Pressure sensitive adhesive composition containing carboxylic acid tackifier and preparation method thereof

Abstract

The invention provides a pressure-sensitive adhesive composition containing a carboxylic acid tackifier and a preparation method of the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition comprises an adhesive matrix, a liquid tackifier and a cross-linking agent, the liquid tackifier comprises a carboxylic acid tackifier, and the carboxylic acid tackifier is selected from at least one of C10-C25 unsaturated carboxylic acid and oligomeric acid of the C10-C25 unsaturated carboxylic acid. According to the pressure-sensitive adhesive composition containing the carboxylic acid tackifier, the initial adhesion performance, the impact resistance and the adhesion performance to low-polarity plates are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives or adhesive tapes, and more specifically to a pressure-sensitive adhesive composition containing an oligomeric acid tackifier and a method for preparing the pressure-sensitive adhesive composition. Background Art

[0002] Improving the performance of adhesives has always been a technology that people pay attention to. In order to meet increasingly stringent environmental requirements, more and more researchers are seeking to improve the bonding properties of adhesives while also hoping that adhesives are made of environmentally friendly materials from biological sources, especially adhesives used in daily necessities such as furniture and home appliances.

[0003] The application of oligomeric organic carboxylic acids (hereinafter referred to as oligomeric acids) in adhesives is mainly used as structural units of various polyester resins or participates in polymerization reactions to prepare adhesive materials. For example, oligomeric acids are used as structural units of hot melt adhesives containing polyurethane systems and condensed with polyamine functional groups to prepare polyamide resins; oligomeric acids react with epoxy resins to prepare PSA precursors; oligomeric acids are used to synthesize polyester polyols, etc., to further give adhesive compositions excellent bonding properties. However, to date, it has not been found that oligomeric acids are added to pressure-sensitive adhesives without participating in polymerization reactions and improving the bonding properties of adhesives.

[0004] In addition, terpene resins, rosin resins, hydrogenated petroleum resins, etc. are often used as tackifying resins in pressure-sensitive adhesives to improve the adhesive properties of the adhesive. However, for pressure-sensitive adhesives using these common tackifying resins, although they have good adhesive strength, the initial adhesion performance is low and cannot meet the daily application requirements of high initial adhesion performance. Moreover, such pressure-sensitive adhesives have poor adhesion to low-polarity substrates and are limited in the bonding application of low-polarity substrates. Summary of the invention

[0005] In view of the above, the object of the present invention is to provide a pressure-sensitive adhesive composition and an adhesive sheet containing an oligomeric acid, wherein the oligomeric acid is used alone as a tackifier or is mixed with a conventional tackifying resin to significantly improve the initial adhesion, impact resistance and adhesion to low-polarity substrates of the pressure-sensitive adhesive composition or the adhesive sheet.

[0006] Furthermore, another object of the present invention is to provide a method for preparing a pressure-sensitive adhesive composition and an adhesive sheet containing an oligomeric acid. Since the oligomeric acid is compatible with the pressure-sensitive adhesive and can be easily mixed evenly, the method of the present invention can easily prepare a pressure-sensitive adhesive composition and an adhesive sheet having the above-mentioned excellent properties.

[0007] Furthermore, another object of the present invention is to provide use of the oligomeric acid as a tackifier in a pressure-sensitive adhesive composition or an adhesive sheet.

[0008] The above-mentioned object of the present invention is achieved through the following technical solutions.

[0009] In one aspect, the present invention provides a pressure-sensitive adhesive composition, comprising an adhesive matrix, a liquid tackifier and a crosslinking agent, wherein the liquid tackifier comprises a carboxylic acid tackifier, and the carboxylic acid tackifier is selected from C 10 ~C 25 Unsaturated carboxylic acid and C 10 ~C 25 At least one of the oligomeric acids of unsaturated carboxylic acids.

[0010] Optionally, the carboxylic acid tackifier is selected from C 15 ~C 20 Unsaturated carboxylic acid and C 15 ~C 20 At least one of the oligomeric acids of unsaturated carboxylic acids; preferably selected from C 16 ~C 18 Unsaturated carboxylic acid and C 16 ~C 18 At least one of the oligomeric acids of unsaturated carboxylic acids.

[0011] Optionally, the carboxylic acid tackifier is selected from the oligomeric acid, and the degree of polymerization of the oligomeric acid is 1-10, preferably 1-6, even preferably 2-6, and more preferably 2-4.

