JPS6119310A - Foam molding process - Google Patents

Abstract

PURPOSE:To contrive to mold easily a uniform foam by a method in which after the liquid raw material for a foam and solid raw material have been supplied onto the rotary member with the projected pieces of a mixer and dispersion-mixed, while said mixture is taken out of the mixer and foamed. CONSTITUTION:In a raw material feeding chamber 1, each component of raw material is continuously fed to each annular liquid tank 11, 21, 31 through each sprue 10, 20, 30 from each liquid tank at the rate of foaming compounding, and it overflows from each edge 12, 22, 32 of the annular liquid tanks, whereby it flows down continuously on each inner wall surface 13, 23, 33 of the annular liquid tanks in the state of thin films. The raw materials which are to react one another are separately kept not to be in contact mutually, until they reach the rotary member 41 of a mixer 2. When liquid raw material for a foam and solid raw material drop in the center of the rotary member 41, as the rotary member 41 is rotated at 500- 5,000rpm, said materials are mixed and agitated with shearing action by centrifugal force and projected pieces 42 and further are mixed due to the discharging resistance by blades 44. Said mixture is continuously discharged from a discharging port 47. The mixture which is sent out, while distributing the solid raw material uniformly, is foam-molded. From the point of view of molding operation, the mixed raw material for the foam is necessary to be taken out at unfoaming state, and therefore in general, its keeping time is equal to or less than 30 seconds. Thus, the product has no void and has fine cells, especially solid raw material is uniformly dispersed therein. Each characteristic corresponding to each solid raw material may be sufficiently displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for continuously molding a foam in which a liquid raw material for foam and a solid raw material such as powder or short fibers are uniformly dispersed.

[Prior art and its problems]

Conventionally, various additives have been used in the production of foams in order to impart various properties to the final product or to reduce costs. For example, to increase strength and fire resistance, glass fiber, carbon fiber or other fibrous materials, silicic acid, etc.
Inorganic substances such as metal salts of silicic acid, boric acid, metal salts of boric acid, zinc acetate, and sodium sulfate are used, and rust preventives and neutralizing agents are used to prevent corrosion. Additives used to reduce costs include fillers such as lime, gypsum, cement, barium sulfate, etc., or foam powders made from foam waste.

The introduction of such additives into the reaction mixture has already been attempted in various ways. For example, additives are mixed with raw materials in advance and supplied to the raw material tank, mixed with additives in the raw material tank, premixed during supply from the raw material tank to the mixing head, and mixed with additives and liquid raw materials for foam. Methods include simultaneous mixing at the head, spraying the additive onto the reaction mixture, and #&mixing, such as spraying the additive onto the face material or mold, but each method has its own problems. That is, in the case of premixing, the viscosity increases, gelation, and precipitation occur in the raw material tank or in the middle of piping. It is difficult to mix a large amount of additives in simultaneous mixing. In the case of post-mixing, a large-scale machine is required, and there are also problems such as difficulty in uniform dispersion and the tendency to entrain a large amount of air, which tends to cause voids.

[Means for solving problems]

The present invention provides a method for easily molding a homogeneous foam in which solid raw materials such as powder and short fibers are uniformly dispersed as part of simultaneous mixing in a mixing head.

That is, the present invention is characterized in that a liquid raw material for foaming and a solid raw material are supplied onto a rotating body having protrusions of a mixer, and after uniformly dispersed and mixed, the mixture is taken out of the mixer and foamed. A foam molding method is provided.

The mixer used in the present invention may be one having a rotating body provided with protrusions that can uniformly mix the liquid raw material for foam and the solid raw material, for example, as shown in FIGS. 1 to 4. things are used.

The mixer shown in FIG. 1 includes a foam liquid raw material supply chamber 1,
It is formed by a mixing section 2, a solid raw material supply pipe 3, and the like. In the raw material supply chamber 1, each raw material component is supplied from each raw material tank at a constant N.
Using a pump etc., each annular liquid tank 11.2 is continuously pumped from the liquid raw material component port 10.20.30 at the foaming rate.
1.31, overflows from the edge 12.22.32 of the annular liquid tank, and continuously flows down the inner wall surface 13.23.33 of the annular liquid tank in the form of a thin film. Thin film formation is intended to minimize the surface area to facilitate mixing of the components and uniform dispersion of solids.

