High-water-whitening-resistance polyacrylate emulsion protective film glue as well as preparation method and application thereof

Abstract

The invention discloses high-water-whitening-resistance polyacrylate emulsion protective film glue as well as a preparation method and application thereof, and relates to the technical field of functional water-based polymer materials. The water-whitening-resistant polyacrylate emulsion protective film glue is prepared from the following raw material components in parts by mass: 5.0 to 20.0 parts of a soft core component, 5.0 to 25.0 parts of a hard middle layer component, 15.0 to 35.0 parts of a soft shell component, 0.5 to 4.0 parts of an emulsifier, 0.1 to 2.0 parts of an initiator and 20.0 to 65.0 parts of deionized water, the component of the soft core is butyl latex, and the component of the hard middle layer is one or a composition of more of methyl methacrylate, methyl acrylate, ethyl acrylate, styrene or butyl methacrylate. And the soft shell component is a composition of one or more of butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, hexadecyl acrylate or octadecyl acrylate. The protective film glue disclosed by the invention has remarkable water whitening resistance and excellent comprehensive performance.

Description

Technical Field

[0001] The invention relates to the technical field of functional water-based polymer materials, in particular to a highly water-resistant white polyacrylate emulsion protective film glue and a preparation method and application thereof. Background Art

[0002] Surface protection film is a thin film material used to protect the outer surface of the product. It is mainly prepared by coating a layer of protective film glue on a polymer plastic film. It can effectively prevent the surface of the protected substrate from being scratched, contaminated and corroded during processing, transportation, storage and use. For example, the surfaces of various commercially available plastic boards, earth-covered boards, stainless steel boards and aluminum alloy boards need to be attached with a layer of surface protection film. At the same time, it can not change the appearance and performance of the protected product, and it is also simple and easy to remove, and will not cause pollution, damage and other adverse effects on the protected product. Therefore, protective film is widely used in many fields such as electronic products, furniture and building materials.

[0003] Research and a lot of time have shown that protective film glue is the core key to determining surface protective film. Its outstanding feature is that it has both bonding and peeling properties. At present, most protective film glues are based on resins such as rubber, polyacrylic acid, polyurethane and silicone, and traditional oily protective film glues have been replaced by water-based protective film glues due to their huge environmental load and harm to the human body. Among them, water-based polyacrylate emulsion protective film glue has been widely used in the production of surface protective films because it uses water as a dispersion medium, is safe and environmentally friendly, and has excellent product performance.

[0004] Water-based polyacrylate emulsion protective film adhesive refers to the use of emulsion polymerization to copolymerize different soft and hard acrylic and methacrylic monomers, and then add a certain amount of additives to the prepared emulsion with good performance. It has many advantages, such as a wide range of convenient material sources, simple preparation process, strong controllability, good transparency, and different emulsion adhesives can be prepared according to various monomer ratios for bonding various substrates, and it has excellent resistance. However, in its preparation process, water-soluble initiators, surfactants, and additives are introduced to make the water resistance poor, and when the surface protective film comes into contact with water, small water capsules with different refractive indexes from the film will be produced due to water absorption, so light is scattered at the interface, making it look white and affecting the appearance and performance of the surface protective film. This is the water whitening problem that the surface protective film industry is currently concerned about. In the actual process, surface protection often inevitably comes into contact with water, so the poor water whitening resistance of the surface protective film has become one of the important challenges affecting the appearance and performance of its products. In addition, small molecule emulsifiers are easy to migrate to the interface between the two phases during the emulsion film formation process, which will also lead to problems such as slow film formation speed, poor water resistance and poor adhesion. Therefore, the water-whitening resistance of polyacrylate emulsion protective film glue commonly used in surface protective films on the market is mostly not ideal.

