JPS6289744A - Production of foamed phenolic resin composite material - Google Patents

Abstract

PURPOSE:To obtain the titled composite material having improved flexural modulus and surface hardness, by introducing a specific granular foamable phenolic resin composition in a molding cavity to form a granular layer, applying an aggregate particle layer on the granular layer, applying the above granular layer thereon and repeating the procedure 1 - several times. CONSTITUTION:A granular foamable phenolic resin composition is produced by compounding 100pts.(wt.) of a phenolic resin precondensate with 1-50pts. of a decomposition-type foaming agent (e.g. N,N-dinitroso pentamethylenetetramine) and, if necessary, a curing agent (e.g. hexamethylenetetramine). The composition is introduced into a molding cavity to form a granular layer at the bottom of the cavity. Aggregate particles (e.g. pearlite, wood flour, etc.) are placed on the layer to form an aggregate layer preventing the mixing of each layer and the above composition is scattered on the aggregate layer to form a granular layer. The above operation is repeated 1 - several times to form a composite layer, which is foamed and hardened by heating in the molding cavity in closed state.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a method for producing a foamed phenolic resin composite. More specifically, the present invention relates to a 1J manufacturing method for a foamed phenolic resin composite with improved flexural modulus and surface hardness.

(B) Conventional technology Conventionally, foamed plastic (or unfoamed) powdered foam is a mixture of lightweight flake particles such as powder or inorganic particles, uncured novolak type phenol-formaldehyde resin, curing agent, and blowing agent. A known method is to fill a predetermined mold with the mixture and heat it to foam and harden it to form a phenol-roof-ohm composite.

(c) Problems to be Solved by the Invention However, in such a manufacturing method, aggregate particles and foamable phenolic resin! No matter how uniformly the composition No. 1 is mixed before foaming and hardening, it is difficult to obtain a phenol foam composite in which aggregate particles are uniformly dispersed.

This means that the aggregate particle-composition balance before foaming and hardening is
This may be due to collapse due to foaming or expansion of the composition during foam curing, or due to natural non-uniformity between the aggregate particles and the composition due to differences in specific gravity or shape during or after filling into the mold. Conceivable. This tendency is especially true for particles with a particle size of 2m.
When aggregate particles with a diameter of m or more were used, it was large, and the larger the particle size, the more significant the J: was.

Regarding this point, the present inventors first formed a layer of a foamable phenolic resin composition only on the bottom surface of the mold, and then stacked aggregate particles on the composition layer without mixing the composition with the foamable phenolic resin composition. We proposed a method for manufacturing phenolic foam composites in which aggregate particles are uniformly dispersed by heating (
V1 Publication No. 60-101031). however,
When a phenol foam composite having a thickness of 20 flllT1 or more is produced by this method, it is a problem that the upper surface is completely filled with phenol foam. Therefore, such a composite has an extremely weak flexural modulus and is unsatisfactory as a product. In addition, when a phenol foam composite with a thickness of 20 mm or less is manufactured using this method,
In order to completely fill the upper surface with phenol foam, a foamable phenol resin composition is required, which increases the cost.

In addition, after coating aggregate particles with a foamable phenolic resin composition and filling the foamable resin-coated particles into a mold,
A method has been proposed in which a phenol foam composite is produced by heating this mold in a heated state. In the phenol foam composite produced by this method, pearlite grains are uniformly dispersed throughout, and the density of the phenol foam portion is uniform. However, such a composite has an insufficient bending modulus because the density inside and outside of the phenol foam portion is the same.

Furthermore, if the amount of foamable phenolic resin composition was small, only a phenol foam composite with a soft surface could be obtained. Furthermore, since a step of coating the aggregate particles with the foamable phenolic resin composition is required, there is a problem in that the manufacturing cost is high.

This invention has been made in view of the above circumstances, and specifically aims to provide a method for manufacturing a foamed phenolic resin composite having a high flexural modulus and high surface hardness easily and at low cost. It is.

