CN111534172A

CN111534172A - Composite strippable emulsion, strippable protective coating and application thereof

Info

Publication number: CN111534172A
Application number: CN202010397408.2A
Authority: CN
Inventors: 刘正阳; 钟瑞峰
Original assignee: Shoutou Technology Guangzhou Co ltd; Guangzhou First Lead Chemical Co ltd
Current assignee: Shoutou Technology Guangzhou Co ltd; Guangzhou First Lead Chemical Co ltd
Priority date: 2020-05-12
Filing date: 2020-05-12
Publication date: 2020-08-14

Abstract

The invention relates to the technical field of protective products, in particular to a composite strippable emulsion, a strippable protective coating and application thereof. The composite strippable emulsion comprises acrylic acid self-film-forming emulsion and acrylic acid self-crosslinking emulsion, wherein the weight ratio of the acrylic acid self-film-forming emulsion to the acrylic acid self-crosslinking emulsion is (65-85): (10-25). The composite strippable emulsion has strong cohesive force, so that the protective coating is not easy to break in the stripping process and has no residue on the base material, and the composite strippable emulsion has moderate adhesive force with the base material, so that the composite strippable emulsion can ensure the good adhesion of a coating film to the base material, effectively protect a product from being damaged in the transportation process, can be easily stripped when the stripping is needed, does not reduce the glossiness of the surfaces of the base materials such as woodware, metal, glass, plastic, concrete and the like, and does not influence the comprehensive performance of the base material. In addition, the composite strippable emulsion can be used alone or can be compounded with a top coat for use.

Description

Composite strippable emulsion, strippable protective coating and application thereof

Technical Field

The invention relates to the technical field of protective products, in particular to a composite strippable emulsion, a strippable protective coating and application thereof.

Background

In the manufacturing industry, in the process of influencing external environments such as processing, transportation and storage of automobiles, mechanical parts, some precision instruments and the like, dust, water vapor, oil stains or even rays are often damaged to a certain extent, scratches are sometimes caused or the surface of the automobile is damaged due to collision, so that the appearance of the automobile is influenced, and the performance of the automobile is reduced or even the automobile is scrapped. The strippable emulsion or paint is used as a special functional paint, is brushed on the surface of a material workpiece, and can form a closed protective film after being dried, thereby playing a role in temporary protection. After the protection task is finished, the coating can be manually and completely peeled off, and the original appearance and performance of the surface of the workpiece are still kept.

In order to improve the construction and installation efficiency, more and more prefabricated parts are assembled on site, that is, workpieces are produced in a factory and transported to the site for assembly, the prefabricated parts (or finished products) are transported to the site for a long distance after being taken off line from the factory, protection needs to be made in the whole transportation process, a PE/PP winding film is generally used in the prior art, on one hand, raw materials are not degradable, the environment is polluted, and on the other hand, special-shaped parts are difficult to process. Although the strippable coating protects the workpieces, the workpieces need to be cleaned and cared daily according to different use environments, so that the workpieces are prevented from being damaged in the use process, the workpieces are frequently recoated and repaired, and the service lives of the workpieces are prolonged. Moreover, the strippable emulsion requires that a paint film is not easy to break in the stripping process and has no residue on a base material, and the adhesion force of the resin and the base material is moderate, so that the adhesion of the paint film to the base material can be ensured, and the paint film can be easily stripped when the paint film needs to be stripped. However, the conventional strippable emulsions have a relatively single selectivity for protecting substrates, and tend to significantly reduce the gloss of the surface of the article after stripping.

Disclosure of Invention

In order to solve the technical problems, the invention provides a composite peelable emulsion, which is prepared from the following raw materials in parts by weight (65-85): (10-25).

As a preferred technical scheme, the lowest film-forming temperature of the acrylic acid self-film-forming emulsion is not higher than 10 ℃; preferably, the minimum film forming temperature is not higher than 3 ℃.

As a preferable technical scheme of the invention, the surface tension of the acrylic acid self-film-forming emulsion is 30-35 dyne/cm.

As a preferable technical scheme, the lowest film forming temperature of the acrylic self-crosslinking emulsion is 20-30 ℃.

As a preferable technical scheme, the Brookfield viscosity of the acrylic self-crosslinking emulsion is 30-50 mPa.s.

