JP6769426B2 - Binder composition for mineral wool, manufacturing method of mineral wool and mineral wool - Google Patents

Description

The present invention relates to a binder composition for mineral wool, mineral wool and a method for producing mineral wool.

In mineral wool such as glass wool or rock wool, a binder (binder for mineral wool) is used to bond the fibers.

Conventionally, a binder containing a phenol resin as a main component has been used for mineral wool. In recent years, due to health concerns about formaldehyde emitted from phenolic resin, polyvinyl alcohol resin may be used as the binder instead of phenolic resin. For example, Patent Document 1 describes an inorganic substance obtained by mixing a water-soluble polymer containing a polyvinyl alcohol-based resin as a main component, a cross-linking agent, an adhesion inhibitor, a silane coupling agent, and a mold release agent. A water-soluble binder for inorganic fibers, which is a water-soluble binder for fibers and is characterized in that the cured product has excellent elasticity and water resistance, is disclosed.

Japanese Unexamined Patent Publication No. 2016-108707

The present inventors may find that mineral wool using a binder containing polyvinyl alcohol as a main component lacks hardness when heated as compared with mineral wool using a binder containing phenol resin as a main component. , It was found that there is room for improvement in handleability in a heated state, such as when taking out mineral wool after press molding.

Further, when the inventors examined the composition of the binder for the purpose of improving the hardness at the time of heating, the hardness at the time of heating was improved depending on the composition of the binder, but an odor was generated at the time of heating. We have found a new problem that workability is impaired.

Therefore, a main object of the present invention is that with respect to mineral wool using a binder containing a polyvinyl alcohol resin, the hardness of the mineral wool during heating can be improved and the generation of odor can be suppressed. To provide a binder composition for use.

One aspect of the present invention relates to a binder composition for mineral wool containing a polyvinyl alcohol resin, an isocyanate compound having two or more reactive groups selected from an isocyanate group and a blocked isocyanate group, and an aqueous solvent. In the binder composition for mineral wool, the content of the isocyanate compound may be 12 to 90 parts by mass with respect to 100 parts by mass of the content of the polyvinyl alcohol resin.

The binder composition may further contain a surfactant. In the binder composition, the surfactant may be a nonionic surfactant.

In the above binder composition, the isocyanate compound may be a hexamethylene diisocyanate compound, a diphenylmethane diisocyanate compound, a blocked hexamethylene diisocyanate compound, or a blocked diphenylmethane diisocyanate compound.

One aspect of the present invention relates to an intermediate fiber base material containing an inorganic fiber and the binder composition attached to the inorganic fiber.

Another aspect of the present invention relates to mineral wool containing inorganic fibers and a binder attached to the inorganic fibers. In mineral wool, the binder contains a polyvinyl alcohol resin and an isocyanate compound having two or more reactive groups selected from an isocyanate group and a blocked isocyanate group, and the polyvinyl alcohol resin is crosslinked with the isocyanate compound. In the binder composition for mineral wool, the content of the isocyanate compound may be 12 to 90 parts by mass with respect to 100 parts by mass of the content of the polyvinyl alcohol resin.

Another aspect of the present invention is between a step of adhering the binder composition to the inorganic fiber and a step of forming a wool-like intermediate fiber base material containing the inorganic fiber and the binder composition adhering to the inorganic fiber. The present invention relates to a method for producing mineral wool, comprising a step of heating a fiber base material to obtain mineral wool having an inorganic fiber and a binder formed from the above binder composition.

In addition, another aspect of the present invention comprises a step of heating the intermediate fiber base material to obtain mineral wool having an inorganic fiber and a binder formed from the binder composition for mineral wool. Regarding the method of producing wool.

According to one aspect of the present invention, with respect to mineral wool using a binder containing a polyvinyl alcohol resin, the hardness of the mineral wool during heating is improved, and the generation of odor can be suppressed for the mineral wool. Binder compositions are provided. Further, according to one aspect of the present invention, mineral wool using a binder composition containing a polyvinyl alcohol resin, which has improved hardness at the time of heating and suppressed generation of odor, and a method for producing the same. Can be provided.

Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

The binder composition for mineral wool according to the present embodiment (hereinafter, also simply referred to as “binder composition”) is an isocyanate compound having a polyvinyl alcohol resin and two or more reactive groups selected from isocyanate groups and blocked isocyanate groups. And an aqueous solvent.

In the binder composition for mineral wool according to the present embodiment, at least a part of the polyvinyl alcohol resin may be crosslinked. That is, the binder composition may contain a crosslinked polyvinyl alcohol resin, which is a crosslinked product of the polyvinyl alcohol resin. The crosslinked polyvinyl alcohol resin may be a polyvinyl alcohol resin chemically crosslinked with a crosslinking agent. Here, the crosslinked polyvinyl alcohol resin means a polyvinyl alcohol resin that is at least partially chemically crosslinked.

The degree of polymerization of the polyvinyl alcohol resin may be, for example, in the range of 300 to 3000, preferably in the range of 350 to 1000, and more preferably in the range of 400 to 800. The degree of polymerization of the polyvinyl alcohol resin is, for example, a value of the average degree of polymerization obtained by the method specified in JIS K 6726: 1994. The degree of saponification of the polyvinyl alcohol resin may be, for example, in the range of 60 to 100 (mol%), preferably in the range of 75 to 99 (mol%). The degree of saponification of the polyvinyl alcohol resin can be determined by, for example, the method specified in JIS K 6726: 1994. Examples of commercially available polyvinyl alcohol resins include "JL-05E" (polymerization degree: 500, saponification degree: 80 to 84 (mol%)) manufactured by Japan Vam & Poval Co., Ltd.

The binder composition for mineral wool according to the present embodiment contains an isocyanate compound having two or more reactive groups selected from an isocyanate group and a blocked isocyanate group (hereinafter, also simply referred to as “isocyanate compound”) as a cross-linking agent. .. The blocked isocyanate group is obtained by blocking the isocyanate group with a blocking agent. Examples of the blocking agent include methyl ketooxime and caprolactam. The isocyanate compound is preferably an isocyanate compound having two or more blocked isocyanate groups.

Examples of the isocyanate compound include hexamethylene diisocyanate (HDI) -based isocyanate compound, diphenylmethane diisocyanate (MDI) -based isocyanate compound, toluene diisocyanate (TDI) -based isocyanate compound, blocked HDI-based isocyanate compound, blocked MDI-based isocyanate compound, or , Blocked TDI-based isocyanate compounds, preferably HDI-based isocyanate compounds, MDI-based isocyanate compounds, blocked HDI-based isocyanate compounds, or blocked MDI-based isocyanate compounds, and more preferably HDI-based isocyanate compounds. Isocyanate compound or blocked HDI-based isocyanate compound. Here, the HDI-based isocyanate compound means hexamethylene diisocyanate or an oligomer of hexamethylene diisocyanate (for example, a 2 to 10 dimer), and is preferably hexamethylene diisocyanate. The MDI-based isocyanate compound means diphenylmethane diisocyanate or an oligomer of diphenylmethane diisocyanate (for example, a 2 to 10 dimer), and is preferably diphenylmethane diisocyanate. The TDI-based isocyanate compound means toluene diisocyanate or an oligomer of toluene diisocyanate (for example, 2 to 10 mer), and is preferably toluene diisocyanate.

The isocyanate compound may be a commercially available product. Examples of commercially available isocyanate compounds include "Elastron BN11", "Elastron BN77", and "F2462D1" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., and "Meisei Chemical Works, Ltd." "Meicanate TP10" and "SU268A". ..

The content of the isocyanate compound is preferably 12 to 90 parts by mass with respect to 100 parts by mass of the polyvinyl alcohol resin. When the content of the isocyanate compound is 12 parts by mass or more, the generation of odor is further suppressed. Further, when the content of the isocyanate compound is 90 parts by mass or less, the hardness at the time of heating is further improved. The content of the isocyanate compound may be 14 to 70 parts by mass, 16 to 50 parts by mass, 18 to 40 parts by mass, or 20 to 30 parts by mass with respect to 100 parts by mass of the polyvinyl alcohol resin.

