Acrylic Adhesives Research Articles

Adhesion at Poly(Butylacrylate)–Poly(Dimethylsiloxane) Interfaces

We present an investigation of the adhesion modulation mechanisms of silica-like nanoparticles (MQ resins) incorporated in polydimethylsiloxane (PDMS) elastomers and acrylic adhesives. The Johnson-Kendall-Roberts (JKR) test has been used to gain information on the both zero velocity and the velocity dependence of the adhesive strength, avoiding as much as possible contributions to the adhesive strength of bulk dissipation in the adhesive (which is not the case with peel tests). As the incorporation of the MQ resins into the elastomers deeply affects their own mechanical properties, the loading and unloading curves of small poly(butylacrylate) (PBA) lenses on either PDMS elastomers, adsorbed PDMS and pure MQ resin layers are compared in a systematic manner. The PBA chains are observed to have a neat affinity for the MQ resin nanoparticles. When MQ resins are present at the interface, they tend to prevent facture propagation, thus producing a larger deformation of the PBA lens. The modulation of adhesion is then dominated by the corresponding dissipation inside the acrylic adhesive.

Peristomal skin care: an overview of available products

Intact skin provides a protective barrier between the body and its environment. The frequent application and removal of stoma appliances can damage skin by stripping away the epidermal layer. Hydrocolloid flanges in either a one- or two-piece appliance hold moisture in the mass and are therefore more skin friendly than older appliances with acrylic adhesives, making hydrocolloid the choice for ostomy appliance manufacturers. Peristomal skin problems are a significant problem for the stoma patient. As many as one third of colostomy patients and more than two thirds of ileostomy and urostomy patients will be affected (Lyons and Smith, 2003). The correct and judicial use of barrier creams, gels, lotions, sprays and wipes in peristomal skin care can play an important role in giving the stoma patient a good quality of life.

Assessing the value of silicone and hydrocolloid products in stoma care

Intact skin among many other functions provides a protective barrier between the body and its environment, which is critical in regulating transepidermal water loss (Wilkinson and Moor, 1982). The frequent application and removal of adhesives can damage skin by stripping away the outer epidermal layers. Older people, very young children and those with an underlying skin disorder may be particularly at risk (Gibelli et al, 1999; Lyons and Smith, 2003). Hydrocolloid adhesives, which hold moisture in the adhesive mass, are more skin friendly than the acrylic adhesives they now replace and have now become the material of choice for ostomy flanges and flange extenders (Smith et al, 2007). To understand stoma care nurses' awareness of the value of technologically advanced silicone and hydrocolloid products, the authors undertook a nationwide postal survey. The survey, commissioned by four companies in the United Kingdom, who make silicone and hydrocolloid products that can be used in stoma care, were keen to evaluate the awareness of these products to confirm their importance to the patient and why they should be appropriately categorized for reimbursement by the Department of Health.

Viscoplastic Behavior of Acrylic Adhesive in Butt-Joint at Various Temperatures under Complex Loading : Experimentation and Modelling

The effects of temperature and strain rate on flow stress of a highly ductile acrylic adhesive were investigated by performing tensile lap shear experiments on an adhesively bonded single-lap joint, as well as torsion experiments on a tubular butt-joint at temperatures ranging from 10 to 40oC at various shear strain rates. The flow stress decreases considerably with decreasing strain rate and with temperature rise. The stress-strain responses under multi-axial stress conditions were also examined by performing combined tension-torsion experiments on the butt-joint. A constitutive model of temperature-dependent elasto-viscoplasticity that describes multi-axial stress-strain behavior of the adhesive is presented.

