JPH03241090A - Fiber-vermiculite composite sheet and manufacture thereof - Google Patents

Abstract

PURPOSE: To produce a fiber/vermiculite composite sheet useful as a flame- propagation barrier, etc., using a continuous papermaking machine by delaminating vermiculite only by mechanical shearing force, dispersing the delaminated vermiculite in water together with a fiber material and agglomerating the dispersion. CONSTITUTION: A shearing action is applied to an aqueous slurry of a vermiculite ore until a dispersion containing vermiculite lamella having a dimension of <=200 μm is obtained to effect the delamination of vermiculite only by mechanical shearing force. The objective sheet is produced by dispersing 20-99 wt.% (in terms of solid weight) of the mechanically delaminated vermiculite and 1-80 wt.% (in terms of solid weight) of at least one kind of fiber material (preferably a combination of glass fiber and wood pulp) in water and adding 0.1-10 wt.% (based on the vermiculite) of at least one kind of agglomeration agent to effect the agglomeration of the dispersion.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a paper manufacturing method for manufacturing a composite sheet material containing inorganic vermiculite.

(Prior Art) A sheet material is produced by coagulating and dewatering a mixture of various organic, IR-free fibers and vermiculite which has been chemically treated to cause expansion of bar-curite lamellae before applying shear force. A method for producing is disclosed. For example, US Pat. No. 3,434,917 describes a method for converting vermiculite ore into pulp suitable for forming into sheets by conventional paper manufacturing methods. The vermiculite ore is treated with a sodium chloride and lithium salt solution prior to shearing, and asbestos or cellulose is added to the vermiculite suspension prior to flocculation with potassium hydroxide or hydrochloric acid. U.S. Pat. No. 3,654,073 discloses a method for making non-combustible paper from a mixture comprising asbestos, glass fibers, lithium-exchanged vermiculite, and latex resin using an inorganic flocculant. Water-resistant and heat-resistant agglomerated inorganic materials are disclosed in U.S. Patent Nos. 4 and 7.
No. 07,298. The material includes an expanded layered silicate gel made from vermiculite and/or mica, optionally mixed with fibers. Aggregated inorganic materials containing a binder and expanded layered silicate gels are disclosed in U.S. Pat. No. 4,762,64.
It is disclosed in the specification of No. 3. The material may optionally contain a fibrous material selected from silicon fibers, boron fibers, carbon fibers, ceramic fibers, glass fibers, and metal fibers. However, materials made from chemically delaminated vermiculite are difficult to drain and form continuous sheets using standard paper making equipment.

U.S. Pat. No. 4,801,403 discloses a method for making an aqueous dispersion of mechanically delaminated vermiculite ore particles. This method of producing vermiculite dispersions is less costly and less time consuming than chemical delamination, because it involves the steps of treating vermiculite ore with various salt solutions to cause cation exchange; This is because it does not include the steps of washing away excess salt and expanding the vermiculite ore before shearing. The method further eliminates the cost of maintaining high processing temperatures, typically 500°C or higher (required for thermal exfoliation, another known method of expanding vermiculite prior to mechanical shearing). . Further, U.S. Pat. No. 4,801,403 describes a method for producing solid particles by depositing a dispersion of mechanically delaminated vermiculite lamellae on a surface and removing water from the vermiculite. Disclosed. No fibers are included in the dispersion, nor is there a method disclosed for producing composite sheets from such a dispersion using paper manufacturing techniques.

It has been shown that mechanically delaminated vermiculite is particularly suitable for manufacturing composite sheets using continuous paper manufacturing techniques.0 Dispersions of mechanically delaminated vermiculite are It has a high water drainage rate and a high vermiculite retention rate. Therefore, manufacturing using conventional paper manufacturing equipment is facilitated.

A composite sheet is produced by delaminating vermiculite, dispersing the vermiculite and fibrous material in water, adding a flocculant to flocculate the dispersion, and dewatering the flocculated dispersion to form a sheet. The method of the present invention comprises (1) delaminating vermiculite only by mechanical shearing by applying a shearing action to an aqueous slurry of vermiculite until a dispersion containing vermiculite lamellae having a size of 200 microns or less is obtained; ;(
2) dispersing in water 20-99% mechanically delaminated vermiculite by weight of solids and 1-80% by weight of solids of at least one fibrous material; and (3) The dispersion is flocculated by adding 0.1 to 10% of at least one flocculant based on the weight of bargogyu nirite.

