TWI675897B - Damping type polyfluorene pressure sensitive adhesive and manufacturing method thereof - Google Patents

Abstract

The present invention provides an easily usable adhesive with good vibration damping properties, which can be used in a wide temperature range. This is accomplished by a composition for manufacturing a pressure-sensitive adhesive, the composition system comprising: a) at least one alkane group having at least two alkenyl groups bonded to Si and having a plurality of bonds to Si; Organic silicone polysiloxane; b) at least one organic silicone polysiloxane having at least two radically crosslinkable substituents having multiple aryl groups bonded to Si; and c) at least one Free radical initiator.

The subject of the present invention also has a pressure-sensitive adhesive, which is obtained by thermally crosslinking the composition according to the present invention.

Description

Vibration-damping polysiloxane pressure-sensitive adhesive and manufacturing method thereof

The present invention relates to the technical field of pressure-sensitive adhesives, which are widely used in the art for temporary or permanent bonding of materials and bonding members. The invention particularly relates to a polysiloxane pressure-sensitive adhesive, which is characterized by good vibration damping properties.

Damping is generally understood as the conversion of mechanical energy into so-called heat losses. In the case of acoustic vibration reduction, it irreversibly converts acoustic energy into heat. Acoustic damping (or synonymous with sound insulation and sound absorption) can occur in gases, liquids, and solids.

Sound generation to play dialogues, ringtones, music, etc. in mobile phones and smartphones is performed by small electro-acoustic converters (so-called miniature speakers). The size of such diaphragms (which are also used in headphones, notebook computers, LCD TVs, or personal digital assistants (PDAs)) typically ranges from 20 mm ² to 900 mm ² .

As the miniature speakers become smaller and thinner based on the design requirements of the corresponding electronic devices, in this case, they should also operate at higher power, which makes the miniature speakers and especially their diaphragms The temperature load is getting higher and higher. Therefore, the diaphragm must be made of a material that has a good life under high temperature and high mechanical load and will not tear. But at the same time, the diaphragm material should also have good acoustic properties to provide good sound quality for speakers.

The general requirements for speaker diaphragm materials are high rigidity and low density on the one hand to generate high sound pressure and cover a wide frequency range. On the other hand, the material should also have high internal damping to ensure a smooth frequency response and minimize distortion. Due to structural conflicts between rigidity, lightness and good vibration damping, which cannot all be satisfied at the same time (the more rigid the vibration damping is worse, and vice versa), each diaphragm must usually be made on the rigidity and vibration damping of the diaphragm material Compromise or combine rigid materials with materials with good vibration damping.

US 7,726,441 B2 describes a diaphragm formed of a multilayer composite composed of two rigid polymer films and a layer of vibration-damping adhesive between these films.

The patent specifications DE 10 2007 030 665 A1 and US 8,141,676 B2 both describe a five-layer composite in which two outer layers and an intermediate layer are separated from each other by a thermoplastic adhesive or an acrylic adhesive. In this multilayer diaphragm, the same adhesive with the same thickness is used for both adhesive layers. This is because the diaphragm in the speaker should vibrate as symmetrically and uniformly as possible, and the asymmetric structure with respect to the damping adhesive layer will easily cause deformation; the resulting sound quality will be reduced. Furthermore, the acoustic properties of the loudspeaker strongly depend on which side of the diaphragm with the asymmetric structure used is mounted on the coil. Therefore, symmetrical diaphragms are commonly used on speakers to avoid quality deviations due to incorrect installation of the diaphragm.

It can generally be said that the adhesive is used as a vibration damping material in the current technology, for example, in the combination of the rigid material and the material with good vibration damping mentioned above.

US 5,464,659 describes a method for suppressing the vibration of an object, which proposes to apply an anti-vibration material composed of 5 to 95% of an acrylic monomer and 95 to 5% of a polysiloxane adhesive to the object, the sum of two components of which Is 100%.

The use of an adhesive (especially a silicone adhesive) as a vibration damping component is not limited to a speaker diaphragm. For example, US 2014/0017491 A1 describes a polysiloxane adhesive, which contains a polysiloxane elastomer, a silicone resin, a reaction product formed by a polysiloxane elastomer and a silicone resin, and a polysilicon before curing. An oxygen-hydride cross-linking agent and a platinum catalyst. The resulting adhesive is used in transfer tapes used in the engagement of brake components, such as the engagement of brake discs and brake pads.

