TWI739390B - Laminated structure, method for manufacturing the same and container made of laminated structure - Google Patents

Abstract

A laminated structure, method for manufacturing the same and container made of the laminated structure are provided. The method includes: providing a waterproof coating; painting the waterproof coating on a base layer by a roll-type screen printing; and drying the painted base layer to form a laminated structure by providing a cold air and a hot air alternatively to the painted base layer. The laminated structure includes a coating layer forming by the coating and the base layer. The hot air includes a first hot air and a second hot air which have different temperatures.

Description

Laminated structure, its manufacturing method and its made container

The present invention relates to a laminated structure, a manufacturing method thereof, and a container made thereof, and in particular to a food contact grade laminated structure, a manufacturing method thereof, and a container made thereof.

The surface of the food container is usually coated with a layer of coating to prevent the liquid from oozing out of the food container when holding food or beverages. At present, polyethylene (PE), polypropylene (PP) and chlorinated polyethylene (CPE) are commonly used as food The coating of the container, but also due to the plastic components coated on the substrate, the substrate cannot be recycled and cannot be biodegraded. And in order to make the coated and coated substrates can be bonded and formed, the currently developed paper with blister characteristics is obtained by first coating the coated and lacquered paper with a coating with blister characteristics. In order to be able to use temperature changes to bond the paper during the forming step, this increases the time and cost of the composite material that must be manufactured first.

In addition, the coating thickness of the current common traditional flat-sheet screen printing cannot be controlled or dried immediately, which makes the printing process time-consuming and labor-intensive. Therefore, there is still a need to develop a method that can be uniformly coated and quickly and reliably dried to prevent the coated substrate from sticking back.

In view of the shortcomings of the conventional technology, the purpose of the present invention is to provide a laminated structure, its manufacturing method and the container made thereof, especially the food contact grade laminated structure, its manufacturing method and the container made thereof, the method of the present invention Coating, drying and winding are carried out in a continuous operation mode, which greatly reduces time and labor costs, and the laminated structure can be coated in a single layer, that is, it has high waterproof and blister characteristics, and can be widely used in various food containers. , Has more use value in industry.

According to the object of the present invention, the present invention provides a method for manufacturing a laminated structure, which includes: providing a waterproof coating; coating the waterproof coating on a base layer by using a roller-type mesh plate; and alternately providing cold air and hot air to the substrate The coated base layer is dried to form a laminated structure. The laminated structure includes a coating formed by a waterproof coating and a base layer; wherein the hot air includes a first hot air and a second hot air with different temperatures.

Preferably, the hot air further includes a third hot air, and the temperature of the third hot air is different from the first hot air and the second hot air.

Preferably, the temperature of the hot air is 70 to 180 degrees, the temperature of the third hot air is higher than the temperature of the second hot air, and the temperature of the second hot air is higher than the temperature of the first hot air.

Preferably, the mesh of the roll-type screen is 100 mesh to 300 mesh, and the thickness of the coating is 0.01 cm to 0.03 cm.

Preferably, the viscosity of the waterproof coating is 2000 cps to 3000 cps.

Preferably, the temperature of the cold air is room temperature.

Preferably, the waterproof coating includes a solvent and a plurality of coating particles dispersed in the solvent.

Preferably, the plurality of coating particles include a crosslinking agent, an acrylate monomer, and a diacetone acrylamide monomer.

According to the purpose of the present invention, the present invention provides a laminated structure prepared according to the aforementioned method.

According to the object of the present invention, the present invention provides a container made according to the aforementioned laminated structure.

Based on the above, the laminated structure of the present invention, its manufacturing method and the container made thereof have the following advantages: the manufacturing method of the laminated structure of the present invention uses roller-type screen coating, which can adjust the mesh and position according to requirements. The thickness of the coating is required, and the excess paint can be recycled under the reel-type screen to avoid paint waste and pollution. Moreover, the coating, drying and winding of the present invention are continuous operations, which can effectively control the coating thickness and drying efficiency. After drying, it is also directly rolled into a cylindrical shape to facilitate subsequent storage, transportation and cutting operations. , Compared with traditional flat-sheet screen printing, it can save a lot of time and labor costs. It is worth noting that the water-based resin coating of the present invention has good compatibility with paper and can promote the strengthening of the paper structure, thereby enhancing the rigidity and strength of the coated paper.

The laminated structure manufactured by the manufacturing method of the present invention has both waterproof and blister characteristics. The blister feature enables the waterproof coating of the present invention to achieve adhesion and convenient molding through changes in temperature and heat. Because the laminated structure manufactured by the manufacturing method of the present invention does not need to be coated with additional adhesive materials when making food containers, only a single coating process can have the effects of waterproofing and blistering at the same time, which effectively saves the cost of manufacturing food containers as a whole. Time and raw material cost.

The waterproof coating of the present invention only uses water as a solvent, so the prepared waterproof coating is neither volatile nor flammable, and has a simple storage method. In addition, in the absence of volatility, The composition of the coating coated with the waterproof coating of the present invention is stable and not easy to turn yellow. The most important thing is that the waterproof coating of the present invention does not contain substances harmful to the human body and the environment, so it can be used as a water-based environmentally friendly coating.

