JP7436172B2 - Inorganic fiber molded body - Google Patents

Description

The present invention relates to an inorganic fiber molded article containing inorganic fiber as a main component.
Specifically, the present invention relates to an inorganic fiber molded article that has low thermal conductivity, high heat resistance, does not emit smoke or odor when heated, and can be used as a lightweight inorganic heat insulating material.

As non-amorphous inorganic fiber molded bodies mainly composed of inorganic fibers, there are known shapes such as board-like, sheet-like, felt-like, mat-like, block-like, and cylindrical shapes. These products are formed by using inorganic fibers such as rock wool or glass wool with organic binders such as phenolic resin as a binding material, and are widely used for insulation, heat insulation, cold insulation, sound insulation, sound absorption materials, cultivation media, etc. (For example, Patent Document 1).

However, when an inorganic fiber molded article containing an organic substance is heated, the binder, such as a phenol resin, is thermally decomposed, causing smoke and odor. This odor occurs noticeably in the temperature range of 250°C to 400°C.
Furthermore, in a high temperature range, phenol resin etc. burns and loses its function as a binder, resulting in a significant decrease in the durability of the heat insulating material. In particular, in order to delay the spread of fire in the event of a fire, the durability of building materials in high temperature ranges is important.

By heating the binder at a temperature higher than the heat-molding temperature of the binder to the extent that a portion of the binder is carbonized, odor-causing components are vaporized in advance, creating an odorless heat insulating material (inorganic fiber molded product). Techniques have been proposed (for example, Patent Document 2).
There is also a proposal for a technique in which an inorganic deodorizing agent such as zeolite is contained in a heat insulating material made by binding inorganic fibers with an organic binder (for example, Patent Document 3).

Japanese Patent Application Publication No. 2003-327481 Special Publication No. 53-047561 Japanese Patent Application Publication No. 07-139689

INDUSTRIAL APPLICABILITY The present invention can be used as a lightweight inorganic heat insulating material that does not emit or generate little smoke or odor during heating, is lightweight, has low thermal conductivity, and has excellent durability after heating. The purpose is to provide an inorganic fiber molded article.

The present inventors have developed an inorganic fiber molded article that solves the above problems by using a specific inorganic binder and inorganic fiber as main components and setting the content ratio of the components contained in the inorganic binder within a specific range. They found that it can be obtained and completed the present invention.

That is, the present invention provides the following (1) to (3).
(1) An inorganic fiber molded body mainly composed of water, an alkali silicate, and an inorganic binder containing SiO ₂ -containing inorganic powder other than cement and an alkali silicate, and inorganic fibers,
For a total of 100 parts by mass of inorganic components other than water and inorganic fibers in the inorganic binder,
The total mass of the alkali silicate and cement and SiO ₂ -containing inorganic powder other than the alkali silicate is 5 parts by mass or more and 50 parts by mass or less, and the mass of the inorganic fiber is 50 parts by mass or more and 95 parts by mass or less,
The bulk density is 0.15 to 0.37 g/cm ³ ,
An inorganic fiber molded article containing no film-forming polymer .
(2) For a total of 100 parts by mass of inorganic components other than water and inorganic fibers in the inorganic binder,
The inorganic fiber molded article according to (1) above, wherein the mass of the alkali silicate is 1.4 parts by mass or more and 12 parts by mass or less.

According to the present invention, it can be used as a lightweight inorganic heat insulating material that produces no or little smoke and odor when heated, is lightweight, has low thermal conductivity, and has excellent durability after heating. An inorganic fiber molded body is obtained.
According to the present invention, a lightweight inorganic heat insulating material, an inorganic heat insulating material, and an inorganic insulating material that generate no or little smoke and odor during heating, are lightweight, have low thermal conductivity, and have excellent durability after heating. Cold insulation materials, inorganic soundproofing materials, and inorganic sound-absorbing materials can be obtained.
Furthermore, since the binder and inorganic fibers used in the present invention do not contain cement as a main component, the amount of carbon dioxide emitted during the manufacturing of the raw materials is lower than that when cement is used as the raw material for the binder. It's less compared to that.

