A new single-layer gluing process for high-strength and high-transparency medical coated cover material base paper secondary emulsified primer

Abstract

The application provides a high-strength and high-transparency medical adhesive cover material raw paper secondary emulsified primer single-layer adhesive new process. The medical adhesive cover material paper is composed of a raw paper and a primer layer and a surface adhesive layer coated on the surface of the raw paper. The primer and modified inorganic pigments are used as main materials, the inorganic pigments include calcium carbonate, kaolin, titanium white powder, white carbon black and the like, the inorganic pigment dispersion liquid is prepared by using a silane coupling agent for modification, and then is mixed with the primer to perform secondary emulsification on the primer, and is used for primer adhesive coating of the medical adhesive cover material paper. The process mainly includes inorganic pigment coupling agent modification, primer secondary emulsification, surface adhesive coating and drying. The application constructs a coating by single-layer adhesive coating, controls the pore size of the primer paper, and the prepared high-strength and high-transparency medical adhesive cover material paper has high tensile strength and tear strength, and at the same time meets the requirements of the medical adhesive cover material paper on air permeability.

Description

Technical Field

[0001] This invention relates to a novel process for single-layer coating of high-strength, high-permeability medical adhesive cover paper with a secondary emulsified base adhesive. In particular, it relates to a method for improving the air permeability and strength of the base adhesive paper by controlling the pore size of the base adhesive paper through single-layer coating with a secondary emulsified base adhesive, which belongs to the field of applied chemistry. Background Technology

[0002] The safety performance of sterile medical devices is receiving increasing attention, requiring packaging materials with long-lasting and excellent protective effects. Blister-formed sterilization packaging materials include heat-sealing substrates and sealing caps. Sterile medical coated cap paper requires excellent permeability, including air permeability and antibacterial properties, and must be suitable for various sterilization methods such as ethylene oxide, electron beam, or Co60 irradiation. Compared to traditional sterilization and repackaging methods, the final sterilization mode for medical devices (i.e., packaging before sterilization) strengthens the control of contamination risks during transportation, storage, and use, significantly improving safety. Therefore, high-strength, high-permeability sterile medical coated cap paper is an inevitable development trend and direction for high-end medical packaging materials. High strength ensures clean peeling upon opening the medical device packaging, preventing contamination; high air permeability prevents the packaging from bursting during ethylene oxide sterilization due to poor air permeability. Currently, improving the strength and performance of the base adhesive paper for medical coated caps mainly relies on surface coating. However, surface coating significantly reduces air permeability, leading to lower product quality and limiting its application to low-end fields. Traditional composite modification processes are often complex and time-consuming, hindering industrial production. Therefore, there is an urgent need for a new process to prepare high-strength, high-permeability medical coated cap base adhesive paper to meet the demands of medical packaging.

[0003] To address the problems existing in the prior art, this invention creatively proposes a simplified process of single-layer coating and a composite modification method, which effectively improves the strength, dialysis performance, and sealing performance of the adhesive backing paper, providing a higher quality material for medical packaging. Summary of the Invention

[0004] The technical objective of this invention is to overcome the shortcomings of the existing technology and provide a novel process for a high-strength, high-permeability medical coated cover material with a modified single-layer adhesive composite paper-backing paper, exhibiting high tensile strength, tear strength, and peel strength, while also possessing good air permeability. To achieve the above technical objective, the technical solution adopted by this invention is as follows:

[0005] A novel process for applying a single layer of adhesive to a base paper of high-strength, high-transparency medical adhesive-coated cover material via secondary emulsification (compound modification) includes the following steps:

[0006] Step 1, High-strength, high-transparency medical coated cover material base paper composition: Composed of base paper and a composite modified base adhesive layer coated on the surface. Step 2, Inorganic pigment dispersion preparation: Inorganic pigments are modified using a coupling agent, first mixed and dispersed at low speed, then homogenized at high speed to prepare an inorganic pigment dispersion.