It is not necessary to use the number of annular liquid tanks according to the number of liquid raw material components; for example, the annular liquid tank can be divided into several parts using partition plates 48 as shown in FIG. It can also be used for multiple components. When providing the partition plate 48,
The number of partitions is not limited; for example, 2 to 10 partitions are possible, and 2 to 4 partitions are preferred.

Not only solid raw materials but also liquid raw materials other than foam components can be easily added through the solid raw material supply pipe 3.

As shown in FIG. 3, an injection port 51 is installed at the top or side of the raw material supply chamber 1 that can continuously supply liquid raw material components according to the blending ratio of each raw material component, without using an annular liquid tank. It is also implemented by d. Furthermore, as shown in FIG. 4, supply efficiency can be improved by using a plurality of injection ports for one component.

The quality of the product is influenced by the raw material components, especially the means of supplying the liquid raw materials, which affects the mixing state of each raw material component, uniform dispersion of solid raw materials, expansion ratio, cell size, foam curing time, etc. . Regardless of which raw material supply method is used, it is preferable to ensure that the reacting raw materials do not come into contact with each other before reaching the rotating body 41 of the mixing section 2.

The solid raw material supply pipe 3 is provided in the upper center of the raw material supply chamber 1, and a fixed amount of solid raw materials such as powder, granules or short fibers is continuously supplied to the rotating body 41 of the mixing section 2 according to the composition. Fall. A plurality of solid raw material supply pipes 3 can be provided, and by using a plurality of pipes, it is possible to easily change the type of solid raw material, and it is also possible to add a plurality of solid raw materials at the same time.

The supply section for the liquid raw material and solid raw material for foaming is preferably a closed system in order to prevent the solid raw material from spouting out or the foaming agent from evaporating and escaping.
'The mixing section 2 includes a rotating body 41 that is rotated at high speed by a motor 60, a protrusion 42 attached to the rotating body 41,
It consists of blades 44. The blades 44 are not limited to those attached to the rotary body 41, and may be discharge vanes that rotate concentrically with the rotary body 41. Scraping pieces 45 and 46 are attached to the rotating body 41 to remove the reaction mixture adhering to the walls of the mixing and stirring chamber.

When the liquid raw material for foam and the solid raw material fall into the center of the rotating body 41, since the rotating body 41 is rotating at high speed, they are mixed and agitated in a shearing manner by the centrifugal force and the protrusions 42.
When discharged by the lower blade 44, the discharge resistor is mixed with the discharge resistor and continuously discharged from the discharge port 47. The mixture, in which the solid raw materials are uniformly dispersed, is then foamed into various products using conventional molding methods. For example, a mixture is injected onto a facing material or a mold, and a facing material or mold lid is applied thereon to form a double-sided laminated panel or block. Surface materials include wood boards, plywood, decorative plywood, woven fabrics, non-woven fabrics; synthetic resin boards such as PVC and polyethylene; metal boards such as aluminum and iron; asbestos boards, gypsum boards, glass wool, craft paper, asphalt paper, etc. A wide variety of materials are used, including foam panels.

Continuous production is also possible by continuously supplying face materials and molds using a belt conveyor, etc. There is also molding in which not only the surface but also the inside of the foam is impregnated with long fibers or fiber sheets.

The molding method of the present invention is not limited to production factories;
It is also used at construction sites. Further, depending on the liquid raw material for the foam, the obtained foam may be heated to 40 to 80°C to perform post-curing.

