【発明の詳細な説明】
本発明は天然ガラス粒体が発泡融着してなる成
形体に関し、さらに詳しくは天然ガラス流体の発
泡融着成形体において全発泡気孔のうち連通孔が
80％以上である無機質軽量発泡成形体に関するも
のである。
すなわち、本発明の目的は不燃性の成形体、た
とえば不燃性の板状成形体で、かつ軽量、断熱
性、吸音性、過性などに優れ、しかも耐火性に
極めて優れた無機質軽量発泡成形体を提供するこ
とである。
従来より天然ガラス粒体、たとえば黒曜石、真
珠岩、松脂岩などを高温で加熱発泡させ、圧力を
加えて融着一体化して軽量発泡成形体を得る製造
方法が各種提案されている。本発明者等らは、上
述した各種天然ガラスを用いて800〜1300℃の温
度雰囲気中で加熱発泡させ、加圧することによつ
て融着一体化した軽量発泡成形体を得ることを確
認してきた。
すなわち、天然ガラスを800〜1300℃で数分間
加熱すると、天然ガラスは20〜30倍の発泡倍率
（発泡後の発泡粒体積／発泡前の原石の体積）で
体積増加を行い、各種の方法で圧力を加えること
によつて容易に成形体となすことができる。こう
して得られた天然ガラス軽量発泡成形体は、大部
分の気孔が隔壁で区切られた微細なセルで構成さ
れているため極めて優れた断熱性を示しており、
各分野で断熱材としての利用価値は大きい。
しかしながら、高温度、たとえば500〜1000℃
における耐火性を備えた工業用断熱材の分野では
成形体が破損し易く、使用にあたつては限定され
るものである。これは従来の製造方法で作製した
発泡粒では、発泡粒内に微細な独立気孔が占める
割合が大きく、成形体の温度上昇に伴う気孔の爆
裂、および熱歪みによる収縮差で成形体が破壊す
るものと思われる。
また、従来の製造方法で作製された発泡体は独
立気孔の割合が多いため、断熱材以外の用途には
応用範囲が限定され、多機能性に欠けていた。
また、天然ガラスを予め加熱発泡させて発泡粒
を成形し、それらを有機、無機のバインダーを用
いて緻密に接着して成形体とするものも各種提案
されているが、有機質バインダーでは耐火性が極
めて低く、耐火性の高い無機質バインダーは用い
たものは、生産性、経済性の面から好ましくな
い。さらには、このように予め発泡した発泡粒を
バインダーで集合体としたものは、連通孔が発泡
粒自体の構造ではなく、発泡粒間の空隙によつて
構成されているため、吸音性、過性などの点に
おいて本発明のごとく優れた性能は期待できな
い。
本発明は上記の欠点を解決するため鋭意研究を
重ねた結果、天然ガラスを従来よりもはるかに大
きく発泡させることによつて可能としたものであ
りその目的は軽量、断熱性かつ耐火性に優れ、し
かも吸音性、ひいては過性などにも優れた多機
能無機質軽量発泡成形体を提案するものである。
すなわち、本発明は天然ガラス粒体の発泡融着
成形体であつて、嵩密度が0.40ｇ／cm3以下、かつ
全発泡気孔のうち80％以上が連通孔であるにも拘
らず熱伝導率が0.10Kcal／ｍhr℃以下である無機
質軽量発泡成形体である。このような成形体を得
る方法として、天然ガラス粒体を加熱発泡させる
以前に、たとえは水蒸気雰囲気中で600〜900℃で
５〜150分の前処理を行うことによつて天然ガラ
ス粒体の発泡倍率を極めて向上させる技術を使用
することができる。さらには、本発明者等が先に
提案したごとく天然ガラス粒体を加熱発泡させる
過程において、加熱昇温速度を10〜50℃／minで
発泡温度まで調整することによつて極めて発泡性
を向上させる技術も使用できる。
これらの優れた技術を用いることによつて、は
じめて従来の製造方法では得られなかつた高発泡
倍率（30倍以上）の発泡粒を作製することが可能
となり、この高発泡粒を作製する過程において、
任意の加圧方式で融着一体化すれば、得られた成
形体の全発泡気孔のうち80％以上を連通孔として
有する軽量発泡成形体を得ることができるととも
に、熱伝導率が0.10Kcal／ｍhr℃以下で、嵩密度
が0.40ｇ／cm3以下の性能を有する軽量発泡成形体
とすることができる。
すなわち、従来の製造方法で得られる発泡倍率
よりもはるかに大きい発泡倍率にすることによつ
て、発泡粒内の微細セル間を破壊させ、かつ発泡
粒間界面においても破壊現象が波及して、加圧融
着して一体化したとき、全発泡気孔のうち80％以
上が連通孔として形成されるものである。尚、加
圧融着して得られる成形体において、発泡粒間の
空隙は、本発明のごとく高発泡倍率ではほとんど
存在しない。
本発明における天然ガラス粒体とは、たとえば