[0007] Step 3, secondary emulsification of the primer: The above dispersion and primer are mixed and emulsified in different proportions to obtain a secondary emulsified primer.

[0008] Step 4: Apply a secondary emulsified base coat (dilution ratio 1:2-1:6) to the surface of the base paper to obtain the base coat paper. Then apply the top coat according to the fixed process to obtain the medical coated cover paper.

[0009] Step 5: High-strength, high-transparency medical adhesive-coated cover paper can be heat-sealed with rigid plastic sheet.

[0010] In the preferred step 1, the adhesive layer coated on the surface of the base paper is evenly distributed on the surface of the base paper.

[0011] In step 1, the preferred drying temperature for the adhesive coating is 65-105℃.

[0012] In step 2, the inorganic pigments preferably include one or a mixture of several of the following: calcium carbonate, kaolin, satin white, and silica.

[0013] In step 2, one or more inorganic pigments are selected and mixed evenly, and the coupling agent is 1%-15% of the inorganic pigments.

[0014] The preferred preparation conditions for the inorganic pigment dispersion in step 2 are as follows: first, disperse at low speed for 1-3 hours with a stirring speed of 500-1200 rpm; then, homogenize at high speed for 0.5-1 hour with a stirring speed of 8000-10000 rpm. The dispersion has a solid content of 15%-30%, is stable for 8 hours, and can be homogenized and dispersed a second time, meeting the compatibility requirements with the primer.

[0015] In the preferred step 3, the base adhesive is an ethylene-vinyl acetate copolymer.

[0016] In the preferred step 4, the base adhesive dilution ratio is (1:2-1:6), the adhesive application amount is (1.5-4.5)±0.2g / m2, and the top adhesive application amount is 6.0±0.5g / m2.

[0017] In step 5, the preferred rigid plastic sheet includes PET, PVC, PS, PETG, etc.

[0018] The beneficial effects of this invention are:

[0019] 1) This invention mainly involves secondary emulsification of the primer with inorganic pigments, coupling agents, etc., to obtain a secondary emulsified primer. After dilution, the primer is coated to prepare a primer paper, and then a top coat is applied to prepare a medical coated cover paper.

[0020] 2) This medical coated cover paper has high tensile strength, tear strength and suitable peel strength, while also having good air permeability, enabling clean peeling when opening medical device packaging, preventing contamination of medical devices, and solving the problem of bag swelling during ethylene oxide sterilization.

[0021] 3) The synergistic effect of multiple inorganic pigments allows for adjustment of coating color, hiding power, gloss, and breathability. Silane coupling agents, a class of organosilicon compounds, improve the adhesion and durability between inorganic pigments and the primer. They react with the substrate surface to form chemical bonds, thereby enhancing the adhesion between the pigments and the substrate. This, in turn, improves the high strength and high transparency of medical coated cover paper, ensuring that its various performance indicators meet the usage standards. Attached Figure Description

[0022] Figure 1 To improve the stability of the secondary emulsified (compound modified) primer;

[0023] Figure 2 For high-strength, high-breathability adhesive paper and medical coated cover paper absorbency;

[0024] Figure 3 For high-strength, high-breathability medical coated cover paper with excellent peel performance;

[0025] Figure 4 This is for the heat-sealing performance of high-strength, high-breathability adhesive paper and medical coated cover paper.

[0026] Instruments and testing methods

[0027] The testing method involved in this invention is as follows:

[0028] The air permeability, strength (longitudinal / transverse tensile strength, longitudinal / transverse tear strength) and peel strength of the base paper, the base adhesive paper, and the medical coated cover paper were analyzed respectively.