The mixing section 2 can mix a large amount of raw materials by increasing the distance between the inner wall of the mixing and stirring chamber and the rotating body 41, and the number and location of the protrusions 42 can be adjusted as appropriate. The size of the powder and the length of lhN#m can be freely selected by In addition, since the mixing state differs depending on the properties and blending ratio of not only the solid raw materials but also the liquid raw materials, it is most preferable to change the number and arrangement of the protrusions 42, the rotation speed, and the attachment of the protrusions 43 to the wall of the mixing and stirring chamber in the mixing section 2. It is preferable to select the state.

Solid raw materials used in the invention include, for example, glass fibers, carbon fibers or other fibrous materials to increase the strength of the foam; silicic acid or metal salts of silicic acid, boric acid or metal salts of boric acid to increase fire resistance; , borofluoride compounds, metal salts of sulfuric acid, metal salts of hydrochloric acid, inorganic substances such as zinc acetate; rust inhibitors to prevent corrosion, neutralizing agents such as calcium carbonate, zinc powder, alumina powder, amine compounds, etc. Foam powders, such as lime, gypsum, cement, talc, perlite, shirasu balloons and foam wastes, are also used as fillers. The amount added is determined according to the required performance, and is generally 5 to 100% by weight based on the liquid raw material for foam, but may be limited depending on the properties of the liquid raw material and solid raw material for foam. , but is not limited to this range.

The liquid raw material for the foam used in the present invention includes liquid raw materials that are liquid in heavy water and preferably form phenol foam or urethane foam.

The liquid raw material for phenol foam is usually phenol resin,
Consists of four components: foam stabilizer, foaming agent, and curing acid. Phenolic resins can be synthesized by phenol, cresol, xylenol, trimethylphenol, p-butylphenol, p-cyclohexylphenol, p-phenylphenol, p-phenoxy in the presence of alkaline catalysts such as sodium hydroxide, barium hydroxide, ammonia or amines. It is an acid-curable resol type phenol resin obtained by condensing phenols such as phenol, p-methoxyphenol, and p-chlorophenol with aldehydes such as formaldehyde, acetaldehyde, and paraformaldehyde, and preferably contains as much free phenol water as possible. The number average molecular weight is 300-1000 and the non-volatile solid content is 7.
5 to 85%, and a viscosity (25°C) of 500 to 10,000 centivoice. The phenol resin used is not only a resol type alone but also one modified with a novolak type phenol resin or the like.

Blowing agents are compounds with low boiling points, such as low molecular weight hydrocarbons, n
-hebutane, alcohol, petroleum ether, partially or fully halogenated hydrocarbons, methylene chloride, carbon tetrachloride, trichlorofluoromethane, 1,1,2-)lichlor-1°2,2-trifluoro These compounds include ethane and the like, and these compounds can be used alone or as a mixture of two or more.

As curing acids, strong acidic compounds are preferable; for example, inorganic acids include Lewis acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc.; organic acids include sulfonic acids such as phenolsulfonic acid, benzenesulfonic acid, toluenesulfonic acid, xylene sulfonic acid, etc. These aromatic compounds can be used alone or in combination of two or more.

Foam stabilizers are added to help stabilize foam cells and are selected from condensation products of alkylene oxide and alkylphenol, polysiloxane and polyoxyalkylene copolymers, sorbitan monolaurate, polyethylated glycerin, etc. and TE0 against phenolic resin.
．． It is used in an amount of 1 to 5% by weight, and is generally mixed with a phenolic resin before foaming.

Further, liquid raw materials for urethane foam usually consist of polyisocyanate, an active hydrogen-containing compound, a blowing agent, a foam stabilizer, and a catalyst.

Polyisocyanates have at least two isocyanate groups in one molecule, such as tolylene diisocyanate, diphenylmethane diisocyanate (M
DI), xylylene diisocyanate, hexamethylene diisocyanate, polyphenylene polymethylene polyisocyanate, etc., and these can be used alone or as a mixture of two or more.

