Addition-type silicone pressure-sensitive adhesive composition and product

Abstract

The invention provides an addition type organic silicon pressure-sensitive adhesive composition and an addition type organic silicon pressure-sensitive adhesive product. The composition comprises methyl vinyl polysiloxane; a methyl MQ silicone resin; a hydrogen-containing silicone oil crosslinking agent; a release force enhancer; an inhibitor; a solvent; the stripping force reinforcing agent is a double-bond compound containing hydroxyl or alkoxy silane. According to the invention, a double-bond compound containing hydroxyl or alkoxy silane is used as a stripping force reinforcing agent of the addition type organic silicon pressure-sensitive adhesive, and active groups such as hydroxyl and alkoxy silane can be bonded with an adhered object through hydrogen-bond interaction or hydrolytic condensation, so that the stripping strength of the pressure-sensitive adhesive on the adhered object is enhanced; wherein the double bonds can enable the stripping force enhancer to be combined in the pressure-sensitive adhesive through covalent bonds, so that the precipitation of small molecules is greatly reduced, and the stability of the stripping force can be effectively improved. Experimental results show that the stripping force of the pressure-sensitive adhesive on a steel plate can reach 2192 g / inch, and the stripping force is still kept at 2146 g / inch after the pressure-sensitive adhesive is aged for 14 days.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicone pressure sensitive adhesive, in particular to an addition type silicone pressure sensitive adhesive composition and product. BACKGROUND

[0002] The silicone pressure sensitive adhesive is a synthetic product of long-chain siloxane and MQ silicone resin, which has excellent bonding strength, initial adhesion and temperature resistance and weather resistance. It is the only pressure sensitive adhesive that can be used for a long time at-60℃~200℃. At the same time, the silicone pressure sensitive adhesive has a low surface tension, which is not only suitable for bonding high-surface-energy surfaces, but also has unique advantages in bonding low-surface-energy surfaces such as polytetrafluoroethylene, polyethylene and silica products. It has important application value in the fields of electric power, medicine and new energy.

[0003] Peeling strength is a core index for measuring the bonding performance of pressure sensitive adhesive, which directly determines the application stability and reliability in various scenarios. Chinese patent CN108531126A discloses a silicone pressure sensitive adhesive containing boron-modified MQ silicone tackifier, which exhibits excellent peeling strength by introducing the boron-modified tackifier. However, the synthesis process of the silicone tackifier is complex and the cost is high. Moreover, the tackifier is combined with the pressure sensitive adhesive system through non-covalent bonds, which may lead to poor compatibility of the pressure sensitive adhesive and affect the stability of the peeling force of the pressure sensitive adhesive. SUMMARY

[0004] Therefore, the present application provides an addition type silicone pressure sensitive adhesive composition and product. The addition type silicone pressure sensitive adhesive composition provided by the present application has high peeling strength and good peeling force stability.

[0005] The present application provides an addition type silicone pressure sensitive adhesive composition, which comprises:

[0006] 100 parts by mass of methylvinyl polysiloxane;

[0007] 50 parts by mass to 250 parts by mass of methyl MQ silicone resin;

[0008] 1 part by mass to 5 parts by mass of hydrogen-containing silicone oil crosslinking agent;

[0009] 1 part by mass to 10 parts by mass of peeling force enhancer;

[0010] 0.2 parts by mass to 2 parts by mass of inhibitor;

[0011] 50 parts by mass to 400 parts by mass of solvent;

[0012] The peeling force enhancer is a double-bond compound containing hydroxyl or alkoxy silane.

[0013] In some specific implementations, the peeling force enhancer is one or more of a hydroxyallyl ether, a vinyl alkoxysilane, and an allyl phenol.

[0014] In some specific implementations, the hydroxyallyl ether includes one or more of ethylene glycol monoallyl ether, propylene glycol monoallyl ether, glycerol monoallyl ether, diethylene glycol monoallyl ether, polyethylene glycol monoallyl ether, pentaerythritol monoallyl ether, glycerol diallyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, and pentaerythritol triallyl ether.

[0015] The vinyl alkoxysilane includes one or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltriisopropoxysilane, and dimethylvinylethoxysilane.

