阅读说明：本技术 一种扩散膜树脂溶液的制备方法及由其制得的扩散膜树脂溶液 (Preparation method of diffusion film resin solution and diffusion film resin solution prepared by same ) 是由 潘乐 陈明源 于 2019-11-14 设计创作，主要内容包括：本发明提供了一种扩散膜树脂溶液的制备方法及由其制得的扩散膜树脂溶液,所述制备方法包括以下步骤：1)将丙烯酸单体、部分引发剂和第一非苯类有机溶剂混合,得到第一滴加液；2)在惰性气体保护下,将第二非苯类有机溶剂升温,滴加步骤1)得到的第一滴加液,滴加完成后保温,得到反应液；3)将剩余部分的引发剂和第三非苯类有机溶剂混合,得到第二滴加液；4)向步骤2)得到的反应液中滴加步骤3)得到的第二滴加液,滴加完成后保温,得到所述扩散膜树脂溶液。本发明通过上述两步滴加过程得到了一种通用型扩散树脂溶液。另外,本发明所述制备方法均采用的是非苯类有机溶剂,整个反应过程更加绿色环保。(The invention provides a preparation method of a diffusion film resin solution and the diffusion film resin solution prepared by the preparation method, wherein the preparation method comprises the following steps: 1) mixing an acrylic monomer, a part of initiator and a first non-benzene organic solvent to obtain a first drop of liquid; 2) under the protection of inert gas, heating a second non-benzene organic solvent, dropwise adding the first added liquid obtained in the step 1), and preserving heat after dropwise adding is finished to obtain a reaction liquid; 3) mixing the rest part of the initiator with a third non-benzene organic solvent to obtain a second dropping liquid; 4) and (3) dropwise adding the second dropwise adding liquid obtained in the step 3) into the reaction liquid obtained in the step 2), and preserving heat after dropwise adding is completed to obtain the diffusion film resin solution. The general diffusion resin solution is obtained through the two-step dripping process. In addition, the preparation method provided by the invention adopts non-benzene organic solvents, so that the whole reaction process is more environment-friendly.)

1. A method for preparing a diffusion film resin solution, comprising the steps of:

1) mixing an acrylic monomer, a part of initiator and a first non-benzene organic solvent to obtain a first drop of liquid;

2) under the protection of inert gas, heating a second non-benzene organic solvent, dropwise adding the first added liquid obtained in the step 1), and preserving heat after dropwise adding is finished to obtain a reaction liquid;

3) mixing the rest part of the initiator with a third non-benzene organic solvent to obtain a second dropping liquid;

4) and (3) dropwise adding the second dropwise adding liquid obtained in the step 3) into the reaction liquid obtained in the step 2), and preserving heat after dropwise adding is completed to obtain the diffusion film resin solution.

2. The method of claim 1, wherein the acrylic monomer is selected from the group consisting of methyl methacrylate, butyl acrylate, methacrylic acid, acrylic acid, hydroxyethyl methacrylate, hydroxyethyl acrylate, cyclohexyl methacrylate, and ethyl acrylate.

3. The method according to claim 1 or 2, wherein the initiator is selected from any one of tert-butyl peroxybenzoate, azobisisobutyronitrile, tert-butyl peroxy2-ethylhexanoate and di-tert-butyl peroxide or a combination of at least two of them.

4. The production method according to any one of claims 1 to 3, wherein the acrylic monomer is added in an amount of 40 to 60%, preferably 45 to 50%, based on 100% by mass of the total mass of the diffusion film resin solution;

preferably, the initiator is added in an amount of 0.5 to 4%, preferably 1.5 to 2.5%, based on 100% by mass of the total diffusion film resin solution.

