JP2023151497A - Glass short fiber aggregate - Google Patents

Abstract

To provide a glass short fiber aggregate excellent in adiabaticity, sound absorbency, and thickness-restoring property, low in skin irritation and low in cost.SOLUTION: A glass short fiber aggregate includes: glass short fibers having an average fiber diameter of 1.0-4.0 μm; and a binder, where a rate of glass short fibers attached with the binder of the glass short fibers (a binder attached rate) is 10 number% or more, and the binder includes at least one selected from the group consisting of a thermosetting resin and a thermoplastic resin.SELECTED DRAWING: None

Description

The present invention relates to short glass fiber aggregates.

Conventionally, plate-shaped short glass fibers made of short glass fibers (glass wool, etc.) and a binder that adheres the short glass fibers have been used as heat-insulating and sound-absorbing materials installed on the floors, walls, ceilings, etc. of buildings. A fiber aggregate is used.
Bulky short glass fiber aggregates (density of 40 kg/m ³ or less, etc.) are often used as such short glass fiber aggregates. In order to increase quality and reduce transportation and storage costs, it is common to compress and pack the product to 1/3 to 1/8 the volume at the time of manufacture, and then open the package before use to restore it to the standard thickness. On the other hand, the thinner the short glass fibers, the better their insulation and sound absorption properties, but the thinner they are, the more easily they break. Therefore, if they are packed with a high compression ratio, the fibers may break due to the effects of long-term storage or vibration during transportation, causing the thickness to decrease after opening. Resilience may be lacking.

Conventionally, measures have been taken to increase the thickness resilience of short glass fiber aggregates, such as (1) using thicker fibers, (2) increasing the amount of binder attached, and (3) lowering the packing compression ratio. It's here. However, as described below, it has not yet been able to satisfy all of the requirements of high heat insulation and sound absorption, high thickness recovery properties, low skin irritation, and low cost.
(1) When using thick fibers, as the average fiber diameter increases, the heat insulation and sound absorption properties decrease, so in order to improve this, it is common to mix thick fibers and thin fibers to reduce the average fiber diameter. However, thick short glass fibers (fiber diameter of 15 μm or more, etc.) cause skin irritation even if they are contained in even a trace amount.
(2) If the amount of binder attached is increased, the thickness recovery property can be maintained even if the fibers are slightly bent due to compression packing, but the manufacturing cost increases. Furthermore, as the amount of binder attached increases, the fibers become thicker by that amount, which may reduce the heat-insulating and sound-absorbing properties. In addition, especially when the binder is unevenly distributed only at the intersections of short glass fibers, the fibers are likely to break in the exposed areas, making it impossible to improve the thickness recovery sufficiently, and the broken fibers may increase skin irritation.
(3) Although it is possible to reduce the breakage of short glass fibers by lowering the packing compression ratio, transportation and storage costs increase.
For example, when trying to improve heat insulation and sound absorption properties and skin irritation by making short glass fibers into fine fibers, it becomes necessary to increase the amount of binder attached in order to maintain thickness recovery properties above a certain level. As a result, the fibers become thicker or the number of fibers included per unit volume decreases, resulting in problems such as insufficient improvement in heat insulation and sound absorption properties and increased manufacturing costs.

As a method to solve this problem, there is a method (4) of using crimpable fibers. This means that even if the amount of binder attached is small and the fibers are thin, the springback of the crimped fibers can be used to improve the thickness recovery property.

For example, Patent Document 1 discloses a glass composition for manufacturing irregularly shaped glass fibers, which is a composite of two types of glass compositions having a difference in coefficient of thermal expansion of 2.0 ppm/° C. or more. By making a difference in the coefficient of thermal expansion of the glass composition, the glass fibers are not straight but irregularly shaped with curls and undulations. This increases the amount of entanglement between the fibers and improves the thickness recovery property after the compression is released.

