JP4776304B2 - Resin composition for foam production, foam production method using the composition, and foam - Google Patents

Description

  The present invention relates to a resin composition for foam production containing a water-repellent fine powder having an average particle diameter of 100 nm or less as an essential component, a foam production method obtained by foaming and curing the composition, and such a production method. Relates to the resulting form. More specifically, the present invention relates to a technique for producing a phenol foam obtained by using a resol type phenol resin and an acid curing agent as essential components.

Conventionally, foams obtained by combining a synthetic resin, a foaming agent, and a curing agent, and foaming and curing include urethane foam, phenol foam, and the like. It is used in the fields of civil engineering and construction, home appliances, automobiles, etc.
In the production of these foams, chlorofluorocarbon (registered trademark) foaming agents having an ozone depletion coefficient have been used in the past. However, due to problems such as destruction of the ozone layer, they currently do not have an ozone depletion coefficient. Fluorinated hydrocarbon blowing agents such as next-generation Freon (registered trademark), hydrocarbon blowing agents, methylene chloride, carbon dioxide gas, water, and the like have been used as blowing agents. In particular, a foaming agent containing a large amount of water has been proposed due to environmental influences.
However, when foams are produced using these foaming agents, there is a problem that the produced foams are deformed or contracted when left at room temperature for a long period of time.

And as a method of solving this problem, for example, Patent Document 1 proposes a method of suppressing foam deformation by using a hydrocarbon-based blowing agent and methylene chloride in combination.
In applications where heat insulation performance is not important, it may be possible to make the foam communicate by adjusting the type and amount of the surfactant.
Furthermore, it has been proposed that a metal oxide is added to make the foam continuous in the production of urethane foam (Patent Document 2).

  However, in any of the above-described methods, the rate of foam communication increases, so that water easily enters the foam. In particular, in phenol foam, water absorption is significantly deteriorated due to this influence, and therefore, improvement in water absorption is required. When the water absorption amount of the foam is large, water with high conductivity is contained in a large amount, so that the heat insulating performance is lowered. In addition, resol type phenolic foams are cured by acid, so if foam absorbs a large amount of water, the acid in the foam will be eluted. If used as a core material for metal siding, the metal in contact with the foam will be corroded. There's a problem.

JP-A-5-163380 JP-A-5-239169

  Accordingly, the present invention has been made in view of such circumstances, and a foam manufacturing resin composition with improved foam deformation, shrinkage and water absorption, and a foam manufacturing method in which the foam manufacturing resin composition is foam-cured. And a foam obtained by the manufacturing method thereof.

  In addition, an object of the present invention is to provide a resin composition for foam production that can particularly improve the water absorption as well as the deformation and shrinkage of the foam in a phenol foam that has a property of easily absorbing water.

  As a result of intensive investigations to solve the above problems, the present inventors have found that foam deformation, shrinkage and water absorption can be improved by using a specific resin composition for foam production, and the present invention has been completed. It came to do.

  That is, the first feature of the present invention is a foam manufacturing resin composition that is foam-cured in the presence of a foaming agent, and has an average particle size of 100 nm or less together with a synthetic resin, a foaming agent, and a curing agent. A resin composition for foam production characterized by using an aqueous fine powder as an essential constituent.

Further, the second feature of the present invention is the foam as described above, wherein the water-repellent fine powder is surface-treated with a hydrophobic group having a structural formula of C _n H _{2n + 1} It is a resin composition for manufacture.

  According to a third aspect of the present invention, there is provided the resin composition for foam production as described above, wherein the synthetic resin is a resol type phenol resin and the curing agent is an acid curing agent.

  According to a fourth aspect of the present invention, there is provided a foam manufacturing method comprising foam-curing any of the above resin compositions for foam production.

  Moreover, the 5th characteristic of this invention is the foam obtained by the said manufacturing method. Specifically, it is a foam in which the above-mentioned water-repellent fine particles are dispersed in the foam. Especially, the fine pores make continuous air holes, thereby preventing deformation and shrinkage after molding, and repelling the inner cell surface of the foam. It is a foam in which water-based fine particles are exposed to thereby improve the water absorption of the foam.

