, etc. so that it has a predetermined thickness.

The adhesive of the present invention can be applied to leaves or hakama parts cut from the stems of grasses such as grass, corn, and sugar cane, fragments cut off leaving straight parts of the stems, stem scraps, or removed cores. It is prepared by dissolving the core of time in phenols and then adding an aldehyde compound and an acid or alkali catalyst to this solution.

As raw materials for the adhesive, leaves or hakama parts excised from the grass stems, fragments cut off leaving straight parts of the stems, stem waste, or cores after core removal (hereinafter referred to as plant stems) are used as raw materials for the adhesive. etc.)
However, lignocellulosic materials such as wood sawdust, sander dust, waste wood, rice straw, rice husks, waste paper, etc. may be added to the plant stems.

Further, in the production method of the present invention, after dissolving the above-mentioned plant stems in phenol, an aldehyde compound and an acid catalyst or an alkali catalyst are added to the solution, and an isocyanate-based resin adhesive, a thermosetting One type or a mixture of two or more types of adhesives selected from polyester resin adhesives, cold-curable resin adhesives, and aqueous emulsion resin adhesives may be used.

If the raw material for the adhesive is a plant stem of the same type as the plant stem to be bonded, the affinity during bonding will be higher, and a laminated material with significantly higher strength will be obtained.

Furthermore, the adhesive obtained by dissolving the plant stems, etc., into a resin has a wide molecular weight distribution, and is a multimolecular resin in which high molecular weight parts and low molecular weight parts coexist in an appropriate ratio. . Therefore, when adhesives made of such polymolecular resins are used to adhere grass plant stems with porous cores such as grass, corn, sugar cane, etc., the high molecular weight part of the adhesive Excessive penetration of the adhesive into the core of the stem is suppressed, and its low molecular weight portion increases the affinity (wettability) between the adhesive and the plant stem, and when a commercially available adhesive is applied alone. Much better adhesion performance can be obtained.

Examples of the phenols that dissolve the plant stems include phenol, cresol, resorcinol, chlorinated phenol, xylenol, bisphenol A, or F1 phloroglucinol.

Methods for dissolving the plant stems, etc. in phenols include a high-pressure dissolution method, in which the plant stems, etc. are mixed with phenols, and dissolved at a temperature of 150 to 350°C and a pressure of 15 to 100 atm; Mix plant stems, etc. with the phenols, and add 10
There is a normal pressure dissolution method in which melting is performed at a temperature of 0 to 200°C and a pressure of 1 to 1.5 atm. Acids used in the acid catalyst of the normal pressure dissolution method include inorganic acids such as sulfuric acid, hydrochloric acid, and phosphoric acid, and organic acids such as benzenesulfonic acid, paratoluenesulfonic acid, formic acid, acetic acid, and maleic anhydride. .

One type or two or more types of these acids may be used.

Plant stems, etc. contain 10 to 1% of phenols by weight.
0000% by weight and dissolved. When dissolving a large amount of plant stems, etc., the plant stems, etc. are further added to the phenol solution. Acids as catalysts are phenols 1
It is added in an amount of 0.5 to 100% by weight relative to 00% by weight.

When preparing a solution of plant stems, etc., add an organic solvent such as acetone, dioxane, toluene, etc. to 100% by weight of phenol.
Addition of 0 to 1000% by weight is preferable because dissolution of plant stems and the like is promoted. .

Next, aldehyde compounds such as formaldehyde, rose formaldehyde, etc. are added to the phenol solution of plant stems, etc.
Alternatively, the adhesive of the present invention can be obtained by adding a compound such as hexamine that generates an aldehyde upon heating, adding an acid catalyst or an alkali catalyst, and reacting at 50 to 150° C. under atmospheric pressure.

Examples of the acid catalyst include hydrochloric acid, sulfuric acid, formic acid, acetic acid, and phenolsulfonic acid, and examples of the alkali catalyst include caustic soda, potassium hydroxide, ammonia, organic amines, calcium hydroxide, magnesium hydroxide, and the like.

At this time, the phenol solution should be 100% by weight, depending on the quality and properties of the adhesive required and the amount of dissolved plant stems, etc.
The aldehyde compound is added in an amount of 5 to 2000% by weight, and the catalyst is added in an amount of 1 to 200% by weight.

In order to adjust the viscosity and adhesion of the adhesive and reduce the shrinkage rate during curing, the adhesive thus obtained is further mixed with wheat flour, rice flour, barley flour, defatted soybean flour, corn starch, potato starch, blood meal, etc. Bulking agents or fillers such as wood flour, walnut flour, calcium carbonate, sodium carbonate, bentonite, kaolin clay, talc, zeolite, etc. may be added.

The adhesive may be applied by any method such as spray coating, curtain flow coating, roller coating, or dipping.

[Effects of the Invention] As described above, according to the present invention, a laminated material having any specific gravity, thickness, and size can be made from plant stems.