Furthermore, Patent Document 2 discloses an irregularly shaped composite glass fiber that is made into a beautiful curled (spiral) fiber by combining two types of glasses with different compositions at a specific glass ratio. . Because of the beautiful curled shape, the fibers have stronger resilience than irregularly crimped fibers, improving thickness recovery, as well as lowering thermal conductivity and improving heat insulation.

Further, Patent Document 3 discloses a fiber aggregate with improved thickness recovery properties by mixing crimped fibers with inorganic fibers such as glass wool. Since the organic crimped fibers include fibers with a relatively small fiber diameter, the heat insulation and sound absorption properties of the fiber assembly can be improved. Furthermore, organic crimped fibers are inexpensive, and by using thermoplastic resin fibers as the organic crimped fibers, it is possible to reduce costs by using this in place of the binder.

Patent No. 2851705 Patent No. 2999264 Japanese Patent Application Publication No. 9-11374

However, since the irregular shaped glass fiber of Patent Document 1 is produced by turning two types of molten glass into one fiber, very special equipment is required, productivity is low, and costs are high. There is a problem. Furthermore, since the shape of the glass fiber is amorphous, there is room for further improvement in order to significantly improve the thickness restorability. Furthermore, compared to single-component glass fibers, two-component glass fibers are difficult to make into fine fibers with an average fiber diameter of 5 μm or less, so further improvements are needed in terms of thermal insulation and sound absorption properties and skin irritation. desired.

Similar to Patent Document 1, the irregularly shaped composite glass fiber of Patent Document 2 is produced by turning two types of molten glass into a single fiber, but in order to control the shape, it is manufactured using a special and This requires elaborate fiberizing equipment, which requires precise flow rate adjustment of the two types of molten glass, making operations difficult, lowering productivity, and increasing costs.

In addition, in the fiber aggregate of Patent Document 3, crimped fibers are mixed with glass wool, and when the fibers are intertwined, the glass wool may break, and the broken glass wool may scatter, worsening skin irritation. There is a risk that thickness recovery properties and heat insulation and sound absorption properties may deteriorate.

Therefore, although the glass fiber is made into fine fibers to improve heat insulation and sound absorption properties and reduce skin irritation, it does not easily break even when compressed and packed at a high compression ratio, has good thickness recovery properties, and is low cost. Some glass fibers are desired.
Therefore, an object of the present invention is to provide a short glass fiber aggregate that has excellent heat insulation properties, sound absorption properties, and thickness recovery properties, has low skin irritation, and is inexpensive.

As a result of extensive studies, the present inventors have discovered that the above problem can be solved by attaching a binder at a specific adhesion rate to thin short glass fibers having a specific average fiber diameter, and have developed the present invention. It was completed.

That is, the present invention is as follows.
[1]
Contains short glass fibers with an average fiber diameter of 1.0 to 4.0 μm and a binder,
The proportion of the short glass fibers to which the binder is attached (binder adhesion rate) among the short glass fibers is 10% or more by number,
The short glass fiber aggregate is characterized in that the binder contains at least one selected from the group consisting of thermosetting resins and thermoplastic resins.
[2]
The short glass fiber aggregate according to [1], wherein the glass composition of the short glass fibers is A glass.
[3]
The short glass fiber aggregate according to [1] or [2], wherein the amount of the binder attached is 1.0 to 8.0% by mass based on 100% by mass of the short glass fibers and the binder. .
[4]
The short glass fiber aggregate according to any one of [1] to [3], having a density of 8 to 40 kg/m ³ .

According to the present invention, it is possible to provide a short glass fiber aggregate that has excellent heat insulation properties, sound absorption properties, and thickness recovery properties, has low skin irritation, and is inexpensive.