[0016] The allyl phenol includes one or more of p-allyl phenol, 2-propenyl phenol, o-allyl phenol, and eugenol.

[0017] In some specific implementations, the methyl vinyl polysiloxane has a weight average molecular weight of 400,000 to 900,000.

[0018] The methyl vinyl polysiloxane has a vinyl content of 0.02 wt% to 0.23 wt%.

[0019] In some specific implementations, the methyl MQ silicone resin has an M / Q value of 0.5 to 1.1.

[0020] The methyl MQ silicone resin has a weight average molecular weight of 1,000 to 15,000.

[0021] The methyl MQ silicone resin has a hydroxyl content of 0.2 wt% to 0.9 wt%.

[0022] In some specific implementations, the hydrogen-containing silicone oil crosslinking agent is one or both of a terminal hydrogen-containing silicone oil and a side chain hydrogen-containing silicone oil.

[0023] The hydrogen-containing silicone oil crosslinking agent has a hydrogen content of 0.01 wt% to 2 wt%.

[0024] The hydrogen-containing silicone oil crosslinking agent has a viscosity of 20 mPa·s to 800 mPa·s.

[0025] In some specific implementations, the inhibitor is one or more of ethynylcyclohexanol, methylbutynol, dimethylhexynol, and methylacetylenol.

[0026] The solvent is one or more of a fatty solvent, an aromatic solvent, an ester solvent, and an alcohol solvent.

[0027] In some specific implementations, the composition further comprises a catalyst.

[0028] The application also provides an addition type silicone pressure sensitive adhesive product, comprising a substrate and a pressure sensitive adhesive layer formed on the surface of the substrate, wherein the pressure sensitive adhesive layer is obtained by curing the composition according to the above technical solution.

[0029] In some specific implementations, the substrate is one or more of polyester, polyimide, polyolefin, paper and fluorocarbon material.

[0030] The addition type silicone pressure sensitive adhesive composition provided by the application comprises 100 parts by mass of methyl vinyl polysiloxane; 50 parts by mass to 250 parts by mass of methyl MQ silicone resin; 1 part by mass to 5 parts by mass of hydrogen-containing silicone oil crosslinking agent; 1 part by mass to 10 parts by mass of peel strength enhancer; 0.2 parts by mass to 2 parts by mass of inhibitor; and 50 parts by mass to 400 parts by mass of solvent; and the peel strength enhancer is a double bond compound containing hydroxyl or alkoxy silane. The double bond compound containing hydroxyl or alkoxy silane is used as the peel strength enhancer of the addition type silicone pressure sensitive adhesive, on the one hand, the active groups such as hydroxyl and alkoxy silane in the double bond compound can be bonded to the adherend through hydrogen bonding or hydrolysis condensation, thereby enhancing the peel strength of the pressure sensitive adhesive to the adherend; on the other hand, the double bond in the double bond compound can make the peel strength enhancer covalently bond in the pressure sensitive adhesive, greatly reducing the precipitation of small molecules, and effectively improving the stability of the peel strength. Experimental results show that the peel strength of the addition type silicone pressure sensitive adhesive prepared by the application to the steel plate can reach 2192 g / inch, and still maintains 2146 g / inch after aging for 14 days. DETAILED DESCRIPTION

[0031] It should be understood that the expression "one or more of" individually includes each object recited after the expression and various different combinations of two or more of the recited objects, unless otherwise understood from the context and usage. The expression "and / or" in combination with three or more recited objects should be understood to have the same meaning, unless otherwise understood from the context.

[0032] The use of the expressions "comprise", "have" or "contain", including their grammatical synonyms, should generally be understood to be open and non-limiting, for example, not excluding other non-recited elements or steps, unless otherwise specifically stated or understood from the context.

[0033] It should be understood that the order of steps or the order of performing certain actions is not important as long as the application is still operable. In addition, two or more steps or actions can be performed simultaneously.

[0034] The application provides an addition type silicone pressure sensitive adhesive composition, comprising:

[0035] 100 parts by mass of methyl vinyl polysiloxane;

[0036] 50 parts by mass to 250 parts by mass of methyl MQ silicone resin;

[0037] 1 part by mass to 5 parts by mass of hydrogen-containing silicone oil crosslinking agent;

[0038] 1 part by mass to 10 parts by mass of peeling strength enhancer;

[0039] 0.2 parts by mass to 2 parts by mass of inhibitor;

[0040] 50 parts by mass to 400 parts by mass of solvent;

[0041] The peeling strength enhancer is a double bond-containing compound containing a hydroxyl group or an alkoxy silane.

