CN105602078B - A kind of expansion type flame-retarding eva foam composite and its preparation method and application - Google Patents

Abstract

The invention discloses an intumescent flame-retardant EVA foam composite material and its preparation method and application. The foam composite material is composed of EVA, an intumescent compound flame retardant, a foaming agent, a crosslinking agent, stearic acid, hard Zinc fatty acid and zinc oxide are mixed and cross-linked and foamed; the intumescent compound flame retardant is: ammonium polyphosphate derivatives are used as acid source and gas source, expandable graphite is used as synergist, and wood powder is used as The carbon source is composed of ammonium polyphosphate derivatives, expandable graphite and wood flour in a mass ratio of 1-4:1:3; the ammonium polyphosphate derivatives are obtained by reacting ammonium polyphosphate and ethylenediamine. Compared with the traditional flame-retardant EVA foam composite material, the intumescent flame-retardant EVA foam composite material prepared by the present invention has a better flame-retardant effect, the oxygen index is 26.3%~27.6%, the UL-94 grade is V-0, and the combustion The carbon residue layer is denser and has better processing performance, which has a wide range of social and economic benefits.

Description

A kind of intumescent flame-retardant EVA foam composite material and its preparation method and application

technical field

The invention belongs to the technical field of polymer composite materials, and in particular relates to an intumescent flame-retardant EVA foam composite material and a preparation method and application thereof.

Background technique

Ethylene-vinyl acetate copolymer (EVA) has good mechanical and processing properties, and does not lack flexibility and elasticity. Therefore, it is widely used in packaging, building materials, sports equipment, footwear and other fields. But because the EVA foam material is extremely flammable, the limiting oxygen index only reaches about 18%, which greatly limits its application range. Therefore, it is necessary to carry out flame retardant modification treatment on it.

The use types of flame retardants can be divided into additive type and reactive type. Although the reactive flame retardant has good flame retardancy, its process flow is relatively complicated and the cost is high, which is not conducive to industrialization and its application is relatively narrow; the additive flame retardant has a relatively simple flame retardant process, low cost, and There are also many types of fuels and a wide range of applications. Traditional additive flame retardants include halogen series and heavy metals. Although these two types of flame retardants have good flame retardant effects, they will produce toxic and harmful gases during the flame retardant process, which is not conducive to application and pollutes the environment. Inorganic flame retardants are low in cost and have good flame retardant effects, but their addition is too large and their compatibility with the polymer matrix is poor, which greatly reduces their physical and mechanical properties. Intumescent flame retardants can avoid harmful substances very well and have good compatibility with polymer matrix, but the flame retardant effect is not stable. Therefore, adding intumescent compound flame retardants to EVA synthesizes a kind of flame retardant Intumescent flame-retardant EVA foam composite material with stable flame effect is very meaningful.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the prior art, and the present invention provides an intumescent flame-retardant EVA foam composite material and a preparation method thereof. The prepared foam composite material has the advantages of good flame retardancy, processability, physical and mechanical properties and the like.

To achieve the above object, the present invention adopts the following technical solutions:

An intumescent flame-retardant EVA foam composite material, the raw materials of which consist of:

EVA: 60~100phr;

Intumescent compound flame retardant: 10~40 phr;

Foaming agent: 2~3 phr;

Cross-linking agent: 0.5~1.5 phr;

Stearic acid (St): 0.5~1 phr;

Zinc stearate (ZnSt): 0.1~0.3 phr;

Zinc oxide (ZnO): 0.2~0.8 phr;

The described intumescent composite flame retardant is: with ammonium polyphosphate derivative (MAPP) as acid source and gas source, expandable graphite (EG) as synergist, wood flour (MF) as carbon source, MAPP, EG and MF are compounded at a mass ratio of 1-4:1:3; the ammonium polyphosphate derivative (MAPP) is obtained by reacting ammonium polyphosphate (APP) and ethylenediamine (EDA).

The foaming agent is azodicarbonamide (AC).

The cross-linking agent is dicumyl peroxide (DCP).

The preparation method of the intumescent compound flame retardant is as follows: wood flour (MF) and dioctyl phthalate (DOP) are placed in a high-speed kneader according to a mass ratio of 5:1, and stirred for 10 min. Plasticizing treatment: place ammonium polyphosphate derivatives (MAPP), expandable graphite (EG) and plasticized wood flour (MF) in a high-speed kneader and mix evenly.