It is a SEM photograph obtained by a scanning electron microscope (SEM) (“Auriga” manufactured by Carl Zeiss) of an example of the short glass fiber aggregate of the present embodiment. (a) is a magnification of 1000 times, and (b) is a magnification of 2000 times. An example of the short glass fiber aggregate of this embodiment was observed using FE-SEM (JSM-7800F Prime manufactured by JEOL Ltd.) (observation conditions: acceleration voltage 5 kV, LED (uneven image), UED (backscattered electron composition image)). This is an obtained SEM cross-sectional photograph. It is a SEM cross-sectional photograph used for calculating the adhesion rate of the binder for the short glass fiber aggregate of the example. (a) is an SEM cross-sectional photograph of the short glass fiber aggregate of Example 1, and (b) is an SEM cross-sectional photograph of the short glass fiber aggregate of Example 2. This is an SEM cross-sectional photograph used to calculate the binder adhesion rate of a short glass fiber aggregate of a comparative example. (a) is an SEM cross-sectional photograph of the glass short fiber aggregate of Comparative Example 1, and (b) is a SEM cross-sectional photograph of the glass short fiber aggregate of Comparative Example 2. 3 is an SEM cross-sectional photograph used to calculate the binder adhesion rate of the short glass fiber aggregate of Comparative Example 3.

Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "this embodiment") will be described in detail. The present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist.

<Glass short fiber aggregate>
The short glass fiber aggregate of the present embodiment includes short glass fibers with an average fiber diameter of 1.0 to 4.0 μm and a binder, and the proportion of the short glass fibers to which the binder is attached to the short glass fibers (the proportion of the short glass fibers to which the binder is attached) The binder contains at least one selected from the group consisting of thermosetting resins and thermoplastic resins.

The shape of the short glass fiber aggregate is not particularly limited, but it is preferably a shape that is easy to compress and pack, such as a plate shape, from the viewpoint that transporting and storing it in compressed packaging leads to a reduction in transportation and storage costs. . Further, the size of the short glass fiber aggregate is not particularly limited, but from the same viewpoint, the thickness is preferably 50 to 300 mm.
FIG. 1 is a SEM photograph of an example of the short glass fiber aggregate of this embodiment. In Fig. 1(a), the knob-shaped part inside the circular frame is a part of the short glass fibers to which no binder is attached, and specific components in the glass composition have eluted and become knob-shaped. , binder is attached to other parts. In addition, in Figure 1(b), the adhesion state of the binder (the state where the binder is attached to each short glass fiber or the state where the binder is attached around a bundle of multiple short glass fibers) is also shown. etc.) are observed.

In the short glass fiber aggregate, the proportion of short glass fibers to which a binder is attached (binder adhesion rate) among the short glass fibers is 10% by number or more, preferably 13% by number or more, more preferably 15% by number. % or more. When the adhesion rate of the binder is 10% or more, the fibers are less likely to break, and it is possible to obtain a short glass fiber aggregate with excellent thickness recovery properties and low skin irritation. Further, there is no particular upper limit to the adhesion rate of the binder, but from the viewpoint of thermal conductivity performance, it is preferably 40 number % or less, more preferably 35 number % or less, and even more preferably 30 number % or less.
Examples of methods for controlling the adhesion rate of the binder to 10% or more include a method of lowering the viscosity of the binder, a method of increasing the wettability of the binder, and the like.
The adhesion rate of the binder is determined by the number of short glass fibers to which the binder is attached (Na) and the number of short glass fibers to which no binder is attached (Nb) in the SEM cross-sectional photograph of the short glass fiber aggregate. It can be calculated using the following formula. More specifically, it can be determined by the method described in Examples below.
Binder adhesion rate (number %) = {Na/(Na+Nb)}×100
FIG. 2 shows a SEM cross-sectional photograph of an example of the short glass fiber aggregate of this embodiment. In the SEM cross-sectional photograph, the short glass fibers are observed as white to gray, and the binder is observed as translucent white to gray.