  In the resin composition for foam production, the present invention uses a water-repellent fine powder having an average particle diameter of 100 nm or less as an essential component, so that when the foam is cured and cured, the heat insulation performance is not reduced. There is an effect that the evaporating property of the vaporized foaming agent is improved, and deformation, shrinkage and water absorption after foam production can be improved.

Phenol Lumpur foams resin composition is roughly divided into a novolak phenolic foams resin composition and a resol-type phenolic foams resin composition, as a component of the novolak phenolic foams resin composition, a novolac Type phenolic resin, curing agent, foaming agent and other additive components used as necessary, and the constituents of the resin composition for producing a resol type phenol foam include a resol type phenolic resin, an acid curing agent, a foaming agent, Examples thereof include foam stabilizers and other additive components used as necessary.

The phenol Lumpur resin, benzyl ether-type phenolic resins, modified benzyl ether-type phenolic resin obtained by reacting or mixing any modifying compound in the resin is preferable. Examples of modifying compounds include alkylene oxides, cyclic carbonates (eg, ethylene carbonate, propylene carbonate, etc.), epoxy compounds such as epoxy resins, nitrogen-containing compounds such as urea resins, melamine resins, and polyamide resins, xylene resins, and the like. Is mentioned. Further, in some cases, it is obtained by applying a resol type phenol resin, a novolac type phenol resin, a phenol resin in which a methylol group or a dimethylene ether group is introduced into a novolac type phenol resin, and treatment of these resins with the modifying compound. A modified phenolic resin can be used alone or in combination with the benzyl ether type phenolic resin.

  The resol-type phenol resin, which is a constituent of the resin composition for producing the resole-type phenol foam, advantageously uses aldehydes in a ratio of about 1.0 to 2.5 mol with respect to 1 mol of phenols. , They are reacted in the presence of an alkaline reaction catalyst, for example, at a temperature in the range of 50 ° C. to reflux temperature, followed by neutralization treatment, and then under reduced pressure at a predetermined characteristic value, for example, 25 ° C. Dehydration and concentration are performed so that the viscosity is 10 Pa · s or less, preferably 5 Pa · s or less, and the water content is 3 to 20%, preferably 5 to 15%. Accordingly, predetermined additives are added in the same manner as in the prior art, and they are manufactured. Of course, in addition to such a resol type phenolic resin, various known resol type phenolic resins that can be cured with an acid curing agent can be appropriately employed, and suitable modifiers can also be used. The resol type phenol resin modified by the above can also be used in the same manner.

  The phenols that are one of the raw materials of the resol type phenol resin used in the method of the present invention include phenol, o-cresol, m-cresol, p-cresol, p-tert-butylphenol, m-xylenol, and bisphenol F. And bisphenol A. Examples of aldehydes that are the other raw materials used in combination with the phenols include formaldehyde, paraformaldehyde, trioxane, polyoxymethylene, glyoxal and the like. Furthermore, examples of the reaction catalyst include potassium hydroxide, sodium hydroxide, barium hydroxide, calcium hydroxide, potassium carbonate, ammonia and the like. Of course, these phenols, aldehydes and reaction catalysts are not limited to the above examples, and various known ones can be used as appropriate. It can be used alone or in combination of two or more.

  The acid curing agent, which is a constituent component of the resin composition for producing the resol type phenol foam, is a component (curing catalyst) for accelerating the curing reaction of the resol type phenol resin as described above. The acid curing agent is appropriately selected and used. Examples of the acid curing agent include aromatic sulfonic acids such as benzenesulfonic acid, phenolsulfonic acid, cresolsulfonic acid, toluenesulfonic acid, xylenesulfonic acid, and naphthalenesulfonic acid; methanesulfonic acid, trifluoromethanesulfonic acid Aliphatic sulfonic acids such as sulfuric acid, phosphoric acid, polyphosphoric acid, inorganic acids such as borohydrofluoric acid, and the like. These may be used alone or in combination of two or more. However, there is no problem. Among these exemplified acid curing agents, phenol sulfonic acid, toluene sulfonic acid, naphthalene sulfonic acid, in the production of phenol foam, from the point of achieving an appropriate curing speed, The balance with foaming by the foaming agent is further improved, and it is particularly preferably used.

