JPH0238720B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing mineral fiberboard whose fiber component is mineral fiber made of rock wool, mineral wool, or glass wool, and which has properties such as nonflammability, fireproof insulation, and sound absorption. The object of the present invention is to provide a method for economically obtaining mineral fiberboard that exhibits excellent properties such as properties and mechanical strength. [Prior art] The manufacturing method for mineral fiberboard involves uniformly dispersing mineral fibers in a large amount of water equivalent to 10 to 100 times the amount of mineral fibers together with appropriate amounts of binders and additives to form an aqueous slurry. After papermaking and shaping, drying and curing are carried out using a wet papermaking method, and a mixture of mineral fibers and appropriate amounts of binders and additives is added to the mixture.
There is a paste method in which three times as much water is added, the paste is kneaded, extruded or rolled to form a plate, and then dried and solidified. [Problems to be Solved by the Invention] Among the conventional methods for manufacturing mineral fiberboard, the former wet papermaking method is characterized by excellent productivity in mass production. In order to obtain a mineral fiberboard with physical strength such as mechanical strength and hardness, it is necessary to use an aqueous slurry containing a certain amount of an organic binder in the molding composition. A drawback is that there are certain limits to the fireproof performance of the resulting mineral fiberboard, such as nonflammability, fire resistance, and heat insulation. In the method for manufacturing mineral fiberboard by the wet papermaking method, well-beaten gel cellulose, polymer flocculant, Although asbestos and the like are used, the mineral fiberboard obtained from the aqueous slurry containing the gelled cellulose has fireproof properties such as nonflammability, fire resistance, and heat insulation properties due to the gelled cellulose used as a retention and adhesion agent. In addition, polymer flocculants do not have sufficient action as retention/fixing agents, and asbestos dust causes lung cancer.
The reality is that its use is restricted. On the other hand, the method for manufacturing mineral fiberboard of the present invention can produce mineral fiberboard that has various performances such as non-combustibility, fireproof insulation, sound absorption, and mechanical strength in a well-balanced manner, with high productivity and productivity in mass production. The present invention provides a method for obtaining paper using a wet papermaking method with excellent properties. [Means for Solving the Problems] The method for producing a mineral fiberboard of the present invention uses mineral fibers made of rock wool, slag wool, or glass wool.
100 parts by weight, 3 to 25 parts by weight of attapulgite,
It contains 0.1 to 6 parts by weight of sepiolite with a fiber length of 20 μm to 2 mm as an essential solid component, and the weight ratio of the attapulgite to sepiolite with a fiber length of 20 μm to 2 mm is 3 to 30:1, and an organic binder. is 5 parts by weight or less and the total amount of organic components is suppressed to 7 parts by weight or less, that is, the mineral fiber composition is 10 to 100 times the mineral fiber composition. A step of obtaining an aqueous slurry consisting of a dispersion having a solid content of about 1 to 8% by weight, in which the composition is almost uniformly dispersed in an amount of water corresponding to This process consists of a process of papermaking and molding using a papermaking machine such as, etc., and a process of drying and curing the obtained molded sheet. The mineral fibers forming the main solid component in the aqueous slurry used in the method for producing mineral fiberboard of the present invention having the above structure are selected from rock wool, mineral wool, and glass wool. . In addition, the attapulgite used in the aqueous slurry acts as an inorganic binder in the mineral fiberboard obtained, and at the same time, in some cases (up to 5 parts by weight per 100 parts by weight of mineral fibers). It also acts as a retention/fixing agent for organic binders that may be added (in small amounts). Attapulgite, which acts as an inorganic binder for the mineral fibers, is a multi-chain clay with a diameter of 100 Å and a length of 1 to 100 Å.
It is a needle-like crystal substance of several micrometers that has the property of being dispersed in colloidal form in water, and has an extremely large surface area of 210 m ² /g in the dispersed state, and has a high degree of adsorption performance. It is. The sepiolite with a fiber length of 20μ to 2mm contained together with the attapulgite in the aqueous slurry whose main solid component is mineral fiber is the aqueous slurry used in the conventional method for producing mineral fiberboard by wet papermaking. It performs the retention and fixation effects that organic fibers such as waste paper pulp had in the above-mentioned attapulgite, and provides excellent retention and fixation effects for the above-mentioned attapulgite. In addition, the fiber length used in the present invention is 20 μ to 2
mm sepiolite has a fiber length within a predetermined range by pre-selecting sepiolite with a long fiber length and defibrating it using a pulper and a finer without cutting the fibers too short. It is easily obtained in the form of a water-dispersible slurry in which sepiolite exists in gel form. In addition, the sepiolite used in the mineral fiber aqueous slurry has a fiber length.