As a preferable technical scheme, the composite strippable emulsion further comprises 1-5 wt% of hydrophobic association type thickening agent.

A second aspect of the invention provides a peelable protective coating comprising a peelable layer and a topcoat layer; the peelable layer is prepared from the composite peelable emulsion as claimed in any one of claims 1 to 6; the thickness ratio of the peelable layer to the top coat is 1: (0.7-1.4).

According to a preferable technical scheme, the preparation raw materials of the top coating comprise, by weight, 20-50 parts of elastic acrylate emulsion, 20-55 parts of filler, 0-5 parts of film forming additive, 0-2 parts of dispersant, 0-1 part of thickener, 0-5 parts of antifreeze and 25-30 parts of water.

As a preferable technical scheme, the viscosity of the elastic acrylate emulsion at 23 ℃ is 1000-6000.

The third aspect of the invention provides the application of the composite strippable emulsion in the protection of prefabricated parts or finished products in the fields of woodware, metal, glass, plastic and concrete.

The composite strippable emulsion has strong cohesive force, so that the protective coating is not easy to break in the stripping process and has no residue on the base material, and the composite strippable emulsion has moderate adhesive force with the base material, so that the composite strippable emulsion can ensure the good adhesion of a coating film to the base material, effectively protect a product from being damaged in the transportation process, can be easily stripped when the stripping is needed, does not reduce the glossiness of the surfaces of the base materials such as woodware, metal, glass, plastic, concrete and the like, and does not influence the comprehensive performance of the base material. In addition, the composite strippable emulsion can be used independently or can be compounded with a surface coating, when the surface coating is compounded, the surface coating is coated on the surface of the strippable emulsion for use, and various pigments or color pastes can be added into the surface coating formula, so that the protective products can be distinguished, different functions and purposes can be distinguished, and field sorting is easier. The composite strippable emulsion is convenient to use, can be used after being opened, can be brushed, rolled and sprayed, can clean and protect various prefabricated parts or finished products in the carrying and using processes, and prolongs the service life. In addition, compared with a PE/PP winding film, the material stripped from the composite strippable emulsion coating is environment-friendly and degradable, and does not produce environmental pollution.

Drawings

In order to more clearly illustrate the technical effects of the technical solutions in the embodiments of the present invention, the drawings required to be used in the embodiments will be briefly described below, and it should be apparent that the drawings in the following description are only the effects of the composite type peelable emulsion and the peelable protective coating in some embodiments of the present invention, and are not intended to limit the claims of the present invention. FIG. 1 is a graph showing the effects of the composite peelable emulsion of example 1 before and after peeling of a glass sheet.

FIG. 2 is a graph showing the effects of the composite peelable emulsion of example 1 before and after peeling of a cold-rolled steel sheet.

FIG. 3 is a graph showing the effects of the composite type peelable emulsion of example 1 before and after peeling of an ABS sheet.

FIG. 4 is a graph showing the effects of the composite peelable emulsion of example 1 before and after peeling of a wood board.

FIG. 5 is a graph showing the effects of the composite peelable emulsion of example 1 before and after peeling off the flat stone.

FIG. 6 is a graph showing the effects of the composite peelable emulsion of example 1 before and after peeling off irregular stone materials.

FIG. 7 is a graph showing the effects of the composite peelable emulsion of example 1 before and after peeling of a concrete base material.

FIG. 8 is a graph showing the effects of the composite releasable emulsion of example 1 before and after peeling off a substrate precoated with a 2K PU varnish.

FIG. 9 is a graph showing the effect of the peelable protective coating of example 7 before and after peeling of the wood panel.

Fig. 10 is a graph showing the effects of the peelable protective coating of example 7 before and after peeling off the flat stone.

FIG. 11 is a graph showing the protective effect of the apparatus in daily use of the peelable protective coating of example 7.

The left side of each figure is an effect figure before stripping, and the right side is an effect figure after stripping.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

Approximating language, as used herein throughout the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received for modification without substantial change in the basic function to which the invention is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

All viscosities (viscosity) in the present invention refer to viscosities measured at 25 degrees celsius, and the specific measurement method is well known to those skilled in the art.