黒曜石、真珠岩、松脂岩などのように加熱によつ
て発泡し体積が増大するものである。これらの内
で、特に黒曜石は本発明の効果を達成するのに適
している。また、本発明における成形体の熱伝導
率は0.10Kcal／ｍhr℃以下であり、嵩密度は0.40
ｇ／cm3以下である。熱伝導率が0.10Kcal／ｍhr℃
以上のものは断熱材としての実用価値が低く、嵩
密度が0.40ｇ／cm3以上のものは軽量性という点で
難がある。さらに、連通孔は発泡体の全発泡気孔
のうち80％以上であり、これ以下では吸音性、
過性が低下する。なお、連通孔は容易に水銀圧入
法、たとえばポロシメーター等で測定することが
できる。
本発明は以上のごとく、天然ガラス粒体の発泡
成形体であつて、嵩密度が0.40ｇ／cm3以下、かつ
全発泡気孔のうち80％以上が連通孔であるにも拘
らず熱伝導率が0.10Kcal／ｍhr℃以下ねあり、軽
量、断熱性かつ耐火性に優れ、しかも吸音性、
過性などにも優れた多機能的無機質軽量発泡成形
体である。
以下、本発明を具体的な実施例によつて説明す
る。
各例で用いた連通孔率は水銀圧入法（ポロシメ
ーター）で測定したものであり、吸音率に関して
はJIS Ａ−1405管内法による建築材料の垂直入射
吸音率の測定方法に準じて測定した。
また、耐火性については50×50×100mmの試験
体を用いて、すでに所定の温度に昇温している電
気炉内へ投入し、試験体が破壊する最高温度、ま
たは、破壊しない時は温度、および線収縮率を測
定した。
なお、線収縮率はJIS−A9510（けい酸カルシウ
ム保温材）に準じて次式により求めた。
熱収縮率（％）＝l1−l2／l1×100
l1；加熱前の線長（105℃乾燥後）
l2；加熱（3hrs）後の線長
実施例 １
長野県和田峠産の黒曜石（平均流径５mm）10ｇ
をマツフル炉内に投入し、1050℃になるまで30
℃／mmの昇温速度で加熱発泡させた。得られた発
泡粒の発泡倍率を測定した結果、平均35倍であつ
た。
同じ黒曜石700ｇを密閉式ステンレス製型枠200
mm（長さ）×200mm（巾）×50mm（高さ）に投入、
マツフル炉を使用して1050℃まで30℃／mmで昇温
させ発泡成形体を得た。得られた成形体の外観お
よび内部を観察したところ、発泡粒子間はすべて
充填されており良好な成形体であつた。得られた
成形体の特性を表−１に示す。
実施例 ２
実施例１で使用した同じ黒曜石を、常に水蒸気
で充満させてある800℃に加熱した回転加熱炉
（ロータリーキルン）に投入し70分処理した。処
理した黒曜石10ｇを、すでに1050℃に昇温してい
るマツフル炉に投入し５分間加熱し発泡させた。
得られた発泡粒の発泡倍率を測定した結果、平均
40倍であつた。
回転加熱炉で処理した同じ黒曜石500ｇをステ
ンレス製型枠（底面が200mm×200mm）に投入し、
すでに1050℃に昇温されているマツフル炉内に入
れて10分間加熱発泡させ、直ちにマツフル炉上面
に設置してある加圧装置で、型枠内の発泡高さが
50mmになるように加圧成形して発泡成形体を得
た。得られた成形体の外観および内部を観察した
ところ、発泡粒子間はすべて充填されており、良
好な成形体であつた。得られた成形体の特性を表
−１に示す。
実施例 ３
実施例１と同じ産地の平均粒径10mmの黒曜石
を、実施例２と同じように800℃雰囲気中の回転
加熱炉で50分間水蒸気処理を行つた。処理した黒
曜石30ｇを、すでに1000℃に昇温しているマツフ
ル炉に投入し５分間加熱発泡させた。得られた発
泡粒の発泡倍率を測定した結果、平均53倍であつ
た。
回転炉で処理した同じ黒曜石320ｇを、実施例
１で使用したと同じ型枠に投入し、すでに1000℃
に昇温されているマツフル炉内に入れて10分間加
熱し発泡させ成形体を得た。得られた成形体の外
観および内部は、実施例１および実施例２と同じ
く発泡粒子間がすべて充填された良好な成形体で
あつた。得られた成形体の特性を表−１に示す。
比較例 １
平均粒径５mmの黒曜石10ｇを、すでに1050℃に
昇温させてあるマツフル炉に投入し、５分間加熱
発泡させた。得られた発泡粒の発泡倍率を測定し
た結果、平均５倍であつた。
同じ黒曜石500ｇを、実施例１で使用したと同
じ型枠に入れ、すでに1050℃に昇温してあるマツ
フル炉内に投入して加熱発泡させ成形体を得た。
得られた成形体は発泡粒子間に空隙が多く存在
し、良好な成形体ではなかつた。成形体の特性を
表−１に示す。ただし、連通孔については発泡粒
子間の空隙が多く、本発明で意図する連通孔では