[0012] Optionally, the liquid tackifier further comprises one or more of a liquid hydrocarbon tackifier, a terpene tackifier resin and a rosin tackifier resin.

[0013] Optionally, based on the weight of the adhesive matrix, the content of the liquid tackifier is 1 to 45%.

[0014] Optionally, based on the weight of the adhesive matrix, the content of the carboxylic acid tackifier is 1 to 25%, preferably 2 to 25%, even more preferably 2 to 20%, and more preferably 3 to 15%.

[0015] Optionally, the carboxylic acid viscosity enhancer is selected from oleic acid, linoleic acid, linolenic acid, dimer acid or trimer acid of oleic acid, linoleic acid, linolenic acid, and a mixture of two or more thereof.

[0016] Optionally, the adhesive matrix is ​​an acrylic adhesive.

[0017] In another aspect, the present invention provides a method for preparing the pressure-sensitive adhesive composition, comprising: adding a carboxylic acid tackifier and a cross-linking agent to an adhesive matrix; and stirring and mixing the mixture to obtain the pressure-sensitive adhesive composition.

[0018] In another aspect, the present invention provides a pressure-sensitive adhesive sheet, comprising the pressure-sensitive adhesive composition and optionally an adhesive substrate.

[0019] On the other hand, the present invention provides a method for preparing a pressure-sensitive adhesive sheet, comprising: coating the above-mentioned pressure-sensitive adhesive composition on a substrate to form a coating layer; and laminating another substrate on the coating layer and applying pressure, and then removing the substrates on both sides of the coating layer to obtain a double-sided substrate-free adhesive sheet, or removing any of the substrates on both sides of the coating layer or not removing any substrate to obtain a substrate-containing adhesive sheet.

[0020] In another aspect, the present invention provides a use of a carboxylic acid as a tackifier in a pressure-sensitive adhesive composition, wherein the carboxylic acid is selected from C 10 ~C 25 Unsaturated carboxylic acid and C 10 ~C 25 At least one of the oligomeric acids of unsaturated carboxylic acids.

[0021] The present invention can produce the following beneficial technical effects:

[0022] The present invention adds unsaturated carboxylic acid or its oligomeric acid as carboxylic acid tackifier to pressure-sensitive adhesive composition for the first time and carboxylic acid tackifier does not participate in or does not participate in the polymerization reaction of adhesive substantially. Because carboxylic acid tackifier has lower glass transition temperature Tg, good flexibility and good compatibility with pressure-sensitive adhesive, the initial tack performance, impact resistance and bonding performance to low-polarity sheet of adhesive composition of the present invention are significantly improved. Therefore, the present invention solves the problems such as poor initial tack performance, poor impact resistance and poor bonding force to low-polarity substrate of adhesive when conventional liquid resin is used as tackifier. Moreover, carboxylic acid tackifier of the present invention can be an organic acid of plant origin, so adhesive composition of the present invention is an environmentally friendly adhesive material. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described in combination with the following specific implementation methods. Obviously, the specific implementation methods described are part of the implementation methods of the present invention. Based on the described implementation methods of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] According to one aspect of the present invention, a pressure-sensitive adhesive composition is provided, comprising an adhesive matrix, a liquid tackifier and a crosslinking agent, wherein the liquid tackifier comprises a carboxylic acid tackifier, and the carboxylic acid tackifier is selected from C 10 ~C 25 Unsaturated carboxylic acid and C 10~C 25 At least one of the oligomeric acids of unsaturated carboxylic acids. The carboxylic acid viscosity enhancer according to the present invention is preferably a liquid C 10 ~C 25 Unsaturated carboxylic acid or its oligomeric acid, because the liquid unsaturated carboxylic acid or its oligomeric acid has a lower glass transition temperature Tg, good flexibility and good compatibility with the adhesive matrix, thereby preparing an adhesive composition with uniform mixing and excellent initial adhesion, impact resistance and peeling force. The glass transition temperature (Tg) refers to the temperature corresponding to the transition of an amorphous polymer from a glassy state to a highly elastic state. Tg is directly related to the flexibility of the molecular chain. The lower the Tg, the greater the flexibility of the molecular chain of the substance, which correspondingly indicates that the spreadability of the oligomeric acid of the present invention is better. The glass transition temperature (Tg) of the unsaturated carboxylic acid or its oligomeric acid of the present invention is less than or equal to -40°C, preferably less than or equal to -45°C, more preferably less than or equal to -50°C, further preferably less than or equal to -70°C, and particularly preferably less than or equal to -80°C.

