CN112388803A

CN112388803A - Method for manufacturing disposable composite veneer fireproof plate

Info

Publication number: CN112388803A
Application number: CN202011162797.7A
Authority: CN
Inventors: 张美娟; 范明
Original assignee: Zhangjiagang Shenggang Juge Technology Co ltd
Current assignee: Zhangjiagang Shenggang Juge Technology Co ltd
Priority date: 2020-10-27
Filing date: 2020-10-27
Publication date: 2021-02-23

Abstract

The invention discloses a method for manufacturing a disposable composite veneer fireproof plate, which relates to the technical field of fireproof plates and comprises the following steps: heating the facing material, and extruding the facing material; manufacturing a facing: placing the interwoven fabric on the back of the facing material, and performing shaping rolling through rolling equipment; preparing slurry: mixing the slurry materials together, and uniformly stirring to obtain slurry; preparing a substrate: placing the pulp into a pulp hopper, adjusting the gap of a roller, and uniformly paving the pulp on the veneer by the pulp passing through the roller; preparing a medium material: mixing the medium materials together, and uniformly stirring; maintaining for the first time: uniformly paving the medium materials on the substrate through a medium hopper, and then maintaining; demolding; and (5) second maintenance: and curing again. The invention achieves the bonding effect by mutual permeation between the slurry and the facing, and after solidification and setting, the facing is bonded with the slurry, thereby saving the procedure of adding the adhesive into the slurry, reducing the process flow and improving the production efficiency.

Description

Method for manufacturing disposable composite veneer fireproof plate

Technical Field

The invention relates to the technical field of fireproof plates, in particular to a manufacturing method of a disposable composite veneer fireproof plate.

Background

The fireproof plate is a building plate with fireproof property, and is widely applied to the fields of indoor decoration, furniture, kitchen table plates, house outer walls and the like. The conventional composite-faced fireproof board is roughly divided into cold pressing and hot pressing processes by using fireproof materials such as magnesium oxide, magnesium carbonate or reinforced fibers. The cold pressing process is to coat the back layer and the surface of the fireproof plate with adhesive, and then to form the fireproof plate through cold pressing, curing and shaping. The hot pressing process is to heat and solidify the fireproof board surface and the facing by using a thermosetting adhesive.

However, both of the above processes take a lot of manpower and costs of adhesives, and some adhesives contain a lot of organic substances harmful to human body and are healthy to workers.

Therefore, it is desirable to provide a new method for manufacturing a composite-faced fireproof plate, so that the composite-faced fireproof plate can be manufactured more conveniently and more environmentally friendly.

Disclosure of Invention

The invention aims to provide a method for manufacturing a disposable composite veneer fireproof plate, which can reduce the use of adhesives.

To achieve the above object, the present invention has the following constitutions (1) to (21):

(1) a method for manufacturing a disposable composite veneer fireproof plate comprises the following steps:

heating: heating the facing material to make the facing material be in liquid state,

extruding: extruding the facing material to obtain a softened facing material;

manufacturing a facing: placing the interwoven fabric on the back of the softened facing material, and performing shaping and rolling through rolling equipment to obtain a required facing;

preparing slurry: uniformly mixing the slurry materials together, and uniformly stirring to obtain slurry;

preparing a substrate: placing the slurry into a slurry discharging hopper in a production line, adjusting a roller gap in the slurry discharging hopper, enabling the slurry to pass through a roller to obtain uniformly laid slurry, and uniformly laying the slurry on a facing to obtain a substrate;

preparing a medium material: uniformly mixing the medium materials together, and uniformly stirring to obtain a medium material;

maintaining for the first time: uniformly paving the medium materials on the substrate through a medium hopper, and then maintaining;

demolding;

and (5) second maintenance: and maintaining again to obtain the disposable composite veneer fireproof plate.

(2) Furthermore, in the heating process, the facing material accounts for 100 parts by weight.

(3) Further, in the heating process, the facing material is PP or PVC or melamine paper.

(4) Further, for heating, the facing material is heated to 150 ℃.

(5) Further, in the case of extrusion, the facing material is roll-formed by an embossing roll to obtain a softened facing material having a thickness of 0.3 to 0.5 mm.