S1~S3: steps

10: basal layer

20: Coating

30: Paint particles

31: Shell

32: core

33: Crosslinking agent

34: Acrylic amine monomer

35, 35a, 35b: Acrylic monomers

40: Screen version

41: Scraper

42: mesh

50: oven

51: The first oven

52: The second oven

53: The third oven

54: The fourth oven

55: Fifth oven

56: Vent

C1~C5: cold wind

D1~D5: length

H1~H5: hot air

The following figures are used to further illustrate the present invention: Figure 1 is a flow chart of the manufacturing method of the laminated structure of the present invention.

Figure 2 is a schematic diagram of the laminated structure of the present invention.

Figure 3 is a schematic diagram of the coating particles of the present invention.

Figure 4 is a schematic diagram of the roll-type screen of the present invention.

Figure 5 is a schematic diagram of the drying process of the present invention.

To enable those with ordinary knowledge in the technical field to understand the technical features, specific implementations and benefits of the laminated structure of the present invention and the containers made thereof, the following will be described in more detail with examples.

The term "blister" in this article specifically refers to the phenomenon that the paint changes from solid to liquid when heated to 40℃~90℃, so it can be achieved by using temperature changes to convert the paint between solid and liquid. The effect of "self-adhesive when heated" is similar to the effect of hot melting. The term "degrees" for temperature in this article refers specifically to the temperature in degrees Celsius.

Referring to Figures 1 to 3, which are respectively a flow chart of the manufacturing method of the laminated structure of the present invention, a schematic diagram of the laminated structure of the present invention, and a schematic diagram of the coating particles of the present invention. The present invention provides a method for manufacturing a laminated structure, which includes:

Step S1: Provide a waterproof paint, which includes a solvent and a plurality of paint particles 30 dispersed in the solvent. In an embodiment of the present invention, the plurality of coating particles 30 includes a cross-linking agent 33, an acrylate monomer 35, and a diacetone acrylamide monomer 34. Moreover, the crosslinking agent 33 may be a moisture-reactive crosslinking agent, which is used to bridge the reaction with the acrylic monomer 35 and the diacetone acrylamide monomer 34 to complete the coating particles 30 of the present invention. The particle size of the coating particles 30 is 0.1 μm to 1 μm, preferably 0.2 μm to 0.8 μm, and more preferably 0.4 μm to 0.6 μm.

In an embodiment, the solvent may be water. The crosslinking agent 33 may be dihydrazine adipate (ADH, C ₆ H ₁₄ N ₄ O ₂ , CAS. NO. 213-999-5). Wherein, the content of the crosslinking agent 33 may be 1-20 parts by weight, preferably 5-20 parts by weight, more preferably 5-15 parts by weight. The content of the acrylic monomer 35 may be 55 to 170 parts by weight, preferably 60 to 150 parts by weight, more preferably 60 to 100 parts by weight. The content of diacetone acrylamide monomer 34 may be 1-20 parts by weight, preferably 5-20 parts by weight, more preferably 10-20 parts by weight.

Furthermore, the acrylate monomer 35 can be selected from isodecyl (meth)acrylate (IDMA, C ₁₄ H ₂₆ O ₂ , CAS.NO.29964-84-9), methyl (meth)acrylate ( MMA, C ₅ H ₈ O ₂ , CAS.NO.80-62-6), butyl acrylate (BA, C ₇ H ₁₂ O ₂ , CAS.NO.141-32-2), isooctyl acrylate (2 -EHA, C ₁₁ H ₂₀ O ₂ , CAS.NO.29590-42-9) and any combination thereof.

In detail, the content of isodecyl (meth)acrylate may be 15-30 parts by weight, preferably 18-30 parts by weight, more preferably 20-30 parts by weight. The content of methyl (meth)acrylate may be 10-50 parts by weight, preferably 10-30 parts by weight, more preferably 10-20 parts by weight. Butyl acrylate The content may be 20 to 80 parts by weight, preferably 20 to 50 parts by weight, more preferably 20 to 30 parts by weight. The content of isooctyl acrylate may be 2-20 parts by weight, preferably 5-20 parts by weight, more preferably 10-20 parts by weight.

Diacetone acrylamide monomer 34 is a reactive multifunctional monomer with double bonds in its molecule, which can carry out free radical homopolymerization. The ketone carbonyl group on the molecule of diacetone acrylamide 34 is combined with Dihydrazine adipic acid is formed into a network of cross-linking and bridging, thereby improving the waterproof properties. The content of diacetone acrylamide monomer 34 may be 1-20 parts by weight, preferably 10-20 parts by weight. The content of methacrylic acid may be 4-10 parts by weight, preferably 5-10 parts by weight.

In an embodiment, the coating particles 30 may have a core-shell structure obtained by an emulsification cross-linking reaction, and the core-shell structure includes a core 32 and an outer shell 31. The weight ratio of the core 32 to the shell 31 may be 6:4 to 8:2, preferably 5:5 to 3:7. In one embodiment, the coating particles 30 can be divided into two parts: a core 32 and a shell 31. The core 32 uses acrylic monomer 35b as the main component, and may further include diacetone acrylamide monomer 34; and the outer shell 31 uses acrylic monomer 35a as the main component, and may further include acrylic monomer or Hydroxyl acrylate monomers, and dihydrazide adipate. The "main component" in this text means that its total weight accounts for more than 50% of the total weight of all monomers of the copolymer of the part. For example, the acrylic monomer 35 in the core part accounts for more than 50% of the total weight of the core part. More than 50% of the total weight of all monomers in the copolymer.

