Flexible structural adhesives

Flexible structural adhesives are known to have unacceptably poor high-temperature performance and poor durability.

Structural adhesives are known for binding metal to metal, metal to plastic, and plastic to plastic. Structural adhesives are an attractive alternative to mechanical joint methods such as riveting and spot welding because they distribute load stresses over a large area rather than concentrating such stresses at a few points. Because fasteners do not need to be hidden to achieve an aesthetically pleasing appearance, the use of structural adhesives can reduce or eliminate retouching costs. Structural adhesives also result in cleaner and more stable products because they keep out water, dust, and noise. In addition, they can be used to bond a variety of different materials without the need for a large area of surface treatment.

acrylate copolymer adhesive

Despite their attractiveness, structural adhesives are known to have a number of potential disadvantages Although structural adhesives are known to have good high-temperature properties and good durability, the adhesive bodies they form are rigid. The rigid adhesive causes the stress to be unevenly distributed in the adhesive body, i.e. the stress at the edge of the adhesive body is higher than the stress in the middle of the adhesive body. For example, when gluing two workpieces together at overlapping parts, increasing the overlap size does not significantly improve bonding strength. In addition, because the adhesive will not break, but will knock off paints and coatings or in some cases break fiber-reinforced plastics, uneven stress on rigid structural adhesives can lead to workpiece damage.

In addition, structural adhesives that overcome rigidity problems are known. These elastic adhesives distribute stress evenly throughout the bonding body. The effect of this phenomenon is to absorb and disperse the load efficiently. However, flexible structural adhesives are known to have unacceptably poor high-temperature performance and poor durability.

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Acrylic pressure sensitive adhesive-double sided adhesive

Double-sided tape used to engage and fix parts can be widely used in vehicles and homes, especially in the interior of electronic machines. However, in recent years, several problems have been raised with the use of these adhesive tapes. For example, there are white fog caused by volatile components with high boiling points on the glass inside a car, and problems such as poor operation of electronic machines caused by volatile components or impurities with high boiling points. As a result, adhesive strips used in enclosed Spaces such as cars, houses, and electronic machines are required to have a low amount of volatile gases, which can negatively affect the environment, as well as low odor.

Odorless pressure sensitive adhesive

In response to this problem, in the housing sector in Japan, the Ministry of Health, Welfare, and Labor has issued guidelines to reduce the total amount of volatile organic compounds, while sticking to the previous principle of reducing the amount of volatile organic compounds in a single room as a countermeasure to the intensive housing. In addition, the German Automobile Industry Association (VDA) has adopted VDA270 as an evaluation method for odor of components used in cars, and VDA277 and VDA278 as volatile components. In addition, the German Industry Association establishes German Industry Standard No. 75201 in order to determine the signs of white fog produced by volatile components produced by components. This requires not only the reduction of specific volatile substances, but also the reduction of a wide variety of volatile substances in various fields.

As the cause of volatile gases produced by common adhesive strips, examples can be given as residual solvents, residual monomers, residual polymerization initiators, and viscosifiers used to improve adhesive properties. The same causes of odor can be cited as volatile gases.

In bulletin No. 6-122859, a method for obtaining a binder with few remaining monomers by polymerization of monomers with high molecular weight and low saturation vapor was disclosed. In addition, in the communique No. 2-115291 of Takaepyeong, a binder that uses acrylic polymers made from specific oleic acid monomers to reduce odor was announced. On the other hand, in Bulletin No. 2002-69411, the following method for the manufacture of adhesive strips is disclosed, that is, in order to reduce volatile components, solution polymerization is carried out by using a specific amount of azo polymerization initiator and setting a specific reaction temperature. A high purity acrylic polymer with few volatile components such as residual initiator and unreacted monomer is generated with a high polymerization rate, and then adhesive obtained from this adhesive is used to manufacture adhesive tape. In Bulletin No. 2002309210 of Special Kaiping, adhesive strips with low gas emission levels obtained by block copolymerization are disclosed. In addition, the manufacturing method of hot-melt adhesive tape as an anti-fog adhesive tape is disclosed in the communique No. 11-315260 of the Special Kaiping.