[0025] The carboxylic acid tackifier according to the present invention is more preferably an unsaturated carboxylic acid having one or more double bonds, for example, an unsaturated carboxylic acid containing 1, 2, 3, 4 or 5 double bonds.

[0026] The carboxylic acid tackifier according to the present invention is preferably C 10 ~C 25 At least one of unsaturated carboxylic acids or oligomeric acids thereof, more preferably C 15 ~C 20 At least one of unsaturated carboxylic acids or oligomeric acids thereof, even more preferably C 16 ~C 18 At least one of an unsaturated carboxylic acid or an oligomeric acid thereof.

[0027] The carboxylic acid tackifier according to the present invention is preferably C 10 ~C 25 The oligomeric acid of unsaturated carboxylic acid has a degree of polymerization of 1 to 20, preferably 1 to 10, more preferably 1 to 6, even more preferably 2 to 6, most preferably 2 to 4, for example, the degree of polymerization of the oligomeric acid is 2 or 3.

[0028] The carboxylic acid thickener according to the present invention is preferably one of oleic acid, linoleic acid, linolenic acid, dimer acid, trimer acid or tetramer acid of oleic acid, linoleic acid or linolenic acid; or preferably a mixture of two or more of the aforementioned carboxylic acids or oligomer acids. Commercially available dimer acids are usually composed of unsaturated C 18 Fatty acids polymerize to form C 36 Commercially available trimer acids are oleic acid, linoleic acid, etc. 18 Unsaturated fatty acids are polymerized to form C 54 of tricarboxylic acids.

[0029] The carboxylic acid thickener according to the present invention is preferably of plant origin, for example, unsaturated fatty acids containing 18 carbon atoms such as oleic acid, linoleic acid, and linolenic acid extracted from soybean and cottonseed.

[0030] In the pressure-sensitive adhesive composition according to the present invention, based on the weight of the adhesive matrix, the content of the liquid tackifier is preferably 1 to 45 wt %, even preferably 2 to 40 wt %, more preferably 3 to 35 wt %, even more preferably 3 to 30 wt %, further more preferably 3 to 25 wt %, for example, 3.5 wt %, 4 wt %, 4.5 wt %, 5 wt %, 5.5 wt %, 6 wt %, 6.5 wt %, 7 wt %, 7.5 wt %, 8 wt %, 8.5 wt %, 9 wt %, 9.5 wt %, 10 wt %, 12 wt %, 14 wt %, 16 wt % or 18 wt %.

[0031] In the pressure-sensitive adhesive composition according to the present invention, based on the weight of the adhesive matrix, the content of the carboxylic acid tackifier is preferably 1 to 30 wt %, even preferably 1 to 25 wt %, further preferably 1.5 to 24 %, more preferably 1.8 to 22 %, even more preferably 2 to 20 %, further more preferably 3 to 18 %, for example, 3.5 wt %, 4 wt %, 4.5 wt %, 5 wt %, 5.5 wt %, 6 wt %, 6.5 wt %, 7 wt %, 7.5 wt %, 8 wt %, 8.5 wt %, 9 wt %, 9.5 wt %, 10 wt %, 12 wt %, 14 wt % or 16 wt %.

[0032] In the pressure-sensitive adhesive composition according to the present invention, the liquid tackifier further includes other liquid tackifiers, and the other liquid tackifiers include one or more of liquid hydrocarbon tackifiers, terpene tackifiers and rosin tackifiers. Based on the weight of the adhesive matrix, the content of the other liquid tackifiers is preferably 0 to 40% by weight, more preferably 0 to 30% by weight, and more preferably 0 to 25% by weight. From the perspective of improving the initial adhesion and impact resistance of the pressure-sensitive adhesive composition to a greater extent, the content of the other liquid tackifiers is preferably 10% by weight or less, more preferably 5% by weight or less, and even more preferably 3% by weight or less, for example, 2% by weight or less, 1% by weight or less, 0% by weight (i.e., not containing other liquid tackifiers).

[0033] In the pressure-sensitive adhesive composition according to the present invention, the adhesive matrix may be an adhesive matrix commonly used in pressure-sensitive adhesives, such as an acrylic adhesive, an epoxy adhesive, or a silicone adhesive. Preferably, the adhesive matrix is ​​an acrylic adhesive.

