Acrylic resin for water-blocking film and preparation method thereof

Abstract

The invention relates to the technical field of polyester resin, in particular to acrylic resin for a water-blocking film and a preparation method of the acrylic resin. The acrylic resin is a (styrene-acrylonitrile)-b-(flexible acrylic acid-functional monomer)-c-(styrene-acrylonitrile-silane coupling agent) block polymer; the block polymer comprises the following components in parts by mass: 20-70 parts of a flexible acrylic monomer; 5 to 25 parts of acrylonitrile; 20 to 50 parts of styrene; 1-7 parts of a silane coupling agent; 2-10 parts of a functional monomer, wherein the functional monomer is used for carrying out a cross-linking reaction with the curing agent; the (styrene-acrylonitrile)-b-(flexible acrylic acid-functional monomer)-c-(styrene-acrylonitrile-silane coupling agent) triblock polymer prepared in the invention has good heat resistance and certain elasticity, is acrylic resin with good binding force with a water-blocking coating, and is used for a polymer protective layer.

Description

Technical Field

[0001] The invention relates to the technical field of polyester resins, in particular to an acrylic resin for a water-blocking film and a preparation method thereof. Background Art

[0002] At present, the water barrier problem of thin film materials has become a hot topic in the industry, and has been applied more and more widely, such as in quantum dot display screens, OLED display devices, photovoltaic water barrier backplanes, photovoltaic frontplanes, etc. The general practice is to use magnetron sputtering or evaporation to coat a layer of inorganic oxide on substrates such as PET to reduce the water vapor transmission rate, but after wet heat aging, the water vapor transmission rate generally increases rapidly. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an acrylic resin for a water-blocking film and a preparation method thereof.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0005] An acrylic resin for a water-blocking film, wherein the acrylic resin is a (styrene-acrylonitrile)-b-(flexible acrylic acid-functional monomer)-c-(styrene-acrylonitrile-silane coupling agent) block polymer.

[0006] Furthermore, the mass fractions of the components in the block polymer are as follows:

[0007] 20-70 parts of flexible acrylic monomer;

[0008] Acrylonitrile 5-25 parts;

[0009] Styrene 20-50 parts;

[0010] Silane coupling agent 1-7 parts;

[0011] 2-10 parts of functional monomers, wherein the functional monomers are used for cross-linking reaction with curing agents.

[0012] Furthermore, the flexible acrylic monomer includes one of methyl acrylate, ethyl acrylate, (n / iso) acrylate, (n / iso / tert) butyl acrylate, pentyl acrylate, cyclohexyl acrylate, and butyl methacrylate, and the homopolymer TG thereof is 8-55°C.

[0013] Furthermore, the silane coupling agent is a vinyl silane coupling agent, and the silane coupling agent is selected from KH570 or KH171.

[0014] Furthermore, the functional monomer is selected from one of acrylic acid, (meth)acrylic acid, and hydroxyalkyl (meth)acrylate.

[0015] Furthermore, the initiator is selected from azobisisobutyronitrile or benzoyl peroxide.

[0016] Furthermore, the B segment flexible acrylic monomer is preferably 40-70%.

[0017] Furthermore, the three sections ABC are 13-28: 41-73: 14-31.

[0018] A method for preparing an acrylic resin for a water-blocking film, the method comprising the following steps:

[0019] A certain amount of a mixture S1 of solvent ethyl acetate, styrene, acrylonitrile, and initiator azobisisobutyronitrile is polymerized at temperature T°C for T1 hour, a mixture S2 of solvent ethyl acetate, flexible acrylic monomer, acrylic acid, and initiator azobisisobutyronitrile is added and reacted for T2 hours, and finally a mixture S3 of solvent ethyl acetate, styrene, acrylonitrile, KH570, and initiator azobisisobutyronitrile is added and reacted for T1 hour.

[0020] Furthermore, the polymerization temperature of the mixture S1 is 75-85° C., the polymerization time T1 is 4-5 hours, and T2 is 4-5 hours.

[0021] Furthermore, in the preparation method, S1+S2+S3=200.3 parts, S3=S1+S KH570 , a total of 1 part of KH570, 3 parts of acrylic acid, X parts of acrylonitrile, 0.3 parts of azobisisobutyronitrile, and 100 parts of solvent ethyl acetate.