[0029] Air permeability was measured using an air permeability meter. Tensile strength (both longitudinal and transverse) was measured using a tensile strength tester. Tear strength (both longitudinal and transverse) was measured using a paper tear tester. Peel strength was measured using an electronic tensile testing machine. The surface morphology of the adhesive layer was observed using a scanning electron microscope. Detailed Implementation

[0030] A novel process for applying a single layer of emulsified base adhesive to the base paper of a high-strength, high-transparency medical adhesive-coated cover material includes the following steps:

[0031] Step 1, High-strength, high-transparency medical adhesive cover material base paper composition: Composed of base paper and a secondary emulsified base adhesive layer coated on the surface. Step 2, Inorganic pigment dispersion preparation: Inorganic pigments are modified with silane coupling agents, first mixed and dispersed at low speed, then homogenized at high speed to prepare an inorganic pigment dispersion.

[0032] Step 3, secondary emulsification of primer: The above dispersion and primer are mixed and emulsified in different proportions to obtain a secondary emulsified primer solution.

[0033] Step 4: Apply a secondary emulsified primer to the surface of the base paper to obtain the primer paper, and then apply the top adhesive according to the fixed process to obtain the medical coated cover paper.

[0034] Step 5: The high-strength, high-transparency medical adhesive cover material can be heat-sealed with the rigid plastic sheet.

[0035] In the preferred step 1, the adhesive layer coated on the surface of the base paper is evenly distributed on the surface of the base paper.

[0036] In step 1, the preferred drying temperature for the adhesive coating is 65-105℃.

[0037] In step 2, the inorganic pigments preferably include one or a mixture of several of the following: calcium carbonate, kaolin, satin white, and silica.

[0038] In step 2, one or more inorganic pigments are selected and mixed and dispersed evenly, and the silane coupling agent is 1%-15% of the inorganic pigments.

[0039] The preferred preparation conditions for the inorganic pigment dispersion in step 2 are as follows: first, disperse at low speed for 1-3 hours with a stirring speed of 500-1200 rpm; then, homogenize at high speed for 0.5-1 hour with a stirring speed of 8000-10000 rpm. The dispersion has a solid content of 15%-30% and is stable for 8 hours, meeting the requirements.

[0040] In the preferred step 3, the base adhesive is an ethylene-vinyl acetate copolymer.

[0041] In the preferred step 4, the base adhesive dilution ratio is (1:2-1:6), the adhesive application amount is (1.5-4.5)±0.2g / m2, and the top adhesive application amount is 6.0±0.5g / m2.

[0042] In step 5, the preferred rigid plastic sheet includes PET, PVC, PS, PETG, etc.

[0043] The present invention will be further described in detail below with reference to specific embodiments.

[0044] Example 1

[0045] 1) Inorganic pigments are mixed with micron-sized calcium carbonate and 5% silane coupling agent, dispersed at 900 rpm for 2 hours, and then homogenized at 9000 rpm for 0.5 hours to prepare an inorganic pigment dispersion with a solid content of 25%.

[0046] 2) The above 5% inorganic pigment dispersion is mixed with ethylene-vinyl acetate copolymer and emulsified twice to obtain a secondary emulsified ethylene-vinyl acetate copolymer primer.

[0047] 3) Dilute the above-mentioned ethylene-vinyl acetate copolymer primer at a ratio of 1:4, apply it using an air knife at a speed of 26m / min, with a surface coating amount of 3.5±0.2g / m2, and dry it at 65℃ to produce primer paper. Then apply 6±0.5g / m2 of topcoat to obtain medical coated cover paper.

[0048] The base adhesive paper obtained in this embodiment has an air permeability of 120 ml / min, longitudinal / transverse tensile strength of 105.93 N / 67.27 N, and longitudinal / transverse tear strength of 854.48 mN / 886.52 mN. The finally obtained medical coated cover paper has an air permeability of 80 ml / min, longitudinal / transverse tensile strength of 116.73 N / 76.90 N, longitudinal / transverse tear strength of 862.99 mN / 951.90 mN, and peel force of 2.5 N.