“Vermiculite°” as used herein.

means any material known mineralogically or commercially as vermiculite, which contains as a constituent a layer of vermiculite (e.g. hydrobiotite vermiculite or chlorite vermiculite), and in the case of vermiculite. Mixed layer type minerals (layered silicates) that can be delaminated in the same way as
Nothing consisting of all or most vermiculite, including
Contains matter.

In accordance with the present invention, shearing forces are applied to the aqueous slurry of burculite ore using suitable shearing equipment known in the art (e.g., cowles blades, roll mills, colloid mills, or ball-type mills). By applying this, the vermiculite ore particles are delaminated to obtain a dispersion containing vermiculite lamellae. Shearing forces can also be imparted by suitable vibratory treatments (eg, ultrasonic vibrating of an aqueous slurry of minerals). Vermiculite ore has not traditionally been treated with heat or chemical expansion agents (stripping agents) to expand the vermiculite.

The aqueous slurry of unexpanded vermiculite ore subjected to shearing according to the present invention preferably ranges from IO to 50%
more preferably 0 to 35% by weight of solids, and most preferably 20 to 35% by weight of solids.

The weight percent solids content in a slurry is defined as the viscosity of the slurry,
It is limited by factors such as the type of means for applying the shearing action and the viscosity of the resulting vermiculite lamellar dispersion.

The vermiculite lamella obtained according to the present invention is usually 200 microns or less (preferably 50 microns or less)
It has a particle size of Such particles generally have an aspect ratio (ie, length or width divided by thickness) of at least 10. The shearing action should be applied for the minimum amount of time necessary to obtain a dispersion containing particles of the desired size. If desired, undesired particles (eg, particles with a size of 50 microns or more) can be removed by conventional physical separation methods after shearing. These separation methods include sedimentation separation, filtration separation, sieve separation,
Separation methods include, but are not limited to, centrifugation and cyclone separation.

According to another aspect of the invention, a dispersant that does not swell the vermiculite, or a combination of such dispersants, is added to the aqueous slurry of vermiculite before, during, after shearing, or a combination thereof. can be added. Slurries can be sheared at higher solids contents by adding dispersants. Adding a dispersant reduces the viscosity of the slurry without exfoliating (swelling) the vermiculite lamellae. A range of other suitable compounds, both inorganic and organic compounds, can be used as dispersants (e.g. alkali metal salts of polyphosphoric acids, such as tetrasodium pyrophosphate, and derivatives of polyamines, such as polyethyleneimine). A dispersant is disclosed in U.S. Patent No. 4,80.
No. 1,403.

The amount of dispersant necessary to control the viscosity of an aqueous slurry of vermiculite or a lamellar dispersion of vermiculite obtained by applying a shearing action to the slurry depends on the temperature, the pH of the slurry or dispersion, and the amount of slurried vermiculite. It depends on various process variables, such as the extent to which the ore is converted to vermiculite lamellae, the type of shearing equipment used, and the solids level of the aqueous vermiculite slurry or dispersion.

After the delamination process, 20-9% based on the weight of the solid
9% (preferably 60-99%) mechanically delaminated vermiculite and 1-80% by weight of solids
% (preferably 1-40%) of one or more fibrous materials are dispersed in water. The fiber material is organic fiber or #l-free.
It may be one or more types of fibers or a mixture thereof. Suitable inorganic fibers include, but are not limited to, silicon fibers, boron fibers, ceramic fibers, glass fibers, metal fibers, and mineral fibers. Suitable organic fibers include cellulose fibers, polyester fibers, polyamide fibers, etc. , polyolefin fiber, polyimide fiber, polyacrylate fiber, carbon fiber, polyamide fiber ξl'Mli1
1. Examples include, but are not limited to, polyether-based fibers and phenolic fibers.

The type of fiber selected will depend on the intended use of the final product.

Wet paper strength enhancer, dry paper strength enhancer, sizing agent, binder,
Additives such as adhesives, flame retardants, and other additives known in the paper making industry may also be present in the dispersion.