In one embodiment, the acrylic monomer 35b of the core 32 may include (meth)acrylic acid C ₁ ~C ₁₀ alkyl ester, (C ₁ -C ₄ alkyl) acrylic monomer, and diacetone acrylamide monomer. Body 34; The acrylic monomer 35a of the shell 31 may include (meth)acrylic acid C ₁ -C ₈ alkyl ester, (C ₁ -C ₄ alkyl) acrylic monomer and hydroxyl-containing (meth)acrylic acid C ₁ -C ₈ alkyl ester monomers.

In one embodiment, when the total weight of all monomers in the core 32 is used as a basis, the content of isodecyl (meth)acrylate contained in the core 32 is 15-50 parts by weight, preferably 18-50 parts by weight. Parts by weight, more preferably 20-50 parts by weight; content of methyl (meth)acrylate is 5-50 parts by weight, preferably 8-40 parts by weight, more preferably 10-40 parts by weight; butyl acrylate The content is 30-100 parts by weight, preferably 30-50 parts by weight, more preferably 30-40 parts by weight; the content of isooctyl acrylate is 2-25 parts by weight, preferably 5-25 parts by weight, more preferably It is 9-25 parts by weight; and the content of diacetone acrylamide monomer 34 is 0.8-25 parts by weight, preferably 8-25 parts by weight, more preferably 9-25 parts by weight.

In one embodiment, when the total weight of all monomers in the housing 31 is used as a reference, the content of methyl (meth)acrylate contained in the housing 31 is 20-50 parts by weight, preferably 22-48 parts by weight. Parts, more preferably 25~45 parts by weight; content of butyl acrylate is 15~50 parts by weight, preferably 15~45 parts by weight, more preferably 15~40 parts by weight; content of methacrylic acid is 3~20 Parts by weight, preferably 5-15 parts by weight, more preferably 5-10 parts by weight; and the content of dihydrazine adipate is 1-20 parts by weight, preferably 5-20 parts by weight, more preferably 10 ~20 parts by weight.

The glass transition temperature (Tg) of the core 32 of the waterproof blister coating of the present invention can be -40°C to 90°C, preferably -40°C to 60°C, more preferably -40°C to 50°C; the glass of the shell 31 The conversion temperature may be 10°C to 90°C, preferably 10°C to 75°C, more preferably 20°C to 70°C. Among them, the Tg value of the core 32 is at least 10°C or more lower than the Tg value of the shell 31, preferably 20°C or more, and more preferably 25°C or more. Among them, the Tg difference between the shell 31 and the core 32 is set according to the hardness of the coating layer, that is, depending on the setting of the feel and viscosity. Specifically, when the coating layer is soft, the hand feels more sticky, and when the coating layer is hard, the hand feels better. It is not sticky. When the Tg is too large, it will have the disadvantages of waterproofing, poor thermal melting and no flexibility of the coating layer. Although the Tg is too small, although the thermal melting effect can be enhanced and the coating layer has flexibility, the waterproof effect is poor and the hand feel may be sticky.

On the other hand, the manufacturing method of the waterproof blister coating of the present invention is described in detail as follows:

Step S1: Add the first monomer to the aqueous solution containing the first emulsifier, and stir to form a first mixture. In detail, the first monomer may include isodecyl (meth)acrylate, methyl (meth)acrylate, butyl acrylate, diacetone acrylamide, and isooctyl acrylate. The first emulsifier may be an anionic surfactant or a composite emulsifier composed of long-chain alkanes. Specifically, the first emulsifier may be sodium dodecyl phenyl sulfonate. And based on the total weight of the reacted monomers, the content of the first emulsifier may be 0.1 to 1 parts by weight, preferably 0.2 to 0.8 parts by weight, more preferably 0.4 to 0.6 parts by weight. The aqueous solution may be water.

Step S2: Add the second monomer and dihydrazine adipic acid (ADH) to the aqueous solution containing the second emulsifier, and stir to form a second mixture. In detail, the second monomer may include methyl (meth)acrylate, butyl acrylate, and methacrylic acid. The type and content of the second emulsifier can be selected as defined in the aforementioned first emulsifier, and the type and content of the second emulsifier can be different from the first emulsifier.

Step S3: adding baking soda powder to the aqueous solution containing the third emulsifier, stirring and heating to a predetermined temperature, and then adding an accelerator to react for a predetermined time to obtain a third mixture. The type and content of the third emulsifier can be selected as defined in the aforementioned first emulsifier, and the type and content of the third emulsifier can be different from the first emulsifier and the second emulsifier. The accelerator may be Ammonium persulphate (APS) and Potassium persulfate (KPS). Based on the total weight of the reacted monomers, the content of the accelerator may be 0.1 to 1 part by weight, preferably 0.2 to 0.9 part by weight, more preferably 0.5 to 0.9 part by weight. The predetermined temperature can be 70°C~80°C, preferably 72℃~78℃, more preferably 74℃~76℃. The predetermined time is 15-25 minutes, preferably 18-22 minutes, more preferably 19-21 minutes.