5. The production method according to any one of claims 1 to 4, wherein the second non-benzene organic solvent is added in an amount of 20 to 45%, preferably 35 to 40%, based on 100% by mass of the total diffusion film resin solution;

preferably, the mass ratio of the first non-benzene organic solvent to the third non-benzene organic solvent is (1.5-5):1, preferably (2-4): 1;

preferably, the second non-benzene organic solvent comprises a high-boiling point non-benzene solvent and a low-boiling point non-benzene solvent;

preferably, the high-boiling point non-benzene solvent is selected from any one of propylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate or dipropylene glycol methyl ether or a combination of at least two of the propylene glycol methyl ether acetate, the ethylene glycol ethyl ether acetate and the dipropylene glycol methyl ether;

preferably, the low-boiling point non-benzene solvent is selected from any one or a combination of at least two of propylene glycol methyl ether, butyl acetate or ethyl acetate;

preferably, the mass ratio of the high-boiling point non-benzene solvent to the low-boiling point non-benzene solvent in the second non-benzene organic solvent is (2-5): 1;

preferably, the first non-benzene organic solvent is selected from any one of high-boiling point non-benzene solvents in the second non-benzene organic solvent or a combination of at least two of the high-boiling point non-benzene solvents;

preferably, the third non-benzene organic solvent is selected from any one of or a combination of at least two of the high boiling point non-benzene solvents in the second non-benzene organic solvent.

6. The method according to any one of claims 1 to 5, wherein the mass of the partial initiator in step 1) is 60 to 90% based on 100% of the total mass of the initiator;

preferably, the temperature of the temperature rise in the step 2) is 90-130 ℃, preferably 115-125 ℃;

preferably, the dropping time of the step 2) is 1.5 to 3.5 hours, preferably 2.5 to 3 hours;

preferably, the temperature of the heat preservation in the step 2) is 90-130 ℃, preferably 115-125 ℃;

preferably, the incubation time in step 2) is 1-3h, preferably 1.5-2 h.

7. The method according to any one of claims 1 to 6, wherein the temperature for the dropwise addition in step 4) is 90 to 130 ℃, preferably 115-125 ℃;

preferably, the dripping time in the step 4) is 10-30min, preferably 15-25 min;

preferably, the temperature of the heat preservation in the step 4) is 90-130 ℃, preferably 115-125 ℃;

preferably, the heat preservation time in the step 4) is 1-4h, preferably 2-3 h;

preferably, step 2) and step 4) are accompanied by stirring;

preferably, the stirring speed in the step 2) and the step 4) is 40-70r/min, preferably 50-60 r/min.

8. A diffusion film resin solution produced by the production method according to any one of claims 1 to 7.

9. The diffusion membrane resin solution of claim 8, wherein the diffusion membrane resin solution has a solids content of 45-55%;

preferably, the viscosity of the diffusion film resin solution is 4000-7000 cps.

10. The diffusion film resin solution as claimed in claim 8 or 9, wherein in the diffusion film resin solution, the weight average molecular weight of the diffusion film resin is 36000-42000;

preferably, in the diffusion film resin solution, the glass transition temperature of the diffusion film resin is 20-60 ℃.

Technical Field

The invention relates to the technical field of coatings for optical films, in particular to a preparation method of a diffusion film resin solution and the diffusion film resin solution prepared by the same.

Background

The diffusion film is an optical film used in a thin film transistor liquid crystal display (TFT-LCD) backlight module, and mainly has the function of uniformly diffusing light rays emitted by a point-shaped or linear light source through a coating with a light diffusion function to form a surface light source. When the diffusion film is finally applied, the diffusion film is cut into sheets for use, the edges can fall off during cutting, and the diffusion film can be adsorbed onto the diffusion film sheets under the action of static electricity, so that the appearance quality is influenced; in addition, due to static electricity, adsorption action can be generated between the sheets, the sheets are not easy to separate, and the back surface of the sheet product is easy to scratch due to friction when the sheet product is taken and used. The conventional method for solving the above problems is to coat a protective coating layer having special functions of antistatic property, wear resistance, etc. on the back surface of the diffusion film.

Generally, when the diffusion film is applied, the surface coating and the back coating of the diffusion film are manufactured by two types of resin coating liquid, so that the product line is complex, and the use of downstream manufacturers is more complicated.