In Examples, they are a conceptual plan view (a) and a conceptual perspective view (b) of a steel tube used in a thermal durability test.

The inorganic fiber molded article of the present invention is mainly composed of an inorganic fiber and an inorganic binder containing water, an alkali silicate, and an inorganic powder containing SiO ₂ other than cement and an alkali silicate. The total mass of "alkali silicate" and " _SiO2- containing inorganic powder other than cement and alkali silicate" is 5 parts by mass or more and 50 parts by mass or less ( In other words, the inorganic fiber has a mass of 50 to 95 parts by mass (that is, 95 to 50 parts by mass). Here, "the inorganic component other than water in the inorganic binder" is "the inorganic nonvolatile component in the inorganic binder".

The alkali silicate used in the present invention is one or two selected from sodium silicate or sodium silicate aqueous solution such as sodium metasilicate, sodium orthosilicate, water glass, lithium silicate or lithium silicate aqueous solution, potassium silicate or potassium silicate aqueous solution. It is preferable to use more than one species.

The " _SiO2- containing inorganic powder other than cement and alkali silicate" used in the present invention is an inorganic powder other than cement and alkali silicate that contains _SiO2 as a main chemical composition, such as blast furnace slag powder, copper slag powder. , slag powder in metal refining such as ferronickel slag powder; sewage sludge slag burnt powder, municipal waste molten slag powder, fly ash, pulp sludge incineration ash, biomass boiler incineration ash, sewage sludge incineration ash, rice husk ash, silica fume Inorganic powders containing _SiO2 as a main chemical composition produced by various industries such as crushed waste glass, crushed waste ceramics, and tile selben; silica powder, diatomaceous earth powder, talc powder, and clay minerals such as kaolin and bentonate. Powder of _SiO2 -containing minerals ( _SiO2- containing minerals) such as volcanic ash and igneous rock powder; Powder of fired igneous rock and fired product of _SiO2- containing minerals such as metakaolin; Colloidal silica, synthetic silica glass, Preferred examples include powders of inorganic industrial products containing SiO ₂ (SiO ₂ -containing industrial products) such as white carbon, silica gel, and precipitated silica.
The SiO ₂ -containing inorganic powder is preferably one having a Blaine specific surface area of 2000 cm ² /g or more because the binder hardens quickly, and more preferably 2500 cm ² /g or more. Furthermore, the upper limit of the Blaine specific surface area of the SiO ₂ -containing inorganic powder used in the present invention is preferably 12,000 cm ² /g or less, and 10,000 cm ² /g or less, since this allows a long time to maintain the fluidity of the binder. More preferred.

The inorganic binder in the present invention contains water, an alkali silicate, and " _SiO2- containing inorganic powder other than cement and an alkali silicate." In addition to these ingredients, the inorganic binder contains alkali hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkali oxides such as sodium oxide and potassium oxide; and additives such as viscosity modifiers and reaction promoters. , fillers, aggregates, and other extenders may be contained within a range that does not impair the effects of the present invention.

The inorganic fibers used in the present invention are preferably non-metallic inorganic fibers. For example, cotton-like inorganic fibers selected from rock wool, glass wool, ceramic wool, etc. are preferred in terms of durability, sound absorption, or heat insulation. Wool or ceramic wool is more preferred because it can maintain its shape without melting even when exposed to temperatures of 800° C. or higher and is excellent in heat resistance or fire resistance.
In the present invention, rock wool is a material (mineral fiber) obtained by quenching a material mainly composed of rock, blast furnace slag, etc. melted in a melting furnace and turning it into fibers. For example, it also includes slag wool made from materials mainly consisting of blast furnace slag.

