JPH04132629A - Production of foamed molded article - Google Patents

Abstract

PURPOSE:To inexpensively obtain a foamed molded article having excellent heat insulating properties, water absorption resistance, etc., by blending glassy foamy particles having given particle diameter with a stock solution of a polymer consisting essentially of an isocyanate, putting in a molding frame, treating with a blowing agent and packing the foamed polymer among the glassy foamy particles. CONSTITUTION:Glassy foamy particles having about 1-several mm particle diameter are blended with a stock solution of a polymer comprising an isocyanate as a main agent. Then the prepared blended raw material 4 is fed from a hopper 3 between traveling belts 1 and 2, the polymer is polymerized under heating in a thermally treating tank 5 to mutually bond the glassy foamy particles. Further, a blowing agent 6 (e.g. water) is introduced from small holes bored through the belt 1 and/or the belt 2 into the blend, the unreacted isocyanate is polymerized, foamed and the foamed polymer is packed among the glassy foamy particles to give a foamed molded article. The prepared foamed molded article is suitably used as building material, heat insulating material, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is lightweight and has excellent heat insulation properties, and can be used as building materials, fixtures, furniture materials,
The present invention relates to a method for producing a multicellular molded body that can be applied to heat insulating materials and the like.

[Prior art and its problems] The use of glassy foam as building materials and insulation materials has increased in recent years, and the production volume has increased significantly.
There is also a large amount of glassy foam waste generated during its manufacture and processing.

Conventionally, the above-mentioned layer has been reused by pulverizing it and reusing it as a raw material for glassy foam, but pulverization requires high costs, and the swarf itself already contains glass and blowing agents, etc. - for example. Since the glass is altered due to the reaction with the calcium content in the calcium carbonate foaming agent, there are disadvantages such as difficulty in foaming again and changes in the foaming temperature, and no effective means have yet been found.

In the known technology, Japanese Utility Model Application Publication No. 58-97130 discloses a composite molded article in which a thermoplastic foam is filled between the particles of natural vitreous foam particles, and as a means for producing the same, natural vitreous foam particles are placed in a molding frame. Then, between the particles, particles containing a foaming component of thermoplastic resin such as boris dylene or polyethylene are filled and heated, or the resin particles are preliminarily applied to the surface of the natural glassy foam particles. Although heating the foam is mentioned, these methods deteriorate the foaming efficiency of the thermoplastic foam between the natural glass foam particles, make it difficult to obtain a foam with uniform bubble diameter, or heat the foam. The plastic foam does not effectively fill the spaces between the natural vitreous foam particles, and sometimes cavities are formed. Furthermore, the above-mentioned resins have many problems such as poor adhesion to glass.

Furthermore, JP-A No. 60-31921 describes an inorganic heat insulating material in which a mold is filled with a mixture of an inorganic foam such as vermiculite and a catalytic gas-curable binder, such as urethane, and then the binder is cured with a catalytic gas. Although disclosed, it does not cause the binder to foam,
If too little binder is used, cavities will be created between the inorganic foam particles, resulting in poor airtightness, poor water absorption resistance, and poor insulation properties.
On the other hand, if the amount is too large, the spaces between the particles of the inorganic foam will be filled with non-foamed binder, impairing the heat insulation properties, and the raw material cost will increase due to the large amount of binder used.

The present invention provides a method for manufacturing a multi-cellular molded product that effectively utilizes the waste of the vitreous multi-foamed material, can be produced by extremely easy means, and fills the space between the vitreous multi-cell particles with a polymer rich in closed cells. The purpose is to

Means for Solving Problem F] In the present invention, glassy cellular particles having a particle diameter of approximately 1 to several mm and a polymer stock solution containing isocyanate as a main ingredient are charged into a molding frame in a mixed state, and heated. the glassy foam particles are bonded to each other, a blowing agent is introduced to polymerize and foam unreacted isocyanate, and the space between the glassy foam particles is filled with a foamed polymer; In addition to the fact that the raw solution contains polyol, a mixed raw material consisting of glassy foam particles and a polymer stock solution is introduced between a pair of upper and lower running belts, guided to a heat treatment zone and heated, and a blowing agent is added. In addition, the surface of the multifoamed molded product is coated with a fluorine-containing polymer.

Conventionally, vitreous foams are produced by putting a mixture of soda-lime-based glass powder, a blowing agent, or even heat-resistant inorganic powder and pigments into a molding frame, heat-treating and foaming, and molding this into the desired size as needed. , cut into shapes and make products.