[0022] The beneficial effects of the technical solution of the present invention are:

[0023] The addition of flexible acrylic monomers in the present invention makes the resin elastic and can well eliminate thermal stress. Among them, butyl methacrylate (27°C), tert-butyl acrylate (55°C), cyclohexyl acrylate (16°C), and methyl acrylate (8°C) have better effects, and the homopolymer TG is preferably selected to be 8-55°C. At the same time, it can be seen from the comparative example that the method of ABC triblock polymer makes the polymer have higher tensile strength and elongation at break, can better release thermal stress during aging, and has lower water vapor transmission rate.

[0024] The (styrene-acrylonitrile)-b-(flexible acrylic acid-functional monomer)-c-(styrene-acrylonitrile-silane coupling agent) triblock polymer prepared in the present invention has good heat resistance and certain elasticity, and is an acrylic resin with good bonding force with a water-blocking coating, and is used for a polymer protective layer. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific implementation methods and description.

[0026] The acrylic resin used for the water-blocking film in the present invention is specifically a (styrene-acrylonitrile)-b-(flexible acrylic acid-functional monomer)-c-(styrene-acrylonitrile-silane coupling agent) block polymer.

[0027] Furthermore, the mass fractions of the components in the block polymer are as follows:

[0028] 20-70 parts of flexible acrylic monomer;

[0029] 5-25 parts of acrylonitrile, which plays a role in heat resistance;

[0030] 20-50 parts of styrene, styrene is used to improve toughness;

[0031] 1-7 parts of silane coupling agent, which combines with the metal oxide in the water-blocking coating to work;

[0032] 2-10 parts of a functional monomer, wherein the functional monomer is used for cross-linking reaction with a curing agent, and the functional monomer is selected from one of acrylic acid, (meth) acrylic acid, and hydroxyalkyl (meth) acrylate;

[0033] Initiator 0.1-0.4 parts.

[0034] Specifically, the flexible acrylic monomer includes one of methyl acrylate, ethyl acrylate, (n / iso) acrylate, (n / iso / tert) butyl acrylate, pentyl acrylate, cyclohexyl acrylate, and butyl methacrylate, and the homopolymer TG thereof is 8-55°C.

[0035] Specifically, the silane coupling agent is a vinyl silane coupling agent.

[0036] Specifically, the silane coupling agent is KH570 or KH171.

[0037] Specifically, the initiator is selected from one of azobisisobutyronitrile and benzoyl peroxide.

[0038] Specifically, the flexible acrylic monomer is preferably 40-70%, and the three segments ABC are 13-28:41-73:14-31 respectively.

[0039] The method for preparing the acrylic resin for the water-blocking film of the present invention comprises the following steps:

[0040] A certain amount of a mixture S1 of solvent ethyl acetate, styrene, acrylonitrile, and initiator azobisisobutyronitrile is polymerized at temperature T°C for T1 hour, a mixture S2 of solvent ethyl acetate, flexible acrylic monomer, acrylic acid, and initiator azobisisobutyronitrile is added and reacted for T2 hours, and finally a mixture S3 of solvent ethyl acetate, styrene, acrylonitrile, KH570, and initiator azobisisobutyronitrile is added and reacted for T1 hour.

[0041] Specifically, the polymerization temperature of the mixture S1 is 75-85° C., the polymerization time T1 is 4-5 hours, and T2 is 4-5 hours.

[0042] Specifically, in the preparation method, S1+S2+S3=200.3 parts, S3=S1+S KH570 , a total of 1 part of KH570, 3 parts of acrylic acid, X parts of acrylonitrile, 0.3 parts of azobisisobutyronitrile, and 100 parts of solvent ethyl acetate.

[0043] Specifically, the initiator is selected from one of azobisisobutyronitrile and benzoyl peroxide.

[0044] Embodiment 1:

[0045] A certain amount of a mixture S1 of ethyl acetate, styrene, acrylonitrile and azobisisobutyronitrile is polymerized at a temperature of T (°C) for T1 hour, a mixture S2 of ethyl acetate, a flexible acrylic monomer, acrylic acid and azobisisobutyronitrile is added and reacted for T2 hours, and finally a mixture S3 of ethyl acetate, styrene, acrylonitrile, KH570 and azobisisobutyronitrile is added and reacted for T1 hour. S1+S2+S3=200.3 parts, S3=S1+SKH570, wherein KH570 is 1 part, acrylic acid is 3 parts, acrylonitrile is X parts, azobisisobutyronitrile is 0.3 parts and ethyl acetate is 100 parts.