[0042] The addition type silicone pressure-sensitive adhesive composition provided in the present application includes methyl vinyl polysiloxane and methyl MQ silicone resin, which are important components for forming an addition type silicone pressure-sensitive adhesive. In some specific implementations, the weight average molecular weight of the methyl vinyl polysiloxane is 400,000 to 900,000, preferably 500,000 to 800,000, more preferably 600,000 to 700,000, such as 600,000, 650,000, 850,000, or 900,000, etc.; the vinyl content of the methyl vinyl polysiloxane is 0.02wt% to 0.23wt%, preferably 0.02wt% to 0.15wt%, more preferably 0.03wt% to 0.08wt%, such as 0.03wt%, 0.08wt%, 0.16wt%, or 0.23wt%, etc.

[0043] In some specific implementations, the M / Q value of the methyl MQ silicone resin is 0.5 to 1.1, preferably 0.6 to 0.9, such as 0.6, 0.7, or 0.8, etc.; the weight average molecular weight of the methyl MQ silicone resin is 1,000 to 15,000, preferably 2,000 to 10,000, more preferably 3,000 to 8,000, such as 3,000, 5,000, or 8,000, etc.; the hydroxyl content of the methyl MQ resin is 0.2wt% to 0.9wt%, preferably 0.2wt% to 0.7wt%, more preferably 0.3wt% to 0.5wt%, such as 0.3wt%, 0.4wt%, or 0.5wt%.

[0044] The addition type silicone pressure sensitive adhesive composition provided by the application comprises a hydrogen-containing silicone oil crosslinking agent, which crosslinks methyl vinyl polysiloxane and MQ silicone resin into a stable three-dimensional network structure through a hydrosilylation reaction, thereby imparting excellent peel strength and durability to the pressure sensitive adhesive. In some specific implementations, the hydrogen-containing silicone oil crosslinking agent includes but is not limited to end hydrogen-containing silicone oil and side chain hydrogen-containing silicone oil, etc., and can be one or both of them. When the hydrogen-containing silicone oil crosslinking agent is a combination of two substances, the application does not have special restrictions on the content of each specific substance. In some specific implementations, the hydrogen content of the hydrogen-containing silicone oil crosslinking agent is 0.01wt%~2wt%, preferably 0.02wt%~1wt%, and more preferably 0.04wt%~0.8wt%; the viscosity of the hydrogen-containing silicone oil crosslinking agent at 25°C is 20mPa·s~800mPa·s, preferably 40mPa·s ~500mPa·s, and more preferably 50mPa·s~400mPa·s. When the hydrogen-containing silicone oil crosslinking agent is a side chain hydrogen-containing silicone oil, its hydrogen content is 0.01wt%~2wt%, preferably 0.02wt%~1wt%, and more preferably 0.04wt%~0.8wt%, for example 0.6wt% or 0.9wt%, etc.; its viscosity at 25°C is 20mPa·s~800mPa·s, preferably 40mPa·s ~500mPa·s, and more preferably 50mPa·s~400mPa·s, for example 100mPa·s or 85mPa·s, etc. When the hydrogen-containing silicone oil crosslinking agent is an end hydrogen-containing silicone oil, its hydrogen content is 0.01wt%~2wt%, preferably 0.02wt%~1wt%, and more preferably 0.04wt%~0.8wt%, for example 0.04wt% or 0.05wt%, etc.; its viscosity at 25°C is 20mPa·s~800mPa·s, preferably 40mPa·s ~500mPa·s, and more preferably 50mPa·s~400mPa·s, for example 80mPa·s or 90mPa·s, etc.

[0045] The addition type silicone pressure sensitive adhesive composition provided by the application comprises a peel strength enhancer, which is a double bond compound containing a hydroxyl group or an alkoxy silane. On the one hand, the active groups such as the hydroxyl group and the alkoxy silane in the peel strength enhancer can bond with the adherend through hydrogen bonding or hydrolysis condensation, thereby enhancing the peel strength of the pressure sensitive adhesive to the adherend. On the other hand, the double bond in the peel strength enhancer can make the peel strength enhancer covalently bond in the pressure sensitive adhesive, greatly reducing the precipitation of small molecules, and effectively improving the stability of the peel strength.

