阅读说明：本技术 一种包覆改性eps泡沫制品及其制备方法 (Coated modified EPS foam product and preparation method thereof ) 是由 张海英 于 2021-06-08 设计创作，主要内容包括：本发明公开了一种包覆改性EPS泡沫制品及其制备方法,该泡沫制品以EPS泡沫粒子为基核,包覆了两层包覆层,第一层是聚丁二烯合成乳胶和硅烷偶联剂的表面处理层,第二层是以硅酸盐为包覆基体的阻燃防火层,两层结构使得所述泡沫制品整体力学性能更稳定,压缩、拉伸和弯曲强度更好。先对预发泡的EPS泡沫粒子表面进行预处理,使得其与无机阻燃剂更具亲合性,包覆粘黏效果更好,阻燃性能大大提升,垂直燃烧等级可达FV-0。(The invention discloses a coated modified EPS foam product and a preparation method thereof, the foam product takes EPS foam particles as a basal core and is coated with two coating layers, the first layer is a surface treatment layer of polybutadiene synthetic latex and a silane coupling agent, the second layer is a flame-retardant fire-proof layer taking silicate as a coating basal body, and the two-layer structure ensures that the overall mechanical property of the foam product is more stable and the compressive, tensile and bending strength is better. The surface of the pre-expanded EPS foam particles is pretreated firstly, so that the particles have affinity with inorganic flame retardant, the coating adhesion effect is better, the flame retardant property is greatly improved, and the vertical combustion grade can reach FV-0.)

1. A coated modified EPS foam article characterized by: EPS foam particles are taken as a base core and coated with two coating layers, wherein the first layer is a surface treatment layer of the EPS foam particles, and the main components are a coupling agent and a polymer latex adhesive; the second layer is a flame-retardant fire-proof layer which mainly takes inorganic flame retardant as a coating substrate.

2. A process for the preparation of a coated modified EPS foam article according to claim 1, comprising the steps of:

s1, selecting EPS raw material particles, adding a foaming agent, and pre-foaming for a period of time under the action of a certain heating temperature and vapor pressure to prepare pre-foamed EPS foam particles;

s2, adding a coupling agent and an adhesive into modification equipment to perform surface treatment on the pre-expanded EPS foam particles, stirring and mixing, coating a surface treatment layer, and performing heat preservation and drying to prepare pre-expanded EPS foam particles with better affinity with the inorganic flame retardant;

s3, mixing the foam particles obtained in the step S2 with an inorganic flame-retardant coating substrate, adding a synergistic flame retardant and a dispersing agent, and stirring to coat the second flame-retardant fireproof layer;

and S4, pumping the pre-foamed EPS foam particles coated with the two layers into a curing bin for curing, pumping the cured particles into a mold for heating and molding twice after curing for a period of time at a certain temperature, and cooling, ejecting, drying and cutting to obtain the coated modified EPS foam product.

3. The process for the preparation of a coated modified EPS foam article according to claim 2, wherein in the S1 step: the particle size of the EPS raw material particles is 0.7-0.9mm, the foaming agent is n-pentane, the content of the foaming agent is 4% -7% of that of the EPS raw material particles, the heating temperature is 70-90 ℃, the steam pressure is 0.11-0.16MPa, and the pre-foaming time is 5-10 min.

4. The process for the preparation of a coated modified EPS foam article according to claim 2, wherein in the S2 step: the coupling agent is silane, the adding amount of the coupling agent is 0.9-1.4% of the total mass of the adhesive, the adhesive is synthetic latex of which the main component is polybutadiene, and the adding amount of the coupling agent is 65-75% of the total mass of the pre-expanded EPS foam particles.

5. The process for the preparation of a coated modified EPS foam article according to claim 2, wherein in the S3 step: the coating matrix is silicate, the addition amount of the silicate is 75-90% of the total mass of the pre-expanded EPS foam particles, the synergistic flame retardant is cement fly ash and polypropylene fiber with a water-cement ratio of 5:8, the addition amount of the cement fly ash is 40-50% of the total mass of the silicate, the polypropylene fiber is 0.3-0.6% of the total mass of the silicate, and the dispersing agent is one or more of calcium phosphate, magnesium carbonate and talcum powder.