The invention provides a composite peelable emulsion, which is prepared from the following raw materials in parts by weight (65-85): (10-25).

The acrylic acid self-film-forming emulsion is water-based acrylic acid copolymer emulsion which can automatically level on the surface of a base material at normal temperature and is solidified into a film, and is synthesized by emulsifying oily vinyl monomers in water under the initiation of a water-based free radical initiator. By adjusting the conditions of monomer types, polymerization degree, solid content and the like, the mechanical properties such as glass transition temperature, water resistance, tensile strength and the like of the acrylic self-film-forming emulsion can be changed, so that the physicochemical parameters such as the lowest film-forming temperature, surface tension and the like of the acrylic self-film-forming emulsion are effectively adjusted, and the cohesive strength and the adhesive force to a base material of the composite peelable emulsion are adjusted.

In some embodiments, the acrylic self-film-forming emulsion has a minimum film-forming temperature of no greater than 10 degrees celsius; preferably, the minimum film forming temperature is not higher than 3 ℃.

Further, the surface tension of the acrylic acid self-film-forming emulsion is 30-35 dynes/cm; preferably, the surface tension is 32 dynes/cm.

Furthermore, the Brookfield viscosity of the acrylic self-film-forming emulsion is 40-125 cps.

Further, the solid content of the acrylic self-film-forming emulsion is 45-48 wt%.

Further, the acrylic self-film-forming emulsion has a density of 1.07 g/ml.

The acrylic self-film-forming emulsions meeting the above requirements of the present invention may be prepared by emulsion polymerization, well known to those skilled in the art, or may be obtained commercially, for example, from Carboset PL-958 from Lubrizol, USA.

The acrylic acid self-crosslinking emulsion is prepared by adopting an emulsion polymerization method for acrylic acid or acrylic ester monomers, the structure of the acrylic acid self-crosslinking emulsion contains two or more than two active functional groups, the functional groups can be crosslinked and cured in a physical and chemical reaction mode, and the acrylic acid self-crosslinking emulsion is convenient to use because no additional crosslinking agent is required to be added during use. In addition, since the reactive functional groups thereof participating in the crosslinking reaction are disposed in the polymer molecular chain of the acrylic emulsion, the probability of these reactive groups being distributed on the surface of the emulsion particles or in the vicinity of the surface is increased, so that the self-crosslinking reaction is more likely to occur. The acrylic self-crosslinking emulsion of the present invention can be prepared by itself according to methods well known to those skilled in the art, such as emulsion polymerization, or can be obtained commercially.

In some embodiments, the acrylic self-crosslinking emulsion of the present invention is an aqueous acrylic self-crosslinking nano-polymer emulsion.

Further, the lowest film forming temperature of the water-based acrylic self-crosslinking nano polymer emulsion is 20-30 ℃; preferably, the minimum film forming temperature is 25 ℃.

The term "minimum film-forming temperature" in the present invention means the minimum temperature at which water in the emulsion system volatilizes and emulsion particles coagulate to form a continuous film.

In some embodiments, the aqueous acrylic self-crosslinking nano polymer emulsion has a Brookfield viscosity of 30 to 50 mPa.s; preferably, the brookfield viscosity is 40 mpa.s.

Further, the pH value of the water-based acrylic acid self-crosslinking nano polymer emulsion is 8-9.

Further, the specific gravity of the aqueous acrylic self-crosslinking nano polymer emulsion is 1.06g/cm³。

The acrylic self-film-forming emulsions meeting the above requirements of the present invention may be prepared by emulsion polymerization methods well known to those skilled in the art, or may be commercially available, for example, from POLEEN a-3020, first pull technology. The POLEEN A-3020 emulsion particles have small particle size, and under the synergistic effect with the acrylic acid self-film-forming emulsion, the emulsion has excellent base material permeability, particularly good adhesive force and efflorescence resistance on an alkaline base surface, and simultaneously further improves the cohesive strength of a coating and avoids tearing in a stripping process.

In a preferable embodiment of the invention, the composite peelable emulsion further comprises 1-5 wt% of hydrophobic association type thickening agent.

In some embodiments, the hydrophobically associative thickener is a hydrophobically modified alkali swellable associative thickener.