UV-crosslinked acrylic pressure-sensitive adhesive systems containing unsaturated ethers

A new class of acrylic pressure-sensitive adhesives (PSA), containing oxirane groups [formula (VII)], were developed. PSA systems obtained from butyl acrylate, glycidyl methacrylate and acrylic acid were modified with selected unsaturated allyl, vinyl or 1-propenyl ethers [formulas (I)-(VI)] in amounts of 1.0 to 5.0 wt. %. Then they were cured (using UV lamp) in the presence of 1.0 wt. % of cationic photoinitiator Irganocure 261 at room temperature and air atmosphere for 3 min. The tack, adhesion to glass and cohesion values of the cured PSA samples were measured. The effects of the type and concentration of unsaturated ether monomers used on these properties were evaluated. It was found that vinyl and 1-propenyl ethers were the most UV reactive crosslinking monomers while allyl ethers deteriorated PSA properties. The most advantageous values of adhesion, cohesion and tack were obtained for the samples containing 2 wt. % of vinyl or 1-propenyl ether. The results of investigations showed also that increase in crosslinking time, under UV radiation, caused faster increase in cohesion of the samples modified with vinyl ethers in comparison with those modified with 1-propenyl ones.

Development of solvent-free acrylic pressure-sensitive adhesives

The present publication describes a problem to develop solvent-free acrylic pressure-sensitive adhesives (PSA). Solvent-free PSA are established materials for the manufacturing of various self-adhesive products. Only by means of these acrylic PSA was it possible to succeed in drafting the present surprisingly efficient generation of double-sided pressure-sensitive adhesive tapes, medical products, protective masking films, films for the graphics market, and various specialty products. New applications and technical specifications stimulate the continuous development of new methods of polymerization of solvent-free acrylates. New syntheses of solvent-free acrylic PSA include polymerization in the reactor with removal of the solvent and polymerization on the carrier. The polymerization process is connected with UV-crosslinking.

Optimizing the Monomer Composition of Acrylic Water-Based Pressure-Sensitive Adhesives To Minimize Their Impact on Recycling Operations

Results are reported on a study of the variables controlling the impact that acrylic water-based pressure-sensitive adhesive (PSA) has on paper recycling operations. Surface, bulk, and performance properties of 25 commercial acrylic water-based PSAs were characterized and compared against their laboratory-measured screening removal efficiencies. No correlation was discernible. However, the results did indicate that the use of both vinyl acetate and acrylic acid monomers produced adhesives that readily fragment during repulping operations, resulting in little or no removal via screening. Study of a model system developed to further examine this phenomenon demonstrated that replacing these monomers with those possessing greater hydrophobicities, gauged here with their octanol−water distribution coefficients, produced a substantial increase in measured removal efficiencies. The improvements correlate with the wet tensile strengths of water-soaked adhesive films. The measured dependency of removal efficiencie...

Synthesis of photoreactive solvent-free acrylic pressure-sensitive adhesives in the recovered system

Synthesis of photoreactive solvent-free acrylic pressure-sensitive adhesives in the recovered system The present paper discloses a novel photoreactive solvent-free acrylic pressure-sensitive adhesive (PSA) systems, especially suitable for the so much adhesive film applications as the double-sided, single-sided or carrier-free technical tapes, self-adhesive labels, protective films, marking and sign films and wide range of medical products. The novel photoreactive solvent-free pressure-sensitive adhesives contain no volatile organic compounds (residue monomers or organic solvent) and comply with the environment and legislation. The synthesis of this new type of acrylic PSA is conducted in common practice by solvent polymerisation. After the organic solvent are removed, there remains a non-volatile, solvent-free highly viscous material, which can be processed on a hot-melt coating machine at the temperatures of about 100 to 140°C.