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Pressure sensitive adhesive contains a radiation-sensitive acrylic polymer

Pressure-sensitive adhesives (often referred to simply as “PSA”) and the method of polymerizing compositions to prepare pressure-sensitive adhesives are known from the prior art. For example, Us Patent No.4,181,752(Martens et al.) discloses a one-step US patent for the preparation of a standard viscous pressure-sensitive adhesive by irradiating a polymerizable substance containing a radiation-sensitive acrylate at an integrated flux rate of approximately 0.1-7 mW/cm ‘in the near-UV region No.6,174,931B1(Moon et al.) discloses a multistage radiation method for the preparation of acrylic series compositions such as adhesives or pressure-sensitive tapes.

Water-based adhesive

The first phase of radiation is electromagnetic radiation at a lower integral flux rate (i.e. 0.1-20 mW/cm ‘) to allow the monomer to undergo a lower degree of conversion, and in the next phase, electromagnetic radiation at a higher integral flux rate (i.e., greater than 20 mW/cm2) to allow the monomer to undergo basically complete photopolymerization. Us Patent No.6.040,352 discloses a method for preparing an adhesive composition that consists of irradiating a free radical polymerizable composition under a monochromic radiation source with spectral output peaks in the wavelength region of approximately 250 to 600mm.

Uv radiation with low integrated flux rates (e.g., about 0.1-20 mW/cm) can be used to form high molecular weight acrylate polymers, which are particularly useful as pressure-sensitive adhesives with high-performance properties (e.g., high static shear strength). However, even after a long time of radiation, a small amount of unpolymerized material remains in general polymerized materials, which are not suitable for some applications. Therefore, there is still a need to improve the method of polymerization of compositions to prepare pressure-sensitive adhesives.

We need to provide a method that can achieve a higher degree of polymerization (i.e., a higher degree of transformation) in significantly less time without sacrificing physical properties than previously known techniques using a single light source or combination of light sources. Surprisingly, it has been found that, in practice with the present invention, the second light source preferably has emission wavelengths mostly in the region of about 200-280nm, although there is evidence that such light sources alone do not produce high-performance pressure-sensitive adhesives.

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Acrylic resin composition in acrylic pressure sensitive adhesive

Polycarbonate resins are characterized by impact resistance, transparency, lightness, and workability, and have been used in many applications. In particular, due to its transparency, polycarbonate resins have been used to replace the glass. However, polycarbonate resins are not sufficiently weatherproof, and their physical properties and appearance will be damaged due to decomposition and aging during long-term outdoor use. This is known to all. In addition, polycarbonate resin also has a lack of wear resistance, and surface damage and is easy to be etched by solvents and other shortcomings.

acrylic pressure sensitive adhesive

In recent years, due to the lightweight and safety of polycarbonate, there has been a trend for suitable plexiglass window glass, especially automobile window glass. Polycarbonate sheets used in such applications are required to have the same high weather resistance as glass

Also, as the front glass, it is necessary to prevent chafing when the wiper is working, and the side window glass is required to prevent chafing when the window is raised and lowered, which requires it to have a high level of friction resistance.

Furthermore, it can be assumed that the temperature of the roof of the automobile will become very high in the hot summer and therefore the polycarbonate forming material used as the roof glass will be required to have strong durability against environmental changes and high temperatures.

In order to improve these shortcomings, a variety of schemes have been proposed in the past about the preparation of thermosetting acrylic resin layer on the surface of polycarbonate substrate and then coating it with siloxane curing film to obtain the laminate with improved weather resistance, durability, and friction resistance.

On the other hand, for the purpose of improving wear resistance, a coating composition consisting of a partial condensation of twilight silane and colloidal silica has been proposed. In addition, a scheme has been proposed for the composition of paints using a partial condensation of alkyl tri alkoxy silane and tetra alkoxy silane as the main component. Furthermore, a scheme of adding colloidal silica composition for the coating to the condensation of alkyl tri alkoxy silane and tetra alkoxy silane has been proposed.