CN106990457A discloses a diffusion film back coating liquid and a preparation method and a use method thereof. The diffusion film back coating liquid comprises, by mass, 8-10 parts of a main agent, 1-2 parts of a polyisocyanate curing agent and 5-10 parts of a first organic solvent; the main agent comprises an acrylate resin solution prepared from 40-60 parts by weight of a specific monomer composition, 40-50 parts by weight of a second organic solvent and 0.5-2 parts by weight of an initiator. And coating the diffusion film back coating liquid on the back surface of the diffusion film, and curing at the temperature of 120-130 ℃ to obtain the diffusion film back coating. The coating prepared by the diffusion film back coating liquid has proper hardness, higher adhesive force, higher scratch resistance, higher transmittance and high temperature and high humidity resistance. But the glass transition temperature of the acrylic resin in the diffusion film back coating liquid is 50-90 ℃, and the diffusion film back coating liquid can not be applied to the application field of diffusion film surface coating.

Therefore, the development of a universal diffusion film resin which can be used for back coating and can meet the requirements of the back coating film is a difficult problem to be solved at present.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a preparation method of a diffusion film resin solution and the diffusion film resin solution prepared by the preparation method, wherein the preparation method adopts the two-step dropping process, so that the viscosity of the prepared diffusion resin solution is 4000-7000cps, the weight-average molecular weight of the diffusion resin is 36000-42000, and the glass transition temperature is 20-60 ℃, thus obtaining the universal diffusion resin solution which can be used for both surface coating and back coating, and meanwhile, the whole reaction process is stable and mild under the matching of the process flow and the process parameters.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for preparing a resin solution for a diffusion membrane, the method comprising the steps of:

1) mixing an acrylic monomer, a part of initiator and a first non-benzene organic solvent to obtain a first drop of liquid;

2) under the protection of inert gas, heating a second non-benzene organic solvent, dropwise adding the first added liquid obtained in the step 1), and preserving heat after dropwise adding is finished to obtain a reaction liquid;

3) mixing the rest part of the initiator with a third non-benzene organic solvent to obtain a second dropping liquid;

4) and (3) dropwise adding the second dropwise adding liquid obtained in the step 3) into the reaction liquid obtained in the step 2), and preserving heat after dropwise adding is completed to obtain the diffusion film resin solution.

The preparation method comprises the steps of firstly adding a mixed solution of an acrylic monomer, a part of initiator and a first non-benzene organic solvent into a second non-benzene solvent in a dropwise manner, then adding the rest of initiator and a third non-benzene organic solvent into a reaction solution in a dropwise manner, and enabling the viscosity of the prepared diffusion resin solution to be 4000-7000cps, the weight-average molecular weight of the diffusion resin to be 36000-42000 and the glass transition temperature to be 20-60 ℃ by adopting the two-step dropwise adding process, so that the universal diffusion resin solution which can be used for both top coating and back coating is obtained, and meanwhile, under the coordination of the process flow and the process parameters, the whole reaction process is stable and mild. In addition, the preparation method adopts non-benzene organic solvents, so that the whole reaction process is more environment-friendly.

Preferably, the acrylic monomer is selected from a combination of at least three of methyl methacrylate, butyl acrylate, methacrylic acid, acrylic acid, hydroxyethyl methacrylate, hydroxyethyl acrylate, cyclohexyl methacrylate or ethyl acrylate, and may be, for example, methyl methacrylate, a combination of butyl acrylate and cyclohexyl methacrylate, methacrylic acid, a combination of acrylic acid and cyclohexyl methacrylate, hydroxyethyl methacrylate, a combination of hydroxyethyl acrylate and cyclohexyl methacrylate, a combination of hydroxyethyl acrylate, cyclohexyl methacrylate and ethyl acrylate, or the like.

According to the invention, the combination of at least three of the specific monomers is selected as a reaction raw material, so that the prepared acrylic resin has a specific molecular weight and a glass transition temperature range, and the viscosity and solid content of the prepared acrylic resin solution are moderate, so that the acrylic resin solution can be used as a diffusion film back coating liquid and a diffusion film surface coating liquid, and the complex steps of preparing the diffusion film surface coating and the diffusion film back coating into two types of resin coating liquids in the application of the prior art are simplified.

Preferably, the initiator is selected from any one of tert-butyl peroxybenzoate, azobisisobutyronitrile, tert-butyl peroxy2-ethylhexanoate or di-tert-butyl peroxide or a combination of at least two of the above.

The amount of the acrylic monomer added is preferably 40 to 60%, for example, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, or the like, preferably 45 to 50%, based on 100% by mass of the total diffusion film resin solution.