In addition, since the raw material for the adhesive is the same grass stems as the plant stems to be bonded in the lignocellulose material, it has a high affinity during bonding, resulting in a laminated material that is highly strong and firmly bonded. .

In addition, plant stems, which have hitherto had a low yield, can be used more effectively, and there is no need to use conventional expensive laminated materials.

[Example] Next, an example of the present invention will be described in detail together with a comparative example.

<Example 1> After cutting off the leaves, hakama and curved stems from 17 Takariyan stems, each 180cm straight Takariyan stem was cut in the fiber direction, and the core was removed with a sanding roller. Removed. The incised state was rolled by a rolling machine to obtain a rolled stem having one side made of stem skin. 3 of each of these rolled stems
After cutting the stalks into 0cm lengths and arranging 7 rolled stalks in parallel and closely, both ends were temporarily fixed with adhesive tape to obtain a sheet with a width of 30cm and a length of 30cm. .

On the other hand, fragments, stem waste, leaves, hakama, core parts, etc. generated from the Takariyan stem are cut into small pieces, and 700 pieces of the Takariyan stem are cut into small pieces.
g and 300 g of phenol were packed into a 1-liter autoclave, and the temperature was raised to 250° C. while stirring slowly.

The pressure inside the autoclave was increased to 45 atmospheres, and this state was maintained for about 3 hours, and the pieces of the Chinese radish stem were dissolved in phenol.

Next, put 800 g of this solution and 100 g of 37% formalin into three 1-volume flasks, and while stirring,
16 g of a caustic soda aqueous solution was added and reacted for 20 minutes at a temperature of 85 to 90°C, followed by rapid cooling to prepare an adhesive. Calcium carbonate 4 as a filler to 800g of this adhesive
0 g and 40 g of sodium carbonate were added to obtain an adhesive paste.

Fourteen sheets were prepared, and one side of each sheet was spray coated with the obtained adhesive. First, three sheets are stacked with the same fiber direction, then seven sheets are stacked so that the fiber directions of these three sheets are perpendicular to each other, and then Four sheets were stacked one on top of the other in the same fiber direction as the first stack of three sheets. 10 kg/cm by hot pressing 14 sheets stacked at 150℃
The molding was carried out under hot pressure for 6 minutes.

Water evaporates from the sheet-like material, and the specific gravity is 0.68 and the thickness is 9.
A square laminate of size 1 was obtained. After curing at room temperature for about one week, the bending strength and peel strength of the laminate were measured according to JIS A 5908.

As a result, the average bending strength is 720 kgf/cm'
The peel strength was 330 kgf/cm' after repeated boiling treatments, and the average peel strength was 6.6 kgf/am' under normal conditions.

<Comparative Example 1> Instead of the adhesive for the sheet of Example 1, a commercially available phenolic resin adhesive ([PF
-109) An adhesive was prepared by adding 80 g of a special filler (■ EP-905 manufactured by Honen Corporation) to 800 g, and a laminate was produced in the same manner as in Example 1 except that this adhesive was used. .

The bending strength and peel strength of this laminate were measured in the same manner as in Example 1, and the average bending strength was 360 kgf under normal conditions.
/cm", and 170 kgf/c after repeated boiling treatment, and the average peel strength was 4.3 kgf/c+a" under normal conditions.

From this, it was found that the strength of the laminate of the present invention was approximately twice as high as that of the conventional one.

<Example 2> After cutting off the leaves, hakama and curved stem portions from 17 corn stalks, a 30 cm straight portion of the corn stalks was cut in the fiber direction and rolled to form rolled stalks. Arrange these four rolled stems as a set, 1 a+mX 300m+
A sheet-like product with a x 300 mm was obtained.

The adhesive glue of Example 1 was roller coated on both sides of each of these 14 sheet-like materials. The amount of adhesive used is 50
It was g. First, four sheets are stacked with the same fiber direction, then six sheets are stacked so that the fiber directions of these four sheets are perpendicular to each other, and then the first The four sheets were stacked one on top of the other in the same direction as the fibers of the four-sheet stack. 14 sheets stacked in a hot press maintained at 150℃
Hot pressure molding was carried out for 7 minutes by applying a pressure of 5 kg/am''.

Water evaporates from the sheet-like material, and the specific gravity is 0.61 and the thickness is 1.
A square laminate of 2+o■ was obtained. After curing in the same manner as in Example 1, the normal bending strength of the laminate was measured according to JIS A 5908, and the average was 422 kgf.
/c++1.

<Example 3> 500 g of sugar cane squeezed lees strips and 500 g of phenol
was placed in a 1-liter dissolving can, 12 g of concentrated sulfuric acid was added, and the temperature was raised to 150°C. This condition was maintained for about 2 hours, and the sugar cane pieces were dissolved in the phenol.

Next, 200 g of this solution and 540 g of 37% formalin were placed in a 1 cubic volume reactor, 100 g of 40% caustic soda aqueous solution was added while stirring, and the mixture was heated at a temperature of 85 to 90°C for 50 minutes.
The adhesive was prepared by reacting for 0 minutes and then rapidly cooling. An adhesive paste was obtained by adding 80 g of wood flour as an extender and 80 g of sodium carbonate as a filler to 800 g of this adhesive.