6. The process for the preparation of a coated modified EPS foam article according to claim 2, wherein in the S4 step: the curing time is 8-12h, the curing temperature is 50-60 ℃, the temperature of the introduced water vapor during the molding is 120-130 ℃, the pressure is 0.13-0.17MPa, and the heating time of the two times of water vapor introduction is 15s and 10s respectively.

Technical Field

The invention relates to a light and fireproof heat-insulating material used in the construction and packaging industries, in particular to a coated modified EPS foam product and a preparation method thereof.

Background

The EPS foam product is prepared by foaming and curing polystyrene (EPS) foam particles under the action of a foaming agent and then heating and molding the foam particles by a mold. The EPS foam has the characteristics of light weight, good heat insulation and sound insulation performance, impact resistance, aging resistance and the like, and is widely applied to the fields of buildings and packaging. In order to improve the problems of flammability, compression, tensile strength and insufficient bending strength, a fire retardant and a reinforcing agent are added in the processing process to coat and modify EPS particles, or a fire-proof layer is coated on the surface of a finished plate or the surface of the finished plate is soaked in a solution for permeation modification, so that the modified EPS foam product has good fire resistance and mechanical strength.

In the existing EPS foam particle coating modification technology, an inorganic material is taken as a coating matrix, a binder is added, a surface treatment agent is also required to be added, the affinity between the coating matrix and EPS foam particles is increased, the coating matrix is subjected to surface treatment modification, then other additives are added to prepare a coating solution or slurry, and then pre-expanded EPS foam particles are mixed and coated, or the matrix, the surface treatment agent and other additives are directly coated with the pre-expanded EPS foam particles by a solution blending method. The two methods have simple flow, but the product only has one coating layer, has single structure, is easy to damage, is directly mixed and coated, has insufficient dispersion uniformity of each component, and influences the bonding effect and the flame retardant effect.

Disclosure of Invention

In order to provide an EPS foam product which has simple manufacturing process, stable coating structure and certain flame retardance, the invention discloses a coated modified EPS foam product, wherein the EPS foam product takes EPS foam particles as a base core and is coated with two coating layers, the first layer is a surface treatment layer of the EPS foam particles, and the main components are a coupling agent and a polymer latex adhesive; the second layer is an inorganic flame-retardant reinforced fireproof layer, and the main component of the second layer is a flame-retardant fireproof layer taking an inorganic flame retardant as a coating substrate.

A method for preparing a coated modified EPS foam article, comprising the steps of:

s1, selecting EPS raw material particles, adding a foaming agent, and pre-foaming for a period of time under the action of a certain heating temperature and vapor pressure to prepare pre-foamed EPS foam particles;

s2, adding a coupling agent and an adhesive into modification equipment to perform surface treatment on the pre-expanded EPS foam particles, stirring and mixing, coating a surface treatment layer, and performing heat preservation and drying to prepare pre-expanded EPS foam particles with better affinity with the inorganic flame retardant;

s3, mixing the foam particles obtained in the step S2 with an inorganic flame-retardant coating substrate, adding a synergistic flame retardant and a dispersing agent, and stirring to coat the second flame-retardant fireproof layer;

and S4, pumping the pre-foamed EPS foam particles coated with the two layers into a curing bin for curing, pumping the cured particles into a mold for heating and molding twice after curing for a period of time at a certain temperature, and cooling, ejecting, drying and cutting to obtain the coated modified EPS foam product.

Preferably, in step S1: the particle size of the EPS raw material particles is 0.7-0.9mm, the foaming agent is n-pentane, the content of the foaming agent is 4-7% of that of the EPS raw material particles, the heating temperature is 70-90 ℃, the steam pressure is 0.11-0.16MPa, and the pre-foaming time is 5-10 min.

Preferably, in step S2: the coupling agent is silane, the adding amount of the coupling agent is 0.9-1.4% of the total mass of the adhesive, the adhesive is synthetic latex of which the main component is polybutadiene, and the adding amount of the coupling agent is 65-75% of the total mass of the pre-expanded EPS foam particles.

Preferably, in step S3: the coating matrix is silicate, the addition amount of the silicate is 75-90% of the total mass of the pre-expanded EPS foam particles, the synergistic flame retardant is cement fly ash and polypropylene fiber with a water-cement ratio of 5:8, the addition amount of the cement fly ash is 40-50% of the total mass of the silicate, the polypropylene fiber is 0.3-0.6% of the total mass of the silicate, and the dispersing agent is one or more of calcium phosphate, magnesium carbonate and talcum powder.