[0049] Example 2

[0050] 1) Inorganic pigments were mixed with micron-sized calcium carbonate and nano-sized kaolin (with a synergistic effect at a ratio of 3:1) and 10% silane coupling agent. The mixture was first dispersed at 900 rpm for 2 hours, and then homogenized at 9000 rpm for 0.5 hours to prepare an inorganic pigment dispersion with a solid content of 25%.

[0051] 2) The above 6% inorganic pigment dispersion is emulsified with ethylene-vinyl acetate copolymer to obtain a secondary emulsified ethylene-vinyl acetate copolymer primer.

[0052] 3) Dilute the above-mentioned ethylene-vinyl acetate copolymer primer at a ratio of 1:2, apply it using an air knife at a speed of 30m / min, with a surface coating amount of 4.5±0.2g / m2, and dry it at 75℃ to produce primer paper. Then apply 6±0.5g / m2 of topcoat to obtain medical coated cover paper.

[0053] The air permeability of the base paper obtained in this embodiment is 105 ml / min, the longitudinal / transverse tensile strength is 102.91 N / 62.71 N, and the longitudinal / transverse tear strength is 801.72 mN / 862.54 mN. The finally obtained medical coated cover paper has an air permeability of 65 ml / min, a longitudinal / transverse tensile strength of 112.53 N / 73.45 N, a longitudinal / transverse tear strength of 813.61 mN / 902.30 mN, and a peel force of 2.0 N.

[0054] Example 3

[0055] 1) Inorganic pigments are mixed with micron-sized calcium carbonate and satin white (with a synergistic effect at a ratio of 3:1) and 13% silane coupling agent. The mixture is first dispersed at 1000 rpm for 2 hours, and then homogenized at 8000 rpm for 1 hour to prepare an inorganic pigment dispersion with a solid content of 15%.

[0056] 2) The above 5% inorganic pigment dispersion is emulsified with ethylene-vinyl acetate copolymer to obtain a secondary emulsified ethylene-vinyl acetate copolymer primer.

[0057] 3) The above-mentioned secondary emulsified ethylene-vinyl acetate copolymer primer is coated with an air knife at a speed of 35m / min, with a surface coating amount of 2.5±0.2g / m2 and a drying temperature of 85℃ to produce primer paper. Then, a top coat of 6±0.5g / m2 is applied to obtain medical coated cover paper.

[0058] The base adhesive paper obtained in this embodiment has an air permeability of 130 ml / min, longitudinal / transverse tensile strength of 129.2 N / 71.63 N, and longitudinal / transverse tear strength of 882.91 mN / 972.82 mN. The finally obtained medical coated cover paper has an air permeability of 85 ml / min, longitudinal / transverse tensile strength of 125.60 N / 87.80 N, longitudinal / transverse tear strength of 893.25 mN / 1019.89 mN, and peel force of 4.2 N.

[0059] Example 4

[0060] 1) Inorganic pigments were mixed with micron-sized calcium carbonate and silica (in a synergistic ratio of 5:1) and 8% silane coupling agent. The mixture was first dispersed at 1000 rpm for 2 hours, then homogenized at 8000 rpm for 1 hour to obtain a uniformly dispersed inorganic pigment dispersion with a solid content of 20%. 2) The above 5% inorganic pigment dispersion was then emulsified with ethylene-vinyl acetate copolymer to obtain a secondary emulsified ethylene-vinyl acetate copolymer primer.

[0061] 3) The above-mentioned secondary emulsified ethylene-vinyl acetate copolymer primer is diluted at a ratio of 1:6, coated with an air knife at a speed of 45m / min, with a surface coating amount of 1.5±0.2g / m2, and dried at 85℃ to produce primer paper. Then, a top coat of 6±0.5g / m2 is applied to obtain medical coated cover paper.