In the present invention, for a total of 100 parts by mass of "inorganic components other than water in the inorganic binder" (inorganic nonvolatile components in the inorganic binder) and "inorganic fibers", "alkali silicate" and "other than cement and alkali silicate" are used. The total mass of the SiO ₂ -containing inorganic powder is 5 parts by mass or more and 50 parts by mass or less, and the mass of the inorganic fibers is 50 parts by mass or more and 95 parts by mass or less.

For a total of 100 parts by mass of "inorganic components other than water in the inorganic binder" (inorganic non-volatile components in the inorganic binder) and "inorganic fibers", "alkali silicate" and "cement and SiO ₂ other than alkali silicate" If the total mass including the inorganic powder exceeds 50 parts by mass, the thermal conductivity of the inorganic fiber molded article will increase, and if it is less than 5 parts by mass, the durability after heating will be poor.
In addition, since the thermal conductivity of the inorganic fiber molded body is low and the durability after heating is excellent, "silicic acid It is more preferable that the total mass of "alkali" and " _SiO2- containing inorganic powder other than cement and alkali silicate" is 6 to 48 parts by mass, and the mass of the inorganic fiber is 94 to 52 parts by mass, and "alkali silicate" It is more preferable that the total mass of the "SiO ₂ -containing inorganic powder other than cement and alkali silicate" is 10 to 46 parts by mass, and the mass of the inorganic fibers is 90 to 54 parts by mass.

Here, in the present invention, the mass of the "inorganic component other than water in the inorganic binder" (inorganic nonvolatile component in the inorganic binder) is, when the alkali silicate is an aqueous solution such as water glass, The sum of metal ions converted into oxide (M ₂ O) and silicate ions converted into oxide (SiO ₂ ) (total value of M ₂ O conversion value and SiO ₂ conversion value) is calculated as the mass of alkali silicate.

In the present invention, it is preferable that the amount of water in the inorganic binder is 20 to 150 parts by mass based on 100 parts by mass of the inorganic fibers from the viewpoint of ease of molding.
Here, the amount of water in the present invention is the amount of water during molding of the inorganic fiber molded article, and when the alkali silicate is an aqueous solution such as water glass, the amount of water in the alkali silicate is the amount of water in terms of M ₂ O equivalent value and SiO ₂ equivalent value in the alkali silicate. In other words, the mass obtained by subtracting the "total value of M ₂ O equivalent value and SiO ₂ equivalent value" from the mass of the aqueous alkali silicate solution, and the dispersion system of water, aqueous solution, emulsion, etc. to be added. It is the sum of the mass of water contained in

In the present invention, the content of alkali silicate is 1.4 parts by mass for a total of 100 parts by mass of "inorganic components other than water in the inorganic binder" (inorganic nonvolatile components in the inorganic binder) and "inorganic fibers". If the amount is 1 part or more, the durability after heating is excellent, and if it is 12 parts by mass or less, the water resistance is excellent, so it is preferable, and 2 to 12 parts by weight is more preferable. In addition, if the content of alkali silicate is 12 parts by mass or less based on the total of 100 parts by mass of "inorganic components other than water in the inorganic binder" and "inorganic fibers", excellent water resistance will be achieved. Deterioration of the inorganic fiber molded product is less likely to occur.

In the present invention, when the mass of "inorganic components other than water in the inorganic binder" (inorganic nonvolatile components in the inorganic binder) is 20 parts by mass or more with respect to 100 parts by mass of inorganic fibers, the inorganic fiber molded article This is preferable because the bulk density is greater than 0.20 g/cm ³ and fire resistance is improved. More preferably, when the mass of "inorganic components other than water in the inorganic binder" (inorganic nonvolatile components in the inorganic binder) is 25 parts by mass or more with respect to a total of 100 parts by mass of inorganic fibers, the inorganic fiber molded article The bulk density becomes 0.25 g/cm ³ or more, and the fire resistance performance is further improved.