Although the composite of the cured coating obtained from the composition of these coatings on a polycarbonate substrate has to some extent excellent abrasion resistance, its durability under environmental changes and high temperatures is not sufficient.

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Background of the invention of acrylic pressure sensitive adhesive

For example, for vehicles such as cars, trains, buses, etc.; Household appliances such as televisions, personal computers, air conditioners, and so on; Office appliances such as fax, photocopier, etc. In airplanes; Boats and ships; houses; Pressure-sensitive adhesives and pressure-sensitive tapes in various fields such as factories, polyvinyl chloride (hereinafter referred to as PVC) are widely used as adhesives or substrates. But the incineration of polyvinyl chloride produces toxic gases such as dioxins and chlorine.

In view of the increased environmental awareness in recent years, restrictions on the use of PVC and a shift to materials that reduce the environmental burden have been initiated. Therefore, there is a strong demand for alternatives to PVC. Similarly, alternatives to the following substances are also needed: pressure-sensitive adhesives containing halogen atoms, and pressure-sensitive tapes containing halogen atoms as substrates as alternatives to halogen atoms containing materials such as PVC. Olefin polymers such as polyethylene, polypropylene, etc., are increasingly being used because of their cost and elasticity. The adhesive body may consider using pressure-sensitive tape with this material as the base material, and pressure-sensitive adhesive and pressure-sensitive tape products use these materials.

When such olefin polymers are used as substrates or adhesives for tape, rubber, and acrylic pressure-sensitive adhesives are used for cost reasons.

However, when rubber pressure-sensitive adhesives are used, the bonding strength for substrates or adhesives made from alene polymers becomes too strong, which can cause problems for pressure-sensitive tapes, such as difficulty unwinding the tape, etc. During unwinding, straps often suffer from substrate stretching, substrate breaking, and so on. When rubber pressure-sensitive adhesives are used in adhesives made from olefin polymers, the cause of the problem is the excessive bonding strength, which can be demonstrated by the residue (i.e., the residue of the adhesive) attached to the adhesive at the time of spallation, etc.

When acrylic pressure-sensitive adhesives are selected, problems such as weak bond strength for substrate surfaces or poor polar adhesives such as olefin polymers can arise

For example, in the case of adhesive tape, the unwinding force and fastening force of the tape are weak, which does not complete enough winding. In addition, because of the weak adhesion to the substrate, the end of the tape will be defective after winding, and so on

By cross-linking the adhesive to increase cohesion strength and so on, you can prevent the end from peeling off, but at the same time, the bond strength is reduced and the unwinding force becomes weaker

As compensation, consideration has been given to adding viscosifiers to acrylic pressure-sensitive adhesives (e.g., resin viscosities, serene viscosifiers, petroleum aliphatic hydrocarbons (C; Viscosifier, petroleum aromatic (C) viscosities, and its hydrogenated compounds, etc.), trying to increase the bonding strength of the adhesive.

Changsheng is also a company dedicated to the research and development, production and sales of emulsion pressure-sensitive adhesives. We can effectively solve the problems that customers encounter in the use of glue because of different production equipment and technology.

We specialize in the production of the protective film and pressure-sensitive adhesives for many years, with our own R&D team. In the future, through continuous research and development and summing up experience, our glue can be applied to more product application fields.

Chemical flame retardants

Our acrylic pressure-sensitive adhesive is widely used in:

  • Fit of different film materials

Hot item: Glue FR-201

Advantages: Our laminating adhesive has strong peeling strength, suitable for laminating BOPP, CPP, PET, PE or other lightweight packaging film materials.

  • Protective film for household appliances

Hot stuff: Glue FR-07; Glue FR-102-2

Advantages: The series of adhesive peeling force increase small, does not leave residue, good anti-scalding performance.

The FR-07 is suitable for smooth surfaces of stainless steel, and the FR-102-2 is suitable for slightly rough surfaces.

  • outdoor protective film

Hot stuff: Glue FR-04; Glue FR-W78-1; Glue FR-091-6

Advantages: This series of glue has the advantages of temperature resistance (including high and low temperature), moisture-proof, and waterproof performance. Their adhesive force is different and can meet different bonding requirements.