[0046] In some specific embodiments, the peeling force enhancer includes, but is not limited to, a hydroxyallyl ether, a vinylalkoxysilane, an allyl phenol, etc., and can be one or more of them. When the peeling force enhancer is a combination of multiple substances, the present application does not have a special limitation on the proportion of each specific substance. In some specific embodiments, the hydroxyallyl ether includes, but is not limited to, ethylene glycol monoallyl ether, propylene glycol monoallyl ether, glycerol monoallyl ether, diethylene glycol monoallyl ether, polyethylene glycol monoallyl ether, pentaerythritol monoallyl ether, glycerol diallyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, or pentaerythritol triallyl ether, etc., and can be one or more of them. Preferably, it is a diol monoallyl ether or a pentaerythritol triallyl ether. In some specific embodiments, the vinylalkoxysilane includes, but is not limited to, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, vinyltriisopropoxysilane, or dimethylvinylethoxysilane, etc., and can be one or more of them. Preferably, it is vinyltrimethoxysilane. In some specific embodiments, the allyl phenol includes, but is not limited to, p-allyl phenol, 2-propenyl phenol, o-allyl phenol, eugenol, etc., and can be one or more of them.

[0047] The addition type silicone pressure-sensitive adhesive composition provided by the present application includes an inhibitor. In some specific embodiments, the inhibitor includes, but is not limited to, ethynylcyclohexanol, methylbutynol, dimethylhexynol, methylacetylene alcohol, etc., and can be one or more of them. When the inhibitor is a combination of multiple substances, the present application does not have a special limitation on the proportion of each specific substance.

[0048] The addition type silicone pressure-sensitive adhesive composition provided by the present application includes a solvent for dissolving materials. In some specific embodiments, the solvent includes, but is not limited to, a fatty solvent, an aromatic solvent, an ester solvent, an alcohol solvent, etc., and can be one or more of them. When the solvent is a combination of multiple substances, the present application does not have a special limitation on the proportion of each specific substance. In some specific embodiments, the fatty solvent includes, but is not limited to, cyclohexane or heptane, etc.; the aromatic solvent includes, but is not limited to, benzene, toluene, or xylene, etc.; the ester solvent includes, but is not limited to, methyl acetate, ethyl acetate, or butyl acetate, etc.; and the alcohol solvent includes, but is not limited to, methanol, ethanol, or isopropyl alcohol, etc. In some specific embodiments, the solvent is preferably xylene, ethyl acetate, or isopropyl alcohol.

[0049] The addition type silicone pressure-sensitive adhesive composition provided by the present application can be used to prepare pressure-sensitive adhesives with different solid contents by adjusting the amount of solvent, so as to meet the application requirements under various conditions.

[0050] The content of the methyl MQ silicone resin is 50-250 parts by mass, preferably 100-230 parts by mass, and more preferably 180-220 parts by mass, based on 100 parts by mass of the methyl vinyl polysiloxane; the content of the hydrogen-containing silicone oil crosslinking agent is 1-5 parts by mass, preferably 2-4 parts by mass; the content of the release force enhancer is 1-10 parts by mass, preferably 2-8 parts by mass, and more preferably 3-6 parts by mass; the content of the inhibitor is 0.2-2 parts by mass, preferably 0.5-1.5 parts by mass; and the content of the solvent is 50-400 parts by mass, preferably 120-280 parts by mass, and more preferably 150-250 parts by mass.

[0051] The method for preparing the composition is not particularly limited, and the materials can be directly mixed. Specifically, the composition is prepared according to the following method:

[0052] S1: The methyl vinyl polysiloxane, the methyl MQ silicone resin and the solvent are mixed and dissolved to obtain a mixed solution;

[0053] S2: The mixed solution prepared in step S1 is mixed with the hydrogen-containing silicone oil crosslinking agent, the release force enhancer and the inhibitor to obtain the addition-type silicone pressure-sensitive adhesive composition.