EP 1 018 725 A2 describes a method for noise reduction of a plate (such as a car body part), which is performed by bolting, riveting or riveting a metal plate to a plate to be denoised with an adhesive layer interposed. welding. Among them, the polyacrylate copolymer is used as the adhesive layer used with the board in a temperature range between -20 ° C and + 50 ° C, and for applications at higher temperatures in the range of 0 ° C to 100 ° C It is a crosslinked polysiloxane adhesive. By bolting, riveting, or welding, the energy of the vibrating plate is highly conducted in a sandwich structure composed of at least one adhesive layer and at least one metal plate, so the sandwich structure can convert most of the vibration energy For the heat.

EP 1 035 345 A2 describes a damping plate for mounting on a bearing plate of a brake shoe of a disc brake, which has a self-adhesive damping layer on the inside facing the brake shoe.

There is a continuing need for versatile adhesives with good vibration damping properties. The object of the present invention is to provide an easily usable adhesive with good vibration damping properties, which can be used in a wide temperature range.

The solution to this problem is based on the idea of using a blend of polysiloxane pressure-sensitive adhesive with some atypical crosslinking chemistry. The first and universal guest system of the present invention is a composition for manufacturing a pressure-sensitive adhesive, which comprises: a) at least one alkenyl group including at least two bonds to Si and a plurality of bonds to Si An organic polysiloxane of an alkyl group; b) at least one organic polysiloxane containing at least two radically crosslinkable substituents having multiple aryl groups bonded to Si; and c) At least one free radical initiator.

A pressure-sensitive adhesive, as commonly used in spoken language, is understood as a substance according to the present invention, which (particularly at room temperature) has permanent adhesion and has the ability to adhere. A pressure-sensitive adhesive is characterized by being able to be applied to a substrate by pressure and remains adhered thereto, wherein the duration of the pressure consumed and the effect of this pressure is usually not further defined. In some cases, depending on the exact type of pressure-sensitive adhesive, temperature and humidity, and the substrate, the effect of the short-term, minimal pressure effect (which does not exceed a brief slight contact) is sufficient to achieve the adhesion effect. In other cases longer-term sustained effects of high pressure may also be required.

Pressure-sensitive adhesives have special characteristics of viscoelastic properties, which lead to permanent tackiness and adhesion ability. It is characterized in that when it is mechanically deformed, it will produce a viscous flow process and form an elastic restoring force. In terms of their respective ratios, the two processes are within a specific ratio relative to each other, depending on the exact composition, structure, and degree of crosslinking of the pressure-sensitive adhesive, as well as the speed and duration of deformation and temperature.

Partial viscous flow is necessary to obtain adhesion. The sticky part (producing a macromolecule with a relatively high mobility) can have good wetting properties and good spreadability to the adhesive substrate. A high proportion of viscous flow leads to high pressure-sensitive adhesion (also known as initial adhesion or surface adhesion) and, as a result, often high adhesion. Highly crosslinked systems, crystalline polymers or glass-like cured polymers lack a flowable part and are usually not pressure sensitive or at least only slightly pressure sensitive.

Part of the elastic restoring force is necessary to obtain cohesion. It forms, for example, extremely long chains and highly entangled macromolecules that are physically or chemically crosslinked, and allows the forces acting on the bond to be transferred. It results in the bond being able to withstand a sustained load (e.g. in the form of a permanent shear load) acting on it to a sufficient extent for a longer period of time.

In order to more accurately describe and quantify the size of the elastic and viscous parts and the proportion of these parts relative to each other, the storage modulus (G ') and loss modulus (G "that can be determined by dynamic mechanical analysis (DMA) can be used ). G 'is the measure of the elastic part, and G "is the measure of the sticky part of the substance. Both depend on the deformation frequency and temperature.

This size can be determined by means of a rheometer. The material under test is subjected to a shear stress of sinusoidal oscillations, for example in a plate / plate configuration. In a shear stress controlled device, the deformation is measured as a function of time and the offset of the deformation to the input shear stress over time. This time shift is called the phase angle δ.

The storage modulus G 'is defined as follows: G' = (τ / γ) ‧cos (δ) (τ = shear stress, γ = deformation, δ = phase angle = phase shift between the shear stress vector and the deformation vector ). The loss modulus G "is defined as: G" = (τ / γ) ‧sin (δ) (τ = shear stress, γ = deformation, δ = phase angle = phase shift between the shear stress vector and the deformation vector ).