After the aforementioned mixtures are separately configured, step S4 is performed: adding the first mixture to the third mixture, and reacting for the first time at the first reaction temperature to obtain the fourth mixture. The first reaction temperature is 75°C to 80°C, preferably 76°C to 79°C, more preferably 77°C to 78°C. The first time may be 2.5 to 4 hours, preferably 3 to 4 hours, and more preferably 3 to 3.5 hours.

Then proceed to step S5: adding the second mixture to the fourth mixture, and reacting for a second time at the second reaction temperature to obtain the waterproof blister coating. The second reaction temperature may be 75°C to 80°C, preferably 76°C to 79°C, more preferably 77°C to 78°C. The second time is 1.5 to 2.5 hours, preferably 1.8 to 2.2 hours, more preferably 1.9 to 2.1 hours.

Furthermore, the first mixture and the second mixture may be water in oil emulsions. The coating particles 30 of the waterproof blister coating of the present invention have a core-shell structure. The core-shell structure includes a core 32 formed from the aforementioned first mixture and an outer shell 31 formed from the aforementioned second mixture. Therefore, in the form of an oil-in-water emulsion, each coating particle 30 of the waterproof blister coating of the present invention has a core-shell structure, and the core 32 formed by the first mixture can be waterproof, and the second mixture is formed by the The outer shell 31 has the characteristics of blister, so that the waterproof blister coating of the present invention can achieve the purpose of bonding by changing the temperature and heat.

The waterproof blister coating of the present invention can be coated by gravure cylinder coating, knife coating, roll coating or slit coating, screen coating, various coating methods known to those with ordinary knowledge in the technical field, etc. Coated on the substrate. Preferably, it is coated by a gravure roller, and the substrate can be paper, wood, metal, or any material capable of forming a continuous coating film thereon. As long as a continuous coating film can be formed on the substrate after drying, the present invention does not limit the substrate that can be coated. system. Preferably, it can be coated on paper to replace the coating of paper food containers. The thickness of the coating film layer coated on the substrate is 10-50 μm, preferably 10-40 μm, more preferably 10-30 μm. Among them, when the thickness is less than 10μm, it will have the disadvantages of reduced water resistance and blister function; and when the thickness is greater than 50μm, although it has waterproof and blister functions, it will have the disadvantage that the paper coating layer has a sticky feeling.

Specifically, to prepare the coating particles 30 of the present invention, the formulation of the coating particles 30 can be divided into two parts: the core 32 and the shell 31. The Tg value calculation formula is 1/Tg=w1/Tg1+w2/Tg2 to calculate the Tg values of the core 32 and the shell 31 respectively, where Tg is the glass transition temperature generated by mixing two or more monomers, w1 and w2 are The weight percentage of the mixed monomers, Tg1 and Tg2 are the glass transition temperatures of the mixed monomers.

The monomers that can be used and their characteristics are listed in Table 1, but the examples of the present invention are not limited to this.

To further illustrate the water resistance and plasticity of the coating particles 30 of the waterproof blister coating in this case, specific examples of the present invention are as follows: Example 1, the ratio between the monomers of the formula used is shown in Table 2 below:

In detail, in Example 1, the weight ratio of the core to the shell is 6:4.

The detailed ratio between the core constituent monomers is shown in Table 3 below:

The detailed proportions of the monomers of the shell are shown in Table 4 below:

The preparation method of Example 1 is as follows:

First, 3g of diacetone acrylamide, 25g of methyl (meth)acrylate, 50g of butyl acrylate, 4g of isooctyl acrylate and 18g of (meth)isodecyl acrylate, 45ml of water and 0.5g of low molecular weight emulsifier The core composition mixture is stirred to form a water in oil emulsion. Then 30g of methyl (meth)acrylate, 26g of butyl acrylate, 8g of methacrylic acid and 2g of dihydrazide adipic acid, 13.5ml of water and 0.1g of low molecular weight emulsifier are fully stirred to form a shell composition mixture of an oil-in-water emulsion .

Then in a 500ml reaction tank, 0.415g of baking soda, 83ml of water and 0.249g of sodium dodecylphenylsulfonate were stirred and heated to 70~80℃, and 0.83g of ammonium persulphate (Ammonium persulphate, APS) or potassium persulfate (KPS) is used as an initiator to react for 20 minutes. Then, the core composition mixture is added to react at 75-85°C for 3 to 3.5 hours, and after 20 minutes, the shell composition monomer mixture is added to react at 75-85°C for 2 hours. After the copolymerization reaction is completed, add 1.245g of ammonium persulfate, and react again at 75~90°C for 2 hours to make the copolymerization reaction more complete. After the copolymerization reaction is completed, the reaction tank is cooled to 40°C, and _{neutralized to pH 7~9 with 25% NH 4} OH aqueous solution to obtain an aqueous dispersion containing core-shell structured emulsified polymer particles, and if the resulting aqueous dispersion is used The total weight of the dispersion is based on 100 parts by weight, and the resulting aqueous dispersion has 50 parts by weight of solid content and a viscosity of 13-20sec (ASTM Ford No. 4 viscosity cup). Further, the obtained emulsion polymer particles are particles having an average particle diameter of 1 μm and a core-shell structure, and the core Tg value of the particle structure is -15°C; and the Tg of the outer shell copolymer is 10°C.

In Example 2, the ratio between the monomers of the formula used is shown in Table 5 below:

In detail, in Example 2, the weight ratio of the core to the shell is 6:4.