The hydrophobic modified alkali swelling associative thickener is a hydrophobic associative water-soluble polymer, and is a water-soluble polymer with a small amount of hydrophobic groups on a hydrophilic macromolecular chain. In the aqueous solution of the polymer, hydrophobic groups are aggregated due to hydrophobic effect, so that intramolecular and intermolecular association is generated in macromolecular chains, and the rheological property of the aqueous solution is greatly influenced. Above the critical association concentration, a supermolecular structure mainly based on intermolecular association is formed, and the hydrodynamic volume is increased, so that the composite material has better thickening property.

In some embodiments, the hydrophobically modified alkali-swellable associative thickener has a Brookfield viscosity of 3 to 8mPa.s at 25 ℃; preferably, it has a brookfield viscosity of 5mpa.s at 25 ℃.

Further, the specific gravity of the hydrophobically modified alkali-swellable associative thickener is 1.05 kg/L.

The hydrophobically associative thickeners meeting the above requirements are commercially available, for example, RHEOMAX WP-327 from first tractography.

Because the hydrophobic modified alkali swelling associative thickener of RHEOMAX WP-327 has two or more lipophilic groups on a water soluble chain with relatively low molecular weight, the hydrophobic modified alkali swelling associative thickener has the behavior of a surfactant in water and can form micelles. However, the two lipophilic groups in the molecule are not necessarily in the same micelle, and are linked to form a structure. The oleophilic group in the hydrophobically modified alkali swelling associative thickener can adsorb emulsion particles and pigment particles, which enhances the structure. Furthermore, the particles bridged by the macromolecules of the thickening agent form a physical network cross-linked structure, and the network structure can be gradually destroyed in a shearing field, so that the flowing property of the system can be controlled. Such associations are broken down at high shear rates, reducing the viscosity, and re-forming after the shear is removed, restoring the viscosity. However, the formation of the association takes time, so that the recovery of viscosity is not as fast as that of cellulose, thereby giving a certain flow time, facilitating leveling and improving gloss.

In a preferred embodiment of the invention, the composite peelable emulsion further comprises 0-1.0 wt% of a mineral oil defoaming agent, 0-0.5 wt% of a pH regulator and 5-15 wt% of water.

Further, the composite peelable emulsion comprises the following raw materials in parts by weight:

the liquid thickener is hydrophobic association type thickener. The specific components of the mineral oil defoamer in the present invention are not particularly limited, and various mineral oil defoamers known to those skilled in the art can be selected.

Further, the brookfield viscosity of the mineral oil defoamer at 23 ℃ is 200-800 mpa.s.

Mineral oil defoamers meeting the above requirements are commercially available including, but not limited to, Foamaster MO2160 from BASF.

The pH regulator is an acid-base component of a regulating system, specific components of the pH regulator are not specially limited, and the pH regulator can be conventionally selected according to needs and can regulate the pH value of the final composite strippable emulsion to be within the range of 7.5-8.5.

The preparation method of the composite peelable emulsion is not particularly limited, and the composite peelable emulsion can be mixed according to a method known by a person skilled in the art, for example, after the acrylic acid self-film-forming emulsion and the acrylic acid self-crosslinking emulsion are mixed according to a proportioning liquid, the water-mineral oil antifoaming agent and the liquid thickener are added, stirred and mixed, then the pH regulator is added, and the pH value of the regulating system is regulated to be within the range of 7.5-8.5.

The use method of the composite strippable emulsion is not specially limited, and the composite strippable emulsion can be coated on a protective base material by adopting modes of brushing, roller coating, spraying and the like, and then naturally dried and solidified. The usage amount of the emulsion or the thickness of the coating is not specially limited and can be automatically adjusted according to specific requirements.

In the invention, because the active functional groups participating in the crosslinking reaction are arranged in the polymer molecular chain of the acrylic emulsion, the probability that the active groups are distributed on the surface or near the surface of the emulsion particles is improved, and the self-crosslinking reaction is easier to occur. In addition, because the lowest film-forming temperature is low, the surface tension is small, and under the synergistic action with the acrylic acid self-film-forming emulsion, polymer chains can be mutually interpenetrated and gradually solidified into a compact film, so that the cohesive force of the coating is improved, and the conditions that the coating is broken in the glass process and the like are avoided. In addition, when the acrylic acid self-film-forming emulsion and the acrylic acid self-crosslinking emulsion with specific structures are compounded and used, the hydrophobic modified alkali swelling association type thickener and the mineral oil defoamer are matched and used, emulsion particles in a system are fully dispersed and uniformly wrapped under the interaction of the specific viscosity and the specific structures of the components, and meanwhile, enough steric hindrance can be provided for adjusting the adhesive force and the cohesive force between the coating and the base material, so that the problems that the stripping is difficult due to too strong cohesive force between the coating and the base material, the surface glossiness of the base material is reduced after stripping and the like are avoided.

