JP2001088158A - Production of composite foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of producing composite foam consisting of a curable foamable compsn. and foamable thermoplastic resin beads in a wide range of a compounding ratio and excellent in workability. SOLUTION: In producing foam consisting of a curable foamable compsn. and foamable thermoplastic resin beads, a discharge port of the curable foamable compsn. and discharge port of the foamable thermoplastic resin beads independent thereof are used to form composite foam consisting of the curable foamable compsn. and the foamable thermoplastic resin beads.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite foam comprising a curable foamable composition and foamable thermoplastic resin beads, and the obtained foam is a heat insulating material, a sealing material, a waterproofing agent, a buffer, and the like. It is suitable for materials.

[0002]

2. Description of the Related Art Today, foamed plastics are widely used as heat insulating materials, sealing materials, water blocking agents, cushioning materials, and the like, and include phenolic resins, polyvinyl chloride, and three types of foams such as polyurethane, polystyrene, and polyolefin.
Various foams are provided according to applications such as polyurea resin and silicone.

[0003] Among them, the development of hybrid materials combining two or more types of foamed plastics has been advanced for a long time, and several technologies have been published as patents. For example, Japanese Patent Application Laid-Open No. 48-77957 discloses a seat lining material characterized in that expandable polystyrene particles are foamed by utilizing reaction heat in a urethane foam production process, and urethane foam and expanded polystyrene particles are integrally formed. In addition to the production method, Japanese Patent Publication No. 47-258
No. 55 discloses a method for producing a hybrid foam in which particles of a crosslinked styrene polymer thermally expanded by heat of urethane reaction are dispersed in a flexible polyurethane matrix. Japanese Patent Application Laid-Open No. 5-200889 discloses a foamed cushion in which primary foamed polystyrene beads are bonded and solidified with a water-foamable urethane-based adhesive.

[0004] However, there has not yet been proposed an excellent concrete means which can be implemented industrially when producing a foam comprising such a curable foamable composition and foamable thermoplastic resin beads. If such a foam is to be produced, a method of previously mixing unfoamed or foamed foamable thermoplastic resin beads with the curable foamable composition, that is, when the curable foamable composition is a two-part composition, One possible method is to mix foaming thermoplastic resin beads in one or both, and then mix the two liquids during molding.

[0005] However, when two liquids are mixed at the time of molding as described above, quantitative mixing of the two greatly affects the physical properties of the finally obtained foam. It is necessary to uniformly disperse the thermoplastic resin beads. For this purpose, it is necessary to control the difference in specific gravity and compatibility between the two. In addition, a component that dissolves foamable thermoplastic resin beads cannot be used as the curable foamable composition, and there is also a problem that the fluidity is reduced by blending the foamable thermoplastic resin beads into the curable foamable composition. In addition, many restrictions are also imposed on variously setting the mixing ratio of the curable foamable composition and the foamable thermoplastic resin beads.

[0006] The foamable thermoplastic resin beads having a small particle diameter of, for example, 100 µm or less are relatively easy to handle, but are often large beads having a particle diameter of 100 µm or more. In such a case, clogging in the device is likely to occur.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a composite foam comprising a curable foamable composition and a foamable thermoplastic resin bead which avoids the above problems and enables a wide range of compounding designs. And to provide a manufacturing method excellent in workability.

[0008]

That is, the present invention provides the following methods (1) to (5) for producing a foam comprising a curable foamable composition and foamable thermoplastic resin beads. Things. (1) The curable foamable composition and the foamable thermoplastic resin beads are discharged from each of the discharge ports of the curable foamable composition and the foamable thermoplastic resin beads by using an independent outlet of the foamable thermoplastic resin beads. A method for producing a composite foam, comprising: discharging a composite foam comprising a curable foamable composition and a foamable thermoplastic resin bead; (2) a discharge port for the curable foamable composition; The composite foam according to (1), wherein the curable foamable composition and the foamable thermoplastic resin beads are discharged by a discharge device in which discharge ports for foamable thermoplastic resin beads which are independent of the above are arranged close to each other. Production method. (3) The method for producing a composite foam according to (1) or (2), wherein the composite foam comprising the curable foamable composition and the foamable thermoplastic resin beads is applied to injection molding or spray coating. (4) A curable foamable composition comprising: A) a compound having an average of more than one hydroxyl group per molecule, a compound having an average of more than one isocyanate group per molecule, and a curing catalyst. And / or B) a composition comprising a compound having an average of more than one hydrosilyl-reactive unsaturated bond per molecule, a compound having an average of more than one hydrosilyl group per molecule, and a curing catalyst. The method for producing a composite foam according to any one of (1) to (3), comprising: (5) The method for producing a composite foam according to any one of (1) to (4), wherein the curable foamable composition uses water as a foaming agent. (6) The expandable thermoplastic resin beads are at least one selected from the group consisting of a polystyrene resin impregnated with a foaming agent, a polyethylene resin impregnated with a foaming agent, and a polypropylene resin impregnated with a foaming agent. 5) The method for producing a composite foam according to any one of 5).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The curable foamable composition according to the present invention is a composition capable of forming a foam having a crosslinked structure, and has a sufficient amount of heat for foaming the foamable thermoplastic resin beads. Specific examples include: A) a composition comprising a compound having an average of more than one hydroxyl group per molecule, a compound having an average of more than one isocyanate group per molecule, and a curing catalyst; And B) a composition comprising a compound having an average of more than one hydrosilyl-reactive unsaturated bond per molecule, a compound having an average of more than one hydrosilyl group per molecule, and a curing catalyst. .