[0005] In summary, the water whitening resistance achieved by the surface protection film is not ideal, and there is still room for improvement in terms of adhesion performance, peeling performance and economic performance. Summary of the invention

[0006] The purpose of the present invention is to provide a highly water-resistant white polyacrylate emulsion protective film glue and a preparation method and application thereof, so as to solve the problems existing in the above-mentioned prior art.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] One of the technical solutions of the present invention is to provide a water-resistant white polyacrylate emulsion protective film glue, comprising the following raw material components in parts by weight:

[0009] 5.0-20.0 parts of soft core component, 5.0-25.0 parts of hard middle layer component, 15.0-35.0 parts of soft shell component, 0.5-4.0 parts of emulsifier, 0.1-2.0 parts of initiator and 20.0-65.0 parts of deionized water;

[0010] The soft core component is butyl latex;

[0011] The hard intermediate layer component is a combination of one or more of methyl methacrylate, methyl acrylate, ethyl acrylate, styrene or butyl methacrylate;

[0012] The soft shell component is a combination of one or more of butyl acrylate, isooctyl acrylate, methacrylic acid, hexadecyl acrylate or octadecyl acrylate.

[0013] Furthermore, the hard intermediate layer component is a composition of methyl methacrylate and butyl methacrylate; the mass ratio of methyl methacrylate to butyl methacrylate is 8.0-15.0:5.0-10.0.

[0014] Furthermore, the soft shell component is a composition of butyl acrylate, isooctyl acrylate, octadecyl acrylate and methacrylic acid; the mass ratio of butyl acrylate, isooctyl acrylate, octadecyl acrylate and methacrylic acid is 10.0-15.0:5.0-10.0:3.0-5.0:1.0-2.0.

[0015] Furthermore, the butyl latex includes butadiene-isoprene latex (LE-50, Lear), styrene-butadiene latex (L8242, Syntema), nitrile latex (Aquanox Elite, Safe) or carboxylated styrene-butadiene latex (PC-798, Fuyang Shuangju).

[0016] More preferred is butadiene-isoprene latex (LE-50, Lear) or styrene-butadiene latex (L8242, Syntema).

[0017] Furthermore, the emulsifier is a combination of one or more of nonylphenol oxyethylene ether sulfate ammonium salt, alkyl alcohol alkoxylated sulfate sodium salt, nonylphenol ethoxylated sulfate ammonium salt, alkyl alcohol ethoxylated sulfate sodium salt, sodium dodecyl sulfate, and sodium vinyl sulfonate.

[0018] The emulsifier is preferably a composition of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and sodium vinyl sulfonate; more preferably a composition of nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and sodium vinyl sulfonate in a mass ratio of 1:3.

[0019] Furthermore, the initiator is one of ammonium persulfate, potassium persulfate or sodium persulfate, more preferably ammonium persulfate.

[0020] The second technical solution of the present invention is to provide the above-mentioned water-resistant white polyacrylate emulsion protective film glue, including the following raw material components in parts by weight:

[0021] 8.0-15.0 parts of soft core component, 10.0-25.0 parts of hard middle layer component, 19.0-33.0 parts of soft shell component, 1.5-3.0 parts of emulsifier, 0.45-0.7 parts of initiator, and 30.0-55.0 parts of deionized water.

[0022] The highly water-resistant white polyacrylate emulsion protective film glue is a three-layer functional modified polyacrylate emulsion with a sandwich structure of "soft core-hard middle layer-soft shell", specifically a multi-polymer of butyl latex and acrylic soft, hard and functional monomers;

[0023] In the present invention, a highly water-resistant white polyacrylate emulsion protective film glue is prepared by copolymerizing butadiene-isoprene latex, methyl methacrylate, butyl methacrylate, butyl acrylate, isooctyl acrylate, octadecyl acrylate, and methacrylic acid, and has a structure of formula (I):

[0024]

[0025] The third technical solution of the present invention is to provide a method for preparing the above-mentioned water-resistant white polyacrylate emulsion protective film glue, which is prepared by pre-emulsification emulsion polymerization.

[0026] Technical solution 4 of the present invention: Provide a method for preparing the above-mentioned water-resistant white polyacrylate emulsion protective film glue, comprising the following steps:

[0027] Mixing the hard intermediate layer component with part of the emulsifier, part of the initiator and part of water to obtain a hard intermediate layer pre-emulsion;

[0028] The soft shell component is mixed with the remaining amount of the emulsifier, part of the initiator and part of water to obtain a soft shell pre-emulsion;

[0029] The soft core component is mixed with the remaining initiator, the remaining water, the hard intermediate layer pre-emulsion and the soft shell pre-emulsion to react, so as to obtain the water-resistant white polyacrylate emulsion protective film glue.