0.1-10% (based on the weight of vermiculite)
A flocculant or a combination of flocculants (preferably from 0.7 to 4%) is added to the vermiculite and fiber dispersion to flocculate the dispersion. The flocculant can be selected from any flocculant known to the paper making industry. Such flocculants include inorganic acids, monovalent bases such as potassium hydroxide, organic acids, inorganic anions such as phosphates and sulfates, high molecular weight cationic polymer electrolytes, and high molecular weight Examples include, but are not limited to, anionic polymers.

A combination of anionic acrylamide copolymer and cationic polyamine is preferred; the flocculant is retained in the final sheet.

The flocculated dispersion is deposited on a conventional paper making screen and dewatered to form a composite sheet. Using a continuous dehydration step, the product can be obtained in roll form. After the dewatering step, the sheet is dried by any suitable method known to those skilled in the art.

The first pass retention of vermiculite in this sheet is usually 5
It is 0% or more, preferably 80% or more. Such sheets are in the form of paper [generally 5-30 mils (0.1-0.
．． 8+am) or in the form of paperboard (generally 1/16 to 1/2
It can also be obtained with a thickness of 3cI11). If necessary, the sheet or board can be shaped before drying to obtain a three-dimensional structure by techniques known to those skilled in the art (eg corrugation techniques).

The composite sheet material obtained according to the manufacturing method of the present invention can be used for a wide range of applications. It can be used as a flame propagation barrier by lamination to or to high performance plastics, such as those used in interior aircraft panels. If the composite sheet contains heat-resistant fibers, the composite sheet can be used as a material for gaskets. The use of thermoplastic fibers such as polyolefin fibers or polyester fibers results in thermoformable sheets. It is possible to obtain an IT sheet for shielding electromagnetic waves by using conductive fibers such as carbon fibers and metal fibers.

Carborundum Stone
Delaminated vermiculite was prepared by shearing a mixture of 36 wt% grade 4 raw ore and water for 2 hours using a 6 inch (15,2 cm) colloid mill equipped with a Particles larger than 53 microns were removed by sieving.The Bar 5 Curite dispersion was coated with type 5691 glass fibers (Omens-Corntng Fiberglass Corporation).
Glass fiber with a diameter of 7.5 microns and a length of 178 yen (3.2 mm), commercially available from S.S. Corp.]
, and 250 Canadian Standard Freeness.
ess; C3F) was double-disc purified (do
(refined) unbleached kraft pulp was mixed. The solids concentration of the stock solution was 0.5% and the weight ratio of vermiculite/glass fiber/wood pulp was 88/6/6. Kimen (KYmon ENER)
557) 1 cationic resin (Vercules Inc.) and RETENll 523P anionic acrylamide copolymer (Vercules Inc.) as flocculants, flat wire Fourdrinier
) The paper machine produces the first Kurenksu box (m
ix box) and a fan pump. The respective levels were 2.5% and 1.2% based on the weight of verpoculite. 30
A continuous roll of 00 ft2 was obtained.

The basic weight of this seat is 2391bs/3000ft2 (
0.4 kg/m2) and has a thickness of 15.4 mils (0.4 kg/m2).
4 mm).

Real M No-pull and Wood Handsheet Machine (N
oble and wood handsheet a
+achine) was used to produce a handsheet. The burculite was delaminated by shearing the raw ore and water mixture as described in Example 1, and particles larger than 53 microns were removed by sieving. 166
6.7g of vermiculite dispersion (Total Solid
'-7,3%), 18.0g glass, and 360g
1:1 blend of hardwood pulp and softwood pulp refined to 258C3F (total solids - 2.5%)
A stock solution for paper manufacturing was prepared by mixing and diluting to 1802 with tap water. The weight ratio of vermiculite/glass/wood pulp was 82/12/6. The bar also contains 2% quinone 12064 based on the weight of Curite.
The above stock solution of 101! was flocculated using a cationic resin (Vercules Incophorated) and 1.0% Retin' 523P anionic acrylamide copolymer (Vercules Incophorated);
The water was drained through a 0 mesh screen. The retention rate for the first time was 97%.

Draining was performed in 10 seconds or less. Average tensile strength is 181
b/fJ (3.2 kg/cm) width, and the average tear strength was 314 g/sheet.