Preferably, in step S4: the curing time is 8-12h, the curing temperature is 50-60 ℃, the temperature of the introduced water vapor during the molding is 120-130 ℃, the pressure is 0.13-0.17MPa, and the heating time of the two times of water vapor introduction is 15s and 10s respectively.

The invention has the advantages that:

1. when the EPS foam particles after surface treatment are recoated, the surfaces of the EPS foam particles have affinity, so that the flame retardant is dispersed more uniformly, the adhesion and coating effects are better, and a good flame-retardant and fireproof effect can be achieved.

2. The particles of the EPS foam board obtained have two coating layers, wherein the first layer is a surface treatment layer, the second layer is a flame-retardant layer, and the two layers of structures ensure that the overall mechanical property is more stable and the compressive strength, the tensile strength and the bending strength are better.

Detailed Description

Five products prepared by five schemes are used for performance comparison, wherein the comparative example 1 is a blank experimental scheme, and an unmodified EPS foam plate is prepared; comparative example 2 is that the surface of the coated substrate is pretreated, and then the coated substrate is directly mixed with the pre-expanded EPS foam particles for coating; examples 1-3 are the preparation provided by the present invention.

The respective formulation compositions are shown in Table 1.

Table 1:

comparative example 1:

s1, 100 parts of EPS raw material particles with the particle size of 0.8mm and 5 parts of n-pentane, and pre-foaming for 7min under the action of heating temperature of 80 ℃ and steam pressure of 0.14MPa to obtain pre-foamed EPS foam particles.

S2, pouring the pre-expanded EPS foam particles into a curing bin, and curing for 8 hours at the temperature of 55 ℃.

And S3, pouring the cured EPS foam particles into a mold, introducing water vapor with the temperature of 125 ℃ and the pressure of 0.15MPa, and introducing the water vapor for two times for 15S and 10S to ensure that the EPS foam particles expand to fill the whole mold.

And S4, cooling the die by adopting a water cooling and vacuum cooling combined mode, ejecting the EPS foam by using compressed air, and drying and cutting to obtain the product A.

Comparative example 2:

s1, the same procedure as S1 of comparative example 1 gave pre-expanded EPS foam particles.

S2, adding 0.84 part of silane coupling agent into 70 parts of ethanol dispersing agent, and uniformly dispersing.

S3, dehydrating and drying 80 parts of silicate for 1 hour, adding the dispersed silane coupling agent, and mixing and stirring at 75 ℃ for 15min to obtain the silicate coating liquid with the surface being pretreated.

S4, mixing the silicate coating liquid with the pre-expanded EPS particles, and adding water-cement ratio of 5: and 8, stirring, mixing and coating 36 parts of cement fly ash and 0.32 part of polypropylene fiber under the action of 6.5 parts of talcum powder dispersing agent for 30 min.

S5, dehydrating and drying the coated EPS foam particles, and curing, molding, drying and cutting the EPS foam particles to obtain a product B in the same way as the S2-S4 of the comparative example 1.

Example 1:

s1, the same procedure as S1 of comparative example 1 gave pre-expanded EPS foam particles.

S2, adding 70 parts of synthetic latex with polybutadiene as a main component and 0.84 part of silane coupling agent into modification equipment, mixing with the pre-expanded EPS foam particles, stirring for 15min, coating a surface treatment layer, and drying at 40 ℃ for 1h to obtain the pre-expanded EPS foam particles with better affinity with the inorganic flame retardant.

S3, adding 80 parts of silicate, wherein the water-cement ratio is 5: and 8, stirring and mixing 36 parts of cement fly ash and 0.32 part of polypropylene fiber with the foam particles obtained in the step S2 under the action of 6.5 parts of talcum powder dispersing agent for 30min, and coating a second flame-retardant fireproof layer.

S4, curing, molding, drying and cutting the pre-expanded EPS foam particles coated with the two layers to obtain a product C as with S2-S4 of the comparative example 1.

Example 2:

s1, 100 parts of EPS raw material particles with the particle size of 0.7mm and 4 parts of n-pentane, and pre-foaming for 10min under the action of heating temperature of 75 ℃ and steam pressure of 0.12MPa to obtain pre-foamed EPS foam particles.