  Further, the amount of the acid curing agent used is appropriately set according to the type and temperature conditions at the time of mixing with the resol type phenol resin, but in the present invention, the resol type phenol resin is used. It is generally 1-50 parts by weight, preferably 10-30 parts by weight per 100 parts by weight. With such a blending amount, the curing reaction preferably proceeds and the intended phenol foam is easily obtained.

  Furthermore, the acid curing agents exemplified above are solid or liquid at room temperature, and they are blended and mixed as they are with respect to the resol type phenol resin, specifically, with respect to the above described resol type phenol resin. In general, in order to further improve the mixing property with the resol type phenol resin, it is dissolved in a water-based medium so as to have a concentration of about 50 to 80% by weight. Will be used in the state. In addition, since the aqueous solution of such an acid curing agent is used in a relatively small amount, it is generally used for mixing with the above-described resol type phenol resin without being heated. Similarly to the resol type phenolic resin, it is possible to use it after heating (temperature adjustment) to a predetermined temperature.

  The foaming agent that is a constituent of the resin composition for producing the resol type phenol foam usually has 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1, Fluorinated hydrocarbon foams such as 3,3-pentafluorobutane (HFC-365mfc), 1,1,1,2-tetrafluoroethane (HFC-134a), trifluoroethane, perfluorohexane, perfluoropentane, etc. Lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, calcium carbonate and magnesium carbonate that generate carbon dioxide gas by reaction with an agent, hydrocarbon foaming agents such as normal pentane, cyclopentane, and normal hexane, and acid curing agents Carbonates such as sodium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, etc. Chloride, water, and combinations thereof are used, but if necessary, aliphatic ethers such as diethyl ether and diisopropyl ether, paratoluenesulfonyl hydrazide, oxybisbenzenesulfonyl hydrazide, azobisisobutyronitrile, etc. Pyrolytic foaming agents, gas bodies such as air, nitrogen, carbon dioxide and butane are also used. The amount of the foaming agent used varies depending on the foam density, the type of foaming agent, etc., but is generally selected in the range of 0.5 to 50 parts by weight per 100 parts by weight of the resol type phenol resin.

  In addition, as the foam stabilizer, which is a component of the resin composition for producing a resol type phenol foam, any of various foam stabilizers conventionally used in the technical field is selectively used. However, among these, nonionic surfactants such as castor oil ethylene oxide adduct, polysiloxane, polyoxyethylene sorbitan fatty acid ester, and alkylphenol ethylene oxide adduct are particularly preferably used. These foam stabilizers can be used alone or in combination of two or more thereof, and the amount used is not particularly limited, but in general, a resol type phenol resin. It will be used within the range of 0.5 to 10 parts by weight with respect to 100 parts by weight.

  In addition, the resin composition for producing the resol-type phenol foam may include other known additives such as a viscosity reducer, a formalin catcher agent, a filler, a reinforcing material, a flame retardant, etc. as desired. It can be appropriately selected and used so as to obtain a known composition that easily causes a structure.

Range of the density of the phenolic foam is from about 8~40kg / ^{m 3} is typically used many among them high-density products 35~40kg / ^{m 3.} The present invention is not limited, in particular about 8~20kg / ^{m 3,} more is preferably applied by the case of a low density foam of about 8~16kg / ^{m 3.} This is because if the foam has a low density, the cell thickness of the resin is thin and the number of communication holes must be increased, and the problems of deformation, compression, and water absorption become more serious. In order to reduce the density of the foam, there are methods such as increasing the amount of foaming agent added, adding a heat-generating substance, or adding heat from the outside.

