KR20190081304A - Heat resistant rubber adhesive composition and adhesive tape containing the same - Google Patents

Abstract

The present invention relates to a heat-resistant rubber adhesive composition and a heat-resistant adhesive tape comprising the same. According to the present invention, the heat-resistant rubber adhesive composition comprises: natural or synthetic rubber; a tackified resin; a polyfunctional thiol compound; an initiator; and a reaction accelerator and the heat-resistant tape having excellent heat resistance comprises the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a heat-resistant rubber adhesive composition and a heat-resistant adhesive tape containing the heat-

TECHNICAL FIELD The present invention relates to a heat-resistant rubber-based pressure-sensitive adhesive composition and a heat-resistant pressure-sensitive adhesive tape comprising the same. More specifically, the present invention relates to a pressure-sensitive adhesive composition having heat resistance, which retains adhesiveness even at high temperatures by adding a specific crosslinking agent to the pressure- And a heat-resistant adhesive tape comprising the same.

The adhesive tape is formed by coating a substrate with an adhesive. BACKGROUND ART [0002] Adhesive tapes used in semiconductors and automobile manufacturing processes are used in high-temperature environments, and therefore heat resistance, adhesive properties and adhesive strength of adhesive layers are required.

On the other hand, the adhesive tape is removed at the end of the product process, and when the adhesive layer is transferred to the bonded component, the stability of the process and the reliability of the product are greatly threatened.

However, if a high adhesive force is required in a series of processes, if the adhesive force is increased by adjustment of the composition, the transfer of the adhesive layer occurs inversely.

To solve this problem, a method of reducing the tape transfer by increasing the cohesive force of the adhesive layer is used. However, if the cohesive force of the adhesive layer is increased, there is a problem that the adhesive force is decreased.

Korean Patent Publication No. 10-2005-0117243 (December 14, 2005) Korean Patent Publication No. 10-2016-0085215 (July 15, 2016)

Therefore, it is an object of the present invention to provide a heat-resistant rubber-based pressure-sensitive adhesive composition which is excellent in adhesion even when used in a high-temperature environment and does not leave a residue on the adherend surface during removal.

Another object of the present invention is to provide a heat-resistant tape comprising the heat-resistant rubber-based pressure-sensitive adhesive composition.

According to the present invention, there is provided a heat-resistant rubber-based pressure-sensitive adhesive composition containing a natural rubber or a synthetic rubber, a tackifying resin, a polyfunctional thiol compound, an initiator and a reaction promoter.

The synthetic rubber comprises a double bond in the main chain, and is characterized by being SIS rubber or SBR rubber. The tackifier resin is a petroleum resin or a reactive phenol resin. Wherein the polyfunctional thiol compound has two thiol groups.

The thiol compound may be at least one selected from the group consisting of 1,3-propanedithiol, 1,4-butanedithiol, 1,4-benzenedimethanethiol, tetra (ethylene glycol) dithiol, hexa (ethylene glycol) Dithiol, 1,3,4-thiadiazole-2,5-dithiol, toluene-3,4-dithiol, benzene-1,2-dithiol, biphenyl- At least one selected from the group consisting of terphenyl-4,4-dithiol, 1,16-hexadecanediol, and the like.

In this case, it is preferable that 80 to 120 parts by weight of the tackifier resin, 1 to 10 parts by weight of the polyfunctional thiol compound, and 1 to 20 parts by weight of the reaction accelerator are contained per 100 parts by weight of the natural rubber or synthetic rubber. The heat-resistant rubber-based pressure-sensitive adhesive composition may further contain an inorganic substance, a stabilizer and a softening agent. At this time, the amount of the inorganic material used should not exceed 60% by weight in the total formulation.

According to another aspect of the present invention, there is provided a heat-resistant tape produced by coating the heat-resistant rubber-based pressure-sensitive adhesive composition on at least one surface of a substrate. Preferably, the substrate is cotton.

The heat-resistant tape produced by using the heat-resistant rubber-based pressure-sensitive adhesive composition according to the present invention has an advantage that the adhesive strength is maintained at a high temperature of 180 ° C for 30 minutes or more and a continuous process can be performed without leaving residue on the surface of the adherend even when removed .