[0034] According to another aspect of the present invention, the present invention also provides a method for preparing the above-mentioned pressure-sensitive adhesive composition, comprising: adding a carboxylic acid tackifier and a cross-linking agent to an adhesive matrix; and stirring and mixing uniformly to obtain the pressure-sensitive adhesive composition. In the preparation method according to the present invention, the carboxylic acid tackifier used has a low glass transition temperature Tg, good flexibility and good compatibility with the adhesive matrix, and a uniformly mixed adhesive composition can be easily prepared, and a uniformly mixed adhesive composition can be obtained by simply stirring and mixing. Therefore, the adhesive composition of the present invention has excellent initial adhesion, impact resistance and peeling force.

[0035] According to another aspect of the present invention, the present invention also provides a pressure-sensitive adhesive sheet, comprising the above-mentioned pressure-sensitive adhesive composition and optionally an adhesive substrate. The pressure-sensitive adhesive sheet can be prepared by coating the above-mentioned pressure-sensitive adhesive composition on a carrier such as PET, SUS, PE, etc.

[0036] According to another aspect of the present invention, the present invention also provides a method for preparing a pressure-sensitive adhesive sheet, comprising: coating the above-mentioned pressure-sensitive adhesive composition on a substrate to form a coating layer; and attaching another substrate to the coating layer and applying pressure, then removing the substrates on both sides of the coating layer to obtain a double-sided substrate-free bonding sheet, or removing any of the substrates on both sides of the coating layer or not removing any substrate to obtain a bonding sheet containing a substrate. Since the liquid carboxylic acid tackifier of the present invention has a low glass transition temperature Tg, good flexibility and good compatibility with the adhesive matrix, the adhesive composition of the present invention has good spreadability and can be easily prepared to obtain a pressure-sensitive adhesive sheet.

[0037] According to another aspect of the present invention, the present invention also provides a use of a carboxylic acid as a tackifier in a pressure-sensitive adhesive composition, wherein the carboxylic acid is selected from C 10 ~C 25 Unsaturated carboxylic acid and C 10 ~C 25 At least one of the oligomeric acids of unsaturated carboxylic acids.

[0038] The adhesive composition and adhesive sheet of the present invention and their preparation method can produce the following beneficial technical effects, namely: the present invention adds unsaturated carboxylic acid or its oligomeric acid as a tackifier to the pressure-sensitive adhesive composition for the first time, and the carboxylic acid tackifier is basically not involved in or does not participate in the polymerization reaction of the adhesive; because the carboxylic acid tackifier has a lower glass transition temperature Tg, good flexibility and good compatibility with the pressure-sensitive adhesive, the initial adhesion performance, impact resistance and bonding performance to low-polarity plates of the adhesive composition of the present invention are significantly improved. Thus, the present invention solves the problems of poor initial adhesion performance, poor impact resistance and poor bonding to low-polarity substrates of the adhesive when conventional liquid resins are used as tackifiers. Moreover, the oligomeric acid of the present invention can be an organic acid of plant origin, so the adhesive composition of the present invention is an environmentally friendly adhesive material.

[0039] Example

[0040] The embodiments of the present invention use the following test methods to test initial adhesion performance, impact resistance performance and peeling force performance.

[0041] 1. Test Method

[0042] (1) Initial adhesion performance test

[0043] The measurement of initial adhesion properties for very short contact time is the rolling ball initial adhesion test. The adhesive composition (coating amount of 50 g / m2) is applied on one side of a standard polyester carrier with a thickness of 23 μm. 2 ) to form a sample to be tested. A strip test sample of about 10 cm long is fixed horizontally on a test bench with the adhesive side facing up. A steel ball (diameter: 11 mm; mass: 5.6 g) is cleaned with acetone and conditioned for 2 hours under standard conditions (temperature: 23°C + / -1°C; relative humidity: 50% + / -1%). When measuring, the steel ball is accelerated by rolling down a slope of 65 mm high (angle of inclination: 21°) by the action of the earth's gravity, so that the steel ball rolls directly from the slope to the adhesive surface of the sample. Measure the distance traveled from the steel ball to the adhesive surface to stop on the adhesive surface. The rolling distance of the steel ball thus measured is used as the initial adhesion performance of the adhesive composition. The shorter the measured distance, the higher the initial adhesion or initial adhesion performance, and vice versa. The test results of each sample are obtained by the average value of the rolling distance of the steel ball measured five times separately (in millimeters (mm)).