Among them, A) is a composition for forming a foam generally called urethane foam or nullate foam. Usually, a reaction between a polyol compound having a plurality of hydroxyl groups and a polyisocyanate compound having an isocyanate group, or a reaction between polyisocyanate compounds serves as a base for resin formation, and an organic compound such as chlorofluorocarbon or pentane is compounded as a foaming agent. This forms a foam. In addition, so-called water-foamed urethane which utilizes carbon dioxide generated by the reaction between water and isocyanate groups as a foaming agent is also included in the composition A) as a non-fluorocarbon type.

The average number of molecules used per molecule is 1
The compound having more than one hydroxyl group is not particularly limited as long as it is a generally used polyol, and examples thereof include polyol compounds for urethane raw materials such as polyester polyols and polyether polyols. These can be used alone or as a mixture of two or more.

Compounds having more than one isocyanate group on average per molecule include phenylmethane diisocyanate (hereinafter abbreviated as MDI) and polyphenylmethane polyisocyanate (hereinafter abbreviated as Polymeric MD).
I), tolylene diisocyanate (hereinafter abbreviated as TDI), a mixture thereof, hexamethylene diisocyanate, isophorone isocyanate, and generally known organic isocyanate compounds for urethane raw materials.

Examples of the curing catalyst include generally known catalysts for urethane raw materials such as amine compounds, organic tin compounds, organic metal salts, and alkali metal hydroxides. Since the activities for urethanation, ureaization and isocyanuration are different from each other, a plurality of these are often used in combination according to the purpose.

The foaming agent is not particularly limited, but includes generally used organic compounds such as a CFC compound and pentane, and water. Among them, water is preferable from the viewpoint of environmental load.

Further, in order to control various physical properties of the foam,
In addition, foam stabilizers and flame retardants are generally used.

B) is typified by silicone foam and the like. The reaction between an unsaturated bond capable of hydrosilylation reaction and a hydrosilyl group serves as a base for forming a resin. The blowing agent will cause foaming. Further, this system also includes water foaming utilizing hydrogen generated by the reaction between water and a hydrosilyl group.

The compound having an average of one or more hydrosilylation-reactive unsaturated bonds per molecule is not particularly limited as long as it has a carbon-carbon unsaturated bond in the molecule. Considering the reactivity, those having the unsaturated bond at the molecular terminal or side chain are preferred. In this case, the main chain skeleton is not particularly limited, and includes various oligomers or polymers such as silicone, polyether, polyester, and hydrocarbon polymer. Further, low molecular weight compounds having various allyl groups, vinyl groups and the like can also be used. However, there are many factors that inhibit the hydrosilylation reaction, and the use thereof must be sufficiently considered from the viewpoint of reactivity.

The compound having an average of more than one hydrosilyl group per molecule is not particularly limited as long as it has a hydrosilyl group in the molecule. Polysiloxanes, cyclic polysiloxanes, polysiloxanes in which some of these hydrosilyl groups are modified with an organic functional group, and low-molecular-weight organosilicon compounds having a hydrosilyl group in the molecule.

The curing catalyst is not particularly limited as long as it has activity in the hydrosilylation reaction, and a transition metal catalyst such as a platinum compound or a rhodium compound is generally used.

