JPS61103943A - Resole-type phenolic resin foamed article containing aggregate particle - Google Patents

Abstract

PURPOSE:To obtain the titled foamed article containing uniformly dispersed aggregate, having excellent dimensional stability and heat-insulating effect, and suitable as a heat-insulation panel for building, by using particles prepared by coating aggregate particles with a foamable solid resin composition containing a resol-type phenolic resin precondensate and a decomposition-type foaming agent. CONSTITUTION:A foamable slid resin composition containing 100pts.wt. of a solid resol-type phenolic resin precondensate and 1-50pts. of a decomposition- type foaming agent (e.g. N,N'-dinitrosopentamethylenetetramine) is attached in molten state to aggregate particles consisting of organic particles (e.g. foamed particles of resol-type phenolic resin) and/or inorganic particles (e.g. perlite). The amount of the foamable resin composition is >=5g, preferably 15-500g per 1 liter of the particle. The obtained particles are filled in a mold, and heated to obtain a uniformly foamed article.

Description

Detailed Description of the Invention (a) Object of the Invention (Field of Industrial Application) This invention relates to a resol type phenolic resin foam molded article containing aggregate particles.

(Prior Art) Conventionally, a foamable resin composition prepared by mixing a resol-type phenolic resin initial condensate and a required amount of a decomposition-type blowing agent is usually used after being pulverized, and the size of the powder is 100%.
It is normal for the mesh to be more than that and the bulk specific gravity to be less than 1.

(Problems to be Solved by the Invention) However, in order to obtain a phenolic resin molded article by mixing this composition with other particles, it is necessary to obtain a molded article of phenolic resin by mixing this composition with other particles, and the size of the particles is 1 knit or less and the bulk specific gravity is the same as that of the above composition. If the mixture is not at the same level as the above, it is difficult to obtain a uniform mixture, and even if the mixture is heated and foamed, it is extremely difficult to obtain a uniformly foamed phenol resin molded product.

In view of the above circumstances, the inventors of the present invention have determined that when obtaining a phenolic resin molded article, aggregate particles that are not reactive with the foamable resin composition to be coated, regardless of the shape, size, bulk specific gravity, etc. The inventors discovered the fact that a uniform phenolic resin foam molded product can be easily obtained by coating the composition in advance, filling a mold with the foamable resin-coated particles, and heating the molded product. Reached.

(B) Structure of the Invention Thus, according to the present invention, the foaming material is a solid foamable resin composition in which the aggregate particles contain a solid resol-type phenolic resin initial condensate and a decomposable blowing agent as essential components. A resol-type phenolic resin foam molded article containing aggregate particles is provided, which is made of covered expandable resin-coated particles and is characterized in that aggregate particles are substantially uniformly dispersed.

When heated, the expandable resin-coated particles become a heat-insulating granular material containing aggregate on the inside and covered with a resol-type phenolic resin foam layer on the outside.

For example, if the particles of the present invention are filled into a mold or the like and heated, a phenol molded body in which aggregate particles are uniformly dispersed in the phenol foam can be obtained.

The resol type phenolic resin initial condensate, which is the main raw material of this invention, is a so-called resol type phenol resin known in the art, which is obtained by reacting phenols and excess aldehydes in the presence of a basic catalyst. Also known as acid curing acceleration.

It means a substance that can undergo polymerization by using an agent and heating.

Such a resol type phenolic resin contains about 20% of reaction water.
This is a liquid product containing 1% water, but this is further dehydrated (evaporates water) to form a solid product (containing about 1% water), and this solid product is then crushed and used in the present invention. Powdered resol type phenolic resin.

In addition to phenol, the above-mentioned phenols include 3.5-xylenol, m-cresol, 2.5-xylenol,
Includes 8.4-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 this invention means an inorganic or organic blowing agent that can decompose and generate gas during heat curing in a composition mixed with a resol type phenolic resin initial condensate. Typical examples of these include organically decomposed blowing agents such as N,N'-dini, trosopentamethylenetetramine, benzenesulfonyl hydrazide, azobisisobutyronitrile, azodicarbonamide, paratoluenesulfonyl hydrazide, and sodium bicarbonate. , ammonium carbonate, ammonium bicarbonate, ammonium nitrite, and azide compounds (eg, CaN). All of these are in powder form.