(d) Means and action for solving the problems Thus, according to the present invention, a granular foamable phenolic resin composition comprising a phenolic resin initial condensate, a decomposable foaming agent, and a curing agent added as necessary. is introduced into a mold to form a granular layer of the composition at the bottom thereof, and then (al) aggregate particles are piled onto the granular layer without being substantially mixed with the granular layer to form aggregate repeating the step of forming a layer of aggregate particles and +b) again spraying the foamable phenol resin composition on the aggregate particle layer to form a granular layer of the composition, once to multiple times; A composite layer was formed with a granular layer of an expandable phenolic resin composition on the bottom and an upper part, with an aggregate particle layer optionally interposed between the layers, and then the mold was closed. A method for producing a foamed phenolic resin composite is provided, which comprises foaming and curing a foamable phenolic resin composition by heating the foamed phenolic resin composition.

Examples of the phenol resin initial condensate used in this invention include novolac type and resol type phenol resin initial condensates. Here, the novolak-type phenolic resin initial condensate is a so-called novolak-type phenol resin known in the art, which is obtained by reacting phenols and aldehydes in the presence of an acidic catalyst. This means that the polymerization can proceed further.

This resin is generally solid at room temperature. On the other hand, the resol type phenolic resin initial condensate is a so-called resol type phenol resin known in the art, which is obtained by reacting excess aldehydes such as phenols in the presence of a basic catalyst, and is acid-curable. It means a substance whose polymerization can proceed with an accelerator and heating.

Such a resol type phenolic resin itself is a liquid containing about 20% of reaction water, but it is further dehydrated (evaporated of water) to form a solid (containing 1% of water), Next, this solid material is pulverized or extruded to obtain the granular resol type phenol resin used in the present invention. Of course, a commercially available powdered resol type phenol resin may also be used. Incidentally, in this invention, granules include not only powder but also relatively small-diameter pellets, tablets, flakes, and primary foam particles.

In addition to phenol, the above phenols include 3,5-xylenol, m-cresol, 2,5-xylenol,
Includes 3.4-xylenol, 2.4-xylenol, 0-cresol, p-cresol, and the like. Also, aldehydes include formaldehyde, paraformaldehyde,
Includes hexamethylenetetramine, furfural, acetaldehyde, acetals, etc. A preferred precondensate for use in this invention is a condensate of phenol and formaldehyde.

The decomposable blowing agent in J3 of this invention refers to inorganic and organic blowing agents that can be heated and cured easily in a composition mixed with a phenol resin initial condensate and decomposed to generate gas.

A typical example of these is N.

N'-dinitrosobentamedylenetetramine, benzenesulfonyl hydrazide, azobisisobutyronitrile,
? 't4 Mechanolytic blowing agents such as zodicarbonamide, para-toluenesulfonyl hydrazide, as well as small sodium carbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, azide compounds (e.g. (:, a Na
) and other inorganic decomposition type blowing agents. All of these are in powder form.

Addition of blowing agent) d is the required amount mainly taking into consideration the density of the desired foamed foam of Ia It', but it is 1 to 50 f[f suspension] per 100 weight ω parts of the phenolic resin initial condensate. parts by weight are suitable, preferably 2 to 25 parts by weight.

Hardeners are used in particular when novolak-type phenolic resin precondensates are used. This curing agent means a compound that can be decomposed by heating and can undergo a crosslinking reaction with the novolac type phenol resin initial condensate.

Such a compound is, like formaldehyde, a compound used to form a phenol resin through a reaction with phenols, and is usually in powder form.

Specific examples thereof include hexamethylenetetramine, paraformaldehyde, methylal, dioxolane, trioxane, tetraoxane, trimethylolphosphine, S-triazine, and the like.

The amount of the curing agent added is generally 1 to 30 parts by weight per 100 parts by weight of the novolac type J-Nol resin;
~15-fold suspension is preferred.

In addition, various other additives such as fillers such as clay may be added to the foamable phenolic resin product of the present invention. These additives are phenolic resin 10
It is preferable that the number is 100 cities and M divisions or less for 0 ■ oral divisions.