Hereinafter, the present invention will be described more specifically.

According to the present invention, there is provided a heat-resistant rubber-based pressure-sensitive adhesive composition containing a natural rubber or a synthetic rubber, a tackifying resin, a polyfunctional thiol compound, an initiator and a reaction promoter.

The synthetic rubber includes a double bond in the main chain, and SIS rubber or SBR rubber may be used. It is preferable that the SIS rubber in the synthetic rubber to be used has a styrene content of 40 wt% or less and the SBR rubber has a styrene content of 30 wt% or less.

When natural rubber is used alone in combination with synthetic rubber, it is preferable since it is excellent in heat resistance and holding power under the same conditions. More preferably, the natural rubber 80 is used in a ratio of 20 to the synthetic rubber 20. In this case, the synthetic rubber may be a mixture of SIS rubber and optionally SEBS rubber.

As the tackifying resin, a petroleum resin or a reactive phenolic resin may be used, and preferably a reactive phenolic resin is used.

The multifunctional thiol compound used in the composition forms a bridge at the double bond moiety contained in the main chain of the rubber. Specifically, a radical is formed by using a peroxide or a persulfide in an unsaturated group of the main chain, and then the reaction is induced with a polyfunctional thiol compound, preferably a thiol compound having a bifunctional group, to improve the heat resistance.

The thiol compound may be at least one selected from the group consisting of 1,3-propanedithiol, 1,4-butanedithiol, 1,4-benzenedimethanethiol, tetra (ethylene glycol) dithiol, hexa (ethylene glycol) Dithiol, 1,3,4-thiadiazole-2,5-dithiol, toluene-3,4-dithiol, benzene-1,2-dithiol, biphenyl- Terphenyl-4,4-dithiol, 1,16-hexadecanediol, and the like can be used alone or in combination. Preferably, 1,3-propanedithiol, 1,4-benzenedimethanethiol, and 1,16-hexadecanedithiol are mainly used.

It is also possible to further include other polythiol compounds.

 A metal oxide may be used together to improve the heat resistance.

The heat-resistant rubber-based pressure-sensitive adhesive composition is prepared by blending 80 to 120 parts by weight of a tackifier resin, 10 parts by weight or less, preferably 1 to 10 parts by weight of a polyfunctional thiol compound, 20 parts by weight. The heat-resistant rubber-based pressure-sensitive adhesive composition may further contain an inorganic substance such as calcium carbonate, cray or zeolite, a stabilizer and a softening agent. And various kinds of physical properties of the pressure-sensitive adhesive are produced through proper mixing of inorganic materials. At this time, the amount of the inorganic material used should not exceed 60% by weight in the total formulation.

The reaction temperature in the production of the pressure-sensitive adhesive composition depends on the characteristics of the initiator. To generate radicals, azo-based compounds, peroxide, and persulfate-based materials can be used. AIBN (azobisisobutyronitrile) may be used as the azo compound. The melting point is 103 to 105 ° C, and radicals are generated at 60 ° C or higher. Di-tert-butyl peroxide (DTBP), benzoyl peroxide (BPO), aceton peroxide, and methyl ethyl ketone peroxide (MEKP) may be used as the peroxide compound. As persulfate compounds, ammonium persulfate (APS), potassium peroxydisulfate (KPS), etc. may be used.

The temperature at which the pressure-sensitive adhesive composition of the present invention is blended is preferably determined within the range of 110 to 150 ° C. If possible, it is considered appropriate to use an initiator having a melting point in this range. However, Other than the temperature range is also applicable.

The reactive phenolic resin attacks the double bonds in the main chain of the rubber when a suitable temperature and accelerator are added to cause a crosslinking reaction. The advantage of such a crosslinking system is that when a radical generated by the rubber backbone attack of the initiator is reacted with a polyfunctional thiol compound or the like to form crosslinking at a temperature of 110 to 120 ° C and the process proceeds to 130 ° C or higher, The phenolic resin participating in the reaction forms an additional crosslink.