In the short glass fiber aggregate, the amount of the binder attached to the total of 100% by mass of the short glass fibers and binder is preferably 1.0 to 8.0% by mass, more preferably 2.0 to 6.0% by mass. It is mass%, more preferably 3.0 to 6.0 mass%. When the amount of the binder attached is 1.0% by mass or more, the short glass fibers become difficult to break, exhibit excellent thickness recovery properties, and tend to have low skin irritation. Further, when the content is 8.0% by mass or less, deterioration of heat insulation properties and sound absorption properties due to an increase in the fiber diameter of the fibers is reduced, and manufacturing costs tend to be suppressed.
Note that the amount of the binder attached can be determined by the method described in Examples below.

The density of the short glass fiber aggregate is preferably 8 to 40 kg/m ³ , more preferably 10 to 36 kg/m ³ , and still more preferably 14 to 28 kg/m ³ . When the density of the short glass fiber aggregate is 8 kg/m ³ or more, it has excellent thickness recovery properties and is easy to manufacture, which tends to reduce manufacturing costs. Further, if the weight is 40 kg/m ³ or less, it is easy to compress and pack, and transportation and storage costs tend to be suppressed.
Note that the density of the short glass fiber aggregate can be measured in accordance with JIS A 9521.

〈〈Short glass fiber〉
The short glass fibers included in the short glass fiber aggregate of this embodiment are not particularly limited, and those commonly used in the fields of heat insulating materials and sound absorbing materials can be used. For example, among the artificial mineral fiber insulation materials specified in JIS A 9521 Building Insulation Materials, those classified as glass wool as a base material can be mentioned.
The short glass fibers may be used alone or in combination of two or more.

The average fiber diameter of the short glass fibers is 1.0 to 4.0 μm. When the average fiber diameter of the short glass fibers is 1.0 μm or more, manufacturing costs can be reduced and appropriate rigidity tends to be obtained, while when it is 4.0 μm or less, thermal insulation properties, sound absorption properties, Moreover, it is possible to obtain a short glass fiber aggregate having excellent thickness recovery properties and low skin irritation. The average fiber diameter of the short glass fibers is not particularly limited as long as it is 1.0 to 4.0 μm, and may be, for example, 2.0 μm or more, 3.0 μm or more, and 3. It may be 5 μm or less.
Methods for controlling the average fiber diameter of short glass fibers to 1.0 to 4.0 μm include, for example, performing fiberization using a centrifugal method (rotary method), and reducing the outlet of molten glass in the fiberization device. Examples include:
Note that the average fiber diameter of the short glass fibers can be measured by the method described in Examples below.

The fiber length of the short glass fibers is not particularly limited, but is preferably 0.3 to 35 mm, more preferably 0.4 to 30 mm, and even more preferably 0.5 to 25 mm.
The average fiber length of the short glass fibers can be determined by sampling 100 or more fibers, measuring the lengths with a ruler, and averaging the lengths.

The glass composition of the short glass fibers is not particularly limited, but A glass is preferable from the viewpoints of ease of formation into fine fibers and fiber formation at low temperatures, low cost, and biosolubility. Here, A glass refers to glass having an alkali (Na ₂ O, K ₂ O) content of 0.8 to 20% by mass, and is also called alkali-containing glass or soda-lime glass.

The content of the short glass fibers is preferably 92 to 99% by mass, more preferably 94 to 98% by mass, and even more preferably 94 to 97% by mass, based on 100% by mass of the short glass fiber aggregate. be. When the content of short glass fibers is 94% by mass or more, short glass fiber aggregates that have excellent heat insulation properties, sound absorption properties, and thickness recovery properties and are low in skin irritation tend to be obtained, and are 98% by mass or less. This tends to reduce manufacturing costs.

The short glass fibers of this embodiment can be manufactured by, for example, melting glass in a glass melting furnace or the like, and then heating the fiber with gas and air combustion in a fiber forming device and stretching the fiber with compressed air. Can be done. Examples of the fiberization method include the conventionally known centrifugation method (rotary method), flame method, blowing method, and the like. Among these, the centrifugation method is preferred because it is easy to form fine fibers. An example of a fiberizing device using a centrifugal method is a spinner.