As for the aggregate particles used in this invention, the right g! 1f'l or inorganic particles or mixtures thereof,
It is preferable that the material does not react with the foamable phenolic resin composition.

Examples of inorganic materials include perlite, shirasu balloons, glass balloons, glass foam particles, glass fine particles, rock wool particles, slap, clay foam particles, sand, stone wax particles, and metallic particles. It will be done.

Examples of the material II'i1 include synthetic resin particles and foamed particles thereof, wood powder particles, paper powder, etc., but resins having heat resistance of 100° C. or higher are generally preferred, such as resol type phenolic resin foamed particles, Examples include styrene-maleic anhydride copolymer resin foam beads and polypropylene foam beads.

There is no particular limitation on the shape of the aggregate particles, and they may be spherical, pulverized fragments, or irregularly shaped.

The particle size ranges from micro particles with a particle size of 1 mm to particle sizes of 4 to 50.
Any grain size up to 1 mm may be used. The density of the aggregate particles is not particularly limited; when considering the use of light H1 foam molded products, it is sufficient to select those with a density of 1 g4 or less, and even high-density aggregates are not suitable. .

The filling chamber of the aggregate particles in the mold is preferably 100% to 10%, preferably 100% to 30%.

In this invention, first, the above-described foamable phenol b1 resin composition is introduced into the bottom of the mold, specifically the mold, so as to form a substantially uniform layer. This introduction should be adjusted to give a layer of as uniform thickness as possible. This process is shown in FIG. In the figure, (1) shows the granular layer of the expandable phenolic resin composition, (2) shows the mold, and (3) shows the granular layer of the expandable phenolic resin composition.
) indicates release paper. An appropriate surface material may be used instead of the release paper (3) for integration. Next, desired aggregate particles (5) are MM-filled onto the granular layer (1) and filled into the kitovity (4). At this time, it is necessary to stack the aggregate particles (5) and the granular composition so that they do not mix as much as possible. Also, the filling rate of aggregate particles is 10 depending on the purpose.
It can be changed from 0% to 10%. This process is as shown in FIG. In this way, the aggregate particles (5) are coated with the composition layer (
1) After filling the top with 5 layers, as shown in Fig. 3, the foamable phenolic resin composition is again sprinkled on the crosspiece stack of aggregate particles (5) to form a granular layer (1'). The encroachment mold (6) is formed almost uniformly, and then the terrain paper mark and appropriate surface material are placed on it.
The mold is closed and heated.

Heating may be carried out at a temperature at which the composition itself can be foamed and cured, and is usually carried out at 120 to 180° C. for about 3 to 20 minutes. By such heating, the granular composition at the bottom and top of the mold melts and hardens while foaming. At this time, the granular composition gradually expands upward and downward, respectively, and forms aggregate particles ( 5) and fills the cavity while expanding through the individual voids.

Then, the foamed phenolic resin composite (7'I) of the present invention shown in FIG. 5, in which each aggregate particle is bonded and integrated with a phenolic resin foam layer, is formed in a mold.

In some cases, as shown in FIG. 4, a granular layer (intermediate layer) (8) of a foamable phenolic resin composition may be further interposed within the aggregate particle layer. If the R of the granular layers formed on the bottom and top portions is insufficient in terms of the thickness and density of the intended foamed phenolic resin composite, it is suitable to form such an intermediate layer in advance. It is also possible to have more layers. At this time, the step (
If a multilayer structure is obtained by repeating ω and step +b+ a predetermined number of times, then J: Yes.

the hth part of the foamable phenolic resin composition forming a granular layer;
The porosity in one aggregate particle layer varies depending on conditions such as the intended foam density. Usually, the average density of the foamable phenolic resin composition is 5 (+/ρ
It is suitable to determine the suspension and thickness of the granular layer constituting the upper and lower layers or the upper and lower layers and the intermediate layer so that the thickness is 5 to 30.
It is preferable to set it to 0 g/i2.