Viscoelastic properties and peel strength of water-borne acrylic PSAs for labels

The use of acrylic emulsion pressure-sensitive adhesives (PSAs) in labels continues to increase due to their environmental friendliness, good aging resistance and excellent processability during coating process. This study has investigated the acrylic emulsion/tackifier blend systems by examining their thermal properties as indicated by the glass transition temperature (T g), by conducting optical microscopy to determine their structure, by exploring their viscoelastic properties with the advanced rheometric expansion system (ARES), and by measuring their peel strength with the 180° peel test. The acrylic emulsion/tackifier blends with low softening point and low molecular weight exhibited only a single T g. However, the acrylic emulsion/tackifier blends with high softening point and high molecular weight showed two T g values. Microscopic observation of blends with miscible tackifier did not show any evidence of tackifier traces, whereas the microscopic structures of blends with immiscible tackifier showed dispersed tackifier particles. As the tackifier content increased, the rubbery plateau region decreased for the miscible blends but increased for the immiscible blends. The 180° peel strength of the miscible blends was dependent on the viscoelastic properties and was influenced by incorporation of tackifiers in the PSA systems. However, the peel strength of the immiscible systems did not depend on the viscoelastic properties at low tackifier content, but it decreased as the tackifier content increased in accordance with the increase of the storage modulus G′.

高度水添テルペンフェノール樹脂の電子材料用途への応用

This article presents about raw materials and characteristic of terpene resins, additionally introduces new type terpene resin.Terpene resins are synthesized from essential oil of pines and orange peels. These resins are used as tackifier of adhesives, such as pressure sensitive adhesives and hot melt adhesives. Also these resins are used for modifier of elastomers and plastics.The new type hydrogenated terpene resin has been developed for electoronic materials. This resin contains hydroxyl group and has weather resistance and light stability. Therefore it is used as a modifier of taransparent plastics and a tackfier of acrylic type adhesives including UV radiation curing adhesives.

The curing performance of UV-curable semi-interpenetrating polymer network structured acrylic pressure-sensitive adhesives

This article reports on the curing performance of UV-curable acrylic binders prepared with trifunctional monomers and a photoinitiator. The curing reaction was achieved by direct excitation of pressure-sensitive adhesives (PSAs) by irradiation with a 100-W high-pressure mercury lamp with different UV doses. The curing performance of PSAs was studied by photo-differential scanning calorimetry (photo-DSC), gel-fraction determination and Fourier transform infrared–attenuated total reflection (FTIR–ATR) spectroscopy. The reaction rate and extent of UV curing were found to be strongly dependent on the curing rates of the trifunctional monomers, trimethylolpropane triacrylate (TMPTA) and trimethylolpropane ethoxylated (6) triacrylate (TMPEOTA), which have different molecular weights. Exothermic areas increased with increasing acrylic acid concentration. Moreover, gel fractions sharply increased after UV irradiation and then remained constant with prolonged UV exposure. TMPTA blends had higher gel fractions than TMPEOTA blends because of TMPTA's fast curing rate. Also, the gel fractions of TMPTA blends showed no variation with acrylic acid concentration. However, the FTIR–ATR absorption peak areas representing the relative concentration of C=C bonds showed more conspicuous trends for the curing reaction. Although the gel fractions of TMPTA blends showed no differences, the relative concentrations of C=C bonds increased with increasing acrylic acid concentration. In addition, TMPTA blends showed higher relative concentrations of C=C bonds because of the faster curing rate of TMPTA.

Synthesis and cross-linking of acrylic PSA systems

Since their introduction half a century ago, pressure-sensitive acrylic adhesives have been successfully applied in many fields. They are used in self-adhesive tapes, labels and protective films, as well as in dermal dosage systems for pharmaceutical applications, in biomedical electrodes, and in the assembly of automotive parts, toys, electronic circuits and keyboards. Three properties which are useful in characterizing the nature of pressure-sensitive adhesives (PSAs) are tack, adhesion and cohesion. They are determined, to a large degree, by the kind of monomers, solvent nature, initiator type and amount, molecular weight of acrylic co-polymer, polymerization method, and especially by the type and quantity of the cross-linking agent added to the PSA. There are internal and external cross-linking agents. UV technology is well established in the market and allows the production of a wide range of UV-cross-linkable pressure-sensitive adhesives with interesting features.