And in this invention, it has a big feature in using the water-repellent fine powder with an average particle diameter of 100 nm or less contained as an essential component in the resin composition for foam production. Yes. By using such a specific water-repellent fine powder, when foaming resin composition for foam production is foamed and cured, it is possible to remove the vaporized foaming agent without reducing the heat insulation performance by connecting the foam. In addition to improving deformation and improving deformation and shrinkage after foam production, water-repellent fine particles are dispersed and present on the surface of the internal pores of the foam in which communication holes are formed, making the foam interior water-repellent and water absorption of the foam The property can be remarkably improved. By improving the water absorption, the heat insulating performance of the foam is improved, and it is possible to prevent the metal in contact with the foam from being corroded.
The water-repellent fine powder is not particularly limited as long as it has water repellency, but the surface of fine particles of silica, alumina, zinc oxide, titanium dioxide, iron oxide, magnesia, etc. is treated with water repellency (providing hydrophobicity). Processed) is preferred. Among these, in consideration of dispersibility in a solution and the like, a non-metal having a low specific gravity is preferable, and a silica-based one is particularly preferable. If the dispersibility is poor, the water-repellent fine powder is difficult to be uniformly dispersed in the foam, and it is difficult to obtain the effects of the present invention such as suppressing the shrinkage of the foam.

  Here, the average particle diameter of the water-repellent fine powder needs to be 100 nm or less, preferably 50 nm or less, and most preferably 30 nm or less. When the average particle diameter of the water-repellent fine powder exceeds 100 nm, the number of particles per unit weight is reduced, and formation of communication holes and imparting water repellency to the inner surface of the foam cannot be obtained sufficiently. Moreover, when such large particles are blended in a large amount with respect to the synthetic resin, since the particles are large, the film of bubbles in the foam is excessively broken, and weakening of the strength of the foam is caused. The lower limit of the average particle diameter of the water-repellent fine powder is not particularly limited, but it is difficult to obtain a very small one, and problems such as easy aggregation and difficult uniform dispersion are also considered, and it is generally 1 nm or more.

The water-repellent fine powder used in the present invention preferably has a physical or chemical treatment and is given water repellency (hydrophobicity). Among them, a structural formula of C _n H _{2n + 1} such as methyl group and ethyl group Having at least one alkyl group represented by the structural formula of C _n H _{2n + 1 in} a part of the structure, such as an alkyl group represented by the following formula: trimethylsilyl group, dimethyl silicone oil, etc. (hydrophilic groups such as hydroxyl groups are It is particularly preferred that the surface treatment of the fine powder is carried out physically or chemically, as much as possible and should not contain any hydrophilic groups. In the above formula, the number of n is not particularly limited and can be appropriately selected as a design matter of those skilled in the art. However, in view of availability, it is usually 1 to 20, preferably 1. -10, most preferably 1-8. Such fine particles obtained by subjecting the surface to water repellency (hydrophobicity) can be obtained, for example, from Nippon Aerosil Co., Ltd.
The evaluation of water repellency is not particularly limited, but when the treatment for imparting a hydrocarbon-based hydrophobic group is performed as described above, it is easy to evaluate by the carbon content. Although depending on the size and density of the fine particles, generally, the carbon content is preferably 0.5% by weight or more of the fine particles, more preferably 0.7% by weight or more, and further preferably 0.9% by weight or more. It is. When the metal oxide is not surface-treated, the carbon content is a value close to 0% by weight. The carbon content can be measured, for example, using a carbon analyzer (EMIA-110 type) manufactured by Horiba, Ltd.

  Moreover, it is preferable that the said water-repellent fine powder is used in the ratio of 0.01-10 weight part with respect to 100 weight part of resin compositions for foam manufacture. If the amount added to the resin composition for foam production is less than 0.01 parts by weight, the foam shrinkage, deformation, water absorption may not be expected, and if the amount exceeds 10 parts by weight This is because there is a possibility that problems such as a decrease in heat insulation performance may occur due to an excessive increase in the rate of foam communication.