ないので記載していない。
比較例 ２
平均粒径10mmの黒曜石30ｇを、すでに1050℃に
昇温させてあるマツフル炉内に投入し、５分間加
熱発泡させた。得られた発泡粒の発泡倍率を測定
した結果、平均12倍であつた。
同じ黒曜石360ｇを実施例２で使用したと同じ
型枠に投入し、同じ条件、方法で発泡成形体を得
た。得られた成形体の特性を表−１に示す。
【表】DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molded product formed by foaming and fusing natural glass granules, and more specifically, in a foaming and fusing molded product of natural glass fluid, communication pores out of all foamed pores are
This relates to an inorganic lightweight foam molded product with a content of 80% or more. That is, the object of the present invention is to provide a non-combustible molded article, such as a non-combustible plate-like molded article, which is light in weight, has excellent heat insulation properties, sound absorption properties, hyperthermia, etc., and has extremely excellent fire resistance. The goal is to provide the following. Conventionally, various manufacturing methods have been proposed in which natural glass particles, such as obsidian, nacre, and rosinite, are heated and foamed at high temperatures, and then fused and integrated under pressure to obtain lightweight foam molded bodies. The present inventors have confirmed that by heating and foaming the above-mentioned various natural glasses in an atmosphere at a temperature of 800 to 1300 degrees Celsius and applying pressure, a lightweight foamed molded product that is fused and integrated can be obtained. . In other words, when natural glass is heated at 800 to 1,300 degrees Celsius for several minutes, its volume increases by a 20 to 30 times expansion ratio (volume of foamed particles after foaming/volume of rough stone before foaming), and it can be expanded using various methods. It can be easily formed into a molded body by applying pressure. The natural glass lightweight foam molded product obtained in this way has extremely excellent heat insulation properties because most of the pores are composed of fine cells separated by partition walls.