524 アクリル系高延性接着剤を用いた単純重ね合わせ継手の疲労試験における接着層せん断ひずみ進展挙動のシミュレーション(GS.B 接着・接合)

524 アクリル系高延性接着剤を用いた単純重ね合わせ継手の疲労試験における接着層せん断ひずみ進展挙動のシミュレーション(GS.B 接着・接合)

The Role of Components in Waterbased Microsphere Acrylic Psa Adhesive Properties

AbstractIn this paper the batch suspension copolymerization of ethyl acrylate/2 ethyl hexylacrylate (EA/2‐EHA) for production of suspension‐based microsphere acrylic pressure sensitive adhesives (PSA) is presented. The effects on the adhesion properties of PSA different process (reaction temperature and stirrer speed) as well as chemical parameters (amount of EA, initiator concentration) are discussed. The conversion was monitored in‐line using Attenuated Total Reflectance‐Fourier Transform Infrared (ATR‐FTIR) spectroscopy and the results were compared with the standard gravimetrical method. The glass transition temperatures (Tg) of the PSAs were measured using differential scanning calorimetry (DSC) technique, while molecular weight distribution (MWD) was determined by gel permeation chromatography (GPC). The adhesion properties of PSAs were characterized via the measurements of tack, peel adhesion and peel strength. The results of the experiments have shown that the kinetics of the suspension polymerization for production of PSAs is significantly affected by temperature of polymerization and the initiator concentration, but are shown to be relatively independent of the EA amount and the stirrer speed. The tack, peel and shear strength depend on the mean particle size and particle size (PS) distribution (PSD) and Tg. The mean particle size and PSD depend primarily on the stirrer speed during the PSA synthesis process, while the Tg is most affected by amount of EA used for the synthesis. The results have also shown a rather unexpected relationship between MWD of the PSAs and the applicative properties: tack, peel and shear are seen to be increasing to the decreasing values of weight average MWD, which is the exact opposite of the previously published research. The most likely explanation for this relationship is the formation of a gel during the synthesis of PSA.

Influence of poly(ethylene glycol)‐α‐cyclodextrin complexes on stabilization and transdermal permeation of ascorbic acid

The present study was conducted to investigate the effect of poly(ethylene glycol)-alpha-cyclodextrin (alpha-CD) complexes on stabilization and cutaneous permeation of ascorbic acid from specially prepared transdermal patches. Poly(ethylene glycol) citrate (6-armPEG) and its inclusion complex with alpha-CD were prepared and used for preparation of the transdermal patches. Duro-Tak 87-2979 was taken as an adhesive matrix in combination with ascorbic acid. A diffusion cell with an artificial membrane was used to evaluate the absorption of ascorbic acid from the patches. The influence of drug release of alpha-CD and two types of its PEG complexes (as the novel permeation enhancers) was tested. The 6-armPEG-alpha-CD complex consisting of a PEG-citric acid ester at a concentration of 0.08-0.1% (w/v) is a suitable stabilizer for ascorbic acid during UV assay. The release studies showed that the type of enhancer is important in diffusion of the drug across membrane. Furthermore, the diffusion of ascorbic acid was considerably enhanced in the presence of 6-armPEG-alpha-CD complex. Inclusion complexes of 6-armPEG with alpha-CD at a concentration of 0.08-0.1% (w/v) is a suitable stabilizer for UV method of assay. The present data suggest that 6-armPEG-alpha-CD complex is also useful in enhancing the release of ascorbic acid from the acrylic type pressure sensitive adhesives.

New copolymerizable photoinitiators for radiation curing of acrylic PSA

This article presents a new class of copolymerizable photoinitiators containing vinyloxycarbonyl groups, known such as organic carbonate or carbamate. Novel copolymerizable photoinitiators have been prepared through the reaction between vinyl chloroformiate and hydroxyl groups containing photoreactive derivatives such as benzophenone-, acetophenone-, benzoine- and antraquinone-derivatives. The main emphasis is given to the influence of this new class of copolymerizable photoinitiators on photocrosslinking process of acrylic pressure-sensitive adhesives (PSA). Moreover, the paper describes the influence of various factors such as crosslinking time and concentration of copolymerizable photoinitiators on relevant PSA properties like tack, adhesion and cohesion.