(6) Further, for the pressing, an adhesive is applied to the back surface of the medium softening finishing material.

(7) Further, for extrusion, the adhesive is in the form of a paste.

(8) Further, in the extrusion, the adhesive is applied to the back surface of the medium softening finishing material, and the temperature of the softening finishing material is 50-60 ℃.

(9) Further, for extrusion, the interwoven fabric is woven from glass filaments.

(10) Further, in the preparation of the slurry, the slurry material comprises the following components in parts by mass: 50 parts of magnesium oxide, 50-60 parts of magnesium chloride solution and 5-10 parts of PP emulsion.

(11) Further, in the preparation of the slurry, the slurry material comprises the following components in parts by mass: 40-50 parts of gypsum powder and 30-40 parts of water.

(12) Further, in the preparation of the slurry, the slurry material comprises the following components in parts by mass: 40-50 parts of cement and 30-40 parts of water.

(13) Further, in the preparation of the slurry, the slurry material is uniformly stirred at the speed of 50-60r/min and is stirred for 3 minutes to obtain the slurry.

(14) Further, in the preparation of the substrate, the gap between rollers is adjusted to 6.2-6.6mm, and the slurry passes through the rollers to obtain the uniformly laid slurry with the thickness of 0.2-0.6 mm.

(15) Further, in the preparation of the medium material, the medium material comprises the following components in parts by mass: 50 parts of magnesium oxide, 50-60 parts of magnesium chloride solution, 10-15 parts of wood fiber, 5-10 parts of fly ash and 5-10 parts of talcum powder.

(16) Further, in the preparation of the medium material, the medium material comprises the following components in parts by mass: 40-50 parts of gypsum powder, 30-40 parts of water, 5-10 parts of lightweight aggregate and 5-10 parts of wood fiber.

(17) Further, in the preparation of the medium material, the medium material comprises the following components in parts by mass: 40-50 parts of cement, 30-40 parts of water, 5-10 parts of lightweight aggregate and 5-10 parts of wood fiber.

(18) Further, in the preparation of the medium material, the medium material is uniformly stirred at the speed of 50-60r/min and is stirred for 3 minutes to obtain the medium material.

(19) Furthermore, in the first curing, the gap between the middle hopper and the roller is adjusted, and the proper disposable composite veneer fireproof plate with the thickness of 6-18mm can be obtained according to the requirement of a customer.

(20) Further, in the first curing, curing is carried out for 8-12 hours.

(21) Furthermore, in the second curing, curing is required for 5-10 days.

The invention has the beneficial effects that:

1. through directly heating the facing material on the production line and then placing the interwoven fabric, the post-processing process can be effectively reduced, meanwhile, the facing material has a certain temperature after being processed, the interwoven fabric can be effectively reduced in the use of the adhesive after being placed on the back of the facing material, the interwoven fabric can be closely attached to the facing material after the facing material is cooled, so that the problem of secondary glue coating is reduced, and then the interwoven fabric is mixed with the slurry and the medium material through the processes of placing the slurry and the medium material on the interwoven fabric, such as maintenance and the like to form a complete whole, so that the interwoven fabric is bonded together, the use of the adhesive is effectively reduced, the production cost is reduced, meanwhile, the use of the adhesive can also ensure the safety of workers, the production of the composite facing material is more convenient and rapid, Is environment-friendly.

Detailed Description

In order to make the objects and technical solutions of the present invention clear and fully described, and the advantages thereof more apparent, embodiments of the present invention are described in further detail below. It is to be understood that the specific embodiments described herein are illustrative of some, but not all embodiments of the invention, and are not to be construed as limiting the embodiments of the invention, and that all other embodiments, which can be derived by one of ordinary skill in the art without making any inventive step, are within the scope of the invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "inner", "outer", "top", "bottom", "side", "vertical", "horizontal", and the like indicate orientations or positional relationships only for the convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "a," "an," "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

For the purposes of simplicity and explanation, the principles of the embodiments are described by referring mainly to examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. But it is obvious. To one of ordinary skill in the art, the embodiments may be practiced without limitation to these specific details. In some instances, well-known pipe processing methods and structures have not been described in detail to avoid unnecessarily obscuring the embodiments. In addition, all embodiments may be used in combination with each other.