The inorganic fiber molded article of the present invention contains water, an alkali silicate, an inorganic binder containing "an _SiO2- containing inorganic powder other than cement and an alkali silicate," and other materials than the inorganic fibers that do not impair the effects of the present invention. One or more other components may be included within the range. Examples of the other components include alkali hydroxides, alkali oxides, viscosity modifiers, reaction accelerators, chemical additives such as reaction inhibitors, cement, fillers such as fillers and aggregates, polypropylene fibers, etc. Examples include fibers such as

The inorganic fiber molded article of the present invention can be manufactured by a normal method, and is manufactured without any particular limitation, except that the molded article is formed from an inorganic binder and inorganic fibers in the above-mentioned mixing ratio. be able to.
Examples of methods for producing an inorganic fiber molded article include a method in which an inorganic binder is added to a molded inorganic fiber by spraying so as to have the above-mentioned mixing ratio; A method of manufacturing by molding after adding inorganic fibers, a method of molding a mixture of inorganic fibers and an inorganic binder, and a method of molding a mixture of inorganic fibers and "inorganic components other than water in the inorganic binder". A method of mixing inorganic fibers and an inorganic binder to form a slurry and forming and manufacturing it using a papermaking method or a dehydration pressing method. Preferred examples include a method in which a plurality of inorganic fiber molded bodies are bonded together using an inorganic binder, and a method in which an inorganic fiber molded body produced by any of these methods is shaped by cutting, cutting, etc.

Since the inorganic fiber molded article of the present invention has excellent heat insulation properties and excellent durability after heating, it is preferable that the thermal conductivity is 0.038 to 0.060 W/mK, and 0.038 to 0.055 W. /mK is more preferred.
In the present invention, the thermal conductivity is measured in accordance with JIS A 1412-2, according to the flat plate heat flow meter method, and the measurement conditions are a measurement temperature of 20.0°C and a temperature difference of 20.0°C as shown in the examples below. Measured as .0°C.

Furthermore, since the inorganic fiber molded article of the present invention is lightweight and has excellent durability after heating, it is preferable that the bulk density is 0.15 to 0.37 g/ ^cm3 , and furthermore, it has excellent fire resistance. Therefore, the bulk density is more preferably 0.25 to 0.37 g/cm ³ , most preferably 0.25 to 0.36 g/cm ³ .
In the present invention, the bulk density (ρ) is calculated from the volume (V) obtained by measuring the dimensions of the inorganic fiber molded body using a caliper or the like, and the mass (M) of the inorganic fiber molded body measured using a balance such as an electronic balance. , is obtained using the following equation (1). If the inorganic fiber molded body is large, a portion is cut out, its dimensions and mass (M) are measured, and the bulk density (ρ) is determined.
(formula)
ρ=M/V (1)

The inorganic fiber molded article of the present invention is lightweight, has low thermal conductivity, and has excellent durability after heating, so it can be used as an inorganic heat insulating material, an inorganic heat insulating material, an inorganic cold insulating material, an inorganic sound insulating material, an inorganic sound absorbing material, etc. It can be suitably used as

Inorganic fiber molded bodies were manufactured using raw materials having the composition ratios shown in Tables 1 and 2. It is manufactured by uniformly spraying a binder slurry onto inorganic fibers (rock wool or glass wool), then molding it and drying it at 190°C for 8 hours, resulting in dimensions of 200 mm width x 200 mm depth x thickness. A 30 mm inorganic fiber molded body was obtained.
The following materials were used.
(Materials used)
・Inorganic fiber 1: Rock wool (granular cotton, commercially available)
・Inorganic fiber 2: Glass wool (commercially available)
・Alkali silicate: Sodium silicate (water glass)
・Blast furnace slag: Blast furnace slag powder (Blaine specific surface area: 4130 cm ² /g)
・Water: Sakura City tap water ・Phenol resin: Water-soluble resol type phenol resin (commercially available)

The amounts of alkali silicate and water in Tables 1 and 2 are calculated based on the alkali metal ions in water glass converted into oxide (M ₂ O) and the silicate ions converted into oxide (SiO ₂ ), respectively, and the sum of these values. The mass of the alkali silicate is defined as the mass of the alkali silicate, and the mass of the water is defined as the sum of the mass of other components in the water glass and the mass of separately added water.