The foaming agent is not particularly limited, but includes generally used organic compounds such as a fluorocarbon compound and pentane, alcohols such as ethanol, propanol and butanol, and water. Among them, the latter compound having active hydrogen reacts with the above-mentioned hydrosilyl group to generate hydrogen, which acts as a foaming agent.

As the curable foamable composition of the present invention, at least one of A) and B) may be used, and a plurality of compositions may be used.

On the other hand, the expandable thermoplastic resin beads of the present invention are those which can be expanded by heat generated by the reaction of the curable expandable composition, and specifically, a polystyrene-based beads impregnated with a blowing agent. It is at least one selected from a resin, a polyethylene resin impregnated with a foaming agent, and a polypropylene resin impregnated with a foaming agent.

The foaming agent to be impregnated in these foamable thermoplastic resin beads does not adversely affect the natural environment unlike the CFC compound, and has a boiling point of -20 to +12.
Organic compounds at about 0 ° C. are preferred. Examples of such a blowing agent include hydrocarbons having 3 to 6 carbon atoms, and specifically, propane, butane, n-pentane, i-pentane,
And cyclopentane.

Such foamable thermoplastic resin beads are:
Although it can be foamed by the heat generated by the reaction of the curable foamable composition, a small amount of a crosslinkable monomer is added to the foamable thermoplastic resin for the purpose of avoiding shrinkage of the foamed beads due to excessive heat. You may add at the time of manufacture of a bead.

The method for producing the composite foam of the present invention, ie, the composite foam comprising the curable foamable composition and the foamable thermoplastic resin beads, comprises a discharge port for the curable foamable composition, and an independent outlet. Using the discharge port of the expandable thermoplastic resin beads, the curable foamable composition and the expandable thermoplastic resin beads are discharged from the respective discharge ports, and the curable foamable composition and the expandable thermoplastic resin beads are discharged from the discharge ports. Characterized in that a composite foam is produced.

Specifically, in addition to a metering discharge device having a discharge port for discharging the curable foamable composition, a discharge device for a solid having a discharge port for discharging foamable thermoplastic resin beads is prepared. By discharging both components from the respective discharge ports, individual reactions of the two components are caused in the mold or on the adherend to obtain a composite foam. Specific examples of the former device having a discharge port for discharging the curable foamable composition include one liquid or two liquids developed for urethane, polyester, epoxy, and silicone.
A liquid metering / mixing / discharging device and a spraying device such as urethane and polyester are exemplified. Further, as the device having a discharge port for discharging the foamable thermoplastic resin beads of the latter,
There is no particular limitation as long as beads and powder can be transferred and discharged stably, but a powder coating machine or the like is a preferred specific example from the viewpoint of quantitative discharge.

There is no particular limitation on the combination of these two components, and it is important that both components are independently discharged from each discharge port. Both may be mixed on the body. That is, in actual molding or construction, both devices may be used independently, or the devices may be integrated and used in conjunction with each other. In order to secure stable workability, it is preferable to perform discharge using a discharge device in which individual discharge ports are arranged close to each other. More specifically, the nozzle or spray gun of the powder coating machine or the like is fixed to the nozzle or spray gun of the two-liquid metering mixing / dispensing device or spray device with a simple jig, and integrated. And other methods.

As described above, since the curable foaming composition and the foaming thermoplastic resin beads are independently discharged from the individual discharge ports, it is possible to avoid various restrictions caused by the solid / liquid mixture. A wide range of material design is possible. Further, in the present invention, the mixing ratio of the curable foamable composition and the foamable thermoplastic resin beads can be widely controlled by the ejection amount or ejection pattern of the beads.

As described above, a composite foam can be easily obtained without requiring special and expensive equipment. The method for producing a composite foam of the present invention is suitable for spray coating for building insulation (so-called in-situ foaming), injection molding of sandwich panels, metal siding, laminate boards, etc., and injection molding of heat insulation equipment such as refrigerators. It is.

Hereinafter, the method for producing the composite foam of the present invention will be described with reference to examples.

[0031]

EXAMPLE A urethane stock solution A and a urethane stock solution B were spray-coated by Binks' urethane mixed spray device model formulator "L", and a Wagner manual powder system "Integral 2020 Air Fluid" (the spray gun was "PEM"). -C1 ″) was used to spray expandable polystyrene beads to produce a foam.