Next, the soybean stalk was divided into two parts in the fiber direction using a knife, and then rolled using a rolling machine. Arrange these rolled stalks to a length of 1 m.
A sheet-like product measuring 300 mm x 300 mm was obtained.

Eight sheets of this type were prepared, and the adhesive paste was applied by roller coating to the core side opposite to the stem skin side of each sheet. The amount of adhesive glue used was 50 g. first 2
Two sheets are stacked with the same fiber direction, then four sheets are stacked so that the fiber directions of these two sheets are perpendicular to each other, and then the first two
Two sheets were stacked one on top of the other in the same direction as the fibers of the stacked sheets. 150 sheets of 8-ply material
Hot press molding was carried out for 5 minutes by applying a pressure of 15 kg/cm" using a hot press maintained at .degree.

The water evaporates from the sheet material, and the specific gravity is 53 and the thickness is 6.
A square laminate of mm square was obtained. After curing in the same manner as in Example 1, the normal bending strength of the laminate was measured according to JIS A 5908, and the average was 287 kgf/c.
It was "m".

From the results of Examples 2 and 3, it was found that both of these laminates had industrially excellent strength.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a laminate manufactured by the second method of the present invention. FIG. 2 is a perspective view of a laminate manufactured by the third method of the present invention. FIG. 3 is a manufacturing process diagram of the fourth method of the present invention. 10.20,30: Laminated material,

Claims (1)

[Scope of Claims] 1) Cutting leaves or hakama parts from the stems of a plurality of grass family plants and cutting them off leaving straight parts of the stems, and fragments, stem waste, and leaves produced by the cutting or cutting. Alternatively, after dissolving the hakama parts in phenols, an aldehyde compound and an acid or alkali catalyst are added to this solution to prepare an adhesive, and multiple straight parts of the plant stems are glued together in parallel and closely together as they are. A method for manufacturing a laminated material, comprising arranging the plant stem layers to form a plant stem layer, applying the adhesive to the plant stem layer, and laminating and press-molding the plurality of plant stem layers. 2) Cut the leaves or hakama parts from the stems of multiple grass plants, cut them off leaving the straight parts of the stems, and use the fragments, stem waste, leaves or hakama parts resulting from the cutting or cutting as phenols. Then, an aldehyde compound and an acid or alkali catalyst are added to this solution to prepare an adhesive, and a plurality of straight plant stems are flattened without cutting in the fiber direction to form a plurality of flat stems. , arranging the plurality of flat stems in parallel and close to each other to form a flat stem layer, applying the adhesive to the flat stem layer, and laminating the plurality of flat stem layers and press-molding them. Method of manufacturing wood. 3) Cutting off leaves or hakama parts from the stems of multiple Poaceae plants and cutting them off leaving straight parts of the stems, fragments of the plant stems, stem waste, leaves or hakama parts produced by the above cutting or cutting. is dissolved in phenols, and then an aldehyde compound and an acid or alkali catalyst are added to this solution to prepare an adhesive. A plurality of straight portions of the plant stem are each incised or divided into two in the fiber direction, and the incisions are made. Alternatively, a plurality of divided stems each having a core are flattened to form a plurality of flat divided stems, and the plurality of flat divided stems are arranged in parallel and closely to each other to form a flat divided stem layer. . A method for producing a laminated material, comprising applying the adhesive to the flat divided stem layer and the flat layer according to claim 1, and alternately stacking and pressure forming the plurality of flat divided stem layers and the flat layer. 4) After cutting off the leaves or hakama parts from a plurality of grass plant stems and cutting them off leaving a straight part of the stem, each of the plant stems in the plurality of straight parts is cut in the fiber direction or divided into two parts. , removing the core from the plant stem in the plurality of incisions or bisected linear parts, and treating the plant stem fragments, stem scraps, leaves, or hakama parts produced by the cutting or cutting, and the removed core with a phenol. After dissolving the aldehyde compound and an acid or alkali catalyst in this solution, an adhesive is prepared, and the cored plant stems of the plurality of linear parts are each incised or divided into two parts and rolled to form one side. forming a plurality of rolled stems made of stem skin, arranging the plurality of rolled stems in parallel and close to each other to form a sheet-like object, applying the adhesive to the sheet-like object, and applying the adhesive to the sheet-like object; A method for producing laminated materials by laminating and press-forming sheet-like materials. 5) fragments of plant stems resulting from the above excision or cutting;
After dissolving the stem scraps, leaves, hakama parts, or the removed core in phenol, add an aldehyde compound and an acid or alkali catalyst to this solution to prepare an adhesive, add an isocyanate resin adhesive, and a thermosetting adhesive. 5. The production of the laminated material according to claim 1, wherein the laminate is coated by mixing one or more adhesives selected from a thermosetting resin adhesive, a room temperature curing resin adhesive, or an aqueous emulsion resin adhesive. Method.