[0044] (2) Peel force test

[0045] The present invention tests the 180° peeling force performance of the adhesive composition on different substrates, namely, stainless steel (SUS), polyethylene (PE) and polycarbonate (PC) substrates.

[0046] The peeling force of the present invention is measured under the conditions of 23°C ± 1°C temperature and 50% ± 5% relative humidity. The sample is cut into a width of 20 mm and adhered to a SUS substrate, a PE substrate and a PC substrate respectively. The substrate is cleaned and conditioned before measurement. Then, the side facing away from the test substrate is lined with a plastic film such as PET, PVC or other thickness of 25 μm to prevent the stretching or deformation of the adhesive layer of the test sample during the test. The test sample is then rolled onto the substrate in the following manner: a 4kg roller is rolled back and forth on the tape at a rolling rate of 10m / min for 5 times. Immediately after the rolling treatment, a steel plate is inserted to allow the test sample to be tested for peeling force at an angle of 180°. The peeling force is measured using a Zwick tensile tester at a speed of 300mm / min. The test results of each sample are represented by the average value (N / cm) of the three measurement results.

[0047] (3) DuPont impact resistance test

[0048] At a temperature of 23±1°C and a humidity of 50±5%, the pressure-sensitive adhesive composition was laser cut into a U-shaped sample with an inner side length of 29mm×29mm and an outer side length of 33mm×33mm. Wipe the 45mm×45mm frame and 35mm×35mm lens made of PC material with alcohol and let it stand for 2 hours. The U-shaped adhesive sheet to be tested was attached between the frame and the lens, and a pressure of 248N was applied and kept for 5 seconds. After standing for 24 hours, an impact test was performed with a 150g impact head. The separation of the lens and the frame was considered failure. A 150g impact head was used to impact the test sample from a height of 5cm. If the sample does not fail, it is raised by another 5cm, that is, a height of 10cm, and free-fall impacted; if the sample still does not fail, it is raised by another 5cm, that is, a height of 15cm, and free-fall impacted, and so on. Record the height at which the sample fails. Calculate the DuPont impact resistance W=mgh (m is 150g, g is the acceleration of gravity 9.8m / s 2 , h is the final failure height of the sample).

[0049] 2. Raw materials and their abbreviations

[0050] The raw materials and their abbreviations used in the examples of the present invention are shown in Table 1 below.

[0051] Table 1. Raw materials and their abbreviations used in the examples of the present invention

[0052]

[0053]

[0054] (1) Preparation of (meth)acrylic glue A

[0055] The preparation steps of (meth) acrylic glue A include:

[0056] In a reaction vessel equipped with a condenser, a nitrogen inlet pipe, a thermometer and a stirring device, the monomer components in the proportions shown in Table 2 were added. 0.20 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator and toluene as a polymerization reaction solvent so that the monomer components are 70% by weight were added. Nitrogen was circulated and nitrogen replacement was performed for about 1 hour while stirring. Then, the reaction vessel was heated to 65°C and the reaction was carried out for 6 hours. Thereafter, the reaction vessel was heated to 80°C and the reaction was carried out for 3 hours to prepare a weight average molecular weight (M w ) is 670,000 (meth)acrylic polymer A.

[0057] (2) Preparation of (meth) acrylic glue B1 modified with tackifying resin

[0058] The preparation steps of the (meth)acrylic acid polymer b1 include:

[0059] In a reaction vessel equipped with a condenser, a nitrogen inlet pipe, a thermometer and a stirring device, the monomer components in the proportions shown in Table 2 were added. 0.18 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator and toluene as a polymerization reaction solvent so that the monomer component is 70% by weight were added. Nitrogen was circulated and nitrogen replacement was performed for about 1 hour while stirring. Then, the reaction vessel was heated to 63°C and reacted for 7 hours. Thereafter, the reaction vessel was heated to 80°C and reacted for 3 hours to prepare a weight average molecular weight (M w ) is 850,000 (meth)acrylic polymer b1.

[0060] The preparation steps of the tackifying resin modified (meth) acrylic glue B1 include:

[0061] To the synthesized (meth)acrylic polymer b1, 0.42 parts by weight of terpene phenol resin (trade name H150, softening point 150°C, manufactured by DRT Industries) was added relative to 100 parts by weight of the dry mass of the (meth)acrylic polymer to prepare a tackifier resin-modified (meth)acrylic glue B1.