The following evaluation tests were conducted on the obtained inorganic fiber molded article. The results are shown in Tables 3 and 4.
The inorganic fiber molded articles shown in Table 2 use glass wool as the inorganic fiber, but these were subjected to odor tests, smoke tests, thermal durability tests, and evaluations of thermal conductivity and bulk density. (Table 4).

(Evaluation test)
(1) Odor test:
One side of the 200 mm x 200 mm surface of the obtained inorganic fiber molded article was heated evenly for 1 minute using a gas burner. A case in which no odor was detected by the human sense of smell during heating was judged as a "pass" in the odor test, and a case in which an odor was detected was judged as a "fail" in the odor test.

(2) Smoke test:
The specimen subjected to the odor test was further heated with a gas burner for 9 minutes in the same manner as in the odor test. A test piece that did not emit smoke during heating was judged as a "pass" in the smoke test, and a test piece that did emit smoke was judged as a "fail" in the smoke test.

(3) Thermal durability test:
A cubic steel tube with a width of 200 mm x depth of 200 mm x height of 200 mm and a thickness of 20 mm (a square opening of 160 mm x 160 mm; Figure 1) is installed on a horizontal surface so that the opening is on the top and bottom. Place the test specimen subjected to the smoke test with the heated side facing up, and place a 200 g weight (width 31 mm x depth 31 mm x height 44 mm) in the center of the top surface of the test piece. , observed for 1 minute. "Excellent" (symbol: ◎) indicates that the test specimen is held in the opening of the steel tube without cracking; "Excellent" (symbol: ◎) indicates that the test specimen is held in the opening of the steel tube without any cracks; The test piece was evaluated as "good" (symbol: 〇) when the weight was maintained, and "poor" (symbol: x) when the test piece could not withstand the weight of the weight and broke.

(4) Thermal conductivity measurement:
The thermal conductivity of the obtained inorganic fiber molded body (width 200 mm x depth 200 mm x thickness 30 mm) was measured in accordance with JIS A 1412-2, according to the flat plate heat flow meter method, and the measurement conditions were a measurement temperature of 20.0°C, Measurements were made with a temperature difference of 20.0°C between the test specimens. If the thermal conductivity is 0.055W/mK or less, it is "excellent" (symbol: ◎), and if the thermal conductivity is greater than 0.055W/mK and 0.060W/Mk or less, it is "good" (symbol: ○). A case where the thermal conductivity exceeded 0.060 W/mK was evaluated as "poor (insufficient)" (symbol: ×).

(5) Fire-resistant performance test (performance evaluation test as fire-resistant coating material)
Water glass was applied as an adhesive to one of the 200 mm x 200 mm surfaces of the obtained inorganic fiber molded body (width 200 mm x depth 200 mm x thickness 30 mm), and it was bonded to a steel plate measuring 200 mm width x 200 mm depth x 9 mm thickness. Ta. A steel plate to which an inorganic fiber molded body was bonded was cured in a room at a temperature of 20±2° C. and a relative humidity of 60±5% until it reached a constant weight, and was used as a test specimen. The 200 mm x 200 mm surface of the test specimen with exposed insulation material was used as the heating surface, and a thermocouple was installed in the center of the steel plate on the back of the specimen, and all surfaces except the heating surface were covered with insulation material, and the heating temperature was set according to JIS. Heating was performed for 1 hour in accordance with the heating curve specified in A 1304, and the temperature at the center of the steel plate was measured 1 hour after the start of heating.