The total content of the polyvinyl alcohol resin and the isocyanate compound is more economical for industrial production than the total mass of the components of the binder composition other than the aqueous solvent (hereinafter, also simply referred to as “solid content”). Therefore, it may be 70 to 92% by mass, 80 to 91% by mass, or 85 to 90% by mass.

The binder composition for mineral wool of the present embodiment may contain a cross-linking agent other than the isocyanate compound. The cross-linking agent other than the isocyanate compound may have two or more reactive groups that react with the hydroxyl group of the polyvinyl alcohol resin to form a covalent bond or a non-covalent bond, and examples thereof include aliphatic carboxylic acids. Examples thereof include homopolymers or copolymers containing an aliphatic carboxylic acid as a monomer unit, boron compounds, or combinations thereof. The proportion of the isocyanate compound based on the total mass of the cross-linking agent may be more than 50% by mass, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.

In the binder composition or the binder formed from the binder composition, not all of the cross-linking agents need to form covalent or non-covalent bonds with the hydroxyl groups of the polyvinyl alcohol resin.

The binder composition according to this embodiment contains an aqueous solvent. The aqueous solvent means water or a hydrophilic solvent that can be compatible with water at an arbitrary ratio. The aqueous solvent can be used as a solvent or a dispersion medium for the components contained in the binder composition. Examples of the aqueous solvent include water, methanol, ethanol, ethylene glycol, glycerin and the like, and water is preferable from the viewpoint of economy and handleability. The aqueous solvent may be used alone or in combination of two or more.

The pH of the binder composition according to this embodiment is preferably 7.0 to 10.0, 7.5 to 9.5, 8.1 to 9.5, or 8.8 to 9.2. When the pH of the binder composition is within this range, corrosion of the mineral wool production equipment can be prevented or suppressed. The pH can be adjusted, for example, by adding a pH adjusting agent (for example, ammonia, various carboxylic acids). pH can be measured with pH test paper.

The binder composition according to the present embodiment may further contain a surfactant. Examples of the surfactant include nonionic surfactants and anionic surfactants. The surfactant is preferably a nonionic surfactant from the viewpoint of further improving the hardness of the mineral wool when heated.

The binder composition according to the present embodiment may further contain a dustproofing agent. Examples of the dustproof agent include oil emulsions and the like. An example of a commercially available dustproof agent is a heavy oil emulsion "Daphne Prosolve PF" manufactured by Idemitsu Kosan Co., Ltd. The content of the dustproof agent may be 1 to 30 parts by mass with respect to 100 parts by mass of the crosslinked polyvinyl alcohol resin.

The binder composition according to the present embodiment may further contain a water repellent. Examples of the water repellent include silicone-based additives such as silicone oil emulsions and fluorine-based additives. An example of a commercially available water repellent is a silicone oil emulsion "Polon MR" manufactured by Shin-Etsu Chemical Co., Ltd. The content of the water repellent agent may be 0.05 to 20 parts by mass with respect to 100 parts by mass of the crosslinked polyvinyl alcohol resin.

The binder composition according to the present embodiment may further contain a silane coupling agent. The silane coupling agent contributes to the interfacial adhesion between the crosslinked polyvinyl alcohol resin and the inorganic fiber. Examples of the silane coupling agent include aminosilane coupling agents such as 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, and aminopropyltriethoxysilane, and 3-glycidoxypropyl. Examples thereof include epoxysilane coupling agents such as trimethoxysilane and 3-glycidoxypropylmethyldimethoxysilane. An example of a commercially available silane coupling agent is aminopropyltrimethoxysilane "KBE903" manufactured by Shin-Etsu Chemical Co., Ltd. One type of silane coupling agent may be used alone, or two or more types may be used in combination. The content of the silane coupling agent is preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the crosslinked polyvinyl alcohol resin from the viewpoint of water solubility and reactivity of the polyvinyl alcohol resin and manufacturing cost. .. When the content of the silane coupling agent is 0.1 parts by mass or more, sufficient interfacial adhesion between the crosslinked polyvinyl alcohol resin and the inorganic fiber can be easily obtained. The silane coupling agent also contributes to fixing the silicone-based additive to the surface of the inorganic fiber. Therefore, the water resistance of mineral wool can be further improved by using it in combination with a silane coupling agent and a water repellent such as a silicone-based additive.