A kind of preparation method of expandable flame-retardant EVA foam composite material as described above, specifically comprises the following steps:

(1) Put EVA and intumescent compound flame retardant in a banbury mixer for 5 minutes, and the banburying conditions are 100°C and 25 rpm/min;

(2) Add foaming agent, crosslinking agent, stearic acid, zinc stearate and zinc oxide to the homogeneously mixed material in step (1), continue banburying for 10 minutes and then discharge the material. The banburying condition is 100°C , speed 25 rpm/min;

(3) Transfer the mixed material in step (2) to an open double-roller mill while hot, press it into thin slices with a thickness of 3~5mm, and cut them into square sheets;

(4) Place the cut sheet in step (3) in the mold of a preheated flat vulcanizer for molding and foaming treatment to obtain an intumescent flame-retardant EVA foam composite material. The molding and foaming treatment condition is a pressure of 10 MPa , temperature 180°C, AC foaming for 10 min.

The expanded flame-retardant EVA foam composite material is applied to the fields of packaging, building materials, sports equipment and footwear.

The beneficial effect of the present invention is that: the intumescent flame-retardant EVA foam composite material prepared by the present invention has better flame-retardant effect than the traditional flame-retardant EVA foam material, the oxygen index is 26.3%~27.6%, UL-94 The grade is V-0; Compared with traditional flame-retardant EVA foam materials, it has better processing performance and physical and mechanical properties, and has broad market prospects and significant social and economic benefits.

Description of drawings

Fig. 1 is the residual charcoal SEM picture of intumescent flame-retardant EVA foam composite material and common flame-retardant EVA foam composite material;

Fig. 2 is the HRR curve and the THR curve of intumescent flame-retardant EVA foam composite material and common flame-retardant EVA foam composite material;

Fig. 3 is the tensile strength curve of intumescent flame-retardant EVA foam composite material and common flame-retardant EVA foam composite material.

detailed description

The present invention will be further described below in conjunction with specific examples, but the present invention is not limited to these examples.

comparative example

A kind of EVA foam composite material, its raw material consists of:

EVA: 80phr;

AC: 2.5phr;

DCP: 0.9phr;

St: 0.5 phr;

ZnSt: 0.1 phr;

ZnO: 0.5 phr;

The preparation steps of EVA foam composite material are as follows:

(1) Put EVA, AC, DCP, St, ZnSt, and ZnO in an internal mixer for 15 minutes, and the mixing conditions are 100°C and 25 rpm/min;

(2) Transfer the mixed material in step (1) to an open double-roller mill while hot, press it into a sheet with a thickness of 4mm, and cut it into a square sheet;

(3) Place the cut sheet in step (2) in the preheated plate vulcanizing machine mold for molding and foaming treatment to obtain EVA foam composite material. The molding and foaming treatment conditions are pressure 10 MPa and temperature 180 °C , AC foaming for 10 min.

Example 1

An intumescent flame-retardant EVA foam composite material, the raw materials of which consist of:

EVA: 60phr;

Intumescent compound flame retardant: 10 phr;

AC: 2phr;

DCP: 0.5phr;

St: 0.7 phr;

ZnSt: 0.2 phr;

ZnO: 0.2 phr;

The preparation method of the intumescent composite flame retardant is as follows: APP and EDA are reacted to obtain MAPP; MF and DOP are placed in a high-speed kneader according to a mass ratio of 5:1, and stirred for 10 min for plasticization; The prepared MAPP, EG and plasticized MF (the mass ratio of MAPP, EG and MF is 1:1:3) were placed in a high-speed kneader and mixed evenly.

A kind of preparation method of expandable flame-retardant EVA foam composite material as described above, specifically comprises the following steps:

(1) Put EVA and intumescent compound flame retardant in a banbury mixer for 5 minutes, and the banburying conditions are 100°C and 25 rpm/min;

(2) Add AC, DCP, St, ZnSt and ZnO to the homogeneously mixed material in step (1), continue banburying for 10 minutes and discharge;

(3) Transfer the mixed material in step (2) to an open double-roller mill while hot, press it into a sheet with a thickness of 3mm, and cut it into a square sheet;

(4) Place the cut sheet in step (3) in the mold of a preheated flat vulcanizer for molding and foaming treatment to obtain an intumescent flame-retardant EVA foam composite material. The molding and foaming treatment condition is a pressure of 10 MPa , temperature 180°C, AC foaming for 10 min. .