[0054] The methyl vinyl polysiloxane, the methyl MQ silicone resin and the solvent are first mixed and dissolved, and the mixing and dissolving are preferably carried out under heating. In some specific embodiments, the temperature of the heating is 120-180°C, preferably 140-160°C, and the time is 1-3 hours, preferably 1.5-2.5 hours. The mixing method is not particularly limited, and the mixing is preferably carried out under stirring.

[0055] After the mixed solution is obtained, the mixed solution is cooled to room temperature, and then mixed with the hydrogen-containing silicone oil crosslinking agent, the release force enhancer and the inhibitor. The mixing method is not particularly limited, and the mixing is preferably carried out under stirring.

[0056] The addition-type silicone pressure-sensitive adhesive composition further comprises a catalyst for curing the above-mentioned materials. In some specific embodiments, the catalyst is a platinum catalyst, such as Karstedt catalyst, etc. In some specific embodiments, the mass ratio of the catalyst to the composition (i.e., the composition comprising the methyl vinyl polysiloxane, the methyl MQ silicone resin, the hydrogen-containing silicone oil crosslinking agent, the release force enhancer, the inhibitor and the solvent) is 0.1-5:100, preferably 0.3-1.5:100.

[0057] The application also provides an addition type silicone pressure sensitive adhesive product, comprising a substrate and a pressure sensitive adhesive layer formed on the surface of the substrate, wherein the pressure sensitive adhesive layer is obtained by curing the composition according to the above technical solution.

[0058] The addition type silicone pressure sensitive adhesive product provided by the application comprises the pressure sensitive adhesive layer obtained by curing the composition according to the above technical solution, and comprises a substrate and a pressure sensitive adhesive layer formed on the surface of the substrate, and the pressure sensitive adhesive layer is used to bond the layers of materials. In some specific embodiments, the substrate is one or more of polyester, polyimide, polyolefin, paper and fluorocarbon material.

[0059] The addition type silicone pressure sensitive adhesive product provided by the application can further comprise other layers formed on the pressure sensitive adhesive layer, which is not particularly limited in the application and can be selected according to actual use requirements.

[0060] The application also provides a preparation method of the addition type silicone pressure sensitive adhesive product, comprising the following steps:

[0061] The composition comprising methyl vinyl polysiloxane, methyl MQ silicone resin, hydrogen-containing silicone oil crosslinking agent, release force enhancer, inhibitor and solvent is mixed with a catalyst, coated on a substrate and cured to obtain the addition type silicone pressure sensitive adhesive product.

[0062] The application does not have special limitations on the coating method and parameters, and the coating can be performed according to requirements. In some specific embodiments, the curing temperature is 120℃-180℃, preferably 150℃, and the time is 1min-5min, preferably 2min.

[0063] The addition type silicone pressure sensitive adhesive composition provided by the application comprises 100 parts by mass of methyl vinyl polysiloxane; 50-250 parts by mass of methyl MQ silicone resin; 1-5 parts by mass of hydrogen-containing silicone oil crosslinking agent; 1-10 parts by mass of release force enhancer; 0.2-2 parts by mass of inhibitor; and 50-400 parts by mass of solvent; and the release force enhancer is a double bond compound containing hydroxyl or alkoxy silane. The double bond compound containing hydroxyl or alkoxy silane is used as the release force enhancer of the addition type silicone pressure sensitive adhesive, on the one hand, the active groups such as hydroxyl and alkoxy silane in the double bond compound can be bonded to the adherend through hydrogen bonding or hydrolysis condensation, thereby enhancing the release strength of the pressure sensitive adhesive to the adherend; on the other hand, the double bond in the double bond compound can make the release force enhancer covalently bond in the pressure sensitive adhesive, greatly reducing the precipitation of small molecules, and effectively improving the stability of the release force. Experimental results show that the release force of the addition type silicone pressure sensitive adhesive prepared by the application to the steel plate can reach 2192g / inch, and still remains 2146g / inch after aging for 14 days.

[0064] The application will be further described in connection with the following examples. The scope of the protection of the application is not limited by the examples.