It has great utility as a heat insulating material in various fields. However, high temperatures, e.g. 500-1000℃
In the field of industrial heat insulating materials with fire resistance, the molded bodies are easily damaged and their use is limited. This is because in foamed granules produced using conventional manufacturing methods, the proportion of fine closed pores within the foamed granules is large, and the pores explode as the temperature of the molded product rises, and the shrinkage difference due to thermal strain causes the molded product to break. It seems to be. In addition, foams produced using conventional manufacturing methods have a high proportion of closed pores, which limits their range of application to uses other than heat insulating materials, and they lack multifunctionality. In addition, various proposals have been made to heat and foam natural glass in advance to form foam beads, and then tightly adhere them using an organic or inorganic binder to form a molded product, but organic binders have poor fire resistance. The use of inorganic binders with extremely low fire resistance is not preferred from the viewpoint of productivity and economy. Furthermore, when pre-foamed foam beads are aggregated with a binder, the communication pores are not formed by the structure of the foam beads themselves, but by the voids between the foam beads, resulting in improved sound absorption and In terms of properties and the like, excellent performance as in the present invention cannot be expected. As a result of extensive research to solve the above-mentioned drawbacks, the present invention was made possible by foaming natural glass to a much larger size than before, and its purpose is to achieve light weight, excellent heat insulation, and fire resistance. In addition, we propose a multifunctional inorganic lightweight foam molded product that is excellent in sound absorption properties and also in transmissibility. That is, the present invention is a foamed and fused molded product of natural glass particles, which has a bulk density of 0.40 g/cm 3 or less, and has a low thermal conductivity even though 80% or more of all foamed pores are continuous pores. It is an inorganic lightweight foam molded product with a temperature of 0.10 Kcal/mhr°C or less. As a method for obtaining such molded bodies, before heating and foaming the natural glass granules, for example, pretreatment of the natural glass granules at 600 to 900°C for 5 to 150 minutes in a steam atmosphere is performed. Techniques can be used that greatly increase the expansion ratio. Furthermore, as previously proposed by the present inventors, in the process of heating and foaming natural glass granules, the foaming performance is greatly improved by adjusting the heating temperature increase rate to the foaming temperature at 10 to 50°C/min. You can also use the technique of By using these excellent technologies, it has become possible for the first time to produce foam beads with a high expansion ratio (more than 30 times) that could not be obtained using conventional manufacturing methods. ,
By fusing and integrating with any pressurizing method, it is possible to obtain a lightweight foamed molded product in which more than 80% of all the foamed pores in the resulting molded product are communicating pores, and the thermal conductivity is 0.10 Kcal/ It is possible to produce a lightweight foamed molded product having a bulk density of 0.40 g/cm 3 or less at mhr°C or less. In other words, by setting the foaming ratio to be much larger than that obtained by conventional manufacturing methods, the microcells within the foamed grains are destroyed, and the destruction phenomenon also spreads to the interface between the foamed grains. When integrated by pressure welding, more than 80% of all foamed pores are formed as communicating pores. In addition, in the molded article obtained by pressure fusion, there are almost no voids between the foamed particles when the foaming ratio is high as in the present invention. The natural glass particles used in the present invention are particles that foam and increase in volume when heated, such as obsidian, nacre, and pinestone. Among these, obsidian is particularly suitable for achieving the effects of the present invention. Furthermore, the thermal conductivity of the molded article in the present invention is 0.10 Kcal/mhr°C or less, and the bulk density is 0.40
g/cm 3 or less. Thermal conductivity is 0.10Kcal/mhr℃
The above materials have low practical value as heat insulating materials, and those with bulk densities of 0.40 g/cm 3 or more have difficulty in being lightweight. Furthermore, the communication pores account for more than 80% of the total foam pores, and if the communication pores are less than 80%, the sound absorption property
Hypersensitivity decreases. Note that the communicating pores can be easily measured using a mercury porosimetry method, such as a porosimeter. As described above, the present invention is a foam molded product of natural glass particles, which has a bulk density of 0.40 g/cm 3 or less, and has a high thermal conductivity even though 80% or more of all foam pores are continuous pores. is less than 0.10Kcal/mhr℃, lightweight, has excellent heat insulation and fire resistance, and has sound absorption properties.