S2, adding 65 parts of synthetic latex with polybutadiene as the main component and 0.65 part of silane coupling agent into modification equipment, mixing with the pre-expanded EPS foam particles, stirring for 15min, coating a surface treatment layer, and drying at 40 ℃ for 1h to obtain the pre-expanded EPS foam particles with better affinity with the inorganic flame retardant.

S3, adding 75 parts of silicate, wherein the water-cement ratio is 5: and (3) stirring and mixing 30 parts of cement fly ash 8 and 0.23 part of polypropylene fiber with the foam particles obtained in the step S2 under the action of 6.5 parts of calcium phosphate dispersing agent for 30min, and coating a second flame-retardant fireproof layer.

S4, pouring the pre-expanded EPS foam particles into a curing bin, and curing for 10 hours at the temperature of 60 ℃.

And S5, pouring the cured EPS foam particles into a mold, introducing water vapor with the temperature of 120 ℃ and the pressure of 0.13MPa, and introducing the water vapor for 15S and 10S twice to ensure that the EPS foam particles expand to fill the whole mold.

And S6, cooling the die by adopting a water cooling and vacuum cooling combined mode, ejecting the EPS foam by using compressed air, and drying and cutting to obtain a product D.

Example 3:

s1, 100 parts of EPS raw material particles with the particle size of 0.9mm and 7 parts of n-pentane, and pre-foaming for 5min under the action of heating temperature of 90 ℃ and steam pressure of 0.15MPa to obtain pre-foamed EPS foam particles.

S2, adding 75 parts of synthetic latex with polybutadiene as the main component and 1.05 parts of silane coupling agent into modification equipment, mixing with the pre-expanded EPS foam particles, stirring for 15min, coating a surface treatment layer, and drying at 40 ℃ for 1h to obtain the pre-expanded EPS foam particles with better affinity with the inorganic flame retardant.

S3, adding 90 parts of silicate, wherein the water-cement ratio is 5: and (3) stirring and mixing 45 parts of cement fly ash 8 and 0.54 part of polypropylene fiber with the foam particles obtained in the step S2 under the action of 6.5 parts of magnesium carbonate dispersing agent for 30min, and coating a second flame-retardant fireproof layer.

S4, pouring the pre-expanded EPS foam particles into a curing bin, and curing for 12 hours at the temperature of 50 ℃.

And S5, pouring the cured EPS foam particles into a mold, introducing water vapor with the temperature of 130 ℃ and the pressure of 0.17MPa, and introducing the water vapor for 15S and 10S twice to ensure that the EPS foam particles expand to fill the whole mold.

And S6, cooling the die by adopting a water cooling and vacuum cooling combined mode, ejecting the EPS foam by using compressed air, and drying and cutting to obtain a product E.

The product A, B, C, D, E was subjected to mechanical testing and combustion testing and its properties are shown in Table 2.

The foam samples were tested for compressive strength properties according to GB/T8813-2008, the samples were compressed at a constant rate of 5mm/min and the compressive stress was determined at 10% relative deformation.

The foam samples were tested for tensile strength properties according to GB/T9641-1988 at a tensile rate of 5 mm/min.

The foam samples were tested for flexural strength properties according to GB/T9341-2008 with the test rate set at 10 mm/min.

The measurement of the oxygen index of the foam sample according to GB/T2406.2-2009 means that the foam sample is in a certain proportion of mixed nitrogen and oxygen, and the minimum oxygen concentration required for just maintaining the combustion of the sample is expressed by the volume fraction of oxygen under a certain condition.

According to GB/T2408-2008, the vertical burning grade measurement is carried out on the foam sample, the foam sample in a vertical state is periodically burnt for a plurality of times according to a certain flame height and a certain flame application angle, and the combustibility of the foam sample is evaluated according to the ignition time of the foam sample, the burning duration and whether the ignition substances of the bedding under the foam sample are ignited.

Table 2:

the product C, D, E prepared by the invention has good mechanical property and flame retardant effect. Compared with the product A, the product C has the advantages that the compression strength is improved by 235.2%, the tensile strength is improved by 18.2%, the bending strength is improved by 17.1%, the limiting oxygen index is improved by 109.6%, the compression strength is improved by 16.3%, the tensile strength is improved by 6.5%, the bending strength is improved by 4.2%, and the limiting oxygen index is improved by 14.5%.