When at 10 ^° to 10 ¹ rad / modification within the frequency range G sec at room temperature (as herein defined in accordance with 23 ℃) 'at least partially in the range of 10 ³ to 10 ⁷ Pa, and when G "is also at least partially Within this range, the substance is generally considered pressure-sensitive adhesive and is defined as pressure-sensitive adhesive in the present invention. "Part" means that at least one paragraph of the G 'curve is within a window, the window It is generated from a deformation frequency range (abscissa) from 10 ⁰ to 10 ¹ rad / sec and a G 'value range (ordinate) from 10 ³ to 10 ⁷ Pa. This applies correspondingly to G ".

Pressure sensitive adhesives can be manufactured (substantially by removing solvents and crosslinked compositions) from the composition according to the invention, which have excellent (especially acoustic) damping properties across a wide temperature range that can be specifically adjusted. The composition according to the present invention or the pressure-sensitive adhesive made from it can be preferably used in any place where the damping effect must be exerted even at high temperature and / or variable temperature. It is particularly suitable for the bonding of thin films for speaker diaphragms and the bonding of components of brake systems.

The composition according to the invention comprises at least one organopolysiloxane as component a), which is also commonly referred to as polysiloxane. Preferably, the organopolysiloxane according to the present invention a) is a polymer having a composition in an organosiloxane unit such as the general formula (1)

(1) (R ₃ SiO _1/2 ) _n (R ₂ SiO) _m (RSiO _3/2 ) _o (SiO ₂ ) _p ,

0，其中該聚合物包含至少兩個鍵結於Si上的烷基與至少兩個烯基。式(1)不是結構式，所以僅為由有機基矽氧烷單元形成的有機基聚矽氧烷之組成物，而非其彼此重複連結。 Wherein the residues R each independently represent an alkyl residue, an aryl residue, a polydiorganosiloxy residue, or an alkenyl residue, and based on the number of all residues R, 0 to 10% represents an OH group And n, m> 0 and o, p

0, wherein the polymer comprises at least two alkyl groups and at least two alkenyl groups bonded to Si. Formula (1) is not a structural formula, so it is only a composition of an organopolysiloxane formed from an organosiloxane unit, rather than being repeatedly connected to each other.

Preferably, the organopolysiloxane a) is a linear polymer such as the general formula (2)

(2) R ' ₃ Si-O- (R' ₂ Si-O) _m -SiR ' ₃ ,

Where the residues R 'each independently represent an alkyl residue, a phenyl residue or an alkenyl residue, and based on the number of all residues R', 0 to 10% represent OH groups, of which at least two residues R ' Represents an alkyl group, and at least two residues R 'represent an alkenyl group; wherein m represents a natural number of 2,000 to 6,000. Basically the residue R ' is able to pass through linear polysiloxane branches in all conceivable and chemically feasible configurations. Known are, for example, polydimethylsiloxane, poly (methylphenyl) siloxane and poly (dimethylsiloxane / diphenylsiloxane) copolymers. If the alkenyl group is not (only) at the terminal, but is (also) arranged in the polysiloxane polymer chain described above, then in this case it is not pure polydimethylsiloxane, poly (methylphenyl) ) Siloxane, poly (dimethylsiloxane / diphenylsiloxane) copolymer, etc. These polysiloxanes (according to expert practice) according to the invention remain as described above.

Preferably, the residues R ′ in the general formula (2) are each independently a methyl residue, an ethyl residue, a phenyl residue, or an alkenyl residue, wherein at least two residues R ′ represent an olefin Base residue. Particularly preferred is a polysiloxane (a) which is a polydimethylsiloxane, a poly (methylphenyl) siloxane or a dimethylsiloxane-diphenylsiloxane copolymer. In particular, the organopolysiloxane of component a) is polydimethylsiloxane. Since the formula (2) is a structural formula, the siloxane units are repeatedly connected to each other.

At least one organopolysiloxane of component a) comprises at least two alkenyl groups. Such polysiloxanes can usually be crosslinked through these groups, and other organic polysiloxanes containing multiple Si-H groups are added to the composition. An Si-H functional group addition then takes place on the alkenyl group and in this way forms a crosslinked polysiloxane. Preferably, the alkenyl group of polysiloxane a) contains 2 to 10 C atoms. Particularly preferred are the alkenyl systems of the organopolysiloxanes of component a) each independently selected from the group consisting of vinyl, propenyl, allyl, butenyl, pentenyl, hexyl Alkenyl, heptenyl, octenyl, nonenyl and decenyl. These groups are particularly reactive and can therefore be efficiently crosslinked. More preferably, the alkenyl group of the organopolysiloxane of component a) comprises a vinyl group. In particular, the alkenyl group of the organopolysiloxane of component a) is vinyl.