The binder composition according to the present embodiment may further contain other components, if necessary, in addition to the components exemplified above. Examples of other components include adhesive inhibitors, mold release agents, colorants, dihydrazides that contribute to maintaining the shape of mineral wool, and the like.

The solid content concentration in the binder composition, that is, the content of the components other than the aqueous solvent is preferably 2.0 to 20% by mass with respect to the total amount of the binder composition. When the content of the component other than the aqueous solvent is 2.0% by mass or more, the time required for the heat treatment for drying the mineral wool is shortened, and the productivity tends to be improved. When the content of the component other than the aqueous solvent is 20.0% by mass or less, the viscosity of the solution (binder composition) is sufficiently lowered, and the permeability to the wool-like inorganic fiber is improved. From the same viewpoint, it is more preferable that the content of the component other than the aqueous solvent is 2.0 to 10.0% by mass.

The binder composition according to the present embodiment contains, for example, an aqueous solution containing a polyvinyl alcohol resin, an isocyanate compound, and, if necessary, a dustproof agent, a water repellent agent, a silane coupling agent, and other components together with water. It is obtained by mixing and stirring, and if necessary, adding water to adjust the content of the above components. The reaction between the polyvinyl alcohol resin and the isocyanate compound proceeds during the preparation of the binder composition for mineral wool and / or by heating the binder composition for mineral wool.

The intermediate fiber base material according to the present embodiment contains an inorganic fiber and the above-mentioned binder composition for mineral wool attached to the inorganic fiber. Since the intermediate fiber base material according to the present embodiment contains an aqueous solvent, it is wet and flexible, so that it can be molded into an arbitrary three-dimensional shape.

The mineral wool according to the present embodiment contains inorganic fibers and a binder attached to the inorganic fibers. In mineral wool, the binder contains a polyvinyl alcohol resin and an isocyanate compound having two or more reactive groups selected from an isocyanate group and a blocked isocyanate group, and the polyvinyl alcohol resin is crosslinked with a cross-linking agent. The content of the isocyanate compound may be 12 to 90 parts by mass with respect to 100 parts by mass of the content of the polyvinyl alcohol resin. Since the mineral wool according to the present embodiment does not substantially contain an aqueous solvent and has an appropriate hardness, it is used for a sound absorbing material for automobiles and other objects having a complicated shape without further processing. It can be used as a heat insulating / sound absorbing material.

Mineral wool is a wool-like fiber aggregate containing inorganic fibers, and the inorganic fibers are bound to each other via a binder or a binder composition. The inorganic fiber may be a glass fiber, a blast furnace slag containing silicate and lime as main components, or a fiber made from rock or the like. Mineral wool containing glass fiber as an inorganic fiber is generally called glass wool. As inorganic fibers, blast furnace slag containing silicic acid and lime as main components, or mineral wool containing fibers made from rocks and the like is generally referred to as rock wool. The mineral wool is preferably glass wool containing glass fibers from the viewpoint of having more excellent heat insulating properties and sound absorbing properties.

The density of mineral wool may be 10 to 250 kg / m ³ . The density and thickness of mineral wool can be measured according to JIS A 9521: 2014. The density here is an apparent density based on the volume including the void volume. The mineral wool may be in the form of a mat, and the thickness of the mat-like mineral wool may be, for example, 10 to 300 mm.

The fiber diameter (including the thickness of the binder) of the inorganic fibers constituting the mineral wool is preferably 3.0 to 10.0 μm, 3.5 to 8.0 μm, or 4.0 to 7.0 μm. The fiber diameter here is a value measured by the micronea method. The fiber length of the inorganic fibers constituting the mineral wool is preferably 2.0 to 500.0 mm.

The binder is formed by heating the binder composition according to the above-described embodiment. That is, the binder can also be said to be a cured product or a heat-treated product of the binder composition.

The amount of the binder attached may be 0.5 to 15.0 parts by mass or 1.0 to 6.0 parts by mass with respect to 100 parts by mass of mineral wool. The amount of the binder attached can be measured by the method described in Examples described later.