It is a multifunctional, lightweight inorganic foam molded product with excellent properties such as durability. The present invention will be explained below using specific examples. The communicating porosity used in each example was measured by the mercury intrusion method (porosimeter), and the sound absorption coefficient was measured according to the method for measuring the normal incidence sound absorption coefficient of building materials according to the JIS A-1405 in-pipe method. Regarding fire resistance, a 50 x 50 x 100 mm test piece is placed into an electric furnace that has already been heated to a predetermined temperature, and the maximum temperature at which the test piece breaks, or the temperature at which it does not break, is determined. , and linear shrinkage were measured. The linear shrinkage rate was determined by the following formula in accordance with JIS-A9510 (calcium silicate insulation material). Thermal shrinkage rate (%) = l 1 - l 2 / l 1 ×100 l 1 ; Line length before heating (after drying at 105°C) l 2 ; Line length after heating (3 hrs) Example 1 Made in Wada Pass, Nagano Prefecture Obsidian (average flow diameter 5mm) 10g
was placed in the Matsufuru furnace and heated for 30 minutes until it reached 1050℃.
Foaming was carried out by heating at a heating rate of °C/mm. As a result of measuring the expansion ratio of the obtained expanded beads, the average expansion ratio was 35 times. The same 700g of obsidian is made into a sealed stainless steel formwork of 200g.
Insert into mm (length) x 200mm (width) x 50mm (height),
Using a Matsufuru furnace, the temperature was raised to 1050°C at a rate of 30°C/mm to obtain a foamed molded product. When the appearance and interior of the obtained molded product were observed, it was found that all the spaces between the expanded particles were filled, indicating that it was a good molded product. Table 1 shows the properties of the molded product obtained. Example 2 The same obsidian used in Example 1 was placed in a rotary kiln heated to 800°C that was constantly filled with water vapor and treated for 70 minutes. 10g of treated obsidian was placed in a Matsufuru furnace whose temperature had already been raised to 1050°C and heated for 5 minutes to cause foaming.
As a result of measuring the expansion ratio of the obtained expanded beads, the average
It was 40 times hotter. 500g of the same obsidian treated in a rotary heating furnace was placed in a stainless steel mold (bottom 200mm x 200mm).
It is placed in the Matsufuru furnace, which has already been heated to 1050℃, and heated and foamed for 10 minutes.
A foam molded product was obtained by pressure molding to a size of 50 mm. When the appearance and interior of the obtained molded product were observed, all the spaces between the expanded particles were filled, and it was found to be a good molded product. Table 1 shows the properties of the molded product obtained. Example 3 Obsidian with an average grain size of 10 mm from the same production area as in Example 1 was subjected to steam treatment for 50 minutes in a rotary heating furnace in an 800° C. atmosphere in the same manner as in Example 2. 30g of treated obsidian was placed in a Matsufuru furnace whose temperature had already been raised to 1000°C, and heated and foamed for 5 minutes. As a result of measuring the expansion ratio of the obtained expanded beads, the average expansion ratio was 53 times. 320g of the same obsidian treated in the rotary furnace was placed in the same mold used in Example 1, and the temperature was already 1000℃.
The molded product was placed in a Matsufuru furnace where the temperature was raised to 100°C and heated for 10 minutes to foam and obtain a molded product. The appearance and interior of the obtained molded product were the same as those of Examples 1 and 2, and were good in that all spaces between the expanded particles were filled. Table 1 shows the properties of the molded product obtained. Comparative Example 1 10 g of obsidian with an average particle size of 5 mm was placed in a Matsufuru furnace whose temperature had already been raised to 1050° C., and heated and foamed for 5 minutes. As a result of measuring the expansion ratio of the obtained expanded beads, the expansion ratio was 5 times on average. 500 g of the same obsidian was placed in the same mold as used in Example 1, placed in a Matsufuru furnace whose temperature had already been raised to 1050°C, and heated and foamed to obtain a molded body.
The obtained molded product had many voids between the expanded particles and was not a good molded product. Table 1 shows the properties of the molded product. However, the communicating pores are not described because there are many voids between the foamed particles and they are not the communicating pores intended in the present invention. Comparative Example 2 30 g of obsidian with an average particle size of 10 mm was placed in a Matsufuru furnace whose temperature had already been raised to 1050° C., and heated and foamed for 5 minutes. As a result of measuring the expansion ratio of the obtained expanded beads, the average expansion ratio was 12 times. 360 g of the same obsidian was placed in the same mold as used in Example 2, and a foamed molded product was obtained under the same conditions and method. Table 1 shows the properties of the molded product obtained. 【table】