A feature of the present invention is that the organopolysiloxane designed as component a) according to the composition system of the present invention is not crosslinked through the compound containing Si-H group as usual, but is typically crosslinked through a free radical mechanism. . Component a) is obviously included in the cross-linking of component b), which was designed to be free-radical crosslinked in the beginning. It is preferred that the composition according to the present invention does not contain a substance containing more than one Si-H group.

It has been found that the composition according to the invention, which is atypically crosslinked in the above sense, leads to a substantial expansion of the temperature range in which good vibration damping occurs. This is manifested in the fact that the curve progression of tan δ vs. temperature, which is higher than the value of tan δ = 0.5 or 0.8, is greatly expanded compared to the conventional polysilicon composition. It is preferable that the composition according to the present invention does not contain a substance having more than one Si-H group.

The weight-average molecular weight Mw of the organopolysiloxane of the component a) is preferably 31,000 to 2,000,000 g / mol, and particularly preferably 45,000 to 1,000,000 g / mol.

In the composition according to the present invention, based on the solid content of the composition, it is preferable to include one or more organic polysiloxanes of component a) in a total amount of 10 to 90% by weight. It may be an organopolysiloxane containing one component a) or a mixture of organopolysiloxanes of various components a). More preferably, based on the solids content of the composition, the composition according to the invention comprises a total of 20 to 80% by weight, in particular a total of 30 to 60% by weight of the organopolysiloxane.

The composition according to the present invention comprises at least one organopolysiloxane having an aryl group bonded to Si containing at least two radically crosslinkable substituents. Preferably, the organopolysiloxane according to the present invention b) is a composition having an organosiloxane unit such as the general formula (3)

(3) (R " ₃ SiO _1/2 ) _q (R" ₂ SiO) _r (R "SiO _3/2 ) _s (SiO ₂ ) _t ,

0。依據本發明係包含多個鍵結於Si上之芳基。於如式(3)之聚合物中，至少甲基為可自由基交聯的取代基。式(3)不是結構式，所以僅為由有機基矽氧烷單元形成的有機基矽氧烷之組成物，而非其彼此重複連結。 Wherein the residues R "each independently represent an alkyl residue, an aryl residue, a polydiorganosiloxy residue, and based on the number of all the residues R", 0 to 10% represent an OH group, wherein the polymerization Contains at least two methyl groups, and q, r> 0 and s, t

0. According to the present invention, a plurality of aryl groups bonded to Si are included. In the polymer of formula (3), at least a methyl group is a radically crosslinkable substituent. Formula (3) is not a structural formula, so it is only a composition of an organosiloxane formed from an organosiloxane unit, and it is not a repeating connection with each other.

Organic polysiloxanes are preferred b) linear polymers such as the general formula (4)

(4) R ''' ₃ Si-O- (R''' ₂ Si-O) _r -SiR ''' ₃ ,

Where the residues R '' 'each independently represent an alkyl residue or an aryl residue, and based on the number of all residues R' '', up to 10% of the residues R '' 'represent OH groups, of which at least two Each residue R '' 'represents a methyl group, and at least two residues R' '' represent an aryl group; wherein r is a natural number of 2,000 to 6,000. Basically, the residue R ' ' is able to branch through linear polysiloxane in all conceivable and chemically feasible configurations. Known are, for example, polydiphenylsiloxane, poly (methylphenyl) siloxane and poly (dimethylsiloxane / diphenylsiloxane) copolymers.

Preferably, the residues R '' 'in the general formula (4) each independently represent a methyl residue, an ethyl residue, or a phenyl residue, or an OH group, of which at least two residues R' ' 'Represents a phenyl group and at least two residues R' '' represents a methyl residue. Particularly preferred is the aryl group bonded to Si of the organopolysiloxane of component b) is phenyl. More preferably, polysiloxane b) is polydiphenylsiloxane, poly (methylphenyl) siloxane, or a dimethylsiloxane-diphenylsiloxane copolymer. In particular, the organopolysiloxane of component b) is a poly (methylphenyl) siloxane or a dimethylsiloxane-diphenylsiloxane copolymer. Formula (4) is a structural formula, that is, the siloxane units are repeatedly connected to each other.