The mineral wool according to the present embodiment is intermediate between, for example, a step of adhering the binder composition to inorganic fibers and a step of forming a wool-like intermediate fiber base material containing the inorganic fibers and the binder composition attached thereto. It can be produced by a method including a step of heating a fiber base material. Further, the intermediate fiber base material before heating may be used as it is as mineral wool.

In the step of adhering the binder composition to the inorganic fiber, for example, the binder composition is attached to the formed inorganic fiber while fiberizing an inorganic raw material such as heat-melted glass or a mineral such as rock to form the inorganic fiber. May be attached. As a method for converting the inorganic fiber into fibers, for example, a usual method such as a flame method, a blow-off method, or a centrifugation method (also referred to as a rotary method) can be used. When producing glass wool, the centrifugation method is preferably used as the method for fiberization. As a method of adhering the binder composition to the inorganic fiber, for example, a method of spraying the mist-like binder composition onto the inorganic fiber with a spray device or the like can be used.

A wool-like intermediate fiber base material can be formed by depositing the inorganic fibers to which the binder composition is attached while adhering the binder composition to the inorganic fibers. The deposited inorganic fibers gradually become entangled with each other and take a wool-like form. The binder composition may be attached to the inorganic fiber at any time after the inorganic fiber is formed, but since the binder composition is easily attached to the inside of the intermediate fiber base material, it is immediately after the formation. It is preferable to attach the binder composition to the inorganic fiber and then form a wool-like intermediate fiber base material.

By heating the intermediate fiber base material, the binder composition attached to the inorganic fiber is heat-cured to form a binder, and mineral wool containing the inorganic fiber and the binder attached to the inorganic fiber can be obtained. The method for heating the intermediate fiber base material is not particularly limited. For example, the intermediate fiber substrate can be heated by passing through one or more heating zones set to a predetermined heating temperature. The plurality of heating zones may be installed in series along the transport direction of the intermediate fiber base material. The heating temperature may be set so as to remove the aqueous solvent from the binder composition. For example, the average heating temperature may be 200 ° C. or higher, 200 ° C. or higher and 250 ° C. or lower, or 210 ° C. or higher and 240 ° C. or lower. Is preferable. When the average heating temperature is within these ranges, the generation of undried portions (residual water) in the mineral wool can be prevented or suppressed, and as a result, the resilience of the mineral wool is ensured.

When the intermediate fiber base material is heated by passing through n heating zones that can be set to predetermined heating temperatures, the average heating temperature _Tave is a value calculated by the following formula (1). In the formula (1), L _i represents a distance intermediate fiber substrate is carried in each heating zone, T _i denotes the set temperature of each heating zone. i indicates the number of heating zones, which is an integer greater than or equal to 1.

The heating time of the intermediate fiber base material is appropriately adjusted depending on the density and thickness of the inorganic fibers to which the binder composition is attached. The heating time may be, for example, 30 seconds to 10 minutes, or 2 minutes to 10 minutes.

The intermediate fiber base material after the heating step, that is, mineral wool, may be formed into, for example, a mat, if necessary, and further cut into a desired width and length.

The mineral wool may be used as it is, or the surface of the mineral wool may be coated with a skin material to prepare a member such as a panel having the mineral wool and the skin material. The skin material is not particularly limited, but is, for example, paper (particularly heat-resistant paper, for example, glass paper), synthetic resin film, metal foil film, non-woven fabric (for example, glass chopped strand mat), woven fabric (for example, glass fiber woven fabric). ) Or a combination of these can be used.

The mineral wool according to the present embodiment can be suitably used, for example, as a material having a heat insulating / sound absorbing function. In particular, the mineral wool according to the present embodiment can be particularly preferably used as a sound absorbing material for automobiles (particularly, a sound absorbing material arranged on the back of the bonnet).