[0062] (3) Preparation of (meth) acrylic glue B2 modified with tackifying resin

[0063] The preparation steps of (meth)acrylic acid polymer b2 include:

[0064] A mixture of monomer components shown in Table 1 was placed in a reaction vessel equipped with a condenser, a nitrogen inlet pipe, a thermometer and a stirring device. 0.18 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator and toluene as a polymerization reaction solvent were added so that the monomer component was 70% by weight. Nitrogen was circulated and nitrogen replacement was performed for about 1 hour while stirring. Then, the reaction vessel was heated to 59°C and reacted for 8 hours. Thereafter, the reaction vessel was heated to 80°C and reacted for 3 hours to prepare a weight average molecular weight (M w ) is 1 million and is b2.

[0065] The preparation steps of the tackifying resin-modified (meth) acrylic glue B2 include:

[0066] To the synthesized (meth)acrylic polymer b2, 0.42 parts by weight of rosin resin (trade name D135, softening point 135°C, manufactured by Arakawa Industries, Ltd.) was added relative to 100 parts by weight of the dry mass of the (meth)acrylic polymer to prepare a tackifying resin-modified (meth)acrylic glue B2.

[0067] Table 2. Monomer composition of (meth)acrylic acid (mass percentage %)

[0068]

[0069] 3. Examples 1-30 and Comparative Examples 1-11

[0070] Embodiments 1 to 5

[0071] Weigh 100 parts by weight of (meth)acrylate polymer A, and add different contents (mass percentage relative to polymer A) of monocarboxylic acid (trade name HY-90, manufactured by Anhui Hongtai New Materials Co., Ltd.) as shown in Table 3. Add 0.06 parts by weight of epoxy crosslinking agent (trade name GA-240, manufactured by Huntsman Chemical Company). Stir thoroughly for 30 minutes after mixing. The above-mentioned adhesive composition solution is coated on a polyethylene terephthalate (PET) separator (trade name 20459, manufactured by Mitsubishi Chemical Corporation) with a final thickness (thickness of the adhesive layer) of 50 μm to form a coating layer (adhesive composition layer). Then, dry it in a dryer at 120°C for 5 minutes to volatilize the solvent and the very small amount of residual monomers. Thus, a PET separator is set on the above-mentioned coating layer to prepare a substrate-free double-sided adhesive sheet of a separator comprising an adhesive layer and a protective adhesive layer on both sides.

[0072] Embodiments 6 to 10

[0073] 100 parts by weight of (meth)acrylate polymer A was weighed, and different amounts of dimer acid (trade name HY-13, manufactured by Anhui Hongtai New Materials Co., Ltd.) were added as shown in Table 3. The subsequent steps were the same as those of Examples 1-5.

[0074] Examples 11 to 15

[0075] 100 parts by weight of (meth)acrylate polymer A was weighed, and different amounts of dimer acid (trade name: Pripol 1006, manufactured by Croda Corporation) were added as shown in Table 3. The subsequent steps were the same as those of Examples 1 to 5.

[0076] Embodiments 16 to 20

[0077] 100 parts by weight of (meth)acrylate polymer A was weighed, and different amounts of trimer acid (trade name TMA-3085, manufactured by Shanghai Zhipu Chemical Co., Ltd.) were added as shown in Table 3. The subsequent steps were the same as those of Examples 1-5.

[0078] Examples 21 to 26

[0079] 100 parts by weight of the tackifying resin modified (meth)acrylate glue B1 was weighed, and different contents of the above monocarboxylic acid, dimer acid and trimer acid were added as shown in Table 3. The subsequent steps were the same as the preparation steps of Examples 1-5.

[0080] Examples 27 to 30

[0081] 100 parts by weight of the tackifying resin modified (meth)acrylate polymer B2 was weighed, and different contents of dimer acid were added as shown in Table 3. The subsequent steps were the same as the preparation steps of Examples 1-5.

[0082] Comparative Example 1

[0083] 100 parts by weight of (meth)acrylate polymer A was weighed without adding carboxylic acid thickener. The subsequent steps were the same as those of Examples 1 to 5.

[0084] Comparative Example 2

[0085] 100 parts by weight of the tackifier resin-modified (meth)acrylic polymer B1 was weighed without adding a carboxylic acid tackifier. The subsequent steps were the same as those of Examples 1 to 5.

[0086] Comparative Example 3

[0087] 100 parts by weight of the tackifier resin-modified (meth)acrylic polymer B2 was weighed without adding a carboxylic acid tackifier. The subsequent steps were the same as those of Examples 1 to 5.