[0062] The base paper obtained in this embodiment has an air permeability of 140 ml / min, longitudinal / transverse tensile strength of 117.80 N / 63.57 N, and longitudinal / transverse tear strength of 784.53 mN / 805.42 mN. The finally obtained medical coated cover paper has an air permeability of 93 ml / min, longitudinal / transverse tensile strength of 105.73 N / 67.80 N, longitudinal / transverse tear strength of 826.65 mN / 989.41 mN, and peel force of 6.5 N.

[0063] Example 5

[0064] 1) Inorganic pigments were prepared by high-speed dispersion at 1200 rpm for 3 hours and homogenization at 10000 rpm for 1 hour, with a solid content of 18%. The inorganic pigments were prepared by nano-sized calcium carbonate, satin white and fumed silica (with synergistic effect in a ratio of 3:1:1) and 15% silane coupling agent.

[0065] 2) The above 5% inorganic pigment dispersion ethylene-vinyl acetate copolymer is emulsified a second time to obtain a secondary emulsified ethylene-vinyl acetate copolymer primer.

[0066] 3) The above-mentioned secondary emulsified ethylene-vinyl acetate copolymer primer is diluted at a ratio of 1:4, coated with an air knife at a speed of 45m / min, with a surface coating amount of 2.5±0.2g / m2, and dried at a temperature of 95℃ to produce primer paper. Then, a top coat of 6±0.5g / m2 is applied to obtain medical coated cover paper.

[0067] The base paper obtained in this embodiment has an air permeability of 145 ml / min, longitudinal / transverse tensile strength of 127.60 N / 74.41 N, and longitudinal / transverse tear strength of 869.22 mN / 976.81 mN. The finally obtained medical coated cover paper has an air permeability of 87 ml / min, longitudinal / transverse tensile strength of 121.90 N / 67.74 N, longitudinal / transverse tear strength of 902.75 mN / 981.97 mN, and peel force of 3.9 N.

[0068] Example 6

[0069] 1) Inorganic pigments were prepared by high-speed dispersion at 900 rpm for 2.5 h and homogenization at 9000 rpm for 0.5 h, with a solid content of 20%, using nano-sized kaolin and satin white (with a synergistic effect at a ratio of 3:1) and 12% silane coupling agent.

[0070] 2) The above 3% inorganic pigment dispersion ethylene-vinyl acetate copolymer is emulsified a second time to obtain a secondary emulsified ethylene-vinyl acetate copolymer primer.

[0071] 3) Dilute the above-mentioned secondary emulsified ethylene-vinyl acetate copolymer primer at a ratio of 1:4, apply it using an air knife at a speed of 40m / min, with a surface coating amount of 2.5±0.2g / m2, and dry it at 95℃ to produce primer paper. Then apply 6±0.5g / m2 of topcoat to obtain medical coated cover paper.

[0072] The air permeability of the base paper obtained in this embodiment is 140 ml / min, the longitudinal / transverse tensile strength is 118.80 N / 75.27 N, and the longitudinal / transverse tear strength is 815.91 mN / 941.44 mN. The finally obtained medical coated cover paper has an air permeability of 86 ml / min, a longitudinal / transverse tensile strength of 117.50 N / 65.70 N, a longitudinal / transverse tear strength of 899.59 mN / 910.06 mN, and a peel force of 3.8 N.

[0073] Example 7

[0074] 1) Inorganic pigments are synergistically mixed with nano-grade kaolin and silica (in a 3:1 ratio) and 8% silane coupling agent. They are first dispersed at 1000 rpm for 2 hours, then homogenized at 9000 rpm for 0.7 hours to prepare an inorganic pigment dispersion with a solid content of 20%.

[0075] 2) The above 5% inorganic pigment dispersion ethylene-vinyl acetate copolymer is emulsified a second time to obtain a secondary emulsified ethylene-vinyl acetate copolymer primer.