The first embodiment is as follows:

taking 100 parts by weight of PP, heating the PP to 150 ℃, wherein the PP is in a liquid state, and then extruding the PP through a knurling wheel to obtain softened PP with the thickness of 0.3-0.5 mm.

When the temperature of softened PP reaches 50-60 ℃, coating adhesive on the back surface of the softened PP, wherein the adhesive is pasty, then placing interwoven fabric on the back surface of the softened PP, the interwoven fabric is formed by weaving 10-10 meshes of glass filaments, the thinner the glass filament number is, the higher the bonding fastness is, and the bonding degree of the glass filaments exceeding 10-10 meshes cannot support the facing material. And then, carrying out shaping and rolling by using rolling equipment to obtain the PP facing.

And mixing and stirring 50 parts by weight of magnesium oxide, 50-60 parts by weight of magnesium chloride solution and 5-10 parts by weight of PP emulsion, uniformly stirring at 50-60r/min, and stirring for 3 minutes to obtain the slurry.

And putting the prepared slurry into a slurry placing hopper in a production line, adjusting the gap of a roller in the slurry placing hopper, adjusting the gap of the roller to be 6.2-6.6mm, passing the slurry through the roller to obtain uniformly laid slurry with the thickness of 0.2-0.6mm, and uniformly laying the slurry on the PP facing to obtain the substrate.

Taking 50 parts by weight of magnesium oxide, 50-60 parts by weight of magnesium chloride solution, 10-15 parts by weight of wood fiber, 5-10 parts by weight of fly ash and 5-10 parts by weight of talcum powder, mixing and stirring, uniformly stirring at 50-60r/min, and stirring for 3 minutes to obtain the intermediate material.

Putting the prepared middle material into a middle hopper in a production line, uniformly paving the middle material on a base plate, adjusting the gap between rollers of the middle hopper to obtain the middle material with the thickness of 6-18mm according to the requirement of a customer, then maintaining for 8-12 hours, and demoulding to obtain the disposable composite veneer fireproof plate.

And after demolding is finished, performing secondary curing for 5-10 days to obtain the disposable composite veneer fireproof plate.

Example two:

Mixing and stirring 50 parts by weight of gypsum powder, 30-40 parts by weight of water, 5-10 parts by weight of lightweight aggregate and 5-10 parts by weight of wood fiber, uniformly stirring at 50-60r/min, and stirring for 3 minutes to obtain the intermediate material.

Example three:

Taking 50 parts by weight of cement, 30-40 parts by weight of water, 5-10 parts by weight of lightweight aggregate and 5-10 parts by weight of wood fiber, mixing and stirring, uniformly stirring at 50-60r/min, and stirring for 3 minutes to obtain the medium material.

Example four:

Mixing and stirring 40-50 parts by weight of gypsum powder and 30-40 parts by weight of water, uniformly stirring at 50-60r/min, and stirring for 3 minutes to obtain slurry.

Example five:

Example six:

Example seven:

Mixing and stirring 40-50 parts of cement and 30-40 parts of water, uniformly stirring at 50-60r/min, and stirring for 3 minutes to obtain the slurry.

Example eight:

Example nine:

Comparative example one:

taking 100 parts by weight of PP, heating the PP, and then carrying out setting rolling through rolling equipment to obtain the PP facing.

An adhesive is applied to the back of the PP facing.

Putting the prepared slurry into a slurry placing hopper in a production line, adjusting the gap of a roller in the slurry placing hopper, adjusting the gap of the roller to be 6.2-6.6mm, passing the slurry through the roller to obtain uniformly laid slurry with the thickness of 0.2-0.6mm, uniformly laying the slurry on a PP facing, heating the surface of the fireproof plate and the facing, and curing and shaping to obtain the base plate.

Comparative example two:

An adhesive is applied to the back of the PP facing.

And putting the prepared slurry into a slurry placing hopper in a production line, adjusting the gap of a roller in the slurry placing hopper, adjusting the gap of the roller to be 6.2-6.6mm, passing the slurry through the roller to obtain uniformly laid slurry with the thickness of 0.2-0.6mm, uniformly laying the slurry on the PP facing, carrying out cold pressing on the PP facing, and then curing and shaping to obtain the substrate.