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

<Preparation of binder composition>
Example 1
Polyvinyl alcohol resin ("JL-05E" manufactured by Japan Vam & Poval Co., Ltd .; aqueous solution) having a degree of polymerization of 300 and a degree of saponification of 88%, 100 parts by mass (solid content equivalent), heavy oil emulsion which is a dustproof agent ("Daphne Prosolve PF" manufactured by Idemitsu Kosan Co., Ltd.) 15.0 parts by mass (solid content conversion) and 0.5 parts by mass of γ-aminopropyltriethoxysilane, which is a silane coupling agent (solid content conversion) Was mixed and stirred, and the solid content concentration of the obtained mixed solution was adjusted with water so as to be 4.0% by mass. A blocked solution of an HDI-based isocyanate compound (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Elastron BN11) containing a nonionic surfactant as a cross-linking agent was added to the obtained mixed solution with a polyvinyl alcohol resin content of 100. The cross-linking agent (isocyanate compound) was added so as to have a content of 25 parts by mass (in terms of solid content) with respect to the mass to obtain the binder composition of Example 1. The pH of the obtained binder composition was 9.0. Here, the pH was measured with a pH test paper. The "solid content" here is the amount of solid components remaining after the aqueous solvent is volatilized and dried (the content of components other than the aqueous solvent). The addition of the solution of the isocyanate compound was carried out immediately before the binder composition was attached to the glass fiber.

Example 2
Example 2 in the same manner as in Example 1 except that a solution of a blocked MDI-based isocyanate compound containing a nonionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: F2462D1) was used as the cross-linking agent. Binder composition was obtained.

Example 3
Example 3 in the same manner as in Example 1 except that a solution of a blocked TDI-based isocyanate compound containing a nonionic surfactant (manufactured by Meisei Chemicals, trade name: Maycanate TP10) was used as the cross-linking agent. A binder composition was obtained.

Example 4
The binder of Example 4 in the same manner as in Example 1 except that a solution of a blocked HDI-based isocyanate compound containing an anionic surfactant (manufactured by Meisei Chemicals, trade name: SU268A) was used as the cross-linking agent. The composition was obtained.

Example 5
Example 5 in the same manner as in Example 1 except that a solution of a blocked MDI-based isocyanate compound containing an anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Elastron BN77) was used as the cross-linking agent. Binder composition was obtained.

Comparative Example 1
A binder composition of Comparative Example 1 was obtained in the same manner as in Example 1 except that the amount of the cross-linking agent was changed to 100 parts by mass.

Comparative Example 2
A binder composition of Comparative Example 2 was obtained in the same manner as in Example 1 except that the amount of the cross-linking agent was changed to 10 parts by mass.

(Manufacturing of glass wool)
The heat-melted raw material glass was introduced into a fiberizing apparatus, and the heat-melted raw material glass was ejected into a fibrous form by a centrifugation method to form glass fibers. When the formed glass fibers were air-cooled, the binder compositions of Examples or Comparative Examples were atomized and sprayed to attach the binder composition to the glass fibers. The glass fibers to which the binder composition was attached were deposited to form a wool-like intermediate fiber base material. At this time, the water content of the obtained intermediate fiber base material was set to 5% or less.

The obtained intermediate fiber base material was prepared at a basis weight of 1000 g / m ² , heated under the conditions of an average heating temperature of 200 ° C. and a heating time of 5 minutes, and press-molded into a shape of 300 mm × 300 mm × 15 mm. As a result, a mat-like glass wool containing glass fibers to which a binder was attached was obtained. By heating, a binder containing a polyvinyl alcohol resin crosslinked with an isocyanate compound was formed.

(Amount of binder attached)
First, the mass of glass wool (mass before incineration) was measured, and then the binder was incinerated by heating in an air atmosphere at 500 ° C. for 30 minutes. The mass of the remaining glass fiber (mass after incineration) was measured, and the amount of the binder adhered was calculated by the following formula. In both the glass wool of the examples and the comparative examples, the amount of the binder adhered was 3.1 parts by mass with respect to 100 parts by mass of the glass wool.
Binder adhesion = (mass before incineration-mass after incineration) / mass before incineration x 100

(Evaluation of odor (press workability))
After the glass wool was obtained by press molding, the glass wool was taken out without cooling the press molding machine. At this time, the case where 10 workers performed the same work and the number of workers who felt discomfort due to the odor was 2 or less was evaluated as “◯”, and the case where 3 or more workers were evaluated as “x”. The results are shown in Table 1.