At this time, lumps of vitreous foam are produced, which are crushed to an appropriate particle size and used as a raw material, that is, vitreous foam granules.

Of course, it is also possible to form glassy cellular particles by forming the raw material together with a binder into granules and heating and foaming them by known means, but it is preferable to use the scraps that are easily available in paper warehouses.

The particle size of the vitreous multicellular particles is approximately 1 mm to several mm; if the size is significantly smaller than 1 mm, the bubbles within the vitreous multicellular particles themselves will be crushed, resulting in poor properties such as heat insulation and lightness. On the other hand, if the size is large (nearly 10 mm), it will be easily crushed and worn out during transportation, storage, mixing, etc., making it difficult to exhibit the above-mentioned properties, and the cutting processability of the resulting multicellular molded product will be reduced. worsen.

As the incyanate, known toluene diisocyanate, diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, p-phenylene diisocyanate, m-xylylene diisocyanate, tetramethylxylene diisocyanate, triphenylmethane diisocyanate, etc. are employed.

Furthermore, foam stabilizers such as silicone, catalysts such as triethylamine,
Other additives such as crosslinking agents, colorants, flame retardants, etc. can be added as appropriate.

Incyanate itself undergoes addition and polymerization reactions to form isocyanurate and other polymers, which firmly adhere to glassy and ceramic articles such as glassy foam particles.

Further, when isocyanate is reacted with a blowing agent, such as water, polyurea is formed, and carbon dioxide gas is released to produce a blowing action.

The above-mentioned isocyanate-added products, polymers, polyureas, etc. are rich in toughness, but on the other hand, they lack flexibility. ! It is vulnerable to attacks such as 1i attacks.

Therefore, by introducing an appropriate amount of polyol, isocyanate-1.
It is preferred to form a polyurethane that improves brittleness by reaction with the polyurethane.

As the polyol, hundreds to thousands of molecules made from ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, ethylenediamineoxypropylate, jetanolamine, aminoethylethanolamine, etc. are used.

When producing a cellular molded article, an appropriate amount, preferably 0.1 to 0.3 parts by weight, of a polymer stock solution containing the isocyanate as a main ingredient is mixed with one part by weight of the glassy cellular particles; After being put into a molding frame, it is heated at a temperature between 30° C. and 100° C. or less for one to several hours, thereby bonding the glassy cellular particles to each other with the addition of isocyanate and the polymer. Further, a blowing agent, such as water, is introduced between the grains to react with unreacted isocyanate, releasing carbon dioxide gas, forming polyurea, and filling the spaces between the grains with foamed polymer.

In order to continuously produce a cellular molded product, the glassy cellular particles are placed directly between a pair of running upper and lower belts, but after applying a mold release agent such as wax, soap, or oil to the belt surface, A mixed raw material consisting of a polymer stock solution is introduced, or the mixed raw material is introduced between the upper and lower belts through an upper and/or lower surface material film, such as an aluminum sheet, a polyethylene coated glass fiber sheet, or a plastic film. The glassy foam particles may be introduced into a heat treatment zone and heated to a temperature of 30° C. to 100° C. or lower to adhere the glassy foam beads as described above, and then a foaming agent such as water may be introduced to cause foaming.

The facing material film acts as a facing material, a reinforcing material, an airtightness enhancing material, and the like.

Alternatively, by applying a fluorine-containing polymer to the surface of the foamed molded product by spraying, brushing, or other known means,
It can improve heat resistance, water repellency, weather resistance, chemical resistance, etc., and can also add decorative properties.

The attached FIG. 1 is a side sectional view without showing the continuous manufacturing means, and shows small holes (not shown) drilled in the hopper set, and also in the belts 1 and/or 2, between the lower running belts 1 and L2. As shown in 6 (arrow) from 1), water is sprayed to cause foaming.

In the cellular molded product thus formed, the glassy cellular particles are bonded and integrated with each other by the polymer, and the spaces between the particles are filled with the foamed polymer, making it possible to obtain a lightweight product with excellent heat insulation properties. .

[Examples and comparative examples] Examples of the present invention will be described below in comparison with comparative examples.

Large-scale vitreous foam particles used as a raw material were lumpy debris produced during the production of soda-lime-based vitreous foam particles, which were pulverized with an impact crusher to a particle size of 1 to 3 mm.

Toluene diisocyanate was used as the isocyanate, a propylene oxide polyol (molecule placement number 1000) was used as the polyol, tin octylate was used as the catalyst, trimethylamine was used as the catalyst, and water-soluble polyether siloxane was used as the foam stabilizer. Water was prepared as an agent.