The detailed ratios between the core monomers are shown in Table 6 below:

The detailed ratio between the monomers of the shell is shown in Table 7 below:

The preparation method of Example 2 is as follows:

First, 3g of diacetone acrylamide, 15g of methyl (meth)acrylate, 50g of butyl acrylate, 7g of isooctyl acrylate, 25g of (meth)isodecyl acrylate, 45ml of water and 0.5g of low molecular weight emulsifier The core composition mixture is stirred to form a water in oil emulsion. Then 30g of methyl (meth)acrylate, 20g of butyl acrylate, 7g of methacrylic acid and 9g of dihydrazide adipic acid, 13.5ml of water and 0.1g of low molecular weight emulsifier are fully stirred to form a shell composition mixture of an oil-in-water emulsion .

Then in a 500ml reaction tank, 0.415g of baking soda, 83ml of water and 0.249g of sodium dodecylphenylsulfonate were stirred and heated to 70~80℃, and 0.83g of ammonium persulphate (Ammonium persulphate, APS) or potassium persulfate (KPS) is used as an initiator to react for 20 minutes. Then, the core composition mixture is added to react at 75-85°C for 3 to 3.5 hours, and after 20 minutes, the shell composition monomer mixture is added to react at 75-85°C for 2 hours. After the copolymerization reaction is completed, add 1.245g of ammonium persulfate, and react again at 75~90°C for 2 hours to make the copolymerization reaction more complete. After the copolymerization reaction is completed, the reaction tank is cooled to 40°C, and _{neutralized to pH 7~9 with 25% NH 4} OH aqueous solution to obtain an aqueous dispersion containing core-shell structured emulsified polymer particles, and if the resulting aqueous dispersion is used The total weight of the dispersion is based on 100 parts by weight, and the resulting aqueous dispersion has 50 parts by weight of solid content and a viscosity of 13-20sec (ASTM Ford No. 4 viscosity cup). Further, the obtained emulsified polymer particles are particles with an average particle diameter of 1 μm and a core-shell structure, and the Tg value of the core of the particle structure is -29°C; and the Tg of the outer shell copolymer is 25°C.

Example 3, the ratio between the monomers of the formula used is shown in Table 8 below:

In detail, in Example 3, the weight ratio of the core to the shell is 6:4.

The detailed ratio between the core constituent monomers is shown in Table 9 below:

The detailed ratio between the monomers of the shell is shown in Table 10 below:

The preparation method of Example 3 is as follows:

First, 15g of diacetone acrylamide, 10g of methyl (meth)acrylate, 44.5g of butyl acrylate, 7g of isooctyl acrylate and 23.5g of (meth)isodecyl acrylate, 45ml of water and 0.5g of low molecular weight emulsify The agent is thoroughly stirred to form the core composition mixture of the water in oil emulsion. Then 28.5g of methyl (meth)acrylate, 21.5g of butyl acrylate, 7g of methacrylic acid and 9g of dihydrazide adipate, 13.5ml of water and 0.1g of low molecular weight emulsifier are fully stirred to form the outer shell of an oil-in-water emulsion Make up a mixture.

Then in a 500ml reaction tank, 0.415g of baking soda, 83ml of water and 0.249g of sodium dodecylphenylsulfonate were stirred and heated to 70~80℃, and 0.83g of ammonium persulphate (Ammonium persulphate, APS) or potassium persulfate (KPS) is used as an initiator to react for 20 minutes. Then, the core composition mixture is added to react at 75-85°C for 3 to 3.5 hours, and after 20 minutes, the shell composition monomer mixture is added to react at 75-85°C for 2 hours. After the copolymerization reaction is completed, add 1.245g of ammonium persulfate, and react again at 75~90°C for 2 hours to make the copolymerization reaction more complete. After the copolymerization reaction is completed, the reaction tank is cooled to 40°C, and _{neutralized to pH 7~9 with 25% NH 4} OH aqueous solution to obtain an aqueous dispersion containing core-shell structured emulsified polymer particles, and if the resulting aqueous dispersion is used The total weight of the dispersion is based on 100 parts by weight, and the resulting aqueous dispersion has 50 parts by weight of solid content and a viscosity of 13-20sec (ASTM Ford No. 4 viscosity cup). Further, the obtained emulsified polymer particles are particles with an average particle diameter of 1 μm and a core-shell structure, and the core Tg value of the particle structure is -33°C; and the Tg of the outer shell copolymer is 21°C.

Example 4, the ratio between the monomers of the formula used is shown in Table 11 below:

In detail, in Example 4, the weight ratio of the core to the shell is 6:4.

The detailed ratios between the core constituent monomers are shown in Table 12 below:

The detailed ratios of the shell components are shown in Table 13 below:

The preparation method of Example 4 is as follows:

First, 15g of diacetone acrylamide, 17g of methyl (meth)acrylate, 32.5g of butyl acrylate, 12g of isooctyl acrylate and 23.5g of (meth)isodecyl acrylate, 45ml of water and 0.5g of low molecular weight emulsify The agent is thoroughly stirred to form the core composition mixture of the water in oil emulsion. Then 27g of methyl (meth)acrylate, 20.5g of butyl acrylate, 7g of methacrylic acid and 11.5g of dihydrazide adipate, 13.5ml of water and 0.1g of low molecular weight emulsifier are fully stirred to form the outer shell of an oil-in-water emulsion Make up a mixture.