Handsheets were made using a Fumasu Makarushi Nople and Wood Handsheet Machine. The vermiculite was delaminated by shearing the raw ore and water mixture as described in Example 1, and particles larger than 53 microns were removed by sieving. 1768.29 g of delaminated vermiculite dispersion (total solids (TS) = 7
．． 3%) and 780 g of a 1:1 blend of hardwood pulp and softwood pulp (total solids = 2.5%) refined to 260C5F, as described in Example 2. was created. The vermiculite/wood pulp weight ratio was 85/15. The stock solution was used in Example 2.
The mixture was flocculated as described in 2003 and drained through a 100-mesh screen. Twenty handsheets were produced. The average tensile strength of the handsheet is 14.81b/?
(2,6 kg/cI11) width, and the average tear strength is 1
It was 39g/sheet.

Handsheets were made using a Nople and Wood handsheet machine. The vermiculite was delaminated by shearing the raw ore and water mixture as described in Example 1.

Particles larger than 53-cm were removed by sieving. Vermiculite dispersion and type 5691 glass fibers (available from Owens-Corning Fiberglass Corporation; 7.5 micron diameter, 1/8 length)
::'(3,2 open)], a stock solution for paper production was prepared as described in Example 2, such that the weight ratio of vermiculite solid to glass solid was 87/13. The stock solution was then agglomerated as described in Example 2. This 1.51 portion was drained through a 100 mesh screen to produce 12 handsheets. The average tensile strength of the handsheet is 13.21b
/f' (2.4 kg/cm) width, and the average tear strength was 210 g/sheet.

A total solids 40% mixture of water and grade 4 vermiculite ore is prepared with 4% chimene based on the weight of the vermiculite, present in minutes with 2064 cationic resin (Vercules Inc.). Delaminated vermiculite was prepared by shearing for 27 hours under the condition of 6 inches (15,2 cm) with carborundum 71'! stones.
A colloid mill was used.

Particles larger than 53 microns were removed by sieving.

The final yield of material with a particle size of less than 53 straw tons was 54% and the final total solids 7i'' was 17%. 500 kg I) Standard hard water with a total solids of 84% Vermiculite (87k)
g, 17.5χ total solid) and 2.73 kg
Type F-110 glass fiber (Manville Corp.) was added;
It was then diluted to 17,503 g with standard hard water to obtain a verculite/glass weight ratio of 87/13.

Standard hard water is 50pp+m 7. It has IL/potassium and is CaCO5 and Te1o.

It has a hardness of ρp11. Final pH was 7.2.

A continuous 275 ft.
A roll of (82,5+n) was produced. agglomerating the substrate using 0.6% Retin' 523P anionic acrylazide copolymer (Vercules Inc.) based on the weight of vermiculite;
Next, the basic weight of the dehydrated 0 sheet is 1201b73
000 ft" (0.2 kg/m") and the thickness was 8.4 kur (0.2 m-).

In this example, we demonstrate the drainage rate of sheets made from chemically delaminated vermiculite, thermally delaminated vermiculite, and mechanically delaminated vermiculite (all mixed with glass fibers). and vermiculite retention rate %. For comparison, two types of chemically exfoliated vermiculite were used. One type is lithium-exchanged vermiculite, and the other is propylammonium chloride-exchanged vermiculite (both prepared and sheared according to methods known to abutting technicians). 20 wt. Shearing treatment was applied over the course of the test.

Curite by mechanical delamination is prepared by preparing a mixture of 36% by weight grade 4 unprocessed ore and water using a 6 f' (15,2c+n) colloid mill equipped with a carporundum stone. Made by shearing for 5 hours. Particles larger than 53 microns were removed by sieving.

Dynamic Drainage Test
Te5t) jar tachique
A comparison was made using the .

Draining jar data have been found to correlate with the processability of paper stock solutions for industrial scale paper machines [Davison 11;
'Mechanism of Fine' by W.
ParticleRetention in P
apar)”+ 1982 TAPPI Pap
ermakersCoaferenca Proce
adings, TAPPE Press+ A
t1anta.