<<binder>>
The binder contained in the short glass fiber aggregate of this embodiment includes at least one selected from the group consisting of thermosetting resins and thermoplastic resins.

The thermosetting resin is not particularly limited, and examples thereof include phenolic resins, polyimide resins, melamine resins, urea resins, unsaturated polyester resins, and epoxy resins. Among these, phenolic resins are preferred because they have high fluidity and can be easily adhered to the entire short glass fibers uniformly. Further, it is particularly preferable to use a thermosetting resin that does not contain formaldehyde, since formaldehyde, which is a harmful substance, is not generated and can be used safely.

Thermoplastic resins are not particularly limited, and include, for example, acrylic resins, polyurethane resins, polyester resins, polyolefin resins, polystyrene resins, polyamide resins, polycarbonate resins, polysulfone resins, vinyl acetate resins, and vinyl chloride. - Examples include vinyl acetate resin. Among these, acrylic resin is preferred because it has high fluidity and can be easily adhered uniformly to the entire short glass fiber.
These thermoplastic resins are usually used as an aqueous emulsion in which they are dispersed in water or water and an aqueous solvent such as alcohol.

The binder is contained in a range that does not impair the effects of the present invention, and is eluted from the crosslinking agent, dustproofing agent, coloring agent, coloring agent, pH adjuster, curing accelerator, silane coupling agent, and short glass fiber, if necessary. It may contain additives such as a neutralizing agent for neutralizing alkaline components.

The total content of the thermosetting resin and the thermoplastic resin may be equivalent to the resin content in an organic binder commonly used for glass fibers, and may be, for example, 60. It may be 0 to 99.9% by mass.
Note that the solid content refers to components that do not volatilize when the binder is heated at 1 atm and at a temperature of room temperature (approximately 23° C.) to 100° C. or less. Note that the component other than the solid content (volatile component) is preferably water.

The binder can be adjusted to a predetermined concentration by mixing the above components in a conventional manner and adding water.

<Production method of short glass fiber aggregate>
The short glass fiber aggregate of this embodiment can be produced by, for example, applying or spraying a binder to the short glass fibers using a spray device or the like, collecting the fibers using a stacking conveyor or the like, and then heating the fibers in an oven or the like to harden the binder. It can be manufactured by
In order to efficiently and uniformly adhere the binder to the entire short glass fibers, it is preferable to apply the binder immediately after the fiberization of the glass.
The heat curing temperature is preferably 200 to 350°C. The heat curing time is preferably adjusted appropriately between 30 seconds and 10 minutes depending on the density and thickness of the short glass fiber aggregate.

The short glass fiber aggregate of this embodiment can be suitably used as a heat insulating material, a sound absorbing material, etc. in buildings (houses, buildings, etc.), automobiles, etc.
The short glass fiber aggregate may be used as it is or may be covered with a skin material. As the skin material, for example, paper, synthetic resin film, metal foil film, nonwoven fabric, woven fabric, or a combination thereof can be used.

Hereinafter, the present invention will be explained in more detail with reference to Examples. The present invention is not limited to the following examples unless it exceeds the gist thereof.

The measurement and evaluation methods used in the Examples and Comparative Examples are as follows.

[Average fiber diameter of short glass fibers]
An enlarged image (150x magnification) of the short glass fibers was obtained using an electron microscope, and the fiber diameters of 100 randomly selected short glass fibers were measured with a ruler, and the average value (μm) was determined.