[0088] Comparative Examples 4 to 8

[0089] 100 parts by weight of (meth)acrylate polymer A was weighed, and conventional liquid hydrocarbon resin (Wintack 10, manufactured by Total Energy) with different percentage contents as shown in Table 3. The subsequent steps were the same as those of Examples 1-5.

[0090] Comparative Examples 9-10

[0091] 100 parts by weight of the tackifying resin modified (meth) acrylic polymer B1 was weighed, and conventional liquid hydrocarbon resin (Wintack 10, manufactured by Total Energy) with different percentage contents as shown in Table 3. The subsequent steps were the same as those of Examples 1-5.

[0092] Comparative Examples 11-12

[0093] 100 parts by weight of the tackifying resin modified (meth) acrylic polymer B2 was weighed, and conventional liquid hydrocarbon resin (Wintack 10, manufactured by Total Energy) with different percentage contents as shown in Table 3. The subsequent steps were the same as those of Examples 1-5.

[0094] 4. Impact on initial adhesion performance

[0095] The initial adhesion properties of the pressure-sensitive adhesive compositions prepared in Examples 1-30 and Comparative Examples 1-12 were measured using the rolling ball initial adhesion performance test method. The measurement results are shown in Table 3 below.

[0096] Table 3. Effect of monocarboxylic acid or oligomeric acid on initial adhesion properties of adhesive composition

[0097]

[0098]

[0099] The initial tack performance test results in Table 3 above show that: adding monocarboxylic acid HY-90 or oligomeric acid HY-13, Pripol1006 and TMA-3085 as tackifiers to the adhesive composition can significantly improve the initial tack performance of the pressure-sensitive adhesive composition; and compared with other commonly used liquid tackifying resins, the monocarboxylic acid or oligomeric acid added as a tackifier in the present invention is more significant in improving the initial tack performance of the adhesive composition. In addition, the initial tack performance test results in Table 3 above also show that: for the pressure-sensitive adhesive (such as B1 and B2) modified with tackifying resins, the addition of monocarboxylic acid HY-90 and oligomeric acid HY-13, Pripol1006 and TMA-3085 also improves the initial tack performance of the modified pressure-sensitive adhesive; and compared with the improvement effect of the initial tack performance of the pressure-sensitive adhesive by the above monocarboxylic acid or oligomeric acid, other common liquid tackifying resins cannot improve the initial tack performance of the pressure-sensitive adhesive or its initial tack performance does not meet the use requirements.

[0100] 5. Impact on peeling force

[0101] The peeling force (i.e., bonding performance) of the pressure-sensitive adhesive compositions prepared in some of the above examples and comparative examples on substrates with different polarities was tested. The specific test results are shown in Table 4 below.

[0102] Table 4. Effect of monocarboxylic acid or oligomeric acid on the peeling force of substrates with different polarity

[0103]

[0104] Note: zip means that the adhesive has poor wettability and the adhesive is sticky and slippery when peeled off from the bonding substrate.

[0105] The peeling force test results in Table 4 above show that when oligomeric acid HY-13 and Pripol 1006 are added to the pressure-sensitive adhesive composition as tackifiers, the peeling force (or bonding performance) of the pressure-sensitive adhesive composition on the surface of low-polarity substrates PE and PC is significantly improved; while when other liquid tackifying resins Wintack 10 and Y308 are used, the pressure-sensitive adhesive composition has poor wettability to low-polarity substrates PE and PC, and the bonding fails. When the adhesive is peeled off from the low-polarity substrate, a stick-slip (stuck) phenomenon (zip) occurs, causing the measured values ​​to jump back and forth, and the peeling force cannot be accurately measured. Therefore, adding a carboxylic acid tackifier to the pressure-sensitive adhesive composition can significantly improve the bonding performance of the adhesive to the low-polarity substrate, while other common liquid tackifiers cannot improve the bonding performance or the bonding fails.

[0106] 6. Impact on impact resistance

[0107] The DuPont impact resistance test method was used to test the impact resistance of the pressure-sensitive adhesive compositions prepared in some of the above examples and comparative examples. The specific test results are shown in Table 5 below.