[0076] 3) Dilute the above-mentioned secondary emulsified ethylene-vinyl acetate copolymer primer at a ratio of 1:5.5, apply it using an air knife at a speed of 50m / min, with a surface coating amount of 2.0±0.2g / m2, and a drying temperature of 105℃ to produce primer paper. Then apply 6±0.5g / m2 of topcoat to obtain medical coated cover paper.

[0077] The base adhesive paper obtained in this embodiment has an air permeability of 155 ml / min, longitudinal / transverse tensile strength of 130.57 N / 75.27 N, and longitudinal / transverse tear strength of 873.45 mN / 1040.43 mN. The finally obtained medical coated cover paper has an air permeability of 95 ml / min, longitudinal / transverse tensile strength of 123.73 N / 70.60 N, longitudinal / transverse tear strength of 910.06 mN / 1014.66 mN, and peel force of 4.5 N.

[0078] Example 8

[0079] 1) Inorganic pigments are synergistically mixed with nano-grade kaolin, satin white, and white carbon black (in a ratio of 3:1:1) and 15% silane coupling agent. The mixture is first dispersed at 1200 rpm for 2 hours, then homogenized at 10000 rpm for 1 hour to prepare an inorganic pigment dispersion with a solid content of 18%.

[0080] 2) The above 5% inorganic pigment dispersion is emulsified with ethylene-vinyl acetate copolymer to obtain a secondary emulsified ethylene-vinyl acetate copolymer primer.

[0081] 3) The above-mentioned secondary emulsified ethylene-vinyl acetate copolymer primer is diluted at a ratio of 1:3, coated with an air knife at a speed of 32m / min, with a surface coating amount of 3.5±0.2g / m2, and dried at a temperature of 105℃ to produce primer paper. Then, a top coat of 6±0.5g / m2 is applied to obtain medical coated cover paper.

[0082] The base adhesive paper obtained in this embodiment has an air permeability of 160 ml / min, longitudinal / transverse tensile strength of 130.57 N / 75.27 N, and longitudinal / transverse tear strength of 865.31 mN / 971.84 mN. The finally obtained medical coated cover paper has an air permeability of 87 ml / min, longitudinal / transverse tensile strength of 127.2 N / 71.4 N, longitudinal / transverse tear strength of 893.45 mN / 962.50 mN, and peel force of 3.0 N.

Claims

1. A novel process for a single-layer coating of high-strength, high-transparency medical adhesive-coated cover paper with a secondary emulsified base adhesive, the specific method of which is as follows: (1) Preparation of inorganic pigment dispersion: Inorganic pigments were modified with silane coupling agents to prepare inorganic pigment dispersion; (2) Secondary emulsification of primer: Mix the inorganic pigment dispersion with the primer, emulsify the primer in two stages, and apply the primer after diluting it at a dilution ratio of 1:2-1:

6. (3) Surface coating: Apply the secondary emulsified primer from step 2 to the surface of the medical packaging cover paper; (4) Drying: After applying the base coat, dry the surface and then apply the top coat to obtain a high-strength and high-breathability medical coated cover paper. The base adhesive is an ethylene-vinyl acetate copolymer; The inorganic pigment is a mixture of two or more of calcium carbonate, satin white and silica, or a mixture of two or more of kaolin, satin white and silica.

2. The novel process for a single-layer coating of high-strength, high-transparency medical adhesive-coated cover material base paper with a secondary emulsified base adhesive, as described in claim 1, is characterized in that: The surface coating methods include roller coating and air knife coating.

3. The novel process for a single-layer coating of high-strength, high-transparency medical adhesive-coated cover material base paper with a secondary emulsified base adhesive, as described in claim 1, is characterized in that: The amount of primer applied is 1.5-4.5 g / m³. 2 .

4. The novel process for a single-layer coating of high-strength, high-transparency medical adhesive-coated cover paper with a secondary emulsified base adhesive, as described in claim 1, is characterized in that: The drying method is tunnel drying.

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