The reaction promoter enhances the activity of the target substance so that the reaction can be stably performed at a lower temperature. In general, a metal oxide is used. In the present invention, zinc oxide (ZnO), magnesium oxide (MgO), cadmium oxide (CdO), or the like can be used as the metal oxide, and ZnO is preferably used.

In the present invention, azo-based, peroxide-based, and persulfate-based initiators are used, unlike the conventional art, and a crosslinking reaction is carried out by simultaneously using a polyfunctional thiol compound and a reactive phenolic resin. It is possible to adjust various physical properties according to the kind of rubber, whether or not a reactive phenolic resin is added, and the amount of the adhesive, so that it is possible to supply a pressure sensitive adhesive to meet a desired property of a consumer.

The heat-resistant pressure-sensitive adhesive composition thus prepared is coated on one side of a substrate to produce a heat-resistant tape. As the base material, various sheets in the form of fibers can be used, and preferably cotton balls are used. Cotton fabrics can be produced by using cotton fabrics, or by using rayon yarn, cotton-rayon blended yarn, or the like depending on the intended use and process characteristics.

According to one embodiment of the present invention, a coating layer composed of an acrylic polymer, a vinyl polymer, an acryl-vinyl copolymer resin, or the like having heat resistance is formed on the other surface of the base material on which the adhesive is not coated.

The heat-resistant tape thus produced exhibited excellent properties in that the adhesive strength was maintained for at least 30 minutes even at a high temperature of 180 ° C or higher, and no residue remained on the surface of the adherend even when removed.

[Example]

Hereinafter, the present invention will be described in more detail with reference to examples and test examples.

Examples 1 to 16: Preparation of pressure-sensitive adhesive composition

The pressure-sensitive adhesive compositions were prepared according to the compositions shown in Tables 1 to 16 below. As the mercaptan compound, 1,3-propanethiol, 1,4-benzenedimethanethiol and 1,16-hexadecanediol having two functional groups were used singly or in combination, and the petroleum resin was C1100 (sp = 100 ° C , C5 system) and A1100 (sp = 100 deg. C, C5 system) were used. As reactive phenolic resin, SP 1045 (product of SI, containing 9 ~ 10% of methylol) was used.

division Input (g) Characteristic Natural rubber 50 Tg = -65 ° C Petroleum resin 50 Sp = 100 DEG C Mercaptan compound One  Dithiol Calcium carbonate 100 wonderment ZnO 0.5 Initiator 0.1 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Natural rubber 50 Tg = -65 ° C Petroleum resin 50 Sp = 100 DEG C Mercaptan compound 5 Dithiol Calcium carbonate 100 wonderment ZnO 2.5 Initiator 0.5 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Natural rubber 50 Tg = -65 ° C Petroleum resin 50 Sp = 100 DEG C Mercaptan compound 3 Dithiol Calcium carbonate 100 wonderment ZnO 1.5 Initiator 0.3 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Synthetic rubber 50 SIS, KRATON 411N Petroleum resin 50 Sp = 100 DEG C Mercaptan compound One Dithiol Calcium carbonate 100 wonderment ZnO 0.5 Initiator 0.1 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Synthetic rubber 50 SIS, KRATON 411N Petroleum resin 50 Sp = 100 DEG C Mercaptan compound 3 Dithiol Calcium carbonate 100 wonderment ZnO 1.5 Initiator 0.3 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Synthetic rubber 50 SIS, KRATON 411N Petroleum resin 50 Sp = 100 DEG C Mercaptan compound 5 Dithiol Calcium carbonate 100 wonderment ZnO 2.5 Initiator 0.5 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Natural rubber 50 Tg = -65 ° C Petroleum resin / reactive phenolic resin 49/1 Sp = 100 ℃ / SI Company Products Mercaptan compound One Dithiol Calcium carbonate 100 wonderment ZnO 0.5 Initiator 0.1 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Natural rubber 50 Tg = -65 ° C Petroleum resin / reactive phenolic resin 47/3 Sp = 100 ℃ / SI Company Products Mercaptan compound 3 Dithiol Calcium carbonate 100 wonderment ZnO 1.5 Initiator 0.3 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Natural rubber 50 Tg = -65 ° C Petroleum resin / reactive phenolic resin 45/5 Sp = 100 ℃ / SI Company Products Mercaptan compound 5 Dithiol Calcium carbonate 100 wonderment ZnO 2.5 Initiator 0.5 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Synthetic rubber 50 SIS, KRATON 411N Petroleum resin / reactive phenolic resin 49/1 Sp = 100 ℃ / SI Company Products Mercaptan compound One Dithiol Calcium carbonate 100 wonderment ZnO 0.5 Initiator 0.1 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Synthetic rubber 50 SIS, KRATON 411N Petroleum resin / reactive phenolic resin 47/3 Sp = 100 ℃ / SI Company Products Mercaptan compound 3 Dithiol Calcium carbonate 100 wonderment ZnO 1.5 Initiator 0.3 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Synthetic rubber 50 SIS, KRATON 411N Petroleum resin / reactive phenolic resin 45/5 Sp = 100 ℃ / SI Company Products Mercaptan compound 5 Dithiol Calcium carbonate 100 wonderment ZnO 2.5 Initiator 0.5 KPS Softener, stabilizer, etc. 1.5 Process oil, UV stabilizer