At least one organopolysiloxane of component b) comprises at least two radically crosslinkable substituents. Such polysiloxanes are usually cross-linked through these groups, in which a radical initiator is added to the composition. Free radicals are then formed, and the free radicals are reorganized to form a cross-linked polysilicon structure. Preferably, the radical-crosslinkable substituent of the organopolysiloxane of component b) is methyl.

The organopolysiloxane of component b) is preferably an alkenyl group which is not bonded to Si, and more preferably has no alkenyl group.

The weight average molecular weight Mw of the organopolysiloxane of the component b) is preferably 31,000 to 1,500,000 g / mol, more preferably 45,000 to 1,200,000 g / mol, and especially 50,000 to 1,000,000 g / mol.

In the composition according to the present invention, based on the solid content of the composition, it is preferable to include one or more organic polysiloxanes of component b) in a total amount of 10 to 90% by weight. It may be an organopolysiloxane containing one component b) or a mixture of organopolysiloxanes of various components b). More preferably, based on the solids content of the composition, the composition according to the invention comprises a total of 20 to 80% by weight, in particular a total of 40 to 70% by weight of component b) organopolysiloxanes.

The weight of the organopolysiloxane according to component a) according to the present invention relative to the organopolysiloxane of component b) is preferably 1: 4 to 3: 1, more preferably 1: 3 to 7: 3, especially 3: 7 to 3: 2.

In addition to the polysiloxanes of components a) and b), other polysiloxanes can be included in the composition according to the invention, which contain neither alkenyl groups nor aryl groups or OH groups. In this case it may be, for example, pure polydimethylsiloxane.

The composition according to the invention comprises at least one free radical initiator. A "free radical initiator" is understood as a compound that undergoes thermal or photochemical decomposition into free radicals and thereby initiates free radical reactions. The free radical initiator is preferably a peroxide. The free radical initiator is selected in particular from the group comprising: bis (4-methylbenzyl) peroxide, dibenzoxyl peroxide, bis (2,4-dichlorobenzoyl)醯), Dicumyl peroxide, Di (4-tert-butylcyclohexyl peroxydicarbonate), Dilauric acid perox, Di (hexadecyl) peroxydicarbonate, Tertiary peroxybenzoic acid Butyl ester, tertiary butyl cumyl peroxide, bis (tertiary butyl) peroxide, bis (tertiary butyl peroxy isopropyl) benzene, 2,5-dimethyl-2,5 -Bis (tri-butylperoxy) hexyne-3 and 3,3,5,7,7-pentamethyl-1,2,4-trioxane.

In the composition according to the present invention, based on the solid content of the composition, it preferably contains a total of 0.3 to 6% by weight, particularly preferably a total of 0.5 to 4% by weight, especially a total of 1 to 3% by weight of a radical initiator. .

The composition according to the present invention preferably contains at least one silicone resin. The silicone resin is preferably selected from the group consisting of MQ resin, MTQ resin, TQ resin, MT resin, and MDT resin. Mixtures of various silicone resins, particularly mixtures of the aforementioned silicone resins, may also be included in the composition according to the present invention. Particularly preferably, the at least one silicone resin is an MQ resin. MQ silicone resins are easily available and are characterized by excellent stability. More preferably, if a plurality of silicone resins are included in the composition according to the present invention, all the silicone resins of the composition according to the present invention are MQ resins.

The weight average molecular weight M _{w of the} at least one silicone resin is preferably 500- <30,000 g / mol. The resin may include an alkenyl group. Suitable silicone resins are, for example: Dow Corning's DC 2-7066; Chenguang Fluoro & Silicone Elastomers Co., Ltd.'s MQ Resin VSR6201; Wacker Silicones 'MQ-RESIN POWDER 803 TF; Momentive Performance Materials' SR 545, or Siltech Silmer VQ9XYL and Silmer Q9XYL.

Preferably, the ratio of the total amount of all silicone resins to the total amount of all polysiloxanes a) and b) and all silicone resins is at most 90% by weight. In an embodiment of the present invention, the ratio of the total amount of all silicone resins to the total amount of all polysiloxanes a) and b) and the total amount of all silicone resins is at least 30% by weight. In another embodiment of the present invention, the ratio of the total amount of all silicone resins to the total amount of all polysiloxanes a) and b) and the total amount of all silicone resins is at least 45% by weight. In particular, a total of 30 to 80% by weight of the silicone resin is contained in the composition according to the present invention based on the total weight of the entire organic polysiloxane and the total silicone resin of the composition.