Note that the mold used for the molding is a closed type as shown in the previous example, but it is appropriate that the mold be able to at least expel the air inside the mold during foaming.

lol of this invention! According to the LJ manufacturing method, a granular layer of a foamable phenolic resin composition is formed at the bottom and top of a mold, and then foam curing is performed to integrate the base material particles with a T-Nol resin foam layer. Therefore, it can be said to be a type of foamed composite with a sandwich structure in which the foam layer on the surface has a high density and the density inside is relatively low. As a result, the flexural modulus is significantly improved and the surface hardness is also improved.

(e) Examples Example 1 Dimensions inside the mold: height 25 mm, width 250 mm x 2
A mold having a diameter of 50 mm, a flat bottom surface, and a flat lid that could be opened and closed was used.

A release paper was placed on the bottom of the mold, and then 31.3 g of the foamable phenolic resin composition was spread to a uniform thickness to form a powder layer of the composition.

The composition at this time is 1! according to the following formulation. - A powdered product was used.

(51 foaming phenolic resin composition) (a) Uncured novolac type phenol-formaldehyde resin (melting point 81°C gelation time 150'C76 seconds 100
Metushpas remaining 0.5%) 100 parts by weight (b) Hekinamedylenedetramine (hardening agent) 10 parts by weight (c) Di-1-lopentamethylenetetramine (foaming agent) 10jll! Quantity: 1: Blend the above (a), (b), and (c) in a roll mixer at 80℃ and 10F.
Sufficiently mixed and pulverized 10 mesh pass powder) Next, 140 g of pearlite particles (trade name: Fuyolite; Fuyolite Industries Co., Ltd.) with an average particle size of 5 mm were placed on top of the above composition layer as aggregate particles in a mold. It was piled up without being substantially mixed with the composition and filled almost uniformly (filling degree 100%) into the mold. Further, on the top surface, the same foamable phenolic resin composition 31.39 as above is spread to a uniform thickness to form a powder layer of the composition,
After laying the release paper, cover the lid and heat at 150℃, press pressure 2.
Press heating was performed for 20 minutes at kOJ.

In the obtained phenol foam composite, pearlite grains were uniformly dispersed throughout the phenol foam, and when cut, the voids between the grains (40% porosity were completely filled with phenol foam, but the phenol foam on the surface The density of is 115kG4 and the surface density of the center is 87kg
It was 4.

The physical properties of this composite are shown in Table 3.

Example 2 A composite was produced in the same manner as in Example 1 except that 1 d of the foamable phenolic resin composition uniformly spread on the bottom and top surfaces was changed to 23.11 g.

As in Example 1, the r-norfoam 4-me composite had barley l-grains uniformly dispersed throughout the phenol foam, and when cut, it was found that the voids between the grains (porosity: 40%) was filled with all phenol foam, but the density of phenol foam on the surface was 98kQ/R, and the surface density in the center was [Yueoxg? Met.

The physical properties of this composite are shown in Table 1.

Example 3 A composite was produced in the same manner as in Example 1, except that 15.6Q of foamed RT foam resin was uniformly spread on the bottom, middle, and top surfaces.

The obtained phenol foam composite had pearlite grains uniformly dispersed throughout the phenol foam as in Example 1, and when cut, there were voids between the grains (porosity 40%).
was completely filled with phenol foam, but the density of the phenol foam on the surface was 58 kg. So the density at 7mm from the surface is 42 to 9? Met.

The physical properties of this composite are shown in Table 1.

Comparative Example-1 Average particle size 5. A phenol resin composition powder prepared under the same conditions as in Example 1 was granulated for 3 minutes using a pan-type granulator using Omm pearlite grains (trade name: Fuyorai I~, Fuyorite Industries Co., Ltd.) as an aggregate.

Note that water was used as the binder at that time, and was sprayed in a mist form from a nozzle. The raw material ratio during granulation was 200 cc (volume) of aggregate, about 3 cc of binder, and 80 Q powder of foamable phenolic resin composition.

Next, the coated particles obtained in this step were air-dried for a day and night, and
It was dried for 6 hours in a hot air circulation constant temperature bath at 0°C.