The amount of the blowing agent to be added is the required amount, mainly taking into account the density of the desired final foam, but 1 to 50 parts by weight is appropriate for 100 parts by weight of the resol disc phenolic resin.
4 to 8 parts by weight is preferred.

The foamable resin composition of the present invention may contain small amounts of various other additives, such as fillers such as clay. The amount of these additives is preferably 100 parts by weight or less per 100 parts by weight of the resol type phenolic resin.

The foamable resin composition in this invention is usually produced by kneading its components, such as a resol-type phenolic resin initial condensate and a decomposition-type blowing agent (and other additives), using heated rolls, etc., to uniformly mix them, and then pulverizing them. It is used in powder form with an outer diameter of 1 mm or less.

Of course, granules may also be used.

The aggregate may include organic or inorganic particles or mixtures thereof, but preferably aggregates that do not react with the foamable resin composition.

Examples of the inorganic material include perlite, shirasu balloons, glass balloons, glass foam particles, glass cotton particles, rock wool particles, slap, clay foam particles, sand, plaster particles, and metallic particles.

Examples of the organic material include synthetic resin particles and foamed particles thereof, wood powder particles, abrasive grains, etc., but resins having a heat resistance of too"c or more are usually preferable, such as resol type phenol resin foamed particles, styrene-anhydrous. Examples include foamed maleic acid copolymer resin beads and foamed polypropylene beads.

There is no particular limitation on the shape of the aggregate particles, and they may be spherical, pulverized fragments, or irregularly shaped. The size of the particles may be any size from microscopic particles with a particle size of 12 to large particles with a particle size of 40 to 50 am. The density of the aggregate particles is not particularly limited, and when considering the use of lightweight foam molded products, the density of the aggregate particles is 1 g.
/i or less may be selected, and high-density aggregates may also be used.

The method of coating the aggregate particles with the foamable resin composition includes a temperature range that allows the foamable resin composition in powder form to melt and adhere;
In other words, aggregate particles are heated from the softening point of about 70°C to about 110 to 120°C, which is the point of foaming and hardening, and in this state, the foamable resin composition (powder form) is sprayed and sprinkled. There is a method in which coated particles are obtained by bringing the foamable resin composition into contact with the foamed resin composition, or, conversely, a method in which the foamable resin composition is heated and softened to coat the aggregate particles.

Another method is to use a binder. Typical binders include water, methyl alcohol, toluene, and the like. Among these, water is most preferred. When such a binder is used, for example, the aggregate particles and the powdered foamable resin composition may be rolled together in a pan-huang granulator while spraying the binder. When these binders are used, it is preferable to remove the binders by drying after coating and granulation. This is because, for example, if water remains, it may have an adverse effect on the expansion ratio and bubbles. Further, any binder may be used as long as it does not adversely affect the foaming process. For example, other binders that may be used include an 8-5% aqueous solution of sticky polyvinyl alcohol, silicone oil, animal and vegetable oils, and the like. When these binders are used, they remain in the coated particles of the present invention, and such coated particles are also included in the present invention.

The amount of coating of the foamable resin composition on the aggregate particles varies depending on the foamability of the composition, the type and shape of the aggregate, etc., but it is usually necessary to cover 5f weight or more per liter of aggregate particle volume. A good coating amount is 15 to 600 f.The better the coating condition during molding is that the composition is evenly coated on the aggregate particles, but when obtaining a molded article, even if the coating condition is mottled, I don't care.

Incidentally, the coating resin composition of the obtained expandable resin-coated particles of the present invention may be a composition having secondary foamability in which the coating resin composition is partially foamed and cured.

Such expandable resin-coated particles can be formed into a foam molded article of any shape. For example, if an indoor room having a desired shape is filled with a foamable resin composition, usually 20 to 100% of its bulk volume, and heated to a predetermined temperature (for example, 150 to 180' (46 degrees)), each particle will easily expand. , it can be made into a fused and integrated foamed molded product.