[0030] The more preferred preparation steps of the present invention are as follows:

[0031] First, nonylphenol polyoxyethylene ether ammonium sulfate (CO436) and 10% deionized water are added to the pre-emulsification kettle 1, and then 40% ammonium persulfate initiator (dissolved in an appropriate amount of water) is added, stirred for 5 minutes, and then the hard middle layer components (methyl methacrylate, butyl methacrylate) are added in turn, and stirred for 1 hour to obtain the hard middle layer pre-emulsion 1; secondly, sodium vinyl sulfonate and 15% deionized water are added to the pre-emulsification kettle 2, and then 50% ammonium persulfate initiator (dissolved in an appropriate amount of water) is added, stirred for 5 minutes, and then the soft core components (butyl acrylate, isooctyl acrylate, octadecyl acrylate, methacrylic acid) are added in turn, and stirred for 1 hour. Get soft shell pre-emulsion 2; finally, add the remaining deionized water into the polymerization reactor, stir and heat to 80°C, add soft core butyl latex and 10% ammonium persulfate initiator (dissolved in appropriate amount of water first), react for 0.5h, then add hard middle layer pre-emulsion dropwise, control the hard middle layer pre-emulsion addition time to be controlled at 1.0h, continue to react for 0.5h after the hard middle layer pre-emulsion addition is completed, then start to add soft shell pre-emulsion dropwise, and control the addition time to be controlled at 1.0h, after the addition is completed, heat to 86°C, keep warm for 1h, then cool to 50°C, adjust pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain highly water-resistant white polyacrylate emulsion protective film glue.

[0032] The fifth technical solution of the present invention is to provide the application of the above-mentioned water-resistant white polyacrylate emulsion protective film glue as a surface protection material, which is specifically used in protective films in the fields of aluminum profiles, aluminum-plastic panels, carbon profiles, and plastic profiles.

[0033] The present invention discloses the following technical effects:

[0034] (1) The present invention obtains a three-layer functional modified polyacrylate emulsion with a sandwich structure of "soft core-hard middle layer-soft shell" through polymer structure design, and then uses it as a protective film glue to show excellent water whitening resistance.

[0035] (2) The highly water-resistant polyacrylate emulsion protective film glue obtained by the present invention effectively utilizes the unsaturated double bonds in butyl latex to emulsion polymerize with acrylic soft, hard and functional monomers, effectively chemically bonds the butyl rubber system and the acrylate system, and together gives the protective film glue the water-resistant whitening performance, while also effectively improving the water resistance of the system. In addition, the 180-degree peel strength growth problem of the acrylic emulsion pressure-sensitive glue is effectively suppressed.

[0036] (3) The highly water-resistant white polyacrylate emulsion protective film glue of the present invention can meet the needs of different application fields by optimizing and regulating the ratio and composition of the raw materials.

[0037] (4) The highly water-resistant white polyacrylate emulsion protective film glue of the present invention does not involve organic solvents such as acetone and xylene, and no other small organic molecules are released during the curing process. It is green and environmentally friendly and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 The water whitening resistance test diagram of the polyacrylate emulsion protective film glue prepared in Comparative Example 1 and Comparative Example 2 of the present invention, (a) is Comparative Example 1 (1h), (b) is Comparative Example 1 (24h), and (c) is Comparative Example 2 (24h);

[0040] Figure 2 The water whitening resistance performance test diagram of the highly water-resistant polyacrylate emulsion protective film glue of Examples 1-3 of the present invention, (a) is Example 1 (24h), (b) is Example 2 (24h), and (c) is Example 3 (24h);

[0041] Figure 3 The water whitening resistance performance test diagram of the highly water-resistant polyacrylate emulsion protective film glue of Examples 4-6 of the present invention, (a) is Example 4 (24h), (b) is Example 5 (24h), and (c) is Example 6 (24h);

[0042] Figure 4 The water whitening resistance performance test diagram of the highly water-resistant polyacrylate emulsion protective film glue of Examples 7-9 of the present invention, (a) is Example 7 (24h), (b) is Example 8 (24h), and (c) is Example 9 (24h);

[0043] Figure 5 The water whitening resistance performance test diagram of the highly water-resistant polyacrylate emulsion protective film glue of Examples 10-12 of the present invention, (a) is Example 10 (24h), (b) is Example 11 (24h), and (c) is Example 12 (24h); DETAILED DESCRIPTION