In the coated particles obtained in 1-1, the foamable resin composition powder was bonded to the surface of the aggregate pearlite particles (trade name: Fuyolite, Fuyolite Industries Co., Ltd.), and did not peel off even when handled roughly. . Note that this coating was not yet completely foamed and had an average thickness of 0.27 mm.

Next, the coated particles were placed on talc powder and foamed and cured for 30 minutes at a constant temperature of 160° C. using hot air circulation.

The obtained foam is yellowish and has a particle size of 10 to 14 mm.
It was a composite foaming method in which the foam had a spherical shape with a skin on its surface, pearlite was present inside (aggregate), and novolak type phenolic resin was present as a foam layer with a dense cell structure outside.

Next, this coated composite foaming method was filled into the same mold as in Example 1 (25 x 250 x 250 mm) to almost full capacity (100%), the lid was closed, and the mold was placed in a hot air circulation constant temperature oven at 160°C. The mold was then held for 1 hour.Then, the mold was taken out of the thermostatic oven, and the foamed molded article was taken out from the mold.

4r/phenolform complex is Barley 1-
The grains are evenly distributed throughout the phenolic foam,
When cut, all the voids between the grains (porosity 40%) were uniformly filled with phenol foam.

The physical properties of this composite are shown in Table 1.

Comparative Examples 2 and 3 Comparative Example ■ except that the suspension of the foamable phenolic resin coated on Barley 1~ (product name Fuco-Lite, Fuyo-Lite Industries Co., Ltd.) was changed to Go (1, SOG), respectively.
A composite was produced in the same manner.

In the obtained phenol foam composite, pearlite grains were uniformly dispersed throughout the phenol foam, and when cut, it was found that all the voids between the grains (porosity: 40%) were uniformly filled with phenol foam.

The physical properties of this composite are shown in Table 3.

(Margin below, continued on next page.) Table 1 *Bending test: According to JrS-Δ-9511.

*Surface hardness Rubber tester type
Measurements were made at 10 points using eC, and the average value was displayed.

*The amount of phenol used is expressed as 1 fft of powder (IJ)/molding mold internal volume H2).

(Also, hardness and density are for each foam layer.

Example 4 W uniform grains i ¥3, 7 mm foamed glass grains (product name: t? Robbies Yutaka [manufactured by 0 Bose Co., Ltd.])
A composite was produced in the same manner as in the example except that the weight was 170 g (filling degree 60%).

In the phenol foam composite obtained in Example 11, pearlite grains were almost entirely dispersed, and the spaces between each grain were completely filled with phenol foam. However, compared to Example 1, the gaps between grains were more uniform.

The physical properties of this composite were an apparent density of 133k(]q and a bending strength of 7.7kgf.

Example 5 100 parts of uncured novolac type phenol-formaldehyde resin (melting point 81°C gelation time 150°C 76 seconds 100 mesh pass remaining 035%), hex amount Nametylenete i~
Lamin 8 parts, dinitrosopentamethylene lenticin l-lamin 1
0 parts, Pronone 6208 (11hon Yushi Co., Ltd.>1)
One part was mixed in a mixer. (51% of the mixture was added to 2
Shaft pushing machine [y゛? Directional rotation (parallel 1111), L/D-
22), the lower part of the hopper is cooled to 50°C, and then the cylinder temperature is controlled to 30°C.
] - to rule. The temperature was controlled at 90℃, and the temperature was φ2 m.
The mixture was taken out from a cylinder of size m and cut into pellets. This pellet was non-foamed.

A composite was produced from this pellet in the same manner as in Example 1 of 71 Colors.

The obtained phenol foam composite had pearlite grains uniformly dispersed throughout the phenol foam as in Example 1. When cut, the voids between the grains (porosity 40%)
〉 was completely filled with phenol form, but the density of 1 phenol form on the surface was 110 kg, and the density in the center was 9.
It was 0X+J.

The physical properties of this composite were a shearing force tG-1 density of 150 kg4, a bending modulus of elasticity of 1480, and 9 fJ.