The urethane stock solution A includes Polymeric M
DI (polymethylene polyphenyl polyisocyanate)
It was used. On the other hand, 75 parts by weight of sorbitol-based polyol, 25 parts by weight of ethylenediamine-based polyol, 30 parts by weight of tris (chloropropyl) phosphate as a flame retardant, 4.5 parts by weight of ion-exchanged water as a foaming agent, 1.5 parts by weight of Nippon Unicar Co., Ltd. L-5420 as a foam stabilizer, 8.3 parts by weight of Tosoh Corporation TEDA-L33 as a catalyst, TOYOC
2.4 parts by weight of AT-TRC could be mixed.

On the other hand, as expandable polystyrene beads, Kanepal SKM manufactured by Kaneka Chemical Industry Co., Ltd. (particle diameter: about 1 m)
m) was used.

The urethane stock solution A and the urethane stock solution B were each spray-coated at a discharge pressure of 6.9 MPa, and at the same time, the expandable polystyrene beads were sprayed at 0.4 MPa.
It sprayed by the air pressure of a. At the time of spraying, both spray guns were arbitrarily operated, and care was taken so that they could be mixed and applied onto the test plate.

The discharge rates of the urethane and the expandable polystyrene beads are about 600 g / min, respectively, and the mixing ratio is 1:
It was one.

In the obtained foam, it was confirmed that the expanded polystyrene was almost uniformly dispersed in the urethane foam.

[0037]

Comparative Example In the urethane stock solution B used in the examples,
Foamable polystyrene beads (Kanepal SKM, manufactured by Kaneka Chemical Industry Co., Ltd.) were mixed at a ratio of 50 wt%, and the liquid sending was tested using Binks urethane mixing sprayer model formulator "L".

As a result, the cylinder pump pressure was reduced to 12MP.
Even when the pressure was increased to a, the device stopped due to clogging in the cylinder. Further, the dispersion of the expandable polystyrene beads in the urethane stock solution B was not uniform, and mixing with a stirrer was necessary to make the dispersion uniform.

[0039]

As described above, according to the present invention, a composite foam comprising a curable foamable composition and a foamable thermoplastic resin bead is discharged by independently discharging both discharge ports. It can be easily manufactured in a wide mixing ratio without using special equipment, and is suitable for injection molding and spray coating.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 9/35 CEZ C08L 23/04 4J035 C08L 23/04 25/06 25/06 (C08G 18/48 // (C08G 18/48 101: 00) 101: 00) B29K 23:00 B29K 23:00 25:00 25:00 75:00 75:00 105: 04 105: 04 B29C 67/22 F term (reference) 4F074 AA17 AA24 AA32 AA79 AA91 AA95 BA34 BA35 BB23 CA22 CA34 DA32. DG00 HA01 HA02 HA07 HA09 HC03 HC12 HC17 HC22 HC46 HC52 HC61 HC63 HC64 HC67 HC71 HC73 KA01 KB05 KC17 KD12 KE02 NA02 NA03 NA06 QC01 RA15 4J035 BA02 CA021 CA141 FB05 LA04 LB20

Claims (6)

[Claims] 1. A curable foamable composition and a foamable thermoplastic resin bead are respectively discharged using a discharge port of the curable foamable composition and a discharge port of a foamable thermoplastic resin bead which is independent of the discharge port. A method for producing a composite foam, comprising: discharging from an outlet to form a composite foam comprising a curable foamable composition and foamable thermoplastic resin beads. 2. A curable foamable composition and a foamable thermoplastic resin bead are provided by a discharge device in which a discharge port of the curable foamable composition and a discharge port of a foamable thermoplastic resin bead which are independent from each other are arranged in proximity to each other. 2. The method for producing a composite foam according to claim 1, wherein the composite foam is discharged. 3. The method for producing a composite foam according to claim 1, wherein the composite foam comprising the curable foamable composition and the foamable thermoplastic resin beads is applied to injection molding or spray coating. 4. A curable foamable composition comprising: A) a compound having an average of more than one hydroxyl group per molecule, a compound having an average of more than one isocyanate group per molecule, and a curing catalyst. And / or B) a composition comprising a compound having an average of more than one hydrosilylation-reactive unsaturated bond per molecule, a compound having an average of more than one hydrosilyl group per molecule, and a curing catalyst. The method for producing a composite foam according to any one of claims 1 to 3, comprising a product. 5. The method for producing a composite foam according to claim 1, wherein the curable foamable composition uses water as a foaming agent. 6. The foamable thermoplastic resin beads are at least one selected from a polystyrene resin impregnated with a foaming agent, a polyethylene resin impregnated with a foaming agent, and a polypropylene resin impregnated with a foaming agent. A method for producing a composite foam according to any one of claims 1 to 5.