Preferably, the composition according to the present invention contains at least one solvent. The solvent is preferably selected from: aromatic or aliphatic hydrocarbons (especially toluene, xylene, petroleum ether), aprotic carbonyl compounds (especially ketones, esters and ethers), and inert aprotic solvents ( Especially isopropanol).

In addition to the base polymer, silicone resin, and other components listed so far, the composition according to the present invention may include other components in the sense of additives and additives, such as: anchoring additives; organic and / or inorganic Pigments; fillers, such as carbon black, graphite or carbon nanotubes, and organic and / or inorganic particulates (such as polymethyl methacrylate (PMMA), barium sulfate, or titanium dioxide (TiO ₂ )).

In an embodiment of the present invention, the composition according to the present invention, based on a total of 100 parts by weight of the base polymer and the silicone resin, each independently contains 0.1 to 5 parts by weight of one or more anchoring aids and / or one or more Pigment and / or 0.1 to 50 parts by weight of one or more fillers.

In another embodiment, the composition according to the present invention does not have any components other than the components described so far.

Another object of the present invention is a method for manufacturing a pressure-sensitive adhesive, which comprises thermally crosslinking the composition according to the present invention.

Another object of the present invention is a pressure-sensitive adhesive, which is obtained by thermally crosslinking the composition according to the present invention.

Here, "thermal cross-linking" is understood to be under the influence of heat, under the conditions here, especially under the condition that the composition of the adhesive and the theoretically available connection points are generated, otherwise it is The maximum cross-linking that can be achieved under conditions equivalent to the common cross-linking conditions of polysiloxane pressure-sensitive adhesives.

The temperature at which the quotient (tan δ) obtained from the loss modulus (G ") and the storage modulus (G ') of the pressure-sensitive adhesive according to the present invention reaches its maximum value can be adjusted by changing the resin content. Therefore One of the objects of the present invention is a method for adjusting the temperature (T _{tan δ max} ) at which the pressure-sensitive adhesive obtained by thermally crosslinking the composition according to the present invention containing at least one silicone resin is used. The quotient (tan δ) obtained from the loss modulus (G ") and the storage modulus (G ') reaches its maximum value, of which T _{tan δ max} is kept the same by changing the concentration of the silicone resin. To scale.

In general, it can be said that the increase in the concentration of silicone resin causes the maximum value of tan δ to shift to a higher temperature. The "silicone resin concentration" when a plurality of silicone resins are included in the composition according to the present invention is naturally understood as the total concentration of the silicone resin. The change of the concentration of the silicone resin in the method according to the present invention is preferably 8 to 80% by weight, more preferably 20 to 50% by weight of the silicone resin based on the total amount of the polysiloxane and the silicone resin in the composition. The total content is carried out within a range.

The method according to the present invention described later enables the polysiloxane pressure-sensitive adhesive obtained from the composition to be adjusted to the temperature range expected for the intended use. With a simple test series, pressure-sensitive adhesives with optimized damping characteristics (which is most pronounced at the tan δ maximum) can be manufactured. In addition, the pre-prepared base formulation can be easily "modified" to the desired temperature by adding a corresponding amount of silicone resin b).

The maximum value of the quotient obtained from the loss modulus (G ") and the storage modulus (G ') of the pressure-sensitive adhesive according to the present invention is preferably in a temperature range between -60 ° C and 170 ° C. (tan δ max, measured at 10 rad / s) has a maximum value of 0.5 to 2.1; particularly 0.8 or more; more preferably 1 or more. In this range, excellent (especially acoustic) damping properties are obtained.

It is also preferred that the tan δ of the pressure-sensitive adhesive according to the present invention is at least 0.5 in a temperature range including at least 80K, more preferably at least 150K in a span of -60 ° C to 170 ° C. It is further preferred that the tan δ of the pressure-sensitive adhesive according to the present invention is at least 0.7 in a temperature range including at least 80K, more preferably at least 110K in a span of -60 ° C to 170 ° C. Particularly in a span of -60 ° C to 170 ° C, in a temperature range including at least 40K, more preferably at least 50K, the tan δ of the pressure-sensitive adhesive according to the present invention is at least 1.0.