On the premise of ensuring reasonable adhesion and good strippability of the composite strippable emulsion to the surface of the protective base material, the composite strippable emulsion and the surface coating can be compounded for use in order to reduce the consumption of raw materials of the strippable layer and reduce the production cost. After the composite strippable emulsion is coated on the surface of a protective base material, the protective base material is placed for a certain time (for example, 12 hours overnight), is automatically dried and cured, and then a surface coating is coated on the surface of a strippable layer formed by the composite strippable emulsion, so that the using amount of the composite strippable emulsion can be reduced, and meanwhile, the reduction of strippability can be avoided. However, applicants have found that a reasonable control of the ratio of the thickness of the peelable layer to the top coat layer is required and that too little or too much thickness of the peelable layer is detrimental to achieving good peelability and reasonable adhesion. In addition, raw material components of the surface coating are required to be correspondingly regulated and controlled, otherwise, the problems that the surface coating and the strippable layer are poor in adhesive force, the strippable protective coating is remained on the surface of the base material during stripping, or the glossiness of the base material is influenced are easily caused.

In some embodiments, the peelable layer to topcoat layer thickness ratio is 1: 1.

the thickness of the strippable protective coating is not specially limited, and can be automatically adjusted according to different and specific requirements of the protective base material. In some embodiments, the peelable protective coating has a thickness of 80 microns, wherein the peelable layer and topcoat have a thickness of 1: 1.

in some embodiments, the preparation raw materials of the top coating comprise, by weight, 20-50 parts of an elastic acrylate emulsion, 20-55 parts of a filler, 0-5 parts of a film forming assistant, 0-2 parts of a dispersant, 0-1 part of a thickener, 0-5 parts of an antifreeze agent and 25-30 parts of water.

In the present invention, the preparation method of the top coat emulsion is not particularly limited, and the top coat emulsion may be prepared by mixing according to a conventional method, for example, the elastic acrylate emulsion, the filler, the film-forming aid, the dispersant, the thickener, the anti-freeze agent, water, and the like may be used by stirring and mixing.

The elastic acrylate emulsion is characterized in that a proper amount of soft monomers are added in the process of preparing the acrylate emulsion so as to reduce the glass transition temperature of the obtained acrylate polymer, and ether bonds, ester bonds or amide groups are formed by utilizing the interaction of special functional groups carried by added functional monomers or oligomers, or C-C bonds of macromolecular chains are formed by the addition of double bonds so as to form the acrylate emulsion with a cross-linking structure.

In some embodiments, the elastic acrylate emulsion has a viscosity of 1000 to 6000 at 23 degrees Celsius. The viscosity is measured according to DIN EN ISO 2555.

Further, the lowest film forming temperature of the elastic acrylate emulsion is not higher than 3 ℃.

Further, the pH value of the elastic acrylate emulsion is 7.0-8.5.

The elastomeric acrylate emulsions of the present invention meeting the above requirements may be prepared by themselves or may be commercially available, for example, Acronal 7026G from BASF.

The filler in the invention is a component for increasing the compactness of the surface coating and reducing the consumption and cost of raw materials, the specific components of the filler are not specially limited, and various fillers known by technical personnel in the field can be selected, including but not limited to diatomite, clay, kaolin, talcum powder, barium sulfate, (heavy) calcium carbonate, silicon dioxide, water-washed kaolin, montmorillonite, asbestos fiber, glass fiber, quartz powder, quartz sand, magnetic powder, carborundum, alumina, silica gel powder, silica micropowder, stone powder, mica powder, boron fiber, carbon fiber and the like.