(c) Effects of the Invention The foamed molded product obtained by this invention differs from a foamed product obtained by simply mixing a foamable resin composition and aggregate particles, in that the aggregate is substantially uniformly contained in the foamed product. It is dispersed. Here, a molded product in which aggregate particles are substantially uniformly dispersed means that aggregate particles are not present only in the surface layer or center of the molded product. Therefore, a molded body in which aggregate particles are substantially uniformly dispersed can be obtained, so such a molded body has high dimensional stability, uniform heat insulation effect, etc.
They have various quality characteristics. Furthermore, during foam molding, it has been recognized that aggregate is substantially uniformly dispersed in the foam molded product even at a filling rate as low as 20% of the bulk volume.
This is a novel surprise discovered by the inventors of this invention (
7. The shape of the molded article of the present invention is not particularly limited, but may be plate-shaped, cylindrical, or the like.

For example, if it is plate-shaped, it can be used as a heat insulating board for construction.
If it is cylindrical, it can be used as a heat insulating material to cover pipes. Furthermore, this molded product is very lightweight and has excellent adhesion to other objects (for example, iron plates, etc.), so it is suitable for use with composite molded products such as sizing boards and the like. In addition, the resol type phenolic resin of the foam layer is flame retardant and is widely used as a nonflammable foam molded product.

(!!Example) Next, the present invention will be described with reference to Examples, but the present invention is not limited thereby.

Example 1 10 parts by weight of blowing agent dinitrolipentamethylene per 100 parts by weight of a powdered resol type phenolic resin with a flow rate of 70 to 100 m+ at 126°C, a gel time of 85 to 105 at 150″C, and a softening point of 73°C. Chitramine was mixed to obtain a powdered foamable resol type phenolic resin composition.

Next, the average particle size is 5. The above resin composition powder was granulated for 8 minutes using a pan-type granulator using a resol-type phenolic resin spherical multifoam of θ-Rin as aggregate particles. In this case, methyl alcohol (special grade reagent) was used as the binder and was sprayed in a mist form from a nozzle.

The ratio of raw materials during granulation is 1000 cc (volume) of aggregate, 8 cc of binder, and 80 cc (volume) of powder resol disc phenolic resin composition.

l. Next, the coated particles obtained in this factory were air-dried for a day and night at 60℃.
It was dried for 8 hours in a hot air circulation constant temperature bath.

The obtained coated particles have a dark brown foamable resin composition powder dissolved on the surface of the aggregate (resol type phenolic resin foamed particles) and are fused to form a thin film, and the powder is disordered. It did not peel off even when handled with care. Note that this coating was not yet completely foamed and had an average thickness of 56 μm.

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

The obtained foam is yellowish brown, has a particle size of 6 to 9 m, and is spherical with a skin on the surface.Resol-type phenolic resin foam particles are present inside (aggregate), and the outside has a dense cell structure. The foam layer was a composite foam region in which resol type phenolic resin existed.

This coated composite foam area is then placed in a metal mold (220X2
The mixture was filled into a 20 x 25 cm container to almost full capacity (100%), the lid was closed, and the mixture was kept in a hot air circulation constant temperature bath at 160° C. for 1 hour. After that, the mold was taken out of the thermostatic oven, and the foam molded article was taken out from the mold.

In this foamed molded product, the powder resol type phenolic resin foam layer on the surface further expands, and the powder resol type phenol resin foam layer with a dense cell structure fills all the voids between the filled particles, completely filling the spaces between the particles. It was a resol type phenolic resin foam molded product in which the aggregate (resol type phenol resin foam particles) was uniformly dispersed. Unfortunately, the density of this molded product was 20014/g.

In addition, when a metal mold is filled with 50% of the bulk volume of the composite foamed region and heat-formed, the aggregate is uniformly dispersed in the molded product, and the spaces between the particles are yellow foamed at a high magnification. It is a molded product completely filled with a powdered resol type phenolic resin foam layer with a colored and dense cell structure, and the density is 100#/
It was on display.

Examples 2.8 and 9 are other examples of granulation using methyl alcohol and trichlorotrifluoroethane (Fllg) as binders.
Table 1 includes Example 1. Note that the ratio of raw materials during coating is the same as in Example 1.

(C below Kamashiro, continued on next page) 97! Example 6 A powder of a foamable resin composition was prepared in the same manner as in Example 1.

Next, the resin composition powder was coated using a pan-shaped granulator using foamed glass (trade name: Cellobeads, manufactured by Toyota Boshoku Co., Ltd.) having an average particle size of 8.7 as an aggregate. Note that water was used as the binder at that time, and was sprayed in a mist form from a nozzle.