The amount of the initiator added is preferably 0.5 to 4%, for example, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, or the like, preferably 1.5 to 2.5%, based on 100% by mass of the total diffusion film resin solution.

The second non-benzene organic solvent is preferably added in an amount of 20 to 45%, for example, 20%, 21%, 23%, 25%, 26%, 28%, 30%, 32%, 35%, 37%, 40%, 42%, 45%, or the like, preferably 35 to 40%, based on 100% by mass of the total diffusion film resin solution.

Preferably, the mass ratio of the first non-benzene organic solvent to the third non-benzene organic solvent is (1.5-5: 1), and may be, for example, 1.5:1, 1.8:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, or 5:1, and is preferably (2-4: 1).

Preferably, the second non-benzene organic solvent includes a high-boiling point non-benzene solvent and a low-boiling point non-benzene solvent.

The "high-boiling-point non-benzene solvent" in the present invention means a non-benzene solvent having a boiling point of higher than 130 ℃, and the "low-boiling-point non-benzene solvent" in the present invention means a non-benzene solvent having a boiling point of lower than 130 ℃.

Preferably, the high-boiling point non-benzene solvent is selected from any one of propylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate or dipropylene glycol methyl ether or a combination of at least two of the propylene glycol methyl ether acetate, the ethylene glycol ethyl ether acetate and the dipropylene glycol methyl ether.

Preferably, the low-boiling point non-benzene solvent is selected from any one or a combination of at least two of propylene glycol methyl ether, butyl acetate or ethyl acetate.

Preferably, the mass ratio of the high-boiling point non-benzene solvent to the low-boiling point non-benzene solvent in the second non-benzene organic solvent is (2-5: 1), and may be, for example, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, or 5: 1.

The preferred mass ratio of the high-boiling point non-benzene solvent to the low-boiling point non-benzene solvent in the second non-benzene organic solvent is controlled within the above range, so as to ensure that the obtained diffusion film resin is compatible with diffusion particles during actual film coating, so that the appearance of the film coating meets the performance requirement, and a single solvent system can generate the conditions that the appearance is poor, the film coating is incompatible with an auxiliary agent and the like to influence the film coating effect in actual application.

Preferably, the first non-benzene organic solvent is selected from any one of high boiling point non-benzene solvents in the second non-benzene organic solvent or a combination of at least two of the high boiling point non-benzene solvents.

Preferably, the third non-benzene organic solvent is selected from any one of or a combination of at least two of the high boiling point non-benzene solvents in the second non-benzene organic solvent.

In the invention, the first non-benzene organic solvent and the third non-benzene organic solvent are both high-boiling-point solvents and are selected from one or a combination of at least two of the high-boiling-point solvents in the second non-benzene organic solvent, because the heat preservation temperature in the step 2) is higher, and in order to reduce the loss of the solvents caused by the boiling point lower than the heat preservation temperature, the first non-benzene organic solvent and the third non-benzene organic solvent are both high-boiling-point solvents. Meanwhile, the first non-benzene organic solvent and the third non-benzene organic solvent are both high-boiling-point solvents, so that the mass ratio of the whole high-boiling-point non-benzene solvent to the whole low-boiling-point non-benzene solvent in the resin can be further controlled within a certain range.

Preferably, the mass proportion of the partial initiator in the step 1) is 60 to 90% based on 100% of the total mass of the initiator, and may be, for example, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or the like.

The invention preferably controls the mass ratio of part of the initiator in the step 1) to be within the above range, so as to take account of the reaction speed of the step 1) and the molecular weight range of the finally obtained acrylic resin, when the content of the initiator added in the step 1) is higher than 90% of the total mass of the initiator, the reaction rate of the step 1) is too high, and the molecular weight of the obtained acrylic resin is too high; and when the content of the added initiator is less than 60 percent of the total mass of the initiator, the reaction in the step 1) is incomplete, the molecular weight of the obtained acrylic resin is too low, and the molecular weight of the acrylic resin cannot be effectively improved even if the initiator is added subsequently.

Preferably, the heating temperature in step 2) is 90-130 ℃, for example, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃, preferably 115-125 ℃.