(Evaluation of hardness during heating)
After obtaining the glass wool by press molding, the hardness at the time of heating was evaluated by taking out the glass wool without cooling the press molding machine. At this time, the one that was bent by its own weight when the center of one side of the glass wool was taken out with a glove was marked with "x", and the one that was not bent was marked with "○". The results are shown in Table 1.

(Measurement of load fluctuation during heating)
For the binder composition whose hardness is evaluated as "○" during heating, in order to quantitatively compare the degree of improvement in the hardness of glass wool during heating by the binder composition, the load fluctuation during heating is performed by the following procedure. The amount was measured. The results are shown in Table 1.

First, water was added to the binder compositions of Examples and Comparative Examples 1 to adjust the solid content concentration to 2%. The binder composition having an adjusted solid content concentration was impregnated with glass paper (manufactured by Whatman, trade name: GF / A, diameter 70 mm), and then dried at 180 ° C. for 10 minutes to have a width of 30 mm and a length of 50 mm. A sample for measurement was prepared by cutting into a size.

Next, the measurement sample was sandwiched between jigs so that the length of the portion not fixed to the jig was 30 mm from the short side of the prepared measurement sample, and the measurement sample was held in the horizontal direction. Next, a 1 g double clip (width 13 mm) was attached as a weight to the tip of the measurement sample not fixed to the jig. When attaching the double clip, the measurement sample was inserted into the double clip so that the tip position of the measurement sample reached the back of the double clip clip.

Next, the measurement sample was placed in a constant temperature bath (manufactured by Yamato Scientific Co., Ltd., trade name: DN43N) at 220 ° C. while attached to a jig and heated, and the measurement sample was taken out after 10 minutes.

Next, the amount of sagging of the tip that is not fixed to the jig of the measurement sample (the amount of load fluctuation during heating) based on the position of the tip that is not fixed to the jig of the measurement sample before removing the double clip and attaching the double clip. Was measured. The results are shown in Table 1. Here, the smaller the amount of load fluctuation during heating, the greater the degree of improvement in the hardness of the glass wool by the binder composition.

Claims (8)

Polyvinyl alcohol resin and
An isocyanate compound having two or more reactive groups selected from an isocyanate group and a blocked isocyanate group,
A binder composition for mineral wool containing an aqueous solvent.
A binder composition for mineral wool, wherein the content of the isocyanate compound is 12 to 90 parts by mass with respect to 100 parts by mass of the content of the polyvinyl alcohol resin. The binder composition for mineral wool according to claim 1, further containing a surfactant. The binder composition for mineral wool according to claim 2, wherein the surfactant is a nonionic surfactant. Any one of claims 1 to 3, wherein the isocyanate compound is a hexamethylene diisocyanate compound, a diphenylmethane diisocyanate compound, a blocked hexamethylene diisocyanate compound, or a blocked diphenylmethane diisocyanate compound. The binder composition for mineral wool according to the section. An intermediate fiber base material containing an inorganic fiber and the binder composition for mineral wool according to any one of claims 1 to 4 attached to the inorganic fiber. It contains an inorganic fiber and a binder attached to the inorganic fiber.
The binder contains a polyvinyl alcohol resin and an isocyanate compound having two or more reactive groups selected from an isocyanate group and a blocked isocyanate group.
The polyvinyl alcohol resin is crosslinked with the isocyanate compound,
Mineral wool in which the content of the isocyanate compound is 12 to 90 parts by mass with respect to 100 parts by mass of the content of the polyvinyl alcohol resin. The step of adhering the binder composition for mineral wool according to any one of claims 1 to 4 to the inorganic fiber,
A step of forming a wool-like intermediate fiber base material containing the inorganic fiber and the binder composition for mineral wool attached thereto, and
A method for producing mineral wool, comprising a step of heating the intermediate fiber base material to obtain mineral wool having the inorganic fiber and a binder formed from the binder composition for mineral wool. A method for producing mineral wool, comprising a step of heating the intermediate fiber base material according to claim 5 to obtain mineral wool having the inorganic fiber and a binder formed from the binder composition for mineral wool. ..