Example ten:

100 parts by weight of PVC is taken, then heated to 150 ℃, the PVC is in a liquid state, and then extruded by an embossing wheel to obtain 0.3-0.5mm of softened PVC.

When the temperature of the softened PVC reaches 50-60 ℃, coating an adhesive on the back surface of the softened PVC, wherein the adhesive is pasty, then placing an interwoven fabric on the back surface of the softened PVC, the interwoven fabric is formed by weaving 10-mesh glass filaments, the thinner the glass filament number is, the higher the bonding fastness is, and the bonding degree of the glass filaments exceeding 10-mesh cannot support the facing material. And then, carrying out shaping and rolling through rolling equipment to obtain the PVC veneer.

And putting the prepared slurry into a slurry placing hopper in a production line, adjusting the gap of a roller in the slurry placing hopper, adjusting the gap of the roller to be 6.2-6.6mm, passing the slurry through the roller to obtain uniformly laid slurry with the thickness of 0.2-0.6mm, and uniformly laying the slurry on the PVC veneer to obtain the substrate.

Example eleven:

Example twelve:

Example thirteen:

Example fourteen:

Example fifteen:

Example sixteen:

Example seventeen:

Example eighteen:

Comparative example three:

100 parts by weight of PVC is taken, then the PVC is heated, and then the PVC veneer is obtained after the PVC is shaped and rolled by rolling equipment.

An adhesive is applied to the back of the PVC facing.

Putting the prepared slurry into a slurry placing hopper in a production line, adjusting the gap of a roller in the slurry placing hopper, adjusting the gap of the roller to be 6.2-6.6mm, passing the slurry through the roller to obtain uniformly laid slurry with the thickness of 0.2-0.6mm, uniformly laying the slurry on a PVC veneer, heating the surface of the fireproof plate and the veneer, and curing and shaping to obtain the substrate.

Comparative example four:

An adhesive is applied to the back of the PVC facing.

Putting the prepared slurry into a slurry placing hopper in a production line, adjusting the gap of a roller in the slurry placing hopper, adjusting the gap of the roller to be 6.2-6.6mm, passing the slurry through the roller to obtain uniformly laid slurry with the thickness of 0.2-0.6mm, uniformly laying the slurry on a PVC veneer, carrying out cold pressing on the PVC veneer, and then curing and shaping to obtain the substrate.

Putting the prepared middle material into a middle hopper in a production line, uniformly paving the middle material on a base plate, adjusting the gap between rollers of the middle hopper to obtain the middle material with the thickness of 6-18mm according to the requirement of a customer, then maintaining for 8-12 hours, and demoulding to obtain the disposable composite veneer fireproof plate. And after demolding is finished, performing secondary curing for 5-10 days to obtain the disposable composite veneer fireproof plate.

Example nineteenth:

100 parts by weight of melamine paper is taken, then the melamine paper is heated to 150 ℃, at the moment, the melamine paper is in a liquid state, and then the melamine paper is extruded by an embossing wheel, so that the softened melamine paper with the thickness of 0.3-0.5mm is obtained.

When the temperature of the softened melamine paper reaches 50-60 ℃, coating an adhesive on the back surface of the softened melamine paper, wherein the adhesive is in a paste shape, then placing an interwoven fabric on the back surface of the softened melamine paper, the interwoven fabric is formed by weaving 10-mesh glass fibers, the thinner the glass fibers, the higher the bonding fastness, and the bonding degree of the glass fibers exceeding 10-mesh cannot support the facing material. And then, sizing and rolling are carried out through rolling equipment to obtain the melamine paper veneer.

And putting the prepared slurry into a slurry discharging hopper in a production line, adjusting the gap of a roller in the slurry discharging hopper, adjusting the gap of the roller to be 6.2-6.6mm, passing the slurry through the roller to obtain uniformly laid slurry with the thickness of 0.2-0.6mm, and uniformly laying the slurry on the melamine paper veneer to obtain the substrate.