In some embodiments, the filler is comprised of 10 to 25 parts of water-washed kaolin clay and 15 to 30 parts of ground calcium carbonate.

The film-forming aid of the present invention is a component that helps the peelable protective coating of the present invention to spread more quickly and evaporate quickly to aid in film formation, and various film-forming aids known to those skilled in the art can be used, including, but not limited to, 2, 4-trimethyl-1, 3-pentanediol monoisobutyrate, propylene glycol butyl ether, propylene glycol methyl ether acetate, alcohol ester dodeca, ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, hexylene glycol butyl ether acetate, ethyl 3-ethoxypropionate, dicyclopentenyloxyethyl acrylate, diisopropanol adipate, etc.

The dispersant in the present invention is an ingredient that helps to adequately disperse the components of the top coating system, such as fillers, film forming aids, anti-freeze agents, thickeners, etc., in water, and can be selected from various surfactants known to those skilled in the art, including but not limited to anionic surfactants, cationic surfactants, nonionic surfactants, etc., including but not limited to ammonium acrylate dispersants.

The thickener in the present invention is a component for adjusting viscosity and consistency of the rust inhibitive paint system, and can be selected from the components known to those skilled in the art, including but not limited to xanthan gum, cellulose, arabic gum, phenolic resin, microcrystalline wax, etc.

The antifreeze in the invention is also called as a freezing inhibitor, and is a substance which is added into other liquid (generally water) to reduce the freezing point and improve the freezing resistance. The specific components are not particularly limited, and various antifreeze components known to those skilled in the art, such as ethylene glycol, propylene glycol, glycerin, isopropyl alcohol, etc., can be selected.

The present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.

Examples

Example 1: the composite strippable emulsion is prepared from the following raw materials in parts by weight:

the acrylic acid self-film-forming emulsion is Carboset PL-958 of Lubrizol; the acrylic acid self-crosslinking emulsion is POLEEN A-3020 in the first-hand-pulling technology; the mineral oil defoamer is Foamaster MO2160 from BASF; the liquid thickener is a hydrophobic modified alkali swelling association type thickener of RHEOMAX WP-327 in the first traction technology.

And mixing the acrylic acid self-film-forming emulsion and the acrylic acid self-crosslinking emulsion according to a ratio, adding a mineral oil defoamer and a liquid thickener, stirring and mixing, adding a pH regulator, and regulating the pH value of a system to be within the range of 7.5-8.5 to obtain the composite strippable emulsion.

The composite peelable emulsion in the example has the viscosity of 2040mPa.s, the pH value of 7.95 and the solid content of 41 which are measured according to the GB/T11175-2002 standard, the specific gravity of 1.0843 which is measured according to the GBT 6750-2007 standard and the lowest film forming temperature of about 1 ℃ which is measured according to the GB-T9267-1988 standard.

Example 2: the composite strippable emulsion is prepared from the following raw materials in parts by weight:

Example 3: the composite strippable emulsion is prepared from the following raw materials in parts by weight:

the acrylic acid self-film-forming emulsion is Carboset PL-958 of Lubrizol; the acrylic acid self-crosslinking emulsion is E-1208 of Fushan City and Yu Gao New materials science and technology Co., Ltd; the mineral oil defoamer is FoamasterMO 2160 from BASF; the liquid thickener is a hydrophobic modified alkali swelling association type thickener of RHEOMAX WP-327 in the first traction technology.

Example 4: the composite strippable emulsion is prepared from the following raw materials in parts by weight:

the acrylic acid self-film-forming emulsion is PD-2 pure acrylic emulsion (with the viscosity (200-2000 mP. s, the lowest film-forming temperature of 23 +/-1 ℃ and the solid content of 48 +/-1 percent) of Shandong Baoda new material Co., Ltd.), the acrylic acid self-crosslinking emulsion is POLEEN A-3020 of first-tech, the mineral oil antifoaming agent is Foamaster MO2160 of BASF, and the liquid thickening agent is RHEOMAX WP-327 hydrophobic modified alkali swelling association thickening agent of first-tech.