Then in a 500ml reaction tank, 0.415g of baking soda, 83ml of water and 0.249g of sodium dodecylphenylsulfonate were stirred and heated to 70~80℃, and 0.83g of ammonium persulphate (Ammonium persulphate, APS) or potassium persulfate (KPS) is used as an initiator to react for 20 minutes. Then, the core composition mixture is added to react at 75-85°C for 3 to 3.5 hours, and after 20 minutes, the shell composition monomer mixture is added to react at 75-85°C for 2 hours. After the copolymerization reaction is completed, add 1.245g of ammonium persulfate, and react again at 75~90°C for 2 hours to make the copolymerization reaction more complete. After the copolymerization reaction is completed, the reaction tank is cooled to 40°C, and _{neutralized to pH 7~9 with 25% NH 4} OH aqueous solution to obtain an aqueous dispersion containing core-shell structured emulsified polymer particles, and if the resulting aqueous dispersion is used The total weight of the dispersion is based on 100 parts by weight, and the resulting aqueous dispersion has 50 parts by weight of solid content and a viscosity of 13-20sec (ASTM Ford No. 4 viscosity cup). Further, the obtained emulsified polymer particles are particles with an average particle diameter of 1 μm and a core-shell structure, and the core Tg value of the particle structure is -27°C; and the Tg of the outer shell copolymer is 30°C.

Example 5, the ratio between the monomers of the formula used is shown in Table 14 below:

In detail, in Example 5, the weight ratio of the core to the shell is 6:4.

The detailed ratios of the core constituent monomers are shown in Table 15 below:

The detailed ratio between the monomers of the shell is shown in Table 16 below:

The preparation method of Example 5 is as follows:

First, 15g diacetone acrylamide, 11g methyl (meth)acrylate, 32.5g butyl acrylate, 18g isooctyl acrylate and 23.5g (meth)isodecyl acrylate, 45ml water and 0.5g low molecular weight emulsification The agent is thoroughly stirred to form the core composition mixture of the water in oil emulsion. Then 27.5g of methyl (meth)acrylate, 19.5g of butyl acrylate, 6g of methacrylic acid and 13g of dihydrazide adipate, 13.5ml of water and 0.1g of low molecular weight emulsifier are fully stirred to form the outer shell of an oil-in-water emulsion Make up a mixture.

Then in a 500ml reaction tank, 0.415g of baking soda, 83ml of water and 0.249g of sodium dodecylphenylsulfonate were stirred and heated to 70~80℃, and 0.83g of ammonium persulphate (Ammonium persulphate, APS) or potassium persulfate (KPS) is used as an initiator to react for 20 minutes. Then, the core composition mixture is added to react at 75-85°C for 3 to 3.5 hours, and after 20 minutes, the shell composition monomer mixture is added to react at 75-85°C for 2 hours. After the copolymerization reaction is completed, add 1.245g of ammonium persulfate, and react again at 75~90°C for 2 hours to make the copolymerization reaction more complete. After the copolymerization reaction is completed, the reaction tank is cooled to 40°C, and _{neutralized to pH 7~9 with 25% NH 4} OH aqueous solution to obtain an aqueous dispersion containing core-shell structured emulsified polymer particles, and if the resulting aqueous dispersion is used The total weight of the dispersion is based on 100 parts by weight, and the resulting aqueous dispersion has 50 parts by weight of solid content and a viscosity of 13-20sec (ASTM Ford No. 4 viscosity cup). Further, the obtained emulsion polymer particles are particles with an average particle diameter of 1 μm and a core-shell structure, and the core Tg value of the particle structure is -40°C; and the Tg of the outer shell copolymer is 55°C.

analysis test

The finished products sampled from Example 1 to Example 5 are coated on paper, and dried with hot air at 60-65°C for 3 to 5 seconds. The dry film formed is about 10~14μm. Then, the coated paper was folded into a box for water. The experimental results are shown in Table 17.

Refer to the experimental results in Table 17 that the waterproof effect of Example 5 is the best. Therefore, the test time of Example 5 is further extended and it is found that the waterproof effect can be as long as two months. According to the above experimental results, adjusting the formula can know that the Tg value of the core copolymer is designed to be -40°C, and the Tg of the shell copolymer is designed to be 55°C, which can simultaneously have better water resistance and plasticity. According to the above results, it can be known that the ratio between acrylic esters and acrylamides affects the flexibility, hardness and viscosity of the coating. Among them, diacetone acrylamide (DAA) and dihydrazine adipic acid (ADH) help its paper improve the waterproof properties and increase the flexibility of the film, but adding too much will cause the film to feel sticky.