[0065] Example 1

[0066] (1) Preparation of raw materials:

[0067] Methyl vinyl polysiloxane: vinyl content of 0.16wt%, weight average molecular weight of 650,000;

[0068] Methyl MQ silicone resin: M / Q value of 0.6, weight average molecular weight of 8000, hydroxyl content of 0.3wt%;

[0069] Hydrogen-containing silicone oil crosslinking agent: side chain hydrogen-containing silicone oil, hydrogen content of 0.6wt%, viscosity of 100mPa·s;

[0070] Peeling strength enhancer: ethylene glycol monoallyl ether;

[0071] Inhibitor: ethynylcyclohexanol;

[0072] Solvent: xylene.

[0073] (2) Preparation of pressure-sensitive adhesive:

[0074] 1) 100 parts of methyl vinyl polysiloxane, 170 parts of methyl MQ silicone resin, and 200 parts of xylene were added to a reaction kettle, heated to 160°C, and stirred for 3h to fully dissolve the components;

[0075] 2) After the mixture in step 1) was cooled, 2 parts of side chain hydrogen-containing silicone oil, 1 part of ethylene glycol monoallyl ether, and 1 part of ethynylcyclohexanol were added, and stirred again to obtain the high peeling strength addition type silicone pressure-sensitive adhesive.

[0076] Example 2

[0077] (1) Preparation of raw materials:

[0078] Methyl vinyl polysiloxane: vinyl content of 0.23wt%, weight average molecular weight of 400,000;

[0079] Methyl MQ silicone resin: M / Q value of 1.0, weight average molecular weight of 1500, hydroxyl content of 0.4wt%;

[0080] Hydrogen-containing silicone oil crosslinking agent: side chain hydrogen-containing silicone oil, hydrogen content of 0.9wt%, viscosity of 85mPa·s; end hydrogen-containing silicone oil, hydrogen content of 0.05wt%, viscosity of 70mPa·s;

[0081] Peeling strength enhancer: vinyltrimethoxysilane;

[0082] Inhibitor: methylbutynol;

[0083] Solvent: ethyl acetate.

[0084] (2) Preparation of pressure-sensitive adhesive:

[0085] 1) 100 parts of methyl vinyl polysiloxane, 50 parts of methyl MQ silicone resin, 50 parts of ethyl acetate were added into a reaction kettle, heated to 170°C, and stirred for 2 h to make the components fully dissolved;

[0086] 2) After the mixture in step 1) was cooled, 4 parts of side-chain hydrogen-containing silicone oil, 2 parts of terminal hydrogen-containing silicone oil, 10 parts of vinyl trimethoxysilane, and 0.2 parts of methyl butynol were added, and then stirred uniformly again to prepare the high-peeling-strength addition-type silicone pressure-sensitive adhesive.

[0087] Example 3

[0088] (1) Preparation of raw materials:

[0089] Methyl vinyl polysiloxane: vinyl content of 0.03 wt%, weight average molecular weight of 600,000;

[0090] Methyl MQ silicone resin: M / Q value of 0.7, weight average molecular weight of 4,000, hydroxyl content of 0.5 wt%;

[0091] Hydrogen-containing silicone oil crosslinking agent: side-chain hydrogen-containing silicone oil, hydrogen content of 0.9 wt%, viscosity of 85 mPa·s;

[0092] Peeling strength enhancer: p-allylphenol, eugenol;

[0093] Inhibitor: dimethyl hexyne alcohol;

[0094] Solvent: isopropyl alcohol.

[0095] (2) Preparation of pressure-sensitive adhesive:

[0096] 1) 100 parts of methyl vinyl polysiloxane, 190 parts of methyl MQ silicone resin, and 280 parts of isopropyl alcohol were added into a reaction kettle, heated to 180°C, and stirred for 1 h to make the components fully dissolved;

[0097] 2) After the mixture in step 1) was cooled, 1 part of side-chain hydrogen-containing silicone oil, 1 part of p-allylphenol, 1 part of eugenol, and 1 part of dimethyl hexyne alcohol were added, and then stirred uniformly again to prepare the high-peeling-strength addition-type silicone pressure-sensitive adhesive.