[0108] Table 5. Effect of carboxylic acid tackifier on impact resistance

[0109]

[0110] The impact resistance test results in Table 5 above show that the addition of oligomeric acid HY-13 and Pripol 1006 significantly improves the impact resistance of the pressure-sensitive adhesive; and compared with other liquid resins Wintack 10, oligomeric acid HY-13 and Pripol 1006 have a greater improvement in impact resistance. In addition, the impact resistance test results in Table 5 above show that for pressure-sensitive adhesives (B1, B2) that have been modified with other resins, the addition of oligomeric acid HY-13 and Pripol 1006 can also improve the impact resistance of the pressure-sensitive adhesive. Therefore, compared with common liquid tackifying resins, adding oligomeric acids to adhesives can more significantly improve the impact resistance of adhesives.

[0111] The technical solution of the present invention is not limited to the above-mentioned specific implementation or embodiment. The above-mentioned specific implementation or embodiment is only illustrative and not restrictive. Under the guidance of the specific implementation or embodiment described in the present invention, those skilled in the art can make many improvements and variations without departing from the scope of protection of the present invention and the claims, and these improvements and variations all fall within the protection of the present invention.

Claims

1. A pressure-sensitive adhesive composition comprising an adhesive matrix, a liquid tackifier and a crosslinking agent, in, The liquid tackifier comprises a carboxylic acid tackifier, wherein the carboxylic acid tackifier is selected from C 10 ~C 25 Unsaturated carboxylic acid and C 10 ~C 25 At least one of the oligomeric acids of unsaturated carboxylic acids.

2. The pressure-sensitive adhesive composition according to claim 1, characterized in that The carboxylic acid tackifier is selected from C 15 ~C 20 Unsaturated carboxylic acid and C 15 ~C 20 At least one of the oligomeric acids of unsaturated carboxylic acids; preferably selected from C 16 ~C 18 Unsaturated carboxylic acid and C 16 ~C 18 At least one of the oligomeric acids of unsaturated carboxylic acids.

3. The pressure-sensitive adhesive composition according to claim 1 or 2, characterized in that: The carboxylic acid tackifier is selected from the oligomeric acid, and the degree of polymerization of the oligomeric acid is 1 to 10, preferably 1-6, even more preferably 2-6, and more preferably 2-4.

4. The pressure-sensitive adhesive composition according to any one of claims 1 to 3, characterized in that: The liquid tackifier also includes one or more of a liquid hydrocarbon tackifier, a terpene tackifier resin and a rosin tackifier resin.

5. The pressure-sensitive adhesive composition according to any one of claims 1 to 4, characterized in that: The content of the liquid tackifier is 1 to 45% based on the weight of the adhesive matrix.

6. The pressure-sensitive adhesive composition according to any one of claims 1 to 5, characterized in that: Based on the weight of the adhesive matrix, the content of the carboxylic acid tackifier is 1 to 25%, preferably 2 to 25%, even more preferably 2 to 20%, and more preferably 3 to 15%.

7. The pressure-sensitive adhesive composition according to any one of claims 1 to 6, characterized in that: The carboxylic acid viscosity enhancer is selected from oleic acid, linoleic acid, linolenic acid, dimer acid or trimer acid of oleic acid, linoleic acid, linolenic acid, and a mixture of two or more thereof.

8. The pressure-sensitive adhesive composition according to any one of claims 1 to 7, characterized in that: The adhesive matrix is ​​an acrylic adhesive.

9. A method for preparing the pressure-sensitive adhesive composition according to any one of claims 1 to 8, comprising: adding a carboxylic acid tackifier and a cross-linking agent to the adhesive matrix; as well as The mixture is stirred and mixed uniformly to obtain the pressure-sensitive adhesive composition.

10. A pressure-sensitive adhesive sheet, comprising the pressure-sensitive adhesive composition according to any one of claims 1 to 8 and optionally an adhesive substrate.

11. A method for preparing a pressure-sensitive adhesive sheet, comprising: Applying the pressure-sensitive adhesive composition according to any one of claims 1 to 8 on a substrate to form a coating layer; as well as Another substrate is attached to the coating layer and pressure is applied, and then the substrates on both sides of the coating layer are removed to obtain a double-sided substrate-free bonding sheet, or any substrate on both sides of the coating layer is removed or no substrate is removed to obtain a substrate-containing bonding sheet.

12. Use of a carboxylic acid as a tackifier in a pressure-sensitive adhesive composition, wherein: The carboxylic acid is selected from C 10 ~C 25 Unsaturated carboxylic acid and C 10 ~C 25 At least one of the oligomeric acids of unsaturated carboxylic acids.

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