[0044] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0045] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0046] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0047] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0048] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0049] Example 1

[0050] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0051] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0052] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0053] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80°C, add 8.0 kg of butadiene-isoprene latex (LE-50, Lier) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add hard intermediate layer pre-emulsion 1 dropwise, control the dropping time to 1.0 h, continue to react for 0.5 h after the hard intermediate layer pre-emulsion is added, and then start to add soft shell pre-emulsion 2 dropwise, control the dropping time to 1.0 h, after the addition is completed, heat to 86°C, keep warm for 1 h, then cool to 50°C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain a highly water-resistant white polyacrylate emulsion protective film glue with the structure shown in formula (I).

[0054] Example 2

[0055] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0056] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0057] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0058] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80°C, add 12.0 kg of butadiene-isoprene latex (LE-50, Lier) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add hard intermediate layer pre-emulsion 1 dropwise, control the dropping time to 1.0 h, continue to react for 0.5 h after the hard intermediate layer pre-emulsion is added, and then start to add soft shell pre-emulsion 2 dropwise, control the dropping time to 1.0 h, after the addition is completed, heat to 86°C, keep warm for 1 h, then cool to 50°C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain highly water-resistant white polyacrylate emulsion protective film glue.

[0059] Example 3

[0060] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0061] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0062] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0063] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80°C, add 15.0 kg of butadiene-isoprene latex (LE-50, Lier) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add hard intermediate layer pre-emulsion 1 dropwise, control the dropping time to 1.0 h, continue to react for 0.5 h after the hard intermediate layer pre-emulsion is added, and then start to add soft shell pre-emulsion 2 dropwise, control the dropping time to 1.0 h, after the addition is completed, heat to 86°C, keep warm for 1 h, then cool to 50°C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain highly water-resistant white polyacrylate emulsion protective film glue.

[0064] Example 4

[0065] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0066] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0067] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0068] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80 ° C, add 8.0 kg of styrene-butadiene latex (L8242, Xintema) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add hard intermediate layer pre-emulsion 1 dropwise, control the dropping time to 1.0 h, continue to react for 0.5 h after the hard intermediate layer pre-emulsion is added, and then start to add soft shell pre-emulsion 2 dropwise, control the dropping time to 1.0 h, after the addition is completed, heat to 86 ° C, keep warm for 1 h, then cool to 50 ° C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain highly water-resistant white polyacrylate emulsion protective film glue.

[0069] Example 5

[0070] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0071] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0072] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0073] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80 ° C, add 12.0 kg of styrene-butadiene latex (L8242, Xintema) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add the hard intermediate layer pre-emulsion 1 dropwise, and control the dropping time to 1.0 h. After the hard intermediate layer pre-emulsion is added, continue to react for 0.5 h, and then start to add the soft shell pre-emulsion 2 dropwise, and control the dropping time to 1.0 h. After the addition is completed, heat to 86 ° C, keep warm for 1 h, then cool to 50 ° C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain a highly water-resistant white polyacrylate emulsion protective film glue.

[0074] Example 6

[0075] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0076] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0077] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0078] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80 ° C, add 15.0 kg of styrene-butadiene latex (L8242, Xintema) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add the hard intermediate layer pre-emulsion 1 dropwise, and control the dropping time to 1.0 h. After the hard intermediate layer pre-emulsion is added, continue to react for 0.5 h, and then start to add the soft shell pre-emulsion 2 dropwise, and control the dropping time to 1.0 h. After the addition is completed, heat to 86 ° C, keep warm for 1 h, then cool to 50 ° C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain a highly water-resistant white polyacrylate emulsion protective film glue.

[0079] Example 7

[0080] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0081] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 15 kg of methyl methacrylate and 5 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0082] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0083] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80°C, add 12.0 kg of butadiene-isoprene latex (LE-50, Lier) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add hard intermediate layer pre-emulsion 1 dropwise, control the dropping time to 1.0 h, continue to react for 0.5 h after the hard intermediate layer pre-emulsion is added, and then start to add soft shell pre-emulsion 2 dropwise, control the dropping time to 1.0 h, after the addition is completed, heat to 86°C, keep warm for 1 h, then cool to 50°C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain highly water-resistant white polyacrylate emulsion protective film glue.

