CN1228507C - Process for preparing non-asbestos copying papers - Google Patents

Abstract

The present invention relates to a method for preparing asbestos-free copy paper, which provides a novel paper making method without asbestos fibers. A paper making machine is adopted to mix water, latex, fibers, stuffing and chemical auxiliary materials into a hydrous dispersed system which gradually dehydrates to form films on a water seepage conveyer, and then the asbestos-free copy paper is made through compressing and drying. The paper has equal tensile strength to asbestos copy paper and can completely replace asbestos paper for manufacturing sealing materials of gaskets, etc.

Description

A kind of do not have asbestos and copy the preparation method who gets paper

Technical field

The invention belongs to field of papermaking, relate in particular to a kind of pad of making and copy the method for getting paper.

Background technology

Generally, encapsulant is mainly used in head gasket and lubricating oil system in the automobile, and what tradition was used is with the sheet material of asbestos fibre as reinforcing material.Asbestos and cellulose fiber peacekeeping filler combine by binding agent, make by using traditional paper making equipment (as fourdrinier machine), so in fact this class material also is called " asbestos paper ".Because asbestos are to the pollution of environment and the harm of human body, all there is strict restriction in each industrial country of the world to producing, selling and uying of asbestos friction material.Therefore need to develop no asbestos seal material with China's characteristic.

Summary of the invention

The invention provides a kind of paper that does not contain asbestos fibre, its tensile strength and asbestos copy that to get paper suitable, copy with this and get the performance that metal wound gasket made of paper has reached the asbestos wound gaskets.

Technical scheme

No asbestos of the present invention are copied and are got paper and made by traditional paper technology, may be summarized to be and adopt papermaking equipment that water, latex, fiber, filler and chemical adjuvant are blended into aqueous dispersion system, in the infiltration stratification of dewatering gradually on the conveyer, then through overcompression, drying.

The suspension dry weight is 3 ‰, and in the moisture papermaking pulp-liquor that the present invention uses, the ratio of each component is as shown in the table:

Table 1 material component

The mass percent of each ingredients constitute solid amount (wt%)

Composition

Scope of application stoichiometric(al)

Kaolin 10～50 10～35

White carbon 10～50 10～35

Sepiolite 10～50 13～30

Mineral wool 15～60 20～50

Rubber cement 3～25 5～15

Cellulose fibre 3～18 6～14

Aromatic polyamide fibre 1～10 1～10

Fortifying fibre is the important component part of fibre reinforced materials, a main heat-resisting and humidification in composition.The physicochemical characteristics of fortifying fibre directly influences the final performance and the product cost of encapsulant.In the slurries, non-asbestos fiber is based on sepiolite and mineral wool fibres.Sepiolite is a kind of fibrous rich magnesium silicate mineral, is the sepiolite of fibrous existence, has great potential specific area, therefore has bigger adsorption capacity, rheological property and catalytic performance; Characteristics such as that mineral wool fiber has is high temperature resistant, Heat stability is good, chemical stability is good, thermal conductivity is low.The OK range of sepiolite is 10～50% in the slurries, and desired proportions is 13～30%, and the OK range of mineral wool is 15～60%, and desired proportions is 20～50%.The slurries that they can obtain suiting with different proportionings.The sepiolite that this experiment is selected for use is α-fiber type shape sepiolite.

Aramid fiber is to have realized suitability for industrialized production at present and obtained the best organic fiber of performance that engineering is used.It has high intensity, good DIMENSIONAL STABILITY, and creep-resistant property is outstanding, and heat resistance is good, and serviceability temperature is-195～204 ℃ continuously, and is all very stable to nearly all chemicals except that a few strong acid, highly basic, but it costs an arm and a leg; Polysulphonamide fiber is a kind of aromatic series fiber that contains sulfuryl, have good heat resistance, corrosion resistance, corrosion resistance and DIMENSIONAL STABILITY, its thermo oxidative aging performance is better than aramid fiber, and price comparison is moderate, be a class comparatively suitable for the asbestos organic fiber.From the cost meter, the aromatic polyamide fibre in the prescription is advisable with 1～10%.