Example 6 Twin-screw extrusion machine, cylinder temperature 95°C, mold temperature 11
A primary foamed cylindrical phenol foam was produced in the same manner as in Example 5 except that the temperature was changed to 0°C.

-The average size of the cylindrical phenol foam after foaming is 5 mm.
The diameter was 6 mm and the apparent density was 400 ka core.

A composite was produced from this post-foamed cylindrical phenol foam in the same manner as in Example 1. As in Example 1, the phenol foam composite obtained had pearlite grains uniformly dispersed throughout the phenol foam, and when cut, it was found that the voids between the grains (porosity: 40%) were completely filled with phenol foam. However, the density of the phenol form on the surface is 113kQ-J, and the density in the center is 88k(II,
It was f7.

The physical properties of this composite were an apparent density of 1 sokaJ and a flexural modulus of 1450 kg'4.

Example 7 To 100 parts by weight of resol-type phenol vA fat initial combined powder was added a 10-width suspension of dinitrosobentimethylenetetramine as a blowing agent, and the mixture was kneaded using heated rolls. Thereafter, it was pulverized to obtain a powdered resin composition. This foamable resin composition had a melting point of 75° C. after 100 mesh passes.

Apply the above resol type phenolic resin Hatsutomo i1 uniformly on the bottom and top surfaces. The composite was prepared in the same manner as in Example 1, except that 31.3 l (31.3 l) of each of the three layers were laid.

1? As in Example 1, the phenol foam composite thus obtained had pearlite grains uniformly dispersed throughout the phenol foam, and when cut, there were voids between the grains (porosity 60%).
) was filled with all phenol foam, but the density of phenol foam on the surface was 113 kg, and the surface density in the center was 82 to 94 in Q. This complex fF
Apparent density 1bOkG4, bending modulus 1470kg
It was fJ.

Comparative Example-4 A composite was produced in the same manner as in Example 1, except that pearlite particles and a foamable phenolic resin composition were mixed and filled.

When the pearlite grains and the foamable phenolic resin composition were mixed, some of the pearlite grains were lost and pearlite powder was generated. The phenol foam composite was packed to make it as uniform as possible to prevent disproportionation of the mixture, but the resulting phenol foam composite had only a phenol foam layer in some parts.
Furthermore, the composite was non-uniform with air pockets partially occurring inside the composite. This air pocket is thought to occur because the foamable phenol resin composition is heated to the upper and lower surfaces and foams, so there is no space for air to form.

(f) Effects of the invention According to the method of the invention, it is possible to extremely easily produce a foamed phenolic resin composite having a high flexural modulus and high surface hardness.
9. Since the phenol foam composite of the present invention thus obtained is made of phenol foam containing aggregate particles, it is useful for applications requiring fire-resistant properties, such as heat-resistant materials, panel core materials, and ceiling 1F44. In particular, a phenol foam composite board molded using a plate-shaped mold can be suitably used as a building exterior board (sizing board) by laminating it with a metal plate.

[Brief explanation of drawings]

1 to 5 are configuration explanatory views showing each step of the manufacturing method of the present invention, respectively. (1), (11'), (81...grain layer, (2)...mold, (5)...
Aggregate particles, (6)... upper mold, (sword...
...Foamed phenolic resin composite.

Claims (1)

[Claims] 1. A granular foamable phenolic resin composition consisting of a phenolic resin initial condensate, a decomposable foaming agent, and a curing agent added as necessary is introduced into a mold, and the foam is applied to the bottom of the mold. forming a granular layer of the composition, then (a) loading aggregate particles onto the granular layer without substantially mixing them with the granular layer to form an aggregate particle layer; and (b) The step of spraying the foamable phenolic resin composition again on the aggregate particle layer to form a granular layer of the composition is repeated once to multiple times to coat the bottom and top portions with the foamable phenolic resin composition. A composite layer comprising a granular layer with an aggregate particle layer optionally interposed therebetween and a layer of a foamable phenolic resin composition is formed, and then the mold is heated in a closed state to form a foamable phenolic resin composition. A method for producing a foamed phenolic resin composite, which comprises foaming and curing.