Example 2

An intumescent flame-retardant EVA foam composite material, the raw materials of which consist of:

EVA: 80phr;

Intumescent compound flame retardant: 20 phr;

AC: 2.5phr;

DCP: 0.9phr;

St: 0.5 phr;

ZnSt: 0.1 phr;

ZnO: 0.5 phr;

The preparation method of the intumescent composite flame retardant is as follows: APP and EDA are reacted to obtain MAPP; MF and DOP are placed in a high-speed kneader according to a mass ratio of 5:1, and stirred for 10 min for plasticization; The prepared MAPP, EG and plasticized MF (the mass ratio of MAPP, EG and MF is 2:1:3) were placed in a high-speed kneader and mixed evenly.

A kind of preparation method of expandable flame-retardant EVA foam composite material as described above, specifically comprises the following steps:

(1) Put EVA and intumescent compound flame retardant in a banbury mixer for 5 minutes, and the banburying conditions are 100°C and 25 rpm/min;

(2) Add AC, DCP, St, ZnSt and ZnO to the homogeneously mixed material in step (1), continue banburying for 10 minutes and discharge;

(3) Transfer the mixed material in step (2) to an open double-roller mill while hot, press it into a sheet with a thickness of 4mm, and cut it into a square sheet;

(4) Place the cut sheet in step (3) in the mold of a preheated flat vulcanizer for molding and foaming treatment to obtain an intumescent flame-retardant EVA foam composite material. The molding and foaming treatment condition is a pressure of 10 MPa , temperature 180°C, AC foaming for 10 min.

Example 3

An intumescent flame-retardant EVA foam composite material, the raw materials of which consist of:

EVA: 100phr;

Intumescent compound flame retardant: 40 phr;

AC: 3phr;

DCP: 1.5phr;

St: 1 phr;

ZnSt: 0.3 phr;

ZnO: 0.8phr;

The preparation method of the intumescent composite flame retardant is as follows: APP and EDA are reacted to obtain MAPP; MF and DOP are placed in a high-speed kneader according to a mass ratio of 5:1, and stirred for 10 min for plasticization; The prepared MAPP, EG and plasticized MF (the mass ratio of MAPP, EG and MF is 3:1:3) were placed in a high-speed kneader and mixed evenly.

A kind of preparation method of expandable flame-retardant EVA foam composite material as described above, specifically comprises the following steps:

(1) Put EVA and intumescent compound flame retardant in a banbury mixer for 5 minutes, and the banburying conditions are 100°C and 25 rpm/min;

(2) Add AC, DCP, St, ZnSt and ZnO to the homogeneously mixed material in step (1), continue banburying for 10 minutes and discharge;

(3) Transfer the mixed material in step (2) to an open double-roller mill while hot, press it into a sheet with a thickness of 5mm, and cut it into a square sheet;

(4) Place the cut sheet in step (3) in the mold of a preheated flat vulcanizer for molding and foaming treatment to obtain an intumescent flame-retardant EVA foam composite material. The molding and foaming treatment condition is a pressure of 10 MPa , temperature 180°C, AC foaming for 10 min.

Example 4

An intumescent flame-retardant EVA foam composite material, the raw materials of which consist of:

EVA: 90 phr;

Intumescent compound flame retardant: 30 phr;

AC: 2.7phr;

DCP: 1.2phr;

St: 0.8phr;

ZnSt: 0.2 phr;

ZnO: 0.5 phr;

The preparation method of the intumescent composite flame retardant is as follows: APP and EDA are reacted to obtain MAPP; MF and DOP are placed in a high-speed kneader according to a mass ratio of 5:1, and stirred for 10 min for plasticization; The prepared MAPP, EG and plasticized MF (the mass ratio of MAPP, EG and MF is 4:1:3) were placed in a high-speed kneader and mixed evenly.

A kind of preparation method of expandable flame-retardant EVA foam composite material as described above, specifically comprises the following steps:

(1) Put EVA and intumescent compound flame retardant in a banbury mixer for 5 minutes, and the banburying conditions are 100°C and 25 rpm/min;

(2) Add AC, DCP, St, ZnSt and ZnO to the homogeneously mixed material in step (2), continue banburying for 10 minutes and discharge;

(3) Transfer the mixed material in step (2) to an open double-roller mill while hot, press it into a sheet with a thickness of 5mm, and cut it into a square sheet.

(4) Place the cut sheet in step (3) in the mold of a preheated flat vulcanizer for molding and foaming treatment to obtain an intumescent flame-retardant EVA foam composite material. The molding and foaming treatment condition is a pressure of 10 MPa , temperature 180°C, AC foaming for 10 min.