The composition according to the present invention or the pressure-sensitive adhesive obtained therefrom can be preferably used for the adhesion of acoustic diaphragms, such as those of speaker diaphragms in mobile phones, notebook computers, televisions, and other devices equipped with speakers. Bonding, and bonding of brake system components used in automobiles. For the adhesion of the speaker diaphragm, the pressure-sensitive adhesive is preferably applied to a film with a layer thickness of 5 to 30 μm, for example, by direct coating or lamination, and then applying another film on the empty adhesive side.

Another object of the present invention is a multi-layer composite, which includes: two layers of films whose main constituents are each independently selected from the group consisting of: polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate (PC), polyurethane (PU), thermoplastic polyurethane (TPU), polyethylene naphthalate ( PEN), polyphenylene sulfide (PPS), polyfluorene imine (PI), polyphenylene oxide (PPSU), polyether fluorene (PES), polyfluorene (PSU), polyether sulfoxide (PEI), polyarylene Ester (PAR), polyetheretherketone (PEEK), and polyaryletherketone (PAEK); and a layer of the pressure-sensitive adhesive according to the present invention, wherein the pressure-sensitive adhesive is disposed between the films.

Such a multilayer composite can be particularly suitably used as an acoustic diaphragm in the above-mentioned sense. The main constituent of the two films is particularly preferably polyetheretherketone.

Other application fields of the composition according to the present invention or the pressure-sensitive adhesive derived therefrom are: adhesion on ceilings and floors, house elements and facade elements (such as doors, windows); such as mobile phones, notebook computers, Other adhesives in televisions and other electronic devices (except for speaker diaphragms); adhesives on movable furniture elements (such as drawers); adhesives on automobile and aircraft interior decorative panels; adhesives in kitchen appliances (such as mixers); printing Bonding of moving parts in watches; bonding in mass storage devices of computers or disk storage; other bonding in cars, such as oil pans, dashboards, body parts, door trims, car bodies, roofs , Trunk lid, adhesion to tailgate and window adhesion; especially noise reduction in hood hinges in cars; noise reduction in washing machine and dryer drums; prevention of car window frames and Squeaking between car bodies; bonding of thick metal substrates in shipbuilding, such as bonding of bulwarks and decks; bonding of metal plates in cars, train trailers, and trucks; air conditioning and fans or ventilation Preparation of the adhesive member; and laser optics means and sports equipment (e.g., tennis racket) of the damper. All of the above applications are eager to inhibit the adhesion of vibrations.

    [Example]         Measurement methods    

-Dynamic mechanical analysis

25mm Device: Deformation Controlled Rheometer (ARES), plate / plate,

25mm

Deformation: 1%

Frequency: 10rad / s

Scanning temperature: see Table 2

-Adhesion to steel:

The measurement of the adhesion of steel is performed under the test environment of a temperature of 23 ° C +/- 1 ° C and a relative humidity of 50% +/- 5%. The tape specimen was cut to a width of 20 mm and adhered to a steel plate. The steel plate was cleaned and conditioned before measurement. To do this, first wash the board with acetone, and then let it stand in the air for 5 minutes to evaporate the solvent.

A 50 μm aluminum foil was then used to cover the side of the tape sample facing away from the test substrate, thereby preventing the sample from stretching during measurement. The test specimen is then rolled on a steel substrate. For this purpose, a 2 kg roller was rolled back and forth across the tape 5 times at a rolling speed of 10 m / min. After rolling, the steel plate is directly pushed into a special support, which enables the sample to be pulled out vertically at an angle of 90 °. Adhesion measurement was performed using a Zwick tensile tester.

The measurement results are in N / cm, and three measurements are averaged.

    Composition    

Chemicals used:

Mixture of benzamidine peroxide and dicyclohexyl phthalate-benzamidine peroxide (BPO), 50%

General instructions for formulating compositions according to the invention or manufacturing pressure-sensitive adhesives from these compositions: Blend DC 7956 with the indicated amount (see Table 1 for the amount) and DC 7657 with each indicated amount with DC 7066 as needed . The mixture was homogenized with a magnetic stir bar for 2 hours. Next, the specified amount of BPO was added to 5 ml of toluene and mixed together, and further stirred for one hour.

The resulting mixture was applied in the form of a layer of 50 g / m ² (for measurement of adhesion) or 500 g / m ² (for dynamic mechanical analysis) on a fluorosilicone-PET mounting paper, and at 90 ° C. 2 It was then crosslinked at 170 ° C for 5 minutes. The formulations are listed in Table 1.