Step S2: Coating the waterproof paint on the base layer 10 by using the roller-type screen film 40. The waterproof coating of the present invention only uses water as a solvent, and other ingredients in the formula do not contain substances harmful to the human body and the environment, and it is a water-based environmentally friendly coating. Refer to Figure 4 for a schematic diagram of the roller-type screen coating 40 of the present invention. The roller-type screen coating 40 of the present invention is a cylinder, which can supply waterproof coating from the inside of the roller, and has a scraper 41 to effectively adjust the coating. 20 thickness and recover the excess waterproof coating. In an embodiment of the present invention, the thickness of the coating layer 20 may be 0.01 cm to 0.03 cm, preferably 0.02 cm to 0.03 cm, more preferably 0.02 cm to 0.025 cm, when When the thickness of the coating layer 20 is greater than 0.03 cm, subsequent drying will be difficult, and when the thickness of the coating layer 20 is less than 0.01 cm, the adhesion and waterproof effect during forming will be poor. In addition, the thickness of the required coating 20 determines the mesh value of the designed mesh 42 of the screen 40, and the thicker the required coating, the lower the selected mesh value. For example, the thickness of the 150 mesh coating is 0.025 cm, and the thickness of the 200 mesh coating is 0.02 cm. Therefore, in an embodiment of the present invention, the mesh size may be 100 mesh to 300 mesh, preferably 150 mesh to 300 mesh, more preferably 150 mesh to 200 mesh.

In an embodiment, the base layer 10 may be selected from paper, wood, metal, or any material capable of forming a continuous coating film thereon. The paper material may include, but is not limited to, kraft paper, coated paper, and white paper.

In the specific example of the present invention, for the convenience of description, the results of different meshes and thicknesses in the case of selecting the same paper material are shown in Table 15 below.

On the other hand, the viscosity of the waterproof coating suitable for the manufacturing method of the laminated structure of the present invention is 2000 cps to 3000 cps, preferably 2200 cps to 2800 cps, more preferably 2500 cps to 2600 cps. The viscosity of the waterproof coating is adjusted according to the drying speed and the thickness of the plate. When the viscosity is greater than 3000cps, it is more difficult to uniformly coat, causing the coated paper to fail to dry and cause back adhesion; when the thickness is less than 2000cps, it is difficult to heat Melting makes the effect of adhesion molding poor. The effect of viscosity on the coating is shown in Table 16 below.

Step S3: Alternately provide cold air and hot air until the coated base layer 10 is dried to form a laminated structure. The laminated structure includes the coating layer 20 and the base layer 10 formed of waterproof paint. The laminated structure of the present invention may be a circular screen coated structure, that is, a laminated structure formed by coating a circular screen. Among them, the hot air includes a first hot air and a second hot air with different temperatures. The hot air may further include a third hot air whose temperature is different from the first hot air and the second hot air. The temperature of the hot air can range from 70 degrees to 180 degrees. That is, the hot air may include hot air with a temperature ranging from 70 degrees to 180 degrees. For example, the hot air may further include a fourth hot air, a fifth hot air, and so on. In one embodiment, the temperature of the third hot air may be higher than the temperature of the second hot air, and the temperature of the second hot air may be higher than the temperature of the first hot air.

Referring to Fig. 5 for a schematic diagram of the drying process of the present invention, the coated base layer 10 is fed into an oven 50 as shown in Fig. 5. The oven 50 may further include an exhaust port 56, which can be proportional to the oven pressure. And speed adjustment of the ventilation speed. In an embodiment, the oven 50 may include one or more ovens. In an embodiment, the oven 50 may include a first oven 51, a second oven 52, a third oven 53, a fourth oven 54, and a fifth oven 55 that are continuously conveyed. The first oven 51, the second oven 52, the third oven 53, the fourth oven 54 and the fifth oven 55 respectively correspondingly generate the first hot air H1, the second hot air H2, the third hot air H3, the fourth hot air H4, and the Five hot air H5. The exhaust port 56 is located above the first oven 51, the second oven 52, the third oven 53, the fourth oven 54 and the fifth oven 55. Those skilled in the art can understand that as long as the first oven 51 can be installed The air in the second oven 52, the third oven 53, the fourth oven 54 and the fifth oven 55 is drawn out, and the position of the air outlet 56 is not limited thereto.

Temperature control during the drying process is extremely important. If the temperature is too high, it will cause embrittlement of the paper fiber and the coating of the waterproof coating. .

In one embodiment, referring to Fig. 5, the cold air C1 and the first hot air H1 are alternately provided five times in the first oven 51; the cold air C2 and the second hot air H2 are alternately provided five times in the second oven 52; The third oven 53 provides cold air C3 and the third hot air H3 alternately five times; the fourth oven 54 provides cold air C4 and the fourth hot air H4 alternately five times, and the fifth oven 55 provides cold air C5 and the fifth alternately five times Hot air H5. And in this embodiment, for example, the junction of the two ovens of the first oven 51 and the second oven 52 has a temperature change sequence of cold air C1, first hot air H1, second hot air H2, and cold air C2, and has a stepwise temperature regulation. This phenomenon is to prevent the instantaneous temperature change from being too large and adversely affecting the drying process. Among them, the cold air C1~C5 can be room temperature, The room temperature can be 20 degrees to 50 degrees, that is, the cold air C1~C5 can be independently 20 degrees to 50 degrees. In an embodiment, the cold air C1 to C5 may be the same or different. The first hot air H1 to the fifth hot air H5 may be independently selected from 70 degrees to 180 degrees, preferably 80 degrees to 180 degrees, and more preferably 80 degrees to 120 degrees.

In another embodiment, the cold air may be 25 degrees, the first hot air H1 may be 80 degrees, the second hot air H2 may be 100 degrees, the third hot air H3 may be 120 degrees, the fourth hot air H4 may be 100 degrees, and the Five hot air H5 can be 80 degrees. In this embodiment, the cold air and hot air in each of the first oven 51, the second oven 52, the third oven 53, the fourth oven 54 and the fifth oven 55 can be alternated 10 times.