  In the present invention, the above-mentioned resin composition for foam production is mixed to form the desired foam. At that time, the mixing is performed using various known stirrers. Or using a mixer.

  The foam produced according to the present invention can be advantageously used for various conventionally known applications. For example, it can be used as a heat insulating material, or can be used as a metal siding, wall, roof, ceiling, floor, etc. It can be advantageously used for applications such as a base material.

  Hereinafter, the present invention will be more specifically clarified by using some examples, but it should be understood that the present invention is not construed as being limited in any way by the description of such examples. It should be. In addition to the following examples, the present invention includes various changes, modifications, and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, in addition to the specific techniques described above. It should be understood that improvements and the like can be added.

In the following Examples and Comparative Examples, the obtained resin composition for foam production and various physical properties of the foam were respectively measured by the following test methods.
(1) The viscosity of the polyol and the resol type phenol resin was measured in accordance with JIS-K-7233 at a temperature [viscosity (Pa · s (pascal · second)) at 25 ° C.].
(2) The water content [% by weight] of the resol-type phenolic resin is obtained by sufficiently dissolving 0.2 g of resin in a dehydrating solvent [Mitsubishi Kasei Kogyo Co., Ltd., chloroform / methanol mixed solvent] Titration with a Hydranal composite made by company] and measurement. In addition, the water | moisture content automatic measuring apparatus [The Hiranuma Sangyo Co., Ltd. make and AQV-5S] was used for this titration.
(3) The density of the foam was measured according to JIS-A-9511.
(4) The shrinkage of the foam is the foam produced by cup foaming in the following examples and comparative examples, brought close to the end of the cup, and measured the distance from the end of the cup opposite to the approached side to the foam, The following three-stage evaluation was performed according to the length of the distance.
○: Less than 10 mm, Δ: 10 mm or more and less than 30 mm, x: 30 mm or more (5) The water absorption amount of the foam was measured according to JIS-A-9511.
(6) The thermal conductivity of the foam was measured according to JIS-A-1412.
(7) The uniformity of the foam cells was evaluated by the following three-stage evaluation.
○: Uniformity, Δ: Slightly nonuniform, ×: Remarkably nonuniform [Example 1]

(1) By reacting 1.4 mol of paraformaldehyde in the presence of NaOH catalyst with respect to 1 mol of adjusted phenol of component liquid 1 containing resol type phenol resin as an essential component of a resin composition for phenol foam production Addition of water: 1.2 kg, 50% urea water: 2.6 kg, castor oil-based ethylene oxide to 100 kg of the obtained resol type phenolic resin having a viscosity of 1.7 Pa · s / 25 ° C. and a water content of 8.3 wt% Product: 3 kg, calcium carbonate: 3.5 kg, silicone oil: 1 kg, fine powder made water-repellent by surface treatment with alkyl group [trade name: AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd., carbon content of about 1% by weight] : What added 0.5 kg was obtained as the component liquid 1.

(2) A phenolsulfonic acid was used as the adjustment acid curing agent of component liquid 2 containing the acid curing agent of the resin composition for phenol foam production as an essential component, and an aqueous solution having a concentration of 62% by weight was prepared as component liquid 2. .

(3) Production of phenol foam 111.8 g of component liquid 1 obtained above was weighed into a 500 ml polypropylene disc cup, and 21 g of component liquid 2 was weighed into a 100 ml polypropylene disc cup. The temperature was adjusted to 55 ° C., component liquid 2 was put into a 500 ml polypropylene disc cup containing component liquid 1, and T.V. K. By stirring and mixing the component liquid 1 and the component liquid 2 for 3 seconds using a homodisper, they were foamed and cured to obtain a phenol foam. And the density of foam, shrinkage | contraction of foam, and the uniformity of the cell of foam were confirmed from the obtained phenol foam.