[0084] Example 8

[0085] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0086] (1) 0.5 kg of CO436 emulsifier and 7.5 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10 kg of methyl methacrylate and 10 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain a hard intermediate layer pre-emulsion 1;

[0087] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0088] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80°C, add 12.0 kg of butadiene-isoprene latex (LE-50, Lier) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add hard intermediate layer pre-emulsion 1 dropwise, control the dropping time to 1.0 h, continue to react for 0.5 h after the hard intermediate layer pre-emulsion is added, and then start to add soft shell pre-emulsion 2 dropwise, control the dropping time to 1.0 h, after the addition is completed, heat to 86°C, keep warm for 1 h, then cool to 50°C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain highly water-resistant white polyacrylate emulsion protective film glue.

[0089] Example 9

[0090] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0091] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0092] (2) 1.5 kg of sodium vinyl sulfonate and 9.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of butyl acrylate, 10.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0093] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80°C, add 12.0 kg of butadiene-isoprene latex (LE-50, Lier) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add hard intermediate layer pre-emulsion 1 dropwise, control the dropping time to 1.0 h, continue to react for 0.5 h after the hard intermediate layer pre-emulsion is added, and then start to add soft shell pre-emulsion 2 dropwise, control the dropping time to 1.0 h, after the addition is completed, heat to 86°C, keep warm for 1 h, then cool to 50°C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain highly water-resistant white polyacrylate emulsion protective film glue.

[0094] Example 10

[0095] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0096] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0097] (2) 1.5 kg of sodium vinyl sulfonate and 9.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 5.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0098] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80°C, add 12.0 kg of butadiene-isoprene latex (LE-50, Lier) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add hard intermediate layer pre-emulsion 1 dropwise, control the dropping time to 1.0 h, continue to react for 0.5 h after the hard intermediate layer pre-emulsion is added, and then start to add soft shell pre-emulsion 2 dropwise, control the dropping time to 1.0 h, after the addition is completed, heat to 86°C, keep warm for 1 h, then cool to 50°C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain highly water-resistant white polyacrylate emulsion protective film glue.

[0099] Embodiment 11

[0100] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0101] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 10.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0102] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0103] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80 ° C, add 12.0 kg of styrene-butadiene latex (L8242, Xintema) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add the hard intermediate layer pre-emulsion 1 dropwise, and control the dropping time to 1.0 h. After the hard intermediate layer pre-emulsion is added, continue to react for 0.5 h, and then start to add the soft shell pre-emulsion 2 dropwise, and control the dropping time to 1.0 h. After the addition is completed, heat to 86 ° C, keep warm for 1 h, then cool to 50 ° C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain a highly water-resistant white polyacrylate emulsion protective film glue.

[0104] Example 12

[0105] A highly water-resistant white polyacrylate emulsion protective film glue is prepared by the following steps:

[0106] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the hard intermediate layer pre-emulsion 1;

[0107] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 5.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain a soft shell pre-emulsion 2;

[0108] (3) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80 ° C, add 12.0 kg of styrene-butadiene latex (L8242, Xintema) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add the hard intermediate layer pre-emulsion 1 dropwise, and control the dropping time to 1.0 h. After the hard intermediate layer pre-emulsion is added, continue to react for 0.5 h, and then start to add the soft shell pre-emulsion 2 dropwise, and control the dropping time to 1.0 h. After the addition is completed, heat to 86 ° C, keep warm for 1 h, then cool to 50 ° C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain a highly water-resistant white polyacrylate emulsion protective film glue.

[0109] Comparative Example 1

[0110] A polyacrylate emulsion protective film glue, the preparation steps are as follows:

[0111] (1) 0.5 kg of CO436 emulsifier and 5.0 kg of deionized water were added to the pre-emulsification kettle 1, followed by the addition of 0.1 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate and 5.0 kg of butyl methacrylate were added in sequence, stirred for 1 h, to obtain the pre-emulsion 1;

[0112] (2) 1.5 kg of sodium vinyl sulfonate and 7.5 kg of deionized water were added to the pre-emulsification kettle 2, followed by the addition of 0.15 kg of ammonium persulfate initiator (previously dissolved in 0.05 kg of water), stirred for 5 min, and then 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain pre-emulsion 2;

[0113] (3) Add 25 kg of deionized water to the polymerization reactor, stir and heat to 80°C, start to drip pre-emulsion 1, control the dripping time to 1.0 h, continue to react for 0.5 h after the hard intermediate layer pre-emulsion is added, and then start to drip pre-emulsion 2, control the dripping time to 1.0 h. After the addition is completed, heat to 86°C, keep warm for 2 h, then cool to 50°C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain polyacrylate emulsion protective film glue.