[0046] 100 parts of the obtained acrylic resin was mixed with 5 parts of commercially available Bayer L-75 curing agent, coated on the water-blocking coating with a dry thickness of 1 μm, and cured at 12°C for 10 minutes. The initial and double 85 aging water vapor transmission rates Z (g / m 2 .day) the initial water vapor transmission rate is 0.05 (g / m 2 .day), the water vapor transmission rate of the water-blocking film without a polymer protective layer after double 85 aging test was 0.46 (g / m 2 .day). The test method is: after aging at 85℃ and 85%RH for 500 hours, test the water vapor transmission rate at 38℃ and 90%RH.

[0047] In comparative example 1, the monomers and solvents ethyl acetate and azobisisobutyronitrile were added uniformly and reacted for 2T1+T2 hours to obtain acrylic resin. In comparative example 2, KH570 was added in the S1 stage, and in comparative example 3, KH570 was added in the S3 stage.

[0048] The specific amount of raw materials added and performance test are shown in Table 1

[0049]

[0050]

[0051]

[0052] Table 1

[0053] The test standard for tensile strength and elongation at break is GB / T 1040.3-2006.

[0054] As can be seen from Table 1, the addition of flexible acrylic monomers makes the resin elastic and can eliminate thermal stress well. Among them, butyl methacrylate (27°C), tert-butyl acrylate (55°C), cyclohexyl acrylate (16°C), and methyl acrylate (8°C) have better effects. It is appropriate to select homopolymer TG at 8-55°C. At the same time, it can be seen from the comparative example that the method of ABC triblock polymer makes the polymer have higher tensile strength and elongation at break, can better release thermal stress during aging, and has lower water vapor transmission rate. Comparison 2 and comparative example 3, due to the early addition of KH570, silane has more time to undergo cross-linking reaction in the presence of trace water, which reduces its elongation at break and slightly affects the water vapor transmission rate. From the perspective of reaction time and temperature, 75°C-85°C is appropriate, 9°C reacts violently, free radical disproportionation reaction increases, and resin elasticity decreases. 7°C reaction is not complete. In terms of time, 4-5 hours per section is appropriate. If the time is too short, the reaction is incomplete, and it is not a complete block polymerization. If the time is too long, the disproportionation reaction increases and the elasticity decreases slightly. Acrylonitrile has good heat resistance and can improve the effect of eliminating thermal stress of water-blocking coating, but excessive addition will make the resin brittle, so 10-20 parts is appropriate. 40-70% of flexible acrylic monomer is appropriate, and the three sections of ABC are 13-28:43-73:14-29 respectively.

[0055] Embodiment 2:

[0056] A certain amount of solvent ethyl acetate, styrene, acrylonitrile, initiator azobisisobutyronitrile mixture S1 is polymerized at T (℃) temperature for 4 hours, solvent ethyl acetate, flexible acrylic monomer, acrylic acid, hydroxyethyl acrylate: initiator azobisisobutyronitrile mixture S2 is added and reacted for 4 hours, and finally solvent ethyl acetate, styrene, acrylonitrile, silane coupling agent, initiator azobisisobutyronitrile mixture S3 is added and reacted for 4 hours to obtain acrylic resin. Among them, S1+S2+S3=200.3 parts, S2=S1+S 硅烷偶联剂 , total azobisisobutyronitrile: solvent ethyl acetate: butyl methacrylate: styrene: acrylonitrile: silane coupling agent: acrylic acid: hydroxyethyl acrylate = 0.3:100:(50-X1-X3):(40-X2):10:X1:X2:X3.

[0057] 100 parts of the obtained acrylic resin was mixed with 5 parts of commercially available Bayer L-75 curing agent, coated on the water-blocking coating with a dry thickness of 1 μm, and cured at 12°C for 10 minutes. The initial and double 85 aging water vapor transmission rates Z (g / m 2 .day), where the initial water vapor transmission rate is 0.05 (g / m 2 .day), the water vapor transmission rate of the water-blocking film without a polymer protective layer after double 85 aging test was 0.46 (g / m 2 .day). After aging at 85℃85%RH for 500 hours, the water vapor transmission rate was tested at 38℃, 90%RH.