Example twenty:

Example twenty one:

Example twenty two:

Example twenty three:

Example twenty-four:

Example twenty-five:

Example twenty-six:

Example twenty-seven:

Comparative example five:

taking 100 parts by weight of melamine paper, heating the melamine paper, and then carrying out sizing and rolling through rolling equipment to obtain the melamine paper veneer.

An adhesive is applied to the back of the melamine paper facing.

Putting the prepared slurry into a slurry placing hopper in a production line, adjusting the gap of a roller in the slurry placing hopper, adjusting the gap of the roller to be 6.2-6.6mm, passing the slurry through the roller to obtain uniformly laid slurry with the thickness of 0.2-0.6mm, uniformly laying the slurry on the melamine paper veneer, heating the surface of the fireproof plate and the veneer, and curing and shaping to obtain the substrate.

Comparative example six:

An adhesive is applied to the back of the melamine paper facing.

Putting the prepared pulp into a pulp hopper in a production line, adjusting the gap of a roller in the pulp hopper, adjusting the gap of the roller to be 6.2-6.6mm, passing the pulp through the roller to obtain evenly laid pulp with the thickness of 0.2-0.6mm, evenly laying the pulp on the melamine paper facing, carrying out cold pressing on the pulp, and then curing and shaping to obtain the substrate.

The density, flexural strength, softening coefficient, compressive strength and radiation shielding performance of the materials of the examples and the comparative examples are tested by the following methods:

(1) apparent density (kg/m)³): the determination was based on JC 646.

Then calculating the material according to the measured apparent densityDensity (t/m)³) The calculation formula is as follows: apparent density/open cell content. The opening ratio (%) is the area/cross-sectional area of the hole.

(2) Breaking strength: the determination was based on JC 646.

(3) Softening coefficient: the determination was carried out on the basis of GB/T1936.2-91.

(4) Compressive strength: the assay was performed based on GB/T19536-2004.

(5) Radiation shielding property: the determination was based on GBZ/T147-2002.

The material ratios in example 3 and comparative examples 1 to 2 are summarized in Table 1.

TABLE 1

The evaluation results of example 3 and comparative examples 1 to 2 are summarized in Table 2

TABLE 2

	Example 3	Comparative example 1	Comparative example 2
				Density of material	2.45	2.38	2.55
Flexural strength	25.1	28.2	23.5
				Coefficient of softening	0.89	0.92	0.88
Compressive strength	47.6	50.2	42.1
				Radiation shielding property	0.99	0.88	1.16

From tables 1-2, it can be seen that by adding the interwoven fabric in the production of the PP facing, the use of the subsequent process and the adhesive can be effectively reduced, and at the same time, each coefficient of the fireproof board is not significantly reduced, and the reduction in a large range does not occur.

The medium slurry mixing ratios in example 12 and comparative examples 3 to 4 are summarized in Table 3.

TABLE 3

Decorative surface	Example 3	Comparative example 1	Comparative example 2
				PVC	100	100	100
Interwoven fabric	√	×	×
				Slurry material	Example 3	Comparative example 1	Comparative example 2
Magnesium oxide	30	30	30
				Magnesium chloride solution	85	85	85
PP emulsion	370	340	410
				Substrate	Example 3	Comparative example 1	Comparative example 2
Adhesive agent	0	200	100
				Middle material	Example 3	Comparative example 1	Comparative example 2
Cement	100	100	100
				Water (W)	36	36	36
Lightweight aggregate	90	90	90
				Wood fiber	400	400	400

The evaluation results of example 12 and comparative examples 3 to 4 are summarized in Table 4

TABLE 4

As can be seen from tables 3-4, by adding the adhesive in the preparation of the PVC veneer, the subsequent process and the use of the adhesive can be effectively reduced, and meanwhile, all coefficients of the fireproof board are not obviously reduced, and the reduction in a large range is not caused.

The medium-size mixture ratios in example 21 and comparative examples 5 to 6 are summarized in Table 5.