G.A., 1982. pp, 153-164” and “Some Effects” by Davison R.W.
of Aqueous Environa+en
onFine Particle Retent
ion in Paper + 1985 TAP
MPapermakers Conference
Proceedings, TAPPIPress, A
t1anta, GA, 1985+ pp, 171-
181], type FILO1/8:'(
3.2) Mix 50 ml of a 0.4% dispersion of glass fibers (commercially available from Manville Corporation) and 100 ml of a 1% dispersion of vermiculite in a 600-ml beaker, stir and add 500 ml ! A barculite/glass fiber composite sheet was prepared by diluting with distilled water. A 1% aqueous solution of Kymen" 2064 cationic resin (Vercules Inc.) at 2% by weight based on the weight of the vermiculite was added to the vermiculite/glass fiber dispersion.

After 1 minute of stirring, a 0.5% aqueous solution of Retin' 523P anionic acrylamide copolymer (Vercules Inc.), 1% by weight based on the weight of vermiculite, was added and the dispersion was stirred for another 1 minute. The flocculated dispersion was then transferred to a draining jar and drained through a 10f) mesh support screen. The time for water to drain through the screen was recorded.
+) sheets were removed, dried, and weighed. Assuming that 100% of all solids are retained, the resulting sheet will have &ll or burculite 1. oo
g, glass fiber 0.20 g, and flocculant 0.03 g. , the test results are shown in Table 1. As can be seen from the table, sheets made using mechanically delaminated vermiculite drain water more quickly and have a higher retention rate of vermiculite than sheets made using other vermiculites. This type of performance is required for the continuous production of paper using industrial scale machinery.

Sheets were made from mechanically delaminated vermiculite as described in Example 6, except that an equal amount of carbon fiber was used in place of glass fiber in the second example. The water draining time is 8 seconds, and the vermiculite retention rate in the sheet is 86
%Met.

Sheets were made from mechanically delaminated vermiculite as described in Example 6, except that an equal amount of Kepler 8 Boriad fibers (DuPont) was used in place of the backing exposed glass fibers. The water draining time was 13 seconds, and the retention rate of burculite in the sheet was 94.5%.

Pulpex (PU) is used instead of the main glass fiber alone.
Sheets were made from mechanically delaminated vermiculite as described in Example 6, except that a mixture of LPEXR)EA synthetic pulp (Vercules Inc.) and glass fibers was used. The water drainage time was 8.5 seconds, and the vermiculite retention rate in the sheet was 88%.

(4 other people)

Claims (1)

Claims: 1. (1) 20 to 99%, by weight of solids, of vermiculite delaminated by mechanical shear alone; (2) 1 to 80%, by weight of solids, of at least 1 and (3) 0.1 to 10% of at least one flocculant based on the weight of the vermiculite. 2. The composite sheet according to claim 1, further characterized in that the fibrous material is a combination of glass fiber and wood pulp. 3. The composite sheet according to claim 1 or 2, further characterized in that the flocculant is a combination of a cationic polyamine and an anionic acrylamide copolymer. 4. (i) delaminating the vermiculite; (ii) dispersing the vermiculite and fiber material in water; (iii) adding a flocculant to flocculate the dispersion; and (iv) flocculating and dispersing the vermiculite. A method of manufacturing a composite sheet by: (1) forming an aqueous slurry of vermiculite ore until a dispersion containing vermiculite lamellae having a size of 200 microns or less is obtained; (2) 20 to 99% of the mechanically delaminated vermiculite based on the weight of the solid; and 1 based on the weight of the solid; and (3) dispersing ˜80% of at least one fibrous material in water; and (3) 0 based on the weight of said vermiculite.
．． The method for producing a composite sheet, characterized in that the dispersion is agglomerated by adding 1 to 10% of at least one type of aggregating agent. 5. The manufacturing method according to claim 4, further comprising removing particles of 50 microns or more by physical means after step (1). 6. The manufacturing method according to claim 4 or 5, further characterized in that the mechanical delamination step is carried out in the presence of a dispersant that does not swell the vermiculite. 7. Claims 4 to 6 further characterized in that the dewatering step is carried out in a continuous manner to obtain the composite sheet in the form of a roll.
The manufacturing method according to any one of the above. 8. The manufacturing method according to any one of claims 4 to 7, further characterized in that the fibrous material is a combination of wood pulp and glass fibers. 9. The method according to any one of claims 4 to 8, further characterized in that the flocculant is a combination of a cationic polyamine and an anionic acrylamide copolymer.