Example 5: the composite strippable emulsion is prepared from the following raw materials in parts by weight:

the acrylic acid self-film-forming emulsion is Carboset PL-958 of Lubrizol; the acrylic acid self-crosslinking emulsion is POLEEN A-3020 in the first-hand-pulling technology; the mineral oil defoamer is Foamaster MO2160 from BASF; the liquid thickener is R-705 polyether type polyurethane thickener (effective component 40 +/-1 percent, viscosity 4000/mP. s) of ten thousand new materials Co., Ltd.

Example 6: the composite strippable emulsion is prepared from the following raw materials in parts by weight:

the acrylic acid self-film-forming emulsion is Carboset PL-958 of Lubrizol; the acrylic acid self-crosslinking emulsion is POLEEN A-3020 in the first-hand-pulling technology; the defoaming agent is DT-650 (viscosity 1000-3000 mP. s) of south sea field chemical company Limited in Fushan city; the liquid thickener is a hydrophobic modified alkali swelling association type thickener of RHEOMAX WP-327 in the first traction technology.

Example 7: a peelable protective coating is provided comprising a peelable layer and a topcoat layer; the peelable layer is prepared from the following composite peelable emulsion; the total thickness of the peelable protective coating is about 80 microns, wherein the thickness ratio of the peelable layer to the top coating is 1: 1;

the composite strippable emulsion comprises the following raw materials in parts by weight:

The preparation raw materials of the top coating comprise, by weight, an elastic acrylate emulsion 35, a filler 43, a film-forming aid 2, a dispersant 1.0, a thickener 0.3, a color paste 1 and water 28.

The elastic acrylate emulsion is Acronal 7026G from BASF; the filler consists of 18 parts of water-washed kaolin (S-2 of Taihe mining Co., Ltd., Fushan city) and 25 parts of heavy calcium carbonate; the film-forming auxiliary agent is dipropyl alcohol butyl ether; the dispersant is an acrylic acid ammonium salt dispersant; the thickener is a cellulose thickener.

The strippable protective coating is obtained by coating the composite strippable emulsion on the surface of a protective base material, standing for 12 hours overnight, automatically airing and curing, and then coating a surface coating on the surface of a strippable layer formed by the composite strippable emulsion.

Example 8: a peelable protective coating is provided comprising a peelable layer and a topcoat layer; the peelable layer is prepared from the following composite peelable emulsion; the total thickness of the peelable protective coating is about 80 microns, wherein the thickness ratio of the peelable layer to the top coating is 1: 1;

The elastic acrylate emulsion is PD-2 pure acrylic emulsion (with viscosity (200-2000 mP. S, the lowest film forming temperature of 23 +/-1 ℃ and solid content of 48 +/-1%) of Shandongboda new material company Limited, the filler is composed of 18 parts of water-washed kaolin (S-2 of Taihe mining company Limited in Fushan) and 25 parts of heavy calcium carbonate, the film forming auxiliary agent is dipropyl alcohol butyl ether, the dispersing agent is an acrylic acid ammonium salt dispersing agent, and the thickening agent is a cellulose thickening agent.

Example 9: the composite strippable emulsion is prepared from the following raw materials in parts by weight:

the acrylic acid self-film-forming emulsion is Carboset PL-958 of Lubrizol; the acrylic acid self-crosslinking emulsion is POLEEN A-3020 in the first-hand-pulling technology; the mineral oil defoamer is Foamaster MO2160 from BASF; the RHEOMAX WP-327 hydrophobic modified alkali swelling association type thickener of the liquid thickener first traction technology comprises talcum powder and calcium carbonate in equal weight.

And mixing the acrylic acid self-film-forming emulsion and the acrylic acid self-crosslinking emulsion according to a ratio, adding a mineral oil defoamer, a liquid thickener and a filler, stirring and mixing, adding a pH regulator, and regulating the pH value of a system to be within a range of 7.5-8.5 to obtain the composite strippable emulsion.