The cellulose fibre that also preferably contains less ratio in the slurries, its good hygroscopicity, softness, surface-activity height, be combined with rubber matrix, the normal temperature strength height, be beneficial to become to open.OK range is 3～18%, and desirable ratio is 6～14%.

In the prescription, elastic binder is that each component organically is bonded together, and particularly filler grain and fortifying fibre is sticked into elastic omentum, and the medium-resistance and the compression recovery performance of material is provided, and can also improve the flexibility of finished paper.Elastic binder preferably uses acrylonitrile-butadiene rubber, especially uses the latex that contains dispersant more convenient.Acrylonitrile-butadiene rubber is the copolymer that is made with emulsion polymerization by butadiene and acrylonitrile.Acrylonitrile-butadiene rubber acrylonitrile mass fraction commonly used is 15%～50%, and existing oil resistivity has better elastic again, and it is insoluble to organic solvents such as gasoline, ether, and oil resistivity is fine.In slurries, to be advisable with 3～25%, desirable ratio is 5～15%.

Filler is for improve material property or the material of the comparatively inertia of adding of reducing cost in matrix material.Filler and compounding ingredient not only are convenient to technological operation, reduce product cost, and can improve the performance of material, make goods satisfy certain technical requirements, for example reach certain density, elasticity, tension stress, withstand voltage and heat resistance.The kaolin that uses in the slurries is a kind of natural minerals, and kaolinic the copying of adapted got sealing plate, and product strength slightly increases, and can alleviate the expansion of the goods of oils, has good heat-resistant.But along with consumption increases, goods hardness increases powerful decline, and elasticity can decrease.Suitable scope is 10～50%, and desirable ratio is 10～35%; The chemical composition of the white carbon black that uses in the slurries is cataloid, and surface area and dispersibility are very big, is the good reinforcing agent of sealed paper.Sealing plate material in that the white carbon black of adapted is made can improve the intensity of goods, acidproof and oil resistance.Suitable ratio is 10～50%, and desirable ratio is 10～35%.

Also will add a certain proportion of surfactant and defoamer in the slurries, activating agent is ten sodium hisbenzene sulfonates, and defoamer is an organic silicone oil.

The density range of the paper of creating is generally at 800～1700kg/m ³

Description of drawings:

Fig. 1 copies the basic technology of following the example of the no asbestos seal material of preparation.

Embodiment

The present invention is preferred two prescriptions can further specify by following example:

The mass percent of each ingredients constitute solid amount (wt%)

Composition

Example 1 example 2

Kaolin 14 14.5

White carbon 17.5 14.5

Sepiolite 14 22

Mineral wool 24.6 22

Rubber cement 12.4 12.5

Cellulose fibre 10.5 11

Aromatic polyamide fibre 7 3.5

At first, about 6 minutes of aramid fiber, cellulose fibre and activating agent slurrying under 6000 rev/mins rotating speed adds kaolin and white carbon, stirs 5 minutes, is blended into slurries, is uniformly dispersed, and adds mineral wool fibres and sepiolite fibre at last, and slurrying 5 minutes.The suspension dilute with water after the slurrying, by stirring at a slow speed, add NBR latex gradually, the water dilution with 5 times of himself capacity continues to stir, and up to forming good turbid liquid, latex absorption is fully.

PH value in the slurries can make it to be reduced to 4.5 by adding paper-makers' alum (aluminum sulfate).The clarification that becomes after stirring stops of supernatant liquid in the mixed liquid, this discrete particles that shows latex all has been deposited on the particulate of fiber and filler.Add entry again, and stirred 3 minutes, the suspension dry weight of Xing Chenging is 3 ‰ at last.

The slurries that make are above added polyacrylamide flocculant and defoamer, on paper machine, make to copy and get paper with conventional method.These slurries are to dewater gradually at the infiltration conveyer belt through paper machine, through overcompression, drying, form to copy and get paper.