[Binder adhesion rate]
A test piece measuring 30 mm x 30 mm x 20 mm in thickness was cut out from the short glass fiber aggregate. The surface of the test piece was coated with osmium using an osmium coater ("HPC-1SW" manufactured by Vacuum Device Co., Ltd.) in order to clarify the boundary with the embedding resin. The test piece was embedded in epoxy resin, and its cross section was polished using a cross-section polisher ("IB-19520CCP" manufactured by JEOL Ltd.). The processing conditions were as follows: acceleration voltage: 6 kV, cooling temperature of the test piece: -120°C (displayed value), and processing time: about 12 hours. After the processed surface was coated with carbon by ion beam sputtering provided in the cross-section polisher, the processed surface was observed with an FIB-SEM ("Scios" manufactured by FEI, using only the SEM function). The observation conditions were an accelerating voltage of 5 kV, ETD (irregularity image), and T1 (backscattered electron composition image).
In the SEM cross-sectional photograph at 150x magnification, count the number of short glass fibers to which a binder is attached (Na) and the number of short glass fibers to which no binder is attached (Nb), and calculate the binder adhesion rate (number of fibers) using the following formula. %) was calculated.
Binder adhesion rate (number %) = {Na/(Na+Nb)}×100
In addition, in the SEM cross-sectional photograph, the short glass fibers are observed as white to gray, and the binder is observed as translucent white to gray.

[Binder adhesion amount]
A test piece measuring 100 mm x 100 mm x 50 mm in thickness was cut out from the short glass fiber aggregate, and its mass (Wa) was measured. Next, the cut test piece was placed in an electric furnace set at 530°C to decompose and remove the binder. The test piece was taken out from the electric furnace, and the mass (Wb) of the test piece after the binder was decomposed and removed was measured, and the amount of binder attached (mass %) was determined using the following formula.
Binder adhesion amount (mass%) = {(Wa-Wb)/Wa}×100

[Density of short glass fiber aggregate]
The density (kg/m ³ ) of the short glass fiber aggregate was measured in accordance with JIS A 9521.

[Thermal insulation properties of short glass fiber aggregate]
A test piece (200 mm x 200 mm x 50 mm thickness) was cut out from the short glass fiber aggregate, and the thermal conductivity (W/m・K) in the thickness direction of the test piece was measured using a thermal conductivity measuring device in accordance with ISO 22007-6. It was measured.
Regarding the heat insulation property, a case where the thermal conductivity was 0.330 W/m·K or less was evaluated as "○ (good)", and a case where the thermal conductivity was over 0.330 W/m·K was evaluated as "× (poor)".

[Sound absorption properties of short glass fiber aggregate]
Regarding short glass fiber aggregates, a flat sample with a thickness of 50 mm was prepared and a disk-shaped test piece with a diameter of 41 mm was cut out. was measured. The sound absorption coefficient at 100 to 4000 Hz was measured at 20° C. using a “normal incidence sound absorption coefficient measurement system WinZac” manufactured by Nippon Onkyo Engineering Co., Ltd. as a measuring device. Among them, Table 1 shows the measurement results of the sound absorption coefficient at 1000 Hz.
Regarding sound absorption, if there are four frequencies with a sound absorption coefficient of 0.20 or more among the four average sound absorption coefficients of 800 Hz, 1000 Hz, 1250 Hz, and 1600 Hz, it is rated "◎ (excellent)", and if it is 3 points, it is rated "〇". (Good),” a score of 2 points was evaluated as “△ (Poor),” and a score of 1 or less was evaluated as “× (Poor).”

[Skin irritation of short glass fiber aggregate]
A sensitivity test was conducted on 10 monitors in which skin irritation was evaluated on a 5-grade SD method rating scale of 1 to 5 by touching the surface of the short glass fiber aggregate. If the average value of 10 monitors is less than 2.0, ``◎ (excellent)'', if it is 2.0 or more and less than 3.0, ``○ (good)'', and if it is 3.0 or more and less than 4.0, ``◎ (excellent)''. If the score was 4.0 or more, it was rated as "x (poor)".

The raw materials used in the examples and comparative examples are as follows.

[Glass]
・Glass (Glass composition: A glass)

[binder]
・Aqueous phenolic resin binder (contains phenolic resin, crosslinking agent, dustproofing agent (mixture of 99% by mass mineral oil and 1% by mass surfactant), and other additives)
- Water-based acrylic resin binder (manufactured according to Example 1 of Patent No. 6850380. Higher viscosity than the above phenolic resin binder.)