division Input (g) Characteristic Natural rubber / synthetic rubber 40/10 Tg = -65 占 폚 / SIS Kraton 411N Petroleum resin 45 SP = 100 DEG C Calcium carbonate 100 wonderment Mercaptan compound 5 Dithiol Reactive phenolic resin 5 Methylol content 9 to 10% ZnO 10 accelerant KPS 0.5 Initiator

division Input (g) Characteristic Natural rubber / synthetic rubber 40/10 Tg = -65 占 폚 / SIS Kraton 411N Petroleum resin 45 SP = 100 DEG C Calcium carbonate 100 wonderment Mercaptan compound 2.5 Dithiol Reactive phenolic resin 5 Methylol content 9 to 10% ZnO 7.5 accelerant KPS 0.5 Initiator

division Input (g) Characteristic Natural rubber / synthetic rubber 40/10 Tg = -65 占 폚 / SIS Kraton 411N Petroleum resin 45 SP = 100 DEG C Calcium carbonate 100 wonderment Mercaptan compound 5 Dithiol Reactive phenolic resin 5 Methylol content 9 to 10% ZnO 7.5 accelerant KPS 0.5 Initiator

division Input (g) Characteristic Natural rubber / synthetic rubber 40/10 Tg = -65 占 폚 / SIS Kraton 411N Petroleum resin 45 SP = 100 DEG C Calcium carbonate 100 wonderment Mercaptan compound 5 Dithiol Reactive phenolic resin 5 Methylol content 9 to 10% ZnO 5 accelerant KPS 0.25 Initiator

Test Example 1: Evaluation of physical properties

The properties of the pressure-sensitive adhesive compositions prepared in Examples 1 to 16 were evaluated in the following manner.

Coat the pressure sensitive adhesive on the substrate (OPP, PET, etc.) to a certain thickness (25 ~ 50 micrometers on the dry basis) and dry thoroughly. The dried sample is used as a sample to measure heat resistance, adhesion, retention, and initial adhesion.

Heat resistance

The dried sample is made to have a width of 25 mm and a length of 100 mm or more, and then a length of 100 mm is attached to an SUS304 plate. Then, a constant weight is connected to the sample, and the time at which the tape is pushed away from the SUS plate while maintaining at 150 ° C is measured.

adhesiveness

A peeling angle of 180 占 (PSTC-1, JIS) was used.

retention

The dried sample is made to have a width of 25 mm and a length of 100 mm or more, and then attached to a SUS304 plate with a width of 25 mm and a length of 25 mm. Then, a constant weight is connected to the remaining sample, and the time at which the tape is pushed and dropped on the SUS plate is measured while the sample is maintained at 40 ° C.

Initial adhesion

The dried sample is made to have a length of about 150 mm and then fixed in the longitudinal direction at the lower end of the inclined plate having a 30 ° inclination. Roll the sus ball with a certain weight (7/16 inch) on a ramp with a 30 ° slope and measure the length of the sus ball in contact with the sample at the bottom of the slope. Measuring temperature 25 ℃.