The performance of the paper that obtains by these slurries (and do contrast with asbestos paper) as shown in the table:

Key property example 1 example 2 asbestos papers

Density (g/cm ³) 1.68 1.60 1.62

TENSILE STRENGTH horizontal 3.51 3.44 3.68

(MPa) vertical 4.84 4.78 5.08

Compression ratio % 24.19 28.92 8.03

Compression recovery performance

Rebound degree % 15.79 18.42 18.92

Example 1 product density is 1.68g/cm ³, endwise tensile strength is 4.84MPa, and transverse tensile strength is 3.51MPa, and the wound gasket of making is under 80MPa, and compression ratio is 24.19%, the rebound degree after the compression is 15.79%.Example 2 product densities are 1.60g/cm ³, endwise tensile strength is 4.78MPa, and transverse tensile strength is 3.44MPa, and the wound gasket of making is under 80MPa, and compression ratio is 28.9%, the rebound degree after the compression is 18.42%.

The asbestos friction material density that makes simultaneously is 1.62g/cm ³, endwise tensile strength is 5.08MPa, and transverse tensile strength is 3.68MPa, and the wound gasket of making is under 80MPa, and compression ratio is 28.03%, the rebound degree after the compression is 18.92%.

Adopt latexes collecting technology, the sealing material that utilizes the inorfil that do not contain asbestos fibre and organic fiber to mix to strengthen NBR latex to prepare has reached the performance of asbestos material, can substitute asbestos and copy and get paper.

Claims (10)

1, a kind of do not have asbestos and copy the preparation method who gets paper, adopt papermaking equipment that water, latex, fiber, filler and chemical adjuvant are blended into aqueous slurry, the stratification of dewatering gradually on the infiltration conveyer forms through overcompression, drying then, it is characterized in that aqueous slurry comprises following component:

Kaolin 10～50%;

White carbon 10～50%;

Sepiolite fibre 10～50%;

Mineral wool fibres 15～60%;

Rubber cement 5～25%;

Cellulose fibre 3～18%;

Aromatic polyamide fibre 1～10%;

The suspension dry weight is 3 ‰.

2, preparation method described in claim 1 is characterized in that, the rubber cement in its aqueous slurry is a NBR latex.

3, preparation method described in claim 1 is characterized in that, the aromatic polyamide fibre in its aqueous slurry also can replace with fragrant sulfone synthetic fibre pulp.

4, preparation method described in claim 1 is characterized in that, also contains surfactant and defoamer in the aqueous slurry.

5, surfactant described in claim 4 and defoamer is characterized in that, wherein activating agent is ten sodium hisbenzene sulfonates, and defoamer is an organic silicone oil.

6, preparation method described in claim 1 is characterized in that, can add the pH value that paper-makers' alum reduces slurries.

7, preparation method described in claim 1 is characterized in that, can add polyacrylamide flocculant.

8, preparation method described in claim 1 is characterized in that, the stoichiometric(al) of aqueous slurry is:

Kaolin 10～35%;

White carbon 10～35%;

Sepiolite fibre 13～30%;

Mineral wool fibres 20～50%;

Rubber cement 5～15%;

Cellulose fibre 6～14%;

Aromatic polyamide fibre 1～10%;

The suspension dry weight is 3 ‰.

9, preparation method described in claim 1 is characterized in that, the optimization formula of aqueous slurry is:

Kaolin 14%;

White carbon 17.5%;

Sepiolite fibre 14%;

Mineral wool fibres 24.6%;

Rubber cement 12.4%;

Cellulose fibre 10.5%;

Aromatic polyamide fibre 7%;

The suspension dry weight is 3 ‰.

10, preparation method described in claim 1 is characterized in that, the optimization formula of aqueous slurry is:

Kaolin 14.5%;

White carbon 14.5%;

Sepiolite fibre 22%;

Mineral wool fibres 22%;

Rubber cement 12.5%;

Cellulose fibre 11%;

Aromatic polyamide fibre 3.5%;

The suspension dry weight is 3 ‰.

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