Glue FR-091-6 is especially suitable for carpets, fluorocarbon spray aluminum profiles, and other rough surface.

  • Off-line Low-E glass protective film

Hot item: FR-08-J7

Strength: It has the characteristics of strong stripping strength and moderate unwinding performance.

Wuxi Changsheng Adhesive Products Co., Ltd. is also committed to emulsion pressure-sensitive adhesive research and development, production, and sales of the company. We can effectively solve the problems that customers encounter in the use of glue because of different production equipment and technology.

We specialize in the production of the protective film and pressure-sensitive adhesives for many years, with our own R&D team. In the future, through continuous research and development and summing up experience, our glue can be applied to more product application fields.

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Acrylic pressure sensitive adhesive has excellent pressure sensitive bonding properties

The acrylic pressure-sensitive adhesive has excellent pressure-sensitive bonding properties, such as adhesion, cohesion and weather resistance, and oil resistance. Therefore, this adhesive is widely used as a pressure-sensitive adhesive (adhesive) in pressure-sensitive adhesive layers that form pressure-sensitive adhesive tapes, labels, or sheets.

acrylic pressure sensitive adhesive

The previously used acrylic pressure-sensitive adhesive is a copolymer that uses one or more alkyl (methyl) acrylates as its main component to form a viscous polymer with a lower glass transition point, such as n-butyl acrylate or 2-ethyl hexyl acrylate, with a monomer having a functional group, For example, acrylic acid, 2-light ethyl (methyl) acrylate or acrylamide, as a crosslinking point in the viscous polymer, or improve the intermolecular force, improve the cohesion of the ingredients; And a copolymer formed by copolymerization with monomers such as styrene, vinyl ester as a monomer component of a hard monomer that can form a hard polymer with a higher glass transition point. This type of polymer used as a pressure-sensitive adhesive of acrylic acid is generally manufactured by solution polymerization, suspension polymerization, or emulsion polymerization.

Solution polymerization, however, not only needs to overcome environmental health concerns due to the large number of organic solvents used but also requires energy to separate the polymer and the steps required to distill the organic solvent: resulting in increased costs. The disadvantage of suspension polymerization and emulsion polymerization is that the emulsifier or dispersant used in polymerization enters the polymer, so it is difficult to obtain a pure polymer. In addition, the cost of suspension polymerization and emulsion polymerization is similar to solution polymerization because water is evaporated to separate the polymer.

In addition, because the above method of polymerization to prepare acrylic acid pressure-sensitive adhesive is generally used in batches, under polymerization conditions such as temperature and monomer concentration so the uniformity of the polymerization system is poor. Thus, the increased conversion to polymer leads to a widening of the molecular weight distribution and a decrease in monomer concentration in the final stage of the reaction, resulting in the formation of a large number of low molecular weight products. As a result, the resulting polymer has weakened pressure-sensitive adhesive properties. When such polymers are used as pressure-sensitive adhesives, there is a problem with increasing the component of the group converted to the adhesive.

About Changsheng pressure-sensitive adhesive supplier

As a professional acrylic pressure-sensitive adhesive supplier, Changsheng is committed to solving the problems encountered by customers in the use of glue due to different production equipment and processes.

Compared with traditional solvent-based pressure-sensitive adhesive, our emulsion pressure-sensitive adhesive has the advantages of environmental protection, safety, and easy operation. Using deionized water instead of traditional solvent reduces pollution to the environment and is an ideal environmental protection product.

By adjusting the proportion of the curing agents, pressure-sensitive adhesives with different adhesive forces can be obtained to meet the needs of different applications. Suitable for a variety of materials, transparent after drying.

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Polyacrylate in pressure sensitive adhesive can be composed of a wide range of monomers in a variety of ways

Polyacrylate can be composed of a large selection of monomers in a variety of ways. In this way, the pressure-sensitive adhesives of the polymers and their affinity to the surfaces to be bonded, such as human skin, can be adjusted within a wide range of limits.