Active hydrogen-containing compounds are compounds having at least two active hydrogens in one molecule, such as polyether polyols, polyester polyols, such as propylene glycol, glycerin, trimethylolpropane, pentaerythritol, α-methyl glycoxide, sorbitol, and other polyols. Amino alcohols such as jetanolamine, triethanolamine, and tripropaturamine; amines such as ethylenediamine, 1,6-hexanediamine, diethylenetriamine, and triethylenetetramine;
Phosphorus compounds such as phosphoric acid, birophosphoric acid, or partial esters thereof, and compounds obtained by adding ethylene oxide, propylene oxide, butylene oxide, etc. to mixtures thereof are used.

The catalyst is triethylenediamine, an epoxy compound, a cocatalyst, an alkali metal salt of carboxylic acid, an alkaline earth metal salt,
Dialkylamines, alkylphenols, tertiary amines, organic tins, etc. are used.

As the foaming agent and foam stabilizer, the same ones as phenol foam are used.

Urethane foams are generally obtained by mixing a two-component system of a premix of a blowing agent, a foam stabilizer, a catalyst and an active hydrogen-containing compound with an isocyanate in a mixer according to the invention.

When producing phenol foam, phenol resin with foam stabilizer added, blowing agent, and curing acid are added to too:s~2
When producing urethane foam, the unmixed polyol and isocyanate (foam stabilizer, blowing agent, catalyst) and isocyanate are generally mixed in a weight ratio of 5:5 to 25.
It is preferable to use a weight ratio of 0.00.

Viscosity of liquid raw material for foam used in the present invention (25°C)
is usually less than 20,000 centipoise, preferably 500 centipoise
It is less than 0 centivoise.

The residence time of the raw material for foam in the mixer depends on the reactivity of the raw material,
Although it is influenced by viscosity, removal specific speed, etc., it is necessary for the mixed foam raw material to be taken out in an unfoamed state from the viewpoint of molding operations, and the residence time is generally 30 seconds or less. In addition, the rotating body of the mixer is 500~
preferably in the range of 5000 rpm, 800 to 3000
Used at a rotation speed of rpm. Incidentally, the specific speed after mixing is related to the feeding speed of the raw materials, and is not particularly limited. Of course, it largely depends on the processing capacity of the mixer, but it is generally about 25 to 500 kg/hr.

In the present invention, it is desirable that the following conditions be satisfied in order for cells to be finely filled with solid raw materials uniformly.

The supply section for the liquid raw material and solid raw material for foaming is preferably a closed system in order to prevent the solid raw material from spouting out or the blowing agent from evaporating and escaping.

In addition, since the rotating body 41 also serves to mix and discharge foam raw materials, it prevents the rotation speed from decreasing due to an extreme increase in viscosity when solid raw materials are added, and usually keeps the rotation speed at about 100 Orp.
It is better to maintain it above m. If the rotation speed decreases, the residence time in the mixer increases, foaming occurs in the mixer, and
Depending on the liquid raw material, hardening may occur, making continuous production impossible.

The discharge port 47 is used to prevent the foaming agent vaporized in the mixing section 2 from escaping, and to prevent cells from being drawn in by the discharge port.
In order to prevent the generation of voids, it is necessary to adjust the diameter of the outlet so that the outlet is as close as possible to the amount of discharge. If the diameter is too small compared to the discharge amount, a large load will be placed on the discharge by the rotary body, and the residence time in the mixer will become long, which is not preferable.

[Young Fruit of the Invention] The foam molded according to the present invention has fewer voids (and smaller cells) than conventional foams made by adding solid raw materials using a commercially available dedicated foaming machine. The solid raw material is uniformly dispersed, and each characteristic corresponding to the solid raw material can be fully exhibited.

The foam molding method of the present invention is particularly effective for uniformly filling solid raw materials during foam molding of thermosetting resin foams such as urethane foam and phenol foam.

〔Example〕

Example 1 Urethane foam was manufactured in the following manner using the mixer shown in FIG.