If the fiber length is less than 20 μm, the retention and fixing effect on attapulgite will be weakened, and if the fiber length is longer than 2 mm, not only will the paper-formability of the aqueous slurry deteriorate, but the mineral fibers obtained will be Since the surface condition of the plate becomes poor, the fiber length of the sepiolite used is within the range of 20 μm to 2 mm. Attapulgite, which is one essential solid component in the aqueous slurry in which the main solid component is mineral fiber, is present in an amount of 3 to 3 parts by weight per 100 parts by weight of mineral fiber.
It is present in a proportion of 25 parts by weight, but this is because if the amount of attapulgite is less than 3 parts by weight, the binder effect of attapulgite cannot be obtained, and the mineral fiber has excellent mechanical strength. This is because the board cannot be obtained. Furthermore, if the amount of attapulgite exceeds 25 parts by weight, the water-based slurry will not only have poor freeness and paper-making properties, but also the water repellency of the resulting mineral fiberboard will decrease. It is also for the purpose of In addition, the fiber length of the other essential solid component in the aqueous slurry is 20μ~
The 2 mm sepiolite is present in a proportion of 0.1 to 6 parts by weight based on 100 parts by weight of mineral fibers, but this means that if the sepiolite is in a small amount of less than 0.1 part by weight, the retention with respect to the above-mentioned attapulgite, The fixing effect is not sufficient, making it impossible to obtain a mineral fiberboard with excellent mechanical strength. Furthermore, if the amount of sepiolite exceeds 6 parts by weight, the freeness of the aqueous slurry deteriorates, making it difficult to make an efficient paper sheet. This is because they will not be able to do so. Further, the weight ratio of the attapulgite and sepiolite having a fiber length of 20 μm to 2 mm, which are essential solid components in the aqueous slurry having the mineral fiber as the main solid component, is within the range of 3 to 30:1. If the ratio of sepiolite exceeds 1 to 3 parts of attapulgite, there will only be a diseconomie due to the excessive amount of sepiolite, and if the ratio of sepiolite to 30 parts of attapulgite is less than 1, the amount of attapulgite achieved by the sepiolite will increase. The retention effect is not sufficient, causing problems such as a decrease in the bending strength of the resulting mineral fiberboard. The aqueous slurry containing mineral fibers as the main solid component contains an organic binder, a binding aid, a water repellent, etc. as necessary. Organic binders such as pulp, raw starch, When the amount of organic binders such as boiled starch, polyvinyl alcohol, gar gum, vinyl acetate emulsion, acrylic emulsion, and phenolic resin exceeds 5 parts by weight per 100 parts by weight of mineral fibers, or when organic binders are used in aqueous slurry. If the total amount of the ingredients exceeds 7 parts by weight, the non-flammability of the resulting mineral fiberboard will decrease and it will be rated "non-flammable" in the British Standards non-flammability test.
Since it becomes difficult to obtain a mineral fiberboard that clears "combustible", it is necessary to suppress the organic binder to 5 parts by weight or less, and the total amount of organic components to 7 parts by weight or less. Note that the binding aid such as polyacrylamide, polyacrylamide modified product, aluminum sulfate, and water repellent can sufficiently exhibit their effects when the total amount thereof is 2 parts by weight or less. [Example] Hereinafter, the specific structure of the method for producing mineral fiberboard of the present invention will be explained using Examples, and the properties of the obtained mineral fiberboard will be explained using the obtained mineral fiberboard for comparison. This will be explained in comparison with quality fiberboard. Examples 1 to 6, Comparative Examples 1 to 7 Solid components (1000 g) consisting of each composition component listed in the Examples 1 to 6 and Comparative Examples 1 to 7 columns of Table 1 below.
An aqueous slurry with a 4% by weight aqueous dispersion of A mineral fiberboard was obtained by drying and curing at ℃ for 4 hours. Table 1 shows the molding and drainage time of each aqueous slurry, as well as the density, bending strength, compressive strength, and nonflammability of the obtained mineral fiberboard. In addition, the molding drainage time of the aqueous slurry in Table 1, the retention rate (%) during the papermaking process,
The methods for measuring various physical properties of the obtained mineral fiberboard are as follows. Filtration time during papermaking: Filtration time when making each aqueous slurry using a test papermaking machine with a wire mesh coarseness of 50 mesh, a wire mesh section size of 400 x 400, and a vacuum level of 1500 mm water column in the dewatering section. Retention rate: The value obtained by dividing the weight of the mineral fiberboard after drying and curing by the weight of solid components contained in the aqueous slurry 25. Bending strength: Value measured according to JIS A5907. Compressive strength: 0.5 in the thickness direction of mineral fiberboard
The value obtained by compressing at a speed of mm/min and dividing the stress when the thickness reaches 85% by the area. Nonflammability: Values determined in accordance with British Standard (BS) 476 Part 4 "Testing for nonflammability of materials".