In this respect, the chemical nature of the side chain on the cool stem of polyacrylic acid plays a key role. The side chain not only determines the hydrophilic-lipophilic balance in the polymer, for example, the amount of moisture that can be absorbed; In particular, the use of appropriate side chains and their mixtures can be used to reduce the crystallinity of polymers. The decrease in crystallinity and solidification of the glass transition temperature has a positive effect on the pressure-sensitive adhesion properties of the polymer, which promotes fluidity and the resulting rapid surface wetting.

Low-E glass protective film usage-1

The low glass transition temperature is of particular importance for the medical applications of TTSs: in the amorphous state, the polymer, i.e., its side chain pharmaceutical active substance and containing an adjuvant, is particularly permeable. This is necessary for rapid release at the site of the application.

Polyacrylates are highly soluble for most pharmaceutical active substances. In general, the solubility is higher than in other pressure-sensitive adhesives suitable for the manufacture of TTSs, such as in natural rubber-resin mixtures, or in pressure-sensitive siloxane adhesives.

Often, the required amount of the active substance is in fact only soluble in – and therefore mixed into – the TTS in a form most suitable for delivery. – Polyacrylate is used within the polyacrylate to polymerize acetate acrylic acid – or methacrylic acid into polyacrylic acid, the latter of which may have a free antelope group on its chain. The basis is suitable for later connecting several polymer chains to each other through the basis. Typical agents known to skilled persons in the field are organometallic complexes such as ethyl acetone aluminum or ethyl acetone complex. It can introduce polyvalent cations into the polymer, which can simultaneously bind to several antelope groups on different polymer chains.

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Activator composition in pressure sensitive adhesive

Adhesive compositions based on cyanoacrylate vinegar are well known and have a wide range of uses due to their rapid curing rate, excellent long-term bonding strength, and application to a wide variety of substrates. Generally, they harden after only a few seconds, after which the attached parts exhibit at least some initial strength.

It is well known that some cyanoacrylate vinegar (CA) binders are generally hardened by anionic polymerization. If the adhesive is routinely coated with a relatively thick layer or a relatively large amount of adhesive so that relatively large drops of adhesive protruded between the connecting parts, rapid hardening of the entire adhesive is almost impossible, that is, the curing of the entire gap or the curing of the whole volume (CTV) is not satisfactory.

factory

For some substrates, especially those with acidic surfaces such as wood or paper, polymerization may be delayed, often to an uncontrollable extent. In addition, unless the adhesive has been gelated or given thixotropy with appropriate additives, the wood or paper matrix, due to its pores, is prone to draw the adhesive out of the joint crevices by capillary action before the adhesive hardens in the crevices.

Therefore, there have been attempts to use certain additives to accelerate the polymerization of such CA adhesives. However, the storage stability of such formulations is generally compromised by the use of alkaline or nucleophilic substances that would normally significantly accelerate the polymerization of cyanoacrylate vinegar adhesives. Therefore, the direct addition of accelerators to adhesive formulations allows only very limited amounts. This accelerator is added a short time before the adhesive is coated, resulting in a de facto two-component system.

However, the disadvantage of this method is that its service life is limited after the activator is mixed. In addition, due to the small activation dose required, it is difficult to achieve the required accurate measurement and uniform mixing. Moreover, using this two-component system is cumbersome for the user, and sometimes only slightly improves the desired results

The activator may also be used in the form of a dilute solution that is pre-coated on the substrate or part to be bonded and/or coated on the adhesive after the substrate has been attached while the adhesive on it is still liquid. The solvent used for diluting solutions of this activator is generally a low-boiling organic solvent, which tends to evaporate, leaving the activator on the substrate/component or adhesive.

