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In a wide range of applications, general pressure-sensitive adhesive coating products are associated with increased odor problems associated with residual monomers in solvent-based acrylic pressure-sensitive adhesives. Therefore, there is a need to provide pressure-sensitive adhesive coating products that release less odor and reduce residual acrylic monomers. In addition, there is an urgent need to reduce residual C.

Various methods have been tried to reduce the above odor in the preparation of solvent-based acrylic pressure-sensitive adhesives. Examples include attempts to increase the conversion rate by increasing the amount of catalyst, attempts to extend the polymerization reaction time, attempts to add more initiators to the later stages of the polymerization reaction, And a method for adding initiators repeatedly during polymerization reactions

However, although these methods are effective in reducing monomer content, they either add more initiators later in the polymerization reaction or repeat initiators during the polymerization reaction, which sometimes results in significant changes in the properties of pressure-sensitive adhesives over time, especially in the properties of pressure-sensitive adhesives. It is observed that holding power sometimes varies greatly over time

In the Japanese Patent Publication No. Sho 63-175086, it was revealed that the method of adding a monomer scavenger after the polymerization reaction was basically completed to reduce the residual monomer. However, the response of the monomer scavenger is actually inadequate and as a residue is left and therefore cannot reduce the odor to a satisfactory degree. Although odor reduction has been studied, for medical adhesive materials using solvent-based acrylic pressure-sensitive adhesives, more consideration is given to preventing the resulting irritation, rash, cancerous itching, and erythematous lesions in the human body. There is a high requirement to minimize the concentration of residual monomers, so it is desirable to provide a medical pressure-sensitive adhesive in which the residual monomer content does not exceed 0.2 percent (by weight) of the total weight of the adhesive (based on solid content) before the introduction of the drug (Japanese Patent Disclosure No. Hei 5-131022).

For pressure-sensitive adhesive coating products and medical adhesive materials, it is urgent that the pressure-sensitive adhesive changes little over time, especially for medical adhesive materials applied to the human body, during the use of pressure-sensitive adhesive changes over time will have a serious impact on human comfort. For example, pressure-sensitive adhesion increases over time and can damage human skin when the medical adhesive material is removed. In addition, if the hardness of the pressure-sensitive adhesive layer increases over time, the stress placed on the human skin during application will increase the degree of irritation to the human skin.

Acrylic adhesives are known to be used, including heat melt adhesives, heat activation adhesives, and pressure sensitive adhesives to bond on a variety of substrates such as metals, painted surfaces, plastics, etc. Acrylic adhesives, especially acrylic pressure-sensitive adhesives are known for their transparency and excellent aging properties.

The preparation of acrylic pressure-sensitive adhesives has been reported in a number of literature, including, for example, US patents Re24,906(Ulrich), 4,181,752(Martens et al.), 4,952,650(Young et al.), and 4.569.960(Blake). Although acrylic adhesives are versatile, they do not bond well on some substrates, such as certain types of automotive paints and low-energy olefin surfaces commonly used in acrylic adhesives. Improving the adhesion of acrylic adhesives on these types of surfaces (i.e., increasing dry viscosity) has been investigated, usually by increasing the adhesion of base acrylic polymers. Various types of tackifying resins include phenol-modified alkenes, hydrocarbon resins (such as polyvinylcyclohexane and polytert-butylstyrene), and rosin resins (such as rosin glycerol vinegar and rosin pentaerythritol).

Due to the high solubility parameters of most acrylic pressure-sensitive adhesives and the particular potential interactions that exist between these adhesives and many viscosities resins, the options available to formulation designers for viscosifier resins are limited. As a class of resins, hydrocarbon base viscosifier resins, especially hydrogenated hydrocarbon resins, are not suitable for the preparation of polar acrylic binders because of their non-polar properties.

Among various acrylic pressure-sensitive binders, rosin base viscosifying resins and selected phenol-modified ene and A-delay resins show good performance. However, there are still some problems with the limited range of these viscosifying resins used in acrylic adhesives. Viscosifying acrylic pressure-sensitive adhesives preparations often turn discolored or yellow. The yellowing appearance of these viscosifying acrylic pressure-sensitive adhesives is a direct consequence of the particular yellow tint inherent in many of these viscosifying resins, which can become quite noticeable through aging and exposure to light even with lighter color grades. Acrylic adhesives without viscosities often have excellent aging properties.

Tape and adhesive sheets are made by forming an adhesive on the surface of the substrate. They are usually rolled into a roll and stored. In this case, the back surface of the substrate is usually coated with a release agent to protect the adhesive surface of the tape or adhesive sheet. It can be easily unwound when using tape or adhesive pieces. Alternatively, the adhesive surface is covered with a separate substrate coated with a release agent, thereby protecting the adhesive surface.