[0098] Example 4

[0099] (1) Preparation of raw materials:

[0100] Methyl vinyl polysiloxane: vinyl content of 0.08 wt%, weight average molecular weight of 900,000;

[0101] Methyl MQ silicone resin: M / Q value is 0.8, weight average molecular weight is 3000, hydroxyl content is 0.5wt%;

[0102] Hydrogen-containing silicone oil crosslinking agent: side chain hydrogen-containing silicone oil, hydrogen content is 0.6wt%, viscosity is 100mPa·s; end hydrogen-containing silicone oil, hydrogen content is 0.04wt%, viscosity is 90mPa·s;

[0103] Peeling force enhancer: pentaerythritol monoallyl ether;

[0104] Inhibitor: methyl butynol;

[0105] Solvent: xylene.

[0106] (2) Preparation of pressure-sensitive adhesive:

[0107] 1) 100 parts of methyl vinyl polysiloxane, 220 parts of methyl MQ silicone resin, 300 parts of xylene were added into a reaction kettle, heated to 170℃, and stirred for 3h to make the components fully dissolved;

[0108] 2) After the mixture in step 1) was cooled, 2 parts of side chain hydrogen-containing silicone oil, 0.5 parts of end hydrogen-containing silicone oil, 3 parts of pentaerythritol monoallyl ether, 1 part of methyl butynol were added, and then stirred uniformly to prepare the high peeling strength addition type organic silicon pressure-sensitive adhesive.

[0109] Example 5

[0110] (1) Raw material preparation:

[0111] Methyl vinyl polysiloxane: vinyl content is 0.02wt%, weight average molecular weight is 850,000;

[0112] Methyl MQ silicone resin: M / Q value is 0.9, weight average molecular weight is 2000, hydroxyl content is 0.5wt%;

[0113] Hydrogen-containing silicone oil crosslinking agent: side chain hydrogen-containing silicone oil, hydrogen content is 2wt%, viscosity is 800mPa·s;

[0114] Peeling force enhancer: vinyl triethoxysilane, vinyl tri(2-methoxyethoxy)silane;

[0115] Inhibitor: methyl butynol;

[0116] Solvent: xylene.

[0117] (2) Preparation of pressure-sensitive adhesive:

[0118] 1) Add 100 parts of methyl vinyl polysiloxane, 150 parts of methyl MQ silicone resin and 400 parts of xylene to the reactor, heat to 170°C and stir for 3 hours to fully dissolve all components;

[0119] 2) After the mixture in step 1) has cooled, add 2 parts of side-chain hydrogen-containing silicone oil, 1 part of vinyltriethoxysilane, 2 parts of vinyltri(2-methoxyethoxy)silane, and 2 parts of methylbutynol to it, and stir it evenly again to obtain the high peel strength addition-type silicone pressure-sensitive adhesive.

[0120] Comparative Example 1

[0121] The silicone pressure-sensitive adhesive was prepared according to Example 1, except that ethylene glycol monoallyl ether was not added, while other operations and conditions remained the same.

[0122] Comparative Example 2

[0123] The silicone pressure-sensitive adhesive was prepared according to Example 2, except that vinyltrimethoxysilane was not added, while other operations and conditions remained the same.

[0124] Comparative Example 3

[0125] The silicone pressure-sensitive adhesive was prepared according to Example 3, except that p-allylphenol was not added, while other operations and conditions remained the same.

[0126] Comparative Example 4

[0127] The silicone pressure-sensitive adhesive was prepared according to Example 4, except that pentaerythritol monoallyl ether was not added, while other operations and conditions remained unchanged.

[0128] Comparative Example 5

[0129] The silicone pressure-sensitive adhesive was prepared according to Example 5, except that vinyltriethoxysilane and vinyltri(2-methoxyethoxy)silane were not added, while other operations and conditions remained unchanged.

[0130] The silicone pressure-sensitive adhesives prepared in the examples and comparative examples were used to prepare silicone protective films. The specific preparation process is as follows: 1 part of a caster catalyst with a platinum content of 5000 ppm was added to 100 parts of the pressure-sensitive adhesives prepared in the examples and comparative examples. Ethyl acetate can be added as needed to dilute and reduce the viscosity. After mixing evenly, the adhesive solution was coated on a 50 μm thick PET substrate, cured at 150°C for 2 min, and then laminated with a fluorine film to finally obtain the pressure-sensitive adhesive product.