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Vinyl ester copolymer in pressure sensitive adhesive

Vinyl ester copolymer, a vinyl-acrylic copolymer, a vinyl-acrylic copolymer, an atactic polypropylene, or a polyethylene terephthalate linear polymer. The viscosifier is a hydrogenated rosin-type rosin or ester, whose double bonds are completely or partially removed by hydrogenation, or a single – or double-mushroom – phenol copolymer. Us Patent No.4,585,819(Reischle et al.) discloses a molten adhesive consisting of a 20 — 90% by weight isocyanate prepolymer and a 5 — 50% by weight low molecular weight synthetic resin, selected from a ketone resin, Us Patent No.4,775,719(Markevka et al., ‘719) for hydrogenated products and condensation resins of acetophenone discloses a hot-melt thermosetting polyurethane adhesive composition that can be extruded as a hot-melt adhesive to form a hot-melt adhesive with high initial wet strength.

pressure sensitive adhesive

And can be wet-cured into a hard wet-cured polyurethane adhesive. The polyurethane adhesive composition comprises (a) a film-forming thermoplastic vinyl-vinyl monomer copolymer, which is a vinyl monomer of an acrylate monomer or a vinyl ester of a gazelle compound; (b) a liquid polyurethane prepolymer composition; (c) A phenol-free, aromatic or aliphatic-aromatic polymer tackifier consisting of a monomer selected from C+-6 diene, styrene monomer, vaccine monomer, and cyclodiene: and (d) an antioxidant.

Vinyl ester copolymer, a vinyl-acrylic copolymer, a vinyl-acrylic copolymer, an atactic polypropylene, or a polyethylene terephthalate linear polymer. The viscosifier is a hydrogenated rosin-type rosin or ester, whose double bonds are completely or partially removed by hydrogenation, or a single – or double-mushroom – phenol copolymer. Us Patent No.4,585,819(Reischle et al.) discloses a molten adhesive consisting of a 20 — 90% by weight isocyanate prepolymer and a 5 — 50% by weight low molecular weight synthetic resin, selected from a ketone resin, Us Patent No.4,775,719(Markevka et al., ‘719) for hydrogenated products and condensation resins of acetophenone discloses a hot-melt thermosetting polyurethane adhesive composition that can be extruded as a hot-melt adhesive to form a hot-melt adhesive with high initial wet strength.

And can be wet-cured into a hard wet-cured polyurethane adhesive. The polyurethane adhesive composition comprises (a) a film-forming thermoplastic vinyl-vinyl monomer copolymer, which is a vinyl monomer of an acrylate monomer or a vinyl ester of a gazelle compound; (b) a liquid polyurethane prepolymer composition; (c) A phenol-free, aromatic or aliphatic-aromatic polymer tackifier consisting of a monomer selected from C+-6 diene, styrene monomer, vaccine monomer, and cyclodiene: and (d) an antioxidant.

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Acrylic pressure sensitive adhesive acrylic monomer has excellent cohesibility

Acrylic monomers have excellent cohesiveness and can be polymerized by a variety of reaction systems, including solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization technology.

For example, the following method has been proposed for the preparation of acrylic polymers. One method involves bulk polymerization by heating a mixture of acrylic monomers and mercaptans in the presence of oxygen at 20-200C (see Japan Patent Bulletin No.50(1975)-401). Another method involves polymerizing a mixture of acrylic monomers and mercaptans in nitrogen gas with essentially no initiator (see Japanese patent No258,251).

UV-curable pressure-sensitive adhesive

Another method involves using an extruded barrel device instead of a batch reactor for polymerization at high temperatures (near 150C) (see Japan Patent Bulletin No.2(1990)-55448). Another method involves irradiating the batch reactor with ultraviolet light through optical fibers and using ultraviolet pulse irradiation for polymerization (see Japan Patent Bulletin No.71995)-330815). Another method involves gradually changing the reaction temperature while irradiating the batch reactor with ultraviolet light. UV bulk polymerization is thus performed (see Japan Patent Bulletin No.11(1999)-49811).

However, when a conventional industrial batch reactor is used to react acrylic monomers in the presence of a thermal-decomposing polymerization initiator, the heat generation in the reactor is too strong for the reaction heat to be removed from the reaction system due to the high reactivity of the acrylic monomers. Therefore, it is not feasible to conduct bulk polymerization of acrylic monomers and control the reaction effectively in the presence of a thermal decomposition polymerization initiator in the reactor.

One disadvantage of using the barrel system is that the reaction requires setting the reaction temperature in the high-temperature region. As a result, the molecular weight distribution of the resulting polymer becomes wider and the molecular weight becomes more dispersed as the temperature control accuracy decreases.

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