Various types of release agents are known. In particular, long-chain alkyl release agents (long-chain alkyl release agents) can be used in the electronics industry because they are less expensive and less likely to cause contamination.

An example of a long-chain alkyl release agent is published in the pamphlet International Bulletin W001/64805 and/or Publication (Japan’s unexamined Patent Bulletin)NO2001-240775. All kinds of long-chain alkyl release agent are acrylic release agent, which contains the product obtained before the acrylic release agent system with ultraviolet radiation, the precursor contains poly (methyl) acrylic cool, in 20C and 1Hz frequency of its energy storage elastic modulus of 1X102-3X10Pa, among which, the acrylic release agent has a contact Angle of 15° or greater against a mixture of methanol and water (volume ratio 90/1) with a wetting tension of 25.4N/m. After being applied to the substrate, the acrylic release agent to the substrate prepared by polyethylene terephthalate high adhesion. This acrylic release agent can keep the stripping force of pressure-sensitive adhesives such as acrylic pressure sensitive adhesives low even when placed at high temperatures. Moreover, this acrylic release agent basically has no effect on the adhesive residual adhesion.

It is obvious from the above instructions that the acrylic release agent is prepared by the steps of irradiating the acrylic release agent precursor with ultraviolet radiation. However, the UV dose required in this step varies greatly with the composition of the precursor of the acrylic release agent. When comparing compositions requiring a small dose to form a release agent with compositions requiring a large dose, the dosage sometimes varies by a factor of 3 to 5.

A pressure-sensitive adhesive is one that [0002] allows a durable connection to the substrate even at relatively weak external pressures and that can be re-separated from the substrate with little residue after use. Pressure-sensitive adhesives are permanently pressure-sensitive adhesives at room temperature, in other words having a low viscosity (viscosity) and high viscosity (tack) enough to mean that they can wet even the surface of the corresponding substrate at low external pressure. Adhesives derive their ability to bond from their adhesive properties, and their ability to reseparate from their cohesive properties. Different compounds are considered the basis of the pressure-sensitive adhesive. The main categories include natural rubber, synthetic rubber, and acrylates).

Pressure-sensitive adhesives based on natural rubber have been known for a long time. The natural rubber has very good cohesive properties. However, poor aging resistance and weather stability are a problem. CA 698 518 describes the operation of preparing compositions by adding high plasticizer content and/or simultaneously strongly plasticizing rubber. Although extremely viscous PSA can be obtained by this method, the relatively high plasticizer content or the severe degradation of the molecular structure of the elastomer to a mean molecular weight of M1 million means that there are limits to the achievability of user-compatible shear strength, even with relatively high subsequent crosslinking.

The use of polymer blends (in which not only non-thermoplastic natural rubber is used, but also segment copolymers with ratios of about 1:1) is essentially an unsatisfactory compromise solution that neither achieves high shear strength (when the self-adhesive tape is used at higher temperatures) nor significantly improves the properties described in this application. JP 07 324 182 A2 describes a multi-stage method in which double-sided tape has a pressure-sensitive adhesive layer based on an acrylic resin-like adhesive, and a second layer containing a blend of isoprene-styrene elastomers, natural rubber, and a non-reactive hydrocarbon resin (Arkon P 100). This tape serves as carpet-laying tape. It also has no demanding shear strength at high temperatures.

In the automotive industry, epoxy adhesives are used in many bonding applications, including metal-to-metal bonding of frames and other structures in automobiles. Some of these adhesives must be strong enough to withstand damage in the event of a vehicle crash. This type of adhesive is sometimes referred to as a “crash-resistant adhesive” or “CDA”.

Epoxy adhesives are often formulated with various rubbers and/or “tougheners” in order to obtain a good balance of properties required to meet stringent automotive performance requirements. These tougheners have closed functional groups that can become unsealed and react with epoxy resins under conditions of curing reaction. This type of toughening agent is described in US Patent 5,202,390, US Patent 5,278,257, WO 2005/118734, US Published Patent Application 2005/0070634, US Published Patent Application 2005/0209401, US Published Patent Application In 2006/0276601 and EP-A-0 308 664.

Commonly used toughening agents are terminated with phenol groups, polyurethane vinegar, and/or veins. These tougheners have been used with some success in [0005]CDA applications. However, in some cases, it is necessary to further improve the strength of these adhesives and to develop adhesives that break more often by cohesive rather than cohesive failure when curing. Another type of toughening agent is acrylate-terminated polyurethane and/or business. These have been described in WO03/078163 for single-component epoxy adhesives, and in US 5,232,996, US 6,660,805, and US Published Patent Application 2004/0229990 for two-component adhesives. Acrylic end tougheners generally perform worse than the phenolic end types used in CDA applications. Their use tends to result in poorer lap shear and impact stripping strength in cured adhesives. Adhesives containing acrylate-end tougheners also tend to break in an adhesive mode rather than a more suitable cohesive mode.