Performance testing

1. Peel performance on different substrates: completely and easily stripped, a paint film is not damaged, and the record of no residue of a substrate is grade 1; almost completely stripping, no residue on the substrate, a small amount of damage to the paint film, and recording as level 2 with large force; stripping is laborious, the paint film solution is broken, and a small amount of residue on the substrate is recorded as grade 3; peeling was possible but difficult, with a large amount of residue on the substrate recorded as grade 4; hardly peeled off, and the paint film adhesion was well recorded as grade 5. The composite strippable emulsion in the embodiment 1 is respectively coated on a glass plate, a cold-rolled steel plate, an ABS (acrylonitrile butadiene styrene) plate, a wood plate + composite coating and precoated with 2K PU (polyurethane), the thickness is 70-100 micrometers, and the stripping grades are all 1 grade; respectively coating the composite strippable emulsion in the embodiment 1 on flat stone, irregular stone and a flat stone + composite coating, wherein the thickness is 80-120 micrometers, and the stripping grades are all 1 grade; the composite strippable emulsion in the embodiment 1 is coated on concrete, the thickness of the composite strippable emulsion is 100-150 micrometers, and the stripping grades are all 2 grades. The gloss of the composite peelable emulsion of example 1 before and after coating the composite peelable emulsion on a wood board and a substrate precoated with 2K PU varnish is shown in table 1 below:

TABLE 1 gloss measurement before and after peeling

Further, the composite type peelable emulsions of examples 1 to 6 were coated on wood boards and 2K PU coatings, and the peel grades and the gloss (60 degree gloss) of the peeled substrates were observed, and the results are shown in table 2 below.

TABLE 2 Performance test Table

In addition, the applicant also applied the strippable protective coatings of examples 7 and 8 to the surfaces of wood boards and flat stone materials and observed the stripping grade and the gloss of the substrate surface before and after stripping. The peeling grade of the example 7 reaches grade 1, the peeling of the peelable protective coating of the example 8 is more laborious, the paint film solution is broken, the substrate has a little residue, the grade is 3, the glossiness of the peelable protective coating of the example 7 is basically not changed before and after peeling off the surface of the wood board or the flat stone, and the glossiness of the peelable protective coating of the example 8 is obviously reduced after peeling off.

As can be seen from the table, the composite peelable emulsion and the peelable protective coating have good adhesion and excellent peelable property, and do not remain on the surface of the base material after peeling, and do not affect the surface gloss and other properties of the base material after peeling.

In addition, the daily used instruments and equipment can achieve the effects of cleaning and protection by coating the composite strippable emulsion, and the surfaces of the instruments and equipment can be protected from being damaged by pollution sources, and the effect is shown in fig. 11.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. However, the present invention is not limited to the embodiments described above, and modifications, equivalent changes and modifications, may be made without departing from the spirit of the present invention.

Claims

1. The composite strippable emulsion is characterized by comprising the following raw materials in parts by weight: (10-25).

2. The composite peelable emulsion of claim 1 wherein the acrylic self-film forming emulsion has a minimum film forming temperature of no more than 10 degrees celsius; preferably, the minimum film forming temperature is not higher than 3 ℃.

3. The composite peelable emulsion according to claim 1, wherein the acrylic self-film forming emulsion has a surface tension of 30 to 35 dynes/cm.

4. The composite peelable emulsion according to any one of claims 1 to 3, wherein the minimum film forming temperature of the acrylic self-crosslinking emulsion is 20 to 30 ℃.

5. The composite peelable emulsion of claim 4, wherein the acrylic self-crosslinking emulsion has a Brookfield viscosity of from 30 to 50 mPa.s.

6. The composite peelable emulsion according to any one of claims 1 to 3, further comprising 1 to 5 wt% of a hydrophobic associative thickener.

7. A peelable protective coating comprising a peelable layer and a top coat layer; the peelable layer is prepared from the composite peelable emulsion as claimed in any one of claims 1 to 6; the thickness ratio of the peelable layer to the top coat is 1: (0.7-1.4).

8. The peelable protective coating according to claim 7, wherein the top coating comprises 20 to 50 parts by weight of an elastic acrylate emulsion, 20 to 55 parts by weight of a filler, 0 to 5 parts by weight of a film forming aid, 0 to 2 parts by weight of a dispersant, 0 to 1 part by weight of a thickener, 0 to 5 parts by weight of an antifreeze agent, and 25 to 30 parts by weight of water.

9. The peelable protective coating according to claim 8 wherein the elastic acrylate emulsion has a viscosity of 1000 to 6000 at 23 degrees celsius.

10. The use of the composite peelable emulsion according to any one of claims 1 to 6 in the protection of prefabricated parts or finished products in the fields of wood, metal, glass, plastic, concrete.