Moreover, after changing the quantity of said component liquid 1 and component liquid 2 to 201.2g and 37.8g, respectively, and measuring to a cup, both were temperature-controlled at the temperature of 45 degreeC, and component liquid 2 was made into component Into a 500 ml polypropylene disc cup containing liquid 1, K. The component liquid 1 and the component liquid 2 are stirred and mixed for 2 seconds using a homodisper, and the mixed liquid is poured into a 30 cm × 30 cm × 10 cm aluminum mold that has been temperature-controlled in advance at 90 ° C. to foam and harden the panel. A phenolic foam was obtained. And from the obtained phenol foam, the thermal conductivity of the foam and the water absorption of the foam were confirmed. The results obtained by the above series of operations are shown in Table 1 below.
[Examples 2 to 4 ]

As shown in Table 1 below, fine water-repellent fine powder AEROSIL R202 (appearance specific gravity about 50 g / l, carbon content about 5% by weight) made surface-treated with dimethyl silicone oil. , Fine powder AEROSIL R805 (apparent specific gravity of about 50 g / l, carbon content of about 5 to 7% by weight) surface-treated with octylsilane, water-repellent titanium dioxide surface-treated with octylsilane fine powder T805 (apparent specific gravity of about 200 g / l, about 2.7 to 3.7 wt% carbon content) [all Nippon Aerosil Co., Ltd.], except to change, the same operation as in example 1 Then, a phenol foam was prepared and the physical properties were measured. The obtained results are shown in Table 1 below.
[Comparative Example 1 ]

A phenol foam was prepared and the physical properties were measured in the same manner as in Example 1 except that the water-repellent fine powder was not changed. The obtained results are shown in Table 1 below.
[Comparative Example 2 ]

Except for changing the water-repellent fine powder to a hydrophilic fine powder [trade name: Microsilica, manufactured by Elchem Japan Co., Ltd.], the same procedure as in Example 1 was performed to prepare a phenol foam, and the physical properties were changed. It was measured. The obtained results are shown in Table 1 below.
[Comparative Example 3 ]

Except for changing the water-repellent fine powder to a hydrophilic fine powder [trade name: AEROSIL 200, manufactured by Nippon Aerosil Co., Ltd.], the same procedure as in Example 1 was performed to prepare a phenol foam, and the physical properties were measured. . The obtained results are shown in Table 1 below.
[Comparative Example 4 ]

A phenol foam was produced in the same manner as in Example 1 except that the water-repellent fine powder was changed to a metal oxide [trade name: NanoTek CeO ₂ manufactured by C-I Kasei Co., Ltd.], and physical properties were measured. The obtained results are shown in Table 1 below.

As is clear from the results of Table 1 , in the case of Examples 1 to 4 containing water-repellent fine powder according to the present invention, the cell uniformity was good and the thermal conductivity was maintained. It can be seen that the shrinkage of the foam is suppressed and that the water absorption is particularly improved. For the phenol foam of low density (12~14kg / m ³⁾ as shown in Comparative Examples 1 to 4 in Table 1, the water absorption as high as 12 g / 100 cm ² or more, is a practical problem, Examples 1-4 It is recognized that the water absorption is remarkably improved.

On the other hand, in the case of Comparative Example 1 in which the water-repellent fine powder is not contained and Comparative Example 2 containing particles having an average particle diameter larger than 100 nm, the shrinkage of the foam is large and the water absorption amount is also large. The foam has poor foam properties. Moreover, even in the case of Comparative Examples 3 to 4 containing a hydrophilic fine powder or a metal oxide, although the shrinkage is suppressed, the water absorption is greatly inferior to that of Examples 1 to 4 , The foam is still inferior in foam properties.

Claims (3)

A resole-type phenol resin composition for foam production which is foam-cured in the presence of a foaming agent, and comprises a water-repellent fine powder having an average particle diameter of 100 nm or less together with a synthetic resin, a foaming agent and an acid curing agent. Resol-type phenolic resin composition for foam production, characterized in that the water-repellent fine powder is a fine particle which is surface-treated with a hydrophobic group having a structural formula of C _n H _{2n + 1.} object. A foam production method comprising foam-curing the resol type phenolic resin composition for foam production according to claim 1 . A foam obtained by the production method according to claim 2 .