The crosslinking reaction of acrylic PSA using chelate metal acetylacetonates

In this work, metal chelate zirconium acetylacetonate (ZrACA) was added into acrylic polymers with self-adhesive properties. These acrylic polymers, known as acrylic pressure-sensitive adhesives (PSA), were crosslinked with ZrACA to obtain acrylic self-adhesives with which to study the crosslinking reaction between carboxylic groups of the polymer chain and metal chelate crosslinking agent.

Skin Development during the Film Formation of Waterborne Acrylic Pressure-Sensitive Adhesives Containing Tackifying Resin

Tackifying resins (TR) are often used to improve the adhesive properties of waterborne pressure-sensitive adhesives (PSAs) derived from latex dispersions. There is a large gap in the understanding of how, and to what extent, the film formation mechanism of PSAs is altered by the addition of TR. Herein, magnetic resonance profiling experiments show that the addition of TR to an acrylic latex creates a coalesced surface layer or “skin” that traps water beneath it. Atomic force microscopy of the PSA surfaces supports this conclusion. In the absence of the TR, particles at the surface do not coalesce but are separated by a second phase composed of surfactant and other species with low molecular weight. The function of the TR is complex. According to dynamic mechanical analysis, the TR increases the glass transition temperature of the polymer and decreases its molecular mobility at high frequencies. On the other hand, the TR increases the molecular mobility at lower frequencies and thereby promotes the interdiffusion of latex particles to create a skin layer. In turn, the skin layer is a barrier that prevents the exudation of surfactant to the surface. The TR probably enhances the coalescence of the latex particles by increasing the compatibility between the acrylic copolymer and the solids in the serum phase.

New generation of crosslinking agents based on multifunctional methylaziridines

This publication describes new generation of crosslinking agents based on methylaziridine derivates, crosslinking reaction of pressure-sensitive acrylic adhesives (PSA) and their performance after crosslinking such as tack, adhesion and cohesion. Crosslinking of PSA is an established technology used in many industrial manufacturing processes. New applications and technical specifications stimulate the continuous development of new crosslinking agents with very interesting properties. The weak point of methylaziridine crosslinker systems, which is their very short pot life, is examined.

Preparation and adhesion performance of UV-crosslinkable acrylic pressure sensitive adhesives

UV-crosslinkable acrylic pressure sensitive adhesives (PSAs) were synthesized by copolymerization of 2-ethylhexyl acrylate (2-EHA), vinyl acetate (VAc), acrylic acid (AA), 2-hydroxyethyl methacrylate (2-HEMA) and 4-acryloyloxydiethoxy-4′-chlorobenzophenone (unsaturated photoinitiator), with varying contents of 2-HEMA and photoinitiator, by solution polymerization. The UV-crosslinking behavior of the PSAs was studied by ATR–FT-IR spectroscopy, and PSA performance was characterized by probe tack, peel resistance and shear adhesion failure temperature (SAFT). As 2-HEMA acts as a good hydrogen donor to benzophenone, the efficiency of the photo-reaction was enhanced; thus with increasing contents of 2-HEMA and photoinitiator in the PSAs the incorporation of benzophenone groups in the PSAs, even at low UV doses, was quite fast. In addition, as the crosslinking reaction proceeds via photo-reaction mainly between 2-HEMA and photoinitiator, the probe tack and peel resistance of the PSAs having high concentrations of 2-HEMA and photoinitiator rapidly decreased in the early stage of UV irradiation due to increased crosslink density. These phenomena were also observed in the SAFT test, with the PSAs containing high levels of 2-HEMA and photoinitiator showing high SAFT values at low UV doses.