[Example 1]
Glass was melted in a glass melting furnace to obtain a glass melt. Using the glass melt, fiberization was performed using a fiberization device to obtain short glass fibers (average fiber diameter: 3.2 μm). Immediately after fiberization, a phenolic resin binder was sprayed onto the short glass fibers. The amount of binder used was assumed to be 6% by mass based on the total of 100% by mass of short glass fibers and binder after curing. Next, the cotton was collected on a stacking conveyor to have a basis weight of 450 g/m ² , and the binder was cured in a hot press molding machine at 210° C. while compressing it to a thickness of 50 mm. Thereafter, slitting, trim cutting, cutting in the short side direction of the product, etc. were performed to obtain a plate-shaped glass fiber aggregate (thickness: 50 m).
The measurement and evaluation results are shown in Table 1. Further, a SEM cross-sectional photograph used for calculating the binder adhesion rate is shown in FIG. 3(a).

[Example 2]
A short glass fiber aggregate was produced in the same manner as in Example 1 except that the basis weight of the short glass fiber aggregate was 900 g/m ² .
The measurement and evaluation results are shown in Table 1. Further, a SEM cross-sectional photograph used for calculating the binder adhesion rate is shown in FIG. 3(b).

[Comparative example 1]
A short glass fiber aggregate was produced in the same manner as in Example 1, except that the viscosity of the binder was increased by leaving the phenolic resin binder for a certain period of time (about one week) to evaporate water.
The measurement and evaluation results are shown in Table 1. Further, a SEM cross-sectional photograph used for calculating the binder adhesion rate is shown in FIG. 4(a).

[Comparative example 2]
A short glass fiber aggregate was produced in the same manner as in Example 1 except that an acrylic resin binder was used as the binder.
The measurement and evaluation results are shown in Table 1. Further, a SEM cross-sectional photograph used for calculating the binder adhesion rate is shown in FIG. 4(b).

[Comparative example 3]
A short glass fiber aggregate was produced in the same manner as Comparative Example 2, except that the viscosity of the acrylic resin binder was increased by leaving the acrylic resin binder for a certain period of time (about 1 week) to evaporate water.
The measurement and evaluation results are shown in Table 1. Further, a SEM cross-sectional photograph used for calculating the binder adhesion rate is shown in FIG.

The short glass fiber aggregates of Examples had an average fiber diameter of 1.0 to 4.0 μm, and therefore had excellent thickness recovery properties. Furthermore, compared to the comparative example, the short glass fiber aggregate had an excellent balance of heat insulation, sound absorption, and thickness recovery properties, and had low skin irritation. In addition, since the short glass fiber aggregates of the examples have excellent heat insulating properties and sound absorbing properties, they can exhibit high heat insulating properties and sound absorbing properties with a smaller amount of glass when used as heat insulating materials, sound absorbing materials, etc. Manufacturing costs can be reduced. Furthermore, since it has excellent thickness recovery properties, it is possible to increase the packing density during transportation and storage, and reduce transportation and storage costs.

The short glass fiber aggregate of the present invention has excellent heat insulation properties, sound absorption properties, and thickness recovery properties, has low skin irritation, and is low in cost. It can be suitably used as a sound absorbing material.

Claims (4)

Contains short glass fibers with an average fiber diameter of 1.0 to 4.0 μm and a binder,
The proportion of the short glass fibers to which the binder is attached (binder adhesion rate) among the short glass fibers is 10% or more by number,
The short glass fiber aggregate is characterized in that the binder contains at least one selected from the group consisting of thermosetting resins and thermoplastic resins. The short glass fiber aggregate according to claim 1, wherein the glass composition of the short glass fibers is A glass. The short glass fiber aggregate according to claim 1 or 2, wherein the amount of the binder attached is 1.0 to 8.0% by mass based on 100% by mass of the short glass fibers and the binder. The short glass fiber aggregate according to any one of claims 1 to 3, having a density of 8 to 40 kg/m ³ .