In addition, the raw material ratio at the time of coating is 1000cc of aggregate (
The binder has a volume of 10 cc, and the resol type phenolic resin composition powder has a volume of 80 cc.

Next, the coated particles obtained in this step were air-dried for a day and night, and
It was dried for 4 hours in a hot air circulation constant temperature bath at ℃.

The obtained coated particles had the foamable resin mixture powder bonded to the surface of the aggregate (foamed glass particles), and the coating did not peel off even when handled roughly. Note that this coating was not yet completely foamed and had an average thickness of 80 μm.

Next, the coated particles were placed on talc powder and foamed and hardened for 80 minutes in a hot air circulation constant temperature bath at 160°C.

The obtained foam is yellowish brown, has a particle size of 5 to 8, has a skin on the surface, and is a spherical resol type phenol covered with a foam layer with a dense cell structure containing foamed glass particles inside. It was a resin composite foam ball.

Examples 6, 7 and 8 Other examples coated using water as the binder are shown in Table 2, including Example 5. Note that the ratio of raw materials during coating is the same in all cases.

(The following margins are continued on the next page.) Example 9 The powder of the foamable resin composition was 5i! Adjustments were made in the same manner as in Example 1.

Next, the resin composition powder was coated using a pan-shaped granulator using foamed glass having an average particle size of 8.7 as an aggregate.

In addition, the binder at that time has a molecular weight of 190 to 210.
Polyethylene glycol was used and sprayed from a nozzle. In addition, the raw material ratio at the time of coating is aggregate 1000c
c (bulk), the binder was 10 cc, and the resol type phenolic resin composition powder was 80 cc (bulk).

Next, the coated particles obtained in this step were placed in an apparatus overnight.

The obtained coated particles had the foamable resin mixture powder attached to the surface of the aggregate (foamed glass particles) due to the presence of a binder, and did not peel off even when handled roughly. .

Note that this coating had an average thickness of 65 μm.

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

The obtained foam has a brownish color and a particle size of 6 to 9 cm, has a skin, has foamed glass particles inside, and is a spherical resol type phenolic resin composite foamed sphere covered with a surface layer of a foamed layer. Met.

Example 10 A powder of a 0° foamable resin composition was prepared in the same manner as in Example 1.

Next, foamed glass with an average particle size of 8.7 fl was heated for 2 hours in a hot air circulation thermostat at 180°C, quickly taken out of the tank, and heated in a pan-shaped granulator pre-adjusted to an atmosphere of 60°C. The above-mentioned resin composition was poured into the powder and coated.

The raw material ratio at the time of coating is 1000 cc (volume) of foamed glass particles as aggregate to 1000 cc (volume) of resol. It was softened and melted and adhered to form a uniform thin film, but this film did not peel off even when handled roughly. Moreover, this coating had an average thickness of 45 microns.

Next, the expandable coated particles are placed on talc powder and 16
It was foamed and cured for 80 minutes in a hot air circulation constant temperature bath at 0°C.

The resulting foam is a resol-type phenolic resin composite foam sphere that is yellowish brown in color, has a skin with a particle size of 6 to 9, and is covered with a foam layer with a dense cell structure containing foamed glass particles inside. Met.

Agent: Patent Attorney Shintabe Nogawa One flight

Claims (1)

[Claims] 1. As a foaming material, aggregate particles are covered with a solid foamable resin composition containing a solid resol type phenolic resin initial condensate and a decomposable foaming agent as essential components. 1. A resol type phenolic resin foam molded article containing aggregate particles, characterized in that the aggregate particles are substantially uniformly dispersed. 2. The molded article according to claim 1, wherein the aggregate particles are organic or inorganic particles or a mixture thereof. 3. The molded article according to claim 2, wherein the organic particles are foamed particles of a resol phenolic resin or foamed styrene-maleic anhydride copolymer resin particles. 4. The molded article according to claim 2, wherein the inorganic particles are perlite, shirasu balloons, glass balloons, glass foam particles, glass cotton particles, rock wool particles, or crushed products thereof. 5. The molded article according to claim 1, wherein the foamable resin composition is in powder form, and the size thereof is smaller than the size of the aggregate particles. 6. The molded article according to claim 1, wherein the amount of the foamable resin composition used per liter of aggregate particles is at least 5 g.