[Table] In addition, sepiolite in Table 1 is based on the fiber length.
Both attapulgite and sepiolite were used in the form of aqueous colloidal dispersions that were softened with a pulper and then fibrillated with a refiner to prevent shortening of the fiber length. In addition, pulp cellulose was used as a gel-like cellulose obtained by beating waste newspaper and having a drainage time of about 400 seconds using a TAPPI Standard Sheet Machine. Furthermore, the polyacrylamide used was a polymer with a molecular weight of about 505. From the results shown in Table 1 above, the freeness and retention rate of the aqueous slurry in Examples are both good, and the mineral fiberboard, which is a paper-formed product made from the aqueous slurry, has good bending strength and nonflammability. It is clear that it has well-balanced physical properties. However, in the case of Comparative Example 1 in which an aqueous slurry that does not contain sepiolite is used, the retention rate in the paper forming process is low because the effect of sepiolite is not obtained, and a mineral fiberboard with satisfactory bending strength cannot be obtained. can't get it. In the case of Comparative Example 2, in which an aqueous slurry containing an excess of sepiolite is used, the physical properties of the obtained mineral fiberboard are good, but the drainage properties of the aqueous slurry are poor, and the mineral fiberboard cannot be manufactured on an industrial scale. Unsuitable for manufacturing. In Comparative Example 5, in which an aqueous slurry containing an excessive amount of pulp cellulose as an organic binder was used, the retention rate in the paper forming process was good, and the obtained mineral fiberboard had excellent bending strength. However, it is not possible to obtain a material that satisfies the requirements in terms of nonflammability. In the case of Comparative Example 6 in which an aqueous slurry containing excess sepiolite and no attapulgite was used, the physical properties of the mineral fiberboard obtained were good in the same manner as in Comparative Example 2, but the aqueous slurry The freeness of the water becomes extremely poor. Furthermore, in the case of Comparative Example 7, which uses an aqueous slurry that contains an appropriate amount of sepiolite but does not contain attapulgite, attapulgite does not function as a binder, so it cannot be used as a mineral that satisfies the bending strength and compressive strength. quality fiberboard cannot be obtained. [Operations and Effects of the Invention] The method for producing mineral fiberboard of the present invention essentially requires 100 parts by weight of mineral fibers, 3 to 25 parts by weight of attapulgite, and 0.1 to 6 parts by weight of sepiolite with a fiber length of 20 μ to 2 mm. is contained as a solid component, and the weight ratio of the attapulgite to sepiolite with a fiber length of 20 μ to 2 mm is 3 to 30:1, and the organic binder is 5 parts by weight or less and the total amount of organic components is 7:1.
A mineral fiberboard is obtained by paper-forming, forming, drying, and curing an aqueous slurry of a mineral fiber composition that is kept to less than parts by weight. A mineral fiberboard is obtained by making full use of the favorable retention effect of sepiolite having a fiber length of 20 μm to 2 mm, which is exerted without causing any adverse effects on paper forming properties. Therefore, in the method for manufacturing a mineral fiberboard of the present invention, a mineral fiberboard having a well-balanced performance such as non-combustibility, fireproof insulation, sound absorption, and mechanical strength can be produced efficiently and inexpensively. The action and effect that can be achieved reliably are achieved.

Claims (1)

[Claims] 1 100 parts by weight of mineral fibers made of rock wool, slag wool, or glass wool, and attapulgite 3
~25 parts by weight and sepiolite with fiber length of 20μ~2mm
0.1 to 6 parts by weight as an essential solid component,
and a mineral in which the weight ratio of attapulgite to sepiolite with a fiber length of 20 μ to 2 mm is 3 to 30:1, and the organic binder is 5 parts by weight or less and the total amount of organic components is suppressed to 7 parts by weight or less. 1. A method for producing a mineral fiberboard, which comprises paper-forming and forming an aqueous slurry of a quality fiber composition, followed by drying and curing.