In another embodiment, the cold air and hot air in the first oven 51, the second oven 52, the third oven 53, the fourth oven 54 and the fifth oven 55 can be alternated 5 times, and the first hot air H1 can be 80 degrees. , The second hot air H2 can be 100 degrees, the third hot air H3 can be 120 degrees, the fourth hot air H4 can be 100 degrees, and the fifth hot air H5 can be 80 degrees. In this embodiment, the cold air C1 may be 20 degrees, the cold air C2 may be 25 degrees, the cold air C3 may be 30 degrees, the cold air C4 may be 25 degrees, and the cold air C5 may be 20 degrees.

Furthermore, the number of alternating cold and hot air in the first oven 51, the second oven 52, the third oven 53, the fourth oven 54 and the fifth oven 55 can be adjusted according to requirements and is not limited to the above embodiment. Wherein, the number of alternating times of cold air and hot air in the first oven 51, the second oven 52, the third oven 53, the fourth oven 54 and the fifth oven 55 can be independently selected from one to twenty times.

Continuing the above, the following will further illustrate with examples. When the selected cold air is all 20 degrees and the number of alternating times is all five times, the first oven 51, the second oven 52, and the third oven 53. The influence of the hot air setting of the fourth oven 54 and the fifth oven 55 on its drying effect is shown in Table 17 below.

As shown in the above table, the drying effect of Example 3 is the best, which means that the manufacturing method according to Example 3 can achieve the best coating effect while avoiding paper embrittlement and paper back-sticking. In Example 3 of the present invention, the first oven 51 alternately provides cold air at room temperature and hot air at 80 degrees to dry the surface of the substrate; the second oven 52 alternately provides cold air at room temperature and hot air at 100 degrees to make the substrate surface dry. The fiber inside the material is dried; the third oven 53 alternately provides cold air at room temperature and hot air at 120 degrees to ensure that the substrate is completely dry; and the fourth oven 54 alternately provides cold air at room temperature and hot air at 100 degrees; and the fifth oven 55 alternately provides cold air at room temperature and hot air at 80 degrees, so that the laminated structure is slowly cooled down and then rolled up on a roller, which is conducive to storage and transportation.

The coating speed of the roller screen 40 coating is related to the equipment length of the oven 50. The longer the equipment length of the oven 50, the faster the drying speed, and the length of the oven can be added according to the required production speed. In an embodiment of the present invention, the coated paper moves in the oven for 1 minute 4 meters, the total length of the oven 50, that is, the sum of the lengths D1 to D5 is 16 to 20 meters. If the total length of the oven 50 is less than 16 meters, the coated substrate may be incompletely dried and need to be dried again, thereby prolonging the drying time. If the total length of the oven 50 is greater than 20 meters, It may require more space to place the oven 50. Specifically, the lengths D1 to D5 of the first oven 51, the second oven 52, the third oven 53, the fourth oven 54, and the fifth oven 55 may each be 4 meters.

Furthermore, the laminated structure made by the present invention can be made into a container by various forming methods known to those with ordinary knowledge in the technical field, specifically, it can be made into a food container. Food containers may include, but are not limited to: cups, bowls, plates, plates, packaging bags, lunch boxes, etc.

The above descriptions are merely illustrative and not restrictive. Any equivalent modifications or alterations that do not depart from the spirit and scope of the present invention should be included in the scope of the patent application.

S1~S3: steps

Claims (4)

A method for manufacturing a laminated structure, comprising: providing a waterproof coating, the waterproof coating including a solvent and a plurality of coating particles dispersed in the solvent, and the plurality of coating particles have a core and a shell; by using A roller-type screen film coating the waterproof coating on a base layer; and alternately providing a cold air and a hot air until the coated base layer is dried to form a laminated structure, the laminated structure including the waterproof coating formed A coating and the base layer of the hot air; wherein, the hot air includes a first hot air, a second hot air and a third hot air of different temperatures, the temperature of the hot air is 70 degrees to 180 degrees, and the temperature of the third hot air is high The temperature of the second hot air, and the temperature of the second hot air is higher than the temperature of the first hot air; the temperature of the cold air is 20 degrees to 50 degrees; the number of alternating times of the cold air and the hot air is 1-20 times; the The weight ratio of the core to the shell of the plurality of coating particles is 6:4, and the composition monomer of the core includes 20-50 parts by weight of isodecyl (meth)acrylate and 10-40 parts by weight of (methyl) Methyl acrylate, 30 to 40 parts by weight of butyl acrylate, 9 to 25 parts by weight of isooctyl acrylate, and 9 to 25 parts by weight of diacetone acrylamide, and the monomer of the shell contains 25 to 45 parts by weight Methyl (meth)acrylate, 15-40 parts by weight of methyl acrylate, 5-10 parts by weight of methacrylic acid, and 10-20 parts by weight of dihydrazine adipate; and The mesh of the drum type screen is 100 mesh to 300 mesh, and the thickness of the coating is 0.01 cm to 0.03 cm. The method described in item 1 of the scope of the patent application, wherein the viscosity of the waterproof coating is 2000 cps to 3000 cps. A laminated structure made by the method described in any one of items 1 to 2 of the scope of the patent application. A container made of laminated structure as described in item 3 of the scope of patent application.

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