Vgl. = Comparative example

The adhesion of the pressure-sensitive adhesives obtained from Compositions 1 to 3 to steel and the maximum value of tan δ in the range of 15K in the temperature range of -60 ° C to 165 ° C were measured. From the numerical values shown in Table 2 below, by plotting the corresponding curve against temperature, a temperature range in which tan δ is at least 0.5 or at least 0.7 or 1.0 is generated.

Hkm = pressure-sensitive adhesive, the number corresponds to the basic composition from Table 1

Mix the DC 7956 servings indicated in Table 3 with the DC 7651, DC 2-7066 servings listed therein with petroleum ether. The mixture was homogenized with a magnetic stir bar for 2 hours. Next, the specified amount of BPO was added to 5 ml of toluene and mixed together, and further stirred for one hour.

The resulting mixture was applied in the form of a layer of 50 g / m ² (for measurement of adhesion) or 500 g / m ² (for dynamic mechanical analysis) on a fluorosilicone-PET mounting paper, and at 90 ° C. 2 It was then crosslinked at 170 ° C for 5 minutes.

Vgl. = Comparative example

The adhesion of the pressure-sensitive adhesives obtained from Compositions 4 and 5 to steel and the maximum value of tan δ in the 15K interval in a temperature range of -60 ° C to 165 ° C were measured. From the numerical values shown in Table 4 below, a temperature range in which tan δ is at least 0.5 or at least 0.7 or 1.0 is generated by plotting a corresponding curve with respect to temperature.

Hkm = pressure-sensitive adhesive, the number corresponds to the basic composition from Table 3

Claims (14)

A pressure-sensitive adhesive composition comprising: a) at least one organopolysiloxane containing at least two alkenyl groups bonded to Si and having a plurality of alkyl groups bonded to Si; b) At least one organopolysiloxane containing at least two radically crosslinkable substituents having a plurality of aryl groups bonded to Si; and c) at least one free radical initiator, The pressure-sensitive adhesive composition is thermally cross-linked to obtain a pressure-sensitive adhesive. In a temperature range between -60 ° C and 170 ° C, the pressure-sensitive adhesive has a loss modulus (G ") and a storage modulus. The maximum value of the quotient (tanδ) obtained by (G ') is 0.8 or more. The pressure-sensitive adhesive composition according to claim 1, wherein the organopolysiloxane of component a) is polydimethylsiloxane. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the alkenyl group bonded to Si of the organopolysiloxane of the component a) is a vinyl group. For example, the pressure-sensitive adhesive composition of claim 1 or 2, wherein the aryl group bonded to Si of the organopolysiloxane of component b) is phenyl. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the weight ratio of the organopolysiloxane of the component a) to the organopolysiloxane of the component b) is 3: 7 to 7 : 3. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the at least one radical initiator is a peroxide. The pressure-sensitive adhesive composition according to claim 1 or 2, which comprises a total of 0.5 to 2% by weight of a radical initiator based on the total weight of the composition. The pressure-sensitive adhesive composition according to claim 1, wherein the composition comprises at least one silicone resin. The pressure-sensitive adhesive composition according to claim 8, wherein the silicone resin is an MQ resin. If the pressure-sensitive adhesive composition of claim 8 or 9 is based on the total weight of all the organopolysiloxane and all the silicone resin of the composition, it contains a total of 30 to 80% by weight of the silicone resin. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the composition comprises at least one solvent. For example, the pressure-sensitive adhesive composition of claim 1, wherein the pressure-sensitive adhesive has a tan δ of at least 0.5 within a temperature range of at least 80K in a span of -60 ° C to 170 ° C. A method for manufacturing a pressure-sensitive adhesive, which comprises thermally crosslinking the pressure-sensitive adhesive composition according to any one of claims 1 to 12. A multilayer composite comprising: two layers of films, the main components of which are independently selected from the group consisting of: polypropylene, polyethylene terephthalate, polybutylene terephthalate Esters, polycarbonates, polyurethanes, thermoplastic polyurethanes, polyethylene naphthalates, polyphenylene sulfide, polyimide, polyphenylene oxide, polyether fluorene, polyfluorene, polyether Hydrazone, polyarylate, polyetheretherketone, and polyaryletherketone; a pressure-sensitive adhesive obtained by thermally crosslinking a layer of the pressure-sensitive adhesive composition according to any one of claims 1 to 12 The pressure-sensitive adhesive is arranged between the films.