Isocyanate per 100 parts of the glassy foam particles)
15 parts by weight were mixed, and further 3 parts by weight of polyol, trace amounts of the first catalyst and foam stabilizer were added and mixed. This was placed in a mold whose inner surface was coated with release wax in advance, set in a heat treatment tank and kept at 50°C for about 60 minutes, and then several tens of sand particles were inserted into the hole pre-drilled in the mold at the rear end. Water and a second catalyst solution were introduced and left at room temperature.

The foamed molded product obtained after removal from the mold shows a morphology in which the spaces between the glassy foam particles are filled with foamed polymer, which has some open cells but mostly closed cells, and its bulk specific gravity is 0.9, bending strength is 22kg/cffl.

Room temperature thermal conductivity 0.09Kcal/m, hr, °C, 2
Water absorption rate after immersion in water for 4 hours: 1. ．． It was 2 wt%, and could be sufficiently used as a wall material, for example.

Zoo fence I When a fluorine-containing polymer related to the trademark "Cefral Coat" manufactured by Central Glass Co., Ltd. was spray-coated on the entire surface of the multicellular molded product obtained in Example 1, the thermal conductivity was as shown in Example 1.
The water absorption rate was reduced by about 20% compared to the previous year, improving the heat insulation properties, and the water absorption rate was almost 0, which was extremely good.

Of course, it is not actually necessary to apply the fluorine-containing polymer to the entire surface; for example, when it is used as a wall material, it may be applied to the exposed surface as desired.

I and 100 parts by weight of the same glassy foam particles as in Example 1 were mixed with 10 parts by weight of polyol, first and second catalysts, water and some amount of foam stabilizer, and further mixed with 10 parts by weight of isocyanate. The sample was placed in a mold and heat treated in the same manner as in Example 1. In this comparative example, the aim was to form polyurethane foam through the reaction of isocyanate and polyol.

However, the glassy foam particles are unevenly distributed downward in the mold.
The foamed polyurethane layer was formed on top of the solid-liquid separation, and the desired multifoamed molded product could not be obtained.

10 parts by weight of the same glassy foam particles as in Example 1 were mixed with 10 parts by weight of polyol, and then 1 part by weight of isocyanate was added.
After mixing 0 parts by weight, it is put into a mold, and the second catalyst is introduced through the mold hole without heat treatment, and the glassy cellular particles are bonded and integrated by the reaction product of polyol and isocyanate, polyurethane. A multifoamed molded article was obtained.

In the multicellular molded product, the spaces between the glassy foam particles are not sufficiently filled with foamed urethane, and cavities are formed between the particles and have air permeability, allowing moisture to easily penetrate, and the bulk specific gravity is 1.
0, bending strength is 19kg/cnf, thermal conductivity is 0.1
5 Kcal/m, hr, °C, and water absorption rate of 6.9 wt%, which is clearly inferior to the examples.

As is clear from the above, this example has excellent heat resistance conductivity (insulation), water absorption resistance, etc. because the spaces between the glassy foam particles are mostly filled with closed cell foam polymer, and it is easy to manufacture. It is possible.

[Effects of the Invention] According to the present invention, the spaces between the vitreous foam particles are almost completely filled with closed-cell foamable polymer, and the vitreous foam granules have excellent heat insulation properties, water absorption resistance, etc. It has the advantage of being able to utilize the waste material of high quality foam and being easily manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing one manufacturing means according to the present invention. 2 running belt

Claims (1)

[Scope of Claims] 1) Glassy cellular beads with a particle size of approximately 1 to several mm and a polymer stock solution containing isocyanate as the main ingredient are put into a molding frame in a mixed state, and heated to form glassy cellular particles. In addition to bonding them together, a foaming agent is introduced to polymerize unreacted isocyanate.
1. A method for producing a multicellular molded article, which comprises foaming and filling spaces between the glassy multicellular particles with a foamed polymer. 2) The method for producing a multicellular molded article according to claim 1, characterized in that the polymer stock solution contains a polyol. 3) A claim characterized in that a mixed raw material consisting of glassy foam particles and a polymer stock solution is introduced between a pair of upper and lower running belts, guided to a heat treatment zone, heated, and foamed by introducing a foaming agent. 2. The method for producing a multifoam molded article according to 1 or 2. 4) The method for producing a multi-cellular molded article according to any one of claims 1 to 3, characterized in that the surface of the multi-cellular molded article is coated with a fluorine-containing polymer.