A mixture for hard urethane foam (Hybrox RP4020S, manufactured by Dainippon Ink & Chemicals) consisting of polyol, blowing agent, catalyst, and foam stabilizer whose temperature was adjusted to 20°C was adjusted to 20°C from the raw material injection port 20.20'. Isocyanate (Hyprosox 5P299, manufactured by Dainippon Ink and Chemicals) was fed from the raw material injection port 30.30', and pearlite was simultaneously fed from the solid raw material supply pipe 3 at a rate of 108.
kr/hr, 114 kg/hr, 31 kg/hr
Continuously supplied. Polyols and isocyanates exceed each edge 22.32 of the annular liquid tank 21.31.
Flowing down, each forming a continuous annular thin film,
At the same time, pearlite is supplied from the solid raw material supply pipe 3 and rotates at about 100 Orpm, and the protrusion 42 has a radius of 4.0 a.
The mixture is shear-mixed for about 10 seconds on rotating bodies 41, six of which are attached at equal intervals on the circumferences of m and 7.0 cm, and is continuously discharged from the discharge port 47 at a speed of 253, k.
g/hr. The mixture was taken out into a container in an unfoamed liquid state, and then foam molded at room temperature. The completed urethane foam had no voids, fine cells, and evenly dispersed pearlite, which was confirmed by X-rays.

Example 2 In FIG. 1, phenol foam was manufactured using a mixer in which the annular liquid tank 31 was divided by partition plates as shown in FIG. 2.

Phenol resin (solid content 80%, temperature adjusted to 20℃)
Viscosity 9000 cps / 20℃) and foam stabilizer (SH1
93, Toshi silicone gJJ) was added to the curing acid (
A blowing agent (Freon 11/l 13=
1/1, manufactured by Mitsui Fluorochemical Co., Ltd.] was divided into two, the other 30' of the bottom layer, and boron-based flame retardant was simultaneously supplied from the solid raw material supply pipe 3 at a rate of 38 kg/hr, 4.8
kg/hr, 8 kg/hr, 57 kg/hr
It was continuously supplied in hours. Phenolic resins, curing acids, and blowing agents each overflow to form a thin film and flow down, and at the same time, flame retardant is supplied from solid raw material supply pipe 3, and about 8
It rotates at 0 Orpm, and the projecting piece 42 has a radius of 4 with the rotating body 41.
．． The mixture is shear-mixed for about 20 seconds on rotating bodies 41, which are attached at three equal intervals on the circumferences of 0 cm and 7.0 cm, and is continuously discharged from the discharge port 47 at a speed of 56.
It was taken out at 5 kg/hr. The preparation was mixed uniformly, taken out in an unfoamed liquid state, and poured into a mold for 60 minutes.
The foam was cured in a dryer at ℃.

The finished phenol foam has fine cells and no voids, and the flame retardant is uniformly dispersed, making it compliant with JIS A-13.
It had a performance that passed the N2 grade 21 surface test.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional front view of the mixer used in the present invention, and FIG. 2 is a cross-sectional plan view taken along A-8' of the mixer shown in FIG. 1, in which the annular liquid tank 11 is divided by a partition plate 48. It is. 3 is a longitudinal sectional view of a supply section different from the supply section 2 of the mixer in FIG. 1, and FIG. 4 is a cross-sectional plan view taken along line BB' in FIG. 3. 1-----1 Liquid raw material supply chamber i for foam 2-----
-1 mixing part; 3-------Solid raw material supply pipe: 10.1
0', 20.20', 30.30' -1111 Liquid raw material inlet; 11.21.31---Annular liquid tank; 12.22.32---Annular liquid Tank edge; 13.2
3.33----Annular liquid tank inner wall surface; 41------
One rotating body; 42.43----One protruding piece i 44---
--One feather; 45.46----Scraping piece; 4'7
---------Discharge port; 48----Partition plate; 5
1-----One inlet i 60-----Motor. Agent Patent Attorney Katsutoshi Takahashi No. 10 No. 30 Illustration 2

Claims (1)

[Claims] A foam molding method characterized by supplying a liquid raw material and a solid raw material for foam onto a rotating body having protrusions of a mixer, uniformly dispersing and mixing them, and then taking the mixture out of the mixer to cause foaming.