[0131] The peel strength of the above pressure-sensitive adhesive products was tested according to the test method of GBT2792-1998, "Test Method for Peel Strength of Adhesive Tapes". The data changes after 7 days and 14 days of aging were also tested. The test data results are summarized in Table 1.

[0132] Table 1 Summary of preparation process and test data of pressure-sensitive adhesive products

[0133]

[0134] As shown in Table 1, the peel strength of the addition type silicone pressure-sensitive adhesive prepared in Examples 1-5 of the present application is improved to varying degrees compared with the respective comparative examples, and the peel strength remains stable after aging for 7 days and 14 days without significant decay. It can be seen that the peel strength of the pressure-sensitive adhesive is significantly improved by introducing the peel strength enhancer containing active groups such as hydroxyl and alkoxy silane. At the same time, the double bond contained in the peel strength enhancer can be firmly combined in the pressure-sensitive adhesive through covalent bond, which significantly improves the peel strength stability of the pressure-sensitive adhesive after aging.

[0135] The above description is merely preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art, according to the technical range disclosed in the present application and the application concept, makes equivalent replacement or change to the technical solution and application concept of the present application within the technical range disclosed in the present application, which should be covered in the protection scope of the present application.

Claims

1. An addition-type silicone pressure-sensitive adhesive composition, comprising: 100 parts by mass of a methylvinyl polysiloxane; 50 to 250 parts by mass of a methyl MQ silicone resin; 1 to 5 parts by mass of a hydrogen-containing silicone oil crosslinking agent; 1 to 10 parts by mass of a peel strength enhancer; 0.2 to 2 parts by mass of an inhibitor; 50 to 400 parts by mass of a solvent; the peel strength enhancer is a double bond-containing compound containing a hydroxyl group or an alkoxy silane.

2. The composition of claim 1, wherein, the peel strength enhancer is one or more of a hydroxyallyl ether, a vinylalkoxy silane, and an allyl phenol.

3. The composition of claim 2, wherein, the hydroxyallyl ether includes one or more of ethylene glycol monoallyl ether, propylene glycol monoallyl ether, glycerol monoallyl ether, diethylene glycol monoallyl ether, polyethylene glycol monoallyl ether, pentaerythritol monoallyl ether, glycerol diallyl ether, trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, and pentaerythritol triallyl ether; the vinylalkoxy silane includes one or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, vinyltriisopropoxysilane, and dimethylvinylethoxysilane; the allyl phenol includes one or more of p-allyl phenol, 2-propenyl phenol, o-allyl phenol, and eugenol.

4. The composition according to any one of claims 1 to 3, characterized in that, the methylvinyl polysiloxane has a weight average molecular weight of 400,000 to 900,000; the methylvinyl polysiloxane has a vinyl content of 0.02 wt% to 0.23 wt%.

5. The composition according to any one of claims 1 to 3, wherein the methyl MQ silicone resin has an M / Q value of 0.5 to 1.1; the methyl MQ silicone resin has a weight average molecular weight of 1,000 to 15,000; the methyl MQ silicone resin has a hydroxyl content of 0.2 wt% to 0.9 wt%.

6. The composition according to any one of claims 1 to 3, wherein the hydrogen-containing silicone oil crosslinking agent is one or both of a terminal hydrogen-containing silicone oil and a side chain hydrogen-containing silicone oil; the hydrogen-containing silicone oil crosslinking agent has a hydrogen content of 0.01 wt% to 2 wt%; the hydrogen-containing silicone oil crosslinking agent has a viscosity of 20 mPa-s to 800 mPa-s.

7. The composition according to any one of claims 1 to 3, wherein the inhibitor is one or more of ethynylcyclohexanol, methylbutynol, dimethylhexynol, and methylacetylenol; the solvent is one or more of a fatty solvent, an aromatic solvent, an ester solvent, and an alcohol solvent.

8. The composition according to any one of claims 1 to 3, wherein a catalyst is further included.

9. An addition-type silicone pressure sensitive adhesive article, characterized by, a substrate and a pressure-sensitive adhesive layer formed on a surface of the substrate, the pressure-sensitive adhesive layer being obtained by curing the composition of any one of claims 1 to 8.

10. The article of claim 9, wherein, the substrate is one or more of a polyester, a polyimide, a polyolefin, paper, and a fluorocarbon material.

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