Preferably, the dropping time of the step 2) is 1.5-3.5h, for example, 1.5h, 2h, 2.5h, 3h or 3.5h, etc., preferably 2.5-3 h.

Preferably, the temperature of the heat preservation in step 2) is 90-130 ℃, for example, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃, etc., preferably 115-125 ℃.

Preferably, the incubation time in step 2) is 1-3h, for example 1h, 1.5h, 2h, 2.5h or 3h, etc., preferably 1.5-2 h.

Preferably, the temperature for the dropwise addition in the step 4) is 90-130 ℃, for example, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃ or 130 ℃, preferably 115-125 ℃.

Preferably, the dropping time in step 4) is 10-30min, such as 10min, 15min, 20min, 25min or 30min, preferably 15-25 min.

Preferably, the temperature of the heat preservation in step 4) is 90-130 ℃, for example, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃ or 130 ℃, preferably 115-125 ℃.

Preferably, the incubation time in step 4) is 1-4h, for example, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h or 4h, etc., preferably 2-3 h.

Preferably, step 2) and step 4) are accompanied by stirring.

Preferably, the stirring speed in step 2) and step 4) is 40-70r/min, such as 40r/min, 45r/min, 50r/min, 55r/min, 60r/min, 65r/min or 70r/min, preferably 50-60 r/min.

Preferably, the preparation method comprises the following steps:

1) mixing an acrylic monomer, a part of initiator and a first non-benzene organic solvent to obtain a first drop of liquid;

2) under the protection of inert gas, heating a second non-benzene organic solvent to 90-130 ℃ at a stirring speed of 40-70r/min, dropwise adding the first drop of liquid obtained in the step 1), keeping the temperature at 90-130 ℃, keeping the stirring speed at 40-70r/min, completing the dropwise adding process within 1.5-3.5h, and continuously preserving heat at 90-130 ℃ for 1-3h to obtain a reaction solution;

3) mixing the rest part of the initiator with a third non-benzene organic solvent to obtain a second dropping liquid;

4) and (3) dropwise adding the second dropwise adding liquid obtained in the step 3) into the reaction liquid obtained in the step 2), keeping the temperature at 90-130 ℃ in the dropwise adding process, stirring at the rotating speed of 40-70r/min, completing the dropwise adding process within 10-30min, and continuously preserving the heat for 1-4h at 90-130 ℃ to obtain the diffusion film resin solution.

In a second aspect, the present invention provides a diffusion film resin solution prepared by the preparation method according to the first aspect.

Preferably, the solids content of the diffusion membrane resin solution is 45-55%, and may be, for example, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, or 55%, etc.

Preferably, the viscosity of the diffusion film resin solution is 4000-7000cps, and may be 4000cps, 4500cps, 5000cps, 5500cps, 6000cps, 6500cps, 7000cps, or the like, for example.

Preferably, in the diffusion film resin solution, the weight average molecular weight of the diffusion film resin is 36000-42000, and may be 36000, 37000, 38000, 39000, 40000, 41000 or 42000, for example.

Preferably, the glass transition temperature of the diffusion film resin in the diffusion film resin solution is 20 to 60 ℃, and may be, for example, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃ or 60 ℃.

Compared with the prior art, the invention has the following beneficial effects:

(1) the preparation method comprises the steps of adding a mixed solution of an acrylic monomer, a part of initiator and a first non-benzene organic solvent into a second non-benzene solvent in a dropwise manner, then adding the rest of initiator and a third non-benzene organic solvent into a reaction solution in a dropwise manner, and obtaining a universal diffusion resin solution which can be used for both surface coating and back coating by adopting the two-step dropwise adding process, wherein the viscosity of the prepared diffusion resin solution is 4000-7000cps, the weight average molecular weight of the diffusion resin is 36000-42000, and the glass transition temperature is 20-60 ℃, and meanwhile, under the coordination of the process flow and the process parameters, the whole reaction process is stable and mild;

(2) the preparation method provided by the invention adopts non-benzene organic solvents, so that the whole reaction process is more environment-friendly.

Detailed Description

The present invention is described in further detail below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.

The mass fractions of the materials in each example and comparative example are based on 100% of the total mass of the diffusion film resin solution prepared in the example or comparative example.