TABLE 5

Decorative surface	Example 3	Comparative example 1	Comparative example 2
				Melamine paper	100	100	100
Interwoven fabric	√	×	×
				Slurry material	Example 3	Comparative example 1	Comparative example 2
Magnesium oxide	30	30	30
				Magnesium chloride solution	85	85	85
PP emulsion	370	340	410
				Substrate	Example 3	Comparative example 1	Comparative example 2
Adhesive agent	0	200	100
				Middle material	Example 3	Comparative example 1	Comparative example 2
Cement	100	100	100
				Water (W)	36	36	36
Lightweight aggregate	90	90	90
				Wood fiber	400	400	400

The evaluation results of example 21 and comparative examples 5 to 6 are summarized in Table 6

TABLE 6

	Example 12	Comparative example 3	Comparative example 4
				Density of material	2.49	2.30	2.49
Flexural strength	23.5	29.5	23.4
				Coefficient of softening	0.86	0.92	0.86
Compressive strength	42.5	51.5	42.4
				Radiation shielding property	1.13	0.92	1.15

From tables 5-6, it can be seen that by adding the adhesive in the preparation of the melamine paper veneer, the subsequent process and the use of the adhesive can be effectively reduced, and meanwhile, all coefficients of the fireproof board are not obviously reduced, and the reduction in a large range is not caused.

In conclusion, compared with the prior art, the method has the advantages that the subsequent processes can be effectively reduced by directly heating the facing material on the production line and then placing the interwoven fabric, meanwhile, because the facing material is processed to have a certain temperature, the use of the adhesive can be effectively reduced by placing the interwoven fabric on the back surface of the facing material, the interwoven fabric can be closely attached to the facing material after the facing material is cooled, so that the problem of secondary glue compounding is reduced, and then the interwoven fabric, the sizing agent and the middle material are mixed together to form a complete whole through the processes of placing the sizing agent and the middle material on the interwoven fabric, curing and the like so as to be bonded together, so that the use of the adhesive is effectively reduced, the production cost is reduced, and meanwhile, the use of the adhesive can also ensure the safety of workers, the composite facing material is more convenient and more environment-friendly to produce.

Although the illustrative embodiments of the present invention have been described above to enable those skilled in the art to understand the present invention, the present invention is not limited to the scope of the embodiments, and it is apparent to those skilled in the art that all the inventions utilizing the inventive concept are protected as long as they can be changed within the spirit and scope of the present invention as defined and defined by the appended claims.

Claims

1. A method for manufacturing a disposable composite veneer fireproof plate comprises the following steps:

heating: heating the facing material, wherein the facing material is in a liquid state,

extruding: extruding the facing material to obtain a softened facing material;

preparing a substrate: putting the slurry into a slurry discharging hopper in a production line, adjusting the gap of a roller in the slurry discharging hopper, enabling the slurry to pass through the roller to obtain the uniformly laid slurry, and uniformly laying the slurry on the facing to obtain a substrate;

demolding;

2. The method for making a disposable composite-faced fire-proof plate as claimed in claim 1, wherein said heating is performed with 100 parts of said facing material by mass.

3. The method of making a disposable composite-faced fire retardant panel as claimed in claim 2, wherein, for said heating, said facing material is PP or PVC or melamine paper.

4. The method of making a disposable composite-faced fire retardant panel of claim 1, wherein, for said heating, said facing material is heated to 150 ℃.

5. The method of making a disposable composite-faced fire retardant panel as claimed in claim 1, wherein, for said extruding, said facing material is roll formed by an embossing wheel to provide said softened facing material with a thickness of 0.3-0.5 mm.

6. A method of making a disposable composite-faced fire retardant panel in accordance with claim 1, wherein an adhesive is applied to the back surface of said softened facing material during said pressing.

7. The method of making a disposable composite-faced fire retardant panel in accordance with claim 6, wherein, for said extruding, said adhesive is a paste.

8. The method of making a disposable composite-faced fire retardant panel in accordance with claim 6, wherein said softening facing material is at a temperature of from 50 ℃ to 60 ℃ during said extruding.

9. The method of claim 1 wherein, in the extruding, the interwoven fabric is woven from glass filaments.

10. The method for making a disposable composite-faced fire-proof plate as claimed in claim 1, wherein, in the step of preparing the slurry, the slurry material comprises the following components in parts by mass: 50 parts of magnesium oxide, 50-60 parts of magnesium chloride solution and 5-10 parts of PP emulsion.