[0058]

[0059] Table 2

[0060] From Table 2, we can see that KH570 can reduce the water vapor transmission rate after wet heat aging, because the silane coupling agent can combine with the water-blocking coating to prevent the water-blocking coating from cracking, and the silane coupling agent can consume part of the infiltrated water. However, when the silane coupling agent KH570 reaches 10 parts, it cannot be applied to the water-blocking coating, because during the polymerization process, the silicon oxygen bond of the silane coupling agent will cross-link in the presence of trace amounts of water. When KH570 has 10 parts, the acrylic resin cross-links into a jelly state and cannot be used further. At the same time, KH171 and KH151 also have the performance of reducing water vapor transmission rate, but because the chain is relatively short, they cannot better combine with the water-blocking coating, so the effect is slightly worse. Since isocyanate curing agent can undergo cross-linking reaction with carboxyl and hydroxyl groups, the molecular weight of the acrylic coating after the reaction is larger and can better protect the polymer coating. Therefore, both acrylic acid and hydroxyethyl acrylate can reduce the water vapor transmission rate and coordinate with each other to achieve better results. However, after adding 5 parts of each, the water vapor transmission rate increases. The reason is that excessive cross-linking makes the polymer protective layer hard and brittle, without elasticity, and its ability to eliminate thermal stress decreases.

[0061] It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary experimental examples, and that the present invention can be implemented in other specific forms without departing from the spirit and essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0062] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent claim scheme. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An acrylic resin for a water-blocking film, characterized in that: The acrylic resin is a (styrene-acrylonitrile)-b-(flexible acrylic acid-functional monomer)-c-(styrene-acrylonitrile-silane coupling agent) block polymer.

2. The acrylic resin for a water-blocking film according to claim 1, characterized in that: The mass fractions of each component in the block polymer are as follows: 20-70 parts of flexible acrylic monomer; Acrylonitrile 5-25 parts; Styrene 20-50 parts; Silane coupling agent 1-7 parts; 2-10 parts of functional monomers, wherein the functional monomers are used for cross-linking reaction with curing agents.

3. The acrylic resin for a water-blocking film according to claim 2, characterized in that: The flexible acrylic monomer includes one of methyl acrylate, ethyl acrylate, (n / iso) acrylate, (n / iso / tert) butyl acrylate, pentyl acrylate, cyclohexyl acrylate and butyl methacrylate, and the homopolymer TG thereof is 8-55°C.

4. The acrylic resin for a water-blocking film according to claim 2, characterized in that: The silane coupling agent is a vinyl silane coupling agent, and the silane coupling agent is selected from KH570 or KH171.

5. The acrylic resin for water-blocking film according to claim 4, characterized in that: The functional monomer is selected from one of acrylic acid, (meth)acrylic acid, and hydroxyalkyl (meth)acrylate.

6. The acrylic resin for water-blocking film according to claim 2, characterized in that: The flexible acrylic monomer is preferably 40-70%, and the three segments ABC are 13-28:43-73:14-29 respectively.

7. A method for preparing an acrylic resin for a water-blocking film, characterized in that: The preparation method comprises the following steps: A certain amount of a mixture S1 of solvent ethyl acetate, styrene, acrylonitrile, and initiator azobisisobutyronitrile is polymerized at temperature T°C for T1 hour, a mixture S2 of solvent ethyl acetate, flexible acrylic monomer, acrylic acid, and initiator azobisisobutyronitrile is added and reacted for T2 hours, and finally a mixture S3 of solvent ethyl acetate, styrene, acrylonitrile, KH570, and initiator azobisisobutyronitrile is added and reacted for T1 hour.

8. The method for preparing an acrylic resin for a water-blocking film according to claim 7, characterized in that: The polymerization temperature of the mixture S1 is 75-85° C., the polymerization time T1 is 4-5 hours, and T2 is 4-5 hours.

9. The method for preparing an acrylic resin for a water-blocking film according to claim 7, characterized in that: In the preparation method, S1+S2+S3=200.3 parts, S3=S1+S KH570 , a total of 1 part of KH570, 3 parts of acrylic acid, X parts of acrylonitrile, 0.3 parts of azobisisobutyronitrile, and 100 parts of solvent ethyl acetate.

10. The acrylic resin for water-blocking film according to claim 7, characterized in that: The initiator is selected from azobisisobutyronitrile or benzoyl peroxide.

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