The results are shown in Tables 17 and 18 below.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Heat resistance
(min, 150 DEG C) 15 70 20 15 20 70 95 125 adhesiveness
(N / cm, 25 DEG C) 9 8 9 9 9 8 8 7 retention
(hr, 40 DEG C) 10 15 17 17 10 15 20 25 Initial adhesion
(Cm, 25 DEG C) 5 7 5 5 5 7 7 9

division Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Heat resistance
(min, 150 DEG C) 130 80 100 135 135 115 135 135 adhesiveness
(N / cm, 25 DEG C) 6 9 8 5 5 6 5 5 retention
(hr, 40 DEG C) 25 15 20 25 25 23 27 27 Initial adhesion
(Cm, 25 DEG C) 11 5 8 15 15 13 15 15

As can be seen from the above tables, when used in combination with synthetic rubber rather than natural rubber alone, heat resistance and retention were excellent under the same conditions. At the same mixing ratio, the retention force was increased and the initial adhesive strength was decreased as the initiator content was increased.

The heat resistance and the holding power were improved compared with the case where the reactive phenol resin was not added. In addition, the heat resistance was improved by increasing the amount of reactive phenol resin, but the initial adhesion was decreased.

Since various physical properties can be adjusted depending on the type of rubber, whether or not the reactive phenolic resin is added, and the amount thereof, it is an important point of the present invention that a pressure-sensitive adhesive and a tape can be supplied according to the desired properties of the consumer.

Claims (15)

A heat-resistant rubber-based pressure-sensitive adhesive composition comprising a natural rubber or synthetic rubber, a tackifier resin, a polyfunctional thiol compound, an initiator, and a reaction promoter. The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 1, wherein the synthetic rubber comprises a double bond in the main chain and is SIS rubber or SBR rubber. The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 2, wherein the SIS rubber has a styrene content of 40 wt% or less and the SBR rubber has a styrene content of 30 wt% or less. The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 1, wherein 80 wt% of the natural rubber is mixed with 20 wt% of synthetic rubber. The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 1, wherein the tackifying resin is a petroleum resin or a reactive phenol resin. The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 1, wherein the polyfunctional thiol compound has two thiol groups. The process of claim 6, wherein the thiol compound is selected from the group consisting of 1,3-propanedithiol, 1,4-butanedithiol, 1,4-benzenedimethanethiol, tetra (ethylene glycol) dithiol, hexa (ethylene glycol) , Poly (ethylene glycol) dithiol, 1,3,4-thiadiazole-2,5-dithiol, toluene-3,4-dithiol, benzene- -Dithiol, para-terphenyl-4,4-dithiol, and 1,16-hexadecanedithiol. 2. The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 1, The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 6, wherein the thiol compound is 1,3-propanedithiol, 1,4-benzenedimethanethiol or 1,16-hexadecanedithiol. The rubber composition according to claim 1, which comprises 80 to 120 parts by weight of a tackifier resin, 1 to 10 parts by weight of a polyfunctional thiol compound, and 1 to 20 parts by weight of a reaction promoter, based on 100 parts by weight of the natural rubber or synthetic rubber Sensitive adhesive composition. The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 1, further comprising an inorganic substance, a stabilizer and a softening agent. The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 10, wherein the inorganic material is calcium carbonate, clay or zeolite, and does not exceed 60% by weight based on the total weight of the composition. The heat-resistant rubber-based pressure-sensitive adhesive composition according to claim 1, wherein the reaction promoter is zinc oxide (MgO), magnesium oxide (MgO), or cadmium oxide (CdO). A heat-resistant tape produced by applying the heat-resistant rubber-based pressure-sensitive adhesive composition of any one of claims 1 to 12 on at least one surface of a substrate. The heat-resistant tape according to claim 13, wherein the substrate is a cotton cloth. 14. The heat-resistant tape according to claim 13, wherein a heat-resistant rubber-based pressure-sensitive adhesive composition is applied to one surface of the substrate and a coating layer of an acrylic polymer, a vinyl-based polymer, and an acrylic-vinyl copolymer resin is formed on the other surface.