Rock wool spraying material, which is made of rock wool granular cotton used as a fireproof coating and cement paste, was sprayed onto a steel plate measuring 200 mm wide x 200 mm deep x 9 mm thick using a semi-dry construction method. A similar test piece with a fireproof coating layer of 30 mm thickness was prepared and a similar heating test was conducted, and the temperature at the center of the steel material was 310°C.
This temperature is taken as the standard value for the performance as a fireproof coating material, and when the temperature difference from the standard value is less than 20℃ (the temperature at the center of the steel plate is less than 330℃), the performance as a fireproof coating material (fireproof performance ) is "Excellent" (symbol: ◎), and the temperature difference from the standard value is 20°C or more and less than 40°C (the temperature at the center of the steel plate is 330°C or more and less than 350°C). If the performance is "good" (symbol: ○), and the temperature difference from the standard value is 40°C or more (the temperature at the center of the steel plate is 350°C or more), the performance as a fireproof coating material is "poor" (symbol: : ×).

(6) Bulk density measurement:
The bulk density (ρ) is determined by measuring the width (W), depth (L), and thickness (T) of the inorganic fiber molded product at multiple locations using a caliper, determining the volume (V) from the average value of each, and calculating the volume (V) using an electronic balance. It was calculated using the following formula (2) from the measured mass (M) of the inorganic fiber molded article.
(formula)
ρ=M/V=M/(W×L×T)...(2)

As shown in Tables 3 and 4, the inorganic fiber molded articles (No. 2 to No. 9 and No. 12) according to the examples of the present invention did not emit smoke or odor when exposed to high temperatures. It showed high durability against heat. Furthermore, it can be seen that the inorganic fiber molded bodies according to these Examples of the present invention have a thermal conductivity of 0.060 W/mK or less, and can be sufficiently used as a heat insulating material.

In particular, the total mass of "alkali silicate" and "cement and _SiO2 -containing inorganic powder other than alkali silicate" is No. 6 to 48 parts by mass, and the mass of the inorganic fibers is 94 to 52 parts by mass. 3~No. 9 and no. All of the 12 inorganic fiber molded bodies exhibited even more excellent heat durability, with no cracking occurring in the heat durability test.

In addition, for a total of 100 parts by mass of "inorganic components other than water in the inorganic binder" and "inorganic fibers _" , the total mass ( No. 1, in which the mass of the "inorganic nonvolatile component in the inorganic binder" is 10 to 46 parts by mass, and the mass of the inorganic fibers is 90 to 54 parts by mass. 3~No. All of the inorganic fiber molded articles No. 8 exhibited even better thermal insulation performance, with a thermal conductivity of 0.055 W/mK or less.

In addition, the mass of "inorganic components other than water in the inorganic binder" (inorganic nonvolatile components in the inorganic binder) is 25 parts by mass or more per 100 parts by mass of the inorganic fiber, and rock wool is used as the inorganic fiber. , No. 1, which corresponds to an embodiment of the present invention. 6~No. It can be seen that all of the inorganic fiber molded articles No. 10 have a bulk density of 0.25 g/cm ³ or more, and furthermore, have excellent fire resistance performance and can be used satisfactorily as a fire resistant coating material.

1 Steel tube 2 Width 3 Depth 4 Height 5 Thickness 6 Opening 7 Top surface of steel tube

Claims (2)

An inorganic fiber molded body mainly composed of water, an alkali silicate, an inorganic binder containing SiO ₂ -containing inorganic powder other than cement and an alkali silicate, and inorganic fibers,
For a total of 100 parts by mass of inorganic components other than water and inorganic fibers in the inorganic binder,
The total mass of the alkali silicate and cement and SiO ₂ -containing inorganic powder other than the alkali silicate is 5 parts by mass or more and 50 parts by mass or less, and the mass of the inorganic fiber is 50 parts by mass or more and 95 parts by mass or less,
The bulk density is 0.15 to 0.37 g/cm ³ ,
An inorganic fiber molded article containing no film-forming polymer . For a total of 100 parts by mass of inorganic components other than water and inorganic fibers in the inorganic binder,
The inorganic fiber molded article according to claim 1, wherein the mass of the alkali silicate is 1.4 parts by mass or more and 12 parts by mass or less.

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