Performance Testing

Table 1 is the flame retardant data of the expanded flame retardant foam composite material, as can be seen from the table, compared with the comparative example, the flame retardant performance of the expanded flame retardant foam composite material prepared by the present invention is obviously improved, and the oxygen index is 26.3 %~27.6%, significantly higher than 18% of the comparative example, and the UL-94 grade is V-0.

Table 1 Flame retardant data of intumescent flame retardant foam composites

Fig. 1 is the carbon residue scanning electron microscope picture of intumescent flame-retardant EVA foam composite material (A) and common flame-retardant EVA foam composite material (B). Comparing Figure A and Figure B, it can be clearly found that the carbon residue layer after combustion of the intumescent flame-retardant EVA foam composite material is denser and has fewer defects. The dense and regular carbon residue layer can effectively block or slow down the external heat and oxygen from entering the material, and play the role of heat insulation and oxygen insulation. Therefore, the flame retardant effect is better after adding intumescent flame retardant.

Figure 2 shows the HRR curve (Figure 2(a)) and THR curve (Figure 2(b)) of the intumescent flame-retardant EVA foam composite (A) and the common flame-retardant EVA foam composite (B). It is not difficult to find from the figure that the heat release rate (HRR) of the intumescent flame-retardant EVA foam composite material is significantly lower than that of the ordinary flame-retardant foam composite material, and the time of the maximum heat release rate is also delayed. From the total heat release (THR) curve, it can be seen that the total release of intumescent flame-retardant foam composites is small. It can be seen that the intumescent flame-retardant EVA foam composite material has a good flame-retardant effect.

Fig. 3 is the tensile strength curve of intumescent flame-retardant foam composite material (A) and common flame-retardant foam composite material (B). It can be seen from the figure that when the flame retardant is added at the same amount, the intumescent flame-retardant foam composite has better tensile strength, because the compatibility between the flame retardant and the material is better.

The expanded flame-retardant EVA foam composite material provided by the invention can be widely used in the fields of packaging, building materials, sports equipment, footwear and the like.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (4)

1. an intumescent flame-retardant EVA foam composite material, is characterized in that: the raw material of described foam composite material consists of: EVA: 60~100phr; Intumescent compound flame retardant: 10~40 phr; Foaming agent: 2~3 phr; Cross-linking agent: 0.5~1.5 phr; Stearic acid: 0.5~1 phr; Zinc stearate: 0.1~0.3 phr; Zinc oxide: 0.2~0.8 phr; The intumescent composite flame retardant is as follows: ammonium polyphosphate derivatives are used as acid source and gas source, expandable graphite is used as synergist, wood powder is used as carbon source, ammonium polyphosphate derivatives, expandable graphite and wood The powder is compounded according to the mass ratio of 1~4:1:3; the ammonium polyphosphate derivative is obtained by reacting ammonium polyphosphate and ethylenediamine; the preparation method of the intumescent compound flame retardant is as follows: Wood powder and dioctyl phthalate were placed in a high-speed kneader according to a mass ratio of 5:1, and stirred for 10 min for plasticization; ammonium polyphosphate derivatives, expandable graphite, and plasticized wood powder Place in a high-speed kneader and mix uniformly; the preparation method of the expanded flame-retardant EVA foam composite material, the specific steps include: (1) Put the EVA and intumescent compound flame retardant in the internal mixer for 5 minutes; (2) Add foaming agent, cross-linking agent, stearic acid, zinc stearate and zinc oxide to the homogeneously mixed material in step (1), continue banburying for 10 minutes and discharge; (3) Transfer the mixed material in step (2) to an open double-roller mill while hot, press it into thin slices with a thickness of 3~5mm, and cut them into square sheets; (4) Place the cut sheet in step (3) in the mold of a preheated flat vulcanizer for molding and foaming treatment. The pressure, temperature, and foaming time are respectively 10 MPa, 180°C, and 10 min. Obtain intumescent flame-retardant EVA foam composite material; The banburying conditions in step (1) and step (2) are: the temperature is 100°C, and the rotation speed is 25 rpm. 2. The intumescent flame-retardant EVA foam composite material according to claim 1, characterized in that: the blowing agent is azodicarbonamide. 3. A kind of intumescent flame-retardant EVA foam composite material according to claim 1, characterized in that: said crosslinking agent is dicumyl peroxide. 4. An application of the intumescent flame-retardant EVA foam composite material as claimed in claim 1, characterized in that: the composite material is applied to the fields of packaging, building materials, sports equipment and footwear.