[0114] Comparative Example 2

[0115] A polyacrylate emulsion protective film glue, the preparation steps are as follows:

[0116] (1) 0.5 kg of CO436 emulsifier, 1.5 kg of sodium vinyl sulfonate emulsifier and 12.5 kg of deionized water were added to a pre-emulsification kettle, followed by the addition of 0.2 kg of ammonium persulfate initiator (previously dissolved in 0.1 kg of water), stirred for 5 min, and then 10.0 kg of methyl methacrylate, 5.0 kg of butyl methacrylate, 12.0 kg of butyl acrylate, 8.0 kg of isooctyl acrylate, 3.0 kg of octadecyl acrylate and 1.0 kg of methacrylic acid were added in sequence, stirred for 1 h, to obtain pre-emulsion 1;

[0117] (2) Add 35 kg of deionized water to the polymerization reactor, stir and heat to 80°C, add 12.0 kg of butadiene-isoprene latex (LE-50, Lier) and 0.05 kg of ammonium persulfate initiator (dissolved in 0.05 kg of water first), react for 0.5 h, then add pre-emulsion 1 dropwise, control the dropping time to 2.0 h, raise the temperature to 86°C after the addition is completed, keep the temperature for 2 h, then cool to 50°C, adjust the pH value to weak alkalinity with ammonia water, filter and remove impurities to obtain polyacrylate emulsion protective film glue.

[0118] Performance Testing

[0119] The performance test includes two parts. The first is the basic physical and chemical performance test, which mainly includes appearance, gel condition, stability, emulsion particle size and distribution, etc. The basic physical and chemical performance results are shown in Table 1. The second is the bonding performance test, which mainly includes initial adhesion, sustained adhesion and 180o peel strength performance tests. The initial adhesion is tested according to GB / T4852-2002 to test the initial adhesion performance of the pressure-sensitive tape, the 180o peel strength is tested according to GB / T2792-1998 to test the 180o peel strength of the pressure-sensitive tape, and the sustained adhesion is tested according to GB / T4851-1998 to test the shear resistance of the pressure-sensitive tape. The bonding performance results are shown in Table 2. Finally, there are water whitening resistance and water resistance tests. Among them, the water whitening resistance is mainly to immerse the protective film coated with glue in water, and observe the whitening after immersion for 1h, 6h, 12h and 24h. The water whitening resistance test results are shown in Tables 3 and Figure 1As shown; the water absorption test mainly involves immersing the coating film after the glue is dried in water, and testing the water absorption at 24h, 48h and 72h respectively. The water absorption test results are shown in Table 4.

[0120] Table 1 Physical and chemical properties

[0121]

[0122] Table 2 Adhesion performance

[0123]

[0124]

[0125] The basic physical and chemical performance test results show that there is basically no gel in the preparation process of the highly water-resistant white polyacrylate emulsion of the present invention, the solid content is controlled at 50±1%, the emulsion has good stability, no stratification after being placed for six months, and the particle size is 170-200nm, and the particle size distribution is also narrow; in addition, the viscosity of the emulsion is basically lower than 100mPa.s (rotor No. 2*60 speed), so it is very suitable for use as glue for protective film coating. Secondly, the bonding performance test results further show that the highly water-resistant white polyacrylate emulsion protective film glue of the present invention has excellent initial adhesion, 180o peel strength and lasting adhesion, that is, excellent bonding performance.

[0126] Table 3 Water whitening resistance

[0127]

[0128]

[0129] The water whitening resistance test results show that the highly water whitening resistant polyacrylate emulsion protective film glue of the present invention has significant water whitening resistance. This is because the present invention uses butyl latex as the soft core layer, and then separately regulates the acrylic soft, hard and functional monomers through core-shell emulsion polymerization to prepare a "soft core-hard middle layer-soft shell" three-layer modified polyacrylate emulsion with a sandwich structure. It is precisely because the present invention effectively chemically bonds the butyl rubber system and the acrylate system, which together give the protective film glue significant water whitening resistance.

[0130] Table 4 Water absorption

[0131]

[0132] Finally, the water absorption rate of the latex film is another very important factor affecting its light transmittance. The water absorption rate test of the latex film of the present invention shows that the polyacrylate emulsion protective film glue prepared by the present invention has high water whitening resistance.

[0133] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A water-resistant white polyacrylate emulsion protective film glue, characterized in that: The invention comprises the following raw material components in parts by weight: 5.0-20.0 parts of soft core component, 5.0-25.0 parts of hard middle layer component, 15.0-35.0 parts of soft shell component, 0.5-4.0 parts of emulsifier, 0.1-2.0 parts of initiator and 20.0-65.0 parts of deionized water; The soft core component is butyl latex; The hard intermediate layer component is a combination of one or more of methyl methacrylate, methyl acrylate, ethyl acrylate, styrene or butyl methacrylate; The soft shell component is a combination of one or more of butyl acrylate, isooctyl acrylate, methacrylic acid, hexadecyl acrylate or octadecyl acrylate.

2. The water-resistant white polyacrylate emulsion protective film glue according to claim 1, characterized in that: The hard middle layer component is a composition of methyl methacrylate and butyl methacrylate; the mass ratio of methyl methacrylate to butyl methacrylate is 8.0-15.0:5.0-10.

0.

3. The water-resistant white polyacrylate emulsion protective film glue according to claim 1, characterized in that: The soft shell component is a composition of butyl acrylate, isooctyl acrylate, octadecyl acrylate and methacrylic acid; the mass ratio of butyl acrylate, isooctyl acrylate, octadecyl acrylate and methacrylic acid is 10.0-15.0: 5.0-10.0: 3.0-5.0: 1.0-2.

0.

4. The water-resistant white polyacrylate emulsion protective film glue according to claim 1, characterized in that: The butyl latex includes butadiene-isoprene latex, styrene-butadiene latex, nitrile-butadiene latex or carboxylated styrene-butadiene latex.

5. The water-resistant white polyacrylate emulsion protective film glue according to claim 1, characterized in that: The emulsifier is a combination of one or more of nonylphenol oxyethylene ether sulfate ammonium salt, alkyl alcohol alkoxylated sulfate sodium salt, nonylphenol ethoxylated sulfate ammonium salt, alkyl alcohol ethoxylated sulfate sodium salt, sodium dodecyl sulfate, and sodium vinyl sulfonate.

6. The water-resistant white polyacrylate emulsion protective film glue according to claim 1, characterized in that: The initiator is one of ammonium persulfate, potassium persulfate or sodium persulfate.

7. The water-resistant white polyacrylate emulsion protective film glue according to claim 1, characterized in that: The invention comprises the following raw material components in parts by weight: 8.0-15.0 parts of soft core component, 10.0-25.0 parts of hard middle layer component, 19.0-33.0 parts of soft shell component, 1.5-3.0 parts of emulsifier, 0.45-0.7 parts of initiator, and 30.0-55.0 parts of deionized water.

8. The method for preparing the water-resistant white polyacrylate emulsion protective film glue according to any one of claims 1 to 7, characterized in that: The preparation is carried out by pre-emulsification emulsion polymerization.

9. The method for preparing the water-resistant white polyacrylate emulsion protective film glue according to any one of claims 1 to 7, characterized in that: The following steps are involved: Mixing the hard intermediate layer component with part of the emulsifier, part of the initiator and part of water to obtain a hard intermediate layer pre-emulsion; The soft shell component is mixed with the remaining amount of the emulsifier, part of the initiator and part of water to react to obtain a soft shell pre-emulsion; The soft core component is mixed with the remaining initiator, the remaining water, the hard intermediate layer pre-emulsion and the soft shell pre-emulsion to react, so as to obtain the water-resistant white polyacrylate emulsion protective film glue.

10. Use of the water-resistant white polyacrylate emulsion protective film